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Sample records for 2-tissue compartment model

  1. Two-Compartment Pharmacokinetic Models for Chemical Engineers

    ERIC Educational Resources Information Center

    Kanneganti, Kumud; Simon, Laurent

    2011-01-01

    The transport of potassium permanganate between two continuous-stirred vessels was investigated to help chemical and biomedical engineering students understand two-compartment pharmacokinetic models. Concepts of modeling, mass balance, parameter estimation and Laplace transform were applied to the two-unit process. A good agreement was achieved…

  2. Coastal Ecosystem Integrated Compartment Model (ICM): Modeling Framework

    NASA Astrophysics Data System (ADS)

    Meselhe, E. A.; White, E. D.; Reed, D.

    2015-12-01

    The Integrated Compartment Model (ICM) was developed as part of the 2017 Coastal Master Plan modeling effort. It is a comprehensive and numerical hydrodynamic model coupled to various geophysical process models. Simplifying assumptions related to some of the flow dynamics are applied to increase the computational efficiency of the model. The model can be used to provide insights about coastal ecosystems and evaluate restoration strategies. It builds on existing tools where possible and incorporates newly developed tools where necessary. It can perform decadal simulations (~ 50 years) across the entire Louisiana coast. It includes several improvements over the approach used to support the 2012 Master Plan, such as: additional processes in the hydrology, vegetation, wetland and barrier island morphology subroutines, increased spatial resolution, and integration of previously disparate models into a single modeling framework. The ICM includes habitat suitability indices (HSIs) to predict broad spatial patterns of habitat change, and it provides an additional integration to a dynamic fish and shellfish community model which quantitatively predicts potential changes in important fishery resources. It can be used to estimate the individual and cumulative effects of restoration and protection projects on the landscape, including a general estimate of water levels associated with flooding. The ICM is also used to examine possible impacts of climate change and future environmental scenarios (e.g. precipitation, Eustatic sea level rise, subsidence, tropical storms, etc.) on the landscape and on the effectiveness of restoration projects. The ICM code is publically accessible, and coastal restoration and protection groups interested in planning-level modeling are encouraged to explore its utility as a computationally efficient tool to examine ecosystem response to future physical or ecological changes, including the implementation of restoration and protection strategies.

  3. Identifiability Results for Several Classes of Linear Compartment Models.

    PubMed

    Meshkat, Nicolette; Sullivant, Seth; Eisenberg, Marisa

    2015-08-01

    Identifiability concerns finding which unknown parameters of a model can be estimated, uniquely or otherwise, from given input-output data. If some subset of the parameters of a model cannot be determined given input-output data, then we say the model is unidentifiable. In this work, we study linear compartment models, which are a class of biological models commonly used in pharmacokinetics, physiology, and ecology. In past work, we used commutative algebra and graph theory to identify a class of linear compartment models that we call identifiable cycle models, which are unidentifiable but have the simplest possible identifiable functions (so-called monomial cycles). Here we show how to modify identifiable cycle models by adding inputs, adding outputs, or removing leaks, in such a way that we obtain an identifiable model. We also prove a constructive result on how to combine identifiable models, each corresponding to strongly connected graphs, into a larger identifiable model. We apply these theoretical results to several real-world biological models from physiology, cell biology, and ecology.

  4. The pseudo-compartment method for coupling partial differential equation and compartment-based models of diffusion.

    PubMed

    Yates, Christian A; Flegg, Mark B

    2015-05-06

    Spatial reaction-diffusion models have been employed to describe many emergent phenomena in biological systems. The modelling technique most commonly adopted in the literature implements systems of partial differential equations (PDEs), which assumes there are sufficient densities of particles that a continuum approximation is valid. However, owing to recent advances in computational power, the simulation and therefore postulation, of computationally intensive individual-based models has become a popular way to investigate the effects of noise in reaction-diffusion systems in which regions of low copy numbers exist. The specific stochastic models with which we shall be concerned in this manuscript are referred to as 'compartment-based' or 'on-lattice'. These models are characterized by a discretization of the computational domain into a grid/lattice of 'compartments'. Within each compartment, particles are assumed to be well mixed and are permitted to react with other particles within their compartment or to transfer between neighbouring compartments. Stochastic models provide accuracy, but at the cost of significant computational resources. For models that have regions of both low and high concentrations, it is often desirable, for reasons of efficiency, to employ coupled multi-scale modelling paradigms. In this work, we develop two hybrid algorithms in which a PDE in one region of the domain is coupled to a compartment-based model in the other. Rather than attempting to balance average fluxes, our algorithms answer a more fundamental question: 'how are individual particles transported between the vastly different model descriptions?' First, we present an algorithm derived by carefully redefining the continuous PDE concentration as a probability distribution. While this first algorithm shows very strong convergence to analytical solutions of test problems, it can be cumbersome to simulate. Our second algorithm is a simplified and more efficient implementation of

  5. A theoretical compartment model for antigen kinetics in the skin.

    PubMed

    Römgens, Anne M; Bader, Dan L; Bouwstra, Joke A; Oomens, Cees W J

    2016-03-10

    The skin is a promising location for vaccination with its abundant population of antigen capturing and presenting cells. The development of new techniques, such as the use of microneedles, can facilitate the delivery of vaccines into the skin. In recent years, many different types of microneedle arrays have been designed. However, their geometry and arrangement within an array may be optimized to trigger sufficient antigen presenting cells. A computational model can support the rational design of microneedle arrays. Therefore, the aim of the current study was to describe the distribution and kinetics of a delivered antigen within the skin using a theoretical compartment model, which included binding of antigens to receptors and their uptake by cells, and to determine which parameters should be measured to validate the model for a specific application. Multiple simulations were performed using a high and low antigen delivery dose and a range of values for the rate constants. The results indicated that the cells were highly saturated when a high dose was applied, while for a low dose saturation was only reached in 5% of the simulations. This was caused by the difference in the ratio between the administered dose and the available binding sites and suggests the dose should be adapted to the number of cells and receptors for a specific compound. The sensitivity analysis of the model parameters confirmed that the initial dose and receptor concentrations were indeed the two parameters that had the largest influence on the variance in antigen concentrations within the cells and circulation at equilibrium. Hence, these parameters are important to be measured in vivo. The presented pharmacokinetics model can be used in future computational models to predict the influence of microneedle array geometry to optimize their design.

  6. Compartment modeling of dynamic brain PET—The impact of scatter corrections on parameter errors

    SciTech Connect

    Häggström, Ida Karlsson, Mikael; Larsson, Anne; Schmidtlein, C. Ross

    2014-11-01

    Purpose: The aim of this study was to investigate the effect of scatter and its correction on kinetic parameters in dynamic brain positron emission tomography (PET) tumor imaging. The 2-tissue compartment model was used, and two different reconstruction methods and two scatter correction (SC) schemes were investigated. Methods: The GATE Monte Carlo (MC) software was used to perform 2 × 15 full PET scan simulations of a voxelized head phantom with inserted tumor regions. The two sets of kinetic parameters of all tissues were chosen to represent the 2-tissue compartment model for the tracer 3′-deoxy-3′-({sup 18}F)fluorothymidine (FLT), and were denoted FLT{sub 1} and FLT{sub 2}. PET data were reconstructed with both 3D filtered back-projection with reprojection (3DRP) and 3D ordered-subset expectation maximization (OSEM). Images including true coincidences with attenuation correction (AC) and true+scattered coincidences with AC and with and without one of two applied SC schemes were reconstructed. Kinetic parameters were estimated by weighted nonlinear least squares fitting of image derived time–activity curves. Calculated parameters were compared to the true input to the MC simulations. Results: The relative parameter biases for scatter-eliminated data were 15%, 16%, 4%, 30%, 9%, and 7% (FLT{sub 1}) and 13%, 6%, 1%, 46%, 12%, and 8% (FLT{sub 2}) for K{sub 1}, k{sub 2}, k{sub 3}, k{sub 4}, V{sub a}, and K{sub i}, respectively. As expected, SC was essential for most parameters since omitting it increased biases by 10 percentage points on average. SC was not found necessary for the estimation of K{sub i} and k{sub 3}, however. There was no significant difference in parameter biases between the two investigated SC schemes or from parameter biases from scatter-eliminated PET data. Furthermore, neither 3DRP nor OSEM yielded the smallest parameter biases consistently although there was a slight favor for 3DRP which produced less biased k{sub 3} and K{sub i

  7. Numerical modelling of crural fascia mechanical interaction with muscular compartments.

    PubMed

    Pavan, Piero G; Pachera, Paola; Natali, Arturo N

    2015-05-01

    The interaction of the crural fascia with muscular compartments and surrounding tissues can be at the origin of different pathologies, such as compartment syndrome. This pathology consists in the onset of excessive intracompartmental pressure, which can have serious consequences for the patient, compromising blood circulation. The investigation of compartment syndrome etiology also takes into account the alteration of crural fascia mechanical properties as a cause of the syndrome, where the fascial stiffening would result in the rise of intracompartmental pressure. This work presents a computational approach toward evaluating some biomechanical aspects of the problem, within the context of a more global viewpoint. Finite element analyses of the interaction phenomena of the crural fascia with adjacent regions are reported here. This study includes the effects of a fascial stiffness increase along the proximal-distal direction and their possible clinical implications. Furthermore, the relationship between different pre-strain levels of the crural fascia in the proximal-distal direction and the rise of internal pressure in muscular compartments are considered. The numerical analyses can clarify which aspects could be directly implied in the rise of compartment syndrome, leading to greater insight into muscle-fascia mechanical phenomena, as well as promoting experimental investigation and clinical analysis of the syndrome.

  8. [Application of three compartment model and response surface model to clinical anesthesia using Microsoft Excel].

    PubMed

    Abe, Eiji; Abe, Mari

    2011-08-01

    With the spread of total intravenous anesthesia, clinical pharmacology has become more important. We report Microsoft Excel file applying three compartment model and response surface model to clinical anesthesia. On the Microsoft Excel sheet, propofol, remifentanil and fentanyl effect-site concentrations are predicted (three compartment model), and probabilities of no response to prodding, shaking, surrogates of painful stimuli and laryngoscopy are calculated using predicted effect-site drug concentration. Time-dependent changes in these calculated values are shown graphically. Recent development in anesthetic drug interaction studies are remarkable, and its application to clinical anesthesia with this Excel file is simple and helpful for clinical anesthesia.

  9. An approach to the residence time distribution for stochastic multi-compartment models.

    PubMed

    Yu, Jihnhee; Wehrly, Thomas E

    2004-10-01

    Stochastic compartmental models are widely used in modeling processes such as drug kinetics in biological systems. This paper considers the distribution of the residence times for stochastic multi-compartment models, especially systems with non-exponential lifetime distributions. The paper first derives the moment generating function of the bivariate residence time distribution for the two-compartment model with general lifetimes and approximates the density of the residence time using the saddlepoint approximation. Then, it extends the distributional approach to the residence time for multi-compartment semi-Markov models combining the cofactor rule for a single destination and the analytic approach to the two-compartment model. This approach provides a complete specification of the residence time distribution based on the moment generating function and thus facilitates an easier calculation of high-order moments than the approach using the coefficient matrix. Applications to drug kinetics demonstrate the simplicity and usefulness of this approach.

  10. Modeling fires in adjacent ship compartments with computational fluid dynamics

    SciTech Connect

    Wix, S.D.; Cole, J.K.; Koski, J.A.

    1998-05-10

    This paper presents an analysis of the thermal effects on radioactive (RAM) transportation packages with a fire in an adjacent compartment. An assumption for this analysis is that the adjacent hold fire is some sort of engine room fire. Computational fluid dynamics (CFD) analysis tools were used to perform the analysis in order to include convective heat transfer effects. The analysis results were compared to experimental data gathered in a series of tests on tile US Coast Guard ship Mayo Lykes located at Mobile, Alabama.

  11. Comparison of oral absorption models for pregabalin: usefulness of transit compartment model.

    PubMed

    Hong, Taegon; Han, Seunghoon; Lee, Jongtae; Jeon, Sangil; Yim, Dong-Seok

    2016-01-01

    Pregabalin is an anticonvulsant used for the treatment of neuropathic pain and partial seizure in adults. The aim of this study was to develop a population pharmacokinetic (PK) model to describe the absorption characteristics of pregabalin given fasted or after meals. Data from five healthy subject PK studies (n=88) of single- or multiple-dose pregabalin (150 mg) were used. Pregabalin was administered twice daily, without meals or 30 min after a meal (regular or high-fat diet) in the morning and 30 min or 4 h after a meal (regular diet) in the evening. Serial plasma samples were collected up to 24 h after the last dose for PK analysis. Because the peak concentrations were not properly modeled by a conventional first-order absorption model, Erlang frequency distribution, Weibull-type absorption, and transit compartment models were tested on a two-compartment linear PK model using a nonlinear mixed-effects method (NONMEM; version 7.3). The transit compartment model best described the absorption characteristics of pregabalin regardless of meal status. We conclude that the absorption model should be carefully chosen based on the principle of model development and validation and not by following a conventional first-order absorption model for its popularity and simplicity, especially when the PK dataset includes densely sampled absorption-phase data.

  12. Comparison of oral absorption models for pregabalin: usefulness of transit compartment model

    PubMed Central

    Hong, Taegon; Han, Seunghoon; Lee, Jongtae; Jeon, Sangil; Yim, Dong-Seok

    2016-01-01

    Pregabalin is an anticonvulsant used for the treatment of neuropathic pain and partial seizure in adults. The aim of this study was to develop a population pharmacokinetic (PK) model to describe the absorption characteristics of pregabalin given fasted or after meals. Data from five healthy subject PK studies (n=88) of single- or multiple-dose pregabalin (150 mg) were used. Pregabalin was administered twice daily, without meals or 30 min after a meal (regular or high-fat diet) in the morning and 30 min or 4 h after a meal (regular diet) in the evening. Serial plasma samples were collected up to 24 h after the last dose for PK analysis. Because the peak concentrations were not properly modeled by a conventional first-order absorption model, Erlang frequency distribution, Weibull-type absorption, and transit compartment models were tested on a two-compartment linear PK model using a nonlinear mixed-effects method (NONMEM; version 7.3). The transit compartment model best described the absorption characteristics of pregabalin regardless of meal status. We conclude that the absorption model should be carefully chosen based on the principle of model development and validation and not by following a conventional first-order absorption model for its popularity and simplicity, especially when the PK dataset includes densely sampled absorption-phase data. PMID:27994441

  13. The biomechanics of erections: two- versus one-compartment pressurized vessel modeling of the penis.

    PubMed

    Mohamed, Ahmed M; Erdman, Arthur G; Timm, Gerald W

    2010-12-01

    Previous biomechanical models of the penis simulated penile erections utilizing 2D geometry, simplified 3D geometry or made inaccurate assumptions altogether. These models designed the shaft of the penis as a one-compartment pressurized vessel fixed at one end when in reality it is a two-compartment pressurized vessel in which the compartments diverge as they enter the body and are fixed at two separate anatomic sites. This study utilizes the more anatomically correct two-compartment penile model to investigate erectile function. Simplified 2D and 3D models of the erect penis were developed using the finite element method with varying anatomical considerations for analyzing structural stresses, axial buckling, and lateral deformation. This study then validated the results by building and testing corresponding physical models. Finally, a more complex and anatomically accurate model of the penis was designed and analyzed. When subject to a lateral force of 0.5 N, the peak equivalent von Mises (EVM) stress in the two-compartment model increased by about 31.62%, while in the one-compartment model, the peak EVM stress increased by as high as 70.11%. The peak EVM stress was 149 kPa in the more complex and anatomically accurate penile model. When the perforated septum was removed, the peak EVM stress increased to 455 kPa. This study verified that there is significant difference between modeling the penis as a two- versus a one-compartment pressurized vessel. When subjected to external forces, a significant advantage was exhibited by two corporal based cavernosal bodies separated by a perforated septum as opposed to one corporal body. This is due to better structural integrity of the tunica albuginea when subjected to external forces.

  14. A ranking of diffusion MRI compartment models with in vivo human brain data

    PubMed Central

    Ferizi, Uran; Schneider, Torben; Panagiotaki, Eleftheria; Nedjati-Gilani, Gemma; Zhang, Hui; Wheeler-Kingshott, Claudia A M; Alexander, Daniel C

    2014-01-01

    Purpose Diffusion magnetic resonance imaging (MRI) microstructure imaging provides a unique noninvasive probe into tissue microstructure. The technique relies on biophysically motivated mathematical models, relating microscopic tissue features to the magnetic resonance (MR) signal. This work aims to determine which compartment models of diffusion MRI are best at describing measurements from in vivo human brain white matter. Methods Recent work shows that three compartment models, designed to capture intra-axonal, extracellular, and isotropically restricted diffusion, best explain multi-b-value data sets from fixed rat corpus callosum. We extend this investigation to in vivo by using a live human subject on a clinical scanner. The analysis compares models of one, two, and three compartments and ranks their ability to explain the measured data. We enhance the original methodology to further evaluate the stability of the ranking. Results As with fixed tissue, three compartment models explain the data best. However, a clearer hierarchical structure and simpler models emerge. We also find that splitting the scanning into shorter sessions has little effect on the ranking of models, and that the results are broadly reproducible across sessions. Conclusion Three compartments are required to explain diffusion MR measurements from in vivo corpus callosum, which informs the choice of model for microstructure imaging applications in the brain. Magn Reson Med 72:1785–1792, 2014. © 2013 The authors. Magnetic Resonance in Medicine Published by Wiley Periodicals, Inc. on behalf of International Society of Medicine in Resonance. PMID:24347370

  15. 78 FR 25846 - Special Conditions: Airbus, Model A340-600 Series Airplanes; Lower Deck Crew Rest Compartments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-03

    ...; Lower Deck Crew Rest Compartments AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final... unusual design feature associated with the installation of lower deck crew rest (LDCR) compartments. The... certificate to install a lower deck crew rest (LDCR) compartment in Airbus Model A340-600 series...

  16. 78 FR 21037 - Special Conditions: Airbus Model A330-200 Airplanes; Bulk Cargo Lower Deck Crew Rest Compartments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-09

    ... Cargo Lower Deck Crew Rest Compartments AGENCY: Federal Aviation Administration (FAA), DOT. ACTION... unusual design feature associated with the installation of bulk cargo lower deck crew rest compartments... supplemental type certificate to install a bulk cargo lower deck crew rest compartment in the Airbus Model...

  17. A four-compartment PBPK heart model accounting for cardiac metabolism - model development and application.

    PubMed

    Tylutki, Zofia; Polak, Sebastian

    2017-01-04

    In the field of cardiac drug efficacy and safety assessment, information on drug concentration in heart tissue is desirable. Because measuring drug concentrations in human cardiac tissue is challenging in healthy volunteers, mathematical models are used to cope with such limitations. With a goal of predicting drug concentration in cardiac tissue, we have developed a whole-body PBPK model consisting of seventeen perfusion-limited compartments. The proposed PBPK heart model consisted of four compartments: the epicardium, midmyocardium, endocardium, and pericardial fluid, and accounted for cardiac metabolism using CYP450. The model was written in R. The plasma:tissues partition coefficients (Kp) were calculated in Simcyp Simulator. The model was fitted to the concentrations of amitriptyline in plasma and the heart. The estimated parameters were as follows: 0.80 for the absorption rate [h(-1)], 52.6 for Kprest, 0.01 for the blood flow through the pericardial fluid [L/h], and 0.78 for the P-parameter describing the diffusion between the pericardial fluid and epicardium [L/h]. The total cardiac clearance of amitriptyline was calculated as 0.316 L/h. Although the model needs further improvement, the results support its feasibility, and it is a first attempt to provide an active drug concentration in various locations within heart tissue using a PBPK approach.

  18. A four-compartment PBPK heart model accounting for cardiac metabolism - model development and application

    PubMed Central

    Tylutki, Zofia; Polak, Sebastian

    2017-01-01

    In the field of cardiac drug efficacy and safety assessment, information on drug concentration in heart tissue is desirable. Because measuring drug concentrations in human cardiac tissue is challenging in healthy volunteers, mathematical models are used to cope with such limitations. With a goal of predicting drug concentration in cardiac tissue, we have developed a whole-body PBPK model consisting of seventeen perfusion-limited compartments. The proposed PBPK heart model consisted of four compartments: the epicardium, midmyocardium, endocardium, and pericardial fluid, and accounted for cardiac metabolism using CYP450. The model was written in R. The plasma:tissues partition coefficients (Kp) were calculated in Simcyp Simulator. The model was fitted to the concentrations of amitriptyline in plasma and the heart. The estimated parameters were as follows: 0.80 for the absorption rate [h−1], 52.6 for Kprest, 0.01 for the blood flow through the pericardial fluid [L/h], and 0.78 for the P-parameter describing the diffusion between the pericardial fluid and epicardium [L/h]. The total cardiac clearance of amitriptyline was calculated as 0.316 L/h. Although the model needs further improvement, the results support its feasibility, and it is a first attempt to provide an active drug concentration in various locations within heart tissue using a PBPK approach. PMID:28051093

  19. What Is the Most Realistic Single-Compartment Model of Spike Initiation?

    PubMed Central

    Brette, Romain

    2015-01-01

    A large variety of neuron models are used in theoretical and computational neuroscience, and among these, single-compartment models are a popular kind. These models do not explicitly include the dendrites or the axon, and range from the Hodgkin-Huxley (HH) model to various flavors of integrate-and-fire (IF) models. The main classes of models differ in the way spikes are initiated. Which one is the most realistic? Starting with some general epistemological considerations, I show that the notion of realism comes in two dimensions: empirical content (the sort of predictions that a model can produce) and empirical accuracy (whether these predictions are correct). I then examine the realism of the main classes of single-compartment models along these two dimensions, in light of recent experimental evidence. PMID:25856629

  20. Compartment models of the diffusion MR signal in brain white matter: a taxonomy and comparison.

    PubMed

    Panagiotaki, Eleftheria; Schneider, Torben; Siow, Bernard; Hall, Matt G; Lythgoe, Mark F; Alexander, Daniel C

    2012-02-01

    This paper aims to identify the minimum requirements for an accurate model of the diffusion MR signal in white matter of the brain. We construct a taxonomy of multi-compartment models of white matter from combinations of simple models for the intra- and the extra-axonal spaces. We devise a new diffusion MRI protocol that provides measurements with a wide range of imaging parameters for diffusion sensitization both parallel and perpendicular to white matter fibres. We use the protocol to acquire data from two fixed rat brains, which allows us to fit, study and compare the different models. The study examines a total of 47 analytic models, including several well-used models from the literature, which we place within the taxonomy. The results show that models that incorporate intra-axonal restriction, such as ball and stick or CHARMED, generally explain the data better than those that do not, such as the DT or the biexponential models. However, three-compartment models which account for restriction parallel to the axons and incorporate pore size explain the measurements most accurately. The best fit comes from combining a full diffusion tensor (DT) model of the extra-axonal space with a cylindrical intra-axonal component of single radius and a third spherical compartment of non-zero radius. We also measure the stability of the non-zero radius intra-axonal models and find that single radius intra-axonal models are more stable than gamma distributed radii models with similar fitting performance.

  1. Compartment model for long-term contamination prediction in deciduous fruit trees after a nuclear accident

    SciTech Connect

    Antonopoulos-Domis, M.; Clouvas, A.; Gagianas, A. )

    1990-06-01

    Radiocesium contamination from the Chernobyl accident of different parts (fruits, leaves, and shoots) of selected apricot trees in North Greece was systematically measured in 1987 and 1988. The results are presented and discussed in the framework of a simple compartment model describing the long-term contamination uptake mechanism of deciduous fruit trees after a nuclear accident.

  2. Characterizing exposure to chemicals from soil vapor intrusion using a two-compartment model

    NASA Astrophysics Data System (ADS)

    Olson, David A.; Corsi, Richard L.

    Though several different models have been developed for sub-surface migration, little attention has been given to the effect of subsurface transport on the indoor environment. Existing methods generally assume that a house is one well-mixed compartment. A two-compartment model was developed to better characterize this exposure pathway; the model treats the house as two well-mixed compartments, one for the basement and one for the remainder of the house. A field study was completed to quantify parameters associated with the two-compartment model, such as soil gas intrusion rates and basement to ground floor air exchange rates. Two residential test houses in Paulsboro, New Jersey were selected for this study. All experiments were completed using sulfur hexafluoride (SF 6) as a tracer gas. Soil gas intrusion rates were found to be highly dependent on the soil gas to basement pressure difference, varying from 0.001 m 3 m -2 h -1 for a pressure drop of -0.2 Pa to 0.011 m 3 m -2 h -1 for a pressure drop of -6.0 Pa. Basement ventilation rates ranged from 0.17 to 0.75 air changes per hour (ACH) for basement to ambient pressure differences ranging from -1.1 to -7.6 Pa (relative to ambient). Application of experimental results in conjunction with the two-compartment model indicate that exposures are highly dependent on gas intrusion rates, basement ventilation rate, and fraction of time spent in the basement. These results can also be significantly different when compared with the simple well-mixed house assumption.

  3. An earthquake instability model based on faults containing high fluid-pressure compartments

    USGS Publications Warehouse

    Lockner, D.A.; Byerlee, J.D.

    1995-01-01

    It has been proposed that large strike-slip faults such as the San Andreas contain water in seal-bounded compartments. Arguments based on heat flow and stress orientation suggest that in most of the compartments, the water pressure is so high that the average shear strength of the fault is less than 20 MPa. We propose a variation of this basic model in which most of the shear stress on the fault is supported by a small number of compartments where the pore pressure is relatively low. As a result, the fault gouge in these compartments is compacted and lithified and has a high undisturbed strength. When one of these locked regions fails, the system made up of the neighboring high and low pressure compartments can become unstable. Material in the high fluid pressure compartments is initially underconsolidated since the low effective confining pressure has retarded compaction. As these compartments are deformed, fluid pressure remains nearly unchanged so that they offer little resistance to shear. The low pore pressure compartments, however, are overconsolidated and dilate as they are sheared. Decompression of the pore fluid in these compartments lowers fluid pressure, increasing effective normal stress and shear strength. While this effect tends to stabilize the fault, it can be shown that this dilatancy hardening can be more than offset by displacement weakening of the fault (i.e., the drop from peak to residual strength). If the surrounding rock mass is sufficiently compliant to produce an instability, slip will propagate along the fault until the shear fracture runs into a low-stress region. Frictional heating and the accompanying increase in fluid pressure that are suggested to occur during shearing of the fault zone will act as additional destabilizers. However, significant heating occurs only after a finite amount of slip and therefore is more likely to contribute to the energetics of rupture propagation than to the initiation of the instability. We present

  4. Dynamic nuclear renography kinetic analysis: Four-compartment model for assessing kidney function

    SciTech Connect

    Raswan, T. R. Haryanto, F.

    2014-09-30

    Dynamic nuclear renography method produces TACs of kidneys and bladder. Multiple TACs data can be further analyzed to obtain the overview of urinary system's condition. Tracer kinetic analysis was performed using four-compartment models. The system's model consist of four irreversible compartment with four transport constants (k1, k2, k3 and k4). The mathematical expressions of tracer's distributions is fitted to experimental data (TACs) resulting in model constants. This transport constants represent the urinary system behavior, and later can be used for analyzing system's condition. Different intervals of kinetics parameter are clearly shown by abnormal system with respect to the normal one. Furthermore, the system with delayed uptake has 82% lower uptake parameters (k1 and k2) than normal one. Meanwhile, the system with prolonged clearance time has its kinetics parameters k3 or k4 lower than the others. This model is promising for quantitatively describe urinary system's function especially if supplied with more data.

  5. Dynamic nuclear renography kinetic analysis: Four-compartment model for assessing kidney function

    NASA Astrophysics Data System (ADS)

    Raswan, T. R.; Haryanto, F.

    2014-09-01

    Dynamic nuclear renography method produces TACs of kidneys and bladder. Multiple TACs data can be further analyzed to obtain the overview of urinary system's condition. Tracer kinetic analysis was performed using four-compartment models. The system's model consist of four irreversible compartment with four transport constants (k1, k2, k3 and k4). The mathematical expressions of tracer's distributions is fitted to experimental data (TACs) resulting in model constants. This transport constants represent the urinary system behavior, and later can be used for analyzing system's condition. Different intervals of kinetics parameter are clearly shown by abnormal system with respect to the normal one. Furthermore, the system with delayed uptake has 82% lower uptake parameters (k1 and k2) than normal one. Meanwhile, the system with prolonged clearance time has its kinetics parameters k3 or k4 lower than the others. This model is promising for quantitatively describe urinary system's function especially if supplied with more data.

  6. Description of glucose transport in isolated bovine mammary epithelial cells by a three-compartment model.

    PubMed

    Xiao, Changting; Quinton, V Margaret; Cant, John P

    2004-04-01

    Initial rates of glucose entry into isolated bovine mammary epithelial cells display moderate degrees of asymmetry and cooperative interactions between export and import sites. The present study examined the hypothesis that these kinetic features are due to compartmentalization of intracellular glucose. Net uptake of 3-O-methyl-d-[1-(3)H]glucose (3-OMG) by isolated bovine mammary epithelial cells was measured at 37 degrees C. The time course of 3-OMG net uptake was better fitted by a double-exponential equation than by a single- or triple-exponential equation. Compartmental analysis of the time course curve suggested that translocated 3-OMG is distributed into two compartments with fractional volumes of 32.6 +/- 5.7% and 67.4 +/- 5.7%, respectively. The results support the view that glucose transport in bovine mammary epithelial cells is a multistep process consisting of two serial steps: fast, carrier-mediated, symmetric translocation of sugar across the cell plasma membrane into a small compartment and subsequent slow exchange of posttranslocated sugar between two intracellular compartments. A three-compartment model of this system successfully simulated the observed time course of 3-OMG net uptake and the observed dependence of unidirectional entry rates on intra- and extracellular 3-OMG concentrations. Simulations indicated that backflux of radiolabeled sugar from the small compartment to extracellular space during 15 s of incubation gives rise to the apparent asymmetry, trans-stimulation, and cooperativity of mammary glucose transport kinetics. The fixed-site carrier model overestimated the rate of glucose accumulation in cells, and its features can be accounted for by the compartmentalization of intracellular sugar.

  7. A multi-compartment mass transfer model applied to building vapor intrusion

    NASA Astrophysics Data System (ADS)

    Murphy, Brian L.; Chan, Wanyu R.

    2011-12-01

    We develop a systematic approach to model steady-state advective and diffusive fluxes, as well as phase changes, between multi-media environmental compartments. The approach results in four simple rules for constructing mass transfer coefficients. Results are analogous to electrical circuit theory with resistors, including variable resistors or potentiometers, in parallel and series. This general approach lends itself particularly well to vapor intrusion calculations where there are multi-media compartments involving groundwater, soil, and air. In addition to showing that the model reduces to the well-known Johnson & Ettinger model in limiting cases, we illustrate its simplicity and ease of use with several examples: (1) an example of how multiple partition coefficients collapse into a single partition coefficient illustrated by a three-phase problem involving tar, water, and air, (2) determination of when the presence of a basement significantly lowers first floor exposures, and (3) addition of diffusion in the saturated zone to the model to investigate whether the resistance associated with this compartment can be neglected. We conclude that if the water table is truly steady, this resistance would be very significant. Therefore, a vapor intrusion model that neglects both water table fluctuations and diffusion in groundwater is ignoring important physical phenomena.

  8. SU-C-BRE-03: Dual Compartment Mathematical Modeling of Glioblastoma Multiforme (GBM)

    SciTech Connect

    Yu, V; Nguyen, D; Kupelian, P; Kaprealian, T; Selch, M; Low, D; Pajonk, F; Sheng, K

    2014-06-15

    Purpose: To explore the aggressive recurrence and radioresistence of GBM with a dual compartment tumor survival mathematical model based on intrinsic tumor heterogeneity, cancer stem cells (CSC) and differentiated cancer cells (DCC). Methods: The repopulation and differentiation responses to radiotherapy of a solid tumor were simulated using an Ordinary Differential Equation (ODE). To obtain the tumor radiobiological parameters, we assumed that a tumor consists of two subpopulations, each with its distinctive linear quadratic parameters. The dual compartment cell survival model was constructed as SF(D)=F × exp(-α{sub 1} D-β{sub 1}D{sup 2}) + (1-F) × exp(-α{sub 2}D-β{sub 2}D{sup 2}) for a single fraction of treatment, with F as the fraction of CSC, and α and β describing the radiological properties of each population. Robust least square fitting was performed on clonogenic survival data from one GBM (U373MG) and one NSCLC (H460) cell line. The fit parameters were then used in the ODE model to predict treatment outcome of various treatment schemes. Results: The fit parameters from GBM cell survival data were (F, α{sub 1}, β{sub 1}, α{sub 2}, β{sub 2})=(0.0396, 0.0801, 0.0006, 0.1363, 0.0279), exhibiting two populations with distinctive radiological properties, CSC more radioresistant than DCC. The GBM cell line exhibited significantly poorer tumor control than its single compartment model prediction and NSCLC, which responded well to hypofrationation. The increased radioresistance was due to rapid regrowth of the DCC compartment triggered by its depletion while maintaining a viable CSC population. The rapid regrowth can be reduced by treating dose fractions ≤ 2 Gy with a prolonged treatment period. Conclusion: The interaction between a radioresistant CSC compartment and DCC compartment can explain the poor clinical outcome of GBM after radiotherapy despite dose escalation and hypofractionation attempts. Lower dose fractions result in better treatment

  9. Stability and mixing conditions for HIV/AIDS models with regional compartments

    NASA Astrophysics Data System (ADS)

    Thomas, Richard

    Compartmental models have been adapted to derive temporal epidemic forecasting systems for imitating the transfer of HIV infection between those with different behaviours or rates of risk activity. Alternatively, models with regional compartments, which forecast disease incidence in both space and time, have emerged as a response to the challenge of anticipating the pandemic pathways of this infection. This paper combines these frameworks to obtain properties for a multiregion model that also contains demographic compartments. Section 2 begins by showing how the stability conditions (starting thresholds) for a purely regional model are a special case of the existing conditions that have been derived for the general compartmental framework. Then, these results are extended to encompass a regions with compartments design. Section 3 presents an analysis of the population mixing relationships that are embedded in all these specifications. Here, the topics include the maintenance of contact symmetry, the representation of alternative partner selection behaviours, and the identification of core populations for the diffusion of HIV infection. The discussion considers how these theoretical findings might be applied to disease prevention.

  10. Near-Infrared Monitoring of Model Chronic Compartment Syndrome In Exercising Skeletal Muscle

    NASA Technical Reports Server (NTRS)

    Hargens, Alan R.; Breit, G. A.; Gross, J. H.; Watenpaugh, D. E.; Chance, B.

    1995-01-01

    Chronic compartment syndrome (CCS) is characterized by muscle ischemia, usually in the anterior oompartment of the leg, caused by high intramuscular pressure during exercise. Dual-wave near-infrared (NIR) spectroscopy is an optical technique that allows noninvasive tracking of variations in muscle tissue oxygenation (Chance et al., 1988). We hypothesized that with a model CCS, muscle tissue oxygenation will show a greater decline during exercise and a slower recovery post-exercise than under normal conditions.

  11. Internal Blast in a Compartment-type Vessel. Part 1: Finite Element Modeling Investigation

    DTIC Science & Technology

    2012-11-01

    as the raytracer approach, were not part of this work but should be addressed in the future. The second investigation discusses different issues...suffisamment large pour inclure le compartiment au complet. Des méthodes alternatives, telle que l’approche ‘ raytracer ’, n’ont pas fait l’objet de ce...development and validation of a raytracer and its coupling with LS-DYNA will be addressed for modeling the shock loading in the first compartment. iv

  12. Organic Pollutant Penetration through Fruit Polyester Skin: A Modified Three-compartment Diffusion Model

    NASA Astrophysics Data System (ADS)

    Li, Yungui; Li, Qingqing; Chen, Baoliang

    2016-03-01

    The surface of plants is covered by a continuous but heterogeneous cuticular membrane (CM). Serving as the first protective barrier, the uptake and transport behavior of organic pollutants at this interface continue to engage the research efforts of environmental chemist. To date, the contributions of cuticular components as a defense against the organic pollutants penetration remain unresolved. In this study, the unsteady-state penetration characteristics of phenanthrene (PHE) through isolated fruit CM was investigated. PHE penetration was differentiated by three cuticular compartments: epicuticular waxes (EW), cuticle proper (CP) and cuticular layer (CL). The driving force for PHE penetration was ascribed to the sharp concentration gradient built up endogenously by cuticular compartments with different lipophilic affinities. A modified penetration model was established and verified in terms of its general suitability for the hydrophobic chemicals and CMs of various plant species (apple, tomato and potato). The new three-compartment model demonstrates much higher accuracy in characterizing the uptake and transport behavior of semivolatile chemicals with fewer limitations in terms of environmental conditions and complexity (e.g., coexisting contaminants and temperature). This model could contribute to a more comprehensive understanding on the role of polymeric lipids in the organic pollutant sorption and transport into plants.

  13. Organic Pollutant Penetration through Fruit Polyester Skin: A Modified Three-compartment Diffusion Model

    PubMed Central

    Li, Yungui; Li, Qingqing; Chen, Baoliang

    2016-01-01

    The surface of plants is covered by a continuous but heterogeneous cuticular membrane (CM). Serving as the first protective barrier, the uptake and transport behavior of organic pollutants at this interface continue to engage the research efforts of environmental chemist. To date, the contributions of cuticular components as a defense against the organic pollutants penetration remain unresolved. In this study, the unsteady-state penetration characteristics of phenanthrene (PHE) through isolated fruit CM was investigated. PHE penetration was differentiated by three cuticular compartments: epicuticular waxes (EW), cuticle proper (CP) and cuticular layer (CL). The driving force for PHE penetration was ascribed to the sharp concentration gradient built up endogenously by cuticular compartments with different lipophilic affinities. A modified penetration model was established and verified in terms of its general suitability for the hydrophobic chemicals and CMs of various plant species (apple, tomato and potato). The new three-compartment model demonstrates much higher accuracy in characterizing the uptake and transport behavior of semivolatile chemicals with fewer limitations in terms of environmental conditions and complexity (e.g., coexisting contaminants and temperature). This model could contribute to a more comprehensive understanding on the role of polymeric lipids in the organic pollutant sorption and transport into plants. PMID:27009902

  14. Compartment model of aerobic and anaerobic biodegradation in a municipal solid waste landfill.

    PubMed

    Kim, Sang-Yul; Tojo, Yasumasa; Matsuto, Toshihiko

    2007-12-01

    The mathematical formulations in a one-dimensional compartment model of the biodegradation of organic landfill components are described. The model is designed to switch between anaerobic and aerobic conditions, depending on the local oxygen concentration. The model also includes the effect of environmental factors, such as moisture content, pH, and temperature, on reaction rates. The model includes not only biodegradation processes for carbon compounds (acetate, CO2, CH4), but also for nitrogen compounds involved in nitrification and denitrification due to their significance in landfills. Two example runs to simulate anaerobic and aerobic waste were conducted for a single landfill unit cell by changing the organic content and diffusion coefficient.

  15. A Multi-Compartment Mathematical Model of Cancer Stem Cell Driven Tumor Growth Dynamics

    PubMed Central

    Weekes, Suzanne L.; Barker, Brian; Bober, Sarah; Cisneros, Karina; Cline, Justina; Thompson, Amanda; Hlatky, Lynn; Hahnfeldt, Philip; Enderling, Heiko

    2014-01-01

    Tumors are appreciated to be an intrinsically heterogeneous population of cells with varying proliferation capacities and tumorigenic potentials. As a central tenet of the so-called cancer stem cell hypothesis, most cancer cells have only a limited lifespan and thus cannot initiate or re-initiate tumors. Longevity and clonogenicity are properties unique to the subpopulation of cancer stem cells. To understand the implications of the population structure suggested by this hypothesis - a hierarchy consisting of cancer stem cells and progeny non-stem cancer cells which experience a reduction in their remaining proliferation capacity per division - we set out to develop a mathematical model for the development of the aggregate population. We show that overall tumor progression rate during the exponential growth phase is identical to the growth rate of the cancer stem cell compartment. Tumors with identical stem cell proportions, however, can have different growth rates, dependent on the proliferation kinetics of all participating cell populations. Analysis of the model revealed that the proliferation potential of non-stem cancer cells is likely to be small to reproduce biologic observations. Furthermore, a single compartment of non-stem cancer cell population may adequately represent population growth dynamics only when the compartment proliferation rate is scaled with the generational hierarchy depth. PMID:24840956

  16. Multi-Compartment T2 Relaxometry Using a Spatially Constrained Multi-Gaussian Model

    PubMed Central

    Raj, Ashish; Pandya, Sneha; Shen, Xiaobo; LoCastro, Eve; Nguyen, Thanh D.; Gauthier, Susan A.

    2014-01-01

    The brain’s myelin content can be mapped by T2-relaxometry, which resolves multiple differentially relaxing T2 pools from multi-echo MRI. Unfortunately, the conventional fitting procedure is a hard and numerically ill-posed problem. Consequently, the T2 distributions and myelin maps become very sensitive to noise and are frequently difficult to interpret diagnostically. Although regularization can improve stability, it is generally not adequate, particularly at relatively low signal to noise ratio (SNR) of around 100–200. The purpose of this study was to obtain a fitting algorithm which is able to overcome these difficulties and generate usable myelin maps from noisy acquisitions in a realistic scan time. To this end, we restrict the T2 distribution to only 3 distinct resolvable tissue compartments, modeled as Gaussians: myelin water, intra/extra-cellular water and a slow relaxing cerebrospinal fluid compartment. We also impose spatial smoothness expectation that volume fractions and T2 relaxation times of tissue compartments change smoothly within coherent brain regions. The method greatly improves robustness to noise, reduces spatial variations, improves definition of white matter fibers, and enhances detection of demyelinating lesions. Due to efficient design, the additional spatial aspect does not cause an increase in processing time. The proposed method was applied to fast spiral acquisitions on which conventional fitting gives uninterpretable results. While these fast acquisitions suffer from noise and inhomogeneity artifacts, our preliminary results indicate the potential of spatially constrained 3-pool T2 relaxometry. PMID:24896833

  17. A two-compartment population pharmacokinetic-pharmacodynamic model of digoxin in adults, with implications for dosage.

    PubMed

    Jelliffe, Roger W; Milman, Mark; Schumitzky, Alan; Bayard, David; Van Guilder, Michael

    2014-06-01

    A population pharmacokinetic/pharmacodynamic model of digoxin in adult subjects was originally developed by Reuning et al in 1973. They clearly described the 2-compartment behavior of digoxin, the lack of correlation of effect with serum concentrations, and the close correlation of the observed inotropic effect of digoxin with the calculated amount of drug present in the peripheral nonserum compartment. Their model seemed most attractive for clinical use. However, to make it more applicable for maximally precise dosage, its model parameter values (means and SD's) were converted into discrete model parameter distributions using a computer program developed especially for this purpose using the method of maximum entropy. In this way, the parameter distributions became discrete rather than continuous, suitable for use in developing maximally precise digoxin dosage regimens, individualized to an adult patient's age, gender, body weight, and renal function, to achieve desired specific target goals either in the central (serum) compartment or in the peripheral (effect) compartment using the method of multiple model dosage design. Some illustrative clinical applications of this model are presented and discussed. This model with a peripheral compartment reflecting clinical effect has contributed significantly to an improved understanding of the clinical behavior of digoxin in patients than is possible with models having only a single compartment, and to the improved management of digoxin therapy for more than 20 years.

  18. Two compartment model of diazepam biotransformation in an organotypical culture of primary human hepatocytes

    SciTech Connect

    Acikgoez, Ali; Karim, Najibulla; Giri, Shibashish; Schmidt-Heck, Wolfgang; Bader, Augustinus

    2009-01-15

    Drug biotransformation is one of the most important parameters of preclinical screening tests for the registration of new drug candidates. Conventional existing tests rely on nonhuman models which deliver an incomplete metabolic profile of drugs due to the lack of proper CYP450 expression as seen in human liver in vivo. In order to overcome this limitation, we used an organotypical model of human primary hepatocytes for the biotransformation of the drug diazepam with special reference to metabolites in both the cell matrix phase and supernatant and its interaction of three inducers (phenobarbital, dexamethasone, aroclor 1254) in different time responses (1, 2, 4, 8, 24 h). Phenobarbital showed the strongest inducing effect in generating desmethyldiazepam and induced up to a 150 fold increase in oxazepam-content which correlates with the increased availability of the precursor metabolites (temazepam and desmethyldiazepam). Aroclor 1254 and dexamethasone had the strongest inducing effect on temazepam and the second strongest on oxazepam. The strong and overlapping inductive role of phenobarbital strengthens the participation of CYP2B6 and CYP3A in diazepam N-demethylation and CYP3A in temazepam formation. Aroclor 1254 preferentially generated temazepam due to the interaction with CYP3A and potentially CYP2C19. In parallel we represented these data in the form of a mathematical model with two compartments explaining the dynamics of diazepam metabolism with the effect of these other inducers in human primary hepatocytes. The model consists of ten differential equations, with one for each concentration c{sub i,j} (i = diazepam, temazepam, desmethyldiazepam, oxazepam, other metabolites) and one for each compartment (j = cell matrix phase, supernatant), respectively. The parameters p{sub k} (k = 1, 2, 3, 4, 13) are rate constants describing the biotransformation of diazepam and its metabolites and the other parameters (k = 5, 6, 7, 8, 9, 10, 11, 12, 14, 15) explain the

  19. A multi-compartment 3-D finite element model of rectocele and its interaction with cystocele.

    PubMed

    Luo, Jiajia; Chen, Luyun; Fenner, Dee E; Ashton-Miller, James A; DeLancey, John O L

    2015-06-25

    We developed a subject-specific 3-D finite element model to understand the mechanics underlying formation of female pelvic organ prolapse, specifically a rectocele and its interaction with a cystocele. The model was created from MRI 3-D geometry of a healthy 45 year-old multiparous woman. It included anterior and posterior vaginal walls, levator ani muscle, cardinal and uterosacral ligaments, anterior and posterior arcus tendineus fascia pelvis, arcus tendineus levator ani, perineal body, perineal membrane and anal sphincter. Material properties were mostly from the literature. Tissue impairment was modeled as decreased tissue stiffness based on previous clinical studies. Model equations were solved using Abaqus v 6.11. The sensitivity of anterior and posterior vaginal wall geometry was calculated for different combinations tissue impairments under increasing intraabdominal pressure. Prolapse size was reported as pelvic organ prolapse quantification system (POP-Q) point at point Bp for rectocele and point Ba for cystocele. Results show that a rectocele resulted from impairments of the levator ani and posterior compartment support. For 20% levator and 85% posterior support impairments, simulated rectocele size (at POP-Q point: Bp) increased 0.29 mm/cm H2O without apical impairment and 0.36 mm/cm H2O with 60% apical impairment, as intraabdominal pressures increased from 0 to 150 cm H2O. Apical support impairment could result in the development of either a cystocele or rectocele. Simulated repair of posterior compartment support decreased rectocele but increased a preexisting cystocele. We conclude that development of rectocele and cystocele depend on the presence of anterior, posterior, levator and/or or apical support impairments, as well as the interaction of the prolapse with the opposing compartment.

  20. A Two-Compartment Model of VEGF Distribution in the Mouse

    PubMed Central

    Engel-Stefanini, Marianne O.; Popel, Aleksander S.

    2011-01-01

    Vascular endothelial growth factor (VEGF) is a key regulator of angiogenesis – the growth of new microvessels from existing microvasculature. Angiogenesis is a complex process involving numerous molecular species, and to better understand it, a systems biology approach is necessary. In vivo preclinical experiments in the area of angiogenesis are typically performed in mouse models; this includes drug development targeting VEGF. Thus, to quantitatively interpret such experimental results, a computational model of VEGF distribution in the mouse can be beneficial. In this paper, we present an in silico model of VEGF distribution in mice, determine model parameters from existing experimental data, conduct sensitivity analysis, and test the validity of the model. The multiscale model is comprised of two compartments: blood and tissue. The model accounts for interactions between two major VEGF isoforms (VEGF120 and VEGF164) and their endothelial cell receptors VEGFR-1, VEGFR-2, and co-receptor neuropilin-1. Neuropilin-1 is also expressed on the surface of parenchymal cells. The model includes transcapillary macromolecular permeability, lymphatic transport, and macromolecular plasma clearance. Simulations predict that the concentration of unbound VEGF in the tissue is approximately 50-fold greater than in the blood. These concentrations are highly dependent on the VEGF secretion rate. Parameter estimation was performed to fit the simulation results to available experimental data, and permitted the estimation of VEGF secretion rate in healthy tissue, which is difficult to measure experimentally. The model can provide quantitative interpretation of preclinical animal data and may be used in conjunction with experimental studies in the development of pro- and anti-angiogenic agents. The model approximates the normal tissue as skeletal muscle and includes endothelial cells to represent the vasculature. As the VEGF system becomes better characterized in other tissues and

  1. 75 FR 81 - Special Conditions: Boeing Model 787-8 Airplane; Overhead Flightcrew Rest Compartment Occupiable...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-04

    ... wishes to use an OFCR compartment as ``sleeping quarters,'' the compartment must undergo an additional... suitability'' evaluation or a ``sleeping quarters'' evaluation of its OFCR compartment. The results of these... berths and must be compatible with the sleeping position during cruise conditions. There must be...

  2. 75 FR 75 - Special Conditions: Boeing Model 787-8 Airplane; Overhead Crew Rest Compartment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-04

    ... operator wishes to use an OCR compartment as ``sleeping quarters,'' the compartment must undergo an... request a ``basic suitability'' evaluation or a ``sleeping quarters'' evaluation of its OCR compartment... provided for berths and must be compatible for the sleeping attitude during cruise conditions. There...

  3. Analytical model of ionization and energy deposition by proton beams in subcellular compartments

    NASA Astrophysics Data System (ADS)

    de Vera, Pablo; Surdutovich, Eugene; Abril, Isabel; Garcia-Molina, Rafael; Solov'yov, Andrey V.

    2014-04-01

    We present an analytical model to evaluate in a fast, simple and effective manner the energy delivered by proton beams moving through a cell model made of nucleus and cytoplasm, taking into account the energy carried by the secondary electrons generated along the proton tracks. The electronic excitation spectra of these subcellular compartments have been modelled by means of an empirical parameterization of their dielectric properties. The energy loss rate and target ionization probability induced by swift protons are evaluated by means of the dielectric formalism. With the present model we have quantified the energy delivered, the specific energy, and the number of ionizations produced per incoming ion in a typical human cell by a typical hadrontherapy proton beam having energies usually reached around the Bragg peak (below 20 MeV). We find that the specific energy per incoming ion delivered in the nucleus and in the cytoplasm are rather similar for all the proton energy range analyzed.

  4. Two-Compartment Kinetic Modeling of Radiocesium Accumulation in Marine Bivalves under Hypothetical Exposure Regimes.

    PubMed

    Pan, Ke; Tan, Qiao-Guo; Wang, Wen-Xiong

    2016-03-01

    Interpreting the variable concentrations of (137)Cs in the field biological samples requires mechanistic understanding of both environmental and biological behavior of (137)Cs. In this study, we used a two-compartment model to estimate and compare the (137)Cs biokinetics in three species of subtropical marine bivalves. Significant interspecific difference of (137)Cs biokinetics was observed among oysters, mussels, and scallops. There was considerable (137)Cs assimilation from phytoplankton in the bivalves, but the calculated trophic transfer factors were generally between 0.04 and 0.4. We demonstrated a major efflux of radiocesium in the scallops (with a rate constant of 0.207 d(-1)), whereas the efflux was comparable between oysters and mussels (0.035-0.038 d(-1)). A two-compartment kinetic model was developed to simulate the (137)Cs accumulation in the three bivalves under four hypothetical exposure regimes. We showed that the bivalves respond differently to the exposure regimes in terms of time to reach equilibrium, equilibrium concentration, and maximum concentration. Bivalves suffering more frequent intermittent exposure may have higher maximum concentrations than those receiving less frequent exposure. The interspecific difference of (137)Cs accumulation in bivalves has important implications for biomonitoring and implementing management techniques. This study represents one of the first attempts to combine both dissolved and dietary pathways to give a realistic simulation of (137)Cs accumulation in marine bivalves under dynamic exposure regimes.

  5. One-compartment model with Michaelis-Menten elimination kinetics and therapeutic window: an analytical approach.

    PubMed

    Tang, Sanyi; Xiao, Yanni

    2007-12-01

    The purpose of this article is to provide the analytical solutions of one-compartment models with Michaelis-Menten elimination kinetics for three different inputs (single intravenous dose, multiple-dose bolus injection and constant). All analytical solutions obtained in present paper can be described by the well defined Lambert W function which can be easily implemented in most mathematical softwares such as Matlab and Maple. These results will play an important role in fitting the Michaelis-Menten parameters and in designing a dosing regimen to maintain steady-state plasma concentrations. In particular, the analytical periodic solution for multi-dose inputs is also given, and we note that the maximum and minimum values of the periodic solution depends on the Michaelis-Menten parameters, dose and time interval of drug administration. In practice, it is important to maintain a concentration above the minimum therapeutic level at all times without exceeding the minimum toxic concentration. Therefore, the one-compartment model with therapeutic window is proposed, and further the existence of periodic solution, analytical expression and its period are analyzed. The analytical formula of period plays a key role in designing a dose regimen to maintain the plasma concentration within a specified range over long periods of therapy. Finally, the completely analytical solution for the constant input rate is derived and discussed which depends on the relations between constant input rate and maximum rate of change of concentration.

  6. Two-Stage Single-Compartment Models to Evaluate Dissolution in the Lower Intestine.

    PubMed

    Markopoulos, Constantinos; Vertzoni, Maria; Symillides, Mira; Kesisoglou, Filippos; Reppas, Christos

    2015-09-01

    The purpose was to propose two-stage single-compartment models for evaluating dissolution characteristics in distal ileum and ascending colon, under conditions simulating the bioavailability and bioequivalence studies in fasted and fed state by using the mini-paddle and the compendial flow-through apparatus (closed-loop mode). Immediate release products of two highly dosed active pharmaceutical ingredients (APIs), sulfasalazine and L-870,810, and one mesalamine colon targeting product were used for evaluating their usefulness. Change of medium composition simulating the conditions in distal ileum (SIFileum ) to a medium simulating the conditions in ascending colon in fasted state and in fed state was achieved by adding an appropriate solution in SIFileum . Data with immediate release products suggest that dissolution in lower intestine is substantially different than in upper intestine and is affected by regional pH differences > type/intensity of fluid convection > differences in concentration of other luminal components. Asacol® (400 mg/tab) was more sensitive to type/intensity of fluid convection. In all the cases, data were in line with available human data. Two-stage single-compartment models may be useful for the evaluation of dissolution in lower intestine. The impact of type/intensity of fluid convection and viscosity of media on luminal performance of other APIs and drug products requires further exploration.

  7. (Tri)butyltin biotic degradation rates and pathways in different compartments of a freshwater model ecosystem.

    PubMed

    Tessier, Emmanuel; Amouroux, David; Morin, Anne; Christian, Lehnhoff; Thybaud, Eric; Vindimian, Eric; Donard, Olivier F X

    2007-12-15

    Experiments were conducted in controlled temperate freshwater ecosystems (microcosms) to determine the persistence and biogeochemical dynamic of tributyltin (TBT) and its degradation products. TBT and its derivatives were monitored simultaneously for 23 days (552 h) in sediment-water systems, with or without macroorganisms (macrophytes: Elodea canadensis and gastropods: Lymnaea stagnalis). Biphasic TBT removal from the water column was significantly enhanced by the presence of biota. The persistence of TBT in biota was assessed by a kinetic approach of the different bioaccumulation pathways and associated metabolisms adopted by the snails and the macrophytes in response to the TBT contamination. Furthermore, sediment acted for the final sink for butyltins in both types of microcosms, with more than 70% of TBT and its metabolites recovered in this compartment after two weeks of exposure. Degradation pathways in sediments of both biotic and abiotic microcosms appeared to represent a key process in TBT cycle and were characterized by half-lives in the range of one month. Specific transformation and transfer pathways of TBT as reactional mechanisms are discussed and modelled assessing in detail the role of each compartment with regards to the fate of TBT in the model aquatic ecosystems.

  8. Tuneable resolution as a systems biology approach for multi-scale, multi-compartment computational models.

    PubMed

    Kirschner, Denise E; Hunt, C Anthony; Marino, Simeone; Fallahi-Sichani, Mohammad; Linderman, Jennifer J

    2014-01-01

    The use of multi-scale mathematical and computational models to study complex biological processes is becoming increasingly productive. Multi-scale models span a range of spatial and/or temporal scales and can encompass multi-compartment (e.g., multi-organ) models. Modeling advances are enabling virtual experiments to explore and answer questions that are problematic to address in the wet-lab. Wet-lab experimental technologies now allow scientists to observe, measure, record, and analyze experiments focusing on different system aspects at a variety of biological scales. We need the technical ability to mirror that same flexibility in virtual experiments using multi-scale models. Here we present a new approach, tuneable resolution, which can begin providing that flexibility. Tuneable resolution involves fine- or coarse-graining existing multi-scale models at the user's discretion, allowing adjustment of the level of resolution specific to a question, an experiment, or a scale of interest. Tuneable resolution expands options for revising and validating mechanistic multi-scale models, can extend the longevity of multi-scale models, and may increase computational efficiency. The tuneable resolution approach can be applied to many model types, including differential equation, agent-based, and hybrid models. We demonstrate our tuneable resolution ideas with examples relevant to infectious disease modeling, illustrating key principles at work.

  9. Global stability of a multiple infected compartments model for waterborne diseases

    NASA Astrophysics Data System (ADS)

    Wang, Yi; Cao, Jinde

    2014-10-01

    In this paper, mathematical analysis is carried out for a multiple infected compartments model for waterborne diseases, such as cholera, giardia, and rotavirus. The model accounts for both person-to-person and water-to-person transmission routes. Global stability of the equilibria is studied. In terms of the basic reproduction number R0, we prove that, if R0⩽1, then the disease-free equilibrium is globally asymptotically stable and the infection always disappears; whereas if R0>1, there exists a unique endemic equilibrium which is globally asymptotically stable for the corresponding fast-slow system. Numerical simulations verify our theoretical results and present that the decay rate of waterborne pathogens has a significant impact on the epidemic growth rate. Also, we observe numerically that the unique endemic equilibrium is globally asymptotically stable for the whole system. This statement indicates that the present method need to be improved by other techniques.

  10. Coupled solutions of one- and two-compartment pharmacokinetic models with first-order absorption.

    PubMed

    Asmanova, N; Koloskov, G; Ilin, A I

    2013-04-01

    This work emphasizes the importance of the fact, that plasma concentration profiles of one- and two-compartment linear pharmacokinetic (PK) models with first-order absorption introduce an uncertainty in data interpretation. PK-curve fitting results in a pair of valid solutions (coupled solutions), for which the derived PK parameters (such as AUC, MRT, Cmax, tmax, initial and terminal slope) are identical. Therefore, to make a proper choice of PK parameters of the drug in question, more information has to be considered, for example, which one of the solutions is more correlated with corresponding data, observed after iv administration. Comparison of different types of PK models and discussion on the transitions between the coupled solutions was carried out using a novel symbolic notation to provide more clarity and to simplify parameter indexing. Presented results were obtained by combined means of the method of statistic moments, Laplace transform and illustrated by the numerical experiment.

  11. Cross-species genomics matches driver mutations and cell compartments to model ependymoma.

    PubMed

    Johnson, Robert A; Wright, Karen D; Poppleton, Helen; Mohankumar, Kumarasamypet M; Finkelstein, David; Pounds, Stanley B; Rand, Vikki; Leary, Sarah E S; White, Elsie; Eden, Christopher; Hogg, Twala; Northcott, Paul; Mack, Stephen; Neale, Geoffrey; Wang, Yong-Dong; Coyle, Beth; Atkinson, Jennifer; DeWire, Mariko; Kranenburg, Tanya A; Gillespie, Yancey; Allen, Jeffrey C; Merchant, Thomas; Boop, Fredrick A; Sanford, Robert A; Gajjar, Amar; Ellison, David W; Taylor, Michael D; Grundy, Richard G; Gilbertson, Richard J

    2010-07-29

    Understanding the biology that underlies histologically similar but molecularly distinct subgroups of cancer has proven difficult because their defining genetic alterations are often numerous, and the cellular origins of most cancers remain unknown. We sought to decipher this heterogeneity by integrating matched genetic alterations and candidate cells of origin to generate accurate disease models. First, we identified subgroups of human ependymoma, a form of neural tumour that arises throughout the central nervous system (CNS). Subgroup-specific alterations included amplifications and homozygous deletions of genes not yet implicated in ependymoma. To select cellular compartments most likely to give rise to subgroups of ependymoma, we matched the transcriptomes of human tumours to those of mouse neural stem cells (NSCs), isolated from different regions of the CNS at different developmental stages, with an intact or deleted Ink4a/Arf locus (that encodes Cdkn2a and b). The transcriptome of human supratentorial ependymomas with amplified EPHB2 and deleted INK4A/ARF matched only that of embryonic cerebral Ink4a/Arf(-/-) NSCs. Notably, activation of Ephb2 signalling in these, but not other, NSCs generated the first mouse model of ependymoma, which is highly penetrant and accurately models the histology and transcriptome of one subgroup of human supratentorial tumour. Further, comparative analysis of matched mouse and human tumours revealed selective deregulation in the expression and copy number of genes that control synaptogenesis, pinpointing disruption of this pathway as a critical event in the production of this ependymoma subgroup. Our data demonstrate the power of cross-species genomics to meticulously match subgroup-specific driver mutations with cellular compartments to model and interrogate cancer subgroups.

  12. Compartment syndrome

    MedlinePlus

    ... compartment will lead to increased pressure in that area. This raised pressure, presses the muscles, blood vessels, ... Decreased sensation, numbness, tingling, weakness of the affected area Paleness of skin Severe pain that doesn't ...

  13. Compartment syndromes

    NASA Technical Reports Server (NTRS)

    Mubarak, S. J.; Pedowitz, R. A.; Hargens, A. R.

    1989-01-01

    The compartment syndrome is defined as a condition in which high pressure within a closed fascial space (muscle compartment) reduces capillary blood perfusion below the level necessary for tissue viability'. This condition occurs in acute and chronic (exertional) forms, and may be secondary to a variety of causes. The end-result of an extended period of elevated intramuscular pressure may be the development of irreversible tissue injury and Volkmann's contracture. The goal of treatment of the compartment syndrome is the reduction of intracompartmental pressure thus facilitating reperfusion of ischaemic tissue and this goal may be achieved by decompressive fasciotomy. Controversy exists regarding the critical pressure-time thresholds for surgical decompression and the optimal diagnostic methods of measuring intracompartmental pressures. This paper will update and review some current knowledge regarding the pathophysiology, aetiology, diagnosis, and treatment of the acute compartment syndrome.

  14. A multiobjective modeling approach to locate multi-compartment containers for urban-sorted waste

    SciTech Connect

    Tralhao, Lino; Coutinho-Rodrigues, Joao; Alcada-Almeida, Luis

    2010-12-15

    The location of multi-compartment sorted waste containers for recycling purposes in cities is an important problem in the context of urban waste management. The costs associated with those facilities and the impacts placed on populations are important concerns. This paper introduces a mixed-integer, multiobjective programming approach to identify the locations and capacities of such facilities. The approach incorporates an optimization model in a Geographical Information System (GIS)-based interactive decision support system that includes four objectives. The first objective minimizes the total investment cost; the second one minimizes the average distance from dwellings to the respective multi-compartment container; the last two objectives address the 'pull' and 'push' characteristics of the decision problem, one by minimizing the number of individuals too close to any container, and the other by minimizing the number of dwellings too far from the respective multi-compartment container. The model determines the number of facilities to be opened, the respective container capacities, their locations, their respective shares of the total waste of each type to be collected, and the dwellings assigned to each facility. The approach proposed was tested with a case study for the historical center of Coimbra city, Portugal, where a large urban renovation project, addressing about 800 buildings, is being undertaken. This paper demonstrates that the models and techniques incorporated in the interactive decision support system (IDSS) can be used to assist a decision maker (DM) in analyzing this complex problem in a realistically sized urban application. Ten solutions consisting of different combinations of underground containers for the disposal of four types of sorted waste in 12 candidate sites, were generated. These solutions and tradeoffs among the objectives are presented to the DM via tables, graphs, color-coded maps and other graphics. The DM can then use this

  15. Network bursting using experimentally constrained single compartment CA3 hippocampal neuron models with adaptation.

    PubMed

    Dur-e-Ahmad, Muhammad; Nicola, Wilten; Campbell, Sue Ann; Skinner, Frances K

    2012-08-01

    The hippocampus is a brain structure critical for memory functioning. Its network dynamics include several patterns such as sharp waves that are generated in the CA3 region. To understand how population outputs are generated, models need to consider aspects of network size, cellular and synaptic characteristics and context, which are necessarily 'balanced' in appropriate ways to produce particular outputs. Thick slice hippocampal preparations spontaneously produce sharp waves that are initiated in CA3 regions and depend on the right balance of glutamatergic activities. As a step toward developing network models that can explain important balances in the generation of hippocampal output, we develop models of CA3 pyramidal cells. Our models are single compartment in nature, use an Izhikevich-type structure and involve parameter values that are specifically designed to encompass CA3 intrinsic properties. Importantly, they incorporate spike frequency adaptation characteristics that are directly comparable to those measured experimentally. Excitatory networks using these model cells are able to produce bursting suggesting that the amount of spike frequency adaptation expressed in the biological cells is an essential contributor to network bursting, and as such, may be important for sharp wave generation. The network bursting mechanism is numerically dissected showing the critical balance between adaptation and excitatory drive. The compact nature of our models allows large network simulations to be efficiently computed. This, together with the linkage of our models to cellular characteristics, will allow us to develop an understanding of population output of CA3 hippocampus with direct biological comparisons.

  16. 76 FR 10476 - Special Conditions: Boeing Model 787-8 Airplane; Overhead Crew-Rest Compartment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-25

    ... Crew- Rest Compartment AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final special... will have novel or unusual design features associated with installation of an overhead crew-rest (OCR... Sec. 21.101. Novel or Unusual Design Features Crew-rest compartments have been installed...

  17. Compartment-based hydrodynamics and water quality modeling of a northern Everglades wetland, Florida, USA

    USGS Publications Warehouse

    Wang, Hongqing; Meselhe, Ehab A.; Waldon, Michael G.; Harwell, Matthew C.; Chen, Chunfang

    2012-01-01

    The last remaining large remnant of softwater wetlands in the US Florida Everglades lies within the Arthur R. Marshall Loxahatchee National Wildlife Refuge. However, Refuge water quality today is impacted by pumped stormwater inflows to the eutrophic and mineral-enriched 100-km canal, which circumscribes the wetland. Optimal management is a challenge and requires scientifically based predictive tools to assess and forecast the impacts of water management on Refuge water quality. In this research, we developed a compartment-based numerical model of hydrodynamics and water quality for the Refuge. Using the numerical model, we examined the dynamics in stage, water depth, discharge from hydraulic structures along the canal, and exchange flow among canal and marsh compartments. We also investigated the transport of chloride, sulfate and total phosphorus from the canal to the marsh interior driven by hydraulic gradients as well as biological removal of sulfate and total phosphorus. The model was calibrated and validated using long-term stage and water quality data (1995-2007). Statistical analysis indicates that the model is capable of capturing the spatial (from canal to interior marsh) gradients of constituents across the Refuge. Simulations demonstrate that flow from the eutrophic and mineral-enriched canal impacts chloride and sulfate in the interior marsh. In contrast, total phosphorus in the interior marsh shows low sensitivity to intrusion and dispersive transport. We conducted a rainfall-driven scenario test in which the pumped inflow concentrations of chloride, sulfate and total phosphorus were equal to rainfall concentrations (wet deposition). This test shows that pumped inflow is the dominant factor responsible for the substantially increased chloride and sulfate concentrations in the interior marsh. Therefore, the present day Refuge should not be classified as solely a rainfall-driven or ombrotrophic wetland. The model provides an effective screening tool for

  18. Tuneable resolution as a systems biology approach for multi-scale, multi-compartment computational models

    PubMed Central

    Kirschner, Denise E; Hunt, C Anthony; Marino, Simeone; Fallahi-Sichani, Mohammad; Linderman, Jennifer J

    2014-01-01

    The use of multi-scale mathematical and computational models to study complex biological processes is becoming increasingly productive. Multi-scale models span a range of spatial and/or temporal scales and can encompass multi-compartment (e.g., multi-organ) models. Modeling advances are enabling virtual experiments to explore and answer questions that are problematic to address in the wet-lab. Wet-lab experimental technologies now allow scientists to observe, measure, record, and analyze experiments focusing on different system aspects at a variety of biological scales. We need the technical ability to mirror that same flexibility in virtual experiments using multi-scale models. Here we present a new approach, tuneable resolution, which can begin providing that flexibility. Tuneable resolution involves fine- or coarse-graining existing multi-scale models at the user's discretion, allowing adjustment of the level of resolution specific to a question, an experiment, or a scale of interest. Tuneable resolution expands options for revising and validating mechanistic multi-scale models, can extend the longevity of multi-scale models, and may increase computational efficiency. The tuneable resolution approach can be applied to many model types, including differential equation, agent-based, and hybrid models. We demonstrate our tuneable resolution ideas with examples relevant to infectious disease modeling, illustrating key principles at work. WIREs Syst Biol Med 2014, 6:225–245. doi:10.1002/wsbm.1270 How to cite this article: WIREs Syst Biol Med 2014, 6:289–309. doi:10.1002/wsbm.1270 PMID:24810243

  19. Three-compartment model for contaminant accumulation by semipermeable membrane devices

    USGS Publications Warehouse

    Gale, Robert W.

    1998-01-01

    Passive sampling of dissolved hydrophobic contaminants with lipid (triolein)-containing semipermeable membrane devices (SPMDs) has been gaining acceptance for environmental monitoring. Understanding of the accumulation process has employed a simple polymer film-control model of uptake by the polymer-enclosed lipid, while aqueous film control has been only briefly discussed. A more complete three-compartment model incorporating both aqueous film (turbulent-diffusive) and polymer film (diffusive) mass transfer is developed here and is fit to data from accumulation studies conducted in constant-concentration, flow-through dilutors. This model predicts aqueous film control of the whole device for moderate to high Kow compounds, rather than polymer film control. Uptake rates for phenanthrene and 2,2‘,5,5‘-tetrachlorobiphenyl were about 4.8 and 4.2 L/day/standard SPMD, respectively. Maximum 28 day SPMD concentration factors of 30 000 are predicted for solutes with log Kow values of >5.5. Effects of varying aqueous and polymer film thicknesses and solute diffusivities in the polymer film are modeled, and overall accumulation by the whole device is predicted to remain under aqueous film control, although accumulation in the triolein may be subject to polymer film control. The predicted half-life and integrative response of SPMDs to pulsed concentration events is proportional to log KSPMD.

  20. A two or three compartments hyperbolic reaction-diffusion model for the aquatic food chain.

    PubMed

    Barbera, Elvira; Consolo, Giancarlo; Valenti, Giovanna

    2015-06-01

    Two hyperbolic reaction-diffusion models are built up in the framework of Extended Thermodynamics in order to describe the spatio-temporal interactions occurring in a two or three compartments aquatic food chain. The first model focuses on the dynamics between phytoplankton and zooplankton, whereas the second one accounts also for the nutrient. In these models, infections and influence of illumination on photosynthesis are neglected. It is assumed that the zooplankton predation follows a Holling type-III functional response, while the zooplankton mortality is linear. Owing to the hyperbolic structure of our equations, the wave processes occur at finite velocity, so that the paradox of instantaneous diffusion of biological quantities, typical of parabolic systems, is consequently removed. The character of steady states and travelling waves, together with the occurrence of Hopf bifurcations, is then discussed through linear stability analysis. The governing equations are also integrated numerically to validate the analytical results herein obtained and to extract additional information on the population dynamics.

  1. Two-compartment model as a teaching tool for cholesterol homeostasis.

    PubMed

    Wrona, Artur; Balbus, Joanna; Hrydziuszko, Olga; Kubica, Krystian

    2015-12-01

    Cholesterol is a vital structural and functional molecule in the human body that is only slightly soluble in water and therefore does not easily travels by itself in the bloodstream. To enable cholesterol's targeted delivery to cells and tissues, it is encapsulated by different fractions of lipoproteins, complex particles containing both proteins and lipids. Maintaining cholesterol homeostasis is a highly regulated process with multiple factors acting at both molecular and tissue levels. Furthermore, to regulate the circulatory transport of cholesterol in lipoproteins, the amount of cholesterol present depends on and is controlled by cholesterol dietary intake, de novo synthesis, usage, and excretion; abnormal and/or unbalanced cholesterol levels have been shown to lead to severe outcomes, e.g., cardiovascular diseases. To investigate cholesterol transport in the circulatory system, we have previously developed a two-compartment mathematical model. Here, we show how this model can be used as a teaching tool for cholesterol homeostasis. Using the model and a hands-on approach, students can familiarize themselves with the basic components and mechanisms behind balanced cholesterol circulatory transport as well as investigate the consequences of and countermeasures to abnormal cholesterol levels. Among others, various treatments of high blood cholesterol levels can be simulated, e.g., with commonly prescribed de novo cholesterol synthesis inhibitors.

  2. Comparison of different blood compartments for the detection of circulating DNA using a rat model of Pneumocystis pneumonia.

    PubMed

    Fréalle, E; Gantois, N; Aliouat-Denis, C M; Leroy, S; Zawadzki, C; Perkhofer, S; Aliouat, E M; Dei-Cas, E

    2015-09-01

    Pneumocystis is mostly found in the alveolar spaces, but circulation of viable organisms also occurs and suggests that the detection of DNA in blood could be used as a noninvasive procedure to improve the diagnosis of Pneumocystis pneumonia (PcP). In order to determine the optimal compartment for Pneumocystis DNA detection, we used a rat model of PcP and tested the presence of Pneumocystis with a quantitative mtLSU targeting real-time PCR in four blood compartments: whole blood, clot, serum and Platelet-Rich-Plasma (PRP). All samples from 4 Pneumocystis-free control rats were negative. Pneumocystis was detected in 79, 64, 57, and 57% of samples from 14 PcP rats, respectively, but DNA release was not related to pulmonary loads. These data confirm the potential usefulness of Pneumocystis DNA detection in the blood for PcP diagnosis and suggest that whole blood could be the most appropriate compartment for Pneumocystis detection.

  3. Percent body fat via DEXA: comparison with a four-compartment model.

    PubMed

    Van Der Ploeg, Grant E; Withers, Robert T; Laforgia, Joe

    2003-02-01

    This study compared body composition by dual-energy X-ray absorptiometry (DEXA; Lunar DPX-L) with that via a four-compartment (4C; water, bone mineral mass, fat, and residual) model. Relative body fat was determined for 152 healthy adults [30.0 +/- 11.1 (SD) yr; 75.10 +/- 14.88 kg; 176.3 +/- 8.7 cm] aged from 18 to 59 yr. The 4C approach [20.7% body fat (%BF)] resulted in a significantly (P < 0.001) higher mean %BF compared with DEXA (18.9% BF), with intraindividual variations ranging from -2.6 to 7.3% BF. Linear regression and a Bland and Altman plot demonstrated the tendency for DEXA to progressively underestimate the %BF of leaner individuals compared with the criterion 4C model (4C %BF = 0.862 x DEXA %BF + 4.417; r(2) = 0.952, standard error of estimate = 1.6% BF). This bias was not attributable to variations in fat-free mass hydration but may have been due to beam-hardening errors that resulted from differences in anterior-posterior tissue thickness.

  4. A NOVEL PNYSIOLOGICALLY BASED PHARMACOKINETIC (PBPK) MODEL FOR DIMETHYLARSINIC ACID (DMA): THE LUNG AS A STORAGE COMPARTMENT

    EPA Science Inventory

    A NOVEL PHYSIOLOGICALLY-BASED PHARMACOKINETIC (PBPK) MODEL FOR DIMETHYLARSINIC ACID (DMA): THE LUNG AS A STORAGE COMPARTMENT. Evans, M.V., Hughes, M.F., and Kenyon, E.M. USEPA, ORD, NHEERL, RTP, NC 27711

    DMA is the major methylated metabolite of inorganic arsenic, a kno...

  5. Efficacy of intermittent versus continuous administration of netilmicin in a two-compartment in vitro model.

    PubMed Central

    Blaser, J; Stone, B B; Zinner, S H

    1985-01-01

    Several aminoglycoside dosage regimens were studied in a kinetic in vitro model. Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, and Staphylococcus aureus were exposed in serially placed artificial capillary units to netilmicin concentrations that changed based on human two-compartment pharmacokinetics. The same total dose per 24 h was administered as a continuous infusion (3.7 micrograms/ml) or in 1-h infusions given every 24 (24 micrograms/ml) or 8 h (8 micrograms/ml). The once daily administration showed the best response in terms of either faster killing of E. coli, K. pneumoniae, and S. aureus or greater reduction of the inocula of P. aeruginosa. After 28 h of treatment, however, all regimens reduced the nonpseudomonads by more than 99.99%, whereas all three P. aeruginosa strains regrew to greater than 10(8) CFU/ml due to selection of resistant subpopulations. In contrast to the bactericidal effect of the first dose, no killing occurred after subsequent doses if the ratio of peak drug concentration to MIC was low (less than or equal to 6). These results support the concept of administering high doses of aminoglycosides once every 24 h. PMID:3922294

  6. Radionuclide transport and uptake in coastal aquatic ecosystems: a comparison of a 3D dynamic model and a compartment model.

    PubMed

    Erichsen, Anders Christian; Konovalenko, Lena; Møhlenberg, Flemming; Closter, Rikke Margrethe; Bradshaw, Clare; Aquilonius, Karin; Kautsky, Ulrik

    2013-05-01

    In safety assessments of underground radioactive waste repositories, understanding radionuclide fate in ecosystems is necessary to determine the impacts of potential releases. Here, the reliability of two mechanistic models (the compartmental K-model and the 3D dynamic D-model) in describing the fate of radionuclides released into a Baltic Sea bay is tested. Both are based on ecosystem models that simulate the cycling of organic matter (carbon). Radionuclide transfer is linked to adsorption and flows of carbon in food chains. Accumulation of Th-230, Cs-135, and Ni-59 in biological compartments was comparable between the models and site measurements despite differences in temporal resolution, biological state variables, and partition coefficients. Both models provided confidence limits for their modeled concentration ratios, an improvement over models that only estimate means. The D-model enables estimates at high spatio-temporal resolution. The K-model, being coarser but faster, allows estimates centuries ahead. Future developments could integrate the two models to take advantage of their respective strengths.

  7. A compartment model of VEGF distribution in blood, healthy and diseased tissues

    PubMed Central

    Stefanini, Marianne O; Wu, Florence TH; Mac Gabhann, Feilim; Popel, Aleksander S

    2008-01-01

    Background Angiogenesis is a process by which new capillaries are formed from pre-existing blood vessels in physiological (e.g., exercise, wound healing) or pathological (e.g., ischemic limb as in peripheral arterial disease, cancer) contexts. This neovascular mechanism is mediated by the vascular endothelial growth factor (VEGF) family of cytokines. Although VEGF is often targeted in anti-angiogenic therapies, there is little knowledge about how its concentration may vary between tissues and the vascular system. A compartment model is constructed to study the VEGF distribution in the tissue (including matrix-bound, cell surface receptor-bound and free VEGF isoforms) and in the blood. We analyze the sensitivity of this distribution to the secretion rate, clearance rate and vascular permeability of VEGF. Results We find that, in a physiological context, VEGF concentration varies approximately linearly with the VEGF secretion rate. VEGF concentration in blood but not in tissue is dependent on the vascular permeability of healthy tissue. Model simulations suggest that relative VEGF increases are similar in blood and tissue during exercise and return to baseline within several hours. In a pathological context (tumor), we find that blood VEGF concentration is relatively insensitive to increased vascular permeability in tumors, to the secretion rate of VEGF by tumors and to the clearance. However, it is sensitive to the vascular permeability in the healthy tissue. Finally, the VEGF distribution profile in healthy tissue reveals that about half of the VEGF is complexed with the receptor tyrosine kinase VEGFR2 and the co-receptor Neuropilin-1. In diseased tissues, this binding can be reduced to 15% while VEGF bound to the extracellular matrix and basement membranes increases. Conclusion The results are of importance for physiological conditions (e.g., exercise) and pathological conditions (e.g., peripheral arterial disease, coronary artery disease, cancer). This

  8. Improved EEG source analysis using low-resolution conductivity estimation in a four-compartment finite element head model.

    PubMed

    Lew, Seok; Wolters, Carsten H; Anwander, Alfred; Makeig, Scott; MacLeod, Rob S

    2009-09-01

    Bioelectric source analysis in the human brain from scalp electroencephalography (EEG) signals is sensitive to geometry and conductivity properties of the different head tissues. We propose a low-resolution conductivity estimation (LRCE) method using simulated annealing optimization on high-resolution finite element models that individually optimizes a realistically shaped four-layer volume conductor with regard to the brain and skull compartment conductivities. As input data, the method needs T1- and PD-weighted magnetic resonance images for an improved modeling of the skull and the cerebrospinal fluid compartment and evoked potential data with high signal-to-noise ratio (SNR). Our simulation studies showed that for EEG data with realistic SNR, the LRCE method was able to simultaneously reconstruct both the brain and the skull conductivity together with the underlying dipole source and provided an improved source analysis result. We have also demonstrated the feasibility and applicability of the new method to simultaneously estimate brain and skull conductivity and a somatosensory source from measured tactile somatosensory-evoked potentials of a human subject. Our results show the viability of an approach that computes its own conductivity values and thus reduces the dependence on assigning values from the literature and likely produces a more robust estimate of current sources. Using the LRCE method, the individually optimized four-compartment volume conductor model can, in a second step, be used for the analysis of clinical or cognitive data acquired from the same subject.

  9. Dual-input two-compartment pharmacokinetic model of dynamic contrast-enhanced magnetic resonance imaging in hepatocellular carcinoma

    PubMed Central

    Yang, Jian-Feng; Zhao, Zhen-Hua; Zhang, Yu; Zhao, Li; Yang, Li-Ming; Zhang, Min-Ming; Wang, Bo-Yin; Wang, Ting; Lu, Bao-Chun

    2016-01-01

    AIM: To investigate the feasibility of a dual-input two-compartment tracer kinetic model for evaluating tumorous microvascular properties in advanced hepatocellular carcinoma (HCC). METHODS: From January 2014 to April 2015, we prospectively measured and analyzed pharmacokinetic parameters [transfer constant (Ktrans), plasma flow (Fp), permeability surface area product (PS), efflux rate constant (kep), extravascular extracellular space volume ratio (ve), blood plasma volume ratio (vp), and hepatic perfusion index (HPI)] using dual-input two-compartment tracer kinetic models [a dual-input extended Tofts model and a dual-input 2-compartment exchange model (2CXM)] in 28 consecutive HCC patients. A well-known consensus that HCC is a hypervascular tumor supplied by the hepatic artery and the portal vein was used as a reference standard. A paired Student’s t-test and a nonparametric paired Wilcoxon rank sum test were used to compare the equivalent pharmacokinetic parameters derived from the two models, and Pearson correlation analysis was also applied to observe the correlations among all equivalent parameters. The tumor size and pharmacokinetic parameters were tested by Pearson correlation analysis, while correlations among stage, tumor size and all pharmacokinetic parameters were assessed by Spearman correlation analysis. RESULTS: The Fp value was greater than the PS value (FP = 1.07 mL/mL per minute, PS = 0.19 mL/mL per minute) in the dual-input 2CXM; HPI was 0.66 and 0.63 in the dual-input extended Tofts model and the dual-input 2CXM, respectively. There were no significant differences in the kep, vp, or HPI between the dual-input extended Tofts model and the dual-input 2CXM (P = 0.524, 0.569, and 0.622, respectively). All equivalent pharmacokinetic parameters, except for ve, were correlated in the two dual-input two-compartment pharmacokinetic models; both Fp and PS in the dual-input 2CXM were correlated with Ktrans derived from the dual-input extended Tofts model

  10. Theoretical Compartment Modeling of DCE-MRI Data Based on the Transport across Physiological Barriers in the Brain

    PubMed Central

    Fanea, Laura; David, Leontin I.; Lebovici, Andrei; Carbone, Francesca; Sfrangeu, Silviu A.

    2012-01-01

    Neurological disorders represent major causes of lost years of healthy life and mortality worldwide. Development of their quantitative interdisciplinary in vivo evaluation is required. Compartment modeling (CM) of brain data acquired in vivo using magnetic resonance imaging techniques with clinically available contrast agents can be performed to quantitatively assess brain perfusion. Transport of 1H spins in water molecules across physiological compartmental brain barriers in three different pools was mathematically modeled and theoretically evaluated in this paper and the corresponding theoretical compartment modeling of dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) data was analyzed. The pools considered were blood, tissue, and cerebrospinal fluid (CSF). The blood and CSF data were mathematically modeled assuming continuous flow of the 1H spins in these pools. Tissue data was modeled using three CMs. Results in this paper show that transport across physiological brain barriers such as the blood to brain barrier, the extracellular space to the intracellular space barrier, or the blood to CSF barrier can be evaluated quantitatively. Statistical evaluations of this quantitative information may be performed to assess tissue perfusion, barriers' integrity, and CSF flow in vivo in the normal or disease-affected brain or to assess response to therapy. PMID:22666304

  11. Preliminary Modelling of Mass Flux at the Surface of Plant Leaves within the MELiSSA Higher Plant Compartments

    NASA Astrophysics Data System (ADS)

    Holmberg, Madeleine; Paille, Christel; Lasseur, Christophe

    The ESA project Micro Ecological Life Support System Alternative (MELiSSA) is an ecosystem of micro-organisms and higher plants, constructed with the objective of being operated as a tool to understand artificial ecosystems to be used for a long-term or permanent manned planetary base (e.g. Moon or Mars). The purpose of such a system is to provide for generation of food, water recycling, atmospheric regeneration and waste management within defined standards of quality and reliability. As MELiSSA consists of individual compartments which are connected to each other, the robustness of the system is fully dependent on the control of each compartment, as well as the flow management between them. Quality of consumables and reliability of the ecosystem rely on the knowledge, understanding and control of each of the components. This includes the full understanding of all processes related to the higher plants. To progress in that direction, this paper focuses on the mechanical processes driving the gas and liquid exchanges between the plant leaf and its environment. The process responsible for the mass transfer on the surface of plant leaves is diffusion. The diffusion flux is dependent on the behaviour of the stoma of the leaf and also on the leaf boundary layer (BL). In this paper, the physiology of the leaf is briefly examined in order to relate parameters such as light quality, light quantity, CO2 concentration, temperature, leaf water potential, humidity, vapour pressure deficit (VPD) gradients and pollutants to the opening or closing of stomata. The diffusion process is described theoretically and the description is compared to empirical approaches. The variables of the BL are examined and the effect airflow in the compartment has on the BL is investigated. Also presented is the impact changes in different environmental parameters may have on the fluid exchanges. Finally, some tests, to evaluate the accuracy of the concluded model, are suggested.

  12. Modeling the Interaction between β-Amyloid Aggregates and Choline Acetyltransferase Activity and Its Relation with Cholinergic Dysfunction through Two-Enzyme/Two-Compartment Model

    PubMed Central

    Fgaier, Hedia; Mustafa, Ibrahim H. I.; Awad, Asmaa A. R.; Elkamel, Ali

    2015-01-01

    The effect of β-amyloid aggregates on activity of choline acetyltransferase (ChAT) which is responsible for synthesizing acetylcholine (ACh) in human brain is investigated through the two-enzyme/two-compartment (2E2C) model where the presynaptic neuron is considered as compartment 1 while both the synaptic cleft and the postsynaptic neuron are considered as compartment 2 through suggesting three different kinetic mechanisms for the inhibition effect. It is found that the incorporation of ChAT inhibition by β-amyloid aggregates into the 2E2C model is able to yield dynamic solutions for concentrations of generated β-amyloid, ACh, choline, acetate, and pH in addition to the rates of ACh synthesis and ACh hydrolysis in compartments 1 and 2. It is observed that ChAT activity needs a high concentration of β-amyloid aggregates production rate. It is found that ChAT activity is reduced significantly when neurons are exposed to high levels of β-amyloid aggregates leading to reduction in levels of ACh which is one of the most significant physiological symptoms of AD. Furthermore, the system of ACh neurocycle is dominated by the oscillatory behavior when ChAT enzyme is completely inhibited by β-amyloid. It is observed that the direct inactivation of ChAT by β-amyloid aggregates may be a probable mechanism contributing to the development of AD. PMID:26413144

  13. Comparison of the Adipose and Luminal Mammary Gland Compartment as Orthotopic Inoculation Sites in a 4T1-Based Immunocompetent Preclinical Model for Triple-Negative Breast Cancer.

    PubMed

    Steenbrugge, Jonas; Breyne, Koen; Denies, Sofie; Dekimpe, Melissa; Demeyere, Kristel; De Wever, Olivier; Vermeulen, Peter; Van Laere, Steven; Sanders, Niek N; Meyer, Evelyne

    2016-12-01

    Breast tumorigenesis is classically studied in mice by inoculating tumor cells in the fat pad, the adipose compartment of the mammary gland. Alternatively, the mammary ducts, which constitute the luminal mammary gland compartment, also provide a suitable inoculation site to induce breast cancer in murine models. The microenvironments in these compartments influence tumor cell progression, yet this effect has not been investigated in an immunocompetent context. Here, we compared both mammary gland compartments as distinct inoculation sites, taking into account the immunological aspect by inoculating 4T1 tumor cells in immunocompetent mice. Following tumor cell inoculation in the adipose compartment of non-pretreated/naive, hormonally pretreated/naive and non-pretreated/lactating mice, the primary tumors developed similarly. However, a slower onset of primary tumor growth was found after inoculations in the luminal compartment of non-pretreated/lactating mice. Despite this difference in tumor development rate, metastasis to the liver and lungs was equally observed and was accompanied by lymphatic spreading of tumor cells and progressive splenomegaly with both inoculation types. Chitinase 3-like 1 (CHI3L1) and lipocalin 2 (LCN2) served as innovative biomarkers for disease progression showing increased levels in primary tumors and sera of the non-pretreated/lactating inoculation groups. A slower increase in circulating CHI3L1 but not LCN2 levels, was observed after inoculations in the luminal compartment which corroborated the slower tumor development at this inoculation site. Our results highlight the critical impact of different mammary gland compartments on tumor development in syngeneic murine models and support the use of novel tumor progression biomarkers in an immune-competent environment.

  14. The composite neuron: a realistic one-compartment Purkinje cell model suitable for large-scale neuronal network simulations.

    PubMed

    Coop, A D; Reeke, G N

    2001-01-01

    We present a simple method for the realistic description of neurons that is well suited to the development of large-scale neuronal network models where the interactions within and between neural circuits are the object of study rather than the details of dendritic signal propagation in individual cells. Referred to as the composite approach, it combines in a one-compartment model elements of both the leaky integrator cell and the conductance-based formalism of Hodgkin and Huxley (1952). Composite models treat the cell membrane as an equivalent circuit that contains ligand-gated synaptic, voltage-gated, and voltage- and concentration-dependent conductances. The time dependences of these various conductances are assumed to correlate with their spatial locations in the real cell. Thus, when viewed from the soma, ligand-gated synaptic and other dendritically located conductances can be modeled as either single alpha or double exponential functions of time, whereas, with the exception of discharge-related conductances, somatic and proximal dendritic conductances can be well approximated by simple current-voltage relationships. As an example of the composite approach to neuronal modeling we describe a composite model of a cerebellar Purkinje neuron.

  15. 76 FR 44246 - Special Conditions: Boeing Model 747-8 Series Airplanes; Overhead Flight Attendant Rest Compartment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-25

    ... minute quantities of flammable fluids (e.g., finger nail polish and aerosol hairspray) that would pose no... requirements were developed. This requirement originated from a concern that a fire in an unoccupied overhead... agent originating in the OFAR compartment from entering any other compartment occupied by crewmembers...

  16. An Accumulated Damage Model for Blast Propagation in Compartmented Structures with Progressively Failing Thin Bulkheads

    DTIC Science & Technology

    2009-12-01

    freedom models subjected to blast loading, Intern. J. Impact Engng 34(4), 823–842. Gelfand, B. E. & Silnikov , M. V . (2004) Explosions and Blast...models for weapon–target interaction. v DSTO–TR–2365 vi DSTO–TR–2365 Contents 1 Introduction 1 2 Mathematical model 2 3 Numerical algorithm 5 4...loading scenarios [Baker 1973, Baker et al. 1983, Lloyd 1998, Gelfand & Silnikov 2004, Fallah & Louca 2007]. It is assumed that the time history of the

  17. The effect of infected external computers on the spread of viruses: A compartment modeling study

    NASA Astrophysics Data System (ADS)

    Yang, Lu-Xing; Yang, Xiaofan

    2013-12-01

    Inevitably, there exist infected computers outside of the Internet. This paper aims to understand how infected external computers affect the spread of computer viruses. For that purpose, a new virus-antivirus spreading model, which takes into account the effect of infected/immune external computers, is established. A systematic study shows that, unlike most previous models, the proposed model admits no virus-free equilibrium and admits a globally asymptotically stable viral equilibrium. This result implies that it would be practically impossible to eradicate viruses on the Internet. As a result, inhibiting the virus prevalence to below an acceptable level would be the next best thing. A theoretical study reveals the effect of different parameters on the steady virus prevalence. On this basis, a number of suggestions are made so as to contain virus spreading.

  18. The TERENO-preAlpine Observatory: A Research Infrastructure for Hydrometeorological Observation and -Modeling across Compartments and Scales

    NASA Astrophysics Data System (ADS)

    Kunstmann, H.; Beck, C.; Brosy, C.; Chwala, C.; Emeis, S.; Fersch, B.; Garvelmann, J.; Gasche, R.; Jahn, C.; Junkermann, W.; Keis, F.; Kiese, R.; Krieg, R.; Mauder, M.; Ralf, M.; Neidl, F.; Philipp, A.; Schäfer, K.; Schmid, H. P. E.; Völksch, I.; Warscher, M.; Werhahn, J.; Wolf, B.; Senatore, A.; Rödiger, T.

    2015-12-01

    The improved understanding of the interlinked atmospheric and terrestrial hydrological processes requires concerted and compartment-crossing observation and -modeling efforts. Through the TERENO preAlpine Observatory, located in the southern Bavarian region of Germany, comprehensive technical infrastructure is being established to allow joint analyses of water-, energy- and nutrient fluxes. The observatory extends from the Ammergau mountains in the South till Lake Ammersee in the North. The observatory is designated as an international research platform, open for participation and integration. The technical infrastructure consists of a multitude of precipitation gauges at different altitudes, an X-band radar, and a set of commercial microwave radio links allowing to derive line integrated precipitation estimates, numerous snow monitoring stations, a SnowPack Analyzer, neutron based SnowFox devices, as well as a snow melt lysimeter and time-lapse photography. For the quantification of the combined water and energy fluxes, three eddy covariance systems including four-component net-radiometers and soil-heat flux instrumentation are operated. Soil moisture patterns and dynamics are measured with a wireless sensor network consisting of 55 in-situ soil moisture profiles, a cosmic ray probe probe and 36 precision weighing vegetated lysimeters at different locations and altitudes. Groundwater dynamics and hydrogeochemical composition of the two main local aquifers are monitored at five observation wells as well as streamflow at three weirs at various cross sections. Additionally, stable water isotopes are analyzed. The operational monitoring is complemented by intensive measurement campaigns, like the ScaleX campaign in June and July 2015 for which we present first results. Here, additional remote sensing measurements of atmospheric wind, humidity and temperature profiles are performed, which are complemented by micro-light aircraft- and UAV-based remote sensing for three

  19. Machine learning based compartment models with permeability for white matter microstructure imaging.

    PubMed

    Nedjati-Gilani, Gemma L; Schneider, Torben; Hall, Matt G; Cawley, Niamh; Hill, Ioana; Ciccarelli, Olga; Drobnjak, Ivana; Wheeler-Kingshott, Claudia A M Gandini; Alexander, Daniel C

    2017-04-15

    Some microstructure parameters, such as permeability, remain elusive because mathematical models that express their relationship to the MR signal accurately are intractable. Here, we propose to use computational models learned from simulations to estimate these parameters. We demonstrate the approach in an example which estimates water residence time in brain white matter. The residence time τi of water inside axons is a potentially important biomarker for white matter pathologies of the human central nervous system, as myelin damage is hypothesised to affect axonal permeability, and thus τi. We construct a computational model using Monte Carlo simulations and machine learning (specifically here a random forest regressor) in order to learn a mapping between features derived from diffusion weighted MR signals and ground truth microstructure parameters, including τi. We test our numerical model using simulated and in vivo human brain data. Simulation results show that estimated parameters have strong correlations with the ground truth parameters (R(2)={0.88,0.95,0.82,0.99}) for volume fraction, residence time, axon radius and diffusivity respectively), and provide a marked improvement over the most widely used Kärger model (R(2)={0.75,0.60,0.11,0.99}). The trained model also estimates sensible microstructure parameters from in vivo human brain data acquired from healthy controls, matching values found in literature, and provides better reproducibility than the Kärger model on both the voxel and ROI level. Finally, we acquire data from two Multiple Sclerosis (MS) patients and compare to the values in healthy subjects. We find that in the splenium of corpus callosum (CC-S) the estimate of the residence time is 0.57±0.05s for the healthy subjects, while in the MS patient with a lesion in CC-S it is 0.33±0.12s in the normal appearing white matter (NAWM) and 0.19±0.11s in the lesion. In the corticospinal tracts (CST) the estimate of the residence time is 0.52±0

  20. Computer Modeling of Sand Transport on Mars Using a Compart-Mentalized Fluids Algorithm (CFA)

    NASA Technical Reports Server (NTRS)

    Marshall, J.; Stratton, D.

    1999-01-01

    It has been postulated that aeolian transport on Mars may be significantly different from that on Earth. From laboratory experiments simulating martian grain transport [2], it has been observed that (saltating) grains striking the bed can cause hundreds of secondary reptation trajectories when impact occurs at speeds postulated for Mars. Some of the ballistically induced trajectories "die ouf' and effectively join the ranks on the creep population that is merely nudged along by impact. Many of the induced reptation trajectories, however, are sufficiently high for the grains to become part of the saltation load (it is irrelevant to the boundary layer how a grain attained its initial lift force). When these grains, in turn, strike the surface, they too are capable of inducing more reptating grains. This cascading effect has been discussed in connection with terrestrial aeolian transport in an attempt to dispel the notion that sand motion is divisible only into creep and saltation loads. On Earth, only a few grains are splashed by impact. On Mars, it may be hundreds. We developed a computer model to address this phenomenon because there are some important ramifications: First, this ratio may mean that martian aeolian transport is dominated by reptation flux rather than saltation. On Earth, the flux would be a roughly balanced mixture between reptation/creep and saltation. On Venus, there would be no transport other than by saltation. In other words, an understanding of planetary aeolian processes may not be necessarily understood by extrapolating from the "Earth case", with only gravity and atmospheric density/viscosity being considered as variables. Second, the reptation flux on Mars may be self sustaining, so that little input is required by the wind once transport has been initiated. The number of grains saturating the boundary layer near the bed may mean that average grain speed on Mars might conceivably be less than that on Earth. This would say much for models

  1. Multi-compartment modelling for aquifer parameter estimation using natural tracers in non-steady flow

    NASA Astrophysics Data System (ADS)

    Adar, E.; Sorek, S.

    A method is developed for aquifer parameter estimation incorporating dissolved hydrochemical constituents and environmental isotopes. This model is developed for basins with lack of hydrological information but with enough wells to allow for hydraulic head measurements and water sampling for chemical and isotoic analyses. It was developed for aquifer systems with observed hydraulic head fluctuations. The model is based on a distributed parameter approach in which the aquifer is represented by a finte number of cells. Inflows through external aquifer boundaries and internal fluxes are evaluated by optimizing a set of mass balance equations expressing the conservation of water, isotopes and dissolved chemicals. Storativity and transmissivity coefficients are then evaluated by the previously calculated flow components and the periodic changes in hydraulic heads. This paper presents a methodology to enhance the accuracy of estimated physical parameters in heterogeneous and anisotropic aquifers by adding chemical and isotopic information.

  2. Action potential initiation in a two-compartment model of pyramidal neuron mediated by dendritic Ca(2+) spike.

    PubMed

    Yi, Guosheng; Wang, Jiang; Wei, Xile; Deng, Bin

    2017-04-03

    Dendritic Ca(2+) spike endows cortical pyramidal cell with powerful ability of synaptic integration, which is critical for neuronal computation. Here we propose a two-compartment conductance-based model to investigate how the Ca(2+) activity of apical dendrite participates in the action potential (AP) initiation to affect the firing properties of pyramidal neurons. We have shown that the apical input with sufficient intensity triggers a dendritic Ca(2+) spike, which significantly boosts dendritic inputs as it propagates to soma. Such event instantaneously shifts the limit cycle attractor of the neuron and results in a burst of APs, which makes its firing rate reach a plateau steady-state level. Delivering current to two chambers simultaneously increases the level of neuronal excitability and decreases the threshold of input-output relation. Here the back-propagating APs facilitate the initiation of dendritic Ca(2+) spike and evoke BAC firing. These findings indicate that the proposed model is capable of reproducing in vitro experimental observations. By determining spike initiating dynamics, we have provided a fundamental link between dendritic Ca(2+) spike and output APs, which could contribute to mechanically interpreting how dendritic Ca(2+) activity participates in the simple computations of pyramidal neuron.

  3. Action potential initiation in a two-compartment model of pyramidal neuron mediated by dendritic Ca2+ spike

    PubMed Central

    Yi, Guosheng; Wang, Jiang; Wei, Xile; Deng, Bin

    2017-01-01

    Dendritic Ca2+ spike endows cortical pyramidal cell with powerful ability of synaptic integration, which is critical for neuronal computation. Here we propose a two-compartment conductance-based model to investigate how the Ca2+ activity of apical dendrite participates in the action potential (AP) initiation to affect the firing properties of pyramidal neurons. We have shown that the apical input with sufficient intensity triggers a dendritic Ca2+ spike, which significantly boosts dendritic inputs as it propagates to soma. Such event instantaneously shifts the limit cycle attractor of the neuron and results in a burst of APs, which makes its firing rate reach a plateau steady-state level. Delivering current to two chambers simultaneously increases the level of neuronal excitability and decreases the threshold of input-output relation. Here the back-propagating APs facilitate the initiation of dendritic Ca2+ spike and evoke BAC firing. These findings indicate that the proposed model is capable of reproducing in vitro experimental observations. By determining spike initiating dynamics, we have provided a fundamental link between dendritic Ca2+ spike and output APs, which could contribute to mechanically interpreting how dendritic Ca2+ activity participates in the simple computations of pyramidal neuron. PMID:28367964

  4. An Asymptotic Analysis of a 2-D Model of Dynamically Active Compartments Coupled by Bulk Diffusion

    NASA Astrophysics Data System (ADS)

    Gou, J.; Ward, M. J.

    2016-08-01

    A class of coupled cell-bulk ODE-PDE models is formulated and analyzed in a two-dimensional domain, which is relevant to studying quorum-sensing behavior on thin substrates. In this model, spatially segregated dynamically active signaling cells of a common small radius ɛ ≪ 1 are coupled through a passive bulk diffusion field. For this coupled system, the method of matched asymptotic expansions is used to construct steady-state solutions and to formulate a spectral problem that characterizes the linear stability properties of the steady-state solutions, with the aim of predicting whether temporal oscillations can be triggered by the cell-bulk coupling. Phase diagrams in parameter space where such collective oscillations can occur, as obtained from our linear stability analysis, are illustrated for two specific choices of the intracellular kinetics. In the limit of very large bulk diffusion, it is shown that solutions to the ODE-PDE cell-bulk system can be approximated by a finite-dimensional dynamical system. This limiting system is studied both analytically, using a linear stability analysis and, globally, using numerical bifurcation software. For one illustrative example of the theory, it is shown that when the number of cells exceeds some critical number, i.e., when a quorum is attained, the passive bulk diffusion field can trigger oscillations through a Hopf bifurcation that would otherwise not occur without the coupling. Moreover, for two specific models for the intracellular dynamics, we show that there are rather wide regions in parameter space where these triggered oscillations are synchronous in nature. Unless the bulk diffusivity is asymptotically large, it is shown that a diffusion-sensing behavior is possible whereby more clustered spatial configurations of cells inside the domain lead to larger regions in parameter space where synchronous collective oscillations between the small cells can occur. Finally, the linear stability analysis for these cell

  5. Radiological assessment by compartment model POSEIDON-R of radioactivity released in the ocean following Fukushima Daiichi accident

    NASA Astrophysics Data System (ADS)

    Bezhenar, Roman; Maderich, Vladimir; Heling, Rudie; Jung, Kyung Tae; Myoung, Jung-Goo

    2013-04-01

    The modified compartment model POSEIDON-R (Lepicard et al, 2004), was applied to the North-Western Pacific and adjacent seas. It is for the first time, that a compartment model was used in this region, where 25 Nuclear Power Plants (NPP) are operated. The aim of this study is to perform a radiological assessment of the releases of radioactivity due to the Fukushima Daiichi accident. The model predicts the dispersion of radioactivity in water column and in the sediments, and the transfer of radionuclides throughout the marine food web, and the subsequent doses to the population due to the consumption of fishery products. A generic predictive dynamical food-chain model is used instead of concentration factor (CF) approach. The radionuclide uptake model for fish has as central feature the accumulation of radionuclides in the target tissue. Three layer structure of the water column makes it possible to describe deep-water transport adequately. In total 175 boxes cover the Northwestern Pacific, the East China Sea, and the Yellow Sea and East/Japan Sea. Water fluxes between boxes were calculated by averaging three-dimensional currents obtained by hydrodynamic model ROMS over a 10-years period. Tidal mixing between boxes was parameterized. The model was validated on observation data on the Cs-137 in water for the period 1945-2004. The source terms from nuclear weapon tests are regional source term from the bomb tests on Atoll Enewetak and Atoll Bikini and global deposition from weapons tests. The correlation coefficient between predicted and observed concentrations of Cs-137 in the surface water is 0.925 and RMSE=1.43 Bq/m3. A local-scale coastal box was used according POSEIDON's methodology to describe local processes of activity transport, deposition and food web around the Fukushima Daiichi NPP. The source term to the ocean from the Fukushima accident includes a 10-days release of Cs-134 (5 PBq) and Cs-137 (4 PBq) directly into the ocean and 6 and 5 PBq of Cs-134 and

  6. Validity Of Bmi-Based Body Fat Equations In Men And Women: A Four-Compartment Model Comparison.

    PubMed

    Nickerson, Brett S; Esco, Michael R; Bishop, Phillip A; Fedewa, Michael V; Snarr, Ronald L; Kliszczewicz, Brian M; Park, Kyung-Shin

    2016-12-20

    The purpose of this study was to compare body mass index (BMI)-based body fat percentage (BF%) equations and skinfolds to a four-compartment (4C) model in men and women. One hundred and thirty adults (63 women and 67 men) volunteered to participate (age = 23±5 years). BMI was calculated as weight (kg) divided by height squared (m). BF% was predicted with the BMI-based equations of Jackson et al. (BMIJA), Deurenberg et al. (BMIDE), Gallagher et al. (BMIGA), Zanovec et al. (BMIZA), Womersley and Durnin (BMIWO) and from 7-site skinfolds using the generalized skinfold equation of Jackson et al. (SF7JP). 4C model BF% was the criterion and derived from underwater weighing for body volume, dual energy X-ray absorptiometry for bone mineral content, and bioimpedance spectroscopy for total body water. The constant error (CE) was not significantly different for BMIZA compared to the 4C model (p=0.74; CE = -0.2%). However, BMIJA, BMIDE, BMIGA, and BMIWO produced significantly higher mean values than the 4C model (all p<0.001; CEs = 1.8-3.2%) while SF7JP was significantly lower (p<0.001; CE = -4.8%). The standard error of estimate (SEE) ranged from 3.4 (SF7JP) to 6.4% (BMIJA) while the total error varied from 6.0 (SF7JP) to 7.3% (BMIJA). The 95% limits of agreement were smallest for SF7JP (±7.2%) and widest for BMIJA (±13.5%). Although the BMI-based equations produced similar group mean values as the 4C model, SF7JP produced the smallest individual errors. Therefore, SF7JP is recommended over the BMI-based equations, but practitioners should consider the associated CE.

  7. 1D-3D hybrid modeling-from multi-compartment models to full resolution models in space and time.

    PubMed

    Grein, Stephan; Stepniewski, Martin; Reiter, Sebastian; Knodel, Markus M; Queisser, Gillian

    2014-01-01

    Investigation of cellular and network dynamics in the brain by means of modeling and simulation has evolved into a highly interdisciplinary field, that uses sophisticated modeling and simulation approaches to understand distinct areas of brain function. Depending on the underlying complexity, these models vary in their level of detail, in order to cope with the attached computational cost. Hence for large network simulations, single neurons are typically reduced to time-dependent signal processors, dismissing the spatial aspect of each cell. For single cell or networks with relatively small numbers of neurons, general purpose simulators allow for space and time-dependent simulations of electrical signal processing, based on the cable equation theory. An emerging field in Computational Neuroscience encompasses a new level of detail by incorporating the full three-dimensional morphology of cells and organelles into three-dimensional, space and time-dependent, simulations. While every approach has its advantages and limitations, such as computational cost, integrated and methods-spanning simulation approaches, depending on the network size could establish new ways to investigate the brain. In this paper we present a hybrid simulation approach, that makes use of reduced 1D-models using e.g., the NEURON simulator-which couples to fully resolved models for simulating cellular and sub-cellular dynamics, including the detailed three-dimensional morphology of neurons and organelles. In order to couple 1D- and 3D-simulations, we present a geometry-, membrane potential- and intracellular concentration mapping framework, with which graph- based morphologies, e.g., in the swc- or hoc-format, are mapped to full surface and volume representations of the neuron and computational data from 1D-simulations can be used as boundary conditions for full 3D simulations and vice versa. Thus, established models and data, based on general purpose 1D-simulators, can be directly coupled to the

  8. Compartment Model Predicts VEGF Secretion and Investigates the Effects of VEGF Trap in Tumor-Bearing Mice

    PubMed Central

    Finley, Stacey D.; Dhar, Manjima; Popel, Aleksander S.

    2013-01-01

    Angiogenesis, the formation of new blood vessels from existing vasculature, is important in tumor growth and metastasis. A key regulator of angiogenesis is vascular endothelial growth factor (VEGF), which has been targeted in numerous anti-angiogenic therapies aimed at inhibiting tumor angiogenesis. Systems biology approaches, including computational modeling, are useful for understanding this complex biological process and can aid in the development of novel and effective therapeutics that target the VEGF family of proteins and receptors. We have developed a computational model of VEGF transport and kinetics in the tumor-bearing mouse, which includes three-compartments: normal tissue, blood, and tumor. The model simulates human tumor xenografts and includes human (VEGF121 and VEGF165) and mouse (VEGF120 and VEGF164) isoforms. The model incorporates molecular interactions between these VEGF isoforms and receptors (VEGFR1 and VEGFR2), as well as co-receptors (NRP1 and NRP2). We also include important soluble factors: soluble VEGFR1 (sFlt-1) and α-2-macroglobulin. The model accounts for transport via macromolecular transendothelial permeability, lymphatic flow, and plasma clearance. We have fit the model to available in vivo experimental data on the plasma concentration of free VEGF Trap and VEGF Trap bound to mouse and human VEGF in order to estimate the rates at which parenchymal cells (myocytes and tumor cells) and endothelial cells secrete VEGF. Interestingly, the predicted tumor VEGF secretion rates are significantly lower (0.007–0.023 molecules/cell/s, depending on the tumor microenvironment) than most reported in vitro measurements (0.03–2.65 molecules/cell/s). The optimized model is used to investigate the interstitial and plasma VEGF concentrations and the effect of the VEGF-neutralizing agent, VEGF Trap (aflibercept). This work complements experimental studies performed in mice and provides a framework with which to examine the effects of anti

  9. Compartmented electrode structure

    DOEpatents

    Vissers, Donald R.; Shimotake, Hiroshi; Gay, Eddie C.; Martino, Fredric J.

    1977-06-14

    Electrodes for secondary electrochemical cells are provided with compartments for containing particles of the electrode reactant. The compartments are defined by partitions that are generally impenetrable to the particles of reactant and, in some instances, to the liquid electrolyte used in the cell. During cycling of the cell, reactant material initially loaded into a particular compartment is prevented from migrating and concentrating within the lower portion of the electrode or those portions of the electrode that exhibit reduced electrical resistance.

  10. Compilation of basal metabolic and blood perfusion rates in various multi-compartment, whole-body thermoregulation models

    NASA Astrophysics Data System (ADS)

    Shitzer, Avraham; Arens, Edward; Zhang, Hui

    2016-07-01

    The assignments of basal metabolic rates (BMR), basal cardiac output (BCO), and basal blood perfusion rates (BBPR) were compared in nine multi-compartment, whole-body thermoregulation models. The data are presented at three levels of detail: total body, specific body regions, and regional body tissue layers. Differences in the assignment of these quantities among the compared models increased with the level of detail, in the above order. The ranges of variability in the total body BMR was 6.5 % relative to the lowest value, with a mean of 84.3 ± 2 W, and in the BCO, it was 8 % with a mean of 4.70 ± 0.13 l/min. The least variability among the body regions is seen in the combined torso (shoulders, thorax, and abdomen: ±7.8 % BMR and ±5.9 % BBPR) and in the combined head (head, face, and neck ±9.9 % BMR and ±10.9 % BBPR), determined by the ratio of the standard deviation to the mean. Much more variability is apparent in the extremities with the most showing in the BMR of the feet (±117 %), followed by the BBPR in the arms (±61.3 %). In the tissue layers, most of the bone layers were assigned zero BMR and BBPR, except in the shoulders and in the extremities that were assigned non-zero values in a number of models. The next lowest values were assigned to the fat layers, with occasional zero values. Skin basal values were invariably non-zero but involved very low values in certain models, e.g., BBPR in the feet and the hands. Muscle layers were invariably assigned high values with the highest found in the thorax, abdomen, and legs. The brain, lung, and viscera layers were assigned the highest of all values of both basal quantities with those of the brain layers showing rather tight ranges of variability in both basal quantities. Average basal values of the "time-seasoned" models presented in this study could be useful as a first step in future modeling efforts subject to appropriate adjustment of values to conform to most recently available and reliable data.

  11. 76 FR 10482 - Special Conditions: Boeing Model 787-8 Airplane; Overhead Flightcrew-Rest Compartment Occupiable...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-25

    ... compartment. If a locking mechanism is installed, it must be capable of being unlocked from the outside... must be designed to minimize the possibility of blockage, which might result from fire, mechanical or... passenger cabin. 9. A means must be available for manual activation of an aural emergency alarm...

  12. Time-dependent diffusion in skeletal muscle with the random permeable barrier model (RPBM): Application to normal controls and chronic exertional compartment syndrome patients

    PubMed Central

    Sigmund, Eric E.; Novikov, Dmitry S.; Sui, Dabang; Ukpebor, Obehi; Baete, Steven; Babb, James S.; Liu, Kecheng; Feiweier, Thorsten; Kwon, Jane; Mcgorty, KellyAnne; Bencardino, Jenny; Fieremans, Els

    2014-01-01

    Purpose To collect diffusion tensor imaging (DTI) at multiple diffusion times Td in skeletal muscle in normal subjects and chronic exertional compartment syndrome (CECS) patients and analyze the data with the random permeable barrier model (RPBM) for biophysical specificity. Materials and Methods Using an IRB-approved HIPAA-compliant protocol, seven patients with clinical suspicion of CECS and eight healthy volunteers underwent DTI of the calf muscle in a Siemens MAGNETOM Verio 3-T scanner at rest and after treadmill exertion at 4 different diffusion times. Radial diffusion values λrad were computed for each of 7 different muscle compartments and analyzed with RPBM to produce estimates of free diffusivity D0, fiber diameter a, and permeability κ. Fiber diameter estimates were compared with measurements from literature autopsy reference for several compartments. Response factors (post/pre-exercise ratios) were computed and compared between normal controls and CECS patients using a mixed-model two-way analysis of variance. Results All subjects and muscle compartments showed nearly time-independent diffusion along and strongly time-dependent diffusion transverse to the muscle fibers. RPBM estimates of fiber diameter correlated well with corresponding autopsy reference. D0 showed significant (p<0.05) increases with exercise for volunteers, and a increased significantly (p<0.05) in volunteers. At the group level, response factors of all three parameters showed trends differentiating controls from CECS patients, with patients showing smaller diameter changes (p=0.07), and larger permeability increases (p=0.07) than controls. Conclusions Time-dependent diffusion measurements combined with appropriate tissue modeling can provide enhanced microstructural specificity for in vivo tissue characterization. In CECS patients, our results suggest that high-pressure interfiber edema elevates free diffusion and restricts exercise-induced fiber dilation. Such specificity may be

  13. Water compartments in cells.

    PubMed

    Fullerton, Gary D; Cameron, Ivan L

    2007-01-01

    Human experience in the macrobiological world leads scientists to visualize water compartments in cells analogous to the bladder in the human pelvis or ventricles in the brain. While such water-filled cellular compartments likely exist, the volume contributions are insignificant relative to those of biomolecular hydration compartments. The purpose of this chapter is to identify and categorize the molecular water compartments caused by proteins, the primary macromolecular components of cells. The categorical changes in free energy of water molecules on proteins cause these compartments to play dominant roles in osmoregulation and provide important adjuncts to fundamental understanding of osmosensing and osmosignaling mechanisms. Water compartments possess differences in molecular motion, enthalpy, entropy, freezing point depression, and other properties because of electrostatic interaction of polar water molecules with electric fields generated by covalently bound pairs of opposite charge caused by electronegative oxygen and nitrogen atoms of the protein. Macromolecules, including polypeptides, polynucleotides, and polysaccharides, are stiff molecular chains with restricted folding capacities due to inclusion of rigid ring structures or double amide bonds in the backbone sequence. This creates "irreducible spatial charge separation" between positive and negative partial charges, causing elevated electrostatic energy. In the fully hydrated in vivo state of living cells the high dielectric coefficient of water reduces protein electrostatic free energy by providing polar "water bridge networks" between charges, thereby creating four measurably different compartments of bound water with distinct free energy differences.

  14. Single compartment drug delivery

    PubMed Central

    Cima, Michael J.; Lee, Heejin; Daniel, Karen; Tanenbaum, Laura M.; Mantzavinou, Aikaterini; Spencer, Kevin C.; Ong, Qunya; Sy, Jay C.; Santini, John; Schoellhammer, Carl M.; Blankschtein, Daniel; Langer, Robert S.

    2014-01-01

    Drug design is built on the concept that key molecular targets of disease are isolated in the diseased tissue. Systemic drug administration would be sufficient for targeting in such a case. It is, however, common for enzymes or receptors that are integral to disease to be structurally similar or identical to those that play important biological roles in normal tissues of the body. Additionally, systemic administration may not lead to local drug concentrations high enough to yield disease modification because of rapid systemic metabolism or lack of sufficient partitioning into the diseased tissue compartment. This review focuses on drug delivery methods that physically target drugs to individual compartments of the body. Compartments such as the bladder, peritoneum, brain, eye and skin are often sites of disease and can sometimes be viewed as “privileged,” since they intrinsically hinder partitioning of systemically administered agents. These compartments have become the focus of a wide array of procedures and devices for direct administration of drugs. We discuss the rationale behind single compartment drug delivery for each of these compartments, and give an overview of examples at different development stages, from the lab bench to phase III clinical trials to clinical practice. We approach single compartment drug delivery from both a translational and a technological perspective. PMID:24798478

  15. DNA Virus Replication Compartments

    PubMed Central

    Schmid, Melanie; Speiseder, Thomas; Dobner, Thomas

    2014-01-01

    Viruses employ a variety of strategies to usurp and control cellular activities through the orchestrated recruitment of macromolecules to specific cytoplasmic or nuclear compartments. Formation of such specialized virus-induced cellular microenvironments, which have been termed viroplasms, virus factories, or virus replication centers, complexes, or compartments, depends on molecular interactions between viral and cellular factors that participate in viral genome expression and replication and are in some cases associated with sites of virion assembly. These virus-induced compartments function not only to recruit and concentrate factors required for essential steps of the viral replication cycle but also to control the cellular mechanisms of antiviral defense. In this review, we summarize characteristic features of viral replication compartments from different virus families and discuss similarities in the viral and cellular activities that are associated with their assembly and the functions they facilitate for viral replication. PMID:24257611

  16. Modeling of growth factor-receptor systems: from molecular-level protein interaction networks to whole-body compartment models

    PubMed Central

    Wu, Florence T.H.; Stefanini, Marianne O.; Mac Gabhann, Feilim; Popel, Aleksander S.

    2010-01-01

    Most physiological processes are subjected to molecular regulation by growth factors, which are secreted proteins that activate chemical signal transduction pathways through binding of specific cell-surface receptors. One particular growth factor system involved in the in vivo regulation of blood vessel growth is called the vascular endothelial growth factor (VEGF) system. Computational and numerical techniques are well-suited to handle the molecular complexity (the number of binding partners involved, including ligands, receptors, and inert binding sites) and multi-scale nature (intra-tissue vs. inter-tissue transport and local vs. systemic effects within an organism) involved in modeling growth factor system interactions and effects. This paper introduces a variety of in silico models that seek to recapitulate different aspects of VEGF system biology at various spatial and temporal scales: molecular-level kinetic models focus on VEGF ligand-receptor interactions at and near the endothelial cell surface; meso-scale single-tissue 3D models can simulate the effects of multi-cellular tissue architecture on the spatial variation in VEGF ligand production and receptor activation; compartmental modeling allows efficient prediction of average interstitial VEGF concentrations and cell-surface VEGF signaling intensities across multiple large tissue volumes, permitting the investigation of whole-body inter-tissue transport (e.g., vascular permeability and lymphatic drainage). The given examples will demonstrate the utility of computational models in aiding both basic science and clinical research on VEGF systems biology. PMID:19897104

  17. Near-infrared spectroscopy for monitoring of tissue oxygenation of exercising skeletal muscle in a chronic compartment syndrome model

    NASA Technical Reports Server (NTRS)

    Breit, G. A.; Gross, J. H.; Watenpaugh, D. E.; Chance, B.; Hargens, A. R.

    1997-01-01

    Variations in the levels of muscle hemoglobin and of myoglobin oxygen saturation can be detected non-invasively with near-infrared spectroscopy. This technique could be applied to the diagnosis of chronic compartment syndrome, in which invasive testing has shown increased intramuscular pressure associated with ischemia and pain during exercise. We simulated chronic compartment syndrome in ten healthy subjects (seven men and three women) by applying external compression, through a wide inflatable cuff, to increase the intramuscular pressure in the anterior compartment of the leg. The tissue oxygenation of the tibialis anterior muscle was measured with near-infrared spectroscopy during gradual inflation of the cuff to a pressure of forty millimeters of mercury (5.33 kilopascals) during fourteen minutes of cyclic isokinetic dorsiflexion and plantar flexion of the ankle. The subjects exercised with and without external compression. The data on tissue oxygenation for each subject then were normalized to a scale of 100 per cent (the baseline value, or the value at rest) to 0 per cent (the physiological minimum, or the level of oxygenation achieved by exercise to exhaustion during arterial occlusion of the lower extremity). With external compression, tissue oxygenation declined at a rate of 1.4 +/- 0.3 per cent per minute (mean and standard error) during exercise. After an initial decrease at the onset, tissue oxygenation did not decline during exercise without compression. The recovery of tissue oxygenation after exercise was twice as slow with compression (2.5 +/- 0.6 minutes) than it was without the use of compression (1.3 +/- 0.2 minutes).

  18. Multi-compartment encapsulation of communicating droplets and droplet networks in hydrogel as a model for artificial cells.

    PubMed

    Bayoumi, Mariam; Bayley, Hagan; Maglia, Giovanni; Sapra, K Tanuj

    2017-04-03

    Constructing a cell mimic is a major challenge posed by synthetic biologists. Efforts to this end have been primarily focused on lipid- and polymer-encapsulated containers, liposomes and polymersomes, respectively. Here, we introduce a multi-compartment, nested system comprising aqueous droplets stabilized in an oil/lipid mixture, all encapsulated in hydrogel. Functional capabilities (electrical and chemical communication) were imparted by protein nanopores spanning the lipid bilayer formed at the interface of the encapsulated aqueous droplets and the encasing hydrogel. Crucially, the compartmentalization enabled the formation of two adjoining lipid bilayers in a controlled manner, a requirement for the realization of a functional protocell or prototissue.

  19. Multi-compartment encapsulation of communicating droplets and droplet networks in hydrogel as a model for artificial cells

    PubMed Central

    Bayoumi, Mariam; Bayley, Hagan; Maglia, Giovanni; Sapra, K. Tanuj

    2017-01-01

    Constructing a cell mimic is a major challenge posed by synthetic biologists. Efforts to this end have been primarily focused on lipid- and polymer-encapsulated containers, liposomes and polymersomes, respectively. Here, we introduce a multi-compartment, nested system comprising aqueous droplets stabilized in an oil/lipid mixture, all encapsulated in hydrogel. Functional capabilities (electrical and chemical communication) were imparted by protein nanopores spanning the lipid bilayer formed at the interface of the encapsulated aqueous droplets and the encasing hydrogel. Crucially, the compartmentalization enabled the formation of two adjoining lipid bilayers in a controlled manner, a requirement for the realization of a functional protocell or prototissue. PMID:28367984

  20. 1D-3D hybrid modeling—from multi-compartment models to full resolution models in space and time

    PubMed Central

    Grein, Stephan; Stepniewski, Martin; Reiter, Sebastian; Knodel, Markus M.; Queisser, Gillian

    2014-01-01

    Investigation of cellular and network dynamics in the brain by means of modeling and simulation has evolved into a highly interdisciplinary field, that uses sophisticated modeling and simulation approaches to understand distinct areas of brain function. Depending on the underlying complexity, these models vary in their level of detail, in order to cope with the attached computational cost. Hence for large network simulations, single neurons are typically reduced to time-dependent signal processors, dismissing the spatial aspect of each cell. For single cell or networks with relatively small numbers of neurons, general purpose simulators allow for space and time-dependent simulations of electrical signal processing, based on the cable equation theory. An emerging field in Computational Neuroscience encompasses a new level of detail by incorporating the full three-dimensional morphology of cells and organelles into three-dimensional, space and time-dependent, simulations. While every approach has its advantages and limitations, such as computational cost, integrated and methods-spanning simulation approaches, depending on the network size could establish new ways to investigate the brain. In this paper we present a hybrid simulation approach, that makes use of reduced 1D-models using e.g., the NEURON simulator—which couples to fully resolved models for simulating cellular and sub-cellular dynamics, including the detailed three-dimensional morphology of neurons and organelles. In order to couple 1D- and 3D-simulations, we present a geometry-, membrane potential- and intracellular concentration mapping framework, with which graph- based morphologies, e.g., in the swc- or hoc-format, are mapped to full surface and volume representations of the neuron and computational data from 1D-simulations can be used as boundary conditions for full 3D simulations and vice versa. Thus, established models and data, based on general purpose 1D-simulators, can be directly coupled to

  1. Metabolic modeling of dynamic brain ¹³C NMR multiplet data: concepts and simulations with a two-compartment neuronal-glial model.

    PubMed

    Shestov, Alexander A; Valette, Julien; Deelchand, Dinesh K; Uğurbil, Kâmil; Henry, Pierre-Gilles

    2012-11-01

    Metabolic modeling of dynamic (13)C labeling curves during infusion of (13)C-labeled substrates allows quantitative measurements of metabolic rates in vivo. However metabolic modeling studies performed in the brain to date have only modeled time courses of total isotopic enrichment at individual carbon positions (positional enrichments), not taking advantage of the additional dynamic (13)C isotopomer information available from fine-structure multiplets in (13)C spectra. Here we introduce a new (13)C metabolic modeling approach using the concept of bonded cumulative isotopomers, or bonded cumomers. The direct relationship between bonded cumomers and (13)C multiplets enables fitting of the dynamic multiplet data. The potential of this new approach is demonstrated using Monte-Carlo simulations with a brain two-compartment neuronal-glial model. The precision of positional and cumomer approaches are compared for two different metabolic models (with and without glutamine dilution) and for different infusion protocols ([1,6-(13)C(2)]glucose, [1,2-(13)C(2)]acetate, and double infusion [1,6-(13)C(2)]glucose + [1,2-(13)C(2)]acetate). In all cases, the bonded cumomer approach gives better precision than the positional approach. In addition, of the three different infusion protocols considered here, the double infusion protocol combined with dynamic bonded cumomer modeling appears the most robust for precise determination of all fluxes in the model. The concepts and simulations introduced in the present study set the foundation for taking full advantage of the available dynamic (13)C multiplet data in metabolic modeling.

  2. Explicit reformulations of the Lambert W-omega function for calculations of the solutions to one-compartment pharmacokinetic models with Michaelis-Menten elimination kinetics.

    PubMed

    Goličnik, Marko

    2011-09-01

    The exact closed-form solutions to the integrated rate equations for one-compartment pharmacokinetic models that obey Michaelis-Menten elimination kinetics were derived recently (Tang and Xiao in J Pharmacokin Pharmacodyn 34:807-827, 2007). These solutions are expressed in terms of the Lambert W(x)-omega function; however, unfortunately, most of the available computer programs are not set up to handle equations that involve the W(x) function. Therefore, in this article, I provide alternative explicit analytical equations expressed in terms of elementary mathematical functions that accurately approximate exact solutions and can be simply calculated using any optional standard software.

  3. Psoas compartment block.

    PubMed

    Brooks, D M

    2000-05-01

    The psoas compartment acts as a conduit for the nerve roots of the lumbar plexus. Originating at approximately the 12th thoracic vertebrae, this potential compartment continues on caudally, bordered posterolaterally by fascia of the quadratus lumborum and iliacus muscles, medially by the fascia of the psoas major muscle, and anteriorly by the transversalis fascia. This natural "gutter" acts as a repository for local anesthetic agents and provides an excellent method of unilateral anterior lower extremity anesthesia. After elicitation of a motor evoked response in the muscles of the anterior thigh, 30 to 40 milliliters of local anesthetic is incrementally injected into the compartment. Spread of the anesthetic to all roots of the plexus occurs in 15 to 20 minutes. Profound sensory and motor blockade can be achieved providing surgical anesthesia as well as long duration postoperative pain relief.

  4. Using multi-compartment ensemble modeling as an investigative tool of spatially distributed biophysical balances: application to hippocampal oriens-lacunosum/moleculare (O-LM) cells.

    PubMed

    Sekulić, Vladislav; Lawrence, J Josh; Skinner, Frances K

    2014-01-01

    Multi-compartmental models of neurons provide insight into the complex, integrative properties of dendrites. Because it is not feasible to experimentally determine the exact density and kinetics of each channel type in every neuronal compartment, an essential goal in developing models is to help characterize these properties. To address biological variability inherent in a given neuronal type, there has been a shift away from using hand-tuned models towards using ensembles or populations of models. In collectively capturing a neuron's output, ensemble modeling approaches uncover important conductance balances that control neuronal dynamics. However, conductances are never entirely known for a given neuron class in terms of its types, densities, kinetics and distributions. Thus, any multi-compartment model will always be incomplete. In this work, our main goal is to use ensemble modeling as an investigative tool of a neuron's biophysical balances, where the cycling between experiment and model is a design criterion from the start. We consider oriens-lacunosum/moleculare (O-LM) interneurons, a prominent interneuron subtype that plays an essential gating role of information flow in hippocampus. O-LM cells express the hyperpolarization-activated current (Ih). Although dendritic Ih could have a major influence on the integrative properties of O-LM cells, the compartmental distribution of Ih on O-LM dendrites is not known. Using a high-performance computing cluster, we generated a database of models that included those with or without dendritic Ih. A range of conductance values for nine different conductance types were used, and different morphologies explored. Models were quantified and ranked based on minimal error compared to a dataset of O-LM cell electrophysiological properties. Co-regulatory balances between conductances were revealed, two of which were dependent on the presence of dendritic Ih. These findings inform future experiments that differentiate between

  5. Using Multi-Compartment Ensemble Modeling As an Investigative Tool of Spatially Distributed Biophysical Balances: Application to Hippocampal Oriens-Lacunosum/Moleculare (O-LM) Cells

    PubMed Central

    Sekulić, Vladislav; Lawrence, J. Josh; Skinner, Frances K.

    2014-01-01

    Multi-compartmental models of neurons provide insight into the complex, integrative properties of dendrites. Because it is not feasible to experimentally determine the exact density and kinetics of each channel type in every neuronal compartment, an essential goal in developing models is to help characterize these properties. To address biological variability inherent in a given neuronal type, there has been a shift away from using hand-tuned models towards using ensembles or populations of models. In collectively capturing a neuron's output, ensemble modeling approaches uncover important conductance balances that control neuronal dynamics. However, conductances are never entirely known for a given neuron class in terms of its types, densities, kinetics and distributions. Thus, any multi-compartment model will always be incomplete. In this work, our main goal is to use ensemble modeling as an investigative tool of a neuron's biophysical balances, where the cycling between experiment and model is a design criterion from the start. We consider oriens-lacunosum/moleculare (O-LM) interneurons, a prominent interneuron subtype that plays an essential gating role of information flow in hippocampus. O-LM cells express the hyperpolarization-activated current (Ih). Although dendritic Ih could have a major influence on the integrative properties of O-LM cells, the compartmental distribution of Ih on O-LM dendrites is not known. Using a high-performance computing cluster, we generated a database of models that included those with or without dendritic Ih. A range of conductance values for nine different conductance types were used, and different morphologies explored. Models were quantified and ranked based on minimal error compared to a dataset of O-LM cell electrophysiological properties. Co-regulatory balances between conductances were revealed, two of which were dependent on the presence of dendritic Ih. These findings inform future experiments that differentiate between

  6. Differentiation of radioligand delivery and binding in the brain: Validation of a two-compartment model for (11C)flumazenil

    SciTech Connect

    Holthoff, V.A.; Koeppe, R.A.; Frey, K.A.; Paradise, A.H.; Kuhl, D.E. )

    1991-09-01

    The authors recently developed a two-compartment, two-parameter tracer kinetic model to estimate the in vivo ligand transport rate (K1) and distribution volume (DV) for the benzodiazepine antagonist (11C)flumazenil (FMZ) as measured by positron emission tomography (PET). The aim of the present study was to validate that this simplified model provides a stable measure of regional benzodiazepine receptor availability even when ligand delivery is altered. Six young normal volunteers underwent two PET studies subsequent to intravenous injections of (11C)FMZ. Each FMZ study was immediately preceded by measurements of CBF following injection of (15O)water. One set of scans (water/FMZ) was acquired under resting conditions and the other set during audiovisual stimulation. Six additional volunteers underwent two FMZ studies under identical resting conditions. Parametric images were analyzed and a comparison of test-retest studies in the stimulation group revealed a significant increase of CBF and K1 of FMZ in the occipital cortex evoked by visual activation, whereas no regional changes were noted for the DV of FMZ. No significant changes were noted for either K1 or DV of FMZ when comparing studies in the rest-rest setting. The results indicate that the use of a simple two-compartment model for the tracer kinetic analysis of (11C)FMZ makes it possible to separate high-affinity binding from altered radio-ligand delivery to the human brain.

  7. The STATFLUX code: a statistical method for calculation of flow and set of parameters, based on the Multiple-Compartment Biokinetical Model

    NASA Astrophysics Data System (ADS)

    Garcia, F.; Mesa, J.; Arruda-Neto, J. D. T.; Helene, O.; Vanin, V.; Milian, F.; Deppman, A.; Rodrigues, T. E.; Rodriguez, O.

    2007-03-01

    The code STATFLUX, implementing a new and simple statistical procedure for the calculation of transfer coefficients in radionuclide transport to animals and plants, is proposed. The method is based on the general multiple-compartment model, which uses a system of linear equations involving geometrical volume considerations. Flow parameters were estimated by employing two different least-squares procedures: Derivative and Gauss-Marquardt methods, with the available experimental data of radionuclide concentrations as the input functions of time. The solution of the inverse problem, which relates a given set of flow parameter with the time evolution of concentration functions, is achieved via a Monte Carlo simulation procedure. Program summaryTitle of program:STATFLUX Catalogue identifier:ADYS_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADYS_v1_0 Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland Licensing provisions: none Computer for which the program is designed and others on which it has been tested:Micro-computer with Intel Pentium III, 3.0 GHz Installation:Laboratory of Linear Accelerator, Department of Experimental Physics, University of São Paulo, Brazil Operating system:Windows 2000 and Windows XP Programming language used:Fortran-77 as implemented in Microsoft Fortran 4.0. NOTE: Microsoft Fortran includes non-standard features which are used in this program. Standard Fortran compilers such as, g77, f77, ifort and NAG95, are not able to compile the code and therefore it has not been possible for the CPC Program Library to test the program. Memory required to execute with typical data:8 Mbytes of RAM memory and 100 MB of Hard disk memory No. of bits in a word:16 No. of lines in distributed program, including test data, etc.:6912 No. of bytes in distributed program, including test data, etc.:229 541 Distribution format:tar.gz Nature of the physical problem:The investigation of transport mechanisms for

  8. Estimation of the parameter covariance matrix for aone-compartment cardiac perfusion model estimated from a dynamic sequencereconstructed using map iterative reconstruction algorithms

    SciTech Connect

    Gullberg, Grant T.; Huesman, Ronald H.; Reutter, Bryan W.; Qi,Jinyi; Ghosh Roy, Dilip N.

    2004-01-01

    In dynamic cardiac SPECT estimates of kinetic parameters ofa one-compartment perfusion model are usually obtained in a two stepprocess: 1) first a MAP iterative algorithm, which properly models thePoisson statistics and the physics of the data acquisition, reconstructsa sequence of dynamic reconstructions, 2) then kinetic parameters areestimated from time activity curves generated from the dynamicreconstructions. This paper provides a method for calculating thecovariance matrix of the kinetic parameters, which are determined usingweighted least squares fitting that incorporates the estimated varianceand covariance of the dynamic reconstructions. For each transaxial slicesets of sequential tomographic projections are reconstructed into asequence of transaxial reconstructions usingfor each reconstruction inthe time sequence an iterative MAP reconstruction to calculate themaximum a priori reconstructed estimate. Time-activity curves for a sumof activity in a blood region inside the left ventricle and a sum in acardiac tissue region are generated. Also, curves for the variance of thetwo estimates of the sum and for the covariance between the two ROIestimates are generated as a function of time at convergence using anexpression obtained from the fixed-point solution of the statisticalerror of the reconstruction. A one-compartment model is fit to the tissueactivity curves assuming a noisy blood input function to give weightedleast squares estimates of blood volume fraction, wash-in and wash-outrate constants specifying the kinetics of 99mTc-teboroxime for theleftventricular myocardium. Numerical methods are used to calculate thesecond derivative of the chi-square criterion to obtain estimates of thecovariance matrix for the weighted least square parameter estimates. Eventhough the method requires one matrix inverse for each time interval oftomographic acquisition, efficient estimates of the tissue kineticparameters in a dynamic cardiac SPECT study can be obtained with

  9. Temporal and spatial characterization of mononuclear phagocytes in circulating, lung alveolar and interstitial compartments in a mouse model of bleomycin-induced pulmonary injury.

    PubMed

    Ji, Wen-Jie; Ma, Yong-Qiang; Zhou, Xin; Zhang, Yi-Dan; Lu, Rui-Yi; Sun, Hai-Ying; Guo, Zhao-Zeng; Zhang, Zhuoli; Li, Yu-Ming; Wei, Lu-Qing

    2014-01-31

    The mononuclear phagocyte system, including circulating monocytes and tissue resident macrophages, plays an important role in acute lung injury and fibrosis. The detailed dynamic changes of mononuclear phagocytes in the circulating, lung alveolar and interstitial compartments in bleomycin-induced pulmonary injury model have not been fully characterized. The present study was designed to address this issue and analyzed their relationships with pulmonary pathological evolution after bleomycin challenge. A total of 100 male C57BL/6 mice were randomly divided to receive bleomycin (2.5mg/kg, n=50) or normal saline (n=50) via oropharyngeal approach, and were sacrificed on days 1, 3, 7, 14 and 21. Circulating monocyte subsets, polarization state of bronchoalveolar lavage fluid (BALF)-derived alveolar macrophages (AMφ) and lung interstitial macrophages (IMφ, derived from enzymatically digested lung tissue) were analyzed by flow cytometry. There was a rapid expansion of circulating Ly6C(hi) monocytes which peaked on day 3, and its magnitude was positively associated with pulmonary inflammatory response. Moreover, an expansion of M2-like AMφ (F4/80+CD11c+CD206+) peaked on day 14, and was positively correlated with the magnitude of lung fibrosis. The polarization state of IMφ remained relatively stable in the early- and mid-stage after bleomycin challenge, expect for an increase of M2-like (F4/80+CD11c-CD206+) IMφ on day 21. These results support the notion that there is a Ly6C(hi)-monocyte-directed pulmonary AMφ alternative activation. Our result provides a dynamic view of mononuclear phagocyte change in three compartments after bleomycin challenge, which is relevant for designing new treatment strategies targeting mononuclear phagocytes in this model.

  10. A Physiologically-Motivated Compartment-Based Model of the Effect of Inhaled Hypertonic Saline on Mucociliary Clearance and Liquid Transport in Cystic Fibrosis

    PubMed Central

    Markovetz, Matthew R.; Corcoran, Timothy E.; Locke, Landon W.; Myerburg, Michael M.; Pilewski, Joseph M.; Parker, Robert S.

    2014-01-01

    Background Cystic Fibrosis (CF) lung disease is characterized by liquid hyperabsorption, airway surface dehydration, and impaired mucociliary clearance (MCC). Herein, we present a compartment-based mathematical model of the airway that extends the resolution of functional imaging data. Methods Using functional imaging data to inform our model, we developed a system of mechanism-motivated ordinary differential equations to describe the mucociliary clearance and absorption of aerosolized radiolabeled particle and small molecules probes from human subjects with and without CF. We also utilized a novel imaging metric in vitro to gauge the fraction of airway epithelial cells that have functional ciliary activity. Results This model, and its incorporated kinetic rate parameters, captures the MCC and liquid dynamics of the hyperabsorptive state in CF airways and the mitigation of that state by hypertonic saline treatment. Conclusions We postulate, based on the model structure and its ability to capture clinical patient data, that patients with CF have regions of airway with diminished MCC function that can be recruited with hypertonic saline treatment. In so doing, this model structure not only makes a case for durable osmotic agents used in lung-region specific treatments, but also may provide a possible clinical endpoint, the fraction of functional ciliated airway. PMID:25383714

  11. Limit cycle stability analysis and adaptive control of a multi-compartment model for a pressure-limited respirator and lung mechanics system

    NASA Astrophysics Data System (ADS)

    Chellaboina, VijaySekhar; Haddad, Wassim M.; Li, Hancao; Bailey, James M.

    2010-05-01

    Acute respiratory failure due to infection, trauma or major surgery is one of the most common problems encountered in intensive care units, and mechanical ventilation is the mainstay of supportive therapy for such patients. In this article, we develop a general mathematical model for the dynamic behaviour of a multi-compartment respiratory system in response to an arbitrary applied inspiratory pressure. Specifically, we use compartmental dynamical system theory and Poincaré maps to model and analyse the dynamics of a pressure-limited respirator and lung mechanics system, and show that the periodic orbit generated by this system is globally asymptotically stable. Furthermore, we show that the individual compartmental volumes, and hence the total lung volume, converge to steady-state end-inspiratory and end-expiratory values. Finally, we develop a model reference direct adaptive controller framework for the multi-compartmental model of a pressure-limited respirator and lung mechanics system where the plant and reference model involve switching and time-varying dynamics. We then apply the proposed adaptive feedback controller framework to stabilise a given limit cycle corresponding to a clinically plausible respiratory pattern.

  12. Neonatal compartment syndrome

    PubMed Central

    Martin, B; Treharne, L

    2016-01-01

    A term neonate was born with a grossly swollen and discoloured left hand and forearm. He was transferred from the local hospital to the plastic surgical unit, where a diagnosis of compartment syndrome was made and he underwent emergency forearm fasciotomies at six hours of age. Following serial debridements of necrotic tissue, he underwent split-thickness skin grafting of the resultant defects of his forearm, hand and digits. At the clinic follow-up appointment two months after the procedure, he was found to have developed severe flexion contractures despite regular outpatient hand therapy and splintage. He has had further reconstruction with contracture release, use of artificial dermal matrix, and K-wire fixation of the thumb and wrist. Despite this, the long term outcome is likely to be an arm with poor function. The key learning point from this case is that despite prompt transfer, diagnosis and appropriate surgical management, the outcome for neonatal compartment syndrome may still be poor. PMID:27138850

  13. Using a Semi-Automated Strategy to Develop Multi-Compartment Models That Predict Biophysical Properties of Interneuron-Specific 3 (IS3) Cells in Hippocampus

    PubMed Central

    Camiré, Olivier

    2016-01-01

    Abstract Determining how intrinsic cellular properties govern and modulate neuronal input–output processing is a critical endeavor for understanding microcircuit functions in the brain. However, lack of cellular specifics and nonlinear interactions prevent experiments alone from achieving this. Building and using cellular models is essential in these efforts. We focus on uncovering the intrinsic properties of mus musculus hippocampal type 3 interneuron-specific (IS3) cells, a cell type that makes GABAergic synapses onto specific interneuron types, but not pyramidal cells. While IS3 cell morphology and synaptic output have been examined, their voltage-gated ion channel profile and distribution remain unknown. We combined whole-cell patch-clamp recordings and two-photon dendritic calcium imaging to examine IS3 cell membrane and dendritic properties. Using these data as a target reference, we developed a semi-automated strategy to obtain multi-compartment models for a cell type with unknown intrinsic properties. Our approach is based on generating populations of models to capture determined features of the experimental data, each of which possesses unique combinations of channel types and conductance values. From these populations, we chose models that most closely resembled the experimental data. We used these models to examine the impact of specific ion channel combinations on spike generation. Our models predict that fast delayed rectifier currents should be present in soma and proximal dendrites, and this is confirmed using immunohistochemistry. Further, without A-type potassium currents in the dendrites, spike generation is facilitated at more distal synaptic input locations. Our models will help to determine the functional role of IS3 cells in hippocampal microcircuits. PMID:27679813

  14. Using a Semi-Automated Strategy to Develop Multi-Compartment Models That Predict Biophysical Properties of Interneuron-Specific 3 (IS3) Cells in Hippocampus.

    PubMed

    Guet-McCreight, Alexandre; Camiré, Olivier; Topolnik, Lisa; Skinner, Frances K

    2016-01-01

    Determining how intrinsic cellular properties govern and modulate neuronal input-output processing is a critical endeavor for understanding microcircuit functions in the brain. However, lack of cellular specifics and nonlinear interactions prevent experiments alone from achieving this. Building and using cellular models is essential in these efforts. We focus on uncovering the intrinsic properties of mus musculus hippocampal type 3 interneuron-specific (IS3) cells, a cell type that makes GABAergic synapses onto specific interneuron types, but not pyramidal cells. While IS3 cell morphology and synaptic output have been examined, their voltage-gated ion channel profile and distribution remain unknown. We combined whole-cell patch-clamp recordings and two-photon dendritic calcium imaging to examine IS3 cell membrane and dendritic properties. Using these data as a target reference, we developed a semi-automated strategy to obtain multi-compartment models for a cell type with unknown intrinsic properties. Our approach is based on generating populations of models to capture determined features of the experimental data, each of which possesses unique combinations of channel types and conductance values. From these populations, we chose models that most closely resembled the experimental data. We used these models to examine the impact of specific ion channel combinations on spike generation. Our models predict that fast delayed rectifier currents should be present in soma and proximal dendrites, and this is confirmed using immunohistochemistry. Further, without A-type potassium currents in the dendrites, spike generation is facilitated at more distal synaptic input locations. Our models will help to determine the functional role of IS3 cells in hippocampal microcircuits.

  15. Three‐dimensional immersive virtual reality for studying cellular compartments in 3D models from EM preparations of neural tissues

    PubMed Central

    Baghabra, Jumana; Boges, Daniya J.; Holst, Glendon R.; Kreshuk, Anna; Hamprecht, Fred A.; Srinivasan, Madhusudhanan; Lehväslaiho, Heikki

    2016-01-01

    ABSTRACT Advances in the application of electron microscopy (EM) to serial imaging are opening doors to new ways of analyzing cellular structure. New and improved algorithms and workflows for manual and semiautomated segmentation allow us to observe the spatial arrangement of the smallest cellular features with unprecedented detail in full three‐dimensions. From larger samples, higher complexity models can be generated; however, they pose new challenges to data management and analysis. Here we review some currently available solutions and present our approach in detail. We use the fully immersive virtual reality (VR) environment CAVE (cave automatic virtual environment), a room in which we are able to project a cellular reconstruction and visualize in 3D, to step into a world created with Blender, a free, fully customizable 3D modeling software with NeuroMorph plug‐ins for visualization and analysis of EM preparations of brain tissue. Our workflow allows for full and fast reconstructions of volumes of brain neuropil using ilastik, a software tool for semiautomated segmentation of EM stacks. With this visualization environment, we can walk into the model containing neuronal and astrocytic processes to study the spatial distribution of glycogen granules, a major energy source that is selectively stored in astrocytes. The use of CAVE was key to the observation of a nonrandom distribution of glycogen, and led us to develop tools to quantitatively analyze glycogen clustering and proximity to other subcellular features. J. Comp. Neurol. 524:23–38, 2016. © 2015 Wiley Periodicals, Inc. PMID:26179415

  16. Compartment Syndrome of the Hand.

    PubMed

    Oak, Nikhil R; Abrams, Reid A

    2016-07-01

    Hand compartment syndrome has many etiologies; untreated, it has dire functional consequences. Intracompartmental pressure exceeding capillary filling pressure causes decreased tissue perfusion resulting in progressive ischemic death of compartment contents. Clinical findings can evolve. Serial physical examinations are recommended and, if equivocal, interstitial pressure monitoring is indicated. Definitive management is emergent fasciotomies with incisions designed to decompress the involved hand compartments, which could include the thenar, hypothenar, and interosseous compartments, and the carpal tunnel. Careful wound care, edema management, splinting, and hand therapy are critical. Therapy should start early postoperatively, possibly before wound closure.

  17. Integrated observation and modelling of runoff and sediments across different compartments of semi-arid catchments and channel networks

    NASA Astrophysics Data System (ADS)

    Bronstert, Axel; Ramon, Batalla; Araújo José C., De; da Costa Alexandre, Cunha; Till, Francke; Andreas, Güntner; Jose, Lopez-Tarazon; George, Mamede; Müller Eva, N.

    2010-05-01

    About one-third of the global population currently lives in countries which experience conditions of water stress. Such regions, often located within dryland ecosystems, are exposed to the hazard that the available freshwater resources fail to meet the water demand in domestic, agricultural and industrial sectors. Water availability often relies on the retention of river runoff in artificial lakes and reservoirs. However, the water storage in reservoirs is often adversely affected by sedimentation as a result of soil erosion. Erosion of the land surface due to natural or anthropogenic reasons and deposition of the eroded material in reservoirs threatens the reliability of reservoirs as a source of water supply. To sustain future water supply, a quantification of the sediment export from large dryland catchments becomes indispensable. A comprehensive modelling framework for water and sediment transport at the meso-scale, with a particular focus on dryland regions, has been developed from a German, Catalonian and Brazilian team during the last decade. It includes novel components for erosion from erosion-prone hillslopes, sediment transfer, retention and re-mobilization through the river system and sediment distribution, trapping and transfer through a reservoir. The parameterisation for pilot catchments is based on field monitoring campaigns of water and sediment fluxes, the analysis of land-use patterns, and the identification of the sediment hot spots through remotely sensed data. We present results of erosion-prone landscape units, the role of sediment transport in the river system, and the sedimentation processes in reservoirs. The modelling studies demonstrate the wide range of environmental problems where the model may be employed to develop sustainable management strategies for land and water resources. Evaluation of scenarios (land use, climate change) combined with an integrated assessment of options in reservoir management opens the opportunity to address

  18. Environment-responsive fluorescent nucleoside analogue probe for studying oligonucleotide dynamics in a model cell-like compartment.

    PubMed

    Pawar, Maroti G; Srivatsan, Seergazhi G

    2013-11-21

    The majority of fluorescent nucleoside analogue probes that have been used in the in vitro study of nucleic acids are not suitable for cell-based biophysical assays because they exhibit excitation maxima in the UV region and low quantum yields within oligonucleotides. Therefore, we propose that the photophysical characterization of oligonucleotides labeled with a fluorescent nucleoside analogue in reverse micelles (RM), which are good biological membrane models and UV-transparent, could provide an alternative approach to studying the properties of nucleic acids in a cell-like confined environment. In this context, we describe the photophysical properties of an environment-sensitive fluorescent uridine analogue (1), based on the 5-(benzo[b]thiophen-2-yl)pyrimidine core, in micelles and RM. The emissive nucleoside, which is polarity- and viscosity-sensitive, reports the environment of the surfactant assemblies via changes in its fluorescence properties. The nucleoside analogue, incorporated into an RNA oligonucleotide and hybridized to its complementary DNA and RNA oligonucleotides, exhibits a significantly higher fluorescence intensity, lifetime, and anisotropy in RM than in aqueous buffer, which is consistent with the environment of RM. Collectively, our results demonstrate that nucleoside 1 could be utilized as a fluorescent label to study the function of nucleic acids in a model cellular milieu.

  19. Determination of protein-bound palmitate turnover rates using a three-compartment model that formally incorporates [3H]palmitate recycling.

    PubMed

    Qanbar, Riad; Bouvier, Michel

    2004-09-28

    The observation that the palmitoylation state of certain proteins can be biologically modulated led to the proposal that it could, much like phosphorylation, be an important dynamic regulator of protein function. However, based on single-phase exponential decay analysis of data from [(3)H]palmitate pulse/chase experiments, the measured protein-bound palmitate turnover rates were often found to be too slow to account for rapid physiological responses. This paper reports that exponential decay does not adequately describe the results of such experiments because it fails to account for the recycling of [(3)H]palmitate from cellular lipids to palmitoyl CoA. Taking this recycling into account, a three-compartment model was used to deduce the time-dependent changes of cellular [(3)H]palmitoyl CoA and to infer the time course for the incorporation of [(3)H]palmitate into proteins. The validity of the inferences made by the model was checked against data obtained by metabolic labeling of endogenous HEK293 cell proteins. In addition, the model could account for reported anomalies, discrepancies, and apparently paradoxical observations obtained by traditional analysis of data from pulse/chase experiments. Including the recycling of cellular palmitate in the formal description of the system offers a new tool for quantitative assessment of protein-bound palmitate turnover rates. Through the re-evaluation of these rates, the model provides a means for the reassessment of the potential physiological implications of dynamic palmitoylation. The model may also be generally applicable to other areas of research where recycling of tracer is a concern.

  20. Radio-Photothermal Therapy Mediated by a Single Compartment Nanoplatform Depletes Tumor Initiating Cells and Reduces Lung Metastasis in Orthotopic 4T1 Breast Tumor Model

    PubMed Central

    Zhou, Min; Zhao, Jun; Tian, Mei; Song, Shaoli; Zhang, Rui; Gupta, Sanjay; Tan, Dongfeng; Shen, Haifa; Ferrari, Mauro; Li, Chun

    2016-01-01

    Tumor Initiating Cells (TICs) are resistant to radiotherapy and chemotherapy, and are believed to be responsible for tumor recurrence and metastasis. Combination therapies can overcome the limitation of conventional cancer treatments, and has demonstrated promising application in clinic. Here, we show that dual modality radiotherapy (RT) and photothermal therapy (PTT) mediated by a single compartment nanosystem copper-64-labeled copper sulfide nanoparticles ([64Cu]CuS NPs) could suppress breast tumor metastasis through eradication of TICs. Positron electron tomography (PET) imaging and biodistribution studies showed that more than 90% of [64Cu]CuS NPs was retained in subcutaneously grown BT474 breast tumor 24 h after intratumoral (i.t.) injection, indicating the NPs is suitable for the combination therapy. Combined RT/PTT therapy resulted in significant tumor growth delay in subcutaneous BT474 breast cancer model. Moreover, RT/PTT treatment significantly prolonged the survival of mice bearing orthotopic 4T1 breast tumors compared to no treatment, RT alone, or PTT alone. The RT/PTT combination therapy significantly reduced the number of tumor nodules in the lung and the formation of tumor mammospheres from treated 4T1 tumors. No obvious side effects of the CuS NPs were noted in the treated mice in a pilot toxicity study. Taken together, our data support the feasibility of a therapeutic approach for suppression of tumor metastasis through localized RT/PTT therapy. PMID:26376843

  1. COMPARTMENTED REACTOR FUEL ELEMENT

    DOEpatents

    Cain, F.M. Jr.

    1962-09-11

    A method of making a nuclear reactor fuel element of the elongated red type is given wherein the fissionable fuel material is enclosed within a tubular metal cladding. The method comprises coating the metal cladding tube on its inside wall with a brazing alloy, inserting groups of cylindrical pellets of fissionable fuel material into the tube with spacing members between adjacent groups of pellets, sealing the ends of the tubes to leave a void space therewithin, heating the tube and its contents to an elevated temperature to melt the brazing alloy and to expand the pellets to their maximum dimensions under predetermined operating conditions thereby automatically positioning the spacing members along the tube, and finally cooling the tube to room temperature whereby the spacing disks become permanently fixed at their edges in the brazing alloy and define a hermetically sealed compartment for each fl group of fuel pellets. Upon cooling, the pellets contract thus leaving a space to accommodate thermal expansion of the pellets when in use in a reactor. The spacing members also provide lateral support for the tubular cladding to prevent collapse thereof when subjected to a reactor environment. (AEC)

  2. Radio-photothermal therapy mediated by a single compartment nanoplatform depletes tumor initiating cells and reduces lung metastasis in the orthotopic 4T1 breast tumor model

    NASA Astrophysics Data System (ADS)

    Zhou, Min; Zhao, Jun; Tian, Mei; Song, Shaoli; Zhang, Rui; Gupta, Sanjay; Tan, Dongfeng; Shen, Haifa; Ferrari, Mauro; Li, Chun

    2015-11-01

    Tumor Initiating Cells (TICs) are resistant to radiotherapy and chemotherapy, and are believed to be responsible for tumor recurrence and metastasis. Combination therapies can overcome the limitation of conventional cancer treatments, and have demonstrated promising application in the clinic. Here, we show that dual modality radiotherapy (RT) and photothermal therapy (PTT) mediated by a single compartment nanosystem copper-64-labeled copper sulfide nanoparticles ([64Cu]CuS NPs) could suppress breast tumor metastasis through eradication of TICs. Positron electron tomography (PET) imaging and biodistribution studies showed that more than 90% of [64Cu]CuS NPs was retained in subcutaneously grown BT474 breast tumor 24 h after intratumoral (i.t.) injection, indicating the NPs are suitable for the combination therapy. Combined RT/PTT therapy resulted in significant tumor growth delay in the subcutaneous BT474 breast cancer model. Moreover, RT/PTT treatment significantly prolonged the survival of mice bearing orthotopic 4T1 breast tumors compared to no treatment, RT alone, or PTT alone. The RT/PTT combination therapy significantly reduced the number of tumor nodules in the lung and the formation of tumor mammospheres from treated 4T1 tumors. No obvious side effects of the CuS NPs were noted in the treated mice in a pilot toxicity study. Taken together, our data support the feasibility of a therapeutic approach for the suppression of tumor metastasis through localized RT/PTT therapy.Tumor Initiating Cells (TICs) are resistant to radiotherapy and chemotherapy, and are believed to be responsible for tumor recurrence and metastasis. Combination therapies can overcome the limitation of conventional cancer treatments, and have demonstrated promising application in the clinic. Here, we show that dual modality radiotherapy (RT) and photothermal therapy (PTT) mediated by a single compartment nanosystem copper-64-labeled copper sulfide nanoparticles ([64Cu]CuS NPs) could suppress

  3. Ceftaroline plus avibactam demonstrates bactericidal activity against pathogenic anaerobic bacteria in a one-compartment in vitro pharmacokinetic/pharmacodynamic model.

    PubMed

    Werth, Brian J; Rybak, Michael J

    2014-01-01

    Anaerobic pathogens are often associated with polymicrobial infections, such as diabetic foot infections. Patients with these infections are often treated with broad-spectrum, multidrug therapies targeting resistant Gram-positive bacteria, such as methicillin-resistant Staphylococcus aureus, as well as Gram-negative bacteria and anaerobes. The broad-spectrum, non-beta-lactam, beta-lactamase inhibitor avibactam has been combined with ceftaroline and may provide a single-product alternative for complicated polymicrobial infections. We compared the activity of ceftaroline-avibactam (CPA) to that of ertapenem (ERT) against common anaerobic pathogens in an in vitro pharmacokinetic/pharmacodynamic (PK/PD) model. Simulations of doses of ceftaroline-fosamil at 600 mg every 8 h (q8h) (maximum free drug concentration [fCmax], 17.04 mg/liter, and half-life [t1/2], 2.66 h) plus avibactam at 600 mg q8h (fCmax, 11.72 mg/liter, and t1/2, 1.8 h) and of ertapenem at 1 g q24h (fCmax, 13 mg/liter, and t1/2, 4 h) were evaluated against two strains of Bacteroides fragilis, one strain of Prevotella bivia, and one strain of Finegoldia magna in an anaerobic one-compartment in vitro PK/PD model over 72 h with a starting inoculum of ∼8 log10 CFU/ml. Bactericidal activity was defined as a reduction of ≥3 log10 CFU/ml from the starting inoculum. Both CPA and ERT were bactericidal against all four strains. CPA demonstrated improved activity against Bacteroides strains compared to that of ERT but had similar activity against Finegoldia magna and P. bivia, although modest regrowth was observed with CPA against P. bivia. No resistance emerged from any of the models. The pharmacokinetics achieved were 92 to 105% of the targets. CPA has potent in vitro activity against common anaerobic pathogens at clinically relevant drug exposures and may be a suitable single product for the management of complicated polymicrobial infections.

  4. Stochastic Turing patterns: analysis of compartment-based approaches.

    PubMed

    Cao, Yang; Erban, Radek

    2014-12-01

    Turing patterns can be observed in reaction-diffusion systems where chemical species have different diffusion constants. In recent years, several studies investigated the effects of noise on Turing patterns and showed that the parameter regimes, for which stochastic Turing patterns are observed, can be larger than the parameter regimes predicted by deterministic models, which are written in terms of partial differential equations (PDEs) for species concentrations. A common stochastic reaction-diffusion approach is written in terms of compartment-based (lattice-based) models, where the domain of interest is divided into artificial compartments and the number of molecules in each compartment is simulated. In this paper, the dependence of stochastic Turing patterns on the compartment size is investigated. It has previously been shown (for relatively simpler systems) that a modeler should not choose compartment sizes which are too small or too large, and that the optimal compartment size depends on the diffusion constant. Taking these results into account, we propose and study a compartment-based model of Turing patterns where each chemical species is described using a different set of compartments. It is shown that the parameter regions where spatial patterns form are different from the regions obtained by classical deterministic PDE-based models, but they are also different from the results obtained for the stochastic reaction-diffusion models which use a single set of compartments for all chemical species. In particular, it is argued that some previously reported results on the effect of noise on Turing patterns in biological systems need to be reinterpreted.

  5. Compartment in vertical flow reactor for ferruginous mine water

    NASA Astrophysics Data System (ADS)

    Hur, Won; Cheong, Young-Wook; Yim, Gil-Jae; Ji, Sang-Woo; Hong, Ji-Hye

    2014-05-01

    Mine effluents contain varying concentrations of ferrous ion along with other metal ions. Fe(II) that quickly oxidizes to form precipitates in the presence of oxygen under net alkaline or neutral conditions. Thus, passive treatment methods are designed for the mine water to reside in an open containment area so as to allow simultaneous oxidation and precipitation of Fe(II), such as in a lagoon or an oxidation pond. A vertical flow reactor (VFR) was also suggested to remediate ferruginous mine drainage passing down through an accreting bed of ochre. However, VFR has a limited operation time until the system begins to overflow. It was also demonstrated that two-compartment VFR has a longer operation time than single compartment VFR of same size. In this study, a mathematical model was developed as a part of efforts to explore the operation of VFR, showing dynamic changes in head differences, ochre depth and Fe(II)/Fe(III) concentration in the effluent flow. The analysis shows that Fe(II) oxidation and ochre formation should be balanced with permeability of ochre bed to maximize VFR operation time and minimize residual Fe(II) in the effluent. The model demonstrates that two compartment VFR can have a longer operation time than a single-compartment VFR and that an optimum compartment ratio exists that maximize VFR operation time. Accelerated Fe(II) oxidation significantly affects the optimum ratio of compartment area and reduced residual Fe(II) in the effluent. VFR operation time can be significantly prolonged by increasing the rate of ochre formation not by accelerated Fe(II) oxidation. Taken together, ochre forms largely in the first compartment while overflowed mine water with reduced iron contents is efficiently filtered in the second compartment. These results provide us a better understanding of VFR operation and optimum design criteria for maximum operation time in a two-compartment VFR. Rapid ochre accretion in the first compartment maintains constant hydraulic

  6. Dual-Compartment Inflatable Suitlock

    NASA Technical Reports Server (NTRS)

    Kennedy, Kriss J.; Guirgis, Peggy L.; Boyle, Robert M.

    2013-01-01

    There is a need for an improvement over current NASA Extravehicular Activity (EVA) technology. The technology must allow the capacity for quicker, more efficient egress/ingress, allow for shirtsleeve suit maintenance, be compact in transport, and be applicable to environments ranging from planetary surface (partial-g) to orbital or deep space zero-g environments. The technology must also be resistant to dust and other foreign contaminants that may be present on or around a planetary surface. The technology should be portable, and be capable of docking with a variety of habitats, ports, stations, vehicles, and other pressurized modules. The Dual-Compartment Inflatable Suitlock (DCIS) consists of three hard inline bulkheads, separating two cylindrical membrane-walled compartments. The Inner Bulkhead can be fitted with a variety of hatch types, docking flanges, and mating hardware, such as the Common Berthing Mechanism (CBM), for the purpose of mating with vehicles, habitats, and other pressurized modules. The Inner Bulkhead and Center Bulkhead function as the end walls of the Inner Compartment, which during operations, would stay pressurized, either matching the pressure of the habitat or acting as a lower-pressure transitional volume. The Inner Compartment contains donning/doffing fixtures and inner suit-port hatches. The Center Bulkhead has two integrated suit-ports along with a maintenance hatch. The Center Bulkhead and Outer Bulkhead function as the end walls of the Outer Compartment, which stays at vacuum during normal operations. This allows the crewmember to quickly don a suit, and egress the suitlock without waiting for the Outer Compartment to depressurize. The Outer Compartment can be pressurized infrequently for both nominal and off-nominal suit maintenance tasks, allowing shirtsleeve inspections and maintenance/repair of the environmental suits. The Outer Bulkhead has a pressure-assisted hatch door that stays open and stowed during EVA operations, but can

  7. Dual-Compartment Inflatable Suitlock

    NASA Technical Reports Server (NTRS)

    Howe, Scott; Kennedy, Kriss J.; Guirgis, Peggy L.

    2012-01-01

    A paper discusses a dual-compartment inflatable suitlock (DCIS) for Extra - vehicular Activity (EVA) that will allow for dust control, suit maintenance, and efficient EVA egress/ingress. The expandable (inflatable technologies) aspect of the design will allow the unit to stow in a compact package for transport. The DCIS consists of three hard, in line bulkheads, separating two cylindrical membrane-walled compartments. The inner bulkhead can be fitted with a variety of hatch types, docking flanges, and mating hardware, such as the common berthing mechanism (CBM), for the purpose of mating with vehicles, habitats, and other pressurized modules. The inner bulkhead and center bulkhead function as the end walls of the inner compartment, which, during operations, would stay pressurized, either matching the pressure of the habitat or acting as a lower-pressure transitional volume. The suited crewmember can quickly don a suit, and egress the suitlock without waiting for the compartment to depressurize. The outer compartment can be pressurized infrequently, when a long dwell time is expected prior to the next EVA, or during off-nominal suit maintenance tasks, allowing shirtsleeve inspections and maintenance of the space suits. The outer bulkhead has a pressure-assisted hatch door that stays open and stowed routinely, but can be closed for suit maintenance and pressurization as needed.

  8. SU-E-QI-03: Compartment Modeling of Dynamic Brain PET - The Effect of Scatter and Random Corrections On Parameter Errors

    SciTech Connect

    Häggström, I; Karlsson, M; Larsson, A; Schmidtlein, C

    2014-06-15

    Purpose: To investigate the effects of corrections for random and scattered coincidences on kinetic parameters in brain tumors, by using ten Monte Carlo (MC) simulated dynamic FLT-PET brain scans. Methods: The GATE MC software was used to simulate ten repetitions of a 1 hour dynamic FLT-PET scan of a voxelized head phantom. The phantom comprised six normal head tissues, plus inserted regions for blood and tumor tissue. Different time-activity-curves (TACs) for all eight tissue types were used in the simulation and were generated in Matlab using a 2-tissue model with preset parameter values (K1,k2,k3,k4,Va,Ki). The PET data was reconstructed into 28 frames by both ordered-subset expectation maximization (OSEM) and 3D filtered back-projection (3DFBP). Five image sets were reconstructed, all with normalization and different additional corrections C (A=attenuation, R=random, S=scatter): Trues (AC), trues+randoms (ARC), trues+scatters (ASC), total counts (ARSC) and total counts (AC). Corrections for randoms and scatters were based on real random and scatter sinograms that were back-projected, blurred and then forward projected and scaled to match the real counts. Weighted non-linearleast- squares fitting of TACs from the blood and tumor regions was used to obtain parameter estimates. Results: The bias was not significantly different for trues (AC), trues+randoms (ARC), trues+scatters (ASC) and total counts (ARSC) for either 3DFBP or OSEM (p<0.05). Total counts with only AC stood out however, with an up to 160% larger bias. In general, there was no difference in bias found between 3DFBP and OSEM, except in parameter Va and Ki. Conclusion: According to our results, the methodology of correcting the PET data for randoms and scatters performed well for the dynamic images where frames have much lower counts compared to static images. Generally, no bias was introduced by the corrections and their importance was emphasized since omitting them increased bias extensively.

  9. Measuring Compartment Size and Gas Solubility in Marine Mammals

    DTIC Science & Technology

    2015-09-30

    phocids (Fig. 1). Fig. 1: Relative weight of integument (blubber), bones, muscle, internal organs, connective tissue , and the soft tissue of the...status of animals of the same species and similar age. Fig.2: Mean relative body weight of integument, bones, muscle, organs, connective tissue ...a five-compartment model arranging the tissues in the following compartments [10-12]: blood, brain, fat, muscle (muscle, skin, bone, connective

  10. The impact of pH inhomogeneities on CHO cell physiology and fed-batch process performance - two-compartment scale-down modelling and intracellular pH excursion.

    PubMed

    Brunner, Matthias; Braun, Philipp; Doppler, Philipp; Posch, Christoph; Behrens, Dirk; Herwig, Christoph; Fricke, Jens

    2017-01-12

    Due to high mixing times and base addition from top of the vessel, pH inhomogeneities are most likely to occur during large-scale mammalian processes. The goal of this study was to set-up a scale-down model of a 10-12 m(3) stirred tank bioreactor and to investigate the effect of pH perturbations on CHO cell physiology and process performance. Short-term changes in extracellular pH are hypothesized to affect intracellular pH and thus cell physiology. Therefore, batch fermentations, including pH shifts to 9.0 and 7.8, in regular one-compartment systems are conducted. The short-term adaption of the cells intracellular pH are showed an immediate increase due to elevated extracellular pH. With this basis of fundamental knowledge, a two-compartment system is established which is capable of simulating defined pH inhomogeneities. In contrast to state-of-the-art literature, the scale-down model is included parameters (e.g. volume of the inhomogeneous zone) as they might occur during large-scale processes. pH inhomogeneity studies in the two-compartment system are performed with simulation of temporary pH zones of pH 9.0. The specific growth rate especially during the exponential growth phase is strongly affected resulting in a decreased maximum viable cell density and final product titer. The gathered results indicate that even short-term exposure of cells to elevated pH values during large-scale processes can affect cell physiology and overall process performance. In particular, it could be shown for the first time that pH perturbations, which might occur during the early process phase, have to be considered in scale-down models of mammalian processes.

  11. Mathematical model for the contribution of individual organs to non-zero y-intercepts in single and multi-compartment linear models of whole-body energy expenditure.

    PubMed

    Kaiyala, Karl J

    2014-01-01

    Mathematical models for the dependence of energy expenditure (EE) on body mass and composition are essential tools in metabolic phenotyping. EE scales over broad ranges of body mass as a non-linear allometric function. When considered within restricted ranges of body mass, however, allometric EE curves exhibit 'local linearity.' Indeed, modern EE analysis makes extensive use of linear models. Such models typically involve one or two body mass compartments (e.g., fat free mass and fat mass). Importantly, linear EE models typically involve a non-zero (usually positive) y-intercept term of uncertain origin, a recurring theme in discussions of EE analysis and a source of confounding in traditional ratio-based EE normalization. Emerging linear model approaches quantify whole-body resting EE (REE) in terms of individual organ masses (e.g., liver, kidneys, heart, brain). Proponents of individual organ REE modeling hypothesize that multi-organ linear models may eliminate non-zero y-intercepts. This could have advantages in adjusting REE for body mass and composition. Studies reveal that individual organ REE is an allometric function of total body mass. I exploit first-order Taylor linearization of individual organ REEs to model the manner in which individual organs contribute to whole-body REE and to the non-zero y-intercept in linear REE models. The model predicts that REE analysis at the individual organ-tissue level will not eliminate intercept terms. I demonstrate that the parameters of a linear EE equation can be transformed into the parameters of the underlying 'latent' allometric equation. This permits estimates of the allometric scaling of EE in a diverse variety of physiological states that are not represented in the allometric EE literature but are well represented by published linear EE analyses.

  12. Method and apparatus to assess compartment syndrome

    NASA Technical Reports Server (NTRS)

    Ueno, Toshiaki (Inventor); Hargens, Alan R. (Inventor); Yost, William T. (Inventor)

    2008-01-01

    A method and apparatus for measuring pressure buildup in a body compartment that encases muscular tissue. The method includes assessing the body compartment configuration and identifying the effect of pulsatile components on at least one compartment dimension. This process is used in preventing tissue necrosis, and in decisions of whether to perform surgery on the body compartment for prevention of Compartment Syndrome. An apparatus is used for measuring excess pressure in the body compartment having components for imparting ultrasonic waves such as a transducer, placing the transducer to impart the ultrasonic waves, capturing the reflected imparted ultrasonic waves, and converting them to electrical signals, a pulsed phase-locked loop device for assessing a body compartment configuration and producing an output signal, and means for mathematically manipulating the output signal to thereby categorize pressure build-up in the body compartment from the mathematical manipulations.

  13. Orbiter Crew Compartment Integration-Stowage

    NASA Technical Reports Server (NTRS)

    Morgan, L. Gary

    2007-01-01

    This viewgraph presentation describes the Orbiter Crew Compartment Integration (CCI) stowage. The evolution of orbiter crew compartment stowage volume is also described, along with photographs presented of the on-orbit volume stowage capacity.

  14. 36 CFR 1192.127 - Sleeping compartments.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Intercity Rail Cars and Systems § 1192.127 Sleeping compartments. (a) Sleeping compartments required to be... controls, call buttons, electrical outlets, etc.) shall be mounted no more than 48 inches, and no less...

  15. 36 CFR 1192.127 - Sleeping compartments.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Intercity Rail Cars and Systems § 1192.127 Sleeping compartments. (a) Sleeping compartments required to be... controls, call buttons, electrical outlets, etc.) shall be mounted no more than 48 inches, and no less...

  16. 36 CFR 1192.127 - Sleeping compartments.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 3 2011-07-01 2011-07-01 false Sleeping compartments. 1192.127 Section 1192.127 Parks, Forests, and Public Property ARCHITECTURAL AND TRANSPORTATION BARRIERS... Intercity Rail Cars and Systems § 1192.127 Sleeping compartments. (a) Sleeping compartments required to...

  17. 49 CFR 38.127 - Sleeping compartments.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Sleeping compartments. 38.127 Section 38.127... SPECIFICATIONS FOR TRANSPORTATION VEHICLES Intercity Rail Cars and Systems § 38.127 Sleeping compartments. (a) Sleeping compartments required to be accessible shall be designed so as to allow a person using...

  18. 49 CFR 38.127 - Sleeping compartments.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 1 2011-10-01 2011-10-01 false Sleeping compartments. 38.127 Section 38.127... SPECIFICATIONS FOR TRANSPORTATION VEHICLES Intercity Rail Cars and Systems § 38.127 Sleeping compartments. (a) Sleeping compartments required to be accessible shall be designed so as to allow a person using...

  19. 36 CFR 1192.127 - Sleeping compartments.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Sleeping compartments. 1192.127 Section 1192.127 Parks, Forests, and Public Property ARCHITECTURAL AND TRANSPORTATION BARRIERS... Intercity Rail Cars and Systems § 1192.127 Sleeping compartments. (a) Sleeping compartments required to...

  20. 49 CFR 38.127 - Sleeping compartments.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 1 2014-10-01 2014-10-01 false Sleeping compartments. 38.127 Section 38.127... SPECIFICATIONS FOR TRANSPORTATION VEHICLES Intercity Rail Cars and Systems § 38.127 Sleeping compartments. (a) Sleeping compartments required to be accessible shall be designed so as to allow a person using...

  1. 36 CFR 1192.127 - Sleeping compartments.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 3 2013-07-01 2012-07-01 true Sleeping compartments. 1192.127 Section 1192.127 Parks, Forests, and Public Property ARCHITECTURAL AND TRANSPORTATION BARRIERS... Intercity Rail Cars and Systems § 1192.127 Sleeping compartments. (a) Sleeping compartments required to...

  2. 49 CFR 38.127 - Sleeping compartments.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 1 2012-10-01 2012-10-01 false Sleeping compartments. 38.127 Section 38.127... SPECIFICATIONS FOR TRANSPORTATION VEHICLES Intercity Rail Cars and Systems § 38.127 Sleeping compartments. (a) Sleeping compartments required to be accessible shall be designed so as to allow a person using...

  3. Prenatal exposure to radiofrequencies: effects of WiFi signals on thymocyte development and peripheral T cell compartment in an animal model.

    PubMed

    Laudisi, Federica; Sambucci, Manolo; Nasta, Francesca; Pinto, Rosanna; Lodato, Rossella; Altavista, Pierluigi; Lovisolo, Giorgio Alfonso; Marino, Carmela; Pioli, Claudio

    2012-12-01

    Wireless local area networks are an increasing alternative to wired data networks in workplaces, homes, and public areas. Concerns about possible health effects of this type of signal, especially when exposure occurs early in life, have been raised. We examined the effects of prenatal (in utero) exposure to wireless fidelity (WiFi) signal-associated electromagnetic fields (2450 MHz center-frequency band) on T cell development and function. Pregnant mice were exposed whole body to a specific absorption rate of 4 W/kg, 2 h per day, starting 5 days after mating and ending 1 day before the expected delivery. Sham-exposed and cage control groups were used as controls. No effects on cell count, phenotype, and proliferation of thymocytes were observed. Also, spleen cell count, CD4/CD8 cell frequencies, T cell proliferation, and cytokine production were not affected by the exposure. These findings were consistently observed in the male and female offspring at early (5 weeks of age) and late (26 weeks of age) time points. Nevertheless, the expected differences associated with aging and/or gender were confirmed. In conclusion, our results do not support the hypothesis that the exposure to WiFi signals during prenatal life results in detrimental effects on the immune T cell compartment.

  4. [Fascia compartment syndrome of the iliac-psoas compartment].

    PubMed

    Klammer, A

    1983-01-01

    The iliacus compression syndrome has a kind of exceptional position--as to genesis, development and therapy--in comparison with the other compartment-compression syndromes of the limbs. Indeed there exist similar pathophysiological, rules, but the special anatomic facts enlarge the etiological, differential-diagnostic and therapeutic spectrum. Thus, concerning the frequency of causes, not the trauma but the spontaneous bleeding in coagulation disturbances takes the first place, and unusual causes, such as rupturing aortic aneurysms, have to be included in the differential diagnostic discussion. The finest diagnostic sign besides pain is the palsy of the Nervus Femoralis. As to the treatment, operative measures are possible. The exact knowledge of the anatomy is important for the understanding of the specialties mentioned above.

  5. Stability of bacterial carotenoids in the presence of iron in a model of the gastric compartment - comparison with dietary reference carotenoids.

    PubMed

    Sy, Charlotte; Dangles, Olivier; Borel, Patrick; Caris-Veyrat, Catherine

    2015-04-15

    Recently isolated spore-forming pigmented marine bacteria, Bacillus indicus HU36 and Bacillus firmus GB1 are sources of carotenoids (∼fifteen distinct yellow and orange pigments and ∼thirteen distinct pink pigments, respectively). They are glycosides of oxygenated lycopene derivatives (apo-lycopenoids) and are assumed to be more heat- and gastric-stable than common carotenoids. In this study, the oxidation by O2 of the bacterial carotenoids was initiated by free iron (Fe(II) and Fe(III)) or by heme iron (metmyoglobin) in a mildly acidic aqueous solution mimicking the gastro-intestinal compartment and compared to the oxidation of the common dietary carotenoids β-carotene, lycopene and astaxanthin. Under these conditions, all bacterial carotenoids appear more stable in the presence of heme iron vs. free iron. Carotenoid autoxidation initiated by Fe(II) is relatively fast and likely involves reactive oxygen-iron species derived from Fe(II) and O2. By contrast, the corresponding reaction with Fe(III) is kinetically blocked by the slow preliminary reduction of Fe(III) into Fe(II) by the carotenoids. The stability of carotenoids toward autoxidation increases as follows: β-carotene

  6. Independent Active Contraction of Extraocular Muscle Compartments

    PubMed Central

    Shin, Andrew; Yoo, Lawrence; Demer, Joseph L.

    2015-01-01

    Purpose. Intramuscular innervation of horizontal rectus extraocular muscle (EOMs) is segregated into superior and inferior (transverse) compartments, whereas all EOMs are also divided into global (GL) and orbital (OL) layers with scleral and pulley insertions, respectively. Mechanical independence between both types of compartments has been demonstrated during passive tensile loading. We examined coupling between EOM compartments during active, ex vivo contraction. Methods. Fresh bovine EOMs were removed, and one compartment of each was coated with hydrophobic petrolatum. Contraction of the uncoated compartment was induced by immersion in a solution of 50 mM CaCl2 at 38°C labeled with sodium fluorescein dye, whereas tensions in both compartments were monitored by strain gauges. Control experiments omitted petrolatum so that the entire EOM contracted. After physiological experiments, EOMs were sectioned transversely to demonstrate specificity of CaCl2 permeation by yellow fluorescence dye excited by blue light. Results. In control experiments without petrolatum, both transverse and GL and OL compartments contracted similarly. Selective compartmental omission of petrolatum caused markedly independent compartmental contraction whether measured at the GL or the OL insertions or for transverse compartments at the scleral insertion. Although some CaCl2 spread occurred, mean (±SD) tension in the coated compartments averaged only 10.5 ± 3.3% and 6.0 ± 1.5% in GL/OL and transverse compartments, respectively relative to uncoated compartments. Fluorescein penetration confirmed selective CaCl2 permeation. Conclusions. These data confirm passive tensile findings of mechanical independence of EOM compartments and extend results to active contraction. EOMs behave actively as if composed of mechanically independent parallel fiber bundles having different insertional targets, consistent with the active pulley and transverse compartmental hypotheses. PMID:25503460

  7. Abdominal Compartment Syndrome After Hip Arthroscopy

    DTIC Science & Technology

    2010-01-01

    K. Intra- abdominal compartment syndrome as a complication of ruptured abdomi- nal aortic aneurysm repair. Am Surg 1989;55:396-402. 6. Sugrue M...00-00-2010 to 00-00-2010 4. TITLE AND SUBTITLE Abdominal Compartment Syndrome After Hip Arthroscopy 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c...unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 Author’s personal copy Case Report Abdominal Compartment Syndrome After

  8. Compartment syndrome after tibial plateau fracture.

    PubMed

    Pitta, Guilherme Benjamin Brandão; Dos Santos, Thays Fernanda Avelino; Dos Santos, Fernanda Thaysa Avelino; da Costa Filho, Edelson Moreira

    2014-01-01

    Fractures of the tibial plateau are relatively rare, representing around 1.2% of all fractures. The tibia, due to its subcutaneous location and poor muscle coverage, is exposed and suffers large numbers of traumas, not only fractures, but also crush injuries and severe bruising, among others, which at any given moment, could lead compartment syndrome in the patient. The case is reported of a 58-year-old patient who, following a tibial plateau fracture, presented compartment syndrome of the leg and was submitted to decompressive fasciotomy of the four right compartments. After osteosynthesis with internal fixation of the tibial plateau using an L-plate, the patient again developed compartment syndrome.

  9. A 4-compartment model based validation of air displacement plethysmography, dual energy X-ray absorptiometry, skinfold technique & bio-electrical impedance for measuring body fat in Indian adults

    PubMed Central

    Kuriyan, Rebecca; Thomas, Tinku; Ashok, Sangeetha; J, Jayakumar; Kurpad, Anura V.

    2014-01-01

    Background & objectives: Many methods are available for measuring body fat of an individual, each having its own advantages and limitations. The primary objective of the present study was to validate body fat estimates from individual methods using the 4-compartment (4C) model as reference. The second objective was to obtain estimates of hydration of fat free mass (FFM) using the 4C model. Methods: The body fat of 39 adults (19 men and 20 women) aged 20-40 yr was estimated using air displacement plethysmography (ADP), dual energy X-ray absorptiometry (DEXA), 4-skinfold technique and bio-electrical impedance (BIA). Total body water was estimated using isotope dilution method. Results: All the methods underestimated body fat when compared to 4C model, except for DEXA and the mean difference from the reference was lowest for DEXA and ADP. The precision of the fat mass estimated from 4C model using the propagation of error was 0.25 kg, while the mean hydration factor obtained by the 4C model was found to be 0.74 ± 0.02 in the whole group of men and women. Interpretations & conclusion: The results of the present study suggest that DEXA and ADP methods can provide reasonably accurate estimates of body fat, while skinfold and bio-electrical impedance methods require the use of population specific equations. PMID:25027079

  10. CAirTOX: A compartment model for assessing the fate of and human exposure to toxic-chemical emissions to air

    SciTech Connect

    McKone, T.E.

    1993-10-01

    CAirTOX has been developed as a spreadsheet model to assist in making a risk assessment of toxic air emissions. With CAirTOX, one can address how contaminants released to an air basin can lead to contamination of soil, food, surface water, and sediments. The modeling effort includes a multimedia transport and transformation model, exposure scenario models, and efforts to quantify uncertainty in multimedia, multiple-pathway exposure assessments. The multimedia transport and transformation model is a steady-state, but non-equilibrium model that can be used to assess concentrations of contaminants released continuously to air. In Part 1, the authors describe the multimedia transport and transformation model used to determine the fate of air emissions. In Part 2, they describe inputs and data needs for CAirTOX and the development of a set of landscape factors, which can be used to represent regional air basin/water-shed systems in California. In Part 3, they describe the multiple-pathway exposure scenarios and exposure algorithms. In Part 4, they compare the HRA approach and results and the CAirTOX exposure equations. In Part 5, they consider model sensitivity and uncertainty to determine how variability and uncertainty in model inputs affects the precision, accuracy, and credibility of the model output.

  11. Compartmented mode workstation (CMW) comparisons

    SciTech Connect

    Tolliver, J.S.

    1995-12-31

    As the Compartmented Mode Workstation (CMW) market has matured, several vendors have released new versions of their CMW operating systems. These include a new version from SecureWare (CMW + Version 2.4), and Sun`s CMW 1.1 (also known as Trusted Solaris 1.1). EC is now shipping MLS+ 3.0 for DEC Alpha platforms. Relatively new entries in the market include Loral B1/CMW for IBM RS/6000 platforms and a SecureWare-based CMW for HP platforms (HP-UX 10.09). With all these choices it is time for a comparative analysis of the features offered by the various vendors. The authors have three of the above five CMW systems plus HP-UX BLS 9.09, which is a multilevel secure operating system (OS) targeted at the B1 level but not a CMW. Each is unique in sometimes obvious, sometimes subtle ways, a situation that requires knowing and keeping straight a variety of commands to do the same thing on each system. Some vendors offer extensive GUI tools for system administration; some require entering command-line commands for certain system administration tasks. They examine the differences in system installation, system administration, and system operating among the systems. They look at trusted networking among the various systems and differences in the network databases and label encodings files. They examine the user interface on the various systems from logging in to logging out.

  12. A compartment model of alveolar-capillary oxygen diffusion with ventilation-perfusion gradient and dynamics of air transport through the respiratory tract.

    PubMed

    Jaworski, Jacek; Redlarski, Grzegorz

    2014-08-01

    This paper presents a model of alveolar-capillary oxygen diffusion with dynamics of air transport through the respiratory tract. For this purpose electrical model representing the respiratory tract mechanics and differential equations representing oxygen membrane diffusion are combined. Relevant thermodynamic relations describing the mass of oxygen transported into the human body are proposed as the connection between these models, as well as the influence of ventilation-perfusion mismatch on the oxygen diffusion. The model is verified based on simulation results of varying exercise intensities and statistical calculations of the results obtained during various clinical trials. The benefit of the approach proposed is its application in simulation-based research aimed to generate quantitative data of normal and pathological conditions. Based on the model presented, taking into account many essential physiological processes and air transport dynamics, comprehensive and combined studies of the respiratory efficiency can be performed. The impact of physical exercise, precise changes in respiratory tract mechanics and alterations in breathing pattern can be analyzed together with the impact of various changes in alveolar-capillary oxygen diffusion. This may be useful in simulation of effects of many severe medical conditions and increased activity level.

  13. Dose-response analysis of infants prenatally exposed to methyl mercury: An application of a single compartment model to single-strand hair analysis

    SciTech Connect

    Cox, C.; Clarkson, T.W.; Marsh, D.O.; Amin-Zaki, L.; Tikriti, S.; Myers, G.G. )

    1989-08-01

    A new method of estimating fetal exposure is used in a dose-response analysis of data from the 1971 outbreak of methyl mercury poisoning in rural Iraq. An X-ray fluorescence instrument for the measurement of single strands of human hair was employed to obtain longitudinal profiles recapitulating fetal exposure. Logit and hockey-stick models as well as nonparametric smoothing are used to describe data on delayed development and central nervous system abnormality.

  14. Dendritic distributions of Ih channels in experimentally-derived multi-compartment models of oriens-lacunosum/moleculare (O-LM) hippocampal interneurons

    PubMed Central

    Sekulić, Vladislav; Chen, Tse-Chiang; Lawrence, J. Josh; Skinner, Frances K.

    2015-01-01

    The O-LM cell type mediates feedback inhibition onto hippocampal pyramidal cells and gates information flow in the CA1. Its functions depend on the presence of voltage-gated channels (VGCs), which affect its integrative properties and response to synaptic input. Given the challenges associated with determining densities and distributions of VGCs on interneuron dendrites, we take advantage of computational modeling to consider different possibilities. In this work, we focus on hyperpolarization-activated channels (h-channels) in O-LM cells. While h-channels are known to be present in O-LM cells, it is unknown whether they are present on their dendrites. In previous work, we used ensemble modeling techniques with experimental data to obtain insights into potentially important conductance balances. We found that the best O-LM models that included uniformly distributed h-channels in the dendrites could not fully capture the “sag” response. This led us to examine activation kinetics and non-uniform distributions of h-channels in the present work. In tuning our models, we found that different kinetics and non-uniform distributions could better reproduce experimental O-LM cell responses. In contrast to CA1 pyramidal cells where higher conductance densities of h-channels occur in more distal dendrites, decreasing conductance densities of h-channels away from the soma were observed in O-LM models. Via an illustrative scenario, we showed that having dendritic h-channels clearly speeds up back-propagating action potentials in O-LM cells, unlike when h-channels are present only in the soma. Although the present results were morphology-dependent, our work shows that it should be possible to determine the distributions and characteristics of O-LM cells with recordings and morphologies from the same cell. We hypothesize that h-channels are distributed in O-LM cell dendrites and endow them with particular synaptic integration properties that shape information flow in

  15. Use of a Microsoft Excel based add-in program to calculate plasma sinistrin clearance by a two-compartment model analysis in dogs.

    PubMed

    Steinbach, Sarah M L; Sturgess, Christopher P; Dunning, Mark D; Neiger, Reto

    2015-06-01

    Assessment of renal function by means of plasma clearance of a suitable marker has become standard procedure for estimation of glomerular filtration rate (GFR). Sinistrin, a polyfructan solely cleared by the kidney, is often used for this purpose. Pharmacokinetic modeling using adequate software is necessary to calculate disappearance rate and half-life of sinistrin. The purpose of this study was to describe the use of a Microsoft excel based add-in program to calculate plasma sinistrin clearance, as well as additional pharmacokinetic parameters such as transfer rates (k), half-life (t1/2) and volume of distribution (Vss) for sinistrin in dogs with varying degrees of renal function.

  16. Shaped Charge Jet/Propellant Interactions in a Vented Compartment.

    DTIC Science & Technology

    1979-12-01

    the vented ammunition compartment. One of these was the Susquehanna Instruments Model ST-4 tourmaline transducer, a nonresonant transducer capable of...S1-4 tourmaline gauges and those at positons 3 and 4 were Kistler Model 617A tourmaline gauges. Thin strips of metal were welded over the trans- ducers...two different types of piezoelectric transducers. One was a fast almost totally non- resonant though somewhat temperature sensitive Tourmaline bar gauge

  17. 49 CFR 38.127 - Sleeping compartments.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... SPECIFICATIONS FOR TRANSPORTATION VEHICLES Intercity Rail Cars and Systems § 38.127 Sleeping compartments. (a...., heating and air conditioning controls, lighting controls, call buttons, electrical outlets, etc.) shall...

  18. Compartment syndrome after tibial plateau fracture☆

    PubMed Central

    Pitta, Guilherme Benjamin Brandão; dos Santos, Thays Fernanda Avelino; dos Santos, Fernanda Thaysa Avelino; da Costa Filho, Edelson Moreira

    2014-01-01

    Fractures of the tibial plateau are relatively rare, representing around 1.2% of all fractures. The tibia, due to its subcutaneous location and poor muscle coverage, is exposed and suffers large numbers of traumas, not only fractures, but also crush injuries and severe bruising, among others, which at any given moment, could lead compartment syndrome in the patient. The case is reported of a 58-year-old patient who, following a tibial plateau fracture, presented compartment syndrome of the leg and was submitted to decompressive fasciotomy of the four right compartments. After osteosynthesis with internal fixation of the tibial plateau using an L-plate, the patient again developed compartment syndrome. PMID:26229779

  19. Understanding supported reactions in spherical compartments: a general algorithm to model and determine rate constants, diffusion coefficients, and spatial product distributions.

    PubMed

    Egelhaaf, Hans-Joachim; Rademann, Jörg

    2005-01-01

    A general algorithm allowing the numerical modeling of the time and space dependence of product formation in spherical reaction volumes is described. The algorithm is described by the complete set of mass balance equations. On the basis of these equations, the effects of the diffusion coefficient, reaction rate, bead size, reagent excess, and packing density of the resin beads on the overall reaction rates are determined for second-order reactions. Experimental data of reaction progress are employed to calculate reaction rates and diffusion coefficients in polymer-supported reactions. In addition, the conditions for shell-like product formation are determined, and various strategies for the radial patterning of resin beads are compared. The effect of diffusion on polymer-supported enzyme-catalyzed reactions of the Michaelis-Menten type is treated, as well. Finally, the effects of typical nonideal solid-phase phenomena, namely, the inhomogeneity of rate constants and the concentration dependence of diffusion coefficients, on overall rates are discussed.

  20. Aircraft Cargo Compartment Fire Test Simulation Program

    NASA Technical Reports Server (NTRS)

    Blumke, R. E.

    1977-01-01

    The objective of the test was to assess fire containment and fire extinguishment in the cargo by reducing the ventilation through the cargo compartment. Parameters which were measured included ignition time, burnthrough time, and physical damage to the cargo liner, composition of selected combustible gases, temperature-time histories, heat flux, and detector response. The ignitor load was made of a typical cargo consisting of filled cardboard cartons occupying 50% of the compartment volume.

  1. Current concepts in the pathophysiology, evaluation, and diagnosis of compartment syndrome

    NASA Technical Reports Server (NTRS)

    Hargens, A. R.; Mubarak, S. J.

    1998-01-01

    This article reviews present knowledge of the pathophysiology and diagnosis of acute compartment syndromes. Recent results using compression of legs in normal volunteers provide objective data concerning local pressure thresholds for neuromuscular dysfunction in the anterior compartment. Results with this model indicate that a progression of neuromuscular deficits occurs when IMP increases to within 35 to 40 mm Hg of diastolic blood pressure. These findings provide useful information on the diagnosis and compression thresholds for acute compartment syndromes. Time factors are also important, however, and usually are incompletely known in most cases of acute compartment syndrome. Although the slit catheter is a very good technique for monitoring IMP during rest, these catheters and their associated extracorporeal transducer systems are not ideal. Recently developed miniature transducer-tipped catheters and, perhaps, future development of noninvasive techniques may provide accurate recordings of IMP in patients with acute compartment syndromes.

  2. Understanding tumor heterogeneity as functional compartments--superorganisms revisited.

    PubMed

    Grunewald, Thomas G P; Herbst, Saskia M; Heinze, Jürgen; Burdach, Stefan

    2011-05-27

    Compelling evidence broadens our understanding of tumors as highly heterogeneous populations derived from one common progenitor. In this review we portray various stages of tumorigenesis, tumor progression, self-seeding and metastasis in analogy to the superorganisms of insect societies to exemplify the highly complex architecture of a neoplasm as a system of functional "castes."Accordingly, we propose a model in which clonal expansion and cumulative acquisition of genetic alterations produce tumor compartments each equipped with distinct traits and thus distinct functions that cooperate to establish clinically apparent tumors. This functional compartment model also suggests mechanisms for the self-construction of tumor stem cell niches. Thus, thinking of a tumor as a superorganism will provide systemic insight into its functional compartmentalization and may even have clinical implications.

  3. Relationship between mean body temperature calculated by two- or three-compartment models and active cutaneous vasodilation in humans: a comparison between cool and warm environments during leg exercise

    NASA Astrophysics Data System (ADS)

    Demachi, Koichi; Yoshida, Tetsuya; Tsuneoka, Hideyuki

    2012-03-01

    The aim of this study was to assess whether the three-compartment model of mean body temperature (Tb3) calculated from the esophageal temperature (Tes), temperature in deep tissue of exercising muscle (Tdt), and mean skin temperature (Tsk) has the potential to provide a better match with the thermoregulatory responses than the two-component model of mean body temperature (Tb2) calculated from Tes and Tsk. Seven male subjects performed 40 min of a prolonged cycling exercise at 30% maximal oxygen uptake at 21°C or 31°C (50% relative humidity). Throughout the experiment, Tsk, Tb2, Tb3, and Tdt were significantly ( P < 0.01) lower at 21°C than at 31°C temperature conditions, while Tes was similar under both conditions. During exercise, an increase in cutaneous vascular conductance (skin blood flow / mean arterial pressure) over the chest (%CVCc) was observed at both 21°C and 31°C, while no increase was observed at the forearm at 21°C. Furthermore, the Tb3 and Tdt threshold for the onset of the increase in %CVCc was similar, but the Tes and Tb2 threshold differed significantly ( P < 0.05) between the conditions tested. These results suggest that active cutaneous vasodilation at the chest is related more closely to Tb3 or Tdt than that measured by Tes or Tb2 calculated by Tes and Tsk during exercise at both 21°C and 31°C.

  4. Anatomic Landmarks for the First Dorsal Compartment

    PubMed Central

    Hazani, Ron; Engineer, Nitin J.; Cooney, Damon; Wilhelmi, Bradon J.

    2008-01-01

    Objective: Knowledge of anatomic landmarks for the first dorsal compartment can assist clinicians with management of de Quervain's disease. The radial styloid, the scaphoid tubercle, and Lister's tubercle can be used as superficial landmarks for the first dorsal compartment. Methods: Thirty-two cadaveric wrists were dissected, and measurements were taken from the predetermined landmarks to the extensor retinaculum. The compartments were also inspected for variability of the abductor pollicis longus tendon and intracompartmental septations. Results: The average length of the extensor retinaculum from its proximal to distal extent measured approximately 2.2 cm. The distal aspect of the radial styloid was 0.3 cm distal to the distal aspect of the extensor retinaculum, and the distance between the distal aspect of the extensor retinaculum and the APL-Lister's-Scaphoid juncture was approximately 0.5 cm. A separate compartment for the extensor pollicis brevis was noted in 35% of the specimens. The abductor pollicis longus tendon demonstrated great variability with 1, 2, 3, or 4 slips in 9%, 30%, 43%, or 26% of the specimens, respectively. Conclusion: The superficial bony prominences of the radial wrist can be used reliably as anatomic landmarks for the first dorsal compartment. PMID:19092992

  5. [The perichromatin compartment of the cell nucleus].

    PubMed

    Bogoliubov, D S

    2014-01-01

    In this review, the data on the structure and composition of the perichromatin compartment, a special border area between the condensed chromatin and the interchromatin space of the cell nucleus, are discussed in the light of the concept of nuclear functions in complex nuclear architectonics. Morphological features, molecular composition and functions of main extrachromosomal structures of the perichromatin compartment, perichromatin fibrils (PFs) and perichromatin granules (PGs) including nuclear stress-bodies (nSBs) that are derivates of the PGs under heat shock, are presented. A special attention was paid to the features of the molecular compositions of PFs and PGs in different cell types and at different physiological conditions.

  6. Gluteal Compartment Syndrome Secondary to Pelvic Trauma

    PubMed Central

    Taype Zamboni, Danilo E. R.; Carabelli, Guido S.; Barla, Jorge D.; Sancineto, Carlos F.

    2016-01-01

    Gluteal compartment syndrome (GCS) is extremely rare when compared to compartment syndrome in other anatomical regions, such as the forearm or the lower leg. It usually occurs in drug users following prolonged immobilization due to loss of consciousness. Another possible cause is trauma, which is rare and has only few reports in the literature. Physical examination may show tense and swollen buttocks and severe pain caused by passive range of motion. We present the case of a 70-year-old man who developed GCS after prolonged anterior-posterior pelvis compression. The physical examination revealed swelling, scrotal hematoma, and left ankle extension weakness. An unstable pelvic ring injury was diagnosed and the patient was taken to surgery. Measurement of the intracompartmental pressure was measured in the operating room, thereby confirming the diagnosis. Emergent fasciotomy was performed to decompress the three affected compartments. Trauma surgeons must be aware of the possibility of gluteal compartment syndrome in patients who have an acute pelvic trauma with buttock swelling and excessive pain of the gluteal region. Any delay in diagnosis or treatment can be devastating, causing permanent disability, irreversible loss of gluteal muscles, sciatic nerve palsy, kidney failure, or even death. PMID:27579205

  7. Design/Development of Spacecraft and Module Crew Compartments

    NASA Technical Reports Server (NTRS)

    Goodman, Jerry R.

    2010-01-01

    This slide presentation reviews the design and development of crew compartments for spacecraft and for modules. The Crew Compartment or Crew Station is defined as the spacecraft interior and all other areas the crewman interfaces inside the cabin, or may potentially interface.It uses examples from all of the human rated spacecraft. It includes information about the process, significant drivers for the design, habitability, definitions of models, mockups, prototypes and trainers, including pictures of each stage in the development from Apollo, pictures of the space shuttle trainers, and International Space Station trainers. It further reviews the size and shape of the Space Shuttle orbiter crew compartment, and the Apollo command module and the lunar module. It also has a chart which reviews the International Space Station (ISS) internal volume by stage. The placement and use of windows is also discussed. Interestingly according to the table presented, the number 1 rated piece of equipment for recreation was viewing windows. The design of crew positions and restraints, crew translation aids and hardware restraints is shown with views of the restraints and handholds used from the Apollo program through the ISS.

  8. The statolith compartment in Chara rhizoids contains carbohydrate and protein

    NASA Technical Reports Server (NTRS)

    Wang-Cahill, F.; Kiss, J. Z.

    1995-01-01

    In contrast to higher plants, the alga Chara has rhizoids with single membrane-bound compartments that function as statoliths in gravity perception. Previous work has demonstrated that these statoliths contain barium sulfate crystals. In this study, we show that statoliths in Chara rhizoids react with a Coomassie Brilliant Blue cytochemical stain for proteins. While statoliths did not react with silver methenamine carbohydrate cytochemistry, the monoclonal antibody CCRC-M2, which is against a carbohydrate (sycamore-maple rhamnogalacturonan I), labeled the statolith compartment. These results demonstrate that in addition to barium sulfate, statoliths in Chara rhizoids have an organic matrix that consists of protein and carbohydrate moieties. Since the statoliths were silver methenamine negative, the carbohydrate in this compartment could be a 3-linked polysaccharide. CCRC-M2 also labeled Golgi cisternae, Golgi-associated vesicles, apical vesicles, and cell walls in the rhizoids. The specificity of CCRC-M2 immunolabeling was verified by several control experiments, including the demonstration that labeling was abolished when the antibody was preabsorbed with its antigen. Since in this and a previous study (John Z. Kiss and L. Andrew Staehelin, American Journal of Botany 80: 273-282, 1993) antibodies against higher plant carbohydrates crossreacted with cell walls of Chara in a specific manner, Characean algae may be a useful model system in biochemical and molecular studies of cell walls.

  9. Isolation of the lateral border recycling compartment using a diaminobenzidine-induced density shift.

    PubMed

    Sullivan, David P; Rüffer, Claas; Muller, William A

    2014-09-01

    The migration of leukocytes across the endothelium and into tissue is critical to mounting an inflammatory response. The lateral border recycling compartment (LBRC), a complex vesicular-tubule invagination of the plasma membrane found at endothelial cell borders, plays an important role in this process. Although a few proteins have been shown to be present in the LBRC, no unique marker is known. Here, we detail methods that can be used to characterize a subcellular compartment that lacks an identifying marker. Initial characterization of the LBRC was performed using standard subcellular fractionation with sucrose gradients and took advantage of the observation that the compartment migrated at a lower density than other membrane compartments. To isolate larger quantities of the compartment, we modified a classic technique known as a diaminobenzidine (DAB)-induced density shift. The DAB-induced density shift allowed for specific isolation of membranes labeled with horseradish peroxidase-conjugated antibody. Because the LBRC could be differentially labeled at 4 °C and 37 °C, we were able to identify proteins that are enriched in the compartment, despite lacking a unique marker. These methods serve as a model to others studying poorly characterized compartments and organelles and are applicable to a wide variety of biological systems.

  10. Extraocular Muscle Compartments in Superior Oblique Palsy

    PubMed Central

    Suh, Soh Youn; Clark, Robert A.; Le, Alan; Demer, Joseph L.

    2016-01-01

    Purpose To investigate changes in volumes of extraocular muscle (EOM) compartments in unilateral superior oblique (SO) palsy using magnetic resonance imaging (MRI). Methods High-resolution, surface-coil MRI was obtained in 19 patients with unilateral SO palsy and 19 age-matched orthotropic control subjects. Rectus EOMs and the SO were divided into two anatomic compartments for volume analysis in patients with unilateral SO palsy, allowing comparison of total compartmental volumes versus controls. Medial and lateral compartmental volumes of the SO muscle were compared in patients with isotropic (round shape) versus anisotropic (elongated shape) SO atrophy. Results The medial and lateral compartments of the ipsilesional SO muscles were equally atrophic in isotropic SO palsy, whereas the lateral compartment was significantly smaller than the medial in anisotropic SO palsy (P = 0.01). In contrast to the SO, there were no differential compartmental volume changes in rectus EOMs; however, there was significant total muscle hypertrophy in the ipsilesional inferior rectus (IR) and lateral rectus (LR) muscles and contralesional superior rectus (SR) muscles. Medial rectus (MR) volume was normal both ipsi- and contralesionally. Conclusions A subset of patients with SO palsy exhibit selective atrophy of the lateral, predominantly vertically acting SO compartment. Superior oblique atrophy is associated with whole-muscle volume changes in the ipsilesional IR, ipsilesional LR, and contralesional SR; however, SO muscle atrophy is not associated with compartmentally selective volume changes in the rectus EOMs. Selective compartmental SO pathology may provide an anatomic mechanism that explains some of the variability in clinical presentations of SO palsy. PMID:27768791

  11. Acute exertional anterior compartment syndrome in an adolescent female.

    PubMed

    Fehlandt, A; Micheli, L

    1995-01-01

    Acute compartment syndromes usually occur as a complication of major trauma. While the chronic exertional anterior tibial compartment syndrome is well described in the sports medicine literature, reports of acute tibial compartment syndromes due to physical exertion, or repetitive microtrauma, are rare. The case of an adolescent female who developed an acute anterior compartment syndrome from running in a soccer game is described in this report. Failure to recognize the onset of an acute exertional compartment syndrome may lead to treatment delay and serious complications. Whereas the chronic exertional anterior compartment syndrome is characterized by pain that diminishes with the cessation of exercise, the onset of the acute exertional anterior compartment syndrome is heralded by pain that continues, or increases, after exercise has stopped. Compartment pressure measurement confirms the clinical diagnosis and helps guide treatment. True compartment syndromes require urgent fasciotomy.

  12. Decompressive laparotomy for abdominal compartment syndrome

    PubMed Central

    Kimball, E.; Malbrain, M.; Nesbitt, I.; Cohen, J.; Kaloiani, V.; Ivatury, R.; Mone, M.; Debergh, D.; Björck, M.

    2016-01-01

    Background The effect of decompressive laparotomy on outcomes in patients with abdominal compartment syndrome has been poorly investigated. The aim of this prospective cohort study was to describe the effect of decompressive laparotomy for abdominal compartment syndrome on organ function and outcomes. Methods This was a prospective cohort study in adult patients who underwent decompressive laparotomy for abdominal compartment syndrome. The primary endpoints were 28‐day and 1‐year all‐cause mortality. Changes in intra‐abdominal pressure (IAP) and organ function, and laparotomy‐related morbidity were secondary endpoints. Results Thirty‐three patients were included in the study (20 men). Twenty‐seven patients were surgical admissions treated for abdominal conditions. The median (i.q.r.) Acute Physiology And Chronic Health Evaluation (APACHE) II score was 26 (20–32). Median IAP was 23 (21–27) mmHg before decompressive laparotomy, decreasing to 12 (9–15), 13 (8–17), 12 (9–15) and 12 (9–14) mmHg after 2, 6, 24 and 72 h. Decompressive laparotomy significantly improved oxygenation and urinary output. Survivors showed improvement in organ function scores, but non‐survivors did not. Fourteen complications related to the procedure developed in eight of the 33 patients. The abdomen could be closed primarily in 18 patients. The overall 28‐day mortality rate was 36 per cent (12 of 33), which increased to 55 per cent (18 patients) at 1 year. Non‐survivors were no different from survivors, except that they tended to be older and on mechanical ventilation. Conclusion Decompressive laparotomy reduced IAP and had an immediate effect on organ function. It should be considered in patients with abdominal compartment syndrome. PMID:26891380

  13. Perfluoroalkyl acid distribution in various plant compartments ...

    EPA Pesticide Factsheets

    Crop uptake of perfluoroalkyl acids (PFAAs) from biosolids-amended soil has been identified as a potential pathway for PFAA entry into the terrestrial food chain. This study compared the uptake of PFAAs in greenhouse-grown radish (Raphanus sativus), celery (Apium graveolens var.dulce), tomato (Lycopersicon lycopersicum), and sugar snap pea (Pisum sativum var. macrocarpon) from an industrially impacted biosolids-amended soil, a municipal biosolids­ amended soil, and a control soil. Individual concentrations of PFAAs, on a dry weight basis, in mature, edible portions of crops grown in soil amended with PFAA industrially impacted biosolids were highest for perfluorooctanoate (PFOA; 67 ng/g) in radish root, perfluorobutanoate (PFBA;232 ng/g) in celery shoot, and PFBA (150 ng/g) in pea fruit. Comparatively, PFAA concentrations in edible compartments of crops grown in the municipal biosolids-amended soil and in the control soil were less than 25 ng/g. Bioaccumulation factors (BAFs) were calculated for the root, shoot, and fruit compartments (as applicable) of all crops grown in the industrially impacted soil. BAFs were highest for PFBA in the shoots of all crops, as well as in the fruit compartment of pea. Root­ soil concentration factors (RCFs) for tomato and pea were independent of PFAA chain length, while radish and celery RCFs showed a slight decrease with increasing chain length. Shoot-soil concentration factors (SCFs) for all crops showed a decrease with incre

  14. Compartment-Specific Phosphorylation of Squid Neurofilaments.

    PubMed

    Grant, Philip; Pant, Harish C

    2016-01-01

    Studies of the giant axon and synapse of third-order neurons in the squid stellate ganglion have provided a vast literature on neuronal physiology and axon transport. Large neuronal size also lends itself to comparative biochemical studies of cell body versus axon. These have focused on the regulation of synthesis, assembly, posttranslational modification and function of neuronal cytoskeletal proteins (microtubules (MTs) and neurofilaments (NFs)), the predominant proteins in axoplasm. These contribute to axonal organization, stability, transport, and impulse transmission responsible for rapid contractions of mantle muscles underlying jet propulsion. Studies of vertebrate NFs have established an extensive literature on NF structure, organization, and function; studies of squid NFs, however, have made it possible to compare compartment-specific regulation of NF synthesis, assembly, and function in soma versus axoplasm. Since NFs contain over 100 eligible sites for phosphorylation by protein kinases, the compartment-specific patterns of phosphorylation have been a primary focus of biochemical studies. We have learned that NF phosphorylation is tightly compartmentalized; extensive phosphorylation occurs only in the axonal compartment in squid and in vertebrate neurons. This extensive phosphorylation plays a key role in organizing NFs, in association with microtubules (MTs), into a stable, dynamic functional lattice that supports axon growth, diameter, impulse transmission, and synaptic activity. To understand how cytoskeletal phosphorylation is topographically regulated, the kinases and phosphatases, bound to NFs isolated from cell bodies and axoplasm, have also been studied.

  15. 14 CFR 29.787 - Cargo and baggage compartments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Personnel and Cargo Accommodations § 29.787 Cargo and baggage compartments. (a) Each cargo and baggage compartment must be...

  16. 14 CFR 27.787 - Cargo and baggage compartments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Personnel and Cargo Accommodations § 27.787 Cargo and baggage compartments. (a) Each cargo and baggage compartment must be...

  17. 14 CFR 25.365 - Pressurized compartment loads.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Pressurized compartment loads. 25.365... an engine disintegration; (2) Any opening in any pressurized compartment up to the size Ho in square... small compartment. The size Ho must be computed by the following formula: Ho=PAs where,...

  18. Evolution of trochlear compartment geometry in total knee arthroplasty

    PubMed Central

    Demey, Guillaume; Nover, Luca; Dejour, David

    2016-01-01

    Background The study aimed to compare trochlear profiles in recent total knee arthroplasty (TKA) models and to determine whether they feature improvements compared to their predecessors. The hypothesis was that recent TKA models have more anatomic trochlear compartments and would display no signs of trochlear dysplasia. Methods The authors analyzed the geometry of the 6 following TKA models using engineering software: PFC and Attune (DePuy), NexGen and Persona (Zimmer), Noetos and KneeTec (Tornier). The mediolateral trochlear profiles were plotted at various flexion angles (0°, 15°, 30° and 45°) to deduce the sulcus angle. Results Analysis of sulcus angles reveals general convergence of recent designs towards anatomic values. At 0° of flexion, sulcus angles of recent implant models were between 156.0–157.4°, while those of previous generation models between 154.5–165.5°. At 30° of flexion, sulcus angles of recent models also lie within 145.7–148.6°, but those of previous models are between 149.5–152.0°. All three manufacturers deepened their trochlear profile at 30° of flexion in recent models compared to earlier designs. Sulcus angles converge towards anatomic values but still exceed radiologic signs of dysplasia by 2–5°. Conclusions Recent TKA designs have more anatomic trochlear geometries than earlier TKA models by the same manufacturers, but trochlear compartments still exceed radiologic signs of trochlear dysplasia by 2° to 5°. The hypothesis that recent TKA models display no signs of trochlear dysplasia is therefore refuted. Surgeons should be aware of design limitations to optimize choice of implant and extensor mechanisms alignment. Level of evidence: IV geometric implant analysis. PMID:26855943

  19. [Compartment analysis of 123I-IMP brain SPECT].

    PubMed

    Higano, S; Shishido, F; Aizawa, Y; Miura, S; Murakami, M; Inugami, A; Kanno, I; Fujita, H; Uemura, K

    1990-01-01

    To clarify the kinetics of N-isopropyl [123I]p-iodoamphetamine (IMP) in the brain, 2-compartment analysis was applied for brain SPECT with 57-minute dynamic scan in 9 subjects. The model consisted of blood component and brain tissue component. Two transfer rate constants were defined; k1 showed the rate from the blood to the brain tissue, and k2 was that of back diffusion. The late scan was performed 210 minutes after the tracer injection. Suitable k values best fitting to the dynamic data were determined for all regions of interest. Predicted regional cerebral activity at 210 minutes using 57-minute dynamic data was well agreed with measured activity. These showed the kinetics of IMP in the brain was well described by the 2-compartment model. The partition coefficient (k1/k2 ratio) was as large as about 35, and almost constant in the various brain structures including hypoperfused areas. These findings indicated that the initial IMP images reflected the reasonable CBF distribution, which gave relatively reliable CBF values even if using microsphere model.

  20. Uptake of heavy metals to the extracellular and intracellular compartments in three species of aquatic bryophyte.

    PubMed

    Vázquez, M D; López, J; Carballeira, A

    1999-09-01

    Shoot tips of Fontinalis antipyretica, Scapania undulata, and Fissidens polyphyllus were maintained for 60 min with solutions containing 0, 1, 10, 50, 100, or 200 ppm of Cd, Co, Cu, Ni, Pb, or Zn. A sequential extraction procedure was then used to estimate the amounts of the corresponding metal, and of K and Mg, in the extracellular compartment (extraction with NiCl(2) or EDTA), the intracellular compartment (subsequent extraction with cold dilute HNO(3)), and the particulate fraction (subsequent extraction with hot concentrated HNO(3)). In most cases more metal was taken up to the extracellular compartment than to the intracellular compartment, while particulate-fraction content was negligible. The relationship between metal concentration in the water and metal content in the extracellular compartment was well modeled with a Michaelis-Menten-type equation. Results suggest that in S. undulata extracellular cation-binding sites have a high metal affinity, while in F. polyphyllus it is relatively low. However, postincubation intracellular contents were highest in the latter species. The ranking of the six metals by amounts taken up into the intracellular compartment was the same for all three bryophyte species. Uptake of heavy metals led to considerable losses of intracellular K (probably due to effects on plasma membrane properties), and of extracellular Mg (probably due to displacement from cation-binding sites). Losses of intracellular K were most marked in S. undulata, followed by F. antipyretica. By contrast, S. undulata was the species from which losses of extracellular Mg were lowest.

  1. Actin: its cumbersome pilgrimage through cellular compartments

    PubMed Central

    Schleicher, Michael

    2008-01-01

    In this article, we follow the history of one of the most abundant, most intensely studied proteins of the eukaryotic cells: actin. We report on hallmarks of its discovery, its structural and functional characterization and localization over time, and point to present days’ knowledge on its position as a member of a large family. We focus on the rather puzzling number of diverse functions as proposed for actin as a dual compartment protein. Finally, we venture on some speculations as to its origin. PMID:18438682

  2. [Intraabdominal hypertension and abdominal compartment syndrome].

    PubMed

    Sonne, Morten; Hillingsø, Jens

    2008-02-11

    Intraabdominal hypertension (IAH) and abdominal compartment syndrome (ACS) are rare conditions with high mortality. IAH is an intraabdominal pressure (IAP) above 12 mmHg and ACS an IAP above 20 mmHg with evidence of organ dysfunction. IAP is measured indirectly via the bladder or stomach. Various medical and surgical conditions increase the intraabdominal volume. When the content exceeds the compliance of the abdominal wall, the IAP rises. Increased IAP affects the functioning of the brain, lungs, circulation, kidneys, and bowel. The treatment of ACS is a reduction of IAP.

  3. Microspectroscopy of the photosynthetic compartment of algae.

    PubMed

    Evangelista, Valtere; Frassanito, Anna Maria; Passarelli, Vincenzo; Barsanti, Laura; Gualtieri, Paolo

    2006-01-01

    We performed microspectroscopic evaluation of the pigment composition of the photosynthetic compartments of algae belonging to different taxonomic divisions and higher plants. The feasibility of microspectroscopy for discriminating among species and/or phylogenetic groups was tested on laboratory cultures. Gaussian bands decompositions and a fitting algorithm, together with fourth-derivative transformation of absorbance spectra, provided a reliable discrimination among chlorophylls a, b and c, phycobiliproteins and carotenoids. Comparative analysis of absorption spectra highlighted the evolutionary grouping of the algae into three main lineages in accordance with the most recent endosymbiotic theories.

  4. Ultrasonic Apparatus and Method to Assess Compartment Syndrome

    NASA Technical Reports Server (NTRS)

    Yost, William T. (Inventor); Ueno, Toshiaki (Inventor); Hargens, Alan R. (Inventor)

    2009-01-01

    A process and apparatus for measuring pressure buildup in a body compartment that encases muscular tissue. The method includes assessing the body compartment configuration and identifying the effect of pulsatible components on compartment dimensions and muscle tissue characteristics. This process is used in preventing tissue necrosis, and in decisions of whether to perform surgery on the body compartment for prevention of Compartment Syndrome. An apparatus is used for measuring pressure build-up in the body compartment having components for imparting ultrasonic waves such as a transducer, placing the transducer to impart the ultrasonic waves, capturing the imparted ultrasonic waves, mathematically manipulating the captured ultrasonic waves and categorizing pressure build-up in the body compartment from the mathematical manipulations.

  5. Biodistribution of titanium dioxide from biologic compartments.

    PubMed

    Olmedo, Daniel G; Tasat, Deborah R; Guglielmotti, María Beatriz; Cabrini, Rómulo Luis

    2008-09-01

    The layer of titanium dioxide (TiO(2)) of the implant is chronically exposed to the internal electrolyte milieu in the peri-implant biological compartment. Corrosion results from electrochemical attack and ensuing gradual degradation of the metallic materials and is thus of biological interest when these biomaterials are employed in clinical implantology. Herein we evaluated and compared the chronic effect and the biodistribution of TiO(2) administered subcutaneously or intraperitoneally. We propose that the compartmentalization of titanium in the area of subcutaneous injection would reproduce the biological compartment of the implant and its microenvironment from which metal ions could be released and migrate systemically. Potential TiO(2) deposits were identified and characterized in skin, liver and lung by histological and EDX analyses. After both treatments, the skin, liver, and lungs exhibited histological evidence of TiO(2) deposits. In order to characterize in situ macrophage-like cells, tissue sections were immunohistochemically stained for CD68. Tissue specimens from all organs assayed showed positive staining for anti-macrophage monoclonal antibody CD68 (PGM1). Despite the compartmentalization of titanium within nodular areas in rats treated subcutaneously, systemic migration occurred. We concluded that systemic migration of TiO(2) occurred regardless of the administration route.

  6. Remote detection of pressure compartments. Topical report

    SciTech Connect

    Surdam, R.C.; Boyd, N.; Jiao, Z.; Maucione, D.; Kubicheck, S.

    1996-02-01

    A significant portion of the Cretaceous shale section in the Rocky Mountain Laramide Basins (RMLB) is anomalously pressured and gas saturated. The top of the anomalously pressured zone is identified by marked increases in sonic transit time, hydrocarbon production index (P.I.), clay diagenesis (smectite to illite), and vitrinite reflectance gradients. The driving mechanism of anomalous pressure development and compartmentalization is the generation and storage of liquid hydrocarbons that subsequently partially react to gas, converting the fluid-flow system to a multiphase regime in which capillarity controls permeability; the result is elevated displacement pressure within the shales. Sandstone reservoirs within this anomalously pressured shale section are subdivided stratigraphically and diagenetically into relatively small, isolated pressure or fluid-flow compartments. The saturation of these compartments with hydrocarbons and the subsequent oil-to-gas reaction causes explusion of a significant portion of the free water, resulting in anomalously pressured gas accumulations characterized by depletion drive. The determination of the position and configuration of the pressure boundary between normal and anomalously pressured regimes and the detection and delineation of porosity/permeability `sweet spots` below this boundary are the two most important elements in exploring for basin center gas in the RMLB.

  7. Subcellular storage compartments of bacteriopheophorbide sensitizers

    NASA Astrophysics Data System (ADS)

    Moser, Joerg G.; Dembeck, U.; Hubert, M.; Spengler, Bernhard; Bayer, Rainer; Wagner, Birgit

    1994-03-01

    Fluorescence colocalization with the Golgi specific stain, NBD-ceramide, and the mitochondrial localizing stain, Rhodamine 123, confirmed the earlier assumption that the Golgi apparatus is one of the prominent storage compartments for bacteriopheophorbide esters in OAT 75 SCLC cells and several amelanotic melanoma cell lines (A375, Melur SP18, SkAMel 25). Furthermore, a diffuse staining of mitochondria, of non-structured cytoplasm, and an additional storage in melanine vesicles of the amelanotic melanoma cells suggests further storage compartments with quantitatively different contributions to the phototoxicity of bacteriochlorophyll-derived photosensitizers. Independent observations of early phototoxic effects on microfilamentous networks, enzymatic activities (succinate dehydrogenase, lactate dehydrogenase), and redistribution phenomena following primary uptake of the sensitizers let us assume that only a part of the 108 molecules taken up by a cell contribute directly to phototoxicity. Thus it may be asked if a proper subcellular positioning of only a few sensitizer molecules may have similar phototoxic effects as the huge amounts stored at apparently ineffective sites.

  8. Linking the physical and the socio-economic compartments of an integrated water and land use management model on a river basin scale using an object-oriented water supply model

    NASA Astrophysics Data System (ADS)

    Barthel, Roland; Nickel, Darla; Meleg, Alejandro; Trifkovic, Aleksandar; Braun, Juergen

    Within the framework of the research project ‘GLOWA-Danube’, a model of the water supply sector has been developed. GLOWA-Danube investigates long-term changes in the water cycle of the Upper Danube river basin in light of global change. For this purpose, the decision support system DANUBIA, comprising 15 fully coupled models, has been developed. Within DANUBIA the water supply model (‘WaterSupply’) forms the link between various physical models determining water quality and availability and several socio-economic models determining water consumption and demand. Having a central focus on public drinking water supply, its purpose is to correctly simulate the present day system of water extraction and distribution and the related costs, but also to allow meaningful response to possible future changes of boundary conditions, first and foremost changes in water demand or water availability and quality. Response mechanisms are also envisioned for changes in political and economic boundary conditions, and advances in technology. The model will be used locate critical regions which could experience water stress in the future, but does not aim to find the appropriate solutions or to predict the optimal organisation of water supply in the Danube Basin under such changing conditions. In the object-oriented model structure, both water supply companies (WSC) and communities are represented by main classes. Both classes have a limited view and knowledge of their environment. A community knows where and how much water is consumed and from which WSC it is served. A WSC possesses information regarding extraction sites and water rights, raw water quality and potential collaborating WSC. The WSC can perform actions that are different from ‘business as usual’. These deviations from their usual behaviour can be interpreted by decision makers but should not be regarded as a replacement for the decision-making process itself. The model is conceptualised using object

  9. Integrated Compartment Method appication to the transient heat transfer in gas-cooled reactor

    SciTech Connect

    Chen, N.C.J.; Yeh, G.T.

    1983-01-01

    Integrated Compartment Method (ICM), an effective numerical integration algorithm, was developed to solve the transient heat conduction coupled with convection. Application of the ICM to the mathematical model simulating a graphite test structure heated in an annular flow stream of hot helium has been successfully demonstrated. However, the model validation can not be performed until experimental data become available.

  10. Integrated compartment method application to the transient heat transfer in gas-cooled reactor

    SciTech Connect

    Chen, N.C.J.; Yeh, G.T.

    1983-04-01

    Integrated Compartment Method (ICM), an effective numerical integration algorithm, was developed to solve the transient heat conduction coupled with convection. Application of the ICM to the mathematical model simulating a graphite test structure heated in an annular flow stream of hot helium has been successfully demonstrated. However, the model validation can not be performed until experimental data become available.

  11. The Orbital Workshop Waste Management Compartment

    NASA Technical Reports Server (NTRS)

    1972-01-01

    This image is a wide-angle view of the Orbital Workshop waste management compartment. The waste management facilities presented a unique challenge to spacecraft designers. In addition to collection of liquid and solid human wastes, there was a medical requirement to dry all solid human waste products and to return the residue to Earth for examination. Liquid human waste (urine) was frozen for return to Earth. Total quantities of each astronaut's liquid and solid wastes were precisely measured. Cabin air was drawn into the toilet, shown on the wall at right in this photograph, and over the waste products to generate a flow of the waste in the desired direction. The air was then filtered for odor control and antiseptic purposes prior to being discharged back into the cabin.

  12. Vehicle hydraulic system that provides heat for passenger compartment

    DOEpatents

    Bartley, Bradley E.; Blass, James R.; Gibson, Dennis H.

    2001-01-01

    A vehicle includes a vehicle housing which defines a passenger compartment. Attached to the vehicle housing is a hydraulic system, that includes a hydraulic fluid which flows through at least one passageway within the hydraulic system. Also attached to the vehicle housing is a passenger compartment heating system. The passenger compartment heating system includes a heat exchanger, wherein a portion of the heat exchanger is a segment of the at least one passageway of the hydraulic system.

  13. 14 CFR 25.857 - Cargo compartment classification.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Fire Protection § 25... means to control ventilation and drafts within the compartment so that the extinguishing agent used...

  14. The myofascial compartments of the foot: a cadaver study.

    PubMed

    Ling, Z X; Kumar, V P

    2008-08-01

    Compartment syndrome of the foot requires urgent surgical treatment. Currently, there is still no agreement on the number and location of the myofascial compartments of the foot. The aim of this cadaver study was to provide an anatomical basis for surgical decompression in the event of compartment syndrome. We found that there were three tough vertical fascial septae that extended from the hindfoot to the midfoot on the plantar aspect of the foot. These septae separated the posterior half of the foot into three compartments. The medial compartment containing the abductor hallucis was surrounded medially by skin and subcutaneous fat and laterally by the medial septum. The intermediate compartment, containing the flexor digitorum brevis and the quadratus plantae more deeply, was surrounded by the medial septum medially, the intermediate septum laterally and the main plantar aponeurosis on its plantar aspect. The lateral compartment containing the abductor digiti minimi was surrounded medially by the intermediate septum, laterally by the lateral septum and on its plantar aspect by the lateral band of the main plantar aponeurosis. No distinct myofascial compartments exist in the forefoot. Based on our findings, in theory, fasciotomy of the hindfoot compartments through a modified medial incision would be sufficient to decompress the foot.

  15. Coping with the diagnostic complexities of the compartment syndrome

    NASA Technical Reports Server (NTRS)

    Mubarak, S. J.; Hargens, A. R.; Karkal, S. S.

    1988-01-01

    This review recognizes that, given the various complexities associated with the condition, no pat answers can be given to fit every patient with the compartment syndrome. The authors first give a definition of the syndrome, together with a brief account of how this self-perpetuating pathologic cycle is triggered. Next, they delineate specific anatomical features of compartments that are likely to be involved, and follow this with an inventory of symptoms and signs to look for in suspected cases. After sorting out the entities that can mimic the compartment syndrome, the authors describe three essential techniques of measuring tissue pressure, which can prove invaluable in diagnosing the compartment syndrome.

  16. Acute exercise-induced bilateral thigh compartment syndrome.

    PubMed

    Boland, Michael R; Heck, Chris

    2009-03-01

    Acute compartment syndrome of the thigh is rare due to the space's ability to accommodate large volumes of fluid and, with the exception of the lateral septum, its thin compliant linings. This article describes a case of bilateral exercise-induced severe compartment syndrome treated with anterior and posterior fasciotomies. A 29-year-old man was admitted to intensive care with myoglobinuria. His left thigh was evaluated 18 hours later for compartment syndrome. The patient reported that 14 hours prior to initial presentation, he had participated in a 1-hour session of vigorous basketball. He gradually developed bilateral moderately severe thigh pain and tea-colored urine. Physical examination revealed pain secondary to passive stretch of both knees at 20 degrees flexion, plus firm anterior and posterior compartments to palpation. A handheld pressure monitor revealed the following compartment pressures: left anterior 80 mm Hg; left posterior 75 mm Hg; right anterior 45 mm Hg; and right posterior 50 mm Hg. Bilateral emergent anterior and posterior compartment fasciotomies were performed. The patient developed a significant severe distal motor and sensory neurological deficit on the left side, which recovered to 3/5 motor strength and protective sensation. At 6-month follow-up, he ambulated with the assistance of a left ankle foot orthosis. Acute severe compartment syndrome can occur following vigorous exercise. We recommend fasciotomies after exercise-induced acute compartment syndrome rather than initial observation because of the severity of morbidity associated with undertreated compartment syndrome.

  17. Compartment-specific antioxidative defense in Arabidopsis against virulent and avirulent Pseudomonas syringae.

    PubMed

    Großkinsky, Dominik K; Koffler, Barbara E; Roitsch, Thomas; Maier, Romana; Zechmann, Bernd

    2012-07-01

    The accumulation of reactive oxygen species (ROS) during biotic stress is either part of a hypersensitive response of the plant or induced directly by the pathogen. Antioxidants such as ascorbate and glutathione counteract the accumulation of ROS and are part of the defense reaction. The aim of the present study was to investigate the compartment-specific importance of ascorbate and glutathione during a virulent and avirulent Pseudomonas syringae infection in Arabidopsis thaliana. Peroxisomes were found to be the hotspot for glutathione accumulation reaching 452% and 258% of control levels 24 h postinoculation during the virulent and avirulent infection, respectively. An accumulation of ascorbate could also be observed in vacuoles during Pseudomonas syringae infection, whereas glutathione remained absent in this cell compartment. Neither glutathione nor ascorbate accumulated in the apoplast during pathogen infection demonstrating an only negligible role of these antioxidants in the apoplast during pathogen infection. Compartment-specific changes followed a recently proposed stress model with an increase of ascorbate and glutathione in most cell compartments at the early stages of infection and a strong drop at the later stage of infection when a strong accumulation of ROS and symptoms occurred in the leaves. This study highlights the importance of certain cell compartments and antioxidants in general for the protection of pathogen-induced ROS accumulation.

  18. Compartment-Specific Antioxidative Defense in Arabidopsis Against Virulent and Avirulent Pseudomonas syringae

    PubMed Central

    Großkinsky, Dominik K.; Koffler, Barbara E.; Roitsch, Thomas; Maier, Romana; Zechmann, Bernd

    2013-01-01

    The accumulation of reactive oxygen species (ROS) during biotic stress is either part of a hypersensitive response of the plant or induced directly by the pathogen. Antioxidants such as ascorbate and glutathione counteract the accumulation of ROS and are part of the defense reaction. The aim of the present study was to investigate the compartment-specific importance of ascorbate and glutathione during a virulent and avirulent Pseudomonas syringae infection in Arabidopsis thaliana. Peroxisomes were found to be the hotspot for glutathione accumulation reaching 452% and 258% of control levels 24 h postinoculation during the virulent and avirulent infection, respectively. An accumulation of ascorbate could also be observed in vacuoles during Pseudomonas syringae infection, whereas glutathione remained absent in this cell compartment. Neither glutathione nor ascorbate accumulated in the apoplast during pathogen infection demonstrating an only negligible role of these antioxidants in the apoplast during pathogen infection. Compartment-specific changes followed a recently proposed stress model with an increase of ascorbate and glutathione in most cell compartments at the early stages of infection and a strong drop at the later stage of infection when a strong accumulation of ROS and symptoms occurred in the leaves. This study highlights the importance of certain cell compartments and antioxidants in general for the protection of pathogen-induced ROS accumulation. PMID:22571419

  19. Spatial organization of chromatin domains and compartments in single chromosomes.

    PubMed

    Wang, Siyuan; Su, Jun-Han; Beliveau, Brian J; Bintu, Bogdan; Moffitt, Jeffrey R; Wu, Chao-ting; Zhuang, Xiaowei

    2016-08-05

    The spatial organization of chromatin critically affects genome function. Recent chromosome-conformation-capture studies have revealed topologically associating domains (TADs) as a conserved feature of chromatin organization, but how TADs are spatially organized in individual chromosomes remains unknown. Here, we developed an imaging method for mapping the spatial positions of numerous genomic regions along individual chromosomes and traced the positions of TADs in human interphase autosomes and X chromosomes. We observed that chromosome folding deviates from the ideal fractal-globule model at large length scales and that TADs are largely organized into two compartments spatially arranged in a polarized manner in individual chromosomes. Active and inactive X chromosomes adopt different folding and compartmentalization configurations. These results suggest that the spatial organization of chromatin domains can change in response to regulation.

  20. 14 CFR 23.1192 - Engine accessory compartment diaphragm.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Engine accessory compartment diaphragm. 23... Powerplant Powerplant Fire Protection § 23.1192 Engine accessory compartment diaphragm. For aircooled radial engines, the engine power section and all portions of the exhaust sytem must be isolated from the...

  1. 14 CFR 23.1192 - Engine accessory compartment diaphragm.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Engine accessory compartment diaphragm. 23... Powerplant Powerplant Fire Protection § 23.1192 Engine accessory compartment diaphragm. For aircooled radial engines, the engine power section and all portions of the exhaust sytem must be isolated from the...

  2. 14 CFR 25.855 - Cargo or baggage compartments.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Fire Protection § 25... attached to) the airplane structure. (c) Ceiling and sidewall liner panels of Class C compartments must.... (d) All other materials used in the construction of the cargo or baggage compartment must meet...

  3. 14 CFR 135.170 - Materials for compartment interiors.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Aircraft and Equipment § 135.170 Materials for compartment interiors. (a) No person may operate an airplane... 26, 1984. (c) Thermal/acoustic insulation materials. For transport category airplanes type... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Materials for compartment interiors....

  4. 14 CFR 135.170 - Materials for compartment interiors.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Aircraft and Equipment § 135.170 Materials for compartment interiors. (a) No person may operate an airplane... 26, 1984. (c) Thermal/acoustic insulation materials. For transport category airplanes type... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Materials for compartment interiors....

  5. 14 CFR 25.855 - Cargo or baggage compartments.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Fire Protection § 25... attached to) the airplane structure. (c) Ceiling and sidewall liner panels of Class C compartments must.... (d) All other materials used in the construction of the cargo or baggage compartment must meet...

  6. 14 CFR 135.170 - Materials for compartment interiors.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Aircraft and Equipment § 135.170 Materials for compartment interiors. (a) No person may operate an airplane... 26, 1984. (c) Thermal/acoustic insulation materials. For transport category airplanes type... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Materials for compartment interiors....

  7. 14 CFR 25.855 - Cargo or baggage compartments.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Fire Protection § 25... attached to) the airplane structure. (c) Ceiling and sidewall liner panels of Class C compartments must.... (d) All other materials used in the construction of the cargo or baggage compartment must meet...

  8. 14 CFR 23.1192 - Engine accessory compartment diaphragm.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Engine accessory compartment diaphragm. 23... Powerplant Powerplant Fire Protection § 23.1192 Engine accessory compartment diaphragm. For aircooled radial engines, the engine power section and all portions of the exhaust sytem must be isolated from the...

  9. 14 CFR 23.1192 - Engine accessory compartment diaphragm.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Engine accessory compartment diaphragm. 23... Powerplant Powerplant Fire Protection § 23.1192 Engine accessory compartment diaphragm. For aircooled radial engines, the engine power section and all portions of the exhaust sytem must be isolated from the...

  10. Acute compartment syndrome of the thigh after weight training.

    PubMed Central

    Bidwell, J P; Gibbons, C E; Godsiff, S

    1996-01-01

    Compartment syndrome of the thigh is a rare but serious condition that is normally associated with closed trauma or compressive injury. A case of acute compartment syndrome of the thigh occurred in a 16 year old boy after intensive weight training. There was no evidence of muscle tear or focal haemorrhage during subsequent fasciotomy. PMID:8889126

  11. Spontaneous Compartment Syndrome of the Hand in Systemic Sclerosis.

    PubMed

    Tanagho, Andy; Hatab, Sameh; Youssef, Sally; Ansara, Sameh

    2015-09-01

    Compartment syndrome refers to a condition of compromised circulation within a limited space due to increased pressure within that space. The reduced tissue perfusion results in reduced venous drainage, leading to increased interstitial tissue pressure and subsequent compromised arterial flow. Although not as common as compartment syndrome of the leg and forearm, compartment syndrome of the hand is not rare and can lead to devastating sequelae as a result of tissue necrosis. Compartment syndrome of the hand has several etiologies, including trauma, arterial injury, thermal injury, and constrictive bandaging. The cardinal clinical sign is pain that is aggravated by passive stretching of the muscles within the involved compartments. Extremity function is usually restored with expeditious fasciotomy of the involved myofascial compartments, and complications, such as intrinsic muscular dysfunction and Volkmann's ischemic contracture, can usually be prevented. There are no reported cases of compartment syndrome of the hand in patients with systemic sclerosis or Raynaud's phenomenon. Systemic sclerosis is a form of scleroderma that affects the skin and internal organs. The limited cutaneous subset affects the skin of the extremities but is associated with a set of characteristic features that includes calcinosis, Raynaud's phenomenon, esophageal involvement, sclerodactyly, and telangiectasia. This report describes an unusual case of a patient who had spontaneous compartment syndrome of the hand. The patient's concomitant limited cutaneous systemic sclerosis may have played a role in this unusual occurrence. The diagnosis was based on the clinical picture, and the symptoms resolved after surgical decompression.

  12. 14 CFR 25.772 - Pilot compartment doors.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Pilot compartment doors. 25.772 Section 25... § 25.772 Pilot compartment doors. For an airplane that has a lockable door installed between the pilot... passengers require use of the flightdeck door in order to reach the emergency exits provided for them; and...

  13. 14 CFR 25.772 - Pilot compartment doors.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Pilot compartment doors. 25.772 Section 25... § 25.772 Pilot compartment doors. For an airplane that has a lockable door installed between the pilot... passengers require use of the flightdeck door in order to reach the emergency exits provided for them; and...

  14. 49 CFR 179.220-9 - Compartment tanks.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Compartment tanks. 179.220-9 Section 179.220-9... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS SPECIFICATIONS FOR TANK CARS Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.220-9 Compartment tanks....

  15. 14 CFR 121.314 - Cargo and baggage compartments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... the certificate holder for operation under this part that has at least one Class D compartment that...: (a) Each Class C or Class D compartment, as defined in § 25.857 of this Chapter in effect on June 16... capability of the liner to safely contain a fire. (c) After March 19, 2001, each Class D...

  16. Contamination control of the space shuttle Orbiter crew compartment

    NASA Technical Reports Server (NTRS)

    Bartelson, Donald W.

    1986-01-01

    Effective contamination control as applied to manned space flight environments is a discipline characterized and controlled by many parameters. An introduction is given to issues involving Orbiter crew compartment contamination control. An effective ground processing contamination control program is an essential building block to a successful shuttle mission. Personnel are required to don cleanroom-grade clothing ensembles before entering the crew compartment and follow cleanroom rules and regulations. Prior to crew compartment entry, materials and equipment must be checked by an orbiter integrity clerk stationed outside the white-room entrance for compliance to program requirements. Analysis and source identification of crew compartment debris studies have been going on for two years. The objective of these studies is to determine and identify particulate generating materials and activities in the crew compartment. Results show a wide spectrum of many different types of materials. When source identification is made, corrective action is implemented to minimize or curtail further contaminate generation.

  17. Myosin-Powered Membrane Compartment Drives Cytoplasmic Streaming, Cell Expansion and Plant Development.

    PubMed

    Peremyslov, Valera V; Cole, Rex A; Fowler, John E; Dolja, Valerian V

    2015-01-01

    Using genetic approaches, particle image velocimetry and an inert tracer of cytoplasmic streaming, we have made a mechanistic connection between the motor proteins (myosins XI), cargo transported by these motors (distinct endomembrane compartment defined by membrane-anchored MyoB receptors) and the process of cytoplasmic streaming in plant cells. It is shown that the MyoB compartment in Nicotiana benthamiana is highly dynamic moving with the mean velocity of ~3 μm/sec. In contrast, Golgi, mitochondria, peroxisomes, carrier vesicles and a cytosol flow tracer share distinct velocity profile with mean velocities of 0.6-1.5 μm/sec. Dominant negative inhibition of the myosins XI or MyoB receptors using overexpression of the N. benthamiana myosin cargo-binding domain or MyoB myosin-binding domain, respectively, resulted in velocity reduction for not only the MyoB compartment, but also each of the tested organelles, vesicles and cytoplasmic streaming. Furthermore, the extents of this reduction were similar for each of these compartments suggesting that MyoB compartment plays primary role in cytosol dynamics. Using gene knockout analysis in Arabidopsis thaliana, it is demonstrated that inactivation of MyoB1-4 results in reduced velocity of mitochondria implying slower cytoplasmic streaming. It is also shown that myosins XI and MyoB receptors genetically interact to contribute to cell expansion, plant growth, morphogenesis and proper onset of flowering. These results support a model according to which myosin-dependent, MyoB receptor-mediated transport of a specialized membrane compartment that is conserved in all land plants drives cytoplasmic streaming that carries organelles and vesicles and facilitates cell growth and plant development.

  18. Myosin-Powered Membrane Compartment Drives Cytoplasmic Streaming, Cell Expansion and Plant Development

    PubMed Central

    Peremyslov, Valera V.; Cole, Rex A.; Fowler, John E.; Dolja, Valerian V.

    2015-01-01

    Using genetic approaches, particle image velocimetry and an inert tracer of cytoplasmic streaming, we have made a mechanistic connection between the motor proteins (myosins XI), cargo transported by these motors (distinct endomembrane compartment defined by membrane-anchored MyoB receptors) and the process of cytoplasmic streaming in plant cells. It is shown that the MyoB compartment in Nicotiana benthamiana is highly dynamic moving with the mean velocity of ~3 μm/sec. In contrast, Golgi, mitochondria, peroxisomes, carrier vesicles and a cytosol flow tracer share distinct velocity profile with mean velocities of 0.6–1.5 μm/sec. Dominant negative inhibition of the myosins XI or MyoB receptors using overexpression of the N. benthamiana myosin cargo-binding domain or MyoB myosin-binding domain, respectively, resulted in velocity reduction for not only the MyoB compartment, but also each of the tested organelles, vesicles and cytoplasmic streaming. Furthermore, the extents of this reduction were similar for each of these compartments suggesting that MyoB compartment plays primary role in cytosol dynamics. Using gene knockout analysis in Arabidopsis thaliana, it is demonstrated that inactivation of MyoB1-4 results in reduced velocity of mitochondria implying slower cytoplasmic streaming. It is also shown that myosins XI and MyoB receptors genetically interact to contribute to cell expansion, plant growth, morphogenesis and proper onset of flowering. These results support a model according to which myosin-dependent, MyoB receptor-mediated transport of a specialized membrane compartment that is conserved in all land plants drives cytoplasmic streaming that carries organelles and vesicles and facilitates cell growth and plant development. PMID:26426395

  19. Toxicokinetics of Metals in Terrestrial Invertebrates: Making Things Straight with the One-Compartment Principle

    PubMed Central

    Skip, Boris; Bednarska, Agnieszka J.; Laskowski, Ryszard

    2014-01-01

    In this analysis, we first performed a critical review of one-compartment models used to describe metal toxicokinetics in invertebrates and found mathematical or conceptual errors in almost all published studies. In some publications, the models used do not represent the exact solution of the underlying one-compartment differential equations; others use unrealistic assumptions about constant background metal concentration and/or zero metal concentration in uncontaminated medium. Herein we present exact solutions of two differential-equation models, one describing simple two-stage toxicokinetics (metal toxicokinetic follows the experimental phases: the uptake phase and the decontamination phase) and another that can be applied for more complex three-stage patterns (toxicokinetic pattern does not follow two phases determined by an experimenter). Using two case studies for carabids exposed via food, based on previously published data, we discuss and compare our models to those originally used to analyze the data. Our conclusion is that when metal toxicokinetic follows a one-compartment model, the exact solution of a set of differential equations should be used. The proposed models allow assimilation and elimination rates to change between toxicokinetic stages, and the three-stage model is flexible enough to fit patterns that are more complex than the classic two-stage model can handle. PMID:25268739

  20. Are hydrodynamic interactions screened in spherically confined micro-compartments?

    NASA Astrophysics Data System (ADS)

    Aponte-Rivera, Christian; Zia, Roseanna

    2016-11-01

    We study diffusion of hydrodynamically interacting particles confined by a spherical cavity via dynamic simulation, as a model for intracellular transport. Previous models of 3D confined transport typically assume that hydrodynamic interactions are screened and thus can be neglected, but such assumptions lead to qualitative errors in predictive models. Recent studies show that crowding does not screen hydrodynamic entrainment of freely diffusing particles in unbound suspensions, and that diffusing near a planar wall can weaken (but does not screen) hydrodynamic entrainment. Biophysical and other confined suspensions are crowded, watery compartments, suggesting a role of both crowding and confinement in hydrodynamic entrainment. In the present work, we utilize our new computational framework to study the effect of 3D micro-confinement on particle entrainment, and whether such entrainment is algebraically screened. We measure the hydrodynamic entrainment of one particle in the flow induced by another, in suspensions of arbitrary concentration. We find that the strength of entrainment varies spatially in the cavity, changes qualitatively with the size of the confined particles relative to the enclosure, but varies only quantitatively with the concentration of particles.

  1. Compartment Syndrome of the Calf Due to Nicolau Syndrome

    PubMed Central

    Enshaei, Ali; Afshar, Ahmadreza

    2016-01-01

    We report a case of Nicolau syndrome in a 15 months old girl following an intramuscular injection of penicillin 6.3.3 in her left buttock. This case is unique because she developed compartment syndrome in her left calf far from her injection site. Her toe’s tips gangrened in the course of her ailment. We hypothesized that the compartment syndrome might be produced by a probable intra-arterial injection that had produced embolic obstruction of the small and medium size arteries in her leg or a probable perineural or periarteial injection had produced secondary sympathetic stimulation, extensive vasospasm, compromised microcirculation and the development of compartment syndrome. PMID:26894227

  2. Compartment Syndrome of the Calf Due to Nicolau Syndrome.

    PubMed

    Enshaei, Ali; Afshar, Ahmadreza

    2016-01-01

    We report a case of Nicolau syndrome in a 15 months old girl following an intramuscular injection of penicillin 6.3.3 in her left buttock. This case is unique because she developed compartment syndrome in her left calf far from her injection site. Her toe's tips gangrened in the course of her ailment. We hypothesized that the compartment syndrome might be produced by a probable intra-arterial injection that had produced embolic obstruction of the small and medium size arteries in her leg or a probable perineural or periarteial injection had produced secondary sympathetic stimulation, extensive vasospasm, compromised microcirculation and the development of compartment syndrome.

  3. Dopamine modulated ionic permeability in mesoporous silica sphere based biomimetic compartment.

    PubMed

    Liu, Wei; Yang, Xiaohai; He, Dinggeng; He, Leiliang; Li, Li; Liu, Yu; Liu, Jianbo; Wang, Kemin

    2016-06-01

    The building of artificial systems with similar structure and function as cellular compartments will expand our understanding of compartmentalization related biological process and facilitate the construction of biomimetic highly functional structures. Herein, surface phenylboronic acid functionalized mesoporous silica sphere was developed as a biomimetic dopamine gated compartment, in which the ionic permeability can be well modulated through the dopamine-binding induced charge reversal. As the phenylboronic acid is negatively charged, the negatively charged 1, 3, 6, 8-pyrenetetrasulfonic acid (TPSA) was hindered from permeation into the biomimetic compartment. However, the presence of dopamine and its binding with phenylboronic acid reversed the gatekeeper shell from negative to positive charged and gated the permeation of TPSA into the interior. The dopamine gated permeation phenomenon resembles that in biological system, and thus the phenylboronic acid functionalized mesoporous silica sphere was taken as a simple model for dopamine gated ion channel decorated biological compartment. It will also contribute to the development of artificial cell and responsive nanoreactor.

  4. FEATURE 3, LARGE GUN POSITION, SHOWING MULTIPLE COMPARTMENTS, VIEW FACING ...

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

    FEATURE 3, LARGE GUN POSITION, SHOWING MULTIPLE COMPARTMENTS, VIEW FACING SOUTH. - Naval Air Station Barbers Point, Anti-Aircraft Battery Complex-Large Gun Position, East of Coral Sea Road, northwest of Hamilton Road, Ewa, Honolulu County, HI

  5. 7 CFR 58.510 - Rooms and compartments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ....510 Rooms and compartments. (a) Processing operations with open cheese vats should be separated from... ingredients supplies or finished products are handled, processed, packaged or stored shall be designed...

  6. 11. Interior view of communications compartment. View toward rear of ...

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

    11. Interior view of communications compartment. View toward rear of aircraft. - Offutt Air Force Base, Looking Glass Airborne Command Post, Looking Glass Aircraft, On Operational Apron covering northeast half of Project Looking Glass Historic District, Bellevue, Sarpy County, NE

  7. 10. Interior view of communications compartment. View toward front of ...

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

    10. Interior view of communications compartment. View toward front of aircraft. - Offutt Air Force Base, Looking Glass Airborne Command Post, Looking Glass Aircraft, On Operational Apron covering northeast half of Project Looking Glass Historic District, Bellevue, Sarpy County, NE

  8. 7 CFR 58.510 - Rooms and compartments.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... compartments shall be ventilated to maintain sanitary conditions, preclude the growth of mold and air borne... quality and condition of the products. Coolers shall be kept clean, orderly and free from mold,...

  9. 19 CFR 123.24 - Sealing of conveyances or compartments.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...; DEPARTMENT OF THE TREASURY CUSTOMS RELATIONS WITH CANADA AND MEXICO Shipments in Transit Through Canada or Mexico § 123.24 Sealing of conveyances or compartments. (a) Sealing required. Merchandise in...

  10. The pathophysiology, diagnosis and current management of acute compartment syndrome.

    PubMed

    Donaldson, James; Haddad, Behrooz; Khan, Wasim S

    2014-01-01

    Acute compartment syndrome (ACS) is a surgical emergency warranting prompt evaluation and treatment. It can occur with any elevation in interstitial pressure in a closed osseo-fascial compartment. Resultant ischaemic damage may be irreversible within six hours and can result in long-term morbidity and even death. The diagnosis is largely clinical with the classical description of 'pain out of proportion to the injury'. Compartment pressure monitors can be a helpful adjunct where the diagnosis is in doubt. Initial treatment is with the removal of any constricting dressings or casts, avoiding hypotension and optimizing tissue perfusion by keeping the limb at heart level. If symptoms persist, definitive treatment is necessary with timely surgical decompression of all the involved compartments. This article reviews the pathophysiology, diagnosis and current management of ACS.

  11. 2. INTERIOR, SOUTHWEST VIEW (STORAGE COMPARTMENTS). Vanadium Corporation of ...

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

    2. INTERIOR, SOUTHWEST VIEW (STORAGE COMPARTMENTS). - Vanadium Corporation of America (VCA) Naturita Mill, Mine Warehouse, 3 miles Northwest of Naturita, between Highway 141 & San Miguel River, Naturita, Montrose County, CO

  12. 14 CFR 23.787 - Baggage and cargo compartments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... inertial load factor is 9g and assuming the maximum allowed baggage or cargo weight for the compartment. (b... means to protect the occupants from injury when the baggage or cargo is subjected to the inertial...

  13. 14 CFR 23.787 - Baggage and cargo compartments.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... inertial load factor is 9g and assuming the maximum allowed baggage or cargo weight for the compartment. (b... means to protect the occupants from injury when the baggage or cargo is subjected to the inertial...

  14. 14 CFR 23.787 - Baggage and cargo compartments.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... inertial load factor is 9g and assuming the maximum allowed baggage or cargo weight for the compartment. (b... means to protect the occupants from injury when the baggage or cargo is subjected to the inertial...

  15. 14 CFR 23.787 - Baggage and cargo compartments.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... inertial load factor is 9g and assuming the maximum allowed baggage or cargo weight for the compartment. (b... means to protect the occupants from injury when the baggage or cargo is subjected to the inertial...

  16. 14 CFR 23.787 - Baggage and cargo compartments.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... inertial load factor is 9g and assuming the maximum allowed baggage or cargo weight for the compartment. (b... means to protect the occupants from injury when the baggage or cargo is subjected to the inertial...

  17. Compartment pressure monitoring during anterior cruciate ligament reconstruction.

    PubMed

    Amendola, A; Faber, K; Willits, K; Miniaci, A; Labib, S; Fowler, P

    1999-09-01

    A prospective double blind randomized study was carried out using 20 healthy males with anterior cruciate ligament (ACL) insufficiency undergoing bone-patellar tendon-bone ACL reconstruction. The subjects were randomized into either water or saline irrigation and then underwent identical reconstructive procedures using an arthroscopic pump. Continuous preoperative, intraoperative, and postoperative pressures were monitored using the slit catheter technique. Blood pressure and compartment pressure measurements were continuously recorded and noted at all stages of the procedure. Mean preoperative anterior and posterior compartment pressures were similar in both groups. No significant differences were noted between the anterior and posterior compartments of each group. No difference between water and saline irrigation was identified throughout the procedure. In both groups, postoperative pressures were slightly lower in the anterior and posterior compartments compared with preoperative pressures, but not significantly.

  18. 9. Interior view of electronics compartment. View toward rear of ...

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

    9. Interior view of electronics compartment. View toward rear of aircraft. - Offutt Air Force Base, Looking Glass Airborne Command Post, Looking Glass Aircraft, On Operational Apron covering northeast half of Project Looking Glass Historic District, Bellevue, Sarpy County, NE

  19. Dynamics of the Establishment of Multinucleate Compartments in Fusarium oxysporum

    PubMed Central

    Shahi, Shermineh; Beerens, Bas; Manders, Erik M. M.

    2014-01-01

    Nuclear dynamics can vary widely between fungal species and between stages of development of fungal colonies. Here we compared nuclear dynamics and mitotic patterns between germlings and mature hyphae in Fusarium oxysporum. Using fluorescently labeled nuclei and live-cell imaging, we show that F. oxysporum is subject to a developmental transition from a uninucleate to a multinucleate state after completion of colony initiation. We observed a special type of hypha that exhibits a higher growth rate, possibly acting as a nutrient scout. The higher growth rate is associated with a higher nuclear count and mitotic waves involving 2 to 6 nuclei in the apical compartment. Further, we found that dormant nuclei of intercalary compartments can reenter the mitotic cycle, resulting in multinucleate compartments with up to 18 nuclei in a single compartment. PMID:25398376

  20. Diagnosis of Compartment Syndrome Based on Tissue Oxygenation

    DTIC Science & Technology

    2015-06-01

    tissue oxygenation and compartment pressure following tibia fracture, Injury 2013, 44:1076- 1080 8. Cathcart CC, Shuler MS, Freedman BA, Reno LR...Injury, Int. J. Care Injured 44 (2013) 1076– 1080 1077percentage of postoperative CP measurements would meet established warning criteria for compartment...Care Injured 44 (2013) 1076– 1080 1079in one patient. Correlations between PmO2 and CP excluding the first 3 h resulted in Pearson correlation

  1. Contralateral compartment syndrome inoculated by invasive group A streptococcus

    PubMed Central

    Chen, Huiwen; Mcphillips, Sean Thomas; Chundi, Vishnu

    2016-01-01

    Compartment syndrome is a rare but a well-documented complication in patients with trauma-induced group A streptococcus infection. Here, we present a case of a male who developed compartment syndrome on the left lower extremity after an injury inoculated by group A streptococcus on the right lower extremity. The patient was resuscitated with antibiotics, urgent fasciotomy, and immunoglobulin. The patient was eventually transferred to a burn center for further care. PMID:27802865

  2. Differential gene expression in anatomical compartments of the human eye

    PubMed Central

    Diehn, Jennifer J; Diehn, Maximilian; Marmor, Michael F; Brown, Patrick O

    2005-01-01

    Background The human eye is composed of multiple compartments, diverse in form, function, and embryologic origin, that work in concert to provide us with our sense of sight. We set out to systematically characterize the global gene expression patterns that specify the distinctive characteristics of the various eye compartments. Results We used DNA microarrays representing approximately 30,000 human genes to analyze gene expression in the cornea, lens, iris, ciliary body, retina, and optic nerve. The distinctive patterns of expression in each compartment could be interpreted in relation to the physiology and cellular composition of each tissue. Notably, the sets of genes selectively expressed in the retina and in the lens were particularly large and diverse. Genes with roles in immune defense, particularly complement components, were expressed at especially high levels in the anterior segment tissues. We also found consistent differences between the gene expression patterns of the macula and peripheral retina, paralleling the differences in cell layer densities between these regions. Based on the hypothesis that genes responsible for diseases that affect a particular eye compartment are likely to be selectively expressed in that compartment, we compared our gene expression signatures with genetic mapping studies to identify candidate genes for diseases affecting the cornea, lens, and retina. Conclusion Through genome-scale gene expression profiling, we were able to discover distinct gene expression 'signatures' for each eye compartment and identified candidate disease genes that can serve as a reference database for investigating the physiology and pathophysiology of the eye. PMID:16168081

  3. Modulatory compartments in cortex and local regulation of cholinergic tone.

    PubMed

    Coppola, Jennifer J; Ward, Nicholas J; Jadi, Monika P; Disney, Anita A

    2016-09-01

    Neuromodulatory signaling is generally considered broad in its impact across cortex. However, variations in the characteristics of cortical circuits may introduce regionally-specific responses to diffuse modulatory signals. Features such as patterns of axonal innervation, tissue tortuosity and molecular diffusion, effectiveness of degradation pathways, subcellular receptor localization, and patterns of receptor expression can lead to local modification of modulatory inputs. We propose that modulatory compartments exist in cortex and can be defined by variation in structural features of local circuits. Further, we argue that these compartments are responsible for local regulation of neuromodulatory tone. For the cholinergic system, these modulatory compartments are regions of cortical tissue within which signaling conditions for acetylcholine are relatively uniform, but between which signaling can vary profoundly. In the visual system, evidence for the existence of compartments indicates that cholinergic modulation likely differs across the visual pathway. We argue that the existence of these compartments calls for thinking about cholinergic modulation in terms of finer-grained control of local cortical circuits than is implied by the traditional view of this system as a diffuse modulator. Further, an understanding of modulatory compartments provides an opportunity to better understand and perhaps correct signal modifications that lead to pathological states.

  4. Structure and Function of the Perinucleolar Compartment in Cancer Cells

    PubMed Central

    Slusarczyk, A.; Kamath, R.; Wang, C.; Anchel, D.; Pollock, C.; Lewandowska, M.A.; Fitzpatrick, T.; Bazett-Jones, D.P.; Huang, S.

    2014-01-01

    The perinucleolar compartment (PNC) is a subnuclear body that forms in cancer cells. In vivo analyses using human tumor tissues demonstrate a close correlation between PNC prevalence and disease progress in colorectal carcinoma, and a high PNC prevalence is associated with poor patient outcome. These findings are consistent with previous observations in breast cancer and cancer cell lines in vitro. The PNC is composed of thick strands that form a filamental meshwork often extending into the nucleolus. Although it appears to be electron dense as observed by transmission electron microscopy (TEM), the actual density of the structure imaged by electron spectroscopy is much lower, similar to that of the interchromatin space, and is lined with ribonucleoproteins (RNPs). In situ detections show that the PNC is highly enriched with a subset of small RNAs of polymerase III (Pol III) origins and RNA-binding proteins primarily implicated in pre-mRNA processing. A novel gel-shifting approach demonstrates that the addition of PNC-associated RNAs into HeLa cell lysates increases the mobility of polypyrimidine tract-binding (PTB) protein in a native gel electrophoresis, suggesting an interaction between these RNAs and PTB proteins. On the basis of these and other findings, we propose a working model in which novel RNPs have a key role in regulating gene expression at the PNC in cancer cells. PMID:21289045

  5. Prelysosomal Compartments in the Unconventional Secretion of Amyloidogenic Seeds

    PubMed Central

    Borland, Helena; Vilhardt, Frederik

    2017-01-01

    A mechanistic link between neuron-to-neuron transmission of secreted amyloid and propagation of protein malconformation cytopathology and disease has recently been uncovered in animal models. An enormous interest in the unconventional secretion of amyloids from neurons has followed. Amphisomes and late endosomes are the penultimate maturation products of the autophagosomal and endosomal pathways, respectively, and normally fuse with lysosomes for degradation. However, under conditions of perturbed membrane trafficking and/or lysosomal deficiency, prelysosomal compartments may instead fuse with the plasma membrane to release any contained amyloid. After a brief introduction to the endosomal and autophagosomal pathways, we discuss the evidence for autophagosomal secretion (exophagy) of amyloids, with a comparative emphasis on Aβ1–42 and α-synuclein, as luminal and cytosolic amyloids, respectively. The ESCRT-mediated import of cytosolic amyloid into late endosomal exosomes, a known vehicle of transmission of macromolecules between cells, is also reviewed. Finally, mechanisms of lysosomal dysfunction, deficiency, and exocytosis are exemplified in the context of genetically identified risk factors, mainly for Parkinson’s disease. Exocytosis of prelysosomal or lysosomal organelles is a last resort for clearance of cytotoxic material and alleviates cytopathy. However, they also represent a vehicle for the concentration, posttranslational modification, and secretion of amyloid seeds. PMID:28124989

  6. Electrical Dissipative Structures in Membrane-Coupled Compartment Systems

    NASA Astrophysics Data System (ADS)

    Feudel, U.; Feistel, R.; Ebeling, W.

    Reaction-diffusion systems with charged particles are studied. Conditions for the arising of electrical dissipative structures in a compartment system consisting of two boxes separated by a membrane are derived. The appearance of a polar dissipative structure is proved for a simple capacitor model in combination with a simple second order chemical kinetics which leads to an analytically solvable problem. Electrical dissipative structures can in principle be considered as non equilibrium electrical batteries. The theoretical efficiency of such batteries is estimated.Translated AbstractElektrische Dissipative Strukturen in Membrangekoppelten SystemenEs werden Reaktions-Diffusionssysteme mit geladenen Teilchen studiert. Bedingungen für die Entstehung elektrischer dissipativer Strukturen in einem Kompartment-System, bestehend aus zwei durch eine Membran getrennten Zellen werden abgeleitet. Die Entstehung einer polaren dissipativen Struktur wird für ein einfaches Kondensatorenmodell in Kombination mit einer einfachen chemischen Kinetik, das analytische Lösbarkeit gestattet, nachgewiesen. Elektrische dissipative Strukturen können im Prinzip als elektrische Batterien fern von Gleichgewicht betrachtet werden. Der theoretische Wirkungsgrad einer solchen Batterie wird berechnet.

  7. MELiSSA third compartment: Nitrosomonas europaea and Nitrobacter winogradskyi axenic cultures in bioreactors

    NASA Astrophysics Data System (ADS)

    Cruvellier, Nelly; Lasseur, Christophe; Poughon, Laurent; Creuly, Catherine; Dussap, Gilles

    Nitrogen is a key element for the life and its balance on Earth is regulated by the nitrogen cycle. This loop includes several steps among which nitrification that permits the transformation of the ammonium into nitrate. The MELiSSA loop is an artificial ecosystem designed for life support systems (LSS). It is based on the carbon and nitrogen cycles and the recycling of the non-edible part of the higher plants and the waste produced by the crew. In this order, all the wastes are collected in the first compartment to degrade them into organic acids and CO2. These compounds are joining the second compartment which is a photoheterotrophic compartment where at the outlet an organic-free medium containing ammonium is produced. This solution will be the substrate of the third compartment where nitrification is done. This compartment has to oxidize the ammonium into nitrate, and this biological reaction needs two steps. In the MELiSSA loop, the nitrification is carried out by two bacteria: Nitrosomonas europaea ATCC® 19718™ which is oxidizing ammonia into nitrite and Nitrobacter winogradskyi ATCC® 25391™ which is producing nitrate from nitrite in the third compartment. These two bacteria are growing in axenic conditions on a fixed bed bioreactor filled with Biostyr® beads. The nitrogen compounds are controlled by Ionic Chromatography and colorimetric titration for each sample. The work presented here deals with the culture of both bacteria in pure cultures and mixed cultures in stirred and aerated bioreactors of different volumes. The first aim of our work is the characterization of the bacteria growth in bioreactors and in the nitrifying fixed-bed column. The experimental results confirm that the growth is slow; the maximal growth rate in suspended cultures is 0.054h-1 for Nitrosomonas europaea and 0.022h-1 for Nitrobacter winogradskyi. Mixed cultures are difficult to control and operate but one could be done for more than 500 hours. The characterization of the

  8. Telavancin demonstrates activity against methicillin-resistant Staphylococcus aureus isolates with reduced susceptibility to vancomycin, daptomycin, and linezolid in broth microdilution MIC and one-compartment pharmacokinetic/pharmacodynamic models.

    PubMed

    Smith, Jordan R; Barber, Katie E; Hallesy, Jessica; Raut, Animesh; Rybak, Michael J

    2015-09-01

    Methicillin-resistant Staphylococcus aureus (MRSA) isolates have arisen with reduced susceptibility to several anti-MRSA agents. Telavancin (TLV), a novel anti-MRSA agent, retains low MICs against these organisms. Our objective was to determine the MICs for TLV, daptomycin (DAP), vancomycin (VAN), and linezolid (LZD) against daptomycin-nonsusceptible (DNS) S. aureus, vancomycin-intermediate S. aureus (VISA), heteroresistant VISA (hVISA), and linezolid-resistant (LZD(r)) S. aureus. We also evaluated these agents against each phenotype in pharmacokinetic/pharmacodynamic (PK/PD) models. Seventy DNS, 100 VISA, 180 hVISA, and 25 LZD(r) MRSA isolates were randomly selected from our library and tested to determine their MICs against TLV, DAP, VAN, and LZD via broth microdilution and a Trek panel. Four isolates were randomly selected for 168-h in vitro models to evaluate treatment with TLV at 10 mg/kg of body weight/day, DAP at 10 mg/kg/day, VAN at 1 g every 12 h (q12h), and LZD at 600 mg q12h. The MIC50/90 for TLV, DAP, VAN, and LZD against 70 DNS S. aureus isolates were 0.06/0.125 μg/ml, 2/4 μg/ml, 1/2 μg/ml, and 2/2 μg/ml, respectively. Against 100 VISA isolates, the MIC50/90 were 0.06/0.125 μg/ml, 1/1 μg/ml, 4/8 μg/ml, and 1/2 μg/ml, respectively. Against 170 hVISA isolates, the MIC50/90 were 0.06/0.125 μg/ml, 0.5/1 μg/ml, 1/2 μg/ml, and 1/2 μg/ml, respectively. Against 25 LZD(r) isolates, the MIC50/90 were 0.03/0.06 μg/ml, 1/1 μg/ml, 2/2 μg/ml, and 8/8 μg/ml, respectively. The TLV MIC was >0.125 μg/ml for 10/365 (2.7%) isolates. In PK/PD models, TLV was universally bactericidal at 168 h and statistically superior to all antibiotics against DNS S. aureus strain R2334. These data further establish the potency of TLV against resistant MRSA. The model data demonstrate in vitro bactericidal activity of TLV against hVISA, VISA, DNS S. aureus, and LZD(r) S. aureus strains. Further clinical research is warranted.

  9. Telavancin Demonstrates Activity against Methicillin-Resistant Staphylococcus aureus Isolates with Reduced Susceptibility to Vancomycin, Daptomycin, and Linezolid in Broth Microdilution MIC and One-Compartment Pharmacokinetic/Pharmacodynamic Models

    PubMed Central

    Smith, Jordan R.; Barber, Katie E.; Hallesy, Jessica; Raut, Animesh

    2015-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) isolates have arisen with reduced susceptibility to several anti-MRSA agents. Telavancin (TLV), a novel anti-MRSA agent, retains low MICs against these organisms. Our objective was to determine the MICs for TLV, daptomycin (DAP), vancomycin (VAN), and linezolid (LZD) against daptomycin-nonsusceptible (DNS) S. aureus, vancomycin-intermediate S. aureus (VISA), heteroresistant VISA (hVISA), and linezolid-resistant (LZDr) S. aureus. We also evaluated these agents against each phenotype in pharmacokinetic/pharmacodynamic (PK/PD) models. Seventy DNS, 100 VISA, 180 hVISA, and 25 LZDr MRSA isolates were randomly selected from our library and tested to determine their MICs against TLV, DAP, VAN, and LZD via broth microdilution and a Trek panel. Four isolates were randomly selected for 168-h in vitro models to evaluate treatment with TLV at 10 mg/kg of body weight/day, DAP at 10 mg/kg/day, VAN at 1 g every 12 h (q12h), and LZD at 600 mg q12h. The MIC50/90 for TLV, DAP, VAN, and LZD against 70 DNS S. aureus isolates were 0.06/0.125 μg/ml, 2/4 μg/ml, 1/2 μg/ml, and 2/2 μg/ml, respectively. Against 100 VISA isolates, the MIC50/90 were 0.06/0.125 μg/ml, 1/1 μg/ml, 4/8 μg/ml, and 1/2 μg/ml, respectively. Against 170 hVISA isolates, the MIC50/90 were 0.06/0.125 μg/ml, 0.5/1 μg/ml, 1/2 μg/ml, and 1/2 μg/ml, respectively. Against 25 LZDr isolates, the MIC50/90 were 0.03/0.06 μg/ml, 1/1 μg/ml, 2/2 μg/ml, and 8/8 μg/ml, respectively. The TLV MIC was >0.125 μg/ml for 10/365 (2.7%) isolates. In PK/PD models, TLV was universally bactericidal at 168 h and statistically superior to all antibiotics against DNS S. aureus strain R2334. These data further establish the potency of TLV against resistant MRSA. The model data demonstrate in vitro bactericidal activity of TLV against hVISA, VISA, DNS S. aureus, and LZDr S. aureus strains. Further clinical research is warranted. PMID:26124162

  10. Calculation of the relative metastabilities of proteins in subcellular compartments of Saccharomyces cerevisiae

    PubMed Central

    Dick, Jeffrey M

    2009-01-01

    Background Protein subcellular localization and differences in oxidation state between subcellular compartments are two well-studied features of the the cellular organization of S. cerevisiae (yeast). Theories about the origin of subcellular organization are assisted by computational models that can integrate data from observations of compositional and chemical properties of the system. Presentation and implications of the hypothesis I adopt the hypothesis that the state of yeast subcellular organization is in a local energy minimum. This hypothesis implies that equilibrium thermodynamic models can yield predictions about the interdependence between populations of proteins and their subcellular chemical environments. Testing the hypothesis Three types of tests are proposed. First, there should be correlations between modeled and observed oxidation states for different compartments. Second, there should be a correspondence between the energy requirements of protein formation and the order the appearance of organelles during cellular development. Third, there should be correlations between the predicted and observed relative abundances of interacting proteins within compartments. Results The relative metastability fields of subcellular homologs of glutaredoxin and thioredoxin indicate a trend from less to more oxidizing as mitochondrion – cytoplasm – nucleus. Representing the overall amino acid compositions of proteins in 23 different compartments each with a single reference model protein suggests that the formation reactions for proteins in the vacuole (in relatively oxidizing conditions), ER and early Golgi (in relatively reducing conditions) are relatively highly favored, while that for the microtubule is the most costly. The relative abundances of model proteins for each compartment inferred from experimental data were found in some cases to correlate with the predicted abundances, and both positive and negative correlations were found for some assemblages

  11. 77 FR 19148 - Special Conditions: Airbus, A350-900 Series Airplane; Crew Rest Compartments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-30

    ...-900 Series Airplane; Crew Rest Compartments AGENCY: Federal Aviation Administration (FAA), DOT. ACTION... separate Crew Rest Compartments: a Flight Crew Rest Compartment (FCRC) intended to be occupied by flight crew members only, and a Cabin Crew Rest Compartment (CCRC) intended to be occupied by cabin...

  12. Psittacine paranasal sinus--a new definition of compartments.

    PubMed

    Artmann, A; Henninger, W

    2001-12-01

    Documentation of the psittacine paranasal sinuses has been limited. To provide more published detail, spiral computed tomography (CT) was used to scan the cephalic and cervical region from cadavers of 10 psittacine birds (Ara ararauna, Ara chloroptera, Ara macao, and Anodorhynchus hyacinthinus). Skeletal studies, histologic examinations, and evaluation of deep-frozen sections and anatomic preparations confirmed the results of the CT scans. New morphologic details of the paranasal sinus and some compartments were discovered. The paranasal sinuses of these macaws consist of two unpaired rostral compartments, followed caudally by eight paired compartments. Histologic examinations revealed that the walls of the paranasal sinuses consist of flat or cubic monolayer epithelium with underlying connective tissue. The described method of CT examination of these macaws, especially the positioning, scan orientation and parameters, and documentation of the normal paranasal sinus, provides a basis for future clinical use of CT.

  13. Hypothyroid-induced acute compartment syndrome in all extremities

    PubMed Central

    Musielak, Matthew C.; Chae, Jung Hee

    2016-01-01

    Acute compartment syndrome (ACS) is an uncommon complication of uncontrolled hypothyroidism. If unrecognized, this can lead to ischemia, necrosis and potential limb loss. A 49-year-old female presented with the sudden onset of bilateral lower and upper extremity swelling and pain. The lower extremity anterior compartments were painful and tense. The extensor surface of the upper extremities exhibited swelling and pain. Motor function was intact, however, limited due to pain. Bilateral lower extremity fasciotomies were performed. Postoperative Day 1, upper extremity motor function decreased significantly and paresthesias occurred. She therefore underwent bilateral forearm fasciotomies. The pathogenesis of hypothyroidism-induced compartment syndrome is unclear. Thyroid-stimulating hormone-induced fibroblast activation results in increased glycosaminoglycan deposition. The primary glycosaminoglycan in hypothyroid myxedematous changes is hyaluronic acid, which binds water causing edema. This increases vascular permeability, extravasation of proteins and impaired lymphatic drainage. These contribute to increased intra-compartmental pressure and subsequent ACS. PMID:28003319

  14. Fire safety evaluation of aircraft lavatory and cargo compartments

    NASA Technical Reports Server (NTRS)

    Kourtides, D. A.; Parker, J. A.; Hilado, C. J.; Anderson, R. A.; Tustin, E.; Arnold, D. E.; Gaume, J. G.; Binding, A. T.; Mikeska, J. L.

    1975-01-01

    Large-scale aircraft lavatory and cargo compartment fire tests are described. Tests were conducted to evaluate the effectiveness of these compartments to contain fire and smoke. Two tests were conducted and are detailed. Test 1 involved a production Boeing 747 lavatory of the latest design installed in an enclosure outside the aircraft, to collect gases and expose animals to these gases. Results indicate that the interior of the lavatory was completely burned, evolving smoke and combustion products in the enclosure. Test 2 involved a simulated Douglas DC-10 cargo compartment retro-fitted with standard fiberglass liner. The fire caused excessive damage to the liner and burned through the ceiling in two areas. Test objectives, methods, materials, and results are presented and discussed.

  15. A total and biosafe liquefaction compartment for MELiSSA

    NASA Astrophysics Data System (ADS)

    Verstraete, W.; Albrecht, T.; Kübe, J.; Dussap, G.; Creuly, C.

    2005-10-01

    Envisaging long-duration space missions and settlements on the Moon or even on more distant planets means considering the production of food and the recycling of scarce, valuable chemical species from waste. ESA's MELiSSA project (Micro-Ecological Life Support System Alternative) is studying, in which five different compartments degrade waste into basic chemicals and then assimilate them into food, clean water and a breathable atmosphere. Crucial to the success of such a closed system is the absolute efficiency of the first compartment, in which all waste is biologically degraded into easily assimilable basic compounds. In order to ease this strenuous task and to ensure total and biosafe liquefaction of the waste, this MAP project is studying additional technologies that complement MELiSSA's waste degrading compartment.

  16. Pressurization of a compartment due to the rupture of coolant piping

    SciTech Connect

    Kot, C.A.; Hsieh, B.J.

    1993-01-01

    The pressurization and venting of enclosed compartments due to the accidental rupture of coolant piping is a safety problem common to many nuclear facilities. The processes associated with such an accident are very complex, involving, in general, transient multiphase flows, interactions and mixing between the incoming flows and the gases in the compartment, and heat transfer with the surroundings. Since pipe rupture is associated with many phenomenological uncertainties, elaborate 3-D thermal-hydraulic modeling and extensive calculational efforts are not warranted for many design applications. It is then more appropriate to rely. on simplified, global analysis approaches which can provide reasonably conservative estimates of the structural loads and flow processes, and which can readily be used in parameter/design studies. The objective of this paper is to present such an approach.

  17. Posterior Compartment Anatomy as seen in MRI and 3-D Reconstruction from Asymptomatic Nulliparas

    PubMed Central

    HSU, Yvonne; LEWICKY-GAUPP, Christina; De LANCEY, John O.L.

    2010-01-01

    Objective To identify characteristic anatomical features of the posterior compartment using MR cross-sectional anatomy and 3-D modeling. Study Design Supine, static proton-density MR images of 20 nulliparas were analyzed. MR images were used to create models in a selected exemplar. Results The compartment’s upper, mid, and lower segments are best seen in the axial plane. It is bounded inferiorly by the perineal body, ventrally by the posterior vaginal wall and dorsally by the levator ani muscles and coccyx. In the upper portion, the compartment is bordered laterally by the uterosacral ligaments while in the mid portion, there is more direct contact with the lateral levator ani muscles. In the lower portion, the contact becomes obliterated as the vagina and levator ani muscles become fused to one another and to the perineal body. Conclusion The posterior compartment has characteristic anatomic features in MR cross-sectional anatomy that can be further elucidated and integrated with 3-D anatomy. PMID:18241813

  18. A theory of synchrony for active compartments with delays coupled through bulk diffusion

    NASA Astrophysics Data System (ADS)

    Xu, Bin; Bressloff, Paul C.

    2017-02-01

    We extend recent work on the analysis of synchronization in a pair of biochemical oscillators coupled by linear bulk diffusion, in order to explore the effects of discrete delays. More specifically, we consider two well-mixed, identical compartments located at either end of a bounded, one-dimensional domain. The compartments can exchange signaling molecules with the bulk domain, within which the signaling molecules undergo diffusion. The concentration of signaling molecules in each compartment is modeled by a delay differential equation (DDE), while the concentration in the bulk medium is modeled by a partial differential equation (PDE) for diffusion. Coupling in the resulting PDE-DDE system is via flux terms at the boundaries. Using linear stability analysis, numerical simulations and bifurcation analysis, we investigate the effect of diffusion on the onset of a supercritical Hopf bifurcation. The direction of the Hopf bifurcation is determined by numerical simulations and a winding number argument. Near a Hopf bifurcation point, we find that there are oscillations with two possible modes: in-phase and anti-phase. Moreover, the critical delay for oscillations to occur increases with the diffusion coefficient. Our numerical results suggest that the selection of the in-phase or anti-phase oscillation is sensitive to the diffusion coefficient, time delay and coupling strength. For slow diffusion and weak coupling both modes can coexist, while for fast diffusion and strong coupling, only one of the modes is dominant, depending on the explicit choice of DDE.

  19. Superior Mesenteric Artery Syndrome with Abdominal Compartment Syndrome

    PubMed Central

    Reece, Kevin; Day, Rachel

    2016-01-01

    Superior Mesenteric Artery (SMA) syndrome is a condition in which the duodenum becomes compressed between the SMA and the aorta, resulting in bowel obstruction which subsequently compresses surrounding structures. Pressure on the inferior vena cava (IVC) and aorta decreases cardiac output which compromises distal blood flow, resulting in abdominal compartment syndrome with ischemia and renal failure. A 15-year-old male with SMA syndrome presented with 12 hours of pain, a distended, rigid abdomen, mottled skin below the waist, and decreased motor and sensory function in the lower extremities. Exploratory laparotomy revealed ischemic small bowel and stomach with abdominal compartment syndrome. Despite decompression, the patient arrested from hyperkalemia following reperfusion. PMID:28003918

  20. Metabolic reprogramming and two-compartment tumor metabolism

    PubMed Central

    Chiavarina, Barbara; Martinez-Outschoorn, Ubaldo E.; Whitaker-Menezes, Diana; Howell, Anthony; Tanowitz, Herbert B.; Pestell, Richard G.; Sotgia, Federica; Lisanti, Michael P.

    2012-01-01

    Hypoxia-inducible factor (HIF) 1α and 2α are transcription factors responsible for the cellular response to hypoxia. The functional roles of HIF1α and HIF2α in cancer are distinct and vary among different tumor types. The aim of this study was to evaluate the compartment-specific role(s) of HIF1α and HIF2α in breast cancer. To this end, immortalized human fibroblasts and MDA-MB-231 breast cancer cells carrying constitutively active HIF1α or HIF2α mutants were analyzed with respect to their metabolic function(s) and ability to promote tumor growth in an in vivo setting. We observed that activation of HIF1α, but not HIF2α, in stromal cells promotes a shift toward aerobic glycolysis, with increased L-lactate production and a loss of mitochondrial activity. In a xenograft model, HIF1α-activated fibroblasts promoted the tumor growth of co-injected MDA-MB-231 cells without an increase in angiogenesis. Conversely, HIF2α-activated stromal cells did not favor tumor growth and behaved as the empty vector controls. Similarly, activation of HIF1α, but not HIF2α, in MDA-MB-231 cells promoted a shift toward aerobic glycolysis, with increased glucose uptake and L-lactate production. In contrast, HIF2α activation in cancer cells increased the expression of EGFR, Ras and cyclin D1, which are known markers of tumor growth and cell cycle progression. In a xenograft model, HIF1α activation in MDA-MB-231 cells acted as a tumor suppressor, resulting in an almost 2-fold reduction in tumor mass and volume. Interestingly, HIF2α activation in MDA-MB-231 cells induced a significant ~2-fold-increase in tumor mass and volume. Analysis of mitochondrial activity in these tumor xenografts using COX (cytochrome C oxidase) staining demonstrated elevated mitochondrial oxidative metabolism (OXPHOS) in HIF2α-tumors. We conclude that the role(s) of HIF1α and HIF2α in tumorigenesis are compartment-specific. HIF1α acts as a tumor promoter in stromal cells but as a tumor suppressor in

  1. FEATURE 3, LARGE GUN POSITION, SHOWING MULTIPLE COMPARTMENTS, VIEW FACING ...

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

    FEATURE 3, LARGE GUN POSITION, SHOWING MULTIPLE COMPARTMENTS, VIEW FACING SOUTH (with scale stick). - Naval Air Station Barbers Point, Anti-Aircraft Battery Complex-Large Gun Position, East of Coral Sea Road, northwest of Hamilton Road, Ewa, Honolulu County, HI

  2. Gluteal Compartment Syndrome following an Iliac Bone Marrow Aspiration

    PubMed Central

    Vega-Najera, Carlos; Leal-Contreras, Carlos; Leal-Berumen, Irene

    2013-01-01

    The compartment syndrome is a condition characterized by a raised hydraulic pressure within a closed and non expandable anatomical space. It leads to a vascular insufficiency that becomes critical once the vascular flow cannot return the fluids back to the venous system. This causes a potential irreversible damage of the contents of the compartment, especially within the muscle tissues. Gluteal compartment syndrome (GCS) secondary to hematomas is seldom reported. Here we present a case of a 51-year-old patient with history of a non-Hodgkin lymphoma who underwent a bone marrow aspiration from the posterior iliac crest that had excessive bleeding at the puncture zone. The patient complained of increasing pain, tenderness, and buttock swelling. Intraoperative pressure validation of the gluteal compartment was performed, and a GCS was diagnosed. The patient was treated with a gluteal region fasciotomy. The patient recovered from pain and swelling and was discharged shortly after from the hospital. We believe clotting and hematologic disorders are a primary risk factor in patients who require bone marrow aspirations or biopsies. It is important to improve awareness of GCS in order to achieve early diagnosis, avoid complications, and have a better prognosis. PMID:24392235

  3. 14 CFR 91.613 - Materials for compartment interiors.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... materials. For transport category airplanes type certificated after January 1, 1958: (1) For airplanes... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Materials for compartment interiors. 91.613... and Operating Requirements for Large and Transport Category Aircraft § 91.613 Materials...

  4. 14 CFR 23.853 - Passenger and crew compartment interiors.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... breakage or failure of such an item would not create a hazard. (f) Airplane materials located on the cabin... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES... compartment to be used by the crew or passengers: (a) The materials must be at least flame-resistant; (b)...

  5. 14 CFR 91.613 - Materials for compartment interiors.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... materials. For transport category airplanes type certificated after January 1, 1958: (1) For airplanes... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Materials for compartment interiors. 91.613... and Operating Requirements for Large and Transport Category Aircraft § 91.613 Materials...

  6. 14 CFR 121.314 - Cargo and baggage compartments.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... and baggage compartments. For each transport category airplane type certificated after January 1, 1958... sidewall liner panels which are constructed of: (1) Glass fiber reinforced resin; (2) Materials which meet... number of each airplane listed in the operations specifications issued to the certificate holder...

  7. 14 CFR 121.312 - Materials for compartment interiors.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... § 121.312 Materials for compartment interiors. (a) All interior materials; transport category airplanes and nontransport category airplanes type certificated before January 1, 1965. Except for the materials..., must comply with the material requirements under which the airplane was type certificated,...

  8. 14 CFR 91.613 - Materials for compartment interiors.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... materials. For transport category airplanes type certificated after January 1, 1958: (1) For airplanes... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Materials for compartment interiors. 91.613... and Operating Requirements for Large and Transport Category Aircraft § 91.613 Materials...

  9. 14 CFR 23.853 - Passenger and crew compartment interiors.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... breakage or failure of such an item would not create a hazard. (f) Airplane materials located on the cabin... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES... compartment to be used by the crew or passengers: (a) The materials must be at least flame-resistant; (b)...

  10. 14 CFR 121.312 - Materials for compartment interiors.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... § 121.312 Materials for compartment interiors. (a) All interior materials; transport category airplanes and nontransport category airplanes type certificated before January 1, 1965. Except for the materials..., must comply with the material requirements under which the airplane was type certificated,...

  11. 14 CFR 121.314 - Cargo and baggage compartments.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... and baggage compartments. For each transport category airplane type certificated after January 1, 1958... sidewall liner panels which are constructed of: (1) Glass fiber reinforced resin; (2) Materials which meet... number of each airplane listed in the operations specifications issued to the certificate holder...

  12. 14 CFR 91.613 - Materials for compartment interiors.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... materials. For transport category airplanes type certificated after January 1, 1958: (1) For airplanes... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Materials for compartment interiors. 91.613... and Operating Requirements for Large and Transport Category Aircraft § 91.613 Materials...

  13. 14 CFR 91.613 - Materials for compartment interiors.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... materials. For transport category airplanes type certificated after January 1, 1958: (1) For airplanes... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Materials for compartment interiors. 91.613... and Operating Requirements for Large and Transport Category Aircraft § 91.613 Materials...

  14. 14 CFR 121.312 - Materials for compartment interiors.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... § 121.312 Materials for compartment interiors. (a) All interior materials; transport category airplanes and nontransport category airplanes type certificated before January 1, 1965. Except for the materials..., must comply with the material requirements under which the airplane was type certificated,...

  15. 14 CFR 23.853 - Passenger and crew compartment interiors.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... breakage or failure of such an item would not create a hazard. (f) Airplane materials located on the cabin... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES... compartment to be used by the crew or passengers: (a) The materials must be at least flame-resistant; (b)...

  16. 14 CFR 121.312 - Materials for compartment interiors.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... § 121.312 Materials for compartment interiors. (a) All interior materials; transport category airplanes and nontransport category airplanes type certificated before January 1, 1965. Except for the materials..., must comply with the material requirements under which the airplane was type certificated,...

  17. 14 CFR 23.853 - Passenger and crew compartment interiors.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... breakage or failure of such an item would not create a hazard. (f) Airplane materials located on the cabin... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES... compartment to be used by the crew or passengers: (a) The materials must be at least flame-resistant; (b)...

  18. Does oedema following lower limb revascularisation cause compartment syndromes?

    PubMed Central

    Scott, D. J.; Allen, M. J.; Bell, P. R.; McShane, M.; Barnes, M. R.

    1988-01-01

    Oedema of the leg, particularly the calf, is a well-recognised complication following lower limb reconstructive vascular surgery, but its effect on the limb is unknown. In this study, anterior compartment pressures and calf circumference were measured in both the operated and non-operated limbs following femoropopliteal bypass in 15 patients. All the patients developed lower limb swelling, which was significantly greater than the non-operated limb, P less than 0.05 paired t test (day 2-5). There was a significant difference in the mean anterior compartment pressures between the operated and non-operated limbs on the third and fourth postoperative days for the overall and below knee group, P less than 0.05 (paired t test). However, none of the patients developed signs, symptoms or pressures indicative of a compartment syndrome. These results suggest that the oedema following reconstructive vascular surgery is subcutaneous rather than compartmental in origin and that compartment pressure measurements should only be undertaken if a fasciotomy is being contemplated. Images fig. 2 PMID:3207329

  19. 12. Interior view of battle staff compartment showing the general's ...

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

    12. Interior view of battle staff compartment showing the general's chair. View toward front of aircraft. - Offutt Air Force Base, Looking Glass Airborne Command Post, Looking Glass Aircraft, On Operational Apron covering northeast half of Project Looking Glass Historic District, Bellevue, Sarpy County, NE

  20. Digital Microscopy Assessment of Angiogenesis in Different Breast Cancer Compartments

    PubMed Central

    Rogojanu, Radu; Croitoru, Camelia; Jitaru, Daniela; Tarniceriu, Cristina; Carasevici, Eugen

    2013-01-01

    Background/Aim. Tumour angiogenesis defined by microvessel density (MVD) is generally accepted as a prognostic factor in breast cancer. However, due to variability of measurement systems and cutoffs, it is questionable to date whether it contributes to predictive outline. Our study aims to grade vascular heterogeneity by comparing clear-cut compartments: tumour associated stroma (TAS), tumour parenchyma, and tumour invasive front. Material and Methods. Computerized vessel area measurement was performed using a tissue cytometry system (TissueFAXS) on slides originated from 50 patients with breast cancer. Vessels were marked using immunohistochemistry with CD34. Regions of interest were manually defined for each tumour compartment. Results. Tumour invasive front vascular endothelia area was 2.15 times higher than that in tumour parenchyma and 4.61 times higher than that in TAS (P < 0.002). Worth to mention that the lymph node negative subgroup of patients show a slight but constant increase of vessel index in all examined compartments of breast tumour. Conclusion. Whole slide digital examination and region of interest (ROI) analysis are a valuable tool in scoring angiogenesis markers and disclosing their prognostic capacity. Our study reveals compartments' variability of vessel density inside the tumour and highlights the propensity of invasive front to associate an active process of angiogenesis with potential implications in adjuvant therapy. PMID:24073397

  1. 38. Port side of engine compartment at salon deck level, ...

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

    38. Port side of engine compartment at salon deck level, with salon wall panels removed to show engine frame. Main connecting rod from crank to walking beam appears at extreme right of view, top of cylinder and piston rod appear at extreme left. - Ferry TICONDEROGA, Route 7, Shelburne, Chittenden County, VT

  2. 14 CFR 125.167 - Extinguishing agent container compartment temperature.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... temperature. 125.167 Section 125.167 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Requirements § 125.167 Extinguishing agent container compartment temperature. Precautions must be taken to ensure that the extinguishing agent containers are installed in places where reasonable temperatures...

  3. 14 CFR 125.167 - Extinguishing agent container compartment temperature.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... temperature. 125.167 Section 125.167 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Requirements § 125.167 Extinguishing agent container compartment temperature. Precautions must be taken to ensure that the extinguishing agent containers are installed in places where reasonable temperatures...

  4. 14 CFR 121.269 - Extinguishing agent container compartment temperature.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... temperature. 121.269 Section 121.269 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF....269 Extinguishing agent container compartment temperature. Precautions must be taken to insure that the extinguishing agent containers are installed in places where reasonable temperatures can...

  5. 14 CFR 125.167 - Extinguishing agent container compartment temperature.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... temperature. 125.167 Section 125.167 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Requirements § 125.167 Extinguishing agent container compartment temperature. Precautions must be taken to ensure that the extinguishing agent containers are installed in places where reasonable temperatures...

  6. 14 CFR 121.269 - Extinguishing agent container compartment temperature.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... temperature. 121.269 Section 121.269 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF....269 Extinguishing agent container compartment temperature. Precautions must be taken to insure that the extinguishing agent containers are installed in places where reasonable temperatures can...

  7. 14 CFR 121.269 - Extinguishing agent container compartment temperature.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... temperature. 121.269 Section 121.269 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF....269 Extinguishing agent container compartment temperature. Precautions must be taken to insure that the extinguishing agent containers are installed in places where reasonable temperatures can...

  8. 14 CFR 121.269 - Extinguishing agent container compartment temperature.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... temperature. 121.269 Section 121.269 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF....269 Extinguishing agent container compartment temperature. Precautions must be taken to insure that the extinguishing agent containers are installed in places where reasonable temperatures can...

  9. 14 CFR 121.269 - Extinguishing agent container compartment temperature.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... temperature. 121.269 Section 121.269 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF....269 Extinguishing agent container compartment temperature. Precautions must be taken to insure that the extinguishing agent containers are installed in places where reasonable temperatures can...

  10. 14 CFR 125.167 - Extinguishing agent container compartment temperature.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... temperature. 125.167 Section 125.167 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Requirements § 125.167 Extinguishing agent container compartment temperature. Precautions must be taken to ensure that the extinguishing agent containers are installed in places where reasonable temperatures...

  11. 14 CFR 125.167 - Extinguishing agent container compartment temperature.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... temperature. 125.167 Section 125.167 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Requirements § 125.167 Extinguishing agent container compartment temperature. Precautions must be taken to ensure that the extinguishing agent containers are installed in places where reasonable temperatures...

  12. 14 CFR 29.855 - Cargo and baggage compartments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... accessories whose damage or failure would affect safe operation, unless those items are protected so that— (1... endangering the safety of a rotorcraft or its occupants must be designed, or must have a device, to ensure... area may be considered a cargo compartment and, in addition to paragraphs (a) through (d) of...

  13. Test strips detect different CO2 concentrations in closed compartments

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Four different test strips, using crystal violet for one pair of strips and basic fuchsin as a dye for the second pair, give unambiguous colorimetric indications of four different concentrations of carbon dioxide in the atmosphere of a closed compartment. Tetraethylene pentamine is used as a dye decoloring agent.

  14. 46 CFR 174.075 - Compartments assumed flooded: general.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Compartments assumed flooded: general. 174.075 Section 174.075 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY SPECIAL RULES PERTAINING TO SPECIFIC VESSEL TYPES Special Rules Pertaining to Mobile Offshore...

  15. 46 CFR 174.075 - Compartments assumed flooded: general.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Compartments assumed flooded: general. 174.075 Section 174.075 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY SPECIAL RULES PERTAINING TO SPECIFIC VESSEL TYPES Special Rules Pertaining to Mobile Offshore...

  16. 19 CFR 123.24 - Sealing of conveyances or compartments.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 1 2012-04-01 2012-04-01 false Sealing of conveyances or compartments. 123.24 Section 123.24 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY CBP RELATIONS WITH CANADA AND MEXICO Shipments in Transit Through Canada or...

  17. 9 CFR 354.241 - Cleaning of rooms and compartments.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Cleaning of rooms and compartments... Sanitary Conditions and Precautions Against Contamination of Products § 354.241 Cleaning of rooms and... rooms shall be of such construction as readily to permit their thorough cleaning, and such docks...

  18. 14 CFR 27.855 - Cargo and baggage compartments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Cargo and baggage compartments. 27.855 Section 27.855 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Fire Protection §...

  19. Compartment syndrome of the foot in a child.

    PubMed

    Sharma, A K; Sharaf, I; Ajay, S

    2001-06-01

    We report a case of a 12-year-old boy with acute compartment syndrome of the foot following a road-traffic accident. Due to the rarity of the injury, there was a delay in diagnosing the injury. An emergency fasciotomy was performed 19 hours after the injury. The foot healed with a mild extension contracture of the second toe.

  20. 49 CFR 179.220-9 - Compartment tanks.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Compartment tanks. 179.220-9 Section 179.220-9 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specifications for...

  1. 49 CFR 179.200-9 - Compartment tanks.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Compartment tanks. 179.200-9 Section 179.200-9 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specifications for...

  2. 49 CFR 179.200-9 - Compartment tanks.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Compartment tanks. 179.200-9 Section 179.200-9 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specifications for...

  3. 49 CFR 179.200-9 - Compartment tanks.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Compartment tanks. 179.200-9 Section 179.200-9 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specifications for...

  4. 9 CFR 354.221 - Rooms and compartments.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Rooms and compartments. 354.221 Section 354.221 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE... needs of the inspection in the plant may require. They shall be equipped with locks and keys and...

  5. 9 CFR 354.221 - Rooms and compartments.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Rooms and compartments. 354.221 Section 354.221 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE... needs of the inspection in the plant may require. They shall be equipped with locks and keys and...

  6. 9 CFR 354.221 - Rooms and compartments.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Rooms and compartments. 354.221 Section 354.221 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE... needs of the inspection in the plant may require. They shall be equipped with locks and keys and...

  7. 9 CFR 354.221 - Rooms and compartments.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Rooms and compartments. 354.221 Section 354.221 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE... needs of the inspection in the plant may require. They shall be equipped with locks and keys and...

  8. KINETICS STUDY ON KETOPROFEN RELEASE FROM MINI TABLETS AND MULTI-COMPARTMENT SYSTEMS.

    PubMed

    Stawarski, Tomasz; Sieradzki, Edmund; Gałecka, Emilia; Binek, Karolina

    2016-01-01

    Thanks to multi-compartment systems it is possible to modify drug release. Two types of mini tablets containing 12.5 mg of ketoprofen were made: mini tablets of immediate (IR) and sustained (SR) release. Some of the tablets of immediate release were coated with an enteric coating, thereby obtaining a delayed release effect (IRc). For each tablet type, release profiles were tested in three media: 0.1 M HCl, phosphate buffer pH 4.5 and phosphate buffer pH 6.8. Based on the obtained results, three appropriate multi-compartment models have been constructed and tested. The factor limiting the amount of available ketoprofen at the absorption place is pH of the environment. It was observed that the increase in pH caused the increase of ketoprofen solubility. Constructed multi-compartment systems allowed to change the composition and the dose of medicinal substances easily. Thanks to this it is possible to adjust the release profile of the active substance to the individual patient, which meets the expectations of personalized medicine.

  9. The study of solid circulation rate in a compartmented fluidized bed gasifier (CFBG)

    NASA Astrophysics Data System (ADS)

    Wee, S. K.; Pok, Y. W.; Law, M. C.; Lee, V. C. C.

    2016-06-01

    Biomass waste has been abundantly available in Malaysia since the booming of palm oil industry. In order to tackle this issue, gasification is seen a promising technology to convert waste into energy. In view of the heat requirement for endothermic gasification reaction as well as the complex design and operation of multiple fluidized beds, compartmented fluidized bed gasifier (CFBG) with the combustor and the gasifier as separate compartments is proposed. As such, solid circulation rate (SCR) is one of the essential parameters for steady gasification and combustion to be realized in their respective compartments. Experimental and numerical studies (CFD) on the effect of static bed height, main bed aeration, riser aeration and v-valve aeration on SCR have been conducted in a cold- flow CFBG model with only river sand as the fluidizing medium. At lower operating range, the numerical simulations under-predict the SCR as compared to that of the experimental results. Also, it predicts slightly different trends over the range. On the other hand, at higher operating range, the numerical simulations are able to capture those trends as observed in the experimental results at the lower operating range. Overall, the numerical results compare reasonably well with that of the experimental works.

  10. Functional and Phylogenetic Characterization of Proteins Detected in Various Nematode Intestinal Compartments*

    PubMed Central

    Rosa, Bruce A.; Townsend, Reid; Jasmer, Douglas P.; Mitreva, Makedonka

    2015-01-01

    The parasitic nematode intestine is responsible for nutrient digestion and absorption, and many other processes essential for reproduction and survival, making it a valuable target for anthelmintic drug treatment. However, nematodes display extreme biological diversity (including occupying distinct trophic habitats), resulting in limited knowledge of intestinal cell/protein functions of fundamental or adaptive significance. We developed a perfusion model for isolating intestinal proteins in Ascaris suum (a parasite of humans and swine), allowing for the identification of over 1000 intestinal A. suum proteins (using mass spectrometry), which were assigned to several different intestinal cell compartments (intestinal tissue, the integral and peripheral intestinal membranes, and the intestinal lumen). A multi-omics analysis approach identified a large diversity of biological functions across intestinal compartments, based on both functional enrichment analysis (identifying terms related to detoxification, proteolysis, and host-parasite interactions) and regulatory binding sequence analysis to identify putatively active compartment-specific transcription factors (identifying many related to intestinal sex differentiation or lifespan regulation). Orthologs of A. suum proteins in 15 other nematodes species, five host species, and two outgroups were identified and analyzed. Different cellular compartments demonstrated markedly different levels of protein conservation; e.g. integral intestinal membrane proteins were the most conserved among nematodes (up to 96% conservation), whereas intestinal lumen proteins were the most diverse (only 6% conservation across all nematodes, and 71% with no host orthologs). Finally, this integrated multi-omics analysis identified conserved nematode-specific intestinal proteins likely performing essential functions (including V-type ATPases and ABC transporters), which may serve as promising anthelmintic drug or vaccine targets in future

  11. Functional and phylogenetic characterization of proteins detected in various nematode intestinal compartments.

    PubMed

    Rosa, Bruce A; Townsend, Reid; Jasmer, Douglas P; Mitreva, Makedonka

    2015-04-01

    The parasitic nematode intestine is responsible for nutrient digestion and absorption, and many other processes essential for reproduction and survival, making it a valuable target for anthelmintic drug treatment. However, nematodes display extreme biological diversity (including occupying distinct trophic habitats), resulting in limited knowledge of intestinal cell/protein functions of fundamental or adaptive significance. We developed a perfusion model for isolating intestinal proteins in Ascaris suum (a parasite of humans and swine), allowing for the identification of over 1000 intestinal A. suum proteins (using mass spectrometry), which were assigned to several different intestinal cell compartments (intestinal tissue, the integral and peripheral intestinal membranes, and the intestinal lumen). A multi-omics analysis approach identified a large diversity of biological functions across intestinal compartments, based on both functional enrichment analysis (identifying terms related to detoxification, proteolysis, and host-parasite interactions) and regulatory binding sequence analysis to identify putatively active compartment-specific transcription factors (identifying many related to intestinal sex differentiation or lifespan regulation). Orthologs of A. suum proteins in 15 other nematodes species, five host species, and two outgroups were identified and analyzed. Different cellular compartments demonstrated markedly different levels of protein conservation; e.g. integral intestinal membrane proteins were the most conserved among nematodes (up to 96% conservation), whereas intestinal lumen proteins were the most diverse (only 6% conservation across all nematodes, and 71% with no host orthologs). Finally, this integrated multi-omics analysis identified conserved nematode-specific intestinal proteins likely performing essential functions (including V-type ATPases and ABC transporters), which may serve as promising anthelmintic drug or vaccine targets in future

  12. Multimodal delivery of irinotecan from microparticles with two distinct compartments.

    PubMed

    Rahmani, Sahar; Park, Tae-Hong; Dishman, Acacia Frances; Lahann, Joerg

    2013-11-28

    In the last several decades, research in the field of drug delivery has been challenged with the fabrication of carrier systems engineered to deliver therapeutics to the target site with sustained and controlled release kinetics. Herein, we report the fabrication of microparticles composed of two distinct compartments: i) one compartment containing a pH responsive polymer, acetal-modified dextran, and PLGA (polylactide-co-glycolide), and ii) one compartment composed entirely of PLGA. We demonstrate the complete release of dextran from the microparticles during a 10-hour period in an acidic pH environment and the complete degradation of one compartment in less than 24h. This is in congruence with the stability of the same microparticles in neutral pH over the 24-hour period. Such microparticles can be used as pH responsive carrier systems for drug delivery applications where their cargo will only be released when the optimum pH window is reached. The feasibility of the microparticle system for such an application was confirmed by encapsulating a cancer therapeutic, irinotecan, in the compartment containing the acetal-modified dextran polymer and the pH dependent release over a 5-day period was studied. It was found that upon pH change to an acidic environment, over 50% of the drug was first released at a rapid rate for 10h, similar to that observed for the dextran release, before continuing at a more controlled rate for 4 days. As such, these microparticles can play an important role in the fabrication of novel drug delivery systems due to the selective, controlled, and pH responsive release of their encapsulated therapeutics.

  13. MODELLING OF AGRICHEMICALS IN ENVIRONMENTAL COMPARTMENTS - CONCEPTS, PROBLEMS, AND SOLUTIONS

    EPA Science Inventory

    The potential of plant protection chemicals to migrate away from application sites and expose non-target biota is of continuing interest and concern to regulatory specialists, ecotoxicologists, agriculturalists, and natural resource managers. Regulatory decisions can wait upon ne...

  14. Thermal Analysis and Test Program to Evaluate Passenger Compartment Thermal Load Reduction and Improve: Cooperative Research and Development Final Report, CRADA number CRD-07-00231

    SciTech Connect

    Rugh, J.

    2011-05-01

    This activity supported a GM and NREL collaborative exploration of strategies to minimize and alleviate the temperature rise in the passenger compartment of an automobile during prolonged exposure to solar radiation in hot climates. It developed and exercised math-based models to simulate the air flow and thermal environment in the passenger compartment in order to compare the effectiveness of the strategies. This activity also assessed the strategies using vehicle tests.

  15. Comparison of the predictions of one- and two-compartment microcomputer programs for long-term tobramycin therapy.

    PubMed

    Hatton, R C; Massey, K L; Russell, W L

    1984-01-01

    A retrospective study of patients receiving tobramycin compared the accuracy of predictions of actual trough serum concentrations using two commercially available microcomputer software programs. Twelve patients met the study criteria of intravenous tobramycin treatment for more than 10 days with serum concentration monitoring within the first 5 days and after 10 days of therapy. No patients received dialysis. Twenty-five serum concentrations were compared. Predictions within 0.2 microgram/ml were considered clinically "exact." No significant differences were found by chi-square analysis for any of the four possible choices (p less than 0.3). One of the programs, distributed by Dista Pharmaceuticals, offers a one-compartment model, a two-compartment model, and a two-compartment prenephrotoxic option. SIMKIN, a program marketed by Medical Engineering, Inc., uses a two-compartment model. Overall, the predictions errors were small, but occasionally were clinically significant. Further evaluation of microcomputer programs for therapeutic drug monitoring is necessary to document their impact on predicting drug efficacy and toxicity.

  16. Endoscopic Thermal Fasciotomy for Chronic Exertional Compartment Syndrome

    PubMed Central

    Voleti, Pramod B.; Lebrun, Drake G.; Roth, Cameron A.; Kelly, John D.

    2015-01-01

    Chronic exertional compartment syndrome is an activity-induced condition that occurs when intracompartmental pressures within an osteofascial envelope increase during exercise, leading to reversible ischemic symptoms such as pain, cramping, numbness, or weakness. Nonoperative treatment options for this condition have shown limited success and are often undesirable for the patient given the requirement for activity modification. Traditional surgical treatment options involving open or subcutaneous fasciotomies have more favorable results, but these techniques are associated with significant morbidity. Endoscopically assisted fasciotomy techniques afford the advantages of being minimally invasive, providing excellent visualization, and allowing accelerated rehabilitation. The purpose of this article is to describe a technique for performing endoscopically assisted fasciotomies for chronic exertional compartment syndrome of the lower leg using an entirely endoscopic thermal ablating device. The endoscopic thermal fasciotomy technique is associated with minimal morbidity, ensures excellent hemostasis, and affords an early return to sports. PMID:26900549

  17. p73-induced apoptosis: A question of compartments and cooperation

    SciTech Connect

    Dobbelstein, Matthias; Strano, Sabrina; Roth, Judith; Blandino, Giovanni . E-mail: blandino@ifo.it

    2005-06-10

    The transcriptionally active forms of p73 are capable of inducing apoptosis, and the isoforms termed TAp73 are important players when E2F and its oncogenic activators induce programmed cell death. However, the conditions under that TAp73 can kill a cell remain to be clarified. Recently, it has been found that p73 proteins are not merely floating in the nucleoplasm but rather can associate with specific compartments in the cell. Examples of intranuclear compartments associated with p73 proteins include the PML oncogenic domains and the nuclear matrix. In addition, p73 is found in the cytoplasm. It remains to be seen whether p73 might also associate with mitochondria, in analogy with p53. The relocalization of p73 is expected to be mediated by specific binding partners, mostly other proteins. Here, we discuss the possibility that the compartmentalization of p73, and the cooperation with the corresponding binding partners, might decide about its apoptosis-inducing activity.

  18. Head and neck fascia and compartments: no space for spaces.

    PubMed

    Guidera, Alice K; Dawes, Patrick J D; Fong, Amy; Stringer, Mark D

    2014-07-01

    An accurate understanding of the arrangement of cervical fascia and its associated compartments is essential for differential diagnosis, predicting the spread of disease, and surgical management. The purpose of this detailed review is to summarize the anatomic, clinical, and radiological literature to determine what is known about the arrangement of cervical fascia and to highlight controversies and consensus. The current terminology used to describe cervical fascia and compartments is replete with confusing synonyms and inconsistencies, creating important interdisciplinary differences in understanding. The term "spaces" is inappropriate. A modified nomenclature underpinned by evidence-based anatomic and radiologic findings is proposed. This should not only enhance our understanding of cervical anatomy but also facilitate clearer interdisciplinary communication.

  19. Emerging Technologies and Their Applications in Lipid Compartment Measurement

    PubMed Central

    Heymsfield, Steven B.; Hu, Houchun Harry; Shen, Wei; Carmichael, Owen

    2015-01-01

    Non-Communicable diseases (NCDs), including obesity, are emerging as the major health concern of the 21st century. Excess adiposity and related NCD metabolic disturbances have stimulated development of new lipid compartment measurement technologies to help us understand cellular energy exchange, to refine phenotypes, and to develop predictive markers of adverse clinical outcomes. Recent advances now allow for quantification of multiple intracellular lipid and adipose tissue compartments that can be evaluated across the human lifespan. With magnetic resonance methods leading the way, newer approaches will give molecular structural and metabolic information beyond the laboratory in real-world settings. The union between these new technologies and the growing NCD population is creating an exciting interface advancing our understanding of chronic disease mechanisms. PMID:26596676

  20. Measuring Compartment Size and Gas Solubility in Marine Mammals

    DTIC Science & Technology

    2014-09-30

    dissection data were collected from one spotted dolphin , one bottlenose dolphin , three common dolphins , one elephant seal, three californian sea lions and...deviation for body compartments of three common dolphins of similar age (subadults and adults) but with different body condition. Muscle was the most...AL, Dennison SE, Early G, Garner MM, Hayward BA, Lentell BJ, Rotstein DS (2009) Gas Bubbles in Seals, Dolphins , and Porpoises Entangled and Drowned

  1. Closeup view if the starboard side of the crew compartment ...

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

    Close-up view if the starboard side of the crew compartment mid-deck of the Orbiter Discovery. This is a close up view of the galley for meal preparations. In the center right of the image is stowage lockers that are designated to store meals for the mission. This photograph was taken at Kennedy Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  2. Diagnosis of Compartment Syndrome Based on Tissue Oxygenation

    DTIC Science & Technology

    2013-10-01

    measured with microprobes has been shown to be highly correlated with tissue oxygenation and the extent of ischemia reperfusion injury .3 Near-infrared...Tissue Oxygenation PRINCIPAL INVESTIGATOR: Hubert Kim, M.D., Ph.D. CONTRACTING ORGANIZATION: Northern California Institute for...SUBTITLE Diagnosis of Compartment Syndrome based on Tissue Oxygenation 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-10-1-1024 5c. PROGRAM ELEMENT

  3. Bacterial assemblages differ between compartments within the coral holobiont

    NASA Astrophysics Data System (ADS)

    Sweet, M. J.; Croquer, A.; Bythell, J. C.

    2011-03-01

    It is widely accepted that corals are associated with a diverse and host species-specific microbiota, but how they are organized within their hosts remains poorly understood. Previous sampling techniques (blasted coral tissues, coral swabs and milked mucus) may preferentially sample from different compartments such as mucus, tissue and skeleton, or amalgamate them, making comparisons and generalizations between studies difficult. This study characterized bacterial communities of corals with minimal mechanical disruption and contamination from water, air and sediments from three compartments: surface mucus layer (SML), coral tissue and coral skeleton. A novel apparatus (the `snot sucker') was used to separate the SML from tissues and skeleton, and these three compartments were compared to swab samples and milked mucus along with adjacent environmental samples (water column and sediments). Bacterial 16S rRNA gene diversity was significantly different between the various coral compartments and environmental samples (PERMANOVA, F = 6.9, df = 8, P = 0.001), the only exceptions being the complete crushed coral samples and the coral skeleton, which were similar, because the skeleton represents a proportionally large volume and supports a relatively rich microflora. Milked mucus differed significantly from the SML collected with the `snot sucker' and was contaminated with zooxanthellae, suggesting that it may originate at least partially from the gastrovascular cavity rather than the tissue surface. A common method of sampling the SML, surface swabs, produced a bacterial community profile distinct from the SML sampled using our novel apparatus and also showed contamination from coral tissues. Our results indicate that microbial communities are spatially structured within the coral holobiont, and methods used to describe these need to be standardized to allow comparisons between studies.

  4. Closeup view of the reflective insulation protecting the Crew Compartment ...

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

    Close-up view of the reflective insulation protecting the Crew Compartment bulkhead, orbiter structure and landing gear housing in the void created by the removal of the Forward Reaction Control System Module from the forward section of the Orbiter Discovery. This image was taken from the service platform in the Orbiter Processing Facility at Kennedy Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  5. Compartment syndrome after total knee arthroplasty: regarding a clinical case☆

    PubMed Central

    Pinheiro, Ana Alexandra da Costa; Marques, Pedro Miguel Dantas Costa; Sá, Pedro Miguel Gomes; Oliveira, Carolina Fernandes; da Silva, Bruno Pombo Ferreira; de Sousa, Cristina Maria Varino

    2015-01-01

    Although compartment syndrome is a rare complication of total knee arthroplasty, it is one of the most devastating complications. It is defined as a situation of increased pressure within a closed osteofascial space that impairs the circulation and the functioning of the tissues inside this space, thereby leading to ischemia and tissue dysfunction. Here, a clinical case of a patient who was followed up in orthopedic outpatient consultations due to right gonarthrosis is presented. The patient had a history of arthroscopic meniscectomy and presented knee flexion of 10° before the operation, which consisted of total arthroplasty of the right knee. The operation seemed to be free from intercurrences, but the patient evolved with compartment syndrome of the ipsilateral leg after the operation. Since compartment syndrome is a true surgical emergency, early recognition and treatment of this condition through fasciotomy is crucial in order to avoid amputation, limb dysfunction, kidney failure and death. However, it may be difficult to make the diagnosis and cases may not be recognized if the cause of compartment syndrome is unusual or if the patient is under epidural analgesia and/or peripheral nerve block, which thus camouflages the main warning sign, i.e. disproportional pain. In addition, edema of the limb that underwent the intervention is common after total knee arthroplasty operations. This study presents a review of the literature and signals that the possible rarity of cases is probably due to failure to recognize this condition in a timely manner and to placing these patients in other diagnostic groups that are less likely, such as neuropraxia caused by using a tourniquet or peripheral nerve injury. PMID:26401507

  6. Independent Passive Mechanical Behavior of Bovine Extraocular Muscle Compartments

    PubMed Central

    Shin, Andrew; Yoo, Lawrence; Chaudhuri, Zia; Demer, Joseph L.

    2012-01-01

    Purpose. Intramuscular innervation of horizontal rectus extraocular muscles (EOMs) is segregated into superior and inferior (transverse) compartments, while all EOMs are also divided into global (GL) and orbital (OL) layers with scleral and pulley insertions, respectively. We sought evidence of potential independent action by examining passive mechanical coupling between EOM compartments. Methods. Putative compartments of each of the six whole bovine anatomical EOMs were separately clamped to a physiologically controlled, dual channel microtensile load cell (5-mN force resolution) driven by independent, high-speed, linear motors having 20-nm position resolution. One channel at a time was extended or retracted by 3 to 5 mm, with the other channel stationary. Fiducials distributed on the EOM global surface enabled optical tracking of local deformation. Loading rates of 5 to 100 mm/sec were applied to explore speeds from slow vergence to saccades. Control loadings employed transversely loaded EOM and isotropic latex. Results. All EOM bellies and tendons exhibited substantial compartmental independence when loaded in the physiologic direction, both between OL and GL, and for arbitrary transverse parsings of EOM width ranging from 60%:40% to 80%:20%. Intercompartmental force coupling in the physiologic direction was less than or equal to 10% in all six EOMS even for saccadic loading rates. Coupling was much higher for nonphysiologic transverse EOM loading and isotropic latex. Optical tracking demonstrated independent strain distribution between EOM compartments. Conclusions. Substantial mechanical independence exists among physiologically loaded fiber bundles in bovine EOMs and tendons, providing biomechanical support for the proposal that differential compartmental function in horizontal rectus EOMs contributes to novel torsional and vertical actions. PMID:23188730

  7. Rare times rare: The hyponatremia, rhabdomyolysis, anterior compartment syndrome sequence

    PubMed Central

    Dubin, Ina; Gelber, Moshe

    2016-01-01

    Lesson Primary polydipsia occurs in up to 25% of patients with chronic psychiatric disorders (especially schizophrenia), related to the disease, its treatment or both. Urine output fails to match intake >10 L/day and water intoxication may develop. Rhabdomyolysis is a rare complication of hyponatremia, and an acute anterior compartment syndrome of the leg, an emergency, may be very rarely associated. PMID:27186379

  8. Ruptured Baker's cyst with compartment syndrome: an extremely unusual complication.

    PubMed

    Hamlet, Mark; Galanopoulos, Ilias; Mahale, Avinash; Ashwood, Neil

    2012-12-20

    A 69-year-old man presented with sudden onset of pain with acute tense swelling of his left leg. Initially he was treated empirically with antibiotics for cellulitis while the possibility of deep vein thrombosis was ruled out. His symptoms gradually worsened with progressive distal neurological deficit and increasing pain. Further investigations suggested that he had a ruptured Baker's cyst in the calf with development of compartment syndrome.

  9. Compartment syndrome after total knee arthroplasty: regarding a clinical case.

    PubMed

    Pinheiro, Ana Alexandra da Costa; Marques, Pedro Miguel Dantas Costa; Sá, Pedro Miguel Gomes; Oliveira, Carolina Fernandes; da Silva, Bruno Pombo Ferreira; de Sousa, Cristina Maria Varino

    2015-01-01

    Although compartment syndrome is a rare complication of total knee arthroplasty, it is one of the most devastating complications. It is defined as a situation of increased pressure within a closed osteofascial space that impairs the circulation and the functioning of the tissues inside this space, thereby leading to ischemia and tissue dysfunction. Here, a clinical case of a patient who was followed up in orthopedic outpatient consultations due to right gonarthrosis is presented. The patient had a history of arthroscopic meniscectomy and presented knee flexion of 10° before the operation, which consisted of total arthroplasty of the right knee. The operation seemed to be free from intercurrences, but the patient evolved with compartment syndrome of the ipsilateral leg after the operation. Since compartment syndrome is a true surgical emergency, early recognition and treatment of this condition through fasciotomy is crucial in order to avoid amputation, limb dysfunction, kidney failure and death. However, it may be difficult to make the diagnosis and cases may not be recognized if the cause of compartment syndrome is unusual or if the patient is under epidural analgesia and/or peripheral nerve block, which thus camouflages the main warning sign, i.e. disproportional pain. In addition, edema of the limb that underwent the intervention is common after total knee arthroplasty operations. This study presents a review of the literature and signals that the possible rarity of cases is probably due to failure to recognize this condition in a timely manner and to placing these patients in other diagnostic groups that are less likely, such as neuropraxia caused by using a tourniquet or peripheral nerve injury.

  10. RAB24 facilitates clearance of autophagic compartments during basal conditions

    PubMed Central

    Ylä-Anttila, Päivi; Mikkonen, Elisa; Happonen, Kaisa E; Holland, Petter; Ueno, Takashi; Simonsen, Anne; Eskelinen, Eeva-Liisa

    2015-01-01

    RAB24 belongs to a family of small GTPases and has been implicated to function in autophagy. Here we confirm the intracellular localization of RAB24 to autophagic vacuoles with immuno electron microscopy and cell fractionation, and show that prenylation and guanine nucleotide binding are necessary for the targeting of RAB24 to autophagic compartments. Further, we show that RAB24 plays a role in the maturation and/or clearance of autophagic compartments under nutrient-rich conditions, but not during short amino acid starvation. Quantitative electron microscopy shows an increase in the numbers of late autophagic compartments in cells silenced for RAB24, and mRFP-GFP-LC3 probe and autophagy flux experiments indicate that this is due to a hindrance in their clearance. Formation of autophagosomes is shown to be unaffected by RAB24-silencing with siRNA. A defect in aggregate clearance in the absence of RAB24 is also shown in cells forming polyglutamine aggregates. This study places RAB24 function in the termination of the autophagic process under nutrient-rich conditions. PMID:26325487

  11. Deltoid Compartment Syndrome: A Rare Complication after Humeral Intraosseous Access

    PubMed Central

    Thadikonda, Kishan M.; Ma, Irene; Spiess, Alexander M.

    2017-01-01

    Summary: We present a case of a 65-year-old woman who developed a delayed deltoid compartment syndrome after resuscitation via humeral intraosseous access. Initially she was treated conservatively but then was taken emergently for a fasciotomy. After confirming the diagnosis with compartment pressures, a 2-incision approach was employed and a large hematoma was evacuated from the inferior margin of the anterior deltoid. The rest of the deltoid was inspected and debrided to healthy bleeding tissue. Her fasciotomy wounds were left open to heal on their own due to her tenuous clinical condition. At most recent follow-up, she had full range of motion in her shoulder and no residual pain. Our unique case study is the first documented incidence of upper extremity compartment syndrome after intraosseous access. Additionally, our case supports using humeral access only as a second-line option if lower extremity access is not available and prolonged vigilant monitoring after discontinuing intraosseous access to prevent disastrous late complications. PMID:28203508

  12. Dynamically Active Compartments Coupled by a Stochastically Gated Gap Junction

    NASA Astrophysics Data System (ADS)

    Bressloff, Paul C.; Lawley, Sean D.

    2017-03-01

    We analyze a one-dimensional PDE-ODE system representing the diffusion of signaling molecules between two cells coupled by a stochastically gated gap junction. We assume that signaling molecules diffuse within the cytoplasm of each cell and then either bind to some active region of the cell's membrane (treated as a well-mixed compartment) or pass through the gap junction to the interior of the other cell. We treat the gap junction as a randomly fluctuating gate that switches between an open and a closed state according to a two-state Markov process. This means that the resulting PDE-ODE is stochastic due to the presence of a randomly switching boundary in the interior of the domain. It is assumed that each membrane compartment acts as a conditional oscillator, that is, it sits below a supercritical Hopf bifurcation. In the ungated case (gap junction always open), the system supports diffusion-induced oscillations, in which the concentration of signaling molecules within the two compartments is either in-phase or anti-phase. The presence of a reflection symmetry (for identical cells) means that the stochastic gate only affects the existence of anti-phase oscillations. In particular, there exist parameter choices where the gated system supports oscillations, but the ungated system does not, and vice versa. The existence of oscillations is investigated by solving a spectral problem obtained by averaging over realizations of the stochastic gate.

  13. View of bulkhead mounted steam powered windlass in compartment B126 ...

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

    View of bulkhead mounted steam powered windlass in compartment B-126 used for servicng boiler room compartments B-3 and B-4. (052A) - USS Olympia, Penn's Landing, 211 South Columbus Boulevard, Philadelphia, Philadelphia County, PA

  14. 46 CFR 58.16-20 - Ventilation of compartments containing gas-consuming appliances.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Ventilation of compartments containing gas-consuming... and Heating § 58.16-20 Ventilation of compartments containing gas-consuming appliances. (a... and the other extending to the overhead of the compartment. Powered ventilation may be used...

  15. 46 CFR 58.16-20 - Ventilation of compartments containing gas-consuming appliances.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Ventilation of compartments containing gas-consuming... and Heating § 58.16-20 Ventilation of compartments containing gas-consuming appliances. (a... and the other extending to the overhead of the compartment. Powered ventilation may be used...

  16. 46 CFR 58.16-20 - Ventilation of compartments containing gas-consuming appliances.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Ventilation of compartments containing gas-consuming... and Heating § 58.16-20 Ventilation of compartments containing gas-consuming appliances. (a... and the other extending to the overhead of the compartment. Powered ventilation may be used...

  17. 46 CFR 58.16-20 - Ventilation of compartments containing gas-consuming appliances.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Ventilation of compartments containing gas-consuming... and Heating § 58.16-20 Ventilation of compartments containing gas-consuming appliances. (a... and the other extending to the overhead of the compartment. Powered ventilation may be used...

  18. 46 CFR 58.16-20 - Ventilation of compartments containing gas-consuming appliances.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Ventilation of compartments containing gas-consuming... and Heating § 58.16-20 Ventilation of compartments containing gas-consuming appliances. (a... and the other extending to the overhead of the compartment. Powered ventilation may be used...

  19. Compartment A126 port side. Note ash hoist for boiler room ...

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

    Compartment A-126 port side. Note ash hoist for boiler room compartment B-1 and compartment B-2. Scuttlebutt (drinking water fountain) is at right center of photograph. Manikin wearing WWII wave uniform is in display case at left center. (045) - USS Olympia, Penn's Landing, 211 South Columbus Boulevard, Philadelphia, Philadelphia County, PA

  20. Acute compartment syndrome after muscle rupture in a non-athlete.

    PubMed Central

    Thennavan, A S; Funk, L; Volans, A P

    1999-01-01

    Acute compartment syndrome after muscle rupture, although rare, is a limb threatening condition, which warrants emergency treatment. The case of acute compartment syndrome secondary to a gastrocnemius muscle tear of the right lower leg, in a non-athlete is reported. To our knowledge, this is the only description of acute compartment syndrome due to muscle rupture in a non-athlete. PMID:10505928

  1. 14 CFR 121.587 - Closing and locking of flightcrew compartment door.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... compartment door. 121.587 Section 121.587 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... locking of flightcrew compartment door. (a) Except as provided in paragraph (b) of this section, a pilot in command of an airplane that has a lockable flightcrew compartment door in accordance with §...

  2. 14 CFR 121.587 - Closing and locking of flightcrew compartment door.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... compartment door. 121.587 Section 121.587 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... locking of flightcrew compartment door. (a) Except as provided in paragraph (b) of this section, a pilot in command of an airplane that has a lockable flightcrew compartment door in accordance with §...

  3. View forward to aft of compartment B126. Note steam powered ...

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

    View forward to aft of compartment B-126. Note steam powered windlass for ash hoist that services boiler room compartment B-3 and compartment B-4. Ash hoist conveyor rail is at top left. Diving suit and helmet dating from 1950's is displayed in case at center of photograph. (049) - USS Olympia, Penn's Landing, 211 South Columbus Boulevard, Philadelphia, Philadelphia County, PA

  4. 46 CFR 58.25-40 - Arrangement of the steering-gear compartment.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Arrangement of the steering-gear compartment. 58.25-40... AND AUXILIARY MACHINERY AND RELATED SYSTEMS Steering Gear § 58.25-40 Arrangement of the steering-gear compartment. (a) The steering-gear compartment must— (1) Be readily accessible and, as far as...

  5. 14 CFR 25.858 - Cargo or baggage compartment smoke or fire detection systems.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Cargo or baggage compartment smoke or fire... Construction Fire Protection § 25.858 Cargo or baggage compartment smoke or fire detection systems. If certification with cargo or baggage compartment smoke or fire detection provisions is requested, the...

  6. 14 CFR 25.858 - Cargo or baggage compartment smoke or fire detection systems.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Cargo or baggage compartment smoke or fire... Construction Fire Protection § 25.858 Cargo or baggage compartment smoke or fire detection systems. If certification with cargo or baggage compartment smoke or fire detection provisions is requested, the...

  7. 14 CFR 25.858 - Cargo or baggage compartment smoke or fire detection systems.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Cargo or baggage compartment smoke or fire... Construction Fire Protection § 25.858 Cargo or baggage compartment smoke or fire detection systems. If certification with cargo or baggage compartment smoke or fire detection provisions is requested, the...

  8. Acute compartment syndrome of the forearm caused by calcific tendinitis of the distal biceps.

    PubMed

    Garayoa, Santiago Amillo; Romero-Muñoz, Luis M; Pons-Villanueva, Juan

    2010-12-01

    Acute compartment syndrome of the forearm requires immediate treatment to avoid damage of the soft tissues and a poor functional outcome for the forearm. Muscular and bone lesions are the main causes of acute compartment syndromes. We report a case of acute compartment syndrome of the forearm caused by a calcific tendinitis of the distal biceps.

  9. 14 CFR 121.576 - Retention of items of mass in passenger and crew compartments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... crew compartments. 121.576 Section 121.576 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... § 121.576 Retention of items of mass in passenger and crew compartments. The certificate holder must... each item of crew baggage, which is carried in a passenger or crew compartment from becoming a...

  10. The influence of distributional kinetics into a peripheral compartment on the pharmacokinetics of substrate partitioning between blood and brain tissue.

    PubMed

    Padowski, Jeannie M; Pollack, Gary M

    2011-12-01

    Development of CNS-targeted agents often focuses on identifying compounds with "good" CNS exposure (brain-to-blood partitioning >1). Some compounds undergoing enterohepatic recycling (ER) evidence a partition coefficient, K (p,brain) (expressed as C (brain) /C (plasma)), that exceeds and then decreases to (i.e., overshoots) a plateau (distribution equilibrium) value, rather than increasing monotonically to this value. This study tested the hypothesis that overshoot in K (p,brain) is due to substrate residence in a peripheral compartment. Simulations were based on a 3-compartment model with distributional clearances between central and brain (CL (br)) and central and peripheral (CL (d)) compartments and irreversible clearance from the central compartment (CL). Parameters were varied to investigate the relationship between overshoot and peripheral compartment volume (V (p)), and how this relationship was modulated by other model parameters. Overshoot magnitude and duration were characterized as peak C (brain)/C (plasma) relative to the plateau value (%OS) and time to reach plateau (TRP). Except for systems with high CL (d), increasing V (p) increased TRP and %OS. Increasing brain (V (br)) or central (V (c)) distribution volumes eliminated V (p)-related OS. Parallel increases in all clearances shortened TRP, but did not alter %OS. Increasing either CL or CL (d) individually increased %OS related to V (p), while increasing CL (br) decreased %OS. Under realistic peripheral distribution scenarios, C (brain)/C (plasma) may overshoot substantially K (p,brain) at distribution equilibrium. This observation suggests potential for erroneous assessment of brain disposition, particularly for compounds which exhibit a large apparent V (p), and emphasizes the need for complete understanding of distributional kinetics when evaluating brain uptake.

  11. Enrichment of Phosphatidylethanolamine in Viral Replication Compartments via Co-opting the Endosomal Rab5 Small GTPase by a Positive-Strand RNA Virus

    PubMed Central

    Xu, Kai; Nagy, Peter D.

    2016-01-01

    Positive-strand RNA viruses build extensive membranous replication compartments to support replication and protect the virus from antiviral responses by the host. These viruses require host factors and various lipids to form viral replication complexes (VRCs). The VRCs built by Tomato bushy stunt virus (TBSV) are enriched with phosphatidylethanolamine (PE) through a previously unknown pathway. To unravel the mechanism of PE enrichment within the TBSV replication compartment, in this paper, the authors demonstrate that TBSV co-opts the guanosine triphosphate (GTP)-bound active form of the endosomal Rab5 small GTPase via direct interaction with the viral replication protein. Deletion of Rab5 orthologs in a yeast model host or expression of dominant negative mutants of plant Rab5 greatly decreases TBSV replication and prevents the redistribution of PE to the sites of viral replication. We also show that enrichment of PE in the viral replication compartment is assisted by actin filaments. Interestingly, the closely related Carnation Italian ringspot virus, which replicates on the boundary membrane of mitochondria, uses a similar strategy to the peroxisomal TBSV to hijack the Rab5-positive endosomes into the viral replication compartments. Altogether, usurping the GTP-Rab5–positive endosomes allows TBSV to build a PE-enriched viral replication compartment, which is needed to support peak-level replication. Thus, the Rab family of small GTPases includes critical host factors assisting VRC assembly and genesis of the viral replication compartment. PMID:27760128

  12. Simulation of the inhibition of microbial sulfate reduction in a two-compartment upflow bioreactor subjected to molybdate injection.

    PubMed

    de Jesus, E B; de Andrade Lima, L R P

    2016-08-01

    Souring of oil fields during secondary oil recovery by water injection occurs mainly due to the action of sulfate-reducing bacteria (SRB) adhered to the rock surface in the vicinity of injection wells. Upflow packed-bed bioreactors have been used in petroleum microbiology because of its similarity to the oil field near the injection wells or production. However, these reactors do not realistically describe the regions near the injection wells, which are characterized by the presence of a saturated zone and a void region close to the well. In this study, the hydrodynamics of the two-compartment packing-free/packed-bed pilot bioreactor that mimics an oil reservoir was studied. The packed-free compartment was modeled using a continuous stirred tank model with mass exchange between active and stagnant zones, whereas the packed-bed compartment was modeled using a piston-dispersion-exchange model. The proposed model adequately represents the hydrodynamic of the packed-free/packed-bed bioreactor while the simulations provide important information about the characteristics of the residence time distribution (RTD) curves for different sets of model parameters. Simulations were performed to represent the control of the sulfate-reducing bacteria activity in the bioreactor with the use of molybdate in different scenarios. The simulations show that increased amounts of molybdate cause an effective inhibition of the souring sulfate-reducing bacteria activity.

  13. Exercise-induced Pediatric Lumbar Paravertebral Compartment Syndrome: A Case Report.

    PubMed

    Schreiber, Verena M; Ward, W Timothy

    2015-09-01

    Acute compartment syndrome is described as an elevation of interstitial pressure in a closed fascial compartment that can lead to damage of the microvasculature with subsequent tissue necrosis. Although paravertebral compartment syndrome has been described there is no case of paravertebral compartment syndrome that has been described in the pediatric population. We report the case of a 17-year-old boy who presented at our institution with severe, acute-onset low back pain that started shortly after a rigorous 4-hour workout. He was diagnosed with acute lumbar paravertebral compartment syndrome and underwent emergent fasciotomy with 2 more debridements.

  14. Renal compartment segmentation in DCE-MRI images.

    PubMed

    Yang, Xin; Le Minh, Hung; Tim Cheng, Kwang-Ting; Sung, Kyung Hyun; Liu, Wenyu

    2016-08-01

    Renal compartment segmentation from Dynamic Contrast-Enhanced MRI (DCE-MRI) images is an important task for functional kidney evaluation. Despite advancement in segmentation methods, most of them focus on segmenting an entire kidney on CT images, there still lacks effective and automatic solutions for accurate segmentation of internal renal structures (i.e. cortex, medulla and renal pelvis) from DCE-MRI images. In this paper, we introduce a method for renal compartment segmentation which can robustly achieve high segmentation accuracy for a wide range of DCE-MRI data, and meanwhile requires little manual operations and parameter settings. The proposed method consists of five main steps. First, we pre-process the image time series to reduce the motion artifacts caused by the movement of the patients during the scans and enhance the kidney regions. Second, the kidney is segmented as a whole based on the concept of Maximally Stable Temporal Volume (MSTV). The proposed MSTV detects anatomical structures that are homogeneous in the spatial domain and stable in terms of temporal dynamics. MSTV-based kidney segmentation is robust to noises and does not require a training phase. It can well adapt to kidney shape variations caused by renal dysfunction. Third, voxels in the segmented kidney are described by principal components (PCs) to remove temporal redundancy and noises. And then k-means clustering of PCs is applied to separate voxels into multiple clusters. Fourth, the clusters are automatically labeled as cortex, medulla and pelvis based on voxels' geometric locations and intensity distribution. Finally, an iterative refinement method is introduced to further remove noises in each segmented compartment. Experiments on 14 real clinical kidney datasets and 12 synthetic dataset demonstrate that results produced by our method match very well with those segmented manually and the performance of our method is superior to the other five existing methods.

  15. Compartment-dependent mitochondrial alterations in experimental ALS, the effects of mitophagy and mitochondriogenesis.

    PubMed

    Natale, Gianfranco; Lenzi, Paola; Lazzeri, Gloria; Falleni, Alessandra; Biagioni, Francesca; Ryskalin, Larisa; Fornai, Francesco

    2015-01-01

    Amyotrophic lateral sclerosis (ALS) is characterized by massive loss of motor neurons. Data from ALS patients and experimental models indicate that mitochondria are severely damaged within dying or spared motor neurons. Nonetheless, recent data indicate that mitochondrial preservation, although preventing motor neuron loss, fails to prolong lifespan. On the other hand, the damage to motor axons plays a pivotal role in determining both lethality and disease course. Thus, in the present article each motor neuron compartment (cell body, central, and peripheral axons) of G93A SOD-1 mice was studied concerning mitochondrial alterations as well as other intracellular structures. We could confirm the occurrence of ALS-related mitochondrial damage encompassing total swelling, matrix dilution and cristae derangement along with non-pathological variations of mitochondrial size and number. However, these alterations occur to a different extent depending on motor neuron compartment. Lithium, a well-known autophagy inducer, prevents most pathological changes. However, the efficacy of lithium varies depending on which motor neuron compartment is considered. Remarkably, some effects of lithium are also evident in wild type mice. Lithium is effective also in vitro, both in cell lines and primary cell cultures from the ventral spinal cord. In these latter cells autophagy inhibition within motor neurons in vitro reproduced ALS pathology which was reversed by lithium. Muscle and glial cells were analyzed as well. Cell pathology was mostly severe within peripheral axons and muscles of ALS mice. Remarkably, when analyzing motor axons of ALS mice a subtotal clogging of axoplasm was described for the first time, which was modified under the effects of lithium. The effects induced by lithium depend on several mechanisms such as direct mitochondrial protection, induction of mitophagy and mitochondriogenesis. In this study, mitochondriogenesis induced by lithium was confirmed in situ by a

  16. EFFECTS OF FOREFOOT RUNNING ON CHRONIC EXERTIONAL COMPARTMENT SYNDROME: A CASE SERIES

    PubMed Central

    Gregory, Robert; Alitz, Curtis; Gerber, J. Parry

    2011-01-01

    Introduction: Chronic exertional compartment syndrome (CECS) is a condition that occurs almost exclusively with running whereby exercise increases intramuscular pressure compromising circulation, prohibiting muscular function, and causing pain in the lower leg. Currently, a lack of evidence exists for the effective conservative management of CECS. Altering running mechanics by adopting forefoot running as opposed to heel striking may assist in the treatment of CECS, specifically with anterior compartment symptoms. Case Description: The purpose of this case series is to describe the outcomes for subjects with CECS through a systematic conservative treatment model focused on forefoot running. Subject one was a 21 y/o female with a 4 year history of CECS and subject two was a 21 y/o male, 7 months status-post two-compartment right leg fasciotomy with a return of symptoms and a new onset of symptoms on the contralateral side. Outcome: Both subjects modified their running technique over a period of six weeks. Kinematic and kinetic analysis revealed increased step rate while step length, impulse, and peak vertical ground reaction forces decreased. In addition, leg intracompartmental pressures decreased from pre-training to post-training. Within 6 weeks of intervention subjects increased their running distance and speed absent of symptoms of CECS. Follow-up questionnaires were completed by the subjects at 7 months following intervention; subject one reported running distances up to 12.87 km pain-free and subject two reported running 6.44 km pain-free consistently 3 times a week. Discussion: This case series describes a potentially beneficial conservative management approach to CECS in the form of forefoot running instruction. Further research in this area is warranted to further explore the benefits of adopting a forefoot running technique for CECS as well as other musculoskeletal overuse complaints. PMID:22163093

  17. Metabolic coupling in urothelial bladder cancer compartments and its correlation to tumor aggressiveness

    PubMed Central

    Afonso, Julieta; Santos, Lúcio L.; Morais, António; Amaro, Teresina; Longatto-Filho, Adhemar; Baltazar, Fátima

    2016-01-01

    abstract Monocarboxylate transporters (MCTs) are vital for intracellular pH homeostasis by extruding lactate from highly glycolytic cells. These molecules are key players of the metabolic reprogramming of cancer cells, and evidence indicates a potential contribution in urothelial bladder cancer (UBC) aggressiveness and chemoresistance. However, the specific role of MCTs in the metabolic compartmentalization within bladder tumors, namely their preponderance on the tumor stroma, remains to be elucidated. Thus, we evaluated the immunoexpression of MCTs in the different compartments of UBC tissue samples (n = 111), assessing the correlations among them and with the clinical and prognostic parameters. A significant decrease in positivity for MCT1 and MCT4 occurred from normoxic toward hypoxic regions. Significant associations were found between the expression of MCT4 in hypoxic tumor cells and in the tumor stroma. MCT1 staining in normoxic tumor areas, and MCT4 staining in hypoxic regions, in the tumor stroma and in the blood vessels were significantly associated with UBC aggressiveness. MCT4 concomitant positivity in hypoxic tumor cells and in the tumor stroma, as well as positivity in each of these regions concomitant with MCT1 positivity in normoxic tumor cells, was significantly associated with an unfavourable clinicopathological profile, and predicted lower overall survival rates among patients receiving platinum-based chemotherapy. Our results point to the existence of a multi-compartment metabolic model in UBC, providing evidence of a metabolic coupling between catabolic stromal and cancer cells’ compartments, and the anabolic cancer cells. It is urgent to further explore the involvement of this metabolic coupling in UBC progression and chemoresistance. PMID:26636903

  18. Compartment-dependent mitochondrial alterations in experimental ALS, the effects of mitophagy and mitochondriogenesis

    PubMed Central

    Natale, Gianfranco; Lenzi, Paola; Lazzeri, Gloria; Falleni, Alessandra; Biagioni, Francesca; Ryskalin, Larisa; Fornai, Francesco

    2015-01-01

    Amyotrophic lateral sclerosis (ALS) is characterized by massive loss of motor neurons. Data from ALS patients and experimental models indicate that mitochondria are severely damaged within dying or spared motor neurons. Nonetheless, recent data indicate that mitochondrial preservation, although preventing motor neuron loss, fails to prolong lifespan. On the other hand, the damage to motor axons plays a pivotal role in determining both lethality and disease course. Thus, in the present article each motor neuron compartment (cell body, central, and peripheral axons) of G93A SOD-1 mice was studied concerning mitochondrial alterations as well as other intracellular structures. We could confirm the occurrence of ALS-related mitochondrial damage encompassing total swelling, matrix dilution and cristae derangement along with non-pathological variations of mitochondrial size and number. However, these alterations occur to a different extent depending on motor neuron compartment. Lithium, a well-known autophagy inducer, prevents most pathological changes. However, the efficacy of lithium varies depending on which motor neuron compartment is considered. Remarkably, some effects of lithium are also evident in wild type mice. Lithium is effective also in vitro, both in cell lines and primary cell cultures from the ventral spinal cord. In these latter cells autophagy inhibition within motor neurons in vitro reproduced ALS pathology which was reversed by lithium. Muscle and glial cells were analyzed as well. Cell pathology was mostly severe within peripheral axons and muscles of ALS mice. Remarkably, when analyzing motor axons of ALS mice a subtotal clogging of axoplasm was described for the first time, which was modified under the effects of lithium. The effects induced by lithium depend on several mechanisms such as direct mitochondrial protection, induction of mitophagy and mitochondriogenesis. In this study, mitochondriogenesis induced by lithium was confirmed in situ by a

  19. Electrowinning process with electrode compartment to avoid contamination of electrolyte

    SciTech Connect

    Poa, D.S.; Pierce, R.D.; Mulcahey, T.P.; Johnson, G.K.

    1991-12-31

    An electrolytic process and apparatus for reducing calcium oxide in a molten electrolyte of CaCl{sub 2}-CaF{sub 2} with a graphite anode in which particles or other contamination from the anode is restricted by the use of a porous barrier in the form of a basket surrounding the anode which may be removed from the electrolyte to burn the graphite particles, and wherein the calcium oxide feed is introduced to the anode compartment to increase the oxygen ion concentration at the anode.

  20. Acute Compartment Syndrome in Orthopedics: Causes, Diagnosis, and Management

    PubMed Central

    Raza, Hasnain; Mahapatra, Anant

    2015-01-01

    Almost all orthopaedic surgeons come across acute compartment syndrome (ACS) in their clinical practice. Diagnosis of ACS mostly relies on clinical findings. If the diagnosis is missed and left untreated, it can lead to serious consequences which can endanger limb and life of the patient and also risk the clinician to face lawsuits. This review article highlights the characteristic features of ACS which will help an orthopaedic surgeon to understand the pathophysiology, natural history, high risk patients, diagnosis, and surgical management of the condition. PMID:25688303

  1. Relevance of mangled extremity severity score to compartment syndromes.

    PubMed

    Uslu, M M; Altun, N S; Cila, E; Atik, O S

    1995-01-01

    This study investigated the relevance of a mangled extremity severity score (MESS) to the evaluation of intracompartmental pressure in injured patients. We measured intracompartmental pressures with a modification of the Whitesides method and compared these values with MESS in 27 patients after trauma. For 5 of them fasciotomy was necessary to relieve high intracompartmental pressures. In our series MESS seemed to correlate with intracompartmental pressure values (r = 0.733, P < 0.05). We conclude that the MESS system provides objective criteria in determining the risk of a compartment syndrome.

  2. Internalized compartments encapsulated nanogels for targeted drug delivery

    NASA Astrophysics Data System (ADS)

    Yu, Jicheng; Zhang, Yuqi; Sun, Wujin; Wang, Chao; Ranson, Davis; Ye, Yanqi; Weng, Yuyan; Gu, Zhen

    2016-04-01

    Drug delivery systems inspired by natural particulates hold great promise for targeted cancer therapy. An endosome formed by internalization of plasma membrane has a massive amount of membrane proteins and receptors on the surface, which is able to specifically target the homotypic cells. Herein, we describe a simple method to fabricate an internalized compartments encapsulated nanogel with endosome membrane components (EM-NG) from source cancer cells. Following intracellular uptake of methacrylated hyaluronic acid (m-HA) adsorbed SiO2/Fe3O4 nanoparticles encapsulating a crosslinker and a photoinitiator, EM-NG was readily prepared through in situ crosslinking initiated under UV irradiation after internalization. The resulting nanogels loaded with doxorubicin (DOX) displayed enhanced internalization efficiency to the source cells through a specific homotypic affinity in vitro. However, when treated with the non-source cells, the EM-NGs exhibited insignificant difference in therapeutic efficiency compared to a bare HA nanogel with DOX. This study illustrates the potential of utilizing an internalized compartments encapsulated formulation for targeted cancer therapy, and offers guidelines for developing a natural particulate-inspired drug delivery system.Drug delivery systems inspired by natural particulates hold great promise for targeted cancer therapy. An endosome formed by internalization of plasma membrane has a massive amount of membrane proteins and receptors on the surface, which is able to specifically target the homotypic cells. Herein, we describe a simple method to fabricate an internalized compartments encapsulated nanogel with endosome membrane components (EM-NG) from source cancer cells. Following intracellular uptake of methacrylated hyaluronic acid (m-HA) adsorbed SiO2/Fe3O4 nanoparticles encapsulating a crosslinker and a photoinitiator, EM-NG was readily prepared through in situ crosslinking initiated under UV irradiation after internalization. The

  3. Electrowinning process with electrode compartment to avoid contamination of electrolyte

    DOEpatents

    Poa, Davis S.; Pierce, R. Dean; Mulcahey, Thomas P.; Johnson, Gerald K.

    1993-01-01

    An electrolytic process and apparatus for reducing calcium oxide in a molten electrolyte of CaCl.sub.2 -CaF.sub.2 with a graphite anode in which particles or other contamination from the anode is restricted by the use of a porous barrier in the form of a basket surrounding the anode which may be removed from the electrolyte to burn the graphite particles, and wherein the calcium oxide feed is introduced to the anode compartment to increase the oxygen ion concentration at the anode.

  4. Acute Compartment Syndrome of the Thigh in Combat Casualties

    DTIC Science & Technology

    2013-03-01

    mechanisms such as motor vehicle trauma (1), femur fracture (2, 3), blunt vascular injury (4), and contusion (5, 6); (b) compressive mechanisms of injury...anesthesia (12); (c) internal hemorrhage or fluid extravasation such as coagulopathy and intramuscular hematoma (13, 14), false aneurysm (15), hamstring...Ipsilateral Femur Fracture Bilateral Compartment Syndromes ISS ½ 25 Nonsurvivors (n D 7) 42.4 š 8.6 70.1 š 5.6 0% (0/7) 86% (6/7) 100% (7/7

  5. Surgical management of abdominal compartment syndrome; indications and techniques

    PubMed Central

    Leppäniemi, Ari

    2009-01-01

    The indications for surgical decompression of abdominal compartment syndrome (ACS) are not clearly defined, but undoubtedly some patients benefit from it. In patients without recent abdominal incisions, it can be achieved with full-thickness laparostomy (either midline, or transverse subcostal) or through a subcutaneous linea alba fasciotomy. In spite of the improvement in physiological variables and significant decrease in IAP, however, the effects of surgical decompression on organ function and outcome are less clear. Because of the significant morbidity associated with surgical decompression and the management of the ensuing open abdomen, more research is needed to better define the appropriate indications and techniques for surgical intervention. PMID:19366442

  6. Dynamic GLUT4 sorting through a syntaxin-6 compartment in muscle cells is derailed by insulin resistance-causing ceramide.

    PubMed

    Foley, Kevin P; Klip, Amira

    2014-04-04

    GLUT4 constitutively recycles between the plasma membrane and intracellular depots. Insulin shifts this dynamic equilibrium towards the plasma membrane by recruiting GLUT4 to the plasma membrane from insulin-responsive vesicles. Muscle is the primary site for dietary glucose deposition; however, how GLUT4 sorts into insulin-responsive vesicles, and if and how insulin resistance affects this process, is unknown. In L6 myoblasts stably expressing myc-tagged GLUT4, we analyzed the intracellular itinerary of GLUT4 as it internalizes from the cell surface and examined if such sorting is perturbed by C2-ceramide, a lipid metabolite causing insulin resistance. Surface-labeled GLUT4myc that internalized for 30 min accumulated in a Syntaxin-6 (Stx6)- and Stx16-positive perinuclear sub-compartment devoid of furin or internalized transferrin, and displayed insulin-responsive re-exocytosis. C2-ceramide dispersed the Stx6-positive sub-compartment and prevented insulin-responsive re-exocytosis of internalized GLUT4myc, even under conditions not affecting insulin-stimulated signaling towards Akt. Microtubule disruption with nocodazole prevented pre-internalized GLUT4myc from reaching the Stx6-positive perinuclear sub-compartment and from undergoing insulin-responsive exocytosis. Removing nocodazole allowed both parameters to recover, suggesting that the Stx6-positive perinuclear sub-compartment was required for GLUT4 insulin-responsiveness. Accordingly, Stx6 knockdown inhibited by ∼50% the ability of internalized GLUT4myc to undergo insulin-responsive re-exocytosis without altering its overall perinuclear accumulation. We propose that Stx6 defines the insulin-responsive compartment in muscle cells. Our data are consistent with a model where ceramide could cause insulin resistance by altering intracellular GLUT4 sorting.

  7. Dynamic GLUT4 sorting through a syntaxin-6 compartment in muscle cells is derailed by insulin resistance-causing ceramide

    PubMed Central

    Foley, Kevin P.; Klip, Amira

    2014-01-01

    ABSTRACT GLUT4 constitutively recycles between the plasma membrane and intracellular depots. Insulin shifts this dynamic equilibrium towards the plasma membrane by recruiting GLUT4 to the plasma membrane from insulin-responsive vesicles. Muscle is the primary site for dietary glucose deposition; however, how GLUT4 sorts into insulin-responsive vesicles, and if and how insulin resistance affects this process, is unknown. In L6 myoblasts stably expressing myc-tagged GLUT4, we analyzed the intracellular itinerary of GLUT4 as it internalizes from the cell surface and examined if such sorting is perturbed by C2-ceramide, a lipid metabolite causing insulin resistance. Surface-labeled GLUT4myc that internalized for 30 min accumulated in a Syntaxin-6 (Stx6)- and Stx16-positive perinuclear sub-compartment devoid of furin or internalized transferrin, and displayed insulin-responsive re-exocytosis. C2-ceramide dispersed the Stx6-positive sub-compartment and prevented insulin-responsive re-exocytosis of internalized GLUT4myc, even under conditions not affecting insulin-stimulated signaling towards Akt. Microtubule disruption with nocodazole prevented pre-internalized GLUT4myc from reaching the Stx6-positive perinuclear sub-compartment and from undergoing insulin-responsive exocytosis. Removing nocodazole allowed both parameters to recover, suggesting that the Stx6-positive perinuclear sub-compartment was required for GLUT4 insulin-responsiveness. Accordingly, Stx6 knockdown inhibited by ∼50% the ability of internalized GLUT4myc to undergo insulin-responsive re-exocytosis without altering its overall perinuclear accumulation. We propose that Stx6 defines the insulin-responsive compartment in muscle cells. Our data are consistent with a model where ceramide could cause insulin resistance by altering intracellular GLUT4 sorting. PMID:24705014

  8. Output feedback sliding mode control for a linear multi-compartment lung mechanics system

    NASA Astrophysics Data System (ADS)

    Hou, Saing Paul; Meskin, Nader; Haddad, Wassim M.

    2014-10-01

    In this paper, we develop a sliding mode control architecture to control lung volume and minute ventilation in the presence of modelling system uncertainties. Since the applied input pressure to the lungs is, in general, nonnegative and cannot be arbitrarily large, as not to damage the lungs, a sliding mode control with bounded nonnegative control inputs is proposed. The controller only uses output information (i.e., the total volume of the lungs) and automatically adjusts the applied input pressure so that the system is able to track a given reference signal in the presence of parameter uncertainty (i.e., modelling uncertainty of the lung resistances and lung compliances) and system disturbances. Controllers for both matched and unmatched uncertainties are presented. Specifically, a Lyapunov-based approach is presented for the stability analysis of the system and the proposed control framework is applied to a two-compartment lung model to show the efficacy of the proposed control method.

  9. Compartment Syndrome as a Result of Systemic Capillary Leak Syndrome

    PubMed Central

    D'Egidio, Gianni; Wan, Cynthia; Baxter, Alan; Rosenberg, Hans

    2016-01-01

    Objective. To describe a single case of Systemic Capillary Leak Syndrome (SCLS) with a rare complication of compartment syndrome. Patient. Our patient is a 57-year-old male, referred to our hospital due to polycythemia (hemoglobin (Hgb) of 220 g/L), hypotension, acute renal failure, and bilateral calf pain. Measurements and Main Results. The patient required bilateral forearm, thigh, and calf fasciotomies during his ICU stay and continuous renal replacement therapy was instituted following onset of acute renal failure and oliguria. Ongoing hemodynamic (Norepinephrine and Milrinone infusion) and respiratory (ventilator) support in the ICU was provided until resolution of intravascular fluid extravasation. Conclusions. SCLS is an extremely rare disorder characterized by unexplained episodic capillary hyperpermeability, which causes shift of volume and protein from the intravascular space to the interstitial space. Patients present with significant hypotension, hemoconcentration, hypovolemia, and oliguria. Severe edema results from leakage of fluid and proteins into tissue. The most important part of treatment is maintaining stable hemodynamics, ruling out other causes of shock and diligent monitoring for complications. Awareness of the clinical syndrome with the rare complication of compartment syndrome may help guide investigations and diagnoses of these critically ill patients. PMID:27688917

  10. Fire safety evaluation of aircraft lavatory and cargo compartments

    NASA Technical Reports Server (NTRS)

    Kourtides, D. A.; Parker, J. A.; Hilado, C. J.; Anderson, R. A.; Tustin, E.; Arnold, D. B.; Gaume, J. G.; Binding, A. T.; Mikeska, J. L.

    1976-01-01

    A program of experimental fires has been carried out to assess fire containment and other fire hazards in lavatory and cargo compartments of wide-body jet aircraft by evaluation of ignition time, burn-through time, fire spread rate, smoke density, evolution of selected combustible and toxic gases, heat flux, and detector response. Two tests were conducted: one involving a standard Boeing 747 lavatory and one involving a simulated DC-10 cargo compartment. A production lavatory module was furnished with conventional materials and was installed in an enclosure. The ignition load was four polyethylene bags containing paper and plastic waste materials representive of a maximum flight cabin waste load. Standard aircraft ventilation conditions were utilized and the lavatory door was closed during the test. Lavatory wall and ceiling panels contained the fire spread during the 30-minute test. Smoke was driven into the enclosure primarily through the ventilation grille in the door and through the gaps between the bifold door and the jamb where the door distorted from the heat earlier in the test. The interior of the lavatory was almost completely destroyed by the fire.

  11. Delayed Presentation of Gluteal Compartment Syndrome: The Argument for Fasciotomy

    PubMed Central

    Lawrence, John E.; Cundall-Curry, Duncan J.; Stohr, Kuldeep K.

    2016-01-01

    A male patient in his fifties presented to his local hospital with numbness and weakness of the right leg which left him unable to mobilise. He reported injecting heroin the previous morning. Following an initial diagnosis of acute limb ischaemia the patient was transferred to a tertiary centre where Computed Tomography Angiography was reported as normal. Detailed neurological examination revealed weakness in hip flexion and extension (1/5 on the Medical Research Council scale) with complete paralysis of muscle groups distal to this. Sensation to pinprick and light touch was globally reduced. Blood tests revealed acute kidney injury with raised creatinine kinase and the patient was treated for rhabdomyolysis. Orthopaedic referral was made the following day and a diagnosis of gluteal compartment syndrome (GCS) was made. Emergency fasciotomy was performed 56 hours after the onset of symptoms. There was immediate neurological improvement following decompression and the patient was rehabilitated with complete nerve recovery and function at eight-week follow-up. This is the first documented case of full functional recovery following a delayed presentation of GCS with sciatic nerve palsy. We discuss the arguments for and against fasciotomy in cases of compartment syndrome with significant delay in presentation or diagnosis. PMID:27073707

  12. Involvement of the mitochondrial compartment in human NCL fibroblasts

    SciTech Connect

    Pezzini, Francesco; Gismondi, Floriana; Tessa, Alessandra; Tonin, Paola; Carrozzo, Rosalba; Mole, Sara E.; Santorelli, Filippo M.; Simonati, Alessandro

    2011-12-09

    Highlights: Black-Right-Pointing-Pointer Mitochondrial reticulum fragmentation occurs in human CLN1 and CLN6 fibroblasts. Black-Right-Pointing-Pointer Likewise mitochondrial shift-to periphery and decreased mitochondrial density are seen. Black-Right-Pointing-Pointer Enhanced caspase-mediated apoptosis occurs following STS treatment in CLN1 fibroblasts. -- Abstract: Neuronal ceroid lipofuscinosis (NCL) are a group of progressive neurodegenerative disorders of childhood, characterized by the endo-lysosomal storage of autofluorescent material. Impaired mitochondrial function is often associated with neurodegeneration, possibly related to the apoptotic cascade. In this study we investigated the possible effects of lysosomal accumulation on the mitochondrial compartment in the fibroblasts of two NCL forms, CLN1 and CLN6. Fragmented mitochondrial reticulum was observed in all cells by using the intravital fluorescent marker Mitotracker, mainly in the perinuclear region. This was also associated with intense signal from the lysosomal markers Lysotracker and LAMP2. Likewise, mitochondria appeared to be reduced in number and shifted to the cell periphery by electron microscopy; moreover the mitochondrial markers VDCA and COX IV were reduced following quantitative Western blot analysis. Whilst there was no evidence of increased cell death under basal condition, we observed a significant increase in apoptotic nuclei following Staurosporine treatment in CLN1 cells only. In conclusion, the mitochondrial compartment is affected in NCL fibroblasts invitro, and CLN1 cells seem to be more vulnerable to the negative effects of stressed mitochondrial membrane than CLN6 cells.

  13. Medulloblastoma subgroups remain stable across primary and metastatic compartments.

    PubMed

    Wang, Xin; Dubuc, Adrian M; Ramaswamy, Vijay; Mack, Stephen; Gendoo, Deena M A; Remke, Marc; Wu, Xiaochong; Garzia, Livia; Luu, Betty; Cavalli, Florence; Peacock, John; López, Borja; Skowron, Patryk; Zagzag, David; Lyden, David; Hoffman, Caitlin; Cho, Yoon-Jae; Eberhart, Charles; MacDonald, Tobey; Li, Xiao-Nan; Van Meter, Timothy; Northcott, Paul A; Haibe-Kains, Benjamin; Hawkins, Cynthia; Rutka, James T; Bouffet, Eric; Pfister, Stefan M; Korshunov, Andrey; Taylor, Michael D

    2015-03-01

    Medulloblastoma comprises four distinct molecular variants with distinct genetics, transcriptomes, and outcomes. Subgroup affiliation has been previously shown to remain stable at the time of recurrence, which likely reflects their distinct cells of origin. However, a therapeutically relevant question that remains unanswered is subgroup stability in the metastatic compartment. We assembled a cohort of 12-paired primary-metastatic tumors collected in the MAGIC consortium, and established their molecular subgroup affiliation by performing integrative gene expression and DNA methylation analysis. Frozen tissues were collected and profiled using Affymetrix gene expression arrays and Illumina methylation arrays. Class prediction and hierarchical clustering were performed using existing published datasets. Our molecular analysis, using consensus integrative genomic data, establishes the unequivocal maintenance of molecular subgroup affiliation in metastatic medulloblastoma. We further validated these findings by interrogating a non-overlapping cohort of 19 pairs of primary-metastatic tumors from the Burdenko Neurosurgical Institute using an orthogonal technique of immunohistochemical staining. This investigation represents the largest reported primary-metastatic paired cohort profiled to date and provides a unique opportunity to evaluate subgroup-specific molecular aberrations within the metastatic compartment. Our findings further support the hypothesis that medulloblastoma subgroups arise from distinct cells of origin, which are carried forward from ontogeny to oncology.

  14. Characterization of a Novel Prevacuolar Compartment in Neurospora crassa

    PubMed Central

    Draskovic, Marija; Schnittker, Robert R.; El-Mellouki, Tarik; Plamann, Michael D.; Sánchez-León, Eddy; Riquelme, Meritxell; Bowman, Emma Jean

    2015-01-01

    Using confocal microscopy, we observed ring-like organelles, similar in size to nuclei, in the hyphal tip of the filamentous fungus Neurospora crassa. These organelles contained a subset of vacuolar proteins. We hypothesize that they are novel prevacuolar compartments (PVCs). We examined the locations of several vacuolar enzymes and of fluorescent compounds that target the vacuole. Vacuolar membrane proteins, such as the vacuolar ATPase (VMA-1) and the polyphosphate polymerase (VTC-4), were observed in the PVCs. A pigment produced by adenine auxotrophs, used to visualize vacuoles, also accumulated in PVCs. Soluble enzymes of the vacuolar lumen, alkaline phosphatase and carboxypeptidase Y, were not observed in PVCs. The fluorescent molecule Oregon Green 488 carboxylic acid diacetate, succinimidyl ester (carboxy-DFFDA) accumulated in vacuoles and in a subset of PVCs, suggesting maturation of PVCs from the tip to distal regions. Three of the nine Rab GTPases in N. crassa, RAB-2, RAB-4, and RAB-7, localized to the PVCs. RAB-2 and RAB-4, which have similar amino acid sequences, are present in filamentous fungi but not in yeasts, and no function has previously been reported for these Rab GTPases in fungi. PVCs are highly pleomorphic, producing tubular projections that subsequently become detached. Dynein and dynactin formed globular clusters enclosed inside the lumen of PVCs. The size, structure, dynamic behavior, and protein composition of the PVCs appear to be significantly different from those of the well-studied prevacuolar compartment of yeasts. PMID:26453652

  15. Compartment specific response of antioxidants to drought stress in Arabidopsis

    PubMed Central

    Koffler, Barbara Eva; Luschin-Ebengreuth, Nora; Stabentheiner, Edith; Müller, Maria; Zechmann, Bernd

    2014-01-01

    Compartment specific changes in ascorbate and glutathione contents were studied during drought stress in Arabidopsis thaliana Col-0 and in ascorbate and glutathione deficient mutants vtc2-1 and pad2-1, respectively, over a time period of 10 days. The results of this study revealed a strong decrease of glutathione contents in both mutants (up to 52% in mitochondria of pad2-1 and 40% in nuclei of vtc2-1) at early time points when drought stress was not yet measurable in leaves even though the soil showed a drop in relative water contents. These results indicate that glutathione is used at early time points to signal drought stress from roots to leaves. Such roles could not be confirmed for ascorbate which remained unchanged in most cell compartments until very late stages of drought. During advanced drought stress the strong depletion of ascorbate and glutathione in chloroplasts (up to 50% in Col-0 and vtc2-1) and peroxisomes (up to 56% in Col-0) could be correlated with a strong accumulation of H2O2. The strong increase of H2O2 and ascorbate in vacuoles (up to 111%) in wildtype plants indicates that ascorbate plays an important role for the detoxification of ROS in vacuoles during drought stress. PMID:25219315

  16. Viable Biomass Sensor integration in the MELiSSA CI and CIII compartments

    NASA Astrophysics Data System (ADS)

    Duatis Juarez, Jordi; Peiro, Enrique; Bragos, Ramon

    Traditionally, the biomass quantity and quality in complex substrate reactor (e.g. activated sludge, high density, fixed bed,..) is determined off-line in laboratories. Within this study, the VIAMASS Sensor System, which uses Electrical Impedance Spectroscopy (EIS) techniques, has been tested for MELiSSA compartment CI and C III, the liquefying and the nitrifying compartment respectively. This sensor is able to measure viable cells on basis of an impedance spectroscopy measurement. The fact that viable biomass can be detected, distinguishes the sensor from classical biomass sensors used in wastewater treatment plants. Detection of viable biomass and composition of the biomass can be very useful for calibration and validation of biological models. The sensor can be used to detect toxicity in system leading to die-off of organisms. The technology developed initially for space applications has been adapted and will be also able to give overall information on the population distribution of cells, distinguishing what type of biomass is dominant (for example, bacteria or protozoa).

  17. Hedgehog signaling maintains a tumor stem cell compartment in multiple myeloma.

    PubMed

    Peacock, Craig D; Wang, Qiuju; Gesell, Gregory S; Corcoran-Schwartz, Ian M; Jones, Evan; Kim, Jynho; Devereux, Wendy L; Rhodes, Jonathan T; Huff, Carol A; Beachy, Philip A; Watkins, D Neil; Matsui, William

    2007-03-06

    The cancer stem cell hypothesis suggests that malignant growth depends on a subset of tumor cells with stem cell-like properties of self-renewal. Because hedgehog (Hh) signaling regulates progenitor cell fate in normal development and homeostasis, aberrant pathway activation might be involved in the maintenance of such a population in cancer. Indeed, mutational activation of the Hh pathway is associated with medulloblastoma and basal cell carcinoma; pathway activity is also critical for growth of other tumors lacking such mutations, although the mechanism of pathway activation is poorly understood. Here we study the role and mechanism of Hh pathway activation in multiple myeloma (MM), a malignancy with a well defined stem cell compartment. In this model, rare malignant progenitors capable of clonal expansion resemble B cells, whereas the much larger tumor cell population manifests a differentiated plasma cell phenotype that pathologically defines the disease. We show that the subset of MM cells that manifests Hh pathway activity is markedly concentrated within the tumor stem cell compartment. The Hh ligand promotes expansion of MM stem cells without differentiation, whereas the Hh pathway blockade, while having little or no effect on malignant plasma cell growth, markedly inhibits clonal expansion accompanied by terminal differentiation of purified MM stem cells. These data reveal that Hh pathway activation is heterogeneous across the spectrum of MM tumor stem cells and their more differentiated progeny. The potential existence of similar relationships in other adult cancers may have important biologic and clinical implications for the study of aberrant Hh signaling.

  18. Particle-macrophage relationships during the clearance of particles from the alveolar macrophage compartment

    SciTech Connect

    Lehnert, B.E.; Toevs, K.E.; Valdez, Y.E.; Sebring, R.J.

    1988-11-01

    In this study, we quantitatively characterized the distributions of particles among lavageable AM over a 30 day period after the acute intratracheal instillation of /approximately/3 mg of 1.9 ..mu..m dia. polystyrene microspheres into the lungs of rats. Information obtained for particles retained in the lavageable AM compartment and particle-AM distribution data were collectively examined using a simple, first order kinetic model for AM removal from the lung. The results of our analyses suggest that a volume load of particles in a macrophage up to at least /approximately/450 ..mu..m/sup 3/ does not inhibit the mobilization of macrophages from the alveolar compartment. Additionally, the kinetic analyses of the particle-macrophage distributions suggest that macrophages that replenish those AM that are translocated from the lung on a continual basis during alveolar clearance are not and/or do not remain particle-free in the alveoli. This latter observation can be explained by: (1) the influx of particle-bearing macrophages into the alveoli, or (2) the in situ proliferation of particle bearing AM, or (3) the release of particles by AM and the subsequent phagocytosis of the particles by newly arrived cells, or (4) a combination of these possibilities. 32 refs., 7 figs., 1 tab.

  19. Optical oximetry of volume-oscillating vascular compartments: contributions from oscillatory blood flow

    NASA Astrophysics Data System (ADS)

    Kainerstorfer, Jana M.; Sassaroli, Angelo; Fantini, Sergio

    2016-10-01

    We present a quantitative analysis of dynamic diffuse optical measurements to obtain oxygen saturation of hemoglobin in volume oscillating compartments. We used a phasor representation of oscillatory hemodynamics at the heart rate and respiration frequency to separate the oscillations of tissue concentrations of oxyhemoglobin (O) and deoxyhemoglobin (D) into components due to blood volume (subscript V) and blood flow (subscript F): O=OV+OF, D=DV+DF. This is achieved by setting the phase angle Arg(OF)-Arg(O), which can be estimated by a hemodynamic model that we recently developed. We found this angle to be -72 deg for the cardiac pulsation at 1 Hz, and -7 deg for paced breathing at 0.1 Hz. Setting this angle, we can obtain the oxygen saturation of hemoglobin of the volume-oscillating vascular compartment, SV=|OV|/(|OV|+|DV|). We demonstrate this approach with cerebral near-infrared spectroscopy measurements on healthy volunteers at rest (n=4) and during 0.1 Hz paced breathing (n=3) with a 24-channel system. Rest data at the cardiac frequency were used to calculate the arterial saturation, S(a); over all subjects and channels, we found ==0.96±0.02. In the case of paced breathing, we found =0.66±0.14, which reflects venous-dominated hemodynamics at the respiratory frequency.

  20. Surviving space flight: case study on MELiSSA's CIII nitrifying compartment

    NASA Astrophysics Data System (ADS)

    Ilgrande, Chiara; Lasseur, Christophe; Mastroleo, Felice; Paille, Christel; Leys, Natalie; Morozova, Julia; Ilyin, Vyacheslav; Clauwaert, Peter; Christiaens, Marlies E. R.; Lindeboom, Ralph E. F.; Vlaeminck, Siegfried; Prat, Delphine; Arroyo, Jose M. C.; Conincx, Ilse; Van Hoey, Olivier; Roume, Hugo; Udert, Kai; Sas, Benedikt

    2016-07-01

    Space synthetic biology offers key opportunities for long-term space missions. Planets mining, terraformation, space medicine and Life Support technologies would all benefit from an integrative biological approach. However, space is a harsh environment for life: microgravity, temperature, UV and cosmic radiation can affect the health and functionality of microorganisms and plants, possibly preventing the optimal performance of the systems. The European Space Agency's Life Support System (MELiSSA) has been developed as a model for future long term Space missions and Space habitation. MELiSSA is a 5 compartment artificial ecosystem with microorganisms and higher, that aims at completely recycling gas, liquid and solid waste. In this study, the survival and functional activity after Lower Earth Orbit conditions of microbial nitrogen conversions, relevant for MELiSSA's CIII compartment, was tested. Synthetic communities containing Nitrosomonas europeae, Nitrosomonas ureae, Nitrobacter winogradskyi, Nitrospira moscoviensis and Cupriavidus pinatubonensis were exposed to the Lower Earth Orbit conditions of the International Space Station (ISS) for 7 days. Nitrosomonas europeae, Nitrobacter winogradskyi, Cupriavidus pinatubonensis, and three mixed communities (a urine nitrification sludge, a sludge containing aerobic ammonia oxidizing bacteria and anammox bacteria (OLAND), and an aquaculture sludge containing ammonia oxidizing archaea) were exposed to Lower Earth Orbit conditions for 44 days. Survival after both space flights was demonstrated because nitritation, nitratation, denitrification and anammox activity could be restored at a rate comparable to ground storage conditions. Our results validate the potential survival feasibility and suggest future space applications for N-related microorganisms.

  1. Estimation of adipose compartment volumes in CT images of a mastectomy specimen

    NASA Astrophysics Data System (ADS)

    Imran, Abdullah-Al-Zubaer; Pokrajac, David D.; Maidment, Andrew D. A.; Bakic, Predrag R.

    2016-03-01

    Anthropomorphic software breast phantoms have been utilized for preclinical quantitative validation of breast imaging systems. Efficacy of the simulation-based validation depends on the realism of phantom images. Anatomical measurements of the breast tissue, such as the size and distribution of adipose compartments or the thickness of Cooper's ligaments, are essential for the realistic simulation of breast anatomy. Such measurements are, however, not readily available in the literature. In this study, we assessed the statistics of adipose compartments as visualized in CT images of a total mastectomy specimen. The specimen was preserved in formalin, and imaged using a standard body CT protocol and high X-ray dose. A human operator manually segmented adipose compartments in reconstructed CT images using ITK-SNAP software, and calculated the volume of each compartment. In addition, the time needed for the manual segmentation and the operator's confidence were recorded. The average volume, standard deviation, and the probability distribution of compartment volumes were estimated from 205 segmented adipose compartments. We also estimated the potential correlation between the segmentation time, operator's confidence, and compartment volume. The statistical tests indicated that the estimated compartment volumes do not follow the normal distribution. The compartment volumes are found to be correlated with the segmentation time; no significant correlation between the volume and the operator confidence. The performed study is limited by the mastectomy specimen position. The analysis of compartment volumes will better inform development of more realistic breast anatomy simulation.

  2. Rab5 activity regulates GLUT4 sorting into insulin-responsive and non-insulin-responsive endosomal compartments: a potential mechanism for development of insulin resistance.

    PubMed

    Tessneer, Kandice L; Jackson, Robert M; Griesel, Beth A; Olson, Ann Louise

    2014-09-01

    Glucose transporter isoform 4 (GLUT4) is the insulin-responsive glucose transporter mediating glucose uptake in adipose and skeletal muscle. Reduced GLUT4 translocation from intracellular storage compartments to the plasma membrane is a cause of peripheral insulin resistance. Using a chronic hyperinsulinemia (CHI)-induced cell model of insulin resistance and Rab5 mutant overexpression, we determined these manipulations altered endosomal sorting of GLUT4, thus contributing to the development of insulin resistance. We found that CHI induced insulin resistance in 3T3-L1 adipocytes by retaining GLUT4 in a Rab5-activity-dependent compartment that is unable to equilibrate with the cell surface in response to insulin. Furthermore, CHI-mediated retention of GLUT4 in this non-insulin-responsive compartment impaired filling of the transferrin receptor (TfR)-positive and TfR-negative insulin-responsive storage compartments. Our data suggest that hyperinsulinemia may inhibit GLUT4 by chronically maintaining GLUT4 in the Rab5 activity-dependent endosomal pathway and impairing formation of the TfR-negative and TfR-positive insulin-responsive GLUT4 pools. This model suggests that an early event in the development of insulin-resistant glucose transport in adipose tissue is to alter the intracellular localization of GLUT4 to a compartment that does not efficiently equilibrate with the cell surface when insulin levels are elevated for prolonged periods of time.

  3. Verification of simple hydration/dehydration methods to characterize multiple water compartments on tendon type 1 collagen.

    PubMed

    Cameron, Ivan L; Short, Nicholas J; Fullerton, Gary D

    2007-06-01

    A molecular model of collagen hydration is used to validate centrifugal dehydration force (CDF) and re-hydration isotherm (RHI) methods to measure and characterize hydration compartments on bovine tendon. The CDF method assesses fluid flow rate from flexor and extensor tendons expressed in (g-water/g-dry mass-minute) and hydration capacity of compartments in (g-water/g-dry mass). Measured water compartment capacities agree with the molecular model of collagen hydration [Fullerton GD, Rahal A. Collagen structure: the molecular source of tendon magic angle effect. J Mag Reson Imag 2007;25:345-361; Fullerton GD, Amurao MR. Evidence that collagen and tendon have monolayer water coverage in the native state. Cell Biol Int 2006;30(1):56-65]. Native tendon hydration has monolayer coverage on collagen h(m)=1.6 g/g which divides into primary hydration on polar surfaces h(pp)=0.8 g/g and secondary hydration h(s)=0.8 g/g bridging over hydrophobic surfaces. Primary hydration is hydrogen bonded to collagen polar side chains h(psc)=0.54 g/g with small free energy or to the protein main chain hydration h(pmc)=0.26 g/g with greater free energy of binding. The CDF method replaces the more time consuming water proton NMR spin-lattice dehydration (NMR titration) method, confirms the presence of three non-bulk water compartments on collagen (h(pmc)=0.26 g/g, h(pp)=0.8 g/g and h(m)=1.6 g/g). This CDF method provides the most reproducible experimental measure of total tissue non-bulk water (TNBW). The re-hydration isotherm method, on the other hand, provides the most accurate measure of the Ramachandran water-bridge capacity h(Ra)=0.0656 g/g. The only equipment needed are: microfilterfuge tubes, a microcentrifuge capable of 14,000 x g or 4MPa, a vacuum drying oven, an accurate balance and curve fitting ability. The newly validated methods should be useful for characterizing multiple water compartments in biological and non-biological materials by allowing direct measurement of water

  4. Aging of microstructural compartments in human compact bone

    NASA Technical Reports Server (NTRS)

    Akkus, Ozan; Polyakova-Akkus, Anna; Adar, Fran; Schaffler, Mitchell B.

    2003-01-01

    Composition of microstructural compartments in compact bone of aging male subjects was assessed using Raman microscopy. Secondary mineralization of unremodeled fragments persisted for two decades. Replacement of these tissue fragments with secondary osteons kept mean composition constant over age, but at a fully mineralized limit. Slowing of remodeling may increase fracture susceptibility through an increase in proportion of highly mineralized tissue. In this study, the aging process in the microstructural compartments of human femoral cortical bone was investigated and related to changes in the overall tissue composition within the age range of 17-73 years. Raman microprobe analysis was used to assess the mineral content, mineral crystallinity, and carbonate substitution in fragments of primary lamellar bone that survived remodeling for decades. Tissue composition of the secondary osteonal population was investigated to determine the composition of turned over tissue volume. Finally, Raman spectral analysis of homogenized tissue was performed to evaluate the effects of unremodeled and newly formed tissue on the overall tissue composition. The chemical composition of the primary lamellar bone exhibited two chronological stages. Organic matrix became more mineralized and the crystallinity of the mineral improved during the first stage, which lasted for two decades. The mineral content and the mineral crystallinity did not vary during the second stage. The results for the primary lamellar bone demonstrated that physiological mineralization, as evidenced by crystal growth and maturation, is a continuous process that may persist as long as two decades, and the growth and maturation process stops after the organic matrix becomes "fully mineralized." The average mineral content and the average mineral crystallinity of the homogenized tissue did not change with age. It was also observed that the mineral content of the homogenized tissue was consistently greater than the

  5. Darwinian evolution in a translation-coupled RNA replication system within a cell-like compartment.

    PubMed

    Ichihashi, Norikazu; Usui, Kimihito; Kazuta, Yasuaki; Sunami, Takeshi; Matsuura, Tomoaki; Yomo, Tetsuya

    2013-01-01

    The ability to evolve is a key characteristic that distinguishes living things from non-living chemical compounds. The construction of an evolvable cell-like system entirely from non-living molecules has been a major challenge. Here we construct an evolvable artificial cell model from an assembly of biochemical molecules. The artificial cell model contains artificial genomic RNA that replicates through the translation of its encoded RNA replicase. We perform a long-term (600-generation) replication experiment using this system, in which mutations are spontaneously introduced into the RNA by replication error, and highly replicable mutants dominate the population according to Darwinian principles. During evolution, the genomic RNA gradually reinforces its interaction with the translated replicase, thereby acquiring competitiveness against selfish (parasitic) RNAs. This study provides the first experimental evidence that replicating systems can be developed through Darwinian evolution in a cell-like compartment, even in the presence of parasitic replicators.

  6. New insights on human skeletal muscle tissue compartments revealed by in vivo t2 NMR relaxometry.

    PubMed

    Araujo, Ericky C A; Fromes, Yves; Carlier, Pierre G

    2014-05-20

    The spin-spin (T2) relaxation of (1)H-NMR signals in human skeletal muscle has been previously hypothesized to reveal information about myowater compartmentation. Although experimental support has been provided, no consensus has yet emerged concerning the attribution of specific anatomical compartments to the observed T2 components. Potential application of a noninvasive tool that might offer such information urges the quest for a definitive answer to this question. The purpose of this work was to obtain new information that might help elucidate the mechanism of T2 distribution in muscle. To do so, in vivo T2 relaxation data was acquired from the soleus of eight healthy volunteers using a localized Carr-Purcell-Meiboom-Gill technique. Each acquisition contained 1000 echoes with an interecho spacing of 1 ms. Data were acquired from each subject under different vascular filling preparations expected to change exclusively the extracellular water fraction. Two exponential components were systematically observed: an intermediate component (T2 ~ 32 ms) and a long component (100 < T2 < 210 ms). The relative fraction and T2 value characterizing the long component systematically increased after progressive augmentation of extracellular water volume. Characteristic relaxation behavior for each vascular filling condition was analyzed with a two-site exchange model and a three-site two-exchange model. We show that a two-site exchange model can only predict the observations for small exchange rates, much more representative of transendothelial than transcytolemmal exchange regimes. The three-site two-exchange model representing the intracellular, interstitial, and vascular spaces was capable of precisely predicting the observations for realistic transcytolemmal and transendothelial exchange rates. The estimated intrinsic relative fractions of each of these compartments corroborate with estimations from previous works and strongly suggest that the T2 relaxation from water within

  7. Overuse injuries: tendinopathies, stress fractures, compartment syndrome, and shin splints.

    PubMed

    Wilder, Robert P; Sethi, Shikha

    2004-01-01

    Approximately 50% of all sports injuries are secondary to overuse and result from repetitive microtrauma that causes local tissue damage. Injuries are most likely with changes in mode, intensity, or duration of training and can accumulate before symptoms appear. Intrinsic factors contributing to injuries are individual bio-mechanical abnormalities such as malalignments, muscle imbalance, inflexibility, weakness, and instability. Contributing extrinsic (avoidable) factors include poor technique, improper equipment, and improper changes in duration or frequency of activity. Injuries are often related to biomechanical abnormalities removed from the specific injury site, requiring evaluation of the entire kinetic chain. This article discusses common overuse injuries of the lower leg, ankle, and foot: tendinopathies, stress fractures, chronic exertional compartment syndrome, and shin splints.

  8. Facile synthesis of dumbbell-shaped multi-compartment nanoparticles.

    PubMed

    Doermbach, Karla; Pich, Andrij

    2015-05-28

    In this article we report on the controlled synthesis of asymmetric lemon-shaped and dumbbell-shaped multi-compartment nanoparticles (MCPs) with a reactive surface and interesting morphology. In our approach we utilize partial coating of hematite ellipsoids with a hydrophobic polymer layer followed by selective silica deposition on the non-coated surface. Ellipsoidal hematite particles provide a non-centric asymmetry, which is strongly enhanced during the seeded emulsion polymerization. The asymmetric growth of polymers on the hematite particle surface is driven by phase separation phenomena, which lead to a reduction of the interfacial tension. We found the tips of the hematite ellipsoids to be uncovered after polymerization. A selective deposition of silica onto the free tips leads to dumbbell-shaped particles with hydrophilic and hydrophobic parts.

  9. Abdominal compartment syndrome following abdominoplasty: A case report and review

    PubMed Central

    Izadpanah, Arash; Izadpanah, Ali; Karunanayake, Mihiran; Petropolis, Christian; Deckelbaum, Dan L.; Luc, Mario

    2014-01-01

    Abdominoplasty is among the most commonly performed aesthetic procedures in plastic surgery. Despite high complication rate, abdominal contouring procedures are expected to rise in popularity with the advent of bariatric surgery. Patients with a history of gastric bypass surgery have an elevated incidence of small bowel obstruction from internal herniation, which is associated with non-specific upper abdominal pain, nausea, and a decrease in appetite. Internal hernias, when subjected to elevated intra-abdominal pressures, have a high-risk of developing ischemic bowel. We present a case report of patient with previous laparoscopic Roux-en-y gastric bypass who developed acute ischemic bowel leading to abdominal compartment syndrome following abdominoplasty. To the best of our knowledge, this is the first reported case in the literature. We herein emphasise on the subtle symptoms and signs that warrant further investigations in prospective patients for an abdominal contouring procedure with a prior history of gastric bypass surgery. PMID:25190927

  10. Abdominal compartment syndrome following abdominoplasty: A case report and review.

    PubMed

    Izadpanah, Arash; Izadpanah, Ali; Karunanayake, Mihiran; Petropolis, Christian; Deckelbaum, Dan L; Luc, Mario

    2014-05-01

    Abdominoplasty is among the most commonly performed aesthetic procedures in plastic surgery. Despite high complication rate, abdominal contouring procedures are expected to rise in popularity with the advent of bariatric surgery. Patients with a history of gastric bypass surgery have an elevated incidence of small bowel obstruction from internal herniation, which is associated with non-specific upper abdominal pain, nausea, and a decrease in appetite. Internal hernias, when subjected to elevated intra-abdominal pressures, have a high-risk of developing ischemic bowel. We present a case report of patient with previous laparoscopic Roux-en-y gastric bypass who developed acute ischemic bowel leading to abdominal compartment syndrome following abdominoplasty. To the best of our knowledge, this is the first reported case in the literature. We herein emphasise on the subtle symptoms and signs that warrant further investigations in prospective patients for an abdominal contouring procedure with a prior history of gastric bypass surgery.

  11. Anterior elbow dislocation with potential compartment syndrome: a case report.

    PubMed

    Queipo-de-Llano Temboury, Alfonso; Lara, Jorge Mariscal; Fernadez-de-Rota, Antonio; Queipo-de-Llano, Enrique

    2007-03-01

    Anterior elbow dislocation is an infrequent lesion, usually produced by direct trauma to the proximal ulna after a fall on the elbow in flexion, and is often associated with soft tissue injuries. The authors report a case of a complex injury produced by a high-energy trauma in the right arm of a 65-year-old patient. His limb was trapped inside an industrial spin-dryer, resulting in a closed anterior elbow dislocation, diaphyseal ulnar shaft, radial styloid process fractures, and an associated compartment syndrome. The injury mechanism and its treatment are described to better manage the soft tissue injury and early elbow mobilization using the FEARM hinged external fixator. A good result was achieved, with almost complete restoration of the patient's arm functions, and he has returned to his previous working activities.

  12. Microbial diversity in different compartments of an aquaponics system.

    PubMed

    Schmautz, Zala; Graber, Andreas; Jaenicke, Sebastian; Goesmann, Alexander; Junge, Ranka; Smits, Theo H M

    2017-01-10

    Aquaponics is a solution for sustainable production of fish and plants in a single semi-closed system, where nutrient-rich water from the aquaculture provides nutrients for plant growth. We examined the microbial communities within an experimental aquaponics system. Whereas the fish feces contained a separate community dominated by bacteria of the genus Cetobacterium, the samples from plant roots, biofilter, and periphyton were more similar to each other, while the communities were more diverse. Detailed examination of the data gave the first indications to functional groups of organisms in the different compartments of the aquaponic system. As other nitrifiers other than members of the genus Nitrospira were only present at low numbers, it was anticipated that Nitrospirae may perform the nitrification process in the biofilm.

  13. Regulation of spermatogonial stem cell compartment in the mouse testis.

    PubMed

    Iwamori, Naoki

    2014-01-01

    Spermatogenesis occurs throughout the adult lifetime of males and is supported by a robust stem cell system. Spermatogonial stem cells (SSCs) are the stem cells of postnatal male germ cells, and not only self-renew but also produce differentiated progeny continuously. Recent report revealed that differentiating spermatogonia could revert into an undifferentiated state, although it was believed that SSCs were homogeneous and that differentiating spermatogonia was not reversible. Although several molecules, which regulate SSC, have been identified so far, molecular mechanisms underlying the maintenance of SSCs as well as the reversible developmental lineage of SSCs remain to be elucidated. In this review, we describe a brief overview of spermatogenesis and summarize the molecular regulation of SSC compartment.

  14. Native tissue repair for central compartment prolapse: a narrative review.

    PubMed

    Paz-Levy, Dorit; Yohay, David; Neymeyer, Joerg; Hizkiyahu, Ranit; Weintraub, Adi Y

    2017-02-01

    Central descent due to a level 1 defect is a main component in pelvic organ prolapse (POP) reconstructive surgery, whether for symptomatic apical prolapse or for the prolapse repair of other compartments. A recent growth in the rate of native tissue repair procedures for POP, following the US Food and Drug Administration (FDA) warnings regarding the safety and efficacy of synthetic meshes, requires a re-evaluation of these procedures. The safety, efficacy, and determination of the optimal surgical approach should be the center of attention. Functional outcome measures and patient-centered results have lately gained importance and received focus. A comprehensive literature review was performed to evaluate objective and subjective outcomes of apical prolapse native tissue repair, with a special focus on studies reporting impact on patients' functional outcomes, quality of life, and satisfaction. We performed a MEDLINE search for articles in the English language by using the following key words: apical prolapse, sacrospinous ligament fixation, uterosacral ligament suspension, sacral colpopexy, McCall culdoplasty, iliococcygeus vaginal fixation, and functional outcomes. We reviewed references as well. Despite a prominent shortage of studies reporting standardized prospective outcomes for native tissue repair interventions, we noted a high rate of safety and efficacy, with a low complication rate for most procedures and low recurrence or re-treatment rates. The objective and subjective results of different procedures are reviewed. Functional outcomes of native tissue repair procedures have not been studied sufficiently, though existing data present those procedures as favorable and not categorically inferior to sacrocolpopexy. Apical compartment prolapse repair using native tissue is not a compromise. Functional outcomes of native tissue repair procedures are favorable, have a high rate of success, improve women's quality of life (QoL), and result in high rates of

  15. Management of abdominal compartment syndrome after transurethral resection of the prostate.

    PubMed

    Gaut, Megan M; Ortiz, Jaime

    2015-01-01

    Acute abdominal compartment syndrome is most commonly associated with blunt abdominal trauma, although it has been seen after ruptured abdominal aortic aneurysm, liver transplantation, pancreatitis, and massive volume resuscitation. Acute abdominal compartment syndrome develops once the intra-abdominal pressure increases to 20-25 mmHg and is characterized by an increase in airway pressures, inadequate ventilation and oxygenation, altered renal function, and hemodynamic instability. This case report details the development of acute abdominal compartment syndrome during transurethral resection of the prostate with extra- and intraperitoneal bladder rupture under general anesthesia. The first signs of acute abdominal compartment syndrome in this patient were high peak airway pressures and difficulty delivering tidal volumes. Management of the compartment syndrome included re-intubation, emergent exploratory laparotomy, and drainage of irrigation fluid. Difficulty with ventilation should alert the anesthesiologist to consider abdominal compartment syndrome high in the list of differential diagnoses during any endoscopic bladder or bowel case.

  16. [Management of abdominal compartment syndrome after transurethral resection of the prostate].

    PubMed

    Gaut, Megan M; Ortiz, Jaime

    2015-01-01

    Acute abdominal compartment syndrome is most commonly associated with blunt abdominal trauma, although it has been seen after ruptured abdominal aortic aneurysm, liver transplantation, pancreatitis, and massive volume resuscitation. Acute abdominal compartment syndrome develops once the intra-abdominal pressure increases to 20-25mmHg and is characterized by an increase in airway pressures, inadequate ventilation and oxygenation, altered renal function, and hemodynamic instability. This case report details the development of acute abdominal compartment syndrome during transurethral resection of the prostate with extra- and intraperitoneal bladder rupture under general anesthesia. The first signs of acute abdominal compartment syndrome in this patient were high peak airway pressures and difficulty delivering tidal volumes. Management of the compartment syndrome included re-intubation, emergent exploratory laparotomy, and drainage of irrigation fluid. Difficulty with ventilation should alert the anesthesiologist to consider abdominal compartment syndrome high in the list of differential diagnoses during any endoscopic bladder or bowel case.

  17. Activities of microorganisms and enzymes in water-restricted environments: biological activities in aqueous compartments at micron scale

    NASA Astrophysics Data System (ADS)

    Hoppert, Michael; Mlejnek, Klaus; Seiffert, Beatrix; Mayer, Frank

    1997-07-01

    In water-in-oil microemulsions, microdroplets of water, surrounded by a layer of surfactant molecules (reversed micelles), are dispersed in an organic solvent. Various microorganisms (unicellular algae and cyanobacteria) and isolated enzymes were dispersed in microemulsions without loss of biological activity. Each biological system needed a defined quantity of water in the microemulsion for maximum activity. Under optimum conditions, microbial enzymes for various sources (hydrogenases, dehydrogenases) exhibited, besides ten-fold increase in specific activity, a temperature optimum up to 16 degree(s)C higher as compared to aqueous solutions. These experimental findings, together with theoretical considerations, imply that water structure inside reversed micelles is very different from free water, but similar to water in narrow compartments with polar or ionic surfaces. These compartments may represent a model system for environments, where (liquid) water is not available in bulk amounts, but embedded in an anhydrous matrix.

  18. Development of a patient-specific two-compartment anthropomorphic breast phantom

    NASA Astrophysics Data System (ADS)

    Prionas, Nicolas D.; Burkett, George W.; McKenney, Sarah E.; Chen, Lin; Stern, Robin L.; Boone, John M.

    2012-07-01

    The purpose of this paper is to develop a technique for the construction of a two-compartment anthropomorphic breast phantom specific to an individual patient's pendant breast anatomy. Three-dimensional breast images were acquired on a prototype dedicated breast computed tomography (bCT) scanner as part of an ongoing IRB-approved clinical trial of bCT. The images from the breast of a patient were segmented into adipose and glandular tissue regions and divided into 1.59 mm thick breast sections to correspond to the thickness of polyethylene stock. A computer-controlled water-jet cutting machine was used to cut the outer breast edge and the internal regions corresponding to glandular tissue from the polyethylene. The stack of polyethylene breast segments was encased in a thermoplastic ‘skin’ and filled with water. Water-filled spaces modeled glandular tissue structures and the surrounding polyethylene modeled the adipose tissue compartment. Utility of the phantom was demonstrated by inserting 200 µm microcalcifications as well as by measuring point dose deposition during bCT scanning. Affine registration of the original patient images with bCT images of the phantom showed similar tissue distribution. Linear profiles through the registered images demonstrated a mean coefficient of determination (r2) between grayscale profiles of 0.881. The exponent of the power law describing the anatomical noise power spectrum was identical in the coronal images of the patient's breast and the phantom. Microcalcifications were visualized in the phantom at bCT scanning. The real-time air kerma rate was measured during bCT scanning and fluctuated with breast anatomy. On average, point dose deposition was 7.1% greater than the mean glandular dose. A technique to generate a two-compartment anthropomorphic breast phantom from bCT images has been demonstrated. The phantom is the first, to our knowledge, to accurately model the uncompressed pendant breast and the glandular tissue

  19. Development of a patient-specific two-compartment anthropomorphic breast phantom.

    PubMed

    Prionas, Nicolas D; Burkett, George W; McKenney, Sarah E; Chen, Lin; Stern, Robin L; Boone, John M

    2012-07-07

    The purpose of this paper is to develop a technique for the construction of a two-compartment anthropomorphic breast phantom specific to an individual patient's pendant breast anatomy. Three-dimensional breast images were acquired on a prototype dedicated breast computed tomography (bCT) scanner as part of an ongoing IRB-approved clinical trial of bCT. The images from the breast of a patient were segmented into adipose and glandular tissue regions and divided into 1.59 mm thick breast sections to correspond to the thickness of polyethylene stock. A computer-controlled water-jet cutting machine was used to cut the outer breast edge and the internal regions corresponding to glandular tissue from the polyethylene. The stack of polyethylene breast segments was encased in a thermoplastic 'skin' and filled with water. Water-filled spaces modeled glandular tissue structures and the surrounding polyethylene modeled the adipose tissue compartment. Utility of the phantom was demonstrated by inserting 200 µm microcalcifications as well as by measuring point dose deposition during bCT scanning. Affine registration of the original patient images with bCT images of the phantom showed similar tissue distribution. Linear profiles through the registered images demonstrated a mean coefficient of determination (r(2)) between grayscale profiles of 0.881. The exponent of the power law describing the anatomical noise power spectrum was identical in the coronal images of the patient's breast and the phantom. Microcalcifications were visualized in the phantom at bCT scanning. The real-time air kerma rate was measured during bCT scanning and fluctuated with breast anatomy. On average, point dose deposition was 7.1% greater than the mean glandular dose. A technique to generate a two-compartment anthropomorphic breast phantom from bCT images has been demonstrated. The phantom is the first, to our knowledge, to accurately model the uncompressed pendant breast and the glandular tissue

  20. MeLiSSA third compartment: a kinetic and stoichiometric study for Nitrosomonas europaea and Nitrobacter winogradskyi axenic cultures

    NASA Astrophysics Data System (ADS)

    Creuly, Catherine; Poughon, Laurent; Dussap, Claude-Gilles; Farges, Berangere

    2012-07-01

    As a part of a natural biological N-cycle, nitrification is one of the steps included in the conception of artificial ecosystems designed for extraterrestrial life support systems (LSS). In MELiSSA loop, which is based on carbon and nitrogen recycling, the non-edible part of the higher plants and the waste produced by the crew are collected in the liquefying compartment that degrades the chemically complex wastes into simpler building blocks (organic acids and CO2). The organic acids are eliminated in the second photoheterotrophic compartment letting an organic free medium mostly containing minerals and N-NH+4 nitrogen. The third compartment is in charge to re-oxidize N-NH+4 in order to make nitrogen usable by the following compartments. In MELiSSA, the constraint is to perform axenic cultures in order to fully control the genetic status of the culture and a thorough modelling for developing a control strategy of the compartment and of the loop, knowing that the reliability of the production of oxidized forms of nitrogen NO3- directly impacts the behaviour of the following compartments. Nitrification in aerobic environments is carried out by two groups of bacteria in co-cultures in a two-step process. The ammonia-oxidizing bacteria (Nitrosomonas europaea) realize the oxidation of ammonia to nitrite and the nitrite-oxidizing bacteria (Nitrobacter winogradskyi) the oxidation of nitrite to nitrate. In both cases, the bacteria achieve the oxidations to obtain an energy and reductant source for their growth and maintenance. Both groups use CO2 predominantly as their carbon source. They are typically found together in ecosystems and, consequently, nitrite accumulation is rare. This study concerns kinetic and mass balances studies of axenic cultures of Ns. europaea and Nb. winogradskyi in autotrophic conditions. The daily follow-up of these cultures is done using a new protocol involving flow cytometry and ionic chromatography. Nitrogen substrates and products are

  1. Lateral compartment translation predicts the grade of pivot shift: a cadaveric and clinical analysis.

    PubMed

    Bedi, Asheesh; Musahl, Volker; Lane, Clayton; Citak, Musa; Warren, Russell F; Pearle, Andrew D

    2010-09-01

    Anterior translation of the lateral compartment was hypothesized to correlate with the clinical grade of a pivot shift maneuver. Using a computer-assisted navigation system, this hypothesis was tested by recording the maximum anterior tibial translation in the medial and lateral compartment as well as the arc of rotation during the pivot shift maneuver. One hundred and fifty-four pivot shift examinations were performed on cadavers with various degrees of instability, and 24 pivot shift exams were performed on patients under anesthesia before and after ACL reconstruction. In all positive pivot shift exams, anterior tibial translations were found to be higher on in the lateral compartment compared to the medial compartment. In addition, an excellent correlation was found between the amount of lateral compartment translation and the clinical grade of the pivot shift; medial compartment translations and amount of knee rotation could not distinguish between clinical grades. Finally, a threshold of 6-7 mm of anterior tibial translation in the lateral compartment was necessary to produce a positive pivot shift. Taken together, these data suggest that monitoring lateral compartment translations during a pivot shift exam may be a convenient means to evaluate the outcomes of ACL surgery and that requisite increases in anterior translation of the lateral compartment are necessary for each progressive clinical grade of the pivot shift examination.

  2. Anomalous supratendinous course of the fifth extensor compartment artery: a case report.

    PubMed

    Tracy, C Alan

    2007-12-01

    Vascularized bone grafts have been successfully used in the treatment of carpal bone nonunion and avascular necrosis. The 4 + 5 extensor compartmental vascularized bone graft based on the fourth extensor compartment artery with retrograde blood flow through the fifth extensor compartment artery is the pedicle of choice for vascularized bone grafting of the lunate. This case report describes an anomalous supratendinous course of the fifth extensor compartment artery. The recognition of this anatomic variant is important for the safe dissection of the fifth extensor compartment artery.

  3. EXERTIONAL COMPARTMENT SYNDROME: REVIEW OF THE LITERATURE AND PROPOSED REHABILITATION GUIDELINES FOLLOWING SURGICAL RELEASE

    PubMed Central

    2011-01-01

    Background: There is little published information regarding postoperative management of patients with Chronic Exertional Compartment Syndrome (CECS). Reports of recurrence of symptoms following surgical decompression exist, and are not uncommon depending on the specific technique used. Recurrence suggests that more time and effort may need to be spent on implementing strategic post-operative rehabilitation management in order to avoid repeat surgical intervention or prolonged symptoms. Objective: To summarize relevant literature regarding CECS and propose scientifically-based guidelines for rehab following compartment release with the rationale based on tissue healing, muscle loading, and scar tissue formation and consideration of all tissues contained in the involved compartment. Literature review: A literature search was performed in PubMed, SPORTDiscus, CINAHL, PEDRO, and Google Scholar using the phrase: “chronic exertional compartment syndrome.” Results: No specific rehabilitation guidelines following surgical compartment release for lower extremity CECS were found in the literature search performed for this clinical commentary. Discussion: The development of the proposed post-operative guidelines may allow for improved long-term outcomes following anterior compartment release. Summary: Adequate description of long-term follow-up of outcomes following compartment release for CECS is lacking in current literature. The proposed guidelines for rehab following compartment release include consideration of tissue healing, muscle loading, scar tissue formation, and consideration of soft tissues contained in the involved compartment. Utilization of the proposed guidelines may allow for future research to be performed in order to assess outcomes following surgical intervention for CECS. PMID:21713230

  4. Compartment Syndrome of the Hand: A Rare Sequela of Transradial Cardiac Catheterization

    PubMed Central

    Jue, Jennifer; Karam, Joseph A.; Mejia, Alfonso

    2017-01-01

    A 64-year-old man who underwent percutaneous coronary intervention via right radial artery access reported right-hand pain and swelling 2 hours after the procedure. He had developed compartment syndrome of the hand, specifically with muscular compromise of the thenar compartment but with no involvement of the forearm. He underwent emergency right-hand compartment release and carpal tunnel release, followed by an uneventful postoperative course. In addition to our patient's case, we discuss compartment syndrome of the hand and related issues. PMID:28265219

  5. Acute thigh compartment syndrome post femoral vein catheterization: a case report.

    PubMed

    Asplund, Mark W

    2008-08-01

    This case report presents a previously unreported etiology of acute thigh compartment syndrome following ipsilateral femoral vein catheterization, including clinical results and a brief review of the literature.

  6. A swollen hand with blisters: a case of compartment syndrome in a child.

    PubMed

    Rios-Alba, Tonatiuh; Ahn, James

    2015-06-01

    The accurate identification of compartment syndrome in the emergency department is essential to timely treatment and prevention of long-term sequela. Recognizing compartment syndrome is not straightforward, especially in the pediatric population. In addition to communication barriers that exist with children, the classic signs of pain, pallor, paresthesia, paralysis, and pulselessness are not always present, making its diagnosis a challenge. We report a case of a child with compartment syndrome to the left hand due to compression from an ACE wrap. The existing literature on compartment syndrome in children is reviewed.

  7. Regulation of Stem Cell Proliferation and Cell Fate Specification by Wingless/Wnt Signaling Gradients Enriched at Adult Intestinal Compartment Boundaries

    PubMed Central

    Tian, Ai; Benchabane, Hassina; Wang, Zhenghan; Ahmed, Yashi

    2016-01-01

    Intestinal stem cell (ISC) self-renewal and proliferation are directed by Wnt/β-catenin signaling in mammals, whereas aberrant Wnt pathway activation in ISCs triggers the development of human colorectal carcinoma. Herein, we have utilized the Drosophila midgut, a powerful model for ISC regulation, to elucidate the mechanisms by which Wingless (Wg)/Wnt regulates intestinal homeostasis and development. We provide evidence that the Wg signaling pathway, activation of which peaks at each of the major compartment boundaries of the adult intestine, has essential functions. Wg pathway activation in the intestinal epithelium is required not only to specify cell fate near compartment boundaries during development, but also to control ISC proliferation within compartments during homeostasis. Further, in contrast with the previous focus on Wg pathway activation within ISCs, we demonstrate that the primary mechanism by which Wg signaling regulates ISC proliferation during homeostasis is non-autonomous. Activation of the Wg pathway in absorptive enterocytes is required to suppress JAK-STAT signaling in neighboring ISCs, and thereby their proliferation. We conclude that Wg signaling gradients have essential roles during homeostasis and development of the adult intestine, non-autonomously controlling stem cell proliferation inside compartments, and autonomously specifying cell fate near compartment boundaries. PMID:26845150

  8. Dendritic spines as individual neuronal compartments for synaptic Ca2+ responses.

    PubMed

    Müller, W; Connor, J A

    1991-11-07

    The possibility that postsynaptic spines on neuronal dendrites are discrete biochemical compartments for Ca(2+)-activated processes involved in synaptic plasticity is a widely proposed concept that has eluded experimental demonstration. Using microfluorometry on CA3 neurons in hippocampal slices, we show here that with weak presynaptic stimulation of associative/commissural fibres, Ca2+ accumulates in single postsynaptic spines but not in the parent dendrite. Stronger stimulation also promotes changes in dendrites. The NMDA-receptor antagonist AP-5 blocks changes in Ca2+ in spines. Sustained steep Ca2+ gradients between single spines and the parent dendrite, often lasting several minutes, develop with repeated stimulation. The observed compartmentalization allows for the specificity, cooperativity and associativity displayed by memory models such as long-term potentiation.

  9. Promotion of testa rupture during garden cress germination involves seed compartment-specific expression and activity of pectin methylesterases.

    PubMed

    Scheler, Claudia; Weitbrecht, Karin; Pearce, Simon P; Hampstead, Anthony; Büttner-Mainik, Annette; Lee, Kieran J D; Voegele, Antje; Oracz, Krystyna; Dekkers, Bas J W; Wang, Xiaofeng; Wood, Andrew T A; Bentsink, Leónie; King, John R; Knox, J Paul; Holdsworth, Michael J; Müller, Kerstin; Leubner-Metzger, Gerhard

    2015-01-01

    Pectin methylesterase (PME) controls the methylesterification status of pectins and thereby determines the biophysical properties of plant cell walls, which are important for tissue growth and weakening processes. We demonstrate here that tissue-specific and spatiotemporal alterations in cell wall pectin methylesterification occur during the germination of garden cress (Lepidium sativum). These cell wall changes are associated with characteristic expression patterns of PME genes and resultant enzyme activities in the key seed compartments CAP (micropylar endosperm) and RAD (radicle plus lower hypocotyl). Transcriptome and quantitative real-time reverse transcription-polymerase chain reaction analysis as well as PME enzyme activity measurements of separated seed compartments, including CAP and RAD, revealed distinct phases during germination. These were associated with hormonal and compartment-specific regulation of PME group 1, PME group 2, and PME inhibitor transcript expression and total PME activity. The regulatory patterns indicated a role for PME activity in testa rupture (TR). Consistent with a role for cell wall pectin methylesterification in TR, treatment of seeds with PME resulted in enhanced testa permeability and promoted TR. Mathematical modeling of transcript expression changes in germinating garden cress and Arabidopsis (Arabidopsis thaliana) seeds suggested that group 2 PMEs make a major contribution to the overall PME activity rather than acting as PME inhibitors. It is concluded that regulated changes in the degree of pectin methylesterification through CAP- and RAD-specific PME and PME inhibitor expression play a crucial role during Brassicaceae seed germination.

  10. Facile synthesis of dumbbell-shaped multi-compartment nanoparticles

    NASA Astrophysics Data System (ADS)

    Doermbach, Karla; Pich, Andrij

    2015-05-01

    In this article we report on the controlled synthesis of asymmetric lemon-shaped and dumbbell-shaped multi-compartment nanoparticles (MCPs) with a reactive surface and interesting morphology. In our approach we utilize partial coating of hematite ellipsoids with a hydrophobic polymer layer followed by selective silica deposition on the non-coated surface. Ellipsoidal hematite particles provide a non-centric asymmetry, which is strongly enhanced during the seeded emulsion polymerization. The asymmetric growth of polymers on the hematite particle surface is driven by phase separation phenomena, which lead to a reduction of the interfacial tension. We found the tips of the hematite ellipsoids to be uncovered after polymerization. A selective deposition of silica onto the free tips leads to dumbbell-shaped particles with hydrophilic and hydrophobic parts.In this article we report on the controlled synthesis of asymmetric lemon-shaped and dumbbell-shaped multi-compartment nanoparticles (MCPs) with a reactive surface and interesting morphology. In our approach we utilize partial coating of hematite ellipsoids with a hydrophobic polymer layer followed by selective silica deposition on the non-coated surface. Ellipsoidal hematite particles provide a non-centric asymmetry, which is strongly enhanced during the seeded emulsion polymerization. The asymmetric growth of polymers on the hematite particle surface is driven by phase separation phenomena, which lead to a reduction of the interfacial tension. We found the tips of the hematite ellipsoids to be uncovered after polymerization. A selective deposition of silica onto the free tips leads to dumbbell-shaped particles with hydrophilic and hydrophobic parts. Electronic supplementary information (ESI) available: TEM images of silica coating without a polymer layer, experiments for removal of the polymer by solvent extraction, TEM images of spherical α-Fe2O3 nanoparticles with an asymmetric PSGD coating, and additional FESEM

  11. Iron repletion relocalizes hephaestin to a proximal basolateral compartment in polarized MDCK and Caco2 cells

    SciTech Connect

    Lee, Seung-Min; Attieh, Zouhair K.; Son, Hee Sook; Chen, Huijun; Bacouri-Haidar, Mhenia; Vulpe, Chris D.

    2012-05-11

    Highlights: Black-Right-Pointing-Pointer Hephaestin localizes in the perinuclear space in non-polarized cells. Black-Right-Pointing-Pointer Hephaestin localizes in the perinuclear space in iron deficient and polarized cells. Black-Right-Pointing-Pointer Hephaestin with apical iron moves near to basolateral membrane of polarized cells. Black-Right-Pointing-Pointer Peri-basolateral location of hephaestin is accessible to the extracellular space. Black-Right-Pointing-Pointer Hephaestin is involved in iron mobilization from the intestine to circulation. -- Abstract: While intestinal cellular iron entry in vertebrates employs multiple routes including heme and non-heme routes, iron egress from these cells is exclusively channeled through the only known transporter, ferroportin. Reduced intestinal iron export in sex-linked anemia mice implicates hephaestin, a ferroxidase, in this process. Polarized cells are exposed to two distinct environments. Enterocytes contact the gut lumen via the apical surface of the cell, and through the basolateral surface, to the body. Previous studies indicate both local and systemic control of iron uptake. We hypothesized that differences in iron availability at the apical and/or basolateral surface may modulate iron uptake via cellular localization of hephaestin. We therefore characterized the localization of hephaestin in two models of polarized epithelial cell lines, MDCK and Caco2, with varying iron availability at the apical and basolateral surfaces. Our results indicate that hephaestin is expressed in a supra-nuclear compartment in non-polarized cells regardless of the iron status of the cells and in iron deficient and polarized cells. In polarized cells, we found that both apical (as FeSO{sub 4}) and basolateral iron (as the ratio of apo-transferrin to holo-transferrin) affect mobilization of hephaestin from the supra-nuclear compartment. We find that the presence of apical iron is essential for relocalization of hephaestin to a

  12. Deep water masses and sediments are main compartments for polychlorinated biphenyls in the Arctic Ocean.

    PubMed

    Sobek, Anna; Gustafsson, Örjan

    2014-06-17

    There is a wealth of studies of polychlorinated biphenyls (PCB) in surface water and biota of the Arctic Ocean. Still, there are no observation-based assessments of PCB distribution and inventories in and between the major Arctic Ocean compartments. Here, the first water column distribution of PCBs in the central Arctic Ocean basins (Nansen, Amundsen, and Makarov) is presented, demonstrating nutrient-like vertical profiles with 5-10 times higher concentrations in the intermediate and deep water masses than in surface waters. The consistent vertical profiles in all three Arctic Ocean basins likely reflect buildup of PCBs transported from the shelf seas and from dissolution and/or mineralization of settling particles. Combined with measurement data on PCBs in other Arctic Ocean compartments collected over the past decade, the total Arctic Ocean inventory of ∑7PCB was estimated to 182 ± 40 t (±1 standard error of the mean), with sediments (144 ± 40 t), intermediate (5 ± 1 t) and deep water masses (30 ± 2 t) storing 98% of the PCBs in the Arctic Ocean. Further, we used hydrographic and carbon cycle parametrizations to assess the main pathways of PCBs into and out of the Arctic Ocean during the 20th century. River discharge appeared to be the major pathway for PCBs into the Arctic Ocean with 115 ± 11 t, followed by ocean currents (52 ± 17 t) and net atmospheric deposition (30 ± 28 t). Ocean currents provided the only important pathway out of the Arctic Ocean, with an estimated cumulative flux of 22 ± 10 t. The observation-based inventory of ∑7PCB of 182 ± 40 t is consistent with the contemporary inventory based on cumulative fluxes for ∑7PCB of 173 ± 36 t. Information on the concentration and distribution of PCBs in the deeper compartments of the Arctic Ocean improves our understanding of the large-scale fate of POPs in the Arctic and may also provide a means to test and improve models used to assess the fate of organic pollutants in the Arctic.

  13. Essential role of the chaperonin folding compartment in vivo

    PubMed Central

    Tang, Yun-Chi; Chang, Hung-Chun; Chakraborty, Kausik; Hartl, F Ulrich; Hayer-Hartl, Manajit

    2008-01-01

    The GroEL/GroES chaperonin system of Escherichia coli forms a nano-cage allowing single protein molecules to fold in isolation. However, as the chaperonin can also mediate folding independently of substrate encapsulation, it remained unclear whether the folding cage is essential in vivo. To address this question, we replaced wild-type GroEL with mutants of GroEL having either a reduced cage volume or altered charge properties of the cage wall. A stepwise reduction in cage size resulted in a gradual loss of cell viability, although the mutants bound non-native protein efficiently. Strikingly, a mild reduction in cage size increased the yield and the apparent rate of green fluorescent protein folding, consistent with the view that an effect of steric confinement can accelerate folding. As shown in vitro, the observed acceleration of folding was dependent on protein encapsulation by GroES but independent of GroES cycling regulated by the GroEL ATPase. Altering the net-negative charge of the GroEL cage wall also strongly affected chaperonin function. Based on these findings, the GroEL/GroES compartment is essential for protein folding in vivo. PMID:18418386

  14. Shigella subverts the host recycling compartment to rupture its vacuole.

    PubMed

    Mellouk, Nora; Weiner, Allon; Aulner, Nathalie; Schmitt, Christine; Elbaum, Michael; Shorte, Spencer L; Danckaert, Anne; Enninga, Jost

    2014-10-08

    Shigella enters epithlial cells via internalization into a vacuole. Subsequent vacuolar membrane rupture allows bacterial escape into the cytosol for replication and cell-to-cell spread. Bacterial effectors such as IpgD, a PI(4,5)P2 phosphatase that generates PI(5)P and alters host actin, facilitate this internalization. Here, we identify host proteins involved in Shigella uptake and vacuolar membrane rupture by high-content siRNA screening and subsequently focus on Rab11, a constituent of the recycling compartment. Rab11-positive vesicles are recruited to the invasion site before vacuolar rupture, and Rab11 knockdown dramatically decreases vacuolar membrane rupture. Additionally, Rab11 recruitment is absent and vacuolar rupture is delayed in the ipgD mutant that does not dephosphorylate PI(4,5)P₂ into PI(5)P. Ultrastructural analyses of Rab11-positive vesicles further reveal that ipgD mutant-containing vacuoles become confined in actin structures that likely contribute to delayed vacular rupture. These findings provide insight into the underlying molecular mechanism of vacuole progression and rupture during Shigella invasion.

  15. Status of the International Space Station Waste and Hygiene Compartment

    NASA Technical Reports Server (NTRS)

    Walker, Stephanie; Zahner, Christopher

    2010-01-01

    The Waste and Hygiene Compartment (WHC) serves as the primary system for removal and containment of metabolic waste and hygiene activities on board the United States segment of the International Space Station (ISS). The WHC was launched on ULF 2 and is currently in the U.S. Laboratory and is integrated into the Water Recovery System (WRS) where pretreated urine is processed by the Urine Processor Assembly (UPA). The waste collection part of the WHC system is derived from the Service Module system and was provided by RSC-Energia along with additional hardware to allow for urine delivery to the UPA. The System has been integrated in an ISS standard equipment rack structure for use on the U.S. segment of the ISS. The system has experienced several events of interest during the deployment, checkout, and operation of the system during its first year of use and these will be covered in this paper. Design and on-orbit performance will also be discussed.

  16. International Space Station USOS Waste and Hygiene Compartment Development

    NASA Technical Reports Server (NTRS)

    Link, Dwight E., Jr.; Broyan, James Lee, Jr.; Gelmis, Karen; Philistine, Cynthia; Balistreri, Steven

    2007-01-01

    The International Space Station (ISS) currently provides human waste collection and hygiene facilities in the Russian Segment Service Module (SM) which supports a three person crew. Additional hardware is planned for the United States Operational Segment (USOS) to support expansion of the crew to six person capability. The additional hardware will be integrated in an ISS standard equipment rack structure that was planned to be installed in the Node 3 element; however, the ISS Program Office recently directed implementation of the rack, or Waste and Hygiene Compartment (WHC), into the U.S. Laboratory element to provide early operational capability. In this configuration, preserved urine from the WHC waste collection system can be processed by the Urine Processor Assembly (UPA) in either the U.S. Lab or Node 3 to recover water for crew consumption or oxygen production. The human waste collection hardware is derived from the Service Module system and is provided by RSC-Energia. This paper describes the concepts, design, and integration of the WHC waste collection hardware into the USOS including integration with U.S. Lab and Node 3 systems.

  17. 46 CFR 171.017 - One and two compartment standards of flooding.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false One and two compartment standards of flooding. 171.017 Section 171.017 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY SPECIAL RULES PERTAINING TO VESSELS CARRYING PASSENGERS General § 171.017 One and two compartment standards of flooding. (a) One...

  18. 14 CFR 121.576 - Retention of items of mass in passenger and crew compartments.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Retention of items of mass in passenger and crew compartments. 121.576 Section 121.576 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... § 121.576 Retention of items of mass in passenger and crew compartments. The certificate holder...

  19. 14 CFR 121.576 - Retention of items of mass in passenger and crew compartments.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Retention of items of mass in passenger and crew compartments. 121.576 Section 121.576 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... § 121.576 Retention of items of mass in passenger and crew compartments. The certificate holder...

  20. 14 CFR 121.576 - Retention of items of mass in passenger and crew compartments.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Retention of items of mass in passenger and crew compartments. 121.576 Section 121.576 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... § 121.576 Retention of items of mass in passenger and crew compartments. The certificate holder...

  1. 14 CFR 121.576 - Retention of items of mass in passenger and crew compartments.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Retention of items of mass in passenger and crew compartments. 121.576 Section 121.576 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... § 121.576 Retention of items of mass in passenger and crew compartments. The certificate holder...

  2. 19 CFR 18.4 - Sealing conveyances and compartments; labeling packages; warning cards.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... transported is waived under paragraph (a) or (b) of this section. When the packages are shipped in a railroad... or compartments in which carload lots of bonded merchandise are transported shall be sealed with... conveyances or compartments in which bonded merchandise is transported in other cases when in his opinion...

  3. 46 CFR 32.70-20 - Pump-engine compartment-TB/ALL.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Pump-engine compartment-TB/ALL. 32.70-20 Section 32.70..., 1936 § 32.70-20 Pump-engine compartment—TB/ALL. No cofferdam will be required between a cargo tank and a compartment containing pumping engines and their auxiliaries which are used exclusively...

  4. 14 CFR 121.548 - Aviation safety inspector's credentials: Admission to pilot's compartment.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Aviation safety inspector's credentials: Admission to pilot's compartment. 121.548 Section 121.548 Aeronautics and Space FEDERAL AVIATION... Operations § 121.548 Aviation safety inspector's credentials: Admission to pilot's compartment. Whenever,...

  5. 14 CFR 121.548 - Aviation safety inspector's credentials: Admission to pilot's compartment.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Aviation safety inspector's credentials: Admission to pilot's compartment. 121.548 Section 121.548 Aeronautics and Space FEDERAL AVIATION... Operations § 121.548 Aviation safety inspector's credentials: Admission to pilot's compartment. Whenever,...

  6. 14 CFR 121.548 - Aviation safety inspector's credentials: Admission to pilot's compartment.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Aviation safety inspector's credentials: Admission to pilot's compartment. 121.548 Section 121.548 Aeronautics and Space FEDERAL AVIATION... Operations § 121.548 Aviation safety inspector's credentials: Admission to pilot's compartment. Whenever,...

  7. 14 CFR 121.548 - Aviation safety inspector's credentials: Admission to pilot's compartment.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Aviation safety inspector's credentials: Admission to pilot's compartment. 121.548 Section 121.548 Aeronautics and Space FEDERAL AVIATION... Operations § 121.548 Aviation safety inspector's credentials: Admission to pilot's compartment. Whenever,...

  8. 14 CFR 121.548 - Aviation safety inspector's credentials: Admission to pilot's compartment.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Aviation safety inspector's credentials: Admission to pilot's compartment. 121.548 Section 121.548 Aeronautics and Space FEDERAL AVIATION... Operations § 121.548 Aviation safety inspector's credentials: Admission to pilot's compartment. Whenever,...

  9. 14 CFR 25.858 - Cargo or baggage compartment smoke or fire detection systems.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... detection systems. 25.858 Section 25.858 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT... Construction Fire Protection § 25.858 Cargo or baggage compartment smoke or fire detection systems. If certification with cargo or baggage compartment smoke or fire detection provisions is requested, the...

  10. 14 CFR 25.858 - Cargo or baggage compartment smoke or fire detection systems.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... detection systems. 25.858 Section 25.858 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT... Construction Fire Protection § 25.858 Cargo or baggage compartment smoke or fire detection systems. If certification with cargo or baggage compartment smoke or fire detection provisions is requested, the...

  11. Posterior thigh compartment syndrome as a result of a basketball injury.

    PubMed

    Mallo, Gregory C; Stanat, Scott J C; Al-Humadi, Mohaned; Divaris, Nicholas

    2009-12-01

    Acute compartment syndrome of the thigh is a serious although rare occurrence that was sparsely documented in the orthopedic literature until Schwartz et al reported on a series of 21 cases. Although classically associated with high-energy femur fracture, thigh contusion, or the use of military anti-shock trousers, compartment syndrome of the thigh has recently been diagnosed in seemingly low-energy injuries. A complete hamstring avulsion from its ischial origin during routine ambulation and rupture of the quadriceps tendon after a low-energy fall have been shown to result in compartment syndrome. In light of the potential medicolegal ramifications surrounding the diagnosis of compartment syndrome, emergency room consultations to rule out compartment syndrome are on the rise. Specifically, the time to fasciotomy was found to be linearly related to indemnity payment, and a fasciotomy performed within 8 hours was uniformly associated with a successful defense. This article describes a case of a 29-year-old healthy man who developed posterior thigh compartment syndrome as a result of an intrasubstance tear of the biceps femoris muscle sustained while attempting a lay-up during a recreational basketball game. His posterior thigh compartment pressure measured 70 mm Hg and he required emergent posterior thigh compartment fasciotomy.

  12. Compartments in a marine food web associated with phylogeny, body mass, and habitat structure.

    PubMed

    Rezende, Enrico L; Albert, Eva M; Fortuna, Miguel A; Bascompte, Jordi

    2009-08-01

    A long-standing question in community ecology is whether food webs are organized in compartments, where species within the same compartment interact frequently among themselves, but show fewer interactions with species from other compartments. Finding evidence for this community organization is important since compartmentalization may strongly affect food web robustness to perturbation. However, few studies have found unequivocal evidence of compartments, and none has quantified the suite of mechanisms generating such a structure. Here, we combine computational tools from the physics of complex networks with phylogenetic statistical methods to show that a large marine food web is organized in compartments, and that body size, phylogeny, and spatial structure are jointly associated with such a compartmentalized structure. Sharks account for the majority of predatory interactions within their compartments. Phylogenetically closely related shark species tend to occupy different compartments and have divergent trophic levels, suggesting that competition may play an important role structuring some of these compartments. Current overfishing of sharks has the potential to change the structural properties, which might eventually affect the stability of the food web.

  13. 19 CFR 24.13 - Car, compartment, and package seals; kind, procurement.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 1 2012-04-01 2012-04-01 false Car, compartment, and package seals; kind... SECURITY; DEPARTMENT OF THE TREASURY CUSTOMS FINANCIAL AND ACCOUNTING PROCEDURE § 24.13 Car, compartment.... ports as provided in §§ 123.24 and 123.51 of this chapter shall be stamped for use on railroad cars,...

  14. 19 CFR 24.13 - Car, compartment, and package seals; kind, procurement.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 1 2014-04-01 2014-04-01 false Car, compartment, and package seals; kind... SECURITY; DEPARTMENT OF THE TREASURY CUSTOMS FINANCIAL AND ACCOUNTING PROCEDURE § 24.13 Car, compartment.... ports as provided in §§ 123.24 and 123.51 of this chapter shall be stamped for use on railroad cars,...

  15. 19 CFR 24.13 - Car, compartment, and package seals; kind, procurement.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 1 2011-04-01 2011-04-01 false Car, compartment, and package seals; kind... SECURITY; DEPARTMENT OF THE TREASURY CUSTOMS FINANCIAL AND ACCOUNTING PROCEDURE § 24.13 Car, compartment.... ports as provided in §§ 123.24 and 123.51 of this chapter shall be stamped for use on railroad cars,...

  16. 19 CFR 24.13 - Car, compartment, and package seals; kind, procurement.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 1 2013-04-01 2013-04-01 false Car, compartment, and package seals; kind... SECURITY; DEPARTMENT OF THE TREASURY CUSTOMS FINANCIAL AND ACCOUNTING PROCEDURE § 24.13 Car, compartment.... ports as provided in §§ 123.24 and 123.51 of this chapter shall be stamped for use on railroad cars,...

  17. Anatomical compartments of the parasellar region: adipose tissue bodies represent intracranial continuations of extracranial spaces

    PubMed Central

    WENINGER, WOLFGANG J.; STREICHER, JOHANNES; MÜLLER, GERD B.

    1997-01-01

    The cavernous sinus is traditionally described as a single anatomical compartment that contains cranial nerves, blood vessels, and connective tissue. A detailed analysis of 45 infant and 4 fetal parasellar regions shows that this view must be modified. The spatial arrangement, the topographic relations, and the expansion of the adipose and connective tissue spaces were analysed and reconstructed 3-dimensionally on a computer. It is shown that 3 different anatomical compartments, which are strictly demarcated by connective tissue, compose the parasellar region of infants. Two represent intracranial continuations of extracranial tissue spaces. The 3rd compartment corresponds to the so-called ‘cavernous sinus’ of the adult. Each of the 3 compartments contains characteristic adipose tissue bodies. Because the cavernous sinus represents only one compartment of the area, we propose to use the term ‘parasellar region’ to designate the entire anatomical region on either side of the sella turcica. PMID:9306202

  18. Non-traumatic compartment syndrome secondary to deep vein thrombosis and anticoagulation

    PubMed Central

    Newman, Peter Alexander; Deo, Sunny

    2014-01-01

    We describe an unusual case of non-traumatic compartment syndrome in three compartments of the left lower limb in a 57-year-old male inpatient. He had recently been started on anticoagulation therapy for multiple pulmonary emboli and deep vein thrombosis of the left posterior tibial and peroneal veins. Three of the four osteofascial compartments had pressures above 70 mm Hg, hence four compartment fasciotomies were performed. Postoperatively, intravenous heparin therapy was started resulting in a significant blood loss, but he had no neurovascular deficit. At reoperation, for primary wound closure, his tissues looked healthy. Non-traumatic causes of acute compartment syndrome, including deep venous thrombosis and anticoagulation, are considered. PMID:24443334

  19. Simulation of batch-operated experimental wetland mesocosms in AQUASIM biofilm reactor compartment.

    PubMed

    Mburu, Njenga; Rousseau, Diederik P L; Stein, Otto R; Lens, Piet N L

    2014-02-15

    In this study, a mathematical biofilm reactor model based on the structure of the Constructed Wetland Model No.1 (CWM1) coupled to AQUASIM's biofilm reactor compartment has been used to reproduce the sequence of transformation and degradation of organic matter, nitrogen and sulphur observed in a set of constructed wetland mesocosms and to elucidate the development over time of microbial species as well as the biofilm thickness of a multispecies bacterial biofilm in a subsurface constructed wetland. Experimental data from 16 wetland mesocosms operated under greenhouse conditions, planted with three different plant species (Typha latifolia, Carex rostrata, Schoenoplectus acutus) and an unplanted control were used in the calibration of this mechanistic model. Within the mesocosms, a thin (predominantly anaerobic) biofilm was simulated with an initial thickness of 49 μm (average) and in which no concentration gradients developed. The biofilm density and area, and the distribution of the microbial species within the biofilm were evaluated to be the most sensitive biofilm properties; while the substrate diffusion limitations were not significantly sensitive to influence the bulk volume concentrations. The simulated biofilm density ranging between 105,000 and 153,000 gCOD/m(3) in the mesocosms was observed to vary with temperature, the presence as well as the species of macrophyte. The biofilm modeling was found to be a better tool than the suspended bacterial modeling approach to show the influence of the rhizosphere configuration on the performance of the constructed wetlands.

  20. A hybrid algorithm for coupling partial differential equation and compartment-based dynamics.

    PubMed

    Harrison, Jonathan U; Yates, Christian A

    2016-09-01

    Stochastic simulation methods can be applied successfully to model exact spatio-temporally resolved reaction-diffusion systems. However, in many cases, these methods can quickly become extremely computationally intensive with increasing particle numbers. An alternative description of many of these systems can be derived in the diffusive limit as a deterministic, continuum system of partial differential equations (PDEs). Although the numerical solution of such PDEs is, in general, much more efficient than the full stochastic simulation, the deterministic continuum description is generally not valid when copy numbers are low and stochastic effects dominate. Therefore, to take advantage of the benefits of both of these types of models, each of which may be appropriate in different parts of a spatial domain, we have developed an algorithm that can be used to couple these two types of model together. This hybrid coupling algorithm uses an overlap region between the two modelling regimes. By coupling fluxes at one end of the interface and using a concentration-matching condition at the other end, we ensure that mass is appropriately transferred between PDE- and compartment-based regimes. Our methodology gives notable reductions in simulation time in comparison with using a fully stochastic model, while maintaining the important stochastic features of the system and providing detail in appropriate areas of the domain. We test our hybrid methodology robustly by applying it to several biologically motivated problems including diffusion and morphogen gradient formation. Our analysis shows that the resulting error is small, unbiased and does not grow over time.

  1. Establishment and Maintenance of the Human Naïve CD4+ T-Cell Compartment

    PubMed Central

    Silva, Susana L.; Sousa, Ana E.

    2016-01-01

    The naïve CD4+ T-cell compartment is considered essential to guarantee immune competence throughout life. Its replenishment with naïve cells with broad diverse receptor repertoire, albeit with reduced self-reactivity, is ensured by the thymus. Nevertheless, cumulative data support a major requirement of post-thymic proliferation both for the establishment of the human peripheral naïve compartment during the accelerated somatic growth of childhood, as well as for its lifelong maintenance. Additionally, a dynamic equilibrium is operating at the cell level to fine-tune the T-cell receptor threshold to activation and survival cues, in order to counteract the continuous naïve cell loss by death or conversion into memory/effector cells. The main players in these processes are low-affinity self-peptide/MHC and cytokines, particularly IL-7. Moreover, although naïve CD4+ T-cells are usually seen as a homogeneous population regarding stage of maturation and cell differentiation, increasing evidence points to a variety of phenotypic and functional subsets with distinct homeostatic requirements. The paradigm of cells committed to a distinct lineage in the thymus are the naïve regulatory T-cells, but other functional subpopulations have been identified based on their time span after thymic egress, phenotypic markers, such as CD31, or cytokine production, namely IL-8. Understanding the regulation of these processes is of utmost importance to promote immune reconstitution in several clinical settings, namely transplantation, persistent infections, and aging. In this mini review, we provide an overview of the mechanisms underlying human naïve CD4+ T-cell homeostasis, combining clinical data, experimental studies, and modeling approaches. PMID:27843891

  2. Characterization and comparison of the bacterial microbiota in different gastrointestinal tract compartments in horses.

    PubMed

    Costa, M C; Silva, G; Ramos, R V; Staempfli, H R; Arroyo, L G; Kim, P; Weese, J S

    2015-07-01

    The advance of new sequencing technologies has allowed more comprehensive characterization of complex microbial communities, including the ones inhabiting the intestinal tract. The presence of extreme environmental filters, such as low pH, digestive enzymes and anaerobic conditions along the tract, acts on the selection of unique bacteria in each compartment. The intestinal microbiota has an enormous impact on the maintenance of health. However, data about the bacteria present in the different intestinal compartments of horses are sparse. In this study, high throughput sequencing was used to characterize and compare bacterial profiles from different intestinal compartments of 11 horses scheduled for euthanasia for reasons other than gastrointestinal problems. Marked differences among compartments even at high taxonomic levels were found, with Firmicutes comprising the main bacterial phylum in all compartments. Lactobacillus spp. and Sarcina spp. predominated in the stomach and a marked increase of Streptococcus spp. occurred in the duodenum. Actinobacillus and Clostridium sensu stricto were the most abundant genera in the ileum and '5 genus incertae sedis', a genus from the Subdivision 5 class of the Verrucomicrobia, was the most abundant from the large colon through feces. There was a significant increase in diversity towards the distal gut with similar profiles observed from the cecum through feces at the class level. The bacterial population comprising the equine intestinal tract varies greatly among compartments and fecal samples may be useful as representative of changes occurring in the distal compartments.

  3. Interaction of Salmonella enterica Serotype Typhimurium with Dendritic Cells Is Defined by Targeting to Compartments Lacking Lysosomal Membrane Glycoproteins

    PubMed Central

    García-Del Portillo, Francisco; Jungnitz, Heidrun; Rohde, Manfred; Guzmán, Carlos A.

    2000-01-01

    Dendritic cells (DCs) play a central role in the generation of acquired immunity to infections by pathogenic microorganisms. Salmonella enterica serotype Typhimurium is known to survive and proliferate intracellularly within macrophages and nonphagocytic cells, but no data exist on how this pathogen interacts with DCs. In this report, we show the capacity of serotype Typhimurium to survive within the established mouse DC line CB1. In contrast to the case for the macrophage model, the compartments of DCs containing serotype Typhimurium are devoid of lysosomal membrane glycoproteins and the PhoPQ two-component regulatory system is not essential for pathogen intracellular survival. PMID:10768999

  4. Optic nerve: Separating compartments based on 23Na TQF spectra and TQF-diffusion anisotropy

    NASA Astrophysics Data System (ADS)

    Eliav, Uzi; Xu, Xiang; Jerschow, Alexej; Navon, Gil

    2013-06-01

    We present a triple quantum filtered (TQF) sodium spectroscopy study of an excised bovine optic nerve. By choosing proper experimental parameters, this technique allowed us to independently observe the satellite transitions originating from the various compartments in the tissue. TQF-based diffusion experiments provided further characterization of the compartments in terms of their geometry. As a result, the peak that exhibited the smallest residual quadrupolar splitting, and the largest diffusion anisotropy was assigned to axons. Two other pairs of satellite peaks were assigned to extra-cellular compartments on the basis of either the size of their quadrupolar splitting or the diffusion properties.

  5. Chronic exertional compartment syndrome in a collegiate soccer player: a case report and literature review.

    PubMed

    Farr, Derek; Selesnick, Harlan

    2008-07-01

    Chronic exertional compartment syndrome is a relatively rare condition among running athletes. In those who engage in repetitive activity, it can cause severe, debilitating leg pain. The diagnosis can be made with a thorough workup that includes history and physical examination, radiologic studies (x-rays, magnetic resonance imaging, bone scan), and compartment pressure monitoring. Most patients do not respond well to nonoperative intervention. Fasciotomy provides satisfactory relief of symptoms and helps patients return to their sports. We present the case of a high-level collegiate soccer player with chronic exertional compartment syndrome.

  6. Dual-Compartment Neurofluidic System for Electrophysiological Measurements in Physically Segregated and Functionally Connected Neuronal Cell Culture

    PubMed Central

    Kanagasabapathi, Thirukumaran T.; Ciliberti, Davide; Martinoia, Sergio; Wadman, Wytse J.; Decré, Michel M. J.

    2011-01-01

    We developed a dual-compartment neurofluidic system with inter-connecting microchannels to connect neurons from their respective compartments, placed on a planar microelectrode arrays. The design and development of the compartmented microfluidic device for neuronal cell culture, protocol for sustaining long-term cultures, and neurite growth through microchannels in such a closed compartment device are presented. Using electrophysiological measurements of spontaneous network activity in the compartments and selective pharmacological manipulation of cells in one compartment, the biological origin of network activity and the fluidic isolation between the compartments are demonstrated. The connectivity between neuronal populations via the microchannels and the crossing-over of neurites are verified using transfection experiments and immunofluorescence staining. In addition to the neurite cross-over to the adjacent compartment, functional connectivity between cells in both the compartments is verified using cross-correlation (CC) based techniques. Bidirectional signal propagation between the compartments is demonstrated using functional connectivity maps. CC analysis and connectivity maps demonstrate that the two neuronal populations are not only functionally connected within each compartment but also with each other and a well connected functional network was formed between the compartments despite the physical barrier introduced by the microchannels. PMID:22025913

  7. 14 CFR 25.789 - Retention of items of mass in passenger and crew compartments and galleys.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... crew compartments and galleys. 25.789 Section 25.789 Aeronautics and Space FEDERAL AVIATION... passenger and crew compartments and galleys. (a) Means must be provided to prevent each item of mass (that is part of the airplane type design) in a passenger or crew compartment or galley from becoming...

  8. Compartment-specific activation of PPARγ governs breast cancer tumor growth, via metabolic reprogramming and symbiosis.

    PubMed

    Avena, Paola; Anselmo, Wanda; Whitaker-Menezes, Diana; Wang, Chenguang; Pestell, Richard G; Lamb, Rebecca S; Hulit, James; Casaburi, Ivan; Andò, Sebastiano; Martinez-Outschoorn, Ubaldo E; Lisanti, Michael P; Sotgia, Federica

    2013-05-01

    The role of PPARγ in cancer therapy is controversial, with studies showing either pro-tumorigenic or antineoplastic effects. This debate is very clinically relevant, because PPARγ agonists are used as antidiabetic drugs. Here, we evaluated if the effects of PPARγ on tumorigenesis are determined by the cell type in which PPARγ is activated. Second, we examined if the metabolic changes induced by PPARγ, such as glycolysis and autophagy, play any role in the tumorigenic process. To this end, PPARγ was overexpressed in breast cancer cells or in stromal cells. PPARγ-overexpressing cells were examined with respect to (1) their tumorigenic potential, using xenograft models, and (2) regarding their metabolic features. In xenograft models, we show that when PPARγ is activated in cancer cells, tumor growth is inhibited by 40%. However, when PPARγ is activated in stromal cells, the growth of co-injected breast cancer cells is enhanced by 60%. Thus, the effect(s) of PPARγ on tumorigenesis are dependent on the cell compartment in which PPARγ is activated. Mechanistically, stromal cells with activated PPARγ display metabolic features of cancer-associated fibroblasts, with increased autophagy, glycolysis and senescence. Indeed, fibroblasts overexpressing PPARγ show increased expression of autophagic markers, increased numbers of acidic autophagic vacuoles, increased production of L-lactate, cell hypertrophy and mitochondrial dysfunction. In addition, PPARγ fibroblasts show increased expression of CDKs (p16/p21) and β-galactosidase, which are markers of cell cycle arrest and senescence. Finally, PPARγ induces the activation of the two major transcription factors that promote autophagy and glycolysis, i.e., HIF-1α and NFκB, in stromal cells. Thus, PPARγ activation in stromal cells results in the formation of a catabolic pro-inflammatory microenvironment that metabolically supports cancer growth. Interestingly, the tumor inhibition observed when PPARγ is

  9. The OpenGeoSys coupling concept for THMC processes in subsurface and the neighboring hydro-compartments

    NASA Astrophysics Data System (ADS)

    Kalbacher, T.; Delfs, J. O.; Shao, H.; Boettcher, N.; Walther, M.; Kolditz, O.

    2012-12-01

    State-of-the-art computational models used for integrated water resources management are rapidly developing instruments. Advances in computational mathematics have revolutionized the variety and the nature of the problems that can be addressed by environmental scientists and engineers. For each hydro-compartment, from precipitation and surface run-off to catchment water balance and groundwater interactions, there exist many excellent simulation codes. However, their development has been isolated within different disciplines. The OpenGeoSys (OGS) project is a scientific open source initiative for numerical simulation of thermo-hydro-mechanical-chemical (THMC) processes in porous and fractured media. The basic concept is to provide a flexible numerical framework (using primarily the Finite Element Method (FEM)) for solving multi-field problems in porous and fractured media for applications in geoscience and hydrology. To this purpose, OGS is based on an object-oriented FEM concept including a broad spectrum of interfaces for pre- and post-processing. The idea includes a web-based platform for community access, outfitted with professional software engineering tools such as platform-independent compiling and fully automated benchmarking. The second strategy is to utilize an additional coupling concept that enables OGS simulations to interact sequentially with other individual modeling software in order to address coupled processes in neighboring hydrologic compartments, which includes methods of coupling different physical processes and different geometric model complexities under consideration of the spatial and temporal scale change and the required computational resources. The IWAS ToolBox concept.

  10. Loss of BMP signaling through BMPR1A in osteoblasts leads to greater collagen cross-link maturation and material-level mechanical properties in mouse femoral trabecular compartments.

    PubMed

    Zhang, Yanshuai; McNerny, Erin Gatenby; Terajima, Masahiko; Raghavan, Mekhala; Romanowicz, Genevieve; Zhang, Zhanpeng; Zhang, Honghao; Kamiya, Nobuhiro; Tantillo, Margaret; Zhu, Peizhi; Scott, Gregory J; Ray, Manas K; Lynch, Michelle; Ma, Peter X; Morris, Michael D; Yamauchi, Mitsuo; Kohn, David H; Mishina, Yuji

    2016-07-01

    Bone morphogenetic protein (BMP) signaling pathways play critical roles in skeletal development and new bone formation. Our previous study, however, showed a negative impact of BMP signaling on bone mass because of the osteoblast-specific loss of a BMP receptor (i.e. BMPR1A) showing increased trabecular bone volume and mineral density in mice. Here, we investigated the bone quality and biomechanical properties of the higher bone mass associated with BMPR1A deficiency using the osteoblast-specific Bmpr1a conditional knockout (cKO) mouse model. Collagen biochemical analysis revealed greater levels of the mature cross-link pyridinoline in the cKO bones, in parallel with upregulation of collagen modifying enzymes. Raman spectroscopy distinguished increases in the mature to immature cross-link ratio and mineral to matrix ratio in the trabecular compartments of cKO femora, but not in the cortical compartments. The mineral crystallinity was unchanged in the cKO in either the trabecular or cortical compartments. Further, we tested the intrinsic material properties by nanoindentation and found significantly higher hardness and elastic modulus in the cKO trabecular compartments, but not in the cortical compartments. Four point bending tests of cortical compartments showed lower structural biomechanical properties (i.e. strength and stiffness) in the cKO bones due to the smaller cortical areas. However, there were no significant differences in biomechanical performance at the material level, which was consistent with the nanoindentation test results on the cortical compartment. These studies emphasize the pivotal role of BMPR1A in the determination of bone quality and mechanical integrity under physiological conditions, with different impact on femoral cortical and trabecular compartments.

  11. 46 CFR 105.25-5 - Compartments or areas containing cargo tanks or pumping systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Requirements-When Cargo Tanks Are Installed Below Decks § 105.25-5 Compartments or areas containing cargo tanks... drive shaft and pump engine control rods if such openings are fitted with stuffing boxes or...

  12. Hemorrhoid sclerotherapy with the complication of abdominal compartment syndrome: report of a case.

    PubMed

    Yang, Peng; Wang, Ya-Jun; Li, Fei; Sun, Jia-Bang

    2011-06-01

    The complications of injection sclerotherapy for hemorrhoid are always local. Herein, we report a case in which a female patient with abdominal compartment syndrome developed after receiving a local injection of a sclerosing agent for hemorrhoid.

  13. LEG'S COMPARTMENT SYNDROME AFTER RECONSTRUCTION OF THE ANTERIOR CRUCIATE LIGAMENT: CASE REPORT.

    PubMed

    Filho, Jorge Sayum; Ramos, Leonardo Adeo; Sayum, Jorge; de Carvalho, Rogério Teixeira; Ejnisman, Benno; Matsuda, Marcelo Mitsuro; Nicolini, Alexandre; Cohen, Moisés

    2011-01-01

    The authors report a case of a patient that was submitted to a surgery of reconstruction of anterior cruciate ligament and collateral medial ligament repair of the left knee that complicated to a compartment syndrome.

  14. Compartment B3, boiler room; showing boiler facing of boiler #5 ...

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

    Compartment B-3, boiler room; showing boiler facing of boiler #5 aft to forward from passing room B-25. (030A) - USS Olympia, Penn's Landing, 211 South Columbus Boulevard, Philadelphia, Philadelphia County, PA

  15. STS-35 Pilot Gardner in sleep station compartment on OV-102's middeck

    NASA Technical Reports Server (NTRS)

    1990-01-01

    STS-35 Pilot Guy S. Gardner demonstrates the bunk-style sleep compartments onboard Columbia's, Orbiter Vehicle (OV) 102's, middeck. Gardner uses bunk #2 of the sleep station located against the middeck starboard wall.

  16. Compartment A14m cork lined powder magazine looking port to ...

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

    Compartment A-14m - cork lined powder magazine looking port to starboard; note temperature sensor in the overhead. (022) - USS Olympia, Penn's Landing, 211 South Columbus Boulevard, Philadelphia, Philadelphia County, PA

  17. 30 CFR 57.19107 - Precautions for work in compartment affected by hoisting operation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... AND NONMETAL MINES Personnel Hoisting Shafts § 57.19107 Precautions for work in compartment affected... by that hoisting operation and a “Men Working in Shaft” sign shall be posted at the hoist....

  18. Rna-seq analysis of the functional compartments within the rat placentation site

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The rat placentation site is distinctly organized into interacting zones, the so-called labyrinth, junctional, and metrial gland compartments. These zones house unique cell populations equipped to undertake myriad prescribed functions including transport, hormonal responses, and immune interactions....

  19. A delayed presentation of bilateral leg compartment syndrome following non-stop dancing.

    PubMed

    Jefferies, James Gordon; Carter, Tom; White, Tim Oliver

    2015-03-18

    We present the case of a young man with a 48 h delayed presentation of bilateral lower limb acute compartment syndrome (ACS) affecting the anterior compartments following an extended period of dancing at a music festival. On making the diagnosis of ACS, the patient was immediately taken to theatre for fasciotomies and compartmental decompression. Repeat look fasciotomies revealed further necrosis to the muscles of the anterior compartments bilaterally and, effectively, all the muscle bellies within the anterior compartments were excised. The patient has been left with a significant functional deficit and disability. This case highlights the importance of timely diagnosis of ACS as delay in presentation can impact significantly on subsequent functional outcome and quality of life.

  20. Synchronous compartment temperature control and apparatus for refrigeration with reduced energy consumption

    DOEpatents

    Gomes, Alberto Regio; Keres, Stephen L.; Kuehl, Stephen J.; Litch, Andrew D.; Richmond, Peter J.; Wu, Guolian

    2015-09-22

    A refrigerator appliance configuration, and associated methods of operation, for an appliance with a controller, a condenser, at least one evaporator, a compressor, and two refrigeration compartments. The configuration may be equipped with a variable-speed or variable-capacity compressor, variable speed evaporator or compartment fans, a damper and/or a dual-temperature evaporator with a valve system to control flow of refrigerant through one or more pressure reduction devices. The controller, by operation of the compressor, fans, damper and/or valve system, depending on the appliance configuration, controls the cooling rate in one or both compartments to synchronize, alternating cycles of cooling the compartments to their set point temperatures.

  1. Something Silent This Way Forms: The Functional Organization of the Repressive Nuclear Compartment

    PubMed Central

    Ritland Politz, Joan C.; Scalzo, David; Groudine, Mark

    2014-01-01

    The repressive compartment of the nucleus is comprised primarily of telomeric and centromeric regions, the silent portion of ribosomal RNA genes, the majority of transposable element repeats, and facultatively repressed genes specific to different cell types. This compartment localizes into three main regions: the peripheral heterochromatin, perinucleolar heterochromatin, and pericentromeric heterochromatin. Both chromatin remodeling proteins and transcription of noncoding RNAs are involved in maintenance of repression in these compartments. Global reorganization of the repressive compartment occurs at each cell division, during early development, and during terminal differentiation. Differential action of chromatin remodeling complexes and boundary element looping activities are involved in mediating these organizational changes. We discuss the evidence that heterochromatin formation and compartmentalization may drive nuclear organization. PMID:23834025

  2. DISTRIBUTION OF TOTAL AND METHYLMERCURY IN DIFFERENT ECOSYSTEM COMPARTMENTS IN THE EVERGLADES: IMPLICATIONS FOR MERCURY BIOACCUMULATION

    EPA Science Inventory

    Mercury (Hg) species distribution patterns among ecosystem compartments in the Everglades were analyzed at the landscape level in order to explore the implications of Hg distribution for Hg bioaccumulation, and to investigate major biogeochemical processes that are pertinent to t...

  3. 14 CFR 25.819 - Lower deck service compartments (including galleys).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... lower deck service compartment, that indicates when seat belts should be fastened. (e) If a public... aft facing seat which meets the requirements of § 25.785(d), and must be able to withstand...

  4. 14 CFR 25.819 - Lower deck service compartments (including galleys).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... lower deck service compartment, that indicates when seat belts should be fastened. (e) If a public... aft facing seat which meets the requirements of § 25.785(d), and must be able to withstand...

  5. Lysosome-like compartments of Trypanosoma cruzi trypomastigotes may originate directly from epimastigote reservosomes.

    PubMed

    Vidal, Juliana C; Alcantara, Carolina DE L; DE Souza, Wanderley; Cunha-E-Silva, Narcisa L

    2017-01-12

    Trypanosoma cruzi epimastigote reservosomes store nutrients taken up during the intense endocytic activity exhibited by this developmental form. Reservosomes were classified as pre-lysosomal compartments. In contrast, trypomastigote forms are not able to take up nutrients from the medium. Interestingly, trypomastigotes also have acidic organelles with the same proteases contained in epimastigote reservosomes. Nevertheless, the origin and function of these organelles have not been disclosed so far. Given the similarities between the compartments of epimastigotes and trypomastigotes, the present study aimed to investigate the origin of metacyclic trypomastigote protease-containing organelles by tracking fluorospheres or colloidal gold particles previously stored in epimastigotes' reservosomes throughout metacyclogenesis. Using three-dimensional reconstruction of serial electron microscopy images, it was possible to find trypomastigote compartments containing the tracer. Our observations demonstrate that the protease-containing compartments from metacyclic trypomastigotes may originate directly from the reservosomes of epimastigotes.

  6. LEG'S COMPARTMENT SYNDROME AFTER RECONSTRUCTION OF THE ANTERIOR CRUCIATE LIGAMENT: CASE REPORT

    PubMed Central

    Filho, Jorge Sayum; Ramos, Leonardo Adeo; Sayum, Jorge; de Carvalho, Rogério Teixeira; Ejnisman, Benno; Matsuda, Marcelo Mitsuro; Nicolini, Alexandre; Cohen, Moisés

    2015-01-01

    The authors report a case of a patient that was submitted to a surgery of reconstruction of anterior cruciate ligament and collateral medial ligament repair of the left knee that complicated to a compartment syndrome. PMID:27047834

  7. CO2 Capture in the Sustainable Wheat-Derived Activated Microporous Carbon Compartments

    NASA Astrophysics Data System (ADS)

    Hong, Seok-Min; Jang, Eunji; Dysart, Arthur D.; Pol, Vilas G.; Lee, Ki Bong

    2016-10-01

    Microporous carbon compartments (MCCs) were developed via controlled carbonization of wheat flour producing large cavities that allow CO2 gas molecules to access micropores and adsorb effectively. KOH activation of MCCs was conducted at 700 °C with varying mass ratios of KOH/C ranging from 1 to 5, and the effects of activation conditions on the prepared carbon materials in terms of the characteristics and behavior of CO2 adsorption were investigated. Textural properties, such as specific surface area and total pore volume, linearly increased with the KOH/C ratio, attributed to the development of pores and enlargement of pores within carbon. The highest CO2 adsorption capacities of 5.70 mol kg‑1 at 0 °C and 3.48 mol kg‑1 at 25 °C were obtained for MCC activated with a KOH/C ratio of 3 (MCC-K3). In addition, CO2 adsorption uptake was significantly dependent on the volume of narrow micropores with a pore size of less than 0.8 nm rather than the volume of larger pores or surface area. MCC-K3 also exhibited excellent cyclic stability, facile regeneration, and rapid adsorption kinetics. As compared to the pseudo-first-order model, the pseudo-second-order kinetic model described the experimental adsorption data methodically.

  8. CO2 Capture in the Sustainable Wheat-Derived Activated Microporous Carbon Compartments

    PubMed Central

    Hong, Seok-Min; Jang, Eunji; Dysart, Arthur D.; Pol, Vilas G.; Lee, Ki Bong

    2016-01-01

    Microporous carbon compartments (MCCs) were developed via controlled carbonization of wheat flour producing large cavities that allow CO2 gas molecules to access micropores and adsorb effectively. KOH activation of MCCs was conducted at 700 °C with varying mass ratios of KOH/C ranging from 1 to 5, and the effects of activation conditions on the prepared carbon materials in terms of the characteristics and behavior of CO2 adsorption were investigated. Textural properties, such as specific surface area and total pore volume, linearly increased with the KOH/C ratio, attributed to the development of pores and enlargement of pores within carbon. The highest CO2 adsorption capacities of 5.70 mol kg−1 at 0 °C and 3.48 mol kg−1 at 25 °C were obtained for MCC activated with a KOH/C ratio of 3 (MCC-K3). In addition, CO2 adsorption uptake was significantly dependent on the volume of narrow micropores with a pore size of less than 0.8 nm rather than the volume of larger pores or surface area. MCC-K3 also exhibited excellent cyclic stability, facile regeneration, and rapid adsorption kinetics. As compared to the pseudo-first-order model, the pseudo-second-order kinetic model described the experimental adsorption data methodically. PMID:27698448

  9. Study on 3-D simulation of flow and turbidity in an oxbow lake in tidal compartment

    NASA Astrophysics Data System (ADS)

    Yokoyama, H.; Momonoe, H.; Hamamoto, S.

    2010-12-01

    We aimed to make flow and turbidity simulation model for an oxbow lake in tidal compartment. The oxbow has two bottle-necks and inflow river from urban district. Bed topography of the oxbow is former meandering channel of large-basin river. Therefore characteristic of flow and water quality is complex. First, field observation was conducted to clarify the characteristics of flow and water quality in the oxbow. From observation results, flow and resuspension phenomena in the oxbow were affected by wind and tide, and the balance of the two factors changed longitudinally. Next, we built 3-D simulation model of flow which took account of the field observation results. In order to investigate effective water quality improvement, we set some test cases: condition of wind, inflow river were changed. From the simulation results, tide was the most important factor, however at the upper part of the oxbow, where the tidal power seemed to be weaker, flow and turbidity were clearly affected by the wind.

  10. The endocytic recycling compartment maintains cargo segregation acquired upon exit from the sorting endosome

    PubMed Central

    Xie, Shuwei; Bahl, Kriti; Reinecke, James B.; Hammond, Gerald R. V.; Naslavsky, Naava; Caplan, Steve

    2016-01-01

    The endocytic recycling compartment (ERC) is a series of perinuclear tubular and vesicular membranes that regulates recycling to the plasma membrane. Despite evidence that cargo is sorted at the early/sorting endosome (SE), whether cargo mixes downstream at the ERC or remains segregated is an unanswered question. Here we use three-dimensional (3D) structured illumination microscopy and dual-channel and 3D direct stochastic optical reconstruction microscopy (dSTORM) to obtain new information about ERC morphology and cargo segregation. We show that cargo internalized either via clathrin-mediated endocytosis (CME) or independently of clathrin (CIE) remains segregated in the ERC, likely on distinct carriers. This suggests that no further sorting occurs upon cargo exit from SE. Moreover, 3D dSTORM data support a model in which some but not all ERC vesicles are tethered by contiguous “membrane bridges.” Furthermore, tubular recycling endosomes preferentially traffic CIE cargo and may originate from SE membranes. These findings support a significantly altered model for endocytic recycling in mammalian cells in which sorting occurs in peripheral endosomes and segregation is maintained at the ERC. PMID:26510502

  11. Architectural properties of the neuromuscular compartments in selected forearm skeletal muscles.

    PubMed

    Liu, An-Tang; Liu, Ben-Li; Lu, Li-Xuan; Chen, Gang; Yu, Da-Zhi; Zhu, Lie; Guo, Rong; Dang, Rui-Shan; Jiang, Hua

    2014-07-01

    The purposes f this study were to (i) explore the possibility of splitting the selected forearm muscles into separate compartments in human subjects; (ii) quantify the architectural properties of each neuromuscular compartment; and (iii) discuss the implication of these properties in split tendon transfer procedures. Twenty upper limbs from 10 fresh human cadavers were used in this study. Ten limbs of five cadavers were used for intramuscular nerve study by modified Sihler's staining technique, which confirmed the neuromuscular compartments. The other 10 limbs were included for architectural analysis of neuromuscular compartments. The architectural features of the compartments including muscle weight, muscle length, fiber length, pennation angle, and sarcomere length were determined. Physiological cross-sectional area and fiber length/muscle length ratio were calculated. Five of the selected forearm muscles were ideal candidates for splitting, including flexor carpi ulnaris, flexor carpi radials, extensor carpi radialis brevis, extensor carpi ulnaris and pronator teres. The humeral head of pronator teres contained the longest fiber length (6.23 ± 0.31 cm), and the radial compartment of extensor carpi ulnaris contained the shortest (2.90 ± 0.28 cm). The ulnar compartment of flexor carpi ulnaris had the largest physiological cross-sectional area (5.17 ± 0.59 cm(2)), and the ulnar head of pronator teres had the smallest (0.67 ± 0.06 cm(2)). Fiber length/muscle length ratios of the neuromuscular compartments were relatively low (average 0.27 ± 0.09, range 0.18-0.39) except for the ulnar head of pronator teres, which had the highest one (0.72 ± 0.05). Using modified Sihler's technique, this research demonstrated that each compartment of these selected forearm muscles has its own neurovascular supply after being split along its central tendon. Data of the architectural properties of each neuromuscular compartment provide insight into the 'design' of their

  12. Intramuscular deoxygenation during exercise in patients who have chronic anterior compartment syndrome of the leg

    NASA Technical Reports Server (NTRS)

    Mohler, L. R.; Styf, J. R.; Pedowitz, R. A.; Hargens, A. R.; Gershuni, D. H.

    1997-01-01

    Currently, the definitive diagnosis of chronic compartment syndrome is based on invasive measurements of intracompartmental pressure. We measured the intramuscular pressure and the relative oxygenation in the anterior compartment of the leg in eighteen patients who were suspected of having chronic compartment syndrome as well as in ten control subjects before, during, and after exercise. Chronic compartment syndrome was considered to be present if the intramuscular pressure was at least fifteen millimeters of mercury (2.00 kilopascals) before exercise, at least thirty millimeters of mercury (4.00 kilopascals) one minute after exercise, or at least twenty millimeters of mercury (2.67 kilopascals) five minutes after exercise. Changes in relative oxygenation were measured with use of the non-invasive method of near-infrared spectroscopy. In all patients and subjects, there was rapid relative deoxygenation after the initiation of exercise, the level of oxygenation remained relatively stable during continued exercise, and there was reoxygenation to a level that exceeded the pre-exercise resting level after the cessation of exercise. During exercise, maximum relative deoxygenation in the patients who had chronic compartment syndrome (mean relative deoxygenation [and standard error], -290 +/- 39 millivolts) was significantly greater than that in the patients who did not have chronic compartment syndrome (-190 +/- 10 millivolts) and that in the control subjects (-179 +/- 14 millivolts) (p < 0.05 for both comparisons). In addition, the interval between the cessation of exercise and the recovery of the pre-exercise resting level of oxygenation was significantly longer for the patients who had chronic compartment syndrome (184 +/- 54 seconds) than for the patients who did not have chronic compartment syndrome (39 +/- 19 seconds) and the control subjects (33 +/- 10 seconds) (p < 0.05 for both comparisons).

  13. Monitoring solute fluxes: Integrating electrical resistivity with multi-compartment sampler techniques

    NASA Astrophysics Data System (ADS)

    Bloem, Esther; Fernandez, Perrine; French, Helen K.

    2016-04-01

    The impact of agriculture, industry, airport activities on soil and water quality is strongly influenced by soil heterogeneity. To improve risk assessment, monitoring, and treatment strategies, we require a better understanding of the effect of soil heterogeneity on contaminant movement and better methods for monitoring heterogeneous contaminated transport. Sufficient characterization of spatial and temporal distribution of contaminant transport requires measurements of water and solute fluxes at multiple locations with a high temporal resolution. During this presentation, we will show a newly developed instrument, which combines multi-compartment sampling with electrical resistivity measurements, to observe spatial and temporal fluxes of contaminants. Solute monitoring is often limited to observations of resident concentrations, while flux concentrations govern the movement of solutes in soils. Bloem et al. (2010) developed a multi-compartment sampler (MCS) which is capable of measuring fluxes at a high spatial resolution under natural conditions. The sampler is divided into 100 separate compartments of 31 by 31 mm. Flux data can be recorded at a high time resolution (every 5 minutes). Tracer leaching can be monitored by frequently sampling the collected leachate while leaving the sampler buried in situ. To optimize the monitoring of tracer leaching and measure real solute fluxes the multi-compartment sampler has been extended with 121 electrodes. The electrodes are mounted at each corner of each compartment to measure the electrical conductivity above each compartment while water percolates through the compartments. By using different electrode couples, the setup can also be used to image above the multi-compartment sampler. The instrument can be used for detailed studies both in the laboratory and in the field. For laboratory experiments a transparent column is used which fits perfect on top of the MCS. We present a selection of the integrated electrical

  14. Compartment syndrome following total knee replacement: A case report and literature review

    PubMed Central

    Shaath, Mohammed; Sukeik, Mohamed; Mortada, Saadallah; Masterson, Sean

    2016-01-01

    Compartment syndrome is a rare complication of total knee replacement (TKR) surgery that needs prompt diagnosis and treatment as it may be associated with high morbidity and mortality. We have found very few reports in the literature describing compartment syndrome after TKRs and therefore, present a relevant case which occurred in the immediate postoperative phase and was treated with fasciotomy and subsequent operations to close the soft tissue defects. PMID:27672575

  15. Compartment A4 hold at midplatform level, view from starboard to ...

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

    Compartment A-4 hold at mid-platform level, view from starboard to port shows protective deck framing and underside of armor plate. Open wood ceiling aids in circulating air. Note ventilation duct for fresh air at center of photograph. Open hatch penetrates protective deck and leads to bread room, compartment A-102. (012) - USS Olympia, Penn's Landing, 211 South Columbus Boulevard, Philadelphia, Philadelphia County, PA

  16. TU-F-12A-01: Quantitative Non-Linear Compartment Modeling of 89Zr- and 124I- Labeled J591 Monoclonal Antibody Kinetics Using Serial Non-Invasive Positron Emission Tomography Imaging in a Pre-Clinical Human Prostate Cancer Mouse Model

    SciTech Connect

    Fung, EK; Cheal, SM; Chalasani, S; Fareedy, SB; Punzalan, B; Humm, JL; Osborne, JR; Larson, SM; Zanzonico, PB; Otto, B; Bander, NH

    2014-06-15

    Purpose: To examine the binding kinetics of human IgG monoclonal antibody J591 which targets prostate-specific membrane antigen (PSMA) in a pre-clinical mouse cancer model using quantitative PET compartmental analysis of two radiolabeled variants. Methods: PSMA is expressed in normal human prostate, and becomes highly upregulated in prostate cancer, making it a promising therapeutic target. Two forms of J591, radiolabeled with either {sup 89}Zr or {sup 124}I, were prepared. {sup 89}Zr is a radiometal that becomes trapped in the cell upon internalization by the antigen-antibody complex, while radioiodine leaves the cell. Mice with prostate cancer xenografts underwent non-invasive serial imaging on a Focus 120 microPET up to 144 hours post-injection of J591. A non-linear compartmental model describing the binding and internalization of antibody in tumor xenograft was developed and applied to the PET-derived time-activity curves. The antibody-antigen association rate constant (ka), total amount of antigen per gram tumor (Ag-total), internalization rate of antibody-antigen complex, and efflux rate of radioisotope from tumor were fitted using the model. The surface-bound and the internalized activity were also estimated. Results: Values for ka, Ag-total, and internalization rate were found to be similar regardless of radiolabel payload used. The efflux rate, however, was ∼ 9-fold higher for {sup 124}I-J591 than for {sup 89}Zr-J591. Time-dependent surface-bound and internalized radiotracer activity were similar for both radiolabels at early times post-injection, but clearly differed beyond 24 hours. Conclusion: Binding and internalization of J591 to PSMA-expressing tumor xenografts were similar when radiolabeled with either {sup 89}Zr or {sup 124}I payload. The difference in efflux of radioactivity from tumor may be attributable to differential biological fate intracellularly of the radioisotopes. This has great significance for radioimmunotherapy and antibody

  17. Hadron calorimeter performance with a PbWO4 EM compartment

    SciTech Connect

    Green, D.

    1996-01-01

    The CMS detector[1] at the LHC has chosen PbWO4 in order to achieve the superior photon energy resolution which is crucial in searching for the 2 photon decay of low mass Higgs bosons. The hadronic compartment is thought to be Cu absorber, since one is immersed in a 4 T magnetic field, read out by scintillator tiles coupled to wavelength shifter (WLS) fibers. The combined performance of this calorimeter is of interest in the study of jets and missing transverse energy (neutrino, SUSY signatures). For this reason, a test was made of the electromagnetic (EM) compartment combined with a reasonable approximation to the baseline HCAL ``barrel`` calorimeter. Data was taken in the H4 CERN beamline. The EM compartment was a 7 {times} 7 square array of PbWO4 crystals, which for the purposes of this study are considered as a single readout in depth (or ``compartment``) [2]. The HCAL module consisted of large scintillator plates with 24 individual longitudinal readout channels. The EM compartment was followed by 10 Cu plates each 3 cm thick, followed by 9 Cu plates each 6 cm thick. This set of absorber plates represented the HCAL compartments inside the coil. The coil itself [1] was approximated as Al and Fe plates, of a total thickness of about 1.4 absorption lengths. The coil mockup was sampled and then followed by 4 plates of 8 cm thick Cu, each with an individual readout which represented a test of the ``Tailcatcher`` concept.

  18. The longest telomeres: a general signature of adult stem cell compartments

    PubMed Central

    Flores, Ignacio; Canela, Andres; Vera, Elsa; Tejera, Agueda; Cotsarelis, George; Blasco, María A.

    2008-01-01

    Identification of adult stem cells and their location (niches) is of great relevance for regenerative medicine. However, stem cell niches are still poorly defined in most adult tissues. Here, we show that the longest telomeres are a general feature of adult stem cell compartments. Using confocal telomere quantitative fluorescence in situ hybridization (telomapping), we find gradients of telomere length within tissues, with the longest telomeres mapping to the known stem cell compartments. In mouse hair follicles, we show that cells with the longest telomeres map to the known stem cell compartments, colocalize with stem cell markers, and behave as stem cells upon treatment with mitogenic stimuli. Using K15-EGFP reporter mice, which mark hair follicle stem cells, we show that GFP-positive cells have the longest telomeres. The stem cell compartments in small intestine, testis, cornea, and brain of the mouse are also enriched in cells with the longest telomeres. This constitutes the description of a novel general property of adult stem cell compartments. Finally, we make the novel finding that telomeres shorten with age in different mouse stem cell compartments, which parallels a decline in stem cell functionality, suggesting that telomere loss may contribute to stem cell dysfunction with age. PMID:18283121

  19. Differential activity of Drosophila Hox genes induces myosin expression and can maintain compartment boundaries.

    PubMed

    Curt, Jesús R; de Navas, Luis F; Sánchez-Herrero, Ernesto

    2013-01-01

    Compartments are units of cell lineage that subdivide territories with different developmental potential. In Drosophila, the wing and haltere discs are subdivided into anterior and posterior (A/P) compartments, which require the activity of Hedgehog, and into dorsal and ventral (D/V) compartments, needing Notch signaling. There is enrichment in actomyosin proteins at the compartment boundaries, suggesting a role for these proteins in their maintenance. Compartments also develop in the mouse hindbrain rhombomeres, which are characterized by the expression of different Hox genes, a group of genes specifying different structures along their main axis of bilaterians. We show here that the Drosophila Hox gene Ultrabithorax can maintain the A/P and D/V compartment boundaries when Hedgehog or Notch signaling is compromised, and that the interaction of cells with and without Ultrabithorax expression induces high levels of non-muscle myosin II. In the absence of Ultrabithorax there is occasional mixing of cells from different segments. We also show a similar role in cell segregation for the Abdominal-B Hox gene. Our results suggest that the juxtaposition of cells with different Hox gene expression leads to their sorting out, probably through the accumulation of non-muscle myosin II at the boundary of the different cell territories. The increase in myosin expression seems to be a general mechanism used by Hox genes or signaling pathways to maintain the segregation of different groups of cells.

  20. A hybrid algorithm for coupling partial differential equation and compartment-based dynamics

    PubMed Central

    Yates, Christian A.

    2016-01-01

    Stochastic simulation methods can be applied successfully to model exact spatio-temporally resolved reaction–diffusion systems. However, in many cases, these methods can quickly become extremely computationally intensive with increasing particle numbers. An alternative description of many of these systems can be derived in the diffusive limit as a deterministic, continuum system of partial differential equations (PDEs). Although the numerical solution of such PDEs is, in general, much more efficient than the full stochastic simulation, the deterministic continuum description is generally not valid when copy numbers are low and stochastic effects dominate. Therefore, to take advantage of the benefits of both of these types of models, each of which may be appropriate in different parts of a spatial domain, we have developed an algorithm that can be used to couple these two types of model together. This hybrid coupling algorithm uses an overlap region between the two modelling regimes. By coupling fluxes at one end of the interface and using a concentration-matching condition at the other end, we ensure that mass is appropriately transferred between PDE- and compartment-based regimes. Our methodology gives notable reductions in simulation time in comparison with using a fully stochastic model, while maintaining the important stochastic features of the system and providing detail in appropriate areas of the domain. We test our hybrid methodology robustly by applying it to several biologically motivated problems including diffusion and morphogen gradient formation. Our analysis shows that the resulting error is small, unbiased and does not grow over time. PMID:27628171

  1. Matrix metalloproteinase-9 expression in the nuclear compartment of neurons and glial cells in aging and stroke.

    PubMed

    Pirici, Daniel; Pirici, Ionica; Mogoanta, Laurentiu; Margaritescu, Otilia; Tudorica, Valerica; Margaritescu, Claudiu; Ion, Daniela A; Simionescu, Cristiana; Coconu, Marieta

    2012-10-01

    Matrix metalloproteinases (MMPs) are well-recognized denominators for extracellular matrix remodeling in the pathology of both ischemic and hemorrhagic strokes. Recent data on non-nervous system tissue showed intracellular and even intranuclear localizations for different MMPs, and together with this, a plethora of new functions have been proposed for these intracellular active enzymes, but are mostly related to apoptosis induction and malign transformation. In neurons and glial cells, on human tissue, animal models and cell cultures, different active MMPs have been also proven to be located in the intra-cytoplasmic or intra-nuclear compartments, with no clear-cut function. In the present study we show for the first time on human tissue the nuclear expression of MMP-9, mainly in neurons and to a lesser extent in astrocytes. We have studied ischemic and hemorrhagic stroke patients, as well as aged control patients. Age and ischemic suffering seemed to be the best predictors for an elevated MMP-9 nuclear expression, and there was no evidence of a clear-cut extracellular proteolytic activity for this compartment, as revealed by intact vascular basement membranes and assessment of vascular densities. More, the majority of the cells expressing MMP-9 in the nuclear compartment also co-expressed activated-caspase 3, indicating a possible link between nuclear MMP-9 localization and apoptosis in neuronal and glial cells following an ischemic or hemorrhagic event. These results, besides showing for the first time the nuclear localization of MMP-9 on a large series of human stroke and aged brain tissues, raise new questions regarding the unknown spectrum of the functions MMPs in human CNS pathology.

  2. Associations among Inflammatory Biomarkers in the Circulating, Plasmatic, Salivary and Intraluminal Anatomical Compartments in Apparently Healthy Preschool Children from the Western Highlands of Guatemala

    PubMed Central

    Soto-Méndez, María José; Romero-Abal, María Eugenia; Aguilera, Concepción María; Rico, María Cruz; Solomons, Noel W.; Schümann, Klaus; Gil, Angel

    2015-01-01

    Background Undernutrition and inflammation are related in many ways; for instance, non-hygienic environments are associated with both poor growth and immunostimulation in children. Objective To describe any existing interaction among different inflammation biomarkers measured in the distinct anatomical compartments of whole blood, feces, plasma and saliva. Methods In this descriptive, cross-sectional study, samples of whole blood, feces, plasma and saliva were collected on the 8th and last week of observation among 87 attendees (42 girls and 45 boys) of 3 daycare centers offering a common 40-day rotating menu in Guatemala’s Western Highlands. Analyses included white blood cell count (WBC), fecal calprotectin, and plasmatic and salivary cytokines including IL-1B, IL-6, IL-8, IL-10 and TNF-α. Associations were assessed using Spearman rank-order and goodness-of-fit correlations, as indicated, followed by backwards-elimination multiple regression analyses to determine predictor variables for IL-10 in both anatomical compartments. Results Of a total of 66 cross-tabulations in the Spearman hemi-matrix, 22 (33%) were significantly associated. All 10 paired associations among the salivary cytokines had a significant r value, whereas 7 of 10 possible associations among plasma cytokines were significant. Associations across anatomical compartments, however, were rarely significant. IL-10 in both biological fluids were higher than corresponding reference values. When a multiple regression model was run in order to determine independent predictors for IL-10 in each anatomical compartment separately, IL-6, IL-8 and TNF-α emerged as predictors in plasma (r2 = 0.514) and IL-1B, IL-8 and TNF-α remained as independent predictors in saliva (r2 = 0.762). Significant cross-interactions were seen with WBC, but not with fecal calprotectin. Conclusion Interactions ranged from robust within the same anatomical compartment to limited to nil across distinct anatomical compartments. The

  3. Spatial and temporal changes in the Barents Sea pelagic compartment during the recent warming

    NASA Astrophysics Data System (ADS)

    Eriksen, Elena; Skjoldal, Hein Rune; Gjøsæter, Harald; Primicerio, Raul

    2017-02-01

    The Barents Sea has experienced substantial warming over the last few decades with expansion of relatively warm Atlantic water and reduction in sea ice. Based on a review of relevant literature and additional analyses, we report changes in the pelagic compartment associated with this warming using data from autumn surveys (acoustic capelin, 0-group fish, and ecosystem surveys). We estimated biomass for 25 components of the pelagic community, including macroplankton, 0-group fish, and juvenile and adult pelagic fish, were examined for spatial and temporal variation over the period 1993-2013. The estimated total biomass of the investigated pelagic compartment, not including mesozooplankton, ranged between about 6 and 30 million tonnes wet weight with an average of 17 million tonnes over the 21-years period. Krill was the dominant biomass component (63%), whereas pelagic fish (capelin, polar cod and herring) made up 26% and 0-group fish 11% of the biomass on average. The spatial distribution of biomass showed a broad-scale pattern reflecting differences in distribution of the main pelagic fishes (capelin in the north, polar cod in the east, and herring in the south) and transport of krill and 0-group fish with the Atlantic water flowing into the southern Barents Sea. Dividing the Barents Sea into six regions, the highest average biomass values were found in the Southwestern and South-Central subareas (about 4 million tonnes in each), with krill as the main component. Biomass was also high in the North-Central subarea (about 3 million tonnes) where capelin was the major contributor. The total estimated biomass of the pelagic compartment remained relatively stable during each of two main periods (before and after 2004), but increased by a factor of two from around 11 million tonnes in the first to around 23 million tonnes in the last period. The pronounced increase reflected the warming between the relatively cold 1990s and the warmer 2000s and was driven mainly by an

  4. A hybrid method for efficient and accurate simulations of diffusion compartment imaging signals

    NASA Astrophysics Data System (ADS)

    Rensonnet, Gaëtan; Jacobs, Damien; Macq, Benoît; Taquet, Maxime

    2015-12-01

    Diffusion-weighted imaging is sensitive to the movement of water molecules through the tissue microstructure and can therefore be used to gain insight into the tissue cellular architecture. While the diffusion signal arising from simple geometrical microstructure is known analytically, it remains unclear what diffusion signal arises from complex microstructural configurations. Such knowledge is important to design optimal acquisition sequences, to understand the limitations of diffusion-weighted imaging and to validate novel models of the brain microstructure. We present a novel framework for the efficient simulation of high-quality DW-MRI signals based on the hybrid combination of exact analytic expressions in simple geometric compartments such as cylinders and spheres and Monte Carlo simulations in more complex geometries. We validate our approach on synthetic arrangements of parallel cylinders representing the geometry of white matter fascicles, by comparing it to complete, all-out Monte Carlo simulations commonly used in the literature. For typical configurations, equal levels of accuracy are obtained with our hybrid method in less than one fifth of the computational time required for Monte Carlo simulations.

  5. Preparation and maintenance of dorsal root ganglia neurons in compartmented cultures.

    PubMed

    Pazyra-Murphy, Maria F; Segal, Rosalind A

    2008-10-17

    Neurons extend axonal processes that are far removed from the cell body to innervate target tissues, where target-derived growth factors are required for neuronal survival and function. Neurotrophins are specifically required to maintain the survival and differentiation of innervating sensory neurons but the question of how these target-derived neurotrophins communicate to the cell body of innervating neurons has been an area of active research for over 30 years. The most commonly accepted model of how neurotrophin signals reach the cell body proposes that signaling endosomes carry this signal retrogradely along the axon. In order to study retrograde transport, a culture system was originally devised by Robert Campenot, in which cell bodies are isolated from their axons. The technique of preparing these compartmented chambers for culturing sensory neurons recapitulates the selective stimulation of neuron terminals that occurs in vivo following release of target-derived neurotrophins. Retrograde signaling events that require long-range microtubule dependent retrograde transport have important implications for the treatment of neurodegenerative disorders.

  6. Therapeutic potential of the metabolic modulator phenformin in targeting the stem cell compartment in melanoma

    PubMed Central

    Albini, Adriana; Longo, Caterina; Argenziano, Giuseppe; Grisendi, Giulia; Dominici, Massimo; Ciarrocchi, Alessia; Dallaglio, Katiuscia

    2017-01-01

    Melanoma is the most dangerous and treatment-resistant skin cancer. Tumor resistance and recurrence are due to the persistence in the patient of aggressive cells with stem cell features, the cancer stem cells (CSC). Recent evidences have shown that CSC display a distinct metabolic profile as compared to tumor bulk population: a promising anti-tumor strategy is therefore to target specific metabolic pathways driving CSC behavior. Biguanides (metformin and phenformin) are anti-diabetic drugs able to perturb cellular metabolism and displaying anti-cancer activity. However, their ability to target the CSC compartment in melanoma is not known. Here we show that phenformin, but not metformin, strongly reduces melanoma cell viability, growth and invasion in both 2D and 3D (spheroids) models. While phenformin decreases melanoma CSC markers expression and the levels of the pro-survival factor MITF, MITF overexpression fails to prevent phenformin effects. Phenformin significantly reduces cell viability in melanoma by targeting both CSC (ALDHhigh) and non-CSC cells and by significantly reducing the number of viable cells in ALDHhigh and ALDHlow-derived spheroids. Consistently, phenformin reduces melanoma cell viability and growth independently from SOX2 levels. Our results show that phenformin is able to affect both CSC and non-CSC melanoma cell viability and growth and suggests its potential use as anti-cancer therapy in melanoma. PMID:28036292

  7. Characterization of MRP RNA-protein interactions within the perinucleolar compartment.

    PubMed

    Pollock, Callie; Daily, Kelly; Nguyen, Van Trung; Wang, Chen; Lewandowska, Marzena Anna; Bensaude, Olivier; Huang, Sui

    2011-03-15

    The perinucleolar compartment (PNC) forms in cancer cells and is highly enriched with a subset of polymerase III RNAs and RNA-binding proteins. Here we report that PNC components mitochondrial RNA-processing (MRP) RNA, pyrimidine tract-binding protein (PTB), and CUG-binding protein (CUGBP) interact in vivo, as demonstrated by coimmunoprecipitation and RNA pull-down experiments. Glycerol gradient analyses show that this complex is large and sediments at a different fraction from known MRP RNA-containing complexes, the MRP ribonucleoprotein ribozyme and human telomerase reverse transcriptase. Tethering PNC components to a LacO locus recruits other PNC components, further confirming the in vivo interactions. These interactions are present both in PNC-containing and -lacking cells. High-resolution localization analyses demonstrate that MRP RNA, CUGBP, and PTB colocalize at the PNC as a reticulated network, intertwining with newly synthesized RNA. Furthermore, green fluorescent protein (GFP)-PTB and GFP-CUGBP show a slower rate of fluorescence recovery after photobleaching at the PNC than in the nucleoplasm, illustrating the different molecular interaction of the complexes associated with the PNC. These findings support a working model in which the MRP RNA-protein complex becomes nucleated at the PNC in cancer cells and may play a role in gene expression regulation at the DNA locus that associates with the PNC.

  8. Recycling of proteins from the Golgi compartment to the ER in yeast

    PubMed Central

    1990-01-01

    In the yeast Saccharomyces cerevisiae, the carboxyl terminal sequence His-Asp-Glu-Leu (HDEL) has been shown to function as an ER retention sequence (Pelham, H. R. B., K. G. Hardwick, and M. J. Lewis. 1988. EMBO (Eur. Mol. Biol. Organ.) J. 7:1757-1762). To examine the mechanism of retention of soluble ER proteins in yeast, we have analyzed the expression of a preproalpha factor fusion protein, tagged at the carboxyl terminus with the HDEL sequence. We demonstrate that this fusion protein, expressed in vivo, accumulates intracellularly as a precursor containing both ER and Golgi-specific oligosaccharide modifications. The Golgi-specific carbohydrate modification, which occurs in a SEC18-dependent manner, consists of alpha 1-6 mannose linkages, with no detectable alpha 1-3 mannose additions, indicating that the transit of the HDEL-tagged fusion protein is confined to an early Golgi compartment. Results obtained from the fractionation of subcellular organelles from yeast expressing HDEL-tagged fusion proteins suggest that the Golgi-modified species are present in the ER. Overexpression of HDEL-tagged preproalpha factor results in the secretion of an endogenous HDEL-containing protein, demonstrating that the HDEL recognition system can be saturated. These results support the model in which the retention of these proteins in the ER is dependent on their receptor-mediated recycling from the Golgi complex back to the ER. PMID:2199456

  9. Minimum energy control for a two-compartment neuron to extracellular electric fields

    NASA Astrophysics Data System (ADS)

    Yi, Guo-Sheng; Wang, Jiang; Li, Hui-Yan; Wei, Xi-Le; Deng, Bin

    2016-11-01

    The energy optimization of extracellular electric field (EF) stimulus for a neuron is considered in this paper. We employ the optimal control theory to design a low energy EF input for a reduced two-compartment model. It works by driving the neuron to closely track a prescriptive spike train. A cost function is introduced to balance the contradictory objectives, i.e., tracking errors and EF stimulus energy. By using the calculus of variations, we transform the minimization of cost function to a six-dimensional two-point boundary value problem (BVP). Through solving the obtained BVP in the cases of three fundamental bifurcations, it is shown that the control method is able to provide an optimal EF stimulus of reduced energy for the neuron to effectively track a prescriptive spike train. Further, the feasibility of the adopted method is interpreted from the point of view of the biophysical basis of spike initiation. These investigations are conducive to designing stimulating dose for extracellular neural stimulation, which are also helpful to interpret the effects of extracellular field on neural activity.

  10. Time- and compartment-resolved proteome profiling of the extracellular niche in lung injury and repair

    PubMed Central

    Schiller, Herbert B; Fernandez, Isis E; Burgstaller, Gerald; Schaab, Christoph; Scheltema, Richard A; Schwarzmayr, Thomas; Strom, Tim M; Eickelberg, Oliver; Mann, Matthias

    2015-01-01

    The extracellular matrix (ECM) is a key regulator of tissue morphogenesis and repair. However, its composition and architecture are not well characterized. Here, we monitor remodeling of the extracellular niche in tissue repair in the bleomycin-induced lung injury mouse model. Mass spectrometry quantified 8,366 proteins from total tissue and bronchoalveolar lavage fluid (BALF) over the course of 8 weeks, surveying tissue composition from the onset of inflammation and fibrosis to its full recovery. Combined analysis of proteome, secretome, and transcriptome highlighted post-transcriptional events during tissue fibrogenesis and defined the composition of airway epithelial lining fluid. To comprehensively characterize the ECM, we developed a quantitative detergent solubility profiling (QDSP) method, which identified Emilin-2 and collagen-XXVIII as novel constituents of the provisional repair matrix. QDSP revealed which secreted proteins interact with the ECM, and showed drastically altered association of morphogens to the insoluble matrix upon injury. Thus, our proteomic systems biology study assigns proteins to tissue compartments and uncovers their dynamic regulation upon lung injury and repair, potentially contributing to the development of anti-fibrotic strategies. PMID:26174933

  11. The role of the cell wall compartment in mutualistic symbioses of plants

    PubMed Central

    Rich, Mélanie K.; Schorderet, Martine; Reinhardt, Didier

    2014-01-01

    Plants engage in mutualistic interactions with microbes that improve their mineral nutrient supply. The most wide-spread symbiotic association is arbuscular mycorrhiza (AM), in which fungi of the order Glomeromycota invade roots and colonize the cellular lumen of cortical cells. The establishment of this interaction requires a dedicated molecular-genetic program and a cellular machinery of the plant host. This program is partially shared with the root nodule symbiosis (RNS), which involves prokaryotic partners collectively referred to as rhizobia. Both, AM and RNS are endosymbioses that involve intracellular accommodation of the microbial partner in the cells of the plant host. Since plant cells are surrounded by sturdy cell walls, root penetration and cell invasion requires mechanisms to overcome this barrier while maintaining the cytoplasm of the two partners separate during development of the symbiotic association. Here, we discuss the diverse functions of the cell wall compartment in establishment and functioning of plant symbioses with the emphasis on AM and RNS, and we describe the stages of the AM association between the model organisms Petunia hybrida and Rhizophagus irregularis. PMID:24917869

  12. Compartment-specific transcriptomics in a reef-building coral exposed to elevated temperatures.

    PubMed

    Mayfield, Anderson B; Wang, Yu-Bin; Chen, Chii-Shiarng; Lin, Chung-Yen; Chen, Shu-Hwa

    2014-12-01

    Although rising ocean temperatures threaten scleractinian corals and the reefs they construct, certain reef corals can acclimate to elevated temperatures to which they are rarely exposed in situ. Specimens of the model Indo-Pacific reef coral Pocillopora damicornis collected from upwelling reefs of Southern Taiwan were previously found to have survived a 36-week exposure to 30°C, a temperature they encounter infrequently and one that can elicit the breakdown of the coral-dinoflagellate (genus Symbiodinium) endosymbiosis in many corals of the Pacific Ocean. To gain insight into the subcellular pathways utilized by both the coral hosts and their mutualistic Symbiodinium populations to acclimate to this temperature, mRNAs from both control (27°C) and high (30°C)-temperature samples were sequenced on an Illumina platform and assembled into a 236 435-contig transcriptome. These P. damicornis specimens were found to be ~60% anthozoan and 40% microbe (Symbiodinium, other eukaryotic microbes, and bacteria), from an mRNA-perspective. Furthermore, a significantly higher proportion of genes from the Symbiodinium compartment were differentially expressed after two weeks of exposure. Specifically, at elevated temperatures, Symbiodinium populations residing within the coral gastrodermal tissues were more likely to up-regulate the expression of genes encoding proteins involved in metabolism than their coral hosts. Collectively, these transcriptome-scale data suggest that the two members of this endosymbiosis have distinct strategies for acclimating to elevated temperatures that are expected to characterize many of Earth's coral reefs in the coming decades.

  13. Compartment syndrome in a patient treated with perineural liposomal bupivacaine (Exparel).

    PubMed

    Soberón, José Raul; Sisco-Wise, Leslie E; Dunbar, Ross M

    2016-06-01

    Acute compartment syndrome is a condition that may result in sensorimotor deficits and loss of function of the affected limb as a result of ischemic injury. It is considered a surgical emergency and prompt diagnosis and treatment results in more favorable outcomes. The use of regional anesthesia is controversial in patients at risk for compartment syndrome due to concern of its potential to mask symptoms of the condition. A 44-year-old African American male presented to surgery for open reduction and internal fixation of a comminuted distal radius fracture. As part of an off-label, investigator-initiated, and institutional review board-approved study, he received a perineural injection of liposomal bupivacaine (Exparel) around the median, ulnar, and radial nerves at the level of the proximal forearm. The following morning, his initial complaints of numbness and incisional pain progressively evolved into worsening numbness, diffuse discomfort, and pain with passive movement. A diagnosis of compartment syndrome was made and he underwent an emergency fasciotomy. The diagnosis of compartment syndrome requires a high index of suspicion and prompt treatment. This patient's changing pattern of symptoms-rather than his pain complaints alone-resulted in the diagnosis of compartment syndrome treated with emergent fasciotomy in spite of finger numbness that was initially attributed to the liposomal bupivacaine. While the use of liposomal bupivacaine did not preclude the diagnosis of compartment syndrome in our patient, it should be used with caution in patients at risk for compartment syndrome until additional data, particularly regarding block characteristics, are available.

  14. Geological CO2 sequestration in multi-compartment reservoirs: Geomechanical challenges

    NASA Astrophysics Data System (ADS)

    Castelletto, N.; Gambolati, G.; Teatini, P.

    2013-05-01

    Sequestration of large amounts of CO2 within deep underground reservoirs has been proposed as a potential approach for reducing atmospheric emissions of greenhouse gases. A CO2 sequestration project should address the associated environmental and safety issues and, in this respect, the importance of geomechanics has recently been widely recognized. Geomechanics is even more important when fluid injection is planned in faulted reservoirs. How much CO2 can be safely injected into multi-compartment reservoirs? Are geomechanical constraints more restrictive than flow-dynamic constraints? These and other questions are addressed in the present study using a three-dimensional finite element-interface element geomechanical model. We simulate the possible mechanical failure in both the injected formation and the caprock, the fault/thrust reactivation, and the ground surface displacement in a faulted reservoir of the offshore northern Italy, where seismic surveys provided an accurate characterization of the faulted geological structure. Based on reliable petrophysical/geomechanical properties from well logs and pore overpressure as predicted by a fluid-dynamic model, the results show that the injection of 1 × 106 ton/a of CO2 may be performed over a few years only. Thereafter, part of the injected formation fails by shear stress. A number of parametric scenarios are investigated to address the major uncertainties on the geomechanical response to CO2 injection. The modeling outcome suggests that shear failure and faults/thrusts reactivation can occur much before attaining the hydraulic fracturing pressure, hence representing two major constraints for a safe and permanent containment.

  15. Endocytosis of Epithelial Apical Junctional Proteins by a Clathrin-mediated Pathway into a Unique Storage Compartment

    PubMed Central

    Ivanov, Andrei I.; Nusrat, Asma; Parkos, Charles A.

    2004-01-01

    The adherens junction (AJ) and tight junction (TJ) are key regulators of epithelial polarity and barrier function. Loss of epithelial phenotype is accompanied by endocytosis of AJs and TJs via unknown mechanisms. Using a model of calcium depletion, we defined the pathway of internalization of AJ and TJ proteins (E-cadherin, p120 and β-catenins, occludin, JAM-1, claudins 1 and 4, and ZO-1) in T84 epithelial cells. Proteinase protection assay and immunocytochemistry revealed orchestrated internalization of AJs and TJs into a subapical cytoplasmic compartment. Disruption of caveolae/lipid rafts did not prevent endocytosis, nor did caveolin-1 colocalize with internalized junctional proteins. Furthermore, AJ and TJ proteins did not colocalize with the macropinocytosis marker dextran. Inhibitors of clathrin-mediated endocytosis blocked internalization of AJs and TJs, and junctional proteins colocalized with clathrin and α-adaptin. AJ and TJ proteins were observed to enter early endosomes followed by movement to organelles that stained with syntaxin-4 but not with markers of late and recycling endosomes, lysosomes, or Golgi. These results indicate that endocytosis of junctional proteins is a clathrin-mediated process leading into a unique storage compartment. Such mechanisms may mediate the disruption of intercellular contacts during normal tissue remodeling and in pathology. PMID:14528017

  16. A More Informed Evaluation of Medial Compartment Loading: the Combined Use of the Knee Adduction and Flexor Moments

    PubMed Central

    Manal, Kurt; Gardinier, Emily; Buchanan, Thomas S.; Snyder-Mackler, Lynn

    2015-01-01

    Objective To evaluate if the peak knee flexor moment provides unique and meaningful information about peak medial compartment loading above and beyond what is obtained from the peak knee adduction moment. Methods Standard video-based motion capture and EMG recordings were collected for 10 ACL reconstructed subjects walking at a self-selected speed. Knee joint moments were obtained using inverse dynamics and medial contact force was computed using an EMG-driven musculoskeletal model. Linear regression with the peak adductor moment entered first was implemented to isolate the unique contribution of the peak flexor moment to peak medial loading. Results Peak moments and medial contact force occurred during weight acceptance at approximately 23% of stance. The peak adduction moment (pKAM) was a significant predictor of peak medial loading (p = 0.004) accounting for approximately 63% of the variance. The peak knee flexor moment (pKFM) was also a significant predictor (p = 0.009) accounting for an additional 22% of the variance. When entered together pKAM and pKFM accounted for more than 85% of the variance in peak medial compartment loading. Conclusion The combined use of the peak knee flexor and adductor moments provides a significantly more accurate estimate of peak medial joint loading than the peak adduction moment alone. More accurate inferences of joint contact force will assist clinicians and researchers investigating relationships between joint loading and the onset and progression of knee OA. PMID:25862486

  17. FENS-1 and DFCP1 are FYVE domain-containing proteins with distinct functions in the endosomal and Golgi compartments.

    PubMed

    Ridley, S H; Ktistakis, N; Davidson, K; Anderson, K E; Manifava, M; Ellson, C D; Lipp, P; Bootman, M; Coadwell, J; Nazarian, A; Erdjument-Bromage, H; Tempst, P; Cooper, M A; Thuring, J W; Lim, Z Y; Holmes, A B; Stephens, L R; Hawkins, P T

    2001-11-01

    FENS-1 and DFCP1 are recently discovered proteins containing one or two FYVE-domains respectively. We show that the FYVE domains in these proteins can bind PtdIns3P in vitro with high specificity over other phosphoinositides. Exogenously expressed FENS-1 localises to early endosomes: this localisation requires an intact FYVE domain and is sensitive to wortmannin inhibition. The isolated FYVE domain of FENS-1 also localises to endosomes. These results are consistent with current models of FYVE-domain function in this cellular compartment. By contrast, exogenously expressed DFCP1 displays a predominantly Golgi, endoplasmic reticulum (ER) and vesicular distribution with little or no overlap with FENS-1 or other endosomal markers. Overexpression of DFCP1 was found to cause dispersal of the Golgi compartment defined by giantin and gpp130-staining. Disruption of the FYVE domains of DFCP1 causes a shift to more condensed and compact Golgi structures and overexpression of this mutant was found to confer significant protection to the Golgi against brefeldin-induced dispersal. These properties of DFCP1 are surprising, and suggest FYVE domain-localisation and function may not be exclusively endosomal. Movies available on-line

  18. Anatomical variations within the deep posterior compartment of the leg and important clinical consequences.

    PubMed

    Hislop, M; Tierney, P

    2004-09-01

    The management of musculoskeletal conditions makes up a large part of a sports medicine practitioner's practice. A thorough knowledge of anatomy is an essential component of the armament necessary to decipher the large number of potential conditions that may confront these practitioners. To cloud the issue further, anatomical variations may be present, such as supernumerary muscles, thickened fascial bands or variant courses of nerves and blood vessels, which can themselves manifest as acute or chronic conditions that lead to significant morbidity or limitation of activity. There are a number of contentious areas within the literature surrounding the anatomy of the leg, particularly involving the deep posterior compartment. Conditions such as chronic exertional compartment syndrome, tibial periostitis (shin splints), peripheral nerve entrapment and tarsal tunnel syndrome may all be affected by subtle anatomical variations. This paper primarily focuses on the deep posterior compartment of the leg and uses the gross dissection of cadaveric specimens to describe definitively the anatomy of the deep posterior compartment. Variant fascial attachments of flexor digitorum longus are documented and potential clinical sequelae such as chronic exertional compartment syndrome and tarsal tunnel syndrome are discussed.

  19. Treatment of compartment syndrome of the thigh associated with acute renal failure after the Wenchuan earthquake.

    PubMed

    Duan, Xin; Zhang, Kaiwei; Zhong, Gang; Cen, Shiqiang; Huang, Fuguo; Lv, Jingtong; Xiang, Zhou

    2012-04-01

    Compartment syndrome of the thigh is a rare emergency often treated operatively. The purpose of this study was to evaluate the effects of nonoperative treatment for compartment syndrome of the thigh associated with acute renal failure after the 2008 Wenchuan earthquake. Nonoperative treatment, which primarily involves continuous renal replacement therapy, was performed in 6 patients (3 men and 3 women) who presented with compartment syndrome of the thigh associated with acute renal failure. The mean mangled extremity severity score (MESS) and laboratory data regarding renal function were analyzed before and after treatment, and the clinical outcome was evaluated at 17-month follow-up. Laboratory data regarding renal function showed improvements. All 6 patients survived with the affected lower limbs intact after nonoperative treatment. Follow-up revealed active knee range of motion and increased muscle strength, as well as a recovery of sensation. A positive linear correlation was found between MESS and the time required to achieve a reduction in swelling, as well as the time required for the recovery of sensation and knee range of motion (r>0.8; P<.05). Satisfactory clinical outcomes were obtained in patients with compartment syndrome of the thigh associated with acute renal failure.Urine alkalization, electrolyte and water balance, and continuous renal replacement therapy have played an important role in saving lives and extremities. Nonoperative treatment should be considered in the treatment of compartment syndrome of the thigh associated with acute renal failure.

  20. A rare case of synovial chondromatosis of the inferior TMJ compartment. Diagnosis and treatment aspect

    PubMed Central

    Sozzi, Davide; Bocchialini, Gabriele; Novelli, Giorgio; Valente, Maria Gabriella; Moltrasio, Francesca; Bozzetti, Alberto

    2015-01-01

    Summary Aim Synovial Chondromatosis (SC) is a rare, benign non neoplastic arthopathy characterized by the metaplastic development of cartilaginous nodules within the synovial membrane. In only 3% of all cases does it affect the temporomandibular joint (TMJ) and cases that arise from the lower compartment are rarely found in literature. The aim of this paper is to report a new case of SC of the inferior TMJ compartment with the description of the clinical, therapeutic and histopathological findings. Case report This article presents a 68-year-old woman with preauricular swelling on the right side, pain, crepitus and limited joint motion. This patient was evaluated by preoperative clinical manifestation, CT scan and MR images. Both showed multiple, calcified loose bodies in the inferior compartment. Based on these images as well as the patient’s signs and symptoms, a surgical intervention was performed. A good functional recovery with no signs of recurrence at 36 months of follow up was obtained. Conclusion Among cases of synovial chondromatosis in literature, only twelve originating in the lower compartment have been reported, this one included. In all the cases treated for SC in the lower compartment, both in literature and in our case report, surgical treatment led to healing. PMID:26941895