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Increased Concentrations (increased + concentration)
Selected AbstractsIncreased Concentration in Banking: Megabanks and Their Implications for Deposit InsuranceFINANCIAL MARKETS, INSTITUTIONS & INSTRUMENTS, Issue 1 2005Kenneth D. Jones During the past two decades, the U.S. banking industry has experienced an unprecedented wave of consolidation, marked by a substantial decline in the number of insured depository institutions and the emergence of banking behemoths with assets totaling in the hundreds of billions of dollars. This unparalleled concentration of assets and deposits among a handful of "megabanks" has important implications for deposit insurance. Most importantly, the Federal Deposit Insurance Corporation (FDIC) now faces a situation in which the failure of even a single megabank could overwhelm the resources immediately available to the deposit insurance system and expose both the banking industry and the government (i.e., taxpayers) to huge potential liabilities. This article highlights the current structure of the banking industry, examines the threat that this structure poses to the deposit insurance funds, and suggests possible approaches for dealing with megabanks and the increasing concentration of insured deposits. [source] C-reactive protein, its role in inflammation, Type 2 diabetes and cardiovascular disease, and the effects of insulin-sensitizing treatment with thiazolidinedionesDIABETIC MEDICINE, Issue 8 2004R. Nesto Abstract Increased concentrations of the marker of inflammation, C-reactive protein (CRP), are associated with insulin resistance, Type 2 diabetes and the development of cardiovascular disease. In particular, inflammation is closely associated with endothelial dysfunction and is recognized as one of the cardiovascular risk factors clustering in the Insulin Resistance Syndrome or Metabolic Syndrome. The exact mechanisms linking insulin resistance and inflammation remain unclear. However, the close association between insulin resistance and inflammation in atherogenesis suggests that therapies that address both parameters may have benefits in reducing diabetes-related macrovascular complications. The thiazolidinedione class of oral anti-diabetic agents are powerful insulin sensitizers that also have anti-inflammatory properties. Treatment with these agents has a range of anti-atherogenic effects, including reduced levels of CRP, plasminogen activator inhibitor-1 (PAI-1), TNF-, and reactive oxygen species. Additionally, the insulin-sensitizing effect of thiazolidinediones improves other factors of the Insulin Resistance Syndrome, including dyslipidaemia and hypertension. Outcome studies are underway to determine if the effects of improving insulin sensitivity and reducing inflammation will translate into clinical benefits and reduce the cardiovascular morbidity and mortality associated with insulin resistance and Type 2 diabetes. [source] Predictors of cardiac events in high-risk patients undergoing emergency surgeryACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 8 2009A. OSCARSSON Background: The aim of this study was to determine the incidence of myocardial damage and left ventricular myocardial dysfunction and their influence on outcome in high-risk patients undergoing non-elective surgery. Methods: In this prospective observational study, 211 patients with American Society of Anesthesiologists classification III or IV undergoing emergent or urgent surgery were included. Troponin I (TnI) was measured pre-operatively, 12 and 48 h post-operatively. Pre-operative N-terminal fragment of B-type natriuretic peptide (NT-proBNP), as a marker for left ventricular systolic dysfunction, was analyzed. The diagnostic thresholds were set to TnI >0.06 ,g/l and NT-proBNP >1800 pg/ml, respectively. Post-operative major adverse cardiac events (MACE), 30-day and 3-months mortality were recorded. Results: Elevated TnI levels were detected in 33% of the patients post-operatively. A TnI elevation increased the risk of MACE (35% vs. 3% in patients with normal TnI levels, P<0.001) and 30-day mortality (23% vs. 7%, P=0.003). Increased concentrations of NT-proBNP were seen in 59% of the patients. Elevated NT-proBNP was an independent predictor of myocardial damage post-operatively, odds ratio, 6.2 [95% confidence interval (CI) 2.1,18.0] and resulted in an increased risk of MACE (21% vs. 2.5% in patients with NT-proBNP ,1800 pg/ml, P<0.001). Conclusion: Myocardial damage is common in a high-risk population undergoing unscheduled surgery. These results suggest a close correlation between myocardial damage in the post-operative period and increased concentration of NT-proBNP before surgery. The combinations of TnI and NT-proBNP are reliable markers for monitoring patients at risk in the peri-operative period as well as useful tools in our risk assessment pre-operatively in emergency surgery. [source] Plasma Asymmetric Dimethylarginine, Symmetric Dimethylarginine, l -Arginine, and Nitrite/Nitrate Concentrations in Cats with Chronic Kidney Disease and HypertensionJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 2 2008R.E. Jepson Background: Chronic kidney disease (CKD) and hypertension have been associated with decreased bioavailability of nitric oxide (NO) and endothelial dysfunction. Increased concentrations of the endothelial nitric oxide synthase (eNOS) inhibitor asymmetric dimethylarginine (ADMA) are implicated. Hypothesis: Plasma ADMA concentration is increased in cats with CKD and systemic hypertension corresponding to a decrease in total plasma nitrate/nitrite (NOx) availability. Decrease in systolic blood pressure (SBP) and proteinuria during treatment of hypertension with amlodipine besylate may be associated with increased NOx availability. Animals: Sixty-nine client-owned normotensive and hypertensive cats with variable azotemia. Methods: Plasma ADMA, symmetric dimethylarginine (SDMA), and l -arginine were measured simultaneously by hydrophilic-interaction liquid chromatography-electrospray tandem mass spectrometry in cats from 6 groups: normotensive nonazotemic (n = 10), normotensive mildly azotemic (n = 10), hypertensive mildly azotemic with hypertensive retinopathy (n = 20), hypertensive mildly azotemic without hypertensive retinopathy (n = 10), normotensive moderately azotemic cats (n = 10), and hypertensive nonazotemic cats (n = 9). Plasma NOx concentrations were measured. Results: A moderate correlation between plasma creatinine and ADMA (n = 69, r= .608, P < .001), SDMA (n = 69, r= .741, P < .001), and NOx concentrations (n = 69, r= .589, P < .001) was observed. There was no association among plasma ADMA, SDMA, and NOx concentrations and SBP. Conclusions and Clinical Importance: Plasma ADMA and SDMA concentrations are increased in cats with CKD and correlate with plasma creatinine concentration. This may imply the presence of endothelial dysfunction in cats with CKD. Plasma ADMA concentrations were not associated with systemic hypertension. Treatment of systemic hypertension with amlodipine besylate did not affect plasma ADMA or NOx concentrations. [source] Increased concentrations of antiangiogenic factors in mirror syndrome complicating twin-to-twin transfusion syndromePRENATAL DIAGNOSIS, Issue 4 2010Dr Federico Prefumo No abstract is available for this article. [source] Adipocytokines, insulin resistance, and coronary atherosclerosis in rheumatoid arthritisARTHRITIS & RHEUMATISM, Issue 5 2010Young Hee Rho Objective The prevalence of subclinical coronary atherosclerosis is increased in patients with rheumatoid arthritis (RA), and the increased risk is associated with insulin resistance. Adipocytokines have been linked to obesity, insulin resistance, inflammation, and coronary heart disease in the general population. This study was undertaken to examine the hypothesis that adipocytokines affect insulin resistance and coronary atherosclerosis among patients with RA. Methods The coronary calcium score, homeostatic model assessment for insulin resistance (HOMA-IR) index, and serum adipocytokine (leptin, adiponectin, resistin, and visfatin) concentrations were determined in 169 patients with RA. The independent effect of each adipocytokine on insulin resistance according to the HOMA-IR index and on coronary artery calcification determined by electron beam computed tomography was assessed in models adjusted for age, race, sex, body mass index (BMI), traditional cardiovascular risk factors, and inflammation mediators. In addition, an interaction analysis was performed to evaluate whether the effect of the HOMA-IR index on the coronary calcium score is moderated by adipocytokines. Results Increased concentrations of leptin were associated with a higher HOMA-IR index, even after adjustment for age, race, sex, BMI, traditional cardiovascular risk factors, and inflammation mediators (P < 0.001), but concentrations of visfatin (P = 0.06), adiponectin (P = 0.55), and resistin (P = 0.98) showed no association with the HOMA-IR index. None of the adipocytokines was independently associated with the coronary calcium score (all P > 0.05). Serum leptin concentrations showed a significant interaction with the HOMA-IR index (P for multivariate interaction = 0.02). Increasing leptin concentrations attenuated the increased risk of coronary calcification related to insulin resistance. Serum concentrations of the other adipocytokines showed no significant interactions with the HOMA-IR index (each P > 0.05). Conclusion Leptin is associated with insulin resistance in patients with RA but, paradoxically, attenuates the effects of insulin resistance on coronary calcification. [source] Ownership Concentration and Corporate Performance on the Budapest Stock Exchange: do too many cooks spoil the goulash?CORPORATE GOVERNANCE, Issue 2 2005John S. Earle We examine the impact of ownership concentration on firm performance using panel data for firms listed on the Budapest Stock Exchange, where ownership tends to be highly concentrated and frequently involves multiple blocks. Fixed-effects estimates imply that the size of the largest block increases profitability and efficiency strongly and monotonically, but the effects of total blockholdings are much smaller and statistically insignificant. Controlling for the size of the largest block, point estimates of the marginal effects of additional blocks are negative. The results suggest that the marginal costs of concentration may outweigh the benefits when the increased concentration involves "too many cooks". [source] Size distributions of suspended particles in open channel flow over bed materialsENVIRONMETRICS, Issue 2 2005B. S. Mazumder Controlled experiments have shown that the grain-size distribution of suspended sediments is related to bed material, flow velocity and height of suspension above the sand bed in an open channel flow. A theoretical model has been developed for computation of suspended grain-size distribution on the basis of continuity equations of sediment and water, using the computed bed-layer concentration as a reference. The proposed model includes the effect of suspension concentration into the mean velocity, turbulent and viscous shear stresses owing to the dynamic coupling between the flow and sediments in suspension. The effect of hindered settling due to the increased concentration in suspension is also taken into account. The model is considered to be a more general one than the existing models, and the results of the present model compare well with the experimental data. Copyright © 2004 John Wiley & Sons, Ltd. [source] Enhanced external counterpulsation improves skin oxygenation and perfusionEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 6 2004M. J. Hilz Abstract Background, Enhanced external counterpulsation (EECP) augments diastolic and reduces systolic blood pressures. Enhanced external counterpulsation has been shown to improve blood flow in various organ systems. Beneficial effects on skin perfusion might allow EECP to be used in patients with skin malperfusion problems. This study was performed to assess acute effects of EECP on superficial skin blood flow, transdermal oxygen and carbon dioxide pressures. Materials and methods, We monitored heart rate, blood pressure, transdermal blood flow as well as oxygen and carbon dioxide pressures in 23 young, healthy persons (28 ± 4 years) and 15 older patients (64 ± 7 years) with coronary artery disease before, during and 3 min after 5 min EECP. Friedman test was used to compare the results of 90-s epochs before, during and after EECP. Significance was set at P < 0·05. Results, Enhanced external counterpulsation increased heart rate and mean blood pressure. During EECP, transdermal oxygen pressure and concentration of moving blood cells increased while transdermal carbon dioxide pressure and velocity of moving blood cells decreased significantly in both groups. After EECP, transdermal carbon dioxide pressure was still reduced while the other parameters returned to baseline values. Conclusions, Improved skin oxygenation and carbon dioxide clearance during EECP seem to result from the increased concentration and reduced flow velocity, i.e. prolonged contact time, of erythrocytes. The increased concentration of moving blood cells and the decreased velocity of moving blood cells at both tested skin sites indicate peripheral vasodilatation. [source] Factors influencing the fatty acid determination in fats and oils using Fourier transform near-infrared spectroscopyEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 9 2007Hormoz Azizian Abstract Fourier transform near-infrared (FT-NIR) technology is matrix dependent and thus highly dependent on factors that influence the absorption spectra. Ignoring these factors during the development of FT-NIR models will affect the accuracy and reliability of the classification of fats and oils and the determination of their fatty acid (FA) composition. Four factors were studied: the temperature at which samples are scanned, differences in FA chain length and number of double bonds, and the presence of non-triacylglycerol components. The results showed that an increase in the recording temperature decreased the absorption peak intensity, but not the position. FT-NIR spectral differences were linked to variations in molecular vibrations resulting from the number of carbon atoms or double bonds in the FA. The FT-NIR method could clearly differentiate between chain lengths from 10:0 to 18:0 and numbers of double bonds from zero (18:0) to three (18:3). Contaminants in triacylglycerols altered the FT-NIR spectra, resulting in increased errors in the FA content. An increased concentration of ,-sitosterol in triolein decreased or increased the observed contents of cis9-18:1 and cis11-18:1, respectively. An FT-NIR model adjusted for the phytosterol content corrected this discrepancy. The revised FT-NIR model was successfully used to provide the accurate FA compositions of commercial sunflower oils. [source] Synthesis of poly(N,N -diethylacrylamide- co -acrylic acid) hydrogels with fast response rate in NaCl mediumJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2008Hongliang Liu Abstract A series of thermo- and pH-sensitive poly (N,N -diethylacrylamide- co -acrylic acid) (P(DEA- co -AA)) hydrogels were prepared in NaCl aqueous solutions with different concentrations. Swelling and deswelling studies showed that in comparison with conventional P(DEA- co -AA) hydrogels (prepared in distilled water), the P(DEA- co -AA) hydrogels thus prepared had almost the same volume phase transition temperature (VPTT), but exhibited much faster response rates as the temperature was raised above their VPTT. Besides, the hydrogels prepared by this method had faster response rates in low pH buffer solutions, and the response rates increased with the increased concentration of the NaCl solutions used during the polymerization. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Determination of the soil organic carbon, nitrogen, available phosphorus and the combined aboveground plant materials in the semi-arid Mbulu District, TanzaniaAFRICAN JOURNAL OF ECOLOGY, Issue 3 2009Mligo Cosmas Abstract Soil of the semi-arid Mbulu District is part of the tropical soils, covered with sparse trees, shrubs or grasses in which domestic grazing animals have prevented the wide spread of vegetation cover. The study aimed at determining soil organic carbon (OC), total nitrogen (N), available phosphorus (P) and the combined aboveground plant materials. Six study sites were established in which soil samples were collected at the depths of 0,5, 6,10 and 11,20 cm. Soil samples were analysed for OC, N and P as well as the levels of N and P in the combined aboveground materials of Panicum coloratum and Hyparrhenia filipendula. The percentage concentrations of OC, N and P were high in the top soil than in the deeper soil horizons. However, analysis of variance showed significant differences of OC in some sites whereas no difference for N and P between soil depth classes. OC was highly related with N and P along soil depth classes. It was concluded that the availability of N and P was because of the decomposition of organic matter in the soil. Soil N and P were highly related with the same in the combined aboveground plant materials. It was concluded that the increased concentration of N and P in the soil resulted into availability of the same in P. coloratum and H. filipendula. There was a very high variation in N and P among sites with different levels of intensity of grazing. It was concluded that grazing animals contributes to the redistribution of soil elements in the rangelands because they graze upon plant parts but the excreta are dropped away from the grazed spot. Résumé Le sol du district semi-aride de Mbulu fait partie de ces sols tropicaux couverts d'arbres, de buissons et d'herbes rares où le pâturage des animaux domestiques a empêché une large dispersion du couvert végétal. L'étude visait à déterminer le carbone organique (CO) du sol, l'azote (N) total, le phosphore (P) disponible et l'ensemble combiné de la matière végétale aérienne. Six sites d'étude furent établis, où l'on a récolté des échantillons de sol à des profondeurs de 0 à 5 cm, 6 à 10 cm, et 11 à 20 cm. Les échantillons de sols ont été analysés pour le CO, le N et le P ainsi que les niveaux de N et de P dans la matière végétale aérienne composée de Panicum coloratum et Hyparrhenia filipendula. Le pourcentage des concentrations de CO, N et P était plus élevé dans la couche supérieure du sol que dans les couches plus profondes. Cependant, une analyse de variance a révélé des différences significatives du CO dans certains sites alors qu'il n'y avait pas de différences pour N ni P aux différentes profondeurs de sol. Le CO était fortement liéà N et à P selon les classes de profondeur. On en a conclu que la disponibilité de N et de P était due à la décomposition de la matière organique dans le sol. Le N et le P du sol étaient fortement liés aux mêmes éléments présents dans la matière végétale aérienne combinée. On a conclu que la concentration accrue de N et de P dans le sol résultait de la concentration de ces mêmes éléments dans P. coloratum et H. filipendula. Il y a avait une très grande variation de N et de P entre des sites où l'intensité de pâturage était différente. On a conclu que les animaux qui pâturent contribuent à la redistribution des éléments du sol dans tous les endroits fréquentés étant donné qu'ils mangent des plantes à certains endroits mais que leurs excréments peuvent être rejetés ailleurs que les zones pâturées. [source] Magnetic resonance imaging and proton MR spectroscopy of the brain in a patient with carbohydrate-deficient glycoprotein syndrome type IJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 6 2003Mayumi Takeuchi MD Abstract This is a report on a case of carbohydrate-deficient glycoprotein syndrome (CDGS) with neurological deficits. Magnetic resonance (MR) images showed remarkable atrophy of the cerebellum and brainstem, and hypointensity was seen in the pallidum on diffusion-weighted images (DWI), suggesting deposits of metal substances. In the cerebellum, proton MR spectroscopy (MRS) showed decreased concentrations of N-acetylaspartate and a complex of glutamine and glutamate (Glx) while the concentration of myo-inositol was increased, indicating neuronal impairment and gliosis. In the parietal lobe, there was an increased concentration of Glx, possibly reflecting dysfunction caused by liver injury. J. Magn. Reson. Imaging 2003;17:722,725. © 2003 Wiley-Liss, Inc. [source] A di(bisphosphonic acid) for protein coupling and targeting to boneJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 11 2004Geeti Bansal Abstract Proteins intended for treatment of bone diseases should ideally exhibit a high bone affinity, so that they are preferentially deposited to bones after systemic administration. This can be achieved by combining molecules having a high affinity to bone with the proteins. Bisphosphonates (BPs) are chemical analogs of pyrophosphate that possess exceptional bone mineral affinity. To this end, we synthesized a novel BP, 3,5-di(ethylamino-2,2-bisphosphono)benzoic acid (6), which contains two BP moieties on a single molecule, unlike conventional BPs that contain one BP moiety per molecule. 6 was then conjugated to two model proteins, bovine serum albumin and nonspecific bovine immunoglobulin G by the carbodiimide chemistry. By varying the reagent concentrations, the conjugation efficiency (i.e., number of 6 per protein) was readily controlled under the experimental conditions. The protein- 6 conjugates exhibited an in vitro mineral affinity that was proportional to the number of conjugated 6. The 6 -conjugates of both bovine serum albumin and immunoglobulin G were found to be bone seeking in rats, based on the increased concentration of 6 -conjugated proteins in bone tissue after intravenous administration. We conclude that the novel BP synthesized (6) can serve as a carrier for bone delivery while reducing the extent of protein modification necessary for bone targeting. © 2004 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 93:2788,2799, 2004 [source] Mycorrhization of coriander (Coriandrum sativum L) to enhance the concentration and quality of essential oilJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 4 2002Rupam Kapoor Abstract The effect of association of two vesicular arbuscular mycorrhizal (VAM) fungi, Glomus macrocarpum and G fasciculatum, on the concentration and composition of essential oil in coriander (Coriandrum sativum) was studied. VAM inoculation increased the essential oil concentration in fruits by as much as 43%. Although significant variation in effectiveness of the two fungal species was observed, the quality of essential oil was significantly enhanced on mycorrhization. GC characterisation of essential oil showed increased concentration of geraniol and linalool in plants inoculated with G macrocarpum and G fasciculatum respectively. © 2002 Society of Chemical Industry [source] Iron limitation induces SpoT-dependent accumulation of ppGpp in Escherichia coliMOLECULAR MICROBIOLOGY, Issue 4 2005Daniel Vinella Summary In Escherichia coli the ,-lactam mecillinam specifically inhibits penicillin-binding protein 2 (PBP2), a peptidoglycan transpeptidase essential for maintaining rod shape. We have previously shown that PBP2 inactivation, results, in, a, cell, division, block, and, that an increased concentration of the nucleotide ppGpp, effector of the RelA-dependent stringent response, confers mecillinam resistance and allows cells to divide as spheres in the absence of PBP2 activity. In this study we have characterized an insertion mutation which confers mecillinam resistance in wild-type and ,relA strains but not in ,relA,spoT strains, devoid of ppGpp. The mutant has an insertion in the fes gene, coding for enterochelin esterase. This cytoplasmic enzyme hydrolyses enterochelin,Fe3+ complexes, making the scavenged iron available to the cells. We show that inactivation of the fes gene causes iron limitation on rich medium plates and a parallel SpoT-dependent increase of the ppGpp pool, as judged by the induction of the iron-regulated fiu::lacZ fusion and the repression of the stringently controlled P1rrnB::lacZ fusion respectively. We further show, by direct ppGpp assays, that iron starvation in liquid medium produces a SpoT-dependent increase of the ppGpp pool, strongly suggesting a role for iron in the balance of the two activities of SpoT, synthesis and hydrolysis of (p)ppGpp. Finally, we present evidence that ppGpp exerts direct or indirect positive control on iron uptake, suggesting a simple homeostatic regulatory circuit: iron limitation leads to an increased ppGpp pool, which increases the expression of iron uptake genes, thereby alleviating the limitation. [source] Total body exposure to ultraviolet radiation does not influence plasma levels of immunoreactive ,-endorphin in manPHOTODERMATOLOGY, PHOTOIMMUNOLOGY & PHOTOMEDICINE, Issue 6 2001Marjolein Wintzen Background/Aims: A growing number of reports support evidence of proopiomelanocortin (POMC)-derived peptides in human skin cells, although not consistently. Also the effect of ultraviolet radiation (UVR) on cutaneous and plasma levels of these POMC peptides has not been established unequivocally. We hypothesized that production of ,-endorphin (,E) may explain the sense of well-being many people experience when sun-bathing. The aim of the present study was to investigate whether exposure of the skin to UVR elevates plasma ,E. Method: Healthy volunteers (n=26) received a single, weighted dose of 15 J/cm2 of UVA. Several times during the hour following irradiation, plasma ,E- immunoreactivity (,E-IR) was determined by radioimmunoassay. The effect of repeated exposure wasassessed in 35 patients treated with UVB, UVA, or UVA-1. Plasma ACTH-IR was monitored in parallel. Results: Overall, plasma levels of ,E-IR and ACTH-IR showed no significant changes during the experiment, indicating that these peptides are not influenced by single or repeated exposures to UVR of different wavelengths. Conclusion: On the basis of these results, the skin does not appear to contribute significantly to the levels of circulating ,E or ACTH. These data offer no support for the hypothesis that exposure to UVR leads to an increased concentration of circulating ,E, which could contribute to the feeling of well-being that often accompanies sun-bathing. [source] Would transformation of C3 crop plants with foreign Rubisco increase productivity?PLANT CELL & ENVIRONMENT, Issue 2 2004A computational analysis extrapolating from kinetic properties to canopy photosynthesis ABSTRACT Genetic modification of Rubisco to increase the specificity for CO2 relative to O2 (,) would decrease photorespiration and in principle should increase crop productivity. When the kinetic properties of Rubisco from different photosynthetic organisms are compared, it appears that forms with high , have low maximum catalytic rates of carboxylation per active site (kcc). If it is assumed that an inverse relationship between kcc and , exists, as implied from measurements, and that an increased concentration of Rubisco per unit leaf area is not possible, will increasing , result in increased leaf and canopy photosynthesis? A steady-state biochemical model for leaf photosynthesis was coupled to a canopy biophysical microclimate model and used to explore this question. C3 photosynthetic CO2 uptake rate (A) is either limited by the maximum rate of Rubisco activity (Vcmax) or by the rate of regeneration of ribulose-1,5-bisphosphate, in turn determined by the rate of whole chain electron transport (J). Thus, if J is limiting, an increase in , will increase net CO2 uptake because more products of the electron transport chain will be partitioned away from photorespiration into photosynthesis. The effect of an increase in , on Rubisco-limited photosynthesis depends on both kcc and the concentration of CO2 ([CO2]). Assuming a strict inverse relationship between kcc and ,, the simulations showed that a decrease, not an increase, in , increases Rubisco-limited photosynthesis at the current atmospheric [CO2], but the increase is observed only in high light. In crop canopies, significant amounts of both light-limited and light-saturated photosynthesis contribute to total crop carbon gain. For canopies, the present average , found in C3 terrestrial plants is supra-optimal for the present atmospheric [CO2] of 370 µmol mol,1, but would be optimal for a CO2 concentration of around 200 µmol mol,1, a value close to the average of the last 400 000 years. Replacing the average Rubisco of terrestrial C3 plants with one having a lower and optimal , would increase canopy carbon gain by 3%. Because there are significant deviations from the strict inverse relationship between kcc and ,, the canopy model was also used to compare the rates of canopy photosynthesis for several Rubiscos with well-defined kinetic constants. These simulations suggest that very substantial increases (> 25%) in crop carbon gain could result if specific Rubiscos having either a higher , or higher kcc were successfully expressed in C3 plants. [source] Conformational changes in ,-endorphin as studied by electrospray ionization mass spectrometry,RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 23 2001Hui Lin Because of a wide range of physiological functions, the structure of ,-endorphin (BE) is of great interest. In this study, conformational changes in BE induced by methanol are explored with electrospray ionization-mass spectrometry (ESI-MS). Differences in the charge-state distribution (CSD) and the extent of hydrogen/deuterium (H/D) exchange were used to monitor the conformational changes. The latter experiments were conducted via time-resolved ESI-MS in a continuous-flow apparatus. Both these techniques demonstrate that BE exists in a random coil open structure in aqueous media, but it acquires a more compact conformation with increased concentration of methanol. The H/D exchange experiments reveal that BE forms 61% ,-helix in mixed solvents. Copyright © 2001 John Wiley & Sons, Ltd. [source] Protein quality of larval feed with increased concentration of hydrolysed protein: effects of heat treatment and leachingAQUACULTURE NUTRITION, Issue 5 2009A. NORDGREEN Abstract Four heat coagulated early weaning diets with increasing concentrations of pepsin hydrolysed protein, were investigated with regard to the change in protein quality during feed production and exposure to leaching. Water-soluble N, trichloroacetic acid-soluble N and amino acid (AA) profiles were determined in finished diets and in diets leached for 6 min. In vitro diet digestibility was measured and related to increasing inclusion of hydrolysed protein and N leakage. Seventeen to 47% of soluble N in the feed ingredients was made insoluble by heat denaturation during feed production, but the concentration of peptides and free amino acids (FAA) were not influenced. All peptides/FAA and 70,80% of water-soluble protein were lost after exposure to leaching. Increased inclusion of hydrolysed protein increased the loss of crude protein (15,30%). All taurine and 30% of histidine was lost during leaching, no other major changes in AA profile were found. There was no difference in digestibility between diets exposed to leaching. However, leached diets showed reduced digestibility as compared to diets that had not been exposed to leaching. In conclusion micro-bound type diets as used in this study have a low efficiency in delivering soluble N to fish larvae and should be carefully considered for this purpose. [source] Swimming characteristics of magnetic bacterium, Magnetospirillum sp.BIOTECHNOLOGY & BIOENGINEERING, Issue 1 2001AMB-, implications as toxicity measurement Abstract To develop a novel toxicity measurement system using the persistent swimming property of magnetic bacteria along an externally applied magnetic field, certain characteristics of Magnetospirillum sp. AMB-1 cells were examined, including their growth pattern, motility, magnetosensitivity, swimming speed, and cell length distribution. In addition, the effect of toxic compounds on the swimming speed was assessed relative to application as a toxicity sensor. With an inoculum of 1.0 × 108 cells/mL, the cells reached the stationary phase with a concentration of about 5 × 108 cells/mL after 20 h, under both aerobic and anaerobic conditions. The distribution of the cell length did not vary significantly during the growth period, and both aerobically and anaerobically growing cells showed a similar cell length distribution. Although the cells showed similar growth patterns under both conditions, the anaerobically grown cells exhibited higher motility and magnetosensitivity. Actively growing cells under anaerobic conditions had an average swimming speed of 49 ,m/s with a standard deviation of 20 ,m/s. When the anaerobically growing cells were exposed to various concentrations of toxic compounds, such as 1-propanol and acetone, the swimming speed decreased with an increased concentration of the toxic compound. Accordingly, the relationship between swimming speed and toxicity can be used as an effective quantitative toxicity measurement; furthermore, the relative sensitivity of the proposed system was comparable to Microtox, which is commercially available. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 76: 11,16, 2001. [source] The Role of Ion Pairs in the Second-Order NLO Response of 4-X-1-Methylpiridinium Salts,CHEMPHYSCHEM, Issue 2 2010Francesca Tessore Dr. Abstract A series of 4-X-1-methylpyridinium cationic nonlinear optical (NLO) chromophores (X=(E)-CHCHC6H5; (E)-CHCHC6H4 -4,-C(CH3)3; (E)-CHCHC6H4 -4,-N(CH3)2; (E)-CHCHC6H4 -4,-N(C4H9)2; (E,E)-(CHCH)2C6H4 -4,-N(CH3)2) with various organic (CF3SO3,, p -CH3C6H4SO3,), inorganic (I,, ClO4,, SCN,, [Hg2I6]2,) and organometallic (cis -[Ir(CO)2I2],) counter anions are studied with the aim of investigating the role of ion pairing and of ionic dissociation or aggregation of ion pairs in controlling their second-order NLO response in anhydrous chloroform solution. The combined use of electronic absorption spectra, conductimetric measurements and pulsed field gradient spin echo (PGSE) NMR experiments show that the second-order NLO response, investigated by the electric-field-induced second harmonic generation (EFISH) technique, of the salts of the cationic NLO chromophores strongly depends upon the nature of the counter anion and concentration. The ion pairs are the major species at concentration around 10,3,M, and their dipole moments were determined. Generally, below 5×10,4,M, ion pairs start to dissociate into ions with parallel increase of the second-order NLO response, due to the increased concentration of purely cationic NLO chromophores with improved NLO response. At concentration higher than 10,3,M, some multipolar aggregates, probably of H type, are formed, with parallel slight decrease of the second-order NLO response. Ion pairing is dependent upon the nature of the counter anion and on the electronic structure of the cationic NLO chromophore. It is very strong for the thiocyanate anion in particular and, albeit to a lesser extent, for the sulfonated anions. The latter show increased tendency to self-aggregate. [source] In vitro determination of active bile acid absorption in small biopsy specimens obtained endoscopically or surgically from the human intestineEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 2 2002K-A. Ung Abstract Background In the construction of a Kock reservoir for continent urinary diversion, 70 cm of the distal ileum are used. Impaired absorption of bile acids in these patients might cause diarrhoea. Data on the absorption of bile acids in different parts of the human intestine are limited. Methods Biopsies were taken during endoscopy from the duodenum, the terminal ileum or the right colon, and during surgery 10, 50, 100 and 150 cm proximally to the ileo-caecal valve using standard endoscopy biopsy forceps. The biopsy specimens were incubated in vitro with radio-labelled taurocholic acid at 37 °C for 22 or 45 min The radioactivity was determined using the liquid scintillation technique. Results A linear increase in the uptake was observed, with increased concentrations of taurocholic acid between 100 and 500 µm in all specimens tested, that represented passive uptake or unspecific binding. The active uptake could be calculated from the intercept of the line representing passive uptake with the ordinate. The active uptake in the terminal ileum was 3,4 times greater than 100 cm proximal to the valve. Conclusions The active absorption of bile acids in humans can be determined in small biopsy specimens taken using standard biopsy forceps during endoscopy or surgery. This method is suitable for clinical studies of bile acid absorption. Active uptake of bile acids not only takes place in the very distal part of the ileum but also to a considerable degree 100 cm proximally to the ileo-colonic valve. This should be taken into account when selecting the ileal segment for continent urinary diversion. [source] Effects of continuous or rotational grazing of two perennial ryegrass varieties on the chemical composition of the herbage and the performance of finishing lambsGRASS & FORAGE SCIENCE, Issue 3 2007C. L. Marley Abstract Plant breeding has developed perennial ryegrass varieties with increased concentrations of water-soluble carbohydrates (WSCs) compared with conventional varieties. Water-soluble carbohydrates are major metabolic and storage components in ryegrass. Therefore, if perennial ryegrass herbage is allowed to grow to greater heights it should contain higher water-soluble carbohydrates concentrations, for example as under rotational grazing rather than continuous grazing by livestock. This study investigated this hypothesis and measured the performance of lambs grazed rotationally and continuously. Replicated plots of the variety AberDart (bred to express high WSC concentrations) or the variety Fennema were grazed by a core group of ten male Cheviot lambs for 10 weeks. Lambs were weighed and replicate forage samples were taken every 7 d. Concentrations of WSC in AberDart herbage were significantly (P < 0·05), but not substantially, higher than those in Fennema herbage. Rotational grazing did not increase the differential in WSC concentration between the AberDart and Fennema varieties. However, there was a tendency (P = 0·07) for lambs rotationally grazing the AberDart swards to have a higher final live weight than lambs grazing the Fennema swards. Overall, lamb performance was increased when either perennial ryegrass variety was rotationally rather than continuously grazed (P < 0·001). [source] Homocysteine induces metalloproteinase and shedding of ,-1 integrin in microvessel endothelial cells,JOURNAL OF CELLULAR BIOCHEMISTRY, Issue 1 2004Suresh Shastry Abstract Although studies have suggested microvessel endothelial cells (MVEC) activation and induction of matrix metalloproteinases (MMPs) by homocysteine (Hcy), the transduction mechanism leading to endothelial activation was unclear. We hypothesized that Hcy induced metalloproteinase and altered the levels of integrin in MVEC. MVEC from mouse brain were isolated and characterized by CD-31 (PECAM-1) FITC labeling. The MVEC were activated with different doses (6,40 ,M) of Hcy. The cultured-conditioned-medium was analyzed for MMP activity by gelatin gel-zymography. TIMP-1, -4, ,-1 integrin, and a disintegrin and metalloproteinase-12 (ADAM-12) were quantified by Western blot analysis. We used MVEC in cell culture to study the effect of increasing concentrations of Hcy upon the secretion of various proteins into the culture medium. MMP-9, ,-1 integrin, ADAM-12, and TIMP-1 were found in increased concentrations in the culture medium of Hcy-treated cells whereas TIMP-4 was decreased. We have shown that purified TIMP-4 blocked the increase of ,-1 integrin shedding in Hcy-treated cells. Interestingly, our results suggest that TIMP-1 and TIMP-4 function antagonistically in Hcy-induced signaling pathways. © 2004 Wiley-Liss, Inc. [source] Quantitative PCR determination of human cytomegalovirus in blood cellsJOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 3 2001J. Satou Abstract We evaluated a rapid and sensitive method to determine human cytomegalovirus (CMV) DNA levels in blood cells using a quantitative polymerase chain reaction (PCR) technique. This method is based on real-time detection of PCR using a dual fluorescence-labeled probe and a sequence detector. Ten copies of CMV DNA were detected, when 1 ,g of DNA from blood samples was used with this method, and a good correlation was obtained between increased concentrations of copy numbers calculated and measured copy numbers of CMV DNA (r = 0.999). Forty normal subjects exhibited no copies of CMV DNA. On the other hand, a 6-month-old girl tested positive for increased levels 4 weeks after liver transplant. This method is simple, accurate, and sensitive for the quantitative detection of CMV DNA in vivo, indicating possible applications for the diagnosis and monitoring of CMV infection. J. Clin. Lab. Anal. 15:122,126, 2001. © 2001 Wiley-Liss, Inc. [source] UTILIZATION OF APRICOT KERNEL FLOUR AS FAT REPLACER IN COOKIESJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 1 2010I.T. SEKER ABSTRACT In this study, shortening content in a wire-cut cookie formulation was reduced at 10, 20, 30 and 40% and replaced with apricot kernel flour (AKF). The effects of increased concentrations of AKF on the properties of cookies were investigated. Protein, fat and total dietary fiber (TDF) contents of the apricot kernels were determined as 21.8%, 40.2% and 35.8%, respectively, which confirmed that the apricot kernel is an important source of dietary protein as well as oil and fiber. Addition of AKF decreased the spread ratio and increased the hardness of the cookies (P , 0.01). However, sensory evaluation revealed that the cookies containing AKF were acceptable to the panelists at all concentrations (P , 0.01). TDF contents of the cookies increased significantly (P , 0.01) as the AKF supplemention increased. AKF is a suitable replacer of shortening in cookies at 10 and 20%. PRACTICAL APPLICATIONS Province of Malatya (Turkey) is one of the major apricot and apricot kernel producing regions in the world. Apricot kernels are generally exported and the importing countries use it especially in the production of oil, benzaldehyde, cosmetics, active carbon and aroma. Apricot kernels are also utilized in retail bakeries and consumed as appetizers. Cookies are one of the most popular bakery products and textural characteristics of cookies are highly influenced by their fat content. Health specialists recommend that daily fat consumption should not exceed 30% of the total calories in a diet. In this study, the preparation of apricot kernel flour (AKF), which does not require much processing and has the advantage of including other nutrients, was achieved. With the production of high-fiber and low-fat cookies by the usage of AKF, an exciting new potential as a food ingredient, especially in cereal products, is offered. [source] Perceived Creaminess and Viscosity of Aggregated Particles of Casein Micelles and ,-CarrageenanJOURNAL OF FOOD SCIENCE, Issue 5 2010Kelly L. Flett Abstract:, Creaminess, in terms of sensory science, is a very complex and multifaceted term. It is a descriptor often reserved for fat-containing dairy emulsions, however, has also been used to describe nondairy food emulsions. In the food industry, it is a great challenge to decrease fat content while maintaining the original quality and sensory characteristics of a food product. An aggregated particle consisting of casein micelles and ,-carrageenan has the potential to enhance the perceived creaminess of a low-fat food product, due to its colloidal size. In this study, these aggregates were incorporated into nonfat dairy beverages and subjected to sensory studies. In the 1st sensory study, the aggregates, either as a powdered ingredient or a fresh ingredient, were added to thickened dairy beverages and compared to similar beverages containing skim milk powder and either no fat or 2% dairy fat. The panelists found the aggregate-containing beverages to be creamier and more viscous in comparison to the control beverages. In the 2nd sensory study, fresh and powdered aggregates, at 2 concentrations, were added to a sweetened nonfat dairy beverage and compared to a similar beverage containing 2% dairy fat. The results of this panel showed that aggregates, especially at increased concentrations, were perceived as more creamy than the fat-containing beverage. Panelists described the creaminess of the aggregates as more thick and viscous while the dairy fat was described more in terms of mouth-coating. Thus, we have developed a nonfat milk ingredient that can contribute creaminess to a food product. Practical Application:, This study shows potential applications of aggregates of casein micelles and ,-carrageenan as a fat-mimetic or creaminess-enhancing ingredient. These particles may be produced as either fresh aggregates directly formed in a dairy product or as powdered aggregates added to dairy or nondairy products. [source] Coagulation dynamics and platelet functions in obstructive jaundiced patientsJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 5 2009Tebessüm Çak Abstract Background:, All of the body systems are affected by increased levels of bilirubin. The aim of this study is to investigate the function of platelets and clotting dynamics in patients with obstructive jaundice. Methods:, Liver function tests, serum CRP, PT, PTT and hemogram were measured in 23 patients with obstructive jaundice. Thromboelastography (TEG) was done for the evaluation of coagulation dynamics, while platelet function assay (PFA 100) was used to evaluate platelet functions. Blood samples were obtained at two occasions, before the drainage and 3 weeks after the relief of the obstruction. Results:, Hypercoagulation was detected in 80% of patients. Maximum strength, elasticity, coagulation indices of the clot were correlated with increased concentrations of direct bilirubin. Although maximum strength of coagulum usually represents increased activity of platelet function, membrane closure times with PFA 100 were found to be prolonged in 30% of patients, reduced values were determined in 17% of patients. No demonstrable effect on coagulation parameters and platelet function were detected after drainage procedures regardless of modality. Conclusions:, Even though there is a general assumption about the increased bleeding tendency in obstructive jaundiced patients, we could not demonstrate reduced clotting activity by measuring with either PFA or TEG. On the contrary we observed tendency for hypercoagulation independent of increased prothrombin times. The most probable cause of this effect is the increased activity of fibrin polymers on platelet membrane. [source] Mass transport and thermodynamic analysis of PAHs in partitioning systems in the presence and absence of ultrasonicationAICHE JOURNAL, Issue 10 2010Pedro A. Isaza Abstract Transport of PAHs from Desmopan polymers to methanol under various mixing conditions and in the presence of ultrasound was analyzed. PAH transport was influenced by external transport resistances; however, agitation greater than 800 rpm yielded PAH transport completely limited by internal resistances. Delivery rates of phenanthrene, fluoranthene, and pyrene with ultrasonication were faster than that under any mixing condition, suggesting enhanced internal transport properties. Ultrasound also induced increased concentrations of PAHs in solution at equilibrium. The model developed described PAH delivery under sonicated/non-sonicated conditions, while quantifying diffusive and thermodynamic properties. Diffusivities with and without ultrasound decreased with permeant molecular size agreeing with coefficients determined for similar aromatic compounds in polymers. Partitioning coefficients under sonicated and non-sonicated conditions conclusively differed from each other and decreased as a function of PAH molecular size. Quantitative structure-property relationship data of PAHs yielded factors predicting thermodynamic and transport behaviors, with polarizability being the best descriptor. © 2010 American Institute of Chemical Engineers AIChE J, 2010 [source] | |||||||||||||||||||||||||