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Kinds of Strides Terms modified by Strides Selected AbstractsProximity to the US,Mexico border: a key to explaining geographic variation in US methamphetamine, cocaine and heroin purityADDICTION, Issue 10 2010James K. Cunningham ABSTRACT Aims Although illicit drug purity is a widely discussed health risk, research explaining its geographic variation within a country is rare. This study examines whether proximity to the US,Mexico border, the United States' primary drug import portal, is associated with geographic variation in US methamphetamine, heroin and cocaine purity. Design Distances (proximity) between the US,Mexico border and locations of methamphetamine, cocaine and heroin seizures/acquisitions (n = 239 070) recorded in STRIDE (System to Retrieve Information from Drug Evidence) were calculated for the period of 1990,2004. The association of drug purity with these distances and other variables, including time and seizure/acquisition size, was examined using hierarchical multivariate linear modeling (HMLM). Setting Coterminous United States. Findings Methamphetamine, cocaine and heroin purity generally decreased with distance from the US,Mexico border. Heroin purity, however, after initially declining with distance, turned upwards,a U-shaped association. During 2000,04, methamphetamine purity also had a U-shaped association with distance. For each of the three drugs, temporal changes in the purity of small acquisitions (<10 g) were typically more dynamic in areas closer to the US,Mexico border. Conclusions Geographic variance in methamphetamine, cocaine and heroin purity throughout the coterminous United States was associated with US,Mexico border proximity. The U-shaped associations between border-distance and purity for heroin and methamphetamine may be due to imports of those drugs via the eastern United States and southeast Canada, respectively. That said, areas closer to the US,Mexico border generally had relatively high illicit drug purity, as well as more dynamic change in the purity of small (,retail level') drug amounts. [source] Attention deficits, Attention-Deficit Hyperactivity Disorder, and intellectual disabilitiesDEVELOPMENTAL DISABILITIES RESEARCH REVIEW, Issue 4 2008Curtis K. Deutsch Abstract Attention-Deficit Hyperactivity Disorder (ADHD) and its earlier nosologic classifications have been extensively investigated since the 1960s, with PubMed listings alone exceeding 13,000 entries. Strides have been made in the diagnosis and treatment of ADHD in individuals with intellectual function in the normal range, as described in companion reviews in this special issue. In contrast, comparatively little is known about ADHD in intellectual developmental disabilities (IDD) despite the possibility that ADHD is statistically overrepresented among individuals with IDD (Pearson et al. 1997 Attention-deficit/hyperactivity disorder in mental retardation: nature of attention deficits. In: Burack J, Enns J, editors. Attention, development, and psychopathology. New York: Guilford Press. p 205,229; Pearson et al. 2000 Am. J. Ment. Retard. 105:236,251). Here, we provide a review of diagnostic controversies in ADHD with IDD, and discuss several topics that are currently attracting research efforts in the field. These include behavioral phenotyping and attempts to come to grips with problems of behavioral and etiological heterogeneity. Additionally, we consider issues relating to methodologically sound assessment of attention disorders and evidence-based intervention procedures that may clarify and/or ameliorate attention deficits in individuals with IDD. © 2008 Wiley-Liss, Inc. Dev Disabil Res Rev 2008;14:285,292. [source] The effect of rising and sitting trot on back movements and head-neck position of the horseEQUINE VETERINARY JOURNAL, Issue 5 2009P. de COCQ Summary Reason for performing study: During trot, the rider can either rise from the saddle during every stride or remain seated. Rising trot is used frequently because it is widely assumed that it decreases the loading of the equine back. This has, however, not been demonstrated in an objective study. Objective: To determine the effects of rising and sitting trot on the movements of the horse. Hypothesis: Sitting trot has more extending effect on the horse's back than rising trot and also results in a higher head and neck position. Methods: Twelve horses and one rider were used. Kinematic data were captured at trot during over ground locomotion under 3 conditions: unloaded, rising trot and sitting trot. Back movements were calculated using a previously described method with a correction for trunk position. Head-neck position was expressed as extension and flexion of C1, C3 and C6, and vertical displacement of C1 and the bit. Results: Sitting trot had an overall extending effect on the back of horses when compared to the unloaded situation. In rising trot: the maximal flexion of the back was similar to the unloaded situation, while the maximal extension was similar to sitting trot; lateral bending of the back was larger than during the unloaded situation and sitting trot; and the horses held their heads lower than in the other conditions. The angle of C6 was more flexed in rising than in sitting trot. Conclusions and clinical relevance: The back movement during rising trot showed characteristics of both sitting trot and the unloaded condition. As the same maximal extension of the back is reached during rising and sitting trot, there is no reason to believe that rising trot was less challenging for the back. [source] Effects of 6° elevation of the heels on 3D kinematics of the distal portion of the forelimb in the walking horseEQUINE VETERINARY JOURNAL, Issue 8 2004H. CHATEAU Summary Reasons for performing study: Understanding of the biomechanical effects of heel elevation remains incomplete because in vivo studies performed with skin markers do not measure the actual movements of the 3 digital joints. Objective: To quantify the effects of 6° heel wedge on the 3-dimensional movements of the 4 distal segments of the forelimb in the walking horse. Methods: Four healthy horses were used. Kinematics of the distal segments was measured invasively with a system based on ultrasonic triangulation. Three-dimensional rotations of the digital joints were calculated by use of a ,joint coordinate system' (JCS). Data obtained with heel wedges were compared to those obtained with standard shoes during the stance phase of the stride. Results: Heel wedges significantly increased maximal flexion of the proximal (PIPJ) and distal (DIPJ) interphalangeal joints and maximal extension (mean ± s.d. +0.8 ± 0.3°) of the metacarpophalangeal joint (MPJ). Extension of the PIPJ and DIPJ was decreased at heel-off. Few effects were observed in extrasagittal planes of movement. Conclusions: Heel wedges affect the sagittal plane kinematics of the 3 digital joints. Potential relevance: Controversial effects previously observed on the MPJ may be explained by the substantial involvement of the PIPJ, which was wrongly neglected in previous studies performed on the moving horse. [source] Autonomic assessment in Parkinson's disease: a measured stride forwardEUROPEAN JOURNAL OF NEUROLOGY, Issue 2 2010W. P. Cheshire No abstract is available for this article. [source] A fearful child attends: a psychoanalytic explanation of children's responses to dental treatmentINTERNATIONAL JOURNAL OF PAEDIATRIC DENTISTRY, Issue 6 2007RUTH FREEMAN Background., At the mention of dental treatment some children become overwhelmed by anxiety whereas others appear to take the news in their stride. Sometimes when anxious children attend dental treatment, they appear to cope, contain their fears, and passively submit to treatment, whereas others angrily refuse to open their mouths and a third group of children exist who seem to just ,tough it out' no matter how disagreeable or frightening dental treatment becomes. The question remains: why do children react so differently to dental treatment? Aim., This paper aims to provide a psychoanalytic explanation as to why children react and respond differently to dental treatment. Results., This paper proposes a psychoanalytic formulation based on the functionality of the family, parent,child dyads, child psychological development, and the child's emotional and actual life experiences. Conclusions., There is a need to understand the dynamic nature of child dental anxiety and to appreciate the hidden factors and underlying complexities associated with the anxious child who attends for dental treatment. [source] Estimating Cardiorespiratory Fitness in Well-Functioning Older Adults: Treadmill Validation of the Long Distance Corridor WalkJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 1 2006Eleanor M. Simonsick PhD Objectives: To determine criterion validity of the 400-m walk component of the Long Distance Corridor Walk (LDCW) and develop equations for estimating peak oxygen consumption (VO2) from 400-m time and factors intrinsic to test performance (e.g., heart rate (HR) and systolic blood pressure (SBP) response) in older adults. Design: Cross-sectional validation study. Setting: Gerontology Research Center, National Institute on Aging, Baltimore, Maryland. Participants: Healthy volunteers (56 men and 46 women) aged 60 to 91 participating in the Baltimore Longitudinal Study of Aging between August 1999 and July 2000. Measurements: The LDCW, consisting of a 2-minute walk followed immediately by a 400-m walk "done as quickly as possible" over a 20-m course was administered the day after maximal treadmill testing. HR and SBP were measured before testing and at the end of the 400-m walk. Weight, height, activity level, perceived effort, and stride length were also acquired. Results: Peak VO2 ranged from 12.2 to 31.1 mL oxygen/kg per minute, and 400-m time ranged from 2 minutes 52 seconds to 6 minutes 18 seconds. Correlation between 400-m time and peak VO2 was ,0.79. The estimating equation from linear regression included 400-m time (partial coefficient of determination (R2)=0.625), long versus short stride (partial R2=0.090), ending SBP (partial R2=0.019), and a correction factor for fast 400-m time (<240 seconds; partial R2=0.020) and explained 75.5% of the variance in peak VO2 (correlation coefficient=0.87). Conclusion: A 400-m walk performed as part of the LDCW provides a valid estimate of peak VO2 in older adults. Incorporating low-cost, safe assessments of fitness in clinical and research settings can identify early evidence of physical decline and individuals who may benefit from therapeutic interventions. [source] Towards automation of palynology 2: the use of texture measures and neural network analysis for automated identification of optical images of pollen grains,JOURNAL OF QUATERNARY SCIENCE, Issue 8 2004P. LI Abstract The automation of palynology (the identification and counting of pollen grains and spores) will be a small step for image recognition, but a giant stride for palynology. Here we show the first successful automated identification, with 100% accuracy, of a realistic number of taxa. The technique used involves a neural network classifier applied to surface texture data from light microscope images. A further significance of the technique is that it could be adapted for the identification of a wide range of biological objects, both microscopic and macroscopic. Copyright © 2004 John Wiley & Sons, Ltd. [source] AUTOMIC FAILURE AND NORMAL PRESSURE HYDROCEPHALUS IN A PATIENT WITH CHRONIC DEMYELINATING INFLAMMATORY NEUROPATHYJOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 1 2002M. Laurŕ A 75-year-old man with HCV hepatitis developed at the age of 70 presented with rest and action tremor localized at both hands and progressive cognitive impairment with memory loss. Four years later he begun to complain of progressive fatigue, occasional falls, numbness at the extremities and orthostatic hypotension. One month after admission, he rapidly worsened with inability to walk, mainly because of autonomic failure. Neurological examination revealed gait disturbances, including a wide base of support and short stride, slurred speech, reduction of upward gaze, rest and action tremor at both hands, intrinsic hand muscle and anterior tibialis muscle wasting and weakness on both sides, absent deep tendon reflexes, loss of vibration sense at lower limbs, and bilateral pes cavus. Routine laboratory studies, autoantibodies, thyroid function, neoplastic markers and immunoelectrophoresis were normal. Cryoglobulins were absent, whereas CSF protein content was increased (142 mg/dl). Autonomic nervous system investigation detected severe orthostatic hypotension. Nerve conduction studies showed absent sensory potentials and a marked reduction of compound motor action potential amplitudes and of motor conduction velocities. A sural nerve biopsy revealed remarkable onion bulb-like changes, endoneurial and perivascular infiltrations of inflammatory cells. Psychometric tests showed mild cognitive impairment. Brain MRI was consistent with normotensive hydrocephalus. The findings indicated the presence of chronic inflammatory demyelinating polyneuropathy, autonomic nervous system involvement and normal pressure hydrocephalus. A condition of multiple system atrophy (MSA) might be taken into account, even if somatic peripheral nerve involvement may rarely occur in MSA. Moreover the normal pressure hydrocephalus could be due to the high protein content in CSF (Fukatsu R et al., 1997). [source] Kinematic study of whole body center of mass position during gait in Parkinson's disease patients with and without festination,MOVEMENT DISORDERS, Issue 6 2010Marcelo Merello MD Abstract Gait festination (FE) can cause serious disability in Parkinson's disease (PD) patients. It is argued that the center of pressure position (COP) and body center of mass (COM) are possibly implicated in FE pathogenesis. The relationship between them remains unclear. The goal of this study was to determine spatiotemporal relationships between COM and COP in PD and to explore whether FE arises as a consequence of lack of physiological link between COP and COM during step stride. Twenty patients with idiopathic PD, in OFF state and 17-age-matched control subjects completed a 10-m walking protocol. PD patients were divided in two groups: those with FE and those without (NF). COM position, excursion, and its relationship with COP, as well as other kinematic parameters were analyzed. COM displacement along the horizontal and vertical plane was significantly lower in FE patients as was the maximum position on the movement direction axis compared with controls or NF patients. Significant difference in minimal COM position in FE patients was also observed. The percentage of stride time during which COM was situated ahead of COP along the movement axis in FE patients was significantly greater than for controls or NF patients. This would seem to indicate that FE patients are constantly attempting to align COP to COM, causing FE. The explanation might be that FE arises as a postural strategy to align COP within the area of COM displacement. Findings illustrate a putative role for postural strategies in the treatment of FE. © 2010 Movement Disorder Society [source] Preface: phys. stat. sol. (b) 245/3PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 3 2008Christopher W. Smith This is the third Special Issue of physica status solidi (b) focusing on materials with a negative Poisson's ratio or other ,anomalous' physical properties. This issue contains selected papers from the First International Conference on Auxetics and Anomalous Systems held at the University of Exeter, UK, on 4,6 September 2006. Around 50 participants from all over the world as well as from a wide range of scientific and engineering disciplines contributed to what was a highly successful conference. This conference follows in the footsteps of two previous workshops held at the Mathematical Research and Conference Centre in B,dlewo near Pozna,, Poland, in 2004 and 2005 [1, 2]. The papers selected for this issue publish recent results obtained for ,anomalous systems' in experiment, theory and computer simulations. In the following we summarize very briefly their contents. Alderson and Coenen compare the performance of auxetic composites to similar systems with conventional positive Poisson's ratios. They find that there are indeed differences which appear to arise from the change of the overall Poisson's ratio of the composite, some beneficial like a rise in impact tolerance at low impact rates, and others deleterious such as the reduced tolerance at higher impact rates. This is one of the first investigations of possible applications for auxetic materials. The two papers by Gaspar and Koenders both examine the effects of disorder upon anomalous properties, especially negative Poisson's ratio. In the first one Gaspar demonstrates how a mean strain estimate fails to predict negative values of Poisson's ratio because of an inability to account for local fluctuations in elastic properties. For instance it is shown that the volume fraction of auxetic regions in an globally auxetic material (measured experimentally) are smaller than a mean strain homogenisation would require. Koenders and Gaspar explore the elastic properties, and especially Poisson's ratio, of a heterogeneous 2D network of bending beams. They predict auxetic behaviour arising from localised disorder in the packing, and therefore effective locally aggregated elastic properties of the beams. In the three articles by Gatt et al. and Grima et al. models based on simple geometry are used to explain the behaviour of seemingly disparate systems, i.e. 2D honeycombs systems and zeolite SiO2 networks. Two papers concerning honeycombs demonstrate relationships between elastic properties and structure and the bounds for auxetic behaviour. The paper concerning the zeolite Natrolite uses numerical force field based energy minimisation methods to simulate the response of this particular zeolite to applied forces and then simplifies the predicted properties even further by considering structural units as rigid 2D polyhedra linked by flexible hinges. In a similar vein, though using a different approach and concerning a very different form of matter, Heyes shows how the heterogeneity in an assembly of particles in a liquid can affect the elastic properties of a liquid and notably the infinite frequency Poisson's ratio. Heyes uses the Molecular Dynamics approach to simulate a Lennard,Jones fluid under various pressures, notably comparing behaviour under positive and negative pressures. In their first paper Jasiukiewicz and co-authors derive elastic constants of 2D crystals for all four classes of 2D crystalline solids: hexagonal (isotropic), quadratic, rectangular, and oblique systems. In their second paper they demonstrate conditions required for auxetic behaviour of 2D crystals. Auxetic solids are further divided into those with some negative Poisson's ratios (auxetic), all negative Poisson's ratios (completely auxetic) and no negative Poisson's ratios (non-auxetic). Lakes and Wojciechowski consider counterintuitive properties of matter, like negative compressibility, negative Poisson's ratio, negative thermal expansion, negative specific heat, and negative pressure. They present and interpret experimental observations of negative bulk modulus in pre-strained foams. They propose also a constrained microscopic model which exhibits negative compressibility. Finally, they solve a very simple thermodynamic model with negative thermal expansion. Martin et al. take a long stride toward a real world application of auxetic materials with a wide ranging study starting with numerical modelling of a wingbox section to experimental testing in a wind tunnel. They show that an auxetic core in a wing box section can allow a passive aero-elastic response which can be tailored by careful design of the core so that camber, and thus drag, is reduced with increasing airspeed but without sacrificing structural integrity. Miller et al. consider another anomalous physical property, negative thermal expansivity, and its application in the form of particulate composites for amelioration of stresses arising from thermal mismatch. They show via experiments that particles with a negative coefficient of thermal expansion may be used as a composite reinforcer to reduce overall thermal expansion and behave according to the standard volume fraction based models. Narojczyk and Wojciechowski examine the effects of disorder upon the bulk elastic properties of 3D fcc soft sphere systems in terms of particle size. Systems, such as colloids, can be thought of in such terms. The study shows that higher order moments of probability distribution do not influence the bulk elastic properties much, but that lower moments such as the standard deviation of particle size influence the elastic properties greatly. The "hardness" of the particle interaction potential is also important in this context. In general, it is shown that the effect of increasing polydispersity is to increase the Poisson's ratio, except the [110] [10] directions. Scarpa and Malischewsky in their paper on Rayleigh waves in auxetic materials show how the Rayleigh wave speed is affected by the Poisson's ratio. The behaviour is complex and depends upon the homogeneity within the material, for instance slowing with decreasing Poisson's ratio in isotropic solids, but showing the reverse trend and increased sensitivity to Poisson's ratio in laminate composites. Scarpa et al. explore the buckling behaviour of auxetic tubes via three types of model, a simple beam mechanics and Eulerian buckling model, a 3D linear elastic FE model and a bespoke non-linear continuum model. The more sophisticated models provide increasing insight into the buckling behaviour though the simple beam model predicts reasonably well in the pre-buckling linear region. Some unexpected and interesting behaviour is predicted by the continuum model as the Poisson's ratio approaches the isotropic limit of ,1, including increasing sensitivity to Poisson's ratio and rapid mode jumping between integer wave numbers. The paper by Shilko et al. presents an analysis of a particular kind of friction joint, a double lap joint, and explores the effects of altering the elastic properties of one component, in particular it's Poisson's ratio. The manuscript introduces the evolution of smart materials from monolithic materials, and the classification of composites exhibiting negative Poisson's ratios. The paper then presents the case of a double lap joint and performs a sensitivity type study, via a 2D FE model, of the effects of changing the elastic properties and degree of anisotropy of one section of the model on various parameters defining the limits of functionality of the joint. The main finding is that an enhanced shear modulus, via a negative Poisson's ratio, can endow such a friction joint with superior performance. Manufacturing of auxetic materials on a commercial scale has proved to be the largest obstacle to their fuller exploitation. The paper by Simkins et al. explores one route for post processing of auxetic polymers fibres produced by a conventional melt extrusion route. Simkins et al. showed that a post process thermal annealing treatment, with carefully optimised parameters, was able to even out otherwise inhomogenous auxetic properties, and moreover improve other elastic and fracture properties often sacrificed for auxetic behaviour. We gratefully acknowledge the support given by the sponsors of the conference, namely the EPSRC of the UK and Auxetic Technologies Ltd. (UK). We also thank the Scientific Committee, the Organising Committee, and all the participants of the conference. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Reliability of measurement of angular movements of the pelvis and lumbar spine during treadmill walkingPHYSIOTHERAPY RESEARCH INTERNATIONAL, Issue 4 2001Nicholas Taylor Abstract Background and Purpose Angular movements of the pelvis and lumbar spine are thought to play an important role in walking. However, little is known about the amount of unpredictable variability in measurement of these movements during human walking. The aim of the present study was to determine the retest reliability of measuring the angular movements of the pelvis and lumbar spine during unimpaired familiarized treadmill walking. Method Retest reliability for 26 subjects without pathology was determined over a one-week interval. Subjects walked on a treadmill at self-selected or a slower speed while measurements of the three-dimensional angular movements were taken with a computer-based video analysis system. Results The frontal plane movements of pelvic list and lumbar lateral flexion (relative to the pelvis) could be measured with high retest reliability at both self-selected and slow walking speeds (intraclass coefficient (ICC) (2,1) , 0.81). In contrast, transverse and sagittal plane movements demonstrated moderate reliability at both speeds (0.37 , ICC (2,1) , 0.76). Averaging the measurement over six strides resulted in increased observed reliability (self-selected walking speed summary Pearson's r = 0.71, slow walking speed summary Pearson's r = 0.79) compared to taking the measurement based on a single stride (self-selected walking speed summary Pearson's r = 0.63, slow walking speed summary Pearson's r = 0.67). Unlike pelvic and lumbar movements (relative to the pelvis), the measurement of lumbar movements (relative to the global reference frame) appeared to depend on whether subjects were walking at self-selected or slow speeds. Conclusions Measurement of pelvic list and lumbar lateral flexion (relative to the pelvis) could be applied with confidence to hypothesis testing about individuals or groups. Movements in the transverse and sagittal planes are unlikely to be appropriate in hypothesis testing about individuals and hence clinical practice, but may still have experimental applications in hypothesis testing about groups. Copyright © 2001 Whurr Publishers Ltd. [source] Gaits of Japanese macaques (Macaca fuscata) on a horizontal ladder and arboreal stabilityAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 4 2009Yasuo Higurashi Abstract Most primates use diagonal sequence (DS), diagonal couplets (DC) gaits when they walk or run quadrupedally, and it has been suggested that DSDC gaits contribute to stability in their natural arboreal habitats compared to other symmetrical gaits. However, this postulate is based solely on studies of primate gaits using continuous terrestrial and arboreal substrates. A particular species may select suitable gaits according to the substrate properties. Here, we analyzed the gaits of Japanese macaques moving on a horizontal ladder with rung intervals ranging from 0.40 to 0.80 m to elucidate the relative advantages of each observed form of gait. The rung arrangement forced our macaques to choose either diagonal coupling or DS gaits. One macaque consistently used diagonal coupling (i.e., DSDC and LSDC gaits) across narrow and intermediate rung intervals, whereas the other macaque used DS gaits (i.e., DSDC and DSLC gaits). At wider rung intervals, both macaques shifted to a two-one sequence (TOS), which is characterized by two nearly simultaneous touchdowns of both forelimbs and one touchdown of each hind limb in a stride. The transition to the TOS sequence increased the duration of support on multiple limbs, but always included periods of a whole-body aerial phase. These results suggest that Japanese macaques prefer DSDC gaits, because the diagonal coupling and DS contribute separately to stability on complex supports compared to the lateral coupling and lateral sequence. We also postulate that stability triggers the transition from symmetrical gaits to the TOS sequence. Am J Phys Anthropol, 2009. © 2008 Wiley-Liss, Inc. [source] Infant carrying: The role of increased locomotory costs in early tool developmentAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 2 2007C.M. Wall-Scheffler Abstract Among the costs of reproduction, carrying one's infant incurs one of the greatest drains on maternal energy, simply because of the added mass alone. Because of the dearth of archaeological evidence, however, how early bipeds dealt with the additional cost of having to carry infants who were less able to support their body weight against gravity is not particularly well understood. This article presents evidence on the caloric drain of carrying an infant in one's arms versus having a tool with which to sling the infant and carry her passively. The burden of carrying an infant in one's arms is on average 16% greater than having a tool to support the baby's mass and seems to have the potential to be a greater energetic burden even than lactation. In addition, carrying a baby in one's arms shortens and quickens the stride. An anthropometric trait that seems to offset some of the increased cost of carrying a baby in the arms is a wider bi-trochanteric width. Am J Phys Anthropol, 2007. © 2007 Wiley-Liss, Inc. [source] The relationship between limb morphology, kinematics, and force during running: the evolution of locomotor dynamics in lizardsBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 3 2009ERIC J. MCELROY Terrestrial locomotion occurs via the hierarchical links between morphology, kinematics, force, and center-of-mass mechanics. In a phylogenetically broad sample of seven lizard species, we show that morphological variation drives kinematic variation, which, in turn, drives force variation. Species with short limbs use a short stride,high frequency strategy when running at steady-speed and to change speeds. This link between morphology and kinematics results in relatively small vertical forces during the support phase of the stride cycle. Conversely, species with long limbs use a long stride,low frequency strategy, resulting in large vertical forces during the support phase. In view of these findings, we suggest that limb length may predict locomotor energetics in lizards because energetics are largely determined by vertical forces and stride frequency. Additionally, we propose an energetic trade-off with both long- and short-limbed species paying the most energy to move, whereas intermediate-limbed species move using less energy. Finally, when these traits are mapped onto a lizard phylogeny, we show that locomotor functional morphology exhibits both deep phylogenetic effects and contemporary patterns of evolutionary convergence. Overall, the present study provides a foundation for testing hypotheses regarding the integration and evolution of functional traits in lizards and animals in general. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 97, 634,651. [source] Islet transplantation: where do we stand now?,DIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 3 2003Boaz Hirshberg Abstract After many years of limited success in islet transplantation, researchers developing this procedure have made great strides, and several centers have now reported that islet transplantation can result in long-term insulin independence for patients with type 1 diabetes mellitus. The improved quality of life achieved in some islet allograft recipients suggests that this important line of investigation should proceed. Yet, several factors limit the technique and these hurdles must be overcome before it can be considered a practical treatment for the millions of individuals with diabetes, be it type 1 or type 2. Most obvious is the gross disparity between the number of islets available for clinical transplantation and the number of patients with diabetes who might benefit. Other important limitations, too often lost in the discussion, include complications associated with the technique itself, the toxicity of currently available immunosuppressive drugs, and the imperfect glycemia control achieved in most patients. In fact, our ongoing analysis as to whether transplantation-based therapy improves survival for patients with type 1 diabetes suggests that, for many at least, the opposite may be true. Two variables, as yet undefined, also need to be considered: (1) can the procedure, when done well, prevent or reverse diabetes-associated complications and (2) what are the long-term consequences of intrahepatic islets? Published in 2003 by John Wiley & Sons, Ltd. [source] Children and fighting forces: 10 years on from Cape TownDISASTERS, Issue 4 2009Lindsay Stark It is 10 years since the adoption of the Cape Town Principles and Best Practices on the Prevention of Recruitment of Children into the Armed Forces and on Demobilization and Social Reintegration of Child Soldiers in Africa. The field of programming for the reintegration of children associated with armed forces and armed groups has made significant strides in this period. However, important gaps in the knowledge base remain. This paper examines empirical evidence that supports lessons learned from work with children formerly connected with fighting forces. It evaluates what is known, where promising practice exists, and lacunae in five programming areas: psychosocial support and care; community acceptance; education, training and livelihoods; inclusive programming for all war-affected children; and follow-up and monitoring. While the 2007 Paris Commitments to Protect Children from Unlawful Recruitment or Use by Armed Forces or Groups mark an emerging consensus on many issues, there is still a critical need for more systematic studies to develop the evidence base supporting intervention in this area. [source] Use of a 3D dynamometric horseshoe to assess the effects of an all-weather waxed track and a crushed sand track at high speed trot: Preliminary studyEQUINE VETERINARY JOURNAL, Issue 3 2009D. Robin Summary Reasons for performing study: Track surface quality is considered a risk factor of musculoskeletal injuries. Ground reaction force (GRF) measurement is a relevant approach to study the interaction between the hoof and the ground. Force plates are not adapted to compare different surfaces at high speed. A 3D dynamometric horseshoe (DHS), using 4 triaxial piezoelectric sensors, has been developed and validated. Objectives: To use the DHS to compare the effects of 2 track surfaces, an all-weather waxed track and a crushed sand track, on the GRF in trotter horses under training conditions. Methods: The right forelimb of 3 French Trotters was equipped with the DHS. Two tracks were tested in a straight line: a crushed sand track (S) and an all-weather waxed track (W). For each session, trials were repeated 3 times in a Latin square design. The speed of the runs was set at 10 m/s and recorded synchronously. For each trial, data acquisition was performed at 600 Hz and 10 consecutive strides were analysed. Statistical differences were tested using a general linear model procedure. Results: The amplitude of the maximal longitudinal braking force (Fx) was significantly lower on W compared to S. This event happened about 6% later in the stance phase on W. The magnitude of the GRF at impact decreased on W. The average speed and the mean stance phase duration were not statistically different on both surfaces. The stride length was about 6 cm longer on S. Conclusion and potential relevance: This study demonstrates the ability and sensitivity of the DHS to discriminate track surfaces by measuring the GRF at high speed. These preliminary results show that the loading rate, the amplitude of horizontal braking and shock at impact are attenuated on W, which suggests a reduction of stresses in the distal limb. [source] Influence of track surface on the equine superficial digital flexor tendon loading in two horses at high speed trotEQUINE VETERINARY JOURNAL, Issue 3 2009N. Crevier-Denoix Summary Reasons for performing study: Although track surfaces are a risk factor of tendon injuries, their effects on tendon loading at high speed are unknown. Using a noninvasive ultrasonic technique, it is now possible to evaluate the forces in the superficial digital flexor tendon (SDFT) in exercise conditions. Objectives: To compare the effects of an all-weather waxed track (W) vs. a crushed sand track (S), on the SDFT loading in the trotter horse at high speed. Methods: Two trotter horses were equipped with the ultrasonic device (1 MHz ultrasonic probe, fixed on the palmar metacarpal area of the right forelimb). For each trial, data acquisition was made at 400 Hz and 10 consecutive strides were analysed. In each session, the 2 track surfaces were tested in a straight line. The speed was imposed at 10 m/s and recorded. The right forelimb was also equipped with a dynamometric horseshoe and skin markers. The horse was filmed with a high-speed camera (600 Hz); all recordings were synchronised. Statistical differences were tested using the GLM procedure (SAS; P<0.05). Results: Maximal tendon force was significantly lower on W compared with S. In addition to maximal force peaks around mid-stance, earlier peaks were observed, more pronounced on S than on W, at about 13%(horse 2) and 30% (both horses) of the stance phase. Comparison with kinematic data revealed that these early peaks were accompanied by plateaux in the fetlock angle-time chart. For high tendon forces, the tendon maximal loading rate was significantly lower on W than on S. Conclusions and potential clinical relevance: The all-weather waxed track appears to induce a lesser and more gradual SDFT loading than crushed sand. The SDFT loading pattern at high speed trot suggests proximal interphalangeal joint movements during limb loading. [source] Quantification of surface EMG signals to monitor the effect of a Botox treatment in six healthy ponies and two horses with stringhalt: Preliminary studyEQUINE VETERINARY JOURNAL, Issue 3 2009I. D. Wijnberg Summary Reasons for performing the study: Therapeutic options for stringhalt in horses are limited, whereas medical experiences with botulinum toxin type A (Botox) have been positive. To evaluate its effectiveness in horses, surface electromyography (sEMG) signals before and after injection need to be quantified. Hypothesis: Treatment of healthy ponies and cases with Botox should reduce muscle activity in injected muscles and reduce spastic movements without adverse side effects. Methods: Unilaterally, the extensor digitorum longus, extensor digitorum lateralis and lateral vastus muscles of 6 healthy mature Shetland ponies and 2 talented Dutch Warmblood dressage horses with stringhalt were injected (maximum of 400 iu per pony and 700 iu per case; 100 iu in 5 ml NaCl divided into 5 injections) with Botox under needle EMG guidance. Surface EMG data were evaluated using customised software, and in the individuals gait was analysed using Proreflex. Statistical analysis was performed using mixed models and independent sample t test (P<0.05). Results: Surface EMG signals were quantified using customised software. The area under the curve (integrated EMG) in time was used as variable. It became significantly reduced in injected muscles after injection of Botox in normal ponies (P<0.05). This effect was present from Day 1 until Day 84 after injection. In the 2 cases, after injection of 3 muscles, the integrated EMG in time became significantly reduced in all 3 muscles. Kinematic measurements confirmed reduction of frequency and amplitude of hyperflexing or hyperabducting strides of the affected hindlimbs. The duration of effect was also seen in the cases until around 12 weeks after injection. Conclusions and potential relevance: After EMG guided injections of Botox, sEMG signals recorded from injected muscle were reduced, which proves this to be a useful tool in statistically evaluating a treatment effect. The positive results of this pilot study encourage further research with a larger group of clinical cases. [source] Neural basis of timing and anticipatory behaviorsEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 9 2009Michael C. Antle Abstract The ability to anticipate physiological needs and to predict the availability of desirable resources optimizes the likelihood of survival for an organism. The neural basis of the complex behaviors associated with anticipatory responses is now being delineated. Anticipation likely involves learning and memory, reward and punishment, memory and cognition, arousal and feedback associated with changes in internal and external state, homeostatic processes and timing mechanisms. While anticipation can occur on a variety of timescales (seconds to minutes to hours to days to a year), there have been great strides made towards understanding the neural basis timing of events in the circadian realm. Anticipation of daily events, such as scheduled access to food, may serve as a useful model for a more broadly based understanding the neurobiology of anticipation. In this review we examine the historical, conceptual and experimental approaches to understanding the neural basis of anticipation with a focus on anticipation of scheduled daily meals. We also introduce the key topics represented in the papers in this issue. These papers focused on food anticipation, to explore the state of the art in the studies of the neural basis of timing and anticipatory behaviors. [source] Brittle-to-Ductile Transition in Uniaxial Compression of Silicon Pillars at Room TemperatureADVANCED FUNCTIONAL MATERIALS, Issue 15 2009Fredrik Östlund Abstract Robust nanostructures for future devices will depend increasingly on their reliability. While great strides have been achieved for precisely evaluating electronic, magnetic, photonic, elasticity and strength properties, the same levels for fracture resistance have been lacking. Additionally, one of the self-limiting features of materials by computational design is the knowledge that the atomistic potential is an appropriate one. A key property in establishing both of these goals is an experimentally-determined effective surface energy or the work per unit fracture area. The difficulty with this property, which depends on extended defects such as dislocations, is measuring it accurately at the sub-micrometer scale. In this Full Paper the discovery of an interesting size effect in compression tests on silicon pillars with sub-micrometer diameters is presented: in uniaxial compression tests, pillars having a diameter exceeding a critical value develop cracks, whereas smaller pillars show ductility comparable to that of metals. The critical diameter is between 310 and 400,nm. To explain this transition a model based on dislocation shielding is proposed. For the first time, a quantitative method for evaluating the fracture toughness of such nanostructures is developed. This leads to the ability to propose plausible mechanisms for dislocation-mediated fracture behavior in such small volumes. [source] How a major multinational is working to overcome the barriers to improved expatriate ROIGLOBAL BUSINESS AND ORGANIZATIONAL EXCELLENCE, Issue 3 2008Yvonne McNulty Despite the growing use of international assignments and the high cost of expatriates, few global firms have found the key to gauging the success of their mobility program, especially their expatriate return on investment (ROI). The author reports on one global firm that has made great strides towards a practical ROI tool by targeting the fundamental systems and processes needed to manage international assignments. The author also makes the case that an assignment's purpose, relative to business and/or organizational strategies, determines the types of inputs and outcomes to measure; and that ROI determinations for expatriates must include intangible and long-term benefits and costs. © 2008 Wiley Periodicals, Inc. [source] Carbon Nanotubes and Nanofluidic TransportADVANCED MATERIALS, Issue 35 2009Jason Knowles Holt Abstract Recent strides have been made in both the modeling and measurement of fluid flow on the nanoscale. Carbon nanotubes, with their atomic dimensions and atomic smoothness, are ideal materials for studying such flows. This Progress Report describes recent modeling and experimental advances concerning fluid transport in carbon nanotubes. The varied flow characteristics predicted by molecular dynamics are described, as are the roles of defects and chirality on transport. Analytical models are increasingly being used to describe nanofluidic transport by relaxing many of the assumptions commonly used to describe bulk water. Recent experimental studies examine the size dependence of flow enhancements through carbon nanotubes and use varied spectroscopies to probe water structure and dynamics in these systems. Carbon nanotubes are finding increasing applications in biology, from protein filters to platforms for cell interrogation. [source] Addressing agent loss in vehicle formations and sensor networksINTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 15 2009Tyler H. Summers Abstract In this paper, we address the problem of agent loss in vehicle formations and sensor networks via two separate approaches: (1) perform a ,self-repair' operation in the event of agent loss to recover desirable information architecture properties or (2) introduce robustness into the information architecture a priori such that agent loss does not destroy desirable properties. We model the information architecture as a graph G(V, E), where V is a set of vertices representing the agents and E is a set of edges representing information flow amongst the agents. We focus on two properties of the graph called rigidity and global rigidity, which are required for formation shape maintenance and sensor network self-localization, respectively. For the self-repair approach, we show that while previous results permit local repair involving only neighbours of the lost agent, the repair cannot always be implemented using only local information. We present new results that can be applied to make the local repair using only local information. We describe implementation and illustrate with algorithms and examples. For the robustness approach, we investigate the structure of graphs with the property that rigidity or global rigidity is preserved after removing any single vertex (we call the property as 2-vertex-rigidity or 2-vertex-global-rigidity, respectively). Information architectures with such properties would allow formation shape maintenance or self-localization to be performed even in the event of agent failure. We review a characterization of a class of 2-vertex-rigidity and develop a separate class, making significant strides towards a complete characterization. We also present a characterization of a class of 2-vertex-global-rigidity. Copyright © 2008 John Wiley & Sons, Ltd. [source] The Enantioselective Addition of Alkyne Nucleophiles to Carbonyl GroupsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 7-8 2009Barry Abstract Over the past decade, large strides have been achieved in the invention of methods for the direct enantioselective addition of alkynes and metal alkynylide nucleophiles into prochiral aldehydes, ketones, and imines. This review highlights and compares the available methods for these transformations. [source] Safety and therapeutic efficacy of undenatured type-ii collagen (UC-II) in comparison to glucosamine and chondroitin in arthritic horsesJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 2 2009R. C. Gupta Osteoarthritis (OA) is the most common form of arthritis, which causes severe inflammation and loss of cartilage. It is a debilitating disease that commonly affects thousands of horses each year. Recently, we assessed the anti-arthritic and anti-inflammatory potential of undenatured type II collagen (UC-II) in horses. This comparative investigation evaluated arthritic pain in horses receiving daily placebo, UC-II 320 mg/day (providing 80 mg active UC-II), 480 mg/day (providing 120 mg active UC-II), or 640 mg/day (providing 160 mg active UC-II), and glucosamine and chondroitin (5.4 g/day and 1.8 g/day, respectively, bid for the first month, and thereafter once daily) for 150 days. Pain in each leg was evaluated using the flexion test and the lameness-grading system after the initial two strides. Average pain of all four legs represented the pain for each horse. Horses receiving placebo showed no change in arthritic condition, while those receiving 320, 480, or 640 mg UC-II exhibited significant reduction in arthritic pain (P < 0.05). UC-II at 480 mg dose provided optimal effects. With this dose, reduction in overall pain was from 5.7 ± 0.0.42 (100%) to 0.7 ± 0.42 (12%); and in pain upon limb manipulation from 2.35 ± 0.37 (100%) to 0.52 ± 0.18 (22%). In regards to glucosamine and chondroitin treated group, although reduction in pain was significant compared to pretreated values, the efficacy was significantly less compared with that observed with UC-II. UC-II was found to be twice as effective as glucosamine and chondroitin in arthritic horses. Clinically, physical condition, and liver (ALP, GGT, and bilirubin), kidney (BUN and creatinine), and heart (CK) functions remained unchanged, suggesting that these supplements were well tolerated. Overall, these results demonstrate that UC-II was significantly more efficacious than glucosamine and chondroitin in arthritic horses. [source] The limited capacity model of mediated message processingJOURNAL OF COMMUNICATION, Issue 1 2000A Lang This paper presents an information-processing model that is directly applicable to the investigation of how mediated messages are processed. It applies the model to the case of television viewing to demonstrate its applicability. It provides a measure for each part of the model. It presents evidence that supports the model in the television-viewing situation. Finally, it demonstrates how the model may be used to further research and understanding in well-known theoretical traditions. This model is not meant to stand in opposition to any of these theories but, rather, should work well with them by providing hypothesized mechanisms that may underlie well-known effects. This model should prove useful both to researchers and, eventually, to message producers. To the extent that we can better understand how the content and structure of messages interact with a viewer's information-processing system to determine which parts and how much of a communication message is remembered, we will make great strides in understanding how people communicate. [source] MOISTURE SORPTION ISOTHERM, PROPERTIES OF SORBED WATER AND HEAT OF SORPTION OF SANDESH, AN INDIAN MILK PRODUCTJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 1 2010J.K. SAHU ABSTRACT Moisture sorption isotherm of sandesh, one of the most popular milk products in India, was determined in terms of its moisture adsorption isotherms by gravimetrical method at 20 and 30C using various saturated salt solutions in the range of 11.2 to 97.2%. The isotherms obtained were of sigmoid shape and of the Brunauer,Emmett,Teller type. Out of three sorption models fitted to the experimental data, Caurie's model was found superior in interpreting the moisture adsorption characteristics of sandesh. The monolayer moisture content as calculated from the Caurie's model at 20 and 30C were 5.89% (dry basis [d.b.]) and 5.21% (d.b.), respectively. The values of isosteric heat of sorption as calculated from Clausius,Clapeyron equation was found to increase with decreasing moisture content at lower moisture content and approached the value of heat of vaporization of free water above 17.25% (d.b.). PRACTICAL APPLICATIONS The present paper describes basically the storage stability of sandesh. The sandesh is a heat,acid coagulated product of milk in Indian subcontinent and forms the part and parcel of social life, ceremonies and festivals. It has an excellent market potential and higher profit margin compared with other milk products like table butter, cheese and milk powder. Although Indian dairy industry has made rapid strides in the last few decades, there is no proper packaging system, developed so far, for storage of sandesh. Keeping pace with the growing consumers' demand for fresh, convenient and microbiologically free foods, design of proper packaging system is the need of the hour. The data presented in the paper will be very much essential for the researchers and research and development institutions for proper designing of packaging system for sandesh. [source] Ultrasonic-activated micellar drug delivery for cancer treatmentJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 3 2009Ghaleb A. Husseini Abstract The use of nanoparticles and ultrasound in medicine continues to evolve. Great strides have been made in the areas of producing micelles, nanoemulsions, and solid nanoparticles that can be used in drug delivery. An effective nanocarrier allows for the delivery of a high concentration of potent medications to targeted tissue while minimizing the side effect of the agent to the rest of the body. Polymeric micelles have been shown to encapsulate therapeutic agents and maintain their structural integrity at lower concentrations. Ultrasound is currently being used in drug delivery as well as diagnostics, and has many advantages that elevate its importance in drug delivery. The technique is noninvasive, thus no surgery is needed; the ultrasonic waves can be easily controlled by advanced electronic technology so that they can be focused on the desired target volume. Additionally, the physics of ultrasound are widely used and well understood; thus ultrasonic application can be tailored towards a particular drug delivery system. In this article, we review the recent progress made in research that utilizes both polymeric micelles and ultrasonic power in drug delivery. © 2008 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:795,811, 2009 [source] | ||||||||||||||||||||||||||||||||||