Orthostatic blood pressure regulation predicts classroom effort in children.

PubMed

Carapetian, Stephanie; Siedlarz, Monika; Jackson, Sandra; Perlmuter, Lawrence C

2008-04-01

The increase in orthostatic systolic blood pressure associated with the shift in posture from lying to standing requires several compensatory mechanisms to ensure adequate cerebral perfusion. Decreased efficiency in the various mechanisms controlling orthostatic blood pressure regulation can result in dizziness, lightheadedness, and syncope. The degree of effectiveness of orthostatic systolic blood pressure regulation (OBPR) serves as a marker for a variety of problems including fatigue, depression, anxiety, reduced attention, impulsive behavior and reduced volition. In normal children, an insufficient increase in systolic blood pressure in response to upright posture is predictive of mild cognitive and affective problems. The present study examined orthostatic systolic blood pressure regulation in relation to yearlong teachers' evaluations of academic grades and effort in 7-11 year old children. Poorer systolic blood pressure regulation in response to orthostasis was associated with reduced levels of classroom effort, while academic grades were spared. Converging evidence from clinical as well as experimental studies suggests that the linkage between (OBPR) and effort may be partially mediated by sympathetic dysfunction, altered release of neurotransmitters, or reduced cerebral blood flow.

Design for pressure regulating components

NASA Technical Reports Server (NTRS)

Wichmann, H.

1973-01-01

The design development for Pressure Regulating Components included a regulator component trade-off study with analog computer performance verification to arrive at a final optimized regulator configuration for the Space Storable Propulsion Module, under development for a Jupiter Orbiter mission. This application requires the pressure regulator to be capable of long-term fluorine exposure. In addition, individual but basically identical (for purposes of commonality) units are required for separate oxidizer and fuel pressurization. The need for dual units requires improvement in the regulation accuracy over present designs. An advanced regulator concept was prepared featuring redundant bellows, all metallic/ceramic construction, friction-free guidance of moving parts, gas damping, and the elimination of coil springs normally used for reference forces. The activities included testing of actual size seat/poppet components to determine actual discharge coefficients and flow forces. The resulting data was inserted into the computer model of the regulator. Computer simulation of the propulsion module performance over two mission profiles indicated satisfactory minimization of propellant residual requirements imposed by regulator performance uncertainties.

Self-regulation and social pressure reduce prejudiced responding and increase the motivation to be non-prejudiced.

PubMed

Buzinski, Steven G; Kitchens, Michael B

2017-01-01

Self-regulation constrains the expression of prejudice, but when self-regulation falters, the immediate environment can act as an external source of prejudice regulation. This hypothesis derives from work demonstrating that external controls and internal self-regulation can prompt goal pursuit in the absence of self-imposed controls. Across four studies, we found support for this complementary model of prejudice regulation. In Study 1, self-regulatory fatigue resulted in less motivation to be non-prejudiced, compared to a non-fatigued control. In Study 2, strong (vs. weak) perceived social pressure was related to greater motivation to be non-prejudiced. In Study 3, dispositional self-regulation predicted non-prejudice motivation when perceived social pressure was weak or moderate, but not when it was strong. Finally, in Study 4 self-regulatory fatigue increased prejudice when social pressure was weak but not when it was strong.

Application of a support vector machine algorithm to the safety precaution technique of medium-low pressure gas regulators

NASA Astrophysics Data System (ADS)

Hao, Xuejun; An, Xaioran; Wu, Bo; He, Shaoping

2018-02-01

In the gas pipeline system, safe operation of a gas regulator determines the stability of the fuel gas supply, and the medium-low pressure gas regulator of the safety precaution system is not perfect at the present stage in the Beijing Gas Group; therefore, safety precaution technique optimization has important social and economic significance. In this paper, according to the running status of the medium-low pressure gas regulator in the SCADA system, a new method for gas regulator safety precaution based on the support vector machine (SVM) is presented. This method takes the gas regulator outlet pressure data as input variables of the SVM model, the fault categories and degree as output variables, which will effectively enhance the precaution accuracy as well as save significant manpower and material resources.

49 CFR 179.201 - Individual specification requirements applicable to non-pressure tank car tanks.

Code of Federal Regulations, 2010 CFR

2010-10-01

... to non-pressure tank car tanks. 179.201 Section 179.201 Transportation Other Regulations Relating to... MATERIALS REGULATIONS SPECIFICATIONS FOR TANK CARS Specifications for Non-Pressure Tank Car Tanks (Classes... car tanks. ...

HIGH PRESSURE GAS REGULATOR

DOEpatents

Ramage, R.W.

1962-05-01

A gas regulator operating on the piston and feedback principle is described. The device is particularly suitable for the delicate regulation of high pressure, i.e., 10,000 psi and above, gas sources, as well as being perfectly adaptable for use on gas supplies as low as 50 psi. The piston is adjustably connected to a needle valve and the movement of the piston regulates the flow of gas from the needle valve. The gas output is obtained from the needle valve. Output pressure is sampled by a piston feedback means which, in turn, regulates the movement of the main piston. When the output is other than the desired value, the feedback system initiates movement of the main piston to allow the output pressure to be corrected or to remain constant. (AEC)

Pressure Regulator With Internal Ejector Circulation Pump, Flow and Pressure Measurement Porting, and Fuel Cell System Integration Options

NASA Technical Reports Server (NTRS)

Vasquez, Arturo

2011-01-01

An advanced reactant pressure regulator with an internal ejector reactant circulation pump has been developed to support NASA's future fuel cell power systems needs. These needs include reliable and safe operation in variable-gravity environments, and for exploration activities with both manned and un manned vehicles. This product was developed for use in Proton Exchange Membrane Fuel Cell (PEMFC) power plant reactant circulation systems, but the design could also be applied to other fuel cell system types, (e.g., solid-oxide or alkaline) or for other gas pressure regulation and circulation needs. The regulator design includes porting for measurement of flow and pressure at key points in the system, and also includes several fuel cell system integration options. NASA has recognized ejectors as a viable alternative to mechanical pumps for use in spacecraft fuel cell power systems. The ejector motive force is provided by a variable, high-pressure supply gas that travels through the ejector s jet nozzle, whereby the pressure energy of the fluid stream is converted to kinetic energy in the gas jet. The ejector can produce circulation-to-consumption-flow ratios that are relatively high (2-3 times), and this phenomenon can potentially (with proper consideration of the remainder of the fuel cell system s design) be used to provide completely for reactant pre-humidification and product water removal in a fuel cell system. Specifically, a custom pressure regulator has been developed that includes: (1) an ejector reactant circulation pump (with interchangeable jet nozzles and mixer sections, gas-tight sliding and static seals in required locations, and internal fluid porting for pressure-sensing at the regulator's control elements) and (2) internal fluid porting to allow for flow rate and system pressure measurements. The fluid porting also allows for inclusion of purge, relief, and vacuum-breaker check valves on the regulator assembly. In addition, this regulator could also be used with NASA's advanced nonflow-through fuel cell power systems by simply incorporating a jet nozzle with an appropriate nozzle diameter.

Ego depletion and attention regulation under pressure: is a temporary loss of self-control strength indeed related to impaired attention regulation?

PubMed

Englert, Chris; Zwemmer, Kris; Bertrams, Alex; Oudejans, Raôul R

2015-04-01

In the current study we investigated whether ego depletion negatively affects attention regulation under pressure in sports by assessing participants' dart throwing performance and accompanying gaze behavior. According to the strength model of self-control, the most important aspect of self-control is attention regulation. Because higher levels of state anxiety are associated with impaired attention regulation, we chose a mixed design with ego depletion (yes vs. no) as between-subjects and anxiety level (high vs. low) as within-subjects factor. Participants performed a perceptual-motor task requiring selective attention, namely, dart throwing. In line with our expectations, depleted participants in the high-anxiety condition performed worse and displayed a shorter final fixation on bull's eye, demonstrating that when one's self-control strength is depleted, attention regulation under pressure cannot be maintained. This is the first study that directly supports the general assumption that ego depletion is a major factor in influencing attention regulation under pressure.

Research on the influence of institutional pressures on green innovation strategy

NASA Astrophysics Data System (ADS)

Zewen, Chen; xin, Li; Hongjun, Cao

2017-11-01

Based on the new Institutional theory and the sample of 116 enterprises, this paper explores the influencing factors of green innovation strategy from the perspective of forced pressure, normative pressure and imitation pressure. The results show that the mandatory regulation, the incentive regulation, the supply chain pressure, and the competitive pressure all have a significant and positive impact on the green innovation strategy. Therefore, the government should take steps to stimulate enterprises to choose the green innovation strategy.

A role for AT1 receptor-associated proteins in blood pressure regulation.

PubMed

Castrop, Hayo

2015-04-01

The renin angiotensin-system is one of the most important humoral regulators of blood pressure. The recently discovered angiotensin receptor-associated proteins serve as local modulators of the renin angiotensin-system. These proteins interact with the AT1 receptor in a tissue-specific manner and regulate the sensitivity of the target cell for angiotensin II. The predominant effect of the AT1 receptor-associated proteins on angiotensin II-induced signaling is the modulation of the surface expression of the AT1 receptor. This review provides an overview of our current knowledge with respect to the relevance of AT1 receptor-associated proteins for blood pressure regulation. Two aspects of blood pressure regulation will be discussed in detail: angiotensin II-dependent volume homoeostasis and vascular resistance. Copyright © 2014 Elsevier Ltd. All rights reserved.

Flow compensating pressure regulator

NASA Technical Reports Server (NTRS)

Baehr, E. F. (Inventor)

1978-01-01

An apparatus for regulating pressure of treatment fluid during ophthalmic procedures is described. Flow sensing and pressure regulating diaphragms are used to modulate a flow control valve. The pressure regulating diaphragm is connected to the flow control valve to urge the valve to an open position due to pressure being applied to the diaphragm by bias means such as a spring. The flow sensing diaphragm is mechanically connected to the flow control valve and urges it to an opened position because of the differential pressure on the diaphragm generated by a flow of incoming treatment fluid through an orifice in the diaphragm. A bypass connection with a variable restriction is connected in parallel relationship to the orifice to provide for adjusting the sensitivity of the flow sensing diaphragm. A multiple lever linkage system is utilized between the center of the second diaphragm and the flow control valve to multiply the force applied to the valve by the other diaphragm and reverse the direction of the force.

Do agonistic motives matter more than anger? Three studies of cardiovascular risk in adolescents.

PubMed

Ewart, Craig K; Elder, Gavin J; Smyth, Joshua M; Sliwinski, Martin J; Jorgensen, Randall S

2011-09-01

Three motivational profiles have been associated with recurring psychological stress in low-income youth and young adults: Striving to control others (agonistic striving), striving to control the self (transcendence striving), and not asserting control (dissipated striving). Agonistic striving has been associated with elevated ambulatory blood pressure during daily activities. Three studies tested the hypotheses that: (1) agonistic striving is associated with poor anger regulation, and (2) agonistic striving and poor anger regulation interactively elevate blood pressure. Motivational profiles, anger regulation, and ambulatory blood pressure were assessed in a multiethnic sample of 264 urban youth. (1) anger regulation/recovery during laboratory challenge; (2) anger/blood pressure during daily activities (48 hours). Replication of the profiles in distant cities showed they occur with similar frequency across differences of region, race, and gender. Analyses controlling for body size, race, and gender revealed that individuals with the agonistic striving profile had higher ambulatory pressure, especially during social encounters. They became more openly angry and aggressive when challenged but did not exhibit difficulty regulating anger in the laboratory, nor did they feel angrier during monitoring. However, individuals with the agonistic striving profile who did display poor anger regulation in the lab had the highest blood pressure; deficient self-regulatory capability amplified the positive association between agonistic striving and cardiovascular risk in both genders and all ethnic groups. Although anger is thought to increase cardiovascular risk, present findings suggest that anger and elevated blood pressure are coeffects of agonistic struggles to control others.

BLOOD PRESSURE REGULATION III: WHAT HAPPENS WHEN ONE SYSTEM MUST SERVE TWO MASTERS: TEMPERATURE AND PRESSURE REGULATION?

PubMed Central

Kenney, W. Larry; Stanhewicz, Anna E.; Bruning, Rebecca S.; Alexander, Lacy M.

2013-01-01

When prolonged intense exercise is performed at high ambient temperatures, cardiac output must meet dual demands for increased blood flow to contracting muscle and to the skin. The literature has commonly painted this scenario as a fierce competition, wherein one circulation preserves perfusion at the expense of the other, with the regulated maintenance of blood pressure as the ultimate goal. This review redefines this scenario as commensalism, an integrated balance of regulatory control where one circulation benefits with little functional effect on the other. In young, healthy subjects, arterial pressure rarely falls to any great extent during either extreme passive heating or prolonged dynamic exercise in the heat. Nor does body temperature rise disproportionately due to a compromised skin blood flow. Rather, it often takes the superimposition of additional stressors – e.g., dehydration or simulated hemorrhage – upon heat stress to substantially impact blood pressure regulation. PMID:23636697

Blood pressure regulation III: what happens when one system must serve two masters: temperature and pressure regulation?

PubMed

Kenney, W Larry; Stanhewicz, Anna E; Bruning, Rebecca S; Alexander, Lacy M

2014-03-01

When prolonged intense exercise is performed at high ambient temperatures, cardiac output must meet dual demands for increased blood flow to contracting muscle and to the skin. The literature has commonly painted this scenario as a fierce competition, wherein one circulation preserves perfusion at the expense of the other, with the regulated maintenance of blood pressure as the ultimate goal. This review redefines this scenario as commensalism, an integrated balance of regulatory control where one circulation benefits with little functional effect on the other. In young, healthy subjects, arterial pressure rarely falls to any great extent during either extreme passive heating or prolonged dynamic exercise in the heat, nor does body temperature rise disproportionately due to a compromised skin blood flow. Rather, it often takes the superimposition of additional stressors--e.g., dehydration or simulated hemorrhage--upon heat stress to substantially impact blood pressure regulation.

49 CFR 179.100 - General specifications applicable to pressure tank car tanks.

Code of Federal Regulations, 2010 CFR

2010-10-01

... car tanks. 179.100 Section 179.100 Transportation Other Regulations Relating to Transportation... REGULATIONS SPECIFICATIONS FOR TANK CARS Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.100 General specifications applicable to pressure tank car tanks. ...

49 CFR 179.103-4 - Safety relief devices and pressure regulators.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 3 2013-10-01 2013-10-01 false Safety relief devices and pressure regulators. 179...) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120...

49 CFR 179.103-4 - Safety relief devices and pressure regulators.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 3 2014-10-01 2014-10-01 false Safety relief devices and pressure regulators. 179...) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120...

49 CFR 179.103-4 - Safety relief devices and pressure regulators.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 3 2011-10-01 2011-10-01 false Safety relief devices and pressure regulators. 179...) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120...

49 CFR 179.102 - Special commodity requirements for pressure tank car tanks.

Code of Federal Regulations, 2010 CFR

2010-10-01

... car tanks. 179.102 Section 179.102 Transportation Other Regulations Relating to Transportation... REGULATIONS SPECIFICATIONS FOR TANK CARS Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.102 Special commodity requirements for pressure tank car tanks. (a) In addition to...

Methods/Labor Standards Application Program - Phase IV

DTIC Science & Technology

1985-01-01

Engine Platform a. Pressure switch b. Compressor motor c. Voltage regulator d. Open and clean generator exciter and main windings S3 . Main Collector...clean motors b. Slip rings Gantry #3 Annual: S2. Engine Platform a. Pressure switch b. Compressor motor Voltage regulator d. Open and clean generator...Travel Motors Open and clean motorsa. b. Slip rings Gantry #4 S2 . S3. S4 . S5 . Engine Platform a. Pressure switch b. Compressor motor Voltage regulator

Design and develop speed/pressure regulator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hasanul Basher, A.M.

1993-09-01

The Physics Division at Oak Ridge National Laboratory has several recirculating water cooling systems. One of them supplies deionized water at 150 psi, which is mainly used for cooling magnet windings at the Oak Ridge Isochronous Cyclotron (ORIC). The system has three 125-hp water pumps, each of which is capable of supplying water at the rate of 1000 gpm. One of the major requirements of this water supply system is that the supply pressure must be kept constant. An adjustable-frequency speed controller was recently installed to control the speed of one of the pump motors. A servo-system was provided withmore » the adjustable-frequency controller for regulating motor speed and, subsequently, the water pressure. After unsuccessful attempts to operate the servo, it was concluded that the regulator may not work for the existing system. Prior to installation of the variable-frequency controller, pressure regulation was accomplished with a pneumatically controlled load by-pass valve. To maintain constant pressure in the system, it is necessary to run always at full load, even if full load is not on the system. Hence, there is a waste of energy when full load is not connected to the system. So, designing and implementing one regulator that works at any load condition has become necessary. This report discusses the design of such a pressure regulator.« less

77 FR 9520 - Airworthiness Directives; Bombardier Inc., Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-17

... a report of deformation at the neck of the pressure regulator body on certain oxygen cylinder and regulator assemblies (CRA). This AD requires an inspection to determine if a certain oxygen CRA is installed and the replacement of oxygen CRAs containing pressure regulators having a certain part number. We are...

Do Agonistic Motives Matter More Than Anger? Three Studies of Cardiovascular Risk in Adolescents

PubMed Central

Ewart, Craig K.; Elder, Gavin J.; Smyth, Joshua M.; Sliwinski, Martin J.; Jorgensen, Randall S.

2011-01-01

Objective Three motivational profiles have been associated with recurring psychological stress in low-income youth and young adults: Striving to control others (agonistic striving), striving to control the self (transcendence striving), and not asserting control (dissipated striving); Agonistic Striving has been associated with elevated ambulatory blood pressure during daily activities. Three studies tested the hypotheses that: (1) Agonistic Striving is associated with poor anger regulation, and (2) Agonistic Striving and poor anger regulation interactively elevate blood pressure. Design Motivational profiles, anger regulation, and ambulatory blood pressure were assessed in a multiethnic sample of 264 urban youth. Main outcome measures (1) Anger regulation/recovery during laboratory challenge; (2) anger / blood pressure during daily activities (48 hours). Results and conclusion Replication of the profiles in distant cities showed they occur with similar frequency across differences of region, race, and gender. Analyses controlling for body size, race, and gender revealed that individuals with the Agonistic Striving profile had higher ambulatory pressure, especially during social encounters. They became more openly angry and aggressive when challenged, but did not exhibit difficulty regulating anger in the laboratory, nor did they feel more angry during monitoring. However, individuals with the Agonistic Striving profile who did display poor anger regulation in the lab had the highest blood pressure; deficient self-regulatory capability amplified the positive association between Agonistic Striving and cardiovascular risk in both genders and all ethnic groups. Although anger is thought to increase cardiovascular risk, present findings suggest that anger and elevated blood pressure are co-effects of agonistic struggles to control others. PMID:21534673

An Evaluation of Ultra-High Pressure Regulator for Robotic Lunar Landing Spacecraft

NASA Technical Reports Server (NTRS)

Burnside, Christopher; Trinh, Huu; Pedersen, Kevin

2011-01-01

The Robotic Lunar Lander Development (RLLD) Project Office at NASA Marshall Space Flight Center (MSFC) has studied several lunar surface science mission concepts. These missions focus on spacecraft carrying multiple science instruments and power systems that will allow extended operations on the lunar surface. Initial trade studies of launch vehicle options for these mission concepts indicate that the spacecraft design will be significantly mass-constrained. To minimize mass and facilitate efficient packaging, the notional propulsion system for these landers has a baseline of an ultra-high pressure (10,000 psig) helium pressurization system that has been used on Defense missiles. The qualified regulator is capable of short duration use; however, the hardware has not been previously tested at NASA spacecraft requirements with longer duration. Hence, technical risks exist in using this missile-based propulsion component for spacecraft applications. A 10,000-psig helium pressure regulator test activity is being carried out as part of risk reduction testing for MSFC RLLD project. The goal of the test activity is to assess the feasibility of commercial off-the-shelf ultra-high pressure regulator by testing with a representative flight mission profile. Slam-start, gas blowdown, water expulsion, lock-up, and leak tests are also performed on the regulator to assess performance under various operating conditions. The preliminary test results indicated that the regulator can regulate helium to a stable outlet pressure of 740 psig within the +/- 5% tolerance band and maintain a lock-up pressure less than +5% for all tests conducted. Numerous leak tests demonstrated leakage less than 10-3 standard cubic centimeters per second (SCCS) for internal seat leakage at lock-up and less than10-5 SCCS for external leakage through the regulator ambient reference cavity. The successful tests have shown the potential for 10,000 psig helium systems in NASA spacecraft and have reduced risk associated with hardware availability and hardware ability to meet RLL mission requirements.

49 CFR 179.101 - Individual specification requirements applicable to pressure tank car tanks.

Code of Federal Regulations, 2010 CFR

2010-10-01

... to pressure tank car tanks. 179.101 Section 179.101 Transportation Other Regulations Relating to... MATERIALS REGULATIONS SPECIFICATIONS FOR TANK CARS Specifications for Pressure Tank Car Tanks (Classes DOT... tank car tanks. Editorial Note: At 66 FR 45186, Aug. 28, 2001, an amendment published amending a table...

Cellular pressure and volume regulation and implications for cell mechanics

NASA Astrophysics Data System (ADS)

Jiang, Hongyuan; Sun, Sean

2013-03-01

In eukaryotic cells, small changes in cell volume can serve as important signals for cell proliferation, death and migration. Volume and shape regulation also directly impacts the mechanics of the cell and multi-cellular tissues. Recent experiments found that during mitosis, eukaryotic cells establish a preferred steady volume and pressure, and the steady volume and pressure can robustly adapt to large osmotic shocks. Here we develop a mathematical model of cellular pressure and volume regulation, incorporating essential elements such as water permeation, mechano-sensitive channels, active ion pumps and active stresses in the actomyosin cortex. The model can fully explain the available experimental data, and predicts the cellular volume and pressure for several models of cell cortical mechanics. Furthermore, we show that when cells are subjected to an externally applied load, such as in an AFM indentation experiment, active regulation of volume and pressure leads to complex cellular response. We found the cell stiffness highly depends on the loading rate, which indicates the transport of water and ions might contribute to the observed viscoelasticity of cells.

Blood Pressure Regulation XI: Overview and Future Research Directions

PubMed Central

Raven, Peter B.; Chapleau, Mark W.

2014-01-01

While the importance of regulating arterial blood pressure within a ‘normal’ range is widely appreciated, the definition of ‘normal’ and the means by which humans and other species regulate blood pressure under various conditions remain hotly debated. The effects of diverse physiological, pathological and environmental challenges on blood pressure and the mechanisms that attempt to maintain it at an optimal level are reviewed and critically analyzed in a series of articles published in this themed issue of the European Journal of Applied Physiology. We summarize here the major points made in these reviews, with emphasis on unifying concepts of regulatory mechanisms and future directions for research. PMID:24463603

System Would Regulate Low Gas Pressure

NASA Technical Reports Server (NTRS)

Frazer, Robert E.

1994-01-01

System intended to maintain gases in containers at pressures near atmospheric. Includes ballast volume in form of underinflated balloon that communicates with working volume. Balloon housed in rigid chamber not subjected to extremes of temperature of working volume. Pressure in chamber surrounding balloon regulated at ambient atmospheric pressure or at constant small differential pressure above or below ambient. Expansion and contraction of balloon accommodates expansion or contraction of gas during operational heating or cooling in working volume, maintaining pressure in working volume at ambient or constant differential above or below ambient. Gas lost from system due to leakage or diffusion, low-pressure sensor responds, signaling valve actuators to supply more gas to working volume. If pressure rises too high, overpressure relief valve opens before excessive pressure damages system.

Pressurization, Pneumatic, and Vent Subsystems of the X-34 Main Propulsion System

NASA Technical Reports Server (NTRS)

Hedayat, A.; Steadman, T. E.; Brown, T. M.; Knight, K. C.; White, C. E., Jr.; Champion, R. H., Jr.

1998-01-01

In pressurization systems, regulators and orifices are use to control the flow of the pressurant. For the X-34 Main Propulsion System, three pressurization subsystem design configuration options were considered. In the first option, regulators were used while in the other options, orifices were considered. In each design option, the vent/relief system must be capable of relieving the pressurant flow without allowing the tank pressure to rise above proof, therefore, impacts on the propellant tank vent system were investigated and a trade study of the pressurization system was conducted. The analysis indicated that design option using regulators poses least risk. Then, a detailed transient thermal/fluid analysis of the recommended pressurization system was performed. Helium usage, thermodynamic conditions, and overpressurization of each propellant tank were evaluated. The pneumatic and purge subsystem is used for pneumatic valve actuation, Inter-Propellant Seal purges, Engine Spin Start, and engine purges at the required interface pressures, A transient analysis of the pneumatic and purge subsystem provided helium usage and flow rates to Inter-Propellant Seal and engine interfaces. Fill analysis of the helium bottles of pressurization and pneumatic subsystems during ground operation was performed. The required fill time and the stored

The granin VGF promotes genesis of secretory vesicles, and regulates circulating catecholamine levels and blood pressure

PubMed Central

Fargali, Samira; Garcia, Angelo L.; Sadahiro, Masato; Jiang, Cheng; Janssen, William G.; Lin, Wei-Jye; Cogliani, Valeria; Elste, Alice; Mortillo, Steven; Cero, Cheryl; Veitenheimer, Britta; Graiani, Gallia; Pasinetti, Giulio M.; Mahata, Sushil K.; Osborn, John W.; Huntley, George W.; Phillips, Greg R.; Benson, Deanna L.; Bartolomucci, Alessandro; Salton, Stephen R.

2014-01-01

Secretion of proteins and neurotransmitters from large dense core vesicles (LDCVs) is a highly regulated process. Adrenal LDCV formation involves the granin proteins chromogranin A (CgA) and chromogranin B (CgB); CgA- and CgB-derived peptides regulate catecholamine levels and blood pressure. We investigated function of the granin VGF (nonacronymic) in LDCV formation and the regulation of catecholamine levels and blood pressure. Expression of exogenous VGF in nonendocrine NIH 3T3 fibroblasts resulted in the formation of LDCV-like structures and depolarization-induced VGF secretion. Analysis of germline VGF-knockout mouse adrenal medulla revealed decreased LDCV size in noradrenergic chromaffin cells, increased adrenal norepinephrine and epinephrine content and circulating plasma epinephrine, and decreased adrenal CgB. These neurochemical changes in VGF-knockout mice were associated with hypertension. Germline knock-in of human VGF1–615 into the mouse Vgf locus rescued the hypertensive knockout phenotype, while knock-in of a truncated human VGF1–524 that lacks several C-terminal peptides, including TLQP-21, resulted in a small but significant increase in systolic blood pressure compared to hVGF1–615 mice. Finally, acute and chronic administration of the VGF-derived peptide TLQP-21 to rodents decreased blood pressure. Our studies establish a role for VGF in adrenal LDCV formation and the regulation of catecholamine levels and blood pressure.—Fargali, S., Garcia, A. L., Sadahiro, M., Jiang, C., Janssen, W. G., Lin, W.-J., Cogliani, V., Elste, A., Mortillo, S., Cero, C., Veitenheimer, B., Graiani, G., Pasinetti, G. M., Mahata, S. K., Osborn, J. W., Huntley, G. W., Phillips, G. R., Benson, D. L., Bartolomucci, A., Salton, S. R. The granin VGF promotes genesis of secretory vesicles, and regulates circulating catecholamine levels and blood pressure. PMID:24497580

Effect of Negative Pressure on Proliferation, Virulence Factor Secretion, Biofilm Formation, and Virulence-Regulated Gene Expression of Pseudomonas aeruginosa In Vitro

PubMed Central

Wang, Guo-Qi; Li, Tong-Tong; Li, Zhi-Rui; Zhang, Li-Cheng

2016-01-01

Objective. To investigate the effect of negative pressure conditions induced by NPWT on P. aeruginosa. Methods. P. aeruginosa was cultured in a Luria–Bertani medium at negative pressure of −125 mmHg for 24 h in the experimental group and at atmospheric pressure in the control group. The diameters of the colonies of P. aeruginosa were measured after 24 h. ELISA kit, orcinol method, and elastin-Congo red assay were used to quantify the virulence factors. Biofilm formation was observed by staining with Alexa Fluor® 647 conjugate of concanavalin A (Con A). Virulence-regulated genes were determined by quantitative RT-PCR. Results. As compared with the control group, growth of P. aeruginosa was inhibited by negative pressure. The colony size under negative pressure was significantly smaller in the experimental group than that in the controls (p < 0.01). Besides, reductions in the total amount of virulence factors were observed in the negative pressure group, including exotoxin A, rhamnolipid, and elastase. RT-PCR results revealed a significant inhibition in the expression level of virulence-regulated genes. Conclusion. Negative pressure could significantly inhibit the growth of P. aeruginosa. It led to a decrease in the virulence factor secretion, biofilm formation, and a reduction in the expression level of virulence-regulated genes. PMID:28074188

Involvement of WNK1-mediated potassium channels in the sexual dimorphism of blood pressure.

PubMed

Yu, Guofeng; Cheng, Mengting; Wang, Wei; Zhao, Rong; Liu, Zhen

2017-04-01

Potassium homeostasis plays an essential role in the control of blood pressure. It is unknown, however, whether potassium balance is involved in the gender-associated blood pressure differences. We therefore investigated the possible mechanism of sexual dimorphism in blood pressure regulation by measuring the blood pressure, plasma potassium, renal actions of potassium channels and upstream regulator in male and female mice. Here we found that female mice exhibited lower blood pressure and higher plasma K + level as compared to male littermates. Western blot analyses of mouse kidney extract revealed a significant decrease in renal outer medullary potassium (ROMK) channel expression, while large-conductance Ca 2+ -activated K + (BK) channel and Na-K-2Cl cotransporter (NKCC2) as well as the upstream regulator with-no-lysine kinase 1 (WNK1) enhanced in female mice under normal condition. Surprisingly, both dietary K + loading and K + depletion eliminated the differences in plasma K + and blood pressure between females and males, and the differences of renal K + channels and WNK1 also attenuated in both groups of mice. These findings indicated the existence of a close correlation between K + homeostasis and sex-associated blood pressure. Moreover, the differential regulation of ROMK, BK-α and NKCC2 between female and male mice, at least, were partly mediated via WNK1 pathway, which may contribute to the sexual dimorphism of plasma K + and blood pressure control. Copyright © 2017 Elsevier Inc. All rights reserved.

76 FR 64857 - Airworthiness Directives; Bombardier, Inc. Model BD-100-1A10 (Challenger 300) Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-19

..., deformation was found at the neck of the pressure regulator body on the oxygen Cylinder and Regulator.... This may cause elongation of the pressure regulator neck, which could result in rupture of the oxygen cylinder and in the case of cabin depressurization, oxygen not being available when required. * * * * * The...

[An investigation for standardized diagnosis and treatment of idiopathic normal-pressure hydrocephalus].

PubMed

Jiang, H J; Zhang, J M; Fu, W M; Zheng, Z; Luo, W; Zheng, Y X; Zhu, J M

2016-06-07

To investigate some important issues for diagnosis and treatment of idiopathic normal-pressure hydrocephalus (iNPH), such as standardized pre-operative assessment, initial pressure value of diverter pump, and pressure regulation during follow-up. Twenty six iNPH patients (21 males) who treated in Department of Neurosurgery of 2nd Affiliated Hospital of Zhejiang University School of Medicine from 2011 to 2015 were analyzed retrospectively. The average age was 60.5 year. The analysis focused on the treatment process of iNPH, initial pressure value of diverter pump, choice of diverter pump, and pressure regulation during follow-up. As a result, 24 cases (92.3%) had a good prognosis based on their imaging and clinical manifestations. Based on the literature and their clinical experiences, this department established a diagnosis and treatment procedure of iNPH and a pressure regulation procedure for the follow-up of iNPH. Moreover, it is proposed that choosing an anti-gravity diverter pump and making an initial pressure value 20 mmH2O less than pre-surgical cerebrospinal pressure may be beneficial for the prognosis. This standardized diagnosis and treatment procedure for iNPH is practical and effective.

Blood borne hormones in a cross-talk between peripheral and brain mechanisms regulating blood pressure, the role of circumventricular organs.

PubMed

Ufnal, Marcin; Skrzypecki, Janusz

2014-04-01

Accumulating evidence suggests that blood borne hormones modulate brain mechanisms regulating blood pressure. This appears to be mediated by the circumventricular organs which are located in the walls of the brain ventricular system and lack the blood-brain barrier. Recent evidence shows that neurons of the circumventricular organs express receptors for the majority of cardiovascular hormones. Intracerebroventricular infusions of hormones and their antagonists is one approach to evaluate the influence of blood borne hormones on the neural mechanisms regulating arterial blood pressure. Interestingly, there is no clear correlation between peripheral and central effects of cardiovascular hormones. For example, angiotensin II increases blood pressure acting peripherally and centrally, whereas peripherally acting pressor catecholamines decrease blood pressure when infused intracerebroventricularly. The physiological role of such dual hemodynamic responses has not yet been clarified. In the paper we review studies on hemodynamic effects of catecholamines, neuropeptide Y, angiotensin II, aldosterone, natriuretic peptides, endothelins, histamine and bradykinin in the context of their role in a cross-talk between peripheral and brain mechanisms involved in the regulation of arterial blood pressure. Copyright © 2014 Elsevier Ltd. All rights reserved.

The granin VGF promotes genesis of secretory vesicles, and regulates circulating catecholamine levels and blood pressure.

PubMed

Fargali, Samira; Garcia, Angelo L; Sadahiro, Masato; Jiang, Cheng; Janssen, William G; Lin, Wei-Jye; Cogliani, Valeria; Elste, Alice; Mortillo, Steven; Cero, Cheryl; Veitenheimer, Britta; Graiani, Gallia; Pasinetti, Giulio M; Mahata, Sushil K; Osborn, John W; Huntley, George W; Phillips, Greg R; Benson, Deanna L; Bartolomucci, Alessandro; Salton, Stephen R

2014-05-01

Secretion of proteins and neurotransmitters from large dense core vesicles (LDCVs) is a highly regulated process. Adrenal LDCV formation involves the granin proteins chromogranin A (CgA) and chromogranin B (CgB); CgA- and CgB-derived peptides regulate catecholamine levels and blood pressure. We investigated function of the granin VGF (nonacronymic) in LDCV formation and the regulation of catecholamine levels and blood pressure. Expression of exogenous VGF in nonendocrine NIH 3T3 fibroblasts resulted in the formation of LDCV-like structures and depolarization-induced VGF secretion. Analysis of germline VGF-knockout mouse adrenal medulla revealed decreased LDCV size in noradrenergic chromaffin cells, increased adrenal norepinephrine and epinephrine content and circulating plasma epinephrine, and decreased adrenal CgB. These neurochemical changes in VGF-knockout mice were associated with hypertension. Germline knock-in of human VGF1-615 into the mouse Vgf locus rescued the hypertensive knockout phenotype, while knock-in of a truncated human VGF1-524 that lacks several C-terminal peptides, including TLQP-21, resulted in a small but significant increase in systolic blood pressure compared to hVGF1-615 mice. Finally, acute and chronic administration of the VGF-derived peptide TLQP-21 to rodents decreased blood pressure. Our studies establish a role for VGF in adrenal LDCV formation and the regulation of catecholamine levels and blood pressure.

Fuel system for rotary distributor fuel injection pump

DOE Office of Scientific and Technical Information (OSTI.GOV)

Klopfer, K.H.; Kelly, W.W.

1993-06-01

In a fuel injection pump having a drive shaft, a pump rotor driven by the drive shaft, reciprocating pumping means with periodic intake and pumping strokes to periodically receive an intake charge of fuel and deliver fuel at high pressure for fuel injection is described; a distributor head with a plurality of angularly spaced distributor outlets, the pump rotor providing a distributor rotor with a distributor port connected to the pumping means, the distributor rotor being rotatably mounted in the distributor head for sequential registration of the distributor port with the distributor outlets for distributing said high pressure delivery ofmore » fuel thereto; a fuel system for supplying fuel to the pumping means, having an end chamber at one end of the pump rotor and a fuel supply pump driven by the drive shaft and having an inlet and outlet, the supply pump outlet being connected to the end chamber for supplying fuel thereto, and a pressure regulator for regulating the fuel pressure in the end chamber; and a control valve connected between the pumping means and the end chamber and selectively opened during the intake strokes to supply fuel to the pumping means from the end chamber and during the pumping strokes to spill fuel from the pumping means into the end chamber to terminate said high pressure delivery of fuel; the improvement wherein the fuel system comprises a fuel return passage connected in series with the end chamber downstream thereof, wherein the pressure regulator is mounted in the return passage for regulating the upstream fuel pressure, including the upstream fuel pressure within the end chamber, and is connected for conducting excess fuel for return to the supply pump inlet, and wherein the supply pump is driven by the drive shaft to supply fuel at a rate exceeding the rate of said high pressure delivery of fuel for fuel injection and to provide excess fuel flow continuously through the end chamber and return passage to the pressure regulator.« less

Possible role of extracellular signal-regulated kinase pathway in regulation of Sox9 mRNA expression in chondrocytes under hydrostatic pressure.

PubMed

Mio, Kensuke; Kirkham, Jennifer; Bonass, William A

2007-12-01

The potential involvement of the extracellular signal-regulated kinase (ERK) pathway in chondrocyte mechanotransduction was tested in bovine chondrocyte-agarose constructs under hydrostatic loading. Results suggested that the ERK pathway may be inhibited by hydrostatic pressure-induced mechanotransduction and may also be a negative regulator of Sox9 mRNA expression, which is an important modulator of chondrocyte function.

74. LIQUID NITROGEN TANK, REGULATOR VALVES, AND PRESSURE GAUGES FOR ...

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

74. LIQUID NITROGEN TANK, REGULATOR VALVES, AND PRESSURE GAUGES FOR LIQUID NITROGEN PUMPING STATION - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

Design and Testing of Suit Regulator Test Rigs

NASA Technical Reports Server (NTRS)

Campbell, Colin

2010-01-01

The next generation space suit requires additional capabilities for controlling and adjusting internal pressure compared to that of historical designs. Next generation suit pressures will range from slight pressure, for astronaut prebreathe comfort, to hyperbaric pressure levels for emergency medical treatment of decompression sickness. In order to test these regulators through-out their development life cycle, novel automated test rigs are being developed. This paper addresses the design philosophy, performance requirements, physical implementation, and test results with various units under test.

Correlation between cerebral hemodynamic and perfusion pressure changes in non-human primates

NASA Astrophysics Data System (ADS)

Ruesch, A.; Smith, M. A.; Wollstein, G.; Sigal, I. A.; Nelson, S.; Kainerstorfer, J. M.

2017-02-01

The mechanism that maintains a stable blood flow in the brain despite changes in cerebral perfusion pressure (CPP), and therefore guaranties a constant supply of oxygen and nutrients to the neurons, is known as cerebral auto-regulation (CA). In a certain range of CPP, blood flow is mediated by a vasomotor adjustment in vascular resistance through dilation of blood vessels. CA is known to be impaired in diseases like traumatic brain injury, Parkinson's disease, stroke, hydrocephalus and others. If CA is impaired, blood flow and pressure changes are coupled and thee oxygen supply might be unstable. Lassen's blood flow auto-regulation curve describes this mechanism, where a plateau of stable blood flow in a specific range of CPP corresponds to intact auto-regulation. Knowing the limits of this plateau and maintaining CPP within these limits can improve patient outcome. Since CPP is influenced by both intracranial pressure and arterial blood pressure, long term changes in either can lead to auto-regulation impairment. Non-invasive methods for monitoring blood flow auto-regulation are therefore needed. We propose too use Near infrared spectroscopy (NIRS) too fill this need. NIRS is an optical technique, which measures microvascular changes in cerebral hemoglobin concentration. We performed experiments on non-human primates during exsanguination to demonstrate that thee limits of blood flow auto-regulation can be accessed with NIRS.

Self-Organization of Blood Pressure Regulation: Experimental Evidence

PubMed Central

Fortrat, Jacques-Olivier; Levrard, Thibaud; Courcinous, Sandrine; Victor, Jacques

2016-01-01

Blood pressure regulation is a prime example of homeostatic regulation. However, some characteristics of the cardiovascular system better match a non-linear self-organized system than a homeostatic one. To determine whether blood pressure regulation is self-organized, we repeated the seminal demonstration of self-organized control of movement, but applied it to the cardiovascular system. We looked for two distinctive features peculiar to self-organization: non-equilibrium phase transitions and hysteresis in their occurrence when the system is challenged. We challenged the cardiovascular system by means of slow, 20-min Tilt-Up and Tilt-Down tilt table tests in random order. We continuously determined the phase between oscillations at the breathing frequency of Total Peripheral Resistances and Heart Rate Variability by means of cross-spectral analysis. We looked for a significant phase drift during these procedures, which signed a non-equilibrium phase transition. We determined at which head-up tilt angle it occurred. We checked that this angle was significantly different between Tilt-Up and Tilt-Down to demonstrate hysteresis. We observed a significant non-equilibrium phase transition in nine healthy volunteers out of 11 with significant hysteresis (48.1 ± 7.5° and 21.8 ± 3.9° during Tilt-Up and Tilt-Down, respectively, p < 0.05). Our study shows experimental evidence of self-organized short-term blood pressure regulation. It provides new insights into blood pressure regulation and its related disorders. PMID:27065880

Multi-bottle, no compressor, mean pressure control system for a Stirling engine

DOEpatents

Corey, John A.

1990-01-01

The invention relates to an apparatus for mean pressure control of a Stirling engine without the need for a compressor. The invention includes a multi-tank system in which there is at least one high pressure level tank and one low pressure level tank wherein gas flows through a maximum pressure and supply line from the engine to the high pressure tank when a first valve is opened until the maximum pressure of the engine drops below that of the high pressure tank opening an inlet regulator to permit gas flow from the engine to the low pressure tank. When gas flows toward the engine it flows through the minimum pressure supply line 2 when a second valve is opened from the low pressure tank until the tank reaches the engine's minimum pressure level at which time the outlet regulator opens permitting gas to be supplied from the high pressure tank to the engine. Check valves between the two tanks prevent any backflow of gas from occurring.

Real Time Ferrograph Development.

DTIC Science & Technology

1979-11-01

differential temperature of 65 0 C. Since opteo- electronic devices (photodiodes, photoresistors, etc.) have a maximum operating temperature around 85 0 C, it is...flow during the precipitation cycle. This regulator must keep the flow rate constant at any given temperature regardless of the differential pressure...across the sensing head. The pressure regulator achieved this by using the differential pressure across a fixed re;7trictor to move a bellows diaphragm

40 CFR Table W - 7 of Subpart W of Part 98-Default Methane Emission Factors for Natural Gas Distribution

Code of Federal Regulations, 2014 CFR

2014-07-01

... Connector 1.69 Block Valve 0.557 Control Valve 9.34 Pressure Relief Valve 0.27 Orifice Meter 0.212 Regulator 0.772 Open-ended Line 26.131 Population Emission Factors—Below Grade Metering-Regulating station 1..., Inlet Pressure 100 to 300 psig 0.20 Below Grade M&R Station, Inlet Pressure Population...

40 CFR Table W - 7 of Subpart W of Part 98-Default Methane Emission Factors for Natural Gas Distribution

Code of Federal Regulations, 2013 CFR

2013-07-01

... Connector 1.69 Block Valve 0.557 Control Valve 9.34 Pressure Relief Valve 0.27 Orifice Meter 0.212 Regulator 0.772 Open-ended Line 26.131 Population Emission Factors—Below Grade Metering-Regulating station 1..., Inlet Pressure 100 to 300 psig 0.20 Below Grade M&R Station, Inlet Pressure Population...

141. NITROGEN SUPPLY PANEL PRESSURE REGULATOR IN NORTHWEST CORNER OF ...

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

141. NITROGEN SUPPLY PANEL PRESSURE REGULATOR IN NORTHWEST CORNER OF CONTROL ROOM (214), LSB (BLDG. 751), FACING WEST - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

Local blockage of EMMPRIN impedes pressure ulcers healing in a rat model.

PubMed

Zhao, Xi-Lan; Luo, Xiao; Wang, Ze-Xin; Yang, Guo-Li; Liu, Ji-Zhong; Liu, Ya-Qiong; Li, Ming; Chen, Min; Xia, Yong-Mei; Liu, Jun-Jie; Qiu, Shu-Ping; Gong, Xiao-Qing

2015-01-01

Excessive extracellular matrix degradation caused by the hyperfunction of matrix metalloproteinases (MMPs) has been implicated in the failure of pressure ulcers healing. EMMPRIN, as a widely expressed protein, has emerged as an important regulator of MMP activity. We hypothesize that EMMPRIN affects the process of pressure ulcer healing by modulating MMP activity. In the rat pressure ulcer model, the expression of EMMPRIN in ulcers detected by Western blot was elevated compared with that observed in normal tissue. To investigate the role of EMMPRIN in regulating ulcer healing, specific antibodies against EMMPRIN were used via direct administration on the pressure ulcer. Local blockage of EMMPRIN resulted in a poor ulcer healing process compared with control ulcers, which was the opposite of our expectation. Furthermore, inhibiting EMMPRIN minimally impacted MMP activity. However, the collagen content in the pressure ulcer was reduced in the EMMPRIN treated group. Angiogenesis and the expression of angiogenic factors in pressure ulcers were also reduced by EMMPRIN local blockage. The results in the present study indicate a novel effect of EMMPRIN in the regulation of pressure ulcer healing by controlling the collagen contents and angiogenesis rather than MMPs activity.

Regulation of Blood Pressure by Targeting CaV1.2-Galectin-1 Protein Interaction.

PubMed

Hu, Zhenyu; Li, Guang; Wang, Jiong-Wei; Chong, Suet Yen; Yu, Dejie; Wang, Xiaoyuan; Soon, Jia Lin; Liang, Mui Cheng; Wong, Yuk Peng; Huang, Na; Colecraft, Henry M; Liao, Ping; Soong, Tuck Wah

2018-04-12

Background -L-type Ca V 1.2 channels play crucial roles in regulation of blood pressure. Galectin-1 (Gal-1), has been reported to bind to the I-II loop of Ca V 1.2 channels to reduce their current density. However, the mechanistic understanding for the down-regulation of Ca V 1.2 channels by Gal-1, and whether Gal-1 plays a direct role in blood pressure regulation remain unclear. Methods - In vitro experiments involving co-IP, western blot, patch-clamp recordings, immunohistochemistry and pressure myography were used to evaluate the molecular mechanisms by which Gal-1 down-regulates Ca V 1.2 channel in transfected HEK 293 cells, smooth muscle cells, arteries from Lgasl1 -/- mice, rat and human patients. In vivo experiments involving delivery of Tat-e9c peptide and AAV5-Gal-1 into rats were performed to investigate the effect of targeting Ca V 1.2-Gal-1 interaction on blood pressure monitored by tail cuff or telemetry methods. Results -Our study reveals that Gal-1 is a key regulator for proteasomal degradation of Ca V 1.2 channels. Gal-1 competed allosterically with Ca V β subunit for binding to the I-II loop of Ca V 1.2 channel. This competitive disruption of Ca V β binding led to Ca V 1.2 degradation by exposing the channels to poly-ubiquitination. Notably, we demonstrated that the inverse relationship of reduced Gal-1 and increased Ca V 1.2 protein levels in arteries was associated with hypertension in hypertensive rats and patients, and Gal-1 deficiency induces higher blood pressure in mice due to up-regulated Ca V 1.2 protein level in arteries. To directly regulate blood pressure by targeting the Ca V 1.2-Gal-1 interaction, we administered Tat-e9c, a peptide that competed for binding of Gal-1, by a mini-osmotic pump and this specific disruption of Ca V 1.2-Gal-1 coupling increased smooth muscle Ca V 1.2 currents, induced larger arterial contraction and caused hypertension in rats. In contrasting experiments, over-expression of Gal-1 in smooth muscle by a single bolus of AAV5-Gal-1 significantly reduced blood pressure in spontaneously hypertensive rats. Conclusions -We have defined molecularly that Gal-1 promotes Ca V 1.2 degradation by replacing Ca V β and thereby exposing specific lysines for poly-ubiquitination, and by masking I-II loop ER export signals. This mechanistic understanding provided the basis for targeting Ca V 1.2-Gal-1 interaction to demonstrate clearly the modulatory role Gal-1 plays in regulating blood pressure, and offering a potential approach for therapeutic management of hypertension.

Liquid Hydrogen Regulated Low Pressure High Flow Pneumatic Panel AFT Arrow Analysis

NASA Technical Reports Server (NTRS)

Jones, Kelley, M.

2013-01-01

Project Definition: Design a high flow pneumatic regulation panel to be used with helium and hydrogen. The panel will have two circuits, one for gaseous helium (GHe) supplied from the GHe Movable Storage Units (MSUs) and one for gaseous hydrogen (GH2) supplied from an existing GH2 Fill Panel. The helium will supply three legs; to existing panels and on the higher pressure leg and Simulated Flight Tanks (SFTs) for the lower pressure legs. The hydrogen line will pressurize a 33,000 gallon vacuum jacketed vessel.

Pressure Regulators as Valves for Saving Compressed Air and their Influence on System Dynamics

NASA Astrophysics Data System (ADS)

Dvořák, Lukáš; Fojtášek, Kamil

2015-05-01

Pressure regulators in the field of pneumatic mechanisms can be used as valves for saving compressed air. For example it can be used to reduce the pressure when the piston rod is retracting unloaded and thus it is possible to save some energy. However the problem is that saving valve can significantly affect the dynamics of the pneumatic system. The lower pressure in the piston rod chamber causes extension of time for retraction of the piston rod. This article compare the air consumption experimentally determined and calculated, measured curves of pressure in cylinder chambers and piston speed when saving valve is set up differently.

Wet atmospheric generation apparatus

NASA Technical Reports Server (NTRS)

Hamner, Richard M. (Inventor); Allen, Janice K. (Inventor)

1990-01-01

The invention described relates to an apparatus for providing a selectively humidified gas to a camera canister containing cameras and film used in space. A source of pressurized gas (leak test gas or motive gas) is selected by a valve, regulated to a desired pressure by a regulator, and routed through an ejector (venturi device). A regulated source of water vapor in the form of steam from a heated reservoir is coupled to a low pressure region of the ejector which mixes with high velocity gas flow through the ejector. This mixture is sampled by a dew point sensor to obtain dew point thereof (ratio of water vapor to gas) and the apparatus adjusted by varying gas pressure or water vapor to provide a mixture at a connector having selected humidity content.

40 CFR 52.2420 - Identification of plan.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Enforceable, Implementation Plan, Potential to Emit, State Enforceable, Volatile Organic Compound 4/1/96 3/12..., Regulation of the Board, These regulations. Terms Revised—Good Engineering Practice, Person, Volatile organic... pressure, Vapor pressure, Volatile organic compounds. Terms Removed: Air Quality Maintenance Area. 5-10-20...

SRC-1 regulates blood pressure and aortic stiffness in female mice

USDA-ARS?s Scientific Manuscript database

Framingham Heart Study suggests that dysfunction of steroid receptor coactivator-1 may be involved in the development of hypertension. However, there is no functional evidence linking steroid receptor coactivator-1 to the regulation of blood pressure. We used immunohistochemistry to map the expressi...

Renal intercalated cells and blood pressure regulation.

PubMed

Wall, Susan M

2017-12-01

Type B and non-A, non-B intercalated cells are found within the connecting tubule and the cortical collecting duct. Of these cell types, type B intercalated cells are known to mediate Cl - absorption and HCO 3 - secretion largely through pendrin-dependent Cl - /HCO 3 - exchange. This exchange is stimulated by angiotensin II administration and is also stimulated in models of metabolic alkalosis, for instance after aldosterone or NaHCO 3 administration. In some rodent models, pendrin-mediated HCO 3 - secretion modulates acid-base balance. However, the role of pendrin in blood pressure regulation is likely of more physiological or clinical significance. Pendrin regulates blood pressure not only by mediating aldosterone-sensitive Cl - absorption, but also by modulating the aldosterone response for epithelial Na + channel (ENaC)-mediated Na + absorption. Pendrin regulates ENaC through changes in open channel of probability, channel surface density, and channels subunit total protein abundance. Thus, aldosterone stimulates ENaC activity through both direct and indirect effects, the latter occurring through its stimulation of pendrin expression and function. Therefore, pendrin contributes to the aldosterone pressor response. Pendrin may also modulate blood pressure in part through its action in the adrenal medulla, where it modulates the release of catecholamines, or through an indirect effect on vascular contractile force. This review describes how aldosterone and angiotensin II-induced signaling regulate pendrin and the contributory role of pendrin in distal nephron function and blood pressure.

Engine control system having pressure-based timing

DOEpatents

Willi, Martin L [Dunlap, IL; Fiveland, Scott B [Metamora, IL; Montgomery, David T [Edelstein, IL; Gong, Weidong [Dunlap, IL

2011-10-04

A control system for an engine having a first cylinder and a second cylinder is disclosed having a first engine valve movable to regulate a fluid flow of the first cylinder and a first actuator associated with the first engine valve. The control system also has a second engine valve movable to regulate a fluid flow of the second cylinder and a sensor configured to generate a signal indicative of a pressure within the first cylinder. The control system also has a controller that is in communication with the first actuator and the sensor. The controller is configured to compare the pressure within the first cylinder with a desired pressure and selectively regulate the first actuator to adjust a timing of the first engine valve independently of the timing of the second engine valve based on the comparison.

Passive containment cooling system with drywell pressure regulation for boiling water reactor

DOEpatents

Hill, Paul R.

1994-01-01

A boiling water reactor having a regulating valve for placing the wetwell in flow communication with an intake duct of the passive containment cooling system. This subsystem can be adjusted to maintain the drywell pressure at (or slightly below or above) wetwell pressure after the initial reactor blowdown transient is over. This addition to the PCCS design has the benefit of eliminating or minimizing steam leakage from the drywell to the wetwell in the longer-term post-LOCA time period and also minimizes the temperature difference between drywell and wetwell. This in turn reduces the rate of long-term pressure buildup of the containment, thereby extending the time to reach the design pressure limit.

49 CFR 179.200 - General specifications applicable to non-pressure tank car tanks (Class DOT-111).

Code of Federal Regulations, 2010 CFR

2010-10-01

... tank car tanks (Class DOT-111). 179.200 Section 179.200 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS SPECIFICATIONS FOR TANK CARS Specifications for Non-Pressure Tank Car Tanks (Classes...

30 CFR 250.1007 - What to include in applications.

Code of Federal Regulations, 2013 CFR

2013-07-01

... and risers; pressure-regulating devices (including back-pressure regulators); sensing devices with.... (ii) If you propose to use one or more pipeline risers for a tension leg platform or other floating platform, your application must include: (A) The design fatigue life of the riser, with calculations, and...

30 CFR 250.1007 - What to include in applications.

Code of Federal Regulations, 2014 CFR

2014-07-01

... and risers; pressure-regulating devices (including back-pressure regulators); sensing devices with.... (ii) If you propose to use one or more pipeline risers for a tension leg platform or other floating platform, your application must include: (A) The design fatigue life of the riser, with calculations, and...

30 CFR 250.1007 - What to include in applications.

Code of Federal Regulations, 2012 CFR

2012-07-01

... and risers; pressure-regulating devices (including back-pressure regulators); sensing devices with.... (ii) If you propose to use one or more pipeline risers for a tension leg platform or other floating platform, your application must include: (A) The design fatigue life of the riser, with calculations, and...

Effects of Repeated Valsalva Maneuver Straining on Cardiac and Vasoconstrictive Baroreflex Responses

DTIC Science & Technology

2003-03-01

of blood pressure regulation that differ in men repeatedly exposed to high G acceleration. Am J Physiol Regul Integr Comp Physiol 2001; 280:R947–58. 10...Methods: We tested this hypothesis by measuring cardiac baroreflex responses to carotid baroreceptor stimulation (neck pressures ), and changes in heart rate...hypothesis is the observation that elevated pulse pressures in isolated carotid sinuses of dogs sen- sitized baroreceptor afferent firing (4,5). Elevated arte

An Evaluation of a High Pressure Regulator for NASA's Robotic Lunar Lander Spacecraft

NASA Technical Reports Server (NTRS)

Burnside, Christopher G.; Trinh, Huu P.; Pedersen, Kevin W.

2013-01-01

The Robotic Lunar Lander (RLL) development project office at NASA Marshall Space Flight Center is currently studying several lunar surface science mission concepts. The focus is on spacecraft carrying multiple science instruments and power systems that will allow extended operations on the lunar surface or other air-less bodies in the solar system. Initial trade studies of launch vehicle options indicate the spacecraft will be significantly mass and volume constrained. Because of the investment by the DOD in low mass, highly volume efficient components, NASA has investigated the potential integration of some of these technologies in space science applications. A 10,000 psig helium pressure regulator test activity has been conducted as part of the overall risk reduction testing for the RLL spacecraft. The regulator was subjected to typical NASA acceptance testing to assess the regulator response to the expected RLL mission requirements. The test results show the regulator can supply helium at a stable outlet pressure of 740 psig within a +/- 5% tolerance band and maintain a lock-up pressure less than the +5% above nominal outlet pressure for all tests conducted. Numerous leak tests demonstrated leakage less than 10-3 standard cubic centimeters per second (SCCS) for the internal seat leakage at lock-up and less than 10-5 SCCS for external leakage through the regulator body. The successful test has shown the potential for 10,000 psig helium systems in NASA spacecraft and has reduced risk associated with hardware availability and hardware ability to meet RLL mission requirements.

Compressed air demand-type firefighter's breathing system, volume 1. [design analysis and performance tests

NASA Technical Reports Server (NTRS)

Sullivan, J. L.

1975-01-01

The commercial availability of lightweight high pressure compressed air vessels has resulted in a lightweight firefighter's breathing apparatus. The improved apparatus, and details of its design and development are described. The apparatus includes a compact harness assembly, a backplate mounted pressure reducer assembly, a lightweight bubble-type facemask with a mask mounted demand breathing regulator. Incorporated in the breathing regulator is exhalation valve, a purge valve and a whistle-type low pressure warning that sounds only during inhalation. The pressure reducer assembly includes two pressure reducers, an automatic transfer valve and a signaling device for the low pressure warning. Twenty systems were fabricated, tested, refined through an alternating development and test sequence, and extensively examined in a field evaluation program. Photographs of the apparatus are included.

Involvement of Smad3 pathway in atrial fibrosis induced by elevated hydrostatic pressure.

PubMed

Wei, Wei; Rao, Fang; Liu, Fangzhou; Xue, Yumei; Deng, Chunyu; Wang, Zhaoyu; Zhu, Jiening; Yang, Hui; Li, Xin; Zhang, Mengzhen; Fu, Yongheng; Zhu, Wensi; Shan, Zhixin; Wu, Shulin

2018-06-01

Hypertension is a main risk factor for atrial fibrillation, but the direct effects of hydrostatic pressure on the atrial fibrosis are still unknown. The present study investigated whether hydrostatic pressure is responsible for atrial fibrosis, and addressed a potential role of the Smad pathway in this pathology. Biochemical assays were used to study regulation and expression of fibrotic factors in spontaneously hypertensive rats (SHRs) and Wistar rats, and in cardiac fibroblasts (CFs) cultured under standard (0 mmHg) and elevated (20, 40 mmHg) hydrostatic pressure. Levels of atrial fibrosis and protein expression of fibrotic factors Col-1A1/-3A1, TGF-β1, and MMP-2 in SHRs' left atrial tissues were higher than those in Wistar rats. Exposure to elevated pressure was associated with the proliferation of CFs. The protein expression of Col-1A1/-3A1, TGF-β1, and MMP-2 in CFs was also up-regulated in a pressure-dependent manner. The proliferation of CFs and increased expressions of fibrotic markers induced by elevated hydrostatic pressure could be reversed by the Smad3 inhibitor naringenin. The activation of Smad3 pathway was also stimulated by elevated hydrostatic pressure. These results demonstrate that CF secretory function and proliferation can be up-regulated by exposure to elevated pressure, and that Smad3 may modulate CF activation induced by high hydrostatic pressure. © 2017 Wiley Periodicals, Inc.

Hydrostatic pressure promotes the proliferation and osteogenic/chondrogenic differentiation of mesenchymal stem cells: The roles of RhoA and Rac1.

PubMed

Zhao, Yin-Hua; Lv, Xin; Liu, Yan-Li; Zhao, Ying; Li, Qiang; Chen, Yong-Jin; Zhang, Min

2015-05-01

Our previous studies have shown that hydrostatic pressure can serve as an active regulator for bone marrow mesenchymal stem cells (BMSCs). The current work further investigates the roles of cytoskeletal regulatory proteins Ras homolog gene family member A (RhoA) and Ras-related C3 botulinum toxin substrate 1 (Rac1) in hydrostatic pressure-related effects on BMSCs. Flow cytometry assays showed that the hydrostatic pressure promoted cell cycle initiation in a RhoA- and Rac1-dependent manner. Furthermore, fluorescence assays confirmed that RhoA played a positive and Rac1 displayed a negative role in the hydrostatic pressure-induced F-actin stress fiber assembly. Western blots suggested that RhoA and Rac1 play central roles in the pressure-inhibited ERK phosphorylation, and Rac1 but not RhoA was involved in the pressure-promoted JNK phosphorylation. Finally, real-time polymerase chain reaction (PCR) experiments showed that pressure promoted the expression of osteogenic marker genes in BMSCs at an early stage of osteogenic differentiation through the up-regulation of RhoA activity. Additionally, the PCR results showed that pressure enhanced the expression of chondrogenic marker genes in BMSCs during chondrogenic differentiation via the up-regulation of Rac1 activity. Collectively, our results suggested that RhoA and Rac1 are critical to the pressure-induced proliferation and differentiation, the stress fiber assembly, and MAPK activation in BMSCs. Copyright © 2015. Published by Elsevier B.V.

49 CFR 173.301b - Additional general requirements for shipment of UN pressure receptacles.

Code of Federal Regulations, 2012 CFR

2012-10-01

... pressure receptacles. 173.301b Section 173.301b Transportation Other Regulations Relating to Transportation....301b Additional general requirements for shipment of UN pressure receptacles. (a) General. The... gases in UN pressure receptacles. A UN pressure receptacle, including closures, must conform to the...

Directly measured cabin pressure conditions during Boeing 747-400 commercial aircraft flights.

PubMed

Kelly, Paul T; Seccombe, Leigh M; Rogers, Peter G; Peters, Matthew J

2007-07-01

In the low pressure environment of commercial aircraft, hypoxaemia may be common and accentuated in patients with lung or heart disease. Regulations specify a cabin pressure not lower than 750 hPa but it is not known whether this standard is met. This knowledge is important in determining the hazards of commercial flight for patients and the validity of current flight simulation tests. Using a wrist-watch recording altimeter, cabin pressure was recorded at 60 s intervals on 45 flights in Boeing 747-400 aircraft with three airlines. A log was kept of aircraft altitude using the in-flight display. Change in cabin pressure during flight, relationship between aircraft altitude and cabin pressure and proportion of flight time with cabin pressure approaching the minimum specified by regulation were determined. Flight duration averaged 10 h. Average cabin pressure during flight was 846 hPa. There was a linear fall in cabin pressure as the aircraft cruising altitude increased. At 10,300 m (34,000 ft) cabin pressure was 843 hPa and changed 8 hPa for every 300 m (1000 ft) change in aircraft altitude (r(2) = 0.993; P < 0.001). Lowest cabin pressure was 792 hPa at 12 200 m (40,000 ft) but during only 2% of flight time was cabin pressure less than 800 hPa. Cabin pressure is determined only by the engineering of the aircraft and its altitude and in the present study was always higher than required by regulation. Current fitness-to-fly evaluations simulate cabin conditions that passengers will not experience on these aircraft. There may be increased risks to patients should new or older aircraft operate nearer to the present minimum standard.

Unmanned Evaluation of Select Commercially Available Open Circuit Scuba Regulators for Cold Water Diving

DTIC Science & Technology

2010-04-01

Water Kit (dry system) installed as standard Abyss second stage with integrated 30-inch braided intermediate pressure hose as standard No user...diaphragm system) installed as standard Abyss second stage with integrated 30-inch braided intermediate pressure hose as standard No user adjustments...1st Stage Regulator with Abyss 2nd Stage and Integrated Intermediate Pressure Hose ..………………………….. A-2 A3 Modified Mares Proton Ice Extreme V32

Verification of the Chesapeake Bay Model.

DTIC Science & Technology

1981-12-01

points on the model. Each inflow control unit consists of a pressure regulator , a digital flow control valve, and a flowmeter (Fig- ure 8). A mechanical...spring-type pressure regulator ensures constant pressure to the digital flow control valve. Each digital valve contains eight solenoid valve actuators...FT) =0.798 EEOC 1DGS 2.78 EPOCH (DEGS) - 11. 84 3 DATA TAKEN: AC(0) = 0. 11 38 F T A (0)= 0. 1653 FT 28 MAR 1978 RANGE (FT) - 1.638 RANGE (FT

30 CFR 250.1007 - What to include in applications.

Code of Federal Regulations, 2011 CFR

2011-07-01

... line pipe and risers; pressure-regulating devices (including back-pressure regulators); sensing devices... § 250.198), if applicable. (ii) If you propose to use one or more pipeline risers for a tension leg... riser, with calculations, and the fatigue point at which you would replace the riser; (B) The results of...

HIF isoforms in the skin differentially regulate systemic arterial pressure

PubMed Central

Cowburn, Andrew S.; Takeda, Norihiko; Boutin, Adam T.; Kim, Jung-Whan; Sterling, Jane C.; Nakasaki, Manando; Southwood, Mark; Goldrath, Ananda W.; Jamora, Colin; Nizet, Victor; Chilvers, Edwin R.; Johnson, Randall S.

2013-01-01

Vascular flow through tissues is regulated via a number of homeostatic mechanisms. Localized control of tissue blood flow, or autoregulation, is a key factor in regulating tissue perfusion and oxygenation. We show here that the net balance between two hypoxia-inducible factor (HIF) transcription factor isoforms, HIF-1α and HIF-2α, is an essential mechanism regulating both local and systemic blood flow in the skin of mice. We also show that balance of HIF isoforms in keratinocyte-specific mutant mice affects thermal adaptation, exercise capacity, and systemic arterial pressure. The two primary HIF isoforms achieve these effects in opposing ways that are associated with HIF isoform regulation of nitric oxide production. We also show that a correlation exists between altered levels of HIF isoforms in the skin and the degree of idiopathic hypertension in human subjects. Thus, the balance between HIF-1α and HIF-2α expression in keratinocytes is a control element of both tissue perfusion and systemic arterial pressure, with potential implications in human hypertension. PMID:24101470

HOW GALACTIC ENVIRONMENT REGULATES STAR FORMATION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meidt, Sharon E.

2016-02-10

In a new simple model I reconcile two contradictory views on the factors that determine the rate at which molecular clouds form stars—internal structure versus external, environmental influences—providing a unified picture for the regulation of star formation in galaxies. In the presence of external pressure, the pressure gradient set up within a self-gravitating turbulent (isothermal) cloud leads to a non-uniform density distribution. Thus the local environment of a cloud influences its internal structure. In the simple equilibrium model, the fraction of gas at high density in the cloud interior is determined simply by the cloud surface density, which is itselfmore » inherited from the pressure in the immediate surroundings. This idea is tested using measurements of the properties of local clouds, which are found to show remarkable agreement with the simple equilibrium model. The model also naturally predicts the star formation relation observed on cloud scales and at the same time provides a mapping between this relation and the closer-to-linear molecular star formation relation measured on larger scales in galaxies. The key is that pressure regulates not only the molecular content of the ISM but also the cloud surface density. I provide a straightforward prescription for the pressure regulation of star formation that can be directly implemented in numerical models. Predictions for the dense gas fraction and star formation efficiency measured on large-scales within galaxies are also presented, establishing the basis for a new picture of star formation regulated by galactic environment.« less

Renal intercalated cells and blood pressure regulation

PubMed Central

Wall, Susan M.

2017-01-01

Type B and non-A, non-B intercalated cells are found within the connecting tubule and the cortical collecting duct. Of these cell types, type B intercalated cells are known to mediate Cl− absorption and HCO3− secretion largely through pendrin-dependent Cl−/HCO3− exchange. This exchange is stimulated by angiotensin II administration and is also stimulated in models of metabolic alkalosis, for instance after aldosterone or NaHCO3 administration. In some rodent models, pendrin-mediated HCO3− secretion modulates acid-base balance. However, the role of pendrin in blood pressure regulation is likely of more physiological or clinical significance. Pendrin regulates blood pressure not only by mediating aldosterone-sensitive Cl− absorption, but also by modulating the aldosterone response for epithelial Na+ channel (ENaC)-mediated Na+ absorption. Pendrin regulates ENaC through changes in open channel of probability, channel surface density, and channels subunit total protein abundance. Thus, aldosterone stimulates ENaC activity through both direct and indirect effects, the latter occurring through its stimulation of pendrin expression and function. Therefore, pendrin contributes to the aldosterone pressor response. Pendrin may also modulate blood pressure in part through its action in the adrenal medulla, where it modulates the release of catecholamines, or through an indirect effect on vascular contractile force. This review describes how aldosterone and angiotensin II-induced signaling regulate pendrin and the contributory role of pendrin in distal nephron function and blood pressure. PMID:29285423

Passive containment cooling system with drywell pressure regulation for boiling water reactor

DOEpatents

Hill, P.R.

1994-12-27

A boiling water reactor is described having a regulating valve for placing the wetwell in flow communication with an intake duct of the passive containment cooling system. This subsystem can be adjusted to maintain the drywell pressure at (or slightly below or above) wetwell pressure after the initial reactor blowdown transient is over. This addition to the PCCS design has the benefit of eliminating or minimizing steam leakage from the drywell to the wetwell in the longer-term post-LOCA time period and also minimizes the temperature difference between drywell and wetwell. This in turn reduces the rate of long-term pressure buildup of the containment, thereby extending the time to reach the design pressure limit. 4 figures.

The role of microtubules in the regulation of proteoglycan synthesis in chondrocytes under hydrostatic pressure.

PubMed

Jortikka, M O; Parkkinen, J J; Inkinen, R I; Kärner, J; Järveläinen, H T; Nelimarkka, L O; Tammi, M I; Lammi, M J

2000-02-15

Chondrocytes of the articular cartilage sense mechanical factors associated with joint loading, such as hydrostatic pressure, and maintain the homeostasis of the extracellular matrix by regulating the metabolism of proteoglycans (PGs) and collagens. Intermittent hydrostatic pressure stimulates, while continuous high hydrostatic pressure inhibits, the biosynthesis of PGs. High continuous hydrostatic pressure also changes the structure of cytoskeleton and Golgi complex in cultured chondrocytes. Using microtubule (MT)-affecting drugs nocodazole and taxol as tools we examined whether MTs are involved in the regulation of PG synthesis in pressurized primary chondrocyte monolayer cultures. Disruption of the microtubular array by nocodazole inhibited [(35)S]sulfate incorporation by 39-48%, while MT stabilization by taxol caused maximally a 17% inhibition. Continuous hydrostatic pressure further decreased the synthesis by 34-42% in nocodazole-treated cultures. This suggests that high pressure exerts its inhibitory effect through mechanisms independent of MTs. On the other hand, nocodazole and taxol both prevented the stimulation of PG synthesis by cyclic 0. 5 Hz, 5 MPa hydrostatic pressure. The drugs did not affect the structural and functional properties of the PGs, and none of the treatments significantly affected cell viability, as indicated by the high level of PG synthesis 24-48 h after the release of drugs and/or high hydrostatic pressure. Our data on two-dimensional chondrocyte cultures indicate that inhibition of PG synthesis by continuous high hydrostatic pressure does not interfere with the MT-dependent vesicle traffic, while the stimulation of synthesis by cyclic pressure does not occur if the dynamic nature of MTs is disturbed by nocodazole. Similar phenomena may operate in cartilage matrix embedded chondrocytes. Copyright 2000 Academic Press.

A Mechanism for Frequency Modulation in Songbirds Shared with Humans

PubMed Central

Margoliash, Daniel

2013-01-01

In most animals that vocalize, control of fundamental frequency is a key element for effective communication. In humans, subglottal pressure controls vocal intensity but also influences fundamental frequency during phonation. Given the underlying similarities in the biomechanical mechanisms of vocalization in humans and songbirds, songbirds offer an attractive opportunity to study frequency modulation by pressure. Here, we present a novel technique for dynamic control of subsyringeal pressure in zebra finches. By regulating the opening of a custom-built fast valve connected to the air sac system, we achieved partial or total silencing of specific syllables, and could modify syllabic acoustics through more complex manipulations of air sac pressure. We also observed that more nuanced pressure variations over a limited interval during production of a syllable concomitantly affected the frequency of that syllable segment. These results can be explained in terms of a mathematical model for phonation that incorporates a nonlinear description for the vocal source capable of generating the observed frequency modulations induced by pressure variations. We conclude that the observed interaction between pressure and frequency was a feature of the source, not a result of feedback control. Our results indicate that, beyond regulating phonation or its absence, regulation of pressure is important for control of fundamental frequencies of vocalizations. Thus, although there are separate brainstem pathways for syringeal and respiratory control of song production, both can affect airflow and frequency. We hypothesize that the control of pressure and frequency is combined holistically at higher levels of the vocalization pathways. PMID:23825417

[Experimental evaluation of the role of the coronary sinus pressure in the regulation of coronary return volume via the coronary sinus. Surgical considerations in atrio-pulmonary diversion procedures].

PubMed

Fantidis, P; Fernández Ruiz, M A; Madero Jarabo, R; Moreno Granados, F; Cordovilla Zurdo, G; Sanz Galeote, E

1990-11-01

In order to find out the validity of the vascular waterfall mechanism in coronary venous circulation, the role of coronary sinus pressure in the regulation of coronary return volume via the coronary sinus is studied in healthy animals. An experimental model of pressure regulation in the coronary sinus was prepared, and aortic pressure, EKG and the cardiac output (measured by thermodilution) were recorded. The return volume via the coronary sinus was measured at coronary sinus pressure of 10 or less, 15, 20, and 25 mmHg or more, for a total of 36 determinations. Increased coronary sinus pressure did not produce significant changes in aortic pressure, heart rate, cardiac index or coronary return volume via coronary sinus. When coronary sinus pressure was 25 mmHg or more, there was a significant decline in the average of coronary return volume via coronary sinus. Nevertheless, stepwise variant regression showed that the coronary sinus pressure per se does not condition the volume of coronary return via the coronary sinus. Our results suggest that in the healthy animals, the vascular waterfall mechanism in coronary venous circulation is not valid. Our results suggest that in the correction of congenital cardiac malformations using atriopulmonary anastomosis procedures, employing techniques that ensure coronary sinus drainage into the left atrium, in order to avoid the hemodynamic repercussions attributable to the vascular waterfall mechanism, is not justified.

A mechanism for frequency modulation in songbirds shared with humans.

PubMed

Amador, Ana; Margoliash, Daniel

2013-07-03

In most animals that vocalize, control of fundamental frequency is a key element for effective communication. In humans, subglottal pressure controls vocal intensity but also influences fundamental frequency during phonation. Given the underlying similarities in the biomechanical mechanisms of vocalization in humans and songbirds, songbirds offer an attractive opportunity to study frequency modulation by pressure. Here, we present a novel technique for dynamic control of subsyringeal pressure in zebra finches. By regulating the opening of a custom-built fast valve connected to the air sac system, we achieved partial or total silencing of specific syllables, and could modify syllabic acoustics through more complex manipulations of air sac pressure. We also observed that more nuanced pressure variations over a limited interval during production of a syllable concomitantly affected the frequency of that syllable segment. These results can be explained in terms of a mathematical model for phonation that incorporates a nonlinear description for the vocal source capable of generating the observed frequency modulations induced by pressure variations. We conclude that the observed interaction between pressure and frequency was a feature of the source, not a result of feedback control. Our results indicate that, beyond regulating phonation or its absence, regulation of pressure is important for control of fundamental frequencies of vocalizations. Thus, although there are separate brainstem pathways for syringeal and respiratory control of song production, both can affect airflow and frequency. We hypothesize that the control of pressure and frequency is combined holistically at higher levels of the vocalization pathways.

Enhanced Perfusion During Advanced Life Support Improves Survival With Favorable Neurologic Function in a Porcine Model of Refractory Cardiac Arrest

PubMed Central

Debaty, Guillaume; Metzger, Anja; Rees, Jennifer; McKnite, Scott; Puertas, Laura; Yannopoulos, Demetris; Lurie, Keith

2016-01-01

Objective To improve the likelihood for survival with favorable neurologic function after cardiac arrest, we assessed a new advanced life support approach using active compression-decompression cardiopulmonary resuscitation plus an intrathoracic pressure regulator. Design Prospective animal investigation. Setting Animal laboratory. Subjects Female farm pigs (n = 25) (39 ± 3 kg). Interventions Protocol A: After 12 minutes of untreated ventricular fibrillation, 18 pigs were randomized to group A—3 minutes of basic life support with standard cardiopulmonary resuscitation, defibrillation, and if needed 2 minutes of advanced life support with standard cardiopulmonary resuscitation; group B—3 minutes of basic life support with standard cardiopulmonary resuscitation, defibrillation, and if needed 2 minutes of advanced life support with active compression-decompression plus intrathoracic pressure regulator; and group C—3 minutes of basic life support with active compression-decompression cardiopulmonary resuscitation plus an impedance threshold device, defibrillation, and if needed 2 minutes of advanced life support with active compression-decompression plus intrathoracic pressure regulator. Advanced life support always included IV epinephrine (0.05 μg/kg). The primary endpoint was the 24-hour Cerebral Performance Category score. Protocol B: Myocardial and cerebral blood flow were measured in seven pigs before ventricular fibrillation and then following 6 minutes of untreated ventricular fibrillation during sequential 5 minutes treatments with active compression-decompression plus impedance threshold device, active compression-decompression plus intrathoracic pressure regulator, and active compression-decompression plus intrathoracic pressure regulator plus epinephrine. Measurements and Main Results Protocol A: One of six pigs survived for 24 hours in group A versus six of six in groups B and C (p = 0.002) and Cerebral Performance Category scores were 4.7 ± 0.8, 1.7 ± 0.8, and 1.0 ± 0, respectively (p = 0.001). Protocol B: Brain blood flow was significantly higher with active compression-decompression plus intrathoracic pressure regulator compared with active compression-decompression plus impedance threshold device (0.39 ± 0.23 vs 0.27 ± 0.14 mL/min/g; p = 0.03), whereas differences in myocardial perfusion were not statistically significant (0.65 ± 0.81 vs 0.42 ± 0.36 mL/min/g; p = 0.23). Brain and myocardial blood flow with active compression-decompression plus intrathoracic pressure regulator plus epinephrine were significantly increased versus active compression-decompression plus impedance threshold device (0.40 ± 0.22 and 0.84 ± 0.60 mL/min/g; p = 0.02 for both). Conclusion Advanced life support with active compression-decompression plus intrathoracic pressure regulator significantly improved cerebral perfusion and 24-hour survival with favorable neurologic function. These findings support further evaluation of this new advanced life support methodology in humans. PMID:25756411

Portable fixture facilitates pressure testing of instrumentation fittings

NASA Technical Reports Server (NTRS)

Olson, G. A.

1967-01-01

Portable fixture facilitates pressure testing to detect possible leaks in instrumentation fittings mounted on tank bulkheads. It uses a vacuum cup which seals a pressure regulator adapter around one side of the fitting to be pressure tested. Leakage is detected with a gas sniffer.

Regulation of pressure anisotropy in the solar wind: processes within inertial range of turbulence

NASA Astrophysics Data System (ADS)

Strumik, M.; Schekochihin, A. A.; Squire, J.; Bale, S. D.

2016-12-01

Dynamics of weakly collisional plasmas may lead to thermal pressure anisotropies that are driven by velocity shear, plasma expansion/compression or temperature gradients. The pressure anisotropies can provide free energy for the growth of micro-scale instabilities, like the mirror of firehose instabilities, that are commonly believed to constrain the pressure anisotropy in the solar wind if appropriate thresholds are exceeded. We discuss possible alternative mechanisms of regulation of the pressure anisotropy in the inertial range of solar wind turbulence that provide β-dependent constraints on the amplitude of fluctuations of pressure components and other quantities. In particular it is shown that double-adiabatic (CGL) closure for magnetohydrodynamic regime leads to 1/β scaling of the amplitude of the pressure component fluctuations and the pressure anisotropy. Both freely decaying and forced turbulence are discussed based on results of 3D numerical simulations and analytical theoretical predictions. The theoretical results are contrasted with WIND spacecraft measurements.

Self-Efficacy and Blood Pressure Self-Care Behaviors in Patients on Chronic Hemodialysis.

PubMed

Kauric-Klein, Zorica; Peters, Rosalind M; Yarandi, Hossein N

2017-07-01

This study examined the effects of an educative, self-regulation intervention on blood pressure self-efficacy, self-care outcomes, and blood pressure control in adults receiving hemodialysis. Simple randomization was done at the hemodialysis unit level. One hundred eighteen participants were randomized to usual care ( n = 59) or intervention group ( n = 59). The intervention group received blood pressure education sessions and 12 weeks of individual counseling on self-regulation of blood pressure, fluid, and salt intake. There was no significant increase in self-efficacy scores within ( F = .55, p = .46) or between groups at 12 weeks ( F = 2.76, p = .10). Although the intervention was not successful, results from the total sample ( N = 118) revealed that self-efficacy was significantly related to a number of self-care outcomes including decreased salt intake, lower interdialytic weight gain, increased adherence to blood pressure medications, and fewer missed hemodialysis appointments. Increased blood pressure self-efficacy was also associated with lower diastolic blood pressure.

Regulation of blood pressure and renal function by NCC and ENaC: lessons from genetically engineered mice.

PubMed

Verouti, Sophia N; Boscardin, Emilie; Hummler, Edith; Frateschi, Simona

2015-04-01

The activity of the thiazide-sensitive Na(+)/Cl(-) cotransporter (NCC) and of the amiloride-sensitive epithelial Na(+) channel (ENaC) is pivotal for blood pressure regulation. NCC is responsible for Na(+) reabsorption in the distal convoluted tubule (DCT) of the nephron, while ENaC reabsorbs the filtered Na(+) in the late DCT and in the cortical collecting ducts (CCD) providing the final renal adjustment to Na(+) balance. Here, we aim to highlight the recent advances made using transgenic mouse models towards the understanding of the regulation of NCC and ENaC function relevant to the control of sodium balance and blood pressure. We thus like to pave the way for common mechanisms regulating these two sodium-transporting proteins and their potential implication in structural remodeling of the nephron segments and Na(+) and Cl(-) reabsorption. Copyright © 2015 Elsevier Ltd. All rights reserved.

A common humoral background of intraocular and arterial blood pressure dysregulation.

PubMed

Skrzypecki, Janusz; Grabska-Liberek, Iwona; Przybek, Joanna; Ufnal, Marcin

2018-03-01

It has been postulated that intraocular pressure, an important glaucoma risk factor, correlates positively with arterial blood pressure (blood pressure). However, results of experimental and clinical studies are often contradictory. It is hypothesized that, in some hypertensive patients, disturbances in intraocular pressure regulation may depend on biological effects of blood borne hormones underlying a particular type of hypertension, rather than on blood pressure level itself. This review compares the effects of hormones on blood pressure and intraocular pressure, in order to identify a hormonal profile of hypertensive patients with an increased risk of intraocular pressure surge. The PUBMED database was searched to identify pre-clinical and clinical studies investigating the role of angiotensin II, vasopressin, adrenaline, noradrenaline, prostaglandins, and gaseous transmitters in the regulation of blood pressure and intraocular pressure. Studies included in the review suggest that intraocular and blood pressures often follow a different pattern of response to the same hormone. For example, vasopressin increases blood pressure, but decreases intraocular pressure. In contrast, high level of nitric oxide decreases blood pressure, but increases intraocular pressure. Arterial hypertension is associated with altered levels of blood borne hormones. Contradicting results of studies on the relationship between arterial hypertension and intraocular pressure might be partially explained by diverse effects of hormones on arterial and intraocular pressures. Further studies are needed to evaluate if hormonal profiling may help to identify glaucoma-prone patients.

40 CFR Table W - 7 of Subpart W-Default Methane Emission Factors for Natural Gas Distribution

Code of Federal Regulations, 2012 CFR

2012-07-01

... Valve 0.557 Control Valve 9.34 Pressure Relief Valve 0.27 Orifice Meter 0.212 Regulator 0.772 Open-ended Line 26.131 Population Emission Factors—Below Grade Metering-Regulating station 1 Components, Gas... 100 to 300 psig 0.20 Below Grade M&R Station, Inlet Pressure Population Emission...

Monocyte-derived extracellular Nampt-dependent biosynthesis of NAD+ protects the heart against pressure overload

PubMed Central

Yano, Masamichi; Akazawa, Hiroshi; Oka, Toru; Yabumoto, Chizuru; Kudo-Sakamoto, Yoko; Kamo, Takehiro; Shimizu, Yu; Yagi, Hiroki; Naito, Atsuhiko T.; Lee, Jong-Kook; Suzuki, Jun-ichi; Sakata, Yasushi; Komuro, Issei

2015-01-01

Nicotinamide phosphoribosyltransferase (Nampt) catalyzes the rate-limiting step in the salvage pathway for nicotinamide adenine dinucleotide (NAD+) biosynthesis, and thereby regulates the deacetylase activity of sirtuins. Here we show accommodative regulation of myocardial NAD+ by monocyte-derived extracellular Nampt (eNampt), which is essential for hemodynamic compensation to pressure overload. Although intracellular Nampt (iNampt) expression was decreased in pressure-overloaded hearts, myocardial NAD+ concentration and Sirt1 activity were preserved. In contrast, iNampt was up-regulated in spleen and monocytes, and circulating eNampt protein and nicotinamide mononucleotide (NMN), a key precursor of NAD+, were significantly increased. Pharmacological inhibition of Nampt by FK866 or depletion of monocytes/macrophages by clodronate liposomes disrupted the homeostatic mechanism of myocardial NAD+ levels and NAD+-dependent Sirt1 activity, leading to susceptibility to cardiomyocyte apoptosis and cardiac decompensation in pressure-overloaded mice. These biochemical and hemodynamic defects were prevented by systemic administration of NMN. Our studies uncover a crucial role of monocyte-derived eNampt in myocardial adaptation to pressure overload, and highlight a potential intervention controlling myocardial NAD+ against heart failure. PMID:26522369

Role of rpoS in the Development of Cell Envelope Resilience and Pressure Resistance in Stationary-Phase Escherichia coli▿

PubMed Central

Charoenwong, Duangkamol; Andrews, Simon; Mackey, Bernard

2011-01-01

This work investigated the role of rpoS in the development of increased cell envelope resilience and enhanced pressure resistance in stationary-phase cells of Escherichia coli. Loss of both colony-forming ability and membrane integrity, measured as uptake of propidium iodide (PI), occurred at lower pressures in E. coli BW3709 (rpoS) than in the parental strain (BW2952). The rpoS mutant also released much higher concentrations of protein under pressure than the parent. We propose that RpoS-regulated functions are responsible for the increase in membrane resilience as cells enter stationary phase and that this plays a major role in the development of pressure resistance. Strains from the Keio collection with mutations in two RpoS-regulated genes, cfa (cyclopropane fatty acyl phospholipid synthase) and osmB (outer membrane lipoprotein), were significantly more pressure sensitive and took up more PI than the parent strain, with cfa having the greatest effect. Mutations in the bolA morphogene and other RpoS-regulated lipoprotein genes (osmC, osmE, osmY, and ybaY) had no effect on pressure resistance. The cytoplasmic membranes of the rpoS mutant failed to reseal after pressure treatment, and strains with mutations in osmB and nlpI (new lipoprotein) were also somewhat impaired in the ability to reseal their membranes. The cfa mutant, though pressure sensitive, was unaffected in membrane resealing, implying that the initial transient permeabilization event is critical for loss of viability rather than the failure to reseal. The enhanced pressure sensitivity of polA, recA, and xthA mutants suggested that DNA may be a target of oxidative stress in pressure-treated cells. PMID:21705547

Role of rpoS in the development of cell envelope resilience and pressure resistance in stationary-phase Escherichia coli.

PubMed

Charoenwong, Duangkamol; Andrews, Simon; Mackey, Bernard

2011-08-01

This work investigated the role of rpoS in the development of increased cell envelope resilience and enhanced pressure resistance in stationary-phase cells of Escherichia coli. Loss of both colony-forming ability and membrane integrity, measured as uptake of propidium iodide (PI), occurred at lower pressures in E. coli BW3709 (rpoS) than in the parental strain (BW2952). The rpoS mutant also released much higher concentrations of protein under pressure than the parent. We propose that RpoS-regulated functions are responsible for the increase in membrane resilience as cells enter stationary phase and that this plays a major role in the development of pressure resistance. Strains from the Keio collection with mutations in two RpoS-regulated genes, cfa (cyclopropane fatty acyl phospholipid synthase) and osmB (outer membrane lipoprotein), were significantly more pressure sensitive and took up more PI than the parent strain, with cfa having the greatest effect. Mutations in the bolA morphogene and other RpoS-regulated lipoprotein genes (osmC, osmE, osmY, and ybaY) had no effect on pressure resistance. The cytoplasmic membranes of the rpoS mutant failed to reseal after pressure treatment, and strains with mutations in osmB and nlpI (new lipoprotein) were also somewhat impaired in the ability to reseal their membranes. The cfa mutant, though pressure sensitive, was unaffected in membrane resealing, implying that the initial transient permeabilization event is critical for loss of viability rather than the failure to reseal. The enhanced pressure sensitivity of polA, recA, and xthA mutants suggested that DNA may be a target of oxidative stress in pressure-treated cells.

46 CFR 105.10-20 - Pressure vacuum relief valve.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Pressure vacuum relief valve. (a) The term pressure vacuum relief valve means any device or assembly of a mechanical, liquid, weight, or other type used for the automatic regulation of pressure or vacuum in enclosed... 46 Shipping 4 2011-10-01 2011-10-01 false Pressure vacuum relief valve. 105.10-20 Section 105.10...

46 CFR 105.10-20 - Pressure vacuum relief valve.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Pressure vacuum relief valve. (a) The term pressure vacuum relief valve means any device or assembly of a mechanical, liquid, weight, or other type used for the automatic regulation of pressure or vacuum in enclosed... 46 Shipping 4 2010-10-01 2010-10-01 false Pressure vacuum relief valve. 105.10-20 Section 105.10...

46 CFR 105.10-20 - Pressure vacuum relief valve.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Pressure vacuum relief valve. (a) The term pressure vacuum relief valve means any device or assembly of a mechanical, liquid, weight, or other type used for the automatic regulation of pressure or vacuum in enclosed... 46 Shipping 4 2014-10-01 2014-10-01 false Pressure vacuum relief valve. 105.10-20 Section 105.10...

46 CFR 105.10-20 - Pressure vacuum relief valve.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Pressure vacuum relief valve. (a) The term pressure vacuum relief valve means any device or assembly of a mechanical, liquid, weight, or other type used for the automatic regulation of pressure or vacuum in enclosed... 46 Shipping 4 2012-10-01 2012-10-01 false Pressure vacuum relief valve. 105.10-20 Section 105.10...

46 CFR 105.10-20 - Pressure vacuum relief valve.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Pressure vacuum relief valve. (a) The term pressure vacuum relief valve means any device or assembly of a mechanical, liquid, weight, or other type used for the automatic regulation of pressure or vacuum in enclosed... 46 Shipping 4 2013-10-01 2013-10-01 false Pressure vacuum relief valve. 105.10-20 Section 105.10...

49 CFR 192.197 - Control of the pressure of gas delivered from high-pressure distribution systems.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 3 2010-10-01 2010-10-01 false Control of the pressure of gas delivered from high-pressure distribution systems. 192.197 Section 192.197 Transportation Other Regulations Relating to... STANDARDS Design of Pipeline Components § 192.197 Control of the pressure of gas delivered from high...

Spool-Valve Pressure-Difference Regulator

NASA Technical Reports Server (NTRS)

Grasso, A. P.

1983-01-01

Valves maintain preset pressure difference between gas flows. Two spool valves connected by shaft move back and forth in response to changes in pressure in oxygen and hydrogen chambers. Spool-valve assembly acts to restore pressures to preset difference. By eliminating diaphragms, pressure exerted directly on external end of spool valve; however, forces and therefore sensitivity of assembly are reduced.

Controlled differential pressure system for an enhanced fluid blending apparatus

DOEpatents

Hallman, Jr., Russell Louis

2009-02-24

A system and method for producing a controlled blend of two or more fluids. Thermally-induced permeation through a permeable tube is used to mix a first fluid from outside the tube with a second fluid flowing through the tube. Mixture ratios may be controlled by adjusting the temperature of the first fluid or by adjusting the pressure drop through the permeable tube. The combination of a back pressure control valve and a differential regulator is used to control the output pressure of the blended fluid. The combination of the back pressure control valve and differential regulator provides superior flow control of the second dry gas. A valve manifold system may be used to mix multiple fluids, and to adjust the volume of blended fluid produced, and to further modify the mixture ratio.

75 FR 10410 - Alternate Fracture Toughness Requirements for Protection Against Pressurized Thermal Shock Events...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-08

... Toughness Requirements for Protection Against Pressurized Thermal Shock Events; Correcting Amendment AGENCY... Commission (NRC) is revising its regulations to add a table that was inadvertently omitted in a correction... toughness requirements for protection against pressurized thermal shock (PTS) events for pressurized water...

49 CFR 179.101 - Individual specification requirements applicable to pressure tank car tanks.

Code of Federal Regulations, 2011 CFR

2011-10-01

... to pressure tank car tanks. 179.101 Section 179.101 Transportation Other Regulations Relating to... (CONTINUED) SPECIFICATIONS FOR TANK CARS Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.101 Individual specification requirements applicable to pressure tank car...

49 CFR 179.101 - Individual specification requirements applicable to pressure tank car tanks.

Code of Federal Regulations, 2013 CFR

2013-10-01

... to pressure tank car tanks. 179.101 Section 179.101 Transportation Other Regulations Relating to... (CONTINUED) SPECIFICATIONS FOR TANK CARS Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.101 Individual specification requirements applicable to pressure tank car...

49 CFR 179.101 - Individual specification requirements applicable to pressure tank car tanks.

Code of Federal Regulations, 2012 CFR

2012-10-01

... to pressure tank car tanks. 179.101 Section 179.101 Transportation Other Regulations Relating to... (CONTINUED) SPECIFICATIONS FOR TANK CARS Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.101 Individual specification requirements applicable to pressure tank car...

Numerical modeling of dynamics of heart rate and arterial pressure during passive orthostatic test

NASA Astrophysics Data System (ADS)

Ishbulatov, Yu. M.; Kiselev, A. R.; Karavaev, A. S.

2018-04-01

A model of human cardiovascular system is proposed to describe the main heart rhythm, influence of autonomous regulation on frequency and strength of heart contractions and resistance of arterial vessels; process of formation of arterial pressure during systolic and diastolic phases; influence of respiration; synchronization between loops of autonomous regulation. The proposed model is used to simulate the dynamics of heart rate and arterial pressure during passive transition from supine to upright position. Results of mathematical modeling are compared to original experimental data.

Internal voltage control of hydrogen-oxygen fuel cells: Feasibility study

NASA Technical Reports Server (NTRS)

Prokopius, P. R.

1975-01-01

An experimental study was conducted to assess the feasibility of internal voltage regulation of fuel cell systems. Two methods were tested. In one, reactant partial pressure was used as the voltage control parameter and in the other reactant total pressure was used for control. Both techniques were breadboarded and tested on a single alkaline-electrolyte fuel cell. Both methods were found to be possible forms of regulation, however, of the two the total pressure technique would be more efficient, simpler to apply and would provide better transient characteristics.

Hydrostatic pressure decreases membrane fluidity and lipid desaturase expression in chondrocyte progenitor cells.

PubMed

Montagne, Kevin; Uchiyama, Hiroki; Furukawa, Katsuko S; Ushida, Takashi

2014-01-22

Membrane biomechanical properties are critical in modulating nutrient and metabolite exchange as well as signal transduction. Biological membranes are predominantly composed of lipids, cholesterol and proteins, and their fluidity is tightly regulated by cholesterol and lipid desaturases. To determine whether such membrane fluidity regulation occurred in mammalian cells under pressure, we investigated the effects of pressure on membrane lipid order of mouse chondrogenic ATDC5 cells and desaturase gene expression. Hydrostatic pressure linearly increased membrane lipid packing and simultaneously repressed lipid desaturase gene expression. We also showed that cholesterol mimicked and cholesterol depletion reversed those effects, suggesting that desaturase gene expression was controlled by the membrane physical state itself. This study demonstrates a new effect of hydrostatic pressure on mammalian cells and may help to identify the molecular mechanisms involved in hydrostatic pressure sensing in chondrocytes. © 2013 Elsevier Ltd. All rights reserved.

Manipulation of norepinephrine metabolism with yohimbine in the treatment of autonomic failure

NASA Technical Reports Server (NTRS)

Biaggioni, I.; Robertson, R. M.; Robertson, D.

1994-01-01

It has been postulated that alpha 2-adrenergic receptors play a modulatory role in the regulation of blood pressure. Activation of alpha 2-receptors located in the central nervous system results in inhibition of sympathetic tone and decrease of blood pressure. This indeed may be the mechanism of action of central sympatholytic antihypertensives such as alpha-methyldopa. Presynaptic alpha 2-receptors also are found in adrenergic nerve terminals. These receptors act as a negative feedback mechanism by inhibiting the release of norepinephrine. The relevance of alpha 2-adrenergic receptors for blood pressure regulation can be explored with yohimbine, a selective antagonist of these receptors. Yohimbine increases blood pressure in resting normal volunteers. This effect is associated with an increase in both sympathetic nerve activity, reflecting an increase in central sympathetic outflow, and in norepinephrine spillover, reflecting potentiation of the release of norepinephrine from adrenergic nerve terminals. These actions, therefore, underscore the importance of alpha 2-adrenergic receptors for blood pressure regulation even under resting conditions. Patients with autonomic failure, even those with severe sympathetic deprivation, are hypersensitive to the pressor effects of yohimbine. This increased responsiveness can be explained by sensitization of adrenergic receptors, analogous to denervation supersensitivity, and by the lack of autonomic reflexes that would normally buffer any increase in blood pressure. Preliminary studies suggest that the effectiveness of yohimbine in autonomic failure can be enhanced with monoamine oxidase inhibitors. Used in combination, yohimbine increases norepinephrine release, whereas monoamine oxidase inhibitors inhibit its degradation. Therefore, yohimbine is not only a useful tool in the study of blood pressure regulation, but may offer a therapeutic option in autonomic dysfunction.

Trpv4 involvement in the sex differences in blood pressure regulation in spontaneously hypertensive rats.

PubMed

Onishi, Makiko; Yamanaka, Ko; Miyamoto, Yasunori; Waki, Hidefumi; Gouraud, Sabine

2018-04-01

Arterial pressure (AP) is lower in premenopausal women than in men of a similar age. Premenopausal women exhibit a lower sympathetic activity and a greater baroreceptor reflex; however, mechanisms controlling sex differences in blood pressure regulation are not well understood. We hypothesized that different neuronal functions in the cardiovascular centers of the brains of men and women may contribute to the sex difference in cardiovascular homeostasis. Our previous studies on male spontaneously hypertensive rats (SHRs) and their normotensive counterparts, Wistar Kyoto (WKY) rats, revealed that the gene-expression profile of the nucleus tractus solitarius (NTS), a region of the medulla oblongata that is pivotal for regulating the set point of AP, is strongly associated with AP. Thus, we hypothesized that gene-expression profiles in the rat NTS are related to sex differences in AP regulation. Because female SHRs clearly exhibit lower AP than their male counterparts of a similar age, we investigated whether SHR NTS exhibits sex differences in gene expression by using microarray and RT-qPCR experiments. The transcript for transient receptor potential cation channel subfamily V member 4 ( Trpv4) was found to be upregulated in SHR NTS in females compared with that in males. The channel was expressed in neurons and glial cells within NTS. The TRPV4 agonist 4-alpha-phorbol-12,13-didecanoate (4α-PDD) decreased blood pressure when injected into NTS of rats. These findings suggest that altered TRPV4 expression might be involved in the sex differences in blood pressure regulation.

Evidence for a GPR18 Role in Diurnal Regulation of Intraocular Pressure

PubMed Central

Miller, Sally; Leishman, Emma; Oehler, Olivia; Daily, Laura; Murataeva, Natalia; Wager-Miller, Jim; Bradshaw, Heather; Straiker, Alex

2016-01-01

Purpose The diurnal cycling of intraocular pressure (IOP) was first described in humans more than a century ago. This cycling is preserved in other species. The physiologic underpinning of this diurnal variation in IOP remains a mystery, even though elevated pressure is indicated in most forms of glaucoma, a common cause of blindness. Once identified, the system that underlies diurnal variation would represent a natural target for therapeutic intervention. Methods Using normotensive mice, we measured the regulation of ocular lipid species by the enzymes fatty acid amide hydrolase (FAAH) and N-arachidonoyl phosphatidylethanolamine phospholipase (NAPE-PLD), mRNA expression of these enzymes, and their functional role in diurnal regulation of IOP. Results We now report that NAPE-PLD and FAAH mice do not exhibit a diurnal cycling of IOP. These enzymes produce and break down acylethanolamines, including the endogenous cannabinoid anandamide. The diurnal lipid profile in mice shows that levels of most N-acyl ethanolamines and, intriguingly, N-arachidonoyl glycine (NAGly), decline at night: NAGly is a metabolite of arachidonoyl ethanolamine and a potent agonist at GPR18 that lowers intraocular pressure. The GPR18 blocker O1918 raises IOP during the day when pressure is low, but not at night. Quantitative PCR analysis shows that FAAH mRNA levels rise with pressure, suggesting that FAAH mediates the changes in pressure. Conclusions Our results support FAAH-dependent NAGly action at GPR18 as the physiologic basis of the diurnal variation of intraocular pressure in mice. PMID:27893106

Autonomic control of body temperature and blood pressure: influences of female sex hormones.

PubMed

Charkoudian, Nisha; Hart, Emma C J; Barnes, Jill N; Joyner, Michael J

2017-06-01

Female reproductive hormones exert important non-reproductive influences on autonomic regulation of body temperature and blood pressure. Estradiol and progesterone influence thermoregulation both centrally and peripherally, where estradiol tends to promote heat dissipation, and progesterone tends to promote heat conservation and higher body temperatures. Changes in thermoregulation over the course of the menstrual cycle and with hot flashes at menopause are mediated by hormonal influences on neural control of skin blood flow and sweating. The influence of estradiol is to promote vasodilation, which, in the skin, results in greater heat dissipation. In the context of blood pressure regulation, both central and peripheral hormonal influences are important as well. Peripherally, the vasodilator influence of estradiol contributes to the lower blood pressures and smaller risk of hypertension seen in young women compared to young men. This is in part due to a mechanism by which estradiol augments beta-adrenergic receptor mediated vasodilation, offsetting alpha-adrenergic vasoconstriction, and resulting in a weak relationship between muscle sympathetic nerve activity and total peripheral resistance, and between muscle sympathetic nerve activity and blood pressure. After menopause, with the loss of reproductive hormones, sympathetic nerve activity, peripheral resistance and blood pressure become more strongly related, and sympathetic nerve activity (which increases with age) becomes a more important contributor to the prevailing level of blood pressure. Continuing to increase our understanding of sex hormone influences on body temperature and blood pressure regulation will provide important insight for optimization of individualized health care for future generations of women.

Urotensin II inhibited the proliferation of cardiac side population cells in mice during pressure overload by JNK-LRP6 signalling

PubMed Central

Chen, Zhidan; Xu, Jiahong; Ye, Yong; Li, Yang; Gong, Hui; Zhang, Guoping; Wu, Jian; jia, Jianguo; Liu, Ming; Chen, Ying; Yang, Chunjie; Tang, Yu; Zhu, Yichun; Ge, Junbo; Zou, Yunzeng

2014-01-01

Cardiac side population cells (CSPs) are promising cell resource for the regeneration in diseased heart as intrinsic cardiac stem cells. However, the relative low ratio of CSPs in the heart limited the ability of CSPs to repair heart and improve cardiac function effectively under pathophysiological condition. Which factors limiting the proliferation of CSPs in diseased heart are unclear. Here, we show that urotensin II (UII) regulates the proliferation of CSPs by c-Jun N-terminal kinase (JNK) and low density lipoprotein receptor-related protein 6 (LRP6) signalling during pressure overload. Pressure overload greatly upregulated UII level in plasma, UII receptor (UT) antagonist, urantide, promoted CSPs proliferation and improved cardiac dysfunction during chronic pressure overload. In cultured CSPs subjected to mechanical stretch (MS), UII significantly inhibited the proliferation by UT. Nanofluidic proteomic immunoassay showed that it is the JNK activation, but not the extracellular signal-regulated kinase signalling, that involved in the UII-inhibited- proliferation of CSPs during pressure overload. Further analysis in vitro indicated UII-induced-phospho-JNK regulates phosphorylation of LRP6 in cultured CSPs after MS, which is important in the inhibitory effect of UII on the CSPs during pressure overload. In conclusion, UII inhibited the proliferation of CSPs by JNK/LRP6 signalling during pressure overload. Pharmacological inhibition of UII promotes CSPs proliferation in mice, offering a possible therapeutic approach for cardiac failure induced by pressure overload. PMID:24447593

Regulation of landslide motion by dilatancy and pore pressure feedback

USGS Publications Warehouse

Iverson, R.M.

2005-01-01

A new mathematical model clarifies how diverse styles and rates of landslide motion can result from regulation of Coulomb friction by dilation or contraction of water-saturated basal shear zones. Normalization of the model equations shows that feedback due to coupling between landslide motion, shear zone volume change, and pore pressure change depends on a single dimensionless parameter ??, which, in turn, depends on the dilatancy angle ?? and the intrinsic timescales for pore pressure generation and dissipation. If shear zone soil contracts during slope failure, then ?? 0, and negative feedback permits slow, steady landslide motion to occur while positive pore pressure is supplied by rain infiltration. Steady state slip velocities v0 obey v0 = -(K/??) p*e, where K is the hydraulic conductivity and p*e is the normalized (dimensionless) negative pore pressure generated by dilation. If rain infiltration and attendant pore pressure growth continue unabated, however, their influence ultimately overwhelms the stabilizing influence of negative p*e. Then, unbounded landslide acceleration occurs, accentuated by an instability that develops if ?? diminishes as landslide motion proceeds. Nonetheless, numerical solutions of the model equations show that slow, nearly steady motion of a clay-rich landslide may persist for many months as a result of negative pore pressure feedback that regulates basal Coulomb friction. Similarly stabilized motion is less likely to occur in sand-rich landslides that are characterized by weaker negative feedback.

Study on the technology of dual-tube layered injection in ASP flooding

NASA Astrophysics Data System (ADS)

Yang, Ye; Zhang, Yongping; Xu, Dekui; Cai, Meng; Yang, Zhigang; Wang, Hailong; Song, Xingliang

2017-10-01

For the single-tube layered injection technology cannot solve the problem of interlayer pressure difference is greater than 2MPa injection wells, through the development of dual-tube packer, dual-tube injection allocator, downhole plug, the ground pressure regulator and molecular weight regulator. Dual-tube layered injection technology is formed. According to the data of ASP flooding injection wells in the field, the whole well is divided into high permeability and low permeability oil reservoir. Two separate injection channels can be formed by using dual-tube packer and dual-tube injection allocator. Through the use of the ground pressure regulator, the problem of the high permeability layer and low permeability layer of the injection pressure difference is solved. Through the use of the ground molecular weight regulator, the problem that the same molecular weight ASP solution is not suitable for high and low permeability is solved. By replacing the downhole plug, the grouping transformation of some oil layer can be achieved. The experiment and field application of 3 wells results show that: the flow control range is 20m3/d-70m3/d; the max. Throttling differential pressure is 3.5MPa; the viscosity loss rate of solution is less than 5%; and the molecular weight adjusting range is 20%-50%. The utilization degree of oil layer is obviously increased through the use of the dual-tube layered injection technology.

Role of NO in choroidal blood flow regulation during isometric exercise in healthy humans.

PubMed

Luksch, Alexandra; Polska, Elzbieta; Imhof, Andrea; Schering, Joanne; Fuchsjäger-Mayrl, Gabriele; Wolzt, Michael; Schmetterer, Leopold

2003-02-01

Nitric oxide (NO) is an important regulator of basal choroidal blood flow. Animal experiments indicate that NO is also involved in choroidal blood flow regulation during changes in ocular perfusion pressure and inhibition of NO synthase (NOS) has been reported to shift choroidal pressure-flow curves to the right. The hypothesis for the study was that inhibition of NOS may influence choroidal blood flow during isometric exercise. To test this hypothesis, a randomized, double-masked, placebo-controlled, three-way crossover study was performed in 12 healthy male volunteers. Subjects received on different study days intravenous infusions of N(G)-monomethyl-L-arginine (L-NMMA), phenylephrine, or placebo. During these infusion periods, subjects were asked to squat for 6 minutes. Choroidal blood flow was assessed with laser Doppler flowmetry, and ocular perfusion pressure (OPP) was calculated from mean arterial pressure and intraocular pressure. L-NMMA and phenylephrine increased resting OPP by 10% and 13%, respectively, but only L-NMMA reduced resting choroidal blood flow (-17%, P < 0.001). The relative increase in OPP during isometric exercise was comparable with all drugs administered. Isometric exercise increased choroidal blood flow during administration of placebo and phenylephrine, but not during administration of L-NMMA (P < 0.001 vs. placebo). These data indicate that NO plays an important role in the regulation of choroidal blood flow during isometric exercise.

Passive flow regulators for drug delivery and hydrocephalus treatment

NASA Astrophysics Data System (ADS)

Chappel, E.; Dumont-Fillon, D.; Mefti, S.

2014-03-01

Passive flow regulators are usually intended to deliver or drain a fluid at a constant rate independently from pressure variations. New designs of passive flow regulators made of a stack of a silicon membrane anodically bonded to a Pyrex substrate are proposed. A first design has been built for the derivation of cerebrospinal fluid (CSF) towards peritoneum for hydrocephalus treatment. The device allows draining CSF at the patient production rate independently from postural changes. The flow rate is regulated at 20 ml/h in the range 10 to 40 mbar. Specific features to adjust in vivo the nominal flow rate are shown. A second design including high pressure shut-off feature has been made. The intended use is drug delivery with pressurized reservoir of typically 100 to 300 mbar. In both cases, the membrane comprises several holes facing pillars in the Pyrex substrate. These pillars are machined in a cavity which ensures a gap between the membrane and the pillars at rest. The fluid in the pressurized reservoir is directly in contact with the top surface of the membrane, inducing its deflection towards Pyrex substrate and closing progressively the fluidic pathway through each hole of the membrane. Since the membrane deflection is highly non-linear, FEM simulations have been performed to determine both radial position and diameter of the membrane holes that ensure a constant flow rate for a given range of pressure.

Linking Self-Regulation and Risk Proneness to Risky Sexual Behavior: Pathways through Peer Pressure and Early Substance Use

ERIC Educational Resources Information Center

Crockett, Lisa J.; Raffaelli, Marcela; Shen, Yuh-Ling

2006-01-01

The linkages between self-regulation in childhood, risk proneness in early adolescence, and risky sexual behavior in mid-adolescence were examined in a cohort of children (N=518) from the National Longitudinal Survey of Youth. The possible mediating role of two early adolescent variables (substance use and negative peer pressure) was also…

The genetics of blood pressure regulation and its target organs from association studies in 342,415 individuals.

PubMed

Ehret, Georg B; Ferreira, Teresa; Chasman, Daniel I; Jackson, Anne U; Schmidt, Ellen M; Johnson, Toby; Thorleifsson, Gudmar; Luan, Jian'an; Donnelly, Lousie A; Kanoni, Stavroula; Petersen, Ann-Kristin; Pihur, Vasyl; Strawbridge, Rona J; Shungin, Dmitry; Hughes, Maria F; Meirelles, Osorio; Kaakinen, Marika; Bouatia-Naji, Nabila; Kristiansson, Kati; Shah, Sonia; Kleber, Marcus E; Guo, Xiuqing; Lyytikäinen, Leo-Pekka; Fava, Cristiano; Eriksson, Niclas; Nolte, Ilja M; Magnusson, Patrik K; Salfati, Elias L; Rallidis, Loukianos S; Theusch, Elizabeth; Smith, Andrew J P; Folkersen, Lasse; Witkowska, Kate; Pers, Tune H; Joehanes, Roby; Kim, Stuart K; Lataniotis, Lazaros; Jansen, Rick; Johnson, Andrew D; Warren, Helen; Kim, Young Jin; Zhao, Wei; Wu, Ying; Tayo, Bamidele O; Bochud, Murielle; Absher, Devin; Adair, Linda S; Amin, Najaf; Arking, Dan E; Axelsson, Tomas; Baldassarre, Damiano; Balkau, Beverley; Bandinelli, Stefania; Barnes, Michael R; Barroso, Inês; Bevan, Stephen; Bis, Joshua C; Bjornsdottir, Gyda; Boehnke, Michael; Boerwinkle, Eric; Bonnycastle, Lori L; Boomsma, Dorret I; Bornstein, Stefan R; Brown, Morris J; Burnier, Michel; Cabrera, Claudia P; Chambers, John C; Chang, I-Shou; Cheng, Ching-Yu; Chines, Peter S; Chung, Ren-Hua; Collins, Francis S; Connell, John M; Döring, Angela; Dallongeville, Jean; Danesh, John; de Faire, Ulf; Delgado, Graciela; Dominiczak, Anna F; Doney, Alex S F; Drenos, Fotios; Edkins, Sarah; Eicher, John D; Elosua, Roberto; Enroth, Stefan; Erdmann, Jeanette; Eriksson, Per; Esko, Tonu; Evangelou, Evangelos; Evans, Alun; Fall, Tove; Farrall, Martin; Felix, Janine F; Ferrières, Jean; Ferrucci, Luigi; Fornage, Myriam; Forrester, Terrence; Franceschini, Nora; Duran, Oscar H Franco; Franco-Cereceda, Anders; Fraser, Ross M; Ganesh, Santhi K; Gao, He; Gertow, Karl; Gianfagna, Francesco; Gigante, Bruna; Giulianini, Franco; Goel, Anuj; Goodall, Alison H; Goodarzi, Mark O; Gorski, Mathias; Gräßler, Jürgen; Groves, Christopher; Gudnason, Vilmundur; Gyllensten, Ulf; Hallmans, Göran; Hartikainen, Anna-Liisa; Hassinen, Maija; Havulinna, Aki S; Hayward, Caroline; Hercberg, Serge; Herzig, Karl-Heinz; Hicks, Andrew A; Hingorani, Aroon D; Hirschhorn, Joel N; Hofman, Albert; Holmen, Jostein; Holmen, Oddgeir Lingaas; Hottenga, Jouke-Jan; Howard, Phil; Hsiung, Chao A; Hunt, Steven C; Ikram, M Arfan; Illig, Thomas; Iribarren, Carlos; Jensen, Richard A; Kähönen, Mika; Kang, Hyun; Kathiresan, Sekar; Keating, Brendan J; Khaw, Kay-Tee; Kim, Yun Kyoung; Kim, Eric; Kivimaki, Mika; Klopp, Norman; Kolovou, Genovefa; Komulainen, Pirjo; Kooner, Jaspal S; Kosova, Gulum; Krauss, Ronald M; Kuh, Diana; Kutalik, Zoltan; Kuusisto, Johanna; Kvaløy, Kirsti; Lakka, Timo A; Lee, Nanette R; Lee, I-Te; Lee, Wen-Jane; Levy, Daniel; Li, Xiaohui; Liang, Kae-Woei; Lin, Honghuang; Lin, Li; Lindström, Jaana; Lobbens, Stéphane; Männistö, Satu; Müller, Gabriele; Müller-Nurasyid, Martina; Mach, François; Markus, Hugh S; Marouli, Eirini; McCarthy, Mark I; McKenzie, Colin A; Meneton, Pierre; Menni, Cristina; Metspalu, Andres; Mijatovic, Vladan; Moilanen, Leena; Montasser, May E; Morris, Andrew D; Morrison, Alanna C; Mulas, Antonella; Nagaraja, Ramaiah; Narisu, Narisu; Nikus, Kjell; O'Donnell, Christopher J; O'Reilly, Paul F; Ong, Ken K; Paccaud, Fred; Palmer, Cameron D; Parsa, Afshin; Pedersen, Nancy L; Penninx, Brenda W; Perola, Markus; Peters, Annette; Poulter, Neil; Pramstaller, Peter P; Psaty, Bruce M; Quertermous, Thomas; Rao, Dabeeru C; Rasheed, Asif; Rayner, N William N W R; Renström, Frida; Rettig, Rainer; Rice, Kenneth M; Roberts, Robert; Rose, Lynda M; Rossouw, Jacques; Samani, Nilesh J; Sanna, Serena; Saramies, Jouko; Schunkert, Heribert; Sebert, Sylvain; Sheu, Wayne H-H; Shin, Young-Ah; Sim, Xueling; Smit, Johannes H; Smith, Albert V; Sosa, Maria X; Spector, Tim D; Stančáková, Alena; Stanton, Alice; Stirrups, Kathleen E; Stringham, Heather M; Sundstrom, Johan; Swift, Amy J; Syvänen, Ann-Christine; Tai, E-Shyong; Tanaka, Toshiko; Tarasov, Kirill V; Teumer, Alexander; Thorsteinsdottir, Unnur; Tobin, Martin D; Tremoli, Elena; Uitterlinden, Andre G; Uusitupa, Matti; Vaez, Ahmad; Vaidya, Dhananjay; van Duijn, Cornelia M; van Iperen, Erik P A; Vasan, Ramachandran S; Verwoert, Germaine C; Virtamo, Jarmo; Vitart, Veronique; Voight, Benjamin F; Vollenweider, Peter; Wagner, Aline; Wain, Louise V; Wareham, Nicholas J; Watkins, Hugh; Weder, Alan B; Westra, Harm-Jan; Wilks, Rainford; Wilsgaard, Tom; Wilson, James F; Wong, Tien Y; Yang, Tsun-Po; Yao, Jie; Yengo, Loic; Zhang, Weihua; Zhao, Jing Hua; Zhu, Xiaofeng; Bovet, Pascal; Cooper, Richard S; Mohlke, Karen L; Saleheen, Danish; Lee, Jong-Young; Elliott, Paul; Gierman, Hinco J; Willer, Cristen J; Franke, Lude; Hovingh, G Kees; Taylor, Kent D; Dedoussis, George; Sever, Peter; Wong, Andrew; Lind, Lars; Assimes, Themistocles L; Njølstad, Inger; Schwarz, Peter Eh; Langenberg, Claudia; Snieder, Harold; Caulfield, Mark J; Melander, Olle; Laakso, Markku; Saltevo, Juha; Rauramaa, Rainer; Tuomilehto, Jaakko; Ingelsson, Erik; Lehtimäki, Terho; Hveem, Kristian; Palmas, Walter; März, Winfried; Kumari, Meena; Salomaa, Veikko; Chen, Yii-Der I; Rotter, Jerome I; Froguel, Philippe; Jarvelin, Marjo-Riitta; Lakatta, Edward G; Kuulasmaa, Kari; Franks, Paul W; Hamsten, Anders; Wichmann, H-Erich; Palmer, Colin N A; Stefansson, Kari; Ridker, Paul M; Loos, Ruth J F; Chakravarti, Aravinda; Deloukas, Panos; Morris, Andrew P; Newton-Cheh, Christopher; Munroe, Patricia B

2016-10-01

To dissect the genetic architecture of blood pressure and assess effects on target organ damage, we analyzed 128,272 SNPs from targeted and genome-wide arrays in 201,529 individuals of European ancestry, and genotypes from an additional 140,886 individuals were used for validation. We identified 66 blood pressure-associated loci, of which 17 were new; 15 harbored multiple distinct association signals. The 66 index SNPs were enriched for cis-regulatory elements, particularly in vascular endothelial cells, consistent with a primary role in blood pressure control through modulation of vascular tone across multiple tissues. The 66 index SNPs combined in a risk score showed comparable effects in 64,421 individuals of non-European descent. The 66-SNP blood pressure risk score was significantly associated with target organ damage in multiple tissues but with minor effects in the kidney. Our findings expand current knowledge of blood pressure-related pathways and highlight tissues beyond the classical renal system in blood pressure regulation.

The genetics of blood pressure regulation and its target organs from association studies in 342,415 individuals

PubMed Central

Chasman, Daniel I.; Jackson, Anne U.; Schmidt, Ellen M.; Johnson, Toby; Thorleifsson, Gudmar; Luan, Jian'an; Donnelly, Lousie A.; Kanoni, Stavroula; Petersen, Ann-Kristin; Pihur, Vasyl; Strawbridge, Rona J.; Shungin, Dmitry; Hughes, Maria F.; Meirelles, Osorio; Kaakinen, Marika; Bouatia-Naji, Nabila; Kristiansson, Kati; Shah, Sonia; Kleber, Marcus E.; Guo, Xiuqing; Lyytikäinen, Leo-Pekka; Fava, Cristiano; Eriksson, Niclas; Nolte, Ilja M.; Magnusson, Patrik K.; Salfati, Elias L.; Rallidis, Loukianos S.; Theusch, Elizabeth; Smith, Andrew J.P.; Folkersen, Lasse; Witkowska, Kate; Pers, Tune H.; Joehanes, Roby; Kim, Stuart K.; Lataniotis, Lazaros; Jansen, Rick; Johnson, Andrew D.; Warren, Helen; Kim, Young Jin; Zhao, Wei; Wu, Ying; Tayo, Bamidele O.; Bochud, Murielle; Absher, Devin; Adair, Linda S.; Amin, Najaf; Arking, Dan E.; Axelsson, Tomas; Baldassarre, Damiano; Balkau, Beverley; Bandinelli, Stefania; Barnes, Michael R.; Barroso, Inês; Bevan, Stephen; Bis, Joshua C.; Bjornsdottir, Gyda; Boehnke, Michael; Boerwinkle, Eric; Bonnycastle, Lori L.; Boomsma, Dorret I.; Bornstein, Stefan R.; Brown, Morris J.; Burnier, Michel; Cabrera, Claudia P.; Chambers, John C.; Chang, I-Shou; Cheng, Ching-Yu; Chines, Peter S.; Chung, Ren-Hua; Collins, Francis S.; Connell, John M.; Döring, Angela; Dallongeville, Jean; Danesh, John; de Faire, Ulf; Delgado, Graciela; Dominiczak, Anna F.; Doney, Alex S.F.; Drenos, Fotios; Edkins, Sarah; Eicher, John D.; Elosua, Roberto; Enroth, Stefan; Erdmann, Jeanette; Eriksson, Per; Esko, Tonu; Evangelou, Evangelos; Evans, Alun; Fall, Tove; Farrall, Martin; Felix, Janine F.; Ferrières, Jean; Ferrucci, Luigi; Fornage, Myriam; Forrester, Terrence; Franceschini, Nora; Duran, Oscar H. Franco; Franco-Cereceda, Anders; Fraser, Ross M.; Ganesh, Santhi K.; Gao, He; Gertow, Karl; Gianfagna, Francesco; Gigante, Bruna; Giulianini, Franco; Goel, Anuj; Goodall, Alison H.; Goodarzi, Mark O.; Gorski, Mathias; Gräßler, Jürgen; Groves, Christopher; Gudnason, Vilmundur; Gyllensten, Ulf; Hallmans, Göran; Hartikainen, Anna-Liisa; Hassinen, Maija; Havulinna, Aki S.; Hayward, Caroline; Hercberg, Serge; Herzig, Karl-Heinz; Hicks, Andrew A.; Hingorani, Aroon D.; Hirschhorn, Joel N.; Hofman, Albert; Holmen, Jostein; Holmen, Oddgeir Lingaas; Hottenga, Jouke-Jan; Howard, Phil; Hsiung, Chao A.; Hunt, Steven C.; Ikram, M. Arfan; Illig, Thomas; Iribarren, Carlos; Jensen, Richard A.; Kähönen, Mika; Kang, Hyun; Kathiresan, Sekar; Keating, Brendan J.; Khaw, Kay-Tee; Kim, Yun Kyoung; Kim, Eric; Kivimaki, Mika; Klopp, Norman; Kolovou, Genovefa; Komulainen, Pirjo; Kooner, Jaspal S.; Kosova, Gulum; Krauss, Ronald M.; Kuh, Diana; Kutalik, Zoltan; Kuusisto, Johanna; Kvaløy, Kirsti; Lakka, Timo A; Lee, Nanette R.; Lee, I-Te; Lee, Wen-Jane; Levy, Daniel; Li, Xiaohui; Liang, Kae-Woei; Lin, Honghuang; Lin, Li; Lindström, Jaana; Lobbens, Stéphane; Männistö, Satu; Müller, Gabriele; Müller-Nurasyid, Martina; Mach, François; Markus, Hugh S.; Marouli, Eirini; McCarthy, Mark I.; McKenzie, Colin A.; Meneton, Pierre; Menni, Cristina; Metspalu, Andres; Mijatovic, Vladan; Moilanen, Leena; Montasser, May E.; Morris, Andrew D.; Morrison, Alanna C.; Mulas, Antonella; Nagaraja, Ramaiah; Narisu, Narisu; Nikus, Kjell; O'Donnell, Christopher J.; O'Reilly, Paul F.; Ong, Ken K.; Paccaud, Fred; Palmer, Cameron D.; Parsa, Afshin; Pedersen, Nancy L.; Penninx, Brenda W.; Perola, Markus; Peters, Annette; Poulter, Neil; Pramstaller, Peter P.; Psaty, Bruce M.; Quertermous, Thomas; Rao, Dabeeru C.; Rasheed, Asif; Rayner, N William N.W.R.; Renström, Frida; Rettig, Rainer; Rice, Kenneth M.; Roberts, Robert; Rose, Lynda M.; Rossouw, Jacques; Samani, Nilesh J.; Sanna, Serena; Saramies, Jouko; Schunkert, Heribert; Sebert, Sylvain; Sheu, Wayne H.-H.; Shin, Young-Ah; Sim, Xueling; Smit, Johannes H.; Smith, Albert V.; Sosa, Maria X.; Spector, Tim D.; Stančáková, Alena; Stanton, Alice; Stirrups, Kathleen E.; Stringham, Heather M.; Sundstrom, Johan; Swift, Amy J.; Syvänen, Ann-Christine; Tai, E-Shyong; Tanaka, Toshiko; Tarasov, Kirill V.; Teumer, Alexander; Thorsteinsdottir, Unnur; Tobin, Martin D.; Tremoli, Elena; Uitterlinden, Andre G.; Uusitupa, Matti; Vaez, Ahmad; Vaidya, Dhananjay; van Duijn, Cornelia M.; van Iperen, Erik P.A.; Vasan, Ramachandran S.; Verwoert, Germaine C.; Virtamo, Jarmo; Vitart, Veronique; Voight, Benjamin F.; Vollenweider, Peter; Wagner, Aline; Wain, Louise V.; Wareham, Nicholas J.; Watkins, Hugh; Weder, Alan B.; Westra, Harm-Jan; Wilks, Rainford; Wilsgaard, Tom; Wilson, James F.; Wong, Tien Y.; Yang, Tsun-Po; Yao, Jie; Yengo, Loic; Zhang, Weihua; Zhao, Jing Hua; Zhu, Xiaofeng; Bovet, Pascal; Cooper, Richard S.; Mohlke, Karen L.; Saleheen, Danish; Lee, Jong-Young; Elliott, Paul; Gierman, Hinco J.; Willer, Cristen J.; Franke, Lude; Hovingh, G Kees; Taylor, Kent D.; Dedoussis, George; Sever, Peter; Wong, Andrew; Lind, Lars; Assimes, Themistocles L.; Njølstad, Inger; Schwarz, Peter EH.; Langenberg, Claudia; Snieder, Harold; Caulfield, Mark J.; Melander, Olle; Laakso, Markku; Saltevo, Juha; Rauramaa, Rainer; Tuomilehto, Jaakko; Ingelsson, Erik; Lehtimäki, Terho; Hveem, Kristian; Palmas, Walter; März, Winfried; Kumari, Meena; Salomaa, Veikko; Chen, Yii-Der I.; Rotter, Jerome I.; Froguel, Philippe; Jarvelin, Marjo-Riitta; Lakatta, Edward G.; Kuulasmaa, Kari; Franks, Paul W.; Hamsten, Anders; Wichmann, H.-Erich; Palmer, Colin N.A.; Stefansson, Kari; Ridker, Paul M; Loos, Ruth J.F.; Chakravarti, Aravinda; Deloukas, Panos; Morris, Andrew P.; Newton-Cheh, Christopher; Munroe, Patricia B.

2016-01-01

To dissect the genetic architecture of blood pressure and assess effects on target-organ damage, we analyzed 128,272 SNPs from targeted and genome-wide arrays in 201,529 individuals of European ancestry and genotypes from an additional 140,886 individuals were used for validation. We identified 66 blood pressure loci, of which 17 were novel and 15 harbored multiple distinct association signals. The 66 index SNPs were enriched for cis-regulatory elements, particularly in vascular endothelial cells, consistent with a primary role in blood pressure control through modulation of vascular tone across multiple tissues. The 66 index SNPs combined in a risk score showed comparable effects in 64,421 individuals of non-European descent. The 66-SNP blood pressure risk score was significantly associated with target-organ damage in multiple tissues, with minor effects in the kidney. Our findings expand current knowledge of blood pressure pathways and highlight tissues beyond the classic renal system in blood pressure regulation. PMID:27618452

Neural Regulation of Cardiovascular Response to Exercise: Role of Central Command and Peripheral Afferents

PubMed Central

Nobrega, Antonio C. L.; O'Leary, Donal; Silva, Bruno Moreira; Piepoli, Massimo F.; Crisafulli, Antonio

2014-01-01

During dynamic exercise, mechanisms controlling the cardiovascular apparatus operate to provide adequate oxygen to fulfill metabolic demand of exercising muscles and to guarantee metabolic end-products washout. Moreover, arterial blood pressure is regulated to maintain adequate perfusion of the vital organs without excessive pressure variations. The autonomic nervous system adjustments are characterized by a parasympathetic withdrawal and a sympathetic activation. In this review, we briefly summarize neural reflexes operating during dynamic exercise. The main focus of the present review will be on the central command, the arterial baroreflex and chemoreflex, and the exercise pressure reflex. The regulation and integration of these reflexes operating during dynamic exercise and their possible role in the pathophysiology of some cardiovascular diseases are also discussed. PMID:24818143

Baroreflex sensitivity in acute hypoxia and carbohydrate loading.

PubMed

Klemenc, Matjaž; Golja, Petra

2011-10-01

Hypoxia decreases baroreflex sensitivity (BRS) and can be a sufficient cause for syncope in healthy individuals. Carbohydrate loading enhances efferent sympathetic activity, which affects cardiac contractility, heart rate and vascular resistance, the main determinants of blood pressure. Thus, in both normoxia and hypoxia, carbohydrate loading may be more than simply metabolically beneficial, as it may affect blood pressure regulation. We hypothesised that carbohydrate loading will, in both normoxia and hypoxia, alter the regulation of blood pressure, as reflected in a change in baroreflex sensitivity. Fourteen subjects participated in two experiments, composed of a 15-min normoxic period, after which the subjects ingested water or an equal amount of water with carbohydrates. A 30-min rest period was then followed by a 10-min second normoxic and a 30-min hypoxic period. Blood pressure and heart rate were monitored continuously during the experiment to determine BRS. Despite an increased sympathetic activation, reflected in increased heart rate (P < 0.001) BRS was lower (P < 0.01) after carbohydrate loading, as compared to the water experiment, in both normoxic [23.7 (12.4) versus 28.8 (13.8) ms/mmHg] and hypoxic [16.8 (11.0) versus 24.3 (12.3) ms/mmHg] phases of the present study. As BRS was decreased in acute hypoxic exposure, the results confirm that hypoxia interferes with blood pressure regulation. However, although oral carbohydrate loading induced sympathoexcitation, it did not improve blood pressure regulation in hypoxia, as evident from the BRS data. Baroreflex effects of other forms of carbohydrate loading, not causing postprandial blood shifts to digestive system, should therefore be investigated.

49 CFR 179.201 - Individual specification requirements applicable to non-pressure tank car tanks.

Code of Federal Regulations, 2013 CFR

2013-10-01

... to non-pressure tank car tanks. 179.201 Section 179.201 Transportation Other Regulations Relating to... (CONTINUED) SPECIFICATIONS FOR TANK CARS Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.201 Individual specification requirements applicable to non-pressure tank car tanks. ...

49 CFR 179.201 - Individual specification requirements applicable to non-pressure tank car tanks.

Code of Federal Regulations, 2012 CFR

2012-10-01

... to non-pressure tank car tanks. 179.201 Section 179.201 Transportation Other Regulations Relating to... (CONTINUED) SPECIFICATIONS FOR TANK CARS Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.201 Individual specification requirements applicable to non-pressure tank car tanks. ...

49 CFR 179.201 - Individual specification requirements applicable to non-pressure tank car tanks.

Code of Federal Regulations, 2011 CFR

2011-10-01

... to non-pressure tank car tanks. 179.201 Section 179.201 Transportation Other Regulations Relating to... (CONTINUED) SPECIFICATIONS FOR TANK CARS Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.201 Individual specification requirements applicable to non-pressure tank car tanks. ...

49 CFR 178.69 - Responsibilities and requirements for manufacturers of UN pressure receptacles.

Code of Federal Regulations, 2014 CFR

2014-10-01

... manufacturers of UN pressure receptacles. 178.69 Section 178.69 Transportation Other Regulations Relating to... requirements for manufacturers of UN pressure receptacles. (a) Each manufacturer of a UN pressure receptacle marked with “USA” as a country of approval must comply with the requirements in this section. The...

49 CFR 178.69 - Responsibilities and requirements for manufacturers of UN pressure receptacles.

Code of Federal Regulations, 2011 CFR

2011-10-01

... manufacturers of UN pressure receptacles. 178.69 Section 178.69 Transportation Other Regulations Relating to... requirements for manufacturers of UN pressure receptacles. (a) Each manufacturer of a UN pressure receptacle marked with “USA” as a country of approval must comply with the requirements in this section. The...

49 CFR 178.69 - Responsibilities and requirements for manufacturers of UN pressure receptacles.

Code of Federal Regulations, 2013 CFR

2013-10-01

... manufacturers of UN pressure receptacles. 178.69 Section 178.69 Transportation Other Regulations Relating to... requirements for manufacturers of UN pressure receptacles. (a) Each manufacturer of a UN pressure receptacle marked with “USA” as a country of approval must comply with the requirements in this section. The...

49 CFR 178.69 - Responsibilities and requirements for manufacturers of UN pressure receptacles.

Code of Federal Regulations, 2012 CFR

2012-10-01

... manufacturers of UN pressure receptacles. 178.69 Section 178.69 Transportation Other Regulations Relating to... requirements for manufacturers of UN pressure receptacles. (a) Each manufacturer of a UN pressure receptacle marked with “USA” as a country of approval must comply with the requirements in this section. The...

Remotely operated high pressure valve protects test personnel

NASA Technical Reports Server (NTRS)

Howland, B. T.

1967-01-01

High pressure valve used in testing certain spacecraft systems is safely opened and closed by a remotely stationed operator. The valve is self-regulating in that if the incoming pressure drops below a desired value the valve will automatically close, warning the operator that the testing pressure has dropped to an undesired level.

49 CFR 173.301b - Additional general requirements for shipment of UN pressure receptacles.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Group I performance level. (d) Non-refillable UN pressure receptacles. (1) When the use of a valve is... pressure receptacles. 173.301b Section 173.301b Transportation Other Regulations Relating to Transportation....301b Additional general requirements for shipment of UN pressure receptacles. (a) General. The...

49 CFR 173.301b - Additional general requirements for shipment of UN pressure receptacles.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Group I performance level. (d) Non-refillable UN pressure receptacles. (1) When the use of a valve is... pressure receptacles. 173.301b Section 173.301b Transportation Other Regulations Relating to Transportation....301b Additional general requirements for shipment of UN pressure receptacles. (a) General. The...

Helium process cycle

DOEpatents

Ganni, Venkatarao

2008-08-12

A unique process cycle and apparatus design separates the consumer (cryogenic) load return flow from most of the recycle return flow of a refrigerator and/or liquefier process cycle. The refrigerator and/or liquefier process recycle return flow is recompressed by a multi-stage compressor set and the consumer load return flow is recompressed by an independent consumer load compressor set that maintains a desirable constant suction pressure using a consumer load bypass control valve and the consumer load return pressure control valve that controls the consumer load compressor's suction pressure. The discharge pressure of this consumer load compressor is thereby allowed to float at the intermediate pressure in between the first and second stage recycle compressor sets. Utilizing the unique gas management valve regulation, the unique process cycle and apparatus design in which the consumer load return flow is separate from the recycle return flow, the pressure ratios of each recycle compressor stage and all main pressures associated with the recycle return flow are allowed to vary naturally, thus providing a naturally regulated and balanced floating pressure process cycle that maintains optimal efficiency at design and off-design process cycle capacity and conditions automatically.

Helium process cycle

DOEpatents

Ganni, Venkatarao

2007-10-09

A unique process cycle and apparatus design separates the consumer (cryogenic) load return flow from most of the recycle return flow of a refrigerator and/or liquefier process cycle. The refrigerator and/or liquefier process recycle return flow is recompressed by a multi-stage compressor set and the consumer load return flow is recompressed by an independent consumer load compressor set that maintains a desirable constant suction pressure using a consumer load bypass control valve and the consumer load return pressure control valve that controls the consumer load compressor's suction pressure. The discharge pressure of this consumer load compressor is thereby allowed to float at the intermediate pressure in between the first and second stage recycle compressor sets. Utilizing the unique gas management valve regulation, the unique process cycle and apparatus design in which the consumer load return flow is separate from the recycle return flow, the pressure ratios of each recycle compressor stage and all main pressures associated with the recycle return flow are allowed to vary naturally, thus providing a naturally regulated and balanced floating pressure process cycle that maintains optimal efficiency at design and off-design process cycle capacity and conditions automatically.

Space shuttle OMS helium regulator design and development

NASA Technical Reports Server (NTRS)

Wichmann, H.; Kelly, T. L.; Lynch, R.

1974-01-01

Analysis, design, fabrication and design verification testing was conducted on the technological feasiblity of the helium pressurization regulator for the space shuttle orbital maneuvering system application. A prototype regulator was fabricated which was a single-stage design featuring the most reliable and lowest cost concept. A tradeoff study on regulator concepts indicated that a single-stage regulator with a lever arm between the valve and the actuator section would offer significant weight savings. Damping concepts were tested to determine the amount of damping required to restrict actuator travel during vibration. Component design parameters such as spring rates, effective area, contamination cutting, and damping were determined by test prior to regulator final assembly. The unit was subjected to performance testing at widely ranging flow rates, temperatures, inlet pressures, and random vibration levels. A test plan for propellant compatibility and extended life tests is included.

AUTOMATED TECHNIQUE FOR FLOW MEASUREMENTS FROM MARIOTTE RESERVOIRS.

USGS Publications Warehouse

Constantz, Jim; Murphy, Fred

1987-01-01

The mariotte reservoir supplies water at a constant hydraulic pressure by self-regulation of its internal gas pressure. Automated outflow measurements from mariotte reservoirs are generally difficult because of the reservoir's self-regulation mechanism. This paper describes an automated flow meter specifically designed for use with mariotte reservoirs. The flow meter monitors changes in the mariotte reservoir's gas pressure during outflow to determine changes in the reservoir's water level. The flow measurement is performed by attaching a pressure transducer to the top of a mariotte reservoir and monitoring gas pressure changes during outflow with a programmable data logger. The advantages of the new automated flow measurement techniques include: (i) the ability to rapidly record a large range of fluxes without restricting outflow, and (ii) the ability to accurately average the pulsing flow, which commonly occurs during outflow from the mariotte reservoir.

Rankine cycle condenser pressure control using an energy conversion device bypass valve

DOEpatents

Ernst, Timothy C; Nelson, Christopher R; Zigan, James A

2014-04-01

The disclosure provides a waste heat recovery system and method in which pressure in a Rankine cycle (RC) system of the WHR system is regulated by diverting working fluid from entering an inlet of an energy conversion device of the RC system. In the system, an inlet of a controllable bypass valve is fluidly coupled to a working fluid path upstream of an energy conversion device of the RC system, and an outlet of the bypass valve is fluidly coupled to the working fluid path upstream of the condenser of the RC system such that working fluid passing through the bypass valve bypasses the energy conversion device and increases the pressure in a condenser. A controller determines the temperature and pressure of the working fluid and controls the bypass valve to regulate pressure in the condenser.

Up-regulation of Bcl-2 through hyperbaric pressure transfection of TGF-beta1 ameliorates ischemia-reperfusion injury in rat cardiac allografts.

PubMed

Grünenfelder, Jürg; Miniati, Douglas N; Murata, Seiichiro; Falk, Volkmar; Hoyt, E Grant; Robbins, Robert C

2002-02-01

Oxidative stress after ischemia-reperfusion of cardiac allografts leads to activation of cardiomyocytes and production of cytokines. Bcl-2, an inhibitor of the apoptotic pathway, also has strong antioxidant properties. Ischemia-reperfusion injury after transplantation leads to decreased bcl-2 and increased tumor necrosis factor (TNF)-alpha levels. Transforming growth factor (TGF)-beta1 is known to attenuate ischemia-reperfusion injury and inhibits apoptosis of myofibroblasts. We hypothesize that TGF-beta1, prevents bcl-2 cleavage and increased TNF-alpha production. Rat PVG donor hearts were heterotopically transplanted into ACI recipients. Donor hearts were procured and assigned to groups: (1) intracoronary TGF-beta1 (200 ng/ml) perfusion and pressure at 78 psi for 45 minutes (n = 4); (2) intracoronary TGF-beta1 perfusion and incubation for 45 minutes without pressure (n = 4), (3) saline perfusion and incubation for 45 minutes without pressure (n = 4). Hearts were procured 4 hours after transplantation and analyzed by reverse transcriptase-polymerase chain reaction for bcl-2 mRNA expression, ELISA for TNF-alpha, and for myeloperoxidase activity (MPO). Bcl-2 decreased in untreated animals (bcl-2:G3PDH ratio = 0.85 +/- 0.73 vs 1.16 +/- 0.11, not significant [NS]), whereas TNF-alpha increased to 669.99 +/- 127.09 vs 276.84 +/- 73.65 pg/mg total protein in controls (p < 0.003). In TGF-beta(1) pressure-treated hearts, bcl-2 was up-regulated (2.49 +/- 0.6 vs 1.16 +/- 0.11, controls, p < 0.005), whereas TNF-alpha was unchanged (396.1 +/- 100.38 vs 276.84 +/- 73.65 pg/mg, NS). Hearts treated with TGF-beta1 and pressure showed significant up-regulation of bcl-2 compared with hearts treated with TGF-beta1 without pressure (2.49 +/- 0.6 vs 1.17 +/- 0.6, p < 0.02). MPO showed no differences. Bcl-2 is down-regulated and TNF-alpha up-regulated in this model of ischemia-reperfusion injury. Furthermore, TGF-beta1 is linked to this process and ameliorates reperfusion injury by up-regulating bcl-2 and inhibiting TNF-alpha. Therapeutic overexpression of myocardial TGF-beta1 may be clinically useful to control ischemia-reperfusion injury associated with cardiac transplantation.

How implicit motives and everyday self-regulatory abilities shape cardiovascular risk in youth.

PubMed

Ewart, Craig K; Elder, Gavin J; Smyth, Joshua M

2012-06-01

Tested hypotheses from social action theory that (a) implicit and explicit measures of agonistic (social control) motives and transcendence (self-control) motives differentially predict cardiovascular risk; and (b) implicit motives interact with everyday self-regulation behaviors to magnify risk. Implicit/explicit agonistic/transcendence motives were assessed in a multi-ethnic sample of 64 high school students with the Social Competence Interview (SCI). Everyday self-regulation was assessed with teacher ratings of internalizing, externalizing, and self-control behaviors. Ambulatory blood pressure and daily activities were measured over 48 h. Study hypotheses were supported: implicit goals predicted blood pressure levels but explicit self-reported coping goals did not; self-regulation indices did not predict blood pressure directly but interacted with implicit agonistic/transcendence motives to identify individuals at greatest risk (all p ≤ 0.05). Assessment of implicit motives by SCI, and everyday self-regulation by teachers may improve identification of youth at risk for cardiovascular disease.

49 CFR 173.304b - Additional requirements for shipment of liquefied compressed gases in UN pressure receptacles.

Code of Federal Regulations, 2010 CFR

2010-10-01

... determined as follows: (1) For high pressure liquefied gases, in no case may the filling ratio of the settled... than the vapor pressure of the liquid at 65 °C. (3) For high pressure liquefied gases or gas mixtures... compressed gases in UN pressure receptacles. 173.304b Section 173.304b Transportation Other Regulations...

Neural mechanisms of volume regulation.

PubMed

DiBona, G F

1983-05-01

Under steady-state conditions, urinary sodium excretion matches dietary sodium intake. Because extracellular fluid osmolality is tightly regulated, the quantity of sodium in the extracellular fluid determines the volume of this compartment. The left atrial volume receptor mechanism is an example of a neural mechanism of volume regulation. The left atrial mechanoreceptor, which functions as a sensor in the low-pressure vascular system, has a well-defined compliance relating intravascular volume to filling pressure and responds to changes in wall tension by discharging into afferent vagal fibers. These fibers have appropriate central nervous system representation whose related efferent neurohumoral mechanisms regulate thirst, renal excretion of water and sodium, and the redistribution of the extracellular fluid volume.

Knockout of the Na,K-ATPase α2-isoform in cardiac myocytes delays pressure overload-induced cardiac dysfunction

PubMed Central

Rindler, Tara N.; Lasko, Valerie M.; Nieman, Michelle L.; Okada, Motoi; Lorenz, John N.

2013-01-01

The α2-isoform of the Na,K-ATPase (α2) is the minor isoform of the Na,K-ATPase expressed in the cardiovascular system and is thought to play a critical role in the regulation of cardiovascular hemodynamics. However, the organ system/cell type expressing α2 that is required for this regulation has not been fully defined. The present study uses a heart-specific knockout of α2 to further define the tissue-specific role of α2 in the regulation of cardiovascular hemodynamics. To accomplish this, we developed a mouse model using the Cre/loxP system to generate a tissue-specific knockout of α2 in the heart using β-myosin heavy chain Cre. We have achieved a 90% knockout of α2 expression in the heart of the knockout mice. Interestingly, the heart-specific knockout mice exhibit normal basal cardiac function and systolic blood pressure, and in addition, these mice develop ACTH-induced hypertension in response to ACTH treatment similar to control mice. Surprisingly, the heart-specific knockout mice display delayed onset of cardiac dysfunction compared with control mice in response to pressure overload induced by transverse aortic constriction; however, the heart-specific knockout mice deteriorated to control levels by 9 wk post-transverse aortic constriction. These results suggest that heart expression of α2 does not play a role in the regulation of basal cardiovascular function or blood pressure; however, heart expression of α2 plays a role in the hypertrophic response to pressure overload. This study further emphasizes that the tissue localization of α2 determines its unique roles in the regulation of cardiovascular function. PMID:23436327

Improvement of wound healing by regulated oxygen-enriched negative pressure-assisted wound therapy in a rabbit model.

PubMed

Li, Y Z; Hu, X D; Lai, X M; Li, Y F; Lei, Y

2018-01-01

Development of drug therapies and other techniques for wound care have resulted in significant improvement of the cure rate and shortening of the healing time for wounds. A modified technique of regulated oxygen-enriched negative pressure-assisted wound therapy (RO-NPT) has been reported. To evaluate the efficacy and impact of RO-NPT on wound recovery and inflammation. Infected wounds were established on 40 adult female white rabbits, which were then randomized to one of four groups: O 2 group, regulated negative pressure-assisted wound therapy (RNPT) group, regulated oxygen-enriched negative pressure-assisted wound therapy (RO-NPT) group and healthy control (HC) group. Each day, the O 2 group was treated with a constant oxygen supply (1 L/min) to the wound, while the RNPT group was treated with continuous regulated negative pressure (70 ± 5 mmHg) and the RNPT + O 2 group was treated with both. The HC group was treated with gauze dressing alone, which was changed every day. Leucocyte count, colony count and wound-healing rate were calculated. Levels of tumour necrosis factor (TNF)-α, interleukin (IL)-1β and IL-8 were evaluated by ELISA. RO-RNPT significantly decreased bacterial count and TNF-α level, and increased the wound-healing rate. IL-1β, IL-8 and leucocyte count had a tendency to increase in the early phase of inflammation and a tendency to decrease in the later phase of inflammation in the RO-RNPT group. RO-NPT therapy assisted wound recovery and inflammation control compared with the RNPT and oxygen-enriched therapies. RO-NPT therapy also increased levels of IL-1β and IL-8 and attenuated expression of TNF-α in the early phase of inflammation. © 2017 British Association of Dermatologists.

Water balance in irrigation districts. Uncertainty in on-demand pressurized networks

NASA Astrophysics Data System (ADS)

Sánchez-Calvo, Raúl; Rodríguez-Sinobas, Leonor; Juana, Luis; Laguna, Francisco Vicente

2015-04-01

In on-demand pressurized irrigation distribution networks, applied water volume is usually controlled opening a valve during a calculated time interval, and assuming constant flow rate. In general, pressure regulating devices for controlling the discharged flow rate by irrigation units are needed due to the variability of pressure conditions. A pressure regulating valve PRV is the commonly used pressure regulating device in a hydrant, which, also, executes the open and close function. A hydrant feeds several irrigation units, requiring a wide range in flow rate. In addition, some flow meters are also available, one as a component of the hydrant and the rest are placed downstream. Every land owner has one flow meter for each group of field plots downstream the hydrant. Ideal PRV performance would maintain a constant downstream pressure. However, the true performance depends on both upstream pressure and the discharged flow rate. Theoretical flow rates values have been introduced into a PRV behavioral model, validated in laboratory, coupled with an on-demand irrigation district waterworks, composed by a distribution network and a multi-pump station. Variations on flow rate are simulated by taking into account the consequences of variations on climate conditions and also decisions in irrigation operation, such us duration and frequency application. The model comprises continuity, dynamic and energy equations of the components of both the PRV and the water distribution network. In this work the estimation of water balance terms during the irrigation events in an irrigation campaign has been simulated. The effect of demand concentration peaks has been estimated.

49 CFR 195.303 - Risk-based alternative to pressure testing older hazardous liquid and carbon dioxide pipelines.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Pressure Testing § 195.303 Risk-based alternative to pressure testing older hazardous liquid and carbon... 49 Transportation 3 2014-10-01 2014-10-01 false Risk-based alternative to pressure testing older hazardous liquid and carbon dioxide pipelines. 195.303 Section 195.303 Transportation Other Regulations...

49 CFR 195.303 - Risk-based alternative to pressure testing older hazardous liquid and carbon dioxide pipelines.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Pressure Testing § 195.303 Risk-based alternative to pressure testing older hazardous liquid and carbon... 49 Transportation 3 2013-10-01 2013-10-01 false Risk-based alternative to pressure testing older hazardous liquid and carbon dioxide pipelines. 195.303 Section 195.303 Transportation Other Regulations...

49 CFR 195.303 - Risk-based alternative to pressure testing older hazardous liquid and carbon dioxide pipelines.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Pressure Testing § 195.303 Risk-based alternative to pressure testing older hazardous liquid and carbon... 49 Transportation 3 2012-10-01 2012-10-01 false Risk-based alternative to pressure testing older hazardous liquid and carbon dioxide pipelines. 195.303 Section 195.303 Transportation Other Regulations...

[Pressure control in medical gas distribution systems].

PubMed

Bourgain, J L; Benayoun, L; Baguenard, P; Haré, G; Puizillout, J M; Billard, V

1997-01-01

To assess whether the pressure gauges at the downstream part of pressure regulators are accurate enough to ensure that pressure in O2 pipeline is always higher than in Air pipeline and that pressure in the latter is higher than pressure in N2O pipeline. A pressure difference of at least 0.4 bar between two medical gas supply systems is recommended to avoid the reflow of either N2O or Air into the O2 pipeline, through a faulty mixer or proportioning device. Prospective technical comparative study. Readings of 32 Bourdon gauges were compared with data obtained with a calibrated reference transducer. Two sets of measurements were performed at a one month interval. Pressure differences between Bourdon gauges and reference transducer were 8% (0.28 bar) in average for a theoretical maximal error less than 2.5%. During the first set of measurements, Air pressure was higher than O2 pressure in one place and N2O pressure higher than Air pressure in another. After an increase in the O2 pipeline pressure and careful setting of pressure regulators, this problem was not observed at the second set of measurements. Actual accuracy of Bourdon gauges was not convenient enough to ensure that O2 pressure was always above Air pressure. Regular controls of these pressure gauges are therefore essential. Replacement of the faulty Bourdon gauges by more accurate transducers should be considered. As an alternative, the increase in pressure difference between O2 and Air pipelines to at least 0.6 bar is recommended.

Nitric oxide (NO) in normal and hypoxic vascular regulation of the spiny dogfish, Squalus acanthias.

PubMed

Swenson, Kai E; Eveland, Randy L; Gladwin, Mark T; Swenson, Erik R

2005-02-01

Nitric oxide (NO) is a potent vasodilator in terrestrial vertebrates, but whether vascular endothelial-derived NO plays a role in vascular regulation in fish remains controversial. To explore this issue, a study was made of spiny dogfish sharks (Squalus acanthias) in normoxia and acute hypoxia (60 min exposure to seawater equilibrated with 3% oxygen) with various agents known to alter NO metabolism or availability. In normoxia, nitroprusside (a NO donor) reduced blood pressure by 20%, establishing that vascular smooth muscle responds to NO. L-arginine, the substrate for NO synthase, had no hemodynamic effect. Acetylcholine, which stimulates endothelial NO and prostaglandin production in mammals, reduced blood pressure, but also caused marked bradycardia. L-NAME, an inhibitor of all NO synthases, caused a small 10% rise in blood pressure, but cell-free hemoglobin (a potent NO scavenger and hypertensive agent in mammals) had no effect. Acute hypoxia caused a 15% fall in blood pressure, which was blocked by L-NAME and cell-free hemoglobin. Serum nitrite, a marker of NO production, rose with hypoxia, but not with L-NAME. Results suggest that NO is not an endothelial-derived vasodilator in the normoxic elasmobranch. The hypertensive effect of L-NAME may represent inhibition of NO production in the CNS and nerves regulating blood pressure. In acute hypoxia, there is a rapid up-regulation of vascular NO production that appears to be responsible for hypoxic vasodilation.

49 CFR 192.359 - Customer meter installations: Operating pressure.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 3 2010-10-01 2010-10-01 false Customer meter installations: Operating pressure... SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Customer Meters, Service Regulators, and Service Lines § 192.359 Customer meter installations: Operating pressure...

Music improves dopaminergic neurotransmission: demonstration based on the effect of music on blood pressure regulation.

PubMed

Sutoo, Den'etsu; Akiyama, Kayo

2004-08-06

The mechanism by which music modifies brain function is not clear. Clinical findings indicate that music reduces blood pressure in various patients. We investigated the effect of music on blood pressure in spontaneously hypertensive rats (SHR). Previous studies indicated that calcium increases brain dopamine (DA) synthesis through a calmodulin (CaM)-dependent system. Increased DA levels reduce blood pressure in SHR. In this study, we examined the effects of music on this pathway. Systolic blood pressure in SHR was reduced by exposure to Mozart's music (K.205), and the effect vanished when this pathway was inhibited. Exposure to music also significantly increased serum calcium levels and neostriatal DA levels. These results suggest that music leads to increased calcium/CaM-dependent DA synthesis in the brain, thus causing a reduction in blood pressure. Music might regulate and/or affect various brain functions through dopaminergic neurotransmission, and might therefore be effective for rectification of symptoms in various diseases that involve DA dysfunction.

Time pressure and regulations on hospital-in-the-home (HITH) nurses: An on-the-road study.

PubMed

Cœugnet, Stéphanie; Forrierre, Justine; Naveteur, Janick; Dubreucq, Catherine; Anceaux, Françoise

2016-05-01

This study investigated both causal factors and consequences of time pressure in hospital-in-the-home (HITH) nurses. These nurses may experience additional stress from the time pressure they encounter while driving to patients' homes, which may result in greater risk taking while driving. From observation in natural settings, data related to the nurses' driving behaviours and emotions were collected and analysed statistically; semi-directed interviews with the nurses were analysed qualitatively. The results suggest that objective time constraints alone do not necessarily elicit subjective time pressure. The challenges and uncertainty associated with healthcare and the driving period contribute to the emergence of this time pressure, which has a negative impact on both the nurses' driving and their emotions. Finally, the study focuses on anticipated and in situ regulations. These findings provide guidelines for organizational and technical solutions allowing the reduction of time pressure among HITH nurses. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Cardiopulmonary Laboratory AFSC 904X0

DTIC Science & Technology

1990-10-01

SET UP POSITIVE END EXPIRATORY PRESSURE (PEEP) DEVICES 100 J321 SET UP CONTINUOUS POSITIVE AIRWAY PRESSURE ( CPAP ) DEVICES 100 J298 ASSIST PHYSICIAN IN...PRESSURE VENTILATORS 61 COMPUTERIZED PULMONARY FUNCTION ANALYZERS 61 TREADMILLS 59 HOLTER MONITOR EQUIPMENT 57 CPAP EQUIPMENT 54 PRESSURE REGULATORS 48...SUCTIONING PROCEDURES 95 J321 SET UP CONTINUOUS POSITIVE AIRWAY PRESSURE ( CPAP ) DEVICES 95 J332 SET UP VOLUME VENTILATORS 93 F148 PERFORM ARTERIAL PUNCTURES 93

Improved wound management by regulated negative pressure-assisted wound therapy and regulated, oxygen- enriched negative pressure-assisted wound therapy through basic science research and clinical assessment.

PubMed

Topaz, Moris

2012-05-01

Regulated negative pressure-assisted wound therapy (RNPT) should be regarded as a state-of-the-art technology in wound treatment and the most important physical, nonpharmaceutical, platform technology developed and applied for wound healing in the last two decades. RNPT systems maintain the treated wound's environment as a semi-closed, semi-isolated system applying external physical stimulations to the wound, leading to biological and biochemical effects, with the potential to substantially influence wound-host interactions, and when properly applied may enhance wound healing. RNPT is a simple, safe, and affordable tool that can be utilized in a wide range of acute and chronic conditions, with reduced need for complicated surgical procedures, and antibiotic treatment. This technology has been shown to be effective and safe, saving limbs and lives on a global scale. Regulated, oxygen-enriched negative pressure-assisted wound therapy (RO-NPT) is an innovative technology, whereby supplemental oxygen is concurrently administered with RNPT for their synergistic effect on treatment and prophylaxis of anaerobic wound infection and promotion of wound healing. Understanding the basic science, modes of operation and the associated risks of these technologies through their fundamental clinical mechanisms is the main objective of this review.

[Participation of nitric oxide and arachidonic acid metabolites via cytochrome - P450 in the regulation of arterial blood pressure].

PubMed

Sánchez-Mendoza, M Alicia; Martínez-Ayala, Sonia O; Hernández-Hernández, José A; Zúñiga-Sosa, Leonor; Pastelín-Hernández, Gustavo; Escalante-Acosta, Bruno A

2003-01-01

Nitric oxide and cytochrome P450 arachidonic acid metabolites participate in blood pressure regulation. The synthesis of these autacoids leads to arterial hypertension. However, it is not known whether there is an interaction between them. Therefore, we studied the modulatory effect of nitric oxide and cytochrome P450-arachidonic acid metabolites, their interaction on blood pressure, and the renal content of cytochrome P450. Male Wistar rats were divided: 1) control, 2) L-NAME (100 mg/kg/d p.o.), 3) L-NAME + SnCl2 (10 mg/kg/d i.p.), and 4) L-NAME + dexamethasone (1 mg/kg/d s.c.). We measured blood pressure and collected urine and blood for nitric oxide measurement. NO2 was quantified by HPLC. Blood pressure was: control, 97 +/- 7 mmHg; L-NAME, 151 +/- 4.6 mmHg; L-NAME + SnCl2, 133 +/- 3 mmHg, and L-NAME + dexamethasone 152 +/- 4.5 mmHg. Urine nitrite concentration was: 1) 1.832 +/- 0.32, 2) 1.031 +/- 0.23, 3) 1.616 +/- 0.33, and 4) 1.244 +/- 0.33 mumol/mL, while the concentration in blood was: 1) 0.293 +/- 0.06, 2) 0.150 +/- 0.05, 3) 0.373 +/- 0.13, and 4) 0.373 +/- 0.07 mumol/mL. L-NAME + SnCl2 decreased cytochrome P450 renal content, and L-NAME + dexamethasone showed a similar response. In conclusion, both, nitric oxide and CYP-arachidonic acid metabolites play a role in the regulation of blood pressure. Nitric oxide also partially regulates renal cytochrome P450 content.

Chronic Blockade of Brain Endothelin Receptor Type-A (ETA) Reduces Blood Pressure and Prevents Catecholaminergic Overactivity in the Right Olfactory Bulb of DOCA-Salt Hypertensive Rats.

PubMed

Cassinotti, Luis R; Guil, María J; Schöller, Mercedes I; Navarro, Mónica P; Bianciotti, Liliana G; Vatta, Marcelo S

2018-02-27

Overactivity of the sympathetic nervous system and central endothelins (ETs) are involved in the development of hypertension. Besides the well-known brain structures involved in the regulation of blood pressure like the hypothalamus or locus coeruleus, evidence suggests that the olfactory bulb (OB) also modulates cardiovascular function. In the present study, we evaluated the interaction between the endothelinergic and catecholaminergic systems in the OB of deoxycorticosterone acetate (DOCA)-salt hypertensive rats. Following brain ET receptor type A (ET A ) blockade by BQ610 (selective antagonist), transcriptional, traductional, and post-traductional changes in tyrosine hydroxylase (TH) were assessed in the OB of normotensive and DOCA-salt hypertensive rats. Time course variations in systolic blood pressure and heart rate were also registered. Results showed that ET A blockade dose dependently reduced blood pressure in hypertensive rats, but it did not change heart rate. It also prevented the increase in TH activity and expression (mRNA and protein) in the right OB of hypertensive animals. However, ET A blockade did not affect hemodynamics or TH in normotensive animals. Present results support that brain ET A are not involved in blood pressure regulation in normal rats, but they significantly contribute to chronic blood pressure elevation in hypertensive animals. Changes in TH activity and expression were observed in the right but not in the left OB, supporting functional asymmetry, in line with previous studies regarding cardiovascular regulation. Present findings provide further evidence on the role of ETs in the regulation of catecholaminergic activity and the contribution of the right OB to DOCA-salt hypertension.

Regulation of Blood Pressure and Salt Homeostasis by Endothelin

PubMed Central

KOHAN, DONALD E.; ROSSI, NOREEN F.; INSCHO, EDWARD W.; POLLOCK, DAVID M.

2011-01-01

Endothelin (ET) peptides and their receptors are intimately involved in the physiological control of systemic blood pressure and body Na homeostasis, exerting these effects through alterations in a host of circulating and local factors. Hormonal systems affected by ET include natriuretic peptides, aldosterone, catecholamines, and angiotensin. ET also directly regulates cardiac output, central and peripheral nervous system activity, renal Na and water excretion, systemic vascular resistance, and venous capacitance. ET regulation of these systems is often complex, sometimes involving opposing actions depending on which receptor isoform is activated, which cells are affected, and what other prevailing factors exist. A detailed understanding of this system is important; disordered regulation of the ET system is strongly associated with hypertension and dysregulated extracellular fluid volume homeostasis. In addition, ET receptor antagonists are being increasingly used for the treatment of a variety of diseases; while demonstrating benefit, these agents also have adverse effects on fluid retention that may substantially limit their clinical utility. This review provides a detailed analysis of how the ET system is involved in the control of blood pressure and Na homeostasis, focusing primarily on physiological regulation with some discussion of the role of the ET system in hypertension. PMID:21248162

Cystic Fibrosis Transmembrane Conductance Regulator Potentiation as a Therapeutic Strategy for Pulmonary Edema: A Proof-of-Concept Study in Pigs.

PubMed

Li, Xiaopeng; Vargas Buonfiglio, Luis G; Adam, Ryan J; Stoltz, David A; Zabner, Joseph; Comellas, Alejandro P

2017-12-01

To determine the feasibility of using a cystic fibrosis transmembrane conductance regulator potentiator, ivacaftor (VX-770/Kalydeco, Vertex Pharmaceuticals, Boston, MA), as a therapeutic strategy for treating pulmonary edema. Prospective laboratory animal investigation. Animal research laboratory. Newborn and 3 days to 1 week old pigs. Hydrostatic pulmonary edema was induced in pigs by acute volume overload. Ivacaftor was nebulized into the lung immediately after volume overload. Grams of water per grams of dry lung tissue were determined in the lungs harvested 1 hour after volume overload. Ivacaftor significantly improved alveolar liquid clearance in isolated pig lung lobes ex vivo and reduced edema in a volume overload in vivo pig model of hydrostatic pulmonary edema. To model hydrostatic pressure-induced edema in vitro, we developed a method of applied pressure to the basolateral surface of alveolar epithelia. Elevated hydrostatic pressure resulted in decreased cystic fibrosis transmembrane conductance regulator activity and liquid absorption, an effect which was partially reversed by cystic fibrosis transmembrane conductance regulator potentiation with ivacaftor. Cystic fibrosis transmembrane conductance regulator potentiation by ivacaftor is a novel therapeutic approach for pulmonary edema.

49 CFR 179.101 - Individual specification requirements applicable to pressure tank car tanks.

Code of Federal Regulations, 2014 CFR

2014-10-01

... to pressure tank car tanks. 179.101 Section 179.101 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109...

49 CFR 179.100 - General specifications applicable to pressure tank car tanks.

Code of Federal Regulations, 2012 CFR

2012-10-01

... car tanks. 179.100 Section 179.100 Transportation Other Regulations Relating to Transportation...) SPECIFICATIONS FOR TANK CARS Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.100 General specifications applicable to pressure tank car tanks. ...

49 CFR 179.100 - General specifications applicable to pressure tank car tanks.

Code of Federal Regulations, 2013 CFR

2013-10-01

... car tanks. 179.100 Section 179.100 Transportation Other Regulations Relating to Transportation...) SPECIFICATIONS FOR TANK CARS Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.100 General specifications applicable to pressure tank car tanks. ...

49 CFR 179.100 - General specifications applicable to pressure tank car tanks.

Code of Federal Regulations, 2011 CFR

2011-10-01

... car tanks. 179.100 Section 179.100 Transportation Other Regulations Relating to Transportation...) SPECIFICATIONS FOR TANK CARS Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.100 General specifications applicable to pressure tank car tanks. ...

Air Pressure Responses to Sudden Vocal Tract Pressure Bleeds during Production of Stop Consonants: New Evidence of Aeromechanical Regulation.

ERIC Educational Resources Information Center

Zajac, David J.; Weissler, Mark C.

2004-01-01

Two studies were conducted to evaluate short-latency vocal tract air pressure responses to sudden pressure bleeds during production of voiceless bilabial stop consonants. It was hypothesized that the occurrence of respiratory reflexes would be indicated by distinct patterns of responses as a function of bleed magnitude. In Study 1, 19 adults…

46 CFR 30.10-55 - Pressure vacuum relief valve-TB/ALL.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 1 2011-10-01 2011-10-01 false Pressure vacuum relief valve-TB/ALL. 30.10-55 Section 30... Definitions § 30.10-55 Pressure vacuum relief valve—TB/ALL. The term pressure vacuum relief valve means any device or assembly of a mechanical, liquid, weight, or other type used for the automatic regulation of...

46 CFR 30.10-55 - Pressure vacuum relief valve-TB/ALL.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 1 2014-10-01 2014-10-01 false Pressure vacuum relief valve-TB/ALL. 30.10-55 Section 30... Definitions § 30.10-55 Pressure vacuum relief valve—TB/ALL. The term pressure vacuum relief valve means any device or assembly of a mechanical, liquid, weight, or other type used for the automatic regulation of...

46 CFR 30.10-55 - Pressure vacuum relief valve-TB/ALL.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Pressure vacuum relief valve-TB/ALL. 30.10-55 Section 30... Definitions § 30.10-55 Pressure vacuum relief valve—TB/ALL. The term pressure vacuum relief valve means any device or assembly of a mechanical, liquid, weight, or other type used for the automatic regulation of...

46 CFR 30.10-55 - Pressure vacuum relief valve-TB/ALL.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 1 2012-10-01 2012-10-01 false Pressure vacuum relief valve-TB/ALL. 30.10-55 Section 30... Definitions § 30.10-55 Pressure vacuum relief valve—TB/ALL. The term pressure vacuum relief valve means any device or assembly of a mechanical, liquid, weight, or other type used for the automatic regulation of...

46 CFR 30.10-55 - Pressure vacuum relief valve-TB/ALL.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 1 2013-10-01 2013-10-01 false Pressure vacuum relief valve-TB/ALL. 30.10-55 Section 30... Definitions § 30.10-55 Pressure vacuum relief valve—TB/ALL. The term pressure vacuum relief valve means any device or assembly of a mechanical, liquid, weight, or other type used for the automatic regulation of...

Vestibular activation of sympathetic nerve activity

NASA Technical Reports Server (NTRS)

Ray, C. A.; Carter, J. R.

2003-01-01

AIM: The vestibulosympathetic reflex refers to sympathetic nerve activation by the vestibular system. Animal studies indicate that the vestibular system assists in blood pressure regulation during orthostasis. Although human studies clearly demonstrate activation of muscle sympathetic nerve activity (MSNA) during engagement of the otolith organs, the role of the vestibulosympathetic reflex in maintaining blood pressure during orthostasis is not well-established. Examination of the vestibulosympathetic reflex with other cardiovascular reflexes indicates that it is a powerful and independent reflex. Ageing, which is associated with an increased risk for orthostatic hypotension, attenuates the vestibulosympathetic reflex. The attenuated reflex is associated with a reduction in arterial pressure. CONCLUSION: These findings suggest that the vestibulosympathetic reflex assists in blood pressure regulation in humans, but future studies examining this reflex in other orthostatically intolerant populations are necessary to address this hypothesis.

Combined pressure regulator and shutoff valve

NASA Technical Reports Server (NTRS)

Koch, E. F. (Inventor)

1974-01-01

A remotely operable pressure regulator and shutoff valve particularly suited for achieving high resolution and flow control, and positive shutoff is described. The valve is characterized by a spring-loaded ball coaxially aligned with a fluid port to be sealed, a spring-loaded pintle extended through the port into engagement with the ball, for controlling the position, a spring-loaded diaphragm for controlling the position of the pintle, and an axially displaceable spring supported by a movable stop which, in turn, is repositioned by a selectively operable stepper motor. Thus, the pressure-response characteristics for the valve can be varied through a selective repositioning of the stop.

Analyzing threshold pressure limitations in microfluidic transistors for self-regulated microfluidic circuits.

PubMed

Kim, Sung-Jin; Yokokawa, Ryuji; Takayama, Shuichi

2012-12-03

This paper reveals a critical limitation in the electro-hydraulic analogy between a microfluidic membrane-valve (μMV) and an electronic transistor. Unlike typical transistors that have similar on and off threshold voltages, in hydraulic μMVs, the threshold pressures for opening and closing are significantly different and can change, even for the same μMVs depending on overall circuit design and operation conditions. We explain, in particular, how the negative values of the closing threshold pressures significantly constrain operation of even simple hydraulic μMV circuits such as autonomously switching two-valve microfluidic oscillators. These understandings have significant implications in designing self-regulated microfluidic devices.

Role of the medulla oblongata in normal and high arterial blood pressure regulation: the contribution of Escola Paulista de Medicina - UNIFESP.

PubMed

Cravo, Sergio L; Campos, Ruy R; Colombari, Eduardo; Sato, Mônica A; Bergamaschi, Cássia M; Pedrino, Gustavo R; Ferreira-Neto, Marcos L; Lopes, Oswaldo U

2009-09-01

Several forms of experimental evidence gathered in the last 37 years have unequivocally established that the medulla oblongata harbors the main neural circuits responsible for generating the vasomotor tone and regulating arterial blood pressure. Our current understanding of this circuitry derives mainly from the studies of Pedro Guertzenstein, a former student who became Professor of Physiology at UNIFESP later, and his colleagues. In this review, we have summarized the main findings as well as our collaboration to a further understanding of the ventrolateral medulla and the control of arterial blood pressure under normal and pathological conditions.

Small-molecule WNK inhibition regulates cardiovascular and renal function

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yamada, Ken; Park, Hyi-Man; Rigel, Dean F.

The With-No-Lysine (K) (WNK) kinases play a critical role in blood pressure regulation and body fluid and electrolyte homeostasis. Herein, we introduce the first orally bioavailable pan-WNK-kinase inhibitor, WNK463, that exploits unique structural features of the WNK kinases for both affinity and kinase selectivity. In rodent models of hypertension, WNK463 affects blood pressure and body fluid and electro-lyte homeostasis, consistent with WNK-kinase-associated physiology and pathophysiology.

49 CFR 179.201 - Individual specification requirements applicable to non-pressure tank car tanks.

Code of Federal Regulations, 2014 CFR

2014-10-01

... to non-pressure tank car tanks. 179.201 Section 179.201 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW...

49 CFR 192.181 - Distribution line valves.

Code of Federal Regulations, 2010 CFR

2010-10-01

... line valves. (a) Each high-pressure distribution system must have valves spaced so as to reduce the... pressure, the size of the mains, and the local physical conditions. (b) Each regulator station controlling the flow or pressure of gas in a distribution system must have a valve installed on the inlet piping...

49 CFR 192.619 - Maximum allowable operating pressure: Steel or plastic pipelines.

Code of Federal Regulations, 2010 CFR

2010-10-01

... plastic pipelines. 192.619 Section 192.619 Transportation Other Regulations Relating to Transportation... Operations § 192.619 Maximum allowable operating pressure: Steel or plastic pipelines. (a) No person may operate a segment of steel or plastic pipeline at a pressure that exceeds a maximum allowable operating...

16 CFR 1500.46 - Method for determining flashpoint of extremely flammable contents of self-pressurized containers.

Code of Federal Regulations, 2010 CFR

2010-01-01

... extremely flammable contents of self-pressurized containers. 1500.46 Section 1500.46 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS HAZARDOUS SUBSTANCES AND... extremely flammable contents of self-pressurized containers. Use the apparatus described in § 1500.43a. Use...

Pressure Safety Program Implementation at ORNL

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lower, Mark; Etheridge, Tom; Oland, C. Barry

2013-01-01

The Oak Ridge National Laboratory (ORNL) is a US Department of Energy (DOE) facility that is managed by UT-Battelle, LLC. In February 2006, DOE promulgated worker safety and health regulations to govern contractor activities at DOE sites. These regulations, which are provided in 10 CFR 851, Worker Safety and Health Program, establish requirements for worker safety and health program that reduce or prevent occupational injuries, illnesses, and accidental losses by providing DOE contractors and their workers with safe and healthful workplaces at DOE sites. The regulations state that contractors must achieve compliance no later than May 25, 2007. According tomore » 10 CFR 851, Subpart C, Specific Program Requirements, contractors must have a structured approach to their worker safety and health programs that at a minimum includes provisions for pressure safety. In implementing the structured approach for pressure safety, contractors must establish safety policies and procedures to ensure that pressure systems are designed, fabricated, tested, inspected, maintained, repaired, and operated by trained, qualified personnel in accordance with applicable sound engineering principles. In addition, contractors must ensure that all pressure vessels, boilers, air receivers, and supporting piping systems conform to (1) applicable American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (2004) Sections I through XII, including applicable code cases; (2) applicable ASME B31 piping codes; and (3) the strictest applicable state and local codes. When national consensus codes are not applicable because of pressure range, vessel geometry, use of special materials, etc., contractors must implement measures to provide equivalent protection and ensure a level of safety greater than or equal to the level of protection afforded by the ASME or applicable state or local codes. This report documents the work performed to address legacy pressure vessel deficiencies and comply with pressure safety requirements in 10 CFR 851. It also describes actions taken to develop and implement ORNL’s Pressure Safety Program.« less

Irrigation Sprinklers Notice of Intent

EPA Pesticide Factsheets

High-efficiency irrigation sprinklers aim to deliver water more evenly to the landscape than traditional sprinklers and/or regulate outlet pressure to ensure a constant flow rate over a range of supply pressures.

Feedback Regulation of Intracellular Hydrostatic Pressure in Surface Cells of the Lens

PubMed Central

Gao, Junyuan; Sun, Xiurong; White, Thomas W.; Delamere, Nicholas A.; Mathias, Richard T.

2015-01-01

In wild-type lenses from various species, an intracellular hydrostatic pressure gradient goes from ∼340 mmHg in central fiber cells to 0 mmHg in surface cells. This gradient drives a center-to-surface flow of intracellular fluid. In lenses in which gap-junction coupling is increased, the central pressure is lower, whereas if gap-junction coupling is reduced, the central pressure is higher but surface pressure is always zero. Recently, we found that surface cell pressure was elevated in PTEN null lenses. This suggested disruption of a feedback control system that normally maintained zero surface cell pressure. Our purpose in this study was to investigate and characterize this feedback control system. We measured intracellular hydrostatic pressures in mouse lenses using a microelectrode/manometer-based system. We found that all feedback went through transport by the Na/K ATPase, which adjusted surface cell osmolarity such that pressure was maintained at zero. We traced the regulation of Na/K ATPase activity back to either TRPV4, which sensed positive pressure and stimulated activity, or TRPV1, which sensed negative pressure and inhibited activity. The inhibitory effect of TRPV1 on Na/K pumps was shown to signal through activation of the PI3K/AKT axis. The stimulatory effect of TRPV4 was shown in previous studies to go through a different signal transduction path. Thus, there is a local two-legged feedback control system for pressure in lens surface cells. The surface pressure provides a pedestal on which the pressure gradient sits, so surface pressure determines the absolute value of pressure at each radial location. We speculate that the absolute value of intracellular pressure may set the radial gradient in the refractive index, which is essential for visual acuity. PMID:26536260

Circulating Blood eNOS Contributes to the Regulation of Systemic Blood Pressure and Nitrite Homeostasis

PubMed Central

Wood, Katherine C.; Cortese-Krott, Miriam M.; Kovacic, Jason C.; Noguchi, Audrey; Liu, Virginia B.; Wang, Xunde; Raghavachari, Nalini; Boehm, Manfred; Kato, Gregory J.; Kelm, Malte; Gladwin, Mark T.

2013-01-01

Objective Mice genetically deficient in endothelial nitric oxide synthase (eNOS−/−) are hypertensive with lower circulating nitrite levels, indicating the importance of constitutively produced nitric oxide (NO•) to blood pressure regulation and vascular homeostasis. While the current paradigm holds that this bioactivity derives specifically from expression of eNOS in endothelium, circulating blood cells also express eNOS protein. A functional red cell eNOS that modulates vascular NO• signaling has been proposed. Approach and Results To test the hypothesis that blood cells contribute to mammalian blood pressure regulation via eNOS-dependent NO• generation, we cross-transplanted WT and eNOS−/− mice, producing chimeras competent or deficient for eNOS expression in circulating blood cells. Surprisingly, we observed a significant contribution of both endothelial and circulating blood cell eNOS to blood pressure and systemic nitrite levels, the latter being a major component of the circulating NO• reservoir. These effects were abolished by the NOS inhibitor L-NAME and repristinated by the NOS substrate L-Arginine, and were independent of platelet or leukocyte depletion. Mouse erythrocytes were also found to carry an eNOS protein and convert 14C-Arginine into 14C-Citrulline in a NOS-dependent fashion. Conclusions These are the first studies to definitively establish a role for a blood borne eNOS, using cross transplant chimera models, that contributes to the regulation of blood pressure and nitrite homeostasis. This work provides evidence suggesting that erythrocyte eNOS may mediate this effect. PMID:23702660

Neurohumoral Mechanisms Associated with Orthostasis: Reaffirmation of the Significant Contribution of the Heart Rate Response

DTIC Science & Technology

2014-06-30

baroreceptor stimu- lation (i.e., lower arterial blood pressure ) suggests an association between a depressed baroreflex response and development of...orthostatic tolerance, blood pressure regulation, lower body negative pressure , parasympathetic activity, sympathetic activity, propranolol, atropine...body negative pressure (LBNP) so that comparisons of physiology in individuals with high and low tolerance to central hypovolemia could be studied at

The Role of Neural Reflexes in Control of the Cardiovascular System during Stress.

DTIC Science & Technology

1984-02-01

cold block increase arterial pressure but did not alter plasma renin activity or renin secretory rate in dogs with normal or high sodium diet...also found that these afferents may play a keen role in the regulation of renin scretoary rate during conditions which may alter cardiopulmonary blood ...important hormone in -. the regulation of arterial pressure . However, the role of the nervous system in controlling the release of vasopressin has not been

Unmanned Evaluation of Mares Abyss 22 Navy Open Circuit Scuba Regulator for Cold Water Diving

DTIC Science & Technology

2011-05-05

regulator is shown above the water. Note the blue mouthpiece adaptor, white oral static pressure pick-up ring , and gray routing block attached for...e.g., an inflation whip or a second-stage octopus ), submersible pressure gage, or gas-integrated computer were connected to the first stage. As...adaptor (shown in blue ) inward into the second-stage assembly, Figure 9 indicates typical 9 internal second-stage icing experienced during Phase

Gasoline Reid Vapor Pressure

EPA Pesticide Factsheets

EPA regulates the vapor pressure of gasoline sold at retail stations during the summer ozone season to reduce evaporative emissions from gasoline that contribute to ground-level ozone and diminish the effects of ozone-related health problems.

Intraocular pressure reduction and regulation

NASA Technical Reports Server (NTRS)

Baehr, E. F.; Mcgannon, W. J.

1979-01-01

System designed to reduce intraocular pressure hydraulically to any level desired by physician over set time and in controlled manner has number of uses in ophthalmology. Device may be most immediately useful in treatment of glaucoma.

49 CFR 179.200-23 - Tests of pressure relief valves.

Code of Federal Regulations, 2010 CFR

2010-10-01

... MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS SPECIFICATIONS FOR TANK CARS Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.200...

An Inquiry-Based Teaching Tool for Understanding Arterial Blood Pressure Regulation and Cardiovascular Function.

ERIC Educational Resources Information Center

Collins, Heidi L.; Rodenbaugh, David W.; Murphy, Todd P.; Kulics, Jennifer M.; Bailey, Cynthia M.; DiCarlo, Stephen E.

1999-01-01

Presents a laboratory exercise designed to introduce students to the hemodynamic variables (heart rate, stroke volume, total peripheral resistance, and compliance) that alter arterial pressure. (Author/CCM)

Blood pressure regulation V: in vivo mechanical properties of precapillary vessels as affected by long-term pressure loading and unloading.

PubMed

Eiken, Ola; Mekjavic, Igor B; Kölegård, Roger

2014-03-01

Recent studies are reviewed, concerning the in vivo wall stiffness of arteries and arterioles in healthy humans, and how these properties adapt to iterative increments or sustained reductions in local intravascular pressure. A novel technique was used, by which arterial and arteriolar stiffness was determined as changes in arterial diameter and flow, respectively, during graded increments in distending pressure in the blood vessels of an arm or a leg. Pressure-induced increases in diameter and flow were smaller in the lower leg than in the arm, indicating greater stiffness in the arteries/arterioles of the leg. A 5-week period of intermittent intravascular pressure elevations in one arm reduced pressure distension and pressure-induced flow in the brachial artery by about 50%. Conversely, prolonged reduction of arterial/arteriolar pressure in the lower body by 5 weeks of sustained horizontal bedrest, induced threefold increases of the pressure-distension and pressure-flow responses in a tibial artery. Thus, the wall stiffness of arteries and arterioles are plastic properties that readily adapt to changes in the prevailing local intravascular pressure. The discussion concerns mechanisms underlying changes in local arterial/arteriolar stiffness as well as whether stiffness is altered by changes in myogenic tone and/or wall structure. As regards implications, regulation of local arterial/arteriolar stiffness may facilitate control of arterial pressure in erect posture and conditions of exaggerated intravascular pressure gradients. That increased intravascular pressure leads to increased arteriolar wall stiffness also supports the notion that local pressure loading may constitute a prime mover in the development of vascular changes in hypertension.

Simulation of a Cold Gas Thruster System and Test Data Correlation

NASA Technical Reports Server (NTRS)

Hauser, Daniel M.; Quinn, Frank D.

2012-01-01

During developmental testing of the Ascent Abort 1 (AA-1) cold gas thruster system, unexpected behavior was detected. Upon further review the design as it existed may not have met the requirements. To determine the best approach for modifying the design, the system was modeled with a dynamic fluid analysis tool (EASY5). The system model consisted of the nitrogen storage tank, pressure regulator, thruster valve, nozzle, and the associated interconnecting line lengths. The regulator and thruster valves were modeled using a combination of the fluid and mechanical modules available in EASY5. The simulation results were then compared against actual system test data. The simulation results exhibited behaviors similar to the test results, such as the pressure regulators response to thruster firings. Potential design solutions were investigated using the analytical model parameters, including increasing the volume downstream of the regulator and increasing the orifice area. Both were shown to improve the regulator response.

49 CFR Appendix D to Part 227 - Audiometric Test Rooms

Code of Federal Regulations, 2011 CFR

2011-10-01

... sound pressure levels exceeding those in Table D-1 when measured by equipment conforming at least to the..._regulations/ibr_locations.html. Table D-1—Maximum Allowable Octave-Band Sound Pressure Levels for Audiometric Test Rooms Octave-band center frequency (Hz) 500 1000 2000 4000 8000 Sound pressure levels—supra-aural...

49 CFR Appendix D to Part 227 - Audiometric Test Rooms

Code of Federal Regulations, 2010 CFR

2010-10-01

... sound pressure levels exceeding those in Table D-1 when measured by equipment conforming at least to the..._regulations/ibr_locations.html. Table D-1—Maximum Allowable Octave-Band Sound Pressure Levels for Audiometric Test Rooms Octave-band center frequency (Hz) 500 1000 2000 4000 8000 Sound pressure levels—supra-aural...

49 CFR 179.102 - Special commodity requirements for pressure tank car tanks.

Code of Federal Regulations, 2013 CFR

2013-10-01

... car tanks. 179.102 Section 179.102 Transportation Other Regulations Relating to Transportation...) SPECIFICATIONS FOR TANK CARS Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.102 Special commodity requirements for pressure tank car tanks. (a) In addition to §§ 179.100 and...

49 CFR 179.102 - Special commodity requirements for pressure tank car tanks.

Code of Federal Regulations, 2012 CFR

2012-10-01

... car tanks. 179.102 Section 179.102 Transportation Other Regulations Relating to Transportation...) SPECIFICATIONS FOR TANK CARS Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.102 Special commodity requirements for pressure tank car tanks. (a) In addition to §§ 179.100 and...

49 CFR 179.102 - Special commodity requirements for pressure tank car tanks.

Code of Federal Regulations, 2011 CFR

2011-10-01

... car tanks. 179.102 Section 179.102 Transportation Other Regulations Relating to Transportation...) SPECIFICATIONS FOR TANK CARS Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.102 Special commodity requirements for pressure tank car tanks. (a) In addition to §§ 179.100 and...

30 CFR 250.616 - Blowout preventer system testing, records, and drills.

Code of Federal Regulations, 2011 CFR

2011-07-01

... drills. 250.616 Section 250.616 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION, AND... drills. (a) BOP pressure tests. When you pressure test the BOP system you must conduct a low-pressure... engaged in well-workover operations shall participate in a weekly BOP drill to familiarize crew members...

49 CFR 393.51 - Warning signals, air pressure and vacuum gauges.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 5 2011-10-01 2011-10-01 false Warning signals, air pressure and vacuum gauges... REGULATIONS PARTS AND ACCESSORIES NECESSARY FOR SAFE OPERATION Brakes § 393.51 Warning signals, air pressure... paragraphs (b), (c), (d) or (e) of this section. (b) Hydraulic brakes. Vehicles manufactured on or after...

49 CFR 393.51 - Warning signals, air pressure and vacuum gauges.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 5 2014-10-01 2014-10-01 false Warning signals, air pressure and vacuum gauges... REGULATIONS PARTS AND ACCESSORIES NECESSARY FOR SAFE OPERATION Brakes § 393.51 Warning signals, air pressure... paragraphs (b), (c), (d) or (e) of this section. (b) Hydraulic brakes. Vehicles manufactured on or after...

29 CFR 1915.172 - Portable air receivers and other unfired pressure vessels.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 29 Labor 7 2011-07-01 2011-07-01 false Portable air receivers and other unfired pressure vessels. 1915.172 Section 1915.172 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) OCCUPATIONAL SAFETY AND HEALTH STANDARDS FOR SHIPYARD EMPLOYMENT Portable, Unfired Pressure...

46 CFR 38.05-25 - Refrigerated systems-TB/ALL.

Code of Federal Regulations, 2010 CFR

2010-10-01

... atmospheric temperature under the requirements of § 38.05-3(f) or § 38.05-4, maintenance of the tank pressure below the maximum allowable pressure shall be provided by one or more of the following means: (1) A refrigeration or liquefication system which regulates the pressure in the tanks. A standby compressor or...

Robust linear parameter-varying control of blood pressure using vasoactive drugs

NASA Astrophysics Data System (ADS)

Luspay, Tamas; Grigoriadis, Karolos

2015-10-01

Resuscitation of emergency care patients requires fast restoration of blood pressure to a target value to achieve hemodynamic stability and vital organ perfusion. A robust control design methodology is presented in this paper for regulating the blood pressure of hypotensive patients by means of the closed-loop administration of vasoactive drugs. To this end, a dynamic first-order delay model is utilised to describe the vasoactive drug response with varying parameters that represent intra-patient and inter-patient variability. The proposed framework consists of two components: first, an online model parameter estimation is carried out using a multiple-model extended Kalman-filter. Second, the estimated model parameters are used for continuously scheduling a robust linear parameter-varying (LPV) controller. The closed-loop behaviour is characterised by parameter-varying dynamic weights designed to regulate the mean arterial pressure to a target value. Experimental data of blood pressure response of anesthetised pigs to phenylephrine injection are used for validating the LPV blood pressure models. Simulation studies are provided to validate the online model estimation and the LPV blood pressure control using phenylephrine drug injection models representing patients showing sensitive, nominal and insensitive response to the drug.

Low-Cost Cold-Gas RCS for the Sloshsat Small Satellite

NASA Astrophysics Data System (ADS)

Adler, S.; Warshavsky, A.; Peretz, A.

2002-01-01

Cold gas thrusters usually provide an inexpensive, highly reliable, low-power consuming, non contaminating, and safe auxiliary propulsion means for small spacecraft. A low-cost cold-gas Reaction Control System (RCS) has been designed and developed to provide linear acceleration and rotation control of the SLOSHSAT satellite for liquid-slosh experimentation. This ESA-sponsored mini-spacecraft will be launched by the Space Shuttle and ejected into space from its hitchhiker bay. The RCS was designed and developed according to man rated safety standards, as required by NASA. The RCS comprises four identical spherical carbon/epoxy-wound stainless steel tanks, which store 1.6 kg of nitrogen at 600 bars, corresponding to a maximum rated temperature of 70°C. The relatively high pressure enables economic utilization of the limited space available in small satellites. The tanks are of a "leak before burst" design, which was subjected to a comprehensive finite-element stress analysis. They were developed and tested in accordance with MIL-STD-1522A, with a proof pressure and a minimum burst pressure of 1000 and 1700 bars, respectively. Each tank has an internal volume of 0.97 l, and is equipped with an attached accessories assembly, that includes a pyrovalve and a filter. The RCS was supplied with the tanks prepressurized and sealed to 473 bars (at 20°C). The whole system is pressurized only after the satellite is in its orbit, by activating the tank's pyrovalve. This unique approach enables to supply a sealed RCS system and propellant loading activities are not necessary before launch. Additionally, this approach has safety advantages that were meaningful to meet the NASA safety requirements. The pyrovalve includes a RAFAEL-developed initiator, which complies with MIL-STD-1576, and passed all required testing, including ESD tests with the resistor removed, as demanded by NASA for approval. The pyrovalve is of a "self seal" design, which includes a sealing mechanism, that seals the system from contamination during the pyrovalve actuation. The test port valve allows proof-pressure and leakage testing of the assembled system. The tanks and their accessories were subjected to extensive qualification testing and met the requirements of a stringent acceptance test procedure. The N2 propellant is supplied to twelve 0.8-N thrusters, at a steady regulated pressure of 15.5 bars. Accurate regulated pressure is obtained by a two stage regulating system, which accepts pressure input range of 600 to 40 bar. The thrusters were especially developed to meet the specific program requirements. They will normally be operated in pairs. For safety reasons and redundancy two relief valves are mounted downstream of the regulators. Each valve can handle the total flow with a minimum pressure rise, which defines the Maximum Operating Pressure (MEOP) in the low-pressure section of the system. The pressure surge phenomenon that follows the pyrovalve actuation was precisely analyzed, and tested in simulated conditions. A surge damper is successfully applied to the gas pipeline, significantly lowering the pressure surge. The sensitivity of the regulated pressure to the pulse modulation of the thrusters was examined. Due to the lock pressure of the regulators, and the difference between the static and dynamic regulated pressure levels, the average pressure was found to depend on the pulse duty cycle. This phenomenon was investigated and a model that predicts the pressure level according to the mass flow rate and pulse modulation was established. A breadboard test system, that completely simulates the pneumatic nature of the SLOSHSAT RCS, was constructed and used for ground test evaluation of the RCS performance in various modes of operation (continuous and pulses of various duty cycles). Computerized data acquisition and data reduction was used for pressure, temperature and mass flow measurements at several locations in the system. The breadboard system was also used for development experiments and investigation of various transient and steady state phenomena to enable successful performance prediction for operation in space. In order to establish appropriate assembly procedures for the RCS in the limited space allocated for it in the SLOSHSAT, a mock-up of the final satellite configuration, an Assembly and Testing System (ATS), was constructed. The complete RCS integrated in the ATS was subjected to vibration tests, followed by proof pressure, leakage and performance tests, as a part of the RCS qualification. All RCS components, except for the thrusters, are off-the-shelf items, adapted for space application by meeting stringent NASA/ESA man-rated mission requirements. A cooperative effort between FOKKER-SPACE and NLR of the Netherlands and RAFAEL of Israel enabled a very efficient RCS architecture that satisfies the limiting volume constraints. This approach made it possible to attain a man-rated, space-qualified cold-gas propulsion system with low-cost and safety and high- reliability attributes.

Putting Safety First in the Sky

NASA Technical Reports Server (NTRS)

2003-01-01

As a result of technology developed at NASA s Kennedy Space Center, pilots now have a hand-held personal safety device to warn them of potentially dangerous or deteriorating cabin pressure altitude conditions before hypoxia becomes a threat. The Personal Cabin Pressure Altitude Monitor and Warning System monitors cabin pressure to determine when supplemental oxygen should be used according to Federal Aviation Regulations. The device benefits both pressurized and nonpressurized aircraft operations - warning pressurized aircraft when the required safe cabin pressure altitude is compromised, and reminding nonpressurized aircraft when supplemental oxygen is needed.

Analyzing threshold pressure limitations in microfluidic transistors for self-regulated microfluidic circuits

PubMed Central

Kim, Sung-Jin; Yokokawa, Ryuji; Takayama, Shuichi

2012-01-01

This paper reveals a critical limitation in the electro-hydraulic analogy between a microfluidic membrane-valve (μMV) and an electronic transistor. Unlike typical transistors that have similar on and off threshold voltages, in hydraulic μMVs, the threshold pressures for opening and closing are significantly different and can change, even for the same μMVs depending on overall circuit design and operation conditions. We explain, in particular, how the negative values of the closing threshold pressures significantly constrain operation of even simple hydraulic μMV circuits such as autonomously switching two-valve microfluidic oscillators. These understandings have significant implications in designing self-regulated microfluidic devices. PMID:23284181

Flow-rate independent gas-mixing system for drift chambers, using solenoid valves

NASA Astrophysics Data System (ADS)

Sugano, K.

1991-03-01

We describe an inexpensive system for mixing argon and ethane gas for drift chambers which was used for an experiment at Fermilab. This system is based on the idea of intermittent mixing of gases with fixed mixing flow rates. A dual-action pressure switch senses the pressure in a mixed gas reservoir tank and operates solenoid valves to control mixing action and regulate reservoir pressure. This system has the advantages that simple controls accurately regulate the mixing ratio and that the mixing ratio is nearly flow-rate independent without readjustments. We also report the results of the gas analysis of various samplings, and the reliability of the system in long-term running.

Flow and pressure regulation in the cardiovascular system. [engineering systems model

NASA Technical Reports Server (NTRS)

Iberall, A.

1974-01-01

Principles and descriptive fragments which may contribute to a model of the regulating chains in the cardiovascular system are presented. Attention is given to the strain sensitivity of blood vessels, the law of the autonomy of the heart beat oscillator, the law of the encapsulation of body fluids, the law of the conservation of protein, the law of minimum 'arterial' pressure, the design of the 'mammalian' kidney, questions of homeokinetic organization, and the development of self-regulatory chains. Details concerning the development program for the heart muscle are considered along with the speed of response of the breathing rate and the significance of the pulmonary vascular pressure-flow characteristics.

Bifurcation analysis of nephron pressure and flow regulation

NASA Astrophysics Data System (ADS)

Barfred, Mikael; Mosekilde, Erik; Holstein-Rathlou, Niels-Henrik

1996-09-01

One- and two-dimensional continuation techniques are applied to study the bifurcation structure of a model of renal flow and pressure control. Integrating the main physiological mechanisms by which the individual nephron regulates the incoming blood flow, the model describes the interaction between the tubuloglomerular feedback and the response of the afferent arteriole. It is shown how a Hopf bifurcation leads the system to perform self-sustained oscillations if the feedback gain becomes sufficiently strong, and how a further increase of this parameter produces a folded structure of overlapping period-doubling cascades. Similar phenomena arise in response to increasing blood pressure. The numerical analyses are supported by existing experimental results on anesthetized rats.

Preliminary Performance Data on Westinghouse Electronic Power Regulator Operating on J34-WE-32 Turbojet Engine in Altitude Wind Tunnel

NASA Technical Reports Server (NTRS)

Ketchum, James R.; Blivas, Darnold; Pack, George J.

1950-01-01

The behavior of the Westinghouse electronic power regulator operating on a J34-WE-32 turbojet engine was investigated in the NACA Lewis altitude wind tunnel at the request of the Bureau of Aeronautics, Department of the Navy. The object of the program was to determine the, steady-state stability and transient characteristics of the engine under control at various altitudes and ram pressure ratios, without afterburning. Recordings of the response of the following parameters to step changes in power lever position throughout the available operating range of the engine were obtained; ram pressure ratio, compressor-discharge pressure, exhaust-nozzle area, engine speed, turbine-outlet temperature, fuel-valve position, jet thrust, air flow, turbine-discharge pressure, fuel flow, throttle position, and boost-pump pressure. Representative preliminary data showing the actual time response of these variables are presented. These data are presented in the form of reproductions of oscillographic traces.

Regulation of glottal closure and airflow in a three-dimensional phonation model: Implications for vocal intensity control

PubMed Central

Zhang, Zhaoyan

2015-01-01

Maintaining a small glottal opening across a large range of voice conditions is critical to normal voice production. This study investigated the effectiveness of vocal fold approximation and stiffening in regulating glottal opening and airflow during phonation, using a three-dimensional numerical model of phonation. The results showed that with increasing subglottal pressure the vocal folds were gradually pushed open, leading to increased mean glottal opening and flow rate. A small glottal opening and a mean glottal flow rate typical of human phonation can be maintained against increasing subglottal pressure by proportionally increasing the degree of vocal fold approximation for low to medium subglottal pressures and vocal fold stiffening at high subglottal pressures. Although sound intensity was primarily determined by the subglottal pressure, the results suggest that, to maintain small glottal opening as the sound intensity increases, one has to simultaneously tighten vocal fold approximation and/or stiffen the vocal folds, resulting in increased glottal resistance, vocal efficiency, and fundamental frequency. PMID:25698022

NASA Requirements for Ground-Based Pressure Vessels and Pressurized Systems (PVS). Revision C

NASA Technical Reports Server (NTRS)

Greulich, Owen Rudolf

2017-01-01

The purpose of this document is to ensure the structural integrity of PVS through implementation of a minimum set of requirements for ground-based PVS in accordance with this document, NASA Policy Directive (NPD) 8710.5, NASA Safety Policy for Pressure Vessels and Pressurized Systems, NASA Procedural Requirements (NPR) 8715.3, NASA General Safety Program Requirements, applicable Federal Regulations, and national consensus codes and standards (NCS).

Microinjection of acetylcholine into cerebellar fastigial nucleus induces blood depressor response in anesthetized rats.

PubMed

Zhang, Changzheng; Luo, Wen; Zhou, Peiling; Sun, Tingzhe

2016-08-26

It is well known that the cerebellar fastigial nucleus (FN) is involved in cardiovascular modulation, and has direct evidence of cholinergic activity; however, whether and how acetylcholine (ACh) in the FN modulates blood pressure has not been investigated. In this study, we analyzed mean arterial pressure, maximal change in mean arterial pressure, and the reaction time of blood pressure changes after microinjection of cholinergic reagents into the FN in anesthetized rats. The results showed that ACh evoked a concentration-dependent (10, 30 and 100mM) effect on blood pressure down-regulation. The muscarinic ACh (mACh) receptor antagonist atropine, but not the nicotinic ACh (nACh) receptor antagonist mecamylamine, blocked the ACh-mediated depressor response. The mACh receptor agonist oxotremorine M, rather than nACh receptor agonist nicotine, mimicked the ACh-mediated blood pressure decrease in a dose-dependent manner (10, 30 and 100mM). These results indicate that cholinergic input in the cerebellar FN exerts a depressor effect on systemic blood pressure regulation, and such effects are substantially contributed by mACh rather than nACh receptors, although the precise mechanism concerning the role of mACh receptor in FN-mediated blood pressure modulation remains to be elucidated. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Effects of high NaCl diet on arterial pressure in Sprague-Dawley rats with hepatic and sinoaortic denervation.

PubMed

Gao, Shuang; Tanaka, Kunihiko; Gotoh, Taro M; Morita, Hironobu

2005-08-01

The Na(+) receptor that exists in the hepatoportal region plays an important role in postprandial natriuresis and the regulation of Na(+) balance during NaCl load. Thus it would be considered that a dysfunction of the hepatic Na(+) receptor might result in the elevation of arterial pressure under a condition of high NaCl diet. To elucidate this hypothesis, arterial pressure was continuously measured during three weeks of high NaCl diet (8% NaCl) in four groups of rats: (i) intact rats, (ii) rats with hepatic denervation (HD), (iii) rats with sinoaortic denervation (SAD), and (iv) rats with SAD+HD. During a 1-week normal NaCl diet period, there was no difference in arterial pressure among the four groups. A high NaCl diet had no influence on arterial pressure in intact or HD rats; however, it significantly increased by 11 +/- 3 mmHg in SAD rats. The addition of HD to SAD had no synergistic effect on arterial pressure; i.e., in SAD+HD rats, mean arterial pressure increased by 13 +/- 1 mmHg. In conclusion, sinoaortic baroreceptor, but not hepatic Na(+) receptor, has a significant role in the long-term regulation of arterial pressure on a high NaCl diet.

Beyond gut feelings: how the gut microbiota regulates blood pressure.

PubMed

Marques, Francine Z; Mackay, Charles R; Kaye, David M

2018-01-01

Hypertension is the leading risk factor for heart disease and stroke, and is estimated to cause 9.4 million deaths globally every year. The pathogenesis of hypertension is complex, but lifestyle factors such as diet are important contributors to the disease. High dietary intake of fruit and vegetables is associated with reduced blood pressure and lower cardiovascular mortality. A critical relationship between dietary intake and the composition of the gut microbiota has been described in the literature, and a growing body of evidence supports the role of the gut microbiota in the regulation of blood pressure. In this Review, we describe the mechanisms by which the gut microbiota and its metabolites, including short-chain fatty acids, trimethylamine N-oxide, and lipopolysaccharides, act on downstream cellular targets to prevent or contribute to the pathogenesis of hypertension. These effects have a direct influence on tissues such as the kidney, the endothelium, and the heart. Finally, we consider the role of the gut microbiota in resistant hypertension, the possible intergenerational effect of the gut microbiota on blood pressure regulation, and the promising therapeutic potential of gut microbiota modification to improve health and prevent disease.

Apparatus and method to inject a reductant into an exhaust gas feedstream

DOEpatents

Viola, Michael B [Macomb Township, MI

2009-09-22

An exhaust aftertreatment system for an internal combustion engine is provided including an apparatus and method to inject a reductant into the exhaust gas feedstream. Included is a fuel metering device adapted to inject reductant into the exhaust gas feedstream and a controllable pressure regulating device. A control module is operatively connected to the reductant metering device and the controllable pressure regulating device, and, adapted to effect flow of reductant into the exhaust gas feedstream over a controllable flow range.

Subglottal pressure, tracheal airflow, and intrinsic laryngeal muscle activity during rat ultrasound vocalization

PubMed Central

2011-01-01

Vocal production requires complex planning and coordination of respiratory, laryngeal, and vocal tract movements, which are incompletely understood in most mammals. Rats produce a variety of whistles in the ultrasonic range that are of communicative relevance and of importance as a model system, but the sources of acoustic variability were mostly unknown. The goal was to identify sources of fundamental frequency variability. Subglottal pressure, tracheal airflow, and electromyographic (EMG) data from two intrinsic laryngeal muscles were measured during 22-kHz and 50-kHz call production in awake, spontaneously behaving adult male rats. During ultrasound vocalization, subglottal pressure ranged between 0.8 and 1.9 kPa. Pressure differences between call types were not significant. The relation between fundamental frequency and subglottal pressure within call types was inconsistent. Experimental manipulations of subglottal pressure had only small effects on fundamental frequency. Tracheal airflow patterns were also inconsistently associated with frequency. Pressure and flow seem to play a small role in regulation of fundamental frequency. Muscle activity, however, is precisely regulated and very sensitive to alterations, presumably because of effects on resonance properties in the vocal tract. EMG activity of cricothyroid and thyroarytenoid muscle was tonic in calls with slow or no fundamental frequency modulations, like 22-kHz and flat 50-kHz calls. Both muscles showed brief high-amplitude, alternating bursts at rates up to 150 Hz during production of frequency-modulated 50-kHz calls. A differentiated and fine regulation of intrinsic laryngeal muscles is critical for normal ultrasound vocalization. Many features of the laryngeal muscle activation pattern during ultrasound vocalization in rats are shared with other mammals. PMID:21832032

Air Pressure Responses to Sudden Vocal Tract Pressure Bleeds During Production of Stop Consonants: New Evidence of Aeromechanical Regulation

PubMed Central

Zajac, David J.; Weissler, Mark C.

2011-01-01

Two studies were conducted to evaluate short-latency vocal tract air pressure responses to sudden pressure bleeds during production of voiceless bilabial stop consonants. It was hypothesized that the occurrence of respiratory reflexes would be indicated by distinct patterns of responses as a function of bleed magnitude. In Study 1, 19 adults produced syllable trains of /pΛ/ using a mouthpiece coupled to a computer-controlled perturbator. The device randomly created bleed apertures that ranged from 0 to 40 mm2 during production of the 2nd or 4th syllable of an utterance. Although peak oral air pressure dropped in a linear manner across bleed apertures, it averaged 2 to 3 cm H2O at the largest bleed. While slope of oral pressure also decreased in a linear trend, duration of the oral pressure pulse remained relatively constant. The patterns suggest that respiratory reflexes, if present, have little effect on oral air pressure levels. In Study 2, both oral and subglottal air pressure responses were monitored in 2 adults while bleed apertures of 20 and 40 mm2 were randomly created. For 1 participant, peak oral air pressure dropped across bleed apertures, as in Study 1. Subglottal air pressure and slope, however, remained relatively stable. These patterns provide some support for the occurrence of respiratory reflexes to regulate subglottal air pressure. Overall, the studies indicate that the inherent physiologic processes of the respiratory system, which may involve reflexes, and passive aeromechanical resistance of the upper airway are capable of developing oral air pressure in the face of substantial pressure bleeds. Implications for understanding speech production and the characteristics of individuals with velopharyngeal dysfunction are discussed. PMID:15324286

Protein disulfide isomerase regulates renal AT1 receptor function and blood pressure in rats.

PubMed

Wang, Xitao; Asghar, Mohammad

2017-08-01

The role and mechanism of renal protein disulfide isomerase (PDI) in blood pressure regulation has not been tested before. Here, we test this possibility in Sprague-Dawley rats. Rats were treated with PDI inhibitor bacitracin (100 mg·kg -1 ip·day -1 for 14 days), and then blood pressure and renal angiotensin II type 1 (AT 1 ) receptor function were determined in anesthetized rats. Renal AT 1 receptor function was determined as the ability of candesartan (an AT 1 receptor blocker) to increase diuresis and natriuresis. A second set of vehicle- and bacitracin-treated rats was used to determine biochemical parameters. Systolic blood pressure as well as diastolic blood pressure increased in bacitracin-treated compared with vehicle-treated rats. Compared with vehicle, bacitracin-treated rats showed increased diuresis and natriuresis in response to candesartan (10-µg iv bolus dose) suggesting higher AT 1 receptor function in these rats. These were associated with higher renin activities in the plasma and renal tissues. Furthermore, urinary 8-isoprostane and kidney injury molecule-1 levels were higher and urinary antioxidant capacity was lower in bacitracin-treated rats. Renal protein carbonyl and nitrotyrosine levels also were higher in bacitracin- compared with vehicle-treated rats, suggesting oxidative stress burden in bacitracin-treated rats. Moreover, PDI activity decreased and its protein levels increased in renal tissues of bacitracin-treated rats. Also, nuclear levels of Nrf2 transcription factor, which regulates redox homeostasis, were decreased in bacitracin-treated rats. Furthermore, tissue levels of Keap1, an Nrf2 inhibitory molecule, and tyrosine 216-phosphorylated GSK3β protein, an Nrf2 nuclear export protein, were increased in bacitracin-treated rats. These results suggest that renal PDI by regulating Keap1-Nrf2 pathway acts as an antioxidant, maintaining redox balance, renal AT 1 receptor function, and blood pressure in rats. Copyright © 2017 the American Physiological Society.

Is Homeostatic Sleep Regulation Under Low Sleep Pressure Modified by Age?

PubMed Central

Munch, Mirjam; Knoblauch, Vera; Blatter, Katharina; Wirz-Justice, Anna; Cajochen, Christian

2007-01-01

Study Objectives: We have previously shown that healthy older volunteers react with an attenuated frontal predominance of sleep electroencephalogram (EEG) delta activity in response to high sleep pressure. Here, we investigated age-related changes in homeostatic sleep regulation under low sleep pressure conditions, with respect to regional EEG differences and their dynamics. Design: Analysis of the sleep EEG during an 8-hour baseline night, during a 40-hour multiple nap protocol (150 minutes of wakefulness and 75 minutes of sleep) and during the following 8-hour recovery night under constant posture conditions. Setting: Centre for Chronobiology, Psychiatric University Clinics, Basel, Switzerland Participants: Sixteen young (20–31 years) and 15 older (57–74 years) healthy volunteers Interventions: N/A. Measurements and Results: All-night EEG spectra revealed an increase in spindle activity (13–15.25 Hz) for both age groups, but only in the young did we find a significant decrease of delta activity (0.5–1.25 Hz) in response to low sleep pressure conditions, predominantly in occipital brain regions. However, delta activity during the first non-rapid eye movement (NREM) sleep episode was equally reduced in both age groups. This response lasted significantly longer in the young (across the first 2 NREM sleep episodes) than in the older participants (only the first NREM sleep episode). Conclusion: The initial EEG delta response to low sleep pressure was similar in healthy older and young participants. Therefore, age-related sleep deteriorations cannot solely be attributed to alterations in the homeostatic sleep-regulatory system. It is, rather, the interplay of circadian and homeostatic factors of sleep regulation, which is changed with aging. Citation: Munch M; Knoblauch V; Blatter K et al. Is homeostatic sleep regulation under low sleep pressure modified by age? SLEEP 2007;30(6):781-792. PMID:17580600

SPAKling insight into blood pressure regulation

PubMed Central

Castañeda-Bueno, María; Gamba, Gerardo

2010-01-01

Arterial hypertension is one of the most important health problems in industrialized cities. Blood pressure levels are influenced by renal salt handling and salt reabsorption in the kidney. In this Closeup, Castañeda-Bueno and Gamba discuss the work from Alessi and coworkers on the in vivo roles of the SPAK kinase in defining blood pressure levels. PMID:20112249

49 CFR 393.51 - Warning signals, air pressure and vacuum gauges.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 5 2013-10-01 2013-10-01 false Warning signals, air pressure and vacuum gauges... REGULATIONS PARTS AND ACCESSORIES NECESSARY FOR SAFE OPERATION Brakes § 393.51 Warning signals, air pressure... paragraph (f), must be equipped with a signal that provides a warning to the driver when a failure occurs in...

49 CFR 393.51 - Warning signals, air pressure and vacuum gauges.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 5 2012-10-01 2012-10-01 false Warning signals, air pressure and vacuum gauges... REGULATIONS PARTS AND ACCESSORIES NECESSARY FOR SAFE OPERATION Brakes § 393.51 Warning signals, air pressure... paragraph (f), must be equipped with a signal that provides a warning to the driver when a failure occurs in...

Self-generating oscillating pressure exercise device

NASA Technical Reports Server (NTRS)

Watenpaugh, Donald E. (Inventor)

1994-01-01

An exercise device, especially suitable for zero gravity workouts, has a collapsible chamber which generates negative pressure on the lower portion of a body situated therein. The negative pressure is generated by virtue of leg, hand and shoulder interaction which contracts and expands the chamber about the person and by virtue of air flow regulation by valve action.

49 CFR 173.127 - Class 5, Division 5.1-Definition and assignment of packing groups.

Code of Federal Regulations, 2012 CFR

2012-10-01

...) Packing Group II, any material which exhibits a mean pressure rise time less than or equal to the pressure... Packing Group I are not met. (iii) Packing Group III, any material which exhibits a mean pressure rise... packing groups. 173.127 Section 173.127 Transportation Other Regulations Relating to Transportation...

49 CFR 173.127 - Class 5, Division 5.1-Definition and assignment of packing groups.

Code of Federal Regulations, 2014 CFR

2014-10-01

...) Packing Group II, any material which exhibits a mean pressure rise time less than or equal to the pressure... Packing Group I are not met. (iii) Packing Group III, any material which exhibits a mean pressure rise... packing groups. 173.127 Section 173.127 Transportation Other Regulations Relating to Transportation...

Role of CYP1A1 in modulating the vascular and blood pressure benefits of omega-3 polyunsaturated fatty acids.

PubMed

Agbor, Larry N; Wiest, Elani F; Rothe, Michael; Schunck, Wolf-Hagen; Walker, Mary K

2014-12-01

The mechanisms that mediate the cardiovascular protective effects of omega 3 (n-3) polyunsaturated fatty acids (PUFAs) have not been fully elucidated. Cytochrome P450 1A1 efficiently metabolizes n-3 PUFAs to potent vasodilators. Thus, we hypothesized that dietary n-3 PUFAs increase nitric oxide (NO)-dependent blood pressure regulation and vasodilation in a CYP1A1-dependent manner. CYP1A1 wild-type (WT) and knockout (KO) mice were fed an n-3 or n-6 PUFA-enriched diet for 8 weeks and were analyzed for tissue fatty acids and metabolites, NO-dependent blood pressure regulation, NO-dependent vasodilation of acetylcholine (ACh) in mesenteric resistance arterioles, and endothelial NO synthase (eNOS) and phospho-Ser1177-eNOS expression in the aorta. All mice fed the n-3 PUFA diet showed significantly higher levels of n-3 PUFAs and their metabolites, and significantly lower levels of n-6 PUFAs and their metabolites. In addition, KO mice on the n-3 PUFA diet accumulated significantly higher levels of n-3 PUFAs in the aorta and kidney without a parallel increase in the levels of their metabolites. Moreover, KO mice exhibited significantly less NO-dependent regulation of blood pressure on the n-3 PUFA diet and significantly less NO-dependent, ACh-mediated vasodilation in mesenteric arterioles on both diets. Finally, the n-3 PUFA diet significantly increased aortic phospho-Ser1177-eNOS/eNOS ratio in the WT compared with KO mice. These data demonstrate that CYP1A1 contributes to eNOS activation, NO bioavailability, and NO-dependent blood pressure regulation mediated by dietary n-3 PUFAs. Copyright © 2014 by The American Society for Pharmacology and Experimental Therapeutics.

Smart Sensing and Dynamic Fitting for Enhanced Comfort and Performance of Prosthetics

DTIC Science & Technology

2015-10-01

developing the antenna pressure/shear sensors and the bubble actuators for pressure regulation. An antenna sensor that is capable of measuring shear and...liner materials. We have characterized the load bearing capability of bubble actuator arrays at different actuation pressures. A “limb-socket...laboratory test setup was developed for capturing the internal pressure change of bubble actuators when the “limb” was subjected to the external force. 15

Rankine cycle waste heat recovery system

DOEpatents

Ernst, Timothy C.; Nelson, Christopher R.

2016-05-10

This disclosure relates to a waste heat recovery (WHR) system and to a system and method for regulation of a fluid inventory in a condenser and a receiver of a Rankine cycle WHR system. Such regulation includes the ability to regulate the pressure in a WHR system to control cavitation and energy conversion.

Rankine cycle waste heat recovery system

DOEpatents

Ernst, Timothy C.; Nelson, Christopher R.

2014-08-12

This disclosure relates to a waste heat recovery (WHR) system and to a system and method for regulation of a fluid inventory in a condenser and a receiver of a Rankine cycle WHR system. Such regulation includes the ability to regulate the pressure in a WHR system to control cavitation and energy conversion.

Effect of endogenous angiotensin II on renal nerve activity and its cardiac baroreflex regulation.

PubMed

Dibona, G F; Jones, S Y; Sawin, L L

1998-11-01

The effects of physiologic alterations in endogenous angiotensin II activity on basal renal sympathetic nerve activity and its cardiac baroreflex regulation were studied. The effect of angiotensin II type 1 receptor blockade with intracerebroventricular losartan was examined in conscious rats consuming a low, normal, or high sodium diet that were instrumented for the simultaneous measurement of right atrial pressure and renal sympathetic nerve activity. The gain of cardiac baroreflex regulation of renal sympathetic nerve activity (% delta renal sympathetic nerve activity/mmHg mean right atrial pressure) was measured during isotonic saline volume loading. Intracerebroventricular losartan did not decrease arterial pressure but significantly decreased renal sympathetic nerve activity in low (-36+/-6%) and normal (-24+/-5%), but not in high (-2+/-3%) sodium diet rats. Compared with vehicle treatment, losartan treatment significantly increased cardiac baroreflex gain in low (-3.45+/-0.20 versus -2.89+/-0.17) and normal (-2.89+/-0.18 versus -2.54+/-0.14), but not in high (-2.27+/-0.15 versus -2.22+/-0.14) sodium diet rats. These results indicate that physiologic alterations in endogenous angiotensin II activity tonically influence basal levels of renal sympathetic nerve activity and its cardiac baroreflex regulation.

Mechanisms of efficacy of CBT for Cambodian refugees with PTSD: improvement in emotion regulation and orthostatic blood pressure response.

PubMed

Hinton, Devon E; Hofmann, Stefan G; Pollack, Mark H; Otto, Michael W

2009-01-01

Based on the results of a randomized controlled trial, we examined a model of the mechanisms of efficacy of culturally adapted cognitive-behavior therapy (CBT) for Cambodian refugees with pharmacology-resistant posttraumatic stress disorder (PTSD) and comordid orthostatic panic attacks (PAs). Twelve patients were in the initial treatment condition, 12 in the delayed treatment condition. The patients randomized to CBT had much greater improvement than patients in the waitlist condition on all psychometric measures and on one physiological measure-the systolic blood pressure response to orthostasis (d = 1.31)-as evaluated by repeated-measures MANOVA and planned contrasts. After receiving CBT, the Delayed Treatment Group improved on all measures, including the systolic blood pressure response to orthostasis. The CBT treatment's reduction of PTSD severity was significantly mediated by improvement in orthostatic panic and emotion regulation ability. The current study supports our model of the generation of PTSD in the Cambodian population, and suggests a key role of decreased vagal tone in the generation of orthostatic panic and PTSD in this population. It also suggests that vagal tone is involved in emotion regulation, and that both vagal tone and emotion regulation improve across treatment.

CHIP protects against cardiac pressure overload through regulation of AMPK

PubMed Central

Schisler, Jonathan C.; Rubel, Carrie E.; Zhang, Chunlian; Lockyer, Pamela; Cyr, Douglas M.; Patterson, Cam

2013-01-01

Protein quality control and metabolic homeostasis are integral to maintaining cardiac function during stress; however, little is known about if or how these systems interact. Here we demonstrate that C terminus of HSC70-interacting protein (CHIP), a regulator of protein quality control, influences the metabolic response to pressure overload by direct regulation of the catalytic α subunit of AMPK. Induction of cardiac pressure overload in Chip–/– mice resulted in robust hypertrophy and decreased cardiac function and energy generation stemming from a failure to activate AMPK. Mechanistically, CHIP promoted LKB1-mediated phosphorylation of AMPK, increased the specific activity of AMPK, and was necessary and sufficient for stress-dependent activation of AMPK. CHIP-dependent effects on AMPK activity were accompanied by conformational changes specific to the α subunit, both in vitro and in vivo, identifying AMPK as the first physiological substrate for CHIP chaperone activity and establishing a link between cardiac proteolytic and metabolic pathways. PMID:23863712

Research on power source structure optimization for East China Power Grid

NASA Astrophysics Data System (ADS)

Xu, Lingjun; Sang, Da; Zhang, Jianping; Tang, Chunyi; Xu, Da

2017-05-01

The structure of east china power grid is not reasonable for the coal power takes a much higher proportion than hydropower, at present the coal power takes charge of most peak load regulation, and the pressure of peak load regulation cannot be ignored. The nuclear power, wind power, photovoltaic, other clean energy and hydropower, coal power and wind power from outside will be actively developed in future, which increases the pressure of peak load regulation. According to development of economic and social, Load status and load prediction, status quo and planning of power source and the characteristics of power source, the peak load regulation balance is carried out and put forward a reasonable plan of power source allocation. The ultimate aim is to optimize the power source structure and to provide reference for power source allocation in east china.

The crosstalk between the kidney and the central nervous system: the role of renal nerves in blood pressure regulation.

PubMed

Nishi, Erika E; Bergamaschi, Cássia T; Campos, Ruy R

2015-04-20

What is the topic of this review? This review describes the role of renal nerves as the key carrier of signals from the kidneys to the CNS and vice versa; the brain and kidneys communicate through this carrier to maintain homeostasis in the body. What advances does it highlight? Whether renal or autonomic dysfunction is the predominant contributor to systemic hypertension is still debated. In this review, we focus on the role of the renal nerves in a model of renovascular hypertension. The sympathetic nervous system influences the renal regulation of arterial pressure and body fluid composition. Anatomical and physiological evidence has shown that sympathetic nerves mediate changes in urinary sodium and water excretion by regulating the renal tubular water and sodium reabsorption throughout the nephron, changes in the renal blood flow and the glomerular filtration rate by regulating the constriction of renal vasculature, and changes in the activity of the renin-angiotensin system by regulating the renin release from juxtaglomerular cells. Additionally, renal sensory afferent fibres project to the autonomic central nuclei that regulate blood pressure. Hence, renal nerves play a key role in the crosstalk between the kidneys and the CNS to maintain homeostasis in the body. Therefore, the increased sympathetic nerve activity to the kidney and the renal afferent nerve activity to the CNS may contribute to the outcome of diseases, such as hypertension. © 2014 The Authors. Experimental Physiology © 2014 The Physiological Society.

Gender differences in myogenic regulation along the vascular tree of the gerbil cochlea.

PubMed

Reimann, Katrin; Krishnamoorthy, Gayathri; Wier, Withrow Gil; Wangemann, Philine

2011-01-01

Regulation of cochlear blood flow is critical for hearing due to its exquisite sensitivity to ischemia and oxidative stress. Many forms of hearing loss such as sensorineural hearing loss and presbyacusis may involve or be aggravated by blood flow disorders. Animal experiments and clinical outcomes further suggest that there is a gender preference in hearing loss, with males being more susceptible. Autoregulation of cochlear blood flow has been demonstrated in some animal models in vivo, suggesting that similar to the brain, blood vessels supplying the cochlea have the ability to control flow within normal limits, despite variations in systemic blood pressure. Here, we investigated myogenic regulation in the cochlear blood supply of the Mongolian gerbil, a widely used animal model in hearing research. The cochlear blood supply originates at the basilar artery, followed by the anterior inferior cerebellar artery, and inside the inner ear, by the spiral modiolar artery and the radiating arterioles that supply the capillary beds of the spiral ligament and stria vascularis. Arteries from male and female gerbils were isolated and pressurized using a concentric pipette system. Diameter changes in response to increasing luminal pressures were recorded by laser scanning microscopy. Our results show that cochlear vessels from male and female gerbils exhibit myogenic regulation but with important differences. Whereas in male gerbils, both spiral modiolar arteries and radiating arterioles exhibited pressure-dependent tone, in females, only radiating arterioles had this property. Male spiral modiolar arteries responded more to L-NNA than female spiral modiolar arteries, suggesting that NO-dependent mechanisms play a bigger role in the myogenic regulation of male than female gerbil cochlear vessels.

Physicochemical properties of macrogol ointment and emulsion ointment blend developed for regulation of water absorption.

PubMed

Noda, Yasuhiro; Watanabe, Kazuya; Sanagawa, Akimasa; Sobajima, Yu; Fujii, Satoshi

2011-10-31

Pressure ulcers can form with excess pressure and shearing stress on skin tissue. Because pressure ulcer is often accompanies by exudates, selection of appropriate topical emulsion ointment is difficult. Blended ointments consisting of emulsion base and water-soluble base are clinically used for adjustment of wound moist environment. Because regulating the amount of wound exudates can enhance treatment efficacy, two new blended ointments were developed. LY-SL blended ointment consisted of lysozyme hydrochloride water-in-oil (w/o) emulsion (LY-cream) and sulfadiazine macrogol (polyethylene glycol) ointment (SL-pasta). TR-SL blended ointment consisted of tretinoin tocoferil oil-in-water (o/w) emulsion (TR-cream) and SL-pasta (TR-SL). LY-SL and TR-SL were applied to Franz diffusion cell with cellulose membranes for the evaluation of water absorption characteristics at 32 °C. Water absorption rate constants (mg/cm(2)/min(0.5)) were 12.5, 16.3 and 34.6 for LY-cream, TR-cream and SL-pasta, respectively. Water absorption rate constants for LY-SL and TR-SL (SL-pasta 70%) exhibited intermediate values of 21.2 and 27.2, as compared to each ointment alone, respectively. Because amount of water absorbed was linearly related to square root of time, it was suggested that water-absorbable macrogol was surrounded by oily ingredients forming matrix structure. This diffusion-limited structure may regulate water absorption capacity. This is the first report of physicochemical properties of macrogol ointment and emulsion ointment blend developed for regulation of water absorption. The blended ointment can properly regulate amount of exudates in wounds and may be useful for treatment of pressure ulcers. Copyright © 2011 Elsevier B.V. All rights reserved.

Orthostatic stress is necessary to maintain the dynamic range of cardiovascular control in space

NASA Technical Reports Server (NTRS)

Baisch, J. F.; Wolfram, G.; Beck, L.; Drummer, C.; Stormer, I.; Buckey, J.; Blomqvist, G.

2000-01-01

In the upright position, gravity fills the low-pressure systems of human circulation with blood and interstitial fluid in the sections below the diaphragm. Without gravity one pressure component in the vessels disappears and the relationship between hydrostatic pressure and oncotic pressure, which regulates fluid passage across the capillary endothelium in the terminal vascular bed, shifts constantly. The visible consequences of this are a puffy face and "bird" legs. The plasma volume shrinks in space and the range of cardiovascular control is reduced. When they stand up for the first time after landing, 30-50% of astronauts suffer from orthostatic intolerance. It remains unclear whether microgravity impairs cardiovascular reflexes, or whether it is the altered volume status that causes the cardiovascular instability following space flight. Lower body negative pressure was used in several space missions to stimulate the cardiovascular reflexes before, during and after a space flight. The results show that cardiovascular reflexes are maintained in microgravity. However, the astronauts' volume status changed in space, towards a volume-retracted state, as measurements of fluid-regulating hormones have shown. It can be hypothesized that the control of circulation and body fluid homeostasis in humans is adapted to their upright posture in the Earth's gravitational field. Autonomic control regulates fluid distribution to maintain the blood pressure in that posture, which most of us have to cope with for two-thirds of the day. A determined amount of interstitial volume is necessary to maintain the dynamic range of cardiovascular control in the upright posture; otherwise orthostatic intolerance may occur more often.

Integrative regulation of human brain blood flow

PubMed Central

Willie, Christopher K; Tzeng, Yu-Chieh; Fisher, Joseph A; Ainslie, Philip N

2014-01-01

Herein, we review mechanisms regulating cerebral blood flow (CBF), with specific focus on humans. We revisit important concepts from the older literature and describe the interaction of various mechanisms of cerebrovascular control. We amalgamate this broad scope of information into a brief review, rather than detailing any one mechanism or area of research. The relationship between regulatory mechanisms is emphasized, but the following three broad categories of control are explicated: (1) the effect of blood gases and neuronal metabolism on CBF; (2) buffering of CBF with changes in blood pressure, termed cerebral autoregulation; and (3) the role of the autonomic nervous system in CBF regulation. With respect to these control mechanisms, we provide evidence against several canonized paradigms of CBF control. Specifically, we corroborate the following four key theses: (1) that cerebral autoregulation does not maintain constant perfusion through a mean arterial pressure range of 60–150 mmHg; (2) that there is important stimulatory synergism and regulatory interdependence of arterial blood gases and blood pressure on CBF regulation; (3) that cerebral autoregulation and cerebrovascular sensitivity to changes in arterial blood gases are not modulated solely at the pial arterioles; and (4) that neurogenic control of the cerebral vasculature is an important player in autoregulatory function and, crucially, acts to buffer surges in perfusion pressure. Finally, we summarize the state of our knowledge with respect to these areas, outline important gaps in the literature and suggest avenues for future research. PMID:24396059

Neural Control of the Circulation: How Sex and Age Differences Interact in Humans

PubMed Central

Joyner, Michael J.; Barnes, Jill N.; Hart, Emma C.; Wallin, B. Gunnar; Charkoudian, Nisha

2015-01-01

The autonomic nervous system is a key regulator of cardiovascular system. In this review we focus on how sex and aging influence autonomic regulation of blood pressure in humans in an effort to understand general issues related to how the autonomic nervous system regulates blood pressure, and the cardiovascular system as a whole. Younger women generally have lower blood pressure and sympathetic activity than younger men. However, both sexes show marked inter-individual variability across age groups with significant overlap seen. Additionally, while men across the lifespan show a clear relationship between markers of whole body sympathetic activity and vascular resistance, such a relationship is not seen in young women. In this context, the ability of the sympathetic nerves to evoke vasoconstriction is lower in young women likely as a result of concurrent β2 mediated vasodilation that offsets α-adrenergic vasoconstriction. These differences reflect both central sympatho-inhibitory effects of estrogen and also its influence on peripheral vasodilation at the level of the vascular smooth muscle and endothelium. By contrast post-menopausal women show a clear relationship between markers of whole body sympathetic traffic and vascular resistance, and sympathetic activity rises progressively in both sexes with aging. These central findings in humans are discussed in the context of differences in population-based trends in blood pressure and orthostatic intolerance. The many areas where there is little sex-specific data on how the autonomic nervous system participates in the regulation of the human cardiovascular system are highlighted. PMID:25589269

International certification in developing countries: the role of internal and external institutional pressure.

PubMed

Fikru, Mahelet G

2014-11-01

This paper examines the different internal and external institutional factors that affect the decision of businesses in developing countries to adopt international certification (IC). Past studies focus on pressure from international laws, the role of multinationals, and businesses mimicking practices of their counterparts in developed countries. This paper finds that, in addition to these external factors, internal factors may have a significant role. Even though environmental regulation is weak in developing countries, governments do not ignore industrial pollution and casualties. They respond by increasing bureaucratic regulations for businesses and this can affect the decision to adopt IC. Furthermore, internal pressure may come from workers' unions that push for a safe and healthy working environment. Published by Elsevier Ltd.

Pressure Sensitive Tape and Label Surface Coating Industry: New Source Performance Standards (NSPS)

EPA Pesticide Factsheets

Learn about the New Source Performance Standards (NSPS) for pressure sensitive tape and label surface coating. Read the rule summary and history, and find the code of federal regulations and federal register citations.

Estimation of turgor pressure through comparison between single plant cell and pressurized shell mechanics

NASA Astrophysics Data System (ADS)

Durand-Smet, P.; Gauquelin, E.; Chastrette, N.; Boudaoud, A.; Asnacios, A.

2017-10-01

While plant growth is well known to rely on turgor pressure, it is challenging to quantify the contribution of turgor pressure to plant cell rheology. Here we used a custom-made micro-rheometer to quantify the viscoelastic behavior of isolated plant cells while varying their internal turgor pressure. To get insight into how plant cells adapt their internal pressure to the osmolarity of their medium, we compared the mechanical behavior of single plant cells to that of a simple, passive, pressurized shell: a soccer ball. While both systems exhibited the same qualitative behavior, a simple mechanical model allowed us to quantify turgor pressure regulation at the single cell scale.

A computational analysis of the long-term regulation of arterial pressure

PubMed Central

Beard, Daniel A.

2013-01-01

The asserted dominant role of the kidneys in the chronic regulation of blood pressure and in the etiology of hypertension has been debated since the 1970s. At the center of the theory is the observation that the acute relationships between arterial pressure and urine production—the acute pressure-diuresis and pressure-natriuresis curves—physiologically adapt to perturbations in pressure and/or changes in the rate of salt and volume intake. These adaptations, modulated by various interacting neurohumoral mechanisms, result in chronic relationships between water and salt excretion and pressure that are much steeper than the acute relationships. While the view that renal function is the dominant controller of arterial pressure has been supported by computer models of the cardiovascular system known as the “Guyton-Coleman model”, no unambiguous description of a computer model capturing chronic adaptation of acute renal function in blood pressure control has been presented. Here, such a model is developed with the goals of: 1. representing the relevant mechanisms in an identifiable mathematical model; 2. identifying model parameters using appropriate data; 3. validating model predictions in comparison to data; and 4. probing hypotheses regarding the long-term control of arterial pressure and the etiology of primary hypertension. The developed model reveals: long-term control of arterial blood pressure is primarily through the baroreflex arc and the renin-angiotensin system; and arterial stiffening provides a sufficient explanation for the etiology of primary hypertension associated with ageing. Furthermore, the model provides the first consistent explanation of the physiological response to chronic stimulation of the baroreflex. PMID:24555102

Factors associated with blood oxygen partial pressure and carbon dioxide partial pressure regulation during respiratory extracorporeal membrane oxygenation support: data from a swine model.

PubMed

Park, Marcelo; Mendes, Pedro Vitale; Costa, Eduardo Leite Vieira; Barbosa, Edzangela Vasconcelos Santos; Hirota, Adriana Sayuri; Azevedo, Luciano Cesar Pontes

2016-01-01

The aim of this study was to explore the factors associated with blood oxygen partial pressure and carbon dioxide partial pressure. The factors associated with oxygen - and carbon dioxide regulation were investigated in an apneic pig model under veno-venous extracorporeal membrane oxygenation support. A predefined sequence of blood and sweep flows was tested. Oxygenation was mainly associated with extracorporeal membrane oxygenation blood flow (beta coefficient = 0.036mmHg/mL/min), cardiac output (beta coefficient = -11.970mmHg/L/min) and pulmonary shunting (beta coefficient = -0.232mmHg/%). Furthermore, the initial oxygen partial pressure and carbon dioxide partial pressure measurements were also associated with oxygenation, with beta coefficients of 0.160 and 0.442mmHg/mmHg, respectively. Carbon dioxide partial pressure was associated with cardiac output (beta coefficient = 3.578mmHg/L/min), sweep gas flow (beta coefficient = -2.635mmHg/L/min), temperature (beta coefficient = 4.514mmHg/ºC), initial pH (beta coefficient = -66.065mmHg/0.01 unit) and hemoglobin (beta coefficient = 6.635mmHg/g/dL). In conclusion, elevations in blood and sweep gas flows in an apneic veno-venous extracorporeal membrane oxygenation model resulted in an increase in oxygen partial pressure and a reduction in carbon dioxide partial pressure 2, respectively. Furthermore, without the possibility of causal inference, oxygen partial pressure was negatively associated with pulmonary shunting and cardiac output, and carbon dioxide partial pressure was positively associated with cardiac output, core temperature and initial hemoglobin.

Diastolic coronary artery pressure-flow velocity relationships in conscious man.

PubMed

Dole, W P; Richards, K L; Hartley, C J; Alexander, G M; Campbell, A B; Bishop, V S

1984-09-01

We characterised the diastolic pressure-flow velocity relationship in the normal left coronary artery of conscious man before and after vasodilatation with angiographic contrast medium. Phasic coronary artery pressure and flow velocity were measured in ten patients during individual diastoles (0.5 to 1.0 s) using a 20 MHz catheter-tipped, pulsed Doppler transducer. All pressure-flow velocity curves were linear over the diastolic pressure range of 110 +/- 15 (SD) mmHg to 71 +/- 7 mmHg (r = 0.97 +/- 0.01). In the basal state, values for slope and extrapolated zero flow pressure intercept averaged 0.35 +/- 0.12 cm X s-1 X mmHg-1 and 51.7 +/- 8.6 mmHg, respectively. Vasodilatation resulted in a 2.5 +/- 0.5 fold increase in mean flow velocity. The diastolic pressure-flow velocity relationship obtained during peak vasodilatation compared to that during basal conditions was characterised by a steeper slope (0.80 +/- 0.48 cm X s-1 X mmHg-1, p less than 0.001) and lower extrapolated zero flow pressure intercept (37.9 +/- 9.8 mmHg, p less than 0.05). Mean right atrial pressure for the group averaged 4.4 +/- 1.7 mmHg, while left ventricular end-diastolic pressure averaged 8.7 +/- 2.8 mmHg. These observations in man are similar to data reported in the canine coronary circulation which are consistent with a vascular waterfall model of diastolic flow regulation. In this model, coronary blood flow may be regulated by changes in diastolic zero flow pressure as well as in coronary resistance.

A computational analysis of the long-term regulation of arterial pressure.

PubMed

Beard, Daniel A; Pettersen, Klas H; Carlson, Brian E; Omholt, Stig W; Bugenhagen, Scott M

2013-01-01

The asserted dominant role of the kidneys in the chronic regulation of blood pressure and in the etiology of hypertension has been debated since the 1970s. At the center of the theory is the observation that the acute relationships between arterial pressure and urine production-the acute pressure-diuresis and pressure-natriuresis curves-physiologically adapt to perturbations in pressure and/or changes in the rate of salt and volume intake. These adaptations, modulated by various interacting neurohumoral mechanisms, result in chronic relationships between water and salt excretion and pressure that are much steeper than the acute relationships. While the view that renal function is the dominant controller of arterial pressure has been supported by computer models of the cardiovascular system known as the "Guyton-Coleman model", no unambiguous description of a computer model capturing chronic adaptation of acute renal function in blood pressure control has been presented. Here, such a model is developed with the goals of: 1. representing the relevant mechanisms in an identifiable mathematical model; 2. identifying model parameters using appropriate data; 3. validating model predictions in comparison to data; and 4. probing hypotheses regarding the long-term control of arterial pressure and the etiology of primary hypertension. The developed model reveals: long-term control of arterial blood pressure is primarily through the baroreflex arc and the renin-angiotensin system; and arterial stiffening provides a sufficient explanation for the etiology of primary hypertension associated with ageing. Furthermore, the model provides the first consistent explanation of the physiological response to chronic stimulation of the baroreflex.

Pressure modulation of Ras-membrane interactions and intervesicle transfer.

PubMed

Kapoor, Shobhna; Werkmüller, Alexander; Goody, Roger S; Waldmann, Herbert; Winter, Roland

2013-04-24

Proteins attached to the plasma membrane frequently encounter mechanical stresses, including high hydrostatic pressure (HHP) stress. Signaling pathways involving membrane-associated small GTPases (e.g., Ras) have been identified as critical loci for pressure perturbation. However, the impact of mechanical stimuli on biological outputs is still largely terra incognita. The present study explores the effect of HHP on the membrane association, dissociation, and intervesicle transfer process of N-Ras by using a FRET-based assay to obtain the kinetic parameters and volumetric properties along the reaction path of these processes. Notably, membrane association is fostered upon pressurization. Conversely, depending on the nature and lateral organization of the lipid membrane, acceleration or retardation is observed for the dissociation step. In addition, HHP can be inferred as a positive regulator of N-Ras clustering, in particular in heterogeneous membranes. The susceptibility of membrane interaction to pressure raises the idea of a role of lipidated signaling molecules as mechanosensors, transducing mechanical stimuli to chemical signals by regulating their membrane binding and dissociation. Finally, our results provide first insights into the influence of pressure on membrane-associated Ras-controlled signaling events in organisms living under extreme environmental conditions such as those that are encountered in the deep sea and sub-seafloor environments, where pressures reach the kilobar (100 MPa) range.

Regulation of Cell Cycle and Stress Responses to Hydrostatic Pressure in Fission Yeast

PubMed Central

George, Vinoj T.; Brooks, Gavin

2007-01-01

We have investigated the cellular responses to hydrostatic pressure by using the fission yeast Schizosaccharomyces pombe as a model system. Exposure to sublethal levels of hydrostatic pressure resulted in G2 cell cycle delay. This delay resulted from Cdc2 tyrosine-15 (Y-15) phosphorylation, and it was abrogated by simultaneous disruption of the Cdc2 kinase regulators Cdc25 and Wee1. However, cell cycle delay was independent of the DNA damage, cytokinesis, and cell size checkpoints, suggesting a novel mechanism of Cdc2-Y15 phosphorylation in response to hydrostatic pressure. Spc1/Sty1 mitogen-activated protein (MAP) kinase, a conserved member of the eukaryotic stress-activated p38, mitogen-activated protein (MAP) kinase family, was rapidly activated after pressure stress, and it was required for cell cycle recovery under these conditions, in part through promoting polo kinase (Plo1) phosphorylation on serine 402. Moreover, the Spc1 MAP kinase pathway played a key role in maintaining cell viability under hydrostatic pressure stress through the bZip transcription factor, Atf1. Further analysis revealed that prestressing cells with heat increased barotolerance, suggesting adaptational cross-talk between these stress responses. These findings provide new insight into eukaryotic homeostasis after exposure to pressure stress. PMID:17699598

Overexpression of EAR1 and SSH4 that encode PPxY proteins in the multivesicular body provides stability to tryptophan permease Tat2, allowing yeast cells to grow under high hydrostatic pressure

NASA Astrophysics Data System (ADS)

Hiraki, Toshiki; Usui, Keiko; Abe, Fumiyoshi

2010-12-01

Tryptophan uptake in yeast Saccharomyces cerevisiae is susceptible to high hydrostatic pressure and it limits the growth of tryptophan auxotrophic (Trp-) strains under pressures of 15-25 MPa. The susceptibility of tryptophan uptake is accounted for by the pressure-induced degradation of tryptophan permease Tat2 occurring in a Rsp5 ubiquitin ligase-dependent manner. Ear1 and Ssh4 are multivesicular body proteins that physically interact with Rsp5. We found that overexpression of either of the EAR1 or SSH4 genes enabled the Trp- cells to grow at 15-25 MPa. EAR1 and SSH4 appeared to provide stability to the Tat2 protein when overexpressed. The result suggests that Ear1 and Ssh4 negatively regulate Rsp5 on ubiquitination of Tat2. Currently, high hydrostatic pressure is widely used in bioscience and biotechnology for structurally perturbing macromolecules such as proteins and lipids or in food processing and sterilizing microbes. We suggest that hydrostatic pressure is an operative experimental parameter to screen yeast genes specifically for regulation of Tat2 through the function of Rsp5 ubiquitin ligase.

Automatic safety rod for reactors. [LMFBR

DOEpatents

Germer, J.H.

1982-03-23

An automatic safety rod for a nuclear reactor containing neutron absorbing material and designed to be inserted into a reactor core after a loss-of-flow. Actuation is based upon either a sudden decrease in core pressure drop or the pressure drop decreases below a predetermined minimum value. The automatic control rod includes a pressure regulating device whereby a controlled decrease in operating pressure due to reduced coolant flow does not cause the rod to drop into the core.

Automatic safety rod for reactors

DOEpatents

Germer, John H.

1988-01-01

An automatic safety rod for a nuclear reactor containing neutron absorbing material and designed to be inserted into a reactor core after a loss-of-core flow. Actuation is based upon either a sudden decrease in core pressure drop or the pressure drop decreases below a predetermined minimum value. The automatic control rod includes a pressure regulating device whereby a controlled decrease in operating pressure due to reduced coolant flow does not cause the rod to drop into the core.

Microenvironment is involved in cellular response to hydrostatic pressures during chondrogenesis of mesenchymal stem cells.

PubMed

Ye, Rui; Hao, Jin; Song, Jinlin; Zhao, Zhihe; Fang, Shanbao; Wang, Yating; Li, Juan

2014-06-01

Chondrocytes integrate numerous microenvironmental cues to mount physiologically relevant differentiation responses, and the regulation of mechanical signaling in chondrogenic differentiation is now coming into intensive focus. To facilitate tissue-engineered chondrogenesis by mechanical strategy, a thorough understanding about the interactional roles of chemical factors under mechanical stimuli in regulating chondrogenesis is in great need. Therefore, this study attempts to investigate the interaction of rat MSCs with their microenvironment by imposing dynamic and static hydrostatic pressure through modulating gaseous tension above the culture medium. Under dynamic pressure, chemical parameters (pH, pO2, and pCO2) were kept in homeostasis. In contrast, pH was remarkably reduced due to increased pCO2 under static pressure. MSCs under the dynamically pressured microenvironment exhibited a strong accumulation of GAG within and outside the alginate beads, while cells under the statically pressured environment lost newly synthesized GAG into the medium with a speed higher than its production. In addition, the synergic influence on expression of chondrogenic genes was more persistent under dynamic pressure than that under static pressure. This temporal contrast was similar to that of activation of endogenous TGF-β1. Taken altogether, it indicates that a loading strategy which can keep a homeostatic chemical microenvironment is preferred, since it might sustain the stimulatory effects of mechanical stimuli on chondrogenesis via activation of endogenous TGF-β1. © 2013 Wiley Periodicals, Inc.

Cytoglobin regulates blood pressure and vascular tone through nitric oxide metabolism in the vascular wall

PubMed Central

Liu, Xiaoping; El-Mahdy, Mohamed A.; Boslett, James; Varadharaj, Saradhadevi; Hemann, Craig; Abdelghany, Tamer M.; Ismail, Raed S.; Little, Sean C.; Zhou, Danlei; Thuy, Le Thi Thanh; Kawada, Norifumi; Zweier, Jay L.

2017-01-01

The identity of the specific nitric oxide dioxygenase (NOD) that serves as the main in vivo regulator of O2-dependent NO degradation in smooth muscle remains elusive. Cytoglobin (Cygb) is a recently discovered globin expressed in fibroblasts and smooth muscle cells with unknown function. Cygb, coupled with a cellular reducing system, efficiently regulates the rate of NO consumption by metabolizing NO in an O2-dependent manner with decreased NO consumption in physiological hypoxia. Here we show that Cygb is a major regulator of NO degradation and cardiovascular tone. Knockout of Cygb greatly prolongs NO decay, increases vascular relaxation, and lowers blood pressure and systemic vascular resistance. We further demonstrate that downregulation of Cygb prevents angiotensin-mediated hypertension. Thus, Cygb has a critical role in the regulation of vascular tone and disease. We suggest that modulation of the expression and NOD activity of Cygb represents a strategy for the treatment of cardiovascular disease. PMID:28393874

Occupational burns from oxygen resuscitator fires: the hazard of aluminum regulators.

PubMed

Hodous, Thomas K; Washenitz, Frank; Newton, Barry

2002-07-01

There have been over 30 incidents of oxygen resuscitator fires over the last 6 years, causing severe burns to a number of fire fighters, emergency medical service personnel, health care workers, and patients. The National Institute for Occupational Safety and Health (NIOSH) was requested to investigate three such incidents. NIOSH conducted site investigations of the incidents, and the requesters also sent the involved oxygen resuscitators to a forensic engineering company for a causal analysis. The investigated fires were associated with aluminum regulators, all from one manufacturer, on compressed pure oxygen cylinders. The investigations indicated that the cause of the fires was an initial small ignition in the high-pressure area of the aluminum regulator, which then consumed itself in a massive burnout. Aluminum regulators used with high-pressure oxygen systems are subject to rare, but potentially catastrophic combustion in normal use. Replacement of such regulators with those made of more fire-resistant materials or designs, as well as education and improved safety practices are needed to reduce this hazard.

Cytoglobin regulates blood pressure and vascular tone through nitric oxide metabolism in the vascular wall

NASA Astrophysics Data System (ADS)

Liu, Xiaoping; El-Mahdy, Mohamed A.; Boslett, James; Varadharaj, Saradhadevi; Hemann, Craig; Abdelghany, Tamer M.; Ismail, Raed S.; Little, Sean C.; Zhou, Danlei; Thuy, Le Thi Thanh; Kawada, Norifumi; Zweier, Jay L.

2017-04-01

The identity of the specific nitric oxide dioxygenase (NOD) that serves as the main in vivo regulator of O2-dependent NO degradation in smooth muscle remains elusive. Cytoglobin (Cygb) is a recently discovered globin expressed in fibroblasts and smooth muscle cells with unknown function. Cygb, coupled with a cellular reducing system, efficiently regulates the rate of NO consumption by metabolizing NO in an O2-dependent manner with decreased NO consumption in physiological hypoxia. Here we show that Cygb is a major regulator of NO degradation and cardiovascular tone. Knockout of Cygb greatly prolongs NO decay, increases vascular relaxation, and lowers blood pressure and systemic vascular resistance. We further demonstrate that downregulation of Cygb prevents angiotensin-mediated hypertension. Thus, Cygb has a critical role in the regulation of vascular tone and disease. We suggest that modulation of the expression and NOD activity of Cygb represents a strategy for the treatment of cardiovascular disease.

Regulation of the pulmonary circulation

PubMed Central

Lee, G. de J.

1971-01-01

Factors regulating pressure and flow in the lungs are reviewed with particular emphasis on their role in regulating blood flow velocity and distribution within the lung capillaries. The behaviour of the pulmonary arterial, system, alveolar capillaries, and pulmonary venous system are considered individually. The effect of heart disease on lung capillary blood flow is examined. PMID:4929437

49 CFR 192.739 - Pressure limiting and regulating stations: Inspection and testing.

Code of Federal Regulations, 2010 CFR

2010-10-01

... inspections and tests to determine that it is— (1) In good mechanical condition; (2) Adequate from the... limit is as follows: If the MAOP produces a hoop stress that is: Then the pressure limit is: Greater...

49 CFR 192.739 - Pressure limiting and regulating stations: Inspection and testing.

Code of Federal Regulations, 2012 CFR

2012-10-01

... inspections and tests to determine that it is— (1) In good mechanical condition; (2) Adequate from the... limit is as follows: If the MAOP produces a hoop stress that is: Then the pressure limit is: Greater...

49 CFR 192.739 - Pressure limiting and regulating stations: Inspection and testing.

Code of Federal Regulations, 2014 CFR

2014-10-01

... inspections and tests to determine that it is— (1) In good mechanical condition; (2) Adequate from the... limit is as follows: If the MAOP produces a hoop stress that is: Then the pressure limit is: Greater...

49 CFR 192.739 - Pressure limiting and regulating stations: Inspection and testing.

Code of Federal Regulations, 2013 CFR

2013-10-01

... inspections and tests to determine that it is— (1) In good mechanical condition; (2) Adequate from the... limit is as follows: If the MAOP produces a hoop stress that is: Then the pressure limit is: Greater...

49 CFR 192.739 - Pressure limiting and regulating stations: Inspection and testing.

Code of Federal Regulations, 2011 CFR

2011-10-01

... inspections and tests to determine that it is— (1) In good mechanical condition; (2) Adequate from the... limit is as follows: If the MAOP produces a hoop stress that is: Then the pressure limit is: Greater...

System Regulates the Water Contents of Fuel-Cell Streams

NASA Technical Reports Server (NTRS)

Vasquez, Arturo; Lazaroff, Scott

2005-01-01

An assembly of devices provides for both humidification of the reactant gas streams of a fuel cell and removal of the product water (the water generated by operation of the fuel cell). The assembly includes externally-sensing forward-pressure regulators that supply reactant gases (fuel and oxygen) at variable pressures to ejector reactant pumps. The ejector supply pressures depend on the consumption flows. The ejectors develop differential pressures approximately proportional to the consumption flow rates at constant system pressure and with constant flow restriction between the mixer-outlet and suction ports of the ejectors. For removal of product water from the circulating oxygen stream, the assembly includes a water/gas separator that contains hydrophobic and hydrophilic membranes. The water separator imposes an approximately constant flow restriction, regardless of the quality of the two-phase flow that enters it from the fuel cell. The gas leaving the water separator is nearly 100 percent humid. This gas is returned to the inlet of the fuel cell along with a quantity of dry incoming oxygen, via the oxygen ejector, thereby providing some humidification.

Passive and active response of bacteria under mechanical compression

NASA Astrophysics Data System (ADS)

Garces, Renata; Miller, Samantha; Schmidt, Christoph F.; Byophysics Team; Institute of Medical Sciences Collaboration

Bacteria display simple but fascinating cellular structures and geometries. Their shapes are the result of the interplay between osmotic pressure and cell wall construction. Typically, bacteria maintain a high difference of osmotic pressure (on the order of 1 atm) to the environment. This pressure difference (turgor pressure) is supported by the cell envelope, a composite of lipid membranes and a rigid cell wall. The response of the cell envelope to mechanical perturbations such as geometrical confinements is important for the cells survival. Another key property of bacteria is the ability to regulate turgor pressure after abrupt changes of external osmotic conditions. This response relies on the activity of mechanosensitive (MS) channels: membrane proteins that release solutes in response to excessive stress in the cell envelope. We here present experimental data on the mechanical response of the cell envelope and on turgor regulation of bacteria subjected to compressive forces. We indent living cells with micron-sized beads attached to the cantilever of an atomic force microscope (AFM). This approach ensures global deformation of the cell. We show that such mechanical loading is sufficient to gate mechanosensitive channels in isosmotic conditions.

Functional analysis of a regulator of G-protein signaling CgRGS1 in the rubber tree anthracnose fungus Colletotrichum gloeosporioides.

PubMed

Liu, Zhi-Qiang; Wu, Man-Li; Ke, Zhi-Jian; Liu, Wen-Bo; Li, Xiao-Yu

2018-04-01

Colletotrichum gloeosporioides is the causal agent of rubber anthracnose, which is also one of the important biological factors threatening the development of natural rubber industry in the world. Regulators of G-protein signaling (RGS) are key negative regulators of G-proteins, which play important roles in growth, development and pathogenic processes of plant pathogens. In this study, a RGS gene CgRGS1 was functionally characterized in C. gloeosporioides. Compared to the wild type, the CgRGS1 deletion mutant had slow vegetative growth, reduced conidia with multi-end germination, low appressorium formation rate, high resistance to oxidative stress and SDS. Moreover, the mutant was sensitive to osmotic pressure and showed decreased virulence. In conclusion, CgRGS1 is involved in regulation of vegetative growth, conidiation, germination, appressorium formation, oxidative stress, osmotic pressure response and pathogenicity in C. gloeosporioides.

Using materials research results in new regulations -- The Swedish approach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gott, K.

1995-12-31

Swedish regulations are normally divided into two sections: the first part is the compulsory text and the second part explains very briefly the ideas behind the regulations and section consists of an interpretive text. This second part explains very briefly the ideas behind the regulations and gives advice as to how to apply the regulations, acceptable testing and analysis methods, and references to other standards and relevant documents. In the new regulations, which were approved by the Board of SKI in September 1994 and are effective from 1st January 1995, a number of innovations have been included concerning chemistry andmore » environmental degradation of the primary pressure boundary in Light Water Reactors. With regard to chemistry SKI will no longer approve the various parameters in the technical specifications (such as conductivity and impurity concentrations) but will require that the utilities have a chemistry control program in place which ensures the integrity of the primary pressure boundary and does not expose it to environments (such as impurities and decontamination chemicals) for which it was not designed. SKI can at any time control that such a program exists and assess its compatibility with these goals, either during routine inspections or as part of special theme inspections. Crack growth rates have been specified for different materials stainless steels, and the nickel base alloy types 600 and 182. Different environments have also been specified: water chemistry within and outside plant specifications as well as normal and hydrogen water chemistry conditions. Stress corrosion cracking in pressurized water reactor systems is also treated separately in the regulations, but not discussed specifically here.« less

System analysis of the dynamic response of the coronary circulation to a sudden change in heart rate.

PubMed

Dankelman, J; Stassen, H G; Spaan, J A

1990-03-01

In this study the response of driving pressure/flow ration on an abrupt change in heart rate was analysed. The difference between the response obtained with constant pressure and constant flow perfusion was also studied. The responses show a fast initial reversed phase followed by a slow phase caused by regulation. To test whether the initial phase could be the result of mechanical changes in the coronary circulation, a model for regulation was extended by the addition of four different mechanical models originating from the literature. These extended models were able to explain the fast initial phase. However, the mechanical model consisting of an intramyocardial compliance (C = 0.08 ml mm Hg-1 100 g-1) with a variable venous resistance, and the model consisting of a waterfall and a small compliance (C = 0.007 ml mm Hg-1 100g-1) both explained these responses best. The analysis showed that there is no direct relationship between rate of change of vascular tone and rate of change of pressure/flow ratio. However, on the basis of the two extended models, it can be predicted that the half-time for the response of regulation to be complete is about 9s with constant pressure perfusion and 15 s with constant flow perfusion.

How does yeast respond to pressure?

PubMed

Fernandes, P M B

2005-08-01

The brewing and baking yeast Saccharomyces cerevisiae has been used as a model for stress response studies of eukaryotic cells. In this review we focus on the effect of high hydrostatic pressure (HHP) on S. cerevisiae. HHP exerts a broad effect on yeast cells characteristic of common stresses, mainly associated with protein alteration and lipid bilayer phase transition. Like most stresses, pressure induces cell cycle arrest. Below 50 MPa (500 atm) yeast cell morphology is unaffected whereas above 220 MPa wild-type cells are killed. S. cerevisiae cells can acquire barotolerance if they are pretreated with a sublethal stress due to temperature, ethanol, hydrogen peroxide, or pressure. Nevertheless, pressure only leads to protection against severe stress if, after pressure pretreatment, the cells are also re-incubated at room pressure. We attribute this effect to the inhibition of the protein synthesis apparatus under HHP. The global genome expression analysis of S. cerevisiae cells submitted to HHP revealed a stress response profile. The majority of the up-regulated genes are involved in stress defense and carbohydrate metabolism while most repressed genes belong to the cell cycle progression and protein synthesis categories. However, the signaling pathway involved in the pressure response is still to be elucidated. Nitric oxide, a signaling molecule involved in the regulation of a large number of cellular functions, confers baroprotection. Furthermore, S. cerevisiae cells in the early exponential phase submitted to 50-MPa pressure show induction of the expression level of the nitric oxide synthase inducible isoform. As pressure becomes an important biotechnological tool, studies concerning this kind of stress in microorganisms are imperative.

Reid Vapor Pressure (RVP) of Gasoline Spreadsheet Example Key for Requirements at 40 CFR 80.47(g) and 80.47(l)

EPA Pesticide Factsheets

This guidance deals with the self-qualification of analytical test methods at a testing facility for measuring Reid Vapor Pressure (RVP) of gasoline to meet precision requirements codified in regulations.

Reed Valve Regulates Welding Back-Purge Pressure

NASA Technical Reports Server (NTRS)

Coby, J. Ben, Jr.; Weeks, Jack L.

1991-01-01

Simple modification yields welds of better quality. Reed valve halves fluctuations in pressure in back-purge chamber attached to workpiece undergoing keyhole plasma arc welding. Identical to one used in fuel system of two-cycle gasoline engine. Backbead smoother, and weld penetrates more uniformly.

16 CFR 1401.1 - Scope.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS SELF PRESSURIZED... Product Safety Act (15 U.S.C. 2076(e)) for marketers and importers of self-pressurized consumer products... product stating that it contains a chlorofluorocarbon that may harm the public health and environment by...

16 CFR 1401.1 - Scope.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS SELF PRESSURIZED... Product Safety Act (15 U.S.C. 2076(e)) for marketers and importers of self-pressurized consumer products... product stating that it contains a chlorofluorocarbon that may harm the public health and environment by...

16 CFR 1401.1 - Scope.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS SELF PRESSURIZED... Product Safety Act (15 U.S.C. 2076(e)) for marketers and importers of self-pressurized consumer products... product stating that it contains a chlorofluorocarbon that may harm the public health and environment by...

Piston rod seal for a Stirling engine

DOEpatents

Shapiro, Wilbur

1984-01-01

In a piston rod seal for a Stirling engine, a hydrostatic bearing and differential pressure regulating valve are utilized to provide for a low pressure differential across a rubbing seal between the hydrogen and oil so as to reduce wear on the seal.

Uncertainty in Steady-State Diagnostics of a Current-Pressure Transducer: How Confident are We in Diagnosing Faults

DTIC Science & Technology

2014-10-02

and off-nominal behav- ior of the I/ P transducer; however, sensor measurements are not fast enough to capture brief transient states that are in...nasa.gov 3 NASA Ames Research Center, Moffett Field, CA 94035, USA kai.goebel@nasa.gov ABSTRACT Current-Pressure (I/ P ) transducers are effective...transducers (I/ P transducer or IPT) are ef- fective pressure regulators that vary the output pressure de- pending on the supplied electrical current

Pressure regulator

DOEpatents

Ebeling, Jr., Robert W.; Weaver, Robert B.

1979-01-01

The pressure within a pressurized flow reactor operated under harsh environmental conditions is controlled by establishing and maintaining a fluidized bed of uniformly sized granular material of selected density by passing the gas from the reactor upwardly therethrough at a rate sufficient to fluidize the bed and varying the height of the bed by adding granular material thereto or removing granular material therefrom to adjust the backpressure on the flow reactor.

Adjustable-Pressure Mandrel For Making Composite Tubes

NASA Technical Reports Server (NTRS)

Jacoy, Paul J.; Schmitigal, Wesley P.

1993-01-01

Inflatable inner mandrel enables application of any desired pressure (within reasonable limits) during curing stage in fabrication of fiber/matrix composite tube. Consists mainly of sheath of silicone rubber sealed on aluminum tube. Composite material laid up on mandrel and enclosed in rigid outer die. Sheath on inner mandrel inflated to requisite pressure and regulated during curing. Assembly then placed in oven and cured at specified temperature.

Nonlinear Pressure-Flow Relationship Is Able to Detect Asymmetry of Brain Blood Circulation Associated with Midline Shift

PubMed Central

Lo, Men-Tzung; Peng, C.K.; Novak, Vera; Schmidt, Eric A.; Kumar, Ajay; Czosnyka, Marek

2009-01-01

Abstract Reliable and noninvasive assessment of cerebral blood flow regulation is a major challenge in acute care monitoring. This study assessed dynamics of flow regulation and its relationship to asymmetry of initial computed tomography (CT) scan using multimodal pressure flow (MMPF) analysis. Data of 27 patients (38 ± 15 years old) with traumatic brain injury (TBI) were analyzed. Patients were selected from bigger cohort according to criteria of having midline shift on initial CT scan and intact skull (no craniotomy or bone flap). The MMPF analysis was used to extract the oscillations in cerebral perfusion pressure (CPP) and blood flow velocity (BFV) signals at frequency of artificial ventilation, and to calculate the instantaneous phase difference between CPP and BFV oscillations. Mean CPP-BFV phase difference was used to quantify pressure and flow relationship. The TBI subjects had smaller mean BP-BFV phase shifts (left, 8.7 ± 9.6; right 10.2 ± 8.3 MCAs, mean ± SD) than values previously obtained in healthy subjects (left, 37.3 ± 7.6 degrees; right, 38.0 ± 8.9 degrees; p < 0.0001), suggesting impaired blood flow regulation after TBI. The difference in phase shift between CPP and BFV in the left and right side was strongly correlated to the midline shift (R = 0.78; p < 0.0001). These findings indicate that the MMPF method allows reliable assessment of alterations in pressure and flow relationship after TBI. Moreover, mean pressure-flow phase shift is sensitive to the displacement of midline of the brain, and may potentially serve as a marker of asymmetry of cerebral autoregulation. PMID:19196074

Stomatal action directly feeds back on leaf turgor: new insights into the regulation of the plant water status from non-invasive pressure probe measurements.

PubMed

Ache, Peter; Bauer, Hubert; Kollist, Hannes; Al-Rasheid, Khaled A S; Lautner, Silke; Hartung, Wolfram; Hedrich, Rainer

2010-06-01

Uptake of CO(2) by the leaf is associated with loss of water. Control of stomatal aperture by volume changes of guard cell pairs optimizes the efficiency of water use. Under water stress, the protein kinase OPEN STOMATA 1 (OST1) activates the guard-cell anion release channel SLOW ANION CHANNEL-ASSOCIATED 1 (SLAC1), and thereby triggers stomatal closure. Plants with mutated OST1 and SLAC1 are defective in guard-cell turgor regulation. To study the effect of stomatal movement on leaf turgor using intact leaves of Arabidopsis, we used a new pressure probe to monitor transpiration and turgor pressure simultaneously and non-invasively. This probe permits routine easy access to parameters related to water status and stomatal conductance under physiological conditions using the model plant Arabidopsis thaliana. Long-term leaf turgor pressure recordings over several weeks showed a drop in turgor during the day and recovery at night. Thus pressure changes directly correlated with the degree of plant transpiration. Leaf turgor of wild-type plants responded to CO(2), light, humidity, ozone and abscisic acid (ABA) in a guard cell-specific manner. Pressure probe measurements of mutants lacking OST1 and SLAC1 function indicated impairment in stomatal responses to light and humidity. In contrast to wild-type plants, leaves from well-watered ost1 plants exposed to a dry atmosphere wilted after light-induced stomatal opening. Experiments with open stomata mutants indicated that the hydraulic conductance of leaf stomata is higher than that of the root-shoot continuum. Thus leaf turgor appears to rely to a large extent on the anion channel activity of autonomously regulated stomatal guard cells.

49 CFR 179.201-2 - [Reserved

Code of Federal Regulations, 2010 CFR

2010-10-01

... Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS SPECIFICATIONS FOR TANK CARS Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.201-2 [Reserved] ...

78 FR 77656 - Aerosols and Similar Pressurized Containers-Meeting To Discuss the Method of Sale for Packages...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-24

..., Packaging and Labeling Regulation (UPLR) in NIST Handbook 130, ``Uniform Laws and Regulations in the Areas... permit price and quantity comparison is forbidden.'' Products using BOV technology versus traditional...

Regulated-current dc power supply for gaseous-discharge lamps

NASA Technical Reports Server (NTRS)

Freeman, W.; Huguenin, D.

1970-01-01

Controlled current source having a high output resistance feeds continuous-flow hydrogen lamps in vacuum-ultraviolet photometric equipment. The power supply, also used with low-pressure sealed lamps, has a short recovery time and smooth regulation without overshoot.

Obesity is the major determinant of the abnormalities in blood pressure found in young women with the polycystic ovary syndrome.

PubMed

Luque-Ramírez, Manuel; Alvarez-Blasco, Francisco; Mendieta-Azcona, Covadonga; Botella-Carretero, José I; Escobar-Morreale, Héctor F

2007-06-01

Obesity and insulin resistance predispose patients with the polycystic ovary syndrome (PCOS) to abnormalities in blood pressure regulation. Our objective was to evaluate the impact of obesity on the blood pressure profiles of PCOS patients. PATIENTS, SETTING, AND DESIGN: Thirty-six PCOS patients and 20 healthy women participated in a case-control study at an academic hospital. We conducted ambulatory blood pressure monitoring and office blood pressure determinations. Hypertension (defined as increased office blood pressure confirmed by ambulatory blood pressure monitoring or by masked hypertension) was present in 12 PCOS patients and eight controls (P = 0.618). No differences between patients and controls were found in office and ambulatory blood pressure monitoring values and heart rate, yet the nocturnal decrease in mean blood pressure was smaller in patients (P = 0.038). Obese women (13 patients and eight controls) had increased frequencies of office hypertension (29% compared with 3% in lean plus overweight women, P = 0.005), increased diastolic (P = 0.009) and mean (P = 0.015) office blood pressure values, and increased heart rate values during the daytime (P = 0.038), nighttime (P = 0.002), and 24-h (P = 0.009) periods, independently of having PCOS or not. The frequency of a nocturnal nondipper pattern was 62% in obese PCOS patients, compared with 26% in lean plus overweight PCOS patients (P = 0.036) and 25% in obese and in lean plus overweight controls. Abnormalities in the regulation of blood pressure are common in young women with PCOS, yet, with the exception of the nondipper pattern, these abnormalities result from the frequent association of this syndrome with obesity.

Hydraulic Pressure during Fluid Flow Regulates Purinergic Signaling and Cytoskeleton Organization of Osteoblasts.

PubMed

Gardinier, Joseph D; Gangadharan, Vimal; Wang, Liyun; Duncan, Randall L

2014-06-01

During physiological activities, osteoblasts experience a variety of mechanical forces that stimulate anabolic responses at the cellular level necessary for the formation of new bone. Previous studies have primarily investigated the osteoblastic response to individual forms of mechanical stimuli. However in this study, we evaluated the response of osteoblasts to two simultaneous, but independently controlled stimuli; fluid flow-induced shear stress (FSS) and static or cyclic hydrostatic pressure (SHP or CHP, respectively). MC3T3-E1 osteoblasts-like cells were subjected to 12dyn/cm 2 FSS along with SHP or CHP of varying magnitudes to determine if pressure enhances the anabolic response of osteoblasts during FSS. For both SHP and CHP, the magnitude of hydraulic pressure that induced the greatest release of ATP during FSS was 15 mmHg. Increasing the hydraulic pressure to 50 mmHg or 100 mmHg during FSS attenuated the ATP release compared to 15 mmHg during FSS. Decreasing the magnitude of pressure during FSS to atmospheric pressure reduced ATP release to that of basal ATP release from static cells and inhibited actin reorganization into stress fibers that normally occurred during FSS with 15 mmHg of pressure. In contrast, translocation of nuclear factor kappa B (NFκB) to the nucleus was independent of the magnitude of hydraulic pressure and was found to be mediated through the activation of phospholipase-C (PLC), but not src kinase. In conclusion, hydraulic pressure during FSS was found to regulate purinergic signaling and actin cytoskeleton reorganization in the osteoblasts in a biphasic manner, while FSS alone appeared to stimulate NFκB translocation. Understanding the effects of hydraulic pressure on the anabolic responses of osteoblasts during FSS may provide much needed insights into the physiologic effects of coupled mechanical stimuli on osteogenesis.

Hydraulic Pressure during Fluid Flow Regulates Purinergic Signaling and Cytoskeleton Organization of Osteoblasts

PubMed Central

Gardinier, Joseph D.; Gangadharan, Vimal; Wang, Liyun; Duncan, Randall L.

2014-01-01

During physiological activities, osteoblasts experience a variety of mechanical forces that stimulate anabolic responses at the cellular level necessary for the formation of new bone. Previous studies have primarily investigated the osteoblastic response to individual forms of mechanical stimuli. However in this study, we evaluated the response of osteoblasts to two simultaneous, but independently controlled stimuli; fluid flow-induced shear stress (FSS) and static or cyclic hydrostatic pressure (SHP or CHP, respectively). MC3T3-E1 osteoblasts-like cells were subjected to 12dyn/cm2 FSS along with SHP or CHP of varying magnitudes to determine if pressure enhances the anabolic response of osteoblasts during FSS. For both SHP and CHP, the magnitude of hydraulic pressure that induced the greatest release of ATP during FSS was 15 mmHg. Increasing the hydraulic pressure to 50 mmHg or 100 mmHg during FSS attenuated the ATP release compared to 15 mmHg during FSS. Decreasing the magnitude of pressure during FSS to atmospheric pressure reduced ATP release to that of basal ATP release from static cells and inhibited actin reorganization into stress fibers that normally occurred during FSS with 15 mmHg of pressure. In contrast, translocation of nuclear factor kappa B (NFκB) to the nucleus was independent of the magnitude of hydraulic pressure and was found to be mediated through the activation of phospholipase-C (PLC), but not src kinase. In conclusion, hydraulic pressure during FSS was found to regulate purinergic signaling and actin cytoskeleton reorganization in the osteoblasts in a biphasic manner, while FSS alone appeared to stimulate NFκB translocation. Understanding the effects of hydraulic pressure on the anabolic responses of osteoblasts during FSS may provide much needed insights into the physiologic effects of coupled mechanical stimuli on osteogenesis. PMID:24910719

Factors associated with blood oxygen partial pressure and carbon dioxide partial pressure regulation during respiratory extracorporeal membrane oxygenation support: data from a swine model

PubMed Central

Park, Marcelo; Mendes, Pedro Vitale; Costa, Eduardo Leite Vieira; Barbosa, Edzangela Vasconcelos Santos; Hirota, Adriana Sayuri; Azevedo, Luciano Cesar Pontes

2016-01-01

Objective The aim of this study was to explore the factors associated with blood oxygen partial pressure and carbon dioxide partial pressure. Methods The factors associated with oxygen - and carbon dioxide regulation were investigated in an apneic pig model under veno-venous extracorporeal membrane oxygenation support. A predefined sequence of blood and sweep flows was tested. Results Oxygenation was mainly associated with extracorporeal membrane oxygenation blood flow (beta coefficient = 0.036mmHg/mL/min), cardiac output (beta coefficient = -11.970mmHg/L/min) and pulmonary shunting (beta coefficient = -0.232mmHg/%). Furthermore, the initial oxygen partial pressure and carbon dioxide partial pressure measurements were also associated with oxygenation, with beta coefficients of 0.160 and 0.442mmHg/mmHg, respectively. Carbon dioxide partial pressure was associated with cardiac output (beta coefficient = 3.578mmHg/L/min), sweep gas flow (beta coefficient = -2.635mmHg/L/min), temperature (beta coefficient = 4.514mmHg/ºC), initial pH (beta coefficient = -66.065mmHg/0.01 unit) and hemoglobin (beta coefficient = 6.635mmHg/g/dL). Conclusion In conclusion, elevations in blood and sweep gas flows in an apneic veno-venous extracorporeal membrane oxygenation model resulted in an increase in oxygen partial pressure and a reduction in carbon dioxide partial pressure 2, respectively. Furthermore, without the possibility of causal inference, oxygen partial pressure was negatively associated with pulmonary shunting and cardiac output, and carbon dioxide partial pressure was positively associated with cardiac output, core temperature and initial hemoglobin. PMID:27096671

Development and evaluation of a self-regulating alternating pressure air cushion.

PubMed

Nakagami, Gojiro; Sanada, Hiromi; Sugama, Junko

2015-03-01

To investigate the effect of alternating air cells of a newly developed dynamic cushion on interface pressure and tissue oxygenation levels. This cross-over experimental study included 19 healthy volunteers. The dynamic cushion used has an automatic self-regulating alternating pressure air-cell system with 35 small and four large air cells for maintaining posture while seated. This cushion also has 17 bottoming-out detectors that automatically inflate the air cells to release a high interface pressure. To assess the effect of this alternating system, participants sat on the new cushion with an alternating system or static system for 30 min and then performed push-ups. The interface pressure was monitored by pressure-sensitive and conductive ink film sensors and tissue oxygenation levels were monitored by near-infrared spectroscopy. A reactive hyperaemia indicator was calculated using tissue oxygenation levels as an outcome measure. The peak interface pressure was not significantly different between the groups. The reactive hyperaemia indicator was significantly higher in the static group than in the alternating group. An alternating system has beneficial effects on blood oxygenation levels without increasing interface pressure. Therefore, our new cushion is promising for preventing pressure ulcers with patients with limited ability to perform push-ups. Implications for Rehabilitation A dynamic cushion was developed, which consists of a uniquely-designed air-cell layout, detectors for bottoming out, and an alternating system with multiple air-cell lines. The alternating system did not increase interface pressure and it significantly reduced reactive hyperaemia after 30 min of sitting in healthy volunteers. This cushion is a new option for individuals who require stable posture but have limitations in performing scheduled push-ups for prevention of pressure ulcers.

Effects of PPARγ Agonist Pioglitazone on Redox-Sensitive Cellular Signaling in Young Spontaneously Hypertensive Rats

PubMed Central

Dovinová, Ima; Barancik, Miroslav; Zorad, Stefan; Gajdosechová, Lucia; Gresová, Linda; Cacanyiova, Sona; Kristek, Frantisek; Balis, Peter; Chan, Julie Y. H.

2013-01-01

PPARγ receptor plays an important role in oxidative stress response. Its agonists can influence vascular contractility in experimental hypertension. Our study was focused on the effects of a PPARγ agonist pioglitazone (PIO) on blood pressure regulation, vasoactivity of vessels, and redox-sensitive signaling at the central (brainstem, BS) and peripheral (left ventricle, LV) levels in young prehypertensive rats. 5-week-old SHR were treated either with PIO (10 mg/kg/day, 2 weeks) or with saline using gastric gavage. Administration of PIO significantly slowed down blood pressure increase and improved lipid profile and aortic relaxation after insulin stimulation. A significant increase in PPARγ expression was found only in BS, not in LV. PIO treatment did not influence NOS changes, but had tissue-dependent effect on SOD regulation and increased SOD activity, observed in LV. The treatment with PIO differentially affected also the levels of other intracellular signaling components: Akt kinase increased in the the BS, while β-catenin level was down-regulated in the BS and up-regulated in the LV. We found that the lowering of blood pressure in young SHR can be connected with insulin sensitivity of vessels and that β-catenin and SOD levels are important agents mediating PIO effects in the BS and LV. PMID:24454335

CONVECTION REACTOR

DOEpatents

Hammond, R.P.; King, L.D.P.

1960-03-22

An homogeneous nuclear power reactor utilizing convection circulation of the liquid fuel is proposed. The reactor has an internal heat exchanger looated in the same pressure vessel as the critical assembly, thereby eliminating necessity for handling the hot liquid fuel outside the reactor pressure vessel during normal operation. The liquid fuel used in this reactor eliminates the necessity for extensive radiolytic gas rocombination apparatus, and the reactor is resiliently pressurized and, without any movable mechanical apparatus, automatically regulates itself to the condition of criticality during moderate variations in temperature snd pressure and shuts itself down as the pressure exceeds a predetermined safe operating value.

Spectral indices of cardiovascular adaptations to short-term simulated microgravity exposure

NASA Technical Reports Server (NTRS)

Patwardhan, A. R.; Evans, J. M.; Berk, M.; Grande, K. J.; Charles, J. B.; Knapp, C. F.

1995-01-01

We investigated the effects of exposure to microgravity on the baseline autonomic balance in cardiovascular regulation using spectral analysis of cardiovascular variables measured during supine rest. Heart rate, arterial pressure, radial flow, thoracic fluid impedance and central venous pressure were recorded from nine volunteers before and after simulated microgravity, produced by 20 hours of 6 degrees head down bedrest plus furosemide. Spectral powers increased after simulated microgravity in the low frequency region (centered at about 0.03 Hz) in arterial pressure, heart rate and radial flow, and decreased in the respiratory frequency region (centered at about 0.25 Hz) in heart rate. Reduced heart rate power in the respiratory frequency region indicates reduced parasympathetic influence on the heart. A concurrent increase in the low frequency power in arterial pressure, heart rate, and radial flow indicates increased sympathetic influence. These results suggest that the baseline autonomic balance in cardiovascular regulation is shifted towards increased sympathetic and decreased parasympathetic influence after exposure to short-term simulated microgravity.

Lower body negative pressure as a tool for research in aerospace physiology and military medicine

NASA Technical Reports Server (NTRS)

Convertino, V. A.

2001-01-01

Lower body negative pressure (LBNP) has been extensively used for decades in aerospace physiological research as a tool to investigate cardiovascular mechanisms that are associated with or underlie performance in aerospace and military environments. In comparison with clinical stand and tilt tests, LBNP represents a relatively safe methodology for inducing highly reproducible hemodynamic responses during exposure to footward fluid shifts similar to those experienced under orthostatic challenge. By maintaining an orthostatic challenge in a supine posture, removal of leg support (muscle pump) and head motion (vestibular stimuli) during LBNP provides the capability to isolate cardiovascular mechanisms that regulate blood pressure. LBNP can be used for physiological measurements, clinical diagnoses and investigational research comparisons of subject populations and alterations in physiological status. The applications of LBNP to the study of blood pressure regulation in spaceflight, groundbased simulations of low gravity, and hemorrhage have provided unique insights and understanding for development of countermeasures based on physiological mechanisms underlying the operational problems.

Modification of carbon fabrics by radio-frequency capacitive discharge at low pressure to regulate mechanical properties of carbon fiber reinforced plastics based on it

NASA Astrophysics Data System (ADS)

Garifullin, A. R.; Krasina, I. V.; Skidchenko, E. A.; Shaekhov, M. F.; Tikhonova, N. V.

2017-01-01

To increase the values of mechanical properties of carbon fiber (CF) composite materials used in sports equipment production the method of radio-frequency capacitive (RFC) low-pressure plasma treatment in air was proposed. Previously it was found that this type of modification allows to effectively regulate the surface properties of fibers of different nature. This treatment method differs from the traditional ones by efficiency and environmental friendliness as it does not require the use of aggressive, environmentally hazardous chemicals. In this paper it was established that RFC low-pressure air plasma treatment of carbon fabrics enhances the interlaminar shear strength (ILSS) of carbon fiber reinforced plastic (CFRP). As a result of experimental studies of CF by Fourier Transform Infrared (FTIR) spectroscopy method it was proved that after radio-frequency capacitive plasma treatment at low pressure in air the oxygen-containing functional groups is grafted on the surface. These groups improve adhesion at the interface “matrix-fiber”.

[Arterial hypertension in children].

PubMed

Mota-Hernández, F

1993-07-01

It is considered hypertension in children, the persistent increase of the blood pressure values above percentile 95 for age and sex, in no less than three determinations, with adequate register techniques. Blood pressure is maintained mainly by the regulation of metabolism of sodium and water in the intravascular space, through the adequate balance of intake, filtration, reabsorption and renal throughout. It is also regulated by hormonal factors. Weight gain control in teen-agers could be useful to prevent high blood pressure in adults. In children, it is generally secondary to renal, reno-vascular, endocrinological or tumoral diseases. Clinical manifestations and the recommended diagnostic procedures are analysed to detect the most frequent causes of hypertension at different ages. Most cases response with antihypertensive drugs in combination with hyposodic diet. For the hypertensive crisis, asa diuretics and powerful antihypertensive drugs may be employed. Patients with chronic renal insufficiency could also need dialytic treatments. Renovascular diseases require almost always invasive treatments. Better prognosis in children with severe high blood pressure is related with recent diagnostic procedures, surgical techniques and antihypertensive drugs improvements.

A whole-body mathematical model for intracranial pressure dynamics.

PubMed

Lakin, William D; Stevens, Scott A; Tranmer, Bruce I; Penar, Paul L

2003-04-01

Most attempts to study intracranial pressure using lumped-parameter models have adopted the classical "Kellie-Monro Doctrine," which considers the intracranial space to be a closed system that is confined within the nearly-rigid skull, conserves mass, and has equal inflow and outflow. The present work revokes this Doctrine and develops a mathematical model for the dynamics of intracranial pressures, volumes, and flows that embeds the intracranial system in extensive whole-body physiology. The new model consistently introduces compartments representing the tissues and vasculature of the extradural portions of the body, including both the thoracic region and the lower extremities. In addition to vascular connections, a spinal-subarachnoid cerebrospinal fluid (CSF) compartment bridges intracranial and extracranial physiology allowing explict buffering of intracranial pressure fluctuations by the spinal theca. The model contains cerebrovascular autoregulation, regulation of systemic vascular pressures by the sympathetic nervous system, regulation of CSF production in the choroid plexus, a lymphatic system, colloid osmotic pressure effects, and realistic descriptions of cardiac output. To validate the model in situations involving normal physiology, the model's response to a realistic pulsatile cardiac output is examined. A well-known experimentally-derived intracranial pressure-volume relationship is recovered by using the model to simulate CSF infusion tests, and the effect on cerebral blood flow of a change in body position is also examined. Cardiac arrest and hemorrhagic shock are simulated to demonstrate the predictive capabilities of the model in pathological conditions.

Effect of pericardiocentesis on circulating concentrations of atrial natriuretic hormone and arginine vasopressin in dogs with spontaneous pericardial effusion.

PubMed

Stokhof, A A; Overduin, L M; Mol, J A; Rijnberk, A

1994-04-01

Factors regulating the secretion of atrial natriuretic hormone (ANH) and arginine vasopressin (AVP) have not been elucidated fully. In several studies the release of these peptides has been studied by inducing both increased atrial pressure and atrial distension. A few studies employ cardiac tamponade, allowing the effect of atrial pressure and atrial stretch to be studied separately. In eleven dogs with spontaneous cardiac tamponade the effect of pericardiocentesis on circulating concentrations of ANP and AVP was studied. Pericardiocentesis was followed by a prompt rise in (non-elevated) plasma ANH concentrations from 21.6 +/- 7.3 to 65.4 +/- 17.1 pmol/l (mean +/- SEM). The initially slightly elevated AVP concentration of 5.5 +/- 1.5 pmol/l declined following pericardiocentesis to 2.1 +/- 0.5 pmol/l. In three dogs the systolic arterial pressure was measured indirectly and the central venous pressure was measured with a fluid-filled catheter. Before and after pericardiocentesis arterial pressure readings did not change significantly. Central venous pressure values showed an immediate very steep significant decrease after centesis. It is concluded that ANH release is primarily regulated by stretch and not by atrial pressure, that plasma AVP concentrations are moderately elevated in cardiac tamponade and that in cardiac tamponade pericardiocentesis causes a rapid decline in plasma AVP concentration.

Elastin Is Differentially Regulated by Pressure Therapy in a Porcine Model of Hypertrophic Scar.

PubMed

Carney, Bonnie C; Liu, Zekun; Alkhalil, Abdulnaser; Travis, Taryn E; Ramella-Roman, Jessica; Moffatt, Lauren T; Shupp, Jeffrey W

Beneficial effects of pressure therapy for hypertrophic scars have been reported, but the mechanisms of action are not fully understood. This study evaluated elastin and its contribution to scar pliability. The relationship between changes in Vancouver Scar Scale (VSS) scores of pressure-treated scars and differential regulation of elastin was assessed. Hypertrophic scars were created and assessed weekly using VSS and biopsy procurement. Pressure treatment began on day 70 postinjury. Treated scars were compared with untreated shams. Treatment lasted 2 weeks, through day 84, and scars were assessed weekly through day 126. Transcript and protein levels of elastin were quantified. Pressure treatment resulted in lower VSS scores compared with sham-treated scars. Pliability (VSSP) was a key contributor to this difference. At day 70 pretreatment, VSSP = 2. Without treatment, sham-treated scars became less pliable, while pressure-treated scars became more pliable. The percentage of elastin in scars at day 70 was higher than in uninjured skin. Following treatment, the percentage of elastin increased and continued to increase through day 126. Untreated sham scars did not show a similar increase. Quantification of Verhoeff-Van Gieson staining corroborated the findings and immunofluorescence revealed the alignment of elastin fibers. Pressure treatment results in increased protein level expression of elastin compared with sham-untreated scars. These findings further characterize the extracellular matrix's response to the application of pressure as a scar treatment, which will contribute to the refinement of rehabilitation practices and ultimately improvements in functional and psychosocial outcomes for patients.

Genome-wide association study in Chinese identifies novel loci for blood pressure and hypertension

PubMed Central

Lu, Xiangfeng; Wang, Laiyuan; Lin, Xu; Huang, Jianfeng; Charles Gu, C.; He, Meian; Shen, Hongbing; He, Jiang; Zhu, Jingwen; Li, Huaixing; Hixson, James E.; Wu, Tangchun; Dai, Juncheng; Lu, Ling; Shen, Chong; Chen, Shufeng; He, Lin; Mo, Zengnan; Hao, Yongchen; Mo, Xingbo; Yang, Xueli; Li, Jianxin; Cao, Jie; Chen, Jichun; Fan, Zhongjie; Li, Ying; Zhao, Liancheng; Li, Hongfan; Lu, Fanghong; Yao, Cailiang; Yu, Lin; Xu, Lihua; Mu, Jianjun; Wu, Xianping; Deng, Ying; Hu, Dongsheng; Zhang, Weidong; Ji, Xu; Guo, Dongshuang; Guo, Zhirong; Zhou, Zhengyuan; Yang, Zili; Wang, Renping; Yang, Jun; Zhou, Xiaoyang; Yan, Weili; Sun, Ningling; Gao, Pingjin; Gu, Dongfeng

2015-01-01

Hypertension is a common disorder and the leading risk factor for cardiovascular disease and premature deaths worldwide. Genome-wide association studies (GWASs) in the European population have identified multiple chromosomal regions associated with blood pressure, and the identified loci altogether explain only a small fraction of the variance for blood pressure. The differences in environmental exposures and genetic background between Chinese and European populations might suggest potential different pathways of blood pressure regulation. To identify novel genetic variants affecting blood pressure variation, we conducted a meta-analysis of GWASs of blood pressure and hypertension in 11 816 subjects followed by replication studies including 69 146 additional individuals. We identified genome-wide significant (P < 5.0 × 10−8) associations with blood pressure, which included variants at three new loci (CACNA1D, CYP21A2, and MED13L) and a newly discovered variant near SLC4A7. We also replicated 14 previously reported loci, 8 (CASZ1, MOV10, FGF5, CYP17A1, SOX6, ATP2B1, ALDH2, and JAG1) at genome-wide significance, and 6 (FIGN, ULK4, GUCY1A3, HFE, TBX3-TBX5, and TBX3) at a suggestive level of P = 1.81 × 10−3 to 5.16 × 10−8. These findings provide new mechanistic insights into the regulation of blood pressure and potential targets for treatments. PMID:25249183

Mechanisms of blood pressure regulation that differ in men repeatedly exposed to high-G acceleration.

PubMed

Convertino, V A

2001-04-01

The purpose of this study was to test the hypothesis that repeated exposure to high acceleration (G) would be associated with enhanced functions of specific mechanisms of blood pressure regulation. We measured heart rate (HR), stroke volume (SV), cardiac output (), mean arterial blood pressure, central venous pressure, forearm and leg vascular resistance, catecholamines, and changes in leg volume (%DeltaLV) during various protocols of lower body negative pressure (LBNP), carotid stimulation, and infusions of adrenoreceptor agonists in 10 males after three training sessions on different days over a period of 5-7 days using a human centrifuge (G trained). These responses were compared with the same measurements in 10 males who were matched for height, weight, and fitness but did not undergo G training (controls). Compared with the control group, G-trained subjects demonstrated greater R-R interval response to equal carotid baroreceptor stimulation (7.3 +/- 1.2 vs. 3.9 +/- 0.4 ms/mmHg, P = 0.02), less vasoconstriction to equal low-pressure baroreceptor stimulation (-1.4 +/- 0.2 vs. -2.6 +/- 0.3 U/mmHg, P = 0.01), and higher HR (-1.2 +/- 0.2 vs. -0.5 +/- 0.1 beats. min(-1). mmHg(-1), P = 0.01) and alpha-adrenoreceptor response (32.8 +/- 3.4 vs. 19.5 +/- 4.7 U/mmHg, P = 0.04) to equal dose of phenylephrine. During graded LBNP, G-trained subjects had less decline in and SV, %DeltaLV, and elevation in thoracic impedance. G-trained subjects also had greater total blood (6,497 +/- 496 vs. 5,438 +/- 228 ml, P = 0.07) and erythrocyte (3,110 +/- 364 vs. 2,310 +/- 96 ml, P = 0.06) volumes. These results support the hypothesis that exposure to repeated high G is associated with increased capacities of mechanisms that underlie blood pressure regulation.

Mechanisms of blood pressure regulation that differ in men repeatedly exposed to high-G acceleration

NASA Technical Reports Server (NTRS)

Convertino, V. A.

2001-01-01

The purpose of this study was to test the hypothesis that repeated exposure to high acceleration (G) would be associated with enhanced functions of specific mechanisms of blood pressure regulation. We measured heart rate (HR), stroke volume (SV), cardiac output (), mean arterial blood pressure, central venous pressure, forearm and leg vascular resistance, catecholamines, and changes in leg volume (%DeltaLV) during various protocols of lower body negative pressure (LBNP), carotid stimulation, and infusions of adrenoreceptor agonists in 10 males after three training sessions on different days over a period of 5-7 days using a human centrifuge (G trained). These responses were compared with the same measurements in 10 males who were matched for height, weight, and fitness but did not undergo G training (controls). Compared with the control group, G-trained subjects demonstrated greater R-R interval response to equal carotid baroreceptor stimulation (7.3 +/- 1.2 vs. 3.9 +/- 0.4 ms/mmHg, P = 0.02), less vasoconstriction to equal low-pressure baroreceptor stimulation (-1.4 +/- 0.2 vs. -2.6 +/- 0.3 U/mmHg, P = 0.01), and higher HR (-1.2 +/- 0.2 vs. -0.5 +/- 0.1 beats. min(-1). mmHg(-1), P = 0.01) and alpha-adrenoreceptor response (32.8 +/- 3.4 vs. 19.5 +/- 4.7 U/mmHg, P = 0.04) to equal dose of phenylephrine. During graded LBNP, G-trained subjects had less decline in and SV, %DeltaLV, and elevation in thoracic impedance. G-trained subjects also had greater total blood (6,497 +/- 496 vs. 5,438 +/- 228 ml, P = 0.07) and erythrocyte (3,110 +/- 364 vs. 2,310 +/- 96 ml, P = 0.06) volumes. These results support the hypothesis that exposure to repeated high G is associated with increased capacities of mechanisms that underlie blood pressure regulation.

Hypothesis: the regulation of the partial pressure of oxygen by the serotonergic nervous system in hypoxia.

PubMed

Devereux, Diana; Ikomi-Kumm, Julie

2013-03-01

The regulation of the partial pressure of oxygen by the serotonergic nervous system in hypoxia is a hypothesis, which proposes an inherent operative system in homo sapiens that allows central nervous system and endocrine-mediated vascular system adaption to variables in partial pressure of oxygen, pH and body composition, while maintaining sufficient oxygen saturation for the immune system and ensuring protection of major organs in hypoxic and suboptimal conditions. While acknowledging the importance of the Henderson-Hasselbalch equation in the regulation of acid base balance, the hypothesis seeks to define the specific neuroendocrine/vascular mechanisms at work in regulating acid base balance in hypoxia and infection. The SIA (serotonin-immune-adrenergic) system is proposed as a working model, which allows central nervous system and endocrine-mediated macro- and micro vascular 'fine tuning'. The neurotransmitter serotonin serves as a 'hypoxic sensor' in concert with other operators to orchestrate homeostatic balance in normal and pathological states. The SIA system finely regulates oxygen, fuel and metabolic buffering systems at local sites to ensure optimum conditions for the immune response. The SIA system is fragile and its operation may be affected by infection, stress, diet, environmental toxins and lack of exercise. The hypothesis provides new insight in the area of neuro-gastroenterology, and emphasizes the importance of diet and nutrition as a complement in the treatment of infection, as well as the normalization of intestinal flora following antibiotic therapy. Copyright © 2012 Elsevier Ltd. All rights reserved.

Comparison of choroidal and optic nerve head blood flow regulation during changes in ocular perfusion pressure.

PubMed

Schmidl, Doreen; Boltz, Agnes; Kaya, Semira; Werkmeister, Rene; Dragostinoff, Nikolaus; Lasta, Michael; Polska, Elzbieta; Garhöfer, Gerhard; Schmetterer, Leopold

2012-07-01

We compared the response of choroidal and optic nerve head blood flow (ChBF, ONHBF) in response to an increase in ocular perfusion pressure (OPP) during isometric exercise and during a decrease in OPP during an artificial increase in intraocular pressure (IOP). We included 96 healthy subjects in our study. In 48 subjects OPP was increased by 6 minutes of squatting, and either ONHBF (n = 24) or ChBF (n = 24) was measured continuously. In 48 other healthy subjects either ONHBF (n = 24) or ChBF (n = 24) was measured continuously during a period of artificial increase in IOP using a suction cup. All blood flow measurements were done using laser Doppler flowmetry. During all experiments the response in blood flow was less pronounced than the response in OPP, indicating for flow regulation. During isometric exercise ChBF regulated better than ONHBF (P = 0.023). During artificial IOP increase ONHBF regulated better than ChBF (P = 0.001). Inter-individual variability in blood flow responses was high. During squatting ONHBF decreased considerably below baseline ONHBF when OPP fluctuated in 3 subjects, although OPP still was much higher than at baseline. This phenomenon was not observed in the choroid. Our data indicate that regulation of ChBF and ONHBF during changes in OPP is different and complex. In some subjects performing squatting, considerable ONHBF reductions were observed during OPP fluctuations, although OPP still was high. Whether this predisposes to ocular disease remains unclear.

49 CFR 179.200-24 - Stamping.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS SPECIFICATIONS FOR TANK CARS Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.200-24 Stamping. (a) To...

49 CFR 179.102-2 - Chlorine.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS SPECIFICATIONS FOR TANK CARS Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.102-2 Chlorine. (a...

49 CFR 179.100-14 - Bottom outlets.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS SPECIFICATIONS FOR TANK CARS Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.100-14 Bottom outlets...

49 CFR 179.100-16 - Attachments.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS SPECIFICATIONS FOR TANK CARS Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.100-16 Attachments. (a...

49 CFR 179.201-4 - Material.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS SPECIFICATIONS FOR TANK CARS Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.201-4 Material. All fittings...

49 CFR 179.100-20 - Stamping.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS SPECIFICATIONS FOR TANK CARS Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.100-20 Stamping. (a) To...

49 CFR 179.103-5 - Bottom outlets.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS SPECIFICATIONS FOR TANK CARS Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.103-5 Bottom outlets...

76 FR 81922 - Nationwide Categorical Waivers Under Section 1605 (Buy American) of the American Recovery and...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-29

... States in sufficient and reasonably available quantities and of a satisfactory quality), with respect to...) Thermostatic Regulator Valves that regulate the flow of hot water or low pressure steam through free-standing...

Materials to Engineer the Immune System

DTIC Science & Technology

2010-04-01

presentation of danger signals to regulate the ratio of distinct DC subtypes was next examined by immobilizing TLR-activating, polyethylenimine (PEI...compression molded. The resulting disc was allowed to equilibrate within a high-pressure CO2 environment, and a rapid reduction in pressure causes the...pressure CO2 process to foam macroporous PLG matrices incorporating tumor lysates. To incorporate CpG-ODNs into PLG scaffolds, we first con- densed CpG-ODN

Photosynthetic responses to altitude: an explanation based on optimality principles

NASA Astrophysics Data System (ADS)

Wang, Han; Prenticce, Iain Colin; Davis, Tyler; Keenan, Trevor; Wright, Ian; Peng, Changhui

2017-04-01

Increasing altitude is commonly accompanied by a declining ratio of leaf-internal to ambient CO2 partial pressures (ci:ca; hereafter, χ) and an increase in carboxylation capacity (Vcmax), while carbon assimilation (A) shows little to no change. Here we provide a consistent, quantitative explanation for these responses based on the 'least-cost hypothesis' for the regulation of χ and the 'co-ordination hypothesis' for the regulation of Vcmax. With leaf temperature held constant, our analysis predicts that the cost of maintaining water transport capacity increases with altitude (due to declining atmospheric pressure and increasing vapour pressure deficit, VPD) while the cost of maintaining carboxylation capacity decreases (due to the enhanced affinity of Rubisco for CO2 at low O2 partial pressures). Both effects favour investment in carboxylation capacity rather than water transport capacity. The response of A then reflects the competing effects of stronger CO2 limitation at low ci versus increased radiation penetration through a thinner atmosphere. These effects of atmospheric pressure are expected to be most strongly expressed in herbaceous plants that can maintain leaf temperatures in a narrow range. In leaves closely coupled to the atmosphere additional effects of declining temperature on photosynthesis are expected to modify but not obliterate those of pressure.

Energy efficient continuous flow ash lockhopper

NASA Technical Reports Server (NTRS)

Collins, Earl R., Jr. (Inventor); Suitor, Jerry W. (Inventor); Dubis, David (Inventor)

1989-01-01

The invention relates to an energy efficient continuous flow ash lockhopper, or other lockhopper for reactor product or byproduct. The invention includes an ash hopper at the outlet of a high temperature, high pressure reactor vessel containing heated high pressure gas, a fluidics control chamber having an input port connected to the ash hopper's output port and an output port connected to the input port of a pressure letdown means, and a control fluid supply for regulating the pressure in the control chamber to be equal to or greater than the internal gas pressure of the reactor vessel, whereby the reactor gas is contained while ash is permitted to continuously flow from the ash hopper's output port, impelled by gravity. The main novelty resides in the use of a control chamber to so control pressure under the lockhopper that gases will not exit from the reactor vessel, and to also regulate the ash flow rate. There is also novelty in the design of the ash lockhopper shown in two figures. The novelty there is the use of annular passages of progressively greater diameter, and rotating the center parts on a shaft, with the center part of each slightly offset from adjacent ones to better assure ash flow through the opening.

49 CFR 179.100 - General specifications applicable to pressure tank car tanks.

Code of Federal Regulations, 2014 CFR

2014-10-01

... car tanks. 179.100 Section 179.100 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120...

49 CFR 179.102 - Special commodity requirements for pressure tank car tanks.

Code of Federal Regulations, 2014 CFR

2014-10-01

... car tanks. 179.102 Section 179.102 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120...

46 CFR 54.01-1 - Incorporation by reference.

Code of Federal Regulations, 2013 CFR

2013-10-01

...://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html. The material is also... of Mechanical Engineers (ASME) International, Three Park Avenue, New York, NY 10016-5990: (1) ASME Boiler and Pressure Vessel Code, Section VIII, Division 1, Rules for Construction of Pressure Vessels...

46 CFR 54.01-1 - Incorporation by reference.

Code of Federal Regulations, 2014 CFR

2014-10-01

...://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html. The material is also... of Mechanical Engineers (ASME) International, Three Park Avenue, New York, NY 10016-5990: (1) ASME Boiler and Pressure Vessel Code, Section VIII, Division 1, Rules for Construction of Pressure Vessels...

Hierarchical Synthesis of Coastal Ecosystem Health Indicators at Karimunjawa National Marine Park

NASA Astrophysics Data System (ADS)

Danu Prasetya, Johan; Ambariyanto; Supriharyono; Purwanti, Frida

2018-02-01

The coastal ecosystem of Karimunjawa National Marine Park (KNMP) is facing various pressures, including from human activity. Monitoring the health condition of coastal ecosystems periodically is needed as an evaluation of the ecosystem condition. Systematic and consistent indicators are needed in monitoring of coastal ecosystem health. This paper presents hierarchical synthesis of coastal ecosystem health indicators using Analytic Hierarchy Process (AHP) method. Hierarchical synthesis is obtained from process of weighting by paired comparison based on expert judgments. The variables of coastal ecosystem health indicators in this synthesis consist of 3 level of variable, i.e. main variable, sub-variable and operational variable. As a result of assessment, coastal ecosystem health indicators consist of 3 main variables, i.e. State of Ecosystem, Pressure and Management. Main variables State of Ecosystem and Management obtain the same value i.e. 0.400, while Pressure value was 0.200. Each main variable consist of several sub-variable, i.e. coral reef, reef fish, mangrove and seagrass for State of Ecosystem; fisheries and marine tourism activity for Pressure; planning and regulation, institutional and also infrastructure and financing for Management. The highest value of sub-variable of main variable State of Ecosystem, Pressure and Management were coral reef (0.186); marine tourism pressure (0.133) and institutional (0.171), respectively. The highest value of operational variable of main variable State of Ecosystem, Pressure and Management were percent of coral cover (0.058), marine tourism pressure (0.133) and presence of zonation plan, regulation also socialization of monitoring program (0.53), respectively. Potential pressure from marine tourism activity is the variable that most affect the health of the ecosystem. The results of this research suggest that there is a need to develop stronger conservation strategies to facing with pressures from marine tourism activities.

Gender differences in pressure-natriuresis and renal autoregulation: role of the Angiotensin type 2 receptor.

PubMed

Hilliard, Lucinda M; Nematbakhsh, Mehdi; Kett, Michelle M; Teichman, Elleesha; Sampson, Amanda K; Widdop, Robert E; Evans, Roger G; Denton, Kate M

2011-02-01

Sexual dimorphism in arterial pressure regulation has been observed in humans and animal models. The mechanisms underlying this gender difference are not fully known. Previous studies in rats have shown that females excrete more salt than males at a similar arterial pressure. The renin-angiotensin system is a powerful regulator of arterial pressure and body fluid volume. This study examined the role of the angiotensin type 2 receptor (AT₂R) in pressure-natriuresis in male and female rats because AT₂R expression has been reported to be enhanced in females. Renal function was examined at renal perfusion pressures of 120, 100, and 80 mm Hg in vehicle-treated and AT₂R antagonist-treated (PD123319; 1 mg/kg/h) groups. The pressure-natriuresis relationship was gender-dependent such that it was shifted upward in female vs male rats (P < 0.001). AT₂R blockade modulated the pressure-natriuresis relationship, shifting the curve downward in male (P < 0.01) and female (P < 0.01) rats to a similar extent. In females, AT₂R blockade also reduced the lower end of the autoregulatory range of renal blood flow (P < 0.05) and glomerular filtration rate (P < 0.01). Subsequently, the renal blood flow response to graded angiotensin II infusion was also measured with and without AT₂R blockade. We found that AT₂R blockade enhanced the renal vasoconstrictor response to angiotensin II in females but not in males (P < 0.05). In conclusion, the AT₂R modulates pressure-natriuresis, allowing the same level of sodium to be excreted at a lower pressure in both genders. However, a gender-specific role for the AT₂R in renal autoregulation was evident in females, which may be a direct vascular AT₂R effect.

RBFox1-mediated RNA splicing regulates cardiac hypertrophy and heart failure.

PubMed

Gao, Chen; Ren, Shuxun; Lee, Jae-Hyung; Qiu, Jinsong; Chapski, Douglas J; Rau, Christoph D; Zhou, Yu; Abdellatif, Maha; Nakano, Astushi; Vondriska, Thomas M; Xiao, Xinshu; Fu, Xiang-Dong; Chen, Jau-Nian; Wang, Yibin

2016-01-01

RNA splicing is a major contributor to total transcriptome complexity; however, the functional role and regulation of splicing in heart failure remain poorly understood. Here, we used a total transcriptome profiling and bioinformatic analysis approach and identified a muscle-specific isoform of an RNA splicing regulator, RBFox1 (also known as A2BP1), as a prominent regulator of alternative RNA splicing during heart failure. Evaluation of developing murine and zebrafish hearts revealed that RBFox1 is induced during postnatal cardiac maturation. However, we found that RBFox1 is markedly diminished in failing human and mouse hearts. In a mouse model, RBFox1 deficiency in the heart promoted pressure overload-induced heart failure. We determined that RBFox1 is a potent regulator of RNA splicing and is required for a conserved splicing process of transcription factor MEF2 family members that yields different MEF2 isoforms with differential effects on cardiac hypertrophic gene expression. Finally, induction of RBFox1 expression in murine pressure overload models substantially attenuated cardiac hypertrophy and pathological manifestations. Together, this study identifies regulation of RNA splicing by RBFox1 as an important player in transcriptome reprogramming during heart failure that influence pathogenesis of the disease.

RBFox1-mediated RNA splicing regulates cardiac hypertrophy and heart failure

PubMed Central

Gao, Chen; Ren, Shuxun; Lee, Jae-Hyung; Qiu, Jinsong; Chapski, Douglas J.; Rau, Christoph D.; Zhou, Yu; Abdellatif, Maha; Nakano, Astushi; Vondriska, Thomas M.; Xiao, Xinshu; Fu, Xiang-Dong; Chen, Jau-Nian; Wang, Yibin

2015-01-01

RNA splicing is a major contributor to total transcriptome complexity; however, the functional role and regulation of splicing in heart failure remain poorly understood. Here, we used a total transcriptome profiling and bioinformatic analysis approach and identified a muscle-specific isoform of an RNA splicing regulator, RBFox1 (also known as A2BP1), as a prominent regulator of alternative RNA splicing during heart failure. Evaluation of developing murine and zebrafish hearts revealed that RBFox1 is induced during postnatal cardiac maturation. However, we found that RBFox1 is markedly diminished in failing human and mouse hearts. In a mouse model, RBFox1 deficiency in the heart promoted pressure overload–induced heart failure. We determined that RBFox1 is a potent regulator of RNA splicing and is required for a conserved splicing process of transcription factor MEF2 family members that yields different MEF2 isoforms with differential effects on cardiac hypertrophic gene expression. Finally, induction of RBFox1 expression in murine pressure overload models substantially attenuated cardiac hypertrophy and pathological manifestations. Together, this study identifies regulation of RNA splicing by RBFox1 as an important player in transcriptome reprogramming during heart failure that influence pathogenesis of the disease. PMID:26619120

Plant 14-3-3 proteins assist ion channels and pumps.

PubMed

de Boer, A H

2002-08-01

Turgor pressure is a cellular parameter, important for a range of physiological processes in plants, like cell elongation, gas exchange and gravitropic/phototropic bending. Regulation of turgor pressure involves ion and water transport at the expense of metabolic energy (ATP). The primary pump in the plasma membrane (the H(+)-ATPase) is a key player in turgor regulation since it provides the driving force for ion uptake, followed by water influx through osmosis. Using the phytotoxin fusicoccin (a well-known activator of the ATPase) as a tool, 14-3-3 proteins were identified as regulators of the H(+)-ATPase. Since fusicoccin has a dramatic effect on K(+) accumulation and cellular respiration as well, we studied whether 14-3-3 proteins play a role in the regulation of the mitochondrial F(0)F(1)-ATP synthase and ion channels in the vacuolar and plasma membranes. Besides the plasma membrane H(+)-ATPase, we have identified thus far at least four other transport proteins that are regulated by 14-3-3 proteins. The mechanism of regulation will be described and the possibility that 14-3-3 proteins act as coordinators of ion transporters with varied but interdependent functions will be discussed.

Neonatal Treatment with Antiserum to Prolactin Lowers Blood Pressure in Rats

NASA Astrophysics Data System (ADS)

Mills, David E.; Buckman, Maire T.; Peake, Glenn T.

1982-07-01

Prolactin administration reportedly increases blood pressure in rats and rabbits. To study the effects of prolactiin deficiency on blood pressure, rats were given saline, normal rabbit serum, or rabbit antiserum to rat prolactin on postnatal days 2 to 5. Both males and females given antiserum had significantly lower blood pressure at 14 weeks than rats given saline or normal rabbit serum. Blood pressure differences between females given antiserum and females given saline disappeared during and following pregnancy. The antiserum also lowered the concentration of prolactin in plasma 49 percent in males and decreased the prolactin response to ether stress in both sexes. These results suggest that endogenous prolactin is involved in blood pressure regulation.

Ablation of the GNB3 gene in mice does not affect body weight, metabolism or blood pressure, but causes bradycardia

PubMed Central

Ye, Yuanchao; Sun, Zhizeng; Guo, Ang; Song, Long-sheng; Grobe, Justin L.; Chen, Songhai

2014-01-01

G protein β3 (Gβ3) is an isoform of heterotrimeric G protein β subunits involved in transducing G protein coupled receptor (GPCR) signaling. Polymorphisms in Gβ3 (GNB3) are associated with many human disorders (e.g. hypertension, diabetes and obesity) but the role of GNB3 in these pathogeneses remains unclear. Here, Gβ3-null mice (GNB3−/−) were characterized to determine how Gβ3 functions to regulate blood pressure, body weight and metabolism. We found Gβ3 expression restricted to limited types of tissues, including the retina, several regions of brain and heart ventricles. Gβ3-deficient mice were normal as judged by body weight gain by age or by feeding with high-fat diet (HFD); glucose tolerance and insulin sensitivity; baseline blood pressure and angiotensin II infusion-induced hypertension. During tail-cuff blood pressure measurements, however, Gβ3-null mice had slower heart rates (~450 vs ~500 beats/min). This bradycardia was not observed in isolated and perfused Gβ3-null mouse hearts. Moreover, mouse hearts isolated from GNB3−/− and controls responded equivalently to muscarinic receptor- and β-adrenergic receptor-stimulated bradycardia and tachycardia, respectively. Since no difference was seen in isolated hearts, Gβ3 is unlikely to be involved directly in the GPCR signaling activity that controls heart pacemaker activity. These results demonstrate that although Gβ3 appears dispensable in mice for regulation of blood pressure, body weight and metabolic features associated with obesity and diabetes, Gβ3 may regulate heart rate. PMID:25093805

49 CFR 179.100-6 - Thickness of plates.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS SPECIFICATIONS FOR TANK CARS Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.100-6 Thickness of...

49 CFR 179.200-8 - Tank heads.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS SPECIFICATIONS FOR TANK CARS Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.200-8 Tank heads. (a) All...

49 CFR 179.200-3 - Type.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS SPECIFICATIONS FOR TANK CARS Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.200-3 Type. Tank built under these...

49 CFR 179.103-2 - Manway cover.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS SPECIFICATIONS FOR TANK CARS Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.103-2 Manway cover. (a...

49 CFR 179.200-14 - Expansion capacity.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS SPECIFICATIONS FOR TANK CARS Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.200-14 Expansion capacity. (a...

49 CFR 179.100-3 - Type.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS SPECIFICATIONS FOR TANK CARS Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.100-3 Type. (a) Tanks built under...

49 CFR 179.201-9 - Gauging device.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS SPECIFICATIONS FOR TANK CARS Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.201-9 Gauging device. A...

Low-cost feedback-controlled syringe pressure pumps for microfluidics applications.

PubMed

Lake, John R; Heyde, Keith C; Ruder, Warren C

2017-01-01

Microfluidics are widely used in research ranging from bioengineering and biomedical disciplines to chemistry and nanotechnology. As such, there are a large number of options for the devices used to drive and control flow through microfluidic channels. Commercially available syringe pumps are probably the most commonly used instruments for this purpose, but are relatively high-cost and have inherent limitations due to their flow profiles when they are run open-loop. Here, we present a low-cost ($110) syringe pressure pump that uses feedback control to regulate the pressure into microfluidic chips. Using an open-source microcontroller board (Arduino), we demonstrate an easily operated and programmable syringe pump that can be run using either a PID or bang-bang control method. Through feedback control of the pressure at the inlets of two microfluidic geometries, we have shown stability of our device to within ±1% of the set point using a PID control method and within ±5% of the set point using a bang-bang control method with response times of less than 1 second. This device offers a low-cost option to drive and control well-regulated pressure-driven flow through microfluidic chips.

Low-cost feedback-controlled syringe pressure pumps for microfluidics applications

PubMed Central

Lake, John R.; Heyde, Keith C.

2017-01-01

Microfluidics are widely used in research ranging from bioengineering and biomedical disciplines to chemistry and nanotechnology. As such, there are a large number of options for the devices used to drive and control flow through microfluidic channels. Commercially available syringe pumps are probably the most commonly used instruments for this purpose, but are relatively high-cost and have inherent limitations due to their flow profiles when they are run open-loop. Here, we present a low-cost ($110) syringe pressure pump that uses feedback control to regulate the pressure into microfluidic chips. Using an open-source microcontroller board (Arduino), we demonstrate an easily operated and programmable syringe pump that can be run using either a PID or bang-bang control method. Through feedback control of the pressure at the inlets of two microfluidic geometries, we have shown stability of our device to within ±1% of the set point using a PID control method and within ±5% of the set point using a bang-bang control method with response times of less than 1 second. This device offers a low-cost option to drive and control well-regulated pressure-driven flow through microfluidic chips. PMID:28369134

Management methodology for pressure equipment

NASA Astrophysics Data System (ADS)

Bletchly, P. J.

Pressure equipment constitutes a significant investment in capital and a major proportion of potential high-risk plant in many operations and this is particularly so in an alumina refinery. In many jurisdictions pressure equipment is also subject to statutory regulation that imposes obligations on Owners of the equipment with respect to workplace safety. Most modern technical standards and industry codes of practice employ a risk-based approach to support better decision making with respect to pressure equipment. For a management system to be effective it must demonstrate that risk is being managed within acceptable limits.

The Analysis for Regulation Performance of a Variable Thrust Rocket Engine Control System,

DTIC Science & Technology

1982-06-29

valve: Q,- K .W(t).±K.APN(t) (14) where (15) K-KK (16) ( 17 ) (18) Equations (13) and (14) can be expressed as one equation: . Q(t)-QCt)-Qa(t)-n(" -K:)EQ...Hydraulic pressure when the needle valve starts to rise [g/mm 2 4PH (t)-Hydraulic pressure increment 2 AHHydraulic pressure function area (mm2 B-Needle...rate gain Ke and solenoid valve pressure coefficient K use relatedPH equations (15), (16), ( 17 ) and (18). If we use the parameters of * the exhaust

Cardiovascular regulation in humans in response to oscillatory lower body negative pressure

NASA Technical Reports Server (NTRS)

Levenhagen, D. K.; Evans, J. M.; Wang, M.; Knapp, C. F.

1994-01-01

The frequency response characteristics of human cardiovascular regulation during hypotensive stress have not been determined. We therefore exposed 10 male volunteers to seven frequencies (0.004-0.1 Hz) of oscillatory lower body negative pressure (OLBNP; 0-50 mmHg). Fourier spectra of arterial pressure (AP), central venous pressure (CVP), stroke volume (SV), cardiac output (CO), heart rate (HR), and total peripheral resistance (TPR) were determined and first harmonic mean, amplitude, and phase angles with respect to OLBNP are presented. AP was relatively well regulated as demonstrated by small oscillations in half amplitude (3.5 mmHg) that were independent of OLBNP frequency and similar to unstressed control spectra. Due to the biomechanics of the system, the magnitudes of oscillations in calf circumference (CC) and CVP decreased with increasing frequency; therefore, we normalized responses by these indexes of the fluid volume shifted. The ratios of oscillations in AP to oscillations in CC increased by an order of magnitude, whereas oscillations in CVP to oscillations in CC and oscillations in AP to oscillations in CVP both tripled between 0.004 and 0.1 Hz. Therefore, even though the amount of fluid shifted by OLBNP decreased with increasing frequency, the magnitude of both CVP and AP oscillations per volume of fluid shifted increased (peaking at 0.08 Hz). The phase relationships between variables, particularly the increasing lags in SV and TPR, but not CVP, indicated that efferent responses with lags of 5-6 s could account for the observed responses. We conclude that, at frequencies below 0.02 Hz, the neural system of humans functioned optimally in regulating AP; OLBNP-induced decreases in SV (by as much as 50%) were counteracted by appropriate oscillations in HR and TPR responses. As OLBNP frequency increased, SV, TPR, and HR oscillations increasingly lagged the input and became less optimally timed for AP regulation.

Cardiovascular regulation during sleep quantified by symbolic coupling traces

NASA Astrophysics Data System (ADS)

Suhrbier, A.; Riedl, M.; Malberg, H.; Penzel, T.; Bretthauer, G.; Kurths, J.; Wessel, N.

2010-12-01

Sleep is a complex regulated process with short periods of wakefulness and different sleep stages. These sleep stages modulate autonomous functions such as blood pressure and heart rate. The method of symbolic coupling traces (SCT) is used to analyze and quantify time-delayed coupling of these measurements during different sleep stages. The symbolic coupling traces, defined as the symmetric and diametric traces of the bivariate word distribution matrix, allow the quantification of time-delayed coupling. In this paper, the method is applied to heart rate and systolic blood pressure time series during different sleep stages for healthy controls as well as for normotensive and hypertensive patients with sleep apneas. Using the SCT, significant different cardiovascular mechanisms not only between the deep sleep and the other sleep stages but also between healthy subjects and patients can be revealed. The SCT method is applied to model systems, compared with established methods, such as cross correlation, mutual information, and cross recurrence analysis and demonstrates its advantages especially for nonstationary physiological data. As a result, SCT proves to be more specific in detecting delays of directional interactions than standard coupling analysis methods and yields additional information which cannot be measured by standard parameters of heart rate and blood pressure variability. The proposed method may help to indicate the pathological changes in cardiovascular regulation and also the effects of continuous positive airway pressure therapy on the cardiovascular system.

49 CFR 192.620 - Alternative maximum allowable operating pressure for certain steel pipelines.

Code of Federal Regulations, 2014 CFR

2014-10-01

... for certain steel pipelines. 192.620 Section 192.620 Transportation Other Regulations Relating to... STANDARDS Operations § 192.620 Alternative maximum allowable operating pressure for certain steel pipelines..., 2, or 3 location; (2) The pipeline segment is constructed of steel pipe meeting the additional...

49 CFR 179.200 - General specifications applicable to non-pressure tank car tanks (Class DOT-111).

Code of Federal Regulations, 2013 CFR

2013-10-01

... tank car tanks (Class DOT-111). 179.200 Section 179.200 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW...

49 CFR 179.200 - General specifications applicable to non-pressure tank car tanks (Class DOT-111).

Code of Federal Regulations, 2014 CFR

2014-10-01

... tank car tanks (Class DOT-111). 179.200 Section 179.200 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW...

40 CFR 65.117 - Alternative means of emission limitation: Batch processes.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) AIR PROGRAMS (CONTINUED) CONSOLIDATED FEDERAL AIR RULE Equipment Leaks § 65.117 Alternative means... section provide the options of pressure testing or monitoring the equipment for leaks. The owner or... pressure-tested for leaks before regulated material is first fed to the equipment and the equipment is...

40 CFR 1065.659 - Removed water correction.

Code of Federal Regulations, 2011 CFR

2011-07-01

... know that saturated water vapor conditions exist. Use good engineering judgment to measure the... absolute pressure based on an alarm set point, a pressure regulator set point, or good engineering judgment... from raw exhaust, you may determine the amount of water based on intake-air humidity, plus a chemical...

40 CFR 1065.659 - Removed water correction.

Code of Federal Regulations, 2010 CFR

2010-07-01

... know that saturated water vapor conditions exist. Use good engineering judgment to measure the... absolute pressure based on an alarm set point, a pressure regulator set point, or good engineering judgment... from raw exhaust, you may determine the amount of water based on intake-air humidity, plus a chemical...

46 CFR 167.25-1 - Boilers, pressure vessels, piping and appurtenances.

Code of Federal Regulations, 2014 CFR

2014-10-01

... SCHOOLS PUBLIC NAUTICAL SCHOOL SHIPS Marine Engineering § 167.25-1 Boilers, pressure vessels, piping and... engineering regulations in parts 50 to 63, inclusive, of Subchapter F (Marine Engineering) of this chapter. (2... part 52 of Subchapter F (Marine Engineering) of this chapter. All alterations, replacements or repairs...

46 CFR 167.25-1 - Boilers, pressure vessels, piping and appurtenances.

Code of Federal Regulations, 2010 CFR

2010-10-01

... SCHOOLS PUBLIC NAUTICAL SCHOOL SHIPS Marine Engineering § 167.25-1 Boilers, pressure vessels, piping and... engineering regulations in parts 50 to 63, inclusive, of Subchapter F (Marine Engineering) of this chapter. (2... part 52 of Subchapter F (Marine Engineering) of this chapter. All alterations, replacements or repairs...

49 CFR 192.191 - Design pressure of plastic fittings.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 3 2011-10-01 2011-10-01 false Design pressure of plastic fittings. 192.191 Section 192.191 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE:...

49 CFR 192.191 - Design pressure of plastic fittings.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 3 2013-10-01 2013-10-01 false Design pressure of plastic fittings. 192.191 Section 192.191 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE:...

49 CFR 192.199 - Requirements for design of pressure relief and limiting devices.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 3 2011-10-01 2011-10-01 false Requirements for design of pressure relief and limiting devices. 192.199 Section 192.199 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF NATURAL...

49 CFR 192.199 - Requirements for design of pressure relief and limiting devices.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 3 2013-10-01 2013-10-01 false Requirements for design of pressure relief and limiting devices. 192.199 Section 192.199 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF NATURAL...

Back-pressure Effect on Shock-Train Location in a Scramjet Engine Isolator

DTIC Science & Technology

2010-03-01

valves .......................................................................................... 57 Side project: making an actuator stand...21 Figure 8. Main manual shut off valve ...................................................................................22 Figure 9 . A small...characteristic about this wind tunnel. With Mach 1.8 nozzle, prior to test runs, the upstream regulator pressure valve (Figure 9 ) was set at

Gender Equity, Sport Sponsorship, and Participation

ERIC Educational Resources Information Center

Yiamouyiannis, Athena

2009-01-01

As the pressure to win in select collegiate sports escalates, financial pressures mount, and the need to comply with Title IX regulations and gender equity policies continues, athletics administrators are faced with having to make difficult decisions regarding their sport programs. To assist in the decision-making process regarding sport programs,…

The influence of central command on baroreflex resetting during exercise

NASA Technical Reports Server (NTRS)

Raven, Peter B.; Fadel, Paul J.; Smith, Scott A.

2002-01-01

The arterial baroreflex functions as a negative feedback system regulating blood pressure around an established operating point. Paradoxically, a parallel increase in heart rate and blood pressure manifests during exercise. Experimental evidence suggests these events are caused, in part, by a rapid resetting of the baroreflex by central command.

16 CFR 1500.45 - Method for determining extremely flammable and flammable contents of self-pressurized containers.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Method for determining extremely flammable and flammable contents of self-pressurized containers. 1500.45 Section 1500.45 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS HAZARDOUS SUBSTANCES AND...

Exploring the intricate regulatory network controlling the thiazide-sensitive NaCl cotransporter (NCC).

PubMed

Dimke, Henrik

2011-12-01

The thiazide-sensitive NaCl cotransporter (NCC) plays key roles in renal electrolyte transport and blood pressure maintenance. Regulation of this cotransporter has received increased attention recently, prompted by the discovery that mutations in the with-no-lysine (WNK) kinases are the molecular explanation for pseudohypoaldosteronism type II (PHAII). Studies suggest that WNK4 regulates NCC via two distinct pathways, depending on its state of activation. Furthermore, an intact STE20-related proline-alanine-rich kinase (SPAK)/oxidative stress response 1 kinase (OSR1) pathway was found to be necessary for a WNK4 PHAII mutation to increase NCC phosphorylation and blood pressure in mice. The mouse protein 25α is a novel regulator of the SPAK/OSR1 kinase family, which greatly increases their activity. The phosphorylation status of NCC and the WNK is regulated by the serum- and glucocorticoid-inducible kinase 1, suggesting novel mechanisms whereby aldosterone modulates NCC activity. Dephosphorylation of NCC by protein phosphatase 4 strongly influences the activity of the cotransporter, confirming an important role for NCC phosphorylation. Finally, γ-adducin increases NCC activity. This stimulatory effect is dependent on the phosphorylation status of the cotransporter. γ-Adducin only binds the dephosphorylated cotransporter, suggesting that phosphorylation of NCC causes the dissociation of γ-adducin. Since γ-adducin is not a kinase, it is tempting to speculate that the protein exerts its function by acting as a scaffold between the dephosphorylated cotransporter and the regulatory kinase. As more molecular regulators of NCC are identified, the system-controlling NCC activity is becoming increasingly complex. This intricacy confers an ability to integrate a variety of stimuli, thereby regulating NCC transport activity and ultimately blood pressure.

New trends in chemistry and materials science in extremely tight space

DOE PAGES

Song, Yang; Manaa, M. Riad

2012-01-26

Pressure plays a critical role in regulating the structures and properties of materials. Since Percy Bridgeman was recognized by the 1946 Nobel Prize in Physics for his contribution in high-pressure physics, high-pressure research has remained an interdisciplinary scientific frontier with many extraordinary breakthroughs. Over the past decade or so, in particular, high-pressure chemistry and materials research has undergone major advances with the discovery of numerous exotic structures and properties. Furthermore, brand new classes of inorganic materials of unusual stoichiometries and crystal structures, which have a wide range of optical, mechanical, electronic and magnetic properties, have been produced at high pressures.

New trends in chemistry and materials science in extremely tight space

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, Yang; Manaa, M. Riad

Pressure plays a critical role in regulating the structures and properties of materials. Since Percy Bridgeman was recognized by the 1946 Nobel Prize in Physics for his contribution in high-pressure physics, high-pressure research has remained an interdisciplinary scientific frontier with many extraordinary breakthroughs. Over the past decade or so, in particular, high-pressure chemistry and materials research has undergone major advances with the discovery of numerous exotic structures and properties. Furthermore, brand new classes of inorganic materials of unusual stoichiometries and crystal structures, which have a wide range of optical, mechanical, electronic and magnetic properties, have been produced at high pressures.

Enterprise-Level Motivations, Regulatory Pressures, and Corporate Environmental Management in Guangzhou, China

NASA Astrophysics Data System (ADS)

Tang, Shui-Yan; Li, Pansy Honying; Fryxell, Gerald E.; Lo, Carlos Wing-Hung

2015-09-01

This study examines the effects of internal motivations and external pressures on the integration of environmental management (EM) practices within manufacturing operations in China. The moderating role of perceptions toward the regulatory process is also considered along with comparisons between wholly Chinese-owned and foreign-owned enterprises. From a sample of 131 manufacturing companies in the Guangzhou area, it was found that the salience of fees and fines has a strong positive influence on perceptions toward the regulator (the local Environmental Protection Bureau, EPB). This also has a positive effect on perceptions toward regulations themselves for foreign-owned enterprises. Business-case motivations for EM positively shape enterprise perceptions toward regulations, whereas risk-reduction motivations have a negative effect on perceptions toward regulations in foreign-owned enterprises. Enterprise perceptions toward the regulatory process have direct effects on the integration of EM practices in wholly Chinese-owned enterprises, but in opposite directions. While positive perceptions toward regulations have positive influence, positive perceptions toward regulators (i.e., the EPB) negatively affect it. Overall, these results indicated that promoting the adoption of EM practices depends on convincing business leaders that EM practices contribute to profit making. The regulatory process can potentially promote these practices, but measures need to be taken to ensure that the regulator is not co-opted by the regulated, especially in wholly Chinese-owned enterprises.

Enterprise-Level Motivations, Regulatory Pressures, and Corporate Environmental Management in Guangzhou, China.

PubMed

Tang, Shui-Yan; Li, Pansy Honying; Fryxell, Gerald E; Lo, Carlos Wing-Hung

2015-09-01

This study examines the effects of internal motivations and external pressures on the integration of environmental management (EM) practices within manufacturing operations in China. The moderating role of perceptions toward the regulatory process is also considered along with comparisons between wholly Chinese-owned and foreign-owned enterprises. From a sample of 131 manufacturing companies in the Guangzhou area, it was found that the salience of fees and fines has a strong positive influence on perceptions toward the regulator (the local Environmental Protection Bureau, EPB). This also has a positive effect on perceptions toward regulations themselves for foreign-owned enterprises. Business-case motivations for EM positively shape enterprise perceptions toward regulations, whereas risk-reduction motivations have a negative effect on perceptions toward regulations in foreign-owned enterprises. Enterprise perceptions toward the regulatory process have direct effects on the integration of EM practices in wholly Chinese-owned enterprises, but in opposite directions. While positive perceptions toward regulations have positive influence, positive perceptions toward regulators (i.e., the EPB) negatively affect it. Overall, these results indicated that promoting the adoption of EM practices depends on convincing business leaders that EM practices contribute to profit making. The regulatory process can potentially promote these practices, but measures need to be taken to ensure that the regulator is not co-opted by the regulated, especially in wholly Chinese-owned enterprises.

49 CFR 179.200-6 - Thickness of plates.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS SPECIFICATIONS FOR TANK CARS Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.200-6 Thickness of plates. (a...

75 FR 19963 - Florida Gas Transmission Company, LLC; Transcontinental Gas Pipe Line Company, LLC; Florida Gas...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-16

... County, Alabama, (milepost [MP] 0.0); One new Meter and Regulation (M&R) (Grand Bay M&R Station) with pig launcher in Grand Bay, Alabama (MP 8.8); One new Over Pressure Protection Regulator Station with pig...

Role of proopiomelanocortin neuron Stat3 in regulating arterial pressure and mediating the chronic effects of leptin.

PubMed

Dubinion, John H; do Carmo, Jussara M; Adi, Ahmad; Hamza, Shereen; da Silva, Alexandre A; Hall, John E

2013-05-01

Although signal transducer and activator of transcription 3 (Stat3) is a key second messenger by which leptin regulates appetite and body weight, its role in specific neuronal populations in metabolic regulation and in mediating the chronic effects of leptin on blood pressure is unknown. The current study tested the hypothesis that Stat3 signaling in proopiomelanocortin (POMC) neurons mediates the chronic effects of leptin on mean arterial pressure (MAP), as well as on glucose regulation, energy expenditure, and food intake. Stat3(flox/flox) mice were crossed with POMC-Cre mice to generate mice with Stat3 deletion specifically in POMC neurons (Stat3(flox/flox)/POMC-Cre). Oxygen consumption (Vo2), carbon dioxide respiration (Vco2), motor activity, heat production, food intake, and MAP were measured 24 hours/d. After baseline measurements, leptin was infused (4 μg/kg per min, IP) for 7 days. Stat3(flox/flox)/POMC-Cre mice were hyperphagic, heavier, and had increased respiratory quotients compared with control Stat3(flox/flox) mice. Baseline MAP was not different between the groups, and chronic leptin infusion reduced food intake similarly in both groups (27 versus 29%). Vo2, Vco2, and heat production responses to leptin were not significantly different in control and Stat3(flox/flox)/POMC-Cre mice. However, leptin-mediated increases in MAP were completely abolished, and blood pressure responses to acute air-jet stress were attenuated in male Stat3(flox/flox)/POMC-Cre mice. These results indicate that Stat3 signaling in POMC neurons is essential for leptin-mediated increases in MAP, but not for anorexic or thermogenic effects of leptin.

The cardiovascular effects of a chimeric opioid peptide based on morphiceptin and PFRTic-NH2.

PubMed

Li, Meixing; Zhou, Lanxia; Ma, Guoning; Cao, Shuo; Dong, Shouliang

2013-01-01

MCRT (YPFPFRTic-NH(2)) is a chimeric opioid peptide based on morphiceptin and PFRTic-NH(2). In order to assess the cardiovascular effect of MCRT, it was administered by intravenous (i.v.) injection targeting at the peripheral nervous system and by intracerebroventricular (i.c.v.) injection targeting at the central nervous system. Naloxone and L-NAME were injected before MCRT to investigate possible interactions with MCRT. Results show that administration of MCRT by i.v. or i.c.v. injection could induce bradycardia and decrease in mean arterial pressure (MAP) at a greater degree than that with morphiceptin and PFRTic-NH(2). When MCRT and NPFF were coinjected, we observed a dose-dependent weakening of these cardiovascular effects by MCRT. Because naloxone completely abolished the cardiovascular effects of MCRT, we conclude that opioid receptors are involved in regulating the MAP of MCRT regardless of modes of injection. The effect of MCRT on heart rate is completely dependent on opioid receptors when MCRT was administered by i.c.v. instead of i.v. The central nitric oxide (NO) pathway is involved in regulating blood pressure by MCRT under both modes of injection, but the peripheral NO pathway had no effect on lowering blood pressure mediated by MCRT when it was administered by i.c.v. Based on the results from different modes of injection, the regulation of heart rate by MCRT mainly involves in the central NO pathway. Lastly, we observed that the cardiovascular effects of MCRT such as bradycardia and decrease of blood pressure, were stronger than that of its parent peptides. Opioid receptors and the NO pathway are involved in the cardiovascular regulation by MCRT, and their degree of involvement differs between intravenous and intracerebroventricular injection. Copyright © 2012 Elsevier Inc. All rights reserved.

The critical role of the central nervous system (pro)renin receptor in regulating systemic blood pressure

PubMed Central

Xu, Quanbin; Jensen, Dane D.; Peng, Hua; Feng, Yumei

2016-01-01

The systemic renin–angiotensin system (RAS) has long been recognized as a critically important system in blood pressure (BP) regulation. However, extensive evidence has shown that a majority of RAS components are also present in many tissues and play indispensable roles in BP regulation. Here, we review evidence that RAS components, notably including the newly identified (pro)renin receptor (PRR), are present in the brain and are essential for the central regulation of BP. Binding of the PRR to its ligand, prorenin or renin, increases BP and promotes progression of cardiovascular diseases in an angiotensin II-dependent and -independent manner, establishing the PRR a promising antihypertensive drug target. We also review the existing PRR blockers, including handle region peptide and PRO20, and propose a rationale for blocking prorenin/PRR activation as a therapeutic approach that does not affect the actions of the PRR in vacuolar H+-ATPase and development. Finally, we summarize categories of currently available antihypertensive drugs and consider future perspectives. PMID:27113409

Non-site-specific allosteric effect of oxygen on human hemoglobin under high oxygen partial pressure

PubMed Central

Takayanagi, Masayoshi; Kurisaki, Ikuo; Nagaoka, Masataka

2014-01-01

Protein allostery is essential for vital activities. Allosteric regulation of human hemoglobin (HbA) with two quaternary states T and R has been a paradigm of allosteric structural regulation of proteins. It is widely accepted that oxygen molecules (O2) act as a “site-specific” homotropic effector, or the successive O2 binding to the heme brings about the quaternary regulation. However, here we show that the site-specific allosteric effect is not necessarily only a unique mechanism of O2 allostery. Our simulation results revealed that the solution environment of high O2 partial pressure enhances the quaternary change from T to R without binding to the heme, suggesting an additional “non-site-specific” allosteric effect of O2. The latter effect should play a complementary role in the quaternary change by affecting the intersubunit contacts. This analysis must become a milestone in comprehensive understanding of the allosteric regulation of HbA from the molecular point of view. PMID:24710521

Non-site-specific allosteric effect of oxygen on human hemoglobin under high oxygen partial pressure.

PubMed

Takayanagi, Masayoshi; Kurisaki, Ikuo; Nagaoka, Masataka

2014-04-08

Protein allostery is essential for vital activities. Allosteric regulation of human hemoglobin (HbA) with two quaternary states T and R has been a paradigm of allosteric structural regulation of proteins. It is widely accepted that oxygen molecules (O2) act as a "site-specific" homotropic effector, or the successive O2 binding to the heme brings about the quaternary regulation. However, here we show that the site-specific allosteric effect is not necessarily only a unique mechanism of O2 allostery. Our simulation results revealed that the solution environment of high O2 partial pressure enhances the quaternary change from T to R without binding to the heme, suggesting an additional "non-site-specific" allosteric effect of O2. The latter effect should play a complementary role in the quaternary change by affecting the intersubunit contacts. This analysis must become a milestone in comprehensive understanding of the allosteric regulation of HbA from the molecular point of view.

Parasitic load control system for exhaust temperature control

DOEpatents

Strauser, Aaron D.; Coleman, Gerald N.; Coldren, Dana R.

2009-04-28

A parasitic load control system is provided. The system may include an exhaust producing engine and a fuel pumping mechanism configured to pressurize fuel in a pressure chamber. The system may also include an injection valve configured to cause fuel pressure to build within the pressure chamber when in a first position and allow injection of fuel from the pressure chamber into one or more combustion chambers of the engine when in a second position. The system may further include a controller configured to independently regulate the pressure in the pressure chamber and the injection of fuel into the one or more combustion chambers, to increase a load on the fuel pumping mechanism, increasing parasitic load on the engine, thereby increasing a temperature of the exhaust produced by the engine.

Beat-to-beat blood pressure analysis after premature ventricular contraction indicates sensitive baroreceptor dysfunction in Parkinson's disease.

PubMed

Haensch, Carl-Albrecht; Jörg, Johannes

2006-04-01

Extrasystoles occur in normal subjects but are significant more frequently (16.25% vs. 55%; chi(2) = 19.3; P < 0.001) seen in Parkinson's disease (PD) patients. The extrasystolic decreases in stroke volume and systolic pressure activate sympathetic vasomotor innervation and lead to a blood pressure increase for a few heartbeats. The purpose of this study was to prove whether the short time analysis of this blood pressure regulation allows the assessment of sympathetic neurocirculatory function. Records of noninvasive blood pressure monitoring were reviewed from 40 PD patients and 80 controls. A battery of cardiovascular autonomic tests, including Valsalva maneuver, tilt-table testing, echocardiography, and cardiac scintigraphy with [(123)I]meta-iodobenzylguanidine were performed. Fifty-five percent of the PD patients had at least one premature ventricular contraction (PVC) in 10 minutes lying supine at rest. After every PVC (13 PVCs) recorded from normal subjects, we found an increase in systolic blood pressure above base line with a maximum at the seventh heart beat. In all of the 22 PD patients, the systolic blood pressure was significantly decreased less than baseline in every PVC from the second to the ninth postextrasystolic beat (P < 0.001). In both groups, the extrasystolic fall in blood pressure was on average approximately 22%. The postextrasystolic potentiation did not differ (5.3% vs. 4.4%, not significant). If a PVC occurs, the analysis of short-time blood pressure regulation is a sensitive tool for baroreceptor reflex function. The advantage of this method results from the independence of patients cooperation and the high sensitivity to prove a sympathetic neurocirculatory failure within 10 heart beats. Copyright 2005 Movement Disorder Society.

Desoxycorticosterone pivalate-salt treatment leads to non-dipping hypertension in Per1 knockout mice.

PubMed

Solocinski, K; Holzworth, M; Wen, X; Cheng, K-Y; Lynch, I J; Cain, B D; Wingo, C S; Gumz, M L

2017-05-01

Increasing evidence demonstrates that circadian clock proteins are important regulators of physiological functions including blood pressure. An established risk factor for developing cardiovascular disease is the absence of a blood pressure dip during the inactive period. The goal of the present study was to determine the effects of a high salt diet plus mineralocorticoid on PER1-mediated blood pressure regulation in a salt-resistant, normotensive mouse model, C57BL/6J. Blood pressure was measured using radiotelemetry. After control diet, wild-type (WT) and Per1 (KO) knockout mice were given a high salt diet (4% NaCl) and the long-acting mineralocorticoid deoxycorticosterone pivalate. Blood pressure and activity rhythms were analysed to evaluate changes over time. Blood pressure in WT mice was not affected by a high salt diet plus mineralocorticoid. In contrast, Per1 KO mice exhibited significantly increased mean arterial pressure (MAP) in response to a high salt diet plus mineralocorticoid. The inactive/active phase ratio of MAP in WT mice was unchanged by high salt plus mineralocorticoid treatment. Importantly, this treatment caused Per1 KO mice to lose the expected decrease or 'dip' in blood pressure during the inactive compared to the active phase. Loss of PER1 increased sensitivity to the high salt plus mineralocorticoid treatment. It also resulted in a non-dipper phenotype in this model of salt-sensitive hypertension and provides a unique model of non-dipping. Together, these data support an important role for the circadian clock protein PER1 in the modulation of blood pressure in a high salt/mineralocorticoid model of hypertension. © 2016 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

Role of endothelin-1 in choroidal blood flow regulation during isometric exercise in healthy humans.

PubMed

Fuchsjäger-Mayrl, Gabriele; Luksch, Alexandra; Malec, Magdalena; Polska, Elzbieta; Wolzt, Michael; Schmetterer, Leopold

2003-02-01

There is evidence that the choroid has some autoregulatory capacity in response to changes in ocular perfusion pressure (OPP). The mediators of this response are hitherto unidentified. The hypothesis for the current study was that endothelin (ET)-1 and/or angiotensin (ANF)-II may be involved in choroidal vasoconstriction during an increase in OPP. To test this hypothesis a randomized, double-masked, placebo-controlled, three way crossover study was performed in 12 healthy male volunteers. Subjects received on different study days intravenous infusions of the specific ET(A) receptor antagonist BQ-123, the angiotensin converting enzyme inhibitor enalapril or placebo. During these infusion periods subjects were asked to squat for 6 minutes. Choroidal blood flow was measured using a confocal laser Doppler flowmeter and ocular perfusion pressure (OPP) was calculated from mean arterial pressure and intraocular pressure. BQ-123 and enalapril had no effect on basal blood pressure, pulse rate, intraocular pressure, or choroidal blood flow. During isometric exercise, a pronounced increase in mean arterial pressure paralleled by an increase in OPP was observed. Although choroidal blood flow slightly increased during squatting, the increase was much less pronounced than the increase in OPP, indicating some regulatory potential of the choroid. Enalapril did not alter the choroidal pressure-flow relationship during isometric exercise, but BQ-123 induced a significant leftward shift of the pressure-flow curve (P < 0.001). The present data indicate that ET-1, but not ANG II, plays a role in choroidal blood flow regulation during isometric exercise in healthy humans. Hence, impaired choroidal autoregulation in patients with ocular vascular diseases may arise from an altered endothelin system. Further studies in such patients are warranted to verify this hypothesis.

SELF-REGULATING BOILING-WATER NUCLEAR REACTORS

DOEpatents

Ransohoff, J.A.; Plawchan, J.D.

1960-08-16

A boiling-water reactor was designed which comprises a pressure vessel containing a mass of water, a reactor core submerged within the water, a reflector tank disposed within the reactor, the reflector tank being open at the top to the interior of the pressure vessel, and a surge tank connected to the reflector tank. In operation the reflector level changes as a function of the pressure witoin the reactor so that the reactivity of the reactor is automatically controlled.

Imitative modeling automatic system Control of steam pressure in the main steam collector with the influence on the main Servomotor steam turbine

NASA Astrophysics Data System (ADS)

Andriushin, A. V.; Zverkov, V. P.; Kuzishchin, V. F.; Ryzhkov, O. S.; Sabanin, V. R.

2017-11-01

The research and setting results of steam pressure in the main steam collector “Do itself” automatic control system (ACS) with high-speed feedback on steam pressure in the turbine regulating stage are presented. The ACS setup is performed on the simulation model of the controlled object developed for this purpose with load-dependent static and dynamic characteristics and a non-linear control algorithm with pulse control of the turbine main servomotor. A method for tuning nonlinear ACS with a numerical algorithm for multiparametric optimization and a procedure for separate dynamic adjustment of control devices in a two-loop ACS are proposed and implemented. It is shown that the nonlinear ACS adjusted with the proposed method with the regulators constant parameters ensures reliable and high-quality operation without the occurrence of oscillations in the transient processes the operating range of the turbine loads.

Oxygen partial pressure modulates 67-kDa laminin receptor expression, leading to altered activity of the green tea polyphenol, EGCG.

PubMed

Tsukamoto, Shuntaro; Yamashita, Shuya; Kim, Yoon Hee; Kumazoe, Motofumi; Huang, Yuhui; Yamada, Koji; Tachibana, Hirofumi

2012-09-21

(-)-Epigallocatechin-3-O-gallate (EGCG) exhibits anti-tumor activity mediated via the 67-kDa laminin receptor (67LR). In this study, we found that 67LR protein levels are reduced by exposure to low O(2) levels (5%), without affecting the expression of HIF-1α. We also found that EGCG-induced anti-cancer activity is abrogated under low O(2) levels (5%) in various cancer cells. Notably, treatment with the proteasome inhibitor, prevented down-regulation of 67LR and restored sensitivity to EGCG under 5% O(2). In summary, 67LR expression is highly sensitive to O(2) partial pressure, and the activity of EGCG can be regulated in cancer cells by O(2) partial pressure. Copyright © 2012 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Reflex effects on renal nerve activity characteristics in spontaneously hypertensive rats.

PubMed

DiBona, G F; Jones, S Y; Sawin, L L

1997-11-01

The effects of arterial and cardiac baroreflex activation on the discharge characteristics of renal sympathetic nerve activity were evaluated in conscious spontaneously hypertensive and Wistar-Kyoto rats. In spontaneously hypertensive rats compared with Wistar-Kyoto rats, (1) arterial baroreflex regulation of renal sympathetic nerve activity was reset to a higher arterial pressure and the gain was decreased and (2) cardiac baroreflex regulation of renal sympathetic nerve activity exhibited a lower gain. With the use of sympathetic peak detection analysis, the inhibition of integrated renal sympathetic nerve activity, which occurred during both increased arterial pressure (arterial baroreflex) and right atrial pressure (cardiac baroreflex), was due to parallel decreases in peak height with little change in peak frequency in both spontaneously hypertensive and Wistar-Kyoto rats. Arterial and cardiac baroreflex inhibition of renal sympathetic nerve activity in Wistar-Kyoto and spontaneously hypertensive rats is due to a parallel reduction in the number of active renal sympathetic nerve fibers.

Gas pipeline relief valves

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bright, G.F.

1974-01-01

A discussion of the increasing activity of natural gas pipeline companies in the analysis of the overpressure protection methods for complying with the provisions of Part 192, Title 49, Code of Federal Regulations ''Transportation of Natural and Other Gas by Pipelines; Minimum Federal Safety Standards'' and with the USAS B31.8 Code covers the basic requirements for protection against accidental overpressure as being essentially the same in both documents, i.e., at the maximum allowable operating overpressure in a gas system can be exceeded either at a compressor station or downstream of a pressure control valve; mandatory use of overpressure protection devicesmore » in these situations, except for those cases which exempt some service regulators because the distribution system pressure is less than 60 psig and six other requirements of design, performance, and size are met; and basic design requirements of a pressure relief or limiting station and the components used.« less

Gene expression profiles in chondrosarcoma cells subjected to cyclic stretching and hydrostatic pressure. A cDNA array study.

PubMed

Karjalainen, Hannu M; Sironen, Reijo K; Elo, Mika A; Kaarniranta, Kai; Takigawa, Masaharu; Helminen, Heikki J; Lammi, Mikko J

2003-01-01

Mechanical forces have a profound effect on cartilage tissue and chondrocyte metabolism. Strenuous loading inhibits the cellular metabolism, while optimal level of loading at correct frequency raises an anabolic response in chondrocytes. In this study, we used Atlas Human Cancer cDNA array to investigate mRNA expression profiles in human chondrosarcoma cells stretched 8% for 6 hours at a frequency of 0.5 Hz. In addition, cultures were exposed to continuous and cyclic (0.5 Hz) 5 MPa hydrostatic pressure. Cyclic stretch had a more profound effect on the gene expression profiles than 5 MPa hydrostatic pressure. Several genes involved with the regulation of cell cycle were increased in stretched cells, as well as mRNAs for PDGF-B, glucose-1-phosphate uridylyltransferase, Tiam1, cdc37 homolog, Gem, integrin alpha6, and matrix metalloproteinase-3. Among down-regulated genes were plakoglobin, TGF-alpha, retinoic acid receptor-alpha and Wnt8b. A smaller number of changes was detected after pressure treatments. Plakoglobin was increased under cyclic and continuous 5 MPa hydrostatic pressure, while mitogen-activated protein kinase-9, proliferating cell nuclear antigen, Rad6, CD9 antigen, integrins alphaE and beta8, and vimentin were decreased. Cyclic and continuous pressurization induces a number of specific changes. In conclusion, a different set of genes were affected by three different types of mechanical stimuli applied on chondrosarcoma cells.

Gene expression profiling of a pressure-tolerant Listeria monocytogenes Scott A CtsR deletion mutant

USDA-ARS?s Scientific Manuscript database

Listeria monocytogenes is a food-borne pathogen of significant threat to public health. High hydrostatic pressure (HPP) treatment can be used to control Listeria monocytogenes in food. The CtsR (class three stress gene repressor) protein negatively regulates the expression of class III heat shock ...

49 CFR 192.229 - Limitations on welders.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY....227(a)— (1) May not weld on pipe to be operated at a pressure that produces a hoop stress of 20... pipe to be operated at a pressure that produces a hoop stress of less than 20 percent of SMYS unless...

49 CFR 192.229 - Limitations on welders.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY....227(a)— (1) May not weld on pipe to be operated at a pressure that produces a hoop stress of 20... pipe to be operated at a pressure that produces a hoop stress of less than 20 percent of SMYS unless...

49 CFR 192.229 - Limitations on welders.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY....227(a)— (1) May not weld on pipe to be operated at a pressure that produces a hoop stress of 20... pipe to be operated at a pressure that produces a hoop stress of less than 20 percent of SMYS unless...

49 CFR 192.229 - Limitations on welders.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY....227(a)— (1) May not weld on pipe to be operated at a pressure that produces a hoop stress of 20... pipe to be operated at a pressure that produces a hoop stress of less than 20 percent of SMYS unless...

49 CFR 192.229 - Limitations on welders.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY....227(a)— (1) May not weld on pipe to be operated at a pressure that produces a hoop stress of 20... pipe to be operated at a pressure that produces a hoop stress of less than 20 percent of SMYS unless...

High-cut characteristics of the baroreflex neural arc preserve baroreflex gain against pulsatile pressure.

PubMed

Kawada, Toru; Zheng, Can; Yanagiya, Yusuke; Uemura, Kazunori; Miyamoto, Tadayoshi; Inagaki, Masashi; Shishido, Toshiaki; Sugimachi, Masaru; Sunagawa, Kenji

2002-03-01

A transfer function from baroreceptor pressure input to sympathetic nerve activity (SNA) shows derivative characteristics in the frequency range below 0.8 Hz in rabbits. These derivative characteristics contribute to a quick and stable arterial pressure (AP) regulation. However, if the derivative characteristics hold up to heart rate frequency, the pulsatile pressure input will yield a markedly augmented SNA signal. Such a signal would saturate the baroreflex signal transduction, thereby disabling the baroreflex regulation of AP. We hypothesized that the transfer gain at heart rate frequency would be much smaller than that predicted from extrapolating the derivative characteristics. In anesthetized rabbits (n = 6), we estimated the neural arc transfer function in the frequency range up to 10 Hz. The transfer gain was lost at a rate of -20 dB/decade when the input frequency exceeded 0.8 Hz. A numerical simulation indicated that the high-cut characteristics above 0.8 Hz were effective to attenuate the pulsatile signal and preserve the open-loop gain when the baroreflex dynamic range was finite.

Mechanical model for simulating the conditioning of air in the respiratory tract.

PubMed

Bergonse Neto, Nelson; Von Bahten, Luiz Carlos; Moura, Luís Mauro; Coelho, Marlos de Souza; Stori Junior, Wilson de Souza; Bergonse, Gilberto da Fontoura Rey

2007-01-01

To create a mechanical model that could be regulated to simulate the conditioning of inspired and expired air with the same normal values of temperature, pressure, and relative humidity as those of the respiratory system of a healthy young man on mechanical ventilation. Using several types of materials, a mechanical device was built and regulated using normal values of vital capacity, tidal volume, maximal inspiratory pressure, positive end-expiratory pressure, and gas temperature in the system. The device was submitted to mechanical ventilation for a period of 29.8 min. The changes in the temperature of the air circulating in the system were recorded every two seconds. The statistical analysis of the data collected revealed that the device was approximately as efficient in the conditioning of air as is the respiratory system of a human being. By the study endpoint, we had developed a mechanical device capable of simulating the conditioning of air in the respiratory tract. The device mimics the conditions of temperature, pressure, and relative humidity seen in the respiratory system of healthy individuals.

Neural mechanisms in body fluid homeostasis.

PubMed

DiBona, G F

1986-12-01

Under steady-state conditions, urinary sodium excretion matches dietary sodium intake. Because extracellular fluid osmolality is tightly regulated, the quantity of sodium in the extracellular fluid determines the volume of this compartment. The left atrial volume receptor mechanism is an example of a neural mechanism of volume regulation. The left atrial mechanoreceptor, which functions as a sensor in the low-pressure vascular system, is located in the left atrial wall, which has a well-defined compliance relating intravascular volume to filling pressure. The left atrial mechanoreceptor responds to changes in wall left atrial tension by discharging into afferent vagal fibers. These fibers have suitable central nervous system representation whose related efferent neurohumoral mechanisms regulate thirst, renal excretion of water and sodium, and redistribution of the extracellular fluid volume. Efferent renal sympathetic nerve activity undergoes appropriate changes to facilitate renal sodium excretion during sodium surfeit and to facilitate renal sodium conservation during sodium deficit. By interacting with other important determinants of renal sodium excretion (e.g., renal arterial pressure), changes in efferent renal sympathetic nerve activity can significantly modulate the final renal sodium excretion response with important consequences in pathophysiological states (e.g., hypertension, edema-forming states).

Analysis of barosensitive mechanisms in yeast for Pressure Regulated Fermentation

NASA Astrophysics Data System (ADS)

Nomura, Kazuki; Iwahashi, Hitoshi; Iguchi, Akinori; Shigematsu, Toru

2013-06-01

Introduction: We are intending to develop a novel food processing technology, Pressure Regulated Fermentation (PReF), using pressure sensitive (barosensitive) fermentation microorganisms. Objectives of our study are to clarify barosensitive mechanisms for application to PReF technology. We isolated Saccharomyces cerevisiae barosensitive mutant a924E1 that was derived from the parent KA31a. Methods: Gene expression levels were analyzed by DNA microarray. The altered genes of expression levels were classified according to the gene function. Mutated genes were estimated by mating and producing diploid strains and confirmed by PCR of mitochondrial DNA (mtDNA). Results and Discussion: Gene expression profiles showed that genes of `Energy' function and that of encoding protein localized in ``Mitochondria'' were significantly down regulated in the mutant. These results suggest the respiratory deficiency and relationship between barosensitivity and respiratory deficiency. Since the respiratory functions of diploids showed non Mendelian inheritance, the respiratory deficiency was indicated to be due to mtDNA mutation. PCR analysis showed that the region of COX1 locus was deleted. COX1 gene encodes the subunit 1 of cytochrome c oxidase. For this reason, barosensitivity is strongly correlated with mitochondrial functions.

Comparison of automatic control systems

NASA Technical Reports Server (NTRS)

Oppelt, W

1941-01-01

This report deals with a reciprocal comparison of an automatic pressure control, an automatic rpm control, an automatic temperature control, and an automatic directional control. It shows the difference between the "faultproof" regulator and the actual regulator which is subject to faults, and develops this difference as far as possible in a parallel manner with regard to the control systems under consideration. Such as analysis affords, particularly in its extension to the faults of the actual regulator, a deep insight into the mechanism of the regulator process.

A longitudinal study of altered taste and smell perception and change in blood pressure.

PubMed

Liu, Y-H; Huang, Z; Vaidya, A; Li, J; Curhan, G C; Wu, S; Gao, X

2018-05-29

Previous studies suggest that olfactory receptors, which mediate smell chemosensation, are located in the kidney and involved in blood pressure regulation. Mammalian epithelial sodium channels located in taste receptor cells are also found to participate in blood pressure regulation. However, there is currently no human study that has examined the association between taste and smell function and blood pressure. We thus conducted a longitudinal study to examine whether participants with altered taste and smell perception had larger increases in blood pressure compared with those without altered perception in a community-based cohort. The study included 5190 Chinese adults (4058 men and 1132 women) who were normotensive at baseline. Taste and smell perception were assessed via questionnaire in 2012 (baseline). Blood pressure was measured in 2012 and 2014 to determine relative change in blood pressure. Mean differences of 2-year blood pressure change and 95% confidence intervals (CIs) across four categories of taste and smell perception were calculated after adjusting for known risk factors for hypertension. After adjusting for potential confounders, individuals with altered taste and smell perception had larger increases in systolic blood pressure (adjusted mean difference = 5.1 mmHg, 95% CI: 0.1-10.0, p-value: 0.04) and mean arterial pressure (adjusted mean difference = 3.8 mmHg, 95% CI: 0.4-7.1, p-value: 0.03) after two years of follow-up compared with those having neither altered taste nor altered smell perception. No significant association was observed in individuals with altered taste or smell perception only. Our results suggest an association between chemosensory function and blood pressure. Copyright © 2018 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.

Regulation of intraocular pressure in mice: structural analysis of dopaminergic and serotonergic systems in response to cabergoline.

PubMed

Platania, Chiara Bianca Maria; Leggio, Gian Marco; Drago, Filippo; Salomone, Salvatore; Bucolo, Claudio

2013-11-01

Elevated intraocular pressure (IOP) is the main recognized risk factor of glaucoma. To investigate the contribution of dopaminergic and serotonergic systems in IOP regulation, we used cabergoline, a mixed dopamine and serotonin agonist, in C57BL/6J WT and dopamine D₃ receptor knock-out (D₃R⁻/⁻) mice with normal eye pressure or steroid-induced ocular hypertension. Furthermore, we studied the structural basis of the cabergoline-mediated activation of the dopaminergic and serotonergic systems by molecular modeling. Topical application of cabergoline, significantly decreased, in a dose-dependent manner, the intraocular pressure in WT mice, both in an ocular normotensive group (-9, -5 and -2 mmHg with 5%, 1%, and 0.1%, respectively) and an ocular hypertensive group, with a prolonged effect in this latter group. No change of intraocular pressure was observed after topical application of cabergoline in D₃R⁻/⁻ mice. We modeled and optimized, with molecular dynamics, structures of hD₃, h5HT(1A) and h5HT(2A-C) receptors; thereafter we carried out molecular docking of cabergoline. Docking revealed that binding of cabergoline into D₃ and 5HT(1A) receptors is associated with a better desolvation energy in comparison to 5HT(2A-C) binding. In conclusion, the present study support the hypothesis that dopaminergic system is pivotal to regulate IOP and that D₃R represents an intriguing target in the treatment of glaucoma. Furthermore, the structure-based computational approach adopted in this study is able to build and refine structure models of homologous dopaminergic and serotonergic receptors that may be of interest for structure-based drug discovery of ligands, with dopaminergic selectivity or with multi-pharmacological profile, potentially useful to treat optic neuropathies. Copyright © 2013 Elsevier Inc. All rights reserved.

Gastrin stimulates renal dopamine production by increasing the renal tubular uptake of l-DOPA.

PubMed

Jiang, Xiaoliang; Zhang, Yanrong; Yang, Yu; Yang, Jian; Asico, Laureano D; Chen, Wei; Felder, Robin A; Armando, Ines; Jose, Pedro A; Yang, Zhiwei

2017-01-01

Gastrin is a peptide hormone that is involved in the regulation of sodium balance and blood pressure. Dopamine, which is also involved in the regulation of sodium balance and blood pressure, directly or indirectly interacts with other blood pressure-regulating hormones, including gastrin. This study aimed to determine the mechanisms of the interaction between gastrin and dopamine and tested the hypothesis that gastrin produced in the kidney increases renal dopamine production to keep blood pressure within the normal range. We show that in human and mouse renal proximal tubule cells (hRPTCs and mRPTCs, respectively), gastrin stimulates renal dopamine production by increasing the cellular uptake of l-DOPA via the l-type amino acid transporter (LAT) at the plasma membrane. The uptake of l-DOPA in RPTCs from C57Bl/6J mice is lower than in RPTCs from normotensive humans. l-DOPA uptake in renal cortical slices is also lower in salt-sensitive C57Bl/6J than in salt-resistant BALB/c mice. The deficient renal cortical uptake of l-DOPA in C57Bl/6J mice may be due to decreased LAT-1 activity that is related to its decreased expression at the plasma membrane, relative to BALB/c mice. We also show that renal-selective silencing of Gast by the renal subcapsular injection of Gast siRNA in BALB/c mice decreases renal dopamine production and increases blood pressure. These results highlight the importance of renal gastrin in stimulating renal dopamine production, which may give a new perspective in the prevention and treatment of hypertension. Copyright © 2017 the American Physiological Society.

Gene delivery by direct injection (microinjection) using a controlled-flow system.

PubMed

Dean, David A

2006-12-01

INTRODUCTIONThis protocol describes a method for constant-flow microinjection using the Pneumatic PicoPump (World Precision Instruments). This type of system is very simple and can be assembled on a relatively low budget. In this method, a constant flow of sample is delivered from the tip of the pipette, and the amount of sample injected into the cell is determined by how long the pipette remains in the cell. A typical system is composed of a pressure regulator that can be adjusted for two pressures (back pressure and injection pressure), a capillary holder, and a coarse and fine micromanipulator.

Design of an FPGA-based electronic flow regulator (EFR) for spacecraft propulsion system

NASA Astrophysics Data System (ADS)

Manikandan, J.; Jayaraman, M.; Jayachandran, M.

2011-02-01

This paper describes a scheme for electronically regulating the flow of propellant to the thruster from a high-pressure storage tank used in spacecraft application. Precise flow delivery of propellant to thrusters ensures propulsion system operation at best efficiency by maximizing the propellant and power utilization for the mission. The proposed field programmable gate array (FPGA) based electronic flow regulator (EFR) is used to ensure precise flow of propellant to the thrusters from a high-pressure storage tank used in spacecraft application. This paper presents hardware and software design of electronic flow regulator and implementation of the regulation logic onto an FPGA.Motivation for proposed FPGA-based electronic flow regulation is on the disadvantages of conventional approach of using analog circuits. Digital flow regulation overcomes the analog equivalent as digital circuits are highly flexible, are not much affected due to noise, accurate performance is repeatable, interface is easier to computers, storing facilities are possible and finally failure rate of digital circuits is less. FPGA has certain advantages over ASIC and microprocessor/micro-controller that motivated us to opt for FPGA-based electronic flow regulator. Also the control algorithm being software, it is well modifiable without changing the hardware. This scheme is simple enough to adopt for a wide range of applications, where the flow is to be regulated for efficient operation.The proposed scheme is based on a space-qualified re-configurable field programmable gate arrays (FPGA) and hybrid micro circuit (HMC). A graphical user interface (GUI) based application software is also developed for debugging, monitoring and controlling the electronic flow regulator from PC COM port.

A Hydraulic Blowdown Servo System For Launch Vehicle

NASA Astrophysics Data System (ADS)

Chen, Anping; Deng, Tao

2016-07-01

This paper introduced a hydraulic blowdown servo system developed for a solid launch vehicle of the family of Chinese Long March Vehicles. It's the thrust vector control (TVC) system for the first stage. This system is a cold gas blowdown hydraulic servo system and consist of gas vessel, hydraulic reservoir, servo actuator, digital control unit (DCU), electric explosion valve, and pressure regulator etc. A brief description of the main assemblies and characteristics follows. a) Gas vessel is a resin/carbon fiber composite over wrapped pressure vessel with a titanium liner, The volume of the vessel is about 30 liters. b) Hydraulic reservoir is a titanium alloy piston type reservoir with a magnetostrictive sensor as the fluid level indicator. The volume of the reservoir is about 30 liters. c) Servo actuator is a equal area linear piston actuator with a 2-stage low null leakage servo valve and a linear variable differential transducer (LVDT) feedback the piston position, Its stall force is about 120kN. d) Digital control unit (DCU) is a compact digital controller based on digital signal processor (DSP), and deployed dual redundant 1553B digital busses to communicate with the on board computer. e) Electric explosion valve is a normally closed valve to confine the high pressure helium gas. f) Pressure regulator is a spring-loaded poppet pressure valve, and regulates the gas pressure from about 60MPa to about 24MPa. g) The whole system is mounted in the aft skirt of the vehicle. h) This system delivers approximately 40kW hydraulic power, by contrast, the total mass is less than 190kg. the power mass ratio is about 0.21. Have finished the development and the system test. Bench and motor static firing tests verified that all of the performances have met the design requirements. This servo system is complaint to use of the solid launch vehicle.

16 CFR 1512.10 - Requirements for tires.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Requirements for tires. 1512.10 Section 1512... REGULATIONS REQUIREMENTS FOR BICYCLES Regulations § 1512.10 Requirements for tires. The manufacturer's recommended inflation pressure shall be molded into or onto the sidewall of the tire in lettering no less than...

77 FR 6525 - Airworthiness Directives; Bombardier, Inc., Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-08

... an inspection to determine if a certain oxygen cylinder and regulator assembly (CRA) is installed and the replacement of affected oxygen CRAs. That NPRM was prompted by reports of deformation found at the neck of the pressure regulator body on the oxygen CRA. This action revises that NPRM by revising the...

Role of Affective Self-Regulatory Efficacy in Diverse Spheres of Psychosocial Functioning.

ERIC Educational Resources Information Center

Bandura, Albert; Caprara, Gian Vittorio; Barbaranelli, Claudio; Gerbino, Maria; Pastorelli, Concetta

2003-01-01

Examined influence of perceived self-efficacy for affect regulation with older adolescents. Found that self-efficacy to regulate affect related to high efficacy to manage academic development, resist social pressures for antisocial activities, and engage with empathy in others' emotional experiences. Perceived self-efficacy for affect regulation…

Pressure ulcer prevention program: a journey.

PubMed

Delmore, Barbara; Lebovits, Sarah; Baldock, Philip; Suggs, Barbara; Ayello, Elizabeth A

2011-01-01

The Centers for Medicare & Medicaid Services' regulations regarding nonpayment for hospital-acquired conditions such as pressure ulcers have prompted a marked increase in focus on preventive care. Our hospital also used this change in payment policy as an opportunity to strengthen our pressure ulcer prevention practices. We used an 8-spoke prevention wheel to develop and implement practice changes that reduced pressure ulcer incidence from 7.3% to 1.3% in 3 years. Because it is about the journey, we will describe the mechanisms we designed and implemented, and identify strategies that worked or did not work as we promulgated a quality improvement process for pressure ulcer prevention in our large urban hospital center.

Dynamics of phenotypic switching of bacterial cells with temporal fluctuations in pressure

NASA Astrophysics Data System (ADS)

Nepal, Sudip; Kumar, Pradeep

2018-05-01

Phenotypic switching is one of the mechanisms by which bacteria thrive in ever changing environmental conditions around them. Earlier studies have shown that the application of steady high hydrostatic pressure leads to stochastic switching of mesophilic bacteria from a cellular phenotype having a normal cell cycle to another phenotype lacking cell division. Here, we have studied the dynamics of this phenotypic switching with fluctuating periodic pressure using a set of experiments and a theoretical model. Our results suggest that the phenotypic switching rate from high-pressure phenotype to low-pressure phenotype in the reversible regime is larger as compared to the switching rate from low-pressure phenotype to high-pressure phenotype. Furthermore, we find that even though the cell division and elongation are presumably regulated by a large number of genes the underlying physics of the dynamics of stochastic switching at high pressure is captured reasonably well by a simple two-state model.

Simulation Analysis of Computer-Controlled pressurization for Mixture Ratio Control

NASA Technical Reports Server (NTRS)

Alexander, Leslie A.; Bishop-Behel, Karen; Benfield, Michael P. J.; Kelley, Anthony; Woodcock, Gordon R.

2005-01-01

A procedural code (C++) simulation was developed to investigate potentials for mixture ratio control of pressure-fed spacecraft rocket propulsion systems by measuring propellant flows, tank liquid quantities, or both, and using feedback from these measurements to adjust propellant tank pressures to set the correct operating mixture ratio for minimum propellant residuals. The pressurization system eliminated mechanical regulators in favor of a computer-controlled, servo- driven throttling valve. We found that a quasi-steady state simulation (pressure and flow transients in the pressurization systems resulting from changes in flow control valve position are ignored) is adequate for this purpose. Monte-Carlo methods are used to obtain simulated statistics on propellant depletion. Mixture ratio control algorithms based on proportional-integral-differential (PID) controller methods were developed. These algorithms actually set target tank pressures; the tank pressures are controlled by another PID controller. Simulation indicates this approach can provide reductions in residual propellants.

Minimal role of nitric oxide in basal coronary flow regulation and cardiac energetics of blood-perfused isolated canine heart.

PubMed Central

Saeki, A; Recchia, F A; Senzaki, H; Kass, D A

1996-01-01

1. The role of nitric oxide (NO) in the regulation of basal coronary perfusion and ventricular chamber energetics was studied in isovolumetrically contracting isolated blood-perfused canine hearts. Hearts were cross-perfused by a donor animal prior to isolation, and chamber volume controlled by a servo-pump. Coronary sinus flow and arterial-coronary sinus oxygen difference were measured to determine energetic efficiency. 2. NO synthase (NOS) was competitively inhibited by NG-monomethyl-L-arginine (L-NMMA; 0.5 mg kg-1, intracoronary), resulting in a reduction of acetylcholine (50 micrograms min-1)-induced flow augmentation from 143 to 62% (P < 0.001). 3. NOS inhibition had no significant effect on basal coronary flow. Coronary pressure-flow relationships were determined at a constant cardiac workload by varying mean perfusion pressure between 20 and 150 mmHg. Neither the shape of the relationship, nor the low-pressure value at which flow regulation was substantially diminished were altered by NOS inhibition. 4. Myocardial efficiency was assessed by the relationship between myocardial oxygen consumption and total pressure-volume area (PVA), with cavity volume altered to generate varying PVAs. This relative load-independent measure of energetic efficiency was minimally altered by NOS inhibition. 5. These results contrast with isolated crystalloid-perfused heart experiments and suggest that in hearts with highly controlled ventricular loading and whole-blood perfusion, effects of basal NO production on coronary perfusion and left ventricular energetics are minimal. PMID:8866868

Genome-wide association analysis identifies novel blood pressure loci and offers biological insights into cardiovascular risk.

PubMed

Warren, Helen R; Evangelou, Evangelos; Cabrera, Claudia P; Gao, He; Ren, Meixia; Mifsud, Borbala; Ntalla, Ioanna; Surendran, Praveen; Liu, Chunyu; Cook, James P; Kraja, Aldi T; Drenos, Fotios; Loh, Marie; Verweij, Niek; Marten, Jonathan; Karaman, Ibrahim; Lepe, Marcelo P Segura; O'Reilly, Paul F; Knight, Joanne; Snieder, Harold; Kato, Norihiro; He, Jiang; Tai, E Shyong; Said, M Abdullah; Porteous, David; Alver, Maris; Poulter, Neil; Farrall, Martin; Gansevoort, Ron T; Padmanabhan, Sandosh; Mägi, Reedik; Stanton, Alice; Connell, John; Bakker, Stephan J L; Metspalu, Andres; Shields, Denis C; Thom, Simon; Brown, Morris; Sever, Peter; Esko, Tõnu; Hayward, Caroline; van der Harst, Pim; Saleheen, Danish; Chowdhury, Rajiv; Chambers, John C; Chasman, Daniel I; Chakravarti, Aravinda; Newton-Cheh, Christopher; Lindgren, Cecilia M; Levy, Daniel; Kooner, Jaspal S; Keavney, Bernard; Tomaszewski, Maciej; Samani, Nilesh J; Howson, Joanna M M; Tobin, Martin D; Munroe, Patricia B; Ehret, Georg B; Wain, Louise V

2017-03-01

Elevated blood pressure is the leading heritable risk factor for cardiovascular disease worldwide. We report genetic association of blood pressure (systolic, diastolic, pulse pressure) among UK Biobank participants of European ancestry with independent replication in other cohorts, and robust validation of 107 independent loci. We also identify new independent variants at 11 previously reported blood pressure loci. In combination with results from a range of in silico functional analyses and wet bench experiments, our findings highlight new biological pathways for blood pressure regulation enriched for genes expressed in vascular tissues and identify potential therapeutic targets for hypertension. Results from genetic risk score models raise the possibility of a precision medicine approach through early lifestyle intervention to offset the impact of blood pressure-raising genetic variants on future cardiovascular disease risk.

Genome-wide association analysis identifies novel blood pressure loci and offers biological insights into cardiovascular risk

PubMed Central

Ntalla, Ioanna; Surendran, Praveen; Liu, Chunyu; Cook, James P; Kraja, Aldi T; Drenos, Fotios; Loh, Marie; Verweij, Niek; Marten, Jonathan; Karaman, Ibrahim; Segura Lepe, Marcelo P; O’Reilly, Paul F; Knight, Joanne; Snieder, Harold; Kato, Norihiro; He, Jiang; Tai, E Shyong; Said, M Abdullah; Porteous, David; Alver, Maris; Poulter, Neil; Farrall, Martin; Gansevoort, Ron T; Padmanabhan, Sandosh; Mägi, Reedik; Stanton, Alice; Connell, John; Bakker, Stephan J L; Metspalu, Andres; Shields, Denis C; Thom, Simon; Brown, Morris; Sever, Peter; Esko, Tõnu; Hayward, Caroline; van der Harst, Pim; Saleheen, Danish; Chowdhury, Rajiv; Chambers, John C; Chasman, Daniel I; Chakravarti, Aravinda; Newton-Cheh, Christopher; Lindgren, Cecilia M; Levy, Daniel; Kooner, Jaspal S; Keavney, Bernard; Tomaszewski, Maciej; Samani, Nilesh J; Howson, Joanna M M; Tobin, Martin D; Munroe, Patricia B; Ehret, Georg B; Wain, Louise V

2017-01-01

Elevated blood pressure is the leading heritable risk factor for cardiovascular disease worldwide. We report genetic association of blood pressure (systolic, diastolic, pulse pressure) among UK Biobank participants of European ancestry with independent replication in other cohorts, and robust validation of 107 independent loci. We also identify new independent variants at 11 previously reported blood pressure loci. Combined with results from a range of in silico functional analyses and wet bench experiments, our findings highlight new biological pathways for blood pressure regulation enriched for genes expressed in vascular tissues and identify potential therapeutic targets for hypertension. Results from genetic risk score models raise the possibility of a precision medicine approach through early lifestyle intervention to offset the impact of blood pressure raising genetic variants on future cardiovascular disease risk. PMID:28135244

[Micromotor recording of writing pressure during intracerevral stimulation at stereotactic operations (author's transl)].

PubMed

Schneider, H

1975-12-22

Eight cases of spastic torticollis were examined during the course of stereotactic operations with the writing pressure apparatus of Steinwachs while the ventrolateral thalamus was stimulated. When 50 stimuli per sec are given, the significant changes of motor function in writing are the following: slowing of writing speed, an increase in writing pressure, greater changes of pressure amplitude with tendences to parallel course. With 25 stimuli per sec, simular results may appear, but smaller amplitude changes and lowering of writing pressure may also occur. When 8 stimuli per sec are given, no changes of pressure patterns in writing were found. Three typical cases are described. It is concluded that the recording of fine pressure changes in writing may indicate alterations of cerebral motor regulations although specific changes for certain thalamic stimulus locations were lacking.

Carotid interventions and blood pressure.

PubMed

Hirschl, Mirko; Kundi, Michael

2014-12-01

Arterial baroreceptors are pressure sensors found in the carotid sinus near the bifurcation of the carotid artery and in the aortic arch. Carotid interventions, whether endovascular or surgical, affect this complicated control system and the post-interventional blood pressure behavior. Comparisons between the intervention techniques, however, are challenging due to the varying measurement methods, duration of observation, and patient populations. The question as to which interventional method is preferable, if undisturbed regulation of blood pressure is concerned, still remains unanswered. The fact that blood pressure events (i.e., hemodynamic instability, hypertension, unstable blood pressure) frequently occur both immediately after intervention and in the long term, mandates a particularly careful cardiopulmonary and blood pressure monitoring. Direct and indirect measurements of baroreceptor sensitivity can be helpful in identifying high-risk patients, although the association to hard clinical endpoints is rarely documented for methodological reasons.

The Relationship of Mucus Concentration (Hydration) to Mucus Osmotic Pressure and Transport in Chronic Bronchitis

PubMed Central

Coakley, Raymond D.; Button, Brian; Henderson, Ashley G.; Zeman, Kirby L.; Alexis, Neil E.; Peden, David B.; Lazarowski, Eduardo R.; Davis, C. William; Bailey, Summer; Fuller, Fred; Almond, Martha; Qaqish, Bahjat; Bordonali, Elena; Rubinstein, Michael; Bennett, William D.; Kesimer, Mehmet; Boucher, Richard C.

2015-01-01

Rationale: Chronic bronchitis (CB) is characterized by persistent cough and sputum production. Studies were performed to test whether mucus hyperconcentration and increased partial osmotic pressure, in part caused by abnormal purine nucleotide regulation of ion transport, contribute to the pathogenesis of CB. Objectives: We tested the hypothesis that CB is characterized by mucus hyperconcentration, increased mucus partial osmotic pressures, and reduced mucus clearance. Methods: We measured in subjects with CB as compared with normal and asymptomatic smoking control subjects indices of mucus concentration (hydration; i.e., percentage solids) and sputum adenine nucleotide/nucleoside concentrations. In addition, sputum partial osmotic pressures and mucus transport rates were measured in subjects with CB. Measurements and Results: CB secretions were hyperconcentrated as indexed by an increase in percentage solids and total mucins, in part reflecting decreased extracellular nucleotide/nucleoside concentrations. CB mucus generated concentration-dependent increases in partial osmotic pressures into ranges predicted to reduce mucus transport. Mucociliary clearance (MCC) in subjects with CB was negatively correlated with mucus concentration (percentage solids). As a test of relationships between mucus concentration and disease, mucus concentrations and MCC were compared with FEV1, and both were significantly correlated. Conclusions: Abnormal regulation of airway surface hydration may slow MCC in CB and contribute to disease pathogenesis. PMID:25909230

A regulator for pressure-controlled total-liquid ventilation.

PubMed

Robert, Raymond; Micheau, Philippe; Avoine, Olivier; Beaudry, Benoit; Beaulieu, Alexandre; Walti, Hervé

2010-09-01

Total-liquid ventilation (TLV) is an innovative experimental method of mechanical-assisted ventilation in which lungs are totally filled and then ventilated with a tidal volume of perfluorochemical liquid by using a dedicated liquid ventilator. Such a novel medical device must resemble other conventional ventilators: it must be able to conduct controlled-pressure ventilation. The objective was to design a robust controller to perform pressure-regulated expiratory flow and to implement it on our latest liquid-ventilator prototype (Inolivent-4). Numerical simulations, in vitro experiments, and in vivo experiments in five healthy term newborn lambs have demonstrated that it was efficient to generate expiratory flows while avoiding collapses. Moreover, the in vivo results have demonstrated that our liquid ventilator can maintain adequate gas exchange, normal acid-base equilibrium, and achieve greater minute ventilation, better oxygenation and CO2 extraction, while nearing flow limits. Hence, it is our suggestion to perform pressure-controlled ventilation during expiration with minute ventilation equal or superior to 140 mL x min(-1) x kg(-1) in order to ensure PaCO2 below 55 mmHg. From a clinician's point of view, pressure-controlled ventilation greatly simplifies the use of the liquid ventilator, which will certainly facilitate its introduction in intensive care units for clinical applications.

Advanced Liquid Feed Experiment

NASA Astrophysics Data System (ADS)

Distefano, E.; Noll, C.

1993-06-01

The Advanced Liquid Feed Experiment (ALFE) is a Hitchhiker experiment flown on board the Shuttle of STS-39 as part of the Space Test Payload-1 (STP-1). The purpose of ALFE is to evaluate new propellant management components and operations under the low gravity flight environment of the Space Shuttle for eventual use in an advanced spacecraft feed system. These components and operations include an electronic pressure regulator, an ultrasonic flowmeter, an ultrasonic point sensor gage, and on-orbit refill of an auxiliary propellant tank. The tests are performed with two transparent tanks with dyed Freon 113, observed by a camera and controlled by ground commands and an on-board computer. Results show that the electronic pressure regulator provides smooth pressure ramp-up, sustained pressure control, and the flexibility to change pressure settings in flight. The ultrasonic flowmeter accurately measures flow and detects gas ingestion. The ultrasonic point sensors function well in space, but not as a gage during sustained low-gravity conditions, as they, like other point gages, are subject to the uncertainties of propellant geometry in a given tank. Propellant transfer operations can be performed with liquid-free ullage equalization at a 20 percent fill level, gas-free liquid transfer from 20-65 percent fill level, minimal slosh, and can be automated.

Rules and Regulations for Small Passenger Vessels (Under 100 Gross Tons).

DTIC Science & Technology

1977-07-01

the space having seats and the num- the conditions under which it is Issued ber permitted by the area criteria for the and whether or not the vesel Is...boilers and unfired pressure § 176.25-32 Pressure vesels .--L vessels shall be checked. (a) At each initial and subsequent in- (3) Pressure vessels which...classes of vesels strued as limiting the marine inspector which, In the course of their voyage, do from making such tests or inspections O not proceed

Vitamin D and Hypertension.

PubMed

Jeong, Hye Yun; Park, Kyung Mi; Lee, Mi Jung; Yang, Dong Ho; Kim, Sang Hoon; Lee, So-Young

2017-09-01

Vitamin D has the pleiotropic effects in multiple organ systems, and vitamin D deficiency was suggested to be associated with high blood pressure according to previous reports. Several interventional studies have examined the effect of vitamin D supplementation on high blood pressure patients, but the results have been inconsistent. In this article, we examined the literature that have proposed a mechanism involving vitamin D in the regulation of blood pressure and review previous observational and interventional studies that have shown the relationship between vitamin D and hypertension among various populations.

Regulation of Epithelial Sodium Transport via Epithelial Na+ Channel

PubMed Central

Marunaka, Yoshinori; Niisato, Naomi; Taruno, Akiyuki; Ohta, Mariko; Miyazaki, Hiroaki; Hosogi, Shigekuni; Nakajima, Ken-ichi; Kusuzaki, Katsuyuki; Ashihara, Eishi; Nishio, Kyosuke; Iwasaki, Yoshinobu; Nakahari, Takashi; Kubota, Takahiro

2011-01-01

Renal epithelial Na+ transport plays an important role in homeostasis of our body fluid content and blood pressure. Further, the Na+ transport in alveolar epithelial cells essentially controls the amount of alveolar fluid that should be kept at an appropriate level for normal gas exchange. The epithelial Na+ transport is generally mediated through two steps: (1) the entry step of Na+ via epithelial Na+ channel (ENaC) at the apical membrane and (2) the extrusion step of Na+ via the Na+, K+-ATPase at the basolateral membrane. In general, the Na+ entry via ENaC is the rate-limiting step. Therefore, the regulation of ENaC plays an essential role in control of blood pressure and normal gas exchange. In this paper, we discuss two major factors in ENaC regulation: (1) activity of individual ENaC and (2) number of ENaC located at the apical membrane. PMID:22028593

Homeostasis in Primates in the Hyperdynamic Environment. [circadian timekeeping and effects of lower body positive pressure on sleep

NASA Technical Reports Server (NTRS)

Fuller, C. A.

1985-01-01

The influence of chronic centrifugation upon the homestatic regulation of the circadian timekeeping system was examined. The interactions of body temperature regulation and the behavioral state of arousal were studied by evaluating the influence of cephalic fluid shifts induced by lower body positive air pressure (LBPP), upon these systems. The small diurnal squirrel monkey (Saimiri sciureus) was used as the non-human primate model. Results show that the circadian timekeeping system of these primates is functional in the hyperdynamic environment, however, some of its components appear to be regulated at different homeostatic levels. The LBPP resulted in an approximate 0.7 C decrease in DBT (p 0.01). However, although on video some animals appeared drowsy during LBPP, sleep recording revealed no significant changes in state of arousal. Thus, the physiological mechanisms underlying this lowering of body temperature can be independent of the arousal state.

Single-dose volume regulation algorithm for a gas-compensated intrathecal infusion pump.

PubMed

Nam, Kyoung Won; Kim, Kwang Gi; Sung, Mun Hyun; Choi, Seong Wook; Kim, Dae Hyun; Jo, Yung Ho

2011-01-01

The internal pressures of medication reservoirs of gas-compensated intrathecal medication infusion pumps decrease when medication is discharged, and these discharge-induced pressure drops can decrease the volume of medication discharged. To prevent these reductions, the volumes discharged must be adjusted to maintain the required dosage levels. In this study, the authors developed an automatic control algorithm for an intrathecal infusion pump developed by the Korean National Cancer Center that regulates single-dose volumes. The proposed algorithm estimates the amount of medication remaining and adjusts control parameters automatically to maintain single-dose volumes at predetermined levels. Experimental results demonstrated that the proposed algorithm can regulate mean single-dose volumes with a variation of <3% and estimate the remaining medication volume with an accuracy of >98%. © 2010, Copyright the Authors. Artificial Organs © 2010, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Instrumentation for measurement of aircraft noise and sonic boom

NASA Technical Reports Server (NTRS)

Zuckerwar, A. J. (Inventor)

1975-01-01

A jet aircraft noise and sonic boom measuring device which converts sound pressure into electric current is described. An electric current proportional to the sound pressure level at a condenser microphone is produced and transmitted over a cable, amplified by a zero drive amplifier and recorded on magnetic tape. The converter is comprised of a local oscillator, a dual-gate field-effect transistor (FET) mixer and a voltage regulator/impedance translator. A carrier voltage that is applied to one of the gates of the FET mixer is generated by the local oscillator. The microphone signal is mixed with the carrier to produce an electrical current at the frequency of vibration of the microphone diaphragm by the FET mixer. The voltage of the local oscillator and mixer stages is regulated, the carrier at the output is eliminated, and a low output impedance at the cable terminals is provided by the voltage regulator/impedance translator.

Regulation of Coronary Blood Flow

PubMed Central

Goodwill, Adam G.; Dick, Gregory M.; Kiel, Alexander M.; Tune, Johnathan D.

2018-01-01

The heart is uniquely responsible for providing its own blood supply through the coronary circulation. Regulation of coronary blood flow is quite complex and, after over 100 years of dedicated research, is understood to be dictated through multiple mechanisms that include extravascular compressive forces (tissue pressure), coronary perfusion pressure, myogenic, local metabolic, endothelial as well as neural and hormonal influences. While each of these determinants can have profound influence over myocardial perfusion, largely through effects on end-effector ion channels, these mechanisms collectively modulate coronary vascular resistance and act to ensure that the myocardial requirements for oxygen and substrates are adequately provided by the coronary circulation. The purpose of this series of Comprehensive Physiology is to highlight current knowledge regarding the physiologic regulation of coronary blood flow, with emphasis on functional anatomy and the interplay between the physical and biological determinants of myocardial oxygen delivery. PMID:28333376

Promoted ignition of oxygen regulators

NASA Technical Reports Server (NTRS)

Newton, Barry E.; Langford, Richard K.; Meyer, Gene R.

1989-01-01

An investigation has been conducted of the ignition-containment capability of 12 oxygen regulators contaminated by various levels of hydrocarbon oils and subjected to promoted ignition. The regulators inlets were pressurized to 15.2 MPa with gaseous oxygen, and the oil was ignited by an electrical arc located upstream of the test article inlet port; the flame was allowed to propagate with the oxygen flow throughout the regulator internal cavities. The resulting reactions, which ranged in character from complete containment of the promoted ignition for one two-stage regulator to extensive burning and explosive energy release for several other (both single- and double-stage) regulators, indicate the need to prevent oil from being introduced into regulators.

Promoted ignition of oxygen regulators

NASA Astrophysics Data System (ADS)

Newton, Barry E.; Langford, Richard K.; Meyer, Gene R.

An investigation has been conducted of the ignition-containment capability of 12 oxygen regulators contaminated by various levels of hydrocarbon oils and subjected to promoted ignition. The regulators inlets were pressurized to 15.2 MPa with gaseous oxygen, and the oil was ignited by an electrical arc located upstream of the test article inlet port; the flame was allowed to propagate with the oxygen flow throughout the regulator internal cavities. The resulting reactions, which ranged in character from complete containment of the promoted ignition for one two-stage regulator to extensive burning and explosive energy release for several other (both single- and double-stage) regulators, indicate the need to prevent oil from being introduced into regulators.

Genes that are involved in high hydrostatic pressure treatments in a Listeria monocytogenes Scott A ctsR deletion mutant

USDA-ARS?s Scientific Manuscript database

Listeria monocytogenes is a food-borne pathogen of significant threat to public health. High Hydrostatic Pressure (HHP) treatment can be used to control L. monocytogenes in food. The CtsR (class three stress gene repressor) protein negatively regulates the expression of class III heat shock genes....

9 CFR 381.222 - States designated under paragraph 5(c) of the Act; application of regulations.

Code of Federal Regulations, 2011 CFR

2011-01-01

... blood or marriage, provided that this will not conflict with municipal or State requirements; and except... mechanical printing device or a self-destructive pressure sensitive sticker, and provided the label shows the... by the use of pressure sensitive tape of a type that cannot be removed without visible evidence of...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bessette, R.D.

The paper discusses the pressures on the industrial boiler owner today which affect how he meets his energy needs. As a result of these pressures, especially the environmental regulations, the author sees some major trends which may be indicative of what the future will hold and he discusses these. The author finally describes what the industrial power plant will be in the next 10--20 years.

49 CFR 173.127 - Class 5, Division 5.1-Definition and assignment of packing groups.

Code of Federal Regulations, 2013 CFR

2013-10-01

... pressure rise time of a 1:1 perchloric acid (50 percent)/cellulose mixture. (ii) Packing Group II, any... not met. (iii) Packing Group III, any material which exhibits a mean pressure rise time less than or... packing groups. 173.127 Section 173.127 Transportation Other Regulations Relating to Transportation...

Clock genes explain large proportion of phenotypic variance in systolic blood pressure and this control is not modified by environmental temperature

USDA-ARS?s Scientific Manuscript database

BACKGROUND: Diurnal variation in blood pressure (BP) is regulated, in part, by an endogenous circadian clock; however, few human studies have identified associations between clock genes and BP. Accounting for environmental temperature may be necessary to correct for seasonal bias. METHODS: We examin...

Effects of endurance training on blood pressure, blood pressure-regulating mechanisms, and cardiovascular risk factors.

PubMed

Cornelissen, Véronique A; Fagard, Robert H

2005-10-01

Previous meta-analyses of randomized controlled trials on the effects of chronic dynamic aerobic endurance training on blood pressure reported on resting blood pressure only. Our aim was to perform a comprehensive meta-analysis including resting and ambulatory blood pressure, blood pressure-regulating mechanisms, and concomitant cardiovascular risk factors. Inclusion criteria of studies were: random allocation to intervention and control; endurance training as the sole intervention; inclusion of healthy sedentary normotensive or hypertensive adults; intervention duration of > or =4 weeks; availability of systolic or diastolic blood pressure; and publication in a peer-reviewed journal up to December 2003. The meta-analysis involved 72 trials, 105 study groups, and 3936 participants. After weighting for the number of trained participants and using a random-effects model, training induced significant net reductions of resting and daytime ambulatory blood pressure of, respectively, 3.0/2.4 mm Hg (P<0.001) and 3.3/3.5 mm Hg (P<0.01). The reduction of resting blood pressure was more pronounced in the 30 hypertensive study groups (-6.9/-4.9) than in the others (-1.9/-1.6; P<0.001 for all). Systemic vascular resistance decreased by 7.1% (P<0.05), plasma norepinephrine by 29% (P<0.001), and plasma renin activity by 20% (P<0.05). Body weight decreased by 1.2 kg (P<0.001), waist circumference by 2.8 cm (P<0.001), percent body fat by 1.4% (P<0.001), and the homeostasis model assessment index of insulin resistance by 0.31 U (P<0.01); HDL cholesterol increased by 0.032 mmol/L(-1) (P<0.05). In conclusion, aerobic endurance training decreases blood pressure through a reduction of vascular resistance, in which the sympathetic nervous system and the renin-angiotensin system appear to be involved, and favorably affects concomitant cardiovascular risk factors.

Refuge alternatives relief valve testing and design

PubMed Central

Lutz, T.J.; Bissert, P.T.; Homce, G.T.; Yonkey, J.A.

2016-01-01

The U.S. National Institute for Occupational Safety and Health (NIOSH) has been researching refuge alternatives (RAs) since 2007. RAs typically have built-in pressure relief valves (PRVs) to prevent the unit from reaching unsafe pressures. The U.S. Mine Safety and Health Administration requires that these valves vent the chamber at a maximum pressure of 1.25 kPa (0.18 psi, 5.0 in. H2O), or as specified by the manufacturer, above mine atmospheric pressure in the RA. To facilitate PRV testing, an instrumented benchtop test fixture was developed using an off-the-shelf centrifugal blower and ductwork. Relief pressures and flow characteristics were measured for three units: (1) a modified polyvinyl chloride check valve, (2) an off-the-shelf brass/cast-iron butterfly check valve and (3) a commercially available valve that was designed specifically for one manufacturer’s steel prefabricated RAs and had been adapted for use in one mine operator’s built-in-place RA. PRVs used in tent-style RAs were not investigated. The units were tested with different modifications and configurations in order to check compliance with Title 30 Code of Federal Regulations, or 30 CFR, regulations. The commercially available relief valve did not meet the 30 CFR relief pressure specification but may meet the manufacturer’s specification. Alternative valve designs were modified to meet the 30 CFR relief pressure specification, but all valve designs will need further design research to examine survivability in the event of a 103 kPa (15.0 psi) impulse overpressure during a disaster. PMID:28018003

Molecular regulation of NKCC2 in the thick ascending limb

PubMed Central

Ares, Gustavo R.; Caceres, Paulo S.

2011-01-01

The kidney plays an essential role in blood pressure regulation by controlling short-term and long-term NaCl and water balance. The thick ascending limb of the loop of Henle (TAL) reabsorbs 25–30% of the NaCl filtered by the glomeruli in a process mediated by the apical Na+-K+-2Cl− cotransporter NKCC2, which allows Na+ and Cl− entry from the tubule lumen into TAL cells. In humans, mutations in the gene coding for NKCC2 result in decreased or absent activity characterized by severe salt and volume loss and decreased blood pressure (Bartter syndrome type 1). Opposite to Bartter's syndrome, enhanced NaCl absorption by the TAL is associated with human hypertension and animal models of salt-sensitive hypertension. TAL NaCl reabsorption is subject to exquisite control by hormones like vasopressin, parathyroid, glucagon, and adrenergic agonists (epinephrine and norepinephrine) that stimulate NaCl reabsorption. Atrial natriuretic peptides or autacoids like nitric oxide and prostaglandins inhibit NaCl reabsorption, promoting salt excretion. In general, the mechanism by which hormones control NaCl reabsorption is mediated directly or indirectly by altering the activity of NKCC2 in the TAL. Despite the importance of NKCC2 in renal physiology, the molecular mechanisms by which hormones, autacoids, physical factors, and intracellular ions regulate NKCC2 activity are largely unknown. During the last 5 years, it has become apparent that at least three molecular mechanisms determine NKCC2 activity. As such, membrane trafficking, phosphorylation, and protein-protein interactions have recently been described in TALs and heterologous expression systems as mechanisms that modulate NKCC2 activity. The focus of this review is to summarize recent data regarding NKCC2 regulation and discuss their potential implications in physiological control of TAL function, renal physiology, and blood pressure regulation. PMID:21900458

Heart Disease in Women: Unappreciated Challenges, GPER as a New Target.

PubMed

Feldman, Ross D

2016-05-18

Heart disease in women remains underappreciated, underdiagnosed and undertreated. Further, although we are starting to understand some of the social and behavioral determinants for this, the biological basis for the increased rate of rise in atherosclerosis risk in women after menopause remains very poorly understand. In this review we will outline the scope of the clinical issues related to heart disease in women, the emerging findings regarding the biological basis underlying the increased prevalence of atherosclerotic risk factors in postmenopausal women (vs. men) and the role of the G protein-coupled estrogen receptor (GPER) and its genetic regulation as a determinant of these sex-specific risks. GPER is a recently appreciated GPCR that mediates the rapid effects of estrogen and aldosterone. Recent studies have identified that GPER activation regulates both blood pressure. We have shown that regulation of GPER function via expression of a hypofunctional GPER genetic variant is an important determinant of blood pressure and risk of hypertension in women. Further, our most recent studies have identified that GPER activation is an important regulator of low density lipoprotein (LDL) receptor metabolism and that expression of the hypofunctional GPER genetic variant is an important contributor to the development of hypercholesterolemia in women. GPER appears to be an important determinant of the two major risk factors for coronary artery disease-blood pressure and LDL cholesterol. Further, the importance of this mechanism appears to be greater in women. Thus, the appreciation of the role of GPER function as a determinant of the progression of atherosclerotic disease may be important both in our understanding of cardiometabolic function but also in opening the way to greater appreciation of the sex-specific regulation of atherosclerotic risk factors.

77 FR 37766 - Airworthiness Directives; Bombardier, Inc. Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-25

... by reports of deformation found at the neck of the pressure regulator body on the oxygen cylinder and regulator assembly (CRA). This AD requires an inspection to determine if a certain oxygen CRA is installed and the replacement of affected oxygen CRAs. We are issuing this AD to prevent elongation of the...

Methods and apparatus of suppressing tube waves within a bore hole and seismic surveying systems incorporating same

DOEpatents

West, Phillip B.; Haefner, Daryl

2004-08-17

Methods and apparatus for attenuating waves in a bore hole, and seismic surveying systems incorporating the same. In one embodiment, an attenuating device includes a soft compliant bladder coupled to a pressurized gas source. A pressure regulating system reduces the pressure of the gas from the gas source prior to entering the bladder and operates in conjunction with the hydrostatic pressure of the fluid in a bore hole to maintain the pressure of the bladder at a specified pressure relative to the surrounding bore hole pressure. Once the hydrostatic pressure of the bore hole fluid exceeds that of the gas source, bore hole fluid may be admitted into a vessel of the gas source to further compress and displace the gas contained therein. In another embodiment, a water-reactive material may be used to provide gas to the bladder wherein the amount of gas generated by the water-reactive material may depend on the hydrostatic pressure of the bore hole fluid.

Methods and apparatus of suppressing tube waves within a bore hole and seismic surveying systems incorporating same

DOEpatents

West, Phillip B.; Haefner, Daryl

2005-12-13

Methods and apparatus for attenuating waves in a bore hole, and seismic surveying systems incorporating the same. In one embodiment, an attenuating device includes a soft compliant bladder coupled to a pressurized gas source. A pressure regulating system reduces the pressure of the gas from the gas source prior to entering the bladder and operates in conjunction with the hydrostatic pressure of the fluid in a bore hole to maintain the pressure of the bladder at a specified pressure relative to the surrounding bore hole pressure. Once the hydrostatic pressure of the bore hole fluid exceeds that of the gas source, bore hole fluid may be admitted into a vessel of the gas source to further compress and displace the gas contained therein. In another embodiment, a water-reactive material may be used to provide gas to the bladder wherein the amount of gas generated by the water-reactive material may depend on the hydrostatic pressure of the bore hole fluid.

Adaptation of aeronautical engines to high altitude flying

NASA Technical Reports Server (NTRS)

Kutzbach, K

1923-01-01

Issues and techniques relative to the adaptation of aircraft engines to high altitude flight are discussed. Covered here are the limits of engine output, modifications and characteristics of high altitude engines, the influence of air density on the proportions of fuel mixtures, methods of varying the proportions of fuel mixtures, the automatic prevention of fuel waste, and the design and application of air pressure regulators to high altitude flying. Summary: 1. Limits of engine output. 2. High altitude engines. 3. Influence of air density on proportions of mixture. 4. Methods of varying proportions of mixture. 5. Automatic prevention of fuel waste. 6. Design and application of air pressure regulators to high altitude flying.

Gut–Brain Axis in Regulation of Blood Pressure

PubMed Central

Yang, Tao; Zubcevic, Jasenka

2017-01-01

Hypertension (HTN) is an escalating health issue worldwide. It is estimated that 1.56 billion people will suffer from high blood pressure (BP) by 2025. Recent studies reported an association between gut dysbiosis and HTN, thus proposing interesting avenues for novel treatments of this condition. The sympathetic nervous system (SNS) and the immune system (IS) play a recognized role in the onset and progression of HTN, while reciprocal communication between gut microbiota and the brain can regulate BP by modulating the interplay between the IS and SNS. This review presents the current state of the science implicating brain-gut connection in HTN, highlighting potential pathways of their interaction in control of BP. PMID:29118721

Influence of the renal endothelin system on the autoregulation of renal blood flow in spontaneously hypertensive rats.

PubMed

Braun, C; Lang, C; Hocher, B; Gretz, N; van der Woude, F J; Rohmeiss, P

1997-01-01

The renal endothelin (ET) system has been claimed to play an important role in the regulation of renal blood flow (RBF) and sodium excretion in primary hypertension. The aim of the present study was to investigate the contribution of the endogenous ET system in the autoregulation of total RBF, cortical blood flow (CBF), pressure-dependent plasma renin activity (PRA) and pressure natriuresis in spontaneously hypertensive rats (SHR) by means of the combined (A/B) ET-receptor antagonist, bosentan. In anesthetized rats, RBF was measured by transit-time flow probes and CBF by laser flow probes. During the experiments, the rats received an intrarenal infusion of either bosentan (1 mg/kg/h) or vehicle. Renal perfusion pressure (RPP) was lowered in pressure steps of 5 mm Hg with a servo-controlled electropneumatic device via an inflatable suprarenal cuff. Bosentan had no effect on resting RPP, CBF, PRA and renal sodium excretion, whereas RBF was lowered by 30% (p < 0.05). Furthermore after bosentan the rats revealed a complete loss of RBF autoregulation. In contrast no changes in autoregulation of CBF, pressure-dependent PRA and pressure natriuresis were observed. Our findings demonstrate a significant impairment in total RBF autoregulatory ability during renal ET-receptor blockade which is not confined to the cortical vessels. These data suggest that the renal ET system plays an important role in the dynamic regulation of renal blood flow in SHR.

βENaC acts as a mechanosensor in renal vascular smooth muscle cells that contributes to renal myogenic blood flow regulation, protection from renal injury and hypertension.

PubMed

Drummond, Heather A; Stec, David E

2015-06-01

Pressure-induced constriction (also known as the "myogenic response") is an important mechanodependent response in small renal arteries and arterioles. The response is initiated by vascular smooth muscle cell (VSMC) stretch due to an increase in intraluminal pressure and leads to vasoconstriction. The myogenic response has two important roles as a mechanism of local blood flow autoregulation and protection against systemic blood pressure-induced microvascular damage. However, the molecular mechanisms underlying initiation of myogenic response are unresolved. Although several molecules have been considered initiators of the response, our laboratory has focused on the role of degenerin proteins because of their strong evolutionary link to mechanosensing in the nematode. Our laboratory has addressed the hypothesis that certain degenerin proteins act as mechanosensors in VSMCs. This article discusses the importance of a specific degenerin protein, β Epithelial Na + Channel (βENaC), in pressure-induced vasoconstriction, renal blood flow and susceptibility to renal injury. We propose that loss of the renal myogenic constrictor response delays the correction of renal blood flow that occurs with fluctuations in systemic pressure, which allows pressure swings to be transmitted to the microvasculature, thus increasing the susceptibility to renal injury and hypertension. The role of βENaC in myogenic regulation is independent of tubular βENaC and thus represents a non-tubular role for βENaC in renal-cardiovascular homeostasis.

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.

75 FR 13 - Alternate Fracture Toughness Requirements for Protection Against Pressurized Thermal Shock Events

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-04

...The Nuclear Regulatory Commission (NRC) is amending its regulations to provide alternate fracture toughness requirements for protection against pressurized thermal shock (PTS) events for pressurized water reactor (PWR) pressure vessels. This final rule provides alternate PTS requirements based on updated analysis methods. This action is desirable because the existing requirements are based on unnecessarily conservative probabilistic fracture mechanics analyses. This action reduces regulatory burden for those PWR licensees who expect to exceed the existing requirements before the expiration of their licenses, while maintaining adequate safety, and may choose to comply with the final rule as an alternative to complying with the existing requirements.

Controlled hydrostatic pressure stress downregulates the expression of ribosomal genes in preimplantation embryos: a possible protection mechanism?

PubMed

Bock, I; Raveh-Amit, H; Losonczi, E; Carstea, A C; Feher, A; Mashayekhi, K; Matyas, S; Dinnyes, A; Pribenszky, C

2016-04-01

The efficiency of various assisted reproductive techniques can be improved by preconditioning the gametes and embryos with sublethal hydrostatic pressure treatment. However, the underlying molecular mechanism responsible for this protective effect remains unknown and requires further investigation. Here, we studied the effect of optimised hydrostatic pressure treatment on the global gene expression of mouse oocytes after embryonic genome activation. Based on a gene expression microarray analysis, a significant effect of treatment was observed in 4-cell embryos derived from treated oocytes, revealing a transcriptional footprint of hydrostatic pressure-affected genes. Functional analysis identified numerous genes involved in protein synthesis that were downregulated in 4-cell embryos in response to hydrostatic pressure treatment, suggesting that regulation of translation has a major role in optimised hydrostatic pressure-induced stress tolerance. We present a comprehensive microarray analysis and further delineate a potential mechanism responsible for the protective effect of hydrostatic pressure treatment.

Understanding the external pressure and behavior of commercial banks' environmental risk management: an empirical study undertaken in the Yangtze River delta of China.

PubMed

Liu, Yong; Lin, Zhongguo

2014-04-01

The present study employed a quantitative survey to ascertain whether the external pressure of environmental risk management (ERM) on commercial banks was a contributing factor to their ERM behavior. Data was obtained using questionnaires from 204 branches of commercial banks located in the Yangtze River Delta of China. The relationship between external pressure and behavior was tested using a linear structural relations model through path analysis. The results revealed that external pressure of ERM was significantly and positively related to the behavior and that pressure from governmental regulations was the most important contributing factor in the passive feedback behavior and preventive behavior of commercial banks. The pressure from markets was the most important contributing factor in banks' active participation behavior; the pressure from community and NGOs was the most important contributing factor in their enthusiastic behavior.

[Having trouble with pressure ulcers care?].

PubMed

Mizuno, Masako; Noda, Yasuhiro; Nohara, Yoko; Fujii, Keiko; Sato, Noriko; Renda, Akiyoshi; Yuasa, Takashi; Muramatsu, Shuichi; Furuta, Katsunori

2004-12-01

Since 1997, we, the community pharmacists, have established this society, Aichi Prefecture Society for the Study of Pressure Ulcers Care, in order to furnish drug information about pressure ulcers care. Moist atmosphere is required for the healing of pressure ulcers. The moist environment that could be regulated depends on the physicochemical property of ointment bases. Therefore, ointment should reasonably be chosen to adjust the moisture. Since 2000, we have been committed to providing pharmacists, who work on home care, with a booklet to instruct how to choose ointments for pressure ulcers treatment. In 2002, when the Aichi pharmaceutical association held a training conference held at various hospitals using the booklet as a teaching material, hospital pharmacists cooperated by making a field study trip to observe pressure ulcers treatments. Nowadays researchers at pharmaceutical colleges have also cooperated in studying the efficacy and economical effect of the method of blending different ointments to improve the healing process of pressure ulcers.

Low-Pressure Long-Term Xenon Storage for Electric Propulsion

NASA Technical Reports Server (NTRS)

Back, Dwight D.; Ramos, Charlie; Meyer, John A.

2001-01-01

This Phase 2 effort demonstrated an alternative Xe storage and regulation system using activated carbon (AC) as a secondary storage media (ACSFR). This regulator system is nonmechanical, simple, inexpensive, and lighter. The ACSFR system isolates the thruster from the compressed gas tank, and allows independent multiple setpoint thruster operation. The flow using an ACSFR can also be throttled by applying increments in electrical power. Primary storage of Xe by AC is not superior to compressed gas storage with regard to weight, but AC storage can provide volume reduction, lower pressures in space, and potentially in situ Xe purification. With partial fill designs, a primary AC storage vessel for Xe could also eliminate problems with two-phase storage and regulate pressure. AC could also be utilized in long-term large quantity storage of Xe serving as a compact capture site for boil-off. Several Xe delivery ACSFR protocols between 2 and 45 sccm, and 15 min to 7 hr, were tested with an average flow variance of 1.2 percent, average power requirements of 5 W, and repeatability s of about 0.4 percent. Power requirements are affected by ACSFR bed sizing and flow rate/ duration design points, and these flow variances can be reduced by optimizing PID controller parameters.

49 CFR 179.200-13 - Manway ring or flange, pressure relief device flange, bottom outlet nozzle flange, bottom washout...

Code of Federal Regulations, 2010 CFR

2010-10-01

... HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS SPECIFICATIONS FOR TANK CARS Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179..., figure 10, of the AAR Specifications for Tank Cars (IBR, see § 171.7 of this subchapter). (b) The opening...

30 CFR 250.519 - How often do I have to monitor for casing pressure?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 2 2011-07-01 2011-07-01 false How often do I have to monitor for casing pressure? 250.519 Section 250.519 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION, AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Well-Completion...

Application of Acute Maximal Exercise to Enhance Mechanisms Underlying Blood Pressure Regulation and Orthostatic Tolerance After Exposure to Simulated Microgravity

NASA Technical Reports Server (NTRS)

Convertino, V. A.; Engelke, K. A.; Doerr, D. F.

1999-01-01

Development of orthostatic hypotension and intolerance in astronauts who return to earth following a spaceflight mission represents a significant operational concern to NASA. Reduced plasma volume, vascular resistance, and baroreflex responsiveness following exposure to actual and ground-based analogs of microgravity have been associated with orthostatic instability, suggesting that these mechanisms may contribute alone or in combination to compromise of blood pressure regulation after spaceflight. It therefore seems reasonable that development of procedures designed to reverse or restore the effects of microgravity on regulatory mechanisms of blood volume, vascular resistance and cardiac function should provide some protection against postflight orthostatic intolerance. Several investigations have provided evidence that a single bout of exhaustive dynamic exercise enhances functions of mechanisms responsible for blood pressure stability. Therefore, the purpose of our research project was to conduct a series of experiments using ground-based analogs of reduced gravity (i.e., prolonged restriction to the upright standing posture) in human subjects to investigate the hypothesis that a single bout of dynamic maximal exercise would restore blood volume, vascular resistance and cardiac function and improve blood pressure stability.

The control of microvascular permeability and blood pressure by neutral endopeptidase.

PubMed

Lu, B; Figini, M; Emanueli, C; Geppetti, P; Grady, E F; Gerard, N P; Ansell, J; Payan, D G; Gerard, C; Bunnett, N

1997-08-01

Plasma extravasation from postcapillary venules is one of the earliest steps of inflammation. Substance P (SP) and bradykinin (BK) mediate extravasation and cause hypotension. The cell-surface enzyme neutral endopeptidase (NEP) inactivates both peptides. Thus, absence of NEP may predispose development of inflammation and hypotension. We examined these possibilities in mice in which the NEP gene was deleted by homologous recombination. There was widespread basal plasma extravasation in postcapillary venular endothelia in NEP-/- mice, which was reversed by recombinant NEP and antagonists of SP (NK1) and BK (B2) receptors. Mean arterial blood pressure was 20% lower in NEP-/- animals, but this was unaffected by reintroduction of recombinant NEP and the kinin receptor antagonists. The hypotension was also independent of nitric oxide (NO), because NEP-/- mice treated with a NO synthase inhibitor remained hypotensive relative to the wild type. Thus, NEP has important roles in regulating basal microvascular permeability by degrading SP and BK, and may regulate blood pressure set point through a mechanism that is independent of SP, BK and NO. The use of NEP antagonists as candidate drugs in cardiovascular disease is suggested by the blood pressure data reported herein.

Endocannabinoids Acting at Cannabinoid-1 Receptors Regulate Cardiovascular Function in Hypertension

PubMed Central

Bátkai, Sándor; Pacher, Pál; Osei-Hyiaman, Douglas; Radaeva, Svetlana; Liu, Jie; Harvey-White, Judith; Offertáler, László; Mackie, Ken; Audrey Rudd, M.; Bukoski, Richard D.; Kunos, George

2009-01-01

Background Endocannabinoids are novel lipid mediators with hypotensive and cardiodepressor activity. Here, we examined the possible role of the endocannabinergic system in cardiovascular regulation in hypertension. Methods and Results In spontaneously hypertensive rats (SHR), cannabinoid-1 receptor (CB1) antagonists increase blood pressure and left ventricular contractile performance. Conversely, preventing the degradation of the endocannabinoid anandamide by an inhibitor of fatty acid amidohydrolase reduces blood pressure, cardiac contractility, and vascular resistance to levels in normotensive rats, and these effects are prevented by CB1 antagonists. Similar changes are observed in 2 additional models of hypertension, whereas in normotensive control rats, the same parameters remain unaffected by any of these treatments. CB1 agonists lower blood pressure much more in SHR than in normotensive Wistar-Kyoto rats, and the expression of CB1 is increased in heart and aortic endothelium of SHR compared with Wistar-Kyoto rats. Conclusions We conclude that endocannabinoids tonically suppress cardiac contractility in hypertension and that enhancing the CB1-mediated cardiodepressor and vasodilator effects of endogenous anandamide by blocking its hydrolysis can normalize blood pressure. Targeting the endocannabinoid system offers novel therapeutic strategies in the treatment of hypertension. PMID:15451779

Low-temperature overpressurization protection system setpoint analysis using RETRAN-02/MOD5 for Salem

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dodson, R.J.; Feltus, M.A.

The low-temperature overpressurization protection system (LTOPS) is designed to protect the reactor pressure vessel (RPV) from brittle failure during startup and cooldown maneuvers in Westinghouse pressurized water reactors. For the Salem power plants, the power-operated relief valves (PORVs) mitigate pressure increases above a setpoint where an operational startup transient may put the RPV in the embrittlement fracture zone. The Title 10, Part 50, Code of Federal Regulations Appendix G limit, given by plant technical specifications, conservatively bounds the maximum pressure allowed during those transients where the RPV can suffer brittle fracture (usually below 350{degrees}F). The Appendix G limit is amore » pressure versus temperature curve that is more restrictive at lower RPV temperatures and allows for higher pressures as the temperature approaches the upper bounding fracture temperature.« less

Smooth Muscle Ion Channels and Regulation of Vascular Tone in Resistance Arteries and Arterioles

PubMed Central

Tykocki, Nathan R.; Boerman, Erika M.; Jackson, William F.

2017-01-01

Vascular tone of resistance arteries and arterioles determines peripheral vascular resistance, contributing to the regulation of blood pressure and blood flow to, and within the body’s tissues and organs. Ion channels in the plasma membrane and endoplasmic reticulum of vascular smooth muscle cells (SMCs) in these blood vessels importantly contribute to the regulation of intracellular Ca2+ concentration, the primary determinant of SMC contractile activity and vascular tone. Ion channels provide the main source of activator Ca2+ that determines vascular tone, and strongly contribute to setting and regulating membrane potential, which, in turn, regulates the open-state-probability of voltage gated Ca2+ channels (VGCCs), the primary source of Ca2+ in resistance artery and arteriolar SMCs. Ion channel function is also modulated by vasoconstrictors and vasodilators, contributing to all aspects of the regulation of vascular tone. This review will focus on the physiology of VGCCs, voltage-gated K+ (KV) channels, large-conductance Ca2+-activated K+ (BKCa) channels, strong-inward-rectifier K+ (KIR) channels, ATP-sensitive K+ (KATP) channels, ryanodine receptors (RyRs), inositol 1,4,5-trisphosphate receptors (IP3Rs), and a variety of transient receptor potential (TRP) channels that contribute to pressure-induced myogenic tone in resistance arteries and arterioles, the modulation of the function of these ion channels by vasoconstrictors and vasodilators, their role in the functional regulation of tissue blood flow and their dysfunction in diseases such as hypertension, obesity, and diabetes. PMID:28333380

Mathematical Model of the Jet Engine Fuel System

NASA Astrophysics Data System (ADS)

Klimko, Marek

2015-05-01

The paper discusses the design of a simplified mathematical model of the jet (turbo-compressor) engine fuel system. The solution will be based on the regulation law, where the control parameter is a fuel mass flow rate and the regulated parameter is the rotational speed. A differential equation of the jet engine and also differential equations of other fuel system components (fuel pump, throttle valve, pressure regulator) will be described, with respect to advanced predetermined simplifications.

Effects of whole body heating on dynamic baroreflex regulation of heart rate in humans

NASA Technical Reports Server (NTRS)

Crandall, C. G.; Zhang, R.; Levine, B. D.

2000-01-01

The purpose of this project was to identify whether dynamic baroreflex regulation of heart rate (HR) is altered during whole body heating. In 14 subjects, dynamic baroreflex regulation of HR was assessed using transfer function analysis. In normothermic and heat-stressed conditions, each subject breathed at a fixed rate (0. 25 Hz) while beat-by-beat HR and systolic blood pressure (SBP) were obtained. Whole body heating significantly increased sublingual temperature, HR, and forearm skin blood flow. Spectral analysis of HR and SBP revealed that the heat stress significantly reduced HR and SBP variability within the high-frequency range (0.2-0.3 Hz), reduced SBP variability within the low-frequency range (0.03-0.15 Hz), and increased the ratio of low- to high-frequency HR variability (all P < 0.01). Transfer function gain analysis showed that the heat stress reduced dynamic baroreflex regulation of HR within the high-frequency range (from 1.04 +/- 0.06 to 0.54 +/- 0.6 beats. min(-1). mmHg(-1); P < 0.001) without significantly affecting the gain in the low-frequency range (P = 0.63). These data suggest that whole body heating reduced high-frequency dynamic baroreflex regulation of HR associated with spontaneous changes in blood pressure. Reduced vagal baroreflex regulation of HR may contribute to reduced orthostatic tolerance known to occur in humans during heat stress.

Analyzing Gene Expression Profiles with Preliminary Validations in Cardiac Hypertrophy Induced by Pressure-overload.

PubMed

Gao, Jing; Li, Yuhong; Wang, Tongmei; Shi, Zhuo; Zhang, Yiqi; Liu, Shuang; Wen, Pushuai; Ma, Chunyan

2018-03-06

The aim of this study was to identify the key genes involved in the cardiac hypertrophy (CH) induced by pressure overload. mRNA microarray dataset GSE5500 and GSE18801 were downloaded from GEO database, and differentially expressed genes (DEGs) were screened using Limma package; then, functional and pathway enrichment analysis were performed for common DEGs using DAVID database. Furthermore, the top DEGs were further validated using qPCR in the hypertrophic heart tissue induced by Isoprenaline (ISO). A total of 113 common DEGs with absolute fold change >0.5, including 60 significantly up-regulated DEGs and 53 down-regulated DEGs were obtained. GO term enrichment analysis suggested that common up-regulated DEG mainly enriched in neutrophil chemotaxis, extracellular fibril organization and cell proliferation, and the common down-regulated genes were significantly enriched in ion transport, endoplasmic reticulum and dendritic spine. KEGG pathway analysis found that the common DEGs were mainly enriched in ECM-receptor interaction, phagosome, and focal adhesion. Additionally, the expression of Mfap4, Ltbp2, Aspn, Serpina3n, and Cnksr1 were up-regulated in the model of cardiac hypertrophy, while the expression of Anp32a was down-regulated. The current study identified the key deregulated genes and pathways involved in the CH, which could shed new light to understand the mechanism of CH.

Capacity, pressure, demand, and flow: A conceptual framework for analyzing ecosystem service provision and delivery

USGS Publications Warehouse

Villamagna, Amy M.; Angermeier, Paul L.; Bennett, Elena M.

2013-01-01

Ecosystem services provide an instinctive way to understand the trade-offs associated with natural resource management. However, despite their apparent usefulness, several hurdles have prevented ecosystem services from becoming deeply embedded in environmental decision-making. Ecosystem service studies vary widely in focal services, geographic extent, and in methods for defining and measuring services. Dissent among scientists on basic terminology and approaches to evaluating ecosystem services create difficulties for those trying to incorporate ecosystem services into decision-making. To facilitate clearer comparison among recent studies, we provide a synthesis of common terminology and explain a rationale and framework for distinguishing among the components of ecosystem service delivery, including: an ecosystem's capacity to produce services; ecological pressures that interfere with an ecosystem's ability to provide the service; societal demand for the service; and flow of the service to people. We discuss how interpretation and measurement of these four components can differ among provisioning, regulating, and cultural services. Our flexible framework treats service capacity, ecological pressure, demand, and flow as separate but interactive entities to improve our ability to evaluate the sustainability of service provision and to help guide management decisions. We consider ecosystem service provision to be sustainable when demand is met without decreasing capacity for future provision of that service or causing undesirable declines in other services. When ecosystem service demand exceeds ecosystem capacity to provide services, society can choose to enhance natural capacity, decrease demand and/or ecological pressure, or invest in a technological substitute. Because regulating services are frequently overlooked in environmental assessments, we provide a more detailed examination of regulating services and propose a novel method for quantifying the flow of regulating services based on estimates of ecological work. We anticipate that our synthesis and framework will reduce inconsistency and facilitate coherence across analyses of ecosystem services, thereby increasing their utility in environmental decision-making.

ANF-RGC gene motif 669WTAPELL675 is vital for blood pressure regulation: Biochemical mechanism

PubMed Central

Duda, Teresa; Pertzev, Alexandre; Sharma, Rameshwar K.

2013-01-01

ANF-RGC is the prototype membrane guanylate cyclase, both the receptor and the signal transducer of the hormones ANF and BNP. After binding them at the extracellular domain it, at its intracellular domain, signals activation of the C-terminal catalytic module and accelerates production of the second messenger, cyclic GMP. This, in turn, controls the physiological processes of blood pressure, cardiovascular function, and fluid secretion, and others: metabolic syndrome, obesity and apoptosis. What is the biochemical mechanism by which this single molecule controls these diverse processes, explicitly of the blood pressure regulation is the subject of the present study. In line with the concept that the structural modules of ANF-RGC are designed to respond to more than one, yet distinctive signals, the study demonstrates the construction of a novel ANF-RGC-In-gene-669WTAPELL675 mouse model. Through this model, the study establishes that 669WTAPELL675 is a vital ANF signal transducer motif of the guanylate cyclase. Its striking physiological features linked with their biochemistry are that (1) it controls the hormonally-dependent cyclic GMP production in the kidney and the adrenal gland; (3) its deletion causes hypertension, and (3) cardiac hypertrophy; and (4) these mice show higher levels of the plasma aldosterone. For the first time, a mere 7-amino acid encoded motif of the mouse gene has been directly linked with the physiological control of the blood pressure regulation, a detailed biochemistry of this linkage has been established and a model for this linkage has been offered. PMID:23464624

Caffeic acid phenethyl ester attenuates pathological cardiac hypertrophy by regulation of MEK/ERK signaling pathway in vivo and vitro.

PubMed

Ren, Jie; Zhang, Nan; Liao, Haihan; Chen, Si; Xu, Ling; Li, Jing; Yang, Zheng; Deng, Wei; Tang, Qizhu

2017-07-15

To explore the effects of caffeic acid phenethyl ester (CAPE) on cardiac hypertrophy induced by pressure overload. Male wild-type C57 mice, aged 8-10weeks, were used for aortic banding (AB) to induce cardiac hypertrophy. CAPE or (resveratrol) RS was administered from the 3rd day after AB surgery for 6weeks. Echocardiography and hemodynamic analysis were performed to estimate cardiac function. Mice hearts were collected for H&E and PSR staining. Western blot analysis and quantitative PCR were performed for to investigate molecular mechanism. We further confirmed our findings in H9c2 cardiac fibroblasts treated with PE or CAPE. CAPE protected against cardiac hypertrophy induced by pressure overload, as evidenced by inhibition of cardiac hypertrophy and improvement in mouse cardiac function. The effect of CAPE on cardiac hypertrophy was mediated via inhibition of the MEK/ERK and TGFβ-Smad signaling pathways. We also demonstrated that CAPE protected H9c2 cells from PE-induced hypertrophy in vitro via a similar molecular mechanism as seen in the mouse heart. Finally, CAPE seemed to be as effective as RS for treatment of pressure overload induced mouse cardiac hypertrophy. Our results suggest that CAPE may play an important role in the regulation of cardiac hypertrophy induced by pressure overload via negative regulation of the MEK/ERK and TGFβ/Smad signaling pathways. These results indicate that CAPE could potentially be used for treatment of cardiac hypertrophy. Copyright © 2017 Elsevier Inc. All rights reserved.

Food and drug administration regulation of drugs that raise blood pressure.

PubMed

Blankfield, Robert P; Iftikhar, Imran H

2015-01-01

Although it is recognized that a systolic blood pressure (SBP) increase ≥ 2 mm Hg or a diastolic blood pressure (DBP) increase ≥ 1 mm Hg increases the risk of heart attacks and strokes in middle-aged adults, the Food and Drug Administration (FDA) lacks an adequate policy for regulating medications that increase blood pressure (BP). Some FDA reviewers consider a clinically significant increase in BP to occur only if a drug raises SBP ≥ 20 mm Hg or if a drug raises DBP ≥ 10 to 15 mm Hg. In recent years, numerous drugs have been regulated or taken off the market due to cardiovascular safety concerns. The list includes rofecoxib (Vioxx), valdecoxib (Bextra), nonselective nonsteroidal anti-inflammatory drugs, sibutramine (Meridia), and phenylpropanolamine. It is probable that the hypertensive effect of these drugs explains why they increase the risk of adverse cardiovascular events. Other drugs, notably serotonin-norepinephrine reuptake inhibitors and drugs used to treat attention deficit hyperactivity disorder, were approved without cardiovascular safety data despite the fact that they raise BP comparable to valdecoxib and sibutramine. It is the responsibility of the FDA to ensure that drugs are properly labeled regarding risk. Even if a drug raises BP only modestly, FDA guidelines for new drug approvals should include a requirement for cardiovascular safety data. However, such guidelines will not address the problem of how to obtain cardiovascular safety data for the many already approved drugs that increase BP. The FDA should play a role in obtaining cardiovascular safety data for such drugs. © The Author(s) 2014.

Quorum sensing molecules in activated sludge could trigger microalgae lipid synthesis.

PubMed

Zhang, Chaofan; Li, Qingcheng; Fu, Liang; Zhou, Dandan; Crittenden, John C

2018-05-18

Cultivating microalgae using wastewater is an economical strategy to produce biofuel; however, microbial contamination has to be controlled strictly. Microalgae lipid accumulation can be triggered by environmental pressures, and here, we studied whether microbial contamination is the pressure for microalgae. We hypothesized this pressure was forced via cell-to-cell communication with quorum sensing molecules (QSMs). In this work, we verified the impacts of QSMs produced by activated sludge (wastewater-born microbial consortiums) on both lipid content and biomass production of the microalgae Chlorophyta sp., since in combination, they determined lipid productivity. With QSMs stress, the lipid content of Chlorophyta sp. increased by ∼84%, while biomass production decreased only slightly. Consistently, enzymes on the fatty acid synthesis pathways were generally up-regulated, while they were slightly down-regulated for DNA replication. In summary, the total lipid production improved by 86%. These results revealed the positive effects of microbial contamination on microalgae biofuel production. Copyright © 2018 Elsevier Ltd. All rights reserved.

CooLN2Car: An Experimental Car Which Uses Liquid Nitrogen as Its Fuel

NASA Astrophysics Data System (ADS)

Parker, M. E.; Plummer, M. C.; Ordonez, C. A.

1997-10-01

A ``cryogenic" heat engine which operates using the atmosphere as a heat source and a cryogenic medium as a heat sink has been incorporated as the power system for an automobile. A 1973 Volkswagen Beetle has been converted and uses liquid nitrogen as its ``fuel." A Dewar was mounted in the car and provides nitrogen under pressure to two heat exchangers connected in parallel which use atmospheric heat to heat the nitrogen. The heat exchangers deliver compressed nitrogen gas to a vane-type pneumatic motor mounted in place of the original gasoline engine. Pressure in the tank is maintained internally at 1.2 MPa and is reduced to 0.7 MPa before the motor by a pressure regulator. A throttle, composed of a butterfly valve, is mounted between the regulator and the motor and is connected to the driver's accelerator peddle. The vehicle has good acceleration, a maximum range of 15 miles, and a maximum speed of 25 mph. A demonstration with the vehicle is planned.

The measurement of Eustachian tube function in a hyperbaric chamber using an ear canal microphone.

PubMed

Fischer, Hans-Georg; Koch, Andreas; Kähler, Wataru; Pohl, Michael; Pau, Hans-Wilhelm; Zehlicke, Thorsten

2016-03-01

The purpose of this study was to further the understanding of the opening of the Eustachian tube in relation to changes in barometric pressure. An ear canal microphone was used to measure the specific sounds related to tube opening and possible eardrum movements. Five subjects with normal tube function were examined in a hyperbaric chamber (up to 304 kPa). All active and passive equalization events were recorded and correlated with the subjectively perceived pressure regulation in the measured ear. The signals recorded were clear and reproducible. The acoustic analysis distinguished between the different kinds of equalization. Subjective impressions were confirmed by the recorded frequency of acoustic phenomena (clicks). During compression, the sequence of active equalization manoeuvres was in a more regular and steady pattern than during decompression, when the click sounds varied. The study established a simple technical method for analyzing the function of the Eustachian tube and provided new information about barometric pressure regulation of the middle ear.

Cystathionine γ-Lyase-Produced Hydrogen Sulfide Controls Endothelial NO Bioavailability and Blood Pressure.

PubMed

Szijártó, István András; Markó, Lajos; Filipovic, Milos R; Miljkovic, Jan Lj; Tabeling, Christoph; Tsvetkov, Dmitry; Wang, Ning; Rabelo, Luiza A; Witzenrath, Martin; Diedrich, André; Tank, Jens; Akahoshi, Noriyuki; Kamata, Shotaro; Ishii, Isao; Gollasch, Maik

2018-06-01

Hydrogen sulfide (H 2 S) and NO are important gasotransmitters, but how endogenous H 2 S affects the circulatory system has remained incompletely understood. Here, we show that CTH or CSE (cystathionine γ-lyase)-produced H 2 S scavenges vascular NO and controls its endogenous levels in peripheral arteries, which contribute to blood pressure regulation. Furthermore, eNOS (endothelial NO synthase) and phospho-eNOS protein levels were unaffected, but levels of nitroxyl were low in CTH-deficient arteries, demonstrating reduced direct chemical interaction between H 2 S and NO. Pretreatment of arterial rings from CTH-deficient mice with exogenous H 2 S donor rescued the endothelial vasorelaxant response and decreased tissue NO levels. Our discovery that CTH-produced H 2 S inhibits endogenous endothelial NO bioavailability and vascular tone is novel and fundamentally important for understanding how regulation of vascular tone is tailored for endogenous H 2 S to contribute to systemic blood pressure function. © 2018 American Heart Association, Inc.

Skeletal Muscle Pump Drives Control of Cardiovascular and Postural Systems

NASA Astrophysics Data System (ADS)

Verma, Ajay K.; Garg, Amanmeet; Xu, Da; Bruner, Michelle; Fazel-Rezai, Reza; Blaber, Andrew P.; Tavakolian, Kouhyar

2017-03-01

The causal interaction between cardio-postural-musculoskeletal systems is critical in maintaining postural stability under orthostatic challenge. The absence or reduction of such interactions could lead to fainting and falls often experienced by elderly individuals. The causal relationship between systolic blood pressure (SBP), calf electromyography (EMG), and resultant center of pressure (COPr) can quantify the behavior of cardio-postural control loop. Convergent cross mapping (CCM) is a non-linear approach to establish causality, thus, expected to decipher nonlinear causal cardio-postural-musculoskeletal interactions. Data were acquired simultaneously from young participants (25 ± 2 years, n = 18) during a 10-minute sit-to-stand test. In the young population, skeletal muscle pump was found to drive blood pressure control (EMG → SBP) as well as control the postural sway (EMG → COPr) through the significantly higher causal drive in the direction towards SBP and COPr. Furthermore, the effect of aging on muscle pump activation associated with blood pressure regulation was explored. Simultaneous EMG and SBP were acquired from elderly group (69 ± 4 years, n = 14). A significant (p = 0.002) decline in EMG → SBP causality was observed in the elderly group, compared to the young group. The results highlight the potential of causality to detect alteration in blood pressure regulation with age, thus, a potential clinical utility towards detection of fall proneness.

Erythropoiesis and Blood Pressure Are Regulated via AT1 Receptor by Distinctive Pathways.

PubMed

Kato, Hideki; Ishida, Junji; Matsusaka, Taiji; Ishimaru, Tomohiro; Tanimoto, Keiji; Sugiyama, Fumihiro; Yagami, Ken-Ichi; Nangaku, Masaomi; Fukamizu, Akiyoshi

2015-01-01

The renin-angiotensin system (RAS) plays a central role in blood pressure regulation. Although clinical and experimental studies have suggested that inhibition of RAS is associated with progression of anemia, little evidence is available to support this claim. Here we report that knockout mice that lack angiotensin II, including angiotensinogen and renin knockout mice, exhibit anemia. The anemia of angiotensinogen knockout mice was rescued by angiotensin II infusion, and rescue was completely blocked by simultaneous administration of AT1 receptor blocker. To genetically determine the responsible receptor subtype, we examined AT1a, AT1b, and AT2 knockout mice, but did not observe anemia in any of them. To investigate whether pharmacological AT1 receptor inhibition recapitulates the anemic phenotype, we administered AT1 receptor antagonist in hypotensive AT1a receptor knockout mice to inhibit the remaining AT1b receptor. In these animals, hematocrit levels barely decreased, but blood pressure further decreased to the level observed in angiotensinogen knockout mice. We then generated AT1a and AT1b double-knockout mice to completely ablate the AT1 receptors; the mice finally exhibited the anemic phenotype. These results provide clear evidence that although erythropoiesis and blood pressure are negatively controlled through the AT1 receptor inhibition in vivo, the pathways involved are complex and distinct, because erythropoiesis is more resistant to AT1 receptor inhibition than blood pressure control.

No Elevated Plasma Catecholamine Levels during Sleep in Newly Diagnosed, Untreated Hypertensives

PubMed Central

Rasch, Björn; Dodt, Christoph; Sayk, Friedhelm; Mölle, Matthias; Born, Jan

2011-01-01

The sympatho-adrenergic system is highly involved in regulating sleep, wake and arousal states, and abnormalities in this system are regarded as a key factor in the development and progression of arterial hypertension. While hypertension is associated with a hyperadrenergic state during wakefulness, the effect of hypertension on plasma-catecholamine levels during sleep is not yet known. Twelve young participants with newly diagnosed, untreated hypertension and twelve healthy controls slept for 7 hours in the sleep laboratory. Before and after sleep, subjects rested in a supine position for 3-h periods of wakefulness. We sampled blood at a fast rate (1/10 min) and monitored blood pressure and heart rate continuously. We show that plasma NE and E levels did not differ between hypertensives and normotensive during sleep as well as before and after sleep. Blood pressure was higher in hypertensives, reaching the largest group difference in the morning after sleep. Unlike in the normotensives, in the hypertensive participants the morning rise in blood pressure did not correlate with the rise in catecholamine levels at awakening. Our results suggest that hypertension in its early stages is not associated with a strong hyperadrenergic state during sleep. In showing a diminished control of blood pressure through sympatho-adrenergic signals in hypertensive participants, our data point towards a possible involvement of dysfunctional sleep-related blood pressure regulation in the development of hypertension. PMID:21695061

Decision making and effort in the self-regulation of hypertension: testing two competing theories.

PubMed

Taylor, Stephanie D; Bagozzi, Richard P; Gaither, Caroline A

2005-11-01

We compare the ability of two social psychological models to explain self-regulation decisions to control hypertension by 208 patients at a hospital clinic: the theory of planned behaviour (TPB) and the model of goal-directed behaviour (MGB). The sample was drawn from patients at a large research hospital in North America. The findings show that the MGB not only explains significantly more variance in decision making than the TPB, but it provides an account for how reasons for acting become integrated and transformed into intentions to act, which the TPB does not address. The MGB does this in part by introducing the variable, desire, as an essential mediator between reasons for acting and intentions. The MGB also incorporates the effects of anticipated emotions on decision making, which are forms of forward-looking counterfactual thinking with respect to goals. In addition, the present study reconceptualized instrumental behaviour to encompass how hard one tries to act in the senses of (1) devoting time to planning with respect to reducing/maintaining blood pressure, (2) expending mental/physical energy to reduce/maintain blood pressure, (3) maintaining will power to reduce/maintain blood pressure, and (4) sustaining self-discipline (e.g. in overcoming obstacles) to reduce/maintain blood pressure. Key differences, as well as commonalities, in decision making are pointed-out between men and women and between people whose goal is to reduce versus maintain blood pressure.

Extracellular signal-regulated kinase (ERK) activation preserves cardiac function in pressure overload induced hypertrophy.

PubMed

Mutlak, Michael; Schlesinger-Laufer, Michal; Haas, Tali; Shofti, Rona; Ballan, Nimer; Lewis, Yair E; Zuler, Mor; Zohar, Yaniv; Caspi, Lilac H; Kehat, Izhak

2018-05-24

Chronic pressure overload and a variety of mediators induce concentric cardiac hypertrophy. When prolonged, cardiac hypertrophy culminates in decreased myocardial function and heart failure. Activation of the extracellular signal-regulated kinase (ERK) is consistently observed in animal models of hypertrophy and in human patients, but its role in the process is controversial. We generated transgenic mouse lines with cardiomyocyte restricted overexpression of intrinsically active ERK1, which similar to the observations in hypertrophy is phosphorylated on both the TEY and the Thr207 motifs and is overexpressed at pathophysiological levels. The activated ERK1 transgenic mice developed a modest adaptive hypertrophy with increased contractile function and without fibrosis. Following induction of pressure-overload, where multiple pathways are stimulated, this activation did not further increase the degree of hypertrophy but protected the heart through a decrease in the degree of fibrosis and maintenance of ventricular contractile function. The ERK pathway acts to promote a compensated hypertrophic response, with enhanced contractile function and reduced fibrosis. The activation of this pathway may be a therapeutic strategy to preserve contractile function when the pressure overload cannot be easily alleviated. The inhibition of this pathway, which is increasingly being used for cancer therapy on the other hand, should be used with caution in the presence of pressure-overload. Copyright © 2017. Published by Elsevier B.V.

Nonlinear aspects of infrasonic pressure transfer into the perilymph.

PubMed

Krukowski, B; Carlborg, B; Densert, O

1980-06-01

The perilymphatic pressure was studied in response to various low frequency pressure changes in the ear canal. The pressure transfer was analysed and found to be nonlinear in many aspects. The pressure response was found to contain two time constants representing the inner ear pressure regulating mechanisms. The time constants showed an asymmetry in response to positive and negative going inputs--the effects to some extent proportional to input levels. Further nonlinearities were found when infrasonic sine waves were applied to the ear. Harmonic distortion and modulation appeared. When short bursts of infrasound were introduced a clear d.c. shift was observed as a consequence of an asymmetry in the response to positive and negative going pressure inputs. A temporary change in mean perilymphatic pressure was thus achieved and continued throughout the duration of the signal. At very low frequencies a distinct phase shift was detected in the sine waves. This appeared as a phase lead, breaking the continuity of the output sine wave.

Blood-Pressure Measuring System Gives Accurate Graphic Output

NASA Technical Reports Server (NTRS)

1965-01-01

The problem: To develop an instrument that will provide an external (indirect) measurement of arterial blood pressure in the form of an easily interpreted graphic trace that can be correlated with standard clinical blood-pressure measurements. From sphygmograms produced by conventional sphygmographs, it is very difficult to differentiate the systolic and diastolic blood-pressure pulses and to correlate these indices with the standard clinical values. It is nearly impossible to determine these indices when the subject is under physical or emotional stress. The solution: An electronic blood-pressure system, basically similar to conventional ausculatory sphygmomanometers, employing a standard occluding cuff, a gas-pressure source, and a gas-pressure regulator and valve. An electrical output transducer senses cuff pressure, and a microphone positioned on the brachial artery under the occluding cuff monitors the Korotkoff sounds from this artery. The output signals present the conventional systolic and diastolic indices in a clear, graphical display. The complete system also includes an electronic timer and cycle-control circuit.

Cuff-Free Blood Pressure Estimation Using Pulse Transit Time and Heart Rate.

PubMed

Wang, Ruiping; Jia, Wenyan; Mao, Zhi-Hong; Sclabassi, Robert J; Sun, Mingui

2014-10-01

It has been reported that the pulse transit time (PTT), the interval between the peak of the R-wave in electrocardiogram (ECG) and the fingertip photoplethysmogram (PPG), is related to arterial stiffness, and can be used to estimate the systolic blood pressure (SBP) and diastolic blood pressure (DBP). This phenomenon has been used as the basis to design portable systems for continuously cuff-less blood pressure measurement, benefiting numerous people with heart conditions. However, the PTT-based blood pressure estimation may not be sufficiently accurate because the regulation of blood pressure within the human body is a complex, multivariate physiological process. Considering the negative feedback mechanism in the blood pressure control, we introduce the heart rate (HR) and the blood pressure estimate in the previous step to obtain the current estimate. We validate this method using a clinical database. Our results show that the PTT, HR and previous estimate reduce the estimated error significantly when compared to the conventional PTT estimation approach (p<0.05).

Effects of angiotensin, vasopressin and atrial natriuretic peptide on intraocular pressure in anesthetized rats

NASA Technical Reports Server (NTRS)

Palm, D. E.; Shue, S. G.; Keil, L. C.; Balaban, C. D.; Severs, W. B.

1995-01-01

The effects of atrial natriuretic peptide (ANP), vasopressin (AVP) and angiotensin (ANG) on blood and intraocular pressures of pentobarbital anesthetized rats were evaluated following intravenous, intracerebroventricular or anterior chamber routes of administration. Central injections did not affect intraocular pressure. Equipressor intravenous infusions of ANG raised, whereas AVP decreased, intraocular pressure. Direct infusions of a balanced salt solution (0.175 microliter/min) raised intraocular pressure between 30 and 60 min. Adding ANG or ANP slightly reduced this solvent effect but AVP was markedly inhibitory. An AVP-V1 receptor antagonist reversed the blunting of the solvent-induced rise by the peptide, indicating receptor specificity. Acetazolamide pretreatment lowered intraocular pressure, but the solvent-induced rise in intraocular pressure and inhibition by AVP still occurred without altering the temporal pattern. Thus, these effects appear unrelated to aqueous humor synthesis rate. The data support the possibility of intraocular pressure regulation by peptides acting from the blood and aqueous humor.

49 CFR 179.200-1 - Tank built under these specifications must meet the requirements of §§ 179.200, and 179.201.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS SPECIFICATIONS FOR TANK CARS Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.200-1 Tank built under these specifications must meet...

State School Finance Inequities and the Limits of Pursuing Teacher Equity through Departmental Regulation

ERIC Educational Resources Information Center

Baker, Bruce D.; Weber, Mark

2016-01-01

New federal regulations (State Plans to Ensure Equitable Access to Excellent Educators)1 place increased pressure on states and local public school districts to improve their measurement and reporting of gaps in teacher qualifications across schools and the children they serve. Yet a sole focus on resource disparities between schools within a…

Cops, Consultants, and Goldfish: Variations in Nursing Home Regulation.

ERIC Educational Resources Information Center

Gardiner, John A.

Nursing home regulatory agencies are subjected to a variety of pressures. Nursing home residents' families and friends want the agencies to "get tough" while the nursing home industry wants agencies to act as consultants rather than cops. The task of regulating nursing homes in the United States is primarily carried out by units of state…

Quantification of peripheral and central blood pressure variability using a time-frequency method.

PubMed

Kouchaki, Z; Butlin, M; Qasem, A; Avolio, A P

2016-08-01

Systolic blood pressure variability (BPV) is associated with cardiovascular events. As the beat-to-beat variation of blood pressure is due to interaction of several cardiovascular control systems operating with different response times, assessment of BPV by spectral analysis using the continuous measurement of arterial pressure in the finger is used to differentiate the contribution of these systems in regulating blood pressure. However, as baroreceptors are centrally located, this study considered applying a continuous aortic pressure signal estimated noninvasively from finger pressure for assessment of systolic BPV by a time-frequency method using Short Time Fourier Transform (STFT). The average ratio of low frequency and high frequency power band (LF PB /HF PB ) was computed by time-frequency decomposition of peripheral systolic pressure (pSBP) and derived central aortic systolic blood pressure (cSBP) in 30 healthy subjects (25-62 years) as a marker of balance between cardiovascular control systems contributing in low and high frequency blood pressure variability. The results showed that the BPV assessed from finger pressure (pBPV) overestimated the BPV values compared to that assessed from central aortic pressure (cBPV) for identical cardiac cycles (P<;0.001), with the overestimation being greater at higher power.

The Effect of Size and Species on Lens Intracellular Hydrostatic Pressure

PubMed Central

Gao, Junyuan; Sun, Xiurong; Moore, Leon C.; Brink, Peter R.; White, Thomas W.; Mathias, Richard T.

2013-01-01

Purpose. Previous experiments showed that mouse lenses have an intracellular hydrostatic pressure that varied from 335 mm Hg in central fibers to 0 mm Hg in surface cells. Model calculations predicted that in larger lenses, all else equal, pressure should increase as the lens radius squared. To test this prediction, lenses of different radii from different species were studied. Methods. All studies were done in intact lenses. Intracellular hydrostatic pressures were measured with a microelectrode-manometer–based system. Membrane conductances were measured by frequency domain impedance analysis. Intracellular Na+ concentrations were measured by injecting the Na+-sensitive dye sodium-binding benzofuran isophthalate. Results. Intracellular hydrostatic pressures were measured in lenses from mice, rats, rabbits, and dogs with radii (cm) 0.11, 0.22, 0.49, and 0.57, respectively. In each species, pressure varied from 335 ± 6 mm Hg in central fiber cells to 0 mm Hg in surface cells. Further characterization of transport in lenses from mice and rats showed that the density of fiber cell gap junction channels was approximately the same, intracellular Na+ concentrations varied from 17 mM in central fiber cells to 7 mM in surface cells, and intracellular voltages varied from −45 mV in central fiber cells to −60 mV in surface cells. Fiber cell membrane conductance was a factor of 2.7 times larger in mouse than in rat lenses. Conclusions. Intracellular hydrostatic pressure is an important physiological parameter that is regulated in lenses from these different species. The most likely mechanism of regulation is to reduce the density of open Na+-leak channels in fiber cells of larger lenses. PMID:23211824

Liquid rocket pressure regulators, relief valves, check valves, burst disks, and explosive valves. [design techniques and practices

NASA Technical Reports Server (NTRS)

1973-01-01

The development of and operational programs for effective use in design are presented for liquid rocket pressure regulators, relief valves, check valves, burst disks, and explosive valves. A review of the total design problem is presented, and design elements are identified which are involved in successful design. Current technology pertaining to these elements is also described. Design criteria are presented which state what rule or standard must be imposed on each essential design element to assure successful design. These criteria serve as a checklist of rules for a project manager to use in guiding a design or in assessing its adequacy. Recommended practices are included which state how to satisfy each of the criteria.

Self-regulating galaxy formation. Part 1: HII disk and Lyman alpha pressure

NASA Technical Reports Server (NTRS)

Cox, D. P.

1983-01-01

Assuming a simple but physically based prototype for behavior of interstellar material during formation of a disk galaxy, coupled with the lowest order description of infall, a scenario is developed for self-regulated disk galaxy formation. Radiation pressure, particularly that of Lyman depha (from fluorescence conversion Lyman continuum), is an essential component, maintaining an inflated disk and stopping infall when only a small fraction of the overall perturbation has joined the disk. The resulting galaxies consist of a two dimensional family whose typical scales and surface density are expressable in terms of fundamental constants. The model leads naturally to galaxies with a rich circumgalactic environment and flat rotation curves (but is weak in its analysis of the subsequent evolution of halo material).

Dynamic Characteristics of The DSI-Type Constant-Flow Valves

NASA Astrophysics Data System (ADS)

Kang, Yuan; Hu, Sheng-Yan; Chou, Hsien-Chin; Lee, Hsing-Han

Constant flow valves have been presented in industrial applications or academic studies, which compensate recess pressures of a hydrostatic bearing to resist load fluctuating. The flow rate of constant-flow valves can be constant in spite of the pressure changes in recesses, however the design parameters must be specified. This paper analyzes the dynamic responses of DSI-type constant-flow valves that is designed as double pistons on both ends of a spool with single feedback of working pressure and regulating restriction at inlet. In this study the static analysis presents the specific relationships among design parameters for constant flow rate and the dynamic analyses give the variations around the constant flow rate as the working pressure fluctuates.

Development of a cuffless blood pressure measurement system.

PubMed

Shyu, Liang-Yu; Kao, Yao-Lin; Tsai, Wen-Ya; Hu, Weichih

2012-01-01

This study constructs a novel blood pressure measurement device without the air cuff to overcome the problem of discomfort and portability. The proposed device measures the blood pressure through a mechanism that is made of silicon rubber and pressure transducer. The system uses a microcontroller to control the measurement procedure and to perform the necessary computation. To verify the feasibility of the constructed device, ten young volunteers were recruited. Ten blood pressure readings were obtained using the new system and were compared with ten blood pressure readings from bedside monitor (Spacelabs Medical, model 90367). The results indicated that, when all the readings were included, the mean pressure, systolic pressure and diastolic pressure from the new system were all higher than those from bedside monitor. The correlation coefficients between these two were 0.15, 0.18 and 0.29, for mean, systolic and diastolic pressures, respectively. After excluding irregular apparatus utilization, the correlation coefficient increased to 0.71, 0.60 and 0.41 for diastolic pressure, mean pressure and systolic pressure, respectively. We can conclude from these results that the accuracy can be improved effectively by defining the user regulation more precisely. The above mentioned irregular apparatus utilization factors can be identified and eliminated by the microprocessor to provide a reliable blood pressure measurement in practical applications in the future.

IQGAP1 regulates ERK1/2 and AKT signalling in the heart and sustains functional remodelling upon pressure overload

PubMed Central

Sbroggiò, Mauro; Carnevale, Daniela; Bertero, Alessandro; Cifelli, Giuseppe; De Blasio, Emanuele; Mascio, Giada; Hirsch, Emilio; Bahou, Wadie F.; Turco, Emilia; Silengo, Lorenzo; Brancaccio, Mara; Lembo, Giuseppe; Tarone, Guido

2011-01-01

Aims The Raf-MEK1/2-ERK1/2 (ERK1/2—extracellular signal-regulated kinases 1/2) signalling cascade is crucial in triggering cardiac responses to different stress stimuli. Scaffold proteins are key elements in coordinating signalling molecules for their appropriate spatiotemporal activation. Here, we investigated the role of IQ motif-containing GTPase-activating protein 1 (IQGAP1), a scaffold for the ERK1/2 cascade, in heart function and remodelling in response to pressure overload. Methods and results IQGAP1-null mice have unaltered basal heart function. When subjected to pressure overload, IQGAP1-null mice initially develop a compensatory hypertrophy indistinguishable from that of wild-type (WT) mice. However, upon a prolonged stimulus, the hypertrophic response develops towards a thinning of left ventricular walls, chamber dilation, and a decrease in contractility, in an accelerated fashion compared with WT mice. This unfavourable cardiac remodelling is characterized by blunted reactivation of the foetal gene programme, impaired cardiomyocyte hypertrophy, and increased cardiomyocyte apoptosis. Analysis of signalling pathways revealed two temporally distinct waves of both ERK1/2 and AKT phosphorylation peaking, respectively, at 10 min and 4 days after aortic banding in WT hearts. IQGAP1-null mice show strongly impaired phosphorylation of MEK1/2-ERK1/2 and AKT following 4 days of pressure overload, but normal activation of these kinases after 10 min. Pull-down experiments indicated that IQGAP1 is able to bind the three components of the ERK cascade, namely c-Raf, MEK1/2, and ERK1/2, as well as AKT in the heart. Conclusion These data demonstrate, for the first time, a key role for the scaffold protein IQGAP1 in integrating hypertrophy and survival signals in the heart and regulating long-term left ventricle remodelling upon pressure overload. PMID:21493702

Flowers under pressure: ins and outs of turgor regulation in development

PubMed Central

Beauzamy, Léna; Nakayama, Naomi; Boudaoud, Arezki

2014-01-01

Background Turgor pressure is an essential feature of plants; however, whereas its physiological importance is unequivocally recognized, its relevance to development is often reduced to a role in cell elongation. Scope This review surveys the roles of turgor in development, the molecular mechanisms of turgor regulation and the methods used to measure turgor and related quantities, while also covering the basic concepts associated with water potential and water flow in plants. Three key processes in flower development are then considered more specifically: flower opening, anther dehiscence and pollen tube growth. Conclusions Many molecular determinants of turgor and its regulation have been characterized, while a number of methods are now available to quantify water potential, turgor and hydraulic conductivity. Data on flower opening, anther dehiscence and lateral root emergence suggest that turgor needs to be finely tuned during development, both spatially and temporally. It is anticipated that a combination of biological experiments and physical measurements will reinforce the existing data and reveal unexpected roles of turgor in development. PMID:25288632

Stem Cells in the Trabecular Meshwork for Regulating Intraocular Pressure.

PubMed

Yun, Hongmin; Zhou, Yi; Wills, Andrew; Du, Yiqin

2016-06-01

Intraocular pressure (IOP) is still the main treatment target for glaucoma. Outflow resistance mainly exists at the trabecular meshwork (TM) outflow pathway, which is responsible for IOP regulation. Changes of TM cellularity and TM extracellular matrix turnover may play important roles in IOP regulation. In this article, we review basic anatomy and physiology of the outflow pathway and TM stem cell characteristics regarding the location, isolation, identification and function. TM stem cells are localized at the insert region of the TM and are label-retaining in vivo. They can be isolated by side-population cell sorting, cloning culture, or sphere culture. TM stem cells are multipotent with the ability to home to the TM region and differentiate into TM cells in vivo. Other stem cell types, such as adipose-derived stem cells, mesenchymal stem cells and induced pluripotent stem cells have been discovered for TM cell differentiation and TM regeneration. We also review glaucomatous animal models, which are suitable to study stem cell-based therapies for TM regeneration.

Stem Cells in the Trabecular Meshwork for Regulating Intraocular Pressure

PubMed Central

Yun, Hongmin; Zhou, Yi; Wills, Andrew

2016-01-01

Abstract Intraocular pressure (IOP) is still the main treatment target for glaucoma. Outflow resistance mainly exists at the trabecular meshwork (TM) outflow pathway, which is responsible for IOP regulation. Changes of TM cellularity and TM extracellular matrix turnover may play important roles in IOP regulation. In this article, we review basic anatomy and physiology of the outflow pathway and TM stem cell characteristics regarding the location, isolation, identification and function. TM stem cells are localized at the insert region of the TM and are label-retaining in vivo. They can be isolated by side-population cell sorting, cloning culture, or sphere culture. TM stem cells are multipotent with the ability to home to the TM region and differentiate into TM cells in vivo. Other stem cell types, such as adipose-derived stem cells, mesenchymal stem cells and induced pluripotent stem cells have been discovered for TM cell differentiation and TM regeneration. We also review glaucomatous animal models, which are suitable to study stem cell-based therapies for TM regeneration. PMID:27183473

Safety assessment for In-service Pressure Bending Pipe Containing Incomplete Penetration Defects

NASA Astrophysics Data System (ADS)

Wang, M.; Tang, P.; Xia, J. F.; Ling, Z. W.; Cai, G. Y.

2017-12-01

Incomplete penetration defect is a common defect in the welded joint of pressure pipes. While the safety classification of pressure pipe containing incomplete penetration defects, according to periodical inspection regulations in present, is more conservative. For reducing the repair of incomplete penetration defect, a scientific and applicable safety assessment method for pressure pipe is needed. In this paper, the stress analysis model of the pipe system was established for the in-service pressure bending pipe containing incomplete penetration defects. The local finite element model was set up to analyze the stress distribution of defect location and the stress linearization. And then, the applicability of two assessment methods, simplified assessment and U factor assessment method, to the assessment of incomplete penetration defects located at pressure bending pipe were analyzed. The results can provide some technical supports for the safety assessment of complex pipelines in the future.

Flammability and sensitivity of materials in oxygen-enriched atmospheres; Proceedings of the Fourth International Symposium, Las Cruces, NM, Apr. 11-13, 1989. Volume 4

NASA Technical Reports Server (NTRS)

Stoltzfus, Joel M. (Editor); Benz, Frank J. (Editor); Stradling, Jack S. (Editor)

1989-01-01

The present volume discusses the ignition of nonmetallic materials by the impact of high-pressure oxygen, the promoted combustion of nine structural metals in high-pressure gaseous oxygen, the oxygen sensitivity/compatibility ranking of several materials by different test methods, the ignition behavior of silicon greases in oxygen atmospheres, fire spread rates along cylindrical metal rods in high-pressure oxygen, and the design of an ignition-resistant, high pressure/temperature oxygen valve. Also discussed are the promoted ignition of oxygen regulators, the ignition of PTFE-lined flexible hoses by rapid pressurization with oxygen, evolving nonswelling elastomers for high-pressure oxygen environments, the evaluation of systems for oxygen service through the use of the quantitative fault-tree analysis, and oxygen-enriched fires during surgery of the head and neck.

Massage Therapy Research Review

PubMed Central

Field, Tiffany

2017-01-01

Moderate pressure massage has contributed to many positive effects including increased weight gain in preterm infants, reduced pain in different syndromes including fibromyalgia and rheumatoid arthritis, enhanced attentiveness, reduced depression and enhanced immune function (increased natural killer cells and natural killer cell activity). Surprisingly, these recent studies have not been reviewed, highlighting the need for the current review. When moderate and light pressure massage have been compared in laboratory studies, moderate pressure massage reduced depression, anxiety and heart rate, and it altered EEG patterns, as in a relaxation response. Moderate pressure massage has also led to increased vagal activity and decreased cortisol levels. Functional magnetic resonance imaging data have suggested that moderate pressure massage was represented in several brain regions including the amygdala, the hypothalamus and the anterior cingulate cortex, all areas involved in stress and emotion regulation. Further research is needed to identify underlying neurophysiological and biochemical mechanisms associated with moderate pressure massage. PMID:25172313

Enhanced Thermoelectric Properties of Double-Filled CoSb3 via High-Pressure Regulating.

PubMed

Wang, Libin; Deng, Le; Qin, Jieming; Jia, Xiaopeng

2018-05-24

It has been discussed for a long time that synthetic pressure can effectively optimize thermoelectric properties. The beneficial effect of synthesis pressures on thermoelectric properties has been discussed for a long time. In this paper, it is theoretically and experimentally demonstrated that appropriate synthesis pressures can increase the figure of merit (ZT) through optimizing thermal transport and electronic transport properties. Indium and barium atoms double-filled CoSb 3 samples were prepared use high-pressure and high-temperature technique for half an hour. X-ray diffraction and some structure analysis were used to reveal the relationship between microstructures and thermoelectric properties. In 0.15 Ba 0.35 Co 4 Sb 12 samples were synthesized by different pressures; sample synthesized by 3 GPa has the best electrical transport properties, and sample synthesized by 2.5 GPa has the lowest thermal conductivity. The maximum ZT value of sample synthesized by 3.0 GPa reached 1.18.

Massage therapy research review.

PubMed

Field, Tiffany

2014-11-01

Moderate pressure massage has contributed to many positive effects including increased weight gain in preterm infants, reduced pain in different syndromes including fibromyalgia and rheumatoid arthritis, enhanced attentiveness, reduced depression and enhanced immune function (increased natural killer cells and natural killer cell activity).Surprisingly, these recent studies have not been reviewed, highlighting the need for the current review. When moderate and light pressure massage have been compared in laboratory studies, moderate pressure massage reduced depression, anxiety and heart rate, and it altered EEG patterns, as in a relaxation response. Moderate pressure massage has also led to increased vagal activity and decreased cortisol levels. Functional magnetic resonance imaging data have suggested that moderate pressure massage was represented in several brain regions including the amygdala, the hypothalamus and the anterior cingulate cortex, all areas involved in stress and emotion regulation. Further research is needed to identify underlying neurophysiological and biochemical mechanisms associated with moderate pressure massage. Copyright © 2014 Elsevier Ltd. All rights reserved.

Hydrostatic fluid pressure in the vestibular organ of the guinea pig.

PubMed

Park, Jonas J-H; Boeven, Jahn J; Vogel, Stefan; Leonhardt, Steffen; Wit, Hero P; Westhofen, Martin

2012-07-01

Since inner ear hair cells are mechano-electric transducers the control of hydrostatic pressure in the inner ear is crucial. Most studies analyzing dynamics and regulation of inner ear hydrostatic pressure performed pressure measurements in the cochlea. The present study is the first one reporting about absolute hydrostatic pressure values in the labyrinth. Hydrostatic pressure of the endolymphatic system was recorded in all three semicircular canals. Mean pressure values were 4.06 cmH(2)O ± 0.61 in the posterior, 3.36 cmH(2)O ± 0.94 in the anterior and 3.85 cmH(2)O ± 1.38 in the lateral semicircular canal. Overall hydrostatic pressure in the vestibular organ was 3.76 cmH(2)O ± 0.36. Endolymphatic hydrostatic pressure in all three semicircular canals is the same (p = 0.310). With regard to known endolymphatic pressure values in the cochlea from past studies vestibular pressure values are comparable to cochlear values. Until now it is not known whether the reuniens duct and the Bast's valve which are the narrowest passages in the endolymphatic system are open or closed. Present data show that most likely the endolymphatic system is a functionally open entity.

Proceedings of the First Joint NASA Cardiopulmonary Workshop

NASA Technical Reports Server (NTRS)

Fortney, Suzanne M. (Editor); Hargens, Alan R. (Editor)

1991-01-01

The topics covered include the following: flight echocardiography, pulmonary function, central hemodynamics, glycerol hyperhydration, spectral analysis, lower body negative pressure countermeasures, orthostatic tolerance, autonomic function, cardiac deconditioning, fluid and renal responses to head-down tilt, local fluid regulation, endocrine regulation during bed rest, autogenic feedback, and chronic cardiovascular measurements. The program ended with a general discussion of weightlessness models and countermeasures.

Population dynamics in echinococcosis and cysticercosis: regulation of Taenia hydatigena and T. ovis in lambs through passively transferred immunity.

PubMed

Gemmell, M A; Lawson, J R; Roberts, M G; Griffin, J F

1990-08-01

A comparison has been made of the interactions between passively transferred and actively acquired immunity in regulating populations of Taenia hydatigena and T. ovis. When ewes were grazed prior to parturition under a high infection pressure, immunity was transferred to their offspring for up to 8 weeks. A qualitative difference between the species was the destruction of larval T. ovis prior to their establishment ('pre-encystment immunity') and that of T. hydatigena after they had become established ('post-encystment immunity') in the challenged lambs. The major difference in terms of population regulation between the two parasites was that infection occurred with T. hydatigena but not with T. ovis in those lambs reared from birth for 16 weeks under high infection pressure. Passive, like active immunity, is a density-dependent constraint. It plays an important role in the population regulation of T. ovis, but not of T. hydatigena. This is discussed in terms of transmission in the natural environment, an hypothesis on humoral protection and the need to elucidate pathways of protection when immunization schedules are being evaluated for controlling the taeniid zoonoses.

Novel ideas about salt, blood pressure, and pregnancy.

PubMed

Rakova, Natalia; Muller, Dominik N; Staff, Anne Cathrine; Luft, Friedrich C; Dechend, Ralf

2014-03-01

The molecular mechanisms leading to preeclampsia are poorly understood. It has been related to certain immune mechanisms, as well as the pathological regulation of the renin-angiotensin system together with perturbed salt and plasma volume regulation. Finally, a non-specific, vascular, inflammatory response is generated, which leads to the clinical syndrome. Here, we present novel findings in salt (NaCl) metabolism implying that salt is not only important in blood pressure control and volume homeostasis, but also in immune regulation. Sodium and chloride can be stored without accumulation of water in the interstitium at hypertonic concentrations through interactions with proteoglycans. Macrophages in the interstitium act as osmosensors for salt, producing increased amounts of vascular endothelial factor C, which increases the density of the lymph-capillary network and the production of nitric oxide in vessels. An increased interstitial salt concentration activates the innate immune system, especially Th17 cells, and may be an important trigger for autoimmune diseases. The novel findings with the idea of sodium storage and local mechanisms of volume and immune regulation are appealing for preeclampsia and may unify the "immune" and "vascular" hypotheses of preeclampsia. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Why do English players fail in soccer penalty shootouts? A study of team status, self-regulation, and choking under pressure.

PubMed

Jordet, Geir

2009-01-15

I examine why players from some nations appear always to choke in major international soccer penalty shootouts. Based on a model on choking under pressure as a type of self-defeating behaviour (Baumeister, 1997), I hypothesized that highly favourable public appraisals of a team would be linked to displays of escapist self-regulation strategies and inferior performance. I selected the eight most merited European nations, obtained videos from penalty shootouts in two major international tournaments (World Cup and European Championships), and analysed all 200 shots taken by players representing these teams. The results showed significant relationships between team status, self-regulation strategies, and performance. Players from countries that, at the time of the penalty shootout, either had many international club titles or featured many internationally decorated players, spent less time preparing their shots and were less successful from the penalty spot than players from countries with lower public status. England and Spain are used to illustrate these effects, as the data suggest that players from these two countries may have underperformed in previous international soccer tournaments because of high public status and misguided self-regulation strategies.