bluuebunny/crossref_metadata_2025 huggingface dataset:
The Political Economy of Human Services
Authors: Austin David M.
Published: November 2007

The political economy of the task environment of human service programmes is a major determinant of programme policy, and therefore of the nature of administrative practice. The dynamics of the political economy of particular programmes are shaped primarily by the nature of the public goods produced, rather than the private benefits to service users. Human service programmes produce one of three types of public goods: universal, redistributive, and behaviour change/social control. Each category involves distinctive programme policy and administrative issues. Changes in resource availability or in the political climate will have different consequences for each category of programme.
Local Government in Crisis: A Review Article
Authors: Bramley Glen
Published: November 2007

In this article the editor reviews six recent books dealing in different ways with the current crisis in central-local governmental relations in Britain. Three deal with the nature of local government per se, two from a critical stance alleging serious inefficiency and lack of accountability. One advocates the case for local government, and the other two examine central-local relations in particular contexts. There is strong convergence on how the present system may be described, but marked dissensus on prescriptions for reform, reflecting not only differences in political values but also an inadequate analysis of the critical organisational issues.
Misconceptions in the Current Housing Subsidy Debate
Authors: O’Sullivan A. J.
Published: November 2007

This paper examines the question of how best to define the housing subsidies received by households in various tenures. The unsettled nature of this issue is highlighted. Using current best estimates of subsidies, the paper seeks to identify the influence the housing finance system has had on the relative size of tenure sectors, and the distribution of households between these sectors. Conclusions concerning the fundamental objectives of housing policy in the U.K. are drawn from the manner in which the subsidy system appears to influence households, tenure preferences and opportunities. The importance is stressed of debating the desirability of these objectives explicitly rather than allowing them to remain obscured by continued analysis of the housing system in a fragmented fashion.
Joint Finance: An analysis of the reasons for its limited success
Authors: Green David G.
Published: November 2007

Joint Finance has produced some beneficial results but its successes have been limited due to: (a) the tight financial climate; and (b) professional and trade union resistance. To overcome the perverse financial incentives, tighter central control of funding has been advocated; and to overcome professional resistance modified training and improved teamwork have been suggested. This paper contends that these solutions are inadequate because they are based on a mistaken understanding of the source of professional power. One scheme, service credits, has been proposed which would make inroads into the problem by diminishing the extent of the state monopoly in the provision of residential care. Some weaknesses of this proposal are identified. Finally, the paper argues that professional power results, not only from state monopolies, but also from the legal privileges the professions have been granted.
Mechanochemical Additive-Assisted Reconditioning Effects and Mechanism on Worn Ferrous Surfaces
Authors: Yuansheng Jin , He Yang , Shenghua Li
Published: November 2007

An additive package of reconditioning functionality for worn ferrous surfaces has been designed in light of the mechanochemical reaction principle. The package is formulated from a fine-powdery multicomponent mixture of Serpentine minerals, surfactants, and catalysts. The main reconditioning component in the package is magnesium silicate hydroxide (Mg6(Si4O10)(OH)8), with the surfactants for dispersing the main component into bulk lubricant and the catalysts for facilitating interfacial mechanochemical reactions, particularly oil pyrolysis and carbonization. With commercial fully-formulated engine oils as benchmark, the reconditioning effects of the reconditioner package have been demonstrated in both laboratory tribotestings and in real-world heavy-duty (locomotive diesel engine) scenarios. Surface examination of sampled worn surfaces on both laboratory test specimens and cylinder bore of locomotive diesel engine has shown that a nano-crystalline layer has been generated which possesses nanometric roughness, higher surface hardness, and proper H/E ratio. Advanced analyses have indicated that the layer is composed of Fe3O4 and FeOOH nanoparticles which are dispersed on the Fe-C matrix. The smoother surface mitigates asperity interlocking which would otherwise induce high friction; the high surface hardness and appropriate H/E ratio result in less elastic deformation within nanocrystalline contact regions, which effectively lessens friction and wear arisen from plastic plowing and adhesion. Further characterization of sampled worn cylinder bore surface and analysis of used oils have suggested that generation of the nanocrystalline layer in presence of Mg6(Si4O10)(OH)8 involves three interwoven processes: oxidative mechanical polishing, lubricant carbonization and graphitization, and mechanical alloying.
Delayed Diagnosis of Kawasaki Disease: What Are the Risk Factors?
Authors: Minich L. LuAnn , Sleeper Lynn A. , Atz Andrew M. , McCrindle Brian W. , Lu Minmin , Colan Steven D. , Printz Beth F. , Klein Gloria L. , Sundel Robert P. , Takahashi Masato , Li Jennifer S. , Vetter Victoria L. , Newburger Jane W. ,   for the Pediatric Heart Network Investigators
Published: November 2007

OBJECTIVE. Because late diagnosis of Kawasaki disease increases the risk for coronary artery abnormalities, we explored the prevalence of and possible risk factors for delayed diagnosis by using the database of the Pediatric Heart Network trial of corticosteroid treatment for Kawasaki disease.

METHODS. We collected sociodemographic and clinical data at presentation for all patients who were treated for presumed Kawasaki disease at 8 centers (7 in the United States, 1 in Canada). Delayed diagnosis was evaluated by total number of illness days to diagnosis and by the percentage of patients who were treated after day 10 of illness. Independent predictors of delayed diagnosis were identified by using multivariate linear and logistic regression.

RESULTS. Of the 589 patients who received intravenous immunoglobulin, 27 were treated before screening for the trial and excluded; 562 patients formed the cohort for analysis. Kawasaki disease was diagnosed at 7.9 ± 3.9 days, 92 (16%) cases after day 10. Centers were similar with respect to patient age and gender. Centers differed in the patient percentage with incomplete Kawasaki disease; clinical criteria of cervical adenopathy, oral changes, and conjunctivitis; and distance of residence from the center. Independent predictors of greater number of illness days at diagnosis included center, age of <6 months, incomplete Kawasaki disease, and greater distance from the center. Independent predictors of diagnosis after day 10 were age of <6 months, incomplete Kawasaki disease, and greater distance). Socioeconomic variables had no association with delayed diagnosis.

CONCLUSIONS. Even after adjustment for patient factors, illness duration at diagnosis varies by center. These findings underscore the need to maintain a high index of suspicion of Kawasaki disease in the infant who is younger than 6 months and has prolonged fever even with incomplete criteria. Outreach educational programs may be useful in promoting earlier recognition and treatment of Kawasaki disease.
Hua’s theorem on sums of five prime squares in arithmetic progressions
Authors: Bauer Claus
Published: November 2007

It is proved that for a given integer
N
and for all but ⪡ (log
N
)
B
prime numbers
k
≦
N5/96 −
ε
the following is true: For any positive integers
bi
,
i
∈ {1, 2, 3, 4, 5}, (
bi
,
k
) = 1 that satisfy
N
≡
b12

+
b22

+
b32

+
b42

+
b52

(mod
k
),
N
can be written as
N
=
p12

+
p22

+
p32

+
p42

+
p52

, where the
pi
,
i
∈ {1, 2, 3, 4, 5} are prime numbers that satisfy
pi
≡
bi
(mod
k
).
Estimating Yellow Starthistle (Centaurea solstitialis) Leaf Area Index and Aboveground Biomass with the Use of Hyperspectral Data
Authors: Ge Shaokui , Xu Ming , Anderson Gerald L. , Carruthers Raymond I.
Published: November 2007

Hyperspectral remote-sensed data were obtained via a Compact Airborne Spectrographic Imager-II (CASI-II) and used to estimate leaf-area index (LAI) and aboveground biomass of a highly invasive weed species, yellow starthistle (YST). In parallel, 34 ground-based field plots were used to measure aboveground biomass and LAI to develop and validate hyperspectral-based models for estimating these measures remotely. Derivatives of individual hyperspectral bands improved the correlations between imaged data and actual on-site measurements. Six derivative-based normalized difference vegetation indices (DNDVI) were developed; three of them were superior to the commonly used normalized difference vegetation index (NDVI) in estimating aboveground biomass of YST, but did not improve estimates of LAI. The locally integrated derivatives-based vegetation indices (LDVI) from adjacent bands within three different spectral regions (the blue, red, and green reflectance ranges) were used to enhance absorption characteristics. Three LDVIs outperformed NDVI in estimating LAI, but not biomass. Multiple regression models were developed to improve the estimation of LAI and aboveground biomass of YST, and explained 75% and 53% of the variance in biomass and LAI, respectively, based on validation assessments with actual ground measurements.
Glyphosate Susceptibility in Common Lambsquarters (Chenopodium album) is Influenced by Parental Exposure
Authors: Kniss Andrew R. , Miller Stephen D. , Westra Philip H. , Wilson Robert G.
Published: November 2007

Field studies were carried out at two sites in 2005 using common lambsquarters seed collected from long-term research plots near Scottsbluff, NE; Fort Collins, CO; and Torrington, WY, to determine the effect of herbicide selection pressure on glyphosate susceptibility. Parental herbicide exposure influenced the level of glyphosate susceptibility exhibited by a subsequent generation. Common lambsquarters selected from historical plots receiving continuous and exclusive use of glyphosate exhibited lower mortality in response to 420 g ae ha−1glyphosate compared with selections from nonglyphosate treatment histories. Selections from rotating glyphosate treatment histories demonstrated an intermediate tolerance response. Differences in response were also influenced by environmental conditions.
Identification of Japanese Foxtail (Alopecurus Japonicus) Resistant to Haloxyfop Using Three Different Assay Techniques
Authors: Yang Caihong , Dong Liyao , Li Jun , Moss Stephen R.
Published: November 2007

The objective of this study was to investigate the resistance level of Japanese foxtail to haloxyfop, an acetyl coenzyme A carboxylase (ACCase; EC 6.4.1.2)–inhibiting herbicide. Eleven biotypes were collected from oilseed rape fields in different areas in Jiangsu and Anhui provinces where haloxyfop had been continuously applied for various periods. Biotypes were assessed by two different methods, a seed bioassay and whole-plant assay, to identify the most resistant and susceptible biotypes for further studies on the activity of the target enzyme ACCase. A good correlation was obtained between the two different bioassay methods. The Jurong and Chuzhou biotypes were the most resistant and susceptible biotypes, respectively, whereas the other nine biotypes showed variable and relatively low degrees of haloxyfop resistance. Furthermore, target-site enzyme sensitivity results confirmed that the Jurong biotype was resistant to haloxyfop with a concentration of herbicide causing 50% inhibition of ACCase activity (IC50) of 9.19 µM, whereas the IC50 of the susceptible biotype (Chuzhou) was 0.76 µM, giving a resistance index of 12.
Purple Deadnettle (Lamium purpureum) and Soybean Cyst Nematode Response to Cold Temperature Regimes
Authors: Creech J. Earl , Santini Judith B. , Conley Shawn P. , Westphal Andreas , Johnson William G.
Published: November 2007

An experiment was conducted in growth chambers to determine the influence of cold temperature regimes, designed to simulate winter temperature conditions and spring recovery, on the interaction between purple deadnettle and soybean cyst nematode (SCN). The study was a factorial arrangement of treatments with five levels of temperature (20, 15, 10, 5, or 0 C), two levels of exposure time to the temperature (10 or 20 d), and two levels of recovery time at 20 C following exposure (0 or 20 d). In general, purple deadnettle shoot and root growth increased with temperature and time. The ability of purple deadnettle to recover from cold temperatures declined as the length of time that the plant was subjected to the cold temperature increased. SCN juveniles per gram of root at the conclusion of the temperature treatment declined as the temperature increased from 0 to 15 C, likely a result of continued purple deadnettle root growth and the inhibition of SCN hatch, growth, or development at those temperatures. SCN female, cyst, and egg production per gram of root generally increased with temperature and occurred under all temperature regimes. The results of this research indicate that, after hatching, SCN juveniles can survive a period of cold temperature inside the roots of a winter annual and continue development when transferred to warmer temperatures. Therefore, in a field environment, where fall or spring alone may not be sufficient for SCN to complete a reproductive cycle on a winter annual weed, the nematode may be able to reproduce by combining the fall and spring developmental periods.
Evaluation of the Australian Branched Broomrape (Orobanche ramosa) Eradication Program
Authors: Panetta F. Dane , Lawes Roger
Published: November 2007

Because weed eradication programs commonly take 10 or more years to complete, there is a need to evaluate progress toward the eradication objective. We present a simple model, based on information that is readily obtainable, that assesses conformity to the delimitation and extirpation criteria for eradication. It is applied to the program currently targeting the annual parasitic weed, branched broomrape, in South Australia. The model consists of delimitation and extirpation (E) measures plotted against each other to form an ‘eradograph.’ Deviations from the ‘ideal’ eradograph plot can inform tactical responses, e.g., increases in survey and/or control effort. Infestations progress from the active phase to the monitoring phase when no plants have been detected for at least 12 mo. They revert to the active phase upon further detection of plants. We summarize this process for the invasion as a whole in a state-and-transition model. Using this model we demonstrate that the invasion is unlikely to be delimited unless the amount of newly detected infested area decreases, on average, by at least 50% per annum. As a result of control activities implemented, on average approximately 70% (range, 44 to 86%) of active infestations progressed to the monitoring phase in the year following their detection. Simulations suggest that increasing this rate of transition will not increaseEto a significant extent. The rate of reversion of infestations from the monitoring phase to the active phase decreased logarithmically with time since last detection, but it is likely that lower rates of reversion would accelerate the trend toward extirpation. Program performance with respect to the delimitation criterion has been variable; performance with respect to the extirpation criterion would be improved considerably by the development and application of cost-effective methods for eliminating branched broomrape soil seed populations.
Seismic response of wrap-faced reinforced soil-retaining wall models using shaking table tests
Authors: Murali Krishna A. , Madhavi Latha G.
Published: November 2007

This paper presents the results of shaking table tests on geotextile-reinforced wrap-faced soil-retaining walls. Construction of model retaining walls in a laminar box mounted on a shaking table, instrumentation, and results from the shaking table tests are discussed in detail. The base motion parameters, surcharge pressure and number of reinforcing layers are varied in different model tests. It is observed from these tests that the response of the wrap-faced soil-retaining walls is significantly affected by the base acceleration levels, frequency of shaking, quantity of reinforcement and magnitude of surcharge pressure on the crest. The effects of these different parameters on acceleration response at different elevations of the retaining wall, horizontal soil pressures and face deformations are also presented. The results obtained from this study are helpful in understanding the relative performance of reinforced soil-retaining walls under different test conditions used in the experiments.
Bridging boundaries: scientists, creative writers, and the long view of the forest
Authors: Swanson Frederick J , Goodrich Charles , Moore Kathleen Dean
Published: November 2007

The Long‐Term Ecological Reflections program brings together ecologists, creative writers, and philosophers at sites of long‐term ecological research to advance understanding of ecological change and of our evolving relationship with the natural world. Developed as an analog to the Long‐Term Ecological Research (LTER) program sponsored by the National Science Foundation, the Reflections program attempts to bridge the sciences and humanities in places like the HJ Andrews Experimental Forest LTER site (Oregon) and Mount St Helens (Washington State), where participants reflect, share ideas, and write. Records of these reflections are posted as primary, raw data (eg journal entries and video interviews) on a webpage, and completed works are published in widely circulated journals. This growing body of material demonstrates the importance of taking the long view in building ecological knowledge. The writings display the value of metaphor and story in communicating such knowledge to the public.
Microarray expression technology in clinical research of non-Hodgkin lymphoma
Authors: Baltic Vladimir , Baltic Milan
Published: November 2007

Nowadays, in genomocentric era accelerated research of the human genome coupled with advances is enabling the comprehensive molecular profiling of human tissue. Particularly, DNA microarrays are powerful tools for obtaining global view of human non-Hodgkin lymphomas gene expression. Complex information from lymphomas "expression profiling" studies can, in turn, be used to create molecular markers that have diagnostic or prognostic implications. The gene "expression profiling" is not of routine clinical oncology practice, but is used in genomic classification of clinically relevant subgroups of non-Hodgkin lymphoma. The genomics biomarkers have been incorporated into current prognostic models which are based on IPI, R-IPI, and FLIPI. Molecular or pharmacogenomic profiling can be used as new therapeutic targets for patients who are refractory to current therapy. We discus the utility of DNA microarray-based lymphoma profiling in clinical oncology research, and identify future of research in lymphoma evolving fields.
Giant post-traumatic cyst after closed degloving injury
Authors: Jovanovic Mladen , Janjic Zlata , Vuckovic Nada
Published: November 2007

Post-traumatic cysts of soft tissue usually occur at the junction of the subcutaneous fat and deep fascia, most often filled with serosanguinous fluid and lined with fibrous tissue. It appears as complication after closed degloving injuries when crushing and shearing forces cause separation of the skin and subcutaneous fat from the deep fascia and muscle, creating a cavity filled with hematoma and liquefied fat. This rare condition calls Morel-Lavallee lesion, which was first described by this French physician in 1853. Unrecognized injuries will evolve in cystic formation filled with serous fluid. Predestined regions of body for this kind of trauma are trochanteric, proximal thigh and ischiolumbal, most often associated with a pelvic girdle fracture. Long-standing Morel-Lavallee lesion may either remain stable or occasionally expand and can induce chronic pain. Sometimes, it is hard clinically to distinguish chronic cyst from cystic-tumor formation. Magnetic resonance imaging is the modality of choice for detection and revealing the exact size and location of these lesions. The best method of treatment is surgical excision with complete resection.
On space and time in quantum cosmology
Authors: Nesic Ljubisa , Obradovic Stojan
Published: November 2007

The paper considers the properties of space and time in quantum cosmology. It presented the basic ideas of the substantial and relational conceptions of space and time, as well the basic ideas of the continuity and discreteness of space and time. The basics of standard quantum cosmology, i.e. quantum cosmology formulated over the field of real numbers R, have also been presented. Quantum cosmology is the application of the quantum theory to the universe as a whole in the early phases of its evolution, when the universe was very small so that all the four interactions were practically unified. In order to obtain the maximum possible information from quantum cosmology it is necessary that it be "complete". The concept "complete" refers here to the formulation of the theory over the field of real numbers and the field of p-adic numbers Qp. Since p-adic numbers are generally not well-known, the idea of their introduction has carefully been considered. Within the p-adic quantum cosmology representing quantum cosmology over the field of p-adic numbers Qp, the main results concerning the de Sitter model have been presented. The consequence of this (complete) formulation of the de Sitter model is the radius discreteness of the universe.
Effects of γ-irradiation on electrical characteristics of power vdmos transistors
Authors: Pavlovic Z. , Manic Ivica , Golubovic Snezana
Published: November 2007

In this paper we present the results of both experimental investigation and analytical modelling of ?-irradiation effects on basic electrical characteristics of power VDMOS transistors. First, an analytical model that yields the drain current and transconductance dependencies on gate oxide charge density is developed. The experimental data are utilized to establish an analytical relation between the absorbed dose of ?-irradiation and corresponding effective density of gate oxide charges, as well as to extract the values of model parameters. Drain current and transconductance of VDMOS devices are then modelled as the functions of irradiation dose. Finally, the results of modelling are compared with experimental data.
Fundamental and second harmonic amplitudes in a collisional magnetoactive plasma
Authors: Jovanovic B.M. , Zivkovic Branimir
Published: November 2007

We present a theoretical investigation of frequency doubling of electromagnetic wave in homogeneous, collisional and magnetized plasma. The coupled nonlinear equations for fundamental ordinary wave and second harmonic extraordinary wave have been solved. The amplitudes of these waves have been calculated for various values of collisional frequency and distance from the plasma boundary.
The effects of dietary nitrate, pH and temperature on nitrate reduction in the human oral cavity
Authors: Bojic Danijela , Bojic Aleksandar , Perovic Jelica
Published: November 2007

Dietary nitrate is metabolized to nitrite by bacterial flora on the posterior surface of the tongue leading to increased salivary nitrite concentrations. In the acidic environment in the stomach, nitrite forms nitrous acid, a potent nitro sating agent. The aim of this study was to examine the effects of dietary nitrate, pH and temperature on nitrate reduction in the human oral cavity. Nitrate reduction was monitored by nitrate reduction assay based on incubation of nitrate test solutions in the mouth. Results show that all investigated factors significantly influence the reduction of nitrate in the oral cavity. With increasing levels of nitrate the amounts of nitrite in reduction assay increased, but reduction ratio (NO2/NO3) decreased in this conditions. Influence of pH on nitrate reduction is specific and in line with nature of nitrite-producing bacteria. The greatest reduction activity of bacteria is at pH 8. Variations of temperature of the oral cavity due to outdoor conditions also influence its reduction activity which is twice lower in January than in July. .
Colour parameters, whiteness indices and physical features of marking paints for horizontal signalization
Authors: Zarubica Aleksandra , Miljkovic Milena , Purenovic Milovan , Tomic Vesna
Published: November 2007

The present paper describes the assessment of colour parameters of industrial paints for horizontal signalization (designed as POM S1 and POM S2 / ZEB 1 and ZEB 2) of white colour hue, coming from two different producers ("Pomoravlje" and "Zorka") with reference to an independent sample (IND 0) and some physical properties of each sample. Colorimetric characterization of samples was performed using a reflectance spectrophotometer "Update Colour Eye 3000". Standard and modified test methods (ASTM) were performed to establish physical properties of the paints. The industrial paints show better values for the investigated parameters and properties and satisfy standards prescribed by law. POM S2 sample with dry film thickness, similar to the same of other samples, provides the best physical features maximizing quality and minimizing protection cost.
Global warming and greenhouse gases
Authors: Belic Dragoljub
Published: November 2007

Global warming or Climate change refers to long-term fluctuations in temperature, precipitation, wind, and other elements of the Earth's climate system. Natural processes such as solar-irradiance variations, variations in the Earth's orbital parameters, and volcanic activity can produce variations in climate. The climate system can also be influenced by changes in the concentration of various gases in the atmosphere, which affect the Earth's absorption of radiation.
Indoor radon measurements by nuclear track detectors: Applications in secondary schools
Authors: Banjanac R. , Dragic A. , Grabez B. , Jokovic D. , Markushev D. , Panic B. , Udovicic V. , Anicin I.
Published: November 2007

Indoor radon measurements by nuclear track detectors and application of the method in secondary schools in Serbia were performed in the spring 2004. Thirty detectors (type CR-39) were distributed to high school teachers in several cities in Serbia. After three months of the detectors exposure, they were sent back to the Low- Level Laboratory, Institute of Physics, Belgrade. After exposure, the CR-39 detectors were etched in a 6N NaOH at 700C for 3 hours. The tracks were counted by the semiautomatic track-counting system. The preliminary results are presented in this paper.
Ecophysics and education
Authors: Nesic Ljubisa , Raos Miomir
Published: November 2007

Environmental problems arise from an interaction of man with nature Environmental physics uses a number of sub-disciplines of physics in order to solve this problem. This in turn necessitates the study of various aspects of the man-environment interaction through educational programs. In this paper we discuss the motives for teaching environmental physics and present some ideas of how to improve the position of this subject in the educational system in Serbia. The role of specific seminars in this field is emphasized.
Solar energy and sustainable development
Authors: Pavlovic T.M. , Radosavljevic J.M. , Pavlovic Z.T. , Kostic Lj.T.
Published: November 2007

In this paper attention is drawn to the energy consumption in the world solar energy, sustainable development, agenda 21 and the influence of the renewable energy sources and solar energy on the sustainable development.
Producing biodiesel from yellow greases with high free fatty acids
Authors: Amrani Mahacine
Published: November 2007

Biodiesel is a diesel replacement fuel that is manufactured from vegetable oils recycled cooking greases and oils or animal fats. Biodiesel offers many advantages because it is renewable, nontoxic, biodegradable, and suitable for sensitive environments. It can also be used in most diesel equipments with no or only minor modifications. These yellow greases contain great quantities of free fatty acids which form soaps in the presence of alkaline catalyst. Pretreatments of the raw material with acid catalysts are necessary to avoid the soap formation. The transesterification of yellow greases is supplemented in the presence of an alkaline catalyst. The greatest production of biodiesel corresponds to molar flows of 4.985 kmol.hr-1 of methyl oleate, and 4.658 kmol.hr-1 of methyl butyrate.
Synthesis and characterization of heterocyclic substituted fluoran compounds
Authors: Patel Sachin , Patel Manish , Patel Ranjan
Published: November 2007

New quinazolinone-substituted fluoran compounds were synthesized by reaction of keto acid, 2?-carboxy-2-hydroxy-4-N-pyrrolidinylbenzophenone with different quinazolinone derivatives in the presence of conc. sulphuric acid. All the synthesized fluoran compounds were characterized by spectroscopic methods (IR, 1H-NMR and UV-visible spectroscopy) and elemental analysis. The fluoran compounds are colorless or nearly colorless and develop color on contact with electron-accepting compounds.
Linear sweep polarographic determination of nucleic acids using acridine orange as a bioprobe
Authors: Sun Wei , Zhao Na , Yuan Xianlong , Jiao Kui
Published: November 2007

The interaction of acridine orange (AO) with double-stranded (ds) DNA in aqueous solution was investigated by linear sweep polarography (LSP) on a dropping mercury working electrode (DME). In pH 2.5 Britton-Robinson (B-R) buffer solution, AO had a sensitive linear sweep polarographic reductive peak at -0.89 V (vs. SCE), which could be greatly inhibited by the addition of dsDNA, with a positive shift of the peak potential. Based on the decrease of the reductive peak current, a new quantitative electrochemical determination method for dsDNA was developed with a linear range of 2.0?20.0 mg l-1 and the linear regression equation: ?Ip" (nA) = 111.90 C (mg l-1)+125.32 (n = 9, ? = 0.997). The influences of commonly co-existing substances, such as metal ions, amino acid, etc., on the determination were also investigated. The method is sensitive, rapid and simple with good selectivity. The new proposed method was further applied to the detection of RNA and three synthetic samples containing dsDNA with satisfactory results. The binding number and the equilibrium constant between dsDNA and AO were calculated by an electrochemical method.
Kinetic study of methanol oxidation on Pt2Ru3/C catalyst in the alkaline media
Authors: Tripkovic A.V. , Popovic K.Dj. , Lovic J.D.
Published: November 2007

The electrochemical oxidation of methanol in NaOH solution was examined on a thin film Pt2Ru3/C electrode. The XRD pattern revealed that the Pt2Ru3 alloy consisted of a solid solution of Ru in Pt and a small amount of Ru or a solid solution of Pt in Ru. It was shown that in alkaline solution, the difference in activity between Pt/C and Pt2Ru3/C is significantly smaller than in acid solution. It is proposed that the reaction follows a quasi bifunctional mechanism. The kinetic parameters indicated that the chemical reaction between adsorbed COad and OHad species could be the rate limiting step.
Wall-to-liquid mass transfer in fluidized beds and vertical transport of inert particles
Authors: Boskovic-Vragolovic Nevenka , Garic-Grulovic Radmila , Grbavcic Zeljko
Published: November 2007

Mass transfer coefficients in single phase flow, liquid fluidized beds and vertical hydraulic transport of spherical inert particles were studied experimentally using 40 mm and 25.4 mm diameter columns. The mass transfer data were obtained by studying the transfer of benzoic acid from a tube segment to water using the dissolution method. In all runs, the mass transfer rates were determined in the presence of spherical glass particles 1.2, 1.94 and 2.98 mm in diameter. The influence of different parameters, such as liquid velocity, particles size and voids on mass transfer in fluidized beds and hydraulic transport are presented. The data for mass transfer in all the investigated systems are shown using the Sherwood number (Sh) and mass transfer factor - Colburn factor (jD) - as a function of Reynolds number (Re) for the particles and for the column. The data for mass transfer in particulate fluidized beds and for vertical hydraulic transport of spherical particles were correlated by treating the flowing fluid-particle mixture as a pseudo fluid by introducing a modified mixture Reynolds number (Rem). A new correlation for the mass transfer factor in fluidized beds and in vertical hydraulic transport is proposed.
Comparison of the swelling kinetics of a partially neutralized poly(acrylic acid) hydrogel in distilled water and physiological solution
Authors: Kostic Aleksandar , Adnadjevic Borivoj , Popovic Aleksandar , Jovanovic Jelena
Published: November 2007

The isothermal kinetics curves of the swelling of a poly(acrylic acid) hydrogel in distilled water and physiological solution at temperatures ranging from 20 to 40 ?C were determined. The possibility of applying both the Fick?s kinetics model and kinetics model of the first order chemical reaction to the swelling kinetics of the PAA hydrogel in distilled water and physiological solution were examined. It was found that the possibilities of applying these models were limited. The new model of the kinetics of swelling in distilled water and physiological solution was established. The kinetic parameters (Ea, ln A) for the swelling in distilled water and physiological solution were determined. The decrease of the equilibrium degree of swelling and the saturation swelling rate of the swelling of the PAA hydrogel in physiological solution compared to swelling in distilled water could be explained by the decreased differences in the ionic osmotic pressures between the hydrogel and the swelling medium. The increase of the initial swelling rate in the physiological solution might be caused by an increased density of charges at the network and by an increased affinity of the network towards the water molecules. The increase of the activation energy of the swelling of the PAA hydrogel in the physiological solution is a consequence of its additional "ionic crosslinking".
The frequency of pathological ultrasonographic findings of the gallbladder in patients with infectious diseases
Authors: Dokic Ljubisa , Delic Dragan , Dulovic Olga , Korac Milos , Milosevic Branko , Lavadinovic Lidija
Published: November 2007

Introduction The objective of our study was to establish, through retrospective analysis of sonographic findings obtained by portable ultrasound devices, the frequency of pathological findings of the gallbladder and common bile duct in a randomized group of patients with infectious diseases. Material and methods During five years (January 1, 2000 - December 31, 2004), gallbladder and common bile duct were examined by ultrasonography in 2691 adult patients (1440 males and 1251 females), mean age 48?17 years, ranging from 17 to 92 years at the Institute of Infectious and Tropical Diseases in Belgrade. The examination included the measurement of size and shape of the gallbladder, its wall and lumen, as well as measurement of caliber and content of the common bile duct. Conventional portable ultrasound devices, ALOKA SSD-500 and SSD-1000 (B-mod) with convex 3.5 and 5 MHz probes were used. Results The cholecyst was normal in size (<120x50 mm) in 2164 (80.4%), and enlarged in 65 (2.4%) patients. The gallbladder was surgically removed in 163 (6.1%) patients, it was pseudoseptal in 141 (5.2%) and invisible in 44 (1.6%) patients. The gallbladder wall was normal in 2031 (75.5%), thickened in 259 (9.6%) and edematous in 173 (6.4%). Gallbladder calculosis was present in 310 (11.5%), and choledocholithiasis in 13 (0.5%) patients. Conclusion Development of morphological abnormalities of the gallbladder and common bile duct was frequent in non-selected patients with infectious diseases. The majority of them may be detected by portable ultrasound devices, which makes them rather applicable for large clinical-epidemiological studies.
Etiological aspects of anterior open bite
Authors: Stojanovic Ljiljana
Published: November 2007

Introduction. Open bite is a multifactorial phenomenon and no single factor can account for open-bite. Etiology plays an important role in diagnosis. Heredity, unfavorable growth patterns, incorrect jaw postoure, are the characteristics of skeletal open bite. Digit sucking. Depending on where the thumb is placed, a number of different types of dental problems can develop. Malocclusions of the late mixed or permanent dentitions, caused by thumb sucking are not self corrected and orthodontic treatment is necessary for their correction. Lymphatic tissue. In order to produce oral respiration, the mandible is postured inferiorly with the tongue protruded and resting against the oral floor. This postural alteration induces dental and skeletal modifications similar to those caused by thumb sucking. This may cause excessive eruption of the posterior teeth, leading to an increase in the vertical dimension of the face and result in development of anterior open bite. Tongue thrust. Tongue habits cause an anterior open bite or they develop secondarily to thumb sucking. In skeletal open bite the tongue habit acts as a secondary factor which helps to maintain or exacerbate the condition. Many orthodontists have had a discouraging experience of completing dental treatment, with what appeared to be good results, only to discover that the case had relapsed because the patient had a tongue thrust swallowing pattern. Conclusion. Dentoalveolar or habitual open bite is caused by habits, which influence the growth and development of dentoalveolar processes and contribute to occlusal disharmonies. Prior to eruption of adult dentition, open bite related to oral habits is usually not a concern as when the habits stop, because the erupting dentition tends to improve spontaneously. Treatment is usually not necessary until permanent teeth erupt (~6 years old). .
Duplex doppler sonography in portal hypertension
Authors: Niciforovic Dijana , Till Viktor , Hadnadjev Dusan , Govorcin Mira , Lucic Zorka , Lovrenski Jovan
Published: November 2007

Conventional echotomography and duplex Doppler ultrasonography are noninvasive imaging techniques in measurement of hepatic blood flow. In the period from February 2002 to March 2004, 29.086 patients underwent ultrasound examination at the Institute of Radiology in Novi Sad, and 17.503 presented with symptoms of gastroenterology diseases and/or hepatobiliary tract diseases. 984 patients underwent duplex Doppler sonography. This prospective study included 50 patients with suspected or confirmed diagnosis of portal hypertension. All patients were examined using Siemens Versa Pro (3.5 MHz convex probe; B-mode, color and pulse Doppler). The following parameters were evaluated: Doppler sonoscore, congestion index and portal vein thrombosis. By analyzing gathered data, the diagnosis of portal hypertension was confirmed in 10% of patients at baseline, and in 6% of patients at last follow-up, six months later. Results of this investigation demonstrate the importance of duplex Doppler ultrasonography as an excellent noninvasive diagnostic method used for visualization of the direction and velocity of blood flow, as well as presence of portal vein thrombosis. This imaging modality is used as an initial diagnostic tool in the evaluation of the portohepatic circulation, especially in portal hypertension syndrome and in suspected portal vein thrombosis. .
The effects of air pollution on the frequency of respiratory symptoms in the population of Nis and Niska Banja
Authors: Stankovic Aleksandra , Nikic Dragana , Nikolic Maja
Published: November 2007

Introduction. Ambient air pollution, particularly in densely populated urban areas, is a major risk factor for the health of the exposed population. The respiratory tract is the primary target for air pollutants. The aim of this study was to evaluate the effects of long-term exposure to air pollution and incidence of respiratory symptoms and diseases. Material and methods. Measurements of air pollutants: sulphur dioxide and soot particles, were carried out daily at the Institute of Public Health in Nis at two locations, in Nis and in Niska Banja, during the period 1999-2003. The Air Quality Index was calculated for both areas. The investigation included 654 women, nonsmokers, between 20-30 years of age, from two areas with different levels of common air pollutants. The prevalence of respiratory symptoms and diseases was determined on the basis of a modified WHO standard questionnaire completed by doctors. Results. The obtained results show that examinees from Nis had a statistically higher prevalence of some respiratory symptoms (cough with cold and phlegm) whereas women from Niska Banja had a statistically significantly higher prevalence of lower respiratory tract diseases. Conclusion. Long-term exposure to low concentrations of air pollutants is a contributing factor to the development of respiratory symptoms and diseases.
Assessment of endometrial receptivity by Color Doppler and ultrasound imaging
Authors: Lilic Vekoslav , Tubic-Pavlovic Aleksandra , Radovic-Janosevic Dragana , Petric Aleksandra , Stefanovic Milan , Zivadinovic Radomir
Published: November 2007

Introduction: Color Doppler sonography is a new method used to investigate changes during the menstrual cycle in infertile women. The objective of this study was to investigate the correlation of uterine and endomterial-subendomterial blood flow in infertile women using ultrasound and color Doppler sonography. Material and methods: A prospective clinical study included 65 infertile women divided into three groups. Transvaginal ultrasound examination was performed on days XI, XIV and XX. All results were statistically analyzed. We investigated the correlation between cycles, pregnancy outcome and distribution of endomterial-subendomterial blood flow, as well as uterine arterial blood flow. Results and conclusion: Endomterial-subendometerial blood flow distribution pattern assessed by transvaginal color Doppler, as well as good flow in uterine vessels, are necessery for good pregnancy rates. Thin endomterium, undetectable subendomterial blood flow and higher uterine arterial resistance, were associated with low pregnancy rate and poor outcome.
Depression as the cause and consequence of cerebrovascular diseases
Authors: Rabi-Zikic Tamara , Zarkov Marija , Nedic Aleksandra , Slankamenac Petar , Zivanovic Zeljko , Dobrenov Dragica
Published: November 2007

Inbtroduction: Recent epidemiological, clinical, neuroimaging and neuropathological studies have reported substantial evidence on the complex interactive relationships between depression and cerebrovascular diseases, especially in older populations, and plausible explanations of the etiopathogenetic mechanisms in both directions have been proposed. Poststroke depression Although there is no general consensus regarding its prevalence, it is widely accepted that major depression after stroke is common and that it should be recognized as a key factor in rehabilitation and outcome following stroke. Vascular depression The "vascular depression" hypothesis presupposes that late-onset depression may often result from vascular damage to frontal-subcortical circuits implicated in mood regulation. This concept has stimulated many researches and the obtained results support the proposed hypothesis. Depression as a stroke risk factor Recent large studies have emphasized the role of depression per se in the development of subsequent stroke. Mechanisms proposed to explain the increased risk of cerebrovascular diseases in depressed patients There are a number of plausible mechanisms that could explain why depression may increase the risk of subsequent cerebrovascular disease, the most important being sympathoadrenal hyperactivity, platelet activation, an increase in inflammatory cytokines and an increased risk of arrhythmias. Conclusion: Thorough clinical examinations determining the conventional stroke risk factors in the population with depression, as well as management of depression as part of the overall measures for the reduction of cerebrovascular risk factors are of utmost importance.
The role of current audiological tests in the early diagnosis of hearing impairment in children
Authors: Lemajic-Komazec Slobodanka , Komazec Zoran , Vlaski Ljiljana
Published: November 2007

Introduction: Permanent hearing impairment is a significant and relatively common condition in newborns, affecting at least 1 child per 1000 live births. The early identification of hearing loss is very important in order to begin early rehabilitation and for optimizing normal development of language. Material and methods: We examined 70 children with parental suspicion of a hearing loss. Brainstem Evoked Response Audiometry was performed and the group was divided into three subgroups. The following parameters were analyzed: the average age of hearing loss-identification, the time of parental first suspicion of a hearing loss, as well as risk factors for hearing impairment. Results and discussion: Of 70 children with parental suspicion of a hearing loss, in 17 cases normal hearing or mild hearing loss (up to 40 dB HL) was found (group I), 16 children were suffering from moderate and severe hearing loss (40 to 90 dB HL) (group II), and 37% of children were suffering from profound hearing loss (greater than 90 dB HL) (group III). Up to the age of 2, the diagnosis was made in 17.64% of children in group I, in 25% in group II, and in 58.8% in group III. The average age of hearing loss identification was 2.83, 3.32, 2.32 years in groups I, II, III, respectively, although parents suspected hearing problems at least one year earlier. Presence of hearing impaired family members as well as of risk factors were not sufficient reasons to get a medical check-up. Conclusion: The use of otoacoustic emission testing in routine clinical practice, as well as education of parents and pediatricians, was followed by earlier detection of hearing loss in regard to our previous study (10 years ago). The mean age of diagnosis in our region is still over 2 years, but establishment of a universal screening program may help reduce the age of hearing loss detection.