bluuebunny/crossref_metadata_2025 huggingface dataset:
Perception of echo delay is disrupted by small temporal misalignment of echo harmonics in bat sonar
Authors: Bates Mary E. , Simmons James A.
Published: January 2011

Echolocating big brown bats emit ultrasonic frequency-modulated (FM) biosonar sounds containing two prominent downward-sweeping harmonics (FM1 and FM2) and perceive target distance from echo delay. In naturally occurring echoes, FM1 and FM2 are delayed by the same amount. Even though echoes from targets located off-axis or far away are lowpass filtered, which weakens FM2 relative to FM1, their delays remain the same. We show here that misalignment of FM2 with FM1 by only 2.6 μs is sufficient to significantly disrupt acuity, which then persists for larger misalignments up to 300 μs. However, when FM2 is eliminated entirely rather than just misaligned, acuity is effectively restored. For naturally occurring, lowpass-filtered echoes, neuronal responses to weakened FM2 are retarded relative to FM1 because of amplitude-latency trading, which misaligns the harmonics in the bat's internal auditory representations. Electronically delaying FM2 relative to FM1 mimics the retarded neuronal responses for FM2 relative to FM1 caused by amplitude-latency trading. Echoes with either electronically or physiologically misaligned harmonics are not perceived as having a clearly defined delay. This virtual collapse of delay acuity may suppress interference from off-axis or distant clutter through degradation of delay images for clutter in contrast to sharp images for nearer, frontal targets.
Propulsion efficiency and imposed flow fields of a copepod jump
Authors: Jiang Houshuo , Kiørboe Thomas
Published: January 2011

Pelagic copepods jump to relocate, to attack prey and to escape predators. However, there is a price to be paid for these jumps in terms of their energy costs and the hydrodynamic signals they generate to rheotactic predators. Using observed kinematics of various types of jumps, we computed the imposed flow fields and associated energetics of jumps by means of computational fluid dynamics simulations by modeling the copepod as a self-propelled body. The computational fluid dynamics simulation was validated by particle image velocimetry data. The flow field generated by a repositioning jump quickly evolves into two counter-rotating viscous vortex rings that are near mirror image of one another, one in the wake and one around the body of the copepod; this near symmetrical flow may provide hydrodynamic camouflage because it contains no information about the position of the copepod prey within the flow structure. The flow field associated with an escape jump sequence also includes two dominant vortex structures: one leading wake vortex generated as a result of the first jump and one around the body, but between these two vortex structures is an elongated, long-lasting flow trail with flow velocity vectors pointing towards the copepod; such a flow field may inform the predator of the whereabouts of the escaping copepod prey. High Froude propulsion efficiency (0.94–0.98) was obtained for individual power stroke durations of all simulated jumps. This is unusual for small aquatic organisms but is caused by the rapidity and impulsiveness of the jump that allows only a low-cost viscous wake vortex to travel backwards.
Polarised skylight and the landmark panorama provide night-active bull ants with compass information during route following
Authors: Reid Samuel F. , Narendra Ajay , Hemmi Jan M. , Zeil Jochen
Published: January 2011

Navigating animals are known to use a number of celestial and terrestrial compass cues that allow them to determine and control their direction of travel. Which of the cues dominate appears to depend on their salience. Here we show that night-active bull ants attend to both the pattern of polarised skylight and the landmark panorama in their familiar habitat. When the two directional cues are in conflict, ants choose a compromise direction. However, landmark guidance appears to be the primary mechanism of navigation used by forager ants, with those cues in the direction of heading having the greatest influence on navigation. Different colonies respond to the removal of these cues to different degrees, depending on the directional information provided by the local landmark panorama. Interestingly, other parts of the surrounding panorama also influence foraging speed and accuracy, suggesting that they too play a role in navigation.
Poor flight performance in deep-diving cormorants
Authors: Watanabe Yuuki Y. , Takahashi Akinori , Sato Katsufumi , Viviant Morgane , Bost Charles-André
Published: January 2011

Aerial flight and breath-hold diving present conflicting morphological and physiological demands, and hence diving seabirds capable of flight are expected to face evolutionary trade-offs regarding locomotory performances. We tested whether Kerguelen shags Phalacrocorax verrucosus, which are remarkable divers, have poor flight capability using newly developed tags that recorded their flight air speed (the first direct measurement for wild birds) with propeller sensors, flight duration, GPS position and depth during foraging trips. Flight air speed (mean 12.7 m s–1) was close to the speed that minimizes power requirement, rather than energy expenditure per distance, when existing aerodynamic models were applied. Flights were short (mean 92 s), with a mean summed duration of only 24 min day–1. Shags sometimes stayed at the sea surface without diving between flights, even on the way back to the colony, and surface durations increased with the preceding flight durations; these observations suggest that shags rested after flights. Our results indicate that their flight performance is physiologically limited, presumably compromised by their great diving capability (max. depth 94 m, duration 306 s) through their morphological adaptations for diving, including large body mass (enabling a large oxygen store), small flight muscles (to allow for large leg muscles for underwater propulsion) and short wings (to decrease air volume in the feathers and hence buoyancy). The compromise between flight and diving, as well as the local bathymetry, shape the three-dimensional foraging range (<26 km horizontally, <94 m vertically) in this bottom-feeding cormorant.
The underwater photic environment of Cape Maclear, Lake Malawi: comparison between rock- and sand-bottom habitats and implications for cichlid fish vision
Authors: Sabbah Shai , Gray Suzanne M. , Boss Emmanuel S. , Fraser James M. , Zatha Richard , Hawryshyn Craig W.
Published: January 2011

Lake Malawi boasts the highest diversity of freshwater fishes in the world. Nearshore sites are categorized according to their bottom substrate, rock or sand, and these habitats host divergent assemblages of cichlid fishes. Sexual selection driven by mate choice in cichlids led to spectacular diversification in male nuptial coloration. This suggests that the spectral radiance contrast of fish, the main determinant of visibility under water, plays a crucial role in cichlid visual communication. This study provides the first detailed description of underwater irradiance, radiance and beam attenuation at selected sites representing two major habitats in Lake Malawi. These quantities are essential for estimating radiance contrast and, thus, the constraints imposed on fish body coloration. Irradiance spectra in the sand habitat were shifted to longer wavelengths compared with those in the rock habitat. Beam attenuation in the sand habitat was higher than in the rock habitat. The effects of water depth, bottom depth and proximity to the lake bottom on radiometric quantities are discussed. The radiance contrast of targets exhibiting diffused and spectrally uniform reflectance depended on habitat type in deep water but not in shallow water. In deep water, radiance contrast of such targets was maximal at long wavelengths in the sand habitat and at short wavelengths in the rock habitat. Thus, to achieve conspicuousness, color patterns of rock- and sand-dwelling cichlids would be restricted to short and long wavelengths, respectively. This study provides a useful platform for the examination of cichlid visual communication.
Deformation of Damaged Elastic-Brittle Isotropic Materials with a Fixed Concentration of Microdefects in a Complex Stress State
Authors: Babich D V , Bastun V N
Published: January 2011

The character of deformation of elastic—brittle isotropic materials weakened by flat microdefects in the form of circular or elliptic microcracks randomly dispersed over volume is studied in the complex stress state. It is assumed that concentration of the microcracks under loading remains constant. Equations of state for such materials are derived depending on the stress state mode and sign of applied stresses. The damaged material is simulated by a linear elastic isotropic medium under all-round compression or tension and under biaxial compression, by a linear elastic transversally isotropic medium under biaxial tension, and by a non-linear orthotropic medium under compression along one axis and tension along another axis. To determine compliance characteristics entering into the equations of state, the continual model of a cracked medium and a method based on the equivalence principle of deformation energy of this medium are used. A numerical example is presented.
Autofrettage and Shakedown Analysis of Strain-Hardening Cylinders under Thermo-Mechanical Loadings
Authors: Zheng X-T , Xuan F-Z
Published: January 2011

Autofrettage and shakedown analysis of power law strain-hardening cylinders subjected to thermo-mechanical loads were performed in the present study. The closed form solution of the limit thermal load of autofrettage and the optimum autofrettage pressure under plane strain and open-ended conditions are investigated theoretically and validated by the finite element method (FEM). In addition, the effect of autofrettage on the shakedown behaviour of thick cylinders subjected to a constant internal pressure and cyclic thermal loading is discussed. Results reveal that the limit thermal load depends on the thickness ratio and operating pressure and the optimum autofrettage pressure relies on the thickness ratio, operating pressure, strain-hardening exponent, as well as the thermal load. The proposed solution of the optimum autofrettage pressure agrees very well with the FEM result. The theoretical solution of the optimum autofrettage pressure decreases in plane strain and can be used to estimate the case of open-ended conditions with good accuracy. Furthermore, autofrettage has no effect on the shakedown behaviour due to the rapid relaxation of autofrettaged residual stress of structures after several load cycles.
Saint-Venant Torsion of Open-Section Members of Uniform Thickness
Authors: Hematiyan M R , Estakhrian E
Published: January 2011

An efficient analytical method for torsion analysis of open-section members of uniform thickness is presented. The conventional method based on the thin-walled theory for torsion analysis of bars can give good solutions only for members with small thickness and fillets of large radius. In the present method, a better approximation is employed, and much more accurate formulas are derived. The cross-section is considered to consist of some straight and curved (circular arc) segments. The Poisson equation of the torsion problem in terms of Prandtl's stress function is solved in each segment separately. By the present method, closed-form solutions for shear stress and torsional rigidity of members with open cross-section can be found. Some formulas for torsion analysis of tubes with a longitudinal slit and for members with angle and channel cross-section are derived. While these formulas are relatively simple, they give excellent results for thin- to moderately thick-walled members.
Dynamic Feasibility of Cooperative Systems under Communication Delay
Authors: Ashokkumar C R , Jeffcoat D E
Published: January 2011

In this article, the dynamic feasibility of a finite set of spatially distributed systems to engage in a formation is investigated. When system design capabilities such as state and input constraints are given, formation options may be limited, due to initial condition errors resulting from modelling uncertainties, exogenous inputs, etc. These underlying factors in turn affect the feasibility of interconnection, which are the design variables used to synthesize a formation. In a leader-follower framework, it is shown that, in some cases, the communication delay has a favourable effect on the feasibility of interconnections, i.e. a communication delay can convert an infeasible interconnection into a feasible one and increase the formation options. A mobile robot example is provided for illustration.
Dubins Path Planning of Multiple Unmanned Airborne Vehicles for Communication Relay
Authors: Kim S , Silson P , Tsourdos A , Shanmugavel M
Published: January 2011

This article investigates the path planning strategy of a swarm of unmanned airborne vehicles (UAVs) with the aim of guaranteeing the communication relay between a ground control station and a friendly fleet. A decision-making algorithm mainly relies on waypoint generations and path planning based on Dubins theory and deals with dynamic and strategic constraints such as maximum speed, minimum curvature radius, and no fly zones arising from the mission operative scenario. The example simulations concerning a baseline scenario with a swarm of three UAVs are done to verify the feasibility of the proposed path planning algorithm.
Telerehabilitation in stroke care – a systematic review
Authors: Johansson Tim , Wild Claudia
Published: January 2011

We conducted a systematic review of telerehabilitation interventions in stroke care. The following databases were searched: Medline, Embase, DARE-NHSEED-HTA (INAHTA) and the Cochrane Library. Nine studies, all published after 2000, were included in the review. A wide variety of telemedicine interventions in post-stroke rehabilitation care was identified. Four studies had been carried out in the USA, two in the Netherlands, two in Italy and one in China. There were four randomized controlled trials and one qualitative analysis. Four studies used an observational study design/case series. Home-based telerehabilitation interventions showed promising results in improving the health of stroke patients and in supporting caregivers. Telemedicine systems based on a virtual environment for upper extremity exercise can improve the physical health of stroke patients. Health professionals and participants reported high levels of satisfaction and acceptance of telerehabilitation interventions. There was no evidence regarding the effects on resource utilization or cost-effectiveness. Most studies showed promising results, although overall, the quality of the evidence on telerehabilitation in post-stroke care was low.
Delivery of Internet-based cancer genetic counselling services to patients' homes: a feasibility study
Authors: Meropol Neal J , Daly Mary B , Vig Hetal S , Manion Frank J , Manne Sharon L , Mazar Carla , Murphy Camara , Solarino Nicholas , Zubarev Vadim
Published: January 2011

We examined the feasibility of home videoconferencing for providing cancer genetic education and risk information to people at risk. Adults with possible hereditary colon or breast and ovarian cancer syndromes were offered Internet-based counselling. Participants were sent web cameras and software to install on their home PCs. They watched a prerecorded educational video and then took part in a live counselling session with a genetic counsellor. A total of 31 participants took part in Internet counselling sessions. Satisfaction with counselling was high in all domains studied, including technical (mean 4.3 on a 1–5 scale), education (mean 4.7), communication (mean 4.8), psychosocial (mean 4.1) and overall (mean 4.2). Qualitative data identified technical aspects that could be improved. All participants reported that they would recommend Internet-based counselling to others. Internet-based genetic counselling is feasible and associated with a high level of satisfaction among participants.
A pilot study of the Tele-Airway Management System in a hospital emergency department
Authors: Cho Junho , Chung Hyun Soo , Choa Minhong , Yoo Sun K , Kim Jungchae
Published: January 2011

We developed a telemedicine system for remote guidance of emergency airway management called the Tele-Airway Management System (TAMS). In a pilot study we examined the usefulness of the TAMS for intubations of actual patients in a hospital emergency department. Twenty-five patients were allocated randomly either to a TAMS group or to an on-scene directed (OSD) group. A total of 12 were intubated using the TAMS. The mean time to intubation (TAMS 62 s vs. OSD 56 s) and the success rate was not different between the two groups ( P > 0.05). There were two oesophageal intubations in the TAMS group and four in the OSD group, but this was not significantly different ( P = 0.36). There were no mechanical or technical errors such as disconnection during use of the TAMS. The pilot study demonstrated the feasibility of the TAMS as an alternative to OSD. However, a larger study will be required to determine non-superiority or equivalence.
Sensitivity and specificity of telemedicine-based long-term pulse-oximetry in comparison with cardiorespiratory polygraphy and polysomnography in patients with obstructive sleep apnoea syndrome
Authors: Böhning Nikolaus , Zucchini Walter , Hörstmeier Oliver , Böhning Wilfried , Fietze Ingo
Published: January 2011

We investigated the feasibility of night-time pulse-oximetry telemedicine. We compared polysomnography (PSG) as the gold standard with simultaneously recorded pulse-oximetry from a wrist pulse-oximeter. The results were evaluated by a sleep specialist and compared with outpatient polygraphy. A total of 135 consecutive patients (mean age 55 years, mean body mass index 31.6 kg/m2) were studied. Patients with minor, moderate and severe PSG findings were grouped together and compared to those without PSG findings; the resulting sensitivity was 1 and specificity 0.35. In addition, patients with and without minor PSG findings were grouped together and compared to those with moderate and severe PSG findings; the resulting sensitivity was 0.66 and the specificity was 0.98. The receiver operating characteristic (ROC) of telemedically-evaluated oximetry was superior to that of outpatient polygraphy. In contrast, the automatic assessment of severity based on the Oxygen Desaturation Index was unsatisfactory. For patients suspected of sleep related breathing disorders (SRBD), telemedically-evaluated pulse-oximetry is able to identify those who should be referred to a sleep laboratory for definitive diagnosis and treatment. The technique appears to be suitable for first screening in all patients at risk for SRBD.
A pilot teleconsultation network for retinal diseases in ophthalmology
Authors: Azzolini Claudio
Published: January 2011

A store-and-forward teleconsultation network was developed as a web application in order to provide second opinions on retinal diseases. The system provided automatic notification messages to the referring doctor and the consulted ophthalmologist by mobile phone message (SMS) and email. Images in the electronic medical record (EMR) could be examined in detail using special magnification software. Of the 19 ophthalmologists who agreed to participate, 17 used the teleconsultation network during the pilot trial (89%). During the four-week study period, a total of 52 EMRs containing 82 images were uploaded by the participating ophthalmologists. In 46 cases (89%), a second opinion was provided by the consulted ophthalmologist. Thirty-three of the cases (72%) were related to macular diseases and anti-VEGF (vascular endothelial growth factor) ophthalmology drugs. At the end of the study period, 18 of the participating ophthalmologists evaluated the cases, using a three-point score (poor, good, very good) for Access, Acceptability, Image Quality and Medical Efficacy. Most cases were rated as very good or good for all four variables. Successful use of the network in future will depend on various technical, policy and human factors. The latter is particularly important and appropriate motivations need to be found in order to promote teleconsultations.
Patients' experiences of telerehabilitation at home after shoulder joint replacement
Authors: Eriksson Lisbeth , Lindström Britta , Ekenberg Lilly
Published: January 2011

We investigated the experience of ten patients who received video-based physiotherapy at home for two months after a shoulder joint replacement. Videoconferencing took place via the patient's home broadband connection at a bandwidth of 256–768 kbit/s. Qualitative interviews were carried out, transcribed and analysed. Through qualitative content analysis six categories were identified: (1) a different reinforced communication; (2) pain-free exercising as an effective routine; (3) from a dependent patient to a strengthened person at home; (4) closeness at a distance; (5) facilitated daily living; and (6) continuous physiotherapy chain. The access to bodily knowledge, continuity, collaboration and being at home were all aspects that contributed to the patients' recovery. The patients described experiences of safety, and strengthening during their daily exercise routine at home. The frequent interplay with the patient during telerehabilitation made it possible for the physiotherapist to make an individual judgement about each patient; this could be one reason for the positive findings. Home video-based physiotherapy may be useful in other kinds of physiotherapy.
A review of the use of mobile phone text messaging in clinical and healthy behaviour interventions
Authors: Wei Jin , Hollin Ilene , Kachnowski Stan
Published: January 2011

We reviewed the literature on the use of text messaging for clinical and healthy behaviour interventions. Electronic databases were searched in December 2009 using keywords related to text messaging and health interventions. The final review included 24 articles. Of those, seven covered medication adherence, eight discussed clinical management and nine reported on health-related behaviour modification. Sixteen were randomized controlled trials (RCT), five were non-controlled pre-post comparison studies and three were feasibility pilots not reporting a behavioural outcome. The frequency of messaging ranged from multiple messages daily to one message per month. Among the 16 RCTs, 10 reported significant improvement with interventions and six reported differences suggesting positive trends. Text messaging received good acceptance and showed early efficacy in most studies. However, the evidence base is compromised by methodological limitations and is not yet conclusive.
The Impact of Carbon Capture and Storage on Coal Resource Depletion
Authors: Owens Edward H , Chapman Samuel , Allan Paul
Published: January 2011

Carbon Capture and Storage is being actively developed for deployment in fossil fuel power stations in an attempt to reduce future emissions of CO2 due to concerns about climate change. The deployment of this technology will cause an inevitable reduction in the overall efficiency of any electricity generation plant leading to an increase in demand for the fossil fuels used to power the generation process. This paper estimates the average reduction in generation efficiency caused by the imposition of Carbon Capture and Storage and considers its effects upon the depletion rate of global coal reserves. Future production of coal is modelled using a symmetrical production curve. The results suggest that the widespread adoption of Carbon Capture and Storage may result in the exhaustion of coal reserves several decades in advance of when this may happen if CCS is not deployed.
Environmental and Health Implications of Fuel Substitution for Cooking Energy in Nigeria's Household Energy Mix
Authors: Momodu Abiodun S. , Akinbami John-Felix K. , Akinwunmi Isaac O.
Published: January 2011

This paper is concerned with effects that are considered undesirable for women and children in household energy utilization. In Nigeria, household energy utilization is significant where it contributes 53% to total energy consumption with bio-energy inclusive. 85% of bio-energy contribution to final energy consumption goes to service energy needs. Technology mix for cooking in households includes firewood stoves (41%), charcoal stoves (1%), kerosene stoves (53%), Liquefied Petroleum Gas (LPG) stoves (4.5%) and electric burners (0.5%). Literature review, survey and application of simulation technique were employed as methodology. For the simulation technique, factors considered include impact of technological interventions as well as structural shifts among economic sectors and sub-sectors. With technology intervention, the simulated results indicate that savings of 1.5 billion kg Ceq, and the avoided cost of about $0.11 million/tonne Ceq, can be achieved. Economic benefits may include reduced health-related expenditure, time savings from shorter time spent on fuel collection and cooking, and environmental impacts at local levels.
External Forces Acting on the Earth's Climate: An Approach to Understanding the Complexity of Climate Change
Authors: Kikuchi Ryunosuke
Published: January 2011

The Intergovernmental Panel on Climate Change defines lifetime for CO2 as the time required for the atmosphere to adjust to a future equilibrium state, and it gives a wide range of 5–200 years; however, a number of published data show a short lifetime of 5–15 years. This implies that anthropogenic emissions of CO2 are sequestrated more easily than expected, suggesting it would be beneficial to look at other climate factors when making long-term predictions. Considering the magnitude and the time length (cycle), climate change can be interpreted as the result of the complex coupling of astronomic forces (e.g. the Earth's orbit and cosmic-ray flux) as well as terrestrial forces. Regarding the Earth's climate as a complex (nonlinear) system, it is necessary for the climate research community and policy makers to distinguish between variations caused by anthropogenic and natural occurrences, and the problem of how to do so arises.
Uncertainty in the Global Average Surface Air Temperature Index: A Representative Lower Limit
Authors: Frank Patrick
Published: January 2011

Sensor measurement uncertainty has never been fully considered in prior appraisals of global average surface air temperature. The estimated average ±0.2 C station error has been incorrectly assessed as random, and the systematic error from uncontrolled variables has been invariably neglected. The systematic errors in measurements from three ideally sited and maintained temperature sensors are calculated herein. Combined with the ±0.2 C average station error, a representative lower-limit uncertainty of ±0.46 C was found for any global annual surface air temperature anomaly. This ±0.46 C reveals that the global surface air temperature anomaly trend from 1880 through 2000 is statistically indistinguishable from 0 C, and represents a lower limit of calibration uncertainty for climate models and for any prospective physically justifiable proxy reconstruction of paleo-temperature. The rate and magnitude of 20th century warming are thus unknowable, and suggestions of an unprecedented trend in 20th century global air temperature are unsustainable.
CFD Modeling of Electrostatic Forces in Gas-Solid Fluidized Beds
Authors: Rokkam Ram G. , Fox Rodney O. , Muhle Michael E.
Published: January 2011

Electrostatic charges in gas-solid fluidized beds are known to influence the bed dynamics, bubble shape and size, particle agglomeration, segregation and entrainment. In practice, accumulation of electrostatic charges in fluidized beds can lead to operational issues. The present work focuses on the modeling of electrostatics in gas-solid fluidized beds. The particles are assumed to carry a prescribed size-dependent charge, and charge generation and dissipation are not modeled. To consider the effects of bi-polar charging the polarity of the charge carried by fine particles is taken opposite to that of coarse particles. The magnitude of particle charges is approximated to realistic charges reported in the literature. The principal objective is to develop a multi-fluid Euler-Euler model that can describe electrostatic forces on charged particles in gas-solid fluidized beds. The multi-fluid model is solved in a commercial CFD code (ANSYS Fluent 6.3) and uses the kinetic theory of granular flow for calculating solids pressure and viscosity. The electric field, generated by the presence of charged particles, is solved for at every time step in the time-dependent simulation. The electrostatic forces, proportional to the gradient of the electric field and the particle charge, lead to charge-dependent forces on the particles. The electrostatic model has been developed and applied to a two-dimensional fluidized bed. Charge-dependent segregation is found to vary with the polarity and magnitude of the charge on the solid phase as a function of the particle size.
Unsteady Particle Deposition in a Human Nasal Cavity during Inhalation
Authors: Se Camby M.K. , Inthavong Kiao , Tu Jiyuan
Published: January 2011

The present study investigates the deposition efficiency during the unsteady inhalation cycle by using Computational Fluid Dynamics (CFD). The unsteady inhalation profile was applied at the outlet of nasopharynx, which had a maximum flow rate of 40.3L/min which corresponds to an equivalent steady inhalation tidal volume flow rate of 24.6L/min. Aerodynamic particle sizes of 5μm and 20μm were studied in order to reflect contrasting Stokes numbered particle behaviour. Two particle deposition efficiencies in the nasal cavity versus time are presented. In general, the deposition of 5μm particles was much less than 20μm particles. The first 0.2 second of the inhalation cycle was found to be significant to the particle transport, since the majority of particles were deposited during this period (i.e. its residence time). Comparisons were also made with its equivalent steady inhalation flow rate which found that the unsteady inhalation produced lower deposition efficiency for both particle sizes.
A 3D CFD Modelling Study of a Diesel Oil Evaporation Device Operating in the Stabilized Cool Flame Regime
Authors: Kolaitis Dionysios I. , Founti Maria A.
Published: January 2011

Diesel fuel is used in a variety of technological applications due to its high energy density and ease of distribution and storage. Motivated by the need to use novel fuel utilization techniques, such as porous burners and fuel cells, which have to be fed with a gaseous fuel, a Diesel fuel evaporation device, operating in the “Stabilized Cool Flame” (SCF) regime, is numerically investigated. In this device, a thermo-chemically stable low-temperature oxidative environment is developed, which produces a well-mixed, heated air-fuel vapour gaseous mixture that can be subsequently fed either to premixed combustion systems or fuel reformer devices for fuel cell applications. In this work, the ANSYS CFX 11.0 CFD code is used to simulate the three-dimensional, turbulent, two-phase, multi-component and reacting flow-field, developed in a SCF evaporation device. An innovative modelling approach, based on the fitting parameter concept, has been developed in order to simulate cool flame reactions. The model, based on physico-chemical reasoning coupled with information from available experimental data, is implemented in the CFD code and is validated by comparing numerical predictions to experimental data obtained from an atmospheric pressure, recirculating flow SCF device. Numerical predictions are compared with temperature measurements, achieving satisfactory levels of agreement. The developed numerical tool can effectively support the theoretical study of the physical and chemical phenomena emerging in practical devices of liquid fuel spray evaporation in a SCF environment, as well as the design optimisation process of such innovative devices.
Modelling the Multiphase Flow in Dense Medium Cyclones
Authors: Chu Kaiwei , Wang Bo , Yu Aibing , Vince Andrew
Published: January 2011

Dense medium cyclone (DMC) is widely used in mineral industry to separate solids by density. It is simple in design but the flow pattern within it is complex due to the size and density distributions of the feed and process medium solids, and the turbulent vortex formed. Recently, the so-called combined computational fluid dynamics (CFD) and discrete element method (DEM) (CFD-DEM) was extended from two-phase flow to model the flow in DMCs at the University of New South Wales (UNSW). In the CFD-DEM model, the flow of coal particles is modelled by DEM and that of medium flow by CFD, allowing consideration of medium-coal mutual interaction and particle-particle collisions. In the DEM model, Newton's laws of motion are applied to individual particles, and in the CFD model the local-averaged Navier-Stokes equations combined with the volume of fluid (VOF) and mixture multiphase flow models are solved. The application to the DMC studies requires intensive computational effort. Therefore, various simplified versions have been proposed, corresponding to the approaches such as Lagrangian particle tracking (LPT) method where dilute phase flow is assumed so that the interaction between particles can be ignored, one-way coupling where the effect of particle flow on fluid flow is ignored, and the use of the concept of parcel particles whose properties are empirically determined. In this paper, the previous works on the modelling of DMCs at UNSW are summarized and the features and applicability of the models used are discussed.
Rational design of artificial riboswitches based on ligand-dependent modulation of internal ribosome entry in wheat germ extract and their applications as label-free biosensors
Authors: Ogawa Atsushi
Published: January 2011

Riboswitches are RNA elements in mRNA that control gene expression in cis in response to their specific ligands. Because artificial riboswitches make it possible to regulate any gene with an arbitrary molecule, they are expected to function as biosensors, in which the output is easily detectable protein expression. I report herein a fully rational design strategy for artificially constructing novel riboswitches that work in a eukaryotic cell-free translation system (wheat germ extract). In these riboswitches, translation mediated by an internal ribosome entry site (IRES) is promoted only in the presence of a specific ligand (ON), while it is inhibited in the absence of the ligand (OFF). The first rationally designed riboswitch, which is regulated by theophylline, showed a high switching efficiency and dependency on theophylline. In addition, based on the design of the theophylline-dependent riboswitch, other three kinds of riboswitches controlled by FMN, tetracycline, and sulforhodamine B, were constructed only by calculating the ΔG value of one stem–loop structure. The rational design strategy described herein is therefore useful for easily producing various ligand-dependent riboswitches, which are available as biosensors for detecting their ligands.
Pseudo–Pelger-Huët Anomaly Induced by Medications
Authors: Wang Endi , Boswell Elizabeth , Siddiqi Imran , Lu Chuanyi Mark , Sebastian Siby , Rehder Catherine , Huang Qin
Published: January 2011

Pseudo–Pelger-Huët anomaly (PPHA) has been documented in association with transplant medications and other drugs. This iatrogenic neutrophilic dysplasia is reversible with cessation or adjustment of medications but is frequently confused with myelodysplastic syndrome (MDS) based on the conventional concept that PPHA is a marker for dysplasia. We investigated the clinicopathologic features in iatrogenic PPHA and compared them with MDS-related PPHA. The 13 cases studied included 5 bone marrow/stem cell transplantations, 3 solid organ transplantations, 1 autoimmune disease, 3 chronic lymphocytic leukemias, and 1 breast carcinoma. For 12 cases, there was follow-up evaluation, and all demonstrated at least transient normalization of neutrophilic segmentation. All 9 cases of MDS demonstrated at least 2 of the following pathologic abnormalities on bone marrow biopsy: hypercellularity (8/9), morphologic dysplasia (8/9), clonal cytogenetic abnormality (7/9), and increased blasts (3/9), whereas these abnormalities were typically absent in iatrogenic PPHA. Iatrogenic PPHA displayed a higher proportion of circulating PPHA cells than in MDS (mean, 47.4%; SD, 31.6% vs mean, 12.3%; SD, 9.8; P < .01). A diagnostic algorithm is proposed in which isolated PPHA is indicative of transient or benign PPHA unless proven otherwise.
Use of Genotype Frequencies in Medicated Groups to Investigate Prescribing Practice: APOE and Statins as a Proof of Principle
Authors: Davies Neil M , Windmeijer Frank , Martin Richard M , Abdollahi Mohammad R , Smith George Davey , Lawlor Debbie A , Ebrahim Shah , Day Ian NM
Published: January 2011

BACKGROUND

If treatments are used to modify a trait, then patients with high-risk genotypes for the trait should be found at higher frequency in treatment groups than in the general population. The frequency ratio of high- to low-risk genotypes treated should reflect the mean threshold above which the treatment is given in the population. As an example, we hypothesized that because APOE (apolipoprotein E) alleles affect the LDL cholesterol (LDLc) concentration, APOE genotype frequencies in statin takers should act as a proxy for the prevailing treatment threshold of LDLc.

METHODS

We used LDLc, statin usage, and APOE genotype data from the British Women's Heart and Health Study (n = 2289; age, 60–79 years) and calculated the genotype ratio treatment index (GRTI) by dividing the proportion of ε3/ε2 or ε3/ε4 participants prescribed a statin by the proportion of ε3/ε3 participants prescribed a statin, both overall and according to socioeconomic class, geographic region, and coronary heart disease (CHD) status. Genotype-specific LDLc distributions were used to calculate the mean LDLc treatment threshold.

RESULTS

For genotype ε3/ε2, the GRTI was 0.52 (95% CI, 0.30–0.87) for statin takers overall, 0.22 (95% CI, 0.00–0.56) for those without CHD, and 0.69 (95% CI, 0.31–1.18) for those with CHD. The GRTIs for those without and with CHD backcalculate to LDLc thresholds of 5.65 mmol/L (95% CI, 5.50–5.82 mmol/L) and 4.39 mmol/L (95% CI, 4.21–4.59 mmol/L), respectively. Scotland and North England showed dissimilar GRTIs, which backcalculated to LDLc thresholds of 5.06 mmol/L (95% CI, 4.83–5.28 mmol/L) and 5.44 mmol/L (95% CI, 5.19–5.69 mmol/L), respectively, for all women.

CONCLUSIONS

The findings illustrate how genotype frequencies can be a proxy for treatment thresholds used in clinical practice. Genome-wide studies have identified >500 disease-relevant polymorphisms. GRTIs from cost-efficient genotyping, in combination with phenotypic data, may have wide potential in health services research.
Fashioned identity and the unreliable image
Authors: Finkelstein Joanne
Published: January 2011

High street fashion is an important industry in economic as well as aesthetic and cultural terms. Fashions not only provide a social language based on easily recognized, high-circulating items but they also generate massive wealth. These visual icons and images globalize human experience
to a significant extent while, at the same time, remaining problematic to read. For example, how well-recognized and globally accepted are the meanings around images of a full red-lipsticked mouth, an unbuttoned pristine business shirt, or spiked multi-coloured hair The history of the visual
suggests that every image has multiple readings; there is no essence to the image, no limits to its commentary, no reassuring boundaries restricting its suggestions. The image is ubiquitous, problematic and enduringly pleasurable, even as its meanings are tantalizingly concealed. A fascinating
example is explored in this article of the ethno-methodological folly of the late 1960s, when a hormone pill-popping young man convinced a myopic medical team to undertake the desired surgical reassignment of his gender. The con was affected on the basis of a skilful and smooth gender-bending
performance that rested on the persuasiveness of the unreliable image.
Digital identity management: Old wine in new bottles
Authors: Solomon Michael R
Published: January 2011

Fashion and identity are inextricably linked. Consumers throughout the ages have strategically deployed apparel and other self-expressive products to signal real and aspirational personas and to pursue hedonic exploration and fantasy. Often these transformations are entrusted to aesthetic
professionals such as clothing designers, cosmeticians and photographers.

Today, new technological platforms enable even the amateur to create a myriad of identities as she navigates the evolving virtual environment some call The Metaverse. But this is by no means a one-way journey;
in some cases cyber-spatial experiences also impact on real-world identity. This article explores the theoretical and practical ramifications of digital identity management as consumers in the form of avatar representations make the passage from the physical world to the virtual,
and back again.
Russian immigrant women and the negotiation of social class and feminine identity through fashion
Authors: Korotchenko Alexandra , Clarke Laura Hurd
Published: January 2011

Building on the growing body of literature that examines the consumption of fashion and the construction of identity through clothing, this article uses data from in-depth interviews with ten women aged 52 to 75 to examine Russian immigrant women's experiences of fashion. Specifically,
we explore the ways in which Russian immigrant women's clothing choices and attitudes towards fashion are framed by their socialization within Russian cultural values (which privilege feminine appearance), their assimilation into Canadian culture, their resistance to Canadian views of beauty
and femininity, and their feelings about their aging bodies. Our findings reveal that Russian immigrant women's doing of gender, age, social class, and immigrant status are shaped by culturally and historically situated conceptions of femininity as well as by decisions to either assimilate
into North American culture or to other the self as distinctively Russian.
Revisioning the kimono
Authors: Cliffe Sheila
Published: January 2011

Whilst the kimonoed woman is an unchanging stereotype of Japanese beauty, this article suggests that due to the interaction of kimono with the processes of globalization (technological and in terms of communication), the kimono continues to metamorphose to meet the needs of its fashionable,
urban, contemporary wearers.
Coming out of the cabinet: Fashioning the closet with Sweden's most famous diplomat
Authors: Gindt Dirk
Published: January 2011

This article offers a critical analysis of the media discourse surrounding the Swedish diplomat Sverker strm's coming out as a gay man at the age of 87. Particular interest is devoted to his striking fashion choice of wearing a pair of oddly coloured socks, which highlighted his contradictory
masculinity as well as the many inherent paradoxes of the closet. strm's red and green socks functioned as a means to express forbidden desires, to oppose normative expectations in a playful way and to grant the gay subject a presence in a world that is still very much structured by the logics
of the closet. Moreover, his contradictory body language, coupled with his repeated affirmations that his coming out was a private issue, revealed a divided masculinity that was ideologically dependent on a pre-feminist understanding of gender and sexuality as private, that is to say non-political.
The article argues that there was strong evidence to suggest that his coming out was in fact a tactical move in a political game, a move aimed to denounce and ridicule the Swedish Security Police (SPO), who, after decades of surveillance, refused to grant the diplomat access to its classified
files on him.
Comparing 3D content creation interfaces in two virtual worlds: World of Warcraft and Second Life
Authors: McArthur Victoria , Teather Robert J , Stuerzlinger Wolfgang
Published: January 2011

In this article we compare the content creation systems of two popular virtual worlds:World of WarcraftandSecond Life.We then discuss recommendations for three-dimensional (3D) content creation systems based on current trends in 3D user interface research. We hypothesize that by designing 3D content creation systems that follow these recommendations, virtual-world economies based on custom content creation (e.g.,Second Life) may be transformed, as more people will be able to create and modify content.
Reviews
Authors: Ruch Adam , Farman Jason
Published: January 2011

Assassin's Creed 2: A Renaissance
Assassin's Creed 2, Ubisoft (2010), Montreal, Quebec (Canada): Ubisoft, $39.99 (USD)

The Transformation of Everyday Life Through Pervasive Play
Pervasive Games: Theory and Design, Markus Montola, Jaakko Stenros
and Annika Waern (2009), New York: Morgan Kaufmann, 336pp., ISBN: 978-0-12-374853-9, Paperback, $49.95 (USD)
Nucleolar Disruption in Dopaminergic Neurons Leads to Oxidative Damage and Parkinsonism through Repression of Mammalian Target of Rapamycin Signaling
Authors: Rieker Claus , Engblom David , Kreiner Grzegorz , Domanskyi Andrii , Schober Andreas , Stotz Stefanie , Neumann Manuela , Yuan Xuejun , Grummt Ingrid , Schütz Günther , Parlato Rosanna
Published: January 2011

The nucleolus represents an essential stress sensor for the cell. However, the molecular consequences of nucleolar damage and their possible link with neurodegenerative diseases remain to be elucidated. Here, we show that nucleolar damage is present in both genders in Parkinson's disease (PD) and in the pharmacological PD model induced by the neurotoxin 1,2,3,6-tetrahydro-1-methyl-4-phenylpyridine hydrochloride (MPTP). Mouse mutants with nucleolar disruption restricted to dopaminergic (DA) neurons show phenotypic alterations that resemble PD, such as progressive and differential loss of DA neurons and locomotor abnormalities. At the molecular level, nucleolar disruption results in increased p53 levels and downregulation of mammalian target of rapamycin (mTOR) activity, leading to mitochondrial dysfunction and increased oxidative stress, similar to PD. In turn, increased oxidative stress induced by MPTP causes mTOR and ribosomal RNA synthesis inhibition. Collectively, these observations suggest that the interplay between nucleolar dysfunction and increased oxidative stress, involving p53 and mTOR signaling, may constitute a destructive axis in experimental and sporadic PD.