bluuebunny/crossref_metadata_2025 huggingface dataset:
Near‐neutral surface charge and hydrophilicity prevent mineral encrustation of Fe‐oxidizing micro‐organisms
Authors: Saini G. , Chan C. S.
Published: December 2012

Microbial survival in mineralizing environments depends on the ability to evade surface encrustation by minerals, which could obstruct nutrient uptake and waste output. Some organisms localize mineral precipitation away from the cell; however, cell surface properties – charge and hydrophobicity – must also play a role in preventing surface mineralization. This is especially relevant for iron‐oxidizing bacteria (FeOB), which face an encrustation threat from both biotic and abiotic mineralization. We used electron microscopy and surface characterization techniques to study the surfaces of two stalk‐forming neutrophilic FeOB: the marine Zetaproteobacterium Mariprofundus ferrooxydans PV‐1 and the recently isolated freshwater Betaproteobacterium Gallionellales strain R‐1. Both organisms lack detectable iron on cell surfaces. Live and azide‐inhibited M. ferrooxydans PV‐1 cells had small negative zeta potentials (−0.34 to −2.73 mV), over the pH range 4.2–9.4; Gallionellales strain R‐1 cells exhibited an even smaller zeta potential (−0.10 to −0.19 mV) over pH 4.2–8.8. Cells have hydrophilic surfaces, according to water contact angle measurements and microbial adhesion to hydrocarbons tests. Thermodynamic and extended Derjaguin–Landau–Verwey–Overbeek (XDLVO) calculations showed that as low charge causes low electrostatic attraction, hydrophilic repulsion dominates cell–mineral interactions. Therefore, we conclude that surface properties help enable these FeOB to survive in highly mineralizing environments. Given both mineral‐repelling surface properties and the ability to sequester Fe(III) biominerals in an organomineral stalk, these two FeOB have a well‐coordinated system to localize both biotic and abiotic mineral distribution.
Growth, leaf photosynthesis and canopy light use efficiency under differing irradiance and soil N supplies in the forage grass Brachiaria decumbens Stapf
Authors: Gómez S. , Guenni O. , Bravo de Guenni L.
Published: December 2012

Irradiance and soil nitrogen effects on growth, net photosynthesis and radiation use efficiency (RUE) of Brachiaria decumbens were investigated in fertilized and non‐fertilized stands. Three levels of photosynthetic photon flux (PPF: S0 = 100%, S1 = 50% and S2 = 30%) and two N supplies, with (N+) and without (N−), were used. Forage biomass and nutrient accumulation, specific leaf area (SLA), leaf area index (LAI), fractional intercepted photosynthetic photon flux (fPPF), leaf photosynthetic response to light and efficiency of radiation use at leaf (A/Q) and canopy (RUE) levels were measured. Shade effects were mostly independent of soil N. Final yield was decreased by 34% (S1) and 57% (S2). Shade increased SLA (25–46%), so maximum LAI (2·4–3·3) was similar among light regimes. In N− stands, reductions in leaf biomass (14%), SLA (17%) and LAI (27%) were recorded, although forage yield was similar between soil N conditions. Under shade, peaks of A were comparable to those at full light, so A/Q was higher around midday. Derived parameters of the A‐PPF curves were similar between S0 and S2. A maximum fPPF = 0·8 (S0N+, S1N+) was recorded at LAI = 3–4. Under limited sunlight, relatively high RUE (1·6–2·8 g MJ−1) were observed over both soil N conditions. We concluded that B. decumbens had a high plasticity to shade, thus explaining its success under silvopastoral systems.
A comparison of six vetches (Vicia spp.) for developmental rate, herbage yield and seed yield in semi‐arid central Turkey
Authors: Fırıncıoğlu Hüseyin Kansur
Published: December 2012

Six vetches (Vicia spp.), represented by 96 accessions, were evaluated for herbage yield, seed yield and related characters in three consecutive growing seasons (1995‐98) in semi‐arid central Turkey. Data were analysed by multiple statistical procedures: principal component analysis, restricted maximum‐likelihood method and simple linear regression analysis. In the first growing season (Y1), the growing period was curtailed by summer drought, and in the second (Y2) by heavy rainfall. In the third season (Y3), conditions were more temperate. Vicia pannonica ssp. pannonica (Pan) and V. villosa ssp. villosa (Vil) produced more biomass in Y3 than in Y1 and Y2, while V. pannonica ssp. purpurascens (Pur) and V. villosa ssp. dasycarpa (Das) produced more biomass in the wetter Y2. In the shorter growing seasons (Y1 and Y2), the earliness of Pur and Das resulted in high seed yield. V. narbonensis (Nar) in Y3 was particularly sensitive to widely fluctuating air temperatures with the accompanying high rainfall at the vegetative stage, which resulted in vigorous vegetative growth, hindered flowering and reduced seed yield. In V. sativa ssp. sativa (Sat), biomass and seed yield were significantly increased by the longer period of favourable growing weather during Y3. In agricultural practice, Pan and Vil have great potential for herbage production and grazing; Pur, Nar and Sat for grain and straw production; and Das for both hay and grain crops.
Impact of spatial heterogeneity of plant species on herbage productivity, herbage quality and ewe and lamb performance of continuously stocked, perennial ryegrass–white clover swards
Authors: Sharp J. M. , Edwards G. R. , Jeger M. J.
Published: December 2012

The benefits of white clover (Trifolium repens L.) in pastures are widely recognized. However, white clover is perceived as being unreliable due to its typically low content and spatial and temporal variability in mixed (grass‐legume) pastures. One solution to increase the clover proportion and quality of herbage available to grazing animals may be to spatially separate clover from grass within the same field. In a field experiment, perennial ryegrass (Lolium perenne L.) and white clover were sown as a mixture and compared with alternating strips of ryegrass and clover (at 1·5 and 3 m widths), or in adjacent monocultures (strips of 18 m width within a 36‐m‐wide field). Pastures were stocked by ewes and lambs for three 10‐month grazing periods. Over the 3 years of the experiment, spatial separation of grass and clover, compared with a grass–clover mixture, increased clover herbage production, although its proportion in the sward declined through time (0·49–0·54 vs 0·34 in the mixture in the first year, 0·28–0·33 vs 0·15 in the second year and 0·03–0·18 vs 0·01 in the third year). Total herbage production in the growing season in the spatially separated treatments decreased from 11384 kg DM ha−1 in the first year to 8150 kg DM ha−1 in the third year. Crude protein concentration of clover and grass components in the 18‐m adjacent monoculture treatment was greater than the mixture treatment for both clover (310 vs 280 g kg−1 DM) and grass (200 vs 180 g kg−1 DM). There was no clear benefit in liveweight gain beyond the first year in response to spatially separating grass and clover into monocultures within the same field.
Triggers in Allodynic and Non‐Allodynic Migraineurs. A Clinic Setting Study
Authors: Baldacci Filippo , Vedovello Marcella , Ulivi Martina , Vergallo Andrea , Poletti Michele , Borelli Paolo , Cipriani Gabriele , Nuti Angelo , Bonuccelli Ubaldo
Published: December 2012

Background

Allodynia is considered a phenomenon of central sensitization that may lead to migraine transformation, lowering the attack threshold. Migraine triggers are factors that may induce headache attacks in susceptible individuals. We hypothesize that because allodynia decreases the migraine‐attack threshold, allodynic migraineurs are more susceptible to triggers than the non‐allodynic ones.

Objective

To determine if the number of headache triggers differs between migraineurs with no/mild allodynia and those with moderate/severe allodynia.

Materials and Methods

We recruited 120 consecutive migraineurs. Other primary headache comorbidity and migraine prophylaxis were exclusion criteria. Each patient was interviewed according a structured questionnaire including general features about migraine, depression, and anxiety symptoms. Patients reported any migraine trigger both spontaneously and by selecting from a specific list. Allodynia during the migraine attack was measured using the Allodynia Symptoms Check‐List 12 (ASC‐12): a cut‐off of ASC‐12 score of >2 defined allodynic patients; 3‐5 score indicated mild allodynia; a 6‐8 score moderate allodynia; and score of >8 severe allodynia.

Results

The total number of identified triggers was significantly and positively related to allodynia measured with ASC‐12 (ρs 0.33; P < .001). In a logistic regression model, allodynia independently influenced the risk to have a higher number of triggers. Moderate/severe allodynic patients had an odds ratio of 2.8 to report a number of triggers >7 in respect to non‐/mild allodynic ones.

Conclusions

Migraineurs with moderate/severe allodynia had more triggers than those with no/mild allodynia. It is unknown if those with moderate/severe allodynia are more susceptible to triggers, or repetitive stimulation of the trigeminal system by triggers resulted in moderate/severe allodynia.
T helper type 17 cells contribute to anti‐tumour immunity and promote the recruitment of T helper type 1 cells to the tumour
Authors: Nuñez Sarah , Saez Juan Jose , Fernandez Dominique , Flores‐Santibañez Felipe , Alvarez Karla , Tejon Gabriela , Ruiz Paulina , Maldonado Paula , Hidalgo Yessia , Manriquez Valeria , Bono Maria Rosa , Rosemblatt Mario , Sauma Daniela
Published: December 2012

T helper type 17 (Th17) lymphocytes are found in high frequency in tumour‐burdened animals and cancer patients. These lymphocytes, characterized by the production of interleukin‐17 and other pro‐inflammatory cytokines, have a well‐defined role in the development of inflammatory and autoimmune pathologies; however, their function in tumour immunity is less clear. We explored possible opposing anti‐tumour and tumour‐promoting functions of Th17 cells by evaluating tumour growth and the ability to promote tumour infiltration of myeloid‐derived suppressor cells (MDSC), regulatory T cells and CD4+ interferon‐γ+ cells in a retinoic acid‐like orphan receptor γt (RORγt) ‐deficient mouse model. A reduced percentage of Th17 cells in the tumour microenvironment in RORγt‐deficient mice led to enhanced tumour growth, that could be reverted by adoptive transfer of Th17 cells. Differences in tumour growth were not associated with changes in the accumulation or suppressive function of MDSC and regulatory T cells but were related to a decrease in the proportion of CD4+ T cells in the tumour. Our results suggest that Th17 cells do not affect the recruitment of immunosuppressive populations but favour the recruitment of effector Th1 cells to the tumour, thereby promoting anti‐tumour responses.
Marriage-Related Migration to the UK
Authors: Charsley Katharine , Storer-Church Brooke , Benson Michaela , Van Hear Nicholas
Published: December 2012

Spouses form the largest single category of migrant settlement in the UK, but research and policy making on marriage-related migration to Britain provides incomplete coverage of the phenomenon, having been dominated by a focus on the South Asian populations that are among the largest groups of such migrants. By bringing together immigration statistics with information from academic and third-sector sources, this article attempts to provide a more balanced and nuanced portrayal of patterns and practices of marriage-related migration to the UK. In doing so, it reveals important nationality and gender differences in migration flows and considers how varying marriage practices, social and political contexts, and policies of both receiving and sending countries may work to influence marriage-related migration streams. It also exposes the limitations and lacunae in existing research on this diverse form of migration, highlighting the danger that immigration policy made on the basis of partial evidence will produce unexpected consequences.
University Education as a Compensation Strategy among Second-Generation Immigrants
Authors: Urban Susanne
Published: December 2012

The aim of this study is to determine whether immigrants and their children use a compensation strategy that involves achieving higher than expected education, given their parents’ level of education and income. The study uses data for all individuals in Sweden who finished elementary school from 1990 to 1992. Parents’ level of education and income is in general positively associated with higher odds of having university education. However, some immigrant groups show the reverse pattern of the impact of parents’ income. The results support a compensation strategy developed in groups and families with low level of integration in the labor market.
Psychometric Equivalence of Ratings for Repeat Examinees on a Performance Assessment for Physician Licensure
Authors: Raymond Mark R. , Swygert Kimberly A. , Kahraman Nilufer
Published: December 2012

Although a few studies report sizable score gains for examinees who repeat performance‐based assessments, research has not yet addressed the reliability and validity of inferences based on ratings of repeat examinees on such tests. This study analyzed scores for 8,457 single‐take examinees and 4,030 repeat examinees who completed a 6‐hour clinical skills assessment required for physician licensure. Each examinee was rated in four skill domains: data gathering, communication‐interpersonal skills, spoken English proficiency, and documentation proficiency. Conditional standard errors of measurement computed for single‐take and multiple‐take examinees indicated that ratings were of comparable precision for the two groups within each of the four skill domains; however, conditional errors were larger for low‐scoring examinees regardless of retest status. In addition, on their first attempt multiple‐take examinees exhibited less score consistency across the skill domains but on their second attempt their scores became more consistent. Further, the median correlation between scores on the four clinical skill domains and three external measures was .15 for multiple‐take examinees on their first attempt but increased to .27 for their second attempt, a value, which was comparable to the median correlation of .26 for single‐take examinees. The findings support the validity of inferences based on scores from the second attempt.
Meta‐Analytic Methodology and Inferences About the Efficacy of Formative Assessment
Authors: Briggs Derek C. , Ruiz‐Primo Maria Araceli , Furtak Erin , Shepard Lorrie , Yin Yue
Published: December 2012

In a recent article published in EM:IP, Kingston and Nash report on the results of a meta‐analysis on the efficacy of formative assessment. They conclude that the average effect of formative assessment on student achievement is about .20 SD units. This would seem to dispel the myth that effects between .40 and .70 can be attributed to formative assessment. They also find that there is considerable variability in effect sizes across studies, and that only the content area in which the treatment is situated explains a significant proportion of study variability. However, there are issues in the meta‐analytic methodology employed by the authors that make their findings somewhat equivocal. This commentary focuses on four methodological concerns about the Kingston and Nash meta‐analysis: (1) the approach taken to select studies for inclusion, (2) the application of study inclusion criteria, (3) the extent to which the effect sizes being combined are biased, and (4) the relationship between effect size magnitude and characteristics of outcome measures. After examining these issues in the context of the Kingston and Nash review, it appears that considerable uncertainty remains about the effect that formative assessment practices have on student achievement.
Assessment of protein expression and gene status of human epidermal growth factor receptor (HER) family molecules in ameloblastomas
Authors: Oikawa Mariko , Miki Yasuhiro , Shimizu Yoshinaka , Kumamoto Hiroyuki
Published: December 2012

Background

To evaluate roles of human epidermal growth factor receptor (HER) family molecules in ameloblastomas, protein expression and gene status were analyzed in odontogenic tissues.

Methods

Sixty five ameloblastomas, 10 dental follicles, and 11 dentigerous cysts were immunohistochemically examined with antibodies against epidermal growth factor receptor (EGFR) and HER2, HER3, and HER4. Amplification of EGFR and HER2 was evaluated by chromogenic in situ hybridization (CISH). In 18 ameloblastomas, EGFR exons 19 and 21 were analyzed by direct DNA sequencing.

Results

Immunohistochemical reactivity for EGFR and HER2, HER3, and HER4 was detected in odontogenic epithelium. Expression of EGFR and HER4 was remarkable in these odontogenic tissues, as compared with that of HER2 and HER3. The level of HER2 immunoreactivity was significantly lower in ameloblastomas than in dental follicles and dentigerous cysts. Follicular ameloblastomas showed significantly higher expression of HER2 and HER4 than plexiform ameloblastomas. Reactivity for EGFR and HER3 was slightly stronger in recurrent ameloblastomas than in primary ameloblastomas. CISH did not reveal obvious amplification of EGFR or HER2 in ameloblastomas; however, EGFR and HER2 gene signals were significantly higher in follicular ameloblastomas than in plexiform ameloblastomas. Direct DNA sequencing of EGFR did not show any gene alteration in ameloblastomas.

Conclusion

Expression of HER family molecules, especially EGFR and HER4, in odontogenic tissues suggests that growth signals mediated by these receptor molecules contribute to cell proliferation, survival, and differentiation in both normal and neoplastic odontogenic epithelial tissues. Some of these molecules might be useful for predicting outcomes in patients with ameloblastomas.
The effect of proximity in perceptual dialectology
Authors: Montgomery Chris
Published: December 2012

This article examines the effect of proximity on perceptual dialectological data gathered in Northern Great Britain. It underlines the key effect that proximity has on respondent mental maps of language variation, and demonstrates this by discussing area recognition levels and map‐based data. The article demonstrates that the effects of physical proximity can be modified by various factors. These factors include the ‘barrier effect’ of national borders such as the Scottish‐English border, along with other, more subjective, psychological boundaries such as the North‐South divide. In addition to demonstrating that these barrier effects increase the effect of proximity, this article will also show that proximity effects can be reduced by factors such as ‘cultural prominence’ (in which culturally important locations feature more prominently in mental maps of dialect areas).
Intracaval and intracardiac extension of invasive thymoma complicated by superior and inferior vena cava syndrome
Authors: Kurata Atsushi , Saji Hisashi , Ikeda Norihiko , Kuroda Masahiko
Published: December 2012

We present a case of an aged male with invasive thymoma that extended into the right atrium and led to superior and inferior vena cava syndrome. The patient initially presented with edema of the face and bilateral lower extremities. Echocardiography revealed a mass within the right atrium. Imaging studies demonstrated an anterior mediastinal tumor that continuously occupied the bilateral brachiocephalic veins, superior vena cava, and right atrium. Pathological diagnosis of the tumor biopsy was highly suspicious of thymoma. Due to the high risk of wide spread of the tumor, treatments including resection of the tumor were impossible. Several days later he died, and an autopsy was performed. The tumor was type B2 thymoma invading bilateral brachiocephalic veins, superior vena cava and right atrium. Multiple tumor emboli within the pulmonary arteries were identified. Direct cause of death was deemed to be tumor strangulation at the tricuspid orifice. In addition to the superior vena cava syndrome, inferior vena cava syndrome including ectasia of the intrahepatic vessels was confirmed along with pericarditis. To our knowledge, this is the first English report of an autopsy case of intracardiac thymoma extension, and a detailed literature review of similar cases is also presented.
International guidelines for the in vivo assessment of skin properties in non‐clinical settings: part 1. pH
Authors: Stefaniak Aleksandr B. , Plessis Johan du , John Swen M. , Eloff Fritz , Agner Tove , Chou Tzu‐Chieh , Nixon Rosemary , Steiner Markus F. C. , Kudla Irena , Linn Holness D.
Published: December 2012

Background

Skin surface pH is known to influence the dissolution and partitioning of chemicals and may influence exposures that lead to skin diseases. Non‐clinical environments (e.g. workplaces) are highly variable, thereby presenting unique measurement challenges that are not typically encountered in clinical settings. Hence, guidelines are needed for consistent measurement of skin surface pH in environments that are difficult to control.

Methods

An expert workshop was convened at the 5th International Conference on Occupational and Environmental Exposure of Skin to Chemicals to review available data on factors that could influence the determination of skin surface pH in non‐clinical settings with emphasis on the workplace as a worst case scenario.

Results

The key elements of the guidelines are: (i) minimize, to the extent feasible, the influences of relevant endogenous (anatomical position, skin health, time of day), exogenous (hand washing, barrier creams, soaps and detergents, occlusion), environmental (seasonality), and measurement (atmospheric conditions) factors; (ii) report pH measurements results as a difference or percent change (not absolute values) using a measure of central tendency and variability; and (iii) report notable deviations from these guidelines and other relevant factors that may influence measurements.

Conclusion

Guidelines on the measurement and reporting of skin surface pH in non‐clinical settings should promote consistency in data reporting, facilitate inter‐comparison of study results, and aid in understanding and preventing occupational skin diseases.
Modeling and Simulations of Mosquito Dispersal. The Case of Aedes albopictus
Authors: Dufourd Claire , Dumont Yves
Published: December 2012

To prevent epidemics of mosquito-transmitted diseases like Chikungunya in RВґeunion Island, we develop tools to control its principal vector, Aedes albopictus. Biological control tools, like the Sterile Insect Technique (SIT), are of great interest as an alternative to chemical control tools which are very detrimental to environment. The success of SIT is based on a good knowlege of the biology of the insect, but also on an accurate modeling of the insects distribution. We model the mosquito dispersal with a system of coupled parabolic PDEs. Considering vector control scenarii, we show that the environment can have a strong influence on mosquito distribution and in the efficiency of vector control tools.
Farewell Speech: Stefan Dodunekov (1945-2012)
Authors: Sendov Blagovest
Published: December 2012

Dear mournful family and all present,We are here to bow and to send to his eternal rest the President of the Bulgarian Academy of SciencesвЂ”Academician Stefan Manev Dodunekov. We have come to share together the enormous loss every one of us has suffered.The family lost their loving and caring father and husband, the mathematical community lost one of В its brightest and most active members, the Bulgarian В Academy of Sciences lost one of В its hopes for a better and more successful development, Bulgaria lost one quiet, but uncompromising patriot ...
In Memoriam: Stefan Dodunekov (1945-2012)
Authors: BIOMATH 2012 Organising Committee of
Published: December 2012

The President of the Bulgarian Academy of Sciences Stefan Dodunekov passed away on August 5, 2012, after a short illness at the age of 66. Stefan Dodunekov was a distinguished expert the field of coding theory. . . .
In Memoriam: Antony Popov (1962-2012)
Authors: BIOMATH 2012 Organising Committee of
Published: December 2012

We are deeply saddened by the sudden death at the age of 49 of our colleague Associate Professor Dr. Antony Popov, member of the Department вЂќInformation TechnologiesвЂќ, Faculty of Mathematics and Informatics, Sofia University. Tony was a very good mathematician, specializing in the area of Pattern Recognition. . . .В В
Dynamics of an SIS Model on Homogeneous Networks with Delayed Reduction of Contact Numbers
Authors: Liu Maoxing , Röst Gergely
Published: December 2012

During infectious disease outbreaks, people may modify their contact patterns after realizing the risk of infection. In this paper, we assume that individuals make the decision of reducing a fraction of their links when the density of infected individuals exceeds some threshold, but the decision is made with some delay. Under such assumption, we study the dynamics of a delayed SIS epidemic model on homogenous networks. By theoretical analysis and simulations, we conclude that the density of infected individuals periodically oscillate for some range of the basic reproduction number. Our results indicate that information delays can have important effects on the dynamics of infectious diseases.
Predator-Prey Model with Prey Harvesting, Holling Response Function of Type III and SIS Disease
Authors: Tewa Jean Jules , Demasse Ramses Djidjou , Bowong Samuel
Published: December 2012

The populations of prey and predator interact with prey harvesting. When there is no predator, the logistic equation models the behavior of the preys. For interactions between preys and predators, we use the generalized Holling response function of type III. This function which models the consumption of preys by predators is such that the predation rate of predators increases when the preys are few and decreases when they reach their satiety. Our main goal is to analyze the influence of a SIS infectious disease in the community. The epidemiological SIS model with simple mass incidence is chosen, where only susceptibles and infectious are counted. We assume firstly that the disease spreads only among the prey population and secondly that it spreads only among the predator population. There are many bifurcations as: Hopf bifurcation, transcritical bifurcation and saddle-node bifurcation. The results indicate that either the disease dies out or persists and then, at least one population can disappear because of infection. For some particular choices of the parameters however, there exists endemic equilibria in which both populations survive. Numerical simulations on MATLAB and SCILAB are used to illustrate our results.
From the Guest-Editor
Authors: Markov Svetoslav
Published: December 2012

The BIOMATH 2012 International Conference on Mathematical Methods and Models in Biosciences was held at the Bulgarian Academy of Sciences in Sofia, in June 17-22, 2012, http://www.biomath.bg/2012/.В  We were happy to meet more than 70 participantsВ  from twenty differentВ  countries.В В  More than 40 contributions were submitted for publication in the present BIOMATH proceedings.В  All submitted papers have been peer-reviewed by at least two independent anonymous reviewers. Twelve selected papers are published in the first issue of this journal. This second issue contains anotherВ ten selected contributions which will be published continuously in the electronic version of the journal.В В  . . .В В В В В В В
Modelling of a Fed-Batch Culture Applying Simulated Annealing
Authors: Roeva Olympia , Trenkova Tanya
Published: December 2012

In this paper the metaheuristic Simulated Annealing (SA) is applied for parameter identification of non-linear model of cultivation process. SA algorithm is a stochastic relaxation technique, using the Metropolis algorithm based on the Boltzmann distribution in statistical mechanics, for solving nonconvex optimization problems. A real E. coli MC4110 fed-batch cultivation process is considered. The mathematical model is presented by a system of five ordinary differential equations, describing the regarded cultivation process variables - biomass, substrate, acetate, dissolved oxygen and bioreactor volume increasing. The obtained criteria values show that the developed model is adequate and has a high degree of accuracy. The presented results are a confirmation of successful application of the SA algorithm and of the choice of SA algorithm parameters.
Nonlinear Filters and Characterization of the Discrete Pulse Transform of Images
Authors: Fabris-Rotelli Inger
Published: December 2012

The Discrete Pulse Transform (DPT) for images and videos has been developed over the past few years and provides aВ theoretically sound setting for a nonlinear decomposition of an image or video. In [1] the theoretical basis of the DPT was presented. In this paper we now present a soundВ  characterization of this useful nonlinear hierarchical decomposition by referring to its ability as a separator, the consistency of the decomposition, as well as the smoothing ability of the decomposition.
Position-Induced Phase Change in a TASEP with a Double-Chain Section (a Model of Biological Transport)
Authors: Pesheva Nina Christova , Brankov Jordan Georgiev
Published: December 2012

The totally asymmetric simple exclusion processes (TASEP) has beenused since 1968 to model different biochemical processes,including kinetics of protein synthesis, molecular motors traffic,collective effects in genetic transcription. Here, we considerTASEP defined on an open network consisting of simple head andtail chains with a double-chain section in-between. Our results of Monte Carlo simulations show a novel property of the model when the simple chains are in the maximum-current phase: upon moving the double-chain defect from the central position forward or backward along the network, keeping fixed the length of both the defect and the whole network, a position-induced phase change in the parallel defect chains takes place. This phenomenon is explained in terms of finite-size dependence of the effective injection and removal rates at the ends of the double-chain defect. Some implications of the results for molecular motors cellular transport along such networks are suggested. However, at present these are just speculations which need further examinations.
Mathematical Problems in the Theory of Bone Poroelasticity
Authors: Svanadze Merab , Scalia Antonio
Published: December 2012

This paper concerns with the quasi-static theory of bone poroelasticity for materials with double porosity. The system of equations of this theory based on the equilibrium equations, conservation of fluid mass, the effective stress concept and DarcyвЂ™s law for material with double porosity. The internal and external basic boundary value problems (BVPs) are formulated and uniqueness of regular (classical) solutions are proved. The single-layer and double-layer potentials are constructed and their basic properties are established. Finally, the existence theorems for classical solutions of the BVPs are proved by means of the potential method (boundary integral method) and the theory of singular integral equations.
A Linear Complementarity Numerical Approach to the Non-Convex Problem of Structures Environmentally Damaged and Strengthened by Cable-Bracings
Authors: Liolios Konstantinos , Radev Stefan , Liolios Asterios , Georgiev Ivan , Georgiev Krassimir
Published: December 2012

A computational treatment is presented for the mathematically rigorous analysis of civil engineering structures, which have been environmentally damaged and subsequently strengthened by cable-elements. The problem is treated as an inequality one, where the governing conditions are equalities as well as inequalities. The cable behavior is considered as nonconvex and nonmonotone one and is described by generalized subdifferential relations including loosening, elastoplastic - fracturing and other effects. Using piece-wise linearization for the cable behavior, a linear complementarity problem, with a reduced number of unknowns, is solved by optimization algorithms. Finally, an example from Civil and Environmental Engineering praxis is presented.
Supersonic Two-Phase Impinging Jet Heat Transfer
Authors: Parker Richard R. , Klausner James F. , Mei Renwei
Published: December 2012

The experimental heat transfer rates from a supersonic two-phase impinging air jet with disperse droplets are presented. The experimental configuration consists of an expanding disperse mixture of air and water through a converging–diverging nozzle, designed for Mach 3.26 with a liquid to air mass flow ratio ranging from 1.28% to 3.83%, impinging upon a thin film heater constructed of nichrome. The spatially varying heat transfer coefficient is measured, and peak values are on the order of 200,000 W/m2K. Two distinct regions of heat transfer are identified, one dominated by the jet impingement flow and another dominated by thin film heat transfer. The heat transfer coefficient of an impinging jet with dry air and no droplets is measured during the investigation as well. The heat transfer results are compared, and it is demonstrated that the addition of disperse water droplets to the jet significantly increases the heat removal capability of the jet as well as smoothing the spatial temperature distribution of the heater surface. As much as an order of magnitude increase in heat transfer coefficient is observed near the centerline of the jet and a factor of 3–5 increase is seen at a distance of approximately 4 nozzle diameters from the jet. The fundamental heat transfer coefficient measurements should benefit applications involving supersonic two-phase jets for high heat flux thermal management.
Benchmark Solutions for Slip Flow and H1 Heat Transfer in Rectangular and Equilateral Triangular Ducts
Authors: Wang C. Y.
Published: December 2012

Accurate analytic solutions for the fully developed slip flow and H1 heat transfer in rectangular and equilateral triangular ducts are presented. Both velocity slip and temperature jump have significant influences on the Poiseuille and Nusselt numbers. These exact solutions serve as benchmark cases for other methods, whether analytic, approximate, or numerical.
Natural Convection From Horizontal Cylinders at Near-Critical Pressures—Part I: Experimental Study
Authors: Rousselet Yohann , Warrier Gopinath R. , Dhir Vijay K.
Published: December 2012

An experimental study of free convection heat transfer from horizontal wires to carbon dioxide at near-critical pressures has been performed. In the experiments, platinum wires ranging in size from 25.4 μm to 100 μm and a nichrome 60/20 wire of 101.6 μm diameter were used. The pressure (P) and bulk temperature (Tb) of the fluid were varied in the range: 6.34 MPa ≤ P ≤ 9.60 MPa and 10 °C ≤ Tb ≤ 33.3 °C, respectively. The wall temperature (Tw) was systematically increased from Tb + 0.1 °C to 250 °C. Visual observations of the fluid flow were made using a high speed camera. The similarity between natural convection heat transfer at Tw < Tsat (for P < Pc) and Tw < Tpc (for P > Pc), as well as the similarity between film boiling at Tw > Tsat (for P < Pc) and natural convection heat transfer at Tw > Tpc (for P > Pc), was demonstrated. The dependence of the heat transfer coefficient on the wire diameter was found to be h ∝ D−0.5, for both P < Pc and P > Pc. The bulk fluid temperature is introduced as a new reference temperature for the calculation of fluid properties. Correlations have been developed to predict the natural convection heat transfer coefficient at both subcritical and supercritical pressures. The developed correlations predict almost all the experimental data from the current study and those reported in the literature to within ±15%.
Quantitative Contributions of Target Alteration and Decreased Drug Accumulation to Pseudomonas aeruginosa Fluoroquinolone Resistance
Authors: Bruchmann Sebastian , Dötsch Andreas , Nouri Bianka , Chaberny Iris F. , Häussler Susanne
Published: December 2012

Quinolone antibiotics constitute a clinically successful and widely used class of broad-spectrum antibiotics; however, the emergence and spread of resistance increasingly limits the use of fluoroquinolones in the treatment and management of microbial disease. In this study, we evaluated the quantitative contributions of quinolone target alteration and efflux pump expression to fluoroquinolone resistance in
Pseudomonas aeruginosa
. We generated isogenic mutations in hot spots of the quinolone resistance-determining regions (QRDRs) of
gyrA
,
gyrB
, and
parC
and inactivated the efflux regulator genes so as to overexpress the corresponding multidrug resistance (MDR) efflux pumps. We then introduced the respective mutations into the reference strain PA14 singly and in various combinations. Whereas the combined inactivation of two efflux regulator-encoding genes did not lead to resistance levels higher than those obtained by inactivation of only one efflux regulator-encoding gene, the combination of mutations leading to increased efflux and target alteration clearly exhibited an additive effect. This combination of target alteration and overexpression of efflux pumps was commonly observed in clinical
P. aeruginosa
isolates; however, these two mechanisms were frequently found not to be sufficient to explain the level of fluoroquinolone resistance. Our results suggest that there are additional mechanisms, independent of the expression of the MexAB-OprM, MexCD-OprJ, MexEF-OprN, and/or MexXY-OprM efflux pump, that increase ciprofloxacin resistance in isolates with mutations in the QRDRs.
In Vivo
Activities of Ceftolozane, a New Cephalosporin, with and without Tazobactam against Pseudomonas aeruginosa and Enterobacteriaceae, Including Strains with Extended-Spectrum β-Lactamases, in the Thighs of Neutropenic Mice
Authors: Craig W. A. , Andes D. R.
Published: December 2012

Ceftolozane is a new cephalosporin with potent activity against
Pseudomonas aeruginosa
and
Enterobacteriaceae
. A neutropenic murine thigh infection model was used to determine which pharmacokinetic/pharmacodynamic index and magnitude drives the efficacy of ceftolozane with Gram-negative bacilli, to compare the rates of
in vivo
killing of
P. aeruginosa
by ceftolozane and ceftazidime, and to determine the impact of different ratios of ceftolozane plus tazobactam on
Enterobacteriaceae
containing extended-spectrum β-lactamases (ESBLs). Neutropenic mice had 10
6.2-7.1
CFU/thigh when treated with ceftolozane for 24 h with (i) various doses (3.12 to 1,600 mg/kg) and dosage intervals (3, 6, 12, and 24 h) against two
Enterobacteriaceae
strains, (ii) 0.39 to 800 mg/kg every 6 h for four
Enterobacteriaceae
and four
P. aeruginosa
strains, and (iii) 400 or 800 mg/kg with 2:1. 4:1, and 8:1 ratios of tazobactam against five
Enterobacteriaceae
strains with ESBLs. The pharmacokinetics of ceftolozane at 25, 100, and 400 mg/kg were linear with peak/dose values of 1.0 to 1.4 and half-lives of 12 to 14 min. T>MIC was the primary index driving efficacy. For stasis (1 log kill), T>MIC was 26.3% ± 2.1% (31.6% ± 1.6%) for wild-type
Enterobacteriaceae
, 31.1% ± 4.9% (34.8% ± 4.4%) for
Enterobacteriaceae
with ESBLs, and 24.0% ± 3.3% (31.5% ± 3.9%) for
P. aeruginosa
. At 200 mg/kg every 3 h, the rate of
in vivo
killing of
P. aeruginosa
was faster with ceftolozane than with ceftazidime (−0.34 to −0.41 log
10
CFU/thigh/h versus −0.21 to −0.24 log
10
CFU/thigh/h). The 2:1 ratio of ceftolozane with tazobactam was the most potent combination studied. The T>MIC required for ceftolozane is less than with other cephalosporins and may be due to more rapid killing.
Cationic Antimicrobial Peptide LL-37 Is Effective against both Extra- and Intracellular Staphylococcus aureus
Authors: Noore Jabeen , Noore Adly , Li Bingyun
Published: December 2012

The increasing resistance of bacteria to conventional antibiotics and the challenges posed by intracellular bacteria, which may be responsible for chronic and recurrent infections, have driven the need for advanced antimicrobial drugs for effective elimination of both extra- and intracellular pathogens. The purpose of this study was to determine the killing efficacy of cationic antimicrobial peptide LL-37 compared to conventional antibiotics against extra- and intracellular
Staphylococcus aureus
. Bacterial killing assays and an infection model of osteoblasts and
S. aureus
were studied to determine the bacterial killing efficacy of LL-37 and conventional antibiotics against extra- and intracellular
S. aureus
. We found that LL-37 was effective in killing extracellular
S. aureus
at nanomolar concentrations, while lactoferricin B was effective at micromolar concentrations and doxycycline and cefazolin at millimolar concentrations. LL-37 was surprisingly more effective in killing the clinical strain than in killing an ATCC strain of
S. aureus
. Moreover, LL-37 was superior to conventional antibiotics in eliminating intracellular
S. aureus
. The kinetic studies further revealed that LL-37 was fast in eliminating both extra- and intracellular
S. aureus
. Therefore, LL-37 was shown to be very potent and prompt in eliminating both extra- and intracellular
S. aureus
and was more effective in killing extra- and intracellular
S. aureus
than commonly used conventional antibiotics. LL-37 could potentially be used to treat chronic and recurrent infections due to its effectiveness in eliminating not only extracellular but also intracellular pathogens.
Pharmacokinetics and Pharmacodynamics of ASP2151, a Helicase-Primase Inhibitor, in a Murine Model of Herpes Simplex Virus Infection
Authors: Katsumata Kiyomitsu , Chono Koji , Kato Kota , Ohtsu Yoshiaki , Takakura Shoji , Kontani Toru , Suzuki Hiroshi
Published: December 2012

ASP2151 (amenamevir) is a helicase-primase inhibitor against herpes simplex virus 1 (HSV-1), HSV-2, and varicella zoster virus. Here, to determine and analyze the correlation between the pharmacodynamic (PD) and pharmacokinetic (PK) parameters of ASP2151, we examined the PD profile of ASP2151 using
in vitro
plaque reduction assay and a murine model of HSV-1 infection. ASP2151 inhibited the
in vitro
replication of HSV-1 with a mean 50% effective concentration (EC
50
) of 14 ng/ml. In the cutaneously HSV-1-infected mouse model, ASP2151 dose dependently suppressed intradermal HSV-1 growth, with the effect reaching a plateau at a dose of 30 mg/kg of body weight/day. The dose fractionation study showed that intradermal HSV-1 titers were below the detection limit in mice treated with ASP2151 at 100 mg/kg/day divided into two daily doses and at 30 or 100 mg/kg/day divided into three daily doses. The intradermal HSV-1 titer correlated with the maximum concentration of drug in serum (
C
max
), the area under the concentration-time curve over 24 h (AUC
24h
), and the time during which the concentration of ASP2151 in plasma was above 100 ng/ml (
T
>100
). The continuous infusion of ASP2151 effectively decreased intradermal HSV-1 titers below the limit of detection in mice in which the ASP2151 concentration in plasma reached 79 to 145 ng/ml. Our findings suggest that the antiviral efficacy of ASP2151 is most closely associated with the PK parameter
T
>100
in HSV-1-infected mice. Based on these results, we propose that a plasma ASP2151 concentration exceeding 100 ng/ml for 21 to 24 h per day provides the maximum efficacy in HSV-1-infected mice.
Coordinated Roles of Pregnane X Receptor and Constitutive Androstane Receptor in Autoinduction of Voriconazole Metabolism in Mice
Authors: Ohbuchi Masato , Yoshinari Kouichi , Kaneko Hayato , Matsumoto Satoru , Inoue Akiko , Kawamura Akio , Usui Takashi , Yamazoe Yasushi
Published: December 2012

The antifungal efficacy of voriconazole (VRC) differs among host species, with potent efficacy in humans but less in rodents. We investigated the possible involvement of pregnane X receptor (PXR) and constitutive androstane receptor (CAR) in the species-specific efficacy of VRC through pharmacokinetic analyses using genetically modified mice and primary human hepatocytes. VRC (30 mg/kg) was orally administered to wild-type,
Pxr
-null,
Car
-null, and
Pxr
- and
Car
-null (
Pxr
/
Car
-null) mice for 7 days. Hepatic VRC metabolism was significantly increased by VRC administration, and the elimination rates of plasma VRC were much higher on day 7 than on day 1 in wild-type mice. This autoinduction was also observed in
Pxr
-null and
Car
-null mice but not in
Pxr
/
Car
-null mice, suggesting coordinated roles of PXR and CAR in the autoinduction of VRC metabolism in mice. Hepatic
Cyp3a11
mRNA levels were increased by VRC administration, hepatic metabolic activities for VRC were correlated with CYP3A activities, and the induced VRC metabolism was inhibited by ketoconazole (a CYP3A inhibitor). In primary human hepatocytes, VRC barely increased mRNA levels of
CYP3A4
and
CYP2B6
(human PXR/CAR target genes) at its therapeutic concentrations. In conclusion, these results suggest that VRC is metabolized mainly by CYP3A11 in mouse livers and that PXR- and CAR-mediated CYP3A11 induction, namely, autoinduction of VRC metabolism, is a primary reason for the ineffectiveness of VRC in mice. A limited ability of VRC to activate human PXR/CAR at its clinical concentration might explain the VRC efficacy in humans. Therefore, the ability to activate PXR/CAR might determine the VRC efficacy in different mammalian species.
Mutational and Transcriptomic Changes Involved in the Development of Macrolide Resistance in Campylobacter jejuni
Authors: Hao Haihong , Yuan Zonghui , Shen Zhangqi , Han Jing , Sahin Orhan , Liu Peng , Zhang Qijing
Published: December 2012

Macrolide antibiotics are important for clinical treatment of infections caused by
Campylobacter jejuni
. Development of resistance to this class of antibiotics in
Campylobacter
is a complex process, and the dynamic molecular changes involved in this process remain poorly defined. Multiple lineages of macrolide-resistant mutants were selected by stepwise exposure of
C. jejuni
to escalating doses of erythromycin or tylosin. Mutations in target genes were determined by DNA sequencing, and the dynamic changes in the expression of antibiotic efflux transporters and the transcriptome of
C. jejuni
were examined by real-time reverse transcription-PCR, immunoblotting, and DNA microarray analysis. Multiple types of mutations in ribosomal proteins L4 and L22 occurred early during stepwise selection. On the contrary, the mutations in the 23S rRNA gene, mediating high resistance to macrolides, were observed only in the late-stage mutants. Upregulation of antibiotic efflux genes was observed in the intermediately resistant mutants, and the magnitude of upregulation declined with the occurrence of mutations in the 23S rRNA gene. DNA microarray analysis revealed the differential expression of 265 genes, most of which occurred in the intermediate mutant, including the upregulation of genes encoding ribosomal proteins and the downregulation of genes involved in energy metabolism and motility. These results indicate (i) that mutations in L4 and L22 along with temporal overexpression of antibiotic efflux genes precede and may facilitate the development of high-level macrolide resistance and (ii) that the development of macrolide resistance affects the pathways important for physiology and metabolism in
C. jejuni
, providing an explanation for the reduced fitness of macrolide-resistant
Campylobacter
.