bluuebunny/crossref_metadata_2025 huggingface dataset:
Distribution of taste buds in layer‐type chickens: Scanning electron microscopic observations
Authors: KUDO Ken‐ichi , NISHIMURA Shotaro , TABATA Shoji
Published: September 2008

The distribution of taste buds of layer‐type chickens, from day 1 (H1) to day 140 (H140) post‐hatching, were investigated histologically and with a scanning electron microscope. Two types of openings were observed on the oral epithelium: large openings that were greater than 10 μm in width, and had an ellipsoid or spindle shape; and small openings that were less than 7 μm in width, and had a circular or polygon shape. It was defined that the former represent the openings of the salivary glands, and the latter are those of the taste buds. The number of taste buds remained constant from H1 to H140. Therefore, no significant change was observed between these two time points. To investigate the distribution of the taste buds in the whole oral cavity, a distribution map was created.
Lectin binding patterns in the olfactory bulb of mallard ducks (Anas platyrhynchos)
Authors: HIRAO Atsushi , OOKAWARA Shigeo
Published: September 2008

We histologically examined lectin binding patterns in the olfactory bulb of mallard ducks (Anas platyrhynchos) using 21 biotinylated lectins. Positive staining for the N‐acetylglucosamine‐specific lectins (Bandeiraea simplicifolia II, Datura stramonium, Lycopersicon esculentum, Solanum tuberosum, Triticum vulgare), galactose or N‐acetylgalactosamine‐specific lectins (Artocarpus intergrifolia, Phaseolus vulgaris erythroagglutinin, Phaseolus vulgaris leucoagglutinin, Ricus communis) and the mannose‐specific lectins (Lens culinaris and Pisum sativum) was observed in the olfactory nerve and glomerular layers. Canavalia ensiformis staining showed a similar pattern to that obtained with the lectins and there was also faint staining in the mitral cells. Olfactory nerve axons terminate in the glomeruli, where they make excitatory synapses with the dendrites of mitral cells. This finding indicates that glycoconjugates that bind Canavalia ensiformis play an important role in formation of glomeruli. No positive staining for the other lectins was seen in the olfactory bulb. Based on these results, we conclude that cell surface sugar moieties of the olfactory bulb in mallard ducks express N‐acetylglucosamine and mannose residues rather than N‐acetylgalactosamine residues. The carbohydrate composition of mallard duck olfactory bulb differed from that of other vertebrates found in previous studies.
The interplay of genetic and environmental factors in craniofacial morphogenesis: holoprosencephaly and the role of cholesterol
Authors: Edison Robin , Muenke Maximilian
Published: September 2008

ABSTRACT Cyclopia, the paradigmatic “face [that] predicts the brain” in severe holoprosencephaly (HPE) (DeMyeret al., 1964), has been recognized since ancient times. Descriptive embryologists and pathologists have noted the continuum of defective separation of the forebrain and loss of central nervous system (CNS) mid‐line structures for more than a century. It has been recognized more recently that inhibitors of cholesterol biosynthesis, whether consumed in native plants by range sheep, or experimentally applied to early embryos, could pheno‐copy the natural malformation, as could a variety of other teratogens (maternal diabetes, alcohol). Yet it has been less than a decade that the genomic knowledge base and powerful analytic methods have brought the sciences of descriptive, molecular, and genetic embryology within range of each other. In this review, we discuss the clinical presentations and pathogenesis of HPE. We will outline various genetic and teratogenic mechanisms leading to HPE. Lastly, we will attempt to examine the pivotal role of cholesterol and the Sonic Hedgehog (Shh) pathway in this disorder and in normal embryonic forebrain development.
Opposite effects of the maternal immune system activated by interleukin‐1β vs. PSK and OK432 on 5‐azacytidine‐induced birth defects
Authors: Hatta Toshihisa , Matsumoto Akihiro , Moriyama Kenji , Otani Hiroki
Published: September 2008

ABSTRACT  Effects of stimulation of the maternal immune system on abnormal pregnancy induced with 5‐azacytidine (5ACDR) administration at embryonic day 7.5 (E7.5) were examined in mice treated with recombi‐nant interleukin 1β (IL‐1β) at E6.5 (5ACDR + IL‐1 at E6.5) or E9.5 (5ACDR+IL‐1 at E9.5), OK432 (5ACDR + OK432) at E7.5 or PSK (5ACDR+PSK) at E7.5. Embryos from these dams were examined at E13.5. The frequency of dead and malformed embryos and number of malformations on each embryo increased in the 5ACDR + IL‐1 at E6.5 groups compared with the 5ACDR‐alone group. Adverse pregnancy outcomes in the 5ACDR + OK432 and 5ACDR + PSK groups were less frequent than in the 5ACDR‐alone group. The frequency of exencephaly, facial cleft, eye anomalies (micro‐ or anophthalmos), and micrognathia significantly increased in the 5ACDR + IL‐1 groups, in contrast, that of exencephaly decreased in the 5ACDR + OK432 and 5ACDR + PSK groups compared with the 5ACDR‐alone group. The phagocytes on the exencephalic surface drastically increased in the 5ACDR + IL‐1 groups, and they often appeared to ingest the migrating neuroepithelial cells. Such findings, however, were rarely observed in the 5ACDR‐alone, 5ACDR + OK432 and 5ACDR + PSK groups. Thus, administration of IL‐1β to the abnormal pregnant dams increased the mortality and severity of the malformations in the embryos caused by 5ACDR, whereas PSK or OK432 decreased them. These results suggest that the different modes of activation of the maternal immune system may exert alternative or opposite effects on teratogenic pregnancy.
The effects of dietary vitamin B12 deficiency on sperm maturation in developing and growing male rats
Authors: Watanabe Toshiaki , Ohkawa Keiko , Kasai Shigenobu , Ebara Shuhei , Nakano Yoshihisa , Watanabe Yoshitaka
Published: September 2008

ABSTRACT  To evaluate the role of vitamin B12 on spermatogenesis, the effects of dietary vitamin B12 deficiency on sperm maturation in developing rat fetuses and young growing rats were examined. The vitamin B12‐defi‐cient diet was given to all the animals for three different periods: whole period (gestation to mature), gestation period (gestation to weaning), or immature period (3–12 weeks postnatal). Sperm examination revealed that the sperm count was markedly lower in male progeny (F1) that were vitamin B12‐deficient during the whole period. In addition, a significantly higher number of abnormal sperm, such as tailless and amorphous sperm, was observed. In male rats that were vitamin B12‐deficient during the immature period, the incidence of abnormal sperms was 14.4% and 4.8% for tailless and short tail, respectively. The motion rates, such as path velocity and straight line velocity, were decreased to 20–40% of the control value in rats that were vitamin B12‐deficient both during the whole and gestation periods. However, no effects of vitamin B12 deficiency on sperm motility were observed during the immature and mature periods. From these findings, we suggest that dietary vitamin B12 deficiency during pregnancy may induce irreversible damage in the germ cells of embryos and affect the maturation of spermatozoa.
Fukuyama‐type congenital muscular dystrophy (FCMD) and α‐dystroglycanopathy
Authors: Toda Tatsushi , Kobayashi Kazuhiro , Takeda Satoshi , Sasaki Junko , Kurahashi Hiroki , Kano Hiroki , Tachikawa Masaji , Wang Fan , Nagai Yoshitaka , Taniguchi Kiyomi , Taniguchi Mariko , Sunada Yoshihide , Terashima Toshio , Endo Tamao , Matsumura Kiichiro
Published: September 2008

ABSTRACT  Fukuyama‐type congenital muscular dystrophy (FCMD), Walker‐Warburg syndrome (WWS), and muscle‐eye‐brain (MEB) disease are clinically similar autosomal recessive disorders characterized by congenital muscular dystrophy, lissencephaly, and eye anomalies. Through positional cloning, we identified the gene for FCMD and MEB, which encodes the fukutin protein and the protein O‐linked mannose β1, 2‐N‐acetylgIucosaminy ltransferase (POMGnT1), respectively. Recent studies have revealed that posttranslational modification of α‐dystro‐glycan is associated with these congenital muscular dystrophies with brain malformations. In this review Fukuyama‐type congenital muscular dystrophy (FCMD), other CMDs with brain malformations, and their relation with α‐dystroglycan are discussed.
An improved technique for repeated gavage administration to rat neonates
Authors: Watanabe Chiaki , Kuwagata Makiko , Yoshimura Shinsuke , Azegami Jiro , Kojima Kouichi , Ono Hiroshi , Nagao Tetsuji
Published: September 2008

ABSTRACT  The technique for gavage administration to rat nurslings was improved to allow determination of the direct effects of chemical substances in the nurslings. Rat neonates were treated with distilled water from postnatal day 1 through 20 using this technique. The viability of neonates during the administration period was comparable to that of untreated neonates. No adverse effects of this technique on the development of neonates were found, and no histological alterations of the esophagus or pharynx. Therefore, we conclude that use of our improved gavage administration method will contribute to ensuring successful neonatal development and thus allowing accurate assessment of the toxicological effects of test compounds on rat nurslings.
Translation and cultural adaptation of the patient disease and treatment assessment form: A novel quality of life instrument for use in Taiwan
Authors: GAINFORD Mary Corona , YANG Chih‐Hsin , LIU Mei‐Ying , STOCKLER Martin
Published: September 2008

Aim:  Quality of Life (QoL) is an important end‐point in cancer clinical trials, but its collection in multinational trials requires properly translated and validated instruments. We describe the development, piloting and planned validation of a traditional Chinese version of the Patient Disease Treatment and Assessment Form (Pt DATA Form) for use in Taiwan.

Methods:  The Pt DATA Form is a simple, multi‐item QoL instrument based on 11‐point numeric rating scales for a range of relevant symptoms and functions and aspects of well‐being, designed for use in routine clinical practice and clinical trials. The instrument underwent forward translation in Sydney and backward translation in Taiwan. A reconciled version was pre‐tested on healthy volunteers and then on 20 cancer patients in a Taiwanese clinic.

Results:  One hundred percent of patients reported that the items were clear and did not cause upset. Eighty five percent had no difficulty in completing the form while 10% found it fairly difficult. There were no difficulties with the instructions.

Conclusion:  This questionnaire was acceptable for use in Taiwan in its current format and will allow the collection of innovative data on Chinese cancer patients' experiences.
Formation of a giant Hi bridge between M31 and M33 from their tidal interaction
Authors: Bekki Kenji
Published: September 2008

Recent observations have discovered a giant H i bridge that appears to connect between the outer halo regions of M31 and M33. We propose that this H i bridge can be formed as a result of the past interaction between M31 and M33 based on test-particle simulations with different orbits of M31 and M33 for the last ∼9 Gyr. We show that strong tidal interaction between M31 and M33 about 4–8 Gyr ago can strip H i gas from M33 to form H i streams around M31 which can be observed as a H i bridge if they are projected on to the sky. We show that the number fraction of models reproducing well the observed H i distribution of the bridge is only ∼0.01 per cent (i.e. ∼10 among ∼105 models), and thus suggest that the observed structure and kinematics of the H i bridge can give some constraints on the past orbits of M31 and M33. We suggest that the observed outer H i warp in M33 could be fossil evidence for the past M31–M33 interaction. We also suggest that some of high-velocity clouds (HVCs) recently found in M31 could be H i gas originating from M33. We briefly discuss other possible scenarios for the formation of the H i bridge.
Higher‐Order Ontological Arguments
Authors: Oppy Graham
Published: September 2008

This paper discusses recent work on higher‐order ontological arguments, including work on arguments due to Gödel, Maydole and Pruss. After setting out a range of these arguments, the paper seeks to highlight the principal difficulties that these kinds of arguments confront. One important aim of the paper is to cast light on Gödel's ontological argument by way of an examination of a range of related higher‐order arguments.
God in Recent French Phenomenology
Authors: Simmons J. Aaron
Published: September 2008

In this essay, I provide an introduction to the so‐called ‘theological turn’ in recent French, ‘new’ phenomenology. I begin by articulating the stakes of excluding God from phenomenology (as advocated by Edmund Husserl and Martin Heidegger) and then move on to a brief consideration of why Dominique Janicaud contends that, by inquiring into the ‘inapparent’, new phenomenology is no longer phenomenological. I then consider the general trajectories of this recent movement and argue that there are five main themes that unite the work of such varied thinkers as Levinas, Derrida, Marion, Henry, Chrétien, Lacoste, and Ricœur. I conclude by outlining points of overlap between new phenomenology and contemporary analytic philosophy of religion and suggest that the two stand as important resources for each other.
Business Ethics: An Overview
Authors: Moriarty Jeffrey
Published: September 2008

This essay provides an overview of business ethics. I describe important issues, identify some of the normative considerations animating them, and offer a roadmap of references for those wishing to learn more. I focus on issues in normative business ethics, but discuss briefly the growing body of work in descriptive business ethics. I conclude with a comment on the changing nature of the field.
Dharmak?rti's Dualism: Critical Reflections on a Buddhist Proof of Rebirth
Authors: Arnold Dan
Published: September 2008

Dharmak?rti, elaborating one of the Buddhist tradition's most complete defenses of rebirth, advanced some of this tradition's most explicitly formulated arguments for mind‐body dualism. At the same time, Dharmak?rti himself may turn out to be vulnerable to some of the same kinds of arguments pressed against physicalists. It is revealing, then, that in arguing against physicalism himself, Dharmak?rti does not have available to him what some would judge to be more promising arguments for dualism (arguments, in particular, following Kant's 2nd Critique) – and indeed, that these arguments actually cut against Dharmak?rti's own position. After elaborating and characterizing Dharmak?rti's case for rebirth, then, this article briefly considers an argument that Dharmak?rti cannot himself enlist for this purpose.
Influence of sympathetic and AT1‐receptor blockade on angiotensin II and adrenergic agonist‐induced renal vasoconstrictions in spontaneously hypertensive rats
Authors: Abdulla M. H. , Sattar M. A. , Khan Md A. H. , Abdullah N. A. , Johns E. J.
Published: September 2008

Aim: This study investigated the influence of angiotensin II (Ang II) receptor and adrenergic blockade on the renal vasoconstrictions caused by Ang II and adrenergic agonists in spontaneously hypertensive rats (SHR).

Methods: Forty‐eight SHR were subjected to 7 days of losartan (10 mg kg−1 day−1p.o.), carvedilol (5 mg kg−1 day−1p.o.) or losartan + carvedilol (10 mg kg−1 day−1 + 5 mg kg−1 day−1p.o.). On day 8, the rats were anaesthetized and renal vasoconstrictor experiments performed. One group of rats underwent acute unilateral renal denervation.

Results: There were significant (P < 0.05) reductions in the renal vasoconstrictor responses to noradrenaline, phenylephrine, methoxamine and Ang II after losartan and carvedilol treatments compared with that in untreated rats (allP < 0.05). However, in renally denervated SHR treated with carvedilol, the vasoconstrictor responses to all the vasoactive agents were enhanced compared with those in SHR with intact renal nerves treated with carvedilol. Intact SHR given both losartan and carvedilol showed greater renal vasoconstrictor responses to the vasoactive agents than when given either losartan or carvedilol alone (allP < 0.05).

Conclusion: Carvedilol reduced the vasoconstrictor response to Ang II and all the adrenergic agonists in the presence of the renal nerves, but, following the removal of renal sympathetic activity, carvedilol enhanced the sensitivity of both renal α1‐adrenoceptors and AT1receptors to the vasoactive agents. Co‐treatment with losartan and carvedilol reduced the renal vasoconstrictor responses to exogenously administered vasoactive agents but to a lesser extent than losartan or carvedilol alone. The results obtained demonstrate an interaction between Ang II receptors and adrenergic neurotransmission in the SHR.
Comparison of Primary Flow Measurement Techniques Used During Combined Cycle Tests
Authors: Campbell W. Cary , Hopson Warren H. , Smith Mark A.
Published: August 2008

One of the most significant contributors to the overall uncertainty of a performance test of a combined cycle steam turbine is the uncertainty of the primary flow measurement. ASME performance test codes provide many alternative methods for determining flow. In two actual combined cycle tests performed in 2005, the following three alternate methods were used to determine the high-pressure (HP) steam flow into the combined cycle steam turbines: (1) Derivation from measured HP feedwater flow using calibrated PTC 6 throat tap nozzles, (2) derivation from low-pressure (LP) condensate using calibrated PTC 6 throat tap nozzles, and (3) derivation from LP condensate using calibrated orifice metering sections. This paper describes the design, calibration, and installation of each flow meter involved, the methods used to calculate the HP steam flow, the estimated uncertainty of the HP steam flow derived using each method, and the actual test results using each method. A comparison of the methods showed that there are distinct advantages with one of the methods and that very low uncertainties in HP steam flow can be achieved if sufficient attention is applied to the design, calibration, and installation of all flow meters involved. Note that the information in this paper was originally published in ASME Paper PWR2006-88074 and presented at the 2006 ASME Power Conference in Atlanta, GA. For detailed diagrams, figures, and tabulations of data and analysis, please refer to the published proceedings from that conference.
Experimental Analysis of Air∕Oil Separator Performance
Authors: Willenborg K. , Klingsporn M. , Tebby S. , Ratcliffe T. , Gorse P. , Dullenkopf K. , Wittig S.
Published: August 2008

Within the European research project (Advanced Transmission and Oil System Concepts), a systematic study of the separation efficiency of a typical aeroengine air∕oil separator design was conducted. The main objectives were to obtain a basic understanding of the main separation mechanisms and to identify the relevant parameters affecting the separation efficiency. The results of the study contribute to an optimized separator technology. Nonintrusive optical measurement techniques like laser diffraction and multiple wavelength extinction were applied to analyze the separation efficiency and identify potential optimization parameters. Oil mist with defined oil droplet size distribution was supplied to the breather. By simultaneously measuring particle size and oil concentration upstream and downstream of the breather, the separation mechanism was analyzed and the separation efficiency was assessed. In addition, the pressure drop across the separator was measured. The pressure drop is an important design feature and has to be minimized for proper sealing of the engine bearing chambers. The experimental programe covered a variation of air flow, oil flow, shaft speed, and droplet size. The main emphasis of the investigations was on the separation of small droplets with a diameter of up to 10μm. The following trends on separation efficiency of small droplets were observed: The separation efficiency increases with increasing rotational speed, with increasing particle size, and with decreasing air flow rate. In parallel, the pressure drop across the breather increases with increasing speed and increasing air flow.
Analysis of the Interactions Between Indicated and Reciprocating Torques for the Development of a Torsional Behavior Model of the Powertrain
Authors: Ponti Fabrizio , Solieri Luca
Published: August 2008

Torque-based engine control systems usually employ a produced torque estimation feedback in order to verify that the strategy target torque has been met. Torque estimation can be performed using static maps describing the engine behavior or using models describing the existing relationships between signals measured on the engine and the indicated torque produced. Signals containing information on the combustion development, suitable for this purpose, are, among others, the ion-current signal, the vibration signals obtained from accelerometers mounted on the engine block, or the instantaneous engine speed fluctuations. This paper presents the development and the identification process of an engine-driveline torsional behavior model that enables indicated torque estimation from instantaneous engine speed measurement. Particular attention has been devoted to the interactions between indicated and reciprocating torques, and their effects over instantaneous engine speed fluctuations. Indicated and reciprocating torques produce, in fact, opposite excitations on the driveline that show opposite effects on the engine speed wave form: For low engine speed, usually indicated torque prevails, while the opposite applies for higher engine speed. In order to correctly estimate indicated torque from engine speed measurement, it is therefore necessary to correctly evaluate the reciprocating torque contribution. Reciprocating torque is usually described using a wave form as a function of crank angle, while its amplitude depends on the value of the reciprocating masses. As mentioned before, knowledge of the reciprocating masses is fundamental in order to obtain correct estimation of the indicated torque. The identification process that has been set up for the engine-driveline torsional model enables to evaluate the relationship between torques applied to the engine and the corresponding engine speed wave form even without knowing the value of the reciprocating masses. In addition, once this model has been set up, it is possible to estimate with high precision the value of the reciprocating masses. Particular attention has also been devoted to the feasibility of the application of the identified model onboard for torque estimation; for this reason, the model has been developed in a very simple form. The approach proved to be effective both on gasoline and diesel engines, both for engine mounted on a test cell and onboard, with different engine configurations. Examples of application are given for some of the configurations investigated.
Parametric Studies on Dynamic Performance of Hybrid Airfoil Bearing
Authors: Kumar Manish , Kim Daejong
Published: August 2008

Airfoil bearings offer many advantages over oil-lubricated bearings, but they have reliability issues during start∕stops (wear) and limited heat dissipation capability. To address these issues, a hybrid airfoil bearing (HAFB) combining hydrodynamic airfoil bearing with hydrostatic lift was introduced previously by one of the authors of this paper. Their studies show that HAFB has superior performance compared to its hydrodynamic counterpart in load capacity and cooling performance. In this article, the bearing stiffness and damping coefficients of HAFB are calculated using a linear perturbation method developed for HAFB. Simulations showed that feed parameter and supply pressure affect the dynamic characteristics of HAFB. With an increase in either the supply pressure or the feed parameter, the rotor centers itself and hence one sees a decrease in direct stiffness. Simulations showed that the cross-coupled stiffness could be reduced by increasing either the supply pressure or the feed parameter. Direct damping showed increasing trend with the supply pressure and the feed parameter. Frequency-domain analysis of the bearing coefficients was also performed. The direct damping showed marginal changes with supply pressure but showed rapid increase with increasing excitation frequencies. The damping converged to null values for all the pressures for supersynchronous excitations. The loss in damping with high stiffness values for high frequency excitation is a typical hardening effect of gas bearings. In almost all the cases, there are rapid decreases in cross-coupled stiffness and damping and the values show converging trends in supersynchronous regime.
A Real-World Application of Fuzzy Logic and Influence Coefficients for Gas Turbine Performance Diagnostics
Authors: Eustace Richard W.
Published: August 2008

This paper presents an example of the use of fuzzy logic combined with influence coefficients applied to engine test-cell data to diagnose gas-path related performance faults. The approach utilizes influence coefficients, which describe the changes in measurable parameters due to changes in component condition such as compressor efficiency. Such approaches usually have the disadvantages of attributing measurement noise or sensor errors to changes in engine condition and do not have the ability to diagnose more faults than the number of measurement parameters that exist. These disadvantages usually make such methods impractical for anything but simulated data without measurement noise or errors. However, in this example, the influence coefficients are used in an iterative approach, in combination with fuzzy logic, to overcome these obstacles. The method is demonstrated using eight examples from real-world test-cell data.
An Energy-Based Uniaxial Fatigue Life Prediction Method for Commonly Used Gas Turbine Engine Materials
Authors: Scott-Emuakpor Onome E. , Shen Herman , George Tommy , Cross Charles
Published: August 2008

A new energy-based life prediction framework for calculation of axial and bending fatigue results at various stress ratios has been developed. The purpose of the life prediction framework is to assess the behavior of materials used in gas turbine engines, such as Titanium 6Al-4V (Ti 6Al-4V) and Aluminum 6061-T6 (Al 6061-T6). The work conducted to develop this energy-based framework consists of the following entities: (1) a new life prediction criterion for axial and bending fatigue at various stress ratios for Al 6061-T6, (2) the use of the previously developed improved uniaxial energy-based method to acquire fatigue life prior to endurance limit region (Scott-Emuakpor et al., 2007, “Development of an Improved High Cycle Fatigue Criterion,” ASME J. Eng. Gas Turbines Power, 129, pp. 162–169), (3) and the incorporation of a probabilistic energy-based fatigue life calculation scheme to the general uniaxial life criterion (the first entity of the framework), which is capable of constructing prediction intervals based on a specified percent confidence level. The precision of this work was verified by comparison between theoretical approximations and experimental results from recently acquired Al 606-T6 and Ti 6Al-4V data. The comparison shows very good agreement, thus validating the capability of the framework to produce accurate uniaxial fatigue life predictions for commonly used gas turbine engine materials.
Laminar Flame Speeds and Strain Sensitivities of Mixtures of H2∕O2∕N2 at Elevated Preheat Temperatures
Authors: Natarajan J. , Lieuwen T. , Seitzman J.
Published: August 2008

Laminar flame speeds and strain sensitivities of mixtures of H2 and air or air highly diluted with N2 (O2:N2 1:9) have been measured for a range of equivalence ratios at high preheat conditions (∼700K) using a nozzle generated, 1D, laminar, wall stagnation flame. The measurements are compared with numerical predictions based on three detailed kinetic models (GRIMECH 3.0, a H2∕CO mechanism from Davis et al. (2004, “An Optimized Kinetic Model of H2∕CO Combustion,” Proc. Combust. Inst., 30, pp. 1283–1292) and a H2 mechanism from Li et al. (2004, “An Updated Comprehensive Kinetic Model of Hydrogen Combustion,” Int. J. Chem. Kinet., 36, pp. 566–575)). Sensitivity of the measurements to uncertainties in boundary conditions, e.g., wall temperature and nozzle velocity profile (plug or potential), is investigated through detailed numerical simulations and shown to be small. The flame speeds and strain sensitivities predicted by the models for preheated reactants are in reasonable agreement with the measurements for mixtures of H2 and standard air at very lean conditions. For H2 and N2 diluted air, however, all three mechanisms significantly overpredict the measurements, and the overprediction increases for leaner mixtures. In contrast, the models underpredict flame speeds for room temperature mixtures of H2 with both standard and N2 diluted air, based on comparisons with measurements in literature. Thus, we find that the temperature dependence of the hydrogen flame speed as predicted by all the models is greater than the actual temperature dependence (for both standard and diluted air). Finally, the models are found to underpredict the measured strain sensitivity of the flame speed for H2 burning in N2 diluted air, especially away from stoichiometric conditions.
Prediction of Combustion Parameters, Performance, and Emissions in Compressed Natural Gas and Gasoline SI Engines
Authors: Baratta Mirko , Catania Andrea E. , d’Ambrosio Stefano , Spessa Ezio
Published: August 2008

The simulation of heat release, flame propagation speeds, and pollutant formation was carried out in both a turbocharged compressed natural gas (CNG) engine and a multivalve naturally aspirated bifuel engine running on either CNG or gasoline. The predictive tool used for investigation is based on an enhanced fractal geometry concept of the flame front, which is able to capture the modulation of turbulent to laminar burning speed ratio throughout the overall combustion phase without introducing flame kernel growth or burnout submodels. The prediction model was applied to a wide range of engine speeds, loads, relative air-fuel ratios, and spark advances, and the obtained results were compared to experimental data. These latter were extracted from measured in-cylinder pressure by an advanced diagnostics technique that was previously developed by the authors. The results confirmed a quite accurate prediction of burning speed even without any kind of tuning, with respect to different currently available fractal as well as nonfractal approaches for the simulation of flame-turbulence interaction. Furthermore, the computational code proved to be capable of capturing the effects of fuel composition, different combustion-chamber concepts, and operating conditions on engine performance and emissions.
Investigation of Mixture Preparation Effects on Gasoline HCCI
Combustion Aided by Measurements of Wall Heat Flux
Authors: Chang Junseok , Filipi Zoran S. , Kuo Tang-Wei , Assanis Dennis N. , Najt Paul M. , Rask Rodney B.
Published: August 2008

Expanding the range of HCCI operation will be critical for maximizing the fuel economy benefits in future vehicle applications. The mixture stratification, both thermal and compositional, can have very tangible impact on HCCI combustion, and gaining a deeper insight into these effects is critical for expanding the HCCI range of operation. This paper presents results of the comprehensive experimental investigation of the mixture preparation effects on a single-cylinder gasoline HCCI engine with exhaust reinduction. The effects include the type of mixture preparation (external mixing versus direct injection), charge motion, and injection timing. A combination of pressure-based combustion diagnostics, emission analysis, and heat flux measurements on the combustion chamber wall quantifies the effects on combustion and provides insight into reasons for observed engine behavior. As an example, the instantaneous temperature and heat flux measurements show the fuel impingement locations and allow assessing the fuel film dynamics and their effect on mixture stratification. The effects of direct injection and partial closing of the swirl control valve are relatively small compared with extending the injection timing late into the intake process or completely closing the swirl control valve and allowing charge storage in the intake port.
Influence of Force Field Direction on Pressure Sensors Calibrated at
Up to 12,000 g
Authors: Uffrecht Wieland , Kaiser Erwin
Published: August 2008

The measurement of pressure within both stationary and rotating frames of reference is a fundamental requirement when studying the flow field through turbomachinery blading. Measurement of pressure within the rotating frame presents a particular challenge, as centrifugal acceleration of the sensor can have a significant impact on sensor calibration, and therefore accuracy of the resulting measurements. In this paper the telemetric calibration of pressure sensors at up to 12,000 g is described, and the impact on calibration of membrane size, sensor body shape, and sensor mounting direction is discussed. The program of work reported in this paper focuses on experimental issues associated with rotating pressure measurement. The combined effect of centrifugal load and pressure on integrally temperature compensated silicon pressure sensors is presented. Experimental results are given that provide insight into the influence of acceleration on pressure readings. Implementation of acceleration into sensor calibration is presented. Supplementary finite element calculations enable impact of sensor body shape to be taken into account during the evaluation of sensor acceleration-to-pressure sensitivity ratio. Different sensors with varied membrane sizes and acceleration force directions are examined and compared.
Hybrid Gas Bearings With Controlled Supply Pressure to Eliminate Rotor Vibrations While Crossing System Critical Speeds
Authors: San Andrés Luis , Ryu Keun
Published: August 2008

Microturbomachinery implements gas bearings in compact units of enhanced mechanical reliability. Gas bearings, however, have little damping and wear quickly during transient rub events. Flexure pivot tilting pad bearings offer little or no cross-coupled stiffnesses with enhanced rotordynamic stability; and when modified for hydrostatic pressurization, demonstrate superior rotordynamic performance over other bearing types. External pressurization stiffens gas bearings thus increasing system critical speeds, albeit reducing system damping. Most importantly, measurements demonstrate that external pressurization is not needed for rotor supercritical speed operation. In practice, the supply pressure could be shut off at high rotor speeds with substantial gains in efficiency. This paper introduces a simple strategy, employing an inexpensive air pressure regulator to control the supply pressure into the hybrid bearings, to reduce or even eliminate high amplitudes of rotor motion while crossing the system critical speeds. Rotor speed coast-down tests with the pressure controller demonstrate the effectiveness of the proposed approach. A simple on-off supply pressure control, i.e., a sudden increase in pressure while approaching a critical speed, is the best since it changes abruptly the bearing stiffness coefficients and moves the system critical speed to a higher speed. A rotordynamic analysis integrating predicted bearing force coefficients forwards critical speeds in agreement with the test results. Predicted rotor responses for the controlled supply conditions show an excellent correlation with measured data. The experiments validate the predictive tools and demonstrate the controllable rotordynamic characteristics of flexure pivot hybrid gas bearings.
Fate of the Nitrilotriacetic Acid-Fe(III) Complex during Photodegradation and Biodegradation by
Rhodococcus rhodochrous
Authors: Bunescu Andrei , Besse-Hoggan Pascale , Sancelme Martine , Mailhot Gilles , Delort Anne-Marie
Published: August 2008

Aminopolycarboxylic acids are ubiquitous in natural waters and wastewaters. They have the ability to form very stable water-soluble complexes with many metallic di- or trivalent ions. The iron complex nitrilotriacetic acid-Fe(III) (FeNTA) has been previously shown to increase drastically the rate of photo- and biodegradation of 2-aminobenzothiazole, an organic pollutant, by
Rhodococcus rhodochrous
. For this paper, the fate of FeNTA was investigated during these degradation processes. First, it was shown, using in situ
1
H nuclear magnetic resonance, that the complex FeNTA was biodegraded by
Rhodococcus rhodochrous
cells, but the ligand (NTA) alone was not. This result indicates that FeNTA was transported and biotransformed inside the cell. The same products, including iminodiacetic acid, glycine, and formate, were obtained during the photo- and biodegradation processes of FeNTA, likely because they both involve oxidoreduction mechanisms. When the results of the different experiments are compared, the soluble iron, measured by spectrophotometry, was decreasing when microbial cells were present. About 20% of the initial iron was found inside the cells. These results allowed us to propose detailed mechanistic schemes for FeNTA degradation by solar light and by
R. rhodochrous
.
Novel
Parachlamydia acanthamoebae
Quantification Method Based on Coculture with Amoebae
Authors: Matsuo Junji , Hayashi Yasuhiro , Nakamura Shinji , Sato Marie , Mizutani Yoshihiko , Asaka Masahiro , Yamaguchi Hiroyuki
Published: August 2008

Parachlamydia acanthamoebae
, belonging to the order
Chlamydiales
, is an obligately intracellular bacterium that infects free-living amoebae and is a potential human pathogen. However, no method exists to accurately quantify viable bacterial numbers. We present a novel quantification method for
P. acanthamoebae
based on coculture with amoebae.
P. acanthamoebae
was cultured either with
Acanthamoeba
spp. or with mammalian epithelial HEp-2 or Vero cells. The infection rate of
P. acanthamoebae
(amoeba-infectious dose [AID]) was determined by DAPI (4′,6-diamidino-2-phenylindole) staining and was confirmed by fluorescent in situ hybridization. AIDs were plotted as logistic sigmoid dilution curves, and
P. acanthamoebae
numbers, defined as amoeba-infectious units (AIU), were calculated. During culture, amoeba numbers and viabilities did not change, and amoebae did not change from trophozoites to cysts. Eight amoeba strains showed similar levels of
P. acanthamoebae
growth, and bacterial numbers reached ca. 1,000-fold (10
9
AIU preculture) after 4 days. In contrast, no increase was observed for
P. acanthamoebae
in either mammalian cell line. However, aberrant structures in epithelial cells, implying possible persistent infection, were seen by transmission electron microscopy. Thus, our method could monitor numbers of
P. acanthamoebae
bacteria in host cells and may be useful for understanding chlamydiae present in the natural environment as human pathogens.
Comparative Molecular Analysis of Endoevaporitic Microbial Communities
Authors: Sahl Jason W. , Pace Norman R. , Spear John R.
Published: August 2008

A phylogenetic comparison of microbial communities in hypersaline evaporites was conducted on crusts from Guerrero Negro, Mexico, and Lindsey Lake, New Mexico, using culture-independent rRNA gene sequence analysis. Many sequences were shared between evaporites, which suggests that similar environments select for specific microbial lineages from a global metacommunity.
Engineering of a Glycerol Utilization Pathway for Amino Acid Production by
Corynebacterium glutamicum
Authors: Rittmann Doris , Lindner Steffen N. , Wendisch Volker F.
Published: August 2008

The amino acid-producing organism
Corynebacterium glutamicum
cannot utilize glycerol, a stoichiometric by-product of biodiesel production. By heterologous expression of
Escherichia coli
glycerol utilization genes,
C. glutamicum
was engineered to grow on glycerol. While expression of the
E. coli
genes for glycerol kinase (
glpK
) and glycerol 3-phosphate dehydrogenase (
glpD
) was sufficient for growth on glycerol as the sole carbon and energy source, additional expression of the aquaglyceroporin gene
glpF
from
E. coli
increased growth rate and biomass formation. Glutamate production from glycerol was enabled by plasmid-borne expression of
E. coli glpF, glpK
, and
glpD
in
C. glutamicum
wild type. In addition, a lysine-producing
C. glutamicum
strain expressing
E. coli glpF, glpK
, and
glpD
was able to produce lysine from glycerol as the sole carbon substrate as well as from glycerol-glucose mixtures.
Heme Uptake by
Microscilla marina
and Evidence for Heme Uptake Systems in the Genomes of Diverse Marine Bacteria
Authors: Hopkinson Brian M. , Roe Kelly L. , Barbeau Katherine A.
Published: August 2008

The ability to acquire diverse and abundant forms of iron would be expected to confer a survival advantage in the marine environment, where iron is scarce. Marine bacteria are known to use siderophores and inorganic iron, but their ability to use heme, an abundant intracellular iron form, has only been examined preliminarily.
Microscilla marina
, a cultured relative of a bacterial group frequently found on marine particulates, was used as a model organism to examine heme uptake. Searches of the genome revealed analogs to known heme transport proteins, and reverse transcription-quantitative PCR analysis of these genes showed that they were expressed and upregulated under iron stress and during growth on heme.
M. marina
was found to take up heme-bound iron and could grow on heme as a sole iron source, supporting the genetic evidence for heme transport. Similar putative heme transport components were identified in the genomes of diverse marine bacteria. These systems were found in the genomes of many bacteria thought to be particle associated but were lacking in known free-living organisms (e.g.,
Pelagibacter ubique
and marine cyanobacteria). This distribution of transporters is consistent with the hydrophobic, light-sensitive nature of heme, suggesting that it is primarily available on phytoplankton or detritus or in nutrient-rich environments.
Identification of Critical Members in a Sulfidogenic Benzene-Degrading Consortium by DNA Stable Isotope Probing
Authors: Oka A. R. , Phelps C. D. , McGuinness L. M. , Mumford A. , Young L. Y. , Kerkhof L. J.
Published: August 2008

Stable isotope probing (SIP) was used to identify the active members in a benzene-degrading sulfidogenic consortium. SIP-terminal restriction fragment length polymorphism analysis indicated that a 270-bp peak incorporated the majority of the13C label and is a sequence closely related to that of clone SB-21 (GenBank accession no. AF029045). This target may be an important biomarker for anaerobic benzene degradation in the field.
Functional Expression and Subcellular Localization of the Aflatoxin Pathway Enzyme Ver-1 Fused to Enhanced Green Fluorescent Protein
Authors: Hong Sung-Yong , Linz John E.
Published: August 2008

Aflatoxin, a mycotoxin synthesized by
Aspergillus
spp., is among the most potent naturally occurring carcinogens known. Little is known about the subcellular organization of aflatoxin synthesis. Previously, we used transmission electron microscopy and immunogold labeling to demonstrate that the late aflatoxin enzyme OmtA localizes primarily to vacuoles in fungal cells on the substrate surface of colonies. In the present work, we monitored subcellular localization of Ver-1 in real time in living cells.
Aspergillus parasiticus
strain CS10-N2 was transformed with plasmid constructs that express enhanced green fluorescent protein (EGFP) fused to Ver-1. Analysis of transformants demonstrated that EGFP fused to Ver-1 at either the N or C terminus functionally complemented nonfunctional Ver-1 in recipient cells. Western blot analysis detected predominantly full-length Ver-1 fusion proteins in transformants. Confocal laser scanning microscopy demonstrated that Ver-1 fusion proteins localized in the cytoplasm and in the lumen of up to 80% of the vacuoles in hyphae grown for 48 h on solid media. Control EGFP (no Ver-1) expressed in transformants was observed in only 13% of the vacuoles at this time. These data support a model in which middle and late aflatoxin enzymes are synthesized in the cytoplasm and transported to vacuoles, where they participate in aflatoxin synthesis.
Antimicrobial Resistance in
Salmonella enterica
Serovar Heidelberg Isolates from Retail Meats, Including Poultry, from 2002 to 2006
Authors: Zhao S. , White D. G. , Friedman S. L. , Glenn A. , Blickenstaff K. , Ayers S. L. , Abbott J. W. , Hall-Robinson E. , McDermott P. F.
Published: August 2008

Salmonella enterica
serovar Heidelberg frequently causes food-borne illness in humans. There are few data on the prevalence, antimicrobial susceptibility, and genetic diversity of
Salmonella
serovar Heidelberg isolates in retail meats. We compared the prevalences of
Salmonella
serovar Heidelberg in a sampling of 20,295 meats, including chicken breast (
n
= 5,075), ground turkey (
n
= 5,044), ground beef (
n
= 5,100), and pork chops (
n
= 5,076), collected during 2002 to 2006. Isolates were analyzed for antimicrobial susceptibility and compared genetically using pulsed-field gel electrophoresis (PFGE) and PCR for the
bla
CMY
gene. A total of 298
Salmonella
serovar Heidelberg isolates were recovered, representing 21.6% of all
Salmonella
serovars from retail meats. One hundred seventy-eight (59.7%) were from ground turkey, 110 (36.9%) were from chicken breast, and 10 (3.4%) were from pork chops; none was found in ground beef. One hundred ninety-eight isolates (66.4%) were resistant to at least one compound, and 49 (16.4%) were resistant to at least five compounds. Six isolates (2.0%), all from ground turkey, were resistant to at least nine antimicrobials. The highest resistance in poultry isolates was to tetracycline (39.9%), followed by streptomycin (37.8%), sulfamethoxazole (27.7%), gentamicin (25.7%), kanamycin (21.5%), ampicillin (19.8%), amoxicillin-clavulanic acid (10.4%), and ceftiofur (9.0%). All isolates were susceptible to ceftriaxone and ciprofloxacin. All ceftiofur-resistant strains carried
bla
CMY
. PFGE using XbaI and BlnI showed that certain clones were widely dispersed in different types of meats and meat brands from different store chains in all five sampling years. These data indicate that
Salmonella
serovar Heidelberg is a common serovar in retail poultry meats and includes widespread clones of multidrug-resistant strains.
TRiFLe, a Program for In Silico Terminal Restriction Fragment Length Polymorphism Analysis with User-Defined Sequence Sets
Authors: Junier Pilar , Junier Thomas , Witzel Karl-Paul
Published: August 2008

We describe TRiFLe, a freely accessible computer program that generates theoretical terminal restriction fragments (T-RFs) from any user-supplied sequence set tailored to a particular group of organisms, sequences from clone libraries, or sequences from specific genes. The program allows a rapid identification of the most polymorphic enzymes, creates a collection of T-RFs for the data set, and can potentially identify specific T-RFs in T-RF length polymorphism (T-RFLP) patterns by comparing theoretical and experimental results. TRiFLE was used for analyzing T-RFLP data generated for the
amoA
and
pmoA
genes. The peaks identified in the T-RFLP patterns show an overlap of ammonia- and methane-oxidizing bacteria in the metalimnion of a subtropical lake.
TaqMan-Based Real-Time PCR Method for Detection of
Yersinia pseudotuberculosis
in Food
Authors: Lambertz S. Thisted , Nilsson C. , Hallanvuo S.
Published: August 2008

A sensitive and specific assay for detection of food-borne pathogenic
Yersinia pseudotuberculosis
was developed. The primer-probe set was designed to target a 157-bp sequence of the chromosomally located gene
ail
. The complete method, including an internal amplification control, was evaluated for several different food items.