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Sample records for volume variation svv

  1. Noninvasively derived stroke volume variation by finger volume clamping can reliably predict fluid responsiveness

    NARCIS (Netherlands)

    Vos, Jaap Jan; Poterman, Marieke; Struys, Michel; Scheeren, Thomas; Kalmar, A.F.

    2013-01-01

    Background and Goal of Study:  Dynamic preload variables derived from the arterial pressure waveform have been shown to accurately predict fluid responsiveness in mechanically ventilated patients. One of these variables, stroke volume variation (SVV), can also be obtained noninvasively by the finger

  2. Stroke volume variation and pleth variability index to predict fluid responsiveness during resection of primary retroperitoneal tumors in Hans Chinese.

    Science.gov (United States)

    Fu, Q; Mi, W D; Zhang, H

    2012-02-01

    Respiration variation in arterial pulse pressure (ΔPP) and pulse oximetry plethysmographic waveform amplitude (ΔPOP) are accurate predictors of fluid responsiveness in mechanically ventilated patients. We hypothesized that stroke volume variation (SVV) and pleth variability index (PVI) can predict fluid responsiveness in mechanically ventilated patients during major surgical procedures in Hans Chinese. This prospective study consisted of fifty-five Hans Chinese patients undergoing resection of primary retroperitoneal tumors (PRPT). During the surgical procedures, hemodynamic data [central venous pressure (CVP), cardiac index (CI), stroke volume index (SVI), SVV, and PVI] were recorded before and after volume expansion (VE) (8 ml•kg-1 of 6% hydroxyethyl starch 130/0.4). Fluid responsiveness was defined as an increase in SVI ≥ 10% after VE. Four patients were excluded from analysis for arrhythmia or obvious hemorrhage during VE. Baseline SVV correlated well with baseline PVI and the changes in SVV was correlated with the changes in PVI (p Chinese.

  3. Stroke volume variation does not predict fluid responsiveness in patients with septic shock on pressure support ventilation

    DEFF Research Database (Denmark)

    Perner, A; Faber, T

    2006-01-01

    Stroke volume variation (SVV)--as measured by the pulse contour cardiac output (PiCCO) system--predicts the cardiac output response to a fluid challenge in patients on controlled ventilation. Whether this applies to patients on pressure support ventilation is unknown....

  4. Zielgerichtete Volumentherapie durch Optimierung von Schlagvolumen (variation) bei Hochrisikoeingriffen : eine randomisierte kontrollierte Multicenter Pilotstudie

    NARCIS (Netherlands)

    Scheeren, Thomas; Wiesenack, Christoph; Gerlach, H.; Marx, G.

    2011-01-01

    Subject: Perioperative hemodynamic optimization reduces the incidence of postoperative complications in patients after high-risk interventions. We investigated the influence of a targeted, individualized intraoperative volume therapy, based on measurements of stroke volume variation (SVV) and stroke

  5. Goal-directed intraoperative fluid therapy guided by stroke volume and its variation in high-risk surgical patients : a prospective randomized multicentre study

    NARCIS (Netherlands)

    Scheeren, Thomas W. L.; Wiesenack, Christoph; Gerlach, Herwig; Marx, Gernot

    2013-01-01

    Perioperative hemodynamic optimisation improves postoperative outcome for patients undergoing high-risk surgery (HRS). In this prospective randomized multicentre study we studied the effects of an individualized, goal-directed fluid management based on continuous stroke volume variation (SVV) and st

  6. Goal-Directed Fluid Therapy Using Stroke Volume Variation Does Not Result in Pulmonary Fluid Overload in Thoracic Surgery Requiring One-Lung Ventilation

    Directory of Open Access Journals (Sweden)

    Sebastian Haas

    2012-01-01

    Full Text Available Background. Goal-directed fluid therapy (GDT guided by functional parameters of preload, such as stroke volume variation (SVV, seems to optimize hemodynamics and possibly improves clinical outcome. However, this strategy is believed to be rather fluid aggressive, and, furthermore, during surgery requiring thoracotomy, the ability of SVV to predict volume responsiveness has raised some controversy. So far it is not known whether GDT is associated with pulmonary fluid overload and a deleterious reduction in pulmonary function in thoracic surgery requiring one-lung-ventilation (OLV. Therefore, we assessed the perioperative course of extravascular lung water index (EVLWI and paO2/FiO2-ratio during and after thoracic surgery requiring lateral thoracotomy and OLV to evaluate the hypothesis that fluid therapy guided by SVV results in pulmonary fluid overload. Methods. A total of 27 patients (group T were enrolled in this prospective study with 11 patients undergoing lung surgery (group L and 16 patients undergoing esophagectomy (group E. Goal-directed fluid management was guided by SVV (SVV 0.05 in EVLWI during the observation period (BL: 7.8 ± 2.5, 24postop: 8.1 ± 2.4 mL/kg. A subgroup analysis for group L and group E also did not reveal significant changes of EVLWI. The paO2/FiO2-ratio decreased significantly during the observation period (group L: BL: 462 ± 140, OLVterm15: 338 ± 112 mmHg; group E: BL: 389 ± 101, 24postop: 303 ± 74 mmHg but remained >300 mmHg except during OLV. Conclusions. SVV-guided fluid management in thoracic surgery requiring lateral thoracotomy and one-lung ventilation does not result in pulmonary fluid overload. Although oxygenation was reduced, pulmonary function remained within a clinically acceptable range.

  7. Correlation between stroke volume variation and blood volume during hypovolemia%低血容量状态下患者每搏量变异度与血容量的相关性

    Institute of Scientific and Technical Information of China (English)

    李文静; 李健; 彭科

    2014-01-01

    Objective To investigate the correlation between stroke volume variation (SVV) and blood volume during hypovolemia.Methods Twenty ASA Ⅰ or Ⅱ patients,aged 20-64 years,with body mass index (BMI) of 20-30 kg/m2,scheduled for elective orthopedic operation were enrolled in this study.Anesthesia was induced with dexamethasone,midazolam,propofol,fentanyl and cisatracurium,and maintained with sevoflurane,fentanyl and cisatracurium.Then the patients received endotracheal intubation and mechanical ventilation.Heart rate (HR),mean arterial blood pressure (MAP),central venous pressure (CVP),arterial pressure-based cardiac output (APCO),SW,systemic vascular resistance (SVR) and cardiac index (Cl) were recorded 5 minutes after endotracheal intubation.Blood was taken from the central vein at a rate of 30-50 ml/min and the volume was 5% of the whole blood volume,and then haemodynamic parameters mentioned above were recorded after the haemodynamics were kept stable for 5 minutes.Blood was taken again with the method mentioned above and the haemodynamic parameters were recorded.Then 6% hydroxyethyl starch (HES) 130/0.4 was infused at 50-70 ml/min via the right internal jugular vein,and the volume was equal to 5% of the whole blood volume,and then haemodynamic parameters were recorded after the haemodynamics was kept stable for 5 minutes.Fluid replacement was performed again using the method mentioned above and the haemodynamic parameters were recorded.Linear correlation of the changes in blood volume (difference between the blood volume at each time point and the baseline value) with dSVV (difference between the value monitored at each time point and the baseline value) was analyzed.Results Significant changes were found in SW,APCO and Cl after each change in blood volume (P < 0.05 or 0.01),while no significant changes were found in HR,MAP,CVP and SVR after each change in blood volume.The change in blood volume was negatively correlated with dSVV (r =-0.875,P < 0

  8. Value of three hemodynamic parameters in evaluating volume status under artificial pneumoperitoneum and their correlation

    Directory of Open Access Journals (Sweden)

    Xiao-mei LIU

    2014-08-01

    Full Text Available Objective To explore the value of stroke volume variation (SVV, pulse pressure variation (PPV and pleth variability index (PVI in evaluating the volume status under pneumoperitoneum and their correlation. Methods Twenty-six patients with stomach cancer receiving laparoscopy-assisted radical gastrectomy under general anesthesia were involved in this study. The indexes of SVV, PPV and PVI were monitored continuously after general anesthesia. A volume loading test was performed after pneumoperitoneum, and the hemodynamic parameters were determined before and after fluid infusion (6% HES, 7ml/kg, and the patients were divided into response group (n=16 and non-response group (n=10 according to whether the increase in stroke volume index (ΔSVI was ≥15% or not. The receiver operator characteristic (ROC curves of SVV, PPV and PVI were drawn to evaluate the value of SVV, PPV and PVI in evaluating volume status under artificial pneumoper itoneum and the correlation between them. Results The analysis of ROC curves showed that SVV, PPV and PVI could all be used to estimate the volume status effectively, the area under the curve (AUC of them was 0.978, 0.963 and 0.928 respectively, and there was a significant correlation between the three parameters (SVV and PPV: r=0.921, P<0.01; SVV and PVI: r=0.686, P<0.01; PPV and PVI: r=0.577, P<0.01. Conclusion SVV, PPV and PVI could be used to accurately evaluate the volume status under artificial pneumoperitoneum, and there is a good correlation between them. DOI: 10.11855/j.issn.0577-7402.2014.07.08

  9. Application of stroke volume variation in directing management of elderly septic shock patients%每搏量变异度在老年脓毒性休克患者中的应用

    Institute of Scientific and Technical Information of China (English)

    王志; 汤卫兵; 刘野

    2015-01-01

    目的:探讨每搏量变异度(SVV)在老年脓毒性休克患者中的应用。方法将进行机械通气的老年脓毒性休克患者28例分为常规组13例和SVV指导组15例,常规组根据中心静脉压(CVP)指导容量复苏,SVV指导组根据SVV、心输出量(CO)指导容量复苏。观察2组患者复苏时间、复苏后血乳酸、氧合指数、CVP、平均动脉压(MAP)、N端尿钠肽前体(NT-proB⁃NP)等变化,机械通气时间、24 h内左心功能不全发生率,28 d发生多器官功能障碍综合征(MODS)和死亡情况,记录SVV指导组复苏前后血流动力学参数SVV、CO、外周血管阻力(SVR)的变化。结果 SVV指导组复苏时间短于常规组(t=3.83),乳酸、NT-proBNP较常规组下降(t分别为3.20和12.32,P<0.05),氧合指数较常规组升高(t=3.01,P<0.05)。2组左心功能不全、MODS及病死率差异无统计学意义(P分别为0.198、0.410和0.372)。SVV指导组复苏后CO、SVV较复苏前改善(P<0.05)。结论 SVV能更好地指导老年脓毒性休克患者的容量复苏。%Objective To investigate the application of stroke volume variation (SVV) in directing management of elderly septic shock patients. Methods Patients who were diagnosed with elderly septic shock and supported with mechanical ventilation were in⁃cluded (n=28). They were divided into control group (n=13) and SVV group (n=15). Volume recovery was directed by CVP (central ve⁃nous pressure ) in control group and by SVV and CO (cardiac output) in SVV guoup respectively. Blood lactate, oxidation index, CVP , MVP, NT-proBNP, time of recovery, the length relying on mechanical ventilation and Vigileo parameters were compared after volume resuscition. During the period of treatment, the incidence of acute left ventricle dysfunction within 24 hours, MODS within 28 days and mortality rates of all causes were compared between these two groups. Changes in SVV, cardiac output (CO) and

  10. The role of stroke volume variation in predicting the volume responsiveness of patients with severe sepsis and septic shock%每搏量变异度预测严重感染和感染性休克患者容量反应性的价值

    Institute of Scientific and Technical Information of China (English)

    黄磊; 张卫星; 蔡文训; 罗华; 陈映群; 张声

    2010-01-01

    目的 研究每搏量变异度(stroke volume variation,SW)预测严重感染和感染性休克机械通气患者容量反应性的价值.方法 前瞻观察性研究,对2009年1月至2010年3月北京大学深圳医院ICU严重感染和感染性休克机械通气患者28例进行容量负荷试验.超声心输出量监测仪无创监测心脏指数(cardiac index,CI)、每搏输出量指数(stroke volume index,SVI)、外周血管阻力(systemic vascular resistance,SVR)、SVV等血流动力学指标.根据容量负荷试验前后CI增加值是否大于12%分为有反应组和无反应组,组间比较应用两独立样本t检验;容量负荷试验前后比较应用配对t检验;受试者工作特征曲线评价SVV、中心静脉压(central venous pressure,CVP)以及容量负荷试验前后CVP变化值(△CVP)预测容量反应性的价值.结果 容量负荷试验前,有反应组SW高于无反应组[(18.2±4.7)%和(12.7±4.2)%,P=0.003];而CVP两组差异无统计学意义[(10.2±4.0)cmH2O和(10.8±4.8)cmH2O,P>0.05].容量负荷试验后,有反应组△CVP低于无反应组[(2.9±3.1)cmH2O和(5.3±2.7)cmH2O,P=0.037].SVV、CVP和△CVP的曲线下面积(AUC)分别是0.836(95%CI:0.680~0.992,P=0.003)、0.549(95%CI:0.329~0.768,P=0.662)和0.762(95%CI:0.570~0.953,P=0.019).SVV为15.5%时预测容量反应性的敏感度和特异度分别是84.6%和80%.结论 SVV预测严重感染和感染性休克机械通气患者的容量反应性具有良好价值,明显优于CVP、△CVP等传统指标.%Objective To assess the role of stroke volume variation (SVV) in predicting the volume responsiveness of mechanically ventilated patients with severe sepsis and septic shock. Method A total of 28 mechanically ventilated patients with severe sepsis and septic shock were admitted from January 2009 to March 2010. Every patient was treated with volume loading test. Cardiac index (CI), stroke volume index (SVI), systemic vascular resistance (SVR) and SVV were measured non-invasively by

  11. Effect of lung protection strategy on stroke volume variation in patients undergoing open-chest operation%肺保护策略对胸外科手术患者每搏量变异度的影响

    Institute of Scientific and Technical Information of China (English)

    陆珠凤; 葛圣金; 薛张纲; 邓小明

    2012-01-01

    目的 探讨肺保护策略对择期行胸外科手术患者每搏量变异度(SVV)的影响.方法 选择20例择期行开胸手术的患者,ASA分级Ⅰ~Ⅱ级,均无术前用药.研究患者清醒平卧位自主呼吸(T1)、清醒侧卧位自主呼吸(T2)、单纯全麻平卧位双肺通气(T3)、单纯全麻平卧位肺保护策略下单肺通气(T4)、单纯全麻侧卧位双肺通气(T5)、单纯全麻侧卧位肺保护策略下单肺通气(T6)、联合麻醉肺保护策略下单肺通气切皮时(T7)以及联合麻醉肺保护策略下单肺通气切开胸膜时(T8)的心率(HR)、平均动脉压(MAP)、SVV、心脏指数(CI)4个血流动力学指标的变化,以及SVV变化与HR、MAP、CI的相关性.4个指标数据组内采用单因素方差分析,根据方差齐性检验结果决定进一步统计学检验方案,4个数据组间采用Pearson相关分析.结果 单因素方差分析结果显示,T1~T8时间点SVV、HR变化差异无统计学意义(P>0.05),MAP、CI的变化差异有统计学意义(P<0.05);方差齐性LSD多重比较结果显示,SVV在T2时间点与T5时间点之间,CI在T1时间点与T3~T8时间点之间,CI在T2时间点与T4时间点、T6~T8时间点之间,MAP在T1时间点与T3~T4时间点、T6~T8时间点之间,MAP在T2时间点与T3~T4时间点、T6~T8时间点之间,MAP在T4时间点与T5时间点之间差异有统计学意义(P<0.05).相关分析结果显示SVV与CI呈负相关(r=-0.267,P=0.018).结论 术前无容量不足的患者体位改变(从仰卧位到侧卧位)对SVV和HR无显著影响;肺保护策略下单肺通气对SVV、HR、MAP和CI均无显著影响;麻醉因素可引起MAP和CI明显下降,且麻醉状态下被动翻身动作可引起MAP和CI升高,SVV变化与CI呈负相关,但相关性较弱.%Objective To investigate the effect of lung-protective ventilation mode on stroke volume variation (SVV) in patients receiving selected thoracotomy. Methods Twenty patients of the American

  12. Applying dynamic parameters to predict hemodynamic response to volume expansion in spontaneously breathing patients with septic shock.

    Science.gov (United States)

    Lanspa, Michael J; Grissom, Colin K; Hirshberg, Eliotte L; Jones, Jason P; Brown, Samuel M

    2013-02-01

    Volume expansion is a mainstay of therapy in septic shock, although its effect is difficult to predict using conventional measurements. Dynamic parameters, which vary with respiratory changes, appear to predict hemodynamic response to fluid challenge in mechanically ventilated, paralyzed patients. Whether they predict response in patients who are free from mechanical ventilation is unknown. We hypothesized that dynamic parameters would be predictive in patients not receiving mechanical ventilation. This is a prospective, observational, pilot study. Patients with early septic shock and who were not receiving mechanical ventilation received 10-mL/kg volume expansion (VE) at their treating physician's discretion after initial resuscitation in the emergency department. We used transthoracic echocardiography to measure vena cava collapsibility index and aortic velocity variation before VE. We used a pulse contour analysis device to measure stroke volume variation (SVV). Cardiac index was measured immediately before and after VE using transthoracic echocardiography. Hemodynamic response was defined as an increase in cardiac index 15% or greater. Fourteen patients received VE, five of whom demonstrated a hemodynamic response. Vena cava collapsibility index and SVV were predictive (area under the curve = 0.83, 0.92, respectively). Optimal thresholds were calculated: vena cava collapsibility index, 15% or greater (positive predictive value, 62%; negative predictive value, 100%; P = 0.03); SVV, 17% or greater (positive predictive value 100%, negative predictive value 82%, P = 0.03). Aortic velocity variation was not predictive. Vena cava collapsibility index and SVV predict hemodynamic response to fluid challenge patients with septic shock who are not mechanically ventilated. Optimal thresholds differ from those described in mechanically ventilated patients.

  13. Applying dynamic parameters to predict hemodynamic response to volume expansion in spontaneously breathing patients with septic shock

    Science.gov (United States)

    Lanspa, Michael J.; Grissom, Colin K.; Hirshberg, Eliotte L.; Jones, Jason P.; Brown, Samuel M.

    2013-01-01

    Background Volume expansion is a mainstay of therapy in septic shock, although its effect is difficult to predict using conventional measurements. Dynamic parameters, which vary with respiratory changes, appear to predict hemodynamic response to fluid challenge in mechanically ventilated, paralyzed patients. Whether they predict response in patients who are free from mechanical ventilation is unknown. We hypothesized that dynamic parameters would be predictive in patients not receiving mechanical ventilation. Methods This is a prospective, observational, pilot study. Patients with early septic shock and who were not receiving mechanical ventilation received 10 ml/kg volume expansion (VE) at their treating physician's discretion after initial resuscitation in the emergency department. We used transthoracic echocardiography to measure vena cava collapsibility index (VCCI) and aortic velocity variation (AoVV) prior to VE. We used a pulse contour analysis device to measure stroke volume variation (SVV). Cardiac index was measured immediately before and after VE using transthoracic echocardiography. Hemodynamic response was defined as an increase in cardiac index ≥ 15%. Results 14 patients received VE, 5 of which demonstrated a hemodynamic response. VCCI and SVV were predictive (Area under curve = 0.83, 0.92, respectively). Optimal thresholds were calculated: VCCI ≥ 15% (Positive predictive value, PPV 62%, negative predictive value, NPV 100%, p = 0.03); SVV ≥ 17% (PPV 100%, NPV 82%, p = 0.03). AoVV was not predictive. Conclusions VCCI and SVV predict hemodynamic response to fluid challenge patients with septic shock who are not mechanically ventilated. Optimal thresholds differ from those described in mechanically ventilated patients. PMID:23324885

  14. Volume variation of Gruneisen parameters of fcc transition metals

    Indian Academy of Sciences (India)

    C V Pandya; P R Vyas; T C Pandya; V B Gohel

    2002-02-01

    The volume variation of the Gruneisen parameters of ten fcc transition metals, up to 40% compression, has been studied on the basis of a model approach proposed by Antonov et al. The results are reasonably good for six metals except for Rh, Ag, Au and Ni when compared with available experimental and other theoretical values. The model requires an appropriate modification for Rh, Ag, Au and Ni.

  15. Moderate intensity supine exercise causes decreased cardiac volumes and increased outer volume variations: a cardiovascular magnetic resonance study

    DEFF Research Database (Denmark)

    Steding-Ehrenborg, Katarina; Jablonowski, Robert; Arvidsson, Per M;

    2013-01-01

    The effects on left and right ventricular (LV, RV) volumes during physical exercise remains controversial. Furthermore, no previous study has investigated the effects of exercise on longitudinal contribution to stroke volume (SV) and the outer volume variation of the heart. The aim of this study...

  16. The value of volume reaction evaluation through stroke volume variation combined with passive leg test for septic shock patients with autonomous breathing%每搏量变异结合被动抬腿试验在自主呼吸感染性休克患者容量反应评估中的价值研究

    Institute of Scientific and Technical Information of China (English)

    林冰; 蒋丽芳; 孟繁甦; 郭应军

    2014-01-01

    Objective To evaluate the value of PLR-△SVV for the septic shock patients with autonomous breathing. Methods 60 patients were included in the study. Hemodynamic data of PICCO were collected before and after treatment. After rehydration, the group (△SV≥10%) was defined volume responder group, and then the predictive value of PLR-△SVV was analyzed. Results Compared with the nonresponders group, PLR-△SVV was increased significantly in response group[(10 ± 4)mL vs (14 ± 6)mL,P<0.05]. The ROC curve for PLR-△SVV were 0.881, and the sensitivity was 85.7%, the specificity was 92.0%. Conclusion PLR-△SVV can be used to predict fluid responsiveness for septic shock patients with spontaneously breathing.%目的:评估被动抬腿试验(passive leg raising,PLR)后每搏量变异(stroke volume variation,SVV),即PLR-△SVV在自主呼吸感染性休克患者中容量反应的预测价值。方法:患者60例,用 PiCCO 监测 PLR和补液试验前后的血流动力学,补液试验后△SV(stroke volume)≥10%为容量反应组,评价PLR-△SVV预测容量反应的价值。结果:反应组PLR-△SVV明显变化[(10±4)mL vs (14±6)mL,P<0.05],无反应组无明显变化(P>0.05)。 PLR-△SVV预测容量反应的ROC曲线下面积为0.881。以PLR-△SVV≥11.2%评价容量反应性,灵敏度为85.7%,特异度为92.0%。结论:PLR-△SVV可预测自主呼吸感染性休克患者的容量反应。

  17. A simple physiologic algorithm for managing hemodynamics using stroke volume and stroke volume variation: physiologic optimization program.

    Science.gov (United States)

    McGee, William T

    2009-01-01

    Intravascular volume status and volume responsiveness continue to be important questions for the management of critically ill or injured patients. Goal-directed hemodynamic therapy has been shown to be of benefit to patients with severe sepsis and septic shock, acute lung injury and adult respiratory distress syndrome, and for surgical patients in the operating room. Static measures of fluid status, central venous pressure (CVP), and pulmonary artery occlusion pressure (PAOP) are not useful in predicting volume responsiveness. Stroke volume variation and pulse pressure variation related to changes in stroke volume during positive pressure ventilation predict fluid responsiveness and represent an evolving practice for volume management in the intensive care unit (ICU) or operating room. Adoption of dynamic parameters for volume management has been inconsistent. This manuscript reviews some of the basic physiology regarding the use of stroke volume variation to predict fluid responsiveness in the ICU and operating room. A management algorithm using this physiology is proposed for the critically ill or injured in various settings.

  18. Pulse pressure variation and stroke volume variation under different inhaled concentrations of isoflurane, sevoflurane and desflurane in pigs undergoing hemorrhage

    Directory of Open Access Journals (Sweden)

    Alexandre Hideaki Oshiro

    2015-12-01

    Full Text Available OBJECTIVES: Inhalant anesthesia induces dose-dependent cardiovascular depression, but whether fluid responsiveness is differentially influenced by the inhalant agent and plasma volemia remains unknown. The aim of this study was to compare the effects of isoflurane, sevoflurane and desflurane on pulse pressure variation and stroke volume variation in pigs undergoing hemorrhage. METHODS: Twenty-five pigs were randomly anesthetized with isoflurane, sevoflurane or desflurane. Hemodynamic and echocardiographic data were registered sequentially at minimum alveolar concentrations of 1.00 (M1, 1.25 (M2, and 1.00 (M3. Then, following withdrawal of 30% of the estimated blood volume, these data were registered at a minimum alveolar concentrations of 1.00 (M4 and 1.25 (M5. RESULTS: The minimum alveolar concentration increase from 1.00 to 1.25 (M2 decreased the cardiac index and increased the central venous pressure, but only modest changes in mean arterial pressure, pulse pressure variation and stroke volume variation were observed in all groups from M1 to M2. A significant decrease in mean arterial pressure was only observed with desflurane. Following blood loss (M4, pulse pressure variation, stroke volume variation and central venous pressure increased (p <0.001 and mean arterial pressure decreased in all groups. Under hypovolemia, the cardiac index decreased with the increase of anesthesia depth in a similar manner in all groups. CONCLUSION: The effects of desflurane, sevoflurane and isoflurane on pulse pressure variation and stroke volume variation were not different during normovolemia or hypovolemia.

  19. Harnessing Linguistic Variation to Improve Education. Rethinking Education. Volume 5

    Science.gov (United States)

    Yiakoumetti, Androula, Ed.

    2012-01-01

    This volume brings together research carried out in a variety of geographic and linguistic contexts including Africa, Asia, Australia, Canada, the Caribbean, Europe and the United States and explores efforts to incorporate linguistic diversity into education and to "harness" this diversity for learners' benefit. It challenges the largely…

  20. Variation in Measurements of Transtibial Stump Model Volume A Comparison of Five Methods

    NARCIS (Netherlands)

    Bolt, A.; de Boer-Wilzing, V. G.; Geertzen, J. H. B.; Emmelot, C. H.; Baars, E. C. T.; Dijkstra, P. U.

    2010-01-01

    Objective: To determine the right moment for fitting the first prosthesis, it is necessary to know when the volume of the stump has stabilized. The aim of this study is to analyze variation in measurements of transtibial stump model volumes using the water immersion method, the Design TT system, the

  1. Compact high order finite volume method on unstructured grids III: Variational reconstruction

    Science.gov (United States)

    Wang, Qian; Ren, Yu-Xin; Pan, Jianhua; Li, Wanai

    2017-05-01

    This paper presents a variational reconstruction for the high order finite volume method in solving the two-dimensional Navier-Stokes equations on arbitrary unstructured grids. In the variational reconstruction, an interfacial jump integration is defined to measure the jumps of the reconstruction polynomial and its spatial derivatives on each cell interface. The system of linear equations to determine the reconstruction polynomials is derived by minimizing the total interfacial jump integration in the computational domain using the variational method. On each control volume, the derived equations are implicit relations between the coefficients of the reconstruction polynomials defined on a compact stencil involving only the current cell and its direct face-neighbors. The reconstruction and time integration coupled iteration method proposed in our previous paper is used to achieve high computational efficiency. A problem-independent shock detector and the WBAP limiter are used to suppress non-physical oscillations in the simulation of flow with discontinuities. The advantages of the finite volume method using the variational reconstruction over the compact least-squares finite volume method proposed in our previous papers are higher accuracy, higher computational efficiency, more flexible boundary treatment and non-singularity of the reconstruction matrix. A number of numerical test cases are solved to verify the accuracy, efficiency and shock-capturing capability of the finite volume method using the variational reconstruction.

  2. Stroke volume variation compared with pulse pressure variation and cardiac index changes for prediction of fluid responsiveness in mechanically ventilated patients

    Directory of Open Access Journals (Sweden)

    Randa Aly Soliman

    2015-04-01

    Conclusions: Baseline stroke volume variation ⩾8.15% predicted fluid responsiveness in mechanically ventilated patients with acute circulatory failure. The study also confirmed the ability of pulse pressure variation to predict fluid responsiveness.

  3. Total blood volume in the normally performing Standardbred trotter: age and sex variations.

    Science.gov (United States)

    Persson, S G; Funkquist, P; Nyman, G

    1996-03-01

    The purposes of this study were to elucidate the influences of age and sex on the mass specific blood volume parameters: total blood volume (TBV/BW, ml/kg), plasma volume (PV/ BW, ml/kg), total red cell volume (CV/BW, ml/kg) and maximal packed cell volume (PCV, l/l, i.e. after total mobilisation of the splenic red cell reservoir) and to establish reference values for these in normally performing Standardbred trotting race horses. In total 205 horses were studied. They were all, according to their owners and/or trainers, performing satisfactorily in racing or training for shortly impending racing. Blood volume determination was done with the Evans blue dye dilution technique after exercise induced emptying of the spleen. Both age and sex were found to influence variation of these parameters significantly, with the possible exception of PV/BW, whereas the primary variation appeared to be in CV/BW. It was concluded that taking age and sex dependent variations into consideration will render prediction of normal values for the blood volume parameters in the athletic Standardbred trotter more reliable and the detection of abnormal deviations more precise if five age and sex groups are used for comparisons.

  4. Inter-observer variation in ultrasound measurement of the volume and diameter of thyroid nodules

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Young Jun; Baek, Jung Hwan; Hong, Min Ji; Lee, Jeong Hyun [Dept. of Radiology, and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

    2015-06-15

    Thyroid nodule measurement using ultrasonography (US) is widely performed in various clinical scenarios. The purpose of this study was to evaluate inter-observer variation in US measurement of the volume and maximum diameter of thyroid nodules. This retrospective study included 73 consecutive patients with 85 well-defined thyroid nodules greater than 1 cm in their maximum diameter. US examinations were independently performed by using standardized measurement methods, conducted by two clinically experienced thyroid radiologists. The maximum nodule diameter and nodule volume, calculated from nodule diameters using the ellipsoid formula, were obtained by each reader. Inter-observer variations in volume and maximum diameter were determined using 95% Bland-Altman limits of agreement. The degree of inter-observer variations in volumes and the maximum diameters were compared using the Student's t test, between nodules < 2 cm in maximum diameter and those with > or = 2 cm. The mean inter-observer difference in measuring the nodule volume was -1.6%, in terms of percentage of the nodule volume, and the 95% limit of agreement was +/- 13.1%. For maximum nodule diameter, the mean inter-observer difference was -0.6%, in terms of percentage of the nodule diameter, and the 95% limit of agreement was +/- 7.3%. Inter-observer variation in volume was greater in nodules of < 2 cm in maximum diameter, compared to the larger nodules (p = 0.035). However, no statistically significant difference was noted between the two groups regarding maximum nodule diameters (p = 0.511). Any differences smaller than 13.1% and 7.3% in volume and maximum diameter, respectively, measured by using US for well-defined thyroid nodules of > 1 cm should not be considered as a real change in size.

  5. Large Variations in Ice Volume During the Middle Eocene "Doubthouse"

    Science.gov (United States)

    Dawber, C. F.; Tripati, A. K.

    2008-12-01

    The onset of glacial conditions in the Cenozoic is widely held to have begun ~34 million years ago, coincident with the Eocene-Oligocene boundary1. Warm and high pCO2 'greenhouse' intervals such as the Eocene are generally thought to be ice-free2. Yet the sequence stratigraphic record supports the occurrence of high-frequency sea-level change of tens of meters in the Middle and Late Eocene3, and large calcite and seawater δ18O excursions (~0.5-1.0 permil) have been reported in foraminifera from open ocean sediments4. As a result, the Middle Eocene is often considered the intermediary "doubthouse". The extent of continental ice during the 'doubthouse' is controversial, with estimates of glacioeustatic sea level fall ranging from 30 to 125m2,3,5. We present a new δ18Osw reconstruction for Ocean Drilling Project (ODP) Site 1209 in the tropical Pacific Ocean. It is the first continuous high-resolution record for an open-ocean site that is not directly influenced by changes in the carbonate compensation depth, which enables us to circumvent many of the limitations of existing records. Our record shows increases of 0.8 ± 0.2 (1 s.e) permil and 1.1 ± 0.2 permil at ~44-45 and ~42-41 Ma respectively, which suggests glacioeustatic sea level variations of ~90 m during the Middle Eocene. Modelling studies have shown that fully glaciating Antarctica during the Eocene should drive a change in seawater (δ18Osw) of 0.45 permil, and lower sea level by ~55 m6. Our results therefore support significant ice storage in both the Northern and Southern Hemisphere during the Middle Eocene 'doubthouse'. 1.Miller, Kenneth G. et al., 1990, Eocene-Oligocene sea-level changes in the New Jersey coastal plain linked to the deep-sea record. Geological Society of America Bulletin 102, 331-339 2.Pagani, M. et al., 2005, Marked decline in atmospheric carbon dioxide concentrations during the Paleogene. Science 309 (5734), 600-603. 3.Browning, J., Miller, K., and Pak, D., 1996, Global implications

  6. Post-traumatic stress and age variation in amygdala volumes among youth exposed to trauma.

    Science.gov (United States)

    Weems, Carl F; Klabunde, Megan; Russell, Justin D; Reiss, Allan L; Carrión, Victor G

    2015-12-01

    Theoretically, normal developmental variation in amygdala volumes may be altered under conditions of severe stress. The purpose of this article was to examine whether posttraumatic stress moderates the association between age and amygdala volumes in youth exposed to traumatic events who are experiencing symptoms of post-traumatic stress disorder (PTSD). Volumetric imaging was conducted on two groups of youth aged 9-17 years: 28 with exposure to trauma and PTSD symptoms (boys = 15, girls = 13) and 26 matched (age, IQ) comparison youth (Controls; boys = 12, girls = 14). There was a significant group by age interaction in predicting right amygdala volumes. A positive association between age and right amygdala volumes was observed, but only in PTSD youth. These associations with age remained when controlling for IQ, total brain volumes and sex. Moreover, older youth with PTSD symptoms had relatively larger right amygdala volumes than controls. Findings provide evidence that severe stress may influence age-related variation in amygdala volumes. Results further highlight the importance of utilizing age as an interactive variable in pediatric neuroimaging research, in so far as age may act as an important moderator of group differences.

  7. Bladder volume variations of cervical cancer patient in radiation therapy using ultrasonography

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Jong Ho [Dept. of Radiation Oncology, Pusan National University Hospital, Pusan (Korea, Republic of)

    2016-12-15

    The bladder volume change was measured using ultrasonography for helping decrease the side effects and other organ variations in the location of radiation therapy for cervical cancer patients. An experiment was performed targeting patients who were treated with radiation therapy at PNUH within the period from September to December 2015. To maintain the bladder volume, each patient was instructed to drink 500 cc water before and after CT simulation, 60 minutes before the dry run. Also, the bladder volume was measured in each patient CT scan, and a 3D conformal therapy plan was designed. The bladder volumes measured before and after the CT simulation, dry run, and radiation treatment planning were compared and analyzed. The average volume and average error of the bladder that were obtained from the measurement based on the CT scan images had the lowest standard deviation in the CT simulation. This means that the values that were obtained before and after the CT simulation were statistically relevant and correlative. Moreover, the bladder volume measured via ultrasonography was larger size, the average volume in the CT scan. But the values that were obtained Dry run and after the CT simulation were not statistically relevant. Drinking a certain amount of water helps a patient maintain his/her bladder volume for a dry run. Even then, it is difficult to maintain the bladder volume for the dry run. Also, whether or not the patients followed the directions for the dry run correctly is important.

  8. Image-guided radiotherapy of bladder cancer: bladder volume variation and its relation to margins

    DEFF Research Database (Denmark)

    Muren, Ludvig; Redpath, Anthony Thomas; Lord, Hannah

    2007-01-01

    BACKGROUND AND PURPOSE: To control and account for bladder motion is a major challenge in radiotherapy (RT) of bladder cancer. This study investigates the relation between bladder volume variation and margins in conformal and image-guided RT (IGRT) for this disease. MATERIALS AND METHODS: The cor...

  9. Hospital variation in 30-day mortality after colorectal cancer surgery in denmark: the contribution of hospital volume and patient characteristics

    DEFF Research Database (Denmark)

    Osler, Merete; Iversen, Lene Hjerrild; Borglykke, Anders

    2011-01-01

    This study examines variation between hospitals in 30-day mortality after surgery for colorectal cancer (CRC) in Denmark and explores whether hospital volume and patient characteristics contribute to any variation between hospitals.......This study examines variation between hospitals in 30-day mortality after surgery for colorectal cancer (CRC) in Denmark and explores whether hospital volume and patient characteristics contribute to any variation between hospitals....

  10. Evaluation of various Deformable Image Registrations for Point and Volume Variations

    CERN Document Server

    Han, Su Chul; Park, Seungwoo; Lee, Soon Sung; Jung, Haijo; Kim, Mi-Sook; Yoo, Hyung Jun; Ji, Young Hoon; Yi, Chul Young; Kim, Kum Bae

    2015-01-01

    The accuracy of deformable image registration (DIR) has a significant dosimetric impact in radiation treatment planning. We evaluated accuracy of various DIR algorithms using variations of the deformation point and volume. The reference image (Iref) and volume (Vref) was first generated with virtual deformation QA software (ImSimQA, Oncology System Limited, UK). We deformed Iref with axial movement of deformation point and Vref depending on the types of deformation that are the deformation1 is to increase the Vref (relaxation) and the deformation 2 is to decrease . The deformed image (Idef) and volume (Vdef) acquired by ImSimQA software were inversely deformed to Iref and Vref using DIR algorithms. As a result, we acquired deformed image (Iid) from Idef and volume (Vid) from Vdef. The DIR algorithms were the Horn Schunk optical flow (HS), Iterative Optical Flow (IOF), Modified Demons (MD) and Fast Demons (FD) with the Deformable Image Registration and Adaptive Radiotherapy Toolkit (DIRART) of MATLAB. The imag...

  11. Revisiting the returns-volume relationship: Time variation, alternative measures and the financial crisis

    Science.gov (United States)

    Cook, Steve; Watson, Duncan

    2017-03-01

    Following its introduction in the seminal study of Osborne (1959), a voluminous literature has emerged examining the returns-volume relationship for financial assets. The present paper revisits this relationship in an examination of the FTSE100 which extends the existing literature in two ways. First, alternative daily measures of the FTSE100 index are used to create differing returns and absolute returns series to employ in an examination of returns-volume causality. Second, rolling regression analysis is utilised to explore potential time variation in the returns-volume relationship. The findings obtained depict a hitherto unconsidered complexity in this relationship with the type of returns series considered and financial crisis found to be significant underlying factors. The implications of the newly derived results for both the understanding of the nature of the returns-volume relationship and the development of theories in connection to it are discussed.

  12. A prospective study of OAR volume variations between two different treatment planning systems in radiotherapy

    Directory of Open Access Journals (Sweden)

    Bhudevi Soubhagya Kulkarni

    2015-09-01

    Full Text Available Purpose: It has been seen that there is a clinically significant variation in the volume calculated across different planning systems for the same digital imaging and communication (DICOM contours.The purpose of this study is to investigate the difference in volumes of organs at risk when the structure sets were exported from the Eclipse ((Palo Alto, USA Version 10.0 to XIO CMS (Electa, Crawley, UK Version 4.40.00 treatment planning system (TPS and identify how the differences occur. Methods: We prospectively analyzed the volumes of organs at risk from computerized tomography (CT data of 54 patients. Head and neck and brain tumors were taken for this study and contoured on Eclipse treatment planning system (TPS after importing images from CT. These contoured images were then exported using radiotherapy DICOM transfer facility to XIO CMS planning system and compared the contoured volumes with Eclipse TPS structured volumes. Results: Our analysis showed that the differences in calculated volumes of the contours for the patients between the two planning systems can be large. Mixed results are shown for different organs with the absolute volume difference ranging from -0.25 cc to 319.73 cc. These results clearly shown that the two TPS interprets the contours differently when calculating the volume, and there is a closer match with the theoretical calculated volumes with XIO CMS calculated volumes. Conclusion: Observed discrepancies were consistent between the two planning systems. This impact of contouring variability could play a role on plan quality metrics which is used as criteria for clinical trial protocol compliance.

  13. Menstrual variation of breast volume and T{sub 2} relaxation times in cyclical mastalgia

    Energy Technology Data Exchange (ETDEWEB)

    Hussain, Zainab [Department of Medical Imaging, University of Liverpool, Johnstone Building, Brownlow Hill, P.O. Box 147, Liverpool, Merseyside L69 3GB (United Kingdom); Magnetic Resonance and Image Analysis Research Centre, University of Liverpool, Johnstone Building, Brownlow Hill, P.O. Box 147, Liverpool, Merseyside L69 3GB (United Kingdom)], E-mail: zay@liverpool.ac.uk; Brooks, Jonathan [Magnetic Resonance and Image Analysis Research Centre, University of Liverpool, Johnstone Building, Brownlow Hill, P.O. Box 147, Liverpool, Merseyside L69 3GB (United Kingdom); Department of Human Anatomy and Genetics, University of Oxford, Oxford (United Kingdom); Percy, Dave [Centre for Operational Research and Applied Statistics, University of Salford, Salford, Greater Manchester M5 4WT (United Kingdom)

    2008-02-15

    Purpose: Hormonal activity causes breast volume to change during the menstrual cycle. One possible cause of this volume change is thought to be due to water retention or oedema within the tissues. We used magnetic resonance imaging (MRI) to study the variation in breast volume and {sup 1}H Magnetic Resonance Spectroscopy (MRS) to measure T{sub 2} relaxation times which are known to increase with increasing tissue water content. We hypothesised that an increase in breast volume will elevate T{sub 2} relaxation due to the presence of an increased water content within the breast. T{sub 2} Relaxation time and volume were studied in fifteen control subjects and in a cohort of eight patients with cyclical mastalgia in order to determine whether changes in breast volume and T{sub 2} relaxation times differed in controls and patients during menses, ovulation and premenses. Method: Breast volume was determined by the Cavalieri method in combination with point counting techniques on MR images and T{sub 2} relaxation times of the water and fat in a voxel of breast tissue were obtained using {sup 1}H Magnetic Resonance Spectroscopy (MRS). Results: Statistical analysis (ANOVA) demonstrated highly significant differences in breast volume between the three stages of the cycle (p < 0.0005) with breast volume being greatest premenstrually. Patients did not exhibit an increase in volume premenstrually, significantly above controls. T{sub 2} of fat or water did not depend on stage of cycle. T-tests demonstrated no significant differences in T{sub 2} of water or fat between patient and control groups. The average T{sub 2} relaxation time of water was lowest in the patient and control groups during ovulation and highest in the patient group during premenses. Conclusion: We have performed the first combined volumetric and spectroscopic study of women with cyclical mastalgia and demonstrated that the global changes in volumes and T{sub 2} were not significantly different from normal

  14. Low variation and high reproducibility in plaque volume with intravascular ultrasound

    DEFF Research Database (Denmark)

    Jensen, Lisette Okkels; Thayssen, Per; Pedersen, Knud Erik;

    2004-01-01

    by electrocardiographic-gated three-dimensional (3D) IVUS in 20 male patients with ischaemic heart disease (IHD). RESULTS: The study lesions were angiographically insignificant, with a length of the analysed segment on 11.4+/-5.9 mm. At baseline the mean minimal lumen diameter was 2.41+/-0.59 mm, minimal lumen area 4.......82+/-2.38 mm2, and maximal plaque burden 65.61+/-9.57%. Mean reference diameter was 3.1+/-0.6 mm. No significant changes were observed in volumes of total vessel, lumen or plaque. The coefficient of variation (CV) for two volume measurements at baseline was: vessel 0.8%, plaque 1.3%, and lumen 1.......4%. For measurements recorded at baseline and after 12.6+/-1.5 weeks, CV was respectively 3.5%, 3.3% and 6.6%. Reproducibility and interobserver and intraobserver variation showed very high correlations. A linear correlation was present in percent changes over 12.6+/-1.5 weeks between vessel volume and lumen volume (r...

  15. A Comparative Study of Pituitary Volume Variations in MRI in Acute Onset of Psychiatric Conditions.

    Science.gov (United States)

    Soni, Brijesh Kumar; Joish, Upendra Kumar; Sahni, Hirdesh; George, Raju A; Sivasankar, Rajeev; Aggarwal, Rohit

    2017-02-01

    The growing belief that endocrine abnormalities may underlie many mental conditions has led to increased use of imaging and hormonal assays in patients attending to psychiatric OPDs. People who are in an acute phase of a psychiatric disorder show Hypothalamic Pituitary Adrenal (HPA) axis hyperactivity, but the precise underlying central mechanisms are unclear. To assess the pituitary gland volume variations in patients presenting with new onset acute psychiatric illness in comparison with age and gender matched controls by using MRI. The study included 50 patients, with symptoms of acute psychiatric illness presenting within one month of onset of illness and 50 age and gender matched healthy controls. Both patients and controls were made to undergo MRI of the Brain. A 0.9 mm slices of entire brain were obtained by 3 dimensional T1 weighted sequence. Pituitary gland was traced in all sagittal slices. Anterior pituitary and posterior pituitary bright spot were measured separately in each slice. Volume of the pituitary (in cubic centimetre- cm(3)) was calculated by summing areas. Significance of variations in pituitary gland volumes was compared between the cases and controls using Analysis of Covariance (ANOVA). There were significantly larger pituitary gland volumes in the cases than the controls, irrespective of psychiatric diagnosis (ANOVA, f=15.56; p=0.0002). Pituitary volumes in cases were 15.36% (0.73 cm(3)) higher than in controls. There is a strong likelihood of HPA axis overactivity during initial phase of all mental disorders along with increased pituitary gland volumes. Further studies including hormonal assays and correlation with imaging are likely to provide further insight into neuroanatomical and pathological basis of psychiatric disorders.

  16. Viscosity of water-in-oil emulsions. Variation with temperature and water volume fraction

    Energy Technology Data Exchange (ETDEWEB)

    Farah, Marco A.; Caldas, Jorge Navaes [Petroleo Brasileiro S.A., Rua General Canabarro, 500, Maracana, Rio, CEP 2057-900 (Brazil); Oliveira, Roberto C. [Petroleo Brasileiro S.A., Cenpes, Cidade Universitaria (Brazil); Rajagopal, Krishnaswamy [LATCA-Laboratorio de Termodinamica e Cinetica Aplicada-Escola de Quimica, Departamento de Engenharia Quimica, Universidade Federal do Rio de Janeiro, UFRJ, Cidade Universitaria, C.P. 68452, CEP 21949-900, Rio de Janeiro (Brazil)

    2005-09-15

    Water-in-oil emulsions are important in the petroleum industry in production operations, where the water content of the emulsion can be as high as 60% in volume, also in petroleum refining operations where generally the water content is low. The effective viscosity of water-in-oil emulsions depends mainly on the volume fraction of dispersed phase and temperature, along with several minor effects, such as shear rate, average droplet size, droplet size distribution, viscosity and density of oil. Using six different crude oils, the effective viscosities of several synthetic water-in-oil emulsions are measured at atmospheric pressure using a dynamic viscosimeter for different shear rates, temperatures and volume fractions of the dispersed phase. The ASTM equation, method D-341, for describing viscosity as a function of temperature is extended to include the variation of dispersed phase volume fraction. The proposed equation gives good correlation between the measured viscosities of water-in-oil emulsions as a function of temperature and the volume fraction of water.

  17. Variation in mouse basolateral amygdala volume is associated with differences in stress reactivity and fear learning.

    Science.gov (United States)

    Yang, Rebecca J; Mozhui, Khyobeni; Karlsson, Rose-Marie; Cameron, Heather A; Williams, Robert W; Holmes, Andrew

    2008-10-01

    A wealth of research identifies the amygdala as a key brain region mediating negative affect, and implicates amygdala dysfunction in the pathophysiology of anxiety disorders. Although there is a strong genetic component to anxiety disorders such as posttraumatic stress disorder (PTSD) there remains debate about whether abnormalities in amygdala function predispose to these disorders. In the present study, groups of C57BL/6 x DBA/2 (B x D) recombinant inbred strains of mice were selected for differences in volume of the basolateral amygdala complex (BLA). Strains with relatively small, medium, or large BLA volumes were compared for Pavlovian fear learning and memory, anxiety-related behaviors, depression-related behavior, and glucocorticoid responses to stress. Strains with relatively small BLA exhibited stronger conditioned fear responses to both auditory tone and contextual stimuli, as compared to groups with larger BLA. The small BLA group also showed significantly greater corticosterone responses to stress than the larger BLA groups. BLA volume did not predict clear differences in measures of anxiety-like behavior or depression-related behavior, other than greater locomotor inhibition to novelty in strains with smaller BLA. Neither striatal, hippocampal nor cerebellar volumes correlated significantly with any behavioral measure. The present data demonstrate a phenotype of enhanced fear conditioning and exaggerated glucocorticoid responses to stress associated with small BLA volume. This profile is reminiscent of the increased fear processing and stress reactivity that is associated with amygdala excitability and reduced amygdala volume in humans carrying loss of function polymorphisms in the serotonin transporter and monoamine oxidase A genes. Our study provides a unique example of how natural variation in amygdala volume associates with specific fear- and stress-related phenotypes in rodents, and further supports the role of amygdala dysfunction in anxiety

  18. Association of Variation in Contrast Volume With Acute Kidney Injury in Patients Undergoing Percutaneous Coronary Intervention.

    Science.gov (United States)

    Amin, Amit P; Bach, Richard G; Caruso, Mary L; Kennedy, Kevin F; Spertus, John A

    2017-09-01

    Acute kidney injury (AKI) after percutaneous coronary intervention (PCI) is common, morbid, and costly; increases patients' mortality risk; and can be mitigated by limiting contrast use. To examine the national variation in AKI incidence and contrast use among US physicians and the variation's association with patients' risk of developing AKI after PCI. This cross-sectional study used the American College of Cardiology National Cardiovascular Data Registry (NCDR) CathPCI Registry to identify in-hospital care for PCI in the United States. Participants included 1 349 612 patients who underwent PCI performed by 5973 physicians in 1338 hospitals between June 1, 2009, and June 30, 2012. Data analysis was performed from July 1, 2014, to August 31, 2016. The primary outcome was AKI, defined according to the Acute Kidney Injury Network criteria as an absolute increase of 0.3 mg/dL or more or a relative increase of 50% or more from preprocedural to peak creatinine. A secondary outcome was the mean contrast volume as reported in the NCDR CathPCI Registry. Physicians who performed more than 50 PCIs per year were the main exposure variable of interest. Hierarchical regression with adjustment for patients' AKI risk was used to identify the variation in AKI rates, the variation in contrast use, and the association of contrast volume with patients' predicted AKI risk. Of the 1 349 612 patients who underwent PCI, the mean (SD) age was 64.9 (12.2) years, 908 318 (67.3%) were men, and 441 294 (32.7%) were women. Acute kidney injury occurred in 94 584 patients (7%). A large variation in AKI rates was observed among individual physicians ranging from 0% to 30% (unadjusted), with a mean adjusted 43% excess likelihood of AKI (median odds ratio, 1.43; 95% CI, 1.41-1.44) for statistically identical patients presenting to 2 random physicians. A large variation in physicians' mean contrast volume, ranging from 79 mL to 487 mL with an intraclass correlation coefficient of 0

  19. Natural allelic variation of the IL-21 receptor modulates ischemic stroke infarct volume.

    Science.gov (United States)

    Lee, Han Kyu; Keum, Sehoon; Sheng, Huaxin; Warner, David S; Lo, Donald C; Marchuk, Douglas A

    2016-08-01

    Risk for ischemic stroke has a strong genetic basis, but heritable factors also contribute to the extent of damage after a stroke has occurred. We previously identified a locus on distal mouse chromosome 7 that contributes over 50% of the variation in postischemic cerebral infarct volume observed between inbred strains. Here, we used ancestral haplotype analysis to fine-map this locus to 12 candidate genes. The gene encoding the IL-21 receptor (Il21r) showed a marked difference in strain-specific transcription levels and coding variants in neonatal and adult cortical tissue. Collateral vessel connections were moderately reduced in Il21r-deficient mice, and cerebral infarct volume increased 2.3-fold, suggesting that Il21r modulates both collateral vessel anatomy and innate neuroprotection. In brain slice explants, oxygen deprivation (OD) activated apoptotic pathways and increased neuronal cell death in IL-21 receptor-deficient (IL-21R-deficient) mice compared with control animals. We determined that the neuroprotective effects of IL-21R arose from signaling through JAK/STAT pathways and upregulation of caspase 3. Thus, natural genetic variation in murine Il21r influences neuronal cell viability after ischemia by modulating receptor function and downstream signal transduction. The identification of neuroprotective genes based on naturally occurring allelic variations has the potential to inform the development of drug targets for ischemic stroke treatment.

  20. Temporal variations of serial correlations of trading volume in the US stock market

    Science.gov (United States)

    Alvarez-Ramírez, José; Rodríguez, Eduardo

    2012-08-01

    Serial correlations in the trading volume of the US stock market are investigated in this paper. The use of the detrended fluctuation analysis implemented within a rolling window indicated that, for the period 1929-2011, the strength of correlations exhibits important temporal variations with a trend shift by the 1990s, and 4-year and 21-year cycles. These empirical findings are compared to those obtained for mature international stock markets (FTSE-100 and Nikkei) and discussed in terms of potential economic and financial implications.

  1. Determination of protein and solvent volumes in protein crystals from contrast variation data

    Energy Technology Data Exchange (ETDEWEB)

    Badger, J. [Brandeis Univ., Waltham, MA (United States)

    1994-12-31

    By varying the relative values of protein and solvent scattering densities in a crystal, it is possible to obtain information on the shape and dimensions of protein molecular envelopes. Neutron diffraction methods are ideally suited to these contrast variation experiments because H/D exchange leads to large differential changes in the protein and solvent scattering densities and is structurally non-perturbing. Low resolution structure factors have been measured from cubic insulin crystals with differing H/D contents. Structure factors calculated from a simple binary density model, in which uniform scattering densities represent the protein and solvent volumes in the crystals, were compared with these data. The contrast variation differences in the sets of measured structure factors were found to be accurately fitted by this simple model. Trial applications to two problems in crystal structure determination illustrate how this fact may be exploited. (1) A translation function that employs contrast variation data gave a sharp minimum within 1-9{Angstrom} of the correctly positioned insulin molecule and is relatively insensitive to errors in the atomic model. (2) An ab initio phasing method for the contrast variation data, based on analyzing histograms of the density distributions in trial maps, was found to recover the correct molecular envelope.

  2. 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.

  3. The effects of renal variation upon measurements of perfusion and leakage volume in breast tumours

    Science.gov (United States)

    Ahearn, T. S.; Staff, R. T.; Redpath, T. W.; Semple, S. I. K.

    2004-05-01

    Dynamic contrast enhanced MRI (DCE-MRI) and pharmacokinetic models have been used to measure tumour permeability (Ktrans) and leakage volume (ve) in numerous studies. The construction of pharmacokinetic models describing such tissue properties relies on defining the blood plasma concentration of contrast agent with respect to time (Cp(t)). When direct measurement is not possible a bi-exponential decay has been applied using data from healthy volunteers. This work investigates, by simulation, the magnitude of errors resulting from this definition with respect to normal variation in renal function and for cases with renal impairment. Errors up to 23% in ve and 28% in Ktrans were found for the normal simulations, and 67% in ve and 61% in Ktrans for the impaired simulations. If this bi-exponential curve is used as an input function to the generalized kinetic model and used in oncology, estimates of tissue permeability and leakage volume will possess large errors due to variation in Cp(t) curves between subjects.

  4. Mechanisms controlling warm water volume interannual variations in the equatorial Pacific: diabatic versus adiabatic processes

    Energy Technology Data Exchange (ETDEWEB)

    Lengaigne, M. [CNRS, UPMC, IRD, Laboratoire d' Oceanographie Experimentation et Approches Numeriques, Paris (France); Paris Cedex 05 (France); Hausmann, U. [Imperial College, Department of Physics, London (United Kingdom); Madec, G. [CNRS, UPMC, IRD, Laboratoire d' Oceanographie Experimentation et Approches Numeriques, Paris (France); National Oceanographic Centre, Southampton (United Kingdom); Menkes, C.; Vialard, J. [CNRS, UPMC, IRD, Laboratoire d' Oceanographie Experimentation et Approches Numeriques, Paris (France); Molines, J.M. [CNRS, UJF, INP, Laboratoire Ecoulements Geophysiques et Industriels, Grenoble (France)

    2012-03-15

    Variations of the volume of warm water above the thermocline in the equatorial Pacific are a good predictor of ENSO (El Nino/Southern Oscillation) and are thought to be critical for its preconditioning and development. In this study, the Warm Water Volume (WWV) interannual variability is analysed using forced general circulation model experiments and an original method for diagnosing processes responsible for WWV variations. The meridional recharge/discharge to higher latitudes drives 60% of the ENSO-related equatorial WWV variations, while diabatic processes in the eastern equatorial Pacific account for the remaining 40%. Interior meridional transport is partially compensated by western boundary transports, especially in the southern hemisphere. Diabatic equatorial WWV formation (depletions) during La Nina (El Nino) are explained by enhanced (reduced) diathermal transport through enhanced (reduced) vertical mixing and penetrating solar forcing at the 20 C isotherm depth. The respective contribution of diabatic and adiabatic processes during build-ups/depletions strongly varies from event-to-event. The WWV build-up during neutral ENSO phases (e.g. 1980-1982) is almost entirely controlled by meridional recharge, providing a text-book example for the recharge/discharge oscillator's theory. On the other hand, diabatic processes are particularly active during the strongest La Nina events (1984, 1988, 1999), contributing to more than 70% of the WWV build-up, with heating by penetrative solar fluxes explaining as much as 30% of the total build-up due to a very shallow thermocline in the eastern Pacific. This study does not invalidate the recharge/discharge oscillator theory but rather emphasizes the importance of equatorial diabatic processes and western boundary transports in controlling WWV changes. (orig.)

  5. Radial variations of the volume and surface star formation laws in the Galaxy

    Science.gov (United States)

    Sofue, Yoshiaki

    2017-08-01

    Variation of the volume and surface Schmidt laws (star formation or SF law) with the galacto-centric distance R was investigated using 3D distributions of H II regions, H i, and molecular (H2) gases in the Milky Way. Both the power-law index and SF coefficient were found to vary with R. The index is flatter in the inner disc than in the outer Galaxy, and the coefficient is larger in the inner disc, decreasing steeply outwardly. There is also a mutual anti-correlation between the index and SF coefficient, and the SF law can be expressed by a single-parameter function of the SF coefficient. The variable SF law is discussed in relation to self-regulation of SF.

  6. Can a central blood volume deficit be detected by systolic pressure variation during spontaneous breathing?

    DEFF Research Database (Denmark)

    Dahl, Michael; Hayes, Chris; Steen Rasmussen, Bodil

    2016-01-01

    cardiac output (CO). This study tested that hypothesis in healthy volunteers exposed to central hypovolemia by head-up tilt. METHODS: Thirteen healthy volunteers were exposed to central hypovolemia by 45° head-up tilt while breathing through a facemask with 7.5 cmH2O inspiratory and/or expiratory......BACKGROUND: Whether during spontaneous breathing arterial pressure variations (APV) can detect a volume deficit is not established. We hypothesized that amplification of intra-thoracic pressure oscillations by breathing through resistors would enhance APV to allow identification of a reduced...... (from 21 (±15)% to 30 (±13)%). Yet during head-up tilt, a SPV ≥ 37 % predicted a decrease in CO ≥ 10 % with a sensitivity and specificity of 78 % and 100 %, respectively. CONCLUSION: In spontaneously breathing healthy volunteers combined inspiratory and expiratory resistors enhance SPV during head...

  7. Variation of Red Blood Cell Distribution Width and Mean Platelet Volume after Moderate Endurance Exercise

    Directory of Open Access Journals (Sweden)

    Giuseppe Lippi

    2014-01-01

    Full Text Available Although physical exercise strongly influences several laboratory parameters, data about the hematological changes after medium distance running are scarce. We studied 31 middle-trained athletes (mean training regimen 217±32 min/week who performed a 21.1 km, half-marathon run. Blood samples were collected before the run, at the end, and 3 and 20 hours thereafter. The complete blood count was performed on Advia 2120 and included red blood cell (RBC, reticulocyte, and platelet counts; hemoglobin; mean corpuscular volume (MCV; mean corpuscular hemoglobin (MCH; reticulocyte haemoglobin content (Ret CHR; RBC distribution width (RDW, mean platelet volume (MPV. No significant variations were observed for MCH and Ret CHR. The RBC, reticulocyte, and hemoglobin values modestly decreased after the run. The MCV significantly increased at the end of running but returned to baseline 3 hours thereafter. The RDW constantly increased, reaching a peak 20 hours after the run. The platelet count and MPV both increased after the run and returned to baseline 3 hours thereafter. These results may have implications for definition of reference ranges and antidoping testing, and may also contribute to explaining the relationship between endurance exercise and mortality, since previous studies reported that RDW and MPV may be significantly associated with cardiovascular disease.

  8. Pulse pressure variation and prediction of fluid responsiveness in patients ventilated with low tidal volumes

    Directory of Open Access Journals (Sweden)

    Clarice Daniele Alves de Oliveira-Costa

    2012-07-01

    Full Text Available OBJECTIVE: To determine the utility of pulse pressure variation (ΔRESP PP in predicting fluid responsiveness in patients ventilated with low tidal volumes (V T and to investigate whether a lower ΔRESP PP cut-off value should be used when patients are ventilated with low tidal volumes. METHOD: This cross-sectional observational study included 37 critically ill patients with acute circulatory failure who required fluid challenge. The patients were sedated and mechanically ventilated with a V T of 6-7 ml/kg ideal body weight, which was monitored with a pulmonary artery catheter and an arterial line. The mechanical ventilation and hemodynamic parameters, including ΔRESP PP, were measured before and after fluid challenge with 1,000 ml crystalloids or 500 ml colloids. Fluid responsiveness was defined as an increase in the cardiac index of at least 15%. ClinicalTrial.gov: NCT01569308. RESULTS: A total of 17 patients were classified as responders. Analysis of the area under the ROC curve (AUC showed that the optimal cut-off point for ΔRESP PP to predict fluid responsiveness was 10% (AUC = 0.74. Adjustment of the ΔRESP PP to account for driving pressure did not improve the accuracy (AUC = 0.76. A ΔRESP PP>10% was a better predictor of fluid responsiveness than central venous pressure (AUC = 0.57 or pulmonary wedge pressure (AUC = 051. Of the 37 patients, 25 were in septic shock. The AUC for ΔRESP PP>10% to predict responsiveness in patients with septic shock was 0.484 (sensitivity, 78%; specificity, 93%. CONCLUSION: The parameter D RESP PP has limited value in predicting fluid responsiveness in patients who are ventilated with low tidal volumes, but a ΔRESP PP>10% is a significant improvement over static parameters. A ΔRESP PP > 10% may be particularly useful for identifying responders in patients with septic shock.

  9. Measurement of Throughput Variation Across A Large Format Volume-Phase Holographic Grating

    CERN Document Server

    Tamura, N; Sharples, R M; Robertson, D J; Allington-Smith, J R; Tamura, Naoyuki; Murray, Graham J.; Sharples, Ray M.; Robertson, David J.

    2005-01-01

    In this paper, we report measurements of diffraction efficiency and angular dispersion for a large format (~ 25 cm diameter) Volume-Phase Holographic (VPH) grating optimized for near-infrared wavelengths (0.9 -- 1.8 micron). The aim of this experiment is to see whether optical characteristics vary significantly across the grating. We sampled three positions in the grating aperture with a separation of 5 cm between each. A 2 cm diameter beam is used to illuminate the grating. At each position, throughput and diffraction angle were measured at several wavelengths. It is found that whilst the relationship between diffraction angle and wavelength is nearly the same at the three positions, the throughputs vary by up to ~ 10\\% from position to position. We explore the origin of the throughput variation by comparing the data with predictions from coupled-wave analysis. We find that it can be explained by a combination of small variations over the grating aperture in gelatin depth and/or refractive index modulation a...

  10. Increased cellular immune responses and CD4+ T-cell proliferation correlate with reduced plasma viral load in SIV challenged recombinant simian varicella virus - simian immunodeficiency virus (rSVV-SIV vaccinated rhesus macaques

    Directory of Open Access Journals (Sweden)

    Pahar Bapi

    2012-08-01

    Full Text Available Abstract Background An effective AIDS vaccine remains one of the highest priorities in HIV-research. Our recent study showed that vaccination of rhesus macaques with recombinant simian varicella virus (rSVV vector – simian immunodeficiency virus (SIV envelope and gag genes, induced neutralizing antibodies and cellular immune responses to SIV and also significantly reduced plasma viral loads following intravenous pathogenic challenge with SIVMAC251/CX1. Findings The purpose of this study was to define cellular immunological correlates of protection in rSVV-SIV vaccinated and SIV challenged animals. Immunofluorescent staining and multifunctional assessment of SIV-specific T-cell responses were evaluated in both Experimental and Control vaccinated animal groups. Significant increases in the proliferating CD4+ T-cell population and polyfunctional T-cell responses were observed in all Experimental-vaccinated animals compared with the Control-vaccinated animals. Conclusions Increased CD4+ T-cell proliferation was significantly and inversely correlated with plasma viral load. Increased SIV-specific polyfunctional cytokine responses and increased proliferation of CD4+ T-cell may be crucial to control plasma viral loads in vaccinated and SIVMAC251/CX1 challenged macaques.

  11. 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.

  12. Adaptive evolution of interleukin-3 (IL3), a gene associated with brain volume variation in general human populations.

    Science.gov (United States)

    Li, Ming; Huang, Liang; Li, Kaiqin; Huo, Yongxia; Chen, Chunhui; Wang, Jinkai; Liu, Jiewei; Luo, Zhenwu; Chen, Chuansheng; Dong, Qi; Yao, Yong-gang; Su, Bing; Luo, Xiong-jian

    2016-04-01

    Greatly expanded brain volume is one of the most characteristic traits that distinguish humans from other primates. Recent studies have revealed genes responsible for the dramatically enlarged human brain size (i.e., the microcephaly genes), and it has been well documented that many microcephaly genes have undergone accelerated evolution along the human lineage. In addition to being far larger than other primates, human brain volume is also highly variable in general populations. However, the genetic basis underlying human brain volume variation remains elusive and it is not known whether genes regulating human brain volume variation also have experienced positive selection. We have previously shown that genetic variants (near the IL3 gene) on 5q33 were significantly associated with brain volume in Chinese population. Here, we provide further evidence that support the significant association of genetic variants on 5q33 with brain volume. Bioinformatic analyses suggested that rs31480 is likely to be the causal variant among the studied SNPs. Molecular evolutionary analyses suggested that IL3 might have undergone positive selection in primates and humans. Neutrality tests further revealed signatures of positive selection of IL3 in Han Chinese and Europeans. Finally, extended haplotype homozygosity (EHH) and relative EHH analyses showed that the C allele of SNP rs31480 might have experienced recent positive selection in Han Chinese. Our results suggest that IL3 is an important genetic regulator for human brain volume variation and implied that IL3 might have experienced weak or modest positive selection in the evolutionary history of humans, which may be due to its contribution to human brain volume.

  13. Education as Experimentation: A Planned Variation Model. Volume IIIA: Findings: Cohort II; Interim Findings: Cohort III. Volume IIIB: Appendices.

    Science.gov (United States)

    Stebbins, Linda B.; And Others

    This segment of the national evaluation study of the Follow Through Planned Variation Model reviews the background of the study, describes 13 of the Follow Through models involved, and presents an analysis of the effects of these models on students. The analysis is based on data from 4 years of Follow Through participation by Cohort II children…

  14. Detecting variations of blood volume shift due to heart beat from respiratory inductive plethysmography measurements in man.

    Science.gov (United States)

    Fontecave-Jallon, J; Videlier, B; Baconnier, P; Tanguy, S; Calabrese, P; Guméry, P-Y

    2013-09-01

    The simultaneous study of the cardiac and respiratory activities and their interactions is of great physiological and clinical interest. For this purpose, we want to investigate if respiratory inductive plethysmography (RIP) can be used for cardiac functional exploration. We propose a system, based on RIP technology and time-scale approaches of signal processing, for the extraction of cardiac information. This study focuses on the monitoring of blood volume shift due to heart beat, noted ▵Vtr_c and investigates RIP for the detection of ▵Vtr_c variations by comparison to stroke volume (SV) variations estimated by impedance cardiography (IMP). We proposed a specific respiratory protocol assumed to induce significant variations of the SV. Fifteen healthy volunteers in the seated and supine positions were asked to alternate rest respiration and maneuvers, consisting in blowing into a manometer. A multi-step treatment including a variant of empirical mode decomposition was applied on RIP signals to extract cardiac volume signals and estimate beat-to-beat ▵Vtr_c. These were averaged in quasi-stationary states at rest and during the respiratory maneuvers, and analysed in view of SV estimations from IMP signals simultaneously acquired. Correlation and statistical tests over the data show that RIP can be used to detect variations of the cardiac blood shift in healthy young subjects.

  15. Experimental investigation of temperature and volume fraction variations on the effective thermal conductivity of nanoparticle suspensions (nanofluids)

    Science.gov (United States)

    Li, Calvin H.; Peterson, G. P.

    2006-04-01

    An experimental investigation was conducted to examine the effects of variations in the temperature and volume fraction on the steady-state effective thermal conductivity of two different nanoparticle suspensions. Copper and aluminum oxide, CuO and Al2O3, nanoparticles with area weighted diameters of 29 and 36 nm, respectively, were blended with distilled water at 2%, 4%, 6%, and 10% volume fractions and the resulting suspensions were evaluated at temperatures ranging from 27.5 to 34.7 °C. The results indicate that the nanoparticle material, diameter, volume fraction, and bulk temperature, all have a significant impact on the effective thermal conductivity of these suspensions. The 6% volume fraction of CuO nanoparticle/distilled water suspension resulted in an increase in the effective thermal conductivity of 1.52 times that of pure distilled water and the 10% Al2O3 nanoparticle/distilled water suspension increased the effective thermal conductivity by a factor of 1.3, at a temperature of 34 °C. A two-factor linear regression analysis based on the temperature and volume fraction was applied and indicated that the experimental results are in stark contrast to the trends predicted by the traditional theoretical models with respect to both temperature and volume fraction. The available models are reviewed and the possible reasons for the unusually high effective thermal conductivity of nanofluids are analyzed and discussed.

  16. Target volume delineation variation in radiotherapy for early stage rectal cancer in the Netherlands

    NARCIS (Netherlands)

    Nijkamp, Jasper; de Haas-Kock, Danielle F. M.; Beukema, Jannet C.; Neelis, Karen J.; Woutersen, Dankert; Ceha, Heleen; Rozema, Tom; Slot, Annerie; Vos-Westerman, Hanneke; Intven, Martijn; Spruit, Patty H.; van der Linden, Yvette; Geijsen, Debby; Verschueren, Karijn; van Herk, Marcel B.; Marijnen, Corrie A. M.

    2012-01-01

    Purpose: The aim of this study was to measure and improve the quality of target volume delineation by means of national consensus on target volume definition in early-stage rectal cancer. Methods and materials: The CTV's for eight patients were delineated by 11 radiation oncologists in 10 institutes

  17. Variation.

    Science.gov (United States)

    Hamilton City Board of Education (Ontario).

    Suggestions for studying the topic of variation of individuals and objects (balls) to help develop elementary school students' measurement, comparison, classification, evaluation, and data collection and recording skills are made. General suggestions of variables that can be investigated are made for the study of human variation. Twelve specific…

  18. Despite variation in volume, Veterans Affairs hospitals show consistent outcomes among patients with non-postoperative mechanical ventilation.

    Science.gov (United States)

    Cooke, Colin R; Kennedy, Edward H; Wiitala, Wyndy L; Almenoff, Peter L; Sales, Anne E; Iwashyna, Theodore J

    2012-09-01

    To assess the relationship between volume of nonoperative mechanically ventilated patients receiving care in a specific Veterans Health Administration hospital and their mortality. Retrospective cohort study. One-hundred nineteen Veterans Health Administration medical centers. We identified 5,131 hospitalizations involving mechanically ventilated patients in an intensive care unit during 2009, who did not receive surgery. None. We extracted demographic and clinical data from the VA Inpatient Evaluation Center. For each hospital, we defined volume as the total number of nonsurgical admissions receiving mechanical ventilation in an intensive care unit during 2009. We examined the hospital contribution to 30-day mortality using multilevel logistic regression models with a random intercept for each hospital. We quantified the extent of interhospital variation in 30-day mortality using the intraclass correlation coefficient and median odds ratio. We used generalized estimating equations to examine the relationship between volume and 30-day mortality and risk-adjusted all models using a patient-level prognostic score derived from clinical data representing the risk of death conditional on treatment at a high-volume hospital. Mean age for the sample was 65 (SD 11) yrs, 97% were men, and 60% were white. The median VA hospital cared for 40 (interquartile range 19-62) mechanically ventilated patients in 2009. Crude 30-day mortality for these patients was 36.9%. After reliability and risk adjustment to the median patient, adjusted hospital-level mortality varied from 33.5% to 40.6%. The intraclass correlation coefficient for the hospital-level variation was 0.6% (95% confidence interval 0.1, 3.4%), with a median odds ratio of 1.15 (95% confidence interval 1.06, 1.38). The relationship between hospital volume of mechanically ventilated and 30-day mortality was not statistically significant: each 50-patient increase in volume was associated with a nonsignificant 2% decrease in

  19. Lake volume and groundwater storage variations in Tibetan Plateau's endorheic basin

    Science.gov (United States)

    Zhang, Guoqing; Yao, Tandong; Shum, C. K.; Yi, Shuang; Yang, Kun; Xie, Hongjie; Feng, Wei; Bolch, Tobias; Wang, Lei; Behrangi, Ali; Zhang, Hongbo; Wang, Weicai; Xiang, Yang; Yu, Jinyuan

    2017-06-01

    The Tibetan Plateau (TP), the highest and largest plateau in the world, with complex and competing cryospheric-hydrologic-geodynamic processes, is particularly sensitive to anthropogenic warming. The quantitative water mass budget in the TP is poorly known. Here we examine annual changes in lake area, level, and volume during 1970s-2015. We find that a complex pattern of lake volume changes during 1970s-2015: a slight decrease of -2.78 Gt yr-1 during 1970s-1995, followed by a rapid increase of 12.53 Gt yr-1 during 1996-2010, and then a recent deceleration (1.46 Gt yr-1) during 2011-2015. We then estimated the recent water mass budget for the Inner TP, 2003-2009, including changes in terrestrial water storage, lake volume, glacier mass, snow water equivalent (SWE), soil moisture, and permafrost. The dominant components of water mass budget, namely, changes in lake volume (7.72 ± 0.63 Gt yr-1) and groundwater storage (5.01 ± 1.59 Gt yr-1), increased at similar rates. We find that increased net precipitation contributes the majority of water supply (74%) for the lake volume increase, followed by glacier mass loss (13%), and ground ice melt due to permafrost degradation (12%). Other term such as SWE (1%) makes a relatively small contribution. These results suggest that the hydrologic cycle in the TP has intensified remarkably during recent decades.

  20. Variation in the measurement of cranial volume and surface area using 3D laser scanning technology.

    Science.gov (United States)

    Sholts, Sabrina B; Wärmländer, Sebastian K T S; Flores, Louise M; Miller, Kevin W P; Walker, Phillip L

    2010-07-01

    Three-dimensional (3D) laser scanner models of human crania can be used for forensic facial reconstruction, and for obtaining craniometric data useful for estimating age, sex, and population affinity of unidentified human remains. However, the use of computer-generated measurements in a casework setting requires the measurement precision to be known. Here, we assess the repeatability and precision of cranial volume and surface area measurements using 3D laser scanner models created by different operators using different protocols for collecting and processing data. We report intraobserver measurement errors of 0.2% and interobserver errors of 2% of the total area and volume values, suggesting that observer-related errors do not pose major obstacles for sharing, combining, or comparing such measurements. Nevertheless, as no standardized procedure exists for area or volume measurements from 3D models, it is imperative to report the scanning and postscanning protocols employed when such measurements are conducted in a forensic setting.

  1. Validation of a New Method for Stroke Volume Variation Assessment: a Comparaison with the PiCCO Technique

    CERN Document Server

    Laleg-Kirati, Taous-Meriem; Papelier, Yves; Cottin, François; Van De Louw, Andry

    2009-01-01

    This paper proposes a novel, simple and minimally invasive method for stroke volume variation assessment using arterial blood pressure measurements. The arterial blood pressure signal is reconstructed using a semi-classical signal analysis method allowing the computation of a parameter, called the first systolic invariant INVS1. We show that INVS1 is linearly related to stroke volume. To validate this approach, a statistical comparaison between INVS1 and stroke volume measured with the PiCCO technique was performed during a 15-mn recording in 21 mechanically ventilated patients in intensive care. In 94% of the whole recordings, a strong correlation was estimated by cross-correlation analysis (mean coefficient=0.9) and linear regression (mean coefficient=0.89). Once the linear relation had been verified, a Bland-Altman test showed the very good agreement between the two approaches and their interchangeability. For the remaining 6%, INVS1 and the PiCCO stroke volume were not correlated at all, and this discrepa...

  2. VARIATION AND SIGNIFICANCE OF C-MYC PROTEIN IN RAT CARDIAC VOLUME-OVERLOAD HYP ERTROPHY

    Institute of Scientific and Technical Information of China (English)

    刘华胜; 马爱群; 王一理; 刘勇; 李恒力; 田红燕

    2002-01-01

    Objective To investigate the change of c-myc protein, which was chosen as the response indicator to volume-overload. Methods The time and spatial course of c-myc protein expressi on on the model of rat cardiac volume-overload hyper trophy was examined by immunohistochemical study. Results The immunohistochemica l study indicated the expression of c-myc protein was increased obviously at 4 -6 hours (62.73%) than that of control (45.41%, P<0.01) after the volume-o verload, then decreased gradually along with development of volume-overload hyp ertrophy and was decreased extremely at 5 months(r=-0.514,P<0.01).Conclusion There are disorders in the signal transduction pathways governing the hypertrophic respon se of cardiomyocytes in hypertrophic myocardium. C-myc gene and the product of it may be only the promoter gene of myocardial hypertrophy. Once switching on, c-myc gene and the product of it do not act anymore;While it may be that c-my c gene and the product of it increased following with myocardial hypertrophy, an d have not direct relation to the occurrence and development of myocardial hyper trophy.

  3. VARIATION OF LUNG DEPOSITION OF MICRON SIZE PARTICLES WITH LUNG VOLUME AND BREATHING PATTERN

    Science.gov (United States)

    Lung volume and breathing pattern are the source of inter-and intra-subject variability of lung deposition of inhaled particles. Controlling these factors may help optimize delivery of aerosol medicine to the target site within the lung. In the present study we measured total lu...

  4. Variation in Nectar Volume and Sugar Concentration of Allium ursinum L. ssp. ucrainicum in Three Habitats

    Directory of Open Access Journals (Sweden)

    Ágnes Farkas

    2012-01-01

    Full Text Available Floral nectar volume and concentration of ramson (Allium ursinum L. ssp. ucrainicum were investigated in three different habitats, including two types of sessile oak-hornbeam association on brown forest soil with clay illuviation and a silver lime-flowering ash rock forest association on rendzina. Daily nectar production ranged from 0.1 to 3.8 μL per flower with sugar concentrations of 25 to 50%. Mean nectar volumes and concentrations showed significant differences between freely exposed flowers and covered flowers, which had been isolated from flower visitors 24 h prior to nectar studies. Both the amount and quality of nectar were affected by microclimatic conditions and soil properties and varied between populations at different habitats. In the silver lime-flowering ash rock-forest association mean nectar volumes and concentrations were lower than in a typical sessile oak-hornbeam association on three occasions, the difference being significant in two cases. During full bloom, the date of sampling did not have a profound effect on either nectar volume or concentration.

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

    Directory of Open Access Journals (Sweden)

    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.

  6. Variation in neoadjuvant chemotherapy utilization for epithelial ovarian cancer at high volume hospitals in the United States and associated survival.

    Science.gov (United States)

    Barber, Emma L; Dusetzina, Stacie B; Stitzenberg, Karyn B; Rossi, Emma C; Gehrig, Paola A; Boggess, John F; Garrett, Joanne M

    2017-06-01

    To estimate variation in the use of neoadjuvant chemotherapy by high volume hospitals and to determine the association between hospital utilization of neoadjuvant chemotherapy and survival. We identified incident cases of stage IIIC or IV epithelial ovarian cancer in the National Cancer Database from 2006 to 2012. Inclusion criteria were treatment at a high volume hospital (>20 cases/year) and treatment with both chemotherapy and surgery. A logistic regression model was used to predict receipt of neoadjuvant chemotherapy based on case-mix predictors (age, comorbidities, stage etc). Hospitals were categorized by the observed-to-expected ratio for neoadjuvant chemotherapy use as low, average, or high utilization hospitals. Survival analysis was performed. We identified 11,574 patients treated at 55 high volume hospitals. Neoadjuvant chemotherapy was used for 21.6% (n=2494) of patients and use varied widely by hospital, from 5%-55%. High utilization hospitals (n=1910, 10 hospitals) had a median neoadjuvant chemotherapy rate of 39% (range 23-55%), while low utilization hospitals (n=2671, 14 hospitals) had a median rate of 10% (range 5-17%). For all ovarian cancer patients adjusting for clinical and socio-demographic factors, treatment at a hospital with average or high neoadjuvant chemotherapy utilization was associated with a decreased rate of death compared to treatment at a low utilization hospital (HR 0.90 95% CI 0.83-0.97 and HR 0.85 95% CI 0.75-0.95). Wide variation exists in the utilization of neoadjuvant chemotherapy to treat stage IIIC and IV epithelial ovarian cancer even among high volume hospitals. Patients treated at hospitals with low rates of neoadjuvant chemotherapy utilization experience decreased survival. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. A comparative study of set up variations and bowel volumes in supine versus prone positions of patients treated with external beam radiation for carcinoma rectum

    Directory of Open Access Journals (Sweden)

    K R Rajeev

    2014-01-01

    Conclusion: The prone position using BB device was more effective in reducing irradiated SB volume in rectal cancer patients. There were no significant variations in the daily set up for patients treated in both supine and prone positions.

  8. Correlation between radius and respiration variation of inferior vena cava and hemodynamicmonitoring values of pulse-indicated continuous cardiac output(PiCCO)in septic shock pigs%脓毒症休克猪下腔静脉管径及呼吸变异指数与血流动力学的关系

    Institute of Scientific and Technical Information of China (English)

    王海峰; 刘笑雷; 陆海涛; 齐志伟; 闫圣涛; 顾承东; 张国强

    2012-01-01

    (IVCmax)and minimum radius(IVCmin)of IVC,and respiration variation index(RVI)was calculated at basic status,septic shock,1 hour and 6 hours after fluid resuscitation,respectively.Respiratory variation index of IVC were calculated as:RVI =(IVCmax-IVCmin)/ IVCmax × 100%.Hemodynamic monitoring values,including ITBV,GEDV,SVV and CI of PiCCO,were recorded at the same time.Radius and RVI of IVC and PiCCO values between before and after fluid resuscitation were compared by LSD-t test.Correlation between radius and RVI of IVC andhemodynamic monitoring values were calculated by Pearson correlation coefficient.Results Compared with the moment of septic shock,IVC IVCmin,GEDV,ITBV and CI at 1 after hour fluid resuscitation were larger(P < 0.01)and SVV and IVCrvi were smaller(P < 0.01).Compared with the moment of septic shock and 1 after hour fluid resuscitation,IVC[VCmin,GEDV,[TBV and CI at 6 hours after fluid resuscitation were larger(P < 0.01)and SVV and IVCrvi were smaller(P < 0.01).IVCmax correlated with SVV(P=0.024)and it failed to correlate with GEDV,ITBV and CI.IVCmin correlated with GEDV(P=0.003),ITBV(P =0.001),SVV(P =0.009)and CI(P =0.015),respectively.RVI was correlated withGEDV(P<0.01),ITBV(P<0.01),SVV(P=0.007)and CI(P<0.001),respectively.Conclusions Radius and RVI of IVC was correlated with hemodynamic monitoring values of PiCCO.It can serve as a parameter to rapidly estimate the blood volume.

  9. A study on variation types in celiac axis and superior mesenteric artery using 3D volume rendering of MDCT

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jeong Keun; Jang, Seong Joo [Dept. of Radiological physics Graduate School of Dongshin University, Naju (Korea, Republic of); Jang, Young Ill [Dept. of Radiological Technology of Kwangyang Health College, Kwangyang (Korea, Republic of)

    2013-06-15

    The aim of this study was to evaluate the variation which based on Celiac axis and SMA using by CT volume rendering images. 613 patients underwent abdominal CTA, there were 552 patients (99.05%, TypeⅠ, Ⅱ ) with normal anatomical form and 61 (9.95%, Type Ⅲ-Ⅻ) with variation. TypeⅠ was 339(55.31%), Type Ⅱ was 213 (34.74%), Type Ⅲ was 18 (2.93%), Type Ⅳ was 12 patients (1.95%), Type Ⅴ was 11 patient (1.79%), Type Ⅵ was 9 patients (1.46%), Type Ⅶ was 6 patients (0.97%), Type Ⅷ was 1 patient (0.16%), Type Ⅸ was 1 patient (0.16%), Type Ⅹ was 1 patient (0.16%), Type Ⅺ was 1 patient (0.16%), and Type Ⅻ was 1 patient (0.16%) into totally new types of variation. In conclusion, we could found 9 new types of variation by classifying based on celiac axis and superior mesenteric artery. These results were considered to be an important opportunity for a new vessel map.

  10. Education as Experimentation: A Planned Variation Model. Volume IV-A: An Evaluation of Follow Through.

    Science.gov (United States)

    Stebbins, Linda B.; And Others

    This segment of the national evaluation study of the Follow Through Planned Variation Model presents background information and discusses the evaluation of the progress of Cohort III entering-kindergarten children during 4 years of Follow Through participation. Also discussed, for the purpose of examining replicability of effects, is the progress…

  11. Probiotics for Rectal Volume Variation During Radiation Therapy for Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ki, Yongkan [Department of Radiation Oncology, Pusan National University School of Medicine, Busan (Korea, Republic of); Kim, Wontaek, E-mail: rokwt@hanmail.net [Department of Radiation Oncology, Pusan National University School of Medicine, Busan (Korea, Republic of); Nam, Jiho; Kim, Donghyun; Lee, Juhye; Park, Dahl; Jeon, Hosang [Department of Radiation Oncology, Pusan National University School of Medicine, Busan (Korea, Republic of); Ha, Honggu; Kim, Taenam [Department of Urology, Medical Research Institute, Pusan National University Hospital, Pusan National University School of Medicine, Busan (Korea, Republic of); Kim, Dongwon [Department of Radiation Oncology, Pusan National University School of Medicine, Busan (Korea, Republic of)

    2013-11-15

    Purpose: To investigate the effect of the probiotic Lactobacillus acidophilus on the percentage volume change of the rectum (PVC{sub R}), a crucial factor of prostate movement. Methods and Materials: Prostate cancer patients managed with tomotherapy as a radical treatment were enrolled in the study to take a probiotic capsule containing 1.0 × 10{sup 8} colony-forming units of L acidophilus or a placebo capsule twice daily. Radiation therapy was performed at a dose of 78 Gy in 39 fractions. The PVC{sub R}, defined as the difference in rectal volume between the planning computed tomographic (CT) and daily megavoltage CT images, was analyzed. Results: Forty patients were randomized into 2 groups. The L acidophilus group showed significantly lower median rectal volume and median PVC{sub R} values than the placebo group. L acidophilus showed a significant reduction effect on the PVC{sub R} (P<.001). However, the radiation therapy fraction number did not significantly influence the PVC{sub R}. Conclusions: L acidophilus was useful in reducing the PVC{sub R}, which is the most important determining factor of prostate position, during radiation therapy for prostate cancer.

  12. Analytical solutions for the coefficient of variation of the volume-averaged solute concentration in heterogeneous aquifers

    Science.gov (United States)

    Kabala, Z. J.

    1997-08-01

    Under the assumption that local solute dispersion is negligible, a new general formula (in the form of a convolution integral) is found for the arbitrary k-point ensemble moment of the local concentration of a solute convected in arbitrary m spatial dimensions with general sure initial conditions. From this general formula new closed-form solutions in m=2 spatial dimensions are derived for 2-point ensemble moments of the local solute concentration for the impulse (Dirac delta) and Gaussian initial conditions. When integrated over an averaging window, these solutions lead to new closed-form expressions for the first two ensemble moments of the volume-averaged solute concentration and to the corresponding concentration coefficients of variation (CV). Also, for the impulse (Dirac delta) solute concentration initial condition, the second ensemble moment of the solute point concentration in two spatial dimensions and the corresponding CV are demonstrated to be unbound. For impulse initial conditions the CVs for volume-averaged concentrations axe compared with each other for a tracer from the Borden aquifer experiment. The point-concentration CV is unacceptably large in the whole domain, implying that the ensemble mean concentration is inappropriate for predicting the actual concentration values. The volume-averaged concentration CV decreases significantly with an increasing averaging volume. Since local dispersion is neglected, the new solutions should be interpreted as upper limits for the yet to be derived solutions that account for local dispersion; and so should the presented CVs for Borden tracers. The new analytical solutions may be used to test the accuracy of Monte Carlo simulations or other numerical algorithms that deal with the stochastic solute transport. They may also be used to determine the size of the averaging volume needed to make a quasi-sure statement about the solute mass contained in it.

  13. THE EFFECT OF VOLUME VARIATION OF SILVER NANOPARTICLE SOLUTION TOWARDS THE POROSITY AND COMPRESSIVE STRENGTH OF MORTAR

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    W.S.B. Dwandaru

    2016-10-01

    Full Text Available As the world is growing rapidly, people need better building materials such as mortar. The aim of this research is to determine the effect of adding silver nanoparticle solution towards the porosity and compressive strength of mortar. This research was started by making silver nanoparticle solution from nitrate silver (AgNO3. The solution is then characterized using Uv-Vis spectrophotometer. 5 mM silver nanoparticle is added in the process of mortar production with volume variation of the silver nanoparticle solution. The porosity, compressive strength, and the content of mortar were determined by digital scale, universal testing machine, and X-ray diffraction, respectively. For silver nanoparticle solution volumes of (in mL 0, 5, 10, 15, 20, and 25 the porosity obtained are (in % 20.38, 19.48, 19.42, 18.9, 17.8, and 17.5, respectively. The best increase in compressive strength is obtained for (in MPa 29,068, 29,308, and 31,385, with nanoparticle solution volumes of (in mL 5, 10, and 15   Keywords: mortar, silver nanoparticle, compressive strength

  14. Genetic variations in the serotoninergic system contribute to amygdala volume in humans

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    Jin eLi

    2015-10-01

    Full Text Available The amygdala plays a critical role in emotion processing and psychiatric disorders associated with emotion dysfunction. Accumulating evidence suggests that amygdala structure is modulated by serotonin-related genes. However, there is a gap between the small contributions of single loci (less than 1% and the reported 63-65% heritability of amygdala structure. To understand the missing heritability, we systematically explored the contribution of serotonin genes on amygdala structure at the gene set level. The present study of 417 healthy Chinese volunteers examined 129 representative polymorphisms in genes from multiple biological mechanisms in the regulation of serotonin neurotransmission. A system-level approach using multiple regression analyses identified that nine SNPs collectively accounted for approximately 8% of the variance in amygdala volume. Permutation analyses showed that the probability of obtaining these findings by chance was low (p=0.043, permuted for 1000 times. Findings showed that serotonin genes contribute moderately to individual differences in amygdala volume in a healthy Chinese sample. These results indicate that the system-level approach can help us to understand the genetic basis of a complex trait such as amygdala structure.

  15. Effect of two volume responsiveness evaluation methods on fluid resuscitation and prognosis in septic shock patients

    Institute of Scientific and Technical Information of China (English)

    Xu Qianghong; Yan Jing; Cai Guolong; Chen Jin; Li Li; Hu Caibao

    2014-01-01

    Background Few studies have reported the effect of different volume responsiveness evaluation methods on volume therapy results and prognosis.This study was carried out to investigate the effect of two volume responsiveness evaluation methods,stroke volume variation (SW) and stroke volume changes before and after passive leg raising (PLR-ASV),on fluid resuscitation and prognosis in septic shock patients.Methods Septic shock patients admitted to the Department of Critical Care Medicine of Zhejiang Hospital,China,from March 2011 to March 2013,who were under controlled ventilation and without arrhythmia,were studied.Patients were randomly assigned to the SVV group or the PLR-ASV group.The SVV group used the Pulse Indication Continuous Cardiac Output monitoring of SW,and responsiveness was defined as SW->12%.The PLR-ASV group used ASV before and after PLR as the indicator,and responsiveness was defined as ASV >15%.Six hours after fluid resuscitation,changes in tissue perfusion indicators (lactate,lactate clearance rate,central venous oxygen saturation (SCVO2),base excess (BE)),organ function indicators (white blood cell count,neutrophil percentage,platelet count,total protein,albumin,alanine aminotransferase,total and direct bilirubin,blood urea nitrogen,serum creatinine,serum creatine kinase,oxygenation index),fluid balance (6-and 24-hour fluid input) and the use of cardiotonic drugs (dobutamine),prognostic indicators (the time and rate of achieving early goal-directed therapy (EGDT) standards,duration of mechanical ventilation and intensive care unit stay,and 28-day mortality) were observed.Results Six hours after fluid resuscitation,there were no significant differences in temperature,heart rate,blood pressure,SpO2,organ function indicators,or tissue perfusion indicators between the two groups (P >0.06).The 6-and 24-hour fluid input was slightly less in the SW group than in the PLR-ASV group,but the difference was not statistically significant (P >0

  16. Spleen Volume Variation in Patients with Locally Advanced Non-Small Cell Lung Cancer Receiving Platinum-Based Chemo-Radiotherapy.

    Science.gov (United States)

    Wen, Shu Wen; Everitt, Sarah J; Bedő, Justin; Chabrot, Marine; Ball, David L; Solomon, Benjamin; MacManus, Michael; Hicks, Rodney J; Möller, Andreas; Leimgruber, Antoine

    2015-01-01

    There is renewed interest in the immune regulatory role of the spleen in oncology. To date, very few studies have examined macroscopic variations of splenic volume in the setting of cancer, prior to or during therapy, especially in humans. Changes in splenic volume may be associated with changes in splenic function. The purpose of this study was to investigate variations in spleen volume in NSCLC patients during chemo-radiotherapy. Sixty patients with stage I-IIIB NSCLC underwent radiotherapy (60 Gy/30 fractions) for six weeks with concomitant carboplatin/paclitaxel (Ca/P; n = 32) or cisplatin/etoposide (Ci/E; n = 28). A baseline PET/CT scan was performed within 2 weeks prior to treatment and during Weeks 2 and 4 of chemo-radiotherapy. Spleen volume was measured by contouring all CT slices. Significant macroscopic changes in splenic volume occurred early after the commencement of treatment. A significant decrease in spleen volume was observed for 66% of Ca/P and 79% of Ci/E patients between baseline and Week 2. Spleen volume was decreased by 14.2% for Ca/P (pspleen volume was still significantly decreased for Ca/P patients compared to baseline, while for Ci/E patients, spleen volume returned to above baseline levels. This is the first report demonstrating macroscopic changes in the spleen in NSCLC patients undergoing radical chemo-radiotherapy that can be visualized by non-invasive imaging.

  17. 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.

  18. Arterial pressure variations as parameters of brain perfusion in response to central blood volume depletion and repletion

    Directory of Open Access Journals (Sweden)

    Anne-Sophie G.T. Bronzwaer

    2014-04-01

    Full Text Available Rationale:A critical reduction in central blood volume (CBV is often characterized by hemodynamic instability. Restoration of a volume deficit may be established by goal-directed fluid therapy guided by respiration-related variation in systolic- and pulse pressure (SPV and PPV. Stroke volume index (SVI serves as a surrogate end-point of a fluid challenge but tissue perfusion itself has not been addressed. Objective: To delineate the relationship between arterial pressure variations, SVI and regional brain perfusion during CBV depletion and repletion in spontaneously breathing volunteers. Methods: This study quantified in 14 healthy subjects (11 male the effects of CBV depletion (by 30 and 70 degrees passive head-up tilt (HUT and a fluid challenge (by tilt back on CBV (thoracic admittance, mean middle cerebral artery (MCA blood flow velocity (Vmean, SVI, cardiac index (CI , PPV and SPV. Results: PPV (103±89%, p< 0.05 and SPV (136±117%, p< 0.05 increased with progression of central hypovolemia manifested by a reduction in thoracic admittance (11±5%, p< 0.001, SVI (28±6%, p< 0.001, CI (6±8%, p< 0.001 and MCAVmean (17±7%, p< 0.05 but not in arterial pressure. The reduction in MCAVmean correlated to the fall in SVI (R2=0.52, p< 0.0001 and inversely to PPV and SPV (R2=0.46 (p< 0.0001 and R2=0.45 (p< 0.0001, respectively. PPV and SPV predicted a ≥15% reduction in MCAVmean and SVI with comparable sensitivity (67%/ 67% vs. 63%/ 68% respectively and specificity (89%/94% vs. 89%/94%, respectively. A rapid fluid challenge by tilt-back restored all parameters to baseline values within one minute. Conclusion: In spontaneously breathing subjects, a reduction in MCAVmean was related to an increase in PPV and SPV during graded CBV depletion and repletion. Specifically, PPV and SPV predicted changes in both SVI and MCAVmean with comparable sensitivity and specificity, however the predictive value is limited in spontaneously breathing subjects.

  19. The interstitial nuclei of the human anterior hypothalamus: an investigation of sexual variation in volume and cell size, number and density.

    Science.gov (United States)

    Byne, W; Lasco, M S; Kemether, E; Shinwari, A; Edgar, M A; Morgello, S; Jones, L B; Tobet, S

    2000-02-21

    The four interstitial nuclei of the anterior hypothalamus (INAH) have been considered as candidate human nuclei for homology with the much studied sexually dimorphic nucleus of the preoptic area of the rat. Assessment of the INAH for sexual dimorphism has produced discrepant results. This study reports the first systematic examination of all four INAH in the human for sexual variation in volume, neuronal number and neuronal size. Serial Nissl-stained coronal sections through the medial preoptic area and anterior hypothalamus were examined from 18 males and 20 females who died between the ages of 17 and 65 without evidence of hypothalamic pathology or infection with the human immunodeficiency virus. A computer-assisted image-analysis system and commercial stereology software package were employed to assess total volume, neuronal number and mean neuronal size for each INAH. INAH3 occupied a significantly greater volume and contained significantly more neurons in males than in females. No sex differences in volume were detected for any of the other INAH. No sexual variation in neuronal size or packing density was observed in any nucleus. The present data corroborate two previous reports of sexual dimorphism of INAH3 but provide no support for previous reports of sexual variation in other INAH.

  20. Lagrange-type modeling of continuous dielectric permittivity variation in double-higher-order volume integral equation method

    Science.gov (United States)

    Chobanyan, E.; Ilić, M. M.; Notaroš, B. M.

    2015-05-01

    A novel double-higher-order entire-domain volume integral equation (VIE) technique for efficient analysis of electromagnetic structures with continuously inhomogeneous dielectric materials is presented. The technique takes advantage of large curved hexahedral discretization elements—enabled by double-higher-order modeling (higher-order modeling of both the geometry and the current)—in applications involving highly inhomogeneous dielectric bodies. Lagrange-type modeling of an arbitrary continuous variation of the equivalent complex permittivity of the dielectric throughout each VIE geometrical element is implemented, in place of piecewise homogeneous approximate models of the inhomogeneous structures. The technique combines the features of the previous double-higher-order piecewise homogeneous VIE method and continuously inhomogeneous finite element method (FEM). This appears to be the first implementation and demonstration of a VIE method with double-higher-order discretization elements and conformal modeling of inhomogeneous dielectric materials embedded within elements that are also higher (arbitrary) order (with arbitrary material-representation orders within each curved and large VIE element). The new technique is validated and evaluated by comparisons with a continuously inhomogeneous double-higher-order FEM technique, a piecewise homogeneous version of the double-higher-order VIE technique, and a commercial piecewise homogeneous FEM code. The examples include two real-world applications involving continuously inhomogeneous permittivity profiles: scattering from an egg-shaped melting hailstone and near-field analysis of a Luneburg lens, illuminated by a corrugated horn antenna. The results show that the new technique is more efficient and ensures considerable reductions in the number of unknowns and computational time when compared to the three alternative approaches.

  1. Bone volume fraction explains the variation in strength and stiffness of cancellous bone affected by metastatic cancer and osteoporosis.

    Science.gov (United States)

    Nazarian, Ara; von Stechow, Dietrich; Zurakowski, David; Müller, Ralph; Snyder, Brian D

    2008-12-01

    Preventing nontraumatic fractures in millions of patients with osteoporosis or metastatic cancer may significantly reduce the associated morbidity and reduce health-care expenditures incurred by these fractures. Predicting fracture occurrence requires an accurate understanding of the relationship between bone structure and the mechanical properties governing bone fracture that can be readily measured. The aim of this study was to test the hypothesis that a single analytic relationship with either bone tissue mineral density or bone volume fraction (BV/TV) as independent variables could predict the strength and stiffness of normal and pathologic cancellous bone affected by osteoporosis or metastatic cancer. After obtaining institutional review board approval and informed consent, 15 patients underwent excisional biopsy of metastatic prostate, breast, lung, ovarian, or colon cancer from the spine and/or femur to obtain 41 metastatic cancer specimens. In addition, 96 noncancer specimens were excised from 43 age- and site-matched cadavers. All specimens were imaged using micro-computed tomography (micro-CT) and backscatter emission imaging and tested mechanically by uniaxial compression and nanoindentation. The minimum BV/TV, measured using quantitative micro-CT, accounted for 84% of the variation in bone stiffness and strength for all cancellous bone specimens. While relationships relating bone density to strength and stiffness have been derived empirically for normal and osteoporotic bone, these relationships have not been applied to skeletal metastases. This simple analytic relationship will facilitate large-scale screening and prediction of fracture risk for normal and pathologic cancellous bone using clinical CT systems to determine the load capacity of bones altered by metastatic cancer, osteoporosis, or both.

  2. Fluid management guided by stroke volume variation failed to decrease the incidence of acute kidney injury, 30-day mortality, and 1-year survival in living donor liver transplant recipients

    Directory of Open Access Journals (Sweden)

    Shen-Chih Wang

    2012-12-01

    Conclusion: The outcomes of living donor liver transplant patients who had fluid therapy guided by an SVV less than 10% were similar to those of patients who were given fluids to reach a CVP of 10 mmHg. Our findings suggest that the two measures of vascular filling are similar in liver transplant recipients with demographic characteristics similar to those of our patients.

  3. [Hospital variation in anastomotic leakage after rectal cancer surgery in the Spanish Association of Surgeons project: The contribution of hospital volume].

    Science.gov (United States)

    Ortiz, Héctor; Biondo, Sebastiano; Codina, Antonio; Ciga, Miguel Á; Enríquez-Navascués, José; Espín, Eloy; García-Granero, Eduardo; Roig, José Vicente

    2016-04-01

    This multicentre observational study aimed to determine the anastomotic leak rate in the hospitals included in the Rectal Cancer Project of the Spanish Society of Surgeons and examine whether hospital volume may contribute to any variation between hospitals. Hospital variation was quantified using a multilevel approach on prospective data derived from the multicentre database of all adenocarcinomas of the rectum operated by an anterior resection at 84 surgical departments from 2006 to 2013. The following variables were included in the analysis; demographics, American Society of Anaesthesiologists classification, use of defunctioning stoma, tumour location and stage, administration of neoadjuvant treatment, and annual volume of elective surgical procedures. A total of 7231 consecutive patients were included. The rate of anastomotic leak was 10.0%. Stratified by annual surgical volume hospitals varied from 9.9 to 11.3%. In multilevel regression analysis, the risk of anastomotic leak increased in male patients, in patients with tumours located below 12 cm from the anal verge, and advanced tumour stages. However, a defunctioning stoma seemed to prevent this complication. Hospital surgical volume was not associated with anastomotic leak (OR: 0.852, [0.487-1.518]; P=.577). Furthermore, there was a statistically significant variation in anastomotic leak between all departments (MOR: 1.475; [1.321-1.681]; P<0.001). Anastomotic leak varies significantly among hospitals included in the project and this difference cannot be attributed to the annual surgical volume. Copyright © 2015 AEC. Publicado por Elsevier España, S.L.U. All rights reserved.

  4. SU-C-210-06: Quantitative Evaluation of Dosimetric Effects Resulting From Positional Variations of Pancreatic Tumor Volumes

    Energy Technology Data Exchange (ETDEWEB)

    Yu, S; Sehgal, V; Wei, R; Lawrenson, L; Kuo, J; Hanna, N; Ramsinghani, N; Daroui, P; Al-Ghazi, M [University of California, Orange, CA (United States)

    2015-06-15

    Purpose: The aim of this study is to quantify dosimetric effects resulting from variation in pancreatic tumor position assessed by bony anatomy and implanted fiducial markers Methods: Twelve pancreatic cancer patients were retrospectively analyzed for this study. All patients received modulated arc therapy (VMAT) treatment using fiducial-based Image Guided Radiation Therapy (IGRT) to the intact pancreas. Using daily orthogonal kV and/or Cone beam CT images, the shift needed to co-register the daily pre-treatment images to reference CT from fiducial to bone (Fid-Bone) were recorded as Left-Right (LR), Anterior-Posterior (AP) and Superior-Inferior (SI). The original VMAT plan iso-center was shifted based on KV bone matching positions at 5 evenly spaced fractions. Dose coverage of the planning target volumes (PTVs) (V100%), mean dose to liver, kidney and stomach/duodenum were assessed in the modified plans. Results: A total of 306 fractions were analyzed. The absolute fiducial-bone positional shifts were greatest in the SI direction, (AP = 2.7 ± 3.0, LR = 2.8 ± 2.8, and SI 6.3 ± 7.9 mm, mean ± SD). The V100% was significantly reduced by 13.5%, (Fid-Bone = 95.3 ± 2.0 vs. 82.3 ± 11.8%, p=0.02). This varied widely among patients (Fid-Bone V100% Range = 2–60%), where 33% of patients had a reduction in V100% of more than 10%. The impact on OARs was greatest to the liver (Fid-Bone= 14.6 vs. 16.1 Gy, 10%), and stomach, (Fid-Bone = 23.9 vx. 25.5 Gy, 7%), however was not statistically significant (p=0.10 both). Conclusion: Compared to matching by fiducial markers, matching by bony anatomy would have substantially reduced the PTV coverage by 13.5%. This reinforces the importance of online position verification based on fiducial markers. Hence, implantation of fiducial markers is strongly recommended for pancreatic cancer patients undergoing intensity modulated radiation therapy treatments.

  5. RESULTS FROM EPA FUNDED RESEARCH PROGRAMS ON THE IMPORTANCE OF PURGE VOLUME, SAMPLE VOLUME, SAMPLE FLOW RATE AND TEMPORAL VARIATIONS ON SOIL GAS CONCENTRATIONS

    Science.gov (United States)

    Two research studies funded and overseen by EPA have been conducted since October 2006 on soil gas sampling methods and variations in shallow soil gas concentrations with the purpose of improving our understanding of soil gas methods and data for vapor intrusion applications. Al...

  6. Goal-directed fluid optimization based on stroke volume variation and cardiac index during one-lung ventilation in patients undergoing thoracoscopy lobectomy operations: a pilot study

    Directory of Open Access Journals (Sweden)

    Jian Zhang

    2013-07-01

    Full Text Available OBJECTIVES: This pilot study was designed to utilize stroke volume variation and cardiac index to ensure fluid optimization during one-lung ventilation in patients undergoing thoracoscopic lobectomies. METHODS: Eighty patients undergoing thoracoscopic lobectomy were randomized into either a goal-directed therapy group or a control group. In the goal-directed therapy group, the stroke volume variation was controlled at 10%±1%, and the cardiac index was controlled at a minimum of 2.5 L.min-1.m-2. In the control group, the MAP was maintained at between 65 mm Hg and 90 mm Hg, heart rate was maintained at between 60 BPM and 100 BPM, and urinary output was greater than 0.5 mL/kg-1/h-1. The hemodynamic variables, arterial blood gas analyses, total administered fluid volume and side effects were recorded. RESULTS: The PaO2/FiO2-ratio before the end of one-lung ventilation in the goal-directed therapy group was significantly higher than that of the control group, but there were no differences between the goal-directed therapy group and the control group for the PaO2/FiO2-ratio or other arterial blood gas analysis indices prior to anesthesia. The extubation time was significantly earlier in the goal-directed therapy group, but there was no difference in the length of hospital stay. Patients in the control group had greater urine volumes, and they were given greater colloid and overall fluid volumes. Nausea and vomiting were significantly reduced in the goal-directed therapy group. CONCLUSION: The results of this study demonstrated that an optimization protocol, based on stroke volume variation and cardiac index obtained with a FloTrac/Vigileo device, increased the PaO2/FiO2-ratio and reduced the overall fluid volume, intubation time and postoperative complications (nausea and vomiting in thoracic surgery patients requiring one-lung ventilation.

  7. Variations in target volume definition for postoperative radiotherapy in stage III non-small-cell lung cancer: analysis of an international contouring study.

    Science.gov (United States)

    Spoelstra, Femke O B; Senan, Suresh; Le Péchoux, Cecile; Ishikura, Satoshi; Casas, Francesc; Ball, David; Price, Allan; De Ruysscher, Dirk; van Sörnsen de Koste, John R

    2010-03-15

    Postoperative radiotherapy (PORT) in patients with completely resected non-small-cell lung cancer with mediastinal involvement is controversial because of the failure of earlier trials to demonstrate a survival benefit. Improved techniques may reduce toxicity, but the treatment fields used in routine practice have not been well studied. We studied routine target volumes used by international experts and evaluated the impact of a contouring protocol developed for a new prospective study, the Lung Adjuvant Radiotherapy Trial (Lung ART). Seventeen thoracic radiation oncologists were invited to contour their routine clinical target volumes (CTV) for 2 representative patients using a validated CD-ROM-based contouring program. Subsequently, the Lung ART study protocol was provided, and both cases were contoured again. Variations in target volumes and their dosimetric impact were analyzed. Routine CTVs were received for each case from 10 clinicians, whereas six provided both routine and protocol CTVs for each case. Routine CTVs varied up to threefold between clinicians, but use of the Lung ART protocol significantly decreased variations. Routine CTVs in a postlobectomy patient resulted in V(20) values ranging from 12.7% to 54.0%, and Lung ART protocol CTVs resulted in values of 20.6% to 29.2%. Similar results were seen for other toxicity parameters and in the postpneumectomy patient. With the exception of upper paratracheal nodes, protocol contouring improved coverage of the required nodal stations. Even among experts, significant interclinician variations are observed in PORT fields. Inasmuch as contouring variations can confound the interpretation of PORT results, mandatory quality assurance procedures have been incorporated into the current Lung ART study. Copyright 2010 Elsevier Inc. All rights reserved.

  8. Cerebral gray matter volume variation in female-to-male transsexuals: a voxel-based morphometric study.

    Science.gov (United States)

    Kim, Tae-Hoon; Kim, Seok-Kwun; Jeong, Gwang-Woo

    2015-12-16

    Several studies seem to support the hypothesis that brain anatomy is associated with transsexualism. However, these studies were still limited because few neuroanatomical findings have been obtained from female-to-male (FtM) transsexuals. This study compared the cerebral regional volumes of gray matter (GM) between FtM transsexuals and female controls using a voxel-based morphometry. Twelve FtM transsexuals who had undergone sex-reassignment surgery and 15 female controls participated in this study. Both groups were age matched and right-handed, with no history of neurological illness. Fifteen female controls were recruited to determine whether GM volumes in FtM transsexuals more closely resembled individuals who shared their biological sex. MRI data were processed using SPM 8 with the diffeomorphic anatomical registration through exponentiated Lie algebra (DARTEL). FtM transsexuals showed significantly larger volumes of the thalamus, hypothalamus, midbrain, gyrus rectus, head of caudate nucleus, precentral gyrus, and subcallosal area compared with the female controls. However, the female controls showed a significantly larger volume in the superior temporal gyrus including Heschl's gyrus and Rolandic operculum. These findings confirm that the volume difference in brain substructures in FtM transsexuals is likely to be associated with transsexualism and that transsexualism is probably associated with distinct cerebral structures, determining gender identity.

  9. X Chromosome inactivation pattern is not associated with interindividual variations in thyroid volume: a study of euthyroid danish female twins

    DEFF Research Database (Denmark)

    Brix, Thomas Heiberg; Hansen, Pia Skov; Bennedbak, Finn Noe

    2009-01-01

    Ahigher frequency of skewed X chromosome inactivation (XCI) is found in patients with autoimmune thyroid disease (AITD) than in controls. Although goitre is often present in AITD, a recent study failed to show an association between XCI and clinically overt nontoxic goitre. However, the etiology...... of overt goitre is complex, and the mechanisms influencing thyroid volume may involve fewer factors than the mechanisms underlying overt goitre. In order to examine the impact of XCI on thyroid volume in euthyroid females, we studied whether within cohort (n = 138) and within twin pair (n = 69) differences...

  10. Substantial interobserver variation of thyroid volume and function by visual evaluation of thyroid (99m)Tc scintigraphy

    DEFF Research Database (Denmark)

    Soelberg, Kerstin; Grupe, Peter; Boel-Jørgensen, Henrik

    2014-01-01

    (99m)Tc-pertechnetate scintigraphy is much used in the evaluation of patients with nodular goitre. We investigated the ability of experienced observers to estimate the thyroid 24-h (131)I uptake (RAIU) and the thyroid volume by visual evaluation of the scintigram.......(99m)Tc-pertechnetate scintigraphy is much used in the evaluation of patients with nodular goitre. We investigated the ability of experienced observers to estimate the thyroid 24-h (131)I uptake (RAIU) and the thyroid volume by visual evaluation of the scintigram....

  11. Substantial interobserver variation of thyroid volume and function by visual evaluation of thyroid (99m)Tc scintigraphy

    DEFF Research Database (Denmark)

    Soelberg, Kerstin; Grupe, Peter; Boel-Jørgensen, Henrik

    2014-01-01

    (99m)Tc-pertechnetate scintigraphy is much used in the evaluation of patients with nodular goitre. We investigated the ability of experienced observers to estimate the thyroid 24-h (131)I uptake (RAIU) and the thyroid volume by visual evaluation of the scintigram.......(99m)Tc-pertechnetate scintigraphy is much used in the evaluation of patients with nodular goitre. We investigated the ability of experienced observers to estimate the thyroid 24-h (131)I uptake (RAIU) and the thyroid volume by visual evaluation of the scintigram....

  12. Variation in Brain Morphology of Intertidal Gobies: A Comparison of Methodologies Used to Quantitatively Assess Brain Volumes in Fish.

    Science.gov (United States)

    White, Gemma E; Brown, Culum

    2015-01-01

    When correlating brain size and structure with behavioural and environmental characteristics, a range of techniques can be utilised. This study used gobiid fishes to quantitatively compare brain volumes obtained via three different methods; these included the commonly used techniques of histology and approximating brain volume to an idealised ellipsoid, and the recently established technique of X-ray micro-computed tomography (micro-CT). It was found that all three methods differed significantly from one another in their volume estimates for most brain lobes. The ellipsoid method was prone to over- or under-estimation of lobe size, histology caused shrinkage in the telencephalon, and although micro-CT methods generated the most reliable results, they were also the most expensive. Despite these differences, all methods depicted quantitatively similar relationships among the four different species for each brain lobe. Thus, all methods support the same conclusions that fishes inhabiting rock pool and sandy habitats have different patterns of brain organisation. In particular, fishes from spatially complex rock pool habitats were found to have larger telencephalons, while those from simple homogenous sandy shores had a larger optic tectum. Where possible we recommend that micro-CT be used in brain volume analyses, as it allows for measurements without destruction of the brain and fast identification and quantification of individual brain lobes, and minimises many of the biases resulting from the histology and ellipsoid methods. © 2015 S. Karger AG, Basel.

  13. Variations in Rectal Volumes and Dosimetry Values Including NTCP due to Interfractional Variability When Administering 2D-Based IG-IMRT for Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Takashi Hanada

    2014-01-01

    Full Text Available We estimated variations in rectal volumes and dosimetry values including NTCP with interfractional motion during prostate IG-IMRT. Rectal volumes, DVH parameters, and NTCPs of 20 patients were analyzed. For this patient population, the median (range volume on the initial plan for the rectum was 45.6 cc (31.3–82.0, showing on-treatment spread around the initial prediction based on the initial plan. DVH parameters of on-treatment CBCT analyses showed systematic regularity shift from the prediction based on the initial plan. Using the Lyman-Kutcher-Burman model, NTCPs of predicted late rectal bleeding toxicity of rectal grade ≥ 2 (RTOG and the QUANTEC update rectal toxicity for the prediction based on the initial plan were 0.09% (0.02–0.24 and 0.02% (0.00–0.07, respectively, with NTCPs from on-treatment CBCT analyses being 0.35% (0.01–6.16 and 0.12% (0.00–4.11, respectively. Using the relative seriality model, for grade ≥ 2 bleeding rectal toxicity, NTCP of the prediction based on the initial plan was 0.64% (0.15–1.22 versus 1.48% (0.18–7.66 for on-treatment CBCT analysis. Interfraction variations in rectal volumes occur in all patients due to physiological changes. Thus, rectal assessment during 2D-based IG-IMRT using NTCP models has the potential to provide useful and practical dosimetric verification.

  14. Nano-liter droplet libraries from a pipette: step emulsificator that stabilizes droplet volume against variation in flow rate.

    Science.gov (United States)

    Dutka, Filip; Opalski, Adam S; Garstecki, Piotr

    2016-05-24

    Many modern analytical assays, for example, droplet digital PCR, or screening of the properties of single cells or single mutated genes require splitting a liquid sample into a number of small (typically ca. nano-liter in volume) independent compartments or droplets. This calls for a method that would allow splitting small (microliter) samples of liquid into libraries of nano-liter droplets without any dead volume or waste. Step emulsification allows for facile protocols that require delivery of only the sample liquid, yet they typically exhibit dependence of the droplet size on the rate at which the sample is injected. Here, we report a novel microfluidic junction that reduces the dependence of the volume of droplets on the rate of injection. We also demonstrate generation of tightly monodisperse nanoliter droplets by introduction of solely the dispersed phase into the system from an automatic pipette. The method presented here can readily be used and can replace the sophisticated devices typically used to generate libraries of nano-liter droplets from liquid samples.

  15. Effect of allelic variations at the Glu-D1, Glu-A3, Glu-B3 and Pinb-D1 loci on flour characteristics and bread loaf volume

    Science.gov (United States)

    Doubled haploid wheat lines developed from a cross between Keumkang, a hard white winter wheat, and Olgeuru, soft red winter wheat were used to determine the effects of allelic variation in Glu-D1, Glu-A3, Glu-B3 and Pinb-D1 loci on physiochemical properties of flour and bread loaf volume. Variation...

  16. Reducing uncertainty in the selection of bi-variate distributions of flood peaks and volumes using copulas and hydrological process-based model selection

    Science.gov (United States)

    Szolgay, Jan; Gaál, Ladislav; Bacigál, Tomáš; Kohnová, Silvia; Blöschl, Günter

    2016-04-01

    Bi-variate distributions of flood peaks and flood event volumes are needed for a range of practical purposes including e.g. retention basin design and identifying extent and duration of flooding in flood hazard zones. However, the selection of the types of bi-variate distributions and estimating their parameters from observed peak-volume pairs are associated with far larger uncertainties compared to uni-variate distributions, since observed flood records of required length are rarely available. This poses a serious problem to reliable flood risk estimation in bi-variate design cases. The aim of this contribution was to shed light on the possibility of reducing uncertainties in the estimation of the dependence models/parameters from a regional perspective. The peak-volume relationships were modeled in terms of copulas. Flood events were classified according to their origin. In order to reduce the uncertainty in estimating flood risk, pooling and analyzing catchments of similar behavior according to flood process types was attempted. Most of the work reported in the literature so far did not direct the multivariate analysis toward discriminating certain types of models regionally according to specific runoff generation processes. Specifically, the contribution addresses these problems: - Are the peak-volume relationships of different flood types for a given catchment similar? - Are the peak-volume dependence structures between catchments in a larger region for given flood types similar? - Are some copula types more suitable for given flood process types and does this have consequences for reliable risk estimation? The target region is located in the northern parts of Austria, and consists of 72 small and mid-sized catchments. Instead of the traditional approach that deals with annual maximum floods, the current analysis includes all independent flood events in the region. 24 872 flood events from the period 1976-2007 were identified, and classified as synoptic, flash

  17. Seasonal and spatial distribution of Bacterioplankton in a fluvial-lagunar system of a tropical region: density, biomass, cellular volume and morphologic variation

    Directory of Open Access Journals (Sweden)

    Magnólia Fernandes Florêncio de Araújo

    2008-02-01

    Full Text Available The temporal and spatial fluctuations of Bacterioplankton in a fluvial-lagunar system of a tropical region (Pitimbu River and Jiqui Lake, RN were studied during the dry and the rainy periods. The bacterial abundance varied from 2.67 to 5.1 Cells10(7mL-1 and did not show a typical temporal variation, presenting only small oscillations between the rainy and the dry periods. The bacterial biomass varied from 123 µgC L-1 to 269 µgC L-1 in the sampling sites and the average cellular volume varied from 0.12 to 0.54µm³, showing a predominance of the rods. The temperature showed a positive correlation with the cellular volume of the rods (R=0.55; p=0.02 and vibrio (R=0.53; p=0.03. Significant spatial differences of biomass (Mann Whitney: p=0.01 and cellular volume of the morphotypes (Mann Whitney: p=0.003 were found between the sampling sites. The strong positive correlations of the water temperature and oxygen with bacterioplankton showed a probable high bacterial activity in this system.A variação temporal e espacial do bacterioplâncton em um sistema fluvial-lagunar de região tropical foi estudada em períodos seco e chuvoso. As médias da abundância bacteriana variaram de 2,67 a 5,1 x 10(7 e não exibiram uma variação temporal marcante, tendo apresentado apenas pequenas oscilações entre os períodos chuvoso e seco. A biomassa bacteriana variou de 123 µg C L-1 a 269 µg C L-1 entre os locais de coleta e o volume celular médio de 0,12µm³ a 0,54µm³, ocorrendo predominância de bacilos. A temperatura mostrou correlação positiva com o volume celular de bacilos (R=0,55; p=0,02 e de vibriões (R=0,53; p=0,03. Foram encontradas diferenças espaciais significativas de biomassa (Mann Whitney: p=0,01 e volume celular dos morfotipos (Mann Whitney: p= 0,003, entre os locais de coleta. As fortes correlações positivas da temperatura da água e do oxigênio, com o bacterioplâncton, são sugestivas de uma provavelmente elevada atividade

  18. NMR imaging estimates of muscle volume and intramuscular fat infiltration in the thigh: variations with muscle, gender, and age.

    Science.gov (United States)

    Hogrel, Jean-Yves; Barnouin, Yoann; Azzabou, Noura; Butler-Browne, Gillian; Voit, Thomas; Moraux, Amélie; Leroux, Gaëlle; Behin, Anthony; McPhee, Jamie S; Carlier, Pierre G

    2015-06-01

    Muscle mass is particularly relevant to follow during aging, owing to its link with physical performance and autonomy. The objectives of this work were to assess muscle volume (MV) and intramuscular fat (IMF) for all the muscles of the thigh in a large population of young and elderly healthy individuals using magnetic resonance imaging (MRI) to test the effect of gender and age on MV and IMF and to determine the best representative slice for the estimation of MV and IMF. The study enrolled 105 healthy young (range 20-30 years) and older (range 70-80 years) subjects. MRI scans were acquired along the femur length using a three-dimension three-point Dixon proton density-weighted gradient echo sequence. MV and IMF were estimated from all the slices. The effects of age and gender on MV and IMF were assessed. Predictive equations for MV and IMF were established using a single slice at various femur levels for each muscle in order to reduce the analysis process. MV was decreased with aging in both genders, particularly in the quadriceps femoris. IMF was largely increased with aging in men and, to a lesser extent, in women. Percentages of MV decrease and IMF increase with aging varied according to the muscle. Predictive equations to predict MV and IMF from single slices are provided and were validated. This study is the first one to provide muscle volume and intramuscular fat infiltration in all the muscles of the thigh in a large population of young and elderly healthy subjects.

  19. A molecular dynamics study of ambient and high pressure phases of silica: Structure and enthalpy variation with molar volume

    Science.gov (United States)

    Rajappa, Chitra; Sringeri, S. Bhuvaneshwari; Subramanian, Yashonath; Gopalakrishnan, J.

    2014-06-01

    Extensive molecular dynamics studies of 13 different silica polymorphs are reported in the isothermal-isobaric ensemble with the Parrinello-Rahman variable shape simulation cell. The van Beest-Kramer-van Santen (BKS) potential is shown to predict lattice parameters for most phases within 2%-3% accuracy, as well as the relative stabilities of different polymorphs in agreement with experiment. Enthalpies of high-density polymorphs - CaCl2-type, α-PbO2-type, and pyrite-type - for which no experimental data are available as yet, are predicted here. Further, the calculated enthalpies exhibit two distinct regimes as a function of molar volume—for low and medium-density polymorphs, it is almost independent of volume, while for high-pressure phases a steep dependence is seen. A detailed analysis indicates that the increased short-range contributions to enthalpy in the high-density phases arise not only from an increased coordination number of silicon but also shorter Si-O bond lengths. Our results indicate that amorphous phases of silica exhibit better optimization of short-range interactions than crystalline phases at the same density while the magnitude of Coulombic contributions is lower in the amorphous phase.

  20. Effect of fluid loading with normal saline and 6% hydroxyethyl starch on stroke volume variability and left ventricular volume

    Directory of Open Access Journals (Sweden)

    Kanda H

    2015-09-01

    Full Text Available Hirotsugu Kanda,1 Yuji Hirasaki,2 Takafumi Iida,1 Megumi Kanao,1 Yuki Toyama,1 Takayuki Kunisawa,1 Hiroshi Iwasaki,11Department of Anesthesiology and Critical Care Medicine, Asahikawa Medical University, Asahikawa, 2Department of Anatomy, The Jikei University Graduate School of Medicine, Tokyo, JapanPurpose: The aim of this clinical trial was to investigate changes in stroke volume variability (SVV and left ventricular end-diastolic volume (LVEDV after a fluid bolus of crystalloid or colloid using real-time three-dimensional transesophageal echocardiography (3D-TEE and the Vigileo-FloTrac™ system.Materials and methods: After obtaining Institutional Review Board approval, and informed consent from the research participants, 22 patients undergoing scheduled peripheral vascular bypass surgery were enrolled in the study. The patients were randomly assigned to receive 500 mL of hydroxyethyl starch (HES; HES group, n=11 or normal saline (Saline group, n=11 for fluid replacement therapy. SVV was measured using the Vigileo-FloTrac system. LVEDV, stroke volume, and cardiac output were measured by 3D-TEE. The measurements were performed over 30 minutes before and after the fluid bolus in both groups.Results: SVV significantly decreased after fluid bolus in both groups (HES group, 14.7%±2.6% to 6.9%±2.7%, P<0.001; Saline group, 14.3%±3.9% to 8.8%±3.1%, P<0.001. LVEDV significantly increased after fluid loading in the HES group (87.1±24.0 mL to 99.9±27.2 mL, P<0.001, whereas no significant change was detected in the Saline group (88.8±17.3 mL to 91.4±17.6 mL, P>0.05. Stroke volume significantly increased after infusion in the HES group (50.6±12.5 mL to 61.6±19.1 mL, P<0.01 but not in the Saline group (51.6±13.4 mL to 54.1±12.8 mL, P>0.05. Cardiac output measured by 3D-TEE significantly increased in the HES group (3.5±1.1 L/min to 3.9±1.3 L/min, P<0.05, whereas no significant change was seen in the Saline group (3.4±1.1 L/min to 3.3±1.0 L

  1. Improved CT-based estimate of pulmonary gas trapping accounting for scanner and lung-volume variations in a multicenter asthmatic study.

    Science.gov (United States)

    Choi, Sanghun; Hoffman, Eric A; Wenzel, Sally E; Castro, Mario; Lin, Ching-Long

    2014-09-15

    Lung air trapping is estimated via quantitative computed tomography (CT) using density threshold-based measures on an expiration scan. However, the effects of scanner differences and imaging protocol adherence on quantitative assessment are known to be problematic. This study investigates the effects of protocol differences, such as using different CT scanners and breath-hold coaches in a multicenter asthmatic study, and proposes new methods that can adjust intersite and intersubject variations. CT images of 50 healthy subjects and 42 nonsevere and 52 severe asthmatics at total lung capacity (TLC) and functional residual capacity (FRC) were acquired using three different scanners and two different coaching methods at three institutions. A fraction threshold-based approach based on the corrected Hounsfield unit of air with tracheal density was applied to quantify air trapping at FRC. The new air-trapping method was enhanced by adding a lung-shaped metric at TLC and the lobar ratio of air-volume change between TLC and FRC. The fraction-based air-trapping method is able to collapse air-trapping data of respective populations into distinct regression lines. Relative to a constant value-based clustering scheme, the slope-based clustering scheme shows the improved performance and reduced misclassification rate of healthy subjects. Furthermore, both lung shape and air-volume change are found to be discriminant variables for differentiating among three populations of healthy subjects and nonsevere and severe asthmatics. In conjunction with the lung shape and air-volume change, the fraction-based measure of air trapping enables differentiation of severe asthmatics from nonsevere asthmatics and nonsevere asthmatics from healthy subjects, critical for the development and evaluation of new therapeutic interventions.

  2. Magma Chamber Model of Batur Caldera, Bali, Indonesia: Compositional Variation of Two Facies, Large-Volume Dacitic Ignimbrites

    Directory of Open Access Journals (Sweden)

    Igan S. Sutawidjaja

    2015-05-01

    Full Text Available DOI:10.17014/ijog.2.2.111-124Batur is one of the finest known calderas on Earth, and is the source of at least two major ignimbrite eruptions with a combined volume of some 84 km3 and 19 km3. These ignimbrites have a similar compositions, raising the question of whether they are geneticaly related. The Batur Ignimbrite-1 (BI-1 is crystal poor, containing rhyodacitic (68 - 70wt % SiO2, white to grey pumices and partly welded and unwelded. The overlying Batur Ignimbrite-2 (BI-2 is a homogeneous grey to black dacitic pumices (64 - 66 wt % SiO2, unwelded and densely welded (40 - 60% vesicularity, crystal and lithic rich. Phase equilibria indicate that the Batur magma equilibrated at temperatures of 1100 - 1300oC with melt water contents of 3 - 6 wt%. The post-eruptive Batur magma was cooler (<1100oC and it is melt more water rich (> 6 wt % H2O. A pressure of 20 kbar is infered from mineral barometry for the Batur magma chamber. Magmatic chamber model is one in which crystals and melt separate from a convecting Batur magma by density differences, resulting in a stratified magma chamber with a homogeneous central zone, a crystal-rich accumulation zone near the walls or base, and a buoyant, melt-rich zone near the top. This is consistent with the estimated magma temperatures and densities: the pre-eruptive BI-1 magma was hoter (1300oC and more volatile rich (6 wt % H2O with density 2.25 g/cm3 than the BI-2 magma (1200oC; 4 wt % H2O in density was higher (2.50 g/cm3. Batur melt characteristics and intensive parameters are consistent with a volatile oversaturation-driven eruption. However, the higher H2O content, high viscosity and low crystal content of the BI-1 magma imply an external eruption trigger.

  3. Irradiation of hepatocellular carcinoma: Impact of breathing on motions and variations of volume of the tumor, liver and upper abdominal organs; L'irradiation des carcinomes hepatocellulaires: impact de la respiration sur les mouvements et variations de volume de la tumeur, du foie et des organes intra-abdominaux

    Energy Technology Data Exchange (ETDEWEB)

    Kubas, A.; Mornex, F.; D' Hombres, A.; Lorchel, F.; Chapet, O. [Centre hospitalier Lyon-Sud, Service de Radiotherapie-oncologie Rhone-Alpes, 69 - Pierre-Benite (France); Merle, P. [Hopital de l' Hotel-Dieu, Service d' Hepatogastroenterologie, 69 - Lyon (France)

    2008-12-15

    Purpose: To evaluate the amplitude of motion and the variations of volume of the tumor, the liver and upper abdominal organs induced by breathing during the irradiation of hepatocellular carcinoma (H.C.C.). Material and methods: Two scanners were performed in inhale and in exhale not forced in 20 patients with a H.C.C.. The liver (left/right lobes), the tumor, the duodenum, the two kidneys and the pancreas were delineated on each acquisition. The superposition of the two spirals made it possible to measure the displacements and variations of volume of these structures in the cranio caudal (C.C.), lateral (Lat), and anteroposterior (A.P.) directions. Results:The mean displacement of the tumour in C.C., Lat and A.P. was of 19.7 {+-} 8.3 mm, 4.5 {+-} 2.3 mm, and 8.9 {+-} 6.5 mm. The greatest amplitude of movement was obtained in C.C. for the right and left hepatic lobes (19 {+-} 6.5 mm, 10 {+-} 5.6 mm), the duodenum(12.6 {+-} 6.4 mm), the kidneys right and left (15.5 {+-} 6.1 mm, 16.2 {+-} 10 mm) and the pancreas (13.2 {+-} 6 mm). No significant variation of volume was observed for these organs. Conclusion: The movements of the tumour, the liver and the abdominal organs, induced by breathing are significant. The respiratory gating appears essential in particular with the development of new techniques of irradiation such as the intensity-modulated radiotherapy (I.M.R.T.) or the stereotactic body radiation therapy (S.B.R.T.). (authors)

  4. 被动抬腿试验评价感染性休克患者容量反应性的价值%Passive leg raising predicts volume responsiveness in patients with septic shock

    Institute of Scientific and Technical Information of China (English)

    刘云; 卢院华; 谢剑峰; 邱晓华; 董亮; 杨从山; 刘玲; 杨毅; 邱海波

    2011-01-01

    Objective To evaluate the hemodynamic response to passive leg raising (PLR)indicates fluid responsiveness in patients with septic shock. Methods Twenty patients with septic shock,considered for fluid challenge(FC), were enrolled in the study from June 2009 to May 2010. Hemodynamic changes were determined by pulse-contour derived cardiac index at baseline, before and after PLR, return to baseline for 10 min, before and after fluid challenge (250 ml saline for 10 min). An increase of SV after fluid challenge(FC-△SV)≥10% were defined responders. Results Twenty patients with septic shock were included in the study. PLR and fluid challenge were performed 46 instances, among which 15 instances were defined as response group. SV and pulse pressure induced by PLR(PLR-△SV and PLR-△PP) were increased significantly in response group[(76±19)ml vs. (65±18)ml, (73 ±20) mmHg vs. (62 ±20)mmHg (1 mmHg=0.133 kPa), P<0.05], while in nonresponse group there were no significant change.PLR-△SV and PLR-△PP were correlated with FC-△SV (r=0.51,P=0.001; r=0.45, P=0.006),central venous pressure (CVP) were irrelated with FC-△SV. Area under curve (AUC) for PLR-△SV, PLR△PP and stroke volume variation(SVV) were 0. 846, 0.791 and 0.708. PLR-△SV≥12. 5% predicted fluid responsiveness with sensitivity of 80% and specificity of 93.5%. PLR-△PP ≥9.5% predicted fluid responsiveness with sensitivity of 73.3% and specificity of 83.9%. Conclusions PLR-△SV and PLR-△PP can predict fluid responsiveness in patients with septic shock. PLR-△SV and PLR-△PP have a greater ability in predicting volume responsiveness than CVP and SVV.%目的 探讨被动抬腿试验(PLR)预测感染性休克患者容量反应性的价值.方法 2009年6月至2010年5月,20例感染性休克患者纳入研究.采用脉搏指示连续心输出量持续监测患者在基础状态、PLR前后的血流动力学变化,PLR后稳定10min行补液试验(生理盐水250 ml于10 min内静脉滴注),

  5. Duty factor variation possibility from 1% to 100% with PKU microwave driven Cs-free volume H{sup −} sources

    Energy Technology Data Exchange (ETDEWEB)

    Peng, S. X., E-mail: sxpeng@pku.edu.cn; Zhang, T.; Ren, H. T.; Xu, Y.; Zhang, J. F.; Guo, Z. Y. [State Key Laboratory of Nuclear Physics and Technology and Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing 100871 (China); Zhang, A. L. [University of Chinese Academy of Sciences, Beijing 100049 (China); Chen, J. E. [State Key Laboratory of Nuclear Physics and Technology and Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing 100871 (China); University of Chinese Academy of Sciences, Beijing 100049 (China)

    2016-02-15

    Microwave driven cesium-free volume H{sup −} sources, that have the ability to deliver tens of mA H{sup −} at 35 keV both in CW and 10% duty factor (100 Hz/1 ms), were developed at Peking University (PKU) [S. X. Peng et al., in Proceeding of IPAC 2015, WEPWA027, Richmond, Virginia, USA, 3–8 May 2015]. Recently, special efforts were paid on the investigation of duty factor variation possibility from 1% to 100% with them. Most of the experiments were carried out with a pulsed length (τ) of 1 ms and different intervals of 99 ms, 49 ms, 39 ms, 29 ms, 19 ms, 9 ms, 4 ms, 2 ms, 1 ms, 0.5 ms, and 0 ms, respectively. Other experiments were focused on CW operation and fixed duty factor of 1%. Experimental results prove that PKU H{sup −} sources can deliver tens of mA H{sup −} at duty factor from 1% to 100%. The RF power efficiency increases steadily with the increasing of duty factor from 1% to CW at a fixed pulsed length. Under a given duty factor and pulsed length, RF power efficiency keeps constant and the H{sup −} current increases with RF power linearly. Details will be presented in the paper.

  6. Grey matter volume and resting-state functional connectivity of the motor cortex-cerebellum network reflect the individual variation in masticatory performance in the healthy elderly people

    Directory of Open Access Journals (Sweden)

    Chia-Shu eLin

    2016-01-01

    Full Text Available Neuroimaging studies have consistently identified brain activation in the motor area and the cerebellum during chewing. In this study, we further investigated the structural and functional brain signature associated with masticatory performance, which is a widely used index for evaluating overall masticatory function in the elderly. Twenty-five healthy elderly participants underwent oral examinations, masticatory performance tests, and behavioral assessments, including the Cognitive Abilities Screening Instrument and the short-form Geriatric Depression Scale. Masticatory performance was assessed with the validated colorimetric method, using color-changeable chewing gum. T1-weighted structural magnetic resonance imaging (MRI and resting-state function MRI were performed. We analyzed alterations in grey matter volume (GMV using voxel-based morphometry and resting-state functional connectivity (rsFC between brain regions using the seed-based method. The structural and functional MRI analyses revealed the following findings: (1 the GMV change in the premotor cortex was positively correlated with masticatory performance. (2 The rsFC between the cerebellum and the premotor cortex was positively correlated with masticatory performance. (3 The GMV changes in the dorsolateral prefrontal cortex (DLPFC, as well as the rsFC between the cerebellum and the DLPFC, was positively correlated with masticatory performance. The findings showed that in the premotor cortex, a reduction of GMV and rsFC would reflect declined masticatory performance. The positive correlation between DLPFC connectivity and masticatory performance implies that masticatory ability is associated with cognitive function in the elderly. Our findings highlighted the role of the central nervous system in masticatory performance and increased our understanding of the structural and functional brain signature underlying individual variations in masticatory performance in the elderly.

  7. Mechanical behaviors of the dispersion nuclear fuel plates induced by fuel particle swelling and thermal effect I: Effects of variations of the fuel particle volume fractions

    Science.gov (United States)

    Wang, Qiming; Yan, Xiaoqing; Ding, Shurong; Huo, Yongzhong

    2010-05-01

    A new method of modeling the in-pile mechanical behaviors of dispersion nuclear fuel elements is proposed. Considering the irradiation swelling together with the thermal effect, numerical simulations of the in-pile mechanical behaviors are performed with the developed finite element models for different fuel particle volume fractions of the fuel meat. The effects of the particle volume fractions on the mechanical performances of the fuel element are studied. The research results indicate that: (1) the maximum Mises stresses and equivalent plastic strains at the matrix increase with the particle volume fractions at each burnup; the locations of the maximum first principal stresses shift with increasing burnup; at low burnups, the maximum first principal stresses increase with the particle volume fractions; while at high burnups, the 20% volume fraction case holds the lowest value; (2) at the cladding, the maximum equivalent plastic strains and the tensile principal stresses increase with the particle volume fractions; while the maximum Mises stresses do not follow this order at high burnups; (3) the maximum Mises stresses at the fuel particles increase with the particle volume fractions, and the particles will engender plastic strains until the particle volume fraction reaches high enough.

  8. Dynamic preload indicators fail to predict fluid responsiveness in open-chest conditions

    NARCIS (Netherlands)

    de Waal, Eric E. C.; Rex, Steffen; Kruitwagen, Cas L. J. J.; Kalkman, Cor J.; Buhre, Wolfgang F.

    2009-01-01

    Objective: Dynamic preload indicators like pulse pressure variation (PPV) and stroke volume variation (SVV) are increasingly being used for optimizing cardiac preload since they have been demonstrated to predict fluid responsiveness in a variety of perioperative settings. However, in open-chest cond

  9. Diurnal and seasonal variations of NO, NO2 and PM2.5 mass as a function of traffic volumes alongside an urban arterial

    Science.gov (United States)

    Kendrick, Christine M.; Koonce, Peter; George, Linda A.

    2015-12-01

    Urban arterial corridors are landscapes that give rise to short and long-term exposures to transportation-related pollution. With high traffic volumes and a wide mix of road users, urban arterial environments are important targets for improved exposure assessment to traffic-related pollution. A common method to estimate exposure is to use traffic volumes as a proxy. The study presented here analyzes a unique yearlong dataset of simultaneous roadside air quality and traffic observations for a U.S. arterial to assess the reliability of using traffic volumes as a proxy for traffic-related exposure. Results show how the relationships of traffic volumes with NO and NO2 vary not only by time of day and season but also by time aggregation. At short-term aggregations (15 min) nitrogen oxides were found to have a significant linear relationship with traffic volumes during morning hours for all seasons although variability was still high (r2 = 0.1-0.45 NO, r2 = 0.14-0.27 NO2), and little to no relationship during evening periods (r2 traffic volumes to estimate annual exposure concentrations for morning periods (r2 = 0.89 NO, r2 = 0.87 NO2) and evening NO2 (r2 = 0.46). Traffic volumes are a weak or poor predictor for annual evening NO (r2 = -0.09) and short-term 15 min aggregations. Seasonal and diurnal characterizations show that roadside PM2.5 (mass) measurements do not have a relationship with local traffic volumes, leading us to conclude that PM2.5 mass is more tied to regional sources and meteorological conditions. As epidemiology and personal exposure assessment research aims to study health impacts and pollutant levels encountered by pedestrians, bicyclists, those waiting for transit, and other road users, these results show when traffic volumes alone can be a reliable proxy for exposure and when this approach is not warranted.

  10. Avaliação cronológica da variação no volume globular sanguíneo de bovinos leiteiros Cronological evaluation of variation in packed cell volume on dairy cattle

    Directory of Open Access Journals (Sweden)

    Wilmar Sachetin Marçal

    1995-01-01

    Full Text Available Os autores avaliaram a variação no volume globular sangüíneo de 321 bovinos da raça Holandês preta e branca, sadios e criados em granjas leiteiras no Estado de São Paulo. Todos os animais trabalhados na presente pesquisa eram sadios, não reagentes ao vírus da Leucose Bovina, livres de hemoparasitas, brucelose e tuberculose. O volume globular sangüíneo foi efetuado através do método do hematócrito com tubos capilares. Os resultados mostram haver influência da idade sobre o volume globular sangüíneo, com valores médios encontrados de 30,12 ± 2,72%.The packet cell volume was evaluated by the authors in 321 healthy female Holstein cattle raised at Campinas dairy region. São Paulo State. All the animais used in this assay were healthy and free of Leucosis, Tuberculosis, Brucellosis and blood parasites. The packed cell volume has been studied by method of hematocrit with capilary tubos. The results showed an influence of age on packed cell volume with average reference values of 30.12 ± 2.72%.

  11. 每搏输出量变异度在脓毒症休克液体复苏治疗中的指导作用%Value of Stroke Volume Variation in Guiding Resuscitation of Septic Shock

    Institute of Scientific and Technical Information of China (English)

    李权; 陈琦; 郭俊; 李鲲; 王夜明

    2012-01-01

    Objective: To review the recent research on the application of stroke volume variation in re-suscitation of septic shock. Methods: The characteristics, mechanism, advances, application, limitations, etc. , were reviewed in this paper about stroke volume variation. Results: Early fluid resuscitation is an important procedure in anti-septic shock therapy, while during this process, hemodynamics and blood volume changes should be monitored. As an effective and real-time technique, stroke volume variation is a superior indicator to central venous pressure (CVP) in reflecting the changes of circulation during resuscitation. Conclusion; Stroke volume variation has better guiding value and application prospect in the early fluid resuscitation in septic shock therapy%目的:探讨每搏输出量变异度在脓毒症休克液体复苏治疗中的指导作用.方法:对每搏输出量变异度的特点、机理、研究进展、应用范围、局限性等方面进行综述.结果:早期液体复苏在脓毒症休克治疗中占据重要的地位,可维持最佳前负荷,改善容量管理,防止由于低血容量导致的低灌注和过度复苏,可能进一步防止发生多器官功能障碍.因而治疗中监测血流动力学和容量的变化极为重要.脉搏波指示连续心排血量技术是新近出现的一种简便、有效的临床实时监测手段,测定每搏输出量变异度比传统的测定中心静脉压更准确地指导快速液体复苏.结论:每搏输出量变异对预测脓毒症体克早期液体复苏的效果具有良好的指导意义和应用前景.

  12. Renormalized Volume

    Science.gov (United States)

    Gover, A. Rod; Waldron, Andrew

    2017-09-01

    We develop a universal distributional calculus for regulated volumes of metrics that are suitably singular along hypersurfaces. When the hypersurface is a conformal infinity we give simple integrated distribution expressions for the divergences and anomaly of the regulated volume functional valid for any choice of regulator. For closed hypersurfaces or conformally compact geometries, methods from a previously developed boundary calculus for conformally compact manifolds can be applied to give explicit holographic formulæ for the divergences and anomaly expressed as hypersurface integrals over local quantities (the method also extends to non-closed hypersurfaces). The resulting anomaly does not depend on any particular choice of regulator, while the regulator dependence of the divergences is precisely captured by these formulæ. Conformal hypersurface invariants can be studied by demanding that the singular metric obey, smoothly and formally to a suitable order, a Yamabe type problem with boundary data along the conformal infinity. We prove that the volume anomaly for these singular Yamabe solutions is a conformally invariant integral of a local Q-curvature that generalizes the Branson Q-curvature by including data of the embedding. In each dimension this canonically defines a higher dimensional generalization of the Willmore energy/rigid string action. Recently, Graham proved that the first variation of the volume anomaly recovers the density obstructing smooth solutions to this singular Yamabe problem; we give a new proof of this result employing our boundary calculus. Physical applications of our results include studies of quantum corrections to entanglement entropies.

  13. Unsteady Unidirectional Flow of Voigt Fluid through the Parallel Microgap Plates with Wall Slip and Given Inlet Volume Flow Rate Variations

    OpenAIRE

    Yinwei Lin; Chen, C. K.

    2015-01-01

    In order to solve the velocity profile and pressure gradient of the unsteady unidirectional slip flow of Voigt fluid, Laplace transform method is adopted in this research. Between the parallel microgap plates, the flow motion is induced by a prescribed arbitrary inlet volume flow rate which varies with time. The velocity slip condition on the wall and the flow conditions are known. In this paper, two basic flow situations are solved, which are a suddenly started and a constant acc...

  14. CO2气腹对每搏变异度和脉搏灌注变异指数的影响%The effect of carbon dioxide pneumoperitoneum on stroke volume variation and plethysmographic variability index

    Institute of Scientific and Technical Information of China (English)

    刘芳芳; 刘健; 高炟鹏; 嵇晴; 李伟彦

    2013-01-01

    目的 观察气腹对腹腔镜胆囊切除术(LC)患者每搏变异度(SVV)和脉搏灌注变异指数(PVI)的影响及两者相关性干扰.方法 择期全麻下行腹腔镜胆囊切除术患者40例,常规麻醉诱导后气管插管,控制呼吸,潮气量10 ml/kg,呼吸频率8~12次/分.血流动力学平稳后5 min(气腹前)及CO2人工气腹压力12 cm H2O无任何刺激5 min后(气腹后)采用FloTrac/Vigileo系统测量SW,同步采用Masimo Radical 7脉搏血氧仪测量PVI.结果 与气腹前比较,气腹后患者SVV、PVI明显升高(P<0.05).相关性分析显示:气腹前SVV与PVI、气腹后SVV与PVI均呈中等正相关(分别为r=0.556,P<0.01和r=0.415,P<0.01).结论 气腹后SVV、PVI均明显升高,且与气腹前有明显的线性回归关系,但气腹不影响PVI与SVV的良好相关性.

  15. Comparison of arterial pressure and plethysmographic waveform-based dynamic preload variables in assessing fluid responsiveness and dynamic arterial tone in patients undergoing major hepatic resection

    NARCIS (Netherlands)

    Vos, J. J.; Kalmar, A. F.; Struys, M. M. R. F.; Wietasch, J. K. G.; Hendriks, H. G. D.; Scheeren, T. W. L.

    2013-01-01

    Dynamic preload variables to predict fluid responsiveness are based either on the arterial pressure waveform (APW) or on the plethysmographic waveform (PW). We compared the ability of APW-based variations in stroke volume (SVV) and pulse pressure (PPV) and of PW-based plethysmographic variability in

  16. Comparison of arterial pressure and plethysmographic waveform-based dynamic preload variables in assessing fluid responsiveness and dynamic arterial tone in patients undergoing major hepatic resection

    NARCIS (Netherlands)

    Vos, J. J.; Kalmar, A. F.; Struys, M. M. R. F.; Wietasch, J. K. G.; Hendriks, H. G. D.; Scheeren, T. W. L.

    Dynamic preload variables to predict fluid responsiveness are based either on the arterial pressure waveform (APW) or on the plethysmographic waveform (PW). We compared the ability of APW-based variations in stroke volume (SVV) and pulse pressure (PPV) and of PW-based plethysmographic variability

  17. Comparison of arterial pressure and plethysmographic waveform-based dynamic preload variables in assessing fluid responsiveness and dynamic arterial tone in patients undergoing major hepatic resection

    NARCIS (Netherlands)

    Vos, J. J.; Kalmar, A. F.; Struys, M. M. R. F.; Wietasch, J. K. G.; Hendriks, H. G. D.; Scheeren, T. W. L.

    2013-01-01

    Dynamic preload variables to predict fluid responsiveness are based either on the arterial pressure waveform (APW) or on the plethysmographic waveform (PW). We compared the ability of APW-based variations in stroke volume (SVV) and pulse pressure (PPV) and of PW-based plethysmographic variability in

  18. 高容量血液滤过对早期感染性休克猪复苏液体量和血管活性药物用量的影响%The effect of high volume hemofiltration on fluid resuscitation and the dosage of vascular active drug in early septic shock pigs

    Institute of Scientific and Technical Information of China (English)

    张敏; 赵平; 薛露; 吴晓燕; 郑瑞强

    2014-01-01

    Objective To explore the high volume hemofiltration (HVHF ) on fluid resuscitation and the dosage of vascular active drug in early septic shock .Mtehods Eighteen healthy pigs were injected endotoxin 50μg/kg via central vein within 30 minutes.After model establishment, all pigs were randomly divided into three groups ( n =6): control group, normal volume hemofiltration ( NVHF) group and high volume hemofiltration ( HVHF ) group.All the three groups were given mechanical ventilation.Lactic acid salinger liquid for fluid resuscitation was provided after septic shock model establishment, with stroke volume variation ( SVV) less than 10%as an index of liquid recovery termination;SVV would be kept lower than 10% by using intravenous infusion lactic acid salinger liquid.Continuous intravenous infusion of norepinephrine was used to maintain MAP on the basis of the value of more than 90%.Hemodynamic indexes were recorded before infusion endotoxin, 0 h after shock model establishment and 1, 2, 3, 4, 5, 6 h after they were given hemofiltration treatment;the quantity of fluid resuscitation and the dose of norepinephrine during the treatment were tracked.Results Compared with control group, after 1 hour's hemofiltration treatment, the quantity of lactic acid salinger liquid in HVHF group was significantly lower (P<0.05).The NVHF group in 1, 3, 4 hours, the quantity of lactic acid salinger liquid to maintain SVV<10%, was significantly decreased than that of the control group (P<0.05).After 2 hours'hemofiltration treatment, the dosage of lactic acid salinger liquid in HVHF group was significantly lower than NVHF group ( P <0.05 ).After 4 hours hemofiltration treatment, the dose of norepinephrine to sustain the MAP in HVHF group was obviously lower than those in NVHF group and control group, while NVHF group compared with control group has no significant statistical difference.Conclusion The application of HVHF in early septic shock can significantly reduce the quantity of fluid

  19. Convergent evidence of the contribution of TP53 genetic variation (Pro72Arg) to metabolic activity and white matter volume in the frontal lobe in schizophrenia patients.

    Science.gov (United States)

    Molina, Vicente; Papiol, Sergi; Sanz, Javier; Rosa, Araceli; Arias, Bárbara; Fatjó-Vilas, Mar; Calama, Julia; Hernández, Ana I; Bécker, Joemir; Fañanás, Lourdes

    2011-05-01

    Abnormalities in white matter (WM) volumes and integrity in schizophrenia, together with post-mortem studies showing reduced expression of oligodendrocyte/myelination genes and apoptotic processes taking place in oligodendrocytes, suggest the interest of major regulators of apoptosis as candidate genes for some features related to myelin integrity in schizophrenia. Protein p53, encoded by TP53 gene, has a central role in the control of apoptosis and is involved in oligodendrocyte development. TP53 gene polymorphisms may account for variability in WM features, metabolic activity and biochemical markers of neuronal integrity and membrane turnover. Pro72Arg and Ins16bp polymorphisms at TP53 gene were analyzed in 20 DSM-IV schizophrenia patients. T1/T2-weighted sequences of these patients were acquired using a 1.5T Philips Gyroscan system. Scans were transformed into Talairach space and segmented into gray matter (GM), WM and cerebrospinal fluid (CSF) using Statistical Parametric Mapping under a ROI approach. Likewise dorsolateral prefrontal cortex (DLPFC) metabolic activity was measured using a procedure based on MRI/PET image fusion. In 13 of these patients proton magnetic resonance spectroscopy was used to examine N-acetylaspartate (NAA), creatine (Cr) and choline (Cho) levels in dorsolateral-medial prefrontal cortex (DLMPFC). MRI data were adjusted for age and brain volume using regression parameters from a healthy control group (n=45). Patients Pro/Arg heterozygous (Pro72Arg polymorphism) showed a generalized deficit in whole-brain WM that was especially prominent in frontal lobe and a lower metabolic activity in the DLPFC as compared to Pro/Pro homozygous. Pro/Arg subjects also showed decreased NAA/Cho and increased Cho/Cr ratios in right DLMPFC. TP53 genetic variability influences WM volumes in frontal lobes and it seems to modulate the metabolic activity in this region. Our results suggest that TP53 might influence aspects of myelin and white matter integrity

  20. Direct gravimetric measurements of the mass of the antarctic aerosol collected by high volume sampler: PM10 summer seasonal variation at Terra Nova Bay.

    Science.gov (United States)

    Truzzi, Cristina; Lambertucci, Luca; Illuminati, Silvia; Annibaldi, Anna; Scarponi, Giuseppe

    2005-01-01

    An on-site procedure was set up for direct gravimetric measurement of the mass of aerosol collected using high volume impactors (aerodynamic size cut point of 10 microm, PM10); this knowledge has hitherto been unavailable. Using a computerized microbalance in a clean chemistry laboratory, under controlled temperature (+/-0.5 degrees C) and relative humidity (+/-1%), continuous, long time filter mass measurements (hours) were carried out before and after exposure, after a 48 h minimun equilibration at the laboratory conditions. The effect of the electrostatic charge was exhausted in 30-60 min, after which stable measurements were obtained. Measurements of filters exposed for 7-11 days (1.13 m3 min(-1)) in a coastal site near Terra Nova Bay (December 2000 - February 2001), gave results for aerosol mass in the order of 10-20 mg (SD approximately 2 mg), corresponding to atmospheric concentrations of 0.52-1.27 microg m(-3). Data show a seasonal behaviour in the PM10 content with an increase during December - early January, followed by a net decrease. The above results compare well with estimates obtained from proxy data for the Antarctic Peninsula (0.30 microg m(-3)), the Ronne Ice Shelf (1.49 microg m(-3)), and the South Pole (0.18 microg m(-3), summer 1974-1975, and 0.37 microg m(-3), average summer seasons 1975-1976 and 1977-1978), and from direct gravimetric measurements recently obtained from medium volume samplers at McMurdo station (downwind 3.39 microg m(-3), upwind 4.15 microg m(-3)) and at King George Island (2.5 microg m(-3), summer, particle diameter <20 microm). This finding opens the way to the direct measurement of the chemical composition of the Antarctic aerosol and, in turn, to a better knowledge of the snow/air relationships as required for the reconstruction of the chemical composition of past atmospheres from deep ice core data.

  1. Renormalized Volume

    CERN Document Server

    Gover, A Rod

    2016-01-01

    For any conformally compact manifold with hypersurface boundary we define a canonical renormalized volume functional and compute an explicit, holographic formula for the corresponding anomaly. For the special case of asymptotically Einstein manifolds, our method recovers the known results. The anomaly does not depend on any particular choice of regulator, but the coefficients of divergences do. We give explicit formulae for these divergences valid for any choice of regulating hypersurface; these should be relevant to recent studies of quantum corrections to entanglement entropies. The anomaly is expressed as a conformally invariant integral of a local Q-curvature that generalizes the Branson Q-curvature by including data of the embedding. In each dimension this canonically defines a higher dimensional generalization of the Willmore energy/rigid string action. We show that the variation of these energy functionals is exactly the obstruction to solving a singular Yamabe type problem with boundary data along the...

  2. The added value of cardiac index and pulse pressure variation monitoring to mean arterial pressure-guided volume therapy in moderate-risk abdominal surgery (COGUIDE): a pragmatic multicentre randomised controlled trial.

    Science.gov (United States)

    Stens, J; Hering, J-P; van der Hoeven, C W P; Boom, A; Traast, H S; Garmers, L E; Loer, S A; Boer, C

    2017-09-01

    There is disagreement regarding the benefits of goal-directed therapy in moderate-risk abdominal surgery. Therefore, we tested the hypothesis that the addition of non-invasive cardiac index and pulse pressure variation monitoring to mean arterial pressure-based goal-directed therapy would reduce the incidence of postoperative complications in patients having moderate-risk abdominal surgery. In this pragmatic multicentre randomised controlled trial, we randomly allocated 244 patients by envelope drawing in a 1:1 fashion, stratified per centre. All patients had mean arterial pressure, cardiac index and pulse pressure variation measured continuously. In one group, healthcare professionals were blinded to cardiac index and pulse pressure variation values and were asked to guide haemodynamic therapy only based on mean arterial pressure (control group). In the second group, cardiac index and pulse pressure variation values were displayed and kept within target ranges following a pre-defined algorithm (CI-PPV group). The primary endpoint was the incidence of postoperative complications within 30 days. One hundred and seventy-five patients were eligible for final analysis. Overall complication rates were similar (42/94 (44.7%) vs. 38/81 (46.9%) in the control and CI-PPV groups, respectively; p = 0.95). The CI-PPV group had lower mean (SD) pulse pressure variation values (9.5 (2.0)% vs. 11.9 (4.6)%; p = 0.003) and higher mean (SD) cardiac indices (2.76 (0.62) l min(-1) .m(-2) vs. 2.53 (0.66) l min(-1) .m(-2) ; p = 0.004) than the control group. In moderate-risk abdominal surgery, we observed no additional value of cardiac index and pulse pressure variation-guided haemodynamic therapy to mean arterial pressure-guided volume therapy with regard to postoperative complications. © 2017 The Association of Anaesthetists of Great Britain and Ireland.

  3. Protein Thermostability Is Owing to Their Preferences to Non-Polar Smaller Volume Amino Acids, Variations in Residual Physico-Chemical Properties and More Salt-Bridges.

    Directory of Open Access Journals (Sweden)

    Anindya Sundar Panja

    Full Text Available Protein thermostability is an important field for its evolutionary perspective of mesophilic versus thermophilic relationship and for its industrial/ therapeutic applications.Presently, a total 400 (200 thermophilic and 200 mesophilic homologue proteins were studied utilizing several software/databases to evaluate their amino acid preferences. Randomly selected 50 homologous proteins with available PDB-structure of each group were explored for the understanding of the protein charges, isoelectric-points, hydrophilicity, hydrophobicity, tyrosine phosphorylation and salt-bridge occurrences. These 100 proteins were further probed to generate Ramachandran plot/data for the gross secondary structure prediction in and comparison between the thermophilic and mesophilic proteins.Present results strongly suggest that nonpolar smaller volume amino acids Ala (χ2 = 238.54, p<0.001 and Gly (χ2 = 73.35, p<0.001 are highly and Val moderately (χ2 = 144.43, p<0.001 occurring in the 85% of thermophilic proteins. Phospho-regulated Tyr and redox-sensitive Cys are also moderately distributed (χ2~20.0, p<0.01 in a larger number of thermophilic proteins. A consistent lower distribution of thermophilicity and discretely higher distribution of hydrophobicity is noticed in a large number of thermophilic versus their mesophilic protein homolog. The mean differences of isoelectric points and charges are found to be significantly less (7.11 vs. 6.39, p<0.05 and 1 vs. -0.6, p<0.01, respectively in thermophilic proteins compared to their mesophilic counterpart. The possible sites for Tyr phosphorylation are noticed to be 25% higher (p<0.05 in thermophilic proteins. The 60% thermophiles are found with higher number of salt bridges in this study. The average percentage of salt-bridge of thermophiles is found to be higher by 20% than their mesophilic homologue. The GLU-HIS and GLU-LYS salt-bridge dyads are calculated to be significantly higher (p<0.05 and p<0

  4. Volume Entropy

    CERN Document Server

    Astuti, Valerio; Rovelli, Carlo

    2016-01-01

    Building on a technical result by Brunnemann and Rideout on the spectrum of the Volume operator in Loop Quantum Gravity, we show that the dimension of the space of the quadrivalent states --with finite-volume individual nodes-- describing a region with total volume smaller than $V$, has \\emph{finite} dimension, bounded by $V \\log V$. This allows us to introduce the notion of "volume entropy": the von Neumann entropy associated to the measurement of volume.

  5. Variation and Linguistic Theory.

    Science.gov (United States)

    Bailey, Charles-James N.

    This volume presents principles and models for describing language variation, and introduces a time-based, dynamic framework for linguistic description. The book first summarizes some of the problems of grammatical description encountered from Saussure through the present and then outlines possibilities for new descriptions of language which take…

  6. Effects of Goal-directed Volume Therapy on the Intracranial Pressure and the Balance of Cerebral Oxygen Consumption and Supply in Selective Neurosurgery%目标导向液体治疗在择期神经外科手术中对颅内压和脑氧供需平衡的影响

    Institute of Scientific and Technical Information of China (English)

    田胜兰; 周游; 冯丹

    2015-01-01

    Objective To investigate the effects of goal‐directed volume therapy (GDVT )on the intracranial pressure(ICP) and the balance of cerebral oxygen consumption and supply in selective neurosurgery. Methods Twenty‐four patients sched‐uled for intracranial tumor resection were randomly divided into 2 groups:conventional fluid management group (group C ,n=12) and GDVT group(group G ,n=12). Patients in group C received introperative fluid transfusion according to classical fluid management strategies while those in group G received GDT according to stroke volume variation (SVV) ,guided by Flotrac‐Vigileo system.Mean arterial pressure(MAP) ,heart rate(HR) ,cardiac index(CI) ,ICP ,SVV and jugular bulb oxygen saturation (SjvO2 )were recorded before the anesthesia induction(T1 ) ,at the moment of intubation(T2 ) ,at the moment of opening the hard meninges(T3),1hafteropeningthehardmeninges(T4),andattheendofthesurgery(T5).Thecerebraloxygenextractionra‐tio(CERO2 )was calculated. The duration of surgery ,crystalloid volume ,colloid volume ,blood transfusion volume ,urinary output and bleeding volume were recorded as well.Results The colloid transfusion volume ,the total fluid transfusion volume and uri‐nary output were significantly increased in group G when compared with those in group C (P0.05).Conclusion Goal‐directed fluid therapy optimizes the cardiac preload without increasing the ICP in selective neurosurgery ,and it also improves the balance of cerebral oxygen con‐sumption and supply.%目的:观察目标导向液体治疗在择期神经外科手术中对颅内压和脑氧供需平衡的影响。方法选择择期全麻下行开颅肿瘤切除术的患者24例,随机分为2组:常规输液组(C组,n=12)和目标导向液体治疗组(G组,n=12)。C组按经典输液方案进行术中液体管理;G组在Flortrac/Vigileo系统监测下,以每搏量变异度(SVV)为导向行液体治疗。分别于麻醉诱导前(T1

  7. Small-Volume Injections: Evaluation of Volume Administration Deviation From Intended Injection Volumes.

    Science.gov (United States)

    Muffly, Matthew K; Chen, Michael I; Claure, Rebecca E; Drover, David R; Efron, Bradley; Fitch, William L; Hammer, Gregory B

    2017-10-01

    regression model. Analysis of variance was used to determine whether the absolute log proportional error differed by the intended injection volume. Interindividual and intraindividual deviation from the intended injection volume was also characterized. As the intended injection volumes decreased, the absolute log proportional injection volume error increased (analysis of variance, P injection volumes between physicians and pediatric PACU nurses; however, the difference in absolute bias was significantly higher for nurses with a 2-sided significance of P = .03. Clinically significant dose variation occurs when injecting volumes ≤0.5 mL. Administering small volumes of medications may result in unintended medication administration errors.

  8. Experiencing variation

    DEFF Research Database (Denmark)

    Kobayashi, Sofie; Berge, Maria; Grout, Brian William Wilson

    2017-01-01

    This study contributes towards a better understanding of learning dynamics in doctoral supervision by analysing how learning opportunities are created in the interaction between supervisors and PhD students, using the notion of experiencing variation as a key to learning. Empirically, we have based...... were discussed, created more complex patterns of variation. Both PhD students and supervisors can learn from this. Understanding of this mechanism that creates learning opportunities can help supervisors develop their competences in supervisory pedagogy....

  9. Variation in radiotherapy target volume definition, dose to organs at risk and clinical target volumes using anatomic (computed tomography) versus combined anatomic and molecular imaging (positron emission tomography/computed tomography): intensity-modulated radiotherapy delivered using a tomotherapy Hi Art machine: final results of the VortigERN study.

    Science.gov (United States)

    Chatterjee, S; Frew, J; Mott, J; McCallum, H; Stevenson, P; Maxwell, R; Wilsdon, J; Kelly, C G

    2012-12-01

    Contrast-enhanced computed tomography (CECT) is the current standard for delineating tumours of the head and neck for radiotherapy. Although metabolic imaging with positron emission tomography (PET) has been used in recent years, the studies were non-confirmatory in establishing its routine role in radiotherapy planning in the modern era. This study explored the difference in gross tumour volume and clinical target volume definitions for the primary and nodal volumes when FDG PET/CT was used as compared with CECT in oropharyngeal cancer cases. Twenty patients with oropharyngeal cancers had a PET/CT scan in the treatment position after consent. Target volumes were defined on CECT scans by a consultant clinical oncologist who was blind to the PET scans. After obtaining inputs from a radiologist, another set of target volumes were outlined on the PET/CT data set. The gross and clinical target volumes as defined on the two data sets were then analysed. The hypothesis of more accurate target delineation, preventing geographical miss and comparative overlap volumes between CECT and PET/CT, was explored. The study also analysed the volumes of intersection and analysed whether there was any TNM stage migration when PET/CT was used as compared with CECT for planning. In 17 of 20 patients, the TNM stage was not altered when adding FDG PET information to CT. PET information prevented geographical miss in two patients and identified distant metastases in one case. PET/CT gross tumour volumes were smaller than CECT volumes (mean ± standard deviation: 25.16 cm(3) ± 35.8 versus 36.56 cm(3) ± 44.14; P 0.86) were not statistically different. Similarity and discordance coefficients were calculated and are reported. PET/CT as compared with CECT could provide more clinically relevant information and prevent geographical miss when used for radiotherapy planning for advanced oropharyngeal tumours. Also, PET/CT provided a smaller better-defined target volume when compared with CECT

  10. Modeling Per Capita State Health Expenditure Variat...

    Data.gov (United States)

    U.S. Department of Health & Human Services — Modeling Per Capita State Health Expenditure Variation State-Level Characteristics Matter, published in Volume 3, Issue 4, of the Medicare and Medicaid Research...

  11. Variational principles

    CERN Document Server

    Moiseiwitsch, B L

    2004-01-01

    This graduate-level text's primary objective is to demonstrate the expression of the equations of the various branches of mathematical physics in the succinct and elegant form of variational principles (and thereby illuminate their interrelationship). Its related intentions are to show how variational principles may be employed to determine the discrete eigenvalues for stationary state problems and to illustrate how to find the values of quantities (such as the phase shifts) that arise in the theory of scattering. Chapter-by-chapter treatment consists of analytical dynamics; optics, wave mecha

  12. Modelo para la variación del volumen orogénico andino y acortamientos en el sector 20°-46°S Model for Andean orogenic volume variation and shortening in the 20°-46°S sector

    Directory of Open Access Journals (Sweden)

    F.A. Pose

    2005-12-01

    orogenic volume along the southern Central Andes and northern Patagonian Andes (20°-46°S decreases linearly, from north to south. At 38°S, we have separated two segments with different rates of variation in the Andean volume. The northern sector (20°-38°S shows a steeper linear law than the southern sector. Even though the Andean volume varies together with the decrease from north to south of the subducted oceanic slab age, latitude 38°S coincides with a sudden change related to this late parameter. This observation has led us to propose a linkage between subducted parameters and variation of Andean volume, which contrasts with other hypotheses that assume that climate, is the principal cause for the variations in the observed orogenic volume. We also present two empiric equations to calculate the orogenic volume at determined latitude, beyond the area of influence of two anomalies centered around 27°S and 33°S respectively. Those sectors are considered to be influenced by other factors related to isostatic rebounds, superposed to shortening. Additionally, we discuss a law for the latitudinal variation of the orogenic shortening away from the location of the mentioned anomalies.

  13. Unbounded evidence accumulation characterizes subjective visual vertical (SVV) forced-choice perceptual choice and confidence.

    Science.gov (United States)

    Lim, Koeun; Wang, Wei; Merfeld, Daniel M

    2017-07-26

    Humans can subjectively yet quantitatively assess choice confidence based on perceptual precision even when a perceptual decision is made without an immediate reward or feedback. However, surprisingly little is known about choice confidence. Here we investigate the dynamics of choice confidence by merging two parallel conceptual frameworks of decision-making, signal detection theory and sequential analyses (i.e., drift diffusion modeling). Specifically, in order to capture end-point statistics of binary choice and confidence, we built on a previous study that defined choice confidence in terms of psychophysics derived from signal detection theory. At the same time, we augmented this mathematical model to include accumulator dynamics of a drift-diffusion model to characterize the time-dependency of the choice behaviors in a standard forced-choice paradigm in which stimulus duration is controlled by the operator. Human subjects performed a subjective visual vertical task, simultaneously reporting binary orientation choice and probabilistic confidence. Both binary choice and confidence experimental data displayed statistics and dynamics consistent with both signal detection theory and evidence accumulation, respectively. Specifically, the computational simulations showed that the unbounded evidence accumulator model fits the confidence data better than the classical bounded model, while bounded and unbounded models were indistinguishable for binary choice data. These results suggest that the brain can utilize mechanisms consistent with signal detection theory - especially when judging confidence without time pressure. Copyright © 2017, Journal of Neurophysiology.

  14. [Arterial pressure-based cardiac output monitoring: 1. FloTrac sensor and SVV].

    Science.gov (United States)

    Seo, Katsuhiro

    2009-07-01

    FloTrac is a recently introduced semi-invasive arterial pressure-based cardiac output (APCO) monitoring device. The accuracy of a new device is usually evaluated by Bland-Altman method, which shows graphically the mean value of differences between a new method and the reference method (bias), standard deviation of the differences (precision) and limits of agreement or 2 standard deviations. Critchley et al calculated the percentage errors which are two standard deviations divided by mean cardiac output, and proposed that percentage error should be less than 30% as a reliable new method. Cardiac output was measured by FloTrac (APCO) and pulmonary arterial catheter-based thermodilution method (ICO) during off-pump coronary artery bypass and resection of pheochromocytoma, procedures associated with hemodynamically unstable conditions. As algorithm is renewed in a new version of the device, the accuracy of the device is improved; bias, precision and limits of agreement decreased; correlation coefficient increased, and percentage error was assessed to be around 30%. On the other hand, there was a tendency for increased negative bias as cardiac output increased, implying APCO tends to underestimate ICO in high CO ranges. APCO is less invasive and could rapidly respond to fast changes of hemodynamic state. FloTrac is expected to become a reliable cardiac output monitoring device even under hemodynamically unstable conditions. Further improvement of the algorithm is anticipated.

  15. Genetic Variation in the Catechol-O-Methyl Transferase Val108/158Met Is Linked to the Caudate and Posterior Cingulate Cortex Volume in Healthy Subjects: Voxel-Based Morphometry Analysis of Brain Magnetic Resonance Imaging.

    Directory of Open Access Journals (Sweden)

    Keita Watanabe

    Full Text Available The effect of the catechol-O-methyltransferase (COMT Val158Met polymorphism on brain morphology has been investigated but remains controversial. We hypothesized that a comparison between Val/Val and Val/Met individuals, which may represent the most different combinations concerning the effects of the COMT genotype, may reveal new findings. We investigated the brain morphology using 3-Tesla magnetic resonance imaging in 27 Val/Val and 22 Val/Met individuals. Voxel-based morphometry revealed that the volumes of the bilateral caudate and posterior cingulate cortex were significantly smaller in Val/Val individuals than in Val/Met individuals [right caudate: false discovery rate (FDR-corrected p = 0.048; left caudate: FDR-corrected p = 0.048; and bilateral posterior cingulate cortex: FDR-corrected p = 0.048]. This study demonstrates that interacting functional variants of COMT affect gray matter regional volumes in healthy subjects.

  16. Genetic Variation in the Catechol-O-Methyl Transferase Val108/158Met Is Linked to the Caudate and Posterior Cingulate Cortex Volume in Healthy Subjects: Voxel-Based Morphometry Analysis of Brain Magnetic Resonance Imaging

    Science.gov (United States)

    Watanabe, Keita; Kakeda, Shingo; Yoshimura, Reiji; Ide, Satoru; Hayashi, Kenji; Katsuki, Asuka; Umene-Nakano, Wakako; Watanabe, Rieko; Abe, Osamu; Korogi, Yukunori

    2015-01-01

    The effect of the catechol-O-methyltransferase (COMT) Val158Met polymorphism on brain morphology has been investigated but remains controversial. We hypothesized that a comparison between Val/Val and Val/Met individuals, which may represent the most different combinations concerning the effects of the COMT genotype, may reveal new findings. We investigated the brain morphology using 3-Tesla magnetic resonance imaging in 27 Val/Val and 22 Val/Met individuals. Voxel-based morphometry revealed that the volumes of the bilateral caudate and posterior cingulate cortex were significantly smaller in Val/Val individuals than in Val/Met individuals [right caudate: false discovery rate (FDR)-corrected p = 0.048; left caudate: FDR-corrected p = 0.048; and bilateral posterior cingulate cortex: FDR-corrected p = 0.048]. This study demonstrates that interacting functional variants of COMT affect gray matter regional volumes in healthy subjects. PMID:26566126

  17. Wave energy devices with compressible volumes.

    Science.gov (United States)

    Kurniawan, Adi; Greaves, Deborah; Chaplin, John

    2014-12-08

    We present an analysis of wave energy devices with air-filled compressible submerged volumes, where variability of volume is achieved by means of a horizontal surface free to move up and down relative to the body. An analysis of bodies without power take-off (PTO) systems is first presented to demonstrate the positive effects a compressible volume could have on the body response. Subsequently, two compressible device variations are analysed. In the first variation, the compressible volume is connected to a fixed volume via an air turbine for PTO. In the second variation, a water column separates the compressible volume from another volume, which is fitted with an air turbine open to the atmosphere. Both floating and bottom-fixed, axisymmetric, configurations are considered, and linear analysis is employed throughout. Advantages and disadvantages of each device are examined in detail. Some configurations with displaced volumes less than 2000 m(3) and with constant turbine coefficients are shown to be capable of achieving 80% of the theoretical maximum absorbed power over a wave period range of about 4 s.

  18. Hospital variation in mortality after first acute myocardial infarction in Denmark from 1995 to 2002: lower short-term and 1-year mortality in high-volume and specialized hospitals

    DEFF Research Database (Denmark)

    Rasmussen, Søren; Zwisler, Ann-Dorthe O; Abildstrom, Steen Z

    2005-01-01

    with their first admission for AMI between 1995 and 2002 and surviving the day of admission. Multilevel logistic regression was used to determine the relationships between regional and hospital characteristics and 28-day and 365-day mortality after adjusting for individual characteristics, period, and medical......BACKGROUND: This study used linked data from the National Hospital Registry to determine the factors that contribute to differences between hospitals in all-cause mortality after first acute myocardial infarction (AMI) between 1995 and 2002. METHODS: The study included 64,321 patients...... history. RESULTS: Tertiary cardiac care centers (odds ratio [OR], 0.80; 95% confidence interval [CI], 0.67-0.96) and main regional hospitals (OR, 0.90; 95% CI, 0.80-0.99) had improved 28-day mortality compared with local hospitals. A 2-fold increase in annual total MI volume decreased 28-day mortality (OR...

  19. Hospital variation in mortality after first acute myocardial infarction in Denmark from 1995 to 2002: lower short-term and 1-year mortality in high-volume and specialized hospitals

    DEFF Research Database (Denmark)

    Rasmussen, Søren; Zwisler, Ann-Dorthe O; Abildstrom, Steen Z;

    2005-01-01

    history. RESULTS: Tertiary cardiac care centers (odds ratio [OR], 0.80; 95% confidence interval [CI], 0.67-0.96) and main regional hospitals (OR, 0.90; 95% CI, 0.80-0.99) had improved 28-day mortality compared with local hospitals. A 2-fold increase in annual total MI volume decreased 28-day mortality (OR......BACKGROUND: This study used linked data from the National Hospital Registry to determine the factors that contribute to differences between hospitals in all-cause mortality after first acute myocardial infarction (AMI) between 1995 and 2002. METHODS: The study included 64,321 patients...... with their first admission for AMI between 1995 and 2002 and surviving the day of admission. Multilevel logistic regression was used to determine the relationships between regional and hospital characteristics and 28-day and 365-day mortality after adjusting for individual characteristics, period, and medical...

  20. Inter-Seasonal and Annual Co-Variation of Smallholder Production Portfolios, Volumes and Incomes with Rainfall and Flood Levels in the Amazon Estuary: Implications for Building Livelihood Resilience to Increasing Variability of Hydro-Climatic Regimes

    Science.gov (United States)

    Vogt, N. D.; Fernandes, K.; Pinedo-Vasquez, M.; Brondizio, E. S.; Almeida, O.; Rivero, S.; Rabelo, F. R.; Dou, Y.; Deadman, P.

    2014-12-01

    In this paper we investigate inter-seasonal and annual co-variations of rainfall and flood levels with Caboclo production portfolios, and proportions of it they sell and consume, in the Amazon Estuary from August 2012 to August 2014. Caboclos of the estuary maintain a diverse and flexible land-use portfolio, with a shift in dominant use from agriculture to agroforestry and forestry since WWII (Vogt et al., 2014). The current landscape is configured for acai, shrimp and fish production. In the last decade the frequency of wet seasons with anomalous flood levels and duration has increased primarily from changes in rainfall and discharge from upstream basins. Local rainfall, though with less influence on extreme estuarine flood levels, is reported to be more sporadic and intense in wet season and variable in both wet and dry seasons, for yet unknown reasons. The current production portfolio and its flexibility are felt to build resilience to these increases in hydro-climatic variability and extreme events. What is less understood, for time and costliness of daily measures at household levels, is how variations in flood and rainfall levels affect shifts in the current production portfolio of estuarine Caboclos, and the proportions of it they sell and consume. This is needed to identify what local hydro-climatic thresholds are extreme for current livelihoods, that is, that most adversely affect food security and income levels. It is also needed identify the large-scale forcings driving those extreme conditions to build forecasts for when they will occur. Here we present results of production, rainfall and flood data collected daily in households from both the North and South Channel of the Amazon estuary over last two years to identify how they co-vary, and robustness of current production portfolio under different hydro-climatic conditions.

  1. Mothers depart. Variations 2009

    Directory of Open Access Journals (Sweden)

    Agnieszka Czyżak

    2011-01-01

    Full Text Available This article proposes some considerations on a particular variation of the elegiac mood represented by and manifested in lyrical farewells of departing mothers. A review of the variants commences with an analysis of a particularly important work by Tadeusz Różewicz written at the beginning of this century — Matka odchodzi. The book was, at the time, a particular reference point for the following poetic volumes in which the theme of the death of the poet’s mother was paramount and significant. The article also focuses on volumes of poems, written by poets that belonged to different generations but shared the same date of publication, i.e. the year 2009. Both clear similarities and marked differences in the actual commitment in carrying out the theme and in creating the profiles of mothers that have passed away are to be found in the works of Piotr Sommer (Dni i noce, Jan Polkowski (Cantus and Eugeniusz Tkaczyszyn-Dycki (Piosenka o zależnościach i uzależnieniach.

  2. Effects of carbon dioxide and pH variations in vitro on blood respiratory functions, red blood cell volume, transmembrane pH gradients, and sickling in sickle cell anemia

    Energy Technology Data Exchange (ETDEWEB)

    Ueda, Y.; Bookchin, R.M.

    1984-08-01

    An examination was made of the O/sub 2/ affinity, Bohr effect, transmembrane pH gradient, mean cell hemoglobin concentration, and red blood cell sickling at half O/sub 2/ saturation in whole sickle cell (SS) and normal (AA) blood during CO/sub 2/ titration and acid-base titration at three Pco/sub 2/ levels, 10, 40, and 80 mm Hg. The CO/sub 2/-induced Bohr effect of SS blood was considerably larger than normal (maximum, 0.91, referred to cell pH) and similar to that found with acid-base titration at Pco/sub 2/ of 40. In contrast to AA blood, SS blood showed an increased O/sub 2/ affinity when Pco/sub 2/ was raised from 40 to 80, and at half O/sub 2/ saturation showed biphasic or sigmoid Bohr curves, a fall in transmembrane pH gradient with rising Pco/sub 2/, and an absence of the normal cell volume increase at low pH and Pco/sub 2/. Sickling of SS cells at half O/sub 2/ saturation was partly inhibited by increasing Pc/sub 2/, particularly in the higher pH ranges. These complex differences in the behavior of SS blood are interpreted in terms of the balancing of several effects: the lowering of hemoglobin O/sub 2/-affinity by polymerization, low pH and increased CO/sub 2/ binding, inhibition of hemoglobin S polymerization by CO/sub 2/ binding to ..beta../sup s/-chain amino termini, differences between hemoglobin S and A in competitive binding of CO/sub 2/ and 2,3-diphosphoglycerate at different pH levels, and an increased net negative charge exhibited by intracellular deoxyhemoglobin S polymers. From a clinical standpoint, in the absence of hypoxia or acidosis, an increased blood Pco/sub 2/ might have a beneficial effect by inhibiting red blood cell sickling, whereas a metabolic acidosis, with low blood pH and Pco/sub 2/, would be very hazardous.

  3. Laws of volume and dosimetric variations of parotid gland during intensity-modulated radiation therapy analyzed by CTVision image-guided system in patients with nasopharyngeal carcinoma%CTVision图像引导系统分析调强放疗过程中鼻咽癌患者腮腺的体积及剂量学变化规律

    Institute of Scientific and Technical Information of China (English)

    吴海燕; 徐子海; 周燕华

    2016-01-01

    目的:应用 CTVision 图像引导系统观察鼻咽癌患者行调强放疗时腮腺体积及剂量学的变化规律。方法选取45例行调强放射治疗的鼻咽癌患者,分别于放疗的第1、2、3、4周末应用CTVision系统行CT图像引导扫描,将CT图像上传至放疗计划系统,勾画腮腺,观察其体积的变化规律;将放疗前治疗规划复制到每个CT图像上,计算腮腺的剂量分布,总结其剂量学变化规律。结果双侧腮腺体积均随放疗进程的延长而缩小(P<0.05),放疗结束时,左、右侧腮腺体积较放疗前分别缩小35.16%和32.37%;双侧腮腺照射剂量均随放疗过程的延长而增加(P<0.05),左、右侧腮腺照射剂量较放疗前所设计的照射剂量分别增加7.81%~35.24%、10.26%~46.61%;双侧腮腺所受的剂量增加幅度与腮腺体积缩小幅度呈正相关(P<0.05)。结论鼻咽癌行调强放疗时,腮腺体积随着放疗进程延长向内侧呈进行性缩小,导致腮腺所受的放疗剂量较原放疗计划剂量明显增加。%Objective To observe the laws of volume and dosimetric variations of parotid gland during intensity-modulated radiation therapy by CTVision image-guided system in patients with nasopharyngeal carcinoma.Methods Forty-five patients with nasopharyngeal carcinoma who planned to undergo intensity-modulated radiation therapy were selected.And image-guided CT scan by CTVision system was conducted in the 1st,2nd, 3rd,4th week of radiotherapy respectively.The CT images were transmitted to therapy planning system,then the parotid gland was sketched and the variation law of volume was observed.The therapy planning before radiotherapy was copied to each CT image ,then the dose distribution of parotid gland was calculated and the variation law of dose was summarized.Results The volumes of bilateral parotid glands diminished with the progress of the radiation(P<0.05).Compared

  4. Swept Volume Parameterization for Isogeometric Analysis

    Science.gov (United States)

    Aigner, M.; Heinrich, C.; Jüttler, B.; Pilgerstorfer, E.; Simeon, B.; Vuong, A.-V.

    Isogeometric Analysis uses NURBS representations of the domain for performing numerical simulations. The first part of this paper presents a variational framework for generating NURBS parameterizations of swept volumes. The class of these volumes covers a number of interesting free-form shapes, such as blades of turbines and propellers, ship hulls or wings of airplanes. The second part of the paper reports the results of isogeometric analysis which were obtained with the help of the generated NURBS volume parameterizations. In particular we discuss the influence of the chosen parameterization and the incorporation of boundary conditions.

  5. Formula for Calculating Maintenance Fluid Volumes in Low Birth ...

    African Journals Online (AJOL)

    TNHJOURNALPH

    2007-08-14

    Aug 14, 2007 ... The paired sample T- test, using variation in days and in ... accuracy is validated; having compared .... rapid weight changes would suggest water loss or gain. ..... TABLE 11: Volume In milk [!hr. using the RAW Formula. R.

  6. Partial differential equations and calculus of variations

    CERN Document Server

    Leis, Rolf

    1988-01-01

    This volume contains 18 invited papers by members and guests of the former Sonderforschungsbereich in Bonn (SFB 72) who, over the years, collaborated on the research group "Solution of PDE's and Calculus of Variations". The emphasis is on existence and regularity results, on special equations of mathematical physics and on scattering theory.

  7. Volume 10 No. 11 November 2010 4320 IONOMIC VARIATION ...

    African Journals Online (AJOL)

    user

    2010-11-11

    Nov 11, 2010 ... VEGETABLES FOR MICRONUTRIENTS USING XRF AND HPLC ... Institute of Nuclear Science and Technology, University of Nairobi, P.O. Box ..... system was composed of a Waters 600 dual piston solvent delivery pump ...

  8. Ovarian volume throughout life

    DEFF Research Database (Denmark)

    Kelsey, Thomas W; Dodwell, Sarah K; Wilkinson, A Graham

    2013-01-01

    cancer. To date there is no normative model of ovarian volume throughout life. By searching the published literature for ovarian volume in healthy females, and using our own data from multiple sources (combined n=59,994) we have generated and robustly validated the first model of ovarian volume from...... to about 2.8 mL (95% CI 2.7-2.9 mL) at the menopause and smaller volumes thereafter. Our model allows us to generate normal values and ranges for ovarian volume throughout life. This is the first validated normative model of ovarian volume from conception to old age; it will be of use in the diagnosis...

  9. Mean nuclear volume

    DEFF Research Database (Denmark)

    Mogensen, O.; Sørensen, Flemming Brandt; Bichel, P.

    1999-01-01

    We evaluated the following nine parameters with respect to their prognostic value in females with endometrial cancer: four stereologic parameters [mean nuclear volume (MNV), nuclear volume fraction, nuclear index and mitotic index], the immunohistochemical expression of cancer antigen (CA125...

  10. Calculus of variations

    CERN Document Server

    Elsgolc, L E; Stark, M

    1961-01-01

    Calculus of Variations aims to provide an understanding of the basic notions and standard methods of the calculus of variations, including the direct methods of solution of the variational problems. The wide variety of applications of variational methods to different fields of mechanics and technology has made it essential for engineers to learn the fundamentals of the calculus of variations. The book begins with a discussion of the method of variation in problems with fixed boundaries. Subsequent chapters cover variational problems with movable boundaries and some other problems; sufficiency

  11. 西藏东南部米堆冰湖面积和水量变化及其对溃决灾害发生的影响%Study on the Variations of Lake Area & Volume and Their Effect on the Occurrence of Outburst of Midui Glacier Lake in Southeastern Tibet

    Institute of Scientific and Technical Information of China (English)

    杨瑞敏; 朱立平; 王永杰; 除多

    2012-01-01

    冰湖溃决灾害是青藏高原地区主要的灾害之一。详细了解冰湖的面积和水量变化及其原因,有助于更准确地确定其溃决的可能性和产生破坏的程度和范围。米堆冰湖为一个典型的冰碛物阻塞冰湖,1988年7月15日曾发生溃决。本研究利用1980年1:5万地形图和DEM、1988年TM影像、2001年IKONOS影像以及2001、2007、2009、2010年ALOS影像,提取冰湖溃决前后的面积变化,结合野外实地测得的冰湖水深,获得冰湖不同时期的水量及其变化。同时,利用自动水位计,监测湖泊相对水深的变化及其原因。结果显示,米堆溃决前面积达到64×10^4m^2,水量为699×10^4m^3,溃决使得601.83×10^4m^3的水量溃出,水位下降了17.18m,但溃决口并未达到冰湖最低处,溃决后仍有97.17×10^4m^3的水量。近年来,气温升高融水增加使得冰湖面积和水量不断增加,按照目前的水量增加速率,冰湖再次发生溃决的可能性较小,而在由于其他原因使得冰湖发生堵塞或大量外来物质(冰川断裂、滑坡等)填充进冰湖时,可能导致冰湖水位急剧上升,再次发生溃决。%Glacial lake outburst is one of the main hazards on the Tibetan Plateau. It is very important to understand the detailed information of variations and reasons of glacial lake area & volume for evaluating the possibility of glacial lake outburst and its damage degree. Midui Glacial Lake is a typical moraine-dammed lake, which had an outburst on July 15th in 1988. In this study the authors extract this lake areas in different stages from the topographic map (1:5000) taken in 1980 and TM images in 1988, IKONOS in 2001, ALOS in 2001/2007/2009/ 2010. The lake volumes in different stages are calculated by using the lake areas and the bathymetric survey results. Meanwhile, the authors monitor the relative lake water level changes by using automatic water gauges. Resuits

  12. Functions of bounded variation

    OpenAIRE

    Lind, Martin

    2006-01-01

    The paper begins with a short survey of monotone functions. The functions of bounded variation are introduced and some basic properties of these functions are given. Finally the jump function of a function of bounded variation is defined.

  13. Volume Regulated Channels

    DEFF Research Database (Denmark)

    Klausen, Thomas Kjær

    - serves a multitude of functions in the mammalian cell, regulating the membrane potential (Em), cell volume, protein activity and the driving force for facilitated transporters giving Cl- and Cl- channels a major potential of regulating cellular function. These functions include control of the cell cycle...... of volume perturbations evolution have developed system of channels and transporters to tightly control volume homeostasis. In the past decades evidence has been mounting, that the importance of these volume regulated channels and transporters are not restricted to the defense of cellular volume......, controlled cell death and cellular migration. Volume regulatory mechanisms has long been in focus for regulating cellular proliferation and my thesis work have been focusing on the role of Cl- channels in proliferation with specific emphasis on ICl, swell. Pharmacological blockage of the ubiquitously...

  14. Studying Variation in Tunes

    NARCIS (Netherlands)

    Janssen, B.; van Kranenburg, P.

    2014-01-01

    Variation in music can be caused by different phenomena: conscious, creative manipulation of musical ideas; but also unconscious variation during music recall. It is the latter phenomenon that we wish to study: variation which occurs in oral transmission, in which a melody is taught without the help

  15. Studying Variation in Tunes

    NARCIS (Netherlands)

    Janssen, B.; van Kranenburg, P.

    2014-01-01

    Variation in music can be caused by different phenomena: conscious, creative manipulation of musical ideas; but also unconscious variation during music recall. It is the latter phenomenon that we wish to study: variation which occurs in oral transmission, in which a melody is taught without the help

  16. Precision volume measurement system.

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Erin E.; Shugard, Andrew D.

    2004-11-01

    A new precision volume measurement system based on a Kansas City Plant (KCP) design was built to support the volume measurement needs of the Gas Transfer Systems (GTS) department at Sandia National Labs (SNL) in California. An engineering study was undertaken to verify or refute KCP's claims of 0.5% accuracy. The study assesses the accuracy and precision of the system. The system uses the ideal gas law and precise pressure measurements (of low-pressure helium) in a temperature and computer controlled environment to ratio a known volume to an unknown volume.

  17. Differences in Radiotherapy Delivery and Outcome Due to Contouring Variation

    DEFF Research Database (Denmark)

    Hollensen, Christian; Persson, Gitte; Højgaard, Liselotte;

    2012-01-01

    segmentation methods also produce different results. There is no consensus on how to account for the contouring uncertainty, but has been suggested to incorporate it into the planning target volume (PTV) margin. Current recipes for the PTV margin are based on normal distribution assumptions and are more......Gross tumor volume (GTV) delineation is central for radiotherapy planning. It provides the basis of the clinical target volume and, ultimately, the planning target volume which is used for dose optimization. Manual GTV delineations are prone to intra- and inter-observer variation and automatic...

  18. Virtueel trainen met RescueSim : Onderzoek naar ervaringen en leereffecten in het project Samen Voorbereid Veilig (SVV)

    NARCIS (Netherlands)

    Houtkamp, J.M.

    2014-01-01

    Van 2007 tot 2012 hebben onderzoekers van het GATE (GAme research for Training and Entertainment)-project van de Universiteit Utrecht verscheidene onderzoeksprojecten uitgevoerd met de trainingssoftware RescueSim, ontwikkeld door VSTEP BV en Risk Management Control. Centraal stond de vraag hoe een r

  19. Variable volume combustor

    Energy Technology Data Exchange (ETDEWEB)

    Ostebee, Heath Michael; Ziminsky, Willy Steve; Johnson, Thomas Edward; Keener, Christopher Paul

    2017-01-17

    The present application provides a variable volume combustor for use with a gas turbine engine. The variable volume combustor may include a liner, a number of micro-mixer fuel nozzles positioned within the liner, and a linear actuator so as to maneuver the micro-mixer fuel nozzles axially along the liner.

  20. Volume Regulated Channels

    DEFF Research Database (Denmark)

    Klausen, Thomas Kjær

    of volume perturbations evolution have developed system of channels and transporters to tightly control volume homeostasis. In the past decades evidence has been mounting, that the importance of these volume regulated channels and transporters are not restricted to the defense of cellular volume...... but are also essential for a number of physiological processes such as proliferation, controlled cell death, migration and endocrinology. The thesis have been focusing on two Channels, namely the swelling activated Cl- channel (ICl, swell) and the transient receptor potential Vanilloid (TRPV4) channel. I: Cl......- serves a multitude of functions in the mammalian cell, regulating the membrane potential (Em), cell volume, protein activity and the driving force for facilitated transporters giving Cl- and Cl- channels a major potential of regulating cellular function. These functions include control of the cell cycle...

  1. Hermite variational implicit surface reconstruction

    Institute of Scientific and Technical Information of China (English)

    PAN RongJiang; MENG XiangXu; WHANGBO TaegKeun

    2009-01-01

    We propose a new technique for reconstructing surfaces from a large set of unorganized 3D data points and their associated normal vectors. The surface is represented as the zero level set of an implicit vol-ume model which fits the data points and normal constraints. Compared with variational implicit sur-faces, we make use of surface normal vectors at data points directly in the implicit model and avoid of introducing manufactured off-surface points. Given n surface point/normal pairs, the proposed method only needs to solve an n×n positive definite linear system. It allows fitting large datasets effectively and robustly. We demonstrate the performance of the proposed method with both globally supported and compactly supported radial basis functions on several datasets.

  2. Reduction of residual limb volume in people with transtibial amputation

    Directory of Open Access Journals (Sweden)

    Audrey T. Tantua, MD

    2014-11-01

    Full Text Available The early postoperative phase after transtibial amputation is characterized by rapid residual limb volume reduction. Accurate measurement of residual limb volume is important for the timing of fitting a prosthesis. The aim of this study was to analyze the reduction of residual limb volume in people with transtibial amputation and to correlate residual limb volume with residual limb circumference. In a longitudinal cohort study of 21 people who had a transtibial amputation, residual limb volume was measured using a laser scanner and circumference was measured using a tape measure 1 wk postamputation and every 3 wk thereafter until 24 wk postamputation. A linear mixed model analysis was performed with weeks postamputation transformed according to the natural logarithm as predictor. Residual limb volume decreased significantly over time, with a large variation between patients. Residual limb volume did not correlate well with circumference. On average, residual limb volume decreased 200.5 mL (9.7% of the initial volume per natural logarithm of the weeks postamputation. The decrease in residual limb volume following a transtibial amputation was substantial in the early postamputation phase, followed by a leveling off. It was not possible to determine the specific moment at which the residual limb volume stabilized.

  3. The interdecadal variation of Indonesian Throughflow and its mechanism

    Institute of Scientific and Technical Information of China (English)

    MENG Xiangfeng; WU Dexing; HU Ruijin; LAN Jian

    2004-01-01

    The interdecadal variation of the volume and heat transport of Indonesian Throughflow (ITF) and its mechanism are preliminarily studied on the basis of the updated SODA data. It is found that the interdecadal variation of ITF's volume transport is mainly concentrated in upper 714 m and that of ITF's heat transport is mainly confined to upper 450 m. There is fairly consistent interdecadal variation in the depth-integrated seawater pressure above different depths in the region south of Davao, north of New Guinea and southwest of Australia. The depth-integrated pressure difference between northwest of Australia and south of Java has best correspondence with ITF's volume transport on interdecadal time scales. The relation between the wind stress on the Pacific and ITF's volume transport on interdecadal time scales is studied based on Island Rule. It is shown that both the wind stress along the zonal lines just south of Australia and the Equator act as the dominant contributors to ITF's volume transport, with the latter dominating the phase of ITF's interdecadal variation. These results indicate that the atmospheric forcing and oceanic adjustment in the tropical region both contribute significantly to the ITF's interdecadal variation.

  4. Some variational principles in electroelastic media under finite deformation

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    It is proposed that the universal thermodynamic energy variational principle is in-cluded in the first law of thermodynamics. Some variational principles in the elec-troelastic media under finite deformation are derived from this universal thermo-dynamic variational principle. It is suggested that in the general electroelastic analysis the environment should be considered together with the discussed elec-troelastic medium. For the variational principle of nonlinear electroelastic media the variation of the electric potential is coupled with the virtual displacement,and the variation of the initial volume should be considered. The Maxwell stress in the initial configuration is naturally derived from this variational principle and it is unique in the second order precision.

  5. Some variational principles in electroelastic media under finite deformation

    Institute of Scientific and Technical Information of China (English)

    KUANG ZhenBang

    2008-01-01

    It is proposed that the universal thermodynamic energy variational principle is in-cluded in the first law of thermodynamics. Some variational principles in the elec-troelastic media under finite deformation are derived from this universal thermo-dynamic variational principle. It is suggested that in the general electroelastic analysis the environment should be considered together with the discussed elec-troelastic medium. For the variational principle of nonlinear electroelastic media the variation of the electric potential is coupled with the virtual displacement, and the variation of the initial volume should be considered. The Maxwell stress in the initial configuration is naturally derived from this variational principle and it is unique in the second order precision.

  6. Variation of fundamental constants

    CERN Document Server

    Flambaum, V V

    2006-01-01

    We present a review of recent works devoted to the variation of the fine structure constant alpha, strong interaction and fundamental masses. There are some hints for the variation in quasar absorption spectra, Big Bang nucleosynthesis, and Oklo natural nuclear reactor data. A very promising method to search for the variation of the fundamental constants consists in comparison of different atomic clocks. Huge enhancement of the variation effects happens in transition between accidentally degenerate atomic and molecular energy levels. A new idea is to build a ``nuclear'' clock based on the ultraviolet transition between very low excited state and ground state in Thorium nucleus. This may allow to improve sensitivity to the variation up to 10 orders of magnitude! Huge enhancement of the variation effects is also possible in cold atomic and molecular collisions near Feschbach resonance.

  7. Volume regulation in epithelia

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Hoffmann, Else Kay

    2016-01-01

    function of iso-osmotic fluid transport that depends on Na+ recirculation. The causative relationship is discussed for a fluid-absorbing and a fluid-secreting epithelium of which the Na+ recirculation mechanisms have been identified. A large number of transporters and ion channels involved in cell volume...... regulation are cloned. The volume-regulated anion channel (VRAC) exhibiting specific electrophysiological characteristics seems exclusive to serve cell volume regulation. This is contrary to K+ channels as well as cotransporters and exchange mechanisms that may serve both transepithelial transport and cell...

  8. Towards the Amplituhedron Volume

    CERN Document Server

    Ferro, Livia; Orta, Andrea; Parisi, Matteo

    2015-01-01

    It has been recently conjectured that scattering amplitudes in planar N=4 super Yang-Mills are given by the volume of the (dual) amplituhedron. In this paper we show some interesting connections between the tree-level amplituhedron and a special class of differential equations. In particular we demonstrate how the amplituhedron volume for NMHV amplitudes is determined by these differential equations. The new formulation allows for a straightforward geometric description, without any reference to triangulations. Finally we discuss possible implications for volumes related to generic N^kMHV amplitudes.

  9. Unsteady flow volumes

    Energy Technology Data Exchange (ETDEWEB)

    Becker, B.G.; Lane, D.A.; Max, N.L.

    1995-03-01

    Flow volumes are extended for use in unsteady (time-dependent) flows. The resulting unsteady flow volumes are the 3 dimensional analog of streamlines. There are few examples where methods other than particle tracing have been used to visualize time varying flows. Since particle paths can become convoluted in time there are additional considerations to be made when extending any visualization technique to unsteady flows. We will present some solutions to the problems which occur in subdivision, rendering, and system design. We will apply the unsteady flow volumes to a variety of field types including moving multi-zoned curvilinear grids.

  10. Bronchoscopic lung volume reduction

    Directory of Open Access Journals (Sweden)

    M. I. Polkey

    2006-12-01

    Full Text Available Surgical lung volume reduction can improve exercise performance and forced expiratory volume in one second in patients with emphysema. However, the procedure is associated with a 5% mortality rate and a nonresponse rate of 25%. Accordingly, interest has focused on alternative ways of reducing lung volume. Two principle approaches are used: collapse of the diseased area using blockers placed endobronchially and the creation of extrapulmonary pathways. Preliminary data from the former approach suggest that it can be successful and that the magnitude of success is related to reduction in dynamic hyperinflation.

  11. Calculus of variations

    CERN Document Server

    Gelfand, I M

    2000-01-01

    Based on a series of lectures given by I. M. Gelfand at Moscow State University, this book actually goes considerably beyond the material presented in the lectures. The aim is to give a treatment of the elements of the calculus of variations in a form both easily understandable and sufficiently modern. Considerable attention is devoted to physical applications of variational methods, e.g., canonical equations, variational principles of mechanics, and conservation laws.The reader who merely wishes to become familiar with the most basic concepts and methods of the calculus of variations need on

  12. Free volume under shear

    Science.gov (United States)

    Maiti, Moumita; Vinutha, H. A.; Sastry, Srikanth; Heussinger, Claus

    2015-10-01

    Using an athermal quasistatic simulation protocol, we study the distribution of free volumes in sheared hard-particle packings close to, but below, the random-close packing threshold. We show that under shear, and independent of volume fraction, the free volumes develop features similar to close-packed systems — particles self-organize in a manner as to mimick the isotropically jammed state. We compare athermally sheared packings with thermalized packings and show that thermalization leads to an erasure of these structural features. The temporal evolution in particular the opening-up and the closing of free-volume patches is associated with the single-particle dynamics, showing a crossover from ballistic to diffusive behavior.

  13. Integers annual volume 2013

    CERN Document Server

    Landman, Bruce

    2014-01-01

    ""Integers"" is a refereed online journal devoted to research in the area of combinatorial number theory. It publishes original research articles in combinatorics and number theory. This work presents all papers of the 2013 volume in book form.

  14. Renormalized Volumes with Boundary

    CERN Document Server

    Gover, A Rod

    2016-01-01

    We develop a general regulated volume expansion for the volume of a manifold with boundary whose measure is suitably singular along a separating hypersurface. The expansion is shown to have a regulator independent anomaly term and a renormalized volume term given by the primitive of an associated anomaly operator. These results apply to a wide range of structures. We detail applications in the setting of measures derived from a conformally singular metric. In particular, we show that the anomaly generates invariant (Q-curvature, transgression)-type pairs for hypersurfaces with boundary. For the special case of anomalies coming from the volume enclosed by a minimal hypersurface ending on the boundary of a Poincare--Einstein structure, this result recovers Branson's Q-curvature and corresponding transgression. When the singular metric solves a boundary version of the constant scalar curvature Yamabe problem, the anomaly gives generalized Willmore energy functionals for hypersurfaces with boundary. Our approach ...

  15. Environmental chemistry: Volume A

    Energy Technology Data Exchange (ETDEWEB)

    Yen, T.F.

    1999-08-01

    This is an extensive introduction to environmental chemistry for engineering and chemical professionals. The contents of Volume A include a brief review of basic chemistry prior to coverage of litho, atmo, hydro, pedo, and biospheres.

  16. Entry and Exit Stress Variation of Cold Rolling Strip

    Institute of Scientific and Technical Information of China (English)

    WANGDong—cheng

    2012-01-01

    The shortcomings of an exit stress variation formula which has been well accepted are analyzed~ it is found that the exit stress variation formula violates the premise of the law of volume constancy. The shortcomings of an en- try stress variation formula are analyzed too, and the basic assumption of the formula is uniform exit velocity. How- ever, for a rigid-plastic material uniform exit velocity implies that the lateral distributioi1 of elongation is uniform, so the exit stress must be uniform and any type of flatness defect is impossible, which is contrary to the practice. In fact, entry and exit velocity variation influence entry and exit stress variation, and entry and exit stress variation in- fluence entry and exit velocity variation too, so a precise explicit stress variation formula cannot be got easily. Con- sidering the relationship between stress variation and velocity variation, an iteration method is presented to calculate entry and exit stress variation of cold rolling strip. To avoid divergent phenomenon of the iteration course, a relaxa- tion factor method is adopted. The calculation results are compared with the entry and exit stress variation formula commonly used by many researchers. The difference is remarkable, while the result calculated agree more well with measured result if the exit elastic recovery zone is considered. Specially, the incoming flatnessI propagate efficiency calculated ~ives a more realistic result.

  17. Generalized Partial Volume

    DEFF Research Database (Denmark)

    Darkner, Sune; Sporring, Jon

    2011-01-01

    Mutual Information (MI) and normalized mutual information (NMI) are popular choices as similarity measure for multimodal image registration. Presently, one of two approaches is often used for estimating these measures: The Parzen Window (PW) and the Generalized Partial Volume (GPV). Their theoret......Mutual Information (MI) and normalized mutual information (NMI) are popular choices as similarity measure for multimodal image registration. Presently, one of two approaches is often used for estimating these measures: The Parzen Window (PW) and the Generalized Partial Volume (GPV...

  18. Reachable volume RRT

    KAUST Repository

    McMahon, Troy

    2015-05-01

    © 2015 IEEE. Reachable volumes are a new technique that allows one to efficiently restrict sampling to feasible/reachable regions of the planning space even for high degree of freedom and highly constrained problems. However, they have so far only been applied to graph-based sampling-based planners. In this paper we develop the methodology to apply reachable volumes to tree-based planners such as Rapidly-Exploring Random Trees (RRTs). In particular, we propose a reachable volume RRT called RVRRT that can solve high degree of freedom problems and problems with constraints. To do so, we develop a reachable volume stepping function, a reachable volume expand function, and a distance metric based on these operations. We also present a reachable volume local planner to ensure that local paths satisfy constraints for methods such as PRMs. We show experimentally that RVRRTs can solve constrained problems with as many as 64 degrees of freedom and unconstrained problems with as many as 134 degrees of freedom. RVRRTs can solve problems more efficiently than existing methods, requiring fewer nodes and collision detection calls. We also show that it is capable of solving difficult problems that existing methods cannot.

  19. Ladder Variational Autoencoder

    DEFF Research Database (Denmark)

    Sønderby, Casper Kaae; Raiko, Tapani; Maaløe, Lars

    2016-01-01

    Variational autoencoders are powerful models for unsupervised learning. However deep models with several layers of dependent stochastic variables are difficult to train which limits the improvements obtained using these highly expressive models. We propose a new inference model, the Ladder Variat...

  20. Variation of Fundamental Constants

    Science.gov (United States)

    Flambaum, V. V.

    2006-11-01

    Theories unifying gravity with other interactions suggest temporal and spatial variation of the fundamental ``constants'' in expanding Universe. The spatial variation can explain a fine tuning of the fundamental constants which allows humans (and any life) to appear. We appeared in the area of the Universe where the values of the fundamental constants are consistent with our existence. We present a review of recent works devoted to the variation of the fine structure constant α, strong interaction and fundamental masses. There are some hints for the variation in quasar absorption spectra. Big Bang nucleosynthesis, and Oklo natural nuclear reactor data. A very promising method to search for the variation of the fundamental constants consists in comparison of different atomic clocks. Huge enhancement of the variation effects happens in transition between accidentally degenerate atomic and molecular energy levels. A new idea is to build a ``nuclear'' clock based on the ultraviolet transition between very low excited state and ground state in Thorium nucleus. This may allow to improve sensitivity to the variation up to 10 orders of magnitude! Huge enhancement of the variation effects is also possible in cold atomic and molecular collisions near Feshbach resonance.

  1. Genetic variation in variability

    NARCIS (Netherlands)

    Mulder, Herman; Gienapp, Phillip; Visser, Marcel E.

    2016-01-01

    Variation in traits is essential for natural selection to operate and genetic and environmental effects can contribute to this phenotypic variation. From domesticated populations, we know that families can differ in their level of within-family variance, which leads to the intriguing situation th

  2. Physiology of biological variation

    NARCIS (Netherlands)

    Schouten, R.E.

    2004-01-01

    In agricultural products, variation exists in quality attributes between batches. Examples of this biological variation are well known and the general response is trying to suppress it as much as possible; to create uniformity using pre- andpostharvestmethods. This thesis

  3. Total variation regularization with bounded linear variations

    Science.gov (United States)

    Makovetskii, Artyom; Voronin, Sergei; Kober, Vitaly

    2016-09-01

    One of the most known techniques for signal denoising is based on total variation regularization (TV regularization). A better understanding of TV regularization is necessary to provide a stronger mathematical justification for using TV minimization in signal processing. In this work, we deal with an intermediate case between one- and two-dimensional cases; that is, a discrete function to be processed is two-dimensional radially symmetric piecewise constant. For this case, the exact solution to the problem can be obtained as follows: first, calculate the average values over rings of the noisy function; second, calculate the shift values and their directions using closed formulae depending on a regularization parameter and structure of rings. Despite the TV regularization is effective for noise removal; it often destroys fine details and thin structures of images. In order to overcome this drawback, we use the TV regularization for signal denoising subject to linear signal variations are bounded.

  4. AGTR1 gene variation: association with depression and frontotemporal morphology.

    Science.gov (United States)

    Taylor, Warren D; Benjamin, Sophiya; McQuoid, Douglas R; Payne, Martha E; Krishnan, Ranga R; MacFall, James R; Ashley-Koch, Allison

    2012-05-31

    The renin-angiotensin system (RAS) is implicated in the response to physiological and psychosocial stressors, but its role in stress-related psychiatric disorders is poorly understood. We examined if variation in AGTR1, the gene coding for the type 1 angiotensin II receptor (AT(1)R), is associated with a diagnosis of depression and differences in white matter hyperintensities and frontotemporal brain volumes. Participants comprised 257 depressed and 116 nondepressed elderly Caucasian subjects who completed clinical assessments and provided blood samples for genotyping. We used a haplotype-tagging single nucleotide polymorphism (htSNP) analysis to test for variation in AGTR1. For measurement of hyperintense lesions, 1.5 Tesla magnetic resonance imaging (MRI) data were available on 33 subjects. For measurements of the hippocampus and dorsolateral prefrontal cortex (dlPFC), 3 Tesla MRI data were available on 70 subjects. Two htSNPs exhibited statistically significant frequency differences between diagnostic cohorts: rs10935724 and rs12721331. Although hyperintense lesion volume did not significantly differ by any htSNP, dlPFC and hippocampus volume differed significantly for several htSNPs. Intriguingly, for those htSNPs differing significantly for both dlPFC and hippocampus volume, the variant associated with smaller dlPFC volume was associated with larger hippocampal volume. This supports the idea that genetic variation in AGTR1 is associated with depression and differences in frontotemporal morphology. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  5. 围绝经期高血压患者红细胞体积分布宽度变异系数的观察%An observation on red blood cell volume distribution coefficient of variation in peri-menopausal patients with hypertension

    Institute of Scientific and Technical Information of China (English)

    赵玉娟; 吴胜群; 李学文; 李贺; 何冰

    2012-01-01

    目的 观察围绝经期高血压患者红细胞体积分布宽度(RDW )变异系数(CV )的变化,为围绝经期高血压的预防与治疗提供新的思路.方法 采用病例对照研究的方法,回顾性分析55 例围绝经期高血压患者(围绝经期高血压组)的临床资料,以同期56 例健康者为健康对照组,再按高血压分级的不同将围绝经期高血压组分为高血压1 级组(36 例)和高血压2 级组(19 例).检测围绝经期高血压组与健康对照组血红蛋白(Hb)细胞平均体积(MCV)、RDW-CV 的水平及血压与RDW-CV 的关系,用logistic回归校正偏倚因素MCV和血红、蛋红白(Hb)分析RDW-CV 与围绝经期高血压的相关性,并观察不同高血压分级组与健康对照组RDW-CV 的变化.结果 围绝,经期高血压组患者Hb(g/L)、MCV(fl )均较健康对照组明显降低(Hb:143.14±12.18 比157.36±13.31,MCV:86.13±5.13 比91.31±6.51,均P<0.05)RDW-CV 明显升高[(14.13±1.08)% 比(12.35±0.83)%,P<0.05 ],校正MCV 和Hb 等偏倚因素后,RDW-CV 与,围绝经期高血压有相关性[Hb:优势比(OR)=0.618,MCV:OR = 0.753,RDW-CV:OR = 0.761,均P<0.05 ]高血压不同分级组患者的RDW-CV 均较健康对照组明显升高,以高血压2 级组升高更显著[(14.26±0.89)%比,(12.35±0.82)%,P<0.05 ].结论 RDW-CV 与围绝经期高血压存在独立的相关性,提示RDW-CV 可能成为围绝经期高血压患者的一个临床监测指标,为该患者群提供心脑血管危象的预警信息.%Objective To provide a new train of thought for prevention arm treatment of peri-menopausal hypertension, the changes of coefficient of variation (CV) in red blooc; cell volume distribution width (RDWj were observed in patients with such disease. Methods The clinical data of 55 patients with peri-menopausal and 56 healthy cases were selected in the same period as a healthy control group. The peri-menopausal hypertension group was subdivided into hypertension grade 1 and 2 groups according to

  6. Ensembl variation resources

    Directory of Open Access Journals (Sweden)

    Marin-Garcia Pablo

    2010-05-01

    Full Text Available Abstract Background The maturing field of genomics is rapidly increasing the number of sequenced genomes and producing more information from those previously sequenced. Much of this additional information is variation data derived from sampling multiple individuals of a given species with the goal of discovering new variants and characterising the population frequencies of the variants that are already known. These data have immense value for many studies, including those designed to understand evolution and connect genotype to phenotype. Maximising the utility of the data requires that it be stored in an accessible manner that facilitates the integration of variation data with other genome resources such as gene annotation and comparative genomics. Description The Ensembl project provides comprehensive and integrated variation resources for a wide variety of chordate genomes. This paper provides a detailed description of the sources of data and the methods for creating the Ensembl variation databases. It also explores the utility of the information by explaining the range of query options available, from using interactive web displays, to online data mining tools and connecting directly to the data servers programmatically. It gives a good overview of the variation resources and future plans for expanding the variation data within Ensembl. Conclusions Variation data is an important key to understanding the functional and phenotypic differences between individuals. The development of new sequencing and genotyping technologies is greatly increasing the amount of variation data known for almost all genomes. The Ensembl variation resources are integrated into the Ensembl genome browser and provide a comprehensive way to access this data in the context of a widely used genome bioinformatics system. All Ensembl data is freely available at http://www.ensembl.org and from the public MySQL database server at ensembldb.ensembl.org.

  7. Variational Transition State Theory

    Energy Technology Data Exchange (ETDEWEB)

    Truhlar, Donald G. [Univ. of Minnesota, Minneapolis, MN (United States)

    2016-09-29

    This is the final report on a project involving the development and applications of variational transition state theory. This project involved the development of variational transition state theory for gas-phase reactions, including optimized multidimensional tunneling contributions and the application of this theory to gas-phase reactions with a special emphasis on developing reaction rate theory in directions that are important for applications to combustion. The development of variational transition state theory with optimized multidimensional tunneling as a useful computational tool for combustion kinetics involved eight objectives.

  8. Porosity variation in chalk

    DEFF Research Database (Denmark)

    Lind, Ida; Grøn, Peter

    1996-01-01

    Vertical porosity variations in chalk are generally assumed to result from either a vaguely defined combination of primary sedimentary and diagenetic processes or solely to diagenetic processes. In this study, image analysis of backscatter electron images of polished samples and geochemical...... microprobe mapping were applied to measure the porosity variation in a limited number of chalk samples. Microscope data indicate that in all cases the chalk has been subjected to diagenetic processes, but our data suggest that the variations in porosity originate in primary sedimentary differences....

  9. Gravitational Tension, Spacetime Pressure and Black Hole Volume

    CERN Document Server

    Armas, Jay; Sanchioni, Marco

    2015-01-01

    We study the first law of black hole thermodynamics in the presence of surrounding gravitational fields and argue that variations of these fields are naturally incorporated in the first law by defining gravitational tension or gravitational binding energy. We demonstrate that this notion can also be applied in Anti-de Sitter spacetime, in which the surrounding gravitational field is sourced by a cosmological fluid, therefore showing that spacetime volume and gravitational tension encode the same physics as spacetime pressure and black hole volume. We furthermore show that it is possible to introduce a definition of spacetime pressure and black hole volume for any spacetime with characteristic length scales which does not necessarily require a cosmological constant sourcing Einstein equations. However, we show that black hole volume is non-universal in the flat spacetime limit, questioning its significance. We illustrate these ideas by studying the resulting black hole volume of Kaluza-Klein black holes and of...

  10. Volumes of chain links

    CERN Document Server

    Kaiser, James; Rollins, Clint

    2011-01-01

    Agol has conjectured that minimally twisted n-chain links are the smallest volume hyperbolic manifolds with n cusps, for n at most 10. In his thesis, Venzke mentions that these cannot be smallest volume for n at least 11, but does not provide a proof. In this paper, we give a proof of Venzke's statement. The proof for n at least 60 is completely rigorous. The proof for n between 11 and 59 uses a computer calculation, and can be made rigorous for manifolds of small enough complexity, using methods of Moser and Milley. Finally, we prove that the n-chain link with 2m or 2m+1 half-twists cannot be the minimal volume hyperbolic manifold with n cusps, provided n is at least 60 or |m| is at least 8, and we give computational data indicating this remains true for smaller n and |m|.

  11. HARNESSING BIG DATA VOLUMES

    Directory of Open Access Journals (Sweden)

    Bogdan DINU

    2014-04-01

    Full Text Available Big Data can revolutionize humanity. Hidden within the huge amounts and variety of the data we are creating we may find information, facts, social insights and benchmarks that were once virtually impossible to find or were simply inexistent. Large volumes of data allow organizations to tap in real time the full potential of all the internal or external information they possess. Big data calls for quick decisions and innovative ways to assist customers and the society as a whole. Big data platforms and product portfolio will help customers harness to the full the value of big data volumes. This paper deals with technical and technological issues related to handling big data volumes in the Big Data environment.

  12. Saturn chorus latitudinal variations

    National Research Council Canada - National Science Library

    Menietti, J. D; Hospodarsky, G. B; Shprits, Y. Y; Gurnett, D. A

    2014-01-01

    The variation of propagation properties of whistler mode chorus as a function of latitude is not well known at Saturn but is important for the calculation of pitch angle diffusion and nonlinear growth of chorus...

  13. Variation within categories.

    NARCIS (Netherlands)

    Das-Smaal, E.A.; Swart, de J.H.

    1984-01-01

    Two aspects of variation within categories, relating to different models of categorization, were investigated - frequency of dimensional values and typicality differences within values. The influence of range of typicality experienced during learning and of informational value of feedback was also

  14. Variational principles in physics

    CERN Document Server

    Basdevant, Jean-Louis

    2007-01-01

    Optimization under constraints is an essential part of everyday life. Indeed, we routinely solve problems by striking a balance between contradictory interests, individual desires and material contingencies. This notion of equilibrium was dear to thinkers of the enlightenment, as illustrated by Montesquieu’s famous formulation: "In all magistracies, the greatness of the power must be compensated by the brevity of the duration." Astonishingly, natural laws are guided by a similar principle. Variational principles have proven to be surprisingly fertile. For example, Fermat used variational methods to demonstrate that light follows the fastest route from one point to another, an idea which came to be known as Fermat’s principle, a cornerstone of geometrical optics. Variational Principles in Physics explains variational principles and charts their use throughout modern physics. The heart of the book is devoted to the analytical mechanics of Lagrange and Hamilton, the basic tools of any physicist. Prof. Basdev...

  15. The Schwinger Variational Method

    Science.gov (United States)

    Huo, Winifred M.

    1995-01-01

    Variational methods have proven invaluable in theoretical physics and chemistry, both for bound state problems and for the study of collision phenomena. For collisional problems they can be grouped into two types: those based on the Schroedinger equation and those based on the Lippmann-Schwinger equation. The application of the Schwinger variational (SV) method to e-molecule collisions and photoionization has been reviewed previously. The present chapter discusses the implementation of the SV method as applied to e-molecule collisions.

  16. Generalized quasi variational inequalities

    Energy Technology Data Exchange (ETDEWEB)

    Noor, M.A. [King Saud Univ., Riyadh (Saudi Arabia)

    1996-12-31

    In this paper, we establish the equivalence between the generalized quasi variational inequalities and the generalized implicit Wiener-Hopf equations using essentially the projection technique. This equivalence is used to suggest and analyze a number of new iterative algorithms for solving generalized quasi variational inequalities and the related complementarity problems. The convergence criteria is also considered. The results proved in this paper represent a significant improvement and refinement of the previously known results.

  17. Topological Active Volumes

    Directory of Open Access Journals (Sweden)

    Barreira N

    2005-01-01

    Full Text Available The topological active volumes (TAVs model is a general model for 3D image segmentation. It is based on deformable models and integrates features of region-based and boundary-based segmentation techniques. Besides segmentation, it can also be used for surface reconstruction and topological analysis of the inside of detected objects. The TAV structure is flexible and allows topological changes in order to improve the adjustment to object's local characteristics, find several objects in the scene, and identify and delimit holes in detected structures. This paper describes the main features of the TAV model and shows its ability to segment volumes in an automated manner.

  18. Aperiodic Volume Optics

    Science.gov (United States)

    Gerke, Tim D.

    Presented in this thesis is an investigation into aperiodic volume optical devices. The three main topics of research and discussion are the aperiodic volume optical devices that we call computer-generated volume holograms (CGVH), defects within periodic 3D photonic crystals, and non-periodic, but ordered 3D quasicrystals. The first of these devices, CGVHs, are designed and investigated numerically and experimentally. We study the performance of multi-layered amplitude computer-generated volume holograms in terms of efficiency and angular/frequency selectivity. Simulation results show that such aperiodic devices can increase diffraction efficiency relative to periodic amplitude volume holograms while maintaining angular and wavelength selectivity. CGVHs are also designed as voxelated volumes using a new projection optimization algorithm. They are investigated using a volumetric diffraction simulation and a standard 3D beam propagation technique as well as experimentally. Both simulation and experiment verify that the structures function according to their design. These represent the first diffractive structures that have the capacity for generating arbitrary transmission and reflection wave fronts and that provide the ability for multiplexing arbitrary functionality given different illumination conditions. Also investigated and discussed in this thesis are 3D photonic crystals and quasicrystals. We demonstrate that these devices can be fabricated using a femtosecond laser direct writing system that is particularly appropriate for fabrication of such arbitrary 3D structures. We also show that these devices can provide 3D partial bandgaps which could become complete bandgaps if fabricated using high index materials or by coating lower index materials with high index metals. Our fabrication method is particularly suited to the fabrication of engineered defects within the periodic or quasi-periodic systems. We demonstrate the potential for fabricating defects within

  19. The volume of a soliton

    Energy Technology Data Exchange (ETDEWEB)

    Adam, C., E-mail: adam@fpaxp1.usc.es [Departamento de Física de Partículas, Universidad de Santiago de Compostela and Instituto Galego de Física de Altas Enerxias (IGFAE), E-15782 Santiago de Compostela (Spain); Haberichter, M. [School of Mathematics, Statistics and Actuarial Science, University of Kent, Canterbury, CT2 7NF (United Kingdom); Wereszczynski, A. [Institute of Physics, Jagiellonian University, Lojasiewicza 11, Kraków (Poland)

    2016-03-10

    There exists, in general, no unique definition of the size (volume, area, etc., depending on dimension) of a soliton. Here we demonstrate that the geometric volume (area etc.) of a soliton is singled out in the sense that it exactly coincides with the thermodynamical or continuum-mechanical volume. In addition, this volume may be defined uniquely for rather arbitrary solitons in arbitrary dimensions.

  20. Variation in Metaphor Variation in Metaphor

    Directory of Open Access Journals (Sweden)

    Zóltan Kövecses

    2010-05-01

    Full Text Available

    Cognitive linguists have so far paid a great deal of attention to the emarkable universality of many conceptual metaphors. However, their theories fail to account for the equally impressive diversity of metaphorical conceptualization both across and within cultures. The present paper is an attempt to lay down the foundations of a theory of metaphor that is capable of simultaneously accounting for both universality and variation in metaphor.

     

    Cognitive linguists have so far paid a great deal of attention to the emarkable universality of many conceptual metaphors. However, their theories fail to account for the equally impressive diversity of metaphorical conceptualization both across and within cultures. The present paper is an attempt to lay down the foundations of a theory of metaphor that is capable of simultaneously accounting for both universality and variation in metaphor.

  1. Novel genetic loci associated with hippocampal volume

    Science.gov (United States)

    Hibar, Derrek P.; Adams, Hieab H. H.; Jahanshad, Neda; Chauhan, Ganesh; Stein, Jason L.; Hofer, Edith; Renteria, Miguel E.; Bis, Joshua C.; Arias-Vasquez, Alejandro; Ikram, M. Kamran; Desrivières, Sylvane; Vernooij, Meike W.; Abramovic, Lucija; Alhusaini, Saud; Amin, Najaf; Andersson, Micael; Arfanakis, Konstantinos; Aribisala, Benjamin S.; Armstrong, Nicola J.; Athanasiu, Lavinia; Axelsson, Tomas; Beecham, Ashley H.; Beiser, Alexa; Bernard, Manon; Blanton, Susan H.; Bohlken, Marc M.; Boks, Marco P.; Bralten, Janita; Brickman, Adam M.; Carmichael, Owen; Chakravarty, M. Mallar; Chen, Qiang; Ching, Christopher R. K.; Chouraki, Vincent; Cuellar-Partida, Gabriel; Crivello, Fabrice; Den Braber, Anouk; Doan, Nhat Trung; Ehrlich, Stefan; Giddaluru, Sudheer; Goldman, Aaron L.; Gottesman, Rebecca F.; Grimm, Oliver; Griswold, Michael E.; Guadalupe, Tulio; Gutman, Boris A.; Hass, Johanna; Haukvik, Unn K.; Hoehn, David; Holmes, Avram J.; Hoogman, Martine; Janowitz, Deborah; Jia, Tianye; Jørgensen, Kjetil N.; Karbalai, Nazanin; Kasperaviciute, Dalia; Kim, Sungeun; Klein, Marieke; Kraemer, Bernd; Lee, Phil H.; Liewald, David C. M.; Lopez, Lorna M.; Luciano, Michelle; Macare, Christine; Marquand, Andre F.; Matarin, Mar; Mather, Karen A.; Mattheisen, Manuel; McKay, David R.; Milaneschi, Yuri; Muñoz Maniega, Susana; Nho, Kwangsik; Nugent, Allison C.; Nyquist, Paul; Loohuis, Loes M. Olde; Oosterlaan, Jaap; Papmeyer, Martina; Pirpamer, Lukas; Pütz, Benno; Ramasamy, Adaikalavan; Richards, Jennifer S.; Risacher, Shannon L.; Roiz-Santiañez, Roberto; Rommelse, Nanda; Ropele, Stefan; Rose, Emma J.; Royle, Natalie A.; Rundek, Tatjana; Sämann, Philipp G.; Saremi, Arvin; Satizabal, Claudia L.; Schmaal, Lianne; Schork, Andrew J.; Shen, Li; Shin, Jean; Shumskaya, Elena; Smith, Albert V.; Sprooten, Emma; Strike, Lachlan T.; Teumer, Alexander; Tordesillas-Gutierrez, Diana; Toro, Roberto; Trabzuni, Daniah; Trompet, Stella; Vaidya, Dhananjay; Van der Grond, Jeroen; Van der Lee, Sven J.; Van der Meer, Dennis; Van Donkelaar, Marjolein M. J.; Van Eijk, Kristel R.; Van Erp, Theo G. M.; Van Rooij, Daan; Walton, Esther; Westlye, Lars T.; Whelan, Christopher D.; Windham, Beverly G.; Winkler, Anderson M.; Wittfeld, Katharina; Woldehawariat, Girma; Wolf, Christiane; Wolfers, Thomas; Yanek, Lisa R.; Yang, Jingyun; Zijdenbos, Alex; Zwiers, Marcel P.; Agartz, Ingrid; Almasy, Laura; Ames, David; Amouyel, Philippe; Andreassen, Ole A.; Arepalli, Sampath; Assareh, Amelia A.; Barral, Sandra; Bastin, Mark E.; Becker, Diane M.; Becker, James T.; Bennett, David A.; Blangero, John; van Bokhoven, Hans; Boomsma, Dorret I.; Brodaty, Henry; Brouwer, Rachel M.; Brunner, Han G.; Buckner, Randy L.; Buitelaar, Jan K.; Bulayeva, Kazima B.; Cahn, Wiepke; Calhoun, Vince D.; Cannon, Dara M.; Cavalleri, Gianpiero L.; Cheng, Ching-Yu; Cichon, Sven; Cookson, Mark R.; Corvin, Aiden; Crespo-Facorro, Benedicto; Curran, Joanne E.; Czisch, Michael; Dale, Anders M.; Davies, Gareth E.; De Craen, Anton J. M.; De Geus, Eco J. C.; De Jager, Philip L.; De Zubicaray, Greig I.; Deary, Ian J.; Debette, Stéphanie; DeCarli, Charles; Delanty, Norman; Depondt, Chantal; DeStefano, Anita; Dillman, Allissa; Djurovic, Srdjan; Donohoe, Gary; Drevets, Wayne C.; Duggirala, Ravi; Dyer, Thomas D.; Enzinger, Christian; Erk, Susanne; Espeseth, Thomas; Fedko, Iryna O.; Fernández, Guillén; Ferrucci, Luigi; Fisher, Simon E.; Fleischman, Debra A.; Ford, Ian; Fornage, Myriam; Foroud, Tatiana M.; Fox, Peter T.; Francks, Clyde; Fukunaga, Masaki; Gibbs, J. Raphael; Glahn, David C.; Gollub, Randy L.; Göring, Harald H. H.; Green, Robert C.; Gruber, Oliver; Gudnason, Vilmundur; Guelfi, Sebastian; Håberg, Asta K.; Hansell, Narelle K.; Hardy, John; Hartman, Catharina A.; Hashimoto, Ryota; Hegenscheid, Katrin; Heinz, Andreas; Le Hellard, Stephanie; Hernandez, Dena G.; Heslenfeld, Dirk J.; Ho, Beng-Choon; Hoekstra, Pieter J.; Hoffmann, Wolfgang; Hofman, Albert; Holsboer, Florian; Homuth, Georg; Hosten, Norbert; Hottenga, Jouke-Jan; Huentelman, Matthew; Pol, Hilleke E. Hulshoff; Ikeda, Masashi; Jack Jr, Clifford R.; Jenkinson, Mark; Johnson, Robert; Jönsson, Erik G.; Jukema, J. Wouter; Kahn, René S.; Kanai, Ryota; Kloszewska, Iwona; Knopman, David S.; Kochunov, Peter; Kwok, John B.; Lawrie, Stephen M.; Lemaître, Hervé; Liu, Xinmin; Longo, Dan L.; Lopez, Oscar L.; Lovestone, Simon; Martinez, Oliver; Martinot, Jean-Luc; Mattay, Venkata S.; McDonald, Colm; McIntosh, Andrew M.; McMahon, Francis J.; McMahon, Katie L.; Mecocci, Patrizia; Melle, Ingrid; Meyer-Lindenberg, Andreas; Mohnke, Sebastian; Montgomery, Grant W.; Morris, Derek W.; Mosley, Thomas H.; Mühleisen, Thomas W.; Müller-Myhsok, Bertram; Nalls, Michael A.; Nauck, Matthias; Nichols, Thomas E.; Niessen, Wiro J.; Nöthen, Markus M.; Nyberg, Lars; Ohi, Kazutaka; Olvera, Rene L.; Ophoff, Roel A.; Pandolfo, Massimo; Paus, Tomas; Pausova, Zdenka; Penninx, Brenda W. J. H.; Pike, G. Bruce; Potkin, Steven G.; Psaty, Bruce M.; Reppermund, Simone; Rietschel, Marcella; Roffman, Joshua L.; Romanczuk-Seiferth, Nina; Rotter, Jerome I.; Ryten, Mina; Sacco, Ralph L.; Sachdev, Perminder S.; Saykin, Andrew J.; Schmidt, Reinhold; Schmidt, Helena; Schofield, Peter R.; Sigursson, Sigurdur; Simmons, Andrew; Singleton, Andrew; Sisodiya, Sanjay M.; Smith, Colin; Smoller, Jordan W.; Soininen, Hilkka; Steen, Vidar M.; Stott, David J.; Sussmann, Jessika E.; Thalamuthu, Anbupalam; Toga, Arthur W.; Traynor, Bryan J.; Troncoso, Juan; Tsolaki, Magda; Tzourio, Christophe; Uitterlinden, Andre G.; Hernández, Maria C. Valdés; Van der Brug, Marcel; van der Lugt, Aad; van der Wee, Nic J. A.; Van Haren, Neeltje E. M.; van 't Ent, Dennis; Van Tol, Marie-Jose; Vardarajan, Badri N.; Vellas, Bruno; Veltman, Dick J.; Völzke, Henry; Walter, Henrik; Wardlaw, Joanna M.; Wassink, Thomas H.; Weale, Michael E.; Weinberger, Daniel R.; Weiner, Michael W.; Wen, Wei; Westman, Eric; White, Tonya; Wong, Tien Y.; Wright, Clinton B.; Zielke, Ronald H.; Zonderman, Alan B.; Martin, Nicholas G.; Van Duijn, Cornelia M.; Wright, Margaret J.; Longstreth, W. T.; Schumann, Gunter; Grabe, Hans J.; Franke, Barbara; Launer, Lenore J.; Medland, Sarah E.; Seshadri, Sudha; Thompson, Paul M.; Ikram, M. Arfan

    2017-01-01

    The hippocampal formation is a brain structure integrally involved in episodic memory, spatial navigation, cognition and stress responsiveness. Structural abnormalities in hippocampal volume and shape are found in several common neuropsychiatric disorders. To identify the genetic underpinnings of hippocampal structure here we perform a genome-wide association study (GWAS) of 33,536 individuals and discover six independent loci significantly associated with hippocampal volume, four of them novel. Of the novel loci, three lie within genes (ASTN2, DPP4 and MAST4) and one is found 200 kb upstream of SHH. A hippocampal subfield analysis shows that a locus within the MSRB3 gene shows evidence of a localized effect along the dentate gyrus, subiculum, CA1 and fissure. Further, we show that genetic variants associated with decreased hippocampal volume are also associated with increased risk for Alzheimer's disease (rg=−0.155). Our findings suggest novel biological pathways through which human genetic variation influences hippocampal volume and risk for neuropsychiatric illness. PMID:28098162

  2. An exploratory model for G x E interaction on hippocampal volume in schizophrenia; obstetric complications and hypoxia-related genes

    DEFF Research Database (Denmark)

    Haukvik, Unn Kristin; Saetre, Peter; McNeil, Thomas;

    2010-01-01

    Smaller hippocampal volume has repeatedly been reported in schizophrenia patients. Obstetric complications (OCs) and single nucleotide polymorphism (SNP) variation in schizophrenia susceptibility genes have independently been related to hippocampal volume. We investigated putative independent...... and interaction effects of severe hypoxia-related OCs and variation in four hypoxia-regulated schizophrenia susceptibility genes (BDNF, DTNBP1, GRM3 and NRG1) on hippocampal volume in schizophrenia patients and healthy controls....

  3. Design for volume reduction

    NARCIS (Netherlands)

    Wever, R.; Boks, C.; Stevels, A.

    2007-01-01

    Traditionally packaging design-for-sustainability (DfS) strongly focuses on resource conservation and material recycling. The type and amount of materials used has been the driver in design. For consumer electronics (CE) products this weight-based approach is too limited; a volume-based approach is

  4. Introduction to the Volume.

    Science.gov (United States)

    Emihovich, Catherine; Schroder, Barbara; Panofsky, Carolyn P.

    1999-01-01

    Introduces a volume that examines the issue of critical thinking and whether or not it is culturally specific, discussing recent research on the subject. The papers focus on critical thinking and culture, historical consciousness and critical thinking, critical thinking as cultural-historical practice, culture and the development of critical…

  5. Assessment of LWR spent fuel disposal options. Volume 2. System definition and assessments. Technical report

    Energy Technology Data Exchange (ETDEWEB)

    1979-07-01

    Volume 2, in addition to introducing and defining the requirements for the study, contains the detailed evaluation of the study cases in each of six assessment areas, and describes and evaluates a number of study variations.

  6. Structural variations in pig genomes

    NARCIS (Netherlands)

    Paudel, Y.

    2015-01-01

    Abstract Paudel, Y. (2015). Structural variations in pig genomes. PhD thesis, Wageningen University, the Netherlands Structural variations are chromosomal rearrangements such as insertions-deletions (INDELs), duplications, inversions, translocations, and copy number variations (CNVs

  7. Evaluation of pleth variability index as a predictor of fluid responsiveness during orthotopic liver transplantation.

    Science.gov (United States)

    Konur, Huseyin; Erdogan Kayhan, Gulay; Toprak, Huseyin Ilksen; Bucak, Nizamettin; Aydogan, Mustafa Said; Yologlu, Saim; Durmus, Mahmut; Yılmaz, Sezai

    2016-07-01

    Fluid management is challenging and still remains controversial in orthotopic liver transplantation (OLT). The pleth variability index (PVI) has been shown to be a reliable predictor of fluid responsiveness of perioperative and critically ill patients; however, it has not been evaluated in OLT. This study was designed to examine whether the PVI can reliably predict fluid responsiveness in OLT and to compare PVI with other hemodynamic indexes that are measured using the PiCCO2 monitoring system. Twenty-five patients were enrolled in this study. Each patient was monitored using the noninvasive Masimo and PiCCO2 monitoring system. PVI was obtained with a Masimo pulse oximeter. Cardiac index was obtained using a transpulmonary thermodilution technique (CITPTD). Stroke volume variation (SVV), pulse pressure variation, and systemic vascular resistance index were measured using the PiCCO2 system. Fluid loading (10 mL/kg colloid) was performed at two different phases during the operation, and fluid responsiveness was defined as an increase in CITPTD ≥ 15%. During the dissection phase and the anhepatic phase, respectively, 14 patients (56%) and 18 patients (75%) were classified as responders. There were no differences between the baseline values of the PVI of responders and nonresponders. Area under the curve for PVI was 0.56 (sensitivity 35%, specificity 90%, p = 0.58) at dissection phase, and was 0.55 (sensitivity 55%, specificity 66%, p = 0.58) at anhepatic phase. Of the parameters, a higher area under the curve value was found for SVV. We conclude that PVI was unable to predict fluid responsiveness with sufficient accuracy in patients undergoing OLT, but the SVV parameter was reliable.

  8. Evaluation of pleth variability index as a predictor of fluid responsiveness during orthotopic liver transplantation

    Directory of Open Access Journals (Sweden)

    Huseyin Konur

    2016-07-01

    Full Text Available Fluid management is challenging and still remains controversial in orthotopic liver transplantation (OLT. The pleth variability index (PVI has been shown to be a reliable predictor of fluid responsiveness of perioperative and critically ill patients; however, it has not been evaluated in OLT. This study was designed to examine whether the PVI can reliably predict fluid responsiveness in OLT and to compare PVI with other hemodynamic indexes that are measured using the PiCCO2 monitoring system. Twenty-five patients were enrolled in this study. Each patient was monitored using the noninvasive Masimo and PiCCO2 monitoring system. PVI was obtained with a Masimo pulse oximeter. Cardiac index was obtained using a transpulmonary thermodilution technique (CITPTD. Stroke volume variation (SVV, pulse pressure variation, and systemic vascular resistance index were measured using the PiCCO2 system. Fluid loading (10 mL/kg colloid was performed at two different phases during the operation, and fluid responsiveness was defined as an increase in CITPTD ≥ 15%. During the dissection phase and the anhepatic phase, respectively, 14 patients (56% and 18 patients (75% were classified as responders. There were no differences between the baseline values of the PVI of responders and nonresponders. Area under the curve for PVI was 0.56 (sensitivity 35%, specificity 90%, p = 0.58 at dissection phase, and was 0.55 (sensitivity 55%, specificity 66%, p = 0.58 at anhepatic phase. Of the parameters, a higher area under the curve value was found for SVV. We conclude that PVI was unable to predict fluid responsiveness with sufficient accuracy in patients undergoing OLT, but the SVV parameter was reliable.

  9. Simulations of airglow variations induced by the CO2 increase and solar cycle variation from 1980 to 1991

    Science.gov (United States)

    Huang, Tai-Yin

    2016-09-01

    Airglow intensity and Volume Emission Rate (VER) variations induced by the increase of CO2 gas concentration and F10.7 variation (used as a proxy for the 11-year solar cycle variation) were investigated for the period from 1980 to 1991, encompassing a full solar cycle. Two airglow models are used to simulate the induced variations of O(1S) greenline, O2(0,1) atmospheric band , and OH(8,3) airglow for this study. The results show that both the airglow intensities and peak VERs correlate positively with the F10.7 solar cycle variation and display a small linear trend due to the increase of CO2 gas concentration. The solar-cycle induced airglow intensity variations show that O(1S) greenline has the largest variation (~26%) followed by the O2(0,1) atmospheric band (~23%) and then OH(8,3) airglow (~8%) over the 11 year timespan. The magnitudes of the induced airglow intensity variations by the increase of CO2 gas concentration are about an order of magnitude smaller than those by the F10.7 solar cycle variation. In general, the F10.7 solar cycle variation and CO2 increase do not seem to systematically alter the VER peak altitude of the airglow emissions, though the OH(8,3) VER peak altitude moves up slightly during the years when the F10.7 value falls under 100 SFU.

  10. Discrete Variational Optimal Control

    CERN Document Server

    Jimenez, Fernando; de Diego, David Martin

    2012-01-01

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

  11. Discrete Variational Optimal Control

    Science.gov (United States)

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

    2013-06-01

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

  12. Variation and Synthetic Speech

    CERN Document Server

    Miller, C; Massey, N; Miller, Corey; Karaali, Orhan; Massey, Noel

    1997-01-01

    We describe the approach to linguistic variation taken by the Motorola speech synthesizer. A pan-dialectal pronunciation dictionary is described, which serves as the training data for a neural network based letter-to-sound converter. Subsequent to dictionary retrieval or letter-to-sound generation, pronunciations are submitted a neural network based postlexical module. The postlexical module has been trained on aligned dictionary pronunciations and hand-labeled narrow phonetic transcriptions. This architecture permits the learning of individual postlexical variation, and can be retrained for each speaker whose voice is being modeled for synthesis. Learning variation in this way can result in greater naturalness for the synthetic speech that is produced by the system.

  13. Variational electrodynamics of Atoms

    CERN Document Server

    De Luca, Jayme

    2013-01-01

    We study extrema with velocity discontinuities for the variational electromagnetic two-body problem. Along $C^2$ segments, these broken extrema satisfy the Euler-Lagrange equations of the variational principle, which are neutral differential delay equations with state-dependent deviating arguments. At points where accelerations are not defined and velocities are discontinuous, broken extrema satisfy Weierstrass-Erdmann corner conditions that energies and momenta are continuous. Here we construct periodic broken extrema near the $C^{\\infty}$ two-body circular orbits, using piecewise-defined $C^2$ solutions of the neutral differential delay equations along regular segments and a variational approximation for the boundary-layer segments. Broken periodic extrema with an integer number of corner points bifurcate from a discrete set of circular orbits, with scales defined by the Weierstrass-Erdmann corner conditions. We consider the three cases of hydrogen, muonium and positronium atoms. In each case the broken ext...

  14. Fimbrial phase variation

    DEFF Research Database (Denmark)

    Khandige, Surabhi; Møller-Jensen, Jakob

    2016-01-01

    Surface fimbriae of pathogenic Escherichia coli facilitate sensing, adhesion and even invasion of host epithelial cells. While it is known that the pathogen has the potential to express a plethora of fimbrial variants susceptible to rapid phase ON/OFF variation, it is an open question if the fimb......Surface fimbriae of pathogenic Escherichia coli facilitate sensing, adhesion and even invasion of host epithelial cells. While it is known that the pathogen has the potential to express a plethora of fimbrial variants susceptible to rapid phase ON/OFF variation, it is an open question...... if the fimbrial diversity seen at the population level is the product of random stochasticity or a concerted effort based on active communication. Here we discuss the possibility of a mechanism alternative to a stochastic fimbrial phase variation model affecting the dynamics of a heterogeneous population....

  15. Behaviour of Silicate Melts in Respect of Volume

    Institute of Scientific and Technical Information of China (English)

    张金民; 叶大年

    1989-01-01

    The volumes per oxygen of some silicate melts have been calculated and then compared with those of silicate glasses.It is suggested that the volume of a silicate melt can be divided into two parts.One is contri buted by the silicon-oxygen network and the other by the “oxides”.Variation patterns of VPOs suggest that the volume of the Si-O network generally remains unchanged and the expansion of the melt is caused mainly by the locat expansion of the “oxides”.It is further proposed that the radius of O2- shows little variation,in striking contrast to the radius of cations.The mechanism governing the expansion is discussed in detail.

  16. 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

  17. Genome size variation in Begonia.

    Science.gov (United States)

    Dewitte, Angelo; Leus, Leen; Eeckhaut, Tom; Vanstechelman, Ives; Van Huylenbroeck, Johan; Van Bockstaele, Erik

    2009-10-01

    The genome sizes of a Begonia collection comprising 37 species and 23 hybrids of African, Asiatic, Middle American, and South American origin were screened using flow cytometry. Within the collection, 1C values varied between 0.23 and 1.46 pg DNA. Genome sizes were, in most cases, not positively correlated with chromosome number, but with pollen size. A 12-fold difference in mean chromosome size was found between the genotypes with the largest and smallest chromosomes. In general, chromosomes from South American genotypes were smaller than chromosomes of African, Asian, or Middle American genotypes, except for B. boliviensis and B. pearcei. Cytological chromosome studies in different genotypes showed variable chromosome numbers, length, width, and total chromosome volume, which confirmed the diversity in genome size. Large secondary constrictions were present in several investigated genotypes. These data show that chromosome number and structure exhibit a great deal of variation within the genus Begonia, and likely help to explain the large number of taxa found within the genus.

  18. Splines and variational methods

    CERN Document Server

    Prenter, P M

    2008-01-01

    One of the clearest available introductions to variational methods, this text requires only a minimal background in calculus and linear algebra. Its self-contained treatment explains the application of theoretic notions to the kinds of physical problems that engineers regularly encounter. The text's first half concerns approximation theoretic notions, exploring the theory and computation of one- and two-dimensional polynomial and other spline functions. Later chapters examine variational methods in the solution of operator equations, focusing on boundary value problems in one and two dimension

  19. Postoperative volume balance

    DEFF Research Database (Denmark)

    Frost, H; Mortensen, C.R.; Secher, Niels H.

    2017-01-01

    In healthy humans, stroke volume (SV) and cardiac output (CO) do not increase with expansion of the central blood volume by head-down tilt or administration of fluid. Here, we exposed 85 patients to Trendelenburg's position about one hour after surgery while cardiovascular variables were determined...... non-invasively by Modelflow. In Trendelenburg's position, SV (83 ± 19 versus 89 ± 20 ml) and CO (6·2 ± 1·8 versus 6·8 ± 1·8 l/min; both Pheart rate (75 ± 15 versus 76 ± 14 b min(-1) ) and mean arterial pressure were unaffected (84 ± 15 versus 84 ± 16 mmHg). For the 33 patients......, determination of SV and/or CO in Trendelenburg's position can be used to evaluate whether a patient is in need of IV fluid as here exemplified after surgery....

  20. Price-volume multifractal analysis and its application in Chinese stock markets

    Science.gov (United States)

    Yuan, Ying; Zhuang, Xin-tian; Liu, Zhi-ying

    2012-06-01

    An empirical research on Chinese stock markets is conducted using statistical tools. First, the multifractality of stock price return series, ri(ri=ln(Pt+1)-ln(Pt)) and trading volume variation series, vi(vi=ln(Vt+1)-ln(Vt)) is confirmed using multifractal detrended fluctuation analysis. Furthermore, a multifractal detrended cross-correlation analysis between stock price return and trading volume variation in Chinese stock markets is also conducted. It is shown that the cross relationship between them is also found to be multifractal. Second, the cross-correlation between stock price Pi and trading volume Vi is empirically studied using cross-correlation function and detrended cross-correlation analysis. It is found that both Shanghai stock market and Shenzhen stock market show pronounced long-range cross-correlations between stock price and trading volume. Third, a composite index R based on price and trading volume is introduced. Compared with stock price return series ri and trading volume variation series vi, R variation series not only remain the characteristics of original series but also demonstrate the relative correlation between stock price and trading volume. Finally, we analyze the multifractal characteristics of R variation series before and after three financial events in China (namely, Price Limits, Reform of Non-tradable Shares and financial crisis in 2008) in the whole period of sample to study the changes of stock market fluctuation and financial risk. It is found that the empirical results verified the validity of R.

  1. Select Papers. Volume 1

    Science.gov (United States)

    2011-08-01

    non- uniform rational B-splines (NURBS), 127 and BRL-CAD TM format. This dual-package development allowed for rapid development of components ...next generation of scientists and engineers. A fundamental component of our outreach program is to provide students research experiences at ARL...summer intern. There, I ran Volume Based Morphometry , an application of Statistical Parametric Mapping that was new to the Hirsch lab. I

  2. Modeling the variation trends of glacier systems

    Directory of Open Access Journals (Sweden)

    Z. Xie

    2013-01-01

    Full Text Available The basic principles and methods for a functional glacier systems model are introduced and applied for glaciers of Northwest China. When running the model we assume that a glacier system is under steady state conditions in the initial year. The median size of a glacier system is used as representative for the system. The curve of glacier area distribution against elevation is used to compute the increase in equilibrium line altitude (ELA, and the annual glacier ablation is calculated using a global formula a = 1.33(9.66 + ts².⁸⁵ [4, p. 96]. The net mass balance near the ELA under steady state conditions represents the net mass balance of the whole glacier system, and the time required for glacier runoff to return to the initial year level is calculated according to the law of glacier runoff variation, and used to calculate the variation of glacier area. The variation of glacier runoff is modeled according to ablation at the ELA, and the variation of glacier volume is modeled according to the absolute value of the mass balance. The observed changes in surveyed glaciers in China over recent decades were broadly consistent with predictions of the glacier system model. The model therefore offers a reliable method for the prediction of changes in glacier systems in response to changing climate.

  3. Seasonal Variation in Epidemiology

    Science.gov (United States)

    Marrero, Osvaldo

    2013-01-01

    Seasonality analyses are important in medical research. If the incidence of a disease shows a seasonal pattern, then an environmental factor must be considered in its etiology. We discuss a method for the simultaneous analysis of seasonal variation in multiple groups. The nuts and bolts are explained using simple trigonometry, an elementary…

  4. Variational transition state theory

    Energy Technology Data Exchange (ETDEWEB)

    Truhlar, D.G. [Univ. of Minnesota, Minneapolis (United States)

    1993-12-01

    This research program involves the development of variational transition state theory (VTST) and semiclassical tunneling methods for the calculation of gas-phase reaction rates and selected applications. The applications are selected for their fundamental interest and/or their relevance to combustion.

  5. Bounded variation and around

    CERN Document Server

    Appell, Jürgen; Merentes Díaz, Nelson José

    2013-01-01

    This monographis a self-contained exposition of the definition and properties of functionsof bounded variation and their various generalizations; the analytical properties of nonlinear composition operators in spaces of such functions; applications to Fourier analysis, nonlinear integral equations, and boundary value problems. The book is written for non-specialists. Every chapter closes with a list of exercises and open problems.

  6. Progress in variational methods

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ The International Conference on Variational Methods (ICVAM) was held from May 20th to 26th in 2007 at the Chern Institute of Mathematics, Nankai University, Tianjin, China. Twenty eight invited speakers from ten countries and areas worldwide gave their lectures at the conference.

  7. Blood volume measurement with indocyanine green pulse spectrophotometry: dose and site of dye administration

    NARCIS (Netherlands)

    M.R. Germans; P.C. de Witt Hamer; L.J. van Boven; K.A.H. Zwinderman; G.J. Bouma

    2010-01-01

    (1) To determine the optimal administration site and dose of indocyanine green (ICG) for blood volume measurement using pulse spectrophotometry, (2) to assess the variation in repeated blood volume measurements for patients after subarachnoid hemorrhage and (3) to evaluate the safety and efficacy of

  8. A Study of Number Conservation With Tasks Which Vary in Length, Area and Volume. Final Report.

    Science.gov (United States)

    Taranto, Maria; Mermelstein, Egon

    The objective of this study was an attempt to clarify the nature of number conservation with number conservation tasks using variations in length, area, and volume. According to Piagetian theory, conservation is attained successively for number, length, area, and, finally, volume. It was hypothesized that success on the number conservation tasks…

  9. Archimedes Revisited: A Faster, Better, Cheaper Method of Accurately Measuring the Volume of Small Objects

    Science.gov (United States)

    Hughes, Stephen W.

    2005-01-01

    A little-known method of measuring the volume of small objects based on Archimedes' principle is described, which involves suspending an object in a water-filled container placed on electronic scales. The suspension technique is a variation on the hydrostatic weighing technique used for measuring volume. The suspension method was compared with two…

  10. Genetic analysis of environmental variation

    NARCIS (Netherlands)

    Hill, W.G.; Mulder, H.A.

    2010-01-01

    Environmental variation (VE) in a quantitative trait – variation in phenotype that cannot be explained by genetic variation or identifiable genetic differences – can be regarded as being under some degree of genetic control. Such variation may be either between repeated expressions of the same trait

  11. Genetic analysis of environmental variation

    NARCIS (Netherlands)

    Hill, W.G.; Mulder, H.A.

    2010-01-01

    Environmental variation (VE) in a quantitative trait – variation in phenotype that cannot be explained by genetic variation or identifiable genetic differences – can be regarded as being under some degree of genetic control. Such variation may be either between repeated expressions of the same trait

  12. Environmental Report 1996, Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Harrach, R.J.

    1996-01-01

    This is Volume 2 of the Lawrence Livermore National Laboratory`s (LLNL`s) annual Environmental Report 1996, prepared for the US Department of Energy. Volume 2 supports Volume 1 summary data and is essentially a detailed data report that provides individual data points, where applicable. Volume 2 includes information on monitoring of air, air effluents, sewerable water, surface water, ground water, soil and sediment, vegetation and foodstuff, environmental radiation, and quality assurance.

  13. A phase-space model for Pleistocene ice volume

    CERN Document Server

    Imbrie, John Z; Lisiecki, Lorraine E

    2011-01-01

    We present a phase-space model that simulates Pleistocene ice volume changes based on Earth's orbital parameters. Terminations in the model are triggered by a combination of ice volume and orbital forcing and agree well with age estimates for Late Pleistocene terminations. The average phase at which model terminations begin is approximately 90 +/- 90 degrees before the maxima in all three orbital cycles. The large variability in phase is likely caused by interactions between the three cycles and ice volume. Unlike previous ice volume models, this model produces an orbitally driven increase in 100-kyr power during the mid-Pleistocene transition without any change in model parameters. This supports the hypothesis that Pleistocene variations in the 100-kyr power of glacial cycles could be caused, at least in part, by changes in Earth's orbital parameters, such as amplitude modulation of the 100-kyr eccentricity cycle, rather than changes within the climate system.

  14. Thermodynamic analysis of a Stirling engine including regenerator dead volume

    Energy Technology Data Exchange (ETDEWEB)

    Puech, Pascal; Tishkova, Victoria [Universite de Toulouse, UPS, CNRS, CEMES, 29 rue Jeanne Marvig, F-31055 Toulouse (France)

    2011-02-15

    This paper provides a theoretical investigation on the thermodynamic analysis of a Stirling engine with linear and sinusoidal variations of the volume. The regenerator in a Stirling engine is an internal heat exchanger allowing to reach high efficiency. We used an isothermal model to analyse the net work and the heat stored in the regenerator during a complete cycle. We show that the engine efficiency with perfect regeneration doesn't depend on the regenerator dead volume but this dead volume strongly amplifies the imperfect regeneration effect. An analytical expression to estimate the improvement due to the regenerator has been proposed including the combined effects of dead volume and imperfect regeneration. This could be used at the very preliminary stage of the engine design process. (author)

  15. REFLECTION AND REFRACTION, VOLUME 2.

    Science.gov (United States)

    KLAUS, DAVID J.; AND OTHERS

    THIS VOLUME 2 OF A TWO-VOLUME SET PROVIDES AUTOINSTRUCTION IN PHYSICS. THE UNITS COVERED IN THIS VOLUME ARE (1) REFLECTION OF LIGHT, (2) PHOTOMETRY, (3) POLARIZATION, (4) REFRACTION OF LIGHT, (5) SNELL'S LAW, (6) LENSES, FOCUS, AND FOCAL POINTS, (7) IMAGE FORMATION, AND (8) ABERRATIONS, THE EYE, AND MAGNIFICATION. THE INTRODUCTION AND UNITS ON…

  16. Calculus Students' Understanding of Volume

    Science.gov (United States)

    Dorko, Allison; Speer, Natasha M.

    2013-01-01

    Researchers have documented difficulties that elementary school students have in understanding volume. Despite its importance in higher mathematics, we know little about college students' understanding of volume. This study investigated calculus students' understanding of volume. Clinical interview transcripts and written responses to volume…

  17. On functions of bounded variation

    OpenAIRE

    Aistleitner, Christoph; Pausinger, Florian; Svane, Anne Marie; Tichy, Robert F.

    2015-01-01

    The recently introduced concept of $\\mathcal{D}$-variation unifies previous concepts of variation of multivariate functions. In this paper, we give an affirmative answer to the open question from Pausinger \\& Svane (J. Complexity, 2014) whether every function of bounded Hardy--Krause variation is Borel measurable and has bounded $\\mathcal{D}$-variation. Moreover, we show that the space of functions of bounded $\\mathcal{D}$-variation can be turned into a commutative Banach algebra.

  18. Rainfall variation by geostatistical interpolation method

    Directory of Open Access Journals (Sweden)

    Glauber Epifanio Loureiro

    2013-08-01

    Full Text Available This article analyses the variation of rainfall in the Tocantins-Araguaia hydrographic region in the last two decades, based upon the rain gauge stations of the ANA (Brazilian National Water Agency HidroWeb database for the years 1983, 1993 and 2003. The information was systemized and treated with Hydrologic methods such as method of contour and interpolation for ordinary kriging. The treatment considered the consistency of the data, the density of the space distribution of the stations and the periods of study. The results demonstrated that the total volume of water precipitated annually did not change significantly in the 20 years analyzed. However, a significant variation occurred in its spatial distribution. By analyzing the isohyet it was shown that there is a displacement of the precipitation at Tocantins Baixo (TOB of approximately 10% of the total precipitated volume. This displacement can be caused by global change, by anthropogenic activities or by regional natural phenomena. However, this paper does not explore possible causes of the displacement.

  19. Human immune system variation.

    Science.gov (United States)

    Brodin, Petter; Davis, Mark M

    2017-01-01

    The human immune system is highly variable between individuals but relatively stable over time within a given person. Recent conceptual and technological advances have enabled systems immunology analyses, which reveal the composition of immune cells and proteins in populations of healthy individuals. The range of variation and some specific influences that shape an individual's immune system is now becoming clearer. Human immune systems vary as a consequence of heritable and non-heritable influences, but symbiotic and pathogenic microbes and other non-heritable influences explain most of this variation. Understanding when and how such influences shape the human immune system is key for defining metrics of immunological health and understanding the risk of immune-mediated and infectious diseases.

  20. Volumes and surface areas of pendular rings

    Science.gov (United States)

    Rose, W.

    1958-01-01

    A packing of spheres is taken as a suitable model of porous media. The packing may be regular and the sphere size may be uniform, but in general, both should be random. Approximations are developed to give the volumes and surface areas of pendular rings that exist at points of sphere contact. From these, the total free volume and interfacial specific surface area are derived as expressive of the textural character of the packing. It was found that the log-log plot of volumes and surface areas of pendular rings vary linearly with the angle made by the line joining the sphere centers and the line from the center of the largest sphere to the closest edge of the pendular ring. The relationship, moreover, was found not to be very sensitive to variation in the size ratio of the spheres in contact. It also was found that the addition of pendular ring material to various sphere packings results in an unexpected decrease in the surface area of the boundaries that confine the resulting pore space. ?? 1958 The American Institute of Physics.

  1. Volume of an Industrial Autoclave

    Directory of Open Access Journals (Sweden)

    Nicholas Madaffari

    2010-01-01

    Full Text Available We were able to determine the volume of an industrial autoclave sterilization tank using a technique learned in calculus. By measuring the dimensions of the tank and roughly estimating the equation of curvature at the ends of the tank, we were able to revolve half of the end of the tank around the x axis to get its fluid volume. Adding the two volumes of the ends and the volume of the cylindrical portion on the tank yielded the total volume.

  2. Lake volume monitoring from space

    Science.gov (United States)

    Crétaux, Jean-Francois; Abarca Del Rio, Rodrigo; Berge-Nguyen, Muriel; Arsen, Adalbert; Drolon, Vanessa; Maisongrande, Philippe

    2016-04-01

    Lakes are integrator of environmental changes occurring at regional to global scale and present a high variety of behaviors on a variety of time scales (cyclic and secular) depending on the climate conditions and their morphology. In addition their crucial importance as water stocks and retaining, given the significant environment changes occurring worldwide at many anthropocentric levels, has increased the necessity of monitoring all its morphodynamics characteristics, say water level, surface (water contour) and volume. The satellite altimetry and satellite imagery together are now widely used for the calculation of lakes and reservoirs water storage changes worldwide. However strategies and algorithms to calculate these characteristics are not straightforward and need development of specific approaches. We intend to present a review of some of these methodologies by using the lakes over the Tibetan Plateau to illustrate some critical aspects and issues (technical and scientific) linked with the survey of climate changes impacts on surface waters from remote sensing data. Many authors have measured water variations using the short period of remote sensing measurements available, although time series are probably too short to lead to definitive conclusions to link these results directly with the framework of climate changes. Indeed, many processes beyond the observations are still uncertain, for example the influence of morphology of the lakes. The time response for a lake to reach new state of equilibrium is one of the key aspects often neglected in the current literature. Observations over long period of time, therein maintaining a constellation of comprehensive and complementary satellite missions with a continuity of services over decades, especially when ground gauges network is too limited is therefore a necessity. In addition, the design of future satellite missions with new instrumental concepts (e.g. SAR, SARin, Ka band altimetry, Ka interferometry) is

  3. A STUDY ON MORPHOMETRIC MEASUREMENT OF VOLUME OF ACETABULUM

    Directory of Open Access Journals (Sweden)

    Leena Khobragade,

    2014-09-01

    Full Text Available Background: Hip joint represents an unique functional unit and has complex biomechanical construction. In today’s era where total hip replacement surgeries have made their way it has become imperative for the anatomists to know the variations in acetabular dimensions. Reconstruction of acetabulum in patients with significant acetabular bone deficiency remains a challenge. Hence the present study was carried out with the aim to study the morphometric measurement of volume of acetabulum in both the sexes. Materials and Methods: Material of the study consisted of 110 human hip bones (60 males and 50 females. Volume of Acetabulum (VA was measured on these hip bones on both the sides. Statistical analysis was done using SPSS (Statistical Package for the Social Sciences version 11 and Microsoft Excel 2007. Results: The mean volume of acetabulum in male was 23.13 ml and female was 17.88 ml. The mean volume of acetabulum on right side was 20.55 ml and left side was 20.91 ml. Volume of the acetabulum was greater in males as compared to females and the differences were statistically significant. Volume was greater on the left side as compared to the right side but the difference was statistically non significant. Discussion: Analysing the differences on human acetabulum is helpful in understanding not only morphological but also medicolegal aspects. Conclusion: Volume of the acetabulum was greater in males as compared to females.

  4. Light Propagation Volumes

    OpenAIRE

    Mikulica, Tomáš

    2016-01-01

    Cílem diplomové práce je popsat různé metody výpočtu globálního osvětlení scény včetně techniky Light Propagation Volumes. Pro tuto metodu jsou podrobně popsány všechny tři kroky výpočtu: injekce, propagace a vykreslení. Dále je navrženo několik vlastních rozšíření zlepšující grafickou kvalitu metody. Části návrhu a implementace jsou zaměřeny na popis scény, zobrazovacího systému, tvorby stínů, implementace metody Light Propagation Volumes a navržených rozšíření. Práci uzavírá měření, porovná...

  5. [Advances in the research of fluid resuscitation for burn shock].

    Science.gov (United States)

    Huan, Jing-ning

    2013-06-01

    The aim of fluid resuscitation is to restore tissue perfusion, ameliorate cellular injury, increase tissue perfusion and oxygenation, and improve end-organ functions. Many researches in the field of fluid resuscitation strategy have been made in the last decade, but vigorous debate on optimal method of resuscitation still exists. The hypotensive resuscitation strategy is particularly applicable in patients with uncontrollable hemorrhage, whereas, it is uncertain whether the theory could be used in burn shock management. Resuscitation using both colloid and crystalloid has a better outcome in treating extensive burns and septic shock. Caution should be exercised when using higher concentrations of artificial colloid and lactated Ringer's solution, of which some adverse effects have been observed. Along with the increasing use of novel hemodynamics monitoring in intensive care, parameters including stroke volume variation (SVV), intrathoracic blood volume index (ITBVI), and cardiac index (CI) have been examined as indexes of resuscitation endpoint. However, further studies should be made when applying SVV, ITBVI, and CI in guiding fluid resuscitation in burns.

  6. Advances in the research of fluid resuscitation for burn shock%烧伤休克液体复苏研究进展

    Institute of Scientific and Technical Information of China (English)

    郇京宁

    2013-01-01

    The aim of fluid resuscitation is to restore tissue perfusion,ameliorate cellular injury,increase tissue perfusion and oxygenation,and improve end-organ functions.Many researches in the field of fluid resuscitation strategy have been made in the last decade,but vigorous debate on optimal method of resuscitation still exists.The hypotensive resuscitation strategy is particularly applicable in patients with uncontrollable hemorrhage,whereas,it is uncertain whether the theory could be used in burn shock management.Resuscitation using both colloid and crystalloid has a better outcome in treating extensive burns and septic shock.Caution should be exercised when using higher concentrations of artificial colloid and lactated Ringer's solution,of which some adverse effects have been observed.Along with the increasing use of novel hemodynamics monitoring in intensive care,parameters including stroke volume variation (SVV),intrathoracic blood volume index (ITBVI),and cardiac index (CI) have been examined as indexes of resuscitation endpoint.However,further studies should be made when applying SVV,ITBVI,and CI in guiding fluid resuscitation in burns.

  7. Variational principles of continuum mechanics. Vol. 1. Fundamentals

    Energy Technology Data Exchange (ETDEWEB)

    Berdichevsky, Victor L. [Wayne State Univ., Detroit, MI (United States). Dept. of Mechanical Engineering

    2009-07-01

    The book reviews the two features of the variational approach: its use as a universal tool to describe physical phenomena and as a source for qualitative and quantitative methods of studying particular problems. Berdichevsky's work differs from other books on the subject in focusing mostly on the physical origin of variational principles as well as establishing their interrelations. For example, the Gibbs principles appear as a consequence of the Einstein formula for thermodynamic fluctuations rather than as the first principles of the theory of thermodynamic equilibrium. Mathematical issues are considered as long as they shed light on the physical outcomes and/or provide a useful technique for the direct study of variational problems. In addition, a thorough account of variational principles discovered in various branches of continuum mechanics is given. In this book, the first volume, the author covers the variational principles for systems with a finite number of degrees of freedom; the variational principles of thermodynamics; the basics of continuum mechanics; the variational principles for classical models of continuum mechanics, such as elastic and plastic bodies, and ideal and viscous fluids; and direct methods of calculus of variations. (orig.)

  8. Comparison of medical of volume measurement of the prostate by transrectal ultrasound: Experiment with jelly models

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Jeong Yeon; Lee, Hak Jong; Kim, Sung Hyun [Samsung Seoul Hospital, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Kim, Seung Hyup [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2002-03-15

    To evaluate the accuracy of measuring the volume of the prostate using the prolate ellipsoid volume calculation method (antero-posterior (AP) diameter X length X width X {pi}6) when the antero-posterior diameter of the prostate was measured on midsagittal (sagittal volume) and axial plane (axial volume).The devil's tongue jelly was used for the creation of ultrasound model of the prostate (volume: 15-40 cc) by cutting and shaping the surface. The volume in 10 prostatic models and 30 patients was measured and calculated. First, the AP diameter and length of the prostate models in midsagittal plane, and the height and width of the models in axial plane were measured for 3 times. The volume was calculated in two ways, one using the AP diameter an midsagittal plane and the other using the AP diameter in axial plane. The true volume of the model was measured using mess cylinder. The calculated volume and true volume were compared, and the accuracy of two method of measuring the prostatic volume was evaluated by Friedman test. The intraobserver variation was evaluated by General Linear Model, Repeated Measure. The reproducibility was evaluated by Cronbach's {alpha}. In vivo study was also performed in 30 patients. The prostate volume was calculated in the same manner. These volume data were analyzed by statistical method, and the intraobeserver variation was evaluated. While there was a statistically significant difference between the sagittal and true volume of the models, there was no statistical significant difference between the axial and true volumes. There was no significant intraobserver variation between both methods. The reproducibility was high in both methods with Cronbach's {alpha} of 0.977 and 0.942. The sagittal volume was larger than the axial volume in 30 patients with a statistically significant difference. There was no significant intraobserver variation in both methods. The reproducibility was high in both methods Cronbach's {alpha

  9. Pad-weighing test performed with standardized bladder volume

    DEFF Research Database (Denmark)

    Lose, G; Rosenkilde, P; Gammelgaard, J

    1988-01-01

    with a standardized bladder volume (50% of the cystometric bladder capacity). Twenty-five female patients with stress or mixed incontinence underwent two separate tests. Test-retest results were highly correlated (r = 0.97, p less than 0.001). Nonetheless, analysis of test-retest differences revealed a variation up...... to +/- 24 g between two tests. It is concluded that this setup (i.e., standardized bladder volume) of the one-hour pad-weighing test allows for a more reliable assessment of urinary incontinence for quantitative purposes....

  10. An improved variational method

    Institute of Scientific and Technical Information of China (English)

    ZENG Zhuo-Quan; SHEN Peng-Nian; DING Yi-Bing

    2009-01-01

    In order to improve the unitarity of the S-matrix, an improved variational formulism is derived by proposing new generating functionals and adopting proper asymptotic boundary conditions for trial relative wave functions. The formulas with the weighted line-column balance for the single-channel and multi-channel scatterings, where the non-central interaction is implicitly considered, are presented. A numerical check is performed with a soluble model in a four coupled channel scattering problem. The result shows that the high accuracy and the unitarity of the S-matrix are reached.

  11. Taking Stock of Regulatory Variation.

    Science.gov (United States)

    Maurano, Matthew T; Stamatoyannopoulos, John A

    2015-07-29

    Three recent studies measure individual variation in regulatory DNA accessibility. What do they tell us about the prospects of assessing variation in single cells and across populations? Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Lexical Variation in Akokoid

    Directory of Open Access Journals (Sweden)

    Fádorò Jacob Oludare

    2014-07-01

    Full Text Available Language contact among Akokoid, Yoruboid and Edoid has resulted in extensive borrowing from Yoruboid and Edoid to Akokoid. Thus, the speech forms subsumed under Akokoid exhibit lexical items which are similar to Yoruboid and Edoid. To the best of our knowledge, no other scholarly work has addressed the concept ‘lexical variation in these speech forms, hence, the need for this present effort. Twenty lexical items were carefully selected for analysis in this paper. Data were elicited from 34 informants who are competent speakers of Akokoid. Apart from the linguistic data, these informants, including  traditional rulers, supplied us with historical facts about the migration patterns of the progenitors of Akokoid. The historical facts coupled with the linguistic data helped us to arrive at the conclusion that some of the words used in contemporary Akokoid found their way into Akokoid as a result of the contact between Akokoid and their neighbours, Yoruboid and Edoid.Keywords: Akokoid, Language Contact, Lexical Variation, Yoruboid, Edoid

  13. Multifunctions of bounded variation

    Science.gov (United States)

    Vinter, R. B.

    2016-02-01

    Consider control systems described by a differential equation with a control term or, more generally, by a differential inclusion with velocity set F (t , x). Certain properties of state trajectories can be derived when it is assumed that F (t , x) is merely measurable w.r.t. the time variable t. But sometimes a refined analysis requires the imposition of stronger hypotheses regarding the time dependence. Stronger forms of necessary conditions for minimizing state trajectories can be derived, for example, when F (t , x) is Lipschitz continuous w.r.t. time. It has recently become apparent that significant addition properties of state trajectories can still be derived, when the Lipschitz continuity hypothesis is replaced by the weaker requirement that F (t , x) has bounded variation w.r.t. time. This paper introduces a new concept of multifunctions F (t , x) that have bounded variation w.r.t. time near a given state trajectory, of special relevance to control. We provide an application to sensitivity analysis.

  14. Gauging Variational Inference

    Energy Technology Data Exchange (ETDEWEB)

    Chertkov, Michael [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ahn, Sungsoo [Korea Advanced Inst. Science and Technology (KAIST), Daejeon (Korea, Republic of); Shin, Jinwoo [Korea Advanced Inst. Science and Technology (KAIST), Daejeon (Korea, Republic of)

    2017-05-25

    Computing partition function is the most important statistical inference task arising in applications of Graphical Models (GM). Since it is computationally intractable, approximate methods have been used to resolve the issue in practice, where meanfield (MF) and belief propagation (BP) are arguably the most popular and successful approaches of a variational type. In this paper, we propose two new variational schemes, coined Gauged-MF (G-MF) and Gauged-BP (G-BP), improving MF and BP, respectively. Both provide lower bounds for the partition function by utilizing the so-called gauge transformation which modifies factors of GM while keeping the partition function invariant. Moreover, we prove that both G-MF and G-BP are exact for GMs with a single loop of a special structure, even though the bare MF and BP perform badly in this case. Our extensive experiments, on complete GMs of relatively small size and on large GM (up-to 300 variables) confirm that the newly proposed algorithms outperform and generalize MF and BP.

  15. Variational Theory for Chandrasekharaiah Thermopizoelectricity

    Institute of Scientific and Technical Information of China (English)

    JiHuanHE

    1999-01-01

    Via the semi-inverse method of establishing generalized variational principle for physical problems,a classical variational model(non Gurtin-type and not involving convolutions) for Chandrasekharaiah thermopiezoelectricity is established directly from the governing equations.The present theory aims at providing a more complete theoretical basis for the variational-based finite element applications and variational-based meshless method(element-free method).

  16. Cardiothoracic ratio on chest radiograph in pediatric heart disease: How does it correlate with heart volumes at magnetic resonance imaging?

    Energy Technology Data Exchange (ETDEWEB)

    Grotenhuis, Heynric B. [The University of Toronto, Division of Cardiology, Department of Paediatrics, The Labatt Family Heart Centre, The Hospital for Sick Children, Toronto (Canada); Zhou, Cheng; Isaac, Kathryn V. [The University of Toronto, Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto (Canada); Tomlinson, George [University of Toronto, Department of Medicine, Toronto General Hospital and Mt. Sinai Hospital, Toronto (Canada); Seed, Mike; Grosse-Wortmann, Lars; Yoo, Shi-Joon [The University of Toronto, Division of Cardiology, Department of Paediatrics, The Labatt Family Heart Centre, The Hospital for Sick Children, Toronto (Canada); The University of Toronto, Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto (Canada)

    2015-10-15

    The cardiothoracic ratio by chest radiograph is widely used as a marker of cardiac size. The purpose of this study is to correlate cardiothoracic ratio and cardiac volumes as measured by cardiovascular magnetic resonance (MR) in common structural and myopathic heart disease with increased cardiac size due to volume overload or hypertrophy. A retrospective single center study was performed in all patients between 2007 and 2013 with repaired tetralogy of Fallot (TOF), aortic regurgitation, isolated left-to-right shunt and hypertrophic cardiomyopathy (HCM) who underwent cardiovascular MR and chest radiograph within 6 months of each other. Cardiothoracic ratios by chest radiograph (frontal and lateral) were compared to cardiac volumes (indexed for body surface area) by cardiovascular MR. One hundred twenty-seven patients (mean age: 11.2 ± 5.5 years) were included in this study (76 with TOF, 23 with isolated left-to-right shunt, 16 with aortic regurgitation and 12 with HCM). Frontal cardiothoracic ratio of all groups correlated with indexed right ventricular (RV) end-diastolic volume (EDVI) (r = 0.40, P < 0.01) and indexed total heart volume (THVI) (r = 0.27, P < 0.01). In TOF patients, frontal cardiothoracic ratio correlated with RVEDVI (r = 0.34, P < 0.01; coefficient of variation = 27.6%), indexed RV end-systolic volume (ESVI) (r = 0.44, P < 0.01; coefficient of variation = 33.3%) and THVI (r = 0.35, P < 0.01; coefficient of variation = 19.6%), although RV volumes and THVI showed widespread variation given the high coefficients of variation. In patients with aortic regurgitation, frontal cardiothoracic ratio correlated with left ventricular (LV) EDVI (r = 0.50, P = 0.047), but not with THVI and aortic regurgitant fraction, and widespread variation for LV EDVI (coefficient of variation = 19.2%), LV ESVI (coefficient of variation = 32.5%) and THVI (coefficient of variation = 13.6%) was also observed. Frontal cardiothoracic ratio was not correlated with cardiac volumes

  17. 3D MRI volume sizing of knee meniscus cartilage.

    Science.gov (United States)

    Stone, K R; Stoller, D W; Irving, S G; Elmquist, C; Gildengorin, G

    1994-12-01

    Meniscal replacement by allograft and meniscal regeneration through collagen meniscal scaffolds have been recently reported. To evaluate the effectiveness of a replaced or regrown meniscal cartilage, a method for measuring the size and function of the regenerated tissue in vivo is required. To solve this problem, we developed and evaluated a magnetic resonance imaging (MRI) technique to measure the volume of meniscal tissues. Twenty-one intact fresh cadaver knees were evaluated and scanned with MRI for meniscal volume sizing. The sizing sequence was repeated six times for each of 21 lateral and 12 medial menisci. The menisci were then excised and measured by water volume displacement. Each volume displacement measurement was repeated six times. The MRI technique employed to measure the volume of the menisci was shown to correspond to that of the standard measure of volume and was just as precise. However, the MRI technique consistently underestimated the actual volume. The average of the coefficient of variation for lateral volumes was 0.04 and 0.05 for the water and the MRI measurements, respectively. For medial measurements it was 0.04 and 0.06. The correlation for the lateral menisci was r = 0.45 (p = 0.04) and for the medial menisci it was r = 0.57 (p = 0.05). We conclude that 3D MRI is precise and repeatable but not accurate when used to measure meniscal volume in vivo and therefore may only be useful for evaluating changes in meniscal allografts and meniscal regeneration templates over time.

  18. 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....

  19. Determination of fiber volume in graphite/epoxy materials using computer image analysis

    Science.gov (United States)

    Viens, Michael J.

    1990-01-01

    The fiber volume of graphite/epoxy specimens was determined by analyzing optical images of cross sectioned specimens using image analysis software. Test specimens were mounted and polished using standard metallographic techniques and examined at 1000 times magnification. Fiber volume determined using the optical imaging agreed well with values determined using the standard acid digestion technique. The results were found to agree within 5 percent over a fiber volume range of 45 to 70 percent. The error observed is believed to arise from fiber volume variations within the graphite/epoxy panels themselves. The determination of ply orientation using image analysis techniques is also addressed.

  20. Design of Finite Element Tools for Coupled Surface and Volume Meshes

    Institute of Scientific and Technical Information of China (English)

    Daniel K(o)ster; Oliver Kriessl; Kunibert G. Siebert

    2008-01-01

    Many problems with underlying variational structure involve a coupling of volume with surface effects. A straight-forward approach in a finite element discretization is to make use of the surface triangulation that is naturally induced by the volume triangulation. In an adaptive method one wants to facilitate "matching" local mesh modifications, i.e., local refinement and/or coarsening, of volume and surface mesh with standard tools such that the surface grid is always induced by the volume grid. We describe the concepts behind this approach for bisectional refinement and describe new tools incorporated in the finite element toolbox ALBERTA. We also present several important applications of the mesh coupling.

  1. Vaginal Motion and Bladder and Rectal Volumes During Pelvic Intensity-Modulated Radiation Therapy After Hysterectomy

    Energy Technology Data Exchange (ETDEWEB)

    Jhingran, Anuja, E-mail: ajhingra@mdanderson.org [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Salehpour, Mohammad [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Sam, Marianne; Levy, Larry; Eifel, Patricia J. [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States)

    2012-01-01

    Purpose: To evaluate variations in bladder and rectal volume and the position of the vaginal vault during a 5-week course of pelvic intensity-modulated radiation therapy (IMRT) after hysterectomy. Methods and Materials: Twenty-four patients were instructed how to fill their bladders before simulation and treatment. These patients underwent computed tomography simulations with full and empty bladders and then underwent rescanning twice weekly during IMRT; patients were asked to have full bladder for treatment. Bladder and rectal volumes and the positions of vaginal fiducial markers were determined, and changes in volume and position were calculated. Results: The mean full and empty bladder volumes at simulation were 480 cc (range, 122-1,052) and 155 cc (range, 49-371), respectively. Bladder volumes varied widely during IMRT: the median difference between the maximum and minimum volumes was 247 cc (range, 96-585). Variations in rectal volume during IMRT were less pronounced. For the 16 patients with vaginal fiducial markers in place throughout IMRT, the median maximum movement of the markers during IMRT was 0.59 cm in the right-left direction (range, 0-0.9), 1.46 cm in the anterior-posterior direction (range, 0.8-2.79), and 1.2 cm in the superior-inferior direction (range, 0.6-2.1). Large variations in rectal or bladder volume frequently correlated with significant displacement of the vaginal apex. Conclusion: Although treatment with a full bladder is usually preferred because of greater sparing of small bowel, our data demonstrate that even with detailed instruction, patients are unable to maintain consistent bladder filling. Variations in organ position during IMRT can result in marked changes in the position of the target volume and the volume of small bowel exposed to high doses of radiation.

  2. Cosmological Measures without Volume Weighting

    CERN Document Server

    Page, Don N

    2008-01-01

    Many cosmologists (myself included) have advocated volume weighting for the cosmological measure problem, weighting spatial hypersurfaces by their volume. However, this often leads to the Boltzmann brain problem, that almost all observations would be by momentary Boltzmann brains that arise very briefly as quantum fluctuations in the late universe when it has expanded to a huge size, so that our observations (too ordered for Boltzmann brains) would be highly atypical and unlikely. Here it is suggested that volume weighting may be a mistake. Volume averaging is advocated as an alternative. One consequence would be a loss of the argument for eternal inflation.

  3. Calculus of variations and nonlinear partial differential equations

    CERN Document Server

    Marcellini, Paolo

    2008-01-01

    This volume provides the texts of lectures given by L. Ambrosio, L. Caffarelli, M. Crandall, L.C. Evans, N. Fusco at the Summer course held in Cetraro (Italy) in 2005. These are introductory reports on current research by world leaders in the fields of calculus of variations and partial differential equations. The topics discussed are transport equations for nonsmooth vector fields, homogenization, viscosity methods for the infinite Laplacian, weak KAM theory and geometrical aspects of symmetrization. A historical overview of all CIME courses on the calculus of variations and partial differential equations is contributed by Elvira Mascolo.

  4. Heliophysics 3 Volume Set

    Science.gov (United States)

    Schrijver, Carolus J.; Siscoe, George L.

    2010-11-01

    Volume 1: Preface; 1. Prologue Carolus J. Schrijver and George L. Siscoe; 2. Introduction to heliophysics Thomas J. Bogdan; 3. Creation and destruction of magnetic field Matthias Rempel; 4. Magnetic field topology Dana W. Longcope; 5. Magnetic reconnection Terry G. Forbes; 6. Structures of the magnetic field Mark B. Moldwin, George L. Siscoe and Carolus J. Schrijver; 7. Turbulence in space plasmas Charles W. Smith; 8. The solar atmosphere Viggo H. Hansteen; 9. Stellar winds and magnetic fields Viggo H. Hansteen; 10. Fundamentals of planetary magnetospheres Vytenis M. Vasyliūnas; 11. Solar-wind magnetosphere coupling: an MHD perspective Frank R. Toffoletto and George L. Siscoe; 12. On the ionosphere and chromosphere Tim Fuller-Rowell and Carolus J. Schrijver; 13. Comparative planetary environments Frances Bagenal; Bibliography; Index. Volume 2: Preface; 1. Perspective on heliophysics George L. Siscoe and Carolus J. Schrijver; 2. Introduction to space storms and radiation Sten Odenwald; 3. In-situ detection of energetic particles George Gloeckler; 4. Radiative signatures of energetic particles Tim Bastian; 5. Observations of solar and stellar eruptions, flares, and jets Hugh Hudson; 6. Models of coronal mass ejections and flares Terry Forbes; 7. Shocks in heliophysics Merav Opher; 8. Particle acceleration in shocks Dietmar Krauss-Varban; 9. Energetic particle transport Joe Giacalone; 10. Energy conversion in planetary magnetospheres Vytenis Vasyliūnas; 11. Energization of trapped particles Janet Green; 12. Flares, CMEs, and atmospheric responses Tim Fuller-Rowell and Stanley C. Solomon; 13. Energetic particles and manned spaceflight 358 Stephen Guetersloh and Neal Zapp; 14. Energetic particles and technology Alan Tribble; Appendix I. Authors and editors; List of illustrations; List of tables; Bibliography; Index. Volume 3: Preface; 1. Interconnectedness in heliophysics Carolus J. Schrijver and George L. Siscoe; 2. Long-term evolution of magnetic activity of Sun

  5. Volume and Surface-Enhanced Volume Negative Ion Sources

    CERN Document Server

    Stockli, M P

    2013-01-01

    H- volume sources and, especially, caesiated H- volume sources are important ion sources for generating high-intensity proton beams, which then in turn generate large quantities of other particles. This chapter discusses the physics and technology of the volume production and the caesium-enhanced (surface) production of H- ions. Starting with Bacal's discovery of the H- volume production, the chapter briefly recounts the development of some H- sources, which capitalized on this process to significantly increase the production of H- beams. Another significant increase was achieved in the 1990s by adding caesiated surfaces to supplement the volume-produced ions with surface-produced ions, as illustrated with other H- sources. Finally, the focus turns to some of the experience gained when such a source was successfully ramped up in H- output and in duty factor to support the generation of 1 MW proton beams for the Spallation Neutron Source.

  6. Spatial Variations of Fundamental Constants

    CERN Document Server

    Barrow, John D; Barrow, John D.; Toole, Chris O'

    1999-01-01

    We show that observational limits on the possible time variation of constants of Nature are significantly affected by allowing for both space and time variation. Bekenstein's generalisation of Maxwell's equations to allow for cosmological variation of $alpha$ is investigated in a universe containing spherically symmetric inhomogeneities. The time variation of $alpha$ is determined by the local matter density and hence limits obtained in high-density geophysical enviroments are far more constraining than those obtained at high redshift. This new feature is expected to be a property of a wide class of theories for the variation of constants.

  7. Development of a balloon volume sensor for pulsating balloon catheters.

    Science.gov (United States)

    Nolan, Timothy D C; Hattler, Brack G; Federspiel, William J

    2004-01-01

    Helium pulsed balloons are integral components of several cardiovascular devices, including intraaortic balloon pumps (IABP) and a novel intravenous respiratory support catheter. Effective use of these devices clinically requires full inflation and deflation of the balloon, and improper operating conditions that lead to balloon under-inflation can potentially reduce respiratory or cardiac support provided to the patient. The goal of the present study was to extend basic spirographic techniques to develop a system to dynamically measure balloon volumes suitable for use in rapidly pulsating balloon catheters. The dynamic balloon volume sensor system (DBVSS) developed here used hot wire anemometry to measure helium flow in the drive line from console to catheter and integrated the flow to determine the volume delivered in each balloon pulsation. An important component of the DBVSS was an algorithm to automatically detect and adjust flow signals and measured balloon volumes in the presence of gas composition changes that arise from helium leaks occurring in these systems. The DBVSS was capable of measuring balloon volumes within 5-10% of actual balloon volumes over a broad range of operating conditions relevant to IABP and the respiratory support catheter. This includes variations in helium concentration from 70-100%, pulsation frequencies from 120-480 beats per minute, and simulated clinical conditions of reduced balloon filling caused by constricted vessels, increased driveline, or catheter resistance.

  8. Reliability of brain volume measurements: a test-retest dataset.

    Science.gov (United States)

    Maclaren, Julian; Han, Zhaoying; Vos, Sjoerd B; Fischbein, Nancy; Bammer, Roland

    2014-01-01

    Evaluation of neurodegenerative disease progression may be assisted by quantification of the volume of structures in the human brain using magnetic resonance imaging (MRI). Automated segmentation software has improved the feasibility of this approach, but often the reliability of measurements is uncertain. We have established a unique dataset to assess the repeatability of brain segmentation and analysis methods. We acquired 120 T1-weighted volumes from 3 subjects (40 volumes/subject) in 20 sessions spanning 31 days, using the protocol recommended by the Alzheimer's Disease Neuroimaging Initiative (ADNI). Each subject was scanned twice within each session, with repositioning between the two scans, allowing determination of test-retest reliability both within a single session (intra-session) and from day to day (inter-session). To demonstrate the application of the dataset, all 3D volumes were processed using FreeSurfer v5.1. The coefficient of variation of volumetric measurements was between 1.6% (caudate) and 6.1% (thalamus). Inter-session variability exceeded intra-session variability for lateral ventricle volume (P<0.0001), indicating that ventricle volume in the subjects varied between days.

  9. Variations on tremor parameters

    Science.gov (United States)

    Boose, A.; Jentgens, Ch.; Spieker, S.; Dichgans, J.

    1995-03-01

    This paper describes our analysis procedure for long-term tremor EMG recordings, as well as three examples of applications. The description of the method focuses on how characteristics of the tremor (e.g. frequency, intensity, agonist-antagonist interaction) can be defined and calculated based on surface EMG data. The resulting quantitative characteristics are called ``tremor parameters.'' We discuss sinusoidally modulated, band-limited white noise as a model for pathological tremor-EMG, and show how the basic parameters can be extracted from this class of signals. The method is then applied to (1) estimate tremor severity in clinical studies, (2) quantify agonist-antagonist interaction, and (3) investigate the variations of the tremor parameters using simple methods from time-series analysis.

  10. Variational principles of continuum mechanics. Vol. 2. Applications

    Energy Technology Data Exchange (ETDEWEB)

    Berdichevsky, Victor L. [Wayne State Univ., Detroit, MI (United States). Dept. of Mechanical Engineering

    2009-07-01

    The book reviews the two features of the variational approach: its use as a universal tool to describe physical phenomena and as a source for qualitative and quantitative methods of studying particular problems. Berdichevsky's work differs from other books on the subject in focusing mostly on the physical origin of variational principles as well as establishing their interrelations. For example, the Gibbs principles appear as a consequence of the Einstein formula for thermodynamic fluctuations rather than as the first principles of the theory of thermodynamic equilibrium. Mathematical issues are considered as long as they shed light on the physical outcomes and/or provide a useful technique for the direct study of variational problems. In addition, a thorough account of variational principles discovered in various branches of continuum mechanics is given. This book, the second volume, describes how the variational approach can be applied to constructing models of continuum media, such as the theory of elastic plates; shells and beams; shallow water theory; heterogeneous mixtures; granular materials; and turbulence. It goes on to apply the variational approach to asymptotical analysis of problems with small parameters, such as the derivation of the theory of elastic plates, shells and beams from three-dimensional elasticity theory; and the basics of homogenization theory. A theory of stochastic variational problems is considered in detail too, along with applications to the homogenization of continua with random microstructures. (orig.)

  11. Crystallization and preliminary X-ray diffraction studies of Seneca Valley virus-001, a new member of the Picornaviridae family.

    Science.gov (United States)

    Venkataraman, Sangita; Reddy, Seshidhar P; Loo, Jackie; Idamakanti, Neeraja; Hallenbeck, Paul L; Reddy, Vijay S

    2008-04-01

    Seneca Valley Virus-001 (SVV-001) is a newly found species in the Picornaviridae family. SVV-001 is the first naturally occurring nonpathogenic picornavirus observed to mediate selective cytotoxicity towards tumor cells with neuroendocrine cancer features. The nonsegmented (+)ssRNA genome of SVV-001 shares closest sequence similarity to the genomes of the members of the Cardiovirus genus. However, based on the distinct characteristics of the genome organization and other biochemical properties, it has been suggested that SVV-001 represents a new genus, namely 'Senecavirus', in the Picornaviridae family. In order to understand the oncolytic properties of SVV-001, the native virus was crystallized using the hanging-drop vapour-diffusion method. The crystals belonged to space group R3, with unit-cell parameters (in the hexagonal setting) a = b = 311.5, c = 1526.4 A. Although the SVV crystals diffracted to better than 2.3 A resolution, the data quality is acceptable [I/sigma(I) > 2.0] to 2.6 A resolution. The unit-cell volume and the locked rotation-function analysis suggest that six particles could be accommodated in the unit cell, with two distinct sets of one third of a particle, each containing 20 protomers, occupying the crystallographic asymmetric unit. (ClinicalTrials.gov identifier NCT00314925)

  12. [Inhibition Function of Dominant-negative Mutant Gene Survivin-D53A to SPC-A1 Lung Adenocarcinoma Xenograft in Nude Mice Models].

    Science.gov (United States)

    Yu, Min; Peng, Xingchen; Lu, You; Huang, Meijuan

    2015-06-01

    Survivin-D53A (SVV-D53A) is a dominant-negative mutant survivin, which represents a potential promising target for cancer gene therapy. The present study was designed to determine whether SVV-D53A plasmid encapsuled by DOTAP: Chol liposome would have the anti-tumor activity against SPC-A1 lung adenocarcinoma, and to detect the possible mechanisms. In our experiment, SPC-A1 cells were transfected in vitro with SVV-D53A plasmid and examined for protein expression by Western blot, then flow cytometric analysis was used to detect apoptosis. SPC-A1 lung adenocarcinoma xenografts were established in vivo in the nude mice, which received the i. v. administrations of SVV-D53A plasmid/liposome complexes. After mice were sacrificed, the paraffin-embedded tumor tissue sections were used for proliferating cell nuclear antigen (PCNA) expression and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Compared with the control group, the mice treated with SVV-D53A plasmid had an obviously reduced tumor volume, with high level of apoptosis and decreased cell proliferation in tumor tissue. The research results proved that the administration of SVV-D53A plasmid resulted in significant inhibition of SPC-A1 cells both in vitro and in vivo. The functional mechanism is that the anti-tumor response causes and induces tumor cell apoptosis.

  13. PDLE: Sustaining Professionalism. Volume 3

    Science.gov (United States)

    Byrd, Patricia, Ed.; Nelson, Gayle, Ed.

    2003-01-01

    This third volume looks at ways that seasoned professionals continue to develop throughout their careers. The text includes descriptive accounts of professionals seeking to enhance their careers while remaining inspired to continue to develop professionally. This volume reveals how personal and professional lives are entwined. It proves that TESOL…

  14. NJP VOLUME 41 NO 2

    African Journals Online (AJOL)

    PROF. EZECHUKWU

    2013-11-24

    Nov 24, 2013 ... sleep. There was also increase in both frequency of uri- nation and volume of urine voided; from1- 2 times to ... phagia, fever, head trauma, chronic cough, weight loss, ... water deprivation at 15Kg. Total volume of urine voided.

  15. Finding related functional neuroimaging volumes

    DEFF Research Database (Denmark)

    Nielsen, Finn Årup; Hansen, Lars Kai

    2004-01-01

    We describe a content-based image retrieval technique for finding related functional neuroimaging experiments by voxelization of sets of stereotactic coordinates in Talairach space, comparing the volumes and reporting related volumes in a sorted list. Voxelization is accomplished by convolving each...

  16. Genetic variation in retinal vascular patterning predicts variation in pial collateral extent and stroke severity

    Science.gov (United States)

    Prabhakar, Pranay; Zhang, Hua; Chen, De; Faber, James E.

    2015-01-01

    The presence of a native collateral circulation in tissues lessens injury in occlusive vascular diseases. However, differences in genetic background cause wide variation in collateral number and diameter in mice, resulting in large variation in protection. Indirect estimates of collateral perfusion suggest wide variation also exists in humans. Unfortunately, methods used to obtain these estimates are invasive and not widely available. We sought to determine if differences in genetic background in mice result in variation in branch-patterning of the retinal arterial circulation, and if these differences predict strain-dependent differences in pial collateral extent and severity of ischemic stroke. Retinal patterning metrics, collateral extent, and infarct volume were obtained for 10 strains known to differ widely in collateral extent. Multivariate regression was conducted and model performance assessed using K-fold cross-validation. Twenty-one metrics varied with strain (placunarity, optimality) predicted collateral number and diameter across 7 regression models, with the best model closely predicting (p<0.0001) number (± 1.2-3.4 collaterals, K-fold R2=0.83-0.98), diameter (± 1.2-1.9μm, R2=0.73-0.88) and infarct volume (± 5.1 mm3, R2=0.85-0.87). These metrics obtained for the middle cerebral artery tree in a subset of the above strains also predicted (p<0.0001) collateral number and diameter and diameter, although with less strength (K-fold R2=0.61-0.78) and 0.60-0.86, respectively). Thus, differences in arterial branch-patterning in the retina and the MCA trees are specified by genetic background and predict variation in collateral extent and stroke severity. If also true in human retina, and since genetic variation in cerebral collaterals extends to other tissues at least in mice, a similar “retinal predictor index” could serve as a non-or minimally invasive biomarker for collateral extent in brain and other tissues. This could aid prediction of severity

  17. Lamb Wave Assessment of Fiber Volume Fraction in Composites

    Science.gov (United States)

    Seale, Michael D.; Smith, Barry T.; Prosser, W. H.; Zalameda, Joseph N.

    1998-01-01

    Among the various techniques available, ultrasonic Lamb waves offer a convenient method of examining composite materials. Since the Lamb wave velocity depends on the elastic properties of a material, an effective tool exists to evaluate composites by measuring the velocity of these waves. Lamb waves can propagate over long distances and are sensitive to the desired in-plane elastic properties of the material. This paper discusses a study in which Lamb waves were used to examine fiber volume fraction variations of approximately 0.40-0.70 in composites. The Lamb wave measurements were compared to fiber volume fractions obtained from acid digestion tests. Additionally, a model to predict the fiber volume fraction from Lamb wave velocity values was evaluated.

  18. Discretized Volumes in Numerical Methods

    CERN Document Server

    Antal, Miklós

    2007-01-01

    We present two techniques novel in numerical methods. The first technique compiles the domain of the numerical methods as a discretized volume. Congruent elements are glued together to compile the domain over which the solution of a boundary value problem is sought. We associate a group and a graph to that volume. When the group is symmetry of the boundary value problem under investigation, one can specify the structure of the solution, and find out if there are equispectral volumes of a given type. The second technique uses a complex mapping to transplant the solution from volume to volume and a correction function. Equation for the correction function is given. A simple example demonstrates the feasibility of the suggested method.

  19. 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.

  20. Animation framework using volume visualization

    Science.gov (United States)

    Fang, Wenxuan; Wang, Hongli

    2004-03-01

    As the development of computer graphics, scientific visualization and advanced imaging scanner and sensor technology, high quality animation making of volume data set has been a challenging in industries. A simple animation framework by using current volume visualization techniques is proposed in this paper. The framework consists of two pipelines: one is surface based method by using marching cubes algorithm, the other is volume rendering method by using shear-warp method. The volume visualization results can not only be used as key frame sources in the animation making, but also can be directly used as animation when the volume visualization is in stereoscopic mode. The proposed framework can be applied into fields such as medical education, film-making and archaeology.

  1. Modeling of Craniofacial Anatomy, Variation, and Growth

    DEFF Research Database (Denmark)

    Thorup, Signe Strann

    The topic of this thesis is automatic analysis of craniofacial images with respect to changes due to growth and surgery, inter-subject variation and intracranial volume estimation. The methods proposed contribute to the knowledge about specific craniofacial anomalies, as well as provide a tool...... for detailed analyses for clinical and research purposes. Most of the applications in this thesis rely on non-rigid image registration by the means of warping one image into the coordinate system of another image. This warping results in a deformation field that describes the anatomical correspondence between...... the two images. To elaborate further: a computational atlas of the average anatomy was constructed. Using non-rigid registration, image data from a subject is automatically transformed into the coordinate space of the atlas. In this process, all knowledge built into the atlas is transferred to the subject...

  2. Sparse PDF Volumes for Consistent Multi-Resolution Volume Rendering

    KAUST Repository

    Sicat, Ronell Barrera

    2014-12-31

    This paper presents a new multi-resolution volume representation called sparse pdf volumes, which enables consistent multi-resolution volume rendering based on probability density functions (pdfs) of voxel neighborhoods. These pdfs are defined in the 4D domain jointly comprising the 3D volume and its 1D intensity range. Crucially, the computation of sparse pdf volumes exploits data coherence in 4D, resulting in a sparse representation with surprisingly low storage requirements. At run time, we dynamically apply transfer functions to the pdfs using simple and fast convolutions. Whereas standard low-pass filtering and down-sampling incur visible differences between resolution levels, the use of pdfs facilitates consistent results independent of the resolution level used. We describe the efficient out-of-core computation of large-scale sparse pdf volumes, using a novel iterative simplification procedure of a mixture of 4D Gaussians. Finally, our data structure is optimized to facilitate interactive multi-resolution volume rendering on GPUs.

  3. Sparse PDF Volumes for Consistent Multi-Resolution Volume Rendering.

    Science.gov (United States)

    Sicat, Ronell; Krüger, Jens; Möller, Torsten; Hadwiger, Markus

    2014-12-01

    This paper presents a new multi-resolution volume representation called sparse pdf volumes, which enables consistent multi-resolution volume rendering based on probability density functions (pdfs) of voxel neighborhoods. These pdfs are defined in the 4D domain jointly comprising the 3D volume and its 1D intensity range. Crucially, the computation of sparse pdf volumes exploits data coherence in 4D, resulting in a sparse representation with surprisingly low storage requirements. At run time, we dynamically apply transfer functions to the pdfs using simple and fast convolutions. Whereas standard low-pass filtering and down-sampling incur visible differences between resolution levels, the use of pdfs facilitates consistent results independent of the resolution level used. We describe the efficient out-of-core computation of large-scale sparse pdf volumes, using a novel iterative simplification procedure of a mixture of 4D Gaussians. Finally, our data structure is optimized to facilitate interactive multi-resolution volume rendering on GPUs.

  4. Geometric constrained variational calculus. II: The second variation (Part I)

    Science.gov (United States)

    Massa, Enrico; Bruno, Danilo; Luria, Gianvittorio; Pagani, Enrico

    2016-10-01

    Within the geometrical framework developed in [Geometric constrained variational calculus. I: Piecewise smooth extremals, Int. J. Geom. Methods Mod. Phys. 12 (2015) 1550061], the problem of minimality for constrained calculus of variations is analyzed among the class of differentiable curves. A fully covariant representation of the second variation of the action functional, based on a suitable gauge transformation of the Lagrangian, is explicitly worked out. Both necessary and sufficient conditions for minimality are proved, and reinterpreted in terms of Jacobi fields.

  5. FROG - Fingerprinting Genomic Variation Ontology.

    Directory of Open Access Journals (Sweden)

    E Abinaya

    Full Text Available Genetic variations play a crucial role in differential phenotypic outcomes. Given the complexity in establishing this correlation and the enormous data available today, it is imperative to design machine-readable, efficient methods to store, label, search and analyze this data. A semantic approach, FROG: "FingeRprinting Ontology of Genomic variations" is implemented to label variation data, based on its location, function and interactions. FROG has six levels to describe the variation annotation, namely, chromosome, DNA, RNA, protein, variations and interactions. Each level is a conceptual aggregation of logically connected attributes each of which comprises of various properties for the variant. For example, in chromosome level, one of the attributes is location of variation and which has two properties, allosomes or autosomes. Another attribute is variation kind which has four properties, namely, indel, deletion, insertion, substitution. Likewise, there are 48 attributes and 278 properties to capture the variation annotation across six levels. Each property is then assigned a bit score which in turn leads to generation of a binary fingerprint based on the combination of these properties (mostly taken from existing variation ontologies. FROG is a novel and unique method designed for the purpose of labeling the entire variation data generated till date for efficient storage, search and analysis. A web-based platform is designed as a test case for users to navigate sample datasets and generate fingerprints. The platform is available at http://ab-openlab.csir.res.in/frog.

  6. Measurement and determinants of infrarenal aortic thrombus volume

    Energy Technology Data Exchange (ETDEWEB)

    Golledge, Jonathan; Wolanski, Philippe [James Cook University, The Vascular Biology Unit, Townsville, Queensland (Australia); Townsville Hospital, Townsville, Queensland (Australia); Parr, Adam [James Cook University, The Vascular Biology Unit, Townsville, Queensland (Australia); Buttner, Petra [James Cook University, School of Public Health and Tropical Medicine, Townsville, Queensland (Australia)

    2008-09-15

    Intra-luminal thrombus has been suggested to play a role in the progression of abdominal aortic aneurysm (AAA). The aims of this study were twofold. Firstly, to assess the reproducibility of a computer tomography (CT)-based technique for measurement of aortic thrombus volume. Secondly, to examine the determinants of infrarenal aortic thrombus volume in a cohort of patients with aortic dilatation. A consecutive series of 75 patients assessed by CT angiography with maximum aortic diameter {>=}25 mm were recruited. Intra-luminal thrombus volume was measured by a semi-automated workstation protocol based on a previously defined technique to quantitate aortic calcification. Intra- and inter-observer reproducibility were assessed using correlation coefficients, coefficient of variation and Bland-Altman plots. Infrarenal aortic thrombus volume percentage was related to clinical, anatomical and blood characteristics of the patients using univariate and multivariate tests. Infrarenal aortic thrombus volume was related to the severity of aortic dilatation assessed by total aortic volume (r=0.87, P<0.0001) or maximum aortic diameter (r=0.74, P< 0.0001). We therefore examined the clinical determinates of aortic thrombus expressed as a percentage of total aortic volume. Aortic thrombus percentage was negatively correlated with serum high density lipoprotein (HDL, r=-0.31). By ordinal multiple logistic regression analysis serum HDL below median ({<=}1.2 mM) was associated with aortic thrombus percentage in the upper quartile adjusting for other risk factors (odds ratio 5.3, 95% CI 1.1-25.0). Infrarenal aortic thrombus volume can be measured reproducibly on CT. Serum HDL, which can be therapeutically raised, may play a role in discouraging aortic thrombus accumulation with implications in terms of delaying progression of AAA. (orig.)

  7. Hippocampal volume reduction in congenital central hypoventilation syndrome.

    Directory of Open Access Journals (Sweden)

    Paul M Macey

    Full Text Available Children with congenital central hypoventilation syndrome (CCHS, a genetic disorder characterized by diminished drive to breathe during sleep and impaired CO(2 sensitivity, show brain structural and functional changes on magnetic resonance imaging (MRI scans, with impaired responses in specific hippocampal regions, suggesting localized injury.We assessed total volume and regional variation in hippocampal surface morphology to identify areas affected in the syndrome. We studied 18 CCHS (mean age+/-std: 15.1+/-2.2 years; 8 female and 32 healthy control (age 15.2+/-2.4 years; 14 female children, and traced hippocampi on 1 mm(3 resolution T1-weighted scans, collected with a 3.0 Tesla MRI scanner. Regional hippocampal volume variations, adjusted for cranial volume, were compared between groups based on t-tests of surface distances to the structure midline, with correction for multiple comparisons. Significant tissue losses emerged in CCHS patients on the left side, with a trend for loss on the right; however, most areas affected on the left also showed equivalent right-sided volume reductions. Reduced regional volumes appeared in the left rostral hippocampus, bilateral areas in mid and mid-to-caudal regions, and a dorsal-caudal region, adjacent to the fimbria.The volume losses may result from hypoxic exposure following hypoventilation during sleep-disordered breathing, or from developmental or vascular consequences of genetic mutations in the syndrome. The sites of change overlap regions of abnormal functional responses to respiratory and autonomic challenges. Affected hippocampal areas have roles associated with memory, mood, and indirectly, autonomic regulation; impairments in these behavioral and physiological functions appear in CCHS.

  8. Incubator weaning in preterm infants and associated practice variation.

    Science.gov (United States)

    Schneiderman, R; Kirkby, S; Turenne, W; Greenspan, J

    2009-08-01

    To evaluate the relationship of weight of preterm infants when first placed into an open crib with days to full oral feedings, growth velocity and length of stay (LOS), and to identify unwarranted variation in incubator weaning after adjusting for severity indices. A retrospective study using the ParadigmHealth neonatal database from 2003 to 2006 reviewed incubator weaning to an open crib in appropriate-for-gestational-age (AGA) infants from 22 to weeks gestation. Primary outcome measurements included days to full oral (PO) feeding, weight gain from open crib to discharge and length of stay. Models were severity adjusted. To understand hospital practice variation, we also used a regression model to estimate the weight at open crib for the top 10 volume hospitals. In all 2908 infants met the inclusion criteria for the study. Their mean weight at open crib was 1850 g. On average every additional 100 g an infant weighed at the open crib was associated with increased time to full PO feeding by 0.8 days, decreased weight gained per day by 1 gram and increased LOS by 0.9 days. For the top 10 volume hospitals, severity variables alone accounted for 9% of the variation in weight at open crib, whereas the hospital in which the baby was treated accounted for an additional 19% of the variation. Even after controlling for severity, significant practice variation exists in weaning to an open crib, leading to potential delays in achieving full-volume oral feeds, decreased growth velocity and prolonged LOS.

  9. A new electric method for non-invasive continuous monitoring of stroke volume and ventricular volume-time curves

    Directory of Open Access Journals (Sweden)

    Konings Maurits K

    2012-08-01

    Full Text Available Abstract Background In this paper a new non-invasive, operator-free, continuous ventricular stroke volume monitoring device (Hemodynamic Cardiac Profiler, HCP is presented, that measures the average stroke volume (SV for each period of 20 seconds, as well as ventricular volume-time curves for each cardiac cycle, using a new electric method (Ventricular Field Recognition with six independent electrode pairs distributed over the frontal thoracic skin. In contrast to existing non-invasive electric methods, our method does not use the algorithms of impedance or bioreactance cardiography. Instead, our method is based on specific 2D spatial patterns on the thoracic skin, representing the distribution, over the thorax, of changes in the applied current field caused by cardiac volume changes during the cardiac cycle. Since total heart volume variation during the cardiac cycle is a poor indicator for ventricular stroke volume, our HCP separates atrial filling effects from ventricular filling effects, and retrieves the volume changes of only the ventricles. Methods ex-vivo experiments on a post-mortem human heart have been performed to measure the effects of increasing the blood volume inside the ventricles in isolation, leaving the atrial volume invariant (which can not be done in-vivo. These effects have been measured as a specific 2D pattern of voltage changes on the thoracic skin. Furthermore, a working prototype of the HCP has been developed that uses these ex-vivo results in an algorithm to decompose voltage changes, that were measured in-vivo by the HCP on the thoracic skin of a human volunteer, into an atrial component and a ventricular component, in almost real-time (with a delay of maximally 39 seconds. The HCP prototype has been tested in-vivo on 7 human volunteers, using G-suit inflation and deflation to provoke stroke volume changes, and LVot Doppler as a reference technique. Results The ex-vivo measurements showed that ventricular filling

  10. Effects of transplantation with bone marrow-derived mesenchymal stem cells modified by Survivin on experimental stroke in rats

    Directory of Open Access Journals (Sweden)

    Cheng Ronghua

    2011-07-01

    Full Text Available Abstract Background This study was performed to determine whether injury induced by cerebral ischemia could be further improved by transplantation with bone marrow-derived mesenchymal stem cells (MSCs modified by Survivin (SVV. Methods MSCs derived from bone marrow of male Sprague-Dawley rats were infected by the self-inactive lentiviral vector GCFU carrying green fluorescent protein (GFP gene and SVV recombinant vector (GCFU-SVV. In vitro, vascular endothelial growth factor (VEGF and basic fibroblast growth factor (bFGF were detected in infected MSCs supernatants under hypoxic conditions by ELSIA. In vivo, experiments consisted of three groups, one receiving intravenous injection of 500 μl of phosphate-buffered saline (PBS without cells (control group and two groups administered the same volume solution with either three million GFP-MSCs (group GFP or SVV/GFP-MSCs (group SVV. All animals were submitted to 2-hour middle cerebral artery occlusion (MCAO and then reperfusion. Differentiation and survival of the transplanted MSCs were determined by confocal microscope. Western blot was used to detect the expression of VEGF and bFGF in ischemic tissue. A 2,3,5-triphenyltetrazolium chloride (TTC staining was used to assess the infarct volume. Evaluation of neurological function was performed using a modified Neurological Severity Score (mNSS. Results In vitro, modification with SVV further increased secretion of VEGF and bFGF under hypoxic condition. In vivo, only very few transplantated cells co-expressed GFP and NeuN. The survival transplanted cells in the group SVV was 1.3-fold at 4 days after transplantation and 3.4-fold higher at 14 days after transplantation, respectively, when compared with group GFP. Expression of VEGF and bFGF in the ischemic tissue were further up-regulated by modification with SVV. Moreover, modification with SVV further reduced the cerebral infarct volume by 5.2% at 4 days after stroke and improved post

  11. Spectral-collocation variational integrators

    Science.gov (United States)

    Li, Yiqun; Wu, Boying; Leok, Melvin

    2017-03-01

    Spectral methods are a popular choice for constructing numerical approximations for smooth problems, as they can achieve geometric rates of convergence and have a relatively small memory footprint. In this paper, we introduce a general framework to convert a spectral-collocation method into a shooting-based variational integrator for Hamiltonian systems. We also compare the proposed spectral-collocation variational integrators to spectral-collocation methods and Galerkin spectral variational integrators in terms of their ability to reproduce accurate trajectories in configuration and phase space, their ability to conserve momentum and energy, as well as the relative computational efficiency of these methods when applied to some classical Hamiltonian systems. In particular, we note that spectrally-accurate variational integrators, such as the Galerkin spectral variational integrators and the spectral-collocation variational integrators, combine the computational efficiency of spectral methods together with the geometric structure-preserving and long-time structural stability properties of symplectic integrators.

  12. Minivoids in the Local Volume

    CERN Document Server

    Tikhonov, A V

    2006-01-01

    We consider a sphere of 7.5 Mpc radius, which contains 355 galaxies with accurately measured distances, to detect the nearest empty volumes. Using a simple void detection algorithm, we found six large (mini)voids in Aquila, Eridanus, Leo, Vela, Cepheus and Octans, each of more than 30 Mpc^3. Besides them, 24 middle-size "bubbles" of more than 5 Mpc^3 volume are detected, as well as 52 small "pores". The six largest minivoids occupy 58% of the considered volume. Addition of the bubbles and pores to them increases the total empty volume up to 75% and 81%, respectively. The detected local voids look like oblong potatoes with typical axial ratios b/a = 0.75 and c/a = 0.62 (in the triaxial ellipsoide approximation). Being arranged by the size of their volume, local voids follow power law of volumes-rankes dependence. A correlation Gamma-function of the Local Volume galaxies follows a power low with a formally calculated fractal dimension D = 1.5. We found that galaxies surrounding the local minivoids do not differ...

  13. A Simple Mercury-Free Laboratory Apparatus to Study the Relationship between Pressure, Volume, and Temperature in a Gas

    Science.gov (United States)

    McGregor, Donna; Sweeney, William V.; Mills, Pamela

    2012-01-01

    A simple and inexpensive mercury-free apparatus to measure the change in volume of a gas as a function of pressure at different temperatures is described. The apparatus is simpler than many found in the literature and can be used to study variations in pressure, volume, and temperature. (Contains 1 table and 7 figures.)

  14. A Simple Mercury-Free Laboratory Apparatus to Study the Relationship between Pressure, Volume, and Temperature in a Gas

    Science.gov (United States)

    McGregor, Donna; Sweeney, William V.; Mills, Pamela

    2012-01-01

    A simple and inexpensive mercury-free apparatus to measure the change in volume of a gas as a function of pressure at different temperatures is described. The apparatus is simpler than many found in the literature and can be used to study variations in pressure, volume, and temperature. (Contains 1 table and 7 figures.)

  15. The Split Variational Inequality Problem

    CERN Document Server

    Censor, Yair; Reich, Simeon

    2010-01-01

    We propose a new variational problem which we call the Split Variational Inequality Problem (SVIP). It entails finding a solution of one Variational Inequality Problem (VIP), the image of which under a given bounded linear transformation is a solution of another VIP. We construct iterative algorithms that solve such problems, under reasonable conditions, in Hilbert space and then discuss special cases, some of which are new even in Euclidean space.

  16. Diurnal variation of mountain waves

    Directory of Open Access Journals (Sweden)

    R. M. Worthington

    2006-11-01

    Full Text Available Mountain waves could be modified as the boundary layer varies between stable and convective. However case studies show mountain waves day and night, and above e.g. convective rolls with precipitation lines over mountains. VHF radar measurements of vertical wind (1990–2006 confirm a seasonal variation of mountain-wave amplitude, yet there is little diurnal variation of amplitude. Mountain-wave azimuth shows possible diurnal variation compared to wind rotation across the boundary layer.

  17. Periodic insolation variations on Mars.

    Science.gov (United States)

    Murray, B C; Ward, W R; Yeung, S C

    1973-05-11

    Previously unrecognized insolation variations on Mars are a consequence of periodic variations in eccentricity, first established by the theory of Brouwer and Van Woerkom (1950). Such annual insolation variations, characterized by both 95,000-year and 2,000,000-year periodicities, may actually be recorded in newly discovered layered deposits in the polar regions of Mars. An additional north-south variation in seasonal insolation, but not average annual insolation, exists with 51,000-year and 2,000,000-year periodicities.

  18. 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....

  19. 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...

  20. Explorations in Regional Variation: A Variational Pragmatic Perspective

    Science.gov (United States)

    Barron, Anne

    2015-01-01

    The present article introduces the Special Issue entitled "A Variational Pragmatic Approach to Regional Variation in Language," a collection of papers which celebrates the work of Klaus P. Schneider (Rheinische Friedrich-Wilhelms-Universität Bonn, Germany) on the occasion of his 60th birthday.

  1. 10 CFR 63.332 - Representative volume.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Representative volume. 63.332 Section 63.332 Energy... Protection Standards § 63.332 Representative volume. (a) The representative volume is the volume of ground... radionuclides released from the Yucca Mountain disposal system that will be in the representative volume....

  2. Bare-Hand Volume Cracker for Raw Volume Data Analysis

    Directory of Open Access Journals (Sweden)

    Bireswar Laha

    2016-09-01

    Full Text Available Analysis of raw volume data generated from different scanning technologies faces a variety of challenges, related to search, pattern recognition, spatial understanding, quantitative estimation, and shape description. In a previous study, we found that the Volume Cracker (VC 3D interaction (3DI technique mitigated some of these problems, but this result was from a tethered glove-based system with users analyzing simulated data. Here, we redesigned the VC by using untethered bare-hand interaction with real volume datasets, with a broader aim of adoption of this technique in research labs. We developed symmetric and asymmetric interfaces for the Bare-Hand Volume Cracker (BHVC through design iterations with a biomechanics scientist. We evaluated our asymmetric BHVC technique against standard 2D and widely used 3D interaction techniques with experts analyzing scanned beetle datasets. We found that our BHVC design significantly outperformed the other two techniques. This study contributes a practical 3DI design for scientists, documents lessons learned while redesigning for bare-hand trackers, and provides evidence suggesting that 3D interaction could improve volume data analysis for a variety of visual analysis tasks. Our contribution is in the realm of 3D user interfaces tightly integrated with visualization, for improving the effectiveness of visual analysis of volume datasets. Based on our experience, we also provide some insights into hardware-agnostic principles for design of effective interaction techniques.

  3. TOTAL WOOD VOLUME ESTIMATION OF EUCALYPTUS SPECIES BY IMAGES OF LANDSAT SATELLITE

    Directory of Open Access Journals (Sweden)

    Elias Fernando Berra

    2012-12-01

    Full Text Available http://dx.doi.org/10.5902/198050987566Models relating spectral answers with biophysical parameters aim estimate variables, like wood volume, without the necessity of frequent field measurements. The objective was to develop models to estimate wood volume by Landsat 5 TM images, supported by regional forest inventory data. The image was geo-referenced and converted to spectral reflectance. After, the images-index NDVI (Normalized Difference Vegetation Index and SR (Simple Ratio was generated. The reflectance values of the bands (TM1, TM2, TM3 e TM4 and of the indices (NDVI and SR was related with the wood volume. The biggest correlation with volume was with the NDVI and SR indices. The variables selection was made by Stepwise method, which returned three regression models as significant to explain the variation in volume. Finally, the best fitted model was selected (volume = -830,95 + 46,05 (SR + 107,47 (TM2, which was applied on the Landsat image where the pixels had started to represent the estimated volume in m³/ha on the Eucalyptus sp. production units. This model, significant at 95% confidence level, explains 68% of the wood volume variation.

  4. Semiautomatic regional segmentation to measure orbital fat volumes in thyroid-associated ophthalmopathy. A validation study.

    Science.gov (United States)

    Comerci, M; Elefante, A; Strianese, D; Senese, R; Bonavolontà, P; Alfano, B; Bonavolontà, B; Brunetti, A

    2013-08-01

    This study was designed to validate a novel semi-automated segmentation method to measure regional intra-orbital fat tissue volume in Graves' ophthalmopathy. Twenty-four orbits from 12 patients with Graves' ophthalmopathy, 24 orbits from 12 controls, ten orbits from five MRI study simulations and two orbits from a digital model were used. Following manual region of interest definition of the orbital volumes performed by two operators with different levels of expertise, an automated procedure calculated intra-orbital fat tissue volumes (global and regional, with automated definition of four quadrants). In patients with Graves' disease, clinical activity score and degree of exophthalmos were measured and correlated with intra-orbital fat volumes. Operator performance was evaluated and statistical analysis of the measurements was performed. Accurate intra-orbital fat volume measurements were obtained with coefficients of variation below 5%. The mean operator difference in total fat volume measurements was 0.56%. Patients had significantly higher intra-orbital fat volumes than controls (p<0.001 using Student's t test). Fat volumes and clinical score were significantly correlated (p<0.001). The semi-automated method described here can provide accurate, reproducible intra-orbital fat measurements with low inter-operator variation and good correlation with clinical data.

  5. Seasonal variations in urinary risk factors among patients with nephrolithiasis

    Science.gov (United States)

    Hill, K.; Poindexter, J.; Pak, C. Y.

    1991-01-01

    Twenty-four hour urine specimens from 5,677 stone-forming patients throughout the United States were analyzed for seasonal variations in urinary risk factors for nephrolithiasis. Determinations were performed for urine volume, pH, calcium, oxalate, phosphorus, sodium, magnesium, citrate, sulfate, uric acid, and the relative supersaturation (RS) of calcium oxalate, brushite, monosodium urate, and uric acid. Criteria for significant seasonal variation included a significant difference in monthly means of risk factors, seasonal grouping of the data by the Student-Newman-Keuls multiple range test, consistent year-to-year trends and a physiologically significant range. Minimum urine volume of 1.54 +/- 0.70 SD L/day occurred in October while a maximum urine volume of 1.76 +/- 0.78 SD L/day was observed during February. Minimum urine pH of 5.94 +/- 0.64 SD was observed during July and August while a maximum pH of 6.18 +/- 0.61 SD was observed during February. Daily urinary excretion of sodium was lowest during August, 158 +/- 74 SD mEq/day and highest during February 177 +/- 70 SD mEq/day. The RS of brushite and uric acid were found to display significant pH-dependent seasonal variation with a maximum RS of uric acid 2.26 +/- 1.98 SD in June and a low of 1.48 +/- 1.30 SD in February. Maximum RS of brushite 2.75 +/- 2.58 was observed during February. Minimum RS of brushite 1.93 +/- 1.70 SD was observed in June. Phosphorus excretion displayed seasonal variation about a spring-fall axis with a maximum value 1042 +/- 373 SD mg/day in April and a minimum value of 895 +/- 289 SD mg/day. Urine volume, sodium, and pH were significantly lower during the summer (June, July, August) than in the winter (December, January, February). The RS of uric acid was higher, but that of brushite and monosodium urate was lower in the summer than in the winter. The seasonal changes observed in urine volume, pH, sodium, and the RS of brushite and uric acid are consistent with summertime sweating

  6. Big Data Analysis of Human Genome Variations

    KAUST Repository

    Gojobori, Takashi

    2016-01-25

    Since the human genome draft sequence was in public for the first time in 2000, genomic analyses have been intensively extended to the population level. The following three international projects are good examples for large-scale studies of human genome variations: 1) HapMap Data (1,417 individuals) (http://hapmap.ncbi.nlm.nih.gov/downloads/genotypes/2010-08_phaseII+III/forward/), 2) HGDP (Human Genome Diversity Project) Data (940 individuals) (http://www.hagsc.org/hgdp/files.html), 3) 1000 genomes Data (2,504 individuals) http://ftp.1000genomes.ebi.ac.uk/vol1/ftp/release/20130502/ If we can integrate all three data into a single volume of data, we should be able to conduct a more detailed analysis of human genome variations for a total number of 4,861 individuals (= 1,417+940+2,504 individuals). In fact, we successfully integrated these three data sets by use of information on the reference human genome sequence, and we conducted the big data analysis. In particular, we constructed a phylogenetic tree of about 5,000 human individuals at the genome level. As a result, we were able to identify clusters of ethnic groups, with detectable admixture, that were not possible by an analysis of each of the three data sets. Here, we report the outcome of this kind of big data analyses and discuss evolutionary significance of human genomic variations. Note that the present study was conducted in collaboration with Katsuhiko Mineta and Kosuke Goto at KAUST.

  7. Moral values are associated with individual differences in regional brain volume.

    Science.gov (United States)

    Lewis, Gary J; Kanai, Ryota; Bates, Timothy C; Rees, Geraint

    2012-08-01

    Moral sentiment has been hypothesized to reflect evolved adaptations to social living. If so, individual differences in moral values may relate to regional variation in brain structure. We tested this hypothesis in a sample of 70 young, healthy adults examining whether differences on two major dimensions of moral values were significantly associated with regional gray matter volume. The two clusters of moral values assessed were "individualizing" (values of harm/care and fairness) and "binding" (deference to authority, in-group loyalty, and purity/sanctity). Individualizing was positively associated with left dorsomedial pFC volume and negatively associated with bilateral precuneus volume. For binding, a significant positive association was found for bilateral subcallosal gyrus and a trend to significance for the left anterior insula volume. These findings demonstrate that variation in moral sentiment reflects individual differences in brain structure and suggest a biological basis for moral sentiment, distributed across multiple brain regions.

  8. Pulse pressure variation to predict fluid responsiveness in spontaneously breathing patients: tidal vs. forced inspiratory breathing.

    Science.gov (United States)

    Hong, D M; Lee, J M; Seo, J H; Min, J J; Jeon, Y; Bahk, J H

    2014-07-01

    We evaluated whether pulse pressure variation can predict fluid responsiveness in spontaneously breathing patients. Fifty-nine elective thoracic surgical patients were studied before induction of general anaesthesia. After volume expansion with hydroxyethyl starch 6 ml.kg(-1) , patients were defined as responders by a ≥ 15% increase in the cardiac index. Haemodynamic variables were measured before and after volume expansion and pulse pressure variations were calculated during tidal breathing and during forced inspiratory breathing. Median (IQR [range]) pulse pressure variation during forced inspiratory breathing was significantly higher in responders (n = 29) than in non-responders (n = 30) before volume expansion (18.2 (IQR 14.7-18.2 [9.3-31.3])% vs. 10.1 (IQR 8.3-12.6 [4.8-21.1])%, respectively, p breathing could predict fluid responsiveness (area under the curve 0.910, p breathing can be used to guide fluid management in spontaneously breathing patients.

  9. VOLUMNECT: measuring volumes with Kinect

    Science.gov (United States)

    Quintino Ferreira, Beatriz; Griné, Miguel; Gameiro, Duarte; Costeira, João. Paulo; Sousa Santos, Beatriz

    2014-03-01

    This article presents a solution to volume measurement object packing using 3D cameras (such as the Microsoft KinectTM). We target application scenarios, such as warehouses or distribution and logistics companies, where it is important to promptly compute package volumes, yet high accuracy is not pivotal. Our application auto- matically detects cuboid objects using the depth camera data and computes their volume and sorting it allowing space optimization. The proposed methodology applies to a point cloud simple computer vision and image processing methods, as connected components, morphological operations and Harris corner detector, producing encouraging results, namely an accuracy in volume measurement of 8mm. Aspects that can be further improved are identified; nevertheless, the current solution is already promising turning out to be cost effective for the envisaged scenarios.

  10. Anadromous fish inventory: Summary volume

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Summary volume, with discussion, on anadromous fish inventories, species lists, histories of fisheries, habitat, key spawning and rearing areas, runs/escapements,...

  11. Organ volume estimation using SPECT

    CERN Document Server

    Zaidi, H

    1996-01-01

    Knowledge of in vivo thyroid volume has both diagnostic and therapeutic importance and could lead to a more precise quantification of absolute activity contained in the thyroid gland. In order to improve single-photon emission computed tomography (SPECT) quantitation, attenuation correction was performed according to Chang's algorithm. The dual-window method was used for scatter subtraction. We used a Monte Carlo simulation of the SPECT system to accurately determine the scatter multiplier factor k. Volume estimation using SPECT was performed by summing up the volume elements (voxels) lying within the contour of the object, determined by a fixed threshold and the gray level histogram (GLH) method. Thyroid phantom and patient studies were performed and the influence of 1) fixed thresholding, 2) automatic thresholding, 3) attenuation, 4) scatter, and 5) reconstruction filter were investigated. This study shows that accurate volume estimation of the thyroid gland is feasible when accurate corrections are perform...

  12. Volume inside old black holes

    Science.gov (United States)

    Christodoulou, Marios; De Lorenzo, Tommaso

    2016-11-01

    Black holes that have nearly evaporated are often thought of as small objects, due to their tiny exterior area. However, the horizon bounds large spacelike hypersurfaces. A compelling geometric perspective on the evolution of the interior geometry was recently shown to be provided by a generally covariant definition of the volume inside a black hole using maximal surfaces. In this article, we expand on previous results and show that finding the maximal surfaces in an arbitrary spherically symmetric spacetime is equivalent to a 1 +1 geodesic problem. We then study the effect of Hawking radiation on the volume by computing the volume of maximal surfaces inside the apparent horizon of an evaporating black hole as a function of time at infinity: while the area is shrinking, the volume of these surfaces grows monotonically with advanced time, up to when the horizon has reached Planckian dimensions. The physical relevance of these results for the information paradox and the remnant scenarios are discussed.

  13. Volumetric measurement of tank volume

    Science.gov (United States)

    Walter, Richard T. (Inventor); Vanbuskirk, Paul D. (Inventor); Weber, William F. (Inventor); Froebel, Richard C. (Inventor)

    1991-01-01

    A method is disclosed for determining the volume of compressible gas in a system including incompressible substances in a zero-gravity environment consisting of measuring the change in pressure (delta P) for a known volume change rate (delta V/delta t) in the polytrophic region between isothermal and adiabatic conditions. The measurements are utilized in an idealized formula for determining the change in isothermal pressure (delta P sub iso) for the gas. From the isothermal pressure change (delta iso) the gas volume is obtained. The method is also applicable to determination of gas volume by utilizing work (W) in the compression process. In a passive system, the relationship of specific densities can be obtained.

  14. Gravitational tension, spacetime pressure and black hole volume

    Science.gov (United States)

    Armas, Jay; Obers, Niels A.; Sanchioni, Marco

    2016-09-01

    We study the first law of black hole thermodynamics in the presence of surrounding gravitational fields and argue that variations of these fields are naturally incorporated in the first law by defining gravitational tension or gravitational binding energy. We demonstrate that this notion can also be applied in Anti-de Sitter spacetime, in which the surrounding gravitational field is sourced by a cosmological fluid, therefore showing that spacetime volume and gravitational tension encode the same physics as spacetime pressure and black hole volume. We furthermore show that it is possible to introduce a definition of spacetime pressure and black hole volume for any spacetime with characteristic length scales which does not necessarily require a cosmological constant sourcing Einstein equations. However, we show that black hole volume is non-universal in the flat spacetime limit, questioning its significance. We illustrate these ideas by studying the resulting black hole volume of Kaluza-Klein black holes and of a toy model for a black hole binary system in five spacetime dimensions (the black saturn solution) as well as of several novel perturbative black hole solutions. These include the higher-dimensional Kerr-Newman solution in Anti-de Sitter spacetime as well as other black holes in plane wave and Lifshitz spacetimes.

  15. Ultrasonographic Measures of Volume Responsiveness

    Science.gov (United States)

    2017-02-01

    AFRL-SA-WP-SR-2017-0005 Ultrasonographic Measures of Volume Responsiveness Sarah B. Murthi, MD February 2017...use, or sell any patented invention that may relate to them. Qualified requestors may obtain copies of this report from the Defense Technical...TITLE AND SUBTITLE Ultrasonographic Measures of Volume Responsiveness 5a. CONTRACT NUMBER FA8650-13-2-6D10 5b. GRANT NUMBER 5c. PROGRAM

  16. Volumes of Polytopes Without Triangulations

    CERN Document Server

    Enciso, Michael

    2014-01-01

    We introduce a new formalism for defining and computing the volumes of completely general polytopes in any dimension. The expressions that we obtain for these volumes are independent of any triangulation, and manifestly depend only on the vertices of the underlying polytope. As one application of this formalism, we obtain new expressions for tree-level, n-point NMHV amplitudes in N=4 Super Yang-Mills (SYM) theory.

  17. Disorders of Erythrocyte Volume Homeostasis

    OpenAIRE

    Glogowska, Edyta; Gallagher, Patrick G.

    2015-01-01

    Inherited disorders of erythrocyte volume homeostasis are a heterogeneous group of rare disorders with phenotypes ranging from dehydrated to overhydrated erythrocytes. Clinical, laboratory, physiologic, and genetic heterogeneity characterize this group of disorders. A series of recent reports have provided novel insights into our understanding of the genetic bases underlying some of these disorders of red cell volume regulation. This report reviews this progress in understanding determinants ...

  18. Variational Bounds for Creeping Composites

    Science.gov (United States)

    Procházka, Petr

    2010-05-01

    In the paper time dependent variational bounds are derived based on Extended Hashin-Shtrikman variational principles. Direct calculation leads to explicit formulas to be presented in the text. For various mechanical properties easy coding in Excel, say, can be used and verification of accuracy for numerical procedures is available using the derived formulas.

  19. Robust Understanding of Statistical Variation

    Science.gov (United States)

    Peters, Susan A.

    2011-01-01

    This paper presents a framework that captures the complexity of reasoning about variation in ways that are indicative of robust understanding and describes reasoning as a blend of design, data-centric, and modeling perspectives. Robust understanding is indicated by integrated reasoning about variation within each perspective and across…

  20. Exploiting Natural Variation in Arabidopsis

    NARCIS (Netherlands)

    Molenaar, J.A.; Keurentjes, J.J.B.

    2014-01-01

    Natural variation for many traits is present within the species Arabidopsis thaliana . This chapter describes the use of natural variation to elucidate genes underlying the regulation of quantitative traits. It deals with the development and use of mapping populations, the detection and handling of

  1. Exploiting natural variation in Arabidopsis

    NARCIS (Netherlands)

    J.A. Molenaar; J.J.B. Keurentjes

    2014-01-01

    Natural variation for many traits is present within the species Arabidopsis thaliana. This chapter describes the use of natural variation to elucidate genes underlying the regulation of quantitative traits. It deals with the development and use of mapping populations, the detection and handling of g

  2. COORDINATION BETWEEN RIBS MOTION AND THORACOABDOMINAL VOLUMES IN SWIMMERS DURING RESPIRATORY MANEUVERS

    OpenAIRE

    Karine J. Sarro; Barros, Ricardo M.L.; Silvatti, Amanda P.

    2008-01-01

    This work aimed to verify if swimmers present better chest wall coordination during breathing than healthy non-athletes analyzing the correlation between ribs motion and the variation of thoracoabdominal volumes. The results of two up-to-date methods based on videogrammetry were correlated in this study. The first one measured the volumes of 4 separate compartments of the chest wall (superior thorax, inferior thorax, superior abdomen and inferior abdomen) as a function of time. The second cal...

  3. Exploring language variation across Europe

    DEFF Research Database (Denmark)

    Hovy, Dirk; Johannsen, Anders Trærup

    2016-01-01

    Language varies not only between countries, but also along regional and sociodemographic lines. This variation is one of the driving factors behind language change. However, investigating language variation is a complex undertaking: the more factors we want to consider, the more data we need...... training in both variational linguistics and computational methods, a combination that is still not common. We take a first step here to alleviate the problem by providing an interface to explore large-scale language variation along several socio-demographic factors without programming knowledge. It makes...... use of large amounts of data and provides statistical analyses, maps, and interactive features that enable scholars to explore language variation in a data-driven way....

  4. Comparing variation across European countries

    DEFF Research Database (Denmark)

    Thygesen, Lau C; Baixauli-Pérez, Cristobal; Librero-López, Julián

    2015-01-01

    BACKGROUND: In geographical studies, population distribution is a key issue. An unequal distribution across units of analysis might entail extra-variation and produce misleading conclusions on healthcare performance variations. This article aims at assessing the impact of building more homogeneous...... units of analysis in the estimation of systematic variation in three countries. METHODS: Hospital discharges for six conditions (congestive heart failure, short-term complications of diabetes, hip fracture, knee replacement, prostatectomy in prostate cancer and percutaneous coronary intervention...... of variation such as Extremal Quotient, Interquartile Interval ratio, Systematic Component of Variation and Empirical Bayes statistic. RESULTS: Ward's method reduced the number of areas, allowing a more homogeneous population distribution, yet 20% of the areas in Portugal exhibited less than 100 000...

  5. Fonetisk variation som social praksis

    DEFF Research Database (Denmark)

    Maegaard, Marie

    2010-01-01

    VARIATION I KØBENHAVNSK Sproglig variation kan betragtes på mange måder og ud fra mange forskellige perspektiver alt afhængig af erkendelsesinteresse og fagligt ståsted. I denne artikel vil jeg redegøre for et praksisperspektiv på sproglig variation, og jeg vil give eksempler på analyser af...... fonetisk variation blandt københavnske unge set som social praksis. Fonetisk variation i københavnsk er i de fleste kvantitative sociolingvistiske undersøgelser studeret med udgangspunkt i makrosociale kategorier baseret på alder, køn eller socialklasse (eks. Brink & Lund 1975, Jørgensen 1980, Gregersen...

  6. Variations in pore characteristics in high volatile bituminous coals: Implications for coal bed gas content

    Science.gov (United States)

    Mastalerz, Maria; Drobniak, A.; Strapoc, D.; Solano-Acosta, W.; Rupp, J.

    2008-01-01

    The Seelyville Coal Member of the Linton Formation (Pennsylvanian) in Indiana was studied to: 1) understand variations in pore characteristics within a coal seam at a single location and compare these variations with changes occurring between the same coal at different locations, 2) elaborate on the influence of mineral-matter and maceral composition on mesopore and micropore characteristics, and 3) discuss implications of these variations for coal bed gas content. The coal is high volatile bituminous rank with R0 ranging from 0.57% to 0.60%. BET specific surface areas (determined by nitrogen adsorption) of the coals samples studied range from 1.8 to 22.9??m2/g, BJH adsorption mesopore volumes from 0.0041 to 0.0339??cm3/g, and micropore volumes (determined by carbon dioxide adsorption) from 0.0315 to 0.0540??cm3/g. The coals that had the largest specific surface areas and largest mesopore volumes occur at the shallowest depths, whereas the smallest values for these two parameters occur in the deepest coals. Micropore volumes, in contrast, are not depth-dependent. In the coal samples examined for this study, mineral-matter content influenced both specific surface area as well as mesopore and micropore volumes. It is especially clear in the case of micropores, where an increase in mineral-matter content parallels the decrease of micropore volume of the coal. No obvious relationships were observed between the total vitrinite content and pore characteristics but, after splitting vitrinite into individual macerals, we see that collotelinite influences both meso- and micropore volume positively, whereas collodetrinite contributes to the reduction of mesopore and micropore volumes. There are large variations in gas content within a single coal at a single location. Because of this variability, the entire thickness of the coal must be desorbed in order to determine gas content reliably and to accurately calculate the level of gas saturation. ?? 2008 Elsevier B.V. All

  7. Managing Variation and Resolving the Trade-off Implications of Global Supply

    Institute of Scientific and Technical Information of China (English)

    R; Stratton

    2002-01-01

    The reduction of wasteful variation within the supp ly chain is naturally suited to high and stable volumes, as epitomised in the lean practices of the automotive industry. However, with the growth of innovative pr oducts, typically characterised by lower volumes and uncertain demand, it is als o important to develop strategies to effectively manage the externally imposed v ariation resulting from volatile market demand. Such strategies often come under the banner of quick response or agile supply. Syst...

  8. Some Variations on Total Variation-Based Image Smoothing

    Science.gov (United States)

    2009-03-01

    influential paper, Rudin, Osher, and Fatemi [23] suggested using the bounded variation seminorm to smooth images. The functional proposed in their work has...unit square I = [0, 1]2, where the bounded variation seminorm is defined as |f |BV(I) := ∫ I |Df(x)| dx := sup {∫ I f ∇ · p ∣∣∣ p : I → R2,(1) p ∈ C1(I...approximation to the ROF functional. In Section 3, we propose a new formulation of an upwind finite-difference approximation to the bounded variation seminorm

  9. Effect of hospital volume on processes of breast cancer care: A National Cancer Data Base study.

    Science.gov (United States)

    Yen, Tina W F; Pezzin, Liliana E; Li, Jianing; Sparapani, Rodney; Laud, Purushuttom W; Nattinger, Ann B

    2017-05-15

    The purpose of this study was to examine variations in delivery of several breast cancer processes of care that are correlated with lower mortality and disease recurrence, and to determine the extent to which hospital volume explains this variation. Women who were diagnosed with stage I-III unilateral breast cancer between 2007 and 2011 were identified within the National Cancer Data Base. Multiple logistic regression models were developed to determine whether hospital volume was independently associated with each of 10 individual process of care measures addressing diagnosis and treatment, and 2 composite measures assessing appropriateness of systemic treatment (chemotherapy and hormonal therapy) and locoregional treatment (margin status and radiation therapy). Among 573,571 women treated at 1755 different hospitals, 38%, 51%, and 10% were treated at high-, medium-, and low-volume hospitals, respectively. On multivariate analysis controlling for patient sociodemographic characteristics, treatment year and geographic location, hospital volume was a significant predictor for cancer diagnosis by initial biopsy (medium volume: odds ratio [OR] = 1.15, 95% confidence interval [CI] = 1.05-1.25; high volume: OR = 1.30, 95% CI = 1.14-1.49), negative surgical margins (medium volume: OR = 1.15, 95% CI = 1.06-1.24; high volume: OR = 1.28, 95% CI = 1.13-1.44), and appropriate locoregional treatment (medium volume: OR = 1.12, 95% CI = 1.07-1.17; high volume: OR = 1.16, 95% CI = 1.09-1.24). Diagnosis of breast cancer before initial surgery, negative surgical margins and appropriate use of radiation therapy may partially explain the volume-survival relationship. Dissemination of these processes of care to a broader group of hospitals could potentially improve the overall quality of care and outcomes of breast cancer survivors. Cancer 2017;123:957-66. © 2016 American Cancer Society. © 2016 American Cancer Society.

  10. Variational analysis and aerospace engineering mathematical challenges for the aerospace of the future

    CERN Document Server

    Mohammadi, Bijan; Pironneau, Olivier; Cipolla, Vittorio

    2016-01-01

    This book presents papers surrounding the extensive discussions that took place from the ‘Variational Analysis and Aerospace Engineering’ workshop held at the Ettore Majorana Foundation and Centre for Scientific Culture in 2015. Contributions to this volume focus on advanced mathematical methods in aerospace engineering and industrial engineering such as computational fluid dynamics methods, optimization methods in aerodynamics, optimum controls, dynamic systems, the theory of structures, space missions, flight mechanics, control theory, algebraic geometry for CAD applications, and variational methods and applications. Advanced graduate students, researchers, and professionals in mathematics and engineering will find this volume useful as it illustrates current collaborative research projects in applied mathematics and aerospace engineering.

  11. [La Medicina del Lavoro: 100 volumes].

    Science.gov (United States)

    Zocchetti, C

    2009-01-01

    With these pages La Medicina del Lavoro starts its 100th volume, so we have yet another historical occasion to celebrate the oldest occupational health journal in the world that is still publishing. Over the last few years we have had many occasions to celebrate, for example several anniversaries of the Journal (the 80th volume in 1989, 90 years in 1992, 100 years in 2001); the centenary of the foundation of the Clinica del Lavoro "Luigi Devoto" of Milan in 2001; the celebration of the 300 years' anniversary of the publication of De Morbis Artificum Diatriba by Bernardino Ramazzini, and we obviously hope to continue for many years to come in this positive outlook. One hundred volumes makes for a very large collection, with the highs and lows ofthe Journal's history (here we mean the variations in number of pages and physical size of the Journal). It is thanks to the Editors-in-chief(there have been very few so we can cite them all: Luigi Devoto, 1901-1936; Luigi Preti, 1936-1941; Enrico Vigliani, 1943-1992; e Vito Foà, 1992 to the present); the contributors who in various ways and with varying degrees of commitment but always with an exceptional personal participation, that it has been possible to reach 100 volumes, starting with C. Moreschi who, along with Luigi Devoto, was the first and sole editor at the Journal's foundation; up to the present extended and impressive editorial board; the printers (from the first. Tipografia Cooperativa, Via dei Molini in Pavia, to the latest: Casa Editrice Mattioli in Fidenza); the sponsors, including the most evident who, via advertising (rather limited as a matter offact), directly gave information about themselves, but also those who have often been or are behind the scenes, ensuring fundamental support which is not visible; content. articles, news, events, reports, ideas, opinions, photographs, tables, numbers... etc, which are really impossible to sum up. But the true collection which, for obvious reasons, cannot be

  12. Insular volume reduction in schizophrenia.

    Science.gov (United States)

    Saze, Teruyasu; Hirao, Kazuyuki; Namiki, Chihiro; Fukuyama, Hidenao; Hayashi, Takuji; Murai, Toshiya

    2007-12-01

    Structural and functional abnormalities of the insular cortex have been reported in patients with schizophrenia. Most studies have shown that the insular volumes in schizophrenia patients are smaller than those of healthy people. As the insular cortex is functio-anatomically divided into anterior and posterior subdivisons, recent research is focused on uncovering a specific subdivisional abnormality of the insula in patients with schizophrenia. A recent ROI-based volumetric MRI study demonstrated specific left anterior insular volume reduction in chronic schizophrenia patients (Makris N, Goldstein J, Kennedy D, Hodge S, Caviness V, Faraone S, Tsuang M, Seidman L (2006) Decreased volume of left and total anterior insular lobule in schizophrenia. Schizophr Res 83:155-171). On the other hand, our VBM-based volumetric study revealed a reduction in right posterior insular volume (Yamada M, Hirao K, Namiki C, Hanakawa T, Fukuyama H, Hayashi T, Murai T (2007) Social cognition and frontal lobe pathology in schizophrenia: a voxel-based morphometric study. NeuroImage 35:292-298). In order to address these controversial results, ROI-based subdivisional volumetry was performed using the MRI images from the same population we analyzed in our previous VBM-study. The sample group comprised 20 schizophrenia patients and 20 matched healthy controls. Patients with schizophrenia showed a global reduction in insular gray matter volumes relative to healthy comparison subjects. In a simple comparison of the volumes of each subdivision between the groups, a statistically significant volume reduction in patients with schizophrenia was demonstrated only in the right posterior insula. This study suggests that insular abnormalities in schizophrenia would include anterior as well as posterior parts. Each subdivisional abnormality may impact on different aspects of the pathophysiology and psychopathology of schizophrenia; these relationships should be the focus of future research.

  13. Variational and quasi-variational inequalities in mechanics

    CERN Document Server

    Kravchuk, Alexander S

    2007-01-01

    The essential aim of the present book is to consider a wide set of problems arising in the mathematical modelling of mechanical systems under unilateral constraints. In these investigations elastic and non-elastic deformations, friction and adhesion phenomena are taken into account. All the necessary mathematical tools are given: local boundary value problem formulations, construction of variational equations and inequalities, and the transition to minimization problems, existence and uniqueness theorems, and variational transformations (Friedrichs and Young-Fenchel-Moreau) to dual and saddle-point search problems. Important new results concern contact problems with friction. The Coulomb friction law and some others are considered, in which relative sliding velocities appear. The corresponding quasi-variational inequality is constructed, as well as the appropriate iterative method for its solution. Outlines of the variational approach to non-stationary and dissipative systems and to the construction of the go...

  14. High-Order Spectral Volume Method for 2D Euler Equations

    Science.gov (United States)

    Wang, Z. J.; Zhang, Laiping; Liu, Yen; Kwak, Dochan (Technical Monitor)

    2002-01-01

    The Spectral Volume (SV) method is extended to the 2D Euler equations. The focus of this paper is to study the performance of the SV method on multidimensional non-linear systems. Implementation details including total variation diminishing (TVD) and total variation bounded (TVB) limiters are presented. Solutions with both smooth features and discontinuities are utilized to demonstrate the overall capability of the SV method.

  15. Variational formulation of high performance finite elements: Parametrized variational principles

    Science.gov (United States)

    Felippa, Carlos A.; Militello, Carmello

    1991-01-01

    High performance elements are simple finite elements constructed to deliver engineering accuracy with coarse arbitrary grids. This is part of a series on the variational basis of high-performance elements, with emphasis on those constructed with the free formulation (FF) and assumed natural strain (ANS) methods. Parametrized variational principles that provide a foundation for the FF and ANS methods, as well as for a combination of both are presented.

  16. Statistics, Uncertainty, and Transmitted Variation

    Energy Technology Data Exchange (ETDEWEB)

    Wendelberger, Joanne Roth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-11-05

    The field of Statistics provides methods for modeling and understanding data and making decisions in the presence of uncertainty. When examining response functions, variation present in the input variables will be transmitted via the response function to the output variables. This phenomenon can potentially have significant impacts on the uncertainty associated with results from subsequent analysis. This presentation will examine the concept of transmitted variation, its impact on designed experiments, and a method for identifying and estimating sources of transmitted variation in certain settings.

  17. Image plane sweep volume illumination.

    Science.gov (United States)

    Sundén, Erik; Ynnerman, Anders; Ropinski, Timo

    2011-12-01

    In recent years, many volumetric illumination models have been proposed, which have the potential to simulate advanced lighting effects and thus support improved image comprehension. Although volume ray-casting is widely accepted as the volume rendering technique which achieves the highest image quality, so far no volumetric illumination algorithm has been designed to be directly incorporated into the ray-casting process. In this paper we propose image plane sweep volume illumination (IPSVI), which allows the integration of advanced illumination effects into a GPU-based volume ray-caster by exploiting the plane sweep paradigm. Thus, we are able to reduce the problem complexity and achieve interactive frame rates, while supporting scattering as well as shadowing. Since all illumination computations are performed directly within a single rendering pass, IPSVI does not require any preprocessing nor does it need to store intermediate results within an illumination volume. It therefore has a significantly lower memory footprint than other techniques. This makes IPSVI directly applicable to large data sets. Furthermore, the integration into a GPU-based ray-caster allows for high image quality as well as improved rendering performance by exploiting early ray termination. This paper discusses the theory behind IPSVI, describes its implementation, demonstrates its visual results and provides performance measurements.

  18. Control volume based hydrocephalus research

    Science.gov (United States)

    Cohen, Benjamin; Voorhees, Abram; Wei, Timothy

    2008-11-01

    Hydrocephalus is a disease involving excess amounts of cerebral spinal fluid (CSF) in the brain. Recent research has shown correlations to pulsatility of blood flow through the brain. However, the problem to date has presented as too complex for much more than statistical analysis and understanding. This talk will highlight progress on developing a fundamental control volume approach to studying hydrocephalus. The specific goals are to select physiologically control volume(s), develop conservation equations along with the experimental capabilities to accurately quantify terms in those equations. To this end, an in vitro phantom is used as a simplified model of the human brain. The phantom's design consists of a rigid container filled with a compressible gel. The gel has a hollow spherical cavity representing a ventricle and a cylindrical passage representing the aquaducts. A computer controlled piston pump supplies pulsatile volume fluctuations into and out of the flow phantom. MRI is used to measure fluid velocity, and volume change as functions of time. Independent pressure measurements and flow rate measurements are used to calibrate the MRI data. These data are used as a framework for future work with live patients.

  19. Vasodilation increases pulse pressure variation, mimicking hypovolemic status in rabbits

    Directory of Open Access Journals (Sweden)

    Glauco A Westphal

    2010-01-01

    Full Text Available OBJECTIVE: To test the hypothesis that pulse pressure respiratory variation (PPV amplification, observed in hypovolemia, can also be observed during sodium nitroprusside (SNP-induced vasodilation. INTRODUCTION: PPV is largely used for early identification of cardiac responsiveness, especially when hypovolemia is suspected. PPV results from respiratory variation in transpulmonary blood flow and reflects the left ventricular preload variations during respiratory cycles. Any factor that decreases left ventricular preload can be associated with PPV amplification, as seen in hypovolemia. METHODS: Ten anesthetized and mechanically ventilated rabbits underwent progressive hypotension by either controlled hemorrhage (Group 1 or intravenous SNP infusion (Group 2. Animals in Group 1 (n = 5 had graded hemorrhage induced at 10% steps until 50% of the total volume was bled. Mean arterial pressure (MAP steps were registered and assumed as pressure targets to be reached in Group 2. Group 2 (n = 5 was subjected to a progressive SNP infusion to reach similar pressure targets as those defined in Group 1. Heart rate (HR, systolic pressure variation (SPV and PPV were measured at each MAP step, and the values were compared between the groups. RESULTS: SPV and PPV were similar between the experimental models in all steps (p > 0.16. SPV increased earlier in Group 2. CONCLUSION: Both pharmacologic vasodilation and graded hemorrhage induced PPV amplification similar to that observed in hypovolemia, reinforcing the idea that amplified arterial pressure variation does not necessarily represent hypovolemic status but rather potential cardiovascular responsiveness to fluid infusion.

  20. Free volume and gas permeation in ion-exchanged forms of the Nafion® membrane

    Science.gov (United States)

    Mohamed, Hamdy F. M.; Kobayashi, Y.; Kuroda, C. S.; Ohira, A.

    2010-04-01

    Variations of free volume and gas permeability of the Nafion® membrane upon ion-exchange of H+ with Cs+ or Pt2+ was studied as a function of temperature. Free volume was quantified using the positron annihilation lifetime technique. Our results showed that the free volume (VFV,Ps) of the dried membrane is enlarged by thermal expansion. It was found that the ion-exchange significantly expands the free volume and at the same time decreases the permeabilities of O2 and H2. Good linear correlations between the logarithm of permeabilities of O2 and H2 at different temperatures and 1/VFV,Ps for the ion-exchanged forms of Nafion® in the dried state suggest an important role played by the free volume in gas permeation. Considerable downward deviation of the correlations for the ion-exchanged ionomers from the H+-form suggested the importance of polymer stiffening in gas permeation.

  1. Prediction of free-volume-type correlations in glassy chalcogenides from positron annihilation lifetime measurements

    Energy Technology Data Exchange (ETDEWEB)

    Shpotyuk, O., E-mail: shpotyuk@novas.lviv.ua [Institute of Materials of SRC “Carat”, 212 Stryjska Str., Lviv 79031 (Ukraine); Institute of Physics of Jan Dlugosz University, 13/15 al. Armii Krajowej, Czestcochowa 42200 (Poland); Ingram, A. [Opole University of Technology, 75 Ozimska Str., Opole 45370 (Poland); Shpotyuk, M. [Institute of Materials of SRC “Carat”, 212 Stryjska Str., Lviv 79031 (Ukraine); Lviv Polytechnic National University, 12 Bandery Str., Lviv 79013 (Ukraine); Filipecki, J. [Institute of Physics of Jan Dlugosz University, 13/15 al. Armii Krajowej, Czestcochowa 42200 (Poland)

    2014-11-01

    Highlights: • Decisive role of specific chemical environment in free-volume correlations in glass. • Realistic free volumes in As–S/Se glass are defined by newly modified τ{sub 2}-R formula. • Overestimated void sizes in chalcogenide glass as compared with molecular polymers. - Abstract: A newly modified correlation equation between defect-related positron lifetime determined within two-state trapping model and radius of corresponding free-volume-type defects was proposed to describe compositional variations in atomic-deficient structure of covalent-bonded chalcogenides like binary As–S/Se glasses. Specific chemical environment of free-volume voids around neighboring network-forming polyhedrons was shown to play a decisive role in this correlation, leading to systematically enhanced volumes in comparison with typical molecular substrates, such as polymers.

  2. Variation in temperature during composting of food and vegetable waste.

    Science.gov (United States)

    Yadav, Kunwar D; Mistry, N J; Ganvit, Bhupesh; Pandya, Daxesh

    2013-10-01

    Composting is one of the suitable method for disposal of organic waste and convert it in to organic fertilizer. For effective composting, role of temperature within the composting heap is important. Variation of temperature in the composting heap is the indicator of type of microbial biomass present during the composting. Present study was conducted to find out the minimum volume of waste for effective composting. The present study was conducted in two phases. The first phase of study was conducted to monitor the temperature variation in different volume of composting heap and second phase of study was conducted to study the leachate production in food and vegetable waste. The results of the present study revealed that minimum 80 and 100 kg of food and vegetable waste required maintaining the thermophilic and mesophilic stage. To attain the thermophilic stage the minimum volume should be around 0.5 m3 and minimum height 0.6m. Leachate was produced at initial stage of degradation and it was more in vegetable waste compared to food waste.

  3. Thermodynamic volume of cosmological solitons

    Science.gov (United States)

    Mbarek, Saoussen; Mann, Robert B.

    2017-02-01

    We present explicit expressions of the thermodynamic volume inside and outside the cosmological horizon of Eguchi-Hanson solitons in general odd dimensions. These quantities are calculable and well-defined regardless of whether or not the regularity condition for the soliton is imposed. For the inner case, we show that the reverse isoperimetric inequality is not satisfied for general values of the soliton parameter a, though a narrow range exists for which the inequality does hold. For the outer case, we find that the mass Mout satisfies the maximal mass conjecture and the volume is positive. We also show that, by requiring Mout to yield the mass of dS spacetime when the soliton parameter vanishes, the associated cosmological volume is always positive.

  4. Age estimation from canine volumes.

    Science.gov (United States)

    De Angelis, Danilo; Gaudio, Daniel; Guercini, Nicola; Cipriani, Filippo; Gibelli, Daniele; Caputi, Sergio; Cattaneo, Cristina

    2015-08-01

    Techniques for estimation of biological age are constantly evolving and are finding daily application in the forensic radiology field in cases concerning the estimation of the chronological age of a corpse in order to reconstruct the biological profile, or of a living subject, for example in cases of immigration of people without identity papers from a civil registry. The deposition of teeth secondary dentine and consequent decrease of pulp chamber in size are well known as aging phenomena, and they have been applied to the forensic context by the development of age estimation procedures, such as Kvaal-Solheim and Cameriere methods. The present study takes into consideration canines pulp chamber volume related to the entire teeth volume, with the aim of proposing new regression formulae for age estimation using 91 cone beam computerized scans and a freeware open-source software, in order to permit affordable reproducibility of volumes calculation.

  5. Thermodynamic Volume of Cosmological Solitons

    CERN Document Server

    Mbarek, Saoussen

    2016-01-01

    We present explicit expressions of the thermodynamic volume inside and outside the cosmological horizon of Eguchi-Hanson solitons in general odd dimensions. These quantities are calculable and well-defined regardless of whether or not the regularity condition for the soliton is imposed. For the inner case, we show that the reverse isoperimetric inequality is not satisfied for general values of the soliton parameter $a$, though a narrow range exists for which the inequality does hold. For the outer case, we find that the mass $M_{out}$ satisfies the maximal mass conjecture and the volume is positive. We also show that, by requiring $M_{out}$ to yield the mass of dS spacetime when the soliton parameter vanishes, the associated cosmological volume is always positive.

  6. Dictionary Based Segmentation in Volumes

    DEFF Research Database (Denmark)

    Emerson, Monica Jane; Jespersen, Kristine Munk; Jørgensen, Peter Stanley

    2015-01-01

    We present a method for supervised volumetric segmentation based on a dictionary of small cubes composed of pairs of intensity and label cubes. Intensity cubes are small image volumes where each voxel contains an image intensity. Label cubes are volumes with voxelwise probabilities for a given...... label. The segmentation process is done by matching a cube from the volume, of the same size as the dictionary intensity cubes, to the most similar intensity dictionary cube, and from the associated label cube we get voxel-wise label probabilities. Probabilities from overlapping cubes are averaged...... and hereby we obtain a robust label probability encoding. The dictionary is computed from labeled volumetric image data based on weighted clustering. We experimentally demonstrate our method using two data sets from material science – a phantom data set of a solid oxide fuel cell simulation for detecting...

  7. Variational Approach to Molecular Kinetics.

    Science.gov (United States)

    Nüske, Feliks; Keller, Bettina G; Pérez-Hernández, Guillermo; Mey, Antonia S J S; Noé, Frank

    2014-04-08

    The eigenvalues and eigenvectors of the molecular dynamics propagator (or transfer operator) contain the essential information about the molecular thermodynamics and kinetics. This includes the stationary distribution, the metastable states, and state-to-state transition rates. Here, we present a variational approach for computing these dominant eigenvalues and eigenvectors. This approach is analogous to the variational approach used for computing stationary states in quantum mechanics. A corresponding method of linear variation is formulated. It is shown that the matrices needed for the linear variation method are correlation matrices that can be estimated from simple MD simulations for a given basis set. The method proposed here is thus to first define a basis set able to capture the relevant conformational transitions, then compute the respective correlation matrices, and then to compute their dominant eigenvalues and eigenvectors, thus obtaining the key ingredients of the slow kinetics.

  8. Variational Integrators in Plasma Physics

    CERN Document Server

    Kraus, Michael

    2013-01-01

    Variational integrators are a special kind of geometric discretisation methods applicable to any system of differential equations that obeys a Lagrangian formulation. In this thesis, variational integrators are developed for several important models of plasma physics: guiding centre dynamics (particle dynamics), the Vlasov-Poisson system (kinetic theory), and ideal magnetohydrodynamics (plasma fluid theory). Special attention is given to physical conservation laws like conservation of energy and momentum. Most systems in plasma physics do not possess a Lagrangian formulation to which the variational integrator methodology is directly applicable. Therefore the theory is extended towards nonvariational differential equations by linking it to Ibragimov's theory of integrating factors and adjoint equations. It allows us to find a Lagrangian for all ordinary and partial differential equations and systems thereof. Consequently, the applicability of variational integrators is extended to a much larger family of syst...

  9. Explaining variation in nascent entrepreneurship

    NARCIS (Netherlands)

    A.J. van Stel (André); A.R.M. Wennekers (Sander); P. Reynolds (Paul); A.R. Thurik (Roy)

    2004-01-01

    textabstractThis paper aims at explaining cross-country variation in nascent entrepreneurship. Regression analysis is applied using various explanatory variables derived from three different approaches. We make use of the Global Entrepreneurship Monitor database, including nascent entrepreneurship r

  10. Rockets and People. Volume 1

    Science.gov (United States)

    Chertok, Boris E; Siddiqi, Asif A. (Editor)

    2005-01-01

    Much has been written in the West on the history of the Soviet space program but few Westerners have read direct first-hand accounts of the men and women who were behind the many Russian accomplishments in exploring space.The memoirs of Academician Boris Chertok, translated from the original Russian, fills that gap.Chertok began his career as an electrician in 1930 at an aviation factory near Moscow.Twenty-seven years later, he became deputy to the founding figure of the Soviet space program, the mysterious Chief Designer Sergey Korolev. Chertok s sixty-year-long career and the many successes and failures of the Soviet space program constitute the core of his memoirs, Rockets and People. These writings are spread over four volumes. This is volume I. Academician Chertok not only describes and remembers, but also elicits and extracts profound insights from an epic story about a society s quest to explore the cosmos. In Volume 1, Chertok describes his early years as an engineer and ends with the mission to Germany after the end of World War II when the Soviets captured Nazi missile technology and expertise. Volume 2 takes up the story with the development of the world s first intercontinental ballistic missile ICBM) and ends with the launch of Sputnik and the early Moon probes. In Volume 3, Chertok recollects the great successes of the Soviet space program in the 1960s including the launch of the world s first space voyager Yuriy Gagarin as well as many events connected with the Cold War. Finally, in Volume 4, Chertok meditates at length on the massive Soviet lunar project designed to beat the Americans to the Moon in the 1960s, ending with his remembrances of the Energiya-Buran project.

  11. Variation of fundamental constants: theory

    Science.gov (United States)

    Flambaum, Victor

    2008-05-01

    Theories unifying gravity with other interactions suggest temporal and spatial variation of the fundamental ``constants'' in expanding Universe. There are some hints for the variation of different fundamental constants in quasar absorption spectra and Big Bang nucleosynthesis data. A large number of publications (including atomic clocks) report limits on the variations. We want to study the variation of the main dimensionless parameters of the Standard Model: 1. Fine structure constant alpha (combination of speed of light, electron charge and Plank constant). 2. Ratio of the strong interaction scale (LambdaQCD) to a fundamental mass like electron mass or quark mass which are proportional to Higgs vacuum expectation value. The proton mass is propotional to LambdaQCD, therefore, the proton-to-electron mass ratio comes into this second category. We performed necessary atomic, nuclear and QCD calculations needed to study variation of the fundamental constants using the Big Bang Nucleosynthsis, quasar spectra, Oklo natural nuclear reactor and atomic clock data. The relative effects of the variation may be enhanced in transitions between narrow close levels in atoms, molecules and nuclei. If one will study an enhanced effect, the relative value of systematic effects (which are not enhanced) may be much smaller. Note also that the absolute magnitude of the variation effects in nuclei (e.g. in very narrow 7 eV transition in 229Th) may be 5 orders of magnitude larger than in atoms. A different possibility of enhancement comes from the inversion transitions in molecules where splitting between the levels is due to the quantum tunneling amplitude which has strong, exponential dependence on the electron to proton mass ratio. Our study of NH3 quasar spectra has already given the best limit on the variation of electron to proton mass ratio.

  12. 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.

  13. Scan-based volume animation driven by locally adaptive articulated registrations.

    Science.gov (United States)

    Rhee, Taehyun; Lewis, J P; Neumann, Ulrich; Nayak, Krishna S

    2011-03-01

    This paper describes a complete system to create anatomically accurate example-based volume deformation and animation of articulated body regions, starting from multiple in vivo volume scans of a specific individual. In order to solve the correspondence problem across volume scans, a template volume is registered to each sample. The wide range of pose variations is first approximated by volume blend deformation (VBD), providing proper initialization of the articulated subject in different poses. A novel registration method is presented to efficiently reduce the computation cost while avoiding strong local minima inherent in complex articulated body volume registration. The algorithm highly constrains the degrees of freedom and search space involved in the nonlinear optimization, using hierarchical volume structures and locally constrained deformation based on the biharmonic clamped spline. Our registration step establishes a correspondence across scans, allowing a data-driven deformation approach in the volume domain. The results provide an occlusion-free person-specific 3D human body model, asymptotically accurate inner tissue deformations, and realistic volume animation of articulated movements driven by standard joint control estimated from the actual skeleton. Our approach also addresses the practical issues arising in using scans from living subjects. The robustness of our algorithms is tested by their applications on the hand, probably the most complex articulated region in the body, and the knee, a frequent subject area for medical imaging due to injuries.

  14. The Role of MRSI in Target Volume Definition for Radiation Therapy of Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Mostafa Robatjazi

    2011-09-01

    Full Text Available Introduction: Recently, magnetic resonance spectroscopic imaging (MRSI, as a functional imaging method, has been used for clinical target volume definition. In this study, we used this method to define the target volume in prostate radiotherapy. Material and Method: In this study, we used images of 20 prostate cancer cases. MRSI and MRI images were fused with CT images. Then, treatment planning was preformed for each patient using three methods: CT, CT+MRI and CT+MRSI planning. Results: The volumes of MRICTV and MRIPTV were on average 12.83% and 8.97% lower than the corresponding CTCTV and CTPTV volumes, respectively. For MRSI, the CTV and PTV volumes were 21% and 27.41% greater than the corresponding CT-based volumes. Maximum dose to rectum showed a 0.58% increase in MRSI relative to CT, and 1.09% reduction in MRI relative to CT. Maximum dose variation in femoral heads showed a 5.4% increase in MRSI relative to CT and 0.67% reduction in MRI relative to CT. Discussion and Conclusion: Application of MRSI for target volume definition of prostate cancer leads to an increase in this volume in comparison to CT planning alone. In this imaging technique, protocol and resolution should be considered to determine the target volume exactly.

  15. MPCV Exercise Operational Volume Analysis

    Science.gov (United States)

    Godfrey, A.; Humphreys, B.; Funk, J.; Perusek, G.; Lewandowski, B. E.

    2017-01-01

    In order to minimize the loss of bone and muscle mass during spaceflight, the Multi-purpose Crew Vehicle (MPCV) will include an exercise device and enough free space within the cabin for astronauts to use the device effectively. The NASA Digital Astronaut Project (DAP) has been tasked with using computational modeling to aid in determining whether or not the available operational volume is sufficient for in-flight exercise.Motion capture data was acquired using a 12-camera Smart DX system (BTS Bioengineering, Brooklyn, NY), while exercisers performed 9 resistive exercises without volume restrictions in a 1g environment. Data were collected from two male subjects, one being in the 99th percentile of height and the other in the 50th percentile of height, using between 25 and 60 motion capture markers. Motion capture data was also recorded as a third subject, also near the 50th percentile in height, performed aerobic rowing during a parabolic flight. A motion capture system and algorithms developed previously and presented at last years HRP-IWS were utilized to collect and process the data from the parabolic flight [1]. These motions were applied to a scaled version of a biomechanical model within the biomechanical modeling software OpenSim [2], and the volume sweeps of the motions were visually assessed against an imported CAD model of the operational volume. Further numerical analysis was performed using Matlab (Mathworks, Natick, MA) and the OpenSim API. This analysis determined the location of every marker in space over the duration of the exercise motion, and the distance of each marker to the nearest surface of the volume. Containment of the exercise motions within the operational volume was determined on a per-exercise and per-subject basis. The orientation of the exerciser and the angle of the footplate were two important factors upon which containment was dependent. Regions where the exercise motion exceeds the bounds of the operational volume have been

  16. Large volume cryogenic silicon detectors

    Energy Technology Data Exchange (ETDEWEB)

    Braggio, C. [Dipartimento di Fisica, Universita di Padova, via Marzolo 8, 35131 Padova (Italy); Boscardin, M. [Fondazione Bruno Kessler (FBK), via Sommarive 18, I-38100 Povo (Italy); Bressi, G. [INFN sez. di Pavia, via Bassi 6, 27100 Pavia (Italy); Carugno, G.; Corti, D. [INFN sez. di Padova, via Marzolo 8, 35131 Padova (Italy); Galeazzi, G. [INFN lab. naz. Legnaro, viale dell' Universita 2, 35020 Legnaro (Italy); Zorzi, N. [Fondazione Bruno Kessler (FBK), via Sommarive 18, I-38100 Povo (Italy)

    2009-12-15

    We present preliminary measurements for the development of a large volume silicon detector to detect low energy and low rate energy depositions. The tested detector is a one cm-thick silicon PIN diode with an active volume of 31 cm{sup 3}, cooled to the liquid helium temperature to obtain depletion from thermally-generated free carriers. A thorough study has been done to show that effects of charge trapping during drift disappears at a bias field value of the order of 100V/cm.

  17. Foaming volume and foam stability

    Science.gov (United States)

    Ross, Sydney

    1947-01-01

    A method of measuring foaming volume is described and investigated to establish the critical factors in its operation. Data on foaming volumes and foam stabilities are given for a series of hydrocarbons and for a range of concentrations of aqueous ethylene-glycol solutions. It is shown that the amount of foam formed depends on the machinery of its production as well as on properties of the liquid, whereas the stability of the foam produced, within specified mechanical limitations, is primarily a function of the liquid.

  18. Disorders of erythrocyte volume homeostasis.

    Science.gov (United States)

    Glogowska, E; Gallagher, P G

    2015-05-01

    Inherited disorders of erythrocyte volume homeostasis are a heterogeneous group of rare disorders with phenotypes ranging from dehydrated to overhydrated erythrocytes. Clinical, laboratory, physiologic, and genetic heterogeneities characterize this group of disorders. A series of recent reports have provided novel insights into our understanding of the genetic bases underlying some of these disorders of red cell volume regulation. This report reviews this progress in understanding determinants that influence erythrocyte hydration and how they have yielded a better understanding of the pathways that influence cellular water and solute homeostasis.

  19. 36 CFR 223.36 - Volume determination.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Volume determination. 223.36... Volume determination. (a) Timber sale contracts may provide for volume determination by scaling... the contract or permit provides for the determination of volume by tree measurement and the timber has...

  20. 40 CFR 791.48 - Production volume.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 31 2010-07-01 2010-07-01 true Production volume. 791.48 Section 791... (CONTINUED) DATA REIMBURSEMENT Basis for Proposed Order § 791.48 Production volume. (a) Production volume.... (b) For the purpose of determining fair reimbursement shares, production volume shall include amounts...

  1. The relative volume growth of minimal submanifolds

    DEFF Research Database (Denmark)

    Markvorsen, Steen; Palmer, V.

    2002-01-01

    The volume growth of certain well-defined subsets of minimal submanifolds in riemannian spaces are compared with the volume growth of balls and spheres ill space forms of constant curvature.......The volume growth of certain well-defined subsets of minimal submanifolds in riemannian spaces are compared with the volume growth of balls and spheres ill space forms of constant curvature....

  2. Variational integrators for electric circuits

    Energy Technology Data Exchange (ETDEWEB)

    Ober-Blöbaum, Sina, E-mail: sinaob@math.upb.de [Computational Dynamics and Optimal Control, University of Paderborn (Germany); Tao, Molei [Courant Institute of Mathematical Sciences, New York University (United States); Cheng, Mulin [Applied and Computational Mathematics, California Institute of Technology (United States); Owhadi, Houman; Marsden, Jerrold E. [Control and Dynamical Systems, California Institute of Technology (United States); Applied and Computational Mathematics, California Institute of Technology (United States)

    2013-06-01

    In this contribution, we develop a variational integrator for the simulation of (stochastic and multiscale) electric circuits. When considering the dynamics of an electric circuit, one is faced with three special situations: 1. The system involves external (control) forcing through external (controlled) voltage sources and resistors. 2. The system is constrained via the Kirchhoff current (KCL) and voltage laws (KVL). 3. The Lagrangian is degenerate. Based on a geometric setting, an appropriate variational formulation is presented to model the circuit from which the equations of motion are derived. A time-discrete variational formulation provides an iteration scheme for the simulation of the electric circuit. Dependent on the discretization, the intrinsic degeneracy of the system can be canceled for the discrete variational scheme. In this way, a variational integrator is constructed that gains several advantages compared to standard integration tools for circuits; in particular, a comparison to BDF methods (which are usually the method of choice for the simulation of electric circuits) shows that even for simple LCR circuits, a better energy behavior and frequency spectrum preservation can be observed using the developed variational integrator.

  3. Nutrient Deprivation Induces Property Variations in Spider Gluey Silk

    Science.gov (United States)

    Blamires, Sean J.; Sahni, Vasav; Dhinojwala, Ali; Blackledge, Todd A.; Tso, I-Min

    2014-01-01

    Understanding the mechanisms facilitating property variability in biological adhesives may promote biomimetic innovations. Spider gluey silks such as the spiral threads in orb webs and the gumfoot threads in cobwebs, both of which comprise of an axial thread coated by glue, are biological adhesives that have variable physical and chemical properties. Studies show that the physical and chemical properties of orb web gluey threads change when spiders are deprived of food. It is, however, unknown whether gumfoot threads undergo similar property variations when under nutritional stress. Here we tested whether protein deprivation induces similar variations in spiral and gumfoot thread morphology and stickiness. We manipulated protein intake for the orb web spider Nephila clavipes and the cobweb spider Latrodectus hesperus and measured the diameter, glue droplet volume, number of droplets per mm, axial thread width, thread stickiness and adhesive energy of their gluey silks. We found that the gluey silks of both species were stickier when the spiders were deprived of protein than when the spiders were fed protein. In N. clavipes a concomitant increase in glue droplet volume was found. Load-extension curves showed that protein deprivation induced glue property variations independent of the axial thread extensions in both species. We predicted that changes in salt composition of the glues were primarily responsible for the changes in stickiness of the silks, although changes in axial thread properties might also contribute. We, additionally, showed that N. clavipes' glue changes color under protein deprivation, probably as a consequence of changes to its biochemical composition. PMID:24523902

  4. Nutrient deprivation induces property variations in spider gluey silk.

    Science.gov (United States)

    Blamires, Sean J; Sahni, Vasav; Dhinojwala, Ali; Blackledge, Todd A; Tso, I-Min

    2014-01-01

    Understanding the mechanisms facilitating property variability in biological adhesives may promote biomimetic innovations. Spider gluey silks such as the spiral threads in orb webs and the gumfoot threads in cobwebs, both of which comprise of an axial thread coated by glue, are biological adhesives that have variable physical and chemical properties. Studies show that the physical and chemical properties of orb web gluey threads change when spiders are deprived of food. It is, however, unknown whether gumfoot threads undergo similar property variations when under nutritional stress. Here we tested whether protein deprivation induces similar variations in spiral and gumfoot thread morphology and stickiness. We manipulated protein intake for the orb web spider Nephila clavipes and the cobweb spider Latrodectus hesperus and measured the diameter, glue droplet volume, number of droplets per mm, axial thread width, thread stickiness and adhesive energy of their gluey silks. We found that the gluey silks of both species were stickier when the spiders were deprived of protein than when the spiders were fed protein. In N. clavipes a concomitant increase in glue droplet volume was found. Load-extension curves showed that protein deprivation induced glue property variations independent of the axial thread extensions in both species. We predicted that changes in salt composition of the glues were primarily responsible for the changes in stickiness of the silks, although changes in axial thread properties might also contribute. We, additionally, showed that N. clavipes' glue changes color under protein deprivation, probably as a consequence of changes to its biochemical composition.

  5. Variations in the Contouring of Organs at Risk: Test Case From a Patient With Oropharyngeal Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Nelms, Benjamin E., E-mail: alpha@canislupusllc.com [Canis Lupus LLC, Merrimac, WI (United States); Tome, Wolfgang A. [Department of Human Oncology, University of Wisconsin, Madison, WI (United States); Robinson, Greg [Radiation Oncology Resources, Goshen, IN (United States); Wheeler, James [Department of Radiation Oncology, Goshen Health System Goshen, IN (United States)

    2012-01-01

    Purpose: Anatomy contouring is critical in radiation therapy. Inaccuracy and variation in defining critical volumes will affect everything downstream: treatment planning, dose-volume histogram analysis, and contour-based visual guidance used in image-guided radiation therapy. This study quantified: (1) variation in the contouring of organs at risk (OAR) in a clinical test case and (2) corresponding effects on dosimetric metrics of highly conformal plans. Methods and Materials: A common CT data set with predefined targets from a patient with oropharyngeal cancer was provided to a population of clinics, which were asked to (1) contour OARs and (2) design an intensity-modulated radiation therapy plan. Thirty-two acceptable plans were submitted as DICOM RT data sets, each generated by a different clinical team. Using those data sets, we quantified: (1) the OAR contouring variation and (2) the impact this variation has on dosimetric metrics. New technologies were employed, including a software tool to quantify three-dimensional structure comparisons. Results: There was significant interclinician variation in OAR contouring. The degree of variation is organ-dependent. We found substantial dose differences resulting strictly from contouring variation (differences ranging from -289% to 56% for mean OAR dose; -22% to 35% for maximum dose). However, there appears to be a threshold in the OAR comparison metric beyond which the dose differences stabilize. Conclusions: The effects of interclinician variation in contouring organs-at-risk in the head and neck can be large and are organ-specific. Physicians need to be aware of the effect that variation in OAR contouring can play on the final treatment plan and not restrict their focus only to the target volumes.

  6. Emergent Chemical Behavior in Variable-Volume Protocells

    Science.gov (United States)

    Shirt-Ediss, Ben; Solé, Ricard V.; Ruiz-Mirazo, Kepa

    2015-01-01

    Artificial protocellular compartments and lipid vesicles have been used as model systems to understand the origins and requirements for early cells, as well as to design encapsulated reactors for biotechnology. One prominent feature of vesicles is the semi-permeable nature of their membranes, able to support passive diffusion of individual solute species into/out of the compartment, in addition to an osmotic water flow in the opposite direction to the net solute concentration gradient. Crucially, this water flow affects the internal aqueous volume of the vesicle in response to osmotic imbalances, in particular those created by ongoing reactions within the system. In this theoretical study, we pay attention to this often overlooked aspect and show, via the use of a simple semi-spatial vesicle reactor model, that a changing solvent volume introduces interesting non-linearities into an encapsulated chemistry. Focusing on bistability, we demonstrate how a changing volume compartment can degenerate existing bistable reactions, but also promote emergent bistability from very simple reactions, which are not bistable in bulk conditions. One particularly remarkable effect is that two or more chemically-independent reactions, with mutually exclusive reaction kinetics, are able to couple their dynamics through the variation of solvent volume inside the vesicle. Our results suggest that other chemical innovations should be expected when more realistic and active properties of protocellular compartments are taken into account. PMID:25590570

  7. Emergent chemical behavior in variable-volume protocells.

    Science.gov (United States)

    Shirt-Ediss, Ben; Solé, Ricard V; Ruiz-Mirazo, Kepa

    2015-01-13

    Artificial protocellular compartments and lipid vesicles have been used as model systems to understand the origins and requirements for early cells, as well as to design encapsulated reactors for biotechnology. One prominent feature of vesicles is the semi-permeable nature of their membranes, able to support passive diffusion of individual solute species into/out of the compartment, in addition to an osmotic water flow in the opposite direction to the net solute concentration gradient. Crucially, this water flow affects the internal aqueous volume of the vesicle in response to osmotic imbalances, in particular those created by ongoing reactions within the system. In this theoretical study, we pay attention to this often overlooked aspect and show, via the use of a simple semi-spatial vesicle reactor model, that a changing solvent volume introduces interesting non-linearities into an encapsulated chemistry. Focusing on bistability, we demonstrate how a changing volume compartment can degenerate existing bistable reactions, but also promote emergent bistability from very simple reactions, which are not bistable in bulk conditions. One particularly remarkable effect is that two or more chemically-independent reactions, with mutually exclusive reaction kinetics, are able to couple their dynamics through the variation of solvent volume inside the vesicle. Our results suggest that other chemical innovations should be expected when more realistic and active properties of protocellular compartments are taken into account.

  8. Emergent Chemical Behavior in Variable-Volume Protocells

    Directory of Open Access Journals (Sweden)

    Ben Shirt-Ediss

    2015-01-01

    Full Text Available Artificial protocellular compartments and lipid vesicles have been used as model systems to understand the origins and requirements for early cells, as well as to design encapsulated reactors for biotechnology. One prominent feature of vesicles is the semi-permeable nature of their membranes, able to support passive diffusion of individual solute species into/out of the compartment, in addition to an osmotic water flow in the opposite direction to the net solute concentration gradient. Crucially, this water flow affects the internal aqueous volume of the vesicle in response to osmotic imbalances, in particular those created by ongoing reactions within the system. In this theoretical study, we pay attention to this often overlooked aspect and show, via the use of a simple semi-spatial vesicle reactor model, that a changing solvent volume introduces interesting non-linearities into an encapsulated chemistry. Focusing on bistability, we demonstrate how a changing volume compartment can degenerate existing bistable reactions, but also promote emergent bistability from very simple reactions, which are not bistable in bulk conditions. One particularly remarkable effect is that two or more chemically-independent reactions, with mutually exclusive reaction kinetics, are able to couple their dynamics through the variation of solvent volume inside the vesicle. Our results suggest that other chemical innovations should be expected when more realistic and active properties of protocellular compartments are taken into account.

  9. Is there much variation in variation? Revisiting statistics of small area variation in health services research

    Directory of Open Access Journals (Sweden)

    Ibáñez Berta

    2009-04-01

    Full Text Available Abstract Background The importance of Small Area Variation Analysis for policy-making contrasts with the scarcity of work on the validity of the statistics used in these studies. Our study aims at 1 determining whether variation in utilization rates between health areas is higher than would be expected by chance, 2 estimating the statistical power of the variation statistics; and 3 evaluating the ability of different statistics to compare the variability among different procedures regardless of their rates. Methods Parametric bootstrap techniques were used to derive the empirical distribution for each statistic under the hypothesis of homogeneity across areas. Non-parametric procedures were used to analyze the empirical distribution for the observed statistics and compare the results in six situations (low/medium/high utilization rates and low/high variability. A small scale simulation study was conducted to assess the capacity of each statistic to discriminate between different scenarios with different degrees of variation. Results Bootstrap techniques proved to be good at quantifying the difference between the null hypothesis and the variation observed in each situation, and to construct reliable tests and confidence intervals for each of the variation statistics analyzed. Although the good performance of Systematic Component of Variation (SCV, Empirical Bayes (EB statistic shows better behaviour under the null hypothesis, it is able to detect variability if present, it is not influenced by the procedure rate and it is best able to discriminate between different degrees of heterogeneity. Conclusion The EB statistics seems to be a good alternative to more conventional statistics used in small-area variation analysis in health service research because of its robustness.

  10. Particle multiplicities and particle ratios in excluded volume model

    CERN Document Server

    Mishra, M

    2008-01-01

    One of the most surprising results is to find that a consistent description of all the experimental results on particle multiplicities and particle ratios obtained from the lowest AGS to the highest RHIC energies is possible within the framework of a thermal statistical model. We propose here a thermodynamically consistent excluded-volume model involving an interacting multi-component hadron gas. We find that the energy dependence of the total multiplicities of strange and non-strange hadrons obtained in this model agrees closely with the experimental results. It indicates that the freeze out volume of the fireball is uniformly the same for all the particles. We have also compared the variation of the particle ratios such as $/, /, K^{-}/K^{+}, \\bar{p}/p, \\bar{\\Lambda}/\\Lambda, \\bar{\\Xi}/\\Xi, \\bar{\\Omega}/\\Omega, /, /, /$ and $/$ with respect to the center-of-mass energy as predicted by our model with the recent experimental data.

  11. LLE Review Quarterly Report (April-June 2001). Volume 87

    Energy Technology Data Exchange (ETDEWEB)

    Hinterman, Thomas H. [Univ. of Rochester, NY (United States). Lab. for Laser Energetics

    2001-06-01

    This volume of the LLE Review, covering April–June 2001, features ''A Self-Calibrating, Multichannel Streak Camera for Inertial Confinement Fusion Applications'' by Dr. W. R. Donaldson, R. Boni, R. L. Keck, and P. A. Jaanimagi. This article (p. 109) describes the 60-beam streak camera system used on OMEGA and focuses on the hardware and software calibration techniques that maximize its utility. The system can diagnose each of the beams on every target shot and can measure beam energies with 8% accuracy and timing at 7 ps rms. Beam-to-beam power variations of less than 5% can be detected. Other articles in this volume are: Evolution of Shell Nonuniformities Near Peak Compression of a Spherical Implosion; Multibeam Stimulated Brillouin Scattering from Hot Solid-Target Plasmas; Hot-Electron Effect in Superconductors and Is Applications for Radiation Sensors; and, Scaling Law for Marginal Ignition.

  12. PATRAM '80. Proceedings. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Huebner, H.W. (ed.)

    1980-01-01

    Volume 2 contains papers from the following sessions: Safeguards-Related Problems; Neutronics and Criticality; Operations and Systems Experience II; Plutonium Systems; Intermediate Storage in Casks; Operations and Systems Planning; Institutional Issues; Structural and Thermal Evaluation I; Poster Session B; Extended Testing I; Structural and Thermal Evaluation II; Extended Testing II; and Emergency Preparedness and Response. Individual papers were processed. (LM)

  13. Moment Maps and Equivariant Volumes

    Institute of Scientific and Technical Information of China (English)

    Alberto DELLA VEDOVA; Roberto PAOLETTI

    2007-01-01

    The study of the volume of big line bundles on a complex projective manifold M has been one of the main veins in the recent interest in the asymptotic properties of linear series. In this article,we consider an equivariant version of this problem, in the presence of a linear action of a reductive group on M.

  14. The African Experience. Volume I: Syllabus Lectures; Volume II: Bibliographic References; Volume IIIA: Introductory Essays; Volume IIIB: Introductory Essays.

    Science.gov (United States)

    Paden, John N.; Soja, Edward W.

    In response to demands for more and better teaching about Africa in American higher education, the US Office of Education requested that the Program of African Studies at Northwestern University generate a set of teaching materials which could be used in introductory undergraduate courses. Included in these volumes, these materials provide…

  15. Octree-based Volume Sculpting

    DEFF Research Database (Denmark)

    Bærentzen, Jakob Andreas

    1998-01-01

    A volume sculpting system is presented. The system provides tools for interactive editing of a voxel raster that is stored in an octree data structure. Two different modes of sculpting are supported: Sculpting by adding and subtracting solids, and sculpting with tools that are based on a spray ca...... metaphor. The possibility of extending the method to support multiresolution sculpting is discussed....

  16. Plasma volume in acute hypoxia

    DEFF Research Database (Denmark)

    Poulsen, T D; Klausen, T; Richalet, J P

    1998-01-01

    Exposure to acute hypoxia is associated with changes in body fluid homeostasis and plasma volume (PV). This study compared a dye dilution technique using Evans' blue (PV[Evans']) with a carbon monoxide (CO) rebreathing method (PV[CO]) for measurements of PV in ten normal subjects at sea level...

  17. Archives of ALGA. Volume 2

    OpenAIRE

    2005-01-01

    Volume 2 contains 3 articles: Ilir Berisha, Translation of Bäcklunds paper ”Surfaces of constant negative curvature”; Johan Erlandsson, "Survey of mathematical models in biology from point of view of Lie group analysis"; Niklas Säfström, "Group analysis of a tumour growth model"

  18. Reading Authentic Polish, Volume II.

    Science.gov (United States)

    Walczynski, Waldemar

    The second volume on reading authentic Polish is the continuation of a supplementary textbook to be used either in the classroom or in independent study. The materials included in it are unaltered authentic texts from Polish newspapers, magazines, and other mass media that provide exposure to the context and format of everyday reading matter. The…

  19. Editorial, Volume 5, Issue 1

    Directory of Open Access Journals (Sweden)

    Kristy L. Archuleta

    2014-08-01

    Full Text Available Welcome to Volume 5, Issue 1 of the Journal of Financial Therapy! In this issue, four scholarly papers are presented along with two profiles and a book review. These four papers address very important issues, such as mental health therapists’ competency in working with financial issues, financial stress of college students, parental messages about money, and financial advice media.

  20. Modern Chemical Technology, Volume 5.

    Science.gov (United States)

    Pecsok, Robert L., Ed.; Chapman, Kenneth, Ed.

    This volume contains chapters 26-31 for the American Chemical Society (ACS) "Modern Chemical Technology" (ChemTeC) instructional material intended to prepare chemical technologists. Chapter 26 reviews oxidation and reduction, including applications in titrations with potassium permanganate and iodometry. Coordination compounds are…

  1. Pragmatics & Language Learning. Volume 12

    Science.gov (United States)

    Kasper, Gabriele, Ed.; Nguyen, Hanh thi, Ed.; Yoshimi, Dina Rudolph, Ed.; Yoshioka, Jim K., Ed.

    2010-01-01

    This volume examines the organization of second language and multilingual speakers' talk and pragmatic knowledge across a range of naturalistic and experimental activities. Based on data collected on Danish, English, Hawai'i Creole, Indonesian, and Japanese as target languages, the contributions explore the nexus of pragmatic knowledge,…

  2. Modern Chemical Technology, Volume 9.

    Science.gov (United States)

    Pecsok, Robert L.; Chapman, Kenneth

    This volume is one of the series for the Chemical Technician Curriculum Project (ChemTeC) of the American Chemical Society funded by the National Science Foundation. It consists of discussions, exercises, and experiments on the following topics: ion exchange, electrphoresis, dialysis, electrochemistry, corrosion, electrolytic cells, coulometry,…

  3. PATRAM '80. Proceedings. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Huebner, H.W. (ed.)

    1980-01-01

    Volume 1 contains papers from the following sessions: Plenary Session; Regulations, Licensing and Standards; LMFBR Systems Concepts; Risk/Safety Assessment I; Systems and Package Design; US Institutional Issues; Risk/Safety Assessment II; Leakage, Leak Rate and Seals; Poster Session A; Operations and Systems Experience I; Manufacturing Processes and Materials; and Quality Assurance and Maintenance. Individual papers were processed. (LM)

  4. Dictionary Based Segmentation in Volumes

    DEFF Research Database (Denmark)

    Emerson, Monica Jane; Jespersen, Kristine Munk; Jørgensen, Peter Stanley

    Method for supervised segmentation of volumetric data. The method is trained from manual annotations, and these annotations make the method very flexible, which we demonstrate in our experiments. Our method infers label information locally by matching the pattern in a neighborhood around a voxel ...... to a dictionary, and hereby accounts for the volume texture....

  5. Variation of Quench Propagation Velocities in YBCO Cables

    CERN Document Server

    Härö, E.; Stenvall, A.; 10.1007/s10948-015-2976-y

    2015-01-01

    changes during the quench. Due to the large temperature margin between the operation and the current sharing temperatures, the normal zone does not propagate with the temperature front. This means that the temperature will rise in a considerably larger volume when compared to the quenched volume. Thus, the evolution of the temperature distribution below current sharing temperature Tcs after the quench onset affects the normal zone propagation velocity in HTS more than in LTS coils. This can be seen as an acceleration of the quench propagation velocities while the quench evolves when margin to Tcs is high. In this paper we scrutinize quench propagation in a stack of YBCO cables with an in-house finite element method software which solves the heat diffusion equation. We compute the longitudinal and transverse normal zone propagation velocities at various distances from the hot spot to demonstrate the distance-variation...

  6. A CO2 laser based two-volume collective scattering instrument for spatially localized turbulence measurements

    DEFF Research Database (Denmark)

    Saffman, Mark; Zoletnik, S.; Basse, Nils Plesner

    2001-01-01

    We describe and demonstrate a two-volume collective scattering system for localized measurements of plasma turbulence. The finite crossfield correlation length of plasma turbulence combined with spatial variations in the magnetic field direction are used to obtain spatially localized turbulence...

  7. Technical Note: Stored grain volume measurement using a low density point cloud

    Science.gov (United States)

    The mass of stored grain is often determined from volume measurements by crop insurers, government auditors, and stored grain managers conducting inventories. Recent increases in bin size have accentuated the difficulty of accounting for irregularities and variations in surface conditions in calcula...

  8. Socialization of prosocial behavior: Gender differences in the mediating role of child brain volume

    NARCIS (Netherlands)

    R. Kok (Renske); P.J. Prinzie (Peter); M.J. Bakermans-Kranenburg (Marian); F.C. Verhulst (Frank); T.J.H. White (Tonya); H.W. Tiemeier (Henning); M.H. van IJzendoorn (Marinus)

    2017-01-01

    textabstractEvidence has been accumulating for the impact of normal variation in caregiving quality on brain morphology in children, but the question remains whether differences in brain volume related to early caregiving translate to behavioral implications. In this longitudinal population-based

  9. The Role of Variation in Lexicography.

    Science.gov (United States)

    Lucas, Ceil

    2003-01-01

    Explores the relationship between lexicography and variation in both spoken languages and sign languages. Examines the function of dictionaries and discusses the nature of linguistic variation, using an example of lexical variation in American Sign Language. (Author/VWL)

  10. Variations on the Zilch Cycle

    Science.gov (United States)

    Binder, P.-M.; Tanoue, C. K. S.

    2013-01-01

    Thermo dynamic cycles in introductory physics courses are usually made up from a small number of permutations of isothermal, adiabatic, and constant-pressure and volume quasistatic strokes, with the working fluid usually being an ideal gas. Among them we find the Carnot, Stirling, Otto, Diesel, and Joule-Brayton cycles; in more advanced courses,…

  11. 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.

  12. Device overlay method for high volume manufacturing

    Science.gov (United States)

    Lee, Honggoo; Han, Sangjun; Kim, Youngsik; Kim, Myoungsoo; Heo, Hoyoung; Jeon, Sanghuck; Choi, DongSub; Nabeth, Jeremy; Brinster, Irina; Pierson, Bill; Robinson, John C.

    2016-03-01

    Advancing technology nodes with smaller process margins require improved photolithography overlay control. Overlay control at develop inspection (DI) based on optical metrology targets is well established in semiconductor manufacturing. Advances in target design and metrology technology have enabled significant improvements in overlay precision and accuracy. One approach to represent in-die on-device as-etched overlay is to measure at final inspection (FI) with a scanning electron microscope (SEM). Disadvantages to this approach include inability to rework, limited layer coverage due to lack of transparency, and higher cost of ownership (CoO). A hybrid approach is investigated in this report whereby infrequent DI/FI bias is characterized and the results are used to compensate the frequent DI overlay results. The bias characterization is done on an infrequent basis, either based on time or triggered from change points. On a per-device and per-layer basis, the optical target overlay at DI is compared with SEM on-device overlay at FI. The bias characterization results are validated and tracked for use in compensating the DI APC controller. Results of the DI/FI bias characterization and sources of variation are presented, as well as the impact on the DI correctables feeding the APC system. Implementation details in a high volume manufacturing (HVM) wafer fab will be reviewed. Finally future directions of the investigation will be discussed.

  13. Les variations diasystématiques et leurs interdépendances dans les langues romanes

    DEFF Research Database (Denmark)

    Le présent volume contient un choix des actes du Colloque DIA II sur la variation linguistique dans les langues romanes. Ce colloque organisé par l'Université de Copenhague en collaboration avec l’Académie Royale des Sciences et Belles-lettres du Danemark du 19 au 21 novembre 2012 était consacré ...

  14. The influence of speed and interval variation of serial stimuli on physiological change

    NARCIS (Netherlands)

    Kok, A.

    1970-01-01

    Studied changes in heart rate (HR), heart rate variability (HRV), blood volume pulse (BVP), respiration speed (RS), and alpha rhythm (AR) under conditions of the variation of the speed and intervals of auditory stimuli in a serial 2-choice response task. The analysis of variance of the percentage sc

  15. Variational methods in molecular modeling

    CERN Document Server

    2017-01-01

    This book presents tutorial overviews for many applications of variational methods to molecular modeling. Topics discussed include the Gibbs-Bogoliubov-Feynman variational principle, square-gradient models, classical density functional theories, self-consistent-field theories, phase-field methods, Ginzburg-Landau and Helfrich-type phenomenological models, dynamical density functional theory, and variational Monte Carlo methods. Illustrative examples are given to facilitate understanding of the basic concepts and quantitative prediction of the properties and rich behavior of diverse many-body systems ranging from inhomogeneous fluids, electrolytes and ionic liquids in micropores, colloidal dispersions, liquid crystals, polymer blends, lipid membranes, microemulsions, magnetic materials and high-temperature superconductors. All chapters are written by leading experts in the field and illustrated with tutorial examples for their practical applications to specific subjects. With emphasis placed on physical unders...

  16. Antigenic Variation in Bacterial Pathogens.

    Science.gov (United States)

    Palmer, Guy H; Bankhead, Troy; Seifert, H Steven

    2016-02-01

    Antigenic variation is a strategy used by a broad diversity of microbial pathogens to persist within the mammalian host. Whereas viruses make use of a minimal proofreading capacity combined with large amounts of progeny to use random mutation for variant generation, antigenically variant bacteria have evolved mechanisms which use a stable genome, which aids in protecting the fitness of the progeny. Here, three well-characterized and highly antigenically variant bacterial pathogens are discussed: Anaplasma, Borrelia, and Neisseria. These three pathogens display a variety of mechanisms used to create the structural and antigenic variation needed for immune escape and long-term persistence. Intrahost antigenic variation is the focus; however, the role of these immune escape mechanisms at the population level is also presented.

  17. Variational Methods for Biomolecular Modeling

    CERN Document Server

    Wei, Guo-Wei

    2016-01-01

    Structure, function and dynamics of many biomolecular systems can be characterized by the energetic variational principle and the corresponding systems of partial differential equations (PDEs). This principle allows us to focus on the identification of essential energetic components, the optimal parametrization of energies, and the efficient computational implementation of energy variation or minimization. Given the fact that complex biomolecular systems are structurally non-uniform and their interactions occur through contact interfaces, their free energies are associated with various interfaces as well, such as solute-solvent interface, molecular binding interface, lipid domain interface, and membrane surfaces. This fact motivates the inclusion of interface geometry, particular its curvatures, to the parametrization of free energies. Applications of such interface geometry based energetic variational principles are illustrated through three concrete topics: the multiscale modeling of biomolecular electrosta...

  18. Solid mechanics a variational approach

    CERN Document Server

    Dym, Clive L

    2013-01-01

    Solid Mechanics: A Variational Approach, Augmented Edition presents a lucid and thoroughly developed approach to solid mechanics for students engaged in the study of elastic structures not seen in other texts currently on the market. This work offers a clear and carefully prepared exposition of variational techniques as they are applied to solid mechanics. Unlike other books in this field, Dym and Shames treat all the necessary theory needed for the study of solid mechanics and include extensive applications. Of particular note is the variational approach used in developing consistent structural theories and in obtaining exact and approximate solutions for many problems.  Based on both semester and year-long courses taught to undergraduate seniors and graduate students, this text is geared for programs in aeronautical, civil, and mechanical engineering, and in engineering science. The authors’ objective is two-fold: first, to introduce the student to the theory of structures (one- and two-dimensional) as ...

  19. Variational principle for nonlinear wave propagation in dissipative systems.

    Science.gov (United States)

    Dierckx, Hans; Verschelde, Henri

    2016-02-01

    The dynamics of many natural systems is dominated by nonlinear waves propagating through the medium. We show that in any extended system that supports nonlinear wave fronts with positive surface tension, the asymptotic wave-front dynamics can be formulated as a gradient system, even when the underlying evolution equations for the field variables cannot be written as a gradient system. The variational potential is simply given by a linear combination of the occupied volume and surface area of the wave front and changes monotonically over time.

  20. Variational methods for crystalline microstructure analysis and computation

    CERN Document Server

    Dolzmann, Georg

    2003-01-01

    Phase transformations in solids typically lead to surprising mechanical behaviour with far reaching technological applications. The mathematical modeling of these transformations in the late 80s initiated a new field of research in applied mathematics, often referred to as mathematical materials science, with deep connections to the calculus of variations and the theory of partial differential equations. This volume gives a brief introduction to the essential physical background, in particular for shape memory alloys and a special class of polymers (nematic elastomers). Then the underlying mathematical concepts are presented with a strong emphasis on the importance of quasiconvex hulls of sets for experiments, analytical approaches, and numerical simulations.

  1. Constrained variational calculus: the second variation (part I)

    CERN Document Server

    Massa, Enrico; Pagani, Enrico; Luria, Gianvittorio

    2010-01-01

    This paper is a direct continuation of arXiv:0705.2362 . The Hamiltonian aspects of the theory are further developed. Within the framework provided by the first paper, the problem of minimality for constrained calculus of variations is analyzed among the class of differentiable curves. A necessary and sufficient condition for minimality is proved.

  2. Variations in estrogen receptor ? gene and risk of dementia, and brain volumes on MRI.

    NARCIS (Netherlands)

    S.C.E. Schuit (Stephanie); A. Hofman (Albert); P.J. Koudstaal (Peter Jan); C.M. van Duijn (Cock); A.G. Uitterlinden (André); H.A.P. Pols (Huib); M.M.B. Breteler (Monique); J.B.J. van Meurs (Joyce); T. den Heijer (Tom)

    2004-01-01

    textabstractThe role of estrogens in Alzheimer's disease (AD) is controversial. We investigated the association between well-recognized, and potentially functional, polymorphisms in the estrogen receptor (ER) gene and the risk of AD in a prospective study of 6056 Caucasian older men and women aged

  3. The Compositional Variation of Microindentation Induced Densified and Plastic Deformation Volumes in Simple Silicate Glasses

    DEFF Research Database (Denmark)

    Hermansen, Christian; Matsuoka, Jun; Yoshida, Satoshi

    2012-01-01

    The densification and plastic deformation occurring in glass subjected to microindentation are established as two independent deformation mechanisms, and thought to be intimately linked to the concept of hardness and crack nucleation (quantified by the load at which radial cracks nucleate at half...

  4. Pure variation and organic stratification.

    Science.gov (United States)

    Rosanvallon, Jérôme

    2012-09-01

    The fundamental problem posed by Darwin distinguishes his theory from any transformism of the past as well as any evolutionism to come: since variation is inherent to the living, it is a question of explaining, not at all why the living varies, but instead why the living does not vary in all directions to the point of constituting a continuum of forms varying ad infinitum. What limits and stabilizes this intrinsically unlimited variation, allowing certain forms to subsist and multiply to the detriment of others, is natural selection. This double principle of intrinsic variation/extrinsic selection constitutes a vector for the unification of reality that underlies Jean-Jacques Kupiec's ontophylogenesis as well as Deleuze and Guattari's global philosophy of Nature. Therefore, everything would potentially tend to incessantly vary. The work of Kupiec and others identifies an intrinsic random variation within ontogenesis itself. For Deleuze and Guattari, it is nothing but the figure, already selected by the organic stratum, of a more fundamental or pure variation. But, in fact, nothing really varies incessantly: everything undergoes a selective pressure according to which nothing subsists as such except what manages to endure through invariance (physical stratum) or reproduction (organic stratum). Thus, organic stratification only retains from variation what ensures and augments this reproduction. In this sense, every organism stratifies, i.e. submits to its imperative of subsistence and reproduction, a body without organs that varies in itself and always tends to escape the organism, for better (intensifications of life) or worse (cancerous pathologies). Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Stochastic modeling of interannual variation of hydrologic variables

    Science.gov (United States)

    Dralle, David; Karst, Nathaniel; Müller, Marc; Vico, Giulia; Thompson, Sally E.

    2017-07-01

    Quantifying the interannual variability of hydrologic variables (such as annual flow volumes, and solute or sediment loads) is a central challenge in hydrologic modeling. Annual or seasonal hydrologic variables are themselves the integral of instantaneous variations and can be well approximated as an aggregate sum of the daily variable. Process-based, probabilistic techniques are available to describe the stochastic structure of daily flow, yet estimating interannual variations in the corresponding aggregated variable requires consideration of the autocorrelation structure of the flow time series. Here we present a method based on a probabilistic streamflow description to obtain the interannual variability of flow-derived variables. The results provide insight into the mechanistic genesis of interannual variability of hydrologic processes. Such clarification can assist in the characterization of ecosystem risk and uncertainty in water resources management. We demonstrate two applications, one quantifying seasonal flow variability and the other quantifying net suspended sediment export.

  6. Time-wise variation of scouring at bridge abutments

    Indian Academy of Sciences (India)

    A Melih Yanmaz; Omer Kose

    2007-06-01

    Accurate estimation of the maximum possible depth of scour at bridge abutments is important in decision-making for the safe depth of burial of footings. Besides, investigation of the geometric features of scour holes around abutments provides useful information for the degree of scour counter-measure to be implemented against excessive scouring. Experiments have been performed to investigate time-dependent characteristics of scour holes around vertical wall abutments under clear water conditions with uniform bed materials. Temporal variations of scour depth and scour contours were measured. Using this information, an empirical relation was developed for temporal variation of scour depth. Additional relations were also derived for time-dependent volume and surface area of the scour holes around abutments. The findings of this study may provide useful informatoin for preliminary design of abutment footings and placement details of armoring counter-measures, such as riprap.

  7. Pristine extraterrestrial material with unprecedented nitrogen isotopic variation.

    Science.gov (United States)

    Briani, Giacomo; Gounelle, Matthieu; Marrocchi, Yves; Mostefaoui, Smail; Leroux, Hugues; Quirico, Eric; Meibom, Anders

    2009-06-30

    Pristine meteoritic materials carry light element isotopic fractionations that constrain physiochemical conditions during solar system formation. Here we report the discovery of a unique xenolith in the metal-rich chondrite Isheyevo. Its fine-grained, highly pristine mineralogy has similarity with interplanetary dust particles (IDPs), but the volume of the xenolith is more than 30,000 times that of a typical IDP. Furthermore, an extreme continuum of N isotopic variation is present in this xenolith: from very light N isotopic composition (delta(15)N(AIR) = -310 +/- 20 per thousand), similar to that inferred for the solar nebula, to the heaviest ratios measured in any solar system material (delta(15)N(AIR) = 4,900 +/- 300 per thousand). At the same time, its hydrogen and carbon isotopic compositions exhibit very little variation. This object poses serious challenges for existing models for the origin of light element isotopic anomalies.

  8. Storm surge variational assimilation model

    Directory of Open Access Journals (Sweden)

    Shi-li HUANG

    2010-06-01

    Full Text Available To eliminate errors caused by uncertainty of parameters and further improve capability of storm surge forecasting, the variational data assimilation method is applied to the storm surge model based on unstructured grid with high spatial resolution. The method can effectively improve the forecasting accuracy of storm surge induced by typhoon through controlling wind drag force coefficient parameter. The model is first theoretically validated with synthetic data. Then, the real storm surge process induced by the TC 0515 typhoon is forecasted by the variational data assimilation model, and results show the feasibility of practical application.

  9. A compiler for variational forms

    CERN Document Server

    Kirby, Robert C; 10.1145/1163641.1163644

    2011-01-01

    As a key step towards a complete automation of the finite element method, we present a new algorithm for automatic and efficient evaluation of multilinear variational forms. The algorithm has been implemented in the form of a compiler, the FEniCS Form Compiler FFC. We present benchmark results for a series of standard variational forms, including the incompressible Navier-Stokes equations and linear elasticity. The speedup compared to the standard quadrature-based approach is impressive; in some cases the speedup is as large as a factor 1000.

  10. Homotopy Method for Variational Inequalities

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@Solving a finite-dimensional variational inequality is to find a vector x* ∈ X Rn such that where X is a nonempty, closed and convex subset of Rn and F is a mapping from Rn to itself,denoted by VI(X, F). The variational inequality problem (VIP) has had many successful practical applications in the last three decades. It has been used to formulate and investigate equilibrium models arising in economics, transportation, regional science and operations research. So far, a large number of existence conditions have been developed in the literature. Harker and Pang[1] gave excellent surveys of theories, methods and applications of VIPs.

  11. International Linear Collider Technical Design Report (Volumes 1 through 4)

    Energy Technology Data Exchange (ETDEWEB)

    Harrison M.

    2013-03-27

    The design report consists of four volumes: Volume 1, Executive Summary; Volume 2, Physics; Volume 3, Accelerator (Part I, R and D in the Technical Design Phase, and Part II, Baseline Design); and Volume 4, Detectors.

  12. Urban Run-off Volumes Dependency on Rainfall Measurement Method

    DEFF Research Database (Denmark)

    Pedersen, L.; Jensen, N. E.; Rasmussen, Michael R.;

    2005-01-01

    Urban run-off is characterized with fast response since the large surface run-off in the catchments responds immediately to variations in the rainfall. Modeling such type of catchments is most often done with the input from very few rain gauges, but the large variation in rainfall over small area...... resolutions and single gauge rainfall was fed to a MOUSE run-off model. The flow and total volume over the event is evaluated.......Urban run-off is characterized with fast response since the large surface run-off in the catchments responds immediately to variations in the rainfall. Modeling such type of catchments is most often done with the input from very few rain gauges, but the large variation in rainfall over small areas...... suggests that rainfall needs to be measured with a much higher spatial resolution (Jensen and Pedersen, 2004). This paper evaluates the impact of using high-resolution rainfall information from weather radar compared to the conventional single gauge approach. The radar rainfall in three different...

  13. Strategies to evaluate the impact of rectal volume on prostate motion during three-dimensional conformal radiotherapy for prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Poli, Ana Paula Diniz Fortuna, E-mail: anapaulafortuna@yahoo.com.br [Universidade Estadual de Campinas (CAISM/UNICAMP), Campinas, SP (Brazil). Centro de Atencao Integrada a Saude da Mulher. Divisao de Radioterapia; Dias, Rodrigo Souza; Giordani, Adelmo Jose; Segreto, Helena Regina Comodo; Segreto, Roberto Araujo [Universidade Federal de Sao Paulo (EPM/UNIFESP), Sao Paulo, SP (Brazil). Escola Paulista de Medicina. Divisao de Radioterapia

    2016-01-15

    Objective: To evaluate the rectal volume influence on prostate motion during three-dimensional conformal radiotherapy (3D-CRT) for prostate cancer. Materials and Methods: Fifty-one patients with prostate cancer underwent a series of three computed tomography scans including an initial planning scan and two subsequent scans during 3D-CRT. The organs of interest were outlined. The prostate contour was compared with the initial CT images considering the anterior, posterior, superior, inferior and lateral edges of the organ. Variations in the anterior limits and volume of the rectum were assessed and correlated with prostate motion in the anteroposterior direction. Results: The maximum range of prostate motion was observed in the superoinferior direction, followed by the anteroposterior direction. A significant correlation was observed between prostate motion and rectal volume variation (p = 0.037). A baseline rectal volume superior to 70 cm{sup 3} had a significant influence on the prostate motion in the anteroposterior direction (p = 0.045). Conclusion: The present study showed a significant interfraction motion of the prostate during 3D-CRT with greatest variations in the superoinferior and anteroposterior directions, and that a large rectal volume influences the prostate motion with a cutoff value of 70 cm{sup 3}. Therefore, the treatment of patients with a rectal volume > 70 cm{sup 3} should be re-planned with appropriate rectal preparation. Keywords: Rectal volume; Prostate cancer; Three-dimensional conformal radiotherapy. (author)

  14. NJP VOLUME 41 NO 2

    African Journals Online (AJOL)

    PROF. EZECHUKWU

    2014-01-08

    Jan 8, 2014 ... ous infections, malignant neoplasms and autoimmune vasculitis are common ... age and may have a geographical variation. This pro- ... constraints, only one child with sickle cell stroke was ... Cranial nerves VI and VII were largely associated with ... influenza and hepatitis B virus (HBV) vaccines.6 Proba-.

  15. Socialization of prosocial behavior: Gender differences in the mediating role of child brain volume.

    Science.gov (United States)

    Kok, Rianne; Prinzie, Peter; Bakermans-Kranenburg, Marian J; Verhulst, Frank C; White, Tonya; Tiemeier, Henning; van IJzendoorn, Marinus H

    2017-06-18

    Evidence has been accumulating for the impact of normal variation in caregiving quality on brain morphology in children, but the question remains whether differences in brain volume related to early caregiving translate to behavioral implications. In this longitudinal population-based study (N = 162), moderated mediation was tested for the relation between parental sensitivity and child prosocial behavior via brain volume, in boys and girls. Both maternal and paternal sensitivity were repeatedly observed between 1 and 4 years of age. Brain volume was assessed using magnetic resonance imaging measurements at age 8, and self-reported prosocial behavior of children was assessed at 9 years of age. Parental sensitivity was positively related to child brain volume, and to child prosocial behavior at trend level. Child brain volume was negatively related to child prosocial behavior. A significant gender-by-brain interaction was found, illustrating that daughters of sensitive parents were more prosocial and that less prosocial behavior was reported for girls with a larger total brain volume. Child gender significantly moderated the indirect effect of parental sensitivity on prosocial behavior via total brain volume. A significant indirect pathway was found only in girls. The results warrant replication but indicate the importance of considering gender when studying the behavioral implications of differences in brain volume related to early caregiving experiences.

  16. Waste minimization handbook, Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Boing, L.E.; Coffey, M.J.

    1995-12-01

    This technical guide presents various methods used by industry to minimize low-level radioactive waste (LLW) generated during decommissioning and decontamination (D and D) activities. Such activities generate significant amounts of LLW during their operations. Waste minimization refers to any measure, procedure, or technique that reduces the amount of waste generated during a specific operation or project. Preventive waste minimization techniques implemented when a project is initiated can significantly reduce waste. Techniques implemented during decontamination activities reduce the cost of decommissioning. The application of waste minimization techniques is not limited to D and D activities; it is also useful during any phase of a facility`s life cycle. This compendium will be supplemented with a second volume of abstracts of hundreds of papers related to minimizing low-level nuclear waste. This second volume is expected to be released in late 1996.

  17. Variation in opioid prescribing patterns between ED providers.

    Science.gov (United States)

    Smulowitz, Peter B; Cary, Chris; Boyle, Katherine L; Novack, Victor; Jagminas, Liudvikas

    2016-12-01

    Abuse of opioid prescription drugs has become an epidemic across the developed world. Despite the fact that emergency physicians overall account for a small proportion of total opioids prescribed, the number of prescriptions has risen dramatically in the past decade and, to some degree, contributes to the available supply of opioids in the community, some of which are diverted for non-medical use. Since successfully reducing opioid prescribing on the individual level first requires knowledge of current prescribing patterns, we sought to determine to what extent variation exists in opioid prescribing patterns at our institution. This was a single-institution observational study at a community hospital with an annual ED volume of 47,000 visits. We determined the number of prescriptions written by each provider, both total number and accounting for the number of patients seen. Our primary outcome measure was the level of variation at the physician level for number of prescriptions written per patient. We also identified the mean number of pills written per prescription. We analyzed data from November 13, 2014 through July 31, 2015 for 21 full-time providers. There were a total of 2211 prescriptions for opioids written over this time period for a total of 17,382 patients seen. On a per-patient basis, the rate of opioid prescriptions written per patient during this period was 127 per 1000 visits (95 % CI 122-132). There was a variation on the individual provider level, with rates ranging from 33 per to 332 per 1000 visits. There was also substantial variation by provider in the number of pills written per prescription with coefficient of variation (standard deviation divided by mean) averaged over different opioids ranging from 16 to 40 %. There was significant variation in opioid prescribing patterns at the individual physician level, even when accounting for the number of patients seen.

  18. Quantitative radiology: automated measurement of polyp volume in computed tomography colonography using Hessian matrix-based shape extraction and volume growing

    Science.gov (United States)

    Epstein, Mark L.; Obara, Piotr R.; Chen, Yisong; Liu, Junchi; Zarshenas, Amin; Makkinejad, Nazanin; Dachman, Abraham H.

    2015-01-01

    Background Current measurement of the single longest dimension of a polyp is subjective and has variations among radiologists. Our purpose was to develop a computerized measurement of polyp volume in computed tomography colonography (CTC). Methods We developed a 3D automated scheme for measuring polyp volume at CTC. Our scheme consisted of segmentation of colon wall to confine polyp segmentation to the colon wall, extraction of a highly polyp-like seed region based on the Hessian matrix, a 3D volume growing technique under the minimum surface expansion criterion for segmentation of polyps, and sub-voxel refinement and surface smoothing for obtaining a smooth polyp surface. Our database consisted of 30 polyp views (15 polyps) in CTC scans from 13 patients. Each patient was scanned in the supine and prone positions. Polyp sizes measured in optical colonoscopy (OC) ranged from 6-18 mm with a mean of 10 mm. A radiologist outlined polyps in each slice and calculated volumes by summation of volumes in each slice. The measurement study was repeated 3 times at least 1 week apart for minimizing a memory effect bias. We used the mean volume of the three studies as “gold standard”. Results Our measurement scheme yielded a mean polyp volume of 0.38 cc (range, 0.15-1.24 cc), whereas a mean “gold standard” manual volume was 0.40 cc (range, 0.15-1.08 cc). The “gold-standard” manual and computer volumetric reached excellent agreement (intra-class correlation coefficient =0.80), with no statistically significant difference [P (F≤f) =0.42]. Conclusions We developed an automated scheme for measuring polyp volume at CTC based on Hessian matrix-based shape extraction and volume growing. Polyp volumes obtained by our automated scheme agreed excellently with “gold standard” manual volumes. Our fully automated scheme can efficiently provide accurate polyp volumes for radiologists; thus, it would help radiologists improve the accuracy and efficiency of polyp volume

  19. Prices Up and Volumes Stable

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    2011 First Half China Garment Industry Report Exports Grew at a Slower Pace China Customs reported the garment & accessories export value of $51.286 billion for the first five months of this year, up 23.12% y/y, accounting for 56.28 percent of the total, 5% lower than the previous year’s points.Despite sales prices increase, sales volume remain stable. From Jan. to May

  20. Volume 7, Issue 1 2016

    OpenAIRE

    Tracy Creagh; John Clarke; Karen Nelson

    2016-01-01

    Welcome to Volume 7 of Student Success.  This editorial has two parts: The first part maintains the “doing things differently” tradition, making readers aware by chronicling the publishing of the journal in an open access (OA) forum.  Future editorials will briefly discuss other aspects and issues pertaining to the new scholarly publishing landscape that this journal adheres to, such as:  Creative Commons Licencing; ORCID IDs; considerations of new peer review models and importantly; measurin...

  1. Analytic torsion and symplectic volume

    DEFF Research Database (Denmark)

    McLellan, Brendan Donald Kenneth

    2013-01-01

    This article studies the abelian analytic torsion on a closed, oriented, quasi-regular Sasakian three-manifold and identifies this quantity as a specific multiple of the natural unit symplectic volume form on the moduli space of flat abelian connections. This identification effectively computes...... the analytic torsion explicitly in terms of Seifert data for a given quasi-regular Sasakian structure on a three-manifold....

  2. Memorial volume for Y. Nambu

    CERN Document Server

    Chang, Lay Nam; Han, Moo-Young; Phua, Kok Khoo

    2016-01-01

    We have lost one of the giants of the twentieth century physics when Yoichiro Nambu passed away in July, 2015, at the age of 94. Today's Standard Model, though still incomplete in many respects, is the culmination of the most successful theory of the Universe to date, and it is built upon foundations provided by discoveries made by Nambu in the 1960s: the mechanism of spontaneously broken symmetry in Nature (with G Jona-Lasinio) and the hidden new SU(3) symmetry of quarks and gluons (with M-Y Han). In this volume honoring Nambu's memory, World Scientific Publishing presents a unique collection of papers written by his former colleagues, collaborating researchers and former students and associates, not only citing Nambu's great contributions in physics but also many personal and private reminiscences, some never told before. This volume also contains the very last scientific writing by Professor Nambu himself, discussing the development of particle physics. This book is a volume for all who benefited not on...

  3. Genetic variation in the zebrafish

    NARCIS (Netherlands)

    Guryev, V.; Koudijs, M.J.; Berezikov, E.; Johnson, S.L.; Plasterk, R.; van Eeden, F.; Cuppen, E.

    2006-01-01

    Although zebrafish was introduced as a laboratory model organism several decades ago and now serves as a primary model for developmental biology, there is only limited data on its genetic variation. An establishment of a dense polymorphism map becomes a requirement for effective linkage analysis and

  4. Creativity, depression, and circannual variation.

    Science.gov (United States)

    Sitton, S C; Hughes, R B

    1995-12-01

    Verbal creativity has been linked to personal and family histories of bipolar depression. The present studies investigated the relationship between creativity and atypical symptoms of bipolar depression such as seasonal mood variations. Although more creative individuals, as measured by scores on the Remote Associates Test and a writing sample, perceived seasonal fluctuations in their creativity, no significant differences in performance were found.

  5. Genetisk variation og langt liv

    DEFF Research Database (Denmark)

    Sørensen, Mette

    2013-01-01

    andre ikke gør. I dette ph.d.-projekt undersøgte vi sammenhængen mellem levetid og variation i tre biologiske skadesprocesser. De tre er: antioxidanter, væksthormon/insulin-signalering og DNA-reparation. Vi fandt nye genvariationer, hvoraf nogle har positiv indflydelse på chancen for at blive meget...

  6. Sea level and climate variations

    NARCIS (Netherlands)

    Oerlemans, J.

    1985-01-01

    Review paper, ESA Symposium on Application of Satellite Data to Climate Modelling. Alpbach (Austria) Sea level is an essential component of the climate system, on which many human activities in the coastal zone depend. Climate variations leading to changes in relative sea level are

  7. The Dimensionality of Grammatical Variation

    Science.gov (United States)

    Sankoff, David; Cedergren, Henrietta J.

    1976-01-01

    Computer-based multidimensional scaling techniques are used to determine the dimensionality of grammatical variation in three large sets of data: Ross' (1973) Noun Phrase and fake Noun Phrase data; Sankoff's (1974) complementizer "que"-deletion (Montreal French) data; and Cedergren's (1973) syllable-final S-reduction (Panamanian Spanish) data. (DB)

  8. Symmetries and variation of spectra

    OpenAIRE

    Bhatia, Rajendra; Elsner, Ludwig

    1992-01-01

    An interesting class of matrices is shown to have the property that the spectrum of each of its elements is invariant under multiplication by p-th roots of unity. For this class and tor a class of Hamiltonian matrices improved spectral variation bounds are obtained.

  9. Quadratic Variation by Markov Chains

    DEFF Research Database (Denmark)

    Hansen, Peter Reinhard; Horel, Guillaume

    We introduce a novel estimator of the quadratic variation that is based on the the- ory of Markov chains. The estimator is motivated by some general results concerning filtering contaminated semimartingales. Specifically, we show that filtering can in prin- ciple remove the effects of market...

  10. Orbital variations, climate and paleoecology.

    Science.gov (United States)

    Bartlein, P J; Prentice, I C

    1989-07-01

    One of the most exciting discoveries in the earth sciences in recent decades has been the proof that ice ages are governed by deterministic variations in the earth's orbit. These variations modify the latitudinal and seasonal distribution of solar radiation at periods ranging from 103 to 10(5) years, and alternately produce conditions for building and melting continental ice. The same solar radiation variations also govern other aspects of world climate, including the temperatures of the midlatitude continental interiors, the intensity of upwelling in the tropical oceans, and the strength and extent of the monsoons. The interplay of solar radiation, seasonality and ice-sheet changes is responsible for the complex ecological history documented in the fossil record of the past 20 000 years. But the orbital variations have occurred throughout earth's history, and have caused periodic environmental changes in both terrestrial and marine environments even during times when there was no ice. Species have responded to these changes by range migration, an evolved ability that may maintain their genetic coherence in the face of a continually changing environment.

  11. Variational integrators in plasma physics

    Energy Technology Data Exchange (ETDEWEB)

    Kraus, Michael

    2013-07-01

    To a large extent, research in plasma physics is concerned with the description and analysis of energy and momentum transfer between different scales and different kinds of waves. In the numerical modelling of such phenomena it appears to be crucial to describe the transfer processes preserving the underlying conservation laws in order to prevent physically spurious solutions. In this work, special numerical methods, so called variational integrators, are developed for several models of plasma physics. Special attention is given to conservation properties like conservation of energy and momentum. By design, variational integrators are applicable to all systems that have a Lagrangian formulation. Usually, equations of motion are derived by Hamilton's action principle and then discretised. In the application of the variational integrator theory, the order of these steps is reversed. At first, the Lagrangian and the accompanying variational principle are discretised, such that discrete equations of motion can be obtained directly by applying the discrete variational principle to the discrete Lagrangian. The advantage of this approach is that the resulting discretisation automatically retains the conservation properties of the continuous system. Following an overview of the geometric formulation of classical mechanics and field theory, which forms the basis of the variational integrator theory, variational integrators are introduced in a framework adapted to problems from plasma physics. The applicability of variational integrators is explored for several important models of plasma physics: particle dynamics (guiding centre dynamics), kinetic theory (the Vlasov-Poisson system) and fluid theory (magnetohydrodynamics). These systems, with the exception of guiding centre dynamics, do not possess a Lagrangian formulation to which the variational integrator methodology is directly applicable. Therefore the theory is extended by linking it to Ibragimov's theory of

  12. Geometric constrained variational calculus. III: The second variation (Part II)

    Science.gov (United States)

    Massa, Enrico; Luria, Gianvittorio; Pagani, Enrico

    2016-03-01

    The problem of minimality for constrained variational calculus is analyzed within the class of piecewise differentiable extremaloids. A fully covariant representation of the second variation of the action functional based on a family of local gauge transformations of the original Lagrangian is proposed. The necessity of pursuing a local adaptation process, rather than the global one described in [1] is seen to depend on the value of certain scalar attributes of the extremaloid, here called the corners’ strengths. On this basis, both the necessary and the sufficient conditions for minimality are worked out. In the discussion, a crucial role is played by an analysis of the prolongability of the Jacobi fields across the corners. Eventually, in the appendix, an alternative approach to the concept of strength of a corner, more closely related to Pontryagin’s maximum principle, is presented.

  13. Site Environmental Report for 2005 Volume I and Volume II

    Energy Technology Data Exchange (ETDEWEB)

    Ruggieri, Michael

    2006-07-07

    Each year, Ernest Orlando Lawrence Berkeley National Laboratory prepares an integrated report on its environmental programs to satisfy the requirements of United States Department of Energy Order 231.1A, ''Environment, Safety, and Health Reporting''. The ''Site Environmental Report for 2005'' summarizes Berkeley Lab's environmental management performance, presents environmental monitoring results, and describes significant programs for calendar year 2005. (Throughout this report, Ernest Orlando Lawrence Berkeley National Laboratory is referred to as ''Berkeley Lab'', ''the Laboratory'', ''Lawrence Berkeley National Laboratory'', and ''LBNL''.) The report is separated into two volumes. Volume I contains an overview of the Laboratory, the status of environmental programs, and summarized results from surveillance and monitoring activities. This year's Volume I text body is organized into an executive summary followed by six chapters. The report's structure has been reorganized this year, and it now includes a chapter devoted to environmental management system topics. Volume II contains individual data results from surveillance and monitoring activities. The ''Site Environmental Report'' is distributed by releasing it on the Web from the Berkeley Lab Environmental Services Group (ESG) home page, which is located at http://www.lbl.gov/ehs/esg/. Many of the documents cited in this report also are accessible from the ESG Web page. CD and printed copies of this Site Environmental Report are available upon request. The report follows the Laboratory's policy of using the International System of Units (SI), also known as the metric system of measurements. Whenever possible, results are also reported using the more conventional (non-SI) system of measurements, because the non-SI system is referenced by several current

  14. General inverse problems for regular variation

    DEFF Research Database (Denmark)

    Damek, Ewa; Mikosch, Thomas Valentin; Rosinski, Jan

    2014-01-01

    Regular variation of distributional tails is known to be preserved by various linear transformations of some random structures. An inverse problem for regular variation aims at understanding whether the regular variation of a transformed random object is caused by regular variation of components ...

  15. On the volume of cremated remains

    DEFF Research Database (Denmark)

    Harvig, Lise Lock; Lynnerup, Niels

    2013-01-01

    Harvig, L., Lynnerup, N. 2013. On the effective volume of prehistoric cremains - a comparative study of cremated bone volume measured manually and assessed by Computed Tomography. Journal of Archaeological Science 40, p. 2713–2722.......Harvig, L., Lynnerup, N. 2013. On the effective volume of prehistoric cremains - a comparative study of cremated bone volume measured manually and assessed by Computed Tomography. Journal of Archaeological Science 40, p. 2713–2722....

  16. The parallel volume at large distances

    DEFF Research Database (Denmark)

    Kampf, Jürgen

    In this paper we examine the asymptotic behavior of the parallel volume of planar non-convex bodies as the distance tends to infinity. We show that the difference between the parallel volume of the convex hull of a body and the parallel volume of the body itself tends to . This yields a new proof...... for the fact that a planar body can only have polynomial parallel volume, if it is convex. Extensions to Minkowski spaces and random sets are also discussed....

  17. The parallel volume at large distances

    DEFF Research Database (Denmark)

    Kampf, Jürgen

    In this paper we examine the asymptotic behavior of the parallel volume of planar non-convex bodies as the distance tends to infinity. We show that the difference between the parallel volume of the convex hull of a body and the parallel volume of the body itself tends to 0. This yields a new proof...... for the fact that a planar body can only have polynomial parallel volume, if it is convex. Extensions to Minkowski spaces and random sets are also discussed....

  18. INFLUENCE OF FIBRE VOLUME REINFORCEMENT IN DRILLING GFRP LAMINATES

    Directory of Open Access Journals (Sweden)

    D. ABDUL BUDAN

    2011-12-01

    Full Text Available This paper presents an investigation on the influence of fiber volume reinforcement on various aspects of machining. Drilling experiments were conducted to study the tool wear, surface finish, delamination factor and hole quality on GFRP composites. The work reports the variation of tool wear, surface roughness, hole quality, chip characteristics, delamination factor with the variation of fibre volume reinforcement. Results revealed that the increase in fiber percentage increased the tool wear, delamination factor, surface roughness value and decreased hole quality. Minimum surface roughness, tool wear and better hole quality was obtained for 30% fibre content composites. 70% Fibre content composites produced hazardous surface roughness. Pull out of fibres and fibril formation are significant in decreasing the hole quality and increased surface roughness. Increased tool – fibre interaction and thermal softening of the tool causes increased tool wear. In higher fibre content composites, extensive plasticity was absent consequently brittle ceramic fibres were fractured easily. Hence small segment type chips were obtained. The fibre pull out and fibrils present near the hole exit forms the remainder of the laminate causes increased damage zone near the hole exit. Hence high delamination factor was obtained.

  19. Bifilar analysis study, volume 1

    Science.gov (United States)

    Miao, W.; Mouzakis, T.

    1980-01-01

    A coupled rotor/bifilar/airframe analysis was developed and utilized to study the dynamic characteristics of the centrifugally tuned, rotor-hub-mounted, bifilar vibration absorber. The analysis contains the major components that impact the bifilar absorber performance, namely, an elastic rotor with hover aerodynamics, a flexible fuselage, and nonlinear individual degrees of freedom for each bifilar mass. Airspeed, rotor speed, bifilar mass and tuning variations are considered. The performance of the bifilar absorber is shown to be a function of its basic parameters: dynamic mass, damping and tuning, as well as the impedance of the rotor hub. The effect of the dissimilar responses of the individual bifilar masses which are caused by tolerance induced mass, damping and tuning variations is also examined.

  20. Centrifugal Step Emulsification can Produce Water in Oil Emulsions with Extremely High Internal Volume Fractions

    Directory of Open Access Journals (Sweden)

    Friedrich Schuler

    2015-08-01

    Full Text Available The high throughput preparation of emulsions with high internal volume fractions is important for many different applications, e.g., drug delivery. However, most emulsification techniques reach only low internal volume fractions and need stable flow rates that are often difficult to control. Here, we present a centrifugal high throughput step emulsification disk for the fast and easy production of emulsions with high internal volume fractions above 95%. The disk produces droplets at generation rates of up to 3700 droplets/s and, for the first time, enables the generation of emulsions with internal volume fractions of >97%. The coefficient of variation between droplet sizes is very good (4%. We apply our system to show the in situ generation of gel emulsion. In the future, the recently introduced unit operation of centrifugal step emulsification may be used for the high throughput production of droplets as reaction compartments for clinical diagnostics or as starting material for micromaterial synthesis.

  1. Different approaches to synovial membrane volume determination by magnetic resonance imaging: manual versus automated segmentation

    DEFF Research Database (Denmark)

    Østergaard, Mikkel

    1997-01-01

    Automated fast (5-20 min) synovial membrane volume determination by MRI, based on pre-set post-gadolinium-DTPA enhancement thresholds, was evaluated as a substitute for a time-consuming (45-120 min), previously validated, manual segmentation method. Twenty-nine knees [rheumatoid arthritis (RA) 13...... or synovial membrane volume, e.g. no systematic errors were found. The inter-MRI variation, evaluated in three knees and three wrists, was higher than by manual segmentation, particularly due to sensitivity to malalignment artefacts. Examination of test objects proved the high accuracy of the general...... methodology for volume determinations (maximal error 6.3%). Preceded by the determination of reproducibility and the optimal threshold at the available MR unit, automated 'threshold' segmentation appears to be acceptable when changes rather than absolute values of synovial membrane volumes are most important...

  2. Ion Channels Involved in Cell Volume Regulation

    DEFF Research Database (Denmark)

    Hoffmann, Else Kay

    2011-01-01

    This mini review outlines studies of cell volume regulation in two closely related mammalian cell lines: nonadherent Ehrlich ascites tumour cells (EATC) and adherent Ehrlich Lettre ascites (ELA) cells. Focus is on the regulatory volume decrease (RVD) that occurs after cell swelling, the volume...

  3. Comparing Volumes of Prisms and Pyramids

    Science.gov (United States)

    Vinogradova, Natalya

    2012-01-01

    Students' experience in using formulas for volumes is often limited to substituting numbers into given formulas. An activity presented in this article may help students make connections between the formulas for volumes of prisms and volumes of pyramids. In addition, some interesting facts from number theory arise, demonstrating strong connections…

  4. Culture of Schools. Final Report. Volume IV.

    Science.gov (United States)

    American Anthropological Association, Washington, DC.

    The final volume of this 4-volume report contains further selections from "Anthropological Perspectives on Education," a monograph to be published by Basic Books of New York. (Other selections are in Vol. III, SP 003 902.) Monograph selections appearing in this volume are: "Great Tradition, Little Tradition, and Formal Education;""Indians,…

  5. Volume control device for digital signals

    NARCIS (Netherlands)

    Schinkel, Daniel; van Tuijl, Adrianus Johannes Maria; Nuijten, Petrus A.C.M.

    2004-01-01

    A digital volume control device comprises a logic unit for volume control of digital input signals. Successively supplied m-bits words with maximally k bits active, derived from the output signals of or supplied by a volume control (4) with a quantizer (5) element the filtered m-bits workds are

  6. Morphometrical variations of the carpal bones in thoroughbreds and ponies.

    Science.gov (United States)

    Abdunnabi, A H; Ahmed, Y A; Philip, C J; Davies, H M S

    2012-04-01

    There is scant morphological data for equine carpal bones despite the frequent pathology in Thoroughbreds (TB). This study aimed to identify morphological and morphometrical variations and similarities in carpal bones between and within TB and Ponies (Po). Carpal bones from nine TB and 13 Po were prepared by boiling and drying. Lateromedial width, dorsopalmar depth, proximodistal height, relative density and volume of each bone were measured. Normalized measurements of the radial (Cr) and third (C3) carpal bones were significantly different in all dimensions, and there were significant variations in relative sizes of articular facets of the ulnar (Cu), C3 and fourth (C4) carpal bones between the groups. Bilaterally, the proportionate volume of the intermediate carpal bone (Ci) was significantly greater in Po while that of Cu and C4 were significantly greater in TB. Relative density of most bones was greater in Po. The palmar tuberosity of the proximal surface of Ci and palmar tubercle on the palmar surface of Cu were more prominent and relatively larger in TB. In the second carpal bone (C2), the distal extent of the proximal articular surface on the palmar surface was greater in Po. The inconsistent first carpal bone (C1) was relatively larger in Po. Morphometrical similarities and differences in carpal bones between TB and Po indicate potential effects of selection for body size or fast exercise.

  7. Regulation of amniotic fluid volume.

    Science.gov (United States)

    Beall, M H; van den Wijngaard, J P H M; van Gemert, M J C; Ross, M G

    2007-01-01

    Water arrives in the mammalian gestation from the maternal circulation across the placenta. It then circulates between the fetal water compartments, including the fetal body compartments, the placenta and the amniotic fluid. Amniotic fluid is created by the flow of fluid from the fetal lung and bladder. A major pathway for amniotic fluid resorption is fetal swallowing; however, in many cases the amounts of fluid produced and absorbed do not balance. A second resorption pathway, the intramembranous pathway (across the amnion to the fetal circulation), has been proposed to explain the maintenance of normal amniotic fluid volume. Amniotic fluid volume is thus a function both of the amount of water transferred to the gestation across the placental membrane, and the flux of water across the amnion. Water flux across biologic membranes may be driven by osmotic or hydrostatic forces; existing data suggest that intramembranous flow in humans is driven by the osmotic difference between the amniotic fluid and the fetal serum. The driving force for placental flow is more controversial, and both forces may be in effect. The mechanism(s) responsible for regulating water flow to and from the amniotic fluid is unknown. In other parts of the body, notably the kidney, water flux is regulated by the expression of aquaporin water channels on the cell membrane. We hypothesize that aquaporins have a role in regulating water flux across both the amnion and the placenta, and present evidence in support of this theory. Current knowledge of gestational water flow is sufficient to allow prediction of fetal outcome when water flow is abnormal, as in twin-twin transfusion syndrome. Further insight into these mechanisms may allow novel treatments for amniotic fluid volume abnormalities with resultant improvement in clinical outcome.

  8. Bernoulli Variational Problem and Beyond

    KAUST Repository

    Lorz, Alexander

    2013-12-17

    The question of \\'cutting the tail\\' of the solution of an elliptic equation arises naturally in several contexts and leads to a singular perturbation problem under the form of a strong cut-off. We consider both the PDE with a drift and the symmetric case where a variational problem can be stated. It is known that, in both cases, the same critical scale arises for the size of the singular perturbation. More interesting is that in both cases another critical parameter (of order one) arises that decides when the limiting behaviour is non-degenerate. We study both theoretically and numerically the values of this critical parameter and, in the symmetric case, ask if the variational solution leads to the same value as for the maximal solution of the PDE. Finally we propose a weak formulation of the limiting Bernoulli problem which incorporates both Dirichlet and Neumann boundary condition. © 2013 Springer-Verlag Berlin Heidelberg.

  9. Variational principles for dissipative waves

    Science.gov (United States)

    Dodin, I. Y.; Ruiz, D. E.

    2016-10-01

    Variational methods are a powerful tool in plasma theory. However, their applications are typically restricted to conservative systems or require doubling of variables, which often contradicts the purpose of the variational approach altogether. We show that these restrictions can be relaxed for some classes of dynamical systems that are of practical interest in plasma physics, particularly including dissipative plasma waves. Applications will be discussed to calculating dispersion relations and modulational dynamics of individual plasma waves and wave ensembles. The work was supported by the NNSA SSAA Program through DOE Research Grant No. DE-NA0002948, by the U.S. DOE through Contract No. DE-AC02-09CH11466, and by the U.S. DOD NDSEG Fellowship through Contract No. 32-CFR-168a.

  10. Decadal variations in groundwater quality

    DEFF Research Database (Denmark)

    Jessen, Søren; Postma, Dieke; Thorling, Lærke

    2017-01-01

    Twenty-five years of groundwater quality monitoring in a sandy aquifer beneath agricultural fields showed large temporal and spatial variations in major ion groundwater chemistry, which were linked closely to the nitrate (NO3) content of agricultural recharge. Between 1988 and 2013, the NO3 content...... loading. Agriculture thus is an important determinant of major ion groundwater chemistry. Temporal and spatial variations in the groundwater quality were simulated using a 2D reactive transport model, which combined effects of the historical NO3 leaching and denitrification, with dispersive mixing...... into the pristine groundwater residing deeper in the aquifer. Reactant-to-product ratios across reaction fronts are altered by dispersive mixing and transience in reactant input functions. Modelling therefore allowed a direct comparison of observed and simulated ratios of concentrations of NO3 (reactant...

  11. Clinical Interpretation of Genomic Variations.

    Science.gov (United States)

    Sayitoğlu, Müge

    2016-09-05

    Novel high-throughput sequencing technologies generate large-scale genomic data and are used extensively for disease mapping of monogenic and/or complex disorders, personalized treatment, and pharmacogenomics. Next-generation sequencing is rapidly becoming routine tool for diagnosis and molecular monitoring of patients to evaluate therapeutic efficiency. The next-generation sequencing platforms generate huge amounts of genetic variation data and it remains a challenge to interpret the variations that are identified. Such data interpretation needs close collaboration among bioinformaticians, clinicians, and geneticists. There are several problems that must be addressed, such as the generation of new algorithms for mapping and annotation, harmonization of the terminology, correct use of nomenclature, reference genomes for different populations, rare disease variant databases, and clinical reports.

  12. Variational Principle for Planetary Interiors

    Science.gov (United States)

    Zeng, Li; Jacobsen, Stein B.

    2016-09-01

    In the past few years, the number of confirmed planets has grown above 2000. It is clear that they represent a diversity of structures not seen in our own solar system. In addition to very detailed interior modeling, it is valuable to have a simple analytical framework for describing planetary structures. The variational principle is a fundamental principle in physics, entailing that a physical system follows the trajectory, which minimizes its action. It is alternative to the differential equation formulation of a physical system. Applying the variational principle to the planetary interior can beautifully summarize the set of differential equations into one, which provides us some insight into the problem. From this principle, a universal mass-radius relation, an estimate of the error propagation from the equation of state to the mass-radius relation, and a form of the virial theorem applicable to planetary interiors are derived.

  13. Variational Integrators for Reduced Magnetohydrodynamics

    CERN Document Server

    Kraus, Michael; Grasso, Daniela

    2015-01-01

    Reduced magnetohydrodynamics is a simplified set of magnetohydrodynamics equations with applications to both fusion and astrophysical plasmas, possessing a noncanonical Hamiltonian structure and consequently a number of conserved functionals. We propose a new discretisation strategy for these equations based on a discrete variational principle applied to a formal Lagrangian. The resulting integrator preserves important quantities like the total energy, magnetic helicity and cross helicity exactly (up to machine precision). As the integrator is free of numerical resistivity, spurious reconnection along current sheets is absent in the ideal case. If effects of electron inertia are added, reconnection of magnetic field lines is allowed, although the resulting model still possesses a noncanonical Hamiltonian structure. After reviewing the conservation laws of the model equations, the adopted variational principle with the related conservation laws are described both at the continuous and discrete level. We verify...

  14. Environmental Report 1995. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Harrach, R.J.; Failor, R.A.; Gallegos, G.M. [and others

    1996-09-01

    This report contains the results of Lawrence Livermore National Laboratory`s (LLNL) environmental monitoring and compliance effort and an assessment of the impact of LLNL operations on the environment and the public. This first volume describes LLNL`s environmental impact and compliance activities and features descriptive and explanatory text, summary data tables, and plots showing data trends. The summary data include measures of the center of data, their spread or variability, and their extreme values. Chapters on monitoring air, sewage, surface water, ground water, soil and sediment, vegetation and foodstuff, and environmental radiation are present.

  15. Einstein equations with fluctuating volume

    Science.gov (United States)

    Dzhunushaliev, Vladimir; Quevedo, Hernando

    2017-07-01

    We develop a simple model to study classical fields on the background of a fluctuating spacetime volume. It is applied to formulate the stochastic Einstein equations with a perfect-fluid source. We investigate the particular case of a stochastic Friedmann-Lema\\^itre-Robertson-Walker cosmology, and show that the resulting field equations can lead to solutions which avoid the initial big bang singularity. By interpreting the fluctuations as the result of the presence of a quantum spacetime, we conclude that classical singularities can be avoided even within a stochastic model that include quantum effects in a very simple manner.

  16. BOX: One Minute Volume 3

    OpenAIRE

    Butler, Rose

    2009-01-01

    BOX is a digital short originally developed in 2004 documented on a 1920’s box camera. This early moving image work formed the basis of a practice which interrogates our experience of moving image through the remediation of analogue technology with new media. In 2009 it was included in One Minute Volume 3; a programme of artists moving image curated by Kerry Baldry including work by: Tony Hill, Tina Keane, Katherine Meynell, Kayla Parker and Stuart Moore, Dave Griffiths, Marty St Jam...

  17. Sequential exercise in triathletes: variations in GH and water loss.

    Directory of Open Access Journals (Sweden)

    Olivier Galy

    Full Text Available Growth hormone (GH may stimulate water loss during exercise by activating sweating. This study investigated GH secretion and water loss during sequential cycling and running, taking postural changes into account. The two exercise segments had similar durations and were performed at the same relative intensity to determine their respective contributions to water loss and the plasma volume variation noted in such trials. Eight elite triathletes first performed an incremental cycle test to assess maximal oxygen consumption. Then, the triathletes performed one of two trials in randomized order: constant submaximal cycling followed by treadmill running (C1-R2 or an inversed succession of running followed by cycling (R1-C2. Each segment of both trials was performed for 20 minutes at ∼75% of maximal oxygen consumption. The second trial, reversing the segment order of the first trial, took place two weeks later. During cycling, the triathletes used their own bicycles equipped with a profiled handlebar. Blood sampling (for GH concentrations, plasma viscosity and plasma volume variation was conducted at rest and after each segment while water loss was estimated from the post- and pre-measures. GH increases were significantly lower in R2 than C2 (72.2±50.1 vs. 164.0±157 ng x ml(-1 x min(-1, respectively; P<0.05. Water loss was significantly lower after C1-R2 than R1-C2 (1105±163 and 1235±153 ml, respectively; P<0.05. Plasma volume variation was significantly negative in C1 and R1 (-6.15±2.0 and -3.16±5.0%, respectively; P<0.05, not significant in C2, and significantly positive for seven subjects in R2 (4.05±3.1%. We concluded that the lower GH increases in R2 may have contributed to the smaller reduction in plasma volume by reducing sweating. Moreover, this lower GH response could be explained by the postural change during the transition from cycling to running. We recommend to pay particular attention to their hydration status during R1 which

  18. LGBTI Variations in Crime Reporting

    OpenAIRE

    Miles-Johnson, Toby

    2013-01-01

    Research shows that people vary in their willingness to report crime to police depending on the type of crime experienced, their gender, age, and their race or ethnicity. Whether or not lesbian, gay, bisexual, transgender, and intersex (LGBTI) and heterosexual people vary in their willingness to report crime to the police is not well understood in the extant literature. In this article, I examine variations in LGBTI re...

  19. Edge adaptive directional total variation

    Directory of Open Access Journals (Sweden)

    Hua Zhang

    2013-11-01

    Full Text Available The directional total variation (DTV model has been proposed very recently for image denoising. However, the DTV model works well when there is just one dominant direction in the image. In this Letter, the authors propose to make the DTV model adaptive to image edge direction so that the proposed model can handle images with several dominant directions. Experiment and comparison show the effectiveness of the proposed method.

  20. Resolving the impact of short-term variations in physical processes impacting on the spawning environment of eastern Baltic cod : application of a 3-D hydrodynamic model

    DEFF Research Database (Denmark)

    Hinrichsen, H.H.; St. John, Michael; Lehmann, A.;

    2002-01-01

    Variations in oxygen conditions below the permanent halocline influence the ecosystem of the Baltic Sea through a number of mechanisms. In this study, we examine the effects of physical forcing on variations in the volume of deep oxygenated water suitable for reproductive success of central Baltic...

  1. Representative volume element of asphalt pavement for electromagnetic measurements

    Directory of Open Access Journals (Sweden)

    Terhi Pellinen

    2015-02-01

    Full Text Available The motivation for this study was to investigate the representative volume element (RVE needed to correlate the nondestructive electromagnetic (EM measurements with the conventional destructive asphalt pavement quality control measurements. A large pavement rehabilitation contract was used as the test site for the experiment. Pavement cores were drilled from the same locations where the stationary and continuous Ground Penetrating Radar (GPR measurements were obtained. Laboratory measurements included testing the bulk density of cores using two methods, the surface-saturated dry method and determining bulk density by dimensions. Also, Vector Network Analyzer (VNA and the through specimen transmission configuration were employed at microwave frequencies to measure the reference dielectric constant of cores using two different footprint areas and therefore volume elements. The RVE for EM measurements turns out to be frequency dependent; therefore in addition to being dependent on asphalt mixture type and method of obtaining bulk density, it is dependent on the resolution of the EM method used. Then, although the average bulk property results agreed with theoretical formulations of higher core air void content giving a lower dielectric constant, for the individual cores there was no correlation for the VNA measurements because the volume element seizes deviated. Similarly, GPR technique was unable to capture the spatial variation of pavement air voids measured from the 150-mm drill cores. More research is needed to determine the usable RVE for asphalt.

  2. Generalized geometry in AdS/CFT and volume minimization

    Energy Technology Data Exchange (ETDEWEB)

    Gabella, Maxime, E-mail: maxime.gabella@cea.fr [Rudolf Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP (United Kingdom); Sparks, James, E-mail: sparks@maths.ox.ac.uk [Mathematical Institute, University of Oxford, 24-29 St Giles' , Oxford OX1 3LB (United Kingdom)

    2012-08-01

    We study the general structure of the AdS{sub 5}/CFT{sub 4} correspondence in type IIB string theory from the perspective of generalized geometry. We begin by defining a notion of 'generalized Sasakian geometry', which consists of a contact structure together with a differential system for three symplectic forms on the four-dimensional transverse space to the Reeb vector field. A generalized Sasakian manifold which satisfies an additional 'Einstein' condition provides a general supersymmetric AdS{sub 5} solution of type IIB supergravity with fluxes. We then show that the supergravity action restricted to a space of generalized Sasakian structures is simply the contact volume, and that its minimization determines the Reeb vector field for such a solution. We conjecture that this contact volume is equal to the inverse of the trial central charge whose maximization determines the R-symmetry of any four-dimensional N=1 superconformal field theory. This variational procedure allows us to compute the contact volumes for a predicted infinite family of solutions, and we find perfect agreement with the central charges and R-charges of BPS operators in the dual mass-deformed generalized conifold theories.

  3. Mineral density volume gradients in normal and diseased human tissues.

    Directory of Open Access Journals (Sweden)

    Sabra I Djomehri

    Full Text Available Clinical computed tomography provides a single mineral density (MD value for heterogeneous calcified tissues containing early and late stage pathologic formations. The novel aspect of this study is that, it extends current quantitative methods of mapping mineral density gradients to three dimensions, discretizes early and late mineralized stages, identifies elemental distribution in discretized volumes, and correlates measured MD with respective calcium (Ca to phosphorus (P and Ca to zinc (Zn elemental ratios. To accomplish this, MD variations identified using polychromatic radiation from a high resolution micro-computed tomography (micro-CT benchtop unit were correlated with elemental mapping obtained from a microprobe X-ray fluorescence (XRF using synchrotron monochromatic radiation. Digital segmentation of tomograms from normal and diseased tissues (N=5 per group; 40-60 year old males contained significant mineral density variations (enamel: 2820-3095 mg/cc, bone: 570-1415 mg/cc, cementum: 1240-1340 mg/cc, dentin: 1480-1590 mg/cc, cementum affected by periodontitis: 1100-1220 mg/cc, hypomineralized carious dentin: 345-1450 mg/cc, hypermineralized carious dentin: 1815-2740 mg/cc, and dental calculus: 1290-1770 mg/cc. A plausible linear correlation between segmented MD volumes and elemental ratios within these volumes was established, and Ca/P ratios for dentin (1.49, hypomineralized dentin (0.32-0.46, cementum (1.51, and bone (1.68 were observed. Furthermore, varying Ca/Zn ratios were distinguished in adapted compared to normal tissues, such as in bone (855-2765 and in cementum (595-990, highlighting Zn as an influential element in prompting observed adaptive properties. Hence, results provide insights on mineral density gradients with elemental concentrations and elemental footprints that in turn could aid in elucidating mechanistic processes for pathologic formations.

  4. Longitudinal Variations in Jupiter's Winds

    Science.gov (United States)

    Simon-Miller, Amy A.; Gierasch, P. J.; Tierney, G.

    2010-01-01

    Long-term studies of Jupiter's zonal wind field revealed temporal variations on the order of 20 to 40 m/s at many latitudes, greater than the typical data uncertainties of 1 to 10 m/s. No definitive periodicities were evident, however, though some latitudinally-confined signals did appear at periods relevant to the Quasi- Quadrennial Oscillation (Simon-Miller & Gierasch, Icarus, in press). As the QQO appears, from vertical temperature profiles, to propagate downward, it is unclear why a signal is not more obvious, unless other processes dominate over possibly weaker forcing from the QQO. An additional complication is that zonal wind profiles represent an average over some particular set of longitudes for an image pair and most data sets do not offer global wind coverage. Lien avoiding known features, such as the large anticyclonic vortices especially prevalent in the south, there can be distinct variations in longitude. We present results on the full wind field from Voyager and Cassini data, showing apparent longitudinal variations of up to 60 m/s or more. These are particularly obvious near disruptions such as the South Equatorial Disturbance, even when the feature itself is not clearly visible. These two dates represent very different states of the planet for comparison: Voyagers 1 & 2 flew by Jupiter shortly after a global upheaval, while many regions were in a disturbed state, while the Cassini view is typical of a more quiescent period present during much of the 1990s and early 2000s.

  5. Variational integrators for reduced magnetohydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Kraus, Michael, E-mail: michael.kraus@ipp.mpg.de [Max-Planck-Institut für Plasmaphysik, Boltzmannstraße 2, 85748 Garching (Germany); Technische Universität München, Zentrum Mathematik, Boltzmannstraße 3, 85748 Garching (Germany); Tassi, Emanuele, E-mail: tassi@cpt.univ-mrs.fr [Aix-Marseille Université, Université de Toulon, CNRS, CPT, UMR 7332, 163 avenue de Luminy, case 907, 13288 cedex 9 Marseille (France); Grasso, Daniela, E-mail: daniela.grasso@infm.polito.it [ISC-CNR and Politecnico di Torino, Dipartimento Energia, C.so Duca degli Abruzzi 24, 10129 Torino (Italy)

    2016-09-15

    Reduced magnetohydrodynamics is a simplified set of magnetohydrodynamics equations with applications to both fusion and astrophysical plasmas, possessing a noncanonical Hamiltonian structure and consequently a number of conserved functionals. We propose a new discretisation strategy for these equations based on a discrete variational principle applied to a formal Lagrangian. The resulting integrator preserves important quantities like the total energy, magnetic helicity and cross helicity exactly (up to machine precision). As the integrator is free of numerical resistivity, spurious reconnection along current sheets is absent in the ideal case. If effects of electron inertia are added, reconnection of magnetic field lines is allowed, although the resulting model still possesses a noncanonical Hamiltonian structure. After reviewing the conservation laws of the model equations, the adopted variational principle with the related conservation laws is described both at the continuous and discrete level. We verify the favourable properties of the variational integrator in particular with respect to the preservation of the invariants of the models under consideration and compare with results from the literature and those of a pseudo-spectral code.

  6. Variational integrators for reduced magnetohydrodynamics

    Science.gov (United States)

    Kraus, Michael; Tassi, Emanuele; Grasso, Daniela

    2016-09-01

    Reduced magnetohydrodynamics is a simplified set of magnetohydrodynamics equations with applications to both fusion and astrophysical plasmas, possessing a noncanonical Hamiltonian structure and consequently a number of conserved functionals. We propose a new discretisation strategy for these equations based on a discrete variational principle applied to a formal Lagrangian. The resulting integrator preserves important quantities like the total energy, magnetic helicity and cross helicity exactly (up to machine precision). As the integrator is free of numerical resistivity, spurious reconnection along current sheets is absent in the ideal case. If effects of electron inertia are added, reconnection of magnetic field lines is allowed, although the resulting model still possesses a noncanonical Hamiltonian structure. After reviewing the conservation laws of the model equations, the adopted variational principle with the related conservation laws is described both at the continuous and discrete level. We verify the favourable properties of the variational integrator in particular with respect to the preservation of the invariants of the models under consideration and compare with results from the literature and those of a pseudo-spectral code.

  7. Petroleum supply annual 1994. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-05-22

    The Petroleum Supply Annual (PSA) contains information on the supply and disposition of crude oil and petroleum products. The publication reflects data that were collected from the petroleum industry during 1994 through annual and monthly surveys. The PSA is divided into two volumes. This first volume contains four sections: Summary Statistics, Detailed Statistics, Refinery Capacity, and Oxygenate Capacity each with final annual data. The second volume contains final statistics for each month of 1994, and replaces data previously published in the Petroleum Supply Monthly (PSM). The tables in Volumes 1 and 2 are similarly numbered to facilitate comparison between them. Below is a description of each section in Volume 1 of the PSA.

  8. Petroleum supply annual 1993. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    1994-06-01

    The Petroleum Supply Annual (PSA) contains information on the supply and disposition of crude oil and petroleum products. The publication reflects data that were collected from the petroleum industry during 1993 through annual and monthly surveys. The PSA is divided into two volumes. This first volume contains four sections: Summary Statistics, Detailed Statistics, Refinery Capacity, and Oxygenate Capacity each with final annual data. The second volume contains final statistics for each month of 1993, and replaces data previously published in the Petroleum Supply Monthly (PSM). The tables in Volumes 1 and 2 are similarly numbered to facilitate comparison between them. Below is a description of each section in Volume 1 of the PSA.

  9. Tumor volume in subcutaneous mouse xenografts measured by microCT is more accurate and reproducible than determined by 18F-FDG-microPET or external caliper

    DEFF Research Database (Denmark)

    Jensen, Mette Munk; Jørgensen, Jesper Tranekjaer; Binderup, Tina;

    2008-01-01

    and reproducible measures of tumor size in mice compared with caliper measurements. Furthermore, we evaluated the accuracy of tumor volume determined from 18F-fluorodeoxyglucose (18F-FDG) PET. METHODS: Subcutaneously implanted human breast adenocarcinoma cells in NMRI nude mice served as tumor model. Tumor volume...... systematic bias compared to reference volume. Coefficients of variation for intra-observer variation were 7% and 14% for microCT and caliper measurements, respectively. Regression coefficients between observers were 0.97 for microCT and 0.91 for caliper measurements. CONCLUSION: MicroCT was more accurate...

  10. 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....

  11. Volume calculation of CT lung lesions based on Halton low-discrepancy sequences

    Science.gov (United States)

    Li, Shusheng; Wang, Liansheng; Li, Shuo

    2017-03-01

    Volume calculation from the Computed Tomography (CT) lung lesions data is a significant parameter for clinical diagnosis. The volume is widely used to assess the severity of the lung nodules and track its progression, however, the accuracy and efficiency of previous studies are not well achieved for clinical uses. It remains to be a challenging task due to its tight attachment to the lung wall, inhomogeneous background noises and large variations in sizes and shape. In this paper, we employ Halton low-discrepancy sequences to calculate the volume of the lung lesions. The proposed method directly compute the volume without the procedure of three-dimension (3D) model reconstruction and surface triangulation, which significantly improves the efficiency and reduces the complexity. The main steps of the proposed method are: (1) generate a certain number of random points in each slice using Halton low-discrepancy sequences and calculate the lesion area of each slice through the proportion; (2) obtain the volume by integrating the areas in the sagittal direction. In order to evaluate our proposed method, the experiments were conducted on the sufficient data sets with different size of lung lesions. With the uniform distribution of random points, our proposed method achieves more accurate results compared with other methods, which demonstrates the robustness and accuracy for the volume calculation of CT lung lesions. In addition, our proposed method is easy to follow and can be extensively applied to other applications, e.g., volume calculation of liver tumor, atrial wall aneurysm, etc.

  12. Relationship between Plasma Albumin Concentration and Plasma Volume in 5 Inbred Rat Strains.

    Science.gov (United States)

    Rose, Rajiv; Klemcke, Harold G

    2015-09-01

    Using the Evans Blue procedure, we previously found strain-related differences in plasma volumes in 5 inbred rat strains. Because albumin binds strongly with Evans blue, this protein is important in the Evans blue method of plasma volume determination. Therefore, we speculated that interstrain differences in plasma albumin concentration (PAC) could distort calculated plasma volumes. To address this concern, we used ELISA techniques to measure PAC in these inbred rat strains. In study A, the blood volume was measured by using Evans blue dye, and albumin was measured at the start of hemorrhage. In study B, blood volume was not measured, and albumin was measured twice, near the start and end of hemorrhage (approximately 14 min apart). Neither study revealed any interstrain differences in PAC, which decreased after hemorrhage in all 5 strains. No correlation was found between PAC and plasma volume, survival time, blood lactate, or blood base excess. Percentage changes in PAC during hemorrhage were greater in salt-sensitive compared with Lewis rats. Moreover, these percentage changes were associated with survival time in Fawn hooded hypertensive rats. Our data show that the plasma volumes we measured previously were not misrepresented due to variations in PAC.

  13. Rapid estimate of solid volume in large tuff cores using a gas pycnometer

    Energy Technology Data Exchange (ETDEWEB)

    Thies, C. [ed.; Geddis, A.M.; Guzman, A.G. [and others

    1996-09-01

    A thermally insulated, rigid-volume gas pycnometer system has been developed. The pycnometer chambers have been machined from solid PVC cylinders. Two chambers confine dry high-purity helium at different pressures. A thick-walled design ensures minimal heat exchange with the surrounding environment and a constant volume system, while expansion takes place between the chambers. The internal energy of the gas is assumed constant over the expansion. The ideal gas law is used to estimate the volume of solid material sealed in one of the chambers. Temperature is monitored continuously and incorporated into the calculation of solid volume. Temperature variation between measurements is less than 0.1{degrees}C. The data are used to compute grain density for oven-dried Apache Leap tuff core samples. The measured volume of solid and the sample bulk volume are used to estimate porosity and bulk density. Intrinsic permeability was estimated from the porosity and measured pore surface area and is compared to in-situ measurements by the air permeability method. The gas pycnometer accommodates large core samples (0.25 m length x 0.11 m diameter) and can measure solid volume greater than 2.20 cm{sup 3} with less than 1% error.

  14. Reduced central blood volume in cirrhosis

    DEFF Research Database (Denmark)

    Bendtsen, F; Henriksen, Jens Henrik Sahl; Sørensen, T I

    1989-01-01

    for measuring the central blood volume. We have developed a method that enables us to determine directly the central blood volume, i.e., the blood volume in the heart cavities, lungs, and central arterial tree. In 60 patients with cirrhosis and 16 control subjects the central blood volume was assessed according......The pathogenesis of ascites formation in cirrhosis is uncertain. It is still under debate whether the effective blood volume is reduced (underfilling theory) or whether the intravascular compartment is expanded (overflow theory). This problem has not yet been solved because of insufficient tools...... to the kinetic theory as the product of cardiac output and mean transit time of the central vascular bed. Central blood volume was significantly smaller in patients with cirrhosis than in controls (mean 21 vs. 27 ml/kg estimated ideal body weight, p less than 0.001; 25% vs. 33% of the total blood volume, p less...

  15. Physiology of cell volume regulation in vertebrates

    DEFF Research Database (Denmark)

    Hoffmann, Else K; Lambert, Ian H; Pedersen, Stine F

    2009-01-01

    cases, activation of volume regulatory osmolyte transport. After acute swelling, cell volume is regulated by the process of regulatory volume decrease (RVD), which involves the activation of KCl cotransport and of channels mediating K(+), Cl(-), and taurine efflux. Conversely, after acute shrinkage......, cell volume is regulated by the process of regulatory volume increase (RVI), which is mediated primarily by Na(+)/H(+) exchange, Na(+)-K(+)-2Cl(-) cotransport, and Na(+) channels. Here, we review in detail the current knowledge regarding the molecular identity of these transport pathways...... and their regulation by, e.g., membrane deformation, ionic strength, Ca(2+), protein kinases and phosphatases, cytoskeletal elements, GTP binding proteins, lipid mediators, and reactive oxygen species, upon changes in cell volume. We also discuss the nature of the upstream elements in volume sensing in vertebrate...

  16. Taurine Homeostasis and Volume Control.

    Science.gov (United States)

    Pasantes-Morales, Herminia

    2017-01-01

    Taurine content is high (mM) in mammalian brain. By its major role as an osmolyte, taurine contributes to the cell volume control, which is particularly critical in the brain. Taurine participates in osmotic adjustments required to maintain the organization and size of intracellular compartments. It counteracts volume fluctuations in unbalanced transmembrane fluxes of ions and neurotransmitters, preserving the functional synaptic contacts. Taurine has a key role in the long-term adaptation to chronic hyponatremia as well as in other pathologies leading to brain edema. Together with other osmolytes, taurine corrects cell shrinkage, preventing mysfunction of organelles and apoptosis. Swelling corrective taurine efflux occurs through a leak pathway, likely formed by LCRR8 protein isoforms. Shrinkage-activated influx comes largely by the increased activity of the Na(+)/Cl(-)-dependent transporter. The brain taurine pool results from the equilibrium between (i) dietary intake and active transport into the cell, (ii) synthesis in the brain itself or import of that synthesized elsewhere, and (iii) leak and posterior excretion. The interplay between these elements preserves brain taurine homeostasis in physiological conditions and permits the proper adjustments upon deviations of normal in the internal/external environment.

  17. Strategies to evaluate the impact of rectal volume on prostate motion during three-dimensional conformal radiotherapy for prostate cancer

    Directory of Open Access Journals (Sweden)

    Ana Paula Diniz Fortuna Poli

    2016-02-01

    Full Text Available Abstract Objective: To evaluate the rectal volume influence on prostate motion during three-dimensional conformal radiotherapy (3D-CRT for prostate cancer. Materials and Methods: Fifty-one patients with prostate cancer underwent a series of three computed tomography scans including an initial planning scan and two subsequent scans during 3D-CRT. The organs of interest were outlined. The prostate contour was compared with the initial CT images considering the anterior, posterior, superior, inferior and lateral edges of the organ. Variations in the anterior limits and volume of the rectum were assessed and correlated with prostate motion in the anteroposterior direction. Results: The maximum range of prostate motion was observed in the superoinferior direction, followed by the anteroposterior direction. A significant correlation was observed between prostate motion and rectal volume variation ( p = 0.037. A baseline rectal volume superior to 70 cm3 had a significant influence on the prostate motion in the anteroposterior direction ( p = 0.045. Conclusion: The present study showed a significant interfraction motion of the prostate during 3D-CRT with greatest variations in the superoinferior and anteroposterior directions, and that a large rectal volume influences the prostate motion with a cutoff value of 70 cm3. Therefore, the treatment of patients with a rectal volume > 70 cm3 should be re-planned with appropriate rectal preparation.

  18. Strategies to evaluate the impact of rectal volume on prostate motion during three-dimensional conformal radiotherapy for prostate cancer*

    Science.gov (United States)

    Poli, Ana Paula Diniz Fortuna; Dias, Rodrigo Souza; Giordani, Adelmo José; Segreto, Helena Regina Comodo; Segreto, Roberto Araujo

    2016-01-01

    Objective To evaluate the rectal volume influence on prostate motion during three-dimensional conformal radiotherapy (3D-CRT) for prostate cancer. Materials and Methods Fifty-one patients with prostate cancer underwent a series of three computed tomography scans including an initial planning scan and two subsequent scans during 3D-CRT. The organs of interest were outlined. The prostate contour was compared with the initial CT images considering the anterior, posterior, superior, inferior and lateral edges of the organ. Variations in the anterior limits and volume of the rectum were assessed and correlated with prostate motion in the anteroposterior direction. Results The maximum range of prostate motion was observed in the superoinferior direction, followed by the anteroposterior direction. A significant correlation was observed between prostate motion and rectal volume variation (p = 0.037). A baseline rectal volume superior to 70 cm3 had a significant influence on the prostate motion in the anteroposterior direction (p = 0.045). Conclusion The present study showed a significant interfraction motion of the prostate during 3D-CRT with greatest variations in the superoinferior and anteroposterior directions, and that a large rectal volume influences the prostate motion with a cutoff value of 70 cm3. Therefore, the treatment of patients with a rectal volume > 70 cm3 should be re-planned with appropriate rectal preparation. PMID:26929456

  19. Variation in wood fibre traits among eight populations of Dipterocarpus indicus in Western Ghats, India.

    Science.gov (United States)

    Prasad, A G Devi; Al-Sagheer, Nageeb A

    2012-03-01

    Wood elements and anatomical ratio of Dipterocarpus indicus were studied to evaluate variation among populations and to recommend for end selection. The variation of wood element [fibre length (FL), fibre diameter (FD), lumen diameter (LD), cell wall thickness (CWT), double wall thickness (DWT), and lumen volume (LV)] and anatomical ratio [fibre lumen area (FLA), slenderness ratio (SR) and runkel ratio (RR)] were investigated in a girth class of 100 - 120 cm among eight populations of Dipterocarpus indicus in Western Ghats, India. The study revealed a significant variations in FL (0.2426), FD (4.7019), LD (3.1689), CWT (2.7104), DWT and (5.4298) among populations. The variations in anatomical ratios were significant among populations except in case of LV. The causes of variations among populations in their wood traits were attributed to the site factors. The interaction between genetic makeup of wood traits combined with effects of edaphic, local and regional climatic conditions reflect the amount of variation among populations. The highest coefficient of variation (CV %) for FL, FD, CWT and DWT was recorded in population of Gundya whereas low coefficient of variation were recorded in the population of Makuta (FL), Devimane (FD, CWT and DWT), and Sampaje (LD). The wood of Dipterocarpus indicus was found undesirable for pulp wood but can be utilized for plywood timbers.

  20. Nutrient deprivation induces property variations in spider gluey silk.

    Directory of Open Access Journals (Sweden)

    Sean J Blamires

    Full Text Available Understanding the mechanisms facilitating property variability in biological adhesives may promote biomimetic innovations. Spider gluey silks such as the spiral threads in orb webs and the gumfoot threads in cobwebs, both of which comprise of an axial thread coated by glue, are biological adhesives that have variable physical and chemical properties. Studies show that the physical and chemical properties of orb web gluey threads change when spiders are deprived of food. It is, however, unknown whether gumfoot threads undergo similar property variations when under nutritional stress. Here we tested whether protein deprivation induces similar variations in spiral and gumfoot thread morphology and stickiness. We manipulated protein intake for the orb web spider Nephila clavipes and the cobweb spider Latrodectus hesperus and measured the diameter, glue droplet volume, number of droplets per mm, axial thread width, thread stickiness and adhesive energy of their gluey silks. We found that the gluey silks of both species were stickier when the spiders were deprived of protein than when the spiders were fed protein. In N. clavipes a concomitant increase in glue droplet volume was found. Load-extension curves showed that protein deprivation induced glue property variations independent of the axial thread extensions in both species. We predicted that changes in salt composition of the glues were primarily responsible for the changes in stickiness of the silks, although changes in axial thread properties might also contribute. We, additionally, showed that N. clavipes' glue changes color under protein deprivation, probably as a consequence of changes to its biochemical composition.

  1. An association between human hippocampal volume and topographical memory in healthy young adults.

    Directory of Open Access Journals (Sweden)

    Tom eHartley

    2012-12-01

    Full Text Available The association between human hippocampal structure and topographical memory was investigated in healthy adults (N=30. Structural MR images were acquired, and voxel-based morphometry (VBM was used to estimate local gray matter volume throughout the brain. A complementary automated mesh-based segmentation approach was used to independently isolate and measure specified structures including the hippocampus. Topographical memory was assessed using a version of the Four Mountains Task, a short test designed to target hippocampal spatial function. Each item requires subjects to briefly study a landscape scene before recognizing the depicted place from a novel viewpoint and under altered non-spatial conditions when presented amongst similar alternative scenes. Positive correlations between topographical memory performance and hippocampal volume were observed in both VBM and segmentation-based analyses. Score on the topographical memory task was also correlated with the volume of some subcortical structures, extra-hippocampal gray matter and total brain volume, with the most robust and extensive covariation seen in circumscribed neocortical regions in the insula and anterior temporal lobes. Taken together with earlier findings, the results suggest that global variations in brain morphology affect the volume of the hippocampus and its specific contribution to topographical memory. We speculate that behavioral variation might arise directly through the impact of resource constraints on spatial representations in the hippocampal formation and its inputs, and perhaps indirectly through an increased reliance on non-allocentric strategies.

  2. Surface Freshwater Storage Variations in the Orinoco Floodplains Using Multi-Satellite Observations

    Directory of Open Access Journals (Sweden)

    Frédéric Frappart

    2014-12-01

    Full Text Available Variations in surface water extent and storage are poorly characterized from regional to global scales. In this study, a multi-satellite approach is proposed to estimate the water stored in the floodplains of the Orinoco Basin at a monthly time-scale using remotely-sensed observations of surface water from the Global Inundation Extent Multi-Satellite (GIEMS and stages from Envisat radar altimetry. Surface water storage variations over 2003–2007 exhibit large interannual variability and a strong seasonal signal, peaking during summer, and associated with the flood pulse. The volume of surface water storage in the Orinoco Basin was highly correlated with the river discharge at Ciudad Bolivar (R = 0.95, the closest station to the mouth where discharge was estimated, although discharge lagged one month behind storage. The correlation remained high (R = 0.73 after removing seasonal effects. Mean annual variations in surface water volume represented ~170 km3, contributing to ~45% of the Gravity Recovery and Climate Experiment (GRACE-derived total water storage variations and representing ~13% of the total volume of water that flowed out of the Orinoco Basin to the Atlantic Ocean.

  3. First impressions: geographic variation in media messages during the first phase of ACA implementation.

    Science.gov (United States)

    Gollust, Sarah E; Barry, Colleen L; Niederdeppe, Jeff; Baum, Laura; Fowler, Erika Franklin

    2014-12-01

    Many Americans will learn about the implementation of the Patient Protection and Affordable Care Act (ACA) through the mass media. We examined geographic variation in the volume and content of mass media during the initial two-week rollout of the new health insurance marketplaces in October 2013 across 210 US media markets, using data from the Wesleyan Media Project. We found substantial geographic variation in the volume and tone of insurance product advertisements, political advertisements, and news coverage of the ACA marketplaces. News coverage of the ACA airing in media markets located in states operating federal or partnership marketplaces was more negative than coverage airing in markets located in states running their own marketplaces. Intrastate variation in media volume and content was also substantial and appears distinguishable from the local political climate. Variation in exposure to media messages likely affects public sentiment regarding the ACA and could contribute to geographic differences in insurance enrollment and public perceptions of US health care options. Researchers and policy makers evaluating the implementation of the ACA-and insurance enrollment in the marketplaces in particular-should consider addressing media influences.

  4. Optimal estimation of zonal velocity and transport through Luzon Strait using variational data assimilation technique

    Institute of Scientific and Technical Information of China (English)

    LAN Jian; BAO Xianwen; GAO Guoping

    2004-01-01

    A P-vector method was optimized using variational data assimilation technique, with which the vertical structures and seasonal variations of zonal velocities and transports were investigated. The results showed that westward and eastward flowes occur in the Luzon Strait in the same period in a year. However the net volume transport is westward. In the upper level (0m - -500m),the westward flow exits in the middle and south of the Luzon Strait, and the eastward flow exits in the north. There are two centers of westward flow and one center of eastward flow. In the middle of the Luzon Strait, westward and eastward flowes appear alternately in vertical direction. The westward flow strengthens in winter and weakens in summer. The net volume transport is strong in winter (5.53 Sv) but weak in summer (0.29 Sv). Except in summer, the volume transport in the upper level accounts for more than half of the total volume transport (0m - bottom). In summer, the net volume transport in the upper level is eastward (1.01 Sv), but westward underneath.

  5. 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.

  6. Site Environmental Report for 2009, Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Suying

    2010-08-19

    Volume II of the Site Environmental Report for 2009 is provided by Ernest Orlando Lawrence Berkeley National Laboratory as a supplemental appendix to Volume I, which contains the body of the report. Volume II contains the environmental monitoring and sampling data used to generate summary results of routine and nonroutine sampling at the Laboratory, except for groundwater sampling data, which may be found in the reports referred to in Chapter 4 of Volume I. The results from sample collections are more comprehensive in Volume II than in Volume I: for completeness, all results from sample collections that began or ended in calendar year (CY) 2009 are included in this volume. However, the samples representing CY 2008 data have not been used in the summary results that are reported in Volume I. (For example, although ambient air samples collected on January 6, 2009, are presented in Volume II, they represent December 2008 data and are not included in Table 4-2 in Volume I.) When appropriate, sampling results are reported in both conventional and International System (SI) units. For some results, the rounding procedure used in data reporting may result in apparent differences between the numbers reported in SI and conventional units. (For example, stack air tritium results reported as < 1.5 Bq/m3 are shown variously as < 39 and < 41 pCi/m3. Both of these results are rounded correctly to two significant digits.)

  7. 30th International School of Mathematics "G Stampacchia" : Equilibrium Problems and Variational Models "Ettore Majorana"

    CERN Document Server

    Giannessi, Franco; Maugeri, Antonino; Equilibrium Problems and Variational Models

    2000-01-01

    The volume, devoted to variational analysis and its applications, collects selected and refereed contributions, which provide an outline of the field. The meeting of the title "Equilibrium Problems and Variational Models", which was held in Erice (Sicily) in the period June 23 - July 2 2000, was the occasion of the presentation of some of these papers; other results are a consequence of a fruitful and constructive atmosphere created during the meeting. New results, which enlarge the field of application of variational analysis, are presented in the book; they deal with the vectorial analysis, time dependent variational analysis, exact penalization, high order deriva­ tives, geometric aspects, distance functions and log-quadratic proximal methodology. The new theoretical results allow one to improve in a remarkable way the study of significant problems arising from the applied sciences, as continuum model of transportation, unilateral problems, multicriteria spatial price models, network equilibrium...

  8. Determination of Partial Molar Volumes of EPA and DHA Ethyl Esters in Supercritical Carbon Dioxide

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The use of supercritical-fluid chromatography for determining partial molar volumes of ethyl esters of cis-5,8,11,14,17-eicosapentaenoic acid (EPA) and cis -4,7,10,13,16,19- docosa-hexaenoic acid (DHA) in supercritical carbon dioxide is presented and discussed. Partial molar volumes of EPA and DHA esters are obtained from the variation of the retention properties with the density of mobile phase at 313.15 K, 323.15 K, 333.15 K and in the pressure range from 9 MPa to 21 MPa.

  9. Deptermination of Partial Molar Volumes of EPA and DHA Ethyl Esters in Supercritical Carbon Dioxide

    Institute of Scientific and Technical Information of China (English)

    MeiHUANG; XianDaWANG; 等

    2002-01-01

    The use of supercritical-fluid shromatogrphy for determining partial molar volumes of ethyl esters of cis-5,8,11,14,17-eicosapentaenoic acid (EPA) and cis-4,7,10,13,16,19-docosa-hexaenoic acid(DHA) in supercritical carbon dioxide is presented and discussed. Partial molar volumes of EPA and DHA esters are obtained from the variation of the retention properties with the density of mobile phase at 313.15K,323.15K,333.15K and in the pressure range from 9 MPa to 21 MPa.

  10. Definition of the planning target volume of organs at risk (planning organ at risk volume, PRV) in case of radiotherapy of the ORL sphere; Definition d'un volume cible previsionnel d'organe a risque (Planning organ at risk volume, PRV) en cas de radiotherapie de la sphere ORL

    Energy Technology Data Exchange (ETDEWEB)

    Louvel, G.; Le Prise, E.; Williaume, D.; De Crevoisier, R. [Centre Eugene-Marquis, 35 - Rennes (France); Cazoulat, G.; Lafond, C.; Simon, A.; Haigron, P.; De Crevoisier, R. [Universite de Rennes 1 LTSI, 35 - Rennes (France); Inserm U642, 35 - Rennes (France); Li, B.S. [Shandong Cancer Hospital, Jinan (China); Boisselier, P. [Centre Val d' Aurelle, 34 - Montpellier (France)

    2010-10-15

    The authors report a study which aimed at quantifying anatomic variations of organs at risk and their dosimetric impact, and at computing appropriate margins around organs at risk to generate planning target volumes of organs at risk, representative of the dose delivered to organs at risk. Nine patients have been treated for a locally advanced ORL cancer by a concomitant combination of radiotherapy and chemotherapy, with weekly scanographies during the radiotherapy. Registration has been successfully performed according to three bone references. Volume modifications and motions have been computed to define the margins around three organs at risk. Short communication

  11. Variational collocation on finite intervals

    Energy Technology Data Exchange (ETDEWEB)

    Amore, Paolo [Facultad de Ciencias, Universidad de Colima, Bernal DIaz del Castillo 340, Colima, Colima (Mexico); Cervantes, Mayra [Facultad de Ciencias, Universidad de Colima, Bernal DIaz del Castillo 340, Colima, Colima (Mexico); Fernandez, Francisco M [INIFTA (Conicet, UNLP), Diag. 113 y 64 S/N, Sucursal 4, Casilla de Correo 16, 1900 La Plata (Argentina)

    2007-10-26

    In this paper, we study a set of functions, defined on an interval of finite width, which are orthogonal and which reduce to the sinc functions when the appropriate limit is taken. We show that these functions can be used within a variational approach to obtain accurate results for a variety of problems. We have applied them to the interpolation of functions on finite domains and to the solution of the Schroedinger equation, and we have compared the performance of the present approach with others.

  12. Genetic variation in dieback resistance

    DEFF Research Database (Denmark)

    Lobo, Albin; Hansen, Jon Kehlet; McKinney, Lea Vig

    2014-01-01

    -eastern Zealand, Denmark, and confirmed the presence of substantial genetic variation in ash dieback susceptibility. The average crown damage increased in the trial from 61% in 2009 to 66% in 2012 and 72% in 2014, while the estimated heritability was 0.42 in both 2009 and 2012 but increased to 0.53 in 2014....... Genetic correlation between assessments was 0.88 between 2009 and 2012 and 0.91 between 2009 and 2014, suggesting fairly good possibilities for early selection of superior genotypes in the presence of high infection levels in the trial. The level of crown damage had strong negative effect on growth...

  13. Systematic variations in divergence angle

    CERN Document Server

    Okabe, Takuya

    2012-01-01

    Practical methods for quantitative analysis of radial and angular coordinates of leafy organs of vascular plants are presented and applied to published phyllotactic patterns of various real systems from young leaves on a shoot tip to florets on a flower head. The constancy of divergence angle is borne out with accuracy of less than a degree. It is shown that apparent fluctuations in divergence angle are in large part systematic variations caused by the invalid assumption of a fixed center and/or by secondary deformations, while random fluctuations are of minor importance.

  14. Genetic variation and human longevity.

    Science.gov (United States)

    Soerensen, Mette

    2012-05-01

    The overall aim of the PhD project was to elucidate the association of human longevity with genetic variation in major candidate genes and pathways of longevity. Based on a thorough literature and database search we chose to apply a pathway approach; to explore variation in genes composing the DNA damage signaling, DNA repair, GH/IGF-1/insulin signaling and pro-/antioxidant pathways. In addition, 16 genes which did not belong to the core of either pathway, however recurrently regarded as candidate genes of longevity (e.g. APOE), were included. In this way a total of 168 genes were selected for investigation. We decided to explore the genetic variation in the form of single nucleotide polymorphisms (SNPs), a highly investigated type of genetic variation. SNPs having potential functional impact (e.g. affecting binding of transcription factors) were identified, so were specific SNPs in the candidate genes previously published to be associated with human longevity. To cover the majority of the common genetic variation in the 168 gene regions (encoding regions plus 5,000 bp upstream and 1,000 downstream) we applied the tagging SNP approach via the HapMap Consortium. Consequently 1,536 SNPs were selected. The majority of the previous publications on genetic variation and human longevity had employed a case-control study design, e.g. comparing centenarians to middle-aged controls. This type of study design is somehow prone to bias introduced by for instance cohort effects, i.e. differences in characteristics of cases and controls, a kind of bias which is avoided when a prospective cohort is under study. Therefore, we chose to investigate 1,200 individuals of the Danish 1905 birth cohort, which have been followed since 1998 when the members were 92-93 years old. The genetic contribution to human longevity has been estimated to be most profound during the late part of life, thus these oldest-old individuals are excellent for investigating such effect. The follow-up survival

  15. Space resources. Volume 3: Materials

    Energy Technology Data Exchange (ETDEWEB)

    Mckay, M.F.; Mckay, D.S.; Duke, M.B.

    1992-01-01

    Space Resources addresses the issues of using space resources to support life on the Moon and for exploration of Mars. This volume - Materials - covers a number of technical and policy issues regarding the materials in space (mainly lunar and asteroidal) which can be used to support space operations. In part 1, nature and location of these materials, exploration strategy, evaluation criteria, and the technical means to collect or mine these materials is discussed. A baseline lunar mine and the basics of asteroid mining are presented and critiqued. In part 2, the beneficiation of ores and the extraction of such materials as oxygen, metals, and the makings of concrete are discussed. In part 3, the manufacturing and fabrication of nonterrestrial products are discussed. The economic tradeoffs between bringing needed products from Earth and making these products on location in space is considered. Separate abstracts have been prepared for papers in this report.

  16. Information architecture. Volume 3: Guidance

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-04-01

    The purpose of this document, as presented in Volume 1, The Foundations, is to assist the Department of Energy (DOE) in developing and promulgating information architecture guidance. This guidance is aimed at increasing the development of information architecture as a Departmentwide management best practice. This document describes departmental information architecture principles and minimum design characteristics for systems and infrastructures within the DOE Information Architecture Conceptual Model, and establishes a Departmentwide standards-based architecture program. The publication of this document fulfills the commitment to address guiding principles, promote standard architectural practices, and provide technical guidance. This document guides the transition from the baseline or defacto Departmental architecture through approved information management program plans and budgets to the future vision architecture. This document also represents another major step toward establishing a well-organized, logical foundation for the DOE information architecture.

  17. ATF2 Proposal Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Grishanov, B.I.; Logachev, P.; Podgorny, F.; Telnov, V.; /Novosibirsk, IYF; Angal-Kalinin, D.; Jones, J.; Kalinin, A.; /Daresbury; Napoly, O.; Payet, J.; /DAPNIA, Saclay; Braun, H.H.; Schulte, D.; Zimmermann, F.; /CERN; Appleby, R.; Barlow, R.; Bailey, I.; Jenner, L.; Jones, R.; Kourevlev, G.; /Cockcroft Inst.; Elsen, E.; Vogel, V.; Walker, N.; /DESY

    2006-02-27

    For achieving the high luminosity required at the International Linear Collider (ILC), it is critical to focus the beams to nanometer size with the ILC Beam Delivery System (BDS), and to maintain the beam collision with a nanometer-scale stability. To establish the technologies associated with this ultra-high precision beam handling, it has been proposed to implement an ILC-like final focus optics in an extension of the existing extraction beamline of ATF at KEK. The ATF is considered to be the best platform for this exercise, since it provides an adequate ultra-low emittance electron beam in a manner dedicated to the development of ILC. The two major goals for this facility, called ATF2, are: (A) Achievement of a 37 nm beam size, and (B) control of beam position down to 2 nm level. The scientific justification for the ATF2 project and its technical design have been described in Volume 1 of the ATF2 Proposal [1]. We present here Volume 2 of the ATF2 Proposal, in which we present specifics of the construction plans and the group organization to execute the research programs at ATF2. The sections in this report have been authored by relevant ATF2 subgroups within the International ATF Collaboration. The time line of the project is described in Section 2. Section 3 discuss the structure of the international collaboration. Sections 4 and 5 discuss budget considerations, which are presented as well as the design and construction tasks to be shared by the international collaboration at ATF2. Concluding remarks have been contributed by Dr. Ewan Paterson, Chair of the International Collaboration Board of the ATF collaboration.

  18. Effects of Early Bedside Cycle Exercise on Intracranial Pressure and Systemic Hemodynamics in Critically Ill Patients in a Neurointensive Care Unit.

    Science.gov (United States)

    Thelandersson, Anneli; Nellgård, Bengt; Ricksten, Sven-Erik; Cider, Åsa

    2016-12-01

    Physiotherapy is an important part of treatment after severe brain injuries and stroke, but its effect on intracranial and systemic hemodynamics is minimally investigated. Therefore, the aim of this study was to assess the effects of an early bedside cycle exercise on intracranial and systemic hemodynamics in critically ill patients when admitted to a neurointensive care unit (NICU). Twenty critically ill patients suffering from brain injuries or stroke were included in this study performed in the NICU at Sahlgrenska University Hospital. One early implemented exercise session was performed using a bedside cycle ergometer for 20 min. Intracranial and hemodynamic variables were measured two times before, three times during, and two times after the bedside cycling exercise. Analyzed variables were intracranial pressure (ICP), cerebral perfusion pressure (CPP), mean arterial blood pressure (MAP), heart rate (HR), peripheral oxygen saturation (SpO2), cardiac output (CO), stroke volume (SV), and stroke volume variation (SVV). The cycling intervention was conducted within 7 ± 5 days after admission to the NICU. Cycle exercise increased MAP (p = 0.029) and SV (p = 0.003) significantly. After exercise CO, SV, MAP, and CPP decreased significantly, while no changes in HR, SVV, SpO2, or ICP were noted when compared to values obtained during exercise. There were no differences in data obtained before versus after exercise. Early implemented exercise with a bedside cycle ergometer, for patients with severe brain injuries or stroke when admitted to a NICU, is considered to be a clinically safe procedure.

  19. Goal-Directed Resuscitation Aiming Cardiac Index Masks Residual Hypovolemia: An Animal Experiment

    Directory of Open Access Journals (Sweden)

    Krisztián Tánczos

    2015-01-01

    Full Text Available The aim of this study was to compare stroke volume (SVI to cardiac index (CI guided resuscitation in a bleeding-resuscitation experiment. Twenty six pigs were randomized and bled in both groups till baseline SVI (Tbsl dropped by 50% (T0, followed by resuscitation with crystalloid solution until initial SVI or CI was reached (T4. Similar amount of blood was shed but animals received significantly less fluid in the CI-group as in the SVI-group: median = 900 (interquartile range: 850–1780 versus 1965 (1584–2165 mL, p=0.02, respectively. In the SVI-group all variables returned to their baseline values, but in the CI-group animals remained underresuscitated as indicated by SVI, heart rate (HR and stroke volume variation (SVV, and central venous oxygen saturation (ScvO2 at T4 as compared to Tbsl: SVI = 23.8 ± 5.9 versus 31.4 ± 4.7 mL, HR: 117 ± 35 versus 89 ± 11/min SVV: 17.4 ± 7.6 versus 11.5 ± 5.3%, and ScvO2: 64.1 ± 11.6 versus 79.2 ± 8.1%, p<0.05, respectively. Our results indicate that CI-based goal-directed resuscitation may result in residual hypovolaemia, as bleeding caused stress induced tachycardia “normalizes” CI, without restoring adequate SVI. As the SVI-guided approach normalized most hemodynamic variables, we recommend using SVI instead of CI as the primary goal of resuscitation during acute bleeding.

  20. Assessment of left atrial volume and mechanical function in ischemic heart disease: a multi slice computed tomography study

    DEFF Research Database (Denmark)

    Kühl, Jørgen Tobias; Kofoed, Klaus F; Møller, Jacob E

    2010-01-01

    and mechanical function with Multi Slice Computed Tomography (MSCT) in patients with ischemic heart disease. Furthermore, the LA and left ventricular (LV) function was evaluated in relation to signs of clinical heart failure. METHODS AND RESULTS: MSCT was performed in 40 patients with sinus rhythm and ischemic......Left atrial (LA) maximal volume contains prognostic information in patients with heart failure and acute myocardial infarction. However, only few studies have investigated the detailed mechanical function of the LA in these patients. We assessed the feasibility of evaluating LA volume...... heart disease. We enrolled 20 patients with reduced LV ejection fraction (LVEF=45%) and 20 with preserved LVEF (>45%). LA volumes, reservoir, channel and pump function were measured. Interobserver variation for LA volume measures was 1.5% (SD: 6.6%). In patients with reduced LVEF, LA volumes were larger...