bluuebunny/crossref_metadata_2025_split huggingface dataset:
WENO-TVD schemes for hyperbolic conservation laws
Authors: Zahran Yousef Hashem 
Published: July 2007

The purpose of this paper is twofold. Firstly we carry out a modification of the finite volume WENO (weighted essentially non-oscillatory) scheme of Titarev and Toro [14] and [15].This modification is done by using two fluxes as building blocks in spatially fifth order WENO schemes instead of the second order TVD flux proposed by Titarev and Toro [14] and [15]. These fluxes are the second order TVD flux [19] and the third order TVD flux [20].Secondly, we propose to use these fluxes as a building block in spatially seventh order WENO schemes. The numerical solution is advanced in time by the third order TVD Runge–Kutta method. A way to extend these schemes to general systems of nonlinear hyperbolic conservation laws, in one and two dimension is presented. Systematic assessment of the proposed schemes shows substantial gains in accuracy and better resolution of discontinuities, particularly for problems involving long time evolution containing both smooth and non-smooth features.
Cold Summer Temperature Limits Recruitment of Age‐0 Cutthroat Trout in High‐Elevation Colorado Streams
Authors: Coleman Mark A. , Fausch Kurt D. 
Published: July 2007

AbstractTranslocation is a key strategy for conserving native subspecies of cutthroat trout Oncorhynchus clarkii that have declined markedly throughout their native range. Previous research showed that successful translocations of cutthroat trout in high‐elevation southern Rocky Mountain streams were more likely in streams with warm summer water temperature and led to the hypothesis that cold summer temperatures govern translocation success by limiting recruitment. We tested this by measuring the density and size of age‐0 cutthroat trout (greenback cutthroat trout O. c. stomias and Colorado River cutthroat trout O. c. pleuriticus) in six headwater streams in north‐central Colorado that varied in thermal characteristics. Surveys were conducted at peak emergence during 3 years in two widely spaced study reaches in each stream. Fry density increased with Celsius degree‐days accumulated during the growing season but did not vary significantly among years. We used laboratory data on the growth and survivorship of age‐0 cutthroat trout in three temperature regimes that were similar to those studied in the field to determine expected survivorship and size of fry at the start of winter, which occurred several weeks after peak emergence in our warmer reaches and coincided with emergence in colder reaches. Our results support the hypothesis that recruitment of native cutthroat trout in Colorado is limited by cold water temperatures that reduce growth and recruitment. High‐elevation streams, like those studied, that accumulate 900‐1,200 Celsius degree‐days during the growing season afford the best opportunity for cutthroat trout recruitment and translocation success. Streams that provide 800‐900 degree‐days probably sustain recruitment in some years, and those with less than 800 degree‐days are generally unsuitable for translocations because of a greater risk of recruitment failure and the smaller sizes attained by fry by the onset of winter.
Winter Feeding Success of Stream Trout under Different Streamflow and Turbidity Conditions
Authors: White Jason L. , Harvey Bret C. 
Published: July 2007

AbstractTo investigate the relationship between turbidity and trout feeding success in natural systems, we sampled the stomach contents of resident rainbow trout Oncorhynchus mykiss and coastal cutthroat trout O. clarkii clarkii under different streamflow and turbidity conditions during winter in two northwestern California streams (total sample size = 161). Feeding success generally did not differ sharply for fish collected under low versus high streamflow and turbidity conditions. Bioenergetics modeling suggested that feeding success on average did not reach maintenance levels for seven of eight sets of samples, but extensive feeding on oligochaetes during one period of elevated streamflow resulted in positive energy balances. Occasional peaks in food intake could greatly influence the energy budgets and growth of trout in mild‐winter systems. Under some natural conditions, trout appear able to achieve relatively high feeding success when turbidity limits visibility.
Pedigreed Primate Embryonic Stem Cells Express Homogeneous Familial Gene Profiles
Authors: Navara Christopher S. , Mich-Basso Jocelyn D. , Redinger Carrie J. , Ben-Yehudah Ahmi , Jacoby Ethan , Kovkarova-Naumovski Elizabeta , Sukhwani Meena , Orwig Kyle , Kaminski Naftali , Castro Carlos A. , Simerly Calvin R. , Schatten Gerald 
Published: July 2007

Abstract
Human embryonic stem cells (hESCs) hold great biomedical promise, but experiments comparing them produce heterogeneous results, raising concerns regarding their reliability and utility, although these variations may result from their disparate and anonymous origins. To determine whether primate ESCs have intrinsic biological limitations compared with mouse ESCs, we examined expression profiles and pluripotency of newly established nonhuman primate ESC (nhpESCs). Ten pedigreed nhpESC lines, seven full siblings (fraternal quadruplets and fraternal triplets), and nine half siblings were derived from 41 rhesus embryos; derivation success correlated with embryo quality. Each line has been growing continuously for ∼1 year with stable diploid karyotype (except for one stable trisomy) and expresses in vitro pluripotency markers, and eight have already formed teratomas. Unlike the heterogeneous gene expression profiles found among hESCs, these nhpESCs display remarkably homogeneous profiles (&gt;97%), with full-sibling lines nearly identical (&gt;98.2%). Female nhpESCs express genes distinct from their brother lines; these sensitive analyses are enabled because of the very low background differences. Experimental comparisons among these primate ESCs may prove more reliable than currently available hESCs, since they are akin to inbred mouse strains in which genetic variables are also nearly eliminated. Finally, contrasting the biological similarities among these lines with the heterogeneous hESCs might suggest that additional, more uniform hESC lines are justified. Taken together, pedigreed primate ESCs display homogeneous and reliable expression profiles. These similarities to mouse ESCs suggest that heterogeneities found among hESCs likely result from their disparate origins rather than intrinsic biological limitations with primate embryonic stem cells.
Disclosure of potential conflicts of interest is found at the end of this article.
Synthesis and photochromic behavior of some azo-polysiloxanes modified with nucleobases or donor-acceptor groups
Authors: Enea Ramona , Resmeriţă Ana-Maria , Petraru Laura , Grigoraş Cristian , Scutaru Dan , Simionescu Cristofor , Hurduc Nicolae 
Published: July 2007

AbstractThis paper presents the syntheses, characterization and photochromic behavior of some new azo-polysiloxanes modified with uracil, cytosine or nitro-phenolic groups. Taking into consideration the possibility of generating H-bonds or donor/acceptor interactions, this class of materials present a potential applicability in the immobilization of biomolecules and their nano-manipulations. Also, such compounds are capable of producing a fluid phase, with directional flowing capacity. For all these polymers, the molecular modeling simulations have shown disordered structures, which would generate amorphous phases, a very important aspect for molecules’ nano-manipulation. The photochromic behavior in the presence of UV irradiation was also evaluated.
The endothelium and vascular inflammation in diabetes
Authors: Hartge Martin M , Unger Thomas , Kintscher Ulrich 
Published: July 2007

The endothelium releases multiple mediators, not only regulators of vasomotor function but also important physiological and pathophysiological inflammatory mediators. Endothelial dysfunction is caused by chronic exposure to various stressors such as oxidative stress and modified low-density lipoprotein (LDL) cholesterol, resulting in impaired nitric oxide (NO) production and chronic inflammation. Biomechanical forces on the endothelium, including low shear stress from disturbed blood flow and hypertension, are also important causes of endothelial dysfunction. These processes seem to be augmented in patients with Diabetes. In states of insulin resistance and in type 2 Diabetes insulin signalling is impaired. Increased vascular inflammation, including enhanced expression of inter-leukin-6 (IL-6), vascular cellular adhesion molecule-1 (VCAM-1) and monocyte chemoattractant protein (MCP-1) are observed, as is a marked decrease in NO bioavail-ability. Furthermore, hyperglycaemia leads to increased formation of advanced glycation end products (AGE), which quench NO and impair endothelial function. In summary, during the development of diabetes a number of biochemical and mechanical factors converge on the endothelium, resulting in endothelial dysfunction and vascular inflammation. In the presence of insulin resistance, these processes are potentiated and they provide a basis for the macrovascular disease seen in diabetes.
Therapeutic regulation of endothelial dysfunction in type 2 diabetes mellitus
Authors: Hamilton Sandra J , Chew Gerard T , Watts Gerald F 
Published: July 2007

Endothelial dysfunction is universal in diabetes, being intimately involved with the development of cardiovascular disease. The pathogenesis of endothelial dysfunction in diabetes is complex. It is initially related to the effects of fatty acids and insulin resistance on ‘uncoupling’ of both endothelial nitric oxide synthase activity and mitochondrial function. Oxidative stress activates protein kinase C (PKC), polyol, hexosamine and nuclear factor kappa B pathways, thereby aggravating endothelial dysfunction. Improvements in endothelial function in the peripheral circulation in diabetes have been demonstrated with monotherapies, including statins, fibrates, angiotensin-converting enzyme (ACE) inhibitors, metformin and fish oils. These observations are supported by large clinical end point trials. Other studies show benefits with certain antioxidants, L-arginine, folate, PKC-inhibitors, peroxi-some proliferator activated receptor (PPAR)-α and -γ agonists and phosphodiesterase (PDE-5) inhibitors. However, the benefits of these agents remain to be shown in clinical end point trials. Combination treatments, for example, statins plus ACE inhibitors and statins plus fibrates, have also been demonstrated to have additive benefits on endothelial function in diabetes, but there are no clinical outcome data to date. Measurement of endothelial dysfunction in cardiovascular research can provide fresh opportunities for exploring the mechanism of benefit of new therapeutic regimens and for planning and designing large clinical trials.
Only a minority of patients referred for elective coronary artery bypass surgery have risk factors diagnosed and treated according to established guidelines
Authors: Anderson Russell E , Brismar Kerstin , Ivert Torbjörn 
Published: July 2007

Patients deserve to be medically optimised for treatment of metabolic risk factors and hypertension before referral for elective coronary artery bypass grafting (CABG). We describe here a prospective study of 347 consecutive patients referred for elective CABG. An oral glucose tolerance test (OGTT) was performed and metabolic risk factors and hypertension were determined pre-operatively. Compliance to treatment guidelines was calculated. From the total of 347 patients, 80 patients (23%) had known and 66 (19%) had previously unknown diabetes. Dysglycaemia (that is, diabetes and pre-diabetes) was found in 194 (73%) of the 267 patients without known diabetes. Among patients with dysglycaemia, 111/274 (41%) received one antihypertensive medication, or none, and blood pressure guidelines were met in 39/274 (14%); statins were being taken by 206 (75%; average dose 23 mg simvastatin) and low-density lipoprotein (LDL)-cholesterol guidelines were met in 43 (16%). In conclusion, diabetes diagnosis and titration of risk factor treatment to guidelines is inadequate even in elective CABG patients. A pre-admission OGTT affords an opportunity to improve care significantly.
Thiazolidinediones inhibit the progression of established hypertension in the Dahl salt-sensitive rat
Authors: Bolten Charles W , Payne Maria A , McDonald William G , Blanner Patrick M , Chott Robert C , Ghosh Sarbani , Arhancet Graciela B , Staten Nicholas R , Gulve Eric A , Sullivan Patrick M , Hromockyj Alexander E , Colca Jerry R 
Published: July 2007

We evaluated the effects of two thiazolidinediones (TZDs), the potent PPARγ agonist rosiglitazone currently being used to treat diabetes, and a structurally similar experimental compound that is a poor PPARγ agonist, in a non-diabetic, established hypertension model with continuous measurement of blood pressure by telemetry. Hypertension was induced in male Dahl salt-sensitive rats by a three-week pre-treatment with 4% salt before initiation of treatment. Fasting blood samples were taken for analysis of a biomarker panel to assess metabolic, anti-inflammatory and antioxidant activity of the treatments. Both TZDs significantly reduced both systolic and diastolic blood pressure. When used at the maximally effective doses established for metabolic improvement, both compounds produced equivalent reduction in lipids and elevation of adiponectin, yet the poorer PPARγ agonist produced significantly greater reductions in blood pressure. Neither compound had a significant effect on circulating glucose or insulin in this animal model.The data demonstrate that these TZDs lower blood pressure significantly in Dahl rats and that this cardiovascular pharmacology is not directly correlated with the metabolic actions or with the magnitude of PPARγ activation. These data suggest that it may be possible to find insulin-sensitising agents that have beneficial cardiovascular pharmacology with broad applications for disease prevention.
The ApoAI-CIII-AIV gene cluster and its relation to lipid levels in type 2 diabetes mellitus and coronary heart disease: determination of a novel susceptible haplotype
Authors: Singh Puneetpal , Singh Monica , Gaur Sunil , Kaur Taranpal 
Published: July 2007

The present study investigated genetic variation in the 3’ flanking region of ApoA-I ( PstI), the 3’ untranslated region of ApoC-III ( SstI) and intron 2 of ApoA-IV ( XbaI) in 435 type 2 diabetes mellitus patients, divided according to the presence or absence of coronary heart disease (CHD). Uncommon allele frequencies (P2, S2, X2) were 17.5%, 32.5%, 16.2% and 29.5%, 17.9%, 13.8% in patients with and without CHD, respectively. Linkage disequilibrium (D’ = 0.31-0.73, p<0.01) was observed in all diallelic pairs except XbaI/ PstI and XbaI/ SstI in patients having CHD. Haplotype analysis revealed that P1-S2-X1 is a susceptibility haplotype that increases the risk of CHD in diabetes (OR 2.85, CI 1.51-5.61), exacerbating risk (OR 3.57, CI 1.81-7.45) even after adjustment for confounders. The findings in the present study suggest that each unit of P1-S2-X1 in diabetes increases the risk of CHD by a factor of 1.37+0.307 (β ± SE), which is manifest in its multiplicative mode.
Insulin resistance is an independent risk factor for atherosclerosis in rheumatoid arthritis
Authors: Montagna Giovanni La , Cacciapuoti Federico , Buono Rosario , Manzella Daniela , Mennillo Gianna Angela , Arciello Alessandro , Valentini Gabriele , Paolisso Giuseppe 
Published: July 2007

The objective of this study was to investigate the relationship between insulin resistance (IR) and sub-clinical atherosclerosis in patients with rheumatoid arthritis (RA). Carotid artery intima media thickness (IMT), using ultrasound evaluation, and other clinical and laboratory variables were investigated in 45 RA outpatients and in 48 controls with soft tissue disorders. IR was assayed by homeostasis model assessment (HOMA2) and metabolic syndrome by National Cholesterol Education Program Adult Treatment Panel (NCEP ATP III) criteria. Insulin resistance, as defined by HOMA2-IR>1, was seen in 40 (88.9%) RA patients and in three (6.2%) controls (p<0.001). No significant difference was detected in the prevalence of metabolic syndrome. The median IMT was greater in RA patients (0.76 mm; interquartile range [IQR] 0.65, 0.85) than in the controls (0.66 mm; IQR 0.60, 0.72) (p<0.001). Dividing the RA patients according to the cut-off IMT value (0.72 mm), a difference was detected in both systolic (p=0.04) and diastolic blood pressure (p=0.02), disease activity score (DAS28) (p=0.008), HOMA2-IR (p<0.001) and cumulative oral steroid dose (p=0.001). Moreover, the frequency of cases with increased IMT was higher in glucocorticoid users than in non-users (21/23 vs. 9/22, respectively) (p<0.001). Spearman's rho correlation showed a significant positive relationship between IMT and HOMA2-IR (p<0.001). Multivariate stepwise analysis selected HOMA2-IR plus diastolic BP plus glucocorticoid exposure as the best predictive model for subclinical atherosclerosis (R2c=0.577, F=21, p<0.001). In conclusion, this study showed a significantly higher prevalence of IR in RA patients and pointed out a significant association between IR and subclinical atherosclerosis. This relationship may be driven primarily by exposure to steroid therapy.
The significance of low HDL-cholesterol levels in an ageing society at increased risk for cardiovascular disease
Authors: Windler Eberhard , Schöffauer Mark , Zyriax Birgit-Christiane 
Published: July 2007

In most developed and developing countries, the proportion of the population aged 60 years or more is growing faster than any other age group. Given that the vast majority of cardiovascular events occur in older individuals, new thinking is needed to reduce their risk. Epidemiological studies have shown an increasing prevalence of the metabolic syndrome with age, driven by nutrition inappropriate for a modern sedentary lifestyle. A low level of high-density lipoprotein (HDL)-cholesterol, a component of the atherogenic dyslipidaemia of the metabolic syndrome, has been shown to be an important determinant of coronary risk, which rises in prevalence with increasing age. Thus, raising HDL-cholesterol, in addition to lowering the level of low-density lipoprotein (LDL)-cholesterol, seems a plausible approach to reduce cardiovascular risk in an ageing population. Clinical studies have shown that adding nicotinic acid, which raises HDL-cholesterol by 20-25%, to a statin enhances the reduction in progression of atherosclerosis. Results of the ongoing Atherothrombosis Intervention in Metabolic syndrome with low HDL/High triglyceride and Impact on Global Health Outcomes (AIM-HIGH) study are awaited with interest to see whether such theoretical benefit translates into clinical outcome.
Homocysteine and cardiovascular disease: a review of the evidence
Authors: Wierzbicki Anthony S 
Published: July 2007

Elevated homocysteine (HCY) levels can be caused by a number of factors, including folate and B-vitamin deficiency, pre-existing atherosclerotic disease, diabetes and various drugs. Epidemiological evidence, as well as data from retrospective and prospective studies, supports an association between elevated HCY levels and increased risk of cardiovascular disease (CVD). However, whether lowering HCY levels by administration of folate and vitamins B6 and B12 is associated with any significant decrease in vascular risk remains the subject of ongoing debate. Although the major studies that have reported to date show that vitamin supplementation was associated with a decrease in HCY levels, this failed to have any significant effect on cardiovascular risk. Furthermore, although some lipid-modifying treatments have been shown to increase HCY levels, there is no evidence that this attenuates or compromises the beneficial effects of such treatments on cardiovascular risk. Taken together, these data suggest that HCY is a marker, rather than a cause, of CVD and therefore do not provide support for routine screening for and treatment of elevated HCY to prevent CVD. Data from ongoing clinical trials are awaited to clarify this issue.
Acrylic pressure‐sensitive adhesive for transdermal drug delivery systems
Authors: Czech Zbigniew , Kurzawa Rafał 
Published: July 2007

AbstractThis article describes the development in the area of resin‐free acrylic pressure‐sensitive adhesive (PSA) based on 2‐ethylhexyl acrylate, methyl acrylate, acrylic acid, N‐vinyl caprolactam, and pregnancy transdermal drug delivery systems, and shows the variety of polymer composition, residue monomers content, quality control of peel adhesion level and repeating during the time, biocompatibility of the acrylic PSA layer, and efficacy in clinical medicine. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Preparation of unsaturated polyester–silica nanocomposites
Authors: Chung Chan‐Moon , Cho Sung‐Youl , Kim Joong‐Gon , Oh Se Young 
Published: July 2007

AbstractTwo unsaturated polyesters (UPs), PME and PMPE, were synthesized by condensation polymerization, and another UP, BPMPE, was prepared from PMPE by blocking of its carboxyl and hydroxyl end groups. Optically transparent UP–silica nanocomposites were prepared by a sol–gel process of alkoxysilanes in the presence of the UPs. Compared to the unblocked UPs, PME and PMPE, the blocked UP, BPMPE, afforded transparent nanocomposites in a wider range of feed ratio of UP/alkoxysilane. Intermolecular hydrogen bonding and π–π interaction between the organic and inorganic components were dominant factors in the nanocomposite formation when acetone was used as a solvent. Various solvents were tested and it was thought that hydrogen bonding acceptor property and boiling point of the solvents were important factors in the formation of the transparent nanocomposites. Photo‐crosslinking of an UP in its nanocomposite resulted in the formation of an interpenetrating polymer network structure. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Organic Approaches to Endohedral Metallofullerenes: Cracking Open or Zipping Up Carbon Shells?
Authors: Rubin Yves 
Published: July 2007

AbstractWe have been investigating the synthesis of endohedral metallofullerenes since we successfully opened an orifice on the framework of C60 in the form of a cobalt complex having the metal sitting on top of the opening. A second approach aims at the synthesis of spherically‐shaped acetylenic macrocycles, which are expected to rearrange to endohedral metal complexes of fullerenes in a controlled process analogous to the gas‐phase coalescence of mono‐ and polycyclic polyynes during fullerene formation by the graphite evaporation method. Since the potential benefits from obtaining endohedral metal complexes of C60 are enormous, both approaches are being actively pursued in our group.
Peptide Self‐Replication Via Template‐Directed Ligation
Authors: Severin Kay , Lee David H. , Martinez Jose A. , Ghadiri M. Reza 
Published: July 2007

AbstractA 32‐residue α‐helical peptide with a sequence similiar to that of the GCN4 leucine zipper region is shown to catalyze its own formation by accelerating the amide bond formation of a 17‐residue peptide, preactivated as a thiobenzyl ester, and a 15‐residue peptide with aN‐terminal cysteine. The self‐replication process displays parabolic growth characteristics as revealed by a detailed kinetic analysis. Control reactions with single‐mutant peptides strongly support a mechanism in which a ternary and/or quaternary complex of the product with both peptide fragments act(s) as the catalytically active intermediate(s). Furthermore, these experiments reveal a remarkable sequence selectivity, as evidenced by the loss of autocatalytic activity as a result of a single replacement of leucine or valine residues with an alanine at the recognition interface.