bluuebunny/crossref_metadata_2025 huggingface dataset:
Desymmetrization of meso‐Bicyclic Hydrazines by Rhodium‐Catalyzed Enantioselective Hydroformylation
Authors: Bournaud Chloée , Lecourt Thomas , Micouin Laurent , Méliet Catherine , Agbossou‐Niedercorn Francine
Published: March 2008

An asymmetric hydroformylation of three meso‐bicyclic hydrazines followed by the reduction of the formyl product afforded the corresponding desymmetrized optically enriched hydroxymethyl hydrazines (up to 77.5 % ee). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
The Steensby Inlet Ice Stream in the context of the deglaciation of Northern Baffin Island, Eastern Arctic Canada
Authors: Dyke Arthur S.
Published: March 2008

Deglaciation of northern Baffin Island involved several large ice streams with contrasting histories. Three north‐flowing, marine‐based ice streams were in place during the Last Glacial Maximum, but they retreated at widely varying rates during the early and middle Holocene. The Steensby Inlet Ice Stream formed in response to over‐steepening of the ice front during deglaciation of Foxe Basin. It caused an abrupt change, in places a general reversal, of flow about 6 ka BP and operated across its full width for only about 500 years. Nevertheless, it left a distinct subglacial footprint, including an hourglass shaped bedform set. A dense network of till samples from the region of the ice stream reveals a sharp‐sided, pluglike dispersal of carbonate debris that was sustained by erosion in the source area of about 5 mm a−1. The ice stream devolved into valley‐controlled ice streams separated by cold‐based ice over interfluves. The former evacuated debris along valleys and left erosional till scarps along the sides of sliding ice. Post‐ice‐stream end moraines, including the large Gifford Moraine, require later cold‐based flow across the drumlins formed by the ice stream. Copyright © 2008 John Wiley & Sons, Ltd.
Calculation of IBD probabilities with dense SNP or sequence data
Authors: Keith Jonathan M. , McRae Allan , Duffy David , Mengersen Kerrie , Visscher Peter M.
Published: March 2008

The probabilities that two individuals share 0, 1, or 2 alleles identical by descent (IBD) at a given genotyped marker locus are quantities of fundamental importance for disease gene and quantitative trait mapping and in family‐based tests of association. Until recently, genotyped markers were sufficiently sparse that founder haplotypes could be modelled as having been drawn from a population in linkage equilibrium for the purpose of estimating IBD probabilities. However, with the advent of high‐throughput single nucleotide polymorphism genotyping assays, this is no longer a reasonable assumption. Indeed, the imminent arrival of individual sequencing will enable high‐density single nucleotide polymorphism genotyping on a scale for which current algorithms are not equipped. In this paper, we present a simple new model in which founder haplotypes are modelled as a Markov chain. Another important innovation is that genotyping errors are explicitly incorporated into the model. We compare results obtained using the new model to those obtained using the popular genetic linkage analysis package Merlin, with and without using the cluster model of linkage disequilibrium that is incorporated into that program. We find that the new model results in accuracy approaching that of Merlin with haplotype blocks, but achieves this with orders of magnitude faster run times. Moreover, the new algorithm scales linearly with number of markers, irrespective of density, whereas Merlin scales supralinearly. We also confirm a previous finding that ignoring linkage disequilibrium in founder haplotypes can cause errors in the calculation of IBD probabilities. Genet. Epidemiol. 2008. © 2008 Wiley‐Liss, Inc.
Fragile X‐associated primary ovarian insufficiency: evidence for additional genetic contributions to severity
Authors: Hunter Jessica Ezzell , Epstein Michael P. , Tinker Stuart W. , Charen Krista H. , Sherman Stephanie L.
Published: March 2008

The fragile X mental retardation gene (FMR1) contains a CGG repeat sequence in its 5′ untranslated region that can become unstable and expand in length from generation to generation. Alleles with expanded repeats in the range of ∼55–199, termed premutation alleles, are associated with an increased risk for fragile‐X‐associated primary ovarian insufficiency (FXPOI). However, not all women who carry the premutation develop FXPOI. To determine if additional genes could explain variability in onset and severity, we used a random‐effects Cox proportional hazards model to analyze age at menopause on 680 women from 225 families who have a history of fragile X syndrome and 321 women from 219 families from the general population. We tested for the presence of a residual additive genetic effect after adjustment for FMR1 repeat length, race, smoking, body mass index, and method of ascertainment. Results showed significant familial aggregation of age at menopause with an estimated additive genetic variance of 0.55–0.96 depending on the parameterization of FMR1 repeat size and definition of age at menopause (P‐values ranging between 0.0002 and 0.0027). This is the first study to analyze familial aggregation of FXPOI. This result is important for proper counseling of women who carry FMR1 premutation alleles and for guidance of future studies to identify additional genes that influence ovarian insufficiency. Genet. Epidemiol. 2008. © 2008 Wiley‐Liss, Inc.
Synthesis, DNA‐Binding and Photocleavage Studies of the Ruthenium(II) Complexes [Ru(phen)2(ppd)]2+ and [Ru(phen)(ppd)2]2+ (ppd=Pteridino[6,7‐f] [1,10]phenanthroline‐11,13(10H,12H)‐dione, phen=1,10‐Phenanthroline)
Authors: Gao Feng , Chao Hui , Wei Yuan‐Fang , Yuan Yi‐Xian , Peng Bin , Chen Xin , Zheng Kang‐Cheng , Ji Liang‐Nian
Published: March 2008

Two new complexes, [Ru(phen)2(ppd)]2+ (1) and [Ru(phen)(ppd)2]2+ (2) (ppd=pteridino[6,7‐f] [1,10]phenanthroline‐11,13(10H,12H)‐dione, phen=1,10‐phenanthroline) were synthesized and characterized by ES‐MS, 1H‐NMR spectroscopy, and elemental analysis. The intercalative DNA‐binding properties of 1 and 2 were investigated by absorption‐spectroscopy titration, luminescence‐spectroscopy studies, thermal denaturation, and viscosity measurements. The theoretical aspects were further discussed by comparative studies of 1 and 2 by means of DFT calculations and molecular‐orbital theory. Photoactivated cleavage of pBR322 DNA by the two complexes were also studied, and 2 was found to be a much better photocleavage reagent than 1. The mechanism studies revealed that singlet oxygen and the excited‐states redox potentials of the complex may play an important role in the DNA photocleavage.
Unusual Nortriterpenoid Saponins from Stauntonia chinensis
Authors: Gao Hao , Wang Zhao , Yao Zhi‐Hong , Wu Ning , Dong Hua‐Jin , Li Jin , Wang Nai‐Li , Ye Wen‐Cai , Yao Xin‐Sheng
Published: March 2008

Four new saponins, yemuosides YM17–YM20 (1–4, resp.), were isolated from the rattan of Stauntonia chinensis DC. (Lardizabalaceae) along with a known saponin, nipponoside D (5). Their structures were elucidated by spectroscopic analysis and chemical evidence as 20,30‐dihydroxy‐29‐noroleanolic acid 28‐O‐α‐L‐rhamnopyranosyl‐(1→4)‐β‐D‐glucopyranosyl‐(1→6)‐β‐D‐glucopyranosyl ester (1), 20,29‐dihydroxy‐30‐noroleanolic acid 28‐O‐α‐L‐rhamnopyranosyl‐(1→4)‐β‐D‐glucopyranosyl‐(1→6)‐β‐D‐glucopyranosyl ester (2), 29‐hydroxy‐30‐norolean‐20(21)‐enolic acid 28‐O‐α‐L‐rhamnopyranosyl‐(1→4)‐β‐D‐glucopyranosyl‐(1→6)‐β‐D‐glucopyranosyl ester (3), 29‐hydroxyoleanolic acid 28‐O‐α‐L‐rhamnopyranosyl‐(1→4)‐β‐D‐glucopyranosyl‐(1→6)‐β‐D‐glucopyranosyl ester (4), and 23,29‐dihydroxyoleanolic acid 28‐O‐α‐L‐rhamnopyranosyl‐(1→4)‐β‐D‐glucopyranosyl‐(1→6)‐β‐D‐glucopyranosyl ester (5). Yemuoside YM17–YM19 (1–3, resp.) contain novel unusual nortriterpene aglycones.
Peat hydraulic conductivity in cold regions and its relation to pore size and geometry
Authors: Quinton William L. , Hayashi Masaki , Carey Sean K.
Published: March 2008

Subsurface flow through peat plays a critical role in the hydrology of organic‐covered, permafrost terrains, which occupy a large part the continental arctic, sub‐arctic, and boreal regions. Hillslope drainage in these terrains occurs predominantly through the active flow zone between the relatively impermeable frost table and the water table above it. The hydraulic conductivity profile within this zone controls the subsurface drainage of snowmelt and storm water. Peat hydraulic conductivity profiles were examined at three sites in north‐western Canada, each representing a widely occurring organic‐covered, permafrost terrain type. Three independent measures of saturated hydraulic conductivity were used—tracer tests, constant‐head well‐permeameter tests, and laboratory measurements of undisturbed samples. At all three sites, the conductivity profiles contained very high values (10–1000 m d−1) within the top ca 0·1 m where the peat is only lightly decomposed, a large reduction with increasing depth below the ground surface in the transition zone, and relatively low values in a narrow range (0·5–5 m d−1) below ca 0·2 m depth, where the peat is in an advanced state of decomposition. Digital image analysis of resin‐impregnated peat samples showed that hydraulic conductivity is essentially controlled by pore hydraulic radius. The strong dependence of hydraulic conductivity on hydraulic radius implies that peat soils subjected to similar degrees of decomposition and compaction have a similar hydraulic conductivity regardless of the location. This explains the similarity of the depth‐conductivity profiles among all three terrain types. Copyright © 2008 John Wiley & Sons, Ltd.
Reverse transcriptase inhibitors induce cell differentiation and enhance the immunogenic phenotype in human renal clear‐cell carcinoma
Authors: Landriscina Matteo , Altamura Settimia Anna , Roca Leonarda , Gigante Margherita , Piscazzi Annamaria , Cavalcanti Elisabetta , Costantino Eleonora , Barone Carlo , Cignarelli Mauro , Gesualdo Loreto , Ranieri Elena
Published: March 2008

Reverse transcriptase (RT) inhibitors are emerging as a novel class of anticancer differentiating agents, active in several human tumor cell models, such as melanoma and prostate, thyroid and colon carcinoma. Indeed, much evidence suggests that they may act by inhibiting endogenous RT, a gene highly expressed in undifferentiated and transformed cells. We therefore evaluated whether endogenous RT may represent a new molecular target in the treatment of human renal clear‐cell carcinoma, a neoplasm with very low sensitivity to standard pharmacological therapies. Efavirenz and nevirapine, 2 non‐nucleosidic RT inhibitors commonly used in HIV patients, either induced a reversible downregulation of cell proliferation or enhanced cell differentiation in primary cultures of human renal carcinoma cells characterized by high levels of endogenous RT activity. Both agents upregulated the expression of the vitamin D receptor and calbindin 28k genes, which are constitutively expressed in renal tubular cells, and induced vitamin D signaling by enhancing the ability of tumor cells to upregulate the vitamin D‐dependent gene, CYP24. Furthermore, efavirenz‐ and nevirapine‐differentiated tumor cells exhibited an immunogenic phenotype with an increased expression of HLA‐I and CD40 antigens and an enhanced ability to elicit a specific T‐cell response in mixed lymphocyte/tumor‐cell cultures. Indeed, renal carcinoma cells exposed to efavirenz induced a CD8+CCR7‐CD45RA− effector memory T‐cell phenotype, whereas untreated RCC cells induced a CD8+CCR7+CD45RA− central memory T‐cell phenotype. These data suggest that RT inhibitors may be a novel tool in the treatment of human renal clear‐cell carcinoma, potentially able to enhance the immunogenic potential of tumor cell. © 2008 Wiley‐Liss, Inc.
Src kinase induces tumor formation in the c‐SRC C57BL/6 mouse
Authors: Kline Christina Leah B. , Jackson Rosalind , Engelman Robert , Pledger Warren Jack , Yeatman Timothy J. , Irby Rosalyn B.
Published: March 2008

Src kinase has been linked as a causative agent in the progression of a number of cancers including colon, breast, lung and melanoma. Src protein and activity levels are increased in colorectal cancer and liver metastases arising secondary to colon cancer. However, although Src protein is increased in colon cancer as early as the adenomatous polyp stage, a role for Src in carcinogenesis has not been established. We developed the c‐SRC transgenic mouse in the C57BL/6 strain to address the issue of carcinogenesis in cells with high levels of Src expression. The transgene was constructed with the human c‐SRC gene downstream of the mouse metallothionein promoter to create zinc inducible gene expression. In these C57BL/6 mice, Src protein was increased in a number of tissues both with and without zinc induction. No additional carcinogenic agent was administered. After 20 months, mice were assessed for tumor development in the liver and GI tract, as well as other organs. Of the mice with the transgene, 15% developed tumors in the liver while no tumors were detected in wild type C57BL/6 mice. A further study was conducted by crossing c‐SRC C57BL/6 mice with p21 nullizygous mice to determine the effect of oncogene expression combined with inactivation of the tumor suppressor gene, p21. Addition of the c‐SRC transgene to the p21−/− background increased tumor formation almost 3‐fold, while it increased metastasis 6‐fold. The data from our study show, for the first time, that Src kinase may play a role in carcinogenesis. © 2008 Wiley‐Liss, Inc.
Development of the treatment attitudes questionnaire in bipolar disorder
Authors: Johnson Sheri L. , Fulford Daniel
Published: March 2008

Despite the success of pharmacotherapy in the management of bipolar disorder, as many as one‐half of those in treatment discontinue their medication over time. Currently, no self‐report measure is available that predicts treatment engagement in bipolar disorder. The goal of the current study was to develop a measure of awareness of symptoms and attitudes toward treatment among those with bipolar disorder. Sixty‐six participants diagnosed with bipolar I disorder on the SCID completed the Treatment Attitudes Questionnaire (TAQ) and were then followed for up to 2 years to assess symptom levels. Medication data were available for 37 participants. Analyses of the TAQ were conducted to examine reliability, predictors of subscales, and how well scores predicted medication and symptom levels over time. Results indicate that previous episodes of depression, but not episodes of mania, correlated with increased scores on the Insight and the Enjoyment of Mania subscales. Scores on the Nonbiological Attributions subscale predicted lower levels of lithium as well as increased depressive symptoms over time. Although the current study includes limited measurement of treatment engagement and a small sample size, this easily administered scale may help treatment planning for those with bipolar disorder. © 2008 Wiley Periodicals, Inc. J Clin Psychol 64: 466–481, 2008.
Parent–child interactions in pediatric bipolar disorder
Authors: Schenkel Lindsay S. , West Amy E. , Harral Erin M. , Patel Nafisa B. , Pavuluri Mani N.
Published: March 2008

Parent–child relationships may have a significant effect on illness characteristics of children with pediatric bipolar disorder (PBD), and these relationships may, in turn, be affected by the child's illness. We characterized maternal reports of parent–child relationships using the five‐factor Parent–Child Relationship Questionnaire (PCRQ) in 60 families (30 PBD youth and 30 matched controls). Data on child proband and parental psychopathology were also obtained. Compared to controls, parent–child relationships in the PBD group were characterized by significantly less warmth, affection, and intimacy, and more quarreling and forceful punishment. Among PBD participants, elevated symptoms of mania, comorbid ADHD, an earlier age of illness onset, living in a single parent home, and the presence of a parental mood disorder were associated with greater parent–child relationship difficulties. These findings have implications for the development of interventions that focus on the quality of parent–child relationships, in addition to symptom management, in the treatment of PBD. © 2008, Wiley Periodicals, Inc. J Clin Psychol 64: 422–437, 2008.
Heme oxygenase‐1 mediates the anti‐inflammatory effect of Curcumin within LPS‐stimulated human monocytes
Authors: Hsu Hsien‐Yeh , Chu Li‐Chieh , Hua Kuo‐Feng , Chao Louis Kuoping
Published: March 2008

Curcumin, a polyphenolic compound derived from plant, regulates heme oxygenase (HO‐1) expression within certain cell types; however, the Curcumin‐mediated signal transduction in the regulation of HO‐1 expression within human monocytes/macrophages is unclear. Herein, we show that Curcumin dose dependently induced HO‐1 expression and HO‐1 activity through the activation of PKCα, PKCδ/ERK1/2, p38α, and PI3‐kinase. In addition, H2O2 release is essential for Curcumin‐mediated ERK1/2 and p38 phosphorylation and HO‐1 expression. Further, Curcumin inhibited LPS‐induced IL‐1 and IL‐6 secretion and blockage of HO‐1 expression/activity by HO‐1 siRNA or HO‐1 inhibitor, SnPP reversed the inhibitory effects of Curcumin on cytokines secretion. HO‐1 over‐expression produced the same inhibitory effects of Curcumin on IL‐1 secretion. Collectively, our results suggest that Curcumin inhibits cytokines secretion within LPS‐stimulated monocytes through a mechanism that involves the action of HO‐1. J. Cell. Physiol. 215: 603–612, 2008. © 2008 Wiley‐Liss, Inc.
Holocene environmental change in the West African Sahel: sedimentological and mineral‐magnetic analyses of lake sediments from Jikariya Lake, northeastern Nigeria
Authors: Wang H. , Holmes J. A. , Street‐Perrott F. A. , Waller M. P. , Perrott R. A.
Published: March 2008

Previous studies have demonstrated long‐term changes in effective moisture in sub‐Saharan Africa. Here, we reconstruct Holocene environments using a ∼7 m lake‐sediment sequence recovered from the northeastern Nigerian Sahel and attempt to distinguish basin‐specific changes from regional climatic variations. The sequence was analysed for sedimentological properties, mineral magnetism and pollen, and dated by 137Cs, 210Pb excess and 14C. Extremely arid conditions of the terminal Pleistocene ended ca. 11 500 cal. BP (calendar years) when climate ameliorated and a lake developed until the occurrence of an arid event leading to lake desiccation at ∼11 200 cal. BP. Following this, climate ameliorated and a water body re‐emerged. Very wet conditions predominated 11 200–5600 cal. BP, followed by drought between 5600 and 5500 cal. BP and a return to moderate humidity from 5500 to 4000 cal. BP. After 4000 cal. BP, a marked deterioration occurred, culminating in lake desiccation at ca. 800 cal. BP. After this time the climate remained generally dry and the re‐emerging lake was shallow. Comparison of these results with other well‐dated sequences in the region demonstrates the importance of basin‐specific influences on the palaeolimnological records in addition to regional climatic controls. Disentangling these different controls, as well as the reconstruction of Holocene climate, therefore requires a multiple‐basin approach. Copyright © 2008 John Wiley & Sons, Ltd.
Local disappearance of bivalves in the Azores during the last glaciation
Authors: Ávila Sérgio P. , Madeira Patrícia , da Silva C. Marques , Cachão Mário , Landau Bernard , Quartau Rui , Martins A. M. de Frias
Published: March 2008

The Pleistocene (Eemian) outcrops of Lagoinhas and Prainha, located at Santa Maria Island (Azores), were investigated and their fossil mollusc content reported. These studies revealed that the last glaciation affected two groups of molluscs: the ‘warm‐guest’ gastropods with West African or Caribbean affinities (e.g. Conus spp., Cantharus variegatus, Bulla amygdala, Trachypollia nodulosa) and shallow bivalve species mainly associated with sandy habitats (Ensis minor, Lucinella divaricata, and probably Laevicardium crassum). In this paper we focus on this group of bivalves, which has since locally disappeared from the Azores. We relate the local disappearance of these bivalves in the Azores with the lack of sand in the shelf. The specific characteristics of the Santa Maria shelf combined with the sea‐level drop during the Weichselian prevented deposition of the lowstand deposits and permitted erosion of the previous ones, leaving the shelf without a sediment cover. Copyright © 2008 John Wiley & Sons, Ltd.
On the effect of ensemble size on the discrete and continuous ranked probability scores
Authors: Ferro Christopher A. T. , Richardson David S. , Weigel Andreas P.
Published: March 2008

Four recent papers have investigated the effects of ensemble size on the Brier score (BS) and discrete ranked probability score (RPS) attained by ensemble‐based probabilistic forecasts. The connections between these papers are described and their results are generalized. In particular, expressions, explanations and estimators for the expected effect of ensemble size on the RPS and continuous ranked probability score (CRPS) are obtained. Copyright © 2008 Royal Meteorological Society
Doppler radar radial wind data in NWP model validation
Authors: Salonen Kirsti , Järvinen Heikki , Järvenoja Simo , Niemelä Sami , Eresmaa Reima
Published: March 2008

Validation of mesoscale numerical weather prediction models calls for high‐resolution observations. Conventional data sources, such as radiosonde data, provide a reliable benchmark but their spatial resolution is insufficient for model validation in the kilometric scale. Doppler radar radial wind observations are used in this study as an alternative data source for model validation. Data assimilation system in general, and observation modelling in particular, are used as a toolbox for validation.

Two versions of the High Resolution Limited Area Model (HIRLAM), which differ only in the formulation of the surface stress direction, are validated over a period of 1 month. The observation minus background (OmB) statistics advocate the merits of using high‐resolution radar data as model validation material. It is demonstrated that subtle differences in model versions due to different parameterization details can be distinguished with high statistical confidence. Copyright © 2008 Royal Meteorological Society
The extreme dependency score: a non‐vanishing measure for forecasts of rare events
Authors: Stephenson D. B. , Casati B. , Ferro C. A. T. , Wilson C. A.
Published: March 2008

Accurate prediction of rare high‐impact events represents a major challenge for weather and climate forecasting. Assessment of the skill at forecasting such events is problematic because of the rarity of such events. Skill scores traditionally used to verify deterministic forecasts of rare binary events, such as the equitable threat score (ETS), have the disadvantage that they tend to zero for vanishingly rare events. This creates the misleading impression that rare events cannot be skilfully forecast no matter which forecasting system is used.

This study presents a simple model for rare binary‐event forecasts and uses it to demonstrate the trivial non‐informative limit behaviour of several often‐used scores such as ETS. The extreme dependency score (EDS) is proposed as a more informative alternative for the assessment of skill in deterministic forecasts of rare events. The EDS has the advantage that it can converge to different values for different forecasting systems and furthermore it does not explicitly depend upon the bias of the forecasting system.

The concepts and scores are demonstrated using an example of 6‐hourly precipitation total Met Office forecasts for Eskdalemuir in Scotland over the period 1998–2003. Copyright © 2008 Royal Meteorological Society; © Crown Copyright 2008. Reproduced with the permission of the Controller of HMSO. Published by John Wiley & Sons, Ltd
Searching for systematic location errors of quantitative precipitation forecasts over the Calabria region
Authors: Tartaglione Nazario , Mariani Stefano , Casaioli Marco , Accadia Christophe , Federico Stefano , Michaelides Silas Chr.
Published: March 2008

This article statistically analyses the location errors of the precipitation patterns forecast by three limited area models, namely the Fifth‐Generation NCAR/Penn State Mesoscale Model (MM5), the QUADRICS BOlogna Limited Area Model (QBOLAM) and the Regional Atmospheric Modelling System (RAMS), over the Calabria region (Italy) for the period October 2000–May 2002. Contiguous rain area (CRA) analysis is the diagnostic tool used to assess and quantify the position errors of the precipitation forecasts with respect to the observed precipitation patterns. Observation gridded analyses were obtained by means of the Barnes algorithm on the available rain gauge observations.

Moreover, an approach to measure the quality of precipitation forecasts routinely by means of a global indicator called CRA Mean Shift (CMS) that summarizes the CRA verification outcomes is proposed. The CMS index would represent a statistical indicator of model quality in forecasting the correct positions of precipitation patterns.

The model's tendency to misplace the forecast precipitation patterns towards a particular direction was tested by using a bootstrap procedure.

All models seem to show statistically poor abilities in forecasting the correct precipitation pattern position over the verification domain considered. As far as the tendency towards a particular direction is concerned, only the RAMS model seems to show a systematic horizontal misplacement of precipitation patterns towards a particular direction. Copyright © 2008 Royal Meteorological Society
Evaluating forecasts of extreme events for hydrological applications: an approach for screening unfamiliar performance measures
Authors: Cloke Hannah L. , Pappenberger Florian
Published: March 2008

Many different performance measures have been developed to evaluate field predictions in meteorology. However, a researcher or practitioner encountering a new or unfamiliar measure may have difficulty in interpreting its results, which may lead to them avoiding new measures and relying on those that are familiar. In the context of evaluating forecasts of extreme events for hydrological applications, this article aims to promote the use of a range of performance measures. Some of the types of performance measures that are introduced in order to demonstrate a six‐step approach to tackle a new measure. Using the example of the European Centre for Medium‐Range Weather Forecasts (ECMWF) ensemble precipitation predictions for the Danube floods of July and August 2002, to show how to use new performance measures with this approach and the way to choose between different performance measures based on their suitability for the task at hand is shown. Copyright © 2008 Royal Meteorological Society
Terminal aerodrome forecast verification in Austro Control using time windows and ranges of forecast conditions
Authors: Mahringer Guenter
Published: March 2008

Terminal aerodrome forecasts (TAFs) are widely used meteorological forecasts for flight planning. Therefore, there is considerable interest in assessing their accuracy, skill and value. TAFs give information about the expected conditions of wind, visibility, significant weather and clouds at airports. Using different types of change groups, the forecaster gives a range of possible values valid for a time interval, the shortest interval being 1 h. A TAF thus contains a range of forecast conditions for each hour.

Point verification has proved to be difficult for TAFs. To ease these difficulties, time and meteorological state constraints are relaxed in the method described in this paper. This is done by verifying two conditions for each hour of the TAF. The highest (or most favourable) observed value is used to score the highest forecast value, and the lowest (or most adverse) observed value is used to score the lowest forecast value. Entries are made accordingly into two contingency tables. The contingency tables are specific for weather element and lead time.

Verification results should give feedback to forecasters. Contingency tables show the strengths and weaknesses of TAF, and displays for individual TAFs are available in the sense of ‘eyeball verification’. For management information, common verification measures for categorical events (such as the Gerrity Score and the Heidke Skill Score) are calculated from the contingency tables. For answering specific customer questions, verification results in respect to certain values of weather elements are available. Copyright © 2008 Royal Meteorological Society
A review with comprehensive data on experimental indirect scalar NMR spin–spin coupling constants across hydrogen bonds
Authors: Alkorta Ibon , Elguero José , Denisov Gleb S.
Published: March 2008

Scalar NMR spin–spin coupling constants across hydrogen bonds are fundamental in structural studies and as test grounds for theoretical calculations. Since they are scattered among many articles of different kinds, it seems useful to collect them in the most comprehensive way. Copyright © 2008 John Wiley & Sons, Ltd.
Study of triacylglycerol polymorphs by nuclear magnetic resonance: effects of temperature and chain length on relaxation parameters
Authors: Adam‐Berret M. , Rondeau‐Mouro C. , Riaublanc A. , Mariette F.
Published: March 2008

It is very important to monitor the characteristics of triacylglycerol crystal network in fats, as these crystals have an impact on many food properties such as texture, sensory taste, and extended shelf life. Although time‐domain NMR (TD‐NMR) is now the reference technique to determine the solid fat index in food, the entire possibilities of this technique are not used. Some NMR studies have been performed to determine its power for the discrimination of polymorphism. In this study, extended investigations proved that TD‐NMR could evaluate triacylglycerol (TA) polymorphism, independently from temperature and chain length. Study of the dipolar interactions through second moment M2, which is characteristic of proton mobility in solid‐state samples, provided a new understanding of the structural organization of crystal molecules. Proton spin–lattice relaxation, which has been proved to be a true probe of polymorphism, has provided information on crystal networks. Combination of the two techniques revealed two very interesting kinds of results, i.e. the presence of a minimum spin–lattice relaxation time T1 for tristearin α, which is a characteristic of a dynamic molecular process, and differences in behavior between long and short chain lengths, both at a molecular and a crystal level. Copyright © 2008 John Wiley & Sons, Ltd.
A recovery‐type error estimator for the extended finite element method based on singular+smooth stress field splitting
Authors: Ródenas J. J. , González‐Estrada O. A. , Tarancón J. E. , Fuenmayor F. J.
Published: March 2008

A new stress recovery procedure that provides accurate estimations of the discretization error for linear elastic fracture mechanic problems analyzed with the extended finite element method (XFEM) is presented. The procedure is an adaptation of the superconvergent patch recovery (SPR) technique for the XFEM framework. It is based on three fundamental aspects: (a) the use of a singular+smooth stress field decomposition technique involving the use of different recovery methods for each field: standard SPR for the smooth field and reconstruction of the recovered singular field using the stress intensity factor K for the singular field; (b) direct calculation of smoothed stresses at integration points using conjoint polynomial enhancement; and (c) assembly of patches with elements intersected by the crack using different stress interpolation polynomials at each side of the crack. The method was validated by testing it on problems with an exact solution in mode I, mode II, and mixed mode and on a problem without analytical solution. The results obtained showed the accuracy of the proposed error estimator. Copyright © 2008 John Wiley & Sons, Ltd.
The Boltzmann equation and its fluid dynamic limits: Numerical studies
Authors: Babovsky Hans
Published: March 2008

We introduce a Boltzmann equation on discrete lattices and demonstrate its applicability for the numerical simulation of flows in the transition regime to fluid dynamics. The application concerns an evaporation condensation where the fluid dynamic flow is ruled by a thin kinetic boundary layer. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Decision diagrams for the exact solution of Markov models
Authors: Miner Andrew S.
Published: March 2008

High‐level models of asynchronous systems can easily produce large Markov chains, whose solution is desired to determine performance measures about the system. Although these Markov chains are typically quite sparse, they can still require an excessive amount of storage space if a traditional, sparse matrix representation is used. This article surveys compact data structures that can be used to generate and store extremely large Markov chains corresponding to a high‐level description. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the convergence for kinetic variational inequality to quasi‐static variational inequality with application to elastic‐plastic systems with hardening
Authors: Petrov Adrien
Published: March 2008

In this note, a priori estimates for the kinetic problem are obtained that imply, that the kinetic solutions converge to the quasi‐static ones, when the size of initial perturbations and the rate of application of the forces tend to 0. An application to three‐dimensional elastic‐plastic systems with hardening is given. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Numerical experiments on a flexible variant of GMRES‐DR
Authors: Giraud Luc , Gratton Serge , Pinel Xavier , Vasseur Xavier
Published: March 2008

The Flexible GMRES (FGMRES [1]) and the GMRES with deflated restarting (GMRES‐DR [2]) methods are two algorithms derived from GMRES [3], that are considered as powerful when solving large non hermitian systems of linear equations. GMRES‐DR is a variant of GMRES with an improved restarting technique that maintains in the Krylov subspace harmonic Ritz vector from the previous restart. In situations where the convergence of restarted GMRES is slow and where the matrix has few eigenvalues close to the origin, this technique has proved very efficient. The new method that we propose is the Flexible GMRES with deflated restarting (FGMRES‐DR [6]), which combines the two above mentioned algorithms in order to yield better performance. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A moving‐mesh splitting scheme for 2‐dimensional quenching problems
Authors: Sheng Q.
Published: March 2008

A novel moving‐mesh adaptive finite difference method is proposed for solving 2‐dimensional quenching differential equations of the form ut = uxx + uyy + (κ – u)–2. Splitting strategies equipped with proper arc‐length adaptations are utilized to achieve the computational efficiency as well as accuracy of the numerical solution of the potentially singular problems. Important results including the monotonicity of the nonlinear finite difference scheme are given. Simulation validations are provided to further demonstrate our conclusions. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Variable transformations in numerical integration
Authors: Sidi Avram
Published: March 2008

We discuss some recent developments in the use of class Sm variable transformations for improving the accuracy of the trapezoidal rule approximations in numerical integration via the trapezoidal rule. These concern optimal choices of m. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Stochastic homogenization on selfsimilar structures
Authors: Soós Anna
Published: March 2008

Stochastic selfsimilar sets and measure have been used extensively to model various physical phenomena. In the following we will use them to generalize the concept of stochastic two‐scale convergence. Using this notion the homogenization theory can be developed for stochastic selfsimilar structures. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Aspects of shape an parameter sensitivity analysis in the theory of porous media
Authors: Barthold Franz‐Joseph , Stieghan Jörg
Published: March 2008

This contribution is concerned with the application of variational shape sensitivity analysis and parameter sensitivity analysis to the theory of porous media. Both areas contribute to structural optimization and other inverse problems like parameter identification. The correct and efficient derivation, implementation and computation of the sensitivities, that are the gradient values of objectives and constraints with respect to different kind of design variables, have a significant influence on the overall performance of the nonlinear programming algorithms applied to the numerical treatment of inverse problems.

The theory of porous media is built upon the mixture of several phases and their interaction using the concept of volume fractions. Thus, a complex continuum mechanical description for each single phase as well as for the whole mixture is used in this approach. This proposal formulates a general viewpoint using an intrinsic formulation in local coordinates which permit a rigorous split of continuum mechanical functions into parts being either geometry or deformation depending. The variational approach to sensitivity analysis is built not only upon this separation but also upon material parameters and yields some general insight into the structure of porous media. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Slow crack growth resistance in resin blends of chromium and metallocene catalyzed ethylene‐hexene copolymers for pipe applications
Authors: García Rafael A. , Carrero A. , Aroca M. , Prieto O. , Domínguez C.
Published: March 2008

A bimodal system has been developed by blending a high density and linear medium density ethylene‐hexene copolymers synthesized with chromium and metallocene catalysts, respectively. The resistance to slow crack growth examined by the Pennsylvania Edge‐Notch Tensile test (PENT test‐ASTM F1473) and the crack opening displacement was determined at 80°C and 2.4 MPa. The effects of molecular and morphological structure on the slow crack growth (SCG) resistance were evaluated, the molecular weight and lamellar thickness being the most critical parameters for this system. The great importance of the short chain branching content and distribution was determined and discussed by SEC‐FTIR. Therefore, two main factors were found determinant in the SCG resistance. On the one hand, the increase of tie molecule density and therefore the continuity in the network formed by crystals and tie molecules and, on the other hand, the short chain branching density increase as the linear medium density ethylene‐hexene copolymer fraction does so. In addition, a morphological analysis of the fracture surface was performed in order to analyze the fracture mechanisms that took place. Differences observed in the fracture surface morphology were related to the molecular and morphological structure. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Multiple sclerosis‐related proteins identified in cerebrospinal fluid by advanced mass spectrometry
Authors: Stoop Marcel P. , Dekker Lennard J. , Titulaer Mark K. , Burgers Peter C. , Sillevis Smitt Peter A. E. , Luider Theo M. , Hintzen Rogier Q.
Published: March 2008

A total of 164 cerebrospinal fluid (CSF) samples taken from neurological patients were classed into four groups according to the clinical diagnosis: multiple sclerosis (MScl, n = 44), clinically isolated syndrome of demyelination (CIS, n = 40), other inflammatory neurological disease (OIND, n = 26) and other neurological disease (OND, n = 54). After tryptic digestion, the samples were measured by MALDI‐TOF MS. Spectra were analyzed using the R‐project software package, in which a peak detection algorithm was developed. Subsequently, the peak lists were compared based on ranked data (non‐parametric). Significant differences were observed in the comparisons of MScl vs. OND and CIS vs. OND. The comparisons of MScl vs. OIND, and CIS vs. OIND showed fewer significant differences. No significant differences were found in comparisons MScl vs. CIS and OIND vs. OND. MScl and CIS had strikingly similar profiles, probably a reflection of common pathological mechanisms. Three differentially expressed proteins in the comparison of MScl vs. OND were identified: chromogranin A, a potential marker for neurodegeneration; and two important factors in complement‐mediated inflammatory reaction, clusterin and complement C3. CSF chromogranin A levels were confirmed to be significantly elevated in the MScl group using an ELISA.
Microsystems for Optical Cell Detection: Near versus Far Field
Authors: Kostner Stefan , Vellekoop Michael J.
Published: March 2008

Optical flow cytometry is a process where physical and (bio‐) chemical parameters of single biological cells can be obtained in a flow‐through setup by optical measurement techniques. Unlike conventional systems, where measurements are conducted in the optical far field, the proposed system senses the cell's optical projection in the near field by using integrated photodiodes. This allows for the attainment of additional parameters, e.g., size and shape, which are usually hidden in the far field. In addition, parameters such as refractive index and absorption of the cell influence the sensor signal. Additionally, with another setup, a different approach is followed to measure similar parameters with external detection using a DVD laser pickup head and a microchannel equipped with a mirror. This low‐cost setup does not measure in the near field, and therefore, is dedicated to different parameters. In this contribution, results from measurements with polystyrene particles and biological cells (yeast and Chinese hamster ovary) are presented and the advantages and limitations of both systems are outlined.
Invega: prolonged‐release paliperidone for schizophrenia
Authors: Chaplin Steve , Livingston Martin
Published: March 2008

Paliperidone (Invega) is a new atypical antipsychotic available as modified‐release tablets for once‐daily administration. Here, Steve Chaplin presents the clinical data relating to its efficacy and adverse affects, and Dr Martin Livingston comments on its place in the treatment of schizophrenia. Copyright © 2008 Wiley Interface Ltd
Current treatment options in the management of migraine
Authors: Fontebasso Manuela
Published: March 2008

A range of effective drug therapies is now available to treat and prevent migraine. Our Drug review details the properties of the current treatment options, followed by a review of prescription data, sources of further information and the Datafile. Copyright © 2008 Wiley Interface Ltd
Amino acid requirement for the high affinity binding of a selected arginine‐rich peptide with the HIV Rev‐response element RNA
Authors: Sugaya Maki , Nishino Norikazu , Katoh Akira , Harada Kazuo
Published: March 2008

The arginine‐rich motif is a class of short arginine‐rich peptides that bind to specific RNA structures that has been found to be a versatile framework for the design and selection of RNA‐binding peptides. We previously identified novel peptides that bind to the Rev‐response element (RRE) RNA of the HIV from an arginine‐rich polypeptide library (ARPL) consisting of a polyarginine (15 mer) randomized at the N‐terminal 10 positions. The selected peptides bound more strongly to the RRE than the natural binding partner, Rev, and contained glutamine residues that were assumed to be important for recognition of the G–A base pair. In addition, the peptides were predicted to bind to the RRE in an α‐helical conformation. In this study, in order to understand the mechanism of the interaction between the RRE and the putative α‐helical glutamine‐containing peptides, the amino acid requirements for high affinity binding were analyzed by a combinatorial approach using a bacterial system for detecting RNA–peptide interactions. A consensus peptide, the DLA peptide, was elucidated, which consists of a single glutamine residue within a polyarginine context with the glutamine residue flanked at specific positions by three nonarginine residues, two of which appear to be important for α‐helix stabilization. In addition, the DLA peptide was found to bind extremely tightly to the RRE with an affinity 50‐fold higher than that of the Rev peptide as determined by a gel shift assay. A working model for the interaction of the DLA peptide to the RRE is proposed, which should aid in the development of peptide‐based drugs that inhibit HIV replication, as well as in our understanding of polypeptide–RNA interactions. Copyright © 2008 European Peptide Society and John Wiley & Sons, Ltd.
Optical characterization of rocksalt Pb1–xSnx Te alloys
Authors: Dantas Nilton Souza , Arwin Hans , Nzulu Gabriel , de Oliveira Rappl Paulo Henrique , da Silva Antônio Ferreira , Persson Clas
Published: March 2008

The optical properties in terms of dielectric function ϵ (ħω) = ϵ1(ħω) + iϵ2(ħω) of rocksalt Pb1–x Snx Te alloys (0 ≤ x ≤ 1) are investigated experimentally by spectroscopic ellipsometry and theoretically by first‐principles electronic band structure calculation. We find a strong optical response in the 0.5–2.0 eV region arising from optical absorption around the LW‐line of the Brillouin zone. The response peak of the imaginary part of the dielectric functions at E = 1.6–1.8 eV shifts towards lower energies for high Sn compositions as a consequence of narrower W‐point band‐gap Eg(W) for the Sn‐rich alloys. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Angle‐resolved Mueller polarimeter using a microscope objective
Authors: Ben Hatit S. , Foldyna M. , De Martino A. , Drévillon B.
Published: March 2008

A new Mueller polarimeter based on liquid crystals and a microscope objective is presented for the characterization of diffraction gratings in a conical diffraction mounting. Fast measurements of complete Mueller matrices over a range of polar angles ϑ (0–60°) and azimuthal angles φ (0–360°) are achieved without mechanical movements. The polarization states generator and analyzer are based on nematic liquid crystals. The angular range is achieved through focalization of light over the measured sample with a microscope objective of high numerical aperture and imaging of the objective's back Fourier plane on a CCD. Results on isotropic samples and diffraction gratings are shown. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characterization of Si nanorods by spectroscopic ellipsometry with efficient theoretical modeling
Authors: Hsu Shih‐Hsin , Liu En‐Shao , Chang Yia‐Chung , Hilfiker James N. , Kim Young Dong , Kim Tae Jung , Lin Chun‐Jung , Lin Gong‐Ru
Published: March 2008

Spectroscopic ellipsometry (SE) is applied to characterize Si columnar nanostructures. By employing effective medium approximation (EMA) theory, Si nanorods are treated as a graded layer with each sub‐layer modeled as a mixture of Si and voids with varying porosity fraction. In addition, the rigorous coupled‐wave analysis and finite‐element Green's function method were used in modeling Si nanorods as a stack of disks with varying diameters and thicknesses, and the calculations are in satisfactory agreement with the measurement results. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)