bluuebunny/crossref_metadata_2025 huggingface dataset:
Briksdalsbreen in western Norway: AD 1900-2004 frontal fluctuations as a combined effect of variations in winter precipitation and summer temperature
Authors: Nesje Atle
Published: November 2005

Mountain glaciers and ice caps are sensitive to changes in regional and global climate. Temporal glacier variations, manifested in change of volume, area and length, provide some of the clearest signals of climate change in nature. Therefore, glaciers are considered key indicators for the detection of global warming. Except for a few glaciers in western Scandinavia, glaciers in Europe are in retreat, following the global trend. Maritime (coastal) glaciers in western Norway experienced positive mass balance and large frontal advance during the 1990s because of increased winter accumulation. In contrast, after 1996, and especially since 2001, these glaciers have experienced strong negative mass balance and, as a result of short (< 5 years) response time, frontal retreat. Briksdalsbreen, a short and steep outlet glacier from Jostedalsbreen (the largest glacier on mainland Europe), retreated 230 m between 1996/97 and 2004, with a maximum annual retreat of 130 m in 2003/2004. This is the largest annual retreat recorded since the start of the frontal measurements in 1900. This study demonstrates that glacier fluctuations are not only a response to ablation-season temperature variations, but are also highly dependent on accumulation-season precipitation. The records of glacier-front variations and the climate variability over the last-100 years in western Norway may be regarded as a ‘modern analogue’ for other Holocene events and are useful in evaluating the likelihood that similar climate and glacier variability will occur in the future.
Pattern of stingray injuries reported to Texas poison centers from 1998 to 2004
Authors: Forrester Mathias B.
Published: November 2005

This study examined the relationship between selected factors and all human exposures involving stingray injuries reported to Texas poison centers. Cases were obtained retrospectively from calls to poison centers in Texas and included all reported human exposures involving stingray injuries from 1998 to 2004. The distribution of cases was determined for a variety of demographic and clinical parameters. A total of 153 cases were identified. The reported stingray injury penetrance increased during the 7-year period. Of the cases with a known patient age, 2% were < 6 years, 25% were 6-19 years. The stingray injuries occurred in public areas in 54% of the cases. In 61% of cases, the management site was reported not to be a health care facility. Of the cases with a known clinical outcome, none involved no effects and 53% involved minor effects. The highest proportion of stingray injuries occurred during the summer months, particularly August. In 60% of the cases, the calls originated from counties along the coast. This information can be used to identify those portions of the population most in need of education regarding the prevention and treatment of stingray injuries.
Increase in thyroid follicular cell tumors in nelfinavir-treated rats observed in a 2-year carcinogenicity study is consistent with a rat-specific mechanism of thyroid neoplasia
Authors: Burns-Naas L A , Zorbas M , Jessen B , Evering W , Stevens G , Ivett J L , Ryan T E , Cook J C , Capen C C , Chen M , Furman G , Theiss J C , Webber S , Wu E , Shetty B , Gasser R , McClain R M
Published: November 2005

The carcinogenic potential of nelfinavir mesylate (nelfinavir) was evaluated in a 2-year oral (gavage) study on Sprague-Dawley rats at dose levels of 0 (control), 0 (vehicle control), 100, 300 and 1000 mg/kg per day. At the end of the treatment, increased incidences of thyroid follicular cell hyperplasia and neoplasms were observed at 300 (males) and 1000 mg/kg per day (both sexes). There were no other treatment-related effects and no tumors at other sites. Results from previous studies indicated a number of effects in the liver and thyroid, as well as metabolic profiles that suggested nelfinavir might cause thyroid hyperplasia/neoplasia secondary to hormone imbalance by altering thyroid hormone disposition. To investigate this hypothesis, the effects of nelfinavir on gene expression in rat hepatocytes and liver slices (in vitro), thyroxine plasma clearance, and thyroid gland function were evaluated. Compared to controls, gene expression analyses demonstrated an increased expression of glucuronyltransferase (UDPGT) and CYP450 3A1 in nelfinavir-treated rat hepatocytes and liver slices. In rats treated with nelfinavir (1000 mg/kg per day) for 4 weeks, liver weights and centrilobular hepatocellular hypertrophy were increased and minimal to mild diffuse thyroid follicular cell hypertrophy and follicular cell hyperplasia were evident in the thyroid gland. Thyroid-stimulating hormone (TSH) levels were significantly increased (three-fold), while tri-iodothyronine (T3)/tetraiodothyronine (T4) and reverse T3(rT3) levels were unchanged, indicating that a compensated state to maintain homeostasis of T3/T4 had been achieved. Plasma 125I-thyroxine clearance was increased and the plasma thyroxine AUC0 48 was decreased (24%) compared to control. In conclusion, these data indicate that thyroid neoplasms observed in the nelfinavir-treated rats were secondary to thyroid hormone imbalance. Increased thyroxine clearance contributes to the effects of nelfinavir on thyroid gland function and is probably a result of UDPGT induction that leads to elevated TSH levels in the rat and eventual thyroid neoplasia. These results are consistent with a well-recognized rat-specific mechanism for thyroid neoplasms.
A retrospective study of mushroom poisoning in Iran
Authors: Pajoumand A , Shadnia S , Efricheh H , Mandegary A , Hassanian-Moghadam H , Abdollahi M
Published: November 2005

The objective of this study was to describe the pattern of mushroom poisoning in adults admitted to the Loghman Hakim Hospital Poison Center from 1992 to 2002. All patients ≥ 12 years of age were included in the study. The frequency of mushroom poisoning with respect to age, sex, season, reason, place of residence, latent phase, clinical and laboratory findings, treatment, and outcome of patients was investigated. Of the 72 421 poisoning cases admitted to Loghman-Hakim Hospital Poison Center from 1992 to 2002, only 37 were poisoned by consumption of toxic mushrooms. As some of the patients' files were incomplete, only 25 files were included in the study. Of this number, 68% were male. The patients' age ranged between 12 and 65 years, with a mean of 31 years of age. All cases were accidental and mostly from Tehran (36%) and the northern provinces (rainy woodlands) of Iran (32%). Autumn was the most common season for poisoning with a frequency of 80%. The latent phase of poisonings was between 0.5 and 12 hours. The most frequently reported symptoms were vomiting (84%), nausea (60%), abdominal pain (60%) and diarrhea (40%). Jaundice was observed in 44% of cases, with a 50% rate of hepatic encephalopathy. A total of 66% of patients were discharged and the duration range of hospitalization was 1-12 days.

In conclusion, people should be more informed of the dangers posed by wild mushrooms. Training of physicians and nurses in the accurate diagnosis and management of patients poisoned with poisonous mushrooms would improve the rate of survival.
Tissue levels of cadmium and trace elements in patients with myoma and uterine cancer
Authors: Nasiadek M , Krawczyk T , Sapota A
Published: November 2005

The aim of this study was to investigate the cadmium (Cd), copper (Cu), zinc (Zn), iron (Fe), magnesium (Mg) and calcium (Ca) concentrations in uterine cancer and uterine myoma. Tissue levels of six elements in 15 uterine cancers and 28 uterine myomas were measured by atomic absorption spectrometry. The samples were collected from women aged 32-79 (uterine myomas, uterine cancer and non-lesion uterine tissues from the same women). The results showed that the tissue Cd concentration was significantly lower in myoma than in non-lesion tissue. In uterine cancer, however, it was statistically significant, but only slightly lower than controls (the non-lesion uterine tissue). In the investigated tissues, the correlation between Cd concentration and age was found, but no effect of menopausal status or smoking habits on Cd level was detected. In uterine cancer tissue, a significant increase in Ca concentration and an insignificant increase in Mg level was observed when compared to normal uterine tissue. In uterine myoma, a significant increase of Mg and Mg/Ca ratio, as well as a decrease in Fe concentration were found. Statistical analysis showed no correlation between smoking habits, age, menopausal status and concentration of Cu, Zn, Fe, Mg and Ca trace metals in myoma or cancer tissue.
Effect of potassium dichromate on renal brush border membrane enzymes and phosphate transport in rats
Authors: Fatima S , Arivarasu N A , Banday A A , Yusufi A N K , Mahmood R
Published: November 2005

Chromium is widely used in industry but exposure to chromium compounds in the workplace can result in nephrotoxicity. Various nephrotoxicants affect the brush border membrane (BBM) lining the epithelial cells of the proximal tubule, but there have been no studies regarding the effect of potassium dichromate (K2Cr2O7), a hexava-lent chromium compound, on renal BBM. In the present work, the effect of administering a single intraperitoneal dose (15 mg/kg body weight) of K2Cr2O7 on rat renal BBM enzymes and inorganic phosphate (Pi) transport was studied. The animals were administered normal saline (control) or K2Cr2O7 and sacrificed 1, 2, 4 and 8 days after treatment. K2Cr2O7 induced reversible damage to the rat kidney function as indicated by serum creatinine (Scr) and urea nitrogen levels. The activities of BBM marker enzymes were significantly decreased in isolated BBM vesicles (BBMV) and homogenates of cortex and medulla on 1, 2 and 4 days after administration of K2Cr2O7with complete recovery to control values after 8 days. The decrease in the activities of the enzymes was mainly due to changes in maximum velocity (Vmax) values, while the Michaelis constant (Km) remained unchanged. The sodium dependent Pi transport across BBMV was reduced by 50% after treatment with K2Cr2O7. Thus, the administration of a single dose of K2Cr2O7 leads to impairment in the functions of renal BBM. These results suggest that the nephrotoxicity of K2Cr2O7 may be mediated, at least in part, by its effect on renal BBM.
Relation between bloodand urine-amphetamine concentrations in impaired drivers as influenced by urinary pH and creatinine
Authors: Jones A W , Karlsson L
Published: November 2005

Amphetamine undergoes extensive renal excretion and significant amounts are present in urine as the unchanged parent drug. This prompted us to investigate whether a quantitative relationship existed between blood and urine concentrations of amphetamine in the body fluids of drug-impaired drivers apprehended in Sweden, where this stimulant is the major drug of abuse. The relationship between blood and urine concentrations of amphetamine was determined by multivariate analysis with urinary pH and creatinine as predictor variables. Amphetamine was determined in blood and urine by gas chromatography-mass spectrometry with deuterium labelled internal standards. The concentration of amphetamine in urine was about 200 times greater than the concentration in blood; the mean and median urine/blood ratios were 214 and 160, respectively, with large individual variations. The Pearson correlation coefficient between urine (y) and blood (x) amphetamine was r=0.53, n=48, which was statistically highly significant (P<0.001), although the residual standard deviation (SD) was large (±181 mg/L). The correlation coefficient increased (r=0.60) when the concentration of amphetamine in urine was normalized for dilution by dividing with the creatinine content. When urinary pH and creatinine were both included as predictor variables, the correlation coefficient was even higher (r=0.69), now explaining 48% (r2=0.48) of the variation in urine amphetamine concentration. However, the partial regression coefficient for creatinine (53±28.7) was not statistically significant (t=1.85, P>0.05), whereas the corresponding regression coefficient for pH was highly significant and had a negative sign (-1029±32.6, t=- 3.12, P < 0.005). Other factors could impact on the urine-blood amphetamine relationship, such as route of administration, pattern of voiding and time elapsed after use of the drug.
Risk evaluation of occupational exposure to methylene dianiline and toluene diamine in polyurethane foam
Authors: Lewandowski T A , Hayes A W , Beck B D
Published: November 2005

Methylene diphenylisocyanate (MDI) and toluene diisocyanate (TDI) are widely used in industry to produce polyurethane foam products. Small amounts of methylenedianiline (MDA) and toluene diamine (TDA) are released during MDI and TDI polymerization and may be present in newly finished polyurethane foam parts. MDA and TDA concentrations in foam decline exponentially within several hours of demolding. MDA and the 2,4-isomer of TDA are known animal carcinogens and, in addition, have significant non-carcinogenic health effects. Our goal was to determine whether worker exposure to MDA or TDA in freshly produced polyurethane foams was associated with unacceptable health risks. Sampling and analysis of the fresh foam indicated that MDA and TDA concentrations varied considerably among products, but concentrations in all materials evaluated declined rapidly over time. We found that, under a worst-case exposure scenario, cancer risks from TDA exposure were approximately 5-10 6, whereas cancer risks from MDA exposure resulted in a tumorigenic margin of exposure (MOE) of 85 000. Non-cancer chronic hazard indices were well below 1.0. Therefore, the potential cancer and non-cancer health risks from MDA or TDA exposure to newly manufactured foam parts appear to fall well within acceptable health risk criteria.
Processes of Similarity Judgment
Authors: Larkey Levi B. , Markman Arthur B.
Published: December 2005

Similarity underlies fundamental cognitive capabilities such as memory, categorization, decision making, problem solving, and reasoning. Although recent approaches to similarity appreciate the structure of mental representations, they differ in the processes posited to operate over these representations. We present an experiment that differentiates among extant structural accounts of similarity in their ability to account for patterns of similarity ratings. These data pose a challenge for transformation‐based models and all but one mapping‐based model, the Similarity as Interactive Activation and Mapping (SIAM) model of similarity.
The homeoprotein engrailed 1 has pleiotropic functions in calvarial intramembranous bone formation and remodeling
Authors: Deckelbaum Ron A. , Majithia Amit , Booker Thomas , Henderson Janet E. , Loomis Cynthia A.
Published: December 2005

The membranous bones of the mammalian skull vault arise from discrete condensations of neural crest- and mesodermally-derived cells. Recently, a number of homeodomain transcription factors have been identified as critical regulators of this process. Here, we show that the homeoprotein engrailed 1(EN1) is expressed during embryonic and perinatal craniofacial bone development, where it localizes to the skeletogenic mesenchyme, and,subsequently, to calvarial osteoblasts and osteoprogenitors. Mice lacking En1 exhibit generalized calvarial bone hypoplasia and persistent widening of the sutural joints. A reduction in calvarial membranous bone deposition and mineralization (osteopenia) is coupled to enhanced osteolytic resorption in En1 mutants. Consistent with these observations,expression of established osteoblast differentiation markers reveals that En1 function is required for both early and late phases of calvarial osteogenesis. Further analysis shows that EN1 regulates FGF signaling in calvarial osteoblasts. Moreover, EN1 indirectly influences calvarial osteoclast recruitment and bone resorption by regulating the expression of receptor activator of NFκB ligand (RANKL) in osteoblasts. Thus, during intramembranous bone formation, EN1 acts both cell autonomously and non-cell autonomously. In summary, this study identifies EN1 as a novel modulator of calvarial osteoblast differentiation and proliferation, processes that must be exquisitely balanced to ensure proper skull vault formation.
Simulation of Pilot Workload for a Helicopter Operating in a Turbulent Ship Airwake
Authors: Lee D , Horn J F
Published: November 2005

This article describes a recent study in helicopter/ship dynamic interface simulation to examine pilot workload in the presence of a ship's airwake. The flight dynamics model represents a UH-60 helicopter and is based on the GENHEL software. This flight model has been updated to include a high-order dynamic inflow model and gust penetration effects of the time-varying ship airwake. The airwake model is derived from time-accurate computational fluid dynamics (CFD) solutions and provides an appropriately detailed level of fidelity to capture its effect on pilot workload. To simulate pilot control inputs for shipboard approach operations, an optimal control model of the human pilot is developed. The pilot model can be easily tuned to achieve different tracking performances, based on a desired crossover frequency, in each control axis and is designed to operate over a range of airspeeds using a simple gain scheduling algorithm. The pilot model is used to predict pilot workload for shipboard approaches in two different wind-over-deck conditions. Validation studies are conducted using both time and frequency domain analyses. The pilot control input autospectra predicted from the simulation model are compared to those of flight test data from the Joint Shipboard Helicopter Integration Process program. The paper also discusses the application of a stochastic airwake model for more efficient simulation. This new airwake model is derived from the simulation with the full CFD airwake by extracting an equivalent six-dimensional gust vector. The spectral properties of the gust components are then analysed, and shaping filters are designed to simulate the gusts when driven by white noise. It is proposed that the stochastic gust model can be used to optimize the automatic flight control system in order to improve disturbance rejection properties of the aircraft.
Computational Fluid Dynamics Simulations of Ship Airwake
Authors: Sezer-Uzol N , Sharma A , Long L N
Published: November 2005

Computational fluid dynamics (CFD) simulations of ship airwakes are discussed in this article. CFD is used to simulate the airwakes of landing helicopter assault (LHA) and landing platform dock-17 (LPD-17) classes of ships. The focus is on capturing the massively separated flow from sharp edges of blunt bodies, while ignoring the viscous effects. A parallel, finite-volume flow solver is used with unstructured grids on full-scale ship models for the CFD calculations. Both steady-state and time-accurate results are presented for a wind speed of 15.43 m/s (30 knot) and for six different wind-over-deck angles. The article also reviews other computational and experimental ship airwake research.
On Aerodynamic Modelling and Simulation of the Dynamic Interface
Authors: Zan S J
Published: November 2005

The past decade has seen significant advancements in modelling and simulation of the dynamic interface. The goal of the initial work in this area was to reduce the costs associated with first-of-class flight trials, and to deal with the backlog of aircraft-ship combinations for which flight-clearance envelopes were minimal or non-existent. A decade ago, piloted simulation of the dynamic interface appeared to be the obvious way to overcome these deficiencies. Validated models of fixed-wing and rotorcraft were in existence, and work began to combine these models with prescribed weather/lighting conditions (wind, rain, snow, fog, night, etc.), ship visuals, and motion. It had been envisioned that through the use of high-fidelity flight simulation, a test pilot could rapidly and safely determine the flight envelope boundaries without resorting to, or at least minimizing, flight trials.

During the past decade, significant advancements in simulation fidelity did transpire due to increased computational power, an improved understanding of airwakes, and enhanced simulation capabilities. The article describes some of the fundamental and applied research that contributed to the improved fidelity, much of it gained in a collaborative fashion. To date, modelling and simulation technologies have not advanced to the state where they can replace flight tests to derive flight-clearance envelopes, but they have approached the point where they can augment flight tests and serve in a training capacity. The accrual of a training benefit has recently emerged and is a significant, though unplanned, dividend from the efforts directed towards flight-envelope prediction. This article sets out to examine some of the strengths and deficiencies of the current capabilities, and provides a discussion of the way forward.

Modelling and simulation of the dynamic interface are discussed in a broad context, wherein they are defined to include non-piloted, non-real-time activities. The article will provide a critical review of many of these efforts to date, focusing primarily on aerodynamic issues. The article also discusses the challenges which are present for rotary-wing operations, for both small and large ships. It compares the environment in both cases and how that impacts the simulation requirements.
Shipborne Aviation: An Introduction
Authors: Newman S
Published: November 2005

The evolution of air vehicles for use on board a ship spans a period of nearly 150 years. Starting with observation balloons in the American Civil War, the development has moved to the Joint Strike Fighter, an aircraft of immense technical sophistication and a potent weapon. The design requirements of both ship and aircraft spawn conflicts and the two technologies are now required to work in total unison. This paper discusses the evolution and how the various wars have shaped the most demanding of aeronautical disciplines.
Dynamic and Aerodynamic Clearance of the Apache AH Mk1 Attack Helicopter for Embarked Operations
Authors: Neville T
Published: November 2005

The introduction into service of the Westland manufactured Apache AH Mk1 has coincided with a thrust within the UK armed services for a greater emphasis on amphibious operations within the littoral environment. From this background has emerged a requirement for an embarked, attack helicopter capability, for which the Apache AH Mk1 has been earmarked. However, this helicopter being, by design, optimized for the battlefield environment, cannot be presumed to adapt to the naval environment without presenting certain challenges. This article describes how Westland Helicopters Ltd has sought to determine the feasibility of conducting embarked operations with Apache AH Mk1 by deriving limits to be respected during Ship Helicopter Operating Limits (SHOL) trials using a variety of analytical methods. Aspects of operation considered include aircraft lashing, landing, stability on deck with rotors running or stationary and when being towed, rotor engagement and disengagement, ground resonance, and main rotor spreading and folding. The article considers further aspects of importance to embarked operations and summarizes the trials process that results in an operational envelope for service use. It concludes that a practical operating envelope can be achieved, anticipates a successful outcome for the SHOL trials, and includes a projection for future activities to enhance the aircraft's maritime operational capabilities.
A Simulation Study of Helicopter Ship Landing Procedures Incorporating Measured Flow-Field Data
Authors: Thomson D G , Coton F , Galbraith R
Published: November 2005

The aim of this article is to investigate the use of inverse simulation to help identify those regions of a ship's flight deck which provide the safest locations for landing a rotorcraft in various atmospheric conditions. This requires appropriate information on the wind loading conditions around a ship deck and superstructure, and for the current work, these data were obtained from wind tunnel tests of a ship model representative of a typical helicopter carrier/assault ship. A series of wind tunnel tests were carried out on the model in the University of Glasgow's 2.65 × 2.04 m wind tunnel and three-axis measurements of wind speed were made at various locations on the ship deck. Measurements were made at four locations on the flight deck at three different heights. The choice of these locations was made on the basis of preliminary flow visualization tests which highlighted the areas where the most severe wind effects were most likely to occur. In addition, for the case where the wind was from 30° to starboard, measurements were made at three further locations to assess the extent of the wake of the superstructure. The generated wind profiles can then be imposed on the inverse simulation, allowing study of the vehicle and pilot response during a typical landing manoeuvre in these conditions. The power of the inverse simulation for this application is demonstrated by a series of simulations performed using configurational data representing two aircraft types, a Westland Lynx and a transport helicopter flying an approach and landing manoeuvre with the worst atmospheric conditions applied. It is shown from the results that attempting to land in the area aft of the superstructure in a 30° crosswind might lead to problems for the transport configuration due to upgusts in this area. Attempting to perform the landing manoeuvre in an aggressive manner is also shown to lead to diminished control margin in higher winds.
Quantification and Prediction of Pilot Workload in the Helicopter/Ship Dynamic Interface
Authors: Bradley R , Macdonald C A , Buggy T W
Published: November 2005

The evaluation, early in the design cycle, of the limits for operating aircraft from ships in a wide range of sea states and atmospheric conditions has become an important issue for two main reasons. First, the simultaneous entry into service of new helicopter types and new naval platforms has generated an enormous task in the development of appropriate Ship Helicopter Operating Limits for in-service operations. Second, it has become clear that such operational factors need to be addressed at the design stage - which of necessity involves developing a predictive capacity in all of the areas which influence operational capability.

These considerations need to take place in the context of technological advances which seek to assist the pilot in operations from ships. Improved radar for ship approaches and enhanced cueing, located around hangars and landing spots, are both areas which are being continually developed in association with upgraded aircraft systems for guidance, control, and stability augmentation. Ultimately, however, the situation comes down to the pilot's assessment of the workload involved in any task and the handling qualities of the vehicle being controlled.

For this reason there has been a growing interest in two related areas: (i) the development of metrics to provide a consistent indicator of pilot workload and (ii) the enhancement of existing pilot models to generate authentic control activity in the aircraft/ship dynamic interface.

This article describes recent techniques for extracting workload metrics from control activity and indicates the extent to which acceptably accurate workload predictions can be made. Some advances in pilot modelling are also described and examples are given to demonstrate the capability and limitations of currently available methods.

Finally, the present state of integration of the two aspects into a robust tool for ship and aircraft system design is discussed. The focus of this article is, of necessity, on helicopter operations because that is where most of the current work has been centred.
Bond Graph Modelling for Non-Linear Hydro-Mechanical Systems
Authors: Margolis D , Shim T
Published: November 2005

Bond graphs are a concise pictorial representation of the interactive dynamics of all types of engineering systems. Relatively few symbols are needed to represent these systems, and this includes non-linear mechanics interacting with hydraulic or pneumatic subsystems. Agricultural and construction equipments and vehicles are examples of such complex systems.

Assembling overall system models of such complex systems can be very difficult without a unifying procedure that indicates computational causality as the model is developed. Bond graphs allow for the continuous assessment of causality as a model is developed, regardless of the non-linearity of the individual pieces. This causality indicates computational problems and allows the modeller to address these problems prior to deriving equations or attempting to simulate the system.

The development of such models is done here as generally as possible, but is applied to an unstable backhoe as an example. The systematic modelling procedures of a backhoe are used for the development of individual subsystems which are then combined into an overall computational model.
Simulation of Motor-Scooter Drop Testing by a Multi-Body Finite Element Integrated Approach
Authors: Frendo F
Published: November 2005

The drop test is employed in the motor-scooter industry for evaluating the frame performance under particularly severe conditions. In this work, a numerical procedure developed for simulating the test is presented. The procedure includes a multi-body model for the evaluation of the maximum loads acting on the scooter frame during impact at ground. Such loads were then employed in a non-linear static finite element analysis in order to obtain the permanent frame deformation.

The experimental activity carried out for vehicle characterization and the experimental apparatus set up for tests are also presented in detail. The multi-code approach appeared versatile and straightforward, and furnished results in satisfactory agreement with experiments.
Modelling Commercial Vehicle Handling and Rolling Stability
Authors: Hussain K , Stein W , Day A J
Published: November 2005

This paper presents a multi-degrees-of-freedom non-linear multibody dynamic model of a three-axle heavy commercial vehicle tractor unit, comprising a subchassis, front and rear leaf spring suspensions, steering system, and ten wheels/tyres, with a semi-trailer comprising two axles and eight wheels/tyres. The investigation is mainly concerned with the rollover stability of the articulated vehicle. The models incorporate all sources of compliance, stiffness, and damping, all with non-linear characteristics, and are constructed and simulated using automatic dynamic analysis of mechanical systems formulation. A constant radius turn test and a single lane change test (according to the ISO Standard) are simulated. The constant radius turn test shows the understeer behaviour of the vehicle, and the single lane change manoeuvre was conducted to show the transient behaviour of the vehicle. Non-stable roll and yaw behaviour of the vehicle is predicted at test speeds >90 km/h. Rollover stability of the vehicle is also investigated using a constant radius turn test with increasing speed.

The articulated laden vehicle model predicted increased understeer behaviour, due to higher load acting on the wheels of the middle and rear axles of the tractor and the influence of the semi-trailer, as shown by the reduced yaw rate and the steering angle variation during the constant radius turn. The rollover test predicted a critical lateral acceleration value where complete rollover occurs. Unstable behaviour of the articulated vehicle is also predicted in the single lane change manoeuvre.
Analysis of Thin Plate Structures Using the Absolute Nodal Coordinate Formulation
Authors: Dufva K , Shabana A A
Published: November 2005

The absolute nodal coordinate formulation can be used in multibody system applications where the rotation and deformation within the finite element are large and where there is a need to account for geometrical non-linearities. In this formulation, the gradients of the global positions are used as nodal coordinates and no rotations are interpolated over the finite element. For thin plate and shell elements, the plane stress conditions can be applied and only gradients obtained by differentiation with respect to the element mid-surface spatial parameters need to be defined. This automatically reduces the number of element degrees of freedoms, eliminates the high frequencies due to the oscillations of some gradient components along the element thickness, and as a result makes the plate element computationally more efficient. In this paper, the performance of a thin plate element based on the absolute nodal coordinate formulation is investigated. The lower dimension plate element used in this investigation allows for an arbitrary rigid body displacement and large deformation within the element. The element leads to a constant mass matrix and zero Coriolis and centrifugal forces. The performance of the element is compared with other plate elements previously developed using the absolute nodal coordinate formulation. It is shown that the finite element used in this investigation is much more efficient when compared with previously proposed elements in the case of thin structures. Numerical examples are presented in order to demonstrate the use of the formulation developed in this paper and the computational advantages gained from using the thin plate element. The thin plate element examined in this study can be efficiently used in many applications including modelling of paper materials, belt drives, rotor dynamics, and tyres.
Pseudo-Dynamic Method for Structural Analysis of Automobile Seats
Authors: Carneiro J O , de Melo F J Q , Pereira J T , Teixeira V
Published: November 2005

This work describes the application of a pseudo-dynamic (PsD) method to the dynamic analysis of passenger seats for the automotive industry. The project of such components involves a structural test considering the action of dynamic forces arising from a crash scenario. The laboratory certification of these automotive components consists essentially on the inspection of the propagation and extension of plastic deformations zones in metallic members of the seat structure as consequence of the mutual action between the seat and the passenger fastened to the seat via seat belt anchorages. This work presents a relatively simple experiment using PsD techniques as a novel method to perform a test equivalent to the dynamic model of a dummy-seat pair subjected to impulsive loads from a car crash.

Essentially, the PsD test method is a hybrid and hierarchic computer-driven testing procedure where a numerical algorithm and experimental step are used and combined on-line in order to solve a problem in the scope of structural dynamics. The implementation of the method is not expensive and has the leading advantage of offering the operator a total control of any intermediate structure state during the test still keeping the realism of a real dynamic testing.
Container Gantry Crane Simulator for Operator Training
Authors: Rouvinen A , Lehtinen T , Korkealaakso P
Published: November 2005

Real-time simulators have become more popular in the field of user training. This is due to the possibility to give basic training and knowledge of machines and their operation environment to the operator even when the machine is not actually present. The use of simulators instead of actual machines has several advantages. First of all, the available machine capacity is not tied to training and can be used in productive work. Secondly, using a simulator helps to avoid accidents that may occur using real machines. Using a simulator also enables different environmental aspects, such as lighting conditions, fog, wind, and so on, to be taken into account in the training of all operators alike. Real-time training simulators are complicated machine systems, which consist of a user interface, an I/O-system, a real-time simulation model describing the dynamics of the machine in question and its connections to the environment, a visualization of the operational environment, and a possible motion platform. The user interface is usually taken directly from the simulated machine. Consequently, the user has the possibility to become familiar with the operating interface in an early phase of training.

In this article, the development of a gantry crane operator-training simulator, including all the earlier mentioned components, is presented. The aim of this article is to present an example of methods used in the development of the separate areas of a training simulator.
Direct Kinematic Singularities of 3-3 Stewart-Gough Platforms
Authors: Liu C H , Chiu J
Published: November 2005

In this article, a method to locate direct kinematic singularities of a 3-3 Stewart-Gough parallel manipulator (called a Stewart manipulator henceforth) is proposed. The Stewart manipulator is first replaced by an analogous manipulator, the 3PRPS parallel manipulator, and as the first three active joints of this manipulator remain fixed, this manipulator reduces to an asymmetric 3RPS parallel manipulator. With all moving platform's degrees of freedom, except its height, properly specified, there exists at least one height that gives rise to direct kinematic singularity of the asymmetric 3RPS manipulator and this height is a root of a cubic polynomial equation. The procedure to locate direct kinematic singularities thus reduces to solving cubic polynomial equations. Numerical results show that every singular configuration of the asymmetric 3RPS manipulator thus-determined is also a singular configuration of the 3-3 Stewart-Gough platform.
Workpiece Deflection Compensation Using a Two-Dimensional Toolposts
Authors: Yan W Y , Al-Jumaily A M
Published: November 2005

Considering the workpiece elastic deflection in a turning process, a simulation model that accounts for the radial and tangential vibrations and their abatement using active control is developed. The model is simulated using Simulink in a Matlab environment to assess the possibility of using an active actuator to reduce vibrations in two directions. The results demonstrate the significance of the workpiece elastic deformation and its compensation using active actuators. Actuators that can compensate for the piece deflection and the vibrations due to the surface roughness are speculated upon.
Guinea worm infection of urinary bladder manifesting as obstructive uropathy in rural Maharashtra
Authors: Birare Shivaji D , Kamble M H , Lanjewar D N , Parija S C , Girji D D , Kulkarni P V , Gupta Rashmi S , Abdul Jabbar A M
Published: November 2005

Guinea worm or Dracunculus medinensis is a well-documented helminthic infestation in many areas of Asia. In this report, we describe a rare case of guinea worm infestation in a 25-year-old woman who had developed symptoms of obstructive uropathy, in whom fragments of guinea worm were removed after urethral catheterization. To the best of our knowledge, adult guinea worm occurring in the urinary bladder has not been previously described.
A survey of the use of medicinal plants and other traditional medicine in Kasese District, Uganda
Authors: Challand S
Published: November 2005

The use and value of traditional plants and medicines is only slowly being investigated by Western medical organizations. A survey of 492 members of support groups and health-care clinics in Kasese district, Uganda was undertaken in a group setting: 23 groups with a mean size of 21, age range 4-53, which represented 0.1% of the population, covering nine of the 20 sub-counties, both in the native languages and in English, using photographs and specimens of 12 plants. Most admitted to using plants at some time 81% for self, 77% for their children; 45% admitted to using traditional healers as a source for information about health. Most plants were home grown or available locally. Medicinal plants were used for respiratory infections, fever, malaria and diarrhoea/vomiting. HIV/AIDS was rarely treated with medicinal plants.
Determining the sensitivity of sitting height in predicting cephalo pelvic disproportion in Eritrea
Authors: Sebhatu B
Published: November 2005

To determine the sensitivity of sitting height in predicting cephalo pelvic disproportion (CPD), a prospective case-control study was conducted. A total of 724 primiparas who delivered in Mekane Hiwot Maternity Hospital, Asmara, Eritrea were studied. Primiparas who delivered by caesarian section because of CPD were taken as cases (221), and primiparas who delivered vaginally were taken as controls (503). Height was measured for all, while sitting and while standing. The sensitivity of sitting height in predicting CPD was 34.1% (95% confidence interval [CI] = 27.7-40.3%), while that of the standing height was 33.5% (95% CI = 27.1-39.84). CPD cannot be predicted accurately by height in general and by sitting height in particular. Therefore, in order to avoid obstetric complications, all pregnant women should have access to skilled attendance during delivery and access to facilities with emergency obstetric care when needed.
Choice of drainage procedure in paediatric pyopericardium: a 30-year experience
Authors: Hayavadana Rao P V , Raveenthiran V
Published: November 2005

Although there is general agreement on the necessity of draining pyopericardium, debate continues as to the safe and effective method of drainage. Studies describing head-to-head comparison of various drainage procedures are very few and are disadvantaged by small numbers of cases. In this observational study, we review our 30-years experience with different techniques of pericardial drainage. Between 1972 and 2003, the authors have personally treated 39 children who suffered from pyopericardium. Among the 22 children who underwent early partial pericardiectomy, 20 were alive. In contrast to this,12 out of 15 children treated with repeated pericardiocentesis or sub-xiphoid tube drainage were dead. The median hospital stay for pericardiectomy group was 18 days (range 11-32) and that for the non-thoracotomy group was 34 days (range 18-55 days).

With regard to immediate survival and early convalescence in the pyopericardium, partial pericardiectomy is superior to pericardiocentesis and sub-xiphoid tube drainage. Pericardiocentesis can be used for diagnostic or temporizing purposes, but not as the definitive drainage procedure. Partial pericardiectomy can be done even in small hospitals where heart-lung machines are not available.
Comparison of albendazole regimen for prophylaxis of strongyloides hyperinfection in nephrotic syndrome patients on long-term steroids in Cambodia
Authors: Leang Bunse , Lynen Lut , Schrooten Ward , Hines Jennifer
Published: November 2005

Nephrotic syndrome patients on long-term steroids face the risk of having heavy uncomplicated strongyloidiasis or death from its extreme form, the strongyloides hyperinfection. The risk can be minimized if we eradicate the parasite first. We compare a once daily and twice daily albendazole regimen in preventing this potentially fatal complication in 122 patients with nephrotic syndrome.
Epidemiological study of patients with connective tissue diseases in Brazil
Authors: Moreira Almeida Maria Do Socorro Teixeira , Bértolo Manoel Barros , Da Silva Benedito Borges , De Deus Filho Antônio , Almeida Mayra Moreira , Veras Fabíola Ferreira Hortêncio , Mendes Luciano Cardoso
Published: November 2005

To study the prevalence of connective tissue disorders and identify the epidemiological profile of the population from the northern and northeastern regions of Brazil. All patients admitted to the general medical ward at Getulio Vargas Hospital were screened through history and physical examination for the existence of known, suspected or possible connective tissue disorder. A total of 120 patients were enrolled in the study - 61 (50.8%) with systemic lupus erythematosus (SLE), 41 (34.2%) with rheumatoid arthritis (RA), 16 (13.3%) with systemic sclerosis (SS), one (0.8%) with mixed connective tissue disease (MCTD) and one (0.8%) with polymyositis (PM). Women accounted for (104) 86.7% of the participants and (83) 70.9% were non-Caucasians. The mean age was 36.8 years. Alopecia was the most frequent symptom (55/46.6%), followed by other cutaneous lesions (50/42.4%), dyspnea (47/39.8%) and chest pain (39/33.0%). The most frequent rheumatologic disorder encountered in our hospital-based study population was systemic lupus erythematosus, which is contrary to findings of the majority of studies performed in this country.
Peritonitis in patients over the age of 50 years: 98 cases managed surgically
Authors: Subramanyam S G , Sunder N , Saleem K M , Kilpadi A B
Published: November 2005

Generalized peritonitis in patients over the age of 50 years is a common surgical emergency. This is a retrospective analysis of 98 cases managed surgically. Duodenal ulcer perforations, necrotizing enteritis, acute cholecystitis with perforation and small bowel perforations were the common causes. Most of them presented late, and many had associated conditions. Re-look laparotomies had a definite role to play. While there is significant decrease in the number of typhoid and tubercular peritonitis, there appears to be an increase in the incidence of necrotizing enteritis and acute cholecystitis.
Drug use among adolescents in Ilorin, Nigeria
Authors: Abdulkarim A A , Mokuolu O A , Adeniyi A
Published: November 2005

The types and frequency of drug use among 1200 students aged 10-19 years was investigated and a prevalence rate of 40.1% found; currently used drugs included mild stimulants such as kolanut and coffee 294 (26.2%), alcohol 164 (14.5%), sniffing agents 80 (7.2%), amphetamine and ephedrine 66 (6.7%), cigarette 54 (4.8%), heroin 45 (4%) cocaine 40 (3.6%) and cannabis 38 (3.4%).

Multiple drug use was found among the students, with the abuse of cannabis, cocaine and heroin being significant among those who smoked cigarette ( P<0.001). The relative risk (RR) for cannabis use when cigarette was smoked was 37.4 (24.1-57.8); RR for cigarette smoking when alcohol was used, 6.8, while RR for cocaine abuse when cigarette was used, 21.8 (13.9-34.5) and 52.8 (29.2-95.5) when cannabis was used. It is therefore concluded that the use of the licit and 'socially' acceptable drugs may pave the way for the abuse of illicit ones.
Incidence of fungi pathogens associated with root canal treatments, in Benin City, Nigeria
Authors: Ogude G O , Akerele J O
Published: November 2005

In order that appropriate clinical interpretation of microflora and drug management of root canal infections would be achieved, the fungi contents of root canal following biomechanical instrumentation were determined. Mucor, yeast, candida, microsporium and fusarium species were recovered at the different stages of instrumentation. The presence of fungi could complicate root canal treatments. The possible implications of these findings in treatment failures are highlighted.
Deaths associated with anaesthesia in Togo, West Africa
Authors: Ouro-Bang'na Maman A F , Tomta K , Ahouangbévi S , Chobli M
Published: November 2005

This study attempts to determine the anaesthetic death rate, the causes of deaths and the avoidable mortality rate (AMR) in consecutive cases. The number of anaesthetics given was 1464: 30 cases died within 24 h. The incidence of 24-h perioperative deaths per 100 anaesthetics was 2.57. In all, 50% of deaths were observed in obstetric surgery; 47% of deaths were associated with cardiovascular management, 30% with respiratory management; 93% of deaths were identified as avoidable. The AMR was 1.5% (anaesthetic AMR: 0.75%, administrative AMR: 0.68%, surgical AMR: 0.07%). Insufficient or no blood available is the only factor for administrative AMR.