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Sample records for volume change induced

  1. Volume changes in glass induced by an electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Gavenda, Tadeáš, E-mail: gavendat@vscht.cz [Department of Glass and Ceramics, Institute of Chemical Technology, Technická 5, CZ-166 28 Prague (Czech Republic); Gedeon, Ondrej [Department of Glass and Ceramics, Institute of Chemical Technology, Technická 5, CZ-166 28 Prague (Czech Republic); Jurek, Karel [Institute of Physics, Academy of the Czech Republic, Na Slovance 2, CZ-182 21 Prague (Czech Republic)

    2014-03-01

    Three glasses (float, borosilicate float and Schott D263 glasses) were irradiated by 50 keV electron beams with doses within the range of 0.21–318.5 kC/m{sup 2}. Volume changes induced by electron bombarding were monitored by means of Atomic Force Microscopy. Incubation doses, related to mobility of alkali ions, were measured. Low doses showed compaction of all glasses while higher doses revealed volume inflation, except for borosilicate float glass. Both surfaces of float glass were irradiated and significant differences between them were found.

  2. Volume changes in glass induced by an electron beam

    Science.gov (United States)

    Gavenda, Tadeáš; Gedeon, Ondrej; Jurek, Karel

    2014-03-01

    Three glasses (float, borosilicate float and Schott D263 glasses) were irradiated by 50 keV electron beams with doses within the range of 0.21-318.5 kC/m2. Volume changes induced by electron bombarding were monitored by means of Atomic Force Microscopy. Incubation doses, related to mobility of alkali ions, were measured. Low doses showed compaction of all glasses while higher doses revealed volume inflation, except for borosilicate float glass. Both surfaces of float glass were irradiated and significant differences between them were found.

  3. Changes in Stroke Volume Induced by Lung Recruitment Maneuver Predict Fluid Responsiveness in Mechanically Ventilated Patients in the Operating Room.

    Science.gov (United States)

    Biais, Matthieu; Lanchon, Romain; Sesay, Musa; Le Gall, Lisa; Pereira, Bruno; Futier, Emmanuel; Nouette-Gaulain, Karine

    2017-02-01

    Lung recruitment maneuver induces a decrease in stroke volume, which is more pronounced in hypovolemic patients. The authors hypothesized that the magnitude of stroke volume reduction through lung recruitment maneuver could predict preload responsiveness. Twenty-eight mechanically ventilated patients with low tidal volume during general anesthesia were included. Heart rate, mean arterial pressure, stroke volume, and pulse pressure variations were recorded before lung recruitment maneuver (application of continuous positive airway pressure of 30 cm H2O for 30 s), during lung recruitment maneuver when stroke volume reached its minimal value, and before and after volume expansion (250 ml saline, 0.9%, infused during 10 min). Patients were considered as responders to fluid administration if stroke volume increased greater than or equal to 10%. Sixteen patients were responders. Lung recruitment maneuver induced a significant decrease in mean arterial pressure and stroke volume in both responders and nonresponders. Changes in stroke volume induced by lung recruitment maneuver were correlated with those induced by volume expansion (r = 0.56; P recruitment maneuver predicted fluid responsiveness with a sensitivity of 88% (95% CI, 62 to 98) and a specificity of 92% (95% CI, 62 to 99). Pulse pressure variations more than 6% before lung recruitment maneuver discriminated responders with a sensitivity of 69% (95% CI, 41 to 89) and a specificity of 75% (95% CI, 42 to 95). The area under receiver operating curves generated for changes in stroke volume induced by lung recruitment maneuver (0.96; 95% CI, 0.81 to 0.99) was significantly higher than that for pulse pressure variations (0.72; 95% CI, 0.52 to 0.88; P recruitment maneuver could predict preload responsiveness in mechanically ventilated patients in the operating room.

  4. Resistance exercise-induced fluid shifts: change in active muscle size and plasma volume

    Science.gov (United States)

    Ploutz-Snyder, L. L.; Convertino, V. A.; Dudley, G. A.

    1995-01-01

    The purpose of this study was to test the hypothesis that the reduction in plasma volume (PV) induced by resistance exercise reflects fluid loss to the extravascular space and subsequently selective increase in cross-sectional area (CSA) of active but not inactive skeletal muscle. We compared changes in active and inactive muscle CSA and PV after barbell squat exercise. Magnetic resonance imaging (MRI) was used to quantify muscle involvement in exercise and to determine CSA of muscle groups or individual muscles [vasti (VS), adductor (Add), hamstring (Ham), and rectus femoris (RF)]. Muscle involvement in exercise was determined using exercise-induced contrast shift in spin-spin relaxation time (T2)-weighted MR images immediately postexercise. Alterations in muscle size were based on the mean CSA of individual slices. Hematocrit, hemoglobin, and Evans blue dye were used to estimate changes in PV. Muscle CSA and PV data were obtained preexercise and immediately postexercise and 15 and 45 min thereafter. A hierarchy of muscle involvement in exercise was found such that VS > Add > Ham > RF, with the Ham and RF showing essentially no involvement. CSA of the VS and Add muscle groups were increased 10 and 5%, respectively, immediately after exercise in each thigh with no changes in Ham and RF CSA. PV was decreased 22% immediately following exercise. The absolute loss of PV was correlated (r2 = 0.75) with absolute increase in muscle CSA immediately postexercise, supporting the notion that increased muscle size after resistance exercise reflects primarily fluid movement from the vascular space into active but not inactive muscle.

  5. Radiation-induced changes of brain tissue after radiosurgery in patients with arteriovenous malformations: dose/volume-response relations

    Energy Technology Data Exchange (ETDEWEB)

    Levegruen, S.; Schlegel, W. [Dept. of Medical Physics, German Cancer Research Center (DKFZ), Heidelberg (Germany); Hof, H.; Debus, J. [Dept. of Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg (Germany); Essig, M. [Dept. of Radiology, German Cancer Research Center (DKFZ), Heidelberg (Germany)

    2004-12-01

    Purpose: to evaluate late radiation effects in the brain after radiosurgery of patients with cerebral arteriovenous malformations (AVMs) and to quantify dose/volume-response relations for radiation-induced changes of brain tissue identified on follow-up neuroimaging. Patients and methods: data from 73 AVM patients who had stereotactic linac radiosurgery at DKFZ (German Cancer Research Center), Heidelberg, Germany, were retrospectively analyzed. The endpoint of radiation-induced changes of brain tissue on follow-up magnetic resonance (MR) neuroimaging (i.e., edema and blood-brain-barrier breakdown [BBBB]) was evaluated. Each endpoint was further differentiated into three levels with respect to the extent of the image change (small, intermediate, and large). A previous analysis of the data found correlation of the endpoints with several dose/volume variables (DV) derived from each patient's dose distribution in the brain, including the mean dose in a volume of 20 cm{sup 3} (Dmean20) and the absolute brain volume (including the AVM target) receiving a dose of at least 12 Gy (V12). To quantify dose/volume-response relations, patients were ranked according to DV (i.e., Dmean20 and V12) and classified into four groups of equal size. For each group, the actuarial rates of developing the considered endpoints within 2.5 years after radiosurgery were determined from Kaplan-Meier estimates. The dose/volume-response curves were fitted with a sigmoid-shape logistic function and characterized by DV{sub 50}, the dose for a 50% incidence, and the slope parameter k. Results: dose/volume-response relations, based on two alternative, but correlated, dose distribution variables that are a function of both dose and volume, were observed for radiation-induced changes of brain tissue. DV{sub 50} values of fitted dose/volume-response curves for tissue changes of large extent (e.g., V12{sub 50} = 22.0 {+-} 2.6 cm{sup 3} and Dmean20{sub 50} = 17.8 {+-} 2.0 Gy for the combined endpoint

  6. Plasma volume changes during hypoglycaemia

    DEFF Research Database (Denmark)

    Hilsted, J; Frandsen, Henrik Lund; Christensen, N J

    1991-01-01

    -induced hypoglycaemia with total autonomic blockade (alpha-adrenoceptor blockade combined with beta-adrenoceptor blockade and atropine); and insulin-induced hypoglycaemia without any autonomic blockade. In the experiments without autonomic blockade the peripheral venous hematocrit increased, plasma volume decreased......, intravascular albumin content decreased and the transcapillary escape rate of albumin increased. In both experiments with autonomic blockade the increase in venous haematocrit was abolished, yet plasma volume decreased, intravascular albumin content decreased and the transcapillary escape rate of albumin...... increased in these experiments. Thus, the changes in plasma volume and composition in response to hypoglycaemia are due to the combined actions of adrenaline and of insulin....

  7. Plasma volume changes during hypoglycaemia

    DEFF Research Database (Denmark)

    Hilsted, J; Bendtsen, F; Christensen, N J

    1990-01-01

    To investigate whether previously reported changes in venous blood volume and composition induced by acute hypoglycaemia in humans are representative for the entire body we measured erythrocyte 51Cr content, haematocrit, plasma volume, intravascular albumin content and transcapillary escape rate...... of albumin in arterial and venous blood in seven healthy subjects before and during insulin-induced hypoglycaemia. In both vascular sites blood 51Cr content and the haematocrit increased, plasma volume and intravascular albumin content decreased and the transcapillary escape rate of albumin increased during...

  8. Modulation of cadmium-induced mitochondrial dysfunction and volume changes by temperature in rainbow trout (Oncorhynchus mykiss)

    Energy Technology Data Exchange (ETDEWEB)

    Onukwufor, John O. [Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada C1A 4P3 (Canada); Kibenge, Fred [Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada C1A 4P3 (Canada); Stevens, Don [Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada C1A 4P3 (Canada); Kamunde, Collins, E-mail: ckamunde@upei.ca [Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada C1A 4P3 (Canada)

    2015-01-15

    Highlights: • Interactions of Cd and temperature exacerbate mitochondrial dysfunction and enhance Cd accumulation. • Cd uptake by mitochondria occurs through the Ca uniporter. • Temperature exacerbates Cd-induced mitochondrial volume changes. • Low concentrations of Cd inhibit mitochondrial swelling. - Abstract: We investigated how temperature modulates cadmium (Cd)-induced mitochondrial bioenergetic disturbances, metal accumulation and volume changes in rainbow trout (Oncorhynchus mykiss). In the first set of experiments, rainbow trout liver mitochondrial function and Cd content were measured in the presence of complex I substrates, malate and glutamate, following exposure to Cd (0–100 μM) at three (5, 13 and 25 °C) temperatures. The second set of experiments assessed the effect of temperature on Cd-induced mitochondrial volume changes, including the underlying mechanisms, at 15 and 25 °C. Although temperature stimulated both state 3 and 4 rates of respiration, the coupling efficiency was reduced at temperature extremes due to greater inhibition of state 3 at low temperature and greater stimulation of state 4 at the high temperature. Cadmium exposure reduced the stimulatory effect of temperature on state 3 respiration but increased that on state 4, consequently exacerbating mitochondrial uncoupling. The interaction of Cd and temperature yielded different responses on thermal sensitivity of state 3 and 4 respiration; the Q{sub 10} values for state 3 respiration increased at low temperature (5–13 °C) while those for state 4 increased at high temperature (13–25 °C). Importantly, the mitochondria accumulated more Cd at high temperature suggesting that the observed greater impairment of oxidative phosphorylation with temperature was due, at least in part, to a higher metal burden. Cadmium-induced mitochondrial volume changes were characterized by an early phase of contraction followed by swelling, with temperature changing the kinetics and

  9. Variations in gastric compliance induced by acute blood volume changes in anesthetized rats

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    Graça J.R.V.

    2002-01-01

    Full Text Available The impact of acute volume imbalances on gastric volume (GV was studied in anesthetized rats (250-300 g. After cervical and femoral vessel cannulation, a balloon catheter was positioned in the proximal stomach. The opposite end of the catheter was connected to a barostat with an electronic sensor coupled to a plethysmometer. A standard ionic solution was used to fill the balloon (about 3.0 ml and the communicating vessel system, and to raise the reservoir liquid level 4 cm above the animals' xiphoid appendix. Due to constant barostat pressure, GV values were considered to represent the gastric compliance index. All animals were monitored for 90 min. After a basal interval, they were randomly assigned to normovolemic, hypervolemic, hypovolemic or restored protocols. Data were compared by ANOVA followed by Bonferroni's test. Mean arterial pressure (MAP, central venous pressure (CVP and GV values did not change in normovolemic animals (N = 5. Hypervolemic animals (N = 12 were transfused at 0.5 ml/min with a suspension of red blood cells in Ringer-lactate solution with albumin (12.5 ml/kg, which reduced GV values by 11.3% (P0.05. MAP and CVP values increased (P<0.05 after hypervolemia but decreased (P<0.05 with hypovolemia. In conclusion, blood volume level modulates gastric compliance, turning the stomach into an adjustable reservoir, which could be part of the homeostatic process to balance blood volume.

  10. A new microscopic method to analyse desiccation-induced volume changes in aeroterrestrial green algae.

    Science.gov (United States)

    Lajos, K; Mayr, S; Buchner, O; Blaas, K; Holzinger, A

    2016-08-01

    Aeroterrestrial green algae are exposed to desiccation in their natural habitat, but their actual volume changes have not been investigated. Here, we measure the relative volume reduction (RVRED ) in Klebsormidium crenulatum and Zygnema sp. under different preset relative air humidities (RH). A new chamber allows monitoring RH during light microscopic observation of the desiccation process. The RHs were set in the range of ∼4 % to ∼95% in 10 steps. RVRED caused by the desiccation process was determined after full acclimation to the respective RHs. In K. crenulatum, RVRED (mean ± SE) was 46.4 ± 1.9%, in Zygnema sp. RVRED was only 34.3 ± 2.4% at the highest RH (∼95%) tested. This indicates a more pronounced water loss at higher RHs in K. crenulatum versus Zygnema sp. By contrast, at the lowest RH (∼4%) tested, RVRED ranged from 75.9 ± 2.7% in K. crenulatum to 83.9 ± 2.2% in Zygnema sp. The final volume reduction is therefore more drastic in Zygnema sp. These data contribute to our understanding of the desiccation process in streptophytic green algae, which are considered the closest ancestors of land plants.

  11. Arterial pressure allows monitoring the changes in cardiac output induced by volume expansion but not by norepinephrine.

    Science.gov (United States)

    Monnet, Xavier; Letierce, Alexia; Hamzaoui, Olfa; Chemla, Denis; Anguel, Nadia; Osman, David; Richard, Christian; Teboul, Jean-Louis

    2011-06-01

    To evaluate to which extent the systemic arterial pulse pressure could be used as a surrogate of cardiac output for assessing the effects of a fluid challenge and of norepinephrine. Observational study. Medical intensive care unit. Patients with an acute circulatory failure who received a fluid challenge (228 patients, group 1) or in whom norepinephrine was introduced or increased (145 patients, group 2). We measured the systolic, diastolic, and mean arterial pressure, pulse pressure, and the transpulmonary thermodilution cardiac output before and after the therapeutic interventions. In group 1, the fluid challenge significantly increased cardiac output by 24% ± 25%. It significantly increased cardiac output by ≥15% (+35% ± 27%) in 142 patients ("responders"). The fluid-induced changes in cardiac output were correlated with the changes in pulse pressure (r = .56, p arterial pressure (r = .55, p arterial pressure (r = .37, p arterial pressure (r = .52, p pressure were significantly related to changes in stroke volume (multiple r = .52) and to age (r = .12). A fluid-induced increase in pulse pressure of ≥17% allowed detecting a fluid-induced increase in cardiac output of ≥15% with a sensitivity of 65[56-72]% and a specificity of 85[76-92]%. The area under the receiver operating characteristic curves for the fluid-induced changes in mean arterial pressure and in diastolic arterial pressure was significantly lower than for pulse pressure. In group 2, the introduction/increase of norepinephrine significantly increased cardiac output by 14% ± 18%. The changes in cardiac output induced by the introduction/increase in the dose of norepinephrine were correlated with the changes in pulse pressure and systolic arterial pressure (r = .21 and .29, respectively, p = .001) but to a significantly lesser extent than in group 1. Pulse pressure and systolic arterial pressure could be used for detecting the fluid-induced changes in cardiac output, in spite of a significant

  12. A longitudinal study of stress-induced hippocampal volume changes in mice that are susceptible or resilient to chronic social defeat.

    Science.gov (United States)

    Tse, Yiu Chung; Montoya, Ixchel; Wong, Alice S; Mathieu, Axel; Lissemore, Jennifer; Lagace, Diane C; Wong, Tak Pan

    2014-09-01

    Hippocampal shrinkage is a commonly found neuroanatomical change in stress-related mood disorders such as depression and post-traumatic stress disorders (PTSD). Since the onset and severity of these disorders have been found to be closely related to stressful life events, and as stress alone has been shown to reduce hippocampal volume in animal studies, vulnerability to mood disorders may be related to a susceptibility to stress-induced hippocampal shrinkage. However, a smaller hippocampal volume before stress exposure has also been suggested to confer vulnerability of stressed individuals to PTSD or depression. In this study, we examined the contribution of either innate hippocampal volume differences or hippocampal susceptibility to stress-induced shrinkage to the formation of stress-related psychopathology using longitudinal MRI measurements of hippocampal volume in inbred C57 mice before and after chronic social defeat stress. We found that only half of the stressed C57 mice were susceptible to stress and developed psychopathological behaviors such as social avoidance. The other half was resilient to stress and exhibited no social avoidance. Before exposure to stress, we observed a positive correlation between hippocampal volume and social avoidance. After chronic social defeat stress, we found significant increases in left hippocampal volume in resilient and nonstressed control mice. Intriguingly, this increase in hippocampal volume was not found in susceptible mice, suggesting an arrestment of hippocampal growth in these mice. Our findings suggest that both a susceptibility to stress-induced hippocampal volume changes and a larger hippocampus before stress exposure confer vulnerability to psychopathology after chronic stress. © 2014 Wiley Periodicals, Inc.

  13. Biochemical kinetics in changing volumes.

    Science.gov (United States)

    Pawłowski, Piotr H; Zielenkiewicz, Piotr

    2004-01-01

    The need of taking into account the change of compartment volume when developing chemical kinetics analysis inside the living cell is discussed. Literature models of a single enzymatic Michaelis-Menten process, glycolytic oscillations, and mitotic cyclin oscillations were tested with appropriate theoretical extension in the direction of volume modification allowance. Linear and exponential type of volume increase regimes were compared. Due to the above, in a growing cell damping of the amplitude, phase shift, and time pattern deformation of the metabolic rhythms considered were detected, depending on the volume change character. The performed computer simulations allow us to conclude that evolution of the cell volume can be an essential factor of the chemical kinetics in a growing cell. The phenomenon of additional metabolite oscillations caused by the periodic cell growth and division was theoretically predicted and mathematically described. Also, the hypothesis of the periodized state in the growing cell as the generalization of the steady-state was formulated.

  14. Changes in Myocardial Composition and Conduction Properties in Rat Heart Failure Model Induced by Chronic Volume Overload

    Directory of Open Access Journals (Sweden)

    David Sedmera

    2016-08-01

    Full Text Available Volume overload leads to development of eccentric cardiac hypertrophy and heart failure. In our previous report, we have shown myocyte hypertrophy with no fibrosis and decrease in gap junctional coupling via connexin43 in a rat model of aorto-caval fistula at 21 weeks. Here we set to analyze the electrophysiological and protein expression changes in the left ventricle and correlate them with phenotypic severity based upon ventricles to body weight ratio.ECG analysis showed increased amplitude and duration of the P wave, prolongation of PR and QRS interval, ST segment elevation and decreased T wave amplitude in the fistula group. Optical mapping showed a prolongation of action potential duration in the hypertrophied hearts. Minimal conduction velocity (CV showed a bell-shaped curve, with a significant increase in the mild cases and there was a negative correlation of both minimal and maximal CV with heart to body weight ratio. Since the CV is influenced by gap junctional coupling as well as the autonomic nervous system, we measured the amounts of tyrosine hydroxylase (TH and choline acetyl transferase (ChAT as a proxy for sympathetic and parasympathetic innervation, respectively. At the protein level, we confirmed a significant decrease in total and phosphorylated connexin43 that was proportional to the level of hypertrophy, and similarly decreased levels of TH and ChAT.Even at a single time-point, severity of morphological phenotype correlates with progression of molecular and electrophysiological changes, with the most hypertrophied hearts showing the most severe changes that might be related to arrhythmogenesis.

  15. Parallel Changes in Intracellular Water Volume and pH Induced by NH3/NH4+ Exposure in Single Neuroblastoma Cells

    Directory of Open Access Journals (Sweden)

    Víctor M. Blanco

    2013-12-01

    Full Text Available Background: Increased blood levels of ammonia (NH3 and ammonium (NH4+, i.e. hyperammonemia, leads to cellular brain edema in humans with acute liver failure. The pathophysiology of this edema is poorly understood. This is partly due to incomplete understanding of the osmotic effects of the pair NH3/NH4+ at the cellular and molecular levels. Cell exposure to solutions containing NH3/NH4+ elicits changes in intracellular pH (pHi, which can in turn affect cell water volume (CWV by activating transport mechanisms that produce net gain or loss of solutes and water. The occurrence of CWV changes caused by NH3/NH4+ has long been suspected, but the mechanisms, magnitude and kinetics of these changes remain unknown. Methods: Using fluorescence imaging microscopy we measured, in real time, parallel changes in pHi and CWV caused by brief exposure to NH3/NH4+ of single cells (N1E-115 neuroblastoma or NG-108 neuroblastoma X glioma loaded with the fluorescent indicator BCECF. Changes in CWV were measured by exciting BCECF at its intracellular isosbestic wavelength (∼438 nm, and pHi was measured ratiometrically. Results: Brief exposure to isosmotic solutions (i.e. having the same osmolality as that of control solutions containing NH4Cl (0.5- 30 mM resulted in a rapid, dose-dependent swelling, followed by isosmotic regulatory volume decrease (iRVD. NH4Cl solutions in which either extracellular [NH3] or [NH4+] was kept constant while the other was changed by varying the pH of the solution, demonstrated that [NH3]o rather than [NH4+]o is the main determinant of the NH4Cl-induced swelling. The iRVD response was sensitive to the anion channel blocker NPPB, and partly dependent on external Ca2+. Upon removal of NH4Cl, cells shrank and displayed isosmotic regulatory volume increase (iRVI. Regulatory volume responses could not be activated by comparable CWV changes produced by anisosmotic solutions, suggesting that membrane stretch or contraction by themselves are

  16. Shear-induced Volume Decrease in MDCK Cells

    Science.gov (United States)

    Heo, Jinseok; Sachs, Frederick; Wang, Jianbin; Hua, Susan Z.

    2013-01-01

    Using a microfluidic cell volume sensor we measured the change in the cell volume of Madin-Darby Canine Kidney (MDCK) cells induced by shear stress. An increase in shear stress from 0.2 to 2.0 dyn/cm2 resulted in a volume decrease to a steady state volume ~ 20 – 30 % smaller than the initial resting cell volume. Independent experiments based on fluorescence quenching confirmed the volume reduction. This shear-induced cell shrinkage was irreversible on the time scale of the experiment (~ 30 min). Treatment of 0.1 μM Hg2+ significantly inhibited the volume decrease, suggesting that the shear-induced cell shrinkage is associated with water efflux through aquaporins. The volume decrease cannot be inhibited by 75 mM TEA, 100 μM DIDS, or 100 μM Gd3+ suggesting that volume reduction is not directly mediated by K+ and Cl− channels that typically function during regulatory volume decrease (RVD), nor is it through cationic stretch-activated ion channels (SACs). The process also appears to be Ca2+ independent because it was insensitive to intracellular Ca2+ level. Since cell volume is determined by the intracellular water content, we postulate that the shear induced reductions in cell volume may arise from increased intracellular hydrostatic pressure as the cell is deformed under flow, which promotes the efflux of water. The increase in internal pressure in a deformable object under the flow is supported by the finite element mechanical model. PMID:22759987

  17. Change in volume parameters induced by neoadjuvant chemotherapy provide accurate prediction of overall survival after resection in patients with oesophageal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Tamandl, Dietmar; Fueger, Barbara; Kinsperger, Patrick; Haug, Alexander; Ba-Ssalamah, Ahmed [Medical University of Vienna, Department of Biomedical Imaging and Image-Guided Therapy, Comprehensive Cancer Center GET-Unit, Vienna (Austria); Gore, Richard M. [University of Chicago Pritzker School of Medicine, Department of Radiology, Chicago, IL (United States); Hejna, Michael [Medical University of Vienna, Department of Internal Medicine, Division of Medical Oncology, Comprehensive Cancer Center GET-Unit, Vienna (Austria); Paireder, Matthias; Schoppmann, Sebastian F. [Medical University of Vienna, Department of Surgery, Upper-GI-Service, Comprehensive Cancer Center GET-Unit, Vienna (Austria)

    2016-02-15

    To assess the prognostic value of volumetric parameters measured with CT and PET/CT in patients with neoadjuvant chemotherapy (NACT) and resection for oesophageal cancer (EC). Patients with locally advanced EC, who were treated with NACT and resection, were retrospectively analysed. Data from CT volumetry and {sup 18} F-FDG PET/CT (maximum standardized uptake [SUVmax], metabolic tumour volume [MTV], and total lesion glycolysis [TLG]) were recorded before and after NACT. The impact of volumetric parameter changes induced by NACT (MTV{sub RATIO}, TLG{sub RATIO}, etc.) on overall survival (OS) was assessed using a Cox proportional hazards model. Eighty-four patients were assessed using CT volumetry; of those, 50 also had PET/CT before and after NACT. Low post-treatment CT volume and thickness, MTV, TLG, and SUVmax were all associated with longer OS (p < 0.05), as were CTthickness{sub RATIO}, MTV{sub RATIO}, TLG{sub RATIO}, and SUVmax{sub RATIO} (p < 0.05). In the multivariate analysis, only MTV{sub RATIO} (Hazard ratio, HR 2.52 [95 % Confidence interval, CI 1.33-4.78], p = 0.005), TLG{sub RATIO} (HR 3.89 [95%CI 1.46-10.34], p = 0.006), and surgical margin status (p < 0.05), were independent predictors of OS. MTV{sub RATIO} and TLG{sub RATIO} are independent prognostic factors for survival in patients after NACT and resection for EC. (orig.)

  18. Do intravascular hypo- and hypervolaemia result in changes in central blood volumes?

    NARCIS (Netherlands)

    Vos, J. J.; Scheeren, T. W. L.; Loer, S. A.; Hoeft, A.; Wietasch, J. K. G.

    2016-01-01

    Background: Hypovolaemia is generally believed to induce centralization of blood volume. Therefore, we evaluated whether induced hypo-and hypervolaemia result in changes in central blood volumes (pulmonary blood volume (PBV), intrathoracic blood volume (ITBV)) and we explored the effects on the dist

  19. Changes in the electro-physical properties of MCT epitaxial films affected by a plasma volume discharge induced by an avalanche beam in atmospheric-pressure air

    Science.gov (United States)

    Grigoryev, D. V.; Voitsekhovskii, A. V.; Lozovoy, K. A.; Tarasenko, V. F.; Shulepov, M. A.

    2015-11-01

    In this paper the influence of the plasma volume discharge of nanosecond duration formed in a non-uniform electric field at atmospheric pressure on samples of epitaxial films HgCdTe (MCT) films are discussed. The experimental data show that the action of pulses of nanosecond volume discharge in air at atmospheric pressure leads to changes in the electrophysical properties of MCT epitaxial films due to formation of a near-surface high- conductivity layer of the n-type conduction. The preliminary results show that it is possible to use such actions in the development of technologies for the controlled change of the properties of MCT.

  20. Volume change of Al/sub 2/O/sub 3/ and MgAl/sub 2/O/sub 4/ induced by 14-MeV neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Tanimura, Katsumi; Itoh, Noriaki; Clinard, F.W.

    1987-10-01

    Volume change of Al/sub 2/O/sub 3/ and MgAl/sub 2/O/sub 4/ induced by irradiation with 14-MeV neutrons at 50/sup 0/C has been measured. It is shown that the volume change of Al/sub 2/O/sub 3/ is anisotropic and is larger than that of MgAl/sub 2/O/sub 4/ about a factor of five. The result for MgAl/sub 2/O/sub 4/ is compared with that of fission neutron irradiation.

  1. Quantifying Volume Changing Perturbations in a Wave Chaotic System

    CERN Document Server

    Taddese, Biniyam Tesfaye; Moglie, Franco; Antonsen, Thomas M; Ott, Edward; Anlage, Steven M

    2012-01-01

    A sensor was developed to quantitatively measure perturbations which change the volume of a wave chaotic cavity while leaving its shape intact. The sensors work in the time domain by using either scattering fidelity of the transmitted signals or the classical analog of the Loschmidt echo. The sensors were tested experimentally by inducing volume changing perturbations to a one cubic meter pseudo-integrable, real-world cavity. Perturbations which caused a volume change that is as small as 54 parts in a million were quantitatively measured. These results were obtained by using electromagnetic waves with a wavelength of about $5cm$, therefore, the sensor is sensitive to extreme sub-wavelength changes of the boundaries of a cavity. The experimental results were compared with Finite Difference Time Domain (FDTD) simulation results, and good agreement was found. Furthermore, the sensor was tested using a frequency domain approach on a numerical model of the star graph, which is a representative wave chaotic system....

  2. Induction of Inducible Nitric Oxide Synthase by Lipopolysaccharide and the Influences of Cell Volume Changes, Stress Hormones and Oxidative Stress on Nitric Oxide Efflux from the Perfused Liver of Air-Breathing Catfish, Heteropneustes fossilis.

    Science.gov (United States)

    Choudhury, Mahua G; Saha, Nirmalendu

    2016-01-01

    The air-breathing singhi catfish (Heteropneustes fossilis) is frequently being challenged by bacterial contaminants, and different environmental insults like osmotic, hyper-ammonia, dehydration and oxidative stresses in its natural habitats throughout the year. The main objectives of the present investigation were to determine (a) the possible induction of inducible nitric oxide synthase (iNOS) gene with enhanced production of nitric oxide (NO) by intra-peritoneal injection of lipopolysaccharide (LPS) (a bacterial endotoxin), and (b) to determine the effects of hepatic cell volume changes due to anisotonicity or by infusion of certain metabolites, stress hormones and by induction of oxidative stress on production of NO from the iNOS-induced perfused liver of singhi catfish. Intra-peritoneal injection of LPS led to induction of iNOS gene and localized tissue specific expression of iNOS enzyme with more production and accumulation of NO in different tissues of singhi catfish. Further, changes of hydration status/cell volume, caused either by anisotonicity or by infusion of certain metabolites such as glutamine plus glycine and adenosine, affected the NO production from the perfused liver of iNOS-induced singhi catfish. In general, increase of hydration status/cell swelling due to hypotonicity caused decrease, and decrease of hydration status/cell shrinkage due to hypertonicity caused increase of NO efflux from the perfused liver, thus suggesting that changes in hydration status/cell volume of hepatic cells serve as a potent modulator for regulating the NO production. Significant increase of NO efflux from the perfused liver was also observed while infusing the liver with stress hormones like epinephrine and norepinephrine, accompanied with decrease of hydration status/cell volume of hepatic cells. Further, oxidative stress, caused due to infusion of t-butyl hydroperoxide and hydrogen peroxide separately, in the perfused liver of singhi catfish, resulted in

  3. Airway surface liquid volume expansion induces rapid changes in amiloride-sensitive Na+ transport across upper airway epithelium-Implications concerning the resolution of pulmonary edema

    Science.gov (United States)

    Azizi, Fouad; Arredouani, Abdelilah; Mohammad, Ramzi M

    2015-01-01

    During airway inflammation, airway surface liquid volume (ASLV) expansion may result from the movement of plasma proteins and excess liquid into the airway lumen due to extravasation and elevation of subepithelial hydrostatic pressure. We previously demonstrated that elevation of submucosal hydrostatic pressure increases airway epithelium permeability resulting in ASLV expansion by 500 μL cm−2 h−1. Liquid reabsorption by healthy airway epithelium is regulated by active Na+ transport at a rate of 5 μL cm−2 h−1. Thus, during inflammation the airway epithelium may be submerged by a large volume of luminal liquid. Here, we have investigated the mechanism by which ASLV expansion alters active epithelial Na+ transport, and we have characterized the time course of the change. We used primary cultures of tracheal airway epithelium maintained under air interface (basal ASLV, depth is 7 ± 0.5 μm). To mimic airway flooding, ASLV was expanded to a depth of 5 mm. On switching from basal to expanded ASLV conditions, short-circuit current (Isc, a measure of total transepithelial active ion transport) declined by 90% with a half-time (t1/2) of 1 h. 24 h after the switch, there was no significant change in ATP concentration nor in the number of functional sodium pumps as revealed by [3H]-ouabain binding. However, amiloride-sensitive uptake of 22Na+ was reduced by 70% upon ASLV expansion. This process is reversible since after returning cells back to air interface, Isc recovered with a t1/2 of 5–10 h. These results may have important clinical implications concerning the development of Na+ channels activators and resolution of pulmonary edema. PMID:26333829

  4. Apparatus for determining changes in limb volume

    Science.gov (United States)

    Bhagat, P. K.; Wu, V. C. (Inventor)

    1981-01-01

    Measuring apparatus for determining changes in the volume of limbs or other boty extremities by determining the cross-sectional area of such limbs many comprise a transmitter including first and second transducers for positioning on the surface of the limb at a predetermined distance there between, and a receiver including a receiver crystal for positioning on the surface of the limb. The distance between the receiver crystal and the first and second transducers are represented by respective first and second chords of the cross-section of the limb and the predetermined distance between the first and second transducers is represented by a third chord of the limb cross section.

  5. Disproportional changes in hematocrit, plasma volume, and proteins during exercise and bed rest.

    Science.gov (United States)

    Van Beaumont, W.; Greenleaf, J. E.; Juhos, L.

    1972-01-01

    The interrelationships between the changes in plasma volume, hematocrit, and plasma proteins during muscular exercise and bed rest were investigated. Proportionally, the changes in hematocrit are always smaller than the changes in plasma volume. For this reason changes in the concentration of blood constituents can only be quantitated on the basis of plasma volume changes. During short periods of intensive exercise, there was a small loss of plasma proteins. With prolonged submaximal exercise there was a net gain in plasma protein, which contributes to stabilization of the vascular volume. Prolonged bed rest induced hypoproteinemia; this loss of plasma protein probably plays an important role in recumbency hypovolemia.

  6. Correlation between brain volume change and T2 relaxation time induced by dehydration and rehydration: Implications for monitoring atrophy in clinical studies

    Directory of Open Access Journals (Sweden)

    Kunio Nakamura

    2014-01-01

    Our results show that pseudo-T2 may be used in conjunction with the measures of brain volume to distinguish reversible water fluctuations and irreversible brain tissue loss (atrophy and to investigate disease mechanisms related to neuro-inflammation, e.g., in multiple sclerosis, where edema-related water fluctuations may occur with disease activity and anti-inflammatory treatment.

  7. Estimating the rates of mass change, ice volume change and snow volume change in Greenland from ICESat and GRACE data

    NARCIS (Netherlands)

    Slobbe, D.C.; Ditmar, P.G.; Lindenbergh, R.C.

    2008-01-01

    The focus of this paper is on the quantification of ongoing mass and volume changes over the Greenland ice sheet. For that purpose, we used elevation changes derived from the Ice, Cloud, and land Elevation Satellite (ICESat) laser altimetry mission and monthly variations of the Earth’s gravity field

  8. Changes in plasma volume and baroreflex function following resistance exercise

    Science.gov (United States)

    Ploutz, L. L.; Tatro, D. L.; Dudley, G. A.; Convertino, V. A.

    1993-01-01

    The dynamics of change in plasma volume (PV) and baroreflex responses have been reported over 24 h immediately following maximal cycle exercise. The purpose of this study was to determine if PV and baroreflex showed similar changes for 24 h after resistance exercise. Eight men were studied on 2 test days, 1 week apart. On 1 day, per cent change (% delta) in PV was estimated at 0,3, and 6 h after resistance exercise using haematocrit and haemoglobin. Baseline PV was measured 24 h after exercise using Evans blue dye. The carotid baroreceptor-cardiac reflex response was measured before, and 3, 6, 9, 12, and 24 h post-exercise. Each subject performed six sets of the bench press and leg press with 10 repetitions per set with a load that induced failure within each set. On a control day, the protocol was used without exercise. Plasma volume did not change during the control day. There was a 20% decrease in PV immediately post-exercise; the recovery of the PV was rapid and complete within 3 h. PV was 20% greater 24 h post-exercise than on the control day. There were no differences in any of the baroreflex measurements. Therefore, it is suggested that PV shifts may occur without altering baroreflex sensitivity.

  9. Human choice and climate change. Volume 2: Resources and technology

    Energy Technology Data Exchange (ETDEWEB)

    Raynor, S.; Malone, E. [eds.] [Pacific Northwest National Lab., Richland, WA (United States)

    1998-12-31

    This book is Volume 2 of a four-volume set which assesses social science research that is relevant to global climate change from a wide-ranging interdisciplinary perspective. Attention is focused on resources and technology as they relate to climate change. This series is indispensable reading for scientists and engineers wishing to make an effective contribution to the climate change policy debate.

  10. Power law cross-correlations between price change and volume change of Indian stocks

    Science.gov (United States)

    Hasan, Rashid; Mohammed Salim, M.

    2017-05-01

    We study multifractal long-range correlations and cross-correlations of daily price change and volume change of 50 stocks that comprise Nifty index of National Stock Exchange, Mumbai, using MF-DFA and MF-DCCA methods. We find that the time series of price change are uncorrelated, whereas anti-persistent long-range multifractal correlations are found in volume change series. We also find antipersistent long-range multifractal cross-correlations between the time series of price change and volume change. As multifractality is a signature of complexity, we estimate complexity parameters of the time series of price change, volume change, and cross-correlated price-volume change by fitting the fourth-degree polynomials to their multifractal spectra. Our results indicate that the time series of price change display high complexity, whereas the time series of volume change and cross-correlated price-volume change display low complexity.

  11. Induction of Inducible Nitric Oxide Synthase by Lipopolysaccharide and the Influences of Cell Volume Changes, Stress Hormones and Oxidative Stress on Nitric Oxide Efflux from the Perfused Liver of Air-Breathing Catfish, Heteropneustes fossilis: e0150469

    National Research Council Canada - National Science Library

    Mahua G Choudhury; Nirmalendu Saha

    2016-01-01

    ...) (a bacterial endotoxin), and (b) to determine the effects of hepatic cell volume changes due to anisotonicity or by infusion of certain metabolites, stress hormones and by induction of oxidative stress on production of NO from...

  12. Residual limb volume change: Systematic review of measurement and management

    Directory of Open Access Journals (Sweden)

    Joan E. Sanders, PhD

    2011-10-01

    Full Text Available Management of residual limb volume affects decisions regarding timing of fit of the first prosthesis, when a new prosthetic socket is needed, design of a prosthetic socket, and prescription of accommodation strategies for daily volume fluctuations. This systematic review assesses what is known about measurement and management of residual limb volume change in persons with lower-limb amputation. Publications that met inclusion criteria were grouped into three categories: group I: descriptions of residual limb volume measurement techniques; group II: studies investigating the effect of residual limb volume change on clinical care in people with lower-limb amputation; and group III: studies of residual limb volume management techniques or descriptions of techniques for accommodating or controlling residual limb volume. We found that many techniques for the measurement of residual limb volume have been described but clinical use is limited largely because current techniques lack adequate resolution and in-socket measurement capability. Overall, limited evidence exists regarding the management of residual limb volume, and the evidence available focuses primarily on adults with transtibial amputation in the early postoperative phase. While we can draw some insights from the available research about residual limb volume measurement and management, further research is required.

  13. A volume change index for forest growth and sustainability

    Science.gov (United States)

    Paul Van Deusen; Francis Roesch

    2009-01-01

    A volume change index is suggested that is derived from growth components that can be estimated from remeasured plots. The new index incorporates more information than the traditional growth over removals, ratio. The new index directly indicates whether the standing volume will be increasing or decreasing if current conditions persist, whereas the ratio of...

  14. Quantitative prediction of respiratory tidal volume based on the external torso volume change: a potential volumetric surrogate

    Energy Technology Data Exchange (ETDEWEB)

    Li Guang; Arora, Naveen C; Xie Huchen; Ning, Holly; Citrin, Deborah; Kaushal, Aradhana; Zach, Leor; Camphausen, Kevin; Miller, Robert W [Radiation Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892 (United States); Lu Wei; Low, Daniel [Department of Radiation Oncology, Washington University School of Medicine, St Louis, MO 63110 (United States)], E-mail: ligeorge@mail.nih.gov

    2009-04-07

    An external respiratory surrogate that not only highly correlates with but also quantitatively predicts internal tidal volume should be useful in guiding four-dimensional computed tomography (4DCT), as well as 4D radiation therapy (4DRT). A volumetric surrogate should have advantages over external fiducial point(s) for monitoring respiration-induced motion of the torso, which deforms in synchronization with a patient-specific breathing pattern. This study establishes a linear relationship between the external torso volume change (TVC) and lung air volume change (AVC) by validating a proposed volume conservation hypothesis (TVC = AVC) throughout the respiratory cycle using 4DCT and spirometry. Fourteen patients' torso 4DCT images and corresponding spirometric tidal volumes were acquired to examine this hypothesis. The 4DCT images were acquired using dual surrogates in cine mode and amplitude-based binning in 12 respiratory stages, minimizing residual motion artifacts. Torso and lung volumes were calculated using threshold-based segmentation algorithms and volume changes were calculated relative to the full-exhalation stage. The TVC and AVC, as functions of respiratory stages, were compared, showing a high correlation (r = 0.992 {+-} 0.005, p < 0.0001) as well as a linear relationship (slope = 1.027 {+-} 0.061, R{sup 2} = 0.980) without phase shift. The AVC was also compared to the spirometric tidal volumes, showing a similar linearity (slope = 1.030 {+-} 0.092, R{sup 2} = 0.947). In contrast, the thoracic and abdominal heights measured from 4DCT showed relatively low correlation (0.28 {+-} 0.44 and 0.82 {+-} 0.30, respectively) and location-dependent phase shifts. This novel approach establishes the foundation for developing an external volumetric respiratory surrogate.

  15. Prevention of contrast-induced nephropathy with volume expansion.

    Science.gov (United States)

    Weisbord, Steven D; Palevsky, Paul M

    2008-01-01

    Contrast-induced nephropathy is one of the few preventable forms of acute kidney injury. Several pharmacologic agents have been evaluated for the prevention of contrast-induced nephropathy, yet disappointingly, few have been shown conclusively to reduce the risk for this condition. A series of studies have demonstrated that volume expansion, particularly with intravenous fluids, is an effective intervention to reduce the risk for contrast-induced nephropathy. This article reviews the clinical trials that have assessed the role of volume expansion for the prevention of contrast-induced nephropathy. The administration of isotonic sodium chloride before and after radiocontrast injection seems to be more protective than equivalent volumes of hypotonic saline and, when feasible, should be administered over a sustained period of time. Recent clinical trials suggested that an abbreviated regimen of intravenous sodium bicarbonate may be superior to a comparable protocol of sodium chloride. Although a small number of studies have found that volume supplementation by mouth may be effective in preventing contrast-induced nephropathy, the routine use of enteral fluids or solute in lieu of intravenous fluids in high-risk patients cannot be recommended at this time. Rather, liberal oral fluid and solute intake should complement intravenous fluid administration to minimize risk. Future studies will be required to define clearly the optimal prophylactic intravenous fluid regimen for contrast-induced nephropathy and further delineate the independent role of oral volume expansion for the prevention of this condition.

  16. Changes in superior mesenteric artery Doppler waveform during reduction of cardiac stroke volume and hypotension

    DEFF Research Database (Denmark)

    Perko, M J; Perko, Grazyna; Just, S

    1996-01-01

    Influence of stroke volume reduction and hypotension on the superior mesenteric artery (SMA) Doppler waveform was evaluated during head-up tilt-induced central hypovolemia in 11 healthy volunteers. During normotensive reduction in stroke volume, peak systolic velocity (pV), mean velocity, pulsati......Influence of stroke volume reduction and hypotension on the superior mesenteric artery (SMA) Doppler waveform was evaluated during head-up tilt-induced central hypovolemia in 11 healthy volunteers. During normotensive reduction in stroke volume, peak systolic velocity (pV), mean velocity...... of the study indicate that alterations in stroke volume induce consequential changes in the SMA Doppler waveform. These changes originate from both direct influence of stroke volume and/or pressure on blood flow velocity, and alterations in SMA peripheral resistance that follow variations in stroke volume....... Presented interdependencies should be taken into consideration while studying mesenteric physiology with the use of Doppler technique and while interpreting the duplex results in patients suffering from diseases that may influence flow velocity and mimic or obscure Doppler effects of the SMA stenosis....

  17. Volume change theory for syringomyelia: A new perspective.

    Science.gov (United States)

    Rai, Survendra Kumar Rajdeo; Rai, Pooja Survendra Kumar

    2015-01-01

    The etiopathogenesis of syringomyelia is still an enigma. The authors present a novel theory based on fluid dynamics at the craniovertebral (CV) junction to explain the genesis of syringomyelia (SM). The changes in volume of spinal canal, spinal cord, central canal and spinal subarachnoid space (SSS) in relation to the posterior fossa have been analysed, specifically during postural movements of flexion and extension. The effect of fluctuations in volume of spinal canal and its contents associated with cerebrospinal fluid (CSF) flow dynamics at the CV junction have been postulated to cause the origin and propagation of the syringomyelia. The relevant literature on the subject has been reviewed and the author's theory has been discussed. Volume of spinal canal in flexion is always greater than that in extension. Flexion of spine causes narrowing of the ventral subarachnoid space (SAS) and widening of dorsal SAS while extension causes reverse changes leading to fluid movement in dorsal spinal SAS in flexion and ventral spinal SAS in extension. Cervical and lumbar spinal region with maximum bulk hence maximum area and volume undergo maximum deformation during postural changes. SSS CSF is the difference between the volume of spinal canal and spinal cord, varies in flexion and extension which is compensated by changes in posterior fossa (CSF) volume in normal circumstances. Blocked SAS at foramen magnum donot permit spinal SAS CSF exchange which during postural changes is compensated by cavitatory/cystic (syrinx) change at locations in cervical and lumbar spine with propensity for maximum deformation. Augmentation of posterior fossa volume by decompression helps by normalization of this CSF exchange dynamics but immobilizing the spinal movement theoretically will cease any dynamic volume changes thereby minimizing the destructive influence of the fluid exchange on the cord. Thus, this theory strengthens the rational of treating patients by either methodology.

  18. Changes of pituitary gland volume in Kennedy disease.

    Science.gov (United States)

    Pieper, C C; Teismann, I K; Konrad, C; Heindel, W L; Schiffbauer, H

    2013-12-01

    Kennedy disease is a rare X-linked neurodegenerative disorder caused by a CAG repeat expansion in the first exon of the androgen-receptor gene. Apart from neurologic signs, this mutation can cause a partial androgen insensitivity syndrome with typical alterations of gonadotropic hormones produced by the pituitary gland. The aim of the present study was therefore to evaluate the impact of Kennedy disease on pituitary gland volume under the hypothesis that endocrinologic changes caused by partial androgen insensitivity may lead to morphologic changes (ie, hypertrophy) of the pituitary gland. Pituitary gland volume was measured in sagittal sections of 3D T1-weighted 3T-MR imaging data of 8 patients with genetically proven Kennedy disease and compared with 16 healthy age-matched control subjects by use of Multitracer by a blinded, experienced radiologist. The results were analyzed by a univariant ANOVA with total brain volume as a covariant. Furthermore, correlation and linear regression analyses were performed for pituitary volume, patient age, disease duration, and CAG repeat expansion length. Intraobserver reliability was evaluated by means of the Pearson correlation coefficient. Pituitary volume was significantly larger in patients with Kennedy disease (636 [±90] mm(3)) than in healthy control subjects (534 [±91] mm(3)) (P = .041). There was no significant difference in total brain volume (P = .379). Control subjects showed a significant decrease in volume with age (r = -0.712, P = .002), whereas there was a trend to increasing gland volume in patients with Kennedy disease (r = 0.443, P = .272). Gland volume correlated with CAG repeat expansion length in patients (r = 0.630, P = .047). The correlation coefficient for intraobserver reliability was 0.94 (P pituitary volume that correlated with the CAG repeat expansion length. This could reflect hypertrophy as the result of elevated gonadotropic hormone secretion caused by the androgen receptor mutation with partial

  19. Environmental law and climate change : Volumes I & II

    NARCIS (Netherlands)

    Verschuuren, Jonathan

    2015-01-01

    Two volume set that brings together 54 of the most influential and important scientific journal articles in the field of climate law, thematically grouped together as follows: introducing climate law, theories and approaches, climate change mitigation, climate change adaptation, climate justice, lia

  20. Pituitary volumes are changed in patients with conversion disorder.

    Science.gov (United States)

    Atmaca, Murad; Baykara, Sema; Mermi, Osman; Yildirim, Hanefi; Akaslan, Unsal

    2016-03-01

    Our study group previously measured pituitary volumes and found a relationship between somatoform disoders and pituitary volumes. Therefore, in conversion disorder, another somatoform disorder, we hypothesized that pituitary gland volumes would be reduced. Twenty female patients and healthy controls were recruited to the present investigation. The volumes of the pituitary gland were determined by using a 1.5 Tesla magnetic resonance scanner. We found that the pituitary gland volumes of the patients with conversion disorder were significantly smaller than those of healthy control subjects. In the patients with conversion disorder but not in the healthy control group, a significant negative correlation between the duration of illness and pituitary gland volume was determined. In summary, in the present study, we suggest that the patients with conversion disorder have smaller pituitary volumes compared to those of healthy control subjects. Further studies should confirm our data and ascertain whether volumetric alterations determined in the patients with conversion disorder can be changed with treatment or if they change over time.

  1. Dynamic changes of left ventricular performance and left atrial volume induced by the mueller maneuver in healthy young adults and implications for obstructive sleep apnea, atrial fibrillation, and heart failure.

    Science.gov (United States)

    Orban, Marek; Bruce, Charles J; Pressman, Gregg S; Leinveber, Pavel; Romero-Corral, Abel; Korinek, Josef; Konecny, Tomas; Villarraga, Hector R; Kara, Tomas; Caples, Sean M; Somers, Virend K

    2008-12-01

    Using the Mueller maneuver (MM) to simulate obstructive sleep apnea (OSA), our aim was to investigate acute changes in left-sided cardiac morphologic characteristics and function which might develop with apneas occurring during sleep. Strong evidence supports a relation between OSA and both atrial fibrillation and heart failure. However, acute effects of airway obstruction on cardiac structure and function have not been well defined. In addition, it is unclear how OSA might contribute to the development of atrial fibrillation and heart failure. Echocardiography was used in healthy young adults to measure various parameters of cardiac structure and function. Subjects were studied at baseline, during, and immediately after performance of the MM and after a 10-minute recovery. Continuous heart rate, blood pressure, and pulse oximetry measurements were made. During the MM, left atrial (LA) volume index markedly decreased. Left ventricular (LV) end-systolic dimension increased in association with a decrease in LV ejection fraction. On release of the maneuver, there was a compensatory increase in blood flow to the left side of the heart, with stroke volume, ejection fraction, and cardiac output exceeding baseline. After 10 minutes of recovery, all parameters returned to baseline. In conclusion, sudden imposition of severe negative intrathoracic pressure led to an abrupt decrease in LA volume and a decrease in LV systolic performance. These changes reflected an increase in LV afterload. Repeated swings in afterload burden and chamber volumes may have implications for the future development of atrial fibrillation and heart failure.

  2. Experimental Study on Volume Change Indices of Bentonite Soils

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This paper reports experimental results regarding statically compacted clay specimens to study the volume change behavior of bentonites. The volume change indices such as the coefficients of compressibility, volume compressibility, and consolidation ( i. e.av , mv and cv respectively) and the saturated coefficient of permeability k at different surcharge pressures were determined with the commonly adopted procedures. The swell potentials, swelling pressures, different phases of the swollen specimens were analyzed for the volume change behavior during compression. Experimental results revealed that the swell potential is dependent on the initial dry density, the initial water content and the vertical pressure at which the clay specimens were allowed to swell. The swelling pressure was found to be similar for the specimens with varying water content, showing strong dependency on the initial void ratio. The compression indices ( viz. mv and av) of saturated specimens decreased with an increase in the vertical pressure. About 80% to 90% of the volume change occurred in the primary compression phase under any given vertical pressure. The coefficient of consolidation cv and the saturated coefficient of permeability k decreased with an increase in the vertical pressure.

  3. Epidural anesthesia, hypotension, and changes in intravascular volume

    DEFF Research Database (Denmark)

    Holte, Kathrine; Foss, Nicolai B; Svensén, Christer

    2004-01-01

    BACKGROUND: The most common side effect of epidural or spinal anesthesia is hypotension with functional hypovolemia prompting fluid infusions or administration of vasopressors. Short-term studies (20 min) in patients undergoing lumbar epidural anesthesia suggest that plasma volume may increase when...... hypotension is present, which may have implications for the choice of treatment of hypotension. However, no long-term information or measurements of plasma volumes with or without hypotension after epidural anesthesia are available. METHODS: In 12 healthy volunteers, the authors assessed plasma (125I...... receiving hydroxyethyl starch. RESULTS: Plasma volume did not change per se after thoracic epidural anesthesia despite a decrease in blood pressure. Plasma volume increased with fluid administration but remained unchanged with vasopressors despite that both treatments had similar hemodynamic effects...

  4. [Role of paraventricular nucleus in natriuresis and diuresis induced by volume expansion in rabbits].

    Science.gov (United States)

    Zhang, B; Lin, M Z; Han, G C

    2000-02-01

    In sham-lesioned and paraventricular nucleus (PVN) lesioned rabbits, the peak increases of urine volume (UV) induced by volume expansion (VE) were 0.59+/-0.09 and 0.31+/-0.03 ml/min (P0.05). In rabbits with renal denervation there was no significant change in natriuretic response after PVN lesion (P>0.05), but lesion of PVN significantly attenuated diuretic response (P0.05). These results suggest that PVN is involved in the regulation of natriuresis and diuresis induced by VE, which are mediated by vagal afferent nerve, whereas the renal sympathetic efferent nerve may be involved in natriuretic response.

  5. Carbon dioxide effects research and assessment program. Environmental and societal consequences of a possible CO/sub 2/-induced climate change: volume II, part I. Response of the West Antarctic ice sheet to CO/sub 2/-induced climatic warming

    Energy Technology Data Exchange (ETDEWEB)

    Bentley, C.

    1982-04-01

    The paper proposes a research plan to deal with the question of what the response of the West Antarctic Ice Sheet would be to a rise in global temperatures caused by an anthropogenic CO/sub 2/ buildup in the atmosphere. The plan is designed to answer the following questions: (1) how fast is the ice mass changing now, and why; (2) how will the boundary conditions that affect the ice sheet respond to an atmospheric temperature change and how are those boundary conditions changing now; (3) what will be the response of the ice sheet to changes in boundary conditions; and (4) what can be learned by analogy with what has happened in the past. (ACR)

  6. Anatomopathological Changes Induced by Mycotoxins

    Directory of Open Access Journals (Sweden)

    Emil Tirziu

    2011-10-01

    Full Text Available Fungi or mycetes represents the biggest group of microorganisms from the entire biologic system (nearly 250.000 species, very widespread in nature. They are inferior vegetal organisms, heterotrophic, lacking chlorophyll or other trophic pigments, which grow up on live organic substrates or on decaying substrates. The intensive researches from the last two decades had proved that only 30 – 40% from the total number of fungi species is capable to synthesize some toxic metabolites, and, among this species, only 60 species had proved to be dangerous for human or animals. Researches about mycotoxins action upon factors that interfere with the natural or acquired immunity are relatively recent and most of them refer to aflatoxins. The immune-suppression phenomena rely on morphological and histological modifications of lymphoid organs, changes of blood parameters, changes of functional capacity of humoral and some cellular factors. The presence of mycotoxins in feed causes major economic losses, either by their direct action (defined by disease state or indirectly, by affecting the specific and nonspecific resistance of the organism. In the present study we studied the effect of aflatoxins upon the main organs involved in immune response, pathological changes induced by mycotoxins. To determine the influence of mycotoxins on food conversion, weighings were made at the beginning and the end of the experimental period.

  7. KCNQ1 channels sense small changes in cell volume

    DEFF Research Database (Denmark)

    Grunnet, Morten; Jespersen, Thomas; MacAulay, Nanna

    2003-01-01

    . Incubation of the oocytes in cytochalasin D and experiments with truncated KCNQ1 channels suggest that KCNQ1 channels sense cell volume changes through interactions between the cytoskeleton and the N-terminus of the channel protein. From our results we propose that KCNQ1 and KCNQ4 channels play an important...

  8. Volume Changes in Filled Rubber Under Uniaxial Cyclic Loading

    Directory of Open Access Journals (Sweden)

    Elina KAZINA

    2011-09-01

    Full Text Available Styrene-butadiene rubber, neat and filled with different silica content was investigated under uniaxial cyclic loading under a constant crosshead speed, with increasing deformation amplitude in subsequent loading cycles. Rubber was investigated in order to evaluate the reversibility of structure rearrangements, occurring in rubber when subjected to cyclic loading. Volume uniformly increases with growing strain and shows hysteresis at unloading. After complete unloading, no residual strain changes are observed. These data are in good conformity with the data of density measurements, which were made on specimens before and after the tests. By correlating data, obtained from volume changes and kinetics of hysteresis losses there were made assumptions on deformation mechanisms at different elongations. Deformational mechanisms, responsible for volume changes in rubber are reversible. Volume changes in specimen occur due to voids formation caused by filler microstructure breakage, rubber chains disentanglement, spaces between rubber macromolecular chains shrinkage, and chain slippage under higher elongations. Voids formation and deformation of rubber macromolecular chain reaches equilibrium state after certain elongation.http://dx.doi.org/10.5755/j01.ms.17.3.592

  9. Acute plasma volume change with high-intensity sprint exercise.

    Science.gov (United States)

    Bloomer, Richard J; Farney, Tyler M

    2013-10-01

    When exercise is of long duration or of moderate to high intensity, a decrease in plasma volume can be observed. This has been noted for both aerobic and resistance exercise, but few data are available with regard to high-intensity sprint exercise. We measured plasma volume before and after 3 different bouts of acute exercise, of varying intensity, and/or duration. On different days, men (n = 12; 21-35 years) performed aerobic cycle exercise (60 minutes at 70% heart rate reserve) and 2 different bouts of cycle sprints (five 60-second sprints at 100% maximum wattage obtained during graded exercise testing (GXT) and ten 15-second sprints at 200% maximum wattage obtained during GXT). Blood was collected before and 0, 30, and 60 minutes postexercise and analyzed for hematocrit and hemoglobin and plasma volume was calculated. Plasma volume decreased significantly for all exercise bouts (p sprint bouts (∼19%) compared with aerobic exercise bouts (∼11%). By 30 minutes postexercise, plasma volume approached pre-exercise values. We conclude that acute bouts of exercise, in particular high-intensity sprint exercise, significantly decrease plasma volume during the immediate postexercise period. It is unknown what, if any negative implications these transient changes may have on exercise performance. Strength and conditioning professionals may aim to rehydrate athletes appropriately after high-intensity exercise bouts.

  10. Thermal Volume Change of Unsaturated Silt under Different Stress States and Suction Magnitudes

    Directory of Open Access Journals (Sweden)

    McCartney John S.

    2016-01-01

    Full Text Available This paper presents an evaluation of the thermal volume change of compacted specimens of the same type of silt under a wide range of stress states, initial void ratios, and suction magnitudes. Stress states include both isotropic and anisotropic conditions with varying principal stress ratios, as well as normally consolidated and overconsolidated conditions. Initial void ratios range from 0.60 to 0.86, spanning very dense to loose conditions. Suctions evaluated range from saturated conditions, to low suctions in the funicular range, to suctions corresponding to residual saturation conditions. For the same soil, wide variations in thermal volume change are observed. Thermal contraction is observed for normally consolidated conditions regardless of the initial degree of saturation. Different mechanisms of thermal volume change can be used to explain the results, ranging from thermally-induced pore water pressure dissipation, to thermal collapse, to thermally-accelerated creep.

  11. Basic research of the relationship between irradiation dose and volume in radiation-induced pulmonary injury

    Institute of Scientific and Technical Information of China (English)

    PANG Qing-song; WANG Ping; WANG Jing; WANG Wei; WANG Jun; YUAN Zhi-yong

    2009-01-01

    Background Irradiation dose and volume are the major physical factors of radiation-induced lung injury.The study investigated the relationships between the irradiation dose and volume in radiation-induced lung injury by setting up a model of graded volume irradiation of the rat lung.Methods Animals were randomly assigned to three groups.The ELEKTA precise 2.03 treatment plan system was applied to calculate the irradiation dose and volume.The treatment plan for the three groups was:group 1 received a "high dose to a small volume" (25% volume group) with the mean irradiation volume being 1.748 cm3 (25% lung volume);the total dose and mean lung dose (MLD) were 4610 cGy and 2006 cGy,respectively (bilateral AP-PA fields,source to axis distance (SAD)=100 cm,6MVX,single irradiation);Group 2 received a "low dose to a large volume" (100% volume group) with the mean irradiation volume being 6.99 cm3 (100% lung volume);the total dose was 1153 cGy.MLD was 2006 cGy,which was the same as that of group 1 (bilateral AP-PA fields,SAD = 100 cm,6MVX,single irradiation);Group 3 was a control group.With the exception of receiving no irradiation,group 3 had rest steps that were the same as those of the experimental groups.After irradiation,functional,histopathological,and CT changes were compared every two weeks till the 16th week.Results Functionally,after irradiation breath rate (BR) increases were observed in both group 1 and group 2,especially during the period of 6th-8th weeks.The changes of BR in the 100% volume group were earlier and faster.For the 25% volume group,although pathology was more severe,hardly any obvious increase in BR was observed.Radiographic changes were observed during the early period (the 4th week) and the most obvious changes manifested during the mediated period (the 8th week).The extensiveness of high density and the decreased lung permeability were presented in the 100% volume group,and ground glass opacity and patchy consolidation were presented in the 25

  12. Thermomechanical Modeling of Laser-Induced Structural Relaxation and Deformation of Glass: Volume Changes in Fused Silica at High Temperatures [Thermo-mechanical modeling of laser-induced structural relaxation and deformation of SiO2 glass

    Energy Technology Data Exchange (ETDEWEB)

    Vignes, Ryan M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). National Ignition Facility and Photon Sciences; Soules, Thomas F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). National Ignition Facility and Photon Sciences; Stolken, James S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). National Ignition Facility and Photon Sciences; Settgast, Randolph R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). National Ignition Facility and Photon Sciences; Elhadj, Selim [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). National Ignition Facility and Photon Sciences; Matthews, Manyalibo J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). National Ignition Facility and Photon Sciences; Mauro, J.

    2012-12-17

    In a fully coupled thermomechanical model of the nanoscale deformation in amorphous SiO2 due to laser heating is presented. Direct measurement of the transient, nonuniform temperature profiles was used to first validate a nonlinear thermal transport model. Densification due to structural relaxation above the glass transition point was modeled using the Tool-Narayanaswamy (TN) formulation for the evolution of structural relaxation times and fictive temperature. TN relaxation parameters were derived from spatially resolved confocal Raman scattering measurements of Si–O–Si stretching mode frequencies. These thermal and microstructural data were used to simulate fictive temperatures which are shown to scale nearly linearly with density, consistent with previous measurements from Shelby et al. Volumetric relaxation coupled with thermal expansion occurring in the liquid-like and solid-like glassy states lead to residual stresses and permanent deformation which could be quantified. But, experimental surface deformation profiles between 1700 and 2000 K could only be reconciled with our simulation by assuming a roughly 2 × larger liquid thermal expansion for a-SiO2 with a temperature of maximum density ~150 K higher than previously estimated by Bruckner et al. Calculated stress fields agreed well with recent laser-induced critical fracture measurements, demonstrating accurate material response prediction under processing conditions of practical interest.

  13. Image analysis based quantification of bacterial volume change with high hydrostatic pressure.

    Science.gov (United States)

    Pilavtepe-Celik, M; Balaban, M O; Alpas, H; Yousef, A E

    2008-11-01

    Scanning electron microscopy (SEM) images of Staphylococcus aureus 485 and Escherichia coli O157:H7 933 were taken after pressure treatments at 200 to 400 MPa. Software developed for this purpose was used to analyze SEM images and to calculate the change in view area and volume of cells. Significant increase in average cell view area and volume for S. aureus 485 was observed in response to pressure treatment at 400 MPa. Cell view area for E. coli O157:H7 933 significantly increased at 325 MPa, the maximum pressure treatment tested against this pathogen. In contrast to S. aureus, cells of E. coli O157:H7 exhibited significant increase in average view area and volume at 200 MPa. The pressure-induced increase in these parameters may be attributed to modifications in membrane properties, for example, denaturation of membrane-bound proteins and pressure-induced phase transition of membrane lipid bilayer.

  14. Density assumptions for converting geodetic glacier volume change to mass change

    Directory of Open Access Journals (Sweden)

    M. Huss

    2013-05-01

    Full Text Available The geodetic method is widely used for assessing changes in the mass balance of mountain glaciers. However, comparison of repeated digital elevation models only provides a glacier volume change that must be converted to a change in mass using a density assumption or model. This study investigates the use of a constant factor for the volume-to-mass conversion based on a firn compaction model applied to simplified glacier geometries with idealized climate forcing, and two glaciers with long-term mass balance series. It is shown that the "density" of geodetic volume change is not a constant factor and is systematically smaller than ice density in most cases. This is explained by the accretion/removal of low-density firn layers, and changes in the firn density profile with positive/negative mass balance. Assuming a value of 850 ± 60 kg m−3 to convert volume change to mass change is appropriate for a wide range of conditions. For short time intervals (≤3 yr, periods with limited volume change, and/or changing mass balance gradients, the conversion factor can however vary from 0–2000 kg m−3 and beyond, which requires caution when interpreting glacier mass changes based on geodetic surveys.

  15. Measurement of cell volume changes by fluorescence self-quenching

    DEFF Research Database (Denmark)

    Hamann, Steffen; Kiilgaard, J.F.; Litman, Thomas

    2002-01-01

    At high concentrations, certain fluorophores undergo self-quenching, i.e., fluorescence intensity decreases with increasing fluorophore concentration. Accordingly, the self-quenching properties can be used for measuring water volume changes in lipid vesicles. In cells, quantitative determination...... of water transport using fluorescence self-quenching has been complicated by the requirement of relatively high (mM) and often toxic loading concentrations. Here we report a simple method that uses low (muM) loading concentrations of calcein-acetoxymethyl ester (calcein-AM) to obtain intracellular...... concentrations of the fluorophore calcein suitable for measurement of changes in cell water volume by self-quenching. The relationship between calcein fluorescence intensity, when excited at 490 nm (its excitation maximum), and calcein concentration was investigated in vitro and in various cultured cell types...

  16. Collapsibility and Volume Change Behavior of Unsaturated Residual Soil

    Directory of Open Access Journals (Sweden)

    Azalan A. Aziz

    2006-01-01

    Full Text Available Residual soils occur in most countries of the world but the greater areas and depths are normally found in tropical humid areas. In these places, the soil forming processes are still very active and the weathering development is much faster than the erosive factor. Most residual soil exhibit high suctions for most of the year. The absence of positive pore water pressure except immediately after rain, makes conventional soil mechanics for saturated soil not so relevant. Ignorance or lack of understanding of the geotechnical behavior of soil in the partially or unsaturated state has caused a lot of damages to infrastructures, buildings and other structures. For instance, the collapsibility and volume change of partially saturated soils in connection with the drying or wetting causes a lot of damage in foundation, roads and other structures. It is also observed that many shallow slope failures involve a slumping (collapse type of failure. As such, the development of extended soil mechanics, which embraces the soil in the unsaturated state or subjected to soil suction, is essential. This study examines the collapsibility and volume change behavior specifically of an unsaturated residual soil under various levels of applied matric suction (ua-uw and net mean stress (σ-ua in a predetermined stress path. The volume change of the soil is found to be sensitive to both the applied matric suction and net mean stress. The soil is found to exhibit a collapsibility behavior upon a reduction in applied matric suction at constant net mean stress.

  17. Factors Affecting Canagliflozin-Induced Transient Urine Volume Increase in Patients with Type 2 Diabetes Mellitus.

    Science.gov (United States)

    Tanaka, Hiroyuki; Takano, Kazuhiko; Iijima, Hiroaki; Kubo, Hajime; Maruyama, Nobuko; Hashimoto, Toshio; Arakawa, Kenji; Togo, Masanori; Inagaki, Nobuya; Kaku, Kohei

    2017-02-01

    Sodium glucose co-transporter 2 (SGLT2) inhibitors exhibit diuretic activity, which is a possible mechanism underlying the cardiovascular benefit of these inhibitors. However, the osmotic diuresis-induced increase in urine volume, and the risk of dehydration have been of concern with SGLT2 inhibitor treatment. This study aimed to investigate the mechanism underlying SGLT2 inhibitor canagliflozin-induced diuresis in Japanese type 2 diabetes mellitus (T2DM) patients. Thirteen T2DM patients received a daily oral dose of 100 mg canagliflozin before breakfast for 6 days. Blood and urine samples were collected at predetermined time points. The primary endpoint was evaluation of correlations between changes from baseline in urine volume and factors that are known to affect urine volume and between actual urine volume and these factors. Canagliflozin transiently increased urine volume and urinary sodium excretion on Day 1 with a return to baseline levels thereafter. Canagliflozin administration increased urinary glucose excretion, which was sustained during repeated-dose administration. Plasma atrial natriuretic peptide (ANP) and N-terminal pro-b-type natriuretic peptide (NT-proBNP) levels decreased, while plasma renin activity increased. On Day 1 of treatment, changes in sodium and potassium excretion were closely correlated with changes in urine output. A post hoc multiple regression analysis showed changes in sodium excretion and water intake as factors that affected urine volume change at Day 1. Furthermore, relative to that at baseline, canagliflozin decreased blood glucose throughout the day and increased plasma total GLP-1 after breakfast. Canagliflozin induced transient sodium excretion and did not induce water intake at Day 1; hence, natriuresis rather than glucose-induced osmotic diuresis may be a major factor involved in the canagliflozin-induced transient increase in urine output. In addition, canagliflozin decreased plasma ANP and NT-proBNP levels and

  18. Sea Level Change: Is the Volume of the Ocean Changing or Is It Redistributing?

    Science.gov (United States)

    Mitchum, G. T.; Thompson, P. R.; Merrifield, M. A.

    2012-12-01

    Global sea level change is due to changes in the ocean volume, which are in turn primarily due to changes in the globally averaged density of the ocean and ice melt from the land. Regional to local sea level changes reflect global changes as well as redistributions of volume due to ocean dynamics and land motions. Determining whether global sea level change is accelerating requires that we disentangle these regional and local signals from the true global volume changes. Given the current length of our time series determining acceleration is problematic, largely because of substantial spatial and temporal changes in the global sea level field due to ocean-atmosphere dynamics. We will review our work showing that global sea level reconstructions are sensitive to the weightings applied to the tide gauge data. We will also review basin-scale changes in sea level in the North Atlantic and the Tropical Pacific that are clearly wind-driven. These are important for two reasons. First, these signals mask the (presently) small global signal, and second, these signals present a statistical challenge for determining the acceleration of the global volume change rate. The obvious question is how well we can expect to estimate the sea level rise acceleration rate given the observed red noise character, in time and space, of the volume redistribution signals. We will end the presentation with various simulations of our ability to determine global sea level change acceleration that take into account reasonable estimates of decadal redistributions of ocean volume. The net result is that most recent attempts to determine acceleration are seriously flawed. On the positive side, we will provide estimates of how long it might take to make more reliable estimates.

  19. Density assumptions for converting geodetic glacier volume change to mass change

    Directory of Open Access Journals (Sweden)

    M. Huss

    2013-01-01

    Full Text Available The geodetic method is widely used for assessing changes in the mass balance of mountain glaciers. However, comparison of repeated digital elevation models only provides a glacier volume change that must be converted to a change in mass using a density assumption. This study investigates this conversion factor based on a firn compaction model applied to simplified glacier geometries with idealized climate forcing, and two glaciers with long-term mass balance series. It is shown that the "density" of geodetic volume change is not a constant factor and is systematically smaller than ice density in most cases. This is explained by the accretion/removal of low-density firn layers, and changes in the firn density profile with positive/negative mass balance. Assuming a value of 850 ± 60 kg m−3 to convert volume change to mass change is appropriate for a wide range of conditions. For short time intervals (≤3 yr, periods with limited volume change, and/or changing mass balance gradients, the conversion factor can however vary from 0–2000 kg m−3 and beyond which requires caution when interpreting glacier mass changes based on geodetic surveys.

  20. Extracellular Matrix Remodeling During the Progression of Volume Overload-Induced Heart Failure

    Science.gov (United States)

    Hutchinson, Kirk R.; Stewart, James A.; Lucchesi, Pamela A.

    2009-01-01

    Volume overload-induced heart failure results in progressive left ventricular remodeling characterized by chamber dilation, eccentric cardiac myocyte hypertrophy and changes in extracellular matrix (ECM) remodeling changes. The ECM matrix scaffold is an important determinant of the structural integrity of the myocardium and actively participates in force transmission across the LV wall. In response to this hemodynamic overload, the ECM undergoes a distinct pattern of remodeling that differs from pressure overload. Once thought to be a static entity, the ECM is now regarded to be a highly adaptive structure that is dynamically regulated by mechanical stress, neurohormonal activation, inflammation and oxidative stress, that result in alterations in collagen and other matrix components and a net change in matrix metalloproteinase (MMP) expression and activation. These changes dictate overall ECM turnover during volume overload hear failure progression. This review will discuss the cellular and molecular mechanisms that dictate the temporal patterns of ECM remodeling during heart disease progression. PMID:19524591

  1. Laser-induced incandescence: Towards quantitative soot volume fraction measurements

    Energy Technology Data Exchange (ETDEWEB)

    Tzannis, A.P.; Wienbeucker, F.; Beaud, P.; Frey, H.-M.; Gerber, T.; Mischler, B.; Radi, P.P. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    Laser-Induced Incandescence has recently emerged as a versatile tool for measuring soot volume fraction in a wide range of combustion systems. In this work we investigate the essential features of the method. LII is based on the acquisition of the incandescence of soot when heated through a high power laser pulse. Initial experiments have been performed on a model laboratory flame. The behaviour of the LII signal is studied experimentally. By applying numerical calculations we investigate the possibility to obtain two-dimensional soot volume fraction distributions. For this purpose a combination of LII with other techniques is required. This part is discussed in some extent and the future work is outlined. (author) 4 figs., 3 refs.

  2. Changes in molar volume and heat capacity of actin upon polymerization.

    Science.gov (United States)

    Quirion, F; Gicquaud, C

    1993-11-01

    We have used densimetry and microcalorimetry to measure the changes in molar volume and heat capacity of the actin molecule during Mg(2+)-induced polymerization. Molar volume is decreased by 720 ml/mol. This result is in contradiction with previous measurements by Ikkai and Ooi [(1966) Science 152, 1756-1757], and by Swezey and Somero [(1985) Biochemistry 24, 852-860]: both of these groups reported increases in actin volume during polymerization, of 391 ml/mol and 63 ml/mol respectively. We also observed a decrease in heat capacity of about 69.5 kJ.K-1.mol-1 during polymerization. This is in agreement with the concept of conformational fluctuation of proteins proposed by Lumry and Gregory [(1989) J.Mol. Liq. 42, 113-144]whereby either ligand binding by a protein or monomer-monomer interaction decreases the protein's conformational flexibility.

  3. Age-related changes in body fluid volumes in young spontaneously hypertensive rats

    Energy Technology Data Exchange (ETDEWEB)

    Von Dreele, M.M. (Wright State Univ., Dayton, OH (USA))

    1988-11-01

    The authors have measured total body water (TBW, by dessiccation), extracellular fluid volume (ECF, Na{sub 2}{sup 35}SO{sub 4} space), and plasma volume (PV, radioiodinated serum albumin space) in 5-sec-butyl-5-ethyl-2-thiobarbituric acid and sodium salt (Inactin)-anesthetized spontaneously hypertensive (SHR) and Wistar-Kyoto (WKY) rats aged 12-60 days. Interstitial fluid volume (ISF) was calculated as ECF minus PV. Changes in TBW, ECF, and ISF were largely a function of age in both strains, which is typical of developing mammals. Further analysis revealed that although these volumes were significantly larger in SHR before 25 days of age, after 30 days no difference existed between the strains. Before 25 days of age, when SHR's TBW was expanded, no weight difference was seen between the strains. However, once TBW was normalized (after 30 days), WKY was significantly heavier than SHR. The ISF volume was preferentially enlarged in SHR, although PV was also periodically greater. ISF normalized at the time when blood pressure becomes significantly higher in SHR, when plasma aldosterone falls to WKY values in SHR and when renal function is approaching adult levels. Thus the return of ECF (ISF) to normal values may be a result of decreased aldosterone-dependent volume retention or to diuresis induced by increasing blood pressure in an animal whose renal function is close to maturity.

  4. Listening to PS II: enthalpy, entropy, and volume changes.

    Science.gov (United States)

    Hou, Harvey J M; Mauzerall, David

    2011-01-01

    Photosystem II, located in the thylakoid membranes of green plants, algae, and cyanobacteria, uses sunlight to split water into protons, electrons, and a dioxygen molecule. The mechanism of its electron transfers and oxygen evolution including the structure of the protein and rates of the S-state cycle has been extensively investigated. Substantial progress has been made; however, the thermodynamics of PS II electron transfer and of the oxygen cycle are poorly understood. Recent progress in thermodynamic measurements in photosynthesis provides novel insights on the enthalpic and entropic contribution to electron transfer in proteins. In this review the thermodynamic parameters including quantum yield, enthalpy, entropy, and volume changes of PS II photochemistry determined by photoacoustics and other laser techniques are summarized and evaluated. Light-driven volume changes via electrostriction are directly related to the photoreaction in PS II and thus can be a useful measurement of PS II activity and function. The enthalpy changes of the reactions observed can be directly measured by photoacoustics. The apparent reaction entropy can also be estimated when the free energy is known. Dissecting the free energy of a photoreaction into enthalpic and entropic components provides critical information about mechanisms of PS II function. Potential limitations and future direction of the study of the thermodynamics of PS II electron transfer and oxygen evolution are presented.

  5. Total meltwater volume since the Last Glacial Maximum and viscosity structure of Earth's mantle inferred from relative sea level changes at Barbados and Bonaparte Gulf and GIA-induced J˙2

    Science.gov (United States)

    Nakada, Masao; Okuno, Jun'ichi; Yokoyama, Yusuke

    2016-02-01

    Inference of globally averaged eustatic sea level (ESL) rise since the Last Glacial Maximum (LGM) highly depends on the interpretation of relative sea level (RSL) observations at Barbados and Bonaparte Gulf, Australia, which are sensitive to the viscosity structure of Earth's mantle. Here we examine the RSL changes at the LGM for Barbados and Bonaparte Gulf ({{RSL}}_{{L}}^{{{Bar}}} and {{RSL}}_{{L}}^{{{Bon}}}), differential RSL for both sites (Δ {{RSL}}_{{L}}^{{{Bar}},{{Bon}}}) and rate of change of degree-two harmonics of Earth's geopotential due to glacial isostatic adjustment (GIA) process (GIA-induced J˙2) to infer the ESL component and viscosity structure of Earth's mantle. Differential RSL, Δ {{RSL}}_{{L}}^{{{Bar}},{{Bon}}} and GIA-induced J˙2 are dominantly sensitive to the lower-mantle viscosity, and nearly insensitive to the upper-mantle rheological structure and GIA ice models with an ESL component of about (120-130) m. The comparison between the predicted and observationally derived Δ {{RSL}}_{{L}}^{{{Bar}},{{Bon}}} indicates the lower-mantle viscosity higher than ˜2 × 1022 Pa s, and the observationally derived GIA-induced J˙2 of -(6.0-6.5) × 10-11 yr-1 indicates two permissible solutions for the lower mantle, ˜1022 and (5-10) × 1022 Pa s. That is, the effective lower-mantle viscosity inferred from these two observational constraints is (5-10) × 1022 Pa s. The LGM RSL changes at both sites, {{RSL}}_{{L}}^{{{Bar}}} and {{RSL}}_{{L}}^{{{Bon}}}, are also sensitive to the ESL component and upper-mantle viscosity as well as the lower-mantle viscosity. The permissible upper-mantle viscosity increases with decreasing ESL component due to the sensitivity of the LGM sea level at Bonaparte Gulf ({{RSL}}_{{L}}^{{{Bon}}}) to the upper-mantle viscosity, and inferred upper-mantle viscosity for adopted lithospheric thicknesses of 65 and 100 km is (1-3) × 1020 Pa s for ESL˜130 m and (4-10) × 1020 Pa s for ESL˜125 m. The former solution of (1-3) × 1020

  6. Changes in extracellular muscle volume affect heart rate and blood pressure responses to static exercise

    Science.gov (United States)

    Baum, K.; Essfeld, D.; Stegemann, J.

    To investigate the effect of μg-induced peripheral extracellular fluid reductions on heart rate and blood pressure during isometric exercise, six healthy male subjects performed three calf ergometer test with different extracellular volumes of working muscles. In all tests, body positions during exercise were identical (supine with the knee joint flexed to 900). After a pre-exercise period of 25 min, during which calf volumes were manipulated, subjects had to counteract an external force of 180 N for 5 min. During the pre-exercise period three different protocols were applied. Test A: Subjects rested in the exercise position; test B: Body position was the same as in A but calf volume was increased by venous congestion (cuffs inflated to 80 mm Hg); test C: Calf volumes were decreased by a negative hydrostatic pressure (calves about 40 cm above heart level with the subjects supine). To clamp the changed calf volumes in tests B and C, cuffs were inflated to 300 mm Hg 5 min before the onset of exercise. This occlusion was maintained until termination of exercise. Compared to tests A and B, the reduced volume of test C led to significant increases in heart rate and blood pressure during exercise. Oxygen uptake did not exceed resting levels in B and C until cuffs were deflated, indicating that exclusively calf muscles contributed to the neurogenic peripheral drive. It is concluded that changes in extracellular muscle volume have to be taken into account when comparing heart rate and blood pressure during lg- and μg- exercise.

  7. Comparative changes in plasma protein concentration, hematocrit and plasma volume during exercise, bedrest and + Gz acceleration.

    Science.gov (United States)

    Van Beaumont, W.; Greenleaf, J. E.

    1972-01-01

    Discussion of experiments which indicate that under conditions of a constant red cell volume the proportional changes in hematocrit and plasma volume during exercise are never equal. On the basis of direct measurements and calculated changes of plasma volume it is concluded that during maximal exercise there is a small loss of protein from the plasma. It is clear that changes in content of blood constituents can only be evaluated correctly after determination of changes in plasma volume.

  8. Is climate change human induced?

    African Journals Online (AJOL)

    user

    reports follow exhaustive review process, and are widely accepted. In 2007, IPCC's 4th assessment report- 'Climate Change 2007 – Impacts, Adaptation and Vulnerability' came into ... is disturbing regional eco-balance, but increasing vehicular pollution in climate- ... subcontinent by sheltering it from the cold air mass of.

  9. Beach Volume Change Using Uav Photogrammetry Songjung Beach, Korea

    Science.gov (United States)

    Yoo, C. I.; Oh, T. S.

    2016-06-01

    Natural beach is controlled by many factors related to wave and tidal forces, wind, sediment, and initial topography. For this reason, if numerous topographic data of beach is accurately collected, coastal erosion/acceleration is able to be assessed and clarified. Generally, however, many studies on coastal erosion have limitation to analyse the whole beach, carried out of partial area as like shoreline (horizontal 2D) and beach profile (vertical 2D) on account of limitation of numerical simulation. This is an important application for prevention of coastal erosion, and UAV photogrammetry is also used to 3D topographic data. This paper analyses the use of unmanned aerial vehicles (UAV) to 3D map and beach volume change. UAV (Quadcopter) equipped with a non-metric camera was used to acquire images in Songjung beach which is located south-east Korea peninsula. The dynamics of beach topography, its geometric properties and estimates of eroded and deposited sand volumes were determined by combining elevation data with quarterly RTK-VRS measurements. To explore the new possibilities for assessment of coastal change we have developed a methodology for 3D analysis of coastal topography evolution based on existing high resolution elevation data combined with low coast, UAV and on-ground RTK-VRS surveys. DSMs were obtained by stereo-matching using Agisoft Photoscan. Using GCPs the vertical accuracy of the DSMs was found to be 10 cm or better. The resulting datasets were integrated in a local coordinates and the method proved to be a very useful fool for the detection of areas where coastal erosion occurs and for the quantification of beach change. The value of such analysis is illustrated by applications to coastal of South Korea sites that face significant management challenges.

  10. BEACH VOLUME CHANGE USING UAV PHOTOGRAMMETRY SONGJUNG BEACH, KOREA

    Directory of Open Access Journals (Sweden)

    C. I. Yoo

    2016-06-01

    Full Text Available Natural beach is controlled by many factors related to wave and tidal forces, wind, sediment, and initial topography. For this reason, if numerous topographic data of beach is accurately collected, coastal erosion/acceleration is able to be assessed and clarified. Generally, however, many studies on coastal erosion have limitation to analyse the whole beach, carried out of partial area as like shoreline (horizontal 2D and beach profile (vertical 2D on account of limitation of numerical simulation. This is an important application for prevention of coastal erosion, and UAV photogrammetry is also used to 3D topographic data. This paper analyses the use of unmanned aerial vehicles (UAV to 3D map and beach volume change. UAV (Quadcopter equipped with a non-metric camera was used to acquire images in Songjung beach which is located south-east Korea peninsula. The dynamics of beach topography, its geometric properties and estimates of eroded and deposited sand volumes were determined by combining elevation data with quarterly RTK-VRS measurements. To explore the new possibilities for assessment of coastal change we have developed a methodology for 3D analysis of coastal topography evolution based on existing high resolution elevation data combined with low coast, UAV and on-ground RTK-VRS surveys. DSMs were obtained by stereo-matching using Agisoft Photoscan. Using GCPs the vertical accuracy of the DSMs was found to be 10 cm or better. The resulting datasets were integrated in a local coordinates and the method proved to be a very useful fool for the detection of areas where coastal erosion occurs and for the quantification of beach change. The value of such analysis is illustrated by applications to coastal of South Korea sites that face significant management challenges.

  11. Size and sequence and the volume change of protein folding.

    Science.gov (United States)

    Rouget, Jean-Baptiste; Aksel, Tural; Roche, Julien; Saldana, Jean-Louis; Garcia, Angel E; Barrick, Doug; Royer, Catherine A

    2011-04-20

    The application of hydrostatic pressure generally leads to protein unfolding, implying, in accordance with Le Chatelier's principle, that the unfolded state has a smaller molar volume than the folded state. However, the origin of the volume change upon unfolding, ΔV(u), has yet to be determined. We have examined systematically the effects of protein size and sequence on the value of ΔV(u) using as a model system a series of deletion variants of the ankyrin repeat domain of the Notch receptor. The results provide strong evidence in support of the notion that the major contributing factor to pressure effects on proteins is their imperfect internal packing in the folded state. These packing defects appear to be specifically localized in the 3D structure, in contrast to the uniformly distributed effects of temperature and denaturants that depend upon hydration of exposed surface area upon unfolding. Given its local nature, the extent to which pressure globally affects protein structure can inform on the degree of cooperativity and long-range coupling intrinsic to the folded state. We also show that the energetics of the protein's conformations can significantly modulate their volumetric properties, providing further insight into protein stability.

  12. Interleukin-1 inhibits osmotically-induced calcium signaling and volume regulation in articular chondrocytes

    Science.gov (United States)

    Pritchard, Scott; Votta, Bartholomew J.; Kumar, Sanjay; Guilak, Farshid

    2011-01-01

    OBJECTIVE Articular chondrocytes respond to osmotic stress with transient changes in cell volume and the intracellular concentration of calcium ion ([Ca2+]i). The goal of this study was to examine the hypothesis that interleukin-1 (IL-1), a pro-inflammatory cytokine associated with osteoarthritis, influences osmotically-induced Ca2+ signaling. METHODS Fluorescence ratio imaging was used to measure [Ca2+]i and cell volume in response to hypo- or hyper-osmotic stress in isolated porcine chondrocytes, with or without pre-exposure to 10 ng/ml IL-1α. Inhibitors of IL-1 (IL-1 receptor antagonist, IL-Ra), Ca2+ mobilization (thapsigargin, an inhibitor of Ca-ATPases), and cytoskeletal remodeling (Toxin B, an inhibitor of the Rho family of small GTPases) were used to determine the mechanisms involved in increased [Ca2+]i, F-actin remodeling, volume adaptation and active volume recovery. RESULTS In response to osmotic stress, chondrocytes exhibited transient increases in [Ca2+]i, generally followed by decaying oscillations. Pre-exposure to IL-1 significantly inhibited regulatory volume decrease following hypo-osmotic swelling and reduced the change in cell volume and the time to peak [Ca2+]i in response to hyper-osmotic stress, but did not affect the peak magnitudes of [Ca2+]i in those cells that did response. Co-treatment with IL-1Ra, thapsigargin, or Toxin B restored these responses to control levels. The effects were associated with alterations in F-actin organization. CONCLUSIONS IL-1 alters the normal volumetric and Ca2+ signaling response of chondrocytes to osmotic stress through mechanisms involving F-actin remodeling via small Rho GTPases. These findings provide further insights into the mechanisms by which IL-1 may interfere with normal physiologic processes in the chondrocyte, such as the adaptation or regulatory responses to mechanical and osmotic loading. PMID:18495501

  13. Study on Volume Strain Inversion from Water Level Change of Well-aquifer Systems

    Institute of Scientific and Technical Information of China (English)

    Yan Rui; Gao Fuwang; Chen Yong

    2008-01-01

    Based on linear poroelastic and hydrogcology theory, a mathematical expression describing the relationship between water level change and aquifer volume strain is put forward. Combined with earth tidal theory, we analyze the response characteristics from well-aquifer water level change to earth tide of volume strain and present a method of volume strain inversion from water level change. Comparing the results of inversion with real observed data, we found that there is a good consistency. This suggcsts that the method of volume strain inversion from water level change is proper. It will offer a reference for learning about hydrogeology characteristics, volume strain and searching for precursor anomalies.

  14. A prediction model of radiation-induced necrosis for intracranial radiosurgery based on target volume.

    Science.gov (United States)

    Zhao, Bo; Wen, Ning; Chetty, Indrin J; Huang, Yimei; Brown, Stephen L; Snyder, Karen C; Siddiqui, Farzan; Movsas, Benjamin; Siddiqui, M Salim

    2017-08-01

    This study aims to extend the observation that the 12 Gy-radiosurgical-volume (V12Gy) correlates with the incidence of radiation necrosis in patients with intracranial tumors treated with radiosurgery by using target volume to predict V12Gy. V12Gy based on the target volume was used to predict the radiation necrosis probability (P) directly. Also investigated was the reduction in radiation necrosis rates (ΔP) as a result of optimizing the prescription isodose lines for linac-based SRS. Twenty concentric spherical targets and 22 patients with brain tumors were retrospectively studied. For each case, a standard clinical plan and an optimized plan with prescription isodose lines based on gradient index were created. V12Gy were extracted from both plans to analyze the correlation between V12Gy and target volume. The necrosis probability P as a function of V12Gy was evaluated. To account for variation in prescription, the relation between V12Gy and prescription was also investigated. A prediction model for radiation-induced necrosis was presented based on the retrospective study. The model directly relates the typical prescribed dose and the target volume to the radionecrosis probability; V12Gy increased linearly with the target volume (R(2)  > 0.99). The linear correlation was then integrated into a logistic model to predict P directly from the target volume. The change in V12Gy as a function of prescription was modeled using a single parameter, s (=-1.15). Relatively large ΔP was observed for target volumes between 7 and 28 cm(3) with the maximum reduction (8-9%) occurring at approximately 18 cm(3) . Based on the model results, optimizing the prescription isodose line for target volumes between 7 and 28 cm(3) results in a significant reduction in necrosis probability. V12Gy based on the target volume could provide clinicians a predictor of radiation necrosis at the contouring stage thus facilitating treatment decisions. © 2017 American Association of

  15. Experimental study of acute lung injury induced by different tidal volume ventilation in rats

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xin-ri; DU Yong-cheng; JIANG Hong-ying; XU Jian-ying; XU Yong-jian

    2005-01-01

    @@ Mechanical ventilation (MV) is a dual blade sward which if misused could lead to lung injury, called ventilator induced lung injury (VILI). Pathogenesis of VILI is very complex with various manifestations, which is the focus in MV field in recent years.1 In our research, the rats were ventilated with different tidal volume, then the pathological changes of the lungs were observed under macroscopy, light and electronic microscope, and various laboratory tests in blood and bronchoalveolar lavage fluid (BALF) were also carried out in order to probe further the pathologic characteristics and the pathogenesis of VILI.

  16. A change in the electro-physical properties of narrow-band CdHgTe solid solutions acted upon by a volume discharge induced by an avalanche electron beam in the air at atmospheric pressure

    Science.gov (United States)

    Voitsekhovskii, A. V.; Grigor'ev, D. V.; Korotaev, A. G.; Kokhanenko, A. P.; Tarasenko, V. F.; Shulepov, M. A.

    2012-03-01

    The effect of a nanosecond volume discharge forming in an inhomogeneous electrical field at atmospheric pressure on the CdHgTe (MCT) epitaxial films of the p-type conduction with the hole concentration 2·1016 cm3 and mobility 500 cm2·V-1·s-1 is studied. The measurement of the electrophysical parameters of the MCT specimens upon irradiation shows that a layer exhibiting the n-type conduction is formed in the near-surface region of the epitaxial films. After 600 pulses and more, the thickness and the parameters of the layer are such that the measured field dependence of the Hall coefficient corresponds to the material of the n-type conduction. Analysis of the preliminary results reveals that the foregoing nanosecond volume discharge in the air at atmospheric pressure is promising for modification of electro-physical MCT properties.

  17. Factors influencing liver and spleen volume changes after donor hepatectomy for living donor liver transplantation

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Ji Hee; Ryeom, Hunku; Song, Jung Hup [Kyungpook National University Hospital, Daegu (Korea, Republic of)

    2013-11-15

    To define the changes in liver and spleen volumes in the early postoperative period after partial liver donation for living-donor liver transplantation (LDLT) and to determine factors that influence liver and spleen volume changes. 27 donors who underwent partial hepatectomy for LDLT were included in this study. The rates of liver and spleen volume change, measured with CT volumetry, were correlated with several factors. The analyzed factors included the indocyanine green (ICG) retention rate at 15 minutes after ICG administration, preoperative platelet count, preoperative liver and splenic volumes, resected liver volume, resected-to-whole liver volume ratio (LV{sub R}/LV{sub W}), resected liver volume to the sum of whole liver and spleen volume ratio [LV{sub R}/(LV{sub W} + SV{sub 0})], and pre and post hepatectomy portal venous pressures. In all hepatectomy donors, the volumes of the remnant liver and spleen were increased (increased rates, 59.5 ± 50.5%, 47.9 ± 22.6%). The increment rate of the remnant liver volume revealed a positive correlation with LV{sub R}/LV{sub W} (r = 0.759, p < 0.01). The other analyzed factors showed no correlation with changes in liver and spleen volumes. The spleen and remnant liver volumes were increased at CT volumetry performed 2 weeks after partial liver donation. Among the various analyzed factors, LV{sub R}/LV{sub W} influences the increment rate of the remnant liver volume.

  18. VMAT-Mediated changes in quantal size and vesicular volume

    NARCIS (Netherlands)

    Colliver, T L; Pyott, S J; Achalabun, M; Ewing, A G

    2000-01-01

    It has been well established that the volume of secretory vesicles can be modulated. However, we present the first data demonstrating that the amount of transmitter in a vesicle can regulate its volume. Amperometry and transmission electron microscopy have been used to determine that l-3,4-dihydroxy

  19. Compensating temperature-induced ultrasonic phase and amplitude changes

    Science.gov (United States)

    Gong, Peng; Hay, Thomas R.; Greve, David W.; Junker, Warren R.; Oppenheim, Irving J.

    2016-04-01

    In ultrasonic structural health monitoring (SHM), environmental and operational conditions, especially temperature, can significantly affect the propagation of ultrasonic waves and thus degrade damage detection. Typically, temperature effects are compensated using optimal baseline selection (OBS) or optimal signal stretch (OSS). The OSS method achieves compensation by adjusting phase shifts caused by temperature, but it does not fully compensate phase shifts and it does not compensate for accompanying signal amplitude changes. In this paper, we develop a new temperature compensation strategy to address both phase shifts and amplitude changes. In this strategy, OSS is first used to compensate some of the phase shifts and to quantify the temperature effects by stretching factors. Based on stretching factors, empirical adjusting factors for a damage indicator are then applied to compensate for the temperature induced remaining phase shifts and amplitude changes. The empirical adjusting factors can be trained from baseline data with temperature variations in the absence of incremental damage. We applied this temperature compensation approach to detect volume loss in a thick wall aluminum tube with multiple damage levels and temperature variations. Our specimen is a thick-walled short tube, with dimensions closely comparable to the outlet region of a frac iron elbow where flow-induced erosion produces the volume loss that governs the service life of that component, and our experimental sequence simulates the erosion process by removing material in small damage steps. Our results show that damage detection is greatly improved when this new temperature compensation strategy, termed modified-OSS, is implemented.

  20. Peritoneal residual volume induces variability of ultrafiltration with icodextrin.

    Science.gov (United States)

    Akonur, Alp; Holmes, Clifford J; Leypoldt, John K

    2014-01-01

    Icodextrin induces ultrafiltration (UF) during long-dwell exchanges by creating a difference in oncotic pressure between the peritoneal cavity and plasma; however, the mechanisms governing intra-patient and inter-patient variability in UF when icodextrin is used remain largely unexplained. In the present study, we show theoretically that differences in peritoneal residual volume (VR) have a more profound effect on UF with icodextrin use than with glucose use. This phenomenon is attributed to a differential effect of VR on oncotic, rather than osmotic, pressure between the peritoneal cavity and plasma. ♢ The three-pore model was used to calculate the effect on UF of VR between 150 mL and 1200 mL when 7.5% icodextrin (ICO) or 3.86% glucose solution is used at the end of a 12-hour dwell in the four patient transport groups (that is, fast to slow). Oncotic (with ICO) and osmotic (with glucose) pressure differences averaged over the entire dwell were also calculated. ♢ As expected, at a nominal VR of 300 mL, UF with glucose differed substantially between the four patient transport groups (2 - 804 mL), whereas UF with ICO did not (556 - 573 mL). When VR was increased to 1200 mL from 150 mL, the concentrations of the oncotic and osmotic agents at the start of the dwell with an infusion volume of 2 L decreased to 4.9% from 7.0% with ICO and to 2.5% from 3.6% with glucose. The decrease in UF on average was greater with ICO [to 252 mL from 624 mL: that is, a reduction of 372 mL (60%)] than with glucose [to 292 mL from 398 mL: that is, a reduction of 106 mL (27%)]. Those trends agreed with the calculated reductions in the oncotic pressure difference with ICO [reduction of 12 mmHg (49%)] and the osmotic pressure difference with glucose [reduction of 19 mmHg (33%)]. ♢ When ICO is used, VR modifies the oncotic pressure difference between the peritoneal cavity and plasma to substantially alter UF. This modification suggests that potential causes of increased VR should be

  1. STUDY ON COPOLYMER EPOXY RESIN MATRIX WITHOUT SHRINKAGE PART I VOLUME CHANGE DURING CURE PROCESSES

    Institute of Scientific and Technical Information of China (English)

    HE Pingsheng; ZHOU Zhiqiang; WANG Gengchao; PAN Caiyuan; WU Renjie

    1988-01-01

    The volume change of the copolymer epoxy resins can be controlled by copolymerizing epoxy resin E51 with 3,9-di (5-norbornene-2, 2)-1, 5, 7, 11-tetraoxaspiro [5, 5] undecane (NSOC). During curing,the volume changes of copolymer epoxy resins with various amounts of NSOC were measured with a dilatometer. Cure process does not produce volume change when epoxy resin E51: NSOC is 5.88: 1 in equivalent.

  2. Diglossia and Contact-Induced Language Change

    Science.gov (United States)

    Sayahi, Lotfi

    2007-01-01

    The present paper assesses the implications of the existence of two varieties of the same language for contact-induced language change in cases of bilingualism. By analysing the contact between French and Tunisian Arabic, on the one hand, and Spanish and Northern Moroccan Arabic, on the other, the purpose is to illustrate how the coexistence of…

  3. Effect of Bcl-2 rs956572 polymorphism on age-related gray matter volume changes.

    Directory of Open Access Journals (Sweden)

    Mu-En Liu

    Full Text Available The anti-apoptotic protein B-cell CLL/lymphoma 2 (Bcl-2 gene is a major regulator of neural plasticity and cellular resilience. Recently, the Bcl-2 rs956572 single nucleotide polymorphism was proposed to be a functional allelic variant that modulates cellular vulnerability to apoptosis. Our cross-sectional study investigated the genetic effect of this Bcl-2 polymorphism on age-related decreases in gray matter (GM volume across the adult lifespan. Our sample comprised 330 healthy volunteers (191 male, 139 female with a mean age of 56.2±22.0 years (range: 21-92. Magnetic resonance imaging and genotyping of the Bcl-2 rs956572 were performed for each participant. The differences in regional GM volumes between G homozygotes and A-allele carriers were tested using optimized voxel-based morphometry. The association between the Bcl-2 rs956572 polymorphism and age was a predictor of regional GM volumes in the right cerebellum, bilateral lingual gyrus, right middle temporal gyrus, and right parahippocampal gyrus. We found that the volume of these five regions decreased with increasing age (all P<.001. Moreover, the downward slope was steeper among the Bcl-2 rs956572 A-allele carriers than in the G-homozygous participants. Our data provide convergent evidence for the genetic effect of the Bcl-2 functional allelic variant in brain aging. The rs956572 G-allele, which is associated with significantly higher Bcl-2 protein expression and diminished cellular sensitivity to stress-induced apoptosis, conferred a protective effect against age-related changes in brain GM volume, particularly in the cerebellum.

  4. Environmental and societal consequences of a possible CO/sub 2/-induced climate change. Volume II, Part 8. Impacts of rising atmospheric carbon dioxide levels on agricultural growing seasons and crop water use efficiencies

    Energy Technology Data Exchange (ETDEWEB)

    Newman, J. E.

    1982-09-01

    The researchable areas addressed relate to the possible impacts of climate change on agricultural growing seasons and crop adaptation responses on a global basis. The research activities proposed are divided into the following two main areas of investigation: anticipated climate change impacts on the physical environmental characteristics of the agricultural growing seasons and, the most probable food crop responses to the possible changes in atmospheric CO/sub 2/ levels in plant environments. The main physical environmental impacts considered are the changes in temperature, or more directly, thermal energy levels and the growing season evapotranspiration-precipitation balances. The resulting food crop, commercial forest and rangeland species response impacts addressed relate to potential geographical shifts in agricultural growing seasons as determined by the length in days of the frost free period, thermal energy changes and water balance changes. In addition, the interaction of possible changes in plant water use efficiencies during the growing season in relationship to changing atmospheric CO/sub 2/ concentrations, is also considered under the scenario of global warming due to increases in atmospheric CO/sub 2/ concentration. These proposed research investigations are followed by adaptive response evaluations.

  5. BID Mediates Oxygen-Glucose Deprivation-Induced Neuronal Injury in Organotypic Hippocampal Slice Cultures and Modulates Tissue Inflammation in a Transient Focal Cerebral Ischemia Model without Changing Lesion Volume

    DEFF Research Database (Denmark)

    Martin, Nellie Anne; Bonner, Helena; Elkjær, Maria Louise

    2016-01-01

    The BH3 interacting-domain death agonist (BID) is a pro-apoptotic protein involved in death receptor-induced and mitochondria-mediated apoptosis. Recently, it has also been suggested that BID is involved in the regulation of inflammatory responses in the central nervous system. We found that BID ...

  6. Free Volume Changes in γ-Irradiated Polyethylene andPolytetraflourethylene

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Positron lifetime spectrum was measured and the change of the free volume was studied for commercial polyethylene (PE) and polytetrafluoroethylene (PTFE) during γ-irradiation processingup to 265 kGy. The free volume size increases but the crystallinity decreases as irradiation doseincreases in PE. Both qualities (free volume size and crystallinity) in PTFE display an oppositebehavior. The fractional free volume reduces monotonically with increasing irradiation dose inboth PE and PTFE. The competition between the crosslinking and the splitting decompositionin polymers can be used to understand the free volume changes with irradiation dose.

  7. Assessment of positive end-expiratory pressure induced lung volume change by ultrasound in mechanically ventilated patients%床旁超声对机械通气患者呼气末正压诱导肺容积改变的评估价值

    Institute of Scientific and Technical Information of China (English)

    沈鹏; 罗汝斌; 高玉芝; 王吉文; 张茂

    2014-01-01

    Objective To investigate the value of lung ultrasound for assessing positive endexpiratory pressure (PEEP)-induced lung volume change in mechanically ventilated patients with acute lung injury(ALI) or acute respiratory distress syndrome (ARDS).Methods Eighteen patients with ALI or ARDS were prospectively studied.P-V curves and lung ultrasound were performed at PEEP 12,8,4 and 0 cmH2O(1 cmH2O =0.098 kPa).PEEP-induced lung volume change was measured using the P-V curve method and lung ultrasound.Results Four lung ultrasound entities were defined:consolidation,multiple irregularly spaced B lines,multiple abutting B lines and normal aeration.For each of the 12 lung regions examined,PEEP-induced ultrasound changes were measured and an lung ultrasound score (LUS)was calculated.A highly significant correlation was found between PEEP-induced lung volume change measured by P-V curves and LUS change (r =0.82,P < 0.01).A statistically significant correlation was found between LUS change and PEEP-induced increase in PaO2 (r =0.66,P < 0.01).Conclusion PEEP-induced lung volume change can be adequately estimated with bedside lung ultrasound.Since lung ultrasound cannot assess PEEP-induced lung hyperinflation,it should not be the sole method for PEEP titration.%目的 探讨床旁超声在机械通气患者呼气末正压(PEEP)诱导肺容积改变的评估价值.方法 选取2011年6月至2012年12月浙江大学医学院附属第二医院急诊监护室(EICU)内符合急性肺损伤(ALI)或ARDS并接受机械通气的患者,采用Taema XTEND系列呼吸机专利的压力容积曲线测定程序自动测定PEEP为12、8、4、0 cmH2O(1 cmH2O =0.098 kPa)时的压力容积曲线,得到不同PEEP水平下的呼气末肺容积(EELV)并计算呼气末肺容积变化(△EELV),根据△EELV变化确定合适PEEP,在呼吸机测定压力容积曲线的同时使用床旁超声评估肺容积变化,计算肺部超声评分(LUS)及肺部超声评分变化(△LUS),相关计量数据进

  8. Separate and combined influence of posture and sprint running on plasma volume changes.

    Science.gov (United States)

    Tsampoukos, Antonios; Stokes, Keith; Nevill, Mary

    2014-01-01

    It is currently unknown whether any changes in plasma volume (PV) after sprint running are inherent to sprint running per se or are due to other confounding factors such as changes in posture. The purpose of the present study was to examine the independent effects of sprint running on PV changes. Eight females completed two trials on separate days: (1) a 30-s sprint on a non-motorised treadmill and (2) a control trial where no exercise was undertaken but blood samples were taken at identical time points as in the exercise trial. Changes in PV were calculated using haematocrit and haemoglobin. Post-sprint PV reductions were greater in the sprint than the control trial (mean: -17.7, SD=3.1% vs. mean: -7.5, s = 4.9, Psprint than the control trial in most sampling points. These data show that sprint running of only 30 s induces transient reductions in PV independently of posture change. The present findings suggest that PV changes due to sprint running should be routinely reported as well as the posture and the exact time in this posture.

  9. Volume analysis of heat-induced cracks in human molars: A preliminary study

    Directory of Open Access Journals (Sweden)

    Michael A. Sandholzer

    2014-01-01

    Full Text Available Context: Only a few methods have been published dealing with the visualization of heat-induced cracks inside bones and teeth. Aims : As a novel approach this study used nondestructive X-ray microtomography (micro-CT for volume analysis of heat-induced cracks to observe the reaction of human molars to various levels of thermal stress. Materials and Methods: Eighteen clinically extracted third molars were rehydrated and burned under controlled temperatures (400, 650, and 800°C using an electric furnace adjusted with a 25°C increase/min. The subsequent high-resolution scans (voxel-size 17.7 μm were made with a compact micro-CT scanner (SkyScan 1174. In total, 14 scans were automatically segmented with Definiens XD Developer 1.2 and three-dimensional (3D models were computed with Visage Imaging Amira 5.2.2. The results of the automated segmentation were analyzed with an analysis of variance (ANOVA and uncorrected post hoc least significant difference (LSD tests using Statistical Package for Social Sciences (SPSS 17. A probability level of P < 0.05 was used as an index of statistical significance. Results: A temperature-dependent increase of heat-induced cracks was observed between the three temperature groups (P < 0.05, ANOVA post hoc LSD. In addition, the distributions and shape of the heat-induced changes could be classified using the computed 3D models. Conclusion: The macroscopic heat-induced changes observed in this preliminary study correspond with previous observations of unrestored human teeth, yet the current observations also take into account the entire microscopic 3D expansions of heat-induced cracks within the dental hard tissues. Using the same experimental conditions proposed in the literature, this study confirms previous results, adds new observations, and offers new perspectives in the investigation of forensic evidence.

  10. Blood volume changes after radiotherapy of the CNS; Blutvolumenveraenderungen nach Strahlentherapie des zentralen Nervensystems

    Energy Technology Data Exchange (ETDEWEB)

    Wenz, F. [Radiologische Universitaetsklinik, Heidelberg (Germany); Fuss, M. [Radiologische Universitaetsklinik, Heidelberg (Germany); Scholdei, R. [Radiologische Universitaetsklinik, Heidelberg (Germany); Essig, M. [Abt. Onkologische Diagnostik und Therapie, Deutsches Krebsforschungszentrum, Heidelberg (Germany); Lohr, F. [Radiologische Universitaetsklinik, Heidelberg (Germany); Rempp, K. [Abt. Klinische Neuroradiologie, Univ. Heidelberg (Germany); Brix, G. [Abt. Biophysik und Medizinische Strahlenphysik, Deutsches Krebsforschungszentrum, Heidelberg (Germany); Knopp, M.V. [Abt. Onkologische Diagnostik und Therapie, Deutsches Krebsforschungszentrum, Heidelberg (Germany); Engenhart, R. [Radiologische Universitaetsklinik, Heidelberg (Germany); Wannenmacher, M. [Radiologische Universitaetsklinik, Heidelberg (Germany)

    1996-10-01

    The pathogenesis of late delayed radiation damage in normal brain tissue is most likely due to damage to the vascular endothelium. The mitotic activity of gliomas was shown to correlate with the tumor induced angiogenesis. Dynamic susceptibility contrast MR imaging (DSC MRI) allows the measurement of the cerebral hemodynamics based on the indicator dilution theory. We describe theory and technique of the method and present our experience with blood volume measurements after irradiation of the CNS. We established a double slice technique on a standard 1.5 T MR system without hardware modifications, which allows an absolute quantification of the blood volume in regions of interest (ROI) within the brain. Fifty-five T2* weighted double slice images were acquired before, during and after bolus injection of Gd-DTPA (0.1 mmol/kg in 5 sec.) using a SD FLASH sequence (simultaneous dual fast low angle shot, TR/TE1/TE2 31/16/25, flip angle 10 ). Concentration-time curves were calculated from the measured signal-time curves. Blood volume values in tissue were normalised and calculated in absolute values (ml/100 g) based on the knowledge of the arterial input function (AIF), which was measured in the brain supplying arteries. The whole procedure requires only 2 to 3 minutes, the time for post processing is about 15 to 20 minutes. Blood volume parameter images of representative cases demonstrate the blood volume changes after radiotherapy. A reduction in blood volume could be observed in normal brain tissue and low-grade gliomas, while recurrent tumors were accompanied by a local increase in blood volume. Radiation induced blood volume changes in the CNS can be measured using dynamic susceptibility contrast MR imaging. The measurements in normal brain tissue allow a functional in-vivo analysis of late delayed radiation reactions of the CNS. (orig.) [Deutsch] Die Pathogenese von Strahlenspaetfolgen am Gehirn wird auf eine Schaedigung der Gefaessendothelien zurueckgefuehrt. Die

  11. Implications of changing scattering properties on Greenland ice sheet volume change from Cryosat-2 altimetry

    DEFF Research Database (Denmark)

    Simonsen, Sebastian Bjerregaard; Sørensen, Louise Sandberg

    2017-01-01

    Long-term observations of surface elevation change of the Greenland ice sheet (GrIS) is of utmost importance when assessing the state of the ice sheet. Satellite radar altimetry offers a long time series of data over the GrIS, starting with ERS-1 in 1991. ESA's Cryosat-2 mission, launched in 2010...... waveform parameters to be applicable for correcting for changes in volume scattering. The best results in the Synthetic Aperture Radar Interferometric mode area of the GrIS are found when applying only the backscatter correction, whereas the best result in the Low Resolution Mode area is obtained by only...... applying a leading edge width correction. Using this approach to correct for the scattering properties, a volume loss of −292±38 km3 yr −1 is found for the GrIS for the time span November 2010 until November 2014. The inclusion of waveform parameter corrections and improved relocation for the GrIS, helps...

  12. Entropy and volume change of dissociation in tobacco mosaic virus probed by high pressure.

    Science.gov (United States)

    Bispo, Jose A C; Bonafe, Carlos F S; Joekes, Ines; Martinez, Ernesto A; Carvalho, Giovani B M; Norberto, Douglas R

    2012-12-27

    Virus dissociation and inactivation by high pressure have been extensively studied in recent decades. Pressure-induced dissociation of viral particles involves a reduction in the Gibbs free energy of dissociation and a negative change in volume. In this work, we investigated the combined effect of high pressure and temperature on the dissociation of tobacco mosaic virus (TMV). We assumed the presence of two states of TMV with different tendencies to dissociate. Thus one form presents a low tendency (L) and the other a high tendency (H) to dissociate. Based on the model described here, the L-H transition was favored by an increase in pressure and a decrease in temperature. The volume change of dissociation was pressure- and temperature-dependent, with a highly negative value of -80 mL/mol being recorded at 0 °C and atmospheric pressure. The entropy and enthalpy of dissociation were very temperature- and pressure-dependent, with values of entropy of 450 to -1300 kJ/mol and values of enthalpy of 5.5 × 10(4) to 2.4 × 10(4) kJ/mol. The dissociation of TMV was enthalpy-driven at all temperatures and pressures investigated. Based on these findings, we conclude that the model presented allows accurate predictions of viral dissociation behavior in different experimental conditions.

  13. Development of a finite element firn densification model for converting volume changes to mass changes

    CERN Document Server

    Cummings, Evan; Brinkerhoff, Douglas

    2013-01-01

    In regions where ice sheets are increasing in mass, there is a 50-200 m layer of old snow called firn which does not melt in the summer months. The density of firn tracks the transformation of snow into glacial ice at approximately 917 kg m^-3. The process of firn densification is important in at least two ways: 1) it can be a dominant component in the observed rate of change of the surface elevation, and 2) storage of liquid water in the lower density firn layer is now considered a critical component in the mass balance of ice sheets. If the rate of change of surface elevation can be equated with the rate of change in the mass of the ice sheet, we would have an excellent means of monitoring ice sheet mass balance. However, knowledge of firn densification rates is needed to make the inference of mass rate of change from volume rate of change. Several firn models have been created for areas without melt. We have reformulated these models with the finite-element software package FEniCS and integrated them with ...

  14. Epidural anesthesia, hypotension, and changes in intravascular volume

    DEFF Research Database (Denmark)

    Holte, Kathrine; Foss, Nicolai B; Svensén, Christer;

    2004-01-01

    BACKGROUND: The most common side effect of epidural or spinal anesthesia is hypotension with functional hypovolemia prompting fluid infusions or administration of vasopressors. Short-term studies (20 min) in patients undergoing lumbar epidural anesthesia suggest that plasma volume may increase wh...

  15. Osmotically induced cell swelling versus cell shrinking elicits specific changes in phospholipid signals in tobacco pollen tubes

    NARCIS (Netherlands)

    L.E. Zonia; T. Munnik

    2004-01-01

    Pollen tube cell volume changes rapidly in response to perturbation of the extracellular osmotic potential. This report shows that specific phospholipid signals are differentially stimulated or attenuated during osmotic perturbations. Hypo-osmotic stress induces rapid increases in phosphatidic acid

  16. Early changes in left atrial volume after acute myocardial infarction. Relation to invasive hemodynamics at rest and during exercise

    DEFF Research Database (Denmark)

    Bakkestrøm, Rine; Andersen, Mads J; Ersbøll, Mads

    2016-01-01

    BACKGROUND: Dilatation of left atrium (LA) reflects chronic LA pressure or volume overload that possesses considerable prognostic information. Little is known regarding the interaction between LA remodeling after acute myocardial infarction (MI) and left atrial pressure at rest and during exercise...... associated with resting and exercise induced changes in LA pressure overload. The dilatation was however associated with lower e' and higher MR-proANP....

  17. Change in heart rate variability following orthostasis relates to volume of exercise in healthy women.

    Science.gov (United States)

    Gilder, Michael; Ramsbottom, Roger

    2008-12-05

    Physically active individuals demonstrate increased heart rate variability (HRV) during rest compared to sedentary individuals, but the impact of different volumes of regular exercise on the HRV response to postural change is not well understood. This study investigates change in HRV following orthostasis in seventy-two young women who exercise at low (LV) or high (HV) volumes of physical activity. Supine and standing R-R intervals were analysed by time domain, frequency domain and Poincaré plot methods. All methods revealed greater change in the vagal response in the HV group, indicating that HRV following postural change is modulated by volume of exercise.

  18. Orthostatic leg blood volume changes assessed by near-infrared spectroscopy

    DEFF Research Database (Denmark)

    Truijen, J; Kim, Y S; Krediet, C T P

    2012-01-01

    posture, volume accumulation in small blood vessels contributes significantly to the total fluid volume accumulated in the legs. Considering that near-infrared spectroscopy (NIRS) tracks postural blood volume changes within the small blood vessels of the lower leg, we evaluated the NIRS-determined changes...... separate days (n = 8). In response to HUT, an initially fast increase in [O(2)Hb] was followed by a gradual decline, while [HHb] increased continuously. The increase in [tHb] during HUT was closely related to the increase in total leg volume (r(2) = 0.95 ± 0.03). After tilt back, [O(2)Hb] declined below...

  19. Epidural anesthesia, hypotension, and changes in intravascular volume

    DEFF Research Database (Denmark)

    Holte, Kathrine; Foss, Nicolai B; Svensén, Christer

    2004-01-01

    hypotension is present, which may have implications for the choice of treatment of hypotension. However, no long-term information or measurements of plasma volumes with or without hypotension after epidural anesthesia are available. METHODS: In 12 healthy volunteers, the authors assessed plasma (125I...... and ephedrine has similar hemodynamic effects, the latter may be preferred in patients with cardiopulmonary diseases in which perioperative fluid overload is undesirable....

  20. Age-related changes in intracranial compartment volumes in normal adults assessed by magnetic resonance imaging.

    Science.gov (United States)

    Matsumae, M; Kikinis, R; Mórocz, I A; Lorenzo, A V; Sándor, T; Albert, M S; Black, P M; Jolesz, F A

    1996-06-01

    Magnetic resonance (MR) image-based computerized segmentation was used to measure various intracranial compartments in 49 normal volunteers ranging in age from 24 to 80 years to determine age-related changes in brain, ventricular, and extraventricular cerebrospinal fluid (CSF) volumes. The total intracranial volume (sum of brain, ventricular, and extraventricular CSF) averaged 1469 +/- 102 cm3 in men and 1289 +/- 111 cm3 in women. The difference was attributable primarily to brain volume, which accounted for 88.6% of the respective intracranial volumes in both sexes, but was significantly larger in men (1302 +/- 112 cm3) than in women (1143 +/- 105 cm3). In both, the cranial CSF volume averaged 11.4%. Total intracranial volume did not change with age, although the normalized brain volume of both men and women began to decrease after the age of 40 years. This decrease was best reflected by expansion of the extraventricular CSF volume which, after the age of 50 years, was more marked in men than in women. The volume of the cranial CSF, as determined by MR image-based computerized segmentation, is considerably larger than traditionally accepted and resides mostly extraventricularly. Expansion of CSF volume with age provides a good index of brain shrinkage although evolving changes and growth of the head with age tend to confound the results.

  1. Rotigaptide (ZP123) improves atrial conduction slowing in chronic volume overload-induced dilated atria.

    Science.gov (United States)

    Haugan, Ketil; Miyamoto, Takuya; Takeishi, Yasuchika; Kubota, Isao; Nakayama, Jun; Shimojo, Hisashi; Hirose, Masamichi

    2006-07-01

    Chronic atrial dilation is associated with atrial conduction velocity slowing and an increased risk of developing atrial tachyarrhythmias. Rotigaptide (ZP123) is a selective gap junction modifier that increases cardiac gap junctional intercellular communication. We hypothesised that rotigaptide treatment would increase atrial conduction velocity and reduce the inducibility to atrial tachyarrhythmias in a model of chronic volume overload induced chronic atrial dilatation characterized by atrial conduction velocity slowing. Chronic volume overload was created in Japanese white rabbits by arterio-venous shunt formation. Atrial conduction velocity and atrial tachyarrhythmias inducibility were examined in Langendorff-perfused chronic volume overload hearts (n=12) using high-resolution optical mapping before and after treatment with rotigaptide. Moreover, expression levels of atrial gap junction proteins (connexin40 and connexin43) were examined in chronic volume overload hearts (n=6) and compared to sham-operated controls (n=6). Rotigaptide treatment significantly increased atrial conduction velocity in chronic volume overload hearts, however, rotigaptide did not decrease susceptibility to the induction of atrial tachyarrhythmias. Protein expressions of Cx40 and Cx43 were decreased by 32% and 72% (P<0.01), respectively, in chromic volume overload atria compared to control. To conclude, rotigaptide increased atrial conduction velocity in a rabbit model of chromic volume overload induced atrial conduction velocity slowing. The demonstrated effect of rotigaptide on atrial conduction velocity did not prevent atrial tachyarrhythmias inducibility. Whether rotigaptide may possess antiarrhythmic efficacy in other models of atrial fibrillation remains to be determined.

  2. Human choice and climate change. Volume 2: Resources and technology

    Energy Technology Data Exchange (ETDEWEB)

    Rayner, S.; Malone, E.L.

    1997-12-31

    Foreward: Preface; Introduction; The natural science of global climate change; Land and water use; Coastal zones and oceans; Energy and industry; Energy and social systems; Technological change; and Sponsoring organizations, International Advisory Board, and project participants.

  3. Cell volume changes affect gluconeogenesis in the perfused liver of the catfish Clarias batrachus

    Indian Academy of Sciences (India)

    Carina Goswami; Shritapa Datta; Kuheli Biswas; Nirmalendu Saha

    2004-09-01

    In addition to lactate and pyruvate, some amino acids were found to serve as potential gluconeogenic substrates in the perfused liver of Clarias batrachus. Glutamate was found to be the most effective substrate, followed by lactate, pyruvate, serine, ornithine, proline, glutamine, glycine, and aspartate. Four gluconeogenic enzymes, namely phosphoenolpyruvate carboxykinase (PEPCK), pyruvate carboxylase (PC), fructose 1,6-bisphosphatase (FBPase) and glucose 6-phosphatase (G6Pase) could be detected mainly in liver and kidney, suggesting that the latter are the two major organs responsible for gluconeogenic activity in this fish. Hypo-osmotically induced cell swelling caused a significant decrease of gluconeogenic efflux accompanied with significant decrease of activities of PEPCK, FBPase and G6Pase enzymes in the perfused liver. Opposing effects were seen in response to hyper-osmotically induced cell shrinkage. These changes were partly blocked in the presence of cycloheximide, suggesting that the aniso-osmotic regulations of gluconeogenesis possibly occurs through an inverse regulation of enzyme proteins and/or a regulatory protein synthesis in this catfish. In conclusion, gluconeogenesis appears to play a vital role in C. batrachus in maintaining glucose homeostasis, which is influenced by cell volume changes possibly for proper energy supply under osmotic stress.

  4. Drug-induced hair colour changes.

    Science.gov (United States)

    Ricci, Francesco; De Simone, Clara; Del Regno, Laura; Peris, Ketty

    2016-12-01

    Hair colour modifications comprise lightening/greying, darkening, or even a complete hair colour change, which may involve the scalp and/or all body hair. Systemic medications may cause hair loss or hypertrichosis, while hair colour change is an uncommon adverse effect. The rapidly increasing use of new target therapies will make the observation of these side effects more frequent. A clear relationship between drug intake and hair colour modification may be difficult to demonstrate and the underlying mechanisms of hair changes are often unknown. To assess whether a side effect is determined by a specific drug, different algorithms or scores (e.g. Naranjo, Karch, Kramer, and Begaud) have been developed. The knowledge of previous similar reports on drug reactions is a key point of most algorithms, therefore all adverse events should be recognised and reported to the scientific community. Furthermore, even if hair colour change is not a life-threatening side effect, it is of deep concern for patient's quality of life and adherence to treatment. We performed a review of the literature on systemic drugs which may induce changes in hair colour.

  5. Climatic impact of aircraft induced ozone changes

    Energy Technology Data Exchange (ETDEWEB)

    Sausen, R.; Feneberg, B.; Ponater, M. [Deutsche Forschungs- und Versuchsanstalt fuer Luft- und Raumfahrt e.V., Oberpfaffenhofen (Germany). Inst. fuer Physik der Atmosphaere

    1997-12-31

    The effect of aircraft induced ozone changes on the global climate is studied by means of the general circulation model ECHAM4. The zonal mean temperature signal is considered. In order to estimate the statistical significance of the climatic impact a multivariate statistical test hierarchy combined with the fingerprint method has been applied. Sensitivity experiments show a significant coherent temperature response pattern in the northern extra-tropics for mid-latitude summer conditions. It consists of a tropospheric warming of about 0.2 K with a corresponding stratospheric cooling of the same magnitude. (author) 16 refs.

  6. Trait positive affect is associated with hippocampal volume and change in caudate volume across adolescence.

    Science.gov (United States)

    Dennison, Meg; Whittle, Sarah; Yücel, Murat; Byrne, Michelle L; Schwartz, Orli; Simmons, Julian G; Allen, Nicholas B

    2015-03-01

    Trait positive affect (PA) in childhood confers both risk and resilience to psychological and behavioral difficulties in adolescence, although explanations for this association are lacking. Neurodevelopment in key areas associated with positive affect is ongoing throughout adolescence, and is likely to be related to the increased incidence of disorders of positive affect during this period of development. The aim of this study was to prospectively explore the relationship between trait indices of PA and brain development in subcortical reward regions during early to mid-adolescence in a community sample of adolescents. A total of 89 (46 male, 43 female) adolescents participated in magnetic resonance imaging assessments during both early and mid-adolescence (mean age at baseline = 12.6 years, SD = 0.45; mean follow-up period = 3.78 years, SD = 0.21) and also completed self-report measures of trait positive and negative affect (at baseline). To examine the specificity of these effects, the relation between negative affect and brain development was also examined. The degree of volume reduction in the right caudate over time was predicted by PA. Independent of time, larger hippocampal volumes were associated with higher PA, and negative affect was associated with smaller left amygdala volume. The moderating effect of negative affect on the development of the left caudate varied as a function of lifetime psychiatric history. These findings suggest that early to mid-adolescence is an important period whereby neurodevelopmental processes may underlie key phenotypes conferring both risk and resilience for emotional and behavioral difficulties later in life.

  7. Ionic changes during experimentally induced seizure activity.

    Science.gov (United States)

    Lux, H D; Heinemann, U

    1978-01-01

    Changes in intra- and extracellular ionic activity and their relation to generation and termination of seizure phenomena can be studied with the help of ion-selective microelectrodes. Transient changes in extracellular potassium activity (aK) of the cortex regularly accompany paroxysmal activity induced by electrical stimulation and pentylenetetrazol injections or occur within active penicillin and aluminum foci. A rise of aK from baseline levels of about 3 mmoles/l up to ceiling levels of 8--12 mmoles/l, followed by subnormal K activity, is typically found during seizure discharge. Extracellular K accumulation during seizures facilitates the spread into extrafocal regions. Ceiling levels of extracellular aK are characterized by pronounced K reabsorption which is probably a limiting mechanism for the rise in extracellular aK. It may be a consequence of a simultaneous rise in intracellular Na activity that an electrogenic Na--K exchange process is involved in the termination of ictal activity. Seizures are also accompanied by significant reductions in extracellular Ca2+ activity (aCa) to as low as 0.7 mmoles/l (resting aCa 1.25 mmoles/l). There is no critical level of lowered aCa at which a seizure ultimately results. However, unlike changes in aK reductions in aCa can precede ictal activity. Thus, a fall of aCa occurs before the onset of paroxysmal periods during cyclical spike driving in a penicillin focus and before seizures induced by pentylenetetrazol. Ca2+-dependent mechanisms may contribute to seizure generation. In addition to changes in aK and aCa, intracellular chloride activity (aCl) can increase during seizure activity, as a result of an impaired chloride extrusion mechanism, which would lead to a reduced efficacy of inhibitory synaptic transmission and, therefore, to facilitation of seizure generation.

  8. Cellular Automaton Simulation For Volume Changes Of Solidifying Nodular Cast Iron

    Directory of Open Access Journals (Sweden)

    Burbelko A.

    2015-09-01

    Full Text Available Volume changes of the binary Fe-C alloy with nodular graphite were forecast by means of the Cellular Automaton Finite Differences (CA-FD model of solidification. Simulations were performed in 2D space for differing carbon content. Dependences of phase density on temperature were considered in the computations; additionally density of the liquid phase and austenite were deemed as a function of carbon concentration. Changes of the specific volume were forecast on the base of the phase volume fractions and changes of phase density. Density of modeled material was calculated as weighted average of densities of each phase.

  9. How do sock ply changes affect residual-limb fluid volume in people with transtibial amputation?

    Directory of Open Access Journals (Sweden)

    Joan E. Sanders, PhD

    2012-04-01

    Full Text Available The purpose of this research was to investigate the influence of sock addition and removal on residual-limb fluid volume in people using prosthetic limbs. We used bioimpedance analysis to measure residual-limb extracellular fluid volume on 28 transtibial amputee subjects during 30 min test sessions. Upon addition of a one-ply polyester sock, residual-limb fluid volume changes ranged from −4.0% to 0.8% (mean −0.9 +/− 1.3% of the initial limb fluid volume. Changes for sock removal ranged from −1.2% to 2.8% (mean 0.5 +/− 0.8%. Subjects who reduced in fluid volume with both addition and removal of a sock and subjects with high positive ratios between the fluid-volume loss upon sock addition and gain upon sock removal (high add/remove [AR] ratios tended to have arterial disease, were obese, and were smokers. Subjects with low positive AR ratios, subjects who increased in fluid volume both with sock addition and removal, and a single subject who increased in fluid volume with sock addition and decreased with sock removal tended to be nonsmokers and either individuals in good health without complications or individuals without arterial problems. Results are relevant for the anticipation of limb volume changes during prosthetic fitting and toward the design of adjustable-socket technologies.

  10. Cocaine-induced pulmonary changes: HRCT findings

    Directory of Open Access Journals (Sweden)

    Renata Rocha de Almeida

    2015-08-01

    Full Text Available AbstractObjective: To evaluate HRCT scans of the chest in 22 patients with cocaine-induced pulmonary disease.Methods: We included patients between 19 and 52 years of age. The HRCT scans were evaluated by two radiologists independently, discordant results being resolved by consensus. The inclusion criterion was an HRCT scan showing abnormalities that were temporally related to cocaine use, with no other apparent causal factors.Results:In 8 patients (36.4%, the clinical and tomographic findings were consistent with "crack lung", those cases being studied separately. The major HRCT findings in that subgroup of patients included ground-glass opacities, in 100% of the cases; consolidations, in 50%; and the halo sign, in 25%. In 12.5% of the cases, smooth septal thickening, paraseptal emphysema, centrilobular nodules, and the tree-in-bud pattern were identified. Among the remaining 14 patients (63.6%, barotrauma was identified in 3 cases, presenting as pneumomediastinum, pneumothorax, and hemopneumothorax, respectively. Talcosis, characterized as perihilar conglomerate masses, architectural distortion, and emphysema, was diagnosed in 3 patients. Other patterns were found less frequently: organizing pneumonia and bullous emphysema, in 2 patients each; and pulmonary infarction, septic embolism, eosinophilic pneumonia, and cardiogenic pulmonary edema, in 1 patient each.Conclusions: Pulmonary changes induced by cocaine use are varied and nonspecific. The diagnostic suspicion of cocaine-induced pulmonary disease depends, in most of the cases, on a careful drawing of correlations between clinical and radiological findings.

  11. Cocaine-induced pulmonary changes: HRCT findings *

    Science.gov (United States)

    de Almeida, Renata Rocha; Zanetti, Gláucia; Souza, Arthur Soares; de Souza, Luciana Soares; Silva, Jorge Luiz Pereira e; Escuissato, Dante Luiz; Irion, Klaus Loureiro; Mançano, Alexandre Dias; Nobre, Luiz Felipe; Hochhegger, Bruno; Marchiori, Edson

    2015-01-01

    Abstract Objective: To evaluate HRCT scans of the chest in 22 patients with cocaine-induced pulmonary disease. Methods: We included patients between 19 and 52 years of age. The HRCT scans were evaluated by two radiologists independently, discordant results being resolved by consensus. The inclusion criterion was an HRCT scan showing abnormalities that were temporally related to cocaine use, with no other apparent causal factors. Results: In 8 patients (36.4%), the clinical and tomographic findings were consistent with "crack lung", those cases being studied separately. The major HRCT findings in that subgroup of patients included ground-glass opacities, in 100% of the cases; consolidations, in 50%; and the halo sign, in 25%. In 12.5% of the cases, smooth septal thickening, paraseptal emphysema, centrilobular nodules, and the tree-in-bud pattern were identified. Among the remaining 14 patients (63.6%), barotrauma was identified in 3 cases, presenting as pneumomediastinum, pneumothorax, and hemopneumothorax, respectively. Talcosis, characterized as perihilar conglomerate masses, architectural distortion, and emphysema, was diagnosed in 3 patients. Other patterns were found less frequently: organizing pneumonia and bullous emphysema, in 2 patients each; and pulmonary infarction, septic embolism, eosinophilic pneumonia, and cardiogenic pulmonary edema, in 1 patient each. Conclusions: Pulmonary changes induced by cocaine use are varied and nonspecific. The diagnostic suspicion of cocaine-induced pulmonary disease depends, in most of the cases, on a careful drawing of correlations between clinical and radiological findings. PMID:26398752

  12. Cocaine-induced pulmonary changes: HRCT findings

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Renata Rocha de; Zanetti, Glaucia; Marchiori, Edson, E-mail: edmarchiori@gmail.com [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Programa de Pos-Graduacao em Radiologia; Souza Junior, Arthur Soares [Faculdade de Medicina de Petropolis, Petropolis, RJ (Brazil); Souza, Luciana Soares de [Ultra-X, Sao Jose do Rio Preto, SP (Brazil); Silva, Jorge Luiz Pereira e [Universidade Federal da Bahia (UFBA), Salvador (Brazil). Dep. de Medicina e Apoio Diagnostico; Escuissato, Dante Luiz [Universidade Federal do Parana (UFPR), Curitiba (Brazil). Dept. de Clinica Medica; Irion, Klaus Loureiro [Liverpool Heart and Chest Hospital NHS Foundation Trust, Liverpool (United Kingdom); Mancano, Alexandre Dias [Hospital Anchieta, Taguatinga, DF (Brazil); Nobre, Luiz Felipe [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil); Hochhegger, Bruno [Universidade Federal de Ciencias da Saude de Porto Alegre, Porto Alegre, RS (Brazil); Marchiori, Edson [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil)

    2015-07-15

    Objective: To evaluate HRCT scans of the chest in 22 patients with cocaine-induced pulmonary disease. Methods: We included patients between 19 and 52 years of age. The HRCT scans were evaluated by two radiologists independently, discordant results being resolved by consensus. The inclusion criterion was an HRCT scan showing abnormalities that were temporally related to cocaine use, with no other apparent causal factors. Results: In 8 patients (36.4%), the clinical and tomographic findings were consistent with 'crack lung', those cases being studied separately. The major HRCT findings in that subgroup of patients included ground-glass opacities, in 100% of the cases; consolidations, in 50%; and the halo sign, in 25%. In 12.5% of the cases, smooth septal thickening, paraseptal emphysema, centrilobular nodules, and the tree-in-bud pattern were identified. Among the remaining 14 patients (63.6%), barotrauma was identified in 3 cases, presenting as pneumomediastinum, pneumothorax, and hemopneumothorax, respectively. Talcosis, characterized as perihilar conglomerate masses, architectural distortion, and emphysema, was diagnosed in 3 patients. Other patterns were found less frequently: organizing pneumonia and bullous emphysema, in 2 patients each; and pulmonary infarction, septic embolism, eosinophilic pneumonia, and cardiogenic pulmonary edema, in 1 patient each. Conclusions: Pulmonary changes induced by cocaine use are varied and nonspecific. The diagnostic suspicion of cocaine-induced pulmonary disease depends, in most of the cases, on a careful drawing of correlations between clinical and radiological findings. (author)

  13. Changes in down dead wood volume across a chronosequence of silvicultural openings in southern Indiana forests

    Science.gov (United States)

    Michael A. Jenkins; George R. Parker

    1997-01-01

    The volume and decay stages of down dead wood were evaluated across a chronosequence of 46 silvicultural openings and 10 uncut control stands to determine how down dead wood volume changes with stand development. Openings ranged in age from 8 to 26 years and were divided into three age groups: (1) 16 years. Individual logs...

  14. Study of the seroma volume changes in the patients who underwent Accelerated Partial Breast Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dae Ho; Son, Sang Jun; Mun, Jun Ki; Seo, Seok Jin; Lee, Je Hee [Dept. of Radiation Oncology, Seoul National University Hospital, Seoul (Korea, Republic of)

    2016-06-15

    By analyzing seroma volume changes in the patients who underwent Partial breast radiation therapy after breast conserving surgery, we try to contribute to the improvement of radiotherapy effect. Enrolled 20 patients who underwent partial breast radiation therapy by ViewRay MRIdian System were subject. After seeking for the size of the removed sample in the patients during surgery and obtained seroma volume changes on a weekly basis. On the Basis of acquired volume, it was compared with age, term from start of the first treatment after surgery, BMI (body mass index) and the extracted sample size during surgery. And using the ViewRay MRIdian RTP System, the figure was analyzed by PTV(=seroma volume + margin) to obtain a specific volume of the Partial breast radiation therapy. The changes of seroma volume from MR simulation to the first treatment (a week) is 0~5% in 8, 5~10% in 3, 10 to 15% in 2, and 20% or more in 5 people. Two patients(A, B patient) among subjects showed the biggest change. The A patient's 100% of the prescribed dose volume is 213.08 cc, PTV is 181.93 cc, seroma volume is 15.3 cc in initial plan. However, while seroma volume decreased 65.36% to 5.3 cc, 100% of the prescribed dose volume was reduced to 3.4% to 102.43 cc and PTV also did 43.6% to 102.54 cc. In the case of the B patient, seroma volume decreased 42.57% from 20.2 cc to 11.6 cc. Because of that, 100% of the prescribed dose volume decreased 8.1% and PTV also did to 40%. As the period between the first therapy and surgery is shorter, the patient is elder and the size of sample is smaller than 100 cc, the change grow bigger. It is desirable to establish an adaptive plan according to each patient's changes of seroma volume through continuous observation. Because partial breast patients is more sensitive than WBRT patients about dose conformity in accordance with the volume change.

  15. Can serpentinization induce fracturing? Fluid pathway development and the volume increase enigma

    Science.gov (United States)

    Plümper, Oliver; Jamtveit, Bjørn; Røyne, Anja

    2013-04-01

    focused on this topic so far. Here, we investigate the feasibility of reaction-induced fracturing and pore space evolution during serpentinization by combining microstructural investigations using scanning/transmission electron microscopy and synchrotron micro-tomography of natural samples with theoretical considerations on the forces exerted during solid volume increasing reactions. We particularly focus on the interface-scale mechanism of reaction-induced fracturing (Plümper et al. 2012) and the establishment of microstructural markers (e.g., inert exsolutions in olivine) to identify volume changes and estimate crystallization pressures (Kelemen and Hirth 2012). Our investigations suggest that reaction-induced fracturing during serpentinization is possible and during certain physico-chemical circumstances a positive feedback to alter vast amounts of originally impermeable rock is established. Plümper O., Røyne A., Magraso A., Jamtveit B. (2012) The interface-scale mechanism of reaction-induced fracturing during serpentinization. Geology. 40, 1103-1106. Kelemen, P. B. & Hirth, G. (2012) Reaction-driven cracking during retrograde metamorphism: Olivine hydration and carbonation. Earth and Planetary Science Letters 345, 81-89.

  16. SPLENIC VOLUME CHANGE AND THERAPUETIC RESPONSE IN PATIENTS TREATED WITH RADIOMMUNOCONJUGATES

    Energy Technology Data Exchange (ETDEWEB)

    Shen, S; DeNardo, G L; Yuan, A; Siantar, C H; O' Donnell, R T; DeNardo, S J

    2005-04-06

    Splenomegaly is frequently found in non-Hodgkin's lymphoma (NHL) patients. This study evaluated the implications of splenic volume change in response to radioimmunotherapy (RIT). Twenty-nine NHL patients treated with radiolabeled-Lym-1 and 9 breast cancer patients (reference group) treated with radiolabeled-ChL6, BrE-3 or m170 were analyzed using CT splenic images obtained before and after RIT. Patient-specific radiation doses to spleen were determined using actual splenic volume determined by CT and body weight. In 13 of 29 NHL patients who had splenic volume {le} 310 ml, there was no or small change (-23 to 15 mL) in splenic volume, despite splenic doses as high as 14.4 Gy. Similarly, in a reference group of 9 breast cancer patients, there was no or small change (-5 to 13 mL), despite splenic doses as high as 11.4 Gy. In contrast, 13 of 29 NHL patients who had splenic volume 380-1400 mL, splenic volume decreased by 68 to 548 mL despite splenic doses as low as 1.40 Gy. Ten of 29 NHL patients with greater than a 15% decrease in splenic volume after RIT had nodal tumor regression (5 CR, 5 PR). In the remaining 19 NHL patients with less than a 15% decrease in splenic volume after RIT, there were 7 non-responders (5 CR and 7 PR). Splenic volume changes were found in NHL patients with splenomegaly. These splenic volume changes is likely due to therapeutic effect on malignant lymphocytes associated with splenomegaly. Nodal tumor response was more likely when splenomegaly decreased after RIT.

  17. Retinal changes in pregnancy-induced hypertension

    Directory of Open Access Journals (Sweden)

    Akash Pankaj Shah

    2015-01-01

    Full Text Available Aims: The aim was to determine the prevalence of retinal changes in pregnancy-induced hypertension (PIH and any association between the retinal changes and age, parity, blood pressure, proteinuria, and severity of the disease. Settings and Design: Hospital-based cross-sectional study. Materials and Methods: All the patients admitted with a diagnosis of PIH were included in this study. Age, gravida, gestation period, blood pressure, and proteinuria were noted from the case records. Fundus examination was done with a direct ophthalmoscope. The findings were noted and were analyzed using SPSS program. Results: A total of 150 patients of PIH were examined. The mean age of patients was 25.1 years. The gestation period ranged from 27 weeks to 42 weeks; 76 (50.67% were the primi gravida. 92 (61.33% patients had gestational hypertension, 49 (32.67% patients had preeclampsia, and 9 (6% had eclampsia. Retinal changes (hypertensive retinopathy were noted in 18 (12% patients - Grade 1 in 12 (8% and Grade 2 in 6 (4%. Hemorrhages or exudates or retinal detachment were not seen in any patient. There was statistically significant positive association of retinal changes and blood pressure (P = 0.037, proteinuria (P = 0.0005, and severity of the PIH (P = 0.004. Conclusions: Retinal changes were seen in 12% of patients with PIH. Occurrence of hypertensive retinopathy in PIH cases has been decreased due to better antenatal care and early detection and treatment of PIH cases. There is a greater chance of developing retinopathy with increase in blood pressure, severity of PIH, and proteinuria in cases of PIH.

  18. Yield stress, volume change, and shear strength behaviour of unsaturated soils: validation of the SFG model

    National Research Council Canada - National Science Library

    Zhou, Annan; Sheng, Daichao

    2009-01-01

    The model recently presented by Sheng, Fredlund, and Gens, known as the SFG model, provides a consistent explanation of yield stress, shear strength, and volume change behaviour of unsaturated soils...

  19. Hydrogenation-induced microstructure changes in titanium

    Energy Technology Data Exchange (ETDEWEB)

    Laptev, R., E-mail: laptevrs@tpu.ru; Lider, A., E-mail: lider@tpu.ru; Bordulev, Yu., E-mail: bus@tpu.ru; Kudiiarov, V., E-mail: kudiyarov@tpu.ru; Garanin, G., E-mail: garaningv@tpu.ru

    2015-10-05

    Highlights: • Hydrogen induced microstructure changes in Ti studied by PL and DB spectroscopies. • Vacancies and vacancy clusters formed at concentration from 1.31 to 2.27 at.%. • Cluster-hydrogen and vacancy-hydrogen complexes formed at concentration up to 32 at.%. - Abstract: Microstructure changes of commercially pure titanium in a wide range of hydrogen concentrations from 0.8 at.% to 32.0 at.% were studied by means of positron lifetime spectroscopy and Doppler broadening spectroscopy. We have obtained new experimental data on the evolution of positron annihilation parameters τ{sub f}, τ{sub d} and their corresponding intensities I{sub f}, I{sub d,} as well as relative changes of parameters S/S{sub 0} and W/W{sub 0} depending on the hydrogen concentration in commercially pure titanium after gas-phase hydrogenation at 873 K. Results suggest that the hydrogenation of Ti samples up to concentrations of 1.31–2.27 at.% and subsequent cooling to a room temperature leads to the formation of vacancies and vacancy clusters. Further increase of the hydrogen concentration up to 32.0 at.% leads to the interaction of hydrogen with these defects and the formation of “cluster-hydrogen” and “vacancy-hydrogen” complexes.

  20. Extended free-volume defects in chalcogenide glassy semiconductors induced by high-energy {gamma}-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Balitska, Valentina [Lviv Institute of Materials of SRC (Ukraine); State University of Vital Activity Safety, Lviv 79007 (Ukraine); Filipecki, Jacek; Shpotyuk, Oleh [Institute of Physics, Jan Dlugosz University, Czestochowa (Poland)

    2009-08-15

    It was shown that under-coordinated topological defects induced by high-energy {gamma}-irradiation can be a reason for significant changes in positron annihilation lifetime spectra of multicomponent chalcogenide glassy semiconductors within ternary Ge-As(Sb)-S systems. In the case of negatively-charged sulphur and arsenic atoms, the excess of free volume is quite enough to produce additional input in the second defect-related channel of positron trapping, while under-coordinated germanium atoms are practically non-detectable with this technique because of low associated free volume. Despite radiation-induced densification, the average positron lifetime demonstrate both growing and decaying tendencies after {gamma}-irradiation depending on glass composition. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  1. Cold-induced changes in amphibian oocytes

    Energy Technology Data Exchange (ETDEWEB)

    Angelier, N.; Moreau, N.A.; N' Da, E.A.; Lautredou, N.F. (Centre de Biologie Cellulaire, Ivry-sur-Seine (France))

    1989-08-01

    Female Pleurodeles waltl newts (Amphibia, urodele), usually raised at 20 degrees C, were submitted to low temperatures; oocytes responded to this cold stress by drastic changes both in lampbrush chromosome structure and in protein pattern. Preexisting lateral loops of lampbrush chromosomes were reduced in size and number, while cold-induced loops which were tremendously developed, occurred on defined bivalents of the oocyte at constant, reproducible sites. A comparison of protein patterns in control and stressed oocytes showed two main differences: in stressed oocytes, overall protein synthesis was reduced, except for a set of polypeptides, the cold-stress proteins; second, there was a striking inversion of the relative amount of beta- and gamma-actin found in the oocyte nucleus before and after cold stress. Whereas beta-actin was the predominant form in control oocytes, gamma-actin became the major form in stressed oocytes.

  2. Depression may be associated with hippocampal volume changes ...

    African Journals Online (AJOL)

    Adele

    ment score equal to 1.7 Psychosocial functioning is now regarded as a important ... adequate treatment to full remission carries considerable risks not only for the ... It may also lead to or exacerbate structural brain changes in depression, most particu- .... toxicity and decreased levels of BDNF with neuronal atrophy in the.

  3. Age-dependent changes in mitochondrial morphology and volume are not predictors of lifespan.

    Science.gov (United States)

    Regmi, Saroj G; Rolland, Stéphane G; Conradt, Barbara

    2014-02-01

    Mitochondrial dysfunction is a hallmark of skeletal muscle degeneration during aging. One mechanism through which mitochondrial dysfunction can be caused is through changes in mitochondrial morphology. To determine the role of mitochondrial morphology changes in age-dependent mitochondrial dysfunction, we studied mitochondrial morphology in body wall muscles of the nematodeC. elegans. We found that in this tissue, animals display a tubular mitochondrial network, which fragments with increasing age. This fragmentation is accompanied by a decrease in mitochondrial volume. Mitochondrial fragmentation and volume loss occur faster under conditions that shorten lifespan and occur slower under conditions that increase lifespan. However, neither mitochondrial morphology nor mitochondrial volume of five- and seven-day old wild-type animals can be used to predict individual lifespan. Our results indicate that while mitochondria in body wall muscles undergo age-dependent fragmentation and a loss in volume, these changes are not the cause of aging but rather a consequence of the aging process.

  4. Haemodynamic changes in insulin-induced hypoglycaemia in normal man

    DEFF Research Database (Denmark)

    Hilsted, J; Bonde-Petersen, F; Nørgaard, M B;

    1984-01-01

    ). The early rise in cardiac output was primarily due to an increase in heart rate, but later mainly due to increased stroke volume. Since pulmonary tissue volume was constant, the observed changes in cardiac output are unlikely to be due to a Frank-Starling mechanism but rather to increased sympatho...

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

    Science.gov (United States)

    Van Beaumont, W.

    1973-01-01

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

  6. Do Acartia tonsa (Dana) eggs regulate their volume and osmolality as salinity changes?

    DEFF Research Database (Denmark)

    Hansen, Benni Winding; Drillet, Guillaume; Pedersen, Morten Foldager;

    2012-01-01

    Subitaneous eggs from an euryhaline calanoid copepod Acartia tonsa were challenged by changes in salinity within the range from full strength salinity, down to zero and up to >70 psu. Egg volume changed immediately, increasing from 2.8 × 105 μm3 at full strength salinity (35 psu) to 3.8 × 105 μm3...... at 0 psu and back to its initial volume when gradually being returned to full strength salinity. Egg osmolality followed the molality of the surrounding water when challenged within a salinity range from 2 to 50 psu. Egg respiration was not affected when eggs kept at 35 psu was exposed to low salinity...... (2 psu). These results suggest that eggs are unable to regulate their volume or osmolality when challenged with changes in salinity. Gradual changes in salinity from 35 to 2 psu and back did not harm the eggs (embryos), since the hatching success remained unaffected by such changes in salinity...

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

    Science.gov (United States)

    Van Beaumont, W.

    1973-01-01

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

  8. Disodium cromoglycate attenuates hypoxia induced enlargement of end-expiratory lung volume in rats.

    Science.gov (United States)

    Maxová, H; Hezinová, A; Vízek, M

    2011-01-01

    Mechanism responsible for the enlargement of end-expiratory lung volume (EELV) induced by chronic hypoxia remains unclear. The fact that the increase in EELV persists after return to normoxia suggests involvement of morphological changes. Because hypoxia has been also shown to activate lung mast cells, we speculated that they could play in the mechanism increasing EELV similar role as in vessel remodeling in hypoxic pulmonary hypertension (HPH). We, therefore, tested an effect of mast cells degranulation blocker disodium cromoglycate (DSCG) on hypoxia induced EELV enlargement. Ventilatory parameters, EELV and right to left heart weight ratio (RV/LV+S) were measured in male Wistar rats. The experimental group (H+DSCG) was exposed to 3 weeks of normobaric hypoxia and treated with DSCG during the first four days of hypoxia, control group was exposed to hypoxia only (H), two others were kept in normoxia as non-treated (N) and treated (N+DSCG) groups. DSCG treatment significantly attenuated the EELV enlargement (H+DSCG = 6.1+/-0.8; H = 9.2+/-0.9; ml +/-SE) together with the increase in minute ventilation (H + DSCG = 190+/-8; H = 273 +/- 10; ml/min +/- SE) and RV/LV + S (H + DSCG = 0.39 +/- 0.03; H = 0.50 +/- 0.06).

  9. Thrombus Volume Change Visualization after Endovascular Abdominal Aortic Aneurysm Repair

    Science.gov (United States)

    Maiora, Josu; García, Guillermo; Macía, Iván; Legarreta, Jon Haitz; Boto, Fernando; Paloc, Céline; Graña, Manuel; Abuín, Javier Sanchez

    A surgical technique currently used in the treatment of Abdominal Aortic Aneurysms (AAA) is the Endovascular Aneurysm Repair (EVAR). This minimally invasive procedure involves inserting a prosthesis in the aortic vessel that excludes the aneurysm from the bloodstream. The stent, once in place acts as a false lumen for the blood current to travel down, and not into the surrounding aneurysm sac. This procedure, therefore, immediately takes the pressure off the aneurysm, which thromboses itself after some time. Nevertheless, in a long term perspective, different complications such as prosthesis displacement or bloodstream leaks into or from the aneurysmatic bulge (endoleaks) could appear causing a pressure elevation and, as a result, increasing the danger of rupture. The purpose of this work is to explore the application of image registration techniques to the visual detection of changes in the thrombus in order to assess the evolution of the aneurysm. Prior to registration, both the lumen and the thrombus are segmented

  10. Engendering climate change-induced migration

    Science.gov (United States)

    Caretta, Martina Angela; Miletto, Michela

    2017-04-01

    Climate change leads to increased climate variability, which is manifest in extreme weather events such as floods and droughts. These put at stake agricultural productivity, forestry, inland fisheries, aquaculture, water supply and sanitation which in turn hamper poorest householdś self-sufficiency and capability to cope with risks. Due to the risk of losing or the actual loss of livelihood, farmers in the Global South must look for alternative strategies to diversify risk. Migration is one of those strategies, which that can be seen either as an adaptive measure or an indicator of limits to adaptation to environmental stress. 60% of young migrants live in the Global South (UN, 2013). Many internally displaced people in the world are under the age of 18, some move with their families, other, mostly in South Asia and West Africa, migrate alone. Youth, as all migrants, are seeking better economic opportunities to support themselves and their families. Migration is a gendered process which plays out differently in diverse societies depending on local cultural norms that do not only affect and are affected by gender roles, but also by age, class and ethnicity. Threats to water availability, access and water hazards have diverse impacts on men and women. The link gender and climate-induced migration is still under investigation and few studies provide concrete country specific examples of this phenomenon. Our paper will present a state of the art literature review around climate-induced migration in the Global South from a gender perspective showing how meńs and womeńs migratory decisions, patterns and outcomes differ at the stage pre-during post migration.

  11. On-line dynamic measurement of blood viscosity, hematocrit and change of blood volume

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective: To develop an on-line system for the measurement of blood viscosity and hematocrit. The dynamic changes of the macrovascular blood volumes,microvascular blood volumes and the total blood volume were observed by means of calculating from the testing result. Methods: Applying traditional viscosity measurement principle and specific wavelength optic density measurement method, an on-line system for the measurement of blood viscosity and hematocrit was developed, and the A/D multifunctionai board and the testing circuit were designed by ourselves. The system was validated by experiments both in vitro and in vivo. Therapeutic effects of hypertonic saline dextran solution (HSD) and Lactatic Ringer's solution at the early stage after burn-blast combined injury were compared by this method. Results: The results showed that the system has attained the goal of the design. The changes of the blood viscosity and hematocrit could be detected effectively and continuously. The changes of macrovascular, microvascular and total blood volume could be calculated approximately. Conclusions: The system and the method can continuously on-line test the blood viscosity and hematocrit, and reveal the change and distribution of blood volumes more accurately and dearly in the therapy process by estimating changes of the macrovascular, microvascular and total blood volumes, respectively. It has confirmed that HSD treatment could increase blood pressure and attenuate tissue edema by significantly increasing total blood volume,improving macrocirculatory and microcirculatory blood volumes. This study suggested that it could be desirable to develop an experiment technique based on the method mentioned above.

  12. Evidence for the changes of pituitary volumes in patients with post-traumatic stress disorder.

    Science.gov (United States)

    Atmaca, Murad; Ozer, Omer; Korkmaz, Sevda; Taskent, Ismail; Yildirim, Hanefi

    2017-02-28

    In pubertal and postpubertal patients with post-traumatic stress disorder (PTSD), significantly greater pituitary gland volumes have been reported. Moving from this point, in the present study, we aimed to investigate pituitary gland volumes in patients with PTSD and hypothesized that volumes of the gland would be structurally changed. Volumetric magnetic resonance imaging of the pituitary gland was performed among sixteen patients with PTSD and fifteen healthy control subjects. We found that the mean volume of the pituitary gland was statistically significant and smaller than that of healthy subjects (0.69±0.08cm(3) for patient group and 0.83±0.21 for control subjects). Consequently, in the present study, we found that patients with PTSD had smaller pituitary gland volumes than those of healthy controls like other anxiety disorders. It is important to provide support for this finding in future longitudinal investigations. Copyright © 2016. Published by Elsevier B.V.

  13. Longitudinal changes in hippocampal volumes and cognition in remitted geriatric depressive disorder.

    Science.gov (United States)

    Hou, Zhenghua; Yuan, Yonggui; Zhang, Zhijun; Bai, Feng; Hou, Gang; You, Jiayong

    2012-02-01

    Growing evidences suggest that the abnormality of hippocampal volume may occur in the process of depression. In this longitudinal study, we calculated the hippocampal volume of 14 remitted geriatric depressed (RGD) patients and 19 healthy participants at baseline and follow-up. We found significant improvement of performance in Trail Making Test-A (P=0.038) and Test-B (P=0.032), and the right hippocampal volume increased mildly in RGD. However, in RGD patients, positive correlations were seen between the changes in right hippocampal volumes and Symbol Digit Modality Test scores (r=0.675, P=0.008), and changes in left hippocampal volumes and Mini-Mental State Examination scores (r=0.743, P=0.002). Our findings suggest that hippocampus related cognitive impairment and previously addressed decreased hippocampal volume might represent a state rather than a permanent trait of the depressive disorder. The results suggest that hippocampal volume may be a useful risk marker for conversion to Alzheimer's disease in RGD patients. Additionally, our study indicates that effective antidepressants treatment might postpone and even revise the deterioration of hippocampus to some degree. Copyright © 2011 Elsevier B.V. All rights reserved.

  14. Modulation of KCNQ4 channel activity by changes in cell volume

    DEFF Research Database (Denmark)

    Hougaard, Charlotte; Klaerke, Dan A; Hoffmann, Else K;

    2004-01-01

    KCNQ4 channels expressed in HEK 293 cells are sensitive to cell volume changes, being activated by swelling and inhibited by shrinkage, respectively. The KCNQ4 channels contribute significantly to the regulatory volume decrease (RVD) process following cell swelling. Under isoosmotic conditions......, the KCNQ4 channel activity is modulated by protein kinases A and C, G protein activation, and a reduction in the intracellular Ca2+ concentration, but these signalling pathways are not responsible for the increased channel activity during cell swelling....

  15. Temporal dynamics and determinants of whole brain tissue volume changes during recovery from alcohol dependence.

    Science.gov (United States)

    Gazdzinski, Stefan; Durazzo, Timothy C; Meyerhoff, Dieter J

    2005-06-01

    Brain shrinkage and its partial reversibility with abstinence is a common neuroimaging finding in alcohol dependent individuals. We used an automated three-dimensional whole brain magnetic resonance imaging method (boundary shift integral) in 23 alcohol dependent individuals to measure the temporal dynamics of cerebral tissue and spinal fluid volume changes over a 12-month interval and to examine the major determinants of brain tissue change rates during abstinence and non-abstinence. We found more rapid brain tissue gain during the first month of sobriety than in the following months. The most rapid volume recovery was observed in abstinent individuals with the greatest baseline brain shrinkage and drinking severity. The rapid reversal of brain volume gains in non-abstinent individuals and tissue volume changes are modulated by duration of abstinence and non-abstinence periods, as well as recency of non-abstinence. Age, family history density of alcoholism, relapse severity, and duration or age of onset of heavy drinking were not major determinants of brain shrinkage and brain volume recovery rates. Treatment providers may use this tangible information to reinforce the biomedical benefits of sobriety. Previous quantitative measurements of brain volumes in alcohol dependent individuals performed after several weeks of abstinence likely underestimated the full extent of chronic alcohol-associated brain shrinkage.

  16. Airborne laser quantification of Florida shoreline and beach volume change caused by hurricanes

    Science.gov (United States)

    Robertson, William, V.

    This dissertation combines three separate studies that measure coastal change using airborne laser data. The initial study develops a method for measuring subaerial and subaqueous volume change incrementally alongshore, and compares those measurements to shoreline change in order to quantify their relationship in Palm Beach County, Florida. A poor correlation (R2 = 0.39) was found between shoreline and volume change before the hurricane season in the northern section of Palm Beach County because of beach nourishment and inlet dynamics. However, a relatively high R2 value of 0.78 in the southern section of Palm Beach County was found due to little disturbance from tidal inlets and coastal engineering projects. The shoreline and volume change caused by the 2004 hurricane season was poorly correlated with R 2 values of 0.02 and 0.42 for the north and south sections, respectively. The second study uses airborne laser data to investigate if there is a significant relationship between shoreline migration before and after Hurricane Ivan near Panama City, Florida. In addition, the relationship between shoreline change and subaerial volume was quantified and a new method for quantifying subaqueous sediment change was developed. No significant spatial relationship was found between shoreline migration before and after the hurricane. Utilization of a single coefficient to represent all relationships between shoreline and subaerial volume change was found to be problematic due to the spatial variability in the linear relationship. Differences in bathymetric data show only a small portion of sediment was transported beyond the active zone and most sediment remained within the active zone despite the occurrence of a hurricane. The third study uses airborne laser bathymetry to measure the offshore limit of change, and compares that location with calculated depth of closures and subaqueous geomorphology. There appears to be strong geologic control of the depth of closure in

  17. Failure Analysis and Design Changes of Oxygen Pump Inducers

    Institute of Scientific and Technical Information of China (English)

    梁恒力; 陈佐一

    2001-01-01

    The failure of an oxygen pump inducer during a test run was found to be the result of flow induced vibration. Oscillating fluid mechanics theory was used to determine the oscillating flow field around the inducer for various external oscillating perturbation fretuencies. Enormous pressures can occur at some frequencies, which are sufficient to break the inducer. Some design changes were analyzed to improve the flow induced vibration characteristics.

  18. Brain putamen volume changes in newly-diagnosed patients with obstructive sleep apnea.

    Science.gov (United States)

    Kumar, Rajesh; Farahvar, Salar; Ogren, Jennifer A; Macey, Paul M; Thompson, Paul M; Woo, Mary A; Yan-Go, Frisca L; Harper, Ronald M

    2014-01-01

    Obstructive sleep apnea (OSA) is accompanied by cognitive, motor, autonomic, learning, and affective abnormalities. The putamen serves several of these functions, especially motor and autonomic behaviors, but whether global and specific sub-regions of that structure are damaged is unclear. We assessed global and regional putamen volumes in 43 recently-diagnosed, treatment-naïve OSA (age, 46.4 ± 8.8 years; 31 male) and 61 control subjects (47.6 ± 8.8 years; 39 male) using high-resolution T1-weighted images collected with a 3.0-Tesla MRI scanner. Global putamen volumes were calculated, and group differences evaluated with independent samples t-tests, as well as with analysis of covariance (covariates; age, gender, and total intracranial volume). Regional differences between groups were visualized with 3D surface morphometry-based group ratio maps. OSA subjects showed significantly higher global putamen volumes, relative to controls. Regional analyses showed putamen areas with increased and decreased tissue volumes in OSA relative to control subjects, including increases in caudal, mid-dorsal, mid-ventral portions, and ventral regions, while areas with decreased volumes appeared in rostral, mid-dorsal, medial-caudal, and mid-ventral sites. Global putamen volumes were significantly higher in the OSA subjects, but local sites showed both higher and lower volumes. The appearance of localized volume alterations points to differential hypoxic or perfusion action on glia and other tissues within the structure, and may reflect a stage in progression of injury in these newly-diagnosed patients toward the overall volume loss found in patients with chronic OSA. The regional changes may underlie some of the specific deficits in motor, autonomic, and neuropsychologic functions in OSA.

  19. Brain putamen volume changes in newly-diagnosed patients with obstructive sleep apnea

    Directory of Open Access Journals (Sweden)

    Rajesh Kumar

    2014-01-01

    Full Text Available Obstructive sleep apnea (OSA is accompanied by cognitive, motor, autonomic, learning, and affective abnormalities. The putamen serves several of these functions, especially motor and autonomic behaviors, but whether global and specific sub-regions of that structure are damaged is unclear. We assessed global and regional putamen volumes in 43 recently-diagnosed, treatment-naïve OSA (age, 46.4 ± 8.8 years; 31 male and 61 control subjects (47.6 ± 8.8 years; 39 male using high-resolution T1-weighted images collected with a 3.0-Tesla MRI scanner. Global putamen volumes were calculated, and group differences evaluated with independent samples t-tests, as well as with analysis of covariance (covariates; age, gender, and total intracranial volume. Regional differences between groups were visualized with 3D surface morphometry-based group ratio maps. OSA subjects showed significantly higher global putamen volumes, relative to controls. Regional analyses showed putamen areas with increased and decreased tissue volumes in OSA relative to control subjects, including increases in caudal, mid-dorsal, mid-ventral portions, and ventral regions, while areas with decreased volumes appeared in rostral, mid-dorsal, medial-caudal, and mid-ventral sites. Global putamen volumes were significantly higher in the OSA subjects, but local sites showed both higher and lower volumes. The appearance of localized volume alterations points to differential hypoxic or perfusion action on glia and other tissues within the structure, and may reflect a stage in progression of injury in these newly-diagnosed patients toward the overall volume loss found in patients with chronic OSA. The regional changes may underlie some of the specific deficits in motor, autonomic, and neuropsychologic functions in OSA.

  20. Global end-diastolic volume increases to maintain fluid responsiveness in sepsis-induced systolic dysfunction

    NARCIS (Netherlands)

    R.J. Trof (R.); I. Danad (Ibrahim); A.B.J. Groeneveld (Johan)

    2013-01-01

    textabstractBackground: Sepsis-induced cardiac dysfunction may limit fluid responsiveness and the mechanism thereof remains unclear. Since cardiac function may affect the relative value of cardiac filling pressures, such as the recommended central venous pressure (CVP), versus filling volumes in gui

  1. Can flow-volume loops be used to diagnose exercise induced laryngeal obstructions?

    DEFF Research Database (Denmark)

    Christensen, Pernille M; Maltbæk, Niels; Jørgensen, Inger M

    2013-01-01

    BACKGROUND: Pre- and post-exercise flow-volume loops are often recommended as an easy non-invasive method for diagnosing or excluding exercise-induced laryngeal obstructions in patients with exercise-related respiratory symptoms. However, at present there is no evidence for this recommendation....... AIMS: To compare physician evaluated pre- and post-exercise flow-volume loops and flow data with laryngoscopic findings during exercise. METHODS: Data from 100 consecutive exercise tests with continuous laryngoscopy during the test were analysed. Laryngoscopic images were compared...... with the corresponding pre- and post-exercise flow-volume loops assessed by four separate physicians and with data from the loops (forced inspiratory flow (FIF) at 25% vs. FIF at 75% of forced inspiratory vital capacity (FIVC), forced expiratory flow at 50% of forced expiratory volume vs. FIF at 50% of FIVC, and FIVC vs...

  2. Electrolyte and Haemogram changes post large volume liposuction comparing two different tumescent solutions

    Directory of Open Access Journals (Sweden)

    Kumar Vivek

    2014-01-01

    Full Text Available Background: The most common definitions of large volume liposuction refer to total 5 l volume aspiration during a single procedure (fat plus wetting solution. Profound haemodynamic and metabolic alterations can accompany large volume liposuction. Due to paucity of literature on the effect of different tumescent solutions on the electrolyte balance and haematological changes during large volume liposuction, we carried out this study using two different wetting solutions to study the same. Materials and Methods: Total 30 patients presenting with varying degrees of localized lipodystrophy in different body regions were enrolled for the study. Prospective randomized controlled trial was conducted by Department of Plastic and Cosmetic Surgery, Sir Ganga Ram Hospital, New Delhi from January 2011 to June 2012. Patients were randomized into two groups of 15 patients each by using computer generated random numbers. Tumescent formula used for Group A (normal saline [NS] was our modification of Klein′s Formula and Tumescent formula used for Group B (ringer lactate [RL] was our modification of Hunstadt′s formula. Serum electrolytes and hematocrit levels were done at preinduction, immediate postoperative period and postoperative day 1. Result: Statistical analysis was performed using SPSS software version 15.0. Which showed statistically significant electrolytes and hematocrit changes occur during large volume liposuction. Conclusion: Statistically significant electrolytes and hematocrit changes occur during large volume liposuction and patients should be kept under observation of anaesthesist for at least 24 h. Patients require strict monitoring of vital parameters and usually Intensive Care Unit is not required. There was no statistical difference in the electrolyte changes using NS or RL as tumescent solution and both solutions were found safe for large volume liposuction.

  3. Production-induced changes in reservoir geomechanics

    Science.gov (United States)

    Amoyedo, Sunday O.

    Sand production remains a source of concern in both conventional and heavy oil production. Porosity increase and changes in local stress magnitude, which often enhance permeability, have been associated with severe sanding. On the other hand, sand production has been linked to a large number of field incidences involving loss of well integrity, casing collapse and corrosion of down-hole systems. It also poses problems for separators and transport facilities. Numerous factors such as reservoir consolidation, well deviation angle through the reservoir, perforation size, grain size, capillary forces associated with water cut, flow rate and most importantly reservoir strain resulting from pore pressure depletion contribute to reservoir sanding. Understanding field-specific sand production patterns in mature fields and poorly consolidated reservoirs is vital in identifying sand-prone wells and guiding remedial activities. Reservoir strain analysis of Forties Field, located in the UK sector of the North Sea, shows that the magnitude of the production-induced strain, part of which is propagated to the base of the reservoir, is of the order of 0.2 %, which is significant enough to impact the geomechanical properties of the reservoir. Sand production analysis in the field shows that in addition to poor reservoir consolidation, a combined effect of repeated perforation, high well deviation, reservoir strain and high fluid flow rate have contributed significantly to reservoir sanding. Knowledge of reservoir saturation variation is vital for in-fill well drilling, while information on reservoir stress variation provides a useful guide for sand production management, casing design, injector placement and production management. Interpreting time-lapse difference is enhanced by decomposing time-lapse difference into saturation, pressure effects and changes in rock properties (e.g. porosity) especially in highly compacting reservoirs. Analyzing the stress and saturation

  4. Acute Experimental Hyperthyroidism Does Not Affect Basal and Volume-Induced Atrial Natriuretic Peptide Secretion in Healthy Subjects

    Directory of Open Access Journals (Sweden)

    Gregory Giamouzis

    2011-01-01

    Full Text Available Background. Excess circulating thyroid hormones are associated with increased cardiac atrial natriuretic peptide (ANP secretion but the exact mechanisms involved have not been fully elucidated in vivo. Methods. To examine whether thyroid hormone regulation of ANP secretion is the result of a direct action on the myocardium and/or of an indirect action through alterations in the peripheral circulation, plasma ANP levels (baseline and volume expansion-induced were evaluated in 14 healthy men, before and after triiodothyronine (T3 administration. Results. T3 administration was followed by a significant increase in serum T3 levels and a significant decrease in serum TSH levels, without significantly affecting ANP levels. Systemic vascular resistance, plasma rennin activity (PRA, and aldosterone (ALDO levels, as well as indices of left atrial function, were not significantly altered, despite a significant increase in cardiac output. Plasma volume expansion, induced by a 1500 ml normal saline (NSal infusion, both before and after T3 administration, was followed by a significant decrease in PRA and ALDO and a significant increase in plasma ANP levels, without significantly affecting the mean blood pressure (BP and heart rate (HR in each study period. The NSal-induced response, measured as the integrated area under the curve corrected for baseline values (-AUC, was not different after T3 administration for ANP, ALDO, PRA, HR, and mean BP. Conclusion. In vivo thyroid hormone-induced myocardial ANP secretion is the result of an indirect action mainly through hemodynamic changes that increase atrial stretch.

  5. Expression Changes of Early Response Genes in Lung Due to High Volume Ventilation

    Institute of Scientific and Technical Information of China (English)

    WANG Yuelan; YAO Shanglong; XIONG Ping

    2005-01-01

    Summary: The expression changes of early response genes due to ventilation with high volume in adult rats in vivo were observed. Forty SD male rats were randomly divided into control and 30, 60, 90 and 120 min ventilation groups, respectively (n=8 in each group). The animals were ventilated with tidal volume of 42 ml/kg and a PEEP level of 0 cmH2O at a rate of 40 breaths per minute in room air with a ventilator was given to the small animals. The expression of Egr-1, C-jun and IL-1β mRNA and proteins was detected by RT-PCR and immunohistochemical technique, respectively. The pathological changes in lung tissues were examined by HE staining. The results indicated that the expression of Egr-1, C-jun and IL-1β mRNA was detectable at 30th min after overventilation, but there was no significant difference in comparison with that in control group until overventilation for 60 min. However, at 90 and 120 min there was a significent increase as compared with 30 min or control group (P<0.05). The expression of Egr-1, C-jun and IL-1β deteced by immunohistochemical assay also showed a similar tendency of the gradual increase. In the 120 min ventilation group, the expression intensity of Egr-1, C-jun and IL-1β proteins in lung cells was the strongest and the nuclear translocation was increased markedly in comparison with any other groups (P<0.05). HE staining suggested that the degree of lung injury was aggravated gradually with the ventialtion going on and had a similar tendency to the expression of these early response genes and proteins. The current data suggested that overventilation activated and upregulated the expression of early response genes and the expression of these genes may be taken as the early signal to predict the onset and degree of lung injury. These results may demonstrated partially that the expression of early response genes induced by the mechanical stretch is associated with biochamic lung injury.

  6. Expiratory computed tomographic techniques: a cause of a poor rate of change in lung volume.

    Science.gov (United States)

    Morikawa, Keiko; Okada, Fumito; Mori, Hiromu

    2015-01-01

    Ninety-nine patients (29 males and 70 females; mean age, 57.1 years; range, 22-81 years) were included in this study to evaluate the factors affecting smaller lung volume changes in expiratory high-resolution computed tomography performed to depict air trapping. All patients underwent inspiratory and expiratory chest thin-section CT examinations and pulmonary function tests. Air trapping on CT images was graded subjectively. All variables (age, sex, diagnosis, pulmonary function index, and air trapping score) were compared with the degree of change in lung volume between the inspiratory and expiratory CT examinations. The variables affecting a lower degree of volume change were vital capacity, forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1.0), and the FEV1.0/FVC ratio. Bronchiolitis obliterans was the dominant diagnosis in patients with insufficient degrees of breath holding and in patients with negative air trapping scores despite an abnormal air trapping index. An insufficient degree of lung changes between inspiration and expiration on CT examinations represented bronchiolitis obliterans, which resulted in low FEV1.0 and FEV1.0/FVC values. Changes in the time gap from the announcement of exhalation and breath holding to the start of scanning most effectively indicated air trapping in patients with bronchiolar disorders.

  7. EFFECT OF SITTING POSTURE ON THORACIC CONFIGURATION AND CHANGES IN VOLUME OF HEMITHORACES

    Directory of Open Access Journals (Sweden)

    Shōbo A

    2017-06-01

    Full Text Available Background: Poor posture is detrimental to breathing. Our purpose was to investigate the effect of upright and hunchbacked sitting on thoracic configuration and changes in the volume of the thorax during quiet and volitional deep breathing. Methods: The participants were 11 healthy men with a mean age of 21.6 years, mean body mass of 59.8 kg, mean height of 169.7 cm and a body mass index of 20.7 kg/m2. Eighty-four reflective markers were placed on the trunk. Three-dimensional motion analysis measured the volume within the hemithoraces. To calculate upper and lower thoracic volumes, six imaginary hexahedra were visualized using four reflective markers for each on both aspects of the thorax. Each hexahedron was divided into three imaginary triangular pyramids to calculate positional vectors. Finally, the volume for the hexahedra and triangular pyramids was calculated. Upper thoracic volume encompassed a space from the sternal notch to a midpoint on the ventral aspect of the third rib and the lower thoracic volume from the xiphoid process to the midpoint on tenth rib’s dorsal aspect. Results: In hunchbacked sitting during quiet breathing the left lower hemithorax yielded a significantly larger volume (p=0.003, and both breathing patterns during inspiration and expiration yielded a significantly greater change in thoracic configuration (p=0.01, p=0.016. Conclusion: Findings suggested that, in a hunchbacked sitting, there was decreased thoracic asymmetry with re-establishment of thoracic vertebral alignment, consequently stabilizing the sitting position, but breathing was suppressed and tidal volume decreased. Physiotherapy should aim at ensuring correction of hunchbacked posture and maintenance of thoracic symmetry.

  8. Forearm skin tissue dielectric constant measured at 300 MHz: effect of changes in skin vascular volume and blood flow.

    Science.gov (United States)

    Mayrovitz, Harvey N; Guo, Xiaoran; Salmon, Mark; Uhde, Matt

    2013-01-01

    Skin tissue dielectric constant (TDC) values measured via the open-ended coaxial probe method are useful non-invasive indices of local skin tissue water. However, the effect of skin blood flow (SBF) or skin blood volume (SBV) on TDC values is unknown. To determine the magnitude of such effects, we decreased forearm SBV via vertical arm raising for 5 min (test 1) and increased SBV by bicep cuff compression to 50 mmHg for 5 min (test 2) in 20 healthy supine subjects (10 men). TDC values were measured to a depth of 1·5 mm on anterior forearm, and SBF was measured with laser-Doppler system simultaneously on forearm and finger. Results indicate that decreasing vascular volume (test 1) was associated with a small but statistically significant reduction in TDC (3·0 ± 4·3%, P = 0·003) and increasing vascular volume (test 2) was associated with a slight but statistically significant increase in TDC (3·5 ± 3·0%, PTDC values (3·0-3·5%) over the wide range of induced SBV and SBF changes suggest a minor effect on clinically determined TDC values because of SBV or SBF changes or differences when comparing TDC longitudinally over time or among individuals of different groups in a research setting.

  9. Assessing high altitude glacier thickness, volume and area changes using field, GIS and remote sensing techniques: the case of Nevado Coropuna (Peru

    Directory of Open Access Journals (Sweden)

    P. Peduzzi

    2010-08-01

    Full Text Available Higher temperatures and changes in precipitation patterns have induced an acute decrease in Andean glaciers, thus leading to additional stress on water supply. To adapt to climate changes, local governments need information on the rate of glacier area and volume losses and on current ice thickness. Remote sensing analyses of Coropuna glacier (Peru delineate an acute glaciated area decline between 1955 and 2008. We tested how volume changes can be estimated with remote sensing and GIS techniques using digital elevation models derived from both topographic maps and satellite images. Ice thickness was measured in 2004 using a Ground Penetrating Radar coupled with a Ground Positioning System during a field expedition. It provided profiles of ice thickness on different slopes, orientations and altitudes. These were used to model the current glacier volume using Geographical Information System and statistical multiple regression techniques. The results revealed a significant glacier volume loss; however the uncertainty is higher than the measured volume loss. We also provided an estimate of the remaining volume. The field study provided the scientific evidence needed by COPASA, a local Peruvian NGO, and GTZ, the German international cooperation agency, in order to alert local governments and communities and guide them in adopting new climate change adaptation policies.

  10. Dynamic cortical gray matter volume changes after botulinum toxin in cervical dystonia

    NARCIS (Netherlands)

    Delnooz, C.C.S.; Pasman, J.W.; Warrenburg, B.P.C. van de

    2015-01-01

    Previous electrophysiological and functional imaging studies in focal dystonia have reported on cerebral reorganization after botulinum toxin (BoNT) injections. With the exception of microstructural changes, alterations in gray matter volume after BoNT have not been explored. In this study, we

  11. Surprising volume change in PPy(DBS): An atomic force microscopy study

    DEFF Research Database (Denmark)

    Smela, E.; Gadegaard, N.

    1999-01-01

    Communication: Conjugated polymers such as polypyrrole (PPy) have potential use as artificial muscles or in microsystems such as valves for micro-fluid handling. One of the most important parameters in such uses is the magnitude of volume change during associated redox processes; however, until now...

  12. Changes in forced expiratory volume in 1 second over time in COPD

    DEFF Research Database (Denmark)

    Vestbo, Jørgen; Edwards, Lisa D; Scanlon, Paul D

    2011-01-01

    A key feature of chronic obstructive pulmonary disease (COPD) is an accelerated rate of decline in forced expiratory volume in 1 second (FEV(1)), but data on the variability and determinants of this change in patients who have established disease are scarce....

  13. Challenges in Accommodating Volume Change of Si Anodes for Li-Ion Batteries.

    Science.gov (United States)

    Ko, Minseong; Chae, Sujong; Cho, Jaephil

    2015-11-01

    Si has been considered as a promising alternative anode for next-generation Li-ion batteries (LIBs) because of its high theoretical energy density, relatively low working potential, and abundance in nature. However, Si anodes exhibit rapid capacity decay and an increase in the internal resistance, which are caused by the large volume changes upon Li insertion and extraction. This unfortunately limits their practical applications. Therefore, managing the total volume change remains a critical challenge for effectively alleviating the mechanical fractures and instability of solid-electrolyte-interphase products. In this regard, we review the recent progress in volume-change-accommodating Si electrodes and investigate their ingenious structures with significant improvements in the battery performance, including size-controlled materials, patterned thin films, porous structures, shape-preserving shell designs, and graphene composites. These representative approaches potentially overcome the large morphologic changes in the volume of Si anodes by securing the strain relaxation and structural integrity in the entire electrode. Finally, we propose perspectives and future challenges to realize the practical application of Si anodes in LIB systems.

  14. Changes in forced expiratory volume in 1 second over time in COPD

    DEFF Research Database (Denmark)

    Vestbo, Jørgen; Edwards, Lisa D; Scanlon, Paul D

    2011-01-01

    A key feature of chronic obstructive pulmonary disease (COPD) is an accelerated rate of decline in forced expiratory volume in 1 second (FEV(1)), but data on the variability and determinants of this change in patients who have established disease are scarce....

  15. Application of Nuclear Volume Measurements to Comprehend the Cell Cycle in Root-Knot Nematode-Induced Giant Cells

    Directory of Open Access Journals (Sweden)

    José Dijair Antonino de Souza Junior

    2017-06-01

    Full Text Available Root-knot nematodes induce galls that contain giant-feeding cells harboring multiple enlarged nuclei within the roots of host plants. It is recognized that the cell cycle plays an essential role in the set-up of a peculiar nuclear organization that seemingly steers nematode feeding site induction and development. Functional studies of a large set of cell cycle genes in transgenic lines of the model host Arabidopsis thaliana have contributed to better understand the role of the cell cycle components and their implication in the establishment of functional galls. Mitotic activity mainly occurs during the initial stages of gall development and is followed by an intense endoreduplication phase imperative to produce giant-feeding cells, essential to form vigorous galls. Transgenic lines overexpressing particular cell cycle genes can provoke severe nuclei phenotype changes mainly at later stages of feeding site development. This can result in chaotic nuclear phenotypes affecting their volume. These aberrant nuclear organizations are hampering gall development and nematode maturation. Herein we report on two nuclear volume assessment methods which provide information on the complex changes occurring in nuclei during giant cell development. Although we observed that the data obtained with AMIRA tend to be more detailed than Volumest (Image J, both approaches proved to be highly versatile, allowing to access 3D morphological changes in nuclei of complex tissues and organs. The protocol presented here is based on standard confocal optical sectioning and 3-D image analysis and can be applied to study any volume and shape of cellular organelles in various complex biological specimens. Our results suggest that an increase in giant cell nuclear volume is not solely linked to increasing ploidy levels, but might result from the accumulation of mitotic defects.

  16. Salt wastage, plasma volume contraction and hypokalemic paralysis in self-induced water intoxication.

    Science.gov (United States)

    Tanneau, R S; Pennec, Y L; Morin, J F; Codet, J P; Bourbigot, B; Garre, M; Le Menn, G

    1993-01-01

    Eleven episodes of severe hyponatremia secondary to hiccup-induced potomania were recorded in 3 years in a man who had essential hypertension, a low protein intake and a normal diluting ability. Paradoxical increase in hematocrit and plasma protein with acute extensive natriuresis was associated as well as urine potassium loss and hypokalemia producing paralysis in 1 episode. During a chronic water loading test, the defect in water excretion was related to a low urine solute delivery which was partially reverted by the natriuretic response to plasma volume expansion, promoting water diuresis. In acute water intoxication, this natriuretic response was exaggerated, producing a brisk water diuresis. Plasma volume was rapidly normalized but without any improvement in plasma sodium due to the concomitant negative sodium balance. Thus, water diuresis persisted until plasma volume was significantly contracted. Potassium loss appeared to be related to sodium excretion. Metabolic disturbances have not reoccurred despite persistent hiccup and potomania during 2 years of urea therapy.

  17. Mechanism of Calcined Phosphogypsum for the Volume Change of Blended Cement

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The paper describes an investigation into the volume change of cement mortar specimen at the three kinds of different curing schedules including 20℃ and 5% Na2SO4 solution curing, tap water standard curing, 50% RH curing for 90 days. The testing results of hydration heat, chemical shrinking and XRD prove that calcined phosphogypsum has evident excitation effect on the activity of high calcium ash and steel slag. Simultaneously, calcined phosphogypsum has the function of decreasing volume shrinkage to blended cement possessing steel slag and high calcium ash. In sulfate curing, calcined phosphogypsum can avoid the phenomenon of protrude apex of the blended cement.

  18. A lattice Boltzmann coupled to finite volumes method for solving phase change problems

    Directory of Open Access Journals (Sweden)

    El Ganaoui Mohammed

    2009-01-01

    Full Text Available A numerical scheme coupling lattice Boltzmann and finite volumes approaches has been developed and qualified for test cases of phase change problems. In this work, the coupled partial differential equations of momentum conservation equations are solved with a non uniform lattice Boltzmann method. The energy equation is discretized by using a finite volume method. Simulations show the ability of this developed hybrid method to model the effects of convection, and to predict transfers. Benchmarking is operated both for conductive and convective situation dominating solid/liquid transition. Comparisons are achieved with respect to available analytical solutions and experimental results.

  19. Assessing high altitude glacier volume change and remaining thickness using cost-efficient scientific techniques: the case of Nevado Coropuna (Peru

    Directory of Open Access Journals (Sweden)

    P. Peduzzi

    2009-10-01

    Full Text Available Higher temperature and change in precipitation patterns have induced an acute decrease in Andean glaciers, thus leading to an additional stress on water supply. To adapt to climate changes, local governments need information on the rate of glacier volume losses and on current ice thickness. We show how volume changes can be accurately estimated in remote areas using readily available low-cost digital elevation models derived from both topographic maps and satellite images. They were used for estimating the volume changes over the Coropuna glacier (Peru from 1955 to 2002. Ice thickness was measured in 2004 using a georadar coupled with Ground Positioning System during a field expedition. It provided profiles of ice thickness on different slopes, orientations and altitudes. These were used to model the current glacier volume using Geographical Information System and statistical multiple regressions techniques. Computers were modified to resists to high altitude (6500 m temperatures and low pressure conditions. The results delineated a significant glacier volume loss and provided an estimate of the remaining ice. It provided the scientific evidence needed by local Peruvian NGO, COPASA, and the German Cooperation Program in order to alert local governments and communities and for enforcing new climate change adaptation policies.

  20. Changes in subcutaneous fat cell volume and insulin sensitivity after weight loss.

    Science.gov (United States)

    Andersson, Daniel P; Eriksson Hogling, Daniel; Thorell, Anders; Toft, Eva; Qvisth, Veronica; Näslund, Erik; Thörne, Anders; Wirén, Mikael; Löfgren, Patrik; Hoffstedt, Johan; Dahlman, Ingrid; Mejhert, Niklas; Rydén, Mikael; Arner, Erik; Arner, Peter

    2014-07-01

    Large subcutaneous fat cells associate with insulin resistance and high risk of developing type 2 diabetes. We investigated if changes in fat cell volume and fat mass correlate with improvements in the metabolic risk profile after bariatric surgery in obese patients. Fat cell volume and number were measured in abdominal subcutaneous adipose tissue in 62 obese women before and 2 years after Roux-en-Y gastric bypass (RYGB). Regional body fat mass by dual-energy X-ray absorptiometry; insulin sensitivity by hyperinsulinemic-euglycemic clamp; and plasma glucose, insulin, and lipid profile were assessed. RYGB decreased body weight by 33%, which was accompanied by decreased adipocyte volume but not number. Fat mass in the measured regions decreased and all metabolic parameters were improved after RYGB (P fat cell size correlated strongly with improved insulin sensitivity (P = 0.0057), regional changes in fat mass did not, except for a weak correlation between changes in visceral fat mass and insulin sensitivity and triglycerides. The curve-linear relationship between fat cell size and fat mass was altered after weight loss (P = 0.03). After bariatric surgery in obese women, a reduction in subcutaneous fat cell volume associates more strongly with improvement of insulin sensitivity than fat mass reduction per se. An altered relationship between adipocyte size and fat mass may be important for improving insulin sensitivity after weight loss. Fat cell size reduction could constitute a target to improve insulin sensitivity. © 2014 by the American Diabetes Association.

  1. Reduced expression of glucocorticoid-inducible genes GILZ and SGK-1: high IL-6 levels are associated with reduced hippocampal volumes in major depressive disorder.

    LENUS (Irish Health Repository)

    Frodl, T

    2012-01-01

    Neuroplasticity may have a core role in the pathophysiology of major depressive disorder (MDD), a concept supported by experimental studies that found that excessive cortisol secretion and\\/or excessive production of inflammatory cytokines impairs neuronal plasticity and neurogenesis in the hippocampus. The objective of this study was to examine how changes in the glucocorticoid and inflammatory systems may affect hippocampal volumes in MDD. A multimodal approach with structural neuroimaging of hippocampus and amygdala, measurement of peripheral inflammatory proteins interleukin (IL)-6 and C-reactive protein (CRP), glucocorticoid receptor (GR) mRNA expression, and expression of glucocorticoid-inducible genes (glucocorticoid-inducible genes Leucin Zipper (GILZ) and glucocorticoid-inducible kinase-1 (SGK-1)) was used in 40 patients with MDD and 43 healthy controls (HC). Patients with MDD showed smaller hippocampal volumes and increased inflammatory proteins IL-6 and CRP compared with HC. Childhood maltreatment was associated with increased CRP. Patients with MDD, who had less expression of the glucocorticoid-inducible genes GILZ or SGK-1 had smaller hippocampal volumes. Regression analysis showed a strong positive effect of GILZ and SGK-1 mRNA expression, and further inverse effects of IL-6 concentration, on hippocampal volumes. These findings suggest that childhood maltreatment, peripheral inflammatory and glucocorticoid markers and hippocampal volume are interrelated factors in the pathophysiology of MDD. Glucocorticoid-inducible genes GILZ and SGK-1 might be promising candidate markers for hippocampal volume changes relevant for diseases like MDD. Further studies need to explore the possible clinical usefulness of such a blood biomarker, for example, for diagnosis or prediction of therapy response.

  2. Volume change determination of metastatic lung tumors in CT images using 3-D template matching

    Science.gov (United States)

    Ambrosini, Robert D.; Wang, Peng; O'Dell, Walter G.

    2009-02-01

    The ability of a clinician to properly detect changes in the size of lung nodules over time is a vital element to both the diagnosis of malignant growths and the monitoring of the response of cancerous lesions to therapy. We have developed a novel metastasis sizing algorithm based on 3-D template matching with spherical tumor appearance models that were created to match the expected geometry of the tumors of interest while accounting for potential spatial offsets of nodules in the slice thickness direction. The spherical template that best-fits the overall volume of each lung metastasis was determined through the optimization of the 3-D normalized cross-correlation coefficients (NCCC) calculated between the templates and the nodules. A total of 17 different lung metastases were extracted manually from real patient CT datasets and reconstructed in 3-D using spherical harmonics equations to generate simulated nodules for testing our algorithm. Each metastasis 3-D shape was then subjected to 10%, 25%, 50%, 75% and 90% scaling of its volume to allow for 5 possible volume change combinations relative to the original size per each reconstructed nodule and inserted back into CT datasets with appropriate blurring and noise addition. When plotted against the true volume change, the nodule volume changes calculated by our algorithm for these 85 data points exhibited a high degree of accuracy (slope = 0.9817, R2 = 0.9957). Our results demonstrate that the 3-D template matching method can be an effective, fast, and accurate tool for automated sizing of metastatic tumors.

  3. Socially Induced Changes in Legal Terminology

    Directory of Open Access Journals (Sweden)

    Matulewska Aleksandra

    2017-03-01

    Full Text Available The author intends to present evolutionary and revolutionary changes in legal terminology. Legal terminology changes as a result of language usage, technological development, political and social changes and even economy reasons. The following research methods have been applied: the terminological analysis of the research material (empirical observation, analysis of comparable texts and parametric approach to legal terminology comparison and the analysis of pertinent literature. The research material included legislation from the United Kingdom, the United States of America, Canada and Australia. The author focuses on terminological changes resulting from social transformations. Selected terms and their transformation in respect to meaning and form are elaborated on in the paper. Finally, the author draws conclusions that translation of such terminology should aim at communication precision and many of them may be false friends in interlingual communication.

  4. 3D mapping of cerebrospinal fluid local volume changes in patients with hydrocephalus treated by surgery: preliminary study

    Energy Technology Data Exchange (ETDEWEB)

    Hodel, Jerome [Hopital Roger Salengro, Department of Neuroradiology, Lille (France); Hopital Roger Salengro, Service de Neuroradiologie, Lille (France); Besson, Pierre; Pruvo, Jean-Pierre; Leclerc, Xavier [Hopital Roger Salengro, Department of Neuroradiology, Lille (France); Rahmouni, Alain; Grandjacques, Benedicte; Luciani, Alain [Hopital Henri Mondor, Department of Radiology, Creteil (France); Petit, Eric; Lebret, Alain [Signals Images and Intelligent Systems Laboratory, Creteil (France); Outteryck, Olivier [Hopital Roger Salengro, Department of Neurology, Lille (France); Benadjaoud, Mohamed Amine [Radiation Epidemiology Team, CESP, Centre for Research in Epidemiology and Population Health U1018, Villejuif (France); Maraval, Anne [Hopital Henri Mondor, Department of Neuroradiology, Creteil (France); Decq, Philippe [Hopital Henri Mondor, Department of Neurosurgery, Creteil (France)

    2014-01-15

    To develop automated deformation modelling for the assessment of cerebrospinal fluid (CSF) local volume changes in patients with hydrocephalus treated by surgery. Ventricular and subarachnoid CSF volume changes were mapped by calculating the Jacobian determinant of the deformation fields obtained after non-linear registration of pre- and postoperative images. A total of 31 consecutive patients, 15 with communicating hydrocephalus (CH) and 16 with non-communicating hydrocephalus (NCH), were investigated before and after surgery using a 3D SPACE (sampling perfection with application optimised contrast using different flip-angle evolution) sequence. Two readers assessed CSF volume changes using 3D colour-encoded maps. The Evans index and postoperative volume changes of the lateral ventricles and sylvian fissures were quantified and statistically compared. Before surgery, sylvian fissure and brain ventricle volume differed significantly between CH and NCH (P = 0.001 and P = 0.025, respectively). After surgery, 3D colour-encoded maps allowed for the visual recognition of the CSF volume changes in all patients. The amounts of ventricle volume loss of CH and NCH patients were not significantly different (P = 0.30), whereas readjustment of the sylvian fissure volume was conflicting in CH and NCH patients (P < 0.001). The Evans index correlated with ventricle volume in NCH patients. 3D mapping of CSF volume changes is feasible providing a quantitative follow-up of patients with hydrocephalus. (orig.)

  5. Removing Parallax-Induced False Changes in Change Detection

    Science.gov (United States)

    2014-03-27

    BS, MS Civilian, USAF Approved: //signed// 21 February 2014 Lt Col Michael J. Mendenhall , PhD (Co-Chair) Date //signed// 21 February 2014 Dr...appreciation to Lt Col Michael Mendenhall for his guidance, motivation, and support throughout the course of this effort. My sincerest appreciation goes to my...Vongsy, M.J. Mendenhall , P.M. Hanna, and J. Kaufman, “Change detection using synthetic hyperspectral imagery,” in Hyperspectral Image and Signal Pro

  6. Comparison of gray matter volume and thickness for analysis of cortical changes in Alzheimer's disease

    Science.gov (United States)

    Liu, Jiachao; Li, Ziyi; Chen, Kewei; Yao, Li; Wang, Zhiqun; Li, Kunchen; Guo, Xiaojuan

    2011-03-01

    Gray matter volume and cortical thickness are two indices of concern in brain structure magnetic resonance imaging research. Gray matter volume reflects mixed-measurement information of cerebral cortex, while cortical thickness reflects only the information of distance between inner surface and outer surface of cerebral cortex. Using Scaled Subprofile Modeling based on Principal Component Analysis (SSM_PCA) and Pearson's Correlation Analysis, this study further provided quantitative comparisons and depicted both global relevance and local relevance to comprehensively investigate morphometrical abnormalities in cerebral cortex in Alzheimer's disease (AD). Thirteen patients with AD and thirteen age- and gender-matched healthy controls were included in this study. Results showed that factor scores from the first 8 principal components accounted for ~53.38% of the total variance for gray matter volume, and ~50.18% for cortical thickness. Factor scores from the fifth principal component showed significant correlation. In addition, gray matter voxel-based volume was closely related to cortical thickness alterations in most cortical cortex, especially, in some typical abnormal brain regions such as insula and the parahippocampal gyrus in AD. These findings suggest that these two measurements are effective indices for understanding the neuropathology in AD. Studies using both gray matter volume and cortical thickness can separate the causes of the discrepancy, provide complementary information and carry out a comprehensive description of the morphological changes of brain structure.

  7. Changes to Hospital Inpatient Volume After Newspaper Reporting of Medical Errors.

    Science.gov (United States)

    Fukuda, Haruhisa

    2017-06-30

    The aim of this study was to investigate the influence of medical error case reporting by national newspapers on inpatient volume at acute care hospitals. A case-control study was conducted using the article databases of 3 major Japanese newspapers with nationwide circulation between fiscal years 2012 and 2013. Data on inpatient volume at acute care hospitals were obtained from a Japanese government survey between fiscal years 2011 and 2014. Panel data were constructed and analyzed using a difference-in-differences design. Acute care hospitals in Japan. Hospitals named in articles that included the terms "medical error" and "hospital" were designated case hospitals, which were matched with control hospitals using corresponding locations, nurse-to-patient ratios, and bed numbers. Medical error case reporting in newspapers. Changes to hospital inpatient volume after error reports. The sample comprised 40 case hospitals and 40 control hospitals. Difference-in-differences analyses indicated that newspaper reporting of medical errors was not significantly associated (P = 0.122) with overall inpatient volume. Medical error case reporting by newspapers showed no influence on inpatient volume. Hospitals therefore have little incentive to respond adequately and proactively to medical errors. There may be a need for government intervention to improve the posterror response and encourage better health care safety.

  8. Cell volume regulation in cultured human retinal Muller cells is associated with changes in transmembrane potential.

    Directory of Open Access Journals (Sweden)

    Juan M Fernández

    Full Text Available Müller cells are mainly involved in controlling extracellular homeostasis in the retina, where intense neural activity alters ion concentrations and osmotic gradients, thus favoring cell swelling. This increase in cell volume is followed by a regulatory volume decrease response (RVD, which is known to be partially mediated by the activation of K(+ and anion channels. However, the precise mechanisms underlying osmotic swelling and subsequent cell volume regulation in Müller cells have been evaluated by only a few studies. Although the activation of ion channels during the RVD response may alter transmembrane potential (Vm, no studies have actually addressed this issue in Müller cells. The aim of the present work is to evaluate RVD using a retinal Müller cell line (MIO-M1 under different extracellular ionic conditions, and to study a possible association between RVD and changes in Vm. Cell volume and Vm changes were evaluated using fluorescent probe techniques and a mathematical model. Results show that cell swelling and subsequent RVD were accompanied by Vm depolarization followed by repolarization. This response depended on the composition of extracellular media. Cells exposed to a hypoosmotic solution with reduced ionic strength underwent maximum RVD and had a larger repolarization. Both of these responses were reduced by K(+ or Cl(- channel blockers. In contrast, cells facing a hypoosmotic solution with the same ionic strength as the isoosmotic solution showed a lower RVD and a smaller repolarization and were not affected by blockers. Together, experimental and simulated data led us to propose that the efficiency of the RVD process in Müller glia depends not only on the activation of ion channels, but is also strongly modulated by concurrent changes in the membrane potential. The relationship between ionic fluxes, changes in ion permeabilities and ion concentrations -all leading to changes in Vm- define the success of RVD.

  9. Know your tools - concordance of different methods for measuring brain volume change after ischemic stroke

    Energy Technology Data Exchange (ETDEWEB)

    Yassi, Nawaf; Campbell, Bruce C.V.; Davis, Stephen M.; Bivard, Andrew [The University of Melbourne, Departments of Medicine and Neurology, Melbourne Brain Centre rate at The Royal Melbourne Hospital, Parkville, Victoria (Australia); Moffat, Bradford A.; Steward, Christopher; Desmond, Patricia M. [The University of Melbourne, Department of Radiology, The Royal Melbourne Hospital, Parkville (Australia); Churilov, Leonid [The University of Melbourne, The Florey Institute of Neurosciences and Mental Health, Parkville (Australia); Parsons, Mark W. [University of Newcastle and Hunter Medical Research Institute, Priority Research Centre for Translational Neuroscience and Mental Health, Newcastle (Australia)

    2015-07-15

    Longitudinal brain volume changes have been investigated in a number of cerebral disorders as a surrogate marker of clinical outcome. In stroke, unique methodological challenges are posed by dynamic structural changes occurring after onset, particularly those relating to the infarct lesion. We aimed to evaluate agreement between different analysis methods for the measurement of post-stroke brain volume change, and to explore technical challenges inherent to these methods. Fifteen patients with anterior circulation stroke underwent magnetic resonance imaging within 1 week of onset and at 1 and 3 months. Whole-brain as well as grey- and white-matter volume were estimated separately using both an intensity-based and a surface watershed-based algorithm. In the case of the intensity-based algorithm, the analysis was also performed with and without exclusion of the infarct lesion. Due to the effects of peri-infarct edema at the baseline scan, longitudinal volume change was measured as percentage change between the 1 and 3-month scans. Intra-class and concordance correlation coefficients were used to assess agreement between the different analysis methods. Reduced major axis regression was used to inspect the nature of bias between measurements. Overall agreement between methods was modest with strong disagreement between some techniques. Measurements were variably impacted by procedures performed to account for infarct lesions. Improvements in volumetric methods and consensus between methodologies employed in different studies are necessary in order to increase the validity of conclusions derived from post-stroke cerebral volumetric studies. Readers should be aware of the potential impact of different methods on study conclusions. (orig.)

  10. Volume-of-change cone-beam CT for image-guided surgery

    Science.gov (United States)

    Lee, Junghoon; Webster Stayman, J.; Otake, Yoshito; Schafer, Sebastian; Zbijewski, Wojciech; Khanna, A. Jay; Prince, Jerry L.; Siewerdsen, Jeffrey H.

    2012-08-01

    C-arm cone-beam CT (CBCT) can provide intraoperative 3D imaging capability for surgical guidance, but workflow and radiation dose are the significant barriers to broad utilization. One main reason is that each 3D image acquisition requires a complete scan with a full radiation dose to present a completely new 3D image every time. In this paper, we propose to utilize patient-specific CT or CBCT as prior knowledge to accurately reconstruct the aspects of the region that have changed by the surgical procedure from only a sparse set of x-rays. The proposed methods consist of a 3D-2D registration between the prior volume and a sparse set of intraoperative x-rays, creating digitally reconstructed radiographs (DRRs) from the registered prior volume, computing difference images by subtracting DRRs from the intraoperative x-rays, a penalized likelihood reconstruction of the volume of change (VOC) from the difference images, and finally a fusion of VOC reconstruction with the prior volume to visualize the entire surgical field. When the surgical changes are local and relatively small, the VOC reconstruction involves only a small volume size and a small number of projections, allowing less computation and lower radiation dose than is needed to reconstruct the entire surgical field. We applied this approach to sacroplasty phantom data obtained from a CBCT test bench and vertebroplasty data with a fresh cadaver acquired from a C-arm CBCT system with a flat-panel detector. The VOCs were reconstructed from a varying number of images (10-66 images) and compared to the CBCT ground truth using four different metrics (mean squared error, correlation coefficient, structural similarity index and perceptual difference model). The results show promising reconstruction quality with structural similarity to the ground truth close to 1 even when only 15-20 images were used, allowing dose reduction by the factor of 10-20.

  11. Changes in the temperature-dependent specific volume of supported polystyrene films with film thickness

    Science.gov (United States)

    Huang, Xinru; Roth, Connie B.

    2016-06-01

    Recent studies have measured or predicted thickness-dependent shifts in density or specific volume of polymer films as a possible means of understanding changes in the glass transition temperature Tg(h) with decreasing film thickness with some experimental works claiming unrealistically large (25%-30%) increases in film density with decreasing thickness. Here we use ellipsometry to measure the temperature-dependent index of refraction of polystyrene (PS) films supported on silicon and investigate the validity of the commonly used Lorentz-Lorenz equation for inferring changes in density or specific volume from very thin films. We find that the density (specific volume) of these supported PS films does not vary by more than ±0.4% of the bulk value for film thicknesses above 30 nm, and that the small variations we do observe are uncorrelated with any free volume explanation for the Tg(h) decrease exhibited by these films. We conclude that the derivation of the Lorentz-Lorenz equation becomes invalid for very thin films as the film thickness approaches ˜20 nm, and that reports of large density changes greater than ±1% of bulk for films thinner than this likely suffer from breakdown in the validity of this equation or in the difficulties associated with accurately measuring the index of refraction of such thin films. For larger film thicknesses, we do observed small variations in the effective specific volume of the films of 0.4 ± 0.2%, outside of our experimental error. These shifts occur simultaneously in both the liquid and glassy regimes uniformly together starting at film thicknesses less than ˜120 nm but appear to be uncorrelated with Tg(h) decreases; possible causes for these variations are discussed.

  12. Micro-Computed Tomography of Tooth Volume Changes Following Post Removal.

    Science.gov (United States)

    Kim, Jiyeon J; Alapati, Satish; Knoernschild, Kent L; Jeong, Yong-Hoon; Kim, Do Gyoon; Lee, Damian J

    2017-08-01

    To measure tooth volume change before and after post removal using micro-CT and to compare the difference among various combinations of prefabricated post and cement systems. Forty-eight extracted maxillary anterior teeth and mandibular canines were sectioned 13 mm from the apex. Root canals were properly instrumented. Preparations were filled with gutta percha using lateral condensation. Post space was prepared with a touch and heat device, leaving 5 mm of gutta percha from the apex. Specimens were scanned with micro-CT to establish objective baseline volume and divided into two groups of post systems: stainless steel (SS) ParaPost and glass-fiber reinforced composite (FRC) post. Half the posts for each group were cemented with Ketac Cem radiopaque glass-ionomer cement, and the other half with SpeedCEM dual-curing resin cement. The posts and residual cement were removed by the same operator, using the ultrasonic vibration technique under an endodontic operating microscope. The remaining tooth root structure was scanned again using micro-CT with volume reported (mm(3) ). The statistical difference between the combination of posts and cements was measured using the Kruskal-Wallis ANOVA test (α = 0.001). The independent variables were evaluated separately using post hoc Tukey examination to determine which groups resulted in a statistically significant difference. There was a statistical difference of tooth root volume change among the groups. Post hoc exam revealed a statistically significant difference in tooth root volume change between group 1 (SS + GI) and the other groups (α = 0.0002). Compared to other post and cement combinations, serrated parallel-sided SS posts cemented with GI cement had the most tooth root structure loss upon post removal using the ultrasonic vibration technique. © 2016 by the American College of Prosthodontists.

  13. Improving the clinical correlation of multiple sclerosis black hole volume change by paired-scan analysis.

    Science.gov (United States)

    Tam, Roger C; Traboulsee, Anthony; Riddehough, Andrew; Li, David K B

    2012-01-01

    The change in T 1-hypointense lesion ("black hole") volume is an important marker of pathological progression in multiple sclerosis (MS). Black hole boundaries often have low contrast and are difficult to determine accurately and most (semi-)automated segmentation methods first compute the T 2-hyperintense lesions, which are a superset of the black holes and are typically more distinct, to form a search space for the T 1w lesions. Two main potential sources of measurement noise in longitudinal black hole volume computation are partial volume and variability in the T 2w lesion segmentation. A paired analysis approach is proposed herein that uses registration to equalize partial volume and lesion mask processing to combine T 2w lesion segmentations across time. The scans of 247 MS patients are used to compare a selected black hole computation method with an enhanced version incorporating paired analysis, using rank correlation to a clinical variable (MS functional composite) as the primary outcome measure. The comparison is done at nine different levels of intensity as a previous study suggests that darker black holes may yield stronger correlations. The results demonstrate that paired analysis can strongly improve longitudinal correlation (from -0.148 to -0.303 in this sample) and may produce segmentations that are more sensitive to clinically relevant changes.

  14. Coupled Structural, Thermal, Phase-Change and Electromagnetic Analysis for Superconductors. Volume 1

    Science.gov (United States)

    Felippa, C. A.; Farhat, C.; Park, K. C.; Militello, C.; Schuler, J. J.

    1996-01-01

    Described are the theoretical development and computer implementation of reliable and efficient methods for the analysis of coupled mechanical problems that involve the interaction of mechanical, thermal, phase-change and electromagnetic subproblems. The focus application has been the modeling of superconductivity and associated quantum-state phase-change phenomena. In support of this objective the work has addressed the following issues: (1) development of variational principles for finite elements, (2) finite element modeling of the electromagnetic problem, (3) coupling of thermal and mechanical effects, and (4) computer implementation and solution of the superconductivity transition problem. The main accomplishments have been: (1) the development of the theory of parametrized and gauged variational principles, (2) the application of those principled to the construction of electromagnetic, thermal and mechanical finite elements, and (3) the coupling of electromagnetic finite elements with thermal and superconducting effects, and (4) the first detailed finite element simulations of bulk superconductors, in particular the Meissner effect and the nature of the normal conducting boundary layer. The theoretical development is described in two volumes. This volume, Volume 1, describes mostly formulations for specific problems. Volume 2 describes generalization of those formulations.

  15. Change in corneal curvature induced by surgery

    NARCIS (Netherlands)

    G. van Rij (Gabriel)

    1987-01-01

    textabstractThe first section deals with the mechanisms by which sutures, incisions and intracorneal contact lenses produce a change in corneal curvature. To clarify the mechanisms by which incisions and sutures produce astigmatism, we made incisions and placed sutures in the corneoscleral limbus of

  16. 2,3-Dihydroxybenzoic acid attenuates kanamycin-induced volume reduction in mouse utricular type I hair cells

    DEFF Research Database (Denmark)

    Severinsen, Stig Åvall; Kirkegaard, Mette; Nyengaard, Jens Randel

    2006-01-01

    injection. Total volume of the utricle, as well as total number of hair and supporting cells, were estimated on light microscopic sections. Total volume and mean volume of hair cell types I and II and supporting cells were estimated on digital transmission electron micrographs. Total volume of the utricular...... macula, hair cell type I and supporting cells decreased significantly in animals injected with kanamycin but not in animals co-treated with DHB. Hair and supporting cell numbers remained unchanged in all three groups. In conclusion, the kanamycin-induced volume reduction of type I hair cells...

  17. Stereological brain volume changes in post-weaned socially isolated rats

    DEFF Research Database (Denmark)

    Fabricius, Katrine; Helboe, Lone; Steiniger-Brach, Björn;

    2010-01-01

    have evaluated the neuroanatomical changes in this animal model in comparison to changes seen in schizophrenia. In this study, we applied stereological volume estimates to evaluate the total brain, the ventricular system, and the pyramidal and granular cell layers of the hippocampus in male and female...... Lister Hooded rats isolated from postnatal day 25 for 15 weeks. We observed the expected gender differences in total brain volume with males having larger brains than females. Further, we found that isolated males had significantly smaller brains than group-housed controls and larger lateral ventricles...... than controls. However, this was not seen in female rats. Isolated males had a significant smaller hippocampus, dentate gyrus and CA2/3 where isolated females had a significant smaller CA1 compared to controls. Thus, our results indicate that long-term isolation of male rats leads to neuroanatomical...

  18. Vanishing linear term in chemical potential difference in volume term of work of critical nucleus formation for phase transition without volume change

    CERN Document Server

    Mori, Atsushi

    2013-01-01

    A question is given on the form n({\\mu}_{\\beta}-{\\mu}_{\\alpha}) for the volume term of work of formation of critical nucleus. Here, n is the number of molecule undergone the phase transition, {\\mu} denotes the chemical potential, {\\alpha} and {\\beta} represent the parent and nucleating phases, respectively. In this paper we concentrate phase transition without volume change. We have calculated the volume term in terms of the chemical potential difference {\\mu}_{re}-{\\mu}_{eq}$ for this case. Here, {\\mu}_{re} is the chemical potential of the reservoir and {\\mu}_{eq} that at the phase transition. We have W_{vol} = -[({\\kappa}_{\\beta}-{\\kappa}_{\\alpha})/(2v_{eq}^2)] ({\\mu}_{re}-{\\mu}_{eq})^2 V_{\\beta} with {\\kappa} denoting the isothermal compressibility, v_{eq} being the molecular volume at the phase transition, V_{\\beta} the volume of the nucleus.

  19. Detection of Greenhouse-Gas-Induced Climatic Change

    Energy Technology Data Exchange (ETDEWEB)

    Jones, P.D.; Wigley, T.M.L.

    1998-05-26

    The objective of this report is to assemble and analyze instrumental climate data and to develop and apply climate models as a basis for (1) detecting greenhouse-gas-induced climatic change, and (2) validation of General Circulation Models.

  20. Phytopathogen-induced changes to plant methylomes.

    Science.gov (United States)

    Hewezi, Tarek; Pantalone, Vince; Bennett, Morgan; Neal Stewart, C; Burch-Smith, Tessa M

    2017-07-29

    DNA methylation is a dynamic and reversible type of epigenetic mark that contributes to cellular physiology by affecting transcription activity, transposon mobility and genome stability. When plants are infected with pathogens, plant DNA methylation patterns can change, indicating an epigenetic interplay between plant host and pathogen. In most cases methylation can change susceptibility. While DNA hypomethylation appears to be a common phenomenon during the susceptible interaction, the levels and patterns of hypomethylation in transposable elements and genic regions may mediate distinct responses against various plant pathogens. The effect of DNA methylation on the plant immune response and other cellular activities and molecular functions is established by localized differential DNA methylation via cis-regulatory mechanisms as well as through trans-acting mechanisms. Understanding the epigenetic differences that control the phenotypic variations between susceptible and resistant interactions should facilitate the identification of new sources of resistance mediated by epigenetic mechanisms, which can be exploited to endow pathogen resistance to crops.

  1. Evaluative conditioning induces changes in sound valence

    Directory of Open Access Journals (Sweden)

    Anna C. Bolders

    2012-04-01

    Full Text Available Evaluative Conditioning (EC has hardly been tested in the auditory domain, but it is a potentially valuable research tool. In Experiment 1 we investigated whether the affective evaluation of short environmental sounds can be changed using affective words as unconditioned stimuli (US. Congruence effects on an affective priming task (APT for conditioned sounds demonstrated successful EC. Subjective ratings for sounds paired with negative words changed accordingly. In Experiment 2 we investigated whether the acquired valence remains stable after repeated presentation of the conditioned sound without the US or whether extinction occurs. The acquired affective value remained present, albeit weaker, even after 40 extinction trials. These results warrant the use of EC to study processing of short environmental sounds with acquired valence, even if this requires repeated stimulus presentations. This paves the way for studying processing of affective environmental sounds while effectively controlling low level-stimulus properties.

  2. Low Temperature Induced Conformation Changes of Aminoacylase

    Institute of Scientific and Technical Information of China (English)

    谢强; 孟凡国; 周海梦

    2004-01-01

    Control of aggregation, by lowering temperature and protein concentrations, can enhance the extent of successful refolding. The low temperature has been used in protein folding studies, as undesired aggregations often occur at higher temperatures. Therefore, it is very important to study the effects of low temperature on the native enzyme to help understand the factors that affect the structure of the proteins. In this paper, aminoacylase was studied at different temperatures by measuring enzyme activity, fluorescence emission spectra, and ultraviolet difference spectra. The results show that aminoacylase conformation changes as the temperature changes, becoming more compact at low temperatures, and having more secondary structural content. However, the activity is very low at low temperature, and totally diminishes at 4℃. Aminoacylase tends therefore to be more condense, with less residues exposed and low enzyme activities at low temperature. This observation might explain the self-protection of organisms under conditions of extreme temperature.

  3. Universal convergence of the specific volume changes of globular proteins upon unfolding.

    Science.gov (United States)

    Schweiker, Katrina L; Fitz, Victoria W; Makhatadze, George I

    2009-11-24

    Both pressure and temperature are important environmental variables, and to obtain a complete understanding of the mechanisms of protein folding, it is necessary to determine how protein stability is dependent on these fundamental thermodynamic parameters. Although the temperature dependence of protein stability has been widely explored, the dependence of protein stability on pressure is not as well studied. In this paper, we report the results of the direct thermodynamic determination of the change in specific volume (DeltaV/V) upon protein unfolding, which defines the pressure dependence of protein stability, for five model proteins (ubiquitin, eglin c, ribonuclease A, lysozyme, and cytochrome c). We have shown that the specific volumetric changes upon unfolding for four of the proteins (ubiquitin, eglin c, ribonuclease A, and lysozyme) appear to converge to a common value at high temperatures. Analysis of various contributions to the change in volume upon protein unfolding allowed us to put forth the hypothesis that the change in volume due to hydration is very close to zero at this temperature, such that DeltaV/V is defined largely by the total volume of cavities and voids within a protein, and that this is a universal property of all small globular proteins without prosthetic groups. To test this hypothesis, additional experiments were performed with variants of eglin c that had site-directed substitutions at two buried positions, to create an additional cavity in the protein core. The results of these experiments, coupled with the structural analysis of cytochrome c showing a lower packing density compared to those of the other four proteins, provided further support for the hypothesis. Finally, we have shown that the deviation of the high-temperature DeltaV value of a given protein from the convergence value can be used to determine the size of the excess cavities in globular proteins.

  4. Radiation-Induced Changes in Serum Lipidome of Head and Neck Cancer Patients

    Directory of Open Access Journals (Sweden)

    Karol Jelonek

    2014-04-01

    Full Text Available Cancer radiotherapy (RT induces response of the whole patient’s body that could be detected at the blood level. We aimed to identify changes induced in serum lipidome during RT and characterize their association with doses and volumes of irradiated tissue. Sixty-six patients treated with conformal RT because of head and neck cancer were enrolled in the study. Blood samples were collected before, during and about one month after the end of RT. Lipid extracts were analyzed using MALDI-oa-ToF mass spectrometry in positive ionization mode. The major changes were observed when pre-treatment and within-treatment samples were compared. Levels of several identified phosphatidylcholines, including (PC34, (PC36 and (PC38 variants, and lysophosphatidylcholines, including (LPC16 and (LPC18 variants, were first significantly decreased and then increased in post-treatment samples. Intensities of changes were correlated with doses of radiation received by patients. Of note, such correlations were more frequent when low-to-medium doses of radiation delivered during conformal RT to large volumes of normal tissues were analyzed. Additionally, some radiation-induced changes in serum lipidome were associated with toxicity of the treatment. Obtained results indicated the involvement of choline-related signaling and potential biological importance of exposure to clinically low/medium doses of radiation in patient’s body response to radiation.

  5. Accounting for uncertainty in volumes of seabed change measured with repeat multibeam sonar surveys

    Science.gov (United States)

    Schimel, Alexandre C. G.; Ierodiaconou, Daniel; Hulands, Lachlan; Kennedy, David M.

    2015-12-01

    Seafloors of unconsolidated sediment are highly dynamic features; eroding or accumulating under the action of tides, waves and currents. Assessing which areas of the seafloor experienced change and measuring the corresponding volumes involved provide insights into these important active sedimentation processes. Computing the difference between Digital Elevation Models (DEMs) obtained from repeat Multibeam Echosounders (MBES) surveys has become a common technique to identify these areas, but the uncertainty in these datasets considerably affects the estimation of the volumes displaced. The two main techniques used to take into account uncertainty in volume estimations are the limitation of calculations to areas experiencing a change in depth beyond a chosen threshold, and the computation of volumetric confidence intervals. However, these techniques are still in their infancy and, as a result, are often crude, seldom used or poorly understood. In this article, we explored a number of possible methodological advances to address this issue, including: (1) using the uncertainty information provided by the MBES data processing algorithm CUBE, (2) adapting fluvial geomorphology techniques for volume calculations using spatially variable thresholds and (3) volumetric histograms. The nearshore seabed off Warrnambool harbour - located in the highly energetic southwest Victorian coast, Australia - was used as a test site. Four consecutive MBES surveys were carried out over a four-months period. The difference between consecutive DEMs revealed an area near the beach experiencing large sediment transfers - mostly erosion - and an area of reef experiencing increasing deposition from the advance of a nearby sediment sheet. The volumes of sediment displaced in these two areas were calculated using the techniques described above, both traditionally and using the suggested improvements. We compared the results and discussed the applicability of the new methodological improvements

  6. Brain gray matter volume changes associated with motor symptoms in patients with Parkinson's disease

    Institute of Scientific and Technical Information of China (English)

    Dezhi Kang; Fuyong Chen; Fangyu Wang; Guorong Wu; Ying Liu; Gang Wu; Lianghong Yu

    2016-01-01

    Background:Parkinson's disease (PD) is a common neurodegenerative disease.Most studies have found that the histopathological lesion is not only localized at the extrapyramidal area (basal ganglia) but also at the cortex in PD patients.Voxel-based morphometry (VBM) based on the voxel as a unit is described for quantitative detection of density and volume of brain tissue.In this study,VBM was used to investigate the brain gray matter changes associated with motor symptoms in PD patients.Methods:Twelve outpatients with PD and 12 healthy controls were recruited in our hospital from September 2013 to March 2014.VBM was performed on the whole brain of all subjects.Image processing and statistical analysis were performed using SPM8.A two-sample t test and multiple regression analysis were performed.Results were displayed with a threshold of P < 0.01,corrected by false discovery rate (FDR) correction and cluster size >30 voxels.Results:Comparing control healthy subjects with the patients,the data showed that PD patients had reduced gray matter volume in the postcentral gyrus,the right supramarginal center,superior temporal gyrus,precentral gyrus,Brodmann area 41,transverse temporal gyrus,Brodmann area 3,and inferior parietal Iobule.The data also found that between gray matter volume and UPDRSIII in PD patients,there were negative correlations in the right middle frontal gyrus,BA06,right precentral gyrus,right superior frontal gyrus,and medial frontal gyrus,and between gray matter volume and Hoehn-Yahr (HY) in PD patients,there were negative correlations in the right middle frontal gyrus,right superior frontal gyrus,BA6,and right precentral gyrus.Conclusions:These data supported that extensive changes associated with motor symptoms in the gray matter volume was mainly located in the related area of movement,which had obvious relevance with the progression of PD.

  7. Hippocampal volume changes in healthy subjects at risk of unipolar depression

    DEFF Research Database (Denmark)

    Baaré, William F C; Vinberg, Maj; Knudsen, Gitte M

    2010-01-01

    Unipolar depression is moderately heritable. It is unclear whether structural brain changes associated with unipolar depression are present in healthy persons at risk of the disorder. Here we investigated whether a genetic predisposition to unipolar depression is associated with structural brain...... changes. A priori, hippocampal volume reductions were hypothesized. Using a high-risk study design, magnetic resonance imaging brain scans were obtained from 59 healthy high-risk subjects having a co-twin with unipolar depression, and 53 healthy low-risk subjects without a first-degree family history...

  8. Heteromeric Slick/Slack K+ channels show graded sensitivity to cell volume changes

    DEFF Research Database (Denmark)

    Tejada, Maria A; Hashem, Nadia; Callø, Kirstine

    2017-01-01

    Slick and Slack high-conductance K+ channels are found in the CNS, kidneys, pancreas, among other organs, where they play an important role in cell excitability as well as in ion transport processes. They are both activated by Na+ and Cl- but show a differential regulation by cell volume changes...... to osmotic challenges. In order to provide with the adequate water permeability to the cell membrane of Xenopus laevis oocytes, mRNA of aquaporin 1 was co-expressed with homomeric or heteromeric Slick and Slack α-subunits. Oocytes were superfused with hypotonic or hypertonic buffers and changes in currents...

  9. Volume and enthalpy changes of proton transfers in the bacteriorhodopsin photocycle studied by millisecond time-resolved photopressure measurements.

    Science.gov (United States)

    Liu, Yan; Edens, Gregory J; Grzymski, Joseph; Mauzerall, David

    2008-07-22

    The volume and enthalpy changes associated with proton translocation steps during the bacteriorhodopsin (BR) photocycle were determined by time-resolved photopressure measurements. The data at 25 degrees C show a prompt increase in volume followed by two further increases and one decrease to the original state to complete the cycle. These volume changes are decomposed into enthalpy and inherent volume changes. The positive enthalpy changes support the argument for inherent entropy-driven late steps in the BR photocycle [Ort, D. R., and Parson, W. M. (1979) Enthalpy changes during the photochemical cycle of bacteriorhodopsin. Biophys. J. 25, 355-364]. The volume change data can be interpreted by the electrostriction effect as charges are canceled and formed during the proton transfers. A simple glutamic acid-glutamate ion model or a diglutamate-arginine-protonated water charge-delocalized model for the proton-release complex (PRC) fit the data. A conformational change with a large positive volume change is required in the slower rise (M --> N of the optical cycle) step and is reversed in the decay (N --> O --> BR) steps. The large variation in the published values for both the volume and enthalpy changes is greatly ameliorated if the values are presented per absorbed photon instead of per mole of BR. Thus, it is the highly differing assumptions about the quantum or reaction yields that cause the variations in the published results.

  10. Settlements in unsaturated granular soils induced by changes in saturation and suction

    Directory of Open Access Journals (Sweden)

    Milatz Marius

    2016-01-01

    Full Text Available In this contribution the hydro-mechanically coupled behaviour of a sand is experimentally investigated with the focus on settlements induced by changes in degree of saturation and suction. This phenomenon, referred to as collapse behaviour, is attributed to rearrangements of the grain skeleton due to changing capillary effects on wetting of the soil. For the experimental investigation of the collapse behaviour of a medium coarse sand cyclic drying-wetting tests are performed under oedometric conditions. In the test set-up a sand specimen, subjected to a constant small vertical stress, is cyclically dried and wetted by volume control of the pore water, whereas matric suction is measured using a tensiometer implemented to the specimen loading plate (topcap tensiometer. The test procedure, originally designed to investigate the hysteretic nature of the soil-water characteristic curve of the sand, allows to measure the one dimensional volume change of the specimen as evoked by the applied hydraulic paths under constant net stress. By varying the specimen void ratio the impact of density on the collapse behaviour can be assessed. The test data is important for the development of a mechanical constitutive model which can take the volume change behaviour due to suction changes into account.

  11. Volume changes in Alzheimer's disease and mild cognitive impairment: cognitive associations

    Energy Technology Data Exchange (ETDEWEB)

    Evans, Matthew C.; Barnes, Josephine; Nielsen, Casper; Clegg, Shona L.; Blair, Melanie; Douiri, Abdel; Boyes, Richard G.; Fox, Nick C. [UCL Institute of Neurology, Dementia Research Centre, London (United Kingdom); Kim, Lois G. [UCL Institute of Neurology, Dementia Research Centre, London (United Kingdom); London School of Hygiene and Tropical Medicine, London (United Kingdom); Leung, Kelvin K.; Ourselin, Sebastien [UCL Institute of Neurology, Dementia Research Centre, London (United Kingdom); University College London, Centre for Medical Image Computing, London (United Kingdom)

    2010-03-15

    To assess the relationship between MRI-derived changes in whole-brain and ventricular volume with change in cognitive scores in Alzheimer's disease (AD), mild cognitive impairment (MCI) and control subjects. In total 131 control, 231 MCI and 99 AD subjects from the Alzheimer's Disease Neuroimaging Initiative (ADNI) cohort with T1-weighted volumetric MRIs from baseline and 12-month follow-up were used to derive volume changes. Mini mental state examination (MMSE), Alzheimer's disease assessment scale (ADAS)-cog and trails test changes were calculated over the same period. Brain atrophy rates and ventricular enlargement differed between subject groups (p < 0.0005) and in MCI and AD were associated with MMSE changes. Both measures were additionally associated with ADAS-cog and trails-B in MCI patients, and ventricular expansion was associated with ADAS-cog in AD patients. Brain atrophy (p < 0.0005) and ventricular expansion rates (p = 0.001) were higher in MCI subjects who progressed to AD within 12 months of follow-up compared with MCI subjects who remained stable. MCI subjects who progressed to AD within 12 months had similar atrophy rates to AD subjects. Whole-brain atrophy rates and ventricular enlargement differed between patient groups and healthy controls, and tracked disease progression and psychological decline, demonstrating their relevance as biomarkers. (orig.)

  12. Head posture and pharyngeal airway volume changes after bimaxillary surgery for mandibular prognathism.

    Science.gov (United States)

    Kim, Min-Ah; Kim, Bo-Ram; Youn, Jong-Kuk; Kim, Yoon-Ji R; Park, Yang-Ho

    2014-07-01

    The purpose of this study was to evaluate head posture and the pharyngeal airway volume changes using 3D imaging after bimaxillary surgery in mandibular prognathism patients by null hypothesis. Cone-beam computed tomography (CBCT) scans were obtained for 25 mandibular prognathism patients before bimaxillary surgery (T1) and 6 months after surgery (T2). The head posture of each patient was assessed by measuring cranio-cervical angle on a midsagittal plane passing through the anterior nasal spine at T1 and T2. Additionally, the volume of each subject's pharyngeal airway was measured using InVivoDental 3D imaging software. The cranio-cervical angle increased significantly 6 months after bimaxillary surgery (p  0.05) at the same timepoints, while naso- and oro-pharyngeal airway volume decreased significantly (p Bimaxillary surgery resulted in significant head flexion and a slight decrease in total pharyngeal airway volume. Copyright © 2013 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  13. Dynamic volume changes in astrocytes are an intrinsic phenomenon mediated by bicarbonate ion flux.

    Directory of Open Access Journals (Sweden)

    Clare M Florence

    Full Text Available Astrocytes, the major type of non-neuronal cells in the brain, play an important functional role in extracellular potassium ([K(+](o and pH homeostasis. Pathological brain states that result in [K(+](o and pH dysregulation have been shown to cause astrocyte swelling. However, whether astrocyte volume changes occur under physiological conditions is not known. In this study we used two-photon imaging to visualize real-time astrocyte volume changes in the stratum radiatum of the hippocampus CA1 region. Astrocytes were observed to swell by 19.0±0.9% in response to a small physiological increase in the concentration of [K(+](o (3 mM. Astrocyte swelling was mediated by the influx of bicarbonate (HCO(3- ions as swelling was significantly decreased when the influx of HCO(3- was reduced. We found: 1 in HCO(3- free extracellular solution astrocytes swelled by 5.4±0.7%, 2 when the activity of the sodium-bicarbonate cotransporter (NBC was blocked the astrocytes swelled by 8.3±0.7%, and 3 in the presence of an extracellular carbonic anhydrase (CA inhibitor astrocytes swelled by 11.4±0.6%. Because a significant HCO(3- efflux is known to occur through the γ-amino-butyric acid (GABA channel, we performed a series of experiments to determine if astrocytes were capable of HCO(3- mediated volume shrinkage with GABA channel activation. Astrocytes were found to shrink -7.7±0.5% of control in response to the GABA(A channel agonist muscimol. Astrocyte shrinkage from GABA(A channel activation was significantly decreased to -5.0±0.6% of control in the presence of the membrane-permeant CA inhibitor acetazolamide (ACTZ. These dynamic astrocyte volume changes may represent a previously unappreciated yet fundamental mechanism by which astrocytes regulate physiological brain functioning.

  14. CT-measured regional specific volume change reflects regional ventilation in supine sheep.

    Science.gov (United States)

    Fuld, Matthew K; Easley, R Blaine; Saba, Osama I; Chon, Deokiee; Reinhardt, Joseph M; Hoffman, Eric A; Simon, Brett A

    2008-04-01

    Computer tomography (CT) imaging techniques permit the noninvasive measurement of regional lung function. Regional specific volume change (sVol), determined from the change in lung density over a tidal breath, should correlate with regional ventilation and regional lung expansion measured with other techniques. sVol was validated against xenon (Xe)-CT-specific ventilation (sV) in four anesthetized, intubated, mechanically ventilated sheep. Xe-CT used expiratory gated axial scanning during the washin and washout of 55% Xe. sVol was measured from the tidal changes in tissue density (H, houndsfield units) of lung regions using the relationship sVol = [1,000(Hi - He)]/[He(1,000 + Hi)], where He and Hi are expiratory and inspiratory regional density. Distinct anatomical markings were used to define corresponding lung regions of interest between inspiratory, expiratory, and Xe-CT images, with an average region of interest size of 1.6 +/- 0.7 ml. In addition, sVol was compared with regional volume changes measured directly from the positions of implanted metal markers in an additional animal. A linear relationship between sVol and sV was demonstrated over a wide range of regional sV found in the normal supine lung, with an overall correlation coefficient (R(2)) of 0.66. There was a tight correlation (R(2) = 0.97) between marker-measured volume changes and sVol. Regional sVol, which involves significantly reduced exposure to radiation and Xe gas compared with the Xe-CT method, represents a safe and efficient surrogate for measuring regional ventilation in experimental studies and patients.

  15. International conference on the role of the polar regions in global change: Proceedings. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Weller, G.; Wilson, C.L.; Severin, B.A.B. [eds.

    1991-12-01

    The International Conference on the Role of the Polar Regions in Global Change took place on the campus of the University of Alaska Fairbanks on June 11--15, 1990. The goal of the conference was to define and summarize the state of knowledge on the role of the polar regions in global change, and to identify gaps in knowledge. To this purpose experts in a wide variety of relevant disciplines were invited to present papers and hold panel discussions. While there are numerous conferences on global change, this conference dealt specifically with polar regions which occupy key positions in the global system. These two volumes of conference proceedings include papers on (1) detection and monitoring of change; (2) climate variability and climate forcing; (3) ocean, sea ice, and atmosphere interactions and processes; (4) effects on biota and biological feedbacks; (5) ice sheet, glacier and permafrost responses and feedbacks; (6) paleoenvironmental studies; and, (7) aerosols and trace gases.

  16. International conference on the role of the polar regions in global change: Proceedings. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Weller, G.; Wilson, C.L.; Severin, B.A.B. [eds.

    1991-12-01

    The International Conference on the Role of the Polar Regions in Global Change took place on the campus of the University of Alaska Fairbanks on June 11--15, 1990. The goal of the conference was to define and summarize the state of knowledge on the role of the polar regions in global change, and to identify gaps in knowledge. To this purpose experts in a wide variety of relevant disciplines were invited to present papers and hold panel discussions. While there are numerous conferences on global change, this conference dealt specifically with the polar regions which occupy key positions in the global system. These two volumes of conference proceedings include papers on (1) detection and monitoring of change; (2) climate variability and climate forcing; (3) ocean, sea ice, and atmosphere interactions and processes; and (4) effects on biota and biological feedbacks; (5) ice sheet, glacier and permafrost responses and feedbacks, (6) paleoenvironmental studies; and, (7) aerosol and trace gases.

  17. Brain oscillations in bipolar disorder and lithium-induced changes.

    Science.gov (United States)

    Atagün, Murat İlhan

    2016-01-01

    Electroencephalography (EEG) studies in patients with bipolar disorder have revealed lower amplitudes in brain oscillations. The aim of this review is to describe lithium-induced EEG changes in bipolar disorder and to discuss potential underlying factors. A literature survey about lithium-induced EEG changes in bipolar disorder was performed. Lithium consistently enhances magnitudes of brain oscillations in slow frequencies (delta and theta) in both resting-state EEG studies as well as event-related oscillations studies. Enhancement of magnitudes of beta oscillations is specific to event-related oscillations. Correlation between serum lithium levels and brain oscillations has been reported. Lithium-induced changes in brain oscillations might correspond to lithium-induced alterations in neurotransmitters, signaling cascades, plasticity, brain structure, or biophysical properties of lithium. Therefore, lithium-induced changes in brain oscillations could be promising biomarkers to assess the molecular mechanisms leading to variability in efficacy. Since the variability of lithium response in bipolar disorder is due to the genetic differences in the mechanisms involving lithium, it would be highly promising to assess the lithium-induced EEG changes as biomarkers in genetic studies.

  18. Forecasting Climate-Induced Ecosystem Changes on Military Installations

    Science.gov (United States)

    James D. Westervelt; William W. Hargrove

    2011-01-01

    Military installation training lands must be managed to support species at risk as well as to be effective training environments for soldiers. Forecasts from various global climate change models suggest that the habitats associated with some military training installations will face pressures that induce biome-shifts, invasive species, loss of habitat, and changes in...

  19. Thermally induced structural changes in coal combustion

    Energy Technology Data Exchange (ETDEWEB)

    Gavalas, G.R.; Flagan, R.C.

    1990-01-17

    The effect of particle shape on char burnout is investigated in the limit of shrinking core combustion. As a first step, the particle temperature is assumed to proceed in the shrinking core regime and under conditions of negligible Stefan flow. The problem then reduces to calculating the oxygen concentration field around a non-spherical particle with the oxidation reaction taking place on the external surface. This problem has been addressed by an analytical technique and a numerical technique. An analytical technique known as domain perturbation'' was used to examine the change due to reaction in the shape of a slightly nonspherical, but axisymmetric, particle. It was found that the aspect ratio always increases with conversion, i.e., the particle becomes less spherical. A numerical technique, based on the boundary integral'' method was developed to handle the case of an axisymmetric particle with otherwise arbitrary shape. Numerical results are presented which again show the aspect ratio to increase with conversion. 8 refs.

  20. Amiodarone Induced Morphological Changes in Rabbit Pneumocytes

    Directory of Open Access Journals (Sweden)

    Fereshteh Mehraein

    2009-01-01

    Full Text Available Objective: Amiodarone as an iodinated benzofuran derivative is a potent antiarrhythmicagent currently used for the treatment of ventricular arrhythmias. Pulmonary toxicityis one of the complications of Amiodarone therapy. The aim of this study was todetermine the toxicity of Amiodarone for pneumocytes.Materials and Methods: 14 male white New Zealand rabbits were divided in a controlgroup and an experimental group. The experimental group was subjected to intraperitoneal injection with a single daily dose of 80 mg/kg Amiodarone for two weeks.The control group received only normal saline. At the end of the injection period, thetwo groups were anesthetized and perfused with Karnovsky fixative. The lung tissuewas removed and fixed, then prepared for light and electron microscope studies.Morphometric studies were made on sections to find nucleus profile dimensions.Results: Light microscope observation showed acute changes in the alveolus includingcongestion of alveolar capillaries and infiltration of red blood cells (RBCs intothe lumen of the alveoli. Electron microscope study of lung tissue revealed abnormalinclusion bodies within type ΙΙ & Ι pneumocytes. The micrographs also showedthe presence of vacuoles in 5% of the type ΙΙ pneumocytes. Morphometric studiesshowed that the nucleus of the cells in the experimental group were smaller than inthe control group (p<0.01.Conclusion: These results indicate that Amiodarone administration can cause damageto pnuemocytes and the alveolus of rabbit lung, so the effectiveness of Amiodaronein long term treatment of heart failure patients is limited because of the developmentof lung toxicity.

  1. Process-induced compositional changes of flaxseed.

    Science.gov (United States)

    Wanasundara, P K; Shahidi, F

    1998-01-01

    Flaxseed has been used as an edible grain in different parts of the world since ancient times. However, use of flaxseed oil has been limited due to its high content of polyunsaturated fatty acids. Nonetheless, alpha-linolenic acid, dietary fiber and lignans of flaxseed have regained attention. New varieties of flaxseed containing low levels of alpha-linolenic acid are available for edible oil extraction. Use of whole flaxseed in foods provides a means to utilise all of its nutrients and require minimum processing steps. However, the presence of cyanogenic glucosides and diglucosides in the seeds is a concern as they may release cyanide upon hydrolysis. In addition, the polyunsaturated fatty acids may undergo thermal or autooxidation when exposed to air or high temperatures that are used in food preparation. Studies todate on oxidation products of intact flaxseed lipids have not shown any harmful effects when flaxseed is included, up to 28%, in the baked products. Furthermore, cyanide levels produced as a result of autolysis are below the harmful limits to humans. However, the meals left after oil extraction require detoxification but, by solvent extraction, to reduce the harmful effects of cyanide when used in animal rations. Flaxseed meal is a good source of proteins; these could be isolated by complexation with sodium hexametaphosphate without changing their nutritional value or composition. In addition, the effect of germination on proteins, lipids, cyanogenic glycosides, and other minor constituents of flaxseed is discussed.

  2. Coupled Structural, Thermal, Phase-change and Electromagnetic Analysis for Superconductors, Volume 2

    Science.gov (United States)

    Felippa, C. A.; Farhat, C.; Park, K. C.; Militello, C.; Schuler, J. J.

    1996-01-01

    Described are the theoretical development and computer implementation of reliable and efficient methods for the analysis of coupled mechanical problems that involve the interaction of mechanical, thermal, phase-change and electromag subproblems. The focus application has been the modeling of superconductivity and associated quantum-state phase change phenomena. In support of this objective the work has addressed the following issues: (1) development of variational principles for finite elements, (2) finite element modeling of the electromagnetic problem, (3) coupling of thermel and mechanical effects, and (4) computer implementation and solution of the superconductivity transition problem. The main accomplishments have been: (1) the development of the theory of parametrized and gauged variational principles, (2) the application of those principled to the construction of electromagnetic, thermal and mechanical finite elements, and (3) the coupling of electromagnetic finite elements with thermal and superconducting effects, and (4) the first detailed finite element simulations of bulk superconductors, in particular the Meissner effect and the nature of the normal conducting boundary layer. The theoretical development is described in two volumes. Volume 1 describes mostly formulation specific problems. Volume 2 describes generalization of those formulations.

  3. Function of cGMP-dependent protein kinase II in volume load-induced diuresis.

    Science.gov (United States)

    Schramm, Andrea; Schinner, Elisabeth; Huettner, Johannes P; Kees, Frieder; Tauber, Philipp; Hofmann, Franz; Schlossmann, Jens

    2014-10-01

    Atrial natriuretic peptide (ANP)/cGMPs cause diuresis and natriuresis. Their downstream effectors beyond cGMP remain unclear. To elucidate a probable function of cGMP-dependent protein kinase II (cGKII), we investigated renal parameters in different conditions (basal, salt diets, starving, water load) using a genetically modified mouse model (cGKII-KO), but did not detect any striking differences between WT and cGKII-KO. Thus, cGKII is proposed to play only a marginal role in the adjustment of renal concentration ability to varying salt loads without water restriction or starving conditions. When WT mice were subjected to a volume load (performed by application of a 10-mM glucose solution (3% of BW) via feeding needle), they exhibited a potent diuresis. In contrast, urine volume was decreased significantly in cGKII-KO. We showed that AQP2 plasma membrane (PM) abundance was reduced for about 50% in WT upon volume load, therefore, this might be a main cause for the enhanced diuresis. In contrast, cGKII-KO mice almost completely failed to decrease AQP2-PM distribution. This significant difference between both genotypes is not induced by an altered p-Ser256-AQP2 phosphorylation, as phosphorylation at this site decreases similarly in WT and KO. Furthermore, sodium excretion was lowered in cGKII-KO mice during volume load. In summary, cGKII is only involved to a minor extent in the regulation of basal renal concentration ability. By contrast, cGKII-KO mice are not able to handle an acute volume load. Our results suggest that membrane insertion of AQP2 is inhibited by cGMP/cGKII.

  4. Glacier Volume Change Estimation Using Time Series of Improved Aster Dems

    Science.gov (United States)

    Girod, Luc; Nuth, Christopher; Kääb, Andreas

    2016-06-01

    Volume change data is critical to the understanding of glacier response to climate change. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) system embarked on the Terra (EOS AM-1) satellite has been a unique source of systematic stereoscopic images covering the whole globe at 15m resolution and at a consistent quality for over 15 years. While satellite stereo sensors with significantly improved radiometric and spatial resolution are available to date, the potential of ASTER data lies in its long consistent time series that is unrivaled, though not fully exploited for change analysis due to lack of data accuracy and precision. Here, we developed an improved method for ASTER DEM generation and implemented it in the open source photogrammetric library and software suite MicMac. The method relies on the computation of a rational polynomial coefficients (RPC) model and the detection and correction of cross-track sensor jitter in order to compute DEMs. ASTER data are strongly affected by attitude jitter, mainly of approximately 4 km and 30 km wavelength, and improving the generation of ASTER DEMs requires removal of this effect. Our sensor modeling does not require ground control points and allows thus potentially for the automatic processing of large data volumes. As a proof of concept, we chose a set of glaciers with reference DEMs available to assess the quality of our measurements. We use time series of ASTER scenes from which we extracted DEMs with a ground sampling distance of 15m. Our method directly measures and accounts for the cross-track component of jitter so that the resulting DEMs are not contaminated by this process. Since the along-track component of jitter has the same direction as the stereo parallaxes, the two cannot be separated and the elevations extracted are thus contaminated by along-track jitter. Initial tests reveal no clear relation between the cross-track and along-track components so that the latter seems not to be

  5. Mapping the Ca2+ induced structural change in calreticulin

    DEFF Research Database (Denmark)

    Boelt, Sanne Grundvad; Norn, Christoffer; Rasmussen, Morten Ib

    2016-01-01

    (2+). The conformational changes induced by Ca(2+) have not been determined yet as they are hard to study with traditional approaches. Here, we investigated the Ca(2+)-induced conformational changes with a combination of chemical cross-linking, mass spectrometry, bioinformatics analysis and modelling...... in Rosetta. Using a bifunctional linker, we found a large Ca(2+)-induced change to the cross-linking pattern in calreticulin. Our results are consistent with a high flexibility in the P-loop, a stabilization of the acidic C-terminal and a relatively close interaction of the P-loop and the acidic C...... that changes the accessibility to the peptide/lectin-binding site. Our results indicate that the binding of Ca(2+) to calreticulin may thus not only just be a question of Ca(2+) storage but is likely to have an impact on the chaperone activity....

  6. Acute extracellular fluid volume changes increase ileocolonic resistance to saline flow in anesthetized dogs

    Directory of Open Access Journals (Sweden)

    Santiago Jr. A.T.

    1997-01-01

    Full Text Available We determined the effect of acute extracellular fluid volume changes on saline flow through 4 gut segments (ileocolonic, ileal, ileocolonic sphincter and proximal colon, perfused at constant pressure in anesthetized dogs. Two different experimental protocols were used: hypervolemia (iv saline infusion, 0.9% NaCl, 20 ml/min, volume up to 5% body weight and controlled hemorrhage (up to a 50% drop in mean arterial pressure. Mean ileocolonic flow (N = 6 was gradually and significantly decreased during the expansion (17.1%, P<0.05 and expanded (44.9%, P<0.05 periods while mean ileal flow (N = 7 was significantly decreased only during the expanded period (38%, P<0.05. Mean colonic flow (N = 7 was decreased during expansion (12%, P<0.05 but returned to control levels during the expanded period. Mean ileocolonic sphincter flow (N = 6 was not significantly modified. Mean ileocolonic flow (N = 10 was also decreased after hemorrhage (retracted period by 17% (P<0.05, but saline flow was not modified in the other separate circuits (N = 6, 5 and 4 for ileal, ileocolonic sphincter and colonic groups, respectively. The expansion effect was blocked by atropine (0.5 mg/kg, iv both on the ileocolonic (N = 6 and ileal (N = 5 circuits. Acute extracellular fluid volume retraction and expansion increased the lower gastrointestinal resistances to saline flow. These effects, which could physiologically decrease the liquid volume being supplied to the colon, are possible mechanisms activated to acutely balance liquid volume deficit and excess.

  7. No pituitary gland volume change in medication-free depressed patients.

    Science.gov (United States)

    Eker, Cagdas; Ovali, Gulgun Yilmaz; Ozan, Erol; Eker, Ozlem Donat; Kitis, Omer; Coburn, Kerry; Gonul, Ali Saffet

    2008-10-01

    Increased serum cortisol levels and a hyperactive hypothalamo-pituitary-adrenal (HPA) axis have been proposed to play an important role in the pathophysiology of Major Depressive Disorder (MDD). However, there are inconsistent results regarding pituitary gland volume (PGV), which is one of the key elements of the HPA axis evaluated by MRI in depressed patients. In this study, we analyzed the PGV of medication-free moderately depressed MDD patients (N=34) and age and sex matched healthy controls (N=39). PGV did not differ between MDD patients and healthy controls [mean volume+/-S.D.; 0.76+/-0.17 cm3 and 0.75+/-0.14 cm3; ANCOVA, F1,69=1.25 p>0.05; respectively]. Our results confirm that volumetric PGV changes are not crucial for depression pathophysiology among unmedicated, moderately depressed adults.

  8. The conditions and course of clinically induced phonological change.

    Science.gov (United States)

    Gierut, J A

    1992-10-01

    This two-part study continued the evaluation of minimal pair treatment in phonological change (Gierut, 1989, 1990, 1991a; Gierut & Neumann, 1992). Three linguistic variables relevant to change were experimentally manipulated within an alternating treatments design to determine specifically the interplay of a maximal number of feature distinctions, feature class, and relationship of treated phonemes to a child's grammar in inducing sound change. The conditions of treatment that were shown to facilitate optimal phonological change in previous research were again experimentally replicated. Specifically, minimal pairs comparing two phonemes previously unknown to a child that also differed by maximal and major class features were found to be the preferred context motivating change. Important individual differences emerged and underscored the role of a child's pretreatment grammar in phonological change. These differences contributed to descriptions of possible courses of change followed by children with phonological disorders and bear upon the predictability of change and the effectiveness of treatments that may condition change.

  9. Stress-induced changes in wheat grain composition and quality.

    Science.gov (United States)

    Ashraf, M

    2014-01-01

    Abiotic stresses such as drought, salinity, waterlogging, and high temperature cause a myriad of changes in the metabolism of plants, and there is a lot of overlap in these changes in plants in response to different stresses such as drought and salinity. These stress-induced metabolic changes cause impaired crop growth thereby resulting in poor yield. The metabolic changes taking place in several plant species due to a particular abiotic stress have been revealed from the whole plant to the molecular level by researchers, but most studies have focused on organs such as leaf, stem, and root. Information on such stress-induced changes in seed or grains is infrequent in the literature. From the information that is available, it is now evident that abiotic stress can induce considerable changes in the composition and quality of cereal grains including those of wheat, the premier staple food crop in the world. Thus, the present review discusses how far different types of stresses, mainly salinity, drought, high temperature, and waterlogging, can alter the wheat grain composition and quality. By fully uncovering the stress-induced changes in the nutritional values of wheat grains it would be possible to establish whether balanced supplies of essential nutrients are available to the human population from the wheat crop grown on stress-affected areas.

  10. 2,3-Dihydroxybenzoic acid attenuates kanamycin-induced volume reduction in mouse utricular type I hair cells

    DEFF Research Database (Denmark)

    Severinsen, Stig Åvall; Kirkegaard, Mette; Nyengaard, Jens Randel

    2006-01-01

    The aminoglycoside kanamycin is a commonly used antibiotic, but unfortunately it is oto- and nephrotoxic in large doses. The negative effects are thought to be due to the formation of free radicals which is why strong antioxidants and iron chelators like 2,3-dihydroxybenzoic acid (DHB) are of great...... interest. This study estimates cellular quantitative changes in the utricular macula of mice following systemic treatment with kanamycin alone or in combination with DHB. The animals were injected with either saline, kanamycin or kanamycin+DHB for 15 days and perfusion fixed three weeks after last...... macula, hair cell type I and supporting cells decreased significantly in animals injected with kanamycin but not in animals co-treated with DHB. Hair and supporting cell numbers remained unchanged in all three groups. In conclusion, the kanamycin-induced volume reduction of type I hair cells...

  11. Impact of blood volume changes within the human skin on the diffuse reflectance measurements in visible and NIR spectral ranges

    Science.gov (United States)

    Zherebtsov, Evgeny; Bykov, Alexander; Popov, Alexey; Doronin, Alexander; Meglinski, Igor

    2017-03-01

    We consider changes in the volume of blood and oxygen saturation caused by a pulse wave and their influence on the diffuse reflectance spectra in the visible/NIR spectral range. CUDA-based Monte-Carlo model was used for routine simulation of detector depth sensitivity (sampling volume) and skin spectra, and their variations associated with physiological changes in the human skin. The results presented in the form of animated graphs of sampling volume changes for scaling of the parameters of the main human skin layers related to the results of experimental measurements are of particular interest for pulse oximetry, photoplethysmography, Doppler flowmetry, reflectance spectroscopy.

  12. Combination of volume and perfusion parameters reveals different types of grey matter changes in schizophrenia.

    Science.gov (United States)

    Xu, Lixue; Qin, Wen; Zhuo, Chuanjun; Liu, Huaigui; Zhu, Jiajia; Yu, Chunshui

    2017-03-27

    Diverse brain structural and functional changes have been reported in schizophrenia. Identifying different types of brain changes may help to understand the neural mechanisms and to develop reliable biomarkers in schizophrenia. We aimed to categorize different grey matter changes in schizophrenia based on grey matter volume (GMV) and cerebral blood flow (CBF). Structural and perfusion magnetic resonance imaging data were acquired in 100 schizophrenia patients and 95 healthy comparison subjects. Voxel-based GMV comparison was used to show structural changes, CBF analysis was used to demonstrate functional changes. We identified three types of grey matter changes in schizophrenia: structural and functional impairments in the anterior cingulate cortex and insular cortex, displaying reduction in both GMV and CBF; structural impairment with preserved function in the frontal and temporal cortices, demonstrating decreased GMV with normal CBF; pure functional abnormality in the anterior cingulate cortex and lateral prefrontal cortex and putamen, showing altered CBF with normal GMV. By combination of GMV and CBF, we identified three types of grey matter changes in schizophrenia. These findings may help to understand the complex manifestations and to develop reliable biomarkers in schizophrenia.

  13. Changes in articular cartilage in experimentally induced patellar subluxation

    Science.gov (United States)

    Ryu, J.; Saito, S.; Yamamoto, K.

    1997-01-01

    OBJECTIVES—Patellar subluxation was experimentally induced in young rabbits and the resulting cartilaginous changes were observed over a prolonged period of time to determine histological changes in the subluxated patellar cartilage.
METHODS—The tibial tuberosity in 12 week old rabbits was laterally displaced and fixed to the tibia with wire to induce lateral patellar subluxation. Pathological changes in patellar cartilage were examined for 120 weeks after surgery using computed tomography and stereoscopic microscopy.
RESULTS—Eight weeks after surgery, changes in articular cartilage consisting of horizontal splitting of the matrix were observed in the intermediate zone and were presumed to have been caused by shearing stress applied to the patellar cartilage. The cartilaginous changes caused by patellar subluxation progressed very little over the 120 weeks. Very few rabbits presented with osteoarthritic changes in the patellofemoral joint, most probably because the stress resulting from the malalignment of the patellofemoral joint was mild enough to permit recovery.
CONCLUSION—The mild, non-progressive pathological changes, in particular, basal degeneration, induced in this experiment in patellar cartilage were quite similar to the changes in articular cartilage seen in human chondromalacia patellae.

 PMID:9462171

  14. Lithium-induced minimal change disease and acute kidney injury

    OpenAIRE

    Parul Tandon; Natalie Wong; Zaltzman, Jeffrey S.

    2015-01-01

    Context: Lithium carbonate is a psychiatric medication commonly used in the treatment of bipolar disorder. It has been implicated in inducing nephrogenic diabetes inspidus, chronic tubulointerstitial nephropathy, and acute tubular necrosis. We describe a case of lithium-induced minimal change disease (MCD) and acute kidney injury (AKI). Case Report: A 32-year-old female with a medical history of bipolar disorder treated with chronic lithium therapy presented with anasarca, fatigue, and tremor...

  15. Adolescent nicotine induces persisting changes in development of neural connectivity.

    Science.gov (United States)

    Smith, Robert F; McDonald, Craig G; Bergstrom, Hadley C; Ehlinger, Daniel G; Brielmaier, Jennifer M

    2015-08-01

    Adolescent nicotine induces persisting changes in development of neural connectivity. A large number of brain changes occur during adolescence as the CNS matures. These changes suggest that the adolescent brain may still be susceptible to developmental alterations by substances which impact its growth. Here we review recent studies on adolescent nicotine which show that the adolescent brain is differentially sensitive to nicotine-induced alterations in dendritic elaboration, in several brain areas associated with processing reinforcement and emotion, specifically including nucleus accumbens, medial prefrontal cortex, basolateral amygdala, bed nucleus of the stria terminalis, and dentate gyrus. Both sensitivity to nicotine, and specific areas responding to nicotine, differ between adolescent and adult rats, and dendritic changes in response to adolescent nicotine persist into adulthood. Areas sensitive to, and not sensitive to, structural remodeling induced by adolescent nicotine suggest that the remodeling generally corresponds to the extended amygdala. Evidence suggests that dendritic remodeling is accompanied by persisting changes in synaptic connectivity. Modeling, electrophysiological, neurochemical, and behavioral data are consistent with the implication of our anatomical studies showing that adolescent nicotine induces persisting changes in neural connectivity. Emerging data thus suggest that early adolescence is a period when nicotine consumption, presumably mediated by nicotine-elicited changes in patterns of synaptic activity, can sculpt late brain development, with consequent effects on synaptic interconnection patterns and behavior regulation. Adolescent nicotine may induce a more addiction-prone phenotype, and the structures altered by nicotine also subserve some emotional and cognitive functions, which may also be altered. We suggest that dendritic elaboration and associated changes are mediated by activity-dependent synaptogenesis, acting in part

  16. Influence of Environmental Factors on the Volume Change of Blended Cement Containing Steel Slag

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In the condition of 20 ℃, 5% sulfate liquor curing, standard tap water curing and 50% RH curing-three different curing environments, the volume change of steel slag blended cement influenced by environmental factors was studied. With steel slag addition 10%, 30%, 50%, from 90 days to 356 days, the relationship of shrinkage and three different curing environments is: dry curing environment>tap water curing environment>sulfate curing environment. But, the sample shrinkage in 28 days has much difference with the curing environment, which has no obvious orderliness. The different effects on blended cement containing steel slag in different environmental factors were analyzed using SEM.

  17. "Tilt" in color space: Hue changes induced by chromatic surrounds.

    Science.gov (United States)

    Klauke, Susanne; Wachtler, Thomas

    2015-01-01

    The perceived color of a chromatic stimulus is influenced by the chromaticity of its surround. To investigate these influences along the dimension of hue, we measured hue changes induced in stimuli of different hues by isoluminant chromatic surrounds. Generally, induced hue changes were directed in color space away from the hue of the inducing surround and depended on the magnitude on the hue difference between stimulus and surround. With increasing difference in hue between stimulus and surround, induced hue changes increased up to a maximum and then decreased for larger differences. This qualitative pattern was similar for different inducers, but quantitatively, induction was weaker along some directions in cone-opponent color space than along other directions. The strongest induction effects were found along an oblique, blue-yellow axis that corresponds to the daylight axis. The overall pattern of the induction effect shows similarities to the well-known tilt effect, where shifts in perceived angle of oriented stimuli are induced by oriented surrounds. This suggests analogous neural representations and similar mechanisms of contextual processing for different visual features such as orientation and color.

  18. Coupled wave analysis of holographically induced transparency (HIT) generated by two multiplexed volume gratings.

    Science.gov (United States)

    Carretero, Luis; Blaya, Salvador; Acebal, Pablo; Fimia, Antonio; Madrigal, Roque; Murciano, Angel

    2011-04-11

    We present a holographic system that can be used to manipulate the group velocity of light pulses. The proposed structure is based on the multiplexing of two sequential holographic volume gratings, one in transmission and the other in reflection geometry, where one of the recording beams must be the same for both structures. As in other systems such as grating induced transparency (GIT) or coupled-resonator-induced transparency (CRIT), by using the coupled wave theory it is shown that this holographic structure represents a classical analogue of the electromagnetically induced transparency (EIT). Analytical expressions were obtained for the transmittance induced at the forbidden band (spectral hole) and conditions where the group velocity was slowed down were analyzed. Moreover, the propagation of Gaussian pulses is analyzed for this system by obtaining, after further approximations, analytical expressions for the distortion of the transmitted field. As a result, we demonstrate the conditions where the transmitted pulse is slowed down and its shape is only slightly distorted. Finally, by comparing with the exact solutions obtained, the range of validity of all the analytical formulae was verified, demonstrating that the error is very low.

  19. Histopathological Sequential Changes in Sodium Taurocholate-Induced Acute Pancreatitis

    Directory of Open Access Journals (Sweden)

    Ashwinikumar Kudari

    2007-09-01

    Full Text Available Context Experimental models of acute pancreatitis have been developed in order to understand its pathophysiology and extrapancreatic manifestations. Objective The objective of our study was to study sequential changes in the pancreas and distant organs in sodium taurocholate-induced acute pancreatitis in a rat model. Animals Sixteen male Wistar rats weighing 250-300 g. Design The rats were distributed into two groups: induced acute pancreatitis (study group: 8 rats and a control group (8 rats. Within each group, the animals were divided into subgroups: those who were sacrificed early (24 h and 72 h; two each and those who were sacrificed late (120 h and 240 h; two each. Intervention Acute pancreatitis was induced in the rats by multiple intraparenchymal injections of 10% sodium taurocholate solution. In the controls, the same amount of normal saline was injected into the pancreatic parenchyma. Main outcome measures Pathological examination of the pancreas, lungs, kidneys, intestine and liver was done. Results In this model of taurocholate-induced acute pancreatitis, the early changes observed in the pancreas were focal hemorrhages, parenchymal necrosis and neutrophil infiltration. At 72 hours, the changes observed were acinar necrosis, edema, fibrin deposition and inflammatory cell infiltration. Late changes were fibrinoid necrosis and fibroblast proliferation. In the acute phase, the histological changes in the lungs were congestion, focal pulmonary edema and intraalveolar hemorrhages while, in the late stage, there was persistence of vascular congestion. The changes observed in the kidneys were vacuolization of tubular epithelium in the subcapsular region and areas of hemorrhage in the interstitium. Intestinal changes included degenerative changes in the villous epithelium in the acute phase with normalization of the histology in the late phase. Conclusion Our findings correlate with the clinical observation of multisystem organ failure in

  20. Pathways of deep cyclones associated with large volume changes (LVCs) and major Baltic inflows (MBIs)

    Science.gov (United States)

    Lehmann, Andreas; Höflich, Katharina; Post, Piia; Myrberg, Kai

    2017-03-01

    Large volume changes (LVCs) and major Baltic inflows (MBIs) are essential processes for the water exchange and renewal of the stagnant water in the Baltic Sea deep basins. These strong inflows are known to be forced by persistent westerly wind conditions. In this study, MBIs are considered as subset of LVCs transporting with the large water volume a big amount of highly saline and oxygenated water into the Baltic Sea. Since the early 1980s the frequency of MBIs has dropped drastically from 5 to 7 events to only one inflow per decade, and long lasting periods without MBIs became the usual state. Only in January 1993, 2003 and December 2014 MBIs occurred that were able to interrupt the stagnation periods in the deep basins of the Baltic Sea. However, in spite of the decreasing frequency of MBIs, there is no obvious decrease of LVCs. The Landsort sea level is known to reflect the mean sea level of the Baltic Sea very well, and hence LVCs have been calculated for the period 1887-2015 filtering daily time series of Landsort sea surface elevation anomalies. The cases with local minimum and maximum difference resulting in at least 60 km3 of water volume change excluding the volume change due to runoff have been chosen for a closer study (1948-2013) of characteristic pathways of deep cyclones. The average duration of LVCs is about 40 days. During this time, 5-6 deep cyclones move along characteristic storm tracks. Furthermore, MBIs are characterized by even higher cyclonic activity compared to average LVCs. We obtained four main routes of deep cyclones which were associated with LVCs, but also with the climatology. One is approaching from the west at about 56-60°N, passing the northern North Sea, northern Denmark, Sweden and the Island of Gotland. A second broad corridor of frequent cyclone pathways enters the study area north of Scotland between 60 and 66°N turning north-eastwards along the northern coast of Scandinavia. This branch bifurcates into smaller routes. One

  1. Accurate tracking of tumor volume change during radiotherapy by CT-CBCT registration with intensity correction

    Science.gov (United States)

    Park, Seyoun; Robinson, Adam; Quon, Harry; Kiess, Ana P.; Shen, Colette; Wong, John; Plishker, William; Shekhar, Raj; Lee, Junghoon

    2016-03-01

    In this paper, we propose a CT-CBCT registration method to accurately predict the tumor volume change based on daily cone-beam CTs (CBCTs) during radiotherapy. CBCT is commonly used to reduce patient setup error during radiotherapy, but its poor image quality impedes accurate monitoring of anatomical changes. Although physician's contours drawn on the planning CT can be automatically propagated to daily CBCTs by deformable image registration (DIR), artifacts in CBCT often cause undesirable errors. To improve the accuracy of the registration-based segmentation, we developed a DIR method that iteratively corrects CBCT intensities by local histogram matching. Three popular DIR algorithms (B-spline, demons, and optical flow) with the intensity correction were implemented on a graphics processing unit for efficient computation. We evaluated their performances on six head and neck (HN) cancer cases. For each case, four trained scientists manually contoured the nodal gross tumor volume (GTV) on the planning CT and every other fraction CBCTs to which the propagated GTV contours by DIR were compared. The performance was also compared with commercial image registration software based on conventional mutual information (MI), VelocityAI (Varian Medical Systems Inc.). The volume differences (mean±std in cc) between the average of the manual segmentations and automatic segmentations are 3.70+/-2.30 (B-spline), 1.25+/-1.78 (demons), 0.93+/-1.14 (optical flow), and 4.39+/-3.86 (VelocityAI). The proposed method significantly reduced the estimation error by 9% (B-spline), 38% (demons), and 51% (optical flow) over the results using VelocityAI. Although demonstrated only on HN nodal GTVs, the results imply that the proposed method can produce improved segmentation of other critical structures over conventional methods.

  2. Changes in gray matter volume after microsurgical lumbar discectomy: A longitudinal analysis

    Directory of Open Access Journals (Sweden)

    Michael eLuchtmann

    2015-02-01

    Full Text Available People around the world suffer chronic lower back pain. Because spine imaging often does not explain the degree of perceived pain reported by patients, the role of the processing of nociceptor signals in the brain as the basis of pain perception is gaining increased attention. Modern neuroimaging techniques (including functional and morphometric methods have produced results that suggest which brain areas may play a crucial role in the perception of acute and chronic pain. In this study, we examined twelve patients with chronic low back pain and sciatica, both resulting from lumbar disc herniation. Structural magnetic resonance imaging (MRI of the brain was performed one day prior to and about four weeks after microsurgical lumbar discectomy. The subsequent MRI revealed an increase in gray matter volume in the basal ganglia but a decrease in volume in the hippocampus, which suggests the complexity of the network that involves movement, pain processing, and aspects of memory. Interestingly, volume changes in the hippocampus were significantly correlated to preoperative pain intensity but not to the duration of chronic pain. Mapping structural changes of the brain that result from lumbar disc herniation has the potential to enhance our understanding of the neuropathology of chronic low back pain and sciatica and therefore may help to optimize the decisions we make about conservative and surgical treatments in the future. The possibility of illuminating more of the details of central pain processing in lumbar disc herniation, as well as the accompanying personal and economic impact of pain relief worldwide, calls for future large-scale clinical studies.

  3. Nasal Drug Absorption from Powder Formulations: Effect of Fluid Volume Changes on the Mucosal Surface.

    Science.gov (United States)

    Tanaka, Akiko; Furubayashi, Tomoyuki; Enomura, Yuki; Hori, Tomoki; Shimomura, Rina; Maeda, Chiaki; Kimura, Shunsuke; Inoue, Daisuke; Kusamori, Kosuke; Katsumi, Hidemasa; Sakane, Toshiyasu; Yamamoto, Akira

    2017-01-01

    The effect of changes in the mucosal fluid volume on the nasal drug absorption of powder formulations was evaluated using warfarin (WF), piroxicam (PXC), and norfloxacin (NFX) as model drugs. Lactose and sodium chloride (NaCl), which are water soluble and small-sized chemicals that increase osmotic pressure after dissolution, were used as excipients to change the mucosal fluid volume. The in vitro study using a Madin-Darby canine kidney (MDCK) cell monolayer indicated that lactose and NaCl, sprayed over the surface of air interface monolayers, increased the fluid volume on the monolayer surface and enhanced the transepithelial transport of the model drugs. The in vivo animal study indicated that the nasal absorption of PXC is enhanced by lactose and NaCl after nasal administration of the powder formulations. This is likely due to the enhanced dissolution of PXC on fluid-rich nasal mucosa and an increase in the effective surface area for drug permeation, which lead to better nasal absorption. However, both excipients failed to increase the nasal absorption of WF and NFX. To clarify the mechanism of the drug-dependent effect of lactose and NaCl, the nasal residence of the formulation was examined using FD70 as a non-absorbable marker. The nasal clearance of FD70 was enhanced by lactose and NaCl, leading to a decrease in the nasal drug absorption. Lactose and NaCl caused no damage to the nasal tissue. These results indicate that the addition of water-soluble excipients such as lactose to powder formulations can enhance the nasal absorption of highly permeable but poorly soluble drugs.

  4. Changes in perceived recovery status scale following high-volume muscle damaging resistance exercise.

    Science.gov (United States)

    Sikorski, Eric M; Wilson, Jacob M; Lowery, Ryan P; Joy, Jordan M; Laurent, C Matthew; Wilson, Stephanie M-C; Hesson, Domini; Naimo, Marshall A; Averbuch, Brian; Gilchrist, Phil

    2013-08-01

    Currently no research has investigated the relationship between muscle damage, hormonal status, and perceived recovery scale (PRS). Therefore, the purpose of this study was to determine the effects of a high-volume training session on PRS and to determine the relationship between levels of testosterone, cortisol, and creatine kinase (CK) and PRS. Thirty-five trained subjects (21.3 ± 1.9 years) were recruited. All subjects participated in a high-volume resistance training session consisting of 3 sets of full squats, bench press, deadlifts, pullups, dips, bent over rows, shoulder press, and barbell curls and extensions. Pre-PRS and post-PRS measurements (0-10), soreness, CK, cortisol, and testosterone were measured before and 48 hours after training. Perceived recovery scale declined from 8.6 ± 2.3 to 4.2 ± 1.85 (p Creatine kinase significantly increased from pre- to postworkout (189.4 ± 100.2 to 512 ± 222.7 U/L). Cortisol, testosterone, and free testosterone did not change. There was an inverse relationship between CK and PRS (r = 0.58, p resistance exercise lowers PRS scores. These changes are partly explained by a rise in serum indices of muscle damage. Moreover, free testosterone seems to have a positive relationship with PRS.

  5. Simulating Longitudinal Brain MRIs with Known Volume Changes and Realistic Variations in Image Intensity.

    Science.gov (United States)

    Khanal, Bishesh; Ayache, Nicholas; Pennec, Xavier

    2017-01-01

    This paper presents a simulator tool that can simulate large databases of visually realistic longitudinal MRIs with known volume changes. The simulator is based on a previously proposed biophysical model of brain deformation due to atrophy in AD. In this work, we propose a novel way of reproducing realistic intensity variation in longitudinal brain MRIs, which is inspired by an approach used for the generation of synthetic cardiac sequence images. This approach combines a deformation field obtained from the biophysical model with a deformation field obtained by a non-rigid registration of two images. The combined deformation field is then used to simulate a new image with specified atrophy from the first image, but with the intensity characteristics of the second image. This allows to generate the realistic variations present in real longitudinal time-series of images, such as the independence of noise between two acquisitions and the potential presence of variable acquisition artifacts. Various options available in the simulator software are briefly explained in this paper. In addition, the software is released as an open-source repository. The availability of the software allows researchers to produce tailored databases of images with ground truth volume changes; we believe this will help developing more robust brain morphometry tools. Additionally, we believe that the scientific community can also use the software to further experiment with the proposed model, and add more complex models of brain deformation and atrophy generation.

  6. Intermediate-depth earthquake faulting by dehydration embrittlement with negative volume change

    Science.gov (United States)

    Jung, Haemyeong; Green, Harry W., II; Dobrzhinetskaya, Larissa F.

    2004-04-01

    Earthquakes are observed to occur in subduction zones to depths of approximately 680km, even though unassisted brittle failure is inhibited at depths greater than about 50km, owing to the high pressures and temperatures. It is thought that such earthquakes (particularly those at intermediate depths of 50-300km) may instead be triggered by embrittlement accompanying dehydration of hydrous minerals, principally serpentine. A problem with failure by serpentine dehydration is that the volume change accompanying dehydration becomes negative at pressures of 2-4GPa (60-120km depth), above which brittle fracture mechanics predicts that the instability should be quenched. Here we show that dehydration of antigorite serpentinite under stress results in faults delineated by ultrafine-grained solid reaction products formed during dehydration. This phenomenon was observed under all conditions tested (pressures of 1-6GPa temperatures of 650-820°C), independent of the sign of the volume change of reaction. Although this result contradicts expectations from fracture mechanics, it can be explained by separation of fluid from solid residue before and during faulting, a hypothesis supported by our observations. These observations confirm that dehydration embrittlement is a viable mechanism for nucleating earthquakes independent of depth, as long as there are hydrous minerals breaking down under a differential stress.

  7. Midlife obesity and trajectories of brain volume changes in older adults.

    Science.gov (United States)

    Driscoll, Ira; Beydoun, May A; An, Yang; Davatzikos, Christos; Ferrucci, Luigi; Zonderman, Alan B; Resnick, Susan M

    2012-09-01

    Although obesity has been linked to structural brain changes, little is known about its associations with the rates of brain atrophy. We examined associations between global (BMI) and central (waist circumference) midlife obesity and subsequent trajectories of regional brain atrophy in 152 individuals [M (age) = 69 ± 7.8] prospectively followed through the Baltimore Longitudinal Study of Aging; 21 individuals became impaired during follow-up. We report no associations (P > 0.05) between either global or central midlife obesity and subsequent rates of regional brain volume changes against a background of age-related atrophy in older individuals who remained nondemented. When looking at the entire sample, greater decline was observed in the volume of gray matter, precuneus, cingulate and orbito-frontal gyri for globally obese (P obesity, a different pattern of results emerged. Overall, our results suggest that midlife obesity may be an important modifier of brain atrophy in individuals who are developing cognitive impairment and dementia, while it has little effect on structural brain integrity in nondemented older adults. Moreover, the discrepancies in findings between studies may be in part due to participant sampling and methodological differences. Published 2011 Wiley Periodicals, Inc.

  8. Changes in plasma volume during bed rest - Effects of menstrual cycle and estrogen administration

    Science.gov (United States)

    Fortney, S. M.; Beckett, W. S.; Carpenter, A. J.; Davis, J.; Drew, H.

    1988-01-01

    The effect of increased blood estrogen concentration, caused either during normal menstrual cycles or by exogenous administration of premarin, on the bed-rest (BR) induced decrease in plasma volume (PV) was investigated. In women who underwent duplicate 11-day BR without estrogen supplementation, the PV was found to decrease significantly, during the first 5 days of BR, to a lower level at which it remained for the rest of the BR period. In women who began BR in the periovulatory stage of the menstrual cycle, the loss of PV was delayed, while women who began BR during other stages of the cycle exhibited the usual trend of the PV decrease during the BR. In women who underwent a single 12-day BR period while taking premarin (1.25 mg/day), PV was found to decrease during the first 4-5 days of BR, but then returned toward the pre-BR level during the remainder of the BR, indicating that estrogens have a role in stabilizing body fluid volume.

  9. Clarithromycin-induced acute interstitial nephritis and minimal change disease

    OpenAIRE

    Russell, Wendy; Smith, William

    2009-01-01

    Drug associated acute interstitial nephritis and minimal change disease has been well documented but the simultaneous presentation of both is rare and has not been reported with clarithromycin. We describe a case of simultaneous acute tubulointerstitial nephritis and minimal change disease induced by clarithromycin. The patient had acute kidney injury, nephrotic syndrome, eosinophilic pneumonitis and a maculopapular skin rash. The role of steroid therapy in acute interstitial nephritis is con...

  10. Research on Greenhouse-Gas-Induced Climate Change

    Energy Technology Data Exchange (ETDEWEB)

    Schlesinger, M. E.

    2001-07-15

    During the 5 years of NSF grant ATM 95-22681 (Research on Greenhouse-Gas-Induced Climate Change, $1,605,000, 9/15/1995 to 8/31/2000) we have performed work which we are described in this report under three topics: (1) Development and Application of Atmosphere, Ocean, Photochemical-Transport, and Coupled Models; (2) Analysis Methods and Estimation; and (3) Climate-Change Scenarios, Impacts and Policy.

  11. The changes of holographic characteristics of photopolymer induced by temperature

    Institute of Scientific and Technical Information of China (English)

    Mingju Huang(黄明举); Huawen Yao(姚华文); Zhongyu Chen(陈仲裕); Lisong Hou(侯立松); Fuxi Gan(干福熹)

    2003-01-01

    The changes of holographic characteristics of photopolymer induced by temperature are studied experimentally. The results show that the exposure sensitivity increases with the increase of temperature. The maximum diffraction efficiency and the final maximum diffraction efficiency increase with the increase of temperature when the temperature is lower than Tg (glass transition temperature), while they decrease with the increase of temperature when the temperature is higher than Tg. The effect of the change of temperature on the saturation refractive index modulation is very weak.

  12. MR imaging findings of generalized tonic clonic seizure induced brain changes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jeong Ah; Chung, Jin Il; Yonn, Pyeong Ho; Kim, Dong Ik; Chung, Tae Sub; Kim, Joo Hee [College of Medicine, Yonsei Unversity, Seoul (Korea, Republic of)

    2000-03-01

    To evaluate MRI signal changes in the brain induced by generalized tonic clonic seizure. Six patients who underwent MRI within three days of generalized tonic clonic seizure were retrospectively reviewed. Diffusion -weighted images were added in three patients during initial examination, and in six, the follow-up MRI was performed nine days to five months after the onset of seizure. We evaluated the patterns of signal change, location of the lesion and degree of contrast enhancement, and the signal change seen on diffusion weighted images. We also compared the signal changes seen on initial and follow-up MRI. In all six patients, MR images showed focally increased T2 signal intensity, and swelling and increased volume of the involved cortical gyrus. In five, the lesion was mainly located in the cortical gray matter and subcortical white matter; namely, in the bilateral cingulate gyri, and the bilateral parieto-occipital, left parietal, left frontoparietal, and left temporal lobe. In the remaining patient, the lesion was located in the right hippocampus. Two patients showed bilateral lesions and one showed multiple lesions. In four patients, T1-weighted images revealed decreased signal intensity of the same location, and in one, gyral contrast enhancement was noted. On diffusion-weighted images, three patients showed increased signal intensity. Follow-up MRI demonstrated complete resolution of the abnormal signal change (n=3D5), or a decrease (n=3D1). A transient increase in MR signal intensity with increased volume was noted in cortical and subcortical white matter after generalized tonic clonic seizure. This finding reflects the vasogenic and cytotoxic edema induced by seizure and can help exclude etiologic lesions such as tumors, inflammation and demyelinating disease that induce epilepsy. (author)

  13. Three Decades of Volume Change of a Small Greenlandic Glacier Using Ground Penetrating Radar, Structure from Motion, and Aerial Photogrammetry

    DEFF Research Database (Denmark)

    Marcer, M.; Stentoft, Peter Alexander; Bjerre, Elisa

    2017-01-01

    Glaciers in the Arctic are losing mass at an increasing rate. Here we use surface topography derived from Structure from Motion (SfM) and ice volume from ground penetrating radar (GPR) to describe the 2014 state of Aqqutikitsoq glacier (2.85 km) on Greenland's west coast. A photogrammetrically...... topography, the approach constitutes a viable alternative where the use of drones is not possible. Our investigations constitute the first glacier on Greenland's west coast where ice volume was determined and volume change calculated. The glacier's thinning rate is comparable to, for example, the Swiss Alps...... and underlines that arctic glaciers are subject to fast changes....

  14. Daily Suction Provided by External Volume Expansion Inducing Regeneration of Grafted Fat in a Murine Model.

    Science.gov (United States)

    Ye, Yuan; Liao, Yunjun; Lu, Feng; Gao, Jianhua

    2017-02-01

    Fat grafting has variable and sometimes poor outcomes, and therefore new methods are needed. Multiple studies have demonstrated the excellent performance of external volume expansion and focused only on preexpansion with emphasis on the recipient. Two mouse models (a suction model and a fat-exchange transplantation model) were established to investigate changes in the origins and biological behaviors of regeneration-related cells in grafted fat under daily suction provided by external volume expansion. Blood supply increased from new host-derived capillaries or macrophage infiltration under suction. CD34-positive cells showed increased migration from the host into the grafts under suction. At week 12, nearly half of the mature adipocytes regenerated in the grafts in the suction group were derived from the host. Peroxisome proliferator-activated receptor γ expression of the suction group was significantly higher than that of controls at weeks 2 and 4 during adipogenesis. The normalized sample weight of the grafted fat was significantly greater than that of controls at 1 (0.081 ± 0.001 versus 0.072 ± 0.005; p suction provided by external volume expansion favors the regeneration of grafted fat and improves retention by promoting the migration of regeneration-related cells and the differentiation of adipocytes. Thus, more mature fat tissue with a well-organized structure was formed under suction.

  15. Chilling-Induced Changes in Aroma Volatile Profiles in Tomato

    NARCIS (Netherlands)

    Farneti, Brian; Alarcón, Alberto Algarra; Papasotiriou, F.G.; Samudrala, D.; Cristescu, S.M.; Costa, Guglielmo; Harren, F.J.M.; Woltering, E.J.

    2015-01-01

    Fruit and vegetables are regularly stored by consumers in the refrigerator at temperatures that may be well below the recommended storage temperatures. Apart from causing visible symptoms such as watery, sunken areas on the skin, chilling may also induce changes in fruit textural properties and

  16. Chilling-Induced Changes in Aroma Volatile Profiles in Tomato

    NARCIS (Netherlands)

    Farneti, Brian; Alarcón, Alberto Algarra; Papasotiriou, F.G.; Samudrala, D.; Cristescu, S.M.; Costa, Guglielmo; Harren, F.J.M.; Woltering, E.J.

    2015-01-01

    Fruit and vegetables are regularly stored by consumers in the refrigerator at temperatures that may be well below the recommended storage temperatures. Apart from causing visible symptoms such as watery, sunken areas on the skin, chilling may also induce changes in fruit textural properties and f

  17. Histochemical demonstration of mercury induced changes in rat neurons

    DEFF Research Database (Denmark)

    Danscher, G; Schrøder, H D

    1979-01-01

    A histochemical method modified for ultrastructural studies of mercury induced changes is described. Rat neurons from areas known to be influenced by mercury are used as examples. The histochemical reaction, suggested to be caused by polymercury sulphide complexes, is localized to "dense bodies...

  18. Temporal pore pressure induced stress changes during injection and depletion

    Science.gov (United States)

    Müller, Birgit; Heidbach, Oliver; Schilling, Frank; Fuchs, Karl; Röckel, Thomas

    2016-04-01

    Induced seismicity is observed during injection of fluids in oil, gas or geothermal wells as a rather immediate response close to the injection wells due to the often high-rate pressurization. It was recognized even earlier in connection with more moderate rate injection of fluid waste on a longer time frame but higher induced event magnitudes. Today, injection-related induced seismicity significantly increased the number of events with M>3 in the Mid U.S. However, induced seismicity is also observed during production of fluids and gas, even years after the onset of production. E.g. in the Groningen gas field production was required to be reduced due to the increase in felt and damaging seismicity after more than 50 years of exploitation of that field. Thus, injection and production induced seismicity can cause severe impact in terms of hazard but also on economic measures. In order to understand the different onset times of induced seismicity we built a generic model to quantify the role of poro-elasticity processes with special emphasis on the factors time, regional crustal stress conditions and fault parameters for three case studies (injection into a low permeable crystalline rock, hydrothermal circulation and production of fluids). With this approach we consider the spatial and temporal variation of reservoir stress paths, the "early" injection-related induced events during stimulation and the "late" production induced ones. Furthermore, in dependence of the undisturbed in situ stress field conditions the stress tensor can change significantly due to injection and long-term production with changes of the tectonic stress regime in which previously not critically stressed faults could turn to be optimally oriented for fault reactivation.

  19. Clarithromycin-induced acute interstitial nephritis and minimal change disease.

    Science.gov (United States)

    Russell, Wendy; Smith, William

    2009-10-01

    Drug associated acute interstitial nephritis and minimal change disease has been well documented but the simultaneous presentation of both is rare and has not been reported with clarithromycin. We describe a case of simultaneous acute tubulointerstitial nephritis and minimal change disease induced by clarithromycin. The patient had acute kidney injury, nephrotic syndrome, eosinophilic pneumonitis and a maculopapular skin rash. The role of steroid therapy in acute interstitial nephritis is controversial but is accepted as beneficial in minimal change nephrotic syndrome. Steroid therapy in our patient resulted in complete clinical resolution.

  20. Inconsistent detection of changes in cerebral blood volume by near infrared spectroscopy in standard clinical tests.

    Science.gov (United States)

    Canova, D; Roatta, S; Bosone, D; Micieli, G

    2011-06-01

    The attractive possibility of near infrared spectroscopy (NIRS) to noninvasively assess cerebral blood volume and oxygenation is challenged by the possible interference from extracranial tissues. However, to what extent this may affect cerebral NIRS monitoring during standard clinical tests is ignored. To address this issue, 29 healthy subjects underwent a randomized sequence of three maneuvers that differently affect intra- and extracranial circulation: Valsalva maneuver (VM), hyperventilation (HV), and head-up tilt (HUT). Putative intracranial ("i") and extracranial ("e") NIRS signals were collected from the forehead and from the cheek, respectively, and acquired together with cutaneous plethysmography at the forehead (PPG), cerebral blood velocity from the middle cerebral artery, and arterial blood pressure. Extracranial contribution to cerebral NIRS monitoring was investigated by comparing Beer-Lambert (BL) and spatially resolved spectroscopy (SRS) blood volume indicators [the total hemoglobin concentration (tHb) and the total hemoglobin index, (THI)] and by correlating their changes with changes in extracranial circulation. While THIe and tHbe generally provided concordant indications, tHbi and THIi exhibited opposite-sign changes in a high percentage of cases (VM: 46%; HV: 31%; HUT: 40%). Moreover, tHbi was correlated with THIi only during HV (P < 0.05), not during VM and HUT, while it correlated with PPG in all three maneuvers (P < 0.01). These results evidence that extracranial circulation may markedly affect BL parameters in a high percentage of cases, even during standard clinical tests. Surface plethysmography at the forehead is suggested as complementary monitoring helpful in the interpretation of cerebral NIRS parameters.

  1. Volume changes of extremely large and giant intracranial aneurysms after treatment with flow diverter stents

    Energy Technology Data Exchange (ETDEWEB)

    Carneiro, Angelo; Byrne, James V. [ohn Radcliffe Hospital, Oxford Neurovascular and Neuroradiology Research Unit, Nuffield Department of Surgical Sciences, Oxford (United Kingdom); Rane, Neil; Kueker, Wilhelm; Cellerini, Martino; Corkill, Rufus [John Radcliffe Hospital, Department of Neuroradiology, Oxford (United Kingdom)

    2014-01-15

    This study assessed volume changes of unruptured large and giant aneurysms (greatest diameter >20 mm) after treatment with flow diverter (FD) stents. Clinical audit of the cases treated in a single institution, over a 5-year period. Demographic and clinical data were retrospectively collected from the hospital records. Aneurysm volumes were measured by manual outlining at sequential slices using computerised tomography (CT) or magnetic resonance (MR) angiography data. The audit included eight patients (seven females) with eight aneurysms. Four aneurysms involved the cavernous segment of the internal carotid artery (ICA), three the supraclinoid ICA and one the basilar artery. Seven patients presented with signs and symptoms of mass effect and one with seizures. All but one aneurysm was treated with a single FD stent; six aneurysms were also coiled (either before or simultaneously with FD placement). Minimum follow-up time was 6 months (mean 20 months). At follow-up, three aneurysms decreased in size, three were unchanged and two increased. Both aneurysms that increased in size showed persistent endosaccular flow at follow-up MR; in one case, failure was attributed to suboptimal position of the stent; in the other case, it was attributed to persistence of a side branch originating from the aneurysm (similar to the endoleak phenomenon of aortic aneurysms). At follow-up, five aneurysms were completely occluded; none of these increased in volume. Complete occlusion of the aneurysms leads, in most cases, to its shrinkage. In cases of late aneurysm growth or regrowth, consideration should be given to possible endoleak as the cause. (orig.)

  2. Study of laser induced thermo-acoustic signals in a large ice volume

    Energy Technology Data Exchange (ETDEWEB)

    Bissok, Martin; Laihem, Karim; Meures, Thomas; Paul, Larissa; Wiebusch, Christopher; Zierke, Simon [III. Physikalisches Institut, RWTH Aachen (Germany)

    2010-07-01

    A goal for next generation neutrino-telescopes is the exploration of the extremely high energy region (>EeV). Expected neutrino event rates in this energy range are low (<1 event/km{sup 3}/year) and therefore a detector volume which is increased by more than one order of magnitude compared to IceCube is desireable. A possible approach to achieve such an increase in a cost-effective way is the acoustic detection of neutrinos, based on the principle of thermoacoustic signal generation in neutrino-induced hadronic cascades. The Aachen Acoustic Laboratory (AAL) provides the means to study the thermoacoustic effect in a controlled environment. It consists of a large water-filled tank inside a cooling container. The freezing process is controlled and a large volume of bubble-free clear ice({proportional_to}3m{sup 3}) is produced. Thermoacoustic signals are generated by a pulsed Nd:YAG laser with an energy of up to 55 mJ/pulse. The acoustic signals are recorded by an array of 19 piezo-based sensors embedded in the ice. In this talk we give a description of this test experiment and present results from an initial freezing period.

  3. Measurements of Photo-induced Changes in Conjugated Polymers

    Science.gov (United States)

    Seager, C. H.; Sinclair, M. B.; Mc Branch, D.; Heeger, A. J.; Baker, G. L.

    1991-01-01

    We have used the highly sensitive technique of Photothermal Deflection Spectroscopy (PDS) to measure changes in the infrared absorption spectra of MEHPPV, P3HT and Polydiacetylene-4BCMU induced by pumping these polymers with light above the {pi} - {pi}* transition energy. In contrast to previous chopped light transmission measurements of these effects, the PDS technique can directly measure the buildup or decay of the absorption coefficient, {alpha}, on the time scale of second to days. In the case of MEHPPV we observe that the time scale of seconds to days. In the case of MEHPPV we observe that above-gap light causes the appearance of a broad infrared peak in {alpha}, which continues to grow-in hours after the pump light is first applied. For this polymer the general shape of the absorption spectra in the unpumped state mimics the photo-induced changes, suggesting that remnant photo-induced states determine the maximum transparency observed under normal experimental conditions. For P3HT and to a lesser extent, MEHPPV, we also observe irreversible photo-induced absorption components which we tentatively identify with photo-induced oxidation of the polymer matrix.

  4. Estimation of volume and mass and of changes in volume and mass of selected chat piles in the Picher mining district, Ottawa County, Oklahoma, 2005-10

    Science.gov (United States)

    Smith, S. Jerrod

    2013-01-01

    From the 1890s through the 1970s the Picher mining district in northeastern Ottawa County, Oklahoma, was the site of mining and processing of lead and zinc ore. When mining ceased in about 1979, as much as 165–300 million tons of mine tailings, locally referred to as “chat,” remained in the Picher mining district. Since 1979, some chat piles have been mined for aggregate materials and have decreased in volume and mass. Currently (2013), the land surface in the Picher mining district is covered by thousands of acres of chat, much of which remains on Indian trust land owned by allottees. The Bureau of Indian Affairs manages these allotted lands and oversees the sale and removal of chat from these properties. To help the Bureau of Indian Affairs better manage the sale and removal of chat, the U.S. Geological Survey, in cooperation with the Bureau of Indian Affairs, estimated the 2005 and 2010 volumes and masses of selected chat piles remaining on allotted lands in the Picher mining district. The U.S. Geological Survey also estimated the changes in volume and mass of these chat piles for the period 2005 through 2010. The 2005 and 2010 chat-pile volume and mass estimates were computed for 34 selected chat piles on 16 properties in the study area. All computations of volume and mass were performed on individual chat piles and on groups of chat piles in the same property. The Sooner property had the greatest estimated volume (4.644 million cubic yards) and mass (5.253 ± 0.473 million tons) of chat in 2010. Five of the selected properties (Sooner, Western, Lawyers, Skelton, and St. Joe) contained estimated chat volumes exceeding 1 million cubic yards and estimated chat masses exceeding 1 million tons in 2010. Four of the selected properties (Lucky Bill Humbah, Ta Mee Heh, Bird Dog, and St. Louis No. 6) contained estimated chat volumes of less than 0.1 million cubic yards and estimated chat masses of less than 0.1 million tons in 2010. The total volume of all

  5. Hepatic changes during a carrageenan induced granuloma in rats

    Directory of Open Access Journals (Sweden)

    J. Muntané

    1993-01-01

    Full Text Available Hepatic changes during inflammation were studied in rats bearing a carrageenan induced granuloma. In spite of a decrease in the metabolic capacity of microsomes to induce lipid peroxidation during inflammation, the endogenous lipid peroxidation remained unchanged and unrelated with the hepatic activities measured. The continuous increase in hepatic cAMP observed during acute and chronic phases could be related to adenylate cyclase stimulation by mediators, and could be an initial step in the hepatocyte adaptation leading to the increased level of hepatic caeruloplasmin, to the reduction of cytochrome P-450 level and to the modifications of Ca2+ sequestration by microsomes.

  6. Are forest disturbances amplifying or canceling out climate change-induced productivity changes in European forests?

    Science.gov (United States)

    Reyer, Christopher P O; Bathgate, Stephen; Blennow, Kristina; Borges, Jose G; Bugmann, Harald; Delzon, Sylvain; Faias, Sonia P; Garcia-Gonzalo, Jordi; Gardiner, Barry; Gonzalez-Olabarria, Jose Ramon; Gracia, Carlos; Hernández, Juan Guerra; Kellomäki, Seppo; Kramer, Koen; Lexer, Manfred J; Lindner, Marcus; van der Maaten, Ernst; Maroschek, Michael; Muys, Bart; Nicoll, Bruce; Palahi, Marc; Palma, João HN; Paulo, Joana A; Peltola, Heli; Pukkala, Timo; Rammer, Werner; Ray, Duncan; Sabaté, Santiago; Schelhaas, Mart-Jan; Seidl, Rupert; Temperli, Christian; Tomé, Margarida; Yousefpour, Rasoul; Zimmermann, Niklaus E; Hanewinkel, Marc

    2017-01-01

    Recent studies projecting future climate change impacts on forests mainly consider either the effects of climate change on productivity or on disturbances. However, productivity and disturbances are intrinsically linked because 1) disturbances directly affect forest productivity (e.g. via a reduction in leaf area, growing stock or resource-use efficiency), and 2) disturbance susceptibility is often coupled to a certain development phase of the forest with productivity determining the time a forest is in this specific phase of susceptibility. The objective of this paper is to provide an overview of forest productivity changes in different forest regions in Europe under climate change, and partition these changes into effects induced by climate change alone and by climate change and disturbances. We present projections of climate change impacts on forest productivity from state-of-the-art forest models that dynamically simulate forest productivity and the effects of the main European disturbance agents (fire, storm, insects), driven by the same climate scenario in seven forest case studies along a large climatic gradient throughout Europe. Our study shows that, in most cases, including disturbances in the simulations exaggerate ongoing productivity declines or cancel out productivity gains in response to climate change. In fewer cases, disturbances also increase productivity or buffer climate-change induced productivity losses, e.g. because low severity fires can alleviate resource competition and increase fertilization. Even though our results cannot simply be extrapolated to other types of forests and disturbances, we argue that it is necessary to interpret climate change-induced productivity and disturbance changes jointly to capture the full range of climate change impacts on forests and to plan adaptation measures. PMID:28855959

  7. Are forest disturbances amplifying or canceling out climate change-induced productivity changes in European forests?

    Science.gov (United States)

    Reyer, Christopher P. O.; Bathgate, Stephen; Blennow, Kristina; Borges, Jose G.; Bugmann, Harald; Delzon, Sylvain; Faias, Sonia P.; Garcia-Gonzalo, Jordi; Gardiner, Barry; Gonzalez-Olabarria, Jose Ramon; Gracia, Carlos; Guerra Hernández, Juan; Kellomäki, Seppo; Kramer, Koen; Lexer, Manfred J.; Lindner, Marcus; van der Maaten, Ernst; Maroschek, Michael; Muys, Bart; Nicoll, Bruce; Palahi, Marc; Palma, João HN; Paulo, Joana A.; Peltola, Heli; Pukkala, Timo; Rammer, Werner; Ray, Duncan; Sabaté, Santiago; Schelhaas, Mart-Jan; Seidl, Rupert; Temperli, Christian; Tomé, Margarida; Yousefpour, Rasoul; Zimmermann, Niklaus E.; Hanewinkel, Marc

    2017-03-01

    Recent studies projecting future climate change impacts on forests mainly consider either the effects of climate change on productivity or on disturbances. However, productivity and disturbances are intrinsically linked because 1) disturbances directly affect forest productivity (e.g. via a reduction in leaf area, growing stock or resource-use efficiency), and 2) disturbance susceptibility is often coupled to a certain development phase of the forest with productivity determining the time a forest is in this specific phase of susceptibility. The objective of this paper is to provide an overview of forest productivity changes in different forest regions in Europe under climate change, and partition these changes into effects induced by climate change alone and by climate change and disturbances. We present projections of climate change impacts on forest productivity from state-of-the-art forest models that dynamically simulate forest productivity and the effects of the main European disturbance agents (fire, storm, insects), driven by the same climate scenario in seven forest case studies along a large climatic gradient throughout Europe. Our study shows that, in most cases, including disturbances in the simulations exaggerate ongoing productivity declines or cancel out productivity gains in response to climate change. In fewer cases, disturbances also increase productivity or buffer climate-change induced productivity losses, e.g. because low severity fires can alleviate resource competition and increase fertilization. Even though our results cannot simply be extrapolated to other types of forests and disturbances, we argue that it is necessary to interpret climate change-induced productivity and disturbance changes jointly to capture the full range of climate change impacts on forests and to plan adaptation measures.

  8. Are forest disturbances amplifying or canceling out climate change-induced productivity changes in European forests?

    Science.gov (United States)

    Reyer, Christopher P O; Bathgate, Stephen; Blennow, Kristina; Borges, Jose G; Bugmann, Harald; Delzon, Sylvain; Faias, Sonia P; Garcia-Gonzalo, Jordi; Gardiner, Barry; Gonzalez-Olabarria, Jose Ramon; Gracia, Carlos; Hernández, Juan Guerra; Kellomäki, Seppo; Kramer, Koen; Lexer, Manfred J; Lindner, Marcus; van der Maaten, Ernst; Maroschek, Michael; Muys, Bart; Nicoll, Bruce; Palahi, Marc; Palma, João Hn; Paulo, Joana A; Peltola, Heli; Pukkala, Timo; Rammer, Werner; Ray, Duncan; Sabaté, Santiago; Schelhaas, Mart-Jan; Seidl, Rupert; Temperli, Christian; Tomé, Margarida; Yousefpour, Rasoul; Zimmermann, Niklaus E; Hanewinkel, Marc

    2017-03-16

    Recent studies projecting future climate change impacts on forests mainly consider either the effects of climate change on productivity or on disturbances. However, productivity and disturbances are intrinsically linked because 1) disturbances directly affect forest productivity (e.g. via a reduction in leaf area, growing stock or resource-use efficiency), and 2) disturbance susceptibility is often coupled to a certain development phase of the forest with productivity determining the time a forest is in this specific phase of susceptibility. The objective of this paper is to provide an overview of forest productivity changes in different forest regions in Europe under climate change, and partition these changes into effects induced by climate change alone and by climate change and disturbances. We present projections of climate change impacts on forest productivity from state-of-the-art forest models that dynamically simulate forest productivity and the effects of the main European disturbance agents (fire, storm, insects), driven by the same climate scenario in seven forest case studies along a large climatic gradient throughout Europe. Our study shows that, in most cases, including disturbances in the simulations exaggerate ongoing productivity declines or cancel out productivity gains in response to climate change. In fewer cases, disturbances also increase productivity or buffer climate-change induced productivity losses, e.g. because low severity fires can alleviate resource competition and increase fertilization. Even though our results cannot simply be extrapolated to other types of forests and disturbances, we argue that it is necessary to interpret climate change-induced productivity and disturbance changes jointly to capture the full range of climate change impacts on forests and to plan adaptation measures.

  9. Self-heating probe instrument and method for measuring high temperature melting volume change rate of material

    Science.gov (United States)

    Wang, Junwei; Wang, Zhiping; Lu, Yang; Cheng, Bo

    2013-03-01

    The castings defects are affected by the melting volume change rate of material. The change rate has an important effect on running safety of the high temperature thermal storage chamber, too. But the characteristics of existing measuring installations are complex structure, troublesome operation and low precision. In order to measure the melting volume change rate of material accurately and conveniently, a self-designed measuring instrument, self-heating probe instrument, and measuring method are described. Temperature in heating cavity is controlled by PID temperature controller; melting volume change rate υ and molten density are calculated based on the melt volume which is measured by the instrument. Positive and negative υ represent expansion and shrinkage of the sample volume after melting, respectively. Taking eutectic LiF+CaF2 for example, its melting volume change rate and melting density at 1 123 K are -20.6% and 2 651 kg·m-3 measured by this instrument, which is only 0.71% smaller than literature value. Density and melting volume change rate of industry pure aluminum at 973 K and analysis pure NaCl at 1 123 K are detected by the instrument too. The measure results are agreed with report values. Measuring error sources are analyzed and several improving measures are proposed. In theory, the measuring errors of the change rate and molten density which are measured by the self-designed instrument is nearly 1/20-1/50 of that measured by the refitted mandril thermal expansion instrument. The self-designed instrument and method have the advantages of simple structure, being easy to operate, extensive applicability for material, relatively high accuracy, and most importantly, temperature and sample vapor pressure have little effect on the measurement accuracy. The presented instrument and method solve the problems of complicated structure and procedures, and large measuring errors for the samples with high vapor pressure by existing installations.

  10. Changes in blood volume and response to vaso-active drugs in horizontally casted primates

    Science.gov (United States)

    Dickey, D. T.; Teoh, K. K.; Sandler, H.; Stone, H. L.

    1982-01-01

    Experiments were performed on horizontally casted primates (male rhesus monkeys) in order to note changes in blood volume caused by horizontal restraint, to compare orthostatic tolerance before and after casting using the responses to upright tilting, to begin to uncover the cardiovascular and neural mechanisms involved in deconditioning, and to compare the data with that obtained from bed-rested human subjects and from humans exposed to weightlessness. Bolus injections of norepinephrine of 2.0 microgram/kg, phenylephrine of 4.0 microgram/kg, and nitroprusside of 2.0 microgram/kg were administered; and aortic pressure and heart rate were recorded during the injections. The results indicate that the horizontally casted primate is a valid animal model for studying the effects of simulated zero-G on the human cardiovascular system.

  11. Pressure-induced volume expansion of zeolites in the natrolite family.

    Science.gov (United States)

    Lee, Yongjae; Vogt, Thomas; Hriljac, Joseph A; Parise, John B; Artioli, Gilberto

    2002-05-15

    Powder diffraction patterns of the zeolites natrolite (Na(16)Al(16)Si(24)O(80).16H(2)O), mesolite (Na(5.33)Ca(5.33)Al(16)Si(24)O(80).21.33H(2)O), scolecite (Ca(8)Al(16)Si(24)O(80).24H(2)O), and a gallosilicate analogue of natrolite (K(16)Ga(16)Si(24)O(80).12H(2)O), all crystallizing with a natrolite framework topology, were measured as a function of pressure up to 5.0 GPa with use of a diamond-anvil cell and a 200 microm focused monochromatic synchrotron X-ray beam. Under the hydrostatic conditions mediated by an alcohol and water mixture, all these materials showed an abrupt volume expansion (ca. 2.5% in natrolite) between 0.8 and 1.5 GPa without altering the framework topology. Rietveld refinements using the data collected on natrolite show that the anomalous swelling is due to the selective sorption of water from the pressure-transmission fluid expanding the channels along the a- and b-unit cell axes. This gives rise to a "superhydrated" phase of natrolite with an approximate formula of Na(16)Al(16)Si(24)O(80).32H(2)O, which contains hydrogen-bonded helical water nanotubes along the channels. In mesolite, which at ambient pressure is composed of ordered layers of sodium- and calcium-containing channels in a 1:2 ratio along the b-axis, this anomalous swelling is accompanied by a loss of the superlattice reflections (b(mesolite) = 3b(natrolite)). This suggests a pressure-induced order-disorder transition involving the motions of sodium and calcium cations either through cross-channel diffusion or within the respective channels. The powder diffraction data of scolecite, a monoclinic analogue of natrolite where all sodium cations are substituted by calcium and water molecules, reveal a reversible pressure-induced partial amorphization under hydrostatic conditions. Unlike the 2-dimensional swelling observed in natrolite and mesolite, the volume expansion of the potassium gallosilicate natrolite is 3-dimensional and includes the lengthening of the channel axis. In

  12. Influence of lung volume, fluid and capillary recruitment during positional changes and exercise on thoracic impedance in heart failure.

    Science.gov (United States)

    Kim, Chul-Ho; Fuglestad, Matthew A; Richert, Maile L Ceridon; Shen, Win K; Johnson, Bruce D

    2014-10-01

    It is unclear how dynamic changes in pulmonary-capillary blood volume (Vc), alveolar lung volume (derived from end-inspiratory lung volume, EILV) and interstitial fluid (ratio of alveolar capillary membrane conductance and pulmonary capillary blood volume, Dm/Vc) influence lung impedance (Z(T)). The purpose of this study was to investigate if positional change and exercise result in increased EILV, Vc and/or lung interstitial fluid, and if Z(T) tracks these variables. 12 heart failure (HF) patients underwent measurements (Z(T), EILV, Vc/Dm) at rest in the upright and supine positions, during exercise and into recovery. Inspiratory capacity was obtained to provide consistent measures of EILV while assessing Z(T). Z(T) increased with lung volume during slow vital capacity maneuvers (p0.05). Impedance appears sensitive to changes in lung volume and body position which appear to generally overwhelm small acute changes in lung fluid when assed dynamically at rest or during exercise. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Atomistic simulation study of the effect of martensitic transformation volume change on crack-tip material evolution and fracture toughness

    Energy Technology Data Exchange (ETDEWEB)

    Grujicic, M. [Clemson Univ., SC (United States). Dept. of Mechanical Engineering; Lai, S.G. [Clemson Univ., SC (United States). Dept. of Mechanical Engineering; Gumbsch, P. [Max Planck-Institut fur Metallforshung Institut fuer Werstoffwissenshaft, Seestrasse 92, D-7000 Stuttgart I (Germany)

    1997-07-15

    The effect of the sign of the F.C.C.{yields}B.C.C. martensitic transformation volume change in Fe-20Ni on material evolution in a region surrounding the crack tip and the accompanying change in the fracture resistance of the material have been investigated using molecular dynamics simulations. The interaction between atoms has been modeled using the embedded atom method (EAM) interatomic potentials. To obtain both the positive and the negative values of the transformation volume change, small adjustments had to be made in the EAM functions. These changes did not significantly affect of the key materials properties, such as the relative thermodynamic stability of the F.C.C. and B.C.C. structures, elastic constants, (11 anti 2){sub bcc} twin boundary energy, (10 anti 1){sub fcc}/(1 anti 21){sub bcc} interfacial energy, etc. The simulation results show that the sign of the transformation volume change has a profound effect on the material evolution and the path of the advancing crack. When the volume change is negative, the region ahead of the crack tip undergoes the transformation only after the other regions around the crack tip have already transformed. The crack tip undergoes a significant blunting and tends to stay on the original crack plane. In sharp contrast, when the volume change is positive, the region ahead of the crack tip transforms first and significant decohesion along the F.C.C./B.C.C. interfaces takes place. Consequently the crack tends to branch out. The effect of material evolution at the crack tip on the ability of the material to withstand further fracture has been quantified by calculating the Eshelby`s F{sub 1} conservation integral. The sign of the transformation volume change is found to have a major effect on the change of the F{sub 1} integral with the simulation time. (orig.)

  14. Negative Associations between Perceived Training Load, Volume and Changes in Physical Fitness in Professional Soccer Players

    Directory of Open Access Journals (Sweden)

    Asier Los Arcos, Raul Martínez-Santos, Javier Yanci, Jurdan Mendiguchia, Alberto Méndez-Villanueva

    2015-06-01

    Full Text Available The purpose of this study was to examine the usefulness of the rating of perceived exertion training load for monitoring changes in several aerobic fitness and neuromuscular performance variables during 9 weeks of soccer training in young professional players. Nineteen male soccer players (20.2 ± 1.9 years belonging to the same reserve team of a Spanish La Liga Club participated in this study. Countermovement jump (CMJ, CMJ arm swing, single leg CMJ, a sprint running test (i.e., 5 m and 15 m times and an aerobic fitness running test were performed at the start of the pre-season (Test 1 and 9 weeks later (Test 2. During 9 weeks, after each training session and match, players reported their rating of perceived exertion (RPE separately for respiratory (RPEres and leg musculature (RPEmus effort. The training load (TL was calculated by multiplying the RPE value by the duration in minutes of each training session or match. Accumulated RPEmus, and associated TL, as well as accumulated training volume were negatively correlated with the changes in most physical fitness attributes after 9 weeks of training (r = -0.51 to -0.64. Present results suggest that a high perception of leg muscular effort associated with training sessions and matches, as well as an excessive accumulation of training volume (time, can impair the improvement in several physical fitness variables believed to be relevant for on-field soccer performance. Therefore, the independent assessment of leg muscular effort to quantify TL can be an interesting additional monitoring measure in soccer training.

  15. Volume Change Measurement Of Collapsible Soil Stabilized With Lime And Waste Lime

    Directory of Open Access Journals (Sweden)

    Khawla A. Al-Juari

    2013-05-01

    Full Text Available This paper presents a series of laboratory tests to evaluate the effects of lime and waste lime on the volume change and strength characteristics of moderately collapsible soil selected from Al-Rashidia in Mosul city. The tests are performed at different percentages of lime and waste lime of 0, 0.25, 0.5, 1.0, 2.0, 3.0, 4.0, 6.0 and 8.0% by dry weight of soil. One dimensional compression tests are conducted to clarify the influences of relative compaction, compaction water content, vertical stress level and curing time on the volume change and strength characteristics.The results of this study indicated a decrease in the plasticity, swelling potential and swelling pressure of treated soil. The soil became non-plastic at (3&6% of lime and waste lime respectively. Swelling pressure and swelling potential reached to zero at 2% lime and  2&7 days of curing time.Unconfined compressive strength (UCS reached to maximum value at optimum stabilizers content. The UCS of lime treated soil is more than that treated by waste lime at different curing time. The collapse index and potential of treated soil are found less than that of natural soil and decrease with increasing stabilizer content until drop to zero at 2% lime. Collapsing increased continuously with applied stresses, but with curing time reached a maximum value at 2 day. On the other hand, collapsing of treated soil with lime is less than that  of waste lime treated soil at different curing time and stresses.

  16. Changes in lakes water volume and runoff over ungauged Sahelian watersheds

    Science.gov (United States)

    Gal, L.; Grippa, M.; Hiernaux, P.; Peugeot, C.; Mougin, E.; Kergoat, L.

    2016-09-01

    A large part of the Sahel consists of endorheic hydrological systems, where reservoirs and lakes capture surface runoff during the rainy season, making water available during the dry season. Monitoring and understanding the dynamics of these lakes and their relationships to the ecohydrological evolution of the region is important to assess past, present and future changes of water resources in the Sahel. Yet, most of Sahelian watersheds are still ungauged or poorly gauged, which hinders the assessment of the water flows feeding the lakes and the overall runoff over their watershed. In this paper, a methodology is developed to estimate water inflow to lakes for ungauged watersheds. It is tested for the Agoufou lake in the Gourma region in Mali, for which in situ water height measurements and surface areas estimations by remote sensing are simultaneously available. A Height-Volume-Area (HVA) model is developed to relate water volume to water height and lake surface area. This model is combined to daily evaporation and precipitation to estimate water inflow to the lake, which approximates runoff over the whole watershed. The ratio between annual water inflow and precipitation increases over the last sixty years as a result of a significant increase in runoff coefficient over the Agoufou watershed. The method is then extended to derive water inflow to three other Sahelian lakes in Mauritania and Niger. No in situ measurements are available and lake surface areas estimation by remote sensing is the only source of information. Dry season surface area changes and estimated evaporation are used to select a suited VA relationship for each case. It is found that the ratio between annual water inflow and precipitation has also increased in the last 60 years over these watersheds, although trends at the Mauritanian site are not statistically significant. The remote sensing approach developed in this study can be easily applied to recent sensors such as Sentinel-2 or Landsat-8

  17. Changes in the planning target volume and liver volume dose based on the selected respiratory phase in respiratory-gated radiation therapy for a hepatocellular carcinoma

    Science.gov (United States)

    Lee, Jae-Seung; Im, In-Chul; Kang, Su-Man; Goo, Eun-Hoe; Baek, Seong-Min

    2013-11-01

    The aim of this study was to quantitatively analyze the changes in the planning target volume (PTV) and liver volume dose based on the respiratory phase to identify the optimal respiratory phase for respiratory-gated radiation therapy for a hepatocellular carcinoma (HCC). Based on the standardized procedure for respiratory-gated radiation therapy, we performed a 4-dimensional computed tomography simulation for 0 ˜ 90%, 30 ˜ 70%, and 40 ˜ 60% respiratory phases to assess the respiratory stability (S R ) and the defined PTV i for each respiratory phase i. A treatment plan was established, and the changes in the PTV i and dose volume of the liver were quantitatively analyzed. Most patients (91.5%) passed the respiratory stability test (S R = 0.111 ± 0.015). With standardized respiration training exercises, we were able to minimize the overall systematic error caused by irregular respiration. Furthermore, a quantitative analysis to identify the optimal respiratory phase revealed that when a short respiratory phase (40 ˜ 60%) was used, the changes in the PTV were concentrated inside the center line; thus, we were able to obtain both a PTV margin accounting for respiration and a uniform radiation dose within the PTV.

  18. Climate-induced boreal forest change: Predictions versus current observations

    Science.gov (United States)

    Soja, Amber J.; Tchebakova, Nadezda M.; French, Nancy H. F.; Flannigan, Michael D.; Shugart, Herman H.; Stocks, Brian J.; Sukhinin, Anatoly I.; Parfenova, E. I.; Chapin, F. Stuart; Stackhouse, Paul W.

    2007-04-01

    For about three decades, there have been many predictions of the potential ecological response in boreal regions to the currently warmer conditions. In essence, a widespread, naturally occurring experiment has been conducted over time. In this paper, we describe previously modeled predictions of ecological change in boreal Alaska, Canada and Russia, and then we investigate potential evidence of current climate-induced change. For instance, ecological models have suggested that warming will induce the northern and upslope migration of the treeline and an alteration in the current mosaic structure of boreal forests. We present evidence of the migration of keystone ecosystems in the upland and lowland treeline of mountainous regions across southern Siberia. Ecological models have also predicted a moisture-stress-related dieback in white spruce trees in Alaska, and current investigations show that as temperatures increase, white spruce tree growth is declining. Additionally, it was suggested that increases in infestation and wildfire disturbance would be catalysts that precipitate the alteration of the current mosaic forest composition. In Siberia, 7 of the last 9 yr have resulted in extreme fire seasons, and extreme fire years have also been more frequent in both Alaska and Canada. In addition, Alaska has experienced extreme and geographically expansive multi-year outbreaks of the spruce beetle, which had been previously limited by the cold, moist environment. We suggest that there is substantial evidence throughout the circumboreal region to conclude that the biosphere within the boreal terrestrial environment has already responded to the transient effects of climate change. Additionally, temperature increases and warming-induced change are progressing faster than had been predicted in some regions, suggesting a potential non-linear rapid response to changes in climate, as opposed to the predicted slow linear response to climate change.

  19. Climate-Induced Boreal Forest Change: Predictions versus Current Observations

    Science.gov (United States)

    Soja, Amber J.; Tchebakova, Nadezda M.; French, Nancy H. F.; Flannigan, Michael D.; Shugart, Herman H.; Stocks, Brian J.; Sukhinin, Anatoly I.; Parfenova, E. I.; Chapin, F. Stuart, III; Stackhouse, Paul W., Jr.

    2007-01-01

    For about three decades, there have been many predictions of the potential ecological response in boreal regions to the currently warmer conditions. In essence, a widespread, naturally occurring experiment has been conducted over time. In this paper, we describe previously modeled predictions of ecological change in boreal Alaska, Canada and Russia, and then we investigate potential evidence of current climate-induced change. For instance, ecological models have suggested that warming will induce the northern and upslope migration of the treeline and an alteration in the current mosaic structure of boreal forests. We present evidence of the migration of keystone ecosystems in the upland and lowland treeline of mountainous regions across southern Siberia. Ecological models have also predicted a moisture-stress-related dieback in white spruce trees in Alaska, and current investigations show that as temperatures increase, white spruce tree growth is declining. Additionally, it was suggested that increases in infestation and wildfire disturbance would be catalysts that precipitate the alteration of the current mosaic forest composition. In Siberia, five of the last seven years have resulted in extreme fire seasons, and extreme fire years have also been more frequent in both Alaska and Canada. In addition, Alaska has experienced extreme and geographically expansive multi-year outbreaks of the spruce beetle, which had been previously limited by the cold, moist environment. We suggest that there is substantial evidence throughout the circumboreal region to conclude that the biosphere within the boreal terrestrial environment has already responded to the transient effects of climate change. Additionally, temperature increases and warming-induced change are progressing faster than had been predicted in some regions, suggesting a potential non-linear rapid response to changes in climate, as opposed to the predicted slow linear response to climate change.

  20. Is choice-induced preference change long lasting?

    Science.gov (United States)

    Sharot, Tali; Fleming, Stephen M; Yu, Xiaoyu; Koster, Raphael; Dolan, Raymond J

    2012-10-01

    The idea that decisions alter preferences has had a considerable influence on the field of psychology and underpins cognitive dissonance theory. Yet it is unknown whether choice-induced changes in preferences are long lasting or are transient manifestations seen in the immediate aftermath of decisions. In the research reported here, we investigated whether these changes in preferences are fleeting or stable. Participants rated vacation destinations before making hypothetical choices between destinations, immediately afterward, and 2.5 to 3 years later. We found that choices altered preferences both immediately after being made and after the delay. These changes could not be accounted for by participants' preexisting preferences, and they occurred only when participants made the choices themselves. Our findings provide evidence that making a decision can lead to enduring change in preferences.

  1. Corticostriatal Plastic Changes in Experimental L-DOPA-Induced Dyskinesia

    Directory of Open Access Journals (Sweden)

    Veronica Ghiglieri

    2012-01-01

    Full Text Available In Parkinson’s disease (PD, alteration of dopamine- (DA- dependent striatal functions and pulsatile stimulation of DA receptors caused by the discontinuous administration of levodopa (L-DOPA lead to a complex cascade of events affecting the postsynaptic striatal neurons that might account for the appearance of L-DOPA-induced dyskinesia (LID. Experimental models of LID have been widely used and extensively characterized in rodents and electrophysiological studies provided remarkable insights into the inner mechanisms underlying L-DOPA-induced corticostriatal plastic changes. Here we provide an overview of recent findings that represent a further step into the comprehension of mechanisms underlying maladaptive changes of basal ganglia functions in response to L-DOPA and associated to development of LID.

  2. Mining-Induced Coal Permeability Change Under Different Mining Layouts

    Science.gov (United States)

    Zhang, Zetian; Zhang, Ru; Xie, Heping; Gao, Mingzhong; Xie, Jing

    2016-09-01

    To comprehensively understand the mining-induced coal permeability change, a series of laboratory unloading experiments are conducted based on a simplifying assumption of the actual mining-induced stress evolution processes of three typical longwall mining layouts in China, i.e., non-pillar mining (NM), top-coal caving mining (TCM) and protective coal-seam mining (PCM). A theoretical expression of the mining-induced permeability change ratio (MPCR) is derived and validated by laboratory experiments and in situ observations. The mining-induced coal permeability variation under the three typical mining layouts is quantitatively analyzed using the MPCR based on the test results. The experimental results show that the mining-induced stress evolution processes of different mining layouts do have an influence on the mechanical behavior and evolution of MPCR of coal. The coal mass in the PCM simulation has the lowest stress concentration but the highest peak MPCR (approximately 4000 %), whereas the opposite trends are observed for the coal mass under NM. The results of the coal mass under TCM fall between those for PCM and NM. The evolution of the MPCR of coal under different layouts can be divided into three sections, i.e., stable increasing section, accelerated increasing section and reducing section, but the evolution processes are slightly different for the different mining layouts. A coal bed gas intensive extraction region is recommended based on the MPCR distribution of coal seams obtained by simplifying assumptions and the laboratory testing results. The presented results are also compared with existing conventional triaxial compression test results to fully comprehend the effect of actual mining-induced stress evolution on coal property tests.

  3. Three Decades of Volume Change of a Small Greenlandic Glacier Using Ground Penetrating Radar, Structure from Motion, and Aerial Photogrammetry

    DEFF Research Database (Denmark)

    Marcer, M.; Stentoft, Peter Alexander; Bjerre, Elisa

    2017-01-01

    Glaciers in the Arctic are losing mass at an increasing rate. Here we use surface topography derived from Structure from Motion (SfM) and ice volume from ground penetrating radar (GPR) to describe the 2014 state of Aqqutikitsoq glacier (2.85 km) on Greenland's west coast. A photogrammetrically...... topography, the approach constitutes a viable alternative where the use of drones is not possible. Our investigations constitute the first glacier on Greenland's west coast where ice volume was determined and volume change calculated. The glacier's thinning rate is comparable to, for example, the Swiss Alps...

  4. Volume changes at macro- and nano-scale in epoxy resins studied by PALS and PVT experimental techniques

    Energy Technology Data Exchange (ETDEWEB)

    Somoza, A. [IFIMAT-UNCentro, Pinto 399, B7000GHG Tandil (Argentina) and CICPBA, Pinto 399, B7000GHG Tandil (Argentina)]. E-mail: asomoza@exa.unicen.edu.ar; Salgueiro, W. [IFIMAT-UNCentro, Pinto 399, B7000GHG Tandil (Argentina); Goyanes, S. [LPMPyMC, Depto. de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellon I, 1428 Buenos Aires (Argentina); Ramos, J. [Materials and Technology Group, Departamento de Ingenieria Quimica y M. Ambiente, Escuela University Politecnica, Universidad Pais Vasco/Euskal Herriko Unibertsitatea, Pz. Europa 1, 20018 Donostia/San Sebastian (Spain); Mondragon, I. [Materials and Technology Group, Departamento de Ingenieria Quimica y M. Ambiente, Escuela University Politecnica, Universidad Pais Vasco/Euskal Herriko Unibertsitatea, Pz. Europa 1, 20018 Donostia/San Sebastian (Spain)

    2007-02-15

    A systematic study on changes in the volumes at macro- and nano-scale in epoxy systems cured with selected aminic hardeners at different pre-cure temperatures is presented. Free- and macroscopic specific-volumes were measured by PALS and pressure-volume-temperature techniques, respectively. An analysis of the relation existing between macro- and nano-scales of the thermosetting networks developed by the different chemical structures is shown. The result obtained indicates that the structure of the hardeners governs the packing of the molecular chains of the epoxy network.

  5. Strain-induced changes to the electronic structure of germanium

    KAUST Repository

    Tahini, H. A.

    2012-04-17

    Density functional theory calculations (DFT) are used to investigate the strain-induced changes to the electronic structure of biaxially strained (parallel to the (001), (110) and (111) planes) and uniaxially strained (along the [001], [110] and [111] directions) germanium (Ge). It is calculated that a moderate uniaxial strain parallel to the [111] direction can efficiently transform Ge to a direct bandgap material with a bandgap energy useful for technological applications. © 2012 IOP Publishing Ltd.

  6. Iodine fortification may influence the age-related change in thyroid volume

    DEFF Research Database (Denmark)

    Motavaf, Anne Krejbjerg; Pedersen, Inge Bülow; Bjergved, Lena

    2014-01-01

    , increased series-resistance losses, and potential-induced degradation of the PV generator by analysing changes its current-voltage characteristic curve. The diagnostic method is based on parameters that can be easily calculated from the shape of the current-voltage curve, making it machine-analysis friendly...... and analysis of the diagnostic parameters and logic was performed based on module level tests on standard crystalline silicon PV modules, and were optimized to detect even small partial shading and increase series-resistance losses. To demonstrate the practical application and operation of this method...

  7. Regional brain volumes, diffusivity, and metabolite changes after electroconvulsive therapy for severe depression

    DEFF Research Database (Denmark)

    Jørgensen, A.; Magnusson, P.; Hanson, Lars G.

    2016-01-01

    , and metabolite changes in 19 patients receiving ECT for severe depression. Other regions of interest included the amygdala, dorsolateral prefrontal cortex (DLPFC), orbitofrontal cortex, and hypothalamus. Patients received a 3T MR scan before ECT (TP1), 1 week (TP2), and 4 weeks (TP3) after ECT. Results......, and we were unable to identify a spectral signature at 1.30 ppm previously suggested to reflect neurogenesis induced by ECT. None of the brain imaging measures correlated to the clinical response. Conclusion: Our findings show that ECT causes a remodeling of brain structures involved in affective...

  8. Structural changes of linear DNA molecules induced by cisplatin

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Zhiguo, E-mail: cn.zguoliu@yahoo.com [State Engineering Laboratory of Bio-Resource Eco-Utilization, Harbin 150040 (China); Engineering Research Center of Forest Bio-preparation, Ministry of Education, Northeast Forestry University, Harbin 150040 (China); Key Laboratory of Forest Plant Ecology of Ministry of Education, Northeast Forestry University, Harbin 150040 (China); Liu, Ruisi; Zhou, Zhen; Zu, Yuangang; Xu, Fengjie [State Engineering Laboratory of Bio-Resource Eco-Utilization, Harbin 150040 (China); Engineering Research Center of Forest Bio-preparation, Ministry of Education, Northeast Forestry University, Harbin 150040 (China); Key Laboratory of Forest Plant Ecology of Ministry of Education, Northeast Forestry University, Harbin 150040 (China)

    2015-02-20

    Interaction between long DNA molecules and activated cisplatin is believed to be crucial to anticancer activity. However, the exact structural changes of long DNA molecules induced by cisplatin are still not very clear. In this study, structural changes of long linear double-stranded DNA (dsDNA) and short single-stranded DNA (ssDNA) induced by activated cisplatin have been investigated by atomic force microscopy (AFM). The results indicated that long DNA molecules gradually formed network structures, beads-on-string structures and their large aggregates. Electrostatic and coordination interactions were considered as the main driving forces producing these novel structures. An interesting finding in this study is the beads-on-string structures. Moreover, it is worth noting that the beads-on-string structures were linked into the networks, which can be ascribed to the strong DNA–DNA interactions. This study expands our knowledge of the interactions between DNA molecules and cisplatin. - Highlights: • We investigate structural changes of dsDNA and ssDNA induced by cisplatin. • AFM results indicated long dsDNA formed network, beads-on-string and aggregates. • ssDNA can form very similar structures as those of long linear dsDNA. • A possible formation process of theses novel structure is proposed.

  9. Quantification of cerebral ventricle volume change of preterm neonates using 3D ultrasound images

    Science.gov (United States)

    Chen, Yimin; Kishimoto, Jessica; Qiu, Wu; de Ribaupierre, Sandrine; Fenster, Aaron; Chiu, Bernard

    2015-03-01

    Intraventricular hemorrhage (IVH) is a major cause of brain injury in preterm neonates. Quantitative measurement of ventricular dilation or shrinkage is important for monitoring patients and in evaluation of treatment options. 3D ultrasound (US) has been used to monitor the ventricle volume as a biomarker for ventricular dilation. However, volumetric quantification does not provide information as to where dilation occurs. The location where dilation occurs may be related to specific neurological problems later in life. For example, posterior horn enlargement, with thinning of the corpus callosum and parietal white matter fibres, could be linked to poor visuo-spatial abilities seen in hydrocephalic children. In this work, we report on the development and application of a method used to analyze local surface change of the ventricles of preterm neonates with IVH from 3D US images. The technique is evaluated using manual segmentations from 3D US images acquired in two imaging sessions. The surfaces from baseline and follow-up were registered and then matched on a point-by-point basis. The distance between each pair of corresponding points served as an estimate of local surface change of the brain ventricle at each vertex. The measurements of local surface change were then superimposed on the ventricle surface to produce the 3D local surface change map that provide information on the spatio-temporal dilation pattern of brain ventricles following IVH. This tool can be used to monitor responses to different treatment options, and may provide important information for elucidating the deficiencies a patient will have later in life.

  10. Training-induced changes on blood lactate profile and critical velocity in young swimmers.

    Science.gov (United States)

    Toubekis, Argyris G; Tsami, Aikaterini P; Smilios, Ilias G; Douda, Helen T; Tokmakidis, Savvas P

    2011-06-01

    This study examines the efficacy of critical swimming velocity (CV) for training prescription and monitoring the changes induced on aerobic endurance after a period of increased training volume in young swimmers. An experimental group (E: n = 7; age: 13.3 ± 1.3 years), which participated in competitive training was tested at the beginning (W0), the sixth week (W6), and 14th week (W14) to compare the changes of aerobic endurance indexes (CV; lactate threshold [LT]; velocity corresponding to blood lactate concentration of 4 mmol · L: V4). A control group (C: n = 7; age: 14.1 ± 1.6 years), which refrained from competitive training, was used to observe maturation effects and was tested for CV changes between W0 and W14. The average weekly training volume was increased after the sixth week in the E group and was unchanged for the C group. The CV was not different between or within groups at W0 and W14 (p > 0.05). The LT of the E group was no different compared to V4 and CV at W0 and W6 (p > 0.05) but was higher than CV at W14 (p 0.05). LT, V4, and CV were unchanged despite the increased training volume from W6 to W14 (LT: 1.2 ± 4.3%, V4: 0.8 ± 1.5%, CV: 0.3 ± 0.8%; p > 0.05). These findings suggest that CV pace may be effectively used for the improvement of aerobic endurance in young swimmers. The aerobic endurance indexes used for the assessment of swimmers' progression showed different rates of change as a response to the same training stimulus and cannot be used interchangeably for training planning.

  11. Early changes of volume and spatial location in target and normal tissues caused by IMRT for cervical cancer.

    Science.gov (United States)

    Chen, Jianwu; Liu, Ping; Chen, Wenjuan; Bai, Penggang; Li, Jiangshan; Ni, Xiaolei; Chen, Kaiqiang; Li, Qixin

    2016-12-01

    To investigate the early changes of volume and spatial location in target and normal tissues caused by intensity-modulated radiotherapy (IMRT) for cervical cancer. Forty patients with cervical cancer were included in this study and treated by IMRT. Computed tomography (CT) was performed before radiotherapy and when the patient had received 27 Gy in 15 fractions. After image registration, the volume of interest (VOI) for the targets and organs at risk was delineated by clinicians on the CT images. Changes of volume, spatial location and Dice similarity were calculated for all VOIs. There were significant changes in gross tumor volume (GTV) in the primary tumor (GTV-T) with t = 8.304 (p<0.01) and visible pelvic lymph nodes (GTV-N) with t = 4.996 (p<0.01) caused by IMRT. The mean volume differences for GTV-T and GTV-N were 38.64% ± 19.50% (range 3.16%-86.49%) and 42.49% ± 25.68% (range 2.79%-87.42%), respectively. Among the organs at risk, the bladder had the greatest volume change with 55.13% ± 33.40% (range 3.25%-116.01%). The Dice similarity for GTV-T and GTV-N was 0.50 ± 0.18 (range 0.10-0.85) and 0.31 ± 0.20 (range 0.00-0.71), respectively. The rectum had the least Dice similarity among the normal tissues, with a mean value of 0.57 ± 0.14 (range 0.18-0.76). There were significant changes in volume and spatial location of the target and normal tissues after 27 Gy IMRT. In order to maintain the radiation dose to the targets and minimize the radiation to normal tissues, it is necessary to modify the radiotherapy planning.

  12. Tubular system volume changes in twitch fibres from toad and rat skeletal muscle assessed by confocal microscopy.

    Science.gov (United States)

    Launikonis, Bradley S; Stephenson, D George

    2002-01-15

    The volume of the extracellular compartment (tubular system) within intact muscle fibres from cane toad and rat was measured under various conditions using confocal microscopy. Under physiological conditions at rest, the fractional volume of the tubular system (t-sys(Vol)) was 1.38 +/- 0.09 % (n = 17), 1.41 +/- 0.09 % (n = 12) and 0.83 +/- 0.07 % (n = 12) of the total fibre volume in the twitch fibres from toad iliofibularis muscle, rat extensor digitorum longus muscle and rat soleus muscle, respectively. In toad muscle fibres, the t-sys(Vol) decreased by 30 % when the tubular system was fully depolarized and decreased by 15 % when membrane cholesterol was depleted from the tubular system with methyl-beta-cyclodextrin but did not change as the sarcomere length was changed from 1.93 to 3.30 microm. There was also an increase by 30 % and a decrease by 25 % in t-sys(Vol) when toad fibres were equilibrated in solutions that were 2.5-fold hypertonic and 50 % hypotonic, respectively. When the changes in total fibre volume were taken into consideration, the t-sys(Vol) expressed as a percentage of the isotonic fibre volume did actually decrease as tonicity increased, revealing that the tubular system in intact fibres cannot be compressed below 0.9 % of the isotonic fibre volume. The results can be explained in terms of forces acting at the level of the tubular wall. These observations have important physiological implications showing that the tubular system is a dynamic membrane structure capable of changing its volume in response to the membrane potential, cholesterol depletion and osmotic stress but not when the sarcomere length is changed in resting muscle.

  13. Effects of dynamic changes of tissue properties during laser-induced interstitial thermotherapy (LITT).

    Science.gov (United States)

    Jiang, S C; Zhang, X X

    2005-01-01

    A two-dimensional model including the effects of dynamic changes in the physical properties on tissue temperature and damage was developed to describe laser energy transport, heat transfer, and damage accumulation during laser-induced interstitial thermotherapy (LITT). The Monte Carlo method was used to simulate photon transport in a tissue in the nonuniform optical property field, with the finite difference method used to solve the Pennes bioheat equation to calculate the temperature distribution and the Arrhenius equation used to predict the extent of thermal damage. The numerical results showed that the dynamic changes in the optical properties, thermal properties, and blood perfusion rate significantly affected damage volume accumulation and temperature history and should be included in numerical simulations of the LITT treatment.

  14. Volume and expansivity changes of micelle formation measured by pressure perturbation calorimetry.

    Science.gov (United States)

    Fan, Helen Y; Nazari, Mozhgan; Chowdhury, Saria; Heerklotz, Heiko

    2011-03-01

    We present the application of pressure perturbation calorimetry (PPC) as a new method for the volumetric characterization of the micelle formation of surfactants. The evaluation is realized by a global fit of PPC curves at different surfactant concentration ranging, if possible, from below to far above the CMC. It is based on the knowledge of the temperature dependence of the CMC, which can for example be characterized by isothermal titration calorimetry. We demonstrate the new approach for decyl-β-maltopyranoside (DM). It shows a strong volume increase upon micelle formation of 16 ± 2.5 mL/mol (+4%) at 25 °C, and changes with temperature by -0.1 mL/(mol K). The apparent molar expansivity (E(S)) decreases upon micelle formation from 0.44 to 0.31 mL/(mol K) at 25 °C. Surprisingly, the temperature dependence of the expansivity of DM in solution (as compared with that of maltose) does not agree with the principal behavior described for polar (E(S)(T) decreasing) and hydrophobic (E(S)(T) increasing) solutes or moieties before. The results are discussed in terms of changes in hydration of the molecules and internal packing of the micelles and compared with the volumetric effects of transitions of proteins, DNA, lipids, and polymers.

  15. Effect of temperature on volume change behaviour of statically compacted kaolin clay

    Directory of Open Access Journals (Sweden)

    Ileme Ogechi

    2016-01-01

    Full Text Available Several soils are subjected to high temperature due to the environment where they are located or activities around them. For instance, upper layer of soils in tropical regions, soils around geothermal structures, clay barriers around nuclear waste repository systems. Numerous studies have pointed out that high temperature affects the hydro-mechanical properties of soils. Notwithstanding already existing studies, the influence of temperature on soils is still a challenge, as most of these studies are soil specific and cannot be inferred as the behaviour of all soils. This paper presents an experimental study on the influence of temperature on the volume change behaviour of statically compacted kaolin clay. Compacted samples were tested at varying temperatures using a suction controlled oedometer cell. The influence of temperature on the magnitude of volumetric strain occurring during mechanical and thermal loading was investigated. The study showed that an increase in temperature increased the magnitude of volumetric strain of the soil on loading. Additionally, the results presented in the light of LC curve showed that an increase in temperature resulted in the contraction and a change in the position of the LC curve.

  16. Traditional Medicare Versus Private Insurance: How Spending, Volume, And Price Change At Age Sixty-Five.

    Science.gov (United States)

    Wallace, Jacob; Song, Zirui

    2016-05-01

    To slow the growth of Medicare spending, some policy makers have advocated raising the Medicare eligibility age from the current sixty-five years to sixty-seven years. For the majority of affected adults, this would delay entry into Medicare and increase the time they are covered by private insurance. Despite its policy importance, little is known about how such a change would affect national health care spending, which is the sum of health care spending for all consumers and payers-including governments. We examined how spending differed between Medicare and private insurance using longitudinal data on imaging and procedures for a national cohort of individuals who switched from private insurance to Medicare at age sixty-five. Using a regression discontinuity design, we found that spending fell by $38.56 per beneficiary per quarter-or 32.4 percent-upon entry into Medicare at age sixty-five. In contrast, we found no changes in the volume of services at age sixty-five. For the previously insured, entry into Medicare led to a large drop in spending driven by lower provider prices, which may reflect Medicare's purchasing power as a large insurer. These findings imply that increasing the Medicare eligibility age may raise national health care spending by replacing Medicare coverage with private insurance, which pays higher provider prices than Medicare does.

  17. Islands of surviving cells within necrotic volume at liver induced by PDT

    Science.gov (United States)

    Ferreira, J.; Kurachi, C.; Zucoloto, S.; Castro e Silva, O., Jr.; Bagnato, V. S.

    2009-06-01

    Tissue heterogeneities as well as distinct metabolic status and cellular types within a tumor may results in a nonhomogenous necrosis. The possibility of PDT surviving cells within a treated volume has relevant clinical significance. The major aim of this study was to analyze, on normal rat liver, the cell viability and surviving after PDT. The porphyrin was injected through the cava vein at concentration of 1.5 mg/Kg. The induced necrosis was qualitatively investigated varying the used drug light interval (30 min, 1, 3, 6, 24 and 36 h) and total delivered dose (20, 50, 100, 150 and 200 J/cm2). A diode laser at 630 nm and irradiance of 150 mW/cm2 was employed. The exposed livers were removed after the animals were killed by anesthesia overdose, 30 h after illumination. Slides were processed by HE analysis for the determination of the overall aspects of the necrotic and non-treated liver. We observed necrosis of central vein and presence of surviving cell around the portal triad within the necrotic volume, suggesting PDT-resistant regions of the tissue. Possible hypothesis for the observation may be: the absence of photosensitizer; insufficient light dose (below threshold); and distinct metabolic status in the portal triad microregions decreases oxygen availability to photodynamic reaction. The cells surrounding portal triad presented a higher resistance even when 200 J/cm2 was applied. In contrast, the cells closer to the central vein after 20 J/cm2 were already susceptible to the action of PDT. Different aspects of the problem are presented.

  18. Light-induced structural changes in a monomeric bacteriophytochrome

    Directory of Open Access Journals (Sweden)

    Heikki Takala

    2016-09-01

    Full Text Available Phytochromes sense red light in plants and various microorganism. Light absorption causes structural changes within the protein, which alter its biochemical activity. Bacterial phytochromes are dimeric proteins, but the functional relevance of this arrangement remains unclear. Here, we use time-resolved X-ray scattering to reveal the solution structural change of a monomeric variant of the photosensory core module of the phytochrome from Deinococcus radiodurans. The data reveal two motions, a bend and a twist of the PHY domain with respect to the chromophore-binding domains. Infrared spectroscopy shows the refolding of the PHY tongue. We conclude that a monomer of the phytochrome photosensory core is sufficient to perform the light-induced structural changes. This implies that allosteric cooperation with the other monomer is not needed for structural activation. The dimeric arrangement may instead be intrinsic to the biochemical output domains of bacterial phytochromes.

  19. Regional cosmic ray induced ionization and geomagnetic field changes

    Directory of Open Access Journals (Sweden)

    G. A. Kovaltsov

    2007-08-01

    Full Text Available Cosmic ray induced ionization (CRII is an important factor of outer space influences on atmospheric properties. Variations of CRII are caused by two different processes – solar activity variations, which modulate the cosmic ray flux in interplanetary space, and changes of the geomagnetic field, which affects the cosmic ray access to Earth. Migration of the geomagnetic dipole axis may greatly alter CRII in some regions on a time scale of centuries and longer. Here we present a study of CRII regional effects of the geomagnetic field changes during the last millennium for two regions: Europe and the Far East. We show that regional effects of the migration of the geomagnetic dipole axis may overcome global changes due to solar activity variations.

  20. Major rapid weight loss induces changes in cardiac repolarization

    DEFF Research Database (Denmark)

    Vedel-Larsen, Esben; Iepsen, Eva Winning; Lundgren, Julie

    2016-01-01

    INTRODUCTION: Obesity is associated with increased all-cause mortality, but weight loss may not decrease cardiovascular events. In fact, very low calorie diets have been linked to arrhythmias and sudden death. The QT interval is the standard marker for cardiac repolarization, but T-wave morphology...... analysis has been suggested as a more sensitive method to identify changes in cardiac repolarization. We examined the effect of a major and rapid weight loss on T-wave morphology. METHODS AND RESULTS: Twenty-six individuals had electrocardiograms (ECG) taken before and after eight weeks of weight loss......A1c (pweight loss induces changes in cardiac repolarization. Monitoring of MCS during calorie restriction makes it possible to detect repolarization changes with higher discriminative power than the QT-interval during major rapid weight...

  1. Acute volume expansion attenuates hyperthermia-induced reductions in cerebral perfusion during simulated hemorrhage

    DEFF Research Database (Denmark)

    Schlader, Zachary J; Seifert, Thomas; Wilson, Thad E

    2013-01-01

    Hyperthermia reduces the capacity to withstand a simulated hemorrhagic challenge, but volume loading preserves this capacity. This study tested the hypotheses that acute volume expansion during hyperthermia increases cerebral perfusion and attenuates reductions in cerebral perfusion during a simu...

  2. Mild hypothermia attenuates changes in respiratory system mechanics and modifies cytokine concentration in bronchoalveolar lavage fluid during low lung volume ventilation.

    Science.gov (United States)

    Dostál, P; Senkeřík, M; Pařízková, R; Bareš, D; Zivný, P; Zivná, H; Cerný, V

    2010-01-01

    Hypothermia was shown to attenuate ventilator-induced lung injury due to large tidal volumes. It is unclear if the protective effect of hypothermia is maintained under less injurious mechanical ventilation in animals without previous lung injury. Tracheostomized rats were randomly allocated to non-ventilated group (group C) or ventilated groups of normothermia (group N) and mild hypothermia (group H). After two hours of mechanical ventilation with inspiratory fraction of oxygen 1.0, respiratory rate 60 min(-1), tidal volume 10 ml x kg(-1), positive end-expiratory pressure (PEEP) 2 cm H2O or immediately after tracheostomy in non-ventilated animals inspiratory pressures were recorded, rats were sacrificed, pressure-volume (PV) curve of respiratory system constructed, bronchoalveolar lavage (BAL) fluid and aortic blood samples obtained. Group N animals exhibited a higher rise in peak inspiratory pressures in comparison to group H animals. Shift of the PV curve to right, higher total protein and interleukin-6 levels in BAL fluid were observed in normothermia animals in comparison with hypothermia animals and non-ventilated controls. Tumor necrosis factor-alpha was lower in the hypothermia group in comparison with normothermia and non-ventilated groups. Mild hypothermia attenuated changes in respiratory system mechanics and modified cytokine concentration in bronchoalveolar lavage fluid during low lung volume ventilation in animals without previous lung injury.

  3. Separating triggered and stress-change induced seismcity

    Science.gov (United States)

    Zhuang, J.

    2013-12-01

    Once a major earthquake occurs, it usually not only triggers a sequence of many aftershock, but also changes the tectonic stress field in the regions nearby. According to the rate and state law (Dieterich, 1994), such stress changes result in a permanent change of the seismicity rate, increment or decrement. However, since aftershock sequence lasts quite a long time before it decays off, it is hard tell whether the high level of seismicity after a big earthquake is the continuation of the aftershock activity or caused by the changes of stress due this big earthquake. In this study, by making use of the space-time ETAS model (Ogata, 1998) and the stochastic declustering method (Zhuang et al., 2002, 2004), I developed a method to separate the seismicity induced by stress-change from the aftershock activity in a probability manner. For example, it is found that the probabilities that Lushan earthquakes belong the background seismcity, aftershock of the Wenchuan earthquake, are stress-change induced seismcity are, respectively, 38% and 12%, 50%. References Dieterich, J.H. (1994) A constitutive law for rate of earthquake production and its application to earthquake clustering, J. Geophys. Res. , 99 , 2601-2618. Ogata, Y. (1998. Space-time point-process models for earthquake occur- rences, Ann. Inst. Stat. Math., 50, 379-402. Zhuang J., Ogata Y. and Vere-Jones D. (2004). Analyzing earthquake clustering features by using stochastic reconstruction. Journal of Geophysical Research, 109, No. B5, B05301, doi:10.1029/2003JB002879. Zhuang J., Ogata Y. and Vere-Jones D. (2002). Stochastic declustering of space-time earthquake occurrences. Journal of the American Statistical Association, 97: 369-380.

  4. Wind induces variations in spider web geometry and sticky spiral droplet volume.

    Science.gov (United States)

    Wu, Chao-Chia; Blamires, Sean J; Wu, Chung-Lin; Tso, I-Min

    2013-09-01

    Trap building by animals is rare because it comes at a substantial cost. Using materials with properties that vary across environments maintains trap functionality. The sticky spiral silks of spider orb webs are used to catch flying prey. Web geometry, accompanied by compensatory changes in silk properties, may change across environments to sustain web functionality. We exposed the spider Cyclosa mulmeinensis to wind to test whether wind-induced changes in web geometry are accompanied by changes in aggregate silk droplet morphology, axial thread width or spiral stickiness. We compared: (i) web catching area, (ii) length of total silks, (iii) mesh height, (iv) number of radii, (v) aggregate droplet morphology and (vi) spiral thread stickiness, between webs made by spiders exposed to wind and those made by spiders not exposed to wind. We interpreted co-variation in droplet morphology or spiral stickiness with web capture area, mesh height or spiral length as the silk properties functionally compensating for changes in web geometry to reduce wind drag. Wind-exposed C. mulmeinensis built webs with smaller capture areas, shorter capture spiral lengths and more widely spaced capture spirals, resulting in the expenditure of less silk. Individuals that were exposed to wind also deposited larger droplets of sticky silk but the stickiness of the spiral threads remained unchanged. The larger droplets may be a product of a greater investment in water, or low molecular weight compounds facilitating atmospheric water uptake. Either way, droplet dehydration in wind is likely to be minimized.

  5. Variations of the earth's magnetic field and rapid climatic cooling: A possible link through changes in global ice volume

    Science.gov (United States)

    Rampino, M. R.

    1979-01-01

    A possible relationship between large scale changes in global ice volume, variations in the earth's magnetic field, and short term climatic cooling is investigated through a study of the geomagnetic and climatic records of the past 300,000 years. The calculations suggest that redistribution of the Earth's water mass can cause rotational instabilities which lead to geomagnetic excursions; these magnetic variations in turn may lead to short-term coolings through upper atmosphere effects. Such double coincidences of magnetic excursions and sudden coolings at times of ice volume changes have occurred at 13,500, 30,000, 110,000, and 135,000 YBP.

  6. White matter volume change and its correlation with symptom severity in patients with schizophrenia: a VBM-DARTEL study.

    Science.gov (United States)

    Kim, Gwang-Won; Jeong, Gwang-Woo

    2015-12-16

    The aim of this study was to evaluate the white matter (WM) volume change and its correlation with symptom severity in patients with schizophrenia using voxel-based morphometry. A total of 20 patients with schizophrenia and 20 age-matched healthy controls participated in this study. MR image data were processed using SPM8 software with diffeomorphic anatomical registration through an exponentiated Lie algebra (DARTEL) algorithm. The patients with schizophrenia showed significant decreases (P=0.042) in the WM volumes of the temporal lobe and superior frontal gyrus compared with the healthy controls. The WM volumes of the middle temporal gyrus were negatively correlated with the scores of both the Positive Subscale (Pearson's ρ=-0.68, P=0.001) and the Negative Subscale (ρ=-0.71, P=0.0005) in the Positive and Negative Syndrome Scale. In addition, the scores of the General Psychopathology Subscale were negatively correlated with the WM volumes of the superior frontal gyrus (ρ=-0.68, P=0.0009). This study evaluated the WM volume of patients with schizophrenia compared with healthy controls using DARTEI-based voxel-based morphometry and also assessed the correlation of the localized WM volume changes with the Positive and Negative Syndrome Scale. These findings will be useful to understand the neuropathology associated with WM abnormality in schizophrenia.

  7. Changes of orbital tissue volumes and proptosis in patients with thyroid extraocular muscle swelling after methylprednisolone pulse therapy.

    Science.gov (United States)

    Higashiyama, Tomoaki; Nishida, Yasuhiro; Ohji, Masahito

    2015-11-01

    To evaluate the changes of orbital tissue volumes and proptosis after methylprednisolone pulse therapy in thyroid-associated ophthalmopathy (TAO). The cross-sectional areas of orbital tissues and proptosis were measured with magnetic resonance imaging in 40 orbits of 20 patients with TAO before and after methylprednisolone pulse therapy. The volumes of the whole orbit, orbital fatty tissue, and extraocular muscles were calculated. The volumes and proptosis were compared before and after treatment using a paired t test. Before treatment, the mean volumes were 33.0 ± 4.8 cm(3) in the whole orbit, 19.9 ± 4.1 cm(3) in the orbital fatty tissue, and 4.6 ± 1.2 cm(3) in the total extraocular muscles. After treatment, the mean volumes were 32.5 ± 4.4 cm(3) in the whole orbit, 19.9 ± 3.7 cm(3) in the orbital fatty tissue, and 4.0 ± 1.0 cm(3) in the total extraocular muscles. The mean volumes of the whole orbit (P = 0.17) and orbital fatty tissue (P = 0.82) were not significantly decreased after treatment, while the mean volume of total extraocular muscles was significantly decreased (P tissue seemed to be unchanged after methylprednisolone pulse therapy while that of total extraocular muscles was decreased. The proptosis value seemed to be unchanged after treatment.

  8. Lithium-induced minimal change disease and acute kidney injury

    Directory of Open Access Journals (Sweden)

    Parul Tandon

    2015-01-01

    Full Text Available Context: Lithium carbonate is a psychiatric medication commonly used in the treatment of bipolar disorder. It has been implicated in inducing nephrogenic diabetes inspidus, chronic tubulointerstitial nephropathy, and acute tubular necrosis. We describe a case of lithium-induced minimal change disease (MCD and acute kidney injury (AKI. Case Report: A 32-year-old female with a medical history of bipolar disorder treated with chronic lithium therapy presented with anasarca, fatigue, and tremors. Work-up revealed supra-therapeutic lithium levels, hypoalbuminemia, and significant proteinuria. The patient was treated conservatively with fluids and discontinuation of lithium therapy. Subsequently, she developed significant AKI and persistent proteinuria. She underwent a renal biopsy that demonstrated effacement of podocyte foot processes consistent with lithium-induced MCD. This was treated with corticosteroids, which decreased the proteinuria and resolved all the patient′s symptoms. Conclusion: Lithium-induced MCD is a rare disease that affects patients of all ages. It is often associated with therapeutic lithium and is typically resolved with discontinuation of lithium. In some cases, concurrent AKI may result due to vascular obstruction from hyperalbuminuria and associated renal interstitial edema. Corticosteroids may be needed to reduce the proteinuria and prevent progression to chronic kidney disease. As such, patients on lithium therapy may benefit from monitoring of glomerular function via urinalysis to prevent the onset of nephrotic syndrome.

  9. Serotoninergic Modulation of Basal Cardiovascular Responses and Responses Induced by Isotonic Extracellular Volume Expansion in Rats

    Science.gov (United States)

    Semionatto, Isadora Ferraz; Raminelli, Adrieli Oliveira; Alves, Angelica Cristina; Capitelli, Caroline Santos; Chriguer, Rosangela Soares

    2017-01-01

    Background Isotonic blood volume expansion (BVE) induced alterations of sympathetic and parasympathetic activity in the heart and blood vessels, which can be modulated by serotonergic pathways. Objective To evaluate the effect of saline or serotonergic agonist (DOI) administration in the hypothalamic paraventricular nucleus (PVN) on cardiovascular responses after BVE. Methods We recorded pulsatile blood pressure through the femoral artery to obtain the mean arterial pressure (MAP), systolic (SBP) and diastolic blood pressure (DBP), heart rate (HR) and the sympathetic-vagal ratio (LF/HF) of Wistar rats before and after they received bilateral microinjections of saline or DOI into the PVN, followed by BVE. Results No significant differences were observed in the values of the studied variables in the different treatments from the control group. However, when animals are treated with DOI followed by BVE there is a significant increase in relation to the BE control group in all the studied variables: MBP (114.42±7.85 vs 101.34±9.17); SBP (147.23±14.31 vs 129.39±10.70); DBP (98.01 ±4.91 vs 87.31±8.61); HR (421.02±43.32 vs 356.35±41.99); and LF/HF ratio (2.32±0.80 vs 0.27±0.32). Discussion The present study showed that the induction of isotonic BVE did not promote alterations in MAP, HR and LF/HF ratio. On the other hand, the injection of DOI into PVN of the hypothalamus followed by isotonic BVE resulted in a significant increase of all variables. Conclusion These results suggest that serotonin induced a neuromodulation in the PVN level, which promotes an inhibition of the baroreflex response to BVE. Therefore, the present study suggests the involvement of the serotonergic system in the modulation of vagal reflex response at PVN in the normotensive rats. PMID:28099586

  10. CHARACTERIZATION OF PLASTICALLY-INDUCED STRUCTURAL CHANGES IN A Zr-BASED BULK METALLIC GLASS USING POSITRON ANNIHILATION SPECTROCOPY

    Energy Technology Data Exchange (ETDEWEB)

    Flores, K M; Kanungo, B P; Glade, S C; Asoka-Kumar, P

    2005-09-16

    Flow in metallic glasses is associated with stress-induced cooperative rearrangements of small groups of atoms involving the surrounding free volume. Understanding the details of these rearrangements therefore requires knowledge of the amount and distribution of the free volume and how that distribution evolves with deformation. The present study employs positron annihilation spectroscopy to investigate the free volume change in Zr{sub 58.5}Cu{sub 15.6}Ni{sub 12.8}Al{sub 10.3}Nb{sub 2.8} bulk metallic glass after inhomogeneous plastic deformation by cold rolling and structural relaxation by annealing. Results indicate that the size distribution of open volume sites is at least bimodal. The size and concentration of the larger group, identified as flow defects, changes with processing. Following initial plastic deformation the size of the flow defects increases, consistent with the free volume theory for flow. Following more extensive deformation, however, the size distribution of the positron traps shifts, with much larger open volume sites forming at the expense of the flow defects. This suggests that a critical strain is required for flow defects to coalesce and form more stable nanovoids, which have been observed elsewhere by high resolution TEM. Although these results suggest the presence of three distinct open volume size groups, further analysis indicates that all groups have the same line shape parameter. This is in contrast to the distinctly different interactions observed in crystalline materials with multiple defect types. This similarity may be due to the disordered structure of the glass and positron affinity to particular atoms surrounding open-volume regions.

  11. Changes in circulating blood volume after infusion of hydroxyethyl starch 6% in critically ill patients

    DEFF Research Database (Denmark)

    Christensen, P; Andersson, J; Rasmussen, S E;

    2001-01-01

    The cardiovascular response to a volume challenge with hydroxyethyl starch (HES) (200/0.5) 6% depends on the relation between the volume of HES 6% infused and the expansion of the blood volume in critically ill patients. However, only relatively limited data exist on the plasma expanding effect...... of infusion of HES 6% in critically ill patients. The purpose of the study was to evaluate the variation in the expansion of the circulating blood volume (CBV) in critically ill patients after infusion of 500 ml of colloid (HES (200/0.5) 6%) using the carbon monoxide method....

  12. Brain-volume changes in young and middle-aged smokers: a DARTEL-based voxel-based morphometry study.

    Science.gov (United States)

    Peng, Peng; Wang, Zhenchang; Jiang, Tao; Chu, Shuilian; Wang, Shuangkun; Xiao, Dan

    2015-09-25

    Many studies have reported brain volume changes in smokers. However, the volume differences of grey matter (GM) and white matter (WM) in young and middle-aged male smokers with different lifetime tobacco consumption (pack-years) remain uncertain. To examine the brain volume change, especially whether more pack-years smoking would be associated with smaller gray matter and white matter volume in young and middle-aged male smokers. We used a 3T MR scanner and performed Diffeomorphic anatomical registration through exponentiated lie algebra (DARTEL)-based voxel-based morphometry on 53 long-term male smokers (30.72 ± 4.19 years) and 53 male healthy non-smokers (30.83 ± 5.18 years). We separated smokers to light and heavy smokers by pack-years and compared brain volume between different smoker groups and non-smokers. And then we did analysis of covariance (ANCOVA) between smokers and non-smokers by setting pack-years as covariates. Light and heavy smokers all displayed smaller GM and WM volume than non-smokers and more obviously in heavy smokers. The main smaller areas in light and heavy smokers were superior temporal gyrus, insula, middle occipital gyrus, posterior cingulate, precuneus in GM and posterior cingulate, thalamus and midbrain in WM, in addition, we also observed more pack-years smoking was associated with some certain smaller GM and WM volumes by ANCOVA. Young and middle-aged male smokers had many smaller brain areas than non-smokers. Some of these areas' volume had negative correlation with pack-years, while some had not. These may due to different pathophysiological role of smokings. © 2015 John Wiley & Sons Ltd.

  13. Relations between slow extracellular potential changes, glial potassium buffering, and electrolyte and cellular volume changes during neuronal hyperactivity in cat brain.

    Science.gov (United States)

    Dietzel, I; Heinemann, U; Lux, H D

    1989-01-01

    The aim of this investigation is to estimate the contribution of spatial glial K+ buffer currents to extracellular K+ homeostasis during enhanced neuronal activity. Neuronal hyperactivity was induced by electrical stimulation of the cortical surface or the ventrobasal thalamic nuclei of cats (5-50 Hz, 0.1-0.2 ms, two to three times threshold stimulation intensity, 5-20 s). The accompanying slow field potential changes were recorded simultaneously across the grey matter with vertical assemblies of eight micropipettes glued 300 microns apart. Using the Poisson equation, the amplitudes of the underlying current sources and sinks were calculated. The current source densities depended on the depth of recording, frequency, strength, and duration of the stimulation. Current sinks, corresponding to a removal of 0.1-0.5 mmoles of monovalent cations per liter of brain tissue and second from the extracellular space, were observed in middle cortical layers, whereas sources appeared at superficial and deeper sites. These sinks and sources might represent K+ moved across glial membranes by spatial buffer currents. The consequences of glial buffer currents of this magnitude were investigated with model calculations. It turned out that measurements of electrolyte and volume changes of the extracellular space (Dietzel et al. Exp. Brain Res. 40:432-439, 1980; Exp. Brain Res. 46:73-84, 1982) could only partially be explained by spatial buffer currents of this magnitude. Comparison of the calculated values with intracellular measurements in neurons and glial cells (Coles et al. Ann. N.Y. Acad. Sci. 481:303-317, 1986; Ballanyi et al. J. Physiol. 382:159-174, 1987) suggests that spatial buffering combines with an approximately equimolar KCl transport and, depending on the preparation, also K+/Na+-exchange across glial membranes.

  14. [Soft tissues volumes changing in malar and cheek area after fat grafting].

    Science.gov (United States)

    Nadtochiy, A G; Grischenko, S V; Malitskaya, O A

    2016-01-01

    To improve the predictability of facial soft tissues fat grafting results tissue thickness dynamics before and 1 year postoperatively was assessed by means of ultrasonic method in 58 patients under standardized position of the ultrasonic transducer, physical and technical scanning conditions. The study revealed direct correlation of soft tissues thickness increase after fat grafting with the initial thickness of recipient area tissues. One year after fat grafting 60-65% of additional thickness remained in the lower regions of malar-cheek area (with the greatest soft tissues thickness), and only 25-27% preserved in the upper regions with the minimal initial thickness of soft tissues. I.e. to achieve necessary correction volume in a zone with small initial soft tissues thickness it is necessary to increase the amount of fat grafting stages. As the rates of soft tissues thickness in correction area change during 3-4 months after fat grafting remaining stable after this period it is expedient to assess postoperative results and to carry out repeated fat grafting not earlier than 4 months after operation.

  15. A chemical chaperone induces inhomogeneous conformational changes in flexible proteins.

    Science.gov (United States)

    Hamdane, Djemel; Velours, Christophe; Cornu, David; Nicaise, Magali; Lombard, Murielle; Fontecave, Marc

    2016-07-27

    Organic osmolytes also known as chemical chaperones are major cellular compounds that favor, by an unclear mechanism, protein's compaction and stabilization of the native state. Here, we have examined the chaperone effect of the naturally occurring trimethylamine N-oxide (TMAO) osmolyte on a loosely packed protein (LPP), known to be a highly flexible form, using an apoprotein mutant of the flavin-dependent RNA methyltransferase as a model. Thermal and chemical denaturation experiments showed that TMAO stabilizes the structural integrity of the apoprotein dramatically. The denaturation reaction is irreversible indicating that the stability of the apoprotein is under kinetic control. This result implies that the stabilization is due to a TMAO-induced reconfiguration of the flexible LPP state, which leads to conformational limitations of the apoprotein likely driven by favorable entropic contribution. Evidence for the conformational perturbation of the apoprotein had been obtained through several biophysical approaches notably analytical ultracentrifugation, circular dichroism, fluorescence spectroscopy, labelling experiments and proteolysis coupled to mass spectrometry. Unexpectedly, TMAO promotes an overall elongation or asymmetrical changes of the hydrodynamic shape of the apoprotein without alteration of the secondary structure. The modulation of the hydrodynamic properties of the protein is associated with diverse inhomogenous conformational changes: loss of the solvent accessible cavities resulting in a dried protein matrix; some side-chain residues initially buried become solvent exposed while some others become hidden. Consequently, the TMAO-induced protein state exhibits impaired capability in the flavin binding process. Our study suggests that the nature of protein conformational changes induced by the chemical chaperones may be specific to protein packing and plasticity. This could be an efficient mechanism by which the cell controls and finely tunes the

  16. Ultrasound as a Noninvasive Method to Assess Changes of Intracranial Volume and Pressure During Simulated Microgravity

    Science.gov (United States)

    Murthy, G.; Yost, W. T.; Ballard, R. E.; Watenpaugh, D. E.; Kawai, Y.; Hargens, A. R.

    1994-01-01

    Headaches are commonly experienced by astronauts in microgravity and by subjects undergoing head-down tilt (simulated microgravity on Earth). Exposure to microgravity probably elevates blood pressure and flow in the head which may increase intracranial volume (ICV) and pressure (ICP) and in turn cause headache. Due to the slightly compliant nature of the cranial vault and the encasement of brain and its vasculature within this vault, any increase of ICV will increase ICP and slightly distend the cranium. Previous studies document perivascular edema and increased ICP in rhesus monkeys during head-down tilt. Elevated ICP has also been reported in humans during head-down tilt. ICP measurements in healthy humans are rare because of the invasiveness of currently-available measurement techniques. Therefore, we proposed a noninvasive ultrasound technique to assess changes of ICV and JCP. The ultrasound principle is based on compliance of the cranial vault. A 450 kHz ultrasound stimulus is transmitted through the cranium by a transducer every 7.5-10 msec. The ultrasound wave enters the brain tissue, reflects off the opposite side of the cranium and is received by the same transducer. The detected wave is compared for phase quadrature (90 deg.to transmitted wave). Because the electronic circuitry of the device maintains a 90 deg. phase (phi), any alterations in the detected wave caused by an increase of ICV and ICP will be reflected as a change in the wave frequency. Phase shift is directly proportional to path length of the wave, DELTA x, which is expressed as DELTA x = phi lambda/2 pi where lambda is wavelength. Elevated ICV and ICP expand the cranial vault and increase path length of the wave (a measure of intracranial distance). Increased path length equals reduced frequency of the detected wave. Reduced frequency is then related to elevated ICP. This technique has potential uses for ICP studies of astronauts in space and head trauma patients on Earth.

  17. Light-induced metastable structural changes in hydrogenated amorphous silicon

    Energy Technology Data Exchange (ETDEWEB)

    Fritzsche, H. [Univ. of Chicago, IL (United States)

    1996-09-01

    Light-induced defects (LID) in hydrogenated amorphous silicon (a-Si:H) and its alloys limit the ultimate efficiency of solar panels made with these materials. This paper reviews a variety of attempts to find the origin of and to eliminate the processes that give rise to LIDs. These attempts include novel deposition processes and the reduction of impurities. Material improvements achieved over the past decade are associated more with the material`s microstructure than with eliminating LIDs. We conclude that metastable LIDs are a natural by-product of structural changes which are generally associated with non-radiative electron-hole recombination in amorphous semiconductors.

  18. Uncertainty in Estimation of Bioenergy Induced Lulc Change: Development of a New Change Detection Technique.

    Science.gov (United States)

    Singh, N.; Vatsavai, R. R.; Patlolla, D.; Bhaduri, B. L.; Lim, S. J.

    2015-12-01

    Recent estimates of bioenergy induced land use land cover change (LULCC) have large uncertainty due to misclassification errors in the LULC datasets used for analysis. These uncertainties are further compounded when data is modified by merging classes, aggregating pixels and change in classification methods over time. Hence the LULCC computed using these derived datasets is more a reflection of change in classification methods, change in input data and data manipulation rather than reflecting actual changes ion ground. Furthermore results are constrained by geographic extent, update frequency and resolution of the dataset. To overcome this limitation we have developed a change detection system to identify yearly as well as seasonal changes in LULC patterns. Our method uses hierarchical clustering which works by grouping objects into a hierarchy based on phenological similarity of different vegetation types. The algorithm explicitly models vegetation phenology to reduce spurious changes. We apply our technique on globally available Moderate Resolution Imaging Spectroradiometer (MODIS) NDVI data at 250-meter resolution. We analyze 10 years of bi-weekly data to predict changes in the mid-western US as a case study. The results of our analysis are presented and its advantages over existing techniques are discussed.

  19. Investigations into the free-volume changes within starch/plasticizer/nanoclay systems using Positron Annihilation Lifetime Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Huihua, E-mail: h.liu@federation.edu.au [School of Health Sciences, Federation University Australia, Ballarat, Vic (Australia); Chaudhary, Deeptangshu, E-mail: deepc@ers.com.au [ERS Environmental Risk Solutions PTY LTD, Perth, WA (Australia); Campbell, Colin, E-mail: colin.campbell@anu.edu.au [ARC Centre of Excellence for Antimatter-Matter Studies (CAMS), Research School of Physics and Engineering, Australian National University, Canberra (Australia); Roberts, Jason, E-mail: jxr107@physics.anu.edu.au [ARC Centre of Excellence for Antimatter-Matter Studies (CAMS), Research School of Physics and Engineering, Australian National University, Canberra (Australia); Buckman, Stephen, E-mail: stephen.buckman@anu.edu.au [ARC Centre of Excellence for Antimatter-Matter Studies (CAMS), Research School of Physics and Engineering, Australian National University, Canberra (Australia); Sullivan, James, E-mail: james.sullivan@anu.edu.au [ARC Centre of Excellence for Antimatter-Matter Studies (CAMS), Research School of Physics and Engineering, Australian National University, Canberra (Australia)

    2014-11-14

    The free-volume of a matrix is a fundamental parameter that relates to its molecular and bulk characteristics, such as crystalline change and glass transition behavior. In starch-based bionanocomposite, we investigated the effect of the addition of montmorillonite nanoclay (MMT) and food plasticizers (glycerol and sorbitol) on changes of molecular pore size (including pore volume and pore distribution) using the Positron Annihilation Lifetime Spectroscopy (PALS) method. The results demonstrated counter-intuitive impact of MMT on the total free-volume where the total free-volume increased within the polymeric matrix. When compared to the pure matrix free-volume, the addition of MMT also resulted in the appearance of a broader distribution of the void sizes. The plasticizers, on the other hand, apparently occupied the void spaces, and therefore decreased the free-volume of the matrix. Further, together with the small angle X-ray scattering (SAXS) analysis, we concluded that this is a result of interplay between the plasticizer-plasticizer interactions and the polymer–plasticizer interactions. For example, in the starch/glycerol/MMT system, the pore radii slightly decrease upon the increasing of glycerol amount (OG210 = O.27 nm and OG220 = 0.26 nm), but the relative weight did increase with the increasing glycerol concentration. However, increasing the sorbitol amount increased the pore size from 0.23 nm(OS210) to 0.28 nm(OS220). Furthermore, the addition MMT in the OS010 system, promote the emergence of a new dateable pore radius(0.90 nm), and the total weight significantly increased from 13.70 (OS010) to 19.5% (OS210). We suggest that the pore variation (size and distribution) due to the MMT and plasticizers are reflected in the polymer glass transition and crystallinity because ultimately, the, total free-volume is a reflection of level of interactions existing within the bulk of these nanocomposites. - Highlights: • PALS is applied to explore the

  20. Reverse asymmetry and changes in brain structural volume of the basal ganglia in ADHD, developmental changes and the impact of stimulant medications.

    Science.gov (United States)

    Paclt, Ivo; Pribilová, Nikol; Kollárová, Patricie; Kohoutová, Milada; Dezortová, Monika; Hájek, Milan; Csemy, Ladislav

    2016-01-01

    We discussed the cross section studies and the meta-analysis of published data in children and adolescents with ADHD (both drug naive and receiving stimulant medications), in comparison with healthy children and adolescents of the same age. In children and adolescents with ADHD the deceleration of the maturation dynamics of discrete CNS structures is found, volume reduction and decreased grey matter in prefrontal and occipital regions, which is accompanied by reverse asymmetry of the basal ganglia volume (putamen, nucleus caudate). The above mentioned developmental characteristics are valid only for the ADHD children, who have not been treated by stimulant medications. The stimulant treatment eliminates the mentioned changes into various extend. These developmental changes of CNS structures volume are missing in girls.

  1. CO2 laser induced refractive index changes in optical polymers.

    Science.gov (United States)

    Liu, Qing; Chiang, Kin Seng; Reekie, Laurence; Chow, Yuk Tak

    2012-01-01

    We study the infrared photosensitivity properties of two optical polymer materials, benzocyclobutene (BCB) and epoxy OPTOCAST 3505, with a 10.6 μm CO2 laser. We discover that the CO2 laser radiation can lower the refractive index of BCB by as much as 5.5 × 10(-3), while inducing no measurable index change in the epoxy. As confirmed by Fourier transform infrared spectroscopy, the observed index change in BCB can be attributed to photothermal modification of chemical bonds in the material by the CO2 laser radiation. Our findings open up a new possibility of processing polymer materials with a CO2 laser, which could be further developed for application in the areas of post-processing and direct-writing of polymer waveguide devices.

  2. Pseudoxanthoma-elasticum-like skin changes induced by penicillamine.

    Science.gov (United States)

    Bolognia, J L; Braverman, I

    1992-01-01

    The interference of penicillamine with collagen and elastin cross-linking can lead to wrinkling and anetoderma-like lesions in flexural areas as well as fragility and hemorrhagic blisters in pressure areas. These changes are seen primarily in patients with Wilson's disease or cystinuria who are on long-term therapy. This is a report of a patient with cystinuria on long-term, high-dose penicillamine who developed pseudoxanthoma-elasticum-like lesions. Coalescent yellow papules with a 'plucked-chicken skin' appearance were seen in the axillae and on the neck while redundant skin folds were noted in the anterior axillary line and lower buttocks. By light and electron microscopy, involved and uninvolved skin demonstrated 'lumpy-bumpy' dermal elastic fibers with no calcium deposition. These histologic changes are similar to those previously described in patients with penicillamine-induced skin lesions.

  3. The role of cytokines in immune changes induced by spaceflight

    Science.gov (United States)

    Sonnenfeld, G.; Miller, E. S.

    1993-01-01

    It has become apparent that spaceflight alters many immune responses. Among the regulatory components of the immune response that have been shown to be affected by spaceflight is the cytokine network. Spaceflight, as well as model systems of spaceflight, have been shown to affect the production and action of various cytokines including interferons, interleukins, colony stimulating factors, and tumor necrosis factors. These changes have been shown not to involve a general shutdown of the cytokine network but, rather, to involve selective alterations of specific cytokine functions by spaceflight. The full breadth of changes in cytokines induced by spaceflight, as well as mechanisms, duration, adaptation, reversibility, and significance to resistance to infection and neoplastic diseases, remains to be established.

  4. Age dependent white matter lesions and brain volume changes in healthy volunteers

    DEFF Research Database (Denmark)

    Christiansen, P; Larsson, H B; Thomsen, C

    1994-01-01

    The brain of 142 healthy volunteers aged 21 to 80 years were investigated using MR imaging. The number and size of the white matter hyperintensity lesions (WMHL) in the cerebral hemispheres were determined. Furthermore, the volume of the cerebral hemispheres and of the lateral ventricles...... was measured. An almost linear increase in the number of volunteers with WMHL was seen with aging for males and females. With aging a significant decrease in the volume of the cerebral hemispheres was found for males, and a significant increase in the volume of the lateral ventricles was seen for both males...... and females. Our results suggest that with aging central atrophy increases more (relatively) than cortical atrophy. No correlation was found between the decreasing volume of the cerebral hemispheres and the increasing number and size of WMHL, nor between the increasing volume of the lateral ventricles...

  5. Stress-induced core temperature changes in pigeons (Columba livia).

    Science.gov (United States)

    Bittencourt, Myla de Aguiar; Melleu, Fernando Falkenburger; Marino-Neto, José

    2015-02-01

    Changes in body temperature are significant physiological consequences of stressful stimuli in mammals and birds. Pigeons (Columba livia) prosper in (potentially) stressful urban environments and are common subjects in neurobehavioral studies; however, the thermal responses to stress stimuli by pigeons are poorly known. Here, we describe acute changes in the telemetrically recorded celomatic (core) temperature (Tc) in pigeons given a variety of potentially stressful stimuli, including transfer to a novel cage (ExC) leading to visual isolation from conspecifics, the presence of the experimenter (ExpR), gentle handling (H), sham intracelomatic injections (SI), and the induction of the tonic immobility (TI) response. Transfer to the ExC cage provoked short-lived hyperthermia (10-20 min) followed by a long-lasting and substantial decrease in Tc, which returned to baseline levels 2 h after the start of the test. After a 2-hour stay in the ExC, the other potentially stressful stimuli evoked only weak, marginally significant hyperthermic (ExpR, IT) or hypothermic (SI) responses. Stimuli delivered 26 h after transfer to the ExC induced definite and intense increases in Tc (ExpR, H) or hypothermic responses (SI). These Tc changes appear to be unrelated to modifications in general activity (as measured via telemetrically recorded actimetric data). Repeated testing failed to affect the hypothermic responses to the transference to the ExC, even after nine trials and at 1- or 8-day intervals, suggesting that the social (visual) isolation from conspecifics may be a strong and poorly controllable stimulus in this species. The present data indicated that stress-induced changes in Tc may be a consistent and reliable physiological parameter of stress but that they may also show stressor type-, direction- and species-specific attributes.

  6. Change Matters: Critical Essays on Moving Social Justice Research from Theory to Policy. Critical Qualitative Research. Volume 1

    Science.gov (United States)

    Miller, S. J., Ed.; Kirkland, David E., Ed.

    2010-01-01

    "Change Matters," written by leading scholars committed to social justice in English education, provides researchers, university instructors, and preservice and inservice teachers with a framework that pivots social justice toward policy. The chapters in this volume detail rationales about generating social justice theory in what Freire calls "the…

  7. Assessment and forecast of changes of reservoir volumes due to thermal settling in permafrost areas of Russia

    Institute of Scientific and Technical Information of China (English)

    Ilja S.Sobol; Stanislav V.Sobol

    2014-01-01

    This paper presents the results of data analyses and assessments of field and theoretical researches on reservoir bed relief transformation due to thermal settling in the permafrost regions of Russia. The resulting changes (increases) of the total volumes of large and small reservoirs are quantified, of which information will be of great use in future reservoir design and exploitation.

  8. Dexamethasone induced ultrastructural changes in cultured human trabecular meshwork cells.

    Science.gov (United States)

    Wilson, K; McCartney, M D; Miggans, S T; Clark, A F

    1993-09-01

    Glucocorticoid-induced ocular hypertension has been demonstrated in both animals and humans. It is possible that glucocorticoid-induced changes in trabecular meshwork (TM) cells are responsible for this hypertension. In order to elaborate further the effect of glucocorticoids on the trabecular meshwork, the ultrastructural consequences of dexamethasone (DEX) treatment were examined in three different human TM cell lines. Confluent TM cells were treated with 0.1 microM of DEX for 14 days, and then processed for light, epifluorescent microscopy or transmission electron microscopy (TEM). The effect of DEX treatment on TM cell and nuclear size was quantified using computer assisted morphometrics. Morphometric analysis showed a significant increase in both TM cell and nuclear size after 14 days of DEX treatment. Epifluorescent microscopy of rhodamine-phalloidin stained, control TM cells showed the normal arrangement of stress fibers. In contrast, DEX-treated TM cells showed unusual geodesic dome-like cross-linked actin networks. Control TM cells had the normal complement and arrangement of organelles as well as electron dense inclusions and large vacuoles. DEX-treated TM cells showed stacked arrangements of smooth and rough endoplasmic reticulum, proliferation of the Golgi apparatus, pleomorphic nuclei and increased amounts of extracellular matrix material. The DEX-induced alterations observed in the present study may be an indication of the processes that are occurring in the in vivo disease process.

  9. Evaluation of excavation-induced changes in rock permeability

    Energy Technology Data Exchange (ETDEWEB)

    Kelsall, P.C.; Case, J.B.; Chabannes, C.R.

    1984-06-01

    The nature of the changes in permeability around an underground opening induced by blast-damage or stress-relief is an important factor in the design of nuclear waste repositories in rocks such as granite or basalt. Changes in stress and corresponding changes in rock mass hydraulic conductivity are analyzed for a circular shaft using simplifying assumptions regarding fracture geometry and initial stress state. Stress distributions around the shaft are calculated using closed-form solutions and are related to changes in hydraulic conductivity using a form of the cubic law for flow through fractured media. The analysis predicts that hydraulic conductivity may be increased, close to the wall of the opening, by two to three orders of magnitude over the far-field value solely in response to stress relief. The zone in which hydraulic conductivity is increased by at least one order of magnitude over the far-field value is limited to within one to two radii from the opening. Blasting may result in large increases in hydraulic conductivity immediately adjacent to an opening but blast damage may be limited to within 0.3 m of the opening using controlled blasting techniques with low perimeter charge weights. 44 references.

  10. Aging induced changes on NEXAFS fingerprints in individual combustion particles

    Directory of Open Access Journals (Sweden)

    V. Zelenay

    2011-11-01

    particles could be detected. Because such small amounts of water uptake do not lead to measurable changes in particle diameter, it may remain beyond the limits of volume growth measurements, especially for larger agglomerated particles.

  11. Insecticides induced biochemical changes in freshwater microalga Chlamydomonas mexicana.

    Science.gov (United States)

    Kumar, Muthukannan Satheesh; Kabra, Akhil N; Min, Booki; El-Dalatony, Marwa M; Xiong, Jiuqiang; Thajuddin, Nooruddin; Lee, Dae Sung; Jeon, Byong-Hun

    2016-01-01

    The effect of insecticides (acephate and imidacloprid) on a freshwater microalga Chlamydomonas mexicana was investigated with respect to photosynthetic pigments, carbohydrate and protein contents, fatty acids composition and induction of stress indicators including proline, superoxide dismutase (SOD) and catalase (CAT). C. mexicana was cultivated with 1, 5, 10, 15, 20 and 25 mg L(-1) of acephate and imidacloprid. The microalga growth increased with increasing concentrations of both insecticides up to 15 mg L(-1), beyond which the growth declined compared to control condition (without insecticides). C. mexicana cultivated with 15 mg L(-1) of both insecticides for 12 days was used for further analysis. The accumulation of photosynthetic pigments (chlorophyll and carotenoids), carbohydrates and protein was decreased in the presence of both insecticides. Acephate and imidacloprid induced the activities of superoxide dismutase (SOD) and catalase (CAT) and increased the concentration of proline in the microalga, which play a defensive role against various environmental stresses. Fatty acid analysis revealed that the fraction of polyunsaturated fatty acids decreased on exposure to both insecticides. C. mexicana also promoted 25 and 21% removal of acephate and imidacloprid, respectively. The biochemical changes in C. mexicana on exposure to acephate and imidacloprid indicate that the microalga undergoes an adaptive change in response to the insecticide-induced oxidative stress.

  12. Heavy-ion induced genetic changes and evolution processes

    Science.gov (United States)

    Yang, C. H.; Craise, L. M.; Durante, M.; Mei, M.

    1994-01-01

    On Moon and Mars, there will be more galactic cosmic rays and higher radiation doses than on Earth. Our experimental studies showed that heavy ion radiation can effectively cause mutation and chromosome aberrations and that high Linear Energy Transfer (LET) heavy-ion induced mutants can be irreversible. Chromosome translocations and deletions are common in cells irradiated by heavy particles, and ionizing radiations are effective in causing hyperploidy. The importance of the genetic changes in the evolution of life is an interesting question. Through evolution, there is an increase of DNA content in cells from lower forms of life to higher organisms. The DNA content, however, reached a plateau in vertebrates. By increasing DNA content, there can be an increase of information in the cell. For a given DNA content, the quality of information can be changed by rearranging the DNA. Because radiation can cause hyperploidy, an increase of DNA content in cells, and can induce DNA rearrangement, it is likely that the evolution of life on Mars will be effected by its radiation environment. A simple analysis shows that the radiation level on Mars may cause a mutation frequency comparable to that of the spontaneous mutation rate on Earth. To the extent that mutation plays a role in adaptation, radiation alone on Mars may thus provide sufficient mutation for the evolution of life.

  13. Longitudinal volume changes of the pituitary gland in patients with schizotypal disorder and first-episode schizophrenia.

    Science.gov (United States)

    Takahashi, Tsutomu; Zhou, Shi-Yu; Nakamura, Kazue; Tanino, Ryoichiro; Furuichi, Atsushi; Kido, Mikio; Kawasaki, Yasuhiro; Noguchi, Kyo; Seto, Hikaru; Kurachi, Masayoshi; Suzuki, Michio

    2011-01-15

    An enlarged volume of the pituitary gland has been reported in the schizophrenia spectrum, possibly reflecting the hypothalamic-pituitary-adrenal (HPA) hyperactivity. However, it remains largely unknown whether the pituitary size longitudinally changes in the course of the spectrum disorders. In the present study, longitudinal magnetic resonance imaging (MRI) data were obtained from 18 patients with first-episode schizophrenia, 13 patients with schizotypal disorder, and 20 healthy controls. The pituitary volume was measured at baseline and follow-up (mean, 2.7 years) scans and was compared across groups. The pituitary volume was larger in the schizophrenia patients than controls at baseline, and both patient groups had significantly larger pituitary volume than controls at follow-up. In a longitudinal comparison, both schizophrenia (3.6%/year) and schizotypal (2.7%/year) patients showed significant pituitary enlargement compared with controls (-1.8%/year). In the schizophrenia patients, greater pituitary enlargement over time was associated with less improvement of delusions and higher scores for thought disorders at the follow-up. These findings suggest that the pituitary gland exhibits ongoing volume changes during the early course of the schizophrenia spectrum as a possible marker of state-related impairments. Copyright © 2010 Elsevier Inc. All rights reserved.

  14. Digital surgical templates for managing high-energy zygomaticomaxillary complex injuries associated with orbital volume change: a quantitative assessment.

    Science.gov (United States)

    Liu, Xiang-Zhen; Shu, Da-Long; Ran, Wei; Guo, Bing; Liao, Xin

    2013-10-01

    This study sought to introduce 3-dimensional (3D) virtual surgical planning and digital rapid-prototyping templates for zygomaticomaxillary complex (ZMC) injuries associated with orbital volume change and to evaluate the surgical outcomes quantitatively. Eight patients who underwent open reduction and fixation for a ZMC injury with orbital volume change were studied. Computed tomographic (CT) scan of the zygomaticomaxillary area was performed before the operation in each case. Scanned data were converted into 3D models using Mimics software (Materialise, Brussels, Belgium) for surgical designs. Virtual surgical reductions and correlated guiding templates were designed using Mimics and Magics software (Materialise). The operations were performed with the help of prefabricated templates to reduce the fractures. A postoperative CT scan of each patient was obtained within 2 weeks after surgery, and quantitative measurements were made to assess the surgical outcomes. Preoperative volumes of the bilateral orbits were compared, and concordance with postoperative volumes of the bilateral orbits was assessed. Twenty-one pairs of distances from 7 marker points to 3 reference planes were measured to assess postoperative facial symmetry. Volumes of the injured orbits were significantly different from volumes of the uninjured orbits preoperatively (P .05). In addition, 19 of the 21 pairs of bilateral distances showed no significant difference postoperatively (P > .05). Quantitative assessment showed that digitally designed, rapid-prototyping templates for ZMC fractures have a positive impact on restoring facial symmetry and concordance of bilateral orbital volumes. Copyright © 2013 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  15. Abiotic soil changes induced by engineered nanomaterials: A critical review.

    Science.gov (United States)

    Dror, Ishai; Yaron, Bruno; Berkowitz, Brian

    2015-10-01

    A large number of research papers on the fate of engineered nanomaterials (ENMs) in the soil-water system have appeared in recent years, focusing on ENM transport, persistence and toxicological impact. It is clear from these publications that soil is a major sink for ENMs, and that only a small portion degrades or is mobilized further into groundwater. However, to date, very few studies have examined the impact of ENMs on the natural soil-subsurface matrix and its properties. Moreover, it is now well accepted that chemical contaminants are capable of changing soil properties either by inducing direct chemical or physical changes, or through indirect changes by, e.g., influencing biological activity that in turn modifies soil properties. Here, we review studies on the deposition, retention, and accumulation of ENMs in soil, indicative of the extent to which soil acts as a major sink of ENMs. We then examine evidence of how these retained particles lead to modification of surface properties, which are manifested by changes in the sorption capacity of soil for other (organic and inorganic) solutes, and by surface charges and composition different than the natural surfaces. Finally, we demonstrate how this results in physical and hydrological changes to soil properties, including hydraulic conductivity, swelling capacity and wettability. The overall picture revealed in this critical review sheds light on a perspective that has received little attention thus far. These aspects of soil change, due to exposure and subsequent accumulation of ENMs, may ultimately prove to be one of the most important impacts of ENM releases to the environment.

  16. FUNDUS CHANGES IN PREGNANCY INDUCED HYPERTENSION: A CLINICAL STUDY

    Directory of Open Access Journals (Sweden)

    Rama Bharathi

    2015-01-01

    Full Text Available PURPOSE: To estimate the prevalence of fundus changes in Pregnancy Induced Hypertension (PIH and to find the correlation of the findings with the levels of hypertension and with the severity of the disease. METHODS: This was a hospital based cross section al study conducted over a period of one year from July 2012 to June 2013. 150 patients with diagnosed PIH and admission into wards at King George Hospital, Visakhapatnam, with 36 weeks period of gestation and above, were included in the study. Those with p re - existing hypertension, coexisting diabetes mellitus, severe anaemia, renal disease and ocular diseases like cataract or corneal opacities were excluded from the study. After taking consent and ocular history, anterior segment was evaluated. Pupils were dilated with 0.5% tropicamide eye drops and fundus examination was done with direct ophthalmoscope. Information like age, para, BP etc., was noted down from case sheets. RESULTS: Total number of patients studied was 150.Mean age was 23.06+ 3.03years. 105 ( 70% were primigravidae and 45(30% were multigravidae. Fundus findings were seen in 35 cases (23.33%. 26 (17.33% had Grade I changes, 1 (0.66% had grade II changes, 6 (3.9% had grade III changes 2 (1.3% had serous retinal detachment/grade - IV. The de gree of retinopathy was correlating with the severity of the disease and levels of hypertension. CONCLUSION: The prevalence of fundus changes in PIH is 23.33%. Most of the fundus changes in PIH are underdiagnosed. Timely ophthalmoscopy should be called for in all cases of PIH as it would affect the decision of induction of delivery, thereby preventing other complications.

  17. Radiation-induced morphological changes in the vagina

    Energy Technology Data Exchange (ETDEWEB)

    Kirchheiner, K.; Fidarova, E.; Schmid, M.P.; Sturdza, A.; Kranz, A.; Poetter, R. [Medical Univ. of Vienna (Austria). Dept. of Radiation Oncology; Nout, R.A. [University Medical Center Leiden (Netherlands). Dept. of Clinical Oncology; Wiebe, E. [Alberta Univ., Cross Cancer Institute, Edmonton, AB (Canada). Dept. of Radiation Oncology; Polterauer, S. [Medical Univ. of Vienna (Austria). Dept. of General Gynecology and Gynecologic Oncology; Doerr, W. [Medical Univ. of Vienna (Austria). Dept. of Radiation Oncology; Medical Univ. of Vienna (Austria). Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology

    2012-11-15

    Background and purpose: Treatment-induced chronic vaginal changes after definitive radio(chemo)therapy for locally advanced cervical cancer patients are reported as one of the most distressing consequences of treatment, with major impact on quality of life. Although these vaginal changes are regularly documented during gynecological follow-up examinations, the classic radiation morbidity grading scales are not concise in their reporting. The aim of the study was therefore to identify and qualitatively describe, on the basis of vaginoscopies, morphological changes in the vagina after definitive radio(chemo)therapy and to establish a classification system for their detailed and reproducible documentation. Patients and methods: Vaginoscopy with photodocumentation was performed prospectively in 22 patients with locally advanced cervical cancer after definitive radio(chemo)therapy at 3-24 months after end of treatment. All patients were in complete remission and without severe grade 3/4 morbidity outside the vagina. Results: Five morphological parameters, which occurred consistently after treatment, were identified: mucosal pallor, telangiectasia, fragility of the vaginal wall, ulceration, and adhesions/occlusion. The symptoms in general were observed at different time points in individual patients; their quality was independent of the time of assessment. Based on the morphological findings, a comprehensive descriptive and semiquantitative scoring system was developed, which allows for classification of vaginal changes. A photographic atlas to illustrate the morphology of the alterations is presented. Conclusion: Vaginoscopy is an easily applicable, informative, and well-tolerated procedure for the objective assessment of morphological vaginal changes after radio(chemo)therapy and provides comprehensive and detailed information. This allows for precise classification of the severity of individual changes. (orig.)

  18. Curcumin and sertraline prevent the reduction of the number of neurons and glial cells and the volume of rats' medial prefrontal cortex induced by stress.

    Science.gov (United States)

    Noorafshan, Ali; Abdollahifar, Mohammad-Amin; Asadi-Golshan, Reza; Rashidian-Rashidabadi, Ali; Karbalay-Doust, Saied

    2014-01-01

    Chronic stress induces morphological changes in the neurons of several brain regions, including medial prefrontal cortex (mPFC). This region is involved in variety of behavioral tasks, including learning and memory. Our previous work showed that stress impaired function. The present work extends the earlier work to study mPFC in stressed and non-stressed rats with or without sertraline or curcumin treatments using stereological methods. Sertraline is a selective serotonin reuptake inhibitor and curcumin is the main ingredient of turmeric with neuroprotective effects. In this study, 42 male rats were randomly assigned to seven groups: stress + distilled water, stress + olive oil, stress + curcumin (100 mg/kg/day), stress + sertraline (10 mg/kg/day), curcumin, sertraline, and control groups. After 56 days, the right mPFC was removed. The volume of mPFC and its subdivisions and the total number of neurons and glia were estimated. The results showed ~8%, ~8%, and 24% decrease in the volume of the mPFC and its prelimbic and infralimbic subdivisions, respectively. However, the anterior cingulated cortex remained unchanged. Also, the total number of the neurons and glial cells was significantly reduced (11% and 5%, respectively) in stress (+distilled water or olive oil) group in comparison to the non-stressed rats (Psertraline and stress + curcumin groups in comparison to the non-treated stressed rats (Psertraline could prevent the stress-induced changes in mPFC.

  19. Serotoninergic Modulation of Basal Cardiovascular Responses and Responses Induced by Isotonic Extracellular Volume Expansion in Rats

    Directory of Open Access Journals (Sweden)

    Isadora Ferraz Semionatto

    Full Text Available Abstract Background: Isotonic blood volume expansion (BVE induced alterations of sympathetic and parasympathetic activity in the heart and blood vessels, which can be modulated by serotonergic pathways. Objective: To evaluate the effect of saline or serotonergic agonist (DOI administration in the hypothalamic paraventricular nucleus (PVN on cardiovascular responses after BVE. Methods: We recorded pulsatile blood pressure through the femoral artery to obtain the mean arterial pressure (MAP, systolic (SBP and diastolic blood pressure (DBP, heart rate (HR and the sympathetic-vagal ratio (LF/HF of Wistar rats before and after they received bilateral microinjections of saline or DOI into the PVN, followed by BVE. Results: No significant differences were observed in the values of the studied variables in the different treatments from the control group. However, when animals are treated with DOI followed by BVE there is a significant increase in relation to the BE control group in all the studied variables: MBP (114.42±7.85 vs 101.34±9.17; SBP (147.23±14.31 vs 129.39±10.70; DBP (98.01 ±4.91 vs 87.31±8.61; HR (421.02±43.32 vs 356.35±41.99; and LF/HF ratio (2.32±0.80 vs 0.27±0.32. Discussion: The present study showed that the induction of isotonic BVE did not promote alterations in MAP, HR and LF/HF ratio. On the other hand, the injection of DOI into PVN of the hypothalamus followed by isotonic BVE resulted in a significant increase of all variables. Conclusion: These results suggest that serotonin induced a neuromodulation in the PVN level, which promotes an inhibition of the baroreflex response to BVE. Therefore, the present study suggests the involvement of the serotonergic system in the modulation of vagal reflex response at PVN in the normotensive rats.

  20. A pomegranate-inspired nanoscale design for large-volume-change lithium battery anodes

    Science.gov (United States)

    Liu, Nian; Lu, Zhenda; Zhao, Jie; McDowell, Matthew T.; Lee, Hyun-Wook; Zhao, Wenting; Cui, Yi

    2014-03-01

    Silicon is an attractive material for anodes in energy storage devices, because it has ten times the theoretical capacity of its state-of-the-art carbonaceous counterpart. Silicon anodes can be used both in traditional lithium-ion batteries and in more recent Li-O2 and Li-S batteries as a replacement for the dendrite-forming lithium metal anodes. The main challenges associated with silicon anodes are structural degradation and instability of the solid-electrolyte interphase caused by the large volume change (~300%) during cycling, the occurrence of side reactions with the electrolyte, and the low volumetric capacity when the material size is reduced to a nanometre scale. Here, we propose a hierarchical structured silicon anode that tackles all three of these problems. Our design is inspired by the structure of a pomegranate, where single silicon nanoparticles are encapsulated by a conductive carbon layer that leaves enough room for expansion and contraction following lithiation and delithiation. An ensemble of these hybrid nanoparticles is then encapsulated by a thicker carbon layer in micrometre-size pouches to act as an electrolyte barrier. As a result of this hierarchical arrangement, the solid-electrolyte interphase remains stable and spatially confined, resulting in superior cyclability (97% capacity retention after 1,000 cycles). In addition, the microstructures lower the electrode-electrolyte contact area, resulting in high Coulombic efficiency (99.87%) and volumetric capacity (1,270 mAh cm-3), and the cycling remains stable even when the areal capacity is increased to the level of commercial lithium-ion batteries (3.7 mAh cm-2).

  1. Thermal Volume Changes and Creep in the Callovo-Oxfordian Claystone

    Science.gov (United States)

    Belmokhtar, Malik; Delage, Pierre; Ghabezloo, Siavash; Conil, Nathalie

    2017-09-01

    The Callovo-Oxfordian (COx) claystone is considered as a potential host rock for high-level radioactive waste disposal at great depth in France. Given the exothermic nature of radioactive wastes, a temperature elevation planned to be smaller than 100 °C will affect the host rock around the disposal cells. To gain better understanding of the thermal volumetric response of the COx claystone, a new thermal isotropic compression cell was developed with particular attention devoted to monitoring axial and radial strains. To do so, a high-precision LVDTs system ensuring direct contact between the LVDT stem and the claystone sample through the membrane was developed. A short drainage length (10 mm) was also ensured so as to allow full saturation of the sample under stress conditions close to in situ, and fully drained conditions during compression. High-precision strain monitoring allowed to observe a volumetric creep under stress conditions close to in situ. A drained heating test under constant stress carried out afterwards up to 80 °C exhibited a thermoelastic expansion up to a temperature of 48 °C, followed by thermoplastic contraction at higher temperature. Creep volume changes, that appeared to be enhanced by temperature, were modelled by using a simple Kelvin-Voigt model, so as to estimate the instantaneous response of the COx claystone and to determine its thermal expansion coefficient. The temperature at which the transition between thermal expansion and contraction appeared is close to the maximum burial temperature of the Callovo-Oxfordian claystone, estimated at 50 °C. This is in agreement with what has been already observed on the Opalinus Clay by Monfared et al. (2012) that was interpreted as a thermal hardening phenomenon, showing that the material kept the memory of the highest temperature supported during its geological history.

  2. Assessment of bronchodilator response through changes in lung volumes in chronic airflow obstruction

    Directory of Open Access Journals (Sweden)

    J.B. Figueroa-Casas

    2003-10-01

    Full Text Available Although FEV1 improvement is routinely used to define bronchodilator (BD response, it correlates poorly with clinical effects. Changes in lung volumes (LV have shown better correlation with exercise tolerance and might be more sensitive to detect BD effects. We assessed the additional contribution of measuring LV before and after BD to detect acute improvement in lung function not demonstrated by FEV1, and the influence of the response criteria selected on this contribution. We analyzed 98 spirometries and plethismographies performed pre and post BD in patients with airflow obstruction (FEV1/FVC 10% of baseline (D>5 anD>15% were also analyzed. FEV1 identified as responders 32% of patients. Greater proportions were uncovered by slow vital capacity (51%, p5 anD>15%. Mean change and proportions of responders for each LV varied significantly (pSi bien el aumento del VEF1 es habitualmente utilizado para definir respuesta a broncodilatadores (BD, su correlación con efectos clínicos es pobre. Los cambios en volúmenes pulmonares (VP han demostrado mejor correlación con tolerancia al ejercicio y podrían ser más sensibles para detectar efectos de los BD. Nosotros evaluamos la contribución adicional de medir VP antes y después de BD para detectar mejoría funcional aguda no demostrada por cambios del VEF1, y la influencia del criterio de respuesta seleccionado en esta contribución. Se analizaron 98 espirometrías y pletismografías realizadas pre y post BD en pacientes con obstrucción al flujo aéreo (VEF1/CVF 10% del basal (D>5 y 15% fueron también analizados. El VEF1 identificó como respondedores a 32% de los pacientes. Proporciones mayores fueron identificadas por capacidad vital lenta (51%, p5 y 15%. El cambio promedio y las proporciones de respondedores para cada VP variaron significativamente (p<0.05 según que el cambio fuese expresado como porcentaje del basal o del valor predicho. Una proporción considerable de pacientes con obstrucci

  3. Non-verbal emotion communication training induces specific changes in brain function and structure

    Science.gov (United States)

    Kreifelts, Benjamin; Jacob, Heike; Brück, Carolin; Erb, Michael; Ethofer, Thomas; Wildgruber, Dirk

    2013-01-01

    The perception of emotional cues from voice and face is essential for social interaction. However, this process is altered in various psychiatric conditions along with impaired social functioning. Emotion communication trainings have been demonstrated to improve social interaction in healthy individuals and to reduce emotional communication deficits in psychiatric patients. Here, we investigated the impact of a non-verbal emotion communication training (NECT) on cerebral activation and brain structure in a controlled and combined functional magnetic resonance imaging (fMRI) and voxel-based morphometry study. NECT-specific reductions in brain activity occurred in a distributed set of brain regions including face and voice processing regions as well as emotion processing- and motor-related regions presumably reflecting training-induced familiarization with the evaluation of face/voice stimuli. Training-induced changes in non-verbal emotion sensitivity at the behavioral level and the respective cerebral activation patterns were correlated in the face-selective cortical areas in the posterior superior temporal sulcus and fusiform gyrus for valence ratings and in the temporal pole, lateral prefrontal cortex and midbrain/thalamus for the response times. A NECT-induced increase in gray matter (GM) volume was observed in the fusiform face area. Thus, NECT induces both functional and structural plasticity in the face processing system as well as functional plasticity in the emotion perception and evaluation system. We propose that functional alterations are presumably related to changes in sensory tuning in the decoding of emotional expressions. Taken together, these findings highlight that the present experimental design may serve as a valuable tool to investigate the altered behavioral and neuronal processing of emotional cues in psychiatric disorders as well as the impact of therapeutic interventions on brain function and structure. PMID:24146641

  4. Non-verbal emotion communication training induces specific changes in brain function and structure.

    Science.gov (United States)

    Kreifelts, Benjamin; Jacob, Heike; Brück, Carolin; Erb, Michael; Ethofer, Thomas; Wildgruber, Dirk

    2013-01-01

    The perception of emotional cues from voice and face is essential for social interaction. However, this process is altered in various psychiatric conditions along with impaired social functioning. Emotion communication trainings have been demonstrated to improve social interaction in healthy individuals and to reduce emotional communication deficits in psychiatric patients. Here, we investigated the impact of a non-verbal emotion communication training (NECT) on cerebral activation and brain structure in a controlled and combined functional magnetic resonance imaging (fMRI) and voxel-based morphometry study. NECT-specific reductions in brain activity occurred in a distributed set of brain regions including face and voice processing regions as well as emotion processing- and motor-related regions presumably reflecting training-induced familiarization with the evaluation of face/voice stimuli. Training-induced changes in non-verbal emotion sensitivity at the behavioral level and the respective cerebral activation patterns were correlated in the face-selective cortical areas in the posterior superior temporal sulcus and fusiform gyrus for valence ratings and in the temporal pole, lateral prefrontal cortex and midbrain/thalamus for the response times. A NECT-induced increase in gray matter (GM) volume was observed in the fusiform face area. Thus, NECT induces both functional and structural plasticity in the face processing system as well as functional plasticity in the emotion perception and evaluation system. We propose that functional alterations are presumably related to changes in sensory tuning in the decoding of emotional expressions. Taken together, these findings highlight that the present experimental design may serve as a valuable tool to investigate the altered behavioral and neuronal processing of emotional cues in psychiatric disorders as well as the impact of therapeutic interventions on brain function and structure.

  5. Evaluation of postoperative change in lung volume in adolescent idiopathic scoliosis: Measured by computed tomography

    Directory of Open Access Journals (Sweden)

    Dong Kyu Lee

    2014-01-01

    Conclusion: Patients with AIS who have preoperative reduced lung volumes or lung functions can achieve further increased lung volume after surgical correction. Pulmonary complications during perioperative period were mostly treated with proper management without severe sequale. Therefore, although surgery for AIS is considered to be a high risk procedure, we can recommend to correct spine deformity in patients with severe AIS in order to improve lung function and long term prognosis.

  6. Repetition priming-induced changes in sensorimotor transmission.

    Science.gov (United States)

    Svensson, Erik; Evans, Colin G; Cropper, Elizabeth C

    2016-03-01

    When a behavior is repeated performance often improves, i.e., repetition priming occurs. Although repetition priming is ubiquitous, mediating mechanisms are poorly understood. We address this issue in the feeding network ofAplysia Similar to the priming observed elsewhere, priming inAplysiais stimulus specific, i.e., it can be either "ingestive" or "egestive." Previous studies demonstrated that priming alters motor and premotor activity. Here we sought to determine whether sensorimotor transmission is also modified. We report that changes in sensorimotor transmission do occur. We ask how they are mediated and obtain data that strongly suggest a presynaptic mechanism that involves changes in the "background" intracellular Ca(2+)concentration ([Ca(2+)]i) in primary afferents themselves. This form of plasticity has previously been described and generated interest due to its potentially graded nature. Manipulations that alter the magnitude of the [Ca(2+)]iimpact the efficacy of synaptic transmission. It is, however, unclear how graded control is exerted under physiologically relevant conditions. In the feeding system changes in the background [Ca(2+)]iare mediated by the induction of a nifedipine-sensitive current. We demonstrate that the extent to which this current is induced is altered by peptides (i.e., increased by a peptide released during the repetition priming of ingestive activity and decreased by a peptide released during the repetition priming of egestive activity). We suggest that this constitutes a behaviorally relevant mechanism for the graded control of synaptic transmission via the regulation of the [Ca(2+)]iin a neuron.

  7. Bacoside A: Role in Cigarette Smoking Induced Changes in Brain.

    Science.gov (United States)

    Vani, G; Anbarasi, K; Shyamaladevi, C S

    2015-01-01

    Cigarette smoking (CS) is a major health hazard that exerts diverse physiologic and biochemical effects mediated by the components present and generated during smoking. Recent experimental studies have shown predisposition to several biological consequences from both active and passive cigarette smoke exposure. In particular, passive smoking is linked to a number of adverse health effects which are equally harmful as active smoking. A pragmatic approach should be considered for designing a pharmacological intervention to combat the adverse effects of passive smoking. This review describes the results from a controlled experimental condition, testing the effect of bacoside A (BA) on the causal role of passive/secondhand smoke exposure that caused pathological and neurological changes in rat brain. Chronic exposure to cigarette smoke induced significant changes in rat brain histologically and at the neurotransmitter level, lipid peroxidation states, mitochondrial functions, membrane alterations, and apoptotic damage in rat brain. Bacoside A is a neuroactive agent isolated from Bacopa monnieri. As a neuroactive agent, BA was effective in combating these changes. Future research should examine the effects of BA at molecular level and assess its functional effects on neurobiological and behavioral processes associated with passive smoke.

  8. Bacoside A: Role in Cigarette Smoking Induced Changes in Brain

    Directory of Open Access Journals (Sweden)

    G. Vani

    2015-01-01

    Full Text Available Cigarette smoking (CS is a major health hazard that exerts diverse physiologic and biochemical effects mediated by the components present and generated during smoking. Recent experimental studies have shown predisposition to several biological consequences from both active and passive cigarette smoke exposure. In particular, passive smoking is linked to a number of adverse health effects which are equally harmful as active smoking. A pragmatic approach should be considered for designing a pharmacological intervention to combat the adverse effects of passive smoking. This review describes the results from a controlled experimental condition, testing the effect of bacoside A (BA on the causal role of passive/secondhand smoke exposure that caused pathological and neurological changes in rat brain. Chronic exposure to cigarette smoke induced significant changes in rat brain histologically and at the neurotransmitter level, lipid peroxidation states, mitochondrial functions, membrane alterations, and apoptotic damage in rat brain. Bacoside A is a neuroactive agent isolated from Bacopa monnieri. As a neuroactive agent, BA was effective in combating these changes. Future research should examine the effects of BA at molecular level and assess its functional effects on neurobiological and behavioral processes associated with passive smoke.

  9. Emotion-Induced Topological Changes in Functional Brain Networks.

    Science.gov (United States)

    Park, Chang-Hyun; Lee, Hae-Kook; Kweon, Yong-Sil; Lee, Chung Tai; Kim, Ki-Tae; Kim, Young-Joo; Lee, Kyoung-Uk

    2016-01-01

    In facial expression perception, a distributed network is activated according to stimulus context. We proposed that an interaction between brain activation and stimulus context in response to facial expressions could signify a pattern of interactivity across the whole brain network beyond the face processing network. Functional magnetic resonance imaging data were acquired for 19 young healthy subjects who were exposed to either emotionally neutral or negative facial expressions. We constructed group-wise functional brain networks for 12 face processing areas [bilateral inferior occipital gyri (IOG), fusiform gyri (FG), superior temporal sulci (STS), amygdalae (AMG), inferior frontal gyri (IFG), and orbitofrontal cortices (OFC)] and for 73 whole brain areas, based on partial correlation of mean activation across subjects. We compared the topological properties of the networks with respect to functional distance-based measures, global and local efficiency, between the two types of face stimulus. In both face processing and whole brain networks, global efficiency was lower and local efficiency was higher for negative faces relative to neutral faces, indicating that network topology differed according to stimulus context. Particularly in the face processing network, emotion-induced changes in network topology were attributable to interactions between core (bilateral IOG, FG, and STS) and extended (bilateral AMG, IFG, and OFC) systems. These results suggest that changes in brain activation patterns in response to emotional face stimuli could be revealed as changes in the topological properties of functional brain networks for the whole brain as well as for face processing areas.

  10. Central administration of kisspeptin-10 inhibits natriuresis and diuresis induced by blood volume expansion in anesthetized male rats

    OpenAIRE

    Han, Xu; Yan, Ming; An, Xiao-fei; HE Ming; Yu, Jiang-Yi

    2009-01-01

    Aim: To investigate the possible role of hypothalamic kisspeptin in the regulation of body fluid metabolism and maintenance of internal homeostasis. Methods: Natriuresis and diuresis were induced by blood volume expansion (VE) in anesthetized male rats and kisspeptin-10 was intracerebroventricularly (icv) administered. Radioimmunoassay (RIA) was used to measure the plasma arginine vasopressin (AVP) and atrial natriuretic peptide (ANP) concentrations during the VE. The mediation of the renal s...

  11. Change in Tear Film Lipid Layer Thickness, Corneal Thickness, Volume and Topography after Superficial Cauterization for Conjunctivochalasis.

    Science.gov (United States)

    Chan, Tommy C Y; Ye, Cong; Ng, Paul K F; Li, Emmy Y M; Yuen, Hunter K L; Jhanji, Vishal

    2015-07-17

    We evaluated the change in tear film lipid layer thickness, corneal thickness, volume and topography after superficial cauterization of symptomatic conjunctivochalasis. Bilateral superficial conjunctival cauterization was performed in 36 eyes of 18 patients with symptomatic conjunctivochalasis. The mean age of patients (12 males, 6 females) was 68.6 ± 10.9 years (range: 44-83 years). Preoperatively, 28 eyes (77.8%) had grade 1 conjunctivochalasis, and 8 eyes (22.2%) had grade 2 conjunctivochalasis. At 1 month postoperatively, the severity of conjunctivochalasis decreased significantly (p corneal thickness, thinnest corneal thickness and corneal volume decreased significantly postoperatively (p corneal thickness and volume were observed after surgical correction of conjunctivochalasis.

  12. Clinical study on the changes of the tumor target volume and organs at risk in helical tomotherapy for nasopharyngeal carcinoma

    Institute of Scientific and Technical Information of China (English)

    LU Na; FENG Lin-chun; CAI Bo-ning; HOU Jun; WANG Yun-lai; XIE Chuan-bin

    2012-01-01

    Background Helical tomotherapy (HT) is a new image-guided intensity-modulated radiation therapy (IMRT).The aim of this study was to evaluate the changes in the target volume and organs at risk (OARs) of patients with nasopharyngeal carcinoma (NPC) during helical tomotherapy.Methods Forty-three patients with NPC and treated via HT from March 2008 to January 2010 were reviewed retrospectively.Repeated CT scanning and plan adaptation were conducted at the 20th fraction during radiotherapy.The volumetric differences between the two scans were evaluated for nasopharyngeal tumor and retro- pharyngeal lymph nodes (GTVnx),neck lymph nodes (GTVnd),and parotid glands,as well as the axial diameter of the head.Results The median interval between the two scans was 25 days (23-28 days).The volumetric decrease in GTVnx was 30.1% (median,29.8%) and in GTVnd 41.6% (median,45.9%).The variation in the GTVnd volume was correlated with the weight loss of the patient.The volume of the left parotid gland decreased by 35.5% (median,33.4%) and of the right parotid glands decreased by 36.8% (median,33.5%).The axial diameter of the head decreased by 9.39% (median,9.1%).Conclusions The target volume and OARs of patients with NPC varied considerably during HT.These changes may have potential dosimetric effects on the target volume and/or OARs and influence the clinical outcome.Repeated CT scanning and replanning during the HT for NPC patients with a large target volume or an obvious weight loss are recommended.

  13. Volume reductions in frontopolar and left perisylvian cortices in methamphetamine induced psychosis.

    Science.gov (United States)

    Aoki, Yuta; Orikabe, Lina; Takayanagi, Yoichiro; Yahata, Noriaki; Mozue, Yuriko; Sudo, Yasuhiko; Ishii, Tatsuji; Itokawa, Masanari; Suzuki, Michio; Kurachi, Masayoshi; Okazaki, Yuji; Kasai, Kiyoto; Yamasue, Hidenori

    2013-07-01

    Consumption of methamphetamine disturbs dopaminergic transmission and sometimes provokes schizophrenia-like-psychosis, named methamphetamine-associated psychosis (MAP). While previous studies have repeatedly reported regional volume reductions in the frontal and temporal areas as neuroanatomical substrates for psychotic symptoms, no study has examined whether such neuroanatomical substrates exist or not in patients with MAP. Magnetic resonance images obtained from twenty patients with MAP and 20 demographically-matched healthy controls (HC) were processed for voxel-based morphometry (VBM) using Diffeomorphic Anatomical Registration using Exponentiated Lie Algebra. An analysis of covariance model was adopted to identify volume differences between subjects with MAP and HC, treating intracranial volume as a confounding covariate. The VBM analyses showed significant gray matter volume reductions in the left perisylvian structures, such as the posterior inferior frontal gyrus and the anterior superior temporal gyrus, and the frontopolar cortices, including its dorsomedial, ventromedial, dorsolateral, and ventrolateral portions, and white matter volume reduction in the orbitofrontal area in the patients with MAP compared with the HC subjects. The smaller regional gray matter volume in the medial portion of the frontopolar cortex was significantly correlated with the severe positive symptoms in the individuals with MAP. The volume reductions in the left perisylvian structure suggest that patients with MAP have a similar pathophysiology to schizophrenia, whereas those in the frontopolar cortices and orbitofrontal area suggest an association with antisocial traits or vulnerability to substance dependence. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Sight of conspecific images induces changes in neurochemistry in zebrafish.

    Science.gov (United States)

    Saif, Muhammed; Chatterjee, Diptendu; Buske, Christine; Gerlai, Robert

    2013-04-15

    Zebrafish are gaining popularity in behavioural brain research as this species combines practical simplicity with system complexity. The dopaminergic system has been thoroughly investigated using mammals. Dopamine plays important roles in motor function and reward. Zebrafish have dopamine receptors homologous to mammalian counterparts, and dopamine receptor antagonists as well as alcohol have been shown to exert significant effects on this species as measured using HPLC or behavioural methods. The sight of conspecifics was previously shown to be rewarding in zebrafish but whether this stimulus affects the dopaminergic system has not been studied. Here, we present animated images of zebrafish to the experimental zebrafish subject for varying lengths of time and quantify the amount of dopamine, DOPAC, serotonin and 5HIAA extracted from the subject's brain immediately after the stimulus presentation using HPLC with electrochemical detection. We find conspecific images to induce a robust behavioural response (attraction) in experimental zebrafish. Importantly, dopamine and DOPAC levels significantly increased in response to the presentation of conspecific images but not to scrambled images. Last, serotonin and 5HIAA levels did not significantly change in response to the conspecific images. We conclude that our findings, together with pervious studies, now conclusively demonstrate that the behavioural response induced by the appearance of conspecifics is mediated, at least partly, by the dopaminergic system in zebrafish. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Modeling and remote sensing of human induced water cycle change

    Science.gov (United States)

    Pokhrel, Yadu N.

    2016-04-01

    The global water cycle has been profoundly affected by human land-water management especially during the last century. Since the changes in water cycle can affect the functioning of a wide range of biophysical and biogeochemical processes of the Earth system, it is essential to account for human land-water management in land surface models (LSMs) which are used for water resources assessment and to simulate the land surface hydrologic processes within Earth system models (ESMs). During the last two decades, noteworthy progress has been made in modeling human impacts on the water cycle but sufficient advancements have not yet been made, especially in representing human factors in large-scale LSMs toward integrating them into ESMs. In this study, an integrated modeling framework of continental-scale water cycle, with explicit representation of climate and human induced forces (e.g., irrigation, groundwater pumping) is developed and used to reconstruct the observed water cycle changes in the past and to attribute the observed changes to climatic and human factors. The new model builds upon two different previously developed models: a global LSM called the Human Impacts and GroundWater in the MATSIRO (HiGW-MAT) and a high-resolution regional groundwater model called the LEAF-Hydro-Flood. The model is used to retro-simulate the hydrologic stores and fluxes in close dialogue with in-situ and GRACE satellite based observations at a wide range of river basin scales around the world, with a particular focus on the changes in groundwater dynamics in northwest India, Pakistan, and the High Plains and Central Valley aquifers in the US.

  16. Innervation changes induced by inflammation of the rat thoracolumbar fascia.

    Science.gov (United States)

    Hoheisel, U; Rosner, J; Mense, S

    2015-08-06

    Recently, the fascia innervation has become an important issue, particularly the existence of nociceptive fibers. Fascia can be a source of pain in several disorders such as fasciitis and non-specific low back pain. However, nothing is known about possible changes of the fascia innervation under pathological circumstances. This question is important, because theoretically pain from the fascia cannot only be due to increased nociceptor discharges, but also to a denser innervation of the fascia by nociceptive endings. In this histological study, an inflammation was induced in the thoracolumbar fascia (TLF) of rats and the innervation by various fiber types compared between the inflamed and intact TLF. Although the TLF is generally considered to have proprioceptive functions, no corpuscular proprioceptors (Pacini and Ruffini corpuscles) were found. To obtain quantitative data, the length of fibers and free nerve endings were determined in the three layers of the rat TLF: inner layer (IL, adjacent to the multifidus muscle), middle layer (ML) and outer layer (OL). The main results were that the overall innervation density showed little change; however, there were significant changes in some of the layers. The innervation density was significantly decreased in the OL, but this change was partly compensated for by an increase in the IL. The density of substance P (SP)-positive - presumably nociceptive - fibers was significantly increased. In contrast, the postganglionic sympathetic fibers were significantly decreased. In conclusion, the inflamed TLF showed an increase of presumably nociceptive fibers, which may explain the pain from a pathologically altered fascia. The meaning of the decreased innervation by sympathetic fibers is obscure at present. The lack of proprioceptive corpuscular receptors within the TLF does not preclude its role as a proprioceptive structure, because some of the free nerve endings may function as proprioceptors. Copyright © 2015 IBRO. Published

  17. Iodine fortification may influence the age-related change in thyroid volume

    DEFF Research Database (Denmark)

    Motavaf, Anne Krejbjerg; Pedersen, Inge Bülow; Bjergved, Lena

    2014-01-01

    Improving PV system reliability and reducing maintenance and operating costs have become important factors in increasing the competitiveness of PV. Addressing these issues requires diagnostic methods that can detect and identify the occurrence and cause of power loss in the PV system, be it exter......Improving PV system reliability and reducing maintenance and operating costs have become important factors in increasing the competitiveness of PV. Addressing these issues requires diagnostic methods that can detect and identify the occurrence and cause of power loss in the PV system......, be it external, such as shading or soiling, or degradation or failure of the PV modules and balance-of-system components. This allows for performing preventive and/or reparative maintenance, thus minimizing further losses and costs. This article proposes a complete diagnostic method for detecting shading......, increased series-resistance losses, and potential-induced degradation of the PV generator by analysing changes its current-voltage characteristic curve. The diagnostic method is based on parameters that can be easily calculated from the shape of the current-voltage curve, making it machine-analysis friendly...

  18. Modelling of Longwall Mining-Induced Strata Permeability Change

    Science.gov (United States)

    Adhikary, D. P.; Guo, H.

    2015-01-01

    The field measurement of permeability within the strata affected by mining is a challenging and expensive task, thus such tests may not be carried out in large numbers to cover all the overburden strata and coal seams being affected by mining. However, numerical modelling in conjunction with a limited number of targeted field measurements can be used efficiently in assessing the impact of mining on a regional scale. This paper presents the results of underground packer testing undertaken at a mine site in New South Wales in Australia and numerical simulations conducted to assess the mining-induced strata permeability change. The underground packer test results indicated that the drivage of main headings (roadways) had induced a significant change in permeability into the solid coal barrier. Permeability increased by more than 50 times at a distance of 11.2-11.5 m from the roadway rib into the solid coal barrier. The tests conducted in the roof strata above the longwall goaf indicated more than 1,000-fold increase in permeability. The measured permeability values varied widely and strangely on a number of occasions; for example the test conducted from the main headings at the 8.2-8.5 m test section in the solid coal barrier showed a decline in permeability value as compared to that at the 11.2-11.5 m section contrary to the expectations. It is envisaged that a number of factors during the tests might have had affected the measured values of permeability: (a) swelling and smearing of the borehole, possibly lowering the permeability values; (b) packer bypass by larger fractures; (c) test section lying in small but intact (without fractures) rock segment, possibly resulting in lower permeability values; and (d) test section lying right at the extensive fractures, possibly measuring higher permeability values. Once the anomalous measurement data were discarded, the numerical model results could be seen to match the remaining field permeability measurement data

  19. Music-induced changes in functional cerebral asymmetries.

    Science.gov (United States)

    Hausmann, Markus; Hodgetts, Sophie; Eerola, Tuomas

    2016-04-01

    After decades of research, it remains unclear whether emotion lateralization occurs because one hemisphere is dominant for processing the emotional content of the stimuli, or whether emotional stimuli activate lateralised networks associated with the subjective emotional experience. By using emotion-induction procedures, we investigated the effect of listening to happy and sad music on three well-established lateralization tasks. In a prestudy, Mozart's piano sonata (K. 448) and Beethoven's Moonlight Sonata were rated as the most happy and sad excerpts, respectively. Participants listened to either one emotional excerpt, or sat in silence before completing an emotional chimeric faces task (Experiment 1), visual line bisection task (Experiment 2) and a dichotic listening task (Experiment 3 and 4). Listening to happy music resulted in a reduced right hemispheric bias in facial emotion recognition (Experiment 1) and visuospatial attention (Experiment 2) and increased left hemispheric bias in language lateralization (Experiments 3 and 4). Although Experiments 1-3 revealed an increased positive emotional state after listening to happy music, mediation analyses revealed that the effect on hemispheric asymmetries was not mediated by music-induced emotional changes. The direct effect of music listening on lateralization was investigated in Experiment 4 in which tempo of the happy excerpt was manipulated by controlling for other acoustic features. However, the results of Experiment 4 made it rather unlikely that tempo is the critical cue accounting for the effects. We conclude that listening to music can affect functional cerebral asymmetries in well-established emotional and cognitive laterality tasks, independent of music-induced changes in the emotion state. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Drought-Induced Leaf Proteome Changes in Switchgrass Seedlings

    Directory of Open Access Journals (Sweden)

    Zhujia Ye

    2016-08-01

    Full Text Available Switchgrass (Panicum virgatum is a perennial crop producing deep roots and thus highly tolerant to soil water deficit conditions. However, seedling establishment in the field is very susceptible to prolonged and periodic drought stress. In this study, a “sandwich” system simulating a gradual water deletion process was developed. Switchgrass seedlings were subjected to a 20-day gradual drought treatment process when soil water tension was increased to 0.05 MPa (moderate drought stress and leaf physiological properties had expressed significant alteration. Drought-induced changes in leaf proteomes were identified using the isobaric tags for relative and absolute quantitation (iTRAQ labeling method followed by nano-scale liquid chromatography mass spectrometry (nano-LC-MS/MS analysis. Additionally, total leaf proteins were processed using a combinatorial library of peptide ligands to enrich for lower abundance proteins. Both total proteins and those enriched samples were analyzed to increase the coverage of the quantitative proteomics analysis. A total of 7006 leaf proteins were identified, and 257 (4% of the leaf proteome expressed a significant difference (p < 0.05, fold change <0.6 or >1.7 from the non-treated control to drought-treated conditions. These proteins are involved in the regulation of transcription and translation, cell division, cell wall modification, phyto-hormone metabolism and signaling transduction pathways, and metabolic pathways of carbohydrates, amino acids, and fatty acids. A scheme of abscisic acid (ABA-biosynthesis and ABA responsive signal transduction pathway was reconstructed using these drought-induced significant proteins, showing systemic regulation at protein level to deploy the respective mechanism. Results from this study, in addition to revealing molecular responses to drought stress, provide a large number of proteins (candidate genes that can be employed to improve switchgrass seedling growth and

  1. Moderators of noise-induced cognitive change in healthy adults

    Directory of Open Access Journals (Sweden)

    Bernice AL Wright

    2016-01-01

    Full Text Available Environmental noise causes cognitive impairment, particularly in executive function and episodic memory domains, in healthy populations. However, the possible moderating influences on this relationship are less clear. This study assessed 54 healthy participants (24 men on a cognitive battery (measuring psychomotor speed, attention, executive function, working memory, and verbal learning and memory under three (quiet, urban, and social noise conditions. IQ, subjective noise sensitivity, sleep, personality, paranoia, depression, anxiety, stress, and schizotypy were assessed on a single occasion. We found significantly slower psychomotor speed (urban, reduced working memory and episodic memory (urban and social, and more cautious decision-making (executive function, urban under noise conditions. There was no effect of sex. Variance in urban noise-induced changes in psychomotor speed, attention, Trail Making B-A (executive function, and immediate recall and social noise-induced changes in verbal fluency (executive function and immediate recall were explained by a combination of baseline cognition and paranoia, noise sensitivity, sleep, or cognitive disorganization. Higher baseline cognition (but not IQ predicted greater impairment under urban and social noise for most cognitive variables. Paranoia predicted psychomotor speed, attention, and executive function impairment. Subjective noise sensitivity predicted executive function and memory impairment. Poor sleep quality predicted less memory impairment. Finally, lower levels of cognitive disorganization predicted slower psychomotor speed and greater memory impairment. The identified moderators should be considered in studies aiming to reduce the detrimental effects of occupational and residential noise. These results highlight the importance of studying noise effects in clinical populations characterized by high levels of the paranoia, sleep disturbances, noise sensitivity, and cognitive

  2. LSD-induced entropic brain activity predicts subsequent personality change.

    Science.gov (United States)

    Lebedev, A V; Kaelen, M; Lövdén, M; Nilsson, J; Feilding, A; Nutt, D J; Carhart-Harris, R L

    2016-09-01

    Personality is known to be relatively stable throughout adulthood. Nevertheless, it has been shown that major life events with high personal significance, including experiences engendered by psychedelic drugs, can have an enduring impact on some core facets of personality. In the present, balanced-order, placebo-controlled study, we investigated biological predictors of post-lysergic acid diethylamide (LSD) changes in personality. Nineteen healthy adults underwent resting state functional MRI scans under LSD (75µg, I.V.) and placebo (saline I.V.). The Revised NEO Personality Inventory (NEO-PI-R) was completed at screening and 2 weeks after LSD/placebo. Scanning sessions consisted of three 7.5-min eyes-closed resting-state scans, one of which involved music listening. A standardized preprocessing pipeline was used to extract measures of sample entropy, which characterizes the predictability of an fMRI time-series. Mixed-effects models were used to evaluate drug-induced shifts in brain entropy and their relationship with the observed increases in the personality trait openness at the 2-week follow-up. Overall, LSD had a pronounced global effect on brain entropy, increasing it in both sensory and hierarchically higher networks across multiple time scales. These shifts predicted enduring increases in trait openness. Moreover, the predictive power of the entropy increases was greatest for the music-listening scans and when "ego-dissolution" was reported during the acute experience. These results shed new light on how LSD-induced shifts in brain dynamics and concomitant subjective experience can be predictive of lasting changes in personality. Hum Brain Mapp 37:3203-3213, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  3. Large Eddy Simulations of Volume Restriction Effects on Canopy-Induced Increased-Uplift Regions

    Science.gov (United States)

    Chatziefstratiou, E.; Bohrer, G.; Velissariou, V.

    2012-12-01

    ABSTRACT Previous modeling and empirical work have shown the development of important areas of increased uplift past forward-facing steps, and recirculation zones past backward-facing steps. Forests edges represent a special kind of step - a semi-porous one. Current models of the effects of forest edges on the flow represent the forest with a prescribed drag term and does not account for the effects of the solid volume in the forest that restrict the airflow. The RAMS-based Forest Large Eddy Simulation (RAFLES) resolves flows inside and above forested canopies. RAFLES is spatially explicit, and uses the finite volume method to solve a descretized set of Navier-Stokes equations. It accounts for vegetation drag effects on the flow and on the flux exchange between the canopy and the canopy air, proportional to the local leaf density. For a better representation of the vegetation structure in the numerical grid within the canopy sub-domain, the model uses a modified version of the cut cell coordinate system. The hard volume of vegetation elements, in forests, or buildings, in urban environments, within each numerical grid cell is represented via a sub-grid-scale process that shrinks the open apertures between grid cells and reduces the open cell volume. We used RAFLES to simulate the effects of a canopy of varying foliage and stem densities on flow over virtual qube-shaped barriers under neutrally buoyant conditions. We explicitly tested the effects of the numerical representation of volume restriction, independent of the effects of the leaf drag by comparing drag-only simulations, where we prescribed no volume or aperture restriction to the flow, restriction-only simulations, where we prescribed no drag, and control simulations, where both drag and volume plus aperture restriction were included. Our simulations show that representation of the effects of the volume and aperture restriction due to obstacles to flow is important (figure 1) and leads to differences in the

  4. Does upper premolar extraction affect the changes of pharyngeal airway volume after bimaxillary surgery in skeletal class III patients?

    Science.gov (United States)

    Kim, Min-Ah; Park, Yang-Ho

    2014-01-01

    The purpose of this study was to assess the pharyngeal airway volume change after bimaxillary surgery in patients with skeletal Class III malocclusion and evaluate the difference in postoperative pharyngeal airway space between upper premolar extraction cases and nonextraction cases. Cone-beam computed tomographic scans were obtained for 23 patients (13 in extraction group and 10 in nonextraction group) who were diagnosed with mandibular prognathism before surgery (T0) and then 2 months (T2) and 6 months after surgery (T3). Using InVivoDental 3-dimensional imaging software, volumetric changes in the pharyngeal airway space were assessed at T0, T2, and T3. The Wilcoxon signed-rank test was used to determine whether there were significant changes in pharyngeal airway volume between time points. The Mann-Whitney U test was used to determine whether there were significant differences in volumetric changes between the extraction and nonextraction groups. Volumes in all subsections of the pharyngeal airway were decreased (P bimaxillary surgery. Copyright © 2014 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  5. Effects of prenatal alcohol exposure on the development of white matter volume and change in executive function

    Directory of Open Access Journals (Sweden)

    P. Gautam

    2014-01-01

    Full Text Available Prenatal alcohol exposure can cause a wide range of deficits in executive function that persist throughout life, but little is known about how changes in brain structure relate to cognition in affected individuals. In the current study, we predicted that the rate of white matter volumetric development would be atypical in children with fetal alcohol spectrum disorders (FASD when compared to typically developing children, and that the rate of change in cognitive function would relate to differential white matter development between groups. Data were available for 103 subjects [49 with FASD, 54 controls, age range 6–17, mean age = 11.83] with 153 total observations. Groups were age-matched. Participants underwent structural magnetic resonance imaging (MRI and an executive function (EF battery. Using white matter volumes measured bilaterally for frontal and parietal regions and the corpus callosum, change was predicted by modeling the effects of age, intracranial volume, sex, and interactions with exposure status and EF measures. While both groups showed regional increases in white matter volumes and improvement in cognitive performance over time, there were significant effects of exposure status on age-related relationships between white matter increases and EF measures. Specifically, individuals with FASD consistently showed a positive relationship between improved cognitive function and increased white matter volume over time, while no such relationships were seen in controls. These novel results relating improved cognitive function with increased white matter volume in FASD suggest that better cognitive outcomes could be possible for FASD subjects through interventions that enhance white matter plasticity.

  6. Force-Induced Changes in Subnuclear Movement and Rheology

    Science.gov (United States)

    Booth-Gauthier, Elizabeth A.; Alcoser, Turi A.; Yang, Ge; Dahl, Kris N.

    2012-01-01

    Extracellular mechanical forces result in changes in gene expression, but it is unclear how cells are able to permanently adapt to new mechanical environments because chemical signaling pathways are short-lived. We visualize force-induced changes in nuclear rheology to examine short- and long-time genome organization and movements. Punctate labels in the nuclear interior of HeLa, human umbilical vein endothelial, and osteosarcoma (Saos-2) cells allow tracking of nuclear movements in cells under varying levels of shear and compressive force. Under adequate shear stress two distinct regimes develop in cells under mechanical stimulation: an initial event of increased intranuclear movement followed by a regime of intranuclear movements that reflect the dose of applied force. At early times there is a nondirectionally oriented response with a small increase in nuclear translocations. After 30 min, there is a significant increase in nuclear movements, which scales with the amount of shear or compressive stress. The similarities in the nuclear response to shear and compressive stress suggest that the nucleus is a mechanosensitive element within the cell. Thus, applied extracellular forces stimulate intranuclear movements, resulting in repositioning of nuclear bodies and the associated chromatin within the nucleus. PMID:23260044

  7. Ocular histopathological changes after eyeball enucleation induced by corneal trauma

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective: To observe the ocular histopathological changes aftereyeball enucleation induced by corneal trauma.Methods: Light microscopic examination was done on 117 eyeball specimens enucleated after corneal trauma (18 with corneal fissure and 99 with corneal perforating trauma).Results: Acute, subacute or chronic inflammatory changes, and fibrous membrane formation were observed in well-closed corneal wounds, whereas inflammation, atrophy and scar were observed in the focal tissues. But at the late period, secondary glaucoma, retinal detachment, endophthalmitis and eyeball atrophy resulted in blindness. Corneal fistula was observed in those with inadequate cure of wounds caused by ingrowth of corneal epithelium, embedment of iris and vitreous body, and large area of centrally located tissue deficiency of the corneal. A high incidence of endophthalmitis was noted due to the presence of corneal fistula. Severe inflammation was observed in the anterior segmental tissues with fibrous infiltration in the anterior chamber, which might result in rapid destruction of the eyeballs.Conclusions: Ocular pathology varies with the difference of the position, form, size and closing conditions of the corneal laceration after trauma.

  8. Gravity's Rainbow induces topology change

    Energy Technology Data Exchange (ETDEWEB)

    Garattini, Remo [Universita degli Studi di Bergamo, Facolta di Ingegneria, Dalmine, Bergamo (Italy); I.N.F.N.-sezione di Milano, Milan (Italy); Lobo, Francisco S.N. [Centro de Astronomia e Astrofisica da Universidade de Lisboa, Lisbon (Portugal)

    2014-05-15

    In this work, we explore the possibility that quantum fluctuations induce a topology change, in the context of Gravity's Rainbow. A semiclassical approach is adopted, where the graviton one-loop contribution to a classical energy in a background spacetime is computed through a variational approach with Gaussian trial wave functionals. The energy density of the graviton one-loop contribution, or equivalently the background spacetime, is then let to evolve, and consequently the classical energy is determined. More specifically, the background metric is fixed to be Minkowskian in the equation governing the quantum fluctuations, which behaves essentially as a backreaction equation, and the quantum fluctuations are let to evolve; the classical energy, which depends on the evolved metric functions, is then evaluated. Analyzing this procedure, a natural ultraviolet cutoff is obtained, which forbids the presence of an interior spacetime region, and this may result in a multiply connected spacetime. Thus, in the context of Gravity's Rainbow, this process may be interpreted as a change in topology, and in principle it results in the presence of a planckian wormhole. (orig.)

  9. Malaria-induced changes in host odors enhance mosquito attraction.

    Science.gov (United States)

    De Moraes, Consuelo M; Stanczyk, Nina M; Betz, Heike S; Pulido, Hannier; Sim, Derek G; Read, Andrew F; Mescher, Mark C

    2014-07-29

    Vector-borne pathogens may alter traits of their primary hosts in ways that influence the frequency and nature of interactions between hosts and vectors. Previous work has reported enhanced mosquito attraction to host organisms infected with malaria parasites but did not address the mechanisms underlying such effects. Here we document malaria-induced changes in the odor profiles of infected mice (relative to healthy individuals) over the course of infection, as well as effects on the attractiveness of infected hosts to mosquito vectors. We observed enhanced mosquito attraction to infected mice during a key period after the subsidence of acute malaria symptoms, but during which mice remained highly infectious. This attraction corresponded to an overall elevation in the volatile emissions of infected mice observed during this period. Furthermore, data analyses--using discriminant analysis of principal components and random forest approaches--revealed clear differences in the composition of the volatile blends of infected and healthy individuals. Experimental manipulation of individual compounds that exhibited altered emission levels during the period when differential vector attraction was observed also elicited enhanced mosquito attraction, indicating that compounds being influenced by malaria infection status also mediate vector host-seeking behavior. These findings provide important insights into the cues that mediate vector attraction to hosts infected with transmissible stages of malaria parasites, as well as documenting characteristic changes in the odors of infected individuals that may have potential value as diagnostic biomarkers of infection.

  10. Structural change of human hair induced by mercury exposure.

    Science.gov (United States)

    Xing, Xueqing; Du, Rong; Li, Yufeng; Li, Bai; Cai, Quan; Mo, Guang; Gong, Yu; Chen, Zhongjun; Wu, Zhonghua

    2013-10-01

    Mercury is one of the most hazardous pollutants in the environment. In this paper, the structural change of human hair induced by mercury exposure was studied. Human hair samples were, respectively, collected from the normal Beijing area and the Hg-contaminated Wanshan area of the Guizhou Province, China. Inductively coupled plasma mass spectroscopy was used to detect the element contents. A small angle X-ray scattering technique was used to probe the structural change. Three reflections with 8.8, 6.7, and 4.5 nm spacing were compared between the normal and the Hg-contaminated hair samples. The results confirm that the 4.5 nm reflection is from the ordered fibrillar structure of glycosaminoglycan (GAG) in proteoglycan (PG) that composes the matrix around the intermediate filaments. The increase of Ca content makes the regular oriented fibrillar structure of GAG transform to a random oriented one, broadening the angular extent of the reflection with 4.5 nm spacing. However, overdose Hg makes the core proteins where the ordered fibrils of GAG are attached become coiled, which destroys the ordered arrangements of fibrillar GAG in PG, resulting in the disappearance of the reflections with 4.5 nm spacing. The disappearance of the 4.5 nm reflection can be used as a bioindicator of overdose Hg contamination to the human body. A supercoiled-coil model of hair nanoscale structure and a possible mechanism of mercury effect in human hair are proposed in this paper.

  11. Paradoxical relationship between atriopeptin plasma levels and diuresis-natriuresis induced by acute volume expansion.

    OpenAIRE

    Sakata, M.; Greenwald, J E; Needleman, P

    1988-01-01

    Surgical removal of one or both atrial appendages was employed in rats to reduce the intrinsic stores of atriopeptin (AP). In conscious rats (with intact baroreceptor reflexes), bilateral or unilateral atrial appendectomy suppressed the diuresis and natriuresis produced by acute volume expansion. Surprisingly, volume expansion (with 4% bovine serum albumin in saline at 1.5 ml/kg per min for 15 min) did not result in an increase in plasma AP immunoreactivity (APir) in control or atrial-appende...

  12. Semiautomated three-dimensional segmentation software to quantify carpal bone volume changes on wrist CT scans for arthritis assessment.

    Science.gov (United States)

    Duryea, J; Magalnick, M; Alli, S; Yao, L; Wilson, M; Goldbach-Mansky, R

    2008-06-01

    Rapid progression of joint destruction is an indication of poor prognosis in patients with rheumatoid arthritis. Computed tomography (CT) has the potential to serve as a gold standard for joint imaging since it provides high resolution three-dimensional (3D) images of bone structure. The authors have developed a method to quantify erosion volume changes on wrist CT scans. In this article they present a description and validation of the methodology using multiple scans of a hand phantom and five human subjects. An anthropomorphic hand phantom was imaged with a clinical CT scanner at three different orientations separated by a 30-deg angle. A reader used the semiautomated software tool to segment the individual carpal bones of each CT scan. Reproducibility was measured as the root-mean-square standard deviation (RMMSD) and coefficient of variation (CoV) between multiple measurements of the carpal volumes. Longitudinal erosion progression was studied by inserting simulated erosions in a paired second scan. The change in simulated erosion size was calculated by performing 3D image registration and measuring the volume difference between scans in a region adjacent to the simulated erosion. The RMSSD for the total carpal volumes was 21.0 mm3 (CoV = 1.3%) for the phantom, and 44.1 mm3 (CoV = 3.0%) for the in vivo subjects. Using 3D registration and local volume difference calculations, the RMMSD was 1.0-3.0 mm3 The reader time was approximately 5 min per carpal bone. There was excellent agreement between the measured and simulated erosion volumes. The effect of a poorly measured volume for a single erosion is mitigated by the large number of subjects that would comprise a clinical study and that there will be many erosions measured per patient. CT promises to be a quantifiable tool to measure erosion volumes and may serve as a gold standard that can be used in the validation of other modalities such as magnetic resonance imaging.

  13. Antioxidants and NOS inhibitors selectively targets manganese-induced cell volume via Na-K-Cl cotransporter-1 in astrocytes.

    Science.gov (United States)

    Alahmari, Khalid A; Prabhakaran, Harini; Prabhakaran, Krishnan; Chandramoorthy, Harish C; Ramugounder, Ramakrishnan

    2015-06-12

    Manganese has shown to be involved in astrocyte swelling. Several factors such as transporters, exchangers and ion channels are attributed to astrocyte swelling as a result in the deregulation of cell volume. Products of oxidation and nitration have been implied to be involved in the pathophysiology of swelling; however, the direct link and mechanism of manganese induced astrocyte swelling has not been fully elucidated. In the current study, we used rat primary astrocyte cultures to investigate the activation of Na-K-Cl cotransporter-1 (NKCC1) a downstream mechanism for free radical induced astrocyte swelling as a result of manganese toxicity. Our results showed manganese, oxidants and NO donors as potent inducer of oxidation and nitration of NKCC1. Our results further confirmed that manganese (50 μM) increased the total protein, phosphorylation and activity of NKCC1 as well as cell volume (p manganese or oxidants and NO induced activation, oxidation/nitration of NKCC1 play an important role in the astrocyte swelling. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Long-term global and regional brain volume changes following severe traumatic brain injury: A longitudinal study with clinical correlates

    DEFF Research Database (Denmark)

    Sidaros, Annette; Skimminge, Arnold Jesper Møller; Liptrot, Matthew George;

    2009-01-01

    Traumatic brain injury (TBI) results in neurodegenerative changes that progress for months, perhaps even years post-injury. However, there is little information on the spatial distribution and the clinical significance of this late atrophy. In 24 patients who had sustained severe TBI we acquired 3D...... scan time point using SIENAX. Regional distribution of atrophy was evaluated using tensor-based morphometry (TBM). At the first scan time point, brain parenchymal volume was reduced by mean 8.4% in patients as compared to controls. During the scan interval, patients exhibited continued atrophy...... with percent brain volume change (%BVC) ranging between − 0.6% and − 9.4% (mean − 4.0%). %BVC correlated significantly with injury severity, functional status at both scans, and with 1-year outcome. Moreover, %BVC improved prediction of long-term functional status over and above what could be predicted using...

  15. Choroidal and macular thickness changes induced by cataract surgery

    Directory of Open Access Journals (Sweden)

    Falcão MS

    2013-12-01

    Full Text Available Manuel S Falcão,1,2 Nuno M Gonçalves,2 Paulo Freitas-Costa,1,3 João B Beato,2 Amândio Rocha-Sousa,1,2 Ângela Carneiro,1,2 Elisete M Brandão,2 Fernando M Falcão-Reis1,21Department of Sense Organs, Faculty of Medicine, University of Porto, 2Department of Ophthalmology of Hospital de São João, 3Department of Anatomy, Faculty of Medicine, University of Porto, Porto, PortugalBackground: The aim of this study was to evaluate the effect of uneventful phacoemulsification on the morphology and thickness of the macula, the submacular choroid, and the peripapillary choroid.Methods: In 14 eyes from 14 patients, retinal macular thickness, choroidal submacular thickness, and choroidal peripapillary thickness were measured preoperatively and at one week and one month after phacoemulsification using enhanced depth imaging spectral domain optical coherence tomography. Changes in thickness of the different ocular tissues were evaluated.Results: There was a statistically significant increase in mean retinal macular thickness at one month. In horizontal scans, the mean increase was +8.67±6.75 µm (P<0.001, and in vertical scans, the mean increase was +8.80±7.07 µm (P=0.001. However, there were no significant changes in choroidal morphology in the submacular and peripapillary areas one month after surgery. In vertical scans, there was a nonsignificant increase in choroidal thickness (+4.21±20.2 µm; P=0.47 whilst in horizontal scans a nonsignificant decrease was recorded (−9.11±39.59 µm; P=0.41. In peripapillary scans, a nonsignificant increase in mean choroidal thickness was registered (+3.25±11.80 µm; P=0.36.Conclusion: Uncomplicated phacoemulsification induces nonpathologic increases in retinal macular thickness probably due to the inflammatory insult of the surgery; however these changes are not accompanied by significant changes in choroidal thickness. In the posterior segment, the morphologic response to the inflammatory insult of

  16. FEV manoeuvre induced changes in breath VOC compositions: an unconventional view on lung function tests

    Science.gov (United States)

    Sukul, Pritam; Schubert, Jochen K.; Oertel, Peter; Kamysek, Svend; Taunk, Khushman; Trefz, Phillip; Miekisch, Wolfram

    2016-06-01

    Breath volatile organic compound (VOC) analysis can open a non-invasive window onto pathological and metabolic processes in the body. Decades of clinical breath-gas analysis have revealed that changes in exhaled VOC concentrations are important rather than disease specific biomarkers. As physiological parameters, such as respiratory rate or cardiac output, have profound effects on exhaled VOCs, here we investigated VOC exhalation under respiratory manoeuvres. Breath VOCs were monitored by means of real-time mass-spectrometry during conventional FEV manoeuvres in 50 healthy humans. Simultaneously, we measured respiratory and hemodynamic parameters noninvasively. Tidal volume and minute ventilation increased by 292 and 171% during the manoeuvre. FEV manoeuvre induced substance specific changes in VOC concentrations. pET-CO2 and alveolar isoprene increased by 6 and 21% during maximum exhalation. Then they decreased by 18 and 37% at forced expiration mirroring cardiac output. Acetone concentrations rose by 4.5% despite increasing minute ventilation. Blood-borne furan and dimethyl-sulphide mimicked isoprene profile. Exogenous acetonitrile, sulphides, and most aliphatic and aromatic VOCs changed minimally. Reliable breath tests must avoid forced breathing. As isoprene exhalations mirrored FEV performances, endogenous VOCs might assure quality of lung function tests. Analysis of exhaled VOC concentrations can provide additional information on physiology of respiration and gas exchange.

  17. Quantum-Mechanical QSPR Models for Polymerization Volume Change of Epoxides and Methacrylates Based on Mercury Dilatometry Results

    OpenAIRE

    Miller, Matthew D.; Holder, Andrew J.; Kilway, Kathleen V.; Giese, Gregory J.; Finley, Jason E.; Travis, DeAnna M.; Iwai, Benjamin T.; Eick, J. David

    2006-01-01

    Polymerization volume change (PVC) was measured systematically using mercury dilatometry for 41 epoxide and methacrylate monomers with quartz filler. Quantitative structure property relationship (QSPR) models were developed based on this previously unreported data to gain insight in the data collection method for future models. Successful models included only data from those samples which polymerized to hardness. The most significant descriptors in these models related to monomer reactivity. ...

  18. Changes in hippocampal volume and neuron number co-occur with memory decline in old homing pigeons (Columba livia).

    Science.gov (United States)

    Coppola, Vincent J; Kanyok, Nate; Schreiber, Austin J; Flaim, Mary E; Bingman, Verner P

    2016-05-01

    The mammalian hippocampus is particularly susceptible to age-related structural changes, which have been used to explain, in part, age-related memory decline. These changes are generally characterized by atrophy (e.g., a decrease in volume and number of synaptic contacts). Recent studies have reported age-related spatial memory deficits in older pigeons similar to those seen in older mammals. However, to date, little is known about any co-occurring changes in the aging avian hippocampal formation (HF). In the current study, it was found that the HF of older pigeons was actually larger and contained more neurons than the HF of younger pigeons, a finding that suggests that the pattern of structural changes during aging in the avian HF is different from that seen in the mammalian hippocampus. A working hypothesis for relating the observed structural changes with spatial-cognitive decline is offered.

  19. Serotoninergic Modulation of Basal Cardiovascular Responses and Responses Induced by Isotonic Extracellular Volume Expansion in Rats.

    Science.gov (United States)

    Semionatto, Isadora Ferraz; Raminelli, Adrieli Oliveira; Alves, Angelica Cristina; Capitelli, Caroline Santos; Chriguer, Rosangela Soares

    2017-02-01

    Isotonic blood volume expansion (BVE) induced alterations of sympathetic and parasympathetic activity in the heart and blood vessels, which can be modulated by serotonergic pathways. To evaluate the effect of saline or serotonergic agonist (DOI) administration in the hypothalamic paraventricular nucleus (PVN) on cardiovascular responses after BVE. We recorded pulsatile blood pressure through the femoral artery to obtain the mean arterial pressure (MAP), systolic (SBP) and diastolic blood pressure (DBP), heart rate (HR) and the sympathetic-vagal ratio (LF/HF) of Wistar rats before and after they received bilateral microinjections of saline or DOI into the PVN, followed by BVE. No significant differences were observed in the values of the studied variables in the different treatments from the control group. However, when animals are treated with DOI followed by BVE there is a significant increase in relation to the BE control group in all the studied variables: MBP (114.42±7.85 vs 101.34±9.17); SBP (147.23±14.31 vs 129.39±10.70); DBP (98.01 ±4.91 vs 87.31±8.61); HR (421.02±43.32 vs 356.35±41.99); and LF/HF ratio (2.32±0.80 vs 0.27±0.32). The present study showed that the induction of isotonic BVE did not promote alterations in MAP, HR and LF/HF ratio. On the other hand, the injection of DOI into PVN of the hypothalamus followed by isotonic BVE resulted in a significant increase of all variables. These results suggest that serotonin induced a neuromodulation in the PVN level, which promotes an inhibition of the baroreflex response to BVE. Therefore, the present study suggests the involvement of the serotonergic system in the modulation of vagal reflex response at PVN in the normotensive rats. Expansão de volume extracelular (EVEC) promove alterações da atividade simpática e parassimpática no coração e vasos sanguíneos, os quais podem ser moduladas por vias serotoninérgicas. Avaliar o efeito da administração de salina ou agonista serotonin

  20. Pituitary volumes of the patients with borderline personality disorder are not changed.

    Science.gov (United States)

    Atmaca, Murad; Karakoc, Tevfik; Mermi, Osman; Kilic, Faruk; Gurok, M Gurkan; Yildirim, Hanefi

    2015-01-01

    Although it has important relationships with psychiatric symptoms via the hypothalamic-pituitary-adrenal axis, there have been limited investigations of pituitary neuroimaging in psychiatric disorder. Moreover, there have been no studies of borderline personality disorder. In the present investigation, we examined pituitary gland volumes in patients with borderline personality disorder. Seventeen right-handed female patients with borderline personality disorder, selected among the patients who had presented to Firat University School of Medicine Department of Psychiatry outpatient and inpatient clinics, and the same number of healthy control subjects were included in the present investigation. Pituitary gland volumes were manually detected. The results demonstrated that the mean volumes of the gland of the patients with borderline personality disorder were not significantly different than those of healthy control subjects (mean volume of 0.79 cm3 in the patient group, with a value of SD±0.11 and 0.81 cm3 in the healthy control group, with a value of SD±0.23; t=-0.21; p>0.05). © The Author(s) 2015.

  1. Estimating changes in Stroke Volume by non-invasive pulse-oximetry Pulse Transit Time Measurements

    NARCIS (Netherlands)

    ten Bokkel-Andela, J.; Poterman, Marieke; Scheeren, Thomas; Kalmar, A.F.

    2015-01-01

    Background and Goal of Study:  Pulse wave transit time (PTT), the interval between the R-wave peak on an electrocardiogram (ECG) and arrival of the pulse waves in the periphery (e.g. the finger), is reported to be a reliable estimate for stroke volume[1,2]. In this study, the PTT based on ECG and th

  2. Penicillin-induced epilepsy model in rats: dose-dependant effect on hippocampal volume and neuron number.

    Science.gov (United States)

    Akdogan, Ilgaz; Adiguzel, Esat; Yilmaz, Ismail; Ozdemir, M Bulent; Sahiner, Melike; Tufan, A Cevik

    2008-10-22

    This study was designed to evaluate the penicillin-induced epilepsy model in terms of dose-response relationship of penicillin used to induce epilepsy seizure on hippocampal neuron number and hippocampal volume in Sprague-Dawley rats. Seizures were induced with 300, 500, 1500 and 2000IU of penicillin-G injected intracortically in rats divided in four experimental groups, respectively. Control group was injected intracortically with saline. Animals were decapitated on day 7 of treatment and brains were removed. The total neuron number of pyramidal cell layer from rat hippocampus was estimated using the optical fractionator method. The volume of same hippocampal areas was estimated using the Cavalieri method. Dose-dependent decrease in hippocampal neuron number was observed in three experimental groups (300, 500 and 1500IU of penicillin-G), and the effects were statistically significant when compared to the control group (P<0.009). Dose-dependent decrease in hippocampal volume, on the other hand, was observed in all three of these groups; however, the difference compared to the control group was only statistically significant in 1500IU of penicillin-G injected group (P<0.009). At the dose of 2000IU penicillin-G, all animals died due to status seizures. These results suggest that the appropriate dose of penicillin has to be selected for a given experimental epilepsy study in order to demonstrate the relevant epileptic seizure and its effects. Intracortical 1500IU penicillin-induced epilepsy model may be a good choice to practice studies that investigate neuroprotective mechanisms of the anti-epileptic drugs.

  3. Rapid changes of induced volatile organic compounds in Pinus massoniana

    Institute of Scientific and Technical Information of China (English)

    REN Qin; JIN Youju; HU Yongiian; CHEN Huajun; LI Zhenyu

    2007-01-01

    Using the thermal-desorption cold trap gas chromatography/mass spectrometer(TCT-GC-MS)technique,the composition and relative contents of volatile compounds were analyzed in undamaged(control),insect-damaged(ID)and artificially-damaged(AD)leaves ofPinus massoniana in field at different times and levels of damage.Results showed that although volatile substances were highly released earlier in AD leaves plants,they were significantly less abundant in AD than in ID leaves treatments.Also,the damage level considerably influenced the changes of induced volatile products from leaves.Compared with the control,the emission rate of camphene,β-pinene,phellandrene,caryophyllene and(E)farnesene was high after 1 h in 25%-40% ID-affected leaves,whereas that of tricyclene,myrcene,camphene,β-Pinene,phellandrene and caryophyllene reached its maximum after 24 h in 60%-75% D-affected leaves.In the same manner,some volatile compounds in the AD leaves treatment displayed their peaks just after 1 h,but others after 24 h.The AD and ID leaves at the damage level of 25%-40% did not exhibit an obvious regularity with time;however,in 60%- 75% AD leaves,peaks of volatile substances were attained after 1 or 2 h.Our results also showed that the relative content ofβ-pinene increased and was higher in damaged than control plants,β-pinene plays an important role in inducing the insect resistance of P.massoniana trees.

  4. Drought-Induced Leaf Proteome Changes in Switchgrass Seedlings.

    Science.gov (United States)

    Ye, Zhujia; Sangireddy, Sasikiran; Okekeogbu, Ikenna; Zhou, Suping; Yu, Chih-Li; Hui, Dafeng; Howe, Kevin J; Fish, Tara; Thannhauser, Theodore W

    2016-01-01

    Switchgrass (Panicum virgatum) is a perennial crop producing deep roots and thus highly tolerant to soil water deficit conditions. However, seedling establishment in the field is very susceptible to prolonged and periodic drought stress. In this study, a "sandwich" system simulating a gradual water deletion process was developed. Switchgrass seedlings were subjected to a 20-day gradual drought treatment process when soil water tension was increased to 0.05 MPa (moderate drought stress) and leaf physiological properties had expressed significant alteration. Drought-induced changes in leaf proteomes were identified using the isobaric tags for relative and absolute quantitation (iTRAQ) labeling method followed by nano-scale liquid chromatography mass spectrometry (nano-LC-MS/MS) analysis. Additionally, total leaf proteins were processed using a combinatorial library of peptide ligands to enrich for lower abundance proteins. Both total proteins and those enriched samples were analyzed to increase the coverage of the quantitative proteomics analysis. A total of 7006 leaf proteins were identified, and 257 (4% of the leaf proteome) expressed a significant difference (p 1.7) from the non-treated control to drought-treated conditions. These proteins are involved in the regulation of transcription and translation, cell division, cell wall modification, phyto-hormone metabolism and signaling transduction pathways, and metabolic pathways of carbohydrates, amino acids, and fatty acids. A scheme of abscisic acid (ABA)-biosynthesis and ABA responsive signal transduction pathway was reconstructed using these drought-induced significant proteins, showing systemic regulation at protein level to deploy the respective mechanism. Results from this study, in addition to revealing molecular responses to drought stress, provide a large number of proteins (candidate genes) that can be employed to improve switchgrass seedling growth and establishment under soil drought conditions (Data are

  5. Hypergravity-induced changes in gene expression in Arabidopsis hypocotyls.

    Science.gov (United States)

    Yoshioka, R; Soga, K; Wakabayashi, K; Takeba, G; Hoson, T

    2003-01-01

    Under hypergravity conditions, the cell wall of stem organs becomes mechanically rigid and elongation growth is suppressed, which can be recognized as the mechanism for plants to resist gravitational force. The changes in gene expression by hypergravity treatment were analyzed in Arabidopsis hypocotyls by the differential display method, for identifying genes involved in hypergravity-induced growth suppression. Sixty-two cDNA clones were expressed differentially between the control and 300 g conditions: the expression levels of 39 clones increased, whereas those of 23 clones decreased under hypergravity conditions. Sequence analysis and database searching revealed that 12 clones, 9 up-regulated and 3 down-regulated, have homology to known proteins. The expression of these genes was further analyzed using RT-PCR. Finally, six genes were confirmed to be up-regulated by hypergravity. One of such genes encoded 3-hydroxy-3-methylglutaryl-Coenzyme A reductase (HMGR), which catalyzes a reaction producing mevalonic acid, a key precursor of terpenoids such as membrane sterols and several types of hormones. The expression of HMGR gene increased within several hours after hypergravity treatment. Also, compactin, an inhibitor of HMGR, prevented hypergravity-induced growth suppression, suggesting that HMGR is involved in suppression of Arabidopsis hypocotyl growth by hypergravity. In addition, hypergravity increased the expression levels of genes encoding CCR1 and ERD15, which were shown to take part in the signaling pathway of environmental stimuli such as temperature and water, and those of the alpha-tubulin gene. These genes may be involved in a series of cellular events leading to growth suppression of stem organs under hypergravity conditions.

  6. Confined-Volume Effect on the Thermal Properties of Encapsulated Phase Change Materials for Thermal Energy Storage.

    Science.gov (United States)

    De Castro, Paula F; Ahmed, Adham; Shchukin, Dmitry G

    2016-03-18

    We have encapsulated the heat exchange material, n-docosane, into polyurethane capsules of different sizes. Decreasing the size of the capsules leads to changes of the crystallinity of phase-change material as well as melting/crystallization temperature. The novelty of the paper includes 1) protection of the nanostructured energy-enriched materials against environment during storage and controlled release of the encapsulated energy on demand and 2) study of the structure and surface-to-volume properties of the energy-enriched materials dispersed in capsules of different sizes. The stability of energy nanomaterials, influence of capsule diameter on their energy capacity, homogeneity and operation lifetime are investigated.

  7. The reversibility of CO2 induced climate change

    Science.gov (United States)

    Wu, Peili; Ridley, Jeff; Pardaens, Anne; Levine, Richard; Lowe, Jason

    2015-08-01

    This paper investigates the reversibility of CO2 induced climate change and in particular the potential impacts of different rates of CO2 reduction using a coupled climate model. Atmospheric CO2 concentration is ramped up by 0.5 %/year from the preindustrial value to 4×CO2 and then ramped down from 2×CO2 to 4×CO2 with different rates. How the response of the climate system is affected by the peak atmospheric CO2 concentration and the rate of long term decline is vital information for those considering hypothetical geoengineering options to remove CO2. Major components of the climate system including global mean surface air temperature and precipitation, contribution of thermal expansion to global sea level rise, loss of the Arctic sea ice, weakening of the Atlantic meridional overturning circulation (AMOC) and the South Asia monsoon are analyzed. We have found no `tipping points' or thresholds beyond which CO2 induced climate change in these components become irreversible within this model under the specific scenarios. However, there are strong inertias and path-dependent hysteresis in the climate system linked through oceanic memory. Initially the strengthened global hydrological cycle accelerates further in response to a CO2 ramp-down before weakening. Thermal expansion of the oceans continues for many decades after CO2 concentration starts to decrease. A 0.5 %/year reduction from 4×CO2 could see a further 25 % sea level rise. The weakening of the AMOC is reversible, but the build-up of highly saline subtropical waters during global warming drives an overshoot of the AMOC after the CO2 ramp-down and extends the warming of the northern high latitudes by many decades. The South Asia monsoon strengthens in response to a CO2 ramp-up marked by an increase in summer monsoon rainfall. This increase reverses rapidly following a CO2 ramp-down, displaying an undershoot in monsoon rainfall for rapid CO2 reductions.

  8. Impact of the volume change on the ageing effects in Cu-Al-Ni martensite: experiment and theory.

    Science.gov (United States)

    Kosogor, Anna; Xue, Dezhen; Zhou, Yumei; Ding, Xiangdong; Otsuka, Kazuhiro; L'vov, Victor A; Sun, Jun; Ren, Xiaobing

    2013-08-21

    The time evolution of the physical properties of martensite during martensite ageing is traditionally explained by the symmetry-conforming short-range order (SC-SRO) principle, which requires the spatial configuration of crystal defects to follow the symmetry change of the host lattice. In the present study, we show that the volume change of the host lattice also contributes to the ageing effects in Cu-Al-Ni shape memory alloy besides the symmetry change. To substantiate this statement the gradual increase of the storage modulus with time at constant temperature was measured by dynamic mechanical analysis (DMA) and the experimental results were quantitatively described in the framework of the symmetry-conforming Landau theory of martensitic transformations in a crystal with defects. The comparison of experimental and theoretical results confirmed that the time dependence of the storage modulus is caused by two different physical mechanisms. Evaluations showing that the first mechanism is driven by the spontaneous symmetry change and the second mechanism is caused by the volume change after the martensitic transformation was carried out.

  9. Glacial – interglacial atmospheric CO2 change: a possible "standing volume" effect on deep-ocean carbon sequestration

    Directory of Open Access Journals (Sweden)

    L. C. Skinner

    2009-05-01

    Full Text Available So far, the exploration of possible mechanisms for glacial atmospheric CO2 draw-down and marine carbon sequestration has focussed almost exclusively on dynamic or kinetic processes (i.e. variable mixing-, equilibration- or export rates. Here an attempt is made to underline instead the possible importance of changes in the standing volumes of intra-oceanic carbon reservoirs (i.e. different water-masses in setting the total marine carbon inventory. By way of illustration, a simple mechanism is proposed for enhancing the carbon storage capacity of the deep sea, which operates via an increase in the volume of relatively carbon-enriched AABW-like deep-water filling the ocean basins. Given the hypsometry of the ocean floor and an active biological pump, the water-mass that fills more than the bottom 3 km of the ocean will essentially determine the carbon content of the marine reservoir. A set of simple box-model experiments confirm the expectation that a deep sea dominated by AABW-like deep-water holds more CO2, prior to any additional changes in ocean overturning rate, biological export or ocean-atmosphere exchange. The magnitude of this "standing volume effect" might be as large as the contributions that have been attributed to carbonate compensation, the thermodynamic solubility pump or the biological pump for example. If incorporated into the list of factors that have contributed to marine carbon sequestration during past glaciations, this standing volume mechanism may help to reduce the amount of glacial – interglacial CO2 change that remains to be explained by other mechanisms that are difficult to assess in the geological archive, such as reduced mass transport or mixing rates in particular. This in turn could help narrow the search for forcing conditions capable of pushing the global carbon cycle between glacial and interglacial modes.

  10. Effects of Carperitide on Contrast-Induced Acute Kidney Injury with a Minimum Volume of Contrast in Chronic Kidney Disease Patients

    Directory of Open Access Journals (Sweden)

    Naoki Okumura

    2012-12-01

    Full Text Available Background/Aims: Although contrast-induced acute kidney injury (CIAKI is a major complication associated with angiography, the prophylaxis is not well established. Use of a low dose of carperitide for preventing CIAKI remains controversial. We examined the protective effect of carperitide on CIAKI after coronary angiography with a small contrast volume in chronic kidney disease (CKD patients with coronary artery disease. Methods: We randomly assigned 112 consecutive patients to a carperitide or a control group. The contrast volume was kept under 150 ml. The primary endpoint was the incidence of CIAKI defined by a serum creatinine of ≥25% or a serum creatinine of ≥0.5 mg/dl from baseline within 48 h. The secondary endpoint was a change in renal function at 1 week after the procedure. Results: The baseline characteristics and contrast volumes (carperitide group: 67.4 ± 38.2 ml vs. control group: 64.8 ± 20.5 ml, p = 0.661 were comparable in the two groups. The incidence of CIAKI was similar in the two groups (carperitide group: 8.5% vs. control group: 5.7%, p = 0.564. A multivariate analysis revealed that a hypotension ≥20 mm Hg was a significant predictor of developing CIAKI in the carperitide group (p = 0.015. The incidence of CIAKI in the carperitide group without hypotension was rare, but not significantly different (carperitide group: 2.4% vs. control group: 5.7%, p = 0.432. Conclusions: This study indicated that the use of a small contrast volume suppressed the incidence of CIAKI and that carperitide had no prophylactic effect against CIAKI. Our results also revealed the impact of hypotension on the development of CIAKI in the carperitide group.

  11. Hormone induced changes in lactase glycosylation in developing rat intestine.

    Science.gov (United States)

    Chaudhry, Kamaljit Kaur; Mahmood, Safrun; Mahmood, Akhtar

    2008-11-01

    Lactase exists in both soluble and membrane-bound forms in suckling rat intestine. The distribution of lactase and its glycosylated isoforms in response to thyroxine or cortisone administration has been studied in suckling rats. 75% of lactase activity was detected, associated with brush borders, compared to 24% in the soluble fraction of 8-day-old rats. Thyroxine treatment enhanced soluble lactase activity to 34%, whereas particulate fraction was reduced to 67% compared to controls. Cortisone administration reduced soluble lactase activity from 24% in controls to 12% with a concomitant increase in membrane-bound activity to 89%. Western blot analysis revealed lactase signal, corresponding to 220 kDa in both the soluble and membrane fractions, which corroborated the enzyme activity data. The elution pattern of papain solubilized lactase from agarose-Wheat Germ agglutinin, or Concanavalin A or Jacalin agglutinin columns was different in the suckling and adult rat intestines. Also the elution profile of lactase activity from agarose-lectin columns was modulated in cortisone, thyroxine, and insulin injected pups, which suggests differences in glycosylated isoforms of lactase under these conditions. These findings suggest the role of these hormones in inducing changes in lactase glycosylation during postnatal development of intestine, which may contribute to adult-type hypolactasia in rats.

  12. Cannabinoid-induced changes in respiration of brain mitochondria.

    Science.gov (United States)

    Fišar, Zdeněk; Singh, Namrata; Hroudová, Jana

    2014-11-18

    Cannabinoids exert various biological effects that are either receptor-mediated or independent of receptor signaling. Mitochondrial effects of cannabinoids were interpreted either as non-receptor-mediated alteration of mitochondrial membranes, or as indirect consequences of activation of plasma membrane type 1 cannabinoid receptors (CB1). Recently, CB1 receptors were confirmed to be localized to the membranes of neuronal mitochondria, where their activation directly regulates respiration and energy production. Here, we performed in-depth analysis of cannabinoid-induced changes of mitochondrial respiration using both an antagonist/inverse agonist of CB1 receptors, AM251 and the cannabinoid receptor agonists, Δ(9)-tetrahydrocannabinol (THC), cannabidiol, anandamide, and WIN 55,212-2. Relationships were determined between cannabinoid concentration and respiratory rate driven by substrates of complex I, II or IV in pig brain mitochondria. Either full or partial inhibition of respiratory rate was found for the tested drugs, with an IC50 in the micromolar range, which verified the significant role of non-receptor-mediated mechanism in inhibiting mitochondrial respiration. Effect of stepwise application of THC and AM251 evidenced protective role of AM251 and corroborated the participation of CB1 receptor activation in the inhibition of mitochondrial respiration. We proposed a model, which includes both receptor- and non-receptor-mediated mechanisms of cannabinoid action on mitochondrial respiration. This model explains both the inhibitory effect of cannabinoids and the protective effect of the CB1 receptor inverse agonist.

  13. VITAMIN CHANGES INDUCED BY X-RAY IN IRANIAN POTATOES

    Directory of Open Access Journals (Sweden)

    M. Azar

    1979-11-01

    Full Text Available The results of researches in the field of the using X-ray in all over the world have been successful. The main subject which needs more investigation and have been allocated part of the researches in most of the Atomic Research Institutes, is the research about possible harms of irradiated food for human beings, base on the researches, using irradiation for inhibition of sprouting and preservation of potato is recommended by the group members of scientist (IAEA in 1976, for developing countries which have faced food deficiency. (1 Regarding to ever-increasing of population in Iran, to prevent the food wastage a comprehensive study about production, harvesting and preservation of potato was carried out in 1976. (2 Following to that an irradiation experiment of potato for inhibiting of sprouting was carried out in Iran. (3 Then the vitamin changes in potato induced by X-ray were studied. In this experiment 60 gamma radiation doses of 10, 12 and 15 krad for two varieties of potatoes were tried. The tubers were monthly determined for the following: Ascorbic acid, Thiamin -and Riboflavin. The result of this experiment pre as follow: Different doses of gamma ray and preservation times are effective 0Ill the amount of potatoes vitamin C, and this effect in both cases would be a losses about 27 to 50%; also they are effective on the thiamin and, riboflavin content of potato. This effect causes losses less in-comparison with vitamin C.

  14. Ion Induced Changes in Phosphoinositide Monolayers at Phisiological Concentrations

    Science.gov (United States)

    Kazadi Badiambile, Adolphe; Forstner, Martin

    2013-03-01

    Phosphoinositides (PIPs) play a crucial role in many cellular process that occur at the plasma membrane such as calcium release, exocytosis or endocytosis. In order to specifically regulate these functions PIPs must segregate in pools at the plasma membrane. A possible mechanism that could induce and regulate such organization of phosphoinositides is their interaction with bivalent cations. Understanding the physicochemical mechanism that can regulate membrane structure is a crucial step in the development of adaptive biomimetic membrane systems. Using Langmuir monolayers, we investigated the effect of calcium and magnesium on the surface pressure-area/lipid isotherm of monolayer of phosphatidylinositol (PI), phosphatidylinositol bisphosphate (PIP2), dioleoylphosphatidylglycerol (DOPG) and palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC). It is found that the decrease of area per lipid, i.e. the increase in aggregation, is mostly dependent on the lipid's head group charge but ion specific. In addition, we discuss changes in free energy and compressibility of these monolayer-ion systems. NSF

  15. Gamma radiation induced changes in nuclear waste glass containing Eu

    Science.gov (United States)

    Mohapatra, M.; Kadam, R. M.; Mishra, R. K.; Kaushik, C. P.; Tomar, B. S.; Godbole, S. V.

    2011-10-01

    Gamma radiation induced changes were investigated in sodium-barium borosilicate glasses containing Eu. The glass composition was similar to that of nuclear waste glasses used for vitrifying Trombay research reactor nuclear waste at Bhabha Atomic Research Centre, India. Photoluminescence (PL) and electron paramagnetic resonance (EPR) techniques were used to study the speciation of the rare earth (RE) ion in the matrix before and after gamma irradiation. Judd-Ofelt ( J- O) analyses of the emission spectra were done before and after irradiation. The spin counting technique was employed to quantify the number of defect centres formed in the glass at the highest gamma dose studied. PL data suggested the stabilisation of the trivalent RE ion in the borosilicate glass matrix both before and after irradiation. It was also observed that, the RE ion distributes itself in two different environments in the irradiated glass. From the EPR data it was observed that, boron oxygen hole centre based radicals are the predominant defect centres produced in the glass after irradiation along with small amount of E’ centres. From the spin counting studies the concentration of defect centres in the glass was calculated to be 350 ppm at 900 kGy. This indicated the fact that bulk of the glass remained unaffected after gamma irradiation up to 900 kGy.

  16. Oxidative-stress-induced epigenetic changes in chronic diabetic complications.

    Science.gov (United States)

    Feng, Biao; Ruiz, Michael Anthony; Chakrabarti, Subrata

    2013-03-01

    Oxidative stress plays an important role in the development and progression of chronic diabetic complications. Diabetes causes mitochondrial superoxide overproduction in the endothelial cells of both large and small vessels. This increased superoxide production causes the activation of several signal pathways involved in the pathogenesis of chronic complications. In particular, endothelial cells are major targets of glucose-induced oxidative damage in the target organs. Oxidative stress activates cellular signaling pathways and transcription factors in endothelial cells including protein kinase C (PKC), c-Jun-N-terminal kinase (JNK), p38 mitogen-activated protein kinase (MAPK), forkhead box O (FOXO), and nuclear factor kappa-B (NF-κB). Oxidative stress also causes DNA damage and activates DNA nucleotide excision repair enzymes including the excision repair cross complimenting 1(ERCC1), ERCC4, and poly(ADP-ribose) polymerase (PARP). Augmented production of histone acetyltransferase p300, and alterations of histone deacetylases, including class III deacetylases sirtuins, are also involved in this process. Recent research has found that small noncoding RNAs, like microRNA, are a new kind of regulator associated with chronic diabetic complications. There are extensive and complicated interactions and among these molecules. The purpose of this review is to demonstrate the role of oxidative stress in the development of diabetic complications in relation to epigenetic changes such as acetylation and microRNA alterations.

  17. Reduced defense of central blood volume during acute lower body negative pressure-induced hypovolemic circulatory stress in aging women.

    Science.gov (United States)

    Lindenberger, Marcus; Länne, Toste

    2012-06-01

    Elderly humans are more vulnerable to trauma and hemorrhage than young and elderly men and respond with decreased defense of central blood volume during acute experimental hypovolemia induced by lower body negative pressure (LBNP). However, these defense mechanisms have not been evaluated in elderly women. The aim of this study was to determine the effectiveness of compensatory responses to defend central blood volume during experimental hypovolemia in elderly and young women. Cardiovascular responses in 34 women, 12 elderly (66 ± 1 years) and 22 young women (23 ± 0.4 years), were studied during experimental hypovolemia induced by LBNP of 11 to 44 mmHg. Air plethysmography was used to assess the capacitance response (redistribution of peripheral venous blood to the central circulation) as well as net capillary fluid transfer from tissue to blood in the arm. Lower body negative pressure seemed to create comparable hypovolemia measured as total calf volume increase in elderly and young women. Heart rate increased less in elderly women (LBNP of 44 mmHg: 20 ± 2 vs. 37 ± 4%; P < 0.01) but with similar (%) increase in forearm vascular resistance. Mobilization of capacitance blood from the peripheral circulation was both slower and decreased by ∼60% in elderly women (P < 0.001), and net capillary fluid absorption from surrounding tissues was reduced by ∼40% (P < 0.01, LBNP of 44 mmHg). Elderly women responded with less increase in heart rate but with equal forearm vascular resistance (%) response during LBNP. Furthermore, the compensatory capacitance response was both slower and substantially decreased, and net capillary fluid absorption considerably reduced, collectively indicating less efficiency to defend central blood volume in elderly than in young women.

  18. Stability, Tunneling and Flux Changing de Sitter Transitions in the Large Volume String Scenario

    CERN Document Server

    de Alwis, S; Hatefi, E; Quevedo, F

    2013-01-01

    We study the non-perturbative stability of the Large Volume Scenario (LVS) of IIB string compactifications, by analysing transitions mediated by the Brown-Teitelboim (BT) brane nucleations and by Coleman De Luccia tunneling (CDL). We find that, as long as the effective field theory description holds, the LVS AdS minima are stable despite being non-supersymmetric. This opens the possibility of having a CFT dual. Metastable de Sitter vacua behave differently depending on the uplifting mechanism. We find explicit expressions for the different decay rates in terms of exponentials of the volume. Among the transitions of dS to dS those with increasing volume and decreasing vacuum energy are preferred, though dS decays to AdS (big-crunch sinks) have higher probability. Transitions via the CDL mechanism to decompactification are exponentially suppressed compared to these. The BT decays correspond to flux/D3 brane transitions mediated by the nucleation of D5/NS5 branes. We compare our results with previous analysis fo...

  19. Thermally Induced Nano-Structural and Optical Changes of nc-Si:H Deposited by Hot-Wire CVD

    Directory of Open Access Journals (Sweden)

    Muller TFG

    2009-01-01

    Full Text Available Abstract We report on the thermally induced changes of the nano-structural and optical properties of hydrogenated nanocrystalline silicon in the temperature range 200–700 °C. The as-deposited sample has a high crystalline volume fraction of 53% with an average crystallite size of ~3.9 nm, where 66% of the total hydrogen is bonded as ≡Si–H monohydrides on the nano-crystallite surface. A growth in the native crystallite size and crystalline volume fraction occurs at annealing temperatures ≥400 °C, where hydrogen is initially removed from the crystallite grain boundaries followed by its removal from the amorphous network. The nucleation of smaller nano-crystallites at higher temperatures accounts for the enhanced porous structure and the increase in the optical band gap and average gap.

  20. Thermally Induced Nano-Structural and Optical Changes of nc-Si:H Deposited by Hot-Wire CVD.

    Science.gov (United States)

    Arendse, C J; Malgas, G F; Muller, T F G; Knoesen, D; Oliphant, C J; Motaung, D E; Halindintwali, S; Mwakikunga, B W

    2009-01-21

    We report on the thermally induced changes of the nano-structural and optical properties of hydrogenated nanocrystalline silicon in the temperature range 200-700 degrees C. The as-deposited sample has a high crystalline volume fraction of 53% with an average crystallite size of ~3.9 nm, where 66% of the total hydrogen is bonded as identical withSi-H monohydrides on the nano-crystallite surface. A growth in the native crystallite size and crystalline volume fraction occurs at annealing temperatures >/=400 degrees C, where hydrogen is initially removed from the crystallite grain boundaries followed by its removal from the amorphous network. The nucleation of smaller nano-crystallites at higher temperatures accounts for the enhanced porous structure and the increase in the optical band gap and average gap.

  1. Piroxicam-Induced hepatic and renal Histopathological changes in mice

    Directory of Open Access Journals (Sweden)

    Amany Tohamy

    2007-02-01

    Full Text Available Piroxicam is a non-steroidal anti-inflammatory drug widely used in rheumatic diseases. The aim of this study was to investigate Piroxicam-induced histopathological changes in livers and kidneys of male albino mice. Methods: Animals were classified into a control group and 4 treated groups. Piroxicam was injected intraperitoneally using 0.3 mg/kg every day for four weeks. Each week a group of mice was sacrificed. Liver and kidneys were obtained for histological and histochemical examination.Animals were classified into a control group and 4 treated groups. Piroxicam was injected intraperitoneally using 0.3 mg/kg every day for four weeks. Each week a group of mice was sacrificed. Liver and kidneys were obtained for histological and histochemical examination.Results: Liver sections appeared with inflammatory cellular infiltration, vacuolated hepatocytes, dilated sinusoids, and increased number of Kupffer cells. Kidney sections appeared with some cellular inflammations. The glomeruli were shrunk resulting in widening of the urinary space. Oedema and vacuolations were noticed in the tubular cells. There was a positive correlation between these pathological changes and the increased treatment periods. Histochemical staining revealed that glycogen and protein contents had decreased in the hepatocytes. This depletion worsened gradually in liver cells after two, three, and four weeks. Similar depletion of the glycogen content was observed in kidney tissue. However, protein content appeared to be slightly decreased in the kidney tubules and glomeruli. Incensement of coarse chromatin in the nuclei of hepatocytes, Kupffer cells and most inflammatory cells were detected by Fuelgen method. Kidney tissues appeared with a severe decrease in coarse chromatin in the nuclei.Liver sections appeared with inflammatory cellular infiltration, vacuolated hepatocytes, dilated sinusoids, and increased number of Kupffer cells. Kidney sections appeared with some cellular

  2. Evidence Report: Risk of Bone Fracture due to Spaceflight-Induced Changes to Bone

    Science.gov (United States)

    Sibonga, Jean D.; Evans, Harlan J.; Smith, Scott A.; Spector, Elisabeth R.; Yardley, Greg; Myer, Jerry

    2017-01-01

    Given that spaceflight may induce adverse changes in bone ultimate strength with respect to mechanical loads during and post-mission, there is a possibility a fracture may occur for activities otherwise unlikely to induce fracture prior to initiating spaceflight.

  3. Evidence for a multi-species coccolith volume change over the past two centuries: understanding a potential ocean acidification response

    Directory of Open Access Journals (Sweden)

    P. R. Halloran

    2008-12-01

    Full Text Available Major questions surround the species-specific nature of coccolithophore calcification in response to rising atmospheric CO2 levels. Here we present CaCO3 particle volume distribution data from the coccolith size-fraction of a rapidly accumulating North Atlantic sediment core. Without direct volume measurements on coccoliths produced by individual coccolithophore species, and knowledge of organic, as well as inorganic carbon production, it is not possible to state conclusively the coccolithophore calcification change at this site. However, by analysing the size distribution of CaCO3 particles in the less than 10 μm sediment fraction, we demonstrate a changing particle volume since the late 20th Century consistent with an increase in the mass of coccoliths produced by the larger coccolithophore species, and potentially a decrease in mass of coccoliths produced by the smaller species, present at this location. This finding has significant implications for the realistic representation of an assemblage-wide coccolithophore CO2-calcification response in numerical models.

  4. A MODEL TO ESTIMATE VOLUME CHANGE DUE TO RADIOLYTIC GAS BUBBLES AND THERMAL EXPANSION IN SOLUTION REACTORS

    Energy Technology Data Exchange (ETDEWEB)

    F. SOUTO; A HEGER

    2001-02-01

    Aqueous homogeneous solution reactors have been proposed for the production of medical isotopes. However, the reactivity effects of fuel solution volume change, due to formation of radiolytic gas bubbles and thermal expansion, have to be mitigated to allow steady-state operation of solution reactors. The results of the free run experiments analyzed indicate that the proposed model to estimate the void volume due to radiolytic gas bubbles and thermal expansion in solution reactors can accurately describe the observed behavior during the experiments. This void volume due to radiolytic gas bubbles and fuel solution thermal expansion can then be used in the investigation of reactivity effects in fissile solutions. In addition, these experiments confirm that the radiolytic gas bubbles are formed at a higher temperature than the fuel solution temperature. These experiments also indicate that the mole-weighted average for the radiolytic gas bubbles in uranyl fluoride solutions is about 1 {micro}m. Finally, it should be noted that another model, currently under development, would simulate the power behavior during the transient given the initial fuel solution level and density. The model is based on Monte Carlo simulation with the MCNP computer code [Briesmeister, 1997] to obtain the reactor reactivity as a function of the fuel solution density, which, in turn, changes due to thermal expansion and radiolytic gas bubble formation.

  5. Recording and Calculating Gunshot Sound—Change of the Volume in Reference to the Distance

    Science.gov (United States)

    Nikolaos, Tsiatis E.

    2010-01-01

    An experiment was conducted in an open practice ground (shooting range) regarding the recording of the sound of gunshots. Shots were fired using various types of firearms (seven pistols, five revolvers, two submachine guns, one rifle, and one shotgun) in different calibers, from several various distances with reference to the recording sources. Both, a conventional sound level meter (device) and a measurement microphone were used, having been placed in a fixed point behind the shooting line. The sound of each shot was recorded (from the device). At the same time the signal received by the microphone was transferred to a connected computer through an appropriate audio interface with a pre-amplifier. Each sound wave was stored and depicted as a wave function. After the physic-mathematical analysis of these depictions, the volume was calculated in the accepted engineering units(Decibels or dB) of Sound Pressure Level (SPL). The distances from the recording sources were 9.60 meters, 14.40 m, 19.20 m, and 38.40 m. The experiment was carried out by using the following calibers: .22 LR, 6.35 mm(.25 AUTO), 7.62 mm Tokarev(7,62×25), 7.65 mm(.32 AUTO), 9 mm Parabellum(9×19), 9 mm Short(9×17), 9 mm Makarov(9×18), .45 AUTO, .32 S&W, .38 S&W, .38 SPECIAL, .357 Magnum, 7,62 mm Kalashnikov(7,62×39) and 12 GA. Tables are given for the environmental conditions (temperature, humidity, altitude & barometric pressure), the length of the barrel of each gun, technical characteristics of the used ammunition, as well as for the volume taken from the SLM. The data for the sound intensity were collected after 168 gunshots (158 single shot & 10 bursts). According to the results, a decreasing of the volume, equivalent to the increasing of the distance, was remarked, as it was expected. Values seem to follow the Inverse square Law. For every doubling of the distance from the sound source, the sound intensity diminishes by 5.9904±0.2325 decibels (on average). In addition, we have the

  6. Effect of Climate Change on Service Life of High Volume Fly Ash Concrete Subjected to Carbonation—A Korean Case Study

    Directory of Open Access Journals (Sweden)

    Ki-Bong Park

    2017-01-01

    Full Text Available The increase in CO2 concentrations and global warming will increase the carbonation depth of concrete. Furthermore, temperature rise will increase the rate of corrosion of steel rebar after carbonation. On the other hand, compared with normal concrete, high volume fly ash (HVFA concrete is more vulnerable to carbonation-induced corrosion. Carbonation durability design with climate change is crucial to the rational use of HVFA concrete. This study presents a probabilistic approach that predicts the service life of HVFA concrete structures subjected to carbonation-induced corrosion resulting from increasing CO2 concentrations and temperatures. First, in the corrosion initiation stage, a hydration-carbonation integration model is used to evaluate the contents of the carbonatable material, porosity, and carbonation depth of HVFA concrete. The Monte Carlo method is adopted to determine the probability of corrosion initiation. Second, in the corrosion propagation stage, an updated model is proposed to evaluate the rate of corrosion, degree of corrosion for cover cracking of concrete, and probability of corrosion cracking. Third, the whole service life is determined considering both corrosion initiation stage and corrosion propagation stage. The analysis results show that climate change creates a significant impact on the service life of durable concrete.

  7. Activation of Na+/H+ and K+/H+ exchange by calyculin A in Amphiuma tridactylum red blood cells: implications for the control of volume-induced ion flux activity

    Science.gov (United States)

    Ortiz-Acevedo, Alejandro; Rigor, Robert R.; Maldonado, Hector M.; Cala, Peter M.

    2008-01-01

    Alteration in cell volume of vertebrates results in activation of volume-sensitive ion flux pathways. Fine control of the activity of these pathways enables cells to regulate volume following osmotic perturbation. Protein phosphorylation and dephosphorylation have been reported to play a crucial role in the control of volume-sensitive ion flux pathways. Exposing Amphiuma tridactylu red blood cells (RBCs) to phorbol esters in isotonic medium results in a simultaneous, dose-dependent activation of both Na+/H+ and K+/H+ exchangers. We tested the hypothesis that in Amphiuma RBCs, both shrinkage-induced Na+/H+ exchange and swelling-induced K+/H+ exchange are activated by phosphorylation-dependent reactions. To this end, we assessed the effect of calyculin A, a phosphatase inhibitor, on the activity of the aforementioned exchangers. We found that exposure of Amphiuma RBCs to calyculin-A in isotonic media results in simultaneous, 1–2 orders of magnitude increase in the activity of both K+/H+ and Na+/H+ exchangers. We also demonstrate that, in isotonic media, calyculin A-dependent increases in net Na+ uptake and K+ loss are a direct result of phosphatase inhibition and are not dependent on changes in cell volume. Whereas calyculin A exposure in the absence of volume changes results in stimulation of both the Na+/H+ and K+/H+ exchangers, superimposing cell swelling or shrinkage and calyculin A treatment results in selective activation of K+/H+ or Na+/H+ exchange, respectively. We conclude that kinase-dependent reactions are responsible for Na+/H+ and K+/H+ exchange activity, whereas undefined volume-dependent reactions confer specificity and coordinated control. PMID:18799654

  8. Changes and Significance of Matrix Metalloproteinase and Its Tissue Inhibitor in Plasma and Cardiac Muscle of Rats with Chronic Cardiac Failure Induced by Volume Overload%基质金属蛋白酶及其抑制物在容量过负荷致慢性心力衰竭大鼠血浆及心肌组织中的变化及意义

    Institute of Scientific and Technical Information of China (English)

    张超英; 李晓惠; 伏瑾; 崔小岱

    2011-01-01

    目的 观察容量过负荷致慢性心力衰竭大鼠血浆及心肌组织基质金属蛋白酶-8(MMP-8)及其抑制物-1(TIMP-1)的表达变化,探讨其在慢性心力衰竭发病中的病理生理作用.方法 雄性SD大鼠17只,随机分为分流组(n=9)和对照组(n=8).分流组通过腹主动脉下腔静脉穿刺术建立容量过负荷致慢性充血性心力衰竭动物模型,对照组大鼠除不做穿刺外,余操作过程同分流组.分别测定2组大鼠心功能及血流动力学指标,检测血浆MMP-8及TIMP-1水平,实时荧光定量PCR测定大鼠左心室、右心室MMP-8 mRNA、TIMP-1 mRNA的表达.结果 术后8周,分流组大鼠左心室收缩压、左心室舒张压、左心室内压差、左心室内压最大上升速率及最大下降速率较对照组明显降低(Pa<0.05,0.01);左心室舒张末压较对照组明显升高(P<0.05).分流组大鼠血浆MMP-8、TIMP-1水平均较对照组明显升高(Pa<0.05).与对照组相比,分流组大鼠左心室心肌组织MMP-8 mRNA及左、右心室心肌组织TIMP-1 mRNA水平均有升高趋势,右心室MMP-8 mRNA水平有下降趋势,但2组比较差异均无统计学意义(Pa>0.05);左心室和右心室心肌组织中MMP-8/TIMP-1明显降低,右心室较左心室下降更明显.结论 MMP-8与TIMP-1通过影响胶原代谢,参与容量过负荷致慢性充血性心力衰竭的病理生理过程.%Objective To observe the changes of matrix metalloproteinase - 8 ( MMP - 8 ) and its tissue inhibitors of metallopreteinase -1 ( TIMP - 1 ) in plasma and cardiac muscle of rats with chronic cardiac failure induced by volume overload, and to explore those roles in physiology of chronic cardiac failure. Methods Seventeen male SD rats were randomly divided into 2 groups as follows:9 shunt rat models were established by abdominal aorta and inferior vena cava shunt operation and 8 rats after sham operation served as controls. Hemodynamic and echocardiographic measurements were obtained 8 weeks

  9. Relative Importance of Aortic Stiffness and Volume as Predictors of Treatment-Induced Improvement in Left Ventricular Mass Index in Dialysis.

    Directory of Open Access Journals (Sweden)

    Panagiotis I Georgianos

    Full Text Available This study aimed to explore the relative contribution of aortic stiffness and volume in treatment-induced change of left ventricular mass in dialysis. Hypertension in Hemodialysis Patients Treated with Atenolol or Lisinopril trial compared the effect of lisinopril versus atenolol in reducing left ventricular mass index; 179 patients with echo measurements of aortic pulse wave velocity and left ventricular mass at baseline were included. In unadjusted analysis, overall reductions of 26.24 g/m2 (95% CI: -49.20, -3.29 and 35.67 g/m2 (95% CI: -63.70, -7.64 in left ventricular mass index were noted from baseline to 6 and 12 months respectively. Volume control emerged as an important determinant of regression of left ventricular mass index due to the following reasons: (i additional control for change in ambulatory systolic blood pressure mitigated the reduction in left ventricular mass index in the statistical model above [6-month visit: -18.6 g/m2 (95% CI: -43.7, 6.5; 12-month visit: -22.1 g/m2 (95% CI: -52.2, 8.0] (ii regression of left ventricular hypertrophy was primarily due to reduction in left ventricular chamber and not wall thickness and (iii adjustment for inferior vena cava diameter (as a proxy for volume removed the effect of time on left ventricular mass index reduction [6-month visit: -6.6 g/m2 (95% CI: (-41.6, 28.4; 12-month visit: 0.6 g/m2 (95% CI: -39.5, 40.7]. In contrast, aortic pulse wave velocity was neither a determinant of baseline left ventricular mass index nor predictor of its reduction. Among dialysis patients, ambulatory systolic pressure, a proxy for volume expansion, but not aortic stiffness is more important predictor of reduction in left ventricular mass index. Improving blood pressure control via adequate volume management appears as an effective strategy to improve left ventricular hypertrophy in dialysis.

  10. Exercise-Induced Fitness Changes Correlate with Changes in Neural Specificity in Older Adults

    Science.gov (United States)

    Kleemeyer, Maike M.; Polk, Thad A.; Schaefer, Sabine; Bodammer, Nils C.; Brechtel, Lars; Lindenberger, Ulman

    2017-01-01

    Neural specificity refers to the degree to which neural representations of different stimuli can be distinguished. Evidence suggests that neural specificity, operationally defined as stimulus-related differences in functional magnetic resonance imaging (fMRI) activation patterns, declines with advancing adult age, and that individual differences in neural specificity are associated with individual differences in fluid intelligence. A growing body of literature also suggests that regular physical activity may help preserve cognitive abilities in old age. Based on this literature, we hypothesized that exercise-induced improvements in fitness would be associated with greater neural specificity among older adults. A total of 52 adults aged 59–74 years were randomly assigned to one of two aerobic-fitness training regimens, which differed in intensity. Participants in both groups trained three times a week on stationary bicycles. In the low-intensity (LI) group, the resistance was kept constant at a low level (10 Watts). In the high-intensity (HI) group, the resistance depended on participants’ heart rate and therefore typically increased with increasing fitness. Before and after the 6-month training phase, participants took part in a functional MRI experiment in which they viewed pictures of faces and buildings. We used multivariate pattern analysis (MVPA) to estimate the distinctiveness of neural activation patterns in ventral visual cortex (VVC) evoked by face or building stimuli. Fitness was also assessed before and after training. In line with our hypothesis, training-induced changes in fitness were positively associated with changes in neural specificity. We conclude that physical activity may protect against age-related declines in neural specificity. PMID:28360850

  11. Finite volume analysis of temperature effects induced by active MRI implants: 2. Defects on active MRI implants causing hot spots

    Directory of Open Access Journals (Sweden)

    Grönemeyer Dietrich HW

    2006-05-01

    Full Text Available Abstract Background Active magnetic resonance imaging implants, for example stents, stent grafts or vena cava filters, are constructed as wireless inductively coupled transmit and receive coils. They are built as a resonator tuned to the Larmor frequency of a magnetic resonance system. The resonator can be added to or incorporated within the implant. This technology can counteract the shielding caused by eddy currents inside the metallic implant structure. This may allow getting diagnostic information of the implant lumen (in stent stenosis or thrombosis for example. The electro magnetic rf-pulses during magnetic resonance imaging induce a current in the circuit path of the resonator. A by material fatigue provoked partial rupture of the circuit path or a broken wire with touching surfaces can set up a relatively high resistance on a very short distance, which may behave as a point-like power source, a hot spot, inside the body part the resonator is implanted to. This local power loss inside a small volume can reach ¼ of the total power loss of the intact resonating circuit, which itself is proportional to the product of the resonator volume and the quality factor and depends as well from the orientation of the resonator with respect to the main magnetic field and the imaging sequence the resonator is exposed to. Methods First an analytical solution of a hot spot for thermal equilibrium is described. This analytical solution with a definite hot spot power loss represents the worst case scenario for thermal equilibrium inside a homogeneous medium without cooling effects. Starting with this worst case assumptions additional conditions are considered in a numerical simulation, which are more realistic and may make the results less critical. The analytical solution as well as the numerical simulations use the experimental experience of the maximum hot spot power loss of implanted resonators with a definite volume during magnetic resonance imaging

  12. Climate change induced risk analysis of Addis Ababa city (Ethiopia)

    Science.gov (United States)

    Jalayer, Fatemeh; Herslund, Lise; Cavan, Gina; Printz, Andreas; Simonis, Ingo; Bucchignani, Edoardo; Jean-Baptiste, Nathalie; Hellevik, Siri; Fekade, Rebka; Nebebe, Alemu; Woldegerima, Tekle; Workalemahu, Liku; Workneh, Abraham; Yonas, Nebyou; Abebe Bekele, Essete; Yeshitela, Kumelachew

    2013-04-01

    CLUVA (CLimate change and Urban Vulnerability in Africa; http://www.cluva.eu/) is a 3 years project, funded by the European Commission in 2010. Its objective is to develop context-centered methods to assess vulnerability and increase knowledge on managing climate related risks and to estimate the impacts of climate changes in the next 40 years at urban scale in Africa. The project downscales IPCC climate projections to evaluate threats to selected African test cities; mainly floods, sea-level rise, droughts, heat waves, desertification. It also evaluates and links: social vulnerability; urban green structures and ecosystem services; urban-rural interfaces; vulnerability of urban built environment and lifelines; and related institutional and governance dimensions of adaptation. CLUVA combines assessment approaches to investigate how cities, communities and households can resist and cope with, as well as recover from climate induced hazards. This multi-scale and multi-disciplinary qualitative, quantitative and probabilistic approach of CLUVA is currently being applied to selected African test cities (Addis Ababa - Ethiopia; Dar es Salaam - Tanzania; Douala - Cameroun; Ouagadougou - Burkina Faso; St. Louis - Senegal). In particular, the poster will report on the progresses of the Addis Ababa case study. Addis Ababa, the largest city in Ethiopia, is exposed to heat waves, drought, and, more recently, to flash floods. Due to undulating topography, poor waste management and the absence of sustainable storm water management, Addis Ababa is prone to severe flood events during the rainy seasons. Metropolitan Addis Ababa is crossed by several small watercourses. Torrential rains, very common during the rainy season, cause a sudden rise in the flow of these water courses, inundating and damaging the settlements along their banks and affecting the livelihood of the local population. The combination of climate change and development pressures are expected to exacerbate the

  13. Microgravity induced changes in the control of motor units

    Science.gov (United States)

    de Luca, C.; Roy, S.

    The goal of this project is to understand the effects of microgravity on the control of muscles. It is motivated by the notion that in order to adequately address microgravity-induced deterioration in the force generating capacity of muscles, one needs to understand the changes in the control aspects in addition to histochemical and morphological changes. The investigations into muscle control need to include the regulation of the firing activity of motor units that make up a muscle and the coordination of different muscles responsible for the control of a joint. In order to understand the effects of microgravity on these two aspects of muscle control, we will test astronauts before and after spaceflight. The investigations of the control of motor units will involve intramuscular EMG techniques developed in our laboratory. We will use a quadrifilar electrode to detect simultaneously three differential channels of EMG activity. These data will be decomposed accurately using a sophisticated set of algorithms constructed with artificial intelligence knowledge- based techniques. Particular attention will be paid to the firing rate and recruitment behavior of motor units and we will study the degree of cross-correlation of the firing rates. This approach will enable us to study the firing behavior of several (approx. 10) concurrently active motor units. This analysis will enable us to detect modifications in the control of motor units. We will perform these investigations in a hand muscle, which continues being used in prehensile tasks in space, and a leg muscle whose antigravity role is not needed in space. The comparison of the effects of weightlessness on these muscles will determine if continued use of muscles in space deters the possible deleterious effects of microgravity on the control of motor units, in addition to slowing down atrophy. We are particularly interested in comparing the results of this study to similar data already obtained from elderly subjects

  14. Changes in size and shape of auditory hair cells in vivo during noise-induced temporary threshold shift.

    Science.gov (United States)

    Dew, L A; Owen, R G; Mulroy, M J

    1993-03-01

    In this study we describe changes in the size and shape of auditory hair cells of the alligator lizard in vivo during noise-induced temporary threshold shift. These changes consist of a decrease in cell volume, a decrease in cell length and an increase in cell width. We speculate that these changes are due to relaxation of cytoskeletal contractile elements and osmotic loss of intracellular water. We also describe a decrease in the surface area of the hair cell plasmalemma, and speculate that it is related to the endocytosis and intracellular accumulation of cell membrane during synaptic vesicle recycling. Finally we describe an increase in the endolymphatic surface area of the hair cell, and speculate that this could alter the micromechanics of the stereociliary tuft to attenuate the effective stimulus.

  15. Pregnancy-induced changes in breast cancer risk.

    Science.gov (United States)

    Russo, Irma H; Russo, Jose

    2011-09-01

    Breast cancer is the malignant disease most frequently diagnosed in women of all races and nationalities. Since the 1970s the worldwide incidence of this disease has increased 30-40% in postmenopausal women, in whom, paradoxically, the risk of developing breast cancer is significantly reduced by an early first full term pregnancy (FTP) as compared to nulliparous and late parous women. Although the cause of breast cancer is not known, the mechanisms mediating the protection conferred by an early FTP have been identified to reside in the breast itself, and to be modulated by endogenous and environmental exposures that might negatively affect this organ during specific windows in its development that extend from prenatal life until the first pregnancy. Soon after conception the embryo initiates the production of human chorionic gonadotropin (hCG), the glycoprotein hormone that is diagnostic of pregnancy. HCG in conjunction with ovarian steroid hormones primes the hypothalamic neuroendocrine system for maintaining the pregnancy. Higher levels of hCG during the first trimester of pregnancy have been associated with a reduction in maternal breast cancer incidence after age 50. In preclinical studies it has been demonstrated that both FTP and hCG treatment of virgin rats prevent the development of chemically-induced mammary tumors, a phenomenon mediated by the differentiation of the mammary gland epithelial cells prior to carcinogen exposure. Complete differentiation proceeds through complex morphological, physiological and molecular changes that occur during pregnancy and lactation, that ultimately result in increased DNA repair capabilities of the mammary epithelium, activation of genes controlling differentiation and programmed cell death and imprinting in the breast epithelium a specific and permanent genomic signature of pregnancy. This signature is indicative of a reduced breast cancer risk and serves as a molecular biomarker of differentiation for evaluating the

  16. Glue embolization of the giant aneurysm by reducing thrombosis-induced volume expansion effect

    Energy Technology Data Exchange (ETDEWEB)

    Yeom, Yoo Kyung; Suh, Dae Chul [Dept. of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of)

    2015-04-15

    A giant aneurysm due to a large intra-aneurysmal volume can be complicated by a delayed massive volume expansion caused by thrombus formation. To prevent such a severe mass effect, we obliterated the aneurysmal lumen by gluing and prevented further development of thrombosis. A 52-year-old female with a giant aneurysm at the cavernous segment of the internal carotid artery presented with tinnitus and intermittent diplopia. After confirming with a negative occlusion test, the right internal carotid artery was trapped by coiling and with further obliteration of the aneurysmal lumen by gluing. She developed a mild diplopia after the procedure and recovered without any deficit. The magnetic resonance angiography showed a stable occlusion of the aneurysm and good collateral filling of the cerebral vessel 15 months later.

  17. Pulmonary Edema and Plasma Volume Changes in Dysbarism. M.S. Thesis - Texas Univ.

    Science.gov (United States)

    Joki, J. A.

    1972-01-01

    Two groups of anesthetized, fasted pigs were utilized. One group of 13 animals (8.5 to 16.6 kilograms) was exposed to a high-pressure environment, and the other group of eight animals (6.9 to 20.0 kilograms) constituted the control group. The experimental group was subjected to an atmosphere of 90 percent nitrogen and 10 percent oxygen at a pressure of 50 psig for 30 minutes and then decompressed at a rate 10 psi/min. Plasma volumes, using both iodine-125-tagged-albumin and chromium-51-tagged-cell dilution techniques, were measured before, immediately after, and at 30 and 60 minutes after decompression. Aortic and right-ventricular systolic pressures were also recorded. At 60 minutes after decompression, blood samples were taken, the animals were sacrificed, and the water content of the lungs, kidneys, livers, and spleens was estimated by measuring tissue wet weight and dry weight. Protein extravasation and tissue blood volumes were determined by measuring the iodine-125-tagged-albumin and chromium-51-tagged-cell spaces in homo-genates of the organs under investigation.

  18. TRAINING-LEVEL INDUCED CHANGES IN BLOOD PARAMETERS RESPONSE TO ON-WATER ROWING RACES

    Directory of Open Access Journals (Sweden)

    Cyril Petibois

    2008-12-01

    Full Text Available The study investigated blood markers allowing discriminating physiological responses to on-water rowing races, notably regarding training volume of athletes and race duration. College (COL and national (NAT rowers performed a 1000- or 2000-m race. Capillary blood samples obtained before and post-race allowed an analysis of a wide range of serum parameters. COL rowers had a lower rowing experience and training volume than NAT. Races induced a higher lactate concentration increase in NAT compared to COL (10.45 ± 0.45 vs 13.05 ± 0.60; p < 0.001. Race distance (2000 vs. 1000 m induced a higher increase in fatty acids (0.81 ± 0.31 vs +0.67 ± 0. 41; p < 0.05 and triglycerides concentration in NAT (0.33 ± 0.07 vs 0.15 ± 0.09; p < 0.01, but remained comparable between NAT and COL for the 1000-m races. Amino acids concentrations increased in NAT (0.19 ± 0.03, p < 0.01, but urea concentration increased only for NAT rowers having performed the 2000-m race (0.72 ± 0.22, p < 0.05. Transferrin concentration decreased after the 2000-m race (-0.60 ± 0.25, p < 0.05, and concentration changes of haptoglobin differed between NAT2000 (tendency to be reduced and COL (tendency to by enhanced (p < 0.05. Our results confirmed that the training level in rowing is associated with higher glycolysis utilization during maximal 1000- and 2000-m exercise and no difference for similarly trained subjects at these two distances. Our study also demonstrated that a 2000-m race could initiate fatty and amino-acid metabolisms in highly trained subjects. Therefore, these changes in blood parameter responses to a characteristic rowing exercise highlighted the importance of monitoring the physiological effects of training in sporting conditions and according to individual characteristics

  19. Quantifying seasonal volume of groundwater in high elevation meadows: Implications for complex aquifer geometry in a changing climate

    Science.gov (United States)

    Ciruzzi, Dominick M.

    The hydrologic impacts of rising global temperatures are severe and imminent particularly in snow-dominated regions. In the western United States, high elevation meadows are among the ecosystems highly sensitive to climate change. High elevation meadows are groundwater dependent ecosystems and rely on seasonal snowpack melt in order to support ecologic function and baseflow to streams. This stream flow in turn supplies an estimated 2.6 million San Francisco residents with water. Once the snow melts and recharges the aquifer, groundwater supports vegetation separate from the surrounding hillslopes, which promotes important ecologic functions like flood regulation and nutrient cycling. Groundwater also supports baseflow to perennial rivers late into the summer months transferring this snowmelt to downstream ecologic and human communities. By 2100 snowpack accumulation in the Sierra Nevada is expected to decrease by ~40-90% due to near-surface temperature rise. Though precipitation intensity is not expected to change, a decrease in snowpack will change the timing and magnitude of groundwater recharge necessary to sustain high elevation meadows. An additional climate-driven shift and decrease in peak stream flow to early spring away from summer when demand is highest puts into question ecosystem survivability and water supply to downstream users. Here, a new quantitative framework is presented to lay the foundation for the widespread identification of vulnerabilities in high elevation meadows due to climate change. This research proposed and tested a new conceptual model for the volume of groundwater stored in high elevation meadows similar to that of a reservoir with active and dead storage. The seasonal fluctuations in active storage, which is defined as the volume of groundwater able to exchange between the aquifer, streams, and vegetation, are thought to be highly sensitive to aquifer parameters, such as bedrock geometry, meadow gradient, and hydraulic conductivity

  20. Local and global volume changes of subcortical brain structures from longitudinally varying neuroimaging data for dementia identification.

    Science.gov (United States)

    Unay, Devrim

    2012-09-01

    Quantification of structural changes in the human brain is important to elicit resemblances and differences between pathological and normal aging. Identification of dementia, associated with loss of cognitive ability beyond normal aging, and especially converters--the subgroup of individuals at risk for developing dementia--has recently gained importance. For this purpose atrophy markers have been explored and their effectiveness has been evaluated both cross-sectionally and longitudinally. However, more research is needed to understand the dynamics of atrophy markers at different disease stages, which requires temporal analysis of local along with global changes. Unfortunately, most of the longitudinal neuroimaging data available in the clinical settings is acquired at largely varying time intervals. In the light of the above, this study presents a novel methodology to process longitudinal neuroimaging data acquired incompletely and at different time intervals, and explores complementary nature of local and global brain volume changes in identifying dementia. Results on the OASIS database demonstrate discriminative power of global atrophy in hippocampus (as early as two years after the first visit) for identifying demented cases, and local volume shrinkage of thalamus proper (as early as three years after the first visit) for differentiating converters.

  1. Effect of change in blood volume in skin plus active muscle on heart rate drift during submaximal exercise

    OpenAIRE

    Yano,T.; T Yunoki; Matsuura, R.; Arimitsu, T.; Kimura, T.

    2008-01-01

    The purpose of the present study was to examine the effect of change in blood volume in skin plus active muscle on heart rate drift during moderate exercise and heavy exercise for 30 min. Total hemoglobin concentration (Total Hb) in the vastus lateralis muscle plus its skin was determined by near-infrared spectroscopy. Total Hb significantly increased and remained stable from 20 min in moderate exercise and from 10 min in heavy exercise. Heart rate (HR) rapidly increased until 3 min and showe...

  2. Local control of emission energy of semiconductor quantum dots using volume expansion of a phase-change material

    Science.gov (United States)

    Takahashi, Motoki; Syafawati Humam, Nurrul; Tsumori, Nobuhiro; Saiki, Toshiharu; Regreny, Philippe; Gendry, Michel

    2013-03-01

    A method is proposed to precisely control the emission energy of semiconductor quantum dots (QDs) by the application of local strain due to volume expansion of a phase-change material (GeSbTe) upon amorphization. The feasibility of the method is experimentally demonstrated using photoluminescence (PL) spectroscopy of single InAs/InP QDs on which a GeSbTe thin film is deposited. A significant red-shift of the PL peak energy upon amorphization and subsequent recovery by recrystallization with laser annealing were observed.

  3. A model to estimate volume change due to radiolytic gas bubbles and thermal expansion in solution reactors

    Energy Technology Data Exchange (ETDEWEB)

    Souto, F.J. [NIS-6: Advanced Nuclear Technology, Los Alamos National Lab., Los Alamos, NM (United States); Heger, A.S. [ESA-EA: Engineering Sciences and Application, Los Alamos National Lab., Los Alamos, NM (United States)

    2001-07-01

    To investigate the effects of radiolytic gas bubbles and thermal expansion on the steady-state operation of solution reactors at the power level required for the production of medical isotopes, a calculational model has been developed. To validate this model, including its principal hypotheses, specific experiments at the Los Alamos National Laboratory SHEBA uranyl fluoride solution reactor were conducted. The following sections describe radiolytic gas generation in solution reactors, the equations to estimate the fuel solution volume change due to radiolytic gas bubbles and thermal expansion, the experiments conducted at SHEBA, and the comparison of experimental results and model calculations. (author)

  4. Indication of BOLD-specific venous flow-volume changes from precisely controlled hyperoxic vs. hypercapnic calibration.

    Science.gov (United States)

    Mark, Clarisse I; Pike, G Bruce

    2012-04-01

    Deriving cerebral metabolic rate of oxygen consumption (CMRO(2)) from blood oxygenation level-dependent (BOLD) signals involves a flow-volume parameter (α), reflecting total cerebral blood volume changes, and a calibration constant (M). Traditionally, the former is assumed a fixed value and the latter is measured under alterations in fixed inspired fractional concentrations of carbon dioxide. We recently reported on reductions in M-variability via precise control of end-tidal pressures of both hypercapnic (HC) and hyperoxic (HO) gases. In light of these findings, our aim was to apply the improved calibration alternatives to neuronal activation, making use of their distinct vasoactive natures to evaluate the α-value. Nine healthy volunteers were imaged at 3 T while simultaneously measuring BOLD and arterial spin-labeling signals during controlled, graded, HC, and HO, followed by visual (VC) and sensorimotor cortices (SMC) activation. On the basis of low M- and CMRO(2)-variability, the comparison of these calibration alternatives accurately highlighted a reduced venous flow-volume relationship (α=0.16±0.02, with α(VC)=0.12±0.04, and α(SMC)=0.20±0.02), as appropriate for BOLD modeling.

  5. Morphologic Changes of Mammary Carcinomas in Mice over Time as Monitored by Flat-Panel Detector Volume Computed Tomography

    Directory of Open Access Journals (Sweden)

    Jeannine Missbach-Guentner

    2008-07-01

    Full Text Available Noninvasive methods are strongly needed to detect and quantify not only tumor growth in murine tumor models but also the development of vascularization and necrosis within tumors. This study investigates the use of a new imaging technique, flat-panel detector volume computed tomography (fpVCT, to monitor in vivo tumor progression and structural changes within tumors of two murine carcinoma models. After tumor cell inoculation, single fpVCT scans of the entire mice were performed at different time points. The acquired isotropic, high-resolution volume data sets enable an accurate real-time assessment and precise measurements of tumor volumes. Spreading of contrast agent-containing blood vessels around and within the tumors was clearly visible over time. Furthermore, fpVCT permits the identification of differences in the uptake of contrast media within tumors, thus delineating necrosis, tumor tissues, and blood vessels. Classification of tumor tissues based on the decomposition of the underlying mixture distribution of tissue-related Hounsfield units allowed the quantitative acquisition of necrotic tissues at each time point. Morphologic alterations of the tumor depicted by fpVCT were confirmed by histopathologic examination. Concluding, our data show that fpVCT may be highly suitable for the noninvasive evaluation of tumor responses to anticancer therapies during the course of the disease.

  6. Northward advection of Atlantic water in the eastern Nordic Seas over the last 3000 yr: a coccolith investigation of volume transport and surface water changes

    Directory of Open Access Journals (Sweden)

    C. V. Dylmer

    2013-03-01

    Full Text Available Three marine sediment cores distributed along the Norwegian (MD95-2011, Barents Sea (JM09-KA11-GC, and Svalbard (HH11-134-BC continental margins have been investigated in order to reconstruct changes in the poleward flow of Atlantic Waters (AW and in the nature of upper surface water masses within the eastern Nordic Seas over the last 3000 yr. These reconstructions are based on a limited set of coccolith proxies: the abundance ratio between Emiliania huxleyi and Coccolithus pelagicus, an index of Atlantic vs. Polar-Arctic surface water masses; and Gephyrocapsa muellerae, a drifted coccolith species from the temperate North Atlantic, whose abundance changes are related to variations in the volume transport of the North Atlantic Current and its northernmost extension (the West Spitsbergen Current – WSC off western Svalbard. The entire investigated area, from 66 to 77° N, was affected by an overall increase in volume flow of AW from 3000 cal yr BP to Present. The long-term modulation of westerlies strength and location which are essentially driven by the dominant mode of the North Atlantic Oscillation (NAO, is thought to explain the observed dynamics of poleward AW flow. The same mechanism also reconciles the recorded opposite zonal shifts in the location of the Arctic Front between the area off western Norway and the Barents Sea-eastern Fram Strait region. The Little Ice Age was governed by deteriorating conditions, with Arctic/Polar waters dominating in the surface off western Svalbard and western Barents Sea, possibly associated with both severe sea-ice conditions and a strongly reduced AW volume flow. A sudden short pulse of resumed high WSC flow interrupted this cold spell in eastern Fram Strait from 330 to 410 cal yr BP, with a a magnitude only surpassed by the one which characterizes the Modern Period. Our dataset not only confirms the high amplitude warming of surface waters at the turn of the 19th century off western Svalbard, it also

  7. Volume Change of Heterogeneous Quasi-brittle Materials in Uniaxial Compression

    Institute of Scientific and Technical Information of China (English)

    WANG Xuebin

    2006-01-01

    The volumetric strain was categorized into elastic and plastic parts. The former composed of axial and lateral strains is uniform and determined by Hooke's law; however, the latter consisting of axial and lateral strains is a function of thickness of shear band determined by gradient-dependent plasticity by considering the heterogeneity of quasi-brittle materials. The non-uniform lateral strain due to the fact that shear band was formed in the middle of specimen was averaged within specimen to precisely assess the volumetric strain. Then, the analytical expression for volumetric strain was verified by comparison with two earlier experimental results for concrete and rock. Finally, a detailed parametric study was carried out to investigate effects of constitutive parameters (shear band thickness, elastic and softening moduli) and geometrical size of specimen(height and width of specimen) on the volume dilatancy.

  8. Changes in the determinants of induced abortion in Korea.

    Science.gov (United States)

    Cho, N H; Ahn, N

    1993-12-01

    Study results suggested that Korea's family planning program must shift to the promotion of a balanced sex ratio and prevention of induced abortion. The abortion rate increased markedly until the mid-1980s and then stabilized. The number of abortions almost equalled the number of live births. Retrospective data from the 1991 National Fertility and Family Health Survey of Korea were used to examine the determinants of pregnancy outcomes. The sample included 8475 pregnancies at parity 0, 7947 at parity 1, 5358 at parity 2, and 3437 at parity 3 or higher. An interesting finding was that families with 2 girls reported a very high number of spontaneous abortions since 1985: over 10% (41/389). The number of spontaneous abortions among families with 1-2 male children was only 3% (22/718). Among childless parents only 27% of pregnancies were aborted, while among one-child families 46% were aborted and among two-child families 81% were aborted. From before 1975 until after 1985, abortions among childless parents increased from 10% to 30%. This increase was accounted for by the increased number of premarital pregnancies, which were greater among middle and high school graduates. The abortion rate was high for pregnancies occurring at least 8 months before marriage and for pregnancies of more highly educated recent cohorts occurring earlier than 7 months before marriage. The probability of abortion was 3% for cohorts prior to 1974 with one son and 9% for the recent cohort (1985 and later). This shift may reflect a changed preference for smaller families and son preference. About 40% of pregnancies resulted in a live birth among families with 2 daughters in the most recent cohort. The probability of abortion was 33% higher among families with 2 boys in the earliest cohort than families without a son. The effect of education on pregnancy outcome varied with parity and time period. The abortion rate was higher among educated women, which meant less effective contraceptive

  9. Gas volume contents within a container, smart volume instrument

    Science.gov (United States)

    Kelley, Anthony R. (Inventor); Van Buskirk, Paul D. (Inventor)

    2008-01-01

    A method for determining the volume of an incompressible gas in a system including incompressible substances in a zero-gravity environment. The method includes inducing a volumetric displacement within a container and measuring the resulting pressure change. From this data, the liquid level can be determined.

  10. Are There Linguistic Prerequisites for Contact-Induced Language Change?

    Science.gov (United States)

    Thomason, Sarah Grey

    Observation of language change caused by language contact tend not to support theories put forth by Meillet, Jakobson, Weinreich, and others that there are linguistic prerequisites for such change. A theory of the social factors that determine what kinds of language change will take place as a result of contact begins with the recognition of two…

  11. Are There Linguistic Prerequisites for Contact-Induced Language Change?

    Science.gov (United States)

    Thomason, Sarah Grey

    Observation of language change caused by language contact tend not to support theories put forth by Meillet, Jakobson, Weinreich, and others that there are linguistic prerequisites for such change. A theory of the social factors that determine what kinds of language change will take place as a result of contact begins with the recognition of two…

  12. Longitudinal micro-CT provides biomarkers of lung disease that can be used to assess the effect of therapy in preclinical mouse models, and reveal compensatory changes in lung volume.

    Science.gov (United States)

    Vande Velde, Greetje; Poelmans, Jennifer; De Langhe, Ellen; Hillen, Amy; Vanoirbeek, Jeroen; Himmelreich, Uwe; Lories, Rik J

    2016-01-01

    In vivo lung micro-computed tomography (micro-CT) is being increasingly embraced in pulmonary research because it provides longitudinal information on dynamic disease processes in a field in which ex vivo assessment of experimental disease models is still the gold standard. To optimize the quantitative monitoring of progression and therapy of lung diseases, we evaluated longitudinal changes in four different micro-CT-derived biomarkers [aerated lung volume, lung tissue (including lesions) volume, total lung volume and mean lung density], describing normal development, lung infections, inflammation, fibrosis and therapy. Free-breathing mice underwent micro-CT before and repeatedly after induction of lung disease (bleomycin-induced fibrosis, invasive pulmonary aspergillosis, pulmonary cryptococcosis) and therapy (imatinib). The four lung biomarkers were quantified. After the last time point, we performed pulmonary function tests and isolated the lungs for histology. None of the biomarkers remained stable during longitudinal follow-up of adult healthy mouse lungs, implying that biomarkers should be compared with age-matched controls upon intervention. Early inflammation and progressive fibrosis led to a substantial increase in total lung volume, which affects the interpretation of aerated lung volume, tissue volume and mean lung density measures. Upon treatment of fibrotic lung disease, the improvement in aerated lung volume and function was not accompanied by a normalization of the increased total lung volume. Significantly enlarged lungs were also present in models of rapidly and slowly progressing lung infections. The data suggest that total lung volume changes could partly reflect a compensatory mechanism that occurs during disease progression in mice. Our findings underscore the importance of quantifying total lung volume in addition to aerated lung or lesion volumes to accurately document growth and potential compensatory mechanisms in mouse models of lung

  13. Osmosis-induced water uptake by Eurobitum bituminized radioactive waste and pressure development in constant volume conditions

    Science.gov (United States)

    Mariën, A.; Mokni, N.; Valcke, E.; Olivella, S.; Smets, S.; Li, X.

    2013-01-01

    The chemo-hydro-mechanical (CHM) interaction between swelling Eurobitum radioactive bituminized waste (BW) and Boom Clay is investigated to assess the feasibility of geological disposal for the long-term management of this waste. These so-called compatibility studies include laboratory water uptake tests at the Belgian Nuclear Research Center SCK•CEN, and the development of a coupled CHM formulation for Eurobitum by the International Center for Numerical Methods and Engineering (CIMNE, Polytechnical University of Cataluña, Spain). In the water uptake tests, the osmosis-induced swelling, pressure increase and NaNO3 leaching of small cylindrical BW samples (diameter 38 mm, height 10 mm) is studied under constant total stress conditions and nearly constant volume conditions; the actual geological disposal conditions should be intermediate between these extremes. Two nearly constant volume tests were stopped after 1036 and 1555 days to characterize the morphology of the hydrated BW samples and to visualize the hydrated part with microfocus X-ray Computer Tomography (μCT) and Environmental Scanning Electron Microscopy (ESEM). In parallel, a coupled CHM formulation is developed that describes chemically and hydraulically coupled flow processes in porous materials with salt crystals, and that incorporates a porosity dependent membrane efficiency, permeability and diffusivity. When Eurobitum BW is hydrated in (nearly) constant volume conditions, the osmosis-induced water uptake results in an increasing pressure to values that can be (in theory) as high as 42.8 MPa, being the osmotic pressure of a saturated NaNO3 solution. After about four years of hydration in nearly constant volume water uptake tests, pressures up to 20 MPa are measured. During this hydration period only the outer layers with a thickness of 1-2 mm were hydrated (as derived from μCT and ESEM analyses), and only about 10-20% of the initial NaNO3 content was released by the samples. In the studied test

  14. RADIATION DOSE–VOLUME EFFECTS IN RADIATION-INDUCED RECTAL INJURY

    Science.gov (United States)

    Michalski, Jeff M.; Gay, Hiram; Jackson, Andrew; Tucker, Susan L.; Deasy, Joseph O.

    2010-01-01

    The available dose/volume/outcome data for rectal injury were reviewed. The volume of rectum receiving ≥60Gy is consistently associated with the risk of Grade ≥2 rectal toxicity or rectal bleeding. Parameters for the Lyman-Kutcher-Burman normal tissue complication probability model from four clinical series are remarkably consistent, suggesting that high doses are predominant in determining the risk of toxicity. The best overall estimates (95% confidence interval) of the Lyman-Kutcher-Burman model parameters are n = 0.09 (0.04–0.14); m = 0.13 (0.10–0.17); and TD50 = 76.9 (73.7–80.1) Gy. Most of the models of late radiation toxicity come from three-dimensional conformal radiotherapy dose-escalation studies of early-stage prostate cancer. It is possible that intensity-modulated radiotherapy or proton beam dose distributions require modification of these models because of the inherent differences in low and intermediate dose distributions. PMID:20171506

  15. Changes in the arteriolar volume pulse of the finger during various degrees of tilt using near infra-red and red photoplethysmography.

    Science.gov (United States)

    Christ, F; Nehring, I; Abicht, J; Baranov, V; Kotov, A; Gartside, I; Gamble, J; Messmer, K

    1998-05-12

    1. Photoplethysmography is a widely used non invasive technique for the measurement of peripheral oxygen saturation. A more detailed analysis of the volume pulse (VP) can indicate alterations in peripheral vascular tone, due to sympathetic stimulation, stress, pain and temperature. - 2. In six healthy male volunteers we investigated changes in the VP resulting from vasoconstriction and vasodilatation induced by varies degrees of tilt. Subjects were subjected 0 degrees tilt followed by head down -8 degrees -15 degrees, -30 degrees -15 degrees, -8 degrees, 0 degrees, 15 degrees, 30 degrees , 70 degrees, 30 degrees, 15 degrees and 0 degrees. Each tilt stage was sustained for 15 minutes. Both VP - and haemodynamic changes were continuously recorded 30s before and then for 210 s after the imposition of each tilt step. We used a new computer driven soft and hardware for the analysis of the VP. 3. The VP signal was obtained with a sensor emitting 840 nm (NIR) and 640 nm (RED) light into finger tip with a sample rate of 128 Hz. All data was normalised to the initial mean value obtained at 0 degrees tilt. The signal strength parameters amplitude, and area under the curve and the first derivative of the amplitude (flux) as well as time discrete parameters, time of first maximum (Tmax), dicrote wave (Td), volume pulse decrease (Tdec) and fundamental arterial oscillation Tag = Td - Tmax were measured. 4. HR increased significantly during 30 degrees and 70 degrees tilt, but no change in the other hemodynamic parameters was observed. Amplitude, area under the curve and flux of both the Red and the NIR signal increased following head down tilt. A significant decrease of those parameters was found during foot down tilt. 5. No significant changes were found in the time discrete values, neither within each tilt step nor when compared to the initial mean value at 0 degrees tilt. 6. This study reveals that signal strength related parameters such as area under the curve, amplitude and

  16. Composition-volume changes during hydrothermal alteration of andesite at Buttercup Hill, Noranda District, Quebec

    Science.gov (United States)

    Lesher, C. M.; Gibson, H. L.; Campbell, I. H.

    1986-12-01

    hydrothermal modification of the andesite. Mass balance calculations suggest that volume was conserved during epidotization-silicification and albitization-silicification, but that intense silicification was accompanied by volume increases up to 30 percent.

  17. The effect of strain path change on subgrain volume fraction determined from in situ X-ray measurements

    DEFF Research Database (Denmark)

    Wejdemann, Christian; Poulsen, Henning Friis; Lienert, U.

    2009-01-01

    The evolution of dislocation structures in individual bulk grains in copper during strain path changes is studied with a new in situ synchrotron technique which combines high angular resolution with fast three-dimensional reciprocal space mapping. Deformed copper contains regions with vanishing...... dislocation density called subgrains bounded by dislocation rich walls. With the new technique reciprocal space maps, consisting of sharp peaks arising from the subgrains superimposed on a cloud of lower intensity arising from the dislocation walls, are obtained, which allows properties such as subgrain...... volume fraction to be quantified. The studied strain path changes are tension-tension sequences. Polycrystalline copper sheets are pre-deformed in tension to 5% strain, and tensile samples are cut with varying angles between the first and second loading axis. The second tensile deformation up...

  18. Detection of atomic scale changes in the free volume void size of three-dimensional colorectal cancer cell culture using positron annihilation lifetime spectroscopy.

    Science.gov (United States)

    Axpe, Eneko; Lopez-Euba, Tamara; Castellanos-Rubio, Ainara; Merida, David; Garcia, Jose Angel; Plaza-Izurieta, Leticia; Fernandez-Jimenez, Nora; Plazaola, Fernando; Bilbao, Jose Ramon

    2014-01-01

    Positron annihilation lifetime spectroscopy (PALS) provides a direct measurement of the free volume void sizes in polymers and biological systems. This free volume is critical in explaining and understanding physical and mechanical properties of polymers. Moreover, PALS has been recently proposed as a potential tool in detecting cancer at early stages, probing the differences in the subnanometer scale free volume voids between cancerous/healthy skin samples of the same patient. Despite several investigations on free volume in complex cancerous tissues, no positron annihilation studies of living cancer cell cultures have been reported. We demonstrate that PALS can be applied to the study in human living 3D cell cultures. The technique is also capable to detect atomic scale changes in the size of the free volume voids due to the biological responses to TGF-β. PALS may be developed to characterize the effect of different culture conditions in the free volume voids of cells grown in vitro.

  19. Radiation induced changes in electrical conductivity of chemical vapor deposited silicon carbides under fast neutron and gamma-ray irradiations

    Energy Technology Data Exchange (ETDEWEB)

    Tsuchiya, Bun, E-mail: btsuchiya@meijo-u.ac.jp [Department of General Education, Faculty of Science and Technology, Meijo University, 1-501, Shiogamaguchi, Tempaku-ku, Nagoya 468-8502 (Japan); Shikama, Tatsuo; Nagata, Shinji; Saito, Kesami [Institute for Materials Research, Tohoku University, 2-1-1, Katahira, Aoba-ku, Sendai 980-8577 (Japan); Yamamoto, Syunya [Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency, 1233, Watanuki-machi, Takasaki, Gunma 370-1292 (Japan); Ohnishi, Seiki [Tokai Research and Development Center, Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Nozawa, Takashi [Aomori Research and Development Center, Japan Atomic Energy Agency, 2-166, Omotedate, Obuchi, Rokkasho, Aomori 039-3212 (Japan)

    2011-10-15

    The radiation-induced changes in the volume electrical conductivities of chemical vapor deposited silicon carbides (CVD-SiCs) were in-site investigated by performing irradiation using 1.17 and 1.33-MeV gamma-ray and 14-MeV fast neutron beams in air and vacuum. Under gamma-ray irradiation at ionization dose rates of 3.6 and 5.9 Gy/s and irradiation temperature of approximately 300 K, the initial rapid increase in electrical conductivity; this is indicative of radiation-induced conductivity (RIC), occurred due to electronic excitation, and a more gradual increase followed up to a dose of approximately 10-50 kGy corresponding to the results in base conductivity without radiation; this is indicative of radiation-induced electrical degradation (RIED). However, the radiation-induced phenomena were not observed at irradiation temperatures above 373 K. Under neutron irradiation at a further low dose rate below approximately 2.1 Gy/s, a fast neutron flux of 9.2 x 10{sup 14} n/m{sup 2} s, and 300 K, the RIED-like behavior according to radiation-induced modification of the electrical property occurred with essentially no displacement damage, but ionizing effects (radiolysis).

  20. Effects of Hormone Therapy on Brain Volumes Changes of Postmenopausal Women Revealed by Optimally-Discriminative Voxel-Based Morphometry.

    Directory of Open Access Journals (Sweden)

    Tianhao Zhang

    Full Text Available The Women's Health Initiative Memory Study Magnetic Resonance Imaging (WHIMS-MRI provides an opportunity to evaluate how menopausal hormone therapy (HT affects the structure of older women's brains. Our earlier work based on region of interest (ROI analysis demonstrated potential structural changes underlying adverse effects of HT on cognition. However, the ROI-based analysis is limited in statistical power and precision, and cannot provide fine-grained mapping of whole-brain changes.We aimed to identify local structural differences between HT and placebo groups from WHIMS-MRI in a whole-brain refined level, by using a novel method, named Optimally-Discriminative Voxel-Based Analysis (ODVBA. ODVBA is a recently proposed imaging pattern analysis approach for group comparisons utilizing a spatially adaptive analysis scheme to accurately locate areas of group differences, thereby providing superior sensitivity and specificity to detect the structural brain changes over conventional methods.Women assigned to HT treatments had significant Gray Matter (GM losses compared to the placebo groups in the anterior cingulate and the adjacent medial frontal gyrus, and the orbitofrontal cortex, which persisted after multiple comparison corrections. There were no regions where HT was significantly associated with larger volumes compared to placebo, although a trend of marginal significance was found in the posterior cingulate cortical area. The CEE-Alone and CEE+MPA groups, although compared with different placebo controls, demonstrated similar effects according to the spatial patterns of structural changes.HT had adverse effects on GM volumes and risk for cognitive impairment and dementia in older women. These findings advanced our understanding of the neurobiological underpinnings of HT effects.

  1. Anesthesia-Induced Hypothermia Attenuates Early-Phase Blood-Brain Barrier Disruption but Not Infarct Volume following Cerebral Ischemia.

    Science.gov (United States)

    Liu, Yu-Cheng; Lee, Yu-Da; Wang, Hwai-Lee; Liao, Kate Hsiurong; Chen, Kuen-Bao; Poon, Kin-Shing; Pan, Yu-Ling; Lai, Ted Weita

    2017-01-01

    Blood-brain barrier (BBB) disruption is thought to facilitate the development of cerebral infarction after a stroke. In a typical stroke model (such as the one used in this study), the early phase of BBB disruption reaches a peak 6 h post-ischemia and largely recovers after 8-24 h, whereas the late phase of BBB disruption begins 48-58 h post-ischemia. Because cerebral infarct develops within 24 h after the onset of ischemia, and several therapeutic agents have been shown to reduce the infarct volume when administered at 6 h post-ischemia, we hypothesized that attenuating BBB disruption at its peak (6 h post-ischemia) can also decrease the infarct volume measured at 24 h. We used a mouse stroke model obtained by combining 120 min of distal middle cerebral arterial occlusion (dMCAo) with ipsilateral common carotid arterial occlusion (CCAo). This model produced the most reliable BBB disruption and cerebral infarction compared to other models characterized by a shorter duration of ischemia or obtained with dMCAO or CCAo alone. The BBB permeability was measured by quantifying Evans blue dye (EBD) extravasation, as this tracer has been shown to be more sensitive for the detection of early-phase BBB disruption compared to other intravascular tracers that are more appropriate for detecting late-phase BBB disruption. We showed that a 1 h-long treatment with isoflurane-anesthesia induced marked hypothermia and attenuated the peak of BBB disruption when administered 6 h after the onset of dMCAo/CCAo-induced ischemia. We also demonstrated that the inhibitory effect of isoflurane was hypothermia-dependent because the same treatment had no effect on ischemic BBB disruption when the mouse body temperature was maintained at 37°C. Importantly, inhibiting the peak of BBB disruption by hypothermia had no effect on the volume of brain infarct 24 h post-ischemia. In conclusion, inhibiting the peak of BBB disruption is not an effective neuroprotective strategy, especially in comparison

  2. Comparison of changes in markers of muscle damage induced by eccentric exercise and ischemia/reperfusion.

    Science.gov (United States)

    Su, Q-S; Zhang, J-G; Dong, R; Hua, B; Sun, J-Z

    2010-10-01

    To examine the effects of eccentric exercise (EE) and ischemia/reperfusion (I/R) on the markers of muscle damage, 72 rats were randomly assigned to the EE group, I/R group and control group (C), respectively. The rats in EE ran downhill on a treadmill with a 16 ° inclination at a constant speed for 90 min, and the rats in the I/R group underwent 90 min of four-limb ischemia, followed by 24, 48 and 72 h of reperfusion. Blood and tissue samples were collected immediately, 24, 48 and 72 h after exercise or reperfusion. Quantitative analyses showed that the I/R group had a significantly larger mitochondrial volume at 24 h after reperfusion compared with the C, and there were more disrupted Z-lines in the EE group and more disrupted mitochondria in the I/R group at 24 h after exercise or reperfusion. When compared with the C, a significantly lower total antioxidant capacity and higher interleukin-6 value were observed after exercise or reperfusion. Our data suggest that although EE and I/R result in some similar changes in the muscle damage markers, there are still some differences. The EE- and I/R-induced muscle damage may be due to different mechanisms.

  3. Gray matter volume changes in chronic subcortical stroke: A cross-sectional study

    Directory of Open Access Journals (Sweden)

    Qingqing Diao

    2017-01-01

    Full Text Available This study aimed to investigate the effects of lesion side and degree of motor recovery on gray matter volume (GMV difference relative to healthy controls in right-handed subcortical stroke. Structural MRI data were collected in 97 patients with chronic subcortical ischemic stroke and 79 healthy controls. Voxel-wise GMV analysis was used to investigate the effects of lesion side and degree of motor recovery on GMV difference in right-handed chronic subcortical stroke patients. Compared with healthy controls, right-lesion patients demonstrated GMV increase (P < 0.05, voxel-wise false discovery rate correction in the bilateral paracentral lobule (PCL and supplementary motor area (SMA and the right middle occipital gyrus (MOG; while left-lesion patients did not exhibit GMV difference under the same threshold. Patients with complete and partial motor recovery showed similar degree of GMV increase in right-lesion patients. However, the motor recovery was correlated with the GMV increase in the bilateral SMA in right-lesion patients. These findings suggest that there exists a lesion-side effect on GMV difference relative to healthy controls in right-handed patients with chronic subcortical stroke. The GMV increase in the SMA may facilitate motor recovery in subcortical stroke patients.

  4. Safe use of mine winding rope, volume 2: recommendations for changes in rope safety factors.

    CSIR Research Space (South Africa)

    Hecker, GFK

    1996-04-01

    Full Text Available The steering committee on factors of safety of winder ropes has appointed a working group to draw up a set of proposals for changing the regulations governing the required rope strength in the Minerals Act. Certain research projects have been...

  5. Battelle Research Outlook, Volume 2 Number 2. The Schools: Organizing for Change.

    Science.gov (United States)

    Westerman, Arthur B., Ed.

    "Outlook" publications focus on areas of science and technology in which research can be valuable to industry, government, and society as a whole. Their purpose is to point up significant current problems in those areas and to suggest effective research approaches to their solution. This issue, dealing with changes taking place in our schools and…

  6. Finite volume analysis of temperature effects induced by active MRI implants with cylindrical symmetry: 1. Properly working devices

    Directory of Open Access Journals (Sweden)

    Schnorr Jörg

    2005-04-01

    Full Text Available Abstract Background Active Magnetic Resonance Imaging implants are constructed as resonators tuned to the Larmor frequency of a magnetic resonance system with a specific field strength. The resonating circuit may be embedded into or added to the normal metallic implant structure. The resonators build inductively coupled wireless transmit and receive coils and can amplify the signal, normally decreased by eddy currents, inside metallic structures without affecting the rest of the spin ensemble. During magnetic resonance imaging the resonators generate heat, which is additional to the usual one described by the specific absorption rate. This induces temperature increases of the tissue around the circuit paths and inside the lumen of an active implant and may negatively influence patient safety. Methods This investigation provides an overview of the supplementary power absorbed by active implants with a cylindrical geometry, corresponding to vessel implants such as stents, stent grafts or vena cava filters. The knowledge of the overall absorbed power is used in a finite volume analysis to estimate temperature maps around different implant structures inside homogeneous tissue under worst-case assumptions. The "worst-case scenario" assumes thermal heat conduction without blood perfusion inside the tissue around the implant and mostly without any cooling due to blood flow inside vessels. Results The additional power loss of a resonator is proportional to the volume and the quality factor, as well as the field strength of the MRI system and the specific absorption rate of the applied sequence. For properly working devices the finite volume analysis showed only tolerable heating during MRI investigations in most cases. Only resonators transforming a few hundred mW into heat may reach temperature increases over 5 K. This requires resonators with volumes of several ten cubic centimeters, short inductor circuit paths with only a few 10 cm and a quality

  7. Radiation-induced changes in normal-appearing gray matter in patients with nasopharyngeal carcinoma: a magnetic resonance imaging voxel-based morphometry study

    Energy Technology Data Exchange (ETDEWEB)

    Lv, Xiao-Fei; Zheng, Xiao-Li; Zhang, Wei-Dong; Liu, Li-Zhi; Zhang, You-Ming [State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou (China); Sun Yat-sen University Cancer Center, Department of Medical Imaging and Interventional Radiology, Guangzhou (China); Chen, Ming-Yuan [Sun Yat-sen University Cancer Center, Department of Nasopharyngeal Carcinoma, Guangzhou (China); Li, Li [Sun Yat-sen University Cancer Center, Department of Medical Imaging and Interventional Radiology, Guangzhou (China)

    2014-05-15

    Evidence is accumulating that temporal lobe radiation necrosis in patients with nasopharyngeal carcinoma (NPC) after radiotherapy (RT) could involve gray matter (GM). The purpose of the study was to assess the radiation-induced GM volume differences between NPC patients who had and had not received RT and the effect of time after RT on GM volume differences in those patients who had received RT. We used magnetic resonance imaging voxel-based morphometry (VBM) to assess differences in GM volume between 30 NPC patients with normal-appearing whole-brain GM after RT and 15 control patients with newly diagnosed but not yet medically treated NPC. Correlation analyses were used to investigate the relationship between GM volume changes and time after RT. Patients who had received RT had GM volume decreases in the bilateral superior temporal gyrus, left middle temporal gyrus, right fusiform gyrus, right precentral gyrus, and right inferior parietal lobule (p < 0.001, uncorrected, cluster size >100 voxels). Moreover, the correlation analysis indicated that regional GM volume loss in the left superior temporal gyrus, left middle temporal gyrus, and right fusiform gyrus were negatively related to the mean dose to the ipsilateral temporal lobe, respectively. These results indicate that GM volume deficits in bilateral temporal lobes in patients who had received RT might be radiation-induced. Our findings might provide new insight into the pathogenesis of radiation-induced structural damage in normal-appearing brain tissue. Yet this is an exploratory study, whose findings should therefore be taken with caution. (orig.)

  8. Tectonics, orbital forcing, global climate change, and human evolution in Africa: introduction to the African paleoclimate special volume.

    Science.gov (United States)

    Maslin, Mark A; Christensen, Beth

    2007-11-01

    The late Cenozoic climate of Africa is a critical component for understanding human evolution. African climate is controlled by major tectonic changes, global climate transitions, and local variations in orbital forcing. We introduce the special African Paleoclimate Issue of the Journal of Human Evolution by providing a background for and synthesis of the latest work relating to the environmental context for human evolution. Records presented in this special issue suggest that the regional tectonics, appearance of C(4) plants in East Africa, and late Cenozoic global cooling combined to produce a long-term drying trend in East Africa. Of particular importance is the uplift associated with the East African Rift Valley formation, which altered wind flow patterns from a more zonal to more meridinal direction. Results in this volume suggest a marked difference in the climate history of southern and eastern Africa, though both are clearly influenced by the major global climate thresholds crossed in the last 3 million years. Papers in this volume present lake, speleothem, and marine paleoclimate records showing that the East African long-term drying trend is punctuated by episodes of short, alternating periods of extreme wetness and aridity. These periods of extreme climate variability are characterized by the precession-forced appearance and disappearance of large, deep lakes in the East African Rift Valley and paralleled by low and high wind-driven dust loads reaching the adjacent ocean basins. Dating of these records show that over the last 3 million years such periods only occur at the times of major global climatic transitions, such as the intensification of Northern Hemisphere Glaciation (2.7-2.5 Ma), intensification of the Walker Circulation (1.9-1.7 Ma), and the Mid-Pleistocene Revolution (1-0.7 Ma). Authors in this volume suggest this onset occurs as high latitude forcing in both Hemispheres compresses the Intertropical Convergence Zone so that East Africa

  9. Temporal changes in integrin-mediated cardiomyocyte adhesion secondary to chronic cardiac volume overload in rats

    Science.gov (United States)

    Stewart, James A.; Gardner, Jason D.; Brower, Gregory L.

    2013-01-01

    Previous studies have established integrins as cell surface receptors that mediate cardiomyocyte-extracellular matrix (ECM) attachments. This study sought to determine the contributions of the myocardial β1- and β3-integrin subunits to ventricular dilatation and coronary flow regulation using a blood-perfused isolated heart preparation. Furthermore, cardiomyocyte adhesion to collagen types I and IV, fibronectin, and laminin with and without a β1-integrin subunit neutralizing antibody was assessed during the course of remodeling secondary to a sustained cardiac volume overload, including the onset of heart failure. Isolated cardiomyocytes were obtained during the initial, compensated, and decompensated phases of remodeling resulting from an aortocaval fistula created in 8-wk-old male Sprague-Dawley rats. Blocking the β1-integrin subunit in isolated normal hearts produced ventricular dilatation, whereas this was not the case when the β3-subunit was blocked. Substantial reductions in cardiomyocyte adhesion coincided with the previously documented development of ventricular dilatation and decreased contractility postfistula, with the β1-integrin contribution to adhesion ranging from 28% to 73% over the course of remodeling being essentially substrate independent. In contrast, both integrin subunits were found to be involved in regulating coronary vascular resistance. It is concluded that marked reductions in integrin-mediated cardiomyocyte adhesion to the ECM play a significant role in the progression of adverse myocardial remodeling that leads to heart failure. Furthermore, although both the β1- and β3-integrin subunits were involved in regulating coronary vascular resistance, only inhibition of β1-integrin-mediated adhesion resulted in ventricular dilatation of the normal heart. PMID:24163072

  10. Playing Super Mario induces structural brain plasticity: gray matter changes resulting from training with a commercial video game.

    Science.gov (United States)

    Kühn, S; Gleich, T; Lorenz, R C; Lindenberger, U; Gallinat, J

    2014-02-01

    Video gaming is a highly pervasive activity, providing a multitude of complex cognitive and motor demands. Gaming can be seen as an intense training of several skills. Associated cerebral structural plasticity induced has not been investigated so far. Comparing a control with a video gaming training group that was trained for 2 months for at least 30 min per day with a platformer game, we found significant gray matter (GM) increase in right hippocampal formation (HC), right dorsolateral prefrontal cortex (DLPFC) and bilateral cerebellum in the training group. The HC increase correlated with changes from egocentric to allocentric navigation strategy. GM increases in HC and DLPFC correlated with participants' desire for video gaming, evidence suggesting a predictive role of desire in volume change. Video game training augments GM in brain areas crucial for spatial navigation, strategic planning, working memory and motor performance going along with evidence for behavioral changes of navigation strategy. The presented video game training could therefore be used to counteract known risk factors for mental disease such as smaller hippocampus and prefrontal cortex volume in, for example, post-traumatic stress disorder, schizophrenia and neurodegenerative disease.

  11. Left ventricular pressure-volume diagrams and end-systolic pressure-volume relations in human beings.

    Science.gov (United States)

    McKay, R G; Aroesty, J M; Heller, G V; Royal, H; Parker, J A; Silverman, K J; Kolodny, G M; Grossman, W

    1984-02-01

    Assessment of left ventricular pressure-volume relations serially in response to altered loading conditions and heart rate has been difficult to achieve with contrast ventriculography. Accordingly, to study changing pressure-volume relations during altered loading and heart rate, left ventricular pressure and radionuclide absolute volume curves (obtained using a counts-based method with attenuation factor corrections) were recorded in 20 patients. Ventricular pressure and radionuclide volume curves were digitized and synchronized to end-diastole, and pressure-volume plots were subsequently constructed from 32 pressure-volume coordinates throughout the cardiac cycle. In all patients, the correlation between radionuclide absolute volumes and angiographic ventricular volumes was r = 0.92. In 10 patients in whom both radionuclide and angiographic pressure-volume diagrams were constructed, the agreement between the two methods was excellent. With this method, end-systolic pressure-volume relations were examined during altered left ventricular loading conditions, pacing-induced incremental increases in heart rate and pacing-induced ischemia. Using pharmacologically induced changes in left ventricular loading conditions, the slope and volume intercept of the end-systolic pressure-volume line could be calculated as a means of assessing basal contractility. During pacing-induced tachycardia, the slope and volume intercept of the end-systolic pressure-volume line could be calculated to quantify the Treppe effect and assess negative inotropic changes secondary to ischemia. This study supports the validity of using serial recordings of left ventricular pressure and radionuclide volumes to assess left ventricular pressure-volume relations, and indicates that this approach may be useful in the analysis of end-systolic pressure-volume relations in patients.

  12. Left ventricular pressure-volume diagrams and end-systolic pressure-volume relations in human beings

    Energy Technology Data Exchange (ETDEWEB)

    McKay, R.G.; Aroesty, J.M.; Heller, G.V.; Royal, H.; Parker, J.A.; Silverman, K.J.; Kolodny, G.M.; Grossman, W.

    1984-02-01

    Assessment of left ventricular pressure-volume relations serially in response to altered loading conditions and heart rate has been difficult to achieve with contrast ventriculography. Accordingly, to study changing pressure-volume relations during altered loading and heart rate, left ventricular pressure and radionuclide absolute volume curves (obtained using a counts-based method with attenuation factor corrections) were recorded in 20 patients. Ventricular pressure and radionuclide volume curves were digitized and synchronized to end-diastole, and pressure-volume plots were subsequently constructed from 32 pressure-volume coordinates throughout the cardiac cycle. In all patients, the correlation between radionuclide absolute volumes and angiographic ventricular volumes was r . 0.92. In 10 patients in whom both radionuclide and angiographic pressure-volume diagrams were constructed, the agreement between the two methods was excellent. With this method, end-systolic pressure-volume relations were examined during altered left ventricular loading conditions, pacing-induced incremental increases in heart rate and pacing-induced ischemia. Using pharmacologically induced changes in left ventricular loading conditions, the slope and volume intercept of the end-systolic pressure-volume line could be calculated as a means of assessing basal contractility. During pacing-induced tachycardia, the slope and volume intercept of the end-systolic pressure-volume line could be calculated to quantify the Treppe effect and assess negative inotropic changes secondary to ischemia. This study supports the validity of using serial recordings of left ventricular pressure and radionuclide volumes to assess left ventricular pressure-volume relations, and indicates that this approach may be useful in the analysis of end-systolic pressure-volume relations in patients.

  13. Predicting Persuasion-Induced Behavior Change from the Brain

    Science.gov (United States)

    Falk, Emily B.; Berkman, Elliot T.; Mann, Traci; Harrison, Brittany; Lieberman, Matthew D.

    2011-01-01

    Although persuasive messages often alter people’s self-reported attitudes and intentions to perform behaviors, these self-reports do not necessarily predict behavior change. We demonstrate that neural responses to persuasive messages can predict variability in behavior change in the subsequent week. Specifically, an a priori region of interest (ROI) in medial prefrontal cortex (MPFC) was reliably associated with behavior change (r = 0.49, p < 0.05). Additionally, an iterative cross-validation approach using activity in this MPFC ROI predicted an average 23% of the variance in behavior change beyond the variance predicted by self-reported attitudes and intentions. Thus, neural signals can predict behavioral changes that are not predicted from self-reported attitudes and intentions alone. Additionally, this is the first functional magnetic resonance imaging study to demonstrate that a neural signal can predict complex real world behavior days in advance. PMID:20573889

  14. Morphology of femtosecond laser-induced structural changes in KTP crystal

    Energy Technology Data Exchange (ETDEWEB)

    Li Yuhua [State Key Lab of Laser Technology and Wuhan National Lab for Optoelectronics, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074, Hubei (China); Lu Peixiang [State Key Lab of Laser Technology and Wuhan National Lab for Optoelectronics, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074, Hubei (China)]. E-mail: lupeixiang@mail.hust.edu.cn; Dai Nengli [State Key Lab of Laser Technology and Wuhan National Lab for Optoelectronics, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074, Hubei (China); Long Hua [State Key Lab of Laser Technology and Wuhan National Lab for Optoelectronics, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074, Hubei (China); Wang Ying [State Key Lab of Laser Technology and Wuhan National Lab for Optoelectronics, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074, Hubei (China); Yu Benhai [State Key Lab of Laser Technology and Wuhan National Lab for Optoelectronics, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074, Hubei (China)

    2006-11-30

    The morphology of structural changes in KTP crystal induced by single femtosecond laser pulse has been investigated by means of CCD camera, scanning electron microscopy (SEM) and atom force microscopy (AFM). The structurally changed region is depressed at energies close to the threshold for producing a structural change and melting ablation morphologies are observed as pulse energy is increased. Furthermore, periodic nanostructures are formed around the edge of the laser-induced spots.

  15. Morphine dependence and withdrawal induced changes in cholinergic signaling

    Science.gov (United States)

    Neugebauer, Nichole M.; Einstein, Emily B.; Lopez, Maria B.; McClure-Begley, Tristan D.; Mineur, Yann S.; Picciotto, Marina R.

    2013-01-01

    Cholinergic signaling is thought to be involved in morphine dependence and withdrawal, but the specific mechanisms involved remain unclear. The current study aimed to identify alterations in the cholinergic system that may contribute to the development of morphine dependence and withdrawal. Acetylcholinesterase (AChE) activity and [3H]-epibatidine binding were evaluated in order to determine if morphine dependence and withdrawal induces alterations in cholinergic signaling or expression of high affinity nicotinic acetylcholine receptors (nAChRs) in the midbrain (MB), medial habenula (MHb) and interpeduncular nucleus (IPN). The effect of cholinergic signaling through nAChRs on morphine-withdrawal induced jumping behavior was then determined. Lastly, the contribution of β4-containing nAChRs receptors in the MHb to morphine-withdrawal induced jumping behavior and neuronal activity as indicated by c-fos expression was assessed. Chronic morphine administration decreased AChE activity in MB and MHb, an effect that was no longer present following precipitated withdrawal. Morphine dependent mice showed increased nicotinic acetylcholine receptor (nAChR) levels in MB. Further, nicotine (0.4 mg/kg) and lobeline (3 mg/kg) decreased jumping behavior while mecamylamine (1 mg/kg) had no effect. Knock-down of β4 subunit-containing nAChRs in the MHb attenuated c-fos activation, but did not decrease morphine withdrawal-induced jumping. Thus, morphine withdrawal induces cholinergic signaling in the MHb, but this does not appear to be responsible for the effects of cholinergic drugs on somatic signs of opiate withdrawal, as measured by jumping behavior. PMID:23651795

  16. The excluded volume effect induced by poly(ethylene glycol) modulates the motility of actin filaments interacting with myosin.

    Science.gov (United States)

    Munakata, Shinsuke; Hatori, Kuniyuki

    2013-11-01

    To examine the motility of actomyosin complexes in the presence of high concentrations of polymers, we investigated the effect of poly(ethylene glycol) on the sliding velocities of actin filaments and regulated thin filaments on myosin molecules in the presence of ATP. Increased concentrations and relative molecular masses of poly(ethylene glycol) decreased the sliding velocities of actin and regulated thin filaments. The decreased ratio of velocity in regulated thin filaments at - log[Ca(2+) ] of 4 was higher than that of actin filaments. Furthermore, in the absence of Ca(2+) , regulated thin filaments were moderately motile in the presence of poly(ethylene glycol). The excluded volume change (∆V), defined as the change in water volume surrounding actomyosin during the interactions, was estimated by determining the relationship between osmotic pressure exerted by poly(ethylene glycol) and the decreased ratio of the velocities in the presence and absence of poly(ethylene glycol). The ∆V increased up to 3.7 × 10(5) Å(3) as the Mr range of poly(ethylene glycol) was increased up to 20,000. Moreover, the ∆V for regulated thin filaments was approximately two-fold higher than that of actin filaments. This finding suggests that differences in the conformation of filaments according to whether troponin-tropomyosin complexes lie on actin filaments alter the ∆V during interactions of actomyosin complexes and influence motility. © 2013 FEBS.

  17. Pulmonary intravascular blood volume changes through the cardiac cycle in healthy volunteers studied by cardiovascular magnetic resonance measurements of arterial and venous flow

    Directory of Open Access Journals (Sweden)

    Arheden Hakan

    2009-10-01

    Full Text Available Abstract Background This study aims to present a novel method for using cardiovascular magnetic resonance (CMR to non-invasively quantify the variation in pulmonary blood volume throughout the cardiac cycle in humans. Methods 10 healthy volunteers (7 males, 3 female, age range 21-32 years were studied. The blood flow in the pulmonary artery and all pulmonary veins was quantified during free breathing using phase contrast velocity encoded CMR. The difference in flow between the pulmonary artery and the pulmonary veins was integrated to calculate the change in pulmonary blood volume throughout the cardiac cycle. Results The stroke volumes in the pulmonary artery and the sum of the pulmonary veins were (mean ± SEM 103 ± 6 ml and 95 ± 6 ml, respectively. The pulmonary blood volume variation (PBVV was 48 ± 5 ml, and the PBVV expressed as percent of the pulmonary artery stroke volume was 46 ± 3%. The maximum increase in pulmonary blood volume occurred 310 ± 12 ms after the R-wave from the ECG (32 ± 2% of the cardiac cycle. PBVV did not correlate to change in cross-sectional area in the pulmonary artery (R2 = 0.03, p = 0.66. Conclusion It is feasible to non-invasively quantify the change in pulmonary blood volume during the cardiac cycle in humans using CMR. The average pulmonary blood volume variation in healthy volunteers was approximately 50 ml and this was approximately 50% of the stroke volume. Further studies are needed to assess the utility of the pulmonary blood volume variation as a measure for identifying cardiac and pulmonary vascular disease.

  18. Plasma volume substitution does not inhibit plasma noradrenaline and muscle nerve sympathetic responses to insulin-induced hypoglycaemia in healthy humans

    DEFF Research Database (Denmark)

    Frandsen, Henrik Lund; Berne, C; Fagius, J;

    1989-01-01

    underly the sympathetic activation. To study the effect of prevention of plasma volume reduction during hypoglycaemia, saline containing albumin was infused intravenously in healthy adult volunteers during hypoglycaemia. Hypoglycaemia was induced by an intravenous injection of soluble insulin in a dose...... of 0.15 IU/kg body weight. Peripheral venous plasma noradrenaline concentrations were identical in experiments without and with plasma volume substitution. Muscle nerve sympathetic activity increased to the same extent during hypoglycaemia with and without plasma volume substitution. It is concluded...

  19. [Morphopathological changes in glaucoma-induced trabecular meshwork].

    Science.gov (United States)

    Petraru, D; Indrei, Anca; Costin, D; Mihalache, G

    2011-01-01

    Glaucoma causes trabecular meshwork and Schlemm canal changes, resulting in the obstruction of the aqueous flow at this level. To show the histological changes in the surgically removed trabecular meshwork tissues. Trabecular meshwork fragments were histologically processed for histological diagnosis. 29.87% of all patients had ordered structure with high eosinophilia, 20.12% a rare structure with high eosinophilia, 21.34% a voluminous trabecular meshwork with fusiform cells, 21.03% tissue fibrosis and 7.62% had tissue necrosis. Aqueous flow obstruction in trabecular meshwork is produced by the histological changes at this level, found in all tissue specimens removed during surgery.

  20. Comparison of grey matter volume and thickness for analysing cortical changes in chronic schizophrenia: a matter of surface area, grey/white matter intensity contrast, and curvature.

    Science.gov (United States)

    Kong, Li; Herold, Christina J; Zöllner, Frank; Salat, David H; Lässer, Marc M; Schmid, Lena A; Fellhauer, Iven; Thomann, Philipp A; Essig, Marco; Schad, Lothar R; Erickson, Kirk I; Schröder, Johannes

    2015-02-28

    Grey matter volume and cortical thickness are the two most widely used measures for detecting grey matter morphometric changes in various diseases such as schizophrenia. However, these two measures only share partial overlapping regions in identifying morphometric changes. Few studies have investigated the contributions of the potential factors to the differences of grey matter volume and cortical thickness. To investigate this question, 3T magnetic resonance images from 22 patients with schizophrenia and 20 well-matched healthy controls were chosen for analyses. Grey matter volume and cortical thickness were measured by VBM and Freesurfer. Grey matter volume results were then rendered onto the surface template of Freesurfer to compare the differences from cortical thickness in anatomical locations. Discrepancy regions of the grey matter volume and thickness where grey matter volume significantly decreased but without corresponding evidence of cortical thinning involved the rostral middle frontal, precentral, lateral occipital and superior frontal gyri. Subsequent region-of-interest analysis demonstrated that changes in surface area, grey/white matter intensity contrast and curvature accounted for the discrepancies. Our results suggest that the differences between grey matter volume and thickness could be jointly driven by surface area, grey/white matter intensity contrast and curvature.

  1. Regulation of cloned, Ca2+-activated K+ channels by cell volume changes

    DEFF Research Database (Denmark)

    Grunnet, Morten; MacAulay, Nanna; Jorgensen, Nanna K;

    2002-01-01

    Ca2+-activated K+ channels of big (hBK), intermediate (hIK) or small (rSK3) conductance were co-expressed with aquaporin 1 (AQP1) in Xenopus laevis oocytes. hBK channels were activated by depolarization, whereas hIK and rSK3 channels were activated by direct injection of Ca2+ or Cd2+ into the ooc......Ca2+-activated K+ channels of big (hBK), intermediate (hIK) or small (rSK3) conductance were co-expressed with aquaporin 1 (AQP1) in Xenopus laevis oocytes. hBK channels were activated by depolarization, whereas hIK and rSK3 channels were activated by direct injection of Ca2+ or Cd2......+ into the oocyte cytoplasm, before the oocytes were subjected to hyperosmolar or hypoosmolar (+/-50 mOsm mannitol) challenges. In all cases, the oocytes responded rapidly to the osmotic changes with shrinkage or swelling and the effects on the K+ currents were measured. hIK and rSK3 currents were highly sensitive......IK/rSK3 and hBK channels suggest that the significant stimulation of hIK and rSK3 channels during swelling is not mediated by changes in intracellular Ca2+, but rather through interactions with the cytoskeleton, provided that a sufficient basal concentration of intracellular Ca2+ or Cd2+ is present....

  2. Changing times. Southwest Energy-Minerals Conference Proceedings, Volumes 1 and 2

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-01-01

    This conference was held at the Albuquerque Convention Center, Albuquerque, NM, Nov. 2 and 3, 1977. It was sponsored by the Bureau of Land Management, U.S. Dept. of the Interior. It contains articles on the leasing of coal deposits (changes and modifications of leasing policy, environmental impact statements, U.S. energy policy (NEP), prices of gas and oil), New Mexico's energy consumption (by the Governor), transport of energy (Santa Fe railroad's plans), the energy crisis and proposed solutions, energy supplies and environmental problems, energy problems of agriculture (fuels, fertilizers and water energy requirements are greater than the energy in the food produced; possibility of biomass conversion, photosynthetic efficiency of using sunlight in arid lands), energy project financing, a review of the recent Law of the Sea conferences (1967 to date) (mining projects), growth economy as no growth and relation to energy supplies and environmental problems, natural gas and petroleum industries (divestiture problems, reserves), raw materials stockpiles (national experience, changing targets), the mining industry and its reserves of metals, taxation, etc.). (LTN)

  3. Turn down the volume or change the channel? Emotional effects of detached versus positive reappraisal.

    Science.gov (United States)

    Shiota, Michelle N; Levenson, Robert W

    2012-09-01

    Cognitive reappraisal, or changing one's interpretation of an event in order to alter the emotional response to it, is thought to be a healthy and an effective emotion regulation strategy. Although researchers recognize several distinct varieties of reappraisal, few studies have explicitly compared the effects of multiple reappraisal strategies on emotional responding. The present study compares the effects of detached and positive reappraisal on thought content, subjective emotional experience, physiological reactivity, and facial expressions of emotion while viewing film clips evoking sadness and disgust. Although both forms of reappraisal reduced overall emotional responding to unpleasant stimuli, the effects of detached reappraisal were stronger in this regard, and positive reappraisal was more likely to maintain subjective experience and facial expression of stimulus-appropriate positive emotions. The two reappraisal strategies also produced somewhat different profiles of physiological responding. Differences between detached and positive reappraisal with respect to subjective experience and facial expression were more pronounced among men than women; the reverse was true for differences with respect to physiological responding. Beyond these effects on individual emotion response systems, detached and positive reappraisal also had somewhat different effects on coherence in change across response systems. Implications for our understanding of emotion regulation processes, and for emotion theory more broadly, are discussed.

  4. Turn Down the Volume or Change the Channel?: Emotional Effects of Detached Versus Positive Reappraisal

    Science.gov (United States)

    Shiota, Michelle N.; Levenson, Robert W.

    2013-01-01

    Cognitive reappraisal, or changing one’s interpretation of an event in order to alter the emotional response to it, is thought to be a healthy and effective emotion regulation strategy. Although researchers recognize several distinct varieties of reappraisal, few studies have explicitly compared the effects of multiple reappraisal strategies on emotional responding. The present study compares the effects of detached and positive reappraisal on thought content, subjective emotional experience, physiological reactivity, and facial expressions of emotion while viewing film clips evoking sadness and disgust. While both forms of reappraisal reduced overall emotional responding to unpleasant stimuli, the effects of detached reappraisal were stronger in this regard, and positive reappraisal was more likely to maintain subjective experience and facial expression of stimulus-appropriate positive emotions. The two reappraisal strategies also produced somewhat different profiles of physiological responding. Differences between detached and positive reappraisal with respect to subjective experience and facial expression were more pronounced among men than women; the reverse was true for differences with respect to physiological responding. Beyond these effects on individual emotion response systems, detached and positive reappraisal also had somewhat different effects on coherence in change across response systems. Implications for our understanding of emotion regulation processes, and for emotion theory more broadly, are discussed. PMID:22746676

  5. Glacier length, area and volume changes in the Himalaya: an overview and specific examples

    Science.gov (United States)

    Bolch, T.; Bhambri, R.; Kamp, U.; Pieczonka, T.

    2011-12-01

    The Himalaya comprises one of the largest glacier-covered areas outside the polar regions. Glaciers are of special interest for several reasons. For instance, receding glaciers can cause the development of hazardous glacial lakes and glaciers contribute to the overall river runoff. The importance of the glacier melt to run off, however, varies significantly depending especially on the precipitation regime. Previous studies indicate that the vast majority of the Himalayan glaciers retreated during the recent decades with only few exemptions. Although the numbers of investigates glaciers increased in the last few years, there is still a lack of knowledge about the glacier behaviour in the different regions of the Himalaya. Existing length measurements in the Indian Himalaya show continuous retreat with an accelerating trend in recent years for most of the glaciers. The annual retreat rates vary between ~5m and more than 50m. However, several measurements are based on topographic maps or coarse satellite data and can have therefore higher uncertainties. Own reassessments for the debris-covered Gangotri Glacier situated in Garhwal Himalaya/western India based on high resolution imagery such as Corona, Hexagon, IRS PAN, LISS IV, and Cartosat-1 show an continuous retreat with an average rate of 19.9 ± 0.3 m a-1 from 1965 to 2006. This is significant but less than previously published. Similar results were revealed for the area changes in upper Alaknanda and Bhagirathi valleys in Garhwal Himalaya. We found a lower but still significant area loss of 4.6 ± 2.8 % between 1968 and 2006. Area changes in Khumbu Himalaya/Nepal are with ~5% between 1962 and 2005 comparable. Investigations in the Greater Himalayan Range in southern Ladakh/northwest India revealed a general receding trend but with some of the larger glaciers with high altitude catchments being stable or even advancing. Preliminary results for Shyok Valley (Jammu and Kashmir) show on average stable or slightly

  6. Effect of change in blood volume in skin plus active muscle on heart rate drift during submaximal exercise.

    Science.gov (United States)

    Yano, T; Yunoki, T; Matsuura, R; Arimitsu, T; Kimura, T

    2008-12-01

    The purpose of the present study was to examine the effect of change in blood volume in skin plus active muscle on heart rate drift during moderate exercise and heavy exercise for 30 min. Total hemoglobin concentration (Total Hb) in the vastus lateralis muscle plus its skin was determined by near-infrared spectroscopy. Total Hb significantly increased and remained stable from 20 min in moderate exercise and from 10 min in heavy exercise. Heart rate (HR) rapidly increased until 3 min and showed a steady state in moderate exercise. HR at 30 min was significantly higher than that at 3 min in moderate exercise. HR rapidly increased until 3 min and then gradually but significantly increased in heavy exercise. Increase in total Hb was not significantly related with HR after 3 min of exercise when HR was around 120 beats per min in moderate exercise. Increase in total Hb was significantly related with HR from 3 min to 10 min in the heavy exercise (correlation coefficients ranged from 0.959 to 0.702). It is concluded that an increase in the blood volume in skin plus active muscle is not simply associated with HR drift.

  7. Usefulness of Intravital Multiphoton Microscopy in Visualizing Study of Mouse Cochlea and Volume Changes in the Scala Media

    Directory of Open Access Journals (Sweden)

    Hyun Mi Ju

    2017-07-01

    Full Text Available Conventional microscopy has limitations in viewing the cochlear microstructures due to three-dimensional spiral structure and the overlying bone. But these issues can be overcome by imaging the cochlea in vitro with intravital multiphoton microscopy (MPM. By using near-infrared lasers for multiphoton excitation, intravital MPM can detect endogenous fluorescence and second harmonic generation of tissues. In this study, we used intravital MPM to visualize various cochlear microstructures without any staining and non-invasively analyze the volume changes of the scala media (SM without removing the overlying cochlear bone. The intravital MPM images revealed various tissue types, ranging from thin membranes to dense bone, as well as the spiral ganglion beneath the cochlear bone. The two-dimensional, cross-sectional, and serial z-stack intravital MPM images also revealed the spatial dilation of the SM in the temporal bone of pendrin-deficient mice. These findings suggest that intravital MPM might serve as a new method for obtaining microanatomical information regarding the cochlea, similar to standard histopathological analyses in the animal study for the cochlea. Given the capability of intravital MPM for detecting an increase in the volume of the SM in pendrin-deficient mice, it might be a promising new tool for assessing the pathophysiology of hearing loss in the future.

  8. The neural correlates of crowding-induced changes in appearance

    National Research Council Canada - National Science Library

    Anderson, Elaine J; Dakin, Steven C; Schwarzkopf, D Samuel; Rees, Geraint; Greenwood, John A

    2012-01-01

    .... Despite its severity, little is known about the cortical locus of crowding. Here, we examined the neural correlates of crowding by combining event-related fMRI adaptation with a change-detection paradigm...

  9. Climate induced changes in beach morphology and sediment dynamics, Machilipatnam

    Digital Repository Service at National Institute of Oceanography (India)

    Chauhan, O.S.

    The wave climate, littoral current patterns, monthly and seasonal longshore drift rates, beach profile changes, and sediment budget of the beach sediments were determined along Machilipatnam, Andhra Pradesh (India) for the NE, SW monsoons...

  10. A Study on the gas productivity by using Experimental Results of Stress-induced Permeability Change in Coal Seam

    Science.gov (United States)

    Kang, I. O.; Kim, K. H.; Han, J. M.; Lee, S. M.

    2016-12-01

    Methane Production from coal has become one of the more interesting practices in recent years to produce hydrocarbons. In the United States in 2005, it is estimated that 11% of all gas produced is from coalbed. The permeability is a measure of the capability of a porous medium to transmit fluid thought a network of microscopic channels. The permeability in coal is a direct function of the cleat volume. Since the volume of cleat changes with effect on the effective stress and sorption characteristics for production duration, the permeability also produces the alteration. Thus, to definitely estimate the gas production ability of the coal, it is essential that we especially understand changing aspects of permeability for production duration. Many researchers suggested the empirical equation to describe the effect of matrix shrinkage and effective stress. However, the past research associated with permeability change in coal focused on experimental results at a certain temperature.In this study, we have investigated the change of the sorption-induced permeability in pressure change with depth, an experimental approach considering temperature influence at the certain depth may be followed. Based on the received core from CBM field, we conducted the experiment both sorption and permeability according to the various pressure and temperatures.Firstly, experiment of the CH4 sorption was performed in the temperature ranged from 59℉ to 113℉ in the pressure ranges from 14.7 psia to 1,299 psia. Ot was found that CH3 isotherms display a normal Langmuir-type behavior from experiment ranges. In order to understand the effect of adsorption of CH4 in the change of sorption-induced permeability, we measured the permeability at the various pressures. When the pressure was increased by 100 psia, the results showed that the permeability alteration rate was 9.7% in reduction. Meanwhile, the permeability change rate was higher for a better affinity gas at lower temperature. Based on

  11. Ion induced changes in the structure of bordered pit membranes.

    Science.gov (United States)

    Lee, Jinkee; Holbrook, N Michele; Zwieniecki, Maciej A

    2012-01-01

    Ion-mediated changes in xylem hydraulic resistance are hypothesized to result from hydrogel like properties of pectins located in the bordered pit membranes separating adjacent xylem vessels. Although the kinetics of the ion-mediated changes in hydraulic resistance are consistent with the swelling/deswelling behavior of pectins, there is no direct evidence of this activity. In this report we use atomic force microscopy (AFM) to investigate structural changes in bordered pit membranes associated with changes in the ionic concentration of the surrounding solution. When submerged in de-ionized water, AFM revealed bordered pit membranes as relatively smooth, soft, and lacking any sharp edges surface, in contrast to pictures from scanning electron microscope (SEM) or AFM performed on air-dry material. Exposure of the bordered pit membranes to 50 mM KCl solution resulted in significant changes in both surface physical properties and elevation features. Specifically, bordered pit membranes became harder and the fiber edges were clearly visible. In addition, the membrane contracted and appeared much rougher due to exposed microfibers. In neither solution was there any evidence of discrete pores through the membrane whose dimensions were altered in response to the ionic composition of the surrounding solution. Instead the variable hydraulic resistance appears to involve changes in the both the permeability and the thickness of the pit membrane.

  12. Changes in gray matter induced by learning--revisited.

    Directory of Open Access Journals (Sweden)

    Joenna Driemeyer

    Full Text Available BACKGROUND: Recently, activation-dependant structural brain plasticity in humans has been demonstrated in adults after three months of training a visio-motor skill. Learning three-ball cascade juggling was associated with a transient and highly selective increase in brain gray matter in the occipito-temporal cortex comprising the motion sensitive area hMT/V5 bilaterally. However, the exact time-scale of usage-dependant structural changes occur is still unknown. A better understanding of the temporal parameters may help to elucidate to what extent this type of cortical plasticity contributes to fast adapting cortical processes that may be relevant to learning. PRINCIPAL FINDINGS: Using a 3 Tesla scanner and monitoring whole brain structure we repeated and extended our original study in 20 healthy adult volunteers, focussing on the temporal aspects of the structural changes and investigated whether these changes are performance or exercise dependant. The data confirmed our earlier observation using a mean effects analysis and in addition showed that learning to juggle can alter gray matter in the occipito-temporal cortex as early as after 7 days of training. Neither performance nor exercise alone could explain these changes. CONCLUSION: We suggest that the qualitative change (i.e. learning of a new task is more critical for the brain to change its structure than continued training of an already-learned task.

  13. Ion induced changes in the structure of bordered pit membranes

    Directory of Open Access Journals (Sweden)

    Jinkee eLee

    2012-03-01

    Full Text Available Xylem hydraulic resistance varies with ion concentration in sap solution. It is assumed that this variation in resistance results from hydrogel like properties of pectins located in bordered pit membranes separating adjacent vessels. Although kinetics of the resistance change suggests swelling/deswelling behavior of the pectins, there is no direct evidence of this activity. In this report we provide evidence of structural changes in bordered pit membranes responding to variation in ionic concentration of solute around it using atomic force microscopy (AFM. AFM revealed bordered pit membranes as relatively smooth, soft and lacking any sharp edges surface when submerged in de-ionized water, in contrast to pictures from scanning electron microscope (SEM or AFM performed on air dry material. Exposure of the bordered pit membranes to 50 mM KCl solution resulted in significant changes in both surface physical properties with and elevation features as bordered pit membrane became harder, with visible edges of fibers and collapsed, while no change in porosity was observed. Analysis suggests a need for a major shift in our understanding to the physical bases of variable xylem resistance from change in porosity to change in pathway length. Findings support the role of actuating properties of hybrid hydrogel-cellulose materials in water redistribution and embolism resistance.

  14. Training-induced changes in membrane transport proteins of human skeletal muscle

    DEFF Research Database (Denmark)

    Juel, C.

    2006-01-01

    for 6-8 weeks substantially increases the density of membrane proteins, whereas years of training (as performed by athletes) have no further effect. Studies suggest that training-induced changes at the protein level are important functionally. The underlying factors responsible for these changes......Training improves human physical performance by inducing structural and cardiovascular changes, metabolic changes, and changes in the density of membrane transport proteins. This review focuses on the training-induced changes in proteins involved in sarcolemmal membrane transport. It is concluded...... that the same type of training affects many transport proteins, suggesting that all transport proteins increase with training, and that both sprint and endurance training in humans increase the density of most membrane transport proteins. There seems to be an upper limit for these changes: intense training...

  15. Molecular Mechanisms for Exercise Training-Induced Changes in Vascular Structure and Function: Skeletal Muscle, Cardiac Muscle, and the Brain.

    Science.gov (United States)

    Olver, T Dylan; Ferguson, Brian S; Laughlin, M Harold

    2015-01-01

    Compared with resting conditions, during incremental exercise, cardiac output in humans is elevated from ~5 to 25 L min(-1). In conjunction with this increase, the proportion of cardiac output directed toward skeletal muscle increases from ~20% to 85%, while blood flow to cardiac muscle increases 500% and blood flow to specific brain structures increases nearly 200%. Based on existing evidence, researchers believe that blood flow in these tissues is matched to the increases in metabolic rate during exercise. This phenomenon, the matching of blood flow to metabolic requirement, is often referred to as functional hyperemia. This chapter summarizes mechanical and metabolic factors that regulate functional hyperemia as well as other exercise-induced signals, which are also potent stimuli for chronic adaptations in vascular biology. Repeated exposure to exercise-induced increases in shear stress and the induction of angiogenic factors alter vascular cell gene expression and mediate changes in vascular volume and blood flow control. The magnitude and regulation of this coordinated response appear to be tissue specific and coupled to other factors such as hypertrophy and hyperplasia. The cumulative effects of these adaptations contribute to increased exercise capacity, reduced relative challenge of a given submaximal exercise bout and ameliorated vascular outcomes in patient populations with pathological conditions. In the subsequent discussion, this chapter explores exercise as a regulator of vascular biology and summarizes the molecular mechanisms responsible for exercise training-induced changes in vascular structure and function in skeletal and cardiac muscle as well as the brain.

  16. Stress inducible proteomic changes in Capsicum annuum leaves.

    Science.gov (United States)

    Mahajan, Neha S; Mishra, Manasi; Tamhane, Vaijayanti A; Gupta, Vidya S; Giri, Ashok P

    2014-01-01

    Herbivore attack induces defense responses in plants, activating several signaling cascades. As a result, molecules deterrent to the herbivores are produced and accumulated in plants. Expression of defense mechanism/traits requires reorganization of the plant metabolism, redirecting the resources otherwise meant for growth. In the present work, protein profile of Capsicum annuum leaves was examined after herbivore attack/induction. Majority of proteins identified as differentially accumulated, were having roles in redox metabolism and photosynthesis. For example, superoxide dismutase and NADP oxidoreductase were upregulated by 10- and 6-fold while carbonic anhydrase and fructose-1,6-bisphosphatase were downregulated by 9- and 4-fold, respectively. Also, superoxide dismutase, NADPH quinone oxidoreductase and NADP dependent isocitrate dehydrogenase transcripts showed a higher accumulation in induced leaf tissues at early time points. In general, proteins having role in defense and damage repair were upregulated while those involved in photosynthesis appeared downregulated. Thus metabolic reconfiguration to balance defense and tolerance was evident in the stress-induced leaves.

  17. The influence of cross-linking and clustering upon the nanohole free volume of the SHI and γ-radiation induced polymeric material

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Paramjit [University School of Basic and Applied Sciences, Guru Gobind Singh Indraprastha University, New Delhi 110078 (India); Kumar, Rajesh, E-mail: rajeshkumaripu@gmail.com [University School of Basic and Applied Sciences, Guru Gobind Singh Indraprastha University, New Delhi 110078 (India); Singh, Rajinder [Department of Physics, Guru Nanak Dev University, Amritsar, Punjab 143005 (India); Roychowdhury, Anirban; Das, D. [UGC-DAE Consortium for Scientific Research, III/LB-8, Bidhannagar, Kolkata 700098 (India)

    2015-02-15

    Highlights: • Irradiated the PMMA with lithium ions and gamma radiations. • The study of modification of the nano-scale free volume by positron annihilation lifetime spectroscopy technique. • Structural, optical and chemical studies by XRD, UV–vis and FTIR, respectively. • Structural amorphization and decrease of the band gap energy was observed after ion and gamma exposure. • Change in the surface morphology studied by SEM. - Abstract: The effects of swift heavy ions and gamma radiations upon the nano-scale free volume of the polymethylemethacrylate (PMMA) polymer were investigated using positron annihilation lifetime spectroscopy. The polymer samples were (a) irradiated by 50 MeV Li{sup 3+} ion beam to the fluences ranging from 1 × 10{sup 11} to 5 × 10{sup 12} ions/cm{sup 2} and (b) exposed to gamma radiation at various doses ranging from 250 to 1000 kGy{sub .} The amorphization was observed in XRD study after ion irradiation and gamma exposure. The absorption edge in the UV–visible study shifted towards the higher wavelength regime leading to decrease of the band gap energy in both cases of irradiations. The formation of new bands at positions 1570, 1560 and 1542 cm{sup −1} were observed in FTIR study of gamma radiation exposed sample at 750 kGy. The cluster formation was seen in the SEM images. The nano-scale free volume (V{sub f}) of the Li{sup 3+} ions irradiated PMMA samples was observed to be decreased at fluences of 1.0 × 10{sup 11}, 5.0 × 10{sup 11} and 2.5 × 10{sup 12} ions/cm{sup 2} due to ion induced cross-linking of the polymeric chains. The values of hole radius (R) and V{sub f} were increased at fluence of 5.0 × 10{sup 12} ions/cm{sup 2}, it could be due to the clustering induced at higher fluences. The gamma exposures of the samples lead to decrease of the values of R and V{sub f}.

  18. RELATIONSHIP BETWEEN TRAINING VOLUME AND BONE MINERAL DENSITY CHANGES IN ELDERLY WOMEN

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    Juan José Rábade Espinosa

    Full Text Available ABSTRACT Introduction: Several studies have analyzed the relationship between physical activity and bone density. However, the prescription of exercise is not entirely clear as to the type, quantity and intensity. Objective: The objective of this study was to determine if there is a relationship between the amount of exercise and changes in bone mineral density. Methods: Fifty-two women, members of the Municipal Program of Physical Activity for Seniors, voluntarily underwent two ultrasonographies of the calcaneus within a 6-month interval. During this period, all physical activity was recorded. Afterwards, a lineal correlation study was carried out between the amount of exercise and bone changes, expressed as T-Score variation, first in total number of participants and then in groups. Considering the average body weight obtained for all women, two groups were created ("light" 69 kg. Later, women who had participated in less than 72% of the targeted program were excluded from both groups, and the differences between the groups "light and trained" and "heavy and trained" were analyzed. To do so, the nonparametric Mann-Whitney U test was used. Results: A significant relationship of r= -0.59 was found between the total amount of exercise and the T-Score variation in the group of women above 69 kg. Significant differences were found between the "light and trained" group and the "heavy and trained" group with respect to the variation of T-Score. Conclusion: The effect of exercise on bone mineral density is determined, somehow, by body weight. This interaction is due, possibly, to mechanical demands difference.

  19. Three-dimensional volume rendering of tibiofibular joint space and quantitative analysis of change in volume due to tibiofibular syndesmosis diastases

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    Taser, F.; Shafiq, Q.; Ebraheim, N.A. [Medical University of Ohio, Orthopaedic Surgery Department, Toledo, OH (United States)

    2006-12-15

    The diagnosis of ankle syndesmosis injuries is made by various imaging techniques. The present study was undertaken to examine whether the three-dimensional reconstruction of axial CT images and calculation of the volume of tibiofibular joint space enhances the sensitivity of diastases diagnoses or not. Six adult cadaveric ankle specimens were used for spiral CT-scan assessment of tibiofibular syndesmosis. After the specimens were dissected, external fixation was performed and diastases of 1, 2, and 3 mm was simulated by a precalibrated device. Helical CT scans were obtained with 1.0-mm slice thickness. The data was transferred to the computer software AcquariusNET. Then the contours of the tibiofibular syndesmosis joint space were outlined on each axial CT slice and the collection of these slices were stacked using the computer software AutoCAD 2005, according to the spatial arrangement and geometrical coordinates between each slice, to produce a three-dimensional reconstruction of the joint space. The area of each slice and the volume of the entire tibiofibular joint space were calculated. The tibiofibular joint space at the 10th-mm slice level was also measured on axial CT scan