WorldWideScience

Sample records for volume variation svv

  1. Relationship between Stroke Volume Variation and Blood Transfusion during Liver Transplantation.

    Science.gov (United States)

    Choi, Jae Moon; Lee, Yoon Kyung; Yoo, Hwanhee; Lee, Sukyung; Kim, Hee Yeong; Kim, Young-Kug

    2016-01-01

    Intraoperative blood transfusion increases the risk for perioperative mortality and morbidity in liver transplant recipients. A high stroke volume variation (SVV) method has been proposed to reduce blood loss during living donor hepatectomy. Herein, we investigated whether maintaining high SVV could reduce the need for blood transfusion and also evaluated the effect of the high SVV method on postoperative outcomes in liver transplant recipients. We retrospectively analyzed 332 patients who underwent liver transplantation, divided into control (maintaining blood transfusion requirement and hemodynamic parameters, including SVV, as well as postoperative outcomes, such as incidences of acute kidney injury, durations of postoperative intensive care unit and hospital stay, and rates of 1-year mortality. Mean SVV values were 7.0% ± 1.3% in the control group (n = 288) and 11.2% ± 1.8% in the high SVV group (n = 44). The median numbers of transfused packed red blood cells and fresh frozen plasmas in the high SVV group were significantly lower than those in control group (0 vs. 2 units, P = 0.003; and 0 vs. 3 units, P = 0.033, respectively). No significant between-group differences were observed for postoperative outcomes. Maintaining high SVV can reduce the blood transfusion requirement during liver transplantation without worsening postoperative outcomes. These findings provide insights into improving perioperative management in liver transplant recipients.

  2. Non-invasive measurements of pulse pressure variation and stroke volume variation in anesthetized patients using the Nexfin blood pressure monitor.

    Science.gov (United States)

    Stens, Jurre; Oeben, Jeroen; Van Dusseldorp, Ab A; Boer, Christa

    2016-10-01

    Nexfin beat-to-beat arterial blood pressure monitoring enables continuous assessment of hemodynamic indices like cardiac index (CI), pulse pressure variation (PPV) and stroke volume variation (SVV) in the perioperative setting. In this study we investigated whether Nexfin adequately reflects alterations in these hemodynamic parameters during a provoked fluid shift in anesthetized and mechanically ventilated patients. The study included 54 patients undergoing non-thoracic surgery with positive pressure mechanical ventilation. The provoked fluid shift comprised 15° Trendelenburg positioning, and fluid responsiveness was defined as a concomitant increase in stroke volume (SV) >10 %. Nexfin blood pressure measurements were performed during supine steady state, Trendelenburg and supine repositioning. Hemodynamic parameters included arterial blood pressure (MAP), CI, PPV and SVV. Trendelenburg positioning did not affect MAP or CI, but induced a decrease in PPV and SVV by 3.3 ± 2.8 and 3.4 ± 2.7 %, respectively. PPV and SVV returned back to baseline values after repositioning of the patient to baseline. Bland-Altman analysis of SVV and PPV showed a bias of -0.3 ± 3.0 % with limits of agreement ranging from -5.6 to 6.2 %. The SVV was more superior in predicting fluid responsiveness (AUC 0.728) than the PVV (AUC 0.636), respectively. The median bias between PPV and SVV was different for patients younger [-1.5 % (-3 to 0)] or older [+2 % (0-4.75)] than 55 years (P < 0.001), while there were no gender differences in the bias between PPV and SVV. The Nexfin monitor adequately reflects alterations in PPV and SVV during a provoked fluid shift, but the level of agreement between PPV and SVV was low. The SVV tended to be superior over PPV or Eadyn in predicting fluid responsiveness in our population.

  3. Noninvasive pulse pressure variation and stroke volume variation to predict fluid responsiveness at multiple thresholds : a prospective observational study

    NARCIS (Netherlands)

    Vos, Jaap Jan; Poterman, Marieke; Papineau Salm, Pieternel; Van Amsterdam, Kai; Struys, Michel M. R. F.; Scheeren, Thomas W. L.; Kalmar, Alain F.

    2015-01-01

    Pulse pressure variation (PPV) and stroke volume variation (SVV) are dynamic preload variables that can be measured noninvasively to assess fluid responsiveness (FR) in anesthetized patients with mechanical ventilation. Few studies have examined the effectiveness of predicting FR according to the

  4. Evaluation of stroke volume variation obtained by arterial pulse contour analysis to predict fluid responsiveness intraoperatively.

    Science.gov (United States)

    Lahner, D; Kabon, B; Marschalek, C; Chiari, A; Pestel, G; Kaider, A; Fleischmann, E; Hetz, H

    2009-09-01

    Fluid management guided by oesophageal Doppler monitor has been reported to improve perioperative outcome. Stroke volume variation (SVV) is considered a reliable clinical predictor of fluid responsiveness. Consequently, the aim of the present trial was to evaluate the accuracy of SVV determined by arterial pulse contour (APCO) analysis, using the FloTrac/Vigileo system, to predict fluid responsiveness as measured by the oesophageal Doppler. Patients undergoing major abdominal surgery received intraoperative fluid management guided by oesophageal Doppler monitoring. Fluid boluses of 250 ml each were administered in case of a decrease in corrected flow time (FTc) to 10%. The ability of SVV to predict fluid responsiveness was assessed by calculation of the area under the receiver operating characteristic (ROC) curve. Twenty patients received 67 fluid boluses. Fifty-two of the 67 fluid boluses administered resulted in fluid responsiveness. SVV achieved an area under the ROC curve of 0.512 [confidence interval (CI) 0.32-0.70]. A cut-off point for fluid responsiveness was found for SVV > or =8.5% (sensitivity: 77%; specificity: 43%; positive predictive value: 84%; and negative predictive value: 33%). This prospective, interventional observer-blinded study demonstrates that SVV obtained by APCO, using the FloTrac/Vigileo system, is not a reliable predictor of fluid responsiveness in the setting of major abdominal surgery.

  5. Stroke Volume Variation-Guided Versus Central Venous Pressure-Guided Low Central Venous Pressure With Milrinone During Living Donor Hepatectomy: A Randomized Double-Blinded Clinical Trial.

    Science.gov (United States)

    Lee, Jiwon; Kim, Won Ho; Ryu, Ho-Geol; Lee, Hyung-Chul; Chung, Eun-Jin; Yang, Seong-Mi; Jung, Chul-Woo

    2017-08-01

    We previously demonstrated the usefulness of milrinone for living donor hepatectomy. However, a less-invasive alternative to central venous catheterization and perioperative contributors to good surgical outcomes remain undetermined. The current study evaluated whether the stroke volume variation (SVV)-guided method can substitute central venous catheterization during milrinone-induced profound vasodilation. We randomly assigned 42 living liver donors to receive either SVV guidance or central venous pressure (CVP) guidance to obtain milrinone-induced low CVP. Target SVV of 9% was used as a substitute for CVP of 5 mm Hg. The surgical field grade evaluated by 2 attending surgeons on a 4-point scale was compared between the CVP- and SVV-guided groups (n = 19, total number of scores = 38 per group) as a primary outcome variable. Multivariable analysis was performed to identify independent factors associated with the best surgical field as a post hoc analysis. Surgical field grades, which were either 1 or 2, were not found to be different between the 2 groups via Mann-Whitney U test (P = .358). There was a very weak correlation between SVV and CVP during profound vasodilation such as CVP ≤ 5 mm Hg (R = -0.06; 95% confidence interval, -0.09 to -0.04; P milrinone infusion might be helpful in providing the best surgical field. Milrinone-induced vasodilation resulted in favorable surgical environment regardless of guidance methods of low CVP during living donor hepatectomy. However, SVV was not a useful indicator of low CVP because of very weak correlation between SVV and CVP during profound vasodilation. In addition, factors contributing to the best surgical field such as donor age, proactive fasting, and proper dosing of milrinone need to be investigated further, ideally through prospective studies.

  6. Extravascular Lung Water Does Not Increase in Hypovolemic Patients after a Fluid-Loading Protocol Guided by the Stroke Volume Variation

    Directory of Open Access Journals (Sweden)

    Carlos Ferrando

    2012-01-01

    Full Text Available Introduction. Circulatory failure secondary to hypovolemia is a common situation in critical care patients. Volume replacement is the first option for the treatment of hypovolemia. A possible complication of volume loading is pulmonary edema, quantified at the bedside by the measurement of extravascular lung water index (ELWI. ELWI predicts progression to acute lung injury (ALI in patients with risk factors for developing it. The aim of this study was to assess whether fluid loading guided by the stroke volume variation (SVV, in patients presumed to be hypovolemic, increased ELWI or not. Methods. Prospective study of 17 consecutive postoperative, fully mechanically ventilated patients diagnosed with circulatory failure secondary to presumed hypovolemia were included. Cardiac index (CI, ELWI, SVV, and global end-diastolic volume index (GEDI were determined using the transpulmonary thermodilution technique during the first 12 hours after fluid loading. Volume replacement was done with a strict hemodynamic protocol. Results. Fluid loading produced a significant increase in CI and a decrease in SVV. ELWI did not increase. No correlation was found between the amount of fluids administered and the change in ELWI. Conclusion. Fluid loading guided by SVV in hypovolemic and fully mechanically ventilated patients in sinus rhythm does not increase ELWI.

  7. Qualification of flow barriers in salt formations; SVV 2. Qualifizierung von Stroemungsbarrieren in Salzformationen

    Energy Technology Data Exchange (ETDEWEB)

    Herbert, Horst-Juergen; Hertes, Uwe; Meyer, Lothar; Hellwald, Karsten; Dittrich, Juergen

    2011-09-15

    The GRS report covers the technical concept of flow barriers in salt formations of self-healing salt backfilling (SVV) for the plugging of boreholes in underground radioactive waste repositories. Laboratory measurements in large dimensions and in-situ experiments were performed in the salt formations carnallitite (Asse mine) and tachhydrite (mine Teutschenthal) and showed the technical feasibility of the concept. The report includes the following chapters following the introduction: State-of-the-art of science and technology before the beginning of the project. Aims of the project. SVV plugging principle. Raw material and salt solutions. Laboratory measurements. Experiments concerning the efficiency assessment of SVV plugging elements. Results on SVV sealing properties - laboratory experiments. Results on SVV sealing properties - in-situ experiments. Results concerning the geomechanical properties. SVV-long-term behavior. Technical requirements to the practicability of SVV plugging elements.

  8. Goal-Directed Fluid Therapy Based on Stroke Volume Variation in Patients Undergoing Major Spine Surgery in the Prone Position: A Cohort Study.

    Science.gov (United States)

    Bacchin, Maria Renata; Ceria, Chiara Marta; Giannone, Sandra; Ghisi, Daniela; Stagni, Gaetano; Greggi, Tiziana; Bonarelli, Stefano

    2016-09-15

    A retrospective observational study. The aim of this study was to test whether a goal-directed fluid therapy (GDFT) protocol, based on stroke volume variation (SVV), applied in major spine surgery performed in the prone position, would be effective in reducing peri-operative red blood cells transfusions. Recent literature shows that optimizing perioperative fluid therapy is associated with lower complication rates and faster recovery. Data from 23 patients who underwent posterior spine arthrodesis surgery and whose intraoperative fluid administration were managed with the GDFT protocol were retrospectively collected and compared with data from 23 matched controls who underwent the same surgical procedure in the same timeframe, and who received a liberal intraoperative fluid therapy. Patients in the GDFT group received less units of transfused red blood cells (primary endpoint) in the intra (0 vs. 2.0, P = 0.0 4) and postoperative period (2.0 vs. 4.0, P = 0.003). They also received a lower amount of intraoperative crystalloids, had fewer blood losses, and lower intraoperative peak lactate. In the postoperative period, patients in the GDFT group had fewer pulmonary complications and blood losses from surgical drains, needed less blood product transfusions, had a shorter intensive care unit stay, and a faster return of bowel function. We found no difference in the total length of stay among the two groups. Our study shows that application of a GDFT based on SVV in major spine surgery is feasible and can lead to reduced blood losses and transfusions, better postoperative respiratory performance, shorter ICU stay, and faster return of bowel function. 3.

  9. Variation of gross tumor volume and clinical target volume definition for lung cancer

    International Nuclear Information System (INIS)

    Liang Jun; Li Minghui; Chen Dongdu

    2011-01-01

    Objective: To study the variation of gross tumor volume (GTV) and clinical target volume (CTV) definition for lung cancer between different doctors. Methods: Ten lung cancer patients with PET-CT simulation were selected from January 2008 to December 2009.GTV and CTV of these patients were defined by four professors or associate professors of radiotherapy independently. Results: The mean ratios of largest to smallest GTV and CTV were 1.66 and 1.65, respectively. The mean coefficients of variation for GTV and CTV were 0.20 and 0.17, respectively. System errors of CTV definition in three dimension were less than 5 mm, which was the largest in inferior and superior (0.48 cm, 0.37 cm, 0.32 cm; F=0.40, 0.60, 0.15, P=0.755, 0.618, 0.928). Conclusions: The variation of GTV and CTV definition for lung cancer between different doctors exist. The mean ratios of largest to smallest GTV and CTV were less than 1.7. The variation was in hilar and mediastinum lymphanode regions. System error of CTV definition was the largest (<5 mm) in cranio-caudal direction. (authors)

  10. Variation in Annual Volume at a University Hospital Does Not Predict Mortality for Pancreatic Resections

    Directory of Open Access Journals (Sweden)

    Rita A. Mukhtar

    2008-01-01

    Full Text Available Annual volume of pancreatic resections has been shown to affect mortality rates, prompting recommendations to regionalize these procedures to high-volume hospitals. Implementation has been difficult, given the paucity of high-volume centers and the logistical hardships facing patients. Some studies have shown that low-volume hospitals achieve good outcomes as well, suggesting that other factors are involved. We sought to determine whether variations in annual volume affected patient outcomes in 511 patients who underwent pancreatic resections at the University of California, San Francisco between 1990 and 2005. We compared postoperative mortality and complication rates between low, medium, or high volume years, designated by the number of resections performed, adjusting for patient characteristics. Postoperative mortality rates did not differ between high volume years and medium/low volume years. As annual hospital volume of pancreatic resections may not predict outcome, identification of actual predictive factors may allow low-volume centers to achieve excellent outcomes.

  11. A Volume Constrained Variational Problem with Lower-Order Terms

    International Nuclear Information System (INIS)

    Morini, M.; Rieger, M.O.

    2003-01-01

    We study a one-dimensional variational problem with two or more level set constraints. The existence of global and local minimizers turns out to be dependent on the regularity of the energy density. A complete characterization of local minimizers and the underlying energy landscape is provided. The Γ -limit when the phases exhaust the whole domain is computed

  12. 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.

    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

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

    International Nuclear Information System (INIS)

    Nijkamp, Jasper; Haas-Kock, Danielle F.M. de; Beukema, Jannet C.; Neelis, Karen J.; Woutersen, Dankert; Ceha, Heleen; Rozema, Tom; Slot, Annerie; Vos-Westerman, Hanneke; Intven, Martijn; Spruit, Patty H.; Linden, Yvette van der; Geijsen, Debby; Verschueren, Karijn; Herk, Marcel B. van; 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 according to local guidelines (phase 1). After observer variation analysis a workshop was organized to establish delineation guidelines and a digital atlas, with which the same observers re-delineated the dataset (phase 2). Variation in volume, most caudal and cranial slice and local surface distance variation were analyzed. Results: The average delineated CTV volume decreased from 620 to 460 cc (p < 0.001) in phase 2. Variation in the caudal CTV border was reduced significantly from 1.8 to 1.2 cm SD (p = 0.01), while it remained 0.7 cm SD for the cranial border. The local surface distance variation (cm SD) reduced from 1.02 to 0.74 for anterior, 0.63 to 0.54 for lateral, 0.33 to 0.25 for posterior and 1.22 to 0.46 for the sphincter region, respectively. Conclusions: The large variation in target volume delineation could significantly be reduced by use of consensus guidelines and a digital delineation atlas. Despite the significant reduction there is still a need for further improvement.

  14. 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.

  15. Cardiac variation of inferior vena cava: new concept in the evaluation of intravascular blood volume.

    Science.gov (United States)

    Nakamura, Kensuke; Tomida, Makoto; Ando, Takehiro; Sen, Kon; Inokuchi, Ryota; Kobayashi, Etsuko; Nakajima, Susumu; Sakuma, Ichiro; Yahagi, Naoki

    2013-07-01

    Evaluation of the intravascular blood volume is an important assessment in emergency and critical care medicine. Measurement of the inferior vena cava (IVC) respiratory variation by ultrasound echography is useful, but it entails subjective problems. We have hypothesized that IVC cardiac variation is also correlated with intravascular blood volume and analyzed it automatically using computer software of two kinds, later comparing the results. Snakes, software to track boundaries by curve line continuity, and template matching software were incorporated into a computer with an ultrasound machine to track the short-axis view of IVC automatically and analyze it with approximation by ellipse. Eight healthy volunteers with temporary mild hypovolemia underwent echography before and after passive leg raising and while wearing medical anti-shock trousers. IVC cardiac variation was visually decreased by both leg raising and medical anti-shock trousers. The collapse index (maximum - minimum/maximum) of area during three cardiac beats was decreased showing a good relationship to fluid load simulations; 0.24 ± 0.03 at baseline versus 0.11 ± 0.01 with leg raising and 0.12 ± 0.01 with medical anti-shock trousers. In conclusion, IVC cardiac variation has the potential to provide an evaluation of water volume. It presents some advantages in mechanical analysis over respiratory variation. At the very least, we need to exercise some caution with cardiac variation when evaluating respiratory variation.

  16. 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. © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  17. 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.

  18. 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

    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 card...

  19. Ultrasonographic Measures of Volume Responsiveness

    Science.gov (United States)

    2017-02-01

    specific single value cut -offs. In distinction, most point -of-care US data report very specific values (rv IVC of 18 and 41% or 13% IJ change) for...variation, focused rapid echocardiographic evaluation, FREE, point -of-care ultrasound, POCUS, cardiac ultrasound 16. SECURITY CLASSIFICATION OF: 17...not be interpreted in 3, for a final study group of 199. After the pilot analyses, passive leg raise SVV was abandoned, as it could not be reliably

  20. 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....

  1. Menstrual variation of breast volume and T2 relaxation times in cyclical mastalgia

    International Nuclear Information System (INIS)

    Hussain, Zainab; Brooks, Jonathan; Percy, Dave

    2008-01-01

    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 1 H Magnetic Resonance Spectroscopy (MRS) to measure T 2 relaxation times which are known to increase with increasing tissue water content. We hypothesised that an increase in breast volume will elevate T 2 relaxation due to the presence of an increased water content within the breast. T 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 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 2 relaxation times of the water and fat in a voxel of breast tissue were obtained using 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 2 of fat or water did not depend on stage of cycle. T-tests demonstrated no significant differences in T 2 of water or fat between patient and control groups. The average T 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 2 were not significantly different from normal menstrual variations

  2. Effects of DARPP-32 Genetic Variation on Prefrontal Cortex Volume and Episodic Memory Performance

    Directory of Open Access Journals (Sweden)

    Ninni Persson

    2017-05-01

    Full Text Available Despite evidence of a fundamental role of DARPP-32 in integrating dopamine and glutamate signaling, studies examining gene coding for DARPP-32 in relation to neural and behavioral correlates in humans are scarce. Post mortem findings suggest genotype specific expressions of DARPP-32 in the dorsal frontal lobes. Therefore, we investigated the effects of genomic variation in DARPP-32 coding on frontal lobe volumes and episodic memory. Volumetric data from the dorsolateral (DLPFC, and visual cortices (VC were obtained from 61 younger and older adults (♀54%. The major homozygote G, T, or A genotypes in single nucleotide polymorphisms (SNPs: rs879606; rs907094; rs3764352, the two latter in complete linkage disequilibrium, at the DARPP-32 regulating PPP1R1B gene, influenced frontal gray matter volume and episodic memory (EM. Homozygous carriers of allelic variants with lower DARPP-32 expression had an overall larger prefrontal volume in addition to greater EM recall accuracy after accounting for the influence of age. The SNPs did not influence VC volume. The genetic effects on DLPFC were greater in young adults and selective to this group for EM. Our findings suggest that genomic variation maps onto individual differences in frontal brain volumes and cognitive functions. Larger DLPFC volumes were also related to better EM performance, suggesting that gene-related differences in frontal gray matter may contribute to individual differences in EM. These results need further replication from experimental and longitudinal reports to determine directions of causality.

  3. 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.

  4. 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

    : The correlation between the relative bladder volume (RBV, defined as repeat scan volume/planning scan volume) and the margins required to account for internal motion was first studied using a series of 20 bladder cancer patients with weekly repeat CT scanning during treatment. Both conformal RT (CRT) and IGRT......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...... these patients were given fluid intake restrictions on alternating weeks during treatment. RESULTS: IGRT gave the strongest correlation between the RBV and margin size (R(2)=0.75; p10mm were required in only 1% of the situations when the RBV1, whereas isotropic margins >10...

  5. 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

  6. Variation in orbitofrontal cortex volume: relation to sex, emotion regulation and affect.

    Science.gov (United States)

    Welborn, B Locke; Papademetris, Xenophon; Reis, Deidre L; Rajeevan, Nallakkandi; Bloise, Suzanne M; Gray, Jeremy R

    2009-12-01

    Sex differences in brain structure have been examined extensively but are not completely understood, especially in relation to possible functional correlates. Our two aims in this study were to investigate sex differences in brain structure, and to investigate a possible relation between orbitofrontal cortex subregions and affective individual differences. We used tensor-based morphometry to estimate local brain volume from MPRAGE images in 117 healthy right-handed adults (58 female), age 18-40 years. We entered estimates of local brain volume as the dependent variable in a GLM, controlling for age, intelligence and whole-brain volume. Men had larger left planum temporale. Women had larger ventromedial prefrontal cortex (vmPFC), right lateral orbitofrontal (rlOFC), cerebellum, and bilateral basal ganglia and nearby white matter. vmPFC but not rlOFC volume covaried with self-reported emotion regulation strategies (reappraisal, suppression), expressivity of positive emotions (but not of negative), strength of emotional impulses, and cognitive but not somatic anxiety. vmPFC volume statistically mediated sex differences in emotion suppression. The results confirm prior reports of sex differences in orbitofrontal cortex structure, and are the first to show that normal variation in vmPFC volume is systematically related to emotion regulation and affective individual differences.

  7. Variation of clinical target volume definition in three-dimensional conformal radiation therapy for prostate cancer

    International Nuclear Information System (INIS)

    Valicenti, Richard K.; Sweet, John W.; Hauck, Walter W.; Hudes, Richard S.; Lee, Tony; Dicker, Adam P.; Waterman, Frank M.; Anne, Pramila R.; Corn, Benjamin W.; Galvin, James M.

    1999-01-01

    Purpose: Currently, three-dimensional conformal radiation therapy (3D-CRT) planning relies on the interpretation of computed tomography (CT) axial images for defining the clinical target volume (CTV). This study investigates the variation among multiple observers to define the CTV used in 3D-CRT for prostate cancer. Methods and Materials: Seven observers independently delineated the CTVs (prostate ± seminal vesicles [SV]) from the CT simulation data of 10 prostate cancer patients undergoing 3D-CRT. Six patients underwent CT simulation without the use of contrast material and serve as a control group. The other 4 had urethral and bladder opacification with contrast medium. To determine interobserver variation, we evaluated the derived volume, the maximum dimensions, and the isocenter for each examination of CTV. We assessed the reliability in the CTVs among the observers by correlating the variation for each class of measurements. This was estimated by intraclass correlation coefficient (ICC), with 1.00 defining absolute correlation. Results: For the prostate volumes, the ICC was 0.80 (95% confidence interval [CI]: 0.56-0.96). This changed to 0.92 (95% CI: 0.75-0.99) with the use of contrast material. Similarly, the maximal prostatic dimensions were reliable and improved. There was poor agreement in defining the SV. For this structure, the ICC never exceeded 0.28. The reliability of the isocenter was excellent, with the ICC exceeding 0.83 and 0.90 for the prostate ± SV, respectively. Conclusions: In 3D-CRT for prostate cancer, there was excellent agreement among multiple observers to define the prostate target volume but poor agreement to define the SV. The use of urethral and bladder contrast improved the reliability of localizing the prostate. For all CTVs, the isocenter was very reliable and should be used to compare the variation in 3D dosimetry among multiple observers

  8. 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.

  9. Significance of breast boost volume changes during radiotherapy in relation to current clinical interobserver variations

    International Nuclear Information System (INIS)

    Hurkmans, Coen; Admiraal, Marjan; Sangen, Maurice van der; Dijkmans, Ingrid

    2009-01-01

    Background and purpose: Nowadays, many departments introduce CT images for breast irradiation techniques, aiming to obtain a better accuracy in the definition of the relevant target volumes. However, the definition of the breast boost volume based on CT images requires further investigation, because it may not only vary between observers, but it may also change during the course of treatment. This study aims to quantify the variability of the CT based visible boost volume (VBV) during the course of treatment in relation to the variability between observers. Materials and methods: Ten patients with stage T1-2 invasive breast cancer treated with breast conservative surgery and post surgical radiotherapy were included in this study. In addition to the regular planning CT which is obtained several days prior to radiotherapy, three additional CT scans were acquired 3, 5 and 7 weeks after the planning CT scan. Four radiation oncologists delineated the VBV in all scans. Conformity of the delineations was analysed both between observers, and between scans taken at different periods of the radiotherapy treatment. Results: The VBV averaged over all patients decreased during the course of the treatment from an initial 40 cm 3 to 28 cm 3 , 27 cm 3 and 25 cm 3 after 3, 5 and 7 weeks, respectively. Assuming the VBV to be spherical, this corresponds to a reduction in diameter of 5-6 mm. More detailed analysis revealed that this reduction was more pronounced when radiotherapy started within 30 days after surgery. These boost volume changes over time were found to be significant (p = 0.02) even in the presence of interobserver variations. Moreover, the conformity index (CI) for the volume changes was of the same magnitude as the conformity index for the interobserver variation (0.25 and 0.31, respectively). Conclusions: Breast boost volume variations during a course of radiotherapy are significant in relation to current clinical interobserver variations. This is an important

  10. Genomic regulation of natural variation in cortical and noncortical brain volume

    Directory of Open Access Journals (Sweden)

    Laughlin Rick E

    2006-02-01

    Full Text Available Abstract Background The relative growth of the neocortex parallels the emergence of complex cognitive functions across species. To determine the regions of the mammalian genome responsible for natural variations in cortical volume, we conducted a complex trait analysis using 34 strains of recombinant inbred (Rl strains of mice (BXD, as well as their two parental strains (C57BL/6J and DBA/2J. We measured both neocortical volume and total brain volume in 155 coronally sectioned mouse brains that were Nissl stained and embedded in celloidin. After correction for shrinkage, the measured cortical and noncortical brain volumes were entered into a multiple regression analysis, which removed the effects of body size and age from the measurements. Marker regression and interval mapping were computed using WebQTL. Results An ANOVA revealed that more than half of the variance of these regressed phenotypes is genetically determined. We then identified the regions of the genome regulating this heritability. We located genomic regions in which a linkage disequilibrium was present using WebQTL as both a mapping engine and genomic database. For neocortex, we found a genome-wide significant quantitative trait locus (QTL on chromosome 11 (marker D11Mit19, as well as a suggestive QTL on chromosome 16 (marker D16Mit100. In contrast, for noncortex the effect of chromosome 11 was markedly reduced, and a significant QTL appeared on chromosome 19 (D19Mit22. Conclusion This classic pattern of double dissociation argues strongly for different genetic factors regulating relative cortical size, as opposed to brain volume more generally. It is likely, however, that the effects of proximal chromosome 11 extend beyond the neocortex strictly defined. An analysis of single nucleotide polymorphisms in these regions indicated that ciliary neurotrophic factor (Cntf is quite possibly the gene underlying the noncortical QTL. Evidence for a candidate gene modulating neocortical

  11. Tumor response parameters for head and neck cancer derived from tumor-volume variation during radiation therapy

    International Nuclear Information System (INIS)

    Chvetsov, Alexei V.

    2013-01-01

    Purpose: The main goal of this paper is to reconstruct a distribution of cell survival fractions from tumor-volume variation for a heterogeneous group of head and neck cancer patients and compare this distribution to the data from predictive assays. Methods: To characterize the tumor-volume variation during radiation therapy treatment, the authors use a two-level tumor-volume model of cell population that separates the entire tumor cell population into two subpopulations of viable cells and lethally damaged cells. This parameterized radiobiological model is integrated with a least squares objective function and a simulated annealing optimization algorithm to describe time-dependent tumor-volume variation rates in individual patients. Several constraints have been used in the optimization problem because tumor-volume variation during radiotherapy is described by a sum of exponentials; therefore, the problem of accurately fitting a model to measured data is ill-posed. The model was applied to measured tumor-volume variation curves from a clinical study on tumor-volume variation during radiotherapy for 14 head and neck cancer patients in which an integrated CT/linear particle accelerator (LINAC) system was used for tumor-volume measurements. Results: The two-level cell population tumor-volume modeling is capable of describing tumor-volume variation throughout the entire treatment for 11 of the 14 patients. For three patients, the tumor-volume variation was described only during the initial part of treatment, a fact that may be related to the neglected hypoxia in the two-level approximation. The predicted probability density distribution for the survival fractions agrees with the data obtained using in vitro studies with predictive assays. The mean value 0.35 of survival fraction obtained in this study is larger than the value 0.32 from in vitro studies, which could be expected because of greater repair in vivo. The mean half-life obtained in this study for the head

  12. 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.

  13. Target volume delineation in external beam partial breast irradiation: Less inter-observer variation with preoperative- compared to postoperative delineation

    International Nuclear Information System (INIS)

    Leij, Femke van der; Elkhuizen, Paula H.M.; Janssen, Tomas M.; Poortmans, Philip; Sangen, Maurice van der; Scholten, Astrid N.; Vliet-Vroegindeweij, Corine van; Boersma, Liesbeth J.

    2014-01-01

    The challenge of adequate target volume definition in external beam partial breast irradiation (PBI) could be overcome with preoperative irradiation, due to less inter-observer variation. We compared the target volume delineation for external beam PBI on preoperative versus postoperative CT scans of twenty-four breast cancer patients

  14. Target volume delineation in external beam partial breast irradiation: less inter-observer variation with preoperative- compared to postoperative delineation

    NARCIS (Netherlands)

    Leij, F. van der; Elkhuizen, P.H.M.; Janssen, T.M.; Poortmans, P.M.P.; Sangen, M. van der; Scholten, A.N.; Vliet-Vroegindeweij, C. van; Boersma, L.J.

    2014-01-01

    The challenge of adequate target volume definition in external beam partial breast irradiation (PBI) could be overcome with preoperative irradiation, due to less inter-observer variation. We compared the target volume delineation for external beam PBI on preoperative versus postoperative CT scans of

  15. 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.

  16. Effect of fluid loading on left ventricular volume and stroke volume variability in patients with end-stage renal disease: a pilot study

    Science.gov (United States)

    Kanda, Hirotsugu; Hirasaki, Yuji; Iida, Takafumi; Kanao-Kanda, Megumi; Toyama, Yuki; Kunisawa, Takayuki; Iwasaki, Hiroshi

    2015-01-01

    Purpose The aim of this study was to investigate fluid loading-induced changes in left ventricular end-diastolic volume (LVEDV) and stroke volume variability (SVV) in patients with end-stage renal disease (ESRD) using real-time three-dimensional transesophageal echocardiography and the Vigileo-FloTrac system. Patients and methods After obtaining ethics committee approval and informed consent, 28 patients undergoing peripheral vascular procedures were studied. Fourteen patients with ESRD on hemodialysis (HD) were assigned to the HD group and 14 patients without ESRD were assigned to the control group. Institutional standardized general anesthesia was provided in both groups. SVV was measured using the Vigileo-FloTrac system. Simultaneously, a full-volume three-dimensional transesophageal echocardiography dataset was acquired to measure LVEDV, left ventricular end-systolic volume, and left ventricular ejection fraction. Measurements were obtained before and after loading 500 mL hydroxyethyl starch over 30 minutes in both groups. Results In the control group, intravenous colloid infusion was associated with a significant decrease in SVV (13.8%±2.6% to 6.5%±2.6%, P<0.001) and a significant increase in LVEDV (83.6±23.4 mL to 96.1±28.8 mL, P<0.001). While SVV significantly decreased after infusion in the HD group (16.2%±6.0% to 6.2%±2.8%, P<0.001), there was no significant change in LVEDV. Conclusion Our preliminary data suggest that fluid responsiveness can be assessed not by LVEDV but also by SVV due to underlying cardiovascular pathophysiology in patients with ESRD. PMID:26527879

  17. Assessment of the accuracy of ABC/2 variations in traumatic epidural hematoma volume estimation: a retrospective study

    Directory of Open Access Journals (Sweden)

    Pengfei Yan

    2016-04-01

    Full Text Available Background. The traumatic epidural hematoma (tEDH volume is often used to assist in tEDH treatment planning and outcome prediction. ABC/2 is a well-accepted volume estimation method that can be used for tEDH volume estimation. Previous studies have proposed different variations of ABC/2; however, it is unclear which variation will provide a higher accuracy. Given the promising clinical contribution of accurate tEDH volume estimations, we sought to assess the accuracy of several ABC/2 variations in tEDH volume estimation. Methods. The study group comprised 53 patients with tEDH who had undergone non-contrast head computed tomography scans. For each patient, the tEDH volume was automatically estimated by eight ABC/2 variations (four traditional and four newly derived with an in-house program, and results were compared to those from manual planimetry. Linear regression, the closest value, percentage deviation, and Bland-Altman plot were adopted to comprehensively assess accuracy. Results. Among all ABC/2 variations assessed, the traditional variations y = 0.5 × A1B1C1 (or A2B2C1 and the newly derived variations y = 0.65 × A1B1C1 (or A2B2C1 achieved higher accuracy than the other variations. No significant differences were observed between the estimated volume values generated by these variations and those of planimetry (p > 0.05. Comparatively, the former performed better than the latter in general, with smaller mean percentage deviations (7.28 ± 5.90% and 6.42 ± 5.74% versus 19.12 ± 6.33% and 21.28 ± 6.80%, respectively and more values closest to planimetry (18/53 and 18/53 versus 2/53 and 0/53, respectively. Besides, deviations of most cases in the former fell within the range of 20% (90.57% and 96.23, respectively. Discussion. In the current study, we adopted an automatic approach to assess the accuracy of several ABC/2 variations for tEDH volume estimation. Our initial results showed that the variations y = 0.5 × A1B1C1 (or A2B2C1

  18. Dosimetric impact of the variation of the prostate volume and shape between pretreatment planning and treatment procedure

    International Nuclear Information System (INIS)

    Beaulieu, Luc; Aubin, Sylviane; Taschereau, Richard; Pouliot, Jean; Vigneault, Eric

    2002-01-01

    Purpose: The goal of this study is to evaluate the dosimetric impact on a pretreatment planning of prostatic volume and shape variations occurring between the moment of the volume study (preplanning) and just before a transperineal permanent seed implant procedure. Such variations could be an obvious source of misplacement of the seeds relative to the prostate gland and organs at risk. Other sources of dosimetric uncertainties, such as misplacement due to the procedure itself or edema, are eliminated by looking at these variations before the implant procedure. Methods and Materials: For 35 clinical cases, prostate contours were taken at preplanning time as well as in the operating room (OR) minutes before the procedure. Comparison of shape and volume between the two sets was made. The impact on V100 was evaluated by placing the seeds in their planned positions in the new volume (clinical situation) and also by performing a new plan with the second set of contours to simulate an intraoperative approach. Results: The volume taken in the OR remained unchanged compared to the pretreatment planning volume in only 37% of the cases. While on average the dose coverage loss from pretreatment planning due to a combination of variations of volume and shape was small at 5.7%, a V100 degradation of up to 20.9% was observed in extreme cases. Even in cases in which no changes in volume were observed, changes in shape occurred and strongly affected implant dosimetry. Conclusions: Variations of volume and shape between pretreatment planning and the implant procedure can have a strong impact on the dosimetry if the planning and the implant procedure are not performed on the same day. This is an argument in favor of performing implant dosimetry in the OR

  19. Variations of radon volume activities in soil and indoor air and their correlation

    International Nuclear Information System (INIS)

    Mojzes, A.

    1998-01-01

    Some manual measurements of volume activity of 222 Rn ai soil air and in indoor air of building together with parallel measurements of some meteorological parameters (temperature, humidity and pressure) of both atmospheric and indoor air were carried out. The measurements were performed in the building of Faculty and in its subsoil which consists of slope loams of the base of SW slopes of granitic Male Karpaty Mountains in the area of confluence of the Vidrica Creek with an arm of the Donau river. The monitoring measurements lasted form more than one and a half year, from January 1977 to August 1998, with the frequency of approximately once a week in each object. The soil air was taken from a permanently set up and sealed pipe from the depth of 0.8 m which was placed approximately 10 m from the building at the open air. All measurements of 222 Rn volume activities were performed with a portable fully automatic scintillation detector based on exchangeable Lucas cells. There were also performed the parallel measurements of some meteorological parameters (temperature, humidity and pressure) of air in each object. The geological basement of building is a source of indoor radon. The volume activities of soil 222 Rn range from about 2 kBq/m 3 to about 20 kBq/m 3 with the average of 9.26 kBq/m 3 and the standard deviation of 2.95 kBq/m 3 . The volume activities of indoor air in basement room were form 150 Bq/m 3 to 225 Bq/m 3 and on the third story they were from 125 Bq/m 3 to 175 Bq/m 3 (approximately). The results of monitoring measurements during 20 months period point out the intensity of interaction of geological substrate with building interior through the values of the volume activity of 222 Rn. Therefore a method of building foundation is one of the most important factors which determines the quantity of radon in indoor air. In the light of quality, the fluctuation of radon presence in the bottom part of the buildings is strongly determined by the variations of

  20. SU-E-T-429: Uncertainties of Cell Surviving Fractions Derived From Tumor-Volume Variation Curves

    International Nuclear Information System (INIS)

    Chvetsov, A

    2014-01-01

    Purpose: To evaluate uncertainties of cell surviving fraction reconstructed from tumor-volume variation curves during radiation therapy using sensitivity analysis based on linear perturbation theory. Methods: The time dependent tumor-volume functions V(t) have been calculated using a twolevel cell population model which is based on the separation of entire tumor cell population in two subpopulations: oxygenated viable and lethally damaged cells. The sensitivity function is defined as S(t)=[δV(t)/V(t)]/[δx/x] where δV(t)/V(t) is the time dependent relative variation of the volume V(t) and δx/x is the relative variation of the radiobiological parameter x. The sensitivity analysis was performed using direct perturbation method where the radiobiological parameter x was changed by a certain error and the tumor-volume was recalculated to evaluate the corresponding tumor-volume variation. Tumor volume variation curves and sensitivity functions have been computed for different values of cell surviving fractions from the practically important interval S 2 =0.1-0.7 using the two-level cell population model. Results: The sensitivity functions of tumor-volume to cell surviving fractions achieved a relatively large value of 2.7 for S 2 =0.7 and then approached zero as S 2 is approaching zero Assuming a systematic error of 3-4% we obtain that the relative error in S 2 is less that 20% in the range S2=0.4-0.7. This Resultis important because the large values of S 2 are associated with poor treatment outcome should be measured with relatively small uncertainties. For the very small values of S2<0.3, the relative error can be larger than 20%; however, the absolute error does not increase significantly. Conclusion: Tumor-volume curves measured during radiotherapy can be used for evaluation of cell surviving fractions usually observed in radiation therapy with conventional fractionation

  1. 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.

  2. PPARα L162V underlies variation in serum triglycerides and subcutaneous fat volume in young males

    Directory of Open Access Journals (Sweden)

    Clarkson Priscilla M

    2007-08-01

    Full Text Available Abstract Background Of the five sub-phenotypes defining metabolic syndrome, all are known to have strong genetic components (typically 50–80% of population variation. Studies defining genetic predispositions have typically focused on older populations with metabolic syndrome and/or type 2 diabetes. We hypothesized that the study of younger populations would mitigate many confounding variables, and allow us to better define genetic predisposition loci for metabolic syndrome. Methods We studied 610 young adult volunteers (average age 24 yrs for metabolic syndrome markers, and volumetric MRI of upper arm muscle, bone, and fat pre- and post-unilateral resistance training. Results We found the PPARα L162V polymorphism to be a strong determinant of serum triglyceride levels in young White males, where carriers of the V allele showed 78% increase in triglycerides relative to L homozygotes (LL = 116 ± 11 mg/dL, LV = 208 ± 30 mg/dL; p = 0.004. Men with the V allele showed lower HDL (LL = 42 ± 1 mg/dL, LV = 34 ± 2 mg/dL; p = 0.001, but women did not. Subcutaneous fat volume was higher in males carrying the V allele, however, exercise training increased fat volume of the untrained arm in V carriers, while LL genotypes significantly decreased in fat volume (LL = -1,707 ± 21 mm3, LV = 17,617 ± 58 mm3 ; p = 0.002, indicating a systemic effect of the V allele on adiposity after unilateral training. Our study suggests that the primary effect of PPARα L162V is on serum triglycerides, with downstream effects on adiposity and response to training. Conclusion Our results on association of PPARα and triglycerides in males showed a much larger effect of the V allele than previously reported in older and less healthy populations. Specifically, we showed the V allele to increase triglycerides by 78% (p = 0.004, and this single polymorphism accounted for 3.8% of all variation in serum triglycerides in males (p = 0.0037.

  3. Assessment of interpatient heterogeneity in tumor radiosensitivity for nonsmall cell lung cancer using tumor-volume variation data

    Energy Technology Data Exchange (ETDEWEB)

    Chvetsov, Alexei V., E-mail: chvetsov2@gmail.com; Schwartz, Jeffrey L.; Mayr, Nina [Department of Radiation Oncology, University of Washington, 1959 NE Pacific Street, Seattle, Washington 98195-6043 (United States); Yartsev, Slav [London Regional Cancer Program, London Health Sciences Centre, 790 Commissioners Road East, London, Ontario 46A 4L6 (Canada)

    2014-06-15

    Purpose: In our previous work, the authors showed that a distribution of cell surviving fractionsS{sub 2} in a heterogeneous group of patients could be derived from tumor-volume variation curves during radiotherapy for head and neck cancer. In this research study, the authors show that this algorithm can be applied to other tumors, specifically in nonsmall cell lung cancer. This new application includes larger patient volumes and includes comparison of data sets obtained at independent institutions. Methods: Our analysis was based on two data sets of tumor-volume variation curves for heterogeneous groups of 17 patients treated for nonsmall cell lung cancer with conventional dose fractionation. The data sets were obtained previously at two independent institutions by using megavoltage computed tomography. Statistical distributions of cell surviving fractionsS{sub 2} and clearance half-lives of lethally damaged cells T{sub 1/2} have been reconstructed in each patient group by using a version of the two-level cell population model of tumor response and a simulated annealing algorithm. The reconstructed statistical distributions of the cell surviving fractions have been compared to the distributions measured using predictive assays in vitro. Results: Nonsmall cell lung cancer presents certain difficulties for modeling surviving fractions using tumor-volume variation curves because of relatively large fractional hypoxic volume, low gradient of tumor-volume response, and possible uncertainties due to breathing motion. Despite these difficulties, cell surviving fractionsS{sub 2} for nonsmall cell lung cancer derived from tumor-volume variation measured at different institutions have similar probability density functions (PDFs) with mean values of 0.30 and 0.43 and standard deviations of 0.13 and 0.18, respectively. The PDFs for cell surviving fractions S{sub 2} reconstructed from tumor volume variation agree with the PDF measured in vitro. Conclusions: The data obtained

  4. Amygdala Volume in Offspring from Multiplex for Alcohol Dependence Families: The Moderating Influence of Childhood Environment and 5-HTTLPR Variation.

    Science.gov (United States)

    Hill, Shirley Y; Wang, Shuhui; Carter, Howard; McDermott, Michael D; Zezza, Nicholas; Stiffler, Scott

    2013-12-12

    The increased susceptibility for developing alcohol dependence seen in offspring from families with alcohol dependence may be related to structural and functional differences in brain circuits that influence emotional processing. Early childhood environment, genetic variation in the serotonin transporter-linked polymorphic region (5-HTTLPR) of the SLCA4 gene and allelic variation in the Brain Derived Neurotrophic Factor (BDNF) gene have each been reported to be related to volumetric differences in the temporal lobe especially the amygdala. Magnetic resonance imaging was used to obtain amygdala volumes for 129 adolescent/young adult individuals who were either High-Risk (HR) offspring from families with multiple cases of alcohol dependence (N=71) or Low-Risk (LR) controls (N=58). Childhood family environment was measured prospectively using age-appropriate versions of the Family Environment Scale during a longitudinal follow-up study. The subjects were genotyped for Brain-Derived Neurotrophic Factor (BDNF) Val66Met and the serotonin transporter polymorphism (5-HTTLPR). Two family environment scale scores (Cohesion and Conflict), genotypic variation, and their interaction were tested for their association with amygdala volumes. Personal and prenatal exposure to alcohol and drugs were considered in statistical analyses in order to more accurately determine the effects of familial risk group differences. Amygdala volume was reduced in offspring from families with multiple alcohol dependent members in comparison to offspring from control families. High-Risk offspring who were carriers of the S variant of the 5-HTTLPR polymorphism had reduced amygdala volume in comparison to those with an LL genotype. Larger amygdala volume was associated with greater family cohesion but only in Low-Risk control offspring. Familial risk for alcohol dependence is an important predictor of amygdala volume even when removing cases with significant personal exposure and covarying for

  5. Variation in Results of Volume Measurements of Stumps of Lower-Limb Amputees : A Comparison of 4 Methods

    NARCIS (Netherlands)

    de Boer-Wilzing, Vera G.; Bolt, Arjen; Geertzen, Jan H.; Emmelot, Cornelis H.; Baars, Erwin C.; Dijkstra, Pieter U.

    de Boer-Wilzing VG, Bolt A, Geertzen JH, Emmelot CH, Baars EC, Dijkstra PU. Variation in results of volume measurements of stumps of lower-limb amputees: a comparison of 4 methods. Arch Phys Med Rehabil 2011;92:941-6. Objective: To analyze the reliability of 4 methods (water immersion,

  6. Interobserver variations of target volume delineation and its impact on irradiated volume in accelerated partial breast irradiation with intraoperative interstitial breast implant

    Directory of Open Access Journals (Sweden)

    Ritu Raj Upreti

    2017-02-01

    Full Text Available Purpose: To investigate the interobserver variations in delineation of lumpectomy cavity (LC and clinical target volume (CTV, and its impact on irradiated volume in accelerated partial breast irradiation using intraoperative multicatheter brachytherapy. Material and methods : Delineation of LC and CTV was done by five radiation oncologists on planning computed tomography (CT scans of 20 patients with intraoperative interstitial breast implant. Cavity visualization index (CVI, four-point index ranging from (0 = poor to (3 = excellent was created and assigned by observers for each patient. In total, 200 contours for all observers and 100 treatment plans were evaluated. Spatial concordance (conformity index, CI common , and CIgen, average shift in the center of mass (COM, and ratio of maximum and minimum volumes (V max /V min of LC and CTV were quantified among all observers and statistically analyzed. Variation in active dwell positions (0.5 cm step for each catheter, total reference air kerma (TRAK, volume enclosed by prescription isodose (V100% among observers and its spatial concordance were analyzed. Results : The mean ± SD CI common of LC and CTV was 0.54 ± 0.09, and 0.58 ± 0.08, respectively. Conformity index tends to increase, shift in COM and V max /V min decrease significantly (p < 0.05, as CVI increased. Out of total 309 catheters, 29.8% catheters had no change, 29.8% and 17.5% catheters had variations of 1 and 2 dwell positions (0.5 cm and 1 cm, respectively. 9.3% catheters shown variations ≥ 10 dwell positions (5 cm. The mean ± SD CI common of V100% was 0.75 ± 0.11. The mean observed V max /V min of prescription isodose and TRAK was 1.18 (range, 1.03 to 1.56 and 1.11 (range, 1.03 to 1.35, respectively. Conclusions : Interobserver variability in delineation of target volume was found to be significantly related to CVI. Smaller variability was observed with excellent visualization of LC. Interobserver variations showed dosimetric

  7. A correlation study on position and volume variation of primary lung cancer during respiration by four-dimensional CT

    International Nuclear Information System (INIS)

    Zhang Yingjie; Li Jianbin; Tian Shiyu; Li Fengxiang; Fan Tingyong; Shao Qian; Xu Min; Lu Jie

    2011-01-01

    Objective: To investigate the correlation of position movement of primary tumor with interested organs and skin markers, and to investigate the correlation of volume variation of primary tumors and lungs during different respiration phases for patients with lung cancer at free breath condition scanned by four-dimensional CT (4DCT) simulation. Methods: 16 patients with lung cancer were scanned at free breath condition by simulation 4DCT which connected to a respiration-monitoring system. A coordinate system was created based on image of T 5 phase,gross tumor volume (GTV) and normal tissue structures of 10 phases were contoured. The three dimensional position variation of them were measured and their correlation were analyzed, and the same for the volume variation of GTV and lungs of 10 respiratory phases. Results: Movement range of lung cancer in different lobe differed extinct: 0.8 - 5.0 mm in upper lobe, 5.7 -5.9 mm in middle lobe and 10.2 - 13.7 mm in lower lobe, respectively. Movement range of lung cancer in three dimensional direction was different: z-axis 4.3 mm ± 4.3 mm > y-axis 2.2 mm ± 1.0 mm > x-axis 1.7 mm ± 1.5 mm (χ 2 =16.22, P =0.000), respectively. There was no statistical significant correlation for movement vector of GTV and interested structures (r =-0.50 - -0.01, P =0.058 - -0.961), nor for volume variation of tumor and lung (r =0.23, P =0.520). Conclusions: Based on 4DCT, statistically significant differences of GTV centroid movement are observed at different pulmonary lobes and in three dimensional directions. So individual 4DCT measurement is necessary for definition of internal target volume margin for lung cancer. (authors)

  8. Cone Beam CT Imaging Analysis of Interfractional Variations in Bladder Volume and Position During Radiotherapy for Bladder Cancer

    International Nuclear Information System (INIS)

    Yee, Don; Parliament, Matthew; Rathee, Satyapal; Ghosh, Sunita; Ko, Lawrence; Murray, Brad

    2010-01-01

    Purpose: To quantify daily bladder size and position variations during bladder cancer radiotherapy. Methods and Materials: Ten bladder cancer patients underwent daily cone beam CT (CBCT) imaging of the bladder during radiotherapy. Bladder and planning target volumes (bladder/PTV) from CBCT and planning CT scans were compared with respect to bladder center-of-mass shifts in the x (lateral), y (anterior-posterior), and z (superior-inferior) coordinates, bladder/PTV size, bladder/PTV margin positions, overlapping areas, and mutually exclusive regions. Results: A total of 262 CBCT images were obtained from 10 bladder cancer patients. Bladder center of mass shifted most in the y coordinate (mean, -0.32 cm). The anterior bladder wall shifted the most (mean, -0.58 cm). Mean ratios of CBCT-derived bladder and PTV volumes to planning CT-derived counterparts were 0.83 and 0.88. The mean CBCT-derived bladder volume (± standard deviation [SD]) outside the planning CT counterpart was 29.24 cm 3 (SD, 29.71 cm 3 ). The mean planning CT-derived bladder volume outside the CBCT counterpart was 47.74 cm 3 (SD, 21.64 cm 3 ). The mean CBCT PTV outside the planning CT-derived PTV was 47.35 cm 3 (SD, 36.51 cm 3 ). The mean planning CT-derived PTV outside the CBCT-derived PTV was 93.16 cm 3 (SD, 50.21). The mean CBCT-derived bladder volume outside the planning PTV was 2.41 cm 3 (SD, 3.97 cm 3 ). CBCT bladder/ PTV volumes significantly differed from planning CT counterparts (p = 0.047). Conclusions: Significant variations in bladder and PTV volume and position occurred in patients in this trial.

  9. Variation in the Definition of Clinical Target Volumes for Pelvic Nodal Conformal Radiation Therapy for Prostate Cancer

    International Nuclear Information System (INIS)

    Lawton, Colleen A.F.; Michalski, Jeff; El-Naqa, Issam; Kuban, Deborah; Lee, W. Robert; Rosenthal, Seth A.; Zietman, Anthony; Sandler, Howard; Shipley, William; Ritter, Mark; Valicenti, Richard; Catton, Charles; Roach, Mack; Pisansky, Thomas M.; Seider, Michael

    2009-01-01

    Purpose: We conducted a comparative study of clinical target volume (CTV) definition of pelvic lymph nodes by multiple genitourinary (GU) radiation oncologists looking at the levels of discrepancies amongst this group. Methods and Materials: Pelvic computed tomography (CT) scans from 2 men were distributed to 14 Radiation Therapy Oncology Group GU radiation oncologists with instructions to define CTVs for the iliac and presacral lymph nodes. The CT data with contours were then returned for analysis. In addition, a questionnaire was completed that described the physicians' method for target volume definition. Results: Significant variation in the definition of the iliac and presacral CTVs was seen among the physicians. The minimum, maximum, mean (SD) iliac volumes (mL) were 81.8, 876.6, 337.6 ± 203 for case 1 and 60.3, 627.7, 251.8 ± 159.3 for case 2. The volume of 100% agreement was 30.6 and 17.4 for case 1 and 2 and the volume of the union of all contours was 1,012.0 and 807.4 for case 1 and 2, respectively. The overall agreement was judged to be moderate in both cases (kappa = 0.53 (p < 0.0001) and kappa = 0.48 (p < 0.0001). There was no volume of 100% agreement for either of the two presacral volumes. These variations were confirmed in the responses to the associated questionnaire. Conclusions: Significant disagreement exists in the definition of the CTV for pelvic nodal radiation therapy among GU radiation oncology specialists. A consensus needs to be developed so as to accurately assess the merit and safety of such treatment.

  10. A general methodology for three-dimensional analysis of variation in target volume delineation

    NARCIS (Netherlands)

    Remeijer, P.; Rasch, C.; Lebesque, J. V.; van Herk, M.

    1999-01-01

    A generic method for three-dimensional (3-D) evaluation of target volume delineation in multiple imaging modalities is presented. The evaluation includes geometrical and statistical methods to estimate observer differences and variability in defining the Gross Tumor Volume (GTV) in relation to the

  11. Variations in cereal volume affect the amount selected and eaten for breakfast

    OpenAIRE

    Rolls, Barbara J.; Meengs, Jennifer S.; Roe, Liane S.

    2014-01-01

    Food volume could influence both the portions that people take and the amount that they eat, but these effects have had little investigation. The influence of food volume was tested by systematically reducing the flake size of a breakfast cereal so that the cereal was more compact and the same weight filled a smaller volume. In a crossover design, 41 adults ate cereal for breakfast once a week for four weeks during 2011-2012. The cereal was either standard wheat flakes or th...

  12. Variations in gastric emptying of liquid elicited by acute blood volume changes in awake rats

    Directory of Open Access Journals (Sweden)

    Gondim F. de-A.A.

    1998-01-01

    Full Text Available We have observed that acute blood volume expansion increases the gastroduodenal resistance to the flow of liquid in anesthetized dogs, while retraction decreases it (Santos et al. (1991 Acta Physiologica Scandinavica, 143: 261-269. This study evaluates the effect of blood volume expansion and retraction on the gastric emptying of liquid in awake rats using a modification of the technique of Scarpignato (1980 (Archives Internationales de Pharmacodynamie et de Therapie, 246: 286-294. Male Wistar rats (180-200 g were fasted for 16 h with water ad libitum and 1.5 ml of the test meal (0.5 mg/ml phenol red solution in 5% glucose was delivered to the stomach immediately after random submission to one of the following protocols: 1 normovolemic control (N = 22, 2 expansion (N = 72 by intravenous infusion (1 ml/min of Ringer-bicarbonate solution, volumes of 1, 2, 3 or 5% body weight, or 3 retraction (N = 22 by controlled bleeding (1.5 ml/100 g. Gastric emptying of liquid was inhibited by 19-51.2% (P<0.05 after blood volume expansion (volumes of 1, 2, 3 or 5% body weight. Blood volume expansion produced a sustained increase in central venous pressure while mean arterial pressure was transiently increased during expansion (P<0.05. Blood volume retraction increased gastric emptying by 28.5-49.9% (P<0.05 and decreased central venous pressure and mean arterial pressure (P<0.05. Infusion of the shed blood 10 min after bleeding reversed the effect of retraction on gastric emptying. These findings suggest that gastric emptying of liquid is subject to modulation by the blood volume.

  13. Variations in cereal volume affect the amount selected and eaten for breakfast.

    Science.gov (United States)

    Rolls, Barbara J; Meengs, Jennifer S; Roe, Liane S

    2014-09-01

    Food volume could influence both the portions that people take and the amount that they eat, but these effects have had little investigation. The influence of food volume was tested by systematically reducing the flake size of a breakfast cereal so that the cereal was more compact and the same weight filled a smaller volume. In a crossover design, 41 adults ate cereal for breakfast once a week for 4 weeks during 2011 and 2012. The cereal was either standard wheat flakes or the same cereal crushed to reduce the volume to 80%, 60%, or 40% of the standard. A constant weight of cereal was provided in an opaque container and participants poured the amount they wanted into a bowl, added fat-free milk and noncalorie sweetener as desired, and consumed as much as they wanted. Results from a mixed linear model showed that as flake size was reduced, subjects poured a smaller volume of cereal, but still took a greater amount by weight and energy content (both P values breakfast energy intake increased from a mean±standard error of the mean of 286±18 kcal to 358±19 kcal, an increase of a mean±standard error of the mean 34%±7% (Pportion served, which in turn affects energy intake. Copyright © 2014 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

  14. Variations of comoving volume and their effects on the star formation rate density

    Science.gov (United States)

    Kim, Sungeun; Physics and Astronomy, Sejong University, Seoul, Korea (the Republic of).

    2018-01-01

    To build a comprehensive picture of star formation in the universe, we havedeveloped an application to calculate the comoving volume at a specific redshift and visualize the changes of spaceand time. The application is based on the star formation rates of about a few thousands of galaxies and their redshiftvalues. Three dimensional modeling of these galaxies using the redshift, comoving volume, and star formation ratesas input data allows calculation of the star formation rate density corresponding to the redshift. This work issupported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP)(no. 2017037333).

  15. Spatial variation in void volume during charged particle bombardment: the effects of injected interstitials

    International Nuclear Information System (INIS)

    Lee, E.H.; Mansur, L.K.; Yoo, M.H.

    1979-01-01

    Experimental observations of the void volume at several depths along the range of 4 MeV Ni ions in 316 stainless steel are reported. The specimens were first preconditioned by neutron irradiation at temperatures of 450 and 584 0 C to fluences of approximately 8 x 10 26 n/m -2 . The void volume after ion bombardment to 60 dpa at the peak damage depth is significantly lower at the peak damage depth than in the region between that and the free surface. The ratio of the step height to void volume at the depth of peak energy deposition between regions masked from and exposed to the beam is strongly dependent on bombardment temperature. The reduction of void volume near the peak damage depth is larger for the 584 0 C than for the 450 0 C preconditioned material. These observations are consistent with recent theoretical results which account for the injection of the bombarding ions as self-interstitials. The theory necessary to understand the effect is developed

  16. 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.

  17. 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.

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

    Science.gov (United States)

    Farkas, Ágnes; Molnár, Réka; Morschhauser, Tamás; Hahn, István

    2012-01-01

    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. PMID:22619588

  19. Evaluation of axillary dose coverage following whole breast radiotherapy: Variation with the breast volume and shape

    International Nuclear Information System (INIS)

    Aguiar, Artur; Gomes Pereira, Helena; Azevedo, Isabel; Gomes, Luciano

    2015-01-01

    Objective: To evaluate the axillary dose coverage in patients treated with tridimensional whole breast radiotherapy (3D-WBRT), according to the breast volume and shape in treatment position. Background: Several studies have demonstrated an insufficient dose contribution to the axillary levels, using 3D-WBRT, remaining unclear whether the breast volume and shape can influence it. Materials and methods: We retrospectively delineated the axillary levels on planning CT-images of 100 patients, treated with 3D-WBRT along 2012 in our institution. To estimate the shape we established an anatomic CT-based interval, defined as the Thoracic Extent (TE). The breast volume matched its CTV. Mean dose levels and V95 (volume receiving at least 95% of the prescribed dose) were evaluated. Results: Mean axillary level I (A1), II (A2) and III (A3) volume was 56.1 cc, 16.5 cc and 18.9 cc, respectively, and mean doses were 43.9 Gy, 38.6 Gy and 19.5 Gy. For breast volumes of <800 cc, 800–999 cc, 1000–1199 cc and >1200 cc, mean A1 V95 was 38%, 51%, 61.2% and 57.2% whereas median A2 V95 was 8.3%, 13.4%, 19.4% and 28% respectively. Regarding shape, where the breast relative position to the TE was categorized in intervals between 31% and 40%, 41% and 50%, 51% and 60%, and 61% and 70%, mean A1 V95 was 38.7%, 43.1%, 51.1% and 77.3% whereas mean A2 V95 was 6.1%, 11.2%, 17.1% and 37% respectively. Conclusions: We observed inadequate dose coverage to all axillary levels, even after applying a sub-analysis accounting for different breast volumes and shapes. Although higher doses were associated with the more voluminous and pendulous breasts, axillary coverage with 3D-WBRT seems to be inefficient, regardless of the breast morphology

  20. FURTHER STUDIES ON THE VARIATION OF SPRAY DEPOSITS IN VINEYARDS WITH AIRFLOW RATE AND VOLUME RATE

    Directory of Open Access Journals (Sweden)

    Emanuele Cerruto

    2007-03-01

    Full Text Available The present research, continuing that reported in [2], deals with the spray application subject, so to investigate as volume rate and airflow rate, forward speed being equal, affect the foliar deposition in an espalier vineyard. Experimental trials were carried out by means of an air assisted towed sprayer, equipped with “Albuz ATR” nozzles. To take into account the influence of the development of the trees, the field trials were replicated in two phenological stages with an interval of about one month: “Inflorescences fully developed” (stage 1 and “Beginning of berry touch” (stage 2. A full factorial experiment was carried out for each growth stage, with two airflow rates (3.9 and 7.5 m3/s, three volume rates (103, 216, and 276 L/ha in the first growth stage and 154, 330 and 432 L/ha in the second growth stage, and four replicates, arranged according to a randomised complete block design. Working pressure (1.2 MPa and forward speed (1.4 m/s were kept unchanged for all the trials. The foliar deposition was measured by means of a spectrophotometric technique. The leaves were sampled on two depth layers and two or three heights, according to the trees’ development. The results showed that volume rate did not significantly influence the mean foliar deposition in both the two growth stages, while the highest deposits were obtained with the lowest airflow rate. The airflow rate × volume rate interaction, though not statistically significant, showed that low volume rates together with high airflow rates, result in a noticeable reduction in foliar deposition (29% with respect the grand mean, due to an increase of the spry drift, especially at the first growth stage, when the foliar development is little. These second tests, unlike those described in [2], did not show any positive influence of the airflow rate on the foliar deposition in the inner part of the canopy, so further investigations could be necessary to better understand the

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

    International Nuclear Information System (INIS)

    Ki, Yongkan; Kim, Wontaek; Nam, Jiho; Kim, Donghyun; Lee, Juhye; Park, Dahl; Jeon, Hosang; Ha, Honggu; Kim, Taenam; Kim, Dongwon

    2013-01-01

    Purpose: To investigate the effect of the probiotic Lactobacillus acidophilus on the percentage volume change of the rectum (PVC 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 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 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 R values than the placebo group. L acidophilus showed a significant reduction effect on the PVC R (P R . Conclusions: L acidophilus was useful in reducing the PVC R , which is the most important determining factor of prostate position, during radiation therapy for prostate cancer

  2. 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.

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

    Directory of Open Access Journals (Sweden)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

  5. Variations of target volume definition and daily target volume localization in stereotactic body radiotherapy for early-stage non–small cell lung cancer patients under abdominal compression

    Energy Technology Data Exchange (ETDEWEB)

    Han, Chunhui, E-mail: chan@coh.org; Sampath, Sagus; Schultheisss, Timothy E.; Wong, Jeffrey Y.C.

    2017-07-01

    We aimed to compare gross tumor volumes (GTV) in 3-dimensional computed tomography (3DCT) simulation and daily cone beam CT (CBCT) with the internal target volume (ITV) in 4-dimensional CT (4DCT) simulation in stereotactic body radiotherapy (SBRT) treatment of patients with early-stage non–small cell lung cancer (NSCLC) under abdominal compression. We retrospectively selected 10 patients with NSCLC who received image-guided SBRT treatments under abdominal compression with daily CBCT imaging. GTVs were contoured as visible gross tumor on the planning 3DCT and daily CBCT, and ITVs were contoured using maximum intensity projection (MIP) images of the planning 4DCT. Daily CBCTs were registered with 3DCT and MIP images by matching of bony landmarks in the thoracic region to evaluate interfractional GTV position variations. Relative to MIP-based ITVs, the average 3DCT-based GTV volume was 66.3 ± 17.1% (range: 37.5% to 92.0%) (p < 0.01 in paired t-test), and the average CBCT-based GTV volume was 90.0 ± 6.7% (daily range: 75.7% to 107.1%) (p = 0.02). Based on bony anatomy matching, the center-of-mass coordinates for CBCT-based GTVs had maximum absolute shift of 2.4 mm (left-right), 7.0 mm (anterior-posterior [AP]), and 5.2 mm (superior-inferior [SI]) relative to the MIP-based ITV. CBCT-based GTVs had average overlapping ratio of 81.3 ± 11.2% (range: 45.1% to 98.9%) with the MIP-based ITV, and 57.7 ± 13.7% (range: 35.1% to 83.2%) with the 3DCT-based GTV. Even with abdominal compression, both 3DCT simulations and daily CBCT scans significantly underestimated the full range of tumor motion. In daily image-guided patient setup corrections, automatic bony anatomy-based image registration could lead to target misalignment. Soft tissue-based image registration should be performed for accurate treatment delivery.

  6. SU-E-T-427: Cell Surviving Fractions Derived From Tumor-Volume Variation During Radiotherapy for Non-Small Cell Lung Cancer: Comparison with Predictive Assays

    International Nuclear Information System (INIS)

    Chvetsov, A; Schwartz, J; Mayr, N; Yartsev, S

    2014-01-01

    Purpose: To show that a distribution of cell surviving fractions S 2 in a heterogeneous group of patients can be derived from tumor-volume variation curves during radiotherapy for non-small cell lung cancer. Methods: Our analysis was based on two data sets of tumor-volume variation curves for heterogeneous groups of 17 patients treated for nonsmall cell lung cancer with conventional dose fractionation. The data sets were obtained previously at two independent institutions by using megavoltage (MV) computed tomography (CT). Statistical distributions of cell surviving fractions S 2 and cell clearance half-lives of lethally damaged cells T1/2 have been reconstructed in each patient group by using a version of the two-level cell population tumor response model and a simulated annealing algorithm. The reconstructed statistical distributions of the cell surviving fractions have been compared to the distributions measured using predictive assays in vitro. Results: Non-small cell lung cancer presents certain difficulties for modeling surviving fractions using tumor-volume variation curves because of relatively large fractional hypoxic volume, low gradient of tumor-volume response, and possible uncertainties due to breathing motion. Despite these difficulties, cell surviving fractions S 2 for non-small cell lung cancer derived from tumor-volume variation measured at different institutions have similar probability density functions (PDFs) with mean values of 0.30 and 0.43 and standard deviations of 0.13 and 0.18, respectively. The PDFs for cell surviving fractions S 2 reconstructed from tumor volume variation agree with the PDF measured in vitro. Comparison of the reconstructed cell surviving fractions with patient survival data shows that the patient survival time decreases as the cell surviving fraction increases. Conclusion: The data obtained in this work suggests that the cell surviving fractions S 2 can be reconstructed from the tumor volume variation curves measured

  7. Surface area and the seabed area, volume, depth, slope, and topographic variation for the world's seas, oceans, and countries.

    Science.gov (United States)

    Costello, Mark John; Cheung, Alan; De Hauwere, Nathalie

    2010-12-01

    Depth and topography directly and indirectly influence most ocean environmental conditions, including light penetration and photosynthesis, sedimentation, current movements and stratification, and thus temperature and oxygen gradients. These parameters are thus likely to influence species distribution patterns and productivity in the oceans. They may be considered the foundation for any standardized classification of ocean ecosystems and important correlates of metrics of biodiversity (e.g., species richness and composition, fisheries). While statistics on ocean depth and topography are often quoted, how they were derived is rarely cited, and unless calculated using the same spatial resolution the resulting statistics will not be strictly comparable. We provide such statistics using the best available resolution (1-min) global bathymetry, and open source digital maps of the world's seas and oceans and countries' Exclusive Economic Zones, using a standardized methodology. We created a terrain map and calculated sea surface and seabed area, volume, and mean, standard deviation, maximum, and minimum, of both depth and slope. All the source data and our database are freely available online. We found that although the ocean is flat, and up to 71% of the area has a ocean volume exceeds 1.3 billion km(3) (or 1.3 sextillion liters), and sea surface and seabed areas over 354 million km(2). We propose the coefficient of variation of slope as an index of topographic heterogeneity. Future studies may improve on this database, for example by using a more detailed bathymetry, and in situ measured data. The database could be used to classify ocean features, such as abyssal plains, ridges, and slopes, and thus provide the basis for a standards based classification of ocean topography.

  8. Observer variation in target volume delineation of lung cancer related to radiation oncologist-computer interaction: A 'Big Brother' evaluation

    International Nuclear Information System (INIS)

    Steenbakkers, Roel J.H.M.; Duppen, Joop C.; Fitton, Isabelle; Deurloo, Kirsten E.I.; Zijp, Lambert; Uitterhoeve, Apollonia L.J.; Rodrigus, Patrick T.R.; Kramer, Gijsbert W.P.; Bussink, Johan; Jaeger, Katrien De; Belderbos, Jose S.A.; Hart, Augustinus A.M.; Nowak, Peter J.C.M.; Herk, Marcel van; Rasch, Coen R.N.

    2005-01-01

    Background and purpose: To evaluate the process of target volume delineation in lung cancer for optimization of imaging, delineation protocol and delineation software. Patients and methods: Eleven radiation oncologists (observers) from five different institutions delineated the Gross Tumor Volume (GTV) including positive lymph nodes of 22 lung cancer patients (stages I-IIIB) on CT only. All radiation oncologist-computer interactions were recorded with a tool called 'Big Brother'. For each radiation oncologist and patient the following issues were analyzed: delineation time, number of delineated points and corrections, zoom levels, level and window (L/W) settings, CT slice changes, use of side windows (coronal and sagittal) and software button use. Results: The mean delineation time per GTV was 16 min (SD 10 min). The mean delineation time for lymph node positive patients was on average 3 min larger (P=0.02) than for lymph node negative patients. Many corrections (55%) were due to L/W change (e.g. delineating in mediastinum L/W and then correcting in lung L/W). For the lymph node region, a relatively large number of corrections was found (3.7 corr/cm 2 ), indicating that it was difficult to delineate lymph nodes. For the tumor-atelectasis region, a relative small number of corrections was found (1.0 corr/cm 2 ), indicating that including or excluding atelectasis into the GTV was a clinical decision. Inappropriate use of L/W settings was frequently found (e.g. 46% of all delineated points in the tumor-lung region were delineated in mediastinum L/W settings). Despite a large observer variation in cranial and caudal direction of 0.72 cm (1 SD), the coronal and sagittal side windows were not used in 45 and 60% of the cases, respectively. For the more difficult cases, observer variation was smaller when the coronal and sagittal side windows were used. Conclusions: With the 'Big Brother' tool a method was developed to trace the delineation process. The differences between

  9. Bladder filling variations during concurrent chemotherapy and pelvic radiotherapy in rectal cancer patients: early experience of bladder volume assessment using ultrasound scanner

    International Nuclear Information System (INIS)

    Chang, Jee Suk; Yoon, Hong In; Cha, Hye Jung; Chang, Yoon Sun; Cho, Yeo Na; Keum, Ki Chang; Koom, Woong Sub

    2013-01-01

    To describe the early experience of analyzing variations and time trends in bladder volume of the rectal cancer patients who received bladder ultrasound scan. We identified 20 consecutive rectal cancer patients who received whole pelvic radiotherapy (RT) and bladder ultrasound scan between February and April 2012. Before simulation and during the entire course of treatment, patients were scanned with portable automated ultrasonic bladder scanner, 5 times consecutively, and the median value was reported. Then a radiation oncologist contoured the bladder inner wall shown on simulation computed tomography (CT) and calculated its volume. Before simulation, the median bladder volume measured using simulation CT and bladder ultrasound scan was 427 mL (range, 74 to 1,172 mL) and 417 mL (range, 147 to 1,245 mL), respectively. There was strong linear correlation (R = 0.93, p < 0.001) between the two results. During the course of treatment, there were wide variations in the bladder volume and every time, measurements were below the baseline with statistical significance (12/16). At 6 weeks after RT, the median volume was reduced by 59.3% to 175 mL. Compared to the baseline, bladder volume was reduced by 38% or 161 mL on average every week for 6 weeks. To our knowledge, this study is the first to prove that there are bladder volume variations and a reduction in bladder volume in rectal cancer patients. Moreover, our results will serve as the basis for implementation of bladder training to patients receiving RT with full bladder.

  10. Cell cycle variation in x-ray survival for cells from spheroids measured by volume cell sorting

    International Nuclear Information System (INIS)

    Freyer, J.P.; Wilder, M.E.; Raju, M.R.

    1984-01-01

    Considerable work has been done studying the variation in cell survival as a function of cell cycle position for monolayers or single cells exposed to radiation. Little is known about the effects of multicellular growth on the relative radiation sensitivity of cells in different cell cycle stages. The authors have developed a new technique for measuring the response of cells, using volume cell sorting, which is rapid, non-toxic, and does not require cell synchronization. By combining this technique with selective spheroid dissociation,they have measured the age response of cells located at various depths in EMT6 and Colon 26 spheroids. Although cells in the inner region had mostly G1-phase DNA contents, 15-20% had S- and G2-phase DNA contents. Analysis of these cells using BrdU labeling and flow cytometric analysis with a monoclonal antibody to BrdU indicated that the inner region cells were not synthesizing DNA. Thus, the authors were able to measure the radiation response of cells arrested in G1, S and G2 cell cycle phases. Comparison of inner and outer spheroid regions, and monolayer cultures, indicates that it is improper to extrapolate age response data in standard culture conditions to the situation in spheroids

  11. SU-E-T-427: Cell Surviving Fractions Derived From Tumor-Volume Variation During Radiotherapy for Non-Small Cell Lung Cancer: Comparison with Predictive Assays

    Energy Technology Data Exchange (ETDEWEB)

    Chvetsov, A; Schwartz, J; Mayr, N [University of Washington, Seattle, WA (United States); Yartsev, S [London Health Sciences Centre, London, Ontario (Canada)

    2014-06-01

    Purpose: To show that a distribution of cell surviving fractions S{sub 2} in a heterogeneous group of patients can be derived from tumor-volume variation curves during radiotherapy for non-small cell lung cancer. Methods: Our analysis was based on two data sets of tumor-volume variation curves for heterogeneous groups of 17 patients treated for nonsmall cell lung cancer with conventional dose fractionation. The data sets were obtained previously at two independent institutions by using megavoltage (MV) computed tomography (CT). Statistical distributions of cell surviving fractions S{sup 2} and cell clearance half-lives of lethally damaged cells T1/2 have been reconstructed in each patient group by using a version of the two-level cell population tumor response model and a simulated annealing algorithm. The reconstructed statistical distributions of the cell surviving fractions have been compared to the distributions measured using predictive assays in vitro. Results: Non-small cell lung cancer presents certain difficulties for modeling surviving fractions using tumor-volume variation curves because of relatively large fractional hypoxic volume, low gradient of tumor-volume response, and possible uncertainties due to breathing motion. Despite these difficulties, cell surviving fractions S{sub 2} for non-small cell lung cancer derived from tumor-volume variation measured at different institutions have similar probability density functions (PDFs) with mean values of 0.30 and 0.43 and standard deviations of 0.13 and 0.18, respectively. The PDFs for cell surviving fractions S{sup 2} reconstructed from tumor volume variation agree with the PDF measured in vitro. Comparison of the reconstructed cell surviving fractions with patient survival data shows that the patient survival time decreases as the cell surviving fraction increases. Conclusion: The data obtained in this work suggests that the cell surviving fractions S{sub 2} can be reconstructed from the tumor volume

  12. 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.

  13. Reduce in Variation and Improve Efficiency of Target Volume Delineation by a Computer-Assisted System Using a Deformable Image Registration Approach

    International Nuclear Information System (INIS)

    Chao, K.S. Clifford; Bhide, Shreerang FRCR; Chen, Hansen; Asper, Joshua PAC; Bush, Steven; Franklin, Gregg; Kavadi, Vivek; Liengswangwong, Vichaivood; Gordon, William; Raben, Adam; Strasser, Jon; Koprowski, Christopher; Frank, Steven; Chronowski, Gregory; Ahamad, Anesa; Malyapa, Robert; Zhang Lifei; Dong Lei

    2007-01-01

    Purpose: To determine whether a computer-assisted target volume delineation (CAT) system using a deformable image registration approach can reduce the variation of target delineation among physicians with different head and neck (HN) IMRT experiences and reduce the time spent on the contouring process. Materials and Methods: We developed a deformable image registration method for mapping contours from a template case to a patient case with a similar tumor manifestation but different body configuration. Eight radiation oncologists with varying levels of clinical experience in HN IMRT performed target delineation on two HN cases, one with base-of-tongue (BOT) cancer and another with nasopharyngeal cancer (NPC), by first contouring from scratch and then by modifying the contours deformed by the CAT system. The gross target volumes were provided. Regions of interest for comparison included the clinical target volumes (CTVs) and normal organs. The volumetric and geometric variation of these regions of interest and the time spent on contouring were analyzed. Results: We found that the variation in delineating CTVs from scratch among the physicians was significant, and that using the CAT system reduced volumetric variation and improved geometric consistency in both BOT and NPC cases. The average timesaving when using the CAT system was 26% to 29% for more experienced physicians and 38% to 47% for the less experienced ones. Conclusions: A computer-assisted target volume delineation approach, using a deformable image-registration method with template contours, was able to reduce the variation among physicians with different experiences in HN IMRT while saving contouring time

  14. Inter fraction variations in rectum and bladder volumes and dose distributions during high dose rate brachytherapy treatment of the uterine cervix investigated by repetitive CT-examinations

    International Nuclear Information System (INIS)

    Hellebust, Taran Paulsen; Dale, Einar; Skjoensberg, Ane; Olsen, Dag Rune

    2001-01-01

    Purpose: To evaluate variation of dose to organs at risk for patients receiving fractionated high dose rate gynaecological brachytherapy by using CT-based 3D treatment planning and dose-volume histograms (DVH). Materials and methods: Fourteen patients with cancer of the uterine cervix underwent three to six CT examinations (mean 4.9) during their course of high-dose-rate brachytherapy using radiographically compatible applicators. The rectal and bladder walls were delineated and DVHs were calculated. Results: Inter fraction variation of the bladder volume (CV mean =44.1%) was significantly larger than the inter fraction variation of the mean dose (CV mean =19.9%, P=0.005) and the maximum dose (CV mean =17.5%, P=0.003) of the bladder wall. The same trend was seen for rectum, although the figures were not significantly different. Performing CT examinations at four of seven brachytherapy fractions reduced the uncertainty to 4 and 7% for the bladder and rectal doses, respectively. A linear regression analysis showed a significant, negative relationship between time after treatment start and the whole bladder volume (P=0.018), whereas no correlation was found for the rectum. For both rectum and bladder a linear regression analysis revealed a significant, negative relationship between the whole volume and median dose (P<0.05). Conclusion: Preferably a CT examination should be provided at every fraction. However, this is logistically unfeasible in most institutions. To obtain reliable DVHs the patients will in the future undergo 3-4 CT examinations during the course of brachytherapy at our institution. Since this study showed an association between large bladder volumes and dose reductions, the patients will be treated with a standardized bladder volume

  15. Variations in CT determination of target volume with active breath co-ordinate in radiotherapy for post-operative gastric cancer.

    Science.gov (United States)

    Li, Gui-Chao; Zhang, Zhen; Ma, Xue-Jun; Yu, Xiao-Li; Hu, Wei-Gang; Wang, Jia-Zhou; Li, Qi-Wen; Liang, Li-Ping; Shen, Li-Jun; Zhang, Hui; Fan, Ming

    2016-01-01

    To investigate interobserver and inter-CT variations in using the active breath co-ordinate technique in the determination of clinical tumour volume (CTV) and normal organs in post-operative gastric cancer radiotherapy. Ten gastric cancer patients were enrolled in our study, and four radiation oncologists independently determined the CTVs and organs at risk based on the CT simulation data. To determine interobserver and inter-CT variation, we evaluated the maximum dimensions, derived volume and distance between the centres of mass (CMs) of the CTVs. We assessed the reliability in CTV determination among the observers by conformity index (CI). The average volumes ± standard deviation (cm(3)) of the CTV, liver, left kidney and right kidney were 674 ± 138 (range, 332-969), 1000 ± 138 (range, 714-1320), 149 ± 13 (range, 104-183) and 141 ± 21 (range, 110-186) cm(3), respectively. The average inter-CT distances between the CMs of the CTV, liver, left kidney and right kidney were 0.40, 0.56, 0.65 and 0.6 cm, respectively; the interobserver values were 0.98, 0.53, 0.16 and 0.15 cm, respectively. In the volume size of CTV for post-operative gastric cancer, there were significant variations among multiple observers, whereas there was no variation between different CTs. The slices in which variations more likely occur were the slices of the lower verge of the hilum of the spleen and porta hepatis, then the paraoesophageal lymph nodes region and abdominal aorta, and the inferior vena cava, and the variation in the craniocaudal orientation from the interobserver was more predominant than that from inter-CT. First, this is the first study to evaluate the interobserver and inter-CT variations in the determination of the CTV and normal organs in gastric cancer with the use of the active breath co-ordinate technique. Second, we analysed the region where variations most likely occur. Third, we investigated the influence of interobserver variation on

  16. 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.

  17. [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.

  18. Seasonal variations in the volume of the haemolymph and body weight of the horseshoe crab, Tachypleus gigas (Muller)

    Digital Repository Service at National Institute of Oceanography (India)

    Chatterji, A.; Rathod, V.; Parulekar, A.H.

    in sizes between 121-140 mm. An inverse relationship was observed between the volume of haemolymph and salinity of the environment. Maximum volume of haemolymph (57.3 ml) in females was observed when the salinity of the environment was low in October...

  19. The study of dose variation and change of heart volume using 4D-CT in left breast radiation therapy

    International Nuclear Information System (INIS)

    Park, Seon Mi; Cheon, Geum Seong; Heo, Gyeong Hun; Shin, Sung Pil; Kim, Kwang Seok; Kim, Chang Uk; Kim, Hoi Nam

    2013-01-01

    We investigate the results of changed heart volume and heart dose in the left breast cancer patients while considering the movements of respiration. During the months of March and May in 2012, we designated the 10 patients who had tangential irradiation with left breast cancer in the department of radiation Oncology. With acquired images of free breathing pattern through 3D and 4D CT, we had planed enough treatment filed for covered up the whole left breast. It compares the results of the exposed dose and the volume of heart by DVH (Dose Volume histogram). Although total dose was 50.4 Gy (1.8 Gy/28 fraction), reirradiated 9 Gy (1.8 Gy/5 Fraction) with PTV (Planning Target Volume) if necessary. It compares the results of heart volume and heart dose with the free breathing in 3D CT and 4D CT. It represents the maximum difference volume of heart is 40.5%. In addition, it indicated the difference volume of maximum and minimum, average are 8.8% and 27.9%, 37.4% in total absorbed dose of heart. In case of tangential irradiation (opposite beam) in left breast cancer patients, it is necessary to consider the changed heart volume by the respiration of patient and the heartbeat of patient

  20. 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.

  1. Target volume shape variation during irradiation of rectal cancer patients in supine position: Comparison with prone position

    International Nuclear Information System (INIS)

    Nijkamp, Jasper; Jong, Rianne de; Sonke, Jan-Jakob; Vliet, Corine van; Marijnen, Corrie

    2009-01-01

    Purpose: To quantify the inter-fraction shape variation of the mesorectum for rectal cancer patients treated with 5 x 5 Gy in supine position and compare it to variation in prone position. Methods and materials: For 28 patients a planning CT (pCT) and five daily cone-beam-CT (CBCT) scans were acquired in supine position. The mesorectal part of the CTV (MesoRect) was delineated on all scans. The shape variation was quantified by the distance between the pCT- and the CBCT delineations and stored in surface maps after online setup correction. Data were analyzed for male and female patients separately and compared to prone data. Results: A large range of systematic, 1-8 mm (1SD), and random, 1-5 mm, shape variation was found, comparable to prone patients. Random-shape variation was comparable for male and female patients, while systematic variation was 3 mm larger for female patients. Conclusions: Shape variation of the MesoRect is substantial, heterogeneous and different between male and female patients. Differences between supine and prone orientation, however, are small. Clinical margins should be differentiated in position along the cranio-caudal axis, in anterior-posterior direction and for gender. Margins should also be increased, even when online setup correction is used. Due to the small margin differences between prone and supine treatments, the setup choice should be determined on dose to the organs at risk.

  2. Variations in Target Volume Definition for Postoperative Radiotherapy in Stage III Non-Small-Cell Lung Cancer: Analysis of an International Contouring Study

    International Nuclear Information System (INIS)

    Spoelstra, Femke; Senan, Suresh; Le Pechoux, Cecile; Ishikura, Satoshi; Casas, Francesc; Ball, David; Price, Allan; De Ruysscher, Dirk; Soernsen de Koste, John R. van

    2010-01-01

    Purpose: 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). Methods and Materials: 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. Results: 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. Conclusion: 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.

  3. Retro-Nasal Aroma Release Is Correlated with Variations in the In-Mouth Air Cavity Volume after Empty Deglutition

    Science.gov (United States)

    Mishellany-Dutour, Anne; Woda, Alain; Labouré, Hélène; Bourdiol, Pierre; Lachaze, Pauline; Guichard, Elisabeth; Feron, Gilles

    2012-01-01

    We hypothesized that interindividual differences in motor activities during chewing and/or swallowing were determining factors for the transfer of volatile aroma from the in-mouth air cavity (IMAC) toward the olfactory mucosa. In our first experiment, we looked for changes in IMAC volume after saliva deglutition in 12 healthy subjects. The mean IMAC volume was measured after empty deglutition using an acoustic pharyngometer device. Based on the time course of the IMAC volume after swallowing, we discerned two groups of subjects. The first group displayed a small, constant IMAC volume (2.26 mL ±0.62) that corresponded to a high tongue position. The second group displayed a progressive increase in IMAC (from 6.82 mL ±2.37 to 22.82 mL ±3.04) that corresponded to a progressive lowering of the tongue to its resting position. In our second experiment, we investigated the relationship between IMAC volume changes after deglutition and the level of aroma release at the nostril. For this purpose, the release of menthone was measured at the nostril level in 25 subjects who consumed similar amounts of a mint tablet. The subjects were separated into two groups corresponding to two levels of menthone release: high (H) and low (L). The mean volume of IMAC was measured during and after empty deglutition. Group H displayed a small, constant amplitude of IMAC volume change after deglutition, while Group L displayed a progressive increase in IMAC. It is likely that Group H continuously released the aroma through the veloglossal isthmus as the mint was consumed, while Group L trapped the aroma in the oral cavity and then released it into the nasal cavity upon swallowing. These results show that the in vivo aroma release profile in humans depends closely on the different motor patterns at work during empty deglutition. PMID:22815986

  4. Retro-nasal aroma release is correlated with variations in the in-mouth air cavity volume after empty deglutition.

    Directory of Open Access Journals (Sweden)

    Anne Mishellany-Dutour

    Full Text Available We hypothesized that interindividual differences in motor activities during chewing and/or swallowing were determining factors for the transfer of volatile aroma from the in-mouth air cavity (IMAC toward the olfactory mucosa. In our first experiment, we looked for changes in IMAC volume after saliva deglutition in 12 healthy subjects. The mean IMAC volume was measured after empty deglutition using an acoustic pharyngometer device. Based on the time course of the IMAC volume after swallowing, we discerned two groups of subjects. The first group displayed a small, constant IMAC volume (2.26 mL ±0.62 that corresponded to a high tongue position. The second group displayed a progressive increase in IMAC (from 6.82 mL ±2.37 to 22.82 mL ±3.04 that corresponded to a progressive lowering of the tongue to its resting position. In our second experiment, we investigated the relationship between IMAC volume changes after deglutition and the level of aroma release at the nostril. For this purpose, the release of menthone was measured at the nostril level in 25 subjects who consumed similar amounts of a mint tablet. The subjects were separated into two groups corresponding to two levels of menthone release: high (H and low (L. The mean volume of IMAC was measured during and after empty deglutition. Group H displayed a small, constant amplitude of IMAC volume change after deglutition, while Group L displayed a progressive increase in IMAC. It is likely that Group H continuously released the aroma through the veloglossal isthmus as the mint was consumed, while Group L trapped the aroma in the oral cavity and then released it into the nasal cavity upon swallowing. These results show that the in vivo aroma release profile in humans depends closely on the different motor patterns at work during empty deglutition.

  5. 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.

    Science.gov (United States)

    Rajeev, K R; Menon, Smrithy S; Beena, K; Holla, Raghavendra; Kumar, R Rajaneesh; Dinesh, M

    2014-01-01

    A prospective study was undertaken to evaluate the influence of patient positioning on the set up variations to determine the planning target volume (PTV) margins and to evaluate the clinical relevance volume assessment of the small bowel (SB) within the irradiated volume. During the period of months from December 2011 to April 2012, a computed tomography (CT) scan was done either in supine position or in prone position using a belly board (BB) for 20 consecutive patients. All the patients had histologically proven rectal cancer and received either post- or pre-operative pelvic irradiation. Using a three-dimensional planning system, the dose-volume histogram for SB was defined in each axial CT slice. Total dose was 46-50 Gy (2 Gy/fraction), delivered using the 4-field box technique. The set up variation of the study group was assessed from the data received from the electronic portal imaging device in the linear accelerator. The shift along X, Y, and Z directions were noted. Both systematic and random errors were calculated and using both these values the PTV margin was calculated. The systematic errors of patients treated in the supine position were 0.87 (X-mm), 0.66 (Y-mm), 1.6 (Z-mm) and in the prone position were 1.3 (X-mm), 0.59 (Y-mm), 1.17 (Z-mm). The random errors of patients treated in the supine positions were 1.81 (X-mm), 1.73 (Y-mm), 1.83 (Z-mm) and in prone position were 2.02 (X-mm), 1.21 (Y-mm), 3.05 (Z-mm). The calculated PTV margins in the supine position were 3.45 (X-mm), 2.87 (Y-mm), 5.31 (Z-mm) and in the prone position were 4.91 (X-mm), 2.32 (Y-mm), 5.08 (Z-mm). The mean volume of the peritoneal cavity was 648.65 cm 3 in the prone position and 1197.37 cm 3 in the supine position. 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.

  6. Spatial and temporal variation of residence time and storage volume of subsurface water evaluated by multi-tracers approach in mountainous headwater catchments

    Science.gov (United States)

    Tsujimura, Maki; Yano, Shinjiro; Abe, Yutaka; Matsumoto, Takehiro; Yoshizawa, Ayumi; Watanabe, Ysuhito; Ikeda, Koichi

    2015-04-01

    Headwater catchments in mountainous region are the most important recharge area for surface and subsurface waters, additionally time and stock information of the water is principal to understand hydrological processes in the catchments. However, there have been few researches to evaluate variation of residence time and storage volume of subsurface water in time and space at the mountainous headwaters especially with steep slope. We performed an investigation on age dating and estimation of storage volume using simple water budget model in subsurface water with tracing of hydrological flow processes in mountainous catchments underlain by granite, Paleozoic and Tertiary, Yamanashi and Tsukuba, central Japan. We conducted hydrometric measurements and sampling of spring, stream and ground waters in high-flow and low-flow seasons from 2008 through 2012 in the catchments, and CFCs, stable isotopic ratios of oxygen-18 and deuterium, inorganic solute constituent concentrations were determined on all water samples. Residence time of subsurface water ranged from 11 to 60 years in the granite catchments, from 17 to 32 years in the Paleozoic catchments, from 13 to 26 years in the Tertiary catchments, and showed a younger age during the high-flow season, whereas it showed an older age in the low-flow season. Storage volume of subsurface water was estimated to be ranging from 10 ^ 4 to 10 ^ 6 m3 in the granite catchments, from 10 ^ 5 to 10 ^ 7 m3 in the Paleozoic catchments, from 10 ^ 4 to 10 ^ 6 m3 in the Tertiary catchments. In addition, seasonal change of storage volume in the granite catchments was the highest as compared with those of the Paleozoic and the Tertiary catchments. The results suggest that dynamic change of hydrological process seems to cause a larger variation of the residence time and storage volume of subsurface water in time and space in the granite catchments, whereas higher groundwater recharge rate due to frequent fissures or cracks seems to cause larger

  7. Effect of Glu-B3 Allelic Variation on Sodium Dodecyl Sulfate Sedimentation Volume in Common Wheat (Triticum aestivum L.

    Directory of Open Access Journals (Sweden)

    Hongqi Si

    2013-01-01

    Full Text Available Sodium dodecyl sulfate (SDS sedimentation volume has long been used to characterize wheat flours and meals with the aim of predicting processing and end-product qualities. In order to survey the influence of low-molecular-weight glutenin subunits (LMW-GSs at Glu-B3 locus on wheat SDS sedimentation volume, a total of 283 wheat (Triticum aestivum L. varieties including landraces and improved and introduced cultivars were analyzed using 10 allele-specific PCR markers at the Glu-B3 locus. The highest allele frequency observed in the tested varieties was Glu-B3i with 21.9% in all varieties, 21.1% in landraces, 25.5% in improved cultivars, and 12% in introduced cultivars. Glu-B3 locus represented 8.6% of the variance in wheat SDS sedimentation volume, and Glu-B3b, Glu-B3g, and Glu-B3h significantly heightened the SDS sedimentation volume, but Glu-B3a, Glu-B3c, and Glu-B3j significantly lowered the SDS sedimentation volume. For the bread-making quality, the most desirable alleles Glu-B3b and Glu-B3g become more and more popular and the least desirable alleles Glu-B3a and Glu-B3c got less and less in modern improved cultivars, suggesting that wheat grain quality in China has been significantly improved through breeding effort.

  8. 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....

  9. Medication and volume delivery by gravity-driven micro-drip intravenous infusion: potential variations during "wide-open" flow.

    Science.gov (United States)

    Pierce, Eric T; Kumar, Vikram; Zheng, Hui; Peterfreund, Robert A

    2013-03-01

    Gravity-driven micro-drip infusion sets allow control of medication dose delivery by adjusting drops per minute. When the roller clamp is fully open, flow in the drip chamber can be a continuous fluid column rather than discrete, countable, drops. We hypothesized that during this "wide-open" state, drug delivery becomes dependent on factors extrinsic to the micro-drip set and is therefore difficult to predict. We conducted laboratory experiments to characterize volume delivery under various clinically relevant conditions of wide-open flow in an in vitro laboratory model. A micro-drip infusion set, plugged into a bag of normal saline, was connected to a high-flow stopcock at the distal end. Vertically oriented IV catheters (gauges 14-22) were connected to the stopcock. The fluid meniscus height in the bag was fixed (60-120 cm) above the outflow point. The roller clamp on the infusion set was in fully open position for all experiments resulting in a continuous column of fluid in the drip chamber. Fluid volume delivered in 1 minute was measured 4 times with each condition. To model resistive effects of carrier flow, volumetric infusion pumps were used to deliver various flow rates of normal saline through a carrier IV set into which a micro-drip infusion was "piggybacked." We also compared delivery by micro-drip infusion sets from 3 manufacturers. The volume of fluid delivered by gravity-driven infusion under wide-open conditions (continuous fluid column in drip chamber) varied 2.9-fold (95% confidence interval, 2.84-2.96) depending on catheter size and fluid column height. Total model resistance of the micro-drip with stopcock and catheter varied with flow rate. Volume delivered by the piggybacked micro-drip decreased up to 29.7% ± 0.8% (mean ± SE) as the carrier flow increased from 0 to 1998 mL/min. Delivery characteristics of the micro-drip infusion sets from 3 different manufacturers were similar. Laboratory simulation of clinical situations with gravity

  10. Economic impacts from energy efficiency programs - Variations in multiplier effects by program type and region. Volume 1

    International Nuclear Information System (INIS)

    Gardner, John; Skumatz, Lisa

    2007-01-01

    Research indicates that the value of omitted program effects - specifically non-energy benefits (NEBs) - represent a significant share of overall program impacts. One of the largest components of societal benefits is the direct and indirect economic and job creation effects stimulated by the investment in conservation on behalf of the program. The literature has indicated that the valuations assigned to this category of these categories can be large, but much of the literature overstates the impact of economic NEBs. We conducted extensive research to develop reliable and defensible estimates of these benefits categories. This study used input-output analysis to update the economic multipliers for NEBs in several ways. Net: Developed 'net' estimates of the multipliers (rather than 'gross' factors)Variations by Region: Estimated multipliers for multiple states and for the entire US; Variations by Program Type: Developed estimates based on different types or categories of programs (e.g weatherization vs. new construction vs. appliance programs, etc.), Variations in Baseline Assumptions: Different assumptions about where the expenditures are transferred 'from' for the net analysis (e.g. from 'generation', from a mixed market basket, etc.); and Variations over Time: Used data from multiple time periods to examine changes in the size of multipliers over time. We examined the results by state, by program type, and over time and found dramatic differences in the economic impacts by program type and territory under consideration. The results provide estimates of the economic impacts derived from the program; however, for communities or utilities with economic development goals, the results can be used to help select between program alternatives. The results are new, and the revised figures have been used to compute more reliable and tailored estimates of economic non-energy benefits that can be applied in regulatory tests

  11. Interfractional variation in bladder volume and its impact on cervical cancer radiotherapy: Clinical significance of portable bladder scanner

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Huanli; Jin, Fu; Yang, Dingyi; Wang, Ying; Li, Chao; Guo, Mingfang; Ran, Xueqi; Liu, Xianfeng; Zhou, Qi; Wu, Yongzhong, E-mail: jfazj@126.com [Department of Radiation Oncology, Chongqing Cancer Institute, No. 181, Han Yu Road, Chongqing 400030 (China)

    2016-07-15

    Purpose: A constant bladder volume (BV) is essential to direct the radiotherapy (RT) of pelvic tumors with precision. The purpose of this study was to investigate changes in BV and their impact on cervical cancer RT and to assess the clinical significance of a portable bladder scanner (BS) in achieving a constant BV. Methods: A standard bladder phantom (133 ml) and measurements of actual urine volume were both used as benchmarks to evaluate the accuracy of the BS. Comparisons of BS with computed tomography (CT), cone-beam CT (CBCT), and an ultrasound diagnostic device (iU22) were made. Twenty-two consecutive patients with cervical cancer treated with external beam radical RT were divided into an experimental group (13 patients) and a control group (9 patients). In the experimental group, the BV was measured multiple times by BS pre-RT until it was consistent with that found by planning CT. Then a CBCT was performed. The BV was measured again immediately post-RT, after which the patient’s urine was collected and recorded. In the control group, CBCT only was performed pre-RT. Interfractional changes in BV and their impact on cervical cancer RT were investigated in both groups. The time of bladder filling was also recorded and analyzed. Results: In measuring the volume of the standard bladder phantom, the BS deviated by 1.4% in accuracy. The difference between the measurements of the BS and the iU22 had no statistical significance (linear correlation coefficient 0.96, P < 0.05). The BV measured by the BS was strongly correlated with the actual urine volume (R = 0.95, P < 0.05), planning CT (R = 0.95, P < 0.05), or CBCT (R = 0.91, P < 0.05). Compared with the BV at the time of CT, its value changed by −36.1% [1 SD (standard deviation) 42.3%; range, −79.1%–29.4%] in the control group, and 5.2% (1 SD 21.5%; range, −13.3%–22.1%) in the experimental group during treatment. The change in BV affected the target position in the superior–inferior (SI) direction

  12. Impact of electromechanical parameter variations in treatment volume doses and adjacent structures; Impacto da variacao dos parametros eletro-mecanicos nas doses do volume de tratamento e nas estruturas adjacentes

    Energy Technology Data Exchange (ETDEWEB)

    Morais, M.E.; Campos, A.M. [Instituto Nacional do Cancer (INCa), Rio de Janeiro, RJ (Brazil). Programa de Qualidade em Radioterapia]. E-mails: memorais@yahoo.com.br; amcampos@inca.gov.br; Goncalves, J. F. [Instituto de Oncologia e Radioterapia GV, Governador Valadares, MG (Brazil)]. E-mail: joelfgoncalves@yahoo.com.br; Ferreira, M.L. [Centro Radioterapico Gavea, Rio de Janeiro, RJ (Brazil)]. E-mail: mluciaf@yahoo.com

    2003-07-01

    ICRU Report 62 recommends that radiotherapy treatment dose should be prescribed in such a way that the dose to the target volume varies no more than 10%. In order to keep this goal, a very important role is played by the quality assurance (QA) of the treatment unit associated to the high level work of the personnel involved in planning and patient treatment. This paper shows the influence of the main electrical and mechanical linear accelerator parameters: field size, source-skin distance, gantry angle and light x radiation field coincidence in tumor volume and adjacent organ doses. We simulated a cubic tumor and a cubic adjacent critical organ in a cubic phantom and used a 3D Prowess system for planning. The treatment has been simulated for a 6 MV linear accelerator. We simulated two treatment planning: one using all the parameters inside their tolerance limits and another doubling these limits. The final results have show that, if the irradiation machine operates out of the tolerance limits, the dose variation in the planning target volume (PTV) can goes till {+-} 5,8% and in the critical adjacent organ till {+-} 7,7%. Therefore we concluded that, according to the complexity of the treatment, it can be necessary to reduce the tolerance levels advised by the IAEA/TECDOC - 1151. (author)

  13. A study on the variation of maxillary sinus volume and projection angle in children for CT scan

    International Nuclear Information System (INIS)

    Ji, Youn Sang; Dong, Kyung Rae; Choi, Seong Kwan; Kim, Mi Hyun; Jung, Myung Jin; Yeo, Hwa Yeon

    2017-01-01

    The Water's view is that you can examine and diagnose disease of the maxillary sinus and implemented a simple and economical because a lot of tests. Because changes in the size of the maxillary sinus and skull growth in volume, depending on the disease that occurs in children often differ from the baseline angle of the water's view that it is easy to observe. Through Computed tomography (CT) and volumetric analysis and Orbitmeatal line (OML) and Image plate (IP) is the angle and evaluate the appropriate Water's view angle in children

  14. A study on the variation of maxillary sinus volume and projection angle in children for CT scan

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Youn Sang; Dong, Kyung Rae; Choi, Seong Kwan; Kim, Mi Hyun [Radiological Technology, Gwangju Health University, Gwangju (Korea, Republic of); Jung, Myung Jin [Dept. of Radiation Science and Technology, Graduate School of Chonbuk National University, Jeonju (Korea, Republic of); Yeo, Hwa Yeon [Dept. of Radiology, Nambu University, Gwangju (Korea, Republic of)

    2017-06-15

    The Water's view is that you can examine and diagnose disease of the maxillary sinus and implemented a simple and economical because a lot of tests. Because changes in the size of the maxillary sinus and skull growth in volume, depending on the disease that occurs in children often differ from the baseline angle of the water's view that it is easy to observe. Through Computed tomography (CT) and volumetric analysis and Orbitmeatal line (OML) and Image plate (IP) is the angle and evaluate the appropriate Water's view angle in children.

  15. 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

    2014-06-28

    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.

  16. A Wireless Sensor Network Framework for Real-Time Monitoring of Height and Volume Variations on Sandy Beaches and Dunes

    Directory of Open Access Journals (Sweden)

    Alessandro Pozzebon

    2018-04-01

    Full Text Available In this paper, the authors describe the realization and testing of a Wireless Sensor Network (WSN framework aiming at measuring, remotely and in real time, the level variations of the sand layer of sandy beaches or dunes. The proposed framework is based on an innovative low cost sensing structure, able to measure the level variations with a 5-cm degree of precision and to locally transfer the acquired data through the ZigBee protocol. The described sensor is integrated in a wider ZigBee wireless sensor network architecture composed of an array of sensors that, arranged according to a grid layout, can acquire the same data at different points, allowing the definition of a dynamic map of the area under study. The WSN is connected to a local Global System for Mobile Communications (GSM gateway that is in charge of data processing and transmission to a cloud infrastructure through a General Packet Radio Service (GPRS connection. Data are then stored in a MySQL database and made available any time and anywhere through the Internet. The proposed architecture has been tested in a laboratory, to analyze data acquisition, processing timing and power consumption and then in situ to prove the effectiveness of the system. The described infrastructure is expected to be integrated in a wider IoT architecture including different typologies of sensors, in order to create a multi-purpose tool for the study of coastal erosive processes.

  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. 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.

  19. 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

  20. Variational Monte Carlo Technique

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 19; Issue 8. Variational Monte Carlo Technique: Ground State Energies of Quantum Mechanical Systems. Sukanta Deb. General Article Volume 19 Issue 8 August 2014 pp 713-739 ...

  1. Variation and decomposition of the partial molar volume of small gas molecules in different organic solvents derived from molecular dynamics simulations.

    Science.gov (United States)

    Klähn, Marco; Martin, Alistair; Cheong, Daniel W; Garland, Marc V

    2013-12-28

    The partial molar volumes, V(i), of the gas solutes H2, CO, and CO2, solvated in acetone, methanol, heptane, and diethylether are determined computationally in the limit of infinite dilution and standard conditions. Solutions are described with molecular dynamics simulations in combination with the OPLS-aa force field for solvents and customized force field for solutes. V(i) is determined with the direct method, while the composition of V(i) is studied with Kirkwood-Buff integrals (KBIs). Subsequently, the amount of unoccupied space and size of pre-formed cavities in pure solvents is determined. Additionally, the shape of individual solvent cages is analyzed. Calculated V(i) deviate only 3.4 cm(3) mol(-1) (7.1%) from experimental literature values. Experimental V(i) variations across solutions are reproduced qualitatively and also quantitatively in most cases. The KBI analysis identifies differences in solute induced solvent reorganization in the immediate vicinity of H2 (<0.7 nm) and solvent reorganization up to the third solvation shell of CO and CO2 (<1.6 nm) as the origin of V(i) variations. In all solutions, larger V(i) are found in solvents that exhibit weak internal interactions, low cohesive energy density and large compressibility. Weak internal interactions facilitate solvent displacement by thermal solute movement, which enhances the size of solvent cages and thus V(i). Additionally, attractive electrostatic interactions of CO2 and the solvents, which do not depend on internal solvent interactions only, partially reversed the V(i) trends observed in H2 and CO solutions where electrostatic interactions with the solvents are absent. More empty space and larger pre-formed cavities are found in solvents with weak internal interactions, however, no evidence is found that solutes in any considered solvent are accommodated in pre-formed cavities. Individual solvent cages are found to be elongated in the negative direction of solute movement. This wake behind

  2. Variation and decomposition of the partial molar volume of small gas molecules in different organic solvents derived from molecular dynamics simulations

    Science.gov (United States)

    Klähn, Marco; Martin, Alistair; Cheong, Daniel W.; Garland, Marc V.

    2013-12-01

    The partial molar volumes, bar V_i, of the gas solutes H2, CO, and CO2, solvated in acetone, methanol, heptane, and diethylether are determined computationally in the limit of infinite dilution and standard conditions. Solutions are described with molecular dynamics simulations in combination with the OPLS-aa force field for solvents and customized force field for solutes. bar V_i is determined with the direct method, while the composition of bar V_i is studied with Kirkwood-Buff integrals (KBIs). Subsequently, the amount of unoccupied space and size of pre-formed cavities in pure solvents is determined. Additionally, the shape of individual solvent cages is analyzed. Calculated bar V_i deviate only 3.4 cm3 mol-1 (7.1%) from experimental literature values. Experimental bar V_i variations across solutions are reproduced qualitatively and also quantitatively in most cases. The KBI analysis identifies differences in solute induced solvent reorganization in the immediate vicinity of H2 (<0.7 nm) and solvent reorganization up to the third solvation shell of CO and CO2 (<1.6 nm) as the origin of bar V_i variations. In all solutions, larger bar V_i are found in solvents that exhibit weak internal interactions, low cohesive energy density and large compressibility. Weak internal interactions facilitate solvent displacement by thermal solute movement, which enhances the size of solvent cages and thus bar V_i. Additionally, attractive electrostatic interactions of CO2 and the solvents, which do not depend on internal solvent interactions only, partially reversed the bar V_i trends observed in H2 and CO solutions where electrostatic interactions with the solvents are absent. More empty space and larger pre-formed cavities are found in solvents with weak internal interactions, however, no evidence is found that solutes in any considered solvent are accommodated in pre-formed cavities. Individual solvent cages are found to be elongated in the negative direction of solute

  3. 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.

    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

  4. 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 road users, these results show when traffic volumes alone can be a reliable proxy for exposure and when this approach is not warranted.

  5. Variation in critical care unit admission rates and outcomes for patients with acute coronary syndromes or heart failure among high- and low-volume cardiac hospitals.

    Science.gov (United States)

    van Diepen, Sean; Bakal, Jeffrey A; Lin, Meng; Kaul, Padma; McAlister, Finlay A; Ezekowitz, Justin A

    2015-02-27

    Little is known about cross-hospital differences in critical care units admission rates and related resource utilization and outcomes among patients hospitalized with acute coronary syndromes (ACS) or heart failure (HF). Using a population-based sample of 16,078 patients admitted to a critical care unit with a primary diagnosis of ACS (n=14,610) or HF (n=1467) between April 1, 2003 and March 31, 2013 in Alberta, Canada, we stratified hospitals into high (>250), medium (200 to 250), or low (<200) volume based on their annual volume of all ACS and HF hospitalization. The percentage of hospitalized patients admitted to critical care units varied across low, medium, and high-volume hospitals for both ACS and HF as follows: 77.9%, 81.3%, and 76.3% (P<0.001), and 18.0%, 16.3%, and 13.0% (P<0.001), respectively. Compared to low-volume units, critical care patients with ACS and HF admitted to high-volume hospitals had shorter mean critical care stays (56.6 versus 95.6 hours, P<0.001), more critical care procedures (1.9 versus 1.2 per patient, <0.001), and higher resource-intensive weighting (2.8 versus 1.5, P<0.001). No differences in in-hospital mortality (5.5% versus 6.2%, adjusted odds ratio 0.93; 95% CI, 0.61 to 1.41) were observed between high- and low-volume hospitals; however, 30-day cardiovascular readmissions (4.6% versus 6.8%, odds ratio 0.77; 95% CI, 0.60 to 0.99) and cardiovascular emergency-room visits (6.6% versus 9.5%, odds ratio 0.80; 95% CI, 0.69 to 0.94) were lower in high-volume compared to low-volume hospitals. Outcomes stratified by ACS or HF admission diagnosis were similar. Cardiac patients hospitalized in low-volume hospitals were more frequently admitted to critical care units and had longer hospitals stays despite lower resource-intensive weighting. These findings may provide opportunities to standardize critical care utilization for ACS and HF patients across high- and low-volume hospitals. © 2015 The Authors. Published on behalf of the American

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

    Science.gov (United States)

    Panja, Anindya Sundar; Bandopadhyay, Bidyut; Maiti, Smarajit

    2015-01-01

    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, psalt 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 (psalt-bridges and smaller volume nonpolar residues (Gly, Ala and Val) and lesser occurrence of bulky polar residues in the thermophilic proteins. A more stoichiometric relationship amongst these factors minimized the hindrance due to side chain burial and increased compactness and secondary structural stability in thermophilic proteins.

  7. The Partial Molar Volume and Compressibility of FeO in CaO-SiO2 Liquids: Systematic Variation with Fe2+ Coordination Change

    Science.gov (United States)

    Guo, X.; Lange, R. A.; Ai, Y.

    2009-12-01

    Iron is an important element in magmatic liquid, since its concentration can range up to 18% in some basaltic liquids, and it has two oxidation states. In order to model magmatic processes, thermodynamic descriptions of silicate melts must include precise information for both the FeO and Fe2O3 components. Currently, the partial molar volume of FeO is not as well known as that for Fe2O3 because of the difficulty of performing double-bob density measurements under reducing conditions. Yet these data are required in order to convert sound speed measurements on FeO-bearing liquids into compressibility data, which in turn are needed extend density models for magmatic liquids to elevated pressures. Moreover, there is growing evidence from the spectroscopic literature that Fe2+ occurs in 4, 5, and 6-fold coordination in silicate melts, and thus it is possible that the partial molar volume and compressibility of FeO may vary with Fe2+ coordination, and thus with melt composition. To explore these issues, we have conducted both density and relaxed sound speed measurements on liquids in the CaO-FeO-SiO2 system, where the CaO/SiO2 ratio was systematically varied at constant FeO concentration (40 mol%). Density was measured between 1594 and 1813K with the double-bob Archimedean method using molybdenum bobs and crucible in a reducing gas (1%CO-99%Ar) environment. The sounds speeds were measured under similar conditions with a frequency-sweep acoustic interferometer. The derived partial molar volume of FeO increases systematically from 13.7 to 15.2 cm3/mol at 1673 K as the CaO/SiO2 ratio increases and the Fe2+ coordination number decreases. From a comparison with the crystalline volume of FeO (halite structure; 12.06 cm3/mol), which serves as a lower limit for VFeO in silicate liquids when Fe2+ is in 6-fold coordination, we estimate that the average Fe2+ coordination in our experimental melts extends up to values between 5 and 4, consistent with the spectroscopic literature. The

  8. 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.

  9. Identification of the State of Maximal Hyperemia in the Assessment of Coronary Fractional Flow Reserve Using Non-Invasive Electrical Velocimetry.

    Science.gov (United States)

    Murasawa, Takahide; Takahashi, Masao; Myojo, Masahiro; Kiyosue, Arihiro; Oguri, Atsushi; Ando, Jiro; Komuro, Issei

    2017-05-31

    Previous research revealed that, in patients with coronary pressure-derived fractional flow reserve (FFR) in the 'grey zone' (0.75-0.85), repeated FFR assessments sometimes yield conflicting results. One of the causes of the fluctuations in FFR values around the grey zone may be imprecise identification of the point where maximal hyperemia is achieved. Identification of the state of maximal hyperemia during assessment of FFR can be challenging. This study aimed to determine whether non-invasive electrical velocimetry (EV) can be used to identify the state of maximal hyperemia.Stroke volume (SV), SV variation (SVV), and systemic vascular resistance index (SVRI) were determined by EV in 15 patients who underwent FFR assessment. Time intervals from initiation of adenosine infusion to achieving maximal hyperemia (time mFRR ), as well as to achieving maximal cardiac output (CO), SV, SVV, and SVRI (time mCO , time mSV , time mSVV , and time mSVRI , respectively), were determined. Time mCO and time mSVV were closer to time mFRR than other values (time mSVV /time mFRR versus time mSVRI /time mFRR = 1.03 ± 0.2 versus 1.36 ± 0.4, P state of maximal hyperemia.

  10. Persistently better treatment planning results of intensity-modulated (IMRT) over conformal radiotherapy (3D-CRT) in prostate cancer patients with significant variation of clinical target volume and/or organs-at-risk

    International Nuclear Information System (INIS)

    Fenoglietto, Pascal; Laliberte, Benoit; Allaw, Ali; Ailleres, Norbert; Idri, Katia; Hay, Meng Huor; Moscardo, Carmen Llacer; Gourgou, Sophie; Dubois, Jean-Bernard; Azria, David

    2008-01-01

    Purpose: To compare the dose coverage of planning and clinical target volume (PTV, CTV), and organs-at-risk (OAR) between intensity-modulated (3D-IMRT) and conventional conformal radiotherapy (3D-CRT) before and after internal organ variation in prostate cancer. Methods and materials: We selected 10 patients with clinically significant interfraction volume changes. Patients were treated with 3D-IMRT to 80 Gy (minimum PTV dose of 76 Gy, excluding rectum). Fictitious, equivalent 3D-CRT plans (80 Gy at isocenter, with 95% isodose (76 Gy) coverage of PTV, with rectal blocking above 76 Gy) were generated using the same planning CT data set ('CT planning'). The plans were then also applied to a verification CT scan ('CT verify') obtained at a different moment. PTV, CTV, and OAR dose coverage were compared using non-parametric tests statistics for V95, V90 (% of the volume receiving ≥95 or 90% of the dose) and D50 (dose to 50% of the volume). Results: Mean V95 of the PTV for 'CT planning' was 94.3% (range, 88-99) vs 89.1% (range, 84-94.5) for 3D-IMRT and 3D-CRT (p = 0.005), respectively. Mean V95 of the CTV for 'CT verify' was 97% for both 3D-IMRT and 3D-CRT. Mean D50 of the rectum for 'CT planning' was 26.8 Gy (range, 22-35) vs 43.5 Gy (range, 33.5-50.5) for 3D-IMRT and 3D-CRT (p = 0.0002), respectively. For 'CT verify', this D50 was 31.1 Gy (range, 16.5-44) vs 44.2 Gy (range, 34-55) for 3D-IMRT and 3D-CRT (p = 0.006), respectively. V95 of the rectum was 0% for both plans for 'CT planning', and 2.3% (3D-IMRT) vs 2.1% (3D-CRT) for 'CT verify' (p = non-sig.). Conclusion: Dose coverage of the PTV and OAR was better with 3D-IMRT for each patient and remained so after internal volume changes

  11. 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…

  12. Evaluation of volume compressibility coefficient variations incement ...

    African Journals Online (AJOL)

    In this study, 2,4,6,8 and 10% of cement at treatment times of 7,14 and 28 days were used to stabilize the bentonite clay. All samples prepared by wet and dry method hadthe same moisture contents in the mentioned levels equal to the liquid limit moisture of the original soil. The studied soil falls in the group CH with the ...

  13. 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 standard deviations of the log proportional errors for 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.

  14. Ovarian volume throughout life

    DEFF Research Database (Denmark)

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

    2013-01-01

    conception to 82 years of age. This model shows that 69% of the variation in ovarian volume is due to age alone. We have shown that in the average case ovarian volume rises from 0.7 mL (95% CI 0.4-1.1 mL) at 2 years of age to a peak of 7.7 mL (95% CI 6.5-9.2 mL) at 20 years of age with a subsequent decline...... 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......The measurement of ovarian volume has been shown to be a useful indirect indicator of the ovarian reserve in women of reproductive age, in the diagnosis and management of a number of disorders of puberty and adult reproductive function, and is under investigation as a screening tool for ovarian...

  15. 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

  16. Evolutionary significance of epigenetic variation

    NARCIS (Netherlands)

    Richards, C.L.; Verhoeven, K.J.F.; Bossdorf, O.; Wendel, J.F.; Greilhuber, J.; Dolezel, J.; Leitch, I.J.

    2012-01-01

    Several chapters in this volume demonstrate how epigenetic work at the molecular level over the last few decades has revolutionized our understanding of genome function and developmental biology. However, epigenetic processes not only further our understanding of variation and regulation at the

  17. 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...

  18. 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 standard deviation: CECT versus PET/CT 32.48 cm(3) ± 36.63 versus 32.21 cm(3) ± 37.09; 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

  19. Metaleptic Variations

    OpenAIRE

    Pernot, Dominique

    2014-01-01

    Les derniers romans de Gabriel Josipovici offrent beaucoup de variété, allant de la parodie, de la fiction comique légère, dans Only Joking et Making Mistakes, à des sujets plus graves, plus personnels, ontologiques. Dans un court roman, Everything Passes, et dans un roman majeur, Goldberg: Variations, le lecteur est amené à se poser des questions sur la nature mystérieuse de la réalité, qui est, trop souvent, acceptée sans conteste par de nombreux roma...

  20. 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...... the study on four video-recorded sessions, with four different PhD students and their supervisors, all from life sciences. Our analysis revealed that learning opportunities in the supervision sessions concerned either the content matter of research (for instance, understanding soil structure......), or the research methods— more specifically how to produce valid results. Our results illustrate how supervisors and PhD students create a space of learning together in their particular discipline by varying critical aspects of their research in their discussions. Situations where more openended research issues...

  1. 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.

  2. 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.

  3. Bladder filling variation during conformal radiotherapy for rectal cancer

    International Nuclear Information System (INIS)

    Sithamparam, S; Ahmad, R; Sabarudin, A; Othman, Z; Ismail, M

    2017-01-01

    Conformal radiotherapy for rectal cancer is associated with small bowel toxicity mainly diarrhea. Treating patients with a full bladder is one of the practical solutions to reduce small bowel toxicity. Previous studies on prostate and cervix cancer patients revealed that maintaining consistent bladder volume throughout radiotherapy treatment is challenging. The aim of this study was to measure bladder volume variation throughout radiotherapy treatment. This study also measured the association between bladder volume changes and diarrhea. Twenty two rectal cancer patients were recruited prospectively. Patients were planned for treatment with full bladder following departmental bladder filling protocol and the planning bladder volume was measured during CT-simulation. During radiotherapy, the bladder volume was measured weekly using cone-beam computed tomography (CBCT) and compared to planning bladder volume. Incidence and severity of diarrhea were recorded during the weekly patient review. There was a negative time trend for bladder volume throughout five weeks treatment. The mean bladder volume decreased 18 % from 123 mL (SD 54 mL) during CT-simulation to 101 mL (SD 71 mL) on the 5th week of radiotherapy, but the decrease is not statistically significant. However, there was a large variation of bladder volume within each patient during treatment. This study showed an association between changes of bladder volume and diarrhea (P = 0.045). In conclusion bladder volume reduced throughout radiotherapy treatment for conformal radiotherapy for rectal cancer and there was a large variation of bladder volume within patients. (paper)

  4. Bladder filling variation during conformal radiotherapy for rectal cancer

    Science.gov (United States)

    Sithamparam, S.; Ahmad, R.; Sabarudin, A.; Othman, Z.; Ismail, M.

    2017-05-01

    Conformal radiotherapy for rectal cancer is associated with small bowel toxicity mainly diarrhea. Treating patients with a full bladder is one of the practical solutions to reduce small bowel toxicity. Previous studies on prostate and cervix cancer patients revealed that maintaining consistent bladder volume throughout radiotherapy treatment is challenging. The aim of this study was to measure bladder volume variation throughout radiotherapy treatment. This study also measured the association between bladder volume changes and diarrhea. Twenty two rectal cancer patients were recruited prospectively. Patients were planned for treatment with full bladder following departmental bladder filling protocol and the planning bladder volume was measured during CT-simulation. During radiotherapy, the bladder volume was measured weekly using cone-beam computed tomography (CBCT) and compared to planning bladder volume. Incidence and severity of diarrhea were recorded during the weekly patient review. There was a negative time trend for bladder volume throughout five weeks treatment. The mean bladder volume decreased 18 % from 123 mL (SD 54 mL) during CT-simulation to 101 mL (SD 71 mL) on the 5th week of radiotherapy, but the decrease is not statistically significant. However, there was a large variation of bladder volume within each patient during treatment. This study showed an association between changes of bladder volume and diarrhea (P = 0.045). In conclusion bladder volume reduced throughout radiotherapy treatment for conformal radiotherapy for rectal cancer and there was a large variation of bladder volume within patients.

  5. Prostate Contouring Variation: Can It Be Fixed?

    International Nuclear Information System (INIS)

    Khoo, Eric L.H.; Schick, Karlissa; Plank, Ashley W.; Poulsen, Michael; Wong, Winnie W.G.; Middleton, Mark; Martin, Jarad M.

    2012-01-01

    Purpose: To assess whether an education program on CT and MRI prostate anatomy would reduce inter- and intraobserver prostate contouring variation among experienced radiation oncologists. Methods and Materials: Three patient CT and MRI datasets were selected. Five radiation oncologists contoured the prostate for each patient on CT first, then MRI, and again between 2 and 4 weeks later. Three education sessions were then conducted. The same contouring process was then repeated with the same datasets and oncologists. The observer variation was assessed according to changes in the ratio of the encompassing volume to intersecting volume (volume ratio [VR]), across sets of target volumes. Results: For interobserver variation, there was a 15% reduction in mean VR with CT, from 2.74 to 2.33, and a 40% reduction in mean VR with MRI, from 2.38 to 1.41 after education. A similar trend was found for intraobserver variation, with a mean VR reduction for CT and MRI of 9% (from 1.51 to 1.38) and 16% (from 1.37 to 1.15), respectively. Conclusion: A well-structured education program has reduced both inter- and intraobserver prostate contouring variations. The impact was greater on MRI than on CT. With the ongoing incorporation of new technologies into routine practice, education programs for target contouring should be incorporated as part of the continuing medical education of radiation oncologists.

  6. Seasonal variation in sports participation.

    Science.gov (United States)

    Schüttoff, Ute; Pawlowski, Tim

    2018-02-01

    This study explores indicators describing socio-demographics, sports participation characteristics and motives which are associated with variation in sports participation across seasons. Data were drawn from the German Socio-Economic Panel which contains detailed information on the sports behaviour of adults in Germany. Overall, two different measures of seasonal variation are developed and used as dependent variables in our regression models. The first variable measures the coefficient of (seasonal) variation in sport-related energy expenditure per week. The second variable measures whether activity drops below the threshold as defined by the World Health Organization (WHO). Results suggest that the organisational setting, the intensity and number of sports practised, and the motive for participation are strongly correlated with the variation measures used. For example, both, participation in a sports club and a commercial facility, are associated with reduced seasonal variation and a significantly higher probability of participating at a volume above the WHO threshold across all seasons. These findings give some impetus for policymaking and the planning of sports programmes as well as future research directions.

  7. Variational principles for locally variational forms

    International Nuclear Information System (INIS)

    Brajercik, J.; Krupka, D.

    2005-01-01

    We present the theory of higher order local variational principles in fibered manifolds, in which the fundamental global concept is a locally variational dynamical form. Any two Lepage forms, defining a local variational principle for this form, differ on intersection of their domains, by a variationally trivial form. In this sense, but in a different geometric setting, the local variational principles satisfy analogous properties as the variational functionals of the Chern-Simons type. The resulting theory of extremals and symmetries extends the first order theories of the Lagrange-Souriau form, presented by Grigore and Popp, and closed equivalents of the first order Euler-Lagrange forms of Hakova and Krupkova. Conceptually, our approach differs from Prieto, who uses the Poincare-Cartan forms, which do not have higher order global analogues

  8. 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.

  9. All rights reserved Variation in Body Weight, Organ Weight and ...

    African Journals Online (AJOL)

    ADOWIE PERE

    Variation in Body Weight, Organ Weight and Haematological Parameters of Rats Fed ... ABSTRACT: Food insecurity is a major problem of the developing nations. ... Except for the values of haemoglobin and packed cell volume that were ...

  10. Variation and Mathematics Pedagogy

    Science.gov (United States)

    Leung, Allen

    2012-01-01

    This discussion paper put forwards variation as a theme to structure mathematical experience and mathematics pedagogy. Patterns of variation from Marton's Theory of Variation are understood and developed as types of variation interaction that enhance mathematical understanding. An idea of a discernment unit comprising mutually supporting variation…

  11. 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

  12. Volume variation of Gruneisen parameters of fcc transition metals

    Indian Academy of Sciences (India)

    Unknown

    average discrepancy between the values of γ measured by various methods for 23 metals. Experimentally only the total Gruneisen parameter can be measured. The total. Gruneisen parameter is the sum of lattice, electronic and probably magnetic contribution. The letter term is present in palladium (White and Pawlok 1970) ...

  13. Southern Alaska Glaciers: Spatial and Temporal Variations in Ice Volume

    Science.gov (United States)

    Sauber, J.; Molnia, B. F.; Lutchke, S.; Rowlands, D.; Harding, D.; Carabajal, C.; Hurtado, J. M.; Spade, G.

    2004-01-01

    Although temperate mountain glaciers comprise less than 1% of the glacier-covered area on Earth, they are important because they appear to be melting rapidly under present climatic conditions and, therefore, make significant contributions to rising sea level. In this study, we use ICESat observations made in the last 1.5 years of southern Alaska glaciers to estimate ice elevation profiles, ice surface slopes and roughness, and bi-annual and/or annual ice elevation changes. We report initial results from the near coastal region between Yakutat Bay and Cape Suckling that includes the Malaspina and Bering Glaciers. We show and interpret ice elevations changes across the lower reaches of the Bagley Ice Valley for the period between October 2003 and May 2004. In addition, we use off-nadir pointing observations to reference tracks over the Bering and Malaspina Glaciers in order to estimate annual ice elevation change. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and Shuttle Radar Topography Mission (SRTM) derived DEMs are used to estimate across track regional slopes between ICESat data acquisitions. Although the distribution and quantity of ICESat elevation profiles with multiple, exact repeat data is currently limited in Alaska, individual ICESat data tracks, provide an accurate reference surface for comparison to other elevation data (e.g. ASTER and SRTM X- and C-band derived DEMs). Specifically we report the elevation change over the Malaspina Glacier's piedmont lobe between a DEM derived from SRTM C-band data acquired in Feb. 2000 and ICESat Laser #2b data from Feb.-March 2004. We also report use of ICESat elevation data to enhance ASTER derived absolute DEMs. Mountain glaciers generally have rougher surfaces and steeper regional slopes than the ice sheets for which the ICESat design was optimized. Therefore, rather than averaging ICESat observations over large regions or relying on crossovers, we are working with well-located ICESat footprint returns to estimate glacier ice elevations and surface characteristics. Additional information is included in the original extended abstract.

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

    African Journals Online (AJOL)

    user

    2010-11-11

    Nov 11, 2010 ... to the soil mineral nutrient composition of which variants are referred to as ... primary radiation, is used to cause ejection of an electron from the inner shells of an atom. ... The elements in the sample can therefore be identified.

  15. Towards a genetic architecture of cryptic genetic variation

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Genetics; Volume 84; Issue 3. Towards a genetic architecture of cryptic genetic variation and genetic assimilation: the contribution of K. G. Bateman. Ian Dworkin. Commentary on J. Genet. Classic Volume 84 Issue 3 December 2005 pp 223-226 ...

  16. 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

  17. Calculus of variations

    CERN Document Server

    Elsgolc, Lev D

    2007-01-01

    This concise text offers both professionals and students an introduction to the fundamentals and standard methods of the calculus of variations. In addition to surveys of problems with fixed and movable boundaries, it explores highly practical direct methods for the solution of variational problems.Topics include the method of variation in problems with fixed boundaries; variational problems with movable boundaries and other problems; sufficiency conditions for an extremum; variational problems of constrained extrema; and direct methods of solving variational problems. Each chapter features nu

  18. Specification of volume and dose in radiotherapy

    International Nuclear Information System (INIS)

    Levernes, S.

    1997-01-01

    As a result of a questionnaire about dose and volume specifications in radiotherapy in the Nordic countries, a group has been set up to propose common recommendations for these countries. The proposal is partly based on ICRU 50, but with major extensions. These extensions fall into three areas: patient geometry, treatment geometry, and dose specifications. For patient geometry and set-up one need alignment markings and anatomical reference points, the latter can be divided into internal and external reference points. These points are necessary to get relationships between coordinate systems related to patient and to treatment unit. For treatment geometry the main volume will be an anatomical target volume which just encompass the clinical target volume with all its variations and movements. This anatomical volume are the most suitable volume for prescription, optimization and reporting dose. A set-up margin should be added to the beam periphery in beams-eye-view to get the minimum size and shape of the beam. For dose specification the most important parameter for homogeneous dose distributions is the arithmetic mean of dose to the anatomical target volume together with its standard deviation. In addition the dose to the ICRU reference point should be reported for intercomparison, together with minimum and maximum doses or dose volume histograms for the anatomical target volume. (author)

  19. Quantum Variational Calculus

    OpenAIRE

    Malinowska , Agnieszka B.; Torres , Delfim

    2014-01-01

    International audience; Introduces readers to the treatment of the calculus of variations with q-differences and Hahn difference operators Provides the reader with the first extended treatment of quantum variational calculus Shows how the techniques described can be applied to economic models as well as other mathematical systems This Brief puts together two subjects, quantum and variational calculi by considering variational problems involving Hahn quantum operators. The main advantage of it...

  20. Bilateral renal artery variation

    OpenAIRE

    Üçerler, Hülya; Üzüm, Yusuf; İkiz, Z. Aslı Aktan

    2014-01-01

    Each kidney is supplied by a single renal artery, although renal artery variations are common. Variations of the renal arteryhave become important with the increasing number of renal transplantations. Numerous studies describe variations in renalartery anatomy. Especially the left renal artery is among the most critical arterial variations, because it is the referred side forresecting the donor kidney. During routine dissection in a formalin fixed male cadaver, we have found a bilateral renal...

  1. Genetics and variation

    Science.gov (United States)

    John R. Jones; Norbert V. DeByle

    1985-01-01

    The broad genotypic variability in quaking aspen (Populus tremuloides Michx.), that results in equally broad phenotypic variability among clones is important to the ecology and management of this species. This chapter considers principles of aspen genetics and variation, variation in aspen over its range, and local variation among clones. For a more...

  2. 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

  3. General volumes in the Orlicz-Brunn-Minkowski theory and a related Minkowski Problem I

    OpenAIRE

    Gardner, Richard J.; Hug, Daniel; Weil, Wolfgang; Xing, Sudan; Ye, Deping

    2018-01-01

    The general volume of a star body, a notion that includes the usual volume, the $q$th dual volumes, and many previous types of dual mixed volumes, is introduced. A corresponding new general dual Orlicz curvature measure is defined that specializes to the $(p,q)$-dual curvature measures introduced recently by Lutwak, Yang, and Zhang. General variational formulas are established for the general volume of two types of Orlicz linear combinations. One of these is applied to the Minkowski problem f...

  4. 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...

  5. Blood volume studies

    International Nuclear Information System (INIS)

    Lewis, S.M.; Yin, J.A.L.

    1986-01-01

    The use of dilution analysis with such radioisotopes as 51 Cr, 32 P, sup(99m)Tc and sup(113m)In for measuring red cell volume is reviewed briefly. The use of 125 I and 131 I for plasma volume studies is also considered and the subsequent determination of total blood volume discussed, together with the role of the splenic red cell volume. Substantial bibliography. (UK)

  6. Partial Molar Volumes of Aqua Ions from First Principles.

    Science.gov (United States)

    Wiktor, Julia; Bruneval, Fabien; Pasquarello, Alfredo

    2017-08-08

    Partial molar volumes of ions in water solution are calculated through pressures obtained from ab initio molecular dynamics simulations. The correct definition of pressure in charged systems subject to periodic boundary conditions requires access to the variation of the electrostatic potential upon a change of volume. We develop a scheme for calculating such a variation in liquid systems by setting up an interface between regions of different density. This also allows us to determine the absolute deformation potentials for the band edges of liquid water. With the properly defined pressures, we obtain partial molar volumes of a series of aqua ions in very good agreement with experimental values.

  7. Anatomic variation of cranial parasympathetic ganglia

    Directory of Open Access Journals (Sweden)

    Selma Siéssere

    2008-06-01

    Full Text Available Having broad knowledge of anatomy is essential for practicing dentistry. Certain anatomical structures call for detailed studies due to their anatomical and functional importance. Nevertheless, some structures are difficult to visualize and identify due to their small volume and complicated access. Such is the case of the parasympathetic ganglia located in the cranial part of the autonomic nervous system, which include: the ciliary ganglion (located deeply in the orbit, laterally to the optic nerve, the pterygopalatine ganglion (located in the pterygopalatine fossa, the submandibular ganglion (located laterally to the hyoglossus muscle, below the lingual nerve, and the otic ganglion (located medially to the mandibular nerve, right beneath the oval foramen. The aim of this study was to present these structures in dissected anatomic specimens and perform a comparative analysis regarding location and morphology. The proximity of the ganglia and associated nerves were also analyzed, as well as the number and volume of fibers connected to them. Human heads were dissected by planes, partially removing the adjacent structures to the point we could reach the parasympathetic ganglia. With this study, we concluded that there was no significant variation regarding the location of the studied ganglia. Morphologically, our observations concur with previous classical descriptions of the parasympathetic ganglia, but we observed variations regarding the proximity of the otic ganglion to the mandibular nerve. We also observed that there were variations regarding the number and volume of fiber bundles connected to the submandibular, otic, and pterygopalatine ganglia.

  8. A variational principle for the plasma centrifuge

    International Nuclear Information System (INIS)

    Ludwig, G.O.

    1986-09-01

    A variational principle is derived which describes the stationary state of the plasma column in a plasma centrifuge. Starting with the fluid equations in a rotating frame the theory is developed using the method of irreversible thermodynamics. This formulation easily leads to an expression for the density distribution of the l-species at sedimentation equilibrium, taking into account the effect of the electric and magnetic forces. Assuming stationary boundary conditions and rigid rotation nonequilibrium states the condition for thermodynamic stability integrated over the volume of the system reduces, under certain restrictions, to the principle of minimum entropy production in the stationary state. This principle yields a variational problem which is equivalent to the original problem posed by the stationary fluid equations. The variational method is useful in achieving approximate solutions that give the electric potential and current distributions in the rotating plasma column consistent with an assumed plasma density profile. (Author) [pt

  9. 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.

  10. Sensitivity of the amplitude of the single muscle fibre action potential to microscopic volume conduction parameters

    NARCIS (Netherlands)

    Alberts, B.A.; Rutten, Wim; Wallinga, W.; Boom, H.B.K.

    1988-01-01

    A microscopic model of volume conduction was applied to examine the sensitivity of the single muscle fibre action potential to variations in parameters of the source and of the volume conductor, such as conduction velocity, intracellular conductivity and intracellular volume fraction. The model

  11. 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.

  12. Volume regulation in epithelia

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Hoffmann, Else Kay

    2016-01-01

    to amphibian skin and mammalian cortical collecting tubule of low and intermediate osmotic permeability. Crosstalk between entrance and exit mechanisms interferes with volume regulation both at aniso-osmotic and iso-osmotic volume perturbations. It has been proposed that cell volume regulation is an intrinsic...... 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...... volume regulation. In the same cell, these functions may be maintained by different ion pathways that are separately regulated. RVD is often preceded by increase in cytosolic free Ca2+, probably via influx through TRP channels, but Ca2+ release from intracellular stores has also been observed. Cell...

  13. Quantum variational calculus

    CERN Document Server

    Malinowska, Agnieszka B

    2014-01-01

    This Brief puts together two subjects, quantum and variational calculi by considering variational problems involving Hahn quantum operators. The main advantage of its results is that they are able to deal with nondifferentiable (even discontinuous) functions, which are important in applications. Possible applications in economics are discussed. Economists model time as continuous or discrete. Although individual economic decisions are generally made at discrete time intervals, they may well be less than perfectly synchronized in ways discrete models postulate. On the other hand, the usual assumption that economic activity takes place continuously, is nothing else than a convenient abstraction that in many applications is far from reality. The Hahn quantum calculus helps to bridge the gap between the two families of models: continuous and discrete. Quantum Variational Calculus is self-contained and unified in presentation. It provides an opportunity for an introduction to the quantum calculus of variations fo...

  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. General quantum variational calculus

    Directory of Open Access Journals (Sweden)

    Artur M. C. Brito da Cruz

    2018-02-01

    Full Text Available We develop a new variational calculus based in the general quantum difference operator recently introduced by Hamza et al. In particular, we obtain optimality conditions for generalized variational problems where the Lagrangian may depend on the endpoints conditions and a real parameter, for the basic and isoperimetric problems, with and without fixed boundary conditions. Our results provide a generalization to previous results obtained for the $q$- and Hahn-calculus.

  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. Dynamic Variables Fail to Predict Fluid Responsiveness in an Animal Model With Pericardial Effusion.

    Science.gov (United States)

    Broch, Ole; Renner, Jochen; Meybohm, Patrick; Albrecht, Martin; Höcker, Jan; Haneya, Assad; Steinfath, Markus; Bein, Berthold; Gruenewald, Matthias

    2016-10-01

    The reliability of dynamic and volumetric variables of fluid responsiveness in the presence of pericardial effusion is still elusive. The aim of the present study was to investigate their predictive power in a porcine model with hemodynamic relevant pericardial effusion. A single-center animal investigation. Twelve German domestic pigs. Pigs were studied before and during pericardial effusion. Instrumentation included a pulmonary artery catheter and a transpulmonary thermodilution catheter in the femoral artery. Hemodynamic variables like cardiac output (COPAC) and stroke volume (SVPAC) derived from pulmonary artery catheter, global end-diastolic volume (GEDV), stroke volume variation (SVV), and pulse-pressure variation (PPV) were obtained. At baseline, SVV, PPV, GEDV, COPAC, and SVPAC reliably predicted fluid responsiveness (area under the curve 0.81 [p = 0.02], 0.82 [p = 0.02], 0.74 [p = 0.07], 0.74 [p = 0.07], 0.82 [p = 0.02]). After establishment of pericardial effusion the predictive power of dynamic variables was impaired and only COPAC and SVPAC and GEDV allowed significant prediction of fluid responsiveness (area under the curve 0.77 [p = 0.04], 0.76 [p = 0.05], 0.83 [p = 0.01]) with clinically relevant changes in threshold values. In this porcine model, hemodynamic relevant pericardial effusion abolished the ability of dynamic variables to predict fluid responsiveness. COPAC, SVPAC, and GEDV enabled prediction, but their threshold values were significantly changed. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Variable volume combustor

    Science.gov (United States)

    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.

  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 determin...

  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. 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....

  2. Variation, structure and norms

    DEFF Research Database (Denmark)

    Harder, Peter

    2014-01-01

    in linguistics: those that see linguistic norms as antithetical to a descriptive and variational linguistics. Once such a re-evaluation has taken place, however, the social recontextualization of cognition will enable linguistics (including sociolinguistics as an integral part), to eliminate the cracks...... that an evolutionary account can reintegrate the opposed fragments into a whole picture that puts each of them in their ‘ecological position’ with respect to each other. Empirical usage facts should be seen in the context of operational norms in relation to which actual linguistic choices represent adaptations....... Variational patterns should be seen in the context of structural categories without which there would be only ‘differences’ rather than variation. And emergence, individual choice, and flux should be seen in the context of the individual’s dependence on lineages of community practice sustained by collective...

  3. Ladder variational autoencoders

    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...... Variational Autoencoder, that recursively corrects the generative distribution by a data dependent approximate likelihood in a process resembling the recently proposed Ladder Network. We show that this model provides state of the art predictive log-likelihood and tighter log-likelihood lower bound compared...

  4. 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...... Variational Autoencoder, that recursively corrects the generative distribution by a data dependent approximate likelihood in a process resembling the recently proposed Ladder Network. We show that this model provides state of the art predictive log-likelihood and tighter log-likelihood lower bound compared...

  5. 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

  6. Cosmological constants and variations

    International Nuclear Information System (INIS)

    Barrow, John D

    2005-01-01

    We review properties of theories for the variation of the gravitation and fine structure 'constants'. We highlight some general features of the cosmological models that exist in these theories with reference to recent quasar data that is consistent with time-variation in the fine structure 'constant' since a redshift of 3.5. The behaviour of a simple class of varying alpha cosmologies is outlined in the light of all the observational constraints. We also discuss some of the consequences of varying 'constants' for oscillating universes and show by means of exact solutions that they appear to evolve monotonically in time even though the scale factor of the universe oscillates

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

    KAUST Repository

    Sicat, Ronell Barrera; Kruger, Jens; Moller, Torsten; Hadwiger, Markus

    2014-01-01

    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

  8. Volume-based characterization of postocclusion surge.

    Science.gov (United States)

    Zacharias, Jaime; Zacharias, Sergio

    2005-10-01

    To propose an alternative method to characterize postocclusion surge using a collapsible artificial anterior chamber to replace the currently used rigid anterior chamber model. Fundación Oftamológica Los Andes, Santiago, Chile. The distal end of a phacoemulsification handpiece was placed inside a compliant artificial anterior chamber. Digital recordings of chamber pressure, chamber volume, inflow, and outflow were performed during occlusion break of the phacoemulsification tip. The occlusion break profile of 2 different consoles was compared. Occlusion break while using a rigid anterior chamber model produced a simultaneous increase of chamber inflow and outflow. In the rigid chamber model, pressure decreased sharply, reaching negative pressure values. Alternatively, with the collapsible chamber model, a delay was observed in the inflow that occurs to compensate the outflow surge. Also, the chamber pressure drop was smaller in magnitude, never undershooting below atmospheric pressure into negative values. Using 500 mm Hg as vacuum limit, the Infiniti System (Alcon) performed better that the Legacy (Alcon), showing an 18% reduction in peak volume variation. The collapsible anterior chamber model provides a more realistic representation of the postocclusion surge events that occur in the real eye during cataract surgery. Peak volume fluctuation (mL), half volume recovery time(s), and volume fluctuation integral value (mL x s) are proposed as realistic indicators to characterize the postocclusion surge performance. These indicators show that the Infiniti System has a better postocclusion surge behavior than the Legacy System.

  9. On exterior variational calculus

    International Nuclear Information System (INIS)

    Aldrovandi, R.; Kraenkel, R.A.

    1987-01-01

    Exterior variational calculus is introduced through examples in field theory. It provides a very simple technique to decide on the existence of Lagrangians for given equations of motions and, in the case, to find them. Only local aspects are discussed but the analogy to exterior calculus on finite dimensional manifolds is complete, strongly suggesting its suitability to the study of topological aspects. (Author) [pt

  10. Variational transition state theory

    International Nuclear Information System (INIS)

    Truhlar, D.G.

    1986-01-01

    This project is concerned with the development and applications of generalized transition state theory and multidimensional tunneling approximations to chemical reaction rates. They have developed and implemented several practical versions of variational transition state theory (VTST), namely canonical variational theory (CVT), improved canonical variational theory (ICVT), and microcanonical variational theory (μVT). They have also developed and implemented several accurate multidimensional semiclassical tunneling approximations, the most accurate of which are the small-curvature semiclassical adiabatic (SCSA), large-curvature version-3 (LC3), and least-action (LA) approximations. They have applied the methods to thermal rate constants, using transmission coefficients based on ground-state tunneling, and they have also presented and applied adiabatic and diabatic extensions to calculated rate constants for vibrationally excited reactants. Their general goal is to develop accurate methods for calculating chemical reaction rate constants that remain practical even for reasonably complicated molecules. The approximations mentioned above yield rate constants for systems whose potential energy surface is known or assumed. Thus a second, equally important aspect of their work is the determination or modeling, semi-empirically and/or from electronic structure calculations, of potential energy surfaces

  11. Variation in decision making

    NARCIS (Netherlands)

    Dall, Sasha R. X.; Gosling, Samuel; Gordon D.A., Brown,; Dingemanse, Niels; Ido, Erev,; Martin, Kocher,; Laura, Schulz,; Todd, Peter M; Weissing, Franz; Wolf, Max; Hammerstein, Peter; Stevens, Jeffrey R.

    2012-01-01

    Variation in how organisms allocate their behavior over their lifetimes is key to determining Darwinian fitness., and thus the evolution of human and nonhuman decision making. This chapter explores how decision making varies across biologically and societally significant scales and what role such

  12. 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…

  13. The variational spiked oscillator

    International Nuclear Information System (INIS)

    Aguilera-Navarro, V.C.; Ullah, N.

    1992-08-01

    A variational analysis of the spiked harmonic oscillator Hamiltonian -d 2 / d x 2 + x 2 + δ/ x 5/2 , δ > 0, is reported in this work. A trial function satisfying Dirichlet boundary conditions is suggested. The results are excellent for a large range of values of the coupling parameter. (author)

  14. 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.

  15. The nonholonomic variational principle

    Energy Technology Data Exchange (ETDEWEB)

    Krupkova, Olga [Department of Algebra and Geometry, Faculty of Science, Palacky University, Tomkova 40, 779 00 Olomouc (Czech Republic); Department of Mathematics, La Trobe University, Bundoora, Victoria 3086 (Australia)], E-mail: krupkova@inf.upol.cz

    2009-05-08

    A variational principle for mechanical systems and fields subject to nonholonomic constraints is found, providing Chetaev-reduced equations as equations for extremals. Investigating nonholonomic variations of the Chetaev type and their properties, we develop foundations of the calculus of variations on constraint manifolds, modelled as fibred submanifolds in jet bundles. This setting is appropriate to study general first-order 'nonlinear nonitegrable constraints' that locally are given by a system of first-order ordinary or partial differential equations. We obtain an invariant constrained first variation formula and constrained Euler-Lagrange equations both in intrinsic and coordinate forms, and show that the equations are the same as Chetaev equations 'without Lagrange multipliers', introduced recently by other methods. We pay attention to two possible settings: first, when the constrained system arises from an unconstrained Lagrangian system defined in a neighbourhood of the constraint, and second, more generally, when an 'internal' constrained system on the constraint manifold is given. In the latter case a corresponding unconstrained system need not be a Lagrangian, nor even exist. We also study in detail an important particular case: nonholonomic constraints that can be alternatively modelled by means of (co)distributions in the total space of the fibred manifold; in nonholonomic mechanics this happens whenever constraints affine in velocities are considered. It becomes clear that (and why) if the distribution is completely integrable (= the constraints are semiholonomic), the principle of virtual displacements holds and can be used to obtain the constrained first variational formula by a more or less standard procedure, traditionally used when unconstrained or holonomic systems are concerned. If, however, the constraint is nonintegrable, no significant simplifications are available. Among others, some properties of nonholonomic

  16. Diurnal variations of Titan

    Science.gov (United States)

    Cui, J.; Galand, M.; Yelle, R. V.; Vuitton, V.; Wahlund, J.-E.; Lavvas, P. P.; Mueller-Wodarg, I. C. F.; Kasprzak, W. T.; Waite, J. H.

    2009-04-01

    We present our analysis of the diurnal variations of Titan's ionosphere (between 1,000 and 1,400 km) based on a sample of Ion Neutral Mass Spectrometer (INMS) measurements in the Open Source Ion (OSI) mode obtained from 8 close encounters of the Cassini spacecraft with Titan. Though there is an overall ion depletion well beyond the terminator, the ion content on Titan's nightside is still appreciable, with a density plateau of ~700 cm-3 below ~1,300 km. Such a plateau is associated with the combination of distinct diurnal variations of light and heavy ions. Light ions (e.g. CH5+, HCNH+, C2H5+) show strong diurnal variation, with clear bite-outs in their nightside distributions. In contrast, heavy ions (e.g. c-C3H3+, C2H3CNH+, C6H7+) present modest diurnal variation, with significant densities observed on the nightside. We propose that the distinctions between light and heavy ions are associated with their different chemical loss pathways, with the former primarily through "fast" ion-neutral chemistry and the latter through "slow" electron dissociative recombination. The INMS data suggest day-to-night transport as an important source of ions on Titan's nightside, to be distinguished from the conventional scenario of auroral ionization by magnetospheric particles as the only ionizing source on the nightside. This is supported by the strong correlation between the observed night-to-day ion density ratios and the associated ion lifetimes. We construct a time-dependent ion chemistry model to investigate the effects of day-to-night transport on the ionospheric structures of Titan. The predicted diurnal variation has similar general characteristics to those observed, with some apparent discrepancies which could be reconciled by imposing fast horizontal thermal winds in Titan's upper atmosphere.

  17. Spinning fluids in general relativity: a variational formulation

    International Nuclear Information System (INIS)

    Oliveira, H.P. de; Salim, J.M.

    1990-01-01

    In this paper we present a variational formulation for spinning fluids in General Relativity. In our model each volume element of the fluid has rigid microstructure. We deduce a symmetrical energy-moment tensor where there is an explicit contribution of kinetic spin energy to the total energy. (author)

  18. Density variations in a reactor during liquid full dimerization

    NARCIS (Netherlands)

    Golombok, M.; Bruijn, J.

    2000-01-01

    In a liquid full plug flow reactor during lower olefin dimerization, the assumption of constant density is not valid—the volume of a plug changes as it proceeds along the reactor. The observed kinetics depend on the density variation in the reactor as the conversion proceeds towards a distribution

  19. Relation of atmogeochemical field variations to radon metronomy

    International Nuclear Information System (INIS)

    Gruntorad, J.

    1996-01-01

    Atmogeochemical field variations were monitored through the equivalent volume activity of radon. The interdependences between the various physical variables and the radon activity are presented and discussed, and it is shown that the problem is very complex and a number of factors have to be taken into account. (P.A.). 10 figs., 24 refs

  20. 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.

  1. Volume 9 Number 1

    African Journals Online (AJOL)

    OLUWOLE

    Agro-Science Journal of Tropical Agriculture, Food, Environment and Extension. Volume 9 Number 1 ... of persistent dumping of cheap subsidized food imports from developed ... independence of the inefficiency effects in the two estimation ...

  2. BP volume reduction equipment

    International Nuclear Information System (INIS)

    Kitamura, Yoshinori; Muroo, Yoji; Hamanaka, Isao

    2003-01-01

    A new type of burnable poison (BP) volume reduction system is currently being developed. Many BP rods, a subcomponent of spent fuel assemblies are discharged from nuclear power reactors. This new system reduces the overall volume of BP rods. The main system consists of BP rod cutting equipment, equipment for the recovery of BP cut pieces, and special transport equipment for the cut rods. The equipment is all operated by hydraulic press cylinders in water to reduce operator exposure to radioactivity. (author)

  3. Electroanalytical chemistry. Volume 14

    International Nuclear Information System (INIS)

    Bard, A.J.

    1986-01-01

    This volume is part of a series aimed at authoritative reviews of electroanalytical techniques and related areas of investigation. Volume 14 clearly maintains the high standards and proven usefulness of the series. Topics covered include conformation change and isomerization associated with electrode reactions, infrared vibrational spectroscopy of the electrode-solution interface, and precision in linear sweep and cyclic voltametry. A short history of electrochemical techniques which include the term square wave is provided

  4. 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 areas...... resolutions and single gauge rainfall was fed to a MOUSE run-off model. The flow and total volume over the event is evaluated....

  5. 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.

  6. Reachable volume RRT

    KAUST Repository

    McMahon, Troy; Thomas, Shawna; Amato, Nancy M.

    2015-01-01

    © 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.

  7. Conformable variational iteration method

    Directory of Open Access Journals (Sweden)

    Omer Acan

    2017-02-01

    Full Text Available In this study, we introduce the conformable variational iteration method based on new defined fractional derivative called conformable fractional derivative. This new method is applied two fractional order ordinary differential equations. To see how the solutions of this method, linear homogeneous and non-linear non-homogeneous fractional ordinary differential equations are selected. Obtained results are compared the exact solutions and their graphics are plotted to demonstrate efficiency and accuracy of the method.

  8. Indexes to Volume 78

    Indian Academy of Sciences (India)

    A higher-dimensional Bianchi type-I inflationary Universe in general relativity ... confinement as parent in the variationally improved perturbation theory. Bhaskar Jyoti .... quantum well under hydrostatic pressure and electric field. S Panda.

  9. Altitude Acclimatization and Blood Volume: Effects of Exogenous Erythrocyte Volume Expansion

    National Research Council Canada - National Science Library

    Sawka, M

    1996-01-01

    ...: (a) altitude acclimatization effects on erythrocyte volume and plasma volume; (b) if exogenous erythrocyte volume expansion alters subsequent erythrocyte volume and plasma volume adaptations; (c...

  10. Somaclonal variation in rice

    International Nuclear Information System (INIS)

    Kucherenko, L.

    1990-01-01

    Full text: 32 varieties of Oryza sativa L. ssp. japonica were used as donors for callus induction from somatic tissues. In some cases, the callus was treated before regeneration with the chemical mutagen MNU. Some of the regenerated plants demonstrated heritable alterations, among them chlorophyll deficiencies, variation in plant height, awness, glume colouring and fertility. Along with these, a number of lines with agronomically valuable alterations concerning maturity time, panicle structure, plant productivity and grain quality were found. The spectrum of variability was very wide. Vivipary was noticed. Superdwarfs with plant height of about 15 cm were found. Plants with no visible distinctions could be variants too, for example, with increased protein content or disease resistance. The rate and the spectrum of the somaclonal variation were not influenced by the culture media but depended on the donor's genotype. On the basis of somaclonal variation a variety 'Bioryza' was developed. It is an early maturing (about 95-100 days), long grain variety, with grain yield up to 8 t/ha. (author)

  11. Canonical variate regression.

    Science.gov (United States)

    Luo, Chongliang; Liu, Jin; Dey, Dipak K; Chen, Kun

    2016-07-01

    In many fields, multi-view datasets, measuring multiple distinct but interrelated sets of characteristics on the same set of subjects, together with data on certain outcomes or phenotypes, are routinely collected. The objective in such a problem is often two-fold: both to explore the association structures of multiple sets of measurements and to develop a parsimonious model for predicting the future outcomes. We study a unified canonical variate regression framework to tackle the two problems simultaneously. The proposed criterion integrates multiple canonical correlation analysis with predictive modeling, balancing between the association strength of the canonical variates and their joint predictive power on the outcomes. Moreover, the proposed criterion seeks multiple sets of canonical variates simultaneously to enable the examination of their joint effects on the outcomes, and is able to handle multivariate and non-Gaussian outcomes. An efficient algorithm based on variable splitting and Lagrangian multipliers is proposed. Simulation studies show the superior performance of the proposed approach. We demonstrate the effectiveness of the proposed approach in an [Formula: see text] intercross mice study and an alcohol dependence study. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. Free-volume study of ethylene - vinyl alcohol copolymer evaluated through positronium lifetime measurement

    International Nuclear Information System (INIS)

    Ito, K.; Hong-ling Li; Ujihira, Y.; Nomura, K.; Saito, Y.; Yamamoto, T.; Nishihara, Y.

    2003-01-01

    The free-volume, of size ranging from 0.2 to 0.4 nm in radius, in an ethylene-vinyl alcohol copolymer was estimated using positronium lifetime measurement to elucidate the dependence of oxygen permeability on the free-volume size and fraction, on the ethylene content and on the crystallinity. The permeability and the free-volume fraction with varying the ethylene content were well related and the relation was interpreted based on the free-volume theory near below and above the glass transition temperature. On the other hand, the crystallinity significantly influenced the fraction of the amorphous region, where the free-volume hole exists, along with a slight change of the free-volume size. The variation of the permeability with the crystalline degree cannot be explained from the averaged free-volume fraction estimated by the whole volume of the polymer, but the permeability correlated with the free-volume size apparently. (author)

  13. Effective orbital volume and eyeball position: an MRI study.

    Science.gov (United States)

    Detorakis, Efstathios T; Drakonaki, Eleni; Papadaki, Efrosini; Pallikaris, Ioannis G; Tsilimbaris, Miltiadis K

    2010-10-01

    Previous studies have examined factors affecting the position of the eyeball to the orbit. This study examined the role of effective orbital volume (EOV), defined as the difference between orbital and eyeball volume, as a determinant of eyeball position, using MRI scans. Forty-six patients were recruited from the Department of Ophthalmology of the University Hospital of Heraklion, Crete Greece. Patients with a history of orbital disease were excluded. Distances between eyeball poles and orbital landmarks were measured in T1 weighted transverse, sagittal and coronal orbital images. The protrusion of the eyeball in the sagittal and transverse planes was recorded. The volume of the eyeball and bony orbit, the EOV, the volume of the extraocular muscles as well as clinical information (age, gender, Hertel exophthalmometry) were also recorded. EOV was significantly associated with orbital volume but not with eyeball volume. EOV was also significantly associated with transverse and sagittal globe protrusions. Females displayed significantly lower orbital and eyeball volumes as well as EOV than males but higher transverse globe protrusion than males. Variations in EOV are associated with orbital volume rather than with eyeball volume. EOV is associated with globe protrusion and may be taken into account in the planning of various procedures, including orbital decompression, treatment of enophthalmos or the size of orbital implants following enucleation.

  14. Effect of water volume based on water absorption and mixing time on physical properties of tapioca starch – wheat composite bread

    Science.gov (United States)

    Prameswari, I. K.; Manuhara, G. J.; Amanto, B. S.; Atmaka, W.

    2018-05-01

    Tapioca starch application in bread processing change water absorption level by the dough, while sufficient mixing time makes the optimal water absorption. This research aims to determine the effect of variations in water volume and mixing time on physical properties of tapioca starch – wheat composite bread and the best method for the composite bread processing. This research used Complete Randomized Factorial Design (CRFD) with two factors: variations of water volume (111,8 ml, 117,4 ml, 123 ml) and mixing time (16 minutes, 17 minutes 36 seconds, 19 minutes 12 seconds). The result showed that water volume significantly affected on dough volume, bread volume and specific volume, baking expansion, and crust thickness. Mixing time significantly affected on dough volume and specific volume, bread volume and specific volume, baking expansion, bread height, and crust thickness. While the combination of water volume and mixing time significantly affected for all physical properties parameters except crust thickness.

  15. 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.

  16. Functional changes in CSF volume estimated using measurement of water T2 relaxation

    NARCIS (Netherlands)

    Piechnik, S.K.; Evans, J.; Bary, L.H.; Wise, R.G.; Jezzard, P.

    2009-01-01

    Cerebrospinal fluid (CSF) provides hydraulic suspension for the brain. The general concept of bulk CSF production, circulation, and reabsorption is well established, but the mechanisms of momentary CSF volume variation corresponding to vasoreactive changes are far less understood. Nine individuals

  17. The volume of a soliton

    International Nuclear Information System (INIS)

    Adam, C.; Haberichter, M.; Wereszczynski, A.

    2016-01-01

    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.

  18. 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.

  19. 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

  20. Volume holographic memory

    Directory of Open Access Journals (Sweden)

    Cornelia Denz

    2000-05-01

    Full Text Available Volume holography represents a promising alternative to existing storage technologies. Its parallel data storage leads to high capacities combined with short access times and high transfer rates. The design and realization of a compact volume holographic storage demonstrator is presented. The technique of phase-coded multiplexing implemented to superimpose many data pages in a single location enables to store up to 480 holograms per storage location without any moving parts. Results of analog and digital data storage are shown and real time optical image processing is demonstrated.

  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; Hulshoff Pol, Hilleke E; Ikeda, Masashi; Jack, 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

    2017-01-18

    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 (r g =-0.155). Our findings suggest novel biological pathways through which human genetic variation influences hippocampal volume and risk for neuropsychiatric illness.

  2. Ocular volume measured by CT scans

    International Nuclear Information System (INIS)

    Hahn, F.J.; Wei-Kom Chu

    1984-01-01

    Newer CT scans have greatly enhanced oculometric research and made it possible to measure ocular dimensions. With these measurements, ocular volume can be more accurately estimated to understand its relationship with age and sex. One hundred CT orbit scans with presumed normal eyes were used for the data base. The mean values and normal variations of ocular volumes at various ages in both sexes are presented. Rapid growth of the eyeball was noted during the first 24 months of age. It reached its peak between the ages of 18 and 30 years of age, after which there was a reduction. Results may be of help in recognizing eye abnormalities such as microophthalmus and macrophthalmia. (orig.)

  3. Density variation and piezoelectric properties of Ba (Ti1− xSnx) O3 ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 35; Issue 5. Density variation and piezoelectric properties of Ba(Ti1−Sn)O3 ceramics prepared from nanocrystalline powders ... The density variation of the ceramics with sintering temperature has been studied by sintering the samples at different temperatures.

  4. 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.)

  5. Coarse Grained Exponential Variational Autoencoders

    KAUST Repository

    Sun, Ke; Zhang, Xiangliang

    2017-01-01

    Variational autoencoders (VAE) often use Gaussian or category distribution to model the inference process. This puts a limit on variational learning because this simplified assumption does not match the true posterior distribution, which is usually

  6. Variational submanifolds of Euclidean spaces

    Science.gov (United States)

    Krupka, D.; Urban, Z.; Volná, J.

    2018-03-01

    Systems of ordinary differential equations (or dynamical forms in Lagrangian mechanics), induced by embeddings of smooth fibered manifolds over one-dimensional basis, are considered in the class of variational equations. For a given non-variational system, conditions assuring variationality (the Helmholtz conditions) of the induced system with respect to a submanifold of a Euclidean space are studied, and the problem of existence of these "variational submanifolds" is formulated in general and solved for second-order systems. The variational sequence theory on sheaves of differential forms is employed as a main tool for the analysis of local and global aspects (variationality and variational triviality). The theory is illustrated by examples of holonomic constraints (submanifolds of a configuration Euclidean space) which are variational submanifolds in geometry and mechanics.

  7. Introduction to global variational geometry

    CERN Document Server

    Krupka, Demeter

    2015-01-01

    The book is devoted to recent research in the global variational theory on smooth manifolds. Its main objective is an extension of the classical variational calculus on Euclidean spaces to (topologically nontrivial) finite-dimensional smooth manifolds; to this purpose the methods of global analysis of differential forms are used. Emphasis is placed on the foundations of the theory of variational functionals on fibered manifolds - relevant geometric structures for variational principles in geometry, physical field theory and higher-order fibered mechanics. The book chapters include: - foundations of jet bundles and analysis of differential forms and vector fields on jet bundles, - the theory of higher-order integral variational functionals for sections of a fibred space, the (global) first variational formula in infinitesimal and integral forms- extremal conditions and the discussion of Noether symmetries and generalizations,- the inverse problems of the calculus of variations of Helmholtz type- variational se...

  8. 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.

  9. Variations in brain DNA

    Directory of Open Access Journals (Sweden)

    Jesus eAvila

    2014-11-01

    Full Text Available It is assumed that DNA sequences are conserved in the diverse cell types present in a multicellular organism like the human being. Thus, in order to compare the sequences in the genome of DNA from different individuals, nucleic acid is commonly isolated from a single tissue. In this regard, blood cells are widely used for this purpose because of their availability. Thus blood DNA has been used to study genetic familiar diseases that affect other tissues and organs, such as the liver, heart, and brain. While this approach is valid for the identification of familial diseases in which mutations are present in parental germinal cells and, therefore, in all the cells of a given organism, it is not suitable to identify sporadic diseases in which mutations might occur in specific somatic cells. This review addresses somatic DNA variations in different tissues or cells (mainly in the brain of single individuals and discusses whether the dogma of DNA invariance between cell types is indeed correct. We will also discuss how single nucleotide somatic variations arise, focusing on the presence of specific DNA mutations in the brain.

  10. Harmonically excited orbital variations

    International Nuclear Information System (INIS)

    Morgan, T.

    1985-01-01

    Rephrasing the equations of motion for orbital maneuvers in terms of Lagrangian generalized coordinates instead of Newtonian rectangular cartesian coordinates can make certain harmonic terms in the orbital angular momentum vector more readily apparent. In this formulation the equations of motion adopt the form of a damped harmonic oscillator when torques are applied to the orbit in a variationally prescribed manner. The frequencies of the oscillator equation are in some ways unexpected but can nonetheless be exploited through resonant forcing functions to achieve large secular variations in the orbital elements. Two cases are discussed using a circular orbit as the control case: (1) large changes in orbital inclination achieved by harmonic excitation rather than one impulsive velocity change, and (2) periodic and secular changes to the longitude of the ascending node using both stable and unstable excitation strategies. The implications of these equations are also discussed for both artificial satellites and natural satellites. For the former, two utilitarian orbits are suggested, each exploiting a form of harmonic excitation. 5 refs

  11. 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

  12. Another year, another volume

    Science.gov (United States)

    Bill Block

    2012-01-01

    This issue represents the final one in volume 76 of Journal of Wildlife Management. As this one is pretty much in the books, one cannot help but wonder what the future holds for the journal. Lenny Brennan is putting together a piece for Wildlife Society Bulletin to examine how The Wildlife Society publications have changed through time. He solicited input from past and...

  13. 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

  14. Thermodynamics with pressure and volume under charged particle absorption

    Science.gov (United States)

    Gwak, Bogeun

    2017-11-01

    We investigate the variation of the charged anti-de Sitter black hole under charged particle absorption by considering thermodynamic volume. When the energy of the particle is considered to contribute to the internal energy of the black hole, the variation exactly corresponds to the prediction of the first law of thermodynamics. Nevertheless, we find the decrease of the Bekenstein-Hawking entropy for extremal and near-extremal black holes under the absorption, which is an irreversible process. This violation of the second law of thermodynamics is only found when considering thermodynamic volume. We test the weak cosmic censorship conjecture affected by the violation. Fortunately, the conjecture is still valid, but extremal and near-extremal black holes do not change their configurations when any particle enters the black hole. This result is quite different from the case in which thermodynamic volume is not considered.

  15. Variationally Asymptotically Stable Difference Systems

    Directory of Open Access Journals (Sweden)

    Goo YoonHoe

    2007-01-01

    Full Text Available We characterize the h-stability in variation and asymptotic equilibrium in variation for nonlinear difference systems via n∞-summable similarity and comparison principle. Furthermore we study the asymptotic equivalence between nonlinear difference systems and their variational difference systems by means of asymptotic equilibria of two systems.

  16. 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.

  17. Striatal volume predicts level of video game skill acquisition.

    Science.gov (United States)

    Erickson, Kirk I; Boot, Walter R; Basak, Chandramallika; Neider, Mark B; Prakash, Ruchika S; Voss, Michelle W; Graybiel, Ann M; Simons, Daniel J; Fabiani, Monica; Gratton, Gabriele; Kramer, Arthur F

    2010-11-01

    Video game skills transfer to other tasks, but individual differences in performance and in learning and transfer rates make it difficult to identify the source of transfer benefits. We asked whether variability in initial acquisition and of improvement in performance on a demanding video game, the Space Fortress game, could be predicted by variations in the pretraining volume of either of 2 key brain regions implicated in learning and memory: the striatum, implicated in procedural learning and cognitive flexibility, and the hippocampus, implicated in declarative memory. We found that hippocampal volumes did not predict learning improvement but that striatal volumes did. Moreover, for the striatum, the volumes of the dorsal striatum predicted improvement in performance but the volumes of the ventral striatum did not. Both ventral and dorsal striatal volumes predicted early acquisition rates. Furthermore, this early-stage correlation between striatal volumes and learning held regardless of the cognitive flexibility demands of the game versions, whereas the predictive power of the dorsal striatal volumes held selectively for performance improvements in a game version emphasizing cognitive flexibility. These findings suggest a neuroanatomical basis for the superiority of training strategies that promote cognitive flexibility and transfer to untrained tasks.

  18. Evaluation of variational approximations

    International Nuclear Information System (INIS)

    Trevisan, L.A.

    1991-01-01

    In Feynman's approach to quantum statistical mechanics, the partition function can e represented as a path integral. A recently proposed variation method of Feynman-Kleinert is able to transform the path integral into an integral in phase space, in which the quantum fluctuations have been taken care of by introducing the effective classical potential. This method has been testes with succeed for the smooth potentials and for the singular potential of delta. The method to the strong singular potentials is applied: a quadratic potential and a linear potential both with a rigid wall at the origin. By satisfying the condition that the density of the particle be vanish at the origin, and adapted method of Feynman-Kleinert in order to improve the method is introduced. (author)

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

    NARCIS (Netherlands)

    Germans, Menno R.; de Witt Hamer, Philip C.; van Boven, Leonard J.; Zwinderman, Koos A. H.; Bouma, Gerrit J.

    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

  20. 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

    the hypovolemia. Alterations in pV and pulsatility indices were closely related to changes in stroke volume, and a negative correlation was found between diastolic velocities and stroke volume. regression analysis showed no significant relation between variations in velocity parameters and blood pressure. Results...

  1. Symptom dimensions are associated with progressive brain volume changes in schizophrenia

    NARCIS (Netherlands)

    Collin, G.; Derks, E. M.; van Haren, N. E. M.; Schnack, H. G.; Hulshoff Pol, H. E.; Kahn, R. S.; Cahn, W.

    2012-01-01

    Background: There is considerable variation in progressive brain volume changes in schizophrenia. Whether this is related to the clinical heterogeneity that characterizes the illness remains to be determined. This study examines the relationship between change in brain volume over time and

  2. Dynamics of nonholonomic systems from variational principles embedded variation identity

    International Nuclear Information System (INIS)

    Guo Yongxin; Liu Shixing; Liu Chang; Chang Peng

    2009-01-01

    Nondeterminacy of dynamics, i.e., the nonholonomic or the vakonomic, fundamental variational principles, e.g., the Lagrange-d'Alembert or Hamiltonian, and variational operators, etc., of nonholonomic mechanical systems can be attributed to the non-uniqueness of ways how to realize nonholonomic constraints. Making use of a variation identity of nonholonomic constraints embedded into the Hamilton's principle with the method of Lagrange undetermined multipliers, three kinds of dynamics for the nonholonomic systems including the vakonomic and nonholonomic ones and a new one are obtained if the variation is respectively reduced to three conditional variations: vakonomic variation, Hoelder's variation and Suslov's variation, defined by the identity. Therefore, different dynamics of nonholonomic systems can be derived from an integral variational principle, utilizing one way of embedding constraints into the principle, with different variations. It is verified that the similar embedding of the identity into the Lagrange-d'Alembert principle gives rise to the nonholonomic dynamics but fails to give the vakonomic one unless the constraints are integrable.

  3. Dynamics of nonholonomic systems from variational principles embedded variation identity

    Energy Technology Data Exchange (ETDEWEB)

    Guo Yongxin, E-mail: yxguo@lnu.edu.c [College of Physics, Liaoning University, Shenyang 110036 (China); Liu Shixing [College of Physics, Liaoning University, Shenyang 110036 (China); Liu Chang; Chang Peng [Department of Applied Mechanics, Beijing Institute of Technology, Beijing 100081 (China)

    2009-10-19

    Nondeterminacy of dynamics, i.e., the nonholonomic or the vakonomic, fundamental variational principles, e.g., the Lagrange-d'Alembert or Hamiltonian, and variational operators, etc., of nonholonomic mechanical systems can be attributed to the non-uniqueness of ways how to realize nonholonomic constraints. Making use of a variation identity of nonholonomic constraints embedded into the Hamilton's principle with the method of Lagrange undetermined multipliers, three kinds of dynamics for the nonholonomic systems including the vakonomic and nonholonomic ones and a new one are obtained if the variation is respectively reduced to three conditional variations: vakonomic variation, Hoelder's variation and Suslov's variation, defined by the identity. Therefore, different dynamics of nonholonomic systems can be derived from an integral variational principle, utilizing one way of embedding constraints into the principle, with different variations. It is verified that the similar embedding of the identity into the Lagrange-d'Alembert principle gives rise to the nonholonomic dynamics but fails to give the vakonomic one unless the constraints are integrable.

  4. Intralesional and metastatic heterogeneity in malignant melanomas demonstrated by stereologic estimates of nuclear volume

    DEFF Research Database (Denmark)

    Sørensen, Flemming Brandt; Erlandsen, M

    1990-01-01

    Regional variability of nuclear 3-dimensional size can be estimated objectively using point-sampled intercepts obtained from different, defined zones within individual neoplasms. In the present study, stereologic estimates of the volume-weighted mean nuclear volume, nuclear vv, within peripheral...... melanomas showed large interindividual variation. This finding emphasizes that unbiased estimates of nuclear vv are robust to regional heterogeneity of nuclear volume and thus suitable for purposes of objective, quantitative malignancy grading of melanomas....

  5. The effect of water volume and mixing time on physical properties of bread made from modified cassava starch-wheat composite flour

    Science.gov (United States)

    Srirejeki, S.; Manuhara, G. J.; Amanto, B. S.; Atmaka, W.; Laksono, P. W.

    2018-03-01

    Modification of cassava starch with soaking in the whey (by product on cheese production) resulted in changes of the flour characteristics. Adjustments of processing condition are important to be studied in the making of bread from modified cassava starch and wheat composite flour (30:70). This research aims to determine the effect of water volume and mixing time on the physical properties of the bread. The experimental design of this research was Completely Randomized Factorial Design (CRFD) with two factors which were water volume and mixing time. The variation of water volume significantly affected on bread height, dough volume, dough specific volume, and crust thickness. The variation of mixing time had a significant effect on the increase of dough volume and dough specific volume. The combination of water volume and mixing time had a significant effect on dough height, bread volume, bread specific volume, baking expansion, and weight loss.

  6. Quantum volume hologram

    International Nuclear Information System (INIS)

    Vasilyev, Denis V.; Sokolov, Ivan V.; Polzik, Eugene S.

    2010-01-01

    We propose a scheme for parallel spatially multimode quantum memory for light. The scheme is based on a counterpropagating quantum signal wave and a strong classical reference wave as in a classical volume hologram and therefore can be called a quantum volume hologram. The medium for the hologram consists of a spatially extended ensemble of atoms placed in a magnetic field. The write-in and readout of this quantum hologram is as simple as that of its classical counterpart and consists of a single-pass illumination. In addition, we show that the present scheme for a quantum hologram is less sensitive to diffraction and therefore is capable of achieving a higher density of storage of spatial modes as compared to previous proposals. We present a feasibility study and show that experimental implementation is possible with available cold atomic samples. A quantum hologram capable of storing entangled images can become an important ingredient in quantum information processing and quantum imaging.

  7. Viability Assessment Volume 2

    International Nuclear Information System (INIS)

    1998-01-01

    This volume describes the major design features of the Monitored Geologic Repository. This document is not intended to provide an exhaustive, detailed description of the repository design. Rather, this document summarizes the major systems and primary elements of the design that are radiologically significant, and references the specific technical documents and design analyses wherein the details can be found. Not all portions of the design are at the same level of completeness. Highest priority has been given to assigning resources to advance the design of the Monitored Geologic Repository features that are important to radiological safety and/or waste isolation and for which there is no NRC licensing precedent. Those features that are important to radiological safety and/or waste isolation, but for which there is an NRC precedent, receive second priority. Systems and features that have no impact on radiological safety or waste isolation receive the lowest priority. This prioritization process, referred to as binning, is discussed in more detail in Section 2.3. Not every subject discussed in this volume is given equal treatment with regard to the level of detail provided. For example, less detail is provided for the surface facility design than for the subsurface and waste package designs. This different level of detail is intentional. Greater detail is provided for those functions, structures, systems, and components that play key roles with regard to protecting radiological health and safety and that are not common to existing nuclear facilities already licensed by NRC. A number of radiological subjects are not addressed in the VA, (e.g., environmental qualification of equipment). Environmental qualification of equipment and other radiological safety considerations will be addressed in the LA. Non-radiological safety considerations such as silica dust control and other occupational safety considerations are considered equally important but are not addressed in

  8. Poloidal variations in toroidal fusion reactor wall power loadings

    International Nuclear Information System (INIS)

    Carroll, M.C.; Miley, G.H.

    1985-01-01

    A geometric formulation is developed by the authors for determining poloidal variations in bremmstrahlung, cyclotron radiation, and neutron wall power loadings in toroidal fusion devices. Assuming toroidal symmetry and utilizing a numerical model which partitions the plasma into small cells, it was generally found that power loadings are highest on the outer surface of the torus, although variations are not as large as some have predicted. Results are presented for various plasma power generation configurations, plasma volume fractions, and toroidal aspect ratios, and include plasma and wall blockage effects

  9. Comparison of respiratory-induced variations in photoplethysmographic signals

    International Nuclear Information System (INIS)

    Li, Jin; Jin, Jie; Chen, Xiang; Sun, Weixin; Guo, Ping

    2010-01-01

    Photoplethysmography (PPG) is an optical method for detecting blood volume changes in tissue. Respiratory-induced intensity, frequency and amplitude variations are contained in the PPG signal; thus, an understanding of the relationships between all of these variations and respiration is essential to advancing respiration monitoring based on PPG. This study investigated correlations between respiratory-induced variations extracted from PPG and simultaneous respiratory signals. PPG signals were recorded from 28 healthy subjects under eight different conditions. Six respiratory-induced variations, i.e. the period of the systole, diastole and pulse, the amplitude of the systole and diastole, and the intensity variation, were determined from the PPG signal. The results indicate that, compared with the period of the pulse, the period of the systole and diastole correlates weakly with respiration; the amplitude of the diastole has a stronger correlation with respiration than the amplitude of the systole. For men, when the respiratory rate is less than 10 breaths min −1 , the period of the pulse has the strongest correlation with respiration, whereas up to or above 15 breaths min −1 , the intensity variation becomes strongest in the sitting posture, while the amplitude of the diastole is strongest in the supine posture. For women, compared with the other variations, the period of the pulse has nearly the strongest correlation with respiration, independent of respiratory rate or posture

  10. 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)

  11. Polarizer reflectivity variations

    International Nuclear Information System (INIS)

    Ozarski, R.G.; Prior, J.

    1980-01-01

    On Shiva the beam energy along the chain is monitored using available reflections and/or transmission through beam steering, splitting, and polarizing optics without the intrusion of any additional glass for diagnostics. On the preamp table the diagnostic signal is obtained from the signal transmitted through turning mirrors. At the input of each chain the signal is obtained from the transmission through one of the mirrors used for the chain input alignment sensor (CHIP). At the chain output the transmission through the final turning mirror is used. These diagnostics have proved stable and reliable. However, one of the prime diagnostic locations is at the output of the beta rod. The energy at this location is measured by collecting small reflections from the last polarizer surface of the beta Pockels cell polarizer package. Unfortunately, calibration of this diagnostic has varied randomly, seldom remaining stable for a week or more. The cause of this fluctuation has been investigated for the past year and'it has been discovered that polarizer reflectivity varies with humidity. This report will deal with the possible causes that were investigated, the evidence that humidity is causing the variation, and the associated mechanism

  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. Limitations of the planning organ at risk volume (PRV) concept.

    Science.gov (United States)

    Stroom, Joep C; Heijmen, Ben J M

    2006-09-01

    Previously, we determined a planning target volume (PTV) margin recipe for geometrical errors in radiotherapy equal to M(T) = 2 Sigma + 0.7 sigma, with Sigma and sigma standard deviations describing systematic and random errors, respectively. In this paper, we investigated margins for organs at risk (OAR), yielding the so-called planning organ at risk volume (PRV). For critical organs with a maximum dose (D(max)) constraint, we calculated margins such that D(max) in the PRV is equal to the motion averaged D(max) in the (moving) clinical target volume (CTV). We studied margins for the spinal cord in 10 head-and-neck cases and 10 lung cases, each with two different clinical plans. For critical organs with a dose-volume constraint, we also investigated whether a margin recipe was feasible. For the 20 spinal cords considered, the average margin recipe found was: M(R) = 1.6 Sigma + 0.2 sigma with variations for systematic and random errors of 1.2 Sigma to 1.8 Sigma and -0.2 sigma to 0.6 sigma, respectively. The variations were due to differences in shape and position of the dose distributions with respect to the cords. The recipe also depended significantly on the volume definition of D(max). For critical organs with a dose-volume constraint, the PRV concept appears even less useful because a margin around, e.g., the rectum changes the volume in such a manner that dose-volume constraints stop making sense. The concept of PRV for planning of radiotherapy is of limited use. Therefore, alternative ways should be developed to include geometric uncertainties of OARs in radiotherapy planning.

  14. [Target volume margins for lung cancer: internal target volume/clinical target volume].

    Science.gov (United States)

    Jouin, A; Pourel, N

    2013-10-01

    The aim of this study was to carry out a review of margins that should be used for the delineation of target volumes in lung cancer, with a focus on margins from gross tumour volume (GTV) to clinical target volume (CTV) and internal target volume (ITV) delineation. Our review was based on a PubMed literature search with, as a cornerstone, the 2010 European Organisation for Research and Treatment of Cancer (EORTC) recommandations by De Ruysscher et al. The keywords used for the search were: radiotherapy, lung cancer, clinical target volume, internal target volume. The relevant information was categorized under the following headings: gross tumour volume definition (GTV), CTV-GTV margin (first tumoural CTV then nodal CTV definition), in field versus elective nodal irradiation, metabolic imaging role through the input of the PET scanner for tumour target volume and limitations of PET-CT imaging for nodal target volume definition, postoperative radiotherapy target volume definition, delineation of target volumes after induction chemotherapy; then the internal target volume is specified as well as tumoural mobility for lung cancer and respiratory gating techniques. Finally, a chapter is dedicated to planning target volume definition and another to small cell lung cancer. For each heading, the most relevant and recent clinical trials and publications are mentioned. Copyright © 2013. Published by Elsevier SAS.

  15. 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......, thus creating a personalized atlas. The knowledge built into the atlas is e.g. location of anatomical regions and landmarks of importance to surgery planning and evaluation or population studies. With these correspondences, various analyses could be carried out e.g. quantification of growth, inter...

  16. 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…

  17. Sasaki-Einstein Manifolds and Volume Minimisation

    CERN Document Server

    Martelli, D; Yau, S T; Martelli, Dario; Sparks, James; Yau, Shing-Tung

    2006-01-01

    We study a variational problem whose critical point determines the Reeb vector field for a Sasaki-Einstein manifold. This extends our previous work on Sasakian geometry by lifting the condition that the manifolds are toric. We show that the Einstein-Hilbert action, restricted to a space of Sasakian metrics on a link L in a Calabi-Yau cone M, is the volume functional, which in fact is a function on the space of Reeb vector fields. We relate this function both to the Duistermaat-Heckman formula and also to a limit of a certain equivariant index on M that counts holomorphic functions. Both formulae may be evaluated by localisation. This leads to a general formula for the volume function in terms of topological fixed point data. As a result we prove that the volume of any Sasaki-Einstein manifold, relative to that of the round sphere, is always an algebraic number. In complex dimension n=3 these results provide, via AdS/CFT, the geometric counterpart of a-maximisation in four dimensional superconformal field theo...

  18. Elemental Spatiotemporal Variations of Total Suspended Particles in Jeddah City

    OpenAIRE

    Kadi, Mohammad W.

    2014-01-01

    Elements associated with total suspended particulate matter (TSP) in Jeddah city were determined. Using high-volume samplers, TSP samples were simultaneously collected over a one-year period from seven sampling sites. Samples were analyzed for Al, Ba, Ca, Cu, Mg, Fe, Mn, Zn, Ti, V, Cr, Co, Ni, As, and Sr. Results revealed great dependence of element contents on spatial and temporal variations. Two sites characterized by busy roads, workshops, heavy population, and heavy trucking have high lev...

  19. A survey of variational principles

    International Nuclear Information System (INIS)

    Lewins, J.D.

    1993-01-01

    In this article survey of variational principles has been given. Variational principles play a significant role in mathematical theory with emphasis on the physical aspects. There are two principals used i.e. to represent the equation of the system in a succinct way and to enable a particular computation in the system to be carried out with greater accuracy. The survey of variational principles has ranged widely from its starting point in the Lagrange multiplier to optimisation principles. In an age of digital computation, these classic methods can be adapted to improve such calculations. We emphasize particularly the advantage of basic finite element methods on variational principles. (A.B.)

  20. Strong volume, stable prices

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    This article is the September-October 1993 market report, providing trading volume and prices in the Uranium market. Activity was brisk, with 15 deals concluded. Six were in the spot concentrates market, with four of the six deals involving U.S. utilities and approximately 1.8M pounds of U3O8 equivalent. There were five conversion deals announced, with four of the five deals involving U.S. utilities. Four deals were concluded in the enrichment market, and the deals involving U.S. utilities were approximately 327k SWUs. On the horizon, there are deals for approximately 4.1M SWU

  1. Volume of emphysema.

    OpenAIRE

    Turner, P; Whimster, W F

    1981-01-01

    A method of determining the volume of emphysema in excised lungs is presented, with its validation. This method is based on macroscopic point counting using a perforated grid but only the holes (points) overlying emphysema need be counted to produce results within a percentage standard error of 5%. Application of the method shows that an adequate assessment of emphysema cannot be made from one lung slice alone, and that the amount of emphysema found in one lung cannot be used to predict the a...

  2. 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...... of view as well as w.r.t. computational complexity. Finally, we present algorithms for both approaches for NMI which is comparable in speed to Sum of Squared Differences (SSD), and we illustrate the differences between PW and GPV on a number of registration examples....

  3. Environmental report 1995. Volume 2

    International Nuclear Information System (INIS)

    Harrach, R.J.; Failor, R.A.; Gallegos, G.M.

    1996-09-01

    This is Volume 2 of the Lawrence Livermore National Laboratory's (LLNL's) annual Environmental Report 1995. This volume is intended to support summary data from Volume 1 and is essentially a detailed data report that provides additional data points, where applicable. Some summary data are also included in Volume 2, and more detailed accounts are given of sample collection and analytical methods. Volume 2 includes information in eight chapters on monitoring of air, air effluent, sewage, surface water, ground water, soil and sediment, vegetation and foodstuff, and environmental radiation, as well as three chapters on ground water protection, compliance self-monitoring and quality assurance

  4. 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.

  5. A Variational Statistical-Field Theory for Polar Liquid Mixtures

    Science.gov (United States)

    Zhuang, Bilin; Wang, Zhen-Gang

    Using a variational field-theoretic approach, we derive a molecularly-based theory for polar liquid mixtures. The resulting theory consists of simple algebraic expressions for the free energy of mixing and the dielectric constant as functions of mixture composition. Using only the dielectric constants and the molar volumes of the pure liquid constituents, the theory evaluates the mixture dielectric constants in good agreement with the experimental values for a wide range of liquid mixtures, without using adjustable parameters. In addition, the theory predicts that liquids with similar dielectric constants and molar volumes dissolve well in each other, while sufficient disparity in these parameters result in phase separation. The calculated miscibility map on the dielectric constant-molar volume axes agrees well with known experimental observations for a large number of liquid pairs. Thus the theory provides a quantification for the well-known empirical ``like-dissolves-like'' rule. Bz acknowledges the A-STAR fellowship for the financial support.

  6. Bladder filling variation during radiation treatment of prostate cancer: Can the use of a bladder ultrasound scanner and biofeedback optimize bladder filling?

    International Nuclear Information System (INIS)

    Stam, Marcel R.; Lin, Emile N.J. Th. van; Vight, Lisette P. van der; Kaanders, Johannes; Visser, Andries G.

    2006-01-01

    Purpose: To investigate the use of a bladder ultrasound scanner in achieving a better reproducible bladder filling during irradiation of pelvic tumors, specifically prostate cancer. Methods and Materials: First, the accuracy of the bladder ultrasound scanner relative to computed tomography was validated in a group of 26 patients. Next, daily bladder volume variation was evaluated in a group of 18 patients. Another 16 patients participated in a biofeedback protocol, aiming at a more constant bladder volume. The last objective was to study correlations between prostate motion and bladder filling, by using electronic portal imaging device data on implanted gold markers. Results: A strong correlation between bladder scanner volume and computed tomography volume (r = 0.95) was found. Daily bladder volume variation was very high (1 Sd = 47.2%). Bladder filling and daily variation did not significantly differ between the control and the feedback group (47.2% and 40.1%, respectively). Furthermore, no linear correlations between bladder volume variation and prostate motion were found. Conclusions: This study shows large variations in daily bladder volume. The use of a biofeedback protocol yields little reduction in bladder volume variation. Even so, the bladder scanner is an easy to use and accurate tool to register these variations

  7. The dependence of prostate postimplant dosimetric quality on CT volume determination

    International Nuclear Information System (INIS)

    Merrick, Gregory S.; Butler, Wayne M.; Dorsey, Anthony T.; Lief, Jonathan H.

    1999-01-01

    the ultrasound volume approach. Despite the volume determinations being markedly different, no significant differences between the approaches were appreciated for V100, V150, V200, and D90. Large variations seen in D100 were uncorrelated to any of the other parameters and make D100 unsuitable as a quality indicator. Conclusions: In terms of a logarithmic measure, the variation between volumetric approach for V100, V150, V200, and D90 was less than one-fifth the variation of the CT volumes. These results which indicate relative independence of postimplant CT volume determination and dosimetric quality are only valid for a planning philosophy that includes the prostate with a periprostatic margin as the target volume

  8. Radwaste '86: proceedings volume

    International Nuclear Information System (INIS)

    Ainslie, L.C.

    1986-12-01

    The volume contains all the papers presented at the above Conference, which was held in Cape Town, South Africa from 7 to 12 September 1986. A total of 55 contributions cover the full spectrum of the theme of the Conference, which was subdivided into four sessions. Conditioning, treatment and management of radioactive waste: 12 papers reporting on experiences in various countries, as well as specialist topics such as the extraction of radioactive contaminants from reactor pool water. Containment, safe handling and long-term integrity of ILLW packages: 2 papers dealing with cask design. Transport and storage of radwaste and spent fuel: 7 papers ranging from broad overviews to specific operations in different parts of the world. Radioactive waste disposal and environmental impact: 32 papers covering topics from site selection, design and operation, to modelling and monitoring studies. South Africa's Vaalputs radioactive waste disposal facility is comprehensively described. The volume is a useful reference for anyone interested in the disposal of radioactive waste, especially in arid environments, as well as its treatment and management prior to disposal, and will appeal to a wide range of disciplines including engineers, geologists, geophysicists, life scientists and environmentalists. Of particular interest would be the intensive studies undertaken in South Africa prior to the establishment of a radioactive waste repository in that country

  9. Total volume versus bouts

    DEFF Research Database (Denmark)

    Chinapaw, Mai; Klakk, Heidi; Møller, Niels Christian

    2018-01-01

    BACKGROUND/OBJECTIVES: Examine the prospective relationship of total volume versus bouts of sedentary behaviour (SB) and moderate-to-vigorous physical activity (MVPA) with cardiometabolic risk in children. In addition, the moderating effects of weight status and MVPA were explored. SUBJECTS....../METHODS: Longitudinal study including 454 primary school children (mean age 10.3 years). Total volume and bouts (i.e. ≥10 min consecutive minutes) of MVPA and SB were assessed by accelerometry in Nov 2009/Jan 2010 (T1) and Aug/Oct 2010 (T2). Triglycerides, total cholesterol/HDL cholesterol ratio (TC:HDLC ratio......, with or without mutual adjustments between MVPA and SB. The moderating effects of weight status and MVPA (for SB only) were examined by adding interaction terms. RESULTS: Children engaged daily in about 60 min of total MVPA and 0-15 min/week in MVPA bouts. Mean total sedentary time was around 7 h/day with over 3...

  10. Limiting volume with modern ventilators.

    Science.gov (United States)

    Wing, Thomas J; Haan, Lutana; Ashworth, Lonny J; Anderson, Jeff

    2015-06-01

    The acute respiratory distress syndrome (ARDS) network low tidal-volume study comparing tidal volumes of 12 ml/kg versus 6 ml/kg was published in 2000. The study was stopped early as data revealed a 22% relative reduction in mortality rate when using 6 ml/kg tidal volume. The current generation of critical care ventilators allows the tidal volume to be set during volume-targeted, assist/control (volume A/C); however, some ventilators include options that may prevent the tidal volume from being controlled. The purpose of this bench study was to evaluate the delivered tidal volume, when these options are active, in a spontaneously breathing lung model using an electronic breathing simulator. Four ventilators were evaluated: CareFusion AVEA (AVEA), Dräger Evita® XL (Evita XL), Covidien Puritan Bennett® 840(TM) (PB 840), and Maquet SERVO-i (SERVO-i). Each ventilator was connected to the Hans Rudolph Electronic Breathing Simulator at an amplitude of 0 cm H2O and then 10 cm H2O. All four ventilators were set to deliver volume A/C, tidal volume 400 ml, respiratory rate 20 bpm, positive end-expiratory pressure 5 cm H2O, peak flowrate 60 L/min. The displayed tidal volume was recorded for each ventilator at the above settings with additional options OFF and then ON. The AVEA has two options in volume A/C: demand breaths and V-sync. When activated, these options allow the patient to exceed the set tidal volume. When using the Evita XL, the option AutoFlow can be turned ON or OFF, and when this option is ON, the tidal volume may vary. The PB 840 does not have any additional options that affect volume delivery, and it maintains the set tidal volume regardless of patient effort. The SERVO-i's demand valve allows additional flow if the patient's inspiratory flowrate exceeds the set flowrate, increasing the delivered tidal volume; this option can be turned OFF with the latest software upgrade. Modern ventilators have an increasing number of optional settings. These settings may

  11. Water-vapor pressure control in a volume

    Science.gov (United States)

    Scialdone, J. J.

    1978-01-01

    The variation with time of the partial pressure of water in a volume that has openings to the outside environment and includes vapor sources was evaluated as a function of the purging flow and its vapor content. Experimental tests to estimate the diffusion of ambient humidity through openings and to validate calculated results were included. The purging flows required to produce and maintain a certain humidity in shipping containers, storage rooms, and clean rooms can be estimated with the relationship developed here. These purging flows are necessary to prevent the contamination, degradation, and other effects of water vapor on the systems inside these volumes.

  12. Estimation of ocular volume from axial length.

    Science.gov (United States)

    Nagra, Manbir; Gilmartin, Bernard; Logan, Nicola S

    2014-12-01

    To determine which biometric parameters provide optimum predictive power for ocular volume. Sixty-seven adult subjects were scanned with a Siemens 3-T MRI scanner. Mean spherical error (MSE) (D) was measured with a Shin-Nippon autorefractor and a Zeiss IOLMaster used to measure (mm) axial length (AL), anterior chamber depth (ACD) and corneal radius (CR). Total ocular volume (TOV) was calculated from T2-weighted MRIs (voxel size 1.0 mm(3)) using an automatic voxel counting and shading algorithm. Each MR slice was subsequently edited manually in the axial, sagittal and coronal plane, the latter enabling location of the posterior pole of the crystalline lens and partitioning of TOV into anterior (AV) and posterior volume (PV) regions. Mean values (±SD) for MSE (D), AL (mm), ACD (mm) and CR (mm) were -2.62±3.83, 24.51±1.47, 3.55±0.34 and 7.75±0.28, respectively. Mean values (±SD) for TOV, AV and PV (mm(3)) were 8168.21±1141.86, 1099.40±139.24 and 7068.82±1134.05, respectively. TOV showed significant correlation with MSE, AL, PV (all p<0.001), CR (p=0.043) and ACD (p=0.024). Bar CR, the correlations were shown to be wholly attributable to variation in PV. Multiple linear regression indicated that the combination of AL and CR provided optimum R(2) values of 79.4% for TOV. Clinically useful estimations of ocular volume can be obtained from measurement of AL and CR. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  13. Genetic variation in California oaks

    Science.gov (United States)

    Constance I. Millar; Diane L. Delany; Lawrence A. Riggs

    1990-01-01

    In forestry the importance of genetic variation for successful reproduction, survival and growth has been widely documented for commercial conifers; until recently, little genetic work has been done on the California oaks. Even before the nature of genetic variation was scientifically investigated, its importance was suspected in operational forestry. Many failures of...

  14. Exploiting natural variation in Arabidopsis

    NARCIS (Netherlands)

    Molenaar, J.A.; Keurentjes, J.J.B.; Sanchez-Serrano, J.J.; Salinas, J.

    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

  15. General strongly nonlinear variational inequalities

    International Nuclear Information System (INIS)

    Siddiqi, A.H.; Ansari, Q.H.

    1990-07-01

    In this paper we develop iterative algorithms for finding approximate solutions for new classes of variational and quasi-variational inequalities which include, as special case, some known results in this field. It is shown that the solutions of the iterative schemes converge to the exact solutions. (author). 15 refs

  16. 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 homogeneou...

  17. Strongly nonlinear parabolic variational inequalities.

    Science.gov (United States)

    Browder, F E; Brézis, H

    1980-02-01

    An existence and uniqueness result is established for a general class of variational inequalities for parabolic partial differential equations of the form partial differentialu/ partial differentialt + A(u) + g(u) = f with g nondecreasing but satisfying no growth condition. The proof is based upon a type of compactness result for solutions of variational inequalities that should find a variety of other applications.

  18. 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

  19. VariVis: a visualisation toolkit for variation databases

    Directory of Open Access Journals (Sweden)

    Smith Timothy D

    2008-04-01

    Full Text Available Abstract Background With the completion of the Human Genome Project and recent advancements in mutation detection technologies, the volume of data available on genetic variations has risen considerably. These data are stored in online variation databases and provide important clues to the cause of diseases and potential side effects or resistance to drugs. However, the data presentation techniques employed by most of these databases make them difficult to use and understand. Results Here we present a visualisation toolkit that can be employed by online variation databases to generate graphical models of gene sequence with corresponding variations and their consequences. The VariVis software package can run on any web server capable of executing Perl CGI scripts and can interface with numerous Database Management Systems and "flat-file" data files. VariVis produces two easily understandable graphical depictions of any gene sequence and matches these with variant data. While developed with the goal of improving the utility of human variation databases, the VariVis package can be used in any variation database to enhance utilisation of, and access to, critical information.

  20. 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.

  1. Convex variational problems linear, nearly linear and anisotropic growth conditions

    CERN Document Server

    Bildhauer, Michael

    2003-01-01

    The author emphasizes a non-uniform ellipticity condition as the main approach to regularity theory for solutions of convex variational problems with different types of non-standard growth conditions. This volume first focuses on elliptic variational problems with linear growth conditions. Here the notion of a "solution" is not obvious and the point of view has to be changed several times in order to get some deeper insight. Then the smoothness properties of solutions to convex anisotropic variational problems with superlinear growth are studied. In spite of the fundamental differences, a non-uniform ellipticity condition serves as the main tool towards a unified view of the regularity theory for both kinds of problems.

  2. Viability Assessment Volume 1

    International Nuclear Information System (INIS)

    1998-01-01

    Since May 1996, under its draft Civilian Radioactive Waste Management Program Plan (DOE 1996), DOE has been carrying out a 5-year program of work to support the decision in 2001 by the Secretary of Energy on whether or not to recommend the site to the President. Part of this program was to address major unresolved technical issues and to complete an assessment of the viability of the Yucca Mountain site by 1998. Affirming the DOE plans, Congress directed DOE in the 1997 Energy and Water Development Appropriations Act to provide a viability assessment of the Yucca Mountain site to Congress and the President. This Viability Assessment (VA) document is the DOE report to Congress and the President. They are expected to use the VA to make an informed decision about program direction and funding. Drawing on 15 years of scientific investigation and design work at Yucca Mountain, the VA summarizes a large technical basis of field investigations, laboratory tests, models, analyses, and engineering, described in cited references. The VA identifies the major uncertainties relevant to the technical defensibility of DOE analyses and designs, the DOE approach to managing these uncertainties, and the status of work toward the site recommendation and LA. The VA also identifies DOE plans for the remaining work, and the estimated costs of completing an LA and constructing and operating a repository. The attention to uncertainties is important because DOE must evaluate how the repository will perform during the next 10,000 years or longer. Uncertainties exist because of variability in the natural (geologic and hydrologic) systems at Yucca Mountain and because of imperfect scientific understanding of the natural processes that might affect the repository system. This is Volume 1 and it covers, Introduction and Site Characteristics, includes a high-level summary of the results of the VA and some additional background information. (The overview is bound separately.) Section 1 of Volume

  3. The unfolding effects on the protein hydration shell and partial molar volume: a computational study.

    Science.gov (United States)

    Del Galdo, Sara; Amadei, Andrea

    2016-10-12

    In this paper we apply the computational analysis recently proposed by our group to characterize the solvation properties of a native protein in aqueous solution, and to four model aqueous solutions of globular proteins in their unfolded states thus characterizing the protein unfolded state hydration shell and quantitatively evaluating the protein unfolded state partial molar volumes. Moreover, by using both the native and unfolded protein partial molar volumes, we obtain the corresponding variations (unfolding partial molar volumes) to be compared with the available experimental estimates. We also reconstruct the temperature and pressure dependence of the unfolding partial molar volume of Myoglobin dissecting the structural and hydration effects involved in the process.

  4. 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....

  5. Prehospital tidal volume influences hospital tidal volume: A cohort study.

    Science.gov (United States)

    Stoltze, Andrew J; Wong, Terrence S; Harland, Karisa K; Ahmed, Azeemuddin; Fuller, Brian M; Mohr, Nicholas M

    2015-06-01

    The purposes of the study are to describe current practice of ventilation in a modern air medical system and to measure the association of ventilation strategy with subsequent ventilator care and acute respiratory distress syndrome (ARDS). Retrospective observational cohort study of intubated adult patients (n = 235) transported by a university-affiliated air medical transport service to a 711-bed tertiary academic center between July 2011 and May 2013. Low tidal volume ventilation was defined as tidal volumes less than or equal to 8 mL/kg predicted body weight. Multivariable regression was used to measure the association between prehospital tidal volume, hospital ventilation strategy, and ARDS. Most patients (57%) were ventilated solely with bag valve ventilation during transport. Mean tidal volume of mechanically ventilated patients was 8.6 mL/kg predicted body weight (SD, 0.2 mL/kg). Low tidal volume ventilation was used in 13% of patients. Patients receiving low tidal volume ventilation during air medical transport were more likely to receive low tidal volume ventilation in the emergency department (P tidal volume (P = .840). Low tidal volume ventilation was rare during air medical transport. Air transport ventilation strategy influenced subsequent ventilation but was not associated with ARDS. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Random volumes from matrices

    Energy Technology Data Exchange (ETDEWEB)

    Fukuma, Masafumi; Sugishita, Sotaro; Umeda, Naoya [Department of Physics, Kyoto University,Kitashirakawa Oiwake-cho, Kyoto 606-8502 (Japan)

    2015-07-17

    We propose a class of models which generate three-dimensional random volumes, where each configuration consists of triangles glued together along multiple hinges. The models have matrices as the dynamical variables and are characterized by semisimple associative algebras A. Although most of the diagrams represent configurations which are not manifolds, we show that the set of possible diagrams can be drastically reduced such that only (and all of the) three-dimensional manifolds with tetrahedral decompositions appear, by introducing a color structure and taking an appropriate large N limit. We examine the analytic properties when A is a matrix ring or a group ring, and show that the models with matrix ring have a novel strong-weak duality which interchanges the roles of triangles and hinges. We also give a brief comment on the relationship of our models with the colored tensor models.

  7. BNL volume H- source

    International Nuclear Information System (INIS)

    Prelec, K.; Alessi, J.G.

    1991-01-01

    The volume H minus ion source under development at Brookhaven is unique in that it has a toroidal plasma region, which feeds ions into the central extraction region through a conically shaped filter field. In pulsed operation, it produced 25 mA of H minus in a 1 cm 2 aperture, with an electron-to-H minus ratio of ∼ 3. At 19 mA, a normalized, 90% emittance of 0.44 π mm-mrad has been measured. Up to 50 mA has been extracted through a 1.87 cm 2 aperture. Although not designed for steady state operation, up to 6 mA has been extracted d.c. The addition of xenon to the discharge was found to improve the source output by 20--70%. The circular magnetic cusp field geometry was found to be more favorable than radial cusp fields. 4 refs., 5 figs

  8. 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...

  9. 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. Tra...... 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.......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...

  10. Pad-weighing test performed with standardized bladder volume

    DEFF Research Database (Denmark)

    Lose, G; Rosenkilde, P; Gammelgaard, J

    1988-01-01

    The result of the one-hour pad-weighing test proposed by the International Continence Society has been demonstrated to depend on the urine load during the test. To increase reproducibility of the pad-weighing test by minimizing the influence of variation in urine load the test was done with a sta...... 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....... 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...

  11. MRI definition of target volumes using fuzzy logic method for three-dimensional conformal radiation therapy

    International Nuclear Information System (INIS)

    Caudrelier, Jean-Michel; Vial, Stephane; Gibon, David; Kulik, Carine; Fournier, Charles; Castelain, Bernard; Coche-Dequeant, Bernard; Rousseau, Jean

    2003-01-01

    Purpose: Three-dimensional (3D) volume determination is one of the most important problems in conformal radiation therapy. Techniques of volume determination from tomographic medical imaging are usually based on two-dimensional (2D) contour definition with the result dependent on the segmentation method used, as well as on the user's manual procedure. The goal of this work is to describe and evaluate a new method that reduces the inaccuracies generally observed in the 2D contour definition and 3D volume reconstruction process. Methods and Materials: This new method has been developed by integrating the fuzziness in the 3D volume definition. It first defines semiautomatically a minimal 2D contour on each slice that definitely contains the volume and a maximal 2D contour that definitely does not contain the volume. The fuzziness region in between is processed using possibility functions in possibility theory. A volume of voxels, including the membership degree to the target volume, is then created on each slice axis, taking into account the slice position and slice profile. A resulting fuzzy volume is obtained after data fusion between multiorientation slices. Different studies have been designed to evaluate and compare this new method of target volume reconstruction and a classical reconstruction method. First, target definition accuracy and robustness were studied on phantom targets. Second, intra- and interobserver variations were studied on radiosurgery clinical cases. Results: The absolute volume errors are less than or equal to 1.5% for phantom volumes calculated by the fuzzy logic method, whereas the values obtained with the classical method are much larger than the actual volumes (absolute volume errors up to 72%). With increasing MRI slice thickness (1 mm to 8 mm), the phantom volumes calculated by the classical method are increasing exponentially with a maximum absolute error up to 300%. In contrast, the absolute volume errors are less than 12% for phantom

  12. Searching for God: Illness-Related Mortality Threats and Religious Search Volume in Google in 16 Nations.

    Science.gov (United States)

    Pelham, Brett W; Shimizu, Mitsuru; Arndt, Jamie; Carvallo, Mauricio; Solomon, Sheldon; Greenberg, Jeff

    2018-03-01

    We tested predictions about religiosity and terror management processes in 16 nations. Specifically, we examined weekly variation in Google search volume in each nation for 12 years (all weeks for which data were available). In all 16 nations, higher than usual weekly Google search volume for life-threatening illnesses (cancer, diabetes, and hypertension) predicted increases in search volume for religious content (e.g., God, Jesus, prayer) in the following week. This effect held up after controlling for (a) recent past and annual variation in religious search volume, (b) increases in search volume associated with religious holidays, and (c) variation in searches for a non-life-threatening illness ("sore throat"). Terror management threat reduction processes appear to occur across the globe. Furthermore, they may occur over much longer periods than those studied in the laboratory. Managing fears of death via religious belief regulation appears to be culturally pervasive.

  13. Observer variation in skeletal radiology

    Energy Technology Data Exchange (ETDEWEB)

    Cockshott, W.P.; Park, W.M.

    1983-08-01

    The factors that affect observer variation in bone radiology are analysed from data in the literature and on the basis of studies carried out at McMaster University on the hands and sacroiliac joints. A plea is made for presenting results in terms of Kappa statistics so that agreement due purely to chance is eliminated. In the conclusions the main variables that affect concordance are listed so that strategies can be developed to reduce observer variation. This is important in serial studies to ensure that the observer variations are smaller than the effect one wishes to measure.

  14. Determination of blood volume by pulse CO-oximetry

    International Nuclear Information System (INIS)

    Lalande, S; Kelsey, J W; Joyner, M J; Johnson, B D

    2012-01-01

    The objective of this study was to determine whether changes in carboxyhaemoglobin (COHb) saturation following carbon monoxide (CO) rebreathing can be accurately detected by pulse CO-oximetry in order to determine blood volume. Noninvasive measurements of carboxyhaemoglobin saturation (SpCO) were continuously monitored by pulse CO-oximetry before, during and following 2 min of CO rebreathing. Reproducibility and accuracy of noninvasive blood volume measurements were determined in 16 healthy non-smoking individuals (15 males, age: 28 ± 2 years, body mass index: 25.4 ± 0.6 kg m −2 ) through comparison with blood volume measurements calculated from invasive measurements of COHb saturation. The coefficient of variation for noninvasive blood volume measurements performed on separate days was 15.1% which decreases to 9.1% when measurements were performed on the same day. Changes in COHb saturation and SpCO following CO rebreathing were strongly correlated (r = 0.90, p < 0.01), resulting in a significant correlation between invasive and noninvasive blood volume measurements (r = 0.83, p = 0.02). Changes in SpCO following CO rebreathing can be accurately detected by pulse CO-oximetry, which could potentially provide a simplified, convenient and reproducible method to rapidly determine blood volume in healthy individuals

  15. Experimental Pressure-Volume diagrams of scroll compressors

    OpenAIRE

    Picavet, Alain; Ginies, Pierre

    2014-01-01

    This paper presents the results of tests led with scroll compressors to establish pressure-volume diagrams. Two compressors were thinly instrumented with pressure and displacement sensors so as to follow the whole compression process, from suction to exhaust. A gear coder was set to mark off the closing and opening of gas pockets, and to study the speed variations occurring during a single rotation. These tests help to understand the various phenomena met in a compressor, such as back-flow, o...

  16. 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

  17. Inter- and intra-observer variation in soft-tissue sarcoma target definition.

    Science.gov (United States)

    Roberge, D; Skamene, T; Turcotte, R E; Powell, T; Saran, N; Freeman, C

    2011-08-01

    To evaluate inter- and intra-observer variability in gross tumor volume definition for adult limb/trunk soft tissue sarcomas. Imaging studies of 15 patients previously treated with preoperative radiation were used in this study. Five physicians (radiation oncologists, orthopedic surgeons and a musculoskeletal radiologist) were asked to contour each of the 15 tumors on T1-weighted, gadolinium-enhanced magnetic resonance images. These contours were drawn twice by each physician. The volume and center of mass coordinates for each gross tumor volume were extracted and a Boolean analysis was performed to measure the degree of volume overlap. The median standard deviation in gross tumor volumes across observers was 6.1% of the average volume (range: 1.8%-24.9%). There was remarkably little variation in the 3D position of the gross tumor volume center of mass. For the 15 patients, the standard deviation of the 3D distance between centers of mass ranged from 0.06 mm to 1.7 mm (median 0.1mm). Boolean analysis demonstrated that 53% to 90% of the gross tumor volume was common to all observers (median overlap: 79%). The standard deviation in gross tumor volumes on repeat contouring was 4.8% (range: 0.1-14.4%) with a standard deviation change in the position of the center of mass of 0.4mm (range: 0mm-2.6mm) and a median overlap of 93% (range: 73%-98%). Although significant inter-observer differences were seen in gross tumor volume definition of adult soft-tissue sarcoma, the center of mass of these volumes was remarkably consistent. Variations in volume definition did not correlate with tumor size. Radiation oncologists should not hesitate to review their contours with a colleague (surgeon, radiologist or fellow radiation oncologist) to ensure that they are not outliers in sarcoma gross tumor volume definition. Protocols should take into account variations in volume definition when considering tighter clinical target volumes. Copyright © 2011 Société française de radioth

  18. Paleosecular variations from lake sediments

    International Nuclear Information System (INIS)

    Lund, S.P.; Banerjee, S.K.

    1979-01-01

    Data are presented on the secular variations of the magnetization of wet and dry lake sediments for 17 North American locations. The usefullness of this data in terms of the geomagnetic field is discussed

  19. Diural TSH variations in hypothyroidism.

    Science.gov (United States)

    Weeke, J; Laurberg, P

    1976-07-01

    There is a circadian variation in serum TSH in euthyroid subjects. A similar diurnal variation has been demonstrated in patients with hypothyroidism. In the present study the 24-hour pattern of serum TSH was investigated in eight patients with hypothyroidism of varying severity and in five hypothyroid patients treated with thyroxine (T4). There was a circadian variation in serum TSH in patients with hypothyroidism of moderate degree, and in patients treated for severe hypothyrodism with thyroxine. The pattern was similar to that found in normal subjects, i.e., low TSH levels in the daytime and higher levels at night. In severely hypothyroid patients, no diurnal variation in serum TSH was observed. A practical consequence is that blood samples for TSH measurements in patients with moderately elevated TSH levels are best taken after 1100 h, when the low day levels are reached.

  20. 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

  1. Volume and Surface-Enhanced Volume Negative Ion Sources

    International Nuclear Information System (INIS)

    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. (author)

  2. 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

  3. Thematic Composition and Idiom Variation

    Directory of Open Access Journals (Sweden)

    Cserép Attila

    2017-11-01

    Full Text Available The Corpus of Contemporary American English (COCA has been studied to retrieve variant forms of semantically decomposable idioms that have no thematic composition for the purpose of determining whether thematic composition is a necessary criterion for idiom variation as claimed by Horn (2003. The syntactic variants searched for include passive, raising, tough-movement, relative clauses and wh-questions. Horn’s (2003 hypothesis is not fully confirmed, as some variation has been found.

  4. A compiler for variational forms

    OpenAIRE

    Kirby, Robert C.; Logg, Anders

    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 s...

  5. 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.

  6. 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.

  7. Variational integrators for electric circuits

    International Nuclear Information System (INIS)

    Ober-Blöbaum, Sina; Tao, Molei; Cheng, Mulin; Owhadi, Houman; Marsden, Jerrold E.

    2013-01-01

    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

  8. 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 ea...

  9. Pragmatics & Language Learning. Volume 14

    Science.gov (United States)

    Bardovi-Harlig, Kathleen, Ed.; Félix-Brasdefer, J. César, Ed.

    2016-01-01

    This volume contains a selection of papers presented at the 2014 International Conference of Pragmatics and Language Learning at Indiana University. It includes fourteen papers on a variety of topics, with a diversity of first and second languages, and a wide range of methods used to collect pragmatic data in L2 and FL settings. This volume is…

  10. Determination of clothing microclimate volume

    NARCIS (Netherlands)

    Daanen, Hein; Hatcher, Kent; Havenith, George

    2005-01-01

    The average air layer thickness between human skin and clothing is an important factor in heat transfer. The trapped volume between skin and clothing is an estimator for everage air layer thickness. Several techniques are available to determine trapped volume. This study investigates the reliability

  11. 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.

  12. 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.

  13. Surface area-volume ratios in insects.

    Science.gov (United States)

    Kühsel, Sara; Brückner, Adrian; Schmelzle, Sebastian; Heethoff, Michael; Blüthgen, Nico

    2017-10-01

    Body mass, volume and surface area are important for many aspects of the physiology and performance of species. Whereas body mass scaling received a lot of attention in the literature, surface areas of animals have not been measured explicitly in this context. We quantified surface area-volume (SA/V) ratios for the first time using 3D surface models based on a structured light scanning method for 126 species of pollinating insects from 4 orders (Diptera, Hymenoptera, Lepidoptera, and Coleoptera). Water loss of 67 species was measured gravimetrically at very dry conditions for 2 h at 15 and 30 °C to demonstrate the applicability of the new 3D surface measurements and relevance for predicting the performance of insects. Quantified SA/V ratios significantly explained the variation in water loss across species, both directly or after accounting for isometric scaling (residuals of the SA/V ∼ mass 2/3 relationship). Small insects with a proportionally larger surface area had the highest water loss rates. Surface scans of insects to quantify allometric SA/V ratios thus provide a promising method to predict physiological responses, improving the potential of body mass isometry alone that assume geometric similarity. © 2016 Institute of Zoology, Chinese Academy of Sciences.

  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. Subjective visual vertical before and after treatment of a BPPV episode.

    Science.gov (United States)

    Faralli, Mario; Manzari, Leonardo; Panichi, Roberto; Botti, Fabio; Ricci, Giampietro; Longari, Fabrizio; Pettorossi, Vito Enrico

    2011-06-01

    The study analyses the behavior of subjective visual vertical (SVV) in benign paroxysmal positional vertigo (BPPV) before and after treatment, and offers a clinical-pathogenic interpretation. We studied 30 consecutive patients with BPPV of the posterior semicircular canal treated with the Epley repositioning maneuver. SVV was determined at three different stages: at the time of diagnosis (1st test), after the repositioning maneuver (2nd test), and then 7 days after the resolution of the clinical picture (3rd test). The main study parameter was represented by the mean of 6 consecutive measurements (SVV(0)) for each patient. SVV was also examined in 20 healthy subjects, who represented the control group. The comparison between mean values and standard deviations showed a statistical significance of p<0.05. During the first test, the degree of deviation of SVV was significantly higher in the patient group than in the control group. Tilting towards the affected side was observed in all cases. The 2nd test showed an inversion in the orientation of SVV in 16 patients, and as a result of the Epley maneuver there was a statistically significant variation in SVV(0) values in 20 patients with respect to the previous test (2nd test vs. 1st test). This involved 87% (23 patients) of those who then had a negative Dix-Hallpike test, and none of the ones in whom paroxysmal positional nystagmus persisted. Lastly, no differences emerged in the behavior of the patient group vs. the control group during the third test. SVV is often altered during active BPPV. The degree of otolithic dysfunction is never high and, in all cases, it is brief in duration. Tilting towards the dysfunctional side is essentially a constant in untreated BPPV. This could be due to a substantial loss of otoconia, with a decrease in the density and specific weight of the macula, and thus hypofunction of the receptor. The observation of a significant variation in SVV after therapeutic maneuvers has a favorable

  16. 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.

  17. 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.

  18. Existence of evolutionary variational solutions via the calculus of variations

    Science.gov (United States)

    Bögelein, Verena; Duzaar, Frank; Marcellini, Paolo

    In this paper we introduce a purely variational approach to time dependent problems, yielding the existence of global parabolic minimizers, that is ∫0T ∫Ω [uṡ∂tφ+f(x,Du)] dx dt⩽∫0T ∫Ω f(x,Du+Dφ) dx dt, whenever T>0 and φ∈C0∞(Ω×(0,T),RN). For the integrand f:Ω×R→[0,∞] we merely assume convexity with respect to the gradient variable and coercivity. These evolutionary variational solutions are obtained as limits of maps depending on space and time minimizing certain convex variational functionals. In the simplest situation, with some growth conditions on f, the method provides the existence of global weak solutions to Cauchy-Dirichlet problems of parabolic systems of the type ∂tu-divDξf(x,Du)=0 in Ω×(0,∞).

  19. Dose, time and volume effects in interstitial radiation therapy

    International Nuclear Information System (INIS)

    Burgers, J.M.V.

    1982-01-01

    This study presents the main features and uncertainties of interstitial therapy and was undertaken to examine whether differences could be found in different clinical situations treated by interstitial implants with removable sources, that were not simply related to dose. In chapter 2, dating from 1978, continuous low dose rate irradiation is discussed from the radiobiological point of view together with some points related to variation in dose rate. A benefit of continuous low dose rate irradiation could be surmised in a few situations with special cell-kinetic properties. The problem of dose specification, the sharp dose gradient and other volume characteristics are discussed in chapter 3. Possible adjustments to variations in dose rate are discussed in chapter 4. The clinical material is reviewed in chapter 5, including aspects of dose specification, dose fall-off and variation in dose rate. The general discussion and conclusions are given in chapter 6. (Auth.)

  20. 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

  1. Atlas of temporal variations - interdisciplinary scientific work

    Science.gov (United States)

    Gamburtsev, A. G.; Oleinik, O. V.

    2003-04-01

    The year 2002 will culminate in the publication of the third volume of the fundamental interdisciplinary work "Atlas of Temporal Variations in Natural, Anthropogenic and Social Processes", which now will comprise three volumes (1994, 1998, 2002). The Atlas has pooled the information on the main peculiarities of processes' behaviour in various natural and humanitarian spheres over the widest temporal and spatial range. The main scientific goal of the work consists in discovering the behaviour pattern of natural, anthropogenic and social processes and the cause and effect links between them. Thus, the Atlas contains extensive comparative generalisation from the vastly different data. For one thing, it is a fundamental work on the law-governed nature of evolution in natural and social spheres; for another, it can be used as a reference book and valuable source of information for research in different directions. The authors seek to treat every piece of information as part of an integrated whole. When analysing the data, we operate on the premise that surrounding nature, society and their elements are open dynamic systems. Systems of this kind exhibit non-linear characteristics and a tendency towards ordered and chaotic behaviour. These features are revealed in the course of the analysis of time series. The data processing procedures applied are unified, all processes being generally expressed in terms of their time series and time-spectral diagrams. The technique is aimed at determination of investigated parameters' rhythms and the analysis of their evolution. This approach enables us to show the dynamics of processes occurring in absolutely dissimilar objects and performs their comparative analysis, with particular emphasis placed on rhythms and trends. As a result successions of illustrations are obtained and formed the basis of the Atlas. The Atlas covers processes that occur in objects belonging to the lithosphere, atmosphere, hydrosphere and social sphere as well

  2. Variations of free gas content in water during pressure fluctuations

    International Nuclear Information System (INIS)

    Keller, A.; Zielke, W.

    1977-01-01

    In this paper an experimental programme is described in order to determine the influence of the cavitation nuclei distribution on cavitation inception. This programme has been used to measure air bubbles dimensions and number and particularly to determine the influence of quick pressure variations on the size on the number of bubbles in a pipe. An optical device counting scattered light is used as a measuring technique. Gas bubbles go through an optical control volume where they receive a high intensity light beam and scatter the light, then led to a photomultiplier; the signals are sorted and counted according to their size. If the number of nuclei, the dimensions of the control volume and the velocity of the water are known, it is possible to determine bubbles concentrations and the bulk modulus of the water. This measuring technique has been applied to a flow in a 140 mm diameter pipe with quick pressure variations from 2 bar to 0-10 bar. During the variations, the void fraction depends on the Reynolds number of the flow and on the gas content of the water. The bulk modulus has been computed with different conditions. Most results concern pressures slightly over the vapor pressure. Air content has a strong influence on cavitation and on water compressibility after a vapor cavity collapse

  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. Interfractional Target Variations for Partial Breast Irradiation

    International Nuclear Information System (INIS)

    Ahunbay, Ergun E.; Robbins, Jared; Christian, Robert; Godley, Andrew; White, Julia; Li, X. Allen

    2012-01-01

    Purpose: In this work, we quantify the interfractional variations in the shape of the clinical target volume (CTV) by analyzing the daily CT data acquired during CT-guided partial breast irradiation (PBI) and compare the effectiveness of various repositioning alignment strategies considered to account for the variations. Methods and Materials: The daily CT data for 13 breast cancer patients treated with PBI in either prone (10 patients) or supine (3 patients) with daily kV CT guidance using CT on Rails (CTVision, Siemens, Malvern, PA) were analyzed. For approximately 25 points on the surface of the CTV, deformation vectors were calculated by means of deformable image registration and verified by visual inspection. These were used to calculate the distances along surface normals (DSN), which directly related to the required margin expansions for each point. The DSN values were determined for seven alignment methods based on volumetric imaging and also two-dimensional projections (portal imaging). Results: The margin expansion necessary to cover 99% of all points for all days was 2.7 mm when utilizing the alignment method based on deformation field data (the best alignment method). The center-of-mass based alignment yielded slightly worse results (a margin of 4.0 mm), and shifts obtained by operator placement (7.9 mm), two-dimensional-based methods (7.0–10.1 mm), and skin marks (13.9 mm) required even larger margin expansions. Target shrinkage was evident for most days by the negative values of DSN. Even with the best alignment, the range of DSN values could be as high as 7 mm, resulting in a large amount of normal tissue irradiation, unless adaptive replanning is employed. Conclusion: The appropriate alignment method is important to minimize the margin requirement to cover the significant interfractional target deformations observed during PBI. The amount of normal tissue unnecessarily irradiated is still not insignificant, and can be minimized if adaptive

  5. Understanding human DNA sequence variation.

    Science.gov (United States)

    Kidd, K K; Pakstis, A J; Speed, W C; Kidd, J R

    2004-01-01

    Over the past century researchers have identified normal genetic variation and studied that variation in diverse human populations to determine the amounts and distributions of that variation. That information is being used to develop an understanding of the demographic histories of the different populations and the species as a whole, among other studies. With the advent of DNA-based markers in the last quarter century, these studies have accelerated. One of the challenges for the next century is to understand that variation. One component of that understanding will be population genetics. We present here examples of many of the ways these new data can be analyzed from a population perspective using results from our laboratory on multiple individual DNA-based polymorphisms, many clustered in haplotypes, studied in multiple populations representing all major geographic regions of the world. These data support an "out of Africa" hypothesis for human dispersal around the world and begin to refine the understanding of population structures and genetic relationships. We are also developing baseline information against which we can compare findings at different loci to aid in the identification of loci subject, now and in the past, to selection (directional or balancing). We do not yet have a comprehensive understanding of the extensive variation in the human genome, but some of that understanding is coming from population genetics.

  6. Normal variation of hepatic artery

    International Nuclear Information System (INIS)

    Kim, Inn; Nam, Myung Hyun; Rhim, Hyun Chul; Koh, Byung Hee; Seo, Heung Suk; Kim, Soon Yong

    1987-01-01

    This study was an analyses of blood supply of the liver in 125 patients who received hepatic arteriography and abdominal aortography from Jan. 1984 to Dec. 1986 at the Department of Radiology of Hanyang University Hospital. A. Variations in extrahepatic arteries: 1. The normal extrahepatic artery pattern occurred in 106 of 125 cases (84.8%) ; Right hepatic and left hepatic arteries arising from the hepatic artery proper and hepatic artery proper arising from the common hepatic artery. 2. The most common type of variation of extrahepatic artery was replaced right hepatic artery from superior mesenteric artery: 6 of 125 cases (4.8%). B. Variations in intrahepatic arteries: 1. The normal intrahepatic artery pattern occurred in 83 of 125 cases (66.4%). Right hepatic and left hepatic arteries arising from the hepatic artery proper and middle hepatic artery arising from lower portion of the umbilical point of left hepatic artery. 2. The most common variation of intrahepatic arteries was middle hepatic artery. 3. Among the variation of middle hepatic artery; Right, middle and left hepatic arteries arising from the same location at the hepatic artery proper was the most common type; 17 of 125 cases (13.6%)

  7. 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.

  8. Postprandial hepatic volume change: spiral CT evaluation in case of liver cirrhosis

    International Nuclear Information System (INIS)

    Rho, Kwang Suk; Moon, Jang Il; Ko, Myong Kwan; Byun, Joo Nam; Kim, Young Suk; Kim, Young Chol; Oh, Jae Hee

    1999-01-01

    To investigate the usefulness of evaluating liver cirrhosis through the measurement of liver volume. In a control group(20 normal subjects) and 20 cirrhotic patients, variations in liver volume before and after a meal were obtained. A case-control study was conducted between the two groups. In the control group, the range of increased liver volume after the meal was 67-186ml. Mean increased liver volume was 119.3ml, the range of percentage increase was 6-12.4% and the mean percentage increase was 9.89%. In cirrhotic patients, the range of increased liver volume after the meal was 1-20ml. Mean increase liver volume was 6.9ml, the range of percentage increase was 0-1.9% and the mean percentage increase was 0.65%. Compared with the control group, cirrhotic patients showed a much smaller increase in liver volume(p<0.01). Difference in variation of liver volume between a control group and cirrhotic patients before and after a meal can be used for the evaluation of liver cirrhosis

  9. 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.

  10. 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.

  11. Variational principles for nonpotential operators

    CERN Document Server

    Filippov, V M

    1989-01-01

    This book develops a variational method for solving linear equations with B-symmetric and B-positive operators and generalizes the method to nonlinear equations with nonpotential operators. The author carries out a constructive extension of the variational method to "nonvariational" equations (including parabolic equations) in classes of functionals which differ from the Euler-Lagrange functionals. In this connection, some new functions spaces are considered. Intended for mathematicians working in the areas of functional analysis and differential equations, this book would also prove useful for researchers in other areas and students in advanced courses who use variational methods in solving linear and nonlinear boundary value problems in continuum mechanics and theoretical physics.

  12. 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 ...

  13. 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...

  14. 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.

  15. 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,…

  16. Stem anatomy variation in cottonwood

    Science.gov (United States)

    A.N. Foulger; J. Hacskaylo

    1968-01-01

    Investigations of mineral nutrient-tree growth relationships have dealt mainly with associations involving foliage composition, root formation, or volume production of wood. Few studies have been concerned with changes in wood anatomy associated with element deficiency. In 1949 Davis reported that calcium deficiency was accompanied by a reduction of primary tissue and...

  17. Testicular Volume: Size Does Matter

    International Nuclear Information System (INIS)

    Reyes Lobo, Alexander; Segovia Fuentes, Javier; Cerpa Reyes, Edgar

    2011-01-01

    Testicular volume is critical for semen production and, consequently, for fertility. Hence the importance of knowing the normal size ranges and the different methods for calculating size, in order to classify patients at risk and refer them for appropriate management. Ultrasound is the first-line diagnostic method for the evaluation of testicular pathology, and it is also the best tool for estimating the volume of both testicles, bearing in mind that a testicular volume below 15 cc results in fertility problems. Although there are many causes of infertility, varicocele is undoubtedly the most important of all, because of its frequency and because it is amenable to curative surgical treatment.

  18. 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...

  19. 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....

  20. 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.

  1. Structure variations of carbonizing lignin

    International Nuclear Information System (INIS)

    Otani, C.; Polidoro, H.A.; Otani, S.; Craievich, A.F.

    1984-01-01

    The studied lignin is a by-product of the process of ethanol production from eucaliptus. It was heat-treated under inert atmosphere conditions at increasing temperatures from 300C up to 2400C. The structural variations were studied by wide-angle X-ray diffraction, small-angle X-ray scattering and infrared absorption spectroscopy. The bulk and 'real' density of the compacted materials have also been determined as functions of the final temperature. These experimental results enabled us to establish a mechanism of structure variation based on the formation of a turbostratic graphite-like and porous structure within the initially amorphous lignin matrix. (Author) [pt

  2. Biological variation of cystatin C

    DEFF Research Database (Denmark)

    Reinhard, Mark; Erlandsen, Erland; Randers, Else

    2009-01-01

    Introduction: Cystatin C has been investigated as a marker of the glomerular filtration rate. However, previous studies have reported conflicting results concerning the biological variation of cystatin C. The aim of the present study was to evaluate the biological variation of cystatin C...... in comparison to creatinine. Methods: Eight weekly morning blood samples were taken from twenty healthy volunteers (13 females, 7 males) aged 25-61 years. Mean creatinine clearance was 99.7 ml/min/1.73 m2 (range 61.8-139.5) and mean body mass index 23.9 kg/m2 (range 20.3-28.7). A total of 155 samples were...

  3. Variational principle in quantum mechanics

    International Nuclear Information System (INIS)

    Popiez, L.

    1986-01-01

    The variational principle in a standard, path integral formulation of quantum mechanics (as proposed by Dirac and Feynman) appears only in the context of a classical limit n to 0 and manifests itself through the method of abstract stationary phase. Symbolically it means that a probability amplitude averaged over trajectories denotes a classical evolution operator for points in a configuration space. There exists, however, the formulation of quantum dynamics in which variational priniple is one of basic postulates. It is explained that the translation between stochastic and quantum mechanics in this case can be understood as in Nelson's stochastic mechanics

  4. A survey of variational principles

    International Nuclear Information System (INIS)

    Lewins, J.D.

    1993-01-01

    The survey of variational principles has ranged widely from its starting point in the Lagrange multiplier to optimisation principles. In an age of digital computation, these classic methods can be adapted to improve such calculations. We emphasize particularly the advantage of basing finite element methods on variational principles, especially if, as maximum and minimum principles, these can provide bounds and hence estimates of accuracy. The non-symmetric (and hence stationary rather than extremum principles) are seen however to play a significant role in optimisation theory. (Orig./A.B.)

  5. PENGARUH FRAKSI VOLUME PENGUAT TERHADAP KEKUATAN LENTUR GREEN COMPOSITE UNTUK APLIKASI PADA BODI KENDARAAN

    OpenAIRE

    Perdana, Mastariyanto

    2016-01-01

    Composites are one of material be used in engineering field. This is due the composites has light weight and relatively strong properties. The synthesis fiber-based composites reduces to obtain environmental friendly properties. This research use hybrid fiber which consist of calcium carbonate (CaCO3) powder and bagasse fiber. Matrix used is resin polyester. Variation of volume fraction between bagasse and calcium carbonate powder are 10:20, 15:15 and 20:10 respectively. Volume fraction of hy...

  6. Volume measurement variability in three-dimensional high-frequency ultrasound images of murine liver metastases

    International Nuclear Information System (INIS)

    Wirtzfeld, L A; Graham, K C; Groom, A C; MacDonald, I C; Chambers, A F; Fenster, A; Lacefield, J C

    2006-01-01

    The identification and quantification of tumour volume measurement variability is imperative for proper study design of longitudinal non-invasive imaging of pre-clinical mouse models of cancer. Measurement variability will dictate the minimum detectable volume change, which in turn influences the scheduling of imaging sessions and the interpretation of observed changes in tumour volume. In this paper, variability is quantified for tumour volume measurements from 3D high-frequency ultrasound images of murine liver metastases. Experimental B16F1 liver metastases were analysed in different size ranges including less than 1 mm 3 , 1-4 mm 3 , 4-8 mm 3 and 8-70 mm 3 . The intra- and inter-observer repeatability was high over a large range of tumour volumes, but the coefficients of variation (COV) varied over the volume ranges. The minimum and maximum intra-observer COV were 4% and 14% for the 1-4 mm 3 and 3 tumours, respectively. For tumour volumes measured by segmenting parallel planes, the maximum inter-slice distance that maintained acceptable measurement variability increased from 100 to 600 μm as tumour volume increased. Comparison of free breathing versus ventilated animals demonstrated that respiratory motion did not significantly change the measured volume. These results enable design of more efficient imaging studies by using the measured variability to estimate the time required to observe a significant change in tumour volume

  7. 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...

  8. Quantification of Prostate and Seminal Vesicle Interfraction Variation During IMRT

    International Nuclear Information System (INIS)

    Frank, Steven J.; Dong Lei; Kudchadker, Rajat J.; De Crevoisier, Renaud; Lee, Andrew K.; Cheung, Rex; Choi, Seungtaek; O'Daniel, Jennifer; Tucker, Susan L.; Wang He; Kuban, Deborah A.

    2008-01-01

    Purpose: To quantify the interfraction variability in prostate and seminal vesicle (SV) positions during a course of intensity-modulated radiotherapy (IMRT) using an integrated computed tomography (CT)-linear accelerator system and to assess the impact of rectal and bladder volume changes. Methods and Materials: We studied 15 patients who had undergone IMRT for prostate carcinoma. Patients had one pretreatment planning CT scan followed by three in-room CT scans per week using a CT-on-rails system. The prostate, bladder, rectum, and pelvic bony anatomy were contoured in 369 CT scans. Using the planning CT scan as a reference, the volumetric and positional changes were analyzed in the subsequent CT scans. Results: For all 15 patients, the mean systematic internal prostate and SV variation was 0.1 ± 4.1 mm and 1.2 ± 7.3 mm in the anteroposterior axis, -0.5 ± 2.9 mm and -0.7 ± 4.5 mm in the superoinferior axis, and 0.2 ± 0.9 mm and -0.9 ± 1.9 mm in the lateral axis, respectively. The mean magnitude of the three-dimensional displacement vector was 4.6 ± 3.5 mm for the prostate and 7.6 ± 4.7 mm for the SVs. The rectal and bladder volume changes during treatment correlated with the anterior and superior displacement of the prostate and SVs. Conclusion: The dominant prostate and SV variations occurred in the anteroposterior and superoinferior directions. The systematic prostate and SV variation between the treatment planning CT and daily therapy as a result of the rectal and bladder volume changes emphasizes the need for daily directed target localization and/or immobilization techniques

  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. 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...

  11. Human gallbladder pressure and volume

    DEFF Research Database (Denmark)

    Borly, L; Højgaard, L; Grønvall, S

    1996-01-01

    volume with only slight changes in intraluminal pressure (n = 4). Except for the zero drift, this piece of equipment seemed to fulfil the requirements of being able to measure pressure in the GB. In vivo measurements showed a good clinical reproducibility of the method, and also that respiration...... influenced by respiration (n = 8) and the pressure seems to be higher in the sitting position than in the supine position (n = 5). Cystic duct opening pressure was 10.4, 11.2 and 16.8 mmHg (n = 3). Pressure-volume responses showed that the GB up to a certain volume could accommodate increases in intraluminal...... and patient posture influenced the pressure measurements. Further, a GB pressure-volume relationship was demonstrated, and the possibility of a cystic duct opening pressure was described....

  12. Measurement, variation, and scaling of osteocyte lacunae: a case study in birds.

    Science.gov (United States)

    D'Emic, Michael D; Benson, Roger B J

    2013-11-01

    Basic issues surrounding osteocyte biology are still poorly understood, including the variability of osteocyte morphology within and among bones, individuals, and species. Several studies have suggested that the volume or shape of osteocytes (or their lacunae) is related to bone and/or organismal growth rate or metabolism, but the nature of this relationship, if any, is unclear. Furthermore, several studies have linked osteocyte lacuna volume with genome size or growth rate and suggested that osteocyte lacuna volume is unrelated to body size. Herein the scaling of osteocyte lacuna volume with body mass, growth and basal metabolic rates, genome size, and red blood cell size is examined using a broad sample of extant birds within a phylogenetic framework. Over 12,000 osteocyte lacuna axes were measured in a variety of bones from 34 avian and four non-avian dinosaur species. Osteocyte lacunae in parallel-fibered bone are scalene ellipsoids; their morphology and volume cannot be reliably estimated from any single thin section, and using a prolate ellipsoid model to estimate osteocyte lacuna volume results in a substantial (ca. 2-7 times) underestimate relative to true lacunar volume. Orthogonal thin sections reveal that in birds, even when only observing parallel-fibered, primary, cortical bone, intra-skeletal variation in osteocyte lacuna volume and shape is very high (volumes vary by a factor of 5.4 among different bones), whereas variation among homologous bones of the same species is low (1.2-44%; mean=12%). Ordinary and phylogenetically informed bivariate and multiple regressions demonstrate that in birds, osteocyte volume scales significantly but weakly with body mass and mass-specific basal metabolic rate and moderately with genome size, but not with erythrocyte size. Avian whole-body growth rate and osteocyte lacuna volume are weakly and inversely related. Finally, we present the first three-dimensionally calculated osteocyte volumes for several non

  13. Interfractional changes in tumour volume and position during entire radiotherapy courses for lung cancer with respiratory gating and image guidance

    DEFF Research Database (Denmark)

    Juhler-Nøttrup, Trine; Korreman, Stine Sofia; Pedersen, Anders N

    2008-01-01

    were contoured on each CT scan to evaluate the variations in volumes and position. The lung tumours and the mediastinal tumours were contoured separately. The positional variations were measured as 3D mobility vectors and correlated to matching of the scans using the two different strategies. RESULTS......-87% when matched using bony landmarks and 70-76% when matched using skin tattoos. The overlap of the mediastinal tumours were 60-65% and 41-47%, respectively. CONCLUSIONS: Despite the use of gating the tumours varied considerably, regarding both position and volume. The variations in position were...

  14. Energy and Environment : volume 1

    OpenAIRE

    ANDRE, Michel; SAMARAS, Zissis; JACOB, Bernard

    2016-01-01

    This book is part of a set of six books called the 'Research for Innovative Transports' set. This collection presents an update of the latest academic and applied research, case studies, best practices and user perspectives on transport carried out in Europe and worldwide. The volumes are made up of a selection of the best papers presented at TRA2014. In this volume 1, recent research works are reported around the triptych : 'transport, energy and environment', which demonstrates that vehicl...

  15. Variational linear algebraic equations method

    International Nuclear Information System (INIS)

    Moiseiwitsch, B.L.

    1982-01-01

    A modification of the linear algebraic equations method is described which ensures a variational bound on the phaseshifts for potentials having a definite sign at all points. The method is illustrated by the elastic scattering of s-wave electrons by the static field of atomic hydrogen. (author)

  16. Visualization of Variation and Variability

    NARCIS (Netherlands)

    Busking, S.

    2014-01-01

    As datasets grow in size and complexity, the importance of comparison as a tool for analysis is growing. We define comparison as the act of analyzing variation or variability based on two or more specific instances of the data. This thesis explores a number of cases spread across the range of

  17. Regularization of Nonmonotone Variational Inequalities

    International Nuclear Information System (INIS)

    Konnov, Igor V.; Ali, M.S.S.; Mazurkevich, E.O.

    2006-01-01

    In this paper we extend the Tikhonov-Browder regularization scheme from monotone to rather a general class of nonmonotone multivalued variational inequalities. We show that their convergence conditions hold for some classes of perfectly and nonperfectly competitive economic equilibrium problems

  18. 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

  19. On quadratic variation of martingales

    Indian Academy of Sciences (India)

    On quadratic variation of martingales. 459. The proof relied on the theory of stochastic integration. Subsequently, in Karandikar. [4], the formula was derived using only Doob's maximal inequality. Thus this could be the starting point for the development of stochastic calculus for continuous semimartingales without bringing in ...

  20. 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...

  1. Linking numbers and variational method

    International Nuclear Information System (INIS)

    Oda, I.; Yahikozawa, S.

    1989-09-01

    The ordinary and generalized linking numbers for two surfaces of dimension p and n-p-1 in an n dimensional manifold are derived. We use a variational method based on the properties of topological quantum field theory in order to derive them. (author). 13 refs, 2 figs

  2. Spatial variation in messaging effects

    Science.gov (United States)

    Warshaw, Christopher

    2018-05-01

    There is large geographic variation in the public's views about climate change in the United States. Research now shows that climate messages can influence public beliefs about the scientific consensus on climate change, particularly in the places that are initially more skeptical.

  3. 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.

  4. 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.

  5. Variational analysis of regular mappings theory and applications

    CERN Document Server

    Ioffe, Alexander D

    2017-01-01

    This monograph offers the first systematic account of (metric) regularity theory in variational analysis. It presents new developments alongside classical results and demonstrates the power of the theory through applications to various problems in analysis and optimization theory. The origins of metric regularity theory can be traced back to a series of fundamental ideas and results of nonlinear functional analysis and global analysis centered around problems of existence and stability of solutions of nonlinear equations. In variational analysis, regularity theory goes far beyond the classical setting and is also concerned with non-differentiable and multi-valued operators. The present volume explores all basic aspects of the theory, from the most general problems for mappings between metric spaces to those connected with fairly concrete and important classes of operators acting in Banach and finite dimensional spaces. Written by a leading expert in the field, the book covers new and powerful techniques, whic...

  6. Newton-type methods for optimization and variational problems

    CERN Document Server

    Izmailov, Alexey F

    2014-01-01

    This book presents comprehensive state-of-the-art theoretical analysis of the fundamental Newtonian and Newtonian-related approaches to solving optimization and variational problems. A central focus is the relationship between the basic Newton scheme for a given problem and algorithms that also enjoy fast local convergence. The authors develop general perturbed Newtonian frameworks that preserve fast convergence and consider specific algorithms as particular cases within those frameworks, i.e., as perturbations of the associated basic Newton iterations. This approach yields a set of tools for the unified treatment of various algorithms, including some not of the Newton type per se. Among the new subjects addressed is the class of degenerate problems. In particular, the phenomenon of attraction of Newton iterates to critical Lagrange multipliers and its consequences as well as stabilized Newton methods for variational problems and stabilized sequential quadratic programming for optimization. This volume will b...

  7. Natural look in volume restoration.

    Science.gov (United States)

    Lupo, Mary P

    2008-09-01

    Filling and volumizing injection procedures are currently widely used for facial augmentation and re-establishing a youthful appearance. Aesthetic physicians have advanced from the practice of treating single lines and wrinkles towards filling large facial areas to globally restore natural facial contours and meet patient demand for nonsurgical rejuvenation. This review describes the different categories of fillers and volumizers based on their duration of action and ability to create a natural looking effect; they can be broadly classified as temporary or long-lasting biodegradable agents, or permanent nonbiodegradable agents. Temporary fillers are effective to correct lines and wrinkles, but may not adequately meet the need for global facial rejuvenation and volume replacement in a long-term, cost-efficient manner. Permanent fillers for global restoration pose the issue of long-term safety, and may not be compatible with changes in facial architecture with continued aging. Longer lasting volumizers provide patients with a durable, effective option for the restoration of facial volume and the re-establishment of youthful facial contours. Temporary fillers and volumizers may also be used in combination to provide a wide source of options for the global restoration and rejuvenation of the face.

  8. 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

  9. Variational integrators in plasma physics

    International Nuclear Information System (INIS)

    Kraus, Michael

    2013-01-01

    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

  10. A pilot study to assess the feasibility of measurement of adrenal gland volume by magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Grant, Lee A.; Dixon, Adrian K. (Dept. of Radiology, Cambridge Univ. Teaching Hospitals NHS Foundation Trust, Cambridge (United Kingdom)), e-mail: leegrant100@gmail.com; Napolitano, Antonella; McHugh, Simon M. (GlaxoSmithKline RandD, Clinical Unit Cambridge, Addenbrooke' s Centre for Clinical Investigation, Addenbrooke' s Hospital, Cambridge (United Kingdom)); Miller, Sam (Analysis Applications Research Group, GSK RandD, Harlow, Essex (United Kingdom)); Stephens, Kimberley (Discovery Statistics, GSK RandD, Harlow, Essex (United Kingdom))

    2010-01-15

    Background: Repeated computed tomography (CT) assessment of the adrenal glands is associated with a significant radiation burden. The increasing capabilities of magnetic resonance (MR) volumetric analysis of the adrenals make this a potentially alternative technique in man. Purpose: To determine whether MR imaging could be used to measure adrenal volume, and to determine the intra- and interobserver variation and repeatability of MR volume imaging of adrenals in healthy human subjects. Material and Methods: This was a single-cohort, sequential design, three-part study involving four MRI examinations per subject following ethical approval and informed consent. Information was collected on four healthy subjects (three male and one female). Two different investigators estimated the area of the adrenal gland for each of the 3-mm contiguous slices (and consequently adrenal volume). In order to estimate inter- and intrareader variability, a repeated-measures mixed model was fitted with adrenal volume as the dependent variable. In order to estimate any bias between readers, Bland-Altman methodology was applied. Results: Intraobserver variation for adrenal gland volume is approximately 5% of a 3-cm3 adrenal gland. Interobserver variation is approximately 9% of a 3-cm3 adrenal gland. Potential variation in measurement for adrenal volume from all sources equates to approximately 14% of a 3-cm3 adrenal gland. Verification of image reading by a second investigator (consensus reading) reduces variability. Conclusion: Analysis of adrenal gland volume using MRI is a potentially reliable technique that could be used to assess a pathological change in adrenal size

  11. Investigation of microbial adaptation to salinity variation for treatment of reverse osmosis concentrate by membrane bioreactor

    DEFF Research Database (Denmark)

    Jang, Duksoo; Moon, Chungman; Ahn, Kyuhong

    2014-01-01

    quantitative study on a microbial adaptation strategy for variations on salt concentration (0–20 g/L), lab-scale membrane bioreactors (7L working volume) with polypropylene hollow fiber membrane module (pore size 0.4 μm) were used with different adaptation strategies: instant and stepwise mode. The performance...

  12. 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 ...

  13. Speed, speed variation and crash relationships for urban arterials.

    Science.gov (United States)

    Wang, Xuesong; Zhou, Qingya; Quddus, Mohammed; Fan, Tianxiang; Fang, Shou'en

    2018-04-01

    Speed and speed variation are closely associated with traffic safety. There is, however, a dearth of research on this subject for the case of urban arterials in general, and in the context of developing nations. In downtown Shanghai, the traffic conditions in each direction are very different by time of day, and speed characteristics during peak hours are also greatly different from those during off-peak hours. Considering that traffic demand changes with time and in different directions, arterials in this study were divided into one-way segments by the direction of flow, and time of day was differentiated and controlled for. In terms of data collection, traditional fixed-based methods have been widely used in previous studies, but they fail to capture the spatio-temporal distributions of speed along a road. A new approach is introduced to estimate speed variation by integrating spatio-temporal speed fluctuation of a single vehicle with speed differences between vehicles using taxi-based high frequency GPS data. With this approach, this paper aims to comprehensively establish a relationship between mean speed, speed variation and traffic crashes for the purpose of formulating effective speed management measures, specifically using an urban dataset. From a total of 234 one-way road segments from eight arterials in Shanghai, mean speed, speed variation, geometric design features, traffic volume, and crash data were collected. Because the safety effects of mean speed and speed variation may vary at different segment lengths, arterials with similar signal spacing density were grouped together. To account for potential correlations among these segments, a hierarchical Poisson log-normal model with random effects was developed. Results show that a 1% increase in mean speed on urban arterials was associated with a 0.7% increase in total crashes, and larger speed variation was also associated with increased crash frequency. Copyright © 2018 Elsevier Ltd. All rights

  14. Variational principle for the Bloch unified reaction theory

    International Nuclear Information System (INIS)

    MacDonald, W.; Rapheal, R.

    1975-01-01

    The unified reaction theory formulated by Claude Bloch uses a boundary value operator to write the Schroedinger equation for a scattering state as an inhomogeneous equation over the interaction region. As suggested by Lane and Robson, this equation can be solved by using a matrix representation on any set which is complete over the interaction volume. Lane and Robson have proposed, however, that a variational form of the Bloch equation can be used to obtain a ''best'' value for the S-matrix when a finite subset of this basis is used. The variational principle suggested by Lane and Robson, which gives a many-channel S-matrix different from the matrix solution on a finite basis, is considered first, and it is shown that the difference results from the fact that their variational principle is not, in fact, equivalent to the Bloch equation. Then a variational principle is presented which is fully equivalent to the Bloch form of the Schroedinger equation, and it is shown that the resulting S-matrix is the same as that obtained from the matrix solution of this equation. (U.S.)

  15. Reactive solid surface morphology variation via ionic diffusion.

    Science.gov (United States)

    Sun, Zhenchao; Zhou, Qiang; Fan, Liang-Shih

    2012-08-14

    In gas-solid reactions, one of the most important factors that determine the overall reaction rate is the solid morphology, which can be characterized by a combination of smooth, convex and concave structures. Generally, the solid surface structure varies in the course of reactions, which is classically noted as being attributed to one or more of the following three mechanisms: mechanical interaction, molar volume change, and sintering. Here we show that if a gas-solid reaction involves the outward ionic diffusion of a solid-phase reactant then this outward ionic diffusion could eventually smooth the surface with an initial concave and/or convex structure. Specifically, the concave surface is filled via a larger outward diffusing surface pointing to the concave valley, whereas the height of the convex surface decreases via a lower outward diffusion flux in the vertical direction. A quantitative 2-D continuum diffusion model is established to analyze these two morphological variation processes, which shows consistent results with the experiments. This surface morphology variation by solid-phase ionic diffusion serves to provide a fourth mechanism that supplements the traditionally acknowledged solid morphology variation or, in general, porosity variation mechanisms in gas-solid reactions.

  16. [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

  17. 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 ...

  18. Do high-volume hospitals and surgeons provide better care in urologic oncology?

    Science.gov (United States)

    Eastham, James A

    2009-01-01

    Studies focusing primarily on hospital or surgical volume as a surrogate for surgical experience have found substantial variations in outcomes. Increasing surgical experience has been shown to improve outcomes after multiple procedures, including esophagectomy, pancreatectomy, and primary surgery for colon and breast cancer. More recently, evidence has been presented that surgical volume/experience affects quality of life and cancer control outcomes after urologic oncology procedures. Although most of these data pertain to radical prostatectomy, similar conclusions have been reached for radical cystectomy, retroperitoneal lymph node dissection, and management of renal cell carcinoma. This review highlights data indicating that high-volume surgeons and hospitals provide better care for radical prostatectomy.

  19. Variation of Parameters in Differential Equations (A Variation in Making Sense of Variation of Parameters)

    Science.gov (United States)

    Quinn, Terry; Rai, Sanjay

    2012-01-01

    The method of variation of parameters can be found in most undergraduate textbooks on differential equations. The method leads to solutions of the non-homogeneous equation of the form y = u[subscript 1]y[subscript 1] + u[subscript 2]y[subscript 2], a sum of function products using solutions to the homogeneous equation y[subscript 1] and…

  20. Outdoor radon variation in Romania

    International Nuclear Information System (INIS)

    Simion, Elena; Simion, Florin

    2008-01-01

    Full text: The results of a long-term survey (1992 - 2006) of the variations of outdoor radon concentrations in semi-natural location from Romania are reported in the present paper. Measurements, covering between two and four sessions of the day (morning, afternoon, evening and night), were performed on a daily bases by 37 Environmental Radioactivity Monitoring Stations from National Environmental Radioactivity Survey Network. The method used was based on indirect determination of outdoor radon from aerosol samples collected on glass micro-fibre filters by drawing the air through the filters. The sampling was performed in a fixed place at a height of 2 m above the ground surface. Total beta counting of aerosol samples collected was performed immediately and after 20 hours. Values recorded during the years of continuous measurement indicated the presence of several patterns in the long-term variation of outdoor radon concentration: diurnal, seasonal and annual variation. For diurnal variation, outdoor radon concentration shows a maximum values in the night (early hours) and minimum values by day (in the afternoon). On average, this maximum is a factor of 2 higher than the minimum. Late autumn - beginning of winter maximum and an early spring minimum are characteristic for seasonal patterns. In the long term a seasonal pattern was observed for diurnal variation, with an average diurnal maximum to minimum ratio of 1.33 in winter compared with 3.0 in the summer months. The variations of outdoor radon levels showed little correlation with the uranium concentration of the ground and were attributed to changes in soil moisture content. In dry seasons, because of the low precipitation, the soil was drying out in the summer allowing fractures to develop and radon to migrate easily through the ground. Depending on micro-climatic and geological conditions, outdoor radon average concentrations in different regions of Romania are from 1200 mBq/mc to 13065 mBq/mc. The smallest

  1. Volume dose of organs at risk in the irradiated volume

    International Nuclear Information System (INIS)

    Hishikawa, Yoshio; Tanaka, Shinichi; Miura, Takashi

    1984-01-01

    Absorbed dose of organs at risk in the 50% irradiated volume needs to be carefully monitored because there is high risk of radiation injury. This paper reports on the histogram of threedimensional volume dose of organs at risk, which is obtained by computer calculation of CT scans. In order to obtain this histogram, CT is first performed in the irradiation field. The dose in each pixel is then examined by the computer as to each slice. After the pixels of all slices in the organ at risk of the irradiated field are classified according to the doses, the number of pixels in the same dose class is counted. The result is expressed in a histogram. The histogram can show the differences of influence to organs at risk given by various radiation treatment techniques. Total volume dose of organs at risk after radiotherapy can also be obtained by integration of each dose of different treatment techniques. (author)

  2. Environmental variation partitioned into separate heritable components

    DEFF Research Database (Denmark)

    Ørsted, Michael; Rohde, Palle Duun; Hoffmann, Ary A

    2018-01-01

    Trait variation is normally separated into genetic and environmental components, yet genetic factors also control the expression of environmental variation, encompassing plasticity across environmental gradients and within-environment responses. We defined four components of environmental variation......: plasticity across environments, variability in plasticity, variation within environments, and differences in within-environment variation across environments. We assessed these components for cold tolerance across five rearing temperatures using the Drosophila melanogaster Genetic Reference Panel (DGRP...

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

    International Nuclear Information System (INIS)

    Shpotyuk, O.; Ingram, A.; Shpotyuk, M.; Filipecki, J.

    2014-01-01

    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 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

  4. 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.

  5. Volume ignition of laser driven fusion pellets and double layer effects

    International Nuclear Information System (INIS)

    Cicchitelli, L.; Eliezer, S.; Goldsworthy, M.P.; Green, F.; Hora, H.; Ray, P.S.; Stening, R.J.; Szichman, H.

    1988-01-01

    The realization of an ideal volume compression of laser-irradiated fusion pellets opens the possibility for an alternative to spark ignition proposed for many years for inertial confinement fusion. A re-evaluation of the difficulties of the central spark ignition of laser driven pellets is given. The alternative volume compression theory, together with volume burn and volume ignition, have received less attention and are re-evaluated in view of the experimental verification generalized fusion gain formulas, and the variation of optimum temperatures derived at self-ignition. Reactor-level DT fusion with MJ-laser pulses and volume compression to 50 times the solid-state density are estimated. Dynamic electric fields and double layers at the surface and in the interior of plasmas result in new phenomena for the acceleration of thermal electrons to suprathermal electrons. Double layers also cause a surface tension which stabilizes against surface wave effects and Rayleigh-Taylor instabilities. (author)

  6. Single-dose volume regulation algorithm for a gas-compensated intrathecal infusion pump.

    Science.gov (United States)

    Nam, Kyoung Won; Kim, Kwang Gi; Sung, Mun Hyun; Choi, Seong Wook; Kim, Dae Hyun; Jo, Yung Ho

    2011-01-01

    The internal pressures of medication reservoirs of gas-compensated intrathecal medication infusion pumps decrease when medication is discharged, and these discharge-induced pressure drops can decrease the volume of medication discharged. To prevent these reductions, the volumes discharged must be adjusted to maintain the required dosage levels. In this study, the authors developed an automatic control algorithm for an intrathecal infusion pump developed by the Korean National Cancer Center that regulates single-dose volumes. The proposed algorithm estimates the amount of medication remaining and adjusts control parameters automatically to maintain single-dose volumes at predetermined levels. Experimental results demonstrated that the proposed algorithm can regulate mean single-dose volumes with a variation of 98%. © 2010, Copyright the Authors. Artificial Organs © 2010, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  7. Ethnic variations in lung cancer.

    Science.gov (United States)

    Groeger, A M; Mueller, M R; Odocha, O; Dekan, G; Salat, A; Röthy, W; Esposito, V; Caputi, M; Wolner, E; Kaiser, H E

    1997-01-01

    Cancer of the lung is the most frequent cancer in the world, but with wide geographical variation in risk. It is most spread among males of all races worldwide, the only exception being its incidence among Chinese women aged 70 years and older. When comparing the different ethnic groups we have to consider that besides inhaling cigarette smoke actively or as a passive smoker the exposure to occupational carcinogens varies considerably according to different work places. In our study we compared 10 years of data from African-Americans in Howard University Hospital, Washington D.C. with 20 years of data from the white population in the University Hospital of Vienna, Austria. Ethnic patterns are generally consistent within each group in terms of both incidence and mortality. The difference in susceptibility between the sexes, the three major racial groups and already proven differences in genetic variations indicate the difference between individuals concerning the initiation and progression of lung cancer.

  8. 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.

  9. Periodic weather and climate variations

    International Nuclear Information System (INIS)

    Ivanov, Vladimir V

    2002-01-01

    Variations in meteorological parameters are largely due to periodic processes and can be forecast for several years. Many such processes are related to astronomical factors such as the gravitational influences of the Moon and the Sun, and the modulation of solar irradiance by lunar and planetary motion. The Moon, Jupiter, and Venus have the strongest effect. These influences produce lines in the spectra of meteorological variations, which are combinations of the harmonics of the frequencies of revolution of the planets, the Earth, and the Moon around the Sun with the harmonics of the lunar revolution around the Earth. Due to frequency differences between the orbital and radial motions, fine spectral features of three types appear: line splitting, line-profile complications due to radial oscillations, and additional lines due to the combination of radial-oscillation frequencies with perturbation harmonics. (reviews of topical problems)

  10. VARIATIONAL PRINCIPLE FOR PLANETARY INTERIORS

    International Nuclear Information System (INIS)

    Zeng, Li; Jacobsen, Stein B.

    2016-01-01

    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.

  11. Variational approach in transport theory

    International Nuclear Information System (INIS)

    Panta Pazos, R.; Tullio de Vilhena, M.

    2004-01-01

    In this work we present a variational approach to some methods to solve transport problems of neutral particles. We consider a convex domain X (for example the geometry of a slab, or a convex set in the plane, or a convex bounded set in the space) and we use discrete ordinates quadrature to get a system of differential equations derived from the neutron transport equation. The boundary conditions are vacuum for a subset of the boundary, and of specular reflection for the complementary subset of the boundary. Recently some different approximation methods have been presented to solve these transport problems. We introduce in this work the adjoint equations and the conjugate functions obtained by means of the variational approach. First we consider the general formulation, and then some numerical methods such as spherical harmonics and spectral collocation method. (authors)

  12. Variational approach in transport theory

    Energy Technology Data Exchange (ETDEWEB)

    Panta Pazos, R. [Nucler Engineering Department, UFRGS, Porto-Alegre (Brazil); Tullio de Vilhena, M. [Institute of Mathematics, UFRGS, Porto-Alegre (Brazil)

    2004-07-01

    In this work we present a variational approach to some methods to solve transport problems of neutral particles. We consider a convex domain X (for example the geometry of a slab, or a convex set in the plane, or a convex bounded set in the space) and we use discrete ordinates quadrature to get a system of differential equations derived from the neutron transport equation. The boundary conditions are vacuum for a subset of the boundary, and of specular reflection for the complementary subset of the boundary. Recently some different approximation methods have been presented to solve these transport problems. We introduce in this work the adjoint equations and the conjugate functions obtained by means of the variational approach. First we consider the general formulation, and then some numerical methods such as spherical harmonics and spectral collocation method. (authors)

  13. Tidal variations of earth rotation

    Science.gov (United States)

    Yoder, C. F.; Williams, J. G.; Parke, M. E.

    1981-01-01

    The periodic variations of the earths' rotation resulting from the tidal deformation of the earth by the sun and moon were rederived including terms with amplitudes of 0.002 millisec and greater. The series applies to the mantle, crust, and oceans which rotate together for characteristic tidal periods; the scaling parameter is the ratio of the fraction of the Love number producing tidal variations in the moment of inertia of the coupled mantle and oceans (k) to the dimensionless polar moment of inertia of the coupled moments (C). The lunar laser ranging data shows that k/C at monthly and fortnightly frequencies equals 0.99 + or - 0.15 and 0.99 + or - 0.20 as compared to the theoretical value of 0.94 + or - 0.04.

  14. 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...... of water in the oxidized zone of the aquifer nearly halved, following implementation of action plans to reduce N leaching from agriculture. However, due to denitrification by pyrite oxidation in the aquifer, a plume of sulfate-rich water migrates through the aquifer as a legacy of the historical NO3...... 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...

  15. Quantitative variation in natural populations

    International Nuclear Information System (INIS)

    Parsons, P.A.

    1975-01-01

    Quantitative variation is considered in natural populations using Drosophila as the example. A knowledge of such variation enables its rapid exploitation in directional selection experiments as shown for scutellar chaeta number. Where evidence has been obtained, genetic architectures are in qualitative agreement with Mather's concept of balance for traits under stabilizing selection. Additive genetic control is found for acute environmental stresses, but not for less acute stresses as shown by exposure to 60 Co-γ rays. D. simulans probably has a narrower ecological niche than its sibling species D. melanogaster associated with lower genetic heterogeneity. One specific environmental stress to which D. simulans is sensitive in nature is ethyl alcohol as shown by winery data. (U.S.)

  16. 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.

  17. Coarse Grained Exponential Variational Autoencoders

    KAUST Repository

    Sun, Ke

    2017-02-25

    Variational autoencoders (VAE) often use Gaussian or category distribution to model the inference process. This puts a limit on variational learning because this simplified assumption does not match the true posterior distribution, which is usually much more sophisticated. To break this limitation and apply arbitrary parametric distribution during inference, this paper derives a \\\\emph{semi-continuous} latent representation, which approximates a continuous density up to a prescribed precision, and is much easier to analyze than its continuous counterpart because it is fundamentally discrete. We showcase the proposition by applying polynomial exponential family distributions as the posterior, which are universal probability density function generators. Our experimental results show consistent improvements over commonly used VAE models.

  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. On Quadratic Variation of Martingales

    Indian Academy of Sciences (India)

    where D ( [ 0 , ∞ ) , R ) denotes the class of real valued r.c.l.l. functions on [ 0 , ∞ ) such that for a locally square integrable martingale ( M t ) with r.c.l.l. paths,. Ψ ( M . ( ) ) = A . ( ). gives the quadratic variation process (written usually as [ M , M ] t ) of ( M t ) . We also show that this process ( A t ) is the unique increasing ...

  20. Fractional variational principles in action

    Energy Technology Data Exchange (ETDEWEB)

    Baleanu, Dumitru [Department of Mathematics and Computer Science, Faculty of Art and Sciences, Cankaya University, 06530 Ankara (Turkey); Institute of Space Sciences, PO Box MG-23, R 76900, Magurele-Bucharest (Romania)], E-mail: dumitru@cankaya.edu.tr

    2009-10-15

    The fractional calculus has gained considerable importance in various fields of science and engineering, especially during the last few decades. An open issue in this emerging field is represented by the fractional variational principles area. Therefore, the fractional Euler-Lagrange and Hamilton equations started to be examined intensely during the last decade. In this paper, we review some new trends in this field and we discuss some of their potential applications.

  1. Variations of posterior vitreous detachment

    OpenAIRE

    Kakehashi, A.; Kado, M.; Akiba, J.; Hirokawa, H.

    1997-01-01

    AIMS—To identify variations in posterior vitreous detachment (PVD) and establish a clinical classification system for PVD.
METHODS—400 consecutive eyes were examined using biomicroscopy and vitreous photography and classified the PVD variations—complete PVD with collapse, complete PVD without collapse, partial PVD with thickened posterior vitreous cortex (TPVC), or partial PVD without TPVC.
RESULTS—In each PVD type, the most frequently seen ocular pathologies were as follows: in complete PVD ...

  2. Deep Feature Consistent Variational Autoencoder

    OpenAIRE

    Hou, Xianxu; Shen, Linlin; Sun, Ke; Qiu, Guoping

    2016-01-01

    We present a novel method for constructing Variational Autoencoder (VAE). Instead of using pixel-by-pixel loss, we enforce deep feature consistency between the input and the output of a VAE, which ensures the VAE's output to preserve the spatial correlation characteristics of the input, thus leading the output to have a more natural visual appearance and better perceptual quality. Based on recent deep learning works such as style transfer, we employ a pre-trained deep convolutional neural net...

  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. 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 (Cornelia); 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

  5. 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. © 2011 IEEE

  6. 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.

  7. 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...

  8. Partial volume effect in MRI

    International Nuclear Information System (INIS)

    Maeda, Munehiro; Yoshiya, Kazuhiko; Suzuki, Eiji

    1989-01-01

    According to the direction and the thickness of the imaging slice in tomography, the border between the tissues becomes unclear (partial volume effect). In the present MRI experiment, we examined border area between fat and water components using phantom in order to investigate the partial volume effect in MRI. In spin echo sequences, the intensity of the border area showed a linear relationship with composition of fat and water. Whereas, in inversion recovery and field echo sequences, we found the parameters to produce an extremely low intensity area at the border region between fat and water. This low intensity area was explained by cancellation of NMR signals from fat and water due to the difference in the direction of magnetic vectors. Clinically, partial volume effect can cause of mis-evaluation of walls, small nodules, tumor capsules and the tumor invasion in the use of inversion recovery and field echo sequences. (author)

  9. Cell swelling and volume regulation

    DEFF Research Database (Denmark)

    Hoffmann, Else Kay

    1992-01-01

    The extracellular space in the brain is typically 20% of the tissue volume and is reduced to at least half its size under conditions of neural insult. Whether there is a minimum size to the extracellular space was discussed. A general model for cell volume regulation was presented, followed...... by a discussion on how many of the generally involved mechanisms are identified in neural cells and (or) in astrocytes. There seems to be clear evidence suggesting that parallel K+ and Cl- channels mediate regulatory volume decrease in primary cultures of astrocytes, and a stretch-activated cation channel has...... been reported. The role of the different channels was discussed. A taurine leak pathway is clearly activated after cell swelling both in astrocytes and in neurones. The relations between the effect of glutamate and cell swelling were discussed. Discussion on the clearance of potassium from...

  10. Radiographic determination of urinary bladder volume and residual urine volume

    International Nuclear Information System (INIS)

    Klumair, J.

    1977-01-01

    In the course of a long study the author has tested most of the methods for determination of urinary bladder volume. A radiographic method which can state bladder volume exactly in cc's is attainable only with great time and effort. In the author's experience, however, it is possible, by means of a pattern in connection with a IVP, to estimate residual urine volume from a post-void picture of the bladder with sufficient accuracy for practical purposes. An account is given of the production of this pattern and of two relatively simple calculations for residual volume based on AP and lateral views of circular- and ellipsoid-shaped bladders. Also discussed is the radiation exposure which varies with the radiographic methods used. In male patients, the radiation exposure appears to be negligible, especially when the testicles are protected by a radiation shield. In female patients - which make up only a small fraction of all patients -, radiation exposure is higher but must be accepted. (orig./MG) [de

  11. 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...

  12. 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....

  13. Planimetric determination of lung volume

    International Nuclear Information System (INIS)

    Bieber, M.; Maurer, H.J.

    1984-01-01

    The total volume of the lungs was determined by digital planimetry in 102 patients with emphysema and 33 normal controls aged between 30 and 79 years. The results were compared with the findings obtained from spirometric measurements. Mean values showed a significant relationship to age, body size and body surface. Planimetrically determined lung volume did not show a linear relationship with age, but increased after 60 years. Beyong 60 years, spirometric findings were lower because of an increase in the number of patients with emphysema. The results have shown that digital planimetry is a useful addition to spirometry. (orig.) [de

  14. Large volume cryogenic silicon detectors

    International Nuclear Information System (INIS)

    Braggio, C.; Boscardin, M.; Bressi, G.; Carugno, G.; Corti, D.; Galeazzi, G.; Zorzi, N.

    2009-01-01

    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 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.

  15. 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.

  16. 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

  17. Atlas of total body radionuclide imaging. Volume I and II

    International Nuclear Information System (INIS)

    Fordham, E.W.; Ali, A.; Turner, D.A.; Charters, J.

    1982-01-01

    This two-volume work on total body imaging may well be regarded by future historians of nuclear medicine as representing the high points in the art of total body imaging in clinical nuclear medicine. With regard to information content and volume, it is the largest collection of well-interpreted, beautifully reproduced, total body images available to date. The primary goal of this atlas is to demonstrate patterns of abnormality in both typical and less typical variations. This goal is accomplished with many well-described examples of technical artifacts, of normal variants, of common and of rare diseases, and of pitfalls in interpretations. Volume I is entirely dedicated to skeletal imaging with Tc-99m labeled phosphates or phosphonates. The volume is divided into 22 chapters, which include chapters on methodology and instrumentation, chapters on the important bone diseases and other topics such as a treatise on false-negative and false-positive scans, and soft tissue and urinary tract abnormalities recognizable on bone scintigrams

  18. Marijuana smoking: effects of varying puff volume and breathhold duration.

    Science.gov (United States)

    Azorlosa, J L; Greenwald, M K; Stitzer, M L

    1995-02-01

    Two studies were conducted to quantify biological and behavioral effects resulting from exposure to controlled doses of marijuana smoke. In one study, puff volume (30, 60 and 90 ml) and in a second study, breathhold duration (0, 10 and 20 sec) were systematically varied while holding constant other smoking topography parameters (number of puffs = 10, interpuff interval = 60 sec and inhalation volume = 25% of vital capacity). Each study also varied levels of delta 9-tetrahydro-cannabinol marijuana cigarette content (1.75% and 3.55%). Regular marijuana users served as subjects (n = 7 in each experiment). Subjects smoked 10 puffs in each of six sessions; a seventh, nonsmoking session (all measures recorded at the same times as in active smoking sessions) served as a control. Variations in puff volume produced significant dose-related changes in postsmoking plasma delta 9-tetrahydro-cannabinol levels, carbon monoxide boost and subjective effects (e.g., "high"). In contrast, breathholding for 10 or 20 sec versus 0 sec increased plasma delta 9-tetrahydro-cannabinol levels but not CO boost or subjective effects. Task performance measures were not reliably influenced by marijuana smoke exposure within the dosing ranges examined. These findings confirm the utility of the controlled smoking technology, support the notion that cumulative puff volume systematically influences biological exposure and subjective effects, but cast doubt on the common belief that prolonged breathholding of marijuana smoke enhances classical subjective effects associated with its reinforcing value in humans.

  19. Changes in atheroma volume estimated from digitized femoral arteriograms

    International Nuclear Information System (INIS)

    Nilsson, S.; Erikson, U.

    1990-01-01

    To evaluate the effects of treatment in patients with cardiovascular risk factors, valid and reproducible methods for assessing changes in atheroma volume are required. We postulated that these changes could be accurately estimated by repeat measurement of the lumen volume of the artery to be studied. With a computer-based technique, the lumen volume of a 20 cm segment of the femoral artery was measured in arteriograms from 107 patients with hypercholesterolemia. Films were digitized with use of a high-resolution scanner, cross-sectional areas were calculated with a slice thickness of 150 μm and the lumen volume was obtained by their integration. The validity of the method was demonstrated in model experiments. An automatic algorithm to correct for changes due to patient positioning was developed and validated in a model experiment. With repeat measurment 10 min and 11 to 13 months apart the coefficients of variation were 2.9% (N=107) and 6.1% (N=29), respectively. (orig.)

  20. 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.

  1. Geometrical considerations in dose volume analysis in intracavitary treatment

    International Nuclear Information System (INIS)

    Deshpande, D.D.; Shrivastava, S.K.; Pradhan, A.S.; Viswanathan, P.S.; Dinshaw, K.A.

    1996-01-01

    The present work was aimed at to study the relationship between the volume enclosed by reference iodose surface and various geometrical parameters of the intracavitary applicator in treatment of carcinoma of cervix. Pearshape volume of the reference isodose derived from the Total Reference Air Kerma (TRAK) and the product of its dimensions, height H, width W and thickness T which is dependent on the applicator geometry, were estimated for 100 intracavitary applications treated by Selectron LDR machine. Orthogonal radiographs taken for each patient were used for measurement of actual geometric dimensions of the applicator and carrying out the dosimetry on TP-11 treatment planning system. The dimensions H, W and T of reference isodose surface (60 Gy) were also noted. Ratio of the product HWT and the pearshape volume was found mainly to be a function of colpostat separation and not of other geometrical parameters like maximum vertical and anterio-posterior dimension of the applicator. The ratio remained almost constant for a particular combination of uterine tandem and colpostat. Variation in the ratios were attributed to the non-standard geometry. The ratio of the volume of reference isodose surface to the product of its dimensions in the applicator depends upon the colpostat separation. (orig./MG) [de

  2. 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.

  3. Evaluation of the Free Volume Theory to Predict Moisture Transport and Quality Changes During Broccoli Drying

    NARCIS (Netherlands)

    Jin, X.; Sman, van der R.G.M.; Boxtel, van A.J.B.

    2011-01-01

    Moisture diffusion in porous broccoli florets and stalks is modeled using the free volume and Maxwell-Eucken theories. These theories are based on the mobility of water and concern the variation of the effective diffusion coefficient for a wide range of temperature and moisture content during

  4. Evaluation of the free volume theory to predict moisture transport and quality changes during broccoli drying

    NARCIS (Netherlands)

    Jin, X.; Sman, van der R.G.M.; Boxtel, van A.J.B.

    2010-01-01

    Abstract: Moisture diffusion in porous broccoli florets and stalks is modeled by using the free volume and Maxwell-Eucken theories. These theories are based on the mobility of water and show the variation of the effective diffusion coefficient for a wide range of temperatures and moisture content of

  5. 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...

  6. 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 (Rien)

    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

  7. Definition of gross tumor volume in lung cancer: inter-observer variability

    NARCIS (Netherlands)

    van de Steene, Jan; Linthout, Nadine; de Mey, Johan; Vinh-Hung, Vincent; Claassens, Cornelia; Noppen, Marc; Bel, Arjan; Storme, Guy

    2002-01-01

    BACKGROUND AND PURPOSE: To determine the inter-observer variation in gross tumor volume (GTV) definition in lung cancer, and its clinical relevance. MATERIALS AND METHODS: Five clinicians involved in lung cancer were asked to define GTV on the planning CT scan of eight patients. Resulting GTVs were

  8. Intake plenum volume and its influence on the engine performance, cyclic variability and emissions

    International Nuclear Information System (INIS)

    Ceviz, M.A.

    2007-01-01

    Intake manifold connects the intake system to the intake valve of the engine and through which air or air-fuel mixture is drawn into the cylinder. Details of the flow in intake manifolds are extremely complex. Recently, most of engine companies are focused on variable intake manifold technology due to their improvement on engine performance. This paper investigates the effects of intake plenum volume variation on engine performance and emissions to constitute a base study for variable intake plenum. Brake and indicated engine performance characteristics, coefficient of variation in indicated mean effective pressure (COV imep ) as an indicator for cyclic variability, pulsating flow pressure in the intake manifold runner, and CO, CO 2 and HC emissions were taken into consideration to evaluate the effects of different plenum volumes. The results of this study showed that the variation in the plenum volume causes an improvement on the engine performance and the pollutant emissions. The brake torque and related performance characteristics improved pronouncedly about between 1700 and 2600 rpm by increasing plenum volume. Additionally, although the increase in the plenum volume caused the mixture leaner due to the increase in the intake runner pressure and lean mixtures inclined to increase the cyclic variability, a decrease was interestingly observed in the COV imep

  9. Predictive equations for lung volumes from computed tomography for size matching in pulmonary transplantation.

    Science.gov (United States)

    Konheim, Jeremy A; Kon, Zachary N; Pasrija, Chetan; Luo, Qingyang; Sanchez, Pablo G; Garcia, Jose P; Griffith, Bartley P; Jeudy, Jean

    2016-04-01

    Size matching for lung transplantation is widely accomplished using height comparisons between donors and recipients. This gross approximation allows for wide variation in lung size and, potentially, size mismatch. Three-dimensional computed tomography (3D-CT) volumetry comparisons could offer more accurate size matching. Although recipient CT scans are universally available, donor CT scans are rarely performed. Therefore, predicted donor lung volumes could be used for comparison to measured recipient lung volumes, but no such predictive equations exist. We aimed to use 3D-CT volumetry measurements from a normal patient population to generate equations for predicted total lung volume (pTLV), predicted right lung volume (pRLV), and predicted left lung volume (pLLV), for size-matching purposes. Chest CT scans of 400 normal patients were retrospectively evaluated. 3D-CT volumetry was performed to measure total lung volume, right lung volume, and left lung volume of each patient, and predictive equations were generated. The fitted model was tested in a separate group of 100 patients. The model was externally validated by comparison of total lung volume with total lung capacity from pulmonary function tests in a subset of those patients. Age, gender, height, and race were independent predictors of lung volume. In the test group, there were strong linear correlations between predicted and actual lung volumes measured by 3D-CT volumetry for pTLV (r = 0.72), pRLV (r = 0.72), and pLLV (r = 0.69). A strong linear correlation was also observed when comparing pTLV and total lung capacity (r = 0.82). We successfully created a predictive model for pTLV, pRLV, and pLLV. These may serve as reference standards and predict donor lung volume for size matching in lung transplantation. Copyright © 2016 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

  10. SU-F-T-378: Evaluation of Dose-Volume Variability and Parameters Between Prostate IMRT and VMAT Plans

    Energy Technology Data Exchange (ETDEWEB)

    Chow, J [Princess Margaret Cancer Centre, Toronto, ON (Canada); Jiang, R [Grand River Regional Cancer Centre, Kitchener, ON (Canada); Kiciak, A [University of Waterloo, Waterloo, ON (Canada)

    2016-06-15

    Purpose: This study compared the rectal dose-volume consistency, equivalent uniform dose (EUD) and normal tissue complication probability (NTCP) in prostate intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT). Methods: For forty prostate IMRT and fifty VMAT patients treated using the same dose prescription (78 Gy/39 fraction) and dose-volume criteria in inverse planning optimization, the rectal EUD and NTCP were calculated for each patient. The rectal dose-volume consistency, showing the variability of dose-volume histogram (DVH) among patients, was defined and calculated based on the deviation between the mean and corresponding rectal DVH. Results: From both the prostate IMRT and VMAT plans, the rectal EUD and NTCP were found decreasing with the rectal volume. The decrease rates for the IMRT plans (EUD = 0.47 × 10{sup −3} Gy cm{sup −3} and NTCP = 3.94 × 10{sup −2} % cm{sup −3}) were higher than those for the VMAT (EUD = 0.28 × 10{sup −3} Gy cm{sup −3} and NTCP = 2.61 × 10{sup −2} % cm{sup −3}). In addition, the dependences of the rectal EUD and NTCP on the dose-volume consistency were found very similar between the prostate IMRT and VMAT plans. This shows that both delivery techniques have similar variations of the rectal EUD and NTCP on the dose-volume consistency. Conclusion: Dependences of the dose-volume consistency on the rectal EUD and NTCP were compared between the prostate IMRT and VMAT plans. It is concluded that both rectal EUD and NTCP decreased with an increase of the rectal volume. The variation rates of the rectal EUD and NTCP on the rectal volume were higher for the IMRT plans than VMAT. However, variations of the rectal dose-volume consistency on the rectal EUD and NTCP were found not significant for both delivery techniques.

  11. Fast in vivo volume dose reconstruction via reference dose perturbation

    International Nuclear Information System (INIS)

    Lu, Weiguo; Chen, Mingli; Mo, Xiaohu; Parnell, Donald; Olivera, Gustavo; Galmarini, Daniel

    2014-01-01

    Purpose: Accurate on-line reconstruction of in-vivo volume dose that accounts for both machine and patient discrepancy is not clinically available. We present a simple reference-dose-perturbation algorithm that reconstructs in-vivo volume dose fast and accurately. Methods: We modelled the volume dose as a function of the fluence map and density image. Machine (output variation, jaw/leaf position errors, etc.) and patient (setup error, weight loss, etc.) discrepancies between the plan and delivery were modelled as perturbation of the fluence map and density image, respectively. Delivered dose is modelled as perturbation of the reference dose due to change of the fluence map and density image. We used both simulated and clinical data to validate the algorithm. The planned dose was used as the reference. The reconstruction was perturbed from the reference and accounted for output-variations and the registered daily image. The reconstruction was compared with the ground truth via isodose lines and the Gamma Index. Results: For various plans and geometries, the volume doses were reconstructed in few seconds. The reconstruction generally matched well with the ground truth. For the 3%/3mm criteria, the Gamma pass rates were 98% for simulations and 95% for clinical data. The differences mainly appeared on the surface of the phantom/patient. Conclusions: A novel reference-dose-perturbation dose reconstruction model is presented. The model accounts for machine and patient discrepancy from planning. The algorithm is simple, fast, yet accurate, which makes online in-vivo 3D dose reconstruction clinically feasible.

  12. Chlorophyll-a specific volume scattering function of phytoplankton.

    Science.gov (United States)

    Tan, Hiroyuki; Oishi, Tomohiko; Tanaka, Akihiko; Doerffer, Roland; Tan, Yasuhiro

    2017-06-12

    Chlorophyll-a specific light volume scattering functions (VSFs) by cultured phytoplankton in visible spectrum range is presented. Chlorophyll-a specific VSFs were determined based on the linear least squares method using a measured VSFs with different chlorophyll-a concentrations. We found obvious variability of it in terms of spectral and angular shapes of VSF between cultures. It was also presented that chlorophyll-a specific scattering significantly affected on spectral variation of the remote sensing reflectance, depending on spectral shape of b. This result is useful for developing an advance algorithm of ocean color remote sensing and for deep understanding of light in the sea.

  13. Diurnal variations of Titan's ionosphere

    Science.gov (United States)

    Cui, J.; Galand, M.; Yelle, R. V.; Vuitton, V.; Wahlund, J.-E.; Lavvas, P. P.; Müller-Wodarg, I. C. F.; Cravens, T. E.; Kasprzak, W. T.; Waite, J. H.

    2009-06-01

    We present our analysis of the diurnal variations of Titan's ionosphere (between 1000 and 1300 km) based on a sample of Ion Neutral Mass Spectrometer (INMS) measurements in the Open Source Ion (OSI) mode obtained from eight close encounters of the Cassini spacecraft with Titan. Although there is an overall ion depletion well beyond the terminator, the ion content on Titan's nightside is still appreciable, with a density plateau of ˜700 cm-3 below ˜1300 km. Such a plateau is a combined result of significant depletion of light ions and modest depletion of heavy ones on Titan's nightside. We propose that the distinctions between the diurnal variations of light and heavy ions are associated with their different chemical loss pathways, with the former primarily through “fast” ion-neutral chemistry and the latter through “slow” electron dissociative recombination. The strong correlation between the observed night-to-day ion density ratios and the associated ion lifetimes suggests a scenario in which the ions created on Titan's dayside may survive well to the nightside. The observed asymmetry between the dawn and dusk ion density profiles also supports such an interpretation. We construct a time-dependent ion chemistry model to investigate the effect of ion survival associated with solid body rotation alone as well as superrotating horizontal winds. For long-lived ions, the predicted diurnal variations have similar general characteristics to those observed. However, for short-lived ions, the model densities on the nightside are significantly lower than the observed values. This implies that electron precipitation from Saturn's magnetosphere may be an additional and important contributor to the densities of the short-lived ions observed on Titan's nightside.

  14. 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...

  15. 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...... microstructure noise in a general framework where little is assumed about the noise. For the practical implementation, we adopt the dis- crete Markov chain model that is well suited for the analysis of financial high-frequency prices. The Markov chain framework facilitates simple expressions and elegant analyti...

  16. Variational collocation on finite intervals

    International Nuclear Information System (INIS)

    Amore, Paolo; Cervantes, Mayra; Fernandez, Francisco M

    2007-01-01

    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

  17. Neodymium isotopic variations in seawater

    Science.gov (United States)

    Piepgras, D. J.; Wasserburg, G. J.

    1980-01-01

    Direct measurement of the isotopic composition of Nd in the Atlantic agree with the Nd content in ferromanganese sediments and differ from the observed amounts in the Pacific samples. These data indicate the existence of distinctive differences in the isotopic composition of Nd in the waters of major oceans; the average values determined from seawater and ferromanganese sediments are considerably lower than in sources with oceanic mantle affinities showing that the REE in the oceans is dominated by continental sources. The Nd isotopic variations in seawater are applied to relate the residence time of Nd and mixing rates between the oceans.

  18. Solar cycles and climate variations

    International Nuclear Information System (INIS)

    Chistyakov, V.F.

    1990-01-01

    Climate oscillations with 100-, 200- and 300-year periods are positively correlated with solar activity oscillations: the higher is solar activity the warmer is climate. According to geological data (varved clays) it is determined, that length of cycles has decreased from 23.4 up to 11 years during latter 2.5 billion years. 12-year cycles occurred during the great glaciation periods, while 10-year cycles occurred during interglaciation periods. It is suggested, that these oscillations are related with variations of the solar activity and luminescence

  19. NJP VOLUME 41 NO 2

    African Journals Online (AJOL)

    PROF. EZECHUKWU

    2013-11-24

    Nov 24, 2013 ... nation and volume of urine voided; from1- 2 times to 10. -15 times during the day ... Serum electrolytes, urea and creatinine done on admis- sion showed ... cient synthesis and or release of AVP.7The clinical manifestation of ...

  20. 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....

  1. Spectrum '86: Proceedings: Volume 2

    International Nuclear Information System (INIS)

    Pope, J.M.; Leonard, I.M.; Mayer, E.J.

    1987-07-01

    This document, Volume 2, contains 96 papers on various aspects of radioactive waste management. Session topics include decontamination and decommissioning/endash/industry experience, characterization and safety, techniques, facility and plant decontamination; TRU waste management; regulatory aspects; economics; environmental issues and impacts; construction, operation, and maintenance. Individual papers were processed separately for the data bases

  2. NJP VOLUME 39 No 4

    African Journals Online (AJOL)

    Prof Ezechukwu

    2012-02-28

    Feb 28, 2012 ... Disorders affecting fluid volume and electrolyte compo- sition are common ... knowledge of the mechanism of action of diuretic drugs and appropriate ... Presence of non-permeable solute will oppose H2O ex- traction. NaCl is actively .... loop not affected. • In oral administration rate and extent of absorption.

  3. Volume tables for red alder.

    Science.gov (United States)

    Floyd A. Johnson; R. M. Kallander; Paul G. Lauterbach

    1949-01-01

    The increasing importance of red alder as a commercial species in the Pacific Northwest has prompted the three agencies listed above to pool their tree measurement data for the construction of standard regional red alder volume tables. The tables included here were based on trees from a variety of sites and form classes. Approximately one quarter of the total number of...

  4. PATRAM '80. Proceedings. Volume 2

    International Nuclear Information System (INIS)

    Huebner, H.W.

    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)

  5. Volume 7 No. 2 2007

    African Journals Online (AJOL)

    ROP4

    communities in Butere, and three of the eight communities, in Khwisero. The ... 3. Volume 7 No. 2 2007. INTRODUCTION. Micronutrient malnutrition is recognized as a serious threat to the health and productivity of people. Deficiencies in three major ... They also have uncontested advantage of allowing for the natural.

  6. 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.

  7. 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...

  8. PATRAM '80. Proceedings. Volume 1

    International Nuclear Information System (INIS)

    Huebner, H.W.

    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)

  9. Volume 7 No. 2 2007

    African Journals Online (AJOL)

    ROP4

    (having been in operation for at least five years). ... rights of the child, the children were weighed in light clothing rather than in the nude. ..... 13. Volume 7 No. 2 2007. Table 1: Mean Z-scores by Area, Type of Farming, Income Level, Sex of ...

  10. Healing Magazine, Volume 8, 2003.

    Science.gov (United States)

    2003

    This volume of "Healing Magazine" features practical, clinical information aimed at sharing current work in children's mental health. The first issue contains articles on intervention for self-injurious behavior, providing school-based grief groups, effectively using time-out as a parenting tool, and KidsPeace's suicide prevention…

  11. History of CERN. Volume 3

    International Nuclear Information System (INIS)

    Krige, J.

    1996-01-01

    The present volume continues the story of the history of the European Organization for Nuclear Research (CERN) in Geneva, Switzerland, concentrating on the years between the mid 1960s and the late 1970s. Whereas the first two volumes were the product of a team of historians, this book is rather a collection of studies by authors with very different professional backgrounds and institutional locations. It also differs from the predecessor volumes in the fact that it consists of distinct case studies dealing with a number of issues deemed important. The first part of this volume, containing contributions by historians of science, perceives the laboratory as being at the node of a complex of interconnected relationships between scientists and science managers on the staff, the users in the member states, and the governments which were called upon to finance the laboratory. In part 2 the physical results, obtained at CERN, are surveyed, while in part 3 two chapters are presented, one on engineering and technology, and the other on the research and development of electronic position detectors

  12. Eddy current manual, volume 2

    International Nuclear Information System (INIS)

    Cecco, V.S.; Van Drunen, G.; Sharp, F.L.

    1984-09-01

    This report on eddy current testing is divided into three sections: (a) Demonstration of Basic Principles, (b) Practical (Laboratory) Tests and, (c) Typical Certification Questions. It is intended to be used as a supplement to ΣEddy Current Manual, Volume 1Σ (AECL-7523) during CSNDT Foundation Level II and III courses

  13. Interfractional Dose Variations in Intensity-Modulated Radiotherapy With Breath-Hold for Pancreatic Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Mitsuhiro [Department of Radiation Oncology and Image-Applied Therapy, Kyoto University Graduate School of Medicine, Kyoto (Japan); Shibuya, Keiko, E-mail: kei@kuhp.kyoto-u.ac.jp [Department of Radiation Oncology and Image-Applied Therapy, Kyoto University Graduate School of Medicine, Kyoto (Japan); Nakamura, Akira [Department of Radiation Oncology and Image-Applied Therapy, Kyoto University Graduate School of Medicine, Kyoto (Japan); Shiinoki, Takehiro [Department of Nuclear Engineering, Kyoto University Graduate School of Engineering, Kyoto (Japan); Matsuo, Yukinori [Department of Radiation Oncology and Image-Applied Therapy, Kyoto University Graduate School of Medicine, Kyoto (Japan); Nakata, Manabu [Clinical Radiology Service Division, Kyoto University Hospital, Kyoto (Japan); Sawada, Akira; Mizowaki, Takashi; Hiraoka, Masahiro [Department of Radiation Oncology and Image-Applied Therapy, Kyoto University Graduate School of Medicine, Kyoto (Japan)

    2012-04-01

    Purpose: To investigate the interfractional dose variations for intensity-modulated radiotherapy (RT) combined with breath-hold (BH) at end-exhalation (EE) for pancreatic cancer. Methods and Materials: A total of 10 consecutive patients with pancreatic cancer were enrolled. Each patient was fixed in the supine position on an individualized vacuum pillow with both arms raised. Computed tomography (CT) scans were performed before RT, and three additional scans were performed during the course of chemoradiotherapy using a conventional RT technique. The CT data were acquired under EE-BH conditions (BH-CT) using a visual feedback technique. The intensity-modulated RT plan, which used five 15-MV coplanar ports, was designed on the initial BH-CT set with a prescription dose of 39 Gy at 2.6 Gy/fraction. After rigid image registration between the initial and subsequent BH-CT scans, the dose distributions were recalculated on the subsequent BH-CT images under the same conditions as in planning. Changes in the dose-volume metrics of the gross tumor volume (GTV), clinical target volume (CTV = GTV + 5 mm), stomach, and duodenum were evaluated. Results: For the GTV and clinical target volume (CTV), the 95th percentile of the interfractional variations in the maximal dose, mean dose, dose covering 95% volume of the region of structure, and percentage of the volume covered by the 90% isodose line were within {+-}3%. Although the volume covered by the 39 Gy isodose line for the stomach and duodenum did not exceed 0.1 mL at planning, the volume covered by the 39 Gy isodose line for these structures was up to 11.4 cm{sup 3} and 1.8 cm{sup 3}, respectively. Conclusions: Despite variations in the gastrointestinal state and abdominal wall position at EE, the GTV and CTV were mostly ensured at the planned dose, with the exception of 1 patient. Compared with the duodenum, large variations in the stomach volume receiving high-dose radiation were observed, which might be beyond the

  14. Respiratory variation in peak aortic velocity accurately predicts fluid responsiveness in children undergoing neurosurgery under general anesthesia.

    Science.gov (United States)

    Morparia, Kavita G; Reddy, Srijaya K; Olivieri, Laura J; Spaeder, Michael C; Schuette, Jennifer J

    2018-04-01

    The determination of fluid responsiveness in the critically ill child is of vital importance, more so as fluid overload becomes increasingly associated with worse outcomes. Dynamic markers of volume responsiveness have shown some promise in the pediatric population, but more research is needed before they can be adopted for widespread use. Our aim was to investigate effectiveness of respiratory variation in peak aortic velocity and pulse pressure variation to predict fluid responsiveness, and determine their optimal cutoff values. We performed a prospective, observational study at a single tertiary care pediatric center. Twenty-one children with normal cardiorespiratory status undergoing general anesthesia for neurosurgery were enrolled. Respiratory variation in peak aortic velocity (ΔVpeak ao) was measured both before and after volume expansion using a bedside ultrasound device. Pulse pressure variation (PPV) value was obtained from the bedside monitor. All patients received a 10 ml/kg fluid bolus as volume expansion, and were qualified as responders if stroke volume increased >15% as a result. Utility of ΔVpeak ao and PPV and to predict responsiveness to volume expansion was investigated. A baseline ΔVpeak ao value of greater than or equal to 12.3% best predicted a positive response to volume expansion, with a sensitivity of 77%, specificity of 89% and area under receiver operating characteristic curve of 0.90. PPV failed to demonstrate utility in this patient population. Respiratory variation in peak aortic velocity is a promising marker for optimization of perioperative fluid therapy in the pediatric population and can be accurately measured using bedside ultrasonography. More research is needed to evaluate the lack of effectiveness of pulse pressure variation for this purpose.

  15. Vascular Variations Associated with Intracranial Aneurysms.

    Science.gov (United States)

    Orakdogen, Metin; Emon, Selin Tural; Somay, Hakan; Engin, Taner; Is, Merih; Hakan, Tayfun

    2017-01-01

    To investigate the vascular variations in patients with intracranial aneurysm in circle of Willis. We used the data on 128 consecutive intracranial aneurysm cases. Cerebral angiography images were analyzed retrospectively. Arteries were grouped as anterior cerebral arterial system (ACS), posterior cerebral arterial system (PCS) and middle cerebral arterial system (MCS) for grouping vascular variations. Lateralization, being single/multiple, gender; and also any connection with accompanying aneurysms" number, localization, dimension, whether bleeding/incidental aneurysm has been inspected. Variations were demonstrated in 57.8% of the cases. The most common variation was A1 variation (34.4%). The rate of variations was 36.7%, 24.2% and 10.2% respectively in ACS, PCS and MCS. MCS variations were significantly higher in males. Anterior communicating artery (ACoA) aneurysm observance rates were significantly higher and posterior communicating artery (PCoA) aneurysm and middle cerebral artery (MCA) aneurysm observance rates were significantly lower when compared to "no ACS variation detected" cases. In "PCS variation detected" cases, PCoA aneurysm observance rates and coexistence of multiple variations were significantly higher. The rate of vascular variations in patients with aneurysms was 57.8%. Arterial hypoplasia and aplasia were the most common variations. ACS was the most common region that variations were located in; they were mostly detected on the right side. Coexistence of ACoA aneurysm was higher than PCoA and MCA aneurysms. In the PCS variations group, PCoA aneurysms were the most common aneurysms that accompanying the variation and multiple variations were more common than in the other two groups. The variations in MCS were most common in males.

  16. Intralesional and metastatic heterogeneity in malignant melanomas demonstrated by stereologic estimates of nuclear volume

    DEFF Research Database (Denmark)

    Sørensen, Flemming Brandt; Erlandsen, M

    1990-01-01

    Regional variability of nuclear 3-dimensional size can be estimated objectively using point-sampled intercepts obtained from different, defined zones within individual neoplasms. In the present study, stereologic estimates of the volume-weighted mean nuclear volume, nuclear vv, within peripheral...... on average larger in the peripheral zones of primary melanomas, than nuclear vv in central zones (2p = 6.7 x 10(-4), whereas no zonal differences were demonstrated in metastatic lesions (2p = 0.21). A marked intraindividual variation was demonstrated between primary and corresponding secondary melanomas (2p...... melanomas showed large interindividual variation. This finding emphasizes that unbiased estimates of nuclear vv are robust to regional heterogeneity of nuclear volume and thus suitable for purposes of objective, quantitative malignancy grading of melanomas....

  17. 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)

  18. Variational inference & deep learning : A new synthesis

    NARCIS (Netherlands)

    Kingma, D.P.

    2017-01-01

    In this thesis, Variational Inference and Deep Learning: A New Synthesis, we propose novel solutions to the problems of variational (Bayesian) inference, generative modeling, representation learning, semi-supervised learning, and stochastic optimization.

  19. Variational inference & deep learning: A new synthesis

    OpenAIRE

    Kingma, D.P.

    2017-01-01

    In this thesis, Variational Inference and Deep Learning: A New Synthesis, we propose novel solutions to the problems of variational (Bayesian) inference, generative modeling, representation learning, semi-supervised learning, and stochastic optimization.

  20. Amazing variational approach to chemical reactions

    OpenAIRE

    Fernández, Francisco M.

    2009-01-01

    In this letter we analyse an amazing variational approach to chemical reactions. Our results clearly show that the variational expressions are unsuitable for the analysis of empirical data obtained from chemical reactions.

  1. Nonlinear variational inequalities of semilinear parabolic type

    Directory of Open Access Journals (Sweden)

    Park Jong-Yeoul

    2001-01-01

    Full Text Available The existence of solutions for the nonlinear functional differential equation governed by the variational inequality is studied. The regularity and a variation of solutions of the equation are also given.

  2. On polar daily geomagnetic variation

    Directory of Open Access Journals (Sweden)

    Paola De Michelis

    2015-11-01

    Full Text Available The aim of this work is to investigate the nature of the daily magnetic field perturbations produced by ionospheric and magnetospheric currents at high latitudes. We analyse the hourly means of the X and Y geomagnetic field components recorded by a meridian chain of permanent geomagnetic observatories in the polar region of the Northern Hemisphere during a period of four years (1995-1998 around the solar minimum. We apply a mathematical method, known as natural orthogonal component (NOC, which is capable of characterizing the dominant modes of the geomagnetic field daily variability through a set of empirical orthogonal functions (EOFs. Using the first two modes we reconstruct a two-dimensional equivalent current representation of the ionospheric electric currents, which contribute substantially to the geomagnetic daily variations. The obtained current structures resemble the equivalent current patterns of DP2 and DP1. We characterize these currents by studying their evolution with the geomagnetic activity level and by analysing their dependence on the interplanetary magnetic field. The obtained results support the idea of a coexistence of two main processes during all analysed period although one of them, the directly driven process, represents the dominant component of the geomagnetic daily variation.

  3. Dosimetric impact of prostate volume change between CT-based HDR brachytherapy fractions

    International Nuclear Information System (INIS)

    Kim, Yongbok; Hsu, I-C.; Lessard, Etienne; Vujic, Jasmina; Pouliot, Jean

    2004-01-01

    Purpose: The objective is to evaluate the prostate volume change and its dosimetric consequences after the insertion of catheters for high-dose-rate brachytherapy. Methods and Materials: For 13 consecutive patients, a spiral CT scan was acquired before each of the 2 fractions, separated on average by 20 hours. The coordinates of the catheters were obtained on 3 axial CT slices corresponding to apex, mid portion, and base portion of the prostate. A mathematical expansion model was used to evaluate the change of prostate volumes between the 2 fractions. It is based on the difference in the cube of the average distance between the centroid and catheter positions. The variation of implant dose-volume histograms between fractions was computed for plans produced by either inverse planning based on simulated annealing or geometric optimization. Results: The average magnitude of either increase or reduction in prostate volume was 7.8% (range, 2-17%). This volume change corresponds to an average prostate radius change of only 2.5% (range, 0.7-5.4%). For 5 patients, the prostate volume increased on average by 9% (range, 2-17%), whereas a reduction was observed for 8 patients by an average of 7% (range, 2-13%). More variation was observed at the prostate base than at mid or apex gland. The comparison of implant dose-volume histograms showed a small reduction of V100 receiving the prescription dose, with an average of 3.5% (range, 0.5-12%) and 2.2% (range, 1-6%) for inverse planning based on our simulated annealing and geometric optimization plans, respectively. Conclusion: Small volume change was observed between treatment fractions. This translates into small changes in dose delivered to the prostate volume

  4. Variation of Shrinkage Strain within the Depth of Concrete Beams

    Directory of Open Access Journals (Sweden)

    Jong-Hyun Jeong

    2015-11-01

    Full Text Available The variation of shrinkage strain within beam depth was examined through four series of time-dependent laboratory experiments on unreinforced concrete beam specimens. Two types of beam specimens, horizontally cast and vertically cast, were tested; shrinkage variation was observed in the horizontally cast specimens. This indicated that the shrinkage variation within the beam depth was due to water bleeding and tamping during the placement of the fresh concrete. Shrinkage strains were measured within the beam depth by two types of strain gages, surface-attached and embedded. The shrinkage strain distribution within the beam depth showed a consistent tendency for the two types of gages. The test beams were cut into four sections after completion of the test, and the cutting planes were divided into four equal sub-areas to measure the aggregate concentration for each sub-area of the cutting plane. The aggregate concentration increased towards the bottom of the beam. The shrinkage strain distribution was estimated by Hobbs’ equation, which accounts for the change of aggregate volume concentration.

  5. Homogenization of variational inequalities for obstacle problems

    International Nuclear Information System (INIS)

    Sandrakov, G V

    2005-01-01

    Results on the convergence of solutions of variational inequalities for obstacle problems are proved. The variational inequalities are defined by a non-linear monotone operator of the second order with periodic rapidly oscillating coefficients and a sequence of functions characterizing the obstacles. Two-scale and macroscale (homogenized) limiting variational inequalities are obtained. Derivation methods for such inequalities are presented. Connections between the limiting variational inequalities and two-scale and macroscale minimization problems are established in the case of potential operators.

  6. Interobserver Delineation variation using CT versus combined CT + MRI in intensity- modulated radiotherapy for prostate cancer

    International Nuclear Information System (INIS)

    Villeirs, G.M.; Verstraete, K.L.; Vaerenbergh, K. van; Vakaet, L.; Bral, S.; Claus, F.; Neve, W.J. de; Meerleer, G.O. de

    2005-01-01

    Purpose: to quantify interobserver variation of prostate and seminal vesicle delineations using CT only versus CT + MRI in consensus reading with a radiologist. Material and methods: the prostate and seminal vesicles of 13 patients treated with intensity-modulated radiotherapy for prostatic adenocarcinoma were retrospectively delineated by three radiation oncologists on CT only and on CT + MRI in consensus reading with a radiologist. The volumes and margin positions were calculated and intermodality and interobserver variations were assessed for the clinical target volume (CTV), seminal vesicles, prostate and three prostatic subdivisions (apical, middle and basal third). Results: using CT + MRI as compared to CT alone, the mean CTV, prostate and seminal vesicle volumes significantly decreased by 6.54%, 5.21% and 10.47%, respectively. More importantly, their standard deviations significantly decreased by 63.06%, 62.65% and 44.83%, respectively. The highest level of variation was found at the prostatic apex, followed by the prostatic base and seminal vesicles. Conclusion: addition of MRI to CT in consensus reading with a radiologist results in a moderate decrease of the CTV, but an important decrease of the interobserver delineation variation, especially at the prostatic apex. (orig.)

  7. 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. Copyright © 2014 by Duke University Press.

  8. 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.

  9. Individual differences in posterior cortical volume correlate with proneness to pride and gratitude.

    Science.gov (United States)

    Zahn, Roland; Garrido, Griselda; Moll, Jorge; Grafman, Jordan

    2014-11-01

    Proneness to specific moral sentiments (e.g. pride, gratitude, guilt, indignation) has been linked with individual variations in functional MRI (fMRI) response within anterior brain regions whose lesion leads to inappropriate behaviour. However, the role of structural anatomical differences in rendering individuals prone to particular moral sentiments relative to others is unknown. Here, we investigated grey matter volumes (VBM8) and proneness to specific moral sentiments on a well-controlled experimental task in healthy individuals. Individuals with smaller cuneus, and precuneus volumes were more pride-prone, whereas those with larger right inferior temporal volumes experienced gratitude more readily. Although the primary analysis detected no associations with guilt- or indignation-proneness, subgenual cingulate fMRI responses to guilt were negatively correlated with grey matter volumes in the left superior temporal sulcus and anterior dorsolateral prefrontal cortices (right >left). This shows that individual variations in functional activations within critical areas for moral sentiments were not due to grey matter volume differences in the same areas. Grey matter volume differences between healthy individuals may nevertheless play an important role by affecting posterior cortical brain systems that are non-critical but supportive for the experience of specific moral sentiments. This may be of particular relevance when their experience depends on visuo-spatial elaboration. Published by Oxford University Press 2013. This work is written by US Government employees and is in the public domain in the US.

  10. Delivered volumes of enteral nutrition exceed prescribed volumes.

    Science.gov (United States)

    Walker, Renee Nichole; Utech, Anne; Velez, Maria Eugenia; Schwartz, Katie

    2014-10-01

    Enteral nutrition (EN) provisions are typically calculated based on a 24-hour infusion period. However, feedings are often interrupted for daily activities, procedures, or gastrointestinal intolerance. The study's objective was to determine the delivered EN quantities provided to stable hospitalized patients, using cellular time and measured volumes to verify our EN calculation adjustment. A supply of consecutively numbered ready-to-hang (RTH) EN product was delivered to the bedside of 26 inpatients with established EN tolerance at goal rates on various types of nursing units. The dietitian weighed the volume remaining in the infusing product and recorded the measurement time. On the following days, the dietitian continued to weigh the infusing RTH product and the empty RTH bottles saved by nursing. The primary outcome was the difference between the prescribed and delivered EN provisions, which was calculated with a paired t test. Patients received significantly more calories in the delivered enteral feeding (mean [SD], 1678 [385] kcal) than prescribed calories in the EN order (1489 [246 kcal]; t = 3.736, P = .001), adjusting for observed time. No significant differences were found between nursing units, product, and rate. EN delivered may actually exceed ordered amounts by 5%–21% (mean, 12%) with feeding pump inaccuracy as the primary contributing factor. This differs from what others have found. Our findings support using a volume-based ordering system vs a rate-based ordering system for more accurate EN delivery.

  11. Structure variations of pumpkin balloon

    Science.gov (United States)

    Yajima, N.; Izutsu, N.; Honda, H.

    2004-01-01

    A lobed pumpkin balloon by 3-D gore design concept is recognized as a basic form for a super-pressure balloon. This paper deals with extensions of this design concept for other large pressurized membrane structures, such as a stratospheric airship and a balloon of which volume is controllable. The structural modifications are performed by means of additional ropes, belts or a strut. When the original pumpkin shape is modified by these systems, the superior characteristics of the 3-D gore design, incorporating large bulges with a small local radius and unidirectional film tension, should be maintained. Improved design methods which are adequate for the above subjects will be discussed in detail. Application for ground structures are also mentioned.

  12. Importance of Local Structural Variations on Recrystallization

    DEFF Research Database (Denmark)

    Juul Jensen, Dorte; Lin, Fengxiang; Zhang, Yubin

    2013-01-01

    Effects of local variations in the deformation microstructure on subsequent recrystallization are discussed and illustrated by three examples. The three examples consider local variations on different length scales and are: 1. Effects of local variations in the deformation microstructure on the f...

  13. 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...

  14. 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.

  15. Effects of major geometric variations between intracavitary applications on pear-shaped isodose dimension in cancer of the cervix

    International Nuclear Information System (INIS)

    Kim, R. Y.

    1996-01-01

    PURPOSE: The basic principal of intracavitary brachytherapy for cancer of the cervix is based on specific loading rules to achieve a pear-shaped isodose distribution centered around the cervix. Recently, ICRU Report 38 recommends a dose reference volume for reporting. Our previous studies have confirmed that there is considerable variations of geometry between applications. This study is to evaluate the effect of major geometric variations on pear-shaped isodose dimension in manual afterloading low-dose-rate system. MATERIAL AND METHODS: One hundred orthogonal films of 50 patients with cancer of the cervix (2 applications/patient) were reviewed for comparative measurements of geometric variations between applications. Major geometric variations were found for 13 patients in lengths of tandem, 7 patients in colpostats separation and 16 patients in vaginal packing. The direct measurement of these geometric variations were compared with the three-dimensional measurement of the pear-shaped isodose enclosed by the point A between the two applications. RESULTS: The geometric variations in the width of colpostats separation and length of tandem were directly related to the width and height of the pear-shaped isodose dimension. The geometric relationship between the colpostats and distal tandem had an important effect on the thickness of the pear-shape. In optimization of poor geometry for rectum or bladder wall, high dose volume centered around the cervix is reduced without changing the overall pear-shaped volume due to changing configuration of the pear-shaped isodose. In our selected patients with two applications, variations in vaginal packing had no direct effect on the width and thickness of the pear-shape due to other variables. CONCLUSION: Major geometric variations between applications greatly affect the dimension of the pear-shaped isodose distribution. Optimization of poor geometry is quite limited without compromising the high-dose volume centered around the

  16. Variational 3D-PIV with sparse descriptors

    Science.gov (United States)

    Lasinger, Katrin; Vogel, Christoph; Pock, Thomas; Schindler, Konrad

    2018-06-01

    3D particle imaging velocimetry (3D-PIV) aims to recover the flow field in a volume of fluid, which has been seeded with tracer particles and observed from multiple camera viewpoints. The first step of 3D-PIV is to reconstruct the 3D locations of the tracer particles from synchronous views of the volume. We propose a new method for iterative particle reconstruction, in which the locations and intensities of all particles are inferred in one joint energy minimization. The energy function is designed to penalize deviations between the reconstructed 3D particles and the image evidence, while at the same time aiming for a sparse set of particles. We find that the new method, without any post-processing, achieves significantly cleaner particle volumes than a conventional, tomographic MART reconstruction, and can handle a wide range of particle densities. The second step of 3D-PIV is to then recover the dense motion field from two consecutive particle reconstructions. We propose a variational model, which makes it possible to directly include physical properties, such as incompressibility and viscosity, in the estimation of the motion field. To further exploit the sparse nature of the input data, we propose a novel, compact descriptor of the local particle layout. Hence, we avoid the memory-intensive storage of high-resolution intensity volumes. Our framework is generic and allows for a variety of different data costs (correlation measures) and regularizers. We quantitatively evaluate it with both the sum of squared differences and the normalized cross-correlation, respectively with both a hard and a soft version of the incompressibility constraint.

  17. Increased intracranial volume in Parkinson's disease

    DEFF Research Database (Denmark)

    Krabbe, Katja; Karlsborg, Merete; Hansen, Andreas

    2005-01-01

    segmentation and outlining of regions in order to identify regional volume changes that might be useful in the diagnosis of the two diseases. RESULTS: Patients with PD had significantly larger intracranial volumes (ICVs) and significantly smaller putaminal and sustantia nigra volumes than controls. MSA...... patients had significantly smaller substantia nigra and caudate volumes than controls but normal intracranial volume. In both patient groups there was a further trend towards smaller amygdala volumes. DISCUSSION: Increased ICV in PD patients is a new finding that may be explained by genetic factors...

  18. Retrospective Reconstructions of Active Bone Marrow Dose-Volume Histograms

    International Nuclear Information System (INIS)

    Veres, Cristina; Allodji, Rodrigue S.; Llanas, Damien; Vu Bezin, Jérémi; Chavaudra, Jean; Mège, Jean Pierre; Lefkopoulos, Dimitri; Quiniou, Eric; Deutsh, Eric; Vathaire, Florent de; Diallo, Ibrahima

    2014-01-01

    Purpose: To present a method for calculating dose-volume histograms (DVH's) to the active bone marrow (ABM) of patients who had undergone radiation therapy (RT) and subsequently developed leukemia. Methods and Materials: The study focuses on 15 patients treated between 1961 and 1996. Whole-body RT planning computed tomographic (CT) data were not available. We therefore generated representative whole-body CTs similar to patient anatomy. In addition, we developed a method enabling us to obtain information on the density distribution of ABM all over the skeleton. Dose could then be calculated in a series of points distributed all over the skeleton in such a way that their local density reflected age-specific data for ABM distribution. Dose to particular regions and dose-volume histograms of the entire ABM were estimated for all patients. Results: Depending on patient age, the total number of dose calculation points generated ranged from 1,190,970 to 4,108,524. The average dose to ABM ranged from 0.3 to 16.4 Gy. Dose-volume histograms analysis showed that the median doses (D 50% ) ranged from 0.06 to 12.8 Gy. We also evaluated the inhomogeneity of individual patient ABM dose distribution according to clinical situation. It was evident that the coefficient of variation of the dose for the whole ABM ranged from 1.0 to 5.7, which means that the standard deviation could be more than 5 times higher than the mean. Conclusions: For patients with available long-term follow-up data, our method provides reconstruction of dose-volume data comparable to detailed dose calculations, which have become standard in modern CT-based 3-dimensional RT planning. Our strategy of using dose-volume histograms offers new perspectives to retrospective epidemiological studies

  19. Optimally stopped variational quantum algorithms

    Science.gov (United States)

    Vinci, Walter; Shabani, Alireza

    2018-04-01

    Quantum processors promise a paradigm shift in high-performance computing which needs to be assessed by accurate benchmarking measures. In this article, we introduce a benchmark for the variational quantum algorithm (VQA), recently proposed as a heuristic algorithm for small-scale quantum processors. In VQA, a classical optimization algorithm guides the processor's quantum dynamics to yield the best solution for a given problem. A complete assessment of the scalability and competitiveness of VQA should take into account both the quality and the time of dynamics optimization. The method of optimal stopping, employed here, provides such an assessment by explicitly including time as a cost factor. Here, we showcase this measure for benchmarking VQA as a solver for some quadratic unconstrained binary optimization. Moreover, we show that a better choice for the cost function of the classical routine can significantly improve the performance of the VQA algorithm and even improve its scaling properties.

  20. Variational identities and Hamiltonian structures

    International Nuclear Information System (INIS)

    Ma Wenxiu

    2010-01-01

    This report is concerned with Hamiltonian structures of classical and super soliton hierarchies. In the classical case, basic tools are variational identities associated with continuous and discrete matrix spectral problems, targeted to soliton equations derived from zero curvature equations over general Lie algebras, both semisimple and non-semisimple. In the super case, a supertrace identity is presented for constructing Hamiltonian structures of super soliton equations associated with Lie superalgebras. We illustrate the general theories by the KdV hierarchy, the Volterra lattice hierarchy, the super AKNS hierarchy, and two hierarchies of dark KdV equations and dark Volterra lattices. The resulting Hamiltonian structures show the commutativity of each hierarchy discussed and thus the existence of infinitely many commuting symmetries and conservation laws.

  1. Circadian Variation Of Stroke Onset

    Directory of Open Access Journals (Sweden)

    Kamath vasantha

    2003-01-01

    Full Text Available Diurnal variations in various physiological and biochemical functions and certain pathological events like myocardial infarction and stroke have been documented. We studied prospectively one hundred and seven patients of acute onset stroke confirmed by computed tomography for the exact time of onset, risk factors and type of stroke. Patients who were unclear of time of onset and with a diagnosis of cerebral venous thrombosis or sub-arachnoid hemorrhage were excluded. Infarction was detected in 71 patients and hemorrhage in 33 patients. Men out numbered women (1:6:1. Hypertension was more frequent in hemorrhage in the morning time (5 AM-12 noon and more infarction between 12-6 pm. However there was no relation between the time of onset of stroke and various risk-factors of stroke.

  2. Generalized Multiparameters Fractional Variational Calculus

    Directory of Open Access Journals (Sweden)

    Om Prakash Agrawal

    2012-01-01

    Full Text Available This paper builds upon our recent paper on generalized fractional variational calculus (FVC. Here, we briefly review some of the fractional derivatives (FDs that we considered in the past to develop FVC. We first introduce new one parameter generalized fractional derivatives (GFDs which depend on two functions, and show that many of the one-parameter FDs considered in the past are special cases of the proposed GFDs. We develop several parts of FVC in terms of one parameter GFDs. We point out how many other parts could be developed using the properties of the one-parameter GFDs. Subsequently, we introduce two new two- and three-parameter GFDs. We introduce some of their properties, and discuss how they can be used to develop FVC. In addition, we indicate how these formulations could be used in various fields, and how the generalizations presented here can be further extended.

  3. Equilibrium models and variational inequalities

    CERN Document Server

    Konnov, Igor

    2007-01-01

    The concept of equilibrium plays a central role in various applied sciences, such as physics (especially, mechanics), economics, engineering, transportation, sociology, chemistry, biology and other fields. If one can formulate the equilibrium problem in the form of a mathematical model, solutions of the corresponding problem can be used for forecasting the future behavior of very complex systems and, also, for correcting the the current state of the system under control. This book presents a unifying look on different equilibrium concepts in economics, including several models from related sciences.- Presents a unifying look on different equilibrium concepts and also the present state of investigations in this field- Describes static and dynamic input-output models, Walras, Cassel-Wald, spatial price, auction market, oligopolistic equilibrium models, transportation and migration equilibrium models- Covers the basics of theory and solution methods both for the complementarity and variational inequality probl...

  4. Variation of the latissimus dorsi

    Directory of Open Access Journals (Sweden)

    Ishani P Shah

    2014-01-01

    Full Text Available A typical muscle variation of latissimus dorsi - the axillary arch is represented by the muscular or fibromuscular slip detached from the anteroinferior border of the musculus latissimus dorsi passing over the axilla under the axillary fascia crossing the medial side of the brachial plexus to continue as a septum intermusculare mediale brachii distally to the medial epicondyle of humerus. The full extent of the muscle is rarely present. Slips of muscle extend from the latissimus dorsi at the inferior angle of scapula to insert into pectoralis major (Langer, coracobrachilis, biceps or coracoid process forming what is described as a common variant - the muscular axillary arch. We report three cases of variants of latissimus dorsi, one of which has not been reported in the literature before.

  5. Variational transition-state theory

    International Nuclear Information System (INIS)

    Truhlar, D.G.; Garrett, B.C.

    1980-01-01

    A general introduction to and some results from studies of a procedure called variational transition-state theory are presented. A fundamental assumption of this theory is that the net rate of forward reaction at equilibrium equals the equilibrium flux in the product direction through the transition state where the transition state is a surface in phase space dividing reactants from products. Classical generalized-transition-state-theory calculations for nine collinear systems are compared to classical trajectory calculations. This new technique should provide useful insight into the successes and failures of the conventional theory and useful quantitative estimates of possible errors on the predictions of conventional transition-state theory. This should also contribute to a more accurate theory now available for the practical calculations of chemical reaction rates and thermochemical and structural interpretations of rate processes

  6. Goal-Directed Fluid Resuscitation Protocol Based on Arterial Waveform Analysis of Major Burn Patients in a Mass Burn Casualty.

    Science.gov (United States)

    Chiao, Hao-Yu; Chou, Chang-Yi; Tzeng, Yuan-Sheng; Wang, Chih-Hsin; Chen, Shyi-Gen; Dai, Niann-Tzyy

    2018-02-01

    Adequate fluid titration during the initial resuscitation period of major burn patients is crucial. This study aimed to evaluate the feasibility and efficacy of a goal-directed fluid resuscitation protocol that used hourly urine output plus the arterial waveform analysis FloTrac (Edwards LifeSciences, Irvine, Calif) system for major burns to avoid fluid overload. We conducted a retrospective cohort study of 43 major burn patients at the Tri-Service General Hospital after the Formosa Fun Coast Dust Explosion on June 27, 2015. Because of the limited capacity of intensive care units (ICUs), 23 intubated patients were transferred from the burn wards or emergency department to the ICU within 24 hours. Fluid administration was adjusted to achieve a urine output of 30 to 50 mL/h, cardiac index greater than 2.5 L/min/m, and stroke volume variation (SVV) less than 12%. The hourly crystalloid fluid infusion rate was titrated based on SVV and hourly urine output. Of the 23 critically burned patients admitted to the ICU, 13 patients who followed the goal-directed fluid resuscitation protocol within 12 hours postburn were included in the analysis. The mean age (years) was 21.8, and the mean total body surface area (TBSA) burned (%) was 68.0. The mean Revised Baux score was 106.8. All patients sustained inhalation injury. The fluid volumes administered to patients in the first 24 hours and the second 24 hours (mL/kg/% total body surface area) were 3.62 ± 1.23 and 2.89 ± 0.79, respectively. The urine outputs in the first 24 hours and the second 24 hours (mL/kg/h) were 1.13 ± 0.66 and 1.53 ± 0.87, respectively. All patients achieved the established goals within 32 hours postburn. In-hospital mortality rate was 0%. The SVV-based goal-directed fluid resuscitation protocol leads to less unnecessary fluid administration during the early resuscitation phase. Clinicians can efficaciously manage the dynamic body fluid changes in major burn patients under the guidance of the protocol.

  7. Waste minimization handbook, Volume 1

    International Nuclear Information System (INIS)

    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

  8. 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.

  9. Sensors, Volume 4, Thermal Sensors

    Science.gov (United States)

    Scholz, Jorg; Ricolfi, Teresio

    1996-12-01

    'Sensors' is the first self-contained series to deal with the whole area of sensors. It describes general aspects, technical and physical fundamentals, construction, function, applications and developments of the various types of sensors. This volume describes the construction and applicational aspects of thermal sensors while presenting a rigorous treatment of the underlying physical principles. It provides a unique overview of the various categories of sensors as well as of specific groups, e.g. temperature sensors (resistance thermometers, thermocouples, and radiation thermometers), noise and acoustic thermometers, heat-flow and mass-flow sensors. Specific facettes of applications are presented by specialists from different fields including process control, automotive technology and cryogenics. This volume is an indispensable reference work and text book for both specialists and newcomers, researchers and developers.

  10. Basketball training increases striatum volume.

    Science.gov (United States)

    Park, In Sung; Lee, Kea Joo; Han, Jong Woo; Lee, Nam Joon; Lee, Won Teak; Park, Kyung Ah; Rhyu, Im Joo

    2011-02-01

    The striatum is associated with the learning and retention of motor skills. Several studies have shown that motor learning induces neuronal changes in the striatum. We investigated whether macroscopic change in striatum volume occurs in a segment of the human population who learned basketball-related motor skills and practiced them throughout their entire athletic life. Three-dimensional magnetic resonance imaging volumetry was performed in basketball players and healthy controls, and striatum volumes were compared based on basketball proficiency, region and side. We identified morphological enlargement in the striatum of basketball players in comparison with controls. Our results suggest that continued practice and repetitive performance of basketball-related motor skills may induce plastic structural changes in the human striatum. Copyright © 2010 Elsevier B.V. All rights reserved.

  11. Variational methods for field theories

    Energy Technology Data Exchange (ETDEWEB)

    Ben-Menahem, S.

    1986-09-01

    Four field theory models are studied: Periodic Quantum Electrodynamics (PQED) in (2 + 1) dimensions, free scalar field theory in (1 + 1) dimensions, the Quantum XY model in (1 + 1) dimensions, and the (1 + 1) dimensional Ising model in a transverse magnetic field. The last three parts deal exclusively with variational methods; the PQED part involves mainly the path-integral approach. The PQED calculation results in a better understanding of the connection between electric confinement through monopole screening, and confinement through tunneling between degenerate vacua. This includes a better quantitative agreement for the string tensions in the two approaches. Free field theory is used as a laboratory for a new variational blocking-truncation approximation, in which the high-frequency modes in a block are truncated to wave functions that depend on the slower background modes (Boron-Oppenheimer approximation). This ''adiabatic truncation'' method gives very accurate results for ground-state energy density and correlation functions. Various adiabatic schemes, with one variable kept per site and then two variables per site, are used. For the XY model, several trial wave functions for the ground state are explored, with an emphasis on the periodic Gaussian. A connection is established with the vortex Coulomb gas of the Euclidean path integral approach. The approximations used are taken from the realms of statistical mechanics (mean field approximation, transfer-matrix methods) and of quantum mechanics (iterative blocking schemes). In developing blocking schemes based on continuous variables, problems due to the periodicity of the model were solved. Our results exhibit an order-disorder phase transition. The transfer-matrix method is used to find a good (non-blocking) trial ground state for the Ising model in a transverse magnetic field in (1 + 1) dimensions.

  12. MDCT evaluation of sternal variations: Pictorial essay

    International Nuclear Information System (INIS)

    Duraikannu, Chary; Noronha, Olma V; Sundarrajan, Pushparajan

    2016-01-01

    Sternal variations and anomalies have been identified in the past during autopsy or cadaveric studies. Recently, an increasing number of minor sternal variations have been reported with the advent of multidetector computed tomography (CT). Although there are many sternal variations that occur with varying appearance and prevalence, most of them are not recognized or are underreported during routine imaging of thorax. Identification of sternal variations is important to differentiate from pathological conditions and to prevent fatal complications prior to sternal interventions like marrow aspiration or acupuncture. This article aims to describe the minor and asymptomatic sternal variations by multidetector CT and their clinical significance

  13. Volume stumbles; prices hold steady

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    This article is the July 1994 uranium market summary. During this period, spot market volume slid to just under 370,000 lbs U3O8 equivalent. In total, six deals took place; four in the spot market, none in the medium and long-term market, one in the conversion market, and one in the enrichment market, The low end of the unrestricted price range strengthened a bit. All other prices were unchanged

  14. Indigenous high volume air sampler

    International Nuclear Information System (INIS)

    Kotrappa, P.; Setty, N.P.N.; Raghunath, B.; Sivasubrahmanyam, P.S.

    1978-01-01

    A high volume air sampler for use in assessing concentrations of low levels of air borne particulates has been fabricated. The sampler will be of use in radioactive installations, conventional industries and environmental pollution analysis. It is comparable in performance with the imported Staplex air samplers. A turbine and motor system similar to the one found in conventional vacuum cleaners is used in its design. The sampler units can be produced in large numbers. (M.G.B.)

  15. [Fluctuations in biophysical measurements as a result of variations in solar activity].

    Science.gov (United States)

    Peterson, T F

    1995-01-01

    A theory is proposed to explain variations in the net electrical charge of biological substances at the Earth's surface. These are shown to occur in association with changes in the solar wind and geomagnetic field. It is suggested that a liquid dielectric's net volume charge will imitate pH effects, influence chemical reaction rates, and alter ion transfer mechanisms in biophysical systems. An experiment is described which measures dielectric volume charge, or non-neutrality, to allow correlation of this property with daily, 28-day, and 11-year fluctuation patterns in geophysical and satellite data associated with solar activity and the interplanetary magnetic field.

  16. Interobserver variation in measurements of Cesarean scar defect and myometrium with 3D ultrasonography

    DEFF Research Database (Denmark)

    Madsen, Lene Duch; Glavind, Julie; Uldbjerg, Niels

    Objectives: To evaluate the Cesarean scar defect depth and the residual myometrial thickness with 3-dimensional (3D) sonography concerning interobserver variation. Methods: Ten women were randomly selected from a larger cohort of Cesarean scar ultrasound evaluations. All women were examined 6......-16 months after their first Cesarean section with 2D transvaginal sonography and had 3D volumes recorded. Two observers independently evaluated “off-line” each of the 3D volumes stored. Residual myometrial thickness (RMT) and Cesarean scar defect depth (D) was measured in the sagittal plane with an interval...... of Cesarean section scar size and residual myometrium needs further investigation....

  17. Lung volume reduction for emphysema.

    Science.gov (United States)

    Shah, Pallav L; Herth, Felix J; van Geffen, Wouter H; Deslee, Gaetan; Slebos, Dirk-Jan

    2017-02-01

    Advanced emphysema is a lung disease in which alveolar capillary units are destroyed and supporting tissue is lost. The combined effect of reduced gas exchange and changes in airway dynamics impairs expiratory airflow and leads to progressive air trapping. Pharmacological therapies have limited effects. Surgical resection of the most destroyed sections of the lung can improve pulmonary function and exercise capacity but its benefit is tempered by significant morbidity. This issue stimulated a search for novel approaches to lung volume reduction. Alternative minimally invasive approaches using bronchoscopic techniques including valves, coils, vapour thermal ablation, and sclerosant agents have been at the forefront of these developments. Insertion of endobronchial valves in selected patients could have benefits that are comparable with lung volume reduction surgery. Endobronchial coils might have a role in the treatment of patients with emphysema with severe hyperinflation and less parenchymal destruction. Use of vapour thermal energy or a sclerosant might allow focal treatment but the unpredictability of the inflammatory response limits their current use. In this Review, we aim to summarise clinical trial evidence on lung volume reduction and provide guidance on patient selection for available therapies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. 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...

  19. When high-volume PCI operators in high-volume hospitals move to lower volume hospitals-Do they still maintain high volume and quality of outcomes?

    Science.gov (United States)

    Lu, Tsung-Hsueh; Li, Sheng-Tun; Liang, Fu-Wen; Lee, Jo-Chi; Yin, Wei-Hsian

    2017-10-31

    The aim of this quasi-experimental study was to examine whether high-volume percutaneous coronary intervention (PCI) operators still maintain high volume and quality of outcomes when they moved to lower volume hospitals. Systematic reviews have indicated that high-volume PCI operators and hospitals have higher quality outcomes. However, little is known on whether high PCI volume and high quality outcomes are mainly due to operator characteristics (i.e., skill and experience) and is portable across organizations or whether it is due to hospital characteristics (i.e., equipment, team, and management system) and is less portable. We used Taiwan National Health Insurance claims data 2000-2012 to identify 98 high-volume PCI operators, 10 of whom moved from one hospital to another during the study period. We compared the PCI volume, risk-adjusted mortality ratio, and major adverse cardiovascular event (MACE) ratio before and after moving. Of the 10 high-volume operators who moved, 6 moved from high- to moderate- or low-volume hospitals, with median annual PCI volumes (interquartile range) of 130 (117-165) in prior hospitals and 54 (46-84) in subsequent hospitals (the hospital the operator moved to), and the remaining 4 moved from high to high-volume hospitals, with median annual PCI volumes (interquartile range) of 151 (133-162) in prior hospitals and 193 (178-239) in subsequent hospitals. No significant differences were observed in the risk-adjusted mortality ratios and MACE ratios between high-volume operators and matched controls before and after moving. High-volume operators cannot maintain high volume when they moved from high to moderate or low-volume hospitals; however, the quality of care is maintained. High PCI volume and high-quality outcomes are less portable and more hospital bound. © 2017 Wiley Periodicals, Inc.

  20. Accommodating variation: dialects, idiolects, and speech processing.

    Science.gov (United States)

    Kraljic, Tanya; Brennan, Susan E; Samuel, Arthur G

    2008-04-01

    Listeners are faced with enormous variation in pronunciation, yet they rarely have difficulty understanding speech. Although much research has been devoted to figuring out how listeners deal with variability, virtually none (outside of sociolinguistics) has focused on the source of the variation itself. The current experiments explore whether different kinds of variation lead to different cognitive and behavioral adjustments. Specifically, we compare adjustments to the same acoustic consequence when it is due to context-independent variation (resulting from articulatory properties unique to a speaker) versus context-conditioned variation (resulting from common articulatory properties of speakers who share a dialect). The contrasting results for these two cases show that the source of a particular acoustic-phonetic variation affects how that variation is handled by the perceptual system. We also show that changes in perceptual representations do not necessarily lead to changes in production.

  1. Matter tensor from the Hilbert variational principle

    International Nuclear Information System (INIS)

    Pandres, D. Jr.

    1976-01-01

    We consider the Hilbert variational principle which is conventionally used to derive Einstein's equations for the source-free gravitational field. We show that at least one version of the equivalence principle suggests an alternative way of performing the variation, resulting in a different set of Einstein equations with sources automatically present. This illustrates a technique which may be applied to any theory that is derived from a variational principle and that admits a gauge group. The essential point is that, if one first imposes a gauge condition and then performs the variation, one obtains field equations with source terms which do not appear if one first performs the variation and then imposes the gauge condition. A second illustration is provided by the variational principle conventionally used to derive Maxwell's equations for the source-free electromagnetic field. If one first imposes the Lorentz gauge condition and then performs the variation, one obtains Maxwell's equations with sources present

  2. Improving volume loss estimates of the northwestern Greenland Ice Sheet 2002-2010

    DEFF Research Database (Denmark)

    Korsgaard, Niels Jákup; Khan, Shfaqat Abbas; Kjeldsen, Kristian Kjellerup

    Studies have been carried out using various methods to estimate the Greenland ice sheet mass balance. Remote sensing techniques used to determine the ice sheet volume includes airborne and satellite radar and laser methods and measurements of ice flow of outlet glaciers use InSAR satellite radar......) does not work on sloping surfaces and is affected by radar penetration into the snow. InSAR estimates require knowledge of outlet glacier thickness. GRACE has limited spatial resolution and is affected by mass variations not just from ice changes, but also from hydrologic and ocean mass variability...... and mass redistribution within the solid Earth. The accuracy of ice mass and ice volume estimates can be assessed by comparing results from different techniques. Here, we focus on volume loss estimates from ICESat, ATM and LVIS data. We estimate catchment-wide ice volume change in northwest Greenland...

  3. Transient regimes during high-temperature deformation of a bulk metallic glass: A free volume approach

    International Nuclear Information System (INIS)

    Bletry, M.; Guyot, P.; Brechet, Y.; Blandin, J.J.; Soubeyroux, J.L.

    2007-01-01

    The homogeneous deformation of a zirconium-based bulk metallic glass is investigated in the glass transition range. Compression and stress-relaxation tests have been conducted. The stress-strain curves are modeled in the framework of the free volume theory, including transient phenomena (overshoot and undershoot). This approach allows several physical parameters (activation volume, flow defect creation and relaxation coefficient) to be determined from a mechanical experiment. This model is able to rationalize the dependency of stress overshoot on relaxation time. It is shown that, due to the relationship between flow defect concentration and free volume model, it is impossible to determine the equilibrium flow defect concentration. However, the relative variation of flow defect is always the same, and all the model parameters depend on the equilibrium flow defect concentration. The methodology presented in this paper should, in the future, allow the consistency of the free volume model to be assessed

  4. 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

  5. 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....

  6. 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....

  7. 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....

  8. Timing of low tidal volume ventilation and intensive care unit mortality in acute respiratory distress syndrome. A prospective cohort study.

    Science.gov (United States)

    Needham, Dale M; Yang, Ting; Dinglas, Victor D; Mendez-Tellez, Pedro A; Shanholtz, Carl; Sevransky, Jonathan E; Brower, Roy G; Pronovost, Peter J; Colantuoni, Elizabeth

    2015-01-15

    Reducing tidal volume decreases mortality in acute respiratory distress syndrome (ARDS). However, the effect of the timing of low tidal volume ventilation is not well understood. To evaluate the association of intensive care unit (ICU) mortality with initial tidal volume and with tidal volume change over time. Multivariable, time-varying Cox regression analysis of a multisite, prospective study of 482 patients with ARDS with 11,558 twice-daily tidal volume assessments (evaluated in milliliter per kilogram of predicted body weight [PBW]) and daily assessment of other mortality predictors. An increase of 1 ml/kg PBW in initial tidal volume was associated with a 23% increase in ICU mortality risk (adjusted hazard ratio, 1.23; 95% confidence interval [CI], 1.06-1.44; P = 0.008). Moreover, a 1 ml/kg PBW increase in subsequent tidal volumes compared with the initial tidal volume was associated with a 15% increase in mortality risk (adjusted hazard ratio, 1.15; 95% CI, 1.02-1.29; P = 0.019). Compared with a prototypical patient receiving 8 days with a tidal volume of 6 ml/kg PBW, the absolute increase in ICU mortality (95% CI) of receiving 10 and 8 ml/kg PBW, respectively, across all 8 days was 7.2% (3.0-13.0%) and 2.7% (1.2-4.6%). In scenarios with variation in tidal volume over the 8-day period, mortality was higher when a larger volume was used earlier. Higher tidal volumes shortly after ARDS onset were associated with a greater risk of ICU mortality compared with subsequent tidal volumes. Timely recognition of ARDS and adherence to low tidal volume ventilation is important for reducing mortality. Clinical trial registered with www.clinicaltrials.gov (NCT 00300248).

  9. Time variations in geomagnetic intensity

    Science.gov (United States)

    Valet, Jean-Pierre

    2003-03-01

    After many years spent by paleomagnetists studying the directional behavior of the Earth's magnetic field at all possible timescales, detailed measurements of field intensity are now needed to document the variations of the entire vector and to analyze the time evolution of the field components. A significant step has been achieved by combining intensity records derived from archeological materials and from lava flows in order to extract the global field changes over the past 12 kyr. A second significant step was due to the emergence of coherent records of relative paleointensity using the remanent magnetization of sediments to retrace the evolution of the dipole field. A third step was the juxtaposition of these signals with those derived from cosmogenic isotopes. Contemporaneous with the acquisition of records, new techniques have been developed to constrain the geomagnetic origin of the signals. Much activity has also been devoted to improving the quality of determinations of absolute paleointensity from volcanic rocks with new materials, proper selection of samples, and investigations of complex changes in magnetization during laboratory experiments. Altogether these developments brought us from a situation where the field changes were restricted to the past 40 kyr to the emergence of a coherent picture of the changes in the geomagnetic dipole moment for at least the past 1 Myr. On longer timescales the field variability and its average behavior is relatively well documented for the past 400 Myr. Section 3 gives a summary of most methods and techniques that are presently used to track the field intensity changes in the past. In each case, current limits and potential promises are discussed. The section 4 describes the field variations measured so far over various timescales covered by the archeomagnetic and the paleomagnetic records. Preference has always been given to composite records and databases in order to extract and discuss major and global geomagnetic

  10. Variations in inpatient pediatric anesthesia in California from 2000 to 2009: a caseload and geographic analysis.

    Science.gov (United States)

    Mudumbai, Seshadri C; Honkanen, Anita; Chan, Jia; Schmitt, Susan; Saynina, Olga; Hackel, Alvin; Gregory, George; Phibbs, Ciaran S; Wise, Paul H

    2014-12-01

    Regional referral systems are considered important for children hospitalized for surgery, but there is little information on existing systems. To examine geographic variations in anesthetic caseloads in California for surgical inpatients ≤6 years and to evaluate the feasibility of regionalizing anesthetic care. We reviewed California's unmasked patient discharge database between 2000 and 2009 to determine surgical procedures, dates, and inpatient anesthetic caseloads. Hospitals were classified as urban or rural and were further stratified as low, intermediate, high, and very high volume. We reviewed 257,541 anesthetic cases from 402 hospitals. Seventeen California Children's Services (CCS) hospitals conducted about two-thirds of all inpatient anesthetics; 385 non-CCS hospitals accounted for the rest. Urban hospitals comprised 82% of low- and intermediate-volume centers (n = 297) and 100% of the high- and very high-volume centers (n = 41). Ninety percent (n = 361) of hospitals performed risk procedures such as appendectomies were the most frequent in urban low- and intermediate-volume hospitals, fairly complex neurosurgical and general surgeries were also performed. The median distance from urban lower-volume hospitals to the nearest high- or very high-volume center was 12 miles. Up to 98% (n = 40,316) of inpatient anesthetics at low- or intermediate-volume centers could have been transferred to higher-volume centers within 25 miles of smaller centers. Many urban California hospitals maintained low annual inpatient anesthetic caseloads for children ≤6 years while conducting potentially more complex procedures. Further efforts are necessary to define the scope of pediatric anesthetic care at urban low- and intermediate-volume hospitals in California. © 2014 John Wiley & Sons Ltd.

  11. 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…

  12. 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.

  13. Mineral Density Volume Gradients in Normal and Diseased Human Tissues

    Science.gov (United States)

    Djomehri, Sabra I.; Candell, Susan; Case, Thomas; Browning, Alyssa; Marshall, Grayson W.; Yun, Wenbing; Lau, S. H.; Webb, Samuel; Ho, Sunita P.

    2015-01-01

    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: 2820-3095mg/cc, bone: 570-1415mg/cc, cementum: 1240-1340mg/cc, dentin: 1480-1590mg/cc, cementum affected by periodontitis: 1100-1220mg/cc, hypomineralized carious dentin: 345-1450mg/cc, hypermineralized carious dentin: 1815-2740mg/cc, and dental calculus: 1290-1770mg/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. PMID:25856386

  14. 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.

  15. PLURILINGUAL COMPETENCE, STYLES AND VARIATION

    Directory of Open Access Journals (Sweden)

    Jyrki Kalliokoski

    2011-01-01

    Full Text Available The paper explores plurilingual competence in respect to language proficiency, language education and pluri- and multilingualism. The notion of communicative competence was introduced by Hymes (1972 as a reaction to chomskyan view of language as an autonomous system. Hymes’ notion of communicative competence originally included plurilingualism. The concept of communicative competence was quickly adopted to applied linguistics but the idea of a linguistic repertoire consisting of the competencies of linguistic varieties was not imported to SLA or language testing. The Hymesian perspective to plurilingualism as an essential dimension of communicative competence was revived in the Common European Framework (CEFR. However,the practice of applying the CEFR has mostly neglected the dimension on plurilingualism and plurilingual competence. The focus in the use of the CEFR has been on the different areas of language skills within one single language at a time, while the application of plurilingual practices has gained very little attention. The Hymesian notion of communicative competence has lived on in the sociolinguistic research tradition, especially within interactional sociolinguistics. The present paper relates the notion of plurilingual competence to its hymesian origin, to recent trends in plurilingual and pluricultural education, and to the sociolinguistic study of style and linguistic variation in multilingual communities. The article uses Finnish L2 data to show how plurilingual competence is used as an interactional resource.From the perspective of language learning, plurilingual competence enables speakers with different linguistic backgrounds to use their shared linguistic repertoire in order to ensure smooth interaction and achieve mutual understanding.

  16. Isotopic variations in primitive meteorites

    International Nuclear Information System (INIS)

    Clayton, R.N.; Chicago Univ., IL; Chicago Univ., IL

    1981-01-01

    The presence of large internal 16 O variability in ordinary chondrites greatly extends the range of meteorite types in which this phenomenon has been observed. These results may lead to identification of major gas and dust reservoirs in the cloud from which the Solar System formed. The demonstration that live 107 Pd was present in the differentiated parent bodies of some iron meteorites supports the million year time scale between a major nucleosynthetic event and Solar System formation, as implied by the presence of live 26 Al in carbonaceous chondrites. However, the variability of radiogenic 26 Mg abundances in these meteorites makes it clear that the data cannot be interpreted simply in terms of time variations. Models of nucleosynthesis for elements from calcium to the iron peak should be aided by the new observations of abundances of titanium isotopes. Progress has been made in establishing the carrier phases of isotopically anomalous xenon and krypton. The apparent location of anomalous xenon and 14 N-rich nitrogen in identical carriers supports the notion that nucleosynthetic anomalies in nitrogen are also present in Allende. (author)

  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. The Oxford History of English Lexicography. Volume I: General ...

    African Journals Online (AJOL)

    A.P. Cowie (Editor). The Oxford History of English Lexicography. Volume I: General-purpose Dictionaries. Volume II: Specialized Dictionaries. 2009. Volume I: xviii + 467 pp., Volume II: xix + 551 pp. ISBN Volume I–II: 978-0-19-928562-4. Volume I: 978-0-19-928560-0. Volume II: 978-0-19-928561-7. Oxford: Oxford University ...

  19. Psychopathic traits are associated with cortical and subcortical volume alterations in healthy individuals.

    Science.gov (United States)

    Vieira, Joana B; Ferreira-Santos, Fernando; Almeida, Pedro R; Barbosa, Fernando; Marques-Teixeira, João; Marsh, Abigail A

    2015-12-01

    Research suggests psychopathy is associated with structural brain alterations that may contribute to the affective and interpersonal deficits frequently observed in individuals with high psychopathic traits. However, the regional alterations related to different components of psychopathy are still unclear. We used voxel-based morphometry to characterize the structural correlates of psychopathy in a sample of 35 healthy adults assessed with the Triarchic Psychopathy Measure. Furthermore, we examined the regional grey matter alterations associated with the components described by the triarchic model. Our results showed that, after accounting for variation in total intracranial volume, age and IQ, overall psychopathy was negatively associated with grey matter volume in the left putamen and amygdala. Additional regression analysis with anatomical regions of interests revealed total triPM score was also associated with increased lateral orbitofrontal cortex (OFC) and caudate volume. Boldness was positively associated with volume in the right insula. Meanness was positively associated with lateral OFC and striatum volume, and negatively associated with amygdala volume. Finally, disinhibition was negatively associated with amygdala volume. Results highlight the contribution of both subcortical and cortical brain alterations for subclinical psychopathy and are discussed in light of prior research and theoretical accounts about the neurobiological bases of psychopathic traits. © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  20. Evaluation of the accuracy of volume determination on the orbit and eyeball using MRI

    International Nuclear Information System (INIS)

    Chau, Anson; Fung, Karl; Yap, Maurice

    2005-01-01

    Purpose: This study reports a calibration carried out on phantoms simulating the orbit and eyeball to evaluate the accuracy of volumetric determination using MRI DICOM (Digital Imaging and Communication in Medicine) images. Methods: Ten tailor-made spherical silicon balls ranging in size from 5 to 14 cm 3 and 10 silicon moulds of orbits from 10 human dried skulls were used to simulate the eyes and orbits, respectively. The CISS (Constructive interference in steady state, TR/TE = 16/8 ms) T2-weighted sequence was taken using a Siemens MRI scanner. The volume of each phantom was computed and compared with the known physical volumes. Results: The computed and physical volumes were highly correlated for both eyeball (r = 0.997) and the orbit (r = 0.992) phantoms. Coefficients of variation of the computed and physical volumes were low. Consequently, it is possible to apply a calibration value to the computed volume to derive the physical volume with a high level of confidence. Conclusion: We conclude that with appropriate calibration, it is viable to use MRI DICOM images to derive the volume of the eyeball and the orbit