bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimal Multiple Stopping of Linear Diffusions
Authors: Carmona René , Dayanik Savas
Published: June 2008

Motivated by the analysis of financial instruments with multiple exercise rights of American type and mean reverting underlyers, we formulate and solve the optimal multiple-stopping problem for a general linear regular diffusion process and a general reward function. Instead of relying on specific properties of geometric Brownian motion and call and put option payoffs as in most of the existing literature, we use general theory of optimal stopping for diffusions, and we illustrate the resulting optimal exercise policies by concrete examples and constructive recipes.
ERP Competence-Building Mechanisms: An Exploratory Investigation of Configurations of ERP Adopters in the European and U.S. Manufacturing Sectors
Authors: Masini Andrea , Van Wassenhove Luk N.
Published: June 2008

This paper contributes to the literature on enterprise resource planning (ERP) by pursuing two objectives. First, it identifies configurations of ERP adopters that have similar needs and develop similar competencies. Second, it tests the hypothesis that, to maximize benefits from their ERP projects, organizations should align their ERP competence-building mechanisms with the ERP needs that arise from their operational environment. The analysis of a sample of manufacturing companies that implemented ERP between 1995 and 2001 uncovers four distinct configurations representing different degrees of fit between needs and competence-building mechanisms: the frugal ERP, the extensive business process reengineering (BPR), the adaptive ERP, and the straitjacket. The results support our hypothesis and suggest that the consequences of a misfit between needs and competence-building mechanisms are more severe for companies that operate in complex and dynamic environments and have informal organizational structures than for firms with rigid structures that operate in simple and stable environments.
Role of the International Council for Laboratory Animal Science (ICLAS) in the promotion of care and use of laboratory animals in Southeast Europe
Authors: Kostomitsopoulos N. , Carbone Cecilia , Demers G.
Published: June 2008

The use of animals in research, teaching, and testing is regulated around the world by specific laws. Since regulatory processes are highly variable, a broad variability in the care and use of animals in scientific procedures exists internationally, as well as in the region of Southeast Europe. It is necessary to initiate an effort to promote the harmonization and improvement of laboratory animal science world-wide. The aim of this article is to explain the structure, organization, and aims of the International Council for Laboratory Animal Science (ICLAS) and to describe the role of this organization in the promotion of care and use of laboratory animals in this region of Europe.
Chthonius (Chthonius) globocicae (Chthoniidae, pseudoscorpiones), a new species of false scorpion from a cave in Montenegro
Authors: Curcic B.P.M. , Dimitrijevic R.N. , Tomic V.T.
Published: June 2008

A new species of false scorpion belonging to the family Chthoniidae, Chthonius (Chthonius) globocicae n. sp., is described from a cave in the village of Trnovo, near Virpazar in Montenegro. This endemic form is illustrated, diagnosed, and thoroughly compared to its phenetically closest congener [C. (C.) porevidi Curcic, Makarov & Lucic, 1998] from the area of Krivosije in Montenegro. Additionally, certain diagnostic and other features, taxonomic traits and biogeographical details are briefly discussed in the light of evolution of the karstification process in Montenegro.
Population doses from terrestrial gamma exposure in Serbia
Authors: Dragovic Snezana , Jankovic-Mandic Ljiljana , Momcilovic Milan , Onjia Antonije
Published: June 2008

Background: Terrestrial radiation emitted from naturally occurring radionuclides, such as 40K and radionuclides from the 238U and 232Th series and their decay products represent the main external source of irradiation to the human body. The purpose of this study was to provide a preliminary assessment of the doses from terrestrial exposure of population in Serbia and to estimate a potential radiation hazard for population inhabiting investigated areas. Methods: The gamma dose rates, external hazard indexes, and annual effective doses due to terrestrial naturally occurring radionuclides (238U, 232Th and 40K) were calculated based on their activities in soil samples in Serbia as determined by gamma-ray spectrometry. Results: The total absorbed gamma dose rate due to these radionuclides varied from 16.9 to 125 nGy h-1, with a mean of 62.8 nGy h-1. Assuming a 20% occupancy factor, the corresponding annual effective dose varied from 2.07 to 15.4?10-5 Sv with the mean value of 7.7?10-5 Sv, i.e. annual effective dose was in range of the world wide average values. Conclusion: According to the values of external hazard index obtained in this study (mean Hex = 0.35), the radiation hazard was insignificant for the population living in investigated areas.
Mesenteric cyst
Authors: Miljkovic Dragoslav , Gmijovic Dragojlo , Radojkovic Milan , Gligorijevic Jasmina , Radovanovic Zoran
Published: June 2008

Mesenteric cysts are rare abdominal findings. Due to absent or unspecific clinical presentation, very low incidence, and lack of adequate classification these cysts may sometimes represent a diagnostic and therapeutic challenge. We report a case of 37-year-old man with vague palpatory tenderness in left hypochondrium and paraumbilically and with palpable large intra-abdominal mass in whom mesenteric cyst was diagnosed using US and CT imaging. He was operated and cyst was extirpated in toto. Histopathological examination revealed a thick fibrous cyst wall with the signs of chronic inflammation and without inner epithelial lining, which suggested its traumatic origin. Considering the possibility of malignancy mesenteric cysts should be radically resected (with resection of adjacent organs if necessary) due to their strong relapsing potential and a tendency for sudden, progressive local enlargement if not removed in toto.
Flavonoids from the aerial parts of Onobrychis montana subsp. scardica
Authors: Godjevac Dejan , Pejin Boris , Zdunic Gordana , Savikin Katarina , Stesevic Danijela , Vajs Vlatka , Milosavljevic Slobodan
Published: June 2008

Rutin (1, main constituent) and two flavone C-glycosides, vitexin (2) and vitexin 2''-O-?-rhamnopyranoside (3) were isolated from the aerial parts of Onobrychis montana subsp. scardica. They were identified by 1H-NMR, 13C-NMR and UV-Vis spectroscopy (procedure with shift reagents), and high resolution ESI-MS. A relatively high content of 1 (5.27 mg/g of dry plant material), measured by HPLC, indicated O. montana subsp. scardica as a new natural source of this biologically active compound. The isolated flavonoid compounds might be of value as chemotaxonomic markers.
Anti-oxidative and antimicrobial activities of Hieracium pilosella L. extracts
Authors: Stanojevic Ljiljana , Stankovic Mihajlo , Nikolic Vesna , Nikolic Ljubisa
Published: June 2008

The anti-oxidative and antimicrobial activities of different extracts from Hieracium pilosella L. (Asteraceae) whole plant were investigated. The total dry extracts were determined for all the investigated solvents: methanol, dichloromethane, ethyl acetate and dichloromethane: methanol (9:1). It was found that the highest yield was obtained by extraction with methanol (12.9 g/100 g of dry plant material). Qualitative and quantitative analysis were performed by the HPLC method, using external standards. Chlorogenic acid, apigenin-7-O-glucoside and umbelliferone were detected in the highest quantity in the extracts. The qualitative and quantitative composition of the extracts depends on the solvent used. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging effect of the extracts was determined spectrophotometrically. The highest radical scavenging effect was observed in the methanolic extract, both with and without incubation, EC50 = 0.012 and EC50 = 0.015 mg ml-1, respectively. The antimicrobial activities of the extracts towards the bacteria (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis, Salmonella enteritidis and Klebsiella pneumoniae) and the fungi (Aspergillus niger and Candida albicans) were determined by the disc diffusion method. The minimal inhibitory concentrations were determined for all the investigated extracts against all the mentioned microorganisms.
Franck-Condon factors and r-centroids for the diatomic fluorides of germanium and silicon
Authors: Kanagaprabha S. , Palanichamy Rajeswara , Sathiyabama V.
Published: June 2008

A suitable potential energy function was found by analysing the potential functions proposed by Morse, Mohammad and Rafi et al. for the A2?+-X2?3/2 and B2?+-X2?3/2 band systems of GeF and the 1?-1? band system of SiF. It was found that the potential proposed by Rafi et al. is in close agreement with the Rydberg-Klein-Rees (R-K-R) potential. Using this potential, the wave functions were evaluated by the Wentzel-Kramer-Brillouin (W-K-B) method. The Franck-Condon factors and r-centroids were computed by a numerical integration technique. The results are compared with available theoretical values. The intensities of the various bands were investigated.
Comparative screening of the anti-oxidant and antimicrobial activities of Sempervivum marmoreum L. extracts obtained by various extraction techniques
Authors: Stojicevic Sasa , Stanisavljevic Ivana , Velickovic Dragan , Veljkovic Vlada , Lazic Miodrag
Published: June 2008

This paper presents a comparative study of the anti-oxidant and anti-microbial activities, total phenolic compounds and total flavonoids in extracts obtained from houseleek (Sempervivum marmoreum L.) leaves by the classical (maceration), ultrasonic and Soxhlet extraction (CE, UE and SE, respectively). The extract obtained by the CE contained higher amounts of phenolic and flavonoid compounds and showed a better antioxidant activity than those obtained using other two techniques. All the extracts, independent of the extraction technique applied, showed antimicrobial activities against Aspergillus niger and Candida albicans only but not against the tested bacteria.
Temperature dependence of the kinetics of oxygen reduction on carbon-supported pt nanoparticles
Authors: Elezovic Nevenka , Babic Biljana , Krstajic Nedeljko , Gojkovic Snezana , Vracar Ljiljana
Published: June 2008

The temperature dependence of oxygen reduction reaction (ORR) was studied on highly dispersed Pt nanoparticles supported on a carbon cryo-gel. The specific surface area of the support was 517 m2 g-1, the Pt particles diameter was about 2.7 nm and the loading of the catalyst was 20 wt.%. The kinetics of the ORR at the Pt/C electrode was examined in 0.50 mol dm-3 HClO4 solution in the temperature range from 274 to 318 K. At all temperatures, two distinct E-log j regions were observed; at low current densities with a slope of -2.3RT/F and at high current densities with a slope of -2.3?2RT/F. In order to confirm the mechanism of oxygen reduction previously suggested at a polycrystalline Pt and a Pt/Ebonex nanostructured electrode, the apparent enthalpies of activation at selected potentials vs. the reversible hydrogen electrode were calculated in both current density regions. Although ?H ?a,1 > ?H ?a,h , it was a,1 a, h found that the enthalpies of activation at the zero Galvani potential difference were the same and hence it could be concluded that the rate-determining step of the ORR was the same in both current density regions. The synthesized Pt/C catalyst showed a small enhancement in the catalytic activity for ORR in comparison to the polycrystalline Pt, but no change in the mechanism of the reaction.
Supercapacitive characteristics of electrochemically active porous materials
Authors: Panic Vladimir
Published: June 2008

The results of an investigation of the capacitive characteristics of sol-gel-processed titanium- and carbon-supported electrochemically active noble metal oxides, as representatives of porous electrode materials, are presented in the lecture. The capacitive properties of these materials were correlated to their composition, the preparation conditions of the oxides and coatings, the properties of the carbon support and to the composition of the electrolyte. The results of the electrochemical test methods, cyclic voltammetry and electrochemical impedance spectroscopy, were employed to resolve the possible physical structures of the mentioned porous materials, which are governed by the controlled conditions of the preparation of the oxide by the sol-gel process.
Event-related potentials following exercise bouts of different intensity
Authors: Barak Otto , Ivetic Vesna , Filipovic Danka , Naumovic Nada , Lukac Damir , Drapsin Miodrag , Karaba-Jakovljevic Dea , Popadic-Gacesa Jelena , Klasnja Aleksandar , Grujic Nikola
Published: June 2008

Introduction. A number of articles on physical activity analyze the effects of acute bouts of physical exercise on the whole body. These experiments mainly include questionnaires and measurements of reaction time. The use of event-related potentials in laboratories for functional diagnostics is only of recent date. The aim of this experiment was to give insights into the impact of physical activity of different intensity on the amplitude and latency of P300 cognitive potentials. Material and methods. After recording cognitive event-related potentials in 17 young (21.6?1.07 yrs) healthy adults (at Fz and Cz), the participants underwent a controlled bicycle ergometer exercise. Each exercise lasted 10 minutes, with successive increase in the intensity to 60%, 75% and 90% of the maximum pulse rate and maintaining this level of intensity for six minutes. Immediately after each bout of exercise, event-related potentials were recorded. Results. The amplitude of the P300 wave, following exercise intensity at 75% of the maximum pulse (Pmax) (Fz 15.00?4.57; Cz 18.63?8.83 mV) was statistically higher (p<0.05) than the amplitude of the P300 at rest (Fz 11.21?4.15 mV; Cz 13.40?8.04 mV), at 60% (Fz 11.86?5.11 mV; Cz 14.54?8.06 mV) and at 90% of maximum pulse (Fz 13.26?4.73 mV; Cz 14.91?8.91 mV). There were no statistically significant differences (p>0.05) between amplitudes at 60% of Pmax and values obtained at rest and at 90% of Pmax. Also, no statistically significant differences were recorded (p>0.05) among the latencies of P300 recorded at rest (Fz 323.57?13.24 ms; Cz 323.57?13.24 ms) and at 60% of Pmax (Fz 321.14?22.38 ms; Cz 321.86?22.88 ms), at 75% of Pmax (Fz 321.50?16.67 ms; Cz 322.50?14.60 ms) and at 90% of Pmax (Fz 326.29?7.85 ms; Cz 325.43?7.63 ms). Discusssion and Conclusion. Physical activity has a positive impact on cognitive functions. At intermediate intensities, the amplitude of P300 increases, but at submaximal intensities it decreases to values obtained at rest. However, the latency of P300 did not show a statistically significant change after different intensities of exercise.
The results of cytogenetic analyses in prenatal diagnosis
Authors: Jovanovic-Privrodski Jadranka , Kavecan Ivana , Krstic Aleksandar , Gacina Ljiljana
Published: June 2008

Introduction. G-banding and other classical cytogenetic methods are still in use, together with molecular cytogenetic techniques such as FISH (Fluorescence In Situ Hybridization) and SKY (Spectral Karyotyping). Material and methods. This retrospective study evaluated clinical data on individuaols seeking genetic counseling over a 15-year period (1992 - 2007) at the Medical Genetic Center, Child and Youth Health Care Institute of Vojvodina in Novi Sad. The study included 37.191 genetic counselings, and 20.607 prenatal analyses (amniocentesis and cordocentesis). Results Over a 15-year period (1992 - 2007) 17.937 amniotic fluid samples were analyzed and 274 abnormal karyotypes were found; out of 2.670 fetal blood samples, there were 78 abnormal karyotypes. During a 15-year period, prenatal diagnosis, using amniocentesis and/or cordocentesis, showed 352 fetuses with chromosomal aberrations. Discussion. On average, over the past 15-year period, 8% of pregnancies were controlled with invasive prenatal procedures. The percentage has changed; in fact, it is increasing from year to year. In 1992, only 0.82% (N=139/17000) of pregnant women in Vojvodina underwent invasive prenatal procedures, and in 2006 the rate increased to 15.65% (N=2660/17000). Conclusion. It is necessary to improve and promote the possibilities of genetic counseling and invasive prenatal diagnosis in order to prevent the occurrence of chromosomal aberrations and other genetic diseases.
Cochlear implantation at the ear, nose and throat clinic of the Clinical center of Vojvodina
Authors: Komazec Zoran , Dankuc Dragan , Vlaski Ljiljana , Lemajic-Komazec Slobodanka , Nedeljkov Spomenka , Sokolovac Ivana
Published: June 2008

Introduction. A cochlear implant is a small electronic device that can provide a sense of sound to a person who is profoundly deaf or severely hard-of-hearing. Cochlear implants bypass the damaged hearing systems and directly stimulate the auditory nerve. Signals generated by the implant are sent by way of the auditory nerve to the brain, which recognizes the signals as sound. Hearing through a cochlear implant differs from normal hearing and takes time to learn or relearn. Cochlear implantations have been performed at the ENT Clinic in Novi Sad since 2002. The aim of this retrospective investigation was to evaluate performance of cochlear implanted patients in regard to the age of hearing loss identification, age at implantation, as well as complications. Material and Methods. During a 5-year period (2002-2007), 45 patients underwent cochlear implantation (46 implants) at the ENT Clinic in Novi Sad. Only four patients were postlingually deaf adults. Forty-one implanted patients were children with a mean age at implantation of 42.2 months (range: 2 to 8 years). Out of these patients, 28 (68.2%) had congenital deafness of unknown cause. The commonest known cause was meningitis, found in 4 (9.7%) patients, followed by use of ototoxic drugs and hereditary deafness. Etiological factors included: postnatal hypoxia, intracranial hemorrhage, pre term birth, cytomegalovirus infection during pregnancy, middle ear cholesteatoma, as well as sudden bilateral deafness. The time span between diagnosis of hearing loss and implantation was 34.6 months in 2002 and only 10 months in 2007. Results. 6 (13%) patients presented with complications. There were 4 major, and two minor complications. The following complications were noted: ossified cochlea which required reoperation, unsuccessful operation in a patient with Down syndrome, facial tics, temporary facial weakness and ataxia. Five out of six complications were successfully resolved. Conclusion. New, more sophisticated audiological evaluation is essential to shorten the time for diagnosing hearing impairment. The results of the investigation performed at the Cochlear Implantation Center of the ENT Clinic in Novi Sad show that cochlear implantation is an effective procedure which should be continued.
A computational fluid dynamics analysis on stratified scavenging system of medium capacity two-stroke internal combustion engines
Authors: Pitta Srinivasa , Kuderu Rajagopal
Published: June 2008

The main objective of the present work is to make a computational study of stratified scavenging system in two-stroke medium capacity engines to reduce or to curb the emissions from the two-stroke engines. The 3-D flows within the cylinder are simulated using computational fluid dynamics and the code Fluent 6. Flow structures in the transfer ports and the exhaust port are predicted without the stratification and with the stratification, and are well predicted. The total pressure and velocity map from computation provided comprehensive information on the scavenging and stratification phenomenon. Analysis is carried out for the transfer ports flow and the extra port in the transfer port along with the exhaust port when the piston is moving from the top dead center to the bottom dead center, as the ports are closed, half open, three forth open, and full port opening. An unstructured cell is adopted for meshing the geometry created in CATIA software. Flow is simulated by solving governing equations namely conservation of mass momentum and energy using SIMPLE algorithm. Turbulence is modeled by high Reynolds number version k-e model. Experimental measurements are made for validating the numerical prediction. Good agreement is observed between predicted result and experimental data; that the stratification had significantly reduced the emissions and fuel economy is achieved.
Comparison of different chemical kinetic mechanisms of methane combustion in an internal combustion engine configuration
Authors: Ennetta Ridha , Hamdi Mohamed , Said Rachid
Published: June 2008

Three chemical kinetic mechanisms of methane combustion were tested and compared using the internal combustion engine model of Chemkin 4.02 [1]: one-step global reaction mechanism, four-step mechanism, and the standard detailed scheme GRIMECH 3.0. This study shows good concordances, especially between the four-step and the detailed mechanisms in the prediction of temperature and main species profiles. But reduced schemes were incapables to predict pollutant emissions in an internal combustion engine. The four-step mechanism can only predict CO emissions but without good agreement.
A quick, simplified approach to the evaluation of combustion rate from an internal combustion engine indicator diagram
Authors: Tomic Miroljub , Popovic Slobodan , Miljic Nenad , Petrovic Stojan , Cvetic Milos , Knezevic Dragan , Jovanovic Zoran
Published: June 2008

In this paper a simplified procedure of an internal combustion engine in-cylinder pressure record analysis has been presented. The method is very easy for programming and provides quick evaluation of the gas temperature and the rate of combustion. It is based on the consideration proposed by Hohenberg and Killman, but enhances the approach by involving the rate of heat transferred to the walls that was omitted in the original approach. It enables the evaluation of the complete rate of heat released by combustion (often designated as ?gross heat release rate? or ?fuel chemical energy release rate?), not only the rate of heat transferred to the gas (which is often designated as ?net heat release rate?). The accuracy of the method has been also analyzed and it is shown that the errors caused by the simplifications in the model are very small, particularly if the crank angle step is also small. A several practical applications on recorded pressure diagrams taken from both spark ignition and compression ignition engine are presented as well.
Combustion and emission characteristics of a dual fuel engine operated with mahua oil and liquefied petroleum gas
Authors: Nadar Kapilan , Reddy Rana
Published: June 2008

For the present work, a single cylinder diesel engine was modified to work in dual fuel mode. To study the feasibility of using methyl ester of mahua oil as pilot fuel, it was used as pilot fuel and liquefied petroleum gas was used as primary fuel. In dual fuel mode, pilot fuel quantity and injector opening pressure are the few variables, which affect the performance and emission of dual fuel engine. Hence, in the present work, pilot fuel quantity and injector opening pressure were varied. From the test results, it was observed that the pilot fuel quantity of 5 mg per cycle and injector opening pressure of 200 bar results in higher brake thermal efficiency. Also the exhaust emissions such as smoke, unburnt hydrocarbon and carbon monoxide are lower than other pressures and pilot fuel quantities. The higher injection pressure and proper pilot fuel quantity might have resulted in better atomization, penetration of methyl ester of mahua oil and better combustion of fuel.
Loss of Parenting Self-Efficacy among Immigrant Parents
Authors: Ali Mehrunnisa Ahmad
Published: June 2008

The early settlement experiences of immigrant parents of young children arriving in Canada make it difficult for them to meet their young children's physiological, social and emotional needs, or to help them navigate the structures of their new environment. They lose their sense of self-efficacy in their parenting role in the face of rapid reduction in their social, emotional, cultural and financial resources. This loss of parenting self-efficacy is a consequence of systemic constraints on their ability to exercise agency in raising their children and, unless disrupted, it will perpetuate inequitable and unjust relations among racialized and white populations in Canada.
The New Workforce Generation: Understanding the Problems Facing Parental Involvement in Jordanian Kindergartens
Authors: Ihmeideh Fathi , Khasawneh Samer , Mahfouz Safi , Khawaldeh Moustafa
Published: June 2008

This study aimed to investigate the problems facing parental involvement in Jordanian kindergartens from the parents' perspectives. A 36-item questionnaire that addressed five domains was designed by the researchers and distributed among the study participants. The study sample consisted of 297 parents of kindergarten children from various kindergartens in Amman. The results reveal that the main problem facing parental involvement was related to the kindergarten principals, followed by problems related to the kindergarten teachers, while the kindergarten facilities were the least serious problem. Also, the results indicate that there were statistically significant differences only with problems related to the kindergarten instructional program domain with regard to the parents' gender, while there were no differences attributed to the educational and economic levels of the parents. Based on these findings the researchers address a number of suggestions and recommendations for enhancing parental involvement in Jordanian kindergartens.
Cholinergic Regulation of Ghrelin and Peptide YY Release May Be Impaired in Obesity
Authors: Maier Christina , Riedl Michaela , Vila Greisa , Nowotny Peter , Wolzt Michael , Clodi Martin , Ludvik Bernhard , Luger Anton
Published: June 2008

OBJECTIVE—Ghrelin and peptide YY (PYY) are both hormones derived from the gastrointestinal tract involved in appetite regulation. The cholinergic part of the vagal nerve is involved in the regulation of glucose and insulin. The aim of this study was to examine the effects of the cholinergic antagonist atropine on ghrelin, PYY, glucose, and insulin under basal conditions and after meal ingestion in lean and obese subjects.

REASEARCH DESIGN AND METHODS—Eight lean and eight obese subjects were included in a randomized, double-blind, placebo-controlled crossover study with 4 study days in randomized order (atropine/placebo ± breakfast). Plasma ghrelin, PYY, insulin, and glucose were measured. Hunger and satiety feelings were rated on a 10-cm visual analog scale.

RESULTS—In lean individuals, atropine led to a decrease in ghrelin concentrations comparable and nonadditive with breakfast ingestion and a significant decrease in both basal and meal-induced PYY concentrations. In obese subjects, atropine did not significantly change ghrelin or PYY concentrations, whereas it induced a comparable increase in heart rate and meal-induced glucose concentrations in the two study groups. Only lean, not obese, subjects experienced sustained feelings of satiety after breakfast.

CONCLUSIONS—The impaired cholinergic regulation of the postprandial drop in ghrelin concentrations and rise in PYY concentrations might be part of the deregulated food intake in obese subjects.
Association Testing of Novel Type 2 Diabetes Risk Alleles in the JAZF1, CDC123/CAMK1D, TSPAN8, THADA, ADAMTS9, and NOTCH2 Loci With Insulin Release, Insulin Sensitivity, and Obesity in a Population-Based Sample of 4,516 Glucose-Tolerant Middle-Aged Danes
Authors: Grarup Niels , Andersen Gitte , Krarup Nikolaj T. , Albrechtsen Anders , Schmitz Ole , Jørgensen Torben , Borch-Johnsen Knut , Hansen Torben , Pedersen Oluf
Published: June 2008

OBJECTIVE— We evaluated the impact on diabetes-related intermediary traits of common novel type 2 diabetes–associated variants in the JAZF1 (rs864745), CDC123/CAMK1D (rs12779790), TSPAN8 (rs7961581), THADA (rs7578597), ADAMTS9 (rs4607103), and NOTCH2 (rs10923931) loci, which were recently identified by meta-analysis of genome-wide association data.

RESEARCH DESIGN AND METHODS— We genotyped the six variants in 4,516 middle-aged glucose-tolerant individuals of the population-based Inter99 cohort who were all characterized by an oral glucose tolerance test (OGTT).

RESULTS— Homozygous carriers of the minor diabetes risk G-allele of the CDC123/CAMK1D rs12779790 showed an 18% decrease in insulinogenic index (95% CI 10–27%; P = 4 × 10−5), an 18% decrease in corrected insulin response (CIR) (8.1–29%; P = 4 × 10−4), and a 13% decrease in the ratio of area under the serum-insulin and plasma-glucose curves during an OGTT (AUC-insulin/AUC-glucose) (5.8–20%; P = 4 × 10−4). Carriers of the diabetes-associated T-allele of JAZF1 rs864745 had an allele-dependent 3% decrease in BIGTT-AIR (0.9–4.3%; P = 0.003). Furthermore, the diabetes-associated C-allele of TSPAN8 rs7961581 associated with decreased levels of CIR (4.5% [0.5–8.4]; P = 0.03), of AUC-insulin/AUC-glucose ratio (3.9% [1.2–6.7]; P = 0.005), and of the insulinogenic index (5.2% [1.9–8.6]; P = 0.002). No association with traits of insulin release or insulin action was observed for the THADA, ADAMTS9, or NOTCH2 variants.

CONCLUSIONS— If replicated, our data suggest that type 2 diabetes at-risk alleles in the JAZF1, CDC123/CAMK1D, and TSPAN8 loci associate with various OGTT-based surrogate measures of insulin release, emphasizing the contribution of abnormal pancreatic β-cell function in the pathogenesis of type 2 diabetes.
Increase in Endoplasmic Reticulum Stress–Related Proteins and Genes in Adipose Tissue of Obese, Insulin-Resistant Individuals
Authors: Boden Guenther , Duan Xunbao , Homko Carol , Molina Ezequiel J. , Song WeiWei , Perez Oscar , Cheung Peter , Merali Salim
Published: June 2008

OBJECTIVE—To examine fat biopsy samples from lean insulin-sensitive and obese insulin-resistant nondiabetic individuals for evidence of endoplasmic reticulum (ER) stress.

RESEARCH DESIGN AND METHODS—Subcutaneous fat biopsies were obtained from the upper thighs of six lean and six obese nondiabetic subjects. Fat homogenates were used for proteomic (two-dimensional gel and MALDI-TOF/TOF), Western blot, and RT-PCR analysis.

RESULTS—Proteomic analysis revealed 19 differentially upregulated proteins in fat of obese subjects. Three of these proteins were the ER stress–related unfolded protein response (UPR) proteins calreticulin, protein disulfide-isomerase A3, and glutathione-S-transferase P. Western blotting revealed upregulation of several other UPR stress–related proteins, including calnexin, a membrane-bound chaperone, and phospho c-jun NH2-terminal kinase (JNK)-1, a downstream effector protein of ER stress. RT-PCR analysis revealed upregulation of the spliced form of X-box binding protein-1s, a potent transcription factor and part of the proximal ER stress sensor inositol-requiring enzyme-1 pathway.

CONCLUSIONS—These findings represent the first demonstration of UPR activation in subcutaneous adipose tissue of obese human subjects. As JNK can inhibit insulin action and activate proinflammatory pathways, ER stress activation of JNK may be a link between obesity, insulin resistance, and inflammation.
Sustained Weight Loss Following 12-Month Pramlintide Treatment as an Adjunct to Lifestyle Intervention in Obesity
Authors: Smith Steve R. , Aronne Louis J. , Burns Colleen M. , Kesty Nicole C. , Halseth Amy E. , Weyer Christian
Published: June 2008

OBJECTIVE—To assess long-term weight loss efficacy and safety of pramlintide used at different dosing regimens and in conjunction with lifestyle intervention (LSI).

RESEARCH DESIGN AND METHODS—In a 4-month, double-blind, placebo-controlled, dose-ranging study, 411 obese subjects were randomized to receive pramlintide (six arms: 120, 240, and 360 μg b.i.d. and t.i.d.) or placebo in conjunction with a structured LSI program geared toward weight loss. Of the 4-month evaluable subjects (n = 270), 77% opted to continue preexisting treatment during an 8-month single-blind extension (LSI geared toward weight maintenance).

RESULTS—At month 4, mean weight loss from baseline in the pramlintide arms ranged from 3.8 ± 0.7 to 6.1 ± 0.8 kg (2.8 ± 0.8 kg with placebo). By month 12, initial 4-month weight loss was regained in the placebo group but was maintained in all but the 120-μg b.i.d. group. Placebo-corrected weight loss with 120 μg t.i.d. and 360 μg b.i.d. averaged 3.2 ± 1.2 kg (3.1 ± 1.1% body wt) and 3.3 ± 1.1 kg (3.1 ± 1.0% body wt), respectively, at month 4 (both P < 0.01; 4-month evaluable n = 270) and 6.1 ± 2.1 kg (5.6 ± 2.1% body wt) and 7.2 ± 2.3 kg (6.8 ± 2.3% body wt), respectively, at month 12 (both P < 0.01; 12-month evaluable n = 146). At month 12, 40 and 43% of subjects treated with 120 μg t.i.d. and 360 μg b.i.d., respectively, achieved ≥10% weight loss (vs. 12% for placebo). Nausea, the most common adverse event with pramlintide in the 4-month study (9–29% pramlintide vs. 2% placebo), was generally mild to moderate and occurred in <10% of subjects during the extension.

CONCLUSIONS—When used over 12 months as an adjunct to LSI, pramlintide treatment, with low-dose three-times-daily or higher-dose two-times-daily regimens, helped obese subjects achieve greater initial weight loss and enhanced long-term maintenance of weight loss.
Weight Change in Diabetes and Glycemic and Blood Pressure Control
Authors: Feldstein Adrianne C. , Nichols Gregory A. , Smith David H. , Stevens Victor J. , Bachman Keith , Rosales A. Gabriela , Perrin Nancy
Published: June 2008

OBJECTIVE—Weight loss in type 2 diabetes is undisputedly important, and data from community settings are limited. We evaluated weight change and resulting glycemic and blood pressure control in type 2 diabetic patients at an HMO.

RESEARCH DESIGN AND METHODS—Using electronic medical records, this retrospective cohort study identified 2,574 patients aged 21–75 years who received a new diagnosis of type 2 diabetes between 1997 and 2002. We estimated 3-year weight trajectories using growth curve analyses, grouped similar trajectories into four categories using cluster analysis, compared category characteristics, and predicted year-4 above-goal A1C and blood pressure by group.

RESULTS—The weight-trajectory groups were defined as higher stable weight (n = 418; 16.2%), lower stable weight (n = 1,542; 59.9%), weight gain (n = 300; 11.7%), and weight loss (n = 314; 12.2%). The latter had a mean weight loss of 10.7 kg (−9.8%; P < 0.001) by 18 months, with near-complete regain by 36 months. After adjusting for age, sex, baseline control, and related medication use, those with higher stable weight, lower stable weight, or weight-gain patterns were more likely than those who lost weight to have above-goal A1C (odds ratio [OR] 1.66 [95% CI 1.12–2.47], 1.52 [1.08–2.14], and 1.77 [1.15–2.72], respectively). Those with higher stable weight or weight-gain patterns were more likely than those who lost weight to have above-goal blood pressure (1.83 [1.31–2.57] and 1.47 [1.03–2.10], respectively).

CONCLUSIONS—A weight-loss pattern after new diagnosis of type 2 diabetes predicted improved glycemic and blood pressure control despite weight regain. The initial period postdiagnosis may be a critical time to apply weight-loss treatments to improve risk factor control.
Isospora cagasebi sp. nov. (Apicomplexa, Eimeriidae) from the bananaquit, Coereba flaveola of Brazil
Authors: Berto Bruno , Flausino Walter , Luz Hermes , Ferreira Ildemar , Lopes Carlos
Published: June 2008

Isospora cagasebi sp. nov. (Apicomplexa, Eimeriidae) is reported from a bananaquit, Coereba flaveola from Brazil. Oocysts are sub-spherical, 24.9 × 24.5 (23.0–26.1 × 22.6–25.4), with a smooth, bilayered wall ∼1.4 and mean L:W ratio 1.0; micropyle, oocyst residuum and polar granule are absent. Sporocysts are elongate ovoidal, 18.7 × 11.5 (17.6–19.4 × 10.4–12.3), with both Stieda and substieda bodies and mean L:W ratio 1.6; sporocyst residuum present and sporozoites each with 2 refractiles bodies.
Dioecy and monoecy in the flora of Sri Lanka and their evolutionary correlations to endemism, growth form, fruit type, seed number and flower size
Authors: Senarath W.T.P.S.K.
Published: June 2008

The frequency of dioecy and monoecy and the ecological correlates of each sexual system were examined for the flora of Sri Lanka, a tropical continental island. Of the 3,529 species in the total flora, 7.05% are dioecious, 10.25% are monoecious, 1.7% are polygamodioecious, 1.9% are polygamous and 79.1% are hermaphrodites. Study was carried out to test the null hypothesis that the proportionate distribution of dioecious and monoecious taxa in endemism, growth form, fruit type, seed number or flower size was not significantly different from that for the entire flora. Both monoecious and dioecious species in the Sri Lankan flora are significantly associated with the growth form, fruit type, seed number and flower size, whereas only dioecy is associated with endemism. Dioecious species are favored by trees and small flowers, whereas monoecious species are favored by herbs and minute flowers. Both dioecious and monoecious species are, however, associated with fleshy fruits suggesting that animal dispersal of fruits is favored in the Sri Lankan flora. Keywords: Flora, Evolutionary correlations, Dioecy, Monoecy, Sri LankaDOI: 10.3329/bjpt.v15i1.907Bangladesh J. Plant Taxon. 15(1): 13-19, 2008 (June)
New records of phytoplankton for Bangladesh. 5. Euglena, Euglenocapsa
Authors: Khondker Moniruzzaman , Bhuiyan Rauf Ahmed , Yeasmin Jenat , Alam Munirul , Sack R. Bradley , Huq Anwar , Colwell Rita R.
Published: June 2008

This study presents 20 taxa of the genus Euglena and one species of the rare euglenoid genus Euglenocapsa. All these taxa are reported for the first time from some pond ecosystems of Mathbaria in Pirojpur and Bakerganj of Barisal districts of Bangladesh. Keywords: Phytoplankton, New records, Bangladesh, Euglena, Euglenocapsa, PondsDOI: 10.3329/bjpt.v15i1.910Bangladesh J. Plant Taxon. 15(1): 39-46, 2008 (June)
Structure and composition of understory plant assemblages of six land use types in the Lore Lindu National Park, Central Sulawesi, Indonesia
Authors: Ramadhanil Ramadhanil , Tjitrosoedirdjo Sri Soetarmi , Setiadi Dede
Published: June 2008

In the present study the diversity and species composition of understory plants are examined in the submontane forest of Lore Lindu National Park, Central Sulawesi, Indonesia by comparing three rain forest types and three types of plantations of cacao differing in use intensity. The results showed that 376 understory plant species consisting of 140 species of tree seedlings, 162 herbs and shrubs, 29 terrestrial ferns and 45 climbers were collected in all land use types. The mean species numbers of herbs did not differ among three forest types but was significantly higher in cacao plantation with high use intensity, being about three times higher than in undisturbed rain forest and lightly disturbed rain forest. Urticaceae, Araceae, Hypoxidaceae and Acanthaceae were predominant in the forests, whereas Asteraceae and Poaceae in the cacao plantations. The number of species of ferns and climbers did not differ between forests and plantations. The study also recorded several invasive plant species at the cacao plantations such as Piper aduncum L., Bidens pilosa L., Ageratum conyzoides L., Sclerea purpuriens Steud and Paspalum conjugatum Berg.Keywords: Cacao plantation, Primary forest, Structure and Composition, Understory plant assemblagesDOI: 10.3329/bjpt.v15i1.911 Bangladesh J. Plant Taxon. 15(1): 1-12, 2008 (June)
MicroRNA: an Emerging Therapeutic Target and Intervention Tool
Authors: Liu Zhen , Sall Alhousseynou , Yang Decheng
Published: June 2008

MicroRNAs (miRNAs) are a class of short non-coding RNAs with posttranscriptional regulatory functions. To date, more than 600 human miRNAs have been experimentally identified, and estimated to regulate more than one third of cellular messenger RNAs. Accumulating evidence has linked the dysregulated expression patterns of miRNAs to a variety of diseases, such as cancer, neurodegenerative diseases, cardiovascular diseases and viral infections. MiRNAs provide its particular layer of network for gene regulation, thus possessing the great potential both as a novel class of therapeutic targets and as a powerful intervention tool. In this regard, synthetic RNAs that contain the binding sites of miRNA have been shown to work as a “decoy” or “miRNA sponge” to inhibit the function of specific miRNAs. On the other hand, miRNA expression vectors have been used to restore or overexpress specific miRNAs to achieve a long-term effect. Further, double-stranded miRNA mimetics for transient replacement have been experimentally validated. Endogenous precursor miRNAs have also been used as scaffolds for the induction of RNA interference. This article reviews the recent progress on this emerging technology as a powerful tool for gene regulation studies and particularly as a rationale strategy for design of therapeutics.
Neural network‐based adaptive control of piezoelectric actuators with unknown hysteresis
Authors: Xie Wen‐Fang , Fu Jun , Yao Han , Su C.‐Y.
Published: June 2008

This paper proposes a neural network (NN)‐based adaptive control of piezoelectric actuators with unknown hysteresis. Based on the classical Duhem model described by a differential equation, the explicit solution to the equation is explored and a new hysteresis model is constructed as a linear model in series with a piecewise continuous nonlinear function. An NN‐based dynamic pre‐inversion compensator is designed to cancel out the effect of the hysteresis. With the incorporation of the pre‐inversion compensator, an adaptive control scheme is proposed to have the position of the piezoelectric actuator track the desired trajectory. This paper has three distinct features. First, it applies the NN to online approximate complicated piecewise continuous unknown nonlinear functions in the explicit solution to Duhem model. Second, an observer is designed to estimate the output of hysteresis of piezoelectric actuator based on the system input and output. Third, the stability of the controlled piezoelectric actuator with the observer is guaranteed. Simulation results for a practical system validate the effectiveness of the proposed method in this paper. Copyright © 2008 John Wiley & Sons, Ltd.
Adaptive observers for linear stochastic time‐variant systems with disturbances
Authors: Perabò Stefano , Zhang Qinghua
Published: June 2008

Motivated by fault detection and isolation problems, we present an approach to the design of state observers for linear time‐variant stochastic systems with unknown parameters and disturbances. The novelties with respect to more conventional techniques are as follows: (a) the joint estimation of state, disturbances and parameters can be carried out; (b) it is a full‐stochastic approach: the unknown parameters and disturbances are random quantities and prior information, in terms of means and covariances, can be easily taken into account; (c) the observer structure is not fixed a priori, rather derived from the optimal one by means of a sliding window approximation; (d) contrary to descriptor system techniques, which estimate the state starting from a restricted set of disturbance‐free equations, our approach is focused on disturbance estimation, from which state estimates are derived straightforwardly. Copyright © 2008 John Wiley & Sons, Ltd.
Adaptive TS‐FNN control for a class of uncertain multi‐time‐delay systems: The exponentially stable sliding mode‐based approach
Authors: Chiang Tung‐Sheng , Chiu Chian‐Song , Liu Peter
Published: June 2008

This paper presents an adaptive Takagi–Sugeno fuzzy neural network (TS‐FNN) control for a class of multiple time‐delay uncertain nonlinear systems. First, we develop a sliding surface guaranteed to achieve exponential stability while considering mismatched uncertainty and unknown delays. This exponential stability result based on a novel Lyapunov–Krasovskii method is an improvement when compared with traditional schemes where only asymptotic stability is achieved. The stability analysis is transformed into a linear matrix inequalities problem independent of time delays. Then, a sliding mode control‐based TS‐FNN control scheme is proposed to achieve asymptotic stability for the controlled system. Since the TS‐FNN combines TS fuzzy rules and a neural network structure, fewer numbers of fuzzy rules and tuning parameters are used compared with the traditional pure TS fuzzy approach. Moreover, all the fuzzy membership functions are tuned on‐line even in the presence of input uncertainty. Finally, simulation results show the control performance of the proposed scheme. Copyright © 2008 John Wiley & Sons, Ltd.
Parametric study and estimation in CFD‐based PEM fuel cell models
Authors: Jain Parag , Biegler Lorenz T. , Jhon Myung S.
Published: June 2008

We propose an integrated modeling and optimization framework including detailed computational fluid dynamics based models and polymer electrolyte membrane fuel cell (PEMFC) systems. As an illustration, a multidimensional, multiphysics PEMFC model is constructed that accounts for major transport processes in the gas channels and the membrane electrode assembly. The resulting system of highly nonlinear partial differential‐algebraic equations is fully discretized using a finite volume method, and the resulting large‐scale nonlinear program is linked to a state‐of‐the‐art interior point optimization algorithm. The framework is used for solving challenging parameter estimation problems resulting from incorporation of multiple experimental data points. Also, parametric studies are performed on detailed water transport mechanisms and distribution characteristics, and on overall system performance. Our proposed framework provides a robust and fast solution methodology, and is planned for modeling extensions and addressing other critical issues in PEMFC technology that require large‐scale simulations. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Diameter‐dependent dispersion in cylindrical bead packs
Authors: Vandre Eric , Maier Robert S. , Kroll Daniel M. , McCormick Alon , Davis H. Ted
Published: June 2008

It has recently been argued that longitudinal dispersion in cylindrical packed beds is enhanced due to radial heterogeneities in the porosity and resulting velocity field. In particular, it is predicted that the time scale to attain asymptotic dispersion in a packed bed of radius R is proportional to R2/DT, where DT is the transverse dispersion constant in a homogeneous beadpack, and that the asymptotic longitudinal dispersion constant increases with R/d, where d is the bead diameter. We have measured the asymptotic dispersion rates for packed beds with R/d = 9.5, 12.7, and 25.4 and find good qualitative agreement with the predicted dependence on R/d. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Simple approximate analytical solution for nonisothermal single‐step transformations: Kinetic analysis
Authors: Farjas J. , Roura P.
Published: June 2008

We develop a method for obtaining the approximate solution for the evolution of single‐step transformations under nonisothermal conditions. We have applied it to many reaction models and obtained very simple analytical expressions for the shape of the corresponding transformation rate peaks. These analytical solutions represent a significant simplification of the system's description allowing easy curve fitting to experiment. A remarkable property is that the evolutions of the transformed fraction obtained at different heating rates are identical when time is scaled by a time constant. The accuracy achieved with our method is checked against several reaction models and different temperature dependencies of the transformation rate constant. It is shown that its accuracy is closely related with that of the Kissinger method. © 2008 American Institute of Chemical Engineers AIChE J, 2008