bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determining snow water equivalent by acoustic sounding
Authors: Kinar N. J. , Pomeroy J. W. 
Published: August 2007

AbstractThe possibility of determining snow water equivalent (SWE) by the use of an acoustic impulse was assessed at two field locations in Saskatchewan and British Columbia, Canada. These sites represent cold windswept prairie and temperate deep mountain snowcovers. A continuous frequency‐swept acoustic wave was sent into the snowpack and received. Signal processing was then subsequently used to estimate the depth and density of each snow layer by a recursive relationship involving frequency‐modulated continuous‐wave (FMCW) radar and seismological techniques. From this method, it is also shown that the tortuosity of snow can be estimated. Data collected by gravimetric sampling was used as comparison to the SWE values determined by the use of acoustic sounding. The results showed that for the Saskatchewan sites, the correlation between the measured and the modeled values of SWE was 0·86, whereas at the British Columbia sites, the correlation was 0·78. The difference in the correlations was interpreted as being due to additional acoustic measurement error at the British Columbia sites caused by higher liquid water contents and more layers in the snowpack. The measured and the modeled SWE for Saskatchewan snowpacks with high liquid water contents were found to be weakly associated with correlations of 0·30. The acoustically‐determined values of tortuosity were close to unity (α ≈ 1), which is in agreement with the values characteristic of snow as a porous substance. Further research is necessary to determine whether this technique can be applied to snow in other environmental conditions. Copyright © 2007 John Wiley & Sons, Ltd.
Field and laboratory estimates of pore size properties and hydraulic characteristics for subarctic organic soils
Authors: Carey Sean K. , Quinton William L. , Goeller Neil T. 
Published: August 2007

AbstractCharacterizing active and water‐conducting porosity in organic soils in both saturated and unsaturated zones is required for models of water and solute transport. There is a limitation, largely due to lack of data, on the hydraulic properties of unsaturated organic soils in permafrost regions, and in particular, the relationship between hydraulic conductivity and pressure head. Additionally, there is uncertainty as to what fraction of the matrix and what pores conduct water at different pressure heads, as closed and dead‐end pores are common features in organic soil. The objectives of this study were to determine the water‐conducting porosity of organic soils for different pore radii ranges using the method proposed by Bodhinayake et al. (2004) [Soil Sci. Soc. Am. J. 68:760–769] and compare these values to active pore size distributions from resin‐impregnated laboratory thin sections and pressure plate analysis. Field experiments and soil samples were completed in the Wolf Creek Research Basin, Yukon. Water infiltration rates were measured 16 times using a tension infiltrometer (TI) at 5 different pressure heads from − 150 to 0 mm. This data was combined with Gardiner's (1958) exponential unsaturated hydraulic conductivity function to provide water‐conducting porosity for different pore‐size ranges. Total water‐conducting porosity was 1·1 × 10−4, which accounted for only 0·01% of the total soil volume. Active pore areas obtained from 2‐D image analysis ranged from 0·45 to 0·60, declining with depth. Macropores accounted for approximately 65% of the water flux at saturation, yet all methods suggest macropores account for only a small fraction of the total porosity. Results among the methods are highly equivocal, and more research is required to reconcile field and laboratory methods of pore and hydraulic characteristics. However, this information is of significant value as organic soils in permafrost regions are poorly characterized in the literature. Copyright © 2007 John Wiley & Sons, Ltd.
Different membrane modifications revealed by atomic force/lateral force microscopy after doping of human pancreatic cells with Cd, Zn, or Pb
Authors: Girasole Marco , Cricenti Antonio , Generosi Renato , Longo Giovanni , Pompeo Giuliano , Cotesta Simona , Congiu‐Castellano Agostina 
Published: August 2007

AbstractThe interaction of the cytotoxic metals cadmium, zinc, and lead with pancreatic cells was studied by atomic force/lateral Force microscopy (AFM/LFM), an approach that provides both topographic (with nanometer scale lateral resolution) and chemical information on the membrane. Different morphological modifications of the overall cell shape and roughness took place as consequence of 100 μM metal‐dependent treatment. Furthermore, after exposure to Cd(Cl2) and Zn(Cl2), but not Pb(Cl2), the LFM images revealed several areas of the cell's surface showing lateral friction contrasts that have been interpreted as marker of different alterations of the cell physiology induced by the metal loading. Thus, the coupling of LFM detection to topographic AFM characterization allows to distinguish, through a nondestructive and surface characterising approach, between different metal‐induced cytotoxic effects on cells. In this framework, the role of the LFM as an important tool to discriminate between different alteration of a biological system has to be highlighted. Microsc. Res. Tech., 2007. © 2007 Wiley‐Liss, Inc.
Characterization and expression profile of the ovarian cytochrome P‐450 aromatase (cyp19A1) gene during thermolabile sex determination in pejerrey, Odontesthes bonariensis
Authors: Karube Makiko , Fernandino Juan Ignacio , Strobl‐Mazzulla Pablo , Strüssmann Carlos Augusto , Yoshizaki Goro , Somoza Gustavo Manuel , Patiño Reynaldo 
Published: August 2007

AbstractCytochrome P450 aromatase (cyp19) is an enzyme that catalyzes the conversion of androgens to estrogens and may play a role in temperature‐dependent sex determination (TSD) of reptiles, amphibians, and fishes. In this study, the ovarian P450 aromatase form (cyp19A1) of pejerrey Odontesthes bonariensis, a teleost with marked TSD, was cloned and its expression profile evaluated during gonadal differentiation at feminizing (17°C, 100% females), mixed‐sex producing (24 and 25°C, 73.3 and 26.7% females, respectively), and masculinizing (29°C, 0% females) temperatures. The deduced cyp19A1 amino acid sequence shared high identity (>77.8%) with that from other teleosts but had low identity (<61.8%) with brain forms (cyp19A2), including that of pejerrey itself. The tissue distribution analysis of cyp19A1 mRNA in adult fish revealed high expression in the ovary. Semi‐quantitative reverse transcription polymerase chain reaction analysis of the bodies of larvae revealed that cyp19A1 expression increased before the appearance of the first histological signs of ovarian differentiation at the feminizing temperature but remained low at the masculinizing temperature. The expression levels at mixed‐sex producing temperatures were bimodal rather than intermediate, showing low and high modal values similar to those at the feminizing and masculinizing temperatures, respectively. The population percentages of high and low expression levels at intermediate temperatures were proportional to the percentage of females and males, respectively, and high levels were first observed at about the time of sex differentiation of females. These results suggest that cyp19A1 is involved in the process of ovarian formation and possibly also in the TSD of pejerrey. J. Exp. Zool. 307A:625–636, 2007. © 2007 Wiley‐Liss, Inc.
Eye drop delivery of nano‐polymeric micelle formulated genes with cornea‐specific promoters
Authors: Tong Yaw‐Chong , Chang Shwu‐Fen , Liu Chia‐Yang , Kao Winston W.‐Y. , Huang Chong Heng , Liaw Jiahorng 
Published: August 2007

AbstractBackgroundThis study evaluates the eye drop delivery of genes with cornea‐specific promoters, i.e., keratin 12 (K12) and keratocan (Kera3.2) promoters, by non‐ionic poly(ethylene oxide)‐poly(propylene oxide)‐poly(ethylene oxide) (PEO‐PPO‐PEO) polymeric micelles (PM) to mouse and rabbit eyes, and investigates the underlying mechanisms.MethodsThree PM‐formulated plasmids (pCMV‐Lac Z, pK12‐Lac Z and pKera3.2‐Lac Z) containing the Lac Z gene for β‐galactosidase (β‐Gal) whose expression was driven by the promoter of either the cytomegalovirus early gene, the keratin 12 gene or the keratocan gene, were characterized by critical micelle concentration (CMC), dynamic light scattering (DLS), and atomic force microscopy (AFM). Transgene expression in ocular tissue after gene delivery was analyzed by 5‐bromo‐4‐chloro‐3‐indolyl‐β‐D‐galactoside (X‐Gal) color staining, 1,2‐dioxetane β‐Gal enzymatic activity measurement, and real‐time polymerase chain reaction (PCR) analysis. The delivery mechanisms of plasmid‐PM on mouse and rabbit corneas were evaluated by EDTA and RGD (arginine‐glycine‐aspartic acid) peptide.ResultsThe sizes of the three plasmid‐PM complexes were around 150–200 nm with unimodal distribution. Enhanced stability was found for three plasmid‐PM formulations after DNase I treatment. After six doses of eye drop delivery of pK12‐Lac Z‐PM three times a day, β‐Gal activity was significantly increased in both mouse and rabbit corneas. Stroma‐specific Lac Z expression was only found in pKera3.2‐Lac Z‐PM‐treated animals with pretreatment by 5 mM EDTA, an opener of junctions. Lac Z gene expression in both pK12‐Lac Z‐PM and pKera3.2‐Lac Z‐PM delivery groups was decreased by RGD peptide pretreatment.ConclusionsCornea epithelium‐ and stroma‐specific gene expression could be achieved using cornea‐specific promoters of keratin 12 and keratocan genes, and the gene was delivered with PM formulation through non‐invasive, eye drop in mice and rabbits. The transfection mechanism of plasmid‐PM may involve endocytosis and particle size dependent paracellular transport. Copyright © 2007 John Wiley & Sons, Ltd.
Investigating the presence of pesticide transformation products in water by using liquid chromatography‐mass spectrometry with different mass analyzers
Authors: Hernández Félix , Ibáñez María , Pozo Óscar J. , Sancho Juan V. 
Published: August 2007

AbstractMany pesticide transformation products (TPs) can reach environmental waters as a consequence of their normally having a higher polarity than their parent pesticides. This makes the development of analytical methodology for reliable identification and subsequent quantification at the sub‐microgram per liter levels necessary, as required under current legislation. In this paper we report the photodegradation of several pesticides frequently detected in environmental waters from the Spanish Mediterranean region using the high‐resolution and exact‐mass capabilities of hybrid quadrupole time‐of‐flight mass spectrometry (QTOF MS) hyphenated to liquid chromatography (LC). Once the main photodegradation/hydrolysis products formed in aqueous media were identified, analytical methodology for their simultaneous quantification and reliable identification in real water samples was developed using on‐line solid‐phase extraction (SPE)‐LC‐tandem MS with a triple‐quadrupole (QqQ) analyzer. The methodology was validated in both ground and surface water samples spiked at the limit of quantification (LOQ) and 10 × LOQ levels, i.e. 50 and 500 ng/l, obtaining satisfactory recoveries and precision for all compounds. Subsequent analysis of ground and surface water samples resulted in the detection of a number of TPs higher than parent pesticides. Additionally, several soil‐interstitial water samples collected from the unsaturated zone were analyzed to explore the degradation/transformation of some pesticides in the field using experimental plots equipped with lisimeters. Several TPs were found in these samples, with most of them having also been detected in ground and surface water from the same area. This paper illustrates the extraordinary potential of LC‐MS(/MS) with QTOF and QqQ analyzers for qualitative/structural and quantitative analysis, respectively, offering analytical chemists one of the most powerful tools available at present to investigate the presence of pesticide TPs in water. Copyright © 2007 John Wiley & Sons, Ltd.
Assessments of Mediterranean precipitation changes for the 21st century using statistical downscaling techniques
Authors: Hertig E. , Jacobeit J. 
Published: August 2007

AbstractStatistical downscaling techniques are used to assess Mediterranean precipitation changes for the period 1990–2100 under increased greenhouse warming conditions from climate model output of large‐scale predictor changes. Analyses are carried out on a monthly basis for the main rainy season from October to May. Results of two statistical techniques, multiple regression analysis, and canonical correlation analysis, are compared. Furthermore, differences which arise from the use of different combinations of the predictor variables, such as geopotential heights, humidity, and sea surface temperatures are discussed. Predictor output from seven different AOGCM runs (two ECHAM4/OPYC3 runs, four ECHO‐G runs including a three‐member ensemble, and one HadCM3 run) is used to assess Mediterranean precipitation changes in the 21st century. Five of the AOGCM runs were forced with B2 scenario assumptions according to the special report on emission scenarios (SRES), one with SRES‐A2 scenario assumptions, and one with the former IS92a scenario. Using 1000 hPa‐/500 hPa‐geopotential heights and 1000 hPa‐specific humidity as large‐scale predictors, a shorter but wetter wet season is evident for the western and northern Mediterranean regions including precipitation increases in winter and decreases in the transitional seasons for the period 2071–2100 compared to 1990–2019. The eastern and southern parts of the Mediterranean area exhibit mainly negative precipitation changes from October to May for an increased greenhouse gas forcing. Copyright © 2007 Royal Meteorological Society
Targeting gold at the end of the rainbow: Surgical gamma probes in the 21st century
Authors: Moffat Frederick L. 
Published: August 2007

AbstractSurgical gamma detection probes (GDPs) have become important in the surgical management of neoplastic disease in the past 20 years. Their history and radiophysics are discussed, with consideration of the overarching issue of tumor‐to‐background ratio (TBR). GDPs are currently most commonly used in sentinel node applications in a variety of tumors. Whether their role in clinical surgical practice can be extended to other applications will depend on the development of radiolabeled tumor marking agents which have much improved TBR, and parallel developments in oncology research which may overtake this technology. J. Surg. Oncol. 2007;96:286–289. © 2007 Wiley‐Liss, Inc.
PET probe‐guided surgery
Authors: Gulec Seza A. 
Published: August 2007

AbstractIntraoperative localization of PET‐positive recurrent/metastatic lesions can be facilitated using a hand‐held PET probe. PET probe is a high‐energy gamma probe designed to process the 511 keV photons of PET tracers. Intraoperative gamma probe performance is a function of radiopharmaceutical uptake, clearance kinetics, and probe engineering, all determining the target to background ratio (TBR) and detection threshold. A minimum TBR of 1.5:1 is needed in the operative field for the operating surgeon to be comfortable the differences between tumor tissue and normal adjacent tissue are real. Due to high‐energy photon fluxes, achieving a satisfactory TBR intraoperatively is challenging and requires development of a clinically feasible PET‐probe guided surgery protocol. J. Surg. Oncol. 2007;96:353–357. © 2007 Wiley‐Liss, Inc.
The sentinel concept in patients with cervical cancer
Authors: Schneider Achim 
Published: August 2007

AbstractThe sentinel concept for patients with early cervical cancer has a high potential for decreasing morbidity and for increasing oncologic safety. The detection rate with technetium‐labeling or a combination with blue dye varies between 84% and 92%. Sensitivity and negative predictive value depend on tumor size: the smaller the tumor, the higher the validity of the technique. Detection of circulating tumor cells in the sentinel node using HPVmRNA as marker may have a good prognostic value. Currently the sentinel concept should only be used in clinical studies before its validity has been proved. J. Surg. Oncol. 2007;96:337–341. © 2007 Wiley‐Liss, Inc.
Influence of Low‐Molecular‐Weight Diamines in the Direct Imidation of Poly(propylene)‐Grafted Maleic Anhydride by Melt Reaction
Authors: Vazquez‐Rodriguez Sofia , Sánchez‐Valdes Saúl , Rodríguez‐González Francisco J. , González‐Cantú Maria C. 
Published: August 2007

AbstractAminated poly(propylene) was prepared by reacting aliphatic primary diamines with maleic‐anhydride‐functionalized poly(propylene) by in situ melt reaction. Around 60–70% of the initial acid groups had reacted to form amide and imide groups as confirmed by the almost complete disappearance of the maleic anhydride peak in FT‐IR spectra. The molecular weight of the diamines had an influence on changes in molecular structure of the PP‐g‐NH2 as a result of secondary reactions such as chain extension and cross‐linking. PP‐g‐NH2 and polycarbonate were pressed into two‐layer films and their adhesion strength was measured. The results showed that PP‐g‐NH2 was a very effective adhesion promoter.magnified image
Mechanical and Morphological Studies of Poly(propylene)‐Filled Eggshell Composites
Authors: Toro Patricio , Quijada Raúl , Arias José Luis , Yazdani‐Pedram Mehrdad 
Published: August 2007

AbstractPoly(propylene) (PP) composites were prepared by using eggshell (ES) as filler and their mechanical properties were compared with those using talc (TA) and calcium carbonate (CC) of different grain sizes (X50). A decrease in impact strength and deformation at break with increase in filler content was observed. The PP composite with ES (X50 = 8.4 µm) was stiffer than those with CC (X50 = 0.7 µm). The hybrid composite PP‐ES‐TA showed a similar stiffness as the PP‐TA composites due to the similar morphology of TA (X50 = 0.5 µm) and ES, when TA was replaced up to 75 wt.‐% by ES. SEM study revealed evidence of improved interfacial bonding between PP and ES in theirs composites.magnified image
Customer retention when the customer's future usage is uncertain
Authors: White Tiffany Barnett , Lemon Katherine N. , Hogan John E. 
Published: August 2007

AbstractConsumers are often uncertain about how much they will use a service in the future (e.g., health clubs, credit cards, cell phones), yet the effects of this uncertainty on customer retention have not been studied. This research investigates factors influencing consumers' decisions about whether to retain noncontractual services for which anticipated future usage levels are uncertain. The studies show that Future Usage Uncertainty (FUU) generally reduces the likelihood that a customer will continue in a service relationship. However, when consumers consider the flexibility they have to delay the keep/drop decision (i.e., drop flexibility), or the anticipated regret associated with making the wrong decision, the effects of FUU are essentially eliminated, and consumers are more likely to continue in the relationship. © 2007 Wiley Periodicals, Inc.
Gratitude, delight, or guilt: The role of consumers' emotions in predicting postconsumption behaviors
Authors: Soscia Isabella 
Published: August 2007

AbstractThis study investigates the relationships among appraisals (goal congruence/incongruence and agency), consumption emotions (gratitude, happiness, guilt, anger, pride, and sadness), and post‐consumption behaviors (positive and negative word of mouth, repurchase intention, and complaint behavior). The findings demonstrate that these emotions predict different specific types of post‐consumption behaviors and that they are elicited by appraisals specified in the psychology literature. In particular, gratitude but not happiness, predicts repurchase intention and positive word of mouth. By contrast, guilt inhibits complaint behaviors and negative word of mouth. The implications of these findings for marketing practice are discussed. © 2007 Wiley Periodicals, Inc.
Stereospecific and Stereoselective Polymerization of 4‐Methyl‐1‐hexene by Enantiomeric Binaphthyl‐Bridged Salen Dichlorozirconium (IV) Complexes
Authors: Strianese Maria , Lamberti Marina , Mazzeo Mina , Pellecchia Claudio 
Published: August 2007

AbstractTwo enantiomers of a chiral binaphthyl‐bridged salen dichlorozirconium (IV) complex (namely R‐Λ‐1 and S‐Δ‐1) were synthesized and tested as pre‐catalysts for 4‐methyl‐1‐hexene (4MH) polymerization. Their behavior was compared with that of the same complex in its racemic form. Isotactic poly(4‐methyl‐1‐hexene) was produced in both cases, but the polymerization of racemic 4MH promoted by the optically active catalysts preferentially consumed one antipode, showing some stereoselectivity for the process.magnified image
Modelling the urban climate using a local governmental geo‐database
Authors: Lindberg Fredrik 
Published: August 2007

AbstractIn this study, local government digital spatial data are used to describe urban geometry and analyse spatial variations of the urban climate within the central areas of Göteborg, Sweden. A high‐resolution raster digital elevation model (1 m pixel resolution) consisting of building structures and ground heights is derived from a local government geo‐database, as well as land use patterns and artificial heat sources. Parameters such as the sky view factor (SVF) and daily averages of solar radiation are calculated. Results obtained from the model are compared with intra‐urban air temperature variations which are derived from mobile measurements, as well as surface temperature variations derived from thermal infrared images. Results show that high‐resolution digital elevation models in raster format are very useful sources of data for the investigation of intra‐urban temperature variations. Results also show that the areal mean of SVF correlates with intra‐urban air temperature variations to a higher degree than SVF that is taken from a point source location. The correlation between the modelled SVF and surface temperature is high during both spring and winter. Adding information about daily averages of global radiation for the spring measurement causes the correlation between SVF and surface temperature variations to increase. Copyright © 2007 Royal Meteorological Society