bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of Monolithic YSZ Porous and Dense Layers through Multiple Slip Casting for Ceramic Fuel Cell Applications
Authors: Hanifi Amir Reza , Shinbine Alyssa , Etsell Thomas H. , Sarkar Partha
Published: March 2011

In this research YSZ porous support and thin dense functional electrolyte layers are fabricated via a slip‐casting method for fuel cell applications. The results show that calcination of YSZ starting powder is a crucial step in developing an effective porous structure having an interconnected void network for fuel cell applications. It is found that due to high surface area and high sinterability, as‐received Tosoh YSZ powder is not a suitable candidate for production of interconnected porous structures even with the addition of pore former. Calcination at 1300–1500°C coarsens the YSZ powder and leads to the growth of particles to 15–100 μm. However, subsequent ball milling of the calcined powder for 72 h reduces the particle size to 400–800 nm (∼240 nm for uncalcined Tosoh YSZ) and increases the subsequent surface area, correlating with the temperature of calcination. With high‐temperature calcination, it is possible to generate interconnected porous structures after sintering at temperatures lower than the calcination temperature. The bodies made of powder calcined at 1300°C become dense following sintering at 1350°C, which makes this material suitable as a dense fuel cell electrolyte. Using calcined powders, a multiple slip‐casting procedure enables a dense electrolyte to be coated directly on a highly porous support. With this simple and inexpensive technique, high‐quality strongly adhered YSZ layers can be engineered.
Effects of Impurity Oxygen Content in Raw Si Powder on Thermal and Mechanical Properties of Sintered Reaction‐Bonded Silicon Nitrides
Authors: Kusano Dai , Adachi Shigeru , Tanabe Gen , Hyuga Hideki , Zhou You , Hirao Kiyoshi
Published: March 2011

Sintered reaction‐bonded silicon nitrides (SRBSNs) were fabricated from commercially available low‐grade Si powder containing 1.6 mass% of impurity oxygen and 500 ppm of metallic impurities. Powder compacts of the raw Si powder doped with Y2O3 and MgO/MgSiN2 as sintering additives were nitrided at 1400°C for 8 h under a N2 pressure of 0.1 MPa, followed by postsintering at 1900°C for 6 h under a N2 pressure of 0.9 MPa. The SRBSN with Y2O3 and MgO as sintering additives had a four‐point bending strength of about 700 MPa, but lower thermal conductivity of about 89 W/m/K. Thermal conductivity could be improved to over 100 W/m/K without degrading the bending strength by replacing MgO with MgSiN2. It is thought that MgSiN2 decreased the amount of oxygen in the liquid phase formed during sintering, which resulted in reduced lattice oxygen content in the developed β‐Si3N4 grains. In addition, the SRBSN with Y2O3 and MgSiN2 additive exhibited high fracture toughness of about 9 MPa m1/2. These good properties were equivalent to those of the SRBSN fabricated by using a reagent‐grade high‐purity Si powder containing only 0.3 mass% of impurity oxygen.
Depression Effects of Al on Oxidation of Diamond During Sintering of Diamond/Borosilicate Glass Composites
Authors: Zhang Xianghong , Wang Yanhui , Zang Jianbing , Cheng Xiaozhe , Xu Xipeng , Lu Jing
Published: March 2011

Oxidization of diamond in the sintering process of diamond/glass composites results in uncontrolled expansion with many irregular pores and low bending strength of the tools. In this paper, Al powder was used as oxygen getter due to its excellent affinity with oxygen. Its oxidization product, Al2O3, entered into glass network. Consequently, oxidization of the grits was inhibited, and the wettability of diamond grits by the matrix improved. As a result, the expansion phenomenon was inhibited and the bending strength improved for all the composites. The minimum volume expansion rate and maximum bending strength were obtained for the composite with 4 wt% Al powder. This Al content resulted in a decrease of volume expansion rate from 175.2% to −10.9%, and an increase in bending strength from 11.3 to 75.1 MPa compared with the composite without Al powder.
A third H i 21-cm absorption system in the sight-line of MG J0414+0534: a redshift for Object X?
Authors: Curran S. J. , Whiting M. T. , Tanna A. , Bignell C. , Webb J. K.
Published: March 2011

We report the detection of the third Hi 21-cm absorber in the sight-line towards the z= 2.64 quasar MG J0414+0534 (4C+05.19). In addition to the absorption at the host redshift and in the z= 0.96 gravitational lens, we find, through a decimetre-wave spectral scan towards this source, strong absorption at z= 0.38. We believe this may be associated with ‘Object X’, an additional feature apparent in the field of the lensing galaxy and lensed images, on the basis of its close proximity to the quasar images and the possible detection of the [Oiii] doublet in a published optical spectrum. If real, the strength of the [Oiii] emission would suggest the presence of an active galactic nucleus, or a gas-rich galaxy undergoing rapid star formation, either of which is consistent with the strong outflows apparent in the 21-cm spectrum. Although this is the strongest intervening 21-cm absorber found to date (a column density of NHI≳ 1022 cm−2, for a modest Ts/f≳ 300 K), simultaneous observations failed to detect any of the 18-cm OH lines at the 21-cm redshift. This suggests that, as for the lensing galaxy, this is not the primary location of the intervening material responsible for the very red colour of MG J0414+0534.
Vulnerability Indicators of Sea Water Intrusion
Authors: Werner Adrian D. , Ward James D. , Morgan Leanne K. , Simmons Craig T. , Robinson Neville I. , Teubner Michael D.
Published: March 2011

In this paper, simple indicators of the propensity for sea water intrusion (SWI) to occur (referred to as “SWI vulnerability indicators”) are devised. The analysis is based on an existing analytical solution for the steady‐state position of a sharp fresh water‐salt water interface. Interface characteristics, that is, the wedge toe location and sea water volume, are used in quantifying SWI in both confined and unconfined aquifers. Rates‐of‐change (partial derivatives of the analytical solution) in the wedge toe or sea water volume are used to quantify the aquifer vulnerability to various stress situations, including (1) sea‐level rise; (2) change in recharge (e.g., due to climate change); and (3) change in seaward discharge. A selection of coastal aquifer cases is used to apply the SWI vulnerability indicators, and the proposed methodology produces interpretations of SWI vulnerability that are broadly consistent with more comprehensive investigations. Several inferences regarding SWI vulnerability arise from the analysis, including: (1) sea‐level rise impacts are more extensive in aquifers with head‐controlled rather than flux‐controlled inland boundaries, whereas the opposite is true for recharge change impacts; (2) sea‐level rise does not induce SWI in constant‐discharge confined aquifers; (3) SWI vulnerability varies depending on the causal factor, and therefore vulnerability composites are needed that differentiate vulnerability to such threats as sea‐level rise, climate change, and changes in seaward groundwater discharge. We contend that the approach is an improvement over existing methods for characterizing SWI vulnerability, because the method has theoretical underpinnings and yet calculations are simple, although the coastal aquifer conceptualization is highly idealized.
Feasibility of Deep Nutrients Delivery into a Prince William Sound Beach for the Bioremediation of the Exxon Valdez Oil Spill
Authors: Boufadel Michel C. , Bobo Adane M. , Xia Yuqiang
Published: March 2011

Delivery of dissolved chemicals to potentially bioremediate oil from the Exxon Valdez oil spill was investigated at Smith Island, Prince William Sound, Alaska. Two transects for tracer application were installed: one at a clean area and another at an oiled area. Tracer delivery occurred under ambient pressure through manifolds. Lithium in LiBr/sea water solution was the inert tracer, and the solution (82.6 mg/L of lithium) was released at a flow rate of 0.23 L/min for 58.5 h. While maintaining the flow rate, the solution was switched to sea water (i.e., 0.0 mg/L of lithium) for 16 h. The results show that the tracer moved landward with rising tides and seaward with falling tides. The plume got deeper moving landward and shallower moving seaward of the manifold. Thus, in situations where oil biodegradation is limited by the availability of nutrients or oxygen, applying these chemicals by this technique would allow them to reach entrapped oil seaward of the manifold from below. The seaward plume traveling speed (around 2.0 m/d) suggests that this technique is logistically feasible from a hydraulic point of view.
Phenomenal Concepts
Authors: Sundström Pär
Published: March 2011

It’s a common idea in philosophy that we possess concepts of a peculiar kind by which we can think about our conscious states in ‘inner’ and ‘direct’ ways, as for example, when I attend to the way a current pain feels and think about this feeling as such. Such ‘phenomenal concepts’ figure in a variety of theoretical contexts. The bulk of this article discusses their use in a certain strategy – thephenomenal concept strategy– for defending the physicalist view that conscious states are reducible to brain states. It also considers, more briefly, how phenomenal concepts have been used to defend dualism about consciousness, and how they have been used to explain our special access to our consciousness. It concludes with a discussion about whether, and in what more precise sense of the term, we at all possess ‘phenomenal concepts’ of our conscious states.
Wnt signalling in murine postnatal mammary gland development
Authors: Jardé T. , Dale T.
Published: March 2011

The mammary gland undergoes numerous developmental processes postnatally, from the elongation of the ductal tree‐like structure to pregnancy‐induced lobulo‐alveolar development. Mammary epithelial stem cells have been suggested to be central to the control of enormous tissue expansion and remodelling during phases of mammary development. The Wnt signalling pathway plays a critical role in these biological steps and is suggested to be involved in the maintenance of the stem cell population. This review provides insight into recent findings on the activity of Wnt signalling during ductal and lobular mammary development and discusses the potential interplay between Wnt signals and mammary stem cells in mice.
Biotechnological uses of enzymes from psychrophiles
Authors: Cavicchioli R. , Charlton T. , Ertan H. , Omar S. Mohd , Siddiqui K. S. , Williams T. J.
Published: March 2011

The bulk of the Earth's biosphere is cold (e.g. 90% of the ocean's waters are ≤ 5°C), sustaining a broad diversity of microbial life. The permanently cold environments vary from the deep ocean to alpine reaches and to polar regions. Commensurate with the extent and diversity of the ecosystems that harbour psychrophilic life, the functional capacity of the microorganisms that inhabitat the cold biosphere are equally diverse. As a result, indigenous psychrophilic microorganisms provide an enormous natural resource of enzymes that function effectively in the cold, and these cold‐adapted enzymes have been targeted for their biotechnological potential. In this review we describe the main properties of enzymes from psychrophiles and describe some of their known biotechnological applications and ways to potentially improve their value for biotechnology. The review also covers the use of metagenomics for enzyme screening, the development of psychrophilic gene expression systems and the use of enzymes for cleaning.
Assessment of extreme flood characteristics based on a dynamic‐stochastic model of runoff generation and the probable maximum discharge
Authors: Kuchment L.S. , Gelfan A.N.
Published: March 2011

A dynamic‐stochastic model of flood generation consisting of a distributed physically based model of snowmelt runoff genesis and a stochastic weather generator has been used for the assessment of extreme flood risk. Coupling this model with Monte‐Carlo simulations of meteorological series allows one to calculate long series of runoff hydrographs and the exceedance probabilities of flood peak discharges and volumes. The implementation of such a dynamic‐stochastic methodology may provide an improvement in extreme flood risk assessment in comparison with the traditional flood frequency analysis of the hydrological series. However, for very rare events, the uncertainty in estimating flood risk may increase significantly. To decrease this uncertainty, it has been suggested to combine the peak discharge series obtained by dynamic‐stochastic simulations with the probable maximum discharge (PMD) calculated through the physically based model of snowmelt runoff generation. This combination is achieved by fitting the estimated exceedance probabilities of simulated peak discharges by the Johnson distribution with the PMD as the parameter. The sensitivity of the fitted Johnson distribution to the errors of the PMD estimations is analysed. A case study in Russia is carried out for the Vyatka River basin (the catchment area is 124 000 km2).
The lichen genus Heterodermia (Physciaceae) in South America – a contribution including five new species
Authors: Moberg Roland
Published: March 2011

Thirty‐three species of the lichen genus Heterodermia in South America, mainly from Ecuador and Peru, are defined. Morphology, anatomy, chemistry, habitat, distribution and interrelation between the species are discussed. A key to the treated species is presented. Five species are described as new; Heterodermia andina, H. arvidssonii, H. badia, H. fertilis and H. parva. One new combination is proposed; H. spinigera. Two species are reported as new to South America, H. spathulifera and H subcitrina, and H. palpebrata is reported as new to USA.
Elatostema densistriolatum sp. nov., E. latistipulum sp. nov. and E. cyrtandrifolium var. hirsutum var. nov. (Urticaceae) from southwest China
Authors: Wu Zeng‐Yuan , Wang Wen‐Tsai , Wang Hong , Li De‐Zhu
Published: March 2011

Two new species and one new variety of Elatostema J. R. Forst. & G. Forst. (Urticaceae) are described from Yunnan and Xizang, China. Habitat details and morphological comparison with similar species are given and discussed. The new taxa proposed are: Elatostema densistriolatum W. T. Wang & Zeng. Y. Wu, E. latistipulum W. T. Wang & Zeng Y. Wu and E. cyrtandrifolium (Zoll. & Mor.) Miq. var. hirsutum W. T. Wang & Zeng Y. Wu.
Enhancement of radiographic images in patients with lung nodules
Authors: Rajab Maher I. , Eskandar Ayman A.
Published: March 2011

Detection of lung nodules in a chest Radiograph is very difficult due to sensitivity to noise, lighting, and similar disturbances of the blood vessels and trachea. Therefore, such images need to be carefully examined to identify and characterize lung lesions. However, human interpretations are usually contradictory and may cause confusion. Current works propose an image processing technique based on frequency domain processing to clarify X‐ray radiographic images taken in patients with a variety of lung lesions. The Picture Archiving and Communication Systems workstation allows transferring radiographic data from DICOM into JPEG image formats. In the preprocessing phase, the lung nodules are identified by an experienced chest radiologist and used for extracting regions of interest. Subsequently, low‐pass followed by emphasis high‐pass frequency filters are applied to enhance the images with appropriate cut‐off frequencies. It has been found that high‐frequency domain image filtering enhances the morphological features of lung masses. Enhanced images are then visually arbitrated by an expert radiologist. We found that the characteristics of lung lesions are easily identified after this process.
Frequency of blood type A, B, and AB in 515 domestic shorthair cats from the Lisbon area
Authors: Marques Cátia , Ferreira Marisa , Gomes Joana F. , Leitão Nuno , Costa Marta , Serra Pedro , Duarte Correia José H. , Pomba Constança F.
Published: March 2011

Background:The A, B, and AB feline blood types are recognized worldwide and their frequencies vary geographically and among breeds. Frequencies of feline blood types have been reported previously from northern Portugal; however, they are unknown in other parts of the country.

Objectives:This 13‐year retrospective study was undertaken to determine the frequency of feline blood types in domestic shorthair (DSH) cats from the Lisbon area of central Portugal.

Methods:Blood samples were obtained at the Veterinary Teaching Hospital of the Technical University of Lisbon and its Veterinary Blood Bank and at several veterinary clinics in the Lisbon area. Blood‐typing was performed by the classical agglutination assay or using a cartridge assay.

Results:The study population comprised 515 DSH cats of both sexes and various ages. Frequencies of blood types A, B, and AB were 97.5%, 2.1%, and 0.4%, respectively.

Conclusion:As in other parts of the world, this study showed a clear predominance of type‐A cats in the Lisbon area of Portugal.
Stability of hematologic analytes in monkey, rabbit, rat, and mouse blood stored at 4°C in EDTA using the ADVIA 120 hematology analyzer
Authors: Ameri Mehrdad , Schnaars Henry A. , Sibley John R. , Honor David J.
Published: March 2011

Background:The time from sampling to analysis can be delayed when blood samples are shipped to distant reference laboratories or when analysis cannot be readily performed.

Objective:The objective of this study was to evaluate the stability of hematologic analytes in blood samples from monkeys, rabbits, rats, and mice when samples were stored for up to 72 hours at 4°C.

Methods:Blood samples from 30 monkeys, 15 rabbits, 20 rats, and 30 mice were collected into EDTA‐containing tubes and were initially analyzed within 1 hour of collection using the ADVIA 120 analyzer. The samples were then stored at 4°C and reanalyzed at 24, 48, and 72 hours after collection.

Results:Significant (P<.0003) changes in hematologic analytes and calculations included increased HCT and MCV and decreased MCHC and cell hemoglobin concentration mean (CHCM) at 72 hours and increased MPV at 24 hours in monkeys; increased MCV at 72 hours and MPV at 48 hours and decreased monocyte count at 24 hours in rabbits; increased MCV and decreased MCHC, CHCM, and monocyte count at 24 hours in rats; increased MCV, red cell distribution width, and MPV and decreased MCHC, CHCM, and monocyte count at 24 hours in mice.

Conclusions:Although most of the changes in the hematologic analytes in blood from monkeys, rabbits, rats, and mice when samples were stored at 4°C were analytically acceptable and clinically negligible, the best practice in measuring hematologic analytes in these animals is timely processing of blood samples, preferably within 1 hour after collection.
Utility of measuring plasma N‐terminal pro‐brain natriuretic peptide in detecting hypertrophic cardiomyopathy and differentiating grades of severity in cats
Authors: Wess Gerhard , Daisenberger Patricia , Mahling Monia , Hirschberger Johannes , Hartmann Katrin
Published: March 2011

Background: Cats with hypertrophic cardiomyopathy (HCM) often have no clinical signs or subtle signs. Measurement of N‐terminal pro‐brain natriuretic peptide (NT‐proBNP) has been demonstrated in people to be highly specific for heart disease and also correlates with severity of HCM. NT‐proBNP may also be valuable in detecting and grading HCM in cats, but results to date have been equivocal.

Objectives: The aims of this study were to evaluate NT‐proBNP as a screening test for diagnosis of HCM in cats and determine an appropriate cut‐off value and to determine if NT‐proBNP concentrations correlated with severity of HCM in cats.

Methods: Plasma NT‐proBNP concentrations were measured in 201 cats using an ELISA designed for use in cats. Cats were classified using echocardiography as clinically healthy controls (n=99) or cats with equivocal (n=9), mild (n=15), moderate (n=17), or severe (n=61) HCM.

Results: NT‐proBNP concentrations (median; 25th–75th interquartile percentiles) in mildly (216.1; 87.6–392.5 pmol/L), moderately (282.7; 131.9–466.6 pmol/L), and severely (839.5; 655.3–1046.4 pmol/L) affected cats were significantly higher than those in healthy controls (18.9; 3.4–62.4 pmol/L). Concentrations in severely affected cats were significantly higher than in cats from other HCM groups. There was no significant difference between mild and moderate HCM. Cut‐off values >49 pmol/L had a sensitivity of 97.8% and specificity of 66.7%; >100 pmol/L had a sensitivity of 92.4% and specificity of 93.9%; and >150 pmol/L had a sensitivity of 88% and a specificity of 100%.

Conclusions: NT‐proBNP with a cut‐off value of >100 pmol/L was useful in detecting even mild HCM. Cats with increased NT‐proBNP concentrations should be examined by echocardiography.
Flattened chondrules in the LAP 04581 LL5 chondrite: Evidence for an oblique impact into LL3 material and subsequent collisional heating
Authors: RUBIN Alan E. , SWINDLE Timothy D.
Published: March 2011

Abstract– LaPaz Icefield (LAP) 04581 is a shock‐stage S2 LL5 chondrite that initially consisted of unrecrystallized LL3 material with a moderately abundant fine‐grained porous matrix (on the order of 15 vol%). A rare oblique impact created shearing stresses that produced a petrofabric in the rock, induced frictional melting of troilite (thereby forming a large troilite vein), and caused chondrule flattening. The latter process was facilitated by impact‐induced collapse of matrix pores. Chondrule flattening could not have occurred if the rock had been impacted after it had been metamorphosed to type 5 levels because the fine‐grained matrix would have previously recrystallized and developed low porosity. Ar‐Ar dating of LAP 04581 yields an age of 4175 Ma. This date is long after 26Al had decayed away and most likely reflects the timing of a second impact event that shocked the rock to S4–S5 levels. The troilite vein became polycrystalline at this time and the whole rock was annealed to petrologic type 5, perhaps by being buried beneath hot ejecta of low thermal diffusivity. After annealing, the rock was weakly shocked to S2 levels. LAP 04581 serves as an example of impact‐induced heating being a viable mechanism for chondrite metamorphism.
A synthetic cannabinoid, CP55940, inhibits lipopolysaccharide-induced cytokine mRNA expression in a cannabinoid receptor-independent mechanism in rat cerebellar granule cells
Authors: Chiba Toshiki , Ueno Sanae , Obara Yutaro , Nakahata Norimichi
Published: March 2011

Objectives

The inflammatory response plays an important role in the pathogenesis of many diseases in the central nervous system. Cannabinoids exhibit diverse pharmacological actions including anti-inflammatory activity. In this study, we tried to elucidate possible effects of cannabinoids on lipopolysaccharide (LPS)-induced expression of inflammatory cytokine mRNAs in rat cerebellar granule cells.

Methods

Inhibitory effects of cannabinoids on cytokine induction in cerebellar granule cells were determined by RT-PCR method.

Key findings

In these cells, both mRNA and protein of cannabinoid receptor 1 (CB1), but not CB2, were expressed. LPS (1 µg/ml) produced a marked increase in the induction of inflammatory cytokines, including interleukin-1β, interleukin-6 and tumour necrosis factor-α. CP55940, a synthetic cannabinoid analogue, concentration-dependently inhibited inflammatory cytokine expression induced by LPS. On the other hand, the endocannabinoids 2-arachidonoylglycerol and anandamide were not able to inhibit this inflammatory response. Notably, a CB1/CB2 antagonist NESS0327 (3 µm) did not reverse the inhibition of cytokine mRNA expression induced by CP55940. GPR55, a putative novel cannabinoid receptor, mRNA was also expressed in cerebellar granule cells. Although it has been suggested that Gq associates with GPR55, cannabinoids including CP55940 did not promote phosphoinositide hydrolysis and consequent elevation of intracellular Ca[2+] concentration. Furthermore, a putative GPR55 antagonist, cannabidiol, also showed a similar inhibitory effect to that of CP55940.

Conclusions

These results suggest that the synthetic cannabinoid CP55940 negatively modulates cytokine mRNA expression in cerebellar granule cells by a CB and GPR55 receptor-independent mechanism.
Vanishing of the μ-invariant of p-adic Hecke L-functions
Authors: Hida Haruzo
Published: March 2011

We prove vanishing of the μ-invariant of the p-adic Katz L-function in N. M. Katz [p-adic L-functions for CM fields, Invent. Math. 49 (1978), 199–297].
A New Magnetorheological Mount for Vibration Control
Authors: York David , Wang Xiaojie , Gordaninejad Faramarz
Published: March 2011

In this study, the performance of a new controllable mount design utilizing a magnetorheological material encapsulated in an elastomer matrix is investigated. A magnetorheological fluid-elastomer (MRF-E) mount is designed and fabricated, and its dynamic performance is studied under harmonic oscillatory vibrations for a wide range of frequencies and various applied magnetic fields. Also, a theoretical analysis is conducted by proposing a three-element phenomenological model for replicating the dynamic behavior of the MRF-E mount under oscillation loadings, and the results are compared with the experimental data. In order to further evaluate the effectiveness of the MRF-E mount for vibration control, a single degree-of-freedom (SDOF) system incorporated with this device is developed. Theoretically, the equation of motion utilizing the proposed phenomenological model is derived to provide performance predictions on the effectiveness of the semiactive device at suppressing unwanted vibrations. Experimentally, a SDOF system constrained to rectilinear motion and composed of a mass, four linear springs, and the MRF-E mount is designed and manufactured. This work demonstrates the performance of the proposed MRF-E mount and its capability in attenuating undesirable system vibrations for a range of small-displacement amplitudes and frequencies.
A Model-Based Methodology for Real-Time Estimation of Diesel Engine Cylinder Pressure
Authors: Al-Durra Ahmed , Canova Marcello , Yurkovich Stephen
Published: March 2011

Cylinder pressure is one of the most important parameters characterizing the combustion process in an internal combustion engine. The recent developments in engine control technologies suggest the use of cylinder pressure as a feedback signal for closed-loop combustion control. However, the sensors measuring in-cylinder pressure are typically subject to noise and offset issues, requiring signal processing methods to be applied to obtain a sufficiently accurate pressure trace. The signal conditioning implies a considerable computational burden, which ultimately limits the use of cylinder pressure sensing to laboratory testing, where the signal can be processed off-line. In order to enable closed-loop combustion control through cylinder pressure feedback, a real-time algorithm that extracts the pressure signal from the in-cylinder sensor is proposed in this study. The algorithm is based on a crank-angle based engine combustion of that predicts the in-cylinder pressure from the definition of a burn rate function. The model is then adapted to model-based estimation by applying an extended Kalman filter in conjunction with a recursive least-squares estimation scheme. The estimator is tested on a high-fidelity diesel engine simulator as well as on experimental data obtained at various operating conditions. The results obtained show the effectiveness of the estimator in reconstructing the cylinder pressure on a crank-angle basis and in rejecting measurement noise and modeling errors. Furthermore, a comparative study with a conventional signal processing method shows the advantage of using the derived estimator, especially in the presence of high signal noise (as frequently happens with low-cost sensors).
Switch-Mode Continuously Variable Transmission: Modeling and Optimization
Authors: Van de Ven James D. , Demetriou Michael A.
Published: March 2011

Hybrid vehicles are an important step toward reducing global petroleum consumption and greenhouse gas emissions. Flywheel energy storage in a hybrid vehicle combines high energy density and high power density, yet requires a highly efficient continuously variable transmission with a wide operating range. This paper presents a novel solution to coupling a high-speed flywheel to the drive train of a vehicle, the switch-mode continuously variable transmission (CVT). The switch-mode CVT, the mechanical analog of a boost converter from power electronics, utilizes a rapidly switching clutch to transmit energy from a flywheel to a spring, which applies a torque to the drive train. By varying the duty ratio of the clutch, the average output torque is controlled. This paper examines the feasibility of this concept by formulating a mathematical model of the switch-mode CVT, which is then placed in state-space form. The state-space formulation is leveraged to analyze the system stability and perform simple optimization of the switch time and damping rate of the spring over the first switching period. The results of this work are that a stable equilibrium does exist when the speed of the output shaft is zero, but the system will not reach and stay at a desired torque if this condition is not met, but requires continuous switching between the two states. An optimal switching time and damping ratio were found for the given parameters, where the lowest error occurred with low values of damping ratio. This work builds a foundation for future work in increasing the complexity of the model and the optimization method.
Oxygen Nonstoichiometry and Electrochemical Properties of GdBaCo2−xFexO6−δ Double Perovskite Cathodes
Authors: Tsvetkov Dmitry S. , Saricheva Nadezhda S. , Sereda Vladimir V. , Zuev Andrey Yu.
Published: March 2011

Mixed ionic- and electronic-conducting perovskite-type oxides are the state-of-the-art materials for high-temperature solid-state electrochemical devices such as solid oxide fuel cells (SOFCs), oxygen membranes, and sensors. Many of such materials are cobaltite-based oxides. Recently, double perovskites REBaCo2O5.5±δ, where RE is a trivalent rare earth and the oxygen content δ varies in wide range, have received a great attention as attractive materials for such application. Many interesting phenomena, such as giant magnetoresistance, charge ordering, and metal-insulator transition, have been observed in these compounds. Powder samples of GdBaCo2−xFexO6−δ(x=0;0.2) were synthesized by glycerol-nitrate method. Oxygen nonstoichiomentry of oxides GdBaCo2−xFexO6−δ(x=0;0.2) was measured by the thermogravimetric (TG) method as a function of temperature in the range of 25–1100°C in air. Total conductivity of aforementioned oxides was studied by the four-probe dc-method as a function of temperature in the range of 25–1100°C in air. Polarization resistance of double perovskite cathodes was investigated by impedance spectroscopy in symmetrical cell of the type electrode|electrolyte|electrode. “Metal-insulator” transition was found at 80°C in GdBaCo2O6−δ, whereas it was not observed in iron-doped sample GdBaCo1.8Fe0.2O6−δ due to the increase in oxygen content upon Fe-doping. At high temperatures, both double perovskites have almost the same total conductivity. Chemical interaction was found to decrease the performance of GdBaCo2−xFexO6−δ cathodes in YSZ-based SOFCs due to the chemical interaction between electrolyte and cathode materials, which significantly increases their polarization resistance. Behavior of total conductivity of oxides GdBaCo2−xFexO6−δ(x=0;0.2) with temperature was explained by assuming small polaron charge transfer. The particularity of the latter is larger mobility of electron holes as compared with that of electrons. Increase in cathode performance was shown in the case of YSZ covered by the Ce0.8Sm0.2O2 layer in comparison with pure Zr0.9Y0.1O2 electrolyte.
Reaction mechanisms of thermal atomic oxygen interaction with organosilicate low k dielectric materials from ab initio molecular dynamics simulations
Authors: Chaudhari Mrunalkumar , Du Jincheng
Published: March 2011

The interactions of the oxidizing plasma with the low k dielectric materials and the associated damage mechanisms are of great technological interest for processing current and next generation low k materials. Density functional theory based ab initio molecular dynamics simulations have been performed to evaluate the reaction mechanisms of thermal atomic oxygen [in triplet (P3) or singlet (D1) state] with the organosilicate low k materials represented by model systems. The threshold kinetic energies of attacking atomic oxygen and the reaction pathway were found to be highly incident angle dependent. Carbon abstraction through methyl radical formation can happen at energy barriers as low as 0.1 eV when O radical attack occurs along the axes inclined to the Si–C bond. The simulation results agree well with recent experiments and support diffusion-controlled etching rate dependence, and dielectric constant increases due to oxygen plasma etching.
Spectral method for the correction of the Cerenkov light effect in plastic scintillation detectors: A comparison study of calibration procedures and validation in Cerenkov light‐dominated situations
Authors: Guillot Mathieu , Gingras Luc , Archambault Louis , Beddar Sam , Beaulieu Luc
Published: March 2011

Purpose:

The purposes of this work were: (1) To determine if a spectral method can accurately correct the Cerenkov light effect in plastic scintillation detectors (PSDs) for situations where the Cerenkov light is dominant over the scintillation light and (2) to develop a procedural guideline for accurately determining the calibration factors of PSDs.

Methods:

The authors demonstrate, by using the equations of the spectral method, that the condition for accurately correcting the effect of Cerenkov light is that the ratio of the two calibration factors must be equal to the ratio of the Cerenkov light measured within the two different spectral regions used for analysis. Based on this proof, the authors propose two new procedures to determine the calibration factors of PSDs, which were designed to respect this condition. A PSD that consists of a cylindrical polystyrene scintillating fiber coupled to a plastic optical fiber was calibrated by using these new procedures and the two reference procedures described in the literature. To validate the extracted calibration factors, relative dose profiles and output factors for a 6 MV photon beam from a medical linac were measured with the PSD and an ionization chamber. Emphasis was placed on situations where the Cerenkov light is dominant over the scintillation light and on situations dissimilar to the calibration conditions.

Results:

The authors found that the accuracy of the spectral method depends on the procedure used to determine the calibration factors of the PSD and on the attenuation properties of the optical fiber used. The results from the relative dose profile measurements showed that the spectral method can correct the Cerenkov light effect with an accuracy level of 1%. The results obtained also indicate that PSDs measure output factors that are lower than those measured with ionization chambers for square field sizes larger than , in general agreement with previously published Monte Carlo results.

Conclusions:

The authors conclude that the spectral method can be used to accurately correct the Cerenkov light effect in PSDs. The authors confirmed the importance of maximizing the difference of Cerenkov light production between calibration measurements. The authors also found that the attenuation of the optical fiber, which is assumed to be constant in the original formulation of the spectral method, may cause a variation of the calibration factors in some experimental setups.
Mutations in the RNA Granule Component TDRD7 Cause Cataract and Glaucoma
Authors: Lachke Salil A. , Alkuraya Fowzan S. , Kneeland Stephen C. , Ohn Takbum , Aboukhalil Anton , Howell Gareth R. , Saadi Irfan , Cavallesco Resy , Yue Yingzi , Tsai Anne C-H. , Nair K. Saidas , Cosma Mihai I. , Smith Richard S. , Hodges Emily , AlFadhli Suad M. , Al-Hajeri Amal , Shamseldin Hanan E. , Behbehani AbdulMutalib , Hannon Gregory J. , Bulyk Martha L. , Drack Arlene V. , Anderson Paul J. , John Simon W. M. , Maas Richard L.
Published: March 2011

A Tudor domain protein mediates posttranscriptional control of gene expression and is required for eye-lens development.
FGF19 as a Postprandial, Insulin-Independent Activator of Hepatic Protein and Glycogen Synthesis
Authors: Kir Serkan , Beddow Sara A. , Samuel Varman T. , Miller Paul , Previs Stephen F. , Suino-Powell Kelly , Xu H. Eric , Shulman Gerald I. , Kliewer Steven A. , Mangelsdorf David J.
Published: March 2011

Fibroblast growth factor 19 regulates liver metabolism through a mechanism distinct from that of insulin.
Early Pleistocene Presence of Acheulian Hominins in South India
Authors: Pappu Shanti , Gunnell Yanni , Akhilesh Kumar , Braucher Régis , Taieb Maurice , Demory François , Thouveny Nicolas
Published: March 2011

Dates from a site in southeast India imply an early migration of
Homo
through Eurasia about 1.1 to 1.5 million years ago.
Impacts of Salmon on Riparian Plant Diversity
Authors: Hocking Morgan D. , Reynolds John D.
Published: March 2011

A survey of Canadian forests reveals the effects of nutrient subsidies from salmon on plant community structure.
The Buttermilk Creek Complex and the Origins of Clovis at the Debra L. Friedkin Site, Texas
Authors: Waters Michael R. , Forman Steven L. , Jennings Thomas A. , Nordt Lee C. , Driese Steven G. , Feinberg Joshua M. , Keene Joshua L. , Halligan Jessi , Lindquist Anna , Pierson James , Hallmark Charles T. , Collins Michael B. , Wiederhold James E.
Published: March 2011

A large artifact assemblage dating to 15,000 years ago lies beneath a Clovis assemblage in central Texas.
A Better View of Eras of Life

Principles of Social Evolution
by Andrew F. G. Bourke

Oxford University Press, Oxford, 2011. 279 pp. $117, £65. ISBN 9780199231157. Paper, $52.95, £29.95. ISBN 9780199231164. Oxford Series in Ecology and Evolution.
Authors: West Stuart
Published: March 2011

Synthesizing theoretical and empirical perspectives, Bourke presents an expanded view of social evolution to explain the major transitions between successive levels in the biological hierarchy.
Exploring the Genomes of Cancer Cells: Progress and Promise
Authors: Stratton Michael R.
Published: March 2011

The description and interpretation of genomic abnormalities in cancer cells have been at the heart of cancer research for more than a century. With exhaustive sequencing of cancer genomes across a wide range of human tumors well under way, we are now entering the end game of this mission. In the forthcoming decade, essentially complete catalogs of somatic mutations will be generated for tens of thousands of human cancers. Here, I provide an overview of what these efforts have revealed to date about the origin and behavioral features of cancer cells and how this genomic information is being exploited to improve diagnosis and therapy of the disease.
A Helix for the Final Cut
Authors: Raiborg Camilla , Stenmark Harald
Published: March 2011

The constriction of a protein helix and the action of a microtubule-severing enzyme trigger the final stage of separation during cell division.
The Challenge of Cancer
Authors: Alberts Bruce
Published: March 2011

This special issue of
Science
focuses on cancer, a disease that takes a terrible human toll. For scientists, preventing and curing this disease present an enormous challenge. We all know someone who suffers from cancer, and there is always pressure on researchers to focus on the immediate development of better treatments. But it is also essential to invest in innovative, longer-term efforts designed to generate more powerful approaches.
Peak Oil Production May Already Be Here
Authors: Kerr Richard A.
Published: March 2011

Outside of OPEC's vast resources, oil production has leveled off, and it's looking like it may never rise again.
Can Treatment Costs Be Tamed?
Authors: Malakoff David
Published: March 2011

More patients and the rising costs of new cancer treatments spark debate over how much is too much—and who should decide.
A Push to Fight Cancer in the Developing World
Authors: Enserink Martin
Published: March 2011

Cancer and other chronic diseases have received little attention from global health advocates. That's beginning to change.
HGP44 Induces Protection against Porphyromonas gingivalis-Induced Alveolar Bone Loss in Mice
Authors: Muramatsu Kyotaro , Kokubu Eitoyo , Shibahara Takahiko , Okuda Katsuji , Ishihara Kazuyuki
Published: March 2011

The protective effect of DNA vaccines expressing the Arg-gingipain A domain against bone loss induced byPorphyromonas gingivalisinfection was investigated in a murine model. phgp44, which expresses the 44-kDa adhesion/hemagglutinin domain of Arg-gingipain A, preventedP. gingivalis-induced alveolar bone loss. The results indicate that phgp44 could be a candidate antigen for a vaccine againstP. gingivalisinfection.
Serum (1→3)-β-
d
-Glucan Levels in Primary Infection and Pulmonary Colonization with Pneumocystis jirovecii
Authors: Damiani Céline , Le Gal Solène , Lejeune Delphine , Brahimi Naima , Virmaux Michèle , Nevez Gilles , Totet Anne
Published: March 2011

This article describes positive (1→3)-β-
d
-glucan levels in serum from infants with primary
Pneumocystis
infection and from immunosuppressed patients with
Pneumocystis
pneumonia (PCP) and negative levels in serum from patients colonized by
Pneumocystis jirovecii
. Glucan detection is a complementary tool for the diagnosis of the diverse clinical presentations of
P. jirovecii
infection.
Highly Specific and Quick Detection of Mycobacterium avium subsp. paratuberculosis in Feces and Gut Tissue of Cattle and Humans by Multiple Real-Time PCR Assays
Authors: Imirzalioglu Can , Dahmen Heinrich , Hain Torsten , Billion Andre , Kuenne Carsten , Chakraborty Trinad , Domann Eugen
Published: March 2011

Mycobacterium avium
subsp.
paratuberculosis
is the causative agent of Johne's disease (JD) in cattle and may be associated with Crohn's disease (CD) in humans. It is the slowest growing of the cultivable mycobacteria, and culture from clinical, veterinary, food, or environmental specimens can take 4 months or even longer. Currently, the insertion element IS
900
is used to detect
M. avium
subsp.
paratuberculosis
DNA. However, closely related IS
900
elements are also present in other mycobacteria, thus limiting its specificity as a target. Here we describe the use of novel primer sets derived from the sequences of two highly specific single copy genes, MAP2765c and MAP0865, for the quantitative detection of
M. avium
subsp.
paratuberculosis
within 6 h by using real-time PCR. Specificity of the target was established using 40
M. avium
subsp.
paratuberculosis
isolates, 67 different bacterial species, and two intestinal parasites. Using the probes and methods described, we detected 27 (2.09%)
M. avium
subsp.
paratuberculosis
-positive stool specimens from 1,293 individual stool samples by the use of either IS
900
or probes deriving from the MAP2765c and MAP0865 genes described here. In general, bacterial load due to
M. avium
subsp.
paratuberculosis
was uniformly low in these samples and we estimated 500 to 5,000
M. avium
subsp.
paratuberculosis
bacteria per gram of stool in assay-positive samples. Thus, the methods described here are useful for rapid and specific detection of
M. avium
subsp.
paratuberculosis
in clinical samples.
Genome-Wide Histone Acetylation Profiling of Herpesvirus saimiri in Human T Cells upon Induction with a Histone Deacetylase Inhibitor
Authors: Alberter Barbara , Vogel Benjamin , Lengenfelder Doris , Full Florian , Ensser Armin
Published: March 2011

Herpesviruses establish latency in suitable host cells after primary infection and persist in their host organisms for life. Most of the viral genes are silenced during latency, also enabling the virus to escape from an immune response. This study addresses the control of viral gene silencing by epigenetic mechanisms, using
Herpesvirus saimiri
(HVS) as a model system. Strain C488 of this gamma-2-herpesvirus can transform human T cells to stable growth
in vitro
, and it persists in the nuclei of those latently infected T cells as a nonintegrating, circular, and histone-associated episome. The whole viral genome was probed for histone acetylation at high resolution by chromatin immunoprecipitation-on-chip (ChIP-on-chip) with a custom tiling microarray. Corresponding to their inactive status in human T cells, the lytic promoters consistently revealed a heterochromatic phenotype. In contrast, the left terminal region of the genome, which encodes the stably expressed oncogenes
stpC
and
tip
as well as the herpesvirus U RNAs, was associated with euchromatic histone acetylation marks representing “open” chromatin. Although HVS latency in human T lymphocytes is considered a stable and irreversible state, incubation with the histone deacetylase inhibitor trichostatin A resulted in changes reminiscent of the induction of early lytic replication. However, infectious viral particles were not produced, as the majority of cells went into apoptosis. These data show that epigenetic mechanisms are involved in both rhadinoviral latency and transition into lytic replication.
An Optimal
cis
-Replication Stem-Loop IV in the 5′ Untranslated Region of the Mouse Coronavirus Genome Extends 16 Nucleotides into Open Reading Frame 1
Authors: Guan Bo-Jhih , Wu Hung-Yi , Brian David A.
Published: March 2011

The 288-nucleotide (nt) 3′ untranslated region (UTR) in the genome of the bovine coronavirus (BCoV) and 339-nt 3′ UTR in the severe acute respiratory syndrome (SARS) coronavirus (SCoV) can each replace the 301-nt 3′ UTR in the mouse hepatitis coronavirus (MHV) for virus replication, thus demonstrating common 3′
cis
-replication signals. Here, we show that replacing the 209-nt MHV 5′ UTR with the ∼63%-sequence-identical 210-nt BCoV 5′ UTR by reverse genetics does not yield viable virus, suggesting 5′ end signals are more stringent or possibly are not strictly 5′ UTR confined. To identify potential smaller, 5′-common signals, each of three stem-loop (SL) signaling domains and one inter-stem-loop domain from the BCoV 5′ UTR was tested by replacing its counterpart in the MHV genome. The SLI/II domain (nucleotides 1 to 84) and SLIII domain (nucleotides 85 to 141) each immediately enabled near-wild-type (wt) MHV-like progeny, thus behaving similarly to comparable 5′-proximal regions of the SCoV 5′ UTR as shown by others. The inter-stem-loop domain (nt 142 to 173 between SLs III and IV) enabled small plaques only after genetic adaptation. The SLIV domain (nt 174 to 210) required a 16-nt extension into BCoV open reading frame 1 (ORF1) for apparent stabilization of a longer BCoV SLIV (nt 174 to 226) and optimal virus replication. Surprisingly, pleiomorphic SLIV structures, including a terminal loop deletion, were found among debilitated progeny from intra-SLIV chimeras. The results show the inter-stem-loop domain to be a potential novel species-specific
cis
-replication element and that
cis
-acting SLIV in the viral genome extends into ORF1 in a manner that stabilizes its lower stem and is thus not 5′ UTR confined.