bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the properties of discrete adjoints of numerical methods for the advection equation
Authors: Liu Zheng , Sandu Adrian 
Published: August 2007

AbstractThis paper discusses several aspects related to the consistency of the discrete adjoints of upwind numerical schemes. Both linear (finite differences, finite volumes) and nonlinear (slope and flux‐limited) discretizations of the one‐dimensional advection equation are considered. The analysis is focused on uniform meshes and on explicit numerical schemes. We show that the discrete adjoints may lose consistency near the points where upwinding changes, near inflow boundaries where another numerical scheme is employed, and near the locations where the slope/flux limiter is active in the forward simulation. Numerical results are presented to support the theoretical analysis. Copyright © 2007 John Wiley & Sons, Ltd.
Extension of efficient, swept‐integration‐based conservative remapping method for meshes with changing connectivity
Authors: Kucharik M. , Shashkov M. 
Published: August 2007

AbstractRemapping is one of the essential parts of most arbitrary Lagrangian–Eulerian methods. Here, we extend the idea of swept integration introduced in (J. Comput. Phys. 2003; 184(1):266–298) to meshes with connectivity changing in Voronoi‐like manner. To demonstrate properties of the developed method, we present several numerical examples. Published in 2007 by John Wiley & Sons, Ltd.
Colposcopy is not necessary to assess the risk to the cervix in HIV‐positive women: An international cohort study of cervical pathology in HIV‐1 positive women
Authors: Kitchener Henry , Nelson Linsey , Adams Joanna , Mesher David , Sasieni Peter , Cubie Heather , Moore Catherine , Heard Isabelle , Agarossi Alberto , Casolati Elena , Denny Lynette , Bradbeer Caroline , Lyons Fiona , Beattie Gerry , Niemiec Tomasz 
Published: August 2007

AbstractThe objectives of this prospective multicentre international cohort study are to describe the characteristics of a cohort of HIV‐1 positive women and determine the best management system by comparing cervical pathology according to results of cytology, colposcopy and human papillomavirus (HPV) testing at baseline and throughout follow‐up. A. Cohorts of known HIV‐positive women were recruited from 6 hospital‐based European centres and a community‐based South African centre. Following registration, women were reviewed every 6 months to undergo cervical surveillance including cytology, colposcopy, histopathology and HPV testing, using the HPV hybrid capture assay. Independent risk factors for the incidence of cytological abnormality and acquisition/clearance of HPV infection during follow up were identified. A total of 1,534 women were recruited, 400 of which were from South Africa. At baseline, among European women, 66% had normal cytology and half were HPV negative and among South African women, 45% had normal cytology and one third (32%) were HPV negative. The sensitivity of cytology (≥ASCUS) matched with that of colposcopy to detect CIN2+. Rate of detection of high grade CIN at 2 years was similar in European and South African women (11 and 9.3%, respectively). Cytology and HPV testing alone were each sufficiently sensitive as a screening test at 2 yearly intervals. Our data confirm the high prevalence of low‐grade cytological abnormalities and high‐risk HPV infection. Cytology appears to be sufficient for cervical surveillance, with HPV testing being less specific with poor positive predictive value. There appears to be no additional benefit from routine colposcopy. © 2007 Wiley‐Liss, Inc.
Determination of chemically reduced pyrrolobenzodiazepine SJG‐136 in human plasma by HPLC‐MS/MS: application to an anticancer phase I dose escalation study
Authors: Wade Calcutt M. , Lee Wooin , Puzanov Igor , Rothenberg Mace L. , Hachey David L. 
Published: August 2007

AbstractSJG‐136 1,1′‐[[(propane‐1,3‐diyl)dioxy]bis[(11aS)‐7‐methoxy‐2‐methylidene‐1,2,3,11a‐tetrahydro‐5H‐pyr‐ rolo[2,1‐c][1,4]benzodiazepin‐5‐one]] (NSC 694501), is a bifunctional pyrrolobenzodiazepine (PBD) dimer that forms selective, irreversible, interstrand DNA cross‐links via exocyclic N2 atoms of two guanine bases, with a preference for 5′PuGATCPy binding sites. SJG‐136 is highly cytotoxic in human tumor cells in vitro and in human tumor xenograft models in vivo at subnanomolar concentrations and is currently in anticancer phase I clinical trials in the United Kingdom and United States. To support correlative pharmacokinetics studies, a highly sensitive HPLC‐MS/MS assay was developed and validated for the reliable quantitation of SJG‐136 in human plasma, using the structurally similar PBD dimer DSB‐120 as an internal standard. Chemical reduction of SJG‐136 to its corresponding amine (SJG‐136‐H4, [M + H]+m/z 561) improved HPLC peak resolution and sensitivity by minimizing complications that arose from the reactivity of the labile imine moieties. Plasma samples were processed by protein precipitation and centrifugal membrane dialysis; components were separated by HPLC using an Agilent Rapid Resolution HT 1.8 mm (2.1 mm × 50 mm) analytical column. The total analysis time from injection to injection was 11 min. Electrospray MS/MS detection of SJG‐136‐H4 was based on the selected reaction monitoring (SRM) transition [M + H]+m/z 561 → 301. The analytical response ratio was linearly proportional to the plasma concentration of SJG‐136 over the nominal concentration range of 25 pg/ml to 250 ng/ml, with a coefficient of determination of r ≥ 0.999. The intrarun absolute %RE was ≤19.6, 14.2, and 14.0% at 0.056, 2.83, and 56.3 ng/ml, respectively. The corresponding %RSD was ≤14.9%, 9.01, and 4.59%. The interday %RSD was ≤2.72, 3.46, and 5.20%. The lower and upper limits of quantitation were 0.056 and 56 ng/ml, respectively; recovery of SJG‐136 from plasma was ≥ 62% across the validated concentration range. The sensitivity of the validated assay was sufficient to detect SJG‐136 in human subjects for up to 6 h after intravenous administration of 6 µg/m2, the starting dose of an NCI‐sponsored dose escalation study. Copyright © 2007 John Wiley & Sons, Ltd.
Network requirements for sensor accuracy and precision: a case study to assess atmospheric variability in simple terrain
Authors: Melvin Melissa J. , Zygielbaum Arthur I. , Gutzmer Denise , Rentschler Scott , Bower Jeremy , Hubbard Kenneth G. 
Published: August 2007

AbstractThis simulation‐based study is an effort to develop design requirements for a hypothetical network of instruments to measure average atmospheric variability over a relatively simple terrain. A dataset of air and soil temperature, relative humidity, wind speed, and soil moisture from the vicinity of Lincoln, Nebraska, was used to simulate atmospheric daily measurements (max and min temperature as well as infra‐red surface temperature (grass cover), relative humidity, wind speed and soil moisture) at various distances from the site. An analysis was performed to determine the instrumentation requirements needed to distinguish natural atmospheric variability from input instrumental error at the 0.05 significance level. Both accuracy and precision requirements were examined to determine the affect of systematic and random errors, respectively. It was found that sensor accuracy (small systematic bias relates to high accuracy) does not affect the ability to determine the atmospheric spatial variability. However, sensor precision (small random error equates to high precision) was found to affect the ability to determine the spatial variability of the atmospheric variable in question; commercial sensors are currently available that meet or exceed the precision requirements for all except one of the variables examined. Copyright © 2007 Royal Meteorological Society
An empirical model for the seasonal prediction of southwest monsoon rainfall over Kerala, a meteorological subdivision of India
Authors: Nayagam Lorna R. , Janardanan Rajesh , Mohan H. S. Ram 
Published: August 2007

AbstractThere are several studies showing a skillful empirical prediction of the All India Summer Monsoon Rainfall (AISMR) based on various combination of parameters as the predictors. However, the southwest monsoon rainfall over Kerala, a meteorological subdivision of India, bears a considerably low correlation coefficient with the AISMR. This implies that the existing predictors in the long‐range forecast models of the AISMR do not have much influence on the Kerala Summer Monsoon Rainfall (KSMR). This study attempts to examine the relationship of some ocean and atmospheric parameters with the rainfall and to formulate a linear multiple regression model for the long‐range forecast over a small area like the Kerala. Parameters having significant correlation (significant at 1% level) with the KSMR were identified for the period 1961–1994. The consistency of the relationship between these parameters and the KSMR was checked by doing a 21‐year sliding window correlation (significant at 5% level). Using a stepwise regression method, seven predictors, explaining a significant amount of variance in the KSMR were selected and a linear multiple regression model was developed. The parameters that explain the high inter‐annual variability of the KSMR are specific humidity, sensible heat net flux, relative humidity, zonal wind at 70 and 10 hPa, meridional wind and geopotential height. The characteristics of the forecast and its reliability were studied by various statistical techniques such as, Durbin Watson statistics and variance inflation factor. The model has a multiple correlation of 0.943 and coefficient of determination of 88.8%. The root mean square error (RMSE) was 6.60% (15.80%), bias (BIAS) was − 0.26% (6.20%), absolute error (ABSE) was 5.33% (13.15%) of mean rainfall for the training (test) period respectively. Climatological predictions were also made and the RMSE was (17.90%), BIAS (−5.40%) and ABSE (15.16%) of mean rainfall. The selected parameters were at least 2 months prior to the monsoon season and hence have predictive value. Copyright © 2007 Royal Meteorological Society
Air temperature variation with time and thermally evaluated atmospheric conditions correlated with land use change in urban areas of Japan
Authors: Aikawa Masahide , Hiraki Takatoshi , Eiho Jiro , Miyazaki Hiroshi 
Published: August 2007

AbstractThe trends and variations in air temperature from 1987 to 2004 correlated with land use patterns in urban areas of Japan were studied in terms of urban heat islands. The air temperatures seemed to show an increasing trend; however, the differences were statistically insignificant due to the large variation and short survey period. The large increase rate of the air temperature was observed in the spring. The increasing rate of the air temperature at nighttime was larger than that during the daytime. The land use pattern was analysed using land use data prepared by the National Land Agency of Japan, and changes in land use were numerically explained by applying the thermal property parameter (c−1ρ−1κ−1/2). The relationship between the air temperature variation after sunset and the thermal property parameter was examined, and the air temperature variation after sunset was accounted for by the thermal property parameter. Copyright © 2007 Royal Meteorological Society
Surface air temperature trends in Southern Brazil for 1960–2002
Authors: Marengo Jose A. , Camargo Claudia C. 
Published: August 2007

AbstractTrends in minimum and maximum air temperature and in the diurnal thermal range (DTR), and derived indices of extreme temperatures since the 1960's are assessed for southern Brazil. Most meteorological stations show steep increases in the night‐time temperatures (depicted by the minimum temperature) as compared to slight increases in the daytime temperature (depicted by the maximum temperature), both year round and at the seasonal level. The warming trends are stronger during winter as compared to summer. Consequently, the observed annual and seasonal negative DTR trends in southern Brazil during the last 40 years are largely due to the greater increase in nighttime temperatures rather than daytime temperatures. At decadal timescales, the presence of more intense and frequent El Niño events during the last 20 years also contributes to warming and explains the steep increase in the air temperature extremes trends during this period, as compared to the relatively colder 1960–1980 period, especially for winter.Indices of temperature extremes defined using fixed limits for maximum and minimum temperatures for colder or warmer days were compared with percentile‐based indices defined in the recent literature. The comparison shows that the frequency of warmer days increased during both summer and winter, especially during the last two decades. The observed positive tendencies in minimum temperatures and warmer days during winter occur even though extreme cold events and freezing conditions occurred in 1975, 1994 and 2000. Copyright © 2007 Royal Meteorological Society
Simultaneous determination of formic acid and lower carbonyls in air samples by DNPH derivatization
Authors: Possanzini Massimiliano , Tagliacozzo Giorgio , Cecinato Angelo 
Published: August 2007

AbstractThe classical derivatization method of carbonyls based on 2,4‐dinitrophenylhydrazine (DNPH)‐coated silica cartridges was tested to concurrently measure lower carbonyls and carboxylic acids in air samples. The performance of these cartridges with respect to formic and acetic acids was evaluated in a number of laboratory measurements on collection and reaction efficiencies. The results showed that HCOOH appeared to have been efficiently collected and derivatized (at 80°C for 8 h) up to air‐flow rates of 350 mL/min, while CH3COOH was almost completely lost from the cartridge above 100 mL/min. Also due to the high LOD of HCOOH (0.8 μg/m3) for 120 L of air sampled during 8 h, the DNPH method might be used only in indoor environments polluted by formic acid as well as carbonyls.
Rapid HPLC analysis of the antiepileptic lamotrigine and its metabolites in human plasma
Authors: Saracino Maria Addolorata , Bugamelli Francesca , Conti Matteo , Amore Mario , Raggi Maria Augusta 
Published: August 2007

AbstractA liquid chromatographic method with diode array detection (DAD) has been developed for the analysis of the antiepileptic agent lamotrigine (LTG) and its metabolites, lamotrigine 2‐N‐glucuronide and 2‐N‐methylated in plasma samples. The analytes were separated on a C8 RP column, using a mobile phase composed of methanol and a 0.45 mM, pH 3.5 phosphate buffer containing 0.17% triethylamine (24:76 v/v). Melatonin was used as the internal standard (IS). The DAD detector was set at 220 nm for the detection of all the analytes. A simple protein precipitation with methanol guaranteed high extraction yield values (>90%) and good purification from matrix interference. Good linearity was obtained in the 0.1–15.0 μg/mL range for LTG and lamotrigine 2‐N‐glucuronide and in the 0.1–2.0 μg/mL range for lamotrigine 2‐N‐methylated. The analytical method was validated in terms of precision, extraction yield, and accuracy. These assays gave RSD% values for precision always lower than 4.3% and mean accuracy higher than 80%. The method seems to be suitable for the analysis of plasma samples from patients treated with Lamictal.
Multiresidue HPLC analysis of ten quinolones in milk after solid phase extraction: Validation according to the European Union Decision 2002/657/EC
Authors: Christodoulou Eleni A. , Samanidou Victoria F. 
Published: August 2007

AbstractA rapid and sensitive analytical method was developed for the residue analysis of ten quinolones (enoxacin (ENO), ofloxacin (OFL), norfloxacin (NOR), ciprofloxacin (CIP), danofloxacin (DAN), enrofloxacin (ENR), sarafloxacin (SAR), oxolinic acid (OXO), nalidixic acid (NAL), and flumequine (FLU)) in cow's milk. The analytes were extracted from milk by a deproteinization step followed by a simple SPE cleanup procedure using LiChrolut RP‐18 Merck cartridges. Recoveries varied between 75 and 92%. HPLC separation was performed at 25°C using an ODS‐3 PerfectSil® Target (250×4 mm2) 5 μm analytical column (MZ‐Analysentechnik, Germany). The mobile phase consisted of a mixture of TFA 0.1%–CH3CN–CH3OH, delivered by a gradient program at the flow rate of 1.2 mL/min. Elution of the ten analytes and the internal standard (caffeine, 7.5 ng/μL) was completed within 27 min. Column effluent was monitored using a photodiode array detector, set at 275 and 255 nm. The developed method was validated according to the criteria of Commission Decision 2002/657/EC. The LODs of the specific method of quinolones' determination in milk varied between 1.5 and 6.8 ng/μL.
Selective extraction of peptides in acidic human plasma by porous silica nanoparticles for peptidome analysis with 2‐D LC‐MS/MS
Authors: Tian Ruijun , Ye Mingliang , Hu Lianghai , Li Xin , Zou Hanfa 
Published: August 2007

AbstractIn this study, an improved method for human plasma peptidome analysis including selective porous silica nanoparticles (MCM‐41) extraction and subsequent online 2‐D nano‐LC‐MS/MS analysis was established. Enhanced enrichment efficiency for the MCM‐41 extraction was obtained by adjusting the pH of the plasma sample to 2.5. A total of 1680 unique peptides were identified in the plasma sample obtained from one healthy donor, which is nearly twice the amount identified from the native state of the plasma sample. The hydrophobic property, molecular weight (MW), and pI distribution of the identified peptides at pH 2.5 and native state of the plasma sample were systematically investigated and compared. Furthermore, many unusual cleaved peptides from plasma proteins (e. g., HSA) were observed at pH 2.5, which clearly show a ladder pattern. The cleavage patterns for all of the identified peptides at pH 2.5 were summarized, and chymosin and cathepsin D were confirmed as the possible peptidases responsible for the change of cleavage pattern in peptide profiling.
Polymorphisms in drug metabolism genes, smoking, and p53 mutations in breast cancer
Authors: Van Emburgh Beth O. , Hu Jennifer J. , Levine Edward A. , Mosley Libyadda J. , Case L. Douglas , Lin Hui‐Yi , Knight Sommer N. , Perrier Nancy D. , Rubin Peter , Sherrill Gary B. , Shaw Cindy S. , Carey Lisa A. , Sawyer Lynda R. , Allen Glenn O. , Milikowski Clara , Willingham Mark C. , Miller Mark Steven 
Published: August 2007

AbstractPolymorphisms in phase I and phase II enzymes may enhance the occurrence of mutations at critical tumor suppressor genes, such as p53, and increase breast cancer risk by either increasing the activation or detoxification of carcinogens and/or endogenous estrogens. We analyzed polymorphisms in CYP1B1, GSTM1, GSTT1, and GSTP1 and p53 mutations in 323 breast tumor samples. Approximately 11% of patients exhibited mutations in p53. Women with mutations had a significantly younger age of diagnosis (P = 0.01) and a greater incidence of tumors classified as stage II or higher (P = 0.002). More women with mutations had a history of smoking (55%) compared to women without mutations (39%). Although none of the genotypes alone were associated with p53 mutations, positive smoking history was associated with p53 mutations in women with the GSTM1 null allele [OR = 3.54; 95% CI = 0.97–12.90 P = 0.06] compared to women with the wild‐type genotype and smoking history [OR = 0.62, 95% CI = 0.19–2.07], although this association did not reach statistical significance. To test for gene–gene interactions, our exploratory analysis in the Caucasian cases suggested that individuals with the combined GSTP1 105 VV, CYP1B1 432 LV/VV, and GSTM1 positive genotype were more likely to harbor mutations in p53 [OR = 4.94; 95% CI = 1.11–22.06]. Our results suggest that gene–smoking and gene–gene interactions may impact the prevalence of p53 mutations in breast tumors. Elucidating the etiology of breast cancer as a consequence of common genetic polymorphisms and the genotoxic effects of smoking will enable us to improve the design of prevention strategies, such as lifestyle modifications, in genetically susceptible subpopulations. © 2007 Wiley‐Liss, Inc.
A novel method to measure both the reductive and the radical scavenging activity in a linoleic acid model system
Authors: Lindenmeier Michael , Burkon Alexander , Somoza Veronika 
Published: August 2007

AbstractThe aim of this study was to develop a combined method for measuring the total antioxidant activity, the reductive and the radical scavenging activity. Linoleic acid was used as the substrate for an iron‐initiated lipid peroxidation to measure the total antioxidant activity. In addition, methyl esters of linoleic acid hydroperoxides were used as substrates to measure the reductive antioxidant activity. The radical scavenging antioxidant activity was calculated by subtracting the reductive antioxidative activity from the total antioxidative activity. As representative examples, the antioxidants α‐tocopherol, ascorbic acid, trans‐resveratrol and L‐gluthatione as well as commonly used food additives such as 2(3)‐tert‐butyl‐4‐hydroxyanisole (BHA) and 2,6‐bis(1,1‐dimethylethyl)‐4‐methylphenol (BHT) were analyzed. The results for the novel antioxidation test showed that α‐tocopherol, BHA and BHT are primarily acting as radical scavengers, whereas ascorbic acid and L‐gluthatione show a strong reductive capacity. As linoleic acid as well as its hydroperoxides both are present in foods and in the organism, the test presented here can be considered representative of radical reactions occurring in food matrixes and in vivo. Further experiments are required to document the comprehensive applicability in foods and in vivo.
Neurophysiological study in a Spanish family with recessive spastic ataxia of Charlevoix‐Saguenay
Authors: García Antonio , Criscuolo Chiara , de Michele Giuseppe , Berciano José 
Published: August 2007

AbstractIn order to characterize the electrodiagnostic features of autosomal‐recessive spastic ataxia of Charlevoix‐Saguenay (ARSACS) more fully, we report the clinical and neurophysiological findings in two patients from a Spanish pedigree with a homozygous missense point mutation in the SACS gene. Nerve conduction studies showed signs of both axonal and demyelinating neuropathy. In the upper‐limb nerves, motor conduction velocity was intermediately slowed. Sensory nerve action potentials were attenuated or absent. In addition, slowed conduction in the central motor, somatosensory, and auditory brainstem pathways was observed, and masseter and blink reflexes were abnormal. As a whole, this constellation of electrophysiological findings helps in the diagnosis of ARSACS. Muscle Nerve, 2007
Estimating gluconeogenesis by NMR isotopomer distribution analysis of [13C]bicarbonate and [1‐13C]lactate
Authors: Alves Tiago Cardoso , Nunes Patrícia Maria , Palmeira Carlos Marques , Jones John Griffith , Carvalho Rui Albuquerque 
Published: August 2007

AbstractThe gluconeogenic contribution to glucose production in livers isolated from rats fasted for 24 h was determined by 13C‐NMR isotopomer distribution analysis of secreted glucose enriched from 99% [13C]bicarbonate (n = 4) and 99% [1‐13C]lactate (n = 4). Experiments with 3% 2H2O were also performed, allowing the gluconeogenic contribution to be measured by the relative 2H enrichments at positions 5 and 2 of glucose. From 13C‐NMR analyses, the contribution of gluconeogenesis to glucose output was estimated to be 93 ± 3% for [13C]bicarbonate perfusion and 91 ± 3% for [1‐13C]lactate perfusion, in good agreement with the 2H‐NMR analysis of the gluconeogenic contribution to glucose production (100 ± 1% and 99 ± 1%, respectively) and consistent with the expected negligible contribution from glycogenolysis. These results indicate that 13C‐NMR analysis of glucose 13C‐isotopomer distribution from either [13C]bicarbonate or [1‐13C]lactate precursor provides realistic estimates of the gluconeogenic contribution to hepatic glucose output. Copyright © 2007 John Wiley & Sons, Ltd.