bluuebunny/crossref_metadata_2025_split huggingface dataset:
Seasonal variations in the spatial‐temporal dependence of total column ozone
Authors: Stein Michael L. 
Published: September 2006

AbstractThe Total Ozone Mapping Spectrometer (TOMS) is a satellite‐based instrument that measures total column ozone on a daily basis over a fairly dense spatial grid with near global coverage. Statistical models for the spatial‐temporal variations in total column ozone provide insights into ozone dynamics, are valuable for obtaining inferences on long‐term trends in ozone levels, and can be used to predict ozone levels at unobserved points in space‐time. However, developing such a model is complicated by the seasonally varying nature of the space‐time dependence and the partial confounding of spatial and temporal variation caused by the sun‐synchronous orbit of the satellite. This work considers methods for describing, modeling and estimating the seasonal patterns in the dependence structure for measurements at a single latitude. Applying one of these models to the synoptic prediction of total column ozone at a latitude shows that there is at least the potential for substantially improved predictions by exploiting the high spatial density of observations TOMS provides. Copyright © 2006 John Wiley & Sons, Ltd.
Combining sampling and model weights in agriculture small area estimation
Authors: Militino A. F. , Ugarte M. D. , Goicoa T. 
Published: September 2006

AbstractThis paper is focussed on agriculture small area models for predicting minor crops. In the application considered here, the study domain is often poor in the crop of interest leading to irregular and sparsely distributed plots, usually smaller than the segments used in the sampling design. Hence, the variability among the sampled units becomes large in those areas with a high number of segments. To date, models including weights to account for heteroscedasticity, as well as models considering sampling weights to achieve design‐consistency have been proposed to derive estimators of small area means or totals. In this work, we discuss extensions of these models and the convenience of using both types of weighting. The models performance is illustrated for predicting the total area occupied by olive trees in a region of Navarra, Spain. Copyright © 2006 John Wiley & Sons, Ltd.
Similar chromosomal changes in cisplatin and oxaliplatin‐resistant sublines of the H69 SCLC cell line are not associated with platinum resistance
Authors: Stordal Britta , Peters Greg , Davey Ross 
Published: September 2006

AbstractSmall cell lung cancer (SCLC) initially responds well to DNA damaging drugs such as cisplatin, however this is transitory as resistance normally develops. To investigate whether changes in chromosomal copy number caused by platinum drug treatment contributes to platinum resistance, we have analyzed H69 SCLC cells and two low‐level platinum‐resistant sublines, H69CIS200 and H69OX400, derived by cisplatin and oxaliplatin treatment, respectively. Affymetrix 10K SNP array showed that cisplatin and oxaliplatin have independently caused similar changes including loss of segments 6q21‐qter and 13pter‐13q.14.11 and duplication of chromosome 21. Interestingly, despite using equally cytotoxic doses of drug in the development of the cell lines, oxaliplatin caused three times more chromosomal changes than cisplatin. The resistant cell lines lose their resistant phenotype after 3 months of drug‐free culture. The revertant cell lines, denoted H69CIS200‐S and H69OX400‐S, were also analyzed by Affymetrix array to determine if chromosomal changes associated with resistance remain after the resistant phenotype is lost. In the H69OX400‐S many of the changes observed in the resistant cells were absent suggesting that they contributed to the resistant phenotype including: loss of 1q23.3‐qter, 10q11.23, and 19q13.12‐q13.2 and duplication of segments 6p21.2‐p12.3, 16q12.1‐16q13, 16q21‐q23.1, and 19q12. However, out of the similar changes induced by cisplatin and oxaliplatin, both the loss of 6q21‐qter and gain of 21 were still present in the H69CIS200‐S and H69OX400‐S cells. This suggests that cisplatin and oxaliplatin induced similar changes due to inherent vulnerabilities in the H69 cells rather than changes associated with platinum resistance. © 2006 Wiley‐Liss, Inc.
Riparian influence on hyporheic‐zone formation downstream of a small dam in the Blackland Prairie region of Texas
Authors: Duke Jacquelyn R. , White Joseph D. , Allen Peter M. , Muttiah Ranjan S. 
Published: September 2006

AbstractSmall‐order streams have highly variable flows that can result in large temporal and spatial variation of the hyporheic zone. Dam construction along these intermittent headwater streams alters downstream flow and influences the hydrologic balance between stream water and the adjacent riparian zone. A 3‐year site study was conducted along an impounded second‐order stream to determine the water balance between stream, unsaturated zone, groundwater and riparian vegetation. The presence of the upstream impoundment provided near‐perennial water flow in the stream channel. The observed woody plant transpiration accounted for 71% of average annual water loss in the site. The overall contribution of stream water via the hyporheic zone to site water balance was 73 cm, or 44% of total inputs. This exceeded both rainfall and upland subsurface contribution to the site. A highly dynamic hyporheic zone was indicated by high water use from woody plants that fluctuated seasonally with stream water levels. We found leaf area development in the canopy layer to be closely coupled with stream and groundwater fluctuations, indicating its usefulness as a potential indicator of site water balance for small dam systems. The net result of upstream impoundment increased riparian vegetation productivity by influencing movement of stream water to storage in the groundwater system. Copyright © 2006 John Wiley & Sons, Ltd.
Lumped hysteretic model for subsurface stormflow developed using downward approach
Authors: Ewen John , Birkinshaw Stephen J. 
Published: September 2006

AbstractThe terms ‘downward’ and ‘upward’ (synonymous with ‘top‐down’ and ‘bottom‐up’ respectively) are sometimes used when describing methods for developing hydrological models. A downward approach is used here to develop a lumped catchment‐scale model for subsurface stormflow at the 0·94 km2 Slapton Wood catchment. During the development, as few assumptions as possible are made about the behaviour of subsurface stormflow at the catchment scale, and no assumptions are made about its behaviour at smaller scales. (In an upward approach, in contrast, the modelling would be based on assumptions about, and data for, the behaviour at smaller scales, such as the hillslope, plot, and point scales.) The model has a single store with a relatively simple relationship between discharge and storage, based on equations describing hysteretic patterns seen in a graph of discharge against storage. Double‐peaked hydrographs have been observed at the catchment outlet. Rainfall on the channel and infiltration‐excess and saturation‐excess runoff give a rapid response, and shallow subsurface stormflow gives a delayed response. Hydrographs are successfully simulated for the large delayed responses observed in 1971–1980 and 1989–1991, then a lumped model for the rapid response is coupled to the lumped hysteretic model and some double‐peaked hydrographs simulated. A physical interpretation is developed for the lumped hysteretic model, making use of information on patterns of perched saturation observed in 1982 on a hillslope at the Slapton Wood catchment. Downward and upward approaches are complementary, and the most robust way to develop and improve lumped catchment models is to iterate between downward and upward steps. Possible next steps are described. Copyright © 2006 John Wiley & Sons, Ltd.
D and 18O enrichment measurements in biological fluids in a continuous‐flow elemental analyser with an isotope‐ratio mass spectrometer using two configurations
Authors: Ripoche N. , Ferchaud‐Roucher V. , Krempf M. , Ritz P. 
Published: September 2006

AbstractIn doubly labelled water studies, biological sample enrichments are mainly measured using off‐line techniques (equilibration followed by dual‐inlet introduction) or high‐temperature elemental analysis (HT‐EA), coupled with an isotope‐ratio mass spectrometer (IRMS). Here another continuous‐flow method, (CF‐EA/IRMS), initially dedicated to water, is tested for plasma and urine analyses.The elemental analyser configuration is adapted for each stable isotope: chromium tube for deuterium reduction and glassy carbon reactor for 18O pyrolysis. Before on‐line conversion of water into gas, each matrix is submitted to a short and easy treatment, which is the same for the analysis of the two isotopes. Plasma is passed through centrifugal filters. Urine is cleaned with black carbon and filtered (0.45 µm diameter).Tested between 150 and 300 ppm in these fluids, the D/H ratio response is linear with good repeatability (SD < 0.2 ppm) and reproducibility (SD < 0.5 ppm). For 18O/16O ratios (from 2000 to 2200 ppm), the same repeatability is obtained with a between‐day precision lower than 1.4 ppm. The accuracy on biological samples is validated by comparison to classical dual‐inlet methods: 18O analyses give more accurate results. The data show that enriched physiological fluids can be successfully analysed in CF‐EA/IRMS. Copyright © 2006 John Wiley & Sons, Ltd.
The influence of atmospheric circulation at different spatial scales on winter drought variability through a semi‐arid climatic gradient in Northeast Spain
Authors: Vicente‐Serrano Sergio M. , López‐Moreno Juan I. 
Published: September 2006

AbstractThis paper analyses the spatial and temporal variability of winter droughts in a semi‐arid geographic gradient in Northeast Spain, from the Pyrenees in the north to the Mediterranean coastland in the south. Droughts that occurred between 1952 and 1999 were analysed by means of the Standardised Precipitation Index (SPI). The influence of the weather‐type frequency and of the general North Atlantic atmospheric circulation patterns was analysed. The results indicate that winter droughts show an important spatial variability in the study area, differentiating three well‐defined patterns. These correspond to the Pyrenees, the centre of the Ebro Valley, and the Mediterranean coastland. General negative trends in winter SPI have been found, which are indicative of the increase in winter drought conditions in the study area. Nevertheless, important spatial differences have also been recorded. Dominant north–south gradients in the influence of weather types are shown. Moreover, the negative trends in winter‐SPI values agree with the negative trend in the frequency of the weather types prone to cause precipitation, such as the C, SW and W weather types and the increase in the frequency of A weather types. Nevertheless, in the Mediterranean coastland, the positive trend in SPI values agrees with the increase in the frequency of weather types of the east (E, SE), which are prone to cause precipitation in this area. Interannual variations in the frequency of the different weather types have been highly determined by different general atmospheric circulation patterns, mainly the North Atlantic Oscillation (NAO). Nevertheless, the correlation between the time series of weather‐type frequency and the winter SPI is higher than that found between the SPI and the NAO. Thus, although the interannual NAO variability explains a high percentage of the interannual differences in the frequency of different weather types, it is not sufficient to explain the spatial and temporal variability of droughts, which respond better to atmospheric variability at more detailed (synoptic) spatial scales. Copyright © 2006 Royal Meteorological Society.
The Western Mediterranean Oscillation and rainfall in the Iberian Peninsula
Authors: Martin‐Vide Javier , Lopez‐Bustins Joan‐Albert 
Published: September 2006

AbstractSeasonal precipitation variability in the east of the Iberian Peninsula is weakly linked to the North Atlantic Oscillation (NAO) during autumn and winter. For the purpose of improving the study of its performance, low‐frequency variability patterns specific to the Mediterranean basin have been searched for. In this way, the Western Mediterranean Oscillation (WeMO) has been defined by means of the dipole composed, in its positive phase, by the anticyclone over the Azores and the depression over Liguria, and its index (WeMOi), as a result of the difference of the standardised values in surface atmospheric pressure in San Fernando (Spain) and Padua (Italy). This new index allows the detection of the variability relevant to the cyclogenesis next to the western Mediterranean basin, which determines in a predominant way the types of rainfall in the Gulf of Valencia. In this area, the WeMO is significantly better than the NAO to explain the monthly pluviometric anomalies during these seasons. Also, a daily resolution of the WeMOi can provide a useful tool to forecast torrential rainfall events in the north‐western zones of the Mediterranean (eastern part of the Iberian Peninsula and the south of France), and such significantly daily rainfall frequencies for different thresholds. Copyright © 2006 Royal Meteorological Society.
European cyclone track analysis based on ECMWF ERA‐40 data sets
Authors: Bartholy Judit , Pongrácz Rita , Pattantyús‐ábrahám Margit 
Published: September 2006

AbstractChanges in large‐scale circulation patterns over the North‐Atlantic‐European region are presented and analyzed for the 20th century. First, changes in decadal frequency of Hess‐Brezowsky macrocirculation patterns (MCP) are evaluated for the period between 1881 and 2000. Frequency of several MCP types increased or decreased considerably during these 120 years, which may be explained by large‐scale changes in circulation characteristics, e.g. by changes in cyclone activity in the different regions. Therefore, cyclone center identification and cyclone tracks and intensity analysis have been accomplished on the basis of the European Centre for Medium‐range Weather Forecast (ECMWF) reanalysis data sets (ERA‐40) on a 2.5° horizontal resolution grid for the period between 1957 and 2002. Results suggest that both the number of midlatitude cyclones and the cyclone activity increased considerably in the North‐Atlantic‐European region, especially in the northwestern part of the domain. Copyright © 2006 Royal Meteorological Society.
Spatial differentiation of air temperature in Poland using circulation types and GIS
Authors: Ustrnul Zbigniew 
Published: September 2006

AbstractThis paper is devoted to the synoptic–climatic analysis with the application of circulation types and Geographic Information Systems (GIS). Construction of daily climatic air temperature maps for the Polish territory was the main aim of the work. Analysis was based on the mean daily temperature data from all synoptic and some climatological stations (73 stations totally) for the 50‐year period of 1951–2000. The synoptic–climatic analysis was done using a well known circulation calendar developed by the German Meteorological Service ‘Grosswetterlagen’. Residual kriging was chosen for the map constructions. Several geographic parameters, including elevation, latitude, longitude, and distance to the Baltic coast, were used as predictor variables for air temperature. However, the particular circulation type was the crucial predictor. Maps were created for all months for the Grosswetterlagen circulation types, which occurred more than 30 times during 1951–2000. Special attention was paid to the extreme thermal months of January and July. Maps constructed in the way described confirmed that application of circulation types was quite a good tool for improving accuracy of thermal daily maps. Accuracy was much higher for most of the maps constructed for particular circulation types than for the maps created without application of circulation types. There was only one exception: non‐advective anticyclonic types during winter time. Then, relatively large variability of the temperature can be observed in the concave landforms and the constructed maps have only approximate meaning. Copyright © 2006 Royal Meteorological Society.
Variability in the characteristics of cut‐off low pressure systems over subtropical southern Africa
Authors: Singleton A. T. , Reason C. J. C. 
Published: September 2006

AbstractVariability in the characteristics of cut‐off low pressure systems over subtropical southern Africa is examined for the 1973–2002 period. These characteristics include their seasonality, frequency, duration, location and size. It is found that on average 11 cut‐off lows occur over southern Africa south of 20°S per year and are most common in the March‐May season. Potential relationships between the number of cut‐off lows over southern Africa with the El Niño Southern Oscillation (ENSO), the Pacific South America pattern, the wave number 3 pattern and the semi‐annual oscillation (SAO) are discussed. La Niña years appear to be associated with above average annual frequencies of cut‐off lows but the reverse is generally not true for El Niño years. There was a shift in the preferred season for cut‐off lows from March–May to June–August in the 1980s, which coincided with a weakening of the SAO and a shift in zonal wave number 3. This period also showed a change in the preferred location of these systems from southwestern subtropical southern Africa to the northeast of the region. The results suggest that there may be a relationship between cut‐off lows over subtropical southern Africa, the wave number 3 pattern in the Southern Hemisphere and the SAO. Copyright © 2006 Royal Meteorological Society.
Determination of some biochemical properties of polyphenol oxidase from Emir grape (Vitis vinifera L. cv. Emir)
Authors: Ünal M Ümit , Şener Aysun 
Published: September 2006

AbstractPolyphenol oxidase (PPO) was extracted from Emir grapes grown in Turkey and its characteristics in terms of pH and temperature optima, thermal inactivation, kinetic parameters and potency of some PPO inhibitors were studied. The optimum pH and temperature for grape PPO were found to be 4.2 and 25 °C respectively using catechol as substrate. Km and Vmax values were found to be 25.1 ± 2.72 mmol L−1 and 0.925 ± 0.04 OD410 min−1 respectively. Of the inhibitors tested, the most potent was sodium metabisulfite, followed by ascorbic acid. The thermal inactivation curve was biphasic. Activation energy (Ea) and Z values were calculated as 251.4 kJ mol−1 (r2 = 0.996) and 8.92 °C (r2 = 0.993) respectively. Copyright © 2006 Society of Chemical Industry
Accumulation of β‐catenin protein, mutations in exon‐3 of the β‐catenin gene and a loss of heterozygosity of 5q22 in solid pseudopapillary tumor of the pancreas
Authors: Min Kim Seong , Sun Chuan Dong , Park Ki Chung , Kim Ho Guen , Lee Woo Jung , Choi Seung Hoon 
Published: September 2006

AbstractBackgroundSolid pseudopapillary tumors (SPT) of the pancreas are neoplasms with a low malignant potential. The molecular events contributing to the pathogenesis of SPTs are still unknown.ObjectivesThis study was intended to help better understand the early steps of human SPT development.MethodsWe microdissected 20 SPTs and normal pancreatic tissue. In addition, we examined the DNA from each SPT for mutations in exon‐3 of β‐catenin and loss of heterozygosity (LOH) on 9 chromosome arms using 10 microsatellite markers. Immunohistochemical staining for β‐catenin was performed.ResultsActivating mutations between codons 32 and 37 of β‐catenin exon‐3 were present in 16 cases (80%). Allelic loss on chromosome 5q22.1 was present in 10 cases (55.5%), while no allelic loss was found on chromosomes 1p, 6q, 9p, 9q, 11p, 11q, 17p, or 22q. Nuclear accumulation of β‐catenin was found in 20 cases (100%).ConclusionMutations in exon‐3 of the β‐catenin gene, nuclear accumulation of β‐catenin, and LOH on chromosome 5q22.1 in SPT tissue suggest that these mutations are involved in SPT tumorigenesis. J. Surg. Oncol. 2006;94:418–425. © 2006 Wiley‐Liss, Inc.
High expressions of CD105 and VEGF in early oral cancer predict potential cervical metastasis
Authors: Chien Chih‐Yen , Su Chih‐Ying , Hwang Chung‐Feng , Chuang Hui‐Ching , Chen Ching‐Mei , Huang Chao‐Cheng 
Published: September 2006

AbstractBackground and ObjectivesAlthough elective neck dissection has become a popular treatment modality for early oral cancer among most head and neck surgeons, a large portion of patients revealed pathological N0 postoperatively. Our study is aimed to evaluate the expressions of the angiogenic factors, vascular endothelial growth factor (VEGF), and CD105 (endoglin) on the prediction of neck metastasis for clinical N0 patients in early oral cancer.Patients and MethodsBetween July 1996 and July 2005, the preoperative biopsy specimens among 176 patients who underwent surgical treatment for early oral cancer were retrieved for the immunohistochemical study for VEGF and CD105.ResultsHigh expressions of CD105 and VEGF significantly correlated with positive nodal metastasis, respectively (P < 0.001). The expression of CD105 also significantly correlated with that of VEGF (P < 0.001). Furthermore, the sensitivity and specificity for prediction of cervical metastasis by high expressions of CD105 versus VEGF were 81.8% and 97.7% versus 93.2% and 72%, respectively. Low expression of CD105 and VEGF also significantly correlated with higher survival rate, respectively (P < 0.001).ConclusionsBesides the image studies, the expressions of both CD105 and VEGF could be useful to guide the elective treatment for clinical N0 neck in early oral cancer. J. Surg. Oncol. 2006;94:413–417. © 2006 Wiley‐Liss, Inc.
High operative risk of cool‐tip radiofrequency ablation for unresectable pancreatic head cancer
Authors: Wu Yulian , Tang Zhe , Fang Heqing , Gao Shunliang , Chen Jian , Wang Yong , Yan Haichao 
Published: September 2006

AbstractBackground and ObjectivesTo report and discuss the effect, complications and mortality of cool‐tip radiofrequency ablation (RFA) for unresectable pancreatic cancer.MethodsDuring October 2003 to July 2004, sixteen patients with unresectable pancreatic cancer were treated by open cool‐tip RFA. One‐half of the 16 patients had tumors located in the pancreatic head. A 5‐mm minimum safe distance between RFA site and major peripancreatic vessels was kept to avoid injury to the vessels.ResultsSix of twelve patients with back pain got pain relief postoperatively. Pancreatic fistula occurred in three patients (18.8%) and healed smoothly in 7–10 days with routine abdominal drainage. The mortality was 25% (4/16). In the four death cases, tumors were all located in the pancreatic head; three patients with tumor close to portal vein died suddenly of massive gastrointestinal hemorrhage on the 4th, 30th, 40th postoperative day respectively and a 79‐year‐old patient died of acute renal failure on the 2nd postoperative day.ConclusionsStandard use of cool‐tip RFA was dangerous for pancreatic head cancer close to portal vein, in which a 5‐mm minimum safe distance between RFA site and major peripancreatic vessels might not be enough to avoid injury to the vessels. J. Surg. Oncol. 2006;94:392–395. © 2006 Wiley‐Liss, Inc.