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Sample records for a1c-derived average glucose

  1. The proposed terminology 'A(1c)-derived average glucose' is inherently imprecise and should not be adopted.

    PubMed

    Bloomgarden, Z T; Inzucchi, S E; Karnieli, E; Le Roith, D

    2008-07-01

    The proposed use of a more precise standard for glycated (A(1c)) and non-glycated haemoglobin would lead to an A(1c) value, when expressed as a percentage, that is lower than that currently in use. One approach advocated to address the potential confusion that would ensue is to replace 'HbA(1c)' with a new term, 'A(1c)-derived average glucose.' We review evidence from several sources suggesting that A(1c) is, in fact, inherently imprecise as a measure of average glucose, so that the proposed terminology should not be adopted.

  2. An elevated gap between admission and A1C-derived average glucose levels is associated with adverse outcomes in diabetic patients with pyogenic liver abscess.

    PubMed

    Liao, Wen-I; Sheu, Wayne Huey-Herng; Chang, Wei-Chou; Hsu, Chin-Wang; Chen, Yu-Long; Tsai, Shih-Hung

    2013-01-01

    To assess whether chronic glycemic control and stress-induced hyperglycemia, determined by the gap between admission glucose levels and A1C-derived average glucose (ADAG) levels adversely affects outcomes in diabetic patients with pyogenic liver abscess (PLA). Clinical, laboratory, and multi-detector computed tomography (MDCT) findings of 329 PLA patients (2004-2010) were retrospectively reviewed. HbA1C levels were used to determine long-term glycemic control status, which were then converted to estimated average glucose values. For the gap between admission glucose levels and ADAG levels, we used receiver operating characteristic (ROC) curve to determine the optimal cut-off values predicting adverse outcomes. Univariate and multivariate logistic regressions were used to identify predictors of adverse outcomes. Diabetic PLA patients with poorer glycemic control had significantly higher Klebsiella pneumoniae (KP) infection rates, lower albumin levels, and longer hospital stays than those with suboptimal and good glycemic control. The ROC curve showed that a glycemic gap of 72 mg/dL was the optimal cut-off value for predicting adverse outcomes and showed a 22.3% relative increase in adverse outcomes compared with a glycemic gap<72 mg/dL. Multivariate analysis revealed that an elevated glycemic gap≥72 mg/dL was important predictor of adverse outcomes. A glycemic gap≥72 mg/dL, rather than admission hyperglycemia or chronic glycemic control, was significantly correlated with adverse outcomes in diabetic PLA patients. Poorer chronic glycemic control in diabetic PLA patients is associated with high incidence of KP infection, hypoalbuminemia and longer hospital stay.

  3. Translating HbA1c measurements into estimated average glucose values in pregnant women with diabetes.

    PubMed

    Law, Graham R; Gilthorpe, Mark S; Secher, Anna L; Temple, Rosemary; Bilous, Rudolf; Mathiesen, Elisabeth R; Murphy, Helen R; Scott, Eleanor M

    2017-04-01

    This study aimed to examine the relationship between average glucose levels, assessed by continuous glucose monitoring (CGM), and HbA 1c levels in pregnant women with diabetes to determine whether calculations of standard estimated average glucose (eAG) levels from HbA 1c measurements are applicable to pregnant women with diabetes. CGM data from 117 pregnant women (89 women with type 1 diabetes; 28 women with type 2 diabetes) were analysed. Average glucose levels were calculated from 5-7 day CGM profiles (mean 1275 glucose values per profile) and paired with a corresponding (±1 week) HbA 1c measure. In total, 688 average glucose-HbA 1c pairs were obtained across pregnancy (mean six pairs per participant). Average glucose level was used as the dependent variable in a regression model. Covariates were gestational week, study centre and HbA 1c . There was a strong association between HbA 1c and average glucose values in pregnancy (coefficient 0.67 [95% CI 0.57, 0.78]), i.e. a 1% (11 mmol/mol) difference in HbA 1c corresponded to a 0.67 mmol/l difference in average glucose. The random effects model that included gestational week as a curvilinear (quadratic) covariate fitted best, allowing calculation of a pregnancy-specific eAG (PeAG). This showed that an HbA 1c of 8.0% (64 mmol/mol) gave a PeAG of 7.4-7.7 mmol/l (depending on gestational week), compared with a standard eAG of 10.2 mmol/l. The PeAG associated with maintaining an HbA 1c level of 6.0% (42 mmol/mol) during pregnancy was between 6.4 and 6.7 mmol/l, depending on gestational week. The HbA 1c -average glucose relationship is altered by pregnancy. Routinely generated standard eAG values do not account for this difference between pregnant and non-pregnant individuals and, thus, should not be used during pregnancy. Instead, the PeAG values deduced in the current study are recommended for antenatal clinical care.

  4. HBA1C AND MEAN GLUCOSE DERIVED FROM SHORT-TERM CONTINUOUS GLUCOSE MONITORING ASSESSMENT DO NOT CORRELATE IN PATIENTS WITH HBA1C >8.

    PubMed

    Yamada, Eijiro; Okada, Shuichi; Nakajima, Yasuyo; Bastie, Claire C; Vatish, Manu; Tagaya, Yuko; Osaki, Aya; Shimoda, Yoko; Shibusawa, Ryo; Saito, Tsugumichi; Okamura, Takashi; Ozawa, Atsushi; Yamada, Masanobu

    2017-01-01

    Optimum therapy for patients with diabetes depends on both acute and long-term changes in plasma glucose, generally assessed by glycated hemoglobin (HbA1c) levels. However, the correlation between HbA1c and circulating glucose has not been fully determined. Therefore, we carefully examined this correlation when glucose levels were assessed by continuous glucose monitoring (CGM). Fifty-one patients (70% female, 30% male) were examined; among them were 28 with type 1 diabetes and 23 with type 2 diabetes. Clinically determined HbA1c levels were compared with blood glucose determined by CGM during a short time period. Changes in HbA1c levels up to 8.0% showed a clear and statistically strong correlation (R = 0.6713; P<.0001) with mean blood glucose levels measured by CGM, similar to that observed in the A1c-derived Average Glucose study in which patients were monitored for a longer period. However, we found no statistical correlation (R = 0.0498; P = .83) between HbA1c and CGM-assessed glucose levels in our patient population when HbA1c was >8.0%. Short-term CGM appears to be a good clinical indicator of long-term glucose control (HbA1c levels); however, cautions should be taken while interpreting CGM data from patients with HbA1c levels >8.0%. Over- or underestimation of the actual mean glucose from CGM data could potentially increase the risks of inappropriate treatment. As such, our results indicate that a more accurate analysis of CGM data might be useful to adequately tailor clinical treatments. ADAG = A1c-Derived Average Glucose CGM = continuous glucose monitoring %CV = percent coefficient of variation HbA1c = glycated hemoglobin.

  5. [IMPACT OF PERIOPERATIVE AVERAGE BLOOD-GLUCOSE LEVEL ON PROGNOSIS OF PATIENTS WITH HIP FRACTURE AND DIABETES MELLITUS].

    PubMed

    Wang, Guoqi; Long, Anhua; Zhang, Lihai; Zhang, Hao; Yin, Peng; Tang, Peifu

    2014-07-01

    To explore the impact of perioperative average blood-glucose level on the prognosis of patients with hip fracture and diabetes mellitus. A retrospective analysis was made on the clinical data of 244 patients with hip fracture and diabetes mellitus who accorded with the inclusion criteria between September 2009 and September 2012. Of 244 patients, 125 patients with poorly controlled fasting blood-glucose (average fasting blood-glucose level > 7.8 mmol/L) were assigned in group A, and 119 patients with well controlled fasting blood-glucose (average fasting blood-glucose level ≤ 7.8 mmol/L) were assigned in group B according to "China guideline for type 2 diabetes" criteria. There was no significant difference in gender, age, disease duration of diabetes mellitus, serum albumin, fracture type and disease duration, surgical procedure, anaesthesia, and complications between 2 groups (P > 0.05). Group A had a higher hemoglobin level and fewer patients who can do some outdoor activities than group B (t = -2.353, P = 0.020; χ2 = 4.333, P = 0.037). The hospitalization time, days to await surgery, stitch removal time, the postoperative complication rate, the mortality at 1 month and 1 year after operation, and ambulatory ability at 1 year after operation were compared between the 2 groups. A total of 223 patients (114 in group A and 109 in group B) were followed up 12-15 months (mean, 13.5 months). The days to await surgery of group A were significantly more than those of group B (t = -2.743, P=0.007), but no significant difference was found in hospitalization time and stitch removal time between 2 groups (P > 0.05). The postoperative complication rate of group A (19.2%, 24/125) was significantly higher than that of group B (8.4%, 10/119) (χ2 =5.926, P = 0.015). Group A had a higher mortality at 1 month after operation than group B (6.1% vs. 0) (χ2 = 5.038, P = 0.025), but no significant difference was shown at 1 year after operation between groups A and B (8.8% vs. 4

  6. Hemoglobin A1c Accurately Predicts Continuous Glucose Monitoring-Derived Average Glucose in Youth and Young Adults With Cystic Fibrosis.

    PubMed

    Chan, Christine L; Hope, Emma; Thurston, Jessica; Vigers, Timothy; Pyle, Laura; Zeitler, Philip S; Nadeau, Kristen J

    2018-04-19

    In cystic fibrosis (CF), HbA 1c is thought to underestimate glycemia. However, few studies have directly assessed the relationship between HbA 1c and average glucose in CF. We determined the relationships among glycemic markers-HbA 1c , fructosamine (FA), glycated albumin (%GA), and 1,5-anhydroglucitol (1,5-AG)-and continuous glucose monitoring (CGM) in CF, hypothesizing that alternate markers would better predict average sensor glucose (ASG) than HbA 1c . CF participants and a group of healthy control subjects (HC), ages 6-25 years, wore CGM for up to 7 days. Pearson correlations assessed the relationships between CGM variables and HbA 1c , FA, %GA, and 1,5-AG. The regression line between HbA 1c and ASG was compared in CF versus HC. Linear regressions determined whether alternate markers predicted ASG after adjustment for HbA 1c . CF ( n = 93) and HC ( n = 29) groups wore CGM for 5.2 ± 1 days. CF participants were 14 ± 3 years of age and 47% were male, with a BMI z score -0.1 ± 0.8 and no different from HCs in age, sex, or BMI. Mean HbA 1c in CF was 5.7 ± 0.8% (39 ± 9 mmol/mol) vs. HC 5.1 ± 0.2% (32 ± 2 mmol/mol) ( P < 0.0001). All glycemic markers correlated with ASG ( P ≤ 0.01): HbA 1c ( r = 0.86), FA ( r = 0.69), %GA ( r = 0.83), and 1,5-AG ( r = -0.26). The regression line between ASG and HbA 1c did not differ in CF versus HC ( P = 0.44). After adjustment for HbA 1c , %GA continued to predict ASG ( P = 0.0009) in CF. HbA 1c does not underestimate ASG in CF as previously assumed. No alternate glycemic marker correlated more strongly with ASG than HbA 1c . %GA shows strong correlation with ASG and added to the prediction of ASG beyond HbA 1c . However, we are not advocating use of HbA 1c for diabetes screening in CF based on these results. Further study will determine whether glycemic measures other than ASG differ among different types of diabetes for a given HbA 1c . © 2018 by the American Diabetes Association.

  7. The Ratio of Estimated Average Glucose to Fasting Plasma Glucose Level Is Superior to Glycated Albumin, Hemoglobin A1c, Fructosamine, and GA/A1c Ratio for Assessing β-Cell Function in Childhood Diabetes

    PubMed Central

    Lee, Ji Eun; Lee, Ji Woo; Fujii, Tatsuyoshi; Fujii, Noriyoshi; Choi, Jong Weon

    2014-01-01

    Objective. This study investigated the use of the estimated average glucose to fasting plasma glucose ratio (eAG/fPG ratio) to screen for β-cell function in pediatric diabetes. Methods. Glycated hemoglobin (HbA1c), glycated albumin (GA), fructosamine, insulin, and C-peptide levels were measured. The ratio of GA to HbA1c (GA/A1c ratio) was calculated, and the homeostasis model assessment of β-cell function (HOMA-β) was determined. Results. Median values of C-peptide, insulin, and HOMA-β levels were significantly higher in patients with an increased eAG/fPG ratio than in those with a decreased eAG/fPG ratio. C-peptide and HOMA-β levels were more closely correlated with the eAG/fPG ratio than with GA, HbA1c, the GA/A1c ratio, and fructosamine. In contrast, body mass index was significantly associated with GA, GA/A1c ratio, and fructosamine, but not with the eAG/fPG ratio and HbA1c levels. To test the diagnostic accuracies of the eAG/fPG ratio for identifying HOMA-β > 30.0% in patients with type 2 diabetes, the area under the ROC curve of the eAG/fPG ratio was significantly larger than that of the GA/A1c ratio [0.877 (95% CI, 0.780–0.942) versus 0.775 (95% CI, 0.664–0.865), P = 0.039]. Conclusions. A measurement of the eAG/fPG ratio may provide helpful information for assessing β-cell function in pediatric patients with diabetes. PMID:25013775

  8. Quaternion Averaging

    NASA Technical Reports Server (NTRS)

    Markley, F. Landis; Cheng, Yang; Crassidis, John L.; Oshman, Yaakov

    2007-01-01

    Many applications require an algorithm that averages quaternions in an optimal manner. For example, when combining the quaternion outputs of multiple star trackers having this output capability, it is desirable to properly average the quaternions without recomputing the attitude from the the raw star tracker data. Other applications requiring some sort of optimal quaternion averaging include particle filtering and multiple-model adaptive estimation, where weighted quaternions are used to determine the quaternion estimate. For spacecraft attitude estimation applications, derives an optimal averaging scheme to compute the average of a set of weighted attitude matrices using the singular value decomposition method. Focusing on a 4-dimensional quaternion Gaussian distribution on the unit hypersphere, provides an approach to computing the average quaternion by minimizing a quaternion cost function that is equivalent to the attitude matrix cost function Motivated by and extending its results, this Note derives an algorithm that deterniines an optimal average quaternion from a set of scalar- or matrix-weighted quaternions. Rirthermore, a sufficient condition for the uniqueness of the average quaternion, and the equivalence of the mininiization problem, stated herein, to maximum likelihood estimation, are shown.

  9. States' Average College Tuition.

    ERIC Educational Resources Information Center

    Eglin, Joseph J., Jr.; And Others

    This report presents statistical data on trends in tuition costs from 1980-81 through 1995-96. The average tuition for in-state undergraduate students of 4-year public colleges and universities for academic year 1995-96 was approximately 8.9 percent of median household income. This figure was obtained by dividing the students' average annual…

  10. Threaded average temperature thermocouple

    NASA Technical Reports Server (NTRS)

    Ward, Stanley W. (Inventor)

    1990-01-01

    A threaded average temperature thermocouple 11 is provided to measure the average temperature of a test situs of a test material 30. A ceramic insulator rod 15 with two parallel holes 17 and 18 through the length thereof is securely fitted in a cylinder 16, which is bored along the longitudinal axis of symmetry of threaded bolt 12. Threaded bolt 12 is composed of material having thermal properties similar to those of test material 30. Leads of a thermocouple wire 20 leading from a remotely situated temperature sensing device 35 are each fed through one of the holes 17 or 18, secured at head end 13 of ceramic insulator rod 15, and exit at tip end 14. Each lead of thermocouple wire 20 is bent into and secured in an opposite radial groove 25 in tip end 14 of threaded bolt 12. Resulting threaded average temperature thermocouple 11 is ready to be inserted into cylindrical receptacle 32. The tip end 14 of the threaded average temperature thermocouple 11 is in intimate contact with receptacle 32. A jam nut 36 secures the threaded average temperature thermocouple 11 to test material 30.

  11. Blood Test: Glucose

    MedlinePlus

    ... Videos for Educators Search English Español Blood Test: Glucose KidsHealth / For Parents / Blood Test: Glucose What's in ... liver or kidneys) is working. What Is a Glucose Test? A glucose test measures how much glucose ...

  12. Average Revisited in Context

    ERIC Educational Resources Information Center

    Watson, Jane; Chick, Helen

    2012-01-01

    This paper analyses the responses of 247 middle school students to items requiring the concept of average in three different contexts: a city's weather reported in maximum daily temperature, the number of children in a family, and the price of houses. The mixed but overall disappointing performance on the six items in the three contexts indicates…

  13. Your Average Nigga

    ERIC Educational Resources Information Center

    Young, Vershawn Ashanti

    2004-01-01

    "Your Average Nigga" contends that just as exaggerating the differences between black and white language leaves some black speakers, especially those from the ghetto, at an impasse, so exaggerating and reifying the differences between the races leaves blacks in the impossible position of either having to try to be white or forever struggling to…

  14. Determining average yarding distance.

    Treesearch

    Roger H. Twito; Charles N. Mann

    1979-01-01

    Emphasis on environmental and esthetic quality in timber harvesting has brought about increased use of complex boundaries of cutting units and a consequent need for a rapid and accurate method of determining the average yarding distance and area of these units. These values, needed for evaluation of road and landing locations in planning timber harvests, are easily and...

  15. Calculation of Glucose Dose for Intraperitoneal Glucose Tolerance Tests in Lean and Obese Mice.

    PubMed

    Jørgensen, Mikkel S; Tornqvist, Kristina S; Hvid, Henning

    2017-01-01

    Glucose tolerance tests are used frequently in nonclinical research with laboratory animals, for example during characterization of obese phenotypes. Despite published standard operating procedures for glucose tolerance tests in rodents, how glucose doses should be calculated when obese and lean animals are compared is not well documented. Typically the glucose dose is calculated as 2 g/kg body weight, regardless of body composition. With this approach, obese mice receive larger glucose doses than do lean animals, potentially leading to overestimation of glucose intolerance in obese animals. In this study, we performed intraperitoneal glucose tolerance tests in mice with diet-induced obesity and their lean controls, with glucose doses based on either the total body weight or the lean body mass of the animals. To determine glucose tolerance, we determined the blood glucose AUC during the glucose tolerance test. We found that the blood glucose AUC was increased significantly in obese mice compared with lean mice by 75% on average when glucose was dosed according to the lean body mass and by 87% when the glucose dose was calculated according to total body weight. Therefore, mice with diet-induced obesity were approximately equally glucose intolerant between the 2 dose-calculation protocols. However, we recommend calculating the glucose dose according to the lean body mass of the mice, because doing so eliminates the concern regarding overdosing of obese animals.

  16. Average is Over

    NASA Astrophysics Data System (ADS)

    Eliazar, Iddo

    2018-02-01

    The popular perception of statistical distributions is depicted by the iconic bell curve which comprises of a massive bulk of 'middle-class' values, and two thin tails - one of small left-wing values, and one of large right-wing values. The shape of the bell curve is unimodal, and its peak represents both the mode and the mean. Thomas Friedman, the famous New York Times columnist, recently asserted that we have entered a human era in which "Average is Over" . In this paper we present mathematical models for the phenomenon that Friedman highlighted. While the models are derived via different modeling approaches, they share a common foundation. Inherent tipping points cause the models to phase-shift from a 'normal' bell-shape statistical behavior to an 'anomalous' statistical behavior: the unimodal shape changes to an unbounded monotone shape, the mode vanishes, and the mean diverges. Hence: (i) there is an explosion of small values; (ii) large values become super-large; (iii) 'middle-class' values are wiped out, leaving an infinite rift between the small and the super large values; and (iv) "Average is Over" indeed.

  17. Dissociating Averageness and Attractiveness: Attractive Faces Are Not Always Average

    ERIC Educational Resources Information Center

    DeBruine, Lisa M.; Jones, Benedict C.; Unger, Layla; Little, Anthony C.; Feinberg, David R.

    2007-01-01

    Although the averageness hypothesis of facial attractiveness proposes that the attractiveness of faces is mostly a consequence of their averageness, 1 study has shown that caricaturing highly attractive faces makes them mathematically less average but more attractive. Here the authors systematically test the averageness hypothesis in 5 experiments…

  18. Alternatives to the Moving Average

    Treesearch

    Paul C. van Deusen

    2001-01-01

    There are many possible estimators that could be used with annual inventory data. The 5-year moving average has been selected as a default estimator to provide initial results for states having available annual inventory data. User objectives for these estimates are discussed. The characteristics of a moving average are outlined. It is shown that moving average...

  19. CSF glucose test

    MedlinePlus

    Glucose test - CSF; Cerebrospinal fluid glucose test ... The glucose level in the CSF should be 50 to 80 mg/100 mL (or greater than 2/3 ... Abnormal results include higher and lower glucose levels. Abnormal ... or fungus) Inflammation of the central nervous system Tumor

  20. Virtual Averaging Making Nonframe-Averaged Optical Coherence Tomography Images Comparable to Frame-Averaged Images.

    PubMed

    Chen, Chieh-Li; Ishikawa, Hiroshi; Wollstein, Gadi; Bilonick, Richard A; Kagemann, Larry; Schuman, Joel S

    2016-01-01

    Developing a novel image enhancement method so that nonframe-averaged optical coherence tomography (OCT) images become comparable to active eye-tracking frame-averaged OCT images. Twenty-one eyes of 21 healthy volunteers were scanned with noneye-tracking nonframe-averaged OCT device and active eye-tracking frame-averaged OCT device. Virtual averaging was applied to nonframe-averaged images with voxel resampling and adding amplitude deviation with 15-time repetitions. Signal-to-noise (SNR), contrast-to-noise ratios (CNR), and the distance between the end of visible nasal retinal nerve fiber layer (RNFL) and the foveola were assessed to evaluate the image enhancement effect and retinal layer visibility. Retinal thicknesses before and after processing were also measured. All virtual-averaged nonframe-averaged images showed notable improvement and clear resemblance to active eye-tracking frame-averaged images. Signal-to-noise and CNR were significantly improved (SNR: 30.5 vs. 47.6 dB, CNR: 4.4 vs. 6.4 dB, original versus processed, P < 0.0001, paired t -test). The distance between the end of visible nasal RNFL and the foveola was significantly different before (681.4 vs. 446.5 μm, Cirrus versus Spectralis, P < 0.0001) but not after processing (442.9 vs. 446.5 μm, P = 0.76). Sectoral macular total retinal and circumpapillary RNFL thicknesses showed systematic differences between Cirrus and Spectralis that became not significant after processing. The virtual averaging method successfully improved nontracking nonframe-averaged OCT image quality and made the images comparable to active eye-tracking frame-averaged OCT images. Virtual averaging may enable detailed retinal structure studies on images acquired using a mixture of nonframe-averaged and frame-averaged OCT devices without concerning about systematic differences in both qualitative and quantitative aspects.

  1. Virtual Averaging Making Nonframe-Averaged Optical Coherence Tomography Images Comparable to Frame-Averaged Images

    PubMed Central

    Chen, Chieh-Li; Ishikawa, Hiroshi; Wollstein, Gadi; Bilonick, Richard A.; Kagemann, Larry; Schuman, Joel S.

    2016-01-01

    Purpose Developing a novel image enhancement method so that nonframe-averaged optical coherence tomography (OCT) images become comparable to active eye-tracking frame-averaged OCT images. Methods Twenty-one eyes of 21 healthy volunteers were scanned with noneye-tracking nonframe-averaged OCT device and active eye-tracking frame-averaged OCT device. Virtual averaging was applied to nonframe-averaged images with voxel resampling and adding amplitude deviation with 15-time repetitions. Signal-to-noise (SNR), contrast-to-noise ratios (CNR), and the distance between the end of visible nasal retinal nerve fiber layer (RNFL) and the foveola were assessed to evaluate the image enhancement effect and retinal layer visibility. Retinal thicknesses before and after processing were also measured. Results All virtual-averaged nonframe-averaged images showed notable improvement and clear resemblance to active eye-tracking frame-averaged images. Signal-to-noise and CNR were significantly improved (SNR: 30.5 vs. 47.6 dB, CNR: 4.4 vs. 6.4 dB, original versus processed, P < 0.0001, paired t-test). The distance between the end of visible nasal RNFL and the foveola was significantly different before (681.4 vs. 446.5 μm, Cirrus versus Spectralis, P < 0.0001) but not after processing (442.9 vs. 446.5 μm, P = 0.76). Sectoral macular total retinal and circumpapillary RNFL thicknesses showed systematic differences between Cirrus and Spectralis that became not significant after processing. Conclusion The virtual averaging method successfully improved nontracking nonframe-averaged OCT image quality and made the images comparable to active eye-tracking frame-averaged OCT images. Translational Relevance Virtual averaging may enable detailed retinal structure studies on images acquired using a mixture of nonframe-averaged and frame-averaged OCT devices without concerning about systematic differences in both qualitative and quantitative aspects. PMID:26835180

  2. Averaging Models: Parameters Estimation with the R-Average Procedure

    ERIC Educational Resources Information Center

    Vidotto, G.; Massidda, D.; Noventa, S.

    2010-01-01

    The Functional Measurement approach, proposed within the theoretical framework of Information Integration Theory (Anderson, 1981, 1982), can be a useful multi-attribute analysis tool. Compared to the majority of statistical models, the averaging model can account for interaction effects without adding complexity. The R-Average method (Vidotto &…

  3. Association between blood glucose level derived using the oral glucose tolerance test and glycated hemoglobin level.

    PubMed

    Kim, Hyoung Joo; Kim, Young Geon; Park, Jin Soo; Ahn, Young Hwan; Ha, Kyoung Hwa; Kim, Dae Jung

    2016-05-01

    Glycated hemoglobin (HbA1c) is widely used as a marker of glycemic control. Translation of the HbA1c level to an average blood glucose level is useful because the latter figure is easily understood by patients. We studied the association between blood glucose levels revealed by the oral glucose tolerance test (OGTT) and HbA1c levels in a Korean population. A total of 1,000 subjects aged 30 to 64 years from the Cardiovascular and Metabolic Diseases Etiology Research Center cohort were included. Fasting glucose levels, post-load glucose levels at 30, 60, and 120 minutes into the OGTT, and HbA1c levels were measured. Linear regression of HbA1c with mean blood glucose levels derived using the OGTT revealed a significant correlation between these measures (predicted mean glucose [mg/dL] = 49.4 × HbA1c [%] - 149.6; R (2) = 0.54, p < 0.001). Our linear regression equation was quite different from that of the Alc-Derived Average Glucose (ADAG) study and Diabetes Control and Complications Trial (DCCT) cohort. Discrepancies between our results and those of the ADAG study and DCCT cohort may be attributable to differences in the test methods used and the extent of insulin secretion. More studies are needed to evaluate the association between HbA1c and self monitoring blood glucose levels.

  4. Lagrangian averaging with geodesic mean

    NASA Astrophysics Data System (ADS)

    Oliver, Marcel

    2017-11-01

    This paper revisits the derivation of the Lagrangian averaged Euler (LAE), or Euler-α equations in the light of an intrinsic definition of the averaged flow map as the geodesic mean on the volume-preserving diffeomorphism group. Under the additional assumption that first-order fluctuations are statistically isotropic and transported by the mean flow as a vector field, averaging of the kinetic energy Lagrangian of an ideal fluid yields the LAE Lagrangian. The derivation presented here assumes a Euclidean spatial domain without boundaries.

  5. Lagrangian averaging with geodesic mean.

    PubMed

    Oliver, Marcel

    2017-11-01

    This paper revisits the derivation of the Lagrangian averaged Euler (LAE), or Euler- α equations in the light of an intrinsic definition of the averaged flow map as the geodesic mean on the volume-preserving diffeomorphism group. Under the additional assumption that first-order fluctuations are statistically isotropic and transported by the mean flow as a vector field, averaging of the kinetic energy Lagrangian of an ideal fluid yields the LAE Lagrangian. The derivation presented here assumes a Euclidean spatial domain without boundaries.

  6. Glucose Levels and Risk of Frailty.

    PubMed

    Zaslavsky, Oleg; Walker, Rod L; Crane, Paul K; Gray, Shelly L; Larson, Eric B

    2016-09-01

    The association between glucose levels and incident frailty in older persons remains unclear. We examined the extent to which higher glucose levels in older adults with and without diabetes are related to risk of frailty. The data are from the Adult Changes in Thought study. We identified 1,848 individuals aged 65+ without dementia for whom glucose levels from laboratory measurements of glucose and glycated hemoglobin were available. Physical frailty using modified Fried's criteria was determined from biennial assessments. Frailty hazard was modeled as a function of time-varying measures of diabetes and average glucose levels using Cox regression. A total of 578 incident frailty cases (94 with diabetes, 484 without) occurred during a median follow-up of 4.8 years. The adjusted hazard ratio for frailty comparing those with and without diabetes was 1.52 (95% confidence interval = 1.19-1.94). In participants without diabetes, modeling suggested elevated frailty risk with greater average glucose levels (p = .019); for example, a glucose level of 110mg/dL compared with 100mg/dL yielded a hazard ratio of 1.32 (95% confidence interval = 1.09-1.59). In participants with diabetes, glucose levels less than 160mg/dL and greater than 180mg/dL were related to increased risk of frailty (p = .001). Higher glucose levels may be a risk factor for frailty in older adults without diabetes. The apparent U-shape association between glucose levels and frailty in people with diabetes is consistent with the literature on glycemia and mortality and deserves further examination. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  7. Turbine Engine Flowpath Averaging Techniques

    DTIC Science & Technology

    1980-10-01

    u~%x AEDC- TMR- 8 I-G 1 • R. P TURBINE ENGINE FLOWPATH AVERAGING TECHNIQUES T. W. Skiles ARO, Inc. October 1980 Final Report for Period...COVERED 00-01-1980 to 00-10-1980 4. TITLE AND SUBTITLE Turbine Engine Flowpath Averaging Techniques 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c...property for gas turbine engines were investigated. The investigation consisted of a literature review and review of turbine engine current flowpath

  8. High average power pockels cell

    DOEpatents

    Daly, Thomas P.

    1991-01-01

    A high average power pockels cell is disclosed which reduces the effect of thermally induced strains in high average power laser technology. The pockels cell includes an elongated, substantially rectangular crystalline structure formed from a KDP-type material to eliminate shear strains. The X- and Y-axes are oriented substantially perpendicular to the edges of the crystal cross-section and to the C-axis direction of propagation to eliminate shear strains.

  9. Glucose-6-phosphate dehydrogenase

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/003671.htm Glucose-6-phosphate dehydrogenase test To use the sharing features on this page, please enable JavaScript. Glucose-6-phosphate dehydrogenase (G6PD) is a protein that helps ...

  10. Glucose test (image)

    MedlinePlus

    ... person with diabetes constantly manages their blood's sugar (glucose) levels. After a blood sample is taken and tested, it is determined whether the glucose levels are low or high. Following your health ...

  11. Glucose kinetics in infants of diabetic mothers

    SciTech Connect

    Cowett, R.M.; Susa, J.B.; Giletti, B.

    1983-08-01

    Glucose kinetic studies were performed to define the glucose turnover rate with 78% enriched D-(U-13C) glucose by the prime constant infusion technique at less than or equal to 6 hours of age in nine infants of diabetic mothers (four insulin-dependent and five chemical diabetic patients) at term. Five normal infants were studied as control subjects. All infants received 0.9% saline intravenously during the study with the tracer. Fasting plasma glucose, insulin, and glucose13/12C ratios were measured during the steady state, and the glucose turnover rate was derived. The average plasma glucose concentration was similar during the steady state in themore » infants of the diabetic mothers and in the control infants, and the glucose turnover rate was not significantly different among the groups: 2.3 +/- 0.6 mg . kg-1 min-1 in infants of insulin-dependent diabetic patients; 2.4 +/- 0.4 mg . kg-1 min-1 in infants of chemical diabetic patients; and 3.2 +/- 0.3 mg . kg-1 min-1 in the control subjects. Good control of maternal diabetes evidenced by the normal maternal hemoglobin A1c and plasma glucose concentration at delivery and cord plasma glucose concentration resulted in glucose kinetic values in the infants of diabetic mothers that were indistinguishable from those of control subjects. The data further support the importance of good control of the diabetic state in the pregnant woman to minimize or prevent neonatal hypoglycemia.« less

  12. Determining GPS average performance metrics

    NASA Technical Reports Server (NTRS)

    Moore, G. V.

    1995-01-01

    Analytic and semi-analytic methods are used to show that users of the GPS constellation can expect performance variations based on their location. Specifically, performance is shown to be a function of both altitude and latitude. These results stem from the fact that the GPS constellation is itself non-uniform. For example, GPS satellites are over four times as likely to be directly over Tierra del Fuego than over Hawaii or Singapore. Inevitable performance variations due to user location occur for ground, sea, air and space GPS users. These performance variations can be studied in an average relative sense. A semi-analytic tool which symmetrically allocates GPS satellite latitude belt dwell times among longitude points is used to compute average performance metrics. These metrics include average number of GPS vehicles visible, relative average accuracies in the radial, intrack and crosstrack (or radial, north/south, east/west) directions, and relative average PDOP or GDOP. The tool can be quickly changed to incorporate various user antenna obscuration models and various GPS constellation designs. Among other applications, tool results can be used in studies to: predict locations and geometries of best/worst case performance, design GPS constellations, determine optimal user antenna location and understand performance trends among various users.

  13. Glucose screening tests during pregnancy

    MedlinePlus

    Oral glucose tolerance test - pregnancy; OGTT - pregnancy; Glucose challenge test - pregnancy; Gestational diabetes - glucose screening ... first step, you will have a glucose screening test: You DO NOT need to prepare or change ...

  14. Model averaging in linkage analysis.

    PubMed

    Matthysse, Steven

    2006-06-05

    Methods for genetic linkage analysis are traditionally divided into "model-dependent" and "model-independent," but there may be a useful place for an intermediate class, in which a broad range of possible models is considered as a parametric family. It is possible to average over model space with an empirical Bayes prior that weights models according to their goodness of fit to epidemiologic data, such as the frequency of the disease in the population and in first-degree relatives (and correlations with other traits in the pleiotropic case). For averaging over high-dimensional spaces, Markov chain Monte Carlo (MCMC) has great appeal, but it has a near-fatal flaw: it is not possible, in most cases, to provide rigorous sufficient conditions to permit the user safely to conclude that the chain has converged. A way of overcoming the convergence problem, if not of solving it, rests on a simple application of the principle of detailed balance. If the starting point of the chain has the equilibrium distribution, so will every subsequent point. The first point is chosen according to the target distribution by rejection sampling, and subsequent points by an MCMC process that has the target distribution as its equilibrium distribution. Model averaging with an empirical Bayes prior requires rapid estimation of likelihoods at many points in parameter space. Symbolic polynomials are constructed before the random walk over parameter space begins, to make the actual likelihood computations at each step of the random walk very fast. Power analysis in an illustrative case is described. (c) 2006 Wiley-Liss, Inc.

  15. PROFESSIONAL FLASH CONTINUOUS GLUCOSE MONITORING WITH AMBULATORY GLUCOSE PROFILE REPORTING TO SUPPLEMENT A1C: RATIONALE AND PRACTICAL IMPLEMENTATION.

    PubMed

    Hirsch, Irl B; Verderese, Carol A

    2017-11-01

    Recent consensus statements strongly advocate downloading and interpreting continuous glucose data for diabetes management in patients with type 1 or 2 diabetes. Supplementing periodic glycated hemoglobin (A1C) testing with intermittent continuous glucose monitoring (CGM) using a standardized report form known as the ambulatory glucose profile (AGP) is an evolving standard of care. The rationale for this approach and its implementation with a recently approved novel monitoring technology are explored. Search of the medical literature, professional guidelines, and real-world evidence guided this introduction of an integrative practice framework that uses AGP in conjunction with intermittent flash continuous glucose monitoring (FCGM) as a supplement to A1C testing. The combination of intermittent continuous glucose pattern analysis, standardized glucose metrics, and a readily interpretable data report has the potential to practically extend the recognized benefits of CGM to more patients and clarify the relationship between A1C and average glucose levels in individual cases. Novel FCGM technologies portend greater use of continuous forms of glucose monitoring and wider adoption of AGP report analysis. Additional formal and empirical evidence is needed to more fully characterize best practice. A1C = glycated hemoglobin; AGP = ambulatory glucose profile; CGM = continuous glucose monitoring; FCGM = flash continuous glucose monitoring; IQR = interquartile range; SMBG = self-monitoring of blood glucose.

  16. The glucose oxidase-peroxidase assay for glucose

    USDA-ARS?s Scientific Manuscript database

    The glucose oxidase-peroxidase assay for glucose has served as a very specific, sensitive, and repeatable assay for detection of glucose in biological samples. It has been used successfully for analysis of glucose in samples from blood and urine, to analysis of glucose released from starch or glycog...

  17. Glucose: detection and analysis

    USDA-ARS?s Scientific Manuscript database

    Glucose is an aldosic monosaccharide that is centrally entrenched in the processes of photosynthesis and respiration, serving as an energy reserve and metabolic fuel in most organisms. As both a monomer and as part of more complex structures such as polysaccharides and glucosides, glucose also pla...

  18. Blood glucose concentrations of arm and finger during dynamic glucose conditions.

    PubMed

    Szuts, Ete Z; Lock, J Paul; Malomo, Kenneth J; Anagnostopoulos, Althea

    2002-01-01

    We set out to determine the physiological difference between the capillary blood of the arm and finger with the greatest possible accuracy using the HemoCue B-glucose analyzer on subjects undergoing a meal tolerance test (MTT) or oral glucose tolerance test (OGTT). MTT study was performed on 50 subjects who drank a liquid meal (Ensure, 40 g of carbohydrates) and who were tested on the arm and finger every 30 min for up to 4 h. OGTT study was performed on 12 subjects who drank a 100-g glucose solution (Glucola) and were tested on the arm and finger every 15 min during the first hour and thereafter every 30 min for up to 3 h. Average percent glucose difference between arm and finger reached a maximal value about 1 h following glucose load, with arm glucose being about 5% lower than that of finger. At other times, average differences were less than this. At the greatest rate of glucose change (>2 mg/dL-min), mean percent bias was found to be about 6%. Despite these measurable differences, when arm results were plotted on the Clarke error grid against finger values, >97% of the data were within zone A (rest in zone B). Thus, physiological differences between arm and finger were clinically insignificant. Our studies with HemoCue confirmed the existence of measurable physiological glucose differences between arm and finger following a glucose challenge, but these differences were found to be clinically insignificant even in those subjects in whom they were measurable.

  19. The average Indian female nose.

    PubMed

    Patil, Surendra B; Kale, Satish M; Jaiswal, Sumeet; Khare, Nishant; Math, Mahantesh

    2011-12-01

    This study aimed to delineate the anthropometric measurements of the noses of young women of an Indian population and to compare them with the published ideals and average measurements for white women. This anthropometric survey included a volunteer sample of 100 young Indian women ages 18 to 35 years with Indian parents and no history of previous surgery or trauma to the nose. Standardized frontal, lateral, oblique, and basal photographs of the subjects' noses were taken, and 12 standard anthropometric measurements of the nose were determined. The results were compared with published standards for North American white women. In addition, nine nasal indices were calculated and compared with the standards for North American white women. The nose of Indian women differs significantly from the white nose. All the nasal measurements for the Indian women were found to be significantly different from those for North American white women. Seven of the nine nasal indices also differed significantly. Anthropometric analysis suggests differences between the Indian female nose and the North American white nose. Thus, a single aesthetic ideal is inadequate. Noses of Indian women are smaller and wider, with a less projected and rounded tip than the noses of white women. This study established the nasal anthropometric norms for nasal parameters, which will serve as a guide for cosmetic and reconstructive surgery in Indian women.

  20. Resonator graphene microfluidic antenna (RGMA) for blood glucose detection

    NASA Astrophysics Data System (ADS)

    Jizat, Noorlindawaty Md.; Mohamad, Su Natasha; Ishak, Muhammad Ikman

    2017-09-01

    Graphene is capable of highly sensitive analyte detection due to its nanoscale nature. Here we show a resonator graphene microfluidic antenna (RGMA) is used to detect the dielectric properties of aqueous glucose solution which represent the glucose level in blood. Simulation verified the high sensitivity of proposed RGMA made with aqueous glucose solutions at different concentrations. The RGMA yielded a sensor sensitivity of 0.1882GHz/mgml-1 as plotted from the slope of the linear fit from the result averages in S11 and S21 parameter, respectively. This results indicate that the proposed resonator antenna achieves high sensitivity and linear to the changes of glucose concentration.

  1. Continuous Glucose Monitoring

    PubMed Central

    van Beers, Cornelis A. J.; DeVries, J. Hans

    2016-01-01

    The necessity of strict glycemic control is unquestionable. However, hypoglycemia remains a major limiting factor in achieving satisfactory glucose control, and evidence is mounting to show that hypoglycemia is not benign. Over the past decade, evidence has consistently shown that real-time continuous glucose monitoring improves glycemic control in terms of lowering glycated hemoglobin levels. However, real-time continuous glucose monitoring has not met the expectations of the diabetes community with regard to hypoglycemia prevention. The earlier trials did not demonstrate any effect on either mild or severe hypoglycemia and the effect of real-time continuous glucose monitoring on nocturnal hypoglycemia was often not reported. However, trials specifically designed to reduce hypoglycemia in patients with a high hypoglycemia risk have demonstrated a reduction in hypoglycemia, suggesting that real-time continuous glucose monitoring can prevent hypoglycemia when it is specifically used for that purpose. Moreover, the newest generation of diabetes technology currently available commercially, namely sensor-augmented pump therapy with a (predictive) low glucose suspend feature, has provided more convincing evidence for hypoglycemia prevention. This article provides an overview of the hypoglycemia outcomes of randomized controlled trials that investigate the effect of real-time continuous glucose monitoring alone or sensor-augmented pump therapy with a (predictive) low glucose suspend feature. Furthermore, several possible explanations are provided why trials have not shown a reduction in severe hypoglycemia. In addition, existing evidence is presented of real-time continuous glucose monitoring in patients with impaired awareness of hypoglycemia who have the highest risk of severe hypoglycemia. PMID:27257169

  2. SELF BLOOD GLUCOSE MONITORING UNDERESTIMATES HYPERGLYCEMIA AND HYPOGLYCEMIA AS COMPARED TO CONTINUOUS GLUCOSE MONITORING IN TYPE 1 AND TYPE 2 DIABETES.

    PubMed

    Mangrola, Devna; Cox, Christine; Furman, Arianne S; Krishnan, Sridevi; Karakas, Sidika E

    2018-01-01

    When glucose records from self blood glucose monitoring (SBGM) do not reflect estimated average glucose from glycosylated hemoglobin (HgBA1) or when patients' clinical symptoms are not explained by their SBGM records, clinical management of diabetes becomes a challenge. Our objective was to determine the magnitude of differences in glucose values reported by SBGM versus those documented by continuous glucose monitoring (CGM). The CGM was conducted by a clinical diabetes educator (CDE)/registered nurse by the clinic protocol, using the Medtronic iPRO2 ™ system. Patients continued SBGM and managed their diabetes without any change. Data from 4 full days were obtained, and relevant clinical information was recorded. De-identified data sets were provided to the investigators. Data from 61 patients, 27 with type 1 diabetes (T1DM) and 34 with T2DM were analyzed. The lowest, highest, and average glucose recorded by SBGM were compared to the corresponding values from CGM. The lowest glucose values reported by SBGM were approximately 25 mg/dL higher in both T1DM ( P = .0232) and T2DM ( P = .0003). The highest glucose values by SBGM were approximately 30 mg/dL lower in T1DM ( P = .0005) and 55 mg/dL lower in T2DM ( P<.0001). HgBA1c correlated with the highest and average glucose by SBGM and CGM. The lowest glucose values were seen most frequently during sleep and before breakfast; the highest were seen during the evening and postprandially. SBGM accurately estimates the average glucose but underestimates glucose excursions. CGM uncovers glucose patterns that common SBGM patterns cannot. CDE = certified diabetes educator; CGM = continuous glucose monitoring; HgBA1c = glycosylated hemoglobin; MAD = mean absolute difference; SBGM = self blood glucose monitoring; T1DM = type 1 diabetes; T2DM = type 2 diabetes.

  3. Glucose urine test

    MedlinePlus

    Urine sugar test; Urine glucose test; Glucosuria test; Glycosuria test ... After you provide a urine sample, it is tested right away. The health care provider uses a dipstick made with a color-sensitive pad. The ...

  4. Continuous Glucose Monitoring

    MedlinePlus

    ... transmit- ter sends information about glucose levels via radio waves from the sensor to a pagerlike wireless ... 703–738–4929 Email: ndep@mail.nih.gov Internet: www.ndep.nih.gov American Diabetes Association 1701 ...

  5. Blood Glucose Monitoring Devices

    MedlinePlus

    ... of interferences ability to transmit data to a computer cost of the meter cost of the test ... Performance FDA expands indication for continuous glucose monitoring system, first to replace fingerstick testing for diabetes treatment ...

  6. Recombinant glucose uptake system

    DOEpatents

    Ingrahm, Lonnie O.; Snoep, Jacob L.; Arfman, Nico

    1997-01-01

    Recombinant organisms are disclosed that contain a pathway for glucose uptake other than the pathway normally utilized by the host cell. In particular, the host cell is one in which glucose transport into the cell normally is coupled to PEP production. This host cell is transformed so that it uses an alternative pathway for glucose transport that is not coupled to PEP production. In a preferred embodiment, the host cell is a bacterium other than Z. mobilis that has been transformed to contain the glf and glk genes of Z. mobilis. By uncoupling glucose transport into the cell from PEP utilization, more PEP is produced for synthesis of products of commercial importance from a given quantity of biomass supplied to the host cells.

  7. Alarm characterization for a continuous glucose monitor that replaces traditional blood glucose monitoring.

    PubMed

    McGarraugh, Geoffrey

    2010-01-01

    Continuous glucose monitoring (CGM) devices available in the United States are approved for use as adjuncts to self-monitoring of blood glucose (SMBG); all CGM alarms require SMBG confirmation before treatment. In this report, an analysis method is proposed to determine the CGM threshold alarm accuracy required to eliminate SMBG confirmation. The proposed method builds on the Clinical and Laboratory Standards Institute (CLSI) guideline for evaluating CGM threshold alarms using data from an in-clinic study of subjects with type 1 diabetes. The CLSI method proposes a maximum time limit of +/-30 minutes for the detection of hypo- and hyperglycemic events but does not include limits for glucose measurement accuracy. The International Standards Organization (ISO) standard for SMBG glucose measurement accuracy (ISO 15197) is +/-15 mg/dl for glucose <75 mg/dl and +/-20% for glucose > or = 75 mg/dl. This standard was combined with the CLSI method to more completely characterize the accuracy of CGM alarms. Incorporating the ISO 15197 accuracy margins, FreeStyle Navigator CGM system alarms detected 70 mg/dl hypoglycemia within 30 minutes at a rate of 70.3%, with a false alarm rate of 11.4%. The device detected high glucose in the range of 140-300 mg/dl within 30 minutes at an average rate of 99.2%, with a false alarm rate of 2.1%. Self-monitoring of blood glucose confirmation is necessary for detecting and treating hypoglycemia with the FreeStyle Navigator CGM system, but at high glucose levels, SMBG confirmation adds little incremental value to CGM alarms. 2010 Diabetes Technology Society.

  8. Weighted south-wide average pulpwood prices

    Treesearch

    James E. Granskog; Kevin D. Growther

    1991-01-01

    Weighted average prices provide a more accurate representation of regional pulpwood price trends when production volumes valy widely by state. Unweighted South-wide average delivered prices for pulpwood, as reported by Timber Mart-South, were compared to average annual prices weighted by each state's pulpwood production from 1977 to 1986. Weighted average prices...

  9. Effects of indigestible dextrin on glucose tolerance in rats.

    PubMed

    Wakabayashi, S; Kishimoto, Y; Matsuoka, A

    1995-03-01

    A recently developed indigestible dextrin (IDex) was studied for its effects on glucose tolerance in male Sprague-Dawley rats. IDex is a low viscosity, water-soluble dietary fibre obtained by heating and enzyme treatment of potato starch. It has an average molecular weight of 1600. An oral glucose tolerance test was conducted with 8-week-old rats to evaluate the effects of IDex on the increase in plasma glucose and insulin levels after a single administration of various sugars (1.5 g/kg body weight). The increase in both plasma glucose and insulin levels following sucrose, maltose and maltodextrin loading was significantly reduced by IDex (0.15 g/kg body weight). This effect was not noted following glucose, high fructose syrup and lactose loading. To evaluate the effects of continual IDex ingestion on glucose tolerance, 5-week-old rats were kept for 8 weeks on a stock diet, a high sucrose diet or an IDex-supplemented high sucrose diet. An oral glucose (1.5 g/kg body weight) tolerance test was conducted in week 8. Increases in both plasma glucose and insulin levels following glucose loading were higher in the rats given a high sucrose diet than in the rats fed a stock diet. However, when IDex was included in the high sucrose diet, the impairment of glucose tolerance was alleviated. Moreover, IDex feeding also significantly reduced accumulation of body fat, regardless of changes in body weight. These findings suggest that IDex not only improves glucose tolerance following sucrose, maltose and maltodextrin loading but also stops progressive decrease in glucose tolerance by preventing a high sucrose diet from causing obesity.

  10. Evaluation of a Novel Glucose Area Under the Curve (AUC) Monitoring System: Comparison with the AUC by Continuous Glucose Monitoring.

    PubMed

    Ugi, Satoshi; Maegawa, Hiroshi; Morino, Katsutaro; Nishio, Yoshihiko; Sato, Toshiyuki; Okada, Seiki; Kikkawa, Yasuo; Watanabe, Toshihiro; Nakajima, Hiromu; Kashiwagi, Atsunori

    2016-08-01

    Management of postprandial hyperglycemia is a key aspect in diabetes treatment. We developed a novel system to measure glucose area under the curve (AUC) using minimally invasive interstitial fluid extraction technology (MIET) for simple monitoring of postprandial glucose excursions. In this study, we evaluated the relationship between our system and continuous glucose monitoring (CGM) by comparing glucose AUC obtained using MIET with that obtained using CGM for a long duration. Twenty diabetic inpatients wearing a CGM system were enrolled. For MIET measurement, a plastic microneedle array was applied to the skin as pretreatment, and hydrogels were placed on the pretreated area to collect interstitial fluid. Hydrogels were replaced every 2 or 4 hours and AUC was predicted on the basis of glucose and sodium ion levels. AUC predicted by MIET correlated well with that measured by CGM (r=0.93). Good performances of both consecutive 2- and 4-hour measurements were observed (measurement error: 11.7%±10.2% for 2 hours and 11.1%±7.9% for 4 hours), indicating the possibility of repetitive measurements up to 8 hours. The influence of neither glucose fluctuation nor average glucose level over the measurement accuracy was observed through 8 hours. Our system showed good relationship with AUC values from CGM up to 8 hours, indicating that single pretreatment can cover a large portion of glucose excursion in a day. These results indicated possibility of our system to contribute to convenient monitoring of glucose excursions for a long duration.

  11. Redundancy in Glucose Sensing

    PubMed Central

    Sharifi, Amin; Varsavsky, Andrea; Ulloa, Johanna; Horsburgh, Jodie C.; McAuley, Sybil A.; Krishnamurthy, Balasubramanian; Jenkins, Alicia J.; Colman, Peter G.; Ward, Glenn M.; MacIsaac, Richard J.; Shah, Rajiv; O’Neal, David N.

    2015-01-01

    Background: Current electrochemical glucose sensors use a single electrode. Multiple electrodes (redundancy) may enhance sensor performance. We evaluated an electrochemical redundant sensor (ERS) incorporating two working electrodes (WE1 and WE2) onto a single subcutaneous insertion platform with a processing algorithm providing a single real-time continuous glucose measure. Methods: Twenty-three adults with type 1 diabetes each wore two ERSs concurrently for 168 hours. Post-insertion a frequent sampling test (FST) was performed with ERS benchmarked against a glucose meter (Bayer Contour Link). Day 4 and 7 FSTs were performed with a standard meal and venous blood collected for reference glucose measurements (YSI and meter). Between visits, ERS was worn with capillary blood glucose testing ≥8 times/day. Sensor glucose data were processed prospectively. Results: Mean absolute relative deviation (MARD) for ERS day 1-7 (3,297 paired points with glucose meter) was (mean [SD]) 10.1 [11.5]% versus 11.4 [11.9]% for WE1 and 12.0 [11.9]% for WE2; P < .0001. ERS Clarke A and A+B were 90.2% and 99.8%, respectively. ERS day 4 plus day 7 MARD (1,237 pairs with YSI) was 9.4 [9.5]% versus 9.6 [9.7]% for WE1 and 9.9 [9.7]% for WE2; P = ns. ERS day 1-7 precision absolute relative deviation (PARD) was 9.9 [3.6]% versus 11.5 [6.2]% for WE1 and 10.1 [4.4]% for WE2; P = ns. ERS sensor display time was 97.8 [6.0]% versus 91.0 [22.3]% for WE1 and 94.1 [14.3]% for WE2; P < .05. Conclusions: Electrochemical redundancy enhances glucose sensor accuracy and display time compared with each individual sensing element alone. ERS performance compares favorably with ‘best-in-class’ of non-redundant sensors. PMID:26499476

  12. RHIC BPM system average orbit calculations

    SciTech Connect

    Michnoff,R.; Cerniglia, P.; Degen, C.

    2009-05-04

    RHIC beam position monitor (BPM) system average orbit was originally calculated by averaging positions of 10000 consecutive turns for a single selected bunch. Known perturbations in RHIC particle trajectories, with multiple frequencies around 10 Hz, contribute to observed average orbit fluctuations. In 2006, the number of turns for average orbit calculations was made programmable; this was used to explore averaging over single periods near 10 Hz. Although this has provided an average orbit signal quality improvement, an average over many periods would further improve the accuracy of the measured closed orbit. A new continuous average orbit calculation was developed justmore » prior to the 2009 RHIC run and was made operational in March 2009. This paper discusses the new algorithm and performance with beam.« less

  13. 40 CFR 76.11 - Emissions averaging.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.11 Emissions averaging. (a) General... averaging plan is in compliance with the Acid Rain emission limitation for NOX under the plan only if the...

  14. 40 CFR 76.11 - Emissions averaging.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.11 Emissions averaging. (a) General... averaging plan is in compliance with the Acid Rain emission limitation for NOX under the plan only if the...

  15. 40 CFR 91.1304 - Averaging.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Averaging. (a) A manufacturer may use averaging across engine families to demonstrate a zero or positive... credits obtained through trading. (b) Beginning in model year 2004, credits used to demonstrate a zero or...

  16. 40 CFR 91.1304 - Averaging.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Averaging. (a) A manufacturer may use averaging across engine families to demonstrate a zero or positive... credits obtained through trading. (b) Beginning in model year 2004, credits used to demonstrate a zero or...

  17. 40 CFR 91.1304 - Averaging.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Averaging. (a) A manufacturer may use averaging across engine families to demonstrate a zero or positive... credits obtained through trading. (b) Beginning in model year 2004, credits used to demonstrate a zero or...

  18. 40 CFR 91.1304 - Averaging.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Averaging. (a) A manufacturer may use averaging across engine families to demonstrate a zero or positive... credits obtained through trading. (b) Beginning in model year 2004, credits used to demonstrate a zero or...

  19. 40 CFR 91.1304 - Averaging.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Averaging. (a) A manufacturer may use averaging across engine families to demonstrate a zero or positive... credits obtained through trading. (b) Beginning in model year 2004, credits used to demonstrate a zero or...

  20. 40 CFR 89.204 - Averaging.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... are defined as follows: (1) Eligible engines rated at or above 19 kW, other than marine diesel engines, constitute an averaging set. (2) Eligible engines rated under 19 kW, other than marine diesel engines, constitute an averaging set. (3) Marine diesel engines rated at or above 19 kW constitute an averaging set...

  1. 40 CFR 89.204 - Averaging.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... are defined as follows: (1) Eligible engines rated at or above 19 kW, other than marine diesel engines, constitute an averaging set. (2) Eligible engines rated under 19 kW, other than marine diesel engines, constitute an averaging set. (3) Marine diesel engines rated at or above 19 kW constitute an averaging set...

  2. 40 CFR 89.204 - Averaging.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... are defined as follows: (1) Eligible engines rated at or above 19 kW, other than marine diesel engines, constitute an averaging set. (2) Eligible engines rated under 19 kW, other than marine diesel engines, constitute an averaging set. (3) Marine diesel engines rated at or above 19 kW constitute an averaging set...

  3. 40 CFR 89.204 - Averaging.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... are defined as follows: (1) Eligible engines rated at or above 19 kW, other than marine diesel engines, constitute an averaging set. (2) Eligible engines rated under 19 kW, other than marine diesel engines, constitute an averaging set. (3) Marine diesel engines rated at or above 19 kW constitute an averaging set...

  4. Averaging and Adding in Children's Worth Judgements

    ERIC Educational Resources Information Center

    Schlottmann, Anne; Harman, Rachel M.; Paine, Julie

    2012-01-01

    Under the normative Expected Value (EV) model, multiple outcomes are additive, but in everyday worth judgement intuitive averaging prevails. Young children also use averaging in EV judgements, leading to a disordinal, crossover violation of utility when children average the part worths of simple gambles involving independent events (Schlottmann,…

  5. Continuous Glucose Monitoring

    MedlinePlus

    ... costs will be covered. What is an artificial pancreas? A CGM is one part of the “artificial pancreas” systems that are beginning to reach people with ... has played an important role in developing artificial pancreas technology. An artificial pancreas replaces manual blood glucose ...

  6. Glucose Tolerance and Hyperkinesis.

    ERIC Educational Resources Information Center

    Langseth, Lillian; Dowd, Judith

    Examined were medical records of 265 hyperkinetic children (7-9 years old). Clinical blood chemistries, hematology, and 5-hour glucose tolerance test (GTT) results indicated that hematocrit levels were low in 27% of the Ss, eosinophil levels were abnormally high in 86% of the Ss, and GTT results were abnormal in a maority of Ss. (CL)

  7. Ketosis proportionately spares glucose utilization in brain

    PubMed Central

    Zhang, Yifan; Kuang, Youzhi; Xu, Kui; Harris, Donald; Lee, Zhenghong; LaManna, Joseph; Puchowicz, Michelle A

    2013-01-01

    The brain is dependent on glucose as a primary energy substrate, but is capable of utilizing ketones such as β-hydroxybutyrate and acetoacetate, as occurs with fasting, starvation, or chronic feeding of a ketogenic diet. The relationship between changes in cerebral metabolic rates of glucose (CMRglc) and degree or duration of ketosis remains uncertain. To investigate if CMRglc decreases with chronic ketosis, 2-[18F]fluoro-2-deoxy-D-glucose in combination with positron emission tomography, was applied in anesthetized young adult rats fed 3 weeks of either standard or ketogenic diets. Cerebral metabolic rates of glucose (μmol/min per 100 g) was determined in the cerebral cortex and cerebellum using Gjedde–Patlak analysis. The average CMRglc significantly decreased in the cerebral cortex (23.0±4.9 versus 32.9±4.7) and cerebellum (29.3±8.6 versus 41.2±6.4) with increased plasma ketone bodies in the ketotic rats compared with standard diet group. The reduction of CMRglc in both brain regions correlates linearly by ∼9% for each 1 mmol/L increase of total plasma ketone bodies (0.3 to 6.3 mmol/L). Together with our meta-analysis, these data revealed that the degree and duration of ketosis has a major role in determining the corresponding change in CMRglc with ketosis. PMID:23736643

  8. Ketosis proportionately spares glucose utilization in brain.

    PubMed

    Zhang, Yifan; Kuang, Youzhi; Xu, Kui; Harris, Donald; Lee, Zhenghong; LaManna, Joseph; Puchowicz, Michelle A

    2013-08-01

    The brain is dependent on glucose as a primary energy substrate, but is capable of utilizing ketones such as β-hydroxybutyrate and acetoacetate, as occurs with fasting, starvation, or chronic feeding of a ketogenic diet. The relationship between changes in cerebral metabolic rates of glucose (CMRglc) and degree or duration of ketosis remains uncertain. To investigate if CMRglc decreases with chronic ketosis, 2-[(18)F]fluoro-2-deoxy-D-glucose in combination with positron emission tomography, was applied in anesthetized young adult rats fed 3 weeks of either standard or ketogenic diets. Cerebral metabolic rates of glucose (μmol/min per 100 g) was determined in the cerebral cortex and cerebellum using Gjedde-Patlak analysis. The average CMRglc significantly decreased in the cerebral cortex (23.0±4.9 versus 32.9±4.7) and cerebellum (29.3±8.6 versus 41.2±6.4) with increased plasma ketone bodies in the ketotic rats compared with standard diet group. The reduction of CMRglc in both brain regions correlates linearly by ∼9% for each 1 mmol/L increase of total plasma ketone bodies (0.3 to 6.3 mmol/L). Together with our meta-analysis, these data revealed that the degree and duration of ketosis has a major role in determining the corresponding change in CMRglc with ketosis.

  9. Dietary fructose and glucose differentially affect lipid and glucose homeostasis.

    PubMed

    Schaefer, Ernst J; Gleason, Joi A; Dansinger, Michael L

    2009-06-01

    Absorbed glucose and fructose differ in that glucose largely escapes first-pass removal by the liver, whereas fructose does not, resulting in different metabolic effects of these 2 monosaccharides. In short-term controlled feeding studies, dietary fructose significantly increases postprandial triglyceride (TG) levels and has little effect on serum glucose concentrations, whereas dietary glucose has the opposite effects. When dietary glucose and fructose have been directly compared at approximately 20-25% of energy over a 4- to 6-wk period, dietary fructose caused significant increases in fasting TG and LDL cholesterol concentrations, whereas dietary glucose did not, but dietary glucose did increase serum glucose and insulin concentrations in the postprandial state whereas dietary fructose did not. When fructose at 30-60 g ( approximately 4-12% of energy) was added to the diet in the free-living state, there were no significant effects on lipid or glucose biomarkers. Sucrose and high-fructose corn syrup (HFCS) contain approximately equal amounts of fructose and glucose and no metabolic differences between them have been noted. Controlled feeding studies at more physiologic dietary intakes of fructose and glucose need to be conducted. In our view, to decrease the current high prevalence of obesity, dyslipidemia, insulin resistance, and diabetes, the focus should be on restricting the intake of excess energy, sucrose, HFCS, and animal and trans fats and increasing exercise and the intake of vegetables, vegetable oils, fish, fruit, whole grains, and fiber.

  10. Liver glucose metabolism in humans

    PubMed Central

    Adeva-Andany, María M.; Pérez-Felpete, Noemi; Fernández-Fernández, Carlos; Donapetry-García, Cristóbal; Pazos-García, Cristina

    2016-01-01

    Information about normal hepatic glucose metabolism may help to understand pathogenic mechanisms underlying obesity and diabetes mellitus. In addition, liver glucose metabolism is involved in glycosylation reactions and connected with fatty acid metabolism. The liver receives dietary carbohydrates directly from the intestine via the portal vein. Glucokinase phosphorylates glucose to glucose 6-phosphate inside the hepatocyte, ensuring that an adequate flow of glucose enters the cell to be metabolized. Glucose 6-phosphate may proceed to several metabolic pathways. During the post-prandial period, most glucose 6-phosphate is used to synthesize glycogen via the formation of glucose 1-phosphate and UDP–glucose. Minor amounts of UDP–glucose are used to form UDP–glucuronate and UDP–galactose, which are donors of monosaccharide units used in glycosylation. A second pathway of glucose 6-phosphate metabolism is the formation of fructose 6-phosphate, which may either start the hexosamine pathway to produce UDP-N-acetylglucosamine or follow the glycolytic pathway to generate pyruvate and then acetyl-CoA. Acetyl-CoA may enter the tricarboxylic acid (TCA) cycle to be oxidized or may be exported to the cytosol to synthesize fatty acids, when excess glucose is present within the hepatocyte. Finally, glucose 6-phosphate may produce NADPH and ribose 5-phosphate through the pentose phosphate pathway. Glucose metabolism supplies intermediates for glycosylation, a post-translational modification of proteins and lipids that modulates their activity. Congenital deficiency of phosphoglucomutase (PGM)-1 and PGM-3 is associated with impaired glycosylation. In addition to metabolize carbohydrates, the liver produces glucose to be used by other tissues, from glycogen breakdown or from de novo synthesis using primarily lactate and alanine (gluconeogenesis). PMID:27707936

  11. Cosmological ensemble and directional averages of observables

    SciTech Connect

    Bonvin, Camille; Clarkson, Chris; Durrer, Ruth

    We show that at second order, ensemble averages of observables and directional averages do not commute due to gravitational lensing—observing the same thing in many directions over the sky is not the same as taking an ensemble average. In principle this non-commutativity is significant for a variety of quantities that we often use as observables and can lead to a bias in parameter estimation. We derive the relation between the ensemble average and the directional average of an observable, at second order in perturbation theory. We discuss the relevance of these two types of averages for making predictions of cosmologicalmore » observables, focusing on observables related to distances and magnitudes. In particular, we show that the ensemble average of the distance in a given observed direction is increased by gravitational lensing, whereas the directional average of the distance is decreased. For a generic observable, there exists a particular function of the observable that is not affected by second-order lensing perturbations. We also show that standard areas have an advantage over standard rulers, and we discuss the subtleties involved in averaging in the case of supernova observations.« less

  12. Glucose Counterregulatory Responses to Hypoglycemia

    PubMed Central

    Sprague, Jennifer E.; Arbeláez, Ana María

    2013-01-01

    The brain relies almost exclusively on glucose for fuel. Therefore, adequate uptake of glucose from the plasma is key for normal brain function and survival. Despite wide variations in glucose flux (i.e. fed state, fasting state, etc), blood glucose is maintained in a very narrow range. This is accomplished by a series of hormonal and physiologic responses. As a result, hypoglycemia is a rare occurrence in normal individuals. However, glucose counterregulatory responses are altered in patients with diabetes treated with insulin especially after repeated hypoglycemia or antecedent exercise. PMID:22783644

  13. Improving consensus structure by eliminating averaging artifacts

    PubMed Central

    KC, Dukka B

    2009-01-01

    Background Common structural biology methods (i.e., NMR and molecular dynamics) often produce ensembles of molecular structures. Consequently, averaging of 3D coordinates of molecular structures (proteins and RNA) is a frequent approach to obtain a consensus structure that is representative of the ensemble. However, when the structures are averaged, artifacts can result in unrealistic local geometries, including unphysical bond lengths and angles. Results Herein, we describe a method to derive representative structures while limiting the number of artifacts. Our approach is based on a Monte Carlo simulation technique that drives a starting structure (an extended or a 'close-by' structure) towards the 'averaged structure' using a harmonic pseudo energy function. To assess the performance of the algorithm, we applied our approach to Cα models of 1364 proteins generated by the TASSER structure prediction algorithm. The average RMSD of the refined model from the native structure for the set becomes worse by a mere 0.08 Å compared to the average RMSD of the averaged structures from the native structure (3.28 Å for refined structures and 3.36 A for the averaged structures). However, the percentage of atoms involved in clashes is greatly reduced (from 63% to 1%); in fact, the majority of the refined proteins had zero clashes. Moreover, a small number (38) of refined structures resulted in lower RMSD to the native protein versus the averaged structure. Finally, compared to PULCHRA [1], our approach produces representative structure of similar RMSD quality, but with much fewer clashes. Conclusion The benchmarking results demonstrate that our approach for removing averaging artifacts can be very beneficial for the structural biology community. Furthermore, the same approach can be applied to almost any problem where averaging of 3D coordinates is performed. Namely, structure averaging is also commonly performed in RNA secondary prediction [2], which could also benefit

  14. Gliotransmission and Brain Glucose Sensing

    PubMed Central

    Lanfray, Damien; Arthaud, Sébastien; Ouellet, Johanne; Compère, Vincent; Do Rego, Jean-Luc; Leprince, Jérôme; Lefranc, Benjamin; Castel, Hélène; Bouchard, Cynthia; Monge-Roffarello, Boris; Richard, Denis; Pelletier, Georges; Vaudry, Hubert; Tonon, Marie-Christine; Morin, Fabrice

    2013-01-01

    Hypothalamic glucose sensing is involved in the control of feeding behavior and peripheral glucose homeostasis, and glial cells are suggested to play an important role in this process. Diazepam-binding inhibitor (DBI) and its processing product the octadecaneuropeptide (ODN), collectively named endozepines, are secreted by astroglia, and ODN is a potent anorexigenic factor. Therefore, we investigated the involvement of endozepines in brain glucose sensing. First, we showed that intracerebroventricular administration of glucose in rats increases DBI expression in hypothalamic glial-like tanycytes. We then demonstrated that glucose stimulates endozepine secretion from hypothalamic explants. Feeding experiments indicate that the anorexigenic effect of central administration of glucose was blunted by coinjection of an ODN antagonist. Conversely, the hyperphagic response elicited by central glucoprivation was suppressed by an ODN agonist. The anorexigenic effects of centrally injected glucose or ODN agonist were suppressed by blockade of the melanocortin-3/4 receptors, suggesting that glucose sensing involves endozepinergic control of the melanocortin pathway. Finally, we found that brain endozepines modulate blood glucose levels, suggesting their involvement in a feedback loop controlling whole-body glucose homeostasis. Collectively, these data indicate that endozepines are a critical relay in brain glucose sensing and potentially new targets in treatment of metabolic disorders. PMID:23160530

  15. 40 CFR 86.449 - Averaging provisions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Later New Motorcycles, General Provisions § 86.449 Averaging provisions. (a) This section describes how... credits may not be banked for use in later model years, except as specified in paragraph (j) of this... average emission levels are at or below the applicable standards in § 86.410-2006. (2) Compliance with the...

  16. Determinants of College Grade Point Averages

    ERIC Educational Resources Information Center

    Bailey, Paul Dean

    2012-01-01

    Chapter 2: The Role of Class Difficulty in College Grade Point Averages. Grade Point Averages (GPAs) are widely used as a measure of college students' ability. Low GPAs can remove a students from eligibility for scholarships, and even continued enrollment at a university. However, GPAs are determined not only by student ability but also by the…

  17. 40 CFR 63.846 - Emission averaging.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... averaging. (a) General. The owner or operator of an existing potline or anode bake furnace in a State that... by total aluminum production. (c) Anode bake furnaces. The owner or operator may average TF emissions from anode bake furnaces and demonstrate compliance with the limits in Table 3 of this subpart using...

  18. 40 CFR 63.846 - Emission averaging.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... averaging. (a) General. The owner or operator of an existing potline or anode bake furnace in a State that... by total aluminum production. (c) Anode bake furnaces. The owner or operator may average TF emissions from anode bake furnaces and demonstrate compliance with the limits in Table 3 of this subpart using...

  19. 40 CFR 63.846 - Emission averaging.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... averaging. (a) General. The owner or operator of an existing potline or anode bake furnace in a State that... by total aluminum production. (c) Anode bake furnaces. The owner or operator may average TF emissions from anode bake furnaces and demonstrate compliance with the limits in Table 3 of this subpart using...

  20. 40 CFR 63.846 - Emission averaging.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... averaging. (a) General. The owner or operator of an existing potline or anode bake furnace in a State that... by total aluminum production. (c) Anode bake furnaces. The owner or operator may average TF emissions from anode bake furnaces and demonstrate compliance with the limits in Table 3 of this subpart using...

  1. 40 CFR 63.846 - Emission averaging.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... averaging. (a) General. The owner or operator of an existing potline or anode bake furnace in a State that... by total aluminum production. (c) Anode bake furnaces. The owner or operator may average TF emissions from anode bake furnaces and demonstrate compliance with the limits in Table 3 of this subpart using...

  2. 40 CFR 89.204 - Averaging.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Provisions § 89.204 Averaging. (a) Requirements for Tier 1 engines rated at or above 37 kW. A manufacturer... credits obtained through trading. (b) Requirements for Tier 2 and later engines rated at or above 37 kW and Tier 1 and later engines rated under 37 kW. A manufacturer may use averaging to offset an emission...

  3. Continuous glucose monitoring and its relationship to hemoglobin A1c and oral glucose tolerance testing in obese and prediabetic youth.

    PubMed

    Chan, Christine L; Pyle, Laura; Newnes, Lindsey; Nadeau, Kristen J; Zeitler, Philip S; Kelsey, Megan M

    2015-03-01

    The optimal screening test for diabetes and prediabetes in obese youth is controversial. We examined whether glycosylated hemoglobin (HbA1c) or the oral glucose tolerance test (OGTT) is a better predictor of free-living glycemia as measured by continuous glucose monitoring (CGM). This was a cross-sectional study of youth 10-18 years old, body mass index (BMI) 85th percentile or greater, with diabetes risk factors. Participants (n = 118) with BMI 85th percentile or greater, not on medications for glucose management, were recruited from primary care and pediatric endocrinology clinics around Denver, Colorado. HbA1c, fasting plasma glucose, and 2-hour glucose were collected and all participants wore a blinded CGM for 72 hours. CGM outcomes were determined and descriptive statistics calculated. Performance characteristics at current American Diabetes Association cutpoints were compared with CGM outcomes. CGM data were successfully collected on 98 obese youth. Those with prediabetes had significantly higher average glucose, area under the curve (AUC), peak glucose, and time greater than 120 and greater than 140 mg/dL (P < .01) on CGM than youth with normal HbA1c or OGTT. HbA1c had a greater magnitude of correlation to CGM average glucose, AUC, and minimum glucose; 2-hour glucose had a greater magnitude of correlation to CGM SD, peak glucose, and time greater than 140 and greater than 200 mg/dL. However, there were no overall differences in the strength comparisons between 2-hour glucose and HbA1c correlations to CGM outcomes. In obese youth, HbA1c and 2-hour glucose performed equally well at predicting free-living glycemia on CGM, suggesting that both are valid tests for dysglycemia screening.

  4. Light propagation in the averaged universe

    SciTech Connect

    Bagheri, Samae; Schwarz, Dominik J., E-mail: s_bagheri@physik.uni-bielefeld.de, E-mail: dschwarz@physik.uni-bielefeld.de

    Cosmic structures determine how light propagates through the Universe and consequently must be taken into account in the interpretation of observations. In the standard cosmological model at the largest scales, such structures are either ignored or treated as small perturbations to an isotropic and homogeneous Universe. This isotropic and homogeneous model is commonly assumed to emerge from some averaging process at the largest scales. We assume that there exists an averaging procedure that preserves the causal structure of space-time. Based on that assumption, we study the effects of averaging the geometry of space-time and derive an averaged version of themore » null geodesic equation of motion. For the averaged geometry we then assume a flat Friedmann-Lemaître (FL) model and find that light propagation in this averaged FL model is not given by null geodesics of that model, but rather by a modified light propagation equation that contains an effective Hubble expansion rate, which differs from the Hubble rate of the averaged space-time.« less

  5. A photonic crystal fiber glucose sensor filled with silver nanowires

    NASA Astrophysics Data System (ADS)

    Yang, X. C.; Lu, Y.; Wang, M. T.; Yao, J. Q.

    2016-01-01

    We report a photonic crystal fiber glucose sensor filled with silver nanowires in this paper. The proposed sensor is both analyzed by COMSOL multiphysics software and demonstrated by experiments. The extremely high average spectral sensitivity 19009.17 nm/RIU for experimental measurement is obtained, equivalent to 44.25 mg/dL of glucose in water, which is lower than 70 mg/dL for efficient detection of hypoglycemia episodes. The silver nanowires diameter which may affect the sensor's spectral sensitivity is also discussed and an optimal range of silver nanowires diameter 90-120 nm is obtained. We expect that the sensor can provide an effective platform for glucose sensing and potentially leading to a further development towards minimal-invasive glucose measurement.

  6. 40 CFR 76.11 - Emissions averaging.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.11 Emissions averaging. (a) General... compliance with the Acid Rain emission limitation for NOX under the plan only if the following requirements...

  7. 40 CFR 76.11 - Emissions averaging.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.11 Emissions averaging. (a) General... compliance with the Acid Rain emission limitation for NOX under the plan only if the following requirements...

  8. 40 CFR 76.11 - Emissions averaging.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.11 Emissions averaging. (a) General... compliance with the Acid Rain emission limitation for NOX under the plan only if the following requirements...

  9. Manufacturer's Policies Concerning Average Fuel Economy Standards

    DOT National Transportation Integrated Search

    1979-01-01

    The National Highway Traffic Safety Administration (NHTSA) has been given the responsibility for implementing the average fuel economy standards for passenger automobiles mandated by the Energy Policy and Conservation Act (P.L. 94-163). The standards...

  10. Schedule of average annual equipment ownership expense

    DOT National Transportation Integrated Search

    2003-03-06

    The "Schedule of Average Annual Equipment Ownership Expense" is designed for use on Force Account bills of Contractors performing work for the Illinois Department of Transportation and local government agencies who choose to adopt these rates. This s...

  11. Optimal Budget Allocation for Sample Average Approximation

    DTIC Science & Technology

    2011-06-01

    an optimization algorithm applied to the sample average problem. We examine the convergence rate of the estimator as the computing budget tends to...regime for the optimization algorithm . 1 Introduction Sample average approximation (SAA) is a frequently used approach to solving stochastic programs...appealing due to its simplicity and the fact that a large number of standard optimization algorithms are often available to optimize the resulting sample

  12. Applications of high average power nonlinear optics

    SciTech Connect

    Velsko, S.P.; Krupke, W.F.

    1996-02-05

    Nonlinear optical frequency convertors (harmonic generators and optical parametric oscillators are reviewed with an emphasis on high average power performance and limitations. NLO materials issues and NLO device designs are discussed in reference to several emerging scientific, military and industrial commercial applications requiring {approx} 100 watt average power level in the visible and infrared spectral regions. Research efforts required to enable practical {approx} 100 watt class NLO based laser systems are identified.

  13. Monthly average polar sea-ice concentration

    USGS Publications Warehouse

    Schweitzer, Peter N.

    1995-01-01

    The data contained in this CD-ROM depict monthly averages of sea-ice concentration in the modern polar oceans. These averages were derived from the Scanning Multichannel Microwave Radiometer (SMMR) and Special Sensor Microwave/Imager (SSM/I) instruments aboard satellites of the U.S. Air Force Defense Meteorological Satellite Program from 1978 through 1992. The data are provided as 8-bit images using the Hierarchical Data Format (HDF) developed by the National Center for Supercomputing Applications.

  14. Heuristic approach to capillary pressures averaging

    SciTech Connect

    Coca, B.P.

    1980-10-01

    Several methods are available to average capillary pressure curves. Among these are the J-curve and regression equations of the wetting-fluid saturation in porosity and permeability (capillary pressure held constant). While the regression equation seem completely empiric, the J-curve method seems to be theoretically sound due to its expression based on a relation between the average capillary radius and the permeability-porosity ratio. An analysis is given of each of these methods.

  15. Instrument to average 100 data sets

    NASA Technical Reports Server (NTRS)

    Tuma, G. B.; Birchenough, A. G.; Rice, W. J.

    1977-01-01

    An instrumentation system is currently under development which will measure many of the important parameters associated with the operation of an internal combustion engine. Some of these parameters include mass-fraction burn rate, ignition energy, and the indicated mean effective pressure. One of the characteristics of an internal combustion engine is the cycle-to-cycle variation of these parameters. A curve-averaging instrument has been produced which will generate the average curve, over 100 cycles, of any engine parameter. the average curve is described by 2048 discrete points which are displayed on an oscilloscope screen to facilitate recording and is available in real time. Input can be any parameter which is expressed as a + or - 10-volt signal. Operation of the curve-averaging instrument is defined between 100 and 6000 rpm. Provisions have also been made for averaging as many as four parameters simultaneously, with a subsequent decrease in resolution. This provides the means to correlate and perhaps interrelate the phenomena occurring in an internal combustion engine. This instrument has been used successfully on a 1975 Chevrolet V8 engine, and on a Continental 6-cylinder aircraft engine. While this instrument was designed for use on an internal combustion engine, with some modification it can be used to average any cyclically varying waveform.

  16. Average variograms to guide soil sampling

    NASA Astrophysics Data System (ADS)

    Kerry, R.; Oliver, M. A.

    2004-10-01

    To manage land in a site-specific way for agriculture requires detailed maps of the variation in the soil properties of interest. To predict accurately for mapping, the interval at which the soil is sampled should relate to the scale of spatial variation. A variogram can be used to guide sampling in two ways. A sampling interval of less than half the range of spatial dependence can be used, or the variogram can be used with the kriging equations to determine an optimal sampling interval to achieve a given tolerable error. A variogram might not be available for the site, but if the variograms of several soil properties were available on a similar parent material and or particular topographic positions an average variogram could be calculated from these. Averages of the variogram ranges and standardized average variograms from four different parent materials in southern England were used to suggest suitable sampling intervals for future surveys in similar pedological settings based on half the variogram range. The standardized average variograms were also used to determine optimal sampling intervals using the kriging equations. Similar sampling intervals were suggested by each method and the maps of predictions based on data at different grid spacings were evaluated for the different parent materials. Variograms of loss on ignition (LOI) taken from the literature for other sites in southern England with similar parent materials had ranges close to the average for a given parent material showing the possible wider application of such averages to guide sampling.

  17. Blood glucose monitoring: an overview.

    PubMed

    Whitmore, Catherine

    Glucose monitoring is done to obtain information on blood glucose levels to ensure a therapeutic regimen; the aim is to maintain consistent glucose levels and avoid hypoglycaemia and hyperglycaemia. Self-management is central to diabetes control. Diabetes is individual, so self-monitoring of blood glucose (SMBG) targets and frequency of testing must be decided to meet each patient's needs. Nurses have key roles in education and advocacy. They can educate patients on what affects glucose levels, why they need to carry out SMBG, and how to interpret and act on the results. Nurses also match glucose monitoring meters to patients' needs by considering ease of use, technical features and lifestyle. Access to testing supplies is sometimes restricted through blanket policies and nurses have an advocacy role here in challenging inappropriate restrictions.

  18. Glucose repression in Saccharomyces cerevisiae.

    PubMed

    Kayikci, Ömur; Nielsen, Jens

    2015-09-01

    Glucose is the primary source of energy for the budding yeast Saccharomyces cerevisiae. Although yeast cells can utilize a wide range of carbon sources, presence of glucose suppresses molecular activities involved in the use of alternate carbon sources as well as it represses respiration and gluconeogenesis. This dominant effect of glucose on yeast carbon metabolism is coordinated by several signaling and metabolic interactions that mainly regulate transcriptional activity but are also effective at post-transcriptional and post-translational levels. This review describes effects of glucose repression on yeast carbon metabolism with a focus on roles of the Snf3/Rgt2 glucose-sensing pathway and Snf1 signal transduction in establishment and relief of glucose repression. © FEMS 2015.

  19. Optoelectronic Apparatus Measures Glucose Noninvasively

    NASA Technical Reports Server (NTRS)

    Ansari, Rafat R.; Rovati, Luigi L.

    2003-01-01

    An optoelectronic apparatus has been invented as a noninvasive means of measuring the concentration of glucose in the human body. The apparatus performs polarimetric and interferometric measurements of the human eye to acquire data from which the concentration of glucose in the aqueous humor can be computed. Because of the importance of the concentration of glucose in human health, there could be a large potential market for instruments based on this apparatus.

  20. Prospective Study of Fasting Blood Glucose and Intracerebral Hemorrhagic Risk.

    PubMed

    Jin, Cheng; Li, Guohong; Rexrode, Kathryn M; Gurol, Mahmut E; Yuan, Xiaodong; Hui, Ying; Ruan, Chunyu; Vaidya, Anand; Wang, Yanxiu; Wu, Shouling; Gao, Xiang

    2018-01-01

    Although diabetes mellitus is an established independent risk factor for ischemic stroke, the association between fasting blood glucose and intracerebral hemorrhage (ICH) is limited and inconsistent. The objective of the current study was to examine the potential impact of long-term fasting blood glucose concentration on subsequent risk of ICH. This prospective study included 96 110 participants of the Kailuan study, living in Kailuan community, Tangshan city, China, who were free of cardiovascular diseases and cancer at baseline (2006). Fasting blood glucose concentration was measured in 2006, 2008, 2010, and 2012. Updated cumulative average fasting blood glucose concentration was used as primary exposure of the current study. Incident ICH from 2006 to 2015 was confirmed by review of medical records. During 817 531 person-years of follow-up, we identified 755 incident ICH cases. The nadir risk of ICH was observed at fasting blood glucose concentration of 5.3 mmol/L. The adjusted hazard ratios and their 95% confidence intervals (CIs) of ICH were 1.59 (95% CI, 1.26-2.02) for diabetes mellitus or fasting blood glucose ≥7.00 mmol/L, 1.31 (95% CI, 1.02-1.69) for impaired fasting blood glucose (fasting blood glucose, 6.10-6.99 mmol/L), 0.98 (95% CI, 0.78-1.22) for fasting blood glucose 5.60 to 6.09 mmol/L, and 2.04 (95% CI, 1.23-3.38) for hypoglycemia (fasting blood glucose, <4.00 mmol/L), comparing with normal fasting blood glucose 4.00 to 5.59 mmol/L. The results persisted after excluding individuals who used hypoglycemic, aspirin, antihypertensive agents, or anticoagulants, and those with intracerebral hemorrhagic cases occurred in the first 2 years of follow-up. In this large community-based cohort, low (<4.0 mmol/L) and high (≥6.1 mmol/L) fasting blood glucose concentrations were associated with higher risk of incident ICH, relative to fasting blood glucose concentrations of 4.00 to 6.09 mmol/L. © 2017 American Heart Association, Inc.

  1. A randomised trial of glucose tablets to aid smoking cessation.

    PubMed

    West, Robert; May, Sylvia; McEwen, Andy; McRobbie, Hayden; Hajek, Peter; Vangeli, Eleni

    2010-01-01

    Oral glucose has been found to decrease tobacco craving among abstaining smokers. One study has demonstrated an effect of glucose on short-term abstinence. There is a need to examine any long-term benefit of glucose on abstinence. To assess whether glucose tablets improve 6-month continuous abstinence rates compared with low-calorie placebo tablets. Smokers attempting to stop (n = 928) were randomised to receive glucose or sorbitol (placebo) in a double-blind placebo-controlled trial. All participants received group-based psychological support, and approximately half (n = 474) received nicotine replacement therapy (NRT), buproprion, or both. Smokers were seen weekly for 5 weeks and used tablets ad libitum, with a recommended minimum of 12 per day. Participants were recruited through general practitioner referral, word of mouth, and advertising. The participants were 38% male, smoked an average of 23.5 cigarettes per day, and had a mean age of 44 years. There were no significant pretreatment differences between groups. The primary outcome measure was continuous, CO-verified abstinence from the target quit date for 6 months. No significant effect of glucose tablets on abstinence was found (14.6% vs 13.4% abstinence in the glucose and placebo groups, respectively). However, there was a significant interaction with a glucose effect observed in smokers also receiving other medication (18.2% vs 12.6%, p < 0.05) but not otherwise (10.7% vs 14.3% ; p < 0.05 for the interaction). No significant effect of glucose tablets over and above sweet tasting tablets could be detected overall, but the possibility of an effect as an adjunct to NRT or bupropion merits further investigation.

  2. Average luminosity distance in inhomogeneous universes

    NASA Astrophysics Data System (ADS)

    Kostov, Valentin Angelov

    Using numerical ray tracing, the paper studies how the average distance modulus in an inhomogeneous universe differs from its homogeneous counterpart. The averaging is over all directions from a fixed observer not over all possible observers (cosmic), thus it is more directly applicable to our observations. Unlike previous studies, the averaging is exact, non-perturbative, an includes all possible non-linear effects. The inhomogeneous universes are represented by Sweese-cheese models containing random and simple cubic lattices of mass- compensated voids. The Earth observer is in the homogeneous cheese which has an Einstein - de Sitter metric. For the first time, the averaging is widened to include the supernovas inside the voids by assuming the probability for supernova emission from any comoving volume is proportional to the rest mass in it. For voids aligned in a certain direction, there is a cumulative gravitational lensing correction to the distance modulus that increases with redshift. That correction is present even for small voids and depends on the density contrast of the voids, not on their radius. Averaging over all directions destroys the cumulative correction even in a non-randomized simple cubic lattice of voids. Despite the well known argument for photon flux conservation, the average distance modulus correction at low redshifts is not zero due to the peculiar velocities. A formula for the maximum possible average correction as a function of redshift is derived and shown to be in excellent agreement with the numerical results. The formula applies to voids of any size that: (1) have approximately constant densities in their interior and walls, (2) are not in a deep nonlinear regime. The actual average correction calculated in random and simple cubic void lattices is severely damped below the predicted maximum. That is traced to cancelations between the corrections coming from the fronts and backs of different voids at the same redshift from the

  3. Random plasma glucose in serendipitous screening for glucose intolerance: screening for impaired glucose tolerance study 2.

    PubMed

    Ziemer, David C; Kolm, Paul; Foster, Jovonne K; Weintraub, William S; Vaccarino, Viola; Rhee, Mary K; Varughese, Rincy M; Tsui, Circe W; Koch, David D; Twombly, Jennifer G; Narayan, K M Venkat; Phillips, Lawrence S

    2008-05-01

    With positive results from diabetes prevention studies, there is interest in convenient ways to incorporate screening for glucose intolerance into routine care and to limit the need for fasting diagnostic tests. The aim of this study is to determine whether random plasma glucose (RPG) could be used to screen for glucose intolerance. This is a cross-sectional study. The participants of this study include a voluntary sample of 990 adults not known to have diabetes. RPG was measured, and each subject had a 75-g oral glucose tolerance test several weeks later. Glucose intolerance targets included diabetes, impaired glucose tolerance (IGT), and impaired fasting glucose(110) (IFG(110); fasting glucose, 110-125 mg/dl, and 2 h glucose < 140 mg/dl). Screening performance was measured by area under receiver operating characteristic curves (AROC). Mean age was 48 years, and body mass index (BMI) was 30.4 kg/m(2); 66% were women, and 52% were black; 5.1% had previously unrecognized diabetes, and 24.0% had any "high-risk" glucose intolerance (diabetes or IGT or IFG(110)). The AROC was 0.80 (95% CI 0.74-0.86) for RPG to identify diabetes and 0.72 (0.68-0.75) to identify any glucose intolerance, both highly significant (p < 0.001). Screening performance was generally consistent at different times of the day, regardless of meal status, and across a range of risk factors such as age, BMI, high density lipoprotein cholesterol, triglycerides, and blood pressure. RPG values should be considered by health care providers to be an opportunistic initial screening test and used to prompt further evaluation of patients at risk of glucose intolerance. Such "serendipitous screening" could help to identify unrecognized diabetes and prediabetes.

  4. Asynchronous Gossip for Averaging and Spectral Ranking

    NASA Astrophysics Data System (ADS)

    Borkar, Vivek S.; Makhijani, Rahul; Sundaresan, Rajesh

    2014-08-01

    We consider two variants of the classical gossip algorithm. The first variant is a version of asynchronous stochastic approximation. We highlight a fundamental difficulty associated with the classical asynchronous gossip scheme, viz., that it may not converge to a desired average, and suggest an alternative scheme based on reinforcement learning that has guaranteed convergence to the desired average. We then discuss a potential application to a wireless network setting with simultaneous link activation constraints. The second variant is a gossip algorithm for distributed computation of the Perron-Frobenius eigenvector of a nonnegative matrix. While the first variant draws upon a reinforcement learning algorithm for an average cost controlled Markov decision problem, the second variant draws upon a reinforcement learning algorithm for risk-sensitive control. We then discuss potential applications of the second variant to ranking schemes, reputation networks, and principal component analysis.

  5. Books Average Previous Decade of Economic Misery

    PubMed Central

    Bentley, R. Alexander; Acerbi, Alberto; Ormerod, Paul; Lampos, Vasileios

    2014-01-01

    For the 20th century since the Depression, we find a strong correlation between a ‘literary misery index’ derived from English language books and a moving average of the previous decade of the annual U.S. economic misery index, which is the sum of inflation and unemployment rates. We find a peak in the goodness of fit at 11 years for the moving average. The fit between the two misery indices holds when using different techniques to measure the literary misery index, and this fit is significantly better than other possible correlations with different emotion indices. To check the robustness of the results, we also analysed books written in German language and obtained very similar correlations with the German economic misery index. The results suggest that millions of books published every year average the authors' shared economic experiences over the past decade. PMID:24416159

  6. Benchmarking statistical averaging of spectra with HULLAC

    NASA Astrophysics Data System (ADS)

    Klapisch, Marcel; Busquet, Michel

    2008-11-01

    Knowledge of radiative properties of hot plasmas is important for ICF, astrophysics, etc When mid-Z or high-Z elements are present, the spectra are so complex that one commonly uses statistically averaged description of atomic systems [1]. In a recent experiment on Fe[2], performed under controlled conditions, high resolution transmission spectra were obtained. The new version of HULLAC [3] allows the use of the same model with different levels of details/averaging. We will take advantage of this feature to check the effect of averaging with comparison with experiment. [1] A Bar-Shalom, J Oreg, and M Klapisch, J. Quant. Spectros. Rad. Transf. 65, 43 (2000). [2] J. E. Bailey, G. A. Rochau, C. A. Iglesias et al., Phys. Rev. Lett. 99, 265002-4 (2007). [3]. M. Klapisch, M. Busquet, and A. Bar-Shalom, AIP Conference Proceedings 926, 206-15 (2007).

  7. Books average previous decade of economic misery.

    PubMed

    Bentley, R Alexander; Acerbi, Alberto; Ormerod, Paul; Lampos, Vasileios

    2014-01-01

    For the 20(th) century since the Depression, we find a strong correlation between a 'literary misery index' derived from English language books and a moving average of the previous decade of the annual U.S. economic misery index, which is the sum of inflation and unemployment rates. We find a peak in the goodness of fit at 11 years for the moving average. The fit between the two misery indices holds when using different techniques to measure the literary misery index, and this fit is significantly better than other possible correlations with different emotion indices. To check the robustness of the results, we also analysed books written in German language and obtained very similar correlations with the German economic misery index. The results suggest that millions of books published every year average the authors' shared economic experiences over the past decade.

  8. Aperture averaging in strong oceanic turbulence

    NASA Astrophysics Data System (ADS)

    Gökçe, Muhsin Caner; Baykal, Yahya

    2018-04-01

    Receiver aperture averaging technique is employed in underwater wireless optical communication (UWOC) systems to mitigate the effects of oceanic turbulence, thus to improve the system performance. The irradiance flux variance is a measure of the intensity fluctuations on a lens of the receiver aperture. Using the modified Rytov theory which uses the small-scale and large-scale spatial filters, and our previously presented expression that shows the atmospheric structure constant in terms of oceanic turbulence parameters, we evaluate the irradiance flux variance and the aperture averaging factor of a spherical wave in strong oceanic turbulence. Irradiance flux variance variations are examined versus the oceanic turbulence parameters and the receiver aperture diameter are examined in strong oceanic turbulence. Also, the effect of the receiver aperture diameter on the aperture averaging factor is presented in strong oceanic turbulence.

  9. Evaluation of a Novel Glucose Area Under the Curve (AUC) Monitoring System: Comparison with the AUC by Continuous Glucose Monitoring

    PubMed Central

    Maegawa, Hiroshi; Morino, Katsutaro; Nishio, Yoshihiko; Sato, Toshiyuki; Okada, Seiki; Kikkawa, Yasuo; Watanabe, Toshihiro; Nakajima, Hiromu; Kashiwagi, Atsunori

    2016-01-01

    Background Management of postprandial hyperglycemia is a key aspect in diabetes treatment. We developed a novel system to measure glucose area under the curve (AUC) using minimally invasive interstitial fluid extraction technology (MIET) for simple monitoring of postprandial glucose excursions. In this study, we evaluated the relationship between our system and continuous glucose monitoring (CGM) by comparing glucose AUC obtained using MIET with that obtained using CGM for a long duration. Methods Twenty diabetic inpatients wearing a CGM system were enrolled. For MIET measurement, a plastic microneedle array was applied to the skin as pretreatment, and hydrogels were placed on the pretreated area to collect interstitial fluid. Hydrogels were replaced every 2 or 4 hours and AUC was predicted on the basis of glucose and sodium ion levels. Results AUC predicted by MIET correlated well with that measured by CGM (r=0.93). Good performances of both consecutive 2- and 4-hour measurements were observed (measurement error: 11.7%±10.2% for 2 hours and 11.1%±7.9% for 4 hours), indicating the possibility of repetitive measurements up to 8 hours. The influence of neither glucose fluctuation nor average glucose level over the measurement accuracy was observed through 8 hours. Conclusion Our system showed good relationship with AUC values from CGM up to 8 hours, indicating that single pretreatment can cover a large portion of glucose excursion in a day. These results indicated possibility of our system to contribute to convenient monitoring of glucose excursions for a long duration. PMID:27535643

  10. When Is the Local Average Treatment Close to the Average? Evidence from Fertility and Labor Supply

    ERIC Educational Resources Information Center

    Ebenstein, Avraham

    2009-01-01

    The local average treatment effect (LATE) may differ from the average treatment effect (ATE) when those influenced by the instrument are not representative of the overall population. Heterogeneity in treatment effects may imply that parameter estimates from 2SLS are uninformative regarding the average treatment effect, motivating a search for…

  11. Model averaging and muddled multimodel inferences.

    PubMed

    Cade, Brian S

    2015-09-01

    Three flawed practices associated with model averaging coefficients for predictor variables in regression models commonly occur when making multimodel inferences in analyses of ecological data. Model-averaged regression coefficients based on Akaike information criterion (AIC) weights have been recommended for addressing model uncertainty but they are not valid, interpretable estimates of partial effects for individual predictors when there is multicollinearity among the predictor variables. Multicollinearity implies that the scaling of units in the denominators of the regression coefficients may change across models such that neither the parameters nor their estimates have common scales, therefore averaging them makes no sense. The associated sums of AIC model weights recommended to assess relative importance of individual predictors are really a measure of relative importance of models, with little information about contributions by individual predictors compared to other measures of relative importance based on effects size or variance reduction. Sometimes the model-averaged regression coefficients for predictor variables are incorrectly used to make model-averaged predictions of the response variable when the models are not linear in the parameters. I demonstrate the issues with the first two practices using the college grade point average example extensively analyzed by Burnham and Anderson. I show how partial standard deviations of the predictor variables can be used to detect changing scales of their estimates with multicollinearity. Standardizing estimates based on partial standard deviations for their variables can be used to make the scaling of the estimates commensurate across models, a necessary but not sufficient condition for model averaging of the estimates to be sensible. A unimodal distribution of estimates and valid interpretation of individual parameters are additional requisite conditions. The standardized estimates or equivalently the t

  12. Model averaging and muddled multimodel inferences

    USGS Publications Warehouse

    Cade, Brian S.

    2015-01-01

    Three flawed practices associated with model averaging coefficients for predictor variables in regression models commonly occur when making multimodel inferences in analyses of ecological data. Model-averaged regression coefficients based on Akaike information criterion (AIC) weights have been recommended for addressing model uncertainty but they are not valid, interpretable estimates of partial effects for individual predictors when there is multicollinearity among the predictor variables. Multicollinearity implies that the scaling of units in the denominators of the regression coefficients may change across models such that neither the parameters nor their estimates have common scales, therefore averaging them makes no sense. The associated sums of AIC model weights recommended to assess relative importance of individual predictors are really a measure of relative importance of models, with little information about contributions by individual predictors compared to other measures of relative importance based on effects size or variance reduction. Sometimes the model-averaged regression coefficients for predictor variables are incorrectly used to make model-averaged predictions of the response variable when the models are not linear in the parameters. I demonstrate the issues with the first two practices using the college grade point average example extensively analyzed by Burnham and Anderson. I show how partial standard deviations of the predictor variables can be used to detect changing scales of their estimates with multicollinearity. Standardizing estimates based on partial standard deviations for their variables can be used to make the scaling of the estimates commensurate across models, a necessary but not sufficient condition for model averaging of the estimates to be sensible. A unimodal distribution of estimates and valid interpretation of individual parameters are additional requisite conditions. The standardized estimates or equivalently the

  13. An improved moving average technical trading rule

    NASA Astrophysics Data System (ADS)

    Papailias, Fotis; Thomakos, Dimitrios D.

    2015-06-01

    This paper proposes a modified version of the widely used price and moving average cross-over trading strategies. The suggested approach (presented in its 'long only' version) is a combination of cross-over 'buy' signals and a dynamic threshold value which acts as a dynamic trailing stop. The trading behaviour and performance from this modified strategy are different from the standard approach with results showing that, on average, the proposed modification increases the cumulative return and the Sharpe ratio of the investor while exhibiting smaller maximum drawdown and smaller drawdown duration than the standard strategy.

  14. Average: the juxtaposition of procedure and context

    NASA Astrophysics Data System (ADS)

    Watson, Jane; Chick, Helen; Callingham, Rosemary

    2014-09-01

    This paper presents recent data on the performance of 247 middle school students on questions concerning average in three contexts. Analysis includes considering levels of understanding linking definition and context, performance across contexts, the relative difficulty of tasks, and difference in performance for male and female students. The outcomes lead to a discussion of the expectations of the curriculum and its implementation, as well as assessment, in relation to students' skills in carrying out procedures and their understanding about the meaning of average in context.

  15. Glucose tolerance test - non-pregnant

    MedlinePlus

    Oral glucose tolerance test - non-pregnant; OGTT - non-pregnant; Diabetes - glucose tolerance test; Diabetic - glucose tolerance test ... The most common glucose tolerance test is the oral glucose ... the test begins, a sample of blood will be taken. You will then ...

  16. Glucose monitoring system using nanopellets.

    PubMed

    Rajasekaran, C; Nirmala, Madian; Jayanthi, K B

    2017-02-01

    The combination of the fields of software engineering, gadgets, and science has stood out among the most revolutionary future innovations. Health issues have been the focus of various engaging and explanatory studies. One such health-related dilemma is diabetes. Diabetes at its serious stage results in impaired vision. Increase in the glucose level is a critical parameter that could result in hyperglycaemia, hypoglycaemia, massive heart attack, strokes, and aneurysms. Monitoring the glucose level in blood is one of the control measures for diabetes in the affected population. A glucose monitoring framework interminably measures and screens the glucose level in blood. A novel framework for measuring the glucose level is proposed in this study. This study employs nanopellets that evaluate the glucose level. When the glucose level increases or decreases, it is continuously recorded and displayed using a microcontroller (mixed signal processor (MSP) 430). The data are then sent to the physician through global system for mobile communication. The typical blood glucose level of human being ranges from 70 to 110 mg/dl. When the insulin level builds up to certain point, hyperglycaemia occurs. When decreases, hypoglycaemia occurs. Hyperglycaemia leads to cataracts, oedema, hypertension, polyuria, and polydipsia. Hypoglycaemia causes perplexity, energy, insensateness, coma, and death.

  17. Alginate cryogel based glucose biosensor

    NASA Astrophysics Data System (ADS)

    Fatoni, Amin; Windy Dwiasi, Dian; Hermawan, Dadan

    2016-02-01

    Cryogel is macroporous structure provides a large surface area for biomolecule immobilization. In this work, an alginate cryogel based biosensor was developed to detect glucose. The cryogel was prepared using alginate cross-linked by calcium chloride under sub-zero temperature. This porous structure was growth in a 100 μL micropipette tip with a glucose oxidase enzyme entrapped inside the cryogel. The glucose detection was based on the colour change of redox indicator, potassium permanganate, by the hydrogen peroxide resulted from the conversion of glucose. The result showed a porous structure of alginate cryogel with pores diameter of 20-50 μm. The developed glucose biosensor was showed a linear response in the glucose detection from 1.0 to 5.0 mM with a regression of y = 0.01x+0.02 and R2 of 0.994. Furthermore, the glucose biosensor was showed a high operational stability up to 10 times of uninterrupted glucose detections.

  18. Initial Conditions in the Averaging Cognitive Model

    ERIC Educational Resources Information Center

    Noventa, S.; Massidda, D.; Vidotto, G.

    2010-01-01

    The initial state parameters s[subscript 0] and w[subscript 0] are intricate issues of the averaging cognitive models in Information Integration Theory. Usually they are defined as a measure of prior information (Anderson, 1981; 1982) but there are no general rules to deal with them. In fact, there is no agreement as to their treatment except in…

  19. Bayesian Model Averaging for Propensity Score Analysis

    ERIC Educational Resources Information Center

    Kaplan, David; Chen, Jianshen

    2013-01-01

    The purpose of this study is to explore Bayesian model averaging in the propensity score context. Previous research on Bayesian propensity score analysis does not take into account model uncertainty. In this regard, an internally consistent Bayesian framework for model building and estimation must also account for model uncertainty. The…

  20. Reliability Estimates for Undergraduate Grade Point Average

    ERIC Educational Resources Information Center

    Westrick, Paul A.

    2017-01-01

    Undergraduate grade point average (GPA) is a commonly employed measure in educational research, serving as a criterion or as a predictor depending on the research question. Over the decades, researchers have used a variety of reliability coefficients to estimate the reliability of undergraduate GPA, which suggests that there has been no consensus…

  1. Conceptual Analysis of System Average Water Stability

    NASA Astrophysics Data System (ADS)

    Zhang, H.

    2016-12-01

    Averaging over time and area, the precipitation in an ecosystem (SAP - system average precipitation) depends on the average surface temperature and relative humidity (RH) in the system if uniform convection is assumed. RH depends on the evapotranspiration of the system (SAE - system average evapotranspiration). There is a non-linear relationship between SAP and SAE. Studying this relationship can lead mechanistic understanding of the ecosystem health status and trend under different setups. If SAP is higher than SAE, the system will have a water runoff which flows out through rivers. If SAP is lower than SAE, irrigation is needed to maintain the vegetation status. This presentation will give a conceptual analysis of the stability in this relationship under different assumed areas, water or forest coverages, elevations and latitudes. This analysis shows that desert is a stable system. Water circulation in basins is also stabilized at a specific SAP based on the basin profile. It further shows that deforestation will reduce SAP, and can flip the system to an irrigation required status. If no irrigation is provided, the system will automatically reduce to its stable point - desert, which is extremely difficult to turn around.

  2. How Young Is Standard Average European?

    ERIC Educational Resources Information Center

    Haspelmath, Martin

    1998-01-01

    An analysis of Standard Average European, a European linguistic area, looks at 11 of its features (definite, indefinite articles, have-perfect, participial passive, antiaccusative prominence, nominative experiencers, dative external possessors, negation/negative pronouns, particle comparatives, A-and-B conjunction, relative clauses, verb fronting…

  3. Average Annual Rainfall Over the Globe

    NASA Astrophysics Data System (ADS)

    Agrawal, D. C.

    2013-12-01

    The atmospheric recycling of water is a very important phenomenon on the globe because it not only refreshes the water but it also redistributes it over land and oceans/rivers/lakes throughout the globe. This is made possible by the solar energy intercepted by the Earth. The half of the globe facing the Sun, on the average, intercepts 1.74×1017 J of solar radiation per second and it is divided over various channels as given in Table 1. It keeps our planet warm and maintains its average temperature2 of 288 K with the help of the atmosphere in such a way that life can survive. It also recycles the water in the oceans/rivers/ lakes by initial evaporation and subsequent precipitation; the average annual rainfall over the globe is around one meter. According to M. King Hubbert the amount of solar power going into the evaporation and precipitation channel is 4.0×1016 W. Students can verify the value of average annual rainfall over the globe by utilizing this part of solar energy. This activity is described in the next section.

  4. Children's Concepts of Average and Representativeness.

    ERIC Educational Resources Information Center

    Mokros, Jan; Russell, Susan Jo

    This paper reports a study to address two questions concerning children's understanding of average: How do children construct and interpret representativeness within the context of data sets? and How do children think about the mean as a particular mathematical definition and relationship? Twenty-one students (seven each of 4th, 6th, and 8th…

  5. Average thermal characteristics of solar wind electrons

    NASA Technical Reports Server (NTRS)

    Montgomery, M. D.

    1972-01-01

    Average solar wind electron properties based on a 1 year Vela 4 data sample-from May 1967 to May 1968 are presented. Frequency distributions of electron-to-ion temperature ratio, electron thermal anisotropy, and thermal energy flux are presented. The resulting evidence concerning heat transport in the solar wind is discussed.

  6. A Functional Measurement Study on Averaging Numerosity

    ERIC Educational Resources Information Center

    Tira, Michael D.; Tagliabue, Mariaelena; Vidotto, Giulio

    2014-01-01

    In two experiments, participants judged the average numerosity between two sequentially presented dot patterns to perform an approximate arithmetic task. In Experiment 1, the response was given on a 0-20 numerical scale (categorical scaling), and in Experiment 2, the response was given by the production of a dot pattern of the desired numerosity…

  7. Measuring Time-Averaged Blood Pressure

    NASA Technical Reports Server (NTRS)

    Rothman, Neil S.

    1988-01-01

    Device measures time-averaged component of absolute blood pressure in artery. Includes compliant cuff around artery and external monitoring unit. Ceramic construction in monitoring unit suppresses ebb and flow of pressure-transmitting fluid in sensor chamber. Transducer measures only static component of blood pressure.

  8. Why Johnny Can Be Average Today.

    ERIC Educational Resources Information Center

    Sturrock, Alan

    1997-01-01

    During a (hypothetical) phone interview with a university researcher, an elementary principal reminisced about a lifetime of reading groups with unmemorable names, medium-paced math problems, patchworked social studies/science lessons, and totally "average" IQ and batting scores. The researcher hung up at the mention of bell-curved assembly lines…

  9. Average Nuclear Potentials from Selfconsistent Semiclassical Calculations

    NASA Astrophysics Data System (ADS)

    Bartel, J.

    1999-03-01

    Using the selfconsistent semiclassical Extended Thomas-Fermi (ETF) method up to 4th order in connection with Skyrme forces it is demonstrated that the neutron and proton average potentials obtained using the semiclassical functionals τ (ETF)[ρ] and vec {J}(ETF)[ρ] reproduce the corresponding Hartree-Fock fields extremely well, except for shell oscillations in the nuclear center.

  10. The Most Productive Years of Average Astronomers

    NASA Astrophysics Data System (ADS)

    Abt, Helmut A.

    2017-11-01

    We learned previously that geniuses and outstanding scientists have peak productivities in their 30s but produce little late in life. This time we consider average astronomers who have completed their careers (25 American Astronomical Society members who died recently) and found that they peak in their mid 40s and did half of their life's important output after age 50.

  11. Glucose sensor realized with photonic crystal fiber-based Sagnac interferometer

    NASA Astrophysics Data System (ADS)

    An, Guowen; Li, Shuguang; An, Yinghong; Wang, Haiyang; Zhang, Xuenan

    2017-12-01

    A compact glucose sensor is proposed by using a short length of photonic crystal fiber inserted in a Sagnac loop interferometer. Spectrum shift in response to the RI of glucose solution with a high average sensitivity of 22 130 nm/RIU is achieved, equivalent to 0.76 mg/dL of glucose in water, which is lower than 70 mg/dL for efficient detection of hypoglycemia episodes. And the simplicity of the fiber structure makes the sensor production very cost effective. We aimed to provide a potential effective method for glucose detection in patients with hypoglycemia.

  12. Glucose tolerance in two unacculturated Indian tribes of Brazil.

    PubMed

    Spielman, R S; Fajans, S S; Neel, J V; Pek, S; Floyd, J C; Oliver, W J

    1982-08-01

    Plasma levels of glucose, insulin, growth hormone, and pancreatic polypeptide in response to a standard oral glucose load were studied in the Yanomama and the Marubo, two relatively unacculturated Amerindian tribes of the Brazilian Amazon. The findings in the two tribes differed significantly from each other and in the degree of deviation from control subjects. The average responses in both tribes differed significantly from those of age- and sex-matched Caucasoid control subjects studied in Ann Arbor, Michigan; however, of the two tribes, the Marubo, the more acculturated group, resembled the controls more closely. Plasma concentrations of glucose and the hormones at three time points (fasting, 1 h, 2 h) were compared by means of a multivariate analysis. When the Marubo were compared with the control subjects, the only highly significant difference was in the plasma glucose concentrations (all three points were higher in the Marubo); however, the Yanomama differed significantly from the control subjects with respect to all four plasma indicators (p less than 0.05). Unlike the Marubo, the Yanomama showed no significant rise in plasma glucose at 1 h and no decrease at 2 h. Neither tribe exhibited the bimodality of the 2 h glucose value characteristic of acculturated Amerindians, such as the Pima, but the samples studied were small.

  13. Continuous glucose monitoring on the ICU using a subcutaneous sensor.

    PubMed

    Punke, M A; Decker, C; Wodack, K; Reuter, D A; Kluge, S

    2015-06-01

    Hypoglycemia is a frequent and feared complication of insulin therapy on the intensive care unit (ICU). Sedated patients in particular are at risk for hypoglycemia due to the absence of clinical symptoms. Furthermore, recent studies point to a correlation between the variability of blood glucose and mortality. Therefore, continuous glucose monitoring has the potential to influence outcome due to a better control of blood glucose in critically ill patients. We evaluated the efficacy, accuracy and safety of a new commercially available subcutaneous continuous glucose monitoring system (sCGM; Sentrino®, Medtronic) in a pilot study in critically ill adult patients. sCGM data were recorded for up to 72 h and values were compared with blood glucose values measured by cassette-based blood gas analyzer (BGA). A total of 14 patients (eight male, six female), with a mean age of 62.1 ± 9.8 years, referred to the ICU after major abdominal surgery were studied. The average simplified acute physiology score (SAPS II) was 35 ± 9. Three patients had known type II diabetes. The average runtime of sensors was 44.1 ± 22.1 h. In comparison to BGA, measurement of blood glucose by sCGM revealed an accuracy of 1.5 mg/dl, and a precision of +34.2 mg/dl to -31.2 mg/dl. Linn's concordance correlation coefficient yielded 0.74 with a 95% confidence interval of 0.68-0.78. No hypoglycemic events, defined as a blood glucose level below 70 mg/dl, occurred during treatment. sCGM monitoring via a subcutaneous sensor demonstrated high accuracy and considerable variability compared to blood gas samples, even in critically ill patients.

  14. Metrics for glycaemic control - from HbA1c to continuous glucose monitoring.

    PubMed

    Kovatchev, Boris P

    2017-07-01

    As intensive treatment to lower levels of HbA 1c characteristically results in an increased risk of hypoglycaemia, patients with diabetes mellitus face a life-long optimization problem to reduce average levels of glycaemia and postprandial hyperglycaemia while simultaneously avoiding hypoglycaemia. This optimization can only be achieved in the context of lowering glucose variability. In this Review, I discuss topics that are related to the assessment, quantification and optimal control of glucose fluctuations in diabetes mellitus. I focus on markers of average glycaemia and the utility and/or shortcomings of HbA 1c as a 'gold-standard' metric of glycaemic control; the notion that glucose variability is characterized by two principal dimensions, amplitude and time; measures of glucose variability that are based on either self-monitoring of blood glucose data or continuous glucose monitoring (CGM); and the control of average glycaemia and glucose variability through the use of pharmacological agents or closed-loop control systems commonly referred to as the 'artificial pancreas'. I conclude that HbA 1c and the various available metrics of glucose variability reflect the management of diabetes mellitus on different timescales, ranging from months (for HbA 1c ) to minutes (for CGM). Comprehensive assessment of the dynamics of glycaemic fluctuations is therefore crucial for providing accurate and complete information to the patient, physician, automated decision-support or artificial-pancreas system.

  15. Genetics Home Reference: glucose-galactose malabsorption

    MedlinePlus

    ... down into glucose and another simple sugar called fructose, and lactose is broken down into glucose and ... infant formulas. However, they are able to digest fructose-based formulas that do not contain glucose or ...

  16. Rigid shape matching by segmentation averaging.

    PubMed

    Wang, Hongzhi; Oliensis, John

    2010-04-01

    We use segmentations to match images by shape. The new matching technique does not require point-to-point edge correspondence and is robust to small shape variations and spatial shifts. To address the unreliability of segmentations computed bottom-up, we give a closed form approximation to an average over all segmentations. Our method has many extensions, yielding new algorithms for tracking, object detection, segmentation, and edge-preserving smoothing. For segmentation, instead of a maximum a posteriori approach, we compute the "central" segmentation minimizing the average distance to all segmentations of an image. For smoothing, instead of smoothing images based on local structures, we smooth based on the global optimal image structures. Our methods for segmentation, smoothing, and object detection perform competitively, and we also show promising results in shape-based tracking.

  17. Warp-averaging event-related potentials.

    PubMed

    Wang, K; Begleiter, H; Porjesz, B

    2001-10-01

    To align the repeated single trials of the event-related potential (ERP) in order to get an improved estimate of the ERP. A new implementation of the dynamic time warping is applied to compute a warp-average of the single trials. The trilinear modeling method is applied to filter the single trials prior to alignment. Alignment is based on normalized signals and their estimated derivatives. These features reduce the misalignment due to aligning the random alpha waves, explaining amplitude differences in latency differences, or the seemingly small amplitudes of some components. Simulations and applications to visually evoked potentials show significant improvement over some commonly used methods. The new implementation of the dynamic time warping can be used to align the major components (P1, N1, P2, N2, P3) of the repeated single trials. The average of the aligned single trials is an improved estimate of the ERP. This could lead to more accurate results in subsequent analysis.

  18. Averaging of elastic constants for polycrystals

    DOE PAGES

    Blaschke, Daniel N.

    2017-10-13

    Many materials of interest are polycrystals, i.e., aggregates of single crystals. Randomly distributed orientations of single crystals lead to macroscopically isotropic properties. Here in this paper, we briefly review strategies of calculating effective isotropic second and third order elastic constants from the single crystal ones. Our main emphasis is on single crystals of cubic symmetry. Specifically, the averaging of third order elastic constants has not been particularly successful in the past, and discrepancies have often been attributed to texturing of polycrystals as well as to uncertainties in the measurement of elastic constants of both poly and single crystals. While thismore » may well be true, we also point out here shortcomings in the theoretical averaging framework.« less

  19. Statistical errors in molecular dynamics averages

    SciTech Connect

    Schiferl, S.K.; Wallace, D.C.

    1985-11-15

    A molecular dynamics calculation produces a time-dependent fluctuating signal whose average is a thermodynamic quantity of interest. The average of the kinetic energy, for example, is proportional to the temperature. A procedure is described for determining when the molecular dynamics system is in equilibrium with respect to a given variable, according to the condition that the mean and the bandwidth of the signal should be sensibly constant in time. Confidence limits for the mean are obtained from an analysis of a finite length of the equilibrium signal. The role of serial correlation in this analysis is discussed. The occurence ofmore » unstable behavior in molecular dynamics data is noted, and a statistical test for a level shift is described.« less

  20. Average chemical composition of the lunar surface

    NASA Technical Reports Server (NTRS)

    Turkevich, A. L.

    1973-01-01

    The available data on the chemical composition of the lunar surface at eleven sites (3 Surveyor, 5 Apollo and 3 Luna) are used to estimate the amounts of principal chemical elements (those present in more than about 0.5% by atom) in average lunar surface material. The terrae of the moon differ from the maria in having much less iron and titanium and appreciably more aluminum and calcium.

  1. Average Annual Rainfall over the Globe

    ERIC Educational Resources Information Center

    Agrawal, D. C.

    2013-01-01

    The atmospheric recycling of water is a very important phenomenon on the globe because it not only refreshes the water but it also redistributes it over land and oceans/rivers/lakes throughout the globe. This is made possible by the solar energy intercepted by the Earth. The half of the globe facing the Sun, on the average, intercepts 1.74 ×…

  2. Disk-averaged synthetic spectra of Mars.

    PubMed

    Tinetti, Giovanna; Meadows, Victoria S; Crisp, David; Fong, William; Velusamy, Thangasamy; Snively, Heather

    2005-08-01

    The principal goal of the NASA Terrestrial Planet Finder (TPF) and European Space Agency's Darwin mission concepts is to directly detect and characterize extrasolar terrestrial (Earthsized) planets. This first generation of instruments is expected to provide disk-averaged spectra with modest spectral resolution and signal-to-noise. Here we use a spatially and spectrally resolved model of a Mars-like planet to study the detectability of a planet's surface and atmospheric properties from disk-averaged spectra. We explore the detectability as a function of spectral resolution and wavelength range, for both the proposed visible coronograph (TPFC) and mid-infrared interferometer (TPF-I/Darwin) architectures. At the core of our model is a spectrum-resolving (line-by-line) atmospheric/surface radiative transfer model. This model uses observational data as input to generate a database of spatially resolved synthetic spectra for a range of illumination conditions and viewing geometries. The model was validated against spectra recorded by the Mars Global Surveyor-Thermal Emission Spectrometer and the Mariner 9-Infrared Interferometer Spectrometer. Results presented here include disk-averaged synthetic spectra, light curves, and the spectral variability at visible and mid-infrared wavelengths for Mars as a function of viewing angle, illumination, and season. We also considered the differences in the spectral appearance of an increasingly ice-covered Mars, as a function of spectral resolution, signal-to-noise and integration time for both TPF-C and TPFI/ Darwin.

  3. Disk-averaged synthetic spectra of Mars

    NASA Technical Reports Server (NTRS)

    Tinetti, Giovanna; Meadows, Victoria S.; Crisp, David; Fong, William; Velusamy, Thangasamy; Snively, Heather

    2005-01-01

    The principal goal of the NASA Terrestrial Planet Finder (TPF) and European Space Agency's Darwin mission concepts is to directly detect and characterize extrasolar terrestrial (Earthsized) planets. This first generation of instruments is expected to provide disk-averaged spectra with modest spectral resolution and signal-to-noise. Here we use a spatially and spectrally resolved model of a Mars-like planet to study the detectability of a planet's surface and atmospheric properties from disk-averaged spectra. We explore the detectability as a function of spectral resolution and wavelength range, for both the proposed visible coronograph (TPFC) and mid-infrared interferometer (TPF-I/Darwin) architectures. At the core of our model is a spectrum-resolving (line-by-line) atmospheric/surface radiative transfer model. This model uses observational data as input to generate a database of spatially resolved synthetic spectra for a range of illumination conditions and viewing geometries. The model was validated against spectra recorded by the Mars Global Surveyor-Thermal Emission Spectrometer and the Mariner 9-Infrared Interferometer Spectrometer. Results presented here include disk-averaged synthetic spectra, light curves, and the spectral variability at visible and mid-infrared wavelengths for Mars as a function of viewing angle, illumination, and season. We also considered the differences in the spectral appearance of an increasingly ice-covered Mars, as a function of spectral resolution, signal-to-noise and integration time for both TPF-C and TPFI/ Darwin.

  4. Modern average global sea-surface temperature

    USGS Publications Warehouse

    Schweitzer, Peter N.

    1993-01-01

    The data contained in this data set are derived from the NOAA Advanced Very High Resolution Radiometer Multichannel Sea Surface Temperature data (AVHRR MCSST), which are obtainable from the Distributed Active Archive Center at the Jet Propulsion Laboratory (JPL) in Pasadena, Calif. The JPL tapes contain weekly images of SST from October 1981 through December 1990 in nine regions of the world ocean: North Atlantic, Eastern North Atlantic, South Atlantic, Agulhas, Indian, Southeast Pacific, Southwest Pacific, Northeast Pacific, and Northwest Pacific. This data set represents the results of calculations carried out on the NOAA data and also contains the source code of the programs that made the calculations. The objective was to derive the average sea-surface temperature of each month and week throughout the whole 10-year series, meaning, for example, that data from January of each year would be averaged together. The result is 12 monthly and 52 weekly images for each of the oceanic regions. Averaging the images in this way tends to reduce the number of grid cells that lack valid data and to suppress interannual variability.

  5. Viewpoint: observations on scaled average bioequivalence.

    PubMed

    Patterson, Scott D; Jones, Byron

    2012-01-01

    The two one-sided test procedure (TOST) has been used for average bioequivalence testing since 1992 and is required when marketing new formulations of an approved drug. TOST is known to require comparatively large numbers of subjects to demonstrate bioequivalence for highly variable drugs, defined as those drugs having intra-subject coefficients of variation greater than 30%. However, TOST has been shown to protect public health when multiple generic formulations enter the marketplace following patent expiration. Recently, scaled average bioequivalence (SABE) has been proposed as an alternative statistical analysis procedure for such products by multiple regulatory agencies. SABE testing requires that a three-period partial replicate cross-over or full replicate cross-over design be used. Following a brief summary of SABE analysis methods applied to existing data, we will consider three statistical ramifications of the proposed additional decision rules and the potential impact of implementation of scaled average bioequivalence in the marketplace using simulation. It is found that a constraint being applied is biased, that bias may also result from the common problem of missing data and that the SABE methods allow for much greater changes in exposure when generic-generic switching occurs in the marketplace. Copyright © 2011 John Wiley & Sons, Ltd.

  6. Model averaging, optimal inference, and habit formation

    PubMed Central

    FitzGerald, Thomas H. B.; Dolan, Raymond J.; Friston, Karl J.

    2014-01-01

    Postulating that the brain performs approximate Bayesian inference generates principled and empirically testable models of neuronal function—the subject of much current interest in neuroscience and related disciplines. Current formulations address inference and learning under some assumed and particular model. In reality, organisms are often faced with an additional challenge—that of determining which model or models of their environment are the best for guiding behavior. Bayesian model averaging—which says that an agent should weight the predictions of different models according to their evidence—provides a principled way to solve this problem. Importantly, because model evidence is determined by both the accuracy and complexity of the model, optimal inference requires that these be traded off against one another. This means an agent's behavior should show an equivalent balance. We hypothesize that Bayesian model averaging plays an important role in cognition, given that it is both optimal and realizable within a plausible neuronal architecture. We outline model averaging and how it might be implemented, and then explore a number of implications for brain and behavior. In particular, we propose that model averaging can explain a number of apparently suboptimal phenomena within the framework of approximate (bounded) Bayesian inference, focusing particularly upon the relationship between goal-directed and habitual behavior. PMID:25018724

  7. Osmotic load from glucose polymers.

    PubMed

    Koo, W W; Poh, D; Leong, M; Tam, Y K; Succop, P; Checkland, E G

    1991-01-01

    Glucose polymer is a carbohydrate source with variable chain lengths of glucose units which may result in variable osmolality. The osmolality of two commercial glucose polymers was measured in reconstituted powder infant formulas, and the change in osmolality of infant milk formulas at the same increases in energy density (67 kcal/dL to 81 and 97 kcal/dL) from the use of additional milk powder or glucose polymers was compared. All samples were prepared from powders (to nearest 0.1 mg), and osmolality was measured by freezing point depression. For both glucose polymers the within-batch variability of the measured osmolality was less than 3.5%, and between-batch variability of the measured osmolality was less than 9.6%. The measured osmolality varies linearly with energy density (p less than 0.001) and was highest in infant formula reconstituted from milk powder alone. However, there exist significant differences in the measured osmolality between different glucose polymer preparations. At high energy densities (greater than or equal to 97 kcal/dL), infant milk formulas prepared with milk powder alone or with the addition of certain glucose polymer preparation may have high osmolality (greater than or equal to 450 mosm/kg) and theoretically predispose the infant to complications of hyperosmotic feeds.

  8. Conversion of glucose to sorbose

    DOEpatents

    Davis, Mark E.; Gounder, Rajamani

    2016-02-09

    The present invention is directed to methods for preparing sorbose from glucose, said method comprising: (a) contacting the glucose with a silica-containing structure comprising a zeolite having a topology of a 12 membered-ring or larger, an ordered mesoporous silica material, or an amorphous silica, said structure containing Lewis acidic Ti.sup.4+ or Zr.sup.4+ or both Ti.sup.4+ and Zr.sup.4+ framework centers, said contacting conducted under reaction conditions sufficient to isomerize the glucose to sorbose. The sorbose may be (b) separated or isolated; or (c) converted to ascorbic acid.

  9. The Fallacy of Average: How Using HbA1c Alone to Assess Glycemic Control Can Be Misleading.

    PubMed

    Beck, Roy W; Connor, Crystal G; Mullen, Deborah M; Wesley, David M; Bergenstal, Richard M

    2017-08-01

    HbA 1c is a v aluable metric for comparing treatment groups in a randomized trial, for assessing glycemic trends in a population over time, or for cross-sectional comparisons of glycemic control in different populations. However, what is not widely appreciated is that HbA 1c may not be a good indicator of an individual patient's glycemic control because of the wide range of mean glucose concentrations and glucose profiles that can be associated with a given HbA 1c level. To illustrate this point, we plotted mean glucose measured with continuous glucose monitoring (CGM) versus central laboratory-measured HbA 1c in 387 participants in three randomized trials, showing that not infrequently HbA 1c may underestimate or overestimate mean glucose, sometimes substantially. Thus, if HbA 1c is to be used to assess glycemic control, it is imperative to know the patient's actual mean glucose to understand how well HbA 1c is an indicator of the patient's glycemic control. With knowledge of the mean glucose, an estimated HbA 1c (eA1C) can be calculated with the formula provided in this article to compare with the measured HbA 1c . Estimating glycemic control from HbA 1c alone is in essence applying a population average to an individual, which can be misleading. Thus, a patient's CGM glucose profile has considerable value for optimizing his or her diabetes management. In this era of personalized, precision medicine, there are few better examples with respect to the fallacy of applying a population average to a specific patient rather than using specific information about the patient to determine the optimal approach to treatment. © 2017 by the American Diabetes Association.

  10. Glucose-responsive hydrogel electrode for biocompatible glucose transistor

    NASA Astrophysics Data System (ADS)

    Kajisa, Taira; Sakata, Toshiya

    2017-12-01

    In this paper, we propose a highly sensitive and biocompatible glucose sensor using a semiconductor-based field effect transistor (FET) with a functionalized hydrogel. The principle of the FET device contributes to the easy detection of ionic charges with high sensitivity, and the hydrogel coated on the electrode enables the specific detection of glucose with biocompatibility. The copolymerized hydrogel on the Au gate electrode of the FET device is optimized by controlling the mixture ratio of biocompatible 2-hydroxyethylmethacrylate (HEMA) as the main monomer and vinylphenylboronic acid (VPBA) as a glucose-responsive monomer. The gate surface potential of the hydrogel FETs shifts in the negative direction with increasing glucose concentration from 10 μM to 40 mM, which results from the increase in the negative charges on the basis of the diol-binding of PBA derivatives with glucose molecules in the hydrogel. Moreover, the hydrogel coated on the gate suppresses the signal noise caused by the nonspecific adsorption of proteins such as albumin. The hydrogel FET can serve as a highly sensitive and biocompatible glucose sensor in in vivo or ex vivo applications such as eye contact lenses and sheets adhering to the skin.

  11. Proteins QSAR with Markov average electrostatic potentials.

    PubMed

    González-Díaz, Humberto; Uriarte, Eugenio

    2005-11-15

    Classic physicochemical and topological indices have been largely used in small molecules QSAR but less in proteins QSAR. In this study, a Markov model is used to calculate, for the first time, average electrostatic potentials xik for an indirect interaction between aminoacids placed at topologic distances k within a given protein backbone. The short-term average stochastic potential xi1 for 53 Arc repressor mutants was used to model the effect of Alanine scanning on thermal stability. The Arc repressor is a model protein of relevance for biochemical studies on bioorganics and medicinal chemistry. A linear discriminant analysis model developed correctly classified 43 out of 53, 81.1% of proteins according to their thermal stability. More specifically, the model classified 20/28, 71.4% of proteins with near wild-type stability and 23/25, 92.0% of proteins with reduced stability. Moreover, predictability in cross-validation procedures was of 81.0%. Expansion of the electrostatic potential in the series xi0, xi1, xi2, and xi3, justified the use of the abrupt truncation approach, being the overall accuracy >70.0% for xi0 but equal for xi1, xi2, and xi3. The xi1 model compared favorably with respect to others based on D-Fire potential, surface area, volume, partition coefficient, and molar refractivity, with less than 77.0% of accuracy [Ramos de Armas, R.; González-Díaz, H.; Molina, R.; Uriarte, E. Protein Struct. Func. Bioinf.2004, 56, 715]. The xi1 model also has more tractable interpretation than others based on Markovian negentropies and stochastic moments. Finally, the model is notably simpler than the two models based on quadratic and linear indices. Both models, reported by Marrero-Ponce et al., use four-to-five time more descriptors. Introduction of average stochastic potentials may be useful for QSAR applications; having xik amenable physical interpretation and being very effective.

  12. Baseline-dependent averaging in radio interferometry

    NASA Astrophysics Data System (ADS)

    Wijnholds, S. J.; Willis, A. G.; Salvini, S.

    2018-05-01

    This paper presents a detailed analysis of the applicability and benefits of baseline-dependent averaging (BDA) in modern radio interferometers and in particular the Square Kilometre Array. We demonstrate that BDA does not affect the information content of the data other than a well-defined decorrelation loss for which closed form expressions are readily available. We verify these theoretical findings using simulations. We therefore conclude that BDA can be used reliably in modern radio interferometry allowing a reduction of visibility data volume (and hence processing costs for handling visibility data) by more than 80 per cent.

  13. The averaging method in applied problems

    NASA Astrophysics Data System (ADS)

    Grebenikov, E. A.

    1986-04-01

    The totality of methods, allowing to research complicated non-linear oscillating systems, named in the literature "averaging method" has been given. THe author is describing the constructive part of this method, or a concrete form and corresponding algorithms, on mathematical models, sufficiently general , but built on concrete problems. The style of the book is that the reader interested in the Technics and algorithms of the asymptotic theory of the ordinary differential equations, could solve individually such problems. For specialists in the area of applied mathematics and mechanics.

  14. Average characteristics of partially coherent electromagnetic beams.

    PubMed

    Seshadri, S R

    2000-04-01

    Average characteristics of partially coherent electromagnetic beams are treated with the paraxial approximation. Azimuthally or radially polarized, azimuthally symmetric beams and linearly polarized dipolar beams are used as examples. The change in the mean squared width of the beam from its value at the location of the beam waist is found to be proportional to the square of the distance in the propagation direction. The proportionality constant is obtained in terms of the cross-spectral density as well as its spatial spectrum. The use of the cross-spectral density has advantages over the use of its spatial spectrum.

  15. Continuous Glucose Monitoring For Patients with Diabetes

    PubMed Central

    2011-01-01

    Executive Summary Objective To determine the effectiveness and cost-effectiveness of continuous glucose monitoring combined with self-monitoring of blood glucose compared with self-monitoring of blood glucose alone in the management of diabetes. Clinical Need: Condition and Target Population Diabetes is a chronic metabolic disorder that interferes with the body’s ability to produce or effectively use insulin. In 2005, an estimated 816,000 Ontarians had diabetes representing 8.8% of the province’s population. Type 1 or juvenile onset diabetes is a life-long disorder that commonly manifests in children and adolescents. It represents about 10% of the total diabetes population and involves immune-mediated destruction of insulin producing cells in the pancreas. The loss of these cells necessitates insulin therapy. Type 2 or “adult-onset” diabetes represents about 90% of the total diabetes population and is marked by a resistance to insulin or insufficient insulin secretion. The risk of developing type 2 diabetes increases with age, obesity and lack of physical activity. Approximately 30% of patients with type 2 diabetes eventually require insulin therapy. Technology Continuous glucose monitors (CGM) measure glucose levels in the interstitial fluid surrounding skin cells. These measurements supplement conventional self monitoring of blood glucose (SMBG) by monitoring the glucose fluctuations continuously over a stipulated period of time, thereby identifying fluctuations that would not be identified with SMBG alone. To use a CGM, a sensor is inserted under the skin to measure glucose in the interstitial fluid. The sensor is wired to a transmitter. The device requires calibration using a capillary blood glucose measurement. Each sensor continuously measures glucose every 5-10 seconds averaging these values every 5 minutes and storing this data in the monitors memory. Depending on the device used, the algorithm in the device can measure glucose over a 3 or 6 day

  16. Parents' Reactions to Finding Out That Their Children Have Average or above Average IQ Scores.

    ERIC Educational Resources Information Center

    Dirks, Jean; And Others

    1983-01-01

    Parents of 41 children who had been given an individually-administered intelligence test were contacted 19 months after testing. Parents of average IQ children were less accurate in their memory of test results. Children with above average IQ experienced extremely low frequencies of sibling rivalry, conceit or pressure. (Author/HLM)

  17. Average Temperatures in the Southwestern United States, 2000-2015 Versus Long-Term Average

    EPA Pesticide Factsheets

    This indicator shows how the average air temperature from 2000 to 2015 has differed from the long-term average (1895??2015). To provide more detailed information, each state has been divided into climate divisions, which are zones that share similar climate features. For more information: www.epa.gov/climatechange/science/indicators

  18. The Weighted-Average Lagged Ensemble.

    PubMed

    DelSole, T; Trenary, L; Tippett, M K

    2017-11-01

    A lagged ensemble is an ensemble of forecasts from the same model initialized at different times but verifying at the same time. The skill of a lagged ensemble mean can be improved by assigning weights to different forecasts in such a way as to maximize skill. If the forecasts are bias corrected, then an unbiased weighted lagged ensemble requires the weights to sum to one. Such a scheme is called a weighted-average lagged ensemble. In the limit of uncorrelated errors, the optimal weights are positive and decay monotonically with lead time, so that the least skillful forecasts have the least weight. In more realistic applications, the optimal weights do not always behave this way. This paper presents a series of analytic examples designed to illuminate conditions under which the weights of an optimal weighted-average lagged ensemble become negative or depend nonmonotonically on lead time. It is shown that negative weights are most likely to occur when the errors grow rapidly and are highly correlated across lead time. The weights are most likely to behave nonmonotonically when the mean square error is approximately constant over the range forecasts included in the lagged ensemble. An extreme example of the latter behavior is presented in which the optimal weights vanish everywhere except at the shortest and longest lead times.

  19. Detrending moving average algorithm for multifractals

    NASA Astrophysics Data System (ADS)

    Gu, Gao-Feng; Zhou, Wei-Xing

    2010-07-01

    The detrending moving average (DMA) algorithm is a widely used technique to quantify the long-term correlations of nonstationary time series and the long-range correlations of fractal surfaces, which contains a parameter θ determining the position of the detrending window. We develop multifractal detrending moving average (MFDMA) algorithms for the analysis of one-dimensional multifractal measures and higher-dimensional multifractals, which is a generalization of the DMA method. The performance of the one-dimensional and two-dimensional MFDMA methods is investigated using synthetic multifractal measures with analytical solutions for backward (θ=0) , centered (θ=0.5) , and forward (θ=1) detrending windows. We find that the estimated multifractal scaling exponent τ(q) and the singularity spectrum f(α) are in good agreement with the theoretical values. In addition, the backward MFDMA method has the best performance, which provides the most accurate estimates of the scaling exponents with lowest error bars, while the centered MFDMA method has the worse performance. It is found that the backward MFDMA algorithm also outperforms the multifractal detrended fluctuation analysis. The one-dimensional backward MFDMA method is applied to analyzing the time series of Shanghai Stock Exchange Composite Index and its multifractal nature is confirmed.

  20. Averaged null energy condition from causality

    DOE PAGES

    Hartman, Thomas; Kundu, Sandipan; Tajdini, Amirhossein

    2017-07-14

    Unitary, Lorentz-invariant quantum field theories in at spacetime obey mi-crocausality: commutators vanish at spacelike separation. For interacting theories in more than two dimensions, we show that this implies that the averaged null energy,more » $$\\int$$duT uu, must be non-negative. This non-local operator appears in the operator product expansion of local operators in the lightcone limit, and therefore contributes to n-point functions. We derive a sum rule that isolates this contribution and is manifestly positive. The argument also applies to certain higher spin operators other than the stress tensor, generating an infinite family of new constraints of the form RduX uuu∙∙∙u ≥ 0. These lead to new inequalities for the coupling constants of spinning operators in conformal field theory, which include as special cases (but are generally stronger than) the existing constraints from the lightcone bootstrap, deep inelastic scattering, conformal collider methods, and relative entropy. We also comment on the relation to the recent derivation of the averaged null energy condition from relative entropy, and suggest a more general connection between causality and information-theoretic inequalities in QFT.« less

  1. Global atmospheric circulation statistics: Four year averages

    NASA Technical Reports Server (NTRS)

    Wu, M. F.; Geller, M. A.; Nash, E. R.; Gelman, M. E.

    1987-01-01

    Four year averages of the monthly mean global structure of the general circulation of the atmosphere are presented in the form of latitude-altitude, time-altitude, and time-latitude cross sections. The numerical values are given in tables. Basic parameters utilized include daily global maps of temperature and geopotential height for 18 pressure levels between 1000 and 0.4 mb for the period December 1, 1978 through November 30, 1982 supplied by NOAA/NMC. Geopotential heights and geostrophic winds are constructed using hydrostatic and geostrophic formulae. Meridional and vertical velocities are calculated using thermodynamic and continuity equations. Fields presented in this report are zonally averaged temperature, zonal, meridional, and vertical winds, and amplitude of the planetary waves in geopotential height with zonal wave numbers 1-3. The northward fluxes of sensible heat and eastward momentum by the standing and transient eddies along with their wavenumber decomposition and Eliassen-Palm flux propagation vectors and divergences by the standing and transient eddies along with their wavenumber decomposition are also given. Large interhemispheric differences and year-to-year variations are found to originate in the changes in the planetary wave activity.

  2. Averaged null energy condition from causality

    NASA Astrophysics Data System (ADS)

    Hartman, Thomas; Kundu, Sandipan; Tajdini, Amirhossein

    2017-07-01

    Unitary, Lorentz-invariant quantum field theories in flat spacetime obey mi-crocausality: commutators vanish at spacelike separation. For interacting theories in more than two dimensions, we show that this implies that the averaged null energy, ∫ duT uu , must be non-negative. This non-local operator appears in the operator product expansion of local operators in the lightcone limit, and therefore contributes to n-point functions. We derive a sum rule that isolates this contribution and is manifestly positive. The argument also applies to certain higher spin operators other than the stress tensor, generating an infinite family of new constraints of the form ∫ duX uuu··· u ≥ 0. These lead to new inequalities for the coupling constants of spinning operators in conformal field theory, which include as special cases (but are generally stronger than) the existing constraints from the lightcone bootstrap, deep inelastic scattering, conformal collider methods, and relative entropy. We also comment on the relation to the recent derivation of the averaged null energy condition from relative entropy, and suggest a more general connection between causality and information-theoretic inequalities in QFT.

  3. Averaged null energy condition from causality

    SciTech Connect

    Hartman, Thomas; Kundu, Sandipan; Tajdini, Amirhossein

    Unitary, Lorentz-invariant quantum field theories in at spacetime obey mi-crocausality: commutators vanish at spacelike separation. For interacting theories in more than two dimensions, we show that this implies that the averaged null energy,more » $$\\int$$duT uu, must be non-negative. This non-local operator appears in the operator product expansion of local operators in the lightcone limit, and therefore contributes to n-point functions. We derive a sum rule that isolates this contribution and is manifestly positive. The argument also applies to certain higher spin operators other than the stress tensor, generating an infinite family of new constraints of the form RduX uuu∙∙∙u ≥ 0. These lead to new inequalities for the coupling constants of spinning operators in conformal field theory, which include as special cases (but are generally stronger than) the existing constraints from the lightcone bootstrap, deep inelastic scattering, conformal collider methods, and relative entropy. We also comment on the relation to the recent derivation of the averaged null energy condition from relative entropy, and suggest a more general connection between causality and information-theoretic inequalities in QFT.« less

  4. Glucose Metabolism After Renal Transplantation

    PubMed Central

    Hecking, Manfred; Kainz, Alexander; Werzowa, Johannes; Haidinger, Michael; Döller, Dominik; Tura, Andrea; Karaboyas, Angelo; Hörl, Walter H.; Wolzt, Michael; Sharif, Adnan; Roden, Michael; Moro, Ermanno; Pacini, Giovanni; Port, Friedrich K.; Säemann, Marcus D.

    2013-01-01

    OBJECTIVE We determined prevalence, risk factors, phenotype, and pathophysiological mechanism of new-onset diabetes after transplantation (NODAT) to generate strategies for optimal pharmacological management of hyperglycemia in NODAT patients. RESEARCH DESIGN AND METHODS Retrospective cohort study comparing demographics, laboratory data, and oral glucose tolerance test (OGTT)-derived metabolic parameters from kidney transplant recipients versus subjects not receiving transplants. RESULTS Among 1,064 stable kidney transplant recipients (≥6 months posttransplantation), 113 (11%) had a history of NODAT and 132 (12%) had pretransplant diabetes. In the remaining patients, randomly assigned OGTTs showed a high prevalence of abnormal glucose metabolism (11% diabetes; 32% impaired fasting glucose, impaired glucose tolerance, or both), predominantly in older patients who received tacrolimus as the primary immunosuppressant. Compared with 1,357 nontransplant subjects, stable kidney transplant recipients had lower basal glucose, higher glycated hemoglobin, lower insulin secretion, and greater insulin sensitivity in each of the three subgroups, defined by OGTT 2-h glucose (<140, 140–199, ≥200 mg/dL). These findings were reinforced in linear spline interpolation models of insulin secretion and sensitivity (all P < 0.001) and in another regression model in which the estimated oral glucose insulin sensitivity index was substantially higher (by 79–112 mL/min m2) for transplant versus nontransplant subjects despite adjustments for age, sex, and BMI (all P < 0.001). CONCLUSIONS Glucose metabolism differs substantially between kidney transplant recipients and nontransplant controls. Because impaired insulin secretion appears to be the predominant pathophysiological feature after renal transplantation, early therapeutic interventions that preserve, maintain, or improve β-cell function are potentially beneficial in this population. PMID:23656979

  5. Lagrangian averaging, nonlinear waves, and shock regularization

    NASA Astrophysics Data System (ADS)

    Bhat, Harish S.

    In this thesis, we explore various models for the flow of a compressible fluid as well as model equations for shock formation, one of the main features of compressible fluid flows. We begin by reviewing the variational structure of compressible fluid mechanics. We derive the barotropic compressible Euler equations from a variational principle in both material and spatial frames. Writing the resulting equations of motion requires certain Lie-algebraic calculations that we carry out in detail for expository purposes. Next, we extend the derivation of the Lagrangian averaged Euler (LAE-alpha) equations to the case of barotropic compressible flows. The derivation in this thesis involves averaging over a tube of trajectories etaepsilon centered around a given Lagrangian flow eta. With this tube framework, the LAE-alpha equations are derived by following a simple procedure: start with a given action, expand via Taylor series in terms of small-scale fluid fluctuations xi, truncate, average, and then model those terms that are nonlinear functions of xi. We then analyze a one-dimensional subcase of the general models derived above. We prove the existence of a large family of traveling wave solutions. Computing the dispersion relation for this model, we find it is nonlinear, implying that the equation is dispersive. We carry out numerical experiments that show that the model possesses smooth, bounded solutions that display interesting pattern formation. Finally, we examine a Hamiltonian partial differential equation (PDE) that regularizes the inviscid Burgers equation without the addition of standard viscosity. Here alpha is a small parameter that controls a nonlinear smoothing term that we have added to the inviscid Burgers equation. We show the existence of a large family of traveling front solutions. We analyze the initial-value problem and prove well-posedness for a certain class of initial data. We prove that in the zero-alpha limit, without any standard viscosity

  6. Asymmetric network connectivity using weighted harmonic averages

    NASA Astrophysics Data System (ADS)

    Morrison, Greg; Mahadevan, L.

    2011-02-01

    We propose a non-metric measure of the "closeness" felt between two nodes in an undirected, weighted graph using a simple weighted harmonic average of connectivity, that is a real-valued Generalized Erdös Number (GEN). While our measure is developed with a collaborative network in mind, the approach can be of use in a variety of artificial and real-world networks. We are able to distinguish between network topologies that standard distance metrics view as identical, and use our measure to study some simple analytically tractable networks. We show how this might be used to look at asymmetry in authorship networks such as those that inspired the integer Erdös numbers in mathematical coauthorships. We also show the utility of our approach to devise a ratings scheme that we apply to the data from the NetFlix prize, and find a significant improvement using our method over a baseline.

  7. FEL system with homogeneous average output

    DOEpatents

    Douglas, David R.; Legg, Robert; Whitney, R. Roy; Neil, George; Powers, Thomas Joseph

    2018-01-16

    A method of varying the output of a free electron laser (FEL) on very short time scales to produce a slightly broader, but smooth, time-averaged wavelength spectrum. The method includes injecting into an accelerator a sequence of bunch trains at phase offsets from crest. Accelerating the particles to full energy to result in distinct and independently controlled, by the choice of phase offset, phase-energy correlations or chirps on each bunch train. The earlier trains will be more strongly chirped, the later trains less chirped. For an energy recovered linac (ERL), the beam may be recirculated using a transport system with linear and nonlinear momentum compactions M.sub.56, which are selected to compress all three bunch trains at the FEL with higher order terms managed.

  8. [Quetelet, the average man and medical knowledge].

    PubMed

    Caponi, Sandra

    2013-01-01

    Using two books by Adolphe Quetelet, I analyze his theory of the 'average man', which associates biological and social normality with the frequency with which certain characteristics appear in a population. The books are Sur l'homme et le développement de ses facultés and Du systeme social et des lois qui le régissent. Both reveal that Quetelet's ideas are permeated by explanatory strategies drawn from physics and astronomy, and also by discursive strategies drawn from theology and religion. The stability of the mean as opposed to the dispersion of individual characteristics and events provided the basis for the use of statistics in social sciences and medicine.

  9. Quetelet, the average man and medical knowledge.

    PubMed

    Caponi, Sandra

    2013-01-01

    Using two books by Adolphe Quetelet, I analyze his theory of the 'average man', which associates biological and social normality with the frequency with which certain characteristics appear in a population. The books are Sur l'homme et le développement de ses facultés and Du systeme social et des lois qui le régissent. Both reveal that Quetelet's ideas are permeated by explanatory strategies drawn from physics and astronomy, and also by discursive strategies drawn from theology and religion. The stability of the mean as opposed to the dispersion of individual characteristics and events provided the basis for the use of statistics in social sciences and medicine.

  10. Frequentist Model Averaging in Structural Equation Modelling.

    PubMed

    Jin, Shaobo; Ankargren, Sebastian

    2018-06-04

    Model selection from a set of candidate models plays an important role in many structural equation modelling applications. However, traditional model selection methods introduce extra randomness that is not accounted for by post-model selection inference. In the current study, we propose a model averaging technique within the frequentist statistical framework. Instead of selecting an optimal model, the contributions of all candidate models are acknowledged. Valid confidence intervals and a [Formula: see text] test statistic are proposed. A simulation study shows that the proposed method is able to produce a robust mean-squared error, a better coverage probability, and a better goodness-of-fit test compared to model selection. It is an interesting compromise between model selection and the full model.

  11. Comprehensive time average digital holographic vibrometry

    NASA Astrophysics Data System (ADS)

    Psota, Pavel; Lédl, Vít; Doleček, Roman; Mokrý, Pavel; Vojtíšek, Petr; Václavík, Jan

    2016-12-01

    This paper presents a method that simultaneously deals with drawbacks of time-average digital holography: limited measurement range, limited spatial resolution, and quantitative analysis of the measured Bessel fringe patterns. When the frequency of the reference wave is shifted by an integer multiple of frequency at which the object oscillates, the measurement range of the method can be shifted either to smaller or to larger vibration amplitudes. In addition, phase modulation of the reference wave is used to obtain a sequence of phase-modulated fringe patterns. Such fringe patterns can be combined by means of phase-shifting algorithms, and amplitudes of vibrations can be straightforwardly computed. This approach independently calculates the amplitude values in every single pixel. The frequency shift and phase modulation are realized by proper control of Bragg cells and therefore no additional hardware is required.

  12. The balanced survivor average causal effect.

    PubMed

    Greene, Tom; Joffe, Marshall; Hu, Bo; Li, Liang; Boucher, Ken

    2013-05-07

    Statistical analysis of longitudinal outcomes is often complicated by the absence of observable values in patients who die prior to their scheduled measurement. In such cases, the longitudinal data are said to be "truncated by death" to emphasize that the longitudinal measurements are not simply missing, but are undefined after death. Recently, the truncation by death problem has been investigated using the framework of principal stratification to define the target estimand as the survivor average causal effect (SACE), which in the context of a two-group randomized clinical trial is the mean difference in the longitudinal outcome between the treatment and control groups for the principal stratum of always-survivors. The SACE is not identified without untestable assumptions. These assumptions have often been formulated in terms of a monotonicity constraint requiring that the treatment does not reduce survival in any patient, in conjunction with assumed values for mean differences in the longitudinal outcome between certain principal strata. In this paper, we introduce an alternative estimand, the balanced-SACE, which is defined as the average causal effect on the longitudinal outcome in a particular subset of the always-survivors that is balanced with respect to the potential survival times under the treatment and control. We propose a simple estimator of the balanced-SACE that compares the longitudinal outcomes between equivalent fractions of the longest surviving patients between the treatment and control groups and does not require a monotonicity assumption. We provide expressions for the large sample bias of the estimator, along with sensitivity analyses and strategies to minimize this bias. We consider statistical inference under a bootstrap resampling procedure.

  13. Continuous glucose monitoring, oral glucose tolerance, and insulin - glucose parameters in adolescents with simple obesity.

    PubMed

    El Awwa, A; Soliman, A; Al-Ali, M; Yassin, M; De Sanctis, V

    2012-09-01

    In obese adolescents pancreatic beta-cells may not be able to cope with insulin resistance leading to hyperglycemia and type2 diabetes (T2DM To assess oral glucose tolerance, 72-h continuous blood glucose concentrations (CGM) and calculate homeostatic model assessment (HOMA), and the quantitative insulin sensitivity check index (QUICKI) in 13 adolescents with simple obesity (BMI SDS=4 ± 1.06). OGTT performed in 13 obese adolescents (13.47 ± 3 years) revealed 3 cases (23%) with impaired fasting glucose (IFG: fasting glucose >5.6 mmol/L), 4 cases (30%) with impaired glucose tolerance (IGT: 2h blood glucose >7.8 <11.1 mmol/L), and none with diabetes. Using the continuous glucose monitoring system ( CGMS), IFG was detected in 4 cases, the maximum serum blood glucose (BG : 2h or more after meal) was >7.8 and <11.1 mmol/L (IGT) in 9 children (69%) and >11.1 mmol/L (diabetes) in one case (7.6%). Five cases had a minimum BG recorded of <2.7 mmol/L (hypoglycemia). No glycemic abnormality was detected using HbA1C (5.7 ± 0.3%). 11/13 patients had HOMA values >2.6 and QUICKI values <0.35 denoting insulin resistance. Beta cell mass percent (B %) = 200 ± 94.8% and insulin sensitivity values (IS)=50.4 ± 45.5% denoted insulin resistance with hyper-insulinaemia and preserved beta cell mass. In obese adolescents, CGMS is superior to OGTT and HbA1C in detecting glycemic abnormalities, which appears to be secondary to insulin resistance.

  14. Improved glucose tolerance four hours after taking guar with glucose.

    PubMed

    Jenkins, D J; Wolever, T M; Nineham, R; Sarson, D L; Bloom, S R; Ahern, J; Alberti, K G; Hockaday, T D

    1980-07-01

    To gain some insights about the possible cumulative metabolic effect after a high-fibre meal, 6 subjects took two 80 g oral glucose loads, 4 h apart. Addition of 22.3 g guar to the first load decreased the rise in blood glucose and insulin after the second (guar-free) load by 50% (p less than 0.002) and 31% (p less than 0.02) respectively. This corresponded with decreased 3-hydroxybutyrate levels at the start of the glucose tolerance test after guar (by 20%, p less than 0.02). When no guar was added to the first glucose load, both 3-hydroxybutyrate and non-esterified fatty acids tended to rise before the second test. No significant effect was seen in the responses of the gut hormones, gastric inhibitory peptide and enteroglucagon. Spreading the intake of the first 80 g of glucose over the initial 4 h (2 subjects) similarly flattened the glycaemic but increased the insulin response. The effect of guar on carbohydrate and fat metabolism, therefore, lasts at least 4 h and may result in improved carbohydrate tolerance to subsequent guar-free meals.

  15. Glucose Monitoring in Individuals With Diabetes Using a Long-Term Implanted Sensor/Telemetry System and Model.

    PubMed

    Lucisano, Joseph Y; Routh, Timothy L; Lin, Joe T; Gough, David A

    2017-09-01

    The use of a fully implanted first-generation prototype sensor/telemetry system is described for long-term monitoring of subcutaneous tissue glucose in a small cohort of people with diabetes. Sensors are based on a membrane containing immobilized glucose oxidase and catalase coupled to oxygen electrodes and a telemetry system, integrated as an implant. The devices remained implanted for up to 180 days, with signals transmitted every 2 min to external receivers. The data include signal recordings from glucose clamps and spontaneous glucose excursions, matched, respectively, to reference blood glucose and finger-stick values. The sensor signals indicate dynamic tissue glucose, for which there is no independent standard, and a model describing the relationship between blood glucose and the signal is, therefore, included. The values of all model parameters have been estimated, including the permeability of adjacent tissues to glucose, and equated to conventional mass transfer parameters. As a group, the sensor calibration varied randomly at an average rate of -2.6%/week. Statistical correlation indicated strong association between the sensor signals and reference glucose values. Continuous long-term glucose monitoring in individuals with diabetes is feasible with this system. All therapies for diabetes are based on glucose control, and therefore, require glucose monitoring. This fully implanted long-term sensor/telemetry system may facilitate a new era of management of the disease.

  16. Glucose Monitoring in Individuals with Diabetes using a Long-Term Implanted Sensor/Telemetry System and Model

    PubMed Central

    Lucisano, Joseph Y.; Routh, Timothy L.; Lin, Joe T.; Gough, David A.

    2017-01-01

    Objective The use of a fully implanted, first-generation prototype sensor/telemetry system is described for long-term monitoring of subcutaneous tissue glucose in a small cohort of people with diabetes. Methods Sensors are based on a membrane containing immobilized glucose oxidase and catalase coupled to oxygen electrodes and a telemetry system, integrated as an implant. The devices remained implanted for up to 180 days, with signals transmitted every 2 minutes to external receivers. Results The data include signal recordings from glucose clamps and spontaneous glucose excursions, matched respectively to reference blood glucose and finger-stick values. The sensor signals indicate dynamic tissue glucose, for which there is no independent standard, and a model describing the relationship between blood glucose and the signal is therefore included. The values of all model parameters have been estimated, including the permeability of adjacent tissues to glucose, and equated to conventional mass transfer parameters. As a group, the sensor calibration varied randomly at an average rate of −2.6%/week. Statistical correlation indicated strong association between the sensor signals and reference glucose values. Conclusions Continuous, long-term glucose monitoring in individuals with diabetes is feasible with this system. Significance All therapies for diabetes are based on glucose control and therefore require glucose monitoring. This fully implanted, long-term sensor/telemetry system may facilitate a new era of management of the disease. PMID:27775510

  17. Current concepts in blood glucose monitoring

    PubMed Central

    Khadilkar, Kranti Shreesh; Bandgar, Tushar; Shivane, Vyankatesh; Lila, Anurag; Shah, Nalini

    2013-01-01

    Blood glucose monitoring has evolved over the last century. The concept of adequate glycemic control and minimum glycemic variability requires an ideal, accurate and reliable glucose monitoring system. The search for an ideal blood glucose monitoring system still continues. This review explains the various blood glucose monitoring systems with special focus on the monitoring systems like self- monitored blood glucose (SMBG) and continuous glucose monitoring system (CGMS). It also focuses on the newer concepts of blood glucose monitoring and their incorporation in routine clinical management of diabetes mellitus. PMID:24910827

  18. Effect of physical training on the oxidation of an oral glucose load at rest: a naturally labeled 13C-glucose study.

    PubMed

    Krzentowski, G; Pirnay, F; Luyckx, A S; Lacroix, M; Mosora, F; Lefebvre, P J

    1983-01-01

    This study aimed at investigating, in six healthy, non obese, young (25 +/- 1 years) male volunteers, with strictly normal oral glucose tolerance, the influence of a six week physical training period (60 min bicycling 5 days/week at 30-40% of their individual VO2 max) on the hormonal and metabolic response to a 100 g oral 13C-naturally labeled glucose load given at rest before and 36 h after the last training session. Exogenous glucose oxidation was derived from 13CO2 measurements on expired air. Training resulted in: a 29% increase in VO2 max (2 p less than 0.002), a 27% decrease in plasma triglycerides (2 p less than 0.02). No changes were observed concerning weight, total body K, skinfold tolerance, which was strictly normal before training, remained unchanged, but the insulin response to the oral glucose load decreased by 24% (2 p less than 0.025). Exogenous glucose oxidation was similar before and after training, averaging 35.9 +/- 2.1 and 37.4 +/- 2.0 g/7 h respectively. a 6 week training period, performed on strictly healthy young males, studied at rest, induced an increase in VO2 max, a decrease in plasma triglycerides and a lower insulin response to oral glucose while glucose tolerance and exogenous glucose oxidation remained unchanged.

  19. Movie denoising by average of warped lines.

    PubMed

    Bertalmío, Marcelo; Caselles, Vicent; Pardo, Alvaro

    2007-09-01

    Here, we present an efficient method for movie denoising that does not require any motion estimation. The method is based on the well-known fact that averaging several realizations of a random variable reduces the variance. For each pixel to be denoised, we look for close similar samples along the level surface passing through it. With these similar samples, we estimate the denoised pixel. The method to find close similar samples is done via warping lines in spatiotemporal neighborhoods. For that end, we present an algorithm based on a method for epipolar line matching in stereo pairs which has per-line complexity O (N), where N is the number of columns in the image. In this way, when applied to the image sequence, our algorithm is computationally efficient, having a complexity of the order of the total number of pixels. Furthermore, we show that the presented method is unsupervised and is adapted to denoise image sequences with an additive white noise while respecting the visual details on the movie frames. We have also experimented with other types of noise with satisfactory results.

  20. Global Average Brightness Temperature for April 2003

    NASA Image and Video Library

    2003-06-02

    This image shows average temperatures in April, 2003, observed by AIRS at an infrared wavelength that senses either the Earth's surface or any intervening cloud. Similar to a photograph of the planet taken with the camera shutter held open for a month, stationary features are captured while those obscured by moving clouds are blurred. Many continental features stand out boldly, such as our planet's vast deserts, and India, now at the end of its long, clear dry season. Also obvious are the high, cold Tibetan plateau to the north of India, and the mountains of North America. The band of yellow encircling the planet's equator is the Intertropical Convergence Zone (ITCZ), a region of persistent thunderstorms and associated high, cold clouds. The ITCZ merges with the monsoon systems of Africa and South America. Higher latitudes are increasingly obscured by clouds, though some features like the Great Lakes, the British Isles and Korea are apparent. The highest latitudes of Europe and Eurasia are completely obscured by clouds, while Antarctica stands out cold and clear at the bottom of the image. http://photojournal.jpl.nasa.gov/catalog/PIA00427

  1. Geographic Gossip: Efficient Averaging for Sensor Networks

    NASA Astrophysics Data System (ADS)

    Dimakis, Alexandros D. G.; Sarwate, Anand D.; Wainwright, Martin J.

    Gossip algorithms for distributed computation are attractive due to their simplicity, distributed nature, and robustness in noisy and uncertain environments. However, using standard gossip algorithms can lead to a significant waste in energy by repeatedly recirculating redundant information. For realistic sensor network model topologies like grids and random geometric graphs, the inefficiency of gossip schemes is related to the slow mixing times of random walks on the communication graph. We propose and analyze an alternative gossiping scheme that exploits geographic information. By utilizing geographic routing combined with a simple resampling method, we demonstrate substantial gains over previously proposed gossip protocols. For regular graphs such as the ring or grid, our algorithm improves standard gossip by factors of $n$ and $\\sqrt{n}$ respectively. For the more challenging case of random geometric graphs, our algorithm computes the true average to accuracy $\\epsilon$ using $O(\\frac{n^{1.5}}{\\sqrt{\\log n}} \\log \\epsilon^{-1})$ radio transmissions, which yields a $\\sqrt{\\frac{n}{\\log n}}$ factor improvement over standard gossip algorithms. We illustrate these theoretical results with experimental comparisons between our algorithm and standard methods as applied to various classes of random fields.

  2. Calculating Free Energies Using Average Force

    NASA Technical Reports Server (NTRS)

    Darve, Eric; Pohorille, Andrew; DeVincenzi, Donald L. (Technical Monitor)

    2001-01-01

    A new, general formula that connects the derivatives of the free energy along the selected, generalized coordinates of the system with the instantaneous force acting on these coordinates is derived. The instantaneous force is defined as the force acting on the coordinate of interest so that when it is subtracted from the equations of motion the acceleration along this coordinate is zero. The formula applies to simulations in which the selected coordinates are either unconstrained or constrained to fixed values. It is shown that in the latter case the formula reduces to the expression previously derived by den Otter and Briels. If simulations are carried out without constraining the coordinates of interest, the formula leads to a new method for calculating the free energy changes along these coordinates. This method is tested in two examples - rotation around the C-C bond of 1,2-dichloroethane immersed in water and transfer of fluoromethane across the water-hexane interface. The calculated free energies are compared with those obtained by two commonly used methods. One of them relies on determining the probability density function of finding the system at different values of the selected coordinate and the other requires calculating the average force at discrete locations along this coordinate in a series of constrained simulations. The free energies calculated by these three methods are in excellent agreement. The relative advantages of each method are discussed.

  3. Average oxidation state of carbon in proteins

    PubMed Central

    Dick, Jeffrey M.

    2014-01-01

    The formal oxidation state of carbon atoms in organic molecules depends on the covalent structure. In proteins, the average oxidation state of carbon (ZC) can be calculated as an elemental ratio from the chemical formula. To investigate oxidation–reduction (redox) patterns, groups of proteins from different subcellular locations and phylogenetic groups were selected for comparison. Extracellular proteins of yeast have a relatively high oxidation state of carbon, corresponding with oxidizing conditions outside of the cell. However, an inverse relationship between ZC and redox potential occurs between the endoplasmic reticulum and cytoplasm. This trend provides support for the hypothesis that protein transport and turnover are ultimately coupled to the maintenance of different glutathione redox potentials in subcellular compartments. There are broad changes in ZC in whole-genome protein compositions in microbes from different environments, and in Rubisco homologues, lower ZC tends to occur in organisms with higher optimal growth temperature. Energetic costs calculated from thermodynamic models are consistent with the notion that thermophilic organisms exhibit molecular adaptation to not only high temperature but also the reducing nature of many hydrothermal fluids. Further characterization of the material requirements of protein metabolism in terms of the chemical conditions of cells and environments may help to reveal other linkages among biochemical processes with implications for changes on evolutionary time scales. PMID:25165594

  4. The research of differential reference electrode arrayed flexible IGZO glucose biosensor based on microfluidic framework

    NASA Astrophysics Data System (ADS)

    Chen, Jian-Syun; Chou, Jung-Chuan; Liao, Yi-Hung; Chen, Ruei-Ting; Huang, Min-Siang; Wu, Tong-Yu

    2017-03-01

    This study used a fast, simple, and low-cost method to fabricate arrayed flexible glucose biosensor, and the glucose biosensor was integrated with microfluidic framework for investigating sensing characteristics of glucose biosensor at the dynamic conditions. The indium gallium zinc oxide (IGZO) was adopted as sensing membrane and it was deposited on aluminum electrodes / polyethylene terephthalate (PET) substrate by the radio frequency sputtering system. Then, we utilized screen-printed technology to accomplish miniaturization of glucose biosensor. Finally, the glucose sensing membrane was composed of glucose oxidase (GOx) and nafion, which was dropped on IGZO sensing membrane to complete glucose biosensor. According to the experimental results, we found that optimal sensing characteristics of arrayed flexible IGZO glucose biosensor at the dynamic conditions were better than at the static conditions. The optimal average sensitivity and linearity of the arrayed flexible IGZO glucose biosensor were 7.255 mV/mM and 0.994 at 20 µL/min flow rate, respectively.

  5. Localized 1H NMR measurement of glucose consumption in the human brain during visual stimulation.

    PubMed Central

    Chen, W; Novotny, E J; Zhu, X H; Rothman, D L; Shulman, R G

    1993-01-01

    Spatially localized 1H NMR spectroscopy has been applied to measure changes in brain glucose concentration during 8-Hz photic stimulation. NMR spectroscopic measurements were made in a 12-cm3 volume centered on the calcarine fissure and encompassing the primary visual cortex. The average maximum change in glucose levels was 0.34 mumol.g-1 (n = 5) at 15 min; glucose level had turned toward resting level at 25 min. The glucose change was used to calculate the increase of glucose cerebral metabolic rate in the visual cortex region for individual subjects by using the Michaelis-Menten model of glucose transport on the assumption of constant transport kinetics. The glucose cerebral metabolic rate was calculated to increase over the nonstimulated rate by 22% during the first 15 min of photic stimulation. A model in which the glucose metabolic rate gradually decreases during stimulation was proposed as a possible explanation for the recovery of brain glucose and previously measured lactate concentrations to prestimulus values after 15 min. Images Fig. 1 PMID:8234332

  6. Performance of a continuous glucose monitoring system during controlled hypoglycaemia in healthy volunteers.

    PubMed

    Cheyne, E H; Cavan, D A; Kerr, D

    2002-01-01

    It has been suggested that the continuous glucose monitoring system may be a useful tool for detecting unrecognised hypoglycaemia, especially at times when finger prick testing is difficult or impossible (e.g., at night). Studies suggest that subcutaneous glucose levels closely mimic blood glucose levels with a lag time of only a few minutes. However, no studies have been published to show how well the sensor performs during sustained or in recovery from hypoglycaemia. This study involved using a hyperinsulinaemic glucose clamp (60 mU/m2) in nine healthy volunteers. Each subject had two sensors inserted the day before the study. Blood glucose levels were maintained at euglycaemia for the first 60 min, then decreased to 45 mg/dL (2.5 mmol/L) for 60 min, and finally restored to euglycaemia. Blood glucose measurements were compared with interstitial values recorded by the sensor. Sensor profiles showed acceptable agreement with blood glucose levels at each of the three plateaus with a correlation coefficient of 0.79, slope of 0.85, and mean absolute error of 7%. The sensor drop closely matched the drop in blood glucose, but the recovery from hypoglycaemia was delayed by an average of 26 min. Continuous glucose sensing provides a useful means of detecting unrecognised hypoglycaemia in type 1 diabetes, although the duration of hypoglycaemia may be overestimated.

  7. Abnormal oral glucose tolerance and glucose malabsorption after vagotomy and pyloroplasty. A tracer method for measuring glucose absorption rates

    SciTech Connect

    Radziuk, J.; Bondy, D.C.

    1982-11-01

    The mechanisms underlying the abnormal glucose tolerance in patients who had undergone vagotomy and pyloroplasty were investigated by measuring the rates of absorption of ingested glucose and the clearance rate of glucose using tracer methods. These methods are based on labeling a 100-g oral glucose load with (1-/sup 14/C)glucose and measuring glucose clearance using plasma levels of infused (3-/sup 3/H)glucose. The rate of appearance of both ingested and total glucose is then calculated continuously using a two-compartment model of glucose kinetics. It was found that about 30% of the ingested glucose (100 g) failed to appear in the systemic circulation.more » That this was due to malabsorption was confirmed using breath-hydrogen analysis. The absorption period is short (101 +/- 11 min) compared with normal values but the clearance of glucose is identical to that in control subjects, and it peaks 132 +/- 7 min after glucose loading. The peak plasma insulin values were more than four times higher in patients than in normal subjects, and this may afford an explanation of rates of glucose clearance that are inappropriate for the short absorption period. The combination of glucose malabsorption and this clearance pattern could yield the hypoglycemia that may be observed in patients after gastric surgery.« less

  8. Global Average Brightness Temperature for April 2003

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site] Figure 1

    This image shows average temperatures in April, 2003, observed by AIRS at an infrared wavelength that senses either the Earth's surface or any intervening cloud. Similar to a photograph of the planet taken with the camera shutter held open for a month, stationary features are captured while those obscured by moving clouds are blurred. Many continental features stand out boldly, such as our planet's vast deserts, and India, now at the end of its long, clear dry season. Also obvious are the high, cold Tibetan plateau to the north of India, and the mountains of North America. The band of yellow encircling the planet's equator is the Intertropical Convergence Zone (ITCZ), a region of persistent thunderstorms and associated high, cold clouds. The ITCZ merges with the monsoon systems of Africa and South America. Higher latitudes are increasingly obscured by clouds, though some features like the Great Lakes, the British Isles and Korea are apparent. The highest latitudes of Europe and Eurasia are completely obscured by clouds, while Antarctica stands out cold and clear at the bottom of the image.

    The Atmospheric Infrared Sounder Experiment, with its visible, infrared, and microwave detectors, provides a three-dimensional look at Earth's weather. Working in tandem, the three instruments can make simultaneous observations all the way down to the Earth's surface, even in the presence of heavy clouds. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global, 3-D map of atmospheric temperature and humidity and provides information on clouds, greenhouse gases, and many other atmospheric phenomena. The AIRS Infrared Sounder Experiment flies onboard NASA's Aqua spacecraft and is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., under contract to NASA. JPL is a division of the California Institute of Technology in Pasadena.

  9. Calibration in dogs of a subcutaneous miniaturized glucose sensor using a glucose meter for blood glucose determination.

    PubMed

    Poitout, V; Moatti-Sirat, D; Reach, G

    1992-01-01

    The feasibility of calibrating a glucose sensor by using a wearable glucose meter for blood glucose determination and moderate variations of blood glucose concentration was assessed. Six miniaturized glucose sensors were implanted in the subcutaneous tissue of conscious dogs, and the parameters used for the in vivo calibration of the sensor (sensitivity coefficient and extrapolated current in the absence of glucose) were determined from values of blood glucose and sensor response obtained during glucose infusion. (1) Venous plasma glucose level and venous total blood glucose level were measured simultaneously on the same sample, using a Beckman analyser and a Glucometer II, respectively. The regression between plasma glucose (x) and whole blood glucose (y) was y = 1.12x-0.08 mM (n = 114 values, r = 0.96, p = 0.0001). The error grid analysis indicated that the use of a Glucometer II for blood glucose determination was appropriate in dogs. (2) The in vivo sensitivity coefficients were 0.57 +/- 0.11 nA mM-1 when determined from plasma glucose, and 0.51 +/- 0.07 nA mM-1 when determined from whole blood glucose (t = 1.53, p = 0.18, n.s.). The background currents were 0.88 +/- 0.57 nA when determined from plasma glucose, and 0.63 +/- 0.77 nA when determined from whole blood glucose (t = 0.82, p = 0.45, n.s.). (3) The regression equation of the estimation of the subcutaneous glucose level obtained from the two methods was y = 1.04x + 0.56 mM (n = 171 values, r = 0.98, p = 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

  10. Glucose oxidation positively regulates glucose uptake and improves cardiac function recovery after myocardial reperfusion.

    PubMed

    Li, Tingting; Xu, Jie; Qin, Xinghua; Hou, Zuoxu; Guo, Yongzheng; Liu, Zhenhua; Wu, Jianjiang; Zheng, Hong; Zhang, Xing; Gao, Feng

    2017-11-01

    Myocardial reperfusion decreases glucose oxidation and uncouples glucose oxidation from glycolysis. Therapies that increase glucose oxidation lessen myocardial ischemia-reperfusion (I/R) injury. However, the regulation of glucose uptake during reperfusion remains poorly understood. We found that glucose uptake was remarkably diminished in the myocardium following reperfusion in Sprague-Dawley rats as detected by 18 F-labeled and fluorescent-labeled glucose analogs, even though GLUT1 was upregulated by threefold and GLUT4 translocation remained unchanged compared with those of sham-treated rats. The decreased glucose uptake was accompanied by suppressed glucose oxidation. Interestingly, stimulating glucose oxidation by inhibition of pyruvate dehydrogenase kinase 4 (PDK4), a rate-limiting enzyme for glucose oxidation, increased glucose uptake and alleviated I/R injury. In vitro data in neonatal myocytes showed that PDK4 overexpression decreased glucose uptake, whereas its knockdown increased glucose uptake, suggesting that PDK4 has a role in regulating glucose uptake. Moreover, inhibition of PDK4 increased myocardial glucose uptake with concomitant enhancement of cardiac insulin sensitivity following myocardial I/R. These results showed that the suppressed glucose oxidation mediated by PDK4 contributes to the reduced glucose uptake in the myocardium following reperfusion, and enhancement of glucose uptake exerts cardioprotection. The findings suggest that stimulating glucose oxidation via PDK4 could be an efficient approach to improve recovery from myocardial I/R injury. Copyright © 2017 the American Physiological Society.

  11. Nanosensor for detection of glucose

    NASA Astrophysics Data System (ADS)

    Del Villar, Ignacio; Matias, Ignacio R.; Arregui, Francisco J.

    2004-06-01

    A novel fiber-optic sensor sensitive to glucose has been designed based on electrostatic self-assembly method. The polycation of the structure is a mixture of poly(allylamine hydrochloride) (PAH) and Prussian Blue, whereas the polyanion is well-known enzyme gluocose oxidase (GOx). The range of glucose concentration that can be measured is submilimolar and is located between 0.1 and 2 mM. Measures are based on a new detection scheme based on the slope of the change of signal produced by injection of glucose, yielding to a linear response. The sensor responses in a PH range between 4 and 7.4, which includes the physiological PH of blood. Some rules for esitmation of the refractive index of the material deposited and the thickness of bilayers are also given.

  12. Prognostic value of low blood glucose at the presentation of E. coli bacteremia.

    PubMed

    Alamgir, Shamsuddin; Volkova, Natalia B; Peterson, Michael W

    2006-11-01

    Septicemia is the tenth leading cause of death in the United States, and Escherichia coli is the most common isolate in blood cultures. Low blood glucose is a known complication of sepsis. The prognostic role of low blood glucose in E. coli bacteremia is unknown. The study's objective was to identify the incidence of low blood glucose at the presentation of E. coli bacteremia and determine its influence on prognosis and outcome. A retrospective cohort study was conducted in university-affiliated community hospitals. Subjects were consecutive patients diagnosed with E. coli bacteremia between 1997 and 2003. We identified 1060 patients with documented E. coli bacteremia. We excluded 105 patients who were younger than 18 years old or pregnant. We recorded demographic characteristics, discharge diagnosis, and outcome. Among the 955 patients with E. coli bacteremia, the average age was 64+/-19.4 years. Overall, 4.6% had documented low blood glucose (blood glucose <70 mg/dL) at presentation. The incidence of low blood glucose was the same in diabetic and nondiabetic patients. Patients with low blood glucose had a 4.7 times higher risk of death compared to patients with non-low blood glucose. Race, age, sex, and diabetes had no influence on survival. Gastrointestinal and genitourinary sources for E. coli bacteremia were more commonly associated with low blood glucose (P <.001). The study was limited to E. coli-positive blood cultures and to the one hospital system. Low blood glucose is present at the onset of E. coli bacteremia in 4.6% of patients. This represents a potentially large number of patients because E. coli is the most common blood culture isolate. Low blood glucose predicts poor outcome, especially in patients with abnormal hepatic and renal function. Low blood glucose should be considered an early clinical sign of E. coli bacteremia and aggressive therapy should be instituted to potentially save lives.

  13. An artificial pancreas provided a novel model of blood glucose level variability in beagles.

    PubMed

    Munekage, Masaya; Yatabe, Tomoaki; Kitagawa, Hiroyuki; Takezaki, Yuka; Tamura, Takahiko; Namikawa, Tsutomu; Hanazaki, Kazuhiro

    2015-12-01

    Although the effects on prognosis of blood glucose level variability have gained increasing attention, it is unclear whether blood glucose level variability itself or the manifestation of pathological conditions that worsen prognosis. Then, previous reports have not been published on variability models of perioperative blood glucose levels. The aim of this study is to establish a novel variability model of blood glucose concentration using an artificial pancreas. We maintained six healthy, male beagles. After anesthesia induction, a 20-G venous catheter was inserted in the right femoral vein and an artificial pancreas (STG-22, Nikkiso Co. Ltd., Tokyo, Japan) was connected for continuous blood glucose monitoring and glucose management. After achieving muscle relaxation, total pancreatectomy was performed. After 1 h of stabilization, automatic blood glucose control was initiated using the artificial pancreas. Blood glucose level varied for 8 h, alternating between the target blood glucose values of 170 and 70 mg/dL. Eight hours later, the experiment was concluded. Total pancreatectomy was performed for 62 ± 13 min. Blood glucose swings were achieved 9.8 ± 2.3 times. The average blood glucose level was 128.1 ± 5.1 mg/dL with an SD of 44.6 ± 3.9 mg/dL. The potassium levels after stabilization and at the end of the experiment were 3.5 ± 0.3 and 3.1 ± 0.5 mmol/L, respectively. In conclusion, the results of the present study demonstrated that an artificial pancreas contributed to the establishment of a novel variability model of blood glucose levels in beagles.

  14. Glycolysis Controls Plasma Membrane Glucose Sensors To Promote Glucose Signaling in Yeasts

    PubMed Central

    Cairey-Remonnay, Amélie; Deffaud, Julien; Wésolowski-Louvel, Micheline; Lemaire, Marc

    2014-01-01

    Sensing of extracellular glucose is necessary for cells to adapt to glucose variation in their environment. In the respiratory yeast Kluyveromyces lactis, extracellular glucose controls the expression of major glucose permease gene RAG1 through a cascade similar to the Saccharomyces cerevisiae Snf3/Rgt2/Rgt1 glucose signaling pathway. This regulation depends also on intracellular glucose metabolism since we previously showed that glucose induction of the RAG1 gene is abolished in glycolytic mutants. Here we show that glycolysis regulates RAG1 expression through the K. lactis Rgt1 (KlRgt1) glucose signaling pathway by targeting the localization and probably the stability of Rag4, the single Snf3/Rgt2-type glucose sensor of K. lactis. Additionally, the control exerted by glycolysis on glucose signaling seems to be conserved in S. cerevisiae. This retrocontrol might prevent yeasts from unnecessary glucose transport and intracellular glucose accumulation. PMID:25512610

  15. Interpreting Sky-Averaged 21-cm Measurements

    NASA Astrophysics Data System (ADS)

    Mirocha, Jordan

    2015-01-01

    Within the first ~billion years after the Big Bang, the intergalactic medium (IGM) underwent a remarkable transformation, from a uniform sea of cold neutral hydrogen gas to a fully ionized, metal-enriched plasma. Three milestones during this epoch of reionization -- the emergence of the first stars, black holes (BHs), and full-fledged galaxies -- are expected to manifest themselves as extrema in sky-averaged ("global") measurements of the redshifted 21-cm background. However, interpreting these measurements will be complicated by the presence of strong foregrounds and non-trivialities in the radiative transfer (RT) modeling required to make robust predictions.I have developed numerical models that efficiently solve the frequency-dependent radiative transfer equation, which has led to two advances in studies of the global 21-cm signal. First, frequency-dependent solutions facilitate studies of how the global 21-cm signal may be used to constrain the detailed spectral properties of the first stars, BHs, and galaxies, rather than just the timing of their formation. And second, the speed of these calculations allows one to search vast expanses of a currently unconstrained parameter space, while simultaneously characterizing the degeneracies between parameters of interest. I find principally that (1) physical properties of the IGM, such as its temperature and ionization state, can be constrained robustly from observations of the global 21-cm signal without invoking models for the astrophysical sources themselves, (2) translating IGM properties to galaxy properties is challenging, in large part due to frequency-dependent effects. For instance, evolution in the characteristic spectrum of accreting BHs can modify the 21-cm absorption signal at levels accessible to first generation instruments, but could easily be confused with evolution in the X-ray luminosity star-formation rate relation. Finally, (3) the independent constraints most likely to aide in the interpretation

  16. Reengineered glucose oxidase for amperometric glucose determination in diabetes analytics.

    PubMed

    Arango Gutierrez, Erik; Mundhada, Hemanshu; Meier, Thomas; Duefel, Hartmut; Bocola, Marco; Schwaneberg, Ulrich

    2013-12-15

    Glucose oxidase is an oxidoreductase exhibiting a high β-D-glucose specificity and high stability which renders glucose oxidase well-suited for applications in diabetes care. Nevertheless, GOx activity is highly oxygen dependent which can lead to inaccuracies in amperometric β-D-glucose determinations. Therefore a directed evolution campaign with two rounds of random mutagenesis (SeSaM followed by epPCR), site saturation mutagenesis studies on individual positions, and one simultaneous site saturation library (OmniChange; 4 positions) was performed. A diabetes care well suited mediator (quinone diimine) was selected and the GOx variant (T30V I94V) served as starting point. For directed GOx evolution a microtiter plate detection system based on the quinone diimine mediator was developed and the well-known ABTS-assay was applied in microtiter plate format to validate oxygen independency of improved GOx variants. Two iterative rounds of random diversity generation and screening yielded to two subsets of amino acid positions which mainly improved activity (A173, A332) and oxygen independency (F414, V560). Simultaneous site saturation of all four positions with a reduced subset of amino acids using the OmniChange method yielded finally variant V7 with a 37-fold decreased oxygen dependency (mediator activity: 7.4 U/mg WT, 47.5 U/mg V7; oxygen activity: 172.3 U/mg WT, 30.1 U/mg V7). V7 is still highly β-D-glucose specific, highly active with the quinone diimine mediator and thermal resistance is retained (prerequisite for GOx coating of diabetes test stripes). The latter properties and V7's oxygen insensitivity make V7 a very promising candidate to replace standard GOx in diabetes care applications. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Average spectral efficiency analysis of FSO links over turbulence channel with adaptive transmissions and aperture averaging

    NASA Astrophysics Data System (ADS)

    Aarthi, G.; Ramachandra Reddy, G.

    2018-03-01

    In our paper, the impact of adaptive transmission schemes: (i) optimal rate adaptation (ORA) and (ii) channel inversion with fixed rate (CIFR) on the average spectral efficiency (ASE) are explored for free-space optical (FSO) communications with On-Off Keying (OOK), Polarization shift keying (POLSK), and Coherent optical wireless communication (Coherent OWC) systems under different turbulence regimes. Further to enhance the ASE we have incorporated aperture averaging effects along with the above adaptive schemes. The results indicate that ORA adaptation scheme has the advantage of improving the ASE performance compared with CIFR under moderate and strong turbulence regime. The coherent OWC system with ORA excels the other modulation schemes and could achieve ASE performance of 49.8 bits/s/Hz at the average transmitted optical power of 6 dBm under strong turbulence. By adding aperture averaging effect we could achieve an ASE of 50.5 bits/s/Hz under the same conditions. This makes ORA with Coherent OWC modulation as a favorable candidate for improving the ASE of the FSO communication system.

  18. Properties of model-averaged BMDLs: a study of model averaging in dichotomous response risk estimation.

    PubMed

    Wheeler, Matthew W; Bailer, A John

    2007-06-01

    Model averaging (MA) has been proposed as a method of accounting for model uncertainty in benchmark dose (BMD) estimation. The technique has been used to average BMD dose estimates derived from dichotomous dose-response experiments, microbial dose-response experiments, as well as observational epidemiological studies. While MA is a promising tool for the risk assessor, a previous study suggested that the simple strategy of averaging individual models' BMD lower limits did not yield interval estimators that met nominal coverage levels in certain situations, and this performance was very sensitive to the underlying model space chosen. We present a different, more computationally intensive, approach in which the BMD is estimated using the average dose-response model and the corresponding benchmark dose lower bound (BMDL) is computed by bootstrapping. This method is illustrated with TiO(2) dose-response rat lung cancer data, and then systematically studied through an extensive Monte Carlo simulation. The results of this study suggest that the MA-BMD, estimated using this technique, performs better, in terms of bias and coverage, than the previous MA methodology. Further, the MA-BMDL achieves nominal coverage in most cases, and is superior to picking the "best fitting model" when estimating the benchmark dose. Although these results show utility of MA for benchmark dose risk estimation, they continue to highlight the importance of choosing an adequate model space as well as proper model fit diagnostics.

  19. A Microgenetic Analysis of Strategic Variability in Gifted and Average-Ability Children

    ERIC Educational Resources Information Center

    Steiner, Hillary Hettinger

    2006-01-01

    Many researchers have described cognitive differences between gifted and average-performing children. Regarding strategy use, the gifted advantage is often associated with differences such as greater knowledge of strategies, quicker problem solving, and the ability to use strategies more appropriately. The current study used microgenetic methods…

  20. A case of perioperative glucose control by using an artificial pancreas in a patient with glycogen storage disease.

    PubMed

    Yatabe, Tomoaki; Nakamura, Ryu; Kitagawa, Hiroyuki; Munekage, Masaya; Hanazaki, Kazuhiro

    2016-03-01

    A 57-year-old woman was diagnosed with type I glycogen storage disease in her twenties. She had undergone hepatectomy under general anesthesia with epidural anesthesia. Fifty minutes after the induction of anesthesia, a 20-gauge venous catheter was inserted in the patient's right hand, and an artificial pancreas (STG-55, Nikkiso Co., Tokyo, Japan) was connected for continuous glucose monitoring and automatic glucose control. Insulin was infused when the blood glucose level reached 120 mg/dL or higher, and glucose was infused when the level fell to 100 mg/dL or lower. After the Pringle maneuver, the blood glucose level increased, and insulin was administered automatically via an artificial pancreas. Hypoglycemia did not occur during the operation. After total parenteral nutrition was started in the intensive care unit (ICU), the blood glucose level increased, and the artificial pancreas controlled the blood glucose level through automatic insulin administration. Thirty-four hours after admission to the ICU, the artificial pancreas was removed because the blood sampling failed. After the removal of the artificial pancreas, blood glucose level was measured every 2 h until extubation. During the ICU stay, hypoglycemia never occurred, with the average blood glucose level being 144 mg/dL. In conclusion, the use of an artificial pancreas for perioperative blood glucose management in a patient with glycogen storage disease had the beneficial effect of enabling the management of blood glucose levels without hypoglycemia.

  1. Blood Glucose Levels in Diabetic Patients Following Corticosteroid Injections into the Subacromial Space of the Shoulder.

    PubMed

    Aleem, Alexander W; Syed, Usman Ali M; Nicholson, Thema; Getz, Charles L; Namdari, Surena; Beredjiklian, Pedro K; Abboud, Joseph A

    2017-09-01

    Corticosteroid injections are used to treat a variety of orthopedic conditions with the goal of decreasing pain and inflammation. Administration of systemic or local corticosteroids risks temporarily increasing blood glucose levels, especially diabetic patients. The purpose of this study is to quantify the effects of corticosteroid injections on blood glucose levels in diabetic patients with shoulder pathology. Diabetic patients who regularly monitored their blood glucose levels and were indicated for a subacromial corticosteroid injection were included in this prospective investigation. The typical normal morning fasting glucose and most recent hemoglobin A1c level was recorded for each patient. After injection, patients were contacted daily to confirm their fasting morning glucose level for 10 days post-injection. Seventeen consecutive patients were enrolled. Patients with hemoglobin A1c of <7% had an average rise in blood glucose of 38 mg/dL compared to 98 mg/dL in the poorly controlled group after injection ( P <0.001). Well-controlled patients' glucose levels returned to near baseline levels around post-injection day 8, while poorly controlled patients levels remained elevated. Similarly, insulin-dependent diabetic patients had an average increase in fasting glucose level of 99 mg/dL versus 50 mg/dL in non-insulin-dependent diabetic patients ( P <0.001). After corticosteroid injection, patients with well-controlled diabetes experience smaller elevations and faster return to baseline glucose levels than patients with poor control. Insulin dependent diabetics experienced similar findings as patients with poor control. Future studies are needed to evaluate dosing to optimize the risks of blood glucose elevation while maintaining therapeutic benefit.

  2. Lactate metabolism and its effects on glucose metabolism in an excised neural tissue.

    PubMed

    Larrabee, M G

    1995-04-01

    Chains of lumbar sympathetic ganglia, excised from 15-day-old chicken embryos, were incubated for 4 h at 36 degrees C in a bicarbonate-buffered physiological salt solution containing 5.5 mM glucose and equilibrated with 5% CO2-95% O2. [U-14C]Glucose and [U-14C]lactate were used as tracers to measure the products of glucose and lactate metabolism, respectively, including CO2, lactate, and constituents of the tissue. When 5 mM lactate was added to bathing solution containing 5.5 mM glucose, lactate carbon displaced 50-70% of the glucose carbon otherwise used for CO2 production and provided about three times as much carbon for CO2 as did glucose. The lactate addition increased the total carbon incorporated into CO2 and into constituents of the tissue above those observed with glucose alone and also increased the lactate released to the bathing solution from [U-14C]-glucose. The latter increase was evidently due to an interference with reuptake of the lactate released from the ganglion cells, not to an increase in the cellular release itself. When the volume of bathing solution was increased 10-fold relative to that of the tissue, the average output of CO2 from [U-14C]glucose during a 4-h incubation was decreased by 50% when 5 mM lactate was present but was not affected significantly in the absence of added lactate. It is concluded that the effect of changing volume in the presence of lactate was due to the effects of lactate on glucose metabolism described above and resulted from a lower average lactate concentration in the smaller volume than in the larger one, due to metabolic depletion of the added lactate.(ABSTRACT TRUNCATED AT 250 WORDS)

  3. Influence of ketamine on regional brain glucose use

    SciTech Connect

    Davis, D.W.; Mans, A.M.; Biebuyck, J.F.

    1988-08-01

    The purpose of this study was to determine the effect of different doses of ketamine on cerebral function at the level of individual brain structures as reflected by glucose use. Rats received either 5 or 30 mg/kg ketamine intravenously as a loading dose, followed by an infusion to maintain a steady-state level of the drug. An additional group received 30 mg/kg as a single injection only, and was studied 20 min later, by which time they were recovering consciousness (withdrawal group). Regional brain energy metabolism was evaluated with (6-/sup 14/C)glucose and quantitative autoradiography during a 5-min experimental period. A subhypnotic,more » steady-state dose (5 mg/kg) of ketamine caused a stimulation of glucose use in most brain areas, with an average increase of 20%. At the larger steady-state dose (30 mg/kg, which is sufficient to cause anesthesia), there was no significant effect on most brain regions; some sensory nuclei were depressed (inferior colliculus, -29%; cerebellar dentate nucleus, -18%; vestibular nucleus, -16%), but glucose use in the ventral posterior hippocampus was increased by 33%. In contrast, during withdrawal from a 30-mg/kg bolus, there was a stimulation of glucose use throughout the brain (21-78%), at a time when plasma ketamine levels were similar to the levels in the 5 mg/kg group. At each steady-state dose, as well as during withdrawal, ketamine caused a notable stimulation of glucose use by the hippocampus.« less

  4. Hypothalamic neurones governing glucose homeostasis.

    PubMed

    Coppari, R

    2015-06-01

    The notion that the brain directly controls the level of glucose in the blood (glycaemia) independent of its known action on food intake and body weight has been known ever since 1849. That year, the French physiologist Dr Claude Bernard reported that physical puncture of the floor of the fourth cerebral ventricle rapidly leads to an increased level of sugar in the blood (and urine) in rabbits. Despite this important discovery, it took approximately 150 years before significant efforts aimed at understanding the underlying mechanism of brain-mediated control of glucose metabolism were made. Technological developments allowing for genetically-mediated manipulation of selected molecular pathways in a neurone-type-specific fashion unravelled the importance of specific molecules in specific neuronal populations. These neuronal pathways govern glucose metabolism in the presence and even in the absence of insulin. Also, a peculiarity of these pathways is that certain biochemically-defined neurones govern glucose metabolism in a tissue-specific fashion. © 2015 British Society for Neuroendocrinology.

  5. Photoacoustic experiments of glucose aqueous solution based on pulsed laser induced ultrasonic technique

    NASA Astrophysics Data System (ADS)

    Ren, Zhong; Liu, Guodong; Huang, Zheng; Ding, Yu

    2017-10-01

    In this work, to further find the characteristic wavelengths of glucose, the photoacoustic experiments of glucose aqueous solutions were performed by using the photoacoustic technique. The photoacoustic detection system was established by the Q switched Nd: YAG OPO pulsed laser and ultrasonic detector with central frequency of 20MHz. The photoacoustic signals of samples were averaged with 512 times. Baed on the established photoacoustic detection system, the time-resolved photoacoustic signals of glucose with different concentrations at the different wavelengths were captured by the digital oscilloscope, and compared with that of the pure water. In order to get the characteristic wavelengths of glucose, the photoacoustic peak-to-peak values of glucose with different concentrations at the wavelength from 1350nm to 2100nm were obtained, and the difference spectral was gotten by using the difference method between the glucose solutions and pure water. Moreover, the first order derivation method was also used. The wavelength of 1650nm and 1850nm was chosen as the characteristic wavelengths of glucose. The linear fitting equation was established to verify the availability of two characteristic wavelengths. The average prediction error results showed that the choosing of the characteristic wavelength of 1650nm and 1850nm is available.

  6. Determining average path length and average trapping time on generalized dual dendrimer

    NASA Astrophysics Data System (ADS)

    Li, Ling; Guan, Jihong

    2015-03-01

    Dendrimer has wide number of important applications in various fields. In some cases during transport or diffusion process, it transforms into its dual structure named Husimi cactus. In this paper, we study the structure properties and trapping problem on a family of generalized dual dendrimer with arbitrary coordination numbers. We first calculate exactly the average path length (APL) of the networks. The APL increases logarithmically with the network size, indicating that the networks exhibit a small-world effect. Then we determine the average trapping time (ATT) of the trapping process in two cases, i.e., the trap placed on a central node and the trap is uniformly distributed in all the nodes of the network. In both case, we obtain explicit solutions of ATT and show how they vary with the networks size. Besides, we also discuss the influence of the coordination number on trapping efficiency.

  7. Instantaneous, phase-averaged, and time-averaged pressure from particle image velocimetry

    NASA Astrophysics Data System (ADS)

    de Kat, Roeland

    2015-11-01

    Recent work on pressure determination using velocity data from particle image velocimetry (PIV) resulted in approaches that allow for instantaneous and volumetric pressure determination. However, applying these approaches is not always feasible (e.g. due to resolution, access, or other constraints) or desired. In those cases pressure determination approaches using phase-averaged or time-averaged velocity provide an alternative. To assess the performance of these different pressure determination approaches against one another, they are applied to a single data set and their results are compared with each other and with surface pressure measurements. For this assessment, the data set of a flow around a square cylinder (de Kat & van Oudheusden, 2012, Exp. Fluids 52:1089-1106) is used. RdK is supported by a Leverhulme Trust Early Career Fellowship.

  8. 20 CFR 404.220 - Average-monthly-wage method.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... average-monthly-wage method if it is to your advantage. Being eligible for either the average-monthly-wage method or the modified average-monthly-wage method does not preclude your eligibility under the old-start...

  9. Dynamic testing and test anxiety amongst gifted and average-ability children.

    PubMed

    Vogelaar, Bart; Bakker, Merel; Elliott, Julian G; Resing, Wilma C M

    2017-03-01

    Dynamic testing has been proposed as a testing approach that is less disadvantageous for children who may be potentially subject to bias when undertaking conventional assessments. For example, those who encounter high levels of test anxiety, or who are unfamiliar with standardized test procedures, may fail to demonstrate their true potential or capabilities. While dynamic testing has proven particularly useful for special groups of children, it has rarely been used with gifted children. We investigated whether it would be useful to conduct a dynamic test to measure the cognitive abilities of intellectually gifted children. We also investigated whether test anxiety scores would be related to a progression in the children's test scores after dynamic training. Participants were 113 children aged between 7 and 8 years from several schools in the western part of the Netherlands. The children were categorized as either gifted or average-ability and split into an unguided practice or a dynamic testing condition. The study employed a pre-test-training-post-test design. Using linear mixed modelling analysis with a multilevel approach, we inspected the growth trajectories of children in the various conditions and examined the impact of ability and test anxiety on progression and training benefits. Dynamic testing proved to be successful in improving the scores of the children, although no differences in training benefits were found between gifted and average-ability children. Test anxiety was shown to influence the children's rate of change across all test sessions and their improvement in performance accuracy after dynamic training. © 2016 The British Psychological Society.

  10. Lagrangian averages, averaged Lagrangians, and the mean effects of fluctuations in fluid dynamics.

    PubMed

    Holm, Darryl D.

    2002-06-01

    We begin by placing the generalized Lagrangian mean (GLM) equations for a compressible adiabatic fluid into the Euler-Poincare (EP) variational framework of fluid dynamics, for an averaged Lagrangian. This is the Lagrangian averaged Euler-Poincare (LAEP) theorem. Next, we derive a set of approximate small amplitude GLM equations (glm equations) at second order in the fluctuating displacement of a Lagrangian trajectory from its mean position. These equations express the linear and nonlinear back-reaction effects on the Eulerian mean fluid quantities by the fluctuating displacements of the Lagrangian trajectories in terms of their Eulerian second moments. The derivation of the glm equations uses the linearized relations between Eulerian and Lagrangian fluctuations, in the tradition of Lagrangian stability analysis for fluids. The glm derivation also uses the method of averaged Lagrangians, in the tradition of wave, mean flow interaction. Next, the new glm EP motion equations for incompressible ideal fluids are compared with the Euler-alpha turbulence closure equations. An alpha model is a GLM (or glm) fluid theory with a Taylor hypothesis closure. Such closures are based on the linearized fluctuation relations that determine the dynamics of the Lagrangian statistical quantities in the Euler-alpha equations. Thus, by using the LAEP theorem, we bridge between the GLM equations and the Euler-alpha closure equations, through the small-amplitude glm approximation in the EP variational framework. We conclude by highlighting a new application of the GLM, glm, and alpha-model results for Lagrangian averaged ideal magnetohydrodynamics. (c) 2002 American Institute of Physics.

  11. Human perceptions of colour rendition vary with average fidelity, average gamut, and gamut shape

    SciTech Connect

    Royer, MP; Wilkerson, A.; Wei, M.

    An experiment was conducted to evaluate how subjective impressions of color quality vary with changes in average fidelity, average gamut, and gamut shape (which considers the specific hues that are saturated or desaturated). Twenty-eight participants each evaluated 26 lighting conditions—created using four, seven-channel, tunable LED luminaires—in a 3.1 m by 3.7 m room filled with objects selected to cover a range of hue, saturation, and lightness. IES TM-30 fidelity index (Rf) values ranged from 64 to 93, IES TM-30 gamut index (Rg¬) values from 79 to 117, and IES TM-30 Rcs,h1 values (a proxy for gamut shape) from -19% tomore » 26%. All lighting conditions delivered the same nominal illuminance and chromaticity. Participants were asked to rate each condition on eight point semantic differential scales for saturated-dull, normal-shifted, and like-dislike. They were also asked one multiple choice question, classifying the condition as saturated, dull, normal, or shifted. The findings suggest that gamut shape is more important than average gamut for human preference, where reds play a more important role than other hues. Additionally, average fidelity alone is a poor predictor of human perceptions, although Rf was somewhat better than CIE Ra. The most preferred source had a CIE Ra value of 68, and 9 of the top 12 rated products had a CIE Ra value of 73 or less, which indicates that the commonly used criteria of CIE Ra ≥ 80 may be excluding a majority of preferred light sources.« less

  12. Glucose Sensing for Diabetes Monitoring: Recent Developments

    PubMed Central

    Bruen, Danielle; Delaney, Colm; Florea, Larisa

    2017-01-01

    This review highlights recent advances towards non-invasive and continuous glucose monitoring devices, with a particular focus placed on monitoring glucose concentrations in alternative physiological fluids to blood. PMID:28805693

  13. 40 CFR 80.205 - How is the annual refinery or importer average and corporate pool average sulfur level determined?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... average and corporate pool average sulfur level determined? 80.205 Section 80.205 Protection of... ADDITIVES Gasoline Sulfur Gasoline Sulfur Standards § 80.205 How is the annual refinery or importer average and corporate pool average sulfur level determined? (a) The annual refinery or importer average and...

  14. 40 CFR 80.205 - How is the annual refinery or importer average and corporate pool average sulfur level determined?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... average and corporate pool average sulfur level determined? 80.205 Section 80.205 Protection of... ADDITIVES Gasoline Sulfur Gasoline Sulfur Standards § 80.205 How is the annual refinery or importer average and corporate pool average sulfur level determined? (a) The annual refinery or importer average and...

  15. 40 CFR 80.205 - How is the annual refinery or importer average and corporate pool average sulfur level determined?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... average and corporate pool average sulfur level determined? 80.205 Section 80.205 Protection of... ADDITIVES Gasoline Sulfur Gasoline Sulfur Standards § 80.205 How is the annual refinery or importer average and corporate pool average sulfur level determined? (a) The annual refinery or importer average and...

  16. 40 CFR 80.205 - How is the annual refinery or importer average and corporate pool average sulfur level determined?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... average and corporate pool average sulfur level determined? 80.205 Section 80.205 Protection of... ADDITIVES Gasoline Sulfur Gasoline Sulfur Standards § 80.205 How is the annual refinery or importer average and corporate pool average sulfur level determined? (a) The annual refinery or importer average and...

  17. Superior long-term stability of a glucose biosensor based on inserted barrel plating gold electrodes.

    PubMed

    Hsu, Cheng-Teng; Hsiao, Hung-Chan; Fang, Mei-Yen; Zen, Jyh-Myng

    2009-10-15

    Disposable one shot usage blood glucose strips are routinely used in the diagnosis and management of diabetes mellitus and their performance can vary greatly. In this paper we critically evaluated the long-term stability of glucose strips made of barrel plating gold electrodes. Compared to other glucose biosensing platforms of vapor deposited palladium and screen printed carbon electrodes, the proposed glucose biosensor was found to show the best stability among the three biosensing platforms in thermal acceleration experiments at 40 degrees C for 6 months with an average bias of 3.4% at glucose concentrations of 5-20 mM. The precision test of this barrel plating gold glucose biosensor also showed the best performance (coefficients of variation in the range of 1.4-2.4%) in thermal acceleration experiments at 40 degrees C, 50 degrees C and 70 degrees C for 27 days. Error grid analysis revealed that all measurements fell in zone A and zone B. Regression analysis showed no significant difference between the proposed biosensor and the reference method at 99% confidence level. The amperometric glucose biosensor fabricated by inserting two barrel plating gold electrodes onto an injection-molding plastic base followed by immobilizing with a bio-reagent layer and membrane was very impressive with a long-term stability up to 2.5 years at 25 degrees C. Overall, these results indicated that the glucose oxidase/barrel plating gold biosensing platform is ideal for long-term accurate glycemic control.

  18. Near-infrared spectral methods for noninvasively measuring blood glucose

    NASA Astrophysics Data System (ADS)

    Fei, Sun; Kong, Deyi; Mei, Tao; Tao, Yongchun

    2004-05-01

    Determination of blood glucose concentrations in diabetic patients is a frequently occurring procedure and an important tool for diabetes management. Use of noninvasive detection techniques can relieve patients from the pain of frequent finger pokes and avoid the infection of disease via blood. This thesis discusses current research and analyzes the advantages and shortages of different measurement methods, including: optical methods (Transmission, Polarimetry and scattering), then, we give emphasis to analyze the technology of near-infrared (NIR) spectra. NIR spectral range 700 nm ~2300 nm was used because of its good transparency for biological tissue and presence of glucose absorption band. In this work, we present an outline of noninvasive blood glucose measurement. A near-infrared light beam is passed through the finger, and the spectral components of the emergent beam are measured using spectroscopic techniques. The device includes light sources having the wavelengths of 600 nm - 1800 nm to illuminate the tissue. Receptors associated with the light sources for receiving light and generating a transmission signal representing the light transmitted are also provided. Once a transmission signal is received by receptors, and the high and low values from each of the signals are stored in the device. The averaged values are then analyzed to determine the glucose concentration, which is displayed on the device.

  19. Pulse-voltammetric glucose detection at gold junction electrodes.

    PubMed

    Rassaei, Liza; Marken, Frank

    2010-09-01

    A novel glucose sensing concept based on the localized change or "modulation" in pH within a symmetric gold-gold junction electrode is proposed. A paired gold-gold junction electrode (average gap size ca. 500 nm) is prepared by simultaneous bipotentiostatic electrodeposition of gold onto two closely spaced platinum disk electrodes. For glucose detection in neutral aqueous solution, the potential of the "pH-modulator" electrode is set to -1.5 V vs saturated calomel reference electrode (SCE) to locally increase the pH, and simultaneously, either cyclic voltammetry or square wave voltammetry experiments are conducted at the sensor electrode. A considerable improvement in the sensor electrode response is observed when a normal pulse voltammetry sequence is applied to the modulator electrode (to generate "hydroxide pulses") and the glucose sensor electrode is operated with fixed bias at +0.5 V vs SCE (to eliminate capacitive charging currents). Preliminary data suggest good linearity for the glucose response in the medically relevant 1-10 mM concentration range (corresponding to 0.18-1.8 g L(-1)). Future electroanalytical applications of multidimensional pulse voltammetry in junction electrodes are discussed.

  20. Glucose transport machinery reconstituted in cell models.

    PubMed

    Hansen, Jesper S; Elbing, Karin; Thompson, James R; Malmstadt, Noah; Lindkvist-Petersson, Karin

    2015-02-11

    Here we demonstrate the production of a functioning cell model by formation of giant vesicles reconstituted with the GLUT1 glucose transporter and a glucose oxidase and hydrogen peroxidase linked fluorescent reporter internally. Hence, a simplified artificial cell is formed that is able to take up glucose and process it.

  1. Glucose Transport Machinery Reconstituted in Cell Models

    PubMed Central

    Hansen, Jesper S.; Elbing, Karin; Thompson, James R.; Malmstadt, Noah

    2015-01-01

    Here we demonstrate the production of a functioning cell model by formation of giant vesicles reconstituted with the GLUT1 glucose transporter and a glucose oxidase and hydrogen peroxidase linked fluorescent reporter internally. Hence, a simplified artificial cell is formed that is able to take up glucose and process it. PMID:25562394

  2. Glucose diffusion in pancreatic islets of Langerhans.

    PubMed Central

    Bertram, R; Pernarowski, M

    1998-01-01

    We investigate the time required for glucose to diffuse through an isolated pancreatic islet of Langerhans and reach an equilibrium. This question is relevant in the context of in vitro electrophysiological studies of the response of an islet to step changes in the bath glucose concentration. Islet cells are electrically coupled by gap junctions, so nonuniformities in islet glucose concentration may be reflected in the activity of cells on the islet periphery, where electrical recordings are made. Using a mathematical model of hindered glucose diffusion, we investigate the effects of the islet porosity and the permeability of a surrounding layer of acinar cells. A major factor in the determination of the equilibrium time is the transport of glucose into islet beta-cells, which removes glucose from the interstitial spaces where diffusion occurs. This transport is incorporated by using a model of the GLUT-2 glucose transporter. We find that several minutes are required for the islet to equilibrate to a 10 mM change in bath glucose, a typical protocol in islet experiments. It is therefore likely that in electrophysiological islet experiments the glucose distribution is nonuniform for several minutes after a step change in bath glucose. The delay in glucose penetration to the inner portions of the islet may be a major contributing factor to the 1-2-min delay in islet electrical activity typically observed after bath application of a stimulatory concentration of glucose. PMID:9545035

  3. Blood Glucose Levels and Problem Behavior

    ERIC Educational Resources Information Center

    Valdovinos, Maria G.; Weyand, David

    2006-01-01

    The relationship between varying blood glucose levels and problem behavior during daily scheduled activities was examined. The effects that varying blood glucose levels had on problem behavior during daily scheduled activities were examined. Prior research has shown that differing blood glucose levels can affect behavior and mood. Results of this…

  4. Brain glucose sensing, counterregulation, and energy homeostasis.

    PubMed

    Marty, Nell; Dallaporta, Michel; Thorens, Bernard

    2007-08-01

    Neuronal circuits in the central nervous system play a critical role in orchestrating the control of glucose and energy homeostasis. Glucose, beside being a nutrient, is also a signal detected by several glucose-sensing units that are located at different anatomical sites and converge to the hypothalamus to cooperate with leptin and insulin in controlling the melanocortin pathway.

  5. Changes in average length of stay and average charges generated following institution of PSRO review.

    PubMed Central

    Westphal, M; Frazier, E; Miller, M C

    1979-01-01

    A five-year review of accounting data at a university hospital shows that immediately following institution of concurrent PSRO admission and length of stay review of Medicare-Medicaid patients, there was a significant decrease in length of stay and a fall in average charges generated per patient against the inflationary trend. Similar changes did not occur for the non-Medicare-Medicaid patients who were not reviewed. The observed changes occurred even though the review procedure rarely resulted in the denial of services to patients, suggesting an indirect effect of review. PMID:393658

  6. Glucose turnover and defense of blood glucose levels in Arctic fox (Alopex lagopus).

    PubMed

    Tallas, P G; White, R G

    1988-01-01

    1. Glucose utilization was assessed in fed and fasted arctic fox, maintained on a diet similar in composition to food available in the wild. 2. Fasted (24 hr) glucose concentration was not significantly different from the fed level (134 mg/dl). 3. Fasting was associated with a significant reduction in glucose space, pool size, total entry rate, and irreversible loss which suggests a decline in gluconeogenesis. 4. Glucose recycling was not significantly different between the fed and fasted states. 5. We suggest that, in the arctic fox, the mechanism for defending blood glucose levels during fasting is based on restricting blood glucose to tissues with a high glucose dependency.

  7. Estimating Plasma Glucose from Interstitial Glucose: The Issue of Calibration Algorithms in Commercial Continuous Glucose Monitoring Devices

    PubMed Central

    Rossetti, Paolo; Bondia, Jorge; Vehí, Josep; Fanelli, Carmine G.

    2010-01-01

    Evaluation of metabolic control of diabetic people has been classically performed measuring glucose concentrations in blood samples. Due to the potential improvement it offers in diabetes care, continuous glucose monitoring (CGM) in the subcutaneous tissue is gaining popularity among both patients and physicians. However, devices for CGM measure glucose concentration in compartments other than blood, usually the interstitial space. This means that CGM need calibration against blood glucose values, and the accuracy of the estimation of blood glucose will also depend on the calibration algorithm. The complexity of the relationship between glucose dynamics in blood and the interstitial space, contrasts with the simplistic approach of calibration algorithms currently implemented in commercial CGM devices, translating in suboptimal accuracy. The present review will analyze the issue of calibration algorithms for CGM, focusing exclusively on the commercially available glucose sensors. PMID:22163505

  8. Non-invasive glucose monitor

    NASA Technical Reports Server (NTRS)

    Lambert, James L. (Inventor); Borchert, Mark S. (Inventor)

    2001-01-01

    A non-invasive method for determining blood level of an analyte of interest, such as glucose, comprises: generating an excitation laser beam (e.g., at a wavelength of 700 to 900 nanometers); focusing the excitation laser beam into the anterior chamber of an eye of the subject so that aqueous humor in the anterior chamber is illuminated; detecting (preferably confocally detecting) a Raman spectrum from the illuminated aqueous humor; and then determining the blood glucose level (or the level of another analyte of interest) for the subject from the Raman spectrum. Preferably, the detecting step is followed by the step of subtracting a confounding fluorescence spectrum from the Raman spectrum to produce a difference spectrum; and determining the blood level of the analyte of interest for the subject from that difference spectrum, preferably using linear or nonlinear multivariate analysis such as partial least squares analysis. Apparatus for carrying out the foregoing method is also disclosed.

  9. 20 CFR 226.62 - Computing average monthly compensation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Computing average monthly compensation. 226... RETIREMENT ACT COMPUTING EMPLOYEE, SPOUSE, AND DIVORCED SPOUSE ANNUITIES Years of Service and Average Monthly Compensation § 226.62 Computing average monthly compensation. The employee's average monthly compensation is...

  10. Diet Treatment Glucose Transporter Type 1 Deficiency (G1D)

    ClinicalTrials.gov

    2018-06-20

    GLUT1DS1; Epilepsy; Glut1 Deficiency Syndrome 1, Autosomal Recessive; Glucose Metabolism Disorders; Glucose Transport Defect; Glucose Transporter Type 1 Deficiency Syndrome; Glucose Transporter Protein Type 1 Deficiency Syndrome

  11. Blood Glucose Test: MedlinePlus Lab Test Information

    MedlinePlus

    ... https://medlineplus.gov/labtests/bloodglucosetest.html Blood Glucose Test To use the sharing features on this page, please enable JavaScript. What is a Blood Glucose Test? A blood glucose test measures the glucose levels ...

  12. Scaling of average weighted shortest path and average receiving time on weighted expanded Koch networks

    NASA Astrophysics Data System (ADS)

    Wu, Zikai; Hou, Baoyu; Zhang, Hongjuan; Jin, Feng

    2014-04-01

    Deterministic network models have been attractive media for discussing dynamical processes' dependence on network structural features. On the other hand, the heterogeneity of weights affect dynamical processes taking place on networks. In this paper, we present a family of weighted expanded Koch networks based on Koch networks. They originate from a r-polygon, and each node of current generation produces m r-polygons including the node and whose weighted edges are scaled by factor w in subsequent evolutionary step. We derive closed-form expressions for average weighted shortest path length (AWSP). In large network, AWSP stays bounded with network order growing (0 < w < 1). Then, we focus on a special random walks and trapping issue on the networks. In more detail, we calculate exactly the average receiving time (ART). ART exhibits a sub-linear dependence on network order (0 < w < 1), which implies that nontrivial weighted expanded Koch networks are more efficient than un-weighted expanded Koch networks in receiving information. Besides, efficiency of receiving information at hub nodes is also dependent on parameters m and r. These findings may pave the way for controlling information transportation on general weighted networks.

  13. Prochlorococcus can use the Pro1404 transporter to take up glucose at nanomolar concentrations in the Atlantic Ocean

    PubMed Central

    Muñoz-Marín, María del Carmen; Luque, Ignacio; Zubkov, Mikhail V.; Hill, Polly G.; Diez, Jesús; García-Fernández, José Manuel

    2013-01-01

    Prochlorococcus is responsible for a significant part of CO2 fixation in the ocean. Although it was long considered an autotrophic cyanobacterium, the uptake of organic compounds has been reported, assuming they were sources of limited biogenic elements. We have shown in laboratory experiments that Prochlorococcus can take up glucose. However, the mechanisms of glucose uptake and its occurrence in the ocean have not been shown. Here, we report that the gene Pro1404 confers capability for glucose uptake in Prochlorococcus marinus SS120. We used a cyanobacterium unable to take up glucose to engineer strains that express the Pro1404 gene. These recombinant strains were capable of specific glucose uptake over a wide range of glucose concentrations, showing multiphasic transport kinetics. The Ks constant of the high affinity phase was in the nanomolar range, consistent with the average concentration of glucose in the ocean. Furthermore, we were able to observe glucose uptake by Prochlorococcus in the central Atlantic Ocean, where glucose concentrations were 0.5–2.7 nM. Our results suggest that Prochlorococcus are primary producers capable of tuning their metabolism to energetically benefit from environmental conditions, taking up not only organic compounds with key limiting elements in the ocean, but also molecules devoid of such elements, like glucose. PMID:23569224

  14. Anchored phosphatases modulate glucose homeostasis

    PubMed Central

    Hinke, Simon A; Navedo, Manuel F; Ulman, Allison; Whiting, Jennifer L; Nygren, Patrick J; Tian, Geng; Jimenez-Caliani, Antonio J; Langeberg, Lorene K; Cirulli, Vincenzo; Tengholm, Anders; Dell'Acqua, Mark L; Santana, L Fernando; Scott, John D

    2012-01-01

    Endocrine release of insulin principally controls glucose homeostasis. Nutrient-induced exocytosis of insulin granules from pancreatic β-cells involves ion channels and mobilization of Ca2+ and cyclic AMP (cAMP) signalling pathways. Whole-animal physiology, islet studies and live-β-cell imaging approaches reveal that ablation of the kinase/phosphatase anchoring protein AKAP150 impairs insulin secretion in mice. Loss of AKAP150 impacts L-type Ca2+ currents, and attenuates cytoplasmic accumulation of Ca2+ and cAMP in β-cells. Yet surprisingly AKAP150 null animals display improved glucose handling and heightened insulin sensitivity in skeletal muscle. More refined analyses of AKAP150 knock-in mice unable to anchor protein kinase A or protein phosphatase 2B uncover an unexpected observation that tethering of phosphatases to a seven-residue sequence of the anchoring protein is the predominant molecular event underlying these metabolic phenotypes. Thus anchored signalling events that facilitate insulin secretion and glucose homeostasis may be set by AKAP150 associated phosphatase activity. PMID:22940692

  15. Kinetic energy equations for the average-passage equation system

    NASA Technical Reports Server (NTRS)

    Johnson, Richard W.; Adamczyk, John J.

    1989-01-01

    Important kinetic energy equations derived from the average-passage equation sets are documented, with a view to their interrelationships. These kinetic equations may be used for closing the average-passage equations. The turbulent kinetic energy transport equation used is formed by subtracting the mean kinetic energy equation from the averaged total instantaneous kinetic energy equation. The aperiodic kinetic energy equation, averaged steady kinetic energy equation, averaged unsteady kinetic energy equation, and periodic kinetic energy equation, are also treated.

  16. Analysis and comparison of safety models using average daily, average hourly, and microscopic traffic.

    PubMed

    Wang, Ling; Abdel-Aty, Mohamed; Wang, Xuesong; Yu, Rongjie

    2018-02-01

    There have been plenty of traffic safety studies based on average daily traffic (ADT), average hourly traffic (AHT), or microscopic traffic at 5 min intervals. Nevertheless, not enough research has compared the performance of these three types of safety studies, and seldom of previous studies have intended to find whether the results of one type of study is transferable to the other two studies. First, this study built three models: a Bayesian Poisson-lognormal model to estimate the daily crash frequency using ADT, a Bayesian Poisson-lognormal model to estimate the hourly crash frequency using AHT, and a Bayesian logistic regression model for the real-time safety analysis using microscopic traffic. The model results showed that the crash contributing factors found by different models were comparable but not the same. Four variables, i.e., the logarithm of volume, the standard deviation of speed, the logarithm of segment length, and the existence of diverge segment, were positively significant in the three models. Additionally, weaving segments experienced higher daily and hourly crash frequencies than merge and basic segments. Then, each of the ADT-based, AHT-based, and real-time models was used to estimate safety conditions at different levels: daily and hourly, meanwhile, the real-time model was also used in 5 min intervals. The results uncovered that the ADT- and AHT-based safety models performed similar in predicting daily and hourly crash frequencies, and the real-time safety model was able to provide hourly crash frequency. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. A Disposable Tear Glucose Biosensor—Part 4

    PubMed Central

    Engelschall, Erica; Lan, Kenneth; Shah, Pankti; Saez, Neil; Maxwell, Stephanie; Adamson, Teagan; Abou-Eid, Michelle; McAferty, Kenyon; Patel, Dharmendra R.; Cook, Curtiss B.

    2014-01-01

    Objective: A prototype tear glucose (TG) sensor was tested in New Zealand white rabbits to assess eye irritation, blood glucose (BG) and TG lag time, and correlation with BG. Methods: A total of 4 animals were used. Eye irritation was monitored by Lissamine green dye and analyzed using image analysis software. Lag time was correlated with an oral glucose load while recording TG and BG readings. Correlation between TG and BG were plotted against one another to form a correlation diagram, using a Yellow Springs Instrument (YSI) and self-monitoring of blood glucose as the reference measurements. Finally, TG levels were calculated using analytically derived expressions. Results: From repeated testing carried over the course of 12 months, little to no eye irritation was detected. TG fluctuations over time visually appeared to trace the same pattern as BG with an average lag times of 13 minutes. TG levels calculated from the device current measurements ranged from 4 to 20 mg/dL and correlated linearly with BG levels of 75-160 mg/dL (TG = 0.1723 BG = 7.9448 mg/dL; R2 = .7544). Conclusion: The first steps were taken toward preliminary development of a sensor for self-monitoring of tear glucose (SMTG). No conjunctival irritation in any of the animals was noted. Lag time between TG and BG was found to be noticeable, but a quantitative modeling to correlate lag time in this study is unnecessary. Measured currents from the sensors and the calculated TG showed promising correlation to BG levels. Previous analytical bench marking showed BG and TG levels consistent with other literature. PMID:24876546

  18. Personalized glucose forecasting for type 2 diabetes using data assimilation

    PubMed Central

    Albers, David J.; Gluckman, Bruce; Ginsberg, Henry; Hripcsak, George; Mamykina, Lena

    2017-01-01

    Type 2 diabetes leads to premature death and reduced quality of life for 8% of Americans. Nutrition management is critical to maintaining glycemic control, yet it is difficult to achieve due to the high individual differences in glycemic response to nutrition. Anticipating glycemic impact of different meals can be challenging not only for individuals with diabetes, but also for expert diabetes educators. Personalized computational models that can accurately forecast an impact of a given meal on an individual’s blood glucose levels can serve as the engine for a new generation of decision support tools for individuals with diabetes. However, to be useful in practice, these computational engines need to generate accurate forecasts based on limited datasets consistent with typical self-monitoring practices of individuals with type 2 diabetes. This paper uses three forecasting machines: (i) data assimilation, a technique borrowed from atmospheric physics and engineering that uses Bayesian modeling to infuse data with human knowledge represented in a mechanistic model, to generate real-time, personalized, adaptable glucose forecasts; (ii) model averaging of data assimilation output; and (iii) dynamical Gaussian process model regression. The proposed data assimilation machine, the primary focus of the paper, uses a modified dual unscented Kalman filter to estimate states and parameters, personalizing the mechanistic models. Model selection is used to make a personalized model selection for the individual and their measurement characteristics. The data assimilation forecasts are empirically evaluated against actual postprandial glucose measurements captured by individuals with type 2 diabetes, and against predictions generated by experienced diabetes educators after reviewing a set of historical nutritional records and glucose measurements for the same individual. The evaluation suggests that the data assimilation forecasts compare well with specific glucose measurements

  19. Statistical transformation and the interpretation of inpatient glucose control data.

    PubMed

    Saulnier, George E; Castro, Janna C; Cook, Curtiss B

    2014-03-01

    To introduce a statistical method of assessing hospital-based non-intensive care unit (non-ICU) inpatient glucose control. Point-of-care blood glucose (POC-BG) data from hospital non-ICUs were extracted for January 1 through December 31, 2011. Glucose data distribution was examined before and after Box-Cox transformations and compared to normality. Different subsets of data were used to establish upper and lower control limits, and exponentially weighted moving average (EWMA) control charts were constructed from June, July, and October data as examples to determine if out-of-control events were identified differently in nontransformed versus transformed data. A total of 36,381 POC-BG values were analyzed. In all 3 monthly test samples, glucose distributions in nontransformed data were skewed but approached a normal distribution once transformed. Interpretation of out-of-control events from EWMA control chart analyses also revealed differences. In the June test data, an out-of-control process was identified at sample 53 with nontransformed data, whereas the transformed data remained in control for the duration of the observed period. Analysis of July data demonstrated an out-of-control process sooner in the transformed (sample 55) than nontransformed (sample 111) data, whereas for October, transformed data remained in control longer than nontransformed data. Statistical transformations increase the normal behavior of inpatient non-ICU glycemic data sets. The decision to transform glucose data could influence the interpretation and conclusions about the status of inpatient glycemic control. Further study is required to determine whether transformed versus nontransformed data influence clinical decisions or evaluation of interventions.

  20. Assessing the performance of handheld glucose testing for critical care.

    PubMed

    Kost, Gerald J; Tran, Nam K; Louie, Richard F; Gentile, Nicole L; Abad, Victor J

    2008-12-01

    We assessed the performance of a point-of-care (POC) glucose meter system (GMS) with multitasking test strip by using the locally-smoothed (LS) median absolute difference (MAD) curve method in conjunction with a modified Bland-Altman difference plot and superimposed International Organization for Standardization (ISO) 15197 tolerance bands. We analyzed performance for tight glycemic control (TGC). A modified glucose oxidase enzyme with a multilayer-gold, multielectrode, four-well test strip (StatStriptrade mark, NOVA Biomedical, Waltham, MA) was used. There was no test strip calibration code. Pragmatic comparison was done of GMS results versus paired plasma glucose measurements from chemistry analyzers in clinical laboratories. Venous samples (n = 1,703) were analyzed at 35 hospitals that used 20 types of chemistry analyzers. Erroneous results were identified using the Bland-Altman plot and ISO 15197 criteria. Discrepant values were analyzed for the TGC interval of 80-110 mg/dL. The GMS met ISO 15197 guidelines; 98.6% (410 of 416) of observations were within tolerance for glucose <75 mg/dL, and for > or =75 mg/dL, 100% were within tolerance. Paired differences (handheld minus reference) averaged -2.2 (SD 9.8) mg/dL; the median was -1 (range, -96 to 45) mg/dL. LS MAD curve analysis revealed satisfactory performance below 186 mg/dL; above 186 mg/dL, the recommended error tolerance limit (5 mg/dL) was not met. No discrepant values appeared. All points fell in Clarke Error Grid zone A. Linear regression showed y = 1.018x - 0.716 mg/dL, and r2 = 0.995. LS MAD curves draw on human ability to discriminate performance visually. LS MAD curve and ISO 15197 performance were acceptable for TGC. POC and reference glucose calibration should be harmonized and standardized.

  1. Evidence of extensive plasma glucose recycling following a glucose load in seabass.

    PubMed

    Rito, João; Viegas, Ivan; Pardal, Miguel A; Jones, John G

    2017-09-01

    Seabass and other carnivorous fish are highly dependent on gluconeogenesis from dietary amino acids to maintain glycemia. Glucose recycling (glucose→C3-intermediate→glucose) may potentiate the effects of glucose administration in sparing amino acid gluconeogenesis. To date, very few measurements of glucose recycling have been reported in fish. Thus, to determine the extent of glucose recycling following a glycemic challenge, juvenile seabass were given an intraperitoneal glucose load (2gkg -1 ) enriched with [U- 13 C]glucose. 13 C NMR analysis of plasma glucose 13 C-isotopomers was used to determine the fractional contributions of glucose derived directly from the load versus that from glucose recycling at 48h after the load. Both fed and 21-day fasted fish (20 per condition) were studied. In fasted fish, 18±4% of plasma glucose was directly derived from the load while 13±2% was derived from glucose recycling. In fed fish, the load accounted for 6±1% of plasma glucose levels while glucose recycling contributed 16±4%. 13 C NMR analysis of plasma lactate revealed 13 C-isotopomers corresponding to the expected C3-intermediates of peripheral [U- 13 C]glucose catabolism indicating that circulating lactate was a key intermediate in glucose carbon recycling under these conditions. In conclusion, glucose recycling was shown to contribute a significant portion of plasma glucose levels in both fed and fasted seabass 48h after an intraperitoneal glucose challenge and circulating lactate was shown to be an intermediate of this pathway. Copyright © 2017. Published by Elsevier Inc.

  2. Effects of vanadium supplementation on performance, some plasma metabolites and glucose metabolism in Mahabadi goat kids.

    PubMed

    Zarqami, A; Ganjkhanlou, M; Zali, A; Rezayazdi, K; Jolazadeh, A R

    2018-04-01

    This experiment was conducted to investigate the effects of vanadium (V) supplementation on performance, some plasma metabolites (cholesterol and triglycerides) and glucose metabolism in Mahabadi goat kids. Twenty-eight male kids (15 ± 2 kg body weight) were fed for 14 weeks in a completely randomized design with four treatments. Treatments were supplemented with 0 (control), 1, 2, and 3 mg V as vanadyl sulfate/animal/daily. On day 70, an intravenous glucose tolerance test (IVGTT) was conducted. Dry matter intake did not change by V supplementation, but adding V quadraticaly improved feed efficiency (p = .03) and tended to increase average daily gain (Quadratic, p = .09). Blood metabolites were unaffected by V supplementation, except for concentration of glucose in plasma, which decreased linearly as supplemental V level increased (p = .02). Plasma glucose concentrations at 15, 30, 45 and 60 min after glucose infusion were decreased in a quadratic fashion in response to increasing supplemental V level (p < .01). The IVGTT indicated that the kids supplemented with 2 mg V had higher glucose clearance rate (K) and lower glucose half-life (T ½ ; p < .05). Glucose area under the response curve from 0 to 60 min and 0 to 180 min after glucose infusion were decreased linearly (p = .04) by supplemental V. The results suggested that moderate supplementation of V may improve glucose utilization and feed efficiency in fattening kids. © 2017 Blackwell Verlag GmbH.

  3. A comparative effectiveness analysis of three continuous glucose monitors.

    PubMed

    Damiano, Edward R; El-Khatib, Firas H; Zheng, Hui; Nathan, David M; Russell, Steven J

    2013-02-01

    To compare three continuous glucose monitoring (CGM) devices in subjects with type 1 diabetes under closed-loop blood glucose (BG) control. Six subjects with type 1 diabetes (age 52 ± 14 years, diabetes duration 32 ± 14 years) each participated in two 51-h closed-loop BG control experiments in the hospital. Venous plasma glucose (PG) measurements (GlucoScout, International Biomedical) obtained every 15 min (2,360 values) were paired in time with corresponding CGM glucose (CGMG) measurements obtained from three CGM devices, the Navigator (Abbott Diabetes Care), the Seven Plus (DexCom), and the Guardian (Medtronic), worn simultaneously by each subject. Errors in paired PG-CGMG measurements and data reporting percentages were obtained for each CGM device. The Navigator had the best overall accuracy, with an aggregate mean absolute relative difference (MARD) of all paired points of 11.8 ± 11.1% and an average MARD across all 12 experiments of 11.8 ± 3.8%. The Seven Plus and Guardian produced aggregate MARDs of all paired points of 16.5 ± 17.8% and 20.3 ± 18.0%, respectively, and average MARDs across all 12 experiments of 16.5 ± 6.7% and 20.2 ± 6.8%, respectively. Data reporting percentages, a measure of reliability, were 76% for the Seven Plus and nearly 100% for the Navigator and Guardian. A comprehensive head-to-head-to-head comparison of three CGM devices for BG values from 36 to 563 mg/dL revealed marked differences in performance characteristics that include accuracy, precision, and reliability. The Navigator outperformed the other two in these areas.

  4. Ultrafiltration characteristics of glucose polymers with low polydispersity.

    PubMed

    Leypoldt, John K; Hoff, Catherine M; Piscopo, Dean; Carr, Seraya N; Svatek, Jessica M; Holmes, Clifford J

    2013-01-01

    Icodextrin, a glucose polymer with a polydispersity [ratio of weight-average molecular weight (Mw) to number-average molecular weight] of approximately 2.6, has been shown, compared with glucose, to provide superior ultrafiltration (UF) efficiency [ratio of UF to carbohydrate (CHO) absorbed] when used as an osmotic agent during a long-dwell peritoneal dialysis exchange. In an experimental rabbit model, we evaluated the effect of Mw on the UF and UF efficiency of glucose polymers with low polydispersity. A crossover trial in female New Zealand White rabbits (2.20 - 2.65 kg) with surgically implanted peritoneal catheters evaluated two glucose polymers at nominal concentrations of 7.5 g/dL: a 6K polymer (Mw: 6.4 kDa; polydispersity: 2.3) and a 19K polymer (Mw: 18.8 kDa; polydispersity: 2.0). Rabbits were randomized to receive either the 6K (n = 11) or the 19K (n = 12) solution during the first exchange (40 mL/kg body weight). The alternative solution was evaluated in a second exchange 3 days later. During each 4-hour dwell, the UF and total glucose polymer CHO absorbed were determined. The UF was higher for the 6K (p < 0.0001) than for the 19K polymer (mean ± standard deviation: 73.6 ± 30.8 mL vs. 43.0 ± 20.2 mL), as was the amount of CHO absorbed (42.5% ± 9.8% vs. 35.7% ± 11.0%, p = 0.021). In spite of higher CHO absorption, an approximately 50% higher (p = 0.029) UF efficiency was achieved with the 6K polymer (28.3 ± 18.8 mL/g) than with the 19K polymer (19.0 ± 11.3 mL/g). The results were independent of the order of the experimental exchanges. Glucose polymers with low polydispersity are effective osmotic agents in a rabbit model. The low-Mw polymer was more effective at generating UF and had a higher UF efficiency, but those results came at the expense of the polymer being more readily absorbed from the peritoneal cavity.

  5. Achieving direct electrochemistry of glucose oxidase by one step electrochemical reduction of graphene oxide and its use in glucose sensing.

    PubMed

    Shamsipur, Mojtaba; Tabrizi, Mahmoud Amouzadeh

    2014-12-01

    In this paper, the direct electrochemistry of glucose oxidase (GOD) was accomplished at a glassy carbon electrode modified with electrochemically reduced graphene oxide/sodium dodecyl sulfate (GCE/ERGO/SDS). A pair of reversible peaks is exhibited on GCE/ERGO/SDS/GOD by cyclic voltammetry. The peak-to-peak potential separation of immobilized GOD is 28 mV in 0.1 M phosphate buffer solution (pH7.0) with a scan rate of 50 mV/s. The average surface coverage is 2.62×10(-10) mol cm(-2). The resulting biosensor exhibited a good response to glucose with linear range from 1 to 8 mM (R(2)=0.9878), good reproducibility and detection limit of 40.8 μM. The results from the biosensor were similar (±5%) to those obtained from the clinical analyzer. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. The effect of an instant hand sanitizer on blood glucose monitoring results.

    PubMed

    Mahoney, John J; Ellison, John M; Glaeser, Danielle; Price, David

    2011-11-01

    People with diabetes mellitus are instructed to clean their skin prior to self-monitoring of blood glucose to remove any dirt or food residue that might affect the reading. Alcohol-based hand sanitizers have become popular when soap and water are not available. The aim of this study was to determine whether a hand sanitizer is compatible with glucose meter testing and effective for the removal of exogenous glucose. We enrolled 34 nonfasting subjects [14 male/20 female, mean ages 45 (standard deviation, 9.4)] years, 2 with diagnosed diabetes/32 without known diabetes]. Laboratory personnel prepared four separate fingers on one hand of each subject by (1) cleaning the second finger with soap and water and towel drying (i.e., control finger), (2) cleaning the third finger with an alcohol-based hand sanitizer, (3) coating the fourth finger with cola and allowing it to air dry, and (4) coating the fifth finger with cola and then cleaning it with the instant hand sanitizer after the cola had dried. Finger sticks were performed on each prepared finger and blood glucose was measured. Several in vitro studies were also performed to investigate the effectiveness of the hand sanitizer for removal of exogenous glucose.z Mean blood glucose values from fingers cleaned with instant hand sanitizer did not differ significantly from the control finger (p = .07 and .08, respectively) and resulted in 100% accurate results. Blood glucose data from the fourth (cola-coated) finger were substantially higher on average compared with the other finger conditions, but glucose data from the fifth finger (cola-coated then cleaned with hand sanitizer) was similar to the control finger. The data from in vitro experiments showed that the hand sanitizer did not adversely affect glucose meter results, but when an exogenous glucose interference was present, the effectiveness of the hand sanitizer on glucose bias (range: 6% to 212%) depended on the surface area and degree of dilution. In our study

  7. The Effect of an Instant Hand Sanitizer on Blood Glucose Monitoring Results

    PubMed Central

    Mahoney, John J; Ellison, John M; Glaeser, Danielle; Price, David

    2011-01-01

    Background People with diabetes mellitus are instructed to clean their skin prior to self-monitoring of blood glucose to remove any dirt or food residue that might affect the reading. Alcohol-based hand sanitizers have become popular when soap and water are not available. The aim of this study was to determine whether a hand sanitizer is compatible with glucose meter testing and effective for the removal of exogenous glucose. Methods We enrolled 34 nonfasting subjects [14 male/20 female, mean ages 45 (standard deviation, 9.4)] years, 2 with diagnosed diabetes/32 without known diabetes]. Laboratory personnel prepared four separate fingers on one hand of each subject by (1) cleaning the second finger with soap and water and towel drying (i.e., control finger), (2) cleaning the third finger with an alcohol-based hand sanitizer, (3) coating the fourth finger with cola and allowing it to air dry, and (4) coating the fifth finger with cola and then cleaning it with the instant hand sanitizer after the cola had dried. Finger sticks were performed on each prepared finger and blood glucose was measured. Several in vitro studies were also performed to investigate the effectiveness of the hand sanitizer for removal of exogenous glucose.z Results Mean blood glucose values from fingers cleaned with instant hand sanitizer did not differ significantly from the control finger (p = .07 and .08, respectively) and resulted in 100% accurate results. Blood glucose data from the fourth (cola-coated) finger were substantially higher on average compared with the other finger conditions, but glucose data from the fifth finger (cola-coated then cleaned with hand sanitizer) was similar to the control finger. The data from in vitro experiments showed that the hand sanitizer did not adversely affect glucose meter results, but when an exogenous glucose interference was present, the effectiveness of the hand sanitizer on glucose bias (range: 6% to 212%) depended on the surface area and degree of

  8. Transcutaneous blood glucose monitoring system based on an ISFET glucose sensor and studies on diabetic patients.

    PubMed

    Ito, N; Saito, A; Kayashima, S; Kimura, J; Kuriyama, T; Nagata, N; Arai, T; Kikuchi, M

    1995-01-01

    A transcutaneous blood glucose monitoring system consists of an ion-sensitive field-effect transistor (ISFET) glucose sensor unit and a suction effusion fluid (SEF) collecting unit. The SEF is directly collected by a weak suction (400 mmHg absolute pressure) through the skin from which the corneum layer of the epidermis has been previously removed. An ISFET glucose sensor unit is able to measure glucose concentrations in a microliter order sampling volume. The system was applied to three diabetic patients during a 75 g oral glucose tolerance test for monitoring blood glucose levels. During the experiments, glucose changes in the SEF followed actual blood glucose levels with 10 min delays. Results suggest the feasibility of utilizing quasi-continuous, transcutaneous blood glucose monitoring for individual patients with various diabetic histories or diabetic complications.

  9. Clonazepam increases in vivo striatal extracellular glucose in diabetic rats after glucose overload.

    PubMed

    Gomez, Rosane; Barros, Helena M T

    2003-12-01

    Hyperglycemia modulates brain function, including neuronal excitability, neurotransmitter release and behavioral changes. There may be connections between the GABAergic system, glucose sensing neurons and glucose in the neuronal environment that shed light on the mechanism by which GABA(A) agents influence depressive behavior in diabetic rats submitted to the forced swimming test. We aimed to investigate whether clonazepam (CNZ), a GABA(A) receptor positive modulator, modifies in vivo striatal extracellular glucose levels in diabetic rats under fasting condition or after oral glucose overload. Streptozotocin diabetic and nondiabetic rats were submitted to in vivo striatal microdialysis. Perfusate samples were collected at baseline, during fasting and following administration of CNZ (0.25 mg/kg) and oral glucose overload. Blood glucose and striatal extracellular glucose were measured simultaneously at several time points. Fasting striatal glucose levels were higher in diabetic than in nondiabetic rats and the differences between these animals were maintained after glucose overload. The increases in extracellular striatal glucose after glucose overload were around 40% and blood to brain transference was decreased in diabetics. CNZ treatment paradoxically increased striatal glucose after glucose overload in diabetic rats, which may mark the dysfunction in brain glucose homeostasis.

  10. Glucose transport in brain - effect of inflammation.

    PubMed

    Jurcovicova, J

    2014-01-01

    Glucose is transported across the cell membrane by specific saturable transport system, which includes two types of glucose transporters: 1) sodium dependent glucose transporters (SGLTs) which transport glucose against its concentration gradient and 2) sodium independent glucose transporters (GLUTs), which transport glucose by facilitative diffusion in its concentration gradient. In the brain, both types of transporters are present with different function, affinity, capacity, and tissue distribution. GLUT1 occurs in brain in two isoforms. The more glycosylated GLUT1 is produced in brain microvasculature and ensures glucose transport across the blood brain barrier (BBB). The less glycosylated form is localized in astrocytic end-feet and cell bodies and is not present in axons, neuronal synapses or microglia. Glucose transported to astrocytes by GLUT1 is metabolized to lactate serving to neurons as energy source. Proinflammatory cytokine interleukin (IL)-1β upregulates GLUT1 in endothelial cells and astrocytes, whereas it induces neuronal death in neuronal cell culture. GLUT2 is present in hypothalamic neurons and serves as a glucose sensor in regulation of food intake. In neurons of the hippocampus, GLUT2 is supposed to regulate synaptic activity and neurotransmitter release. GLUT3 is the most abundant glucose transporter in the brain having five times higher transport capacity than GLUT1. It is present in neuropil, mostly in axons and dendrites. Its density and distribution correlate well with the local cerebral glucose demands. GLUT5 is predominantly fructose transporter. In brain, GLUT5 is the only hexose transporter in microglia, whose regulation is not yet clear. It is not present in neurons. GLUT4 and GLUT8 are insulin-regulated glucose transporters in neuronal cell bodies in the cortex and cerebellum, but mainly in the hippocampus and amygdala, where they maintain hippocampus-dependent cognitive functions. Insulin translocates GLUT4 from cytosol to plasma

  11. Analytical Performance Evaluation of Infopia Element™ Auto-coding Blood Glucose Monitoring System for Self-Monitoring of Blood Glucose.

    PubMed

    Park, Hae-Il; Lee, Seong-Su; Son, Jang-Won; Kwon, Hee-Sun; Kim, Sung Rae; Chae, Hyojin; Kim, Myungshin; Kim, Yonggoo; Yoo, Soonjib

    2016-11-01

    Element™ Auto-coding Blood Glucose Monitoring System (BGMS; Infopia Co., Ltd., Anyang-si, Korea) was developed for self-monitoring of blood glucose (SMBG). Precision, linearity, and interference were tested. Eighty-four capillary blood samples measured by Element™ BGMS were compared with central laboratory method (CLM) results in venous serum. Accuracy was evaluated using ISO 15197:2013 criteria. Coefficients of variation (CVs; mean) were 2.4% (44.2 mg/dl), 3.7% (100.6 mg/dl), and 2.1% (259.8 mg/dl). Linearity was shown at concentrations 39.25-456.25 mg/l (y = 0.989 + 0.984x, SE = 17.63). Up to 15 mg/dl of galactose, ascorbic acid, and acetaminophen, interference > 10.4% was not observed. Element™ BGMS glucose was higher than CLM levels by 3.2 mg/dl (at 200 mg/dl) to 8.2 mg/dl (at 100 mg/dl). The minimum specification for bias (3.3%) was met at 140 and 200 mg/l glucose. In the Clarke and consensus error grids, 100% of specimens were within zone A and B. For Element™ BGMS values, 92.9% (78/84) to 94.0% (79/84) were within a 15 mg/dl (< 100 mg/dl) or 15% (> 100 mg/dl) of the average CLM value. Element™ BGMS was considered an appropriate SMBG for home use; however, the positive bias at low-to-mid glucose levels requires further improvement. © 2016 Wiley Periodicals, Inc.

  12. Water and glucose gradients in the substrate measured with NMR imaging during solid-state fermentation with Aspergillus oryzae.

    PubMed

    Nagel, Frank-Jan; Van As, Henk; Tramper, Johannes; Rinzema, Arjen

    2002-09-20

    Gradients inside substrate particles cannot be prevented in solid-state fermentation. These gradients can have a strong effect on the physiology of the microorganisms but have hitherto received little attention in experimental studies. We report gradients in moisture and glucose content during cultivation of Aspergillus oryzae on membrane-covered wheat-dough slices that were calculated from (1)H-NMR images. We found that moisture gradients in the solid substrate remain small when evaporation is minimized. This is corroborated by predictions of a diffusion model. In contrast, strong glucose gradients developed. Glucose concentrations just below the fungal mat remained low due to high glucose uptake rates, but deeper in the matrix glucose accumulated to very high levels. Integration of the glucose profile gave an average concentration close to the measured average content. On the basis of published data, we expect that the glucose levels in the matrix cause a strong decrease in water activity. The results demonstrate that NMR can play an important role in quantitative analysis of water and glucose gradients at the particle level during solid-state fermentation, which is needed to improve our understanding of the response of fungi to this nonconventional fermentation environment. Copyright 2002 Wiley Periodicals, Inc.

  13. FRET-based glucose monitoring for bioprocessing

    NASA Astrophysics Data System (ADS)

    Bartolome, Amelita; Smalls-Mantey, Lauren; Lin, Debora; Rao, Govind; Tolosa, Leah

    2006-02-01

    The glucose-mediated conformational changes in the glucose binding protein (GBP) have been exploited in the development of fluorescence based glucose sensors. The fluorescence response is generated by a polarity sensitive dye attached to a specific site. Such fluorescent sensors respond to submicromolar glucose at diffusion-controlled rates mimicking the wild type. However, such sensors have been limited to in vitro glucose sensing because of the preliminary dye-labeling step. In the study described here, the dye-labeling step is omitted by genetically encoding the GBP with two green fluorescent mutants namely, the green fluorescent protein (GFP) and the yellow fluorescent protein (YFP) in the N- and C-terminal ends, respectively. These two GFP mutants comprise a fluorescence resonance energy transfer (FRET) donor and acceptor pair. Thus, when glucose binds with GBP, the conformational changes affect the FRET efficiency yielding a dose-dependent response. A potential application for this FRET-based glucose biosensor is online glucose sensing in bioprocessing and cell culture. This was demonstrated by the measurement of glucose consumption in yeast fermentation. Further development of this system should yield in vivo measurement of glucose in bioprocesses.

  14. Blood glucose level reconstruction as a function of transcapillary glucose transport.

    PubMed

    Koutny, Tomas

    2014-10-01

    A diabetic patient occasionally undergoes a detailed monitoring of their glucose levels. Over the course of a few days, a monitoring system provides a detailed track of their interstitial fluid glucose levels measured in their subcutaneous tissue. A discrepancy in the blood and interstitial fluid glucose levels is unimportant because the blood glucose levels are not measured continuously. Approximately five blood glucose level samples are taken per day, and the interstitial fluid glucose level is usually measured every 5min. An increased frequency of blood glucose level sampling would cause discomfort for the patient; thus, there is a need for methods to estimate blood glucose levels from the glucose levels measured in subcutaneous tissue. The Steil-Rebrin model is widely used to describe the relationship between blood and interstitial fluid glucose dynamics. However, we measured glucose level patterns for which the Steil-Rebrin model does not hold. Therefore, we based our research on a different model that relates present blood and interstitial fluid glucose levels to future interstitial fluid glucose levels. Using this model, we derived an improved model for calculating blood glucose levels. In the experiments conducted, this model outperformed the Steil-Rebrin model while introducing no additional requirements for glucose sample collection. In subcutaneous tissue, 26.71% of the calculated blood glucose levels had absolute values of relative differences from smoothed measured blood glucose levels less than or equal to 5% using the Steil-Rebrin model. However, the same difference interval was encountered in 63.01% of the calculated blood glucose levels using the proposed model. In addition, 79.45% of the levels calculated with the Steil-Rebrin model compared with 95.21% of the levels calculated with the proposed model had 20% difference intervals. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Coping with an exogenous glucose overload: glucose kinetics of rainbow trout during graded swimming

    PubMed Central

    Choi, Kevin

    2015-01-01

    This study examines how chronically hyperglycemic rainbow trout modulate glucose kinetics in response to graded exercise up to critical swimming speed (Ucrit), with or without exogenous glucose supply. Our goals were 1) to quantify the rates of hepatic glucose production (Ra glucose) and disposal (Rd glucose) during graded swimming, 2) to determine how exogenous glucose affects the changes in glucose fluxes caused by exercise, and 3) to establish whether exogenous glucose modifies Ucrit or the cost of transport. Results show that graded swimming causes no change in Ra and Rd glucose at speeds below 2.5 body lengths per second (BL/s), but that glucose fluxes may be stimulated at the highest speeds. Excellent glucoregulation is also achieved at all exercise intensities. When exogenous glucose is supplied during exercise, trout suppress hepatic production from 16.4 ± 1.6 to 4.1 ± 1.7 μmol·kg−1·min−1 and boost glucose disposal to 40.1 ± 13 μmol·kg−1·min−1. These responses limit the effects of exogenous glucose to a 2.5-fold increase in glycemia, whereas fish showing no modulation of fluxes would reach dangerous levels of 114 mM of blood glucose. Exogenous glucose reduces metabolic rate by 16% and, therefore, causes total cost of transport to decrease accordingly. High glucose availability does not improve Ucrit because the fish are unable to take advantage of this extra fuel during maximal exercise and rely on tissue glycogen instead. In conclusion, trout have a remarkable ability to adjust glucose fluxes that allows them to cope with the cumulative stresses of a glucose overload and graded exercise. PMID:26719305

  16. Coping with an exogenous glucose overload: glucose kinetics of rainbow trout during graded swimming.

    PubMed

    Choi, Kevin; Weber, Jean-Michel

    2016-03-15

    This study examines how chronically hyperglycemic rainbow trout modulate glucose kinetics in response to graded exercise up to critical swimming speed (Ucrit), with or without exogenous glucose supply. Our goals were 1) to quantify the rates of hepatic glucose production (Ra glucose) and disposal (Rd glucose) during graded swimming, 2) to determine how exogenous glucose affects the changes in glucose fluxes caused by exercise, and 3) to establish whether exogenous glucose modifies Ucrit or the cost of transport. Results show that graded swimming causes no change in Ra and Rd glucose at speeds below 2.5 body lengths per second (BL/s), but that glucose fluxes may be stimulated at the highest speeds. Excellent glucoregulation is also achieved at all exercise intensities. When exogenous glucose is supplied during exercise, trout suppress hepatic production from 16.4 ± 1.6 to 4.1 ± 1.7 μmol·kg(-1)·min(-1) and boost glucose disposal to 40.1 ± 13 μmol·kg(-1)·min(-1). These responses limit the effects of exogenous glucose to a 2.5-fold increase in glycemia, whereas fish showing no modulation of fluxes would reach dangerous levels of 114 mM of blood glucose. Exogenous glucose reduces metabolic rate by 16% and, therefore, causes total cost of transport to decrease accordingly. High glucose availability does not improve Ucrit because the fish are unable to take advantage of this extra fuel during maximal exercise and rely on tissue glycogen instead. In conclusion, trout have a remarkable ability to adjust glucose fluxes that allows them to cope with the cumulative stresses of a glucose overload and graded exercise. Copyright © 2016 the American Physiological Society.

  17. [PROGNOSTIC SIGNIFICANCE OF CHANGES OF BLOOD GLUCOSE LEVEL IN PATIENTS WITH THORACOABDOMINAL INJURIES.

    PubMed

    Sorokin, E P; Ponomarev, S V; Shilyaeva, Ye V; Bel'skih, Ye A; Gritsan, A I

    2016-07-01

    Background Currently, one of the causes of high morbidity and mortality is injuries. Predict the outcome of injuries - it is an important task of the treating physician. Trauma is a stress factor so to predict the outcome, you can use markers of stress, the most accessible ofwhich is blood glucose. to reveal the dynamics of the relationship between blood glucose levels and the outlook for the life ofpatients with thoracoabdominal injuries. A retrospective analysis of medical records of hospitalized patients were divided into two groups, depending on the outlook for the life of (favorable or unfavorable), and each of the groups - into two subgroups according to the presence or absence of signs of intoxication at admission. The subgroups were calculated and compared the mean blood glucose levels at different hours of hospital treatment. It was found that the average blood glucose levels at various hours of hospital stay were significantly higher in patients with poor outcome. The most noticeable was the difference in the first days of hospital treatment. Signs of intoxication was associated with lower values of glucose and a tendency to hypoglycaemia. In addition, among patients with high blood glucose ( 8 mg / dL) was observed over deaths in the first day of hospital stay. High blood glucose levels ( 8,0 mmol / L) in the first day of hospital treatment is a predictor ofpoor outcome in patients with thoracoabdominal injuries.

  18. Mechanisms and time course of impaired skeletal muscle glucose transport activity in streptozocin diabetic rats.

    PubMed Central

    Napoli, R; Hirshman, M F; Horton, E S

    1995-01-01

    Skeletal muscle glucose transport is altered in diabetes in humans, as well as in rats. To investigate the mechanisms of this abnormality, we measured glucose transport Vmax, the total transporter number, their average intrinsic activity, GLUT4 and GLUT1 contents in skeletal muscle plasma membrane vesicles from basal or insulin-stimulated streptozocin diabetic rats with different duration of diabetes, treated or not with phlorizin. The glucose transport Vmax progressively decreased with the duration of diabetes. In the basal state, this decrease was primarily associated with the reduction of transporter intrinsic activity, which appeared earlier than any change in transporter number or GLUT4 and GLUT1 content. In the insulin-stimulated state, the decrease of transport was mainly associated with severe defects in transporter translocation. Phlorizin treatment partially increased the insulin-stimulated glucose transport by improving the transporter translocation defects. In conclusion, in streptozocin diabetes (a) reduction of intrinsic activity plays a major and early role in the impairment of basal glucose transport; (b) a defect in transporter translocation is the mechanism responsible for the decrease in insulin-stimulated glucose transport; and (c) hyperglycemia per se affects the insulin-stimulated glucose transport by altering the transporter translocation. PMID:7615815

  19. Synergistic binding of glucose and aluminium ATP to hexokinase from Saccharomyces cerevisiae.

    PubMed

    Woolfitt, A R; Kellett, G L; Hoggett, J G

    1988-08-10

    The binding of glucose, AlATP and AlADP to the monomeric and dimeric forms of the native yeast hexokinase PII isoenzyme and to the proteolytically modified SII monomeric form was monitored at pH 6.7 by the concomitant quenching of intrinsic protein fluorescence. No fluorescence changes were observed when free enzyme was mixed with AlATP at concentrations up to 7500 microM. In the presence of saturating concentrations of glucose, the maximal quenching of fluorescence induced by AlATP was between 1.5 and 3.5% depending on species, and the average value of [L]0.5, the concentration of ligand at half-saturation, over all monomeric species was 0.9 +/- 0.4 microM. The presence of saturating concentrations of AlATP diminished [L]0.5 for glucose binding by between 260- and 670-fold for hexokinase PII and SII monomers, respectively (dependent on the ionic strength), and by almost 4000-fold for PII dimer. The data demonstrate extremely strong synergistic interactions in the binding of glucose and AlATP to yeast hexokinase, arising as a consequence of conformational changes in the free enzyme induced by glucose and in enzyme-glucose complex induced by AlATP. The synergistic interactions of glucose and AlATP are related to their kinetic synergism and to the ability of AlATP to act as a powerful inhibitor of the hexokinase reaction.

  20. Detection of hypoglycemia with continuous interstitial and traditional blood glucose monitoring using the FreeStyle Navigator Continuous Glucose Monitoring System.

    PubMed

    McGarraugh, Geoffrey; Bergenstal, Richard

    2009-03-01

    The objective of the analysis was to compare detection of hypoglycemic episodes (glucose <70 mg/dL lasting >15 min) with the FreeStyle Navigator Continuous Glucose Monitoring System (FSN-CGM) (Abbott Diabetes Care, Alameda, CA) alarms to detection with traditional finger stick testing at an average frequency of eight tests per day. The performance of FSN-CGM alarms was evaluated in a clinic setting using 58 subjects with type 1 diabetes mellitus (T1DM) monitoring interstitial glucose concentration over a 5-day period compared to reference YSI measurements (instrument manufactured by YSI, Yellow Springs, OH) at 15-min intervals. Finger stick glucose testing was evaluated in the home environment with 91 subjects with TIDM monitoring with the blood glucose meter integrated into the FreeStyle Navigator (FSN-BG) over a 20-day period. The reference was FSN-CGM with results masked from the subjects. Blood glucose values <=85 mg/dL were considered the optimal treatment level to avoid or reverse hypoglycemia. With a threshold alarm setting of 85 mg/dL, 90.6% of hypoglycemic episodes were detected within +/- 30 min by FSN-CGM in the clinic study. When the alarm was activated, YSI glucose was <= 85 mg/dL 77.2% of the time. In the home environment, the average FSN-BG testing frequency was 7.9 tests per day. Hypoglycemia was verified within +/- 30 min by FSN-BG measurements <= 85 mg/dL at a rate of 27.5%. Even with a high rate of FSN-BG testing, hypoglycemia detected by FSN-CGM was verified by patients with T1DM very infrequently. A high rate of hypoglycemia detection with a moderate rate of unnecessary alarms can be attained using FSN-CGM.

  1. Regulation of Blood Glucose by Hypothalamic Pyruvate Metabolism

    NASA Astrophysics Data System (ADS)

    Lam, Tony K. T.; Gutierrez-Juarez, Roger; Pocai, Alessandro; Rossetti, Luciano

    2005-08-01

    The brain keenly depends on glucose for energy, and mammalians have redundant systems to control glucose production. An increase in circulating glucose inhibits glucose production in the liver, but this negative feedback is impaired in type 2 diabetes. Here we report that a primary increase in hypothalamic glucose levels lowers blood glucose through inhibition of glucose production in rats. The effect of glucose requires its conversion to lactate followed by stimulation of pyruvate metabolism, which leads to activation of adenosine triphosphate (ATP)-sensitive potassium channels. Thus, interventions designed to enhance the hypothalamic sensing of glucose may improve glucose homeostasis in diabetes.

  2. Trait valence and the better-than-average effect.

    PubMed

    Gold, Ron S; Brown, Mark G

    2011-12-01

    People tend to regard themselves as having superior personality traits compared to their average peer. To test whether this "better-than-average effect" varies with trait valence, participants (N = 154 students) rated both themselves and the average student on traits constituting either positive or negative poles of five trait dimensions. In each case, the better-than-average effect was found, but trait valence had no effect. Results were discussed in terms of Kahneman and Tversky's prospect theory.

  3. 76 FR 6161 - Annual Determination of Average Cost of Incarceration

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-03

    ... AGENCY: Bureau of Prisons, Justice. ACTION: Notice. SUMMARY: The fee to cover the average cost of...: 28 CFR part 505 allows for assessment and collection of a fee to cover the average cost of... Prisons determined that, based upon fiscal year 2009 data, the fee to cover the average cost of...

  4. 76 FR 57081 - Annual Determination of Average Cost of Incarceration

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-15

    ... AGENCY: Bureau of Prisons, Justice. ACTION: Notice. SUMMARY: The fee to cover the average cost of... INFORMATION: 28 CFR part 505 allows for assessment and collection of a fee to cover the average cost of... Prisons determined that, based upon fiscal year 2010 data, the fee to cover the average cost of...

  5. 47 CFR 1.959 - Computation of average terrain elevation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Section 1.959 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Wireless..., average terrain elevation must be calculated by computer using elevations from a 30 second point or better..., if the results differ significantly from the computer derived averages. (a) Radial average terrain...

  6. 47 CFR 1.959 - Computation of average terrain elevation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Section 1.959 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Wireless..., average terrain elevation must be calculated by computer using elevations from a 30 second point or better..., if the results differ significantly from the computer derived averages. (a) Radial average terrain...

  7. 20 CFR 404.221 - Computing your average monthly wage.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... your average monthly wage, we consider all the wages, compensation, self-employment income, and deemed... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Computing your average monthly wage. 404.221... DISABILITY INSURANCE (1950- ) Computing Primary Insurance Amounts Average-Monthly-Wage Method of Computing...

  8. 7 CFR 1410.44 - Average adjusted gross income.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Average adjusted gross income. 1410.44 Section 1410... Average adjusted gross income. (a) Benefits under this part will not be available to persons or legal entities whose average adjusted gross income exceeds $1,000,000 or as further specified in part 1400...

  9. 7 CFR 1410.44 - Average adjusted gross income.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Average adjusted gross income. 1410.44 Section 1410... Average adjusted gross income. (a) Benefits under this part will not be available to persons or legal entities whose average adjusted gross income exceeds $1,000,000 or as further specified in part 1400...

  10. 20 CFR 404.221 - Computing your average monthly wage.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... your average monthly wage, we consider all the wages, compensation, self-employment income, and deemed... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false Computing your average monthly wage. 404.221... DISABILITY INSURANCE (1950- ) Computing Primary Insurance Amounts Average-Monthly-Wage Method of Computing...

  11. 7 CFR 760.640 - National average market price.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false National average market price. 760.640 Section 760.640....640 National average market price. (a) The Deputy Administrator will establish the National Average Market Price (NAMP) using the best sources available, as determined by the Deputy Administrator, which...

  12. Sample Size Bias in Judgments of Perceptual Averages

    ERIC Educational Resources Information Center

    Price, Paul C.; Kimura, Nicole M.; Smith, Andrew R.; Marshall, Lindsay D.

    2014-01-01

    Previous research has shown that people exhibit a sample size bias when judging the average of a set of stimuli on a single dimension. The more stimuli there are in the set, the greater people judge the average to be. This effect has been demonstrated reliably for judgments of the average likelihood that groups of people will experience negative,…

  13. 7 CFR 51.2561 - Average moisture content.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Average moisture content. 51.2561 Section 51.2561... STANDARDS) United States Standards for Grades of Shelled Pistachio Nuts § 51.2561 Average moisture content. (a) Determining average moisture content of the lot is not a requirement of the grades, except when...

  14. Averaging in SU(2) open quantum random walk

    NASA Astrophysics Data System (ADS)

    Clement, Ampadu

    2014-03-01

    We study the average position and the symmetry of the distribution in the SU(2) open quantum random walk (OQRW). We show that the average position in the central limit theorem (CLT) is non-uniform compared with the average position in the non-CLT. The symmetry of distribution is shown to be even in the CLT.

  15. Incretin responses to oral glucose and mixed meal tests and changes in fasting glucose levels during 7 years of follow-up: The Hoorn Meal Study.

    PubMed

    Koopman, A D M; Rutters, F; Rauh, S P; Nijpels, G; Holst, J J; Beulens, J W; Alssema, M; Dekker, J M

    2018-01-01

    We conducted the first prospective observational study in which we examined the association between incretin responses to an oral glucose tolerance test (OGTT) and mixed meal test (MMT) at baseline and changes in fasting glucose levels 7 years later, in individuals who were non-diabetic at baseline. We used data from the Hoorn Meal Study; a population-based cohort study among 121 subjects, aged 61.0±6.7y. GIP and GLP-1 responses were determined at baseline and expressed as total and incremental area under the curve (tAUC and iAUC). The association between incretin response at baseline and changes in fasting glucose levels was assessed using linear regression. The average change in glucose over 7 years was 0.43 ± 0.5 mmol/l. For GIP, no significant associations were observed with changes in fasting glucose levels. In contrast, participants within the middle and highest tertile of GLP-1 iAUC responses to OGTT had significantly smaller increases (actually decreases) in fasting glucose levels; -0.28 (95% confidence interval: -0.54;-0.01) mmol/l and -0.39 (-0.67;-0.10) mmol/l, respectively, compared to those in the lowest tertile. The same trend was observed for tAUC GLP-1 following OGTT (highest tertile: -0.32 (0.61;-0.04) mmol/l as compared to the lowest tertile). No significant associations were observed for GLP-1 responses following MMT. In conclusion, within our non-diabetic population-based cohort, a low GLP-1 response to OGTT was associated with a steeper increase in fasting glucose levels during 7 years of follow-up. This suggests that a reduced GLP-1 response precedes glucose deterioration and may play a role in the etiology of type 2 diabetes mellitus.

  16. Incretin responses to oral glucose and mixed meal tests and changes in fasting glucose levels during 7 years of follow-up: The Hoorn Meal Study

    PubMed Central

    Rutters, F.; Rauh, S. P.; Nijpels, G.; Holst, J. J.; Beulens, J. W.; Alssema, M.; Dekker, J. M.

    2018-01-01

    We conducted the first prospective observational study in which we examined the association between incretin responses to an oral glucose tolerance test (OGTT) and mixed meal test (MMT) at baseline and changes in fasting glucose levels 7 years later, in individuals who were non-diabetic at baseline. We used data from the Hoorn Meal Study; a population-based cohort study among 121 subjects, aged 61.0±6.7y. GIP and GLP-1 responses were determined at baseline and expressed as total and incremental area under the curve (tAUC and iAUC). The association between incretin response at baseline and changes in fasting glucose levels was assessed using linear regression. The average change in glucose over 7 years was 0.43 ± 0.5 mmol/l. For GIP, no significant associations were observed with changes in fasting glucose levels. In contrast, participants within the middle and highest tertile of GLP-1 iAUC responses to OGTT had significantly smaller increases (actually decreases) in fasting glucose levels; -0.28 (95% confidence interval: -0.54;-0.01) mmol/l and -0.39 (-0.67;-0.10) mmol/l, respectively, compared to those in the lowest tertile. The same trend was observed for tAUC GLP-1 following OGTT (highest tertile: -0.32 (0.61;-0.04) mmol/l as compared to the lowest tertile). No significant associations were observed for GLP-1 responses following MMT. In conclusion, within our non-diabetic population-based cohort, a low GLP-1 response to OGTT was associated with a steeper increase in fasting glucose levels during 7 years of follow-up. This suggests that a reduced GLP-1 response precedes glucose deterioration and may play a role in the etiology of type 2 diabetes mellitus. PMID:29324870

  17. Application of Semipermeable Membranes in Glucose Biosensing

    PubMed Central

    Kulkarni, Tanmay; Slaughter, Gymama

    2016-01-01

    Glucose biosensors have received significant attention in recent years due to the escalating mortality rate of diabetes mellitus. Although there is currently no cure for diabetes mellitus, individuals living with diabetes can lead a normal life by maintaining tight control of their blood glucose levels using glucose biosensors (e.g., glucometers). Current research in the field is focused on the optimization and improvement in the performance of glucose biosensors by employing a variety of glucose selective enzymes, mediators and semipermeable membranes to improve the electron transfer between the active center of the enzyme and the electrode substrate. Herein, we summarize the different semipermeable membranes used in the fabrication of the glucose biosensor, that result in improved biosensor sensitivity, selectivity, dynamic range, response time and stability. PMID:27983630

  18. Implantable fluorescence-based glucose sensor development

    NASA Astrophysics Data System (ADS)

    Ibey, Bennett L.; Yadavalli, Vamsi K.; Thomas, Hope R.; Rounds, Rebecca M.; Pishko, Michael V.; Cote, Gerard L.

    2005-03-01

    An implantable sensor is being created that allows measurement of blood glucose through fluorescent detection of an embedded chemical assay. The sensor is based on the competitive binding reaction between the protein Concanavalin A and various saccharide molecules, specifically a glycodendrimer and glucose. Previous studies have shown the ability of an embedded chemical assay using Con A and dextran with shorter wavelength dyes to both sense changes in glucose and generate sufficient fluorescent emission to pass through the dermal tissue. However, due to the chemical constituents of the assay, multivalent binding was evident resulting in poor spectral change due to glucose within the biological range. Use of a glycodendrimer and longer wavelength dyes has improved the sensor"s spectral change due to glucose and the overall signal to noise ratio of the sensor. In this work, a description of this sensor and the results obtained from it will be presented showing a large dynamic range of fluorescence with glucose.

  19. Blood glucose prediction using neural network

    NASA Astrophysics Data System (ADS)

    Soh, Chit Siang; Zhang, Xiqin; Chen, Jianhong; Raveendran, P.; Soh, Phey Hong; Yeo, Joon Hock

    2008-02-01

    We used neural network for blood glucose level determination in this study. The data set used in this study was collected using a non-invasive blood glucose monitoring system with six laser diodes, each laser diode operating at distinct near infrared wavelength between 1500nm and 1800nm. The neural network is specifically used to determine blood glucose level of one individual who participated in an oral glucose tolerance test (OGTT) session. Partial least squares regression is also used for blood glucose level determination for the purpose of comparison with the neural network model. The neural network model performs better in the prediction of blood glucose level as compared with the partial least squares model.

  20. Postprandial glucose response to selected tropical fruits in normal glucose-tolerant Nigerians.

    PubMed

    Edo, A; Eregie, A; Adediran, O; Ohwovoriole, A; Ebengho, S

    2011-01-01

    The glycemic response to commonly eaten fruits in Nigeria has not been reported. Therefore, this study assessed the plasma glucose response to selected fruits in Nigeria. Ten normal glucose-tolerant subjects randomly consumed 50 g carbohydrate portions of three fruits: banana (Musa paradisiaca), pineapple (Ananus comosus), and pawpaw (Carica papaya), and a 50-g glucose load at 1-week intervals. Blood samples were collected in the fasting state and half-hourly over a 2-h period post-ingestion of the fruits or glucose. The samples were analyzed for plasma glucose concentrations. Plasma glucose responses were assessed by the peak plasma glucose concentration, maximum increase in plasma glucose, 2-h postprandial plasma glucose level, and incremental area under the glucose curve and glycemic index (GI). The results showed that the blood glucose response to these three fruits was similar in terms of their incremental areas under the glucose curve, maximum increase in plasma glucose, and glycemic indices (GIs). The 2-h postprandial plasma glucose level of banana was significantly higher than that of pineapple, P < 0.025. The mean ± SEM GI values were as follows: pawpaw; 86 ± 26.8%; banana, 75.1 ± 21.8%; pineapple, 64.5 ± 11.3%. The GI of glucose is taken as 100. The GI of pineapple was significantly lower than that of glucose (P < 0.05). Banana, pawpaw, and pineapple produced a similar postprandial glucose response. Measured portions of these fruits may be used as fruit exchanges with pineapple having the most favorable glycemic response.

  1. Parsing glucose entry into the brain: novel findings obtained with enzyme-based glucose biosensors.

    PubMed

    Kiyatkin, Eugene A; Wakabayashi, Ken T

    2015-01-21

    Extracellular levels of glucose in brain tissue reflect dynamic balance between its gradient-dependent entry from arterial blood and its use for cellular metabolism. In this work, we present several sets of previously published and unpublished data obtained by using enzyme-based glucose biosensors coupled with constant-potential high-speed amperometry in freely moving rats. First, we consider basic methodological issues related to the reliability of electrochemical measurements of extracellular glucose levels in rats under physiologically relevant conditions. Second, we present data on glucose responses induced in the nucleus accumbens (NAc) by salient environmental stimuli and discuss the relationships between local neuronal activation and rapid glucose entry into brain tissue. Third, by presenting data on changes in NAc glucose induced by intravenous and intragastric glucose delivery, we discuss other mechanisms of glucose entry into the extracellular domain following changes in glucose blood concentrations. Lastly, by showing the pattern of NAc glucose fluctuations during glucose-drinking behavior, we discuss the relationships between "active" and "passive" glucose entry to the brain, its connection to behavior-related metabolic activation, and the possible functional significance of these changes in behavioral regulation. These data provide solid experimental support for the "neuronal" hypothesis of neurovascular coupling, which postulates the critical role of neuronal activity in rapid regulation of vascular tone, local blood flow, and entry of glucose and oxygen to brain tissue to maintain active cellular metabolism.

  2. Parsing Glucose Entry into the Brain: Novel Findings Obtained with Enzyme-Based Glucose Biosensors

    PubMed Central

    2015-01-01

    Extracellular levels of glucose in brain tissue reflect dynamic balance between its gradient-dependent entry from arterial blood and its use for cellular metabolism. In this work, we present several sets of previously published and unpublished data obtained by using enzyme-based glucose biosensors coupled with constant-potential high-speed amperometry in freely moving rats. First, we consider basic methodological issues related to the reliability of electrochemical measurements of extracellular glucose levels in rats under physiologically relevant conditions. Second, we present data on glucose responses induced in the nucleus accumbens (NAc) by salient environmental stimuli and discuss the relationships between local neuronal activation and rapid glucose entry into brain tissue. Third, by presenting data on changes in NAc glucose induced by intravenous and intragastric glucose delivery, we discuss other mechanisms of glucose entry into the extracellular domain following changes in glucose blood concentrations. Lastly, by showing the pattern of NAc glucose fluctuations during glucose-drinking behavior, we discuss the relationships between “active” and “passive” glucose entry to the brain, its connection to behavior-related metabolic activation, and the possible functional significance of these changes in behavioral regulation. These data provide solid experimental support for the “neuronal” hypothesis of neurovascular coupling, which postulates the critical role of neuronal activity in rapid regulation of vascular tone, local blood flow, and entry of glucose and oxygen to brain tissue to maintain active cellular metabolism. PMID:25490002

  3. Elucidation of the glucose transport pathway in glucose transporter 4 via steered molecular dynamics simulations.

    PubMed

    Sheena, Aswathy; Mohan, Suma S; Haridas, Nidhina Pachakkil A; Anilkumar, Gopalakrishnapillai

    2011-01-01

    GLUT4 is a predominant insulin regulated glucose transporter expressed in major glucose disposal tissues such as adipocytes and muscles. Under the unstimulated state, GLUT4 resides within intracellular vesicles. Various stimuli such as insulin translocate this protein to the plasma membrane for glucose transport. In the absence of a crystal structure for GLUT4, very little is known about the mechanism of glucose transport by this protein. Earlier we proposed a homology model for GLUT4 and performed a conventional molecular dynamics study revealing the conformational rearrangements during glucose and ATP binding. However, this study could not explain the transport of glucose through the permeation tunnel. To elucidate the molecular mechanism of glucose transport and its energetic, a steered molecular dynamics study (SMD) was used. Glucose was pulled from the extracellular end of GLUT4 to the cytoplasm along the pathway using constant velocity pulling method. We identified several key residues within the tunnel that interact directly with either the backbone ring or the hydroxyl groups of glucose. A rotation of glucose molecule was seen near the sugar binding site facilitating the sugar recognition process at the QLS binding site. This study proposes a possible glucose transport pathway and aids the identification of several residues that make direct interactions with glucose during glucose transport. Mutational studies are required to further validate the observation made in this study.

  4. Pancreatic regulation of glucose homeostasis

    PubMed Central

    Röder, Pia V; Wu, Bingbing; Liu, Yixian; Han, Weiping

    2016-01-01

    In order to ensure normal body function, the human body is dependent on a tight control of its blood glucose levels. This is accomplished by a highly sophisticated network of various hormones and neuropeptides released mainly from the brain, pancreas, liver, intestine as well as adipose and muscle tissue. Within this network, the pancreas represents a key player by secreting the blood sugar-lowering hormone insulin and its opponent glucagon. However, disturbances in the interplay of the hormones and peptides involved may lead to metabolic disorders such as type 2 diabetes mellitus (T2DM) whose prevalence, comorbidities and medical costs take on a dramatic scale. Therefore, it is of utmost importance to uncover and understand the mechanisms underlying the various interactions to improve existing anti-diabetic therapies and drugs on the one hand and to develop new therapeutic approaches on the other. This review summarizes the interplay of the pancreas with various other organs and tissues that maintain glucose homeostasis. Furthermore, anti-diabetic drugs and their impact on signaling pathways underlying the network will be discussed. PMID:26964835

  5. Why control blood glucose levels?

    PubMed

    Rossini, A A

    1976-03-01

    The controversy as to the relationship between the degree of control of diabetes and the progression of the complications of the disease has not been solved. However, in this review, various studies suggesting a relationship between the metabolic abnormality and the diabetic complications are examined. The disadvantages of the uncontrolled diabetes mellitus can be divided into two major categories-short-term and long-term. The short-term disadvantages of controlled diabetes mellitus include the following: (1) ketoacidosis and hyperosmolar coma; (2) intracellular dehydration; (3) electrolyte imbalance; (4) decreased phagocytosis; (5) immunologic and lymphocyte activity; (6) impairment of wound healing; and (7) abnormality of lipids. The long-term disadvantages of uncontrolled diabetes melitus include the following: (1) nephropathy; (2) neuropathy; (3) retinopathy; (4) cataract formation; (5) effect on perinatal mortality; (6) complications of vascular disease; and (7) the evaluation of various clinical studies suggesting the relationship of elevated blood glucose levels and complications of diabetes mellitus. It is suggested that until the question of control can absolutely be resolved, the recommendation is that the blood glucose levels should be controlled as close to the normal as possible.

  6. A self-powered glucose biosensing system.

    PubMed

    Slaughter, Gymama; Kulkarni, Tanmay

    2016-04-15

    A self-powered glucose biosensor (SPGS) system is fabricated and in vitro characterization of the power generation and charging frequency characteristics in glucose analyte are described. The bioelectrodes consist of compressed network of three-dimensional multi-walled carbon nanotubes with redox enzymes, pyroquinoline quinone glucose dehydrogenase (PQQ-GDH) and laccase functioning as the anodic and cathodic catalyst, respectively. When operated in 45 mM glucose, the biofuel cell exhibited an open circuit voltage and power density of 681.8 mV and 67.86 µW/cm(2) at 335 mV, respectively, with a current density of 202.2 µA/cm(2). Moreover, at physiological glucose concentration (5mM), the biofuel cell exhibits open circuit voltage and power density of 302.1 mV and 15.98 µW/cm(2) at 166.3 mV, respectively, with a current density of 100 µA/cm(2). The biofuel cell assembly produced a linear dynamic range of 0.5-45 mM glucose. These findings show that glucose biofuel cells can be further investigated in the development of a self-powered glucose biosensor by using a capacitor as the transducer element. By monitoring the capacitor charging frequencies, which are influenced by the concentration of the glucose analyte, a linear dynamic range of 0.5-35 mM glucose is observed. The operational stability of SPGS is monitored over a period of 63 days and is found to be stable with 15.38% and 11.76% drop in power density under continuous discharge in 10mM and 20mM glucose, respectively. These results demonstrate that SPGSs can simultaneously generate bioelectricity to power ultra-low powered devices and sense glucose. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Fabrication of nanoindented electrodes for glucose detection.

    PubMed

    Slaughter, Gymama

    2010-03-01

    The objective of this article was to design, fabricate, and evaluate a novel type of glucose biosensors based on the use of atomic force microscopy to create nanoindented electrodes (NIDEs) for the selective detection of glucose. Atomic force microscopy nanoindentation techniques were extended to covalently immobilized glucose oxidase on NIDEs via composite hydrogel membranes composed of interpenetrating networks of inherently conductive poly(3,4-ethylenedioxythiophene) tetramethacrylate grown within ultraviolet cross-linked hydroxyethylmethacrylate-based hydrogels to produce an in vitro amperometric NIDE biosensor for the long-term monitoring of glucose. The calibration curve for glucose was linear from 0.25 to 20 mM. Results showed that the NIDE glucose biosensor has a much higher detection sensitivity of 0.32 microA/mM and rapid response times (<5 seconds). There was no interference from the competing interferent (fructose) present; the only interference was from species that react with H(2)O(2) (ascorbic acid). The linear equation was B(response) (microA) = 0.323 [glucose] (mM) + 0.634 (microA); n = 24, r(2) = 0.994. Results showed that the resultant NIDE glucose biosensor increases the dynamic range, device sensitivity, and response time and has excellent detecting performance for glucose. (c) 2010 Diabetes Technology Society.

  8. Enzyme Analysis to Determine Glucose Content

    NASA Astrophysics Data System (ADS)

    Carpenter, Charles; Ward, Robert E.

    Enzyme analysis is used for many purposes in food science and technology. Enzyme activity is used to indicate adequate processing, to assess enzyme preparations, and to measure constituents of foods that are enzyme substrates. In this experiment, the glucose content of corn syrup solids is determined using the enzymes, glucose oxidase and peroxidase. Glucose oxidase catalyzes the oxidation of glucose to form hydrogen peroxide (H2O2), which then reacts with a dye in the presence of peroxidase to give a stable colored product.

  9. Glucose Transporters in Cardiac Metabolism and Hypertrophy

    PubMed Central

    Shao, Dan; Tian, Rong

    2016-01-01

    The heart is adapted to utilize all classes of substrates to meet the high-energy demand, and it tightly regulates its substrate utilization in response to environmental changes. Although fatty acids are known as the predominant fuel for the adult heart at resting stage, the heart switches its substrate preference toward glucose during stress conditions such as ischemia and pathological hypertrophy. Notably, increasing evidence suggests that the loss of metabolic flexibility associated with increased reliance on glucose utilization contribute to the development of cardiac dysfunction. The changes in glucose metabolism in hypertrophied hearts include altered glucose transport and increased glycolysis. Despite the role of glucose as an energy source, changes in other nonenergy producing pathways related to glucose metabolism, such as hexosamine biosynthetic pathway and pentose phosphate pathway, are also observed in the diseased hearts. This article summarizes the current knowledge regarding the regulation of glucose transporter expression and translocation in the heart during physiological and pathological conditions. It also discusses the signaling mechanisms governing glucose uptake in cardiomyocytes, as well as the changes of cardiac glucose metabolism under disease conditions. PMID:26756635

  10. Calculating High Speed Centrifugal Compressor Performance from Averaged Measurements

    NASA Astrophysics Data System (ADS)

    Lou, Fangyuan; Fleming, Ryan; Key, Nicole L.

    2012-12-01

    To improve the understanding of high performance centrifugal compressors found in modern aircraft engines, the aerodynamics through these machines must be experimentally studied. To accurately capture the complex flow phenomena through these devices, research facilities that can accurately simulate these flows are necessary. One such facility has been recently developed, and it is used in this paper to explore the effects of averaging total pressure and total temperature measurements to calculate compressor performance. Different averaging techniques (including area averaging, mass averaging, and work averaging) have been applied to the data. Results show that there is a negligible difference in both the calculated total pressure ratio and efficiency for the different techniques employed. However, the uncertainty in the performance parameters calculated with the different averaging techniques is significantly different, with area averaging providing the least uncertainty.

  11. Rapid quantitative detection of glucose content in glucose injection by reaction headspace gas chromatography.

    PubMed

    Xie, Wei-Qi; Gong, Yi-Xian; Yu, Kong-Xian

    2017-10-20

    This work investigates an automated technique for rapid detecting the glucose content in glucose injection by reaction headspace gas chromatography (HS-GC). This method is based on the oxidation reaction of glucose in glucose injection with potassium dichromate. The carbon dioxide (CO 2 ) formed from the oxidation reaction can be quantitatively detected by GC. The results show that the relative standard deviation (RSD) of the present method was within 2.91%, and the measured glucose contents in glucose injection closely match those quantified by the reference method (relative differences <6.45%). The new HS-GC technique is rapid, practical and can be used to the batch detection of the glucose content in glucose injection related applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Effect of a Prolonged Altitude Expedition on Glucose Tolerance and Abdominal Fatness

    ERIC Educational Resources Information Center

    Chen, Mu-Tsung; Lee, Wen-Chih; Chen, Shih-Chang; Chen, Chiu-Chou; Chen, Chung-Yu; Lee, Shin-Da; Jensen, Jorgen; Kuo, Chia-Hua

    2010-01-01

    In the present study, we investigated the effect of a long-term mountain expedition on glucose tolerance and insulin action. Twelve registered mountaineers ages 31 years (SD = 1.1) participated in a 25-day expedition at a 2,200-3,800-m altitude with an average duration of 8 hr per day. Arterial oxygen saturation (SaO[subscript 2]) was…

  13. The effectiveness of glucose, sucrose, and fructose in treating hypoglycemia in children with type 1 diabetes.

    PubMed

    Husband, Allison C; Crawford, Susan; McCoy, Lesley A; Pacaud, Danièle

    2010-05-01

    There is a lack of evidence regarding the most effective treatment option for managing naturally occurring hypoglycemia in children with type 1 diabetes. The objectives of this study were (i) to determine if sucrose and fructose are equally effective as glucose in the treatment of spontaneous hypoglycemia in children with type 1 diabetes; and (ii) to determine prestudy and poststudy hypoglycemia treatment preferences. Thirty-three subjects [aged 5.4-15.5 yr and average duration of type 1 diabetes of 3.1 yr (SD = 2.3)] participated in a randomized, crossover design. The main outcome was the effectiveness of treatment as defined by a blood glucose meter reading that was > or = 4.0 mmol/L 15 min after treatment. Each subject treated five hypoglycemic events with each treatment type: glucose (BD Glucose Tablets), sucrose (Skittles), and fructose (Fruit to Go). There was a significant difference between the effectiveness of the three treatments [Wilk's Lambda F(2,28) = 8.64, p = 0.001]. No significant difference between treatment with glucose and treatment with sucrose was noted, but the treatment effectiveness for fructose was significantly lower than sucrose [F (1,29) = 16.09, p < 0.001] and glucose [F (1,29) = 15.64, p < 0.001]. The preferred treatment choices before the study were as follows: 36% glucose, 18% sucrose, and 33% fructose sources. Poststudy, 52% of children preferred the same treatment, which was effective (glucose or sucrose), followed by 35% who changed their preference to an effective treatment. Skittles are as effective in treating hypoglycemia as more expensive BD Glucose Tablets in children with type 1 diabetes.

  14. Fluorescence intensity- and lifetime-based glucose sensing using glucose/galactose-binding protein.

    PubMed

    Pickup, John C; Khan, Faaizah; Zhi, Zheng-Liang; Coulter, Jonathan; Birch, David J S

    2013-01-01

    We review progress in our laboratories toward developing in vivo glucose sensors for diabetes that are based on fluorescence labeling of glucose/galactose-binding protein. Measurement strategies have included both monitoring glucose-induced changes in fluorescence resonance energy transfer and labeling with the environmentally sensitive fluorophore, badan. Measuring fluorescence lifetime rather than intensity has particular potential advantages for in vivo sensing. A prototype fiber-optic-based glucose sensor using this technology is being tested. © 2013 Diabetes Technology Society.

  15. CMOS image sensor-based implantable glucose sensor using glucose-responsive fluorescent hydrogel

    PubMed Central

    Tokuda, Takashi; Takahashi, Masayuki; Uejima, Kazuhiro; Masuda, Keita; Kawamura, Toshikazu; Ohta, Yasumi; Motoyama, Mayumi; Noda, Toshihiko; Sasagawa, Kiyotaka; Okitsu, Teru; Takeuchi, Shoji; Ohta, Jun

    2014-01-01

    A CMOS image sensor-based implantable glucose sensor based on an optical-sensing scheme is proposed and experimentally verified. A glucose-responsive fluorescent hydrogel is used as the mediator in the measurement scheme. The wired implantable glucose sensor was realized by integrating a CMOS image sensor, hydrogel, UV light emitting diodes, and an optical filter on a flexible polyimide substrate. Feasibility of the glucose sensor was verified by both in vitro and in vivo experiments. PMID:25426316

  16. CMOS image sensor-based implantable glucose sensor using glucose-responsive fluorescent hydrogel.

    PubMed

    Tokuda, Takashi; Takahashi, Masayuki; Uejima, Kazuhiro; Masuda, Keita; Kawamura, Toshikazu; Ohta, Yasumi; Motoyama, Mayumi; Noda, Toshihiko; Sasagawa, Kiyotaka; Okitsu, Teru; Takeuchi, Shoji; Ohta, Jun

    2014-11-01

    A CMOS image sensor-based implantable glucose sensor based on an optical-sensing scheme is proposed and experimentally verified. A glucose-responsive fluorescent hydrogel is used as the mediator in the measurement scheme. The wired implantable glucose sensor was realized by integrating a CMOS image sensor, hydrogel, UV light emitting diodes, and an optical filter on a flexible polyimide substrate. Feasibility of the glucose sensor was verified by both in vitro and in vivo experiments.

  17. Glucose metabolism disorder in obese children assessed by continuous glucose monitoring system.

    PubMed

    Zou, Chao-Chun; Liang, Li; Hong, Fang; Zhao, Zheng-Yan

    2008-02-01

    Continuous glucose monitoring system (CGMS) can measure glucose levels at 5-minute intervals over a few days, and may be used to detect hypoglycemia, guide insulin therapy, and control glucose levels. This study was undertaken to assess the glucose metabolism disorder by CGMS in obese children. Eighty-four obese children were studied. Interstitial fluid (ISF) glucose levels were measured by CGMS for 24 hours covering the time for oral glucose tolerance test (OGTT). Impaired glucose tolerance (IGT), impaired fasting glucose (IFG), type 2 diabetic mellitus (T2DM) and hypoglycemia were assessed by CGMS. Five children failed to complete CGMS test. The glucose levels in ISF measured by CGMS were highly correlated with those in capillary samples (r=0.775, P<0.001). However, the correlation between ISF and capillary glucose levels was lower during the first hour than that in the later time period (r=0.722 vs r=0.830), and the ISF glucose levels in 69.62% of children were higher than baseline levels in the initial 1-3 hours. In 79 obese children who finished the CGMS, 2 children had IFG, 2 had IGT, 3 had IFG + IGT, and 2 had T2DM. Nocturnal hypoglycemia was noted during the overnight fasting in 11 children (13.92%). Our data suggest that glucose metabolism disorder including hyperglycemia and hypoglycemia is very common in obese children. Further studies are required to improve the precision of the CGMS in children.

  18. Effects of Insulin on Brain Glucose Metabolism in Impaired Glucose Tolerance

    PubMed Central

    Hirvonen, Jussi; Virtanen, Kirsi A.; Nummenmaa, Lauri; Hannukainen, Jarna C.; Honka, Miikka-Juhani; Bucci, Marco; Nesterov, Sergey V.; Parkkola, Riitta; Rinne, Juha; Iozzo, Patricia; Nuutila, Pirjo

    2011-01-01

    OBJECTIVE Insulin stimulates brain glucose metabolism, but this effect of insulin is already maximal at fasting concentrations in healthy subjects. It is not known whether insulin is able to stimulate glucose metabolism above fasting concentrations in patients with impaired glucose tolerance. RESEARCH DESIGN AND METHODS We studied the effects of insulin on brain glucose metabolism and cerebral blood flow in 13 patients with impaired glucose tolerance and nine healthy subjects using positron emission tomography (PET). All subjects underwent PET with both [18F]fluorodeoxyglucose (for brain glucose metabolism) and [15O]H2O (for cerebral blood flow) in two separate conditions (in the fasting state and during a euglycemic-hyperinsulinemic clamp). Arterial blood samples were acquired during the PET scans to allow fully quantitative modeling. RESULTS The hyperinsulinemic clamp increased brain glucose metabolism only in patients with impaired glucose tolerance (whole brain: +18%, P = 0.001) but not in healthy subjects (whole brain: +3.9%, P = 0.373). The hyperinsulinemic clamp did not alter cerebral blood flow in either group. CONCLUSIONS We found that insulin stimulates brain glucose metabolism at physiological postprandial levels in patients with impaired glucose tolerance but not in healthy subjects. These results suggest that insulin stimulation of brain glucose metabolism is maximal at fasting concentrations in healthy subjects but not in patients with impaired glucose tolerance. PMID:21270256

  19. Nonfermentable, glucose-containing products formed from glucose under cellulose acid hydrolysis conditions

    Treesearch

    J. L. Minor

    1983-01-01

    Solutions of D-glucose in dilute sulfuric acid were allowed to react under time and temperature conditions which simulated the production of glucose from cellulose. Under these conditions, glucose undergoes a number of reactions including isomerization, dehydration, transglycosidation, polymerization, and anhydride formation. The specific interest in this report was to...

  20. Pseudo-bi-enzyme glucose sensor: ZnS hollow spheres and glucose oxidase concerted catalysis glucose.

    PubMed

    Shuai, Ying; Liu, Changhua; Wang, Jia; Cui, Xiaoyan; Nie, Ling

    2013-06-07

    This work creatively uses peroxidase-like ZnS hollow spheres (ZnS HSs) to cooperate with glucose oxidase (GOx) for glucose determinations. This approach is that the ZnS HSs electrocatalytically oxidate the enzymatically generated H2O2 to O2, and then the O2 circularly participates in the previous glucose oxidation by glucose oxidase. Au nanoparticles (AuNPs) and carbon nanotubes (CNTs) are used as electron transfer and enzyme immobilization matrices, respectively. The biosensor of glucose oxidase-carbon nanotubes-Au nanoparticles-ZnS hollow spheres-gold electrode (GOx-CNT-AuNPs-ZnS HSs-GE) exhibits a rapid response, a low detection limit (10 μM), a wide linear range (20 μM to 7 mM) as well as good anti-interference, long-term longevity and reproducibility.

  1. Improved Oxygen-Beam Texturing of Glucose-Monitoring Optics

    NASA Technical Reports Server (NTRS)

    Banks, Bruce A.

    2006-01-01

    An improved method has been devised for using directed, hyperthermal beams of oxygen atoms and ions to impart desired textures to the tips of polymethylmethacrylate [PMMA] optical fibers to be used in monitoring the glucose content of blood. The improved method incorporates, but goes beyond, the method described in Texturing Blood-Glucose- Monitoring Optics Using Oxygen Beams (LEW-17642-1), NASA Tech Briefs, Vol. 29, No. 4 (April 2005), page 11a. The basic principle of operation of such a glucose-monitoring sensor is as follows: The textured surface of the optical fiber is coated with chemicals that interact with glucose in such a manner as to change the reflectance of the surface. Light is sent down the optical fiber and is reflected from, the textured surface. The resulting change in reflectance of the light is measured as an indication of the concentration of glucose. The required texture on the ends of the optical fibers is a landscape of microscopic cones or pillars having high aspect ratios (microscopic structures being taller than they are wide). The average distance between hills must be no more than about 5 mso that blood cells (which are wider) cannot enter the valleys between the hills, where they would interfere with optical sensing of glucose in the blood plasma. On the other hand, the plasma is required to enter the valleys, and high aspect ratio structures are needed to maximize the surface area in contact with the plasma, thereby making it possible to obtain a given level of optical glucose-measurement sensitivity with a relatively small volume of blood. There is an additional requirement that the hills be wide enough that a sufficient amount of light can propagate into them and, after reflection, can propagate out of them. The method described in the cited prior article produces a texture comprising cones and pillars that conform to the average-distance and aspect-ratio requirements. However, a significant fraction of the cones and pillars are so

  2. Atypical antipsychotics and glucose homeostasis.

    PubMed

    Bergman, Richard N; Ader, Marilyn

    2005-04-01

    Persistent reports have linked atypical antipsychotics with diabetes, yet causative mechanisms responsible for this linkage are unclear. Goals of this review are to outline the pathogenesis of nonimmune diabetes and to survey the available literature related to why antipsychotics may lead to this disease. We accessed the literature regarding atypical antipsychotics and glucose homeostasis using PubMed. The search included English-language publications from 1990 through October 2004. Keywords used included atypical antipsychotics plus one of the following: glucose, insulin, glucose tolerance, obesity, or diabetes. In addition, we culled information from published abstracts from several national and international scientific meetings for the years 2001 through 2004, including the American Diabetes Association, the International Congress on Schizophrenia Research, and the American College of Neuropsychopharmacology. The latter search was necessary because of the paucity of well-controlled prospective studies. We examined publications with significant new data or publications that contributed to the overall comprehension of the impact of atypical antipsychotics on glucose metabolism. We favored original peer-reviewed articles and were less likely to cite single case studies and/or anecdotal information. Approximately 75% of the fewer than 150 identified articles were examined and included in this review. Validity of data was evaluated using the existence of peer-review status as well as our own experience with methodology described in the specific articles. The metabolic profile caused by atypical antipsychotic treatment resembles type 2 diabetes. These agents cause weight gain in treated subjects and may induce obesity in both visceral and subcutaneous depots, as occurs in diabetes. Insulin resistance, usually associated with obesity, occurs to varying degrees with different antipsychotics, although more comparative studies with direct assessment of resistance are

  3. Glucose-6-Phosphate Dehydrogenase Deficiency.

    PubMed

    Luzzatto, Lucio; Nannelli, Caterina; Notaro, Rosario

    2016-04-01

    G6PD is a housekeeping gene expressed in all cells. Glucose-6-phosphate dehydrogenase (G6PD) is part of the pentose phosphate pathway, and its main physiologic role is to provide NADPH. G6PD deficiency, one of the commonest inherited enzyme abnormalities in humans, arises through one of many possible mutations, most of which reduce the stability of the enzyme and its level as red cells age. G6PD-deficient persons are mostly asymptomatic, but they can develop severe jaundice during the neonatal period and acute hemolytic anemia when they ingest fava beans or when they are exposed to certain infections or drugs. G6PD deficiency is a global health issue. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Thermoinactivation Mechanism of Glucose Isomerase

    NASA Astrophysics Data System (ADS)

    Lim, Leng Hong; Saville, Bradley A.

    In this article, the mechanisms of thermoinactivation of glucose isomerase (GI) from Streptomyces rubiginosus (in soluble and immobilized forms) were investigated, particularly the contributions of thiol oxidation of the enzyme's cysteine residue and a "Maillard-like" reaction between the enzyme and sugars in high fructose corn syrup (HFCS). Soluble GI (SGI) was successfully immobilized on silica gel (13.5 μm particle size), with an activity yield between 20 and 40%. The immobilized GI (IGI) has high enzyme retention on the support during the glucose isomerization process. In batch reactors, SGI (half-life =145 h) was more stable than IGI (half-life=27 h) at 60°C in HFCS, whereas at 80°C, IGI (half-life=12 h) was more stable than SGI (half-life=5.2 h). IGI was subject to thiol oxidation at 60°C, which contributed to the enzyme's deactivation. IGI was subject to thiol oxidation at 80°C, but this did not contribute to the deactivation of the enzyme. SGI did not undergo thiol oxidation at 60°C, but at 80°C SGI underwent severe precipitation and thiol oxidation, which caused the enzyme to deactivate. Experimental results show that immobilization suppresses the destablizing effect of thiol oxidation on GI. A "Maillard-like" reaction between SGI and the sugars also caused SGI thermoinactivation at 60, 70, and 80°C, but had minimal effect on IGI. At 60 and 80°C, IGI had higher thermostability in continuous reactors than in batch reactors, possibily because of reduced contact with deleterious compounds in HFCS.

  5. Carbon nanotube mat as mediator-less glucose sensor electrode.

    PubMed

    Ryu, Jongeun; Kim, Hansang; Lee, Sangeui; Hahn, H Thomas; Lashmore, David

    2010-02-01

    In this paper, the direct electron transfer of glucose oxidase (GOx) on carbon nanotube (CNT) mat electrode is demonstrated. Because of the electrical conductivity and mechanical strength of CNT mat, it can be used as an electrode as well as a catalyst support. Therefore, the preparation process for the CNT mat based sensor electrode is simpler than that of the conventional CNT dispersed sensor electrodes. GOx was covalently immobilized on the oxidized CNT mat, which is connected to a wire by using silver paste and epoxy glue. Attenuated Total Reflectance Fourier Transform-Infrared (ATR-FTIR) result shows transmittance peaks at 1637 cm(-1) and 1525 cm(-1) which are corresponding to the band I and II of amide. Cyclic voltammetric shows a pair of well-defined redox peaks with the average formal potential of -0.425 V (vs. Ag/AgCl reference electrode) in the phosphate buffered saline solution (1 x PBS, pH 7.4). Calculated electron transfer rate constant and the surface density of GOx were 1.71 s(-1) and (3.27 +/- 0.20) x 10(-13) mol/cm2, respectively. Cyclic voltammograms of GOx-CNT mat in glucose solution show that the immobilized GOx retains its catalytic activity to glucose. The amperometric sensor response showed a linear dependence on the glucose concentration in the range of 0.2 mM to 2.18 mM with a detection sensitivity of 4.05 microA mM(-1) cm(-2). The Michaelis-Menten constant of the immobilized GOx was calculated to be 2.18 mM.

  6. Beyond the morphology of the glucose curve following an oral glucose tolerance test in obese youth.

    PubMed

    Nolfe, Giuseppe; Spreghini, Maria Rita; Sforza, Rita Wietrzycowska; Morino, Giuseppe; Manco, Melania

    2012-01-01

    To describe the morphology of glucose curve during the oral glucose tolerance test (OGTT) and any association with glucose tolerance, insulin action and secretion in obese youth. Cross-sectional. OGTT data of 553 patients were analysed. Subjects were divided in groups based on the morphology (i.e. monophasic, biphasic, triphasic and upward monotonous) of glucose curve. Insulin action was estimated by the homeostasis model assessment of insulin resistance, the insulin sensitivity, the muscle insulin sensitivity and the hepatic insulin resistance indexes (HIRI), and the oral glucose insulin sensitivity (OGIS). Insulin secretion was estimated by the insulinogenic index (IGI). Disposition index, including the insulin secretion-sensitivity index-2, and areas under glucose (AUC(G)) and insulin (AUC(I)) curves were computed. In patients with normal glucose tolerance (n=522), prevalent morphology of the glucose curve was monophasic (n=285, 54%). Monophasic morphology was associated with the highest concentration of 1 h plasma glucose (P<0.0001) and AUC(G) (P<0.0001); biphasic morphology with better insulin sensitivity as estimated by OGIS (P<0.03) and lower AUC(I) (P<0.0001); triphasic morphology with the highest values of HIRI (P<0.02) and IGI (P<0.007). By combining morphologies of glucose and insulin curves or time of the glucose peak, a deeper characterisation of different phenotypes of glucose metabolism emerged. Morphologies of the glucose curve seem reflecting different metabolic phenotypes of insulin action and secretion, particularly when combined with morphologies of insulin curve or time of glucose peak. Such findings may deserve validation in cohort study, in which glucose metabolism would be estimated by using gold standard techniques.

  7. Au-nanocluster emission based glucose sensing.

    PubMed

    Hussain, A M P; Sarangi, S N; Kesarwani, J A; Sahu, S N

    2011-11-15

    Fabrication of a glucose biosensor based on Au-cluster emission quenching in the UV region is reported. The glucose biosensor is highly sensitive to β-d-glucose in 2.5-25.0mM range as confirmed from a linear calibration plot between Au-cluster colloid emission intensity as a function of β-d-glucose concentration. The interaction of β-d-glucose with l-cysteine capped Au cluster colloids has been confirmed from their Fourier transformed infrared spectroscopy (FTIR) measurements. It has been found that the biomolecules present in the serum such as ascorbic and uric acids, proteins and peptides do not interfere and affect in glucose estimation as confirmed from their absorption and fluorescence (FL) emission measurements. Practical utility of this sensor based on FL quenching method has been demonstrated by estimating the glucose level in human serum that includes diabetes and the data were found to be comparable or more accurate than those of the pathological data obtained from a local hospital. In addition, this biosensor is useful to detect glucose level over a wide range with sensor response time of the order of nano to picoseconds that is emission lifetime of Au clusters. Copyright © 2011 Elsevier B.V. All rights reserved.

  8. Toward CMOS image sensor based glucose monitoring.

    PubMed

    Devadhasan, Jasmine Pramila; Kim, Sanghyo

    2012-09-07

    Complementary metal oxide semiconductor (CMOS) image sensor is a powerful tool for biosensing applications. In this present study, CMOS image sensor has been exploited for detecting glucose levels by simple photon count variation with high sensitivity. Various concentrations of glucose (100 mg dL(-1) to 1000 mg dL(-1)) were added onto a simple poly-dimethylsiloxane (PDMS) chip and the oxidation of glucose was catalyzed with the aid of an enzymatic reaction. Oxidized glucose produces a brown color with the help of chromogen during enzymatic reaction and the color density varies with the glucose concentration. Photons pass through the PDMS chip with varying color density and hit the sensor surface. Photon count was recognized by CMOS image sensor depending on the color density with respect to the glucose concentration and it was converted into digital form. By correlating the obtained digital results with glucose concentration it is possible to measure a wide range of blood glucose levels with great linearity based on CMOS image sensor and therefore this technique will promote a convenient point-of-care diagnosis.

  9. Molecular Pathophysiology of Hepatic Glucose Production

    PubMed Central

    Sharabi, Kfir; Tavares, Clint D. J.; Rines, Amy K.; Puigserver, Pere

    2015-01-01

    Maintaining blood glucose concentration within a relatively narrow range through periods of fasting or excess nutrient availability is essential to the survival of the organism. This is achieved through an intricate balance between glucose uptake and endogenous glucose production to maintain constant glucose concentrations. The liver plays a major role in maintaining normal whole body glucose levels by regulating the processes of de novo glucose production (gluconeogenesis) and glycogen breakdown (glycogenolysis), thus controlling the levels of hepatic glucose release. Aberrant regulation of hepatic glucose production (HGP) can result in deleterious clinical outcomes, and excessive HGP is a major contributor to the hyperglycemia observed in Type 2 diabetes mellitus (T2DM). Indeed, adjusting glycaemia as close as possible to a non-diabetic range is the foremost objective in the medical treatment of patients with T2DM and is currently achieved in the clinic primarily through suppression of HGP. Here, we review the molecular mechanisms controlling HGP in response to nutritional and hormonal signals and discuss how these signals are altered in T2DM. PMID:26549348

  10. Glucose Disappearance in Biological Treatment Systems

    PubMed Central

    Jeris, John S.; Cardenas, Raul R.

    1966-01-01

    Laboratory scale anaerobic and aerobic treatment units were conditioned with a daily slug-feed of glucose. After a period of acclimation and stabilization, glucose disappearance was monitored continuously after the slug feed. A continuous sampling apparatus is described. Mathematical analysis of the data indicate zero-order reactions for both biological treatment systems. PMID:16349685

  11. Glucose-Induced Acidification in Yeast Cultures

    ERIC Educational Resources Information Center

    Myers, Alan; Bourn, Julia; Pool, Brynne

    2005-01-01

    We present an investigation (for A-level biology students and equivalent) into the mechanism of glucose-induced extracellular acidification in unbuffered yeast suspensions. The investigation is designed to enhance understanding of aspects of the A-level curriculum that relate to the phenomenon (notably glucose catabolism) and to develop key skills…

  12. Canagliflozin Lowers Postprandial Glucose and Insulin by Delaying Intestinal Glucose Absorption in Addition to Increasing Urinary Glucose Excretion

    PubMed Central

    Polidori, David; Sha, Sue; Mudaliar, Sunder; Ciaraldi, Theodore P.; Ghosh, Atalanta; Vaccaro, Nicole; Farrell, Kristin; Rothenberg, Paul; Henry, Robert R.

    2013-01-01

    OBJECTIVE Canagliflozin, a sodium glucose cotransporter (SGLT) 2 inhibitor, is also a low-potency SGLT1 inhibitor. This study tested the hypothesis that intestinal canagliflozin levels postdose are sufficiently high to transiently inhibit intestinal SGLT1, thereby delaying intestinal glucose absorption. RESEARCH DESIGN AND METHODS This two-period, crossover study evaluated effects of canagliflozin on intestinal glucose absorption in 20 healthy subjects using a dual-tracer method. Placebo or canagliflozin 300 mg was given 20 min before a 600-kcal mixed-meal tolerance test. Plasma glucose, 3H-glucose, 14C-glucose, and insulin were measured frequently for 6 h to calculate rates of appearance of oral glucose (RaO) in plasma, endogenous glucose production, and glucose disposal. RESULTS Compared with placebo, canagliflozin treatment reduced postprandial plasma glucose and insulin excursions (incremental 0- to 2-h area under the curve [AUC0–2h] reductions of 35% and 43%, respectively; P < 0.001 for both), increased 0- to 6-h urinary glucose excretion (UGE0–6h, 18.2 ± 5.6 vs. <0.2 g; P < 0.001), and delayed RaO. Canagliflozin reduced AUC RaO by 31% over 0 to 1 h (geometric means, 264 vs. 381 mg/kg; P < 0.001) and by 20% over 0 to 2 h (576 vs. 723 mg/kg; P = 0.002). Over 2 to 6 h, canagliflozin increased RaO such that total AUC RaO over 0 to 6 h was <6% lower versus placebo (960 vs. 1,018 mg/kg; P = 0.003). A modest (∼10%) reduction in acetaminophen absorption was observed over the first 2 h, but this difference was not sufficient to explain the reduction in RaO. Total glucose disposal over 0 to 6 h was similar across groups. CONCLUSIONS Canagliflozin reduces postprandial plasma glucose and insulin by increasing UGE (via renal SGLT2 inhibition) and delaying RaO, likely due to intestinal SGLT1 inhibition. PMID:23412078

  13. Glucose Biosensor Based on Immobilization of Glucose Oxidase in Platinum Nanoparticles/Graphene/Chitosan Nanocomposite Film

    SciTech Connect

    Wu, Hong; Wang, Jun; Kang, Xinhuang

    2009-09-01

    The bionanocomposite film consisting of glucose oxidase/Pt/functional graphene sheets/chitosan (GOD/Pt/FGS/chitosan) for glucose sensing was described. With the electrocatalytic synergy of FGS and Pt nanoparticles to hydrogen peroxide, a sensitive biosensor with detection limit of 0.6 µM glucose was achieved. The biosensor also had good reproducibility, long term stability and negligible interfering signals from ascorbic acid and uric acid comparing to the response to glucose. The large surface area and good conductivity of graphene suggests that graphene is a potential candidate for sensor material. The hybrid nanocomposite glucose sensor provides new opportunity for clinical diagnosis and point-of-care applications.

  14. Free energy landscape for glucose condensation reactions.

    PubMed

    Liu, Dajiang; Nimlos, Mark R; Johnson, David K; Himmel, Michael E; Qian, Xianghong

    2010-12-16

    Ab initio molecular dynamics and metadynamics simulations were used to determine the free energy surfaces (FES) for the acid catalyzed β-D-glucose condensation reaction. Protonation of C1-OH on the β-D-glucose, breakage of the C1-O1 bond, and the formation of C1 carbocation is the rate-limiting step. The effects of solvent on the reaction were investigated by determining the FES both in the absence and presence of solvent water. It was found that water played a critical role in these reactions. The reaction barrier for the proton-catalyzed glucose condensation reaction is solvent induced because of proton's high affinity for water. During these simulations, β-D-glucose conversion to α-d-glucose process via the C1 carbocation was also observed. The associated free energy change and activation barrier for this reaction were determined.

  15. The Association Between Glucose Exposure and the Risk of Peritonitis in Peritoneal Dialysis Patients.

    PubMed

    van Diepen, Anouk T N; van Esch, Sadie; Struijk, Dirk G; Krediet, Raymond T

    ♦ Little or no clinical evidence is available on the association between glucose exposure and peritoneal host defense in peritoneal dialysis (PD) patients. The objective of the present study was to quantify the exposure to glucose during the first year on PD and investigate the association with subsequent peritonitis. ♦ We analyzed prospectively collected demographic and peritonitis data from incident adult PD patients between 1990 and 2010. For the present study, we conducted a review of both in- and outpatient medical records of all patients to obtain their day-to-day dialysis schemes during the first year on PD. From these data, the average exposure to glucose was quantified. The exposure was stratified into low- and high-glucose groups based on the median, analyzed per standard deviation and in quartiles. Cox proportional hazard models were used to calculate crude and adjusted hazard ratios (HRs) and 95% confidence intervals for the association between glucose exposure and peritonitis. Adjustments were made for age, sex, primary kidney disease, diabetes mellitus, Davies comorbidity score and the treatment period. ♦ In total, 230 patients were included in the study of whom 151 (66%) experienced a first peritonitis episode. The median follow-up time was 2.6 years (interquartile range [IQR]: 1.9 - 3.8) in the low-glucose group and 3.1 (IQR: 2.1 - 4.2) in the high-glucose group. After adjustment for confounding factors, no association between high glucose exposure and the risk of peritonitis was found (HR: 0.81; 0.55 - 1.17). No association was present when glucose exposure was analyzed per standard deviation (SD) (HR: 0.98; 0.79 - 1.21) or patient quartiles were applied. No association was identified between glucose exposure and severe peritonitis, Staphylococcus aureus peritonitis, or a peritonitis episode that lasted more than 14 days. ♦ Exposure to glucose is not associated with an increased risk of peritonitis. The equilibrium between glycemic harm to

  16. Glucose absorption in acute peritoneal dialysis.

    PubMed

    Podel, J; Hodelin-Wetzel, R; Saha, D C; Burns, G

    2000-04-01

    During acute peritoneal dialysis (APD), it is known that glucose found in the dialysate solution contributes to the provision of significant calories. It has been well documented in continuous ambulatory peritoneal dialysis (CAPD) that glucose absorption occurs. In APD, however, it remains unclear how much glucose absorption actually does occur. Therefore, the purpose of this study was to determine whether it is appropriate to use the formula used to calculate glucose absorption in CAPD (Grodstein et al) among patients undergoing APD. Actual measurements of glucose absorption (Method I) were calculated in 9 patients undergoing APD treatment for >24 hours who were admitted to the intensive care unit. Glucose absorption using the Grodstein et al formula (Method II) was also determined and compared with the results of actual measurements. The data was then further analyzed based on the factors that influence glucose absorption, specifically dwell time and concentration. The mean total amount of glucose absorbed was 43% +/- 15%. However, when dwell time and concentration were further examined, significant differences were noted. Method I showed a cumulative increase over time. Method II showed that absorption was fixed. This suggests that with the variation in dwell time commonly seen in the acute care setting, the use of Method II may not be accurate. In each of the 2 methods, a significant difference in glucose absorption was noted when comparing the use of 1.5% and 4.25% dialysate concentrations. The established formula designed for CAPD should not be used for calculating glucose absorption in patients receiving APD because variation in dwell time and concentration should be taken into account. Because of the time constraints and staffing required to calculate each exchange individually, combined with the results of the study, we recommend the use of the percentage estimate of 40% to 50%.

  17. Jump neural network for real-time prediction of glucose concentration.

    PubMed

    Zecchin, Chiara; Facchinetti, Andrea; Sparacino, Giovanni; Cobelli, Claudio

    2015-01-01

    Prediction of the future value of a variable is of central importance in a wide variety of fields, including economy and finance, meteorology, informatics, and, last but not least important, medicine. For example, in the therapy of Type 1 Diabetes (T1D), in which, for patient safety, glucose concentration in the blood should be maintained in a defined normoglycemic range, the ability to forecast glucose concentration in the short-term (with a prediction horizon of around 30 min) might be sufficient to reduce the incidence of hypoglycemic and hyperglycemic events. Neural Network (NN) approaches are suitable for prediction purposes because of their ability to model nonlinear dynamics and handle in their inputs signals coming from different domains. In this chapter we illustrate the design of a jump NN glucose prediction algorithm that exploits past glucose concentration data, measured in real-time by a minimally invasive continuous glucose monitoring (CGM) sensor, and information on ingested carbohydrates, supplied by the patient himself or herself. The methodology is assessed by tuning the NN on data of ten T1D individuals and then testing it on a dataset of ten different subjects. Results with a prediction horizon of 30 min show that prediction of glucose concentration in T1D via NN is feasible and sufficiently accurate. The average time anticipation obtained is compatible with the generation of preventive hypoglycemic and hyperglycemic alerts and the improvement of artificial pancreas performance.

  18. Effect of stover fraction and storage method on glucose production during enzymatic hydrolysis.

    PubMed

    Montross, M D; Crofcheck, C L

    2004-05-01

    One avenue for overcoming the economic challenges associated with the production of ethanol from renewable resources is to reduce the cost of the biomass feedstock. The balance between storage costs and benefits depend on the storage method and composition changes of individual stover fractions. Corn stover from bales stored inside and outside of a barn was separated into an interior and exterior layer after approximately 10 months of storage. The cobs, stalks, and leaves and husks were separated, dried, and ground through a 2 mm screen. Stover, sodium acetate (buffer), cellulase, and deionized water were added to 125 ml flasks. The mixture was held at 50 degrees C in an incubator and samples taken for glucose determination. The average glucose concentration after 60 h of hydrolysis from cobs, leaves and husks, and stalks was 10.5, 9.6, and 3.1 g/l, respectively. Cobs, leaves, and husks produced over 300% more glucose than stalks. Storage outside of the barn decreased the glucose production from individual stover components between 4% and 8%. The effect of stover fraction type on glucose production was significant, while the storage treatment effect was not significant. Fractionation of corn stover may be a method to increase the value of corn stover as a feedstock for glucose production.

  19. Glucose-dependent insulinotropic polypeptide directly induces glucose transport in rat skeletal muscle

    PubMed Central

    Snook, Laelie A.; Nelson, Emery M.; Dyck, David J.; Wright, David C.

    2015-01-01

    Several gastrointestinal proteins have been identified to have insulinotropic effects, including glucose-dependent insulinotropic polypeptide (GIP); however, the direct effects of incretins on skeletal muscle glucose transport remain largely unknown. Therefore, the purpose of the current study was to examine the role of GIP on skeletal muscle glucose transport and insulin signaling in rats. Relative to a glucose challenge, a mixed glucose+lipid oral challenge increased circulating GIP concentrations, skeletal muscle Akt phosphorylation, and improved glucose clearance by ∼35% (P < 0.05). These responses occurred without alterations in serum insulin concentrations. In an incubated soleus muscle preparation, GIP directly stimulated glucose transport and increased GLUT4 accumulation on the plasma membrane in the absence of insulin. Moreover, the ability of GIP to stimulate glucose transport was mitigated by the addition of the PI 3-kinase (PI3K) inhibitor wortmannin, suggesting that signaling through PI3K is required for these responses. We also provide evidence that the combined stimulatory effects of GIP and insulin on soleus muscle glucose transport are additive. However, the specific GIP receptor antagonist (Pro3)GIP did not attenuate GIP-stimulated glucose transport, suggesting that GIP is not signaling through its classical receptor. Together, the current data provide evidence that GIP regulates skeletal muscle glucose transport; however, the exact signaling mechanism(s) remain unknown. PMID:26041107

  20. Cell based metabolic barriers to glucose diffusion: macrophages and continuous glucose monitoring.

    PubMed

    Klueh, Ulrike; Frailey, Jackman T; Qiao, Yi; Antar, Omar; Kreutzer, Donald L

    2014-03-01

    It is assumed that MQ are central to glucose sensor bio-fouling and therefore have a major negative impact on continuous glucose monitoring (CGM) performance in vivo. However to our knowledge there is no data in the literature to directly support or refute this assumption. Since glucose and oxygen (O2) are key to glucose sensor function in vivo, understanding and controlling glucose and O2 metabolic activity of MQ is likely key to successful glucose sensor performance. We hypothesized that the accumulation of MQ at the glucose sensor-tissue interface will act as "Cell Based Metabolic Barriers" (CBMB) to glucose diffusing from the interstitial tissue compartment to the implanted glucose sensor and as such creating an artificially low sensor output, thereby compromising sensor function and CGM. Our studies demonstrated that 1) direct injections of MQ at in vivo sensor implantation sites dramatically decreased sensor output (measured in nA), 2) addition of MQ to glucose sensors in vitro resulted in a rapid and dramatic fall in sensor output and 3) lymphocytes did not affect sensor function in vitro or in vivo. These data support our hypothesis that MQ can act as metabolic barriers to glucose and O2 diffusion in vivo and in vitro. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Cell Based Metabolic Barriers to Glucose Diffusion: Macrophages and Continuous Glucose Monitoring

    PubMed Central

    Klueh, Ulrike; Frailey, Jackman; Qiao, Yi; Antar, Omar; Kreutzer, Donald L.

    2014-01-01

    It is assumed that MQ are central to glucose sensor bio-fouling and therefore have a major negative impact on continuous glucose monitoring (CGM) performance in vivo. However to our knowledge there is no data in the literature to directly support or refute this assumption. Since glucose and oxygen (O2) are key to glucose sensor function in vivo, understanding and controlling glucose and O2 metabolic activity of MQ is likely key to successful glucose sensor performance. We hypothesized that the accumulation of MQ at the glucose sensor-tissue interface will act as “Cell Based Metabolic Barriers” (CBMB) to glucose diffusing from the interstitial tissue compartment to the implanted glucose sensor and as such creating an artificially low sensor output, thereby compromising sensor function and CGM. Our studies demonstrated that 1) direct injections of MQ at in vivo sensor implantation sites dramatically decreased sensor output (measured in nA), 2) addition of MQ to glucose sensors in vitro resulted in a rapid and dramatic fall in sensor output and 3) lymphocytes did not affect sensor function in vitro or in vivo. These data support our hypothesis that MQ can act as metabolic barriers to glucose and O2 diffusion in vivo and in vitro. PMID:24461328

  2. Effects of acute intermittent hypoxia on glucose metabolism in awake healthy volunteers

    PubMed Central

    Louis, Mariam; Punjabi, Naresh M.

    2009-01-01

    Accumulating evidence suggests that obstructive sleep apnea is associated with alterations in glucose metabolism. Although the pathophysiology of metabolic dysfunction in obstructive sleep apnea is not well understood, studies of murine models indicate that intermittent hypoxemia has an important contribution. However, corroborating data on the metabolic effects of intermittent hypoxia on glucose metabolism in humans are not available. Thus the primary aim of this study was to characterize the acute effects of intermittent hypoxia on glucose metabolism. Thirteen healthy volunteers were subjected to 5 h of intermittent hypoxia or normoxia during wakefulness in a randomized order on two separate days. The intravenous glucose tolerance test (IVGTT) was used to assess insulin-dependent and insulin-independent measures of glucose disposal. The IVGTT data were analyzed using the minimal model to determine insulin sensitivity (SI) and glucose effectiveness (SG). Drops in oxyhemoglobin saturation were induced during wakefulness at an average rate of 24.3 events/h. Compared with the normoxia condition, intermittent hypoxia was associated with a decrease in SI [4.1 vs. 3.4 (mU/l)−1·min−1; P = 0.0179] and SG (1.9 vs. 1.3 min−1×10−2, P = 0.0065). Despite worsening insulin sensitivity with intermittent hypoxia, pancreatic insulin secretion was comparable between the two conditions. Heart rate variability analysis showed the intermittent hypoxia was associated with a shift in sympathovagal balance toward an increase in sympathetic nervous system activity. The average R-R interval on the electrocardiogram was 919.0 ms during the normoxia condition and 874.4 ms during the intermittent hypoxia condition (P < 0.04). Serum cortisol levels after intermittent hypoxia and normoxia were similar. Hypoxic stress in obstructive sleep apnea may increase the predisposition for metabolic dysfunction by impairing insulin sensitivity, glucose effectiveness, and insulin secretion. PMID

  3. Glucose biosensor based on nanocomposite films of CdTe quantum dots and glucose oxidase.

    PubMed

    Li, Xinyu; Zhou, Yunlong; Zheng, Zhaozhu; Yue, Xiuli; Dai, Zhifei; Liu, Shaoqin; Tang, Zhiyong

    2009-06-02

    A blood glucose sensor has been developed based on the multilayer films of CdTe semiconductor quantum dots (QDs) and glucose oxidase (GOD) by using the layer-by-layer assembly technique. When the composite films were contacted with glucose solution, the photoluminescence of QDs in the films was quickly quenched because the enzyme-catalyzed reaction product (H2O2) of GOD and glucose gave rise to the formation of surface defects on QDs. The quenching rate was a function of the concentration of glucose. The linear range and sensitivity for glucose determination could be adjusted by controlling the layers of QDs and GOD. The biosensor was used to successfully determine the concentration of blood glucose in real serum samples without sample pretreatment and exhibited satisfactory reproducibility and accuracy.

  4. Evaluation of Correlation of Blood Glucose and Salivary Glucose Level in Known Diabetic Patients.

    PubMed

    Gupta, Anjali; Singh, Siddharth Kumar; Padmavathi, B N; Rajan, S Y; Mamatha, G P; Kumar, Sandeep; Roy, Sayak; Sareen, Mohit

    2015-05-01

    Diabetes mellitus is a chronic heterogenous disease in which there is dysregulation of carbohydrates, protein and lipid metabolism; leading to elevated blood glucose levels. The present study was conducted to evaluate the correlation between blood glucose and salivary glucose levels in known diabetic patients and control group and also to evaluate salivary glucose level as a diagnostic tool in diabetic patients. A total number of 250 patients were studied, out of which 212 formed the study group and 38 formed the control group. Among 250 patients, correlation was evaluated between blood glucose and salivary glucose values which on analysis revealed Pearson correlation of 0.073. The p-value was 0.247, which was statistically non significant. Salivary glucose values cannot be considered as a diagnostic tool for diabetic individuals.

  5. Facile fabrication of network film electrodes with ultrathin Au nanowires for nonenzymatic glucose sensing and glucose/O2 fuel cell.

    PubMed

    Yang, Lu; Zhang, Yijia; Chu, Mi; Deng, Wenfang; Tan, Yueming; Ma, Ming; Su, Xiaoli; Xie, Qingji; Yao, Shuozhuo

    2014-02-15

    We report here on the facile fabrication of network film electrodes with ultrathin Au nanowires (AuNWs) and their electrochemical applications for high-performance nonenzymatic glucose sensing and glucose/O2 fuel cell under physiological conditions (pH 7.4, containing 0.15M Cl(-)). AuNWs with an average diameter of ~7 or 2 nm were prepared and can self-assemble into robust network films on common electrodes. The network film electrode fabricated with 2-nm AuNWs exhibits high sensitivity (56.0 μA cm(-2)mM(-1)), low detection limit (20 μM), short response time (within 10s), excellent selectivity, and good storage stability for nonenzymatic glucose sensing. Glucose/O2 fuel cells were constructed using network film electrodes as the anode and commercial Pt/C catalyst modified glassy carbon electrode as cathode. The glucose/O2 fuel cell using 2-nm AuNWs as anode catalyst output a maximum power density of is 126 μW cm(-2), an open-circuit cell voltage of 0.425 V, and a short-circuit current density of 1.34 mA cm(-2), respectively. Due to the higher specific electroactive surface area of 2-nm AuNWs, the network film electrode fabricated with 2-nm AuNWs exhibited higher electrocatalytic activity toward glucose oxidation than the network film electrode fabricated with 7-nm AuNWs. The network film electrode exhibits high electrocatalytic activity toward glucose oxidation under physiological conditions, which is helpful for constructing implantable electronic devices. © 2013 Elsevier B.V. All rights reserved.

  6. Interpreting Bivariate Regression Coefficients: Going beyond the Average

    ERIC Educational Resources Information Center

    Halcoussis, Dennis; Phillips, G. Michael

    2010-01-01

    Statistics, econometrics, investment analysis, and data analysis classes often review the calculation of several types of averages, including the arithmetic mean, geometric mean, harmonic mean, and various weighted averages. This note shows how each of these can be computed using a basic regression framework. By recognizing when a regression model…

  7. Analytic computation of average energy of neutrons inducing fission

    SciTech Connect

    Clark, Alexander Rich

    2016-08-12

    The objective of this report is to describe how I analytically computed the average energy of neutrons that induce fission in the bare BeRP ball. The motivation of this report is to resolve a discrepancy between the average energy computed via the FMULT and F4/FM cards in MCNP6 by comparison to the analytic results.

  8. 47 CFR 1.959 - Computation of average terrain elevation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Section 1.959 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by...) of this chapter, average terrain elevation must be calculated by computer using elevations from a 30... also be done manually, if the results differ significantly from the computer derived averages. (a...

  9. 47 CFR 1.959 - Computation of average terrain elevation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Section 1.959 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by...) of this chapter, average terrain elevation must be calculated by computer using elevations from a 30... also be done manually, if the results differ significantly from the computer derived averages. (a...

  10. 47 CFR 1.959 - Computation of average terrain elevation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Section 1.959 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by...) of this chapter, average terrain elevation must be calculated by computer using elevations from a 30... also be done manually, if the results differ significantly from the computer derived averages. (a...

  11. ACT Average Composite by State: 2000 ACT-Tested Graduates.

    ERIC Educational Resources Information Center

    American Coll. Testing Program, Iowa City, IA.

    This table contains average composite scores by state for high school graduates who took the ACT Assessment in 2000. For each state the percentage of graduates taking the ACT Assessment and the average composite score are given, with the same information for those who completed the recommended core curriculum and those who did not, as well as for…

  12. 7 CFR 701.117 - Average adjusted gross income limitation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 7 2011-01-01 2011-01-01 false Average adjusted gross income limitation. 701.117... Conservation Program § 701.117 Average adjusted gross income limitation. To be eligible for payments issued... the provisions of the Adjusted Gross Income Limitations at 7 CFR part 1400 subpart G. [72 FR 45880...

  13. 7 CFR 701.17 - Average adjusted gross income limitation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Average adjusted gross income limitation. 701.17... RELATED PROGRAMS PREVIOUSLY ADMINISTERED UNDER THIS PART § 701.17 Average adjusted gross income limitation... 9003), each applicant must meet the provisions of the Adjusted Gross Income Limitations at 7 CFR part...

  14. Average Age of Oakton Students in Fall 1978.

    ERIC Educational Resources Information Center

    Kirby, Emily B.

    It has been suggested that the average age of community college students is increasing and colleges should adjust their policies accordingly. In an effort to investigate this assertion, the average age of Oakton Community College students enrolled during the fall 1978 semester was calculated. The relationship between student age and number of…

  15. 7 CFR 5.2 - Marketing season average price data.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 1 2012-01-01 2012-01-01 false Marketing season average price data. 5.2 Section 5.2 Agriculture Office of the Secretary of Agriculture DETERMINATION OF PARITY PRICES § 5.2 Marketing season... adjusted base prices and, therefore, marketing season average prices will be used. An allowance for any...

  16. 42 CFR 423.279 - National average monthly bid amount.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... each MA-PD plan described in section 1851(a)(2)(A)(i) of the Act. The calculation does not include bids... section 1876(h) of the Act. (b) Calculation of weighted average. (1) The national average monthly bid... defined in § 422.258(c)(1) of this chapter) and the denominator equal to the total number of Part D...

  17. 42 CFR 423.279 - National average monthly bid amount.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... each MA-PD plan described in section 1851(a)(2)(A)(i) of the Act. The calculation does not include bids... section 1876(h) of the Act. (b) Calculation of weighted average. (1) The national average monthly bid... defined in § 422.258(c)(1) of this chapter) and the denominator equal to the total number of Part D...

  18. 42 CFR 423.279 - National average monthly bid amount.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... bid amounts for each prescription drug plan (not including fallbacks) and for each MA-PD plan...(h) of the Act. (b) Calculation of weighted average. (1) The national average monthly bid amount is a....258(c)(1) of this chapter) and the denominator equal to the total number of Part D eligible...

  19. 42 CFR 423.279 - National average monthly bid amount.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... each MA-PD plan described in section 1851(a)(2)(A)(i) of the Act. The calculation does not include bids... section 1876(h) of the Act. (b) Calculation of weighted average. (1) The national average monthly bid... defined in § 422.258(c)(1) of this chapter) and the denominator equal to the total number of Part D...

  20. 42 CFR 423.279 - National average monthly bid amount.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... bid amounts for each prescription drug plan (not including fallbacks) and for each MA-PD plan...(h) of the Act. (b) Calculation of weighted average. (1) The national average monthly bid amount is a....258(c)(1) of this chapter) and the denominator equal to the total number of Part D eligible...

  1. 7 CFR 51.2548 - Average moisture content determination.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Average moisture content determination. 51.2548... moisture content determination. (a) Determining average moisture content of the lot is not a requirement of... connection with grade analysis or as a separate determination. (b) Nuts shall be obtained from a randomly...

  2. 18 CFR 301.7 - Average System Cost methodology functionalization.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 18 Conservation of Power and Water Resources 1 2014-04-01 2014-04-01 false Average System Cost methodology functionalization. 301.7 Section 301.7 Conservation of Power and Water Resources FEDERAL ENERGY... ACT § 301.7 Average System Cost methodology functionalization. (a) Functionalization of each Account...

  3. 18 CFR 301.7 - Average System Cost methodology functionalization.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 18 Conservation of Power and Water Resources 1 2012-04-01 2012-04-01 false Average System Cost methodology functionalization. 301.7 Section 301.7 Conservation of Power and Water Resources FEDERAL ENERGY... ACT § 301.7 Average System Cost methodology functionalization. (a) Functionalization of each Account...

  4. 18 CFR 301.7 - Average System Cost methodology functionalization.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 1 2013-04-01 2013-04-01 false Average System Cost methodology functionalization. 301.7 Section 301.7 Conservation of Power and Water Resources FEDERAL ENERGY... ACT § 301.7 Average System Cost methodology functionalization. (a) Functionalization of each Account...

  5. 18 CFR 301.7 - Average System Cost methodology functionalization.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 18 Conservation of Power and Water Resources 1 2011-04-01 2011-04-01 false Average System Cost methodology functionalization. 301.7 Section 301.7 Conservation of Power and Water Resources FEDERAL ENERGY... ACT § 301.7 Average System Cost methodology functionalization. (a) Functionalization of each Account...

  6. A glucose oxidase-coupled DNAzyme sensor for glucose detection in tears and saliva.

    PubMed

    Liu, Chengcheng; Sheng, Yongjie; Sun, Yanhong; Feng, Junkui; Wang, Shijin; Zhang, Jin; Xu, Jiacui; Jiang, Dazhi

    2015-08-15

    Biosensors have been widely investigated and utilized in a variety of fields ranging from environmental monitoring to clinical diagnostics. Glucose biosensors have triggered great interest and have been widely exploited since glucose determination is essential for diabetes diagnosis. In here, we designed a novel dual-enzyme biosensor composed of glucose oxidase (GOx) and pistol-like DNAzyme (PLDz) to detect glucose levels in tears and saliva. First, GOx, as a molecular recognition element, catalyzes the oxidation of glucose forming H2O2; then PLDz recognizes the produced H2O2 as a secondary signal and performs a self-cleavage reaction promoted by Mn(2+), Co(2+) and Cu(2+). Thus, detection of glucose could be realized by monitoring the cleavage rate of PLDz. The slope of the cleavage rate of PLDz versus glucose concentration curve was fitted with a Double Boltzmann equation, with a range of glucose from 100 nM to 10mM and a detection limit of 5 μM. We further applied the GOx-PLDz 1.0 biosensor for glucose detection in tears and saliva, glucose levels in which are 720±81 μM and 405±56 μM respectively. Therefore, the GOx-PLDz 1.0 biosensor is able to determine glucose levels in tears and saliva as a noninvasive glucose biosensor, which is important for diabetic patients with frequent/continuous glucose monitoring requirements. In addition, induction of DNAzyme provides a new approach in the development of glucose biosensors. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Ventromedial hypothalamic glucose sensing and glucose homeostasis vary throughout the estrous cycle

    PubMed Central

    Santiago, Ammy M.; Clegg, Deborah J.; Routh, Vanessa H.

    2016-01-01

    Objective 17β-Estradiol (17βE) regulates glucose homeostasis in part by centrally mediated mechanisms. In female rodents, the influence of the ovarian cycle on hypoglycemia counterregulation and glucose tolerance is unclear. We found previously that in prepubertal females, 17βE modulates glucose sensing in nonadapting glucose-inhibited (GI) and adapting GI (AdGI) neurons within the ventrolateral portion of the ventromedial nucleus (VL-VMN). Nonadapting GI neurons persistently decrease their activity as glucose increases while AdGI neurons transiently respond to a glucose increase. To begin to understand if endogenous fluctuations in estrogen levels across the estrous cycle impact hypothalamic glucose sensing and glucose homeostasis, we assessed whether hypoglycemia counterregulation and glucose tolerance differed across the phases of the estrous cycle. We hypothesized that the response to insulin-induced hypoglycemia (IIH) and/or glucose tolerance would vary throughout the estrous cycle according to changes in 17βE availability. Moreover, that these changes would correlate with estrous-dependent changes in the glucose sensitivity of VL-VMN glucose-sensing neurons (GSNs). Methods These hypotheses were tested in female mice by measuring the response to IIH, glucose tolerance and the glucose sensitivity of VL-VMN GSNs during each phase of the estrous cycle. Furthermore, a physiological brain concentration of 17βE seen during proestrus was acutely applied to brain slices isolated on the day of diestrous and the response to low glucose in VL-VMN GSNs was assayed. Results The response to IIH was strongest during diestrous. The response of nonadapting GI and AdGI neurons to a glucose decrease from 2.5 to 0.5mM also peaked during diestrous; an effect which was blunted by the addition of 17βE. In contrast, the glucose sensitivity of the subpopulation of GSNs which are excited by glucose (GE) was not affected by estrous phase or exogenous 17βE application. Conclusion

  8. Ventromedial hypothalamic glucose sensing and glucose homeostasis vary throughout the estrous cycle.

    PubMed

    Santiago, Ammy M; Clegg, Deborah J; Routh, Vanessa H

    2016-12-01

    17β-Estradiol (17βE) regulates glucose homeostasis in part by centrally mediated mechanisms. In female rodents, the influence of the ovarian cycle on hypoglycemia counterregulation and glucose tolerance is unclear. We found previously that in prepubertal females, 17βE modulates glucose sensing in nonadapting glucose-inhibited (GI) and adapting GI (AdGI) neurons within the ventrolateral portion of the ventromedial nucleus (VL-VMN). Nonadapting GI neurons persistently decrease their activity as glucose increases while AdGI neurons transiently respond to a glucose increase. To begin to understand if endogenous fluctuations in estrogen levels across the estrous cycle impact hypothalamic glucose sensing and glucose homeostasis, we assessed whether hypoglycemia counterregulation and glucose tolerance differed across the phases of the estrous cycle. We hypothesized that the response to insulin-induced hypoglycemia (IIH) and/or glucose tolerance would vary throughout the estrous cycle according to changes in 17βE availability. Moreover, that these changes would correlate with estrous-dependent changes in the glucose sensitivity of VL-VMN glucose-sensing neurons (GSNs). These hypotheses were tested in female mice by measuring the response to IIH, glucose tolerance and the glucose sensitivity of VL-VMN GSNs during each phase of the estrous cycle. Furthermore, a physiological brain concentration of 17βE seen during proestrus was acutely applied to brain slices isolated on the day of diestrous and the response to low glucose in VL-VMN GSNs was assayed. The response to IIH was strongest during diestrous. The response of nonadapting GI and AdGI neurons to a glucose decrease from 2.5 to 0.5mM also peaked during diestrous; an effect which was blunted by the addition of 17βE. In contrast, the glucose sensitivity of the subpopulation of GSNs which are excited by glucose (GE) was not affected by estrous phase or exogenous 17βE application. These data suggest that physiological

  9. LANDSAT-4 horizon scanner full orbit data averages

    NASA Technical Reports Server (NTRS)

    Stanley, J. P.; Bilanow, S.

    1983-01-01

    Averages taken over full orbit data spans of the pitch and roll residual measurement errors of the two conical Earth sensors operating on the LANDSAT 4 spacecraft are described. The variability of these full orbit averages over representative data throughtout the year is analyzed to demonstrate the long term stability of the sensor measurements. The data analyzed consist of 23 segments of sensor measurements made at 2 to 4 week intervals. Each segment is roughly 24 hours in length. The variation of full orbit average as a function of orbit within a day as a function of day of year is examined. The dependence on day of year is based on association the start date of each segment with the mean full orbit average for the segment. The peak-to-peak and standard deviation values of the averages for each data segment are computed and their variation with day of year are also examined.

  10. Some series of intuitionistic fuzzy interactive averaging aggregation operators.

    PubMed

    Garg, Harish

    2016-01-01

    In this paper, some series of new intuitionistic fuzzy averaging aggregation operators has been presented under the intuitionistic fuzzy sets environment. For this, some shortcoming of the existing operators are firstly highlighted and then new operational law, by considering the hesitation degree between the membership functions, has been proposed to overcome these. Based on these new operation laws, some new averaging aggregation operators namely, intuitionistic fuzzy Hamacher interactive weighted averaging, ordered weighted averaging and hybrid weighted averaging operators, labeled as IFHIWA, IFHIOWA and IFHIHWA respectively has been proposed. Furthermore, some desirable properties such as idempotency, boundedness, homogeneity etc. are studied. Finally, a multi-criteria decision making method has been presented based on proposed operators for selecting the best alternative. A comparative concelebration between the proposed operators and the existing operators are investigated in detail.

  11. Average cross-responses in correlated financial markets

    NASA Astrophysics Data System (ADS)

    Wang, Shanshan; Schäfer, Rudi; Guhr, Thomas

    2016-09-01

    There are non-vanishing price responses across different stocks in correlated financial markets, reflecting non-Markovian features. We further study this issue by performing different averages, which identify active and passive cross-responses. The two average cross-responses show different characteristic dependences on the time lag. The passive cross-response exhibits a shorter response period with sizeable volatilities, while the corresponding period for the active cross-response is longer. The average cross-responses for a given stock are evaluated either with respect to the whole market or to different sectors. Using the response strength, the influences of individual stocks are identified and discussed. Moreover, the various cross-responses as well as the average cross-responses are compared with the self-responses. In contrast to the short-memory trade sign cross-correlations for each pair of stocks, the sign cross-correlations averaged over different pairs of stocks show long memory.

  12. Mechanisms of the effects of grains on insulin and glucose responses.

    PubMed

    Hallfrisch, J; Facn; Behall, K M

    2000-06-01

    Consumption of a number of grains and grain extracts has been reported to control or improve glucose tolerance and reduce insulin resistance. The inability of the body to maintain normal glucose levels or to require excessive levels of insulin to do so has been called glucose intolerance, impaired glucose tolerance and insulin resistance. These conditions are associated with obesity and may be preliminary steps in the progression to type 2 diabetes mellitus. Although dietary goals recommend the consumption of three servings of whole grains per day, average consumption in the United States is less than one serving per day. There are a number of mechanisms by which grains may improve glucose metabolism and delay or prevent the progression of impaired glucose tolerance to insulin resistance and diabetes. These mechanisms are related to the physical properties and structure of grains. The composition of the grain, including particle size, amount and type of fiber, viscosity, amylose and amylopectin content all affect the metabolism of carbohydrates from grains. Increasing whole grain intake in the population can result in improved glucose metabolism and delay or reduce the risk of developing type 2 diabetes mellitus. Whole grains can provide a substantial contribution to the improvement of the diets of Americans. A number of whole grain foods and grain fiber sources are beneficial in reduction of insulin resistance and improvement in glucose tolerance. Form, amount and method of cooking of these foods as well as the health characteristics, age and gender of the group of subjects studied are all important factors in the effectiveness of the foods in altering these responses. Dietary recommendations of health organizations suggest consumption of three servings a day of whole grain foods; however, Americans generally fall below this standard. Recent research using various grains and grain products effective in improving insulin resistance or lowering glycemic index will

  13. Association of late-night carbohydrate intake with glucose tolerance among pregnant African American women.

    PubMed

    Chandler-Laney, Paula C; Schneider, Camille R; Gower, Barbara A; Granger, Wesley M; Mancuso, Melissa S; Biggio, Joseph R

    2016-10-01

    Obesity and late-night food consumption are associated with impaired glucose tolerance. Late-night carbohydrate consumption may be particularly detrimental during late pregnancy because insulin sensitivity declines as pregnancy progresses. Further, women who were obese (Ob) prior to pregnancy have lower insulin sensitivity than do women of normal weight (NW). The aim of this study is to test the hypothesis that night-time carbohydrate consumption is associated with poorer glucose tolerance in late pregnancy and that this association would be exacerbated among Ob women. Forty non-diabetic African American women were recruited based upon early pregnancy body mass index (NW, <25 kg m(-2) ; Ob, ≥30 kg m(-2) ). Third trimester free-living dietary intake was assessed by food diary, and indices of glucose tolerance and insulin action were assessed during a 75-g oral glucose tolerance test. Women in the Ob group reported greater average 24-h energy intake (3055 kcal vs. 2415 kcal, P < 0.05). Across the whole cohort, night-time, but not day-time, carbohydrate intake was positively associated with glucose concentrations after the glucose load and inversely associated with early phase insulin secretion (P < 0.05). Multiple linear regression modelling within each weight group showed that the associations among late-night carbohydrate intake, glucose concentrations and insulin secretion were present only in the Ob group. This is the first study to report an association of night-time carbohydrate intake specifically on glucose tolerance and insulin action during pregnancy. If replicated, these results suggest that late-night carbohydrate intake may be a potential target for intervention to improve metabolic health of Ob women in late pregnancy. © 2015 John Wiley & Sons Ltd.

  14. A non-invasive blood glucose meter design using multi-type sensors

    NASA Astrophysics Data System (ADS)

    Nguyen, D.; Nguyen, Hienvu; Roveda, Janet

    2012-10-01

    In this paper, we present a design of a multi optical modalities blood glucose monitor. The Monte Carlo tissues optics simulation with typical human skin model suggests the SNR ratio for a detector sensor is 104 with high sensitivity that can detect low blood sugar limit at 1 mMole/dL ( <20 mg/dL). A Bayesian filtering algorithm is proposed for multisensor fusion to identify whether e user has the danger of having diabetes. The new design has real time response (on the average of 2 minutes) and provides great potential to perform real time monitoring for blood glucose.

  15. Noninvasive glucose sensing by transcutaneous Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Shih, Wei-Chuan; Bechtel, Kate L.; Rebec, Mihailo V.

    2015-05-01

    We present the development of a transcutaneous Raman spectroscopy system and analysis algorithm for noninvasive glucose sensing. The instrument and algorithm were tested in a preclinical study in which a dog model was used. To achieve a robust glucose test system, the blood levels were clamped for periods of up to 45 min. Glucose clamping and rise/fall patterns have been achieved by injecting glucose and insulin into the ear veins of the dog. Venous blood samples were drawn every 5 min and a plasma glucose concentration was obtained and used to maintain the clamps, to build the calibration model, and to evaluate the performance of the system. We evaluated the utility of the simultaneously acquired Raman spectra to be used to determine the plasma glucose values during the 8-h experiment. We obtained prediction errors in the range of ˜1.5-2 mM. These were in-line with a best-case theoretical estimate considering the limitations of the signal-to-noise ratio estimates. As expected, the transition regions of the clamp study produced larger predictive errors than the stable regions. This is related to the divergence of the interstitial fluid (ISF) and plasma glucose values during those periods. Two key contributors to error beside the ISF/plasma difference were photobleaching and detector drift. The study demonstrated the potential of Raman spectroscopy in noninvasive applications and provides areas where the technology can be improved in future studies.

  16. The facilitated component of intestinal glucose absorption

    PubMed Central

    Kellett, George L

    2001-01-01

    Over the last decade, a debate has developed about the mechanism of the passive or ‘diffusive’ component of intestinal glucose absorption and, indeed, whether it even exists. Pappenheimer and colleagues have proposed that paracellular solvent drag contributes a passive component, which, at high concentrations of sugars similar to those in the jejunal lumen immediately after a meal, is severalfold greater than the active component mediated by the Na+-glucose cotransporter SGLT1. On the other hand, Ferraris & Diamond maintain that the kinetics of glucose absorption can be explained solely in terms of SGLT1 and that a passive or paracellular component plays little, if any, part. Recently, we have provided new evidence that the passive component of glucose absorption exists, but is in fact facilitated since it is mediated by the rapid, glucose-dependent activation and recruitment of the facilitative glucose transporter GLUT2 to the brush-border membrane; regulation involves a protein kinase C (PKC)-dependent pathway activated by glucose transport through SGLT1 and also involves mitogen-activated protein kinase (MAP kinase) signalling pathways. This topical review seeks to highlight the significant points of the debate, to show how our proposals on GLUT2 impact on different aspects of the debate and to look at the regulatory events that are likely to be involved in the short-term regulation of sugar absorption during the assimilation of a meal. PMID:11251042

  17. Noninvasive glucose sensing by transcutaneous Raman spectroscopy.

    PubMed

    Shih, Wei-Chuan; Bechtel, Kate L; Rebec, Mihailo V

    2015-05-01

    We present the development of a transcutaneous Raman spectroscopy system and analysis algorithm for noninvasive glucose sensing. The instrument and algorithm were tested in a preclinical study in which a dog model was used. To achieve a robust glucose test system, the blood levels were clamped for periods of up to 45 min. Glucose clamping and rise/fall patterns have been achieved by injecting glucose and insulin into the ear veins of the dog. Venous blood samples were drawn every 5 min and a plasma glucose concentration was obtained and used to maintain the clamps, to build the calibration model, and to evaluate the performance of the system. We evaluated the utility of the simultaneously acquired Raman spectra to be used to determine the plasma glucose values during the 8-h experiment. We obtained prediction errors in the range of ~1.5-2  mM. These were in-line with a best-case theoretical estimate considering the limitations of the signal-to-noise ratio estimates. As expected, the transition regions of the clamp study produced larger predictive errors than the stable regions. This is related to the divergence of the interstitial fluid (ISF) and plasma glucose values during those periods. Two key contributors to error beside the ISF/plasma difference were photobleaching and detector drift. The study demonstrated the potential of Raman spectroscopy in noninvasive applications and provides areas where the technology can be improved in future studies.

  18. Glucose metabolism in the developing brain.

    PubMed

    Vannucci, R C; Vannucci, S J

    2000-04-01

    As in adults, glucose is the predominant cerebral energy fuel for the fetus and newborn. Studies in experimental animals and humans indicate that cerebral glucose utilization initially is low and increases with maturation with increasing regional heterogeneity. The increases in cerebral glucose utilization with advancing age occurs as a consequence of increasing functional activity and cerebral energy demands. The levels of expression of the 2 primary facilitative glucose transporter proteins in brain, GLUT1 (blood-brain barrier and glia) and GLUT3 (neuronal), display a similar maturational pattern. Alternate cerebral energy fuels, specifically the ketone bodies and lactate, can substitute for glucose, especially during hypoglycemia, thereby protecting the immature brain from potential untoward effects of hypoglycemia. Unlike adults, glucose supplementation during hypoxia-ischemia is protective in the immature brain, whereas hypoglycemia is deleterious. Accordingly, glucose plays a critical role in the developing brain, not only as the primary substrate for energy production but also to allow for normal biosynthetic processes to proceed.

  19. Exercising Tactically for Taming Postmeal Glucose Surges.

    PubMed

    Chacko, Elsamma

    2016-01-01

    This review seeks to synthesize data on the timing, intensity, and duration of exercise found scattered over some 39 studies spanning 3+ decades into optimal exercise conditions for controlling postmeal glucose surges. The results show that a light aerobic exercise for 60 min or moderate activity for 20-30 min starting 30 min after meal can efficiently blunt the glucose surge, with minimal risk of hypoglycemia. Exercising at other times could lead to glucose elevation caused by counterregulation. Adding a short bout of resistance exercise of moderate intensity (60%-80%  VO2max) to the aerobic activity, 2 or 3 times a week as recommended by the current guidelines, may also help with the lowering of glucose surges. On the other hand, high-intensity exercise (>80%  VO2max) causes wide glucose fluctuations and its feasibility and efficacy for glucose regulation remain to be ascertained. Promoting the kind of physical activity that best counters postmeal hyperglycemia is crucial because hundreds of millions of diabetes patients living in developing countries and in the pockets of poverty in the West must do without medicines, supplies, and special diets. Physical activity is the one tool they may readily utilize to tame postmeal glucose surges. Exercising in this manner does not violate any of the current guidelines, which encourage exercise any time.

  20. Standardization versus customization of glucose reporting.

    PubMed

    Rodbard, David

    2013-05-01

    Bergenstal et al. (Diabetes Technol Ther 2013;15:198-211) described an important approach toward standardization of reporting and analysis of continuous glucose monitoring and self-monitoring of blood glucose (SMBG) data. The ambulatory glucose profile (AGP), a composite display of glucose by time of day that superimposes data from multiple days, is perhaps the most informative and useful of the many graphical approaches to display glucose data. However, the AGP has limitations; some variations are desirable and useful. Synchronization with respect to meals, traditionally used in glucose profiles for SMBG data, can improve characterization of postprandial glucose excursions. Several other types of graphical display are available, and recently developed ones can augment the information provided by the AGP. There is a need to standardize the parameters describing glycemic variability and cross-validate the available computer programs that calculate glycemic variability. Clinical decision support software can identify and prioritize clinical problems, make recommendations for modifications of therapy, and explain its justification for those recommendations. The goal of standardization is challenging in view of the diversity of clinical situations and of computing and display platforms and software. Standardization is desirable but must be done in a manner that permits flexibility and fosters innovation.

  1. Glucose-6-phosphate dehydrogenase deficiency.

    PubMed

    Cappellini, M D; Fiorelli, G

    2008-01-05

    Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common human enzyme defect, being present in more than 400 million people worldwide. The global distribution of this disorder is remarkably similar to that of malaria, lending support to the so-called malaria protection hypothesis. G6PD deficiency is an X-linked, hereditary genetic defect due to mutations in the G6PD gene, which cause functional variants with many biochemical and clinical phenotypes. About 140 mutations have been described: most are single base changes, leading to aminoacid substitutions. The most frequent clinical manifestations of G6PD deficiency are neonatal jaundice, and acute haemolytic anaemia, which is usually triggered by an exogenous agent. Some G6PD variants cause chronic haemolysis, leading to congenital non-spherocytic haemolytic anaemia. The most effective management of G6PD deficiency is to prevent haemolysis by avoiding oxidative stress. Screening programmes for the disorder are undertaken, depending on the prevalence of G6PD deficiency in a particular community.

  2. Continuous Glucose Monitoring: Impact on Hypoglycemia.

    PubMed

    van Beers, Cornelis A J; DeVries, J Hans

    2016-11-01

    The necessity of strict glycemic control is unquestionable. However, hypoglycemia remains a major limiting factor in achieving satisfactory glucose control, and evidence is mounting to show that hypoglycemia is not benign. Over the past decade, evidence has consistently shown that real-time continuous glucose monitoring improves glycemic control in terms of lowering glycated hemoglobin levels. However, real-time continuous glucose monitoring has not met the expectations of the diabetes community with regard to hypoglycemia prevention. The earlier trials did not demonstrate any effect on either mild or severe hypoglycemia and the effect of real-time continuous glucose monitoring on nocturnal hypoglycemia was often not reported. However, trials specifically designed to reduce hypoglycemia in patients with a high hypoglycemia risk have demonstrated a reduction in hypoglycemia, suggesting that real-time continuous glucose monitoring can prevent hypoglycemia when it is specifically used for that purpose. Moreover, the newest generation of diabetes technology currently available commercially, namely sensor-augmented pump therapy with a (predictive) low glucose suspend feature, has provided more convincing evidence for hypoglycemia prevention. This article provides an overview of the hypoglycemia outcomes of randomized controlled trials that investigate the effect of real-time continuous glucose monitoring alone or sensor-augmented pump therapy with a (predictive) low glucose suspend feature. Furthermore, several possible explanations are provided why trials have not shown a reduction in severe hypoglycemia. In addition, existing evidence is presented of real-time continuous glucose monitoring in patients with impaired awareness of hypoglycemia who have the highest risk of severe hypoglycemia. © 2016 Diabetes Technology Society.

  3. Programmable noise bandwidth reduction by means of digital averaging

    NASA Technical Reports Server (NTRS)

    Poklemba, John J. (Inventor)

    1993-01-01

    Predetection noise bandwidth reduction is effected by a pre-averager capable of digitally averaging the samples of an input data signal over two or more symbols, the averaging interval being defined by the input sampling rate divided by the output sampling rate. As the averaged sample is clocked to a suitable detector at a much slower rate than the input signal sampling rate the noise bandwidth at the input to the detector is reduced, the input to the detector having an improved signal to noise ratio as a result of the averaging process, and the rate at which such subsequent processing must operate is correspondingly reduced. The pre-averager forms a data filter having an output sampling rate of one sample per symbol of received data. More specifically, selected ones of a plurality of samples accumulated over two or more symbol intervals are output in response to clock signals at a rate of one sample per symbol interval. The pre-averager includes circuitry for weighting digitized signal samples using stored finite impulse response (FIR) filter coefficients. A method according to the present invention is also disclosed.

  4. Model averaging techniques for quantifying conceptual model uncertainty.

    PubMed

    Singh, Abhishek; Mishra, Srikanta; Ruskauff, Greg

    2010-01-01

    In recent years a growing understanding has emerged regarding the need to expand the modeling paradigm to include conceptual model uncertainty for groundwater models. Conceptual model uncertainty is typically addressed by formulating alternative model conceptualizations and assessing their relative likelihoods using statistical model averaging approaches. Several model averaging techniques and likelihood measures have been proposed in the recent literature for this purpose with two broad categories--Monte Carlo-based techniques such as Generalized Likelihood Uncertainty Estimation or GLUE (Beven and Binley 1992) and criterion-based techniques that use metrics such as the Bayesian and Kashyap Information Criteria (e.g., the Maximum Likelihood Bayesian Model Averaging or MLBMA approach proposed by Neuman 2003) and Akaike Information Criterion-based model averaging (AICMA) (Poeter and Anderson 2005). These different techniques can often lead to significantly different relative model weights and ranks because of differences in the underlying statistical assumptions about the nature of model uncertainty. This paper provides a comparative assessment of the four model averaging techniques (GLUE, MLBMA with KIC, MLBMA with BIC, and AIC-based model averaging) mentioned above for the purpose of quantifying the impacts of model uncertainty on groundwater model predictions. Pros and cons of each model averaging technique are examined from a practitioner's perspective using two groundwater modeling case studies. Recommendations are provided regarding the use of these techniques in groundwater modeling practice.

  5. The causal meaning of Fisher’s average effect

    PubMed Central

    LEE, JAMES J.; CHOW, CARSON C.

    2013-01-01

    Summary In order to formulate the Fundamental Theorem of Natural Selection, Fisher defined the average excess and average effect of a gene substitution. Finding these notions to be somewhat opaque, some authors have recommended reformulating Fisher’s ideas in terms of covariance and regression, which are classical concepts of statistics. We argue that Fisher intended his two averages to express a distinction between correlation and causation. On this view, the average effect is a specific weighted average of the actual phenotypic changes that result from physically changing the allelic states of homologous genes. We show that the statistical and causal conceptions of the average effect, perceived as inconsistent by Falconer, can be reconciled if certain relationships between the genotype frequencies and non-additive residuals are conserved. There are certain theory-internal considerations favouring Fisher’s original formulation in terms of causality; for example, the frequency-weighted mean of the average effects equaling zero at each locus becomes a derivable consequence rather than an arbitrary constraint. More broadly, Fisher’s distinction between correlation and causation is of critical importance to gene-trait mapping studies and the foundations of evolutionary biology. PMID:23938113

  6. It's not just average faces that are attractive: computer-manipulated averageness makes birds, fish, and automobiles attractive.

    PubMed

    Halberstadt, Jamin; Rhodes, Gillian

    2003-03-01

    Average faces are attractive. We sought to distinguish whether this preference is an adaptation for finding high-quality mates (the direct selection account) or whether it reflects more general information-processing mechanisms. In three experiments, we examined the attractiveness of birds, fish, and automobiles whose averageness had been manipulated using digital image manipulation techniques common in research on facial attractiveness. Both manipulated averageness and rated averageness were strongly associated with attractiveness in all three stimulus categories. In addition, for birds and fish, but not for automobiles, the correlation between subjective averageness and attractiveness remained significant when the effect of subjective familiarity was partialled out. The results suggest that at least two mechanisms contribute to the attractiveness of average exemplars. One is a general preference for familiar stimuli, which contributes to the appeal of averageness in all three categories. The other is a preference for averageness per se, which was found for birds and fish, but not for automobiles, and may reflect a preference for features signaling genetic quality in living organisms, including conspecifics.

  7. 40 CFR 600.510-12 - Calculation of average fuel economy and average carbon-related exhaust emissions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Calculation of average fuel economy and average carbon-related exhaust emissions. 600.510-12 Section 600.510-12 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) ENERGY POLICY FUEL ECONOMY AND CARBON-RELATED EXHAUST EMISSIONS OF MOTOR VEHICLES Fuel Economy Regulation...

  8. Dynamic Testing of Gifted and Average-Ability Children's Analogy Problem Solving: Does Executive Functioning Play a Role?

    ERIC Educational Resources Information Center

    Vogelaar, Bart; Bakker, Merel; Hoogeveen, Lianne; Resing, Wilma C. M.

    2017-01-01

    In this study, dynamic testing principles were applied to examine progression of analogy problem solving, the roles that cognitive flexibility and metacognition play in children's progression as well as training benefits, and instructional needs of 7- to 8-year-old gifted and average-ability children. Utilizing a pretest training posttest control…

  9. Structuring Collaboration in Mixed-Ability Groups to Promote Verbal Interaction, Learning, and Motivation of Average-Ability Students

    ERIC Educational Resources Information Center

    Saleh, Mohammad; Lazonder, Ard W.; Jong, Ton de

    2007-01-01

    Average-ability students often do not take full advantage of learning in mixed-ability groups because they hardly engage in the group interaction. This study examined whether structuring collaboration by group roles and ground rules for helping behavior might help overcome this participatory inequality. In a plant biology course, heterogeneously…

  10. Blood-Brain Glucose Transfer: Repression in Chronic Hyperglycemia

    NASA Astrophysics Data System (ADS)

    Gjedde, Albert; Crone, Christian

    1981-10-01

    Diabetic patients with increased plasma glucose concentrations may develop cerebral symptoms of hypoglycemia when their plasma glucose is rapidly lowered to normal concentrations. The symptoms may indicate insufficient transport of glucose from blood to brain. In rats with chronic hyperglycemia the maximum glucose transport capacity of the blood-brain barrier decreased from 400 to 290 micromoles per 100 grams per minute. When plasma glucose was lowered to normal values, the glucose transport rate into brain was 20 percent below normal. This suggests that repressive changes of the glucose transport mechanism occur in brain endothelial cells in response to increased plasma glucose.

  11. Glucose oxidase probe as a surface-enhanced Raman scattering sensor for glucose.

    PubMed

    Qi, Guohua; Wang, Yi; Zhang, Biying; Sun, Dan; Fu, Cuicui; Xu, Weiqing; Xu, Shuping

    2016-10-01

    Glucose oxidase (GOx) possessing a Raman-active chromophore (flavin adenine dinucleotide) is used as a signal reporter for constructing a highly specific "turn off" surface-enhanced Raman scattering (SERS) sensor for glucose. This sensing chip is made by the electrostatic assembly of GOx over silver nanoparticle (Ag NP)-functionalized SERS substrate through a positively charged polyelectrolyte linker under the pH of 6.86. To trace glucose in blood serum, owing to the reduced pH value caused by the production of gluconic acid in the GOx-catalyzed oxidation reaction, the bonding force between GOx and polyelectrolyte weakens, making GOx drop off from the sensing chip. As a result, the SERS intensity of GOx on the chip decreases along with the concentration of glucose. This glucose SERS sensor exhibits excellent selectivity based on the specific GOx/glucose catalysis reaction and high sensitivity to 1.0 μM. The linear sensing range is 2.0-14.0 mM, which also meets the requirement on the working range of the human blood glucose detection. Using GOx as a probe shows superiority over other organic probes because GOx almost has no toxicity to the biological system. This sensing mechanism can be applied for intracellular in vivo SERS monitoring of glucose in the future. Graphical abstract Glucose oxidase is used as a Raman signal reporter for constructing a highly specific glucose surface-enhanced Raman scattering (SERS) sensor.

  12. Hepatic glucose sensing is required to preserve β cell glucose competence

    PubMed Central

    Seyer, Pascal; Vallois, David; Poitry-Yamate, Carole; Schütz, Frédéric; Metref, Salima; Tarussio, David; Maechler, Pierre; Staels, Bart; Lanz, Bernard; Grueter, Rolf; Decaris, Julie; Turner, Scott; da Costa, Anabela; Preitner, Frédéric; Minehira, Kaori; Foretz, Marc; Thorens, Bernard

    2013-01-01

    Liver glucose metabolism plays a central role in glucose homeostasis and may also regulate feeding and energy expenditure. Here we assessed the impact of glucose transporter 2 (Glut2) gene inactivation in adult mouse liver (LG2KO mice). Loss of Glut2 suppressed hepatic glucose uptake but not glucose output. In the fasted state, expression of carbohydrate-responsive element-binding protein (ChREBP) and its glycolytic and lipogenic target genes was abnormally elevated. Feeding, energy expenditure, and insulin sensitivity were identical in LG2KO and control mice. Glucose tolerance was initially normal after Glut2 inactivation, but LG2KO mice exhibited progressive impairment of glucose-stimulated insulin secretion even though β cell mass and insulin content remained normal. Liver transcript profiling revealed a coordinated downregulation of cholesterol biosynthesis genes in LG2KO mice that was associated with reduced hepatic cholesterol in fasted mice and reduced bile acids (BAs) in feces, with a similar trend in plasma. We showed that chronic BAs or farnesoid X receptor (FXR) agonist treatment of primary islets increases glucose-stimulated insulin secretion, an effect not seen in islets from Fxr–/– mice. Collectively, our data show that glucose sensing by the liver controls β cell glucose competence and suggest BAs as a potential mechanistic link. PMID:23549084

  13. Glucose-sensitive silicone hydrogel contact lens toward tear glucose monitoring.

    PubMed

    Badugu, Ramachandram; Reece, Edward Albert; Lakowicz, Joseph R

    2018-05-01

    Accurate and reliable monitoring of blood glucose is needed for the treatment of diabetes, which has many challenges, including lack of patient compliance. Measuring tear glucose is an alternative to traditional finger-stick tests used to track blood sugar levels, but glucose sensing using tears has yet to be achieved. We report a methodology for possible tear glucose monitoring using glucose-sensitive silicone hydrogel (SiHG) contact lenses, the primary type of lenses available in today's market. Initially, we assessed the interpenetrating polymer network, with nearly pure silicone and water regions, existing in the SiHGs using a polarity-sensitive probe Prodan. We then synthesized a glucose-sensitive fluorophore Quin-C18 with a hydrophobic side chain for localization of probe at the interfacial region. Using our glucose-sensing contact lens, we were able to measure varying concentrations of glucose in an in-vitro system. The Quin-C18 strongly bound to the lenses with insignificant leaching even after multiple rinses. The lenses displayed a similar response to glucose after three months of storage in water. This study demonstrates that it may be possible to develop a contact lens for continuous glucose monitoring in the near term, using our concept of fluorophore binding at the silicone-water interface. (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

  14. Resistin modulates glucose uptake and glucose transporter-1 (GLUT-1) expression in trophoblast cells.

    PubMed

    Di Simone, Nicoletta; Di Nicuolo, Fiorella; Marzioni, Daniela; Castellucci, Mario; Sanguinetti, Maurizio; D'lppolito, Silvia; Caruso, Alessandro

    2009-02-01

    The adipocytokine resistin impairs glucose tolerance and insulin sensitivity. Here, we examine the effect of resistin on glucose uptake in human trophoblast cells and we demonstrate that transplacental glucose transport is mediated by glucose transporter (GLUT)-1. Furthermore, we evaluate the type of signal transduction induced by resistin in GLUT-1 regulation. BeWo choriocarcinoma cells and primary cytotrophoblast cells were cultured with increasing resistin concentrations for 24 hrs. The main outcome measures include glucose transport assay using [(3)H]-2-deoxy glucose, GLUT-1 protein expression by Western blot analysis and GLUT-1 mRNA detection by quantitative real-time RT-PCR. Quantitative determination of phospho(p)-ERK1/2 in cell lysates was performed by an Enzyme Immunometric Assay and Western blot analysis. Our data demonstrate a direct effect of resistin on normal cytotrophoblastic and on BeWo cells: resistin modulates glucose uptake, GLUT-1 messenger ribonucleic acid (mRNA) and protein expression in placental cells. We suggest that ERK1/2 phosphorylation is involved in the GLUT-1 regulation induced by resistin. In conclusion, resistin causes activation of both the ERK1 and 2 pathway in trophoblast cells. ERK1 and 2 activation stimulated GLUT-1 synthesis and resulted in increase of placental glucose uptake. High resistin levels (50-100 ng/ml) seem able to affect glucose-uptake, presumably by decreasing the cell surface glucose transporter.

  15. Effects of taurine on plasma glucose concentration and active glucose transport in the small intestine.

    PubMed

    Tsuchiya, Yo; Kawamata, Koichi

    2017-11-01

    Taurine lowers blood glucose levels and improves hyperglycemia. However, its effects on glucose transport in the small intestine have not been investigated. Here, we elucidated the effect of taurine on glucose absorption in the small intestine. In the oral glucose tolerance test, addition of 10 mmol/L taurine suppressed the increase in hepatic portal glucose concentrations. To investigate whether the suppressive effect of taurine occurs via down-regulation of active glucose transport in the small intestine, we performed an assay using the everted sac of the rat jejunum. Addition of taurine to the mucosal side of the jejunum suppressed active glucose transport via sodium-glucose cotransporter 1 (SGLT1). After elimination of chloride ions from the mucosal solution, taurine did not show suppressive effects on active glucose transport. These results suggest that taurine suppressed the increase in hepatic portal glucose concentrations via suppression of SGLT1 activity in the rat jejunum, depending on chloride ions. © 2017 Japanese Society of Animal Science.

  16. Optimal glucose management in the perioperative period.

    PubMed

    Evans, Charity H; Lee, Jane; Ruhlman, Melissa K

    2015-04-01

    Hyperglycemia is a common finding in surgical patients during the perioperative period. Factors contributing to poor glycemic control include counterregulatory hormones, hepatic insulin resistance, decreased insulin-stimulated glucose uptake, use of dextrose-containing intravenous fluids, and enteral and parenteral nutrition. Hyperglycemia in the perioperative period is associated with increased morbidity, decreased survival, and increased resource utilization. Optimal glucose management in the perioperative period contributes to reduced morbidity and mortality. To readily identify hyperglycemia, blood glucose monitoring should be instituted for all hospitalized patients. Published by Elsevier Inc.

  17. Average inactivity time model, associated orderings and reliability properties

    NASA Astrophysics Data System (ADS)

    Kayid, M.; Izadkhah, S.; Abouammoh, A. M.

    2018-02-01

    In this paper, we introduce and study a new model called 'average inactivity time model'. This new model is specifically applicable to handle the heterogeneity of the time of the failure of a system in which some inactive items exist. We provide some bounds for the mean average inactivity time of a lifespan unit. In addition, we discuss some dependence structures between the average variable and the mixing variable in the model when original random variable possesses some aging behaviors. Based on the conception of the new model, we introduce and study a new stochastic order. Finally, to illustrate the concept of the model, some interesting reliability problems are reserved.

  18. Correction for spatial averaging in laser speckle contrast analysis

    PubMed Central

    Thompson, Oliver; Andrews, Michael; Hirst, Evan

    2011-01-01

    Practical laser speckle contrast analysis systems face a problem of spatial averaging of speckles, due to the pixel size in the cameras used. Existing practice is to use a system factor in speckle contrast analysis to account for spatial averaging. The linearity of the system factor correction has not previously been confirmed. The problem of spatial averaging is illustrated using computer simulation of time-integrated dynamic speckle, and the linearity of the correction confirmed using both computer simulation and experimental results. The valid linear correction allows various useful compromises in the system design. PMID:21483623

  19. Incoherent averaging of phase singularities in speckle-shearing interferometry.

    PubMed

    Mantel, Klaus; Nercissian, Vanusch; Lindlein, Norbert

    2014-08-01

    Interferometric speckle techniques are plagued by the omnipresence of phase singularities, impairing the phase unwrapping process. To reduce the number of phase singularities by physical means, an incoherent averaging of multiple speckle fields may be applied. It turns out, however, that the results may strongly deviate from the expected √N behavior. Using speckle-shearing interferometry as an example, we investigate the mechanism behind the reduction of phase singularities, both by calculations and by computer simulations. Key to an understanding of the reduction mechanism during incoherent averaging is the representation of the physical averaging process in terms of certain vector fields associated with each speckle field.

  20. Homelessness prevention in New York City: On average, it works

    PubMed Central

    Goodman, Sarena; Messeri, Peter; O'Flaherty, Brendan

    2016-01-01

    This study evaluates the community impact of the first four years of Homebase, a homelessness prevention program in New York City. Family shelter entries decreased on average in the neighborhoods in which Homebase was operating. Homebase effects appear to be heterogeneous, and so different kinds of averages imply different-sized effects. The (geometric) average decrease in shelter entries was about 5% when census tracts are weighted equally, and 11% when community districts (which are much larger) are weighted equally. This study also examines the effect of foreclosures. Foreclosures are associated with more shelter entries in neighborhoods that usually do not send large numbers of families to the shelter system. PMID:26941543

  1. Thomson scattering in the average-atom approximation.

    PubMed

    Johnson, W R; Nilsen, J; Cheng, K T

    2012-09-01

    The average-atom model is applied to study Thomson scattering of x-rays from warm dense matter with emphasis on scattering by bound electrons. Parameters needed to evaluate the dynamic structure function (chemical potential, average ionic charge, free electron density, bound and continuum wave functions, and occupation numbers) are obtained from the average-atom model. The resulting analysis provides a relatively simple diagnostic for use in connection with x-ray scattering measurements. Applications are given to dense hydrogen, beryllium, aluminum, and titanium plasmas. In the case of titanium, bound states are predicted to modify the spectrum significantly.

  2. Average waiting time in FDDI networks with local priorities

    NASA Technical Reports Server (NTRS)

    Gercek, Gokhan

    1994-01-01

    A method is introduced to compute the average queuing delay experienced by different priority group messages in an FDDI node. It is assumed that no FDDI MAC layer priorities are used. Instead, a priority structure is introduced to the messages at a higher protocol layer (e.g. network layer) locally. Such a method was planned to be used in Space Station Freedom FDDI network. Conservation of the average waiting time is used as the key concept in computing average queuing delays. It is shown that local priority assignments are feasable specially when the traffic distribution is asymmetric in the FDDI network.

  3. Lifestyle, glucose regulation and the cognitive effects of glucose load in middle-aged adults.

    PubMed

    Riby, Leigh M; McLaughlin, Jennifer; Riby, Deborah M; Graham, Cheryl

    2008-11-01

    Interventions aimed at improving glucose regulatory mechanisms have been suggested as a possible source of cognitive enhancement in the elderly. In particular, previous research has identified episodic memory as a target for facilitation after either moderate increases in glycaemia (after a glucose drink) or after improvements in glucose regulation. The present study aimed to extend this research by examining the joint effects of glucose ingestion and glucose regulation on cognition. In addition, risk factors associated with the development of poor glucose regulation in middle-aged adults were considered. In a repeated measures design, thirty-three middle-aged adults (aged 35-55 years) performed a battery of memory and non-memory tasks after either 25 g or 50 g glucose or a sweetness matched placebo drink. To assess the impact of individual differences in glucose regulation, blood glucose measurements were taken on four occasions during testing. A lifestyle and diet questionnaire was also administered. Consistent with previous research, episodic memory ability benefited from glucose ingestion when task demands were high. Blood glucose concentration was also found to predict performance across a number of cognitive domains. Interestingly, the risk factors associated with poor glucose regulation were linked to dietary impacts traditionally associated with poor health, e.g. the consumption of high-sugar sweets and drinks. The research replicates earlier work suggesting that task demands are critical to the glucose facilitation effect. Importantly, the data demonstrate clear associations between elevated glycaemia and relatively poor cognitive performance, which may be partly due to the effect of dietary and lifestyle factors.

  4. Single Cell "Glucose Nanosensor" Verifies Elevated Glucose Levels in Individual Cancer Cells.

    PubMed

    Nascimento, Raphael A S; Özel, Rıfat Emrah; Mak, Wai Han; Mulato, Marcelo; Singaram, Bakthan; Pourmand, Nader

    2016-02-10

    Because the transition from oxidative phosphorylation to anaerobic glycolytic metabolism is a hallmark of cancer progression, approaches to identify single living cancer cells by their unique glucose metabolic signature would be useful. Here, we present nanopipettes specifically developed to measure glucose levels in single cells with temporal and spatial resolution, and we use this technology to verify the hypothesis that individual cancer cells can indeed display higher intracellular glucose levels. The nanopipettes were functionalized as glucose nanosensors by immobilizing glucose oxidase (GOx) covalently to the tip so that the interaction of glucose with GOx resulted in a catalytic oxidation of β-d-glucose to d-gluconic acid, which was measured as a change in impedance due to drop in pH of the medium at the nanopipette tip. Calibration studies showed a direct relationship between impedance changes at the tip and glucose concentration in solution. The glucose nanosensor quantified single cell intracellular glucose levels in human fibroblasts and the metastatic breast cancer lines MDA-MB-231 and MCF7 and revealed that the cancer cells expressed reproducible and reliable increases in glucose levels compared to the nonmalignant cells. Nanopipettes allow repeated sampling of the same cell, as cells remain viable during and after measurements. Therefore, nanopipette-based glucose sensors provide an approach to compare changes in glucose levels with changes in proliferative or metastatic state. The platform has great promise for mechanistic investigations, as a diagnostic tool to distinguish cancer cells from nonmalignant cells in heterogeneous tissue biopsies, as well as a tool for monitoring cancer progression in situ.

  5. Myo-inositol inhibits intestinal glucose absorption and promotes muscle glucose uptake: a dual approach study.

    PubMed

    Chukwuma, Chika Ifeanyi; Ibrahim, Mohammed Auwal; Islam, Md Shahidul

    2016-12-01

    The present study investigated the effects of myo-inositol on muscle glucose uptake and intestinal glucose absorption ex vivo as well as in normal and type 2 diabetes model of rats. In ex vivo study, both intestinal glucose absorption and muscle glucose uptake were studied in isolated rat jejunum and psoas muscle respectively in the presence of increasing concentrations (2.5 % to 20 %) of myo-inositol. In the in vivo study, the effect of a single bolus dose (1 g/kg bw) of oral myo-inositol on intestinal glucose absorption, blood glucose, gastric emptying and digesta transit was investigated in normal and type 2 diabetic rats after 1 h of co-administration with 2 g/kg bw glucose, when phenol red was used as a recovery marker. Myo-inositol inhibited intestinal glucose absorption (IC 50  = 28.23 ± 6.01 %) and increased muscle glucose uptake, with (GU 50  = 2.68 ± 0.75 %) or without (GU 50  = 8.61 ± 0.55 %) insulin. Additionally, oral myo-inositol not only inhibited duodenal glucose absorption and reduced blood glucose increase, but also delayed gastric emptying and accelerated digesta transit in both normal and diabetic animals. Results of this study suggest that dietary myo-inositol inhibits intestinal glucose absorption both in ex vivo and in normal or diabetic rats and also promotes muscle glucose uptake in ex vivo condition. Hence, myo-inositol may be further investigated as a possible anti-hyperglycaemic dietary supplement for diabetic foods and food products.

  6. Improved post-prandial ghrelin response by nateglinide or acarbose therapy contributes to glucose stability in Type 2 diabetic patients.

    PubMed

    Zheng, F; Yin, X; Lu, W; Zhou, J; Yuan, H; Li, H

    2013-01-01

    Recent studies highlight an important role of ghrelin in glucose homeostasis, while the association between ghrelin regulation and glucose fluctuation is unclear. We compared the effects of two postprandial hypoglycemic agents on ghrelin response and determined the contribution of ghrelin response to glucose stability in Type 2 diabetic (T2DM) patients. Forty newly- diagnosed T2DM patients were randomly allocated to receive nateglinide or acarbose for 4 weeks, with twenty body mass index (BMI)-matched normoglycemic subjects as controls. Mean glucose values and daily average glucose excursion were assessed using continuous glucose monitoring system. Serum ghrelin levels were determined by enzyme-linked immunosorbent assay. T2DM patients had similar fasting ghrelin levels (p=0.546), while their postprandial ghrelin suppressions at 30 min and 120 min were reduced as compared to BMI-matched normoglycemic controls (p<0.01). Both nateglinide and acarbose increased post-prandial ghrelin suppression at 120 min and reduced ghrelin area under the curve (AUCGHRL) (p<0.05), while only nateglinide increased postprandial ghrelin suppression at 30 min (p<0.01), which was positively correlated with the increased early-phase insulin secretion by 4 weeks of nateglinide therapy (r=0.48, p=0.05). The decrease in AUCGHRL was positively correlated with the decrease in daily average glucose excursion and mean glucose values either by 4 weeks of nateglinide or acarbose therapy (p<0.05). Both nateglinide and acarbose increase post-prandial ghrelin suppression. Improved ghrelin regulation is most likely to play a role in glucose stability in T2DM patients with nateglinide or acarbose therapy.

  7. GIS Tools to Estimate Average Annual Daily Traffic

    DOT National Transportation Integrated Search

    2012-06-01

    This project presents five tools that were created for a geographical information system to estimate Annual Average Daily : Traffic using linear regression. Three of the tools can be used to prepare spatial data for linear regression. One tool can be...

  8. Effects of spatial variability and scale on areal -average evapotranspiration

    NASA Technical Reports Server (NTRS)

    Famiglietti, J. S.; Wood, Eric F.

    1993-01-01

    This paper explores the effect of spatial variability and scale on areally-averaged evapotranspiration. A spatially-distributed water and energy balance model is employed to determine the effect of explicit patterns of model parameters and atmospheric forcing on modeled areally-averaged evapotranspiration over a range of increasing spatial scales. The analysis is performed from the local scale to the catchment scale. The study area is King's Creek catchment, an 11.7 sq km watershed located on the native tallgrass prairie of Kansas. The dominant controls on the scaling behavior of catchment-average evapotranspiration are investigated by simulation, as is the existence of a threshold scale for evapotranspiration modeling, with implications for explicit versus statistical representation of important process controls. It appears that some of our findings are fairly general, and will therefore provide a framework for understanding the scaling behavior of areally-averaged evapotranspiration at the catchment and larger scales.

  9. Robust averaging protects decisions from noise in neural computations

    PubMed Central

    Herce Castañón, Santiago; Solomon, Joshua A.; Vandormael, Hildward

    2017-01-01

    An ideal observer will give equivalent weight to sources of information that are equally reliable. However, when averaging visual information, human observers tend to downweight or discount features that are relatively outlying or deviant (‘robust averaging’). Why humans adopt an integration policy that discards important decision information remains unknown. Here, observers were asked to judge the average tilt in a circular array of high-contrast gratings, relative to an orientation boundary defined by a central reference grating. Observers showed robust averaging of orientation, but the extent to which they did so was a positive predictor of their overall performance. Using computational simulations, we show that although robust averaging is suboptimal for a perfect integrator, it paradoxically enhances performance in the presence of “late” noise, i.e. which corrupts decisions during integration. In other words, robust decision strategies increase the brain’s resilience to noise arising in neural computations during decision-making. PMID:28841644

  10. The origin of consistent protein structure refinement from structural averaging.

    PubMed

    Park, Hahnbeom; DiMaio, Frank; Baker, David

    2015-06-02

    Recent studies have shown that explicit solvent molecular dynamics (MD) simulation followed by structural averaging can consistently improve protein structure models. We find that improvement upon averaging is not limited to explicit water MD simulation, as consistent improvements are also observed for more efficient implicit solvent MD or Monte Carlo minimization simulations. To determine the origin of these improvements, we examine the changes in model accuracy brought about by averaging at the individual residue level. We find that the improvement in model quality from averaging results from the superposition of two effects: a dampening of deviations from the correct structure in the least well modeled regions, and a reinforcement of consistent movements towards the correct structure in better modeled regions. These observations are consistent with an energy landscape model in which the magnitude of the energy gradient toward the native structure decreases with increasing distance from the native state. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Development and evaluation of a hybrid averaged orbit generator

    NASA Technical Reports Server (NTRS)

    Mcclain, W. D.; Long, A. C.; Early, L. W.

    1978-01-01

    A rapid orbit generator based on a first-order application of the Generalized Method of Averaging has been developed for the Research and Development (R&D) version of the Goddard Trajectory Determination System (GTDS). The evaluation of the averaged equations of motion can use both numerically averaged and recursively evaluated, analytically averaged perturbation models. These equations are numerically integrated to obtain the secular and long-period motion. Factors affecting efficient orbit prediction are discussed and guidelines are presented for treatment of each major perturbation. Guidelines for obtaining initial mean elements compatible with the theory are presented. An overview of the orbit generator is presented and comparisons with high precision methods are given.

  12. Time averaging, ageing and delay analysis of financial time series

    NASA Astrophysics Data System (ADS)

    Cherstvy, Andrey G.; Vinod, Deepak; Aghion, Erez; Chechkin, Aleksei V.; Metzler, Ralf

    2017-06-01

    We introduce three strategies for the analysis of financial time series based on time averaged observables. These comprise the time averaged mean squared displacement (MSD) as well as the ageing and delay time methods for varying fractions of the financial time series. We explore these concepts via statistical analysis of historic time series for several Dow Jones Industrial indices for the period from the 1960s to 2015. Remarkably, we discover a simple universal law for the delay time averaged MSD. The observed features of the financial time series dynamics agree well with our analytical results for the time averaged measurables for geometric Brownian motion, underlying the famed Black-Scholes-Merton model. The concepts we promote here are shown to be useful for financial data analysis and enable one to unveil new universal features of stock market dynamics.

  13. 40 CFR 1033.710 - Averaging emission credits.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    .... You may average emission credits only as allowed by § 1033.740. (b) You may certify one or more engine... all emission-credit transactions in that model year is greater than or equal to zero. (c) If you...

  14. Estimation of average daily traffic on local roads in Kentucky.

    DOT National Transportation Integrated Search

    2016-07-01

    Kentucky Transportation Cabinet (KYTC) officials use annual average daily traffic (AADT) to estimate intersection : performance across the state maintained highway system. KYTC currently collects AADTs for state maintained : roads but frequently lack...

  15. Determining the Average Age of School Plant Building Space.

    ERIC Educational Resources Information Center

    Uerling, Donald F.

    1984-01-01

    Presents a method for calculating the age of the space in a specific building inventory, and suggests some practical applications. A fourfold procedure is provided for finding the average age of total building space. (TE)

  16. The random coding bound is tight for the average code.

    NASA Technical Reports Server (NTRS)

    Gallager, R. G.

    1973-01-01

    The random coding bound of information theory provides a well-known upper bound to the probability of decoding error for the best code of a given rate and block length. The bound is constructed by upperbounding the average error probability over an ensemble of codes. The bound is known to give the correct exponential dependence of error probability on block length for transmission rates above the critical rate, but it gives an incorrect exponential dependence at rates below a second lower critical rate. Here we derive an asymptotic expression for the average error probability over the ensemble of codes used in the random coding bound. The result shows that the weakness of the random coding bound at rates below the second critical rate is due not to upperbounding the ensemble average, but rather to the fact that the best codes are much better than the average at low rates.

  17. Average geodesic distance of skeleton networks of Sierpinski tetrahedron

    NASA Astrophysics Data System (ADS)

    Yang, Jinjin; Wang, Songjing; Xi, Lifeng; Ye, Yongchao

    2018-04-01

    The average distance is concerned in the research of complex networks and is related to Wiener sum which is a topological invariant in chemical graph theory. In this paper, we study the skeleton networks of the Sierpinski tetrahedron, an important self-similar fractal, and obtain their asymptotic formula for average distances. To provide the formula, we develop some technique named finite patterns of integral of geodesic distance on self-similar measure for the Sierpinski tetrahedron.

  18. Averaging Bias Correction for Future IPDA Lidar Mission MERLIN

    NASA Astrophysics Data System (ADS)

    Tellier, Yoann; Pierangelo, Clémence; Wirth, Martin; Gibert, Fabien

    2018-04-01

    The CNES/DLR MERLIN satellite mission aims at measuring methane dry-air mixing ratio column (XCH4) and thus improving surface flux estimates. In order to get a 1% precision on XCH4 measurements, MERLIN signal processing assumes an averaging of data over 50 km. The induced biases due to the non-linear IPDA lidar equation are not compliant with accuracy requirements. This paper analyzes averaging biases issues and suggests correction algorithms tested on realistic simulated scenes.

  19. Evidence for brain glucose dysregulation in Alzheimer's disease.

    PubMed

    An, Yang; Varma, Vijay R; Varma, Sudhir; Casanova, Ramon; Dammer, Eric; Pletnikova, Olga; Chia, Chee W; Egan, Josephine M; Ferrucci, Luigi; Troncoso, Juan; Levey, Allan I; Lah, James; Seyfried, Nicholas T; Legido-Quigley, Cristina; O'Brien, Richard; Thambisetty, Madhav

    2018-03-01

    It is unclear whether abnormalities in brain glucose homeostasis are associated with Alzheimer's disease (AD) pathogenesis. Within the autopsy cohort of the Baltimore Longitudinal Study of Aging, we measured brain glucose concentration and assessed the ratios of the glycolytic amino acids, serine, glycine, and alanine to glucose. We also quantified protein levels of the neuronal (GLUT3) and astrocytic (GLUT1) glucose transporters. Finally, we assessed the relationships between plasma glucose measured before death and brain tissue glucose. Higher brain tissue glucose concentration, reduced glycolytic flux, and lower GLUT3 are related to severity of AD pathology and the expression of AD symptoms. Longitudinal increases in fasting plasma glucose levels are associated with higher brain tissue glucose concentrations. Impaired glucose metabolism due to reduced glycolytic flux may be intrinsic to AD pathogenesis. Abnormalities in brain glucose homeostasis may begin several years before the onset of clinical symptoms. Copyright © 2017 the Alzheimer's Association. All rights reserved.

  20. Scalable Robust Principal Component Analysis Using Grassmann Averages.

    PubMed

    Hauberg, Sren; Feragen, Aasa; Enficiaud, Raffi; Black, Michael J

    2016-11-01

    In large datasets, manual data verification is impossible, and we must expect the number of outliers to increase with data size. While principal component analysis (PCA) can reduce data size, and scalable solutions exist, it is well-known that outliers can arbitrarily corrupt the results. Unfortunately, state-of-the-art approaches for robust PCA are not scalable. We note that in a zero-mean dataset, each observation spans a one-dimensional subspace, giving a point on the Grassmann manifold. We show that the average subspace corresponds to the leading principal component for Gaussian data. We provide a simple algorithm for computing this Grassmann Average ( GA), and show that the subspace estimate is less sensitive to outliers than PCA for general distributions. Because averages can be efficiently computed, we immediately gain scalability. We exploit robust averaging to formulate the Robust Grassmann Average (RGA) as a form of robust PCA. The resulting Trimmed Grassmann Average ( TGA) is appropriate for computer vision because it is robust to pixel outliers. The algorithm has linear computational complexity and minimal memory requirements. We demonstrate TGA for background modeling, video restoration, and shadow removal. We show scalability by performing robust PCA on the entire Star Wars IV movie; a task beyond any current method. Source code is available online.

  1. Spatial averaging for small molecule diffusion in condensed phase environments

    NASA Astrophysics Data System (ADS)

    Plattner, Nuria; Doll, J. D.; Meuwly, Markus

    2010-07-01

    Spatial averaging is a new approach for sampling rare-event problems. The approach modifies the importance function which improves the sampling efficiency while keeping a defined relation to the original statistical distribution. In this work, spatial averaging is applied to multidimensional systems for typical problems arising in physical chemistry. They include (I) a CO molecule diffusing on an amorphous ice surface, (II) a hydrogen molecule probing favorable positions in amorphous ice, and (III) CO migration in myoglobin. The systems encompass a wide range of energy barriers and for all of them spatial averaging is found to outperform conventional Metropolis Monte Carlo. It is also found that optimal simulation parameters are surprisingly similar for the different systems studied, in particular, the radius of the point cloud over which the potential energy function is averaged. For H2 diffusing in amorphous ice it is found that facile migration is possible which is in agreement with previous suggestions from experiment. The free energy barriers involved are typically lower than 1 kcal/mol. Spatial averaging simulations for CO in myoglobin are able to locate all currently characterized metastable states. Overall, it is found that spatial averaging considerably improves the sampling of configurational space.

  2. Designing a highly active soluble PQQ-glucose dehydrogenase for efficient glucose biosensors and biofuel cells

    SciTech Connect

    Durand, Fabien; Stines-Chaumeil, Claire; Flexer, Victoria

    2010-11-26

    Research highlights: {yields} A new mutant of PQQ-GDH designed for glucose biosensors application. {yields} First mutant of PQQ-GDH with higher activity for D-glucose than the Wild type. {yields} Position N428 is a key point to increase the enzyme activity. {yields} Molecular modeling shows that the N428 C mutant displays a better interaction for PQQ than the WT. -- Abstract: We report for the first time a soluble PQQ-glucose dehydrogenase that is twice more active than the wild type for glucose oxidation and was obtained by combining site directed mutagenesis, modelling and steady-state kinetics. The observed enhancement is attributed to amore » better interaction between the cofactor and the enzyme leading to a better electron transfer. Electrochemical experiments also demonstrate the superiority of the new mutant for glucose oxidation and make it a promising enzyme for the development of high-performance glucose biosensors and biofuel cells.« less

  3. [Artificial pancreas for automated glucose control].

    PubMed

    Blauw, Helga; van Bon, Arianne C; de Vries, J H Hans

    2013-01-01

    Strict glucose control is important for patients with diabetes mellitus in order to prevent complications. However, many patients find it difficult to achieve the recommended HbA1c level. The possibility of hypoglycaemia plays an important role in this. The artificial pancreas automates glucose control, improving glucose levels without increasing hypoglycaemic events. The required insulin dose is calculated and administered on the basis of continuous glucose measurements, taking over a large part of the treatment from the patient. Several research groups are working on making this technique suitable for home use. It is expected that the artificial pancreas will become available in the near future. However, effectiveness and safety will have to be investigated in long-term studies. A large number of insulin-dependent patients with diabetes could be eligible for this treatment.

  4. A glucose-centric perspective of hyperglycemia.

    PubMed

    Ramasarma, T; Rafi, M

    2016-02-01

    Digestion of food in the intestines converts the compacted storage carbohydrates, starch and glycogen, to glucose. After each meal, a flux of glucose (> 200 g) passes through the blood pool (4-6 g) in a short period of 2 h, keeping its concentration ideally in the range of 80-120 mg/100 mL. Tissue-specific glucose transporters (GLUTs) aid in the distribution of glucose to all tissues. The balance glucose after meeting the immediate energy needs is converted into glycogen and stored in liver (up to 100 g) and skeletal muscle (up to 300 g) for later use. High blood glucose gives the signal for increased release of insulin from pancreas. Insulin binds to insulin receptor on the plasma membrane and activates its autophosphorylation. This initiates the post-insulin-receptor signal cascade that accelerates synthesis of glycogen and triglyceride. Parallel control by phos-dephos and redox regulation of proteins exists for some of these steps. A major action of insulin is to inhibit gluconeogensis in the liver decreasing glucose output into blood. Cases with failed control of blood glucose have alarmingly increased since 1960 coinciding with changed life-styles and large scale food processing. Many of these turned out to be resistant to insulin, usually accompanied by dysfunctional glycogen storage. Glucose has an extended stay in blood at 8 mM and above and then indiscriminately adds on to surface protein-amino groups. Fructose in common sugar is 10-fold more active. This random glycation process interferes with the functions of many proteins (e.g., hemoglobin, eye lens proteins) and causes progressive damage to heart, kidneys, eyes and nerves. Some compounds are known to act as insulin mimics. Vanadium-peroxide complexes act at post-receptor level but are toxic. The fungus-derived 2,5-dihydroxybenzoquinone derivative is the first one known to act on the insulin receptor. The safe herbal products in use for centuries for glucose control have multiple active principles and

  5. Is Low Blood Glucose (Hypoglycemia) Dangerous?

    MedlinePlus

    ... for brain damage related to repeated severe hypoglycemia. Guidelines for managing hypoglycemia Recognize symptoms (physical, emotional, mental) ... not risen above the target levels defined above . Guidelines for safe driving Check blood glucose levels before ...

  6. [Thromboresistance of glucose-containing hydrogels].

    PubMed

    Valuev, I L; Valuev, L I; Vanchugova, L V; Obydennova, I V; Valueva, T A

    2013-01-01

    The thromboresistance of glucose-sensitive polymer hydrogels, modeling one of the functions of the pancreas, namely, the ability to secrete insulin in response to the introduction of glucose into the environment, has been studied. Hydrogels were synthesized by the copolymerization of hydroxyethyl methacrylate with N-acryloyl glucosamine in the presence of a cross-linking agent and subsequently treated with concanavalin A. Introduction of glucose residues into the hydrogel did not result in significant changes in either the number of trombocytes adhered to the hydrogel or the degree of denaturation of blood plasma proteins interacting with the hydrogel. Consequently, the biological activity of insulin did not change after release from the hydrogel. The use of glucose-sensitive hydrogels is supposed to contribute to the development of a novel strategy for the treatment of diabetes.

  7. Enhancement of D-lactic acid production from a mixed glucose and xylose substrate by the Escherichia coli strain JH15 devoid of the glucose effect.

    PubMed

    Lu, Hongying; Zhao, Xiao; Wang, Yongze; Ding, Xiaoren; Wang, Jinhua; Garza, Erin; Manow, Ryan; Iverson, Andrew; Zhou, Shengde

    2016-02-19

    A thermal tolerant stereo-complex poly-lactic acid (SC-PLA) can be made by mixing Poly-D-lactic acid (PDLA) and poly-L-lactic acid (PLLA) at a defined ratio. This environmentally friendly biodegradable polymer could replace traditional recalcitrant petroleum-based plastics. To achieve this goal, however, it is imperative to produce optically pure lactic acid isomers using a cost-effective substrate such as cellulosic biomass. The roadblock of this process is that: 1) xylose derived from cellulosic biomass is un-fermentable by most lactic acid bacteria; 2) the glucose effect results in delayed and incomplete xylose fermentation. An alternative strain devoid of the glucose effect is needed to co-utilize both glucose and xylose for improved D-lactic acid production using a cellulosic biomass substrate. A previously engineered L-lactic acid Escherichia coli strain, WL204 (ΔfrdBC ΔldhA ΔackA ΔpflB ΔpdhR ::pflBp6-acEF-lpd ΔmgsA ΔadhE, ΔldhA::ldhL), was reengineered for production of D-lactic acid, by replacing the recombinant L-lactate dehydrogenase gene (ldhL) with a D-lactate dehydrogenase gene (ldhA). The glucose effect (catabolite repression) of the resulting strain, JH13, was eliminated by deletion of the ptsG gene which encodes for IIBC(glc) (a PTS enzyme for glucose transport). The derived strain, JH14, was metabolically evolved through serial transfers in screw-cap tubes containing glucose. The evolved strain, JH15, regained improved anaerobic cell growth using glucose. In fermentations using a mixture of glucose (50 g L(-1)) and xylose (50 g L(-1)), JH15 co-utilized both glucose and xylose, achieving an average sugar consumption rate of 1.04 g L(-1)h(-1), a D-lactic acid titer of 83 g L(-1), and a productivity of 0.86 g L(-1) h(-1). This result represents a 46 % improved sugar consumption rate, a 26 % increased D-lactic acid titer, and a 48 % enhanced productivity, compared to that achieved by JH13. These results demonstrated that JH15 has

  8. Role of the glucose-sensing receptor in insulin secretion.

    PubMed

    Kojima, Itaru; Medina, Johan; Nakagawa, Yuko

    2017-09-01

    Glucose is a primary stimulator of insulin secretion. It has been thought that glucose exerts its effect by a mechanism solely dependent on glucose metabolism. We show here that glucose induces rapid Ca 2+ and cyclic AMP signals in β-cells. These rapid signals are independent of glucose-metabolism and are reproduced by non-metabolizable glucose analogues. These results led us to postulate that glucose activates a cell-surface receptor, namely the glucose-sensing receptor. Rapid signals induced by glucose are blocked by inhibition of a sweet taste receptor subunit T1R3 and a calcium-sensing receptor subunit CaSR. In accordance with these observations, T1R3 and CaSR form a heterodimer. In addition, a heterodimer of T1R3 and CaSR is activated by glucose. These results suggest that a heterodimer of T1R3 and CaSR is a major component of the glucose-sensing receptor. When the glucose-sensing receptor is blocked, glucose-induced insulin secretion is inhibited. Also, ATP production is significantly attenuated by the inhibition of the receptor. Conversely, stimulation of the glucose-sensing receptor by either artificial sweeteners or non-metabolizable glucose analogue increases ATP. Hence, the glucose-sensing receptor signals promote glucose metabolism. Collectively, glucose activates the cell-surface glucose-sensing receptor and promotes its own metabolism. Glucose then enters the cells and is metabolized through already activated metabolic pathways. The glucose-sensing receptor is a key molecule regulating the action of glucose in β-cells. © 2017 John Wiley & Sons Ltd.

  9. Acid hydrolysis of cellulose to yield glucose

    DOEpatents

    Tsao, George T.; Ladisch, Michael R.; Bose, Arindam

    1979-01-01

    A process to yield glucose from cellulose through acid hydrolysis. Cellulose is recovered from cellulosic materials, preferably by pretreating the cellulosic materials by dissolving the cellulosic materials in Cadoxen or a chelating metal caustic swelling solvent and then precipitating the cellulose therefrom. Hydrolysis is accomplished using an acid, preferably dilute sulfuric acid, and the glucose is yielded substantially without side products. Lignin may be removed either before or after hydrolysis.

  10. Diabetic glucose meter for the determination of glucose in microbial cultures.

    PubMed

    Flavigny, Raphael

    2014-05-01

    In wastewater, biological phosphate removal can fail because of the presence of glycogen accumulating organism (GAO), therefore measuring glycogen stored in microbial cultures provides information on the bacterial population type. Once glycogen is hydrolysed to glucose it was accurately measured using a human glucose meter. The standard curves demonstrate linearity regardless of the pre-treatment of the glucose solution at neutral pH. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Corticosterone and exogenous glucose alter blood glucose levels, neurotoxicity, and vascular toxicity produced by methamphetamine.

    PubMed

    Bowyer, John F; Tranter, Karen M; Sarkar, Sumit; George, Nysia I; Hanig, Joseph P; Kelly, Kimberly A; Michalovicz, Lindsay T; Miller, Diane B; O'Callaghan, James P

    2017-10-01

    Our previous studies have raised the possibility that altered blood glucose levels may influence and/or be predictive of methamphetamine (METH) neurotoxicity. This study evaluated the effects of exogenous glucose and corticosterone (CORT) pretreatment alone or in combination with METH on blood glucose levels and the neural and vascular toxicity produced. METH exposure consisted of four sequential injections of 5, 7.5, 10, and 10 mg/kg (2 h between injections) D-METH. The three groups given METH in combination with saline, glucose (METH+Glucose), or CORT (METH+CORT) had significantly higher glucose levels compared to the corresponding treatment groups without METH except at 3 h after the last injection. At this last time point, the METH and METH+Glucose groups had lower levels than the non-METH groups, while the METH+CORT group did not. CORT alone or glucose alone did not significantly increase blood glucose. Mortality rates for the METH+CORT (40%) and METH+Glucose (44%) groups were substantially higher than the METH (< 10%) group. Additionally, METH+CORT significantly increased neurodegeneration above the other three METH treatment groups (≈ 2.5-fold in the parietal cortex). Thus, maintaining elevated levels of glucose during METH exposure increases lethality and may exacerbate neurodegeneration. Neuroinflammation, specifically microglial activation, was associated with degenerating neurons in the parietal cortex and thalamus after METH exposure. The activated microglia in the parietal cortex were surrounding vasculature in most cases and the extent of microglial activation was exacerbated by CORT pretreatment. Our findings show that acute CORT exposure and elevated blood glucose levels can exacerbate METH-induced vascular damage, neuroinflammation, neurodegeneration and lethality. Cover Image for this issue: doi. 10.1111/jnc.13819. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

  12. Improving the Glucose Meter Error Grid With the Taguchi Loss Function.

    PubMed

    Krouwer, Jan S

    2016-07-01

    Glucose meters often have similar performance when compared by error grid analysis. This is one reason that other statistics such as mean absolute relative deviation (MARD) are used to further differentiate performance. The problem with MARD is that too much information is lost. But additional information is available within the A zone of an error grid by using the Taguchi loss function. Applying the Taguchi loss function gives each glucose meter difference from reference a value ranging from 0 (no error) to 1 (error reaches the A zone limit). Values are averaged over all data which provides an indication of risk of an incorrect medical decision. This allows one to differentiate glucose meter performance for the common case where meters have a high percentage of values in the A zone and no values beyond the B zone. Examples are provided using simulated data. © 2015 Diabetes Technology Society.

  13. Oxyntomodulin stimulates intestinal glucose uptake in rats.

    PubMed

    Collie, N L; Zhu, Z; Jordan, S; Reeve, J R

    1997-06-01

    Enteroglucagon peptides have long been proposed as mediators of intestinal adaptation, including mucosal growth and nutrient absorptive capacity. The hypothesis that infusions of oxyntomodulin, a bioactive form of enteroglucagon, would stimulate glucose and amino acid uptake was tested and its effects were compared with those of glucagon. Rats were infused intravenously via minipumps with either saline, rat oxyntomodulin (0.47 nmol x kg(-1) x h[-1]), or glucagon (0.88 nmol x kg(-1) x h[-1]) for 7 days, and plasma hormone levels were measured. At death, intestinal dimensions and brush border uptake of D-glucose and L-proline were measured using an in vitro everted sleeve technique. Plasma enteroglucagon and glucagon levels were increased 4- and 12-fold, respectively, but there were no effects on food intake, body weight, or intestinal dimensions. In contrast, oxyntomodulin and glucagon significantly stimulated total intestinal glucose uptake capacity by 44% and 53%, respectively, over controls. Oxyntomodulin most potently enhanced glucose uptake in the ileum (215%), whereas glucagon's greatest effect was in the jejunum (63%-85%). However, neither peptide affected proline uptake. These results support a new, specific action for oxyntomodulin in intestinal adaptation as a glucose uptake stimulator and confirm glucagon's role as a regulator of glucose uptake.

  14. Glucose determination with fiber optic spectrometers

    NASA Astrophysics Data System (ADS)

    Starke, Eva; Kemper, Ulf; Barschdorff, Dieter

    1999-05-01

    Noninvasive blood glucose monitoring is the aim of research activities concerning the detection of small glucose concentrations dissolved in water and blood plasma. One approach for these measurements is the exploitation of absorption bands in the near infrared. However, the strong absorption of water represents a major difficulty. Transmission measurements of glucose dissolved in water and in blood plasma in the spectral region around 1600 nm with one- beam spectrometers and a FT-IR spectrometer are discussed. The evaluation of the data is carried out using a two-layer Lambert-Beer model and neural networks. In order to reduce the dimensions of a potential measuring device, an integrated acousto-optic tunable filter (AOTF) with an Erbium doped fiber amplifier as a radiation source is used. The fiber optic components are examined concerning their suitability. The smallest concentrations of glucose dissolved in water that can be separated are approximately 50 mg/dl. In the range of 50 mg/dl to 1000 mg/dl a correlation coefficient of 0.98 between real and estimated glucose concentrations is achieved using neural networks. In blood plasma so far glucose concentrations of about 100 mg/dl can be distinguished with good accuracy.

  15. Noninvasive Continuous Monitoring of Tear Glucose Using Glucose-Sensing Contact Lenses.

    PubMed

    Ascaso, Francisco J; Huerva, Valentín

    2016-04-01

    : The incidence of diabetes mellitus is dramatically increasing in the developed countries. Tight control of blood glucose concentration is crucial to diabetic patients to prevent microvascular complications. Self-monitoring of blood glucose is widely used for controlling blood glucose levels and usually performed by an invasive test using a portable glucometer. Many technologies have been developed over the past decades with the purpose of obtaining a continuous physiological glycemic monitoring. A contact lens is the ideal vehicle for continuous tear glucose monitoring of glucose concentration in tear film. There are several research groups that are working in the development of contact lenses with embedded biosensors for continuously and noninvasively monitoring tear glucose levels. Although numerous aspects must be improved, contact lens technology is one step closer to helping diabetic subjects better manage their condition, and these contact lenses will be able to measure the level of glucose in the wearer's tears and communicate the information to a mobile phone or computer. This article reviews studies on ocular glucose and its monitoring methods as well as the attempts to continuously monitor the concentration of tear glucose by using contact lens-based sensors.

  16. Glucose as substrate and signal in priming: Results from experiments with non-metabolizable glucose analogues

    NASA Astrophysics Data System (ADS)

    Mason-Jones, Kyle; Kuzyakov, Yakov

    2016-04-01

    Priming of soil organic matter remains the subject of intense research, but a mechanistic explanation of the phenomenon remains to be demonstrated. This is largely due to the multiple effects of easily available carbon on the soil microbial community, and the challenge of separating these influences from one another. Several glucose analogues can be taken up by microbial glucose transporters and have similar regulatory effects on metabolism. These substances are, however, not easily catabolized by the common glycolytic pathway, limiting their energy value. Therefore, they can be used to distinguish between the action of glucose as a metabolic signal, and its influence as an energy source. We incubated an agricultural Haplic Luvisol under controlled conditions for 24 days after addition of: 1) glucose, 2) 3-O-methyl-glucose, 3) α-methylglucoside or 4) 2-deoxyglucose, at three concentration levels, along with a control treatment of water addition. CO2 efflux from soil was monitored by trapping evolved CO2 in NaOH and back-titration with HCl. On the first day after amendment, CO2 efflux from soil increased strongly for glucose and much less for the analogues, relative to the control. Only glucose caused a peak in efflux within the first two days. Peak mineralization of 2-deoxyglucose and α-methylglucoside was delayed until the third day, while CO2 from 3-O-methyl-glucose increased gradually, with a peak delayed by approximately a week. For glucose, the immediate increase in respiration was strongly dependent on the amount of glucose added, but this was not the case for the analogues, indicating that the catabolic potential for these substances was saturated. This is consistent with only a small part of the microbial community being capable of utilizing these carbon sources. In a subsequent experiment, 14C-labelled glucose or 14C-labelled 3-O-methyl-glucose were added to the same soil, enabling quantification of the priming effect. For 3-O-methyl-glucose, priming was

  17. Design of Cyclic Peptide Based Glucose Receptors and Their Application in Glucose Sensing.

    PubMed

    Li, Chao; Chen, Xin; Zhang, Fuyuan; He, Xingxing; Fang, Guozhen; Liu, Jifeng; Wang, Shuo

    2017-10-03

    Glucose assay is of great scientific significance in clinical diagnostics and bioprocess monitoring, and to design a new glucose receptor is necessary for the development of more sensitive, selective, and robust glucose detection techniques. Herein, a series of cyclic peptide (CP) glucose receptors were designed to mimic the binding sites of glucose binding protein (GBP), and CPs' sequence contained amino acid sites Asp, Asn, His, Asp, and Arg, which constituted the first layer interactions of GBP. The properties of these CPs used as a glucose receptor or substitute for the GBP were studied by using a quartz crystal microbalance (QCM) technique. It was found that CPs can form a self-assembled monolayer at the Au quartz electrode surface, and the monolayer's properties were characterized by using cyclic voltammetry, electrochemical impedance spectroscopy, and atomic force microscopy. The CPs' binding affinity to saccharide (i.e., galactose, fructose, lactose, sucrose, and maltose) was investigated, and the CPs' sensitivity and selectivity toward glucose were found to be dependent upon the configuration,i.e., the amino acids sequence of the CPs. The cyclic unit with a cyclo[-CNDNHCRDNDC-] sequence gave the highest selectivity and sensitivity for glucose sensing. This work suggests that a synthetic peptide bearing a particular functional sequence could be applied for developing a new generation of glucose receptors and would find huge application in biological, life science, and clinical diagnostics fields.

  18. A model of the endogenous glucose balance incorporating the characteristics of glucose transporters.

    PubMed

    Arleth, T; Andreassen, S; Federici, M O; Benedetti, M M

    2000-07-01

    This paper describes the development and preliminary test of a model of the endogenous glucose balance that incorporates the characteristics of the glucose transporters GLUT1, GLUT3 and GLUT4. In the modeling process the model is parameterized with nine parameters that are subsequently estimated from data in the literature on the hepatic- and endogenous- balances at various combinations of blood glucose and insulin levels. The ability of the resulting endogenous balance to fit blood glucose measured from patients was tested on 20 patients. The fit obtained with this model compared favorably with the fit obtained with the endogenous balance currently incorporated in the DIAS system.

  19. Dual-test monitoring of hyperglycemia using daily glucose and weekly fructosamine values.

    PubMed

    Carter, A W; Borchardt, N; Cooney, M; Greene, D

    2001-01-01

    The purpose of this study was to assess the impact of using a dual-test blood glucose/fructosamine home monitoring system to assist individuals identified as having the potential for poor glycemic control to achieve values closer to normal. Forty-eight subjects found to have a fasting blood glucose value of > or = 126 mg/dL, casual blood glucose value of > or = 140 mg/dL, and/or blood fructosamine value of > or = 310 micromol/L, agreed to perform daily self testing for 90 days and were provided a dual-test blood glucose/fructosamine home monitoring system and testing supplies at no charge to them. Medication changes/compliance along with dietary and exercise habits were compared to testing results by the principle investigator at approximate 30-day intervals. The desired goal of this project was to achieve and/or maintain a fasting blood glucose value of < or = 110 mg/dL, a casual blood glucose value of < or = 140 mg/dL and a blood fructosamine value of < or = 310 micromol/L by encouraging each individual to realize the effect of dietary intake and exercise habits, and understand the importance of medication compliance, if appropriate, in achieving better overall glycemic control. Four subjects withdrew from the study prior to completion, 11 of the remaining 44 completed 60 days of testing and 33 of 44 completed 90 days of testing. Regular monitoring and counseling achieved an average reduction in blood glucose of 27.5% and a 16.6% reduction in average blood fructosamine when compared to original screening results of these 44 individuals. This study indicates that the addition of weekly fructosamine values to daily blood glucose values provides both the patient and clinician valuable information to evaluate the impact of dietary, exercise, and medication therapy changes on glycemic control by bridging the existing gap between daily blood glucose values and quarterly HbA1c confirmation of intervention results.

  20. Systematic review of the relationship of Helicobacter pylori infection with geographical latitude, average annual temperature and average daily sunshine.

    PubMed

    Lu, Chao; Yu, Ye; Li, Lan; Yu, Chaohui; Xu, Ping

    2018-04-17

    Helicobacter pylori (H. pylori) infection is a worldwide threat to human health with high prevalence. In this study, we analyzed the relationship between latitude, average annual temperature, average daily sunshine time and H. pylori infection. The PubMed, ClinicalTrials.gov , EBSCO and Web of Science databases were searched to identify studies reporting H. pylori infection. Latitude 30° was the cut-off level for low and mid-latitude areas. We obtained information for latitude, average annual temperature, average daily sunshine, and Human Development Index (HDI) from reports of studies of the relationships with H. pylori infection. Of the 51 studies included, there was significant difference in H. pylori infection between the low- and mid-latitude areas (P = 0.05). There was no significant difference in the prevalence of H. pylori infection in each 15°-latitude zone analyzed (P = 0.061). Subgroup analysis revealed the highest and lowest H. pylori infection rates in the developing regions at > 30° latitude subgroup and the developed regions at < 30° latitude subgroup, respectively (P < 0.001). Multivariate analysis showed that average annual temperature, average daily sunshine time and HDI were significantly correlated with H. pylori infection (P = 0.009, P < 0.001, P < 0.001), while there was no correlation between H. pylori infection and latitude. Our analysis showed that higher average annual temperature was associated with lower H. pylori infection rates, while average daily sunshine time correlated positively with H. pylori infection. HDI was also found to be a significant factor, with higher HDI associated with lower infection rates. These findings provide evidence that can be used to devise strategies for the prevention and control of H. pylori.

  1. Characteristics of a multisensor system for non invasive glucose monitoring with external validation and prospective evaluation.

    PubMed

    Caduff, Andreas; Mueller, Martin; Megej, Alexander; Dewarrat, Francois; Suri, Roland E; Klisic, Jelena; Donath, Marc; Zakharov, Pavel; Schaub, Dominik; Stahel, Werner A; Talary, Mark S

    2011-05-15

    The Multisensor Glucose Monitoring System (MGMS) features non invasive sensors for dielectric characterisation of the skin and underlying tissue in a wide frequency range (1 kHz-100 MHz, 1 and 2 GHz) as well as optical characterisation. In this paper we describe the results of using an MGMS in a miniaturised housing with fully integrated sensors and battery. Six patients with Type I Diabetes Mellitus (age 44±16 y; BMI 24.1±1.3 kg/m(2), duration of diabetes 27±12 y; HbA1c 7.3±1.0%) wore a single Multisensor at the upper arm position and performed a total of 45 in-clinic study days with 7 study days per patient on average (min. 5 and max. 10). Glucose changes were induced either orally or by i.v. glucose administration and the blood glucose was measured routinely. Several prospective data evaluation routines were applied to evaluate the data. The results are shown using one of the restrictive data evaluation routines, where measurements from the first 22 study days were used to train a linear regression model. The global model was then prospectively applied to the data of the remaining 23 study days to allow for an external validation of glucose prediction. The model application yielded a Mean Absolute Relative Difference of 40.8%, a Mean Absolute Difference of 51.9 mg dL(-1), and a correlation of 0.84 on average per study day. The Clarke error grid analyses showed 89.0% in A+B, 4.5% in C, 4.6% in D and 1.9% in the E region. Prospective application of a global, purely statistical model, demonstrates that glucose variations can be tracked non invasively by the MGMS in most cases under these conditions. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. Physiological characterization of putative high-affinity glucose transport protein Hxt2 of Saccharomyces cerevisiae by use of anti-synthetic peptide antibodies.

    PubMed Central

    Wendell, D L; Bisson, L F

    1993-01-01

    Characterization and quantification of the Hxt2 (hexose transport) protein of Saccharomyces cerevisiae indicate that it is one of a set of differentially expressed high-affinity glucose transporters. The protein product of the HXT2 gene was specifically detected by antibodies raised against a synthetic peptide encompassing the 13 carboxyl-terminal amino acids predicted by the HXT2 gene sequence. Hxt2 migrated in sodium dodecyl sulfate-polyacrylamide gel electrophoresis as a broad band or closely spaced doublet with an average M(r) of 47,000. Hxt2 cofractionated with the plasma membrane ATPase, Pma1, indicating that it is a plasma membrane protein. Hxt2 was not solubilized by high pH or urea but was solublized by detergents, which is characteristic of an integral membrane protein. Expression of the Hxt2 protein was measured under two different conditions that produce expression of high-affinity glucose transport: a medium shift from a high (2.0%) to a low (0.05%) glucose concentration (referred to below as high and low glucose) and growth from high to low glucose. Hxt2 as measured by immunoblotting increased 20-fold upon a shift from high-glucose to low-glucose medium, and the high-affinity glucose transport expressed had a strong HXT2-dependent component. Surprisingly, Hxt2 was not detectable when S. cerevisiae growing in high glucose approached glucose exhaustion, and the high-affinity glucose transport expressed under these conditions did not have an HXT2-dependent component. The role of Hxt2 in growth during aerobic batch culture in low-glucose medium was examined. An hxt2 null mutant grew and consumed glucose significantly more slowly than the wild type, and this phenotype correlated directly with appearance of the Hxt2 protein. Images PMID:8244939

  3. Perceptual Averaging in Individuals with Autism Spectrum Disorder.

    PubMed

    Corbett, Jennifer E; Venuti, Paola; Melcher, David

    2016-01-01

    There is mounting evidence that observers rely on statistical summaries of visual information to maintain stable and coherent perception. Sensitivity to the mean (or other prototypical value) of a visual feature (e.g., mean size) appears to be a pervasive process in human visual perception. Previous studies in individuals diagnosed with Autism Spectrum Disorder (ASD) have uncovered characteristic patterns of visual processing that suggest they may rely more on enhanced local representations of individual objects instead of computing such perceptual averages. To further explore the fundamental nature of abstract statistical representation in visual perception, we investigated perceptual averaging of mean size in a group of 12 high-functioning individuals diagnosed with ASD using simplified versions of two identification and adaptation tasks that elicited characteristic perceptual averaging effects in a control group of neurotypical participants. In Experiment 1, participants performed with above chance accuracy in recalling the mean size of a set of circles ( mean task ) despite poor accuracy in recalling individual circle sizes ( member task ). In Experiment 2, their judgments of single circle size were biased by mean size adaptation. Overall, these results suggest that individuals with ASD perceptually average information about sets of objects in the surrounding environment. Our results underscore the fundamental nature of perceptual averaging in vision, and further our understanding of how autistic individuals make sense of the external environment.

  4. Spatially averaged flow over a wavy boundary revisited

    USGS Publications Warehouse

    McLean, S.R.; Wolfe, S.R.; Nelson, J.M.

    1999-01-01

    Vertical profiles of streamwise velocity measured over bed forms are commonly used to deduce boundary shear stress for the purpose of estimating sediment transport. These profiles may be derived locally or from some sort of spatial average. Arguments for using the latter procedure are based on the assumption that spatial averaging of the momentum equation effectively removes local accelerations from the problem. Using analogies based on steady, uniform flows, it has been argued that the spatially averaged velocity profiles are approximately logarithmic and can be used to infer values of boundary shear stress. This technique of using logarithmic profiles is investigated using detailed laboratory measurements of flow structure and boundary shear stress over fixed two-dimensional bed forms. Spatial averages over the length of the bed form of mean velocity measurements at constant distances from the mean bed elevation yield vertical profiles that are highly logarithmic even though the effect of the bottom topography is observed throughout the water column. However, logarithmic fits of these averaged profiles do not yield accurate estimates of the measured total boundary shear stress. Copyright 1999 by the American Geophysical Union.

  5. 21 CFR 862.1340 - Urinary glucose (nonquantitative) test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Urinary glucose (nonquantitative) test system. 862... Test Systems § 862.1340 Urinary glucose (nonquantitative) test system. (a) Identification. A urinary glucose (nonquantitative) test system is a device intended to measure glucosuria (glucose in urine...

  6. 21 CFR 862.1340 - Urinary glucose (nonquantitative) test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Urinary glucose (nonquantitative) test system. 862... Test Systems § 862.1340 Urinary glucose (nonquantitative) test system. (a) Identification. A urinary glucose (nonquantitative) test system is a device intended to measure glucosuria (glucose in urine...

  7. The average chemical composition of the lunar surface

    NASA Technical Reports Server (NTRS)

    Turkevich, A. L.

    1973-01-01

    The available analytical data from twelve locations on the moon are used to estimate the average amounts of the principal chemical elements (O, Na, Mg, Al, Si, Ca, Ti, and Fe) in the mare, the terra, and the average lunar surface regolith. These chemical elements comprise about 99% of the atoms on the lunar surface. The relatively small variability in the amounts of these elements at different mare (or terra) sites, and the evidence from the orbital measurements of Apollo 15 and 16, suggest that the lunar surface is much more homogeneous than the surface of the earth. The average chemical composition of the lunar surface may now be known as well as, if not better than, that of the solid part of the earth's surface.

  8. Size and emotion averaging: costs of dividing attention after all.

    PubMed

    Brand, John; Oriet, Chris; Tottenham, Laurie Sykes

    2012-03-01

    Perceptual averaging is a process by which sets of similar items are represented by summary statistics such as their average size, luminance, or orientation. Researchers have argued that this process is automatic, able to be carried out without interference from concurrent processing. Here, we challenge this conclusion and demonstrate a reliable cost of computing the mean size of circles distinguished by colour (Experiments 1 and 2) and the mean emotionality of faces distinguished by sex (Experiment 3). We also test the viability of two strategies that could have allowed observers to guess the correct response without computing the average size or emotionality of both sets concurrently. We conclude that although two means can be computed concurrently, doing so incurs a cost of dividing attention.

  9. The Health Effects of Income Inequality: Averages and Disparities.

    PubMed

    Truesdale, Beth C; Jencks, Christopher

    2016-01-01

    Much research has investigated the association of income inequality with average life expectancy, usually finding negative correlations that are not very robust. A smaller body of work has investigated socioeconomic disparities in life expectancy, which have widened in many countries since 1980. These two lines of work should be seen as complementary because changes in average life expectancy are unlikely to affect all socioeconomic groups equally. Although most theories imply long and variable lags between changes in income inequality and changes in health, empirical evidence is confined largely to short-term effects. Rising income inequality can affect individuals in two ways. Direct effects change individuals' own income. Indirect effects change other people's income, which can then change a society's politics, customs, and ideals, altering the behavior even of those whose own income remains unchanged. Indirect effects can thus change both average health and the slope of the relationship between individual income and health.

  10. A Martian PFS average spectrum: Comparison with ISO SWS

    NASA Astrophysics Data System (ADS)

    Formisano, V.; Encrenaz, T.; Fonti, S.; Giuranna, M.; Grassi, D.; Hirsh, H.; Khatuntsev, I.; Ignatiev, N.; Lellouch, E.; Maturilli, A.; Moroz, V.; Orleanski, P.; Piccioni, G.; Rataj, M.; Saggin, B.; Zasova, L.

    2005-08-01

    The evaluation of the planetary Fourier spectrometer performance at Mars is presented by comparing an average spectrum with the ISO spectrum published by Lellouch et al. [2000. Planet. Space Sci. 48, 1393.]. First, the average conditions of Mars atmosphere are compared, then the mixing ratios of the major gases are evaluated. Major and minor bands of CO 2 are compared, from the point of view of features characteristics and bands depth. The spectral resolution is also compared using several solar lines. The result indicates that PFS radiance is valid to better than 1% in the wavenumber range 1800-4200 cm -1 for the average spectrum considered (1680 measurements). The PFS monochromatic transfer function generates an overshooting on the left-hand side of strong narrow lines (solar or atmospheric). The spectral resolution of PFS is of the order of 1.3 cm -1 or better. A large number of narrow features to be identified are discovered.

  11. Genuine non-self-averaging and ultraslow convergence in gelation.

    PubMed

    Cho, Y S; Mazza, M G; Kahng, B; Nagler, J

    2016-08-01

    In irreversible aggregation processes droplets or polymers of microscopic size successively coalesce until a large cluster of macroscopic scale forms. This gelation transition is widely believed to be self-averaging, meaning that the order parameter (the relative size of the largest connected cluster) attains well-defined values upon ensemble averaging with no sample-to-sample fluctuations in the thermodynamic limit. Here, we report on anomalous gelation transition types. Depending on the growth rate of the largest clusters, the gelation transition can show very diverse patterns as a function of the control parameter, which includes multiple stochastic discontinuous transitions, genuine non-self-averaging and ultraslow convergence of the transition point. Our framework may be helpful in understanding and controlling gelation.

  12. Perceived Average Orientation Reflects Effective Gist of the Surface.

    PubMed

    Cha, Oakyoon; Chong, Sang Chul

    2018-03-01

    The human ability to represent ensemble visual information, such as average orientation and size, has been suggested as the foundation of gist perception. To effectively summarize different groups of objects into the gist of a scene, observers should form ensembles separately for different groups, even when objects have similar visual features across groups. We hypothesized that the visual system utilizes perceptual groups characterized by spatial configuration and represents separate ensembles for different groups. Therefore, participants could not integrate ensembles of different perceptual groups on a task basis. We asked participants to determine the average orientation of visual elements comprising a surface with a contour situated inside. Although participants were asked to estimate the average orientation of all the elements, they ignored orientation signals embedded in the contour. This constraint may help the visual system to keep the visual features of occluding objects separate from those of the occluded objects.

  13. Testing averaged cosmology with type Ia supernovae and BAO data

    SciTech Connect

    Santos, B.; Alcaniz, J.S.; Coley, A.A.

    An important problem in precision cosmology is the determination of the effects of averaging and backreaction on observational predictions, particularly in view of the wealth of new observational data and improved statistical techniques. In this paper, we discuss the observational viability of a class of averaged cosmologies which consist of a simple parametrized phenomenological two-scale backreaction model with decoupled spatial curvature parameters. We perform a Bayesian model selection analysis and find that this class of averaged phenomenological cosmological models is favored with respect to the standard ΛCDM cosmological scenario when a joint analysis of current SNe Ia and BAO datamore » is performed. In particular, the analysis provides observational evidence for non-trivial spatial curvature.« less

  14. A novel multicomponent redox polymer nanobead based high performance non-enzymatic glucose sensor.

    PubMed

    Gopalan, A I; Muthuchamy, N; Komathi, S; Lee, K-P

    2016-10-15

    The fabrication of a highly sensitive electrochemical non-enzymatic glucose sensor based on copper nanoparticles (Cu NPs) dispersed in a graphene (G)-ferrocene (Fc) redox polymer multicomponent nanobead (MCNB) is reported. The preparation of MCNB involves three major steps, namely: i) the preparation of a poly(aniline-co-anthranilic acid)-grafted graphene (G-PANI(COOH), ii) the covalent linking of ferrocene to G-PANI(COOH) via a polyethylene imine (PEI), and iii) the electrodeposition of Cu NPs. The prepared MCNB (designated as G-PANI(COOH)-PEI-Fc/Cu-MCNB), contains a conductive G-PANI(COOH), electron mediating Fc, and electrocatalytic Cu NPs that make it suitable for ultrasensitive non-enzymatic electrochemical sensing. The morphology, structure, and electro activities of MCNB were characterized. Electrochemical measurements showed that the G-PANI(COOH)-PEI-Fc/Cu-MCNB/GCE modified electrode exhibited good electrocatalytic behavior towards the detection of glucose in a wide linear range (0.50 to 15mM), with a low detection limit (0.16mM) and high sensitivity (14.3µAmM(-1)cm(-2)). Besides, the G-PANI(COOH)-PEI-Fc/Cu-MCNB/GCE sensor electrode did not respond to the presence of electroactive interferrants (such as uric acid, ascorbic acid, and dopamine) and saccharides or carbohydrates (fructose, lactose, d-isoascorbic acid, and dextrin), demonstrating its selectivity towards glucose. The fabricated NEG sensor exhibited high precision for measuring glucose in serum samples, with an average RSD of 4.3% and results comparable to those of commercial glucose test strips. This reliability and stability of glucose sensing indicates that G-PANI(COOH)-PEI-Fc/Cu-MCNB/GCE would be a promising material for the non-enzymatic detection of glucose in physiological fluids. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. A virtual pebble game to ensemble average graph rigidity.

    PubMed

    González, Luis C; Wang, Hui; Livesay, Dennis R; Jacobs, Donald J

    2015-01-01

    The body-bar Pebble Game (PG) algorithm is commonly used to calculate network rigidity properties in proteins and polymeric materials. To account for fluctuating interactions such as hydrogen bonds, an ensemble of constraint topologies are sampled, and average network properties are obtained by averaging PG characterizations. At a simpler level of sophistication, Maxwell constraint counting (MCC) provides a rigorous lower bound for the number of internal degrees of freedom (DOF) within a body-bar network, and it is commonly employed to test if a molecular structure is globally under-constrained or over-constrained. MCC is a mean field approximation (MFA) that ignores spatial fluctuations of distance constraints by replacing the actual molecular structure by an effective medium that has distance constraints globally distributed with perfect uniform density. The Virtual Pebble Game (VPG) algorithm is a MFA that retains spatial inhomogeneity in the density of constraints on all length scales. Network fluctuations due to distance constraints that may be present or absent based on binary random dynamic variables are suppressed by replacing all possible constraint topology realizations with the probabilities that distance constraints are present. The VPG algorithm is isomorphic to the PG algorithm, where integers for counting "pebbles" placed on vertices or edges in the PG map to real numbers representing the probability to find a pebble. In the VPG, edges are assigned pebble capacities, and pebble movements become a continuous flow of probability within the network. Comparisons between the VPG and average PG results over a test set of proteins and disordered lattices demonstrate the VPG quantitatively estimates the ensemble average PG results well. The VPG performs about 20% faster than one PG, and it provides a pragmatic alternative to averaging PG rigidity characteristics over an ensemble of constraint topologies. The utility of the VPG falls in between the most

  16. Creating "Intelligent" Ensemble Averages Using a Process-Based Framework

    NASA Astrophysics Data System (ADS)

    Baker, Noel; Taylor, Patrick

    2014-05-01

    The CMIP5 archive contains future climate projections from over 50 models provided by dozens of modeling centers from around the world. Individual model projections, however, are subject to biases created by structural model uncertainties. As a result, ensemble averaging of multiple models is used to add value to individual model projections and construct a consensus projection. Previous reports for the IPCC establish climate change projections based on an equal-weighted average of all model projections. However, individual models reproduce certain climate processes better than other models. Should models be weighted based on performance? Unequal ensemble averages have previously been constructed using a variety of mean state metrics. What metrics are most relevant for constraining future climate projections? This project develops a framework for systematically testing metrics in models to identify optimal metrics for unequal weighting multi-model ensembles. The intention is to produce improved ("intelligent") unequal-weight ensemble averages. A unique aspect of this project is the construction and testing of climate process-based model evaluation metrics. A climate process-based metric is defined as a metric based on the relationship between two physically related climate variables—e.g., outgoing longwave radiation and surface temperature. Several climate process metrics are constructed using high-quality Earth radiation budget data from NASA's Clouds and Earth's Radiant Energy System (CERES) instrument in combination with surface temperature data sets. It is found that regional values of tested quantities can vary significantly when comparing the equal-weighted ensemble average and an ensemble weighted using the process-based metric. Additionally, this study investigates the dependence of the metric weighting scheme on the climate state using a combination of model simulations including a non-forced preindustrial control experiment, historical simulations, and

  17. Sodium salicylate restores the impaired insulin response to glucose and improves glucose tolerance in heroin addicts.

    PubMed

    Giugliano, D; Quatraro, A; Consoli, G; Stante, A; Simeone, V; Ceriello, A; Paolisso, G; Torella, R

    1987-01-01

    Plasma glucose, insulin, C-peptide, glucagon and growth hormone responses to intravenous glucose were evaluated in 10 heroin addicts in the basal state and during an infusion of sodium salicylate, an inhibitor of endogenous prostaglandin synthesis. Ten normal subjects, matched for age, sex and weight served as controls. In the basal state, the heroin addicts had markedly reduced insulin responses to intravenous glucose and low glucose disappearance rates (p less than 0.01 vs controls). The infusion of sodium salicylate caused a striking increase of the acute insulin response to intravenous glucose (from 14.5 +/- 4 microU/ml to 88 +/- 11 microU/ml, p less than 0.001) and restored to normal the reduced glucose tolerance (KG from 1.10 +/- 0.1% min-1 to 2.04 +/- 0.19% min-1). Hypoglycemic values were found in all addicts at the end of the test during salicylate infusion. Indomethacin pretreatment in five additional addicts also caused normalization of the impaired insulin responses to the intravenous glucose challenge and restored to normal the reduced glucose disappearance rate. Plasma glucagon and growth hormone levels were normally suppressed by glucose in addicts in basal conditions; sodium salicylate infusion completely overturned these hormonal responses which became positive in the first 15 min following the glucose challenge. These results demonstrate that the two prostaglandin synthesis inhibitors can restore the impaired B-cell response to glucose in heroin addicts to normal, indicating that this response is not lost but is inhibited by heroin itself or by other substances, perhaps by the endogenous prostaglandins.

  18. Dietary chromium tripicolinate supplementation reduces glucose concentrations and improves glucose tolerance in normal-weight cats.

    PubMed

    Appleton, D J; Rand, J S; Sunvold, G D; Priest, J

    2002-03-01

    The effect of dietary chromium supplementation on glucose and insulin metabolism in healthy, non-obese cats was evaluated. Thirty-two cats were randomly divided into four groups and fed experimental diets consisting of a standard diet with 0 ppb (control), 150 ppb, 300 ppb, or 600 ppb added chromium as chromium tripicolinate. Intravenous glucose tolerance, insulin tolerance and insulin sensitivity tests with minimal model analysis were performed before and after 6 weeks of feeding the test diets. During the glucose tolerance test, glucose concentrations, area under the glucose concentration-time curve, and glucose half-life (300 ppb only), were significantly lower after the trial in cats supplemented with 300 ppb and 600 ppb chromium, compared with values before the trial. Fasting glucose concentrations measured on a different day in the biochemistry profile were also significantly lower after supplementation with 600 ppb chromium. There were no significant differences in insulin concentrations or indices in either the glucose or insulin tolerance tests following chromium supplementation, nor were there any differences between groups before or after the dietary trial.Importantly, this study has shown a small but significant, dose-dependent improvement in glucose tolerance in healthy, non-obese cats supplemented with dietary chromium. Further long-term studies are warranted to determine if the addition of chromium to feline diets is advantageous. Cats most likely to benefit are those with glucose intolerance and insulin resistance from lack of exercise, obesity and old age. Healthy cats at risk of glucose intolerance and diabetes from underlying low insulin sensitivity or genetic factors may also benefit from long-term chromium supplementation. Copyright 2002 ESFM and AAFP.

  19. Glucose-dependent and Glucose-sensitizing Insulinotropic Effect of Nateglinide: Comparison to Sulfonylureas and Repaglinide

    PubMed Central

    Wang, Shuya; Dunning, Beth E.

    2001-01-01

    Nateglinide, a novel D-phenylalanine derivative, stimulates insulin release via closure of KATP channels in pancreatic β-cell, a primary mechanism of action it shares with sulfonylureas (SUs) and repaglinide. This study investigated (1) the influence of ambient glucose levels on the insulinotropic effects of nateglinide, glyburide and repaglinide, and (2) the influence of the antidiabetic agents on glucose-stimulated insulin secretion (GSIS) in vitro from isolated rat islets. The EC50 of nateglinide to stimulate insulin secretion was 14 μM in the presence of 3mM glucose and was reduced by 6-fold in 8mM glucose and by 16-fold in 16mM glucose, indicating a glucose-dependent insulinotropic effect. The actions of glyburide and repaglinide failed to demonstrate such a glucose concentration-dependent sensitization. When tested at fixed and equipotent concentrations (~2x EC50 in the presence of 8mM glucose) nateglinide and repaglinide shifted the EC50s for GSIS to the left by 1.7mM suggesting an enhancement of islet glucose sensitivity, while glimepiride and glyburide caused, respectively, no change and a right shift of the EC50. These data demonstrate that despite a common basic mechanism of action, the insulinotropic effects of different agents can be influenced differentially by ambient glucose and can differentially influence the islet responsiveness to glucose. Further, the present findings suggest that nateglinide may exert a more physiologic effect on insulin secretion than comparator agents and thereby have less propensity to elicit hypoglycemia in vivo. PMID:12369728

  20. In Vivo Glucose Monitoring Using Dual-Wavelength Polarimetry to Overcome Corneal Birefringence in the Presence of Motion

    PubMed Central

    Malik, Bilal H.; Gresham, Vincent C.; Coté, Gerard L.

    2012-01-01

    Abstract Objective Over the past 35 years considerable research has been performed toward the investigation of noninvasive and minimally invasive glucose monitoring techniques. Optical polarimetry is one noninvasive technique that has shown promise as a means to ascertain blood glucose levels through measuring the glucose concentrations in the anterior chamber of the eye. However, one of the key limitations to the use of optical polarimetry as a means to noninvasively measure glucose levels is the presence of sample noise caused by motion-induced time-varying corneal birefringence. Research Design and Methods In this article our group presents, for the first time, results that show dual-wavelength polarimetry can be used to accurately detect glucose concentrations in the presence of motion-induced birefringence in vivo using New Zealand White rabbits. Results In total, nine animal studies (three New Zealand White rabbits across three separate days) were conducted. Using the dual-wavelength optical polarimetric approach, in vivo, an overall mean average relative difference of 4.49% (11.66 mg/dL) was achieved with 100% Zone A+B hits on a Clarke error grid, including 100% falling in Zone A. Conclusions The results indicate that dual-wavelength polarimetry can effectively be used to significantly reduce the noise due to time-varying corneal birefringence in vivo, allowing the accurate measurement of glucose concentration in the aqueous humor of the eye and correlating that with blood glucose. PMID:22691020

  1. In vivo glucose monitoring using dual-wavelength polarimetry to overcome corneal birefringence in the presence of motion.

    PubMed

    Pirnstill, Casey W; Malik, Bilal H; Gresham, Vincent C; Coté, Gerard L

    2012-09-01

    Over the past 35 years considerable research has been performed toward the investigation of noninvasive and minimally invasive glucose monitoring techniques. Optical polarimetry is one noninvasive technique that has shown promise as a means to ascertain blood glucose levels through measuring the glucose concentrations in the anterior chamber of the eye. However, one of the key limitations to the use of optical polarimetry as a means to noninvasively measure glucose levels is the presence of sample noise caused by motion-induced time-varying corneal birefringence. In this article our group presents, for the first time, results that show dual-wavelength polarimetry can be used to accurately detect glucose concentrations in the presence of motion-induced birefringence in vivo using New Zealand White rabbits. In total, nine animal studies (three New Zealand White rabbits across three separate days) were conducted. Using the dual-wavelength optical polarimetric approach, in vivo, an overall mean average relative difference of 4.49% (11.66 mg/dL) was achieved with 100% Zone A+B hits on a Clarke error grid, including 100% falling in Zone A. The results indicate that dual-wavelength polarimetry can effectively be used to significantly reduce the noise due to time-varying corneal birefringence in vivo, allowing the accurate measurement of glucose concentration in the aqueous humor of the eye and correlating that with blood glucose.

  2. Dynamic Functional Imaging of Brain Glucose Utilization using fPET-FDG

    PubMed Central

    Villien, Marjorie; Wey, Hsiao-Ying; Mandeville, Joseph B.; Catana, Ciprian; Polimeni, Jonathan R.; Sander, Christin Y.; Zürcher, Nicole R.; Chonde, Daniel B.; Fowler, Joanna S.; Rosen, Bruce R.; Hooker, Jacob M.

    2014-01-01

    Glucose is the principal source of energy for the brain and yet the dynamic response of glucose utilization to changes in brain activity is still not fully understood. Positron emission tomography (PET) allows quantitative measurement of glucose metabolism using 2-[18F]-fluorodeoxyglucose (FDG). However, FDG PET in its current form provides an integral (or average) of glucose consumption over tens of minutes and lacks the temporal information to capture physiological alterations associated with changes in brain activity induced by tasks or drug challenges. Traditionally, changes in glucose utilization are inferred by comparing two separate scans, which significantly limits the utility of the method. We report a novel method to track changes in FDG metabolism dynamically, with higher temporal resolution than exists to date and within a single session. Using a constant infusion of FDG, we demonstrate that our technique (termed fPET-FDG) can be used in an analysis pipeline similar to fMRI to define within-session differential metabolic responses. We use visual stimulation to demonstrate the feasibility of this method. This new method has a great potential to be used in research protocols and clinical settings since fPET-FDG imaging can be performed with most PET scanners and data acquisition and analysis is straightforward. fPET-FDG is a highly complementary technique to MRI and provides a rich new way to observe functional changes in brain metabolism. PMID:24936683

  3. How to implement a clinical pathway for intensive glucose regulation in acute coronary syndromes.

    PubMed

    de Mulder, Maarten; Zwaan, Esther; Wielinga, Yvonne; Stam, Frank; Umans, Victor A W M

    2009-06-01

    Hyperglycemia upon admission of myocardial infarction patients predicts inferior clinical outcomes. Current strategies investigating hyperglycemia correction mostly use glucose-driven protocols. Implementation of these often labor-intensive protocols might be facilitated with the approach of a clinical pathway. Therefore, we evaluated the implementation of our glucose-driven protocol.We adapted a protocol for use in our coronary care unit (CCU), which was implemented according to the steps of a clinical pathway. To compensate for carbohydrates in meals we additionally developed a regimen of subcutaneous insulin.Protocol adherence was facilitated with a Web-based insulin calculator. All hyperglycemic patients admitted to the CCU were eligible for treatment according to this protocol.In a 4-month period, 643 glucose measurements were obtained in hyperglycemic patients admitted to our CCU. Patients were treated intensively with IV insulin for 35 hours and had 23 glucose measurements in this time span on average. This regimen achieved a median glucose of 6.2 mmol/L. Severe hypoglycemia occurred in only 1.1% of measurements and was without severe clinical side effects.Introduction of new intensive insulin protocol according to the steps of a clinical pathway is safe and feasible. The presence of a clinical pathway coordinator and sound communication are important conditions for successful introduction, which can be further aided with a computerized calculator.

  4. Dynamic functional imaging of brain glucose utilization using fPET-FDG

    DOE PAGES

    Villien, Marjorie; Wey, Hsiao-Ying; Mandeville, Joseph B.; ...

    2014-06-14

    We report that glucose is the principal source of energy for the brain and yet the dynamic response of glucose utilization to changes in brain activity is still not fully understood. Positron emission tomography (PET) allows quantitative measurement of glucose metabolism using 2-[18F]-fluorodeoxyglucose (FDG). However, FDG PET in its current form provides an integral (or average) of glucose consumption over tens of minutes and lacks the temporal information to capture physiological alterations associated with changes in brain activity induced by tasks or drug challenges. Traditionally, changes in glucose utilization are inferred by comparing two separate scans, which significantly limits themore » utility of the method. We report a novel method to track changes in FDG metabolism dynamically, with higher temporal resolution than exists to date and within a single session. Using a constant infusion of FDG, we demonstrate that our technique (termed fPET-FDG) can be used in an analysis pipeline similar to fMRI to define within-session differential metabolic responses. We use visual stimulation to demonstrate the feasibility of this method. Ultimately, this new method has a great potential to be used in research protocols and clinical settings since fPET-FDG imaging can be performed with most PET scanners and data acquisition and analysis are straightforward. fPET-FDG is a highly complementary technique to MRI and provides a rich new way to observe functional changes in brain metabolism.« less

  5. In Silico Assessment of Literature Insulin Bolus Calculation Methods Accounting for Glucose Rate of Change.

    PubMed

    Cappon, Giacomo; Marturano, Francesca; Vettoretti, Martina; Facchinetti, Andrea; Sparacino, Giovanni

    2018-05-01

    The standard formula (SF) used in bolus calculators (BCs) determines meal insulin bolus using "static" measurement of blood glucose concentration (BG) obtained by self-monitoring of blood glucose (SMBG) fingerprick device. Some methods have been proposed to improve efficacy of SF using "dynamic" information provided by continuous glucose monitoring (CGM), and, in particular, glucose rate of change (ROC). This article compares, in silico and in an ideal framework limiting the exposition to possibly confounding factors (such as CGM noise), the performance of three popular techniques devised for such a scope, that is, the methods of Buckingham et al (BU), Scheiner (SC), and Pettus and Edelman (PE). Using the UVa/Padova Type 1 diabetes simulator we generated data of 100 virtual subjects in noise-free, single-meal scenarios having different preprandial BG and ROC values. Meal insulin bolus was computed using SF, BU, SC, and PE. Performance was assessed with the blood glucose risk index (BGRI) on the 9 hours after meal. On average, BU, SC, and PE improve BGRI compared to SF. When BG is rapidly decreasing, PE obtains the best performance. In the other ROC scenarios, none of the considered methods prevails in all the preprandial BG conditions tested. Our study showed that, at least in the considered ideal framework, none of the methods to correct SF according to ROC is globally better than the others. Critical analysis of the results also suggests that further investigations are needed to develop more effective formulas to account for ROC information in BCs.

  6. Analysis of anhydrous glucose and human serum assisted by Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    González, Naara; Cerecedo-Núñez, H. H.; Padilla-Sosa, P.; Flores, Aaron; May, Manuel; Basurto, Miguel; Alcántara, Gabriela; Muñiz, Omar

    2017-02-01

    Raman spectroscopy has been considered like a potentially important clinical tool for real-time diagnosis of disease and evaluation of living tissue, whit the proposal to development noninvasive glucose measurements in a near future, with lower power than other reported studies, in this work are reported experimental tests made with a excitation source of semiconductor laser of 785 nm and 35 mW power. Measurements were made to different glucose concentrations, with variation from 50 mg/dL to 6000 mg/dL. For this, three intervals with different ranges of concentration were analyzed, these tests were put into plastic sampling cells, making incise the beam vertically on sample. In the same way measurements to serum human are reported, for healthy volunteers had 12 hours fasting and non-fasting conditions, with it's corresponding values of glucose taken through a conventional glucometer. Freeze-dried human serum was poured on object-holder, in the case of human serum reconstitute, it was used container in which were previously kept samples. Nine spectra per test were obtained and subsequently average was calculated, the spectra were studied in a range of 500 to 1700 cm-1. This work explores the intensity variation of the bands of glucose in 1065 cm-1 and 1127 cm-1 as a function of glucose concentration. In the obtained results, there observes a behavior with positive slope in both substances, interrelation being observed between the measurements, being promissory for non-invasive measurement.

  7. Average Weighted Receiving Time of Weighted Tetrahedron Koch Networks

    NASA Astrophysics Data System (ADS)

    Dai, Meifeng; Zhang, Danping; Ye, Dandan; Zhang, Cheng; Li, Lei

    2015-07-01

    We introduce weighted tetrahedron Koch networks with infinite weight factors, which are generalization of finite ones. The term of weighted time is firstly defined in this literature. The mean weighted first-passing time (MWFPT) and the average weighted receiving time (AWRT) are defined by weighted time accordingly. We study the AWRT with weight-dependent walk. Results show that the AWRT for a nontrivial weight factor sequence grows sublinearly with the network order. To investigate the reason of sublinearity, the average receiving time (ART) for four cases are discussed.

  8. 152 W average power Tm-doped fiber CPA system.

    PubMed

    Stutzki, Fabian; Gaida, Christian; Gebhardt, Martin; Jansen, Florian; Wienke, Andreas; Zeitner, Uwe; Fuchs, Frank; Jauregui, Cesar; Wandt, Dieter; Kracht, Dietmar; Limpert, Jens; Tünnermann, Andreas

    2014-08-15

    A high-power thulium (Tm)-doped fiber chirped-pulse amplification system emitting a record compressed average output power of 152 W and 4 MW peak power is demonstrated. This result is enabled by utilizing Tm-doped photonic crystal fibers with mode-field diameters of 35 μm, which mitigate detrimental nonlinearities, exhibit slope efficiencies of more than 50%, and allow for reaching a pump-power-limited average output power of 241 W. The high-compression efficiency has been achieved by using multilayer dielectric gratings with diffraction efficiencies higher than 98%.

  9. An improved switching converter model using discrete and average techniques

    NASA Technical Reports Server (NTRS)

    Shortt, D. J.; Lee, F. C.

    1982-01-01

    The nonlinear modeling and analysis of dc-dc converters has been done by averaging and discrete-sampling techniques. The averaging technique is simple, but inaccurate as the modulation frequencies approach the theoretical limit of one-half the switching frequency. The discrete technique is accurate even at high frequencies, but is very complex and cumbersome. An improved model is developed by combining the aforementioned techniques. This new model is easy to implement in circuit and state variable forms and is accurate to the theoretical limit.

  10. Using chromatogram averaging to improve quantitation of minor impurities.

    PubMed

    Zawatzky, Kerstin; Lin, Mingxiang; Schafer, Wes; Mao, Bing; Trapp, Oliver; Welch, Christopher J

    2016-09-23

    Averaging of chromatograms can lead to enhancement of signal to noise ratio (S/N) in proportion to the square root of the number of measurements. Although the general principle has been known for decades, chromatogram averaging is almost never used in current pharmaceutical research. In this study we explore the utility of this approach, showing it to be a simple and easily accessible method for boosting sensitivity for quantification of minor components and trace impurities, where current techniques deliver insufficient S/N. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. High average power scaleable thin-disk laser

    DOEpatents

    Beach, Raymond J.; Honea, Eric C.; Bibeau, Camille; Payne, Stephen A.; Powell, Howard; Krupke, William F.; Sutton, Steven B.

    2002-01-01

    Using a thin disk laser gain element with an undoped cap layer enables the scaling of lasers to extremely high average output power values. Ordinarily, the power scaling of such thin disk lasers is limited by the deleterious effects of amplified spontaneous emission. By using an undoped cap layer diffusion bonded to the thin disk, the onset of amplified spontaneous emission does not occur as readily as if no cap layer is used, and much larger transverse thin disks can be effectively used as laser gain elements. This invention can be used as a high average power laser for material processing applications as well as for weapon and air defense applications.

  12. Evaluating average and atypical response in radiation effects simulations

    NASA Astrophysics Data System (ADS)

    Weller, R. A.; Sternberg, A. L.; Massengill, L. W.; Schrimpf, R. D.; Fleetwood, D. M.

    2003-12-01

    We examine the limits of performing single-event simulations using pre-averaged radiation events. Geant4 simulations show the necessity, for future devices, to supplement current methods with ensemble averaging of device-level responses to physically realistic radiation events. Initial Monte Carlo simulations have generated a significant number of extremal events in local energy deposition. These simulations strongly suggest that proton strikes of sufficient energy, even those that initiate purely electronic interactions, can initiate device response capable in principle of producing single event upset or microdose damage in highly scaled devices.

  13. [SOMATOTYPE, NUTRITIONAL STATUS AND BLOOD GLUCOSE LEVEL OF PHYSICAL EDUCATION STUDENTS].

    PubMed

    Valdés-Badilla, Pablo; Salvador Soler, Noemí; Godoy-Cumillaf, Andrés; Carmona-López, María Ines; Fernández, Juan José; Durán-Agüero, Samuel

    2015-09-01

    classical studies have compared the glycemia with the nutritional status in both children and adults; however studies that consider also somatotype are unknown. associating the somatotype and nutritional status with the glycemic level of students of Pedagogy in Physical Education (PPE). the sample included 40 subjects, divided between 13 women and 27 men. It was determined in each subject BMI, somatotype and also a fasting blood glucose sample was obtained. the somatotype in male PPE students was mesomorphic (3-2-2) with a nutritional status of overweight (25 kg/m2) and balanced mesomorphic (4-4-2) with normal weight (22 kg/m2) in women PPE students. While average fasting blood glucose was 69 mg / dl. No association between somatotype and BMI with blood sugar levels of students of PPE, however, women of PEF showed significant positive correlations between mesomorphy and the ICC (0.577) and between glycemia and height (0.650). somatotype and BMI of the students of PPE are consistent with their age and sex, but no association between somatotype and glucose was observed. Moreover, the average blood glucose levels were somewhat lower compared to normative tables, a situation that could be related to physical activity, however, requires further study to confirm it. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  14. Functional Properties and Genomics of Glucose Transporters

    PubMed Central

    Zhao, Feng-Qi; Keating, Aileen F

    2007-01-01

    Glucose is the major energy source for mammalian cells as well as an important substrate for protein and lipid synthesis. Mammalian cells take up glucose from extracellular fluid into the cell through two families of structurallyrelated glucose transporters. The facilitative glucose transporter family (solute carriers SLC2A, protein symbol GLUT) mediates a bidirectional and energy-independent process of glucose transport in most tissues and cells, while the NaM+/glucose cotransporter family (solute carriers SLC5A, protein symbol SGLT) mediates an active, Na+-linked transport process against an electrochemical gradient. The GLUT family consists of thirteen members (GLUT1-12 and HMIT). Phylogenetically, the members of the GLUT family are split into three classes based on protein similarities. Up to now, at least six members of the SGLT family have been cloned (SGLT1-6). In this review, we report both the genomic structure and function of each transporter as well as intra-species comparative genomic analysis of some of these transporters. The affinity for glucose and transport kinetics of each transporter differs and ranges from 0.2 to 17mM. The ability of each protein to transport alternative substrates also differs and includes substrates such as fructose and galactose. In addition, the tissue distribution pattern varies between species. There are different regulation mechanisms of these transporters. Characterization of transcriptional control of some of the gene promoters has been investigated and alternative promoter usage to generate different protein isoforms has been demonstrated. We also introduce some pathophysiological roles of these transporters in human. PMID:18660845

  15. Averaging processes in granular flows driven by gravity

    NASA Astrophysics Data System (ADS)

    Rossi, Giulia; Armanini, Aronne

    2016-04-01

    One of the more promising theoretical frames to analyse the two-phase granular flows is offered by the similarity of their rheology with the kinetic theory of gases [1]. Granular flows can be considered a macroscopic equivalent of the molecular case: the collisions among molecules are compared to the collisions among grains at a macroscopic scale [2,3]. However there are important statistical differences in dealing with the two applications. In the two-phase fluid mechanics, there are two main types of average: the phasic average and the mass weighed average [4]. The kinetic theories assume that the size of atoms is so small, that the number of molecules in a control volume is infinite. With this assumption, the concentration (number of particles n) doesn't change during the averaging process and the two definitions of average coincide. This hypothesis is no more true in granular flows: contrary to gases, the dimension of a single particle becomes comparable to that of the control volume. For this reason, in a single realization the number of grain is constant and the two averages coincide; on the contrary, for more than one realization, n is no more constant and the two types of average lead to different results. Therefore, the ensamble average used in the standard kinetic theory (which usually is the phasic average) is suitable for the single realization, but not for several realization, as already pointed out in [5,6]. In the literature, three main length scales have been identified [7]: the smallest is the particles size, the intermediate consists in the local averaging (in order to describe some instability phenomena or secondary circulation) and the largest arises from phenomena such as large eddies in turbulence. Our aim is to solve the intermediate scale, by applying the mass weighted average, when dealing with more than one realizations. This statistical approach leads to additional diffusive terms in the continuity equation: starting from experimental

  16. Factors Affecting Accuracy and Time Requirements of a Glucose Oxidase-Peroxidase Assay for Determination of Glucose

    USDA-ARS?s Scientific Manuscript database

    Accurate and rapid assays for glucose are desirable for analysis of glucose and starch in food and feedstuffs. An established colorimetric glucose oxidase-peroxidase method for glucose was modified to reduce analysis time, and evaluated for factors that affected accuracy. Time required to perform t...

  17. Determination of Glucose Concentration in Yeast Culture Medium

    NASA Astrophysics Data System (ADS)

    Hara, Seiichi; Kishimoto, Tomokazu; Muraji, Masafumi; Tsujimoto, Hiroaki; Azuma, Masayuki; Ooshima, Hiroshi

    The present paper describes a sensor for measuring the glucose concentration of yeast culture medium. The sensor determines glucose concentration by measuring the yield of hydrogen peroxide produced by glucose oxidase, which is monitored as luminescence using photomultiplier. The present sensor is able to measure low glucose concentration in media in which yeast cells keep respiration state. We herein describe the system and the characteristics of the glucose sensor.

  18. [Evaluation of accuracy and influence factors of bedside blood glucose monitoring in critically ill patients].

    PubMed

    Feng, Tao; Cao, Xiang-yuan

    2012-08-01

    To evaluate the accuracy and influence factors of point-of-care testing (POCT) for glucose in critically ill patients. Two hundred and forty critically ill patients aged ≥18 years in department of critical care medicine were enrolled. According to blood glucose level (BGL) during glucose control, patients were divided into three groups: (1) hypoglycemia group, BGL<4.5 mmol/L, n=32; (2) euglycemia group, BGL 4.5-8.3 mmol/L, n=138; (3) hyperglycemia group, BGL>8.3 mmol/L, n=70. The blood samples from vein, artery and capillary of patients were collected synchronically and the blood glucose of POCT were determined with glucose oxidase (GOD) and glucose dehydrogenase (GDH) methods, respectively, compared with blood glucose reference values of laboratory [hexokinase method (HK method)]. The accuracy of POCT for glucose and influence factors were analyzed statistically by the logistic regression method. (1) The inaccurate rates of glucose values in blood samples from vein, artery and capillary in hypoglycemia group (GDH method: 25.00%, 40.62%, 40.62%; GOD method: 59.38%, 71.88%, 71.88%) were significantly higher than those in euglycemia group (GDH method: 2.90%, 9.42%, 7.97%; GOD method: 18.12%, 27.54%, 27.54%) and hyperglycemia group (GDH method: 1.43%, 8.57%, 4.28%; GOD method: 11.43%, 8.57%, 11.43%, all P<0.01). (2) The average levels of difference for the glucose reference value of laboratory and the glucose value measured by glucometer in hypoglycemia group were 0.41-0.69 mmol/L (GDH method) and 0.92-1.18 mmol/L (GOD method), in euglycemia 0.16-0.33 mmol/L and 0.77-0.90 mmol/L, in hyperglycemia group -0.06-0.18 mmol/L and 0.56-0.76 mmol/L, respectively. (3) The correlation coefficients between the laboratory and glucometer in hypoglycemia group were respectively 0.812-0.853 (GDH method) and 0.723-0.816 (GOD method). The correlation coefficients in euglycemia group were 0.862-0.890 and 0.768-0.857. They were elevated to 0.922-0.957 and 0.896-0.922 in hyperglycemia

  19. Hepatic glucose output in humans measured with labeled glucose to reduce negative errors

    SciTech Connect

    Levy, J.C.; Brown, G.; Matthews, D.R.

    Steele and others have suggested that minimizing changes in glucose specific activity when estimating hepatic glucose output (HGO) during glucose infusions could reduce non-steady-state errors. This approach was assessed in nondiabetic and type II diabetic subjects during constant low dose (27 mumol.kg ideal body wt (IBW)-1.min-1) glucose infusion followed by a 12 mmol/l hyperglycemic clamp. Eight subjects had paired tests with and without labeled infusions. Labeled infusion was used to compare HGO in 11 nondiabetic and 15 diabetic subjects. Whereas unlabeled infusions produced negative values for endogenous glucose output, labeled infusions largely eliminated this error and reduced the dependence ofmore » the Steele model on the pool fraction in the paired tests. By use of labeled infusions, 11 nondiabetic subjects suppressed HGO from 10.2 +/- 0.6 (SE) fasting to 0.8 +/- 0.9 mumol.kg IBW-1.min-1 after 90 min of glucose infusion and to -1.9 +/- 0.5 mumol.kg IBW-1.min-1 after 90 min of a 12 mmol/l glucose clamp, but 15 diabetic subjects suppressed only partially from 13.0 +/- 0.9 fasting to 5.7 +/- 1.2 at the end of the glucose infusion and 5.6 +/- 1.0 mumol.kg IBW-1.min-1 in the clamp (P = 0.02, 0.002, and less than 0.001, respectively).« less

  20. Biosensor based on glucose oxidase-nanoporous gold co-catalysis for glucose detection.

    PubMed

    Wu, Chao; Sun, Huihui; Li, Yufei; Liu, Xueying; Du, Xiaoyu; Wang, Xia; Xu, Ping

    2015-04-15

    Promoting the electrocatalytic oxidation of glucose is crucial in glucose biosensor design. In this study, nanoporous gold (NPG) was selected for glucose oxidase (GOx) immobilization and glucose biosensor fabrication because of its open, highly conductive, biocompatible, and interconnected porous structure, which also facilitates the electrocatalytic oxidation of glucose. The electrochemical reaction on the surface of the resulting GOx/NPG/GCE bioelectrode was attributed to the co-catalysis effect of GOx and NPG. A surface-confined reaction in a phosphate buffer solution was observed at the bioelectrode during cyclic voltammetry experiments. Linear responses were observed for large glucose concentrations ranging from 50μM to 10mM, with a high sensitivity of 12.1μAmM(-1)cm(-2) and a low detection limit of 1.02μM. Furthermore, the GOx/NPG/GCE bioelectrode presented strong anti-interference capability against cholesterol, urea, tributyrin, ascorbic acid, and uric acid, along with a long shelf-life. For the detection of glucose in human serum, the data generated by the GOx/NPG/GCE bioelectrode were in good agreement with those produced by an automatic biochemical analyzer. These unique properties make the GOx/NPG/GCE bioelectrode an excellent choice for the construction of a glucose biosensor. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. The interaction of insulin, glucose, and insulin-glucose mixtures with a phospholipid monolayer.

    PubMed

    Shigenobu, Hayato; McNamee, Cathy E

    2012-12-15

    We determined how glucose or insulin interacts with a phospholipid monolayer at the air/water interface and explained these mechanisms from a physico-chemical point of view. The 1,2-dipalmitoyl-2-sn-glycero-3-phosphatidylcholine (DPPC) monolayer at an air/water interface acted as a model membrane, which allowed the effect of the molecular packing density in the monolayer on the interactions to be determined. The interaction of glucose, insulin, and a mixture of glucose and insulin to the DPPC monolayer were investigated via surface pressure-area per molecule Langmuir isotherms and fluorescence microscopy. Glucose adsorbed to the underside of the DPPC monolayer, while insulin was able to penetrate through the monolayer when the phospholipid molecules were not densely packed. The presence of a mixture of insulin and glucose affected the molecular packing in the DPPC monolayer differently than the pure insulin or glucose solutions, and the glucose-insulin mixture was seen to be able to penetrate through the monolayer. These results indicated that glucose and insulin interact with one another, giving a material that may then transported through a pore in the monolayer or through the spaces between the molecules of the monolayer. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Ceylon cinnamon does not affect postprandial plasma glucose or insulin in subjects with impaired glucose tolerance.

    PubMed

    Wickenberg, Jennie; Lindstedt, Sandra; Berntorp, Kerstin; Nilsson, Jan; Hlebowicz, Joanna

    2012-06-01

    Previous studies on healthy subjects have shown that the intake of 6 g Cinnamomum cassia reduces postprandial glucose and that the intake of 3 g C. cassia reduces insulin response, without affecting postprandial glucose concentrations. Coumarin, which may damage the liver, is present in C. cassia, but not in Cinnamomum zeylanicum. The aim of the present study was to study the effect of C. zeylanicum on postprandial concentrations of plasma glucose, insulin, glycaemic index (GI) and insulinaemic index (GII) in subjects with impaired glucose tolerance (IGT). A total of ten subjects with IGT were assessed in a crossover trial. A standard 75 g oral glucose tolerance test (OGTT) was administered together with placebo or C. zeylanicum capsules. Finger-prick capillary blood samples were taken for glucose measurements and venous blood for insulin measurements, before and at 15, 30, 45, 60, 90, 120, 150 and 180 min after the start of the OGTT. The ingestion of 6 g C. zeylanicum had no significant effect on glucose level, insulin response, GI or GII. Ingestion of C. zeylanicum does not affect postprandial plasma glucose or insulin levels in human subjects. The Federal Institute for Risk Assessment in Europe has suggested the replacement of C. cassia by C. zeylanicum or the use of aqueous extracts of C. cassia to lower coumarin exposure. However, the positive effects seen with C. cassia in subjects with poor glycaemic control would then be lost.

  3. AVERAGE ANNUAL SOLAR UV DOSE OF THE CONTINENTAL US CITIZEN

    EPA Science Inventory

    The average annual solar UV dose of US citizens is not known, but is required for relative risk assessments of skin cancer from UV-emitting devices. We solved this problem using a novel approach. The EPA's "National Human Activity Pattern Survey" recorded the daily ou...

  4. 40 CFR 80.67 - Compliance on average.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 17 2014-07-01 2014-07-01 false Compliance on average. 80.67 Section... transferee's good faith belief that it was receiving valid credits; (ii) No refiner or importer may create... 60135, Nov. 6, 1997; 62 FR 68207, Dec. 31, 1997; 66 FR 37165, July 17, 2001; 71 FR 74568, Dec. 15, 2005...

  5. 40 CFR 80.67 - Compliance on average.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 17 2012-07-01 2012-07-01 false Compliance on average. 80.67 Section... transferee's good faith belief that it was receiving valid credits; (ii) No refiner or importer may create... 60135, Nov. 6, 1997; 62 FR 68207, Dec. 31, 1997; 66 FR 37165, July 17, 2001; 71 FR 74568, Dec. 15, 2005...

  6. 40 CFR 80.67 - Compliance on average.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 17 2013-07-01 2013-07-01 false Compliance on average. 80.67 Section... transferee's good faith belief that it was receiving valid credits; (ii) No refiner or importer may create... 60135, Nov. 6, 1997; 62 FR 68207, Dec. 31, 1997; 66 FR 37165, July 17, 2001; 71 FR 74568, Dec. 15, 2005...

  7. 40 CFR 80.67 - Compliance on average.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 16 2011-07-01 2011-07-01 false Compliance on average. 80.67 Section... transferee's good faith belief that it was receiving valid credits; (ii) No refiner or importer may create... 60135, Nov. 6, 1997; 62 FR 68207, Dec. 31, 1997; 66 FR 37165, July 17, 2001; 71 FR 74568, Dec. 15, 2005...

  8. 40 CFR 80.67 - Compliance on average.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Compliance on average. 80.67 Section... transferee's good faith belief that it was receiving valid credits; (ii) No refiner or importer may create... 60135, Nov. 6, 1997; 62 FR 68207, Dec. 31, 1997; 66 FR 37165, July 17, 2001; 71 FR 74568, Dec. 15, 2005...

  9. Speckle averaging system for laser raster-scan image projection

    DOEpatents

    Tiszauer, D.H.; Hackel, L.A.

    1998-03-17

    The viewers` perception of laser speckle in a laser-scanned image projection system is modified or eliminated by the addition of an optical deflection system that effectively presents a new speckle realization at each point on the viewing screen to each viewer for every scan across the field. The speckle averaging is accomplished without introduction of spurious imaging artifacts. 5 figs.

  10. Speckle averaging system for laser raster-scan image projection

    DOEpatents

    Tiszauer, Detlev H.; Hackel, Lloyd A.

    1998-03-17

    The viewers' perception of laser speckle in a laser-scanned image projection system is modified or eliminated by the addition of an optical deflection system that effectively presents a new speckle realization at each point on the viewing screen to each viewer for every scan across the field. The speckle averaging is accomplished without introduction of spurious imaging artifacts.

  11. Calculation of average landslide frequency using climatic records

    Treesearch

    L. M. Reid

    1998-01-01

    Abstract - Aerial photographs are used to develop a relationship between the number of debris slides generated during a hydrologic event and the size of the event, and the long-term average debris-slide frequency is calculated from climate records using the relation.

  12. 7 CFR 51.2561 - Average moisture content.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Average moisture content. 51.2561 Section 51.2561 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL...

  13. 7 CFR 51.2561 - Average moisture content.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Average moisture content. 51.2561 Section 51.2561 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL...

  14. 7 CFR 51.2561 - Average moisture content.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Average moisture content. 51.2561 Section 51.2561 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL...

  15. 7 CFR 51.2548 - Average moisture content determination.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Average moisture content determination. 51.2548 Section 51.2548 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE...

  16. 7 CFR 51.2548 - Average moisture content determination.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Average moisture content determination. 51.2548 Section 51.2548 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE...

  17. 7 CFR 51.2548 - Average moisture content determination.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Average moisture content determination. 51.2548 Section 51.2548 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE...

  18. 7 CFR 51.2548 - Average moisture content determination.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Average moisture content determination. 51.2548 Section 51.2548 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE...

  19. 7 CFR 51.2561 - Average moisture content.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Average moisture content. 51.2561 Section 51.2561 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL...

  20. Using Flexible Busing to Meet Average Class Size Targets

    ERIC Educational Resources Information Center

    Felt, Andrew J.; Koelemay, Ryan; Richter, Alexander

    2008-01-01

    This article describes a method of flexible redistricting for K-12 public school districts that allows students from the same geographical region to be bused to different schools, with the goal of meeting average class size (ACS) target ranges. Results of a case study on a geographically large school district comparing this method to a traditional…

  1. Time Series ARIMA Models of Undergraduate Grade Point Average.

    ERIC Educational Resources Information Center

    Rogers, Bruce G.

    The Auto-Regressive Integrated Moving Average (ARIMA) Models, often referred to as Box-Jenkins models, are regression methods for analyzing sequential dependent observations with large amounts of data. The Box-Jenkins approach, a three-stage procedure consisting of identification, estimation and diagnosis, was used to select the most appropriate…

  2. All above Average: Secondary School Improvement as an Impossible Endeavour

    ERIC Educational Resources Information Center

    Taylor, Phil

    2015-01-01

    This article argues that secondary school improvement in England, when viewed as a system, has become an impossible endeavour. This arises from the conflation of improvement with effectiveness, judged by a narrow range of outcome measures and driven by demands that all schools should somehow be above average. The expectation of comparable…

  3. 27 CFR 19.249 - Average effective tax rate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Average effective tax rate. 19.249 Section 19.249 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS DISTILLED SPIRITS PLANTS Distilled Spirits Taxes Effective Tax Rates § 19...

  4. The Effect of Honors Courses on Grade Point Averages

    ERIC Educational Resources Information Center

    Spisak, Art L.; Squires, Suzanne Carter

    2016-01-01

    High-ability entering college students give three main reasons for not choosing to become part of honors programs and colleges; they and/or their parents believe that honors classes at the university level require more work than non-honors courses, are more stressful, and will adversely affect their self-image and grade point average (GPA) (Hill;…

  5. Capillary Electrophoresis Sensitivity Enhancement Based on Adaptive Moving Average Method.

    PubMed

    Drevinskas, Tomas; Telksnys, Laimutis; Maruška, Audrius; Gorbatsova, Jelena; Kaljurand, Mihkel

    2018-06-05

    In the present work, we demonstrate a novel approach to improve the sensitivity of the "out of lab" portable capillary electrophoretic measurements. Nowadays, many signal enhancement methods are (i) underused (nonoptimal), (ii) overused (distorts the data), or (iii) inapplicable in field-portable instrumentation because of a lack of computational power. The described innovative migration velocity-adaptive moving average method uses an optimal averaging window size and can be easily implemented with a microcontroller. The contactless conductivity detection was used as a model for the development of a signal processing method and the demonstration of its impact on the sensitivity. The frequency characteristics of the recorded electropherograms and peaks were clarified. Higher electrophoretic mobility analytes exhibit higher-frequency peaks, whereas lower electrophoretic mobility analytes exhibit lower-frequency peaks. On the basis of the obtained data, a migration velocity-adaptive moving average algorithm was created, adapted, and programmed into capillary electrophoresis data-processing software. Employing the developed algorithm, each data point is processed depending on a certain migration time of the analyte. Because of the implemented migration velocity-adaptive moving average method, the signal-to-noise ratio improved up to 11 times for sampling frequency of 4.6 Hz and up to 22 times for sampling frequency of 25 Hz. This paper could potentially be used as a methodological guideline for the development of new smoothing algorithms that require adaptive conditions in capillary electrophoresis and other separation methods.

  6. Adaptive Spontaneous Transitions between Two Mechanisms of Numerical Averaging.

    PubMed

    Brezis, Noam; Bronfman, Zohar Z; Usher, Marius

    2015-06-04

    We investigated the mechanism with which humans estimate numerical averages. Participants were presented with 4, 8 or 16 (two-digit) numbers, serially and rapidly (2 numerals/second) and were instructed to convey the sequence average. As predicted by a dual, but not a single-component account, we found a non-monotonic influence of set-size on accuracy. Moreover, we observed a marked decrease in RT as set-size increases and RT-accuracy tradeoff in the 4-, but not in the 16-number condition. These results indicate that in accordance with the normative directive, participants spontaneously employ analytic/sequential thinking in the 4-number condition and intuitive/holistic thinking in the 16-number condition. When the presentation rate is extreme (10 items/sec) we find that, while performance still remains high, the estimations are now based on intuitive processing. The results are accounted for by a computational model postulating population-coding underlying intuitive-averaging and working-memory-mediated symbolic procedures underlying analytical-averaging, with flexible allocation between the two.

  7. The method of averages applied to the KS differential equations

    NASA Technical Reports Server (NTRS)

    Graf, O. F., Jr.; Mueller, A. C.; Starke, S. E.

    1977-01-01

    A new approach for the solution of artificial satellite trajectory problems is proposed. The basic idea is to apply an analytical solution method (the method of averages) to an appropriate formulation of the orbital mechanics equations of motion (the KS-element differential equations). The result is a set of transformed equations of motion that are more amenable to numerical solution.

  8. Reducing Noise by Repetition: Introduction to Signal Averaging

    ERIC Educational Resources Information Center

    Hassan, Umer; Anwar, Muhammad Sabieh

    2010-01-01

    This paper describes theory and experiments, taken from biophysics and physiological measurements, to illustrate the technique of signal averaging. In the process, students are introduced to the basic concepts of signal processing, such as digital filtering, Fourier transformation, baseline correction, pink and Gaussian noise, and the cross- and…

  9. Designing a Response Scale to Improve Average Group Response Reliability

    ERIC Educational Resources Information Center

    Davies, Randall

    2008-01-01

    Creating surveys is a common task in evaluation research; however, designing a survey instrument to gather average group response data that can be interpreted in a meaningful way over time can be challenging. When surveying groups of people for the purpose of longitudinal analysis, the reliability of the result is often determined by the response…

  10. 34 CFR 668.196 - Average rates appeals.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 3 2010-07-01 2010-07-01 false Average rates appeals. 668.196 Section 668.196 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF POSTSECONDARY EDUCATION, DEPARTMENT OF EDUCATION STUDENT ASSISTANCE GENERAL PROVISIONS Two Year Cohort Default Rates § 668...

  11. 34 CFR 668.215 - Average rates appeals.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 3 2010-07-01 2010-07-01 false Average rates appeals. 668.215 Section 668.215 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF POSTSECONDARY EDUCATION, DEPARTMENT OF EDUCATION STUDENT ASSISTANCE GENERAL PROVISIONS Cohort Default Rates § 668.215...

  12. Annual forest inventory estimates based on the moving average

    Treesearch

    Francis A. Roesch; James R. Steinman; Michael T. Thompson

    2002-01-01

    Three interpretations of the simple moving average estimator, as applied to the USDA Forest Service's annual forest inventory design, are presented. A corresponding approach to composite estimation over arbitrarily defined land areas and time intervals is given for each interpretation, under the assumption that the investigator is armed with only the spatial/...

  13. 40 CFR 63.652 - Emissions averaging provisions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... emissions average. This must include any Group 1 emission points to which the reference control technology... controls for a Group 1 emission point, the pollution prevention measure alone does not have to reduce... in control after November 15, 1990; (2) Group 1 emission points that are controlled by a reference...

  14. 40 CFR 63.652 - Emissions averaging provisions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... emissions average. This must include any Group 1 emission points to which the reference control technology... controls for a Group 1 emission point, the pollution prevention measure alone does not have to reduce... in control after November 15, 1990; (2) Group 1 emission points that are controlled by a reference...

  15. Effect of tank geometry on its average performance

    NASA Astrophysics Data System (ADS)

    Orlov, Aleksey A.; Tsimbalyuk, Alexandr F.; Malyugin, Roman V.; Leontieva, Daria A.; Kotelnikova, Alexandra A.

    2018-03-01

    The mathematical model of non-stationary filling of vertical submerged tanks with gaseous uranium hexafluoride is presented in the paper. There are calculations of the average productivity, heat exchange area, and filling time of various volumes tanks with smooth inner walls depending on their "height : radius" ratio as well as the average productivity, degree, and filling time of horizontal ribbing tank with volume 6.10-2 m3 with change central hole diameter of the ribs. It has been shown that the growth of "height / radius" ratio in tanks with smooth inner walls up to the limiting values allows significantly increasing tank average productivity and reducing its filling time. Growth of H/R ratio of tank with volume 1.0 m3 to the limiting values (in comparison with the standard tank having H/R equal 3.49) augments tank productivity by 23.5 % and the heat exchange area by 20%. Besides, we have demonstrated that maximum average productivity and a minimum filling time are reached for the tank with volume 6.10-2 m3 having central hole diameter of horizontal ribs 6.4.10-2 m.

  16. Grade Point Average: What's Wrong and What's the Alternative?

    ERIC Educational Resources Information Center

    Soh, Kay Cheng

    2011-01-01

    Grade point average (GPA) has been around for more than two centuries. However, it has created a lot of confusion, frustration, and anxiety to GPA-producers and users alike, especially when used across-nation for different purposes. This paper looks into the reasons for such a state of affairs from the perspective of educational measurement. It…

  17. Use of a Connected Glucose Meter and Certified Diabetes Educator Coaching to Decrease the Likelihood of Abnormal Blood Glucose Excursions: The Livongo for Diabetes Program.

    PubMed

    Downing, Janelle; Bollyky, Jenna; Schneider, Jennifer

    2017-07-11

    The Livongo for Diabetes Program offers members (1) a cellular technology-enabled, two-way messaging device that measures blood glucose (BG), centrally stores the glucose data, and delivers messages back to the individual in real time; (2) unlimited BG test strips; and (3) access to a diabetes coaching team for questions, goal setting, and automated support for abnormal glucose excursions. The program is sponsored by at-risk self-insured employers, health plans and provider organizations where it is free to members with diabetes or it is available directly to the person with diabetes where they cover the cost. The objective of our study was to evaluate BG data from 4544 individuals with diabetes who were enrolled in the Livongo program from October 2014 through December 2015. Members used the Livongo glucose meter to measure their BG levels an average of 1.8 times per day. We estimated the probability of having a day with a BG reading outside of the normal range (70-180 mg/dL, or 3.9-10.0 mmol/L) in months 2 to 12 compared with month 1 of the program, using individual fixed effects to control for individual characteristics. Livongo members experienced an average 18.4% decrease in the likelihood of having a day with hypoglycemia (BG <70 mg/dL) and an average 16.4% decrease in hyperglycemia (BG >180 mg/dL) in months 2-12 compared with month 1 as the baseline. The biggest impact was seen on hyperglycemia for nonusers of insulin. We do not know all of the contributing factors such as medication or other treatment changes during the study period. These findings suggest that access to a connected glucose meter and certified diabetes educator coaching is associated with a decrease in the likelihood of abnormal glucose excursions, which can lead to diabetes-related health care savings. ©Janelle Downing, Jenna Bollyky, Jennifer Schneider. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 11.07.2017.

  18. Identification of glucose-fermenting bacteria in a full-scale enhanced biological phosphorus removal plant by stable isotope probing.

    PubMed

    Nielsen, Jeppe Lund; Nguyen, Hien; Meyer, Rikke Louise; Nielsen, Per Halkjær

    2012-07-01

    Microbiology in wastewater treatment has mainly been focused on problem-causing filamentous bacteria or bacteria directly involved in nitrogen and phosphorus removal, and to a lesser degree on flanking groups, such as hydrolysing and fermenting bacteria. However, these groups constitute important suppliers of readily degradable substrates for the overall processes in the plant. This study aimed to identify glucose-fermenting bacteria in a full-scale enhanced biological phosphorus removal (EBPR) wastewater treatment plant (WWTP), and to determine their abundance in similar WWTPs. Glucose-fermenting micro-organisms were identified by an in situ approach using RNA-based stable isotope probing. Activated sludge was incubated anaerobically with (13)C(6)-labelled glucose, and (13)C-enriched rRNA was subsequently reverse-transcribed and used to construct a 16S rRNA gene clone library. Phylogenetic analysis of the library revealed the presence of two major phylogenetic groups of gram-positive bacteria affiliating with the genera Tetrasphaera, Propionicimonas (Actinobacteria), and Lactococcus and Streptococcus (Firmicutes). Specific oligonucleotide probes were designed for fluorescence in situ hybridization (FISH) to specifically target the glucose-fermenting bacteria identified in this study. The combination of FISH with microautoradiography confirmed that Tetrasphaera, Propionicimonas and Streptococcus were the dominant glucose fermenters. The probe-defined fermenters were quantified in 10 full-scale EBPR plants and averaged 39 % of the total biovolume. Tetrasphaera and Propionicimonas were the most abundant glucose fermenters (average 33 and 4 %, respectively), while Streptococcus and Lactococcus were present only in some WWTPs (average 1 and 0.4 %, respectively). Thus the population of actively metabolizing glucose fermenters seems to occupy a relatively large component of the total biovolume.

  19. Characterization of the intravenous glucose tolerance test and the combined glucose-insulin test in donkeys.

    PubMed

    Mendoza, F J; Aguilera-Aguilera, R; Gonzalez-De Cara, C A; Toribio, R E; Estepa, J C; Perez-Ecija, A

    2015-12-01

    Glucose-insulin dynamic challenges such as the intravenous glucose tolerance test (IVGTT) and combined glucose-insulin test (CGIT) have not been described in donkeys. The objectives of this study were (1) to characterize the IVGTT and CGIT in healthy adult donkeys, and (2) to establish normal glucose-insulin proxies. Sixteen donkeys were used and body morphometric variables obtained each. For the IVGTT, glucose (300 mg/kg) was given IV. For the CGIT, glucose (150 mg/kg) followed by recombinant insulin (0.1 IU/kg) were administered IV. Blood samples for glucose and insulin determinations were collected over 300 min. In the IVGTT the positive phase lasted 160.9 ± 13.3 min, glucose concentration peaked at 323.1 ± 9.2 mg/dL and declined at a rate of 1.28 ± 0.15 mg/dL/min. The glucose area under the curve (AUC) was 21.4 ± 1.9 × 10(3) mg/dL/min and the insulin AUC was 7.2 ± 0.9 × 10(3) µIU/mL/min. The positive phase of the CGIT curve lasted 44 ± 3 min, with a glucose clearance rate of 2.01 ± 0.18 mg/dL/min. The negative phase lasted 255.9 ± 3 min, decreasing glucose concentration at rate of -0.63 ± 0.06 mg/dL/min, and reaching a nadir (33.1 ± 3.6 mg/dL) at 118.3 ± 6.3 min. The glucose and insulin AUC values were 15.2 ± 0.9 × 10(3) mg/dL/min and 13.2 ± 0.9 × 10(3) µIU/mL/min. This is the first study characterizing CGIT and IVGTT, and glucose-insulin proxies in healthy adult donkeys. Distinct glucose dynamics, when compared with horses, support the use of species-specific protocols to assess endocrine function. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Predicted Blood Glucose from Insulin Administration Based on Values from Miscoded Glucose Meters

    PubMed Central

    Raine, Charles H.; Pardo, Scott; Parkes, Joan Lee

    2008-01-01

    Objectives The proper use of many types of self-monitored blood glucose (SMBG) meters requires calibration to match strip code. Studies have demonstrated the occurrence and impact on insulin dose of coding errors with SMBG meters. This paper reflects additional analyses performed with data from Raine et al. (JDST, 2:205–210, 2007). It attempts to relate potential insulin dose errors to possible adverse blood glucose outcomes when glucose meters are miscoded. Methods Five sets of glucose meters were used. Two sets of meters were autocoded and therefore could not be miscoded, and three sets required manual coding. Two of each set of manually coded meters were deliberately miscoded, and one from each set was properly coded. Subjects (n = 116) had finger stick blood glucose obtained at fasting, as well as at 1 and 2 hours after a fixed meal (Boost®; Novartis Medical Nutrition U.S., Basel, Switzerland). Deviations of meter blood glucose results from the reference method (YSI) were used to predict insulin dose errors and resultant blood glucose outcomes based on these deviations. Results Using insulin sensitivity data, it was determined that, given an actual blood glucose of 150–400 mg/dl, an error greater than +40 mg/dl would be required to calculate an insulin dose sufficient to produce a blood glucose of less than 70 mg/dl. Conversely, an error less than or equal to -70 mg/dl would be required to derive an insulin dose insufficient to correct an elevated blood glucose to less than 180 mg/dl. For miscoded meters, the estimated probability to produce a blood glucose reduction to less than or equal to 70 mg/dl was 10.40%. The corresponding probabilities for autocoded and correctly coded manual meters were 2.52% (p < 0.0001) and 1.46% (p < 0.0001), respectively. Furthermore, the errors from miscoded meters were large enough to produce a calculated blood glucose outcome less than or equal to 50 mg/dl in 42 of 833 instances. Autocoded meters produced zero (0) outcomes