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Sample records for enhancing glut-2 glucokinase

  1. Rosiglitazone stimulates the release and synthesis of insulin by enhancing GLUT-2, glucokinase and BETA2/NeuroD expression

    SciTech Connect

    Kim, Hyo-Sup; Noh, Jung-Hyun; Hong, Seung-Hyun; Hwang, You-Cheol; Yang, Tae-Young; Lee, Myung-Shik; Kim, Kwang-Won; Lee, Moon-Kyu

    2008-03-14

    Peroxisome proliferator-activated receptor (PPAR)-{gamma} is a member of the nuclear receptor superfamily, and its ligands, the thiazolidinediones, might directly stimulate insulin release and insulin synthesis in pancreatic {beta}-cells. In the present study, we examined the effects of rosiglitazone (RGZ) on insulin release and synthesis in pancreatic {beta}-cell (INS-1). Insulin release and synthesis were stimulated by treatment with RGZ for 24 h. RGZ upregulated the expressions of GLUT-2 and glucokinase (GCK). Moreover, it was found that RGZ increased the expression of BETA2/NeuroD gene which could regulate insulin gene expression. These results suggest that RGZ could stimulate the release and synthesis of insulin through the upregulation of GLUT-2, GCK, and BETA2/NeuroD gene expression.

  2. Myrtenal ameliorates hyperglycemia by enhancing GLUT2 through Akt in the skeletal muscle and liver of diabetic rats.

    PubMed

    Rathinam, Ayyasamy; Pari, Leelavinothan

    2016-08-25

    Insulin signaling pathway is an important role in glucose utilization in tissues. Our Previous study has established that myrtenal has antihyperglycemic effect against diabetic rats. The aim of this study was to explore the molecular mechanism of myrtenal in Streptozotocin-induced diabetic rats. Experimental diabetes was induced by single intraperitoneal injection of Streptozotocin (STZ) (40 mg/kg bw) in Wistar albino rats. Diabetic rats were administered myrtenal (80 mg/kg bw) for a period of 28 days. Diabetic rats showed an increased the levels of plasma glucose, decreased the levels of plasma insulin, down-regulation of insulin receptor substrate 2 (IRS2), Akt and glucose transporter 2 (GLUT2) in liver and insulin receptor substrate 2 (IRS2), Akt and glucose transporter 4 (GLUT4) protein expression in skeletal muscle. However, myrtenal treated diabetic rats revealed decreased the levels of plasma glucose, improved the plasma insulin levels, up-regulation of IRS2, Akt and GLUT2 in liver and IRS2, Akt and GLUT4 protein expression in skeletal muscle. The up-regulation of glucose transporters enhances the glucose uptake in liver and skeletal muscle. The histopathology and immunohistochemical analysis of the pancreas also corroborates with the above findings. Our findings suggest that myrtenal could be a potent phytochemical in the management of diabetes. PMID:27417257

  3. Exendin-4 enhances expression of Neurod1 and Glut2 in insulin-producing cells derived from mouse embryonic stem cells

    PubMed Central

    Zhao, Qiaoshi; Yang, Yuzhi; Hu, Jing; Shan, Zhiyan; Wu, Yanshuang

    2016-01-01

    Introduction Stem cells involved cell replacement therapies for type 1 diabetes mellitus is promising, yet time-consuming and inefficient. Exendin-4 is a glucagon-like peptide-1 (GLP-1) receptor agonist which has been reported to possess anti-apoptotic effects, thereby increasing β-cell mass and improving β-cell function. The present study aimed to investigate whether exendin-4 would enhance the differentiation of embryonic stem cells into insulin-secreting cells and improve the pancreatic differentiation strategy. Material and methods R1 embryonic stem cells were treated with different concentrations of exendin-4 and divided into three groups. In the high dosage group (group H), exendin-4 was added at the dosage of 10 nmol/l. In the low dosage group (group L), exendin-4 was added at the dosage of 0.1 nmol/l. Group C was a control. Expression of genes related to the β-cell phenotype and immunofluorescence staining of insulin and C-peptide were detected. Results Compared with groups L and C, group H had the highest mRNA expression levels of Isl1, Pdx1, Ngn3, and Insulin1 (p < 0.05). Neurod1 and Glut2 only emerged at the final stage of differentiation in group H. Immunofluorescence analysis revealed that exendin-4 upregulated the protein expression of insulin and C-peptide. Conclusions Exendin-4 remarkably facilitated Neurod1 and Glut2 gene transcription, and was able to induce differentiation of embryonic stem cells into endocrine and insulin-producing cells. PMID:26925137

  4. Effects of isoleucine on glucose uptake through the enhancement of muscular membrane concentrations of GLUT1 and GLUT4 and intestinal membrane concentrations of Na+/glucose co-transporter 1 (SGLT-1) and GLUT2.

    PubMed

    Zhang, Shihai; Yang, Qing; Ren, Man; Qiao, Shiyan; He, Pingli; Li, Defa; Zeng, Xiangfang

    2016-08-01

    Knowledge of regulation of glucose transport contributes to our understanding of whole-body glucose homoeostasis and human metabolic diseases. Isoleucine has been reported to participate in regulation of glucose levels in many studies; therefore, this study was designed to examine the effect of isoleucine on intestinal and muscular GLUT expressions. In an animal experiment, muscular GLUT and intestinal GLUT were determined in weaning pigs fed control or isoleucine-supplemented diets. Supplementation of isoleucine in the diet significantly increased piglet average daily gain, enhanced GLUT1 expression in red muscle and GLUT4 expression in red muscle, white muscle and intermediate muscle (P<0·05). In additional, expressions of Na+/glucose co-transporter 1 and GLUT2 were up-regulated in the small intestine when pigs were fed isoleucine-supplemented diets (P<0·05). C2C12 cells were used to examine the expressions of muscular GLUT and glucose uptake in vitro. In C2C12 cells supplemented with isoleucine in the medium, cellular 2-deoxyglucose uptake was increased (P<0·05) through enhancement of the expressions of GLUT4 and GLUT1 (P<0·05). The effect of isoleucine was greater than that of leucine on glucose uptake (P<0·05). Compared with newborn piglets, 35-d-old piglets have comparatively higher GLUT4, GLUT2 and GLUT5 expressions. The results of this study demonstrated that isoleucine supplementation enhanced the intestinal and muscular GLUT expressions, which have important implications that suggest that isoleucine could potentially increase muscle growth and intestinal development by enhancing local glucose uptake in animals and human beings. PMID:27464458

  5. GLUT2 Accumulation in Enterocyte Apical and Intracellular Membranes

    PubMed Central

    Ait-Omar, Amal; Monteiro-Sepulveda, Milena; Poitou, Christine; Le Gall, Maude; Cotillard, Aurélie; Gilet, Jules; Garbin, Kevin; Houllier, Anne; Château, Danièle; Lacombe, Amélie; Veyrie, Nicolas; Hugol, Danielle; Tordjman, Joan; Magnan, Christophe; Serradas, Patricia; Clément, Karine; Leturque, Armelle; Brot-Laroche, Edith

    2011-01-01

    OBJECTIVE In healthy rodents, intestinal sugar absorption in response to sugar-rich meals and insulin is regulated by GLUT2 in enterocyte plasma membranes. Loss of insulin action maintains apical GLUT2 location. In human enterocytes, apical GLUT2 location has not been reported but may be revealed under conditions of insulin resistance. RESEARCH DESIGN AND METHODS Subcellular location of GLUT2 in jejunal enterocytes was analyzed by confocal and electron microscopy imaging and Western blot in 62 well-phenotyped morbidly obese subjects and 7 lean human subjects. GLUT2 locations were assayed in ob/ob and ob/+ mice receiving oral metformin or in high-fat low-carbohydrate diet–fed C57Bl/6 mice. Glucose absorption and secretion were respectively estimated by oral glucose tolerance test and secretion of [U-14C]-3-O-methyl glucose into lumen. RESULTS In human enterocytes, GLUT2 was consistently located in basolateral membranes. Apical GLUT2 location was absent in lean subjects but was observed in 76% of obese subjects and correlated with insulin resistance and glycemia. In addition, intracellular accumulation of GLUT2 with early endosome antigen 1 (EEA1) was associated with reduced MGAT4a activity (glycosylation) in 39% of obese subjects on a low-carbohydrate/high-fat diet. Mice on a low-carbohydrate/high-fat diet for 12 months also exhibited endosomal GLUT2 accumulation and reduced glucose absorption. In ob/ob mice, metformin promoted apical GLUT2 and improved glucose homeostasis. Apical GLUT2 in fasting hyperglycemic ob/ob mice tripled glucose release into intestinal lumen. CONCLUSIONS In morbidly obese insulin-resistant subjects, GLUT2 was accumulated in apical and/or endosomal membranes of enterocytes. Functionally, apical GLUT2 favored and endosomal GLUT2 reduced glucose transepithelial exchanges. Thus, altered GLUT2 locations in enterocytes are a sign of intestinal adaptations to human metabolic pathology. PMID:21852673

  6. Does apical membrane GLUT2 have a role in intestinal glucose uptake?

    PubMed Central

    Naftalin, Richard J

    2014-01-01

    It has been proposed that the non-saturable component of intestinal glucose absorption, apparent following prolonged exposure to high intraluminal glucose concentrations, is mediated via the low affinity glucose and fructose transporter, GLUT2, upregulated within the small intestinal apical border. The evidence that the non-saturable transport component is mediated via an apical membrane sugar transporter is that it is inhibited by phloretin, after exposure to phloridzin. Since the other apical membrane sugar transporter, GLUT5, is insensitive to inhibition by either cytochalasin B, or phloretin, GLUT2 was deduced to be the low affinity sugar transport route. As in its uninhibited state, polarized intestinal glucose absorption depends both on coupled entry of glucose and sodium across the brush border membrane and on the enterocyte cytosolic glucose concentration exceeding that in both luminal and submucosal interstitial fluids, upregulation of GLUT2 within the intestinal brush border will usually stimulate downhill glucose reflux to the intestinal lumen from the enterocytes; thereby reducing, rather than enhancing net glucose absorption across the luminal surface. These states are simulated with a computer model generating solutions to the differential equations for glucose, Na and water flows between luminal, cell, interstitial and capillary compartments. The model demonstrates that uphill glucose transport via SGLT1 into enterocytes, when short-circuited by any passive glucose carrier in the apical membrane, such as GLUT2, will reduce transcellular glucose absorption and thereby lead to increased paracellular flow. The model also illustrates that apical GLUT2 may usefully act as an osmoregulator to prevent excessive enterocyte volume change with altered luminal glucose concentrations. PMID:25671087

  7. The ergogenic supplement β-hydroxy-β-methylbutyrate (HMB) attenuates insulin resistance through suppressing GLUT-2 in rat liver.

    PubMed

    Sharawy, Maha H; El-Awady, Mohammed S; Megahed, Nirmeen; Gameil, Nariman M

    2016-05-01

    This study investigates the effect of the ergogenic supplement β-hydroxy-β-methylbutyrate (HMB) on insulin resistance induced by high-fructose diet (HFD) in rats. Male Sprague Dawley rats were fed 60% HFD for 12 weeks and HMB (320 mg·kg(-1)·day(-1), orally) for 4 weeks. HFD significantly increased fasting insulin, fasting glucose, glycosylated hemoglobin (HBA1C), liver glycogen content, and homeostasis model assessment of insulin resistance (HOMA-IR) index, while it decreased glucose and insulin tolerance. Furthermore, HFD significantly increased serum triglycerides (TG), low density lipoprotein cholesterol (LDL-C), and very low density lipoprotein cholesterol (VLDL-C) levels, while it significantly decreased high density lipoprotein cholesterol (HDL-C). Moreover, HFD significantly increased mRNA expression of glucose transporter type-2 (GLUT-2), the mammalian target of rapamycin (mTOR), and sterol regulatory element-binding protein-1c (SREBP-1c) but decreased peroxisome proliferator-activated receptor-alpha (PPAR-α) in liver. Aortic relaxation to acetylcholine (ACh) was impaired and histopathology showed severe hepatic steatosis. HMB significantly increased insulin tolerance and decreased fasting insulin, HOMA-IR, HBA1C, hepatic glycogen content, serum TG, LDL-C, and VLDL-C. Additionally, HMB enhanced ACh-induced relaxation, ameliorated hepatic steatosis, and decreased mRNA expression of GLUT-2. In conclusion, HMB may attenuate insulin resistance and hepatic steatosis through inhibiting GLUT-2 in liver. PMID:26871756

  8. Hormonal and Metabolite Regulation of Hepatic Glucokinase.

    PubMed

    Agius, Loranne

    2016-07-17

    Liver glucose metabolism is dependent on glucokinase activity. Glucokinase expression is transcriptionally regulated by hormones and metabolites of glucose, and glucokinase activity is dependent on reversible binding of glucokinase to a specific inhibitor protein, glucokinase regulatory protein (GKRP), and to other binding proteins such as 6-phosphofructo-2-kinase/fructose 2,6-bisphosphatase (PFK2/FBP2), which functions as an activator. Glucokinase is inhibited in the postabsorptive state by sequestration in the nucleus bound to GKRP, and it is activated postprandially by portal hyperglycemia and fructose through dissociation from GKRP, translocation to the cytoplasm, and binding to PFK2/FBP2. Glucagon dissociates this interaction, promoting translocation back to the nucleus. In humans, changes in glucokinase expression and activity are associated with poorly controlled type 2 diabetes and with nonalcoholic fatty liver disease, and a common variant of GKRP with altered binding affinity for glucokinase is associated with increased blood and liver lipids and other metabolic traits that implicate a role for GKRP in maintaining intrahepatic metabolite homeostasis. PMID:27146014

  9. Comparative Structural and Functional Analysis of Staphylococcus aureus Glucokinase with other Bacterial Glucokinases

    PubMed Central

    Kumar, P. S.; Kumar, Y. N.; Prasad, U. V.; Yeswanth, S.; Swarupa, V.; Vasu, D.; Venkatesh, K.; Srikanth, L.; Rao, V. K.; Sarma, P. V. G. K.

    2014-01-01

    Glucokinase is classified in bacteria based upon having ATP binding site and ‘repressor/open reading frames of unknown function/sugar kinases’ motif, the sequence of glucokinase gene (JN645812) of Staphylococcus aureus ATCC12600 showed presence of ATP binding site and ‘repressor/open reading frames of unknown function/sugar kinases’ motif. We have earlier observed glucokinase of S. aureus has higher affinity towards the substrate compared to other bacterial glucokinase and under anaerobic condition with increased glucose concentration S. aureus exhibited higher rate of biofilm formation. To establish this, 3D structure of glucokinase was built using homology modeling method, the PROCHECK and ProSA-Web analysis indicated this built glucokinase structure was close to the crystal structure. This structure was superimposed with different bacterial glucokinase structures and from the root-mean-square deviation values, it is concluded that S. aureus glucokinase exhibited very close homology with Enterococcus faecalis and Clostridium difficle while with other bacteria it showed high degree of variations both in domain and nondomain regions. Glucose docking results indicated -12.3697 kcal/mol for S. aureus glucokinase compared with other bacterial glucokinase suggesting higher affinity of glucose which correlates with enzyme kinetics and higher rate of biofilm formation. PMID:25425757

  10. Fructose transporters GLUT5 and GLUT2 expression in adult patients with fructose intolerance

    PubMed Central

    Li, Xinhua; Ho, Sherry SY; Leong, Sai Mun; Wong, Reuben K; Koay, Evelyn SC; Ferraris, Ronaldo P

    2014-01-01

    Background Gastrointestinal symptoms and malabsorption following fructose ingestion (fructose intolerance) are common in functional gastrointestinal disorders (FGID). The underlying mechanism is unclear, but is hypothesized to be related an abnormality of intestinal fructose transporter proteins. Objective To assess the expression of the main intestinal fructose transporter proteins, glucose transport protein 5 (GLUT5) and 2 (GLUT2), in FGID. Methods The expression of GLUT5 and GLUT2 protein and mRNA in small intestinal biopsy tissue was investigated using real-time reverse-transcription PCR and Western immunoblotting in 11 adults with FGID and fructose intolerance ascertained by breath testing and in 15 controls. Results Median expression levels of GLUT5 mRNA normalized to beta-actin were 0.18 (interquartile range, IQR, 0.13–0.21) in patients and 0.17 (IQR 0.12–0.19) in controls (p > 0.05). Respective levels of GLUT2 mRNA were 0.26 (IQR 0.20–0.31) and 0.26 (IQR 0.19–0.31) (p > 0.05). Median expression levels of GLUT5 protein normalized to alpha-tubulin were 0.95 (IQR 0.52–1.68) in patients and 0.95 (IQR 0.59–1.15) in controls (p > 0.05). Respective protein expression levels for GLUT2 were 1.56 (IQR 1.06–2.14) and 1.35 (IQR 0.96–1.79) (p > 0.05). Conclusions Human fructose intolerance may not be associated with marked changes in GLUT5 and GLUT2 expression. Replication of these results in a larger subject group, including measures of transporter activation and membrane and subcellular localization, is warranted. PMID:24918004

  11. Insights into the role of neuronal glucokinase

    PubMed Central

    De Backer, Ivan; Hussain, Sufyan S.; Gardiner, James V.

    2016-01-01

    Glucokinase is a key component of the neuronal glucose-sensing mechanism and is expressed in brain regions that control a range of homeostatic processes. In this review, we detail recently identified roles for neuronal glucokinase in glucose homeostasis and counterregulatory responses to hypoglycemia and in regulating appetite. We describe clinical implications from these advances in our knowledge, especially for developing novel treatments for diabetes and obesity. Further research required to extend our knowledge and help our efforts to tackle the diabetes and obesity epidemics is suggested. PMID:27189932

  12. Insights into the role of neuronal glucokinase.

    PubMed

    De Backer, Ivan; Hussain, Sufyan S; Bloom, Stephen R; Gardiner, James V

    2016-07-01

    Glucokinase is a key component of the neuronal glucose-sensing mechanism and is expressed in brain regions that control a range of homeostatic processes. In this review, we detail recently identified roles for neuronal glucokinase in glucose homeostasis and counterregulatory responses to hypoglycemia and in regulating appetite. We describe clinical implications from these advances in our knowledge, especially for developing novel treatments for diabetes and obesity. Further research required to extend our knowledge and help our efforts to tackle the diabetes and obesity epidemics is suggested. PMID:27189932

  13. Attenuation of insulin resistance in rats by agmatine: role of SREBP-1c, mTOR and GLUT-2.

    PubMed

    Sharawy, Maha H; El-Awady, Mohammed S; Megahed, Nirmeen; Gameil, Nariman M

    2016-01-01

    Insulin resistance is a serious health condition worldwide; however, its exact mechanisms are still unclear. This study investigates agmatine (AGM; an endogenous metabolite of L-arginine) effects on insulin resistance induced by high fructose diet (HFD) in rats and the possible involved mechanisms. Sprague Dawley rats were fed 60% HFD for 12 weeks, and AGM (10 mg/kg/day, orally) was given from week 9 to 12. AGM significantly reduced HFD-induced elevation in fasting insulin level, homeostasis model assessment of insulin resistance (HOMA-IR) index and liver glycogen content from 3.44-, 3.62- and 2.07- to 2.59-, 2.78- and 1.3-fold, respectively, compared to the control group, while it increased HFD-induced reduction in glucose tolerance. Additionally, AGM significantly decreased HFD-induced elevation in serum triglycerides, low density lipoprotein cholesterol and very low density lipoprotein cholesterol levels from 3.18-, 2.97- and 4.75- to 1.25-, 1.25- and 1.07-fold, respectively, compared to control group. Conversely, AGM had no significant effect on HFD-induced changes in fasting glucose, glycosylated hemoglobin, insulin tolerance and high density lipoprotein cholesterol. Furthermore, AGM significantly reduced HFD-induced elevation in mRNA expression of glucose transporter type-2 (GLUT-2), mammalian target of rapamycin (mTOR) and sterol regulatory element-binding protein-1c (SREBP-1c) without affecting that of peroxisome proliferator-activated receptor-alpha (PPAR-α) in the liver. Additionally, AGM enhanced ACh-induced aortic relaxation and attenuated liver steatosis induced by HFD. In conclusion, AGM may have a therapeutic potential in insulin resistance through suppressing SREBP-1c, mTOR and GLUT-2 in liver. PMID:26449613

  14. Autoantibodies to the GLUT-2 glucose transporter of beta cells in insulin-dependent diabetes mellitus of recent onset.

    PubMed Central

    Inman, L R; McAllister, C T; Chen, L; Hughes, S; Newgard, C B; Kettman, J R; Unger, R H; Johnson, J H

    1993-01-01

    Purified immunoglobulin G (IgG) from the serum of patients with insulin-dependent diabetes mellitus (IDDM) of recent onset inhibits high-Km uptake of 3-O-methyl-beta-D-glucose by rat pancreatic islets. To determine if the inhibition is the result of antibodies against GLUT-2, the high-Km glucose transporter of beta cells, we incubated IDDM sera with rat islet cells and with AtT-20ins cells transfected to express GLUT-2. IDDM sera inhibited glucose uptake in islet cells and in GLUT-2-expressing AtT-20ins cells but not in AtT-20ins cells transfected to express the low-Km isoform, GLUT-1. In 24 of 30 (77%) patients with newly diagnosed IDDM, IgG binding as measured by immunofluorescence and flow cytometry of the cells transfected to express GLUT-2 was > 2 standard deviations from the mean of the nondiabetic population; 29 of 31 (96%) of nondiabetic children were negative (P < 0.0001). Increased IgG binding could be removed by absorption with GLUT-2-expressing cells but not with GLUT-1-expressing cells. We conclude that most patients with IDDM of recent onset have autoantibodies to GLUT-2. PMID:8433987

  15. Structure-Activity Relationship of Azaindole-Based Glucokinase Activators.

    PubMed

    Paczal, Attila; Bálint, Balázs; Wéber, Csaba; Szabó, Zoltán B; Ondi, Levente; Theret, Isabelle; De Ceuninck, Frédéric; Bernard, Catherine; Ktorza, Alain; Perron-Sierra, Francoise; Kotschy, András

    2016-01-28

    7-Azaindole has been identified as a novel bidentate anchor point for allosteric glucokinase activators. A systematic investigation around three principal parts of the new small molecule glucokinase activators led to a robust SAR in agreement with structural data that also helped to assess the conformational flexibility of the allosteric activation site. The increase in glucose uptake resulting from glucokinase activation in hepatocytes in vitro translated into the efficient lowering of glucose levels in vivo with the best compounds. PMID:26685731

  16. GLUT2 proteins and PPARγ transcripts levels are increased in liver of ovariectomized rats: reversal effects of resistance training

    PubMed Central

    Tomaz, Luciane M.; Barbosa, Marina R.; Farahnak, Zahra; Lagoeiro, Cristiani G.; Magosso, Natalia S.S; Lavoie, Jean-Marc; Perez, Sérgio E. A.

    2016-01-01

    [Purpose] This study investigated the effects of ovariectomy (Ovx) and 12 weeks of resistance training (RT) on gene expression of GLUT2, the main glucose transporter in the liver, and on PPARγ, a transcription factor known to target GLUT2 expression. [Methods] Forty Holtzman rats were divided into 5 groups: Sham-sedentary (Sed), Sham- RT, Ovx-Sed, Ovx-RT, and Ovx-Sed with hormone replacement (E2). The RT protocol consisted of sessions held every 72 h for 12 weeks, during which the animals performed 4 to 9 vertical climbs (1.1 m) at 2 min intervals with progressively heavier weights (30 g after the fourth climb) tied to the tail. The E2 silastic capsule was inserted into the rats’ backs 48 hours before the first RT session. [Results] In addition to liver fat, GLUT2 protein levels and PPARγ transcripts were increased (P < 0.05) in Ovx compared to Sham-Sed animals, suggesting increased hepatic glucose uptake under estrogen deficient conditions. RT and E2 in Ovx rats decreased liver fat accumulation as well as GLUT2 and PPARγ gene expression to the level of Sham- Sed animals. [Conclusion] The results of this study suggest that liver GLUT2 as well as PPARγ expression in Ovx rats are accompanied by increased fat accumulation and glucose uptake, thus providing a substrate for increased de novo lipogenesis. RT appears to be an appropriate exercise model to circumvent these effects. PMID:27508154

  17. Expression of the Human Glucokinase Gene: Important Roles of the 5′ Flanking and Intron 1 Sequences

    PubMed Central

    Li, Zhixin; Mao, Yiqing; Li, Hui; Wang, Xi; Wang, Rong; Xu, Wei; Song, Rongjing; Jin, Ling; Li, Xiuli; Irwin, David M.; Niu, Gang; Tan, Huanran

    2012-01-01

    Background Glucokinase plays important tissue-specific roles in human physiology, where it acts as a sensor of blood glucose levels in the pancreas, and a few other cells of the gut and brain, and as the rate-limiting step in glucose metabolism in the liver. Liver-specific expression is driven by one of the two tissue-specific promoters, and has an absolute requirement for insulin. The sequences that mediate regulation by insulin are incompletely understood. Methodology/Principal Findings To better understand the liver-specific expression of the human glucokinase gene we compared the structures of this gene from diverse mammals. Much of the sequence located between the 5′ pancreatic beta-cell-specific and downstream liver-specific promoters of the glucokinase genes is composed of repetitive DNA elements that were inserted in parallel on different mammalian lineages. The transcriptional activity of the liver-specific promoter 5′ flanking sequences were tested with and without downstream intronic sequences in two human liver cells lines, HepG2 and L-02. While glucokinase liver-specific 5′ flanking sequences support expression in liver cell lines, a sequence located about 2000 bases 3′ to the liver-specific mRNA start site represses gene expression. Enhanced reporter gene expression was observed in both cell lines when cells were treated with fetal calf serum, but only in the L-02 cells was expression enhanced by insulin. Conclusions/Significance Our results suggest that the normal liver L-02 cell line may be a better model to understand the regulation of the liver-specific expression of the human glucokinase gene. Our results also suggest that sequences downstream of the liver-specific mRNA start site have important roles in the regulation of liver-specific glucokinase gene expression. PMID:23029263

  18. Dual allosteric activation mechanisms in monomeric human glucokinase

    PubMed Central

    Whittington, A. Carl; Larion, Mioara; Bowler, Joseph M.; Ramsey, Kristen M.; Brüschweiler, Rafael; Miller, Brian G.

    2015-01-01

    Cooperativity in human glucokinase (GCK), the body’s primary glucose sensor and a major determinant of glucose homeostatic diseases, is fundamentally different from textbook models of allostery because GCK is monomeric and contains only one glucose-binding site. Prior work has demonstrated that millisecond timescale order-disorder transitions within the enzyme’s small domain govern cooperativity. Here, using limited proteolysis, we map the site of disorder in unliganded GCK to a 30-residue active-site loop that closes upon glucose binding. Positional randomization of the loop, coupled with genetic selection in a glucokinase-deficient bacterium, uncovers a hyperactive GCK variant with substantially reduced cooperativity. Biochemical and structural analysis of this loop variant and GCK variants associated with hyperinsulinemic hypoglycemia reveal two distinct mechanisms of enzyme activation. In α-type activation, glucose affinity is increased, the proteolytic susceptibility of the active site loop is suppressed and the 1H-13C heteronuclear multiple quantum coherence (HMQC) spectrum of 13C-Ile–labeled enzyme resembles the glucose-bound state. In β-type activation, glucose affinity is largely unchanged, proteolytic susceptibility of the loop is enhanced, and the 1H-13C HMQC spectrum reveals no perturbation in ensemble structure. Leveraging both activation mechanisms, we engineer a fully noncooperative GCK variant, whose functional properties are indistinguishable from other hexokinase isozymes, and which displays a 100-fold increase in catalytic efficiency over wild-type GCK. This work elucidates specific structural features responsible for generating allostery in a monomeric enzyme and suggests a general strategy for engineering cooperativity into proteins that lack the structural framework typical of traditional allosteric systems. PMID:26283387

  19. Present status of clinical deployment of glucokinase activators.

    PubMed

    Nakamura, Akinobu; Terauchi, Yasuo

    2015-03-01

    Glucokinase is one of four members of the hexokinase family of enzymes. Its expression is limited to the major organs (such as the pancreas, liver, brain and the gastrointestinal tract) that are thought to have an integrated role in glucose sensing. In the liver, phosphorylation of glucose by glucokinase promotes glycogen synthesis, whereas in the β-cells, it results in insulin release. Studies of glucokinase-linked genetically-modified mice and mutations in humans have illustrated the important roles played by glucokinase in whole-body glucose homeostasis, and suggest that the use of pharmacological agents that augment glucokinase activity could represent a viable treatment strategy in patients with type 2 diabetes. Since 2003, many glucokinase activators (GKAs) have been developed, and their ability to lower the blood glucose has been shown in several animal models of type 2 diabetes. Also, we and others have shown in mouse models that GKAs also have the effect of stimulating the proliferation of β-cells. However, the results of recent phase II trials have shown that GKAs lose their efficacy within several months of use, and that their use is associated with a high incidence of hypoglycemia; furthermore, patients treated with GKAs frequently developed dyslipidemia. A better understanding of the role of glucokinase in metabolic effects is required to resolve several issues identified in clinical trials. PMID:25802718

  20. Mutations in SLC2A2 Gene Reveal hGLUT2 Function in Pancreatic β Cell Development*

    PubMed Central

    Michau, Aurélien; Guillemain, Ghislaine; Grosfeld, Alexandra; Vuillaumier-Barrot, Sandrine; Grand, Teddy; Keck, Mathilde; L'Hoste, Sébastien; Chateau, Danielle; Serradas, Patricia; Teulon, Jacques; De Lonlay, Pascale; Scharfmann, Raphaël; Brot-Laroche, Edith; Leturque, Armelle; Le Gall, Maude

    2013-01-01

    The structure-function relationships of sugar transporter-receptor hGLUT2 coded by SLC2A2 and their impact on insulin secretion and β cell differentiation were investigated through the detailed characterization of a panel of mutations along the protein. We studied naturally occurring SLC2A2 variants or mutants: two single-nucleotide polymorphisms and four proposed inactivating mutations associated to Fanconi-Bickel syndrome. We also engineered mutations based on sequence alignment and conserved amino acids in selected domains. The single-nucleotide polymorphisms P68L and T110I did not impact on sugar transport as assayed in Xenopus oocytes. All the Fanconi-Bickel syndrome-associated mutations invalidated glucose transport by hGLUT2 either through absence of protein at the plasma membrane (G20D and S242R) or through loss of transport capacity despite membrane targeting (P417L and W444R), pointing out crucial amino acids for hGLUT2 transport function. In contrast, engineered mutants were located at the plasma membrane and able to transport sugar, albeit with modified kinetic parameters. Notably, these mutations resulted in gain of function. G20S and L368P mutations increased insulin secretion in the absence of glucose. In addition, these mutants increased insulin-positive cell differentiation when expressed in cultured rat embryonic pancreas. F295Y mutation induced β cell differentiation even in the absence of glucose, suggesting that mutated GLUT2, as a sugar receptor, triggers a signaling pathway independently of glucose transport and metabolism. Our results describe the first gain of function mutations for hGLUT2, revealing the importance of its receptor versus transporter function in pancreatic β cell development and insulin secretion. PMID:23986439

  1. Positive Regulatory Control Loop between Gut Leptin and Intestinal GLUT2/GLUT5 Transporters Links to Hepatic Metabolic Functions in Rodents

    PubMed Central

    Sakar, Yassine; Nazaret, Corinne; Lettéron, Philippe; Ait Omar, Amal; Avenati, Mathilde; Viollet, Benoît; Ducroc, Robert; Bado, André

    2009-01-01

    Background and Aims The small intestine is the major site of absorption of dietary sugars. The rate at which they enter and exit the intestine has a major effect on blood glucose homeostasis. In this study, we determine the effects of luminal leptin on activity/expression of GLUT2 and GLUT5 transporters in response to sugars intake and analyse their physiological consequences. Methodology Wistar rats, wild type and AMPKα2−/− mice were used. In vitro and in vivo isolated jejunal loops were used to quantify transport of fructose and galactose in the absence and the presence of leptin. The effects of fructose and galactose on gastric leptin release were determined. The effects of leptin given orally without or with fructose were determined on the expression of GLUT2/5, on some gluconeogenesis and lipogenic enzymes in the intestine and the liver. Principal Findings First, in vitro luminal leptin activating its receptors coupled to PKCβII and AMPKα, increased insertion of GLUT2/5 into the brush-border membrane leading to enhanced galactose and fructose transport. Second in vivo, oral fructose but not galactose induced in mice a rapid and potent release of gastric leptin in gastric juice without significant changes in plasma leptin levels. Moreover, leptin given orally at a dose reproducing comparable levels to those induced by fructose, stimulated GLUT5-fructose transport, and potentiated fructose-induced: i) increase in blood glucose and mRNA levels of key gluconeogenesis enzymes; ii) increase in blood triglycerides and reduction of mRNA levels of intestinal and hepatic Fasting-induced adipocyte factor (Fiaf) and iii) increase in SREBP-1c, ACC-1, FAS mRNA levels and dephosphorylation/activation of ACC-1 in liver. Conclusion/Significance These data identify for the first time a positive regulatory control loop between gut leptin and fructose in which fructose triggers release of gastric leptin which, in turn, up-regulates GLUT5 and concurrently modulates

  2. Partial structure of the mouse glucokinase gene

    SciTech Connect

    Ishimura-Oka, Kazumi; Chu, Mei-Jin; Sullivan, M.; Oka, Kazuhiro

    1995-10-10

    A complementary DNA for glucokinase (GK) was cloned from mouse liver total RNA by a combination of the polymerase chain reaction (PCR) and mouse liver cDNA library screening. Liver- and {beta}-cell-specific exons 1 were isolated by PCR using mouse and rat genomic DNAs. These clones were then used to screen a mouse genomic library; three genomic clones were isolated and characterized. The mouse GK gene spans over 20 kb, containing 11 exons including a liver- or {beta}-cell-specific exon 1, which encodes a tissue-specific 15-aa peptide at the N-terminus of the protein. Both types of GK contain 465 amino acid residues. The predicted amino acid sequence of mouse {beta}-cell-specific GK showed 98 and 96% identity to the rat and human enzymes, respectively; the corresponding values are 98 and 95% respectively, for the liver-specific GK. Several transcription factor-binding consensus sequences are identified in the 5{prime} flanking region of the mouse GK gene. 21 refs., 1 fig.

  3. Acetylation of glucokinase regulatory protein decreases glucose metabolism by suppressing glucokinase activity

    PubMed Central

    Park, Joo-Man; Kim, Tae-Hyun; Jo, Seong-Ho; Kim, Mi-Young; Ahn, Yong-Ho

    2015-01-01

    Glucokinase (GK), mainly expressed in the liver and pancreatic β-cells, is critical for maintaining glucose homeostasis. GK expression and kinase activity, respectively, are both modulated at the transcriptional and post-translational levels. Post-translationally, GK is regulated by binding the glucokinase regulatory protein (GKRP), resulting in GK retention in the nucleus and its inability to participate in cytosolic glycolysis. Although hepatic GKRP is known to be regulated by allosteric mechanisms, the precise details of modulation of GKRP activity, by post-translational modification, are not well known. Here, we demonstrate that GKRP is acetylated at Lys5 by the acetyltransferase p300. Acetylated GKRP is resistant to degradation by the ubiquitin-dependent proteasome pathway, suggesting that acetylation increases GKRP stability and binding to GK, further inhibiting GK nuclear export. Deacetylation of GKRP is effected by the NAD+-dependent, class III histone deacetylase SIRT2, which is inhibited by nicotinamide. Moreover, the livers of db/db obese, diabetic mice also show elevated GKRP acetylation, suggesting a broader, critical role in regulating blood glucose. Given that acetylated GKRP may affiliate with type-2 diabetes mellitus (T2DM), understanding the mechanism of GKRP acetylation in the liver could reveal novel targets within the GK-GKRP pathway, for treating T2DM and other metabolic pathologies. PMID:26620281

  4. Radiometric oil well assay for glucokinase in microscopic structures

    SciTech Connect

    Bedoya, F.J.; Meglasson, M.D.; Wilson, J.M.; Matschinsky, F.M.

    1985-02-01

    Glucokinase plays a pivotal role in hepatic glucose metabolism and serves as the glucose sensor in pancreatic islet beta-cells. Biochemical studies of this enzyme are complicated by the cellular heterogeneity of the liver and the pancreas and because the presence of hexokinases seriously interferes with currently available analytical procedures. A radiometric assay was designed to deal with these problems. It is based on the liberation of /sup 3/H/sub 2/O from D-(2-/sup 3/H(N))glucose 6-phosphate, the product of the glucokinase reaction, using exogenous phosphoglucose isomerase. Interference by hexokinases was largely eliminated by using glucose 6-phosphate as inhibitor and the sensitivity of the assay was greatly increased by using small volumes with the oil well procedure. The assay was sufficiently sensitive to detect about 1 pg of glucokinase. It thus allowed the application of quantitative histochemical procedures to the study of intralobular hepatic glucokinase profiles and the pancreatic beta-cell glucose sensor. The quantitative histochemical procedures were sufficiently sensitive and reliable for measuring important kinetic constants of glucokinase in microscopic samples of tissue.

  5. Roles of hepatic glucokinase in intertissue metabolic communication: Examination of novel liver-specific glucokinase knockout mice.

    PubMed

    Hayashi, Hirofumi; Sato, Yoshifumi; Li, Zhenghua; Yamamura, Ken-ichi; Yoshizawa, Tatsuya; Yamagata, Kazuya

    2015-05-01

    Glucokinase is expressed principally in pancreatic β-cells and hepatocytes, and catalyzes the phosphorylation of glucose to glucose-6-phosphate, a rate-limiting step of glycolysis. To better understand the roles of hepatic glucokinase, we generated Gck knockout mice by ablating liver-specific exon 1b. The knockout mice exhibited impaired glucose tolerance, decreased hepatic glycogen content, and reduced Pklr and Fas gene expression in the liver, indicating that hepatic glucokinase plays important roles in glucose metabolism. It has also been reported that hepatic glucokinase regulates the expression of thermogenesis-related genes in brown adipose tissue (BAT) and insulin secretion in response to glucose. However, the liver-specific Gck knockout mice displayed neither altered expression of thermogenesis-related genes in BAT nor impaired insulin secretion by β-cells under a normal chow diet. These results suggest that chronic suppression of hepatic glucokinase has a small influence on intertissue (liver-to-BAT as well as liver-to-β-cell) metabolic communication. PMID:25817793

  6. Determination of endopolyphosphatase using polyphosphate glucokinase.

    PubMed

    Kowalczyk, T H; Phillips, N F

    1993-07-01

    A method has been developed for determining endopolyphosphatase (polyphosphate depolymerase, EC 3.6.1.10) activity. The enzyme catalyzes the hydrolysis of inorganic polyphosphates [poly(Ps)] by cleaving internal phosphoanhydride bonds without removal of terminal phosphate residues. During the reaction, shorter poly(P) chains are formed and the molar concentration of poly(P) increases. This enzymatic activity is difficult to quantitate, because the substrates and products of the reaction are chemically identical. The commonly used viscometric method lacks sensitivity and cannot be used with shorter poly(P) substrates. The method described here overcomes these problems, and in addition is rapid, simple, and can be used for distinguishing between the endopolyphosphatase and exopolyphosphatase (EC 3.6.1.11) activities. It is based on monitoring the increase in the number of poly(P) chains generated by endopolyphosphatase. For this purpose, the method takes advantage of the specific property of poly(P) glucokinase (EC 2.7.1.63) which utilizes poly(Ps) of different sizes present in the endopolyphosphatase reaction mixture and reduces them to fairly uniform very short-chain product, poly(P)m. The concentration of poly(P)m is expressed in terms of acid-labile phosphorus and is proportional to the duration of the endopolyphosphatase reaction (i.e., the number of original poly(P) chains) and to protein concentration. The increase in the poly(P)m concentration is a relative measure of the endopolyphosphatase activity. Under certain conditions, m equals 3.5 and the activity can be expressed in standard units, since the exact number of poly(P) chains formed by endopolyphosphatase can be calculated from the increase in molar concentration of poly(P)3.5. Accuracy and advantages of the assay are discussed. PMID:8396361

  7. Cloning of genes that complement yeast hexokinase and glucokinase mutants.

    PubMed Central

    Walsh, R B; Kawasaki, G; Fraenkel, D G

    1983-01-01

    Genes complementing the glucose-negative fructose-negative Saccharomyces cerevisiae triple mutant strain (hxkl hxk2 glk1), which lacks hexokinase PI, hexokinase PII, and glucokinase, were obtained from a pool of yeast DNA in the multicopy plasmid YEp13. Images PMID:6341351

  8. Multiple Comparisons of Glucokinase Activation Mechanisms of Five Mulberry Bioactive Ingredients in Hepatocyte.

    PubMed

    He, Hao; Yu, Wan-Guo; Yang, Jun-Peng; Ge, Sheng; Lu, Yan-Hua

    2016-03-30

    Glucokinase (GK) activity, which is rapidly regulated by glucokinase regulatory protein (GKRP) in the liver, is crucial for blood glucose homeostasis. In this paper, the GK activation mechanisms of 1-deoxynojrimycin (DNJ), resveratrol (RES), oxyresveratrol (OXY), cyanidin-3-glucoside (C3G), and cyanidin-3-rutinoside (C3R) were compared. The results revealed that DNJ, RES, C3G, and C3R could differently improve glucose consumption and enhance intracellular GK activities. DNJ and RES significantly promoted GK translocation at 12.5 μM, whereas other ingredients showed moderate effects. DNJ, C3G, and C3R could rupture intramolecular hydrogen bonds of GK to accelerate its allosteric activation at early stage. RES and OXY could bind to a "hydrophobic pocket" on GK to stabilize the active GK at the final stage. Otherwise, RES, OXY, C3G, and C3R could interact with GKRP at the F1P binding site to promote GK dissociation and translocation. Enzymatic assay showed that RES (15-50 μM) and OXY (25-50 μM) could significantly enhance GK activities, which was caused by their binding properties with GK. Moreover, the most dramatic up-regulation effects on GK expression were observed in C3G and C3R groups. This work expounded the differences between GK activation mechanisms, and the new findings would help to develop new GK activators. PMID:26292150

  9. Non-contact measurement technique for enzymatic reaction of glucokinase

    NASA Astrophysics Data System (ADS)

    Staforelli, Juan P.; Gallardo, María. J.; Meza, Pablo; Torres, Sergio; Mella, Héctor; Reyes, Claudio

    2014-03-01

    A non-contact infrared imaging-based measurement technique is applied to quantify the enzymatic reaction of glucokinase. The method is implemented by a long-wave (8-12 [μm]) infrared microbolometer imaging array and a germanium-based infrared optical vision system adjusted to the size of a small biological sample. The enzymatic reaction is carried out by the glucokinase enzyme, which is representative of the internal dynamics of the cell. Such reactions produce a spontaneous exothermal release of energy detected by the infrared imaging system as a non-contact measurement technique. It is shown by stoichiometry computations and infrared thermal resolution metrics that the infrared imaging system can detect the energy release at the [mK] range. This allows to quantify the spontaneity of the enzymatic reaction in a three dimensional (surface and time) single and noncontact real- time measurement. The camera is characterized for disclosing its sensibility, and the fixed pattern noise is compensated by a two point calibration method. On the other hand, the glucokinase enzyme is isolated from Pyrococcus furiosus. Therefore, the experiment is carried out by manual injection with graduated micropipettes using 40 [μl] of glucokinase at the surface of the substrate contained in an eppendorf tube. For recording, the infrared camera is adjusted in-focus at 25.4 [mm] from the superficial level of the substrate. The obtained values of energy release are 139 +/- 22 [mK] at room temperature and 274 +/- 22 [mK] for a bath temperature of 334 [K].

  10. Oat β-glucan depresses SGLT1- and GLUT2-mediated glucose transport in intestinal epithelial cells (IEC-6).

    PubMed

    Abbasi, Nazanin N; Purslow, Peter P; Tosh, Susan M; Bakovic, Marica

    2016-06-01

    Oat β-glucan consumption is linked to reduced risk factors associated with diabetes and obesity by lowering glycemic response and serum level of low-density lipoproteins. The purpose of this study was to identify the mechanism of action of oat β-glucan at the interface between the gut wall and the lumen responsible for attenuating glucose levels. We proposed that viscous oat β-glucan acts as a physical barrier to glucose uptake in normally absorptive gut epithelial cells IEC-6 by affecting the expression of intestinal glucose transporters. Concentration and time-dependent changes in glucose uptake were established by using a nonmetabolizable glucose analog 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-d-glucose. The effectiveness of nutrient transport in IEC-6 cells was shown by significant differences in glucose uptake and corresponding transporter expression. The expressions of glucose transporters sodium-glucose-linked transport protein 1 (SGLT1) and glucose transporter 2 (GLUT2) increased with time (0-60 minutes) and glucose levels (5-25 mmol/L). The suppression of glucose uptake and SGLT1 and GLUT2 expression by increasing concentrations (4-8 mg/mL) of oat β-glucan demonstrated a direct effect of the physical properties of oat β-glucan on glucose transport. These results affirmed oat β-glucan as a dietary agent for minimizing postprandial glucose and showed that modulating the activity of the key intestinal glucose transporters with oat β-glucan could be an effective way of lowering blood glucose levels in patients with diabetes. PMID:27188900

  11. Effect of CCK-8 on pentose phosphate shunt activity, pyridine nucleotides, and glucokinase of rat islets

    SciTech Connect

    Verspohl, E.J.; Breuning, I.; Ammon, H.P.

    1989-01-01

    In rat pancreatic islets the effects of cholecystokinin octapeptide (CCK-8) on pentose phosphate shunt (PPS) activity, glucokinase and hexokinase activity, and NADPH, NADP+, NADH, and NAD+ were studied. By elevating the glucose concentration from 3.0 to 8.3 and 16.7 mM the oxidation of (1-14C)- and (6-14C)glucose and the calculated PPS activity were increased in a concentration-dependent manner; 10 nM CCK-8 enhanced selectively the effect on (1-14C)glucose oxidation thereby increasing the PPS activity but only at an intermediate glucose concentration (8.3 mM). CCK-8 had no effect on glucokinase or hexokinase activity and CCK-8 did not influence glucose utilization. By elevating the glucose concentration, total NADPH and NADH were increased and total NADP+ and NAD+ were decreased. CCK-8 (10 nM) increased selectively NADPH and decreased NADP+ but did not change NADH or NAD+; the effect of CCK-8 on NADPH and NADH was only observed in the presence of an intermediate stimulatory glucose concentration (8.3 mM) but not at either a substimulatory glucose concentration or a maximally stimulatory glucose concentration for insulin release (3.0 or 16.7 mM). The data indicate first that CCK-8 does not act on glucose phosphorylation or glucose utilization and second that CCK-8 increases PPS activity and NADPH levels in rat pancreatic islets. Since the concentrations of glucose necessary for these CCK-8 effects are in the range of 8.3 mM and parallel with those necessary for insulin release as shown in earlier observations, glucose oxidation via pentose phosphate shunt and NADPH are suggested to be related to the CCK-8-modulated insulin release.

  12. Insulin-positive, Glut2-low cells present within mouse pancreas exhibit lineage plasticity and are enriched within extra-islet endocrine cell clusters.

    PubMed

    Beamish, Christine A; Strutt, Brenda J; Arany, Edith J; Hill, David J

    2016-04-18

    Regeneration of insulin-producing β-cells from resident pancreas progenitors requires an understanding of both progenitor identity and lineage plasticity. One model suggested that a rare β-cell sub-population within islets demonstrated multi-lineage plasticity. We hypothesized that β-cells from young mice (postnatal day 7, P7) exhibit such plasticity and used a model of islet dedifferentiation toward a ductal epithelial-cell phenotype to test this theory. RIPCre;Z/AP(+/+) mice were used to lineage trace the fate of β-cells during dedifferentiation culture by a human placental alkaline phosphatase (HPAP) reporter. There was a significant loss of HPAP-expressing β-cells in culture, but remaining HPAP(+) cells lost insulin expression while gaining expression of the epithelial duct cell marker cytokeratin-19 (Ck19). Flow cytometry and recovery of β-cell subpopulations from whole pancreas vs. islets suggest that the HPAP(+)Ck19(+) cells had derived from insulin-positive, glucose-transporter-2-low (Ins(+)Glut2(LO)) cells, representing 3.5% of all insulin-expressing cells. The majority of these cells were found outside of islets within clusters of <5 β-cells. These insulin(+)Glut2(LO) cells demonstrated a greater proliferation rate in vivo and in vitro as compared to insulin(+)Glut2(+) cells at P7, were retained into adulthood, and a subset differentiated into endocrine, ductal, and neural lineages, illustrating substantial plasticity. Results were confirmed using RIPCre;ROSA- eYFP mice. Quantitative PCR data indicated these cells possess an immature β-cell phenotype. These Ins(+)Glut2(LO) cells may represent a resident population of cells capable of forming new, functional β-cells, and which may be potentially exploited for regenerative therapies in the future. PMID:27010375

  13. Psychological stress impairs Na+-dependent glucose absorption and increases GLUT2 expression in the rat jejunal brush-border membrane.

    PubMed

    Boudry, Gaëlle; Cheeseman, Christopher I; Perdue, Mary H

    2007-02-01

    Chronic psychological stress impacts many functions of the gastrointestinal tract. However, the effect of stress on nutrient absorption is poorly documented. This study was designed to investigate glucose transporters in rats submitted to different periods of water-avoidance stress (WAS). Rats were subjected to WAS (1 h/day) for 1, 5, or 10 consecutive days. Four hours after the last WAS session, rats were killed and segments of jejunum were mounted in Ussing chambers to study electrophysiological properties of the jejunum and Na+-dependent glucose absorption kinetics. Mucosa was obtained to prepare brush-border membrane vesicles (BBMV) used to measure [14C]fructose uptake as well as sodium-glucose transporter 1 (SGLT-1) and GLUT2 expression by Western blot analysis. Exposure of animals to WAS induced a decrease in Na+-dependent glucose absorption Vmax after 1, 5, and 10 days without any change in SGLT-1 expression. Potential difference across the jejunum was decreased for all stressed groups. Furthermore, we observed an increase in phloretin-sensitive uptake of [14C]fructose by BBMV after 1, 5, or 10 days of WAS, which was not present in control animals. This suggested the abnormal appearance of GLUT2 in the brush border, which was confirmed by Western blot analysis. We concluded that psychological stress induces major changes in glucose transport with a decrease in Na+-dependent glucose absorption and an increase in GLUT2 expression at the brush-border membrane level. PMID:17053095

  14. Insulin secretion impairment in Sirt6 knockout pancreatic β cells is mediated by suppression of the FoxO1-Pdx1-Glut2 pathway

    PubMed Central

    Song, Mi-Young; Wang, Jie; Ka, Sun-O; Bae, Eun Ju; Park, Byung-Hyun

    2016-01-01

    Sirtuin 6 (Sirt6), a chromatin associated class III deacetylase, controls whole-body energy homeostasis and has a critical role in glucose-stimulated insulin secretion (GSIS) in pancreatic β cells. However, its underlying molecular mechanism remains poorly understood. To gain further insights, we studied the pathway by which Sirt6 regulates GSIS utilizing mice lacking Sirt6 in their β cells (βS6KO). Further, we overexpressed wild type or deacetylase-inactive mutant Sirt6 in isolated islets as well as in MIN6 cells. We confirmed that βS6KO mice developed glucose intolerance with severely impaired GSIS. Gene expression analysis of knockout islets and overexpression studies demonstrated that Sirt6 deacetylates forkhead box protein O1 (FoxO1) to trigger its nuclear export and releases its transcriptional repression of key glucose sensing genes such as Pdx1 and Glut2. Ectopic overexpression of Sirt6 in knockout islets resulted in rescue of the defective insulin secretion and restoration of the expression of Pdx1 and Glut2. These results show that Sirt6 in pancreatic β cells deacetylates FoxO1 and subsequently increases the expression of Pdx1 and Glut2 to maintain the glucose-sensing ability of pancreatic β cells and systemic glucose tolerance. PMID:27457971

  15. Insulin secretion impairment in Sirt6 knockout pancreatic β cells is mediated by suppression of the FoxO1-Pdx1-Glut2 pathway.

    PubMed

    Song, Mi-Young; Wang, Jie; Ka, Sun-O; Bae, Eun Ju; Park, Byung-Hyun

    2016-01-01

    Sirtuin 6 (Sirt6), a chromatin associated class III deacetylase, controls whole-body energy homeostasis and has a critical role in glucose-stimulated insulin secretion (GSIS) in pancreatic β cells. However, its underlying molecular mechanism remains poorly understood. To gain further insights, we studied the pathway by which Sirt6 regulates GSIS utilizing mice lacking Sirt6 in their β cells (βS6KO). Further, we overexpressed wild type or deacetylase-inactive mutant Sirt6 in isolated islets as well as in MIN6 cells. We confirmed that βS6KO mice developed glucose intolerance with severely impaired GSIS. Gene expression analysis of knockout islets and overexpression studies demonstrated that Sirt6 deacetylates forkhead box protein O1 (FoxO1) to trigger its nuclear export and releases its transcriptional repression of key glucose sensing genes such as Pdx1 and Glut2. Ectopic overexpression of Sirt6 in knockout islets resulted in rescue of the defective insulin secretion and restoration of the expression of Pdx1 and Glut2. These results show that Sirt6 in pancreatic β cells deacetylates FoxO1 and subsequently increases the expression of Pdx1 and Glut2 to maintain the glucose-sensing ability of pancreatic β cells and systemic glucose tolerance. PMID:27457971

  16. The Hepatoselective Glucokinase Activator PF-04991532 Ameliorates Hyperglycemia without Causing Hepatic Steatosis in Diabetic Rats

    PubMed Central

    Erion, Derek M.; Lapworth, Amanda; Amor, Paul A.; Bai, Guoyun; Vera, Nicholas B.; Clark, Ronald W.; Yan, Qingyun; Zhu, Yimin; Ross, Trenton T.; Purkal, Julie; Gorgoglione, Matthew; Zhang, Guodong; Bonato, Vinicius; Baker, Levenia; Barucci, Nicole; D’Aquila, Theresa; Robertson, Alan; Aiello, Robert J.; Yan, Jiangli; Trimmer, Jeff; Rolph, Timothy P.; Pfefferkorn, Jeffrey A.

    2014-01-01

    Hyperglycemia resulting from type 2 diabetes mellitus (T2DM) is the main cause of diabetic complications such as retinopathy and neuropathy. A reduction in hyperglycemia has been shown to prevent these associated complications supporting the importance of glucose control. Glucokinase converts glucose to glucose-6-phosphate and determines glucose flux into the β-cells and hepatocytes. Since activation of glucokinase in β-cells is associated with increased risk of hypoglycemia, we hypothesized that selectively activating hepatic glucokinase would reduce fasting and postprandial glucose with minimal risk of hypoglycemia. Previous studies have shown that hepatic glucokinase overexpression is able to restore glucose homeostasis in diabetic models; however, these overexpression experiments have also revealed that excessive increases in hepatic glucokinase activity may also cause hepatosteatosis. Herein we sought to evaluate whether liver specific pharmacological activation of hepatic glucokinase is an effective strategy to reduce hyperglycemia without causing adverse hepatic lipids changes. To test this hypothesis, we evaluated a hepatoselective glucokinase activator, PF-04991532, in Goto-Kakizaki rats. In these studies, PF-04991532 reduced plasma glucose concentrations independent of changes in insulin concentrations in a dose-dependent manner both acutely and after 28 days of sub-chronic treatment. During a hyperglycemic clamp in Goto-Kakizaki rats, the glucose infusion rate was increased approximately 5-fold with PF-04991532. This increase in glucose infusion can be partially attributed to the 60% reduction in endogenous glucose production. While PF-04991532 induced dose-dependent increases in plasma triglyceride concentrations it had no effect on hepatic triglyceride concentrations in Goto-Kakizaki rats. Interestingly, PF-04991532 decreased intracellular AMP concentrations and increased hepatic futile cycling. These data suggest that hepatoselective glucokinase

  17. GLUT2 (SLC2A2) is not the principal glucose transporter in human pancreatic beta cells: implications for understanding genetic association signals at this locus.

    PubMed

    McCulloch, Laura J; van de Bunt, Martijn; Braun, Matthias; Frayn, Keith N; Clark, Anne; Gloyn, Anna L

    2011-12-01

    SLC2A2 encoding glucose transporter -2 (GLUT2) acts as the primary glucose transporter and sensor in rodent pancreatic islets and is widely assumed to play a similar role in humans. In healthy adults SLC2A2 variants are associated with elevated fasting plasma glucose (fpg) concentrations but physiological characterisation does not support a defect in pancreatic beta-cell function. Interspecies differences can create barriers for the follow up of disease association signals. We hypothesised that GLUT2 is not the principal glucose transporter in human beta-cells and that SLC2A2 variants exert their effect on fpg levels through defects in other tissues. SLC2A1-4 (GLUT 1-4) mRNA expression levels were determined in human and mouse islets, beta-cells, liver, muscle and adipose tissue by qRT-PCR whilst GLUT1-3 protein levels were examined by immunohistochemistry. The presence of all three glucose transporters was demonstrated in human and mouse islets and purified beta-cells. Quantitative expression profiling demonstrated that Slc2a2 is the predominant glucose transporter (expression >10 fold higher that Slc2a1) in mouse islets whilst SLC2A1 and SLC2A3 predominate in both human islets and beta-cells (expression 2.8 and 2.7 fold higher than SLC2A2 respectively). Our data therefore suggest that GLUT2 is unlikely to be the principal glucose transporter in human beta-cells and that SLC2A2 defects in other metabolic tissues drive the observed differences in glucose levels between carriers of SLC2A2 variants. Direct extrapolation from rodent to human islet glucose transporter activity is unlikely to be appropriate. PMID:21920790

  18. Sequence variations of the pancreatic islet/liver glucose transporter (GLUT2) gene in Japanese subjects with noninsulin dependent diabetes mellitus

    SciTech Connect

    Matsubara, Atsushi; Tanizawa, Yukio; Matsutani, Akira

    1995-10-01

    To assess the genetic susceptibility to noninsulin-dependent diabetes mellitus (NIDDM) in Japanese subjects, we investigated the role of GLUT2 gene defects in patients with NIDDM. When the allelic frequency of a simple tandem repeat polymorphism in the GLUT2 gene was compared, the allele with 155 base pairs was more common in NIDDM patients (n = 99) than in controls (n = 89; 5.1% v. 0.6%; P = 0.0118, by Fisher`s exact test), whereas this was not significant after the correction for multiple comparisons. To directly identify mutations, we then analyzed each of 11 exons by the polymerase chain reaction-single strand conformation polymorphism analysis in 60 NIDDM patients. We found 2 missense mutations in exon 3: CCC{r_arrow}CTC (Pro{sup 68}{r_arrow}Leu) in 1 patient and ACT{r_arrow}ATT (Thr{sup 110}{r_arrow}Ile) in 3 patients, all in the heterozygous state. These mutations were found in 60 control subjects. To evaluate the significance of the Pro{sup 68}{r_arrow}Leu mutation, the family members of the proband were studied. The mutation did not appear to be associated with the disease or other clinical parameters including change in immunoreactive insulin/change in plasma glucose or oral glucose load. The other mutation (Thr{sup 110}{r_arrow}Ile) is known to be functionally insignificant. We identified 4 additional nucleotide changes, all of which appeared to be silent. We concluded that the mutations in the GLUT2 gene were not major determinants of genetic susceptibility to NIDDM in Japanese. 34 refs., 2 figs., 3 tabs.

  19. Effect of GLP-1 treatment on GLUT2 and GLUT4 expression in type 1 and type 2 rat diabetic models.

    PubMed

    Villanueva-Peñacarrillo, M L; Puente, J; Redondo, A; Clemente, F; Valverde, I

    2001-07-01

    Glucagon-like peptide-1 (G LP-1) is an incretin with glucose-dependent insulinotropic and insulin-independent antidiabetic properties that exerts insulin-like effects on glucose metabolism in rat liver, skeletal muscle, and fat. This study aimed to search for the effect of a prolonged treatment, 3 ds, with GLP-1 on glucotransporter GLUT2 expression in liver, and on that of GLUT4 in skeletal muscle and fat, in rats. Normal rats and streptozotocin-induced type 1 and type 2 diabetic models were used; diabetic rats were also treated with insulin for comparison. In normal rats, GLP-1 treatment reduced in the three tissues the corresponding glucotransporter protein level, without modifying their mRNA. In the type 2 diabetic model, GLP-1, like insulin, stimulated in liver and fat only the glucotransporter translational process, while in the muscle an effect at the GLUT4 transcriptional level was also observed. In the type 1 diabetic model, GLP-1 apparently exerted in the liver only a posttranslational effect on GLUT2 expression; in muscle and fat, while insulin was shown to have an action on GLUT4 at both transcriptional and translational levels, the effect of GLP-1 was restricted to glucotransporter translation. In normal and diabetic rats, exogenous GLP-1 controlled the glucotransporter expression in extrapancreatic tissues participating in the overall glucose homeostasis-liver, muscle, and fat-where the effect of the peptide seems to be exerted only at the translational and/or posttranslational level; in muscle and fat, the presence of insulin seems to be required for GLP-1 to activate the transcriptional process. The stimulating action of GLP-1 on GLUT2 and GLUT4 expression, mRNA or protein, could be a mechanism by which, at least in part, the peptide exerts its lowering effect on blood glucose. PMID:11720253

  20. Chronic ethanol consumption inhibits glucokinase transcriptional activity by Atf3 and triggers metabolic syndrome in vivo.

    PubMed

    Kim, Ji Yeon; Hwang, Joo-Yeon; Lee, Dae Yeon; Song, Eun Hyun; Park, Keon Jae; Kim, Gyu Hee; Jeong, Eun Ae; Lee, Yoo Jeong; Go, Min Jin; Kim, Dae Jin; Lee, Seong Su; Kim, Bong-Jo; Song, Jihyun; Roh, Gu Seob; Gao, Bin; Kim, Won-Ho

    2014-09-26

    Chronic ethanol consumption induces pancreatic β-cell dysfunction through glucokinase (Gck) nitration and down-regulation, leading to impaired glucose tolerance and insulin resistance, but the underlying mechanism remains largely unknown. Here, we demonstrate that Gck gene expression and promoter activity in pancreatic β-cells were suppressed by chronic ethanol exposure in vivo and in vitro, whereas expression of activating transcription factor 3 (Atf3) and its binding to the putative Atf/Creb site (from -287 to -158 bp) on the Gck promoter were up-regulated. Furthermore, in vitro ethanol-induced Atf3 inhibited the positive effect of Pdx-1 on Gck transcriptional regulation, enhanced recruitment of Hdac1/2 and histone H3 deacetylation, and subsequently augmented the interaction of Hdac1/Pdx-1 on the Gck promoter, which were diminished by Atf3 siRNA. In vivo Atf3-silencing reversed ethanol-mediated Gck down-regulation and β-cell dysfunction, followed by the amelioration of impaired glucose tolerance and insulin resistance. Together, we identified that ethanol-induced Atf3 fosters β-cell dysfunction via Gck down-regulation and that its loss ameliorates metabolic syndrome and could be a potential therapeutic target in treating type 2 diabetes. The Atf3 gene is associated with the induction of type 2 diabetes and alcohol consumption-induced metabolic impairment and thus may be the major negative regulator for glucose homeostasis. PMID:25074928

  1. Nutritional regulation of glucokinase: a cross-species story.

    PubMed

    Panserat, Stéphane; Rideau, Nicole; Polakof, Sergio

    2014-06-01

    The glucokinase (GK) enzyme (EC 2.7.1.1.) is essential for the use of dietary glucose because it is the first enzyme to phosphorylate glucose in excess in different key tissues such as the pancreas and liver. The objective of the present review is not to fully describe the biochemical characteristics and the genetics of this enzyme but to detail its nutritional regulation in different vertebrates from fish to human. Indeed, the present review will describe the existence of the GK enzyme in different animal species that have naturally different levels of carbohydrate in their diets. Thus, some studies have been performed to analyse the nutritional regulation of the GK enzyme in humans and rodents (having high levels of dietary carbohydrates in their diets), in the chicken (moderate level of carbohydrates in its diet) and rainbow trout (no carbohydrate intake in its diet). All these data illustrate the nutritional importance of the GK enzyme irrespective of feeding habits, even in animals known to poorly use dietary carbohydrates (carnivorous species). PMID:24896238

  2. All1371 is a polyphosphate-dependent glucokinase in Anabaena sp. PCC 7120

    PubMed Central

    Klemke, Friederike; Beyer, Gabriele; Sawade, Linda; Saitov, Ali; Korte, Thomas; Maldener, Iris; Lockau, Wolfgang; Nürnberg, Dennis J.

    2014-01-01

    The polyphosphate glucokinases can phosphorylate glucose to glucose 6-phosphate using polyphosphate as the substrate. ORF all1371 encodes a putative polyphosphate glucokinase in the filamentous heterocyst-forming cyanobacterium Anabaena sp. PCC 7120. Here, ORF all1371 was heterologously expressed in Escherichia coli, and its purified product was characterized. Enzyme activity assays revealed that All1371 is an active polyphosphate glucokinase that can phosphorylate both glucose and mannose in the presence of divalent cations in vitro. Unlike many other polyphosphate glucokinases, for which nucleoside triphosphates (e.g. ATP or GTP) act as phosphoryl group donors, All1371 required polyphosphate to confer its enzymic activity. The enzymic reaction catalysed by All1371 followed classical Michaelis–Menten kinetics, with kcat = 48.2 s−1 at pH 7.5 and 28 °C and KM = 1.76 µM and 0.118 mM for polyphosphate and glucose, respectively. Its reaction mechanism was identified as a particular multi-substrate mechanism called the ‘bi-bi ping-pong mechanism’. Bioinformatic analyses revealed numerous polyphosphate-dependent glucokinases in heterocyst-forming cyanobacteria. Viability of an Anabaena sp. PCC 7120 mutant strain lacking all1371 was impaired under nitrogen-fixing conditions. GFP promoter studies indicate expression of all1371 under combined nitrogen deprivation. All1371 might play a substantial role in Anabaena sp. PCC 7120 under these conditions. PMID:25320362

  3. Mutations in the glucokinase gene of the fetus result in reduced birth weight.

    PubMed

    Hattersley, A T; Beards, F; Ballantyne, E; Appleton, M; Harvey, R; Ellard, S

    1998-07-01

    Low birth weight and fetal thinness have been associated with non-insulin dependent diabetes mellitus (NIDDM) and insulin resistance in childhood and adulthood. It has been proposed that this association results from fetal programming in response to the intrauterine environment. An alternative explanation is that the same genetic influences alter both intrauterine growth and adult glucose tolerance. Fetal insulin secretion in response to maternal glycaemia plays a key role in fetal growth, and adult insulin secretion is a primary determinant of glucose tolerance. We hypothesized that a defect in the sensing of glucose by the pancreas, caused by a heterozygous mutation in the glucokinase gene, could reduce fetal growth and birth weight in addition to causing hyperglycaemia after birth. In 58 offspring, where one parent has a glucokinase mutation, the inheritance of a glucokinase mutation by the fetus resulted in a mean reduction of birth weight of 533 g (P=0.002). In 19 of 21 sibpairs discordant for the presence of a glucokinase mutation, the child with the mutation had a lower birth weight, with a mean difference of 521 g (P=0.0002). Maternal hyperglycaemia due to a glucokinase mutation resulted in a mean increase in birth weight of 601 g (P=0.001). The effects of maternal and fetal glucokinase mutations on birth weight were additive. We propose that these changes in birth weight reflect changes in fetal insulin secretion which are influenced directly by the fetal genotype and indirectly, through maternal hyperglycaemia, by the maternal genotype. This observation suggests that variation in fetal growth could be used in the assessment of the role of genes which modify either insulin secretion or insulin action. PMID:9662401

  4. Antidiabetic effects of glucokinase regulatory protein small-molecule disruptors

    NASA Astrophysics Data System (ADS)

    Lloyd, David J.; St Jean, David J.; Kurzeja, Robert J. M.; Wahl, Robert C.; Michelsen, Klaus; Cupples, Rod; Chen, Michelle; Wu, John; Sivits, Glenn; Helmering, Joan; Komorowski, Renée; Ashton, Kate S.; Pennington, Lewis D.; Fotsch, Christopher; Vazir, Mukta; Chen, Kui; Chmait, Samer; Zhang, Jiandong; Liu, Longbin; Norman, Mark H.; Andrews, Kristin L.; Bartberger, Michael D.; van, Gwyneth; Galbreath, Elizabeth J.; Vonderfecht, Steven L.; Wang, Minghan; Jordan, Steven R.; Véniant, Murielle M.; Hale, Clarence

    2013-12-01

    Glucose homeostasis is a vital and complex process, and its disruption can cause hyperglycaemia and type II diabetes mellitus. Glucokinase (GK), a key enzyme that regulates glucose homeostasis, converts glucose to glucose-6-phosphate in pancreatic β-cells, liver hepatocytes, specific hypothalamic neurons, and gut enterocytes. In hepatocytes, GK regulates glucose uptake and glycogen synthesis, suppresses glucose production, and is subject to the endogenous inhibitor GK regulatory protein (GKRP). During fasting, GKRP binds, inactivates and sequesters GK in the nucleus, which removes GK from the gluconeogenic process and prevents a futile cycle of glucose phosphorylation. Compounds that directly hyperactivate GK (GK activators) lower blood glucose levels and are being evaluated clinically as potential therapeutics for the treatment of type II diabetes mellitus. However, initial reports indicate that an increased risk of hypoglycaemia is associated with some GK activators. To mitigate the risk of hypoglycaemia, we sought to increase GK activity by blocking GKRP. Here we describe the identification of two potent small-molecule GK-GKRP disruptors (AMG-1694 and AMG-3969) that normalized blood glucose levels in several rodent models of diabetes. These compounds potently reversed the inhibitory effect of GKRP on GK activity and promoted GK translocation both in vitro (isolated hepatocytes) and in vivo (liver). A co-crystal structure of full-length human GKRP in complex with AMG-1694 revealed a previously unknown binding pocket in GKRP distinct from that of the phosphofructose-binding site. Furthermore, with AMG-1694 and AMG-3969 (but not GK activators), blood glucose lowering was restricted to diabetic and not normoglycaemic animals. These findings exploit a new cellular mechanism for lowering blood glucose levels with reduced potential for hypoglycaemic risk in patients with type II diabetes mellitus.

  5. 5-Alkyl-2-urea-Substituted Pyridines: Identification of Efficacious Glucokinase Activators with Improved Properties.

    PubMed

    Kohn, Todd J; Du, Xiaohui; Lai, SuJen; Xiong, YuMei; Komorowski, Renee; Veniant, Murielle; Fu, Zice; Jiao, Xianyun; Pattaropong, Vatee; Chow, David; Cardozo, Mario; Jin, Lixia; Conn, Marion; DeWolf, Walter E; Kraser, Christopher F; Hinklin, Ronald J; Boys, Mark L; Medina, Julio C; Houze, Jonathan; Dransfield, Paul; Coward, Peter

    2016-07-14

    Two 1-(4-aryl-5-alkyl-pyridin-2-yl)-3-methylurea glucokinase activators were identified with robust in vivo efficacy. These two compounds possessed higher solubilities than the previously identified triaryl compounds (i.e., AM-2394). Structure-activity relationship studies are presented along with relevant pharmacokinetic and in vivo data. PMID:27437074

  6. Glucokinase expression is regulated by glucose through O-GlcNAc glycosylation.

    PubMed

    Baldini, Steffi F; Steenackers, Agata; Olivier-Van Stichelen, Stéphanie; Mir, Anne-Marie; Mortuaire, Marlène; Lefebvre, Tony; Guinez, Céline

    2016-09-16

    Blood glucose fluctuates with the fasting-feeding cycle. One of the liver's functions is to maintain blood glucose concentrations within a physiological range. Glucokinase (GCK) or hexokinase IV, is the main enzyme that regulates the flux and the use of glucose in the liver leading to a compensation of hyperglycemia. In hepatocytes, GCK catalyzes the phosphorylation of glucose into glucose-6-phosphate. This critical enzymatic reaction is determinant for the metabolism of glucose in the liver which includes glycogen synthesis, glycolysis, lipogenesis and gluconeogenesis. In liver, simultaneous increase of glucose and insulin enhances GCK activity and gene expression, changes its subcellular location and interaction with regulatory proteins. The post-translational O-linked β-N-acetylglucosaminylation (O-GlcNAcylation) acts as a glucose-sensitive modification and is believed to take part in hepatic glucose sensing by modifying key regulatory proteins. Therefore, we aimed to determine whether GCK is modified by O-GlcNAcylation in the liver of mice and investigated the role that this modification plays in regulating GCK protein expression. We demonstrated that endogenous GCK expression correlated with O-GlcNAc levels in the pathophysiological model ob/ob mice. More specifically, in response to the pharmacological inhibition of O-GlcNAcase (OGA) contents of GCK increased. Using the GlcNAc specific lectin succinylated-WGA and click chemistry labeling approaches, we demonstrated that GCK is modified by O-GlcNAcylation. Further, we demonstrated that siRNA-mediated Ogt knock-down not only decreases O-GlcNAc content but also GCK protein level. Altogether, our in vivo and in vitro results demonstrate that GCK expression is regulated by nutrient-sensing O-GlcNAc cycling in liver. PMID:27520373

  7. Phosphorylation of D-glucose in Escherichia coli mutants defective in glucosephosphotransferase, mannosephosphotransferase, and glucokinase.

    PubMed Central

    Curtis, S J; Epstein, W

    1975-01-01

    Genetic studies show that Escherichia coli has three enzymes capable of phosphorylating glucose: soluble adenosine 5'-triphosphate-dependent glucokinase, which plays only a minor role in glucose metabolism; an enzyme II, called glucosephosphotransferase, with high specificity for the D-glucose configuration; and another enzyme II, called mannosephosphotransferase, with broader specificity. The former enzyme II is active on glucose and methyl-alpha-glucopyranoside, whereas the latter is active on D-glucose, D-mannose, 2-deoxy-D-glucose, D-glucosamine, and D-mannosamine. Mutations leading to loss of glucosephosphotransferase activity and designated by the symbol gpt are between the purB and pyrC markers in a locus previously called cat. The locus of mutations to loss of mannosephosphotransferase, mpt, is between the eda and fadD genes. Mutations to loss of glucokinase, glk, are between the ptsI and dsd genes. PMID:1097393

  8. A novel functional glucose transporter in the white shrimp Litopenaeus vannamei -LvGLUT2- is up-regulated during hypoxia in hepatopancreas.

    PubMed

    Martínez-Quintana, José A; Kikuta, Shingo; Felix-Portillo, Monserrath; Peregrino-Uriarte, Alma B; Yepiz-Plascencia, Gloria

    2015-12-01

    In hypoxia conditions, the white shrimp Litopenaeus vannamei shifts its energetic metabolism from aerobic to anaerobic, requiring more glucose uptake into the cells by GLUT proteins. We here report a novel glucose transporter in shrimp. The Lvglut2 cDNA is 2473 bp-long containing an ORF of 1458 bp encoding 486 amino acid residues. The deduced protein has the features of a facilitative sugar transporter. The Lvglut2 gene product tagged with GFP was expressed in the cell membrane of Xenopus oocytes. In the same expression system, untagged LvGLUT2 resulted to be a bidirectional glucose transporter that functions moving glucose down its concentration gradient in and out of the cell. Lvglut2 mRNA is expressed in hepatopancreas while in muscle and gills it was not detected. Hypoxia up-regulates the expression of Lvglut2 transcripts in hepatopancreas. These results provide a better understanding of facilitative glucose transporters and gene regulation during hypoxia in crustaceans. PMID:26415036

  9. Evolution of Hepatic Glucose Metabolism: Liver-Specific Glucokinase Deficiency Explained by Parallel Loss of the Gene for Glucokinase Regulatory Protein (GCKR)

    PubMed Central

    Wang, Zhao Yang; Jin, Ling; Tan, Huanran; Irwin, David M.

    2013-01-01

    Background Glucokinase (GCK) plays an important role in the regulation of carbohydrate metabolism. In the liver, phosphorylation of glucose to glucose-6-phosphate by GCK is the first step for both glycolysis and glycogen synthesis. However, some vertebrate species are deficient in GCK activity in the liver, despite containing GCK genes that appear to be compatible with function in their genomes. Glucokinase regulatory protein (GCKR) is the most important post-transcriptional regulator of GCK in the liver; it participates in the modulation of GCK activity and location depending upon changes in glucose levels. In experimental models, loss of GCKR has been shown to associate with reduced hepatic GCK protein levels and activity. Methodology/Principal Findings GCKR genes and GCKR-like sequences were identified in the genomes of all vertebrate species with available genome sequences. The coding sequences of GCKR and GCKR-like genes were identified and aligned; base changes likely to disrupt coding potential or splicing were also identified. Conclusions/Significance GCKR genes could not be found in the genomes of 9 vertebrate species, including all birds. In addition, in multiple mammalian genomes, whereas GCKR-like gene sequences could be identified, these genes could not predict a functional protein. Vertebrate species that were previously reported to be deficient in hepatic GCK activity were found to have deleted (birds and lizard) or mutated (mammals) GCKR genes. Our results suggest that mutation of the GCKR gene leads to hepatic GCK deficiency due to the loss of the stabilizing effect of GCKR. PMID:23573289

  10. Phosphotransferase system-independent glucose utilization in corynebacterium glutamicum by inositol permeases and glucokinases.

    PubMed

    Lindner, Steffen N; Seibold, Gerd M; Henrich, Alexander; Krämer, Reinhard; Wendisch, Volker F

    2011-06-01

    Phosphoenolpyruvate-dependent glucose phosphorylation via the phosphotransferase system (PTS) is the major path of glucose uptake in Corynebacterium glutamicum, but some growth from glucose is retained in the absence of the PTS. The growth defect of a deletion mutant lacking the general PTS component HPr in glucose medium could be overcome by suppressor mutations leading to the high expression of inositol utilization genes or by the addition of inositol to the growth medium if a glucokinase is overproduced simultaneously. PTS-independent glucose uptake was shown to require at least one of the inositol transporters IolT1 and IolT2 as a mutant lacking IolT1, IolT2, and the PTS component HPr could not grow with glucose as the sole carbon source. Efficient glucose utilization in the absence of the PTS necessitated the overexpression of a glucokinase gene in addition to either iolT1 or iolT2. IolT1 and IolT2 are low-affinity glucose permeases with K(s) values of 2.8 and 1.9 mM, respectively. As glucose uptake and phosphorylation via the PTS differs from glucose uptake via IolT1 or IolT2 and phosphorylation via glucokinase by the requirement for phosphoenolpyruvate, the roles of the two pathways for l-lysine production were tested. The l-lysine yield by C. glutamicum DM1729, a rationally engineered l-lysine-producing strain, was lower than that by its PTS-deficient derivate DM1729Δhpr, which, however, showed low production rates. The combined overexpression of iolT1 or iolT2 with ppgK, the gene for PolyP/ATP-dependent glucokinase, in DM1729Δhpr enabled l-lysine production as fast as that by the parent strain DM1729 but with 10 to 20% higher l-lysine yield. PMID:21478323

  11. Novel Series of Potent Glucokinase Activators Leading to the Discovery of AM-2394.

    PubMed

    Dransfield, Paul J; Pattaropong, Vatee; Lai, Sujen; Fu, Zice; Kohn, Todd J; Du, Xiaohui; Cheng, Alan; Xiong, Yumei; Komorowski, Renee; Jin, Lixia; Conn, Marion; Tien, Eric; DeWolf, Walter E; Hinklin, Ronald J; Aicher, Thomas D; Kraser, Christopher F; Boyd, Steven A; Voegtli, Walter C; Condroski, Kevin R; Veniant-Ellison, Murielle; Medina, Julio C; Houze, Jonathan; Coward, Peter

    2016-07-14

    Glucokinase (GK) catalyzes the phosphorylation of glucose to glucose-6-phosphate. We present the structure-activity relationships leading to the discovery of AM-2394, a structurally distinct GKA. AM-2394 activates GK with an EC50 of 60 nM, increases the affinity of GK for glucose by approximately 10-fold, exhibits moderate clearance and good oral bioavailability in multiple animal models, and lowers glucose excursion following an oral glucose tolerance test in an ob/ob mouse model of diabetes. PMID:27437083

  12. Theoretical investigations on the interactions of glucokinase regulatory protein with fructose phosphates.

    PubMed

    Ling, Baoping; Yan, Xueyuan; Sun, Min; Bi, Siwei

    2016-02-01

    Glucokinase (GK) plays a critical role in maintaining glucose homeostasis in the human liver and pancreas. In the liver, the activity of GK is modulated by the glucokinase regulatory protein (GKRP) which functions as a competitive inhibitor of glucose to bind to GK. Moreover, the inhibitory intensity of GKRP-GK is suppressed by fructose 1-phosphate (F1P), and reinforced by fructose 6-phosphate (F6P). Here, we employed a series of computational techniques to explore the interactions of fructose phosphates with GKRP. Calculation results reveal that F1P and F6P can bind to the same active site of GKRP with different binding modes, and electrostatic interaction provides a major driving force for the ligand binding. The presence of fructose phosphate severely influences the motions of protein and the conformational space, and the structural change of sugar phosphate influences its interactions with GKRP, leading to a large conformational rearrangement of loop2 in the SIS2 domain. In particular, the binding of F6P to GKRP facilitates the protruding loop2 contacting with GK to form the stable GK-GKRP complex. The conserved residues 179-184 of GKRP play a major role in the binding of phosphate group and maintaining the stability of GKRP. These results may provide deep insight into the regulatory mechanism of GKRP to the activity of GK. PMID:26629747

  13. Glucokinase regulatory proten genetic variant interacts with omega-3 PUFA to influence insulin resistance and inflammation in metabolic syndrome

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Glucokinase Regulatory Protein (GCKR) plays a central role regulating both hepatic triglyceride and glucose metabolism. Fatty acids are key metabolic regulators, which interact with genetic factors and influence glucose metabolism and other metabolic traits. Omega-3 polyunsaturated fatty acids (n-3...

  14. Relevant associations of the glucokinase regulatory protein/glucokinase gene variation with TAG concentrations in a high-cardiovascular risk population: modulation by the Mediterranean diet.

    PubMed

    Sotos-Prieto, Mercedes; Guillén, Marisa; Vicente Sorli, Jose; Portolés, Olga; Guillem-Saiz, Patricia; Ignacio Gonzalez, Jose; Qi, Lu; Corella, Dolores

    2013-01-28

    The SNP rs1260326 (P446L) and rs1799884 (-30G>A) for the glucokinase regulatory protein (GCKR) and glucokinase (GCK) genes, respectively, have been associated with opposing effects on TAG and glucose concentrations. However, their genetic modulation by diet (dietary patterns or foods) remains to be investigated. We studied 945 high-cardiovascular risk subjects aged 67 (sd 6) years who participated in the PREvención con DIeta MEDiterránea-Valencia Study. Demographic, clinical, biochemical and genetic data were obtained. Adherence to the Mediterranean diet (MD) and food intake were measured by validated questionnaires. Carriers of the L allele of GKCR had significantly higher TAG concentrations (PP: 1.34 (SD 0.05) mmol/l v. PL+LL: 1.54 (SD 0.03) mmol/l; P= 0.014) and LL carriers had lower glucose concentrations (PL+PP: 6.85 (SD 0.08) mmol/l v. LL: 6.40 (SD 0.16) mmol/l; P= 0.032) after multivariate adjustment. Conversely, homozygous subjects for the variant allele (A) in the GCK gene had significantly lower TAG (GG+GA: 1.48 (SD 0.03) mmol/l v. AA: 1.17 (SD 0.18) mmol/l; P= 0.033) and a higher risk of diabetes (OR 3.3, 95 % CI 1.2, 9.2). Combined effects for both SNP increased TAG concentrations by 37 % (P= 0.033). Adherence to the MD modulated the effects of GCKR polymorphism on TAG: subjects with genetic risk had lower TAG (L-allele carriers; PP: 1.48 (SD 0.14) mmol/l v. PL+LL: 1.51 (SD 0.08) mmol/l; P= 0.917) compared with those with a higher adherence. Analysis of the joint effects of the GCKR and individual food items identified significant associations (olive oil (P= 0.035), vegetables (P= 0.012), red meat (P= 0.017), butter (P= 0.039), sweetened carbonated beverages (P= 0.036) and nuts (P= 0.038)). In conclusion, we found that rs1260326 (GCKR) is significantly associated with higher TAG concentrations, but is modulated by adherence to the MD. PMID:22716779

  15. Substrate-induced Nuclear Export and Peripheral Compartmentalization of Hepatic Glucokinase Correlates with Glycogen Deposition

    PubMed Central

    Shiota, Masa; Knobel, Susan M.; Piston, David W.; Cherrington, Alan D.; Magnuson, Mark A.

    2001-01-01

    Hepatic glucokinase (GK) is acutely regulated by binding to its nuclear-anchored regulatory protein (GKRP). Although GK release by GKRP is tightly coupled to the rate of glycogen synthesis, the nature of this association is obscure. To gain insight into this coupling mechanism under physiological stimulating conditions in primary rat hepatocytes, we analyzed the subcellular distribution of GK and GKRP with immunofluorescence, and glycogen deposition with glycogen cytochemical fluorescence, using confocal microscopyand quantitative image analysis. Following stimulation, a fraction of the GK signal translocated from the nucleus to the cytoplasm. The reduction in the nuclear to cytoplasmic ratio of GK, an index of nuclear export, correlated with a >50% increase in glycogen cytochemical fluorescence over a 60min stimulation period. Furthermore, glycogen accumulation was initially deposited in a peripheral pattern in hepatocytes similar to that of GK. These data suggest that a compartmentalization exists of both active GK and the initial sites of glycogen deposition at the hepatocyte surface. PMID:12369705

  16. Features for instantaneous emissions of low-level infrared signals of glucokinase enzyme from Pyrococcus furiosus.

    PubMed

    Torres, Sergio; Mella, Héctor; Reyes, Claudio; Meza, Pablo; Gallardo, Maria J; Staforelli, Juan P

    2015-03-10

    A noncontact infrared (IR) imaging-based methodology and signal recovery tools are applied on an enzyme reaction as a test target. The method is implemented by a long-wave (8-12 μm) IR microbolometer imaging array and a germanium-based IR optical vision. The reaction is carried out by the glucokinase, which produces a rapid exothermal release of energy that is weak, and, even worse, the IR video captured by the uncooled microbolometer detector is affected by spatial and temporal noise with specific complexities. Hitherto, IR-based signal recovery tools have worked with a standard acquisition frequency, which is clearly beyond the time scale of a real scenario. The implications of this (and similar) rapid reactions motivate the designs of a signal recovery method using prior information of the processes to extract and quantify the spontaneity of the enzymatic reaction in a three-dimensional (space and time) single and noncontact online measurement. PMID:25968383

  17. A Fresh View of Glycolysis and Glucokinase Regulation: History and Current Status*

    PubMed Central

    Lenzen, Sigurd

    2014-01-01

    This minireview looks back at a century of glycolysis research with a focus on the mechanisms of flux regulation. Traditionally, glycolysis is regarded as a feeder pathway that prepares glucose for further catabolism and energy production. However, glycolysis is much more than that, in particular in those tissues that express the low affinity glucose-phosphorylating enzyme glucokinase. This enzyme equips the glycolytic pathway with a special steering function for the regulation of intermediary metabolism. In beta cells, glycolysis acts as a transducer for triggering and amplifying physiological glucose-induced insulin secretion. On the basis of these considerations, I have defined a glycolytic flux regulatory unit composed of the two fructose ester steps of this pathway with various enzymes and metabolites that regulate glycolysis. PMID:24637025

  18. Structure of the human glucokinase gene and identification of a missense mutation in a Japanese patient with early-onset non-insulin-dependent diabetes mellitus

    SciTech Connect

    Sakura, Hiroshi; Eto, Kazuhiro; Ueno, Hirohisa; Yazaki, Yoshio; Kadowaki, Takashi ); Kadowaki, Hiroko; Simokawa, Kotaro; Akanuma, Yasuo ); Koda, Naoya; Fukushima, Yoshimitsu )

    1992-12-01

    Glucokinase is thought to play a glucose-sensor role in the pancreas, and abnormalities in its structure, function, and regulation can induce diabetes. The authors isolated the human glucokinase gene, and determined its genomic structure including exon-intron boundaries. Structure of the glucokinase gene in human was very similar to that in rat. Then, by screening Japanese diabetic patients using polymerase chain reaction - single strand conformation polymorphism (PCR-SSCP) and direct-sequencing strategies, they identified a missense mutation substituting ariginine (AGG) for glycine (GGG) at position 261 in exon 7 of the glucokinase gene in a patient with early-onset non-insulin-dependent diabetes (NIDDM). 12 refs., 3 figs., 2 tabs.

  19. Ischemic preconditioning maintains the immunoreactivities of glucokinase and glucokinase regulatory protein in neurons of the gerbil hippocampal CA1 region following transient cerebral ischemia.

    PubMed

    Cho, Young Shin; Cho, Jun Hwi; Shin, Bich-Na; Cho, Geum-Sil; Kim, In Hye; Park, Joon Ha; Ahn, Ji Hyeon; Ohk, Taek Geun; Cho, Byung-Ryul; Kim, Young-Myeong; Hong, Seongkweon; Won, Moo-Ho; Lee, Jae-Chul

    2015-10-01

    Glucokinase (GK) is involved in the control of blood glucose homeostasis. In the present study, the effect of ischemic preconditioning (IPC) on the immunoreactivities of GK and its regulatory protein (GKRP) following 5 min of transient cerebral ischemia was investigated in gerbils. The gerbils were randomly assigned to four groups (sham‑operated group, ischemia‑operated group, IPC + sham‑operated group and IPC + ischemia‑operated group). IPC was induced by subjecting the gerbils to 2 min of ischemia, followed by 1 day of recovery. In the ischemia‑operated group, a significant loss of neurons was observed in the stratum pyramidale (SP) of the hippocampal CA1 region (CA1) at 5 days post‑ischemia; however, in the IPC+ischemia‑operated group, the neurons in the SP were well protected. Following immunohistochemical investigation, the immunoreactivities of GK and GKRP in the neurons of the SP were markedly decreased in the CA1, but not the CA2/3, from 2 days post‑ischemia, and were almost undetectable in the SP 5 days post‑ischemia. In the IPC + ischemia‑operated group, the immunoreactivities of GK and GKRP in the SP of the CA1 were similar to those in the sham‑group. In brief, the findings of the present study demonstrated that IPC notably maintained the immunoreactivities of GK and GKRP in the neurons of the SP of CA1 following ischemia‑reperfusion. This indicated that GK and GKRP may be necessary for neuron survival against transient cerebral ischemia. PMID:26134272

  20. Ischemic preconditioning maintains the immunoreactivities of glucokinase and glucokinase regulatory protein in neurons of the gerbil hippocampal CA1 region following transient cerebral ischemia

    PubMed Central

    CHO, YOUNG SHIN; CHO, JUN HWI; SHIN, BICH-NA; CHO, GEUM-SIL; KIM, IN HYE; PARK, JOON HA; AHN, JI HYEON; OHK, TAEK GEUN; CHO, BYUNG-RYUL; KIM, YOUNG-MYEONG; HONG, SEONGKWEON; WON, MOO-HO; LEE, JAE-CHUL

    2015-01-01

    Glucokinase (GK) is involved in the control of blood glucose homeostasis. In the present study, the effect of ischemic preconditioning (IPC) on the immunoreactivities of GK and its regulatory protein (GKRP) following 5 min of transient cerebral ischemia was investigated in gerbils. The gerbils were randomly assigned to four groups (sham-operated group, ischemia-operated group, IPC + sham-operated group and IPC + ischemia-operated group). IPC was induced by subjecting the gerbils to 2 min of ischemia, followed by 1 day of recovery. In the ischemia-operated group, a significant loss of neurons was observed in the stratum pyramidale (SP) of the hippocampal CA1 region (CA1) at 5 days post-ischemia; however, in the IPC+ischemia-operated group, the neurons in the SP were well protected. Following immunohistochemical investigation, the immunoreactivities of GK and GKRP in the neurons of the SP were markedly decreased in the CA1, but not the CA2/3, from 2 days post-ischemia, and were almost undetectable in the SP 5 days post-ischemia. In the IPC + ischemia-operated group, the immunoreactivities of GK and GKRP in the SP of the CA1 were similar to those in the sham-group. In brief, the findings of the present study demonstrated that IPC notably maintained the immunoreactivities of GK and GKRP in the neurons of the SP of CA1 following ischemia-reperfusion. This indicated that GK and GKRP may be necessary for neuron survival against transient cerebral ischemia. PMID:26134272

  1. Substrate Recognition Mechanism and Substrate-Dependent Conformational Changes of an ROK Family Glucokinase from Streptomyces griseus

    PubMed Central

    Miyazono, Ken-ichi; Tabei, Nobumitsu; Morita, Sho; Ohnishi, Yasuo; Horinouchi, Sueharu

    2012-01-01

    Carbon catabolite repression (CCR) is a widespread phenomenon in many bacteria that is defined as the repression of catabolic enzyme activities for an unfavorable carbon source by the presence of a preferable carbon source. In Streptomyces, secondary metabolite production often is negatively affected by the carbon source, indicating the involvement of CCR in secondary metabolism. Although the CCR mechanism in Streptomyces still is unclear, glucokinase is presumably a central player in CCR. SgGlkA, a glucokinase from S. griseus, belongs to the ROK family glucokinases, which have two consensus sequence motifs (1 and 2). Here, we report the crystal structures of apo-SgGlkA, SgGlkA in complex with glucose, and SgGlkA in complex with glucose and adenylyl imidodiphosphate (AMPPNP), which are the first structures of an ROK family glucokinase. SgGlkA is divided into a small α/β domain and a large α+β domain, and it forms a dimer-of-dimer tetrameric configuration. SgGlkA binds a β-anomer of glucose between the two domains, and His157 in consensus sequence 1 plays an important role in the glucose-binding mechanism and anomer specificity of SgGlkA. In the structures of SgGlkA, His157 forms an HC3-type zinc finger motif with three cysteine residues in consensus sequence 2 to bind a zinc ion, and it forms two hydrogen bonds with the C1 and C2 hydroxyls of glucose. When the three structures are compared, the structure of SgGlkA is found to be modified by the binding of substrates. The substrate-dependent conformational changes of SgGlkA may be related to the CCR mechanism in Streptomyces. PMID:22101842

  2. Onset of carbon catabolite repression in Aspergillus nidulans. Parallel involvement of hexokinase and glucokinase in sugar signaling.

    PubMed

    Flipphi, Michel; van de Vondervoort, Peter J I; Ruijter, George J G; Visser, Jaap; Arst, Herbert N; Felenbok, Béatrice

    2003-04-01

    The role of hexose phosphorylating enzymes in the signaling of carbon catabolite repression was investigated in the filamentous fungus Aspergillus nidulans. A d-fructose non-utilizing, hexokinase-deficient (hxkA1, formerly designated frA1) strain was utilized to obtain new mutants lacking either glucokinase (glkA4) or both hexose kinases (hxkA1/glkA4). d-Glucose and d-fructose phosphorylation is completely abolished in the double mutant, which consequently cannot grow on either sugar. The glucokinase single mutant exhibits no nutritional deficiencies. Three repressible diagnostic systems, ethanol utilization (alcA and alcR genes), xylan degradation (xlnA), and acetate catabolism (facA), were analyzed in these hexose kinase mutants at the transcript level. Transcriptional repression by d-glucose is fully retained in the two single kinase mutants, whereas the hexokinase mutant is partially derepressed for d-fructose. Thus, hexokinase A and glucokinase A compensate each other for carbon catabolite repression by d-glucose in the single mutants. In contrast, both d-glucose and d-fructose repression are severely impaired for all three diagnostic systems in the double mutant. Unlike the situation in Saccharomyces cerevisiae, the hexose phosphorylating enzymes play parallel roles in glucose repression in A. nidulans. PMID:12519784

  3. Cloning, expression and characterization of glucokinase gene involved in the glucose-6- phosphate formation in Staphylococcus aureus

    PubMed Central

    Lakshmi, Hanumanthu Prasanna; Yeswanth, Sthanikam; Prasad, Uppu Venkateswara; Vasu, Dudipeta; Swarupa, Vimjam; Kumar, Pasupuleti Santhosh; Narasu, Mangamoori Lakshmi; Krishna Sarma, Potukuchi Venkata Gurunadha

    2013-01-01

    Glucose-6-phosphate (G-6-P) formation in Staphylococcus aureus is catalysed by glucokinase (glkA) gene under high glucose concentration leading to upregulation of various pathogenic factors; therefore the present study is aimed in the cloning and characterization of glk A gene from S. aureus ATCC12600. The glk A gene was cloned in the Sma I site of pQE 30, sequenced (Accession number: JN645812) and expressed in E. coli DH5α. The recombinant glk A expressed from the resultant glk A 1 clone was purified using nickel metal chelate chromatography, the pure enzyme gave single band in SDS-PAGE with molecular weight of 33kDa. The rglk A showed very high affinity to glucose Km 5.1±0.06mM with Hill coefficient of 1.66±0.032mM. Analysis of glucokinase sequence of S. aureus showed presence of typical ATP binding site and ROK motif CNCGRSGCIE. Sequentially and phylogenetically S. aureus glk A exhibited low identity with other bacterial glk A and 21% homology with human glucokinase (GCK). Functionally, S. aureus glk A showed higher rate of G-6-P formation compared to human GCK which may have profound role in the pathogenesis. PMID:23519063

  4. Overexpression of a glucokinase point mutant in the treatment of diabetes mellitus

    PubMed Central

    Lu, G; Teng, X; Zheng, Z; Zhang, R; Peng, L; Zheng, F; Liu, J; Huang, H; Xiong, H

    2016-01-01

    Glucokinase (GCK) is an important enzyme critical for glucose metabolism, and has been targeted as such in the pursuit of a cure for diabetes mellitus. We show that streptozotocin (STZ)-induced diabetic murine model exhibits low GCK expression with high blood glucose levels; moreover, aggravated glomerulonephritis is observed in the model when there is IL10 deficiency. Although T cells infiltrate into the liver and pancreas in STZ-induced diabetes mice, T helper 1 (Th1) and T helper 17 (Th17) cells decrease significantly with STZ addition in in vitro polarization. Using a mutant GCK gene (GCK 262) with a knocked out cytosine at position 2643 results in lower protein expression and more ubiquitination-led protein degradation compared with wild-type GCK (GCK 261). We further observed that hsa-mir-1302 can bind to 3′-untranslated region of mutant GCK, which can decrease GCK mRNA translation. Finally, delivery of mutant GCK by subcutaneous injection is more effective at decreasing blood glucose in the STZ-treated (STZ) murine diabetes model than insulin treatment alone. Similarly, mutant GCK consistently and moderately decreases blood glucose levels in GK rats over a period of 12 and 70 days without inducing hypoglycemia, whereas insulin is only effective over 12 h. These results suggest that mutant GCK may be a future cure for diabetes. PMID:26752353

  5. Dynamic Localization of Glucokinase and Its Regulatory Protein in Hypothalamic Tanycytes

    PubMed Central

    Ordenes, Patricio; Millán, Carola; Yañez, María José; Llanos, Paula; Villagra, Marcos; Elizondo-Vega, Roberto; Martínez, Fernando; Nualart, Francisco; Uribe, Elena; de los Angeles García-Robles, María

    2014-01-01

    Glucokinase (GK), the hexokinase involved in glucose sensing in pancreatic β cells, is also expressed in hypothalamic tanycytes, which cover the ventricular walls of the basal hypothalamus and are implicated in an indirect control of neuronal activity by glucose. Previously, we demonstrated that GK was preferentially localized in tanycyte nuclei in euglycemic rats, which has been reported in hepatocytes and is suggestive of the presence of the GK regulatory protein, GKRP. In the present study, GK intracellular localization in hypothalamic and hepatic tissues of the same rats under several glycemic conditions was compared using confocal microscopy and Western blot analysis. In the hypothalamus, increased GK nuclear localization was observed in hyperglycemic conditions; however, it was primarily localized in the cytoplasm in hepatic tissue under the same conditions. Both GK and GKRP were next cloned from primary cultures of tanycytes. Expression of GK by Escherichia coli revealed a functional cooperative protein with a S0.5 of 10 mM. GKRP, expressed in Saccharomyces cerevisiae, inhibited GK activity in vitro with a Ki 0.2 µM. We also demonstrated increased nuclear reactivity of both GK and GKRP in response to high glucose concentrations in tanycyte cultures. These data were confirmed using Western blot analysis of nuclear extracts. Results indicate that GK undergoes short-term regulation by nuclear compartmentalization. Thus, in tanycytes, GK can act as a molecular switch to arrest cellular responses to increased glucose. PMID:24739934

  6. Human glucokinase gene: isolation, characterization, and identification of two missense mutations linked to early-onset non-insulin-dependent (type 2) diabetes mellitus.

    PubMed Central

    Stoffel, M; Froguel, P; Takeda, J; Zouali, H; Vionnet, N; Nishi, S; Weber, I T; Harrison, R W; Pilkis, S J; Lesage, S

    1992-01-01

    DNA polymorphisms in the glucokinase gene have recently been shown to be tightly linked to early-onset non-insulin-dependent diabetes mellitus in approximately 80% of French families with this form of diabetes. We previously identified a nonsense mutation in exon 7 in one of these families and showed that it was the likely cause of glucose intolerance in this dominantly inherited disorder. Here we report the isolation and partial sequence of the human glucokinase gene and the identification of two missense mutations in exon 7, Thr-228----Met and Gly-261----Arg, that cosegregate with early-onset non-insulin-dependent diabetes mellitus. To assess the molecular mechanism by which mutations at these two sites may affect glucokinase activity, the crystal structure of the related yeast hexokinase B was used as a simple model for human beta-cell glucokinase. Computer-assisted modeling suggests that mutation of Thr-228 affects affinity for ATP and mutation of Gly-261 may alter glucose binding. The identification of mutations in glucokinase, a protein that plays an important role in hepatic and beta-cell glucose metabolism, indicates that early-onset non-insulin-dependent diabetes mellitus may be primarily a disorder of carbohydrate metabolism. Images PMID:1502186

  7. Structure-based approach to the identification of a novel group of selective glucosamine analogue inhibitors of Trypanosoma cruzi glucokinase.

    PubMed

    D'Antonio, Edward L; Deinema, Mason S; Kearns, Sean P; Frey, Tyler A; Tanghe, Scott; Perry, Kay; Roy, Timothy A; Gracz, Hanna S; Rodriguez, Ana; D'Antonio, Jennifer

    2015-12-01

    Glucokinase and hexokinase from pathogenic protozoa Trypanosoma cruzi are potential drug targets for antiparasitic chemotherapy of Chagas' disease. These glucose kinases phosphorylate d-glucose with co-substrate ATP and yield glucose 6-phosphate and are involved in essential metabolic pathways, such as glycolysis and the pentose phosphate pathway. An inhibitor class was conceived that is selective for T. cruzi glucokinase (TcGlcK) using structure-based drug design involving glucosamine having a linker from the C2 amino that terminates with a hydrophobic group either being phenyl, p-hydroxyphenyl, or dioxobenzo[b]thiophenyl groups. The synthesis and characterization for two of the four compounds are presented while the other two compounds were commercially available. Four high-resolution X-ray crystal structures of TcGlcK inhibitor complexes are reported along with enzyme inhibition constants (Ki) for TcGlcK and Homo sapiens hexokinase IV (HsHxKIV). These glucosamine analogue inhibitors include three strongly selective TcGlcK inhibitors and a fourth inhibitor, benzoyl glucosamine (BENZ-GlcN), which is a similar variant exhibiting a shorter linker. Carboxybenzyl glucosamine (CBZ-GlcN) was found to be the strongest glucokinase inhibitor known to date, having a Ki of 0.71±0.05μM. Also reported are two biologically active inhibitors against in vitro T. cruzi culture that were BENZ-GlcN and CBZ-GlcN, with intracellular amastigote growth inhibition IC50 values of 16.08±0.16μM and 48.73±0.69μM, respectively. These compounds revealed little to no toxicity against mammalian NIH-3T3 fibroblasts and provide a key starting point for further drug development with this class of compound. PMID:26778112

  8. MiR-206 is expressed in pancreatic islets and regulates glucokinase activity

    PubMed Central

    Sachdev, Vinay; Frank, Saša; Graier, Wolfgang F.; Kratky, Dagmar; Kostner, Gerhard M.

    2016-01-01

    Glucose homeostasis is a complex indispensable process, and its dysregulation causes hyperglycemia and type 2 diabetes mellitus. Glucokinase (GK) takes a central role in these pathways and is thus rate limiting for glucose-stimulated insulin secretion (GSIS) from pancreatic islets. Several reports have described the transcriptional regulation of Gck mRNA, whereas its posttranscriptional mechanisms of regulation, especially those involving microRNAs (miR), are poorly understood. In this study, we investigated the role of miR-206 as a posttranscriptional regulator of Gck. In addition, we examined the effects of miR-206 on glucose tolerance, GSIS, and gene expression in control and germ line miR-206 knockout (KO) mice fed either with chow or high-fat diet (HFD). MiR-206 was found in Gck-expressing tissues and was differentially altered in response to HFD feeding. Pancreatic islets showed the most profound induction in the expression of miR-206 in response to HFD. Chow- and HFD-fed miR-206KO mice have improved glucose tolerance and GSIS but unaltered insulin sensitivity. In silico analysis of Gck mRNA revealed a conserved 8-mer miR-206 binding site. Hence, the predicted regulation of Gck by miR-206 was confirmed in reporter and GK activity assays. Concomitant with increased GK activity, miR-206KO mice had elevated liver glycogen content and plasma lactate concentrations. Our findings revealed a novel mechanism of posttranscriptional regulation of Gck by miR-206 and underline the crucial role of pancreatic islet miR-206 in the regulation of whole body glucose homeostasis in a murine model that mimics the metabolic syndrome. PMID:27221121

  9. Glucose- and glucokinase-controlled mal gene expression in Escherichia coli.

    PubMed

    Lengsfeld, Christina; Schönert, Stefan; Dippel, Renate; Boos, Winfried

    2009-02-01

    MalT is the central transcriptional activator of all mal genes in Escherichia coli. Its activity is controlled by the inducer maltotriose. It can be inhibited by the interaction with certain proteins, and its expression can be controlled. We report here a novel aspect of mal gene regulation: the effect of cytoplasmic glucose and glucokinase (Glk) on the activity and the expression of MalT. Amylomaltase (MalQ) is essential for the metabolism of maltose. It forms maltodextrins and glucose from maltose or maltodextrins. We found that glucose above a concentration of 0.1 mM blocked the activity of the enzyme. malQ mutants when grown in the absence of maltodextrins are endogenously induced by maltotriose that is derived from the degradation of glycogen. Therefore, the fact that glk malQ(+) mutants showed elevated mal gene expression finds its explanation in the reduced ability to remove glucose from MalQ-catalyzed maltodextrin formation and is caused by a metabolically induced MalQ(-) phenotype. However, even in mutants lacking glycogen, Glk controls endogenous induction. We found that overexpressed Glk due to its structural similarity with Mlc, the repressor of malT, binds to the glucose transporter (PtsG), releasing Mlc and thus increasing malT repression. In addition, even in mutants lacking Mlc (and glycogen), the overexpression of glk leads to a reduction in mal gene expression. We interpret this repression by a direct interaction of Glk with MalT concomitant with MalT inhibition. This repression was dependent on the presence of either maltodextrin phosphorylase or amylomaltase and led to the inactivation of MalT. PMID:19028900

  10. Regulation of glucokinase activity in liver of hibernating ground squirrel Spermophilus undulatus.

    PubMed

    Khu, L Ya; Storey, K B; Rubtsov, A M; Goncharova, N Yu

    2014-07-01

    The kinetic properties of glucokinase (GLK) from the liver of active and hibernating ground squirrels Spermophilus undulatus have been studied. Entrance of ground squirrels into hibernation from their active state is accompanied by a sharp decrease in blood glucose (Glc) level (from 14 to 2.9 mM) and with a significant (7-fold) decrease of GLK activity in the liver cytoplasm. Preparations of native GLK practically devoid of other molecular forms of hexokinase were obtained from the liver of active and hibernating ground squirrels. The dependence of GLK activity upon Glc concentration for the enzyme from active ground squirrel liver showed a pronounced sigmoid character (Hill coefficient, h=1.70 and S0.5=6.23 mM; the experiments were conducted at 25°C in the presence of enzyme stabilizers, K+ and DTT). The same dependence of enzyme activity on Glc concentration was found for GLK from rat liver. However, on decreasing the temperature to 2°C (simulation of hibernation conditions), this dependency became almost hyperbolic (h=1.16) and GLK affinity for substrate was reduced (S0.5=23 mM). These parameters for hibernating ground squirrels (body temperature 5°C) at 25°C were found to be practically equal to the corresponding values obtained for GLK from the liver of active animals (h=1.60, S0.5=9.0 mM, respectively); at 2°C sigmoid character was less expressed and affinity for Glc was drastically decreased (h=1.20, S0.5=45 mM). The calculations of GLK activity in the liver of hibernating ground squirrels based on enzyme kinetic characteristics and seasonal changes in blood Glc concentrations have shown that GLK activity in the liver of hibernating ground squirrels is decreased about 5500-fold. PMID:25108335

  11. Lactose metabolism in Streptococcus lactis: studies with a mutant lacking glucokinase and mannose-phosphotransferase activities

    SciTech Connect

    Thompson, J.; Chassy, B.M.; Egan, W.

    1985-04-01

    A mutant of Streptococcus lactis 133 has been isolated that lacks both glucokinase and phosphoenolpyruvate-dependent mannose- phosphotransferase (mannose-PTS) activities. The double mutant S. lactis 133 mannose-PTSd GK- is unable to utilize either exogenously supplied or intracellularly generated glucose for growth. Fluorographic analyses of metabolites formed during the metabolism of (/sup 14/C)lactose labeled specifically in the glucose or galactosyl moiety established that the cells were unable to phosphorylate intracellular glucose. However, cells of S. lactis 133 mannose-PTSd GK- readily metabolized intracellular glucose 6-phosphate, and the growth rates and cell yield of the mutant and parental strains on sucrose were the same. During growth on lactose, S. lactis 133 mannose-PTSd GK- fermented only the galactose moiety of the disaccharide, and 1 mol of glucose was generated per mol of lactose consumed. For an equivalent concentration of lactose, the cell yield of the mutant was 50% that of the wild type. The specific rate of lactose utilization by growing cells of S. lactis 133 mannose-PTSd GK- was ca. 50% greater than that of the wild type, but the cell doubling times were 70 and 47 min, respectively. High-resolution /sup 31/P nuclear magnetic resonance studies of lactose transport by starved cells of S. lactis 133 and S. lactis 133 mannose-PTSd GK- showed that the latter cells contained elevated lactose-PTS activity. Throughout exponential growth on lactose, the mutant maintained an intracellular steady-state glucose concentration of 100 mM.

  12. Role of connecting loop I in catalysis and allosteric regulation of human glucokinase

    PubMed Central

    Martinez, Juliana A; Larion, Mioara; Conejo, Maria S; Porter, Carol M; Miller, Brian G

    2014-01-01

    Glucokinase (GCK, hexokinase IV) is a monomeric enzyme with a single glucose binding site that displays steady-state kinetic cooperativity, a functional characteristic that affords allosteric regulation of GCK activity. Structural evidence suggests that connecting loop I, comprised of residues 47–71, facilitates cooperativity by dictating the rate and scope of motions between the large and small domains of GCK. Here we investigate the impact of varying the length and amino acid sequence of connecting loop I upon GCK cooperativity. We find that sequential, single amino acid deletions from the C-terminus of connecting loop I cause systematic decreases in cooperativity. Deleting up to two loop residues leaves the kcat value unchanged; however, removing three or more residues reduces kcat by 1000-fold. In contrast, the glucose K0.5 and KD values are unaffected by shortening the connecting loop by up to six residues. Substituting alanine or glycine for proline-66, which adopts a cis conformation in some GCK crystal structures, does not alter cooperativity, indicating that cis/trans isomerization of this loop residue does not govern slow conformational reorganizations linked to hysteresis. Replacing connecting loop I with the corresponding loop sequence from the catalytic domain of the noncooperative isozyme human hexokinase I (HK-I) eliminates cooperativity without impacting the kcat and glucose K0.5 values. Our results indicate that catalytic turnover requires a minimal length of connecting loop I, whereas the loop has little impact upon the binding affinity of GCK for glucose. We propose a model in which the primary structure of connecting loop I affects cooperativity by influencing conformational dynamics, without altering the equilibrium distribution of GCK conformations. PMID:24723372

  13. Role of connecting loop I in catalysis and allosteric regulation of human glucokinase.

    PubMed

    Martinez, Juliana A; Larion, Mioara; Conejo, Maria S; Porter, Carol M; Miller, Brian G

    2014-07-01

    Glucokinase (GCK, hexokinase IV) is a monomeric enzyme with a single glucose binding site that displays steady-state kinetic cooperativity, a functional characteristic that affords allosteric regulation of GCK activity. Structural evidence suggests that connecting loop I, comprised of residues 47-71, facilitates cooperativity by dictating the rate and scope of motions between the large and small domains of GCK. Here we investigate the impact of varying the length and amino acid sequence of connecting loop I upon GCK cooperativity. We find that sequential, single amino acid deletions from the C-terminus of connecting loop I cause systematic decreases in cooperativity. Deleting up to two loop residues leaves the kcat value unchanged; however, removing three or more residues reduces kcat by 1000-fold. In contrast, the glucose K0.5 and KD values are unaffected by shortening the connecting loop by up to six residues. Substituting alanine or glycine for proline-66, which adopts a cis conformation in some GCK crystal structures, does not alter cooperativity, indicating that cis/trans isomerization of this loop residue does not govern slow conformational reorganizations linked to hysteresis. Replacing connecting loop I with the corresponding loop sequence from the catalytic domain of the noncooperative isozyme human hexokinase I (HK-I) eliminates cooperativity without impacting the kcat and glucose K0.5 values. Our results indicate that catalytic turnover requires a minimal length of connecting loop I, whereas the loop has little impact upon the binding affinity of GCK for glucose. We propose a model in which the primary structure of connecting loop I affects cooperativity by influencing conformational dynamics, without altering the equilibrium distribution of GCK conformations. PMID:24723372

  14. Design and Synthesis of Acetylenyl Benzamide Derivatives as Novel Glucokinase Activators for the Treatment of T2DM

    PubMed Central

    2015-01-01

    Novel acetylenyl-containing benzamide derivatives were synthesized and screened using an in vitro assay measuring increases in glucokinase activity stimulated by 10 mM glucose concentration and glucose uptake in rat hepatocytes. Lead optimization of an acetylenyl benzamide series led to the discovery of several active compounds via in vitro enzyme assays (EC50 < 40 nM) and in vivo OGTT assays (AUC reduction > 40% at 50 mg/kg). Of the active compounds tested, 3-(3-amino-phenylethynyl)-5-(2-methoxy-1-methyl-ethoxy)-N-(1-methyl-1H-pyrazol-3-yl)-benzamide (19) was identified as a potent glucokinase activator exhibiting an EC50 of 27 nM and eliciting a 2.16-fold increase in glucose uptake. Compound 19 caused a glucose AUC reduction of 47.4% (30 mg/kg) in an OGTT study in C57BL/6J mice compared to 22.6% for sitagliptin (30 mg/kg). Single treatment of the compound 19 in C57BL/6J mice elicited basal glucose lowering activity without any significant evidence for hypoglycemia risk. Compound 19 was therefore selected as a candidate for further preclinical development for the treatment of type 2 diabetes. PMID:25815149

  15. A Common Missense Variant in the Glucokinase Regulatory Protein Gene (GCKR) Is Associated with Increased Plasma Triglyceride and C-Reactive Protein but Lower Fasting Glucose Concentrations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    OBJECTIVE-Using the genome-wide-association approach, we recently identified the glucokinase regulatory protein gene (GCKR, rs780094) region as a novel quantitative trait locus for plasma triglyceride concentration in Europeans. Here, we sought to study the association of GCKR variants with metaboli...

  16. Association between glucokinase regulatory protein (GCKR) and apolipoprotein A5 (APOA5) gene polymorphisms and triacylglycerol concentrations in fasting, postprandial, and fenofibrate-treated states

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Hypertriglyceridemia is a risk factor for cardiovascular disease. Variation in the apolipoprotein A5 (APOA5) and glucokinase regulatory protein (GCKR) genes has been associated with fasting plasma triacylglycerol. Objective: We investigated the combined effects of the GCKR rs780094C-->T,...

  17. Cloning and characterization of glucokinase from a methylotrophic yeast Hansenula polymorpha: different effects on glucose repression in H. polymorpha and Saccharomyces cerevisiae.

    PubMed

    Laht, Silja; Karp, Helen; Kotka, Pille; Järviste, Aiki; Alamäe, Tiina

    2002-08-21

    Glucokinase gene (HPGLK1) was cloned from a methylotrophic yeast Hansenula polymorpha by complementation of glucose-phosphorylation deficiency in a H. polymorpha double kinase-negative mutant A31-10 by a genomic library. An open reading frame of 1416 nt encoding a 471-amino-acid protein with calculated molecular weight 51.6 kDa was characterized in the genomic insert of the plasmid pH3. The protein sequence deduced from HPGLK1 exhibited 55 and 46% identity with glucokinases from Saccharomyces cerevisiae and Aspergillus niger, respectively. The enzyme phosphorylated glucose, mannose and 2-deoxyglucose, but not fructose. Transformation of HPGLK1 into A31-10 restored glucose repression of alcohol oxidase and catalase in the mutant. Transformation of HPGLK1 into S. cerevisiae triple kinase-negative mutant DFY632 showed that H. polymorpha glucokinase cannot transmit the glucose repression signal in S. CEREVSIAE: synthesis of invertase and maltase in respective transformants was insensitive to glucose repression similarly to S. cerevisiae DFY568 possessing only glucokinase. PMID:12383517

  18. Characterization of the heterozygous glucokinase knockout mouse as a translational disease model for glucose control in type 2 diabetes

    PubMed Central

    Baker, D J; Atkinson, A M; Wilkinson, G P; Coope, G J; Charles, A D; Leighton, B

    2014-01-01

    Background and Purpose The global heterozygous glucokinase (GK) knockout (gkwt/del) male mouse, fed on a high-fat (60% by energy) diet, has provided a robust and reproducible model of hyperglycaemia. This model could be highly relevant to some facets of human type 2 diabetes (T2D). We aimed to investigate the ability of standard therapeutic agents to lower blood glucose at translational doses, and to explore the glucose-lowering potential of novel glucokinase activators (GKAs) in this model. Experimental Approach We measured the ability of insulin, metformin, glipizide, exendin-4 and sitagliptin, after acute or repeat dose administration, to lower free-feeding glucose levels in gkwt/del mice. Further, we measured the ability of novel GKAs, GKA23, GKA71 and AZD6370 to control glucose either alone or in combination with some standard agents. Key Results A single dose of insulin (1 unit·kg−1), metformin (150, 300 mg·kg−1), glipizide (0.1, 0.3 mg·kg−1), exendin-4 (2, 20 μg·kg−1) and GKAs reduced free-feeding glucose levels. Sitagliptin (10 mg·kg−1), metformin (300 mg·kg−1) and AZD6370 (30, 400 mg·kg−1) reduced glucose excursions on repeat dosing. At a supra-therapeutic dose (400 mg·kg−1), AZD6370 also lowered basal levels of glucose without inducing hypoglycaemia. Conclusion and Implications Standard glucose-lowering therapeutic agents demonstrated significant acute glucose lowering in male gkwt/del mice at doses corresponding to therapeutic free drug levels in man, suggesting the potential of these mice as a translatable model of human T2D. Novel GKAs also lowered glucose in this mouse model. PMID:24772483

  19. Low glucokinase activity and high rates of gluconeogenesis contribute to hyperglycemia in barn owls (Tyto alba) after a glucose challenge.

    PubMed

    Myers, M R; Klasing, K C

    1999-10-01

    Barn owls (Tyto alba) and leghorn chickens were fed a low protein high glucose (33.44% protein, 23.67% glucose) or a high protein low glucose (55.35% protein, 1.5% glucose) diet. After an intravenous glucose infusion, the peak in plasma glucose was not affected by diet in either species and was 22.6 and 39.4 mmol/L in chickens and barn owls, respectively. Glucose levels returned to normal within 30 min in chickens, but remained elevated for 3.5 h in barn owls. An oral glucose challenge also resulted in greater and longer hyperglycemia in barn owls than in chickens. The activities of hepatic glucokinase, malic enzyme and phosphoenolpyruvate carboxykinase of barn owls were 16, 35, and 333% of the levels in chickens. Malic enzyme (P = 0.024) was less affected by dietary glucose level in barn owls than in chickens. Cultured hepatocytes from chickens produced 43% more glucose from lactate than hepatocytes from barn owls and, conversely, barn owl hepatocytes produced 87% more glucose from threonine than chickens (P = 0.001). Gluconeogenesis from lactate was greatly suppressed by high media glucose in chicken hepatocytes but not in those of barn owls (P = 0.0001 for species by glucose level interaction). When threonine was the substrate, gluconeogenesis was suppressed by increased glucose in both species but to a greater relative extent in chickens (P = 0.007 for species by glucose level interaction). Owls were glucose intolerant at least in part because of low hepatic glucokinase activity and an inadequate suppression of gluconeogenesis in the presence of exogenous glucose, apparently because they evolved with large excesses of amino acids and limited glucose in their normal diet. PMID:10498765

  20. Evidence for the Presence of Glucosensor Mechanisms Not Dependent on Glucokinase in Hypothalamus and Hindbrain of Rainbow Trout (Oncorhynchus mykiss).

    PubMed

    Otero-Rodiño, Cristina; Librán-Pérez, Marta; Velasco, Cristina; López-Patiño, Marcos A; Míguez, Jesús M; Soengas, José L

    2015-01-01

    We hypothesize that glucosensor mechanisms other than that mediated by glucokinase (GK) operate in hypothalamus and hindbrain of the carnivorous fish species rainbow trout and stress affected them. Therefore, we evaluated in these areas changes in parameters which could be related to putative glucosensor mechanisms based on liver X receptor (LXR), mitochondrial activity, sweet taste receptor, and sodium/glucose co-transporter 1 (SGLT-1) 6 h after intraperitoneal injection of 5 mL x Kg(-1) of saline solution alone (normoglycaemic treatment) or containing insulin (hypoglycaemic treatment, 4 mg bovine insulin x Kg(-1) body mass), or D-glucose (hyperglycaemic treatment, 500 mg x Kg(-1) body mass). Half of tanks were kept at a 10 Kg fish mass x m(-3) and denoted as fish under normal stocking density (NSD) whereas the remaining tanks were kept at a stressful high stocking density (70 kg fish mass x m(-3)) denoted as HSD. The results obtained in non-stressed rainbow trout provide evidence, for the first time in fish, that manipulation of glucose levels induce changes in parameters which could be related to putative glucosensor systems based on LXR, mitochondrial activity and sweet taste receptor in hypothalamus, and a system based on SGLT-1 in hindbrain. Stress altered the response of parameters related to these systems to changes in glycaemia. PMID:25996158

  1. Cloning and characterization of the mouse glucokinase gene locus and identification of distal liver-specific DNase I hypersensitive sites

    SciTech Connect

    Postic, C.; Niswender, K.D.; Shelton, K.D.; Pettepher, C.C.; Granner, D.K.; Magnuson, M.A.

    1995-10-10

    We cloned and characterized an 83-kb fragment of mouse genomic DNA containing the entire glucokinase (GK) gene. The 11 exons of the gene span a total distance of 49 kb, with exons 1{beta} and 1L being separated by 35 kb. A total of 25,266 bp of DNA sequence information was determined: from {approximately}-9.2 to {approximately}+15 kb (24,195 bp), relative to the hepatocyte transcription start site, and from -335 to -736 bp (1071 bp), relative to the transcription start site in {beta} cells. These sequences revealed that mouse GK is >94% identical to rat and human GK. Mouse hepatic GK mRNA is regulated by fasting and refeeding, as also occurs in the rat. Alignment of the upstream and downstream promoter regions of the mouse, rat, and human genes revealed several evolutionarily conserved regions that may contribute to transcriptional regulation. However, fusion gene studies in transgenic mice indicate that the conserved regions near the transcription start site in hepatocytes are themselves not sufficient for position-independent expression in liver. Analysis of the chromatin structure of a 48-kb region of the mouse gene using DNase I revealed eight liver-specific hypersensitive sites whose locations ranged from 0.1 to 36 kb upstream of the liver transcription start site. The availability of a single, contiguous DNA fragment containing the entire mouse GK gene should allow further studies of cell-specific expression of GK to be performed. 46 refs., 8 figs.

  2. Effects of a glucokinase activator on hepatic intermediary metabolism: study with 13C-isotopomer-based metabolomics

    PubMed Central

    Nissim, Itzhak; Horyn, Oksana; Nissim, Ilana; Daikhin, Yevgeny; Wehrli, Suzanne L.; Yudkoff, Marc; Matschinsky, Franz M.

    2013-01-01

    GKAs (glucokinase activators) are promising agents for the therapy of Type 2 diabetes, but little is known about their effects on hepatic intermediary metabolism. We monitored the fate of 13C-labelled glucose in both a liver perfusion system and isolated hepatocytes. MS and NMR spectroscopy were deployed to measure isotopic enrichment. The results demonstrate that the stimulation of glycolysis by GKA led to numerous changes in hepatic metabolism: (i) augmented flux through the TCA (tricarboxylic acid) cycle, as evidenced by greater incorporation of 13C into the cycle (anaplerosis) and increased generation of 13C isotopomers of citrate, glutamate and aspartate (cataplerosis); (ii) lowering of hepatic [Pi] and elevated [ATP], denoting greater phosphorylation potential and energy state; (iii) stimulation of glycogen synthesis from glucose, but inhibition of glycogen synthesis from 3-carbon precursors; (iv) increased synthesis of N-acetylglutamate and consequently augmented ureagenesis; (v) increased synthesis of glutamine, alanine, serine and glycine; and (vi) increased production and outflow of lactate. The present study provides a deeper insight into the hepatic actions of GKAs and uncovers the potential benefits and risks of GKA for treatment of diabetes. GKA improved hepatic bioenergetics, ureagenesis and glycogenesis, but decreased gluconeogenesis with a potential risk of lactic acidosis and fatty liver. PMID:22448977

  3. Studies on recombinant glucokinase (r-glk) protein of Brucella abortus as a candidate vaccine molecule for brucellosis.

    PubMed

    Vrushabhendrappa; Singh, Amit Kumar; Balakrishna, Konduru; Sripathy, Murali Harishchandra; Batra, Harsh Vardhan

    2014-09-29

    Brucellosis is one of the most prevalent zoonotic diseases of worldwide distribution caused by the infection of genus Brucella. Live attenuated vaccines such as B. abortus S19, B. abortus RB51 and B. melitensis Rev1 are found most effective against brucellosis infection in animals, contriving a number of serious side effects and having chances to revert back into their active pathogenic form. In order to engineer a safe and effective vaccine candidate to be used in both animals and human, a recombinant subunit vaccine molecule comprising the truncated region of glucokinase (r-glk) gene from B. abortus S19 was cloned and expressed in Escherichia coli BL21DE3 host. Female BALB/c mice immunized with purified recombinant protein developed specific antibody titer of 1:64,000. The predominant IgG2a and IgG2b isotypes signified development of Th1 directed immune responses. In vitro cell cytotoxicity assay using anti-r-glk antibodies incubated with HeLa cells showed 81.20% and 78.5% cell viability against lethal challenge of B. abortus 544 and B. melitensis 16M, respectively. The lymphocyte proliferative assay indicated a higher splenic lymphocyte responses at 25μg/ml concentration of protein which implies the elevated development of memory immune responses. In contrast to control, the immunized group of mice intra-peritoneal (I.P.) challenged with B. abortus 544 were significantly protected with no signs of necrosis and vacuolization in their liver and spleen tissue. The elevated B-cell response associated with Th1 adopted immunity, significant in vitro cell viability as well as protection afforded in experimental animals after challenge, supplemented with histopathological analysis are suggestive of r-glk protein as a prospective candidate vaccine molecule against brucellosis. PMID:25131740

  4. Identification of 21 novel glucokinase (GCK) mutations in UK and European Caucasians with maturity-onset diabetes of the young (MODY).

    PubMed

    Thomson, K L; Gloyn, A L; Colclough, K; Batten, M; Allen, L I S; Beards, F; Hattersley, A T; Ellard, S

    2003-11-01

    Maturity-onset diabetes of the young (MODY) resulting from mutations in the glucokinase (GCK) gene accounts for approximately 20% of MODY in the UK. We have performed fluorescent single stranded conformation polymorphism (F-SSCP) analysis or direct sequencing of the GCK gene in 212 patients referred as part of a research cohort or for diagnostic molecular genetic testing. Mutation screening has identified 43 different mutations in 61 individuals, of which 21 are novel. This report details the mutations identified and their associated clinical features. PMID:14517956

  5. Post-prandial regulation of hepatic glucokinase and lipogenesis requires the activation of TORC1 signalling in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Dai, Weiwei; Panserat, Stéphane; Mennigen, Jan A; Terrier, Frédéric; Dias, Karine; Seiliez, Iban; Skiba-Cassy, Sandrine

    2013-12-01

    To assess the potential involvement of TORC1 (target of rapamycin complex 1) signalling in the regulation of post-prandial hepatic lipid and glucose metabolism-related gene expression in trout, we employed intraperitoneal administration of rapamycin to achieve an acute inhibition of the TOR pathway. Our results reveal that rapamycin inhibits the phosphorylation of TORC1 and its downstream effectors (S6K1, S6 and 4E-BP1), without affecting Akt and the Akt substrates Forkhead-box Class O1 (FoxO1) and glycogen synthase kinase 3α/β (GSK 3α/β). These results indicate that acute administration of rapamycin in trout leads to the inhibition of TORC1 activation. No effect is observed on the expression of genes involved in gluconeogenesis, glycolysis and fatty acid oxidation, but hepatic TORC1 inhibition results in decreased sterol regulatory element binding protein 1c (SREBP1c) gene expression and suppressed fatty acid synthase (FAS) and glucokinase (GK) at gene expression and activity levels, indicating that FAS and GK activity is controlled at a transcriptional level in a TORC1-dependent manner. This study demonstrates for the first time in fish that post-prandial regulation of hepatic lipogenesis and glucokinase in rainbow trout requires the activation of TORC1 signalling. PMID:24031053

  6. Toward a unified model of passive drug permeation II: the physiochemical determinants of unbound tissue distribution with applications to the design of hepatoselective glucokinase activators.

    PubMed

    Ghosh, Avijit; Maurer, Tristan S; Litchfield, John; Varma, Manthema V; Rotter, Charles; Scialis, Renato; Feng, Bo; Tu, Meihua; Guimaraes, Cris R W; Scott, Dennis O

    2014-10-01

    In this work, we leverage a mathematical model of the underlying physiochemical properties of tissues and physicochemical properties of molecules to support the development of hepatoselective glucokinase activators. Passive distribution is modeled via a Fick-Nernst-Planck approach, using in vitro experimental data to estimate the permeability of both ionized and neutral species. The model accounts for pH and electrochemical potential across cellular membranes, ionization according to Henderson-Hasselbalch, passive permeation of the neutral species using Fick's law, and passive permeation of the ionized species using the Nernst-Planck equation. The mathematical model of the physiochemical system allows derivation of a single set of parameters governing the distribution of drug molecules across multiple conditions both in vitro and in vivo. A case study using this approach in the development of hepatoselective glucokinase activators via organic anion-transporting polypeptide-mediated hepatic uptake and impaired passive distribution to the pancreas is described. The results for these molecules indicate the permeability penalty of the ionized form is offset by its relative abundance, leading to passive pancreatic exclusion according to the Nernst-Planck extension of Fickian passive permeation. Generally, this model serves as a useful construct for drug discovery scientists to understand subcellular exposure of acids or bases using specific physiochemical properties. PMID:25024402

  7. Use of alpha-toxin from Staphylococcus aureus to test for channelling of intermediates of glycolysis between glucokinase and aldolase in hepatocytes.

    PubMed

    Cascante, M; Centelles, J J; Agius, L

    2000-12-15

    We investigated whether hepatocytes permeabilized with alpha-toxin from Staphylococcus aureus are a valid model for studying the channelling of intermediates of glycolysis between glucokinase and triosephosphate isomerase. These cells are permeable to 2-aminoisobutyrate, ATP, glucose 6-phosphate (Glc6P) and fructose 2, 6-bisphosphate [Fru(2,6)P(2)], but maintain cell integrity in the presence of ATP as judged by the retention of cytoplasmic enzymes. During incubation with 25 mM glucose, an ATP-generating system and saturating concentrations of Fru(2,6)P(2), rates of detritiation of [2-(3)H]glucose and [3-(3)H]glucose were similar. Exogenous Glc6P (1 mM) and to a lesser extent fructose 6-phosphate, but not Fru(1, 6)P(2), decreased the rate of detritiation of [3-(3)H]glucose. During incubation with 25 mM glucose and Glc6P (0.2-1 mM), with either [3-(3)H]glucose or [3-(3)H]Glc6P as labelled substrate, there was dilution of metabolism of [3-(3)H]glucose with increasing Glc6P but no overall increase in glycolytic flux from glucose and Glc6P, indicating that glycolysis is apparently saturated with Glc6P despite the permeability of the cells to this metabolite. These findings could be explained by partial channelling of Glc6P between glucokinase and glycolysis in the presence of saturating concentrations of Fru(2,6)P(2). They provide an alternative explanation for the concept that there is more than one Glc6P pool. PMID:11104701

  8. Functional Characterization of MODY2 Mutations Highlights the Importance of the Fine-Tuning of Glucokinase and Its Role in Glucose Sensing

    PubMed Central

    García-Herrero, Carmen-María; Rubio-Cabezas, Oscar; Azriel, Sharona; Gutierrez-Nogués, Angel; Aragonés, Angel; Vincent, Olivier; Campos-Barros, Angel; Argente, Jesús; Navas, María-Angeles

    2012-01-01

    Glucokinase (GK) acts as a glucose sensor in the pancreatic beta-cell and regulates insulin secretion. Heterozygous mutations in the human GK-encoding GCK gene that reduce the activity index increase the glucose-stimulated insulin secretion threshold and cause familial, mild fasting hyperglycaemia, also known as Maturity Onset Diabetes of the Young type 2 (MODY2). Here we describe the biochemical characterization of five missense GK mutations: p.Ile130Thr, p.Asp205His, p.Gly223Ser, p.His416Arg and p.Ala449Thr. The enzymatic analysis of the corresponding bacterially expressed GST-GK mutant proteins show that all of them impair the kinetic characteristics of the enzyme. In keeping with their position within the protein, mutations p.Ile130Thr, p.Asp205His, p.Gly223Ser, and p.His416Arg strongly decrease the activity index of GK, affecting to one or more kinetic parameters. In contrast, the p.Ala449Thr mutation, which is located in the allosteric activator site, does not affect significantly the activity index of GK, but dramatically modifies the main kinetic parameters responsible for the function of this enzyme as a glucose sensor. The reduced Kcat of the mutant (3.21±0.28 s−1 vs 47.86±2.78 s−1) is balanced by an increased glucose affinity (S0.5 = 1.33±0.08 mM vs 7.86±0.09 mM) and loss of cooperativity for this substrate. We further studied the mechanism by which this mutation impaired GK kinetics by measuring the differential effects of several competitive inhibitors and one allosteric activator on the mutant protein. Our results suggest that this mutation alters the equilibrium between the conformational states of glucokinase and highlights the importance of the fine-tuning of GK and its role in glucose sensing. PMID:22291974

  9. Importance of glucokinase −258G/A polymorphism in Asian Indians with post-transplant and type 2 diabetes mellitus

    PubMed Central

    Khan, Imran Ali; Vattam, Kiran Kumar; Jahan, Parveen; Hasan, Qurratulain; Rao, Pragna

    2016-01-01

    Summary Type 2 diabetes mellitus (T2DM) and post-transplant diabetes mellitus (PTDM) are non-synonymous forms of diabetes. Glucokinase (GCK) plays a key role in glucose metabolism. The relationship between the GCK promoter and specific types of diabetes, such as PTDM and T2DM, in the Asian Indian population is unknown. We examined the occurrence of a specific GCK promoter variant (−258G/A) in patients with T2DM and PTDM. The case-control study enrolled 640 Asian Indian subjects, including controls (n = 250) and T2DM (n = 250), PTDM (n = 42), and non-post-transplant diabetes mellitus (non-PTDM) (n = 98) patients. Purified Deoxyribonucleic acid (DNA) was genotyped with the polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis. The digested PCR products were analyzed on 12% polyacrylamide gels. The anthropometric, biochemical, and clinical details of each group were documented. GCK −258G/A alleles and genotypes were not associated with T2DM. However, among PTDM subjects, we detected a higher frequency of heterozygotes (52.4%) and a positive association with alleles/genotypes. The results suggest that the promoter region (−258G/A) of GCK plays an important role in PTDM in Asian Indians. PMID:26989645

  10. Doubling the referral rate of monogenic diabetes through a nationwide information campaign--update on glucokinase gene mutations in a Polish cohort.

    PubMed

    Borowiec, M; Fendler, W; Antosik, K; Baranowska, A; Gnys, P; Zmyslowska, A; Malecki, M; Mlynarski, W

    2012-12-01

    In order to improve recruitment efficiency of patients with monogenic diabetes in Poland, in September 2010 a nationwide advertising campaign was launched to inform multiple target groups interested or participating in pediatric diabetologic care. Promotional actions aimed at informing physicians, patients, parents and educators were carried out through nationwide newspapers, medical and patient-developed websites and educational conference presentations. Recruitment efficiency was compared between September 2010 (publication of the first report on project's results) and the following 12 months. The number of families and patients referred to genetic screening was increased by 92% and 96% respectively nearly reaching the numbers recruited throughout the initial 4 years of the project. Participation of non-academic centers was also significantly increased from 2.3% to 7.5% (p = 0.0005). DNA sequencing and Multiplex Ligation-dependant Probe Amplification of the glucokinase gene resulted in finding 50 different mutations. Among those mutations, 19 were novel variants, which included: 17 missense mutations (predicted to be pathogenic according to bioinformatic analysis), 1 nonsense mutation and 1 mutation affecting a consensus intronic splice site. Advertising actions directed at increasing recruitment efficiency are a powerful and possibly neglected tool in screening for rare genetic disorders with a clinically defined phenotype. PMID:22035297

  11. Production of a mouse strain with impaired glucose tolerance by systemic heterozygous knockout of the glucokinase gene and its feasibility as a prediabetes model

    PubMed Central

    SAITO, Mikako; KANEDA, Asako; SUGIYAMA, Tae; IIDA, Ryousuke; OTOKUNI, Keiko; KABURAGI, Misako; MATSUOKA, Hideaki

    2015-01-01

    Exon II of glucokinase (Gk) was deleted to produce a systemic heterozygous Gk knockout (Gk+/−) mouse. The relative expression levels of Gk in the heart, lung, liver, stomach, and pancreas in Gk+/− mice ranged from 0.41–0.68 versus that in wild (Gk+/+) mice. On the other hand, its expression levels in the brain, adipose tissue, and muscle ranged from 0.95–1.03, and its expression levels in the spleen and kidney were nearly zero. Gk knockout caused no remarkable off-target effect on the expression of 7 diabetes causing genes (Shp, Hnf1a, Hnf1b, Irs1, Irs2, Kir6.2, and Pdx1) in 10 organs. The glucose tolerance test was conducted to determine the blood glucose concentrations just after fasting for 24 h (FBG) and at 2 h after high-glucose application (GTT2h). The FBG-GTT2h plots obtained with the wild strain fed the control diet (CD), Gk+/− strain fed the CD, and Gk+/− strain fed the HFD were distributed in separate areas in the FBG-GTT2h diagram. The respective areas could be defined as the normal state, prediabetes state, and diabetes state, respectively. Based on the results, the criteria for prediabetes could be defined for the Gk+/− strain developed in this study. PMID:25765873

  12. Common Missense Variant in the Glucokinase Regulatory Protein Gene Is Associated With Increased Plasma Triglyceride and C-Reactive Protein but Lower Fasting Glucose Concentrations

    PubMed Central

    Orho-Melander, Marju; Melander, Olle; Guiducci, Candace; Perez-Martinez, Pablo; Corella, Dolores; Roos, Charlotta; Tewhey, Ryan; Rieder, Mark J.; Hall, Jennifer; Abecasis, Goncalo; Tai, E. Shyong; Welch, Cullan; Arnett, Donna K.; Lyssenko, Valeriya; Lindholm, Eero; Saxena, Richa; de Bakker, Paul I.W.; Burtt, Noel; Voight, Benjamin F.; Hirschhorn, Joel N.; Tucker, Katherine L.; Hedner, Thomas; Tuomi, Tiinamaija; Isomaa, Bo; Eriksson, Karl-Fredrik; Taskinen, Marja-Riitta; Wahlstrand, Björn; Hughes, Thomas E.; Parnell, Laurence D.; Lai, Chao-Qiang; Berglund, Göran; Peltonen, Leena; Vartiainen, Erkki; Jousilahti, Pekka; Havulinna, Aki S.; Salomaa, Veikko; Nilsson, Peter; Groop, Leif; Altshuler, David; Ordovas, Jose M.; Kathiresan, Sekar

    2008-01-01

    OBJECTIVE—Using the genome-wide association approach, we recently identified the glucokinase regulatory protein gene (GCKR, rs780094) region as a novel quantitative trait locus for plasma triglyceride concentration in Europeans. Here, we sought to study the association of GCKR variants with metabolic phenotypes, including measures of glucose homeostasis, to evaluate the GCKR locus in samples of non-European ancestry and to fine- map across the associated genomic interval. RESEARCH DESIGN AND METHODS—We performed association studies in 12 independent cohorts comprising >45,000 individuals representing several ancestral groups (whites from Northern and Southern Europe, whites from the U.S., African Americans from the U.S., Hispanics of Caribbean origin, and Chinese, Malays, and Asian Indians from Singapore). We conducted genetic fine-mapping across the ∼417-kb region of linkage disequilibrium spanning GCKR and 16 other genes on chromosome 2p23 by imputing untyped HapMap single nucleotide polymorphisms (SNPs) and genotyping 104 SNPs across the associated genomic interval. RESULTS—We provide comprehensive evidence that GCKR rs780094 is associated with opposite effects on fasting plasma triglyceride (Pmeta = 3 × 10−56) and glucose (Pmeta = 1 × 10−13) concentrations. In addition, we confirmed recent reports that the same SNP is associated with C-reactive protein (CRP) level (P = 5 × 10−5). Both fine-mapping approaches revealed a common missense GCKR variant (rs1260326, Pro446Leu, 34% frequency, r2 = 0.93 with rs780094) as the strongest association signal in the region. CONCLUSIONS—These findings point to a molecular mechanism in humans by which higher triglycerides and CRP can be coupled with lower plasma glucose concentrations and position GCKR in central pathways regulating both hepatic triglyceride and glucose metabolism. PMID:18678614

  13. The glucokinase locus is an important contributor to glucose variation in the Chinese population at high risk for type II diabetes

    SciTech Connect

    Wu, D.A. |; Warden, C.H.; Lusis, A.J.

    1994-09-01

    Recently, major advances have been achieved in the genetics of maturity onset diabetes of the young (MODY) with two loci identified: the glucokinase (GCK) gene on chromosome (chr.) 7p and a locus near the adenosine deaminase (ADA) gene on chr. 20q. However, it is not known whether either of these MODY loci contribute to variation in glucose metabolism in populations other than MODY families. To examine this question, we have studied 94 Chinese nuclear families; 54 have both parents affected with type II diabetes, 22 have only one parent affected, and 18 have both normal parents. None of the affected diabetic probands were diagnosed prior to adulthood. Nondiabetic offspring were phenotyped by measuring plasma glucose and insulin responses to an oral glucose challenge. Parents and nondiabetic offspring were genotyped for dinucleotide repeat markers. two near the GCK locus and one near the ADA locus. Prior to linkage analysis, both glucose and insulin response variables were adjusted for the effects of age, sex, and body mass index. By non-parametric quantitative sib-pair linkage analysis, we found no evidence for linkage of glucose response variables with the ADA locus on chr. 20q (p=0.64-0.92, 146 sibpairs). However, significant evidence for linkage of log-transformed integrated glucose response area was observed with the GCK locus (haplotypes based on two tightly linked GCK markers) on chr. 7p (p=0.001, N=127). Linkage with the GCK locus was also demonstrated. In contrast, insulin variables, including integrated response area and responses at different time points, showed no evidence of linkage with either the ADA or GCK loci, despite the positive correlation between glucose and insulin responses in these families. These data raise the possibility that the GCK gene may be involved as one of the contributing genes in the etiology of type II diabetes in the Chinese population.

  14. Genetic Polymorphism of Glucokinase on the Risk of Type 2 Diabetes and Impaired Glucose Regulation: Evidence Based on 298, 468 Subjects

    PubMed Central

    Ma, Yushui; Cai, Haidong; Cai, Mingxiang; Li, Dan; Lv, Mingli; Yuan, Xueyu; Huang, Yinghui; Lv, Zhongwei

    2013-01-01

    Background Glucokinase (GCK) is the key glucose phosphorylation enzyme which has attracted considerable attention as a candidate gene for type 2 diabetes (T2D) based on its enzyme function as the first rate-limiting step in the glycolysis pathway and regulates glucose-stimulated insulin secretion. In the past decade, the relationship between GCK and T2D has been reported in various ethnic groups. To derive a more precise estimation of the relationship and the effect of factors that might modify the risk, we performed this meta-analysis. Methods Databases including Pubmed, EMBASE, Web of Science and China National Knowledge Infrastructure (CNKI) were searched to find relevant studies. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of association. Results A total of 24 articles involving 88, 229 cases and 210, 239 controls were included. An overall random-effects per-allele OR of 1.06 (95% CI: 1.03–1.09; P<10−4) was found for the GCK −30G>A polymorphism. Significant results were also observed using dominant or recessive genetic models. In the subgroup analyses by ethnicity, significant results were found in Caucasians; whereas no significant associations were found among Asians. In addition, we found that the −30G>A polymorphism is a risk factor associated with increased impaired glucose regulation susceptibility. Besides, −30G>A homozygous was found to be significantly associated with increased fasting plasma glucose level with weighted mean difference (WMD) of 0.15 (95%: 0.05–0.24, P = 0.001) compared with G/G genotype. Conclusions This meta-analysis demonstrated that the −30G>A polymorphism of GCK is a risk factor associated with increased T2D susceptibility, but these associations vary in different ethnic populations. PMID:23441155

  15. Safety, tolerability, pharmacokinetics, and pharmacodynamics of novel glucokinase activator HMS5552: results from a first-in-human single ascending dose study

    PubMed Central

    Xu, Hongrong; Sheng, Lei; Chen, Weili; Yuan, Fei; Yang, Mengjie; Li, Hui; Li, Xuening; Choi, John; Zhao, Guiyu; Hu, Tianxin; Li, Yongguo; Zhang, Yi; Chen, Li

    2016-01-01

    Background HMS5552, a novel fourth-generation glucokinase (GK) activator, has demonstrated promising effects on glycemic control in preclinical models of type 2 diabetes. This single ascending dose study was conducted to investigate the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of HMS5552 during its first-in-human exposure. Methods Sixty healthy subjects were enrolled. In each of six dose-cohorts (5, 10, 15, 25, 35, and 50 mg), ten subjects were randomized with eight subjects receiving the same cohort-dose of HMS5552 and two receiving placebo. Plasma HMS5552 exposure, glucose, and insulin were measured repeatedly during fasting and after a standardized meal. Assessment included safety, PK, and PD endpoints. Results HMS5552 showed dose-proportional increases in area under the curve 0 to the last quantifiable concentration (AUC0–t) and maximum plasma concentration (Cmax). Slopes estimated by linear regression for AUC0–t and Cmax were ~1.0 (0.932 and 0.933, respectively). Geometric mean elimination half-life ranged from 4.48 to 7.51 hours and apparent clearance ranged from 11.5 to 13.1 L/h across all doses. No significant sex effect was observed in PK parameters. HMS5552 also demonstrated dose-related PD responses in terms of maximum glucose change from baseline (%) and mean glucose area under effect curve 0–4 hours change from baseline (%) (P<0.001). Fifteen adverse events were reported by nine subjects (ten with HMS5552 and five with the placebo). All adverse events were mild in intensity and resolved without any treatment. Conclusion This first-in-human single ascending dose study provided predicted PK of HMS5552 with dose-proportional increases in AUC0–t and Cmax, as well as dose-related glucose-lowering effects over the range of 5–50 mg in healthy subjects. HMS5552 at doses up to 50 mg in healthy subjects was safe and well-tolerated. PMID:27274195

  16. Vanadate treatment restores the expression of genes for key enzymes in the glucose and ketone bodies metabolism in the liver of diabetic rats.

    PubMed Central

    Valera, A; Rodriguez-Gil, J E; Bosch, F

    1993-01-01

    Oral administration of vanadate to diabetic streptozotocin-treated rats decreased the high blood glucose and D-3-hydroxybutyrate levels related to diabetes. The increase in the expression of the P-enolpyruvate carboxykinase (PEPCK) gene, the main regulatory enzyme of gluconeogenesis, was counteracted in the liver and the kidney after vanadate administration to diabetic rats. Vanadate also counteracted the induction in tyrosine aminotransferase gene expression due to diabetes and was able to increase the expression of the glucokinase gene to levels even higher than those found in healthy animals. Similarly, an induction in pyruvate kinase mRNA transcripts was observed in diabetic vanadate-treated rats. These effects were correlated with changes on glucokinase and pyruvate kinase activities. Vanadate treatment caused a decrease in the expression of the liver-specific glucose transporter, GLUT-2. Thus, vanadate was able to restore liver glucose utilization and block glucose production in diabetic rats. The increase in the expression of the mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase (HMGCoAS) gene, the key regulatory enzyme in the ketone bodies production pathway, observed in diabetic rats was also blocked by vanadate. Furthermore, a similar pattern in the expression of PEPCK, GLUT-2, HMGCoAS, and the transcription factor CCAAT/enhancer-binding protein alpha genes has been observed. All of these results suggest that the regulation of the expression of genes involved in the glucose and ketone bodies metabolism could be a key step in the normalization process induced by vanadate administration to diabetic rats. Images PMID:8100835

  17. Collagen esterification enhances the function and survival of pancreatic β cells in 2D and 3D culture systems

    SciTech Connect

    Ko, Jae Hyung; Kim, Yang Hee; Jeong, Seong Hee; Lee, Song; Park, Si-Nae; Shim, In Kyong; Kim, Song Cheol

    2015-08-07

    Collagen, one of the most important components of the extracellular matrix (ECM), may play a role in the survival of pancreatic islet cells. In addition, chemical modifications that change the collagen charge profile to a net positive charge by esterification have been shown to increase the adhesion and proliferation of various cell types. The purpose of this study was to characterize and compare the effects of native collagen (NC) and esterified collagen (EC) on β cell function and survival. After isolation by the collagenase digestion technique, rat islets were cultured with NC and EC in 2 dimensional (2D) and 3 dimensional (3D) environments for a long-term duration in vitro. The cells were assessed for islet adhesion, morphology, viability, glucose-induced insulin secretion, and mRNA expression of glucose metabolism-related genes, and visualized by scanning electron microscopy (SEM). Islet cells attached tightly in the NC group, but islet cell viability was similar in both the NC and EC groups. Glucose-stimulated insulin secretion was higher in the EC group than in the NC group in both 2D and 3D culture. Furthermore, the mRNA expression levels of glucokinase in the EC group were higher than those in the NC group and were associated with glucose metabolism and insulin secretion. Finally, SEM observation confirmed that islets had more intact component cells on EC sponges than on NC sponges. These results indicate that modification of collagen may offer opportunities to improve function and viability of islet cells. - Highlights: • We changed the collagen charge profile to a net positive charge by esterification. • Islets cultured on esterified collagen improved survival in both 2D and 3D culture. • Islets cultured on esterified collagen enhanced glucose-stimulated insulin release. • High levels of glucokinase mRNA may be associated with increased insulin release.

  18. Interindividual variations in metabolism and pharmacokinetics of 3-(6-methylpyridine-3-yl-sulfanyl)-6-(4H-[1,2,4]triazole-3-yl-sulfanyl)-N-(1,3-thiazole-2-yl)-2-pyridine carboxamide, a glucokinase activator, in rats caused by the genetic polymorphism of CYP2D1.

    PubMed

    Hasegawa, Takuro; Eiki, Jun-ichi; Chiba, Masato

    2014-09-01

    3-(6-Methylpyridine-3-yl-sulfanyl)-6-(4H-[1,2,4]triazole-3-yl-sulfanyl)-N-(1,3-thiazole-2-yl)-2-pyridine carboxamide (Cpd-D) is a novel glucokinase activator that is being developed for the treatment of type 2 diabetes. Large interindividual variations were observed in the pharmacokinetics of Cpd-D in male Sprague-Dawley (SD) rats, which were subsequently divided into two phenotypes; >6-fold longer terminal-phase half-life and ∼10-fold larger AUC0-∞ values were observed in slow metabolizers (SM) than in fast metabolizers (FM) after the oral administration of Cpd-D. The thiohydantoic acid analog (M2) was the predominant metabolite detected in the urine, bile, and plasma after the oral administration of [(14)C]Cpd-D to the FM phenotypes of bile-duct cannulated SD rats. The liver microsomes prepared from FM phenotyped rats extensively formed M2 with the highest affinity (Km = 0.09 μM) and largest Vmax/Km value in primary metabolism, whereas those from SM phenotypes had little capacity to form M2. Of the rat cytochrome P450 isoforms tested, the formation of M2 was only catalyzed by recombinant CYP2D1. Sequence substitutions (418A/421C and 418G/421T) were detected in the CYP2D1 gene and were designated F and S alleles, respectively. The genotype-phenotype correlation analysis indicated that two S alleles were homozygous (S/S) in the SM phenotypes, whereas the FM phenotypes were either homozygous for the F-alleles (F/F) or heterozygous (F/S). These results indicated that the CYP2D1 polymorphism caused by nucleotide substitutions (418A/421C versus 418G/421T) was responsible for interindividual variations leading to the polymorphism in the major metabolism and pharmacokinetics of Cpd-D in male SD rats. PMID:24924387

  19. Moral Enhancement

    PubMed Central

    Douglas, Thomas

    2008-01-01

    Opponents of biomedical enhancement often claim that, even if such enhancement would benefit the enhanced, it would harm others. But this objection looks unpersuasive when the enhancement in question is a moral enhancement — an enhancement that will expectably leave the enhanced person with morally better motives than she had previously. In this article I (1) describe one type of psychological alteration that would plausibly qualify as a moral enhancement, (2) argue that we will, in the medium-term future, probably be able to induce such alterations via biomedical intervention, and (3) defend future engagement in such moral enhancements against possible objections. My aim is to present this kind of moral enhancement as a counter-example to the view that biomedical enhancement is always morally impermissible. PMID:19132138

  20. Protective effect of bioflavonoid myricetin enhances carbohydrate metabolic enzymes and insulin signaling molecules in streptozotocin–cadmium induced diabetic nephrotoxic rats

    SciTech Connect

    Kandasamy, Neelamegam; Ashokkumar, Natarajan

    2014-09-01

    Diabetic nephropathy is the kidney disease that occurs as a result of diabetes. The present study was aimed to evaluate the therapeutic potential of myricetin by assaying the activities of key enzymes of carbohydrate metabolism, insulin signaling molecules and renal function markers in streptozotocin (STZ)–cadmium (Cd) induced diabetic nephrotoxic rats. After myricetin treatment schedule, blood and tissue samples were collected to determine plasma glucose, insulin, hemoglobin, glycosylated hemoglobin and renal function markers, carbohydrate metabolic enzymes in the liver and insulin signaling molecules in the pancreas and skeletal muscle. A significant increase of plasma glucose, glycosylated hemoglobin, urea, uric acid, creatinine, blood urea nitrogen (BUN), urinary albumin, glycogen phosphorylase, glucose-6-phosphatase, and fructose-1,6-bisphosphatase and a significant decrease of plasma insulin, hemoglobin, hexokinase, glucose-6-phosphate dehydrogenase, glycogen and glycogen synthase with insulin signaling molecule expression were found in the STZ–Cd induced diabetic nephrotoxic rats. The administration of myricetin significantly normalizes the carbohydrate metabolic products like glucose, glycated hemoglobin, glycogen phosphorylase and gluconeogenic enzymes and renal function markers with increase insulin, glycogen, glycogen synthase and insulin signaling molecule expression like glucose transporter-2 (GLUT-2), glucose transporter-4 (GLUT-4), insulin receptor-1 (IRS-1), insulin receptor-2 (IRS-2) and protein kinase B (PKB). Based on the data, the protective effect of myricetin was confirmed by its histological annotation of the pancreas, liver and kidney tissues. These findings suggest that myricetin improved carbohydrate metabolism which subsequently enhances glucose utilization and renal function in STZ–Cd induced diabetic nephrotoxic rats. - Highlights: • Diabetic rats are more susceptible to cadmium nephrotoxicity. • Cadmium plays as a cumulative

  1. Soy Leaf Extract Containing Kaempferol Glycosides and Pheophorbides Improves Glucose Homeostasis by Enhancing Pancreatic β-Cell Function and Suppressing Hepatic Lipid Accumulation in db/db Mice.

    PubMed

    Li, Hua; Ji, Hyeon-Seon; Kang, Ji-Hyun; Shin, Dong-Ha; Park, Ho-Yong; Choi, Myung-Sook; Lee, Chul-Ho; Lee, In-Kyung; Yun, Bong-Sik; Jeong, Tae-Sook

    2015-08-19

    This study investigated the molecular mechanisms underlying the antidiabetic effect of an ethanol extract of soy leaves (ESL) in db/db mice. Control groups (db/+ and db/db) were fed a normal diet (ND), whereas the db/db-ESL group was fed ND with 1% ESL for 8 weeks. Dietary ESL improved glucose tolerance and lowered plasma glucose, glycated hemoglobin, HOMA-IR, and triglyceride levels. The pancreatic insulin content of the db/db-ESL group was significantly greater than that of the db/db group. ESL supplementation altered pancreatic IRS1, IRS2, Pdx1, Ngn3, Pax4, Ins1, Ins2, and FoxO1 expression. Furthermore, ESL suppressed lipid accumulation and increased glucokinase activity in the liver. ESL primarily contained kaempferol glycosides and pheophorbides. Kaempferol, an aglycone of kaempferol glycosides, improved β-cell proliferation through IRS2-related FoxO1 signaling, whereas pheophorbide a, a product of chlorophyll breakdown, improved insulin secretion and β-cell proliferation through IRS1-related signaling with protein kinase A in MIN6 cells. ESL effectively regulates glucose homeostasis by enhancing IRS-mediated β-cell insulin signaling and suppressing SREBP-1-mediated hepatic lipid accumulation in db/db mice. PMID:26211813

  2. Mafa expression enhances glucose-responsive insulin secretion in neonatal rat beta cells

    PubMed Central

    Aguayo-Mazzucato, C.; Koh, A.; El Khattabi, I.; Li, W.-C.; Toschi, E.; Jermendy, A.; Juhl, K.; Mao, K.; Weir, G. C.

    2011-01-01

    Aim/hypothesis Neonatal beta cells lack glucose-stimulated insulin secretion and are thus functionally immature. We hypothesised that this lack of glucose responsiveness results from a generalised low expression of genes characteristic of mature functional beta cells. Important glucose-responsive transcription factors, Mafa and Pdx1, regulate genes involved in insulin synthesis and secretion, and have been implicated in late beta cell development. The aim of this study was to assess whether Mafa and/or Pdx1 regulates the postnatal functional maturation of beta cells. Methods By quantitative PCR we evaluated expression of these and other beta cell genes over the first month compared with adult. After infection with adenovirus expressing MAFA, Pdx1 or green fluorescent protein (Gfp), P2 rat islets were evaluated by RT-PCR and insulin secretion with static incubation and reverse haemolytic plaque assay (RHPA). Results At P2 most beta cell genes were expressed at about 10% of adult, but by P7 Pdx1 and Neurod1 no longer differ from adult; by contrast, Mafa expression remained significantly lower than adult through P21. Overexpression of Pdx1 increased Mafa, Neurod1, glucokinase (Gck) mRNA and insulin content but failed to enhance glucose responsiveness. Similar overexpression of MAFA resulted in increased Neurod1, Nkx6-1, Gck and Glp1r mRNAs and no change in insulin content but, importantly, acquisition of glucose-responsive insulin secretion. Both the percentage of secreting beta cells and the amount of insulin secreted per beta cell increased, approaching that of adult beta cells. Conclusions/interpretation In the process of functional maturation acquiring glucose-responsive insulin secretion, neonatal beta cells undergo a coordinated gene expression programme in which Mafa plays a crucial role. PMID:21190012

  3. Biocatalyst Enhancement

    EPA Science Inventory

    The increasing availability of enzyme collections has assisted attempts by pharmaceutical producers to adopt green chemistry approaches to manufacturing. A joint effort between an enzyme producer and a pharmaceutical manufacturer has been enhanced over the past three years by ena...

  4. Enhancer Analysis

    NASA Astrophysics Data System (ADS)

    Uchikawa, Masanori; Takemoto, Tatsuya

    During embryonic development, genes are expressed under a strict spatial and temporal order in cells and tissues. This regulation is governed by regulatory regions in the genome, usually identified as enhancers (Kondoh, 2008). The identification and mapping of a set of enhancers allow clarification of essential regulatory elements involved in the enhancer action and their interacting protein factors. Enhancer analysis also determines upstream signaling cascades that regulate interacting protein factors. If the regulatory regions do not function properly, spatio-temporal order of the gene expression will be disrupted, and this may cause abnormal development and dis eases (Kleinjan & van Heyningen, 2005; Sabherwal et al., 2007). Thus, identifica tion of the regulatory regions provides an important entry point to clarify regulatory mechanisms underlying embryonic development.

  5. LASIK enhancements.

    PubMed

    Durrie, D S; Vande Garde, T L

    2000-01-01

    As the field of refractive surgery continues to evolve, an increasing number of surgical options are available for LASIK enhancements. Nonetheless, older methods such as AK continue to play an important role in enhancement procedures. Improvements in instruments and techniques allow for previously made LASIK flaps to be safely lifted for additional myopic or hyperopic ablations. Newer methods such as Intacs placement provide an effective option for patients who are not good candidates for further ablative procedures. These advancements allow refractive surgeons to treat a wider range of myopia, hyperopia, and astigmatism effectively in eyes with a history of LASIK surgery. PMID:10941651

  6. Curcumin enhances recovery of pancreatic islets from cellular stress induced inflammation and apoptosis in diabetic rats

    SciTech Connect

    Rashid, Kahkashan; Sil, Parames C.

    2015-02-01

    The phytochemical, curcumin, has been reported to play many beneficial roles. However, under diabetic conditions, the detail mechanism of its beneficial action in the glucose homeostasis regulatory organ, pancreas, is poorly understood. The present study has been designed and carried out to explore the role of curcumin in the pancreatic tissue of STZ induced and cellular stress mediated diabetes in eight weeks old male Wistar rats. Diabetes was induced with a single intraperitoneal dose of STZ (65 mg/kg body weight). Post to diabetes induction, animals were treated with curcumin at a dose of 100 mg/kg body weight for eight weeks. Underlying molecular and cellular mechanism was determined using various biochemical assays, DNA fragmentation, FACS, histology, immunoblotting and ELISA. Treatment with curcumin reduced blood glucose level, increased plasma insulin and mitigated oxidative stress related markers. In vivo and in vitro experimental results revealed increased levels of proinflammatory cytokines (TNF-α, IL1-β and IFN-γ), reduced level of cellular defense proteins (Nrf-2 and HO-1) and glucose transporter (GLUT-2) along with enhanced levels of signaling molecules of ER stress dependent and independent apoptosis (cleaved Caspase-12/9/8/3) in STZ administered group. Treatment with curcumin ameliorated all the adverse changes and helps the organ back to its normal physiology. Results suggest that curcumin protects pancreatic beta-cells by attenuating inflammatory responses, and inhibiting ER/mitochondrial dependent and independent pathways of apoptosis and crosstalk between them. This uniqueness and absence of any detectable adverse effect proposes the possibility of using this molecule as an effective protector in the cellular stress mediated diabetes mellitus. - Highlights: • STZ induced cellular stress plays a vital role in pancreatic dysfunction. • Cellular stress causes inflammation, pancreatic islet cell death and diabetes. • Deregulation of Nrf-2

  7. Enhancing bioremediation

    SciTech Connect

    Koenigsberg, S.

    1997-02-01

    Oxygen is often the limiting factor in aerobic bioremediation. Without adequate oxygen, contaminant degradation will either cease or proceed by highly inefficient anaerobic processes. Researchers at Regenesis Bioremediation Products recently develope a technology to combat this problem, Oxygen Release Compound (ORC) a unique formulation of magnesium peroxide release oxygen slowly when hydrated. ORC is idea for supporting bioremediation of underground storage tank releases. ORC treatment represents a low intensity approach to remediation - simple, passive, low-cost, long term enhancement of a natural attenuation. 1 fig.

  8. EDITORIAL: Enhancing nanolithography Enhancing nanolithography

    NASA Astrophysics Data System (ADS)

    Demming, Anna

    2012-01-01

    Lithography was invented in late 18th century Bavaria by an ambitious young playwright named Alois Senefelder. Senefelder experimented with stone, wax, water and ink in the hope of finding a way of reproducing text so that he might financially gain from a wider distribution of his already successful scripts. His discovery not only facilitated the profitability of his plays, but also provided the world with an affordable printing press that would ultimately democratize the dissemination of art, knowledge and literature. Since Senefelder, experiments in lithography have continued with a range of innovations including the use of electron beams and UV that allow increasingly higher-resolution features [1, 2]. Applications for this have now breached the limits of paper printing into the realms of semiconductor and microelectronic mechanical systems technology. In this issue, researchers demonstrate a technique for fabricating periodic features in poly(3,4-ethylene dioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS) [3]. Their method combines field enhancements from silica nanospheres with laser-interference lithography to provide a means of patterning a polymer that has the potential to open the market of low-end, high-volume microelectronics. Laser-interference lithography has already been used successfully in patterning. Researchers in Korea used laser-interference lithography to generate stamps for imprinting a two-dimensional photonic crystal structure into green light emitting diodes (LEDs) [4]. The imprinted patterns comprised depressions 100 nm deep and 180 nm wide with a periodicity of 295 nm. In comparison with unpatterned LEDs, the intensity of photoluminescence was enhanced by a factor of seven in the LEDs that had the photonic crystal structures imprinted in them. The potential of exploiting field enhancements around nanostructures for new technologies has also attracted a great deal of attention. Researchers in the USA and Australia have used the field

  9. Dietary supplementation of a mixture of Lactobacillus strains enhances performance of broiler chickens raised under heat stress conditions

    NASA Astrophysics Data System (ADS)

    Faseleh Jahromi, Mohammad; Wesam Altaher, Yassir; Shokryazdan, Parisa; Ebrahimi, Roohollah; Ebrahimi, Mahdi; Idrus, Zulkifli; Tufarelli, Vincenzo; Liang, Juan Boo

    2016-07-01

    High ambient temperature is a major problem in commercial broiler production in the humid tropics because high producing broiler birds consume more feed, have higher metabolic activity, and thus higher body heat production. To evaluate the effects of two previously isolated potential probiotic strains ( Lactobacillus pentosus ITA23 and Lactobacillus acidophilus ITA44) on broilers growing under heat stress condition, a total of 192 chicks were randomly allocated into four treatment groups of 48 chickens each as follows: CL, birds fed with basal diet raised in 24 °C; PL, birds fed with basal diet plus 0.1 % probiotic mixture raised in 24 °C; CH, birds fed with basal diet raised in 35 °C; and PH, birds fed with basal diet plus 0.1 % probiotic mixture raised in 35 °C. The effects of probiotic mixture on the performance, expression of nutrient absorption genes of the small intestine, volatile fatty acids (VFA) and microbial population of cecal contents, antioxidant capacity of liver, and fatty acid composition of breast muscle were investigated. Results showed that probiotic positively affected the final body weight under both temperature conditions (PL and PH groups) compared to their respective control groups (CL and CH). Probiotic supplementation numerically improved the average daily gain (ADG) under lower temperature, but significantly improved ADG under the higher temperature ( P < 0.05) by sustaining high feed intake. Under the lower temperature environment, supplementation of the two Lactobacillus strains significantly increased the expression of the four sugar transporter genes tested (GLUT2, GLUT5, SGLT1, and SGLT4) indicating probiotic enhances the absorption of this nutrient. Similar but less pronounced effect was also observed under higher temperature (35 °C) condition. In addition, the probiotic mixture improved bacterial population of the cecal contents, by increasing beneficial bacteria and decreasing Escherichia coli population, which could be

  10. Dietary supplementation of a mixture of Lactobacillus strains enhances performance of broiler chickens raised under heat stress conditions.

    PubMed

    Faseleh Jahromi, Mohammad; Wesam Altaher, Yassir; Shokryazdan, Parisa; Ebrahimi, Roohollah; Ebrahimi, Mahdi; Idrus, Zulkifli; Tufarelli, Vincenzo; Liang, Juan Boo

    2016-07-01

    High ambient temperature is a major problem in commercial broiler production in the humid tropics because high producing broiler birds consume more feed, have higher metabolic activity, and thus higher body heat production. To evaluate the effects of two previously isolated potential probiotic strains (Lactobacillus pentosus ITA23 and Lactobacillus acidophilus ITA44) on broilers growing under heat stress condition, a total of 192 chicks were randomly allocated into four treatment groups of 48 chickens each as follows: CL, birds fed with basal diet raised in 24 °C; PL, birds fed with basal diet plus 0.1 % probiotic mixture raised in 24 °C; CH, birds fed with basal diet raised in 35 °C; and PH, birds fed with basal diet plus 0.1 % probiotic mixture raised in 35 °C. The effects of probiotic mixture on the performance, expression of nutrient absorption genes of the small intestine, volatile fatty acids (VFA) and microbial population of cecal contents, antioxidant capacity of liver, and fatty acid composition of breast muscle were investigated. Results showed that probiotic positively affected the final body weight under both temperature conditions (PL and PH groups) compared to their respective control groups (CL and CH). Probiotic supplementation numerically improved the average daily gain (ADG) under lower temperature, but significantly improved ADG under the higher temperature (P < 0.05) by sustaining high feed intake. Under the lower temperature environment, supplementation of the two Lactobacillus strains significantly increased the expression of the four sugar transporter genes tested (GLUT2, GLUT5, SGLT1, and SGLT4) indicating probiotic enhances the absorption of this nutrient. Similar but less pronounced effect was also observed under higher temperature (35 °C) condition. In addition, the probiotic mixture improved bacterial population of the cecal contents, by increasing beneficial bacteria and decreasing Escherichia coli population, which could

  11. Dietary supplementation of a mixture of Lactobacillus strains enhances performance of broiler chickens raised under heat stress conditions

    NASA Astrophysics Data System (ADS)

    Faseleh Jahromi, Mohammad; Wesam Altaher, Yassir; Shokryazdan, Parisa; Ebrahimi, Roohollah; Ebrahimi, Mahdi; Idrus, Zulkifli; Tufarelli, Vincenzo; Liang, Juan Boo

    2015-11-01

    High ambient temperature is a major problem in commercial broiler production in the humid tropics because high producing broiler birds consume more feed, have higher metabolic activity, and thus higher body heat production. To evaluate the effects of two previously isolated potential probiotic strains (Lactobacillus pentosus ITA23 and Lactobacillus acidophilus ITA44) on broilers growing under heat stress condition, a total of 192 chicks were randomly allocated into four treatment groups of 48 chickens each as follows: CL, birds fed with basal diet raised in 24 °C; PL, birds fed with basal diet plus 0.1 % probiotic mixture raised in 24 °C; CH, birds fed with basal diet raised in 35 °C; and PH, birds fed with basal diet plus 0.1 % probiotic mixture raised in 35 °C. The effects of probiotic mixture on the performance, expression of nutrient absorption genes of the small intestine, volatile fatty acids (VFA) and microbial population of cecal contents, antioxidant capacity of liver, and fatty acid composition of breast muscle were investigated. Results showed that probiotic positively affected the final body weight under both temperature conditions (PL and PH groups) compared to their respective control groups (CL and CH). Probiotic supplementation numerically improved the average daily gain (ADG) under lower temperature, but significantly improved ADG under the higher temperature (P < 0.05) by sustaining high feed intake. Under the lower temperature environment, supplementation of the two Lactobacillus strains significantly increased the expression of the four sugar transporter genes tested (GLUT2, GLUT5, SGLT1, and SGLT4) indicating probiotic enhances the absorption of this nutrient. Similar but less pronounced effect was also observed under higher temperature (35 °C) condition. In addition, the probiotic mixture improved bacterial population of the cecal contents, by increasing beneficial bacteria and decreasing Escherichia coli population, which could be

  12. GLUCAGON-LIKE PEPTIDE-2 INCREASES GLUCOSE UPTAKE BY INCREASING SGLT-1 AND GLUT2 ABUNDANCE IN TPN-FED NEONATAL PIGS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Children with intestinal dysfunction, often require total parenteral nutrition (TPN) to meet their nutritional needs. Although TPN provides the necessary nutrition, it may limit intestinal adaptation, growth, and restoration of normal function. The trophic gut peptide, glucagon-like peptide-2 (GLP-2...

  13. Autonomy and Enhancement.

    PubMed

    Schaefer, G Owen; Kahane, Guy; Savulescu, Julian

    2014-01-01

    Some have objected to human enhancement on the grounds that it violates the autonomy of the enhanced. These objections, however, overlook the interesting possibility that autonomy itself could be enhanced. How, exactly, to enhance autonomy is a difficult problem due to the numerous and diverse accounts of autonomy in the literature. Existing accounts of autonomy enhancement rely on narrow and controversial conceptions of autonomy. However, we identify one feature of autonomy common to many mainstream accounts: reasoning ability. Autonomy can then be enhanced by improving people's reasoning ability, in particular through cognitive enhancement; given how valuable autonomy is usually taken to be, this gives us extra reason to pursue such cognitive enhancements. Moreover, autonomy-based objections will be especially weak against such enhancements. As we will argue, those who are worried that enhancements will inhibit people's autonomy should actually embrace those enhancements that will improve autonomy. PMID:25045410

  14. Cognitive Enhancement and Education

    ERIC Educational Resources Information Center

    Buchanan, Allen

    2011-01-01

    Cognitive enhancement--augmenting normal cognitive capacities--is not new. Literacy, numeracy, computers, and the practices of science are all cognitive enhancements. Science is now making new cognitive enhancements possible. Biomedical cognitive enhancements (BCEs) include the administration of drugs, implants of genetically engineered or…

  15. Current enhancement update

    SciTech Connect

    Chambers, F.W.; Clark, J.C.; Struve, K.W.; Yu, S.S.

    1984-06-14

    Net current enhancement to levels in excess of the beam current has been observed in gases at pressures excess of 50 torr. We delineate the regimes where enhancement is observed. The experimental results fall into two very distinct classes; current enhancement at injection where the beam is only slightly displaced and current enhancement clearly associated with the high amplitude hose instability. A careful theoretical and experimental study of the diagnostics revealed no fundamental flaws although there are several complex and unlikely scenarios which could introduce fictitious current enhancement. Theoretical efforts indicate several mechanisms for generating enhancement but none of the theories can account for the detailed observations. 4 references, 4 figures.

  16. Enhancement and Civic Virtue

    PubMed Central

    Jefferson, Will; Douglas, Thomas; Kahane, Guy; Savulescu, Julian

    2014-01-01

    Opponents of biomedical enhancement frequently adopt what Allen Buchanan has called the Personal Goods Assumption. On this assumption, the benefits of biomedical enhancement will accrue primarily to those individuals who undergo enhancements, not to wider society. Buchanan has argued that biomedical enhancements might in fact have substantial social benefits by increasing productivity. We outline another way in which enhancements might benefit wider society: by augmenting civic virtue and thus improving the functioning of our political communities. We thus directly confront critics of biomedical enhancement who argue that it will lead to a loss of social cohesion and a breakdown in political life. PMID:24882886

  17. Enhancement and Civic Virtue.

    PubMed

    Jefferson, Will; Douglas, Thomas; Kahane, Guy; Savulescu, Julian

    2014-07-01

    Opponents of biomedical enhancement frequently adopt what Allen Buchanan has called the Personal Goods Assumption. On this assumption, the benefits of biomedical enhancement will accrue primarily to those individuals who undergo enhancements, not to wider society. Buchanan has argued that biomedical enhancements might in fact have substantial social benefits by increasing productivity. We outline another way in which enhancements might benefit wider society: by augmenting civic virtue and thus improving the functioning of our political communities. We thus directly confront critics of biomedical enhancement who argue that it will lead to a loss of social cohesion and a breakdown in political life. PMID:24882886

  18. Smart Image Enhancement Process

    NASA Technical Reports Server (NTRS)

    Jobson, Daniel J. (Inventor); Rahman, Zia-ur (Inventor); Woodell, Glenn A. (Inventor)

    2012-01-01

    Contrast and lightness measures are used to first classify the image as being one of non-turbid and turbid. If turbid, the original image is enhanced to generate a first enhanced image. If non-turbid, the original image is classified in terms of a merged contrast/lightness score based on the contrast and lightness measures. The non-turbid image is enhanced to generate a second enhanced image when a poor contrast/lightness score is associated therewith. When the second enhanced image has a poor contrast/lightness score associated therewith, this image is enhanced to generate a third enhanced image. A sharpness measure is computed for one image that is selected from (i) the non-turbid image, (ii) the first enhanced image, (iii) the second enhanced image when a good contrast/lightness score is associated therewith, and (iv) the third enhanced image. If the selected image is not-sharp, it is sharpened to generate a sharpened image. The final image is selected from the selected image and the sharpened image.

  19. Suboptimization of developmental enhancers.

    PubMed

    Farley, Emma K; Olson, Katrina M; Zhang, Wei; Brandt, Alexander J; Rokhsar, Daniel S; Levine, Michael S

    2015-10-16

    Transcriptional enhancers direct precise on-off patterns of gene expression during development. To explore the basis for this precision, we conducted a high-throughput analysis of the Otx-a enhancer, which mediates expression in the neural plate of Ciona embryos in response to fibroblast growth factor (FGF) signaling and a localized GATA determinant. We provide evidence that enhancer specificity depends on submaximal recognition motifs having reduced binding affinities ("suboptimization"). Native GATA and ETS (FGF) binding sites contain imperfect matches to consensus motifs. Perfect matches mediate robust but ectopic patterns of gene expression. The native sites are not arranged at optimal intervals, and subtle changes in their spacing alter enhancer activity. Multiple tiers of enhancer suboptimization produce specific, but weak, patterns of expression, and we suggest that clusters of weak enhancers, including certain "superenhancers," circumvent this trade-off in specificity and activity. PMID:26472909

  20. Enhancement of video images.

    PubMed

    Baily, N A; Nachazel, R J

    1980-04-01

    The enhancement of radiographic and fluoroscopic images using simple video analog techniques is described. In each instance, both the degree of enhancement and the features of the image to be enhanced are under the direct control of the radiologist. Noise is suppressed with a sharp cut-off, low-pass filter. Three types of analog circuits are discussed. One provides edge sharpening and contrast enhancement; one allows either black or white suppression, with expansion of the remaining shades of gray; and one provides an exponential response to selectable portions of the input signal. PMID:7360962

  1. [Medical image enhancement: Sharpening].

    PubMed

    Kats, L; Vered, M

    2015-04-01

    Most digital imaging systems provide opportunities for image enhancement operations. These are applied to improve the original image and to make the image more appealing visually. One possible means of enhancing digital radiographic image is sharpening. The purpose of sharpening filters is to improve image quality by removing noise or edge enhancement. Sharpening filters may make the radiographic images subjectively more appealing. But during this process, important radiographic features may disappear while artifacts that simulate pathological process might be generated. Therefore, it is of utmost importance for dentists to be familiar with and aware of the use of image enhancement operations, provided by medical digital imaging programs. PMID:26255429

  2. Credit Enhancement Overview Guide

    SciTech Connect

    Financing Solutions Working Group

    2014-01-01

    Provides considerations for state and local policymakers and energy efficiency program administrators designing and implementing successful credit enhancement strategies for residential and commercial buildings.

  3. Heat exchange enhancement structure

    SciTech Connect

    Cornelison, R.C.; Kreith, F.

    1980-12-02

    A passive heat exchange enhancement structure which operates by free convection includes a flat mounting portion having a plurality of integral fins bent outwardly from one side edge thereof. The mounting portion is securable around a stovepipe, to a flat surface or the like for transferring heat from the pipe through the fins to the surrounding air by rotation-enhanced free convection.

  4. Enhancing Drug Court Success

    ERIC Educational Resources Information Center

    Deschenes, Elizabeth Piper; Ireland, Connie; Kleinpeter, Christine B.

    2009-01-01

    This study evaluates the impact of enhanced drug court services in a large county in Southern California. These enhanced services, including specialty counseling groups, educational/employment resources, and increased Residential Treatment (RT) beds, were designed to increase program retention and successful completion (graduation) of drug court.…

  5. Enhanced oil recovery update

    SciTech Connect

    Smith, R.V

    1989-03-01

    Technology continues to grow in the realm of enhanced oil recovery. Since 1950 several processes have proven economic for oil recovery. Others are still in their infancy and must be custom designed for each reservoir. This paper gives a general overview of these processes. The author focuses on the latest technology and the outlook for enhanced oil recovery operations.

  6. Enhancing Individual Readiness.

    ERIC Educational Resources Information Center

    1997

    This document contains three papers from a symposium on enhancing individual readiness through human resource development (HRD). "Secondary School Administrator's Perception of Enhancing Self-Worth through Service" (Thomas Li-Ping Tang, Emily James Weatherford) presents results of a study to examine secondary school administrators' endorsement of…

  7. Should we enhance animals?

    PubMed Central

    Chan, Sarah

    2012-01-01

    Much bioethical discussion has been devoted to the subject of human enhancement through various technological means such as genetic modification. Although many of the same technologies could be, indeed in many cases already have been, applied to non-human animals, there has been very little consideration of the concept of “animal enhancement”, at least not in those specific terms. This paper addresses the notion of animal enhancement and the ethical issues surrounding it. A definition of animal enhancement is proposed that provides a framework within which to consider these issues; and it is argued that if human enhancement can be considered to be a moral obligation, so too can animal enhancement. PMID:19880704

  8. EDITORIAL: Nano-enhanced! Nano-enhanced!

    NASA Astrophysics Data System (ADS)

    Demming, Anna

    2010-08-01

    In the early 19th century, a series of engineering and scientific breakthroughs by Nicolas Léonard Sadi Carnot, James Watt and many others led to the foundations of thermodynamics and a new pedigree of mechanical designs that reset the standards of engineering efficiency. The result was the industrial revolution. In optical- and electronics- based nanotechnology research, a similarly subtle bargain is being made; we cannot alter the fact that systems have a finite response to external excitations, but what we can do is enhance that response. The promising attributes of ZnO have long been recognised; its large band gap and high exciton binding energy lend it to a number of applications from laser diodes, LEDs, optical waveguides and switches, and acousto-optic applications to sun cream. When this material is grown into nanowires and nanorods, the material gains a whole new dimension, as quantum confinement effects come into play. Discovery of the enhanced radiative recombination, which has potential for exploitation in many optical and opto-electronic applications, drove intensive research into investigating these structures and into finding methods to synthesise them with optimised properties. This research revealed further subtleties in the properties of these materials. One example is the work by researchers in the US reporting synthesis procedures that produced a yield—defined as the weight ratio of ZnO nanowires to the original graphite flakes—of 200%, and which also demonstrated, through photoluminescence analysis of nanowires grown on graphite flakes and substrates, that graphite induces oxygen vacancies during annealing, which enhances the deep-level to near-band-edge emission ratio [1]. Other one-dimensional materials that provide field emission enhancements include carbon nanotubes, and work has been performed to find ways of optimising the emission efficiency from these structures, such as through control of the emitter density [2]. One of the

  9. Long-Term Administration of Dehydroepiandrosterone Accelerates Glucose Catabolism via Activation of PI3K/Akt-PFK-2 Signaling Pathway in Rats Fed a High-Fat Diet

    PubMed Central

    Kang, Jian; Ge, Chongyang; Yu, Lei; Li, Longlong; Ma, Haitian

    2016-01-01

    Dehydroepiandrosterone (DHEA) has a fat-reducing effect, while little information is available on whether DHEA regulates glucose metabolism, which would in turn affect fat deposition. To investigate the effects of DHEA on glucose metabolism, rats were administered a high-fat diet containing either 0 (HCG), 25 (HLG), 50 (HMG), or 100 (HHG) mg·kg-1 DHEA per day via gavage for 8 weeks. Results showed that long-term administration of DHEA inhibited body weight gain in rats on a high-fat diet. No statistical differences in serum glucose levels were observed, whereas hepatic glycogen content in HMG and HHG groups and muscle glycogen content in HLG and HMG groups were higher than those in HCG group. Glucokinase, malate dehydrogenase and phosphofructokinase-2 activities in HMG and HHG groups, pyruvate kinase and succinate dehydrogenase activities in HMG group, and pyruvate dehydrogenase activity in all DHEA treatment groups were increased compared with those in HCG group. Phosphoenolpyruvate carboxykinase and glycogen phosphorylase mRNA levels were decreased in HMG and HHG groups, whereas glycogen synthase-2 mRNA level was increased in HMG group compared with those in HCG. The abundance of Glut2 mRNA in HMG and HHG groups and Glut4 mRNA in HMG group was higher than that in HCG group. DHEA treatment increased serum leptin content in HMG and HHG groups compared with that in HCG group. Serum insulin content and insulin receptor mRNA level in HMG group and insulin receptor substrate-2 mRNA level in HMG and HHG group were increased compared with those in HCG group. Furthermore, Pi3k mRNA level in HMG and Akt mRNA level in HMG and HHG groups were significantly increased than those in HCG group. These data showed that DHEA treatment could enhance glycogen storage and accelerate glucose catabolism in rats fed a high-fat diet, and this effect may be associated with the activation of PI3K/Akt-PFK-2 signaling pathway. PMID:27410429

  10. Long-Term Administration of Dehydroepiandrosterone Accelerates Glucose Catabolism via Activation of PI3K/Akt-PFK-2 Signaling Pathway in Rats Fed a High-Fat Diet.

    PubMed

    Kang, Jian; Ge, Chongyang; Yu, Lei; Li, Longlong; Ma, Haitian

    2016-01-01

    Dehydroepiandrosterone (DHEA) has a fat-reducing effect, while little information is available on whether DHEA regulates glucose metabolism, which would in turn affect fat deposition. To investigate the effects of DHEA on glucose metabolism, rats were administered a high-fat diet containing either 0 (HCG), 25 (HLG), 50 (HMG), or 100 (HHG) mg·kg-1 DHEA per day via gavage for 8 weeks. Results showed that long-term administration of DHEA inhibited body weight gain in rats on a high-fat diet. No statistical differences in serum glucose levels were observed, whereas hepatic glycogen content in HMG and HHG groups and muscle glycogen content in HLG and HMG groups were higher than those in HCG group. Glucokinase, malate dehydrogenase and phosphofructokinase-2 activities in HMG and HHG groups, pyruvate kinase and succinate dehydrogenase activities in HMG group, and pyruvate dehydrogenase activity in all DHEA treatment groups were increased compared with those in HCG group. Phosphoenolpyruvate carboxykinase and glycogen phosphorylase mRNA levels were decreased in HMG and HHG groups, whereas glycogen synthase-2 mRNA level was increased in HMG group compared with those in HCG. The abundance of Glut2 mRNA in HMG and HHG groups and Glut4 mRNA in HMG group was higher than that in HCG group. DHEA treatment increased serum leptin content in HMG and HHG groups compared with that in HCG group. Serum insulin content and insulin receptor mRNA level in HMG group and insulin receptor substrate-2 mRNA level in HMG and HHG group were increased compared with those in HCG group. Furthermore, Pi3k mRNA level in HMG and Akt mRNA level in HMG and HHG groups were significantly increased than those in HCG group. These data showed that DHEA treatment could enhance glycogen storage and accelerate glucose catabolism in rats fed a high-fat diet, and this effect may be associated with the activation of PI3K/Akt-PFK-2 signaling pathway. PMID:27410429

  11. Antidiabetic activity of zinc oxide and silver nanoparticles on streptozotocin-induced diabetic rats.

    PubMed

    Alkaladi, Ali; Abdelazim, Aaser Mohamed; Afifi, Mohamed

    2014-01-01

    The use of nanoparticles in medicine is an attractive proposition. In the present study, zinc oxide and silver nanoparticles were evaluated for their antidiabetic activity. Fifty male albino rats with weight 120 ± 20 and age 6 months were used. Animals were grouped as follows: control; did not receive any type of treatment, diabetic; received a single intraperitoneal dose of streptozotocin (100 mg/kg), diabetic + zinc oxide nanoparticles (ZnONPs), received single daily oral dose of 10 mg/kg ZnONPs in suspension, diabetic + silver nanoparticles (SNPs); received a single daily oral dose of SNP of 10 mg/kg in suspension and diabetic + insulin; received a single subcutaneous dose of 0.6 units/50 g body weight. Zinc oxide and silver nanoparticles induce a significant reduced blood glucose, higher serum insulin, higher glucokinase activity higher expression level of insulin, insulin receptor, GLUT-2 and glucokinase genes in diabetic rats treated with zinc oxide, silver nanoparticles and insulin. In conclusion, zinc oxide and sliver nanoparticles act as potent antidiabetic agents. PMID:24477262

  12. Enhancer Malfunction in Cancer

    PubMed Central

    Herz, Hans-Martin; Hu, Deqing; Shilatifard, Ali

    2014-01-01

    Why certain point mutations in a general transcription factor are associated with specific forms of cancer has been a major question in cancer biology. Enhancers are DNA regulatory elements that are major regulators of tissue-specific gene expression. Recent studies suggest that enhancer malfunction through point mutations in either regulatory elements or factors modulating enhancer-promoter communication could be the cause of tissue-specific cancer development. In this Perspective, we will discuss recent findings in the identification of cancer-related enhancer mutations and the role of Drosophila Trr and its human homologs, the MLL3 and MLL4/COMPASS-like complexes, as enhancer histone H3 lysine 4 (H3K4) monomethyltransferases functioning in enhancer-promoter communication. Recent genome-wide studies in the cataloging of somatic mutations in cancer have identified mutations in intergenic sequences encoding regulatory elements, and in MLL3 and MLL4 in both hematological malignancies and solid tumors. We propose that cancer-associated mutations in MLL3 and MLL4 exert their properties through the malfunction of Trr/MLL3/MLL4-dependent enhancers. PMID:24656127

  13. Hierarchical image enhancement

    NASA Astrophysics Data System (ADS)

    Qi, Wei; Han, Jing; Zhang, Yi; Bai, Lian-fa

    2016-05-01

    Image enhancement is an important technique in computer vision. In this paper, we propose a hierarchical image enhancement approach based on the structure layer and texture layer. In the structure layer, we propose a structure-based method based on GMM, which better exploits structure details with fewer noise. In the texture layer, we present a structure-filtering method to filter unwanted texture with keeping completeness of detected salient structure. Next, we introduce a structure constraint prior to integrate them, leading to an improved enhancement result. Extensive experiments demonstrate that the proposed approach achieves higher quality results than previous approaches.

  14. On latent fingerprint enhancement

    NASA Astrophysics Data System (ADS)

    Yoon, Soweon; Feng, Jianjiang; Jain, Anil K.

    2010-04-01

    Automatic feature extraction in latent fingerprints is a challenging problem due to poor quality of most latents, such as unclear ridge structures, overlapped lines and letters, and overlapped fingerprints. We proposed a latent fingerprint enhancement algorithm which requires manually marked region of interest (ROI) and singular points. The core of the proposed enhancement algorithm is a novel orientation field estimation algorithm, which fits orientation field model to coarse orientation field estimated from skeleton outputted by a commercial fingerprint SDK. Experimental results on NIST SD27 latent fingerprint database indicate that by incorporating the proposed enhancement algorithm, the matching accuracy of the commercial matcher was significantly improved.

  15. Plasmon-Enhanced Upconversion.

    PubMed

    Wu, Di M; García-Etxarri, Aitzol; Salleo, Alberto; Dionne, Jennifer A

    2014-11-20

    Upconversion, the conversion of photons from lower to higher energies, is a process that promises applications ranging from high-efficiency photovoltaic and photocatalytic cells to background-free bioimaging and therapeutic probes. Existing upconverting materials, however, remain too inefficient for viable implementation. In this Perspective, we describe the significant improvements in upconversion efficiency that can be achieved using plasmon resonances. As collective oscillations of free electrons, plasmon resonances can be used to enhance both the incident electromagnetic field intensity and the radiative emission rates. To date, this approach has shown upconversion enhancements up to 450×. We discuss both theoretical underpinnings and experimental demonstrations of plasmon-enhanced upconversion, examining the roles of upconverter quantum yield, plasmonic geometry, and plasmon spectral overlap. We also discuss nonoptical consequences of including metal nanostructures near upconverting emitters. The rapidly expanding field of plasmon-enhanced upconversion provides novel fundamental insight into nanoscale light-matter interactions while improving prospects for technological relevance. PMID:26276488

  16. LIGNITE FUEL ENHANCEMENT

    SciTech Connect

    Charles Bullinger

    2005-06-07

    This 3rd quarterly Technical Progress Report for the Lignite Fuel Enhancement Project summarizes activities from January 1st through March 31st of 2005. It also summarizes the subsequent purchasing activity and final dryer/process design.

  17. Enhanced Chemical Cleaning

    SciTech Connect

    Spires, Renee H.

    2010-11-01

    Renee Spires, Project Manager at Savannah River Remediation, opens Session 3 (Accelerated Waste Retrieval and Closure: Key Technologies) at the 2010 EM Waste Processing Technical Exchange with a talk on enhanced chemical cleaning.

  18. LIGNITE FUEL ENHANCEMENT

    SciTech Connect

    Charles Bullinger

    2005-07-07

    This 4th quarterly Technical Progress Report for the Lignite Fuel Enhancement Project summarizes activities from April 1st through June 30th of 2005. It also summarizes the subsequent purchasing activity and dryer/process construction.

  19. Enhanced metabolite generation

    DOEpatents

    Chidambaram, Devicharan

    2012-03-27

    The present invention relates to the enhanced production of metabolites by a process whereby a carbon source is oxidized with a fermentative microbe in a compartment having a portal. An electron acceptor is added to the compartment to assist the microbe in the removal of excess electrons. The electron acceptor accepts electrons from the microbe after oxidation of the carbon source. Other transfers of electrons can take place to enhance the production of the metabolite, such as acids, biofuels or brewed beverages.

  20. Enhancing Displays by Blurring

    NASA Technical Reports Server (NTRS)

    Tiana, C.; Pavel, M.; Ahumada, Albert J., Jr.; Statler, Irving C. (Technical Monitor)

    1994-01-01

    Some Enhanced Vision cockpit displays consist of synthetic imagery superimposed on a real image. The high spatial frequency components of the synthetic imagery can mislead an operator by masking features of the real image. We demonstrate that blurring the synthetic image prior to superposition reduces its masking effect in high- contrast regions of the real image, while maintaining its enhancing properties in regions of the real image where visibility is low.

  1. MORAL ENHANCEMENT AND FREEDOM

    PubMed Central

    Harris, John

    2011-01-01

    This paper identifies human enhancement as one of the most significant areas of bioethical interest in the last twenty years. It discusses in more detail one area, namely moral enhancement, which is generating significant contemporary interest. The author argues that so far from being susceptible to new forms of high tech manipulation, either genetic, chemical, surgical or neurological, the only reliable methods of moral enhancement, either now or for the foreseeable future, are either those that have been in human and animal use for millennia, namely socialization, education and parental supervision or those high tech methods that are general in their application. By that is meant those forms of cognitive enhancement that operate across a wide range of cognitive abilities and do not target specifically ‘ethical’ capacities. The paper analyses the work of some of the leading contemporary advocates of moral enhancement and finds that in so far as they identify moral qualities or moral emotions for enhancement they have little prospect of success. PMID:21133978

  2. Normality, therapy, and enhancement.

    PubMed

    Giubilini, Alberto

    2015-07-01

    According to human enhancement advocates, it is morally permissible (and sometimes obligatory) to use biomedical means to modulate or select certain biological traits in order to increase people's welfare, even when there is no pathology to be treated or prevented. Some authors have recently proposed to extend the use of biomedical means to modulate lust, attraction, and attachment. I focus on some conceptual implications of this proposal, particularly with regard to bioconservatives' understanding of the notions of therapy and enhancement I first explain what makes the proposal of medicalizing love interesting and unique, compared to the other forms of bioenhancement usually advocated. I then discuss how the medicalization of love bears on the more general debate on human enhancement, particularly with regard to the key notion of "normality" that is commonly used to define the therapy-enhancement distinction. This analysis suggests that the medicalization of love, in virtue of its peculiarity, requires bioconservatives to reconsider their way of understanding and applying the notions of "therapy" and "enhancement." More in particular, I show that, because a non-arbitrary and value-free notion of "therapy" cannot be applied to the case of love, bioconservatives have the burden of either providing some new criterion that could be used for drawing a line between permissible and impermissible medicalization, or demonstrating that under no circumstances-including the cases in which love is already acknowledged to require medical intervention-can love fall within the domain of medicine. PMID:26059959

  3. Rituals enhance consumption.

    PubMed

    Vohs, Kathleen D; Wang, Yajin; Gino, Francesca; Norton, Michael I

    2013-09-01

    Four experiments tested the novel hypothesis that ritualistic behavior potentiates and enhances ensuing consumption--an effect found for chocolates, lemonade, and even carrots. Experiment 1 showed that participants who engaged in ritualized behavior, compared with those who did not, evaluated chocolate as more flavorful, valuable, and deserving of behavioral savoring. Experiment 2 demonstrated that random gestures do not boost consumption as much as ritualistic gestures do. It further showed that a delay between a ritual and the opportunity to consume heightens enjoyment, which attests to the idea that ritual behavior stimulates goal-directed action (to consume). Experiment 3 found that performing a ritual oneself enhances consumption more than watching someone else perform the same ritual, suggesting that personal involvement is crucial for the benefits of rituals to emerge. Finally, Experiment 4 provided direct evidence of the underlying process: Rituals enhance the enjoyment of consumption because of the greater involvement in the experience that they prompt. PMID:23863754

  4. Human freedom and enhancement.

    PubMed

    Heilinger, Jan-Christoph; Crone, Katja

    2014-02-01

    Ideas about freedom and related concepts like autonomy and self-determination play a prominent role in the moral debate about human enhancement interventions. However, there is not a single understanding of freedom available, and arguments referring to freedom are simultaneously used to argue both for and against enhancement interventions. This gives rise to misunderstandings and polemical arguments. The paper attempts to disentangle the different distinguishable concepts, classifies them and shows how they relate to one another in order to allow for a more structured and clearer debate. It concludes in identifying the individual underpinnings and the social conditions of choice and decision-making as particularly salient dimensions of freedom in the ethical debate about human enhancement. PMID:23519909

  5. Degraded document image enhancement

    NASA Astrophysics Data System (ADS)

    Agam, G.; Bal, G.; Frieder, G.; Frieder, O.

    2007-01-01

    Poor quality documents are obtained in various situations such as historical document collections, legal archives, security investigations, and documents found in clandestine locations. Such documents are often scanned for automated analysis, further processing, and archiving. Due to the nature of such documents, degraded document images are often hard to read, have low contrast, and are corrupted by various artifacts. We describe a novel approach for the enhancement of such documents based on probabilistic models which increases the contrast, and thus, readability of such documents under various degradations. The enhancement produced by the proposed approach can be viewed under different viewing conditions if desired. The proposed approach was evaluated qualitatively and compared to standard enhancement techniques on a subset of historical documents obtained from the Yad Vashem Holocaust museum. In addition, quantitative performance was evaluated based on synthetically generated data corrupted under various degradation models. Preliminary results demonstrate the effectiveness of the proposed approach.

  6. Enhanced condensation heat transfer

    NASA Astrophysics Data System (ADS)

    Michel, J. W.; Murphy, R. W.

    1980-07-01

    Work has centered on optimizing the design variables associated with fluted surfaces on vertical tubes and comparing the tube performance with available enhanced tubes either for vertical or horizontal operation. Data with seven fluids including a hydrocarbon, fluorocarbons, and ammonia condensing on up to 30 different tubes were obtained. Data for tubes of different effective lengths (1/2 to 4 ft) and inclination were also obtained. The primary conclusion is that the best fluted tubes can provide an enhancement in condensation coefficient by a factor of approximately 6 over smooth vertical tube performance and a factor of approximately 2 over the best enhanced commercial tubes either operating vertically or horizontally. These data, together with field test data, have formed the basis for designing two prototype condensers, one for the 60 kWe Raft River, Idaho, pilot plant and one for the 500 kWe East Mesa, California, direct contact demonstration plant.

  7. Surface Enhanced Quantum Control

    NASA Astrophysics Data System (ADS)

    Rangan, Chitra

    2013-05-01

    Miniaturization of quantum technologies have led to physics that require the marriage of atomic physics and nanomaterials science. Some of the resulting areas of research are hybrid quantum devices, single-molecule spectroscopies, table-top intense field generators, etc. I will present an area of research that I dub ``Surface-enhanced quantum control'' that is an exciting way of controlling light and nanomatter. By combining the electromagnetic enhancement properties of plasmonic nanomaterials with the modification of the atomic properties, we can achieve an unprecedented level of control over quantum dynamics. I will present examples of surface-enhanced state purification, in which quantum states near metal nanostructures can be rapidly purified by the application of a weak near-resonant control field. We gratefully acknowledge support from the NSERC Discovery Grant Program and the NSERC Strategic Network for Bioplasmonic Systems.

  8. Fiber enhanced Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Frosch, T.; Yan, D.; Hanf, S.; Popp, J.

    2014-05-01

    Fiber enhanced Raman sensing is presented for versatile and extremely sensitive analysis of pharmaceutical drugs and biogenic gases. Elaborated micro-structured optical fibers guide the light with very low losses within their hollow core and provide at the same time a miniaturized sample container for the analytes. Thus, fiber enhanced Raman spectroscopy (FERS) allows for chemically selective detection of minimal sample amounts with high sensitivity. Two examples are presented in this contribution: (i) the detection of picomolar concentrations of pharmaceutical drugs; and (ii) the analysis of biogenic gases within a complex mixture of gases with analytical sensitivities in the ppm range.

  9. Low Vision Enhancement System

    NASA Technical Reports Server (NTRS)

    1995-01-01

    NASA's Technology Transfer Office at Stennis Space Center worked with the Johns Hopkins Wilmer Eye Institute in Baltimore, Md., to incorporate NASA software originally developed by NASA to process satellite images into the Low Vision Enhancement System (LVES). The LVES, referred to as 'ELVIS' by its users, is a portable image processing system that could make it possible to improve a person's vision by enhancing and altering images to compensate for impaired eyesight. The system consists of two orientation cameras, a zoom camera, and a video projection system. The headset and hand-held control weigh about two pounds each. Pictured is Jacob Webb, the first Mississippian to use the LVES.

  10. Biomedical enhancements as justice.

    PubMed

    Nam, Jeesoo

    2015-02-01

    Biomedical enhancements, the applications of medical technology to make better those who are neither ill nor deficient, have made great strides in the past few decades. Using Amartya Sen's capability approach as my framework, I argue in this article that far from being simply permissible, we have a prima facie moral obligation to use these new developments for the end goal of promoting social justice. In terms of both range and magnitude, the use of biomedical enhancements will mark a radical advance in how we compensate the most disadvantaged members of society. PMID:24117708

  11. Teaching to Enhance Research

    ERIC Educational Resources Information Center

    Harland, Tony

    2016-01-01

    In this paper, I present a conceptual argument for "teaching-led research" in which university lecturers construct courses that directly and positively influence their research, while at the same time, safeguard and enhance the student experience. A research-pedagogy for higher education considers the link between teaching and research,…

  12. Electrostatically Enhanced Vortex Separator

    NASA Technical Reports Server (NTRS)

    Collins, Earl R.

    1993-01-01

    Proposed device removes fine particles from high-pressure exhaust gas of chemical reactor. Negatively charged sectors on rotating disks in vortex generator attracts positively charged particles from main stream of exhaust gas. Electrostatic charge enhances particle-separating action of vortex. Gas without particles released to atmosphere.

  13. Music Enhances Learning.

    ERIC Educational Resources Information Center

    Campabello, Nicolette; De Carlo, Mary Jane; O'Neil, Jean; Vacek, Mary Jill

    An action research project implemented musical strategies to affect and enhance student recall and memory. The target population was three suburban elementary schools near a major midwestern city: (1) a kindergarten classroom contained 32-38 students; (2) a second grade classroom contained 23 students and five Individualized Education Program…

  14. Enhancing Learning and Thinking.

    ERIC Educational Resources Information Center

    Mulcahy, Robert F., Ed.; And Others

    This book presents 16 papers on programs and approaches that have been developed around the world to enhance learning and thinking skills for children and adults. Papers are divided among three main sections focussing respectively on issues and applications, specific applications to school content, and assessment and evaluation. Papers have the…

  15. Potato germplasm enhancement

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Madison USDA-ARS Germplasm Enhancement Program focuses on the development of parents for breeding programs by putting novel valuable traits into adapted, fertile germplasm. The first germplasm release from this program is five clones with resistance to cold sweetening. These clones are named M1-...

  16. Enhanced oil recovery

    SciTech Connect

    Brigand, G.; Kragen, H.

    1982-10-12

    Application of an agent for the enhanced oil recovery by means of an aqueous solution capable of increasing the viscosity of the solution is disclosed. Said agent consists of a mixture of a xanthan salt of a trivalent metal, iron or aluminum, with a complexant for the ion of the trivalent metal.

  17. Measuring and Enhancing Creativity

    ERIC Educational Resources Information Center

    Mahboub, Kamyar C.; Portillo, Margaret B.; Liu, Yinhui; Chandraratna, Susantha

    2004-01-01

    The purpose of this study was to assess ways by which creativity may be enhanced in a design-oriented course. In order to demonstrate the validity of the approach, a statistically based study was employed. Additionally, the experiment was replicated in two design-oriented fields at the University of Kentucky. These fields were civil engineering…

  18. Cognition-Enhancing Drugs

    PubMed Central

    Mehlman, Maxwell J

    2004-01-01

    New drugs that enhance cognition in cognitively healthy individuals present difficult public policy challenges. While their use is not inherently unethical, steps must be taken to ensure that they are safe, that they are widely available to promote equality of opportunity, and that individuals are free to decide whether or not to use them. PMID:15330974

  19. Enhancing Learning in Science.

    ERIC Educational Resources Information Center

    Boylan, Colin

    1988-01-01

    Reviews the theoretical framework of instructional programs and the emphasis on enhancing formal reasoning ability. Investigates the effect of an instructional program using inquiry-based learning in pre-service science teacher education students. Reports that the promotion of formal reasoning abilities may be achieved through the five-phase…

  20. Does Powerpoint enhance learning?

    PubMed

    Penciner, Rick

    2013-03-01

    The ubiquitous nature of PowerPoint begs the question, does PowerPoint enhance learning? This narrative explores the evidence for the effectiveness of PowerPoint and multimedia presentations in learning and information processing. Practical recommendations are provided for presentations. PMID:23458142

  1. Investigations into Character Enhancement.

    ERIC Educational Resources Information Center

    Hartoonian, H. Michael

    2001-01-01

    Presents six different investigations of character enhancement that attempts to answer three questions: (1) who are you; (2) what is your destination; and (3) who is your captain? Intends to build relationships among ideas such as perspective taking, seeing and making connections with the other, and understanding more about ethical development.…

  2. Enhancing Employee Skills.

    ERIC Educational Resources Information Center

    1999

    This document contains four symposium papers on enhancing employee skills. "The Effect of Study Skills Training Intervention on United States Air Force Aeromedical Apprentices" (John C. Griffith) demonstrates how study skills intervention resulted in a significant increase in the end-of-course scores of a sample of 90 randomly selected Air Force…

  3. Payload Documentation Enhancement Project

    NASA Technical Reports Server (NTRS)

    Brown, Betty G.

    1999-01-01

    In late 1998, the Space Shuttle Program recognized a need to revitalize its payload accommodations documentation. As a result a payload documentation enhancement project was initiated to review and update payload documentation and improve the accessibility to that documentation by the Space Shuttle user community.

  4. Oral Skills Enhance Learning.

    ERIC Educational Resources Information Center

    Jensen, J. Vernon

    1980-01-01

    Twelve methods to enhance the learning of college students and at the same time increase their oral communication skills and classroom participation are presented. They include: facilitators of class discussions, triadic critiques of students' essays, panel discussions, forum periods, debates, and manuscript reading. (JMD)

  5. Piezoelectrically Enhanced Photocathodes

    NASA Technical Reports Server (NTRS)

    Beach, Robert A.; Nikzad, Shouleh; Bell, Lloyd Douglas; Strittmatter, Robert

    2011-01-01

    Doping of photocathodes with materials that have large piezoelectric coefficients has been proposed as an alternative means of increasing the desired photoemission of electrons. Treating cathode materials to increase emission of electrons is called "activation" in the art. It has been common practice to activate photocathodes by depositing thin layers of suitable metals (usually, cesium). Because cesium is unstable in air, fabrication of cesiated photocathodes and devices that contain them must be performed in sealed tubes under vacuum. It is difficult and costly to perform fabrication processes in enclosed, evacuated spaces. The proposed piezoelectrically enhanced photocathodes would have electron-emission properties similar to those of cesiated photocathodes but would be stable in air, and therefore could be fabricated more easily and at lower cost. Candidate photocathodes include nitrides of elements in column III of the periodic table . especially compounds of the general formula Al(x)Ga(1.x)N (where 0< or = x < or =.1). These compounds have high piezoelectric coefficients and are suitable for obtaining response to ultraviolet light. Fabrication of a photocathode according to the proposal would include inducement of strain in cathode layers during growth of the layers on a substrate. The strain would be induced by exploiting structural mismatches among the various constituent materials of the cathode. Because of the piezoelectric effect in this material, the strain would give rise to strong electric fields that, in turn, would give rise to a high concentration of charge near the surface. Examples of devices in which piezoelectrically enhanced photocathodes could be used include microchannel plates, electron- bombarded charge-coupled devices, image tubes, and night-vision goggles. Piezoelectrically enhanced photocathode materials could also be used in making highly efficient monolithic photodetectors. Highly efficient and stable piezoelectrically enhanced

  6. Hypothalamic POMC Deficiency Improves Glucose Tolerance Despite Insulin Resistance by Increasing Glycosuria.

    PubMed

    Chhabra, Kavaljit H; Adams, Jessica M; Fagel, Brian; Lam, Daniel D; Qi, Nathan; Rubinstein, Marcelo; Low, Malcolm J

    2016-03-01

    Hypothalamic proopiomelanocortin (POMC) is essential for the physiological regulation of energy balance; however, its role in glucose homeostasis remains less clear. We show that hypothalamic arcuate nucleus (Arc)POMC-deficient mice, which develop severe obesity and insulin resistance, unexpectedly exhibit improved glucose tolerance and remain protected from hyperglycemia. To explain these paradoxical phenotypes, we hypothesized that an insulin-independent pathway is responsible for the enhanced glucose tolerance. Indeed, the mutant mice demonstrated increased glucose effectiveness and exaggerated glycosuria relative to wild-type littermate controls at comparable blood glucose concentrations. Central administration of the melanocortin receptor agonist melanotan II in mutant mice reversed alterations in glucose tolerance and glycosuria, whereas, conversely, administration of the antagonist Agouti-related peptide (Agrp) to wild-type mice enhanced glucose tolerance. The glycosuria of ArcPOMC-deficient mice was due to decreased levels of renal GLUT 2 (rGLUT2) but not sodium-glucose cotransporter 2 and was associated with reduced renal catecholamine content. Epinephrine treatment abolished the genotype differences in glucose tolerance and rGLUT2 levels, suggesting that reduced renal sympathetic nervous system (SNS) activity is the underlying mechanism for the observed glycosuria and improved glucose tolerance in ArcPOMC-deficient mice. Therefore, the ArcPOMC-SNS-rGLUT2 axis is potentially an insulin-independent therapeutic target to control diabetes. PMID:26467632

  7. Orographic enhancement of snowfall.

    PubMed

    Dore, A J; Choularton, T W; Fowler, D; Crossley, A

    1992-01-01

    Field studies have been conducted at a hill site in Scotland to measure the variation with altitude of wet deposition by snowfall. The results showed that, due to wind drift effects, snowflakes were captured very inefficiently by snow collectors. It was therefore not possible to measure an increase in precipitation with altitude. The average concentrations of principal ions dissolved in the snow water were calculated over a two-month period. The results showed that the concentrations increased by factors of between 1.4 and 1.9 with an altitude rise of 400 m. A model of the orographic enhancement of snowfall by the seeder-feeder effect showed that the orographic enhancements of precipitation and pollutant deposition were significantly greater for snowfall than for rainfall. The wind drift of snow crystals and the evaporation of precipitation in dry valley air were important in determining the patterns of deposition. PMID:15092031

  8. Academic Enhancement site.

    PubMed

    DeJong, Judith A; Holder, Stanley R

    2006-01-01

    This off-reservation boarding school serves over 600 students in grades 4-12; approximately 85% of the students reside in campus dormitories. After having documented significant improvement on a number of outcomes during a previous High Risk Youth Prevention demonstration grant, the site submitted a Therapeutic Residential Model proposal, requesting funding to continue successful elements developed under the demonstration grant and to expand mental health services. The site received Therapeutic Residential Model funding for school year 2001-2002. Once funds were received, the site chose to shift Therapeutic Residential Model funds to an intensive academic enhancement effort. While not in compliance with the Therapeutic Residential Model initiative and therefore not funded in subsequent years, this site created the opportunity to enhance the research design by providing a naturally occurring placebo condition at a site with extensive cross-sectional data baselines that addressed issues related to current federal educational policies. PMID:17602403

  9. Superposition Enhanced Nested Sampling

    NASA Astrophysics Data System (ADS)

    Martiniani, Stefano; Stevenson, Jacob D.; Wales, David J.; Frenkel, Daan

    2014-07-01

    The theoretical analysis of many problems in physics, astronomy, and applied mathematics requires an efficient numerical exploration of multimodal parameter spaces that exhibit broken ergodicity. Monte Carlo methods are widely used to deal with these classes of problems, but such simulations suffer from a ubiquitous sampling problem: The probability of sampling a particular state is proportional to its entropic weight. Devising an algorithm capable of sampling efficiently the full phase space is a long-standing problem. Here, we report a new hybrid method for the exploration of multimodal parameter spaces exhibiting broken ergodicity. Superposition enhanced nested sampling combines the strengths of global optimization with the unbiased or athermal sampling of nested sampling, greatly enhancing its efficiency with no additional parameters. We report extensive tests of this new approach for atomic clusters that are known to have energy landscapes for which conventional sampling schemes suffer from broken ergodicity. We also introduce a novel parallelization algorithm for nested sampling.

  10. Microbial enhanced oil recovery

    SciTech Connect

    Finnerty, W.R.; Singer, M.E.

    1983-06-01

    Microbial enhanced oil recovery (MEOR) attempts to exploit the metabolic processes of microorganisms to increase oil production from reservoirs of marginal oil productivity. MEOR can be achieved by direct stimulation of existing microflora within the reservoir, introduction of specialized microroganisms, or above ground use of bioproducts as chemically enhanced oil recovery agents. Reservoir microbiology, the biotransformation of crude oil, and bioproducts applicable to EOR all need further study. Xanthan and polyacrylamine have been applied to EOR, but with some problems. Other selected polysaccharides for which reasonable data bases exist are listed. Some tests on injection of microorganisms, CEOR use, and use of biosurfactants (bacteria that reduces the viscosity of crude oil) are reviewed. The status of MEOR currently resides at a basic level of research and developement.

  11. Image enhancement by holography.

    NASA Technical Reports Server (NTRS)

    Stroke, G. W.

    1973-01-01

    The speed of the holographic image deblurring method has recently been further enhanced by a new speed in the realization of the powerful holographic image-deblurring filter. The filter makes it possible to carry out the deblurring, in the optical computer used, in times of the order of one second. The experimental achievements using the holographic image-enhancement method are illustrated with examples ranging from out-of-focus or motion-blurred photographs, including 'amateur' photos recorded on Polaroid film, to the sharpening of the best available electron micrographs of viruses. Images recorded with X-rays, notably from rocket-borne photos of the sun, and out-of-focus photographs from cameras in NASA satellites have been similarly deblurred.

  12. Enhanced magnetocaloric effect material

    DOEpatents

    Lewis, Laura J. H.

    2006-07-18

    A magnetocaloric effect heterostructure having a core layer of a magnetostructural material with a giant magnetocaloric effect having a magnetic transition temperature equal to or greater than 150 K, and a constricting material layer coated on at least one surface of the magnetocaloric material core layer. The constricting material layer may enhance the magnetocaloric effect by restriction of volume changes of the core layer during application of a magnetic field to the heterostructure. A magnetocaloric effect heterostructure powder comprising a plurality of core particles of a magnetostructural material with a giant magnetocaloric effect having a magnetic transition temperature equal to or greater than 150 K, wherein each of the core particles is encapsulated within a coating of a constricting material is also disclosed. A method for enhancing the magnetocaloric effect within a giant magnetocaloric material including the step of coating a surface of the magnetocaloric material with a constricting material is disclosed.

  13. Enhanced Microfluidic Electromagnetic Measurements

    NASA Technical Reports Server (NTRS)

    Giovangrandi, Laurent (Inventor); Ricco, Antonio J. (Inventor); Kovacs, Gregory (Inventor)

    2015-01-01

    Techniques for enhanced microfluidic impedance spectroscopy include causing a core fluid to flow into a channel between two sheath flows of one or more sheath fluids different from the core fluid. Flow in the channel is laminar. A dielectric constant of a fluid constituting either sheath flow is much less than a dielectric constant of the core fluid. Electrical impedance is measured in the channel between at least a first pair of electrodes. In some embodiments, enhanced optical measurements include causing a core fluid to flow into a channel between two sheath flows of one or more sheath fluids different from the core fluid. An optical index of refraction of a fluid constituting either sheath flow is much less than an optical index of refraction of the core fluid. An optical property is measured in the channel.

  14. Lignite Fuel Enhancement

    SciTech Connect

    Charles Bullinger

    2006-02-03

    This 6th quarterly Technical Progress Report for the Lignite Fuel Enhancement Project summarizes activities from October 1st through December 31st of 2005. It also summarizes the subsequent purchasing activity and dryer/process construction. Hypothesis remains the same. We will be able to dry lignite an increment to benefit the performance of and reduce emissions from a coal burning electric power generating station.

  15. Digital Enhancement Of Pneumothoraces

    NASA Astrophysics Data System (ADS)

    Cocklin, M.; Kaye, G.; Kerr, I.; Lams, P.

    1982-11-01

    If a patient presents with symptoms indicative of a pneumothorax it is improbable that it would not be detected in a chest radiograph. However, detection on the radiograph can be difficult and a small pneumothorax may be missed when there is no clinical suspicion of its presence. This report presents some methods by which the characteristic pneumothorax edge may be enhanced by digital image processing. Various examples are given.

  16. Enhanced Rescue Lift Capability

    NASA Technical Reports Server (NTRS)

    Young, Larry A.

    2007-01-01

    The evolving and ever-increasing demands of emergency response and disaster relief support provided by rotorcraft dictate, among other things, the development of enhanced rescue lift capability for these platforms. This preliminary analysis is first-order in nature but provides considerable insight into some of the challenges inherent in trying to effect rescue using a unique form of robotic rescue device deployed and operated from rotary-wing aerial platforms.

  17. LIGNITE FUEL ENHANCEMENT

    SciTech Connect

    Charles Bullinger

    2004-10-29

    This 1st quarterly Technical Progress Report for the Lignite Fuel Enhancement Project explains what has transpired since Great River Energy was selected to negotiate the Cooperative agreement in February of 2003. The report will summarize Pre-award activities and any other activity since signature of the contract on July 9th of this year. It also summarizes the subsequent purchasing activity and final dryer/process design up to September 30th of 2004.

  18. Skin penetration enhancers.

    PubMed

    Lane, Majella E

    2013-04-15

    The skin has evolved to prevent excessive water loss from the internal organs and to limit the ability of xenobiotics and hazardous substances to enter the body. Notwithstanding this barrier function, a number of strategies have been developed by scientists to deliver drugs to and through the skin. The aim of this review is to consider the various types of chemical penetration enhancers (CPEs) which have been investigated in the scientific literature. Potential pathways for CPEs to exert their action are examined with reference to the physical chemistry of passive skin transport. The emphasis is on those studies which have focussed on human and porcine skin because of the limitations associated with skin permeation data collated from other species. Where known, the mechanisms of action of these compounds are also discussed. Examples of enhancers used in commercial topical and transdermal formulations are provided. It is proposed that overall the effects of CPEs on the skin barrier may best be explained by a Diffusion-Partition-Solubility theory. Finally, some of the limitations of studies in the literature are considered and the importance of monitoring the fate of the penetration enhancer as well as the active is highlighted. PMID:23462366

  19. Sleep for cognitive enhancement

    PubMed Central

    Diekelmann, Susanne

    2014-01-01

    Sleep is essential for effective cognitive functioning. Loosing even a few hours of sleep can have detrimental effects on a wide variety of cognitive processes such as attention, language, reasoning, decision making, learning and memory. While sleep is necessary to ensure normal healthy cognitive functioning, it can also enhance performance beyond the boundaries of the normal condition. This article discusses the enhancing potential of sleep, mainly focusing on the domain of learning and memory. Sleep is known to facilitate the consolidation of memories learned before sleep as well as the acquisition of new memories to be learned after sleep. According to a widely held model this beneficial effect of sleep relies on the neuronal reactivation of memories during sleep that is associated with sleep-specific brain oscillations (slow oscillations, spindles, ripples) as well as a characteristic neurotransmitter milieu. Recent research indicates that memory processing during sleep can be boosted by (i) cueing memory reactivation during sleep; (ii) stimulating sleep-specific brain oscillations; and (iii) targeting specific neurotransmitter systems pharmacologically. Olfactory and auditory cues can be used, for example, to increase reactivation of associated memories during post-learning sleep. Intensifying neocortical slow oscillations (the hallmark of slow wave sleep (SWS)) by electrical or auditory stimulation and modulating specific neurotransmitters such as noradrenaline and glutamate likewise facilitates memory processing during sleep. With this evidence in mind, this article concludes by discussing different methodological caveats and ethical issues that should be considered when thinking about using sleep for cognitive enhancement in everyday applications. PMID:24765066

  20. Chemically enhanced oil recovery

    SciTech Connect

    Nelson, R.C.

    1989-03-01

    Yet when conducted according to present state of the art, chemical flooding (i.e., micellar/polymer flooding, surfactant/polymer flooding, surfactant flooding) can mobilize more residual crude oil than any other method of enhanced oil recovery. It also is one of the most expensive methods of enhanced oil recovery. This contribution will describe some of the technology that comprises the state of the art technology that must be adhered to if a chemical flood is to be successful. Although some of the efforts to reduce cost and other points are discussed, the principle focus is on technical considerations in designing a good chemical flooding system. The term chemical flooding is restricted here to methods of enhanced oil recovery that employs a surfactant, either injected into the oil reservoir or generated in situ, primarily to reduce oil-water interfacial tension. Hence, polymer-water floods for mobility or profile control, steam foams, and carbon dioxide foams are excluded. Some polymer considerations are mentioned because they apply to providing mobility control for chemical flooding systems.

  1. Enhance separations with electricity

    SciTech Connect

    Muralidhara, H.S.

    1994-05-01

    To satisfy growing environmental regulations, control energy costs, or just to stay competitive, one must improve existing separation technologies and make them more efficient. New challenges in food processing and requirements for novel purification technologies in the biotech industry also will require more efficient separation techniques. This paper discusses some enhanced separation processes based on the application of an electric field in the combined-fields approach. In a combined-fields approach, the emphasis is on the generation of additional driving forces to work simultaneously with the conventional driving force of the process. Here the authors concentrate on the application of an electric field to generate the additional driving force.

  2. Enhanced recovery of petroleum

    SciTech Connect

    Buinicky, E.P.; Estes, J.H.

    1980-09-16

    An enhanced oil recovery method comprising injecting an aqueous ammonium bisulfite (NH/sub 4/HSO/sub 3/) solution into a petroleum-bearing earth formation, heating said injected aqueous solution to a temperature in the range of about 120*-300* F., or higher in the presence of said petroleum-bearing earth formation, flowing said aqueous solution through said petroleum bearing earth formation to drive petroleum to a recovery well, and producing increased amounts of petroleum from said earth formation through said recovery well.

  3. Enhancing transgender health care.

    PubMed Central

    Lombardi, E

    2001-01-01

    As awareness of transgender men and women grows among health care educators, researchers, policymakers, and clinicians of all types, the need to create more inclusive settings also grows. Greater sensitivity and relevant information and services are required in dealing with transgender men and women. These individuals need their identities to be recognized as authentic, they need better access to health care resources, and they need education and prevention material appropriate to their experience. In addition, a need exists for activities designed to enhance understanding of transgender health issues and to spur innovation. PMID:11392924

  4. Enhanced by Frost

    NASA Technical Reports Server (NTRS)

    2005-01-01

    30 September 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows outcrops of south polar layered terrain. Their appearance in this July 2005 springtime image is enhanced by bright patches of carbon dioxide frost. The frost is left over from the previous southern winter season; by summer, the frost would be gone.

    Location near: 84.6oS, 203.5oW Image width: width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Spring

  5. Cell Growth Enhancement

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Exogene Corporation uses advanced technologies to enhance production of bio-processed substances like proteins, antibiotics and amino acids. Among them are genetic modification and a genetic switch. They originated in research for Jet Propulsion Laboratory. Extensive experiments in cell growth through production of hemoglobin to improve oxygen supply to cells were performed. By improving efficiency of oxygen use by cells, major operational expenses can be reduced. Greater product yields result in decreased raw material costs and more efficient use of equipment. A broad range of applications is cited.

  6. Graphene-enhanced nanorefrigerants.

    PubMed

    Ozturk, Serdar; Hassan, Yassin A; Ugaz, Victor M

    2013-01-21

    Recent reports that a host liquid's thermal properties can be augmented by dispersal of small quantities of nanoparticles have stimulated intense interest as an intriguing avenue to produce advanced heat transfer fluids. But effects are challenging to exploit in practical settings because it is difficult to prepare refrigerant-based dispersions displaying sufficient long-term stability. Moreover, the most dramatic enhancements in thermal conductivity obtained using anisotropic nanomaterials (e.g., carbon nanotubes) are achieved at the expense of a severe viscosity increase. Here we overcome these limitations by introducing a robust surfactant-mediated dispersal method that enables stable suspensions containing a range of nanomaterials to be straightforwardly prepared as additives to ordinary commercial refrigerants. We apply this approach to formulate a new class of nanorefrigerants containing graphene nanosheets that uniquely match the superior thermal conductivity enhancements attained in carbon nanotube suspensions without their accompanying viscosity penalty. These suspensions can be directly substituted for conventional refrigerants to inexpensively achieve increased efficiency in many thermal management applications. PMID:23229852

  7. Computer enhancement of radiographs

    NASA Technical Reports Server (NTRS)

    Dekaney, A.; Keane, J.; Desautels, J.

    1973-01-01

    Examination of three relevant noise processes and the image degradation associated with Marshall Space Flight Center's (MSFC) X-ray/scanning system was conducted for application to computer enhancement of radiographs using MSFC's digital filtering techniques. Graininess of type M, R single coat and R double coat X-ray films was quantified as a function of density level using root-mean-square (RMS) granularity. Quantum mottle (including film grain) was quantified as a function of the above film types, exposure level, specimen material and thickness, and film density using RMS granularity and power spectral density (PSD). For various neutral-density levels the scanning device used in digital conversion of radiographs was examined for noise characteristics which were quantified by RMS granularity and PSD. Image degradation of the entire pre-enhancement system (MG-150 X-ray device; film; and optronics scanner) was measured using edge targets to generate modulation transfer functions (MTF). The four parameters were examined as a function of scanning aperture sizes of approximately 12.5 25 and 50 microns.

  8. Acoustically enhanced heat transport.

    PubMed

    Ang, Kar M; Yeo, Leslie Y; Friend, James R; Hung, Yew Mun; Tan, Ming K

    2016-01-01

    We investigate the enhancement of heat transfer in the nucleate boiling regime by inducing high frequency acoustic waves (f ∼ 10(6) Hz) on the heated surface. In the experiments, liquid droplets (deionized water) are dispensed directly onto a heated, vibrating substrate. At lower vibration amplitudes (ξs ∼ 10(-9) m), the improved heat transfer is mainly due to the detachment of vapor bubbles from the heated surface and the induced thermal mixing. Upon increasing the vibration amplitude (ξs ∼ 10(-8) m), the heat transfer becomes more substantial due to the rapid bursting of vapor bubbles happening at the liquid-air interface as a consequence of capillary waves travelling in the thin liquid film between the vapor bubble and the air. Further increases then lead to rapid atomization that continues to enhance the heat transfer. An acoustic wave displacement amplitude on the order of 10(-8) m with 10(6) Hz order frequencies is observed to produce an improvement of up to 50% reduction in the surface temperature over the case without acoustic excitation. PMID:26827343

  9. Acoustically enhanced heat transport

    NASA Astrophysics Data System (ADS)

    Ang, Kar M.; Yeo, Leslie Y.; Friend, James R.; Hung, Yew Mun; Tan, Ming K.

    2016-01-01

    We investigate the enhancement of heat transfer in the nucleate boiling regime by inducing high frequency acoustic waves (f ˜ 106 Hz) on the heated surface. In the experiments, liquid droplets (deionized water) are dispensed directly onto a heated, vibrating substrate. At lower vibration amplitudes (ξs ˜ 10-9 m), the improved heat transfer is mainly due to the detachment of vapor bubbles from the heated surface and the induced thermal mixing. Upon increasing the vibration amplitude (ξs ˜ 10-8 m), the heat transfer becomes more substantial due to the rapid bursting of vapor bubbles happening at the liquid-air interface as a consequence of capillary waves travelling in the thin liquid film between the vapor bubble and the air. Further increases then lead to rapid atomization that continues to enhance the heat transfer. An acoustic wave displacement amplitude on the order of 10-8 m with 106 Hz order frequencies is observed to produce an improvement of up to 50% reduction in the surface temperature over the case without acoustic excitation.

  10. Surfactant-enhanced bioremediation

    SciTech Connect

    Churchill, P.F.; Dudley, R.J.; Churchill, S.A.

    1995-12-31

    This study was undertaken to examine the effect of three structurally related, non-ionic surfactants, Triton X-45, Triton X-100 and Triton X-165, as well as the oleophilic fertilizer, Inipol EAP 22, on the rate of biodegradation of phenanthrene by pure bacterial cultures. Each surfactant dramatically increased the apparent aqueous solubility of phenanthrene. Model studies were conducted to investigate the ability of these surfactants to enhance the rate of transport and uptake of polycyclic aromatic hydrocarbons into bacterial cells, and to assess the impact that increasing the aqueous solubility of hydrocarbons has on their rate of biodegradation. The results indicate that increasing the apparent aqueous solubility of hydrocarbons can lead to enhanced biodegradation rates by two Pseudomonas saccharophila strains. However, the experiments also suggest that some surfactants can inhibit aromatic hydrocarbon biodegradation by certain bacteria. The data also support the hypothesis that surface-active components present in the oleophilic fertilizer formulation, Inipol EAP 22, may have significantly contributed to the positive results reported in tests of remedial agent impact on bioremediation, which was used as a supplemental clean-up technology on Exxon Valdez crude oil-contaminated Alaskan beaches.

  11. Telemetry-Enhancing Scripts

    NASA Technical Reports Server (NTRS)

    Maimone, Mark W.

    2009-01-01

    Scripts Providing a Cool Kit of Telemetry Enhancing Tools (SPACKLE) is a set of software tools that fill gaps in capabilities of other software used in processing downlinked data in the Mars Exploration Rovers (MER) flight and test-bed operations. SPACKLE tools have helped to accelerate the automatic processing and interpretation of MER mission data, enabling non-experts to understand and/or use MER query and data product command simulation software tools more effectively. SPACKLE has greatly accelerated some operations and provides new capabilities. The tools of SPACKLE are written, variously, in Perl or the C or C++ language. They perform a variety of search and shortcut functions that include the following: Generating text-only, Event Report-annotated, and Web-enhanced views of command sequences; Labeling integer enumerations with their symbolic meanings in text messages and engineering channels; Systematic detecting of corruption within data products; Generating text-only displays of data-product catalogs including downlink status; Validating and labeling of commands related to data products; Performing of convenient searches of detailed engineering data spanning multiple Martian solar days; Generating tables of initial conditions pertaining to engineering, health, and accountability data; Simplified construction and simulation of command sequences; and Fast time format conversions and sorting.

  12. Computer enhanced digital angiography.

    PubMed

    Vas, R; Diamond, G A; Levisman, J A; Nakano, F H; Neidorf, B S; Rose, R M; Whiting, J S; Forrester, J S

    1982-05-01

    A new computer image enhancement technique was employed on cardiac images of 10 dogs and 7 patients to demonstrate the feasibility of an on-line automatic delineation of the left ventricular endocardial silhouette with a peripheral venous injection of contrast material while simultaneously reducing the x-ray dosage. This technique employs a very fast analog-to-digital conversion system capable of digitizing on-line video frames. By storing and continuously updating the first 30 video frames and then subtracting each incoming frame from this memory, most of the background is eliminated leaving only the contrast filled ventricle. Using calibrated densitometric measurements, we found that iodine concentrations in the human left ventricle following venous injection of 40 ml Renografin-76 (25 ml/s), peaked at 4.3 +/- 0.3 mg/ml (mean +/- SD) compared to 14.8 +/- 0.8 mg/ml following direct injection of 40 ml at 13 ml/s (p less than 0.001). The computer enhanced venous-injected images had an optical contrast 14 times greater than that of the unenhanced direct left ventriculogram. This increase in optical contrast provided unambiguous subjective definition of the endocardial borders. This technique is applicable to both central and peripheral contrast injection whereby high quality images can be obtained at approximately 98% reduction in radiation (5 mA, 65-85 kV), allowing performance of serial studies. PMID:7094444

  13. Direct vs. Indirect Moral Enhancement.

    PubMed

    Schaefer, G Owen

    2015-09-01

    Moral enhancement is an ostensibly laudable project. Who wouldn't want people to become more moral? Still, the project's approach is crucial. We can distinguish between two approaches for moral enhancement: direct and indirect. Direct moral enhancements aim at bringing about particular ideas, motives or behaviors. Indirect moral enhancements, by contrast, aim at making people more reliably produce the morally correct ideas, motives or behaviors without committing to the content of those ideas, motives and/or actions. I will argue, on Millian grounds, that the value of disagreement puts serious pressure on proposals for relatively widespread direct moral enhancement. A more acceptable path would be to focus instead on indirect moral enhancements while staying neutral, for the most part, on a wide range of substantive moral claims. I will outline what such indirect moral enhancement might look like, and why we should expect it to lead to general moral improvement. PMID:26412738

  14. Enhanced oil recovery process

    SciTech Connect

    Martin, A. B.; Jackson, E. J.

    1985-10-15

    An improved portable, versatile, modular, above-ground system and process for generating combustion gases, principally nitrogen and carbon dioxide, and steam, for removing particulate matter and corrosive components from the combustion gases, and for injecting the purified nitrogen and CO/sub 2/, and steam, individually or in selected mixtures, at controlled temperatures and pressures into a subterranean formation bearing hydrocarbons to enhance the recovery thereof. The system includes a high-pressure combustion reactor for efficient generation of combustion gases at the required rates and at pressures up to about 8000 psi and temperatures up to about 4500/sup 0/ F. The reactor is water-jacketed but lined with refractory material to minimize soot formation. Combustion chamber temperature is reduced to a safe level by water injection with the fuel.

  15. Enhanced Geothermal Systems

    SciTech Connect

    Jeanloz, R.; Stone, H.

    2013-12-31

    DOE, through the Geothermal Technologies Office (GTO) within the Office of Energy Efficiency and Renewable Energy, requested this study, identifying a focus on: i) assessment of technologies and approaches for subsurface imaging and characterization so as to be able to validate EGS opportunities, and ii) assessment of approaches toward creating sites for EGS, including science and engineering to enhance permeability and increase the recovery factor. Two days of briefings provided in-depth discussion of a wide range of themes and challenges in EGS, and represented perspectives from industry, government laboratories and university researchers. JASON also contacted colleagues from universities, government labs and industry in further conversations to learn the state of the field and potential technologies relevant to EGS.

  16. Enhanced oil recovery system

    DOEpatents

    Goldsberry, Fred L.

    1989-01-01

    All energy resources available from a geopressured geothermal reservoir are used for the production of pipeline quality gas using a high pressure separator/heat exchanger and a membrane separator, and recovering waste gas from both the membrane separator and a low pressure separator in tandem with the high pressure separator for use in enhanced oil recovery, or in powering a gas engine and turbine set. Liquid hydrocarbons are skimmed off the top of geothermal brine in the low pressure separator. High pressure brine from the geothermal well is used to drive a turbine/generator set before recovering waste gas in the first separator. Another turbine/generator set is provided in a supercritical binary power plant that uses propane as a working fluid in a closed cycle, and uses exhaust heat from the combustion engine and geothermal energy of the brine in the separator/heat exchanger to heat the propane.

  17. Teacher Enhancement Institute

    NASA Technical Reports Server (NTRS)

    Marshall-Bradley, Tina

    1994-01-01

    During the 1980's, a period of intense concern over educational quality in the United States, few indicators of U.S. student achievement garnered the interest of policy makers and pundits as successfully as the results of international testing in mathematics and science. This concern was so great that as a part of the Goals 2000 initiative, President George Bush indicated that 'By the year 2000, U.S. students should be first in the world in mathematics and science.' The Clinton Administration is placing a major emphasis, not only on rigorous academic standards and creating a new system for assessing students' progress, but also including professional development as a major focus. The argument being that teachers need more sustained, intensive training to prepare them to teach to higher standards. Executive order 12821 mandates that national laboratories 'assist in the mathematics and science education of our Nation's students, teachers, parents and the public by establishing programs at their agency to provide for training elementary and secondary school teachers to improve their knowledge of mathematics and science'. These and other issues led to the development of ideas for a project that addresses the need for excellence in mathematics, science and technology instruction. In response to these initiatives the NASA/LaRC Teacher Enhancement Institute was proposed. The TEI incorporated systemic reform perspectives, enhanced content knowledge for teachers, and teacher preparation. Emphasis was also placed on recruiting those educators who teach in impoverished urban school districts with at-risk student populations who have been traditionally under represented in science, mathematics, technology and engineering. Participants in the Teacher Enhancement Institute were 37 teachers from grades K-8, teaching in Region 2 in the state of Virginia, as well as 2 preservice teachers from Norfolk State University and one teacher from Dublin, Virginia, where a Science

  18. Attention enhances feature integration.

    PubMed

    Paul, Liza; Schyns, Philippe G

    2003-08-01

    Perceptual processing delays between attribute dimensions (e.g. color, form and motion) [Proceedings of the Royal Society of London Series B 264 (1997) 1407] have been attributed to temporal processing asynchronies resulting from functional segregation of visual information [Science 240 (1988) 740]. In addition, several lines of evidence converge to suggest that attention plays an important role in the integration of functionally processed information. However, exactly how attention modulates the temporal integration of information remains unclear. Here, we examined how attention modulates the integration of color and form into a unitary perception. Results suggest that attending to the location of an object enhances the integration of its defining attributes by speeding up the perceptual processing of each attribute dimension. Moreover, the perceptual asynchrony between attributes remains constant across attended and unattended conditions because attention seems to offer each processing dimension an equal processing advantage. PMID:12826102

  19. Digitally Enhanced Heterodyne Interferometry

    NASA Technical Reports Server (NTRS)

    Shaddock, Daniel; Ware, Brent; Lay, Oliver; Dubovitsky, Serge

    2010-01-01

    Spurious interference limits the performance of many interferometric measurements. Digitally enhanced interferometry (DEI) improves measurement sensitivity by augmenting conventional heterodyne interferometry with pseudo-random noise (PRN) code phase modulation. DEI effectively changes the measurement problem from one of hardware (optics, electronics), which may deteriorate over time, to one of software (modulation, digital signal processing), which does not. DEI isolates interferometric signals based on their delay. Interferometric signals are effectively time-tagged by phase-modulating the laser source with a PRN code. DEI improves measurement sensitivity by exploiting the autocorrelation properties of the PRN to isolate only the signal of interest and reject spurious interference. The properties of the PRN code determine the degree of isolation.

  20. Cavity enhanced atomic magnetometry

    PubMed Central

    Crepaz, Herbert; Ley, Li Yuan; Dumke, Rainer

    2015-01-01

    Atom sensing based on Faraday rotation is an indispensable method for precision measurements, universally suitable for both hot and cold atomic systems. Here we demonstrate an all-optical magnetometer where the optical cell for Faraday rotation spectroscopy is augmented with a low finesse cavity. Unlike in previous experiments, where specifically designed multipass cells had been employed, our scheme allows to use conventional, spherical vapour cells. Spherical shaped cells have the advantage that they can be effectively coated inside with a spin relaxation suppressing layer providing long spin coherence times without addition of a buffer gas. Cavity enhancement shows in an increase in optical polarization rotation and sensitivity compared to single-pass configurations. PMID:26481853

  1. Enhanced optical tracking

    NASA Astrophysics Data System (ADS)

    McSheery, Tracy

    2008-04-01

    Enhanced tracking is accomplished by increasing the resolution, frame rate and processing capabilities in tracking dynamic regions of interest for vision applications. In many proven algorithms, the ability to distinguish an object and track it is dependent on the system performance in more than one attribute. We have conducted studies on proven techniques such as Active Appearance Models, Principle Component Analysis and Eigen tracking. All perform better as the camera resolution increases, and camera frame rate increases. Additional opportunities have been observed by combining these techniques, taking advantage of Multicore CPUs, and GPU graphic card processing. Results from an 8 Megapixel commercial sensor combined with a Field Programmable Gate array are presented, and algorithm performance compared with down scaled images of the same scenes, and simulated typical 30 hertz frame rates verses the 120 hertz to 300 hertz typical of this smart camera.

  2. Plasmonic enhanced ultrafast switch.

    SciTech Connect

    Subramania,Ganapathi Subramanian; Reno, John Louis; Passmore, Brandon Scott; Harris, Tom.; Shaner, Eric Arthur; Barrick, Todd A.

    2009-09-01

    Ultrafast electronic switches fabricated from defective material have been used for several decades in order to produce picosecond electrical transients and TeraHertz radiation. Due to the ultrashort recombination time in the photoconductor materials used, these switches are inefficient and are ultimately limited by the amount of optical power that can be applied to the switch before self-destruction. The goal of this work is to create ultrafast (sub-picosecond response) photoconductive switches on GaAs that are enhanced through plasmonic coupling structures. Here, the plasmonic coupler primarily plays the role of being a radiation condenser which will cause carriers to be generated adjacent to metallic electrodes where they can more efficiently be collected.

  3. Photon enhanced thermionic emission

    SciTech Connect

    Schwede, Jared; Melosh, Nicholas; Shen, Zhixun

    2014-10-07

    Photon Enhanced Thermionic Emission (PETE) is exploited to provide improved efficiency for radiant energy conversion. A hot (greater than 200.degree. C.) semiconductor cathode is illuminated such that it emits electrons. Because the cathode is hot, significantly more electrons are emitted than would be emitted from a room temperature (or colder) cathode under the same illumination conditions. As a result of this increased electron emission, the energy conversion efficiency can be significantly increased relative to a conventional photovoltaic device. In PETE, the cathode electrons can be (and typically are) thermalized with respect to the cathode. As a result, PETE does not rely on emission of non-thermalized electrons, and is significantly easier to implement than hot-carrier emission approaches.

  4. Memnonia Fossae (Enhanced Color)

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Tharsis-centered volcanic and tectonic activity resulted in the formation of radial grabens of Memnonia Fossae, which cut materials of the ancient cratered highlands and the relatively young, highland-embaying lava flows from the Tharsis volcanoes. Center of picture is at latitude 16 degrees S., longitude 142 degrees W. The enhanced color version (following decorrelation stretch) reveals a diversity of subtle color variations; many of the color variations may be due to different lava flow units and variable amounts of weathering, possible alteration by water, and eolian redistributions. Viking Orbiter Picture Numbers 41B52 (green) 41B54 (red), and 41B56 (blue) at 198 m/pixel resolution. Picture width is 206 km. North is 119 degrees counter-clockwise from top.

  5. Structure Size Enhanced Histogram

    NASA Astrophysics Data System (ADS)

    Wesarg, Stefan; Kirschner, Matthias

    Direct volume visualization requires the definition of transfer functions (TFs) for the assignment of opacity and color. Multi-dimensional TFs are based on at least two image properties, and are specified by means of 2D histograms. In this work we propose a new type of a 2D histogram which combines gray value with information about the size of the structures. This structure size enhanced (SSE) histogram is an intuitive approach for representing anatomical features. Clinicians — the users we are focusing on — are much more familiar with selecting features by their size than by their gradient magnitude value. As a proof of concept, we employ the SSE histogram for the definition of two-dimensional TFs for the visualization of 3D MRI and CT image data.

  6. Cavity enhanced atomic magnetometry.

    PubMed

    Crepaz, Herbert; Ley, Li Yuan; Dumke, Rainer

    2015-01-01

    Atom sensing based on Faraday rotation is an indispensable method for precision measurements, universally suitable for both hot and cold atomic systems. Here we demonstrate an all-optical magnetometer where the optical cell for Faraday rotation spectroscopy is augmented with a low finesse cavity. Unlike in previous experiments, where specifically designed multipass cells had been employed, our scheme allows to use conventional, spherical vapour cells. Spherical shaped cells have the advantage that they can be effectively coated inside with a spin relaxation suppressing layer providing long spin coherence times without addition of a buffer gas. Cavity enhancement shows in an increase in optical polarization rotation and sensitivity compared to single-pass configurations. PMID:26481853

  7. Cavity enhanced atomic magnetometry

    NASA Astrophysics Data System (ADS)

    Crepaz, Herbert; Ley, Li Yuan; Dumke, Rainer

    2015-10-01

    Atom sensing based on Faraday rotation is an indispensable method for precision measurements, universally suitable for both hot and cold atomic systems. Here we demonstrate an all-optical magnetometer where the optical cell for Faraday rotation spectroscopy is augmented with a low finesse cavity. Unlike in previous experiments, where specifically designed multipass cells had been employed, our scheme allows to use conventional, spherical vapour cells. Spherical shaped cells have the advantage that they can be effectively coated inside with a spin relaxation suppressing layer providing long spin coherence times without addition of a buffer gas. Cavity enhancement shows in an increase in optical polarization rotation and sensitivity compared to single-pass configurations.

  8. Enhanced Identification of Transcriptional Enhancers Provides Mechanistic Insights into Diseases.

    PubMed

    Murakawa, Yasuhiro; Yoshihara, Masahito; Kawaji, Hideya; Nishikawa, Miki; Zayed, Hatem; Suzuki, Harukazu; Fantom Consortium; Hayashizaki, Yoshihide

    2016-02-01

    Enhancers are distal cis-regulatory DNA elements that increase the expression of target genes. Various experimental and computational approaches including chromatin signature profiling have been developed to predict enhancers on a genome-wide scale, although each method has its advantages and disadvantages. Here we overview an emerging method to identify transcribed enhancers at exceedingly high nucleotide resolution based on enhancer RNA transcripts captured by Cap Analysis of Gene Expression (CAGE) technology. We further argue that disease-causative regulatory mutations at enhancers are increasingly recognized, emphasizing the importance of enhancer identification in functional and clinical genomics including, but not limited to, genome-wide association studies (GWASs) and cancer genomics studies. PMID:26780995

  9. Lignite Fuel Enhancement

    SciTech Connect

    Charles Bullinger; Nenad Sarunac

    2010-03-31

    Pulverized coal power plants which fire lignites and other low-rank high-moisture coals generally operate with reduced efficiencies and increased stack emissions due to the impacts of high fuel moisture on stack heat loss and pulverizer and fan power. A process that uses plant waste heat sources to evaporate a portion of the fuel moisture from the lignite feedstock in a moving bed fluidized bed dryer (FBD) was developed in the U.S. by a team led by Great River Energy (GRE). The demonstration was conducted with Department of Energy (DOE) funding under DOE Award Number DE-FC26-04NT41763. The objectives of GRE's Lignite Fuel Enhancement project were to demonstrate reduction in lignite moisture content by using heat rejected from the power plant, apply technology at full scale at Coal Creek Station (CCS), and commercialize it. The Coal Creek Project has involved several stages, beginning with lignite drying tests in a laboratory-scale FBD at the Energy Research Center (ERC) and development of theoretical models for predicting dryer performance. Using results from these early stage research efforts, GRE built a 2 ton/hour pilot-scale dryer, and a 75 ton/hour prototype drying system at Coal Creek Station. Operated over a range of drying conditions, the results from the pilot-scale and prototype-scale dryers confirmed the performance of the basic dryer design concept and provided the knowledge base needed to scale the process up to commercial size. Phase 2 of the GRE's Lignite Fuel Enhancement project included design, construction and integration of a full-scale commercial coal drying system (four FBDs per unit) with Coal Creek Units 1 and 2 heat sources and coal handling system. Two series of controlled tests were conducted at Coal Creek Unit 1 with wet and dried lignite to determine effect of dried lignite on unit performance and emissions. Wet lignite was fired during the first, wet baseline, test series conducted in September 2009. The second test series was performed

  10. Enhanced preliminary assessment

    SciTech Connect

    Not Available

    1992-02-01

    An Enhanced Preliminary Assessment was conducted at Fort Benjamin Harrison (FBH) Indiana, which is located approximately 12 miles from downtown Indianapolis in Lawrence Township, Marion County. FBH contains 2,501 acres, of which approximately 1,069 acres is covered by woodlands. Activities at FBH include administration, training, housing, and support. Sensitive environments at FBH include wetlands, habitat areas for the endangered Indiana bat, endangered plants, and historically and archeologically significant areas. FBH is a U.S. Army Soldier Support Center under the jurisdiction of the U.S. Army Training and Doctrine Command (TRADOC). Based on information obtained during and subsequent to a site visit (15 through 18 October 1991), 36 types of Areas Requiring Environmental Evaluation (AREEs) were identified and grouped by the following categories: Facility Operations; Maintenance/Fueling Operations; Water Treatment Operations; Training Areas; Hazardous Materials Storage/Waste Handling Areas; Sanitary Wastewater Treatment Plants; Storage Tanks; Landfills/Incinerators; Medical Facilities; Burn Pit Areas; Spill Areas; Ammunition Storage; Coal Storage; and Facility-wide AREEs. This report presents a summary of findings for each AREE and recommendations for further action.

  11. FRET enhanced fluorescent nanodiamonds.

    PubMed

    Fudala, Rafal; Raut, Sangram; Maliwal, Badri P; Zerda, T W; Gryczynski, Ignacy; Simanek, Eric; Borejdo, Julian; Rich, Ryan; Akopova, Irina; Gryczynski, Zygmunt

    2014-01-01

    Fluorescent nanodiamonds (FNDs) are one of the new and very promising biocompatible nanomaterials that can be used both as a fluorescence imaging agent and a highly versatile platform for controlled functionalization to target and deliver a wide spectrum of therapeutic agents. Among the remarkable fluorescence properties are excellent photostability, emission between 600-700nm, quantum yield of 1 and moderately long fluorescence lifetimes. However the low absorption cross section of fluorescent (N-V)(-) centers limits FNDs' brightness. In this work we show that an approach based on the Forster resonance energy transfer (FRET) may significantly enhance the fluorescence signal observed from a single ND. We demonstrate that organic dyes (fluorophores) attached to the FND surface can efficiently transfer the excitation energy to (N-V)(-) centers. Multiple dyes positioned in close proximity to the ND facile surface may serve as harvesting antennas transferring excitation energy to the fluorescent centers. We propose that, with the help of some of the functional groups present on the FND surface, we can either directly link flurophores or use scalable dendrimer chemistry to position many organic dyes at a calibrated distance. Also, the remaining multiple functional groups will be still available for particle targeting and drug delivery. This opens a new way for designing a new type of theranostics particles of ultrahigh brightness, high photostability, specific targeting, and high capacity for drug delivery. PMID:22394126

  12. Enhancing young people's awareness.

    PubMed

    Doan Thi Tien

    1995-01-01

    The role of the Vietnam Youth Union (21 million members) is to educate the youth aged 14-28 years about the movement at the grassroots level. Since 1995, it has been entrusted with information, education, and communication (IEC) activities (implemented through the Educational Center for Population, Health, and Development) concerning family planning, the environment, human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS). Mass media, direct communication, Youth Union leading staff, Youth Union cultural and arts activities, and advertisement have been used. 16 newspapers and magazines, a radio program, and a TV program disseminate information for the group. 1000 motivators' groups, 1370 Youth Clubs, and Youth Villages at the commune level work to enhance awareness and to change biased attitudes and habits. Leading staff speak at conferences and seminars that are attended by target groups. Art troupes perform at special local events; plays are organized and videos are shown. The HIV/AIDS information and prevention campaign is of great importance because research findings indicate that many young people believe that only prostitutes and drug addicts can be infected, and that condoms are bad and only for use with prostitutes. There are about 2300 persons infected with HIV in 14 provinces, mostly in the south and central regions. 131 are reported to have developed AIDS. PMID:12320323

  13. Enhancing chemical reactions

    DOEpatents

    Morrey, John R.

    1978-01-01

    Methods of enhancing selected chemical reactions. The population of a selected high vibrational energy state of a reactant molecule is increased substantially above its population at thermal equilibrium by directing onto the molecule a beam of radiant energy from a laser having a combination of frequency and intensity selected to pump the selected energy state, and the reaction is carried out with the temperature, pressure, and concentrations of reactants maintained at a combination of values selected to optimize the reaction in preference to thermal degradation by transforming the absorbed energy into translational motion. The reaction temperature is selected to optimize the reaction. Typically a laser and a frequency doubler emit radiant energy at frequencies of .nu. and 2.nu. into an optical dye within an optical cavity capable of being tuned to a wanted frequency .delta. or a parametric oscillator comprising a non-centrosymmetric crystal having two indices of refraction, to emit radiant energy at the frequencies of .nu., 2.nu., and .delta. (and, with a parametric oscillator, also at 2.nu.-.delta.). Each unwanted frequency is filtered out, and each desired frequency is focused to the desired radiation flux within a reaction chamber and is reflected repeatedly through the chamber while reactants are fed into the chamber and reaction products are removed therefrom.

  14. Enhanced Micellar Catalysis LDRD.

    SciTech Connect

    Betty, Rita G.; Tucker, Mark David; Taggart, Gretchen; Kinnan, Mark K.; Glen, Crystal Chanea; Rivera, Danielle; Sanchez, Andres; Alam, Todd Michael

    2012-12-01

    The primary goals of the Enhanced Micellar Catalysis project were to gain an understanding of the micellar environment of DF-200, or similar liquid CBW surfactant-based decontaminants, as well as characterize the aerosolized DF-200 droplet distribution and droplet chemistry under baseline ITW rotary atomization conditions. Micellar characterization of limited surfactant solutions was performed externally through the collection and measurement of Small Angle X-Ray Scattering (SAXS) images and Cryo-Transmission Electron Microscopy (cryo-TEM) images. Micellar characterization was performed externally at the University of Minnesota's Characterization Facility Center, and at the Argonne National Laboratory Advanced Photon Source facility. A micellar diffusion study was conducted internally at Sandia to measure diffusion constants of surfactants over a concentration range, to estimate the effective micelle diameter, to determine the impact of individual components to the micellar environment in solution, and the impact of combined components to surfactant phase behavior. Aerosolized DF-200 sprays were characterized for particle size and distribution and limited chemical composition. Evaporation rates of aerosolized DF-200 sprays were estimated under a set of baseline ITW nozzle test system parameters.

  15. Waste water filtration enhancement

    SciTech Connect

    Martin, H.L.

    1989-01-01

    Removal of submicron particles from process solutions and waste water is now economically achievable using a new Tyvek{reg sign} media in conventional filtration equipment. This new product greatly enhances filtration and allows use of the much improved filter aids and polymers which were recently developed. It has reduced operating costs and ensures a clean effluent discharge to the environment. This significant technical development is especially important to those who discharge to a small stream with low 7Q10 flow and must soon routinely pass the Toxicity tests that are being required by many States for NPDES permit renewal. The Savannah River Plant produces special nuclear materials for the US Government. Aluminum forming and metal finishing operations in M-Area, that manufacture fuel and target assemblies for the nuclear reactors, discharge to a waste water treatment facility using BAT hydroxide precipitation and filtration. The new Tyvek{reg sign} media and filter aids have achieved 55% less solids in the filtrate discharged to Tims Branch Creek, 15% less hazardous waste (dry filter cake), 150%-370% more filtration capacity, 74% lower materials purchase cost, 10% lower total M-Area manufacturing cost, and have improved safety. Performance with the improved polymers is now being evaluated.

  16. Enhancing geometric reasoning.

    PubMed

    Mistretta, R M

    2000-01-01

    Geometry is an important part of the mathematics curriculum. However, students are not demonstrating strong conceptual knowledge of this subject. The research of Van Hiele and Van Hiele-Geldof has focused on the concept of thinking levels in geometry and the role of instruction in raising levels of thinking. This paper describes a field trial of a supplemental geometry unit intended to raise Van Hiele thinking levels in a group of 23 eighth-grade students by having them become more adept at using higher order thinking skills. Sample questions assessing particular Van Hiele thinking levels and attitudes toward geometry, as well as field-tested activities yielding the most positive results, are presented. Educators can benefit from this application of the Van Hiele model of geometric thinking, since the thought processes involved in learning geometry are explained, along with teaching techniques and tools for assessment. By having teachers become more aware of their students' cognitive skills, attitudes, and misconceptions, teaching practices and student achievement can be enhanced. PMID:11019778

  17. Enhanced target factor analysis.

    PubMed

    Rostami, Akram; Abdollahi, Hamid; Maeder, Marcel

    2016-03-10

    Target testing or target factor analysis, TFA, is a well-established soft analysis method. TFA answers the question whether an independent target test vector measured at the same wavelengths as the collection of spectra in a data matrix can be excluded as the spectrum of one of the components in the system under investigation. Essentially, TFA cannot positively prove that a particular test spectrum is the true spectrum of one of the components, it can, only reject a spectrum. However, TFA will not reject, or in other words TFA will accept, many spectra which cannot be component spectra. Enhanced Target Factor Analysis, ETFA addresses the above problem. Compared with traditional TFA, ETFA results in a significantly narrower range of positive results, i.e. the chance of a false positive test result is dramatically reduced. ETFA is based on feasibility testing as described in Refs. [16-19]. The method has been tested and validated with computer generated and real data sets. PMID:26893084

  18. Enhanced local tomography

    DOEpatents

    Katsevich, Alexander J.; Ramm, Alexander G.

    1996-01-01

    Local tomography is enhanced to determine the location and value of a discontinuity between a first internal density of an object and a second density of a region within the object. A beam of radiation is directed in a predetermined pattern through the region of the object containing the discontinuity. Relative attenuation data of the beam is determined within the predetermined pattern having a first data component that includes attenuation data through the region. In a first method for evaluating the value of the discontinuity, the relative attenuation data is inputted to a local tomography function .function..sub..LAMBDA. to define the location S of the density discontinuity. The asymptotic behavior of .function..sub..LAMBDA. is determined in a neighborhood of S, and the value for the discontinuity is estimated from the asymptotic behavior of .function..sub..LAMBDA.. In a second method for evaluating the value of the discontinuity, a gradient value for a mollified local tomography function .gradient..function..sub..LAMBDA..epsilon. (x.sub.ij) is determined along the discontinuity; and the value of the jump of the density across the discontinuity curve (or surface) S is estimated from the gradient values.

  19. Analog enhancement of radiographic images

    NASA Technical Reports Server (NTRS)

    Baily, N. A.; Nachazel, R. J.

    1976-01-01

    The paper shows how analog methods for edge sharpening, contrast enhancement, and expansion of the range of gray levels of particular interest are effective for easy on-line application to video viewing of X-ray roentgenograms or to fluoroscopy. The technique for analog enhancement of radiographic images is a modified version of the system designed by Fuchs et al. (1972), whereby an all directional second derivative signal called detail signal is used to produce both vertical and horizontal enhancement of the image. Particular attention is given to noise filtration and contrast enhancement. Numerous radiographs supplement the text.

  20. Lignite Fuel Enhancement

    SciTech Connect

    Charles Bullinger

    2007-03-31

    This 11th quarterly Technical Progress Report for the Lignite Fuel Enhancement Project summarizes activities from January 1st through March 31st of 2007. It summarizes the completion of the Prototype testing activity and initial full-scale dryer design, Budget Period 2 activity during that time period. The Design Team completed process design and layouts of air, water, and coal systems. Heyl-Patterson completed dryer drawings and has sent RFPs to several fabricators for build and assembly. Several meetings were held with Barr engineers to finalize arrangement of the drying, air jig, and coal handling systems. Honeywell held meetings do discuss the control system logic and hardware location. By the end of March we had processed nearly 300,000 tons of lignite through the dryer. Outage preparation maintenance activities on a coal transfer hopper restricted operation of the dryer in February and March. The Outage began March 17th. We will not dry coal again until early May when the Outage on Unit No.2 completes. The Budget Period 1 (Phase 1) final report was submitted this quarter. Comments were received from NETL and are being reviewed. The Phase 2 Project Management Plan was submitted to NETL in January 2007. This deliverable also included the Financing Plan. An application for R&D 100 award was submitted in February. The project received an award from the Minnesota Professional Engineering Society's Seven Wonders of Engineering Award and Minnesota ACEC Grand Award in January. To further summarize, the focus this quarter has been on finalizing commercial design and the layout of four dryers behind each Unit. The modification to the coal handling facilities at Coal Creek and incorporation of air jigs to further beneficiate the segregated material the dryers will reject 20 to 30 % of the mercury and sulfur is segregated however this modification will recover the carbon in that stream.

  1. Plasmon Enhanced Photoemission

    SciTech Connect

    Polyakov, Aleksandr

    2012-05-08

    this work, the structure consisted of rectangular nano-grooves (NGs) arranged in a subwavelength grating on a metal surface is presented that provides a dramatic increase in the metal’s absorption, field localization, and field enhancement. When light is polarized perpendicular to the orientation of the grooves a standing SPP wave is excited along the vertical walls in the NGs, that act as Fabry-Perot resonators. By adjusting the geometry of the NGs and the period of the subwavelength grating the resonance can be fine tuned to a desired position, for example, the laser fundamental wavelength, anywhere from the UV to the near infrared (NIR). Two types of gratings are presented: (a) a gold grating with period of 600 nm, and (b) an aluminum-gold grating with a period of 100 nm; both with resonance at 720 nm. In each case, strong on-resonance absorption was observed, with over 98% for grating (b). Unlike the grating-coupled SPP waves, where the angle is well defined by the momentum matching condition, the resonant NGs allow coupling to the standing modes at a range of angles of incidence, referred to as the angular bandwidth. A new model for the on-resonance absorption based on the ensamble action of the NGs is presented that serves as the basis for a design of an NG grating with an ultrawide spectral as well as angular bandwidth. For sample (b), the angular bandwidth is 80 degrees, corresponding to an opening angle of 160 degrees. The photoemission enhancement for such a grating was measured to be seven orders of magnitude for a four-photon photoemission. This is an incredible result demonstrating the power of the plasmonic grating presented, which is an efficient light trapper and field enhancer for a non-linear processes. These results demonstrate that the metal photocathode prepared with a NG grating on the metal surface will provide sufficient pulse charge driven by a 1 μJ 15fs pulsed laser at 800 nm for the optimum FEL operation.

  2. Strategies to Enhance Vocabulary Development.

    ERIC Educational Resources Information Center

    Teal, Tiffany

    Vocabulary knowledge provides a source of prior knowledge and word meaning that can be used to enhance reading comprehension. It is important that teachers be aware and knowledgeable of the many strategies available to enhance vocabulary growth, and also how to teach these strategies to students. These strategies can range from the use of context…

  3. SURFACE ENHANCED SECOND HARMONIC GENERATION

    SciTech Connect

    Chen, C. K.; de Castro, A. R.B.; Shen, Y. R.

    1980-09-01

    Second harmonic generation at a silver-air interface was enhanced due to surface roughness by a factor of 10{sup 4}. The local field enhancement is believed to be responsible for the effect. An unusually broad luminescence background extending far beyond the antiStokes side of the second harmonic was also observed.

  4. Cohen's Conservatism and Human Enhancement.

    PubMed

    Pugh, Jonathan; Kahane, Guy; Savulescu, Julian

    2013-01-01

    In an intriguing essay, G. A. Cohen has defended a conservative bias in favour of existing value. In this paper, we consider whether Cohen's conservatism raises a new challenge to the use of human enhancement technologies. We develop some of Cohen's suggestive remarks into a new line of argument against human enhancement that, we believe, is in several ways superior to existing objections. However, we shall argue that on closer inspection, Cohen's conservatism fails to offer grounds for a strong sweeping objection to enhancement, and may even offer positive support for forms of enhancement that preserve valuable features of human beings. Nevertheless, we concede that Cohen's arguments may suggest some plausible and important constraints on the modality of legitimate and desirable enhancements. PMID:24683311

  5. The Misfortunes of Moral Enhancement.

    PubMed

    Azevedo, Marco Antonio

    2016-10-01

    In Unfit for the Future, Ingmar Persson and Julian Savulescu present a sophisticated argument in defense of the imperative of moral enhancement. They claim that without moral enhancement, the future of humanity is seriously compromised. The possibility of ultimate harm, caused by a dreadful terrorist attack or by a final unpreventable escalation of the present environmental crisis aggravated by the availability of cognitive enhancement, makes moral enhancement a top priority. It may be considered optimistic to think that our present moral capabilities can be successfully improved by means of moral education, moral persuasion, and fear of punishment. So, without moral enhancement, drastic restrictions on human freedom would become the only alternative to prevent those dramatic potential outcomes. In this article, I will try to show that we still have reason to be less pessimistic and that Persson & Savulescu's arguments are fortunately unconvincing. PMID:27473409

  6. One danger of biomedical enhancements.

    PubMed

    Rajczi, Alex

    2008-07-01

    In the near future, our society may develop a vast array of medical enhancements. There is a large debate about enhancements, and that debate has identified many possible harms. This paper describes a harm that has so far been overlooked. Because of some particular features of enhancements, we could come to place more value on them than we actually should. This over-valuation would lead us to devote time, energy, and resources to enhancements that could be better spent somewhere else. That mistake might not be trivial. By spending too much time, energy, and resources on enhancements, we could set back our pursuit of our deepest goals such as living happily and leading ethical lives. PMID:18522592

  7. Lignite Fuel Enhancement

    SciTech Connect

    Charles Bullinger

    2006-04-03

    This 7th quarterly Technical Progress Report for the Lignite Fuel Enhancement Project summarizes activities from January 1st through March 31st of 2006. It also summarizes the subsequent purchasing activity, dryer/process construction, and testing. The Design Team began conferencing again as construction completed and the testing program began. Primary focus this quarter was construction/installation completion. Phase 1 extension recommendation, and subsequent new project estimate, Forms 424 and 4600 were accepted by DOE headquarters. DOE will complete the application and amended contract. All major mechanical equipment was run, checked out, and tested this quarter. All water, air, and coal flow loops were run and tested. The system was run on January 30th, shut down to adjust equipment timing in the control system on the 31st, and run to 75 ton//hour on February 1st. It ran for seven to eight hours per day until March 20th when ''pairs'' testing ( 24 hour running) began. ''Pairs'' involves comparative testing of unit performance with seven ''wet'' pulverizers versus six ''wet'' and one ''dry''. During the interim, more operators were brought up to speed on system operation and control was shifted to the main Unit No.2 Control Room. The system is run now from the Unit control board operator and an equipment operator checks the system during regular rounds or when an alarm needs verification. The flawless start-up is unprecedented in the industry and credit should be made to the diligence and tenacity of Coal Creek maintenance/checkout staff. Great River Energy and Headwaters did not meet to discuss the Commercialization Plan this quarter. The next meeting is pending data from the drying system. Discussions with Basin Electric, Otter Tail, and Dairyland continue and confidentiality secured as we promote dryers in their stations. Lighting and fire protection were completed in January. Invoices No.12 through No.20 are completed and forwarded following preliminary

  8. Enhanced Elliptic Grid Generation

    NASA Technical Reports Server (NTRS)

    Kaul, Upender K.

    2007-01-01

    An enhanced method of elliptic grid generation has been invented. Whereas prior methods require user input of certain grid parameters, this method provides for these parameters to be determined automatically. "Elliptic grid generation" signifies generation of generalized curvilinear coordinate grids through solution of elliptic partial differential equations (PDEs). Usually, such grids are fitted to bounding bodies and used in numerical solution of other PDEs like those of fluid flow, heat flow, and electromagnetics. Such a grid is smooth and has continuous first and second derivatives (and possibly also continuous higher-order derivatives), grid lines are appropriately stretched or clustered, and grid lines are orthogonal or nearly so over most of the grid domain. The source terms in the grid-generating PDEs (hereafter called "defining" PDEs) make it possible for the grid to satisfy requirements for clustering and orthogonality properties in the vicinity of specific surfaces in three dimensions or in the vicinity of specific lines in two dimensions. The grid parameters in question are decay parameters that appear in the source terms of the inhomogeneous defining PDEs. The decay parameters are characteristic lengths in exponential- decay factors that express how the influences of the boundaries decrease with distance from the boundaries. These terms govern the rates at which distance between adjacent grid lines change with distance from nearby boundaries. Heretofore, users have arbitrarily specified decay parameters. However, the characteristic lengths are coupled with the strengths of the source terms, such that arbitrary specification could lead to conflicts among parameter values. Moreover, the manual insertion of decay parameters is cumbersome for static grids and infeasible for dynamically changing grids. In the present method, manual insertion and user specification of decay parameters are neither required nor allowed. Instead, the decay parameters are

  9. Excitation enhancement and extraction enhancement with photonic crystals

    SciTech Connect

    Shapira, Ofer; Soljacic, Marin; Zhen, Bo; Chua, Song-Liang; Lee, Jeongwon; Joannopoulos, John

    2015-03-03

    Disclosed herein is a system for stimulating emission from at least one an emitter, such as a quantum dot or organic molecule, on the surface of a photonic crystal comprising a patterned dielectric substrate. Embodiments of this system include a laser or other source that illuminates the emitter and the photonic crystal, which is characterized by an energy band structure exhibiting a Fano resonance, from a first angle so as to stimulate the emission from the emitter at a second angle. The coupling between the photonic crystal and the emitter may result in spectral and angular enhancement of the emission through excitation and extraction enhancement. These enhancement mechanisms also reduce the emitter's lasing threshold. For instance, these enhancement mechanisms enable lasing of a 100 nm thick layer of diluted organic molecules solution with reduced threshold intensity. This reduction in lasing threshold enables more efficient organic light emitting devices and more sensitive molecular sensing.

  10. Environmental engineering education enhancement

    NASA Astrophysics Data System (ADS)

    Caporali, E.

    2012-04-01

    Since higher education plays a central role in the development of both human beings and modern societies, enhancing social, cultural and economic development, active citizenship, ethical values and expertises for a sustainable growth, environment respectful, the European Commission promotes a wide range of programmes. Among the EC programmes, the TEMPUS - Trans European Mobility Programme for University Studies, with the support of the DG EAC of the European Commission, has contributed to many aspects of general interest for higher education. Curricula harmonization, LifeLong Learning Programme development, ICT use, quality assessment, accreditation, innovation learning methods, growth of networks of institutions trusting each other, are the focused aspects. Such a solid cooperation framework is surely among the main outcomes of the TEMPUS Projects leaded by the University of Firenze UNIFI (Italy), DEREC - Development of Environment and Resources Engineering Curriculum (2005-2008), and its spin-off DEREL - Development of Environment and Resources Engineering Learning (2010-2013), and VICES - Videoconferencing Educational Services (2009-2012). DEREC and DEREL TEMPUS projects, through the co-operation of Universities in Italy, Austria, Germany, Greece, Macedonia, Albania and Serbia, are aimed at the development of first and second level curricula in "Environment and Resources Engineering" at the Ss. Cyril and Methodius University - UKIM Skopje (MK). In the DEREC Project the conditions for offering a joint degree title in the field of Environmental Engineering between UNIFI and UKIM Skopje were fulfilled and a shared educational programme leading to the mutual recognition of degree titles was defined. The DEREL project, as logical continuation of DEREC, is aimed to introduce a new, up-to-date, postgraduate second level curriculum in Environment and Resources Engineering at UKIM Skopje, University of Novi Sad (RS) and Polytechnic University of Tirana (AL). following

  11. Male chest enhancement: pectoral implants.

    PubMed

    Benito-Ruiz, J; Raigosa, J M; Manzano-Surroca, M; Salvador, L

    2008-01-01

    The authors present their experience with the pectoral muscle implant for male chest enhancement in 21 patients. The markings and technique are thoroughly described. The implants used were manufactured and custom made. The candidates for implants comprised three groups: group 1 (18 patients seeking chest enhancement), group 2 (1 patient with muscular atrophy), and group 3 (2 patients with muscular injuries). Because of the satisfying results obtained, including significant enhancement of the chest contour and no major complications, this technique is used for an increasing number of male cosmetic surgeries. PMID:17676376

  12. Ultrasound Despeckling for Contrast Enhancement

    PubMed Central

    Tay, Peter C.; Garson, Christopher D.; Acton, Scott T.; Hossack, John A.

    2010-01-01

    Images produced by ultrasound systems are adversely hampered by a stochastic process known as speckle. A despeckling method based upon removing outlier is proposed. The method is developed to contrast enhance B-mode ultrasound images. The contrast enhancement is with respect to decreasing pixel variations in homogeneous regions while maintaining or improving differences in mean values of distinct regions. A comparison of the proposed despeckling filter is compared with the other well known despeckling filters. The evaluations of despeckling performance are based upon improvements to contrast enhancement, structural similarity, and segmentation results on a Field II simulated image and actual B-mode cardiac ultrasound images captured in vivo. PMID:20227984

  13. Ultrasound despeckling for contrast enhancement.

    PubMed

    Tay, Peter C; Garson, Christopher D; Acton, Scott T; Hossack, John A

    2010-07-01

    Images produced by ultrasound systems are adversely hampered by a stochastic process known as speckle. A despeckling method based upon removing outlier is proposed. The method is developed to contrast enhance B-mode ultrasound images. The contrast enhancement is with respect to decreasing pixel variations in homogeneous regions while maintaining or improving differences in mean values of distinct regions. A comparison of the proposed despeckling filter is compared with the other well known despeckling filters. The evaluations of despeckling performance are based upon improvements to contrast enhancement, structural similarity, and segmentation results on a Field II simulated image and actual B-mode cardiac ultrasound images captured in vivo. PMID:20227984

  14. Tip enhanced Raman scattering: plasmonic enhancements for nanoscale chemical analysis

    NASA Astrophysics Data System (ADS)

    Schultz, Zachary D.; Marr, James M.; Wang, Hao

    2014-04-01

    Tip enhanced Raman scattering (TERS) is an emerging technique that uses a metalized scanning probe microscope tip to spatially localize electric fields that enhances Raman scattering enabling chemical imaging on nanometer dimensions. Arising from the same principles as surface enhanced Raman scattering (SERS), TERS offers unique advantages associated with controling the size, shape, and location of the enhancing nanostructure. In this article we discuss the correlations between current understanding of SERS and how this relates to TERS, as well as how TERS provides new understanding and insights. The relationship between plasmon resonances and Raman enhancements is emphasized as the key to obtaining optimal TERS results. Applications of TERS, including chemical analysis of carbon nanotubes, organic molecules, inorganic crystals, nucleic acids, proteins, cells and organisms, are used to illustrate the information that can be gained. Under ideal conditions TERS is capable of single molecule sensitivity and sub-nanometer spatial resolution. The ability to control plasmonic enhancements for chemical analysis suggests new experiments and opportunities to understand molecular composition and interactions on the nanoscale.

  15. Geothermal Permeability Enhancement - Final Report

    SciTech Connect

    Joe Beall; Mark Walters

    2009-06-30

    The overall objective is to apply known permeability enhancement techniques to reduce the number of wells needed and demonstrate the applicability of the techniques to other undeveloped or under-developed fields. The Enhanced Geothermal System (EGS) concept presented in this project enhances energy extraction from reduced permeability zones in the super-heated, vapor-dominated Aidlin Field of the The Geysers geothermal reservoir. Numerous geothermal reservoirs worldwide, over a wide temperature range, contain zones of low permeability which limit the development potential and the efficient recovery of heat from these reservoirs. Low permeability results from poorly connected fractures or the lack of fractures. The Enhanced Geothermal System concept presented here expands these technologies by applying and evaluating them in a systematic, integrated program.

  16. Moderate eugenics and human enhancement.

    PubMed

    Selgelid, Michael J

    2014-02-01

    Though the reputation of eugenics has been tarnished by history, eugenics per se is not necessarily a bad thing. Many advocate a liberal new eugenics--where individuals are free to choose whether or not to employ genetic technologies for reproductive purposes. Though genetic interventions aimed at the prevention of severe genetic disorders may be morally and socially acceptable, reproductive liberty in the context of enhancement may conflict with equality. Enhancement could also have adverse effects on utility. The enhancement debate requires a shift in focus. What the equality and/or utility costs of enhancement will be is an empirical question. Rather than philosophical speculation, more social science research is needed to address it. Philosophers, meanwhile, should address head-on the question of how to strike a balance between liberty, equality, and utility in cases of conflict (in the context of genetics). PMID:23728949

  17. WEATHERABILITY OF ENHANCED DEGRADABLE PLASTICS

    EPA Science Inventory

    The main objective of this study was to assess the performance and the associated variability of several selected enhanced degradable plastic materials under a variety of different exposure conditions. ther objectives were to identify the major products formed during degradation ...

  18. Platelets enhance neutrophil transendothelial migration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Platelets are increasingly recognized as important mediators of inflammation in addition to thrombosis. While platelets have been shown to promote neutrophil (PMN) adhesion to endothelium in various inflammatory models, it is unclear whether platelets enhance neutrophil transmigration across inflame...

  19. Ultrasonic enhancement of battery diffusion.

    PubMed

    Hilton, R; Dornbusch, D; Branson, K; Tekeei, A; Suppes, G J

    2014-03-01

    It has been demonstrated that sonic energy can be harnessed to enhance convection in Galvanic cells during cyclic voltammetry; however, the practical value of this approach is limited due to the lack of open volumes for convection patterns to develop in most batteries. This study evaluates the ability of ultrasonic waves to enhance diffusion in membrane separators commonly used in sandwich-architecture batteries. Studies include the measuring of open-circuit performance curves to interpret performances in terms of reductions in concentration overpotentials. The use of a 40 kHz sonicator bath can consistently increase the voltage of the battery and reduce overpotential losses up to 30%. This work demonstrates and quantifies battery enhancement due to enhanced diffusion made possible with ultrasonic energy. PMID:24210813

  20. WEATHERABILITY OF ENHANCED DEGRADABLE PLASTICS

    EPA Science Inventory

    The main objective of this study was to assess the performance and the asociated variability of several selected enhanced degradable plastic materials under a variety of different exposure conditions. Other objectives were to identify the major products formed during degradation ...

  1. Chemically enhanced in situ recovery

    SciTech Connect

    Sale, T.; Pitts, M.; Wyatt, K.

    1996-08-01

    Chemically enhanced recovery is a promising alternative to current technologies for management of subsurface releases of organic liquids. Through the inclusion of surfactants, solvents, polymers, and/or alkaline agents to a waterflood, the transport of targeted organic compounds can be increased and rates of recovery enhanced. By far, the vast majority of work done in the field of chemically enhanced recovery has been at a laboratory scale. The following text focuses on chemically enhanced recovery from a field application perspective with emphasis given to chlorinated solvents in a low permeability setting. While chlorinated solvents are emphasized, issues discussed are also relevant to organic liquids less dense than water such as petroleum products. Topics reviewed include: (1) Description of technology; (2) General technology considerations; (3) Low permeability media considerations; (4) Cost and reliability considerations; (5) Commercial availability; and (6) Case histories. Through this paper an appreciation is developed of both the potential and limitations of chemically enhanced recovery. Excluded from the scope of this paper is the in situ destruction of organic compounds through processes such as chemical or biological oxidation, chemically enhanced recovery of inorganic compounds, and ex situ soil treatment processes. 11 refs., 2 figs., 1 tab.

  2. Electret enhances transdermal drug permeation.

    PubMed

    Narasimha Sathyanarayana Murthy, Narasimha Sathyanarayana; Boguda, Vishwanath Anantharamaiah; Payasada, Kotrappa

    2008-01-01

    Electrets are polymeric discs that carry semi permanent electrostatic charge. These provide electrostatic potentials in the range of 500 to 3,000 V. In the current work, the effect of electret exposure on the skin permeability was investigated. Transdermal transport studies were carried out across porcine epidermis in Franz diffusion cells. Salicylic acid, fluorescein labeled dextrans (FD) and propofol were used as test diffusants. The ability of electret to enhance the transdermal permeation of salicylic acid was studied in vivo in Sprague Dawley rats. Electret enhanced the permeability of porcine epidermis to salicylic acid. The enhancement factor increased with the surface voltage, however it was independent of the nature of charge (+ or -). The enhancement by electret was cut-off at 1 kDa, as interpreted by studying the transport of FD. The electrets decreased the permeability of skin to propofol, a lipophilic diffusant. Pretreatment of porcine epidermis enhanced the iontophoretic transport of salicylic acid, whereas the same did not enhance the transport of salicylic acid by electroporation. It is most likely that electret exposure renders the lipid domains of stratum corneum more permeable to polar molecules and in turn hampers the diffusion of nonpolar diffusant. PMID:18175950

  3. Discovery and Structure-Guided Optimization of Diarylmethanesulfonamide Disrupters of Glucokinase-Glucokinase Regulatory Protein (GK-GKRP) Binding: Strategic Use of a N → S (nN → σ*S-X) Interaction for Conformational Constraint.

    PubMed

    Pennington, Lewis D; Bartberger, Michael D; Croghan, Michael D; Andrews, Kristin L; Ashton, Kate S; Bourbeau, Matthew P; Chen, Jie; Chmait, Samer; Cupples, Rod; Fotsch, Christopher; Helmering, Joan; Hong, Fang-Tsao; Hungate, Randall W; Jordan, Steven R; Kong, Ke; Liu, Longbin; Michelsen, Klaus; Moyer, Carolyn; Nishimura, Nobuko; Norman, Mark H; Reichelt, Andreas; Siegmund, Aaron C; Sivits, Glenn; Tadesse, Seifu; Tegley, Christopher M; Van, Gwyneth; Yang, Kevin C; Yao, Guomin; Zhang, Jiandong; Lloyd, David J; Hale, Clarence; St Jean, David J

    2015-12-24

    The HTS-based discovery and structure-guided optimization of a novel series of GKRP-selective GK-GKRP disrupters are revealed. Diarylmethanesulfonamide hit 6 (hGK-hGKRP IC50 = 1.2 μM) was optimized to lead compound 32 (AMG-0696; hGK-hGKRP IC50 = 0.0038 μM). A stabilizing interaction between a nitrogen atom lone pair and an aromatic sulfur system (nN → σ*S-X) in 32 was exploited to conformationally constrain a biaryl linkage and allow contact with key residues in GKRP. Lead compound 32 was shown to induce GK translocation from the nucleus to the cytoplasm in rats (IHC score = 0; 10 mg/kg po, 6 h) and blood glucose reduction in mice (POC = -45%; 100 mg/kg po, 3 h). X-ray analyses of 32 and several precursors bound to GKRP were also obtained. This novel disrupter of GK-GKRP binding enables further exploration of GKRP as a potential therapeutic target for type II diabetes and highlights the value of exploiting unconventional nonbonded interactions in drug design. PMID:26551034

  4. Enhanced sludge washing evaluation plan

    SciTech Connect

    Jensen, R.D.

    1994-09-01

    The Tank Waste Remediation System (TWRS) Program mission is to store, treat, and immobilize highly radioactive Hanford Site waste (current and future tank waste and the strontium/cesium capsules) in an environmentally sound, safe, and cost-effective manner. The scope of the TWRS Waste Pretreatment Program is to treat tank waste and separate that waste into HLW and LLW fractions and provide additional treatment as required to feed LLW and HLW immobilization facilities. Enhanced sludge washing was chosen as the baseline process for separating Hanford tank waste sludge. Section 1.0 briefly discusses the purpose of the evaluation plan and provides the background that led to the choice of enhanced sludge washing as the baseline process. Section 2.0 provides a brief summary of the evaluation plan details. Section 3.0 discusses, in some detail, the technical work planned to support the evaluation of enhanced sludge washing. Section 4.0 briefly discusses the potential important of policy issues to the evaluation. Section 5.0 discusses the methodology to be used in the evaluation process. Section 6.0 summarizes the milestones that have been defined to complete the enhanced sludge washing evaluation and provides a summary schedule to evaluate the performance of enhanced sludge washing. References are identified in Section 7.0, and additional schedule and milestone information is provided in the appendices.

  5. Enhanced video viewing from metadata

    NASA Astrophysics Data System (ADS)

    Janevski, Angel; McGee, Thomas; Agnihotri, Lalitha; Dimitrova, Nevenka

    2001-11-01

    Current advanced television concepts envision data broadcasting along with the video stream, which is used by interactive applications at the client end. In this case, these applications do not proactively personalize the experience and may not allow user requests for additional information. We propose content enhancement using automatic retrieval of additional information based on video content and user interests. Our paper describes Video Retriever Genie, a system that enhances content with additional information based on metadata that provides semantics for the content. The system is based on a digital TV (Philips TriMedia) platform. We enhance content through user queries that define information extraction tasks that retrieve information from the Web. We present several examples of content enhancement such as additional movie character/actor information, financial information and weather alerts. Our system builds a bridge between the traditional TV viewing and the domain of personal computing and Internet. The boundaries between these domains are dissolving and this system demonstrates one effective approach for content enhancement. In addition, we illustrate our discussion with examples from two existing standards - MPEG-7 and TV-Anytime.

  6. Contrast-Enhanced Endoscopic Ultrasound

    PubMed Central

    Dietrich, Christoph F.; Sharma, M.; Hocke, M.

    2012-01-01

    The European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) introduced guidelines on the use of contrast-enhanced ultrasound (CEUS) in 2004. This EFSUMB-document focused mainly on liver applications. However, new applications extending beyond the liver were developed thereafter. Increased interest in recent years in CEUS technique and in the application of CEUS in novel fields like endoscopic ultrasound (EUS) has revolutionized indications and applications. As a result, the EFSUMB initiated a new update of the guidelines in 2011 to include this additional knowledge. Some of the contrast-enhanced EUS (CE-EUS) indications are established, whereas others are preliminary; these latter indications are categorized as emergent CEUS applications since the available evidence is insufficient for general recommendation. This article focuses on the use of CE-EUS in various clinical settings. The reader will get an overview of current indications and possible applications of CE-EUS. This involves the introduction of different contrast studies including color Doppler techniques (known as contrast-enhanced high mechanical index endosonography or CEHMI-EUS) as well as more modern high-resolution contrast-enhanced techniques (known as contrast-enhanced low mechanical index endosonography or CELMI EUS). PMID:24949350

  7. In vitro evidence supports the presence of glucokinase-independent glucosensing mechanisms in hypothalamus and hindbrain of rainbow trout.

    PubMed

    Otero-Rodiño, Cristina; Velasco, Cristina; Álvarez-Otero, Rosa; López-Patiño, Marcos A; Míguez, Jesús M; Soengas, José L

    2016-06-01

    We previously obtained evidence in rainbow trout for the presence and response to changes in circulating levels of glucose (induced by intraperitoneal hypoglycaemic and hyperglycaemic treatments) of glucosensing mechanisms based on liver X receptor (LXR), mitochondrial production of reactive oxygen species (ROS) leading to increased expression of uncoupling protein 2 (UCP2), and sweet taste receptor in the hypothalamus, and on sodium/glucose co-transporter 1 (SGLT-1) in hindbrain. However, these effects of glucose might be indirect. Therefore, we evaluated the response of parameters related to these glucosensing mechanisms in a first experiment using pooled sections of hypothalamus and hindbrain incubated for 6 h at 15°C in modified Hanks' medium containing 2, 4 or 8 mmol l(-1) d-glucose. The responses observed in some cases were consistent with glucosensing capacity. In a second experiment, pooled sections of hypothalamus and hindbrain were incubated for 6 h at 15°C in modified Hanks' medium with 8 mmol l(-1) d-glucose alone (control) or containing 1 mmol l(-1) phloridzin (SGLT-1 antagonist), 20 µmol l(-1) genipin (UCP2 inhibitor), 1 µmol l(-1) trolox (ROS scavenger), 100 µmol l(-1) bezafibrate (T1R3 inhibitor) and 50 µmol l(-1) geranyl-geranyl pyrophosphate (LXR inhibitor). The response observed in the presence of these specific inhibitors/antagonists further supports the proposal that critical components of the different glucosensing mechanisms are functioning in rainbow trout hypothalamus and hindbrain. PMID:27026717

  8. Effects of piragliatin, a glucokinase activator, on fasting and postprandial plasma glucose in patients with type 2 diabetes mellitus.

    PubMed

    Zhi, Jianguo; Zhai, Suoping

    2016-02-01

    To assess the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of piragliatin, a double-blind, randomized, placebo-controlled, multiple-ascending-doses study was conducted in patients with type 2 diabetes mellitus (T2D). Fifty-nine T2D patients were given piragliatin or placebo in a dose-escalation design as a single dose on day 1 followed by multiple doses on days 3 through 8 at doses of 10, 25, 50, 100, and 200 mg twice a day (BID) as well as 200 mg every day (QD). Blood and urine samples were collected for PK analysis. PD assessments included plasma glucose, insulin, C-peptide, glucagon, and GLP-1. Piragliatin exposure was dose proportional without appreciable accumulation or food effect. Piragliatin treatment at steady state yielded dose-dependent reductions up to 32.5% and 35.5% for the highest dose in fasting and postprandial plasma glucose. Piragliatin was well tolerated. Mild or moderate hypoglycemia with rapid recovery after sugar-containing drinks or scheduled meals was the only dose-limiting adverse event. It is concluded that multiple doses of piragliatin consistently showed rapid, dose-dependent glucose reduction of fasting and postprandial plasma glucose in T2D patients. PMID:26183686

  9. Moral enhancement requires multiple virtues.

    PubMed

    Hughes, James J

    2015-01-01

    Some of the debates around the concept of moral enhancement have focused on whether the improvement of a single trait, such as empathy or intelligence, would be a good in general, or in all circumstances. All virtue theories, however, both secular and religious, have articulated multiple virtues that temper and inform one another in the development of a mature moral character. The project of moral enhancement requires a reengagement with virtue ethics and contemporary moral psychology to develop an empirically grounded model of the virtues and a fuller model of character development. Each of these virtues may be manipulable with electronic, psychopharmaceutical, and genetic interventions. A set of interdependent virtues is proposed, along with some of the research pointing to ways such virtues could be enhanced. PMID:25473861

  10. Sexual dimorphism and human enhancement.

    PubMed

    Casal, Paula

    2013-12-01

    Robert Sparrow argues that because of women's longer life expectancy philosophers who advocate the genetic modification of human beings to enhance welfare rather than merely supply therapy are committed to favouring the selection of only female embryos, an implication he deems sufficiently implausible to discredit their position. If Sparrow's argument succeeds, then philosophers who advocate biomedical moral enhancement also seem vulnerable to a similar charge because of men's greater propensity for various forms of harmful wrongdoing. This paper argues there are various flaws in Sparrow's argument that render it unsuccessful. The paper also examines whether dimorphism reduction is a more desirable outcome than male elimination, thereby further illustrating the difficulties besetting the distinction between therapy and enhancement. PMID:22962068

  11. Microwave enhanced sintering of ceramics

    SciTech Connect

    Wroe, F.C.R.; Rowley, A.T.

    1995-12-31

    It is now well known that microwave dielectric heating can be used to increase the Wintering rates and to reduce the sintering times of ceramic materials. However, the nature of the mechanism causing this enhanced sintering is still far from understood, with many workers attributing the effect to a reduction in the activation energy even though there is no real physical basis for this assumption. Although the mechanism is not understood, many results have indicated that the effect is non thermal in nature, i.e. the enhancement would not be reproduced if conventional heat could be applied in exactly the same way (volumetrically) as microwave heat. By careful control of the relative proportions of microwave and conventional heating, it has been possible to separate the thermal (heating) effects from the non-thermal effects. This paper discusses the results obtained, and show that they are consistent with recent theories of enhanced diffusion.

  12. Retinex enhancement of infrared images.

    PubMed

    Li, Ying; He, Renjie; Xu, Guizhi; Hou, Changzhi; Sun, Yunyan; Guo, Lei; Rao, Liyun; Yan, Weili

    2008-01-01

    With the ability of imaging the temperature distribution of body, infrared imaging is promising in diagnostication and prognostication of diseases. However the poor quality of the raw original infrared images prevented applications and one of the essential problems is the low contrast appearance of the imagined object. In this paper, the image enhancement technique based on the Retinex theory is studied, which is a process that automatically retrieve the visual realism to images. The algorithms, including Frackle-McCann algorithm, McCann99 algorithm, single-scale Retinex algorithm, multi-scale Retinex algorithm and multi-scale Retinex algorithm with color restoration, are experienced to the enhancement of infrared images. The entropy measurements along with the visual inspection were compared and results shown the algorithms based on Retinex theory have the ability in enhancing the infrared image. Out of the algorithms compared, MSRCR demonstrated the best performance. PMID:19163132

  13. Human enhancement: The new eugenics

    PubMed Central

    Vizcarrondo, Felipe E.

    2014-01-01

    Supporters of human enhancement through genetic and other reproductive technologies claim that the new liberal eugenics, based on science and individual consent differs from the old eugenics which was unscientific and coercive. Supporters claim it is the parent's moral obligation to produce the best children possible. At this time, a defective gene that is identified in an unborn child cannot be repaired. To prevent the manifestation of the undesirable trait the unborn child is destroyed. The arguments in support of human enhancement are based on an ethic of consequence that could allow for nearly any means as long as the desired end is reached. Medical enhancement may affect the parent–child family unit; the parents’ love for the child may be conditioned on the expected results. The new eugenics, although based on science, continues to pursue the same goal as the old eugenics, the development of a superior individual and the elimination of those considered inferior. PMID:25249705

  14. Piezoelectric enhancement under negative pressure

    NASA Astrophysics Data System (ADS)

    Kvasov, Alexander; McGilly, Leo J.; Wang, Jin; Shi, Zhiyong; Sandu, Cosmin S.; Sluka, Tomas; Tagantsev, Alexander K.; Setter, Nava

    2016-07-01

    Enhancement of ferroelectric properties, both spontaneous polarization and Curie temperature under negative pressure had been predicted in the past from first principles and recently confirmed experimentally. In contrast, piezoelectric properties are expected to increase by positive pressure, through polarization rotation. Here we investigate the piezoelectric response of the classical PbTiO3, Pb(Zr,Ti)O3 and BaTiO3 perovskite ferroelectrics under negative pressure from first principles and find significant enhancement. Piezoelectric response is then tested experimentally on free-standing PbTiO3 and Pb(Zr,Ti)O3 nanowires under self-sustained negative pressure, confirming the theoretical prediction. Numerical simulations verify that negative pressure in nanowires is the origin of the enhanced electromechanical properties. The results may be useful in the development of highly performing piezoelectrics, including lead-free ones.

  15. Piezoelectric enhancement under negative pressure.

    PubMed

    Kvasov, Alexander; McGilly, Leo J; Wang, Jin; Shi, Zhiyong; Sandu, Cosmin S; Sluka, Tomas; Tagantsev, Alexander K; Setter, Nava

    2016-01-01

    Enhancement of ferroelectric properties, both spontaneous polarization and Curie temperature under negative pressure had been predicted in the past from first principles and recently confirmed experimentally. In contrast, piezoelectric properties are expected to increase by positive pressure, through polarization rotation. Here we investigate the piezoelectric response of the classical PbTiO3, Pb(Zr,Ti)O3 and BaTiO3 perovskite ferroelectrics under negative pressure from first principles and find significant enhancement. Piezoelectric response is then tested experimentally on free-standing PbTiO3 and Pb(Zr,Ti)O3 nanowires under self-sustained negative pressure, confirming the theoretical prediction. Numerical simulations verify that negative pressure in nanowires is the origin of the enhanced electromechanical properties. The results may be useful in the development of highly performing piezoelectrics, including lead-free ones. PMID:27396411

  16. Plasmon enhancement of luminescence upconversion.

    PubMed

    Park, Wounjhang; Lu, Dawei; Ahn, Sungmo

    2015-05-21

    Frequency conversion has always been an important topic in optics. Nonlinear optics has traditionally focused on frequency conversion based on nonlinear susceptibility but with the recent development of upconversion nanomaterials, luminescence upconversion has begun to receive renewed attention. While upconversion nanomaterials open doors to a wide range of new opportunities, they remain too inefficient for most applications. Incorporating plasmonic nanostructures provides a promising pathway to highly efficient upconversion. Naturally, a plethora of theoretical and experimental studies have been published in recent years, reporting enhancements up to several hundred. It is however difficult to make meaningful comparisons since the plasmonic fields are highly sensitive to the local geometry and excitation condition. Also, many luminescence upconversion processes involve multiple steps via different physical mechanisms and the overall output is often determined by a delicate interplay among them. This review is aimed at offering a comprehensive framework for plasmon enhanced luminescence upconversion. We first present quantum electrodynamics descriptions for all the processes involved in luminescence upconversion, which include absorption, emission, energy transfer and nonradiative transitions. We then present a bird's eye view of published works on plasmon enhanced upconversion, followed by more detailed discussion on comparable classes of nanostructures, the effects of spacer layers and local heating, and the dynamics of the plasmon enhanced upconversion process. Plasmon enhanced upconversion is a challenging and exciting field from the fundamental scientific perspective and also from technological standpoints. It offers an excellent system to study how optical processes are affected by the local photonic environment. This type of research is particularly timely as the plasmonics is placing heavier emphasis on nonlinearity. At the same time, efficient upconversion

  17. Superresolution via enhanced evanescent tunneling.

    PubMed

    Salandrino, Alessandro; Christodoulides, Demetrios N

    2011-02-15

    We here propose the concept of enhanced evanescent tunneling (EET). Our analysis indicates that by means of a suitable control field, the transmission of evanescent waves across a forbidden gap can be enhanced by several orders of magnitude-well beyond the ordinary frustrated total internal reflection case. We show how such a phenomenon can be used to probe both the amplitude and phase of the evanescent portion of the angular spectrum, thereby allowing target superresolution. In principle EET can be manifested in other areas of physics where wave tunneling is involved. PMID:21326431

  18. Biological enhancement of hydrocarbon extraction

    DOEpatents

    Brigmon, Robin L.; Berry, Christopher J.

    2009-01-06

    A method of microbial enhanced oil recovery for recovering oil from an oil-bearing rock formation is provided. The methodology uses a consortium of bacteria including a mixture of surfactant producing bacteria and non-surfactant enzyme producing bacteria which may release hydrocarbons from bitumen containing sands. The described bioprocess can work with existing petroleum recovery protocols. The consortium microorganisms are also useful for treatment of above oil sands, ground waste tailings, subsurface oil recovery, and similar materials to enhance remediation and/or recovery of additional hydrocarbons from the materials.

  19. Enhanced image capture through fusion

    NASA Technical Reports Server (NTRS)

    Burt, Peter J.; Hanna, Keith; Kolczynski, Raymond J.

    1993-01-01

    Image fusion may be used to combine images from different sensors, such as IR and visible cameras, to obtain a single composite with extended information content. Fusion may also be used to combine multiple images from a given sensor to form a composite image in which information of interest is enhanced. We present a general method for performing image fusion and show that this method is effective for diverse fusion applications. We suggest that fusion may provide a powerful tool for enhanced image capture with broad utility in image processing and computer vision.

  20. Enhanced coagulation for arsenic removal

    SciTech Connect

    Cheng, R.C.; Liang, S.; Wang, H.C.; Beuhler, M.D. )

    1994-09-01

    The possible use of enhanced coagulation for arsenic removal was examined at the facilities of a California utility in 1992 and 1993. The tests were conducted at bench, pilot, and demonstration scales, with two source waters. Alum and ferric chloride, with cationic polymer, were investigated at various influence arsenic concentrations. The investigators concluded that for the source waters tested, enhanced coagulation could be effective for arsenic removal and that less ferric chloride than alum, on a weight basis, is needed to achieve the same removal.

  1. Power enhanced frequency conversion system

    NASA Technical Reports Server (NTRS)

    Sanders, Steven (Inventor); Lang, Robert J. (Inventor); Waarts, Robert G. (Inventor)

    2001-01-01

    A frequency conversion system includes at least one source providing a first near-IR wavelength output including a gain medium for providing high power amplification, such as double clad fiber amplifier, a double clad fiber laser or a semiconductor tapered amplifier to enhance the power output level of the near-IR wavelength output. The NFM device may be a difference frequency mixing (DFM) device or an optical parametric oscillation (OPO) device. Pump powers are gain enhanced by the addition of a rare earth amplifier or oscillator, or a Ra-man/Brillouin amplifier or oscillator between the high power source and the NFM device.

  2. Temporal resolution enhancement from motion

    NASA Astrophysics Data System (ADS)

    Rollason, M. P.; Watson, G. H.; Strens, M. J. A.

    2009-09-01

    We describe progress in the third year of the EMRS DTC TEP theme project entitled "Temporal Resolution Enhancement from Motion". The aim is to develop algorithms that combine evidence over time from a sequence of images in order to improve spatial resolution and reduce unwanted artefacts. Years one and two of this project developed and demonstrated an efficient algorithm that provided good resolution enhancement of a scene viewed in the far field (approximately flat) [1]. This paper reports a new algorithm which is applicable to a three dimensional scene where substantial depth variation causes parallax within the imagery. The new algorithm is demonstrated using airborne infra-red imagery.

  3. Lift enhancement in flying snakes

    NASA Astrophysics Data System (ADS)

    Krishnan, Anush; Socha, John; Vlachos, Pavlos; Barba, Lorena

    2013-11-01

    Flying snakes use a unique method of aerial locomotion: they jump from tree branches, flatten their bodies and undulate through the air to produce a glide. The shape of their body cross-section during the glide plays an important role in generating lift. We present a computational investigation of the aerodynamics of the cross-sectional shape. We performed two-dimensional simulations of incompressible flow past the anatomically correct cross-section of the species Chrysopelea paradisi, which show that a significant enhancement in lift appears at an angle of attack of 35 degrees, for Reynolds numbers 2000 and above. Previous experiments on physical models also demonstrated an increased lift and at the same angle of attack. The simulations point to the lift enhancement arising from the early separation of the boundary layer on the dorsal surface of the snake profile, without stall. The separated shear layer rolls up and interacts with secondary vorticity in the near-wake, inducing the primary vortex to remain closer to the body and thus cause enhanced suction, resulting in higher lift. In physical experiments, the flow is inherently 3-D due to fluid instabilities, and it is intriguing that the enhanced lift also appears in the two-dimensional simulations.

  4. Enhancing What Students Can Do

    ERIC Educational Resources Information Center

    Poel, Elissa Wolfe

    2007-01-01

    The Human Function Model, as described in the University of Kentucky Assistive Technology Project, places assistive technology in its proper perspective, as an external support that can enhance an individual's ability to function within the environment. The National Assistive Technology Research Institute groups assistive technology and related…

  5. Creating a Visually Enhanced Performance.

    ERIC Educational Resources Information Center

    Allison, Joseph H.

    1998-01-01

    Maintains that visually enhanced musical performances provide an exciting and creative aspect of musical production. Explains that the conductor should choose a musical selection that offers concrete visual opportunities, focus on visual images, choose video excerpts, and use dance if possible. Finds that many visual techniques used by marching…

  6. Biosurfactant and enhanced oil recovery

    DOEpatents

    McInerney, Michael J.; Jenneman, Gary E.; Knapp, Roy M.; Menzie, Donald E.

    1985-06-11

    A pure culture of Bacillus licheniformis strain JF-2 (ATCC No. 39307) and a process for using said culture and the surfactant lichenysin produced thereby for the enhancement of oil recovery from subterranean formations. Lichenysin is an effective surfactant over a wide range of temperatures, pH's, salt and calcium concentrations.

  7. Alumina-Enhanced Thermal Barrier

    NASA Technical Reports Server (NTRS)

    Smith, Marnell; Leiser, Dan; Goldstein, Howard

    1989-01-01

    Rigid, fibrous ceramic tile material called "alumina-enhanced thermal barrier" (AETB) extends temperature capability of insulating materials. Material has obvious potential for terrestrial use in kilns, furnaces, heat engines, and other applications in which light weight and high operating temperature are specified. Three kinds of ceramic fibers are blended, molded, and sintered to make refractory tiles.

  8. Enhancing Literacy Skills through Technology.

    ERIC Educational Resources Information Center

    Sistek-Chandler, Cynthia

    2003-01-01

    Discusses how to use technology to enhance literacy skills. Highlights include defining literacy, including information literacy; research to support reading and writing instruction; literacy software; thinking skills; organizational strategies for writing and reading; how technology can individualize literacy instruction; and a new genre of…

  9. Germplasm enhancement for RWA resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our contribution to this annual report is a summary of research accomplishments for 2008 in germplasm enhancement for RWA resistance in barley at the USDA-ARS Wheat, Peanuts and other Field Crops Research Unit, Stillwater, OK. RWA is a serious pest of barley in the intermountain regions of the west...

  10. Key Issue: Enhancing Teacher Leadership

    ERIC Educational Resources Information Center

    National Comprehensive Center for Teacher Quality, 2007

    2007-01-01

    "Teachers are leaders when they function in professional communities to affect student learning; contribute to school improvement; inspire excellence in practice; and empower stakeholders to participate in educational improvement" (Childs-Bowen, Moller, & Scrivner, 2000, p. 28). Enhancing teacher leadership can help schools and districts reach the…

  11. GERMPLASM ENHANCEMENT FOR RWA RESISTANCE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our contribution to this annual newsletter is a summary of research accomplishments in the past year in germplasm enhancement for RWA resistance in barley at the USDA-ARS Plant Science and Water Conservation Research Laboratory, Stillwater, OK. RWA is a serious pest of barley in the intermountain r...

  12. Enhancing Preservice Mathematics Teachers' TPCK

    ERIC Educational Resources Information Center

    Hardy, Michael

    2010-01-01

    The goal of the X-Tech project was to enhance preservice teachers' perceptions of their preparedness to teach with technology. Results indicated that practically-oriented methods that meet a variety of technology related needs are viable for attaining such a goal. Further, it is particularly beneficial to have teachers use a variety of resources…

  13. Ohio's Career Enhancement Pilot Projects.

    ERIC Educational Resources Information Center

    Ohio State Legislative Office of Education Oversight, Columbus.

    This report on an evaluation of Ohio state-funded career enhancement pilot programs cover six school districts. Four kinds of programs are covered: (1) career ladder--teachers are promoted through a series of steps based on different levels of competence and responsibility; (2) career option--teachers take on and are compensated for defined…

  14. Lift enhancing tabs for airfoils

    NASA Technical Reports Server (NTRS)

    Ross, James C. (Inventor)

    1994-01-01

    A tab deployable from the trailing edge of a main airfoil element forces flow onto a following airfoil element, such as a flap, to keep the flow attached and thus enhance lift. For aircraft wings with high lift systems that include leading edge slats, the slats may also be provided with tabs to turn the flow onto the following main element.

  15. Forensics: Enhancing Civic Literacy & Democracy

    ERIC Educational Resources Information Center

    Briscoe, Shawn F.

    2009-01-01

    Forensics--interpretation, speech, and debate--can and should be a meaningful part of every school's curriculum. To put it simply, the course of study, alongside cocurricular competition, promotes civic education and enhances the standard curriculum by helping students explore myriad topics from multiple angles and find the truth in each,…

  16. Germplasm enhancement for RWA resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our contribution to this annual report is a summary of research accomplishments for 2010 in germplasm enhancement for RWA resistance in barley at the USDA-ARS, Wheat, Peanuts and other Field Crops Research Unit, Stillwater, OK. RWA is a serious pest of barley in the intermountain regions of the wes...

  17. Enhancing Instruction through Software Infusion.

    ERIC Educational Resources Information Center

    Sia, Archie P.

    The presence of the computer in the classroom is no longer considered an oddity; it has become an ordinary resource for teachers to use for the enhancement of instruction. This paper presents an examination of software infusion, i.e., the use of computer software to enrich instruction in an academic curriculum. The process occurs when a chosen…

  18. Germplasm enhancement for RWA resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our contribution to this annual newsletter is a summary of research accomplishments in the past year in germplasm enhancement for RWA resistance in barley at the USDA-ARS Wheat, Peanut and Other Field Crops Research Unit, Stillwater, OK. RWA is a serious pest of barley in the intermountain regions ...

  19. Enhancing Author's Voice through Scripting

    ERIC Educational Resources Information Center

    Young, Chase J.; Rasinski, Timothy V.

    2011-01-01

    The authors suggest using scripting as a strategy to mentor and enhance author's voice in writing. Through gradual release, students use authentic literature as a model for writing with voice. The authors also propose possible extensions for independent practice, integration across content areas, and tips for evaluation.

  20. Motivation Enhancement Through Work Redesign.

    ERIC Educational Resources Information Center

    Oldham, Greg R., Kulik, Carol T.

    1983-01-01

    The possibility of redesigning the work experiences of faculty members in an effort to enhance their motivation, productivity, and personal and work satisfactions is examined. One approach to work redesign, job characteristics theory, is described. Several strategies are discussed. (Author/MLW)

  1. Germplasm enhancement for RWA resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our contribution to this annual newsletter is a summary of research accomplishments in the past year in germplasm enhancement for RWA resistance in barley at the USDA-ARS, Wheat, Peanut and Other Field Crops Research Unit, Stillwater, OK. RWA is a serious pest of barley in the intermountain regions...

  2. Germplasm enhancement for RWA resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our contribution to this annual newsletter is a summary of research accomplishments in the past year in germplasm enhancement for RWA resistance in barley at the USDA-ARS Wheat, Peanut and Other Field Crops Research Unit, Stillwater, OK. Russian wheat aphid (RWA) is a serious pest of barley in the ...

  3. Enhancing hydrogen spillover and storage

    DOEpatents

    Yang, Ralph T; Li, Yingwei; Lachawiec, Jr., Anthony J

    2013-02-12

    Methods for enhancing hydrogen spillover and storage are disclosed. One embodiment of the method includes doping a hydrogen receptor with metal particles, and exposing the hydrogen receptor to ultrasonication as doping occurs. Another embodiment of the method includes doping a hydrogen receptor with metal particles, and exposing the doped hydrogen receptor to a plasma treatment.

  4. Enhancing hydrogen spillover and storage

    DOEpatents

    Yang, Ralph T.; Li, Yingwel; Lachawiec, Jr., Anthony J.

    2011-05-31

    Methods for enhancing hydrogen spillover and storage are disclosed. One embodiment of the method includes doping a hydrogen receptor with metal particles, and exposing the hydrogen receptor to ultrasonification as doping occurs. Another embodiment of the method includes doping a hydrogen receptor with metal particles, and exposing the doped hydrogen receptor to a plasma treatment.

  5. Innovative Solution to Video Enhancement

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Through a licensing agreement, Intergraph Government Solutions adapted a technology originally developed at NASA's Marshall Space Flight Center for enhanced video imaging by developing its Video Analyst(TM) System. Marshall's scientists developed the Video Image Stabilization and Registration (VISAR) technology to help FBI agents analyze video footage of the deadly 1996 Olympic Summer Games bombing in Atlanta, Georgia. VISAR technology enhanced nighttime videotapes made with hand-held camcorders, revealing important details about the explosion. Intergraph's Video Analyst System is a simple, effective, and affordable tool for video enhancement and analysis. The benefits associated with the Video Analyst System include support of full-resolution digital video, frame-by-frame analysis, and the ability to store analog video in digital format. Up to 12 hours of digital video can be stored and maintained for reliable footage analysis. The system also includes state-of-the-art features such as stabilization, image enhancement, and convolution to help improve the visibility of subjects in the video without altering underlying footage. Adaptable to many uses, Intergraph#s Video Analyst System meets the stringent demands of the law enforcement industry in the areas of surveillance, crime scene footage, sting operations, and dash-mounted video cameras.

  6. Surface-Enhanced Raman Spectroscopy.

    ERIC Educational Resources Information Center

    Garrell, Robin L.

    1989-01-01

    Reviews the basis for the technique and its experimental requirements. Describes a few examples of the analytical problems to which surface-enhanced Raman spectroscopy (SERS) has been and can be applied. Provides a perspective on the current limitations and frontiers in developing SERS as an analytical technique. (MVL)

  7. Who Benefits from Pension Enhancements?

    ERIC Educational Resources Information Center

    Koedel, Cory; Ni, Shawn; Podgursky, Michael

    2014-01-01

    During the late 1990s public pension funds across the United States accrued large actuarial surpluses. The seemingly flush conditions of the pension funds led legislators in most states to substantially improve retirement benefits for public workers, including teachers. In this study we examine the benefit enhancements to the teacher pension…

  8. Enhancing the Productivity of Learning.

    ERIC Educational Resources Information Center

    Johnstone, D. Bruce

    1995-01-01

    It is argued that colleges and universities can become more productive by enhancing the efficiency of student learning. This requires both acceleration of learning through individually paced mastery learning, better academic focus, year-round schooling, and an earlier start to graduate and professional education. Eight strategies for enhancing…

  9. CPS Science Laboratory Enhancement Project

    SciTech Connect

    James, Chandra

    2014-12-03

    The lab enhancement initiative was designed to support early implementation efforts of new policy to promote safe learning environments and school labs called the Chemical Safety and Hygiene Plan (CSHP). These efforts included comprehensive inventories and chemical removals at all Chicago Public High Schools, conducted by environmental health and safety consultants, and the development of professional development resources for teachers.

  10. 10 Suggestions for Enhancing Lecturing

    ERIC Educational Resources Information Center

    Heitzmann, Ray

    2010-01-01

    Criticism of the lecture method remains a staple of discussion and writing in academia--and most of the time it's deserved! Those interested in improving this aspect of their teaching might wish to consider some or all of the following suggestions for enhancing lectures. These include: (1) Lectures must start with a "grabber"; (2) Lectures must be…

  11. Communication Enhancement: Principles and Practices.

    ERIC Educational Resources Information Center

    Shane, Howard

    1988-01-01

    A physician discusses the work of the Communications Enhancement Clinic at Children's Hospital-Boston in providing assistance to children with severe speech problems. He describes the process of evaluating and matching a child's strengths and weaknesses to available technology, including educational software, speech or print output devices, and…

  12. Germplasm enhancement for RWA resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our contribution to this annual report is a summary of research accomplishments for 2007 in germplasm enhancement for RWA resistance in barley at the USDA-ARS Wheat, Peanuts and other Field Crops Research Unit, Stillwater, OK. RWA is a serious pest of barley in the intermountain regions of the west...

  13. Effectiveness of Enhanced Safety Management

    SciTech Connect

    Waterfall, K.W. )

    1988-01-01

    This paper discusses the development of an Enhanced Safety Management (ESM) campaign to improve safety and reduce risk in oil and gas exploration. The essentials of ESM are summarized by the author. The paper addresses the method developed to implement ESM and how the control of process designs to control operations minimizes the risk of a major accident.

  14. Effect of High Sugar Intake on Glucose Transporter and Weight Regulating Hormones in Mice and Humans

    PubMed Central

    Ritze, Yvonne; Bárdos, Gyöngyi; D’Haese, Jan G.; Ernst, Barbara; Thurnheer, Martin; Schultes, Bernd; Bischoff, Stephan C.

    2014-01-01

    Objective Sugar consumption has increased dramatically over the last decades in Western societies. Especially the intake of sugar-sweetened beverages seems to be a major risk for the development of obesity. Thus, we compared liquid versus solid high-sugar diets with regard to dietary intake, intestinal uptake and metabolic parameters in mice and partly in humans. Methods Five iso-caloric diets, enriched with liquid (in water 30% vol/vol) or solid (in diet 65% g/g) fructose or sucrose or a control diet were fed for eight weeks to C57bl/6 mice. Sugar, liquid and caloric intake, small intestinal sugar transporters (GLUT2/5) and weight regulating hormone mRNA expression, as well as hepatic fat accumulation were measured. In obese versus lean humans that underwent either bariatric surgery or small bowel resection, we analyzed small intestinal GLUT2, GLUT5, and cholecystokinin expression. Results In mice, the liquid high-sucrose diet caused an enhancement of total caloric intake compared to the solid high-sucrose diet and the control diet. In addition, the liquid high-sucrose diet increased expression of GLUT2, GLUT5, and cholecystokinin expression in the ileum (P<0.001). Enhanced liver triglyceride accumulation was observed in mice being fed the liquid high-sucrose or -fructose, and the solid high-sucrose diet compared to controls. In obese, GLUT2 and GLUT5 mRNA expression was enhanced in comparison to lean individuals. Conclusions We show that the form of sugar intake (liquid versus solid) is presumably more important than the type of sugar, with regard to feeding behavior, intestinal sugar uptake and liver fat accumulation in mice. Interestingly, in obese individuals, an intestinal sugar transporter modulation also occurred when compared to lean individuals. PMID:25010715

  15. Blob-enhanced reconstruction technique

    NASA Astrophysics Data System (ADS)

    Castrillo, Giusy; Cafiero, Gioacchino; Discetti, Stefano; Astarita, Tommaso

    2016-09-01

    A method to enhance the quality of the tomographic reconstruction and, consequently, the 3D velocity measurement accuracy, is presented. The technique is based on integrating information on the objects to be reconstructed within the algebraic reconstruction process. A first guess intensity distribution is produced with a standard algebraic method, then the distribution is rebuilt as a sum of Gaussian blobs, based on location, intensity and size of agglomerates of light intensity surrounding local maxima. The blobs substitution regularizes the particle shape allowing a reduction of the particles discretization errors and of their elongation in the depth direction. The performances of the blob-enhanced reconstruction technique (BERT) are assessed with a 3D synthetic experiment. The results have been compared with those obtained by applying the standard camera simultaneous multiplicative reconstruction technique (CSMART) to the same volume. Several blob-enhanced reconstruction processes, both substituting the blobs at the end of the CSMART algorithm and during the iterations (i.e. using the blob-enhanced reconstruction as predictor for the following iterations), have been tested. The results confirm the enhancement in the velocity measurements accuracy, demonstrating a reduction of the bias error due to the ghost particles. The improvement is more remarkable at the largest tested seeding densities. Additionally, using the blobs distributions as a predictor enables further improvement of the convergence of the reconstruction algorithm, with the improvement being more considerable when substituting the blobs more than once during the process. The BERT process is also applied to multi resolution (MR) CSMART reconstructions, permitting simultaneously to achieve remarkable improvements in the flow field measurements and to benefit from the reduction in computational time due to the MR approach. Finally, BERT is also tested on experimental data, obtaining an increase of the

  16. Enhancing who? Enhancing what? Ethics, bioethics, and transhumanism.

    PubMed

    Koch, Tom

    2010-12-01

    Transhumanists advance a "posthuman" condition in which technological and genetic enhancements will transform humankind. They are joined in this goal by bioethicists arguing for genetic selection as a means of "enhancing evolution," improving if not also the species then at least the potential lives of future individuals. The argument of both, this paper argues, is a new riff on the old eugenics tune. As ever, it is done in the name of science and its presumed knowledge base. As ever, the result is destructive rather than instructive, bad faith promoted as high ideal. The paper concludes with the argument that species advancement is possible but in a manner thoroughly distinct from that advanced by either of these groups. PMID:21041805

  17. Gene expression of epithelial glucose transporters: the role of diabetes mellitus.

    PubMed

    Dominguez, J H; Song, B; Maianu, L; Garvey, W T; Qulali, M

    1994-11-01

    The functions of absorption of dietary glucose by the small intestine and reabsorption of filtered glucose by the renal proximal tubule are strikingly similar in their organization and in the way they adapt to uncontrolled diabetes mellitus. In both cases, transepithelial glucose and Na+ fluxes are augmented. The epithelial adaptations to hyperglycemia of uncontrolled diabetes are accomplished by increasing the glucose transport surface area and the number of the efflux glucose transporter GLUT2 located in the basolateral membrane. The signals that modify the size of the epithelium and the overexpression of basolateral GLUT2 are not known. It was speculated that high glucose levels and enhanced Na+ flux may be important factors in the signaling event that culminates in a renal and intestinal epithelium that is modified to transport higher rates of glucose against a higher extracellular level of glucose. PMID:7873742

  18. Effects of Chemical Enhancers on Human Epidermal Membrane: Structure-Enhancement Relationship based on Maximum Enhancement (Emax)

    PubMed Central

    IBRAHIM, SARAH A.; LI, S. KEVIN

    2008-01-01

    Chemical penetration enhancers are widely used in transdermal pharmaceuticals as well as cosmetic products. Selection of suitable enhancers in topical formulations requires an understanding of the mechanism of action of these enhancers. The objective of the present study was to evaluate the enhancement effects of a number of commonly known enhancers and cosmetic ingredients on permeation across human epidermal membrane (HEM). The potencies of these chemical enhancers—maximum enhancement, Emax—were compared at their highest thermodynamic activity in equilibrium with HEM (i.e., solubility equilibrium). This was achieved by the treatment of HEM with the enhancer or phosphate buffered saline (PBS) saturated with the enhancer. Passive transport experiments were then conducted with a model permeant corticosterone to determine the effects of these enhancers on the lipoidal pathway of HEM. The results suggest that Emax of an enhancer is related to its octanol/water partition coefficient and its solubility in the HEM lipid domain. A relationship between enhancer Emax and its solubility in silicone elastomer was also observed, suggesting the use of silicone solubility to predict enhancer potency. Based on the Emax results, some common topical ingredients were found to be more potent enhancers than a number of well-known chemical enhancers. PMID:18623209

  19. Deep Ultrasound Enhancements Final Report

    SciTech Connect

    Quarry, M; Thomas, G; Ward, W; Gardner, D

    2006-05-01

    This study involves collaboration between Los Alamos National Laboratory and Lawrence Livermore National Laboratory to enhance and optimize LANL's ultrasonic inspection capabilities for production. Deep-penetrating ultrasonic testing enhancement studies will extend the current capabilities, which only look for disbonds. Current ultrasonic methods in production use 15-20 MHz to inspect for disbonds. The enhanced capabilities use 5 MHz to penetrate to the back surface and image the back surface for any flaws. The enhanced capabilities for back surface inspection use transducers and squirter modifications that can be incorporated into the existing production system. In a production setup the current 15-20 MHz transducer and squirter would perform a bond inspection, followed by a deep inspection that would be performed by simply swapping out the 5 MHz transducer and squirter. Surrogate samples were manufactured of beryllium and bismuth to perform the ultrasonic enhancement studies. The samples were used to simulate flaws on the back surface and study ultrasound's ability to image them. The ultrasonic technique was optimized by performing experiments with these samples and analyzing transducer performance in detecting flaws in the surrogate. Beam patterns were also studied experimentally using a steel ball reflector to measure beam patterns, focal points, and sensitivities to better understand the relationship between design and performance. Many transducers were evaluated including transducers from LANL's production system, LLNL, and other commercially available transducers. Squirter design was also analyzed while performing experiments Flat-bottom holes and ball-mill defects of various sizes were introduced into the samples for experimentation. Flaws depths were varied from .020'' to 0.060'', and diameters varied from 0.0625'' to 0.187''. The smallest defect, .020'' depth and 0.0625'', was detected. Ultrasonic amplitude features produced better images than time

  20. Biosurfactant-enhanced soil bioremediation

    SciTech Connect

    Kosaric, N.; Lu, G.; Velikonja, J.

    1995-12-01

    Bioremediation of soil contaminated with organic chemicals is a viable alternative method for clean-up and remedy of hazardous waste sites. The final objective in this approach is to convert the parent toxicant into a readily biodegradable product which is harmless to human health and/or the environment. Biodegradation of hydrocarbons in soil can also efficiently be enhanced by addition or in-situ production of biosufactants. It was generally observed that the degradation time was shortened and particularly the adaptation time for the microbes. More data from our laboratories showed that chlorinated aromatic compounds, such as 2,4-dichlorophenol, a herbicide Metolachlor, as well as naphthalene are degraded faster and more completely when selected biosurfactants are added to the soil. More recent data demonstrated an enhanced biodegradation of heavy hydrocarbons in petrochemical sludges, and in contaminated oil when biosurfactants were present or were added prior to the biodegradation process.

  1. Permeability enhancement using explosive techniques

    SciTech Connect

    Adams, T.F.; Schmidt, S.C.; Carter, W.J.

    1980-01-01

    In situ recovery methods for many of our hydrocarbon and mineral resources depend on the ability to create or enhance permeability in the resource bed to allow uniform and predictable flow. To meet this need, a new branch of geomechanics devoted to computer prediction of explosive rock breakage and permeability enhancement has developed. The computer is used to solve the nonlinear equations of compressible flow, with the explosive behavior and constitutive properties of the medium providing the initial/boundary conditions and material response. Once the resulting computational tool has been verified and calibrated with appropriate large-scale field tests, it can be used to develop and optimize commercially useful explosive techniques for in situ resource recovery.

  2. Contrast-enhanced refraction imaging

    NASA Astrophysics Data System (ADS)

    Hall, Christopher J.; Rogers, Keith D.; Lewis, Rob A.; Menk, Ralf Hendrik; Arfelli, Fulvia; Siu, Karen K.; Benci, A.; Kitchen, M.; Pillon, Alessandra; Rigon, Luigi; Round, Andrew J.; Hufton, Alan P.; Evans, Andrew; Pinder, Sarah E.; Evans, S.

    2004-01-01

    An attempt has been made, for the first time, to extend the capabilities of diffraction enhanced imaging (DEI) using low concentrations of a contrast agent. A phantom has been constructed to accommodate a systematic series of diluted bromine deoxyuridase (BrDU) samples in liquid form. This was imaged using a conventional DEI arrangement and at a range of energies traversing the Br K-edge. The images were analyzed to provide a quantitative measure of contrast as a function of X-ray energy and (BrDU) concentration. The results indicate that the particular experimental arrangement was not optimized to exploit the potential of this contrast enhancement and several suggestions are discussed to improve this further.

  3. Three Fresh Exposures, Enhanced Color

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This enhanced-color panoramic camera image from the Mars Exploration Rover Opportunity features three holes created by the rock abrasion tool between sols 143 and 148 (June 18 and June 23, 2004) inside 'Endurance Crater.' The enhanced image makes the red colors a little redder and blue colors a little bluer, allowing viewers to see differences too subtle to be seen without the exaggeration. When compared with an approximately true color image, the tailings from the rock abrasion tool and the interior of the abraded holes are more prominent in this view. Being able to discriminate color variations helps scientists determine rocks' compositional differences and texture variations. This image was created using the 753-, 535- and 432-nanometer filters.

  4. Enhanced Histopathology of the Spleen

    PubMed Central

    Elmore, Susan A.

    2007-01-01

    The spleen is the largest secondary lymphoid organ, is considered the draining site for compounds that are administered intravenously, and is therefore considered an important organ to evaluate for treatment-related lesions. Due to the presence of B and T lymphocytes, the immunotoxic effects of xenobiotics or their metabolites on these cell populations may be reflected in the spleen. Therefore it is one of the recommended organs to evaluate for enhanced histopathology of the immune system. The two major functional zones of the spleen are the hematogenous red pulp and the lymphoid white pulp (periarteriolar sheaths, follicles and marginal zones). For enhanced histopathology, these splenic compartments should be evaluated separately for changes in size and cellularity, and descriptive rather than interpretive terminology should be used to characterize any changes (Haley et al., 2005). Moreover, germinal center development within the lymphoid follicles should be noted as increased or decreased. PMID:17067950

  5. Mixing enhancement using axial flow

    NASA Technical Reports Server (NTRS)

    Papamoschou, Dimitri (Inventor)

    2003-01-01

    A method and an apparatus for enhancing fluid mixing. The method comprises the following: (a) configuring a duct to have an effective outer wall, an effective inner wall, a cross-sectional shape, a first cross-sectional area and an exit area, the first cross-sectional area and the exit area being different in size; (b) generating a first flow at the first cross-sectional area, the first flow having a total pressure and a speed equal to or greater than a local speed of sound; and (c) generating a positive streamwise pressure gradient in a second flow in proximity of the exit area. The second flow results from the first flow. Fluid mixing is enhanced downstream from the duct exit area.

  6. Resolution enhanced sound detecting apparatus

    NASA Technical Reports Server (NTRS)

    Kendall, J. M. (Inventor)

    1979-01-01

    An apparatus is described for enhancing the resolution of a sound detector of the type which includes an acoustic mirror for focusing sound from an object onto a microphone to enable the determination of the location from which the sound arises. The enhancement apparatus includes an enclosure which surrounds the space between the mirror and microphone, and contains a gas heavier than air, such as Freon, through which sound moves slower and therefore with a shorter wavelength than in air, so that a mirror of given size has greater resolving power. An acoustically transparent front wall of the enclosure which lies forward of the mirror, can include a pair of thin sheets with pressured air between them, to form an end of the region of heavy gas into a concave shape.

  7. Hadronic resonances enhanced by thresholds

    NASA Astrophysics Data System (ADS)

    Caramés, T. F.; Valcarce, A.

    2016-07-01

    We present a neat example of a meson-baryon system where the vicinity of two different thresholds enhances the binding of a hadronic resonance, a pentaquark. As a consequence the pattern of states may change when moving among different flavor sectors, what poses a warning on naive extrapolations to heavy flavor sectors based on systematic expansions. For this purpose we simultaneously analyze the N D bar and NB two-hadron systems looking for possible bound states or resonances. When a resonance is controlled by a coupled-channel effect, going to a different flavor sector may enhance or diminish the binding. This effect may, for example, generate significant differences between the charmonium and bottomonium spectra above open-flavor thresholds or pentaquark states in the open-charm and open-bottom sectors.

  8. Fertility-enhancing hysteroscopic surgery.

    PubMed

    Cela, Vito; Litta, Pietro; Franchini, Mario; Sergiampietri, Claudia; Simi, Giovanna; Freschi, Letizia; Artini, Paolo G; Papini, Francesca

    2016-04-01

    Anatomical uterine element and functional components play a fundamental role in the enhancing of fertility are the major actors. Uterine pathologies, including congenital or acquired lesions, have been reported in 21 to 47% of patients undergoing in vitro fertilization cycles. Hysteroscopy is an important procedure in the study of one of the most important element of fertility: the uterus, even if its use in the world of infertility is discussed. There are many studies on safety and feasibility of the procedure and on patient compliance, but there is no consensus on its systemic use. This study, thanks to the wide literature about the use of hysteroscopic surgery to enhance fertility in most of the congenital and acquired problems affecting women in fertility age, allows defining that diagnostic and operative hysteroscopy is a rapid and safety technology to improve fertility. PMID:26928416

  9. Microbial enhanced oil recovery (MEOR).

    PubMed

    Brown, Lewis R

    2010-06-01

    Two-thirds of the oil ever found is still in the ground even after primary and secondary production. Microbial enhanced oil recovery (MEOR) is one of the tertiary methods purported to increase oil recovery. Since 1946 more than 400 patents on MEOR have been issued, but none has gained acceptance by the oil industry. Most of the literature on MEOR is from laboratory experiments or from field trials of insufficient duration or that lack convincing proof of the process. Several authors have made recommendations required to establish MEOR as a viable method to enhance oil recovery, and until these tests are performed, MEOR will remain an unproven concept rather than a highly desirable reality. PMID:20149719

  10. Enhancing Research Papers in Astronomy

    NASA Astrophysics Data System (ADS)

    Kroffe, Kerry; McCann, G.

    2013-01-01

    XML-based production of journal articles, combined with real-time transformations, now make it possible to develop new enhancements to the reading experience and to the content of the article itself. Papers from AAS journals are now available in ‘Article Evolution’ HTML format, providing both familiar and new functionality that improves the reading experience. This poster will outline the roadmap for the development of ‘Article Evolution’ functionality and ask for input to help shape future enhancements that meet the needs of the astronomy community. Two of the ongoing developments described are ’semantic enrichment’ of articles and adoption of ORCID (Open Researcher and Contributor ID). Both of these have exciting possibilities at an article level within ‘Article Evolution’ but will also impact widely on third party services, such as linking and discovery of research papers.

  11. Method for enhanced oil recovery

    DOEpatents

    Comberiati, Joseph R.; Locke, Charles D.; Kamath, Krishna I.

    1980-01-01

    The present invention is directed to an improved method for enhanced recovery of oil from relatively "cold" reservoirs by carbon dioxide flooding. In oil reservoirs at a temperature less than the critical temperature of 87.7.degree. F. and at a pore pressure greater than the saturation pressure of carbon dioxide at the temperature of the reservoir, the carbon dioxide remains in the liquid state which does not satisfactorily mix with the oil. However, applicants have found that carbon dioxide can be vaporized in situ in the reservoir by selectively reducing the pore pressure in the reservoir to a value less than the particular saturated vapor pressure so as to greatly enhance the mixing of the carbon dioxide with the oil.

  12. Nonhereditary enhancement of progeny growth

    NASA Technical Reports Server (NTRS)

    Khan, Amir S.; Fiorotto, Marta L.; Hill, Leigh-Anne; Malone, P. Brandon; Cummings, Kathleen K.; Parghi, Deena; Schwartz, Robert J.; Smith, Roy G.; Draghia-Akli, Ruxandra

    2002-01-01

    The im electroporated injection of a protease-resistant GH-releasing hormone cDNA into rat dams at 16 d gestation resulted in enhanced long-term growth of the F(1) offspring. The offspring were significantly heavier by 2 wk of age, and the difference was sustained to 10 wk of age. Consistent with their augmented growth, the plasma IGF-I concentration of the F(1) progeny was increased significantly. The pituitary gland of the offspring was significantly heavier and contained an increased number of somatotrophs and PRL-secreting cells, which is indicative of modification of cell lineage differentiation. These unique findings demonstrate that enhanced GH-releasing hormone expression in pregnant dams can result in intergenerational growth promotion by altering development of the pituitary gland in the offspring.

  13. Photodetector with enhanced light absorption

    DOEpatents

    Kane, James

    1985-01-01

    A photodetector including a light transmissive electrically conducting layer having a textured surface with a semiconductor body thereon. This layer traps incident light thereby enhancing the absorption of light by the semiconductor body. A photodetector comprising a textured light transmissive electrically conducting layer of SnO.sub.2 and a body of hydrogenated amorphous silicon has a conversion efficiency about fifty percent greater than that of comparative cells. The invention also includes a method of fabricating the photodetector of the invention.

  14. Technology Education Professional Enhancement Project

    NASA Technical Reports Server (NTRS)

    Hughes, Thomas A., Jr.

    1996-01-01

    The two goals of this project are: the use of integrative field of aerospace technology to enhance the content and instruction delivered by math, science, and technology teachers through the development of a new publication entitled NASA Technology Today, and to develop a rationale and structure for the study of technology, which establishes the foundation for developing technology education standards and programs of the future.

  15. Enhancing Soundtracks From Old Movies

    NASA Technical Reports Server (NTRS)

    Frazer, Robert E.

    1992-01-01

    Proposed system enhances soundtracks of old movies. Signal on optical soundtrack of film digitized and processed to reduce noise and improve quality; timing signals added, and signal recorded on compact disk. Digital comparator and voltage-controlled oscillator synchronizes speed of film-drive motor and compact disk motor. Frame-coded detector reads binary frame-identifying marks on film. Digital comparator generates error signal if marks on film do not match those on compact disk.

  16. Enhancing Centrifugal Separation With Electrophoresis

    NASA Technical Reports Server (NTRS)

    Herrmann, F. T.

    1986-01-01

    Separation of biological cells by coil-planet centrifuge enhanced by electrophoresis. By itself, coil-planet centrifuge offers relatively gentle method of separating cells under low centrifugal force in physiological medium that keeps cells alive. With addition of voltage gradient to separation column of centrifuge, separation still gentle but faster and more complete. Since separation apparatus contains no rotary seal, probability of leakage, contamination, corrosion, and short circuits reduced.

  17. Preactivated thiomers: Permeation enhancing properties

    PubMed Central

    Wang, Xueqing; Iqbal, Javed; Rahmat, Deni; Bernkop-Schnürch, Andreas

    2012-01-01

    The study was aimed to prepare a series of poly(acrylic acid)-cysteine-2-mercaptonicotinic acid conjugates (preactivated thiomers) and to evaluate the influence of molecular mass or degree of preactivation with 2-mercaptonicotinic acid (2MNA) on their permeation enhancing properties. Preactivated thiomers with different molecular mass and different degree of preactivation were synthesized and categorized on the basis of their molecular mass and degree of preactivation as PAA100-Cys-2MNA (h), PAA250-Cys-2MNA (h), PAA450-Cys-2MNA (h), PAA450-Cys-2MNA (m) and PAA450-Cys-2MNA (l). In vitro permeation studies, the permeation enhancement ability for preactivated thiomers was ranked as PAA450-Cys-2MNA (h) > PAA250-Cys-2MNA (h) > PAA100-Cys-2MNA (h) on both Caco-2 cell monolayers and rat intestinal mucosa. Comparing the influence of degree of preactivation with 2MNA on permeation enhancement, the following order PAA450-Cys-2MNA (h) > PAA450-Cys-2MNA (m) ≈ PAA450-Cys-2MNA (l) on Caco-2 cell monolayers and PAA450-Cys-2MNA (m) > PAA450-Cys-2MNA (h) > PAA450-Cys-2MNA (l) on intestinal mucosa was observed. The Papp of sodium fluorescein was 5.08-fold improved on Caco-2 cell monolayers for PAA450-Cys-2MNA (h) and 2.46-fold improved on intestinal mucosa for PAA450-Cys-2MNA (m), respectively, in comparison to sodium fluorescein in buffer only. These results indicated that preactivated thiomers could be considered as a promising macromolecular permeation enhancing polymer for non-invasive drug administration. PMID:22960503

  18. CARE 3, Version 4 enhancements

    NASA Technical Reports Server (NTRS)

    Bryant, L. A.; Stiffler, J. J.

    1985-01-01

    The enhancements and error corrections to CARE III Version 4 are listed. All changes to Version 4 with the exception of the internal redundancy model were implemented in Version 5. Version 4 is the first public release version for execution on the CDC Cyber 170 series computers. Version 5 is the second release version and it is written in ANSI standard FORTRAN 77 for execution on the DEC VAX 11/700 series computers and many others.

  19. The Likelihood of Cognitive Enhancement

    PubMed Central

    Lynch, Gary; Palmer, Linda C.; Gall, Christine M.

    2011-01-01

    Whether drugs that enhance cognition in healthy individuals will appear in the near future has become a topic of considerable interest. We address this possibility using a three variable system (psychological effect, neurobiological mechanism, efficiency vs. capabilities) for classifying candidates. Ritalin and modafinil, two currently available compounds, operate on primary psychological states that in turn affect cognitive operations (attention, memory), but there is little evidence that these effects translate into improvements in complex cognitive processing. A second category of potential enhancers includes agents that improve memory encoding, generally without large changes in primary psychological states. Unfortunately, there is little information on how these compounds affect cognitive performance in standard psychological tests. Recent experiments have identified a number of sites at which memory drugs could, in principle, manipulate the cell biological systems underlying the learning-related long-term potentiation (LTP) effect; this may explain the remarkable diversity of memory promoting compounds. Indeed, many of these agents are known to have positive effects on LTP. A possible third category of enhancement drugs directed specifically at integrated cognitive operations is nearly empty. From a neurobiological perspective, two plausible candidate classes have emerged that both target the fast excitatory transmission responsible for communication within cortical networks. One acts on nicotinic receptors (alpha7, alpha4) that regulate release of the neurotransmitter glutamate while the other (‘ampakines’) allosterically modulates the glutamate receptors mediating the post-synaptic response (EPSCs). Brain imaging in primates has shown that ampakines expand cortical networks engaged by a complex task; coupled with behavioral data, these findings provide evidence for the possibility of generating new cognitive capabilities. Finally, we suggest that

  20. Enhancements to Sperry/NASTRAN

    NASA Technical Reports Server (NTRS)

    Koga, T.

    1986-01-01

    Reviewed is the enhancement to NASTRAN program performed by NUK (Nippon Univac Kaisha, Ltd.) added to Level 15.5. Features discussed include intermediate checkpoint-restart in triangular decomposition, I/O improvement, multibanked memory and new plate element. The first three improvements provide the capability to solve significantly large size problems, while the new elements release the analyst from the cumbersome work to constrain the singularities caused by the lack of stiffness of inplane rotation of old plate elements.

  1. Enhancing reproductive performance in mares.

    PubMed

    Scherzer, Jakob

    2010-01-01

    Reproductive performance in mares can be enhanced by various techniques. Protocols hastening the onset of follicular development help establish pregnancy in mares and ensure that foals are born early in the year. The time spent breeding mares can be reduced by synchronizing estrus and inducing ovulation. After successful fertilization of the oocyte, the developing embryo can survive in the uterus only if postbreeding endometritis, if present, is treated. PMID:20473845

  2. Haptoglobin Enhances Cardiac Transplant Rejection

    PubMed Central

    Shen, Hua; Heuzey, Elizabeth; Mori, Daniel; Wong, Christine; Colangelo, Christopher; Chung, Lisa M.; Bruce, Can; Slizovskiy, Ilya B.; Booth, Carmen J.; Kreisel, Daniel; Goldstein, Daniel R.

    2015-01-01

    Rationale Early graft inflammation enhances both acute and chronic rejection of heart transplants, but it is unclear how this inflammation is initiated. Objective To identify specific inflammatory modulators and determine their underlying molecular mechanisms after cardiac transplantation. Methods and Results We used a murine heterotopic cardiac transplant model to identify inflammatory modulators of early graft inflammation. Unbiased mass spectrometric analysis of cardiac tissue before and up to 72 hours after transplantation revealed that 22 proteins including haptoglobin, a known anti-oxidant, are significantly upregulated in our grafts. Through the use of haptoglobin deficient mice, we show that 80% of haptoglobin deficient recipients treated with peri-operative administration of the costimulatory blocking agent CTLA4 immunoglobulin exhibited > 100 days survival of full major histocompatibility complex mismatched allografts, whereas all similarly treated wild type recipients rejected their transplants by 21 days post transplantation. We found that haptoglobin modifies the intra-allograft inflammatory milieu by enhancing levels of the inflammatory cytokine IL-6 and the chemokine MIP-2 but impair levels of the immunosuppressive cytokine IL-10. Haptoglobin also enhances dendritic cell graft recruitment and augments anti-donor T cell responses. Moreover, we confirmed that the protein is present in human cardiac allograft specimens undergoing acute graft rejection. Conclusions Our findings provide new insights into the mechanisms of inflammation after cardiac transplantation and suggest that, in contrast to its prior reported anti-oxidant function in vascular inflammation, haptoglobin is an enhancer of inflammation after cardiac transplantation. Haptoglobin may also be a key component in other sterile inflammatory conditions. PMID:25801896

  3. How rotational vortices enhance transfers

    NASA Astrophysics Data System (ADS)

    Griffani, D.; Rognon, P.; Metzger, B.; Einav, I.

    2013-09-01

    Inspired by recent observations of granular flow, we examine how rotational vortices contribute to heat or mass transfer enhancement in a fluid. We use a tracer method to simulate both diffusion and advection in systems of differing intrinsic diffusivities D0, vortex sizes R, vortex rotation frequencies f, and vortex lifetimes ℓ. The results reveal that these systems exhibit an effective diffusive behavior, characterized by an effective diffusivity Deff. A striking finding is the existence of two regimes, dichotomised by the Péclet number Pe = R2f/D0. When the Péclet number is less than one, there is no transfer enhancement, Deff = D0. For higher values, vortices produce some transfer enhancement with a corresponding power law Deff/D0 ≈ Pen. The power n ranges from a lower bound of 0.5 for stationary vortices of lifetime infinity, to an upper bound of 1 for vortices of lifetimes shorter than half a rotation. This difference is attributed to two different internal mechanisms involving the coupling of diffusion and advection. These results could provide new insights on the transfer properties of fluid systems comprising rotational vortices, such as granular materials, suspensions, foams, and emulsions, as well as low Reynolds number stirred flows.

  4. Enhancement classification of galaxy images

    NASA Astrophysics Data System (ADS)

    Jenkinson, John

    With the advent of astronomical imaging technology developments, and the increased capacity of digital storage, the production of photographic atlases of the night sky have begun to generate volumes of data which need to be processed autonomously. As part of the Tonantzintla Digital Sky Survey construction, the present work involves software development for the digital image processing of astronomical images, in particular operations that preface feature extraction and classification. Recognition of galaxies in these images is the primary objective of the present work. Many galaxy images have poor resolution or contain faint galaxy features, resulting in the misclassification of galaxies. An enhancement of these images by the method of the Heap transform is proposed, and experimental results are provided which demonstrate the image enhancement to improve the presence of faint galaxy features thereby improving classification accuracy. The feature extraction was performed using morphological features that have been widely used in previous automated galaxy investigations. Principal component analysis was applied to the original and enhanced data sets for a performance comparison between the original and reduced features spaces. Classification was performed by the Support Vector Machine learning algorithm.

  5. Large-mode enhancement cavities.

    PubMed

    Carstens, Henning; Holzberger, Simon; Kaster, Jan; Weitenberg, Johannes; Pervak, Volodymyr; Apolonski, Alexander; Fill, Ernst; Krausz, Ferenc; Pupeza, Ioachim

    2013-05-01

    In passive enhancement cavities the achievable power level is limited by mirror damage. Here, we address the design of robust optical resonators with large spot sizes on all mirrors, a measure that promises to mitigate this limitation by decreasing both the intensity and the thermal gradient on the mirror surfaces. We introduce a misalignment sensitivity metric to evaluate the robustness of resonator designs. We identify the standard bow-tie resonator operated close to the inner stability edge as the most robust large-mode cavity and implement this cavity with two spherical mirrors with 600 mm radius of curvature, two plane mirrors and a round trip length of 1.2 m, demonstrating a stable power enhancement of near-infrared laser light by a factor of 2000. Beam radii of 5.7 mm × 2.6 mm (sagittal × tangential 1/e(2) intensity radius) on all mirrors are obtained. We propose a simple all-reflective ellipticity compensation scheme. This will enable a significant increase of the attainable power and intensity levels in enhancement cavities. PMID:23670017

  6. Polyphosphate enhances fibrin clot structure

    PubMed Central

    Smith, Stephanie A.

    2008-01-01

    Polyphosphate, a linear polymer of inorganic phosphate, is present in platelet dense granules and is secreted on platelet activation. We recently reported that polyphosphate is a potent hemostatic regulator, serving to activate the contact pathway of blood clotting and accelerate factor V activation. Because polyphosphate did not alter thrombin clotting times, it appeared to exert all its procoagulant actions upstream of thrombin. We now report that polyphosphate enhances fibrin clot structure in a calcium-dependent manner. Fibrin clots formed in the presence of polyphosphate had up to 3-fold higher turbidity, had higher mass-length ratios, and exhibited thicker fibers in scanning electron micrographs. The ability of polyphosphate to enhance fibrin clot turbidity was independent of factor XIIIa activity. When plasmin or a combination of plasminogen and tissue plasminogen activators were included in clotting reactions, fibrin clots formed in the presence of polyphosphate exhibited prolonged clot lysis times. Release of polyphosphate from activated platelets or infectious microorganisms may play an important role in modulating fibrin clot structure and increasing its resistance to fibrinolysis. Polyphosphate may also be useful in enhancing the structure of surgical fibrin sealants. PMID:18544683

  7. Dispersion-Enhanced Laser Gyroscope

    NASA Technical Reports Server (NTRS)

    Smith, David D.; Chang, Hongrok; Arissian, L.; Diels, J. C.

    2008-01-01

    We analyze the effect of a highly dispersive element placed inside a modulated optical cavity on the frequency and amplitude of the output modulation to determine the conditions for enhanced gyroscopic sensitivities. The element is treated as both a phase and amplitude filter, and the time-dependence of the cavity field is considered. Both atomic gases (two-level and multi-level) and optical resonators (single and coupled) are considered and compared as dispersive elements. We find that it is possible to simultaneously enhance the gyro scale factor sensitivity and suppress the dead band by using an element with anomalous dispersion that has greater loss at the carrier frequency than at the side-band frequencies, i.e., an element that simultaneously pushes and intensifies the perturbed cavity modes, e.g. a two-level absorber or an under-coupled optical resonator. The sensitivity enhancement is inversely proportional to the effective group index, becoming infinite at a group index of zero. However, the number of round trips required to reach a steady-state also becomes infinite when the group index is zero (or two). For even larger dispersions a steady-state cannot be achieved, and nonlinear dynamic effects such as bistability and periodic oscillations are predicted in the gyro response.

  8. Integrating diverse datasets improves developmental enhancer prediction.

    PubMed

    Erwin, Genevieve D; Oksenberg, Nir; Truty, Rebecca M; Kostka, Dennis; Murphy, Karl K; Ahituv, Nadav; Pollard, Katherine S; Capra, John A

    2014-06-01

    Gene-regulatory enhancers have been identified using various approaches, including evolutionary conservation, regulatory protein binding, chromatin modifications, and DNA sequence motifs. To integrate these different approaches, we developed EnhancerFinder, a two-step method for distinguishing developmental enhancers from the genomic background and then predicting their tissue specificity. EnhancerFinder uses a multiple kernel learning approach to integrate DNA sequence motifs, evolutionary patterns, and diverse functional genomics datasets from a variety of cell types. In contrast with prediction approaches that define enhancers based on histone marks or p300 sites from a single cell line, we trained EnhancerFinder on hundreds of experimentally verified human developmental enhancers from the VISTA Enhancer Browser. We comprehensively evaluated EnhancerFinder using cross validation and found that our integrative method improves the identification of enhancers over approaches that consider a single type of data, such as sequence motifs, evolutionary conservation, or the binding of enhancer-associated proteins. We find that VISTA enhancers active in embryonic heart are easier to identify than enhancers active in several other embryonic tissues, likely due to their uniquely high GC content. We applied EnhancerFinder to the entire human genome and predicted 84,301 developmental enhancers and their tissue specificity. These predictions provide specific functional annotations for large amounts of human non-coding DNA, and are significantly enriched near genes with annotated roles in their predicted tissues and lead SNPs from genome-wide association studies. We demonstrate the utility of EnhancerFinder predictions through in vivo validation of novel embryonic gene regulatory enhancers from three developmental transcription factor loci. Our genome-wide developmental enhancer predictions are freely available as a UCSC Genome Browser track, which we hope will enable

  9. Integrating Diverse Datasets Improves Developmental Enhancer Prediction

    PubMed Central

    Erwin, Genevieve D.; Oksenberg, Nir; Truty, Rebecca M.; Kostka, Dennis; Murphy, Karl K.; Ahituv, Nadav; Pollard, Katherine S.; Capra, John A.

    2014-01-01

    Gene-regulatory enhancers have been identified using various approaches, including evolutionary conservation, regulatory protein binding, chromatin modifications, and DNA sequence motifs. To integrate these different approaches, we developed EnhancerFinder, a two-step method for distinguishing developmental enhancers from the genomic background and then predicting their tissue specificity. EnhancerFinder uses a multiple kernel learning approach to integrate DNA sequence motifs, evolutionary patterns, and diverse functional genomics datasets from a variety of cell types. In contrast with prediction approaches that define enhancers based on histone marks or p300 sites from a single cell line, we trained EnhancerFinder on hundreds of experimentally verified human developmental enhancers from the VISTA Enhancer Browser. We comprehensively evaluated EnhancerFinder using cross validation and found that our integrative method improves the identification of enhancers over approaches that consider a single type of data, such as sequence motifs, evolutionary conservation, or the binding of enhancer-associated proteins. We find that VISTA enhancers active in embryonic heart are easier to identify than enhancers active in several other embryonic tissues, likely due to their uniquely high GC content. We applied EnhancerFinder to the entire human genome and predicted 84,301 developmental enhancers and their tissue specificity. These predictions provide specific functional annotations for large amounts of human non-coding DNA, and are significantly enriched near genes with annotated roles in their predicted tissues and lead SNPs from genome-wide association studies. We demonstrate the utility of EnhancerFinder predictions through in vivo validation of novel embryonic gene regulatory enhancers from three developmental transcription factor loci. Our genome-wide developmental enhancer predictions are freely available as a UCSC Genome Browser track, which we hope will enable

  10. Enhanced live cell imaging via photonic crystal enhanced fluorescence microscopy.

    PubMed

    Chen, Weili; Long, Kenneth D; Yu, Hojeong; Tan, Yafang; Choi, Ji Sun; Harley, Brendan A; Cunningham, Brian T

    2014-11-21

    We demonstrate photonic crystal enhanced fluorescence (PCEF) microscopy as a surface-specific fluorescence imaging technique to study the adhesion of live cells by visualizing variations in cell-substrate gap distance. This approach utilizes a photonic crystal surface incorporated into a standard microscope slide as the substrate for cell adhesion, and a microscope integrated with a custom illumination source as the detection instrument. When illuminated with a monochromatic light source, angle-specific optical resonances supported by the photonic crystal enable efficient excitation of surface-confined and amplified electromagnetic fields when excited at an on-resonance condition, while no field enhancement occurs when the same photonic crystal is illuminated in an off-resonance state. By mapping the fluorescence enhancement factor for fluorophore-tagged cellular components between on- and off-resonance states and comparing the results to numerical calculations, the vertical distance of labelled cellular components from the photonic crystal substrate can be estimated, providing critical and quantitative information regarding the spatial distribution of the specific components of cells attaching to a surface. As an initial demonstration of the concept, 3T3 fibroblast cells were grown on fibronectin-coated photonic crystals with fluorophore-labelled plasma membrane or nucleus. We demonstrate that PCEF microscopy is capable of providing information about the spatial distribution of cell-surface interactions at the single-cell level that is not available from other existing forms of microscopy, and that the approach is amenable to large fields of view, without the need for coupling prisms, coupling fluids, or special microscope objectives. PMID:25265458

  11. Enhanced live cell imaging via photonic crystal enhanced fluorescence microscopy†

    PubMed Central

    Chen, Weili; Long, Kenneth D.; Yu, Hojeong; Tan, Yafang; Choi, Ji Sun; Harley, Brendan A.; Cunningham, Brian T.

    2014-01-01

    We demonstrate photonic crystal enhanced fluorescence (PCEF) microscopy as a surface-specific fluorescence imaging technique to study the adhesion of live cells by visualizing variations in cell-substrate gap distance. This approach utilizes a photonic crystal surface incorporated into a standard microscope slide as the substrate for cell adhesion, and a microscope integrated with a custom illumination source as the detection instrument. When illuminated with a monochromatic light source, angle-specific optical resonances supported by the photonic crystal enable efficient excitation of surface-confined and amplified electromagnetic fields when excited at an on-resonance condition, while no field enhancement occurs when the same photonic crystal is illuminated in an off-resonance state. By mapping the fluorescence enhancement factor for fluorophore-tagged cellular components between on- and off-resonance states and comparing the results to numerical calculations, the vertical distance of labelled cellular components from the photonic crystal substrate can be estimated, providing critical and quantitative information regarding the spatial distribution of the specific components of cells attaching to a surface. As an initial demonstration of the concept, 3T3 fibroblast cells were grown on fibronectin-coated photonic crystals with fluorophore-labelled plasma membrane or nucleus. We demonstrate that PCEF microscopy is capable of providing information about the spatial distribution of cell-surface interactions at the single-cell level that is not available from other existing forms of microscopy, and that the approach is amenable to large fields of view, without the need for coupling prisms, coupling fluids, or special microscope objectives. PMID:25265458

  12. Freshwater aspects of anadromous salmonid enhancement

    USGS Publications Warehouse

    Gould, Rowan W.

    1982-01-01

    Freshwater enhancement of anadromous salmonid populations has been practiced in the United States and Canada since the late 1800's. Reduction of natural spawning habitat and increasing fishing pressure make artificial enhancement a possible alternative to declining populations. Enhancement of anadromous salmonids involved improvement of the natural environment and reducing natural mortality. Methods of enhancement include fishways, spawning and rearing channels, stream rehabilitation, lake fertilization, environmental management, and artificial propagation techniques. Five Pacific salmon species and steelhead trout are commonly enhanced, primarily in watershed entering the Pacific Ocean and Great Lakes. Enhancement efforts contribute heavily to a commercial and sport industry realizing over $1.5 billion.

  13. Chronic glucolipotoxic conditions in pancreatic islets impair insulin secretion due to dysregulated calcium dynamics, glucose responsiveness and mitochondrial activity

    PubMed Central

    2013-01-01

    Background In the progression towards diabetes, glucolipotoxicity is one of the main causes of pancreatic beta cell pathology. The aim of this study was to examine the in vitro effects of chronic glucolipotoxic conditions on cellular responses in pancreatic islets, including glucose and fat metabolism, Calcium mobilization, insulin secretion and insulin content. Results Exposure of islets to chronic glucolipotoxic conditions decreased glucose stimulated insulin secretion in vitro. Reduced protein levels of Glut2/slc2a2, and decreased glucokinase and pyruvate carboxylase mRNA levels indicated a significant lowering in glucose sensing. Concomitantly, both fatty acid uptake and triglyceride accumulation increased significantly while fatty acid oxidation decreased. This general suppression in glucose metabolism correlated well with a decrease in mitochondrial number and activity, reduction in cellular ATP content and dampening of the TCA cycle. Further, we also observed a decrease in IP3 levels and lower Calcium mobilization in response to glucose. Importantly, chronic glucolipotoxic conditions in vitro decreased insulin gene expression, insulin content, insulin granule docking (to the plasma membrane) and insulin secretion. Conclusions Our results present an integrated view of the effects of chronic glucolipotoxic conditions on known and novel signaling events, in vitro, that results in reduced glucose responsiveness and insulin secretion. PMID:23815372

  14. Glucose and lipid metabolism in the pancreas of rainbow trout is regulated at the molecular level by nutritional status and carbohydrate intake.

    PubMed

    Polakof, Sergio; Skiba-Cassy, Sandrine; Kaushik, Sadasivam; Seiliez, Iban; Soengas, Jose Luis; Panserat, Stephane

    2012-05-01

    Glucose and lipid metabolism in pancreatic islet organs is poorly characterized. In the present study, using as a model the carnivorous rainbow trout, a glucose-intolerant fish, we assessed mRNA expression levels of several genes involved in glucose and lipid metabolism (including ATP-citrate lyase; carnitine palmitoyltransferase-1 isoforms, CPT; the mitochondrial isoform of the phosphoenolpyrutave carboxykinase, mPEPCK and pyruvate kinase, PK) and glucosensing (glucose transporter type 2, Glut2; glucokinase, GK and the potassium channel, K(ATP)) in Brockmann bodies. We evaluated the response of these parameters to changes in feeding status (food deprived vs. fed fish) as well as to changes in the amount of carbohydrate (dextrin) in the diet. A general inhibition of the glycolytic (including the glucosensing marker GK) and β-oxidation pathways was found when comparing fed versus food-deprived fish. When comparing fish feeding on either low- or high-carbohydrate diets, we found that some genes related to lipid metabolism were more controlled by the feeding status than by the carbohydrate content (fatty acid synthase, CPTs). Findings are discussed in the context of pancreatic regulation of glucose and lipid metabolism in fish, and show that while trout pancreatic metabolism can partially adapt to a high-carbohydrate diet, some of the molecular actors studied seem to be poorly regulated (K(ATP)) and may contribute to the glucose intolerance observed in this species when fed high-carbohydrate diets. PMID:22203338

  15. Glucose and hypothalamic astrocytes: More than a fueling role?

    PubMed

    Leloup, C; Allard, C; Carneiro, L; Fioramonti, X; Collins, S; Pénicaud, L

    2016-05-26

    Brain plays a central role in energy homeostasis continuously integrating numerous peripheral signals such as circulating nutrients, and in particular blood glucose level, a variable that must be highly regulated. Then, the brain orchestrates adaptive responses to modulate food intake and peripheral organs activity in order to achieve the fine tuning of glycemia. More than fifty years ago, the presence of glucose-sensitive neurons was discovered in the hypothalamus, but what makes them specific and identifiable still remains disconnected from their electrophysiological signature. On the other hand, astrocytes represent the major class of macroglial cells and are now recognized to support an increasing number of neuronal functions. One of these functions consists in the regulation of energy homeostasis through neuronal fueling and nutrient sensing. Twenty years ago, we discovered that the glucose transporter GLUT2, the canonical "glucosensor" of the pancreatic beta-cell together with the glucokinase, was also present in astrocytes and participated in hypothalamic glucose sensing. Since then, many studies have identified other actors and emphasized the astroglial participation in this mechanism. Growing evidence suggest that astrocytes form a complex network and have to be considered as spatially coordinated and regulated metabolic units. In this review we aim to provide an updated view of the molecular and respective cellular pathways involved in hypothalamic glucose sensing, and their relevance in physiological and pathological states. PMID:26071958

  16. DENdb: database of integrated human enhancers

    PubMed Central

    Ashoor, Haitham; Kleftogiannis, Dimitrios; Radovanovic, Aleksandar; Bajic, Vladimir B.

    2015-01-01

    Enhancers are cis-acting DNA regulatory regions that play a key role in distal control of transcriptional activities. Identification of enhancers, coupled with a comprehensive functional analysis of their properties, could improve our understanding of complex gene transcription mechanisms and gene regulation processes in general. We developed DENdb, a centralized on-line repository of predicted enhancers derived from multiple human cell-lines. DENdb integrates enhancers predicted by five different methods generating an enriched catalogue of putative enhancers for each of the analysed cell-lines. DENdb provides information about the overlap of enhancers with DNase I hypersensitive regions, ChIP-seq regions of a number of transcription factors and transcription factor binding motifs, means to explore enhancer interactions with DNA using several chromatin interaction assays and enhancer neighbouring genes. DENdb is designed as a relational database that facilitates fast and efficient searching, browsing and visualization of information. Database URL: http://www.cbrc.kaust.edu.sa/dendb/ PMID:26342387

  17. Helium and Enhanced Image of the Sun

    NASA Video Gallery

    This video blinks between an image in Helium and an enhanced image. The original image is from AIA on SDO and the enhanced image was created at the LM Solar and Astrophysics Laboratory (LMSAL) by D...

  18. ATAMM enhancement and multiprocessor performance evaluation

    NASA Technical Reports Server (NTRS)

    Stoughton, John W.; Mielke, Roland R.; Som, Sukhamoy; Obando, Rodrigo; Malekpour, Mahyar R.; Jones, Robert L., III; Mandala, Brij Mohan V.

    1991-01-01

    ATAMM (Algorithm To Architecture Mapping Model) enhancement and multiprocessor performance evaluation is discussed. The following topics are included: the ATAMM model; ATAMM enhancement; ADM (Advanced Development Model) implementation of ATAMM; and ATAMM support tools.

  19. Permeability enhancement by shock cooling

    NASA Astrophysics Data System (ADS)

    Griffiths, Luke; Heap, Michael; Reuschlé, Thierry; Baud, Patrick; Schmittbuhl, Jean

    2015-04-01

    The permeability of an efficient reservoir, e.g. a geothermal reservoir, should be sufficient to permit the circulation of fluids. Generally speaking, permeability decreases over the life cycle of the geothermal system. As a result, is usually necessary to artificially maintain and enhance the natural permeability of these systems. One of the methods of enhancement -- studied here -- is thermal stimulation (injecting cold water at low pressure). This goal of this method is to encourage new thermal cracks within the reservoir host rocks, thereby increasing reservoir permeability. To investigate the development of thermal microcracking in the laboratory we selected two granites: a fine-grained (Garibaldi Grey granite, grain size = 0.5 mm) and a course-grained granite (Lanhelin granite, grain size = 2 mm). Both granites have an initial porosity of about 1%. Our samples were heated to a range of temperatures (100-1000 °C) and were either cooled slowly (1 °C/min) or shock cooled (100 °C/s). A systematic microstructural (2D crack area density, using standard stereological techniques, and 3D BET specific surface area measurements) and rock physical property (porosity, P-wave velocity, uniaxial compressive strength, and permeability) analysis was undertaken to understand the influence of slow and shock cooling on our reservoir granites. Microstructurally, we observe that the 2D crack surface area per unit volume and the specific surface area increase as a result of thermal stressing, and, for the same maximum temperature, crack surface area is higher in the shock cooled samples. This observation is echoed by our rock physical property measurements: we see greater changes for the shock cooled samples. We can conclude that shock cooling is an extremely efficient method of generating thermal microcracks and modifying rock physical properties. Our study highlights that thermal treatments are likely to be an efficient method for the "matrix" permeability enhancement of

  20. Micro-bubble enhanced HIFU

    NASA Astrophysics Data System (ADS)

    Kajiyama, K.; Yoshinaka, K.; Takagi, S.; Matsumoto, Y.

    2010-01-01

    High intensity focused ultrasound (HIFU) treatment that employs microbubbles to provide enhanced heating has been investigated in order to develop a less invasive and more rapid tumor ablation therapy. It has been demonstrated that microbubbles have significant effects on heating enhancement in vitro and in vivo experiments, however ultrasound propagation could be disturbed when there are too many microbubbles between the transducer and the focus. In this study, we develop a method to make a clear pass way for obtaining enhanced heating by using microbubbles just at the focus, thus avoiding heating on the pass way from the transducer to the target region. In this method, microbubbles are destroyed in front of the HIFU focus (on the transducer side) by irradiating a intense burst wave of microsecond order, before irradiating the ultrasound waves for heating the target region. The experiment is conducted in a medium of a polyacrylamide gel containing microbubbles, and a temperature-sensing liquid crystal sheet is set in the focus to observe the temperature distribution. The ultrasound frequency was 2.2 MHz and the intensity was 5000 W/cm2, and 20 burst waves were irradiated at pulse repetition frequency of 1 kHz. The number of wave pulses was varied. The continuous-wave frequency, intensity and irradiation time are 2.2 MHz, 1000 W/cm2 and 60 sec, respectively. As the number of pulses increased, the heating region moves from the transducer side to the focus. This is because microbubbles in front of the focus are destroyed and the ultrasound propagates around the target position effectively. These results suggest that the microbubble distribution and the heating position in the developed HIFU system can be controlled.

  1. Countermeasures to Enhance Sensorimotor Adaptability

    NASA Technical Reports Server (NTRS)

    Bloomberg, J. J.; Peters, B. T.; Mulavara, A. P.; Brady, R. A.; Batson, C. C.; Miller, C. A.; Cohen, H. S.

    2011-01-01

    During exploration-class missions, sensorimotor disturbances may lead to disruption in the ability to ambulate and perform functional tasks during the initial introduction to a novel gravitational environment following a landing on a planetary surface. The goal of our current project is to develop a sensorimotor adaptability (SA) training program to facilitate rapid adaptation to novel gravitational environments. We have developed a unique training system comprised of a treadmill placed on a motion-base facing a virtual visual scene that provides an unstable walking surface combined with incongruent visual flow designed to enhance sensorimotor adaptability. We have conducted a series of studies that have shown: Training using a combination of modified visual flow and support surface motion during treadmill walking enhances locomotor adaptability to a novel sensorimotor environment. Trained individuals become more proficient at performing multiple competing tasks while walking during adaptation to novel discordant sensorimotor conditions. Trained subjects can retain their increased level of adaptability over a six months period. SA training is effective in producing increased adaptability in a more complex over-ground ambulatory task on an obstacle course. This confirms that for a complex task like walking, treadmill training contains enough of the critical features of overground walking to be an effective training modality. The structure of individual training sessions can be optimized to promote fast/strategic motor learning. Training sessions that each contain short-duration exposures to multiple perturbation stimuli allows subjects to acquire a greater ability to rapidly reorganize appropriate response strategies when encountering a novel sensory environment. Individual sensory biases (i.e. increased visual dependency) can predict adaptive responses to novel sensory environments suggesting that customized training prescriptions can be developed to enhance

  2. Intralymphatic immunization enhances DNA vaccination

    NASA Astrophysics Data System (ADS)

    Maloy, Kevin J.; Erdmann, Iris; Basch, Veronique; Sierro, Sophie; Kramps, Thomas A.; Zinkernagel, Rolf M.; Oehen, Stefan; Kündig, Thomas M.

    2001-03-01

    Although DNA vaccines have been shown to elicit potent immune responses in animal models, initial clinical trials in humans have been disappointing, highlighting a need to optimize their immunogenicity. Naked DNA vaccines are usually administered either i.m. or intradermally. The current study shows that immunization with naked DNA by direct injection into a peripheral lymph node enhances immunogenicity by 100- to 1,000-fold, inducing strong and biologically relevant CD8+ cytotoxic T lymphocyte responses. Because injection directly into a lymph node is a rapid and easy procedure in humans, these results have important clinical implications for DNA vaccination.

  3. Enhanced thermopower of gated silicene

    NASA Astrophysics Data System (ADS)

    Yan, Yonghong; Wu, Haifei; Jiang, Feng; Zhao, Hui

    2013-11-01

    We theoretically investigate the thermopower of silicene systems in an external electric field perpendicular to the silicene sheet. In the absence of the field, we estimate that the thermopower of pure silicene is of order ˜80 μV/K. When a finite field is applied, a comparatively big band gap is opened and the thermopower is thus enhanced by several times as compared with the case without the field. The effect of disorder is also studied, and we find only minimal difference.

  4. Enhancing professionalism at GPU Nuclear

    SciTech Connect

    Coe, R.P. )

    1992-01-01

    Late in 1988, GPU Nuclear embarked on a major program aimed at enhancing professionalism at its Oyster Creek and Three Mile Island nuclear generating stations. The program was also to include its corporate headquarters in Parsippany, New Jersey. The overall program was to take several directions, including on-site degree programs, a sabbatical leave-type program for personnel to finish college degrees, advanced technical training for licensed staff, career progression for senior reactor operators, and expanded teamwork and leadership training for control room crew. The largest portion of this initiative was the development and delivery of professionalism training to the nearly 2,000 people at both nuclear generating sites.

  5. Conservation enhancement programs add up

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    A new partnership between the U.S. federal government and the State of Delaware will provide 10 million to improve the water quality of the watersheds of the Chesapeake Bay, Delaware Bay, and other water bodies.The agreement, which establishes the Delaware Conservation Reserve Enhancement Program (CREP), marks the eighth such partnership established since 1997 and brings the total U.S. Department of Agriculture (USDA) investment in CREP programs to 1.45 billion for improving water quality and restoring wildlife habitat. USDA is expected to pay up to $8 million to enroll up to 6,000 acres in the Delaware CREP program.

  6. Conservation enhancement programs add up

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    A new partnership between the U.S. federal government and the State of Delaware will provide $10 million to improve the water quality of the watersheds of the Chesapeake Bay, Delaware Bay, and other water bodies.The agreement, which establishes the Delaware Conservation Reserve Enhancement Program (CREP), marks the eighth such partnership established since 1997 and brings the total U.S. Department of Agriculture (USDA) investment in CREP programs to $1.45 billion for improving water quality and restoring wildlife habitat. USDA is expected to pay up to $8 million to enroll up to 6,000 acres in the Delaware CREP program.

  7. Enhanced radiation resistant fiber optics

    DOEpatents

    Lyons, P.B.; Looney, L.D.

    1993-11-30

    A process for producing an optical fiber having enhanced radiation resistance is provided, the process including maintaining an optical fiber within a hydrogen-containing atmosphere for sufficient time to yield a hydrogen-permeated optical fiber having an elevated internal hydrogen concentration, and irradiating the hydrogen-permeated optical fiber at a time while the optical fiber has an elevated internal hydrogen concentration with a source of ionizing radiation. The radiation source is typically a cobalt-60 source and the fiber is pre-irradiated with a dose level up to about 1000 kilorads of radiation. 4 figures.

  8. Enhanced radiation resistant fiber optics

    DOEpatents

    Lyons, Peter B.; Looney, Larry D.

    1993-01-01

    A process for producing an optical fiber having enhanced radiation resitance is provided, the process including maintaining an optical fiber within a hydrogen-containing atmosphere for sufficient time to yield a hydrogen-permeated optical fiber having an elevated internal hydrogen concentration, and irradiating the hydrogen-permeated optical fiber at a time while the optical fiber has an elevated internal hydrogen concentration with a source of ionizing radiation. The radiation source is typically a cobalt-60 source and the fiber is pre-irradiated with a dose level up to about 1000 kilorads of radiation.

  9. Feedback enhanced plasma spray tool

    DOEpatents

    Gevelber, Michael Alan; Wroblewski, Donald Edward; Fincke, James Russell; Swank, William David; Haggard, Delon C.; Bewley, Randy Lee

    2005-11-22

    An improved automatic feedback control scheme enhances plasma spraying of powdered material through reduction of process variability and providing better ability to engineer coating structure. The present inventors discovered that controlling centroid position of the spatial distribution along with other output parameters, such as particle temperature, particle velocity, and molten mass flux rate, vastly increases control over the sprayed coating structure, including vertical and horizontal cracks, voids, and porosity. It also allows improved control over graded layers or compositionally varying layers of material, reduces variations, including variation in coating thickness, and allows increasing deposition rate. Various measurement and system control schemes are provided.

  10. Computer Program Helps Enhance Images

    NASA Technical Reports Server (NTRS)

    Stanfill, Daniel F., IV

    1994-01-01

    Pixel Pusher is Macintosh application program for viewing and performing minor enhancements on imagery. Works with color images digitized to 8 bits. Reads image files in JPL's two primary image formats VICAR and PDS as well as in Macintosh PICT format. VICAR (NPO-18076) handles array of image-processing capabilities used for variety of applications, including processing of biomedical images, cartography, imaging of Earth resources, and geological exploration. Pixel Pusher also imports color lookup tables in VICAR format for viewing images in pseudocolor (256 colors). Written in Symantec's Think C.

  11. Enhancement of polyisoprene latex production

    NASA Technical Reports Server (NTRS)

    Bauman, Albert J. (Inventor)

    1979-01-01

    Production of high molecular weight polyisoprene latex is enhanced by administering to plants, particularly Guayule Plants, an amine containing at least one two-carbon chain substituent and preferably substituted trialkylamine of the general structure: ##STR1## where R.sub.4, R.sub.5 and R.sub.6 are alkyl, preferably ethyl and at least one of R.sub.4, R.sub.5 and R.sub.6 is preferably an electron withdrawing group substituted aryloxy or arylthio ethyl group.

  12. Ferromagnetic enhanced inductive plasma sources

    NASA Astrophysics Data System (ADS)

    Godyak, Valery

    2013-07-01

    The subject of this paper is the review of inductively coupled plasma (ICP) sources enhanced with ferromagnetic cores, FMICP, found in various applications, including plasma fusion, space propulsion, light sources, plasma chemistry and plasma processing of materials. The history of FMICP, early attempts for their realization, some recent developments and examples of successful FMICP devices are given here. A comparative study of FMICPs with conventional ICPs demonstrates their certain advantages in power transfer efficiency, power factor and their ability to operate without rf plasma potentials at low plasma densities and with small gaps, while effectively controlling plasma density profile.

  13. Nutritional Supplements to Enhance Recovery

    NASA Astrophysics Data System (ADS)

    Ziegenfuss, Tim N.; Landis, Jamie; Greenwood, Mike

    The ability to recover from intense exercise often separates good athletes from great ones. In the past, "recovery" often simply included rest, physical modalities (e.g., massage, hydration therapy) and meeting basic nutritional needs for fluid and energy intake. Today, athletes have a number of additional options to help them recover from high intensity training, one of which includes the judicious use of dietary supplements. This chapter briefly reviews nutritional strategies that have a strong theoretical background for enhancing rehydration/electrolyte balance, replenishing energy reserves, minimizing oxidative damage, and stimulating muscle repair.

  14. Enhanced Master Controller Unit Tester

    NASA Technical Reports Server (NTRS)

    Benson, Patricia; Johnson, Yvette; Johnson, Brian; Williams, Philip; Burton, Geoffrey; McCoy, Anthony

    2007-01-01

    The Enhanced Master Controller Unit Tester (EMUT) software is a tool for development and testing of software for a master controller (MC) flight computer. The primary function of the EMUT software is to simulate interfaces between the MC computer and external analog and digital circuitry (including other computers) in a rack of equipment to be used in scientific experiments. The simulations span the range of nominal, off-nominal, and erroneous operational conditions, enabling the testing of MC software before all the equipment becomes available.

  15. Privacy-enhanced electronic mail

    NASA Astrophysics Data System (ADS)

    Bishop, Matt

    1990-06-01

    The security of electronic mail sent through the Internet may be described in exactly three words: there is none. The Privacy and Security Research Group has recommended implementing mechanisms designed to provide security enhancements. The first set of mechanisms provides a protocol to provide privacy, integrity, and authentication for electronic mail; the second provides a certificate-based key management infrastructure to support key distribution throughout the internet, to support the first set of mechanisms. These mechanisms are described, as well as the reasons behind their selection and how these mechanisms can be used to provide some measure of security in the exchange of electronic mail.

  16. Elastic mismatch enhances cell motility

    NASA Astrophysics Data System (ADS)

    Bresler, Yony; Palmieri, Benoit; Grant, Martin

    In recent years, the study of physics phenomena in cancer has drawn considerable attention. In cancer metastasis, a soft cancer cell leaves the tumor, and must pass through the endothelium before reaching the bloodstream. Using a phase-field model we have shown that the elasticity mismatch between cells alone is sufficient to enhance the motility of thesofter cancer cell by means of bursty migration, in agreement with experiment. We will present further characterization of these behaviour, as well as new possible applications for this model.

  17. 75 FR 16719 - Agricultural Water Enhancement Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-02

    ... Commodity Credit Corporation Agricultural Water Enhancement Program AGENCY: Commodity Credit Corporation and... Agricultural Water Enhancement Program (AWEP) by amending section 1240I of the Food ] Security Act of 1985. The... technical assistance to agricultural producers to implement agricultural water enhancement activities...

  18. Transcriptional enhancer from milk protein genes

    SciTech Connect

    Casperson, Gerald F.; Schmidhauser, Christian T.; Bissell, Mina J.

    1999-01-01

    The invention relates to novel enhancer nucleotide sequences which stimulate transcription of heterologous DNA in cells in culture. The enhancers are derived from major milk protein genes by the process of deletion mapping and functional analysis. The invention also relates to expression vectors containing the novel enhancers.

  19. Transcriptional enhancer from milk protein genes

    SciTech Connect

    Casperson, G.F.; Schmidhauser, C.T.; Bissell, M.J.

    1999-12-21

    The invention relates to novel enhancer nucleotide sequences which stimulate transcription of heterologous DNA in cells in culture. The enhancers are derived from major milk protein genes by the process of deletion mapping and functional analysis. The invention also relates to expression vectors containing the novel enhancers.

  20. How Rapidly Does Enhanced Atrazine Degradation Develop

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Enhanced atrazine degradation has been documented in multiple fields in Colorado. A random survey of 70 fields in eastern Colorado showed that approximately 30% had enhanced atrazine degradation. However, the enhanced degradation is not necessarily long term. Twenty-five fields were tested in 200...

  1. Textual Enhancement of Input: Issues and Possibilities

    ERIC Educational Resources Information Center

    Han, ZhaoHong; Park, Eun Sung; Combs, Charles

    2008-01-01

    The input enhancement hypothesis proposed by Sharwood Smith (1991, 1993) has stimulated considerable research over the last 15 years. This article reviews the research on textual enhancement of input (TE), an area where the majority of input enhancement studies have aggregated. Methodological idiosyncrasies are the norm of this body of research.…

  2. 75 FR 18146 - Wetlands Reserve Enhancement Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-09

    ... Commodity Credit Corporation Wetlands Reserve Enhancement Program AGENCY: Commodity Credit Corporation and... available in fiscal year (FY) 2010 for the Wetlands Reserve Enhancement Program (WREP) throughout the United... enhance conservation outcomes on wetlands and adjacent lands. WREP targets and leverages resources...

  3. Enhanced performance PIR security sensors

    NASA Astrophysics Data System (ADS)

    Liddiard, Kevin C.

    2008-04-01

    Previous presentations to this forum have described a new technology initiative for low cost passive IR security sensors based on novel microbolometer FPA design, low cost optics and simplified packaging. The primary objective of this initiative is to develop a smart (intelligent) security sensor having a number of improvements over current pyroelectric PIR sensors, including imaging. However the same core technology can also be employed for an enhanced performance PIR sensor in the form of a upgrade retrofit for current sensors. This paper addresses the latter initiative. The enhanced performance PIR upgrade sensor has two significant advantages over current technology: extended detection range and ability to detect developing fire or equipment failure. It may thus be seen as an IR fire detection device complementing other sensors whilst having an extended range for human detection. It does not have the full capability of the smart security sensor, but has the advantages of simplicity and low cost short term development. Performance is described for a 4 x 4 FPA designed specifically for this application.

  4. Ge Nanocluster Enhanced Er Photoluminescence

    NASA Astrophysics Data System (ADS)

    Guzman, Julian; Chrzan, Daryl C.; Haller, Eugene E.

    2010-03-01

    We investigated the enhancement of the Er^3+ photoluminescence (PL) at 1540 nm by the incorporation of Ge nanoclusters into Er-doped silica using ion beams. We found that the Er^3+ PL enhancement is due to the presence of Ge and not to the radiation damage from the ion-implantation process. We determined that the Er^3+ PL depends on the Ge content, postgrowth annealing, and crystallinity of the Ge nanoclusters. Furthermore, we observed that the Er^3+ PL signal is maximized after annealing at 685 C for 1 h. This is the temperature at which Ge nanoclusters begin to crystallize. Transmission electron microscopy studies were conducted to determine the size distribution of the Ge nanoclusters. Moreover, extended X-ray absorption fine structure measurements performed at the Ge-K and Er-LIII edges revealed that there is negligible Ge-Er bonding. This suggests that Er is either fully oxidized or that it is not located in the Ge nanoclusters. Therefore, we believe that the energy transfer process from the Ge nanoclusters to the Er ions occurs through a non-optical resonant dipole transfer (F"orster ProcessfootnotetextT. F"orster, Discuss. Faraday Soc. 27, 7 (1959). similar to what has been proposed for the Si nanocrystal case.footnotetextM. Fujii, M. Yoshida, S. Hayashi, and K. Yamamoto, J. Appl. Phys. 84, 4525 (1998).

  5. Optical antenna enhanced spontaneous emission.

    PubMed

    Eggleston, Michael S; Messer, Kevin; Zhang, Liming; Yablonovitch, Eli; Wu, Ming C

    2015-02-10

    Atoms and molecules are too small to act as efficient antennas for their own emission wavelengths. By providing an external optical antenna, the balance can be shifted; spontaneous emission could become faster than stimulated emission, which is handicapped by practically achievable pump intensities. In our experiments, InGaAsP nanorods emitting at ∼ 200 THz optical frequency show a spontaneous emission intensity enhancement of 35 × corresponding to a spontaneous emission rate speedup ∼ 115 ×, for antenna gap spacing, d = 40 nm. Classical antenna theory predicts ∼ 2,500 × spontaneous emission speedup at d ∼ 10 nm, proportional to 1/d(2). Unfortunately, at d < 10 nm, antenna efficiency drops below 50%, owing to optical spreading resistance, exacerbated by the anomalous skin effect (electron surface collisions). Quantum dipole oscillations in the emitter excited state produce an optical ac equivalent circuit current, I(o) = qω|x(o)|/d, feeding the antenna-enhanced spontaneous emission, where q|x(o)| is the dipole matrix element. Despite the quantum-mechanical origin of the drive current, antenna theory makes no reference to the Purcell effect nor to local density of states models. Moreover, plasmonic effects are minor at 200 THz, producing only a small shift of antenna resonance frequency. PMID:25624503

  6. Enhancement of skeletal muscle regeneration.

    PubMed

    Bischoff, R; Heintz, C

    1994-09-01

    We have studied the effect of adding extra satellite cells or soluble factors from crushed muscle on regeneration of minced fragments from rat tibialis muscle. The muscle mince was wrapped in an artificial epimysium to prevent adhesions and cell immigration from adjacent muscles. Regeneration was quantitatively assessed by electrophoretic determination of the muscle-specific form of creatine kinase. Control minces exhibited three periods of change in creatine kinase activity during a 7-week regeneration period. Activity fell rapidly during the first week, then rose gradually from 1-3 weeks and increased more rapidly from 3-7 weeks. To augment the original complement of myogenic cells, satellite cells were isolated from the contralateral muscle, purified by density gradient centrifugation, and expanded in culture for 3 days before adding to the muscle mince. The added cells resulted in a 3-fold enhancement of creatine kinase activity throughout the regeneration period. Soluble muscle extract incorporated into a collagen matrix also stimulated regeneration when added to muscle mince. The extract accelerated the rate of creatine kinase increase during the 1-3 week period beyond that observed in the control or cell augmented mince, suggesting that factors in the extract may facilitate revascularization or reinnervation. The specific activity of creatine kinase was increased in regenerates augmented with both cells and extract, indicating that the effects enhance primarily myogenic processes. PMID:7803846

  7. RTU Comparison Calculator Enhancement Plan

    SciTech Connect

    Miller, James D.; Wang, Weimin; Katipamula, Srinivas

    2015-07-01

    Over the past two years, Department of Energy’s Building Technologies Office (BTO) has been investigating ways to increase the operating efficiency of the packaged rooftop units (RTUs) in the field. First, by issuing a challenge to the RTU manufactures to increase the integrated energy efficiency ratio (IEER) by 60% over the existing ASHRAE 90.1-2010 standard. Second, by evaluating the performance of an advanced RTU controller that reduces the energy consumption by over 40%. BTO has previously also funded development of a RTU comparison calculator (RTUCC). RTUCC is a web-based tool that provides the user a way to compare energy and cost savings for two units with different efficiencies. However, the RTUCC currently cannot compare savings associated with either the RTU Challenge unit or the advanced RTU controls retrofit. Therefore, BTO has asked PNNL to enhance the tool so building owners can compare energy and savings associated with this new class of products. This document provides the details of the enhancements that are required to support estimating energy savings from use of RTU challenge units or advanced controls on existing RTUs.

  8. Chromophore-enhanced bacterial photothermolysis

    NASA Astrophysics Data System (ADS)

    Huckleby, Jana K.; Morton, Rebecca J.; Bartels, Kenneth E.

    1999-06-01

    The use of chromophore dyes to enhance the bactericidal effect of laser energy was studied as a means to optimize laser treatment for the decontamination of wound. Using an in vitro study, various concentrations of indocyanine green (ICG), carbon black, and fluorescein were mixed with a suspension of bacteria and plated on tryptic soy agar. Plates were exposed to a laser beam of 10-15 watts for times ranging from 0 to 180 seconds, incubated overnight, and colony counts were performed. Bacteria not mixed with chromophore were used as controls. Six bacterial strains encompassing a range of bacterial types were used: Staphylococcus aureau, Streptococcus pyogenes, Escherichia coli, Pseudomonas aeruginosa, Bacillus cereus spore suspensions, and Clostridium perfringens. Laser treatment alone had no effect on any of the bacteria. Significant killing of gram-positive bacteria, including spores of Bacillus cereus, was observed only with the use of ICG and diode laser energy. No effect was observed using any of the chromophores on the gram-negative bacteria. The results of this study indicate that successful killing of gram-positive bacteria can be achieved using ICG combined with appropriate laser energy and wavelength. Efforts to enhance the susceptibility of gram-negative bacteria to photothermolysis by laser energy were unsuccessful.

  9. Psychopharmacological enhancement: a conceptual framework

    PubMed Central

    2012-01-01

    The availability of a range of new psychotropic agents raises the possibility that these will be used for enhancement purposes (smart pills, happy pills, and pep pills). The enhancement debate soon raises questions in philosophy of medicine and psychiatry (eg, what is a disorder?), and this debate in turn raises fundament questions in philosophy of language, science, and ethics. In this paper, a naturalistic conceptual framework is proposed for addressing these issues. This framework begins by contrasting classical and critical concepts of categories, and then puts forward an integrative position that is based on cognitive-affective research. This position can in turn be used to consider the debate between pharmacological Calvinism (which may adopt a moral metaphor of disorder) and psychotropic utopianism (which may emphasize a medical metaphor of disorder). I argue that psychiatric treatment of serious psychiatric disorders is justified, and that psychotropics are an acceptable kind of intervention. The use of psychotropics for sub-threshold phenomena requires a judicious weighing of the relevant facts (which are often sparse) and values. PMID:22244084

  10. Optical antenna enhanced spontaneous emission

    PubMed Central

    Eggleston, Michael S.; Messer, Kevin; Zhang, Liming; Yablonovitch, Eli; Wu, Ming C.

    2015-01-01

    Atoms and molecules are too small to act as efficient antennas for their own emission wavelengths. By providing an external optical antenna, the balance can be shifted; spontaneous emission could become faster than stimulated emission, which is handicapped by practically achievable pump intensities. In our experiments, InGaAsP nanorods emitting at ∼200 THz optical frequency show a spontaneous emission intensity enhancement of 35× corresponding to a spontaneous emission rate speedup ∼115×, for antenna gap spacing, d = 40 nm. Classical antenna theory predicts ∼2,500× spontaneous emission speedup at d ∼ 10 nm, proportional to 1/d2. Unfortunately, at d < 10 nm, antenna efficiency drops below 50%, owing to optical spreading resistance, exacerbated by the anomalous skin effect (electron surface collisions). Quantum dipole oscillations in the emitter excited state produce an optical ac equivalent circuit current, Io = qω|xo|/d, feeding the antenna-enhanced spontaneous emission, where q|xo| is the dipole matrix element. Despite the quantum-mechanical origin of the drive current, antenna theory makes no reference to the Purcell effect nor to local density of states models. Moreover, plasmonic effects are minor at 200 THz, producing only a small shift of antenna resonance frequency. PMID:25624503

  11. Resolution-enhanced Mapping Spectrometer

    NASA Technical Reports Server (NTRS)

    Kumer, J. B.; Aubrun, J. N.; Rosenberg, W. J.; Roche, A. E.

    1993-01-01

    A familiar mapping spectrometer implementation utilizes two dimensional detector arrays with spectral dispersion along one direction and spatial along the other. Spectral images are formed by spatially scanning across the scene (i.e., push-broom scanning). For imaging grating and prism spectrometers, the slit is perpendicular to the spatial scan direction. For spectrometers utilizing linearly variable focal-plane-mounted filters the spatial scan direction is perpendicular to the direction of spectral variation. These spectrometers share the common limitation that the number of spectral resolution elements is given by the number of pixels along the spectral (or dispersive) direction. Resolution enhancement by first passing the light input to the spectrometer through a scanned etalon or Michelson is discussed. Thus, while a detector element is scanned through a spatial resolution element of the scene, it is also temporally sampled. The analysis for all the pixels in the dispersive direction is addressed. Several specific examples are discussed. The alternate use of a Michelson for the same enhancement purpose is also discussed. Suitable for weight constrained deep space missions, hardware systems were developed including actuators, sensor, and electronics such that low-resolution etalons with performance required for implementation would weigh less than one pound.

  12. Enhanced autophagy ameliorates cardiac proteinopathy

    PubMed Central

    Bhuiyan, Md. Shenuarin; Pattison, J. Scott; Osinska, Hanna; James, Jeanne; Gulick, James; McLendon, Patrick M.; Hill, Joseph A.; Sadoshima, Junichi; Robbins, Jeffrey

    2013-01-01

    Basal autophagy is a crucial mechanism in cellular homeostasis, underlying both normal cellular recycling and the clearance of damaged or misfolded proteins, organelles and aggregates. We showed here that enhanced levels of autophagy induced by either autophagic gene overexpression or voluntary exercise ameliorated desmin-related cardiomyopathy (DRC). To increase levels of basal autophagy, we generated an inducible Tg mouse expressing autophagy-related 7 (Atg7), a critical and rate-limiting autophagy protein. Hearts from these mice had enhanced autophagy, but normal morphology and function. We crossed these mice with CryABR120G mice, a model of DRC in which autophagy is significantly attenuated in the heart, to test the functional significance of autophagy activation in a proteotoxic model of heart failure. Sustained Atg7-induced autophagy in the CryABR120G hearts decreased interstitial fibrosis, ameliorated ventricular dysfunction, decreased cardiac hypertrophy, reduced intracellular aggregates and prolonged survival. To determine whether different methods of autophagy upregulation have additive or even synergistic benefits, we subjected the autophagy-deficient CryABR120G mice and the Atg7-crossed CryABR120G mice to voluntary exercise, which also upregulates autophagy. The entire exercised Atg7-crossed CryABR120G cohort survived to 7 months. These findings suggest that activating autophagy may be a viable therapeutic strategy for improving cardiac performance under proteotoxic conditions. PMID:24177425

  13. Enhanced Video-Oculography System

    NASA Technical Reports Server (NTRS)

    Moore, Steven T.; MacDougall, Hamish G.

    2009-01-01

    A previously developed video-oculography system has been enhanced for use in measuring vestibulo-ocular reflexes of a human subject in a centrifuge, motor vehicle, or other setting. The system as previously developed included a lightweight digital video camera mounted on goggles. The left eye was illuminated by an infrared light-emitting diode via a dichroic mirror, and the camera captured images of the left eye in infrared light. To extract eye-movement data, the digitized video images were processed by software running in a laptop computer. Eye movements were calibrated by having the subject view a target pattern, fixed with respect to the subject s head, generated by a goggle-mounted laser with a diffraction grating. The system as enhanced includes a second camera for imaging the scene from the subject s perspective, and two inertial measurement units (IMUs) for measuring linear accelerations and rates of rotation for computing head movements. One IMU is mounted on the goggles, the other on the centrifuge or vehicle frame. All eye-movement and head-motion data are time-stamped. In addition, the subject s point of regard is superimposed on each scene image to enable analysis of patterns of gaze in real time.

  14. Defense mutualisms enhance plant diversification.

    PubMed

    Weber, Marjorie G; Agrawal, Anurag A

    2014-11-18

    The ability of plants to form mutualistic relationships with animal defenders has long been suspected to influence their evolutionary success, both by decreasing extinction risk and by increasing opportunity for speciation through an expanded realized niche. Nonetheless, the hypothesis that defense mutualisms consistently enhance plant diversification across lineages has not been well tested due to a lack of phenotypic and phylogenetic information. Using a global analysis, we show that the >100 vascular plant families in which species have evolved extrafloral nectaries (EFNs), sugar-secreting organs that recruit arthropod mutualists, have twofold higher diversification rates than families that lack species with EFNs. Zooming in on six distantly related plant clades, trait-dependent diversification models confirmed the tendency for lineages with EFNs to display increased rates of diversification. These results were consistent across methodological approaches. Inference using reversible-jump Markov chain Monte Carlo (MCMC) to model the placement and number of rate shifts revealed that high net diversification rates in EFN clades were driven by an increased number of positive rate shifts following EFN evolution compared with sister clades, suggesting that EFNs may be indirect facilitators of diversification. Our replicated analysis indicates that defense mutualisms put lineages on a path toward increased diversification rates within and between clades, and is concordant with the hypothesis that mutualistic interactions with animals can have an impact on deep macroevolutionary patterns and enhance plant diversity. PMID:25349406

  15. Defense mutualisms enhance plant diversification

    PubMed Central

    Weber, Marjorie G.; Agrawal, Anurag A.

    2014-01-01

    The ability of plants to form mutualistic relationships with animal defenders has long been suspected to influence their evolutionary success, both by decreasing extinction risk and by increasing opportunity for speciation through an expanded realized niche. Nonetheless, the hypothesis that defense mutualisms consistently enhance plant diversification across lineages has not been well tested due to a lack of phenotypic and phylogenetic information. Using a global analysis, we show that the >100 vascular plant families in which species have evolved extrafloral nectaries (EFNs), sugar-secreting organs that recruit arthropod mutualists, have twofold higher diversification rates than families that lack species with EFNs. Zooming in on six distantly related plant clades, trait-dependent diversification models confirmed the tendency for lineages with EFNs to display increased rates of diversification. These results were consistent across methodological approaches. Inference using reversible-jump Markov chain Monte Carlo (MCMC) to model the placement and number of rate shifts revealed that high net diversification rates in EFN clades were driven by an increased number of positive rate shifts following EFN evolution compared with sister clades, suggesting that EFNs may be indirect facilitators of diversification. Our replicated analysis indicates that defense mutualisms put lineages on a path toward increased diversification rates within and between clades, and is concordant with the hypothesis that mutualistic interactions with animals can have an impact on deep macroevolutionary patterns and enhance plant diversity. PMID:25349406

  16. Cavity-Enhanced Ultrafast Spectroscopy

    NASA Astrophysics Data System (ADS)

    Allison, Thomas

    2016-05-01

    Ultrafast optical spectroscopy methods, such as transient absorption spectroscopy and 2D-spectroscopy, are widely used across many disciplines. However, these techniques are typically restricted to optically thick samples, such as solids and liquid solutions. Using a frequency comb laser and optical cavities, we present a new technique for performing ultrafast optical spectroscopy with high sensitivity, enabling work in dilute gas-phase molecular beams. Resonantly enhancing the probe pulses, we demonstrate transient absorption measurements with a detection limit of ΔOD = 2 ×10-10 (1 ×10-9 /√{Hz}). Resonantly enhancing the pump pulses allows us to produce a high excitation fraction at high repetition-rate, so that signals can be recorded from samples with optical densities as low as OD 10-8 , or column densities < 1010 molecules/ cm2. To our knowledge, this represents a 5,000-fold improvement of the state-of-the-art. This work was supported by the National Science Foundation under Grant Number 1404296.

  17. Pharmacokinetic enhancers in HIV therapeutics.

    PubMed

    Larson, Kajal B; Wang, Kun; Delille, Cecile; Otofokun, Igho; Acosta, Edward P

    2014-10-01

    Maximal and durable viral load suppression is one of the most important goals of HIV therapy and is directly related to adequate drug exposure. Protease inhibitors (PIs), an important component of the antiretroviral armada, were historically associated with poor oral bioavailability and high pill burden. However, because the PIs are metabolized by cytochrome P450 (CYP) 3A enzymes, intentional inhibition of these enzymes leads to higher drug exposure, lower pill burden, and therefore simplified dosing schedules with this class of drug. This is the basis of pharmacokinetic enhancement. In HIV therapy, two pharmacokinetic enhancers or boosting agents are used: ritonavir and cobicistat. Both agents inhibit CYP3A4, with cobicistat being a more specific CYP inhibitor than ritonavir. Unlike ritonavir, cobicistat does not have antiretroviral activity. Cobicistat has been evaluated in clinical trials and was recently approved in the USA as a fixed-dose combination with the integrase inhibitor, elvitegravir and two nucleos(t)ide analogs. Additional studies are examining cobicistat in fixed-dose combinations with various PIs. In this review, we summarize current knowledge of these agents and clinically relevant drug regimens and ongoing trials. Studies with elvitegravir and the novel PI TMC319011 are also discussed. PMID:25164142

  18. Catalytically enhanced packed tower scrubbing

    SciTech Connect

    Stitt, E.H.; Taylor, F.J.; Kelly, K.

    1996-12-31

    An enhanced wet scrubbing process for the treatment of gas streams containing odours and low level VOC`s is presented. It comprises essentially a single scrubbing column and a fixed bed catalytic reactor through which the dilute alkaline bleach scrubbing liquor is recirculated. The process has significant cost advantages over conventional chemical scrubbing technology, and copes well with peaks in odour levels. Traditional bleach scrubbing, and the improvements in process chemistry and the flowsheet afforded by inclusion of the catalyst, are discussed. The catalyst enables many of the well known problems associated with bleach scrubbing to be overcome, and facilitates odour removal efficiencies of greater than 99% in a single column. Pilot plant data from trials on sewage treatment works are presented. These show clearly the ability of the catalytically enhanced process to achieve sulphide and odour removals in excess of 99% in the single column. Case studies of some of the existing commercial installations are given, indicating the wide range of applications, industries and scale of the installed units. Comparative data are presented, measured on a commercial unit for the conventional operation of a bleach scrubber, and with the retrofitted catalyst in use. These data show clearly the benefits of the catalytic process in terms of removal efficiencies; and hence by inference also in equipment size and costs. The catalytic process is also shown to achieve very high removal efficiencies of organo-sulphides in a single column. 8 refs., 3 figs., 10 tabs.

  19. Electrokinetic Microstrirring to Enhance Immunoassays

    NASA Astrophysics Data System (ADS)

    Feldman, Hope; Sigurdson, Marin; Meinhart, Carl

    2006-11-01

    Electrokinetic microstirring is used to improve the sensitivity of microfluidic heterogeneous immuno-sensors by enhancing the transport in diffusion-limited reactions. The AC electrokinetic force, Electrothermal Flow, is exploited to create a circular stirring fluid motion, thereby providing more binding opportunities between suspended and wall-immobilized molecules. This process can significantly reduce test times, important for both field-portable biosensors and for lab-based assays. A 2-D numerical simulation model is used to predict the effect of electrothermal flow on a heterogeneous immunoassay resulting from an AC potential applied to two parallel electrodes. The binding is increased by a factor of 7 for an applied voltage of 10 Vrms. The effect was investigated experimentally using a high affinity biotin-streptavidin reaction. Microstirred reaction rates were compared with passive reactions. The measurements show on average an order of magnitude increase in binding between immobilized biotin and fluorescently-labeled streptavidin after 5 minutes. Therefore, this technique shows significant promise for reducing incubation time and enhancing the sensitivity of immunoassays.

  20. Enhancing poxvirus vectors vaccine immunogenicity

    PubMed Central

    García-Arriaza, Juan; Esteban, Mariano

    2014-01-01

    Attenuated recombinant poxvirus vectors expressing heterologous antigens from pathogens are currently at various stages in clinical trials with the aim to establish their efficacy. This is because these vectors have shown excellent safety profiles, significant immunogenicity against foreign expressed antigens and are able to induce protective immune responses. In view of the limited efficacy triggered by some poxvirus strains used in clinical trials (i.e, ALVAC in the RV144 phase III clinical trial for HIV), and of the restrictive replication capacity of the highly attenuated vectors like MVA and NYVAC, there is a consensus that further improvements of these vectors should be pursuit. In this review we considered several strategies that are currently being implemented, as well as new approaches, to improve the immunogenicity of the poxvirus vectors. This includes heterologous prime/boost protocols, use of co-stimulatory molecules, deletion of viral immunomodulatory genes still present in the poxvirus genome, enhancing virus promoter strength, enhancing vector replication capacity, optimizing expression of foreign heterologous sequences, and the combined use of adjuvants. An optimized poxvirus vector triggering long-lasting immunity with a high protective efficacy against a selective disease should be sought. PMID:25424927

  1. RTU Comparison Calculator Enhancement Plan

    SciTech Connect

    Miller, James D.; Wang, Weimin; Katipamula, Srinivas

    2014-03-31

    Over the past two years, Department of Energy’s Building Technologies Office (BTO) has been investigating ways to increase the operating efficiency of the packaged rooftop units (RTUs) in the field. First, by issuing a challenge to the RTU manufactures to increase the integrated energy efficiency ratio (IEER) by 60% over the existing ASHRAE 90.1-2010 standard. Second, by evaluating the performance of an advanced RTU controller that reduces the energy consumption by over 40%. BTO has previously also funded development of a RTU comparison calculator (RTUCC). RTUCC is a web-based tool that provides the user a way to compare energy and cost savings for two units with different efficiencies. However, the RTUCC currently cannot compare savings associated with either the RTU Challenge unit or the advanced RTU controls retrofit. Therefore, BTO has asked PNNL to enhance the tool so building owners can compare energy and savings associated with this new class of products. This document provides the details of the enhancements that are required to support estimating energy savings from use of RTU challenge units or advanced controls on existing RTUs.

  2. Potential MCNP enhancements for NCT

    SciTech Connect

    Estes, G.P.; Taylor, W.M.

    1992-01-01

    MCNP a Monte Carlo radiation transport code, is currently widely used in the medical community for a variety of purposes including treatment planning, diagnostics, beam design, tomographic studies, and radiation protection. This is particularly true in the Neutron Capture Therapy (NCT) community. The current widespread medical use of MCNP after its general public distribution in about 1980 attests to the code's general versatility and usefulness, particularly since its development to date has not been influenced by medical applications. This paper discusses enhancements to MCNP that could be implemented at Los Alamos for the benefit of the NCT community. These enhancements generally fall into two categories, namely those that have already been developed to some extent but are not yet publicly available, and those that seem both needed based on our current understanding of NCT goals, and achievable based on our working knowledge of the MCNP code. MCNP is a general, coupled neutron/photon/electron Monte Carlo code developed and maintained by the Radiation Transport Group at Los Alamos. It has been used extensively for radiation shielding studies, reactor analysis, detector design, physics experiment interpretation, oil and gas well logging, radiation protection studies, accelerator design, etc. over the years. MCNP is a three-dimensional geometry, continuous energy physics code capable of modeling complex geometries, specifying material regions such as organs by the intersections of analytical surfaces.

  3. Potential MCNP enhancements for NCT

    SciTech Connect

    Estes, G.P.; Taylor, W.M.

    1992-12-01

    MCNP a Monte Carlo radiation transport code, is currently widely used in the medical community for a variety of purposes including treatment planning, diagnostics, beam design, tomographic studies, and radiation protection. This is particularly true in the Neutron Capture Therapy (NCT) community. The current widespread medical use of MCNP after its general public distribution in about 1980 attests to the code`s general versatility and usefulness, particularly since its development to date has not been influenced by medical applications. This paper discusses enhancements to MCNP that could be implemented at Los Alamos for the benefit of the NCT community. These enhancements generally fall into two categories, namely those that have already been developed to some extent but are not yet publicly available, and those that seem both needed based on our current understanding of NCT goals, and achievable based on our working knowledge of the MCNP code. MCNP is a general, coupled neutron/photon/electron Monte Carlo code developed and maintained by the Radiation Transport Group at Los Alamos. It has been used extensively for radiation shielding studies, reactor analysis, detector design, physics experiment interpretation, oil and gas well logging, radiation protection studies, accelerator design, etc. over the years. MCNP is a three-dimensional geometry, continuous energy physics code capable of modeling complex geometries, specifying material regions such as organs by the intersections of analytical surfaces.

  4. Enhanced modeling features within TREETOPS

    NASA Technical Reports Server (NTRS)

    Vandervoort, R. J.; Kumar, Manoj N.

    1989-01-01

    The original motivation for TREETOPS was to build a generic multi-body simulation and remove the burden of writing multi-body equations from the engineers. The motivation of the enhancement was twofold: (1) to extend the menu of built-in features (sensors, actuators, constraints, etc.) that did not require user code; and (2) to extend the control system design capabilities by linking with other government funded software (NASTRAN and MATLAB). These enhancements also serve to bridge the gap between structures and control groups. It is common on large space programs for the structures groups to build hi-fidelity models of the structure using NASTRAN and for the controls group to build lower order models because they lack the tools to incorporate the former into their analysis. Now the controls engineers can accept the hi-fidelity NASTRAN models into TREETOPS, add sensors and actuators, perform model reduction and couple the result directly into MATLAB to perform their design. The controller can then be imported directly into TREETOPS for non-linear, time-history simulation.

  5. Plasmonic enhancement of ultraviolet fluorescence

    NASA Astrophysics Data System (ADS)

    Jiao, Xiaojin

    Plasmonics relates to the interaction between electromagnetic radiation and conduction electrons at metallic interfaces or in metallic nanostructures. Surface plasmons are collective electron oscillations at a metal surface, which can be manipulated by shape, texture and material composition. Plasmonic applications cover a broad spectrum from visible to near infrared, including biosensing, nanolithography, spectroscopy, optoelectronics, photovoltaics and so on. However, there remains a gap in this activity in the ultraviolet (UV, < 400 nm), where significant opportunity exists for both fundamental and application research. Motivating factors in the study of UV Plasmonics are the direct access to biomolecular resonances and native fluorescence, resonant Raman scattering interactions, and the potential for exerting control over photochemical reactions. This dissertation aims to fill in the gap of Plasmonics in the UV with efforts of design, fabrication and characterization of aluminium (Al) and magnesium (Mg) nanostructures for the application of label-free bimolecular detection via native UV fluorescence. The first contribution of this dissertation addresses the design of Al nanostructures in the context of UV fluorescence enhancement. A design method that combines analytical analysis with numerical simulation has been developed. Performance of three canonical plasmonic structures---the dipole antenna, bullseye nanoaperture and nanoaperture array---has been compared. The optimal geometrical parameters have been determined. A novel design of a compound bullseye structure has been proposed and numerically analyzed for the purpose of compensating for the large Stokes shift typical of UV fluorescence. Second, UV lifetime modification of diffusing molecules by Al nanoapertures has been experimentally demonstrated for the first time. Lifetime reductions of ~3.5x have been observed for the high quantum yield (QY) laser dye p-terphenyl in a 60 nm diameter aperture with 50

  6. Approach to intensely enhancing neck nodes

    PubMed Central

    Karandikar, Amit; Gummalla, Krishna Mohan; Loke, Siu Cheng; Goh, Julian; Tan, Tiong Yong

    2016-01-01

    Cervical node evaluation is one of the most common problems encountered by a radiologist. Here, we present a pictorial review of intensely enhancing neck nodes. While enhancement in a cervical node is a common radiologic finding on contrast-enhanced computed tomography scan, only few conditions cause intense enhancement in cervical nodes. We discuss the common causes of intensely enhancing neck nodes along with pertinent radiologic features and key differentiating points that aid radiologists in reaching a diagnosis. In addition, we discuss certain potential non-nodal mimics, which need to be excluded. PMID:26782154

  7. Diet effects on glucose absorption in the small intestine of neonatal calves: importance of intestinal mucosal growth, lactase activity, and glucose transporters.

    PubMed

    Steinhoff-Wagner, Julia; Zitnan, Rudolf; Schönhusen, Ulrike; Pfannkuche, Helga; Hudakova, Monika; Metges, Cornelia C; Hammon, Harald M

    2014-10-01

    Colostrum (C) feeding in neonatal calves improves glucose status and stimulates intestinal absorptive capacity, leading to greater glucose absorption when compared with milk-based formula feeding. In this study, diet effects on gut growth, lactase activity, and glucose transporters were investigated in several gut segments of the small intestine. Fourteen male German Holstein calves received either C of milkings 1, 3, and 5 (d 1, 2, and 3 in milk) or respective formulas (F) twice daily from d 1 to d 3 after birth. Nutrient content, and especially lactose content, of C and respective F were the same. On d 4, calves were fed C of milking 5 or respective F and calves were slaughtered 2h after feeding. Tissue samples from duodenum and proximal, mid-, and distal jejunum were taken to measure villus size and crypt depth, mucosa and brush border membrane vesicles (BBMV) were taken to determine protein content, and mRNA expression and activity of lactase and mRNA expression of sodium-dependent glucose co-transporter-1 (SGLT1) and facilitative glucose transporter (GLUT2) were determined from mucosal tissue. Additionally, protein expression of SGLT1 in BBMV and GLUT2 in crude mucosal membranes and BBMV were determined, as well as immunochemically localized GLUT2 in the intestinal mucosa. Villus circumference, area, and height were greater, whereas crypt depth was smaller in C than in F. Lactase activity tended to be greater in C than in F. Protein expression of SGLT1 was greater in F than in C. Parameters of villus size, lactase activity, SGLT1 protein expression, as well as apical and basolateral GLUT2 localization in the enterocytes differed among gut segments. In conclusion, C feeding, when compared with F feeding, enhances glucose absorption in neonatal calves primarily by stimulating mucosal growth and increasing absorptive capacity in the small intestine, but not by stimulating abundance of intestinal glucose transporters. PMID:25108868

  8. Microphthalmia transcription factor regulates pancreatic β-cell function.

    PubMed

    Mazur, Magdalena A; Winkler, Marcus; Ganic, Elvira; Colberg, Jesper K; Johansson, Jenny K; Bennet, Hedvig; Fex, Malin; Nuber, Ulrike A; Artner, Isabella

    2013-08-01

    Precise regulation of β-cell function is crucial for maintaining blood glucose homeostasis. Pax6 is an essential regulator of β-cell-specific factors like insulin and Glut2. Studies in the developing eye suggest that Pax6 interacts with Mitf to regulate pigment cell differentiation. Here, we show that Mitf, like Pax6, is expressed in all pancreatic endocrine cells during mouse postnatal development and in the adult islet. A Mitf loss-of-function mutation results in improved glucose tolerance and enhanced insulin secretion but no increase in β-cell mass in adult mice. Mutant β-cells secrete more insulin in response to glucose than wild-type cells, suggesting that Mitf is involved in regulating β-cell function. In fact, the transcription of genes critical for maintaining glucose homeostasis (insulin and Glut2) and β-cell formation and function (Pax4 and Pax6) is significantly upregulated in Mitf mutant islets. The increased Pax6 expression may cause the improved β-cell function observed in Mitf mutant animals, as it activates insulin and Glut2 transcription. Chromatin immunoprecipitation analysis shows that Mitf binds to Pax4 and Pax6 regulatory regions, suggesting that Mitf represses their transcription in wild-type β-cells. We demonstrate that Mitf directly regulates Pax6 transcription and controls β-cell function. PMID:23610061

  9. Microphthalmia Transcription Factor Regulates Pancreatic β-Cell Function

    PubMed Central

    Mazur, Magdalena A.; Winkler, Marcus; Ganić, Elvira; Colberg, Jesper K.; Johansson, Jenny K.; Bennet, Hedvig; Fex, Malin; Nuber, Ulrike A.; Artner, Isabella

    2013-01-01

    Precise regulation of β-cell function is crucial for maintaining blood glucose homeostasis. Pax6 is an essential regulator of β-cell–specific factors like insulin and Glut2. Studies in the developing eye suggest that Pax6 interacts with Mitf to regulate pigment cell differentiation. Here, we show that Mitf, like Pax6, is expressed in all pancreatic endocrine cells during mouse postnatal development and in the adult islet. A Mitf loss-of-function mutation results in improved glucose tolerance and enhanced insulin secretion but no increase in β-cell mass in adult mice. Mutant β-cells secrete more insulin in response to glucose than wild-type cells, suggesting that Mitf is involved in regulating β-cell function. In fact, the transcription of genes critical for maintaining glucose homeostasis (insulin and Glut2) and β-cell formation and function (Pax4 and Pax6) is significantly upregulated in Mitf mutant islets. The increased Pax6 expression may cause the improved β-cell function observed in Mitf mutant animals, as it activates insulin and Glut2 transcription. Chromatin immunoprecipitation analysis shows that Mitf binds to Pax4 and Pax6 regulatory regions, suggesting that Mitf represses their transcription in wild-type β-cells. We demonstrate that Mitf directly regulates Pax6 transcription and controls β-cell function. PMID:23610061

  10. Fluorescent penetration enhancers for transdermal applications.

    PubMed

    Seto, Jennifer E; Polat, Baris E; VanVeller, Brett; Lopez, Renata F V; Langer, Robert; Blankschtein, Daniel

    2012-02-28

    Chemical penetration enhancers are often used to enhance transdermal drug delivery. However, the fundamental mechanisms that govern the interactions between penetration enhancers and skin are not fully understood. Therefore, the goal of this work was to identify naturally fluorescent penetration enhancers (FPEs) in order to utilize well-established fluorescence techniques to directly study the behavior of FPEs within skin. In this study, 12 fluorescent molecules with amphiphilic characteristics were evaluated as skin penetration enhancers. Eight of the molecules exhibited significant activity as skin penetration enhancers, determined using skin current enhancement ratios. In addition, to illustrate the novel, direct, and non-invasive visualization of the behavior of FPEs within skin, three case studies involving the use of two-photon fluorescence microscopy (TPM) are presented, including visualizing glycerol-mitigated and ultrasound-enhanced FPE skin penetration. Previous TPM studies have indirectly visualized the effect of penetration enhancers on the skin by using a fluorescent dye to probe the transdermal pathways of the enhancer. These effects can now be directly visualized and investigated using FPEs. Finally, future studies are proposed for generating FPE design principles. The combination of FPEs with fluorescence techniques represents a useful novel approach for obtaining physical insights on the behavior of penetration enhancers within the skin. PMID:22062691

  11. Loudness enhancement and decrement in four paradigms

    NASA Technical Reports Server (NTRS)

    Elmasian, R.; Galambos, R.; Bernheim, A., Jr.

    1980-01-01

    When one tone burst (the conditioner) preceeds another (the target) by 100 ms, target loudness is enhanced if the conditioner is more intense and decreased if it is less intense. We show here that similar loudness enhancements and decrements occur when the conditioner follows the target. In all instances, monaural loudness enhancements (in which the conditioner and target are delivered to the same ear) are greater than the dichotic enhancements (in which the conditioner is presented contralaterally), but the decrements, which are smaller than the enhancements, are similar in magnitude. Loudness enhancements and decrements are similar to sequential loudness effects and central tendency effects; the major difference is the relatively very large increases in loudness obtainable in loudness enhancement experiments. We outline a mechanism to account for these loudness phenomena and suggest that this mechanism is responsible for similar perceptual effects that occur in other stimulus dimensions and modalities.

  12. NORMAL HUMAN VARIATION: REFOCUSSING THE ENHANCEMENT DEBATE

    PubMed Central

    Kahane, Guy; Savulescu, Julian

    2015-01-01

    This article draws attention to several common mistakes in thinking about biomedical enhancement, mistakes that are made even by some supporters of enhancement. We illustrate these mistakes by examining objections that John Harris has recently raised against the use of pharmacological interventions to directly modulate moral decision-making. We then apply these lessons to other influential figures in the debate about enhancement. One upshot of our argument is that many considerations presented as powerful objections to enhancement are really strong considerations in favour of biomedical enhancement, just in a different direction. Another upshot is that it is unfortunate that much of the current debate focuses on interventions that will radically transform normal human capacities. Such interventions are unlikely to be available in the near future, and may not even be feasible. But our argument shows that the enhancement project can still have a radical impact on human life even if biomedical enhancement operated entirely within the normal human range. PMID:23906367

  13. Normal human variation: refocussing the enhancement debate.

    PubMed

    Kahane, Guy; Savulescu, Julian

    2015-02-01

    This article draws attention to several common mistakes in thinking about biomedical enhancement, mistakes that are made even by some supporters of enhancement. We illustrate these mistakes by examining objections that John Harris has recently raised against the use of pharmacological interventions to directly modulate moral decision-making. We then apply these lessons to other influential figures in the debate about enhancement. One upshot of our argument is that many considerations presented as powerful objections to enhancement are really strong considerations in favour of biomedical enhancement, just in a different direction. Another upshot is that it is unfortunate that much of the current debate focuses on interventions that will radically transform normal human capacities. Such interventions are unlikely to be available in the near future, and may not even be feasible. But our argument shows that the enhancement project can still have a radical impact on human life even if biomedical enhancement operated entirely within the normal human range. PMID:23906367

  14. Quantum-enhanced absorption refrigerators

    PubMed Central

    Correa, Luis A.; Palao, José P.; Alonso, Daniel; Adesso, Gerardo

    2014-01-01

    Thermodynamics is a branch of science blessed by an unparalleled combination of generality of scope and formal simplicity. Based on few natural assumptions together with the four laws, it sets the boundaries between possible and impossible in macroscopic aggregates of matter. This triggered groundbreaking achievements in physics, chemistry and engineering over the last two centuries. Close analogues of those fundamental laws are now being established at the level of individual quantum systems, thus placing limits on the operation of quantum-mechanical devices. Here we study quantum absorption refrigerators, which are driven by heat rather than external work. We establish thermodynamic performance bounds for these machines and investigate their quantum origin. We also show how those bounds may be pushed beyond what is classically achievable, by suitably tailoring the environmental fluctuations via quantum reservoir engineering techniques. Such superefficient quantum-enhanced cooling realises a promising step towards the technological exploitation of autonomous quantum refrigerators. PMID:24492860

  15. Mutual enhancement of diverse terminologies

    PubMed Central

    Hardiker, Nicholas R.; Casey, Anne; Coenen, Amy; Konicek, Debra

    2006-01-01

    The purpose of this study was to map the North American Nursing Diagnosis Association (NANDA) nursing diagnoses to the International Classification for Nursing Practice Version 1.0 (ICNP®) and to compare the resulting representations and relationships to those within SNOMED® Clinical Terms (CT). Independent reviewers reached agreement on 25 (i.e. 64%) of the 39 parent-child relationships identified via the mappings between NANDA entities. Other parent-child relationships were more questionable and are in need of further discussion. This work does not seek to promote one terminology over any other. Rather, this collaborative effort has the potential to mutually enhance all three terminologies involved in the study: ICNP®, SNOMED® CT and NANDA. In doing so it provides an example of the type of collaborative effort that is needed to facilitate the development of tools to support interoperability at a global level. PMID:17238355

  16. Enhanced High Resolution RBS System

    SciTech Connect

    Pollock, Thomas J.; Hass, James A.; Klody, George M.

    2011-06-01

    Improvements in full spectrum resolution with the second NEC high resolution RBS system are summarized. Results for 50 A ring TiN/HfO films on Si yielding energy resolution on the order of 1 keV are also presented. Detector enhancements include improved pulse processing electronics, upgraded shielding for the MCP/RAE detector, and reduced noise generated from pumping. Energy resolution measurements on spectra front edge coupled with calculations using 0.4mStr solid angle show that beam energy spread at 400 KeV from the Pelletron registered accelerator is less than 100 eV. To improve user throughput, magnet control has been added to the automatic data collection. Depth profiles derived from experimental data are discussed. For the thin films profiled, depth resolutions were on the Angstrom level with the non-linear energy/channel conversions ranging from 100 to 200 eV.

  17. Simulator for enhanced ATAMM multiprocessing

    NASA Technical Reports Server (NTRS)

    Andrews, Asa M.; Jones, Robert L.; Hayes, Paul J.; Benz, Harry F.

    1991-01-01

    A simulator is introduced which follows the rules of the enhanced Algorithm to Architecture Mapping Model (ATAMM) multiprocessing strategy. ATAMM is a method for embedding an algorithm into a multiprocessing system in addition to providing system performance prediction capabilities. A discussion of the inner workings of the Architecture Design and Assessment System (ADAS) hosted simulator is introduced to illustrate how the simulator follows the ATAMM rule set. A sample 5-node algorithm graph is given as an example to illustrate: (1) entering of a graph into the simulator and how to run the graph using a graph entry tool; (2) how to analyze the data; and (3) a comparison of the simulation results with the predicted results from ATAMM.

  18. Fan Flutter Analysis Capability Enhanced

    NASA Technical Reports Server (NTRS)

    Bakhle, Milind A.; Srivastava, Rakesh; Stefko, George L.

    2001-01-01

    The trend in the design of advanced transonic fans for aircraft engines has been toward the use of complex high-aspect-ratio blade geometries with a larger number of blades and higher loading. In addition, integrally bladed disks or blisks are being considered in fan designs for their potential to reduce manufacturing costs, weight, and complexity by eliminating attachments. With such design trends, there is an increased possibility within the operating region of part-speed stall flutter (self-excited vibrations) that is exacerbated by the reduced structural damping of blisk fans. To verify the aeroelastic soundness of the design, the NASA Glenn Research Center is developing and validating an accurate aeroelastic prediction and analysis capability. Recently, this capability was enhanced significantly as described here.

  19. Enhanced High Resolution RBS System

    NASA Astrophysics Data System (ADS)

    Pollock, Thomas J.; Hass, James A.; Klody, George M.

    2011-06-01

    Improvements in full spectrum resolution with the second NEC high resolution RBS system are summarized. Results for 50 Å TiN/HfO films on Si yielding energy resolution on the order of 1 keV are also presented. Detector enhancements include improved pulse processing electronics, upgraded shielding for the MCP/RAE detector, and reduced noise generated from pumping. Energy resolution measurements on spectra front edge coupled with calculations using 0.4mStr solid angle show that beam energy spread at 400 KeV from the Pelletron® accelerator is less than 100 eV. To improve user throughput, magnet control has been added to the automatic data collection. Depth profiles derived from experimental data are discussed. For the thin films profiled, depth resolutions were on the Angstrom level with the non-linear energy/channel conversions ranging from 100 to 200 eV.

  20. Nanoplasmonics: Enhancement of optical radiation

    NASA Astrophysics Data System (ADS)

    Alzaim, Safa

    The way a fluorophore behaves in free space is very different from the way that it behaves in the presence of a metal nanosphere. This change is because the fluorophore, in its excited state, interacts with the free electrons in the metal. The charge density of the free electrons oscillate as surface plasmons, and when an electric field is applied, the surface plasmons couple to the field to produce surface plasmon polaritons. The resulting resonance modifies the optical properties of the fluorophore. The behaviors of nanoplasmonics systems derive from the interaction of light with conduction electrons, which means that understanding nanoplasmonics requires understanding the Drude Model and Maxwell's Equations. The Drude Model gives a basis for understanding free electron behavior, in order to investigate the dielectric function and electrodynamics in the context of a nanoplasmonic system. Thisstudy offers a mathematical model for the enhancement of the fluorescence in the presence of a silver nanosphere.

  1. Covariance-enhanced discriminant analysis

    PubMed Central

    XU, PEIRONG; ZHU, JI; ZHU, LIXING; LI, YI

    2016-01-01

    Summary Linear discriminant analysis has been widely used to characterize or separate multiple classes via linear combinations of features. However, the high dimensionality of features from modern biological experiments defies traditional discriminant analysis techniques. Possible interfeature correlations present additional challenges and are often underused in modelling. In this paper, by incorporating possible interfeature correlations, we propose a covariance-enhanced discriminant analysis method that simultaneously and consistently selects informative features and identifies the corresponding discriminable classes. Under mild regularity conditions, we show that the method can achieve consistent parameter estimation and model selection, and can attain an asymptotically optimal misclassification rate. Extensive simulations have verified the utility of the method, which we apply to a renal transplantation trial.

  2. Teacher Enhancement and Preparation Programs

    NASA Technical Reports Server (NTRS)

    1995-01-01

    These two programs provide opportunities for K-12 teachers of mathematics, science, and technology to spend two weeks at a NASA center learning about aeronautics and space. Participants are selected by peer review from a contracting agent that assists NASA in administering the program. Each teacher receives a stipend that covers the cost of travel, housing, meals, and graduate credit. NEWMAST provides for approximately 100 secondary teachers, and NEWTEST is a program designed to meet the needs of approximately 125 elementary teachers each summer. Teachers are provided with a wide variety of experiences including research laboratory observations, presentations, and 'shadowships'. Individual and team projects are used to enhance the participants knowledge of space and aeronautics and to motivate the teachers to incorporate the summer workshop activities into their classrooms.

  3. Shale Oil Value Enhancement Research

    SciTech Connect

    James W. Bunger

    2006-11-30

    Raw kerogen oil is rich in heteroatom-containing compounds. Heteroatoms, N, S & O, are undesirable as components of a refinery feedstock, but are the basis for product value in agrochemicals, pharmaceuticals, surfactants, solvents, polymers, and a host of industrial materials. An economically viable, technologically feasible process scheme was developed in this research that promises to enhance the economics of oil shale development, both in the US and elsewhere in the world, in particular Estonia. Products will compete in existing markets for products now manufactured by costly synthesis routes. A premium petroleum refinery feedstock is also produced. The technology is now ready for pilot plant engineering studies and is likely to play an important role in developing a US oil shale industry.

  4. New technology enhances compressor performance

    SciTech Connect

    Not Available

    1992-03-01

    This paper reports on new technology using active magnetic bearings and dry gas seals for oil-free compressors, a modified crankshaft arrangement for high-pressure centrifugal compressors, and a grid valve for steam turbines which enhances compressor reliability and longevity. Thermodyn, a division of Framatome, reports it has incorporated this new compressor technology in high-performance facilities equipped with advanced computers to improve its compressor and turbine design and manufacturing. Powerful computer programs associated with CAD were used for accurate geometric design of complex-shape parts which were then produced on N-C machine tools. These precise geometric designs have benefited centrifugal compressors with high or low volume flow, high molecular weight or high flow pressure.

  5. Enhancing AFLOW Visualization using Jmol

    NASA Astrophysics Data System (ADS)

    Lanasa, Jacob; New, Elizabeth; Stefek, Patrik; Honaker, Brigette; Hanson, Robert; Aflow Collaboration

    The AFLOW library is a database of theoretical solid-state structures and calculated properties created using high-throughput ab initio calculations. Jmol is a Java-based program capable of visualizing and analyzing complex molecular structures and energy landscapes. In collaboration with the AFLOW consortium, our goal is the enhancement of the AFLOWLIB database through the extension of Jmol's capabilities in the area of materials science. Modifications made to Jmol include the ability to read and visualize AFLOW binary alloy data files, the ability to extract from these files information using Jmol scripting macros that can be utilized in the creation of interactive web-based convex hull graphs, the capability to identify and classify local atomic environments by symmetry, and the ability to search one or more related crystal structures for atomic environments using a novel extension of inorganic polyhedron-based SMILES strings

  6. Enhancing autonomy in paid surrogacy.

    PubMed

    Damelio, Jennifer; Sorensen, Kelly

    2008-06-01

    The gestational surrogate--and her economic and educational vulnerability in particular--is the focus of many of the most persistent worries about paid surrogacy. Those who employ her, and those who broker and organize her services, usually have an advantage over her in resources and information. That asymmetry exposes her to the possibility of exploitation and abuse. Accordingly, some argue for banning paid surrogacy. Others defend legal permission on grounds of surrogate autonomy, but often retain concerns about the surrogate. In response to the dilemma of a ban versus bald permission, we propose a 'soft law' approach: states should require several hours of education of surrogates--education aimed at informing and enhancing surrogate autonomy. PMID:18447862

  7. TOPICAL REVIEW: Surface enhanced fluorescence

    NASA Astrophysics Data System (ADS)

    Fort, Emmanuel; Grésillon, Samuel

    2008-01-01

    Fluorescence is widely used in optical devices, microscopy imaging, biology, medical research and diagnosis. Improving fluorescence sensitivity, all the way to the limit of single-molecular detection needed in many applications, remains a great challenge. The technique of surface enhanced fluorescence (SEF) is based upon the design of surfaces in the vicinity of the emitter. SEF yields an overall improvement in the fluorescence detection efficiency through modification and control of the local electromagnetic environment of the emitter. Near-field coupling between the emitter and surface modes plays a crucial role in SEF. In particular, plasmonic surfaces with localized and propagating surface plasmons are efficient SEF substrates. Recent progress in tailoring surfaces at the nanometre scale extends greatly the realm of SEF applications. This review focuses on the recent advances in the different mechanisms involved in SEF, in each case highlighting the most relevant applications.

  8. Enhancing the US Power Infrastructure

    SciTech Connect

    Charles Alexander

    2010-05-31

    The primary motivation for this set of research activities was to develop a foundation in several aspects of power in order to position Cleveland State University to lead a multiuniversity effort to secure funding for enhanced power system projects and to be able to eventually secure a NASA Space Power Systems Center status through the competitive bidding process. This was accomplished by focusing on these major project areas, (1) the design of the next generation nuclear-electric power generation system, (2) the design of a distributed, fault-tolerant, and modular power system, and (3) the development of the dynamics and control of active magnetic bearings for flywheel energy storage without using conventional sensors.

  9. Strategies to Enhance Physician Engagement.

    PubMed

    Rosenstein, Alan H

    2015-01-01

    Healthcare reform and other externally driven healthcare initiatives have introduced a number of new healthcare requirements that are restructuring the way we provide healthcare services. With a growing focus on health plan efficiency and accountability for value-based performance metrics extending across the full spectrum of care, healthcare organizations are looking to develop new models of care to meet the needs of today's healthcare environment. Physician alignment and engagement are keys to success. But many physicians feel threatened, overwhelmed, and frustrated with the changes, and it's beginning to take its toll on physician attitudes and perspectives about care. Enhancing physician engagement requires a multistep process that includes making an effort to better understand their world; encouraging opportunities for input and participation in care redesign; providing education, training, guidance, and support; and making the effort to recognize and thank them for what they do. PMID:26665482

  10. Quantum-enhanced absorption refrigerators

    NASA Astrophysics Data System (ADS)

    Correa, Luis A.; Palao, José P.; Alonso, Daniel; Adesso, Gerardo

    2014-02-01

    Thermodynamics is a branch of science blessed by an unparalleled combination of generality of scope and formal simplicity. Based on few natural assumptions together with the four laws, it sets the boundaries between possible and impossible in macroscopic aggregates of matter. This triggered groundbreaking achievements in physics, chemistry and engineering over the last two centuries. Close analogues of those fundamental laws are now being established at the level of individual quantum systems, thus placing limits on the operation of quantum-mechanical devices. Here we study quantum absorption refrigerators, which are driven by heat rather than external work. We establish thermodynamic performance bounds for these machines and investigate their quantum origin. We also show how those bounds may be pushed beyond what is classically achievable, by suitably tailoring the environmental fluctuations via quantum reservoir engineering techniques. Such superefficient quantum-enhanced cooling realises a promising step towards the technological exploitation of autonomous quantum refrigerators.

  11. Microbial enhancement of oil recovery

    SciTech Connect

    Finnerty, W.R.; Singer, M.E.

    1983-03-01

    The purpose of this article is to present an overview of a supplementary biotechnology that will potentially aid in obtaining greater oil production and processing capabilities. This supplementary technology involves the application of microbiological processes to specific and well-defined problems in enhanced oil recovery (EOR). The discussion outlines scenarios for various microbiological processes that have been identified as promising areas for research and development, many of which are currently being addressed within the petroleum industry and by the Department of Energy. Microorganisms and microbial products can be used to recover oil from reservoirs. To be successful, the complexity of oil and the physical constraints in the reservoir must be taken into account. The three general approaches are: stimulation of the endogenous microbial population; injection of microorganisms with proven ability to perform well in situ; and the use of microbial products, such as xanthan gum, produced by Xanthomonas campestris.

  12. Temporal resolution enhancement from motion

    NASA Astrophysics Data System (ADS)

    Rollason, M. P.; Strens, M. J. A.; Gardner, A. P.

    2008-10-01

    We describe progress in the second year of the EMRS DTC TEP theme project entitled "Temporal Resolution Enhancement from Motion". The aim is to develop algorithms that combine evidence over time from a sequence of images in order to improve spatial resolution and reduce unwanted artefacts. A C++ implementation of an algorithm was developed in year one 1. Work in year two has improved the efficiency and extended the applicability of the algorithm. New schemes for information update and scene matching have substantially reduced the processing time and enabled application of the technique to imagery with more complicated viewing geometries. The new technique is demonstrated using airborne infra-red imagery datasets from a Wescam MX series turret on a helicopter.

  13. Stall-Departure-Resistance Enhancer

    NASA Technical Reports Server (NTRS)

    Ross, Holly M.; Johnson, Joseph L., Jr.; Yip, Long P.; Stough, H. Paul, III

    1992-01-01

    Stall-departure-resistance enhancer imposes lesser drag penalty than nortex generators of older types. Increases lift by as much as 30 percent at angles of attack otherwise in poststall region. Device is flat plate wedge with 60 degree sweep angle and attached so it protrudes from leading edge of wing. Tip is sharp point, and edges made thin and sharp to induce good vortical flow. Applications include those intended to increase safety for broad range of aircraft, including trainers, fighters, general-aviation aircraft, and commercial transport aircraft. Nonaerospace applications where flow stall is problem under certain conditions, such as in control of separation in flow diffusers. Other applications in fluid machinery and fluid flow.

  14. Surfactant-enhanced aquifier remediation

    SciTech Connect

    Fountain, J.C.

    1996-12-31

    Surfactants can be used to rapidly remove NAPL from contaminated aquifers. They are effective for virtually any organic contaminant. Use in LNAPL contaminated sites requires adequate hydraulic conductivity and control of flow using either hydraulic or physical methods. The presence of DNAPL requires consideration of vertical mobility; a competent confining layer (aquitard) is required if additional aquifers are present at greater depths. Surfactant processes, whether based upon mobilization or solubilization, can be effective at mass removal, but cannot be expected to provide resortation to drinking water standards. The fraction of mass removal, and the cost of remediation using surfactants are dependent upon a sites hydrogeology. Both minimization of cost and maximization of NAPL removal requires detailed characterization of sites contaminant distribution and hydrogeology. Assessment of the feasibility of surfactant-enhanced remediation is dependent upon a detailed site characterization.

  15. Quantum-enhanced absorption refrigerators.

    PubMed

    Correa, Luis A; Palao, José P; Alonso, Daniel; Adesso, Gerardo

    2014-01-01

    Thermodynamics is a branch of science blessed by an unparalleled combination of generality of scope and formal simplicity. Based on few natural assumptions together with the four laws, it sets the boundaries between possible and impossible in macroscopic aggregates of matter. This triggered groundbreaking achievements in physics, chemistry and engineering over the last two centuries. Close analogues of those fundamental laws are now being established at the level of individual quantum systems, thus placing limits on the operation of quantum-mechanical devices. Here we study quantum absorption refrigerators, which are driven by heat rather than external work. We establish thermodynamic performance bounds for these machines and investigate their quantum origin. We also show how those bounds may be pushed beyond what is classically achievable, by suitably tailoring the environmental fluctuations via quantum reservoir engineering techniques. Such superefficient quantum-enhanced cooling realises a promising step towards the technological exploitation of autonomous quantum refrigerators. PMID:24492860

  16. Enhanced NIF neutron activation diagnostics

    SciTech Connect

    Yeamans, C. B.; Bleuel, D. L.; Bernstein, L. A.

    2012-10-15

    The NIF neutron activation diagnostic suite relies on removable activation samples, leading to operational inefficiencies and a fundamental lower limit on the half-life of the activated product that can be observed. A neutron diagnostic system measuring activation of permanently installed samples could remove these limitations and significantly enhance overall neutron diagnostic capabilities. The physics and engineering aspects of two proposed systems are considered: one measuring the {sup 89}Zr/{sup 89m}Zr isomer ratio in the existing Zr activation medium and the other using potassium zirconate as the activation medium. Both proposed systems could improve the signal-to-noise ratio of the current system by at least a factor of 5 and would allow independent measurement of fusion core velocity and fuel areal density.

  17. Does groundwater enhance evaporative cooling?

    NASA Astrophysics Data System (ADS)

    Rouholahnejad, E.

    2015-12-01

    Evaporation is a key process in land-climate interactions, not only because it directly regulates the hydrological cycle, but also because it contributes to the Earth's energy balance. Due to its feedbacks on large-scale water processes and its impact on the dynamics of the atmosphere, it has been considered as a driver of droughts and heatwaves1-3. While evaporation from ocean surfaces is likely to increase with rising temperatures, it is unclear whether evapotranspiration from land surfaces could similarly increase, due to possible limitations imposed by soil moisture and vegetation physiology4. Observations suggest that groundwater (hereafter GW) has an important role in hydrological budgets and soil moisture variability in many regions, supplying moisture for evapotranspiration during dry seasons5, 6. Although modeling studies suggest that GW is often close enough to the surface to interact with the atmosphere7, 8, the soil water storage is often underestimated by land surface models. This is most likely due to neglecting the lateral movement of water from topographically higher altitudes to valley bottoms and its convergence close to the land surface, as well as the upward movement of water in the capillary fringe.The focus of this study is to understand where and when GW may significantly enhance the availability of soil water for evapotranspiration. We also quantified the potential contribution of GW to evapotranspiration in the areas where GW is a major supply. We used the global network of eddy covariance observations9 (FLUXNET) along with global modeled GW depth10 and GLEAM ET model estimates11 to address the current gap in modelling ET due to neglecting GW supply. Having identified areas where GW is tightly coupled with the atmosphere through evaporation processes, the study provides the basis to examine the "air conditioning effect" of GW and test the idea if GW enhances evaporation to the extent that leads to a cooler temperatures and wetter climates.

  18. Polyethylene glycol enhanced protein refolding.

    PubMed

    Cleland, J L; Builder, S E; Swartz, J R; Winkler, M; Chang, J Y; Wang, D I

    1992-09-01

    Previous studies on the refolding of recombinant bovine carbonic anhydrase B (CAB) indicated that polyethylene glycol (PEG) significantly enhanced the recovery of active protein by reducing aggregation. To further test the ability of PEG to enhance refolding, three recombinant human proteins, deoxyribonuclease (rhDNAse), tissue plasminogen activator (rhtPA), and interferon-gamma (rhIFN-gamma) were refolded in the presence of PEG (3350 MW). rhDNAse produced from CHO cells was denatured in 7.2 M urea and refolded by rapid dilution to 4.0 M urea and 0.20 mg/ml protein. When a final PEG to rhDNAse molar ratio of 5 to 1 (0.1 milligram PEG, 3350 MW) was used in the dilution buffer, refolding was improved by 30% to yield complete recovery of active protein. Impure E. coli derived inclusion body preparations of rhDNAse were solubilized in 8 M urea and refolded by dilution to 4 M urea and 0.10 mg/ml protein. Refolding with a dilution buffer which yielded a final PEG to rhDNAse molar ratio of 10 to 1 (0.1 milligram PEG, 3350 MW) resulted in a three-fold increase in the recovery of active protein. When PEG was used in the dilution buffer, aggregation of rhDNAse did not occur during refolding in either case. rhtPA produced from CHO cells was denatured in 5 M guanidine hydrochloride (GuHCl) and refolded by rapid dilution to 0.10 M GuHCl and 0.20 mg/ml protein.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1368998

  19. Structure Enhancement Relationship of Chemical Penetration Enhancers in Drug Transport across the Stratum Corneum

    PubMed Central

    Chantasart, Doungdaw; Li, S. Kevin

    2012-01-01

    The stratum corneum is a major barrier of drug penetration across the skin in transdermal delivery. For effective transdermal drug delivery, skin penetration enhancers are used to overcome this barrier. In the past decades, a number of research studies were conducted to understand the mechanisms of skin penetration enhancers and to develop a structure enhancement relationship. Such understanding allows effective prediction of the effects of skin penetration enhancers, assists topical and transdermal formulation development, and avoids extensive enhancer screening in the transdermal delivery industry. In the past two decades, several hypotheses on chemical enhancer-induced penetration enhancement for transport across the skin lipoidal pathway have been examined based on a systematic approach. Particularly, a hypothesis that skin penetration enhancement is directly related to the concentration of the enhancers in the stratum corneum lipid domain was examined. A direct relationship between skin penetration enhancer potency (based on enhancer aqueous concentration in the diffusion cell chamber) and enhancer n-octanol-water partition coefficient was also established. The nature of the microenvironment of the enhancer site of action in the stratum corneum lipid domain was found to be mimicked by n-octanol. The present paper reviews the work related to these hypotheses and the relationships between skin penetration enhancement and enhancer concentration in the drug delivery media and stratum corneum lipids. PMID:24300181

  20. Functional characterization of SIM1-associated enhancers

    PubMed Central

    Kim, Mee J.; Oksenberg, Nir; Hoffmann, Thomas J.; Vaisse, Christian; Ahituv, Nadav

    2014-01-01

    Haploinsufficiency of the single-minded homology 1 (SIM1) gene in humans and mice leads to severe obesity, suggesting that altered expression of SIM1, by way of regulatory elements such as enhancers, could predispose individuals to obesity. Here, we identified transcriptional enhancers that could regulate SIM1, using comparative genomics coupled with zebrafish and mouse transgenic enhancer assays. Owing to the dual role of Sim1 in hypothalamic development and in adult energy homeostasis, the enhancer activity of these sequences was annotated from embryonic to adult age. Of the seventeen tested sequences, two SIM1 candidate enhancers (SCE2 and SCE8) were found to have brain-enhancer activity in zebrafish. Both SCE2 and SCE8 also exhibited embryonic brain-enhancer expression in mice, and time course analysis of SCE2 activity showed overlapping expression with Sim1 from embryonic to adult age, notably in the hypothalamus in adult mice. Using a deletion series, we identified the critical region in SCE2 that is needed for enhancer activity in the developing brain. Sequencing this region in obese and lean cohorts revealed a higher prevalence of single nucleotide polymorphisms (SNPs) that were unique to obese individuals, with one variant reducing developmental-enhancer activity in zebrafish. In summary, we have characterized two brain enhancers in the SIM1 locus and identified a set of obesity-specific SNPs within one of them, which may predispose individuals to obesity. PMID:24203700

  1. Acoustically Enhanced Electroplating Being Developed

    NASA Technical Reports Server (NTRS)

    Oeftering, Richard C.

    2002-01-01

    In cooperation with the NASA Glenn Research Center, Alchemitron Corp. is developing the Acoustically Enhanced Electroplating Process (AEEP), a new technique of employing nonlinear ultrasonics to enhance electroplating. The applications range from electroplating full-panel electronic circuit boards to electroplating microelectronics and microelectromechanical systems (MEMS) devices. In a conventional plating process, the surface area to be plated is separated from the nonplated areas by a temporary mask. The mask may take many forms, from a cured liquid coating to a simple tape. Generally, the mask is discarded when the plating is complete, creating a solid waste product that is often an environmental hazard. The labor and materials involved with the layout, fabrication, and tooling of masks is a primary source of recurring and nonrecurring production costs. The objective of this joint effort, therefore, is to reduce or eliminate the need for masks. AEEP improves selective plating processes by using directed beams of high-intensity acoustic waves to create nonlinear effects that alter the fluid dynamic and thermodynamic behavior of the plating process. It relies on two effects: acoustic streaming and acoustic heating. Acoustic streaming is observed when a high-intensity acoustic beam creates a liquid current within the beam. The liquid current can be directed as the beam is directed and, thus, users can move liquid around as desired without using pumps and nozzles. The current of the electroplating electrolyte, therefore, can be directed at distinct target areas where electroplating is desired. The current delivers fresh electrolyte to the target area while flushing away the spent electrolyte. This dramatically increases the plating rate in the target area. In addition, acoustic heating of both the liquid in the beam and the target surface increases the chemical reaction rate, which further increases the plating rate. The combined effects of acoustic streaming and

  2. Transcriptional Enhancers in Animal Development and Evolution

    PubMed Central

    Levine, Mike

    2014-01-01

    Regulatory DNAs serve as templates to bring weakly interacting transcription factors into close proximity so they can work synergistically to switch genes on and off in time and space. Most of these regulatory DNAs are enhancers that can work over long distances — a million base pairs or more in mammals — to control gene expression. Critical enhancers are sometimes even found within the introns of neighboring genes. This review summarizes well-defined examples of enhancers controlling key processes in animal development. Potential mechanisms of transcriptional synergy are discussed with regard to enhancer structure and contemporary ChIP-sequencing assays, whereby just a small fraction of the observed binding sites represent bona fide regulatory DNAs. Finally, there is a discussion of how enhancer evolution can produce novelty in animal morphology and of the prospects for reconstructing transitions in animal evolution by introducing derived enhancers in basal ancestors. PMID:20833320

  3. Comparative enhancing effects of electret with chemical enhancers on transdermal delivery of meloxicam in vitro

    NASA Astrophysics Data System (ADS)

    Cui, L. L.; Hou, X. M.; Jiang, J.; Li, G. D.; Liang, Y. Y.; Xin, X.

    2008-12-01

    Electret offers enhancing effect in transdermal drug delivery for altering of the arrangement of lipid molecules in the stratum corneum, forming many transient permeable apertures and enhancing the transdermal drug delivery. In this paper, meloxicam patch formulations were developed to make the comparative study of transdermal drug delivery between electret and chemical enhancers. Patches were made into control, electret, chemical enhancer and electret with chemical enhancer ones, according to the preparation procedure. The electret combined with chemical enhancer patch was designed to probe the incorporation between electret and chemical enhancer in transdermal drug delivery. The meloxicam release from the patch was found to increase in order of blank, chemical enhancer, electret and electret with chemical enhancer patch, in general.

  4. Cognitive enhancement: methods, ethics, regulatory challenges.

    PubMed

    Bostrom, Nick; Sandberg, Anders

    2009-09-01

    Cognitive enhancement takes many and diverse forms. Various methods of cognitive enhancement have implications for the near future. At the same time, these technologies raise a range of ethical issues. For example, they interact with notions of authenticity, the good life, and the role of medicine in our lives. Present and anticipated methods for cognitive enhancement also create challenges for public policy and regulation. PMID:19543814

  5. Enhanced eryptosis following gramicidin exposure.

    PubMed

    Malik, Abaid; Bissinger, Rosi; Liu, Guoxing; Liu, Guilai; Lang, Florian

    2015-05-01

    The peptide antibiotic and ionophore gramicidin has previously been shown to trigger apoptosis of nucleated cells. In analogy to apoptosis, the suicidal death of erythrocytes or eryptosis involves cell shrinkage and cell membrane scrambling with phosphatidylserine translocation to the erythrocyte surface. Triggers of eryptosis include oxidative stress, increase of cytosolic Ca2+ activity ([Ca2+]i), and ceramide. The present study explored, whether gramicidin triggers eryptosis. To this end phosphatidylserine exposure at the cell surface was estimated from annexin V binding, cell volume from forward scatter, red blood cell distribution width (RDW) from electronic particle counting, reactive oxidant species (ROS) from 2',7'-dichlorodihydrofluorescein diacetate (DCFDA) fluorescence, [Ca2+]i from Fluo3- and Fluo4 fluorescence, and ceramide abundance from binding of specific antibodies. As a result, a 24 h exposure of human erythrocytes to gramicidin significantly increased the percentage of annexin-V-binding cells (≥1 µg/mL), forward scatter (≥0.5 µg/mL) and hemolysis. Gramicidin enhanced ROS activity, [Ca2+]i and ceramide abundance at the erythrocyte surface. The stimulation of annexin-V-binding by gramicidin was significantly blunted but not abolished by removal of extracellular Ca2+. In conclusion, gramicidin stimulates phospholipid scrambling of the erythrocyte cell membrane, an effect at least partially due to induction of oxidative stress, increase of [Ca2+]i and up-regulation of ceramide abundance. Despite increase of [Ca2+]i, gramicidin increases cell volume and slightly reduces RWD. PMID:25915718

  6. Enhanced Model for Fast Ignition

    SciTech Connect

    Mason, Rodney J.

    2010-10-12

    Laser Fusion is a prime candidate for alternate energy production, capable of serving a major portion of the nation's energy needs, once fusion fuel can be readily ignited. Fast Ignition may well speed achievement of this goal, by reducing net demands on laser pulse energy and timing precision. However, Fast Ignition has presented a major challenge to modeling. This project has enhanced the computer code ePLAS for the simulation of the many specialized phenomena, which arise with Fast Ignition. The improved code has helped researchers to understand better the consequences of laser absorption, energy transport, and laser target hydrodynamics. ePLAS uses efficient implicit methods to acquire solutions for the electromagnetic fields that govern the accelerations of electrons and ions in targets. In many cases, the code implements fluid modeling for these components. These combined features, "implicitness and fluid modeling," can greatly facilitate calculations, permitting the rapid scoping and evaluation of experiments. ePLAS can be used on PCs, Macs and Linux machines, providing researchers and students with rapid results. This project has improved the treatment of electromagnetics, hydrodynamics, and atomic physics in the code. It has simplified output graphics, and provided new input that avoids the need for source code access by users. The improved code can now aid university, business and national laboratory users in pursuit of an early path to success with Fast Ignition.

  7. Enhanced Eryptosis Following Gramicidin Exposure

    PubMed Central

    Malik, Abaid; Bissinger, Rosi; Liu, Guoxing; Liu, Guilai; Lang, Florian

    2015-01-01

    The peptide antibiotic and ionophore gramicidin has previously been shown to trigger apoptosis of nucleated cells. In analogy to apoptosis, the suicidal death of erythrocytes or eryptosis involves cell shrinkage and cell membrane scrambling with phosphatidylserine translocation to the erythrocyte surface. Triggers of eryptosis include oxidative stress, increase of cytosolic Ca2+ activity ([Ca2+]i), and ceramide. The present study explored, whether gramicidin triggers eryptosis. To this end phosphatidylserine exposure at the cell surface was estimated from annexin V binding, cell volume from forward scatter, red blood cell distribution width (RDW) from electronic particle counting, reactive oxidant species (ROS) from 2',7'-dichlorodihydrofluorescein diacetate (DCFDA) fluorescence, [Ca2+]i from Fluo3- and Fluo4 fluorescence, and ceramide abundance from binding of specific antibodies. As a result, a 24 h exposure of human erythrocytes to gramicidin significantly increased the percentage of annexin-V-binding cells (≥1 µg/mL), forward scatter (≥0.5 µg/mL) and hemolysis. Gramicidin enhanced ROS activity, [Ca2+]i and ceramide abundance at the erythrocyte surface. The stimulation of annexin-V-binding by gramicidin was significantly blunted but not abolished by removal of extracellular Ca2+. In conclusion, gramicidin stimulates phospholipid scrambling of the erythrocyte cell membrane, an effect at least partially due to induction of oxidative stress, increase of [Ca2+]i and up-regulation of ceramide abundance. Despite increase of [Ca2+]i, gramicidin increases cell volume and slightly reduces RWD. PMID:25915718

  8. Does Facial Resemblance Enhance Cooperation?

    PubMed Central

    Giang, Trang; Bell, Raoul; Buchner, Axel

    2012-01-01

    Facial self-resemblance has been proposed to serve as a kinship cue that facilitates cooperation between kin. In the present study, facial resemblance was manipulated by morphing stimulus faces with the participants' own faces or control faces (resulting in self-resemblant or other-resemblant composite faces). A norming study showed that the perceived degree of kinship was higher for the participants and the self-resemblant composite faces than for actual first-degree relatives. Effects of facial self-resemblance on trust and cooperation were tested in a paradigm that has proven to be sensitive to facial trustworthiness, facial likability, and facial expression. First, participants played a cooperation game in which the composite faces were shown. Then, likability ratings were assessed. In a source memory test, participants were required to identify old and new faces, and were asked to remember whether the faces belonged to cooperators or cheaters in the cooperation game. Old-new recognition was enhanced for self-resemblant faces in comparison to other-resemblant faces. However, facial self-resemblance had no effects on the degree of cooperation in the cooperation game, on the emotional evaluation of the faces as reflected in the likability judgments, and on the expectation that a face belonged to a cooperator rather than to a cheater. Therefore, the present results are clearly inconsistent with the assumption of an evolved kin recognition module built into the human face recognition system. PMID:23094095

  9. Enhanced potentiometry by metallic nanoparticles.

    PubMed

    Noyhouzer, T; Valdinger, I; Mandler, D

    2013-09-01

    Measuring the oxidation-reduction potential (Eh) requires an interface that is not selective toward specific species but exchanges electrons with all redox couples in the solution. Sluggish electron transfer (ET) kinetics with the species will not reflect the "true" Eh of the solution. Here, we present a novel approach by which adsorbed metal nanoparticles (NPs) are used for enhancing ET exchange rates between redox species and electrode surface and therefore affect significantly the measurement of the open circuit potential (OCP) and cyclic voltammetry (CV). The OCP and CV of various organic and inorganic species such as l-dopa, dopac, iron(II), and iodide are measured by bare stainless steel and by stainless steel modified by either Pt or Au NPs. We study the effect of the surface coverage of the stainless steel surface by NPs on the electrochemical response. Moreover, the stainless steel electrode was modified simultaneously by Au and Pt nanoparticles. This improved concurrently the stainless steel response (CV and potentiometry) toward two different species; l-dopa, which shows fast electron transfer on Pt, and catechol, which exhibits fast electron transfer on Au. We believe that this approach could be a first step toward developing a superior electrode for measuring the "true" Eh of complex aquatic systems. PMID:23947748

  10. Ultrasound enhanced thrombolysis: Clinical evidence

    NASA Astrophysics Data System (ADS)

    Alexandrov, Andrei V.

    2005-04-01

    Phase II CLOTBUST randomized clinical trial (Houston, Barcelona, Edmonton, Calgary) evaluated patients with acute ischemic stroke due to intracranial occlusion and treated with intravenous tissue plasminogen activator (TPA) within 3 h of symptom onset. Randomization: monitoring with pulsed wave 2 MHz transcranial Doppler (TCD) (Target) or placebo monitoring (Control). Safety: symptomatic bleeding to the brain (sICH). Primary end-point: complete recanalization on TCD or dramatic clinical recovery by the total NIHSS score <3, or improvement by >10 NIHSS points within 2 hours after TPA bolus. All projected 126 patients were randomized 1:1 to target (median NIHSS 16) or control (NIHSS 17). sICH: 4.8% Target, 4.8% Controls. Primary end-point was achieved by 31 (49%, Target) versus 19 (30%, Control), p<0.03. At 3 months, 22 (42% Target) and 14 (29% Control) patients achieved favorable outcomes. Continuous TCD monitoring of intracranial occlusion safely augments TPA-induced arterial recanalization, and 2 MHz diagnostic ultrasound has a positive biological activity that aids systemic thrombolytic therapy. For the first time in clinical medicine, the CLOTBUST trial provides the evidence that ultrasound enhances thrombolytic activity of a drug in humans thereby confirming intense multi-disciplinary experimental research conducted worldwide for the past 30 years.

  11. Facebook Enhances Antidepressant Pharmacotherapy Effects

    PubMed Central

    Mota Pereira, Jorge

    2014-01-01

    Treatment-resistant major depressive disorder (TR-MDD) is a complex condition, with very low remission rates. In recent years some studies have been conducted on the implementation of cognitive behavioral therapy and psychodynamic psychotherapy interventions via the Internet to MDD patients, and results have been promising. However, there have been no studies in patients with TR-MDD nor with the use of Facebook with the psychiatrist as “friend.” 60 TR-MDD patients were randomized to one of three groups: Facebook group with psychiatrist as “friend,” Facebook group without psychiatrist as “friend,” and control group (no Facebook use). Both Facebook groups spent at least 1 hour/day on Facebook, 7 days/week, during the 3 months. All patients maintained their usual pharmacotherapy. All participants were evaluated at baseline and at 1, 2, and 3 months for depressive symptoms using HAD17 and BDI-II. Results show that both Facebook groups had a decrease on HADM17 and BDI-II scores as well as higher remission and response rates than the control group, with better results if the psychiatrist was a “friend” on Facebook. Therefore, in TR-MDD, Facebook can be used as an effective enhancement therapy, adjuvant to pharmacological therapy with regular consultations, especially if the psychiatrist is the patient's online “friend.” PMID:24574930

  12. Irradiation enhancement of biomass conversion

    NASA Astrophysics Data System (ADS)

    Smith, G. S.; Kiesling, H. E.; Galyean, M. L.; Bader, J. R.

    The vast supply of cellulosic agricultural residues and industrial by-products that is produced each year is a prospective resource of biomass suitable for conversion to useful products such as feedstock for the chemicals industry and feedstuffs for the livestock industry. Conversions of such biomass is poor at present, and utilization is inefficient, because of physio-chemical barriers to biological degradation and (or) anti-quality components such as toxicants that restrict biological usages. Improvements in biodegradability of ligno-cellulosic materials have been accomplished by gamma-ray and electron-beam irradiation at intermediate dosage (˜ 50 Mrad; .5 MGy); but applications of the technology have been hampered by questionable interpretations of results. Recent research with organic wastes such as sewage sludge and straw suggests opportunity for important applications of irradiation technology in enhancement of biomass conversion. Data from experiments using irradiated straw as feed for ruminants are presented and discussed in relation to research on prospective usage of sewage products as feed for ruminants. Findings are discussed in regard to prospective applications in industrial fermentation processes. Possible usage of irradiation technology for destruction of toxicants in exotic plants is considered in regard to prospective new feedstuffs.

  13. Enhanced decision making through neuroscience

    NASA Astrophysics Data System (ADS)

    Szu, Harold; Jung, TP; Makeig, Scott

    2012-06-01

    We propose to enhance the decision making of pilot, co-pilot teams, over a range of vehicle platforms, with the aid of neuroscience. The goal is to optimize this collaborative decision making interplay in time-critical, stressful situations. We will research and measure human facial expressions, personality typing, and brainwave measurements to help answer questions related to optimum decision-making in group situations. Further, we propose to examine the nature of intuition in this decision making process. The brainwave measurements will be facilitated by a University of California, San Diego (UCSD) developed wireless Electroencephalography (EEG) sensing cap. We propose to measure brainwaves covering the whole head area with an electrode density of N=256, and yet keep within the limiting wireless bandwidth capability of m=32 readouts. This is possible because solving Independent Component Analysis (ICA) and finding the hidden brainwave sources allow us to concentrate selective measurements with an organized sparse source -->s sensing matrix [Φs], rather than the traditional purely random compressive sensing (CS) matrix[Φ].

  14. Holographic enhanced remote sensing system

    NASA Technical Reports Server (NTRS)

    Iavecchia, Helene P.; Gaynor, Edwin S.; Huff, Lloyd; Rhodes, William T.; Rothenheber, Edward H.

    1990-01-01

    The Holographic Enhanced Remote Sensing System (HERSS) consists of three primary subsystems: (1) an Image Acquisition System (IAS); (2) a Digital Image Processing System (DIPS); and (3) a Holographic Generation System (HGS) which multiply exposes a thermoplastic recording medium with sequential 2-D depth slices that are displayed on a Spatial Light Modulator (SLM). Full-parallax holograms were successfully generated by superimposing SLM images onto the thermoplastic and photopolymer. An improved HGS configuration utilizes the phase conjugate recording configuration, the 3-SLM-stacking technique, and the photopolymer. The holographic volume size is currently limited to the physical size of the SLM. A larger-format SLM is necessary to meet the desired 6 inch holographic volume. A photopolymer with an increased photospeed is required to ultimately meet a display update rate of less than 30 seconds. It is projected that the latter two technology developments will occur in the near future. While the IAS and DIPS subsystems were unable to meet NASA goals, an alternative technology is now available to perform the IAS/DIPS functions. Specifically, a laser range scanner can be utilized to build the HGS numerical database of the objects at the remote work site.

  15. Enhancer Identification through Comparative Genomics

    PubMed Central

    Visel, Axel; Bristow, James; Pennacchio, Len A.

    2007-01-01

    With the availability of genomic sequence from numerous vertebrates, a paradigm shift has occurred in the identification of distant-acting gene regulatory elements. In contrast to traditional gene-centric studies in which investigators randomly scanned genomic fragments that flank genes of interest in functional assays, the modern approach begins electronically with publicly available comparative sequence datasets that provide investigators with prioritized lists of putative functional sequences based on their evolutionary conservation. However, although a large number of tools and resources are now available, application of comparative genomic approaches remains far from trivial. In particular, it requires users to dynamically consider the species and methods for comparison depending on the specific biological question under investigation. While there is currently no single general rule to this end, it is clear that when applied appropriately, comparative genomic approaches exponentially increase our power in generating biological hypotheses for subsequent experimental testing. It is anticipated that cardiac-related genes and the identification of their distant-acting transcriptional enhancers are particularly poised to benefit from these modern capabilities. PMID:17276707

  16. Facebook enhances antidepressant pharmacotherapy effects.

    PubMed

    Mota Pereira, Jorge

    2014-01-01

    Treatment-resistant major depressive disorder (TR-MDD) is a complex condition, with very low remission rates. In recent years some studies have been conducted on the implementation of cognitive behavioral therapy and psychodynamic psychotherapy interventions via the Internet to MDD patients, and results have been promising. However, there have been no studies in patients with TR-MDD nor with the use of Facebook with the psychiatrist as "friend." 60 TR-MDD patients were randomized to one of three groups: Facebook group with psychiatrist as "friend," Facebook group without psychiatrist as "friend," and control group (no Facebook use). Both Facebook groups spent at least 1 hour/day on Facebook, 7 days/week, during the 3 months. All patients maintained their usual pharmacotherapy. All participants were evaluated at baseline and at 1, 2, and 3 months for depressive symptoms using HAD17 and BDI-II. Results show that both Facebook groups had a decrease on HADM17 and BDI-II scores as well as higher remission and response rates than the control group, with better results if the psychiatrist was a "friend" on Facebook. Therefore, in TR-MDD, Facebook can be used as an effective enhancement therapy, adjuvant to pharmacological therapy with regular consultations, especially if the psychiatrist is the patient's online "friend." PMID:24574930

  17. Carbon-enhanced VRLA batteries.

    SciTech Connect

    Enos, David George; Hund, Thomas D.; Shane, Rod

    2010-10-01

    The addition of certain forms of carbon to the negative plate in valve regulated lead acid (VRLA) batteries has been demonstrated to increase the cycle life of such batteries by an order of magnitude or more under high-rate, partial-state-of-charge operation. Such performance will provide a significant impact, and in some cases it will be an enabling feature for applications including hybrid electric vehicles, utility ancillary regulation services, wind farm energy smoothing, and solar photovoltaic energy smoothing. There is a critical need to understnd how the carbon interacts with the negative plate and achieves the aforementioned benefits at a fundamental level. Such an understanding will not only enable the performance of such batteries to be optimzied, but also to explore the feasibility of applying this technology to other battery chemistries. In partnership with the East Penn Manufacturing, Sandia will investigate the electrochemical function of the carbon and possibly identify improvements to its anti-sulfation properties. Shiomi, et al. (1997) discovered that the addition of carbon to the negative active material (NAM) substantially reduced PbSO{sub 4} accumulation in high rate, partial state of charge (HRPSoC) cycling applications. This improved performance with a minimal cost. Cycling applications that were uneconomical for traditional VRLA batteries are viable for the carbon enhanced VRLA. The overall goal of this work is to quantitatively define the role that carbon plays in the electrochemistry of a VRLA battery.

  18. Gold nanoparticles enhancing protontherapy efficiency.

    PubMed

    Torrisi, Lorenzo

    2015-01-01

    The insertion of gold nanoparticles in biological liquids, tissues and organs permits to increase the equivalent atomic number of the medium that, if used as target to be irradiated by ionizing radiation, permits an increment of the absorbed dose. No toxic nanoparticles, such as the Au, can be injected in the cancer tissues at different concentrations before using a localized treatment that uses energetic proton beams for radiotherapy. Due to the high density and atomic number of the used gold nanoparticles, the absorbed radiation dose can be increased to about a factor six per cent using relatively low concentration of nanoparticles injectable as solution in the tumor tissue. This means to reduce the exposition to ionizing radiation or to increase the dose to the tumor site. Simulation programs of proton energy loss in tissues, using SRIM Code, are employed to evaluate the Bragg peak enhancing in presence of Au nanoparticles, so it will be presented and discussed. Some research findings and patents in the gold nanoparticle preparation and application to Medicine are reviewed in the present paper. PMID:25986229

  19. Laser Image Contrast Enhancement System

    NASA Technical Reports Server (NTRS)

    Kurtz, Robert L. (Inventor); Holmes, Richard R. (Inventor); Witherow, William K. (Inventor)

    2002-01-01

    An optical image enhancement system provides improved image contrast in imaging of a target in high temperature surroundings such as a furnace. The optical system includes a source of vertically polarized light such as laser and a beam splitter for receiving the light and directing the light toward the target. A retardation plate is affixed to a target-facing surface of the beam splitter and a vertical polarizer is disposed along a common optical path with the beam splitter between the retardation plate and the target. A horizontal polarizer disposed in the common optical path, receives light passing through a surface of the beam splitter opposed to the target-facing surface. An image detector is disposed at one end of the optical path. A band pass filter having a band pass filter characteristic matching the frequency of the vertically polarized light source is disposed in the path between the horizontal polarizer and the image detector. The use of circular polarization, together with cross polarizers, enables the reflected light to be passed to the detector while blocking thermal radiation.

  20. Optical nanogap matrices for plasmonic enhancement applications

    NASA Astrophysics Data System (ADS)

    Bauman, Stephen J.; Debu, Desalegn T.; Hill, Avery M.; Novak, Eric C.; Natelson, Douglas; Herzog, Joseph B.

    2014-09-01

    Plasmonic structures can be used to enhance electromagnetic radiation, and nanoscale (<5 nm) gaps can increase this enhancement even further. Fabrication of these desired structures involves using a relatively new, previously developed self-aligned process to overcome typical electron beam lithography resolution limits. The resulting nanogap structures have been shown to exhibit enhanced optical emission. This technique enables the fabrication of a large-area two-dimensional matrix of such nanostructures which could prove useful for photovoltaics, plasmonically enhanced Raman spectroscopy, biosensing, and other optoelectronic applications. Computational electromagnetic simulations of the structures will prove useful for predicting behavior upon interaction with light and for experimental comparison.

  1. Sunrise enhancement of equatorial vertical plasma drift

    NASA Astrophysics Data System (ADS)

    Liu, Libo; Zhang, Ruilong; Le, Huijun

    2016-04-01

    Sunrise enhancement in vertical plasma drift over equatorial regions is not discernible in the statistical picture compared with the significant enhancement during dusk hours. In this report, it is the first time to investigate the occurrence of the dawn enhancement in the equatorial ionospheric vertical plasma drift from ROCSAT-1 observations during geomagnetic quiet times. The dawn enhancements occur most frequently in June solstice and least frequently in December solstice. The statistical survey shows that the occurrence depends on the magnetic declination. The enhancement has the strongest amplitude in regions near 320° longitude and peaks during June solstice. The dawn enhancement reaches its peak after the sunrise in conjugated E regions. Furthermore, it is found that the dawn enhancement is closely related to the difference between the sunrise times in the conjugated E regions (sunrise time lag). The dawn enhancement occurs easily in regions with a large sunrise time lag. Moreover, we will report the effects of the sunrise enhancement of vertical plasma drift on the equatorial ionosphere as indicated from the observations and model simulations. We thanks National Central University of Taiwan providing the ROCSAT-1 data. The Ap and F107 indices are obtained from the National Geophysical Data Center (http://spidr.ngdc.noaa.gov/spidr/). This research is supported by National Natural Science Foundation of China (41231065), the Chinese Academy of Sciences project (KZZD-EW-01-3), National Key Basic Research Program of China (2012CB825604) and National Natural Science Foundation of China (41321003).

  2. Inhomogeneous thermal conductivity enhances thermoelectric cooling

    NASA Astrophysics Data System (ADS)

    Lu, Tingyu; Zhou, Jun; Li, Nianbei; Yang, Ronggui; Li, Baowen

    2014-12-01

    We theoretically investigate the enhancement of thermoelectric cooling performance in thermoelectric refrigerators made of materials with inhomogeneous thermal conductivity, beyond the usual practice of enhancing thermoelectric figure of merit (ZT) of materials. The dissipation of the Joule heat in such thermoelectric refrigerators is asymmetric which can give rise to better thermoelectric cooling performance. Although the thermoelectric figure of merit and the coefficient-of-performance are slightly enhanced, both the maximum cooling power and the maximum cooling temperature difference can be enhanced significantly. This finding can be used to increase the heat absorption at the cold end. We further find that the asymmetric dissipation of Joule heat leads to thermal rectification.

  3. SEA: a super-enhancer archive.

    PubMed

    Wei, Yanjun; Zhang, Shumei; Shang, Shipeng; Zhang, Bin; Li, Song; Wang, Xinyu; Wang, Fang; Su, Jianzhong; Wu, Qiong; Liu, Hongbo; Zhang, Yan

    2016-01-01

    Super-enhancers are large clusters of transcriptional enhancers regarded as having essential roles in driving the expression of genes that control cell identity during development and tumorigenesis. The construction of a genome-wide super-enhancer database is urgently needed to better understand super-enhancer-directed gene expression regulation for a given biology process. Here, we present a specifically designed web-accessible database, Super-Enhancer Archive (SEA, http://sea.edbc.org). SEA focuses on integrating super-enhancers in multiple species and annotating their potential roles in the regulation of cell identity gene expression. The current release of SEA incorporates 83 996 super-enhancers computationally or experimentally identified in 134 cell types/tissues/diseases, including human (75 439, three of which were experimentally identified), mouse (5879, five of which were experimentally identified), Drosophila melanogaster (1774) and Caenorhabditis elegans (904). To facilitate data extraction, SEA supports multiple search options, including species, genome location, gene name, cell type/tissue and super-enhancer name. The response provides detailed (epi)genetic information, incorporating cell type specificity, nearby genes, transcriptional factor binding sites, CRISPR/Cas9 target sites, evolutionary conservation, SNPs, H3K27ac, DNA methylation, gene expression and TF ChIP-seq data. Moreover, analytical tools and a genome browser were developed for users to explore super-enhancers and their roles in defining cell identity and disease processes in depth. PMID:26578594

  4. SEA: a super-enhancer archive

    PubMed Central

    Wei, Yanjun; Zhang, Shumei; Shang, Shipeng; Zhang, Bin; Li, Song; Wang, Xinyu; Wang, Fang; Su, Jianzhong; Wu, Qiong; Liu, Hongbo; Zhang, Yan

    2016-01-01

    Super-enhancers are large clusters of transcriptional enhancers regarded as having essential roles in driving the expression of genes that control cell identity during development and tumorigenesis. The construction of a genome-wide super-enhancer database is urgently needed to better understand super-enhancer-directed gene expression regulation for a given biology process. Here, we present a specifically designed web-accessible database, Super-Enhancer Archive (SEA, http://sea.edbc.org). SEA focuses on integrating super-enhancers in multiple species and annotating their potential roles in the regulation of cell identity gene expression. The current release of SEA incorporates 83 996 super-enhancers computationally or experimentally identified in 134 cell types/tissues/diseases, including human (75 439, three of which were experimentally identified), mouse (5879, five of which were experimentally identified), Drosophila melanogaster (1774) and Caenorhabditis elegans (904). To facilitate data extraction, SEA supports multiple search options, including species, genome location, gene name, cell type/tissue and super-enhancer name. The response provides detailed (epi)genetic information, incorporating cell type specificity, nearby genes, transcriptional factor binding sites, CRISPR/Cas9 target sites, evolutionary conservation, SNPs, H3K27ac, DNA methylation, gene expression and TF ChIP-seq data. Moreover, analytical tools and a genome browser were developed for users to explore super-enhancers and their roles in defining cell identity and disease processes in depth. PMID:26578594

  5. Spinal Cord Ring Enhancement in Multiple Sclerosis

    PubMed Central

    Klawiter, Eric C; Benzinger, Tammie; Roy, Abhik; Naismith, Robert T; Parks, Becky J; Cross, Anne H

    2010-01-01

    Objective Describe the clinical and imaging characteristics of spinal cord ring enhancement in multiple sclerosis (MS). Design Clinical case series. Setting Academic referral center. Patients Twenty MS subjects with spinal cord ring enhancement were retrospectively identified from 322 cervical and thoracic spinal cord MRI studies over a 3 year period. Main Outcome Measures Demographics, disability, pattern of enhancement on spinal cord imaging, and concomitant brain magnetic resonance imaging (MRI) were determined. Results Ring enhancement was seen in 20 subjects with spinal cord enhancement, most commonly in the cervical cord. Incomplete or ‘open’ ring enhancement was the dominant pattern in 19 of 20 (95%) subjects. Concurrent ring enhancing brain lesions were present in 40% of subjects. At the time of the MRI, the Expanded Disability Status Scale (EDSS) ranged from 1.0–7.0 (median 3.0). Conclusion Ring enhancement is not an uncommon pattern for MS spinal cord lesions, occurring with a prevalence of 6.2% (20/322). The most common pattern was incomplete ring enhancement in the cervical spinal cord. Recognition of this pattern may improve and expedite the diagnosis of MS and preclude need for invasive diagnostic interventions. PMID:21060017

  6. Factors affecting enhanced video quality preferences

    PubMed Central

    Satgunam, PremNandhini; Woods, Russell L; Bronstad, P Matthew; Peli, Eli

    2013-01-01

    The development of video quality metrics requires methods for measuring perceived video quality. Most such metrics are designed and tested using databases of images degraded by compression and scored using opinion ratings. We studied video quality preferences for enhanced images of normally-sighted participants using the method of paired comparisons with a thorough statistical analysis. Participants (n=40) made pair-wise comparisons of high definition (HD) video clips enhanced at four different levels using a commercially available enhancement device. Perceptual scales were computed with binary logistic regression to estimate preferences for each level and to provide statistical inference of the differences among levels and the impact of other variables. While moderate preference for enhanced videos was found, two unexpected effects were also uncovered: (1) Participants could be broadly classified into two groups: those who preferred enhancement ("Sharp") and those who disliked enhancement ("Smooth"). (2) Enhancement preferences depended on video content, particularly for human faces to be enhanced less. The results suggest that algorithms to evaluate image quality (at least for enhancement) may need to be adjusted or applied differentially based on video content and viewer preferences. The possible impact of similar effects on image quality of compressed video needs to be evaluated. PMID:24107400

  7. Stroboscopic Training Enhances Anticipatory Timing

    PubMed Central

    SMITH, TREVOR Q.; MITROFF, STEPHEN R.

    2012-01-01

    The dynamic aspects of sports often place heavy demands on visual processing. As such, an important goal for sports training should be to enhance visual abilities. Recent research has suggested that training in a stroboscopic environment, where visual experiences alternate between visible and obscured, may provide a means of improving attentional and visual abilities. The current study explored whether stroboscopic training could impact anticipatory timing – the ability to predict where a moving stimulus will be at a specific point in time. Anticipatory timing is a critical skill for both sports and non-sports activities, and thus finding training improvements could have broad impacts. Participants completed a pre-training assessment that used a Bassin Anticipation Timer to measure their abilities to accurately predict the timing of a moving visual stimulus. Immediately after this initial assessment, the participants completed training trials, but in one of two conditions. Those in the Control condition proceeded as before with no change. Those in the Strobe condition completed the training trials while wearing specialized eyewear that had lenses that alternated between transparent and opaque (rate of 100ms visible to 150ms opaque). Post-training assessments were administered immediately after training, 10-minutes after training, and 10-days after training. Compared to the Control group, the Strobe group was significantly more accurate immediately after training, was more likely to respond early than to respond late immediately after training and 10 minutes later, and was more consistent in their timing estimates immediately after training and 10 minutes later. PMID:27182391

  8. Enhanced absorption cycle computer model

    NASA Astrophysics Data System (ADS)

    Grossman, G.; Wilk, M.

    1993-09-01

    Absorption heat pumps have received renewed and increasing attention in the past two decades. The rising cost of electricity has made the particular features of this heat-powered cycle attractive for both residential and industrial applications. Solar-powered absorption chillers, gas-fired domestic heat pumps, and waste-heat-powered industrial temperature boosters are a few of the applications recently subjected to intensive research and development. The absorption heat pump research community has begun to search for both advanced cycles in various multistage configurations and new working fluid combinations with potential for enhanced performance and reliability. The development of working absorption systems has created a need for reliable and effective system simulations. A computer code has been developed for simulation of absorption systems at steady state in a flexible and modular form, making it possible to investigate various cycle configurations with different working fluids. The code is based on unit subroutines containing the governing equations for the system's components and property subroutines containing thermodynamic properties of the working fluids. The user conveys to the computer an image of his cycle by specifying the different subunits and their interconnections. Based on this information, the program calculates the temperature, flow rate, concentration, pressure, and vapor fraction at each state point in the system, and the heat duty at each unit, from which the coefficient of performance (COP) may be determined. This report describes the code and its operation, including improvements introduced into the present version. Simulation results are described for LiBr-H2O triple-effect cycles, LiCl-H2O solar-powered open absorption cycles, and NH3-H2O single-effect and generator-absorber heat exchange cycles. An appendix contains the user's manual.

  9. Robotically enhanced rubber hand illusion.

    PubMed

    Arata, Jumpei; Hattori, Masashi; Ichikawa, Shohei; Sakaguchi, Masamichi

    2014-01-01

    The rubber hand illusion is a well-known multisensory illusion. In brief, watching a rubber hand being stroked by a paintbrush while one's own unseen hand is synchronously stroked causes the rubber hand to be attributed to one's own body and to "feel like it's my hand." The rubber hand illusion is thought to be triggered by the synchronized tactile stimulation of both the subject's hand and the fake hand. To extend the conventional rubber hand illusion, we introduce robotic technology in the form of a master-slave telemanipulator. The developed one degree-of-freedom master-slave system consists of an exoskeleton master equipped with an optical encoder that is worn on the subject's index finger and a motor-actuated index finger on the rubber hand, which allows the subject to perform unilateral telemanipulation. The moving rubber hand illusion has been studied by several researchers in the past with mechanically connected rigs between the subject's body and the fake limb. The robotic instruments let us investigate the moving rubber hand illusion with less constraints, thus behaving closer to the classic rubber hand illusion. In addition, the temporal delay between the body and the fake limb can be precisely manipulated. The experimental results revealed that the robotic instruments significantly enhance the rubber hand illusion. The time delay is significantly correlated with the effect of the multisensory illusion, and the effect significantly decreased at time delays over 100 ms. These findings can potentially contribute to the investigations of neural mechanisms in the field of neuroscience and of master-slave systems in the field of robotics. PMID:25532152

  10. Electronic enhancement of tear secretion

    NASA Astrophysics Data System (ADS)

    Brinton, Mark; Lim Chung, Jae; Kossler, Andrea; Kook, Koung Hoon; Loudin, Jim; Franke, Manfred; Palanker, Daniel

    2016-02-01

    Objective. To study electrical stimulation of the lacrimal gland and afferent nerves for enhanced tear secretion, as a potential treatment for dry eye disease. We investigate the response pathways and electrical parameters to safely maximize tear secretion. Approach. We evaluated the tear response to electrical stimulation of the lacrimal gland and afferent nerves in isofluorane-anesthetized rabbits. In acute studies, electrical stimulation was performed using bipolar platinum foil electrodes, implanted beneath the inferior lacrimal gland, and a monopolar electrode placed near the afferent ethmoid nerve. Wireless microstimulators with bipolar electrodes were implanted beneath the lacrimal gland for chronic studies. To identify the response pathways, we applied various pharmacological inhibitors. To optimize the stimulus, we measured tear secretion rate (Schirmer test) as a function of pulse amplitude (1.5-12 mA), duration (0.1-1 ms) and repetition rate (10-100 Hz). Main results. Stimulation of the lacrimal gland increased tear secretion by engaging efferent parasympathetic nerves. Tearing increased with stimulation amplitude, pulse duration and repetition rate, up to 70 Hz. Stimulation with 3 mA, 500 μs pulses at 70 Hz provided a 4.5 mm (125%) increase in Schirmer score. Modulating duty cycle further increased tearing up to 57%, compared to continuous stimulation in chronically implanted animals (36%). Ethmoid (afferent) nerve stimulation increased tearing similar to gland stimulation (3.6 mm) via a reflex pathway. In animals with chronically implanted stimulators, a nearly 6 mm increase (57%) was achieved with 12-fold less charge density per pulse (0.06-0.3 μC mm-2 with 170-680 μs pulses) than the damage threshold (3.5 μC mm-2 with 1 ms pulses). Significance. Electrical stimulation of the lacrimal gland or afferent nerves may be used as a treatment for dry eye disease. Clinical trials should validate this approach in patients with aqueous tear deficiency, and

  11. Enhancing Ocean Research Data Access

    NASA Astrophysics Data System (ADS)

    Chandler, Cynthia; Groman, Robert; Shepherd, Adam; Allison, Molly; Arko, Robert; Chen, Yu; Fox, Peter; Glover, David; Hitzler, Pascal; Leadbetter, Adam; Narock, Thomas; West, Patrick; Wiebe, Peter

    2014-05-01

    The Biological and Chemical Oceanography Data Management Office (BCO-DMO) works in partnership with ocean science investigators to publish data from research projects funded by the Biological and Chemical Oceanography Sections and the Office of Polar Programs Antarctic Organisms & Ecosystems Program at the U.S. National Science Foundation. Since 2006, researchers have been contributing data to the BCO-DMO data system, and it has developed into a rich repository of data from ocean, coastal and Great Lakes research programs. While the ultimate goal of the BCO-DMO is to ensure preservation of NSF funded project data and to provide open access to those data, achievement of those goals is attained through a series of related phases that benefits from active collaboration and cooperation with a large community of research scientists as well as curators of data and information at complementary data repositories. The BCO-DMO is just one of many intermediate data management centers created to facilitate long-term preservation of data and improve access to ocean research data. Through partnerships with other data management professionals and active involvement in local and global initiatives, BCO-DMO staff members are working to enhance access to ocean research data available from the online BCO-DMO data system. Continuing efforts in use of controlled vocabulary terms, development of ontology design patterns and publication of content as Linked Open Data are contributing to improved discovery and availability of BCO-DMO curated data and increased interoperability of related content available from distributed repositories. We will demonstrate how Semantic Web technologies (e.g. RDF/XML, SKOS, OWL and SPARQL) have been integrated into BCO-DMO data access and delivery systems to better serve the ocean research community and to contribute to an expanding global knowledge network.

  12. Lift enhancement by trapped vortex

    NASA Technical Reports Server (NTRS)

    Rossow, Vernon J.

    1992-01-01

    The viewgraphs and discussion of lift enhancement by trapped vortex are provided. Efforts are continuously being made to find simple ways to convert wings of aircraft from an efficient cruise configuration to one that develops the high lift needed during landing and takeoff. The high-lift configurations studied here consist of conventional airfoils with a trapped vortex over the upper surface. The vortex is trapped by one or two vertical fences that serve as barriers to the oncoming stream and as reflection planes for the vortex and the sink that form a separation bubble on top of the airfoil. Since the full three-dimensional unsteady flow problem over the wing of an aircraft is so complicated that it is hard to get an understanding of the principles that govern the vortex trapping process, the analysis is restricted here to the flow field illustrated in the first slide. It is assumed that the flow field between the two end plates approximates a streamwise strip of the flow over a wing. The flow between the endplates and about the airfoil consists of a spanwise vortex located between the suction orifices in the endplates. The spanwise fence or spoiler located near the nose of the airfoil serves to form a separated flow region and a shear layer. The vorticity in the shear layer is concentrated into the vortex by withdrawal of fluid at the suction orifices. As the strength of the vortex increases with time, it eventually dominates the flow in the separated region so that a shear or vertical layer is no longer shed from the tip of the fence. At that point, the vortex strength is fixed and its location is such that all of the velocity contributions at its center sum to zero thereby making it an equilibrium point for the vortex. The results of a theoretical analysis of such an idealized flow field are described.

  13. Enhancing critical current density of cuprate superconductors

    DOEpatents

    Chaudhari, Praveen

    2015-06-16

    The present invention concerns the enhancement of critical current densities in cuprate superconductors. Such enhancement of critical current densities include using wave function symmetry and restricting movement of Abrikosov (A) vortices, Josephson (J) vortices, or Abrikosov-Josephson (A-J) vortices by using the half integer vortices associated with d-wave symmetry present in the grain boundary.

  14. Arousal-Enhanced Location Memory for Pictures

    ERIC Educational Resources Information Center

    Mather, Mara; Nesmith, Kathryn

    2008-01-01

    Four experiments revealed arousal-enhanced location memory for pictures. After an incidental encoding task, participants were more likely to remember the locations of positive and negative arousing pictures than the locations of non-arousing pictures, indicating better binding of location to picture. This arousal-enhanced binding effect did not…

  15. Self-Enhancing Illusions among Chinese Schoolchildren.

    ERIC Educational Resources Information Center

    Falbo, Toni; And Others

    1997-01-01

    Demonstrates that East Asian children (EAC) do engage in some forms of self-enhancing illusions. Responses from 4,000 elementary school students reveal EACs see themselves as possessing more positive attributes than others. Variations in self-enhancing illusions were found for age, gender, and region of residence. Results are discussed in terms of…

  16. Enhancing Engineering Education through Engineering Management

    ERIC Educational Resources Information Center

    Pence, Kenneth R.; Rowe, Christopher J.

    2012-01-01

    Engineering Management courses are added to a traditional engineering curriculum to enhance the value of an undergraduate's engineering degree. A four-year engineering degree often leaves graduates lacking in business and management acumen. Engineering management education covers topics enhancing the value of new graduates by teaching management…

  17. Enhancement of retronasal odors by taste.

    PubMed

    Green, Barry G; Nachtigal, Danielle; Hammond, Samuel; Lim, Juyun

    2012-01-01

    Psychophysical studies of interactions between retronasal olfaction and taste have focused most often on the enhancement of tastes by odors, which has been attributed primarily to a response bias (i.e., halo dumping). Based upon preliminary evidence that retronasal odors could also be enhanced by taste, the present study measured both forms of enhancement using appropriate response categories. In the first experiment, subjects rated taste ("sweet," "sour," "salty," and "bitter") and odor ("other") intensity for aqueous samples of 3 tastants (sucrose, NaCl, and citric acid) and 3 odorants (vanillin, citral, and furaneol), both alone and in taste-odor mixtures. The results showed that sucrose, but not the other taste stimuli, significantly increased the perceived intensity of all 3 odors. Enhancement of tastes by odors was inconsistent and generally weaker than enhancement of odors by sucrose. A second experiment used a flavored beverage and a custard dessert to test whether the findings from the first experiment would hold for the perception of actual foods. Adding sucrose significantly enhanced the intensity of "cherry" and "vanilla" flavors, whereas adding vanillin did not significantly enhance the intensity of sweetness. It is proposed that enhancement of retronasal odors by a sweet stimulus results from an adaptive sensory mechanism that serves to increase the salience of the flavor of nutritive foods. PMID:21798851

  18. Nanoparticle Based Surface-Enhanced Raman Spectroscopy

    SciTech Connect

    Talley, C E; Huser, T R; Hollars, C W; Jusinski, L; Laurence, T; Lane, S M

    2005-01-03

    Surface-enhanced Raman scattering is a powerful tool for the investigation of biological samples. Following a brief introduction to Raman and surface-enhanced Raman scattering, several examples of biophotonic applications of SERS are discussed. The concept of nanoparticle based sensors using SERS is introduced and the development of these sensors is discussed.

  19. Unsuccessful Retrieval Attempts Enhance Subsequent Learning

    ERIC Educational Resources Information Center

    Kornell, Nate; Hays, Matthew Jensen; Bjork, Robert A.

    2009-01-01

    Taking tests enhances learning. But what happens when one cannot answer a test question--does an unsuccessful retrieval attempt impede future learning or enhance it? The authors examined this question using materials that ensured that retrieval attempts would be unsuccessful. In Experiments 1 and 2, participants were asked fictional…

  20. Surfactant and process for enhanced oil recovery

    SciTech Connect

    Stapp, P. R.

    1985-03-12

    A novel surfactant is formed by reacting maleic anhydride with a polynuclear aromatic compound having a molecular weight of at least 155. A novel surfactant system useful in enhanced oil recovery containing the above surfactant is also provided. In addition, an improved process for the enhanced recovery of oil is provided utilizing the novel surfactant system.

  1. ENHANCED PROCESSING OF GREEN SOLVENTS - PHASE I

    EPA Science Inventory

    Solvents are a valuable processing tool in the chemical and related industries. Solvents are used to enhance mass transfer, heat transfer and in most cases are a processing aid and eventually are not used in the final product but to enhance the fabrication of the final pr...

  2. College Enhancement Strategies and Socioeconomic Inequality

    ERIC Educational Resources Information Center

    Wolniak, Gregory C.; Wells, Ryan S.; Engberg, Mark E.; Manly, Catherine A.

    2016-01-01

    The study provides new information on the relationships between students' socioeconomic backgrounds, utilization of college enhancement strategies, and subsequent 4-year college enrollment. Enhancement strategies represent student behaviors used to bolster the competitiveness of a college application, such as Advanced Placement exams and a variety…

  3. Online Faculty Satisfaction and Quality Enhancement Initiatives

    ERIC Educational Resources Information Center

    Satterlee, Anita G.

    2010-01-01

    The purpose of this paper is to examine possible effects of an institution's quality enhancement initiatives on the job satisfaction of online faculty. Quality enhancement initiatives are a normal part of the accreditation process and faculty shoulder some of the responsibility for success of those initiatives. Therefore, it is imperative that…

  4. Conceptual and practical problems of moral enhancement.

    PubMed

    Beck, Birgit

    2015-05-01

    Recently, the debate on human enhancement has shifted from familiar topics like cognitive enhancement and mood enhancement to a new and - to no one's surprise - controversial subject, namely moral enhancement. Some proponents from the transhumanist camp allude to the 'urgent need' of improving the moral conduct of humankind in the face of ever growing technological progress and the substantial dangers entailed in this enterprise. Other thinkers express more sceptical views about this proposal. As the debate has revealed so far, there is no shared opinion among philosophers (or scientists) about the meaning, prospects, and ethical evaluation of moral enhancement. In this article I will address several conceptual and practical problems of this issue, in order to encourage discussion about the prospects of (thinking about) moral enhancement in the future. My assumption is that (i) for the short term, there is little chance of arriving at an agreement on the proper understanding of morality and the appropriateness of one single (meta-)ethical theory; (ii) apart from this, there are further philosophical puzzles loosely referred to in the debate which add to theoretical confusion; and (iii) even if these conceptual problems could be solved, there are still practical problems to be smoothed out if moral enhancement is ever to gain relevance apart from merely theoretical interest. My tentative conclusion, therefore, will be that moral enhancement is not very likely to be made sense of - let alone realized - in the medium-term future. PMID:24654942

  5. Sensor fusion method for machine performance enhancement

    SciTech Connect

    Mou, J.I.; King, C.; Hillaire, R.; Jones, S.; Furness, R.

    1998-03-01

    A sensor fusion methodology was developed to uniquely integrate pre-process, process-intermittent, and post-process measurement and analysis technology to cost-effectively enhance the accuracy and capability of computer-controlled manufacturing equipment. Empirical models and computational algorithms were also developed to model, assess, and then enhance the machine performance.

  6. Digital enhancement of flow field images

    NASA Technical Reports Server (NTRS)

    Kudlinski, Robert A.; Park, Stephen K.

    1988-01-01

    Most photographs of experimentally generated fluid flow fields have inherently poor photographic quality, specifically low contrast. Thus, there is a need to establish a process for quickly and accurately enhancing these photographs to provide improved versions for physical interpretation, analysis, and publication. A sequence of digital image processing techniques which have been demonstrated to effectively enhance such photographs is described.

  7. 76 FR 1138 - Enhanced Assessment Instruments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-07

    ... under the Enhanced Assessment Instruments Grant (EAG) competition. The Secretary may use one or more of... enhance the ] quality of assessment instruments and systems used by States for measuring the academic... the primary indicator of student academic achievement and, hence, a crucial measure of State...

  8. Enhancement of Retronasal Odors by Taste

    PubMed Central

    Nachtigal, Danielle; Hammond, Samuel; Lim, Juyun

    2012-01-01

    Psychophysical studies of interactions between retronasal olfaction and taste have focused most often on the enhancement of tastes by odors, which has been attributed primarily to a response bias (i.e., halo dumping). Based upon preliminary evidence that retronasal odors could also be enhanced by taste, the present study measured both forms of enhancement using appropriate response categories. In the first experiment, subjects rated taste (“sweet,” “sour,” “salty,” and “bitter”) and odor (“other”) intensity for aqueous samples of 3 tastants (sucrose, NaCl, and citric acid) and 3 odorants (vanillin, citral, and furaneol), both alone and in taste–odor mixtures. The results showed that sucrose, but not the other taste stimuli, significantly increased the perceived intensity of all 3 odors. Enhancement of tastes by odors was inconsistent and generally weaker than enhancement of odors by sucrose. A second experiment used a flavored beverage and a custard dessert to test whether the findings from the first experiment would hold for the perception of actual foods. Adding sucrose significantly enhanced the intensity of “cherry” and “vanilla” flavors, whereas adding vanillin did not significantly enhance the intensity of sweetness. It is proposed that enhancement of retronasal odors by a sweet stimulus results from an adaptive sensory mechanism that serves to increase the salience of the flavor of nutritive foods. PMID:21798851

  9. Doping explosive materials for neutron radiographic enhancement.

    NASA Technical Reports Server (NTRS)

    Golliher, K. G.

    1971-01-01

    Discussion of studies relating to the selection of doping materials of high neutron absorption usable for enhancing the neutron radiographic imaging of explosive mixtures, without interfering with the proper chemical reaction of the explosives. The results of the studies show that gadolinium oxide is an excellent material for doping explosive mixtures to enhance the neutron radiographic image.

  10. Enhancing Vocabulary Development in Multiple Classroom Contexts.

    ERIC Educational Resources Information Center

    Harmon, Janis M.; Staton, Denise G.

    1999-01-01

    Describes ways teachers can enhance students' vocabulary development through multiple contexts available in typical middle school classroom settings. Addresses questions about vocabulary learning and offers suggestions for enhancing vocabulary with narrative and expository texts that involve multiple classroom contexts. Considers the Vocab-o-gram…

  11. Germplasm Enhancement of Maize (GEM) Project Overview

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Germplasm Enhancement of Maize Project (GEM) is a collaborative effort of public and private sector researchers to broaden and enhance the maize germplasm base. The GEM Project has cooperators from 26 private companies, 17 Universities, 7 USDA-ARS Research Units, 1 NGO, and 12 international pub...

  12. Open Educational Practices for Curriculum Enhancement

    ERIC Educational Resources Information Center

    Armellini, Alejandro; Nie, Ming

    2013-01-01

    Open educational resources (OER) and open educational practices (OEP) are relatively new areas in educational research. How OER and OEP can help practitioners enhance curricula is one of a number of under-researched topics. This article aims to enable practitioners to identify and implement appropriate open practices to enhance higher education…

  13. Bandwidth enhancement of dielectric resonator antennas

    NASA Technical Reports Server (NTRS)

    Lee, Richard Q.; Simons, Rainee N.

    1993-01-01

    An experimental investigation of bandwidth enhancement of dielectric resonator antennas (DRA) using parasitic elements is reported. Substantial bandwidth enhancement for the HE(sub 11delta) mode of the stacked geometry and for the HE(sub 13delta) mode of the coplanar collinear geometry was demonstrated. Excellent radiation patterns for the HE(sub 11delta) mode were also recorded.

  14. De Novo Genesis of Enhancers in Vertebrates

    PubMed Central

    Eichenlaub, Michael P.; Ettwiller, Laurence

    2011-01-01

    Evolutionary innovation relies partially on changes in gene regulation. While a growing body of evidence demonstrates that such innovation is generated by functional changes or translocation of regulatory elements via mobile genetic elements, the de novo generation of enhancers from non-regulatory/non-mobile sequences has, to our knowledge, not previously been demonstrated. Here we show evidence for the de novo genesis of enhancers in vertebrates. For this, we took advantage of the massive gene loss following the last whole genome duplication in teleosts to systematically identify regions that have lost their coding capacity but retain sequence conservation with mammals. We found that these regions show enhancer activity while the orthologous coding regions have no regulatory activity. These results demonstrate that these enhancers have been de novo generated in fish. By revealing that minor changes in non-regulatory sequences are sufficient to generate new enhancers, our study highlights an important playground for creating new regulatory variability and evolutionary innovation. PMID:22069375

  15. Arousal-Enhanced Location Memory for Pictures

    PubMed Central

    Mather, Mara; Nesmith, Kathryn

    2008-01-01

    Four experiments revealed arousal-enhanced location memory for pictures. After an incidental encoding task, participants were more likely to remember the locations of positive and negative arousing pictures than the locations of non-arousing pictures, indicating better binding of location to picture. This arousal-enhanced binding effect did not have a cost for the binding of nearby pictures to their locations. Thus, arousal can enhance binding of an arousing picture’s content to its location without interfering with picture-location binding for nearby pictures. In addition, arousal-enhanced picture-location memory binding is not just a side effect of enhanced memory for the picture itself, as it occurs both when recognition memory is good and when it is poor. PMID:19190722

  16. Moral enhancement, gnosticism, and some philosophical paradoxes.

    PubMed

    Barilan, Y M

    2015-01-01

    This article examines the concept of moral enhancement from two different perspectives. The first is a bottom-up approach, which aims at identifying fundamental moral traits and subcapacities as targets for enhancement. The second perspective, a top-down approach, is holistic and in line with virtue ethics. Both perspectives lead to the observation that alterations of material and social conditions are the most reliable means to improve prosocial behavior overall. Moral enhancement as a preventive measure invokes Gnostic narratives on the allegedly fallen status of human nature, its search for salvation, and the dependence of the laity on heteronomous salvific interventions. The allure of the preventive kind of enhancement is attributable to its religious hues. Owing to the absence of clarity regarding moral enhancement and of metrics to evaluate its progress, humanity is at risk of prioritizing unclear and unsubstantiated measures of preventive diminishment at the expense of celebrating human capacities and joys. PMID:25473860

  17. Gabor filter based fingerprint image enhancement

    NASA Astrophysics Data System (ADS)

    Wang, Jin-Xiang

    2013-03-01

    Fingerprint recognition technology has become the most reliable biometric technology due to its uniqueness and invariance, which has been most convenient and most reliable technique for personal authentication. The development of Automated Fingerprint Identification System is an urgent need for modern information security. Meanwhile, fingerprint preprocessing algorithm of fingerprint recognition technology has played an important part in Automatic Fingerprint Identification System. This article introduces the general steps in the fingerprint recognition technology, namely the image input, preprocessing, feature recognition, and fingerprint image enhancement. As the key to fingerprint identification technology, fingerprint image enhancement affects the accuracy of the system. It focuses on the characteristics of the fingerprint image, Gabor filters algorithm for fingerprint image enhancement, the theoretical basis of Gabor filters, and demonstration of the filter. The enhancement algorithm for fingerprint image is in the windows XP platform with matlab.65 as a development tool for the demonstration. The result shows that the Gabor filter is effective in fingerprint image enhancement technology.

  18. Helium abundance enhancements in the solar wind

    NASA Technical Reports Server (NTRS)

    Borrini, G.; Gosling, J. T.; Bame, S. J.; Feldman, W. C.

    1982-01-01

    Evidence for a link between helium enhancements at 1 AU and transient coronal mass ejections is provided by the statistical analysis of 73 large helium abundance enhancement observations made by IMPs 6, 7 and 8 over 1972-1978. These events, in which helium abundance enhancement is greater than about 10%, are sporadic, sometimes clustered in time, occur approximately in phase with the solar cycle, and nearly 50% of them are associated with interplanetary shocks and/or geomagnetic activity sudden commencements. The plasma pattern associated with them is nevertheless independent of shock occurrence, and features high magnetic field strength, low alpha-proton velocity difference, and low proton temperature, suggesting that the enhancement is embedded in a closed, magnetically dominated structure that expands adiabatically. Evidence of an association between helium enhancement at 1 AU and type II and IV radio bursts in the corona is presented.

  19. Inflammation-sensitive super enhancers form domains of coordinately regulated enhancer RNAs

    PubMed Central

    Hah, Nasun; Benner, Chris; Chong, Ling-Wa; Yu, Ruth T.; Downes, Michael; Evans, Ronald M.

    2015-01-01

    Enhancers are critical genomic elements that define cellular and functional identity through the spatial and temporal regulation of gene expression. Recent studies suggest that key genes regulating cell type-specific functions reside in enhancer-dense genomic regions (i.e., super enhancers, stretch enhancers). Here we report that enhancer RNAs (eRNAs) identified by global nuclear run-on sequencing are extensively transcribed within super enhancers and are dynamically regulated in response to cellular signaling. Using Toll-like receptor 4 (TLR4) signaling in macrophages as a model system, we find that transcription of super enhancer-associated eRNAs is dynamically induced at most of the key genes driving innate immunity and inflammation. Unexpectedly, genes repressed by TLR4 signaling are also associated with super enhancer domains and accompanied by massive repression of eRNA transcription. Furthermore, we find each super enhancer acts as a single regulatory unit within which eRNA and genic transcripts are coordinately regulated. The key regulatory activity of these domains is further supported by the finding that super enhancer-associated transcription factor binding is twice as likely to be conserved between human and mouse than typical enhancer sites. Our study suggests that transcriptional activities at super enhancers are critical components to understand the dynamic gene regulatory network. PMID:25564661

  20. Nutrient Composition of Enhanced and Non-enhanced Boneless Skinless Chicken Breast Fillets Purchased from Retail

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to compare nutritional composition of raw enhanced (E) and non-enhanced (NE), boneless, skinless chicken breast fillets (pectoralis major), obtained from U.S. retail supermarkets. Fillets were either enhanced with a salt, phosphate, and water solution, or were non-en...

  1. Inflammation-sensitive super enhancers form domains of coordinately regulated enhancer RNAs.

    PubMed

    Hah, Nasun; Benner, Chris; Chong, Ling-Wa; Yu, Ruth T; Downes, Michael; Evans, Ronald M

    2015-01-20

    Enhancers are critical genomic elements that define cellular and functional identity through the spatial and temporal regulation of gene expression. Recent studies suggest that key genes regulating cell type-specific functions reside in enhancer-dense genomic regions (i.e., super enhancers, stretch enhancers). Here we report that enhancer RNAs (eRNAs) identified by global nuclear run-on sequencing are extensively transcribed within super enhancers and are dynamically regulated in response to cellular signaling. Using Toll-like receptor 4 (TLR4) signaling in macrophages as a model system, we find that transcription of super enhancer-associated eRNAs is dynamically induced at most of the key genes driving innate immunity and inflammation. Unexpectedly, genes repressed by TLR4 signaling are also associated with super enhancer domains and accompanied by massive repression of eRNA transcription. Furthermore, we find each super enhancer acts as a single regulatory unit within which eRNA and genic transcripts are coordinately regulated. The key regulatory activity of these domains is further supported by the finding that super enhancer-associated transcription factor binding is twice as likely to be conserved between human and mouse than typical enhancer sites. Our study suggests that transcriptional activities at super enhancers are critical components to understand the dynamic gene regulatory network. PMID:25564661

  2. ELECTROSTATICALLY ENHANCED BARRIER FILTER COLLECTION

    SciTech Connect

    John Erjavec; Michael D. Mann; Ryan Z. Knutson; Michael L. Swanson; Michael E. Collings

    2003-06-01

    This work was performed through the University of North Dakota (UND) Chemical Engineering Department with assistance from UND's Energy & Environmental Research Center. This research was undertaken in response to the U.S. Department of Energy Federal Technology Center Program Solicitation No. DE-PS26-99FT40479, Support of Advanced Coal Research at U.S. Universities and Colleges. Specifically, this research was in support of the UCR Core Program and addressees Topic 1, Improved Hot-Gas Contaminant and Particulate Removal Techniques, introducing an advanced design for particulate removal. Integrated gasification combined cycle (IGCC) offers the potential for very high efficiency and clean electric generation. In IGCC, the product gas from the gasifier needs to be cleaned of particulate matter to avoid erosion and high-temperature corrosion difficulties arising with the turbine blades. Current methods involve cooling the gases to {approx}100 C to condense alkalis and remove sulfur and particulates using conventional scrubber technology. This ''cool'' gas is then directed to a turbine for electric generation. While IGCC has the potential to reach efficiencies of over 50%, the current need to cool the product gas for cleaning prior to firing it in a turbine is keeping IGCC from reaching its full potential. The objective of the current project was to develop a highly reliable particulate collector system that can meet the most stringent turbine requirements and emission standards, can operate at temperatures above 1500 F, is applicable for use with all U.S. coals, is compatible with various sorbent injection schemes for sulfur and alkali control, can be integrated into a variety of configurations for both pressurized gasification and combustion, increases allowable face velocity to reduce filter system capital cost, and is cost-competitive with existing technologies. The collector being developed is a new concept in particulate control called electrostatically enhanced

  3. Experimental evaluation of the twofold electromagnetic enhancement theory of surface-enhanced resonance Raman scattering

    SciTech Connect

    Yoshida, Ken-ichi; Itoh, Tamitake; Biju, Vasudevanpillai; Ishikawa, Mitsuru; Ozaki, Yukihiro

    2009-02-15

    We examined an electromagnetic (EM) theory of surface-enhanced resonance Raman scattering (SERRS) using single Ag nanoaggregates. The SERRS-EM theory is characterized by twofold EM enhancement induced by the coupling of plasmon resonance with both excitation and emission of Raman scattering plus fluorescence. The total emission cross-section spectra of enhanced Raman scattering and enhanced fluorescence were calculated using the following parameters: the spectrum of enhancement factor induced by plasmon resonance, resonance Raman scattering overlapped with fluorescence, and excitation wavelengths. The calculations well agreed with experimental total emission cross-section spectra, thus providing strong indications that the SERRS-EM theory is quantitatively correct.

  4. Carbon dioxide efficiency of terrestrial enhanced weathering.

    PubMed

    Moosdorf, Nils; Renforth, Phil; Hartmann, Jens

    2014-05-01

    Terrestrial enhanced weathering, the spreading of ultramafic silicate rock flour to enhance natural weathering rates, has been suggested as part of a strategy to reduce global atmospheric CO2 levels. We budget potential CO2 sequestration against associated CO2 emissions to assess the net CO2 removal of terrestrial enhanced weathering. We combine global spatial data sets of potential source rocks, transport networks, and application areas with associated CO2 emissions in optimistic and pessimistic scenarios. The results show that the choice of source rocks and material comminution technique dominate the CO2 efficiency of enhanced weathering. CO2 emissions from transport amount to on average 0.5-3% of potentially sequestered CO2. The emissions of material mining and application are negligible. After accounting for all emissions, 0.5-1.0 t CO2 can be sequestered on average per tonne of rock, translating into a unit cost from 1.6 to 9.9 GJ per tonne CO2 sequestered by enhanced weathering. However, to control or reduce atmospheric CO2 concentrations substantially with enhanced weathering would require very large amounts of rock. Before enhanced weathering could be applied on large scales, more research is needed to assess weathering rates, potential side effects, social acceptability, and mechanisms of governance. PMID:24597739

  5. Spectroscopic enhancement in nanoparticles embedded glasses

    NASA Astrophysics Data System (ADS)

    Sahar, M. R.; Ghoshal, S. K.

    2014-09-01

    This presentation provides an overview of the recent progress in the enhancement of the spectroscopic characteristics of the glass embedded with nanoparticles (NPs). Some of our research activities with few significantly new results are highlighted and facilely analyzed. The science and technology dealing with the manipulation of the physical properties of rare earth doped inorganic glasses by embedding metallic NPs or nanoclusters produce the so-called 'nanoglass'. Meanwhile, the spectroscopic enhancement relates the intensity of the luminescence measured at certain transition. The enhancement which expectedly due to the 'plasmonics wave' (referring to the coherent coupling of photons to free electron oscillations called plasmon) occurs at the interface between a conductor and a dielectric. Plasmonics being an emerging concept in advanced optical material of nanophotonics has given this material the ability to exploit the optical response at nanoscale and opened up a new avenue in metal-based glass optics. There is a vast array of plasmonic NPs concepts yet to be explored, with applications spanning solar cells, (bio) sensing, communications, lasers, solid-state lighting, waveguides, imaging, optical data transfer, display and even bio-medicine. Localized surface plasmon resonance (LSPR) can enhance the optical response of nanoglass by orders of magnitude as observed. The luminescence enhancement and surface enhanced Raman scattering (SERS) are new paradigm of research. The enhancement of luminescence due to the influence of metallic NPs is the recurring theme of this paper.

  6. Spectroscopic enhancement in nanoparticles embedded glasses

    SciTech Connect

    Sahar, M. R. Ghoshal, S. K.

    2014-09-25

    This presentation provides an overview of the recent progress in the enhancement of the spectroscopic characteristics of the glass embedded with nanoparticles (NPs). Some of our research activities with few significantly new results are highlighted and facilely analyzed. The science and technology dealing with the manipulation of the physical properties of rare earth doped inorganic glasses by embedding metallic NPs or nanoclusters produce the so-called 'nanoglass'. Meanwhile, the spectroscopic enhancement relates the intensity of the luminescence measured at certain transition. The enhancement which expectedly due to the 'plasmonics wave' (referring to the coherent coupling of photons to free electron oscillations called plasmon) occurs at the interface between a conductor and a dielectric. Plasmonics being an emerging concept in advanced optical material of nanophotonics has given this material the ability to exploit the optical response at nanoscale and opened up a new avenue in metal-based glass optics. There is a vast array of plasmonic NPs concepts yet to be explored, with applications spanning solar cells, (bio) sensing, communications, lasers, solid-state lighting, waveguides, imaging, optical data transfer, display and even bio-medicine. Localized surface plasmon resonance (LSPR) can enhance the optical response of nanoglass by orders of magnitude as observed. The luminescence enhancement and surface enhanced Raman scattering (SERS) are new paradigm of research. The enhancement of luminescence due to the influence of metallic NPs is the recurring theme of this paper.

  7. De-enhancing the dynamic contrast-enhanced breast MRI for robust registration.

    PubMed

    Zheng, Yuanjie; Yu, Jingyi; Kambhamettu, Chandra; Englander, Sarah; Schnall, Mitchell D; Shen, Dinggang

    2007-01-01

    Dynamic enhancement causes serious problems for registration of contrast enhanced breast MRI, due to variable uptakes of agent on different tissues or even same tissues in the breast. We present an iterative optimization algorithm to de-enhance the dynamic contrast-enhanced breast MRI and then register them for avoiding the effects of enhancement on image registration. In particular, the spatially varying enhancements are modeled by a Markov Random Field, and estimated by a locally smooth function with boundaries using a graph cut algorithm. The de-enhanced images are then registered by conventional B-spline based registration algorithm. These two steps benefit from each other and are repeated until the results converge. Experimental results show that our two-step registration algorithm performs much better than conventional mutual information based registration algorithm. Also, the effects of tumor shrinking in the conventional registration algorithms can be effectively avoided by our registration algorithm. PMID:18051148

  8. The inevitability of genetic enhancement technologies.

    PubMed

    Baylis, Francoise; Robert, Jason Scott

    2004-01-01

    We outline a number of ethical objections to genetic technologies aimed at enhancing human capacities and traits. We then argue that, despite the persuasiveness of some of these objections, they are insufficient to stop the development and use of genetic enhancement technologies. We contend that the inevitability of the technologies results from a particular guiding worldview of humans as masters of the human evolutionary future, and conclude that recognising this worldview points to new directions for ethical thinking about genetic enhancement technologies. PMID:15168695

  9. Vessel contrast enhancement in hyperspectral images

    NASA Astrophysics Data System (ADS)

    Bjorgan, Asgeir; Denstedt, Martin; Milanič, Matija; Paluchowski, Lukasz A.; Randeberg, Lise L.

    2015-03-01

    Imaging of vessel structures can be useful for investigation of endothelial function, angiogenesis and hyper-vascularization. This can be challenging for hyperspectral tissue imaging due to photon scattering and absorption in other parts of the tissue. Real-time processing techniques for enhancement of vessel contrast in hyperspectral tissue images were investigated. Wavelet processing and an inverse diffusion model were employed, and compared to band ratio metrics and statistical methods. A multiscale vesselness filter was applied for further enhancement. The results show that vessel structures in hyperspectral images can be enhanced and characterized using a combination of statistical, numerical and more physics informed models.

  10. Enhanced diffusion of phosphorus at grain boundaries

    NASA Technical Reports Server (NTRS)

    Cheng, L. J.; Shyu, C. M.; Stika, K. M.; Daud, T.; Crotty, G. T.

    1982-01-01

    Enhanced diffusion of phosphorus at grain boundaries in cast polycrystalline photovoltaic materials (Wacker, HEM, and Semix) was studied. It was found that the enhancements for the three materials were the same, indicating that the properties of boundaries are similar, even though they were grown by different techniques. In addition, it was observed that grain boundaries capable of enhancing the diffusion always have strong recombination activities. Both phenomena could be related to dangling bonds existing at the boundaries. The present study gives the first evidence that incoherent second order twins of 111/115-plane type are diffusion-active.

  11. Enhancing Rotational Diffusion Using Oscillatory Shear

    NASA Astrophysics Data System (ADS)

    Leahy, Brian D.; Cheng, Xiang; Ong, Desmond C.; Liddell-Watson, Chekesha; Cohen, Itai

    2013-05-01

    Taylor dispersion—shear-induced enhancement of translational diffusion—is an important phenomenon with applications ranging from pharmacology to geology. Through experiments and simulations, we show that rotational diffusion is also enhanced for anisotropic particles in oscillatory shear. This enhancement arises from variations in the particle’s rotation (Jeffery orbit) and depends on the strain amplitude, rate, and particle aspect ratio in a manner that is distinct from the translational diffusion. This separate tunability of translational and rotational diffusion opens the door to new techniques for controlling positions and orientations of suspended anisotropic colloids.

  12. Voltage-gated metal-enhanced fluorescence.

    PubMed

    Zhang, Yongxia; Aslan, Kadir; Geddes, Chris D

    2009-03-01

    We demonstrate the influence of electrical current on the ability of surface plasmons to amplify fluorescence signatures. An applied direct current across Silver Island Films (SIFs) of low electrical resistance perturbs the fluorescence enhancement. For a given applied current, surface plasmons in just-continuous films are sparsely available for fluorophore dipole-coupling and hence the enhanced fluorescence is gated as a function of the applied current. For thicker, low resistance films, sufficient charge carriers are now present in the metal that metal-enhanced fluorescence (MEF) is perturbed to a lesser extent, induced surface plasmons readily formed on the surface by the close-proximity dipole. PMID:19214719

  13. ADVANCED TECHNOLOGIES FOR STRIPPER GAS WELL ENHANCEMENT

    SciTech Connect

    C.M. Boyer II; N.R. Fairchild, Jr.

    2000-04-01

    As part of Task 1 in the Advanced Technologies for Stripper Gas Well Enhancement, Holditch-Reservoir Technologies has partnered with two Appalachian Basin producers, Great Lakes Energy (formerly Range Resources) and Belden & Blake Corporation, to develop methodologies for the identification and enhancement of stripper wells with economic upside potential. The industry partners have provided data for over 700 wells in northwest Pennsylvania. The Task 1 goals of this project are to develop and validate methodologies that can quickly and cost effectively identify wells with enhancement potential. We are currently working with the well data supplied by the industry partners to develop and validate these methodologies.

  14. Enhancement Patterns of Gastric Carcinoma on Contrast-Enhanced Ultrasonography: Relationship with Clinicopathological Features

    PubMed Central

    Wei, Fang; Huang, Pintong; Li, Shiyan; Chen, Jian; Zhang, Ying; Hong, Yurong; Wei, Shumei; Cosgrove, David

    2013-01-01

    The aim of this study was to assess the relationship between the enhancement patterns and clinicopathological features of gastric cancer using intravenous contrast-enhanced ultrasonography (CEUS). In this Ethics Committee-approved prospective study, five hundred fifty two patients with gastric cancer who gave informed consent were examined preoperatively with CEUS. The enhancement pattern of each tumor was analyzed visually. Gross and histopathological findings on the postoperative specimens were compared with the preoperative CEUS findings. The most common CEUS pattern in differentiated gastric cancer was homogeneous enhancement, whereas heterogeneous enhancement was the most common pattern in undifferentiated gastric cancer. The proportion of heterogeneous enhancement was significantly different between the two histological subtypes (Chi- square = 146.735, P<0.001). The sensitivity and specificity of early heterogeneous enhancement on CEUS in diagnosing undifferentiated gastric cancer were 78.84% and 72.59% respectively. Gastric cancers with heterogeneous enhancement were more often Borrmann III and IV macroscopic types than those with homogeneous enhancement (66.56% vs. 30.80%, P<0.001), more commonly T3 and T4 depth of invasion than those with homogeneous enhancement (71.52% vs. 59.60%, P<0.05), more often showed lymphatic invasion than those with homogeneous enhancement (84.44% vs. 76.40%, P<0.05), and were less likely to receive curative gastrectomy than those with homogeneous enhancement (74.83% vs. 86.40%, P<0.005). The intra- and inter-observer reproducibility were both almost perfect for assessing enhancement patterns, with Kappa values of 0.916 (P<0.001) for intra-observer and 0.842 (P<0.001) for inter-observer reproducibility. CEUS provided detailed information about tumor vascularity and contrast enhancement patterns in gastric cancer. CEUS is promising as a new and useful method to predict the histological type of gastric cancer. PMID:24039857

  15. Enhancer Evolution across 20 Mammalian Species

    PubMed Central

    Villar, Diego; Berthelot, Camille; Aldridge, Sarah; Rayner, Tim F.; Lukk, Margus; Pignatelli, Miguel; Park, Thomas J.; Deaville, Robert; Erichsen, Jonathan T.; Jasinska, Anna J.; Turner, James M.A.; Bertelsen, Mads F.; Murchison, Elizabeth P.; Flicek, Paul; Odom, Duncan T.

    2015-01-01

    Summary The mammalian radiation has corresponded with rapid changes in noncoding regions of the genome, but we lack a comprehensive understanding of regulatory evolution in mammals. Here, we track the evolution of promoters and enhancers active in liver across 20 mammalian species from six diverse orders by profiling genomic enrichment of H3K27 acetylation and H3K4 trimethylation. We report that rapid evolution of enhancers is a universal feature of mammalian genomes. Most of the recently evolved enhancers arise from ancestral DNA exaptation, rather than lineage-specific expansions of repeat elements. In contrast, almost all liver promoters are partially or fully conserved across these species. Our data further reveal that recently evolved enhancers can be associated with genes under positive selection, demonstrating the power of this approach for annotating regulatory adaptations in genomic sequences. These results provide important insight into the functional genetics underpinning mammalian regulatory evolution. PMID:25635462

  16. Plasmon resonance enhanced multicolour photodetection by graphene

    PubMed Central

    Liu, Yuan; Cheng, Rui; Liao, Lei; Zhou, Hailong; Bai, Jingwei; Liu, Gang; Liu, Lixin; Huang, Yu; Duan, Xiangfeng

    2012-01-01

    Graphene has the potential for high-speed, wide-band photodetection, but only with very low external quantum efficiency and no spectral selectivity. Here we report a dramatic enhancement of the overall quantum efficiency and spectral selectivity that enables multicolour photodetection, by coupling graphene with plasmonic nanostructures. We show that metallic plasmonic nanostructures can be integrated with graphene photodetectors to greatly enhance the photocurrent and external quantum efficiency by up to 1,500%. Plasmonic nanostructures of variable resonance frequencies selectively amplify the photoresponse of graphene to light of different wavelengths, enabling highly specific detection of multicolours. Being atomically thin, graphene photodetectors effectively exploit the local plasmonic enhancement effect to achieve a significant enhancement factor not normally possible with traditional planar semiconductor materials. PMID:22146398

  17. Natural and enhanced attenuation of metals

    SciTech Connect

    Rouse, J.V.; Pyrih, R.Z.

    1996-12-31

    The ability of natural earthen materials to attenuate the movement of contamination can be quantified in relatively simple geochemical experiments. In addition, the ability of subsurface material to attenuate potential contaminants can be enhanced through modifications to geochemical parameters such as pH or redox conditions. Such enhanced geochemical attenuation has been demonstrated at a number of sites to be a cost-effective alternative to conventional pump and treat operations. This paper describes the natural attenuation reactions which occur in the subsurface, and the way to quantify such attenuation. It also introduces the concept of enhanced geochemical attenuation, wherein naturally-occurring geochemical reactions can be used to achieve in situ fixation. The paper presents examples where such natural and enhanced attenuation have been implemented as a part of an overall remedy.

  18. Antarctic Meteorite Classification and Petrographic Database Enhancements

    NASA Astrophysics Data System (ADS)

    Todd, N. S.; Satterwhite, C. E.; Righter, K.

    2012-03-01

    Describes the Antarctic Meteorite Classification Database and the latest enhancements made to the data acquisition process used to provide updated meteorite data concurrent with the publication of the Antarctic Meteorite Newsletter twice a year.

  19. ENHANCED BIODEGRADATION THROUGH IN-SITU AERATION

    EPA Science Inventory

    This presentation provided an overview of enhanced aerobic bioremediation using in-situ aeration or venting. The following topics were covered: (1) Basic discussion on biodegradation and respiration testing; (2) Basic discussion on volatilization, rate-limited mass transport, an...

  20. Behavioral Therapy, Incentives Enhance Addiction Treatment

    MedlinePlus

    ... Research News From NIH Behavioral Therapy, Incentives Enhance Addiction Treatment Past Issues / Summer 2006 Table of Contents ... that people who are trying to end their addiction to marijuana can benefit from a treatment program ...