bluuebunny/crossref_metadata_2025 huggingface dataset:
Market Segmentation of an International Cultural-Historical Event in Italy
Authors: Formica Sandro , Uysal Muzaffer
Published: March 2008

This study explores the existing markets of a unique annual event, the Spoleto Festival in Italy, that blends inter nationally well-known cultural exhibitions with historical settings. Behavioral, motivational, and demographic char acteristics of festival visitors were examined by using a posteriori market segmentation. Factor analysis was performed to determine the leading motivations for attending the international cultural-historical event, whereas cluster analysis was employed to identify groups of respondents based on motivational behaviors. Based on the findings, two distinct groups were formed: Enthusiasts and Moderates. The results of the study show statistically significant differences between the two groups in terms of age, income, and marital status. Marketing and management implications for effectively targeting the two market segments are discussed.
Ecotourism and Ethics: Moral Development and Organizational Cultures
Authors: Cruise Malloy David , Fennell David A.
Published: March 2008

As the ecotourism industry grows and matures, the need to address ethical conduct from an organizational perspective becomes increasingly more important for this sector to survive and prosper into the 21st century. The literature suggests that those organizations with ethical cultures tend to provide work environments that encourage employee personal growth and development and provide more efficient, effective, and productive business outcomes for the stake-holders than those organizations whose ethical practices are questionable. The purpose of this article is to present a model and hierarchy of ethical organizational cultural ty pologies as they apply to ecotourism. Those who work in the field may find this framework helpful in identifying the nature of an ecotourism organization's ethical culture. The framework may also provide a developmental structure for enhancing or transforming an ecotourism organization.
Defining the Tourist: Is It Possible? A View from the Convention and Visitors Bureau
Authors: Masberg Barbara A.
Published: March 2008

Defining a tourist is a difficult proposition, as shown by the use of dissimilar definitions in various books, articles, re search reports, and serials. This article investigated the defi nitions used by research managers at convention and visitors bureaus (CVBs). Distance traveled is used most often to identify the tourist, but the figure used to identify that same tourist fluctuates between 20 and 150 miles. The type of indi vidual from whom CVBs seek information also varies with the number of CVBs that contact these types and the fre quency of the contact. The significance of these data is that the individuals used to describe the tourist and measure tour ist behavior is inconsistent between the various CVBs.
Simulating the Impacts of Gambling in a Tourist Location: Some Evidence from Israel
Authors: Felsenstein Daniel , Freeman Daniel
Published: March 2008

Gambling and tourism are often perceived as comple mentary activities. This article examines this relationship both conceptually and empirically. While land-based casino gambling is not a legalized activity at present in Israel, the economic impacts of introducing a casino at Israel's premier vacation resort, Eilat, are simulated. This ex ante evaluation shows that much of the output, income, and employment gains generated by a casino are likely to be captured outside the region and that localized impacts are small. The dis placement of existing local economic activity is examined, and the case of increased tourism expenditures generated by the casino is simulated. The public policy implications of these findings point to the necessity of developing activities that complement tourism at the local level, not just at the na tional level. The gambling-tourism relationship simulated for Eilat shows that national and local interests are not al ways synonymous.
Evolution of the chicken Toll-like receptor gene family: A story of gene gain and gene loss
Authors: Temperley Nicholas D , Berlin Sofia , Paton Ian R , Griffin Darren K , Burt David W
Published: March 2008

Background

Toll-like receptors (TLRs) perform a vital role in disease resistance through their recognition of pathogen associated molecular patterns (PAMPs). Recent advances in genomics allow comparison of TLR genes within and between many species. This study takes advantage of the recently sequenced chicken genome to determine the complete chicken TLR repertoire and place it in context of vertebrate genomic evolution.

Results

The chicken TLR repertoire consists of ten genes. Phylogenetic analyses show that six of these genes have orthologs in mammals and fish, while one is only shared by fish and three appear to be unique to birds. Furthermore the phylogeny shows that TLR1-like genes arose independently in fish, birds and mammals from an ancestral gene also shared by TLR6 and TLR10. All other TLRs were already present prior to the divergence of major vertebrate lineages 550 Mya (million years ago) and have since been lost in certain lineages. Phylogenetic analysis shows the absence of TLRs 8 and 9 in chicken to be the result of gene loss. The notable exception to the tendency of gene loss in TLR evolution is found in chicken TLRs 1 and 2, each of which underwent gene duplication about 147 and 65 Mya, respectively.

Conclusion

Comparative phylogenetic analysis of vertebrate TLR genes provides insight into their patterns and processes of gene evolution, with examples of both gene gain and gene loss. In addition, these comparisons clarify the nomenclature of TLR genes in vertebrates.
Estrogen and Progesterone Metabolism in the Cervix during Pregnancy and Parturition
Authors: Andersson Stefan , Minjarez Debra , Yost Nicole P. , Word R. Ann
Published: March 2008

Context: Experimental and clinical studies in a variety of nonprimate species demonstrate that progesterone withdrawal leads to changes in gene expression that initiate parturition at term. Mice deficient in 5α-reductase type I fail to undergo cervical ripening at term despite the timely onset of luteolysis and progesterone withdrawal in blood.

Objective: Our objective was to test the hypothesis that estrogen and progesterone metabolism is regulated in cervical tissues during pregnancy, even in species in which parturition is not characterized by progesterone withdrawal in blood.

Design: Estradiol and progesterone metabolism was quantified in intact cervical tissues from nonpregnant and pregnant women at term before or after labor.

Setting: The study was conducted at a university hospital.

Patients: Tissues were obtained from five nonpregnant and 21 pregnant women (nine before labor and 12 in labor).

Main Outcome Measures: Enzyme activity measurements, Northern blot analysis, quantitative real-time RT-PCR, and immunohistochemistry were used to quantify steroid hormone metabolizing enzymes in cervical and myometrial tissues.

Results: During pregnancy, 17β-hydroxysteroid dehydrogenase type 2 was induced in glandular epithelial cells to catalyze the conversion of estradiol to estrone and stroma-derived 20α-hydroxyprogesterone to progesterone. During parturition, 17β-hydroxysteroid dehydrogenase type 2 was down-regulated in endocervical cells, thereby creating a microenvironment favorable for cervical ripening.

Conclusions: Together, the data indicate that cervical ripening during parturition involves localized regulation of estrogen and progesterone metabolism through a complex relationship between cervical epithelium and stroma, and that steroid hormone metabolism in cervical tissues from pregnant women is unique from that in mice.
Three-dimensional elasticity solution for simply supported rectangular plates with variable thickness
Authors: Xu Y-P , Zhou D
Published: March 2008

This paper studies the stress and displacement distributions of rectangular plates with a continuously varying thickness that are simply supported at four edges. On the basis of three-dimensional elasticity theory, the general expressions for the displacements and stresses of the plate under static loads, which exactly satisfy the governing differential equations and the simply supported boundary conditions at four edges of the plate, are analytically derived. The unknown coefficients in the general expressions of the stresses are approximately determined by using the double Fourier sinusoidal series expansions to the boundary conditions on the upper and lower surfaces of the plate. The present solution gives rapid convergence and accurate results which are in good agreement with those obtained from the commercial finite element software ANSYS.
Evaluation of significant transitions in the influencing factors of human reliability
Authors: Konstandinidou M , Nivolianitou Z , Kiranoudis C , Markatos N
Published: March 2008

This paper describes sensitivity analysis of a previously developed model for the estimation of the probability of human erroneous actions in specific industrial and working contexts. The model has been built using the fuzzy logic theory. The fuzzy model developed includes nine input parameters according to the CREAM (cognitive reliability and error analysis method) methodology. The model has been used in order to detect the critical transitions in the optimization of human reliability, for corresponding changes in each of the nine input parameters. Changes in the working context have been evaluated through their relevant reduction to the action failure probability of the human operator. The results of the fuzzy model, after the defuzzification process, are human error probabilities in the form of crisp numbers, which can eventually be used in probabilistic assessments and cost—benefit analyses in order to compare the parameters’ adjustment cost with the impact this adjustment has on the performance and reliability of the human operator.
Glucocorticoid Therapy-Induced Memory Deficits: Acute versus Chronic Effects
Authors: Coluccia Daniel , Wolf Oliver T. , Kollias Spyros , Roozendaal Benno , Forster Adrian , de Quervain Dominique J.-F.
Published: March 2008

Conditions with chronically elevated glucocorticoid levels are usually associated with declarative memory deficits. Considerable evidence suggests that long-term glucocorticoid exposure may cause cognitive impairment via cumulative and long-lasting influences on hippocampal function and morphology. However, because elevated glucocorticoid levels at the time of retention testing are also known to have direct impairing effects on memory retrieval, it is possible that such acute hormonal influences on retrieval processes contribute to the memory deficits found with chronic glucocorticoid exposure. To investigate this issue, we examined memory functions and hippocampal volume in 24 patients with rheumatoid arthritis who were treated either chronically (5.3 ± 1.0 years, mean ± SE) with low to moderate doses of prednisone (7.5 ± 0.8 mg, mean ± SE) or without glucocorticoids. In both groups, delayed recall of words learned 24 h earlier was assessed under conditions of either elevated or basal glucocorticoid levels in a double-blind, placebo-controlled crossover design. Although the findings in this patient population did not provide evidence for harmful effects of a history of chronic prednisone treatment on memory performance or hippocampal volume per se, acute prednisone administration 1 h before retention testing to either the steroid or nonsteroid group impaired word recall. Thus, these findings indicate that memory deficits observed under chronically elevated glucocorticoid levels result, at least in part, from acute and reversible glucocorticoid effects on memory retrieval.
The LIM-Homeobox GeneIslet-1Is Required for the Development of Restricted Forebrain Cholinergic Neurons
Authors: Elshatory Yasser , Gan Lin
Published: March 2008

Forebrain cholinergic neurons modulate complex mammalian behaviors such as reward-related learning and cognitive functions. Although their dysfunction is implicated in various psychiatric and neurodegenerative diseases, the factors governing cholinergic neuron differentiation and diversity are mostly unknown. We tested the role of the LIM-homeobox geneIsl1in the development of forebrain cholinergic neurons by conditionally deletingIsl1using aSix3-cretransgene. A depletion of cholinergic interneurons in the dorsal and ventral striatum, and cholinergic projection neurons in the nucleus basalis is observed and is ascribed to an early and persistent defect in cholinergic neuron differentiation. Notably, cholinergic innervation to the neocortex is abolished, whereas that to the hippocampus is unaltered. The unique pattern of cholinergic hypoinnervation encountered is supported by the presence of cholinergic projection neurons in the medial septum, the magnocellular preoptic area, and the substantia innominata. Together, these results demonstrate the requirement for Isl1 in the development of restricted telencephalic cholinergic neurons and link the development of cholinergic neurons in anatomically disparate sites to Isl1 function.
Medidas antropométricas segundo aptidão cardiorrespiratória em militares da ativa, Brasil
Authors: Oliveira Eduardo de Almeida Magalhães , Anjos Luiz Antonio dos
Published: March 2008

OBJETIVO: Analisar as diferenças no índice de massa corporal (IMC) e no perímetro da cintura segundo a aptidão cardiorrespiratória em militares do sexo masculino. MÉTODOS: A amostra constituiu-se de 50.523 homens da ativa do exército brasileiro. Os dados antropométricos (massa corporal, estatura e perímetro da cintura) e de consumo máximo de oxigênio (VO2max), estimado por meio do teste de corrida de 12 minutos, foram obtidos no teste de aptidão física do ano 2001. RESULTADOS: A idade variou de 18 a 52 anos, porém foi composta em sua maioria por indivíduos jovens (média + DP = 25,8 + 6,6 anos de idade). A faixa de aptidão cardiorrespiratória variou de 22,2 a 82,5 mL O2.kg-1.min-1. Os valores médios do perímetro da cintura foram significativamente menores nos grupos de melhor aptidão cardiorrespiratória, quando comparados com os grupos com menor aptidão (p<0,001). Esse padrão se manteve mesmo após o ajuste pela idade, pelo IMC e por ambos. CONCLUSÕES: Para um mesmo valor do IMC, indivíduos com melhor aptidão cardiorrespiratória possuem valores significativamente menores de perímetro da cintura quando comparados com sujeitos de mais baixa aptidão. Esses achados sugerem acúmulo reduzido de gordura abdominal nos militares mais bem condicionados.
Topologia do risco de acidentes do trabalho em Piracicaba, SP
Authors: Zangirolani Lia Thieme Oikawa , Cordeiro Ricardo , Medeiros Maria Angélica Tavares de , Stephan Celso
Published: March 2008

OBJETIVO: Analisar a distribuição espacial do risco de acidente do trabalho controlado por variáveis nutricionais e outras co-variáveis. MÉTODOS: Estudo caso-controle espacial de base hospitalar, tendo como variável de interesse a localização espacial dos acidentes do trabalho. Foram amostrados 794 trabalhadores, no período de maio a outubro de 2004. Os critérios de inclusão para casos (N=263) foram: ser trabalhador acidentado do trabalho, morador de Piracicaba, com idade entre 15 e 60 anos, e atendido em centro de ortopedia e traumatologia. Os controles (N=531) tiveram o mesmo critério de idade e residência na cidade, exceto que o acidente não era do trabalho, tendo sido considerandos também trabalhadores acompanhantes dos casos. A distribuição espacial da estimativa baseou-se no ajuste do modelo aditivo generalizado, tendo as coordenadas geográficas dos casos e controles como componente espacial não linear e as demais co-variáveis como componente linear. RESULTADOS: A variação da estimativa do risco espacial de acidentes do trabalho, controlada por sexo (OR=1,87; p<0,001), escolaridade (OR=0,85; p<0,0001), ser autônomo (OR=0,36; p<0,01) e circunferência de cintura (OR=0,98; p=0,05), mostra que as regiões de maior risco foram a centro-leste e a área que forma um "corredor" entre as regiões sul-norte. CONCLUSÕES: O uso de ferramentas de geoprocessamento e a consideração de variáveis nutricionais fornecem elementos para a compreensão das relações que compõem o risco de acidentes do trabalho, sendo oportuna a continuidade de investigações que contemplem esses fatores.
Competencia en el sector salud: análisis de la reforma sueca (1992 - 1995)
Authors: Mould Quevedo Joaquín F , Salinas Escudero Guillermo , Contreras Hernández Iris , Garrido Solano Carlos
Published: March 2008

El artículo revisa los éxitos y fracasos de la reforma sueca de salud, así como las lecciones que dejó en su afán de alcanzar mejores resultados financieros y estándares de calidad.
Effects of Clinical Laboratory Choice on Study Outcome: An Interlaboratory Evaluation of Aminotransferase Levels
Authors: Green Jody L. , Campagna Elizabeth , Bogdan Gregory M. , Dart Richard C. , Heard Kennon
Published: March 2008

Study Objective. To determine if laboratories with disparate alanine aminotransferase (ALT) reference ranges would report different rates of elevation greater than the upper limit of reference range (ULRR) and thus have the potential to alter study results.

Design. Interlaboratory evaluation.

Setting. Research department of a poison and drug center.

Samples. Sixty‐five serum samples collected from a previously published randomized clinical trial that were stored at −57°C for approximately 2 years.

Intervention. Stored serum samples were divided and sent to two independent clinical laboratories (laboratory A and laboratory B) that had disparate ALT reference ranges.

Measurements and Main Results. Samples were stratified by ALT levels measured during the primary study to provide a spectrum of ALT values. The ULRR for serum ALT level at laboratory A was 63 and 54 U/L for male and female subjects, respectively, and for laboratory B was 31 U/L for both male and female subjects. Each laboratory used different instruments and reagents. The primary outcome was the rate of ALT elevation (> 1 x ULRR and > 3 x ULRR) for each study laboratory. The overall mean ALT activity at laboratory A was 33.6 U/L (95% confidence interval [CI] 28.1–39.2 U/L) and at laboratory B was 47.92 U/L (95% CI 40.0–55.8 U/L). Although laboratory A had the higher ULRR (74% higher for female subjects, 103% higher for male subjects), it consistently reported lower ALT values. Laboratory B reported a significantly higher proportion of samples that had an ALT value greater than 1 time the ULRR and greater than 3 times the ULRR.

Conclusion. Our findings suggest that laboratories systemically report different values for aminotransferase levels and that the choice of laboratory may alter the proportion of patients who have an elevation in ALT levels. Until standardized reference ranges are adopted, studies reporting an outcome that depends on the reference range (such as “abnormal” or > 3 x ULRR) will be subject to misclassification bias based on the laboratory performing the analysis.
Effectiveness of Probiotics in the Treatment of Irritable Bowel Syndrome
Authors: Wilhelm Sheila M. , Brubaker Christine M. , Varcak Elizabeth A. , Kale‐Pradhan Pramodini B.
Published: March 2008

Recently, the use of tegaserod and alosetron—drugs approved for the treatment of irritable bowel syndrome (IBS)—has been restricted because of adverse events. This has resulted in a need for additional modalities for the treatment of IBS. Our objective was to determine the effectiveness of probiotics in the global relief of symptoms associated with IBS and in the improvement of flatulence, abdominal pain, transit time, and bacterial counts. Using the MEDLINE database from 1966‐October 2007 and manually searching article references for relevant articles and abstracts, we identified 14 blinded, placebo‐controlled clinical trials of the effectiveness of probiotics in the treatment of IBS. Of 11 studies in which overall symptom relief was assessed, seven indicated a significant improvement with probiotics versus placebo. Five of eight investigations of abdominal pain and distention revealed a benefit with probiotic use. Four studies demonstrated an improvement in symptomatic flatulence in probiotic treatment groups, whereas one study showed no significant benefit. Four of five studies of the effects of probiotics on colonic transit time revealed a benefit compared with placebo. As probiotics have shown benefit and possess a favorable adverse‐effect profile, their use may represent an option for symptom relief in patients with IBS. However, additional data are necessary before probiotics can become a standard of care in the treatment of IBS, a complex and chronic condition.
Investigation of distributed Bragg reflector growth conditions for high‐brightness AlGaInP light‐emitting diodes
Authors: Oh H. S. , Kim K. H. , Lee J. H. , Baek J. H. , Yu Y. M. , Kwak J. S.
Published: March 2008

Abstract— The effect of growth conditions of a distributed Bragg reflector (DBR) structure on the performance of AlGaInP light‐emitting diodes (LEDs) have been investigated. Increasing the growth temperature and the flow rate of AsH3 as well as lowering the growth pressure resulted in improved reflectivity and root‐mean‐square (RMS) roughness of the high‐aluminum‐content multiple pairs of the DBR structure. An increase in the growth temperature may improve the mobility of atoms on the surface for the positioning of the right atomic site and to reduce oxygen incorporation. An increase in the flow rate of AsH3 can suppress the arsenic vacancy formation at higher V/III ratios. Furthermore, reduction in growth pressure can suppress the convection flow on the epitaxial growth surface. To verify the influence of DBR growth conditions on the successive growth of LED structures, the growth of full LED structures having two different DBR growth conditions was performed, and AlGaInP red LEDs using full LED structures were fabricated. It was found that higher growth temperature and AsH3 flow rate with lower growth pressure for the DBR structure produced improved output power of the AlGaInP LEDs, which can be attributed to the high reflectivity and low RMS roughness of the DBR structure.
Improving the biodegradability of grain distillery wastewater for use as UASB substrate by combinations of ozonation/enzymatic pre-treatments
Authors: Sigge G. O. , Gie L.-M. , Britz T. J.
Published: March 2008

The effect of ozonation and enzyme combination pre-treatments on the composition of grain distillery wastewater (GDWW) was investigated. Exposure of UASB granules to these pre-treated GDWW was evaluated by determining the effect on granule activity, visual appearance and lipid content of the granules. Pre-treatments involving a pre-ozonation step were found to be more effective in reducing the lipid and COD content of GDWW. The higher the lipid and COD reduction achieved by the pre-treatments the higher the granule activity after 24 d exposure, the lower the lipid content in the granule and the less severe the formation of an encapsulating layer.
Measurement and quantification of sessile and planktonic microbial populations during the anaerobic digestion of cellulose
Authors: Jensen P. D. , Hardin M. T. , Clarke W. P.
Published: March 2008

Crystalline cellulose was anaerobically degraded using a leachate inoculum derived from simulated municipal solid waste. Bicinchoninic Acid (BCA) protein assays were used to measure the distribution of biomass during cellulose degradation, including the planktonic and sessile biomass fractions. A comparison of sessile and planktonic microbial growth indicated that the microbial growth was dominated by the planktonic fraction with the biofilms accounting for approximately 25% of the population. Additional biomass measurements were conducted to test the reliability of the BCA protein assays. Total microbial growth was inferred from the accumulation and depletion of ammonia nitrogen measured using flow injection analysis. The planktonic biomass was estimated from direct cell counts using light microscopy and the sessile biomass was estimated by analysing the nitrogen content of the separated and washed cellulose pellet. Regression analysis showed good correlations between the measurement pairs representing the total biomass (R2=0.90), planktonic biomass (R2=0.97) and sessile biomass (R2=0.85), supporting the use of protein assays as an indicator of microbial growth in mixed culture environments.
Microbial characteristics of biogas
Authors: Moletta Marina , Wery Nathalie , Delgenes Jean-Philippe , Godon Jean-Jacques
Published: March 2008

The microbial diversity of biogas was analyzed in order to examine the aerosolization behavior of microorganisms. Six biogas samples were analyzed: five from mesophilic and thermophilic anaerobic digestors treating different wastes, and one from landfill. Epifluorescent microscopic counts revealed 106 prokarya m−3. To assess the difference occuring in aerosolization, 498 biogas-borne 16S ribosomal DNA were analyzed and compared to published anaerobic digestor microbial diversity. Results show a large microbial diversity and strong discrepancy with digestor microbial diversity. Three different aerosolisation behaviour patterns can be identified: (i) that of non-aerosolized microorganisms, Deltaproteobacteria, Spirochaetes, Thermotogae, Chloroflexi phyla and sulfate-reducing groups, (ii) that of passively aerosolized microorganisms, including Actinobacteria, Firmicutes and Bacteroidetes phyla and (iii) that of preferentially aerosolized microorganisms, including Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, as well as strictly aerobic and occasionally pathogenic species, presented high levels of aerosolization.
Characteristics of membrane fouling in submerged membrane bioreactor under sub-critical flux operation
Authors: Su Y. C. , Huang C. P. , Lee H. C. , Pan Jill R.
Published: March 2008

Recently, the membrane bioreactor (MBR) process has become one of the novel technologies to enhance the performance of biological treatment of wastewater. Membrane bioreactor process uses the membrane unit to replace a sediment tank, and this can greatly enhance treatment performance. However, membrane fouling in MBR restricts its widespread application because it leads to permeate flux decline, making more frequent membrane cleaning and replacement necessary, which then increases operating and maintenance costs. This study investigated the sludge characteristics in membrane fouling under sub-critical flux operation and also assessed the effect of shear stress on membrane fouling. Membrane fouling was slow under sub-critical flux operation. However, as filamentous microbes became dominant in the reactor, membrane fouling increased dramatically due to the increased viscosity and polysaccharides. A close link was found between membrane fouling and the amount of polysaccharides in soluble EPS. The predominant resistance was the cake resistance which could be minimized by increasing the shear stress. However, the resistance of colloids and solutes was not apparently reduced by increasing shear stress. Therefore, smaller particles such as macromolecules (e.g. polysaccharides) may play an important role in membrane fouling under sub-critical flux operation.
Evaluation of innovative operation concept for flat sheet MBR filtration system
Authors: Weinrich L. , Grélot A.
Published: March 2008

One of the most limiting factors for the extension and acceptance of MBR filtration systems for municipal and industrial wastewater is the impact of membrane fouling on maintenance, operation and cleaning efforts. One field of action in the European Research Project “AMEDEUS” is the development and testing of MBR module concepts with innovative fouling-prevention technology from three European module manufacturers.

This article deals with the performances of the flat-sheet modules by A3 Water Solutions GmbH in double-deck configuration evaluated over 10 months in Anjou Recherche under typical biological operation conditions for MBR systems (MLSS = 10 g/l; SRT = 25 days). By using a double-deck configuration, it is possible to operate with a net flux of 25.5 l/m2.h at 20°C, a membrane air flow rate of 0.21 Nm3/h.m2 of membrane to achieve a stable permeability of around 500–600 l/m2.h.bar. Additionally, it was observed that it is possible to recover the membrane performance after biofouling during operation without intensive cleaning and to maintain stable permeability during peak flows.The evaluated concepts for equipping and operating MBR systems will be applied to several full-scale plants constructed by A3 Water Solutions GmbH.
Effect of peracetic acid, ultraviolet radiation, nanofiltration-chlorine in the disinfection of a non conventional source of water (Tula Valley)
Authors: Trujillo J. , Barrios J. A. , Jimenez B.
Published: March 2008

Water supply for human consumption requires certain quality that reduces health risks to consumers. In this sense, the process of disinfection plays an important role in the elimination of pathogenic microorganisms. Even though chlorination is the most applied process based on its effectiveness and cost, its application is being questioned considering the formation of disinfection by-products (DBPs). Therefore, alternative disinfectants are being evaluated and some treatment processes have been proposed to remove DBPs precursors (organic matter. This paper reports the results of disinfection of a non conventional source of water (aquifer recharged unintentionally with raw wastewater) with peracetic acid (PAA) and ultraviolet radiation (UV) as well as nanofiltration (NF) followed by chlorination to produce safe drinking water. The results showed that a dose of 2 mg/L PAA was needed to eliminate total and faecal coliforms. For UV light, a dose of 12.40 mWs/cm2 reduced total and faecal coliforms below the detection limit. On the other hand, chlorine demand of water before NF was 1.1–1.3 mg/L with a trihalomethane formation potential (THMFP) of 118.62 μg/L, in contrast with chlorination after NF where the demand was 0.5 mg/L and THMFP of 17.64 μg/L. The recommended scheme is nanofiltration + chlorination.
Research Note: Effects of Resilience Training on the Reduction of Stress and Depression among Dutch Workers
Authors: Steensma Herman , Heijer Monique Den , Stallen Valerie
Published: March 2008

This study tests the effects of a resilience training program on (former) employees who are suffering from protracted illness due to stress or burnout. Subjects ( N = 20) suffering from long-term illness caused by workstress participated in a six-month training program. The program consists of four stages. In all, nine instruments were used to strengthen the resilience of trainees (e.g., meditation, rational insights, etc.). To evaluate the results of the training, trainees filled out two questionnaires (Utrecht Coping List and Beck's Depression Inventory) at four points in time, before, during, and at the end of the training period. Trainees demonstrated improvements on effective coping styles and made less use of avoidance and passive reactions. Most trainees were reintegrated successfully in organizations. It is concluded that the resilience training program may be very useful in attempts to reduce the number of (ex-)employees suffering from full or partial disability. Burnout may be cured and/or prevented by participation in the resilience program.
Study of superconducting state parameters of amorphous metals by a pseudopotential theory
Authors: Vora Aditya
Published: March 2008

The theoretical computation of the superconducting state parameters (SSP) viz; electron-phonon coupling strength λ, Coulomb pseudopotential μ
*, transition temperature T
c, isotope effect exponent α and effective interaction strength N
O
V of some monovalent (Cu and Au), divalent (Ca, Sr, Ba, αHg, βHg and Ra) and polyvalent (Lu, Rh, Sc, Y, La, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Ac, Th, Hf, Ru, Os, Ir, V, Ta, Pa, Cr, Mo, U, Re, Np and Pu) amorphous metals based on the different groups of the periodic table have been carried out for the first time using the well known Ashcroft’s empty core (EMC) model pseudopotential. Herein, we have employed five different types of local field correction functions proposed by Hartree (H), Taylor (T), Ichimaru-Utsumi (IU), Farid et al. (F) and Sarkar et al. (S) to study the exchange and correlation effects on the present investigations. A very strong influence of all the exchange and correlation functions have been observed in the present study. Our results are in fair agreement with documented theoretical as well as experimental data. A strong dependency of the SSP of amorphous metals on the valency Z was found.
Structural stability of TiO and TiN under high pressure
Authors: Chauhan Raja , Singh Sadhna , Singh Ram
Published: March 2008

The high pressure phase transition and elastic behavior of Transition Metal Compounds (TiO and TiN) which crystallize in NaCl-structure have been investigated using the three body potential model (TBPM) approach. These interactions arise due to the electron-shell deformation of the overlapping ions in crystals. The TBP model consists of a long range Coulomb, three body interactions, and the short-range overlap repulsive forces operative up to the second neighboring ions. The authors of this paper estimated the values of the phase transition pressures, associated volume collapses, and elastic constants, all of which were found to be closer to available experimental data than other calculations. Thus, the TBPM approach promises to predict the phase transition pressure and pressure variations of elastic constants of Transition Metal compounds.
Structural and electrical properties of KCa2Nb5O15 ceramics
Authors: Behera Banarji , Nayak Pratibindhya , Choudhary Ram
Published: March 2008

A polycrystalline sample of KCa2Nb5O15 with tungsten bronze structure was prepared by a mixed oxide method at high temperature. A preliminary structural analysis of the compound showed an orthorhombic crystal structure at room temperature. Surface morphology of the compound shows a uniform grain distribution throughout the surface of the sample. Studies of temperature variation on dielectric response at various frequencies show that the compound has a transition temperature well above the room temperature (i.e., 105°C), which was confirmed by the polarization measurement. Electrical properties of the material have been studied using a complex impedance spectroscopy (CIS) technique in a wide temperature (31–500°C) and frequency (102–106 Hz) range that showed only bulk contribution and non-Debye type relaxation processes in the material. The activation energy of the compound (calculated from both the loss and modulus spectrum) is same, and hence the relaxation process may be attributed to the same type of charge carriers. A possible ‘hopping’ mechanism for electrical transport processes in the system is evident from the modulus analysis. A plot of dc conductivity (bulk) with temperature variation demonstrates that the compound exhibits Arrhenius type of electrical conductivity.
Pool-Frenkel effect and high frequency dielectric constant determination of semiconducting P2O5-Li2MoO4-Li2O and P2O5-Na2MoO4-Na2O bulk glasses
Authors: Souri Dariush , Elahi Mohammad , Yazdanpanah Mohammad
Published: March 2008

The ternary 70P2O5-10Li2MoO4-20Li2O and 70P2O5-10Na2MoO4-20Na2O glasses, prepared by the press-melt quenching technique, were studied at temperatures between 298 and 418 K for their high dc electric field properties. For the above purpose, the effect of a strong electric field on the dc conduction of these amorphous bulk samples was investigated using the gap-type electrode configuration. At low electric fields, the current-voltage (I — V) characteristics have a linear shape, while at high electric fields (> 103 V/cm), bulk samples show nonlinear effects (nonohmic conduction). Current-voltage curves show increasing departure from Ohm’s law with increasing current density, leading to critical phenomena at a maximum voltage (threshold voltage), known as switching (switch from a low-conduction state to a higher-conduction state at threshold voltage). The Pool-Frenkel high-field effect was observed at electrical fields of about 103–104 V/cm; then the lowering factor of the potential barrier, the high frequency dielectric constant, and the refractive index of these glasses were determined.
The ferrimagnetic phase of the Blume-Emery-Griffiths model on the cellular automaton
Authors: Seferoğlu Nurgül , Kutlu Bülent
Published: March 2008

The Blume-Emery-Griffiths model is simulated using the cooling algorithm which is improved from the Creutz cellular automaton (CCA) under periodic boundary conditions. The simulations are carried out on a simple cubic lattice at K/J = −1.5 in the range of −3.5 < D/J < 0.5, with J and K representing the nearestneighbour bilinear and biquadratic interactions, D being the single-ion anisotropy parameter. The phase diagram characterizing phase transition of the model is obtained. We found different kinds of phase transitions between the ferromagnetic, quadrupolar, staggered quadrupolar and ferrimagnetic phases for K/J = −1.5. In particular, the region of the phase diagram containing a ferrimagnetic phase is explored and compared to those obtained by other methods. The simulations confirm that the ferrimagnetic phase occurs in the narrow interval −3.006 ≤ D/J < −3. This result is in a good agreement with Monte Carlo renormalization group and closer to the cluster variation method result than the mean field approximation result.
Ambient temperature or moderately cooled semiconductor hot electron bolometer for mm and sub-mm regions
Authors: Dobrovolsky V. , Sizov F. , Kamenev Y. , Smirnov A.
Published: March 2008

A model of semiconductor hot electron bolometer (SHEB), in which electromagnetic radiation heats only electrons in narrow-gap semiconductor without its lattice slow-response heating, is considered. Free carrier heating changes the generation-recombination processes that are the reason of semiconductor resistance rise. It is estimated, that Hg0.8Cd0.2Te detector noise equivalent power (NEP) for mm and sub-mm radiation wavelength range can reach NEP ∼10−11 W at Δf = 1 Hz signal gain frequency bandwidth. Measurements performed at electromagnetic wave frequencies v = 36, 39, 55, 75 GHz, and at 0.89 and 1.58 THz too, with non-optimized Hg0.8Cd0.2Te antenna-coupled bolometer prototype confirmed the basic concept of SHEB. The experimental sensitivity Sv ∼2 V/W at T = 300 K and the calculated both Johnson-Nyquist and generation-recombination noise values gave estimation of SHEB NEP ∼3.5 × 10−10 W at the band-width Δf = 1 Hz and v = 36 GHz.
Detection and characterization of breast tumours by time-domain scanning optical mammography
Authors: Rinneberg H. , Grosenick D. , Moesta K. , Wabnitz H. , Mucke J. , Wübbeler G. , Macdonald R. , Schlag P.
Published: March 2008

The paper gives a short overview of various methods of optical mammography, emphasizing scanning time-domain mammography. The results of a clinical study on time-domain optical mammography are reviewed, comprising 154 patients carrying a total of 102 carcinomas validated by histology. A visibility score attributed to each carcinoma as qualitative measure of tumour detectability indicates acceptable sensitivity but poor specificity for discrimination between malignant and benign lesions. Likewise, a multi-variate statistical analysis yields sensitivity and specificity between 80% and 85% for tumour detection and discrimination with respect to normal (healthy) breast tissue, but values less than 70% for discrimination between malignant and benign breast lesions, being too low to be of clinical relevance. For 87 of the 88 tumours detected retrospectively in both projection optical mammograms, optical properties and tissue parameters were derived based on the diffraction of photon density waves by a spherical inhomogeneity as forward model. Following injection of a bolus of indocyanine green as non-targeted absorbing contrast agent, dynamic contrast-enhanced time-domain optical mammography was carried out on a small number of patients, but no differences in wash-out kinetics of indocyanine green between tumours and healthy breast tissue were observed.
Infrared sensors in spacecraft that monitor planet Earth
Authors: Norton P.
Published: March 2008

Infrared sensors provide a backbone for many of the instruments flown by National Aeronautics and Space Administration (NASA) and National Oceanic and Atmospheric Administration (NOAA) that monitor conditions on planet Earth. This paper gives an overview of some of those missions and infrared sensors used in the spacecraft instruments. Basic properties of the sensors are described and the evolution of sensor complexity is presented by example. Future trends pointing towards more sophisticated sensors in the future are discussed.
On the Alexandroff decomposition theorem
Authors: Avallone Anna , Barbieri Giuseppina , Vitolo Paolo
Published: March 2008

We prove an Alexandroff decomposition type theorem, which extends a decomposition theorem proved in [de LUCIA, P.—MORALES, P.: Decomposition of group-valued measures in orthoalgebras, Fund. Math. 158 (1998), 109–124].
Experimental and modeling study of catalytic reaction of glucose isomerization: Kinetics and packed‐bed dynamic modeling
Authors: Dehkordi Asghar Molaei , Safari Iman , Karima Muhammad M.
Published: March 2008

The kinetics and equilibrium of isomerization reaction of D‐glucose to D‐fructose have been investigated using a commercial immobilized glucose isomerase (IGI), Sweetzyme type IT®, in a batch stirred‐tank reactor. The batch experimental data were used to model the reaction kinetics using the well‐known Michaelis–Menten rate expression. The kinetic model was utilized in a dynamic‐mathematical model for a packed‐bed reactor to predict the concentration profiles of D‐glucose and D‐fructose within the reactor. The experimental results for the fractional conversion of D‐glucose in the packed‐bed reactor of IGI catalyst indicated that the model prediction of the transient and steady‐state performance of the packed‐bed reactor was satisfactory and as such could be used in the design of a fixed‐bed IGI catalytic reactor. Moreover, the influences of axial mixing term, particle Re number, and axial peclet number (Pea) on the performance capability of the packed‐bed reactor of IGI catalyst were investigated. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Drops, slugs, and flooding in polymer electrolyte membrane fuel cells
Authors: Kimball Erin , Whitaker Tamara , Kevrekidis Yannis G. , Benziger Jay B.
Published: March 2008

The process of flooding has been examined with a single‐channel fuel cell that permits direct observation of liquid water motion and local current density. As product water flows through the largest pores in the hydrophobic GDL, drops detach from the surface, aggregate, and form slugs. Flooding in polymer electrolyte membrane (PEM) fuel cells occurs when liquid water slugs accumulate in the gas flow channel, inhibiting reactant transport. Because of the importance of gravity, we observe different characteristics with different orientations of the flow channels. Liquid water may fall away from the GDL and be pushed out with minimal effect on the local current density, accumulate on the GDL surface and cause local fluctuations, or become a pulsating flow of liquid slugs and cause periodic oscillations. We show that flooding in PEM fuel cells is gravity‐dependent and the local current densities depend on dynamics of liquid slugs moving through the flow channels. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Experimental study on a new process of producing hydrogen in consumption of water and coal
Authors: Zhou Yaping , Jia Chunxiao , Zhang Yu , Liu Chunfeng , Huang Desheng , Sun Yan , Zhou Li
Published: March 2008

A new process of producing pure H2 in consumption of H2O and carbon is presented. It contains three reactions: (1) Steam reacts with FeO at 800°C generating pure H2 and Fe3O4/Fe2O3; (2) Fe3O4/Fe2O3 are reduced to FeO by CO at same temperature while CO changes to CO2; (3) The produced CO2 reacts with carbon generating CO at 900°C. The net product of the process is H2 and CO. Theoretical energy gain of the new process is much higher than 1.0 and is energetically more than autarky. Some CO satisfies the process energy requirement and the surplus CO outputs as by‐product. Experiments proved the feasibility of the process with indication of the importance to control the extent of reduction. The prominent advantages embedded allow the process applied in large‐scale to trade coal for hydrogen. As such, instead of burning coal, hydrogen is burnt wherever energy is consumed. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Cross‐sectional analysis of long bones, occupational activities and long‐distance trade of the Classic Maya from Xcambó—Archaeological and osteological evidence
Authors: Maggiano Isabel S. , Schultz Michael , Kierdorf Horst , Sosa Thelma Sierra , Maggiano Corey M. , Tiesler Blos Vera
Published: March 2008

Xcambó is a Classic period Maya site (250–700 AD) situated on the northern coast of Yucatan, Mexico. Archaeological evidence suggests that the site began as a salt production center but adopted a more administrative role as a commercial port in the Late Classic period. Economic growth, depending on its magnitude, could have affected the daily occupations of Xcambó's inhabitants. However, this is difficult to infer from the archaeological record. The aim of this study was to directly evaluate this possibility through skeletal analysis. Since diaphyseal robusticity and shape are predominantly influenced by mechanical loading history, long bone cross‐sections can be used to access activity patterns. To this end, humeri and femora of 47 male and 35 female adult specimens from two Xcambó population samples were scrutinized. Our analysis satisfies general archaeological expectations and provides additional information on the population's physical response to economic growth. Decreasing robusticity and femoral anterior–posterior rigidity indicate an overall decrease in physical workload and mobility, concomitant with the site's increasing administrative function. We also observed a significant decrease in sexual dimorphism, possibly attributable to the differential response of male and female physical work spheres during socioeconomic change. In general, our findings suggest even nonsubsistence based socioeconomic change can significantly affect the bone structure of a population, rendering activity analysis an important aspect of the reconstruction of living conditions of past populations. Am J Phys Anthropol, 2008. © 2008 Wiley‐Liss, Inc.
A Heterogeneous‐Catalyst‐Based, Microwave‐Assisted Protocol for the Synthesis of 2,2′‐Bipyridines
Authors: Moore Lucas R. , Vicic David A.
Published: March 2008

A new method of preparing 2,2′‐bipyridines with short reaction times by using microwave assistance and heterogeneous catalysts has been developed. With a Negishi‐like protocol, it was found that Ni/Al2O3–SiO2 afforded 2,2′‐bipyridine products in up to 86 % yield in 1 h. Palladium supported on alumina also provided yields of 2,2′‐bipyridines comparable to those seen for homogeneous PEPPSITM (1,3‐diisopropylimidazol‐2‐ylidene)(3‐chloropyridyl)palladium(II)dichloride) and tetrakis(triphenylphosphanyl)palladium complexes.