bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamics of the Southern Hemisphere Spiral Jet
Authors: Williams Lindsey N. , Lee Sukyoung , Son Seok-Woo 
Published: February 2007

Abstract
The formation of the Southern Hemisphere spiral jet is investigated using observations over a 40-yr period. It is found that between late March and early April, the upper-tropospheric westerly jet in the Southern Hemisphere undergoes a transition from an annular structure in midlatitudes to a spiral structure that extends from 20° to 55°S. The transition to the spiral structure is initiated by the formation of a subtropical jet, localized in the central Pacific. The inception of the jet spiral is completed with the formation of a band of northwest-to-southeast-oriented zonal winds, which is connected to both the subtropical and the polar-front jets. This band, referred to as the tilting branch, arises from momentum flux convergence associated with breaking Rossby waves. As such, the direction of the wave breaking determines the direction of the jet spiral; an anticyclonic wave breaking, associated with equatorward wave dispersion, establishes a jet spiral that turns cyclonically toward the pole.
This formation mechanism of the jet spiral is supported by a set of calculations with an idealized numerical model. These model calculations indicate that the jet spiral is obtained only if the model’s localized subtropical jet is sufficiently strong, and if the latitude of the polar-front jet is sufficiently higher than that of the subtropical jet. The calculations also indicate that the spiral jet is a transient solution, implying that the lack of spiral structure during the austral winter may be caused by the zonal wind field reaching a new statistically steady state.
Metadata from WMO Publication No. 47 and an Assessment of Voluntary Observing Ship Observation Heights in ICOADS
Authors: Kent Elizabeth C. , Woodruff Scott D. , Berry David I. 
Published: February 2007

Abstract
It is increasingly recognized that metadata can significantly improve the quality of scientific analyses and that the availability of metadata is particularly important for the study of climate variability. The International Comprehensive Ocean–Atmosphere Data Set (ICOADS) contains in situ observations frequently used in climate studies, and this paper describes the ship metadata that are available to complement ICOADS. This paper highlights the metadata available in World Meteorological Organization Publication No. 47 that include information on measurement methods and observation heights. Changing measurement methods and heights are known to be a cause of spurious change in the climate record. Here the authors focus on identifying measurement heights for air temperature and wind speed and also give information on SST measurement depths.
An Improved QC Process for Temperature in the Daily Cooperative Weather Observations
Authors: Hubbard Kenneth G. , Guttman Nathaniel B. , You Jinsheng , Chen Zhirong 
Published: February 2007

Abstract
TempVal is a spatial component of data quality assurance algorithms applied by the National Climatic Data Center (NCDC), and it has been used operationally for about 4 yr. A spatial regression test (SRT) approach was developed at the regional climate centers for climate data quality assurance and was found to be superior to currently used quality control (QC) procedures for the daily maximum and minimum air temperature. The performance of the spatial quality assessment procedures has been evaluated by assessing the rate with which seeded errors are identified. A complete dataset with seeded errors for the year 2003 for the contiguous United States was examined for both the maximum and minimum air temperature. The spatial regression quality assessment component (SRT), originating in the Automated Climate Information System (ACIS), and TempVal, originating in the NCDC database, were applied separately and evaluated through the ratio of identified seeded errors to the total number of seeds. The spatial regression test applied in the ACIS system was found to perform better in identifying the seeded errors. For all months, the relative frequency of correct identification of wrong data is 0.72 and 0.83 for TempVal and SRT, respectively. The goal of the comparison was to evaluate quality assurance techniques that could improve data quality assessment at the NCDC, and the results of the comparison led to the recommendation that the SRT be included in the NCDC quality assessment methodology.
High-Resolution Measurement of Size Distributions of Asian Dust Using a Coulter Multisizer
Authors: Kobayashi Hiroshi , Arao Kimio , Murayama Toshiyuki , Iokibe Kengo , Koga Ryuji , Shiobara Masataka 
Published: February 2007

Abstract
A Coulter Multisizer, which is based on the electrical sensing zone (ESZ) or the Coulter principle, was used to measure the size distribution of Asian dust. Coulter Multisizer analysis provides high-resolution size measurements of water-insoluble aerosol particles (WIPs) and the number concentration at each size bin. Aerosol filter sampling was conducted at four sites in Japan during spring 2003. The measured volume size distributions fit fairly well with a lognormal distribution. The results show that the WIP size distributions of the same Asian dust air mass varied at each sampling site and the volume mode diameter at the sites reduced from west to east. The derived volume mode diameter ranged from 1.4 to 2.2 μm and was comparatively smaller than those in previous studies on Asian dust. This can be explained by the possible internal mixing of Asian dust with other components and by the breaking of particles and dispersion of aggregations by ultrasonification during extraction. The analysis method was improved by washing the aerosol particles collected on a filter using a magnetic stirrer, instead of an ultrasonic cleaner. As a result, the WIP size distribution can be measured in the range of 1–10 μm. The measured mode diameters were 2.6–3.1 and 4.3–5.6 μm in 2 Asian dust phenomena at Kofu, Japan, in 2004. It is demonstrated that the Coulter Multisizer method can furnish detailed information regarding the spatial and temporal variations in the mineral dust size distribution.
Estimation of Water Temperature of Large Lakes in Cold Climate Regions during the Period of Strong Coupling between Water and Air Temperature Fluctuations
Authors: Bussières Normand , Granger Raoul J. 
Published: February 2007

Abstract
Near-surface bulk water temperature measured in large northern lakes during the warm season with buoys can be characterized by three components: a slowly varying seasonal-/climate-related trend, fluctuations at the time scale of weather perturbations, and rapid daily fluctuations. When thermal infrared data are used to estimate surface water temperature, an additional term relating the differences between the skin and bulk temperatures is implied. Buoy data in this work serve to demonstrate the existence of a period of strong signal coupling between fluctuations of water temperature and air temperature. The period of strong signal coupling does not extend beyond the date of maximum temperature in the water temperature trend. During this period, a simple linear transformation of air temperature fluctuations can be used to simulate the buoy water temperature fluctuations. Attempts to simulate water temperature fluctuations from air temperature alone are not possible beyond this period. Water temperature simulation error depends on the distance of the air temperature measurement from the buoy, ranging from ±1.1°C at 0 km to ±1.4°C at 40 km. The method developed with buoy data is applied to the combination of satellite thermal infrared and operationally measured air temperature data to simulate water temperatures. Through the use of satellite data, the water temperature simulations are extended beyond the period of strong coupling.
Patterns and rates of intron divergence between humans and chimpanzees
Authors: Gazave Elodie , Marqués-Bonet Tomàs , Fernando Olga , Charlesworth Brian , Navarro Arcadi 
Published: February 2007

Abstract
Background
Introns, which constitute the largest fraction of eukaryotic genes and which had been considered to be neutral sequences, are increasingly acknowledged as having important functions. Several studies have investigated levels of evolutionary constraint along introns and across classes of introns of different length and location within genes. However, thus far these studies have yielded contradictory results.

Results
We present the first analysis of human-chimpanzee intron divergence, in which differences in the number of substitutions per intronic site (Ki) can be interpreted as the footprint of different intensities and directions of the pressures of natural selection. Our main findings are as follows: there was a strong positive correlation between intron length and divergence; there was a strong negative correlation between intron length and GC content; and divergence rates vary along introns and depending on their ordinal position within genes (for instance, first introns are more GC rich, longer and more divergent, and divergence is lower at the 3' and 5' ends of all types of introns).

Conclusion
We show that the higher divergence of first introns is related to their larger size. Also, the lower divergence of short introns suggests that they may harbor a relatively greater proportion of regulatory elements than long introns. Moreover, our results are consistent with the presence of functionally relevant sequences near the 5' and 3' ends of introns. Finally, our findings suggest that other parts of introns may also be under selective constraints.
The Fracture of Femoral Components — An Act of God?
Authors: Dobbs H S 
Published: February 2007

In previous work a probability model for the fracture of femoral components was presented. This model was based on the assumption that the components were defect-free and that they fractured by a process involving metal fatigue. The model predicted the probability of fracture as a function of the patient's body weight and as a function of the time elapsed since operation (Dobbs, 1977). The present work is an extension of the model taking into account the patient's age and decreasing activity. It predicts the time dependence of the incidence of fracture and of the conditional failure rate. These predictions are compared with recently published survey data tending to support the view that the fracture of these components is a wearing-out process.
A Miniature Swashplate Water Pump for Powered Prostheses
Authors: McIntyre A W , Needham G A , McLeish R D 
Published: February 2007

A miniature swashplate pump is described with a unique performance, as far as the authors are aware, delivering 1.5 ml/s of water at a pressure of 34 bar; the complete motor, gearbox and pump assembly weighing 315 gm and measuring 42 mm diameter by 108 mm long. An efficiency, electrical to fluid, of 61 per cent has been achieved under normal operating conditions, the pump mechanical efficiency being 78 per cent. A synopsis of the pump development is included with details of the current design. Although this pump has been designed specifically for use in a hydraulically powered artificial arm system, with suitable modification it could be used in any application requiring a high pressure, low flow rate fluid delivery.
Analysis of Parameters Affecting Impact Force Attenuation during Landing in Human Vertical Free Fall
Authors: Mizrahi J , Susak Z 
Published: February 2007

The characteristics of impact forces on the legs during vertical landing of human vertical free fall in different falling conditions were studied to reveal the parameters which take part in the attenuation of these impact forces. The following parameters were investigated: body position during landing, range of flexion of the joints of the legs at impact, usage of ground-roll immediately after impact and softness of the ground. The results indicate that joint movements and muscle action play a major role in reducing peak forces during landing. This emphasizes the importance of adequate training to improve the pre-programmed non-reflex muscle action, necessary in the early phase of impact.
Biomechanical Design of the Total Ankle Prosthesis
Authors: Calderale P M , Garro A , Barbiero R , Fasolio G , Pipino F 
Published: February 2007

The load bearing joints of the human body and particularly the ankle are often seriously damaged because of different pathological events. During the last 10 years a lot of total ankle prostheses have been studied and implanted, in consequence of the inadequate results obtained by arthrodesis (i.e. the fusion of the joint). The aim of this paper is to analyze mechanical features (functional, kinematic, and strength) of the ankle joint in order to provide optimized design criteria of an arthroprosthesis substituting the disabled joint.
Ground Reaction Forces during Human Standing
Authors: Shimba Takeshi 
Published: February 2007

Foundamental characteristics of ground reaction forces measured by using a force plate during human standing were investigated. Force fluctuation levels and power spectrums of the force data for standing posture were compared with those for sitting. The force fluctuation levels in the horizontal plane and their time varying characteristics were evaluated by using an index of short time interval variance (SIV). Three curves, denoted by A, E, and G, approximating change with time of the centre of gravity of the body were calculated from the force data and traces of these curves were compared. The fluctuation levels of forces in relaxed standing were not so high as those during sitting. The value of SIV and its mid-mean value for each measured data appeared to be useful to represent the force fluctuation level in the standing posture. The curves A, E, and G were well fitted as a whole and each of them can be estimated, more or less, an approximation of the true curve of centre of gravity unless the body movement is not so vigorous.
The Load Bearing Capacity of Vertebral Cancellous Bone in Interbody Fusion of the Lumbar Spine
Authors: Pearcy M J , Evans J H , O'Brien J P 
Published: February 2007

Interbody fusion involves the grafting of bone between the vertebral bodies themselves. The bone graft is considered to be load bearing post-operatively, and it is necessary to know how large the transverse sectional area of the graft should be in order to sustain the loads on the spine, post-operatively, before bony union is attained. The cancellous bone of the vertebral bodies has previously been shown to be the weakest element of the grafted spinal segment and a series of compression tests on cadaveric material was undertaken in order to determine the size of graft required to distribute the compressive loads so as not to exceed the failure strength of the vertebral bone. The results suggest that at least 0.4 of the transverse sectional area of the vertebral bodies should be covered by the graft for the fused segment to sustain axial loading post-operation. Local trabecular fracture due to incongruency of the graft/vertebra surfaces and slight movements at the grafted joint is proposed as a mechanical reason for delayed union.
Biomedical Engineering Teaching and Research at the Centre for Biomedical Engineering, University of new South Wales, Kensington, Australia
Authors: Farrell P C , Flicker W , Svensson N L 
Published: February 2007

The Centre for Biomedical Engineering is a postgraduate facility which is unique within Australia in terms of the breadth of its research activities. The postgraduate training of biomedical engineering professionals is a major objective of the Centre's programme; training and research is provided not only for graduates with engineering backgrounds, but also for those with medical, biological, and physical sciences background. The output of Masters and PhD graduates is approximately 15 per annum. Predominant research areas are in the mathematical modelling of medical treatment such as optimization of artificial kidney and plasma exchange therapies, application of microprocessors and computers to medical problems, investigation of respiratory and cardiovascular dynamics, and improvement of orthopaedic implants. Studies in rehabilitation engineering, biomechanics, hormonal control systems, and neurophysiological modelling are conducted in associated departments.
Design, Development, and Clinical Trial of a Modular Elbow Replacement Incorporating Cement-Free Fixation
Authors: Amis A A , Miller J H 
Published: February 2007

This paper describes the design process leading to a total elbow replacement with components which have an accurate anatomical shape and require minimal bone resection. This allows a ‘modular’ approach to elbow reconstruction, i.e., radial head replacement alone, humeral hemiarthroplasty, humero-radial or ulnar replacement, or total (three component) reconstruction. This approach means that the surgeon may choose to replace only the damaged joint surfaces, rather than being committed to total replacement. The parallel development of instruments for accurate bone forming is also described, allowing firm and precise fixation of prosthetic components without bone cement, a necessity for interlocking bone ingrowth to occur without extended immobilization. A clinical trial of these components, in more than fifty patients for periods up to five years, is reviewed, showing the restoration of pain-free stability and greater ranges of motion than have been reported for other elbow replacement devices, and with no incidence of prosthetic removal caused by painful loosening.
Porous Titanium Dental Implants in Primates and Humans
Authors: Young F A , Keller J C 
Published: February 2007

A series of 30 cylindrical implants employing sintered powder metal exteriors to promote bone ingrowth have been employed to support bridges and crowns in Rhesus monkeys for periods exceeding 36 months. Clinical indicators demonstrated successful function during the period of the experiments for 24 of the 30 implants. The four implants which did not perform well clinically were analysed by histology and found to be locally infected. Implants retrieved at various times after function were analysed by histomorphometric techniques. In all successful implants bone had grown into the porous exterior of the implant and was found to be supporting the loads of mastication. Long term bone remodeling under stress was evaluated quantitatively. It was found that for periods of function exceeding three years, remodeling which was not present in one and two year specimens was detectable. Clinical success was attributed to stabilization accomplished by the bone ingrowth. Clinical and histological results were analysed using a computerized data handling system, and correlations between histology and clinical performance were attempted. In human experiments eight patients have received implants which will support bridges used as distal extensions in the mandible. At this writing, the results are short term and comparison with the animal experiments difficult.
Simulation of Tendon Transfer Surgery
Authors: Dul J , Shiavi R , Green N E 
Published: February 2007

A biomechanical model is used to simulate a tendon transfer operation. The model predicts the required forces in twelve ankle muscles during standing and walking, and also the endurance time of the (instantaneous) posture. In particular, the mechanical effect of anterior transfer of the posterior tibial tendon of a patient with muscle paralysis due to peroneal nerve injury is studied. The results show that before surgery the patient can stand normally but cannot walk normally. Normal walking is mechanically not possible because the required muscle forces in early stance cannot be produced, although the necessary forces can be realized during the remainder of stance. After surgery, both normal standing and normal walking are mechanically possible. The cost is higher forces and shorter endurance times in the healthy muscles. The results agree with clinical findings.
Material Properties of Cancellous Bone in Repetitive Axial Loading
Authors: Linde Frank , Hvid Ivan , Jensen Niels Chr. 
Published: February 2007

Machined cancellous bone specimens from human cadaver knees were tested under repetitive nondestructive axial compression. Loads were applied up to 50 per cent of the ultimate strength of the specimens predicted from their mineral content measured by photon absorption technique. The stiffness increased greatly between the first two compressions, and thereafter asymptotically approached a constant level. There was a 44 per cent median increase in the modulus of elasticity from compression No. 1 to compression No. 10. Steady state was apparently reached after the fifth compression with intervals between compression cycles of not more than 2 minutes. The results were reproducible, and the precision of the modulus of elasticity determined by double measurement at compression No. 10 was Ē ± 9.8 per cent (95 per cent confidence limits). The modulus of elasticity at steady state determined as the mean of compressions 6–10 was found to be Ē ± 5.6 per cent (95 per cent confidence limits). With both methods there was a strong linear correlation between the ultimate strength and the modulus of elasticity. The correlation coefficient was r = 0.95 ( p < 0.005) and r = 0.99 ( p < 0.001), respectively. Due to the calculation error the figures for ultimate stress (US) in Table 2 and Fig. 4, and ultimate stress derived from the regression equations in Table 3 are reduced by a factor of two. The present technique allows studies of viscous properties without engaging in otherwise time-demanding creep studies; yet in order to approach the issue quantitatively, the technical arrangement must be more meticulously prepared. Studies of viscous properties may, however, be of importance to evaluate the damping effect of cancellous bone and its role in the musculo-skeletal damping system.
Some Gait Characteristics of Below-Knee Amputees and Their Reflection on the Ground Reaction Forces
Authors: Seliktar R , Mizrahi J 
Published: February 2007

Human locomotion studies employing cinematography and force plates have been conducted during the last five decades with the goal of producing a clinically acceptable gait evaluation technique. The bulk of information contained in the kinetic studies was the major obstacle in achieving this goal. Our aim in this work was to explore the possibility of representing some locomotor abnormalities solely by their reflection on the ground reaction force characteristics. As a first stage towards the establishment of these relationships, the gait characteristics of below-knee amputees were examined. One hundred and thirty ground force test results as obtained on twenty three below-knee amputees were analysed. Different variables such as time durations of the various phases, peak forces, impulses, rate of change of the forces, and others, were examined. The conclusions suggest that some of these variables are suitable for evaluation of gait and some, such as small perturbations superimposed on the curve, may serve as indicators of specific malfunction of the prosthetic system.
Load Bearing Capacity in Total Ankle Joint Replacement
Authors: Jensen N C , Hvid I 
Published: February 2007

The influence of some simple design variations on the compressive load bearing capacity of tibial and talar prosthetic components in total ankle joint replacement were investigated in an attempt to suggest improvements to current prosthetic designs. Eighteen paired ankle joint preparations were fitted with three types of tibial components and two types of talar components. The tibial component with an intramedullary peg tolerated significantly higher loads before mechanical failure than the two other designs that were equal in load bearing capacity. The mean value of ultimate force was 40 per cent higher and the mean value of yield force was 15 per cent higher. However, for the coefficient of stiffness there was a significant fall of 18 per cent in the mean value. The talar components were equal in load bearing capacity and stiffness.