bluuebunny/crossref_metadata_2025 huggingface dataset:
Trickle bed reactor operation under forced liquid feed rate modulation
Authors: Hanika Jiří , Jiricný Vladimir , Karnetova Petra , Kolena Jiři , Lederer Jaromír , Skala Dávid , Stanĕk Vladimir , Tukac Vratislav
Published: March 2009

Paper deals with study of behavior of trickle-bed reactor under periodic feed rate modulation conditions. Unsaturated hydrocarbons hydrogenation (typical for pyrolysis gasoline hydrotreatment) was investigated. As model reactions hydrogenation of cyclohexene and styrene on egg-shell type palladium catalyst was studied. Numerical solution of theoretical model predicting strong effect of period split on a reactor performance is discussed. Periodic operation can enhance trickle-bed productivity due to decrease of flowing liquid film thickness and by increase of mean reactor temperature. Brief data about experimental pilot plant unit for investigation of dynamic operation of trickle bed reactor are presented.
The influence of the operation conditions and the extraction techniques on the yield, kinetics and the composition of ethanol extracts of Hieracium pilosella L.
Authors: Stanojevic Ljiljana , Stankovic Mihajlo , Nikolic Ljubisa , Nikolic Vesna
Published: March 2009

The optimal operational extraction conditions (50 % v/v ethanol, solvomodule l:15 m/v, temperature: the solvent boiling temperature) were determined by investigating the influence of the ethanol concentration (30 - 95 % v/v), solvomodule (1:10 - 1:25 m/v) and the temperature of the maceration extraction on the yield and kinetics of total extraction matter, chlorogenic acid, umbelliferone and apigenin-7-O-glucoside from Hieracium pilosella L. Based on the results of Soxhlet and Tillepape extraction kinetics, the investigations of the total extraction matter and the components under the optimal maceration operation conditions it was found that the highest yield of the extraction matter from the dry plant material (43.0 g/100 g of the dry plant material, i.e. 97.7% of the extractive matter content in the plant material), chlorogenic acid (20.30 g/100 g of dry plant material, i.e. 94 % of the chlorogenic acid content in the plant material), umbelliferone (0.30 g/100 g of the dry plant material, i.e. 96.7% of umbelliferone content in the plant material, and apigenin-7-O-glucoside (0.24 g/100 g of the dry plant material, i.e. 96 % of the apigenin-7-O-glucoside content in the plant material) was obtained by using a Soxhlet extraction method. The contents of chlorogenic acid, umbelliferone and apigenin-7-O-glucoside in the extracts were determined by HPLC method. Chlorogenic acid is the component with the highest share in all the extracts. (It was found) The high content of chlorogenic acid in the investigated plant material (21.60 %) and the high level of its extraction from the plant material (75-94**%) were found under the defined optimal maceration conditions, Soxhlet and Tillepape extraction.
Preparation and characterization of penicillin acylase immobilized on sepabeads EC-EP carrier
Authors: Zuza Milena , Siler-Marinkovic Slavica , Knezevic Zorica
Published: March 2009

This paper reports the covalent immobilization of penicillin G acylase from E. coli on Sepabeads EC-EP, an epoxy-activated polymethacrylic carrier, and describes the properties of the immobilized enzyme. Due to its versatility to mediate hydrolysis of penicillins and semi-synthetic B-lactam antibiotics synthesis reactions, the selected enzyme belongs to a class of biocatalysts of great industrial interest. The immobilized enzyme was characterized in its pH and thermal stability and reaction kinetics. The immobilization of penicillin acylase resulted in a slightly different pH activity profile and temperature optima, indicating that the immobilization by this method imparted the structural and conformational stability to this enzyme. The immobilized enzyme also retained a high catalytic activity and showed the increased thermal stability compared with a free enzyme. By comparison of decimal reduction time values obtained at 50?C, it can be concluded that the immobilized enzyme was approximately 5-fold more stable than a free enzyme. The immobilization procedure developed is quite simple and easily reproduced, and provides a promising solution for the application of penicillin acylase for the purpose of 6-aminopenicillanic acid production.
Potential pathophysiological mechanisms of ultrafine particle toxic effects in humans
Authors: Jovic-Stosic Jasmina , Jovasevic-Stojanovic Milena
Published: March 2009

Epidemiological and clinical studies suggested the association of the particulate matter ambient air pollution and the increased morbidity and mortality, mainly from respiratory and cardiovascular diseases. The size of particles has great influence on their toxicity, because it determines the site in the respiratory tract where they deposit. The most well established theory explaining the mechanisms behind the increased toxicity of ultrafine particles (UFP, < 0.1 ?m) is that it has to do with the increased surface area and/or the combination with the increased number of particles. Biological effects of UFP are also determined by their shape and chemical composition, so it is not possible to estimate their toxicity in a general way. General hypothesis suggested that exposure to inhaled particles induces pulmonary alveolar inflammation as a basic pathophysiological event, triggering release of various proinflammatory cytokines. Chronic inflammation is a very important underlying mechanism in the genesis of atherosclerosis and cardiovascular diseases. UFP can freely move through the circulation, but their effects on the secondary organs are not known yet, so more studies on recognizing toxicological endpoints of UFP are needed. Determination of UFP toxicity and the estimation of their internal and biologically active dose are necessary for the evidence based conclusions connecting air pollution by UFP and human diseases. .
Synthesis of perfluorosulfonate ionomer-stabilized platinum colloid and its application in direct methanol fuel cells
Authors: Jiang L. , Sun G.Q. , Wang Q. , Xin Q.
Published: March 2009

Pt colloid was synthesized by the reduction of hexachloroplatinic acid with formaldehyde in the presence of a stabilizer (a cation-exchanged polymer - perfluorosulfonate ionomer (PFSI) or Teflon) or without any stabilizers. The average size of platinum particles with a stabilizer, characterized by a transmission electron microscopy and X-ray diffraction, is in a nanometer range in comparison with the particle agglomeration without any stabilizers. Highly dispersive 40 wt. % Pt/C catalyst obtained from the PFSI-stabilized Pt colloid shows much better performance than its counterpart with Teflon as a stabilizer or without any stabilizer according to the cyclic voltammetric (CV) characterization and the single direct methanol fuel cell (DMFC) performance testing. It is strongly suggested that the proton-conducting ionomer could smooth the reaction pathway by facilitating the proton transport, while Teflon inhibit the active sites, though both of them can inhibit the particle growth. The improved fuel cell performance is attributed to the small particles and the unhindered transport of protons/electrons ascribed to the intimate contact of Pt and proton-conducting ionomer.
Monitoring air quality, objectives and design
Authors: Sivertsen Bjarne
Published: March 2009

Today's environmental information systems combine the latest sensor and monitor technologies with data transfer; data base developments, quality assurance, statistical and numerical models and advanced computer platforms for processing, distribution and presenting data and model results. Geographical Information Systems (GIS) are an important tool, particular for the presentation of data. An important part of the integrated air quality management system is the establishment of a monitoring programme for air quality. Once the objective of the air monitoring programme is well defined, a certain operational sequence has to be followed. The best possible definition of the air pollution problem, together with the analysis of the personnel, budget and equipment available, represent the basis for the final design. The specification of monitoring objectives, data quality objectives together with proper site selection, data quality assurance and well-defined data presentation and assessment are important elements in this process.
The Support Vector Regression with the parameter tuning assisted by a differential evolution technique: Study of the critical velocity of a slurry flow in a pipeline
Authors: Lahiri S.K. , Ghanta K.C.
Published: March 2009

This paper describes a robust Support Vector regression (SVR) methodology, which can offer a superior performance for important process engineering problems. The method incorporates hybrid support vector regression and a differential evolution technique (SVR-DE) for the efficient tuning of SVR meta parameters. The algorithm has been applied for the prediction of critical velocity of the solid-liquid slurry flow. A comparison with selected correlations in the literature showed that the developed SVR correlation noticeably improved the prediction of critical velocity over a wide range of operating conditions, physical properties, and pipe diameters.
The optimization of zinc dialkyldithiocarbamates synthesis and determination of their antioxidant activity
Authors: Marinkovic Aleksandar , Milosavljevic Milutin , Milenkovic Dragan , Ivanovic Goran
Published: March 2009

A two-step optimized laboratory synthetic method of zinc dialkyldithiocarbamates is presented. In the course of the first phase, a sodium salt of dialkyldithiocarbamic acid has been synthesized from the dialkylamines, carbon disulfide and sodium hydroxide. The synthesis of zinc dialkyldithiocarbamates was achieved by the precipitation from sodium dialkyldithiocarbamic acid by zinc sulfate under the optimized conditions. The synthesized products have been characterized by FTIR, 1H and 13C NMR, AAS spectroscopic methods, as well as by elemental analysis and melting points. Kinetic studies of the motor oil oxidation inhibited by synthesized compounds have been tested using a standard method.
The simultaneous spectrophotometric determination of trimazolin and phenylephrine hydrochloride in nasal preparations
Authors: Savic Ivana , Nikolic Goran , Savic Ivan , Bankovic Vladimir
Published: March 2009

This paper presents the experimental results for the simultaneous spectrophotometric determination of two active components in nasal solutions. The resolution of two-component mixtures of timazolin and phenylephrine has been accomplished by using partial least-squares. The method comprised of the absorptivity measurement in a nasal solution at wavelengths of 265 and 272 nm, respectively. Notwithstanding the presence of two components and their high degree of spectral overlap, they have been determined simultaneously with high accuracy and precision, with no interference, rapidly and without resorting to extraction procedures using non aqueous solvents. This method was tested and validated for various parameters according to ICH guidelines. The results demonstrated that the procedure is accurate, precise and reproducible (relative standard deviation <2 %), while being simple, cheap and less time consuming. The method was applied for the analysis of these drug substances in their commercial pharmaceutical formulations.
Cleaner metallurgical industry in Serbia: A road to the sustainable development
Authors: Radovic Nenad , Kamberovic Zeljko , Panias Dimitrios
Published: March 2009

Since the sustainable development has been a global and fundamental objective, a metallurgical industrial sector faces some of the most difficult sustainability challenges of any industrial sector. On the other hand, the metallurgical production in Serbia is a very important part of the economy. Due to present facilities and technologies, metallurgical companies face a great challenge to fulfill the requirements introduced by legislature referring to the cleaner production and sustainable development. The state of art in the production, facilities, pollution with some answers to imposed challenges is presented.
Bioethanol production from intermediate products of sugar beet processing with different types of Saccharomyces cerevisiae
Authors: Rankovic Jovana , Dodic Jelena , Dodic Sinisa , Popov Stevan
Published: March 2009

The use of biofuels as an alternative to fossil fuels has expanded in the last few decades. The aim of this study was to examine the application of different strains and forms of Saccharomyces cerevisiae for raw, thin and thick juice fermentation in order to produce bioethanol. According to the obtained results the strain applied in the form of pressed blocks with 70 % w/w moisture, attained higher value of the specific growth rate and lower value of ethanol yield in comparison with strains applied in dried form. In all culture media attained efficiency of sugar utilization was at least from 98-99 % w/w. Maximum productivity was achieved around 30th hour of fermentation and amounted ?1.8 g l?? h?? for all applied yeast strains. Therefore, optimal duration of the process in technical and economic terms should be considered.
Breadmaking characteristics of dough with extruded corn
Authors: Filipovic Nada , Soronja-Simovic Dragana , Filipovic Vladimir
Published: March 2009

Extrusion cooking is a thermal process often practiced in food, chemical and feed industry. Due to extrusion, nutritive value, texture, sensor characteristics and hygiene are improved. The influence of extruded corn grain and bread improver quantity on rheological and sensory characteristics of bread was investigated in this paper. Experiment was planed according to factorial plan 32 with independent variables: Quantity of extruded corn (10-30 % based in wheat flour, variation interval 10) and improver (0-0.4 % based on flour, variation interval 0.2). The influence of extruded corn on Dough handling is illustrated by extensigraph data: In comparison to the dough without corn, area is decreasing 50 to 60 % and resistance to stretching 15 to 20 %. The addition of commercial bread improver, regardless the quantity of extruded corn is beneficial contributing to improved extensigraph data up to 30 %. By substituting wheat flour with 10 to 20 % of extruded corn along with proper quality of bread improver, bread quality is satisfying and stalling is significantly improved. In the production of so-called mixed corn bread (30 % of extruded corn) extrusion is contributing to retard stalling and prolonged shelf-life.
Adsorption characteristics of activated carbon hollow fibers
Authors: Kaludjerovic Branka , Kljajevic Ljiljana , Sekulic Danijela , Stasic Jelena , Bogdanov Zarko
Published: March 2009

Carbon hollow fibers were prepared with regenerated cellulose or polysulfone hollow fibers by chemical activation using sodium phosphate dibasic followed by the carbonization process. The activation process increases the adsorption properties of fibers which is more prominent for active carbone fibers obtained from the cellulose precursor. Chemical activation with sodium phosphate dibasic produces an active carbon material with both mesopores and micropores.
What is neoclassical economics? The three axioms responsible for its theoretical oeuvre, practical irrelevance and, thus, discursive power
Authors: Arnsperger Christian , Varoufakis Yanis
Published: March 2009

This paper offers a precise definition of neoclassical economics based on three axioms which lie at the latter's foundations. This definition is all inclusive in that it applies as much to the neoclassical economic models of the late 19th century as it does to today's more flexible and 'inclusive' models. The paper argues that these axioms, simultaneously, (a) provide the foundation for neoclassicism?s discursive success within the social sciences and (b) are the deep cause of its theoretical failure. Moreover, (a) and (b) reinforce one another as neoclassicism's discursive power (which is largely due to the hidden nature of its three foundational axioms) makes it even less likely that it will conduct an open, pluralist debate on its theoretical foundations (i.e. the three axioms which underpin it).
European social model vs directive Bolkestein
Authors: Redzepagic Srdjan
Published: March 2009

In this article is elaborated the actually question which is developed and discussed it the European Union is the European Social Model (ESM). It is a vision of society that combines sustainable economic growth with ever-improving living and working conditions. This implies full employment good quality jobs, equal opportunities, social protection for all, social inclusion, and involving citizens in the decisions that affect them. As the Euro-zone is struggling to move away from a dramatic slump in its economy and while the Lisbon Strategy and its potential for economic growth, strongly needs reactivation, the debates over the Europe have raised again the issue of a sustainable social agenda for the European Union. Recently, Europe's political leaders defined the ESM, specifying that it "is based on good economic performance, a high level of social protection and education and social dialogue". An important topic of the discussion nowadays is the Directive of the European Parliament and of the Council on services in the internal market so called "Bolkestein directive". The importance of this article is to give us the answer to the following question: would we have French goods available in French supermarkets all over Poland and no Polish services allowed in France? The EU would be unthinkable without the full implementation of the four freedoms. This is a good directive, going in the good direction.
Inflation targeting with special review on application in Serbia
Authors: Fabris Nikola
Published: March 2009

Inflation targeting represents monetary regime primarily applied in New Zealand in 1989. Since then, this regime has extended into over 30 countries and it is recommended by International Monetary Fund within its business arrangements in last couple of years. The last country that announced this regime was Serbia. It is regularly introduced when previous one had poor performances. Its nature is determined by targeted inflation rate, high level of transparency in monetary policies conducting, absence of secondary goals as well as responsibility for realized targeted inflation rates. Within work theoretical presumptions are analyzed regarding implementation of this regime, and the most important aspects of its functioning in chosen countries, and its application in Serbia is a subject of particular consideration.
La persistance des ecarts de richesse au sein de l’europe elargie: L’apport de l’econometrie des panels heterogenes non-stationnaires
Authors: Tykhonenko Anna
Published: March 2009

(francuski) Le but de cet article est de tester l?hypoth?se de convergence r?elle au sein de l?Europe-24 ? la lumi?re de l??conom?trie des donn?es de panel h?t?rog?nes nonstationnaires. Nous employons pour cela une approche en termes de persistance des ?carts des revenus par t?te au sein de l?Europe ?largie vers l?Est. Les tests de racine unitaire en panel permettent de conclure ? l?absence de la persistance des ?carts de richesse dans le temps. A l?aide de l?approche par la coint?gration en panel, nous cherchons alors ? identifier les variables de "contr?le" de la convergence r?elle entre les Etats membres de l?UE.
Which currency exchange regime for emerging markets?: Corner solutions under question
Authors: Allegret Jean-Pierre
Published: March 2009

During the 90s, recurrent exchange rate crises in emerging markets have shown the extreme fragility of soft pegs, the so-called intermediate exchange rate regimes. As a result, numerous academic economists but also International institutions have promoted a new consensus: domestic authorities have to choose their exchange rate regime between only two solutions called corner solutions or extreme regimes: hard pegs or independent floating. This paper questions de relevance of this consensus. We stress the main advantages and costs of each corner solution. We conclude by stressing that intermediate regimes associated to an inflation targeting framework seem a better solution for emerging countries than corner solutions.
Gut Morphometrics in the Long-Tailed Duck Clangula Hyemalis Wintering on the Polish Baltic Coast
Authors: Działa-Szczepańczyk Ewa
Published: March 2009

Gut Morphometrics in the Long-Tailed DuckClangula HyemalisWintering on the Polish Baltic Coast

The study included guts of 140 individuals of the long-tailed duckClangula hyemalisobtained in autumn and winter of 1993-2000 in the western part of the Polish Baltic Coast. The following morphometric characters were analysed: duodenum length (DL), combined jejunum and ileum length (JIL), small intestine length (SIL), combined terminal intestine and cloaca length (TCL), and combined length (CBL) and weight (CBW) of both caeca. In the analysis the birds' sex and age were taken into consideration, as well as their body size characterised by body weight, body length, and sternum length. Ontogenetic differences in the gut morphometric characters were more pronounced in males than in females, and immature drakes were characterised by higher average values of JIL and CBW, compared to adult males. Besides the CBL and CBW, sexual dimorphism was manifest in the body size and other gut measurements - those parameters achieved higher average values in males than in females. No such differences were recorded with respect to relative parameters: DL, SIL, and TCL expressed as the percentage of the birds' body length. In case of JIL, CBL, and CBW no relation with any of the body size parameters was found. No relevant relations between SIL and JIL, and the measurements of CBL and TCL were noticed.
Retrospective multicentre study of methicillin‐resistant Staphylococcus aureus infections in 115 horses
Authors: ANDERSON M. E. C. , LEFEBVRE S. L. , RANKIN S. C. , ACETO H. , MORLEY P. S. , CARON J. P. , WELSH R. D. , HOLBROOK T. C. , MOORE B. , TAYLOR D. R. , WEESE J. S.
Published: March 2009

Reasons for performing study: Methicillin‐resistant Staphylococcus aureus (MRSA) is an emerging veterinary and zoonotic pathogen, associated with increasing reports of disease in horses.

Objectives: To provide an overview of the characteristics of clinical MRSA infections in horses.

Methods: A retrospective case study was performed on 115 horses admitted to 6 participating veterinary teaching hospitals in Canada and the United States between 2000 and 2006, and diagnosed with clinical MRSA infection. Descriptive statistics, univariate and multivariable analyses for community‐ (CA) vs. hospital‐associated (HA) MRSA infections, and survival vs. nonsurvival at discharge were performed.

Results: The age range of MRSA‐infected horses was zero (born in hospital) to 31 years. HA (58/114, 50.9%) and CA infections (56/114, 49.1%) were equally common. Infection of surgical incisions was most frequently reported (44/115, 38.0%). Overall 93/111 (83.8%) cases survived to discharge. Previous hospitalisation and treatment with gentamicin were associated significantly with CA‐MRSA, whereas infected incision sites were associated significantly with HA‐MRSA. Factors significantly associated with nonsurvival included i.v. catheterisation, CA‐MRSA infection and dissemination of infection to other body sites.

Conclusions: Equine MRSA infections have a broad range of clinical presentations, appear to be primarily opportunistic and the overall prognosis for survival to discharge is good.

Potential relevance: These results should help direct future research with regard to investigation of risk factors for equine MRSA infection in community and hospital populations.
Pharmacokinetics of detomidine and its metabolites following intravenous and intramuscular administration in horses
Authors: GRIMSRUD K. N. , MAMA K. R. , THOMASY S. M. , STANLEY S. D.
Published: March 2009

Reasons for performing study: Detomidine is commonly used i.v. for sedation and analgesia in horses, but the pharmacokinetics and metabolism of this drug have not been well described.

Objectives: To describe the pharmacokinetics of detomidine and its metabolites, 3‐hydroxy‐detomidine (OH‐detomidine) and detomidine 3‐carboxylic acid (COOH‐detomidine), after i.v. and i.m. administration of a single dose to horses.

Methods: Eight horses were used in a balanced crossover design study. In Phase 1, 4 horses received a single dose of i.v. detomidine, administered 30 μg/kg bwt and 4 a single dose i.m. 30 üg/kg bwt. In Phase 2, treatments were reversed. Plasma detomidine, OH‐detomidine and COOH‐detomidine were measured at predetermined time points using liquid chromatography‐mass spectrometry.

Results: Following i.v. administration, detomidine was distributed rapidly and eliminated with a half‐life (t1/2(el)) of approximately 30 min. Following i.m. administration, detomidine was distributed and eliminated with t1/2(el)of approximately one hour. Following, i.v. administration, detomidine clearance had a mean, median and range of 12.41, 11.66 and 10.10–18.37 ml/min/kg bwt, respectively. Detomidine had a volume of distribution with the mean, median and range for i.v. administration of 470, 478 and 215–687 ml/kg bwt, respectively. OH‐detomidine was detected sooner than COOH‐detomidine; however, COOH‐detomidine had a much greater area under the curve.

Conclusions and potential relevance: These pharmacokinetic parameters provide information necessary for determination of peak plasma concentrations and clearance of detomidine in mature horses. The results suggest that, when a longer duration of plasma concentration is warranted, the i.m. route should be considered.
Endfolium sclerosis in temporal lobe epilepsy diagnosed preoperatively by 3-tesla magnetic resonance imaging
Authors: Iwasaki Masaki , Nakasato Nobukazu , Suzuki Hiroyoshi , Tominaga Teiji
Published: March 2009

A 34-year-old man presented with intractable temporal lobe epilepsy. Three-tesla magnetic resonance imaging revealed increased T2 signal intensity and volume loss limited to the CA4 region of the right hippocampus. A right anterior temporal lobectomy and amygdalohippocampectomy were performed. Histological examination of the hippocampus disclosed severe neuron loss limited to the CA4 region, consistent with the preoperative imaging, which is a pattern known as endfolium sclerosis. Close inspection of the internal hippocampal anatomy with high-field MR imaging is useful in patients with temporal lobe epilepsy, because endfolium sclerosis may be associated with less chance of seizure freedom after temporal lobectomy.
Retreatment of trigeminal neuralgia with Gamma Knife radiosurgery: is there an appropriate cumulative dose?
Authors: Dvorak Tomas , Finn Arkadiy , Price Lori Lyn , Mignano John E. , Fitzek Markus M. , Wu Julian K. , Yao Kevin C.
Published: March 2009

Object

Trigeminal neuralgia (TN) is a disorder of the trigeminal nerve that results in intense episodic pain. Primary treatment with Gamma Knife surgery (GKS) is well established; however, a significant number of patients experience recurrence of TN over time. Repeat GKS can be performed, but the retreatment dose has not been well established. In this study, the authors present their institutional retreatment results and compare them with other series.

Methods

Between December 2003 and January 2006, 28 patients were treated at Tufts Medical Center with repeat GKS for recurrence of TN. All patients had been initially treated with GKS at this institution, and only those with significant pain improvement were offered retreatment. The maximum dose was prescribed using a single isocenter; the 4-mm collimator was used. The initial median GKS dose was 80 Gy, the median retreatment dose was 45 Gy, and the median cumulative dose was 125 Gy. The median time between GKS procedures was 18.1 months. Facial pain outcomes were defined using the Marseille scale. Excellent outcome was defined as no pain (with or without medications), and good outcome was defined as > 50% pain relief. Toxicity was categorized as none, mild, or bothersome. The median clinical follow-up after the second GKS was 19.7 months. Our clinical outcomes were compared with 8 previously reported retreatment series (including 1 abstract), both for rate of pain control and for rate of complications.

Results

Outcomes after the second GKS were excellent in 29% (8 patients), good in 32% (9), and poor in 39% (11). Four patients (14%) experienced no improvement after repeat GKS. Eight patients (29%) experienced new trigeminal nerve dysfunction, including numbness (11%), paresthesia (14%), dysesthesia (4%), taste alteration (11%), and bite weakness (4%). None of these were bothersome. No patient developed corneal numbness. Univariate analysis failed to reveal any significant predictors of pain control or complications.

Seven published peer-reviewed retreatment series and the authors' data (total 215 patients) were analyzed. There was a cumulative dose-response relationship for both pain control (p = 0.04) and new trigeminal dysfunction (p = 0.08). Successful pain control was strongly correlated with development of new dysfunction (p = 0.02). A cumulative dose > 130 Gy was more likely to result in successful (> 50%) pain control, but was also more likely (> 20%) to result in development of new dysfunction.

Conclusions

Successful retreatment of patients in whom the initial GKS treatment fails is feasible. Patients who respond initially may be at a higher risk of retreatment-related complications. There appears to be a dose-response relationship for both pain control and development of new side effects. It is important to counsel and treat patients individually based on this dose-response relationship.
Effect of trans sodium crocetinate on brain tumor oxgenation
Authors: Sheehan Jason , Sherman Jonathan , Cifarelli Christopher , Jagannathan Jay , Dassoulas Kasandra , Olson Claire , Rainey Jessica , Han Shaojie
Published: March 2009

Object

Glioblastoma multiforme tumors typically exhibit regions of hypoxia. Hypoxic regions within the tumor make cells less sensitive to radiosurgery and radiation therapy. Trans sodium crocetinate (TSC) has been shown to be a radiosensitizer. The goal of this research was to elucidate the underlying mechanism of TSC's radiosensitizing effect.

Methods

A rat C6 glioma model was used. The C6 glioma cells were stereotactically injected into the rat brain to create a tumor. Two weeks later, MR imaging was used to confirm the presence of a glioma. Following demonstration on MR imaging of a brain tumor, animals were randomized into 1 of 2 groups: 1) TSC alone (100 μg/kg), or 2) saline control. Licox probes were inserted into the brain tumor and contralateral cerebral hemisphere. Tissue oxygenation measurements were recorded before and after intravenous infusion of either TSC or saline.

Results

Not surprisingly, tissue oxygenation measurements revealed that the brain tumor was hypoxic relative to the contralateral cerebral hemisphere brain tissue. Two to 8 minutes after TSC was infused, tissue oxygenation measurements in the brain tumor increased above baseline by as much as 60%. After this temporary elevation following TSC infusion, tumor oxygenation measurements returned to baseline. No significant elevations in tissue oxygenation were seen on the contralateral side. Similarly, the saline vehicle was not observed to increase tissue oxygenation in either the brain tumor or the contralateral brain tissue.

Conclusions

Administration of TSC transiently improves tissue oxygenation in hypoxic gliomas. Such an effect is one potential mechanism for the radiosensitization previously observed after addition of TSC.
Assessment and mapping of snow avalanche risk in Russia
Authors: Seliverstov Yuri , Glazovskaya Tatiana , Shnyparkov Alexander , Vilchek Yana , Sergeeva Ksenia , Martynov Alexei
Published: March 2009

The term ‘risk’ can be defined as the probability of unfavourable consequences or negative effects. Risk can be expressed by means of various indices, such as collective or social risk (possible number of dead), individual risk (probability of a person’s death within a certain territory during 1 year), probability of losses, etc. This paper is a case study of the small-scale assessment and mapping of individual avalanche risk focused on the two regions of Russia with the highest levels of avalanche activity: the northern Caucasus and the mountainous parts of Sakhalin island. The basic indices applied for individual avalanche risk estimation are: recurrence interval of avalanches (avalanche frequency), percentage of the whole investigated territory that is occupied by avalanche-prone areas, duration of avalanche danger period, probability of a person’s stay in an avalanche-prone area during 1 day (24 hours) and during 1 year, total population of the area and its density. The results of individual avalanche risk assessment, undertaken for the territory of Russia as a whole, show that its values generally do not exceed the admissible level (from 1×10–6 to 1×10–4). However, some areas of the northern Caucasus, including famous alpine skiing resorts (Krasnaya Poliana, Dombai, the Mount Elbrus region, etc.), and of Sakhalin, including the environs of towns (Kholmsk, Nevel’sk) and other smaller human settlements, are characterized by an unacceptable level of risk. In the aggregate, areas with an unacceptable (>1×10–4) level of individual avalanche risk comprise about 7% of the whole avalanche-prone territory of the northern Caucasus, those with an admissible level comprise 52% and those with an acceptable level (<1×10–6) 41%. The corresponding values for Sakhalin are 0.1%, 14.8% and 85.1%.
Experimental determination of snow sublimation rate and stable-isotopic exchange
Authors: Neumann T.A. , Albert M.R. , Lomonaco R. , Engel C. , Courville Z. , Perron F.
Published: March 2009

Snow sublimation is a fundamental process that affects the snow crystal structure and is important for ice-core interpretation, remote sensing, snow hydrology and chemical processes in snow. Prior studies have shown that sublimation can change the isotopic content of the remaining snow; these studies have inferred sublimation rates using field data, and were unable to control many of the environmental parameters that determine sublimation rate (e.g. temperature, relative humidity, snow microstructure). We present sublimation rate measurements on snow samples in the laboratory, where we have controlled many of these parameters simultaneously. We use the same experimental apparatus to determine sublimation rate, investigate the isotopic effects of sublimation, and study the isotopic exchange between vapor and solid. Our results suggest that pore spaces in snow are almost always at saturation vapor pressure; undersaturation may be possible in large pore spaces or in regions of rapid interstitial airflow. We present a revised formulation for determining the mass-transfer coefficient for snow as a linear function of Reynolds number (hm = 0.566Re + 0.075), estimate the fractionation coefficient for sublimating snow, and provide evidence for isotopic exchange between vapor and solid.
Simple relations for the close-off depth and age in dry-snow densification
Authors: Salamatin Andrey N. , Lipenkov Vladimir Ya.
Published: March 2009

A physical model for the snow/firn densification process (Salamatin and others, 2006) and Martinerie and others’ (1992, 1994) correlation for the firn density at the pore closure are employed to perform a scale analysis and computational experiments in order to deduce simplified relations for the close-off depth and ice age in quasi-stationary ice formation conditions. The critical snow density at which ice-grain rearrangement stops is used to take into account variability of snow structures subjected to densification. The results obtained are validated on a representative set of ice-core data from 22 sites which covers wide ranges of present-day temperatures and ice accumulation rates. A simple analytical approximation for the density–depth profile is proposed.
Reconstruction of snow/firn thermal diffusivities from observed temperature variation: application to iceberg C16, Ross Sea, Antarctica, 2004–07
Authors: Sergienko Olga V. , MacAyeal Douglas R. , Thom Jonathan E.
Published: March 2009

Two inverse methods are proposed as a means of estimating the thermal diffusivity of snow and firn from continuous measurements of their temperature. The first method is applicable to shallow depths where temperature experiences diurnal variations, and is based on the fact that phase and amplitude of these diurnal variations are functions of the thermal diffusivity. The second method is applicable to the deeper part of the firn layer, and is based on a simple least-squares estimation technique. The methods applied here differ from various methods used for borehole paleothermometry in that observations are continuous in time and performance constraints on model/data misfit can be applied over a finite temporal period. Both methods are tested on temperature records from thermistor strings operating in the upper 2.5 m of firn on iceberg C16 (Ross Sea, Antarctica) from 2004 to 2007. Results of the analysis show promise in identifying melting events and the movement and refreezing of meltwater within the snow/firn layer.
Winter regime of temperature and precipitation as a factor of snow-cover distribution and its stratigraphy
Authors: Golubev Vladimir N. , Petrushina Marina N. , Frolov Denis M.
Published: March 2009

The investigation of spatial and temporal variability of the snow cover in northern Eurasia (snow depth, density, thermal characteristics, water equivalent) includes large-scale fieldwork, modelling and analysis of meteorological data of two winters (2004/05 and 2005/06) from 38 weather stations situated in different climatic conditions and physico-geographical zones. Common regularities and features of snow-cover variability are revealed for these winters, despite their contrasting temperature and precipitation regimes and differences from an average winter, as the time of appearance, duration and depth of snow cover, the number of snowfalls and date of melting. The modelling of snow-cover stratigraphy is based on viscous compression and recrystallization laws. Meteorological information (temperature, wind velocity and precipitation) is used as input for the model. The output is the specific snow-cover stratigraphy according to positioning in different physical–geographical regions and due to the possible variation as determined by winter temperature and precipitation regimes. The peculiarity of snow-cover stratigraphy at the regional scale depends on the meteorological conditions of its formation as well as on the character of landscapes. A satisfactory correlation of the modelled typical columns of the snow cover formed in 2004/05 and 2005/06 in different regions of Russia and of real columns is revealed.
Modelling of snow avalanche dynamics: influence of model parameters
Authors: Bozhinskiy A.N.
Published: March 2009

The three-parameter hydraulic model of snow avalanche dynamics including the coefficients of dry and turbulent friction and the coefficient of new-snow-mass entrainment was investigated. The ‘Domestic’ avalanche site in Elbrus region, Caucasus, Russia, was chosen as the model avalanche range. According to the model, the fixed avalanche run-out can be achieved with various combinations of model parameters. At the fixed value of the coefficient of entrainment me , we have a curve on a plane of the coefficients of dry and turbulent friction. It was found that the family of curves ( me is a parameter) are crossed at the single point. The value of the coefficient of turbulent friction at the cross-point remained practically constant for the maximum and average avalanche run-outs. The conclusions obtained are confirmed by the results of modelling for six arbitrarily chosen avalanche sites: three in the Khibiny mountains, Kola Peninsula, Russia, two in the Elbrus region and one idealized site with an exponential longitudinal profile. The dependences of run-out on the coefficient of dry friction are constructed for all the investigated avalanche sites. The results are important for the statistical simulation of avalanche dynamics since they suggest the possibility of using only one random model parameter, namely, the coefficient of dry friction, in the model. The histograms and distribution functions of the coefficient of dry friction are constructed and presented for avalanche sites Nos 22 and 43 (Khibiny mountains) and ‘Domestic’, with the available series of field data.
Chemical and Antioxidant Studies of Citrus macroptera
Authors: Chowdhury Sadia A , Sohrab M Hossain , Datta Bidyut K , Hasan Choudhury M
Published: March 2009

Lupeol (1) and Stigmasterol (2) were isolated from the crude extracts of the stem bark of Citrus macroptera (Family: Rutaceae) for the first time. The n-hexane, dichloromethane and methanol extracts were screened in vitro for antioxidant activity using the 1, 1-diphenyl-2-picrylhydrazyl-hydrate (DPPH) free radical scavenging assay. The hot methanol extract showed potential antioxidant activity (IC50: 178.96 Î¼g/ml) whereas the cold methanol and dichloromethane extracts showed moderate activity (IC50: 242.78 Î¼g/ml and 255.78 Î¼g/ml respectively). Mild antioxidant activity was observed with the n-hexane extract of the stem bark of Citrus macroptera (IC50: 422.94 Î¼g/ml). Key words: Citrus macroptera, Rutaceae, Lupeol, Stigmasterol, Antioxidant. Â  doi: 10.3329/bjsir.v43i4.2235 Bangladesh J. Sci. Ind. Res. 43(4), 449-454, 2008
Synthesis of Ca-hydroxyapatite Bioceramic from Egg Shell and its Characterization
Authors: Ahmed Samina , Ahsan Mainul
Published: March 2009

Ca-hydroxyapatite (HA) was synthesised from egg shell under different conditions and characterised by using AAS, FT-IR, XRD, SEM and EDS techniques. The results of these analyses combined together indicate that sintered HA sample1 resembles the feature of pure and single apatite phase having hexagonal structure. A Ca/P molar ratio of 1.69 was achieved in this case. On the other hand HA obtained from calcined egg shell is a combination of both amorphous and crystalline phase and revealed a sub-stoichiometric Ca-deficient apatite form with a Ca/P ratio of 1.50. Keywords: Ca-hydroxyapatite, Biomaterials, Hexagonal, stoichiometric apatite, Ca-deficient apatite Â  doi: 10.3329/bjsir.v43i4.2240 Bangladesh J. Sci. Ind. Res. 43(4), 501-512, 2008
Investigation on Accuracies of Real Time Kinematic GPS for GIS Applications
Authors: Mekik Cetin , Arslanoglu Murat
Published: March 2009

People specialised in or in contact with Geographic Information Systems (GIS) at administrative or user level have been looking for economical and productive means for data acquisition tasks since the advent of GIS. Because the data acquisition constitutes major part of any GIS, scientific community, especially geodetic surveyors, have come up with a solution of real time kinematic (RTK) GPS. This paper investigates the performance (internal and external accuracy) of RTK GPS. For this purpose, two separate tests are conducted. In the first test three cases are taken in consideration for internal accuracy, namely, identical satellite configuration, different satellite configuration and different reference station. In the second test, two cases are put into study in which RTK GPS results are compared with static GPS and conventional terrestrial method. The results from all the tests have proved that this modern technique is very much suitable for data acquisition of GIS’s as well as it is efficient and economical.
Energy Sustainability: A Pragmatic Approach and Illustrations
Authors: Rosen Marc A.
Published: March 2009

Many factors to be appropriately addressed in moving towards energy sustainability are examined. These include harnessing sustainable energy sources, utilizing sustainable energy carriers, increasing efficiency, reducing environmental impact and improving socioeconomic acceptability. The latter factor includes community involvement and social acceptability, economic affordability and equity, lifestyles, land use and aesthetics. Numerous illustrations demonstrate measures consistent with the approach put forward, and options for energy sustainability and the broader objective of sustainability. Energy sustainability is of great importance to overall sustainability given the pervasiveness of energy use, its importance in economic development and living standards, and its impact on the environment.
The evolution of floral variation without pollinator shifts inGorteria diffusa(Asteraceae)
Authors: Ellis Allan G. , Johnson Steven D.
Published: March 2009

One of the most widely accepted explanations for floral diversification in angiosperms is the pollinator‐shift model developed by Verne Grant and Ledyard Stebbins. According to this model, the most profound changes in floral traits (such as morphology, color, patterning and scent) occur when plants undergo adaptive shifts between pollinator classes. We tested this model through investigations of geographical variation in floral form and pollinator assemblages in the South African annual daisyGorteria diffusa. This species has elaborate insect‐like ornaments on the capitulum, which attract bee flies belonging to the genusMegapalpus. We found unprecedented levels of geographically structured intraspecific variation and identified 14 discrete forms that vary in the morphology and ornamentation of the capitulum. This variation is not due to phenotypic plasticity because differences among forms were maintained in plants grown from seed in a common garden experiment. Contrary to predictions from the pollinator‐shift model, all populations, regardless of floral phenotype, were pollinated primarily by a single species ofMegapalpusbee fly. Much of the extensive variation in floral form inG. diffusatherefore appears to have arisen without evolutionary shifts between pollinator types.
POSSIBILITIES OF USING LIQUEFIED OIL GAS IN TRANSPORT
Authors: Kuprys Algirdas , Kugelevičius Jonas
Published: March 2009

The trends of the input of an alternative type of fuel in the transport system of the European Union are analysed. Taking into account the measures of promoting liquefied petroleum gas (LPG) consumption in road transport, a bundle of specific variables was analysed to understand the consumers for making decision to use LPG in cars. It is revealed that the obtained models enable to evaluate the behaviour of consumers and conditioning transition to using an alternative type of fuel in transport industry. The proposed models were assessed conducting statistic and sensitivity analysis. The payoff of the additional equipment of the car was analysed considering the driven distance with an alternative type of fuel. The pay‐off analysis of supplementary equipment depending on the ratio of standard and alternative fuel prices is presented.
The predatory miteMetaseiulusoccidentalis: mitey small and mitey large genomes
Authors: Hoy Marjorie A.
Published: March 2009

Metaseiulus occidentalisis a representative of an important family of mites (Arthropoda: Chelicerata: Acari: Phytoseiidae) that are effective predators of pest mites in agricultural crops around the world. Like many arthropods, this mite contains multiple genomes, including the genomes of several microbial symbionts as well as its own mitochondrial and nuclear genomes. The mitochondrial genome is “mitey” large at 25 kb, due to duplication and triplication of genes. By contrast, the nuclear genome is “mitey” small at 88 Mb. This mite has a parahaploid genetic system, tolerates inbreeding, and has a haploid chromosome number of 3. This predator was genetically improved for use in agriculture by developing strains that lacked the ability to overwinter in diapause or were resistant to multiple pesticides, and can be genetically modified using recombinant DNA methods. Sequencing the nuclear genome would provide useful insights that could enhance genetic improvement programs that would result in improved pest management, could provide genes needed to resolve the evolutionary relationships of this family, and could serve as a model for understanding the evolution and genetics of chelicerate arthropod predators.