bluuebunny/crossref_metadata_2025 huggingface dataset:
Differential parental transmission of markers in RUNX2 among cleft case‐parent trios from four populations
Authors: Sull Jae Woong , Liang Kung‐Yee , Hetmanski Jacqueline B. , Fallin Margaret Daniele , Ingersoll Roxann G. , Park Jiwan , Wu‐Chou Yah‐Huei , Chen Philip K. , Chong Samuel S. , Cheah Felicia , Yeow Vincent , Park Beyoung Yun , Jee Sun Ha , Jabs Ethylin Wang , Redett Richard , Jung Euiju , Ruczinski Ingo , Scott Alan F. , Beaty Terri H.
Published: March 2008

Isolated cleft lip with or without cleft palate (CL/P) is among the most common human birth defects, with a prevalence around 1 in 700 live births. The Runt‐related transcription factor 2 (RUNX2) gene has been suggested as a candidate gene for CL/P based largely on mouse models; however, no human studies have focused on RUNX2 as a risk factor for CL/P. This study examines the association between markers in RUNX2 and isolated, nonsyndromic CL/P using a case‐parent trio design, while considering parent‐of‐origin effects. Case‐parent trios from four populations (77 from Maryland, 146 from Taiwan, 35 from Singapore, and 40 from Korea) were genotyped for 24 single nucleotide polymorphisms (SNPs) in the RUNX2 gene. We performed the transmission disequilibrium test on individual SNPs. Parent‐of‐origin effects were assessed using the transmission asymmetry test and the parent‐of‐origin likelihood ratio test (PO‐LRT). When all trios were combined, the transmission asymmetry test revealed a block of 11 SNPs showing excess maternal transmission significant at the P<0.01 level, plus one SNP (rs1934328) showing excess paternal transmission (P=0.002). For the 11 SNPs showing excess maternal transmission, odds ratios of being transmitted to the case from the mother ranged between 3.00 and 4.00. The parent‐of‐origin likelihood ratio tests for equality of maternal and paternal transmission were significant for three individual SNPs (rs910586, rs2819861, and rs1934328). Thus, RUNX2 appears to influence risk of CL/P through a parent‐of‐origin effect with excess maternal transmission. Genet. Epidemiol. 2008. © 2008 Wiley‐Liss, Inc.
Photocycloaddition Reactions of 5,5‐Dimethyl‐3‐(3‐methylbut‐3‐en‐1‐ynyl)cyclohex‐2‐en‐1‐one
Authors: Inhülsen Inga , Kopf Jürgen , Margaretha Paul
Published: March 2008

The title cyclohexenone 1d undergoes photodimerization selectively at the exocyclic CC bond to give a 1 : 1 mixture of 1,2‐dialkynyl‐1,2‐dimethylcyclobutanes 6 and 7. On irradiation in the presence of 2,3‐dimethylbuta‐1,3‐diene, 1d affords bicyclo[8.4.0]tetradeca‐1,2,3,7‐tetraen‐11‐one 9. This – formal – (6+4)‐cycloadduct undergoes quantitative isomerization to 3‐cycloheptadienyl‐2,5,5‐trimethylcyclohex‐2‐enone 11 on treatment with basic silica gel.
Stability of 7,8‐Dihydropterins in Air‐Equilibrated Aqueous Solutions
Authors: Dántola M. Laura , Vignoni Mariana , Capparelli Alberto L. , Lorente Carolina , Thomas Andrés H.
Published: March 2008

6‐Substituted 7,8‐dihydropterins (=2‐amino‐7,8‐dihydropteridin‐4(1H)‐ones) are heterocyclic compounds that occur in a wide range of living systems and participate in relevant biological functions. In air‐equilibrated aqueous solutions, these compounds react with dissolved O2 (autooxidation). The rates of these reactions as well as the products formed strongly depend on the chemical structure of the substituents. 7,8‐Dihydro‐6‐methylpterin and 7,8‐dihydro‐6,7‐dimethylpterin that bear electron‐donor groups as substituents are the most reactive derivatives and undergo oxidation of the pterin moiety to yield the corresponding oxidized derivatives (6‐methylpterin and 6,7‐dimethylpterin, resp.). The oxidations of 7,8‐dihydrobiopterin, 7,8‐dihydroneopterin, and 7,8‐dihydrofolic acid are slower, and they yield 7,8‐dihydroxanthopterin as the main product. 7,8‐Dihydroxanthopterin, 6‐formyl‐7,8‐dihydropterin, and sepiapterin are rather stable, and their consumption in air‐equilibrated solutions is negligible for several days. The pseudo‐first‐order rate constants of the reactions between these compounds and O2 at 25° and 40° are reported. The biological implications of the results obtained are also discussed.
Diels–Alder Additions, Ene Reactions, and Condensations of 4‐(Acylamino)‐5‐nitrosopyrimidines – Synthesis of 8‐Substituted Guanines and of 6‐Substituted Pteridinones
Authors: Steinlin Thomas , Vasella Andrea
Published: March 2008

4‐(Acylamino)‐5‐nitrosopyrimidines react either by a reductive condensation to provide 8‐substituted guanines, or by a Diels–Alder cycloaddition, or an ene reaction, to provide 6‐substituted pteridinones, depending on the nature of the acyl group and the reaction conditions. Experimental details are provided for the transformation of (acylamino)‐nitrosopyrimidines to 8‐substituted guanines, and the scope of the reaction is further demonstrated by transforming the trifluoro acetamide 25 to the 8‐(trifluoromethyl)guanine (27), and the N,N′‐bis(nitrosopyrimidinyl)‐dicarboxamide 29 to the (R,R)‐1,2‐di(guan‐8‐yl)ethane‐1,2‐diol (32). An intramolecular Diels–Alder reaction of the N‐sorbyl (=N‐hexa‐2,4‐dienoyl) nitrosopyrimidine 10, followed by a spontaneous elimination to cleave the N,O bond of the initial cycloaddition product provided the pteridinones 14 or 15, characterized by a (Z)‐ or (E)‐3‐hydroxyprop‐1‐enyl group at C(6). Treatment of 10 with Ph3P led to the C(8)‐penta‐1,3‐dienyl‐guanine 18. The ene reaction of the N‐crotonyl (=N‐but‐2‐enoyl) nitrosopyrimidine 19 provided the 6‐vinyl‐pteridinone 20a that dimerized readily to 21a, while treatment of 19 with Ph3P led in high yield to 8‐(prop‐1‐enyl)guanine (23). The structure of the dimer 21 was established by X‐ray analysis of its bis(N,N‐dimethylformamidine) derivative 21b. The crystal structure of the nitroso amide 10 is characterized by two molecules in the centrosymmetric unit cell. Intermolecular H‐bonds connect the amino group to the amide carbonyl and to N(1). The crystalline bis(purine) 30 forms a left‐handed helix with four molecules per turn and a pitch of 30.2 Å.
Three New Glycosides from the Stems of Miliusa balansae
Authors: Lei Yu , Wu Li‐Jun , Shi Hai‐Ming , Tu Peng‐Fei
Published: March 2008

Three new glycosides with the same saccharides, namely miliusoside A (1), miliusoside B (2), and miliusoside C (3), together with five known compounds were isolated from the stems of Miliusa balansae. Their structures were elucidated on the basis of detailed spectroscopic analysis and by comparison with the spectra of related model compounds. There was a rarely encountered α‐D‐apiose moiety occurring in all new compounds.
On the Most Powerful Chemical Traps for Bis(methoxycarbonyl)carbene (=2‐Methoxy‐1‐(methoxycarbonyl)‐2‐oxoethylidene)
Authors: Shevchenko Vladimir V. , Zhegalova Natalya G. , Borzenko Andey O. , Nikolaev Valerij A.
Published: March 2008

The efficiency and validity of different chemical substrates for trapping bis(methoxycarbonyl)carbene (=2‐methoxy‐1‐(methoxycarbonyl)‐2‐oxoethylidene; 1) is dependent on the conditions of carbene generation. On conventional photolysis of dimethyldiazomalonate (=2‐diazopropanedioic acid dimethyl ester; 2) by long‐wave UV light (through a Pyrex filter, λ>290 nm), the most powerful trap for carbene 1 in the series of substrates Me2S, MeOH, cyclohexane, and pyridine is Me2S (with an efficiency ratio of ca. 6 : 4 : 2 : 1, resp.). When short‐wave decomposition of diazomalonate 2 is employed (through a quartz filter, λ>210 nm), more reliable and useful chemical traps for bis(methoxycarbonyl)carbene (1) are pyridine and cyclohexane, whose adducts with 1 are rather stable under short‐wave‐irradiation conditions. Application of alcohols for the trapping of 1 proves to be preferential when simultaneous monitoring of carbene and oxoketene formation during photolysis is necessary.
Synthesis and Conformational Analysis of Pentapeptides Containing Enantiomerically Pure 2,2‐Disubstituted Glycines
Authors: Brun Kathrin A. , Linden Anthony , Heimgartner Heinz
Published: March 2008

The synthesis and conformational analysis of model pentapeptides with the sequence Z‐Leu‐Aib‐Xaa‐Gln‐Valol is described. These peptides contain two 2,2‐disubstituted glycines (α,α‐disubstituted α‐amino acids), i.e., Aib (aminoisobutyric acid), and a series of unsymmetrically substituted, enantiomerically pure amino acids Xaa. These disubstituted amino acids were incorporated into the model peptides via the ‘azirine/oxazolone method’. Conformational analysis was performed in solution by means of NMR techniques and, in the solid state, by X‐ray crystallography. Both methods show that the backbones of these model peptides adopt helical conformations, as expected for 2,2‐disubstitued glycine‐containing peptides.
Variability of shallow overland flow velocity and soil aggregate transport observed with digital videography
Authors: Sidorchuk A. , Schmidt J. , Cooper G.
Published: March 2008

Field experiments at Tiramoana station 30 km north of Christchurch, New Zealand using an erosion plot 16·5 m long, 0·6 m wide, and with a slope of 14–14·5° on rendzina soil aimed to measure the variability of flow velocity and of soil aggregates transport rate in shallow overland flow. Discharge/cross‐section area ratio was used to estimate mean velocity, and high‐speed digital video camera and image analysis provided information about flow and sediment transport variability. Six flow runs with 0·5–3·0 L s−1 discharges were supercritical with Froude numbers close to or more than 1. Mean flow velocity followed Poiseuille law, float numbers were more than 1·5 and hydraulic resistance was an inverse proportional function of the Reynolds number, which is typical for laminar flows. Hence actual velocity varied through time significantly and the power spectrum was of ‘red‐noise’, which is typical for turbulent flow. Sediment transport rates had even higher variability, and soil aggregates transport was a compound Poisson process. Copyright © 2008 John Wiley & Sons, Ltd.
Use of Nash's IUH and DEMs to identify the parameters of an unequal‐reservoir cascade IUH model
Authors: Li Chaoqun , Guo Shenglian , Zhang Wenhua , Zhang Jun
Published: March 2008

Under the assumption that hydrograph generation was affected by n linear reservoirs with the same value of storage coefficient k, Nash proposed the formulation of the Instantaneous Unit Hydrograph (IUH), which has been widely used in rainfall–runoff simulation and flood forecasting. However, the assumption of the parameter k having the same value in all reservoirs is obviously unphysical as it results in the estimated value of n not being integral. In this study, for parameter n integral, the different k value for each reservoir was derived using the Laplace transform and developing a general rule for the equation of the IUH of any order. The relationship between parameter k and the slope of the river channel estimated using digital elevation model (DEM) data is established, the parameter estimation procedures are given. As in most unit hydrograph studies, only isolated storm events are considered here. Seventeen flood events in three catchments were selected for the case studies. Application results show that the proposed method is slightly better than Nash's IUH with higher model efficiency and smaller absolute relative errors. This work provides a new methodology for the formulation of the IUH. Copyright © 2008 John Wiley & Sons, Ltd.
Runoff curve numbers for steep hillslopes with natural vegetation in semi‐arid tropical highlands, northern Ethiopia
Authors: Descheemaeker Katrien , Poesen Jean , Borselli Lorenzo , Nyssen Jan , Raes Dirk , Haile Mitiku , Muys Bart , Deckers Jozef
Published: March 2008

Daily runoff from 27 plots (5 m × 2 m) recorded during two rainy seasons in the Tigray highlands (Ethiopia) were analysed together with daily rainfall to calculate runoff curve numbers for hillslopes covered by semi‐natural vegetation in varying stages of vegetation restoration. Curve number model parameters were derived using a least squares fitting procedure on the collected rainfall–runoff datasets. Curve numbers varied from 29 to 97. Land use type was an important explanatory factor for the variation in curve numbers, whereas hydrologic soil group was not. Curve numbers were negatively correlated with vegetation cover. Taking into account antecedent soil moisture conditions did not improve runoff prediction using the curve number method. As runoff prediction was less accurate in areas with low curve numbers, two separate regression functions relating curve numbers with vegetation cover were proposed for different land use types. Copyright © 2008 John Wiley & Sons, Ltd.
Storm‐event rainfall–runoff modelling approach for ungauged sites in Taiwan
Authors: Wang Yu‐Chi , Chen Shien‐Tsung , Yu Pao‐Shan , Yang Tao‐Chang
Published: March 2008

This work develops a top‐down modelling approach for storm‐event rainfall–runoff model calibration at unmeasured sites in Taiwan. Twenty‐six storm events occurring in seven sub‐catchments in the Kao‐Ping River provided the analytical data set. Regional formulas for three important features of a streamflow hydrograph, i.e. time to peak, peak flow, and total runoff volume, were developed via the characteristics of storm event and catchment using multivariate regression analysis. Validation of the regional formulas demonstrates that they reasonably predict the three features of a streamflow hydrograph at ungauged sites. All of the sub‐catchments in the study area were then adopted as ungauged areas, and the three streamflow hydrograph features were calculated by the regional formulas and substituted into the fuzzy multi‐objective function for rainfall–runoff model calibration. Calibration results show that the proposed approach can effectively simulate the streamflow hydrographs at the ungauged sites. The simulated hydrographs more closely resemble observed hydrographs than hydrographs synthesized using the Soil Conservation Service (SCS) dimensionless unit hydrograph method, a conventional method for hydrograph estimation at ungauged sites in Taiwan. Copyright © 2008 John Wiley & Sons, Ltd.
Periodic changes of stream flow in the last 40 years in Tarim River Basin, Xinjiang, China
Authors: Chen Yaning , Pang Zhonghe , Hao Xingming , Xu Changchun , Chen Yapeng
Published: March 2008

Using the annual runoff series for the last 40 years from the Tarim River Basin, their periodic properties were analysed and their future trends predicted. Runoff data were collected at five hydrological gauging stations in the three main branches of the Tarim River. An extrapolation method and variance analysis were used to identify periods in annual runoff, and a trend superposition model to predict future changes. Results show that, there is a common period of 17 years in annual runoff changes for all three branches, with Hotan River showing an additional period of 10 years. Based on this trend, it is suggested that the annual runoff of the Tarim River should decrease in the period of 2006–2008, but increase in year 2009, and the flow may possibly begin to decrease significantly in year 2010. The long term trend of runoff in Tarim Basin has followed the global prediction of GCMs, i.e. began to increase in accordance with global increase of air temperature and precipitation in 1990. However, it has shown a local feature of uneven changes among the head streams in the same basin, which needs to be further investigated. Copyright © 2008 John Wiley & Sons, Ltd.
Apatite‐mineralized polycaprolactone nanofibrous web as a bone tissue regeneration substrate
Authors: Yu Hye‐Sun , Jang Jun‐Hyeog , Kim Tae‐Il , Lee Hae‐Hyoung , Kim Hae‐Won
Published: March 2008

Degradable synthetic polymers with a nanofibrous structure have shown great promise in populating and recruiting cells for the reconstruction of damaged tissues. However, poor cell affinity and lack of bioactivity have limited their potential usefulness in bone regeneration. We produced polymeric nanofiber poly(ε‐caprolactone) (PCL) with its surface mineralized with bone‐like apatite for use as bone regenerative and tissue engineering matrices. PCL was first electrospun into a nanofibrous web, and the surface was further mineralized with apatite following a series of solution treatments. The surface of the mineralized PCL nanofiber was observed to be almost fully covered with nanocrystalline apatites. Through mineralization, the wettability of the nanofiber matrix was greatly improved. Moreover, the murine‐derived osteoblastic cells were shown to attach and grow actively on the apatite‐mineralized nanofibrous substrate. In particular, the mineralized PCL nanofibrous substrate significantly stimulated the expression of bone‐associated genes, including Runx2, collagen type I, alkaline phosphatase, and osteocalcin, when compared with the pure PCL nanofiber substrate without mineralization. The currently developed polymer nanofibrous web with the bioactive mineralized surface is considered to be potentially useful as bone regenerative and tissue engineering matrices. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Human osteoblastic cell response to a Ca‐ and P‐enriched titanium surface obtained by anodization
Authors: Franco Rosemeire de Lordo , Chiesa Roberto , Beloti Marcio Mateus , de Oliveira Paulo Tambasco , Rosa Adalberto Luiz
Published: March 2008

The aim of the present study was to evaluate the in vitro osteogenic potential of subcultured human osteoblastic cells derived from alveolar bone on a titanium (Ti) surface produced by an anodized alkali treatment (BSP‐AK). Primary osteoblastic cells were subcultured on BSP‐AK and machined Ti discs (control) and grown for periods of up to 21 days under osteogenic conditions. Morphologic and biochemical methods were used to assess important parameters of in vitro bone‐like tissue formation. Although no major differences were observed between the BSP‐AK and the control Ti surface in terms of cell attachment and mineralized matrix formation, a significant increase in cell population, ALP activity, and collagen content was detected in cultures on BSP‐AK surface. Our results demonstrate that human osteoblastic cells are sensitive to the BSP‐AK‐modified Ti surface during the transitional stage between the end of the proliferative phase and the onset of the differentiation/matrix maturation ones. Together with the good mechanical properties exhibited by the Ca‐ and P‐ coating, our findings suggest that BSP‐AK treatment could be useful for the development of a new surface for dental and orthopedic implants. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
correlates of high expressed emotion attitudes among parents of bipolar adolescents
Authors: Coville Allison L. , Miklowitz David J. , Taylor Dawn O. , Low Kathryn G.
Published: March 2008

High expressed emotion (EE) attitudes among parents are associated with an increased likelihood of relapse among bipolar patients, but the origins of these attitudes are unclear. This study examined characteristics of bipolar disorder in adolescents that might be associated with high EE attitudes among parents. We hypothesized that an earlier onset of mood disorder and greater current illness severity would predict higher levels of criticism and emotional overinvolvement among parents. Demographic, diagnostic, and EE data were collected from interviews with parents of 44 bipolar adolescents (mean age 14.5 yrs.). Current illness severity and functioning were not associated with high‐EE attitudes. Parents of girls, however, were more likely to be high in criticism than parents of boys. Parents of girls expressed more critical comments when the child had an adolescent compared to a childhood onset of bipolar disorder, whereas the reverse pattern was evident among parents of boys. We encourage prospective investigations of the developmental correlates of parental EE attitudes in larger, more heterogeneous samples of bipolar adolescents and children. © 2008, Wiley Periodicals, Inc. J Clin Psychol 64: 438–449, 2008.
A qualitative assessment of microclimatic perturbations in a tunnel
Authors: Salve Rohit , Krakauer Nir Y. , Kowalsky Michael B. , Finsterle Stefan
Published: March 2008

Understanding microclimate dynamics in tunnels is important for designing, operating, and maintaining underground facilities. For example, for the geological disposal of radioactive materials, condensation of vapour should be minimized as liquid water can accelerate waste package corrosion and radionuclide release. While microclimate dynamics are known to be dominated by the advection of heat and moisture, additional factors may also be important, such as the presence of fractures or faults. We present data collected using a relatively inexpensive method that is under development to assess microclimatic perturbations underground. By combining standard temperature and relative humidity sensors with low‐cost sensors designed to detect changes in water content, we were able to infer microclimate dynamics along a tunnel at the proposed geological repository at Yucca Mountain, Nevada. We observed significant differences in the pattern of condensation in a faulted zone relative to that of a non‐faulted zone, suggesting that hydrogeologic features have to be accounted for when evaluating the microclimate dynamics of excavated cavities in fractured, partially saturated rocks. Published in 2008 by John Wiley & Sons, Ltd.
Fuzzy verification of high‐resolution gridded forecasts: a review and proposed framework
Authors: Ebert Elizabeth E.
Published: March 2008

High‐resolution forecasts from numerical models can look quite realistic and provide the forecaster with very useful guidance. However, when verified using traditional metrics they often score quite poorly because of the difficulty of predicting an exact match to the observations at high resolution. ‘Fuzzy’ verification rewards closeness by relaxing the requirement for exact matches between forecasts and observations. The key to the fuzzy approach is the use of a spatial window or neighbourhood surrounding the forecast and/or observed points. The treatment of the data within the window may include averaging (upscaling), thresholding, or generation of a PDF, depending on the particular fuzzy method used and its implicit decision model concerning what makes a good forecast. The size of the neighbourhood can be varied to provide verification results at multiple scales, thus allowing the user to determine at which scales the forecast has useful skill.

This article describes a framework for fuzzy verification that incorporates several fuzzy verification methods. It is demonstrated on a high‐resolution precipitation forecast from the United Kingdom (UK) and the results interpreted to show the additional information that can be gleaned from this approach. Copyright © 2008 Royal Meteorological Society
A multi‐model/multi‐analysis limited area ensemble: calibration issues
Authors: Marrocu Marino , Chessa Piero A.
Published: March 2008

In this paper four different post‐processing techniques: the Bayesian model averaging (BMA), the ensemble model output statistics (EMOS) with a variant known as EMOS+ and a new dressing kernel (DRESS) are applied and compared, in a pre‐operational context, to calibrate a mesoscale multi‐model multi‐analysis ensemble. The ensemble makes use of three different limited area models (Bologna Limited Area Model (BOLAM), MM5 and RAMS), one of them used twice with different setups, fed with two sets of analysis and boundary conditions obtained from the European Centre for Medium‐Range Weather Forecasts (ECMWF) and National Centers for Environmental Prediction (NCEP) general circulation models. The resulting ensemble of eight members was run for a period of 6 months (from October 2002 to April 2003) in a Euro–Atlantic domain. The forecast was validated against 2 m temperature measured at 21 meteorological stations scattered across Sardinia (Italy). For each method the calibration ability was assessed evaluating the flatness of the rank histogram, the coverage of the expected forecast intervals and the width of the associated probability distribution function. Results show that BMA and DRESS are the best in improving the calibration of the raw ensemble whereas EMOS and EMOS+ have proven worse, with the latter marginally better. Copyright © 2008 Royal Meteorological Society
On the use of the intensity‐scale verification technique to assess operational precipitation forecasts
Authors: Csima Gabriella , Ghelli Anna
Published: March 2008

The article describes the attempt to include the intensity‐scale technique introduced by Casati et al. (2004) into a set of standardized verifications used in operational centres. The intensity‐scale verification approach accounts for the spatial structure of the forecast field and allows the skill to be diagnosed as a function of the scale of the forecast error and intensity of the precipitation events. The intensity‐scale method has been used to verify two different resolutions of the European Centre for Medium‐Range Weather Forecasts (ECMWF) operational quantitative precipitation forecast (QPF) over France, and to compare the performance of the ECMWF and the Hungarian Meteorological Service operational model (ALADIN) forecasts, run over Hungary. Two case studies have been introduced, which show some interesting insight into the spatial scale of the error. The distribution of daily skill score for an extended period of time is also presented. The intensity‐scale technique shows that the forecasts in general exhibit better skill for large‐scale events, and lower skill for small‐scale and intense events. In the paper, it is mentioned how some of the stringent assumptions on the domain over which the method can be applied, and the availability of the matched forecasts and observations, can limit its usability in an operational environment. Copyright © 2008 Royal Meteorological Society
How much does simplification of probability forecasts reduce forecast quality?
Authors: Doblas‐Reyes F. J. , Coelho C. A. S. , Stephenson D. B.
Published: March 2008

Probability forecasts from an ensemble are often discretized into a small set of categories before being distributed to the users. This study investigates how such simplification can affect the forecast quality of probabilistic predictions as measured by the Brier score (BS). An example from the European Centre for Medium‐Range Weather Forecasts (ECMWF) operational seasonal ensemble forecast system is used to show that the simplification of the forecast probabilities reduces the Brier skill score (BSS) by as much as 57% with respect to the skill score obtained with the full set of probabilities issued from the ensemble. This is more obvious for a small number of probability categories and is mainly due to a decrease in forecast resolution of up to 36%. The impact of the simplification as a function of the ensemble size is also discussed. The results suggest that forecast quality should be made available for the set of probabilities that the forecast user has access to as well as for the complete set of probabilities issued by the ensemble forecasting system. Copyright © 2008 Royal Meteorological Society
Understanding forecast verification statistics
Authors: Mason S. J.
Published: March 2008

Although there are numerous reasons for performing a verification analysis, there are usually two general questions that are of interest: are the forecasts good, and can we be confident that the estimate of forecast quality is not misleading? When calculating a verification score, it is not usually obvious how the score can answer either of these questions. Some procedures for attempting to answer the questions are reviewed, with particular focus onp‐values and confidence intervals.P‐values are shown to be rather unhelpful in answering either question, especially when applied to probabilistic verification scores, and confidence intervals are to be preferred. However, confidence intervals cannot reveal biases in the value of a score that arises from an inadequate experimental design for testing on truly out‐of‐sample observations. Some specific problems with cross validation are highlighted. Finally, in the interests of increasing the insight into forecast strengths and weaknesses and in pointing towards methods for improving forecast quality, a plea is made for a more discriminating selection of verification procedures than has been adopted to date. Copyright © 2008 Royal Meteorological Society
Forecast verification: current status and future directions
Authors: Casati B. , Wilson L. J. , Stephenson D. B. , Nurmi P. , Ghelli A. , Pocernich M. , Damrath U. , Ebert E. E. , Brown B. G. , Mason S.
Published: March 2008

Research and development of new verification strategies and reassessment of traditional forecast verification methods has received a great deal of attention from the scientific community in the last decade. This scientific effort has arisen from the need to respond to changes encompassing several aspects of the verification process, such as the evolution of forecasting systems, or the desire for more meaningful verification approaches that address specific forecast user requirements. Verification techniques that account for the spatial structure and the presence of features in forecast fields, and which are designed specifically for high‐resolution forecasts have been developed. The advent of ensemble forecasts has motivated the re‐evaluation of some of the traditional scores and the development of new verification methods for probability forecasts. The expected climatological increase of extreme events and their potential socio‐economical impacts have revitalized research studies addressing the challenges concerning extreme event verification. Verification issues encountered in the operational forecasting environment have been widely discussed, verification needs for different user communities have been identified, and models to assess the forecast value for specific users have been proposed. Proper verification practice and correct interpretation of verification statistics has been extensively promoted with recent publications and books, tutorials and workshops, and the development of open‐source software and verification tools. This paper addresses some of the current issues in forecast verification, reviews some of the most recently developed verification techniques, and provides recommendations for future research. Copyright © 2008 Royal Meteorological Society and Crown in the right of Canada.
The impenetrable hedge: a note on propriety, equitability and consistency
Authors: Jolliffe Ian T.
Published: March 2008

In weather and climate forecasting, hedging is said to occur whenever a forecaster's judgement and the forecast differ, and it is usually taken as evident that hedging is undesirable. Forecasts are often judged by computing a verification measure or score. A number of different scores is available in most circumstances, and to choose between them, various desirable properties of scores have been defined. It is generally accepted that it is undesirable to use a score for which hedging can improve the score or its expected value. Three ‘desirable’ properties of scores are linked to the idea that hedging should be avoided, namely propriety, equitability and consistency. It is fair to say that none of these properties is fully understood. The aim of this article is to provide some clarification and new insights, as well as some historical background. Nearly as many questions are raised as are answered. Copyright © 2008 Royal Meteorological Society
Seasonal forecasting of Ethiopian spring rains
Authors: Diro G. T. , Black E. , Grimes D. I. F.
Published: March 2008

Reliable prediction of rainfall in advance of the rainy season would have enormous social and economic benefits to countries such as Ethiopia that depend on rain‐fed agriculture. Moreover, the development of statistical seasonal forecasting models provides insights into important scientific problems such as the predictability of rainfall, the large‐scale controls on rainfall, and the teleconnections with tropical and extra‐tropical processes. This article describes the development of statistical seasonal forecasts of the Ethiopian spring rains. Because of the spatial variation in both the interannual variability and the annual cycle of rainfall, Ethiopia was divided into five homogeneous rainfall zones, and separate forecasts were developed for each zone. Two techniques (multiple linear regression (MLR) and linear discriminant analysis (LDA)) were applied to four sets of predictors (selection by either stepwise regression or discriminant analysis either including or excluding the contemporaneous season). All the forecasts had more skill than either a random or climatological forecast. The method of selecting predictors and developing the models was found to have surprisingly little impact on forecast skill. Interestingly, including contemporaneous SST did not always lead to a significant increase in skill. Comparison between the skill of the forecasts in different zones shows that the models had most skill in the southern and eastern parts of Ethiopia. For all forecasts, the extreme years (very rainy and very dry) were more reliably forecast than the average years. Copyright © 2008 Royal Meteorological Society
Accounting for the effect of observation errors on verification of MOGREPS
Authors: Bowler Neill E.
Published: March 2008

A number of articles have looked at the effect of observation errors on verification statistics. In this article, those methods are brought together in order to assess the importance of observation errors on verification statistics for the Met Office short‐range ensemble prediction system (MOGREPS).

The results indicate that the effect of observation errors is substantial–reducing the apparent skill of the forecast system by around 1 day in forecast lead time. The effect of observation errors is typically largest at short lead times when forecast errors are smallest. © Crown Copyright 2008. Reproduced with the permission of the Controller of HMSO. Published by John Wiley & Sons, Ltd
A spatial verification method applied to the evaluation of high‐resolution ensemble forecasts
Authors: Marsigli Chiara , Montani Andrea , Paccangnella Tiziana
Published: March 2008

The verification of ensemble systems is being operationally carried out in several meteorological centres. However, the main operational ensemble systems have a coarser spatial resolution with respect to the deterministic runs. Only recently, high‐resolution limited‐area ensembles have started to be run on a regular basis. Their verification requires combining the usual probabilistic evaluation with the statistical verification techniques which are being developed for high‐resolution model forecasts (1–10 km). These techniques permit to evaluate a deterministic forecast in a probabilistic manner, by taking into account the spatio‐temporal distribution of the forecast at different scales.

In this work, a spatial verification technique, called ‘distributional method’, is used to verify the Consortium for Small‐scale MOdeling Limited‐area Ensemble Prediction System (COSMO–LEPS) ensemble system, a mesoscale ensemble with 10 km horizontal resolution. The system is mainly designed to give probabilistic assistance in the forecast of severe weather, in particular of intense precipitation possibly leading to floods, hence verification is focused on the ability of the system in forecasting precipitation at high spatial resolution. The methodology is based on a comparison of forecasts and observations in terms of some parameters of their distributions, evaluated after the values are aggregated over boxes of selected size. In particular, performances in terms of average, a few percentiles and maximum forecast value in a box are considered.

The system is compared against European Centre for Medium‐Range Weather Forecasts Ensemble Prediction System (ECMWF EPS), addressing the issues of an intercomparison between a higher‐resolution smaller‐size ensemble and a lower‐resolution larger‐size one. Results show that when the forecast of the average amount of precipitation over an area is concerned, COSMO–LEPS is more skilful than the Ensemble Prediction System (EPS) only from the resolution point of view. Therefore, although not properly calibrated, it is more capable of distinguishing between events and non‐events, especially for moderate and high precipitation. Furthermore, COSMO–LEPS has skill in forecasting the occurrence of precipitation peaks over an area, irrespective of the exact location.

The analysis of the score behaviour as a function of the distribution parameter shows that EPS has the maximum skill in reproducing the central part of the observed precipitation distribution over an area of about 10 000 km2, while COSMO–LEPS is more skilful in reproducing the tail of the observed precipitation distribution.

The problem of the predictability of precipitation at different spatial scales is also investigated, showing the role of different system resolutions. Copyright © 2008 Royal Meteorological Society
The accuracy of weather forecasts for Melbourne, Australia
Authors: Stern Harvey
Published: March 2008

An analysis of the accuracy, and trends in the accuracy, of medium‐range weather forecasts for Melbourne, Australia, is presented. The analysis shows that skill is evident in forecasts of temperature, rainfall, and qualitative descriptions of expected weather up to 7 days in advance. The analysis also demonstrates the existence of a long‐term trend in the accuracy of the forecasts. For example, Day‐3 forecasts of minimum temperature in recent years (average error ∼1.6 °C) are as skilful as Day‐1 forecasts of minimum temperature in the 1960s and 1970s, whilst Day‐4 forecasts of maximum temperature in recent years (average error ∼2.0 °C) are more skilful than Day‐1 forecasts of maximum temperature in the 1960s and 1970s. It is suggested that this trend may be largely attributed to: a combination of (1) enhancements in the description of the atmosphere's initial state provided by remote sensing and other observational technologies; (2) advances in broad‐scale numerical weather prediction (NWP); and (3) improvements in the forecast process that are supported by good organizational management, including developing and implementing new prediction techniques, and careful succession planning. Copyright © 2008 Royal Meteorological Society
Detailed 1H and 13C NMR structural assignment and relative stereochemistry determination for three closely related sesquiterpene lactones
Authors: Heleno Vladimir Constantino Gomes , de Oliveira Kleber Thiago , Lopes João Luis Callegari , Lopes Norberto Peporine , Ferreira Antonio Gilberto
Published: March 2008

A complete analysis of 1H and 13C NMR spectra of the trypanocidal sesquiterpene lactone eremantholide C and two of its analogues is described. These structurally similar sesquiterpene lactones were submitted to 1H NMR, 13C {1H} NMR, gCOSY, gHSQC, gHMBC, J‐resolved and DPFGSE‐NOE NMR techniques. The detailed analysis of those results, correlated to some computational calculations (molecular mechanics), led to the total and unequivocal assignment of all 1H and 13C NMR data. The determination of all 1H/1H coupling constants and all signal multiplicities, together with the elimination of previous ambiguities were also achieved. Copyright © 2008 John Wiley & Sons, Ltd.
A discontinuous enrichment method for three‐dimensional multiscale harmonic wave propagation problems in multi‐fluid and fluid–solid media
Authors: Massimi Paolo , Tezaur Radek , Farhat Charbel
Published: March 2008

An evanescent wave occurs when a propagating incident wave impinges on an interface between two fluid, solid, or fluid–solid media at a subcritical angle. Mathematical properties of such a wave make it difficult to capture with standard finite element discretization schemes. For this reason, the discontinuous enrichment method (DEM) developed in (Comput. Methods Appl. Mech. Eng. 2001; 190:6455–6479; Comput. Methods Appl. Mech. Eng. 2003; 192:1389–1419; Comput. Methods Appl. Mech. Eng. 2003; 192:3195–3210; Int. J. Numer. Meth. Engng 2004; 61:1938–1956; Wave Motion 2004; 39(4):307–317; Int. J. Numer. Meth. Engng 2006; 66:2086–2114; Int. J. Numer. Meth. Engng 2006; 66:796–815) is extended here to the solution of a class of three‐dimensional evanescent wave problems in the frequency domain. To this effect, new DEM elements for three‐dimensional elastodynamic problems are first proposed. Then, these and other DEM elements previously developed for the efficient solution of the Helmholtz problem are further enriched with free‐space solutions of model evanescent wave problems, in order to achieve high accuracy at practical mesh resolution for fluid–fluid and fluid–solid applications. The performance of the extended DEM elements is reported to be better than that of its basic Helmholtz and Navier counterparts and superior to that achieved by the classical high‐order polynomial finite element method. Copyright © 2008 John Wiley & Sons, Ltd.
Numerical simulation of nonclassical waves for immiscible three‐phase flow in heterogeneous porous media
Authors: Abreu Eduardo
Published: March 2008

In this paper we present accurate two‐dimensional numerical results, based on a new fractional time‐step method, for the numerical solution of a highly nonlinear system of partial differential equations modeling three‐phase immiscible water‐gasoil flow problems in heterogeneous petroleum reservoirs.

The new numerical procedure was used to extend theoretical results for one‐dimensional three‐phase flow available in the literature by providing numerical evidence of the existence of nonclassical transitional shock in heterogeneous twodimensional three‐phase flows. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Numerical procedures for the determination of the leading coefficient a (x)
Authors: Azari Hossein
Published: March 2008

The aim of this paper is to study the parabolic inverse problem of determination of the leading coefficient in the heat equation with an extra condition at the terminal. After introducing a new variable, we reformulate the problem as a nonclassical parabolic equation along with the initial and boundary conditions. The finite difference methods, backward Euler and Crank–Nicolson schemes are studied. The results of a numerical example are presented, which demonstrate the efficiency and rapid convergence of the methods. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Configurational forces in a micro‐cracked body
Authors: Boma Malika Bongué , Brocato Maurizio
Published: March 2008

A framework to model micro‐cracked bodies based on the theory of continua with microstructure is presented: assuming a crack embedded in each material element, a field is considered characterising size and orientation of the crack, in addition to the usual placement in the Euclidian space. To deal with crack evolutions, we call upon configurational forces which, in the present case, occur at the level of the microstructure. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The eigen‐structure of the Jacobian in multi‐class Lighthill‐Whitham‐Richards traffic flow models
Authors: Donat R. , Mulet P.
Published: March 2008

Characteristic‐based High Resolution Shock Capturing schemes for hyperbolic systems of conservation laws require, in their basic design structure, knowledge on the complete eigen‐decomposition of the Jacobian matrix of the system. For the Multi‐Class Lighthill‐Witham‐Richards (MCLWR) Traffic flow model considered in [4], there is no explicit formula for the eigenvalues of the Jacobian matrix, which can only be determined numerically. However, once they are determined, the eigen‐vectors are easily computed and straightforward formulas can be obtained by exploiting the specific structure of the Jacobian matrix in these models. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Multilevel regularization for image deblurring problems
Authors: Donatelli M.
Published: March 2008

We consider the de‐blurring problem of noisy and blurred signals/images in the case of space invariant point spread functions. The use of appropriate boundary conditions leads to linear systems with structured coefficient matrices related to space invariant operators like Toeplitz, circulants, trigonometric matrix algebras etc. We combine an algebraic multigrid (which is designed ad hoc for structured matrices) with the low‐pass projectors typical of the classical geometrical multigrid for elliptic partial differential equations. The smoother is any iterative regularizing method, while the projector is chosen in order to maintain the same algebraic structure at each recursion level and having a low‐pass filter property, which is very useful in order to reduce the noise effects. In this way, we obtain a better restored image with a flatter restoration error curve and also in less time than the auxiliary method used as smoother. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Numerical modelling of the hydrodynamic field coupled to the transport of chemical species through the finite‐element method
Authors: Anjos G. R. dos , Mangiavacchi N. , Pontes J. , Soares C. B. P.
Published: March 2008

We describe the main features of a numerical simulator currently under development for studying water physico‐chemical properties during the flooding of hydroelectric plants reservoirs. The work is sponsored by the brazilian Electric Energy National Agency ANEEL and conducted in a joint work of brazilian universities rearchers, with Furnas Centrais Elétricas S. A., the leading brazilian power utility company. An overview of the simulator requirements and of the involved partners is given. The software modules and engineering solutions are briefly discussed, including the finite element based transport module. Some results, future steps and partnerships are presented and discussed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Global properties of time‐delayed feedback control in electronic circuits
Authors: Höhne Klaus , Benner Hartmut
Published: March 2008

Global properties play an important role in real life applications of time‐delayed feedback control of chaos. The success of control is not only determined by the change of the local stability of some unstable periodic state embedded in the chaotic attractor, but also related to a basin of attraction large enough to capture the chaotic trajectory within a reasonable time. We report on electronic circuit experiments where the control performance is essentially affected by the type of bifurcations limiting the control regime and their respective global properties. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Adaptive linearized models for optimization of gas networks
Authors: Kolb Oliver , Lang Jens , Bales Pia
Published: March 2008

We are interested in simulation and optimization of gas networks. Usually, a gas network consists of various components like compressors and valves connected by pipes. The aim is to run the network cost efficiently whereas demands of consumers have to be satisfied. This results in a complex nonlinear mixed integer problem. We address this task with methods provided by discrete optimization. Therefore, the gas dynamics in all pipes and at compressors must be described by piecewise linear constraints. We introduce an adaptive approach for the linearization process to handle the complexity on the one hand and the aimed accuracy on the other and present numerical simulation and optimization results based on our model. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Finite volume element method for the incompressible miscible displacement problems in porous media
Authors: Kumar Sarvesh , Nataraj Neela , Pani Amiya K.
Published: March 2008

We present the finite volume element method (FVEM) for incompressible miscible displacement problems in porous media. Optimal error estimates in L∞(L2) are derived for velocity and concentration. Numerical experiments are also presented. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)