bluuebunny/crossref_metadata_2025 huggingface dataset:
An integrated framework of lake‐stream connectivity for a semi‐arid, subarctic environment
Authors: Woo Ming‐ko , Mielko Corrinne
Published: August 2007

Lake‐stream networks dominate the semi‐arid, subarctic Precambrian shield. Such a network consists of a number of lake basin elements linked to each other by surface channels. To investigate the processes causing seasonal severance of flow connection in the lake‐stream system, a chain of lakes in northern Canada was studied in 2004. Water balance shows that rapid and substantial runoff from the local basin slopes during the snowmelt period led to a rise of lake levels above their outlet elevations to generate outflow. Continued summer evaporation caused draw down of lake storage below the outflow thresholds, represented by the lake outlet elevations. Outflow ceased and the lakes became disconnected. Summer rainfall in a semi‐arid environment was insufficient to overcome storage deficit to re‐establish flow connectivity among all lakes. For the drainage system as a whole, streamflow interruption or continuity depends on the linkage of its lake‐stream sub‐units. The principle of fill and spill governs runoff generation and flow connection between the lake elements. This principle is applied to a conceptual model of flow along a chain of lakes, taking account of (1) antecedent storage in individual lakes, (2) their storage change calculated through water balance and (3) the thresholds to be exceeded for outflows to occur. Copyright © 2007 John Wiley & Sons, Ltd.
A simple heat‐conduction method for simulating the frost‐table depth in hydrological models
Authors: Hayashi Masaki , Goeller Neil , Quinton William L. , Wright Nicole
Published: August 2007

Hillslope runoff in permafrost regions covered by organic soil is strongly influenced by subsurface flow in the active layer, as well as surface flow where the active layer is very shallow. Flow rates in the organic‐rich active layer are strongly dependent on the depth to the thawing front (i.e. frost table) and the corresponding soil hydraulic conductivity at that depth. Therefore, hydrological models for permafrost terrains need to simulate the thawing of the active layer accurately. In order to simulate the downward movement of the frost table, a simple heat‐conduction model was proposed and compared to field data from a wet, organic‐covered watershed in a discontinuous permafrost region of Canada. Ground heat flux was measured simultaneously using the calorimetric, gradient, and flux‐plate methods to increase the confidence in data sets. The majority (>86%) of ground heat flux was used to melt the ice in frozen soil, and the soil temperature had a linear profile from the ground surface to the frost table when averaged over several days. Assuming a linear temperature profile, the proposed method calculates the daily rate of thawing from ground surface temperature and bulk thermal conductivity, where the latter is essentially determined by soil water content. Simulated depths to the frost table during three thaw seasons (2003–2005) matched closely with the observed data for two contrasting ground‐cover types with distinctly different thaw rates. The method can be easily implemented in hydrological models, and will provide a useful tool for simulating hillslope drainage in organic‐covered permafrost terrains, and for evaluating the effects of topography and land cover on the temporal and seasonal variability of the frost table. Copyright © 2007 John Wiley & Sons, Ltd.
Characterization of the interplay between the main factors contributing to lipoplex‐mediated transfection in cell cultures
Authors: Boktov Julia , Hirsch‐Lerner Danielle , Barenholz Yechezkel
Published: August 2007

Transfection efficiency of lipoplex‐mediated gene delivery is multifactorial. However, the mode of interaction between the factors which affect transfection is not fully understood. To help fill this deficiency we evaluated the effect of the interplay between several variables that affect transfection efficiency in cell cultures. For this, we applied the Analysis of Variance Model with Fixed Effects and Repeated Measures to assess the data. The variables studied include: two different genes, Luc, and human growth hormone (hGH), in three different plasmids (two of which contain the luciferase (Luc) gene, but different promoter‐enhancer regions (CMV and H19) and one plasmid coding hGH with a S16 promoter); three topoisoforms of pDNA (supercoiled (SC), open circular (OC), and closed circular (CC)); three cationic lipid compositions, all based on the monocationic lipid DOTAP (100% DOTAP, DOTAP/DOPE 1 : 1, and DOTAP/cholesterol 1 : 1, all ratios are mole ratios); two DNA−/L+ charge ratios (0.2 and 0.5); and two cell lines (NIH 3T3 and MBT‐2). Our statistical analysis confirmed that the cell type, the gene used for transfection, the promoter type, the type of helper lipid, and DNA−/DOTAP+ charge ratio, all affect transfection efficiency in a statistically significant manner. The most efficient lipoplex formulation in both cell lines was that based on DOTAP (without helper lipid), having CC plasmid DNA. We suggest that for obtaining the most transfection‐efficient lipoplex one should select the best topoisoform of pDNA for each particular cell type, and complex it with cationic liposomes having optimal lipid composition. Copyright © 2007 John Wiley & Sons, Ltd.
Continuum modeling of large networks
Authors: Chong Edwin K. P. , Estep Donald , Hannig Jan
Published: August 2007

This paper is concerned with the modeling and simulation of extremely large networks. We derive a time‐dependent diffusion–convection partial differential equation, the solution of which captures the global characteristics of a stochastic network model. Continuum modeling provides a powerful way to deal with the number of components in large networks and opens up the use of highly sophisticated mathematical tools such as adaptive finite element methods. This, in turn, makes it possible to carry out—with reasonable computational burden even for very large systems—network performance evaluation and prototyping, network design, systematic parameter studies, and optimization of network characteristics. Copyright © 2007 John Wiley & Sons, Ltd.
Hydrometeorological analysis of northwestern Turkey with links to climate change
Authors: Aksoy Hafzullah , Unal N. Erdem , Alexandrov Vesselin , Dakova Snejana , Yoon Jaeyoung
Published: August 2007

Precipitation, air temperature, and streamflow data from the European part of Turkey are analysed by means of a set of tests available in the hydrometeorological literature. Structural characteristics such as randomness, jump, trend, and a best‐fit probability distribution function are determined. Concluding remarks related to the structural characteristics of hydrometeorological data state that no significant trend and jump exist in the time series, and the best‐fit probability distribution function is the gamma for the streamflow data. Climate change scenarios based on ECHAM4 as well as HadCM2 and HadCM3 global circulation models are developed for the region, and projections are made for the 21st century. Projections made by climate change scenarios signal higher air temperature and lower precipitation in the 21st century and warn for severe extremes, higher maxima and lower minima, both in time and space. Copyright © 2007 Royal Meteorological Society
Variability and trends in indices of quality‐controlled daily temperature extremes in Uruguay
Authors: Rusticucci Matilde , Renom Madeleine
Published: August 2007

A database of daily extreme temperature was created for as many stations as possible for Uruguay, as far back as possible. This is the first attempt to gather all the different data sources together, perform a quality control and homogeneity assessment. We work with seven stations; it should be taken into account that Uruguay is a small country (around 177 000 km2) and this represents most of the available data. There are three old series with starting dates in 1930, and four that start around 1950. From this database, a set of four extreme temperature indices was constructed for the oldest five stations, warm days (TX90), cold days (TX10), warm nights (TN90) and cold nights (TN10).

The index TN10 shows the largest significant negative trend for the period 1960–2002, while TN90 shows a positive but not significant trend for this period indicating a strong warming of nighttime temperature. A spectral analysis was performed using the multi taper methods (MTM) to the de‐trended annual, summer Dec–Feb (DJF) and winter Jun–Aug (JJA) indices time‐series. This analysis shows that on inter‐annual timescales, the most significant range of frequencies is from 2 to 2.5 years and from 3 to 6 years. Low frequencies of variability were detected when the MTM was applied to de‐trended smoothed annual time‐series, around the range of frequencies of 15–25 years for almost all the indices analysed. Links with global sea surface temperature (SST) were studied for two stations (Paysandu and Rocha), and it was found that the indices showed largest correlations with SST anomalies in the Pacific Ocean. We detected changes in the response of the TN10 index for Rocha station when the series was split up into two different periods (1942–1976 and 1977–2005). Copyright © 2007 Royal Meteorological Society
A Raman spectroscopic study of the uranyl carbonate rutherfordine
Authors: Frost Ray L. , Čejka Jiří
Published: August 2007

The molecular structure of the uranyl mineral rutherfordine has been investigated by the measurement of its Raman spectra at 298 and 77 K and complemented with infrared spectra. The infrared spectra of the (CO3)2− units in the anti‐symmetric stretching region show complexity with three sets of carbonate bands observed. This, combined with the observation of multiple bands in the (CO3)2− bending region in both Raman and IR spectra, suggests that both monodentate and bidentate (CO3)2− units are present in the structure in accordance with the X‐ray crystallographic studies. Complexity is also observed in the IR spectra of (UO2)2+ anti‐symmetric stretching region and is attributed to non‐identical UO bonds. Both Raman and infrared spectra of the rutherfordine show the presence of both water and hydroxyl units in the structure, as evidenced by IR bands at 3562 and 3465 cm−1 (OH) and 3343, 3185 and 2980 cm−1 (H2O). Raman spectra show the presence of four sharp bands at 3511, 3460, 3329 and 3151 cm−1. Copyright © 2007 John Wiley & Sons, Ltd.
Raman spectroscopic studies of the corrosion of model iron electrodes in sodium chloride solution
Authors: Larroumet Damien , Greenfield David , Akid Robert , Yarwood Jack
Published: August 2007

We have explored the un‐enhanced Raman spectra of both single and twin electrodes in 3.5% NaCl solution (at ambient temperatures) over a range of applied potentials (between 20 and 200 mV) and times (between 0 and 5 h). Under these conditions, we observed the initial formation of ‘green rust’ (hydroxychlorides and/or hydroxycarbonates), followed by the formation of magnetite (Fe3O4) and then a mixture of the α‐ and γ‐FeOOH (goethite and lepidocrocite, respectively). These data are consistent with a model for corrosion during which the initially formed magnetite is either covered, or replaced, by layers of the FeOOH oxidation products. Fitting of the data as a function of time and potential shows that, although the product range is independent of potential, the relative kinetics of formation of magnetite and its subsequent conversion to the γ‐FeOOH were potential and time dependent. Analysis by mapping of the dry corroded surface showed a variety of species, including green rust, some Fe(OH)3, as well as the γ‐FeOOH, and possibly some β‐FeOOH. But no surface magnetite was found, indicating that this material had been either covered up or converted to FeOOH. We noted several complications during this work, including the interference of resonance effects (on the Raman intensities) and the heterogeneity of the corrosion process (and hence distribution of species on the corroded surface). However, we believe that the use of un‐enhanced Raman methods has led to conclusions more likely to be relevant to ‘real’ corrosion processes. Copyright © 2007 John Wiley & Sons, Ltd.
Radio‐guided surgery in neuroendocrine tumors
Authors: Gulec Seza A , Baum Richard
Published: August 2007

The majority of Neuroendocrine tumors (NET) express somatostatin (SS) receptors, and thus can be successfully targeted with radiolabeled SS analogs in vivo. Somatostatin receptor scintigraphy (SRS) with 111In‐DTPA Octreotide is the main imaging technique for evaluation of NETs. Radio‐guided surgery for NETs, therefore, primarily utilizes 111In‐DTPA Octreotide tumor localization mechanism and kinetics. Somatostatin analog radiopharmacy continues to evolve to include the development of more selective and higher affinity analogs and PET tracers. These changes are expected to open new venues for radio‐guided surgery technology. J. Surg. Oncol. 2007;96:309–315. © 2007 Wiley‐Liss, Inc.
Radioimmunoguided surgery (RIGS), PET/CT image‐guided surgery, and fluorescence image‐guided surgery: Past, present, and future
Authors: Sun Duxin , Bloomston Mark , Hinkle George , Al‐Saif Osama Habib , Hall Nathan C. , Povoski Stephen P. , Arnold Mark W. , Martin Edward W.
Published: August 2007

125I‐labeled anti‐TAG‐72 antibodies were applied in radioimmunoguided surgery (RIGS) to remove gross and occult tumors. It is challenging to handle 125I‐labeled materials. PET/CT image‐guided surgery utilizes 18FDG to monitor the biochemical activity of the tumor and to integrate pre‐ and postoperative imaging for complete tumor removal. PET/CT image‐guided surgery only detects later stage disease. Fluorescence image‐guided surgery using anti‐TAG‐72 antibodies may provide opportunities for intraoperative cancer detection of both gross and occult tumors. J. Surg. Oncol. 2007;96:297–308. © 2007 Wiley‐Liss, Inc.
The formation of the tourist's loyalty to the tourism distribution channel: how does it affect price discounts?
Authors: Campo Sara , Yagüe Maria Jesús
Published: August 2007

Given that distribution agents who wish to maximize long‐term business profits should not only attract new consumers but also keep them loyal, this study analyses the variables that determine the consumer's loyalty to distribution agents for tourism. Although retailers in the service industry employ price discounts on products to motivate short‐term sales, they often establish promotional policies without considering their effect on the long‐term business results. This paper presents an empirical study of the effect of price promotions on tourists who travelled with a package tour. The results indicate that price discounts do not erode consumer loyalty directly, and that the key to obtaining loyal consumers is to offer package tours that customers perceive as providing high‐quality service. Copyright © 2007 John Wiley & Sons, Ltd.
Community development using a sustainable tourism strategy: a case study of the Jordan River Valley touristway
Authors: Shunnaq Mohammed , Schwab William A. , Reid Margaret F.
Published: August 2007

This paper presents the results of a 10‐year collaboration among Yarmouk University, the University of Arkansas and the Jordanian government to develop a sustainable tourism strategy against the backdrop of political and economic uncertainty. It reports our efforts to develop a touristway through the Jordan River Valley that integrates the valley's heritage, archeology, and Christian and Islamic religious sites. It also analyses our community development work in Umm Qais, the touristway's northern anchor, and how our plan contributes to Northern Jordan's economic development. We conclude with a discussion of the specific insights gained from our experiences that may serve others addressing similar issues. Copyright © 2007 John Wiley & Sons, Ltd.
Rheology of a Polymer‐Based Hybrid Suspension Composed of Concentrated Poly[(D,L‐lactide)‐co‐glycolide] Solution and Inorganic Salt Particles
Authors: Jing Dianying , Ding Jiandong
Published: August 2007

Suspensions composed of a solution of a biodegradable polyester in a volatile organic solvent, and solid inorganic particles of size in the order of hundreds of microns have been very important in the fabrication of porous scaffolds in the field of tissue engineering. This article reports the basic rheological investigations of this complex fluid type. A Couette geometry covered by silicon oil was found to be an appropriate geometry to retain stability of the rheological measurements. Suspension viscosity increased with the particle volume fraction, and the extent of the increase was much larger than that predicted by the Einstein suspension equation. Both start‐up dynamics at the inception of steady shear and relaxation after an abrupt change of oscillatory shear frequency in the suspension showed significantly different behaviors from those in the associated polymer solution. Particle reorganization upon change of rheological state was anticipated.

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Does santa have a great job? Gift shopping value and satisfaction
Authors: Babin Barry J. , Gonzalez Christine , Watts Christina
Published: August 2007

For good or bad, shopping and gifting are intertwined. This research looks at sources of gratification associated with shopping for gifts. More particularly, the roles played by general and specific shopping orientations in shaping gift shopping value and satisfaction are examined. Results from testing a theoretical model suggest that gift shopping orientations, such as agape, may dominate general shopping orientations, such as price consciousness. Also, the important role played by utilitarian shopping value is consistent with gift shopping more as a job than as a source of leisure. However, the results fall short of suggesting a negative relationship between gift shopping and hedonic shopping value. So gift shopping may be a job, but a job that is not so horrible after all. © 2007 Wiley Periodicals, Inc.
Natural and Synthetic Polyampholytes, 2
Authors: Kudaibergenov Sarkyt E. , Ciferri Alberto
Published: August 2007

The ability of natural and synthetic polyampholytes to exist in globular, coil, helix, stretched, and ordered conformations is reviewed and transformations and transitions between the respective states upon variation of conditions are highlighted. The properties of polyampholytes in solution, condensed, and gel state as well as at various interfaces are discussed in order to clarify the principles of the structural organization of proteins, model the function of biomembranes, and study the biocompatibility of modified materials. Application aspects of polyampholytes in protein separation, desalination, catalysis, the oil industry, biotechnology, nanotechnology, and medicine are given.

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A Fourier–Karhunen–Loève discretization scheme for stationary random material properties in SFEM
Authors: Li C. F. , Feng Y. T. , Owen D. R. J. , Li D. F. , Davis I. M.
Published: August 2007

In order to overcome the computational difficulties in Karhunen–Loève (K–L) expansions of stationary random material properties in stochastic finite element method (SFEM) analysis, a Fourier–Karhunen–Loève (F–K–L) discretization scheme is developed in this paper, by following the harmonic essence of stationary random material properties and solving a series of specific technical challenges encountered in its development. Three numerical examples are employed to investigate the overall performance of the new discretization scheme and to demonstrate its use in practical SFEM simulations. The proposed F–K–L discretization scheme exhibits a number of advantages over the widely used K–L expansion scheme based on FE meshes, including better computational efficiency in terms of memory and CPU time, convenient a priori error‐control mechanism, better approximation accuracy of random material properties, explicit methods for predicting the associated eigenvalue decay speed and geometrical compatibility for random medium bodies of different shapes. Copyright © 2007 John Wiley & Sons, Ltd.
Direct chemiluminescent imaging detection of human serum proteins in two‐dimensional polyacrylamide gel electrophoresis
Authors: Tao Qian , Wang Zhenzhen , Zhao Heping , Baeyens Willy R. G. , Delanghe Joris R. , Huang Lingyun , Ouyang Jin , He Dacheng , Zhang Xianhua
Published: August 2007

A novel chemiluminescence (CL)‐based imaging method capable of directly detecting proteins in polyacrylamide gels after electrophoresis is proposed. Human serum proteins are presently detected by a direct CL imaging method after native 2‐D PAGE. As a consequence, some proteins, including haptoglobin (Hp), Hp precursor, hemopexin (Hpx) precursor, Ig alpha‐1 chain C region, and Complement C3 precursor can be detected and identified by MS and MS/MS techniques. These proteins are all acute phase proteins, which have been defined as biomarkers for certain diseases. Moreover, serum proteins from healthy people and cirrhotic patients were analyzed. A decrease in Hp spots for cirrhotic patients could be confirmed. The CL imaging conditions were optimized, including the concentrations of H2O2 and luminol. The process of CL detection of proteins is simple, and there is no need for specialized equipment. In comparison with the traditional CBB‐R250 staining method, the detection sensitivity was improved and the detection period decreased about 70 times. Hence, this technique possesses potentials as a rapid, convenient, and inexpensive analytical technique for protein detection and for the diagnosis of diseases.
Rap2 regulates androgen sensitivity in human prostate cancer cells
Authors: Bigler Dora , Gioeli Daniel , Conaway Mark R. , Weber Michael J. , Theodorescu Dan
Published: August 2007

BACKGROUND

Progression of prostate cancer to a fatal androgen‐independent disease is associated with activation of MAP kinase, consistent with chronic stimulation of the Ras‐signaling pathway. We have previously shown that Ras activation is sufficient to induce androgen‐independent growth of prostate cancer cells. One mechanism of MAP kinase regulation is modulation of Ras signaling by other Ras family members, the Rap gene paralogs Rap1a/b and Rap2a/b. Here we ask if Rap proteins play a role in determining androgen sensitivity of human prostate cancer cells either alone or in the context of an activated Ras.

METHODS

To evaluate the role of Rap proteins in androgen responsiveness we use Rap over‐expression with or without mutated Ras co‐transfection and Rap siRNA knockdown to evaluate androgen‐dependent prostate‐specific antigen (PSA) promoter reporter expression and cell growth in androgen‐dependent LNCaP and independent C4‐2 human prostate cancer cells.

RESULTS

Rap1 is equally expressed between LNCaP and C4‐2 cells and thus we focused on Rap2 which is minimally expressed in C4‐2. Rap2a affects androgen‐dependent PSA reporter expression in a dose‐dependent manner in LNCaP and C4‐2 cells. Low levels of Rap2a enhance PSA reporter expression, whereas higher concentrations inhibit expression. We show that Rap2a antagonizes the enhanced PSA reporter expression conferred by an active RasV12 gene in prostate cancer cells. siRNA knockdown data indicate that Rap2 has a greater effect on androgen‐stimulated growth in LNCaP than in C4‐2 cells.

CONCLUSIONS

We show that Rap2 is involved in androgen‐mediated transcriptional and growth responses of human prostate cancer cells. Prostate 67: 1590–1599, 2007. © 2007 Wiley‐Liss, Inc.
Integrated self‐aligned conjugated polymer fiber laser devices
Authors: Gaal Martin , List Emil J. W.
Published: August 2007

In this letter we present a fully integrated self‐aligned distributed feedback (DFB) fiber laser device, which was directly imprinted in the conjugated polymer poly[2‐methoxy‐5 (2‐ethyl‐hexyloxy)‐1,4‐phenylenevinylene] (MEH‐PPV) on the top of optical fibers by using the soft lithographic technique of “liquid imprinting”. For this process master gratings (360 and 380 nm) for the feedback structure were fabricated via e‐beam lithography, transferred to an elastomeric stamp and used to imprint the grating into the highly luminescent conjugated polymer. Such second order gratings were photo‐pumped with a frequency doubled Nd:YAG laser, the laser emission (around 640 nm, depending on the used grating) was directly coupled into the waveguide and detected via a CCD spectrometer at the end of the fiber. The threshold of the laser devices was found to be in the range of 4.3 mJ/cm2 and exhibited a line width of approximately 2 nm. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
In vitro activity of an essential oil against Leishmania donovani
Authors: Monzote L. , García M. , Montalvo A. M. , Scull R. , Miranda M. , Abreu J.
Published: August 2007

The in vitro antileishmanial effect of the essential oil from Chenopodium ambrosioides against Leishmania donovani was investigated. The product showed significant activity against promastigotes and amastigotes, with a 50% effective concentration of 4.45 and 5.1 µg/mL, respectively. The essential oil caused an irreversible inhibition of the growth of promastigotes after a treatment with 100 or 10 µg/mL for 1 or 24 h, respectively. The phagocytic activity of the macrophages was preserved at a concentration toxic to the parasite. The essential oil from C. ambrosioides may be a potential candidate drug to development a new agent to combat this parasitic disease. Copyright © 2007 John Wiley & Sons, Ltd.
Antibacterial activity of Chamomilla recutita oil extract against Helicobacter pylori
Authors: Shikov Alexander N. , Pozharitskaya Olga N. , Makarov Valery G. , Kvetnaya Asya S.
Published: August 2007

The antibacterial activity of an oil extract of Chamomilla recutita flowers against Helicobacter pylori (H. pylori) was evaluated by the agar dilution method using Colombia agar with 10% sheep blood, an inoculum of McFarland 0.5 and incubation in an anaerobic atmosphere at 37 °C for 3 days. The oil extract was prepared by olive oil extraction of Chamomilla recutita flowers using rotary pulsation. The MIC90 (minimal inhibitory concentration) and MIC50 were 125 mg/mL and 62.5 mg/mL, respectively. It was shown that the Chamomilla recutita oil extract inhibited the production of urease by H. pylori. In addition, it was found that the morphological and fermentative properties of H. pylori were affected by application of the Chamomilla recutita oil extract. Copyright © 2007 John Wiley & Sons, Ltd.
Antifibrotic effects of a herbal combination regimen on hepatic fibrotic rats
Authors: Lin Yun‐Lian , Hsu Yi‐Chao , Chiu Yung‐Tsung , Huang Yi‐Tsau
Published: August 2007

Liver fibrosis has been characterized as chronic inflammatory processes involving multiple molecular pathogenetic pathways. This therapeutic study investigated whether a combination regimen of Salvia miltiorrhiza (S), Ligusticum chuanxiong (L) and Glycyrrhiza glabra (G) exerted in vivo antifibrotic effects on rats with hepatic fibrosis. Fibrosis was induced in rats by dimethylnitrosamine (DMN) administration for 4 weeks. Fibrotic rats were randomly assigned to one of the three groups: control, SLG (50 mg/kg) or silymarin (50 mg/kg), each given by gavage twice daily for 3 weeks starting 1 week after DMN injection. The results showed that fibrosis scores of livers from DMN‐treated rats with SLG (1.13 ± 0.13) were significantly reduced in comparison with DMN‐treated rats receiving vehicle (1.63 ± 0.18). Moreover, the hepatic collagen content of DMN rats was significantly reduced by either SLG or silymarin treatment. The double immunohistochemical staining results also showed that α‐SMA positive cells with NFκB nuclear translocation were decreased in the fibrotic livers by SLG and silymarin treatments. The mRNA expression levels of TGF‐β1, α‐SMA, collagen1α2, iNOS and ICAM‐1 genes were attenuated by SLG and silymarin treatment. The results showed that SLG exerted antifibrotic effects in rats with DMN‐induced hepatic fibrosis. Copyright © 2007 John Wiley & Sons, Ltd.
Anticonvulsant activity of Hypoxis hemerocallidea Fisch. & C. A. Mey. (Hypoxidaceae) corm (‘African potato’) aqueous extract in mice
Authors: Ojewole John A. O.
Published: August 2007

Extracts of Hypoxis hemerocallidea Fisch. & C. A. Mey. (Hypoxidaceae) corm (popularly known as ‘African potato’) are extensively used in South African traditional medicines for the treatment, management and/or control of an array of human ailments, including childhood convulsions and epilepsy. This study examined the anticonvulsant activity of the plant's corm aqueous extract (APE, 50–800 mg/kg i.p.) against pentylenetetrazole (PTZ)‐, picrotoxin (PCT)‐ and bicuculline (BCL)‐induced seizures in mice. Phenobarbitone and diazepam were used as reference anticonvulsant drugs for comparison. Like the reference antiseizure drugs used, Hypoxis hemerocallidea corm aqueous extract (APE, 100–800 mg/kg i.p.) significantly delayed (p < 0.05–0.001) the onset of, and antagonized, pentylenetetrazole (PTZ)‐induced seizures. The plant's corm aqueous extract (APE, 100–800 mg/kg i.p.) also profoundly antagonized picrotoxin (PCT)‐induced seizures, but only weakly antagonized bicuculline (BCL)‐induced seizures. Although the data obtained in the present study do not provide conclusive evidence, it would appear that ‘African potato’ aqueous extract (APE) produces its antiseizure effect by enhancing GABAergic neurotransmission and/or action in the brain. The results of this laboratory animal study indicate that APE possesses anticonvulsant activity in the mammalian experimental model used and, therefore, tend to suggest that the herb may be used as a natural supplementary remedy in the management, control and/or treatment of childhood convulsions and epilepsy. In conclusion, the findings of this study indicate that Hypoxis hemerocallidea corm aqueous extract possesses anticonvulsant activity, and thus lend pharmacological credence to the suggested folkloric, anecdotal ethnomedical uses of the herb in the management of childhood convulsions and epilepsy in some rural communities of South Africa. Copyright © 2007 John Wiley & Sons, Ltd.
XPS investigations of ink‐jet printed paper
Authors: Lützenkirchen‐Hecht Dirk , Rohrmann Kay , Stöcker Thomas , Thiel Wolfgang
Published: August 2007

Different ink‐jet printed paper materials were investigated using X‐ray photoelectron spectroscopy (XPS) yielding the elemental composition of the near‐surface region of the papers. We found significant differences with respect to the detected elements and their atomic concentrations in the different inks studied here. Two different groups of inks could be identified by means of a lower ratio of the O and C atomic concentrations and lower concentrations in specific trace elements like Mg, Na and Si. High‐resolution spectra of C 1s and O 1s core levels allowed a detailed determination of the chemical state of the respective elements. On the basis of a detailed deconvolution of these XPS signals, significant differences between all the investigated ink‐jet printed papers were found, thereby allowing their discrimination. The applicability of the measurements and, more generally, the XPS technique for forensic investigations of paper are discussed. Copyright © 2007 John Wiley & Sons, Ltd.
Randomization with a posteriori constraints: Description and properties
Authors: Gicquel Stéphanie , Marion‐Gallois Roland
Published: August 2007

The use of randomization for assigning patients to treatment groups in clinical trials is firmly acknowledged as providing the best quality results.

Two standard methods are used in order to achieve well‐balanced groups with respect to prognostic factors (i.e. factors influencing the disease outcome): stratification and minimization. Stratification is recommended when the number of strata is not too high—otherwise, minimization is preferred. However, minimization may compromise blinding (since the search for balance is performed a priori) and, furthermore, use of the technique has been questioned by the European Agency for the Evaluation of Medicinal Products. We have developed a new procedure for adaptive randomization, which we have named ‘randomization with a posteriori constraints’. By using a search for balance a posteriori, this procedure ensures that patient groups are similar with respect to prognostic factors while being less vulnerable to selection bias. The aim of this work was to describe the new method and to compare it (using simulations) with stratification and minimization.

In the case of trials with few
prognostic factors, the recourse to minimization or ‘randomization with a posteriori constraints’ does not appear to be useful. In such a context, stratification has suitable properties and its simplicity of implementation encourages its use. However, when the number of prognostic factors is higher, ‘randomization with a posteriori constraints’ is less predictable than minimization and the chance of imbalance is lower than for stratification. In conclusion, ‘randomization with a posteriori constraints’ with an adequate threshold seems to be a good compromise between minimization and stratification. Copyright © 2007 John Wiley & Sons, Ltd.
Sensitivity analysis of intention‐to‐treat estimates when withdrawals are related to unobserved compliance status
Authors: Salim Agus , Mackinnon Andrew , Griffiths Kathleen
Published: August 2007

In the presence of dropout, intent(ion)‐to‐treat analysis is usually carried out using methods that assume a missing‐at‐random (MAR) dropout mechanism. We investigate the potential bias caused by assuming MAR when the dropout is related to unobserved compliance status. A framework to assess the magnitude of bias in the context of pre‐ and post‐test design (PPD) with two treatment arms is presented. Scenarios with all‐or‐none and partial compliance level are investigated. Using two simulated data sets and actual data from an e‐mental health trial, we demonstrate the utility of sensitivity analyses to assess the bias magnitude and show that they are plausible options when some knowledge of compliance behaviour in the dropout exists. We recommend that our approach be used in conjunction with methods of analysis which assume MAR in estimating the ITT effect. Copyright © 2007 John Wiley & Sons, Ltd.
Experiences with building an intrusion‐tolerant group communication system
Authors: Ramasamy HariGovind V. , Pandey Prashant , Cukier Michel , Sanders William H.
Published: August 2007

There are many group communication systems (GCSs) that provide consistent group membership and reliable, ordered multicast properties in the presence of crash faults. However, relatively few GCS implementations are able to provide these properties in the presence of malicious faults resulting from intrusions. We describe the systematic transformation of a crash‐tolerant GCS, namely C‐Ensemble, into an intrusion‐tolerant GCS, the ITUA GCS. To perform the transformation, we devised intrusion‐tolerant versions of key group communication protocols. We then inserted implementations of the protocols into C‐Ensemble and made significant changes to the rest of the C‐Ensemble protocol stack to make the stack intrusion tolerant. We quantify the cost of providing intrusion‐tolerant group communication in two ways. First, we quantify the implementation effort by presenting a detailed analysis of the amount of change required to the original C‐Ensemble system. In doing so, we provide insight into the choice of building an intrusion‐tolerant GCS from scratch versus building one by leveraging a crash‐tolerant implementation. Second, we quantify the run‐time performance cost of tolerating intrusions by presenting results from an experimental evaluation of the main intrusion‐tolerant microprotocols. The results are analyzed to identify the parts that contribute the most overhead while providing intrusion tolerance during both normal operation and recovery from intrusions. Copyright © 2007 John Wiley & Sons, Ltd.
Toward a cross‐cultural theory of “exemplary organizations”: Evidence from Cuba
Authors: Cunha Miguel Pinae , Cunha Rita Campose , Rego Arménio
Published: August 2007

Management interest in “good companies to work for,” or “exemplary organizations,” has attracted the interest of researchers in the United States and Europe. We contribute to the literature on exemplary organizations by studying the representation of “exemplary organizations” in an unusual context, Cuba, and by inviting scholars to explore the cross‐cultural differences between what in different countries is viewed as an exemplary organization. Until now, studies on the best companies to work for have focused on companies operating in capitalistic economies. We aim to develop a better understanding of the representation of what a good place might be in an economic and ideological context that is in sharp contrast with the contexts in which this theme has been studied previously. © 2007 Wiley Periodicals, Inc.
Localized advantage in a global economy: The case of Bangalore
Authors: Nair Anil , Ahlstrom David , Filer Larry
Published: August 2007

This article examines how and why firms in Bangalore, a city in southern India, have achieved success in the global software industry. We use Porter's “diamond framework” to analyze information obtained from secondary sources and interviews with engineers, managers, and top executives from software firms and officials involved in Bangalore's development. While we found some aspects of the case conform to Porter's framework, many other elements tend to diverge from the model. Thus, the article contributes to the Porter's diamond model literature by extending its application to assessing the development of successful regions in knowledge‐based industries in developing economies. The discussion in the article would be of value to officials interested in creating such successful regions, as well as international business executives interested in the opportunities afforded by locating in these regions. © 2007 Wiley Periodicals, Inc.
New Doppler index for prediction of perinatal brain damage in growth‐restricted and hypoxic fetuses
Authors: Jugović D. , Tumbri J. , Medić M. , Jukić M. Kušan , Kurjak A. , Arbeille P. , Salihagić‐Kadić A.
Published: August 2007

Objective

To evaluate the new vascular score, hypoxia index (HI), in the prediction of sonographically detected structural brain lesions in neonates within the first week after delivery of growth‐restricted fetuses.

Methods

This prospective study included 29 growth‐restricted fetuses delivered between 31 and 40 gestational weeks. Doppler umbilical artery (UA) and middle cerebral artery (MCA) resistance indices (RI) were recorded at 48‐h intervals for at least 2 weeks before delivery. The cerebroumbilical ratio (C/U ratio = MCA‐RI/UA‐RI) and the HI (the sum of the daily reductions in C/U ratio, i.e. percentage below the cut‐off value of 1, over the period of observation) were calculated. After delivery, neonatal outcome was evaluated according to obstetric parameters and ultrasound examinations of the brain. Doppler indices, C/U ratio and HI, as well as neonatal clinical and biochemical parameters, were tested as potential predictors of brain lesions using the C4.5 data‐mining algorithm.

Results

Neonatal brain lesions were detected in 13 growth‐restricted fetuses. Of all the parameters tested by the C4.5 data‐mining algorithm, only HI was identified as a predictor of neonatal brain lesions. HI also showed better correlation with neonatal biochemical parameters, such as umbilical venous partial pressure of oxygen and umbilical venous pH, compared with the C/U ratio.

Conclusions

HI, which takes into account cumulative oxygen deficit, could significantly improve the prediction of a poor neurological outcome in pregnancies complicated by growth restriction and hypoxia. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.
Fish otolith trace element maps: new approaches with synchrotron microbeam x‐ray fluorescence
Authors: Limburg Karin E. , Huang Rong , Bilderback Donald H.
Published: August 2007

Otoliths, the carbonate earstones of fishes, take up minor and trace amounts of elements as they accrete through a fish's life. We apply synchrotron microbeam x‐ray fluorescence methods to establish a breakthrough in high‐resolution, simultaneous area mapping of multiple trace elements in otoliths, with spatial resolution down to 20 µm and trace element detection down into the part per million range for multiple elements. Concentration maps of Ca, Sr, Zn and, for the first time, Ba, Mn, and Se are obtained simultaneously. Combinations of these elemental maps provide new insights into the environmental history of fishes and their lifetime movements, illustrated by several case studies. This method helps pave the way toward improved spatial analysis of otolith microchemistry. Copyright © 2007 John Wiley & Sons, Ltd.
Expression of Candida albicans Sfu1 in fission yeast complements the loss of the iron‐regulatory transcription factor Fep1 and requires Tup co‐repressors
Authors: Pelletier Benoit , Mercier Alexandre , Durand Mathieu , Peter Chardeen , Jbel Mehdi , Beaudoin Jude , Labbé Simon
Published: August 2007

The opportunistic pathogenic yeast Candida albicans contains a gene which encodes a putative member of the iron‐regulatory GATA factor protein family. This protein, referred to as suppressor of ferric uptake (Sfu1), has two Cys2/Cys2‐type zinc finger domains separated by a conserved Cys‐rich region. In Schizosaccharomyces pombe, the GATA‐type transcription factor Fe protein 1 (Fep1) represses target gene expression when iron levels exceed those needed by the cell. To ascertain the functional similarity between Sfu1 and Fep1, the C. albicans Sfu1 was expressed in Sz. pombe cells lacking the endogenous fep1+ gene. We determined that Sfu1 is capable of suppressing iron‐related phenotypes of fep1Δ mutant cells. Using a functional SFU1–GFP fusion allele, the Sfu1 protein was localized to the nucleus under both iron‐replete and iron‐starved conditions. Sfu1 effectively regulated the expression of genes encoding components of the reductive and non‐reductive iron transport systems. Furthermore, the iron‐responsive regulation mediated by Sfu1 was GATA‐dependent. The N‐terminal 250 amino acid segment of Sfu1 expressed in and purified from Escherichia coli specifically associated with the hexanucleotide sequence AGATAA in an iron‐dependent manner. On the other hand, expression of the full‐length C. albicans Sfu1 in Sz. pombe fep1Δ tup11Δ tup12Δ triple mutant cells failed to repress target gene expression under conditions of high iron concentration. Using two‐hybrid analysis, we demonstrated that Tup11 and Tup12 physically interacted with Sfu1. Taken together, these results reveal a remarkable functional conservation between Sfu1 from C. albicans and Fep1 from Sz. pombe in their ability to sense excess iron and respond by repressing target gene transcription. Copyright © 2007 John Wiley & Sons, Ltd.
Lymph Node Metastasis Density and Growth Pattern as Independent Prognostic Factors in Advanced Esophageal Squamous Cell Carcinoma
Authors: Ooki Akira , Yamashita Keishi , Kobayashi Nobuyuki , Katada Natsuya , Sakuramoto Shinichi , Kikuchi Shiroh , Watanabe Masahiko
Published: August 2007

Background

Esophageal cancer is one of the leading types of cancer, and it is a particularly deadly form of malignancy. TNM classification is the most common staging system, but it has been reported that prognosis is not reflected adequately by this classification. The purpose of this study was to clarify independent prognostic factors in esophageal squamous cell carcinoma (ESCC), a dominant type of esophageal cancer in Japan, to broaden the staging system to improve its predictive value. Thus staging could be expanded to make the prognosis a valuable clinical tool, and to improve knowledge of the biological traits of advanced ESCC.

Methods

The present study included 121 patients with advanced ESCC (stage II to IVA) treated by esophagectomy between 1990 and 2003 at the Kitasato University Higashi Hospital.

Results

Univariate prognostic analysis of the disease‐specific survival revealed that TNM stage (p < 0.0001), lymph node metastasis density over 10% (ND10; p < 0.0001), R‐category (p = 0.003), intramural metastasis within the esophagus (IM; p = 0.009), growth pattern (p = 0.01), and size of tumor (p = 0.02) were significantly associated with a poor outcome in advanced ESCC. Multivariate analysis confirmed that growth pattern (p = 0.02, HR = 3.1) and ND10 (p = 0.02, HR = 2.0) were finally remnant prognostic factors independent of TNM stage. Growth pattern was prominent in stage II, whereas ND10 was directly proportional to stage progression and characteristics to stage IV disease. Interestingly, ND20, the most malignant phenotype of ESCC, was the only prognostic determinant, even in stage IV disease.

Conclusions

From the present study, we concluded that progression of lymph node density is characteristic of a life‐threatening phenotype of advanced ESCC, and it should be employed as a therapeutic target to improve patient survival. Growth pattern is an alternative target characteristic of less advanced ESCC. Both of these parameters may be applied as useful clinical tools in the management of patients with advanced esophageal cancer.
An Organic Metal/Silver Nanoparticle Finish on Copper for Efficient Passivation and Solderability Preservation
Authors: Wessling Bernhard , Thun Marco , Arribas-Sanchez Carmen , Gleeson Sussane , Posdorfer Joerg , Rischka Melanie , Zeysing Bjoern
Published: August 2007

For the first time, a complex formed by polyaniline (in its organic metal form) and silver has been deposited on copper in nanoparticulate form. When depositing on Cu pads of printed circuit boards it efficiently protects against oxidation and preserves its solderability. The deposited layer has a thickness of only nominally 50 nm, containing the Organic Metal (conductive polymer), polyaniline, and silver. With >90% (by volume), polyaniline (PAni) is the major component of the deposited layer, Ag is present equivalent to a 4 nm thickness. The Pani–Ag complex is deposited on Cu in form of about 100 nm small particles. Morphology, electrochemical characteristics, anti-oxidation and solderability results are reported.
The Effects of Softeners on the Properties of Sulfur‐Dyed Cotton Fibers
Authors: Parvinzadeh Mazeyar
Published: August 2007

The processing of textiles to achieve a particular handle is one of the most important aspects of finishing technology. Softeners can improve some properties of textiles, depending on the chemical nature, including soft handle, smoothness, elasticity, hydrophilic, antistatic and soil release properties. They can affect the color and fastness of the dyed textile. In this research project, cotton fabrics were first scoured with nonionic detergent and then dyed with four sulfur dyes of different structures. The colors of the dyed fabrics was yellow, bluish black and bright blue. The dyed fabrics were then treated with anionic, cationic, nonionic, micro and macro silicone softeners. Nonionic, micro and macro silicone softeners decreased the lightness (L*) of all sulfur‐dyed samples while anionic and cationic softeners caused only a slight alteration in lightness. The a*, b* and c* values of most dyed samples showed a little change after treatment with softeners except for the color coordinates of the yellow samples, which increased. A considerable increase in the fk values for silicone softener‐treated samples was obtained. The washing fastness properties of blue samples decreased while they remained unchanged for other samples. The light fastness properties decreased for all samples after treatment with softeners.