bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrooxidation of DNA at Glassy Carbon Electrodes Modified with Multiwall Carbon Nanotubes Dispersed in Chitosan
Authors: Bollo Soledad , Ferreyra Nancy F. , Rivas Gustavo A. 
Published: March 2007

AbstractWe report on the analytical performance of glassy carbon (GCE) electrodes modified with a dispersion of multiwall carbon nanotubes (CNT) in chitosan (CHIT) for the quantification of DNA. The electroanalytical response of the resulting electrodes was evaluated using differential pulse voltammetry, while the electrochemical reactivity of the film surface was characterized using scanning electrochemical microscopy. Different treatments of the modified GCE were evaluated to improve the stability of the film and the accumulation of DNA. The guanine oxidation signal of double stranded calf‐thymus DNA after 3‐min accumulation was 20 times higher at GCE/CHIT‐CNT cross‐linked with glutaraldehyde (GTA) than at bare GCE, while the peak potential was around 45 mV less positive. The guanine oxidation signal demonstrated to be highly reproducible, with 3.4% RSD for 5 different electrodes. The treatment with sodium hydroxide demonstrated to be not effective since the resulting films were less stable and the guanine oxidation signal was ten times smaller compared to electrodes prepared with the GTA treated films. The effect of chitosan molecular weight used to prepare the dispersion and the amount of carbon nanotubes dispersed were evaluated. The response of single stranded DNA and oligo(dG)15 is also discussed.
Tailoring Zinc Oxide Nanowires for High Performance Amperometric Glucose Sensor
Authors: Zang Jianfeng , Li Chang Ming , Cui Xiaoqiang , Wang Jianxiong , Sun Xiaowei , Dong Hua , Sun Chang Q. 
Published: March 2007

AbstractZnO nanowire was tailored both physically and chemically to immobilize the enzyme glucose oxidase (GOD) for construction of a glucose sensor with high performance, which was ascribed to its high specific surface area and high isoelectric point value for efficient immobilization of high concentration of acidic enzymes and the mediating effect by the redox reaction of ZnO nanowires. The apparent Michaelis constants Jmax, and KM were adjusted in a large scope by tailoring the thickness of the GOD/ZnO nanowire layer and the enzyme load in the nanowired network. Thus, a variety of linear region, sensitivities and reaction rates of the sensor could be easily achieved. Moreover, the glucose sensor showed long term stability with the incorporation of the inorganic zinc oxide nanowire.
Simultaneous Determination of Iron, Copper, and Cadmium by Adsorptive Stripping Voltammetry in the Presence of Thymolphthalexone
Authors: Babaei Ali , Babazadeh Mitra , Shams Esmaeil 
Published: March 2007

AbstractA novel, sensitive and selective adsorptive stripping procedure for simultaneous determination of iron, copper and cadmium is presented. The method is based on the adsorptive accumulation of thymolphthalexone (TPN) complexes of these elements onto a hanging mercury drop electrode, followed by reduction of adsorbed species by voltammetric scan using differential pulse modulation. The influences of control variables on the sensitivity of the proposed method for the simultaneous determination of iron, copper and cadmium were studied using the Derringer desirability function. The optimum analytical conditions were found to be TPN concentration of 2.0 μM, pH of 9.5, and accumulation potential at −0.4 V vs. Ag/AgCl with an accumulation time of 60 s. The peak currents are proportional to the concentration of iron, copper and cadmium over the 1–80, 0.5–100 and 1–100 ng mL−1 ranges with detection limits of 0.5, 0.4 and 0.9 ng mL−1, respectively. The R.S.D. at a concentration level of 20 ng mL−1 of iron, copper and cadmium were 2.5%, 0.9% and 1.5% (n=6), respectively. The procedure was applied to the simultaneous determination of iron, copper and cadmium in the tap water and some synthetic samples with satisfactory results.
Fluvial thermal erosion: heat balance integral method
Authors: Randriamazaoro R. , Dupeyrat L. , Costard F. , Gailhardis E. Carey 
Published: March 2007

AbstractIn periglacial regions, frozen river banks are affected by thermal and mechanical erosion. In Siberia, bank retreats of up to 40 m per year are observed. This thermal erosion occurs during a few weeks, at springtime, for high enough water temperatures and river discharges. Until now, models of thermal erosion have been based on the assumption of a constant thermal erosion rate. We have developed a more general model at variable rate, whose solution is calculated using the integral method. Results of this model are compared with experiments, carried out in a cold room. A hydraulic channel allows measurements of the thermal erosion rate of a ground ice sample subjected to a turbulent water flow. Once validated, the model is applied to the periglacial river study case. The model has contributed to better understanding of the roles of each parameter during the thermal erosion process. High water temperature, discharge and ice temperature produce major thermal erosion, whereas the ice content in the soil tends to slow down the thermal erosion process. The effects of water temperature are predominant. An acceleration phase characterized by an increase of the thermal erosion rate occurs at the beginning of the thermal erosion process. The duration of such an acceleration phase is systematically studied. A relatively long acceleration phase is related to a low ablation rate. During the flood season, when the water temperature is increased to 18 °C, this acceleration phase lasts only a few minutes. However, for data typical of periglacial rivers, when the water temperature is close to the melting point, the acceleration phase can last a few days. Copyright © 2007 John Wiley & Sons, Ltd.
Role of basin‐wide landslides in the formation of extensive alluvial gemstone deposits in Sri Lanka
Authors: Gunatilaka Ana 
Published: March 2007

AbstractThe tectonically stable central highlands of Sri Lanka and its alluvial valleys are the source areas and sinks, respectively, for one of the most prolific Quaternary gemstone provinces in the world. However, the known 10Be/26Al cosmogenic‐nuclide‐determined low natural (preanthropogenic) denudation rates of 2–11 mm kyr−1, and resulting sediment fluxes, are grossly inadequate to deliver the vast throughputs of overburden required to concentrate the known gemstone deposits. Basin‐wide, unstable, slow‐moving channelized landslides and debris flows, aided by biotic factors, are the dominant mechanisms of mass‐wasting on hill‐slopes and bulk delivery of sediment to the alluvial valleys and fluvial networks. Channelization ensures modulated sediment transfer and run‐out during an erosional–depositional continuum. In a selected inventory of landslides, mobilized sediment volumes ranged from less than 1000 cubic metres to a maximum of ∼800 000 cubic metres per event. Monsoonal rainfall (both cumulative seasonal and total daily thresholds) is the primary external factor, which interacts with colluvium thickness and steep slopes in triggering landslides. There are three to five ‘threshold’ rainfall events per year in the highlands that can be expected to generate landslides. They can occur under conditions of decreasing daily rainfall as the seasonal total rainfall increases. GIS databases show a very significant spatial overlap and direct causal linkage between several hundred landslide occurrences and the innumerable gem pits and mines in the catchments of the best known mining region of Sri Lanka. Landslide‐associated mass movements, besides providing significant numbers of gemstones to the alluvial valleys over time, are also a fundamental factor in the geomorphic evolution of the rugged central highland landscape. Rainfall‐driven landslide activity may be a natural geological response affecting erosional equilibrium in high‐relief tectonically stable terrains. Climatically forced base level changes will, over time, control sediment storage, removal or reworking in the valleys. Copyright © 2007 John Wiley & Sons, Ltd.
Reducing effect of multigrounded PEN conductor on the transfer of electric potentials in low‐voltage distribution networks
Authors: Konieczny Janusz , Wróblewski Zbigniew 
Published: March 2007

AbstractThe mechanism governing the formation of the electric potential of the PEN conductor (fault voltage) in TN‐system is discussed. The occurrence of this potential is a threat to the customers, especially in rural areas, where automatic disconnection of supply can not always be executed within the time required. Considered is the phenomenon of electric potential propagation from the fault point to the whole of the network.For fault voltage calculations, a mathematical model and computer programme have been developed. Examples of calculated results are presented for various configurations of network. Multicriterion‐based simulation has enabled statistical analysis and assessments of the size of the area where fault voltage exceeds the admissible value. The computational method proposed is also applicable to the optimization of low‐voltage networks at the stage of design or modernization. Copyright © 2007 John Wiley & Sons, Ltd.
Chemical composition of the essential oil from Vernonia scorpioides (Asteraceae)
Authors: Albuquerque Maria Rose Jane R. , Lemos Telma Leda G. , Pessoa Otília Deusdênia L. , Nunes Edson P. , Nascimento Ronaldo F. , Silveira Edilberto R. 
Published: March 2007

AbstractThe essential oil from aerial parts of Vernonia scorpiodes was obtained by hydrodistillation in a Clevenger‐type apparatus. Qualitative and quantitative analysis were performed by GC–FID and GC–MS, respectively. A total of 18 compounds, representing 95.3% of the total volatile content, were identified. The major components found were β‐caryophyllene (30.6%), germacrene D (27.3%), and bicyclogermacrene (8.5%). Copyright © 2007 John Wiley & Sons, Ltd.
Chemical composition and antibacterial activity of Otanthus maritimus (L.) Hoffmanns. & Link essential oils from Corsica
Authors: Muselli Alain , Rossi Paul‐Georges , Desjobert Jean‐Marie , Bernardini Antoine‐François , Berti Liliane , Costa Jean 
Published: March 2007

AbstractThe chemical composition of Otanthus maritimus L. essential oils obtained from aerial parts, roots and whole plants from Corsica was investigated by capillary GC and GC–MS analysis. A collective oil and some of its main components were tested for antibacterial activity against microorganisms involved in nosocomial infection and food‐borne illnesses. With the exception of camphor (7.0–20.4%), the main constituents were irregular monoterpenes: yomogi alcohol (24.4–34.7%), artemisia alcohol (11.5–19.2%) and artemisyl acetate (4.9–12.6%). The antibacterial activity of O. maritimus oil and the antibacterial potential of both artemisia and yomogi alcohols against Staphylococcus aureus and Campylobacter jejuni are reported for the first time. Copyright © 2007 John Wiley & Sons, Ltd.
Characterization of volatile compounds in selected citrus fruits from Asia. Part I: freshly‐squeezed juice
Authors: Dharmawan Jorry , Kasapis Stefan , Curran Philip , Johnson Jeffrey R. 
Published: March 2007

AbstractThe volatile compounds in three selected citrus fruits from Asia, Indonesian Pontianak orange (Citrus nobilis Lour. var. microcarpa Hassk.), Indian Mosambi (Citrus sinensis Osbeck) and Philippine Dalandan (Citrus reticulata Blanco), were characterized. The volatile compounds from the headspace of the citrus juices were isolated by solid‐phase microextraction (SPME) prior to separation with gas chromatograph (GC) and identification by mass spectrometry (MS). The volatile compounds of the juices were extracted by diethyl ether for quantitative analysis, using GC–flame ionization detector (GC–FID). A total of 51 compounds were detected in Pontianak orange, 50 in Mosambi and 41 in Dalandan juice. They comprise terpenes, carbonyls, alcohols, esters and hydrocarbons, with limonene as the main compound. Each citrus cultivar studied contained compounds not frequently reported in other citrus fruits, such as β‐chamigrene in Mosambi, as well as tentatively identified 2,6‐dimethyl‐1,3,5,7‐octatetraene and isopiperitenone in Pontianak orange and in Dalandan juices, respectively. The results also showed that Mosambi and Dalandan juices portray the typical profile of sweet orange and mandarin, respectively, while Pontianak orange demonstrates its own unique traits. Copyright © 2007 John Wiley & Sons, Ltd.
HS–SPME analysis of the volatile compounds from spices as a source of flavour in ‘Campo Real’ table olive preparations
Authors: Pérez R. A. , Navarro T. , Lorenzo C. de 
Published: March 2007

AbstractThe composition of volatile compounds in seven spices was analysed by means of headspace solid‐phase microextraction (HS–SPME) from aqueous solutions of the spices, in order to devise an effective method for the analysis of volatile compounds from aqueous preparations seasoned with spices. A PDMS–DVB fibre was used for the analysis of the main volatile compounds of a saline solution of the spice. The main volatile components identified in the spices tested were: linalool in oregano; t‐anethole in fennel; methyleugenol and eucalyptol in laurel; geraniol in coriander; terpinen‐4‐ol in marjoram; eucalyptol in thyme; and cuminaldehyde in cumin. Volatile profiles depended on the botanical species of the spice. Thus, thymol was the main volatile compound of a commercial thyme (Thymus sp.), whereas in the Thymus mastichina, which is usually used in the preparation of ‘Campo Real’ table olives, the main volatile component was eucalyptol. The effects of these spices in the characteristic aroma of ‘Campo Real’ table olive preparations have been evaluated and the results suggest that HS–SPME is a useful tool for the analysis of the spices aroma compounds in aqueous preparations. Copyright © 2007 John Wiley & Sons, Ltd.
Solution of the 2‐D shallow water equations with source terms in surface elevation splitting form
Authors: Ma Dong‐Jun , Sun De‐Jun , Yin Xie‐Yuan 
Published: March 2007

AbstractA vertex‐centred finite‐volume/finite‐element method (FV/FEM) is developed for solving 2‐D shallow water equations (SWEs) with source terms written in a surface elevation splitting form, which balances the flux gradients and source terms. The method is implemented on unstructured grids and the numerical scheme is based on a second‐order MUSCL‐like upwind Godunov FV discretization for inviscid fluxes and a classical Galerkin FE discretization for the viscous gradients and source terms. The main advantages are: (1) the discretization of SWE written in surface elevation splitting form satisfies the exact conservation property (𝒞‐Property) naturally; (2) the simple centred‐type discretization can be used for the source terms; (3) the method is suitable for both steady and unsteady shallow water problems; and (4) complex topography can be handled based on unstructured grids. The accuracy of the method was verified for both steady and unsteady problems, including discontinuous cases. The results indicate that the new method is accurate, simple, and robust. Copyright © 2007 John Wiley & Sons, Ltd.
Optimal flow control for Navier–Stokes equations: drag minimization
Authors: Dedè L. 
Published: March 2007

AbstractOptimal control and shape optimization techniques have an increasing role in Fluid Dynamics problems governed by partial differential equations (PDEs). In this paper, we consider the problem of drag minimization for a body in relative motion in a fluid by controlling the velocity through the body boundary. With this aim, we handle with an optimal control approach applied to the steady incompressible Navier–Stokes equations. We use the Lagrangian functional approach and we consider the Lagrangian multiplier method for the treatment of the Dirichlet boundary conditions, which include the control function itself. Moreover, we express the drag coefficient, which is the functional to be minimized, through the variational form of the Navier–Stokes equations. In this way, we can derive, in a straightforward manner, the adjoint and sensitivity equations associated with the optimal control problem, even in the presence of Dirichlet control functions. The problem is solved numerically by an iterative optimization procedure applied to state and adjoint PDEs which we approximate by the finite element method. Copyright © 2007 John Wiley & Sons, Ltd.
Profile of psychiatric disorders and life events in medically ill elderly: experiences from geriatric clinic in Northern India
Authors: Prakash Om , Gupta L. N. , Singh V. B. , Singhal A. K. , Verma K. K. 
Published: March 2007

AbstractBackgroundMorbidity among elderly people has an important influence on their psychological well‐being. Evaluation of the morbidity profile and its determinants, which have implications for management of medical problems of elderly people, are scarce in developing countries. Even the physicians' detection rate of mental distress in elderly populations is low in medical outpatient clinics. This could be due to the large caseloads and also, importantly, underestimation of psychological concerns of the elderly. The objective of this study was to study the psychiatric co‐morbidity and life events among elderly medical outpatients.MethodsOne hundred medically ill elderly (>60 years) patients attending the Geriatric Clinic at Bikaner (North India) constituted the study population. The physical diagnosis was made by a physician based on reported illness, clinical examination and medical records. Psychiatric diagnosis was made by detailed clinical psychiatric interview using ICD‐10 guidelines. Life events were assessed by the Indian adaptation of Presumptive Stressful Life Events Scale.ResultsHypertension was the most commonly reported physical diagnosis (50%), other specific medical illnesses were osteoarthritis (15%), diabetes (13%) and constipation (8%). The study found 18% subjects had depression and 11% had other mental disorders. Patients with mental disorders had suffered more recent stressful life events. Among life events, conflicts in family (16%); unemployment of self or children (9%) was reported by elderly psychiatric patients. Other reported life events in psychiatric diagnosed elderly were conflict in family (7%), illness of self (6%) or family members (5%) and death of family members (5%) or close relatives (4%).ConclusionMental disorders are common among medically ill elderly patients, but they are poorly recognized and treated. Assessment of the psychiatric morbidity will help in strengthening psycho‐geriatric services and thus, improve the quality of life of the elderly. Copyright © 2007 John Wiley & Sons, Ltd.
FMRI activations of amygdala, cingulate cortex, and auditory cortex by infant laughing and crying
Authors: Sander Kerstin , Frome Yvonne , Scheich Henning 
Published: March 2007

AbstractOne of the functions of emotional vocalizations is the regulation of social relationships like those between adults and children. Listening to infant vocalizations is known to engage amygdala as well as anterior and posterior cingulate cortices. But, the functional relationships between these structures still need further clarification. Here, nonparental women and men listened to laughing and crying of preverbal infants and to vocalization‐derived control stimuli, while performing a pure tone detection task during low‐noise functional magnetic resonance imaging. Infant vocalizations elicited stronger activation in amygdala and anterior cingulate cortex (ACC) of women, whereas the alienated control stimuli elicited stronger activation in men. Independent of listeners' gender, auditory cortex (AC) and posterior cingulate cortex (PCC) were more strongly activated by the control stimuli than by infant laughing or crying. The gender‐dependent correlates of neural activity in amygdala and ACC may reflect neural predispositions in women for responses to preverbal infant vocalizations, whereas the gender‐independent similarity of activation patterns in PCC and AC may reflect more sensory‐based and cognitive levels of neural processing. In comparison to our previous work on adult laughing and crying, the infant vocalizations elicited manifold higher amygdala activation. Hum Brain Mapp 2007. © 2006 Wiley‐Liss, Inc.
A multivariate non‐parametric model for synthetic generation of daily streamflow
Authors: Wang Wensheng , Ding Jing 
Published: March 2007

AbstractAp‐order multivariate kernel density model based on kernel density theory has been developed for synthetic generation of multivariate variables. It belongs to a kind of data‐driven approach and is able to avoid prior assumptions as to the form of probability distribution (normal or Pearson III) and the form of dependence (linear or non‐linear). Thep‐order multivariate kernel density model is a non‐parametric method for synthesis of streamflow. The model is more flexible than conventional parametric models used in stochastic hydrology. The effectiveness and satisfactoriness of this model are illustrated through its application to the simultaneous synthetic generation of daily streamflow from Pingshan station and Yibin‐Pingshan region (Yi‐Ping region) of the Jinsha River in China. Copyright © 2007 John Wiley & Sons, Ltd.
Evapotranspiration modelling from climatic data using a neural computing technique
Authors: Kisi Ozgur 
Published: March 2007

AbstractEvapotranspiration is one of the basic components of the hydrologic cycle and essential for estimating irrigation water requirements. This paper investigates the modelling of evapotranspiration using the feed‐forward artificial neural network (ANN) technique with the Levenberg–Marquardt (LM) training algorithm. The LM algorithm has never been used in evapotranspiration estimation before. The LM is used for the optimization of network weights, since this algorithm is more powerful and faster than the conventional gradient descent. Various combinations of daily climatic data, i.e. wind speed, air temperature, relative humidity and solar radiation, from three stations in Los Angeles, USA, are used as inputs to the ANN so as to evaluate the degree of effect of each of these variables on evapotranspiration. A comparison is made between the estimates provided by the ANN and those of the following empirical models: Penman, Hargreaves, Turc. Mean square error, mean absolute error and determination coefficient statistics are used as comparing criteria for the evaluation of the models' performances. Based on the comparisons, it was found that the neural computing technique could be employed successfully in modelling evapotranspiration process from the available climatic data. The results also indicate that the Hargreaves method provides better performance than the Penman and Turc methods in estimation of the evapotranspiration. The accuracy of the ANN technique in evapotranspiration estimation using nearby station data was also investigated. Copyright © 2007 John Wiley & Sons, Ltd.
Racism in organizations: The case of a county public health department
Authors: Griffith Derek M. , Childs Erica L. , Eng Eugenia , Jeffries Vanessa 
Published: March 2007

AbstractRacism is part of the foundation of U.S. society and institutions, yet few studies in community psychology or organizational studies have examined how racism affects organizations. This paper proposes a conceptual framework of institutional racism, which describes how, in spite of professional standards and ethics, racism functions within organizations to adversely affect the quality of services, the organizational climate, and staff job satisfaction and morale. Grounded in systems theory and organizational empowerment, the framework is based on data that describe how racism was made manifest in a county public health department. The findings highlight the importance of understanding how organizations are influenced by external forces and can negatively affect clients, communities, and their own staff members. © 2007 Wiley Periodicals, Inc.