bluuebunny/crossref_metadata_2025 huggingface dataset:
Validation of an SPH Sloshing Simulation by Experiments
Authors: Pa´kozdi Csaba , Graczyk Mateusz
Published: February 2010

Sloshing is a violent fluid motion and is of current interest for many branches of the industry, among them gas shipping. Numerical methods are an important tool for analyzing sloshing. Among them, methods based on the smooth particle hydrodynamics (SPH) are particularly promising for analyzing violent fluid impacts. Previous work shows a good agreement in terms of free surface elevation between SPH simulation and experiments. An extensive comparison in terms of pressure in the tank is missing. This is due to the fact that availability of reliable and accurate pressure measurements is limited. Therefore sloshing experiments in a two-dimensional tank are performed. A regular one-degree-of-freedom motion with small amplitude is imposed for various frequencies around fluid natural frequency and three filling levels in range 17–40% of the tank length. By means of pressure sensors mounted on the vertical tank wall the pressure is measured for a non-impact type fluid motion. Free surface elevation is measured by wave probes and a high speed video recording is taken. An in-house SPH code is presented in detail. Standard SPH formulation is modified with the focus on implementation of the Verlet time scheme. The Verlet time integration scheme makes it possible to perform long time sloshing simulations due to its good momentum and energy conservation properties. A diffuse term coefficient is applied in the continuity equation. Investigated sloshing cases are without violent fluid impacts. Using artificial mass diffusion term in SPH simulations is expected not to significantly influence the pressure field. The paper shows that applying this technique with carefully chosen coefficient does not lead to any nonphysical phenomena in the SPH simulation for such a sensitive phenomenon as sloshing. By comparing the SPH simulations to the quasi-analytical multimodal method and experiments the code and diffuse term coefficient are validated.
Hydrodynamic Coefficients for Vortex Induced Vibrations of Slender Beams
Authors: Soni Prashant K. , Larsen Carl M. , Wu Jie
Published: February 2010

Empirical codes for prediction of vortex induced vibrations need reliable data for hydrodynamic coefficients. Such data are almost exclusively based on measured forces on rigid cylinders that have forced harmonic motions in cross-flow (CF) or in-line (IL) directions. This type of experiment is not able to capture all effects that could be important for realistic cross section motions of slender beams due to two reasons: 1. Slender beams will normally have combined IL and CF oscillations. 2. Higher order frequency components will normally be present for vibrating beams. It is difficult to measure local forces on short segments of flexible beams in laboratory tests due to the small diameters. The most convenient instrumentation is to use a large number of strain gauges or accelerometers along the beam. Proper data processing will then give reliable data for the motions, which means that the trajectory of cross sections can be found. Hence, the following set of experiments can be carried out in order to find hydrodynamic coefficients under realistic VIV conditions: 1. Experiments with a slender flexible beam and processing of recorded strains or accelerometers to identify cross section trajectories. 2. Measurement of forces on a rigid cylinder section with forced motions. Reynolds number, amplitude ratio, orbit shape and non-dimensional frequency must be identical in the flexible beam and rigid cylinder tests. Such experiments have been carried out, and the results are presented in terms of hydrodynamic coefficients for combined CF and IL oscillations. Coefficients are found for the primary CF and IL frequencies, but also for higher order frequency components. Results are presented and discussed in relation to well known results from pure CF and IL oscillations. One way of verifying that the coefficients have been correctly identified, is to apply the coefficients in an empirical response model and compare analysis results to the observation. This step has, however, not been carried out so far.
Field Measurements of Vortex Induced Motions of a Deep Draft Semisubmersible
Authors: Rijken Oriol , Leverette Steve
Published: February 2010

Vortex Induced Motion (VIM) of a Deep Draft Semi® with four square columns has been observed in model tests and in the field for a prototype configuration. The model test observations were developed into design guidance procedures. Some of the assumptions based on the model test results are validated with the field observations. A quantitative description of the field measurements is presented. A comparison between the field observations and the design guidance is provided.
Conceptual Design and Key Technology Development of a Long-Range Underwater Vehicle Traveling Over Thousands Kilometers
Authors: Yoshida Hiroshi , Takao Sawa , Hyakudome Tadahiro , Ishibashi Shojiro , Ochi Hiroshi , Shimura Takuya , Tahara Junichiro , Watanabe Takayoshi , Inoue Tomoya , Tsukioka Satoshi , Aoki Taro
Published: February 2010

The underwater platform which has enough ability to cruise globally and freely in vast deep sea will allow us to make the survey of entire oceans. We aim to develop an underwater platform which travels and surveys across entire oceans for the research into the global change, ocean-trench earthquake, and biodiversity and so on. We have developed the first prototype underwater platform or the long-range cruising autonomous underwater vehicle (LCAUV) named Urashima since 1998. The vehicle powered by a polymer electrolyte fuel cell system marked the world record of cruising distance of 317 kilometers in 2005. The vehicle has the following specifications: length; 10 m, weight; 10 tons, maximum depth ratings; 3500 m, maximum cruising speed; 3.2 knots, and endurance; 60 hours. This large vehicle has large user payload of a few hundreds kilograms. In 2007, we started research and development of the elemental technologies which will be utilizes for development of the second generation LCAUV to achieve cruising range of over 3000 kilometers. The technologies under research and development are power sources, navigation methods, communication methods, vehicle controllers, materials for body, and advanced sensors for highly resolution survey. The fuel cell and secondary battery hybrid system is had to improve at energy efficiency to generate electricity as possible for long time running with limited energy. A high accuracy inertial navigation system and an underwater positioning system being covered area of over 1000 km are under development. A synthesized aperture sonar is also under development.
Investigation of Insect Hovering From the Perspective of a Force Element Theory
Authors: Hsieh Cheng-Ta , Kung Chun-Fei , Chu Chin-Chou , Chang Chien C.
Published: February 2010

Bird or insect flight has been of great interest to general audience, not only to scientists. Numerous works have been devoted to the study of aerodynamics of insect wings, for example, the hovering flight. It is generally considered that the lift supporting the insect comes from the unsteadiness of the flight. However, the term “unsteadiness” itself is loose and imprecise at all. It may include several unsteady components: the motion of wing, vortex in the flow as well as the surface vorticity. The various contributions are now examined from the perspective of a force element theory to gain more insight into the mechanisms of generating lift.
EquiMar: The Development of Protocols for the Equitable Evaluation of Marine Energy Systems
Authors: Smith George H. , Bittencourt Claudio , Ingram David
Published: February 2010

This paper describes a major collaborative project funded through the European Union which seeks to accelerate the adoption of ocean energy systems through providing a rational suite of protocols that will: (i) help to match technology and scale of deployment to site specific considerations; (ii) define acceptable methodologies to evaluate the environmental consequence of deployment; (iii) develop techniques for equitable comparison of the economic potential; for the deployment of small to medium arrays. EquiMar involves 23 European partners, including scientists, engineers, ecologists and developers. Funded through the European Commission 7th Framework Programme [1] (grant agreement 213380), this €5.5 million project aims to produce a suite of protocols that will enable a broad range of stakeholders to judge the variety of technologies in wave and tidal energy on a level playing field. The protocols will reflect the entire development cycle of a marine device: resource assessment and site selection; fundamental engineering design; scaling up and deployment; environmental impact and economic assessment. The project has now been running for 12 months. This paper reviews the intended work over the three year project, but focuses on the development of “high level” documents that will describe the aims and remit of the individual protocols. The high level protocols were conceived to meet two fundamental requirements. EquiMar is an ambitious project in terms of both scope and number of collaborators. There is a need to maintain consistency and clarity as each protocol/ guideline is developed. The high level protocols will serve as a template for the detailed specifications, clarifying content, identifying gaps and links within the overall work and finally will help to maintain focus on the final goals. Externally the high level documents will provide a mechanism for engagement of the many stakeholders. Early feedback on the direction and coverage of the protocols is fundamental to achieving, where practica, a consensus from the diverse ocean energy community. Based on the practices of an international Certifying Agency (DNV) it is intended that the protocols will be fit for guidance and incorporation into proposed international standards. This paper aims to increase dissemination and provoke comment from the International marine community in order that that the final documents will be fit for purpose by reflecting the considered opinion of as wide a body of relevant contributors as is possible, and act as a catalyst to help deliver the potential for marine renewable energy on the international stage.
Deepwater SCR Installation With the HLV Thialf
Authors: Wever Roger , Hendriks Pascal
Published: February 2010

Deep water oil and gas exploration make regularly use of Steel Catenary Risers (SCR) to transfer oil and gas from wellheads to host. From the host the oil and/or gas is transferred (after processing) to subsea pipelines by SCRs. Regular practice is to have the SCRs pre-laid on the seabed prior to host installation. Last Summer Heerema Marine Contractors utilized the Heavy Lift Vessel (HLV) Thialf to recover and install 8 pre-laid SCRs. The HLV Thialf also installed the Tension Leg Platform host. The SCRs: two 6″, two 8″, two 10″ SCRs, a 12″ Export Gas SCR, a 16″ Export Oil SCR were pre-laid in multiple crossings pattern around the TLP. The A&R winch was used to recover the SCRs from approximately 1,350 m waterdepth followed by SCR hand-over to one of the Thialf’s heavy lift cranes for installation to the host. This paper will focus on the SCR recovery and hang-off operation. Several topics will be discussed: the pre-lay, subsea hand-over and the large vessel rotation performed for SCR installation. Additionally, first time use items such as the welded eye connection, open top container for pull-in wire storage and the newly designed hydraulic shackle will also be presented.
Most Recent Developments for Monitoring and Controlling the Annulus Conditions of Marlim-Sul Flexible Risers
Authors: Rabelo Alexandre S. , Motta Antonio , Romero Antonio , C. e S. Nunes Joa˜o Paulo , Zaganelli Jose´ L. , Brack Marcelo
Published: February 2010

The main objective of this paper is to present the recent developments for monitoring and controlling the annulus conditions of flexible risers. Petrobras has been monitoring the pressure of permeated gas in the annulus region of some risers in order to infer the eventual occurrence of non-conformities as damage on the riser external sheath, for example. Such occurrence would affect the permeated gas flow pattern, the gas pressurization period and the relief valve opening frequencies. Furthermore, the mentioned occurrence would increase the susceptibility of the steel armors to experience the potential failure mechanism of corrosion. In Petrobras, the current monitoring method is characterized by visual and periodic manometer readings from a manometer set installed near each riser end-fitting. The data is recorded in a daily report and analyzed by personnel onshore, who are in charge of comparing data and requesting relief valve’s actuation, whenever necessary. The paper illustrates Marlim-Sul Asset experience on monitoring and data processing to control the annulus conditions of flexible risers during operation. It presents the in-house developed methodology to data management and processing. This methodology is based on a daily analysis of the permeated gas data worksheet. Some examples are given to illustrate it. The paper also summarizes current developments, in progress, in order to improve riser integrity management. The first development is being done to implement, in the future, automatic data acquisition and control systems. The purpose of automating this process is to improve methods and techniques for data acquisition, transmission and processing. The second development focuses on applications in which riser top end-fittings are submerged. In this particular scenario, a special system — with a quick connection subsea device — is under development to allow the connection, by divers, after the riser pull-in, of the riser annulus to the platform gas collecting facilities. The idea is prevent seawater ingress into the riser annulus during installation, maintenance and operational phases. Therefore, the permeated gas pressure can be monitored and the annulus behavior can be controlled from the surface. The final expectation is to improve riser integrity management, providing another source of information at low cost, helping technicians to decide whenever it is time to inspect, repair or replace a riser, preventing hydrocarbon leakage to the environment.
Hydrogen Embrittlement of 8630M/625 Subsea Dissimilar Joints: Factors That Influence the Performance
Authors: Beaugrand Viviane C. M. , Smith Lee S. , Gittos Mike F.
Published: February 2010

Following the failure of a small number of subsea dissimilar joints, there is significant interest in understanding the fracture mechanism(s) and in qualifying future items for avoidance of further failures. Subsea dissimilar joints typically comprise a butter weld deposit onto the joint face of an alloy steel forged hub/tee/elbow, postweld heat treated, and completed with a closure weld to a pipeline steel. The case examined in this paper, consists of a build up of alloy 625 onto an 8630M forging. Hydrogen embrittlement test methods are described and the results from the tests interpreted with respect to their implications for fabrication and service. The microstructure and chemistry across the dissimilar interface is found to be of fundamental importance, and this is illustrated by the relative performance of gas-tungsten arc (GTA), hot-wire GTA and friction welds. Guidance for fabrication, installation and service is given for avoidance of further hydrogen embrittlement failures.
Transformation of Mono- and Multi-Chromatic Water Waves Propagating From a Quasi-Deepwater to a Shallow Water Region
Authors: Zaman M. Hasanat , Baddour Emile
Published: February 2010

A vertically integrated 3D numerical model that uses the concept of depth average velocity distribution with enhanced dispersion characteristics investigates the propagation and transformation of mono- and multi-chromatic waves from a quasi-deep region to shallow water region. A finite difference method has been employed for the numerical computation that follows ADI (Alternating Direction Implicit) algorithm. The local sea bottom is uneven and turns into a moderately shallow water due to presence of a ridge-like bottom near the coast. The bottom configuration is from a location off Nova Scotia coast in Canada. Detail results and discussions are presented.
Microstructure and Galvanic Corrosion of Dissimilar Weldment Between Duplex Stainless Steel UNS 31803 and X80 Steel
Authors: Wang Xiaoyan , Zhang Lei , Kuang Xianren , Lu Minxu
Published: February 2010

Kela-2 Gas Field is the main supply for the West-East Gas Pipeline which runs across China with length of 4000 kilometers. Natural gas from Kela-2 contains CO2/H2S sour components and 10% condensation water, which makes the medium present very strong corrosivity. In avoidance of corrosion failure, DSS UNS S31803 line pipes were introduced to transmit the gas from the Gas Field to gathering center and processing factory. And it is the first time DSS pipes which is totally about 13km were widely used in oil and gas pipeline around the world. As it is known, DSS UNS S31803 pipes and traditional linepipes X80 were welded together between the gathering lines and mainline. Duplex stainless steel (DSS) UNS S31803 and X80 were welded by metal inertia gas welding (MIG) with consumable ER2209, and the joints take on good mechanical properties. The type II boundary close to the fusion boundary at the carbon steel side was observed by SEM. Obvious concentration gradient of Ni and Cr was observed in the region between the two boundaries, where the hardness was much higher. The weld metal with columnar and some polygonal ferrites take on good passivation against test solution. The heat affected zone beside the X80 base material is mostly granular bainite, some polygonal ferrites and few MA, X80 base material present obvious rolling state, the microstructure of which is the same to X80 heat affected zone, but the level of crystal size reach to 11.6. The corrosion behavior of them dosen’t have any difference, but the corrosion potential of X80 HAZ is much higher than X80 BM, about 50 mv, the corrosion rate of X80 HAZ is also much higher than X80 base material. Potential curves of different weldment regions were also studied in 3.5% NaCl solution and 3.5% NaCl solution with saturated CO2. Galvanic corrosion behavior of weld metal and X80 steel was also tested and the conclusion is: The cathode reaction is controlled by oxygen diffusion, and when area ratio S (S = Ac / Aa, Ac is the area of DSS WM, Aa is the area of X80 BM) increases, corrosion current of X80 is enhanced rapidly, which is called “gathering principle”. When the weld metal and X80 coupled, cathode has much higher polarization potential and is protected completely.
Current Affairs: Model Tests, Semi-Empirical Predictions and CFD Computations for Current Coefficients of Semi-Submersibles
Authors: Vaz Guilherme , Waals Olaf J. , Ottens Harald , Fathi Fahd , Le Soue¨f Tim , Kiu Kwong
Published: February 2010

Current loads on stationary vessels have been investigated as part of the Current Affairs Joint Industry Project (JIP). Model-tests, semi-empirical models and CFD methods were used to predict these loads. This paper examines one configuration out of the eight tested in the JIP; an idealized semi-submersible consisting of two square rounded-corner columns connected with a pontoon. The model experiments, empirical model predictions and CFD results are presented and discussed. ‘Blind’ and ‘Improved’ CFD computations (with and without knowledge of the experimental results) have been carried out by the JIP participants. Comparisons between these results are made, deviations from the experimental data are quantified and conclusions are drawn. Two key issues for modeling accuracy are identified and discussed; the location of the transition to turbulent flow and the control of the numerical errors.
Joint Assessment of Offshore Wind and Wave Energy Resources for the Portuguese Pilot Zone
Authors: Pontes M. Teresa , Costa Paulo , Bruck Miguel , Carvalho Anabela
Published: February 2010

The objective of this paper is to present the joint assessment of offshore wind and wave energy resources for the Portuguese Wave Energy Pilot Zone (PZ). Offshore wind conditions are computed by the mesoscale regional atmospheric model MM5 whose good accuracy for that area had already been assessed through comparison against data. Wave conditions were produced by the shallow-water wind-wave model SWAN using as forcing wind the fields produced by MM5 and initial and boundary wave conditions computed the 3rd generation wind-wave model MAR3G. These preliminary results for the PZ were compared against buoy data for a two-month period. It was found that the accuracy is reasonable for significant wave height, wave power and mean direction but the energy period and peak period were significantly under-calculated. It is planned to further develop this work using initial and boundary conditions produced by a different wind-wave model as well as different SWAN parameterization models for wave generation and white-capping.
To Degrade or Not to Degrade
Authors: Hurtley Stella M.
Published: February 2010

In vivo protein stoichiometries are regulated through N-terminally acetylated degrons.
Notch-like Neurotrophin Receptor
Authors: Ray L. Bryan
Published: February 2010

A fragment of the p75 neurotrophin receptor appears to regulate transcription in the nucleus.
Science Signaling
Podcast: 23 February 2010
Authors: Li Chuan-Yuan , VanHook Annalisa M.
Published: February 2010

Dying cells release signals that stimulate cellular proliferation in regenerating tissues.
ER Stress in Pancreatic β Cells: The Thin Red Line Between Adaptation and Failure
Authors: Eizirik Decio L. , Cnop Miriam
Published: February 2010

The response of IRE1α to metabolic ER stress is modulated by its interaction with RACK1.
CCR7 Deficiency Leads to Leukocyte Activation and Increased Clearance in Response to Pulmonary
Pseudomonas aeruginosa
Infection
Authors: Eppert Bryan L. , Motz Gregory T. , Wortham Brian W. , Flury Jennifer L. , Borchers Michael T.
Published: February 2010

CCR7 is a chemokine receptor expressed on the surfaces of T cells, B cells, and mature dendritic cells that controls cell migration in response to the cognate ligands CCL19 and CCL21. CCR7 is critical for the generation of an adaptive T cell response. However, the roles of CCR7 in the host defense against pulmonary infection and innate immunity are not well understood. We investigated the role of CCR7 in the host defense against acute pulmonary infection with
Pseudomonas aeruginosa
. We intranasally infected C57BL/6 mice with
P. aeruginosa
and characterized the expression of CCR7 ligands and the surface expression of CCR7 on pulmonary leukocytes. In response to infection, expression of CCL19 and expression of CCL21 were oppositely regulated, and myeloid dendritic cells upregulated CCR7 expression. We further examined the effects of CCR7 deficiency on the inflammatory response to
P. aeruginosa
infection. We infected
Ccr7
−/−
and wild-type mice with
P. aeruginosa
and characterized the accumulation of pulmonary leukocytes, production of proinflammatory mediators, neutrophil activation, and bacterial clearance. CCR7 deficiency led to an accumulation of myeloid dendritic cells and T cells in the lung in response to infection. CCR7 deficiency resulted in higher expression of CD80 and CD86 on dendritic cells; increased production of interleukin-12/23p40 (IL-12/23p40), gamma interferon (IFN-γ), and IL-1α; increased neutrophil respiratory burst; and, ultimately, increased clearance of acute
P. aeruginosa
infection. In conclusion, our results suggest that CCR7 deficiency results in a heightened proinflammatory environment in response to acute pulmonary
P. aeruginosa
infection and contributes to more efficient clearance.
TheRickettsia conoriiAutotransporter Protein Sca1 Promotes Adherence to Nonphagocytic Mammalian Cells
Authors: Riley Sean P. , Goh Kenneth C. , Hermanas Timothy M. , Cardwell Marissa M. , Chan Yvonne G. Y. , Martinez Juan J.
Published: February 2010

The pathogenesis of spotted fever group (SFG)Rickettsiaspecies, includingR. conoriiandR. rickettsii, is acutely dependent on adherence to and invasion of host cells, including cells of the mammalian endothelial system. Bioinformatic analyses of several rickettsia genomes revealed the presence of a cohort of genes designatedscagenes that are predicted to encode proteins with homology to autotransporter proteins of Gram-negative bacteria. Previous work demonstrated that three members of this family, rOmpA (Sca0), Sca2, and rOmpB (Sca5) are involved in the interaction with mammalian cells; however, very little was known about the function of other conserved rickettsial Sca proteins. Here we demonstrate thatsca1, a gene present in nearly all SFG rickettsia genomes, is actively transcribed and expressed inR. conoriicells. Alignment of Sca1 sequences from geographically diverse SFGRickettsiaspecies showed that there are high degrees of sequence identity and conservation of these sequences, suggesting that Sca1 may have a conserved function. Using a heterologous expression system, we demonstrated that production ofR. conoriiSca1 in theEscherichia coliouter membrane is sufficient to mediate attachment to but not invasion of a panel of cultured mammalian epithelial and endothelial cells. Furthermore, preincubation of a recombinant Sca1 peptide with host cells blockedR. conoriicell association. Together, these results demonstrate that attachment to mammalian cells can be uncoupled from the entry process and that Sca1 is involved in the adherence ofR. conoriito host cells.
Characterization of a Novel Murine Model of
Staphylococcus saprophyticus
Urinary Tract Infection Reveals Roles for Ssp and SdrI in Virulence
Authors: Kline Kimberly A. , Ingersoll Molly A. , Nielsen Hailyn V. , Sakinc Türkan , Henriques-Normark Birgitta , Gatermann Sören , Caparon Michael G. , Hultgren Scott J.
Published: February 2010

Staphylococcus saprophyticus
, an obligate human pathogen, is the most common Gram-positive causative agent of urinary tract infection (UTI) in young, healthy women. Despite the clinical importance of
S. saprophyticus
, little is known about how it causes disease in the urinary tract or how the host responds to the infection. Here we established an
in vivo
model to study both host and bacterial factors contributing to
S. saprophyticus
UTI. Using this model, we show that
S. saprophyticus
preferentially infects C3H/HeN murine kidneys instead of the bladder, a trait observed for multiple clinical isolates. Bacterial persistence in the kidneys was observed in C3H/HeN mice but not in C57BL/6 mice, indicating that host factors strongly contribute to the ability of
S. saprophyticus
to cause UTI. Using C3H/HeN mice as a model, histologic and immunofluorescence analyses of infected tissues revealed that
S. saprophyticus
induced epithelial cell shedding in the bladder and an inflammatory response characterized by macrophage and neutrophil infiltration in the bladder and kidneys. The inflammatory response correlated with increased production of proinflammatory cytokines and chemokines in both the bladder and the kidneys. Finally, we observed that the putative
S. saprophyticus
virulence factors Ssp and SdrI were important for persistence, but not for initial colonization, in the murine urinary tract. Thus, we characterized both host and bacterial factors involved in progression of
S. saprophyticus
UTI, and we describe a useful model system for studying factors involved in the pathogenesis of this Gram-positive uropathogen.
Documenting the need for translational research: an example from workplace violence prevention
Authors: Peek-Asa Corinne , Casteel Carri H
Published: February 2010

The leading cause of occupational death in small retail establishments—workplace violence—provides an example of how data can be used to document the need for type 2 translational research. First, strategies effective in reducing workplace violence in small retail businesses were identified. Next, the effectiveness of the researched strategies was compared with the types of strategies voluntarily implemented by small businesses. The strongest evidence-based strategies were the least likely to be implemented by businesses, and the relationship between effectiveness and implementation was nearly inverse. For example, cash control policies were found to be effective in 92% of studies, but fewer than 10% of businesses had implemented adequate cash control policies. Surveillance cameras were found to be effective in only 50% of studies, but more than 70% of businesses had implemented them. In the absence of effective translation of knowledge and practice, business owners installed the least effective strategies, often at a higher cost.
Recent increases in fatal and non-fatal injury among people aged 65 years and over in the USA
Authors: Hu Guoqing , Baker Susan P
Published: February 2010

Objective

To identify recent increases in mortality and morbidity rates from injuries among Americans aged 65 years and over.

Design

A longitudinal analysis of mortality and morbidity data on injuries in the elderly, examining variations in recent trends by cause, sex, race/ethnicity and age group.

Setting

USA, mortality rate (2000–6) and morbidity rate (2001–7).

Data sources

Centers for Disease Control and Prevention's web-based injury statistics query and reporting system online database.

Main outcome measures

Linear regression was used to examine the statistical significance of trends in mortality and morbidity rates in the study period. The percentage change in rates was used to measure the linear trend. Race/ethnicity was classified into Hispanic (all races except black), non-Hispanic white (‘white’) and black.

Results

Injury mortality for people aged 65 years and over increased by 3% during 2000–6; morbidity increased by 7% during 2001–7. Falls mortality increased by 42% but emergency department visits for falls did not increase. Significant increases in death rates occurred in motorcycle crashes (145%), machinery (46%), poisoning (34%) and drowning (19%); morbidity rates increased in poisoning (143%), motorcycle crashes (86%), machinery (48%), bicycles (24%), struck by/against (13%) and overexertion (11%). Motor vehicle occupant injuries decreased.

Conclusions

The reported rate of fatal falls for people aged 65 years and over increased by 42% during 2000–6 but non-fatal falls did not increase. Research is needed to explain the inconsistent changes between fatal and non-fatal falls, and to identify risk factors contributing to the significant increases in both fatal and non-fatal injuries from machinery, motorcycle crashes and unintentional poisoning.
Using virtual reality to train children in safe street-crossing skills
Authors: Schwebel David C , McClure Leslie A
Published: February 2010

Background

Pedestrian injuries are among the leading causes of morbidity and mortality in middle childhood. One limitation to existing pedestrian safety interventions is that they do not provide children with repeated practice needed to develop the complex perceptual and cognitive skills required for safe street crossing. Virtual reality offers training through repeated unsupervised practice without risk, automated feedback on success of crossings, adjustment of traffic to match children's skill and a fun, appealing environment for training.

Objective

To test the efficacy of virtual reality to train child pedestrians in safe street crossing.

Setting

Birmingham, Alabama, USA.

Methods

A randomised controlled trial is underway with an expected sample of four groups of 60 children aged 7–8 years (total N=240). One group receives training in an interactive, immersive virtual pedestrian environment. A second receives pedestrian safety training via widely used video and computer strategies. The third group receives what is judged to be the most efficacious treatment currently available, individualised behavioural training at streetside locations. The fourth group serves as a no-contact control group. All participants are exposed to a range of field and laboratory-based measures of pedestrian skill during baseline and post-intervention visits, as well as during a 6-month follow-up assessment.

Outcome Measures

Primary analyses will be conducted through linear mixed models testing change over time in the four intervention groups. Three pedestrian safety measures will serve as primary outcomes: temporal gap before initiating crossing, temporal gap remaining after crossing and attention to traffic while waiting to cross.

Clinical Trial Registration

This study is registered at the US government website,www.clinicaltrials.gov, under the title ‘Using virtual reality to train children in pedestrian safety’, registration numberNCT00850759.
An alternative method of measuring fertilizer effects in forest stands
Authors: Salonius P. O. , Fisher R. A. , Mahendrappa M. K.
Published: February 2010

In natural stands, variations in growth rates between plots before treatment due to variable stocking, variable population structure, and site differences often preclude the assessment of growth response to fertilizer treatment by conventional plot comparison. An alternative methodology is described, using growth for a black spruce stand in a pretreatment period as the standard against which growth following treatment is compared for each tree. The results of this comparison on treated and control plots are then related to each other to evaluate growth response to fertilizer treatment. Methods for extracting meaningful fertilizer response data are suggested for experiments which are in progress or are completed but not yet harvested.
Relative sensitivity of 18 full-sib families of Pinustaeda to O3
Authors: Kress L. W. , Skelly J. M. , Hinkelmann K. H.
Published: February 2010

Seedlings of 18 full-sib families of loblolly pine (Pinustaeda L.) were screened for sensitivity to 0.10, 0.15, 0.20, or 0.25 ppm O3 in 8-h exposures. Primary needles of newly germinated seedlings and secondary needles of 1-year-old trees were exposed when the needle ages were 3–4 and 8–12 weeks, respectively. Significant variation in foliar symptom expression was noted among families, and was nearly identical for both primary and secondary needles. Family 6-13 × 2-8 was the most sensitive in eight of nine treatments, and was significantly more sensitive than the remaining 17 families in five of nine treatments. In all cases, family 6-13 × 2-8 sustained greater injury than the families involving parent tree 504 (three families) and the difference was significant in eight of nine treatments. The data suggest that it may be feasible to use sensitive and insensitive families of loblolly pine as air pollutant bioindicators, although considerable further development is necessary. The finding that sensitivity and tolerance may be heritable warrants further study.
Water chemistry profiles in an early- and a mid-successional forest in coastal British Columbia
Authors: Binkley Dan , Kimmins J. P. , Feller M. C.
Published: February 2010

Water chemistry profiles of an 18-year-old forest ecosystem are compared with those of a 70- to 90-year-old forest ecosystem for a 9-month period. The younger ecosystem was dominated by Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and red alder (Alnusrubra Bong.) whereas western hemlock (Tsugaheterophylla (Raf.) Sarg.), Douglas-fir, and western red cedar (Thujaplicata Donn.) dominated the older ecosystem. Concentrations of nutrients and other chemicals were measured in throughfall, forest floor and mineral soil lecachates, saturated-zone water, and stream water. Concentrations of dissolved chemicals were much greater in the younger ecosystem than in the older ecosystem at intermediate stages in the profiles. However, stream water concentrations differed less between the two ecosystems for most of the chemicals investigated. Nitrate and silica were exceptional; stream water nitrate concentrations in the younger ecosystem averaged 16 times greater than those in the older ecosystem. This was probably a result of biological nitrogen fixation by red alder in the younger ecosystem, a process which would more than compensate for the higher nitrate losses. Silica concentrations in the younger ecosystem consistently exceeded levels in the older ecosystem by 40 to 100%. suggesting a possibility of a greater rate of mineral weathering in the younger ecosystem.Although nutrient concentrations were higher in the soil leachates of the younger ecosystem, these higher levels failed to persist through the saturated-zone water and stream water stages of the water chemistry profile. Consequently, the younger ecosystem appeared relatively more efficient at retaining dissolved nutrients than the older ecosystem. Stream water chemistry was relatively insensitive to the magnitudes of the differences in biogeochemical process rates of the two ecosystems.
Seedfall in a young-growth Douglas-fir stand: 1950–1978
Authors: Reukema Donald L.
Published: February 2010

A 29-year record of seedfall in thinned and unthinned portions of a Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) stand, spanning ages 39 through 68, reveals annual seed production from no seeds to about 3 million per hectare. For the nine largest crops, annual seedfall in the best seed-producing thinning treatment included at least 100 000 filled seed per hectare. The first of these nine crops was in 1950; the other eight occurred at 1- to 4-year intervals beginning with 1959. For the nine largest crops, the proportion of seeds filled averaged 45% and ranged from 30 to 54%. Typically, about two-thirds of the seed fell by mid-December; but for two of the three largest crops, time of seed shedding was greatly delayed. Thinning substantially increased the number of seeds produced in some years following thinning but the effect was not lasting. There was little or no effect of thinning on the proportion of seed filled or timing of seed dissemination.
Effect of growth regulators, girdling, and mulching on flowering of young European and Japanese larches under field conditions
Authors: Bonnet-Masimbert Marc
Published: February 2010

Two experiments were undertaken in 1977 and 1979 to promote flowering of 5- and 7-ycar-old field-grown seedlings of Larixleptolepis Gord. and L. decidua Mill. A gibbcrellin A4/7 mixture (GA4/7) was applied alone or in combination with GA3 and naphthalene acetic acid (NAA) to both girdled and nongirdled trees or branches by two methods, perfusion into the xylem and spraying with an aqueous cationic surfactant solution. Perfusion was most effective, especially on girdled branches, although spraying was reasonably effective for male flowering in L. decidua. Only GA4/7 alone significantly increased flowering. Male flowering was doubled and female flowering increased eightfold by GA4/7 in the best treatments, over all application dates. Generally, male flowering doubled and female flowering increased eightfold by GA4/7. Even more flowering was obtained at optimal application dates. May and June applications were best, especially for treatments associated with girdling. However, some flowering occurred with applications as late as August and September. More strobili of both sexes develop in the upper crown. However GA4/7 treatment induced seed cone buds to appear in the lower crown, an abnormal location. An unusual effect occurred in that a positive flowering response of the 1977 experiment occurred only in 1979, whereas the 1979 experiment yielded enhanced flowering in 1980. Soil mulching with a plastic film, with or without hormone treatment, was a very effective adjunct treatment for both male and female flowering.
The effect of soil disturbance on growth and ectomycorrhizae of Douglas-fir and western hemlock seedlings: a greenhouse bioassay
Authors: Schoenberger M. Meyer , Perry D. A.
Published: February 2010

In a greenhouse bioassay of soils from the central Oregon Cascades, Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seedlings had the most total and ectomycorrhizal root tips when grown in soil from an unburned clear-cut and the least when grown in soil from (i) a 20-year-old plantation that had been clear-cut and burned in the late 1950's and (ii) one old-growth forest. Tip formation was intermediate in soil from a second old-growth forest, a recently burned clear-cut, and a 40-year-old natural burn. Root weights followed the same trend, but top weights did not differ among the various soils. Ectomycorrhizal and total root tips of western hemlock (Tsugaheterophylla (Raf.) Sarg.) were lowest in soils from the plantation and recently burned clear-cut. Unlike Douglas-fir, western hemlock's tip production was not greater in the unburned clear-cut than in the old-growth forest soils. In this species, both top and root weights varied according to soil, with the largest seedlings produced in soil from the unburned clear-cut. With both species, there was a significant interaction between ectomycorrhizal type and soil type. Cenococcumgeophilum Fr. predominated on western hemlock and was reduced in soils from the burned clear-cut and plantation. In comparison with the mean for all soils, ectomycorrhizal types that predominated on Douglas-fir were enhanced in the unburned clear-cut soil and reduced in one old-growth soil, an effect apparently related to litter leachate.
Adaptations of whitebark pine for seed dispersal by Clark's Nutcracker
Authors: Lanner Ronald M.
Published: February 2010

Whitebark pine (Pinusalbicaulis Engelm.) has large, energy-rich, wingless seeds that are not wind dispersable, and indehiscent cones that retain their matured seeds within. Scales are easily broken off the cone axis, leaving many of the seeds exposed and held in the core of the cone. Cones are sessile on ascending limbs, and therefore conspicuous when viewed from above. These characteristics are adaptations to the foraging activities of Clark's Nutcracker (Nucifragacolumbiana Wilson), which removes seeds from cones and stores them in subsoil caches, thus permitting them to germinate and become established trees. It is hypothesized that speciation of the Cembrae pines has occurred through nutcracker-mediated selection exerted on conventional white pine antecedents.
Effect of cold storage and chemical treatment on rooting of hardwood sycamore cuttings
Authors: Hare Robert C. , Land Jr. Samuel B.
Published: February 2010

About 50% of hardwood sycamore (Platanusoccidentalis L.) cuttings taken in late fall from mature trees rooted after cold storage and chemical treatments. Best results were obtained by treating cutting bases with auxins, a fungicide, and powdered sucrose followed by 1 month of cold storage. Rooting was correlated with vegetative vigor of the ortet. The correlation did not increase when ortet age was included with vigor in the regression equation.
Factors affecting transfer and spread of Phellinusweirii mycelium in roots of second-growth Douglas-fir
Authors: Bloomberg W. J. , Reynolds G.
Published: February 2010

Effects of site, root diameter, soil depth of interroot contact, length of root surface in contact, type of contact, and relative position of roots were investigated on the frequency of transfer of Phellinusweirii (Murr.) Gilbertson mycelium between roots and its spread along roots of second-growth Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco). Successful transfer of P. weirii as ectotrophic or endotrophic mycelium occurred in 32 and 3%, respectively, of total number of interroot contacts. Unsuccessful transfers occurred in 4 and 62%, respectively, with the balance of contacts having undetermined transfers, owing to extension of mycelium to the root collar of both roots in contact. A Pseudotsuga–Polystichum site had a higher frequency of unsuccessful transfer than two Pseudotsuga–Gaultheria sites. Average root diameter was greater and average depth was less in contacts with successful transfers than in those with unsuccessful transfers. Type or length of contact or relative position of roots had no significant effects on transfers. There was a highly significant inverse relationship between root diameter and length of endotrophic mycelial spread as measured by decay column. The regression of endotrophic on ectotrophic mycelial spread along roots was highly significant for both proximal and distal spread. In most roots, ectotrophic mycelium had spread distally to the tip and proximally to the stump, whereas endotrophic mycelium had not.
EXTENDED DISTRIBUTIVE LAW: COWREATH OVER CORINGS
Authors: EL KAOUTIT L.
Published: February 2010

We introduce and study comodules over cowreath defined over a given coring. If our coring arises from an entwining structure, we then give a procedure to construct a cowreath from a given cowreath over the factor coalgebra. We also include the dual notions, that is, wreaths over ring extension and their modules. In particular, we show that the study of twisted algebras and twisted bimodules already introduced in [A. Čap, H. Schichl and J. Vanžura, On twisted tensor products of algebras, Commun. Algebra23 (1995) 4701–4735] has its origin in the study of wreath and their bimodules.
HOPF ALGEBRAS OF DIMENSION 30
Authors: FUKUDA DAIJIRO
Published: February 2010

This paper contributes to the classification of finite dimensional Hopf algebras. It is shown that every Hopf algebra of dimension 30 over an algebraically closed field of characteristic zero is semisimple and thus isomorphic to a group algebra or the dual of a group algebra.
Impressionism, expressionism, surrealism
Authors: Shamir Lior , Macura Tomasz , Orlov Nikita , Eckley D. Mark , Goldberg Ilya G.
Published: February 2010

We describe a method for automated recognition of painters and schools of art based on their signature styles and studied the computer-based perception of visual art. Paintings of nine artists, representing three different schools of art—impressionism, surrealism and abstract expressionism—were analyzed using a large set of image features and image transforms. The computed image descriptors were assessed using Fisher scores, and the most informative features were used for the classification and similarity measurements of paintings, painters, and schools of art. Experimental results show that the classification accuracy when classifying paintings into nine painter classes is 77%, and the accuracy of associating a given painting with its school of art is 91%. An interesting feature of the proposed method is its ability to automatically associate different artists that share the same school of art in an unsupervised fashion. The source code used for the image classification and image similarity described in this article is available for free download.
Queuing theoretic model for a multiprocessor with private caches and shared memory
Authors: Nikolov Angel V.
Published: February 2010

We develop an analytical model of multiprocessor with private caches and shared memory and obtain the steady-state probabilities of the system. Behaviour in equilibrium can be studied and analyzed. We show that results can be applied to determine the output parameters for both blocking and non-blocking caches.
Bioelectrocatalysis of Pyruvate with PQQ-dependent Pyruvate Dehydrogenase
Authors: Treu Becky L. , Sokic-Lazic Daria , Minteer Shelley
Published: February 2010

Although pyruvate has not been considered as a fuel for an enzymatic biofuel cell, there are dehydrogenase enzyme capable of oxidizing pyruvate. This paper details the discovery of a pyrroloquinoline quinone-dependent pyruvate dehydrogenase (PQQ-PDH) in Gluconobacter species. A method was developed to isolate and purify PQQ-PDH from Gluconobacter, along with the characterization of the purified enzyme. It was found that the purified enzyme can undergo direct electron transfer at carbon electrodes surfaces, which allowed for its incorporation into a pyruvate biofuel cell. It was also found that PQQ-PDH lacks substrate specificity, which minimizes its usefulness in many sensor applications, but is advantageous for deep oxidation in biofuel cell anodes.