bluuebunny/crossref_metadata_2025 huggingface dataset:
Multilocus genetics to reconstruct aeromonad evolution
Authors: Roger Frédéric , Marchandin Hélène , Jumas-Bilak Estelle , Kodjo Angeli ,   the colBVH study group, Lamy Brigitte
Published: April 2012

Background

Aeromonas spp. are versatile bacteria that exhibit a wide variety of lifestyles. In an attempt to improve the understanding of human aeromonosis, we investigated whether clinical isolates displayed specific characteristics in terms of genetic diversity, population structure and mode of evolution among Aeromonas spp. A collection of 195 Aeromonas isolates from human, animal and environmental sources was therefore genotyped using multilocus sequence analysis (MLSA) based on the dnaK, gltA, gyrB, radA, rpoB, tsf and zipA genes.

Results

The MLSA showed a high level of genetic diversity among the population, and multilocus-based phylogenetic analysis (MLPA) revealed 3 major clades: the A. veronii, A. hydrophila and A. caviae clades, among the eleven clades detected. Lower genetic diversity was observed within the A. caviae clade as well as among clinical isolates compared to environmental isolates. Clonal complexes, each of which included a limited number of strains, mainly corresponded to host-associated subsclusters of strains, i.e., a fish-associated subset within A. salmonicida and 11 human-associated subsets, 9 of which included only disease-associated strains. The population structure was shown to be clonal, with modes of evolution that involved mutations in general and recombination events locally. Recombination was detected in 5 genes in the MLSA scheme and concerned approximately 50% of the STs. Therefore, these recombination events could explain the observed phylogenetic incongruities and low robustness. However, the MLPA globally confirmed the current systematics of the genus Aeromonas.

Conclusions

Evolution in the genus Aeromonas has resulted in exceptionally high genetic diversity. Emerging from this diversity, subsets of strains appeared to be host adapted and/or “disease specialized” while the A. caviae clade displayed an atypical tempo of evolution among aeromonads. Considering that A. salmonicida has been described as a genetically uniform pathogen that has adapted to fish through evolution from a variable ancestral population, we hypothesize that the population structure of aeromonads described herein suggested an ongoing process of adaptation to specialized niches associated with different degrees of advancement according to clades and clusters.
Spatial and temporal dynamics of malaria transmission in rural Western Kenya
Authors: Amek Nyaguara , Bayoh Nabie , Hamel Mary , Lindblade Kim A , Gimnig John E , Odhiambo Frank , Laserson Kayla F , Slutsker Laurence , Smith Thomas , Vounatsou Penelope
Published: April 2012

Background

Understanding the relationship betweenPlasmodium falciparummalaria transmission and health outcomes requires accurate estimates of exposure to infectious mosquitoes. However, measures of exposure such as mosquito density and entomological inoculation rate (EIR) are generally aggregated over large areas and time periods, biasing the outcome-exposure relationship. There are few studies examining the extent and drivers of local variation in malaria exposure in endemic areas.

Methods

We describe the spatio-temporal dynamics of malaria transmission intensity measured by mosquito density and EIR in the KEMRI/CDC health and demographic surveillance system using entomological data collected during 2002–2004. Geostatistical zero inflated binomial and negative binomial models were applied to obtain location specific (house) estimates of sporozoite rates and mosquito densities respectively. Model-based predictions were multiplied to estimate the spatial pattern of annual entomological inoculation rate, a measure of the number of infective bites a person receive per unit of time. The models included environmental and climatic predictors extracted from satellite data, harmonic seasonal trends and parameters describing space-time correlation.

Results

Anopheles gambiaes.l was the main vector species accounting for 86 % (n = 2309) of the total mosquitoes collected with the remainder beingAnopheles funestus. Sixty eight percent (757/1110) of the surveyed houses had no mosquitoes. Distance to water bodies, vegetation and day temperature were strongly associated with mosquito density. Overall annual point estimates of EIR were 6.7, 9.3 and 9.6 infectious bites per annum for 2002, 2003 and 2004 respectively. Monthly mosquito density and EIR varied over the study period peaking in May during the wet season each year. The predicted and observed densities of mosquitoes and EIR showed a strong seasonal and spatial pattern over the study area.

Conclusions

Spatio-temporal maps of malaria transmission intensity obtained in this study are not only useful in understanding variability in malaria epidemiology over small areas but also provide a high resolution exposure surface that can be used to analyse the impact of transmission on malaria related and all-cause morbidity and mortality.
Bias in effect size of systemic lupus erythematosus susceptibility loci across Europe: a case-control study
Authors: Alonso-Perez Elisa , Suarez-Gestal Marian , Calaza Manuel , Sebastiani Gian Domenico , Pullmann Rudolf , Papasteriades Chryssa , Kovacs Attila , Skopouli Fotini N , Bijl Marc , Suarez Ana , Marchini Maurizio , Migliaresi Sergio , Carreira Patricia , Ordi-Ros Josep , Witte Torsten , Ruzickova Sarka , Santos Maria Jose , Barizzone Nadia , Blanco Francisco J , Lauwerys Bernard R , Gomez-Reino Juan J , Gonzalez Antonio ,   the European Consortium of SLE DNA Collections
Published: April 2012

Introduction

We aimed to investigate whether the effect size of the systemic lupus erythematosus (SLE) risk alleles varies across European subpopulations.

Methods

European SLE patients (n = 1,742) and ethnically matched healthy controls (n = 2,101) were recruited at 17 centres from 10 different countries. Only individuals with self-reported ancestry from the country of origin were included. In addition, participants were genotyped for top ancestry informative markers and for 25 SLE associated SNPs. The results were used to compare effect sizes between the Central Eureopan and Southern European subgroups.

Results

Twenty of the 25 SNPs showed independent association with SLE, These SNPs showed a significant bias to larger effect sizes in the Southern subgroup, with 15/20 showing this trend (P = 0.019) and a larger mean odds ratio of the 20 SNPs (1.46 vs. 1.34, P = 0.02) as well as a larger difference in the number of risk alleles (2.06 vs. 1.63, P = 0.027) between SLE patients and controls than for Central Europeans. This bias was reflected in a very significant difference in the cumulative genetic risk score (4.31 vs. 3.48, P = 1.8 × 10-32). Effect size bias was accompanied by a lower number of SLE risk alleles in the Southern subjects, both patients and controls, the difference being more marked between the controls (P = 1.1 × 10-8) than between the Southern and Central European patients (P = 0.016). Seven of these SNPs showed significant allele frequency clines.

Conclusion

Our findings showed a bias to larger effect sizes of SLE loci in the Southern Europeans relative to the Central Europeans together with clines of SLE risk allele frequencies. These results indicate the need to study risk allele clines and the implications of the polygenic model of inheritance in SLE.
Anti-MJ/NXP-2 autoantibody specificity in a cohort of adult Italian patients with polymyositis/dermatomyositis
Authors: Ceribelli Angela , Fredi Micaela , Taraborelli Mara , Cavazzana Ilaria , Franceschini Franco , Quinzanini Marzia , Tincani Angela , Ross Steven J , Chan Jason YF , Pauley Brad A , Chan Edward KL , Satoh Minoru
Published: April 2012

Introduction

Autoantibodies in patients with polymyositis/dermatomyositis (PM/DM) are associated with unique subsets, clinical course and outcome. Anti-MJ antibodies, which recognize the nuclear protein NXP-2/MORC3, are reported in ~25% of juvenile DM. Prevalence and clinical significance of anti-MJ antibodies in adult Italian PM/DM patients were studied.

Methods

Sera from 58 consecutive adult Italian PM/DM patients were analyzed by immunoprecipitation of 35S-labeled K562 cells extract, ELISA (anti-MJ, Jo-1), Western blot and indirect immunofluorescence. Clinical associations were analyzed using information from medical charts.

Results

Anti-MJ antibodies were the most prevalent specificity (17%) found mainly in DM (30%, 8 cases) vs 8% of PM (2 cases, P = 0.02). Comparing 10 anti-MJ (+) vs 48 anti-MJ (-) cases, DM was more common (P = 0.03), and age at onset was younger in anti-MJ (+) (P = 0.0006). In anti-MJ (+), heliotrope rash (P = 0.01) and calcinosis (P = 0.09) were more frequent. None of them had heart or lung involvement, or malignancy. Myopathy in anti-MJ (+) patients responded well to therapy and none of them had elevated CPK at last visit (0% vs 25% in anti-MJ (-)). Only 60% of anti-MJ (+) showed immunofluorescent nuclear dots staining, despite PML localization of NXP-2/MORC3.

Conclusions

Anti-MJ antibodies are the most frequent specificity in our cohort of adult Italian PM/DM. Anti-MJ (+) were associated with young onset DM, calcinosis, no internal organ involvement and good response of myopathy to therapy. Anti-MJ reported in juvenile DM is also found in adult PM/DM, and could be a new useful biomarker.
The effect of three years of TNF alpha blocking therapy on markers of bone turnover and their predictive value for treatment discontinuation in patients with ankylosing spondylitis: a prospective longitudinal observational cohort study
Authors: Arends Suzanne , Spoorenberg Anneke , Houtman Pieternella M , Leijsma Martha K , Bos Reinhard , Kallenberg Cees GM , Groen Henk , Brouwer Elisabeth , van der Veer Eveline
Published: April 2012

Introduction

The aim of this study was to investigate the effect of three years of tumor necrosis factor-alpha (TNF-α) blocking therapy on bone turnover as well as to analyze the predictive value of early changes in bone turnover markers (BTM) for treatment discontinuation in patients with ankylosing spondylitis (AS).

Methods

This is a prospective cohort study of 111 consecutive AS outpatients who started TNF-α blocking therapy. Clinical assessments and BTM were assessed at baseline, three and six months, as well as at one, two, and three years. Z-scores of BTM were calculated to correct for age and gender. Bone mineral density (BMD) was assessed yearly.

Results

After three years, 72 patients (65%) were still using their first TNF-α blocking agent. In these patients, TNF-α blocking therapy resulted in significantly increased bone-specific alkaline phosphatase, a marker of bone formation; decreased serum collagen-telopeptide (sCTX), a marker of bone resorption; and increased lumbar spine and hip BMD compared to baseline. Baseline to three months decrease in sCTX Z-score (HR: 0.394, 95% CI: 0.263 to 0.591), AS disease activity score (ASDAS; HR: 0.488, 95% CI: 0.317 to 0.752), and physician's global disease activity (HR: 0.739, 95% CI: 0.600 to 0.909) were independent inversely related predictors of time to treatment discontinuation because of inefficacy or intolerance. Early decrease in sCTX Z-score correlated significantly with good long-term response regarding disease activity, physical function and quality of life.

Conclusions

Three years of TNF-α blocking therapy results in a bone turnover balance that favors bone formation, especially mineralization, in combination with continuous improvement of lumbar spine BMD. Early change in sCTX can serve as an objective measure in the evaluation of TNF-α blocking therapy in AS, in addition to the currently used more subjective measures.
Nebulized anticoagulants for acute lung injury - a systematic review of preclinical and clinical investigations
Authors: Tuinman Pieter R , Dixon Barry , Levi Marcel , Juffermans Nicole P , Schultz Marcus J
Published: April 2012

Background

Data from interventional trials of systemic anticoagulation for sepsis inconsistently suggest beneficial effects in case of acute lung injury (ALI). Severe systemic bleeding due to anticoagulation may have offset the possible positive effects. Nebulization of anticoagulants may allow for improved local biological availability and as such may improve efficacy in the lungs and lower the risk of systemic bleeding complications.

Method

We performed a systematic review of preclinical studies and clinical trials investigating the efficacy and safety of nebulized anticoagulants in the setting of lung injury in animals and ALI in humans.

Results

The efficacy of nebulized activated protein C, antithrombin, heparin and danaparoid has been tested in diverse animal models of direct (for example, pneumonia-, intra-pulmonary lipopolysaccharide (LPS)-, and smoke inhalation-induced lung injury) and indirect lung injury (for example, intravenous LPS- and trauma-induced lung injury). Nebulized anticoagulants were found to have the potential to attenuate pulmonary coagulopathy and frequently also inflammation. Notably, nebulized danaparoid and heparin but not activated protein C and antithrombin, were found to have an effect on systemic coagulation. Clinical trials of nebulized anticoagulants are very limited. Nebulized heparin was found to improve survival of patients with smoke inhalation-induced ALI. In a trial of critically ill patients who needed mechanical ventilation for longer than two days, nebulized heparin was associated with a higher number of ventilator-free days. In line with results from preclinical studies, nebulization of heparin was found to have an effect on systemic coagulation, but without causing systemic bleedings.

Conclusion

Local anticoagulant therapy through nebulization of anticoagulants attenuates pulmonary coagulopathy and frequently also inflammation in preclinical studies of lung injury. Recent human trials suggest nebulized heparin for ALI to be beneficial and safe, but data are very limited.
Metabolomic analysis of rat serum in streptozotocin-induced diabetes and after treatment with oral triethylenetetramine (TETA)
Authors: Ugarte Marta , Brown Marie , Hollywood Katherine A , Cooper Garth J , Bishop Paul N , Dunn Warwick B
Published: April 2012

Background

The prevalence, and associated healthcare burden, of diabetes mellitus is increasing worldwide. Mortality and morbidity are associated with diabetic complications in multiple organs and tissues, including the eye, kidney and cardiovascular system, and new therapeutics to treat these complications are required urgently. Triethylenetetramine (TETA) is one such experimental therapeutic that acts to chelate excess copper (II) in diabetic tissues and reduce oxidative stress and cellular damage.

Methods

Here we have performed two independent metabolomic studies of serum to assess the suitability of the streptozotocin (STZ)-induced rat model for studying diabetes and to define metabolite-related changes associated with TETA treatment. Ultraperformance liquid chromatography-mass spectrometry studies of serum from non-diabetic/untreated, non-diabetic/TETA-treated, STZ-induced diabetic/untreated and STZ-induced diabetic/TETA-treated rats were performed followed by univariate and multivariate analysis of data.

Results

Multiple metabolic changes related to STZ-induced diabetes, some of which have been reported previously in other animal and human studies, were observed, including changes in amino acid, fatty acid, glycerophospholipid and bile acid metabolism. Correlation analysis suggested that treatment with TETA led to a reversal of diabetes-associated changes in bile acid, fatty acid, steroid, sphingolipid and glycerophospholipid metabolism and proteolysis.

Conclusions

Metabolomic studies have shown that the STZ-induced rat model of diabetes is an appropriate model system to undertake research into diabetes and potential therapies as several metabolic changes observed in humans and other animal models were also observed in this study. Metabolomics has also identified several biological processes and metabolic pathways implicated in diabetic complications and reversed following treatment with the experimental therapeutic TETA.
Revealing details: whole mount microRNA in situ hybridization protocol for zebrafish embryos and adult tissues
Authors: Lagendijk Anne Karine , Moulton Jon D. , Bakkers Jeroen
Published: April 2012

Non-coding microRNA (miRNA) molecules bind their target mRNAs and thereby modulate the amount of protein produced. To understand the significance of a potential miRNA-mRNA interaction, temporal and spatial information on miRNA and mRNA expression is essential. Here, we provide a detailed protocol for miRNA whole mount in situ hybridization. We introduce the use of Morpholino based oligos as antisense probes for miRNA detection, in addition to the current “gold standard” locked nucleic acid (LNA) probes. Furthermore we have modified existing miRNA in situ protocols thereby improving both sensitivity and resolution of miRNA visualization in whole zebrafish embryos and adult tissues.
Serum 25 hydroxy-vitamin D does not exhibit an acute phase reaction after acute myocardial infarction
Authors: Barth J H , Field H P , Mather A N , Plein S
Published: April 2012

Background

There is growing epidemiological evidence linking serum 25 hydroxy-vitamin D (25(OH)D) concentrations to outcome in cardiovascular and other diseases. We have studied patients with acute myocardial infarction (AMI) to determine if they exhibit an acute phase reaction affecting 25(OH)D.

Methods

Patients ( n= 32) with first AMI who had been treated with primary percutaneous coronary intervention within 12 h of symptom onset had venous blood samples taken two days, one week, one month and three months after presentation. Samples were analysed for troponin I, C-reactive protein (CRP) and 25(OH)D.

Results

All patients had significant rises in troponin confirming the myocardial damage and CRP, both of which resolved by 28 days. In contrast, 25(OH)D remained unchanged throughout the 90-day observation period with a median concentration of 46 nmol/L.

Conclusion

Serum 25(OH)D does not change after AMI and is likely to be a reliable marker of vitamin D status in patients with cardiovascular disease.
Maternal mortality in northern Nigeria: findings of a health and demographic surveillance system in Zamfara State, Nigeria
Authors: Doctor Henry Victor , Olatunji Alabi , Findley Sally E , Afenyadu Godwin Y , Abdulwahab Ahmad , Jumare Abdulazeez
Published: April 2012

The aim of this study was to estimate: (1) the lifetime risk (LTR) of maternal death; and (2) the maternal mortality ratio (MMR) in the Zamfara State of northern Nigeria. Data from the Nahuche Health and Demographic Surveillance System were utilized using the ‘sisterhood method’ for estimating maternal mortality. Female respondents (15–49 years) from six districts in the surveillance area were interviewed, creating a retrospective cohort of their sisters who had reached the reproductive age of 15 years. Based on population and fertility estimates, we calculated the LTR of maternal death and the MMR. A total of 17,087 respondents reported 38,761 maternal sisters of whom 3592 had died and of whom 1261 were maternal-related deaths. This corresponded to an LTR of maternal death of 8% (referring to a period of about 10.5 years prior to the survey) and an MMR of 1049 deaths per 100,000 live births (95% confidence interval, 1021–1136). The study provides documented evidence of high maternal mortality in the study area and the state as a whole. Thus, there is a need to improve the health system with an emphasis on interventions that will accelerate reduction in MMR such as the availability of skilled birth attendants and emergency obstetric care, promotion of facility delivery and antenatal care attendance. This can be achieved through a holistic approach and is critical in order to accelerate progress in meeting the Millennium Development Goal of maternal mortality reduction.
Pelvic tuberculosis mimicking advanced ovarian malignancy
Authors: Devi Lajya , Tandon Rimpy , Goel Poonam , Huria Anju , Saha Pradip Kumar
Published: April 2012

We sought to identify the characteristic features of pelvic tuberculosis (TB) in women with symptoms and sonogaphic findings which were otherwise consistent with an ovarian malignancy. This study is a retrospective analysis of 138 women who underwent an operation and had a preoperative diagnosis of ovarian malignancy at the Government Medical College Hospital, Chandigarh, from January 2004 to January 2008. Among these 138 women, seven cases (5.7%) of pelvic TB were identified. Abdominal pain and distension were the most common presenting symptoms. All patients had a pelvic mass, six had ascites (85%) and five had a fever (71%). The mean cancer antigen (CA) 125 level was 295 IU (13–529). Pelvic TB can present with symptoms and signs which mimic ovarian malignancy. Therefore, a high-index of clinical suspicion should be maintained when treating patients in countries with a high prevalence of TB.
Minimum Mining Grade of Associated Li Deposits in Coal Seams
Authors: Sun Yuzhuang , Yang Jingjing , Zhao Cunliang
Published: April 2012

High Li concentration in coal seams has been reported by several papers in recent years. However, there is no minimum mining grade (or minimum economic grade; or ore border grade; or cut off grade) for lithium in coal seams because associated Li ore deposits in coal seams have not been found until now. In this paper, the minimum mining grade is suggested by compared the Li enrichment in coal with the Geology and Ore Deposit Standard Specifications in rocks for Rare Metal Mineral Exploration of the People's Republic of China (DZ/T 0203–2002), and also compared with the minimum mining grade for Ga and Ge in coals.
Petrographic and Geochemical Characterization of Coals from Tiru Valley, Nagaland, NE India
Authors: Singh Prakash K , Singh M. P. , Singh Alok K , Naik A. S.
Published: April 2012

In Tiru valley region of Mon district coals occur in Barail Formation and are of Oligocene age. This study is the first investigation on the petrographic and geochemical characterization of these coals. These thinly bedded seams (<2 m) need systematic exploration for proper evaluation of the resource.

The coals are bright to moderately bright in appearance and at places look moderately dull. The study reveals that Tiru valley coals are sub-bituminous to bituminous-D in rank. The chemical study reveals that these coals are perhydrous in nature with moderately high volatile matter content. The sulphur content was probably increased with pyrite inclusion as the most abundant mineral. Vitrinite is the most dominant maceral group constituting nearly 98% of all the macerals while liptinite and inertinite occur in very low concentration. Facies-critical models used to decipher the paleodepositional environment suggest that these coals evolved under wet moor with moderately high flooding in the paleomire which allowed the sulphate reducing bacteria to thrive.
Optimization of Enzymatic Hydrolysis of Corn Stover for Improved Ethanol Production
Authors: Zambare Vasudeo P. , Christopher Lew P.
Published: April 2012

Response surface methodology (RSM) was used to optimize the enzymatic hydrolysis of corn stover (CS), an abundant agricultural residue in the USA. A five-level, three-variable central composite design (CCD) was employed in a total of 20 experiments to model and evaluate the impact of pH (4.1–6.0), solids loadings (6.6–23.4%), and enzyme loadings (6.6–23.4 FPU g−1 DM) on glucose yield from thermo-mechanically extruded CS. The extruded CS was first hydrolyzed with the crude cellulase of Penicillium pinophilum ATCC 200401 and then fermented to ethanol with Saccharomyces cerevisiae ATCC 24860. Although all three variables had a significant impact, the enzyme loadings proved the most significant parameter for maximizing the glucose yield. A partial cubic equation could accurately model the response surface of enzymatic hydrolysis as the analysis of variance (ANOVA) showed a coefficient of determination (R2) of 0.82. At the optimal conditions of pH of 4.5, solids loadings of 10% and enzyme loadings of 20 FPU g−1 DM, the enzymatic hydrolysis of pretreated CS produced a glucose yield of 57.6% of the glucose maximum yield which was an increase of 10.4% over the non-optimized controls at zero-level central points. The predicted results based on the RSM regression model were in good agreement with the actual experimental values. The model can present a rapid means for estimating lignocellulose conversion yields within the selected ranges.
The Role of Geothermal Energy in Sustainable Development of Turkey
Authors: Dursun Bahtiyar , Gokcol Cihan
Published: April 2012

Energy can strongly act a key role in socio-economical development of Turkey. Turkey's energy needs are always increasing because Turkey has a rapidly growing economy and population. Although Turkey has numerous renewable energy sources, Turkey meets 12.8% of total demand from its own indigenous sources and unfortunately 87.2% of that from oil and gas supplying countries. This disastrous reality makes Turkey a big energy importing country. Otherwise, Turkey, in fact, can provide all energy demand from its abundant domestic sources itself. Although Turkey has the seventh big geothermal energy potential of the world, it exploits only 1.2% of all energy demand from geothermal energy. In this study, the role of geothermal energy in sustainable development of Turkey is particularly emphasized. To do this, potential and utilization of geothermal energy in Turkey are firstly presented in detail, and then importance and future developments of geothermal energy in Turkey are underlined.
Ant Colony Optimization Based on Multi-Searching to Estimate the Natural Gas Demand: Case of Turkey
Authors: Toksari M. Duran , Toksari Murat
Published: April 2012

In this paper we propose a new version of the Ant Colony Optimization (ACO) to predict the natural gas demand problem. This heuristic approach will estimate the Turkey's natural gas demand based on economic indicators. The well-known ACO is multi-agent systems in which the behavior of each ant is inspired by the foraging behavior of real ants to solve optimization problem. In this paper the proposed approach presents that the many ant colonies begin the searching from different random points. Ant Colony Optimization Natural Gas Demand Estimation (ACONGDE) model is developed using population, gross domestic product (GDP), import and export. All equations proposed here are linear and quadratic. Quadratic_ACONGDE provided better fit solution due to the fluctuations of the economic indicators. The ACONGDE model plans the natural gas demand of Turkey until 2025 for three scenarios. We also present an estimation of the natural gas demand for Central Anatolia Region of Turkey using population rates.
Temperature and Time Effects on Free Radical Concentration in Organic Matter: Evidence from Laboratory Pyrolysis Experimental and Geological Samples
Authors: Qiu Nansheng , Li Huili , Xu Ershe , Qin Jianzhong , Zheng Lunju
Published: April 2012

The free radicals concentration ( Ng) of organic matter evolves with the temperature, time, kerogen types and other factors for the individual kerogens. This paper focuses on the Ng evolution of immature type I and II kerogens and a type III coal under the laboratory pyrolysis temperature and heating time. The experiments were carried out in a closed system pyrolysis at an isothermal reactor in the temperature range from 300 to 500°C over 30 to 480 minutes. A temperature time index ( TTI) is applied and the TTI values were calculated in order to indicate the pyrolysis temperature and time at which the kerogen had experienced. Some equations were established to show the relationship between the TTI and Ng of type I, II and III kerogens, based on the tested data from laboratory anhydrous pyrolysis experiments of three kerogen types and geological type I kerogen samples. However, the evolution of free radicals concentration with temperature and time shows some differentials between different types of kerogen samples. This paper also discusses the different TTI- Ng relation of type I kerogen between laboratory pyrolysis experimental and geological samples, which are collected from core samples with depth interval of 1137 to 4090.6 m. The TTI- Ng equation from pyrolysis experimental samples should be calibrated by the data from geological samples when the equation is to be extended to the geological timescales. As the free radical concentration in organic matter is strongly maturity dependent, the relationship between TTI- Ng may prove to be a valuable method to study paleotemperature of sedimentary basins.
Heavy Metal Ion Removal Characteristics of Monodisperse Macroporous Beads with Anion-Exchanger Molecular Brushes
Authors: Ersan Hülya Yavuz , Turgut Hulusi
Published: April 2012

Polyethyleneimine-functionalized poly(VBC- co-DVB) beads were prepared and their adsorption/desorption properties towards Cd(II), Co(II) and Cu(II) ions were studied. The amounts of metal ions adsorbed increased only a little on changing the pH of the associated solution within the range 2–6 for Cd(II) and Co(II) ions, especially after pH 5. However, the amount of Cu(II) ions adsorbed at pH 6 was significantly higher than that adsorbed within the above pH range. The equilibrium adsorption capacities obtained for Cu(II), Cd(II) and Co(II) ions were 26.6, 30.8 and 32.2 mg metal ion/g sorbent, respectively. The equilibrium adsorption data for all the metal ions could be fitted by the monolayer Langmuir model. The data for Cu(II) ions exhibited the highest correlation coefficient and highest affinity constant of all the metal ions studied. According to kinetic studies, 80% of the maximum adsorption capacities were achieved for all the heavy metal ions within 2 h, after which the extent of adsorption attained a plateau value. The kinetic data revealed that adsorption was rapid over the first 30 min for Cd(II) and Cu(II) ions compared to Co(II) ions. The kinetic data for the adsorption of all the metal ions studied obeyed the pseudo-second-order kinetic model.
Effect of Cation Exchange on the Performance of Clinoptilolite Mineral in the Ethanol Dewatering Process
Authors: Pourreza Keyvan , Sharifnia Shahram , Khatamian Masoumeh , Rezaei Babak
Published: April 2012

This study describes the effect of cation exchange (Ni2+ and Ca2+) on the adsorption capacity and breakthrough time of a natural zeolite (clinoptilolite) employed in the ethanol dewatering process. The results obtained showed that modification of clinoptilolite (Clin) by cation exchange led to a decrease in the breakthrough time and water adsorption capacity in the order: Ca-Clin > Ni-Clin > Clin. In addition, characterization of the prepared clinoptilolite samples by BET, XRD and SEM techniques showed that no degradation of crystallinity had occurred, although the pore volumes of both cation-exchanged samples had increased as well as the surface area of the Ni-Clin sample.
Preparation of Ultrafine Pigment Dispersion and Investigation of its Adsorption Performance on Cationized Flax Substrate
Authors: Hao Longyun , Cai Yuqing , Wang Rui
Published: April 2012

An ultrafine pigment dispersion was prepared using sodium methylene dinaphthalene disulphonate (NNO) as the dispersant in conjunction with micro-jet milling. The particle size distribution measured by dynamic light scattering (DLS) showed that the pigment particle size was less than 200 nm, with the particles uniformly dispersed in aqueous media. Freeze–thaw treatment indicated that the ultrafine pigment dispersion had good storage stability. Flax fabrics were cationized by means of a polymeric quaternary ammonium salt employing an exhaustive method and the adsorption properties of the ultrafine pigment on this substrate were investigated. The results indicated that the percentage adsorption performance of the pigment was influenced by the particle size, the pH, the time and the temperature. The kinetics of pigment adsorption were studied with the resulting data being fitted by the first-order rate equation. This allowed the respective first-order adsorption rate constant, k1, and the adsorption half-time, t1/2, to be calculated.
Optimization and Kinetics of Cellulase Immobilization on Modified Chitin Using Response Surface Methodology
Authors: Jabasingh S. Anuradha
Published: April 2012

This study was aimed at investigating the immobilization of Aspergillus nidulans cellulase onto modified chitin (MC). The effects of contact time, cellulase concentration, MC dosage, temperature and agitation rate for maximum immobilization percentage and optimum immobilization capacity have been investigated by response surface methodology (RSM) on the basis of a five-level, five-factor central composite design (CCD). The equilibrium nature of the immobilization was described by the Langmuir and Freundlich isotherms. The kinetic data were tested using the first-order and pseudo-second-order kinetic models. The results of thermodynamic investigations indicate spontaneity (ΔG0 < 0), endothermicity (ΔH0 > 0) and irreversibility (ΔS0 > 0) for the sorption process. At 120 rpm, 304.6 K, 23.3 min, 1.12 mg of MC immobilized 18.51 mg/g of cellulase from an initial solution concentration of 16.34 mg/mℓ with a retention of 70% of the native cellulase activity up to 10 cycles in batch hydrolysis experiments. Under optimized conditions, immobilized cellulase had a higher Km value (0.83 mM) and a lower Vmax value (38.2 μmol/min) compared with the free cellulase (0.62 mM and 48.92 μmol/min, respectively), indicating the affinity of cellulase for the MC matrix.
Synthesis, Characterization and Application of a New Chelating Resin Containing 2-(4-Methylbenzylidene)hydrazone
Authors: Kumar Rajesh , Jain S.K.
Published: April 2012

The functionalization of 2-(4-methylbenzylidene)hydrazone onto chloromethylated styrene–divinylbenzene copolymeric resin has been explored in this study. The structure of the functionalized resin was confirmed by FT-IR spectroscopy and its use for the adsorption of Ni(II) and Co(II) ions from aqueous solution studied. The effects of pH, initial concentration of metal ion and contact time on the adsorption process were examined using batch experiments. The Langmuir and Freundlich models were applied to the equilibrium adsorption data obtained, when it was found that both isotherms gave a reasonable fit. For initial concentrations of 1000 μg/ℓ, maximum adsorption capacities for Ni(II) and Co(II) ions of 6.67 mg/g and 9.985 mg/g, respectively, were obtained. The adsorption kinetics followed the pseudo-second-order model and the rate constants for this kinetic model were calculated. The experimental results indicated that the functionalized resin has the potential for use as a good adsorbent for the removal of Ni(II) and Co(II) ions from contaminated water.
A Note on the Acoustics of Orchestra Rehearsal Rooms
Authors: Pompoli Roberto , Prodi Nicola , Farnetani Andrea
Published: April 2012

The acoustical conditions of rehearsal rooms are of primary importance during the training process of an orchestra. Therefore these spaces should be specifically designed to allow the musicians to clearly hear themselves and each other. At the same time an appropriate sound level should be maintained to avoid extensive exposure to high pressure levels. Despite the peculiar role of these rooms in the musical production, the criteria for their acoustical design are not still sufficiently clarified. This paper deals with a description of a design process which, starting from simple formulas of a reverberant field, leads to investigate the relevance of geometrical and acoustical parameters on the final performance of a rehearsal room. The influence of the values of the ratio V/N (Volume/Number of musicians), S/N (floor surface/number of musicians), W/N (Sound power/Number of musicians) on objective acoustic parameters such as STEarly (Early support) will be described. A guideline for the acoustic design of an orchestra rehearsal room will be finally proposed. Some specific case histories of rehearsal rooms will be discussed.
The Effect of an Edge on the Measured Scattering Coefficients in a Reverberation Chamber Based on ISO 17497-1
Authors: Kim JungSu , Lee JinHak , Choi YoungJi , Jeong DaeUp
Published: April 2012

The scattering coefficient has been regarded as one of the important factors to be considered in the acoustic design of a room. ISO 17497-1 provides a method for measuring the random-incidence scattering coefficients in a reverberation chamber. However, the uncertainties of this method due to the lack of details with respect to the measurement conditions have been reported. It is necessary to provide more specific guidelines for this method. The present study suggests an improved measurement method by investigating the edge effects. The scattering coefficients of a simple 1-dimensional diffuser were measured in a 1/5 scale model of the reverberation chamber based on ISO 17497-1. The effects of an edge strip on the scattering coefficients were measured and analysed. Further, several issues with respect to the sample diameter, the air gap below the turntable and the absorption of the test sample were discussed.
Façade Elements for Natural Ventilation and Sound Insulation
Authors: de Araújo Bianca C. D. , Bistafa Sylvio R.
Published: April 2012

The indoor environmental comfort requires nowadays the pursuit of architectural alternatives with less energy demand. In hot and humid climates, natural ventilation is one of the design strategies that can be applied to reduce energy consumption in buildings. According to this vision, elements with apertures ( cobogó or combogó, as they are popularly known in northeastern Brazil) are architectural elements that provide permanent natural ventilation, sun protection and natural lighting. However, there are acoustic problems associated with the sound insulation that they provide. The present study had the goal of developing elements with apertures to mitigate the conflict between the thermal-acoustic comfort demands. The sound insulation performance of the elements was evaluated in situ according to the ISO 140–5 standard. The natural ventilation characteristics of the elements were investigated by means of computer simulations, using methods of computational fluid dynamics – CFD. Four types of elements had been proposed, which were acoustically evaluated in different mounts on a wall-like facade. The results showed how difficult is to control the transmission of sound at low frequencies in facades with apertures, however, satisfactory sound insulation results were obtained with one type of mounting, which gave an Weighted Standardized Level Difference Dnt, w value of 27 dB. The CFD simulations show that because of its geometrical characteristics, this mounting also provides the best flow conditions for internal natural ventilation, despite the fact that its % of open area of 12% is not the highest amongst the proposed elements. Calculated values of measures of comfort ventilation show that the mountings with the best sound insulation characteristics are also capable of providing adequate values of ventilation ratios and air changes per hour in the test suite that was used for measuring sound insulation.
The Refurbishment of the Orchestra Rehearsal Room of the Great Theater of Liceu
Authors: Arau-Puchades Higini
Published: April 2012

The original Orchestra Rehearsal Room of the Great Theater of the Liceu, inaugurated in October 1999, was sufficient to accommodate a medium sized orchestra but it was not suitable for a large orchestra because of its small volume and because the sound produced by the musicians was too loud. This initial deficiency has been corrected in many aspects by applying a new acoustic concept. We developed a 3D-Grid diffuser which resulted in a very significant increase in Reverberation Time and increased the clarity of communication between players and the subjective size of the room volume.
Relationships between Measured Levels and Subjective Ratings: A Case Study of the Food-Court Area in CEPA Shopping Center, Ankara
Authors: Dökmeci Papatya Nur , Yılmazer Semiha
Published: April 2012

Physical comfort requirements of users; such as, thermal, visual, and acoustic comfort, should be considered and studied in detail when planning and designing public spaces. However, there is not enough research on the relations between the acoustical parameters, and the acoustic comfort level of users in enclosed non-acoustic public spaces, which are directly connected with a central atrium. In such spaces, evaluation on auditory perception and noise annoyance should be performed in parallel with objective parametric measurements. The food-court area of CEPA Shopping Center, with a central atrium and a glass ceiling structure, in the capital city of Turkey, Ankara is chosen for the case. The aim of this study is to investigate the relationships between the users' subjective ratings of noise levels and the measured equivalent continuous sound pressure levels (Leq). In addition, the demographical differences and user profile variances, as well as the auditory perception classifications are investigated in this case space. The present acoustical indices are measured and then discussed by pointing out the architectural features of the case space, which are the central atrium, glass ceiling structure and the sound reflective material applications. The research methods include, noise measurements to obtain Leq and questionnaires to assess the subjective ratings and auditory perception of the users. This study mainly concentrates on the food-court space, which is within CEPA Shopping Center and displays the significant results regarding this space. These results show that Leq values vary by different day types (weekdays and weekends) and time of day, and the subjective ratings correlate well with these Leq variances. The most dominant sound perceived by the users was found to be the hum of voices. One other significant result implies that, subjective ratings of noise level becomes significant above 67 dBA and shows a sudden increase in the ratings. Furthermore, the time spent in the food-court area correlated significantly with noise annoyance ratings.
Innovative Use of FRP for the Precast Concrete Industry
Authors: Rizkalla S. , Lucier G. , Dawood M.
Published: April 2012

This paper presents several advancements in the use of fiber reinforced polymer (FRP) materials for the precast concrete industry. Precast concrete members are commonly selected for reasons such as the high level of quality control used in their production, the durability of the finished structure, reduced labor costs and shorter construction schedules, and the economics of scale achieved with mass-production of components. The environmental durability, high strength to weight ratio, and ease of installation of FRP reinforcements an attractive alternative material for the precast industry. This paper presents several advancements in the use of FRP grid as flange reinforcement for precast double-tee members, as a shear transfer mechanism for thermally efficient composite and partially-composite load bearing wall panels, as reinforcement for precast architectural cladding panels. Each of these applications highlights the advantages of using FRP materials to achieve significant enhancement of the structural, thermal and architectural performance. The innovative use of the FRP materials and the unique construction techniques described have resulted in the development of safe and functional structures, as demonstrated by the research conducted by the authors and others in collaboration with the precast industry.
Flexural Fatigue Performance of CFRP Prestressed Concrete Poles
Authors: Roberts E.E. , Lees J.M. , Hoult N.A.
Published: April 2012

Carbon fibre reinforced polymer (CFRP) prestressed concrete poles offer a durable, light-weight alternative to conventional steel-reinforced or prestressed concrete poles. In particular, the corrosion resistance of the CFRP tendons can result in lower maintenance costs and a reduction in the required concrete cover. For lighting poles used in pedestrian or low-trafficked areas, wind loading represents a dominant load case. The wind acts as a transient force and can blow from any direction. It is therefore of interest to investigate how CFRP prestressed lighting poles perform under repeated cyclic loads and/or load reversals. Experiments were carried out on pole sections tested horizontally. These included a static control test and a conventional fatigue test where a cyclic load was applied in a downwards direction for 2 million cycles. Three further fatigue tests where the load direction changed, either after a defined number of cycles or within a load cycle, were also conducted. It was found that all the poles performed adequately for 1–2 million cycles of loading and that the majority of any deflection increases occurred within the first 50,000 cycles. It is believed that repeated cyclic loading may have increased the tendon debonding at the crack locations. Localised debonding potentially relieves the stress in the outermost tendon layer which delays the onset of failure and allows the inner tendon layers to take up further stress thus leading to a higher load carrying capacity. Loading orientation reversal from a downwards to an upwards direction within a loading cycle did not result in a greater stiffness degradation when compared to the other fatigue tests. The initial findings suggest that in-service cyclic loading and load reversals will not be detrimental to the performance of CFRP prestressed concrete poles.
Composite Behaviour of a Hybrid FRP Bridge Girder and Concrete Deck
Authors: Manalo A.C. , Aravinthan T. , Mutsuyoshi H. , Matsui T.
Published: April 2012

This paper involves experimental investigation onto the composite behaviour of a hybrid FRP bridge girder with an overlying concrete deck. Two types of shear connections were investigated: epoxy resin adhesives alone and epoxy resin combined with steel u-bolts. The results showed that the steel u-bolts combined with epoxy resin provided a more effective connection; hence a full-size specimen was prepared based on this result. Four-point bending test was carried out to determine the behaviour of a full-scale composite hybrid FRP girder and concrete deck. The composite action resulted to a higher stiffness and strength with the hybrid FRP girder exhibiting higher tensile strain before final failure. There was a significant decrease in the compressive strain in the top flange of the FRP girder thereby preventing the sudden failure of the beam. The composite beam failed due to crushing of the concrete followed by shear failure in the top flange and web of the FRP girder.