bluuebunny/crossref_metadata_2025 huggingface dataset:
Pressure gradients, shell-crossing singularities and acoustic oscillations – application to inhomogeneous cosmological models
Authors: Bolejko K. , Lasky P. D.
Published: October 2008

Inhomogeneous cosmological models have recently become a very interesting alternative to standard cosmology. This is because these models are able to fit cosmological observations without the need for dark energy. However, due to inhomogeneity and pressureless matter content, these models can suffer from shell-crossing singularities. These singularities occur when two shells of dust collide with each other leading to infinite values of the density. In this Letter, we show that if inhomogeneous pressure is included then these singularities can be prevented from occurring over the period of structure formation. Thus, a simple incorporation of a gradient of pressure allows for more comprehensive studies of inhomogeneous cosmological models and their application to cosmology.
The Association of Childhood Personality on Sexual Risk Taking During Adolescence
Authors: Atkins Robert
Published: October 2008

Background:  Sexual risk taking during adolescence such as failure to use contraception or condoms is associated with premature parenthood and high rates of sexually transmitted infection. The relation of childhood personality to sexual risk taking during adolescence has been largely unexplored.

Methods:  Using data collected from participants in the Child Sample of the National Longitudinal Survey of Youth (CS‐NLSY) when they were 5 or 6 years of age (time 1) and 17 or 18 years of age (time 2), the relation of childhood personality to sexual risk taking during adolescence was investigated. Maternal ratings of childhood personality were used to derive resiliency, undercontrol, and overcontrol prototypical profile scores for a diverse sample of 1219 child participants from the CS‐NLSY. At time 2, participants reported whether they failed to use oral contraception or condoms during their last sexual intercourse. Logistic regression models were used to investigate the association of personality to sexual risk taking.

Results:  Proximity to the overcontrolled personality prototype at time 1 was associated with a decreased likelihood of sexual risk taking. Age, male gender, and childhood cognitive achievement were also significant predictors of sexual risk taking.

Conclusions:  The findings suggest that children with personality profiles in which internalizing traits are more prominent are less likely than their peers to engage in sexual risk taking during late adolescence. The findings of this study augment previous studies that indicate that personality is an important predictor of development and underscore the importance of conducting research into the processes by which personality influences health behavior.
Musical Works: Ontology and Meta‐Ontology
Authors: Dodd Julian
Published: October 2008

The ontological nature of works of music has been a particularly lively area of philosophical debate during the past few years. This paper serves to introduce the reader to some of the most fertile and interesting issues. Starting by distinguishing three questions – the categorial question, the individuation question, and the persistence question – the article goes on to focus on the first: the question of which ontological category musical works fall under. The paper ends by introducing, and briefly considering, meta‐ontological questions in the ontology of music.
Modality in Language
Authors: Swanson Eric
Published: October 2008

This article discusses some of the ways in which natural language can express modal information – information which is, to a first approximation, about what could be or must be the case, as opposed to being about what actually is the case. It motivates, explains, and raises problems for Angelika Kratzer's influential theory of modal auxiliaries, and introduces a new approach to one important debate about the relationships between modality, evidentiality, context change, and imperative force.
Modeling the effects of El Niño, density‐dependence, and disturbance on harbor seal (Phoca vitulina) counts in Drakes Estero, California: 1997–2007
Authors: Becker Benjamin H. , Press David T. , Allen Sarah G.
Published: October 2008

Abstract

Harbor seal (Phoca vitulina) haul‐out site use may be affected by natural or anthropogenic factors. Here, we use an 11‐yr (1997–2007) study of a seal colony located near a mariculture operation in Drakes Estero, California, to test for natural (El Niño‐Southern Oscillation (ENSO), density‐dependence, long‐term trends) and anthropogenic (disturbance or displacement related to oyster production activities) factors that may influence the use of haul‐out subsites. Annual mariculture related seal disturbance rates increased significantly with increases in oyster harvest (rs= 0.55). Using generalized linear models (GLMs) ranked by best fit and Akaike's Information Criteria, ENSO and oyster production (as a proxy for disturbance/displacement) best explained the patterns of seal use at all three subsites near the mariculture operations, with effects being stronger at the two subsites closest to operations. Conversely, density‐dependence and linear trend effects poorly explained the counts at these subsites. We conclude that a combination of ENSO and mariculture activities best explain the patterns of seal haul‐out use during the breeding/pupping season at the seal haul‐out sites closest to oyster activities.
Effect of pH on Characteristics of Low‐Moisture Mozzarella Cheese during Refrigerated Storage
Authors: Cortez M.A.S. , Furtado M.M. , Gigante M.L. , Kindstedt P.S.
Published: October 2008

ABSTRACT:  This study evaluated the effect of cheese pH on proteolysis, calcium distribution, and functional characteristics of Mozzarella cheese. On 4 occasions, cultured low‐moisture part‐skim Mozzarella cheeses were obtained from a commercial producer on the day after manufacture. Cheese blocks were randomly assigned to 2 groups. One group was shredded, subdivided, and exposed to either ammonia vapor to increase the pH or HCl vapor to decrease the pH. Samples were vacuum packaged, stored at 4 °C, and analyzed for pH 4.6 and 12% TCA soluble nitrogen, apparent viscosity, free oil, and water‐soluble calcium on days 5, 12, 22, and 40. The 2nd group was sectioned into 23‐mm thick slabs and similarly exposed to either ammonia vapor to increase the pH or HCl vapor to decrease the pH. The slabs were vacuum packaged, stored at 4 °C, and analyzed for pH 4.6 and 12% TCA soluble nitrogen, TPA hardness, springiness and cohesiveness, and meltability on days 17, 29, and 41. Data were analyzed by ANOVA according to a spilt‐plot design. Experimentally induced pH differences persisted and significantly affected TPA hardness, apparent viscosity, meltability, and water‐soluble calcium throughout 40 d of storage, but did not affect soluble nitrogen changes. Thus, cheese pH affected functional characteristics and calcium distribution but did not affect proteolysis rates. Higher cheese pH resulted in a harder cheese that required longer aging to develop desirable melting characteristics, whereas cheese with lower pH developed desirable melting characteristics more quickly but had a shorter functional shelf life.
Measurement of High‐Pressure Carbon Dioxide Solubility in Orange Juice, Apple Juice, and Model Liquid Foods
Authors: Calix T.F. , Ferrentino G. , Balaban M.O.
Published: October 2008

ABSTRACT:  An experimental system to measure the carbon dioxide (CO2) solubility in liquids at different pressures was designed and tested. Pressure and temperature were controlled in the system, and the design assured an accurate measurement of solubility. Experimental measurements of CO2 solubility were performed in pure water, model solutions (ascorbic acid–sugars–water, citric acid–sugars–water), and in commercial orange juice (OJ) and apple juice (AJ), as a function of pressure (7.58 to 15.86 MPa) at constant temperature (40 °C). Aspen simulation software was used to predict the solubility in simple cases. All experimental results and predictions from simulations were compared with literature data. Measurements of CO2 solubility in pure water were not significantly different than the literature. CO2 solubility (g/100 g of liquid) results in the model liquids and in the juices were lower than for pure water, due to the presence of solutes. The software simulation was able to predict the CO2 solubility in the model systems at low pressures.
Relating Sensory Descriptors to Volatile Components in Flavor of Specialty Rice Types
Authors: Limpawattana M. , Yang D.S. , Kays S.J. , Shewfelt R.L.
Published: October 2008

ABSTRACT:  Flavor is a key factor contributing to consumer acceptance and repeat purchase of rice. Plant breeders focus on production yield and ignoring quality traits because there are no readily useable tools to evaluate quality. A systematic approach is needed for rice breeders to select rice with favorable flavor traits. Descriptive sensory analysis combined with chemical analysis provided an insight of sensory significance to interpret chemical data for a better understanding approach of rice flavor. This study was aimed to develop prediction models for sensory descriptors based on the volatile components derived from the gas chromatography–olfactometry (GC–O) that would be useful to help select rice cultivars containing a satisfactory flavor to produce improved quality in rice breeding programs. Thirteen Korean specialty rice samples were evaluated for their flavor components using descriptive analysis and GC–O. Nineteen aroma attributes in cooked specialty rice samples were evaluated by 8 trained panelists and statistically correlated to the concentration of aroma‐active compounds derived from GC–O analysis. Prediction models were developed for most aroma descriptors including popcorn, cooked grain, starchy, woody, smoky, grain, corn, hay‐like, barny, rancid, waxy, earthy, and sweet aroma using stepwise multiple linear regression. (E,E)‐2, 4‐decadienal, naphthalene, guaiacol, (E)‐2‐hexenal, 2‐acetyl‐1‐pyrroline, 2‐heptanone contributed most to these sensory attributes. These models help provide a quantitative link between sensory characteristics of commercial rice samples and aroma volatile components desirable in developing a rapid analytical method for use by rice breeders to screen progeny for superior flavor quality.
Cholesterol‐Lowering Properties of Whole Cowpea Seed and Its Protein Isolate in Hamsters
Authors: Frota K.M.G. , Mendonça S. , Saldiva P.H.N. , Cruz R.J. , Arêas J.A.G.
Published: October 2008

ABSTRACT:  Hypercholesterolemic hamsters were fed for 4 wk on diets rich in saturated fatty acids and cholesterol, differing only in protein source (20 %): casein (control group, HC), whole cowpea seed (HWS), and cowpea protein isolate (HPI). Hamsters fed on HWS and HPI presented significant reductions in plasma total cholesterol and non‐HDL cholesterol. HPI and HC presented similar protein digestibility, which were significantly higher than that of HWS. Animals fed on HWS presented significantly higher levels of bile acids and cholesterol in feces than did the animals fed on casein or HPI diets. Histological analyses of the liver showed that HC diet resulted in steatosis widely distributed throughout the hepatic lobule, while HWS and HPI diets promoted reductions in liver steatosis. The effectiveness of HWS for modulating lipid metabolism was greater than that of HPI, as measured by plasma cholesterol reduction and liver steatosis.
Ice Recrystallization Inhibition in Ice Cream by Propylene Glycol Monostearate
Authors: Aleong J.M. , Frochot S. , Goff H.D.
Published: October 2008

ABSTRACT:  The effectiveness of propylene glycol monostearate (PGMS) to inhibit ice recrystallization was evaluated in ice cream and frozen sucrose solutions. PGMS (0.3%) dramatically reduced ice crystal sizes in ice cream and in sucrose solutions frozen in a scraped‐surface freezer before and after heat shock, but had no effect in quiescently frozen solutions. PGMS showed limited emulsifier properties by promoting smaller fat globule size distributions and enhanced partial coalescence in the mix and ice cream, respectively, but at a much lower level compared to conventional ice cream emulsifier. Low temperature scanning electron microscopy revealed highly irregular crystal morphology in both ice cream and sucrose solutions frozen in a scraped‐surface freezer. There was strong evidence to suggest that PGMS directly interacts with ice crystals and interferes with normal surface propagation. Shear during freezing may be required for its distribution around the ice and sufficient surface coverage.
Differences in detecting blasts between ADVIA 2120 and Beckman‐Coulter LH750 hematology analyzers
Authors: SHELAT S. G. , CANFIELD W. , SHIBUTANI S.
Published: October 2008

The complete blood count is often used as a screening tool to detect hematologic abnormalities in the peripheral blood. In patients with suspected or known leukemia, blast cells serve as an indicator of disease pathology. We compared the analytical performance of the Siemens ADVIA 2120 to the Beckman‐Coulter LH750 in the detection of blasts. In the study, 390 blood samples were analyzed from a general hospital population, which included oncology patients. The presence of blasts, as indicated by the analyzers’ flags, was compared with the results of a manual differential (regarded as the reference method). The ADVIA 2120 demonstrated 100% sensitivity at detecting blasts compared with 62% using the LH750. This improved sensitivity came at the expense of a lower specificity (49%vs. 86%). The effect of the false‐positive and false‐negative samples on the laboratory’s manual review was partially (false‐positive) or completely (false‐negative) mitigated by triggering of other criteria. Detecting blasts in the peripheral blood depends on the performance characteristics of the hematology analyzer, in conjunction with the stringency of the laboratory’s manual review criteria.
A Longer Course of Varenicline Therapy Improves Smoking Cessation Rates
Authors: Lee John H. , Jones Philip G. , Bybee Kevin , O’Keefe James H.
Published: October 2008

Smoking exerts strong dose‐dependent increases in cardiovascular risk and mortality, and quitting can profoundly decrease these risks. Varenicline attenuates nicotine addiction by reducing withdrawal symptoms and cravings. A meta‐analysis performed addressed whether a longer duration of varenicline is associated with better abstinence rates than shorter courses of treatment. For this meta‐analysis, a literature search was performed to identify randomized controlled trials investigating the efficacy of the smoking cessation agent varenicline. The association between abstinence and duration of treatment was analyzed using fixed‐effect meta‐regression. Five randomized controlled trials were identified and included in this meta‐analysis. A highly significant relationship (P<.001) was found between the length of exposure to varenicline and abstinence rate. Cessation rates were approximately twice as high with varenicline treatment of 24 weeks compared to 6 weeks. In conclusion, a meta‐analysis of randomized controlled trials suggests that longer duration of varenicline therapy improves long‐term abstinence rates.
Use of Angiotensin‐Converting Enzyme Inhibitor/Angiotensin Receptor Blocker Therapy to Reduce Cardiovascular Events in High‐Risk Patients: Part 2
Authors: Bommer William J.
Published: October 2008

As presented previously in Part 1 of this 2‐part article, many long‐term clinical trials provide overwhelming evidence of the benefits of angiotensin‐converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) across the cardiovascular continuum. Trials also indicate additive or synergistic effects of combination therapy in renal disease and heart failure. Part 2, which is presented here, discusses the extensive interaction of the renin‐angiotensin system (RAS) with the cellular and molecular pathophysiology of cardiovascular disease and the cross‐continuum effects of ARBs and ACE inhibitors, which raises the possibility that RAS inhibition can offer protection in high‐risk patients who do not have symptoms. Although trial evidence supports the effectiveness of monotherapy, the benefits of combined ACE inhibitor/ARB therapy in high‐risk patients await confirmation. Ongoing clinical research will provide new and important information regarding the efficacy of specific combination (ACE inhibitor/ARB) therapies.
High shear enrichment improves the performance of the anodophilic microbial consortium in a microbial fuel cell
Authors: Pham Hai The , Boon Nico , Aelterman Peter , Clauwaert Peter , De Schamphelaire Liesje , Van Oostveldt Patrick , Verbeken Kim , Rabaey Korneel , Verstraete Willy
Published: October 2008

In many microbial bioreactors, high shear rates result in strong attachment of microbes and dense biofilms. In this study, high shear rates were applied to enrich an anodophilic microbial consortium in a microbial fuel cell (MFC). Enrichment at a shear rate of about 120 s−1 resulted in the production of a current and power output two to three times higher than those in the case of low shear rates (around 0.3 s−1). Biomass and biofilm analyses showed that the anodic biofilm from the MFC enriched under high shear rate conditions, in comparison with that under low shear rate conditions, had a doubled average thickness and the biomass density increased with a factor 5. The microbial community of the former, as analysed by DGGE, was significantly different from that of the latter. The results showed that enrichment by applying high shear rates in an MFC can result in a specific electrochemically active biofilm that is thicker and denser and attaches better, and hence has a better performance.
Interplay of metagenomics and in vitro compartmentalization
Authors: Ferrer Manuel , Beloqui Ana , Vieites José María , Guazzaroni María Eugenia , Berger Ilana , Aharoni Amir
Published: October 2008

In recent years, the application of approaches for harvesting DNA from the environment, the so‐called, ‘metagenomic approaches’ has proven to be highly successful for the identification, isolation and generation of novel enzymes. Functional screening for the desired catalytic activity is one of the key steps in mining metagenomic libraries, as it does not rely on sequence homology. In this mini‐review, we survey high‐throughput screening tools, originally developed for directed evolution experiments, which can be readily adapted for the screening of large libraries. In particular, we focus on the use of in vitro compartmentalization (IVC) approaches to address potential advantages and problems the merger of culture‐independent and IVC techniques might bring on the mining of enzyme activities in microbial communities.
Mechanism of action of and resistance to quinolones
Authors: Fàbrega Anna , Madurga Sergi , Giralt Ernest , Vila Jordi
Published: October 2008

Fluoroquinolones are an important class of wide‐spectrum antibacterial agents. The first quinolone described was nalidixic acid, which showed a narrow spectrum of activity. The evolution of quinolones to more potent molecules was based on changes at positions 1, 6, 7 and 8 of the chemical structure of nalidixic acid. Quinolones inhibit DNA gyrase and topoisomerase IV activities, two enzymes essential for bacteria viability. The acquisition of quinolone resistance is frequently related to (i) chromosomal mutations such as those in the genes encoding the A and B subunits of the protein targets (gyrA, gyrB, parC and parE), or mutations causing reduced drug accumulation, either by a decreased uptake or by an increased efflux, and (ii) quinolone resistance genes associated with plasmids have been also described, i.e. the qnr gene that encodes a pentapeptide, which blocks the action of quinolones on the DNA gyrase and topoisomerase IV; the aac(6′)‐Ib‐cr gene that encodes an acetylase that modifies the amino group of the piperazin ring of the fluoroquinolones and efflux pump encoded by the qepA gene that decreases intracellular drug levels. These plasmid‐mediated mechanisms of resistance confer low levels of resistance but provide a favourable background in which selection of additional chromosomally encoded quinolone resistance mechanisms can occur.
tmRNA of Streptomyces collinus and Streptomyces griseus during the growth and in the presence of antibiotics
Authors: Palečková Petra , Bobek Jan , Mikulík Karel
Published: October 2008

Streptomycetes are soil microorganisms with the potential to produce a broad spectrum of secondary metabolities. The production of antibiotics is accompanied by a decrease in protein synthesis, which raises the question of how these bacteria survived the transition from the primary to the secondary metabolism. Translating ribosomes incapable to properly elongate or terminate polypeptide chain activate bacterial trans‐translation system. Abundance and stability of the tmRNA during growth of Streptomyces collinus and Streptomyces griseus producing kirromycin and streptomycin, respectively, was analysed. The level of tmRNA is mostly proportional to the activity of the translational system. We demonstrate that the addition of sub‐inhibitory concentrations of produced antibiotics to the cultures from the beginning of the exponential phase of growth leads to an increase in tmRNA levels and to an incorporation of amino acids into the tag‐peptides at trans‐translation of stalled ribosomes. These findings suggest that produced antibiotics induce tmRNA that facilitate reactivation of stalled complex of ribosomes and maintain viability. The effect of antibiotics that inhibit the cell‐wall turnover, DNA, RNA or protein synthesis on the level of tmRNA was examined. Antibiotics interfering with ribosomal target sites are more effective at stimulation of the tmRNA level in streptomycetes examined than those affecting the synthesis of DNA, RNA or the cell wall.
Social Control Behavior: The Effects of Social Situations and Personal Implication on Informal Social Sanctions
Authors: Chekroun Peggy
Published: October 2008

Social control is the generic term used to refer to reactions to counter‐normative behaviors and to informal social sanctions that can be attributed to deviant individuals. This review of theories and experimental findings addresses the determinants of social control reactions. First, we examine researches in experimental social psychology that show how people's reactions can be inhibited by the presence of others; a phenomenon known as the ‘Bystander effect’. Next, we examine the extent to which group membership factors affect social control. According to the ‘Black Sheep effect’, people are more severe with a deviant when they share their social identity than when he is a member of an out‐group. Even though these processes appear as good predictors for social control reactions, other findings highlight that social control and the previous processes could be associated to self‐related motivations that are encouraging people to defend themselves through the protection of their group's norms.
Social Movements and New Media
Authors: Loader Brian D.
Published: October 2008

This article explores the contention that social movements are a significant social force transforming societies through their engagement with new media, such as the Internet, Web 2.0, and digital communications, which are seen as capable of facilitating new power structures. Utilizing della Porta and Diani's framework, it considers how new media technologies may be shaping the structure, identity, opportunity, and protest dimensions of social movements. It concludes by suggesting that new media does offer important opportunities for cost‐effective networking, interpretive framing, mobilization, and repertoires of protest action. However, their adoption does not represent the creation of entirely new virtual social movements but rather a new means of providing existing social movement organisations, local activist networks, and street‐level protest with a trans‐national capacity to collaborate, share information, and communicate with a wider audience. Such new media‐enabled social action is both more congruent with a politics of identity but may also increasingly be competing within a media environment saturated by user‐generated content.
Understanding Employment Discrimination: A Multilevel Approach
Authors: Hirsh C. Elizabeth , Cha Youngjoo
Published: October 2008

This paper reviews recent research on employment discrimination on the basis of sex, race, and ethnicity in US work establishments. Unlike blatant discrimination of the past, contemporary discrimination is typically more subtle, often unintentional, and develops in relationship to the social context in which it is embedded. Focusing on this covert and dynamic nature of discrimination, we review recent research that identifies factors at the individual, workplace, and societal level that contribute to variation in sex and race discrimination across employment contexts. At each level, we conceptually distinguish between factors that influence employers’ sex and race biases and factors that affect potential victims’ capacity to identify discriminatory experiences at work.
Feminist and Gender Media Studies: A Critical Overview
Authors: Mendes Kaitlynn , Carter Cynthia
Published: October 2008

This paper offers a general overview of past, current, and developing issues and debates in the growing field of gender and feminist media studies. Its main aim is to provide for those who are new to the field, as well as advanced students and researchers, a broad sense of what is now significant and important area of academic research. It engages with the differences and similarities between gender and feminist media studies, gendered communication systems, gendered news production, feminist methodologies and methods in communication research (textual, audience, and production based), the media's role in constructing gender, and gendered and feminist research by specific media form including advertising, magazines, film, television, news, radio, and the Internet and new media. The outline of research presented is not exhaustive; however, it attempts to trace certain significant developments in the field historically, conceptually, methodologically politically and trans‐nationally.
The Information Environment of War
Authors: Gillan Kevin , Pickerill Jenny , Webster Frank
Published: October 2008

This article observes high levels of anxiety about war in the present era, although wars are in decline. It addresses this paradox by distinguishing ideal‐typical features of Industrial and Information War.

Industrial War is fought predominantly between states over territory, harnesses industry and the military, and requires mass mobilisation of people as well as resources.

Information War is the prerogative of a few advanced societies and has emerged in a context that has enabled the extension of market practices on a global scale (with America as a unipolar power). Information War transcends frontiers, is asymmetrical, and itshardside is manifest in digitalised technologies and small professional forces. However, itssoftside evokes the expanded and fast‐changing information environment of globalised media, trans‐national networks and the Internet. Through these, media wars can be experienced intensely by civilians who are otherwise untouched: at once close up and far away. This contributes to heightened consciousness of war, although such spectators are removed from danger. Although interests try to control information flows from and about war, theinformation environmentis huge, shifting and unpredictable. As such, it is impossible to control fully, thereby presenting opportunities for vigoroussymbolic strugglesinvolving anti‐war campaigners and others.
Estimating the Variability and Confidence of Land Use and Imperviousness Relationships at a Regional Scale1
Authors: Ackerman Drew , Stein Eric D.
Published: October 2008

Abstract:  Impervious cover is a commonly used metric to help explain or predict anthropogenic impacts on aquatic resources; often it is used as a surrogate for intensity of human impacts when evaluating effects on aquatic resources. The most common way to estimate imperviousness is based on relationships with land use. Few studies have evaluated how the relationship between impervious surface and land use varies among geographies with different levels of development and between types of imagery used to assign land use type. In this study, we assess variability in estimates of imperviousness based on two locally available land use datasets: one based on aerial imagery (2‐m resolution) and another based on satellite imagery (30‐m resolution). The ranges and variability in imperviousness within land use categories were assessed at several spatial scales, including within counties, between counties, and between watersheds. Results indicate that there was considerable variability for all developed land use types. Estimated impervious cover often varied over a range of 20‐40% points within a land use category. Furthermore, there were clear spatial patterns both between and within counties, with impervious cover for a given land use type being higher near the urban centers and lower at the margins of development. Estimates of imperviousness for 12 study watersheds indicated that variability increased with increasing watershed development, making it difficult to confidently set management or regulatory targets based on impervious cover. This study suggests that locally derived, high resolution satellite or aerial imagery should be used to estimate imperviousness when a high level of accuracy and precision is required for regulatory or management decisions. Furthermore, the error associated with impervious land use relationships should be accounted for when using impervious cover in runoff or water quality models, or when making management decisions regarding stream health.
Relationship between ocular pulse amplitude and systemic blood pressure measurements
Authors: Grieshaber Matthias C. , Katamay Robert , Gugleta Konstantin , Kochkorov Asan , Flammer Josef , Orgül Selim
Published: October 2008

Purpose:  This study aimed to determine whether ocular pulse amplitude (OPA) measured with dynamic contour tonometry (DCT) is related to systemic blood pressure (BP) parameters.

Methods:  Blood pressure was measured continuously and simultaneously with OPA in one randomly selected eye in 29 healthy subjects. Systemic parameters of interest were: systolic and diastolic BPs and their difference (BP amplitude), and left ventricle ejection time (LVET; defined as the time between the diastolic trough and the incisural notch in the BP curve). In addition, the axial length (AL) of the eye was measured. Associations between OPA, AL and systemic cardiovascular parameters were analysed in a multivariate regression model.

Results:  Measurements of OPA ranged from 1.0 mmHg to 4.9 mmHg (mean 2.3 ± 0.9 mmHg, median 1.9 mmHg). In a univariate analysis with one predictor at a time, means of intraocular pressure (IOP) (p = 0.008), AL (p = 0.046) and LVET (p = 0.037) were significantly correlated with OPA, whereas systolic and diastolic BPs and their amplitude were not. A multiple linear regression analysis showed that mean IOP (p < 0.005), AL (p = 0.01) and LVET (p = 0.002) all independently contributed to OPA.

Conclusions:  The OPA readings measured with DCT in healthy subjects were not related to BP levels and amplitude. It seems that the OPA strongly depends on the time−course of the cardiac contraction. Regulating mechanisms in the carotid system as well as scleral rigidity may be responsible for dampening the direct effect of BP variations.
Mortality after uveal and conjunctival melanoma: which tumour is more deadly?
Authors: Kujala Emma , Tuomaala Seppo , Eskelin Sebastian , Kivelä Tero
Published: October 2008

Purpose:  We aimed to model and compare mortality rates for uveal melanoma (UM) and conjunctival melanoma (CM) by adjusting for differences in tumour size and local recurrence.

Methods:  Population‐based mortality data for 240 and 85 patients with primary UM and CM and 91 and 23 patients with disseminated UM and CM, respectively, were compared with cumulative incidence analysis. Cox proportional hazards multivariate regression with time‐dependent variables was used to adjust for differences in tumour diameter, thickness and recurrence rates.

Results:  The 10‐year cumulative incidences of metastatic death from UM and CM were 39% (95% confidence interval [CI] 33–45) and 32% (95% CI 21–44), respectively. After adjusting for tumour size, risk of death from CM was higher than from UM (hazard ratio [HR] 1.9; p = 0.039). Additional adjustment for more frequent local recurrence of CM diminished the difference (HR 1.5; p = 0.25). Survival periods after systemic metastasis of UM and CM were comparable (median 8 months).

Conclusions:  Clinical observations show longer survival after primary CM than after primary UM. This reflects the smaller average size of CM. However, a primary CM of a given size is more deadly than a UM of equivalent size because primary CM tends to recur after treatment and, possibly, because additional lymphatic dissemination occurs with CM.
LIQUIDITY AND THE INFORMATIONAL EFFICIENCY OF AFRICAN STOCK MARKETS
Authors: Smith Graham
Published: October 2008

The hypothesis that a stock market price index follows a random walk is tested for 11 African stock markets, Botswana, Côte d’Ivoire, Egypt, Ghana, Kenya, Mauritius, Morocco, Nigeria, South Africa, Tunisia and Zimbabwe using joint variance ratio tests with finite‐sample critical values, over the period beginning in January 2000 and ending in September 2006. The iid random walk hypothesis is rejected in all 11 markets. In four stock markets, Egypt, Nigeria, Tunisia and South Africa, weekly returns are a martingale difference sequence. Liquidity is an important factor which contributes to whether a stock market follows a random walk.
FINANCIAL AND MONETARY AUTONOMY AND INTERDEPENDENCE BETWEEN SOUTH AFRICA AND THE OTHER SACU COUNTRIES
Authors: Aziakpono Meshach Jesse
Published: October 2008

The paper uses cointegration and error correction modelling techniques together with tests of weak exogeneity, and monthly interest rates for the period 1990 to 2005, to examine the degree of financial and monetary autonomy and interdependence between South Africa and the other Southern African Customs, Union (SACU) countries. The results reveal a high level of dependence of the other SACU countries' financial systems on South Africa's financial system, which suggests that a monetary unification with a single central bank (South African Reserve Bank) and monetary policy for the union is feasible.
CORRUPTION AND THE COMPOSITION OF TAX REVENUE IN MIDDLE EAST AND AFRICAN ECONOMIES1
Authors: Thornton John
Published: October 2008

Regression results from a panel of 53 Middle East and African economies suggest that corruption has a quite large negative and statistically significant impact on tax revenues, mainly reflecting the impact of corruption on tax collections from social security, and taxes on domestic goods and services and international trade transactions. Policy changes to boost tax revenues might usefully focus on changes in direct taxes and efforts to combat corruption in tax collections should focus on indirect taxes.
ECONOMIC GROWTH, INCOME AND HAPPINESS: AN EXPLORATORY STUDY
Authors: Mahadea D. , Rawat T.
Published: October 2008

The pursuit of high economic growth is considered desirable as it generates an increase in a nation's wealth, income, employment and output. The rising income should enable consumers to purchase more goods and services, which in turn should result in enhanced utility and subjective happiness. Empirical studies suggest that higher income resulting from high rates of economic growth contribute to poverty alleviation and life satisfaction in low income countries. Higher income raises the happiness of the poor. In developed countries, higher income does not seem to “buy” higher happiness, once a threshold level of income is reached. This exploratory study seeks to examine the quantitative and qualitative sources of happiness. A higher absolute level of income is found to be significantly related to subjective happiness. Among the non‐income factors, family togetherness, a good working environment and a higher level of education can contribute to making people happier. Happiness thus involves more than just economic growth and income.
Reactivation of CFBC Ash by Sonic Energy
Authors: Wu Y. , Jia L. , Anthony E. J. , Madrali S. , Hill J. , Hunt L.
Published: October 2008

Hydration and carbonation tests confirm that SESI technology using sonic energy promotes the effective hydration of FBC solids; 70–80% CaO conversion to Ca(OH)2 was easily achievable in a few minutes. In addition, the 75 kW sonic generator, with addition of the grinding medium, was able to produce a highly carbonated residue which could serve as an effective sulphur sorbent or could be landfilled without the current undesirable side reactions such as ettringite production, due to the effective elimination of CaO and Ca(OH)2 in the ash. Over 70% conversion to CaCO3 was achieved in samples that were processed for only 5 min.
Reactivation Studies on Six Fly Ashes From Commercial CFB Boilers
Authors: Wu Y. , Charland J.-P. , Anthony E. J. , Jia L.
Published: October 2008

Six different fly ashes from commercial-scale circulating fluidized bed combustion (CFBC) boilers and the carbon-free residues of these ashes were hydrated with liquid water or steam to determine whether hydration could improve sorbent utilization in these samples under fluidized bed combustion conditions. After hydration, for two fly ashes (FA1 and FA6) and three carbon-free samples (FA2-A, FA3-A and FA6-A), the capacity for taking up SO2 showed limited or medium improvement; however, hydration was evidently ineffective in reactivating the remaining samples. It is believed that the reason samples FA6 and FA6-A show a relatively high improvement in SO2 absorption capacity is that these ashes had a larger particle size than any of the other fly ashes examined here. In general, even for these “reactivatable” fly ashes, reactivation by hydration with either liquid water or steam appeared far less promising than for bed ashes, which have been shown to exhibit significant improvement in sulphur capture during re-sulphation. Hydration, whether by steam or liquid water, is not recommended for fly ash, which has a very limited residence time in the boiler due to its small particle size and instead this paper recommends alternative strategies.
Simulation Studies of Gas-Solid in the Riser of a Circulating Fluidized Bed
Authors: Hussain Ahmad , Nasir Ani Farid , Nordin Darus Amer , Mustafa Azeman , Salema Arshad A.
Published: October 2008

A numerical parametric study was performed on the influence of various riser exit geometries on the hydrodynamics of gas-solid two-phase flow in the riser of a Circulating Fluidized Bed (CFB). A Eulerian continuum formulation was applied to both phases. A two fluid framework has been used to simulate fully developed gas-solid flows in vertical riser. A two dimensional Computational Fluid Dynamics (CFD) model of gas-particle flow in the CFB has been investigated using the code FLUENT. The turbulence was modeled by a k-ε turbulence model in the gas phase. The simulations were done using the geometrical configuration of a CFB test rig at the Universiti Teknologi Malaysia (UTM). The CFB riser column has 265 mm (width), 72 mm (depth) and 2.7 m height. The riser is made up of interchangeable Plexiglas columns. The computational model was used to simulate the riser over a wide range of operating and design parameters. In addition, several numerical experiments were carried out to understand the influence of riser end effects, particle size, gas solid velocity and solid volume fraction on the simulated flow characteristics. The CFD model with a k-ε turbulence model for the gas phase and a fixed particle viscosity in the solids phase showed good mixing behaviour. These results were found to be useful in further development of modeling of gas solid flow in the riser.
Pilot Plant Combustion Tests of Low-Volatile and High-Sulphur Coal for the 55 MWel CFBC Cao Ngan Power Plant, Vietnam
Authors: Loehr Stefan , Barczus Christian , Scherer Viktor , Kluger Frank , Seeber Joachim
Published: October 2008

Circulating Fluid Bed technology has made a rapid and successful entry into power and steam generation marketplace in many countries. As one of the first CFB based power plants in Vietnam the 2 × 55 MWe Cao Ngan project will follow this trend towards clean coal technology. The Cao Ngan CFB boiler is designed to burn a blend of low-volatile, high-sulphur coals from two local mines complying with strict environmental regulations, 500 mg/Nm3 for SO2 and 300 mg/NM3 for NOx. Combustion tests were carried out at the University of Bochum, Institute of Energy Plant Technology, Germany, in a pilot-CFB combustor (100 kWth) in order to check the combustion behaviour and the emission characteristics. In these tests a blend of the two different coals was burned at different temperature levels (830 °C, 860 °C, 890 °C) and at each temperature level the desulphurisation efficiency was tested with two different kind of limestone and different Ca/S-ratios: Furthermore the experimental analysis comprised the determination of the conventional emissions (NOx, CO), ignition characteristics for start-up and part load behaviour. During all tests samples of bed and filter ash were taken for further analysis, e.g. burnout, particle size distribution etc.. Earlier comparable combustions tests carried out in the pilot-CFB combustor and large scale CFB boilers has proven, that the results are transferable to large scale commercial plants: This is valid especially for the major emissions e.g. SO2 and NOx. The current paper will explain the design principles and the basic lay-out of the Cao Ngan CFB boiler. In addition, details of the results of combustion tests carried out in a pilot- CFBC at the University of Bochum, Institute of Energy Plant Technology, Germany, will be presented.
Development of Gas Steam and Power Multi-Generation System
Authors: Fang Mengxiang , Wang Qinghui , Yu Chunjiang , Shi Zhenglun , Luo Zhongyang , Cen Kefa
Published: October 2008

A new system using combined coal gasification and combustion has been developed for clean and high efficient utilization of coal. The coal is first gasified by air/steam or recycle gas and the produced fuel gas is then used for industrial purpose or as a fuel for gas turbine. The char residue from the gasifier is burned in a circulating fluidized bed combustor to generate steam for power generation. A 1MW pilot plant test facility has been erected, which consists of a fluidized bed gasifier, a CFB combustor, flue gas and fuel gas clean and cool system, data acqisition and control system. The primary results show that the system can produce 12–14MJ/Nm3 middle heating value gas by using recycle gas or steam as gasification mediaand bed temperature and solid circulation rate are main parameters. On bases of this, a 25 MW gas steam and power multi-generation system has been designed. In this system, a fluidized bed gasifiers are combined with a 130t/h circulating bed boiler to realize gas and steam cogeneration. The system can produce 7800 M3/h gas with heating value 10–14 Mj/Nm3 and 25 MW Power.
NO and N2O Formation/Decomposition Characteristics During Co-Combustion of Coal With Biomass
Authors: Gani Asri , Naruse Ichiro
Published: October 2008

Co-combustion technologies of coal with biomass have been applied in many practical coal combustion boilers in order to reduce CO2 emission, fuel cost and so forth. Furthermore, the biomass may be able to enhance the combustion performance and to control NOx and N2O emissions since the biomass contains high volatile matter and evolves NH3 as the main volatile N-species. This study focuses on NOx and N2O emission characteristics during co-combustion of coal with biomass. The main results obtained show that emission amount of NO and N2O during co-combustion is relatively more than that during coal combustion. At least, NO behavior can be simulated by the homogeneous reaction scheme relating to NOx even at constant temperature. However, the N2O behavior will be influenced by heterogeneous schemes due to char particles during co-combustion.
The PFBC-CC Generation Power System Used Natural Gas Supplementary Combustion
Authors: Xiao Jun , Zhang Mingyao
Published: October 2008

Based on the first generation PFBC-CC, the natural gas was supplied as a fuel to increase gas turbine inlet temperature, so as to increase net efficiency of power generation. In this paper the analyses of technical, thermal and economic performance for system were carried out under different parameters, including reasonable dust remover inlet temperature, alkali metal concentration in gas before it entering gas turbine and cooling condition in gas turbine combustor. The thermal performance and power-production cost were also studied within the range of reasonable parameters. The results show that the flue gas temperature ≤ 973K at the inlet of hot filter can satisfy the conventional industry-use gas turbine requirement on the alkali metal content and dust content in flue gas. The net efficiency of this system can reach 43.3∼44.6% with sub-critical steam parameter condition and 45∼46.1% with supercritical steam parameter condition. With the increasing of steam parameters, the net efficiency of this system can be increased more. And the consumption of natural gas needs to be controlled in a reasonable level for obtaining the system preferable net efficiency and economics.
Combustion Modeling of CFB Boiler Furnace Based on an Euler-Euler Approach
Authors: Xiao Xianbin , Wang Wei , Yang Hairui , Zhang Hai , Zhang Jiansheng , Liu Qing , Lu Junfu , Yue Guangxi
Published: October 2008

For the better design of large scale CFB boilers, reliable multi-dimensional modeling which can be used to predict the heterogeneous distributions of gas and solid concentration as well as temperature in the furnace is necessary and demanded. A model describing the complex combustion process in a CFB boiler furnace has been developed. The model consists of several essential sub-parts: the hydrodynamics of the bed, combustion of fuel, and overall mass balance of the furnace. In the computational fluid dynamics (CFD) study on hydrodynamics in a CFB boiler, the Euler-Euler approach is used, in which both gas and solid phases are considered as interpenetrating continua with the interaction through drag and energy dissipation caused by particle fluctuation. The constitutive equations for solid phase are derived from the kinetic theory of granular flow (KTGF). Some simplifications of the complicated theoretical equations with empirical correlations are adopted, to save computing time and skip the currently unknown phenomena. Drag coefficient between gas phase and solid phase is modified by the energy-minimization multi-scale (EMMS) principle. A simplified description of reaction process is also adopted. The present model was applied to predict the hydrodynamic and combustion behaviors in a commercial 135 MWe CFB boiler. Some primary results are obtained and discussed in comparison with the measured data. Prediction results agree with the experimental data in general, confirming the correctness of the model. More reliable experiments are needed for the model improvement in the future.