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Sample records for dynamic foot function

  1. Perspectives for clinical measures of dynamic foot function-reference data and methodological considerations.

    Science.gov (United States)

    Rathleff, M S; Nielsen, R G; Simonsen, O; Olesen, C G; Kersting, U G

    2010-02-01

    Several studies have investigated if static posture assessments qualify to predict dynamic function of the foot showing diverse outcomes. However, it was suggested that dynamic measures may be better suited to predict foot-related overuse problems. The purpose of this study was to establish the reliability for dynamic measures of longitudinal arch angle (LAA) and navicular height (NH) and to examine to what extent static and dynamic measures thereof are related. Intra-rater reliability of LAA and NH measures was tested on a sample of 17 control subjects. Subsequently, 79 subjects were tested while walking on a treadmill. The ranges and minimum values for LAA and NH during ground contact were identified over 20 consecutive steps. A geometric error model was used to simulate effects of marker placement uncertainty and skin movement artifacts. Results demonstrated the highest reliability for the minimum NH (MinNH), followed by the minimum LAA (MinLAA), the dynamic range of navicular height (DeltaNH) and the range of LAA (DeltaLAA) while all measures were highly reliable. Marker location uncertainty and skin movement artifacts had the smallest effects on measures of NH. The use of an alignment device for marker placement was shown to reduce error ranges for NH measures. Therefore, DeltaNH and MinNH were recommended for functional dynamic foot characterization in the sagittal plane. There is potential for such measures to be a suitable predictor for overuse injuries while being obtainable in clinical settings. Future research needs to include such dynamic but simple foot assessments in large-scale clinical studies.

  2. Dynamic Foot Morphology

    OpenAIRE

    Barisch-Fritz, Bettina

    2014-01-01

    Background: The foot has to fulfil important and complex functions which are, in most regions of the world, supported by shoes. The interface of feet and footwear has often been considered with respect to comfort and function but also to negative effects of shoes. One main contribution to the improvement of footwear fit is provided by matching the shape of the shoe to the shape of the foot. However, current approaches for implementation only include static information. There is still a lack o...

  3. Foot posture, foot function and low back pain: the Framingham Foot Study.

    Science.gov (United States)

    Menz, Hylton B; Dufour, Alyssa B; Riskowski, Jody L; Hillstrom, Howard J; Hannan, Marian T

    2013-12-01

    Abnormal foot posture and function have been proposed as possible risk factors for low back pain, but this has not been examined in detail. The objective of this study was to explore the associations of foot posture and foot function with low back pain in 1930 members of the Framingham Study (2002-05). Low back pain, aching or stiffness on most days was documented on a body chart. Foot posture was categorized as normal, planus or cavus using static weight-bearing measurements of the arch index. Foot function was categorized as normal, pronated or supinated using the centre of pressure excursion index derived from dynamic foot pressure measurements. Sex-specific multivariate logistic regression models were used to examine the associations of foot posture, foot function and asymmetry with low back pain, adjusting for confounding variables. Foot posture showed no association with low back pain. However, pronated foot function was associated with low back pain in women [odds ratio (OR) = 1.51, 95% CI 1.1, 2.07, P = 0.011] and this remained significant after adjusting for age, weight, smoking and depressive symptoms (OR = 1.48, 95% CI 1.07, 2.05, P = 0.018). These findings suggest that pronated foot function may contribute to low back symptoms in women. Interventions that modify foot function, such as orthoses, may therefore have a role in the prevention and treatment of low back pain.

  4. The Predictive Value of the Foot Posture Index on Dynamic Function

    DEFF Research Database (Denmark)

    Mølgaard, Carsten Møller; Olesen Gammelgaard, Christian; Nielsen, R. G.;

    2008-01-01

    Keenan et. al. identified the six-item version of the Foot Posture Index (FPI) as a valid, simple and clinically useful tool. The model combines measures of the standing foot posture in multiple planes and anatomical segments. It provides an alternative to existing static clinical measures when...... dynamic measures are not feasible. Redmond et. al. found the model able to predict 41% of the variation in the complex rotation of the ankle joint, representing inversion/eversion, during midstance of walking. To our knowledge no studies have been published on the relationship between FPI and the movement...... of the midfoot during walking. The purpose of this study was to investigate the use of FPI classification as a predictor for dynamic midfoot kinematics during walking....

  5. The predictive value of the foot posture index on dynamic function

    DEFF Research Database (Denmark)

    Nielsen, Rasmus Gottschalk N; Rathleff, M; Kersting, U G;

    2008-01-01

    Keenan et. al. identified the six-item version of the Foot Posture Index (FPI) as a valid, simple and clinically useful tool. The model combines measures of the standing foot posture in multiple planes and anatomical segments. It provides an alternative to existing static clinical measures when...... dynamic measures are not feasible. Redmond et. al. found the model able to predict 41% of the variation in the complex rotation of the ankle joint, representing inversion/eversion, during midstance of walking. To our knowledge no studies have been published on the relationship between FPI and the movement...... of the midfoot during walking. The purpose of this study was to investigate the use of FPI classification as a predictor for dynamic midfoot kinematics during walking....

  6. The predictive value of the foot posture index on dynamic function

    DEFF Research Database (Denmark)

    Nielsen, Rasmus Gottschalk; Rathleff, Michael Skovdal; Kersting, U G;

    2008-01-01

    dynamic measures are not feasible. Redmond et. al. found the model able to predict 41% of the variation in the complex rotation of the ankle joint, representing inversion/eversion, during midstance of walking. To our knowledge no studies have been published on the relationship between FPI and the movement...... of the midfoot during walking. The purpose of this study was to investigate the use of FPI classification as a predictor for dynamic midfoot kinematics during walking.......Keenan et. al. identified the six-item version of the Foot Posture Index (FPI) as a valid, simple and clinically useful tool. The model combines measures of the standing foot posture in multiple planes and anatomical segments. It provides an alternative to existing static clinical measures when...

  7. The predictive value of the foot posture index on dynamic function

    DEFF Research Database (Denmark)

    Nielsen, R.G.; Ratleff, M.; Kersting, Uwe G.

    2008-01-01

    Keenan et. al. identified the six-item version of the Foot Posture Index (FPI) as a valid, simple and clinically useful tool. The model combines measures of the standing foot posture in multiple planes and anatomical segments. It provides an alternative to existing static clinical measures when...

  8. The Predictive Value of the Foot Posture Index on Dynamic Function

    DEFF Research Database (Denmark)

    Nielsen, R.G.; Rathleff, M.; Kersting, Uwe G.

    Keenan et. al. identified the six-item version of the Foot Posture Index (FPI) as a valid, simple and clinically useful tool. The model combines measures of the standing foot posture in multiple planes and anatomical segments. It provides an alternative to existing static clinical measures when...

  9. Association between hip abductor function, rear-foot dynamic alignment, and dynamic knee valgus during single-leg squats and drop landings

    Directory of Open Access Journals (Sweden)

    Yoshinori Kagaya

    2015-06-01

    Conclusion: Dynamic hip mal-alignment might be associated with both greater KID and HOD, whereas rear-foot eversion is associated only with greater KID. Hip abductor and rear-foot dysfunction are important factors for dynamic knee valgus and thus evaluating DTT and HFT will help to prevent dynamic knee valgus.

  10. Foot posture, foot function and low back pain: the Framingham Foot Study

    OpenAIRE

    Menz, Hylton B; Dufour, Alyssa B; Riskowski, Jody L; Hillstrom, Howard J.; Hannan, Marian T.

    2013-01-01

    Objective. Abnormal foot posture and function have been proposed as possible risk factors for low back pain, but this has not been examined in detail. The objective of this study was to explore the associations of foot posture and foot function with low back pain in 1930 members of the Framingham Study (2002–05).

  11. The foot core system: a new paradigm for understanding intrinsic foot muscle function.

    Science.gov (United States)

    McKeon, Patrick O; Hertel, Jay; Bramble, Dennis; Davis, Irene

    2015-03-01

    The foot is a complex structure with many articulations and multiple degrees of freedom that play an important role in static posture and dynamic activities. The evolutionary development of the arch of the foot was coincident with the greater demands placed on the foot as humans began to run. The movement and stability of the arch is controlled by intrinsic and extrinsic muscles. However, the intrinsic muscles are largely ignored by clinicians and researchers. As such, these muscles are seldom addressed in rehabilitation programmes. Interventions for foot-related problems are more often directed at externally supporting the foot rather than training these muscles to function as they are designed. In this paper, we propose a novel paradigm for understanding the function of the foot. We begin with an overview of the evolution of the human foot with a focus on the development of the arch. This is followed by a description of the foot intrinsic muscles and their relationship to the extrinsic muscles. We draw the parallels between the small muscles of the trunk region that make up the lumbopelvic core and the intrinsic foot muscles, introducing the concept of the foot core. We then integrate the concept of the foot core into the assessment and treatment of the foot. Finally, we call for an increased awareness of the importance of the foot core stability to normal foot and lower extremity function. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  12. Relationships between foot type and dynamic rearfoot frontal plane motion

    Directory of Open Access Journals (Sweden)

    Chuter Vivienne H

    2010-06-01

    Full Text Available Abstract Background The Foot Posture Index (FPI provides an easily applicable, validated method for quantifying static foot posture. However there is limited evidence relating to the ability of the FPI to predict dynamic foot function. This study aimed to assess the relationship between dynamic rearfoot motion and FPI scores in pronated and normal foot types. Methods 40 participants were recruited with equal numbers of pronated and normal foot types as classified by their FPI score. Three dimensional rearfoot motion was collected for each of the participants. Dynamic maximum rearfoot eversion was correlated with the total FPI score across all participants and within the normal and pronated foot types. Linear correlations were performed between components of the total FPI scores measuring frontal plane rearfoot position and maximum rearfoot eversion. The capacity of the total FPI score to predict maximum frontal plane motion of the rearfoot was investigated using linear regression analysis. Results The correlation between the total FPI score and maximum rearfoot eversion was strongly positive (r = 0.92, p 2 = 0.85, p Conclusions The results of this study suggest the FPI has strong predictive ability for dynamic rearfoot function. This will assist in clinical screening and research by allowing easy classification by functional foot type. Positive correlations between frontal plane rearfoot measurements and maximum rearfoot eversion suggest the FPI may identify dominant planar components of dynamic rearfoot motion and warrants further investigation.

  13. Assessment of a virtual functional prototyping process for the rapid manufacture of passive-dynamic ankle-foot orthoses.

    Science.gov (United States)

    Schrank, Elisa S; Hitch, Lester; Wallace, Kevin; Moore, Richard; Stanhope, Steven J

    2013-10-01

    Passive-dynamic ankle-foot orthosis (PD-AFO) bending stiffness is a key functional characteristic for achieving enhanced gait function. However, current orthosis customization methods inhibit objective premanufacture tuning of the PD-AFO bending stiffness, making optimization of orthosis function challenging. We have developed a novel virtual functional prototyping (VFP) process, which harnesses the strengths of computer aided design (CAD) model parameterization and finite element analysis, to quantitatively tune and predict the functional characteristics of a PD-AFO, which is rapidly manufactured via fused deposition modeling (FDM). The purpose of this study was to assess the VFP process for PD-AFO bending stiffness. A PD-AFO CAD model was customized for a healthy subject and tuned to four bending stiffness values via VFP. Two sets of each tuned model were fabricated via FDM using medical-grade polycarbonate (PC-ISO). Dimensional accuracy of the fabricated orthoses was excellent (average 0.51 ± 0.39 mm). Manufacturing precision ranged from 0.0 to 0.74 Nm/deg (average 0.30 ± 0.36 Nm/deg). Bending stiffness prediction accuracy was within 1 Nm/deg using the manufacturer provided PC-ISO elastic modulus (average 0.48 ± 0.35 Nm/deg). Using an experimentally derived PC-ISO elastic modulus improved the optimized bending stiffness prediction accuracy (average 0.29 ± 0.57 Nm/deg). Robustness of the derived modulus was tested by carrying out the VFP process for a disparate subject, tuning the PD-AFO model to five bending stiffness values. For this disparate subject, bending stiffness prediction accuracy was strong (average 0.20 ± 0.14 Nm/deg). Overall, the VFP process had excellent dimensional accuracy, good manufacturing precision, and strong prediction accuracy with the derived modulus. Implementing VFP as part of our PD-AFO customization and manufacturing framework, which also includes fit customization, provides a novel and powerful method to

  14. Foot deformation during walking: differences between static and dynamic 3D foot morphology in developing feet.

    Science.gov (United States)

    Barisch-Fritz, Bettina; Schmeltzpfenning, Timo; Plank, Clemens; Grau, Stefan

    2014-01-01

    The complex functions of feet require a specific composition, which is progressively achieved by developmental processes. This development should take place without being affected by footwear. The aim of this study is to evaluate differences between static and dynamic foot morphology in developing feet. Feet of 2554 participants (6-16 years) were recorded using a new scanner system (DynaScan4D). Each foot was recorded in static half and full weight-bearing and during walking. Several foot measures corresponding to those used in last construction were calculated. The differences were identified by one-way ANOVA and paired Student's t-test. Static and dynamic values of each foot measure must be considered to improve the fit of footwear. In particular, footwear must account for the increase of forefoot width and the decrease of midfoot girth. Furthermore, the toe box should have a more rounded shape. The findings are important for the construction of footwear for developing feet.

  15. A dynamic 3D foot reconstruction system.

    Science.gov (United States)

    Thabet, Ali K; Trucco, Emanuele; Salvi, Joaquim; Wang, Weijie; Abboud, Rami J

    2011-01-01

    Foot problems are varied and range from simple disorders through to complex diseases and joint deformities. Wherever possible, the use of insoles, or orthoses, is preferred over surgery. Current insole design techniques are based on static measurements of the foot, despite the fact that orthoses are prevalently used in dynamic conditions while walking or running. This paper presents the design and implementation of a structured-light prototype system providing dense three dimensional (3D) measurements of the foot in motion, and its use to show that foot measurements in dynamic conditions differ significantly from their static counterparts. The input to the system is a video sequence of a foot during a single step; the output is a 3D reconstruction of the plantar surface of the foot for each frame of the input. Engineering and clinical tests were carried out for the validation of the system. The accuracy of the system was found to be 0.34 mm with planar test objects. In tests with real feet, the system proved repeatable, with reconstruction differences between trials one week apart averaging 2.44 mm (static case) and 2.81 mm (dynamic case). Furthermore, a study was performed to compare the effective length of the foot between static and dynamic reconstructions using the 4D system. Results showed an average increase of 9 mm for the dynamic case. This increase is substantial for orthotics design, cannot be captured by a static system, and its subject-specific measurement is crucial for the design of effective foot orthoses.

  16. The Effect of Taping on Foot Structure, Functional Foot Stability and Running Gait Patterns of the Foot

    Institute of Scientific and Technical Information of China (English)

    Malia Ho; Tsai Djun; John Cher Chay Tan

    2015-01-01

    Running related foot injuries are associated with excessive foot movements due to malaligned foot structure and poor functional foot stability. Clinicians tape the foot to alleviate pain and prevent further injuries, whilst allowing the athlete to continue training. However, the effect of taping is not conclusive. The purpose of this study is to investigate if taping effectively improves foot structure, functional foot stability and reduces excessive foot movements during running. Twenty-two subjects had their foot structure identified as: fiat foot stable, fiat foot unstable and normal arched unstable according to the FPI (foot posture index) and the Modified Romberg's Test with the BESS (balance error scoring system) criteria. The subjects ran on an instrumented treadmill barefooted with their feet taped and untaped. Running kinetic and kinematic data were collected and analysed using a paired t-test and 3x2 ANOVA. Taping improved foot structure but not functional foot stability. During running, taping significantly reduced rearfoot eversion. Taping increased the loading rate in the fiat foot and normal arched unstable groups but reduced the loading rate for the flat foot stable group. Implication on the appropriate use of foot taping was discussed.

  17. The effects of dynamic ankle-foot orthoses on functional ambulation activities, weight bearing and spatio-temporal characteristics of hemiparetic gait.

    Science.gov (United States)

    Suat, Erel; Fatma, Uygur; Nilgün, Bek

    2011-01-01

    To investigate the effects of dynamic ankle-foot orthoses (DAFOs) on functional ambulation activities, weight bearing and spatio-temporal characteristics of hemiparetic gait and to inquire whether wearing a DAFO for 3 months has a carryover effect. Fourteen chronic hemiparetic patients who could walk independently with or without a cane were the subjects of the study. Patients were assessed initially with tennis shoes and were given custom fabricated DAFOs which they wore for three months and were retested under two conditions: with tennis shoes only and with DAFOs worn in these shoes. All patients were assessed for weight bearing percentage of the affected side, cadence, step length of the involved and uninvolved sides, step width, functional reach, timed up and go, timed down stairs, timed up stairs, physiologic cost index and velocity. Comparison of initial and third month assessments with shoes only condition showed that there was no significant improvement for the measured parameters. When comparison was made at the third month while patients were wearing tennis shoes only and when they were wearing DAFO's in their shoes there was a significant difference in favour of the condition where patients were wearing DAFOs. The benefits of using DAFOs in chronic hemiparetic patients are lost when the patients are not wearing their orthoses.

  18. Foot roll-over evaluation based on 3D dynamic foot scan.

    Science.gov (United States)

    Samson, William; Van Hamme, Angèle; Sanchez, Stéphane; Chèze, Laurence; Van Sint Jan, Serge; Feipel, Véronique

    2014-01-01

    Foot roll-over is commonly analyzed to evaluate gait pathologies. The current study utilized a dynamic foot scanner (DFS) to analyze foot roll-over. The right feet of ten healthy subjects were assessed during gait trials with a DFS system integrated into a walkway. A foot sole picture was computed by vertically projecting points from the 3D foot shape which were lower than a threshold height of 15 mm. A 'height' value of these projected points was determined; corresponding to the initial vertical coordinates prior to projection. Similar to pedobarographic analysis, the foot sole picture was segmented into anatomical regions of interest (ROIs) to process mean height (average of height data by ROI) and projected surface (area of the projected foot sole by ROI). Results showed that these variables evolved differently to plantar pressure data previously reported in the literature, mainly due to the specificity of each physical quantity (millimeters vs Pascals). Compared to plantar pressure data arising from surface contact by the foot, the current method takes into account the whole plantar aspect of the foot, including the parts that do not make contact with the support surface. The current approach using height data could contribute to a better understanding of specific aspects of foot motion during walking, such as plantar arch height and the windlass mechanism. Results of this study show the underlying method is reliable. Further investigation is required to validate the DFS measurements within a clinical context, prior to implementation into clinical practice.

  19. The role of foot morphology on foot function in diabetic subjects with or without neuropathy.

    Science.gov (United States)

    Guiotto, Annamaria; Sawacha, Zimi; Guarneri, Gabriella; Cristoferi, Giuseppe; Avogaro, Angelo; Cobelli, Claudio

    2013-04-01

    The aim of this study was to investigate the role of foot morphology, related with respect to diabetes and peripheral neuropathy in altering foot kinematics and plantar pressure during gait. Healthy and diabetic subjects with or without neuropathy with different foot types were analyzed. Three dimensional multisegment foot kinematics and plantar pressures were assessed on 120 feet: 40 feet (24 cavus, 20 with valgus heel and 11 with hallux valgus) in the control group, 80 feet in the diabetic (25 cavus 13 with valgus heel and 13 with hallux valgus) and the neuropathic groups (28 cavus, 24 with valgus heel and 18 with hallux valgus). Subjects were classified according to their foot morphology allowing further comparisons among the subgroups with the same foot morphology. When comparing neuropathic subjects with cavus foot, valgus heel with controls with the same foot morphology, important differences were noticed: increased dorsiflexion and peak plantar pressure on the forefoot (Pfoot morphology in altering both kinematics and plantar pressure in diabetic subjects, diabetes appeared to further contribute in altering foot biomechanics. Surprisingly, all the diabetic subjects with normal foot arch or with valgus hallux were no more likely to display significant differences in biomechanics parameters than controls. This data could be considered a valuable support for future research on diabetic foot function, and in planning preventive interventions.

  20. A kinematic description of dynamic midfoot break in children using a multi-segment foot model.

    Science.gov (United States)

    Maurer, Jessica D; Ward, Valerie; Mayson, Tanja A; Davies, Karen R; Alvarez, Christine M; Beauchamp, Richard D; Black, Alec H

    2013-06-01

    Midfoot break (MFB) is a foot deformity that occurs most commonly in children with cerebral palsy (CP), but may also affect children with other developmental disorders. Dynamic MFB develops because the muscles that cross the ankle joint are hypertonic, resulting in a breakdown and dysfunction of the bones within the foot. In turn, this creates excessive motion at the midfoot. With the resulting inefficient lever arm, the foot is then unable to push off the ground effectively, resulting in an inadequate and painful gait pattern. Currently, there is no standard quantitative method for detecting early stages of MFB, which would allow early intervention before further breakdown occurs. The first step in developing an objective tool for early MFB diagnosis is to examine the difference in dynamic function between a foot with MFB and a typical foot. Therefore, the main purpose of this study was to compare the differences in foot motion between children with MFB and children with typical feet (Controls) using a multi-segment kinematic foot model. We found that children with MFB had a significant decrease in peak ankle dorsiflexion compared to Controls (1.3 ± 6.4° versus 8.6 ± 3.4°) and a significant increase in peak midfoot dorsiflexion compared to Controls (15.2 ± 4.9° versus 6.4 ± 1.9°). This study may help clinicians track the progression of MFB and help standardize treatment recommendations for children with this type of foot deformity.

  1. The Dynamic Stiffness of Surface Footings for Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Vahdatirad, Mohammadjavad; Andersen, Lars; Clausen, Johan;

    2011-01-01

    This study concerns the dynamic stiffness of foundations for large offshore wind turbines. Especially, the purpose of the analysis is to quantify the uncertainties related to the first natural frequency of a turbine supported by a surface footing on layered soil. The dynamic properties...... due to sediment transportation. Further, the stiffness and density of the materials within a single layer is subject to uncertainties. This leads to uncertainties of the dynamic stiffness of the foundation and therefore the natural frequencies. The aim of the study is to quantify the level...... of uncertainties and discuss the utilization of reliability-based design of surface footings for wind turbines....

  2. Functional clinical typology of the foot and kinematic gait parameters

    Directory of Open Access Journals (Sweden)

    Jitka Marenčáková

    2016-06-01

    Full Text Available Background: The foot plays a key role in a standing posture, walking and running performance. Changes in its structure or function may alter upper segments of kinematic chain which can lead to formation of musculoskeletal disorders. Although functional clinical typology provides a complex view of foot kinesiology there is a lack of knowledge and evidence about influences of different foot types on human gait. Objective: The aim of the study was to analyse differences of kinematic gait parameters of lower extremity joints and pelvis between functional clinical foot types in healthy young men. Methods: Three-dimensional kinematic analysis by the Vicon Motion Capture MX System device in synchronization with 2 Kistler force platforms was used to obtain kinematic data from 18 healthy men (mean age 23.2 ± 1.9 years. The functional clinical foot type was clinically examined and sorted into 3 basic foot type groups - forefoot varus (FFvar, rearfoot varus (RFvar and forefoot valgus (FFvalg. Peak angular values and range of an angular displacement in all of three movement planes were analysed for pelvis, hip, knee and ankle joint. For statistical analysis of kinematic gait parameters differences between foot types Mann Whitney U test at a statistical significance level p < .05 and Cohen's coefficient d for effect size were used. Results: This study showed that functional clinical foot type can affect kinematic parameters of gait in the joints of the lower limb and pelvis. Significant differences were presented in the FFvar in comparison with other two foot type groups with middle and high size of effect. The most alterations were observed in pelvis area and in a sagittal plane of movement. Nevertheless, significant differences between FFvalg and RFvar foot types were not noticed. Conclusions: Functional clinical foot typology provides one of the possible methods to describe foot structure and function. Our results showed that foot type could

  3. The relationships between foot arch volumes and dynamic plantar pressure during midstance of walking in preschool children.

    Directory of Open Access Journals (Sweden)

    Hsun-Wen Chang

    Full Text Available OBJECTIVES: The purpose of this study was to examine the correlation between the foot arch volume measured from static positions and the plantar pressure distribution during walking. METHODS: A total of 27 children, two to six years of age, were included in this study. Measurements of static foot posture were obtained, including navicular height and foot arch volume in sitting and standing positions. Plantar pressure, force and contact areas under ten different regions of the foot were obtained during walking. RESULTS: The foot arch index was correlated (r = 0.32 with the pressure difference under the midfoot during the foot flat phase. The navicular heights and foot arch volumes in sitting and standing positions were correlated with the mean forces and pressures under the first (r = -0.296∼-0.355 and second metatarsals (r = -0.335∼-0.504 and midfoot (r = -0.331∼-0.496 during the stance phase of walking. The contact areas under the foot were correlated with the foot arch parameters, except for the area under the midfoot. CONCLUSIONS: The foot arch index measured in a static position could be a functional index to predict the dynamic foot functions when walking. The foot arch is a factor which will influence the pressure distribution under the foot. Children with a lower foot arch demonstrated higher mean pressure and force under the medial forefoot and midfoot, and lower contact areas under the foot, except for the midfoot region. Therefore, children with flatfoot may shift their body weight to a more medial foot position when walking, and could be at a higher risk of soft tissue injury in this area.

  4. Functional limitations due to foot involvement in spondyloarthritis

    Science.gov (United States)

    Ozaras, Nihal; Havan, Nuri; Poyraz, Emine; Rezvanı, Aylin; Aydın, Teoman

    2016-01-01

    [Purpose] Spondyloarthritis is a major inflammatory disease followed-up in the rheumatology clinics, foot involvement in spodyloarthritis is common. The functional states of patients with spondyloarthritis are usually evaluated globally. The aim of this study was to assess the foot involvement-related functional limitations in patients with spondyloarthritis. [Subjects and Methods] Patients with ankylosing spondylitis and psoriatic arthritis with foot pain more than 4 weeks who underwent anteroposterior and lateral feet radiography were enrolled into the study. A “clinical findings score” was calculated by assigning 1 point for every finding of swelling, redness, and tenderness. C-reactive protein and erythrocyte sedimentation rate were used as serum markers for disease activity. Foot radiograms were evaluated using the spondyloarthropathy tarsal radiographic index and the foot-related functional state of patients was determined by the Turkish version of the Foot and Ankle Outcome Score. [Results] There were no relationships between Foot and Ankle Outcome Score subscales and clinical findings score, serum markers, or radiologic score. Pain and symptoms subscale scores were result positively correlated with activity of daily living, sport and recreation, and quality of life subscale scores. [Conclusion] Pain and symptoms are the main determinants of foot-related functional limitations in spondyloarthritis. PMID:27512252

  5. Functional limitations related to foot pain in the elderly

    Directory of Open Access Journals (Sweden)

    Fabiana Maria Rodrigues Lopes de Oliveira

    2015-09-01

    Full Text Available Objective: to investigate the association between foot pain and functional disability in the elderly. Methods: descriptive study conducted among the elderly attended in a geriatric outpatient clinic of a university hospital. The sample consisted of 114 elderly who reported foot pain. Data was collected through subsidized interview, using structured instrument, covering demographic variables and the Manchester Foot Pain and Disability Index in Elderly and the Mini Mental State Examination. Results: there was a high incidence of foot pain among women and young elderly as well as significant inability to perform certain daily activities. Conclusion: it is identified the need for special attention to the health of elderly reporting foot pain, since this tends to restrict daily activities, causing decreased quality of life, immobilization and possible episodes of falls.

  6. Physical rehabilitation of functional violations and deformations of children foot

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    Vykhliaiev Y. M.

    2014-03-01

    Full Text Available Purpose : To substantiate a comprehensive methodology for physical rehabilitation of children with functional disorder “hollow foot” in the initial stages of its development. Material : The study involved 58 children aged 8-14 years with the disorder and deformities of the lower extremities. Results : The changes after six months of targeting funds to rehabilitate musculoskeletal structures of the musculoskeletal system of experimental and control groups of children. The technique of rehabilitation, including: implementation of a specially designed set of corrective exercises, wearing special orthopedic individual insoles, foot massage and calf muscles, electro-stimulation effects on the musculoskeletal structure of the foot and lower leg dynamics. Conclusions : “hollow foot” is the least studied morphofunctional disorder; developed technique of physical rehabilitation for positive changes in the condition of the musculoskeletal system in children of the main group, the lack of specific rehabilitation interventions during the initial stages of the “hollow foot” leads to the aggravation of the disorder.

  7. Dynamic Foot Pressure as a Countermeasure to Muscle Atrophy

    Science.gov (United States)

    Kyparos, A.; Layne, C. S.; Martinez, D. A.; Clarke, M. S. F.; Feeback, D. L.

    2002-01-01

    Mechanical unloading of skeletal muscle (SKM) as a consequence of space flight or ground-based analogues, such as human bedrest and rodent hindlimb suspension (HLS) models, induces SKM atrophy particularly affecting the anti-gravity musculature of the lower limbs. In the context of manned space flight, the subsequent loss of muscle strength and functionality will pose operational implications jeopardizing mission success. Exercise, currently the primary muscle degradation countermeasure, has not proven completely effective in preventing muscle atrophy. It is therefore imperative that some other forms of in- flight countermeasure be also developed to supplement the prescribed exercise regimen the astronauts follow during spaceflight. Previous work in both humans and rats has shown that mechanical stimulation of the soles of the feet increases neuromuscular activation in the lower limb musculature and that such stimulation results in the limited prevention of atrophy in the soleus muscle of unloaded rats. This study was designed to investigate the effect of cutaneous mechanoreceptor stimulation on hindlimb unloading- induced SKM atrophy in rats. It was hypothesized that mechanical stimulation of the plantar surface of the rat foot during hindlimb suspension (HLS), utilizing a novel stimulation paradigm known as Dynamic Foot Pressure (DFP), would attenuate unloading-induced SKM atrophy. Mature adult male Wistar rats were randomly assigned to four groups of 10 rats each as follows: sedentary controls (Ctrl), hindlimb suspended only (HLS), hindlimb suspended wearing an inflatable boot (HLS-IFL) and hindlimb suspended rats wearing a non-inflatable boot (HLS-NIFL). The stimulation of mechanoreceptors was achieved by applying pressure to the plantar surface of the foot during the 10-day period of HLS using a custom-built boot. The anti-atrophic effects of DFP application was quantified directly by morphological (muscle wet weight, myofiber cross-sectional area

  8. In vitro study of foot kinematics using a dynamic walking cadaver model.

    Science.gov (United States)

    Nester, C J; Liu, A M; Ward, E; Howard, D; Cocheba, J; Derrick, T; Patterson, P

    2007-01-01

    There is a dearth of information on navicular, cuboid, cuneiform and metatarsal kinematics during walking and our objective was to study the kinematic contributions these bones might make to foot function. A dynamic cadaver model of walking was used to apply forces to cadaver feet and mobilise them in a manner similar to in vivo. Kinematic data were recorded from 13 cadaver feet. Given limitations to the simulation, the data describe what the cadaver feet were capable of in response to the forces applied, rather than exactly how they performed in vivo. The talonavicular joint was more mobile than the calcaneocuboid joint. The range of motion between cuneiforms and navicular was similar to that between talus and navicular. Metatarsals four and five were more mobile relative to the cuboid than metatarsals one, two and three relative to the cuneiforms. This work has confirmed the complexity of rear, mid and forefoot kinematics. The data demonstrate the potential for often-ignored foot joints to contribute significantly to the overall kinematic function of the foot. Previous emphasis on the ankle and sub talar joints as the principal articulating components of the foot has neglected more distal articulations. The results also demonstrate the extent to which the rigid segment assumptions of previous foot kinematics research have over simplified the foot.

  9. A dynamic finite element analysis of human foot complex in the sagittal plane during level walking.

    Science.gov (United States)

    Qian, Zhihui; Ren, Lei; Ding, Yun; Hutchinson, John R; Ren, Luquan

    2013-01-01

    The objective of this study is to develop a computational framework for investigating the dynamic behavior and the internal loading conditions of the human foot complex during locomotion. A subject-specific dynamic finite element model in the sagittal plane was constructed based on anatomical structures segmented from medical CT scan images. Three-dimensional gait measurements were conducted to support and validate the model. Ankle joint forces and moment derived from gait measurements were used to drive the model. Explicit finite element simulations were conducted, covering the entire stance phase from heel-strike impact to toe-off. The predicted ground reaction forces, center of pressure, foot bone motions and plantar surface pressure showed reasonably good agreement with the gait measurement data over most of the stance phase. The prediction discrepancies can be explained by the assumptions and limitations of the model. Our analysis showed that a dynamic FE simulation can improve the prediction accuracy in the peak plantar pressures at some parts of the foot complex by 10%-33% compared to a quasi-static FE simulation. However, to simplify the costly explicit FE simulation, the proposed model is confined only to the sagittal plane and has a simplified representation of foot structure. The dynamic finite element foot model proposed in this study would provide a useful tool for future extension to a fully muscle-driven dynamic three-dimensional model with detailed representation of all major anatomical structures, in order to investigate the structural dynamics of the human foot musculoskeletal system during normal or even pathological functioning.

  10. A dynamic finite element analysis of human foot complex in the sagittal plane during level walking.

    Directory of Open Access Journals (Sweden)

    Zhihui Qian

    Full Text Available The objective of this study is to develop a computational framework for investigating the dynamic behavior and the internal loading conditions of the human foot complex during locomotion. A subject-specific dynamic finite element model in the sagittal plane was constructed based on anatomical structures segmented from medical CT scan images. Three-dimensional gait measurements were conducted to support and validate the model. Ankle joint forces and moment derived from gait measurements were used to drive the model. Explicit finite element simulations were conducted, covering the entire stance phase from heel-strike impact to toe-off. The predicted ground reaction forces, center of pressure, foot bone motions and plantar surface pressure showed reasonably good agreement with the gait measurement data over most of the stance phase. The prediction discrepancies can be explained by the assumptions and limitations of the model. Our analysis showed that a dynamic FE simulation can improve the prediction accuracy in the peak plantar pressures at some parts of the foot complex by 10%-33% compared to a quasi-static FE simulation. However, to simplify the costly explicit FE simulation, the proposed model is confined only to the sagittal plane and has a simplified representation of foot structure. The dynamic finite element foot model proposed in this study would provide a useful tool for future extension to a fully muscle-driven dynamic three-dimensional model with detailed representation of all major anatomical structures, in order to investigate the structural dynamics of the human foot musculoskeletal system during normal or even pathological functioning.

  11. Can foot anthropometric measurements predict dynamic plantar surface contact area?

    Directory of Open Access Journals (Sweden)

    Collins Natalie

    2009-10-01

    Full Text Available Abstract Background Previous studies have suggested that increased plantar surface area, associated with pes planus, is a risk factor for the development of lower extremity overuse injuries. The intent of this study was to determine if a single or combination of foot anthropometric measures could be used to predict plantar surface area. Methods Six foot measurements were collected on 155 subjects (97 females, 58 males, mean age 24.5 ± 3.5 years. The measurements as well as one ratio were entered into a stepwise regression analysis to determine the optimal set of measurements associated with total plantar contact area either including or excluding the toe region. The predicted values were used to calculate plantar surface area and were compared to the actual values obtained dynamically using a pressure sensor platform. Results A three variable model was found to describe the relationship between the foot measures/ratio and total plantar contact area (R2 = 0.77, p R2 = 0.76, p Conclusion The results of this study indicate that the clinician can use a combination of simple, reliable, and time efficient foot anthropometric measurements to explain over 75% of the plantar surface contact area, either including or excluding the toe region.

  12. From flat foot to fat foot: structure, ontogeny, function, and evolution of elephant "sixth toes".

    Science.gov (United States)

    Hutchinson, John R; Delmer, Cyrille; Miller, Charlotte E; Hildebrandt, Thomas; Pitsillides, Andrew A; Boyde, Alan

    2011-12-23

    Several groups of tetrapods have expanded sesamoid (small, tendon-anchoring) bones into digit-like structures ("predigits"), such as pandas' "thumbs." Elephants similarly have expanded structures in the fat pads of their fore- and hindfeet, but for three centuries these have been overlooked as mere cartilaginous curiosities. We show that these are indeed massive sesamoids that employ a patchy mode of ossification of a massive cartilaginous precursor and that the predigits act functionally like digits. Further, we reveal clear osteological correlates of predigit joint articulation with the carpals/tarsals that are visible in fossils. Our survey shows that basal proboscideans were relatively "flat-footed" (plantigrade), whereas early elephantiforms evolved the more derived "tip-toed" (subunguligrade) morphology, including the predigits and fat pad, of extant elephants. Thus, elephants co-opted sesamoid bones into a role as false digits and used them for support as they changed their foot posture.

  13. The Influence of a Prefabricated Foot Orthosis on Lower Extremity Mechanics During Running in Individuals With Varying Dynamic Foot Motion.

    Science.gov (United States)

    Almonroeder, Thomas G; Benson, Lauren C; O'Connor, Kristian M

    2016-09-01

    Study Design Controlled laboratory study, cross-sectional. Background Orthotic prescription is often based on the premise that the mechanical effects will be more prominent in individuals with greater calcaneal eversion. Objective To compare the effects of a prefabricated foot orthosis on lower extremity kinematics and kinetics between recreational athletes with high and low calcaneal eversion during running. Methods Thirty-one recreational athletes were included in this study. Three-dimensional kinematic and kinetic data were collected while running with and without a foot orthosis. Participants were grouped based on the degree of calcaneal eversion during the running trials relative to a standing trial (dynamic foot motion). The effects of the orthosis on the frontal and transverse plane angles and moments of the hip and knee were compared between the 10 participants with the greatest and least amount of dynamic foot motion. Results There were no significant interactions (group by orthotic condition) for any of the kinematic or kinetic variables of interest. Conclusion The effects of an orthosis on the mechanics of the hip and knee do not appear to be dependent on an individual's dynamic foot motion. J Orthop Sports Phys Ther 2016;46(9):749-755. Epub 5 Aug 2016. doi:10.2519/jospt.2016.6253.

  14. Clinical and functional correlates of foot pain in diabetic patients.

    NARCIS (Netherlands)

    Rijken, P.M.; Dekker, J.; Rauwerda, J.A.; Dekker, E.; Lankhorst, G.J.; Bakker, K.; Dooren, J.

    1998-01-01

    Purpose: patients with diabetes mellitus frequently suffer from foot pain. This pain seems to be a neglected area in studies on the diabetic foot. The purpose of this study was to identify clinical variables associated with foot pain in diabetic patients. In addition, the relationships between foot

  15. Foot lengthening and shortening during gait: a parameter to investigate foot function?

    Science.gov (United States)

    Stolwijk, N M; Koenraadt, K L M; Louwerens, J W K; Grim, D; Duysens, J; Keijsers, N L W

    2014-02-01

    Based on the windlass mechanism theory of Hicks, the medial longitudinal arch (MLA) flattens during weight bearing. Simultaneously, foot lengthening is expected. However, changes in foot length during gait and the influence of walking speed has not been investigated yet. The foot length and MLA angle of 34 healthy subjects (18 males, 16 females) at 3 velocities (preferred, low (preferred -0.4 m/s) and fast (preferred +0.4 m/s) speed were investigated with a 3D motion analysis system (VICON(®)). The MLA angle was calculated as the angle between the second metatarsal head, the navicular tuberculum and the heel in the local sagittal plane. Foot length was calculated as the distance between the marker at the heel and the 2nd metatarsal head. A General Linear Model for repeated measures was used to indicate significant differences in MLA angle and foot length between different walking speeds. The foot lengthened during the weight acceptance phase of gait and shortened during propulsion. With increased walking speed, the foot elongated less after heel strike and shortened more during push off. The MLA angle and foot length curve were similar, except between 50% and 80% of the stance phase in which the MLA increases whereas the foot length showed a slight decrease. Foot length seems to represent the Hicks mechanism in the foot and the ability of the foot to bear weight. At higher speeds, the foot becomes relatively stiffer, presumably to act as a lever arm to provide extra propulsion. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Generation of subject-specific, dynamic, multisegment ankle and foot models to improve orthotic design: a feasibility study

    Directory of Open Access Journals (Sweden)

    Oosterwaal Michiel

    2011-11-01

    Full Text Available Abstract Background Currently, custom foot and ankle orthosis prescription and design tend to be based on traditional techniques, which can result in devices which vary greatly between clinicians and repeat prescription. The use of computational models of the foot may give further insight in the biomechanical effects of these devices and allow a more standardised approach to be taken to their design, however due to the complexity of the foot the models must be highly detailed and dynamic. Methods/Design Functional and anatomical datasets will be collected in a multicentre study from 10 healthy participants and 15 patients requiring orthotic devices. The patient group will include individuals with metarsalgia, flexible flat foot and drop foot. Each participant will undergo a clinical foot function assessment, 3D surface scans of the foot under different loading conditions, and detailed gait analysis including kinematic, kinetic, muscle activity and plantar pressure measurements in both barefoot and shod conditions. Following this each participant will undergo computed tomography (CT imaging of their foot and ankle under a range of loads and positions while plantar pressures are recorded. A further subgroup of participants will undergo magnetic resonance imaging (MRI of the foot and ankle. Imaging data will be segmented to derive the geometry of the bones and the orientation of the joint axes. Insertion points of muscles and ligaments will be determined from the MRI and CT-scans and soft tissue material properties computed from the loaded CT data in combination with the plantar pressure measurements. Gait analysis data will be used to drive the models and in combination with the 3D surface scans for scaling purposes. Predicted plantar pressures and muscle activation patterns predicted from the models will be compared to determine the validity of the models. Discussion This protocol will lead to the generation of unique datasets which will be used

  17. The reliability and validity of the Korean version of the foot function index for patients with foot complaints

    Science.gov (United States)

    In, Tae-Sung; Jung, Jin-Hwa; Kim, Keunjo; Jung, Kyoung-Sim; Cho, Hwi-Young

    2017-01-01

    [Purpose] The purpose of this study was to establish the reliability and validity of the Foot Function Index translated into Korean for use in patients with plantar fasciitis and foot/ankle fracture. [Subjects and Methods] Thirty-six subjects with foot complaints, 14 males and 22 females, participated in the study. Reliability was determined by using the intra-class correlation coefficient and Cronbach’s alpha for internal consistency. Validity was examined by correlating Foot Function Index scores with the Short Form-36 and the Visual Analog Scale scores. [Results] Test-retest reliability was 0.90 for the pain subscale, and 0.94 and 0.91 for the disability and activity limitation subscales, respectively. The criterion-related validity was established by comparison with the Korean version of the Short Form-36 and Visual Analog Scale. [Conclusion] The Korean version of the Foot Function Index was shown to be a reliable and valid instrument for assessing foot complaints. PMID:28210038

  18. Impact of Diabetes and Peripheral Arterial Occlusive Disease on the Functional Microcirculation at the Plantar Foot

    Directory of Open Access Journals (Sweden)

    Mohammad Kabbani, MD

    2013-10-01

    Conclusions: Functional microcirculation at the plantar foot differs between healthy subjects and patients suffering from diabetes or PAOD of the same age. Patients with either diabetes or PAOD demonstrate deteriorated cutaneous oxygen saturation with equivalent blood perfusion at the plantar foot. More clinical studies have to be conducted to evaluate therapeutical methods that might ameliorate cutaneous oxygen saturation within diabetic foot disease and PAOD.

  19. Foot lengthening and shortening during gait: a parameter to investigate foot function?

    NARCIS (Netherlands)

    Stolwijk, N.M.; Koenraadt, K.L.M.; Louwerens, J.W.; Grim, D.; Duysens, J.E.J.; Keijsers, N.L.W.

    2014-01-01

    INTRODUCTION: Based on the windlass mechanism theory of Hicks, the medial longitudinal arch (MLA) flattens during weight bearing. Simultaneously, foot lengthening is expected. However, changes in foot length during gait and the influence of walking speed has not been investigated yet. METHODS: The

  20. Foot lengthening and shortening during gait: a parameter to investigate foot function?

    NARCIS (Netherlands)

    Stolwijk, N.M.; Koenraadt, K.L.M.; Louwerens, J.W.; Grim, D.; Duysens, J.E.J.; Keijsers, N.L.W.

    2014-01-01

    INTRODUCTION: Based on the windlass mechanism theory of Hicks, the medial longitudinal arch (MLA) flattens during weight bearing. Simultaneously, foot lengthening is expected. However, changes in foot length during gait and the influence of walking speed has not been investigated yet. METHODS: The f

  1. Dynamic balance changes within three weeks of fitting a new prosthetic foot component.

    Science.gov (United States)

    Kent, Jenny A; Stergiou, Nicholas; Wurdeman, Shane R

    2017-07-05

    Balance during walking is of high importance to prosthesis users and may affect walking during baseline observation and evaluation. The aim of this study was to determine whether changes in walking balance occurred during an adaptation period following the fitting of a new prosthetic component. Margin of stability in the medial-lateral direction (MOSML) and an anterior instability margin (AIM) were used to quantify the dynamic balance of 21 unilateral transtibial amputees during overground walking. Participants trialled two prosthetic feet presenting contrasting movement/balance constraints; a Higher Activity foot similar to that of their own prosthesis, and a Lower Activity foot. Participants were assessed before (Visit 1) and after (Visit 2) a 3-week adaptation period on each foot. With the Higher Activity component, MOSML decreased on the prosthetic side, and increased on the sound side from Visit 1 to Visit 2, eliminating a significant inter-limb difference apparent at Visit 1 (Visit 1-sound=0.062m, prosthetic=0.075m, p=0.018; Visit 2-sound=0.066m, prosthetic=0.074m, p=0.084). No such change was seen with the Lower Activity foot (Visit 1-sound=0.064m, prosthetic=0.077m, p=0.007; Visit 2-sound=0.063m, prosthetic=0.080m, pbalance during walking can occur following the initial receipt of a device regardless of whether the component is of the same functional category as the one an individual is accustomed to using. Copyright © 2017. Published by Elsevier B.V.

  2. A Phase-Dependent Hypothesis for Locomotor Functions of Human Foot Complex

    Institute of Scientific and Technical Information of China (English)

    Lei Ren; David Howard; Lu-quan Ren; Chris Nester; Li-mei Tian

    2008-01-01

    The human foot is a very complex structure comprising numerous bones, muscles, ligaments and synovial joints. As the only component in contact with the ground, the foot complex delivers a variety of biomechanical functions during human locomotion, e.g. body support and propulsion, stability maintenance and impact absorption. These need the human foot to be rigid and damped to transmit ground reaction forces to the upper body and maintain body stability, and also to be compliant and resilient to moderate risky impacts and save energy. How does the human foot achieve these apparent conflicting functions? In this study, we propose a phase-dependent hypothesis for the overall locomotor functions of the human foot complex based on in-vivo measurements of human natural gait and simulation results of a mathematical foot model. We propse that foot functions are highly dependent on gait phase, which is a major characteristics of human locomotion. In early stance just after heel strike,the foot mainly works as a shock absorber by moderating high impacts using the viscouselastic heel pad in both. vertical and horizontal directions. In mid-stance phase(~80% of stance phase), the foot complex can be considered as a springy rocker,reserving external mechanical work using the foot arch whilst moving ground contact point forward along a curved path to maintain body stability. In late stance after heel off, the foot complex mainly serves as a force modulator like a gear box,modulating effective mechanical advantages of ankle plantiflexor muscles using metatarsal-phalangeal joints. A sound understanding of how diverse functions are implemented in a simple foot segment during human locomotion might be useful to gain insight into the overall foot locomotor functions and hence to facilitate clinical diagnosis, rehabilitation product design and humanoid robot development.

  3. Frontal plane multi-segment foot kinematics in high- and low-arched females during dynamic loading tasks.

    Science.gov (United States)

    Powell, Douglas W; Long, Benjamin; Milner, Clare E; Zhang, Songning

    2011-02-01

    The functions of the medial longitudinal arch have been the focus of much research in recent years. Several studies have shown kinematic differences between high- and low-arched runners. No literature currently compares the inter-segmental foot motion of high- and low-arched recreational athletes. The purpose of this study was to examine inter-segmental foot motion in the frontal plane during dynamic loading activities in high- and low-arched female athletes. Inter-segmental foot motions were examined in 10 high- and 10 low-arched female recreational athletes. Subjects performed five barefooted trials in each of the following randomized movements: walking, running, downward stepping and landing. Three-dimensional kinematic data were recorded. High-arched athletes had smaller peak ankle eversion angles in walking, running and downward stepping than low-arched athletes. At the rear-midfoot joint high-arched athletes reached peak eversion later in walking and downward stepping than the low-arched athletes. The high-arched athletes had smaller peak mid-forefoot eversion angles in walking, running and downward stepping than the low-arched athletes. The current findings show that differences in foot kinematics between the high- and low-arched athletes were in position and not range of motion within the foot.

  4. An Investigation of Structure, Flexibility, and Function Variables that Discriminate Asymptomatic Foot Types.

    Science.gov (United States)

    Shultz, Sarah P; Song, Jinsup; Kraszewski, Andrew P; Hafer, Jocelyn F; Rao, Smita; Backus, Sherry; Hillstrom, Rajshree M; Hillstrom, Howard J

    2017-07-01

    It has been suggested that foot type considers not only foot structure (high, normal, low arch), but also function (overpronation, normal, oversupination) and flexibility (reduced, normal, excessive). Therefore, this study used canonical regression analyses to assess which variables of foot structure, function, and flexibility can accurately discriminate between clinical foot type classifications. The feet of 61 asymptomatic, healthy adults (18-77 years) were classified as cavus (N = 24), rectus (N = 54), or planus (N = 44) using standard clinical measures. Custom jigs assessed foot structure and flexibility. Foot function was assessed using an emed-x plantar pressure measuring device. Canonical regression analyses were applied separately to extract essential structure, flexibility, and function variables. A third canonical regression analysis was performed on the extracted variables to identify a combined model. The initial combined model included 30 extracted variables; however 5 terminal variables (malleolar valgus index, arch height index while sitting, first metatarsophalangeal joint laxity while standing, pressure-time integral and maximum contact area of medial arch) were able to correctly predict 80.7% of foot types. These remaining variables focused on specific foot characteristics (hindfoot alignment, arch height, midfoot mechanics, Windlass mechanism) that could be essential to discriminating foot type.

  5. Shoes alter the spring-like function of the human foot during running.

    Science.gov (United States)

    Kelly, Luke A; Lichtwark, Glen A; Farris, Dominic J; Cresswell, Andrew

    2016-06-01

    The capacity to store and return energy in legs and feet that behave like springs is crucial to human running economy. Recent comparisons of shod and barefoot running have led to suggestions that modern running shoes may actually impede leg and foot-spring function by reducing the contributions from the leg and foot musculature. Here we examined the effect of running shoes on foot longitudinal arch (LA) motion and activation of the intrinsic foot muscles. Participants ran on a force-instrumented treadmill with and without running shoes. We recorded foot kinematics and muscle activation of the intrinsic foot muscles using intramuscular electromyography. In contrast to previous assertions, we observed an increase in both the peak (flexor digitorum brevis +60%) and total stance muscle activation (flexor digitorum brevis +70% and abductor hallucis +53%) of the intrinsic foot muscles when running with shoes. Increased intrinsic muscle activation corresponded with a reduction in LA compression (-25%). We confirm that running shoes do indeed influence the mechanical function of the foot. However, our findings suggest that these mechanical adjustments are likely to have occurred as a result of increased neuromuscular output, rather than impaired control as previously speculated. We propose a theoretical model for foot-shoe interaction to explain these novel findings. © 2016 The Author(s).

  6. Analysis of dynamic foot pressure distribution and ground reaction forces

    Science.gov (United States)

    Ong, F. R.; Wong, T. S.

    2005-04-01

    The purpose of this study was to assess the relationship between forces derived from in-shoe pressure distribution and GRFs during normal gait. The relationship served to demonstrate the accuracy and reliability of the in-shoe pressure sensor. The in-shoe pressure distribution from Tekscan F-Scan system outputs vertical forces and Centre of Force (COF), while the Kistler force plate gives ground reaction forces (GRFs) in terms of Fz, Fx and Fy, as well as vertical torque, Tz. The two systems were synchronized for pressure and GRFs measurements. Data was collected from four volunteers through three trials for both left and right foot under barefoot condition with the in-shoe sensor. The forces derived from pressure distribution correlated well with the vertical GRFs, and the correlation coefficient (r2) was in the range of 0.93 to 0.99. This is a result of extended calibration, which improves pressure measurement to give better accuracy and reliability. The COF from in-shoe sensor generally matched well with the force plate COP. As for the maximum vertical torque at the forefoot during toe-off, there was no relationship with the pressure distribution. However, the maximum torque was shown to give an indication of the rotational angle of the foot.

  7. Flat foot functional evaluation using pattern recognition of ground reaction data.

    Science.gov (United States)

    Bertani, A; Cappello, A; Benedetti, M G; Simoncini, L; Catani, F

    1999-08-01

    Main purpose of this study was to apply quantitative gait analysis and statistical pattern recognition as clinical decision-making aids in flat foot diagnosis and post-surgery monitoring. Statistical pattern recognition techniques were applied to discriminate between normal and flat foot populations through ground reaction force measurements; ground reaction forces time course was assumed as a sensible index of the foot function. Gait analysis is becoming recognized as an important clinical tool in orthopaedics, in pre-surgery planning, post-surgery monitoring and in a posteriori evaluation of different treatment techniques. Statistical pattern recognition techniques have been utilized with success in this field to identify the most significant variables of selected motor functions in different pathologies, and to design classification rules and quantitative evaluation scores. Ground reaction forces were recorded during free speed barefoot walks on 28 healthy subjects, and 28 symptomatic flexible flat foot children selected for surgical intervention. A new feature selection algorithm, based on heuristic optimization, was applied to select the most discriminant ground reaction forces time samples. A two-stage pattern recognition system, composed by three linear feature extractors, one for each ground reaction force component, and a linear classifier, was designed to classify the feet of each subject using the selected features. The output of the classifier was used to define a functional score. The classifier assigned the ground reaction force patterns performed by each subject into the right class with an estimated error of 15%, corresponding to an assignment error for each subject's foot of 9%. The most discriminant ground reaction forces time samples selected are in full agreement with the pathophysiology of the symptomatic flexible flat foot. The obtained score was utilized to monitor the 1 and 2 years post-operative functional recovery of two differently

  8. Movement of the human foot in 100 pain free individuals aged 18–45: implications for understanding normal foot function

    OpenAIRE

    Nester, Christopher J; Jarvis, Hannah L; Jones, Richard K; Bowden, Peter D; Liu, Anmin

    2014-01-01

    Background Understanding motion in the normal healthy foot is a prerequisite for understanding the effects of pathology and thereafter setting targets for interventions. Quality foot kinematic data from healthy feet will also assist the development of high quality and research based clinical models of foot biomechanics. To address gaps in the current literature we aimed to describe 3D foot kinematics using a 5 segment foot model in a population of 100 pain free individuals. Methods Kinematics...

  9. Foot force models of crowd dynamics on a wobbly bridge

    CERN Document Server

    Belykh, Igor; Belykh, Vladamir

    2016-01-01

    Modern pedestrian and suspension bridges are designed using industry-standard packages, yet disastrous resonant vibrations are observed, necessitating multi-million dollar repairs. Recent examples include pedestrian induced vibrations during the openings of the Solf\\'erino Bridge in Paris in 1999 and the increased bouncing of the Squibb Park Bridge in Brooklyn in 2014. The most prominent example of an unstable lively bridge is the London Millennium Bridge which started wobbling as a result of pedestrian-bridge interactions. Pedestrian phase-locking due to footstep phase adjustment, is suspected to be the main cause of its large lateral vibrations; however, its role in the initiation of wobbling was debated. In this paper, we develop foot force models of pedestrians' response to bridge motion and detailed, yet analytically tractable models of crowd phase-locking. We use bio-mechanically inspired models of crowd lateral movement to investigate to what degree pedestrian synchrony must be present for a bridge to ...

  10. Intermittent foot claudication caused by a dynamic compression of the posterior tibial artery.

    Science.gov (United States)

    Kaczynski, Jakub; Topliss, Claire; Fligelstone, Louis

    2016-07-14

    A young adult presented with an atypical intermittent foot claudication caused by a dynamic compression of the posterior tibial artery by a ganglion. This case highlights the diagnostic challenges when dealing with an entrapment syndrome. Subsequent open surgical treatment was successful, and the patient has made a good recovery.

  11. Discrete Wigner function dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Klimov, A B; Munoz, C [Departamento de Fisica, Universidad de Guadalajara, Revolucion 1500, 44410, Guadalajara, Jalisco (Mexico)

    2005-12-01

    We study the evolution of the discrete Wigner function for prime and the power of prime dimensions using the discrete version of the star-product operation. Exact and semiclassical dynamics in the limit of large dimensions are considered.

  12. Assessment of foot impairment in rheumatoid arthritis patients by dynamic pedobarography.

    Science.gov (United States)

    Schmiegel, Andreas; Rosenbaum, Dieter; Schorat, Annette; Hilker, Arvid; Gaubitz, Markus

    2008-01-01

    Impaired foot function may jeopardize the mobility of patients with rheumatoid arthritis (RA). However, there are still no guidelines concerning the adequate early treatment of painful rheumatoid feet which do not yet require surgery. An assessment method for RA feet appears necessary in order to detect foot problems before functional limitations develop. Therefore, the aim of the present study was to evaluate the use of pedobarographic measurements for detecting changes in plantar loading characteristics and their relationship to foot pain in patients with RA. One hundred and twelve patients with RA (55.0+/-11.0 years of age) were divided into three groups according to their Health Assessment Questionnaire (HAQ) Score and compared to a control group of 20 healthy adults (CG). Thirty-six patients with good physical capacity belonged to group 1 (RA1; HAQ-score: 0-1.0), 38 patients with moderate capacity to group 2 (RA2; score: 1.1-2.0) and 38 patients with low capacity to group 3 (RA3; score: 2.1-3.0). Each patient's foot pain was clinically assessed. Pedobarography was used to analyze foot loading parameters while walking barefoot. In the forefoot, average pressures under the lateral forefoot were higher in RA1 patients than in RA2 patients and controls (phead (p<0.05). In contrast, no significant differences in maximum force could be demonstrated between patient groups. Furthermore, in RA3 patients with lower physical capacity, foot pain was increased as compared to RA1 and RA2 patients. In RA patients, pedobarographic patterns show specific changes which characterize the level of functional capacity. In patients with foot involvement, pedobarographic measurements can be useful during the earlier stages of the disease, when clinical examination does not yet indicate the need for more aggressive treatment or orthopedic interventions.

  13. Low Power Dynamic Logic Ripple Carry Adder Using Footed Diode Domino Logic

    Directory of Open Access Journals (Sweden)

    P. Krishna Karthik

    2014-03-01

    Full Text Available In recent electronic devices power saving has more importance than any other thing. Dynamic logic circuits are one of the basic power efficient circuits which comes into picture when dealt with low power. Dynamic logic circuits operate mainly in two phases, namely Pre-charge and evaluate phase. Domino logic circuits are more power efficient and cooperatively faster circuits which operate on the above two phases. For extremely low power applications footed diode domino logic is applied. This paper mainly deals with design of Dynamic logic circuit design based on footed diode domino logic with reduction in power and leakage current. In this proposed circuit we put a diode on the foot of domino logic circuit which results in power reduction as compared to reported and conventional domino logic. We are using NMOS as a diode and due to this extra diode (NMOS, in pre-charge period leakage current reduce due to stacking effect. Approximately 32% of power is saved using footed diode domino logic. For Simulation we are using tanner tool at 180nm technology.

  14. Validation of a Russian-language version of the Foot Functional Index (FFI questionnaire

    Directory of Open Access Journals (Sweden)

    E. V. Orlova

    2016-01-01

    Full Text Available The Foot Functional Index (FFI questionnaire most completely reflects the functional status of patients with joint diseases of the feet.Objective: to study the psychometric properties of a Russian-language version of the FFI questionnaire.Patients and methods. The reliability, sensitivity, and validity of the Russian-language version of the FFI questionnaire were assessed in 55 patients with rheumatoid arthritis (RA. The investigators checked the reliability by assessing the internal consistency (calculating Cronbach's alpha and reproducibility by a test-retest analysis. The criterion validity was evaluated by correlation analysis using HAQ, RAPID3, and pain visual analogue scale (VAS scores. The sensitivity of FFI was studied by comparing its dynamics with RAPID3 changes during treatment.Results. Evaluating the internal consistency yielded a high Cronbach's alpha (0.78. The test-retest analysis demonstrated a significant correlation (0.83 between the results of primary and secondary testing. Assessing the criterion validity showed a high or near-high relationship to the scores of RAPID3 (0.78, HAQ (0.69, and pain VAS (0.76. The group of patients who were observed to have a decrease in disease activity according to RAPID3 from a high (16.2±4.1 to moderate (10.5±5.2 degree displayed a more marked reduction in FFI (ΔFFI = 20.5±2.3 than the group that did not exhibit significant changes in disease activity (ΔFFI = 6.9±3.4.Conclusion. FFI is a reliable, valid, and sensitive tool to evaluate the functional status of patients with foot diseases in RA.

  15. Analysis of Foot Slippage Effects on an Actuated Spring-mass Model of Dynamic Legged Locomotion

    Directory of Open Access Journals (Sweden)

    Yizhar Or

    2016-04-01

    Full Text Available The classical model of spring-loaded inverted pendulum (SLIP and its extensions have been widely accepted as a simple description of dynamic legged locomotion at various scales in humans, legged robots and animals. Similar to the majority of models in the literature, the SLIP model assumes ideal sticking contact of the foot. However, there are practical scenarios of low ground friction that causes foot slippage, which can have a significant influence on dynamic behaviour. In this work, an extension of the SLIP model with two masses and torque actuation is considered, which accounts for possible slippage under Coulomb’s friction law. The hybrid dynamics of this model is formulated and numerical simulations under representative parameter values reveal several types of stable periodic solutions with stick slip transitions. Remarkably, it is found that slippage due to low friction can sometimes increase average speed and improve energetic efficiency by significantly reducing the mechanical cost of transport.

  16. Dynamic Characteristics of Prosthetic Feet: A Comparison Between Modal Parameters of Walking, Running and Sprinting Foot

    Science.gov (United States)

    Noroozi, S.; Rahman, A. G. A.; Dupac, M.; Vinney, J. E.

    Current methods of evaluating the performance of Energy Storing and Returning (ESR) prosthesis are subjective and rely on VO2 consumption. Current prosthetic feet are designed for specific applications and the majority are designed for walking and moderate running. These mechanical feet have fixed mechanical and dynamic characteristics. They have to be selected to meet the requirement of the task and any use outside the domain of the task can result in extreme/severe lack of gait symmetry and loss of energy. Poor gait symmetry results is excess consumption of energy, back pain or fatigue. To investigate if a multipurpose foot can be designed to passively adapt to the walking or running condition one must first understand the different dynamics that are involved and are required from the task specific foot. Static tests have shown these feet to have non-linear stiffness, making the prediction of their dynamic response difficult. The most reliable method to test for dynamic characteristics is drop and modal testing. A method approach has been developed as part of this research to test and compare the dynamic characteristics of three different types of foot (natural frequency, mode shapes and damping). This is needed to explore the differences in the responses of these feet that allow one to be used for walking, one to be used for running and one to be used for sprinting with ease.

  17. Data Reduction Functions for the Langley 14- by 22-Foot Subsonic Tunnel

    Science.gov (United States)

    Boney, Andy D.

    2014-01-01

    The Langley 14- by 22-Foot Subsonic Tunnel's data reduction software utilizes six major functions to compute the acquired data. These functions calculate engineering units, tunnel parameters, flowmeters, jet exhaust measurements, balance loads/model attitudes, and model /wall pressures. The input (required) variables, the output (computed) variables, and the equations and/or subfunction(s) associated with each major function are discussed.

  18. Reliability and Correlation of Static and Dynamic Foot Arch Measurement in a Healthy Pediatric Population.

    Science.gov (United States)

    Scholz, Timo; Zech, Astrid; Wegscheider, Karl; Lezius, Susanne; Braumann, Klaus-Michael; Sehner, Susanne; Hollander, Karsten

    2017-07-14

    Measurement of the medial longitudinal foot arch in children is a controversial topic, as there are many different methods without a definite standard procedure. The purpose of this study was to 1) investigate intraday and interrater reliability regarding dynamic arch index and static arch height, 2) explore the correlation between both arch indices, and 3) examine the variation of the medial longitudinal arch at two different times of the day. Eighty-six children (mean ± SD age, 8.9 ± 1.9 years) participated in the study. Dynamic footprint data were captured with a pedobarographic platform. For static arch measurements, a specially constructed caliper was used to assess heel-to-toe length and dorsum height. A mixed model was established to determine reliability and variation. Reliability was found to be excellent for the static arch height index in sitting (intraday, 0.90; interrater, 0.80) and standing positions (0.88 and 0.85) and for the dynamic arch index (both 1.00). There was poor correlation between static and dynamic assessment of the medial longitudinal arch (standing dynamic arch index, r = -0.138; sitting dynamic arch index, r = -0.070). Static measurements were found to be significantly influenced by the time of day (P static arch height index is influenced by gender (P = .004), whereas dynamic arch index is influenced by side (P = .011) and body mass index (P static foot measurements are reliable for medial longitudinal foot arch assessment in children. The variation of static arch measurements during the day has to be kept in mind. For clinical purposes, static and dynamic arch data should be interpreted separately.

  19. The Multi-Functional Foot in Athletic Movement: Extraordinary Feats by Our Extraordinary Feet

    Directory of Open Access Journals (Sweden)

    Wilson Jennifer

    2016-03-01

    Full Text Available The unique architecture of the foot system provides a sensitive, multi-tensional method of communicating with the surrounding environment. Within the premise of the paper, we discuss three themes: complexity, degeneracy and bio-tensegrity. Complex structures within the foot allow the human movement system to negotiate strategies for dynamic movement during athletic endeavours. We discuss such complex structures with particular attention to properties of a bio-tensegrity system. Degeneracy within the foot structure offers a distinctive solution to the problems posed by differing terrains and uneven surfaces allowing lower extremity structures to overcome perturbation as and when it occurs. This extraordinary structure offers a significant contribution to bipedalism through presenting a robust base of support and as such, should be given more consideration when designing athletic development programmes.

  20. Plantar Pressure Distribution among Older Persons with Different Types of Foot and Its Correlation with Functional Reach Distance

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    Aisyah Mohd Said

    2016-01-01

    Full Text Available Background. Changes in biomechanical structures of human foot are common in the older person, which may lead to alteration of foot type and plantar pressure distribution. We aimed to examine how foot type affects the plantar pressure distribution and to determine the relationship between plantar pressure distribution and functional reach distance in older persons. Methods. Fifty community-dwelling older persons (age: 69.98±5.84 were categorized into three groups based on the Foot Posture Index. The plantar pressure (max⁡P and contact area were analyzed using Footscan® RSScan platform. The Kruskal-Wallis test was used to compare the plantar pressure between foot types and Spearman’s correlation coefficient was used to correlate plantar pressure with the functional reach distance. Results. There were significant differences of max⁡P in the forefoot area across all foot types. The post hoc analysis found significantly lower max⁡P in the pronated foot compared to the supinated foot. A high linear rank correlation was found between functional reach distance and max⁡P of the rearfoot region of the supinated foot. Conclusions. These findings suggested that types of the foot affect the plantar maximal pressure in older persons with functional reach distance showing some associations.

  1. Foot pain and functional limitation in healthy adults with hallux valgus: a cross-sectional study

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    Nix Sheree E

    2012-10-01

    Full Text Available Abstract Background Hallux valgus (HV is a very common deformity of the first metatarsophalangeal joint that often requires surgical correction. However, the association between structural HV deformity and related foot pain and disability is unclear. Furthermore, no previous studies have investigated concerns about appearance and difficulty with footwear in a population with HV not seeking surgical correction. The aim of this cross-sectional study was to investigate foot pain, functional limitation, concern about appearance and difficulty with footwear in otherwise healthy adults with HV compared to controls. Methods Thirty volunteers with HV (radiographic HV angle >15 degrees and 30 matched controls were recruited for this study (50 women, 10 men; mean age 44.4 years, range 20 to 76 years. Differences between groups were examined for self-reported foot pain and disability, satisfaction with appearance, footwear difficulty, and pressure-pain threshold at the first metatarsophalangeal joint. Functional measures included balance tests, walking performance, and hallux muscle strength (abduction and plantarflexion. Mean differences (MD and 95% confidence intervals (CI were calculated. Results All self-report measures showed that HV was associated with higher levels of foot pain and disability and significant concerns about appearance and footwear (p Conclusions These findings show that HV negatively impacts on self-reported foot pain and function, and concerns about foot appearance and footwear in otherwise healthy adults. There was also evidence of impaired hallux muscle strength and increased postural sway in HV subjects compared to controls, although general physical functioning and participation in physical activity were not adversely affected.

  2. Evaluation of a patient-specific cost function to predict the influence of foot path on the knee adduction torque during gait.

    Science.gov (United States)

    Fregly, Benjamin J; Reinbolt, Jeffery A; Chmielewski, Terese L

    2008-02-01

    A large external knee adduction torque during gait has been correlated with the progression of knee osteoarthritis (OA). Though foot path changes (e.g. toeing out) can reduce the adduction torque, no method currently exists to predict whether an optimal foot path exists for a specific patient. This study evaluates a patient-specific optimization cost function to predict how foot path changes influence both adduction torque peaks. Video motion and ground reaction data were collected from a patient with knee OA performing normal, toe out, and wide stance gait. Joint and inertial parameters in a dynamic, 27 degree-of-freedom, full-body gait model were calibrated to the patient's normal gait data. The model was then used in gait optimizations that predicted how the patient's adduction torque peaks would change due to changes in foot path. The cost function tracked the patient's normal gait data using weight factors calibrated to toe out gait and tested using wide stance gait. For both gait motions, the same cost function weights predicted the change in both adduction torque peaks to within 7% error. With further development, this approach may eventually permit the design of patient-specific rehabilitation procedures such as an optimal foot path for patients with knee OA.

  3. Modifying the Functional Movement Screen Deep Squat Test: The Effect of Foot and Arm Positional Variations.

    Science.gov (United States)

    McMillian, Danny J; Rynders, Zach G; Trudeau, Tyler R

    2016-04-01

    The functional movement screen (FMS) was developed as an evaluation tool for assessing the fundamental movement patterns believed to be prerequisites for functional activity. However, some of the FMS component movements, such as the deep overhead squat test (DST), likely represent novel motor challenges on which poor performance might reflect inexperience with the task rather than a movement impairment. The purpose of this study was to examine the effects of positional variations on DST scores in a population of young, healthy adults. We hypothesized that self-selecting foot positioning, removal of an overhead component, or changing both aspects of the DST would result in improvement in FMS scores. Twenty healthy subjects completed 4 squatting conditions in a counterbalanced sequence to eliminate carry over effects: DST, modified squat with hands at chest level and feet in the DST position (DSTO), modified squat with arms in the DST position and self-selected foot placement (DSTF), and modified squat with hands at chest level and self-selected foot placement (DSTB). A Friedman's analysis of variance and Wilcoxon signed-ranks' post hoc analysis revealed a significant difference between all squat conditions (p = 0.036), between DSTB-DST groups (p DST groups (p = 0.004), and DSTO-DSTB groups (p = 0.046). Each modified squat condition had an average score higher than the DST. These findings suggest that the FMS DST might underestimate an individual's ability to squat during functional tasks that involve self-selected foot and arm placement.

  4. Dynamic 3D shape of the plantar surface of the foot using coded structured light: a technical report

    KAUST Repository

    Thabet, Ali Kassem

    2014-01-23

    Background The foot provides a crucial contribution to the balance and stability of the musculoskeletal system, and accurate foot measurements are important in applications such as designing custom insoles/footwear. With better understanding of the dynamic behavior of the foot, dynamic foot reconstruction techniques are surfacing as useful ways to properly measure the shape of the foot. This paper presents a novel design and implementation of a structured-light prototype system providing dense three dimensional (3D) measurements of the foot in motion. The input to the system is a video sequence of a foot during a single step; the output is a 3D reconstruction of the plantar surface of the foot for each frame of the input. Methods Engineering and clinical tests were carried out to test the accuracy and repeatability of the system. Accuracy experiments involved imaging a planar surface from different orientations and elevations and measuring the fitting errors of the data to a plane. Repeatability experiments were done using reconstructions from 27 different subjects, where for each one both right and left feet were reconstructed in static and dynamic conditions over two different days. Results The static accuracy of the system was found to be 0.3 mm with planar test objects. In tests with real feet, the system proved repeatable, with reconstruction differences between trials one week apart averaging 2.4 mm (static case) and 2.8 mm (dynamic case). Conclusion The results obtained in the experiments show positive accuracy and repeatability results when compared to current literature. The design also shows to be superior to the systems available in the literature in several factors. Further studies need to be done to quantify the reliability of the system in clinical environments.

  5. Evaluation Of Gait Symmetry In Amputees Who Use Below Knee Prosthesis With Dynamic Foot

    Directory of Open Access Journals (Sweden)

    Yasin Yurt

    2012-06-01

    Full Text Available Purpose: To assess inter limb symmetry while walking in unilateral transtibial amputees which use dynamic foot. Method: Gait velocity, cadence, step length, stance percentages and ambulation index results of amputees (n=20 were recorded. Comparison was made with control group. (n=21 Results: Gait velocity, cadence and ambulation index results were greater for control group. Cases had longer stance time on their intact limb than amputated side. Stance time difference between limbs were higher for amputee group than control group. Conclusion: Amputees had higher stance percentage on their intact limb than sound limb with regard to healthy people.

  6. Non-contact continuous-wave diffuse optical tomographic system to capture vascular dynamics in the foot

    Science.gov (United States)

    Hoi, Jennifer W.; Kim, Hyun K.; Khalil, Michael A.; Fong, Christopher J.; Marone, Alessandro; Shrikhande, Gautam; Hielscher, Andreas H.

    2015-03-01

    Dynamic optical tomographic imaging has shown promise in diagnosing and monitoring peripheral arterial disease (PAD), which affects 8 to 12 million in the United States. PAD is the narrowing of the arteries that supply blood to the lower extremities. Prolonged reduced blood flow to the foot leads to ulcers and gangrene, which makes placement of optical fibers for contact-based optical tomography systems difficult and cumbersome. Since many diabetic PAD patients have foot wounds, a non-contact interface is highly desirable. We present a novel non-contact dynamic continuous-wave optical tomographic imaging system that images the vasculature in the foot for evaluating PAD. The system images at up to 1Hz by delivering 2 wavelengths of light to the top of the foot at up to 20 source positions through collimated source fibers. Transmitted light is collected with an electron multiplying charge couple device (EMCCD) camera. We demonstrate that the system can resolve absorbers at various locations in a phantom study and show the system's first clinical 3D images of total hemoglobin changes in the foot during venous occlusion at the thigh. Our initial results indicate that this system is effective in capturing the vascular dynamics within the foot and can be used to diagnose and monitor treatment of PAD in diabetic patients.

  7. Problems related to functioning and quality of life of patients with diabetic foot ulcers

    Directory of Open Access Journals (Sweden)

    Grażyna R. Wiraszka

    2013-12-01

    Full Text Available Nowadays, diabetes constitutes a significant medical, social and economic problem. According to the World Health Organization in 2025 the incidence of this disease will double in both developed and developing countries. Incidence of diabetes in Poland is 2–5% depending on the region. This disease leads to numerous restrictions in patient functioning. The need for continuous therapy and medical supervision as well as various complications exert a negative influence on the quality of life (QOL in this group of patients. One of those complications – the diabetic foot – is a particularly important problem. In many cases it leads to foot ulceration and, in consequence, amputation. These unfavorable aftermaths of diabetes not only cause limitations in physical functioning, but also negatively influence patients’ psychosocial functioning and require multidisciplinary support from a therapeutic care team.

  8. Functional Assessment of the Foot Undergoing Percutaneous Achilles Tenotomy in Term of Gait Analysis

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    Yu-Bin Liu

    2016-01-01

    Full Text Available Background. This study was designed to evaluate the function of the foot undergoing the procedure of percutaneous Achilles tenotomy (PAT in case of clubfoot management in terms of gait analysis. Methods. Nineteen patients with unilateral clubfeet were retrospectively reviewed from our database from July 2012 to June 2016. The result in all the cases was rated as excellent according to the scale of International Clubfoot Study Group (ICSG. The affected sides were taken as Group CF and the contralateral sides as Group CL. Three-dimensional gait analysis was applied for the functional evaluation of the involved foot. Results. Statistical difference was found in physical parameters of passive ankle dorsiflexion and plantar-flexion. No statistical difference was found in temporal-spatial parameters. There was statistical difference in kinematic parameters of total ankle rotation, ankle range of motion, and internal foot progression angle and in kinetic parameters of peak ankle power. No statistical difference was found in other kinematic and kinetic parameters. Conclusions. It is demonstrated that the procedure of PAT is safe and efficient for correcting the equinus deformity in case of clubfoot management and preserving the main function of Achilles tendon at the minimum of four-year follow-up.

  9. Feasibility of using Lokomat combined with functional electrical stimulation for the rehabilitation of foot drop

    Directory of Open Access Journals (Sweden)

    Christian B. Laursen

    2016-08-01

    Full Text Available This study investigated the clinical feasibility of combining the electromechanical gait trainer Lokomat with functional electrical therapy (LokoFET, stimulating the common peroneal nerve during the swing phase of the gait cycle to correct foot drop as an integrated part of gait therapy. Five patients with different acquired brain injuries trained with LokoFET 2-3 times a week for 3-4 weeks. Pre- and post-intervention evaluations were performed to quantify neurophysiological changes related to the patients’ foot drop impairment during the swing phase of the gait cycle. A semi-structured interview was used to investigate the therapists’ acceptance of LokoFET in clinical practice. The patients showed a significant increase in the level of activation of the tibialis anterior muscle and the maximal dorsiflexion during the swing phase, when comparing the pre- and post-intervention evaluations. This showed an improvement of function related to the foot drop impairment. The interview revealed that the therapists perceived the combined system as a useful tool in the rehabilitation of gait. However, lack of muscle selectivity relating to the FES element of LokoFET was assessed to be critical for acceptance in clinical practice.

  10. Foot deformities, function in the lower extremities, and plantar pressure in patients with diabetes at high risk to develop foot ulcers

    Directory of Open Access Journals (Sweden)

    Ulla Hellstrand Tang

    2015-06-01

    Full Text Available Objective: Foot deformities, neuropathy, and dysfunction in the lower extremities are known risk factors that increase plantar peak pressure (PP and, as a result, the risk of developing foot ulcers in patients with diabetes. However, knowledge about the prevalence of these factors is still limited. The aim of the present study was to describe the prevalence of risk factors observed in patients with diabetes without foot ulcers and to explore possible connections between the risk factors and high plantar pressure. Patients and methods: Patients diagnosed with type 1 (n=27 or type 2 (n=47 diabetes (mean age 60.0±15.0 years were included in this cross-sectional study. Assessments included the registration of foot deformities; test of gross function at the hip, knee, and ankle joints; a stratification of the risk of developing foot ulcers according to the Swedish National Diabetes Register; a walking test; and self-reported questionnaires including the SF-36 health survey. In-shoe PP was measured in seven regions of interests on the sole of the foot using F-Scan®. An exploratory analysis of the association of risk factors with PP was performed. Results: Neuropathy was present in 28 (38%, and 39 (53% had callosities in the heel region. Low forefoot arch was present in 57 (77%. Gait-related parameters, such as the ability to walk on the forefoot or heel, were normal in all patients. Eighty percent had normal function at the hip and ankle joints. Gait velocity was 1.2±0.2 m/s. All patients were stratified to risk group 3. Hallux valgus and hallux rigidus were associated with an increase in the PP in the medial forefoot. A higher body mass index (BMI was found to increase the PP at metatarsal heads 4 and 5. Pes planus was associated with a decrease in PP at metatarsal head 1. Neuropathy did not have a high association with PP. Conclusions: This study identified several potential risk factors for the onset of diabetic foot ulcers (DFU. Hallux valgus

  11. Effect of dynamic temperature stimulus to plantar surface of the foot in the standing position

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    Ryo Watanabe

    2016-11-01

    Full Text Available We have previously found that a vertical force or tactile sensation occurs when the temperature of a participant's skin changes rapidly. In this illusion, upward motion, pressure or force sensation is elicited when stimulus temperature rises rapidly, whereas in the opposite case, downward motion or pulling sensation is elicited. In this paper, we applied this phenomenon to the sole (plantar surface of the foot to present the sensation of ground slope. To investigate this, we conducted an experiment that measured the correlation between stimulation temperature and front-back direction position of the center of gravity (COG. Participants stood on a thermal stimulator on Nintendo Wii Balance Board (WBB and they remained standing during 30 s dynamic temperature stimulus. In result of analysis, it was suggested that dynamic thermal change in sole might influence standing position and the effect pattern was anomalous in case of the participants who reported a swaying sensation without a haptic sensation. This behavior might be applied to the diagnosis of the presence of thermoesthesia of the patients who might have disease with absence of thermoesthesia.

  12. Functional Imaging of the Foot with Perfusion Angiography in Critical Limb Ischemia

    Energy Technology Data Exchange (ETDEWEB)

    Reekers, Jim A., E-mail: j.a.reekers@amc.uva.nl [AMC, Dept of Radiology (Netherlands); Koelemay, Mark J. W., E-mail: m.j.koelemaij@amc.uva.nl [AMC, Dept of Vascular Surgery (Netherlands); Marquering, Henk A., E-mail: h.a.marquering@amc.uva.nl; Bavel, Ed T. van, E-mail: e.vanbavel@amc.uva.n [AMC, Dept of Biomedical Engineering and Physics (Netherlands)

    2016-02-15

    PurposeTo report on the first clinical experience with perfusion angiography (PA) of the foot in patients with chronic critical limb ischemia.Materials and MethodsPA is a post-processing software algorithm and no extra digital subtraction angiography (DSA) has to be performed for this analysis. The data used to test the feasibility of PA were obtained from a consecutive group of 89 patients with CLI who were treated with standard below the knee angioplasty and 12 separate patients who were not suitable for endovascular revascularization.ResultsMotion artifacts in the dataset of the DSA made post-procedural analysis impossible in 10 % intervention. In the majority of patients (59/68) PA showed an increase in volume flow in the foot after successful angioplasty of the crural vessels. However, in 9/68 patients no increase was seen after successful angioplasty. With the use of a local administered competitive α-adrenergic receptor antagonist, it is also possible to test and quantify the capillary resistance index which is a parameter for the remaining functionality of the microcirculation in CLI patients.ConclusionPA might be used as a new endpoint for lower limb revascularization and can also be used to test the functionality the microcirculation to identify sub-types of patients with CLI. Clinical evaluation and standardization of PA is mandatory before introduction in daily practice.

  13. Efficacy of custom foot orthotics in improving pain and functional status in children with juvenile idiopathic arthritis: a randomized trial.

    Science.gov (United States)

    Powell, Mary; Seid, Michael; Szer, Ilona S

    2005-05-01

    . To compare the clinical efficacy of custom foot orthotics, prefabricated "off-the-shelf" shoe inserts, and supportive athletic shoes worn alone, on reducing pain and improving function for children with juvenile idiopathic arthritis (JIA). Children with JIA and foot pain (n = 40) were randomized to one of 3 groups receiving: (1) custom-made semirigid foot orthotics with shock absorbing posts (n = 15), (2) off-the-shelf flat neoprene shoe inserts (n = 12), or (3) supportive athletic shoes with a medial longitudinal arch support and shock absorbing soles worn alone (n = 13). Foot pain and functional limitations were measured using the Pediatric Pain Questionnaire-visual analog scale (VAS), Timed Walking, Foot Function Index (FFI), and the Physical Functioning Subscale of the Pediatric Quality of Life Inventory (PedsQL). Measures were administered by personnel blinded to group status at baseline (before wearing the assigned intervention) and at 3 months' followup. Children in the orthotics group showed significantly greater improvements in overall pain (p = 0.009), speed of ambulation (p = 0.013), activity limitations (p = 0.002), foot pain (p = 0.019), and level of disability (p = 0.024) when compared with the other 2 groups. Both children and parents in the orthotics group reported clinically meaningful improvement in child health-related quality of life, although the group by time interaction did not show statistical significance. Except for a reduction in pain for supportive athletic shoes (paired t test, p = 0.011), neither the off-the-shelf shoe inserts nor the supportive athletic shoes worn alone showed significant effect on any of the evaluation measures. In children with JIA, custom-made semirigid foot orthotics with shock-absorbing posts significantly improve pain, speed of ambulation, and self-rated activity and functional ability levels compared with prefabricated off-the-shelf shoe inserts or supportive athletic shoes worn alone.

  14. Changes in foot function, disease activity, and disability after forefoot resection arthroplasty in patients with rheumatoid arthritis.

    Science.gov (United States)

    Sawachika, Fusakazu; Uemura, Hirokazu; Katsuura-Kamano, Sakurako; Yamaguchi, Miwa; Bahari, Tirani; Miki, Keisuke; Todo, Satoshi; Inoo, Masayuki; Onishi, Ikuko; Kurata, Noriyuki; Arisawa, Kokichi

    2016-01-01

    The purpose of this study was to investigate the changes in foot function, disease activity, and disability in patients with RA after resection arthroplasty of the forefoot (arthroplasty). Arthroplasty was performed on 11 patients with RA. All study patients underwent clinical assessment to measure disease activity (Disease Activity Score in 28 Joints-C-reactive protein, DAS28-CRP), disability (Health Assessment Questionnaire-Disability Index, HAQ-DI) and foot function (Foot Function Index, FFI) at the following stages: preoperatively and 1, 3, and 12 months after surgery. Following arthroplasty, foot function improved significantly, as assessed by FFI total and subscales (pain, disability, and limitation of activity) (P<0.001, P<0.001, P<0.001, and P=0.002, respectively). Disease activity was significantly improved in relation to DAS28-CRP and its subscales of number of swollen joints and patient global assessment (PtGA) (P=0.033, P=0.008, and P=0.038, respectively). There was no significant difference in disability, as assessed by the HAQ-DI and its subscale, HAQ-walking (P=0.150 and P=0.597, respectively). Foot function improved significantly after arthroplasty, and was maintained at 12 months postoperatively. Additionally, our study showed that disease activity and its subscale PtGA improved after arthroplasty.

  15. Flat feet, happy feet? Comparison of the dynamic plantar pressure distribution and static medial foot geometry between Malawian and Dutch adults.

    Directory of Open Access Journals (Sweden)

    Niki M Stolwijk

    Full Text Available In contrast to western countries, foot complaints are rare in Africa. This is remarkable, as many African adults walk many hours each day, often barefoot or with worn-out shoes. The reason why Africans can withstand such loading without developing foot complaints might be related to the way the foot is loaded. Therefore, static foot geometry and dynamic plantar pressure distribution of 77 adults from Malawi were compared to 77 adults from the Netherlands. None of the subjects had a history of foot complaints. The plantar pressure pattern as well as the Arch Index (AI and the trajectory of the center of pressure during the stance phase were calculated and compared between both groups. Standardized pictures were taken from the feet to assess the height of the Medial Longitudinal Arch (MLA. We found that Malawian adults: (1 loaded the midfoot for a longer and the forefoot for a shorter period during roll off, (2 had significantly lower plantar pressures under the heel and a part of the forefoot, and (3 had a larger AI and a lower MLA compared to the Dutch. These findings demonstrate that differences in static foot geometry, foot loading, and roll off technique exist between the two groups. The advantage of the foot loading pattern as shown by the Malawian group is that the plantar pressure is distributed more equally over the foot. This might prevent foot complaints.

  16. Flat feet, happy feet? Comparison of the dynamic plantar pressure distribution and static medial foot geometry between Malawian and Dutch adults.

    Science.gov (United States)

    Stolwijk, Niki M; Duysens, Jacques; Louwerens, Jan Willem K; van de Ven, Yvonne Hm; Keijsers, Noël Lw

    2013-01-01

    In contrast to western countries, foot complaints are rare in Africa. This is remarkable, as many African adults walk many hours each day, often barefoot or with worn-out shoes. The reason why Africans can withstand such loading without developing foot complaints might be related to the way the foot is loaded. Therefore, static foot geometry and dynamic plantar pressure distribution of 77 adults from Malawi were compared to 77 adults from the Netherlands. None of the subjects had a history of foot complaints. The plantar pressure pattern as well as the Arch Index (AI) and the trajectory of the center of pressure during the stance phase were calculated and compared between both groups. Standardized pictures were taken from the feet to assess the height of the Medial Longitudinal Arch (MLA). We found that Malawian adults: (1) loaded the midfoot for a longer and the forefoot for a shorter period during roll off, (2) had significantly lower plantar pressures under the heel and a part of the forefoot, and (3) had a larger AI and a lower MLA compared to the Dutch. These findings demonstrate that differences in static foot geometry, foot loading, and roll off technique exist between the two groups. The advantage of the foot loading pattern as shown by the Malawian group is that the plantar pressure is distributed more equally over the foot. This might prevent foot complaints.

  17. Development of a Wearable Sensor System for Dynamically Mapping the Behavior of an Energy Storing and Returning Prosthetic Foot

    Science.gov (United States)

    Hawkins, James; Noroozi, Siamak; Dupac, Mihai; Sewell, Philip

    2016-06-01

    It has been recognized that that the design and prescription of Energy Storing and Returning prosthetic running feet are not well understood and that further information on their performance would be beneficial to increase this understanding. Dynamic analysis of an amputee wearing a prosthetic foot is typically performed using reflective markers and motion-capture systems. High-speed cameras and force plates are used to collect data of a few strides. This requires specialized and expensive equipment in an unrepresentative environment within a large area. Inertial Measurement Units are also capable of being used as wearable sensors but suffer from drift issues. This paper presents the development of a wearable sensing system that records the action of an Energy Storing and Returning prosthetic running foot (sagittal plane displacement and ground contact position) which could have research and/or clinical applications. This is achieved using five standalone pieces of apparatus including foot-mounted pressure sensors and a rotary vario-resistive displacement transducer. It is demonstrated, through the collection of profiles for both foot deflection and ground contact point over the duration of a stride, that the system can be attached to an amputee's prosthesis and used in a non-laboratory environment. It was found from the system that the prosthetic ground contact point, for the amputee tested, progresses along the effective metatarsal portion of the prosthetic foot towards the distal end of the prosthesis over the duration of the stride. Further investigation of the effective stiffness changes of the foot due to the progression of the contact point is warranted.

  18. Development of a Wearable Sensor System for Dynamically Mapping the Behavior of an Energy Storing and Returning Prosthetic Foot

    Directory of Open Access Journals (Sweden)

    Hawkins James

    2016-06-01

    Full Text Available It has been recognized that that the design and prescription of Energy Storing and Returning prosthetic running feet are not well understood and that further information on their performance would be beneficial to increase this understanding. Dynamic analysis of an amputee wearing a prosthetic foot is typically performed using reflective markers and motion-capture systems. High-speed cameras and force plates are used to collect data of a few strides. This requires specialized and expensive equipment in an unrepresentative environment within a large area. Inertial Measurement Units are also capable of being used as wearable sensors but suffer from drift issues. This paper presents the development of a wearable sensing system that records the action of an Energy Storing and Returning prosthetic running foot (sagittal plane displacement and ground contact position which could have research and/or clinical applications. This is achieved using five standalone pieces of apparatus including foot-mounted pressure sensors and a rotary vario-resistive displacement transducer. It is demonstrated, through the collection of profiles for both foot deflection and ground contact point over the duration of a stride, that the system can be attached to an amputee’s prosthesis and used in a non-laboratory environment. It was found from the system that the prosthetic ground contact point, for the amputee tested, progresses along the effective metatarsal portion of the prosthetic foot towards the distal end of the prosthesis over the duration of the stride. Further investigation of the effective stiffness changes of the foot due to the progression of the contact point is warranted.

  19. Shape characteristics of the foot arch: dynamics in the pregnancy period.

    Science.gov (United States)

    Jelen, Karel; Tetkova, Zuzana; Halounova, Lena; Pavelka, Karel; Koudelka, Tomas; Ruzicka, Pavel

    2005-12-01

    The aim is data detection and finding some load consequences generated by various mechanical or physiological changes in the interaction of the end segment of the body--the foot--and the environment. Shape instability of the foot caused by e.g. loading of the foot by long-term frequency loads--walking, by extreme loads--sport, by hormonal changes--pregnancy, by aging, by pathologies, etc. The footprint surface was numerically described in 3D by means of stereo-photo-gram-metrical method--DMR digital relief model. Density of discrete points--250-400 per one print. Detailed DMR was constructed by means of triangular web including contour picture with the use of Atlas program. The specified generated web is characterized by triangles with a cca 1 mm side in the number of up to 4,500 elements per one footprint model. The results enable us to deduce shape characteristics of DMR--the shape of the interactive boundary of the foot--the rest surface, to solve foot arch straining, to solve issues of discomfort and distribution of the pressure at the boundary of the foot--the rest surface, the shoe, etc. The gained findings can be interpreted in the field of prevention, therapy, orthopedics, podology, and enable us to come up with recommendations for the orthopedic practice and industrial use in the footwear production, etc. THE MAIN FINDINGS: The difference between volume reductions of the space under the foot arch characterizes the level of "fall" of the arch. This criterion is independent of the foot size, and is in 3D. Shape characteristics of footprints in pregnant women and in the period after childbirth were calculated on the basis of the defined criterion. The results of the group of four women tested in three periods suggest that there is no clear tendency towards the foot arch falling/increasing of the foot arch "fall" during the pregnancy period.

  20. A functional foot type classification with cluster analysis based on plantar pressure distribution during jogging.

    Science.gov (United States)

    De Cock, A; Willems, T; Witvrouw, E; Vanrenterghem, J; De Clercq, D

    2006-04-01

    The purpose of this study was to establish a reference dataset for peak pressures and pressure-time integrals during jogging, to compare this reference dataset with existing walking data and to develop a foot type classification, all based on plantar pressure data obtained from 215 healthy young adults. The subjects ran at 3.3 m s(-1) over a 16.5 m long running track, with a built-in pressure platform mounted on top of a force platform. Peak pressures, regional impulses and relative regional impulses were measured. These variables were found to be reliable (all intra class correlation coefficients above 0.75) and, except for the heel areas, gender and asymmetry effects could be neglected. Highest peak pressures were found under the heel due to large impact forces during initial contact phase (ICP). In the forefoot, the highest peak pressure was found under the second metatarsal (64.2 +/- 21.1 N cm(-2)). Compared to walking data, overall higher peak pressures and impulses and difference in hallux loading were found during barefoot jogging. Four pressure loading patterns were identified using a K-means cluster analysis, based on the relative regional impulses underneath the forefoot: medial M1 pattern, medial M2 pattern, central pattern and central-lateral pattern. These four pressure loading patterns could help in the functional interpretation of the foot behaviour during the stance phase in slow running.

  1. Model Used for Dynamic Stability Studies in 5 Foot Free-Flight Tunnel

    Science.gov (United States)

    1938-01-01

    Model mounted in the 5-Foot Free-Flight Tunnel. This wind tunnel was used to study the dynamic stability and control characteristics of aircraft in flight. The test section of the tunnel could be tilted to permit the model to fly without restraint when sufficient lift was produced by its wings. During free-flight tests, the tunnel test technique required two engineers. One engineer stood at the side of the test section and controlled the tunnel airspeed and tilt angle while attempting to maintain the airstream relative to the model. The second engineer controlled the airplane model remotely via small wires attached to control surface actuators. The pilot stood behind the tunnel propeller and viewed the rear of the model in flight and assessed its stability and control characteristics for various test conditions. His control box can be seen at the bottom of the picture. The tunnel was authorized in 1936 and was operational in April 1937. Construction cost was $120,000. This exploratory facility was superseded by a larger 12-ft free-flight tunnel in 1939.

  2. Does excessive flatfoot deformity affect function? A comparison between symptomatic and asymptomatic flatfeet using the Oxford Foot Model.

    Science.gov (United States)

    Hösl, Matthias; Böhm, Harald; Multerer, Christel; Döderlein, Leonhard

    2014-01-01

    Treatment of asymptomatic flexible flatfeet is a subject of great controversy. The purpose of this study was to examine foot function during walking in symptomatic (SFF) and asymptomatic (ASFF) flexible flatfeet. Thirty-five paediatric and juvenile patients with idiopathic flexible flatfeet were recruited from an orthopaedic outpatient department (14 SFF and 21 ASFF). Eleven age-matched participants with typically developing feet served as controls (TDF). To study foot function, 3D multi-segment foot kinematics and ankle joint kinetics were captured during barefoot gait analysis. Overall, alterations in foot kinematics in flatfeet were pronounced but differences between SFF and ASFF were not observed. Largest discriminatory effects between flatfeet and TDF were noticed in reduced hindfoot dorsiflexion as well as in increased forefoot supination and abduction. Upon clinical examination, restrictions in passive dorsiflexion in ASFF and SFF were significant. During gait, the hindfoot in flatfeet (both ASFF and SFF) was more everted, but less flexible. In sagittal plane, limited hindfoot dorsiflexion of ASFF and SFF was compensated for by increased forefoot mobility and a hypermobile hallux. Concerning ankle kinetics, SFF lacked positive joint energy for propulsion while ASFF needed to absorb more negative ankle joint energy during loading response. This may risk fatigue and overuse syndrome of anterior shank muscles in ASFF. Hence, despite a lack of symptoms flatfoot deformity in ASFF affected function. Yet, contrary to what was expected, SFF did not show greater deviations in 3D foot kinematics than ASFF. Symptoms may rather depend on tissue wear and subjective pain thresholds.

  3. Functional characteristics of the foot and plantar aponeurosis under tibiotalar loading.

    Science.gov (United States)

    Sarrafian, S K

    1987-08-01

    Structurally the foot is equivalent to a twisted plate. The hindpart is located in the sagittal plane and the forepart in the transverse plane. The transition induced by the twist creates the transverse and the longitudinal arches. Under vertical loading of the foot plate by the tibiotalar column, compressive forces are created on the dorsum and tensile forces on the plantar aspect of the foot plate. The plantar aponeurosis acting as a tie-rod when under tension relieves the tensile forces from the plantar aspect of the foot plate. The increased tension in the plantar aponeurosis in the weightbearing position of the foot occurs with anterior flexion of the leg or with hyperextension of the toes. In the plantigrade position when vertical loading and external rotation are simultaneously applied by the tibiotalar column on the foot, the hindfoot and the midfoot are supinated, and the forefoot is pronated. The medial longitudinal arch is higher, the foot is shorter, and the plantar aponeurosis is relaxed. The foot is then more flexible. With vertical loading and simultaneous internal rotation, the hindfoot and the midfoot are pronated, and the forefoot is supinated. The medial longitudinal arch is lower, the foot is longer, and the plantar aponeurosis is tense. The foot is then more rigid and a better lever arm. Demonstrations are presented both in living and in anatomic dissections.

  4. The impact of rheumatoid arthritis on foot function in the early stages of disease: a clinical case series

    Directory of Open Access Journals (Sweden)

    Emery Paul

    2006-12-01

    Full Text Available Abstract Background Foot involvement occurs early in rheumatoid arthritis but the extent to which this impacts on the structure and function leading to impairment and foot related disability is unknown. The purpose of this study was to compare clinical disease activity, impairment, disability, and foot function in normal and early rheumatoid arthritis (RA feet using standardised clinical measures and 3D gait analysis. Methods Twelve RA patients with disease duration ≤2 years and 12 able-bodied adults matched for age and sex underwent 3D gait analysis to measure foot function. Disease impact was measured using the Leeds Foot impact Scale (LFIS along with standard clinical measures of disease activity, pain and foot deformity. For this small sample, the mean differences between the groups and associated confidence intervals were calculated using the t distribution Results Moderate-to-high foot impairment and related disability were detected amongst the RA patients. In comparison with age- and sex-matched controls, the patients with early RA walked slower (1.05 m/s Vs 1.30 m/s and had a longer double-support phase (19.3% Vs 15.8%. In terminal stance, the heel rise angle was reduced in the patients in comparison with normal (-78.9° Vs -85.7°. Medial arch height was lower and peak eversion in stance greater in the RA patients. The peak ankle plantarflexion power profile was lower in the patients in comparison with the controls (3.4 W/kg Vs 4.6 W/kg. Pressure analysis indicated that the RA patients had a reduced lesser toe contact area (7.6 cm2 Vs 8.1 cm2, elevated peak forefoot pressure (672 kPa Vs 553 kPa and a larger mid-foot contact area (24.6 cm2 Vs 19.4 cm2. Conclusion Analysis detected small but clinically important changes in foot function in a small cohort of RA patients with disease duration

  5. Strength training for the intrinsic flexor muscles of the foot: effects on muscle strength, the foot arch, and dynamic parameters before and after the training.

    Science.gov (United States)

    Hashimoto, Takayuki; Sakuraba, Keishoku

    2014-03-01

    [Purpose] The purpose of the present study was to verify the effects of intrinsic foot flexor strength training. [Subjects] The subjects were 12 healthy males without motor system disease. [Methods] A training method that involved flexion of all toe interphalangeal and metatarsophalangeal joints against a 3-kg load was implemented and was performed for 200 repetitions once per day, three times per week, for a period of eight weeks. [Results] Significant changes were observed for intrinsic foot flexor strength scores, foot arches, vertical jumping, 1-legged long jumping, and 50-m dash time. [Conclusion] This muscle strength training method significantly improved muscle strength scores, foot arch shape, and movement performance.

  6. Evolutionary dynamics of foot-and-mouth disease virus O/ME-SA/Ind2001 lineage.

    Science.gov (United States)

    Subramaniam, Saravanan; Mohapatra, Jajati K; Sharma, Gaurav K; Biswal, Jitendra K; Ranjan, Rajeev; Rout, Manoranjan; Das, Biswajit; Dash, Bana B; Sanyal, Aniket; Pattnaik, Bramhadev

    2015-08-05

    Foot-and-mouth disease (FMD) virus serotype O Ind2001 lineage within the Middle East-South Asia topotype is the major cause of recent FMD incidences in India. A sub-lineage of Ind2001 caused severe outbreaks in the southern region of the country during 2013 and also reported for the first time from Libya. In this study, we conducted a detailed evolutionary analysis of Ind2001 lineage. Phylogenetic analysis of Ind2001 lineage based on maximum likelihood method revealed two major splits and three sub-lineages. The mean nucleotide substitution rate for this lineage was calculated to be 6.338×10(-3)substitutions/site/year (s/s/y), which is similar to those of PanAsian sub-lineages. Evolutionary time scale analysis indicated that the Ind2001 lineage might have originated in 1989. The sub-lineage Ind2001d that caused 2013 outbreaks seems to be relatively more divergent genetically from other Ind2001 sub-lineages. Seven codons in the VP1 region of Ind2001 were found to be under positive selection. Four out of 24 recent Ind2001 strains tested in 2D-MNT had antigenic relationship value of <0.3 with the serotype O vaccine strain indicating intra-epidemic antigenic diversity. Amino acid substitutions found in these minor variants with reference to antigenic diversity have been discussed. The dominance of antigenically homologous strains indicates absence of vaccine immunity in the majority of the affected hosts. Taken together, the evolution of Ind2001 lineage deviates from the strict molecular clock and a typical lineage evolutionary dynamics characterized by periodic emergence and re-emergence of Ind2001 and PanAsia lineage have been observed in respect of serotype O.

  7. Effects of a combined strengthening, stretching and functional training program versus usual-care on gait biomechanics and foot function for diabetic neuropathy: a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Sartor Cristina

    2012-03-01

    Full Text Available Abstract Background Polyneuropathy is a complication of diabetes mellitus that has been very challenging for clinicians. It results in high public health costs and has a huge impact on patients' quality of life. Preventive interventions are still the most important approach to avoid plantar ulceration and amputation, which is the most devastating endpoint of the disease. Some therapeutic interventions improve gait quality, confidence, and quality of life; however, there is no evidence yet of an effective physical therapy treatment for recovering musculoskeletal function and foot rollover during gait that could potentially redistribute plantar pressure and reduce the risk of ulcer formation. Methods/Design A randomised, controlled trial, with blind assessment, was designed to study the effect of a physiotherapy intervention on foot rollover during gait, range of motion, muscle strength and function of the foot and ankle, and balance confidence. The main outcome is plantar pressure during foot rollover, and the secondary outcomes are kinetic and kinematic parameters of gait, neuropathy signs and symptoms, foot and ankle range of motion and function, muscle strength, and balance confidence. The intervention is carried out for 12 weeks, twice a week, for 40-60 min each session. The follow-up period is 24 weeks from the baseline condition. Discussion Herein, we present a more comprehensive and specific physiotherapy approach for foot and ankle function, by choosing simple tasks, focusing on recovering range of motion, strength, and functionality of the joints most impaired by diabetic polyneuropathy. In addition, this intervention aims to transfer these peripheral gains to the functional and more complex task of foot rollover during gait, in order to reduce risk of ulceration. If it shows any benefit, this protocol can be used in clinical practice and can be indicated as complementary treatment for this disease. Trial Registration Clinical

  8. Effects of a combined strengthening, stretching and functional training program versus usual-care on gait biomechanics and foot function for diabetic neuropathy: a randomized controlled trial.

    Science.gov (United States)

    Sartor, Cristina Dallemole; Watari, Ricky; Pássaro, Anice Campos; Picon, Andreja Paley; Hasue, Renata Haydée; Sacco, Isabel C N

    2012-03-19

    Polyneuropathy is a complication of diabetes mellitus that has been very challenging for clinicians. It results in high public health costs and has a huge impact on patients' quality of life. Preventive interventions are still the most important approach to avoid plantar ulceration and amputation, which is the most devastating endpoint of the disease. Some therapeutic interventions improve gait quality, confidence, and quality of life; however, there is no evidence yet of an effective physical therapy treatment for recovering musculoskeletal function and foot rollover during gait that could potentially redistribute plantar pressure and reduce the risk of ulcer formation. A randomised, controlled trial, with blind assessment, was designed to study the effect of a physiotherapy intervention on foot rollover during gait, range of motion, muscle strength and function of the foot and ankle, and balance confidence. The main outcome is plantar pressure during foot rollover, and the secondary outcomes are kinetic and kinematic parameters of gait, neuropathy signs and symptoms, foot and ankle range of motion and function, muscle strength, and balance confidence. The intervention is carried out for 12 weeks, twice a week, for 40-60 min each session. The follow-up period is 24 weeks from the baseline condition. Herein, we present a more comprehensive and specific physiotherapy approach for foot and ankle function, by choosing simple tasks, focusing on recovering range of motion, strength, and functionality of the joints most impaired by diabetic polyneuropathy. In addition, this intervention aims to transfer these peripheral gains to the functional and more complex task of foot rollover during gait, in order to reduce risk of ulceration. If it shows any benefit, this protocol can be used in clinical practice and can be indicated as complementary treatment for this disease. ClinicalTrials.gov Identifier: NCT01207284.

  9. Dynamic pedobarography and radiographic evaluation of surgically treated cavovarus foot deformity in children with Charcot-Marie-Tooth disease.

    Science.gov (United States)

    Erickson, Steven; Hosseinzadeh, Pooya; Iwinski, Henry J; Muchow, Ryan C; Talwalkar, Vishwas R; Walker, Janet L; Milbrandt, Todd A

    2015-07-01

    Pedobarography is a common tool for the evaluation of foot deformity. We describe our radiographic and pedobarographic outcomes of surgical treatment of cavovarus foot deformity in children with Charcot-Marie-Tooth disease. Nineteen patients for a total of 30 feet were included. Preoperative and postoperative dynamic pedobarographic measurements were made and analyzed using the five-mask technique. Pedobarographic measures showed statistical significance for increased contact area and decreased peak forces in most mask areas after surgical treatment. Peak pressure and redistribution of varus pressure patterns trended toward improvement. We found pedobarographic studies helpful; however, pedobarographic data are somewhat difficult to interpret and should be used in addition to clinical and radiographic examination.

  10. Spatial model of the gecko foot hair: functional significance of highly specialized non-uniform geometry

    Science.gov (United States)

    Filippov, Alexander E.; Gorb, Stanislav N.

    2015-01-01

    One of the important problems appearing in experimental realizations of artificial adhesives inspired by gecko foot hair is so-called clusterization. If an artificially produced structure is flexible enough to allow efficient contact with natural rough surfaces, after a few attachment–detachment cycles, the fibres of the structure tend to adhere one to another and form clusters. Normally, such clusters are much larger than original fibres and, because they are less flexible, form much worse adhesive contacts especially with the rough surfaces. Main problem here is that the forces responsible for the clusterization are the same intermolecular forces which attract fibres to fractal surface of the substrate. However, arrays of real gecko setae are much less susceptible to this problem. One of the possible reasons for this is that ends of the seta have more sophisticated non-uniformly distributed three-dimensional structure than that of existing artificial systems. In this paper, we simulated three-dimensional spatial geometry of non-uniformly distributed branches of nanofibres of the setal tip numerically, studied its attachment–detachment dynamics and discussed its advantages versus uniformly distributed geometry. PMID:25657843

  11. Metatarsophalangeal joint function during sprinting: a comparison of barefoot and sprint spike shod foot conditions.

    Science.gov (United States)

    Smith, Grace; Lake, Mark; Lees, Adrian

    2014-04-01

    The metatarsophalangeal joint is an important contributor to lower limb energetics during sprint running. This study compared the kinematics, kinetics and energetics of the metatarsophalangeal joint during sprinting barefoot and wearing standardized sprint spikes. The aim of this investigation was to determine whether standard sprinting footwear alters the natural motion and function of the metatarsophalangeal joint exhibited during barefoot sprint running. Eight trained sprinters performed maximal sprints along a runway, four sprints in each condition. Three-dimensional high-speed (1000 Hz) kinematic and kinetic data were collected at the 20 m point. Joint angle, angular velocity, moment, power and energy were calculated for the metatarsophalangeal joint. Sprint spikes significantly increase sprinting velocity (0.3 m/s average increase), yet limit the range of motion about the metatarsophalangeal joint (17.9% average reduction) and reduce peak dorsiflexion velocity (25.5% average reduction), thus exhibiting a controlling affect over the natural behavior of the foot. However, sprint spikes improve metatarsophalangeal joint kinetics by significantly increasing the peak metatarsophalangeal joint moment (15% average increase) and total energy generated during the important push-off phase (0.5 J to 1.4 J). The results demonstrate substantial changes in metatarsophalangeal function and potential improvements in performance-related parameters due to footwear.

  12. Gait phase detection from sciatic nerve recordings in functional electrical stimulation systems for foot drop correction.

    Science.gov (United States)

    Chu, Jun-Uk; Song, Kang-Il; Han, Sungmin; Lee, Soo Hyun; Kang, Ji Yoon; Hwang, Dosik; Suh, Jun-Kyo Francis; Choi, Kuiwon; Youn, Inchan

    2013-05-01

    Cutaneous afferent activities recorded by a nerve cuff electrode have been used to detect the stance phase in a functional electrical stimulation system for foot drop correction. However, the implantation procedure was difficult, as the cuff electrode had to be located on the distal branches of a multi-fascicular nerve to exclude muscle afferent and efferent activities. This paper proposes a new gait phase detection scheme that can be applied to a proximal nerve root that includes cutaneous afferent fibers as well as muscle afferent and efferent fibers. To test the feasibility of this scheme, electroneurogram (ENG) signals were measured from the rat sciatic nerve during treadmill walking at several speeds, and the signal properties of the sciatic nerve were analyzed for a comparison with kinematic data from the ankle joint. On the basis of these experiments, a wavelet packet transform was tested to define a feature vector from the sciatic ENG signals according to the gait phases. We also propose a Gaussian mixture model (GMM) classifier and investigate whether it could be used successfully to discriminate feature vectors into the stance and swing phases. In spite of no significant differences in the rectified bin-integrated values between the stance and swing phases, the sciatic ENG signals could be reliably classified using the proposed wavelet packet transform and GMM classification methods.

  13. EMG analysis of peroneal and tibialis anterior muscle activity prior to foot contact during functional activities.

    Science.gov (United States)

    McLoda, T A; Hansen, A J; Birrer, D A

    2004-06-01

    The purpose of this investigation was to determine the pre-activity of the tibialis anterior (TA), peroneus longus (PL), and peroneus brevis (PB) prior to foot contact during three conditions. Twenty-six subjects (age 22 +/- 2 yrs; 15 male, 11 female) with no lower extremity injuries reported for data collection. Data were collected from each subject's dominant leg using surface electromyography (EMG). EMG electrodes were applied over the test muscles using a standard protocol. A heel-toe strike transducer was affixed to the bottom of the subject's shoe. The subject completed two randomized trials of walking on a treadmill (5.6 kph), jogging on a treadmill (9.3 kph) and drop landing from a 38 cm box. Isometric reference positions (IRPs) were recorded for the TA, PL, and PB. Muscle data were normalized to IRPs and the average processed EMG for the 200 ms prior to heel strike during walking and jogging and prior to toe strike when dropping from the box was used for analysis. A one-way repeated measures MANOVA was used to detect differences in pre-activity of the muscles between the three conditions. Univariate tests were used to determine differences for each muscle and Tukey's was applied post hoc to determine individual effect differences. The MANOVA revealed significant differences among the three conditions (F2.50 = 10.770; P < .0005). Average TA activity was significantly higher during jogging (Tukey's; P < .0005). Significant differences existed between each condition for the TA. Average PL and PB activity was significantly higher when drop landing (Tukey's; P < .0005). There was no significant difference between walking and jogging for the PL and PB. The amount of muscle pre-activity occurring before heel or toe strike provides useful information for the examination of reaction times to unexpected inversion during dynamic activities.

  14. The effect of different shoes on functional mobility and energy expenditure in post-stroke hemiplegic patients using ankle-foot orthosis.

    Science.gov (United States)

    Farmani, Farzad; Mohseni Bandpei, Mohammad Ali; Bahramizadeh, Mahmood; Aminian, Gholamreza; Nikoo, Mohammad Reza; Sadeghi-Goghari, Mohammad

    2016-10-01

    Ankle-foot orthoses could be utilized both with and without shoes. While several studies have shown that ankle-foot orthoses improve gait abilities in hemiplegic patients, it remains unclear whether they should be used with shoes or without. The study purpose was to compare the effect of standard shoes and rocker shoes on functional mobility in post-stroke hemiplegic patients utilizing ankle-foot orthosis. Randomized clinical study. Thirty post-stroke hemiplegic patients participated in this study randomly assigned to two groups. Group I received standard shoes + ankle-foot orthosis and group II were provided with rocker shoes + ankle-foot orthosis. Their functional mobility and energy expenditure parameters including timed up and go, timed up stairs, timed down stairs, preferred walking speed, and oxygen (O2) cost (mL/kg/m) were measured. In group I, no significant changes were seen in outcome measures after wearing standard shoes. While in group II, O2 cost and timed up and go time significantly decreased, and preferred walking speed increased when patients wore rocker shoes. Also, there was a significant difference between rocker shoes and standard shoes in improvement of timed up and go, preferred walking speed, and O2 cost. When patients using ankle-foot orthosis wore rocker shoes, their functional mobility improved and oxygen cost diminished. Also, rocker shoes was significantly more effective than standard shoes in improving functional mobility parameters. This study suggests that in post-stroke hemiplegic patients using ankle-foot orthosis, wearing rocker shoes can lead to much more improved functional mobility and decreased energy expenditure compared to ankle-foot orthosis only. Thus, in stroke patients, the combination of ankle-foot orthosis-rocker shoes is recommended for both rehabilitation programs and ankle-foot orthosis efficacy investigations. © The International Society for Prosthetics and Orthotics 2015.

  15. The effects of plantar flexor static stretching and dynamic stretching using an aero-step on foot pressure during gait in healthy adults: a preliminary study.

    Science.gov (United States)

    Shim, Je-Myung; Jung, Ju-Hyeon; Kim, Hwan-Hee

    2015-07-01

    [Purpose] The aim of this study was to examine whether plantar flexor static stretching and dynamic stretching using an Aero-Step results in changes in foot pressure during gait in healthy adults. [Subjects] Eighteen normal adults were randomly allocated to either a dynamic stretching using an Aero-Step group (DSUAS) group (n = 8) or a static stretching (SS) group (n = 10). [Methods] The DSUAS and SS participants took part in an exercise program for 15 minutes. Outcome measures were foot plantar pressure, which was measured during the subject's gait stance phase; the asymmetric ratio of foot pressure for both feet; and the visual analogue scale (VAS) measured during the interventions. [Results] There were significant differences in the asymmetric ratio of foot pressure for both feet and VAS between the two groups after intervention. However, there were no significant differences in foot plantar pressure during the gait stance phase within both groups. [Conclusion] DSUSAS is an effective stretching method, as pain during it is lower than that with SS, which can minimize the asymmetric ratio of foot pressure for both feet during gait due to asymmetric postural alignment.

  16. Multi-functional foot use during running in the zebra-tailed lizard (Callisaurus draconoides).

    Science.gov (United States)

    Li, Chen; Hsieh, S Tonia; Goldman, Daniel I

    2012-09-15

    A diversity of animals that run on solid, level, flat, non-slip surfaces appear to bounce on their legs; elastic elements in the limbs can store and return energy during each step. The mechanics and energetics of running in natural terrain, particularly on surfaces that can yield and flow under stress, is less understood. The zebra-tailed lizard (Callisaurus draconoides), a small desert generalist with a large, elongate, tendinous hind foot, runs rapidly across a variety of natural substrates. We use high-speed video to obtain detailed three-dimensional running kinematics on solid and granular surfaces to reveal how leg, foot and substrate mechanics contribute to its high locomotor performance. Running at ~10 body lengths s(-1) (~1 m s(-1)), the center of mass oscillates like a spring-mass system on both substrates, with only 15% reduction in stride length on the granular surface. On the solid surface, a strut-spring model of the hind limb reveals that the hind foot saves ~40% of the mechanical work needed per step, significant for the lizard's small size. On the granular surface, a penetration force model and hypothesized subsurface foot rotation indicates that the hind foot paddles through fluidized granular medium, and that the energy lost per step during irreversible deformation of the substrate does not differ from the reduction in the mechanical energy of the center of mass. The upper hind leg muscles must perform three times as much mechanical work on the granular surface as on the solid surface to compensate for the greater energy lost within the foot and to the substrate.

  17. Role of dynamic MRI in the follow-up of acute Charcot foot in patients with diabetes mellitus

    Energy Technology Data Exchange (ETDEWEB)

    Zampa, Virna; Bargellini, Irene; Turini, Francesca; Ortori, Simona; Bartolozzi, Carlo [University of Pisa, Department of Diagnostic and Interventional Radiology, Pisa (Italy); Rizzo, Loredana; Piaggesi, Alberto [University of Pisa, Department of Endocrinology and Metabolism, Diabetic Foot Section, Pisa (Italy)

    2011-08-15

    To evaluate the usefulness of magnetic resonance imaging (MRI) in assessing the level of activity of acute Charcot foot, monitoring treatment response and predicting healing time. Forty diabetic patients with acute Charcot foot were prospectively enrolled. Patients underwent limb immobilization and were followed every 3 months by clinical examination (skin temperature and circumferences) and MRI. MR protocol included T1-weighted and fast spin echo inversion recovery (FSE-IR) sequences, and a dynamic study (fast spoiled gradient echo), after gadolinium administration (0.1 ml/kg). The contrast medium uptake rate at D-MRI and the signal intensity (SI) ratio on the FSE-IR sequence were measured. At baseline, mean contrast medium uptake rate was 136{+-}49.7% and the mean SI ratio was 5{+-}3. A high intra- and inter-observer agreement was found for the contrast medium uptake rate, whereas a low agreement was observed for the SI ratio. At 3 months' follow-up, reduction of the contrast medium uptake rate was observed in all patients with improved clinical findings (n = 34), whereas the SI ratio was reduced in 15/34 (44.1%) patients. Mean healing time was significantly related to the baseline contrast medium uptake rate (P=0.005); it was 5.3 {+-} 2.7 months in patients with contrast medium uptake rate {<=}100%, compared with 9.1 {+-} 2.5 months in the remaining patients (P=0.0003). Contrast medium uptake rate obtained at D-MRI represents a reproducible parameter that is reliable for predicting and monitoring treatment outcome in acute Charcot foot. (orig.)

  18. The effect of foot plantar massage on balance and functional reach in patients with type II diabetes.

    Science.gov (United States)

    Tütün Yümin, Eylem; Şimşek, Tülay Tarsuslu; Sertel, Meral; Ankaralı, Handan; Yumin, Murat

    2017-02-01

    The aim of this study was to investigate the effect of manual foot plantar massage (classic and friction massage) on functional mobility level, balance, and functional reach in patients with type II diabetes mellitus (T2 DM). A total of 38 subjects diagnosed with T2 DM were included in the study. A healthy control group could not be formed in this study. After the subjects' socio-demographic data were obtained, Timed Up & Go (TUG) Test, functional reach test (FRT), one-leg standing test with eyes open-closed, and Visual Analogue Scale (VAS) to measure foot pain intensity were performed. The results were also divided and assessed in three groups according to the ages of the individuals (40-54, 55-64, and 65 and over). As a result of statistical analysis, a difference was found in the values obtained from TUG, FRT, and one-leg standing test with eyes open and closed (p massage, TUG values significantly decreased comparison with those before the massage, whereas the values of FRT and one-leg standing test with eyes open and closed significantly increased compared with those before the massage (p > 0.05). According to age groups, there were statistical differences (p massage. The results of our study indicated that application of plantar massage to patients with T2 DM caused an improvement in balance, functional mobility, and functional reach values. An increase in body balance and functional mobility may explain the improvement in TUG. Foot massage to be added to rehabilitation exercise programs of DM patients will be important in improving balance and mobility of patients.

  19. Gender-related Changes in Dorsal Hand and Foot Vein Function Following 60 Days of Head Down Bed Rest

    Science.gov (United States)

    Westby, Christian M.; Phillips, Tiffany; Stenger, Michael B.; Platts, Steven H.

    2009-01-01

    It is well known that female astronauts are more likely to experience post-flight orthostatic hypotension and presyncope compared to male astronauts. It has been suggested that the disproportionally higher incidence of presyncope (83% of female vs. 20% male crewmembers) may be due to sex-related differences in vascular function between the upper and lower limbs. However, much of this evidence is specific to changes in resistance vessels. Given that more than 70% of the circulating blood volume resides in compliance vessels, it is conceivable that even small changes in venous function may contribute to post-flight orthostatic hypotension. In spite of this, little is currently known regarding the influence of microgravity exposure on venous function between males and females. PURPOSE: To determine the influence of 60 days of HDBR on dorsal foot and hand vein function between healthy males (M) and females (F). METHODS: Using 2-D ultrasound, dorsal hand and foot vein diameter responses to intravenous infusions phenylephrine (PE), acetylcholine (ACh), and nitroglycerine (NTG) were determined in 26 adults; 10 females (age:37 +/- 2 yr ) and 16 males (age:34 +/- 2 yr ). Changes in venous function were calculated as the difference between diameter at baseline and following each venoactive drug. Differences in venous function between limb and sexes across HDBR were determined using mixed-effects linear regression. RESULTS: In response to 60 days of HDBR, the change in venousconstrictor response to PE in the dorsal hand veins was not significantly different between M and F. Interestingly, the change in constrictor response in the dorsal foot veins (compared to pre HDBR) was approximately 30% greater in the F, whereas the constrictor response was approximately 45% less in the M (p=0.026). HDBR had no influence on the change in dilator response to ACh, or NTG between M and F and between vascular beds. CONCLUSION: These results demonstrate that 60 days of HDBR contributes to sex

  20. Foot Health

    Science.gov (United States)

    ... straight across and not too short Your foot health can be a clue to your overall health. For example, joint stiffness could mean arthritis. Tingling ... foot checks are an important part of your health care. If you have foot problems, be sure ...

  1. Selective laser sintered versus carbon fiber passive-dynamic ankle-foot orthoses: a comparison of patient walking performance.

    Science.gov (United States)

    Harper, Nicole G; Russell, Elizabeth M; Wilken, Jason M; Neptune, Richard R

    2014-09-01

    Selective laser sintering (SLS) is a well-suited additive manufacturing technique for generating subject-specific passive-dynamic ankle-foot orthoses (PD-AFOs). However, the mechanical properties of SLS PD-AFOs may differ from those of commonly prescribed carbon fiber (CF) PD-AFOs. Therefore, the goal of this study was to determine if biomechanical measures during gait differ between CF and stiffness-matched SLS PD-AFOs. Subject-specific SLS PD-AFOs were manufactured for ten subjects with unilateral lower-limb impairments. Minimal differences in gait performance occurred when subjects used the SLS versus CF PD-AFOs. These results support the use of SLS PD-AFOs to study the effects of altering design characteristics on gait performance.

  2. Functional β2-adrenoceptors in rat left atria: effect of foot-shock stress.

    Science.gov (United States)

    Moura, André Luiz de; Hyslop, Stephen; Grassi-Kassisse, Dora M; Spadari, Regina C

    2017-09-01

    Altered sensitivity to the chronotropic effect of catecholamines and a reduction in the β1/β2-adrenoceptor ratio have previously been reported in right atria of stressed rats, human failing heart, and aging. In this report, we investigated whether left atrial inotropism was affected by foot-shock stress. Male rats were submitted to 3 foot-shock sessions and the left atrial inotropic response, adenylyl cyclase activity, and β-adrenoceptor expression were investigated. Left atria of stressed rats were supersensitive to isoprenaline when compared with control rats and this effect was abolished by ICI118,551, a selective β2-receptor antagonist. Schild plot slopes for the antagonism between CGP20712A (a selective β1-receptor antagonist) and isoprenaline differed from unity in atria of stressed but not control rats. Atrial sensitivity to norepinephrine, as well as basal and forskolin- or isoprenaline-stimulated adenylyl cyclase activities were not altered by stress. The effect of isoprenaline on adenylyl cyclase stimulation was partially blocked by ICI118,551 in atrial membranes of stressed rats. These findings indicate that foot-shock stress equally affects inotropism and chronotropism and that β2-adrenoceptor upregulation contributes to the enhanced inotropic response to isoprenaline.

  3. Multi-functional foot use during running in the zebra-tailed lizard (Callisaurus draconoides)

    CERN Document Server

    Li, Chen; Goldman, Daniel I; 10.1242/jeb.061937

    2013-01-01

    A diversity of animals that run on solid, level, flat, non-slip surfaces appear to bounce on their legs; elastic elements in the limbs can store and return energy during each step. The mechanics and energetics of running in natural terrain, particularly on surfaces that can yield and flow under stress, is less understood. The zebra-tailed lizard (Callisaurus draconoides), a small desert generalist with a large, elongate, tendinous hind foot, runs rapidly across a variety of natural substrates. We use high speed video to obtain detailed three-dimensional running kinematics on solid and granular surfaces to reveal how leg, foot, and substrate mechanics contribute to its high locomotor performance. Running at ~10 body length/s (~1 m/s), the center of mass oscillates like a spring-mass system on both substrates, with only 15% reduction in stride length on the granular surface. On the solid surface, a strut-spring model of the hind limb reveals that the hind foot saves about 40% of the mechanical work needed per s...

  4. DNA functionalization by dynamic chemistry

    Directory of Open Access Journals (Sweden)

    Zeynep Kanlidere

    2016-10-01

    Full Text Available Dynamic combinatorial chemistry (DCC is an attractive method to efficiently generate libraries of molecules from simpler building blocks by reversible reactions under thermodynamic control. Here we focus on the chemical modification of DNA oligonucleotides with acyclic diol linkers and demonstrate their potential for the deoxyribonucleic acid functionalization and generation of libraries of reversibly interconverting building blocks. The syntheses of phosphoramidite building blocks derived from D-threoninol are presented in two variants with protected amino or thiol groups. The threoninol building blocks were successfully incorporated via automated solid-phase synthesis into 13mer oligonucleotides. The amino group containing phosphoramidite was used together with complementary single-strand DNA templates that influenced the Watson–Crick base-pairing equilibrium in the mixture with a set of aldehyde modified nucleobases. A significant fraction of all possible base-pair mismatches was obtained, whereas, the highest selectivity (over 80% was found for the guanine aldehyde templated by the complementary cytosine containing DNA. The elevated occurrence of mismatches can be explained by increased backbone plasticity derived from the linear threoninol building block as a cyclic deoxyribose analogue.

  5. The foot structure from the type 1 ryanodine receptor is required for functional coupling to store-operated channels.

    Science.gov (United States)

    Sampieri, Alicia; Diaz-Muñoz, Mauricio; Antaramian, Anaid; Vaca, Luis

    2005-07-01

    In the present study we have explored structural determinants of the functional interaction between skeletal muscle ryanodine receptor (RyR1) and transient receptor potential channel 1 (TRPC1) channels expressed in Chinese hamster ovary cells. We have illustrated a functional interaction between TRPC1 channels and RyR1 for the regulation of store-operated calcium entry (SOCE) initiated after releasing calcium from a caffeine-sensitive intracellular calcium pool. RNA interference experiments directed to reduce the amount of TRPC1 protein indicate that RyR1 associates to at least two different types of store-operated channels (SOCs), one dependent and one independent of TRPC1. In contrast, bradykinin-induced SOCE is completely dependent on the presence of TRPC1 protein, as we have previously illustrated. Removing the foot structure from RyR1 results in normal caffeine-induced release of calcium from internal stores but abolishes the activation of SOCE, indicating that this structure is require for functional coupling to SOCs. The footless RyR1 protein shows a different cellular localization when compared with wild type RyR1. The later protein shows a higher percentage of colocalization with FM-464, a marker of plasma membrane. The implications of the foot structure for the functional and physical coupling to TRPC and SOCs is discussed.

  6. Molecular Dynamics and Protein Function

    National Research Council Canada - National Science Library

    M. Karplus; J. Kuriyan; Bruce J. Berne

    2005-01-01

    .... Molecular dynamics simulations provide powerful tools for the exploration of the conformational energy landscape accessible to these molecules, and the rapid increase in computational power coupled...

  7. Role of ankle foot orthosis in improving locomotion and functional recovery in patients with stroke: A prospective rehabilitation study

    Directory of Open Access Journals (Sweden)

    H Sankaranarayan

    2016-01-01

    Full Text Available Objective: To study role of ankle foot orthosis (AFO in improving locomotion and functional recovery after stroke. Setting: Neurological Rehabilitation Department of a university research tertiary hospital. Patients and Methods: AFO and activity based rehabilitation. Main Outcome Measures: Distance (meters covered during the 6-minute walk test (6MWT and speed (meter/second during the 10-meter walk test. Functional abilities assessed using Functional Independence Measure (FIM®. Results: Twenty-six patients (21 male with stroke (mean duration 196.7 days, range 45–360 days and mean age of 41.6 years (range 18–65 years, standard deviation [SD] 12.5 were included. Fourteen had right hemiplegia. The mean length of stay in the unit was 26.5 days (range 18–45 days, SD 5.5. All patients had equinus deformity with spastic foot drop and were provided with AFO. Walking endurance with 6MWT was 90 m on admission (without AFO. At discharge, it improved to 174 m with AFO and 121 m without AFOs (P 0.16 m/s speed gain; >50 m endurance gain at discharge. The mean FIM® score on admission was 84.3 ± 18.6. At discharge FIM® improved to 101.9 ± 13.7 (P < 0.001. Conclusions: Use of AFOs improve gait parameters significantly in only one-third stroke patients in the study when combined with activity-based inpatient-rehabilitation.

  8. Role of ankle foot orthosis in improving locomotion and functional recovery in patients with stroke: A prospective rehabilitation study

    Science.gov (United States)

    Sankaranarayan, H.; Gupta, Anupam; Khanna, Meeka; Taly, Arun B.; Thennarasu, K.

    2016-01-01

    Objective: To study role of ankle foot orthosis (AFO) in improving locomotion and functional recovery after stroke. Setting: Neurological Rehabilitation Department of a university research tertiary hospital. Patients and Methods: AFO and activity based rehabilitation. Main Outcome Measures: Distance (meters) covered during the 6-minute walk test (6MWT) and speed (meter/second) during the 10-meter walk test. Functional abilities assessed using Functional Independence Measure (FIM®). Results: Twenty-six patients (21 male) with stroke (mean duration 196.7 days, range 45–360 days) and mean age of 41.6 years (range 18–65 years, standard deviation [SD] 12.5) were included. Fourteen had right hemiplegia. The mean length of stay in the unit was 26.5 days (range 18–45 days, SD 5.5). All patients had equinus deformity with spastic foot drop and were provided with AFO. Walking endurance with 6MWT was 90 m on admission (without AFO). At discharge, it improved to 174 m with AFO and 121 m without AFOs (P 0.16 m/s speed gain; >50 m endurance gain) at discharge. The mean FIM® score on admission was 84.3 ± 18.6. At discharge FIM® improved to 101.9 ± 13.7 (P < 0.001). Conclusions: Use of AFOs improve gait parameters significantly in only one-third stroke patients in the study when combined with activity-based inpatient-rehabilitation. PMID:27695234

  9. The effects of backpack loads and spinal stabilization exercises on the dynamic foot pressure of elementary school children with idiopathic scoliosis.

    Science.gov (United States)

    Lee, Suemin; Shim, Jemyung

    2015-07-01

    [Purpose] The purpose of this study was to measure and observe the changes in dynamic plantar pressures when school children carried specific bag loads, and to determine whether improved physical balance after an eight-week spinal stabilization exercise program can influences plantar pressures. [Subjects] The subjects were 10 school students with Cobb angles of 10° or greater. [Methods] Gait View Pro 1.0 (Alfoots, Korea) was were based on to measure the pressure of the participants' feet. Spinal stabilization exercises used TOGU Multi-roll Functional (TOGU, Germany) training. Dynamic plantar pressures were measured with bag loads of 0% no bag and 15% of subjects' body weight. The independent t test was performed to analyze changes in plantar pressures. [Results] The plantar pressure measurements of bag load of 0% of subjects' body weight before and after the spinal stabilization exercise program were not significantly different, but those of two foot areas with a 15% load were statistically significant (mt5, 67.32±24.25 and 51.77±25.52 kPa; lat heel, 126.00±20.46 and 102.08±23.87 kPa). [Conclusion] After performance of the spinal stabilization exercises subjects' overall plantar pressures were reduced, which may suggest that physical balance improved.

  10. Analysis of Foot Slippage Effects on an Actuated Spring-mass Model of Dynamic Legged Locomotion

    National Research Council Canada - National Science Library

    Yizhar Or; Moti Moravia

    2016-01-01

      The classical model of spring-loaded inverted pendulum (SLIP) and its extensions have been widely accepted as a simple description of dynamic legged locomotion at various scales in humans, legged robots and animals...

  11. Wide-pulse electrical stimulation to an intrinsic foot muscle induces acute functional changes in forefoot-rearfoot coupling behaviour during walking.

    Science.gov (United States)

    James, D C; Chesters, T; Sumners, D P; Cook, D P; Green, D A; Mileva, K N

    2013-05-01

    Interventions for strengthening intrinsic foot muscles may be beneficial for rehabilitation from overuse injuries. In this study the acute effects of high-frequency, low-intensity wide-pulse electrical stimulation (WPS) over an intrinsic muscle on subsequent foot function during walking was assessed in healthy participants. WPS was delivered to the m. abductor hallucis (m.AH) of the non-dominant foot during relaxed standing. 3-dimensional forefoot (FF)--rearfoot (RF) coordination was quantified with a vector coding technique within separate periods of the stance phase to study WPS functional effects on foot motion. 4 types of coordinative strategies between the FF and RF were interpreted and compared PRE-to-POST-WPS for both the experimental and control feet. Bilateral electromyography (EMG) from m.AH was analysed during the intervention period for evidence of acute neuromuscular adaptation. The results showed that WPS significantly modulated FF-RF coordination during mid-stance, indicative of a more stable foot. Specifically, a statistically significant increase in FF eversion with concomitant RF inversion in the frontal plane and RF-dominated adduction in the transverse plane was observed. Subject-specific increases in post-stimulus m.AH EMG activation were observed but this was not reflected in an overall group effect. It is concluded that the structural integrity of the foot during walking is enhanced following an acute session of WPS and that this mechanical effect is most likely due to stimulation induced post-tetanic potentiation of synaptic transmission.

  12. Age- and Sex-Related Normative Data for the Foot Function Index in a German-Speaking Cohort.

    Science.gov (United States)

    Schneider, Wolfgang; Jurenitsch, Stefan

    2016-11-01

    Despite increasing popularity of the Foot Function Index (FFI), normative values are still unavailable for this self-administered score. This study was designed to generate age- and sex-related normative values for the FFI-total and for both subscales FFI-pain and FFI-disability. We used the cross-cultural adapted and validated German version of the FFI to generate a data pool using the results of 625 individuals, including staff and visitors to our hospital and excluding persons scheduled for foot surgery or in after-treatment. Mean values for FFI-total were calculated: 15.3 points (95% confidence interval [CI], 13.3-16.9), 14.9 points for FFI-pain (CI, 13.3-16.5), and 15.6 for FFI-disability (CI, 13.8-17.4). Results showed higher values for FFI-total, FFI-pain, and FFI-disability for individuals older than 40 years. In general, normative values showed a tendency for higher values with age. A slightly inconsistent distribution over different age groups with a peak for individuals in their 40s and 50s was observed, especially for FFI-pain. Men had better scores than women. Individuals with previous surgery showed lower scores in their respective score. Our data calculated normative values for a German-speaking cohort for FFI-total as well as for both subscales FFI-pain and FFI-disability. Our data quantified the increase of FFI-total, FFI-pain, and FFI-disability normative values with age but also showed a slightly inconsistent distribution of normative values over all age groups. We demonstrated higher normative values for women and slightly higher normative values for individuals with previous foot or ankle surgery. II, prospective comparative study. © The Author(s) 2016.

  13. Real-time feedback of dynamic foot pressure index for gait training of toe-walking children with spastic diplegia.

    Science.gov (United States)

    Pu, Fang; Ren, Weiyan; Fan, Xiaoya; Chen, Wei; Li, Shuyu; Li, Deyu; Wang, Yu; Fan, Yubo

    2017-09-01

    The aim of this study was to determine whether and how real-time feedback of dynamic foot pressure index (DFPI) could be used to correct toe-walking gait in spastic diplegic children with dynamic equinus. Thirteen spastic diplegic children with dynamic equinus were asked to wear a monitoring device to record their ambulation during daily gait, conventional training gait, and feedback training gait. Parameters based on their DFPI and stride duration were compared among the three test conditions. The results with feedback training were significantly better for all DFPI parameters in comparison to patients' daily gait and showed significant improvements in DFPI for toe-walking gait and percentage of normal gait in comparison to conventional training methods. Moreover, stride duration under two training gaits was longer than patient's daily gait, but there was no significant difference between the two training gaits. Although the stride duration for the two training gaits was similar, gait training with real-time feedback of DFPI did produce noticeably superior results by increasing heel-loading impulse of toe-walking gait and percentage of normal gait in comparison to convention training methods. However, its effectiveness was still impacted by the motion limitations of diplegic children. Implications for Rehabilitation The DFPI-based gait training feedback system introduced in this study was shown to be more effective at toe-walking gait rehabilitation training over conventional training methods. The feedback system accomplished superior improvement in correcting toe-walking gait, but its effectiveness in an increasing heel-loading impulse in normal gait was still limited by the motion limitations of diplegic children. Stride duration of normal gait and toe-walking gait was similar under conventional and feedback gait training.

  14. Dynamics and computation in functional shifts

    Science.gov (United States)

    Namikawa, Jun; Hashimoto, Takashi

    2004-07-01

    We introduce a new type of shift dynamics as an extended model of symbolic dynamics, and investigate the characteristics of shift spaces from the viewpoints of both dynamics and computation. This shift dynamics is called a functional shift, which is defined by a set of bi-infinite sequences of some functions on a set of symbols. To analyse the complexity of functional shifts, we measure them in terms of topological entropy, and locate their languages in the Chomsky hierarchy. Through this study, we argue that considering functional shifts from the viewpoints of both dynamics and computation gives us opposite results about the complexity of systems. We also describe a new class of shift spaces whose languages are not recursively enumerable.

  15. Elements and modulation of functional dynamics.

    Science.gov (United States)

    Gibbs, Alan C

    2014-10-09

    The existing structure-function paradigm of drug discovery has been evolving toward the essential incorporation of dynamics data. This new functional dynamics paradigm emphasizes conformational entropy as a driving force of protein function and intermolecular recognition. Conformational dynamics (a proxy of conformational entropy) impacts the degree of protein (dis)order and the constitution of the conformational ensemble, the mechanisms of allostery and drug resistance, and the free energy of ligand binding. Specific protein and ligand conformations facilitate favorable, reciprocal interactions. The number of protein and ligand conformers that exhibit favorable binding interactions will vary from system to system. All binding scenarios can modulate protein dynamics by various levels of enthalpic and entropic contribution, with significant influence on the functional dynamics of the system. Analysis and consideration of resulting changes of activity, signaling, catalysis, and subsequent phenotypic outcome are powerful motivations in the drug design process.

  16. A self-adaptive foot-drop corrector using functional electrical stimulation (FES) modulated by tibialis anterior electromyography (EMG) dataset.

    Science.gov (United States)

    Chen, Mo; Wu, Bian; Lou, Xinxin; Zhao, Ting; Li, Jianhua; Xu, Zhisheng; Hu, Xiaoling; Zheng, Xiaoxiang

    2013-02-01

    We developed a functional electrical stimulator for correcting the gait patterns of patients with foot-drop problem. The stimulating electrical pulses of the system are modulated to evoke contractions of the tibialis anterior muscle, by emulating the normal patterns. The modulation is adaptive, i.e. the system can predict the user's step frequency and the generated stimulation can match each step in real-time. In this study, step data from 11 young healthy volunteers were acquired, and five prediction algorithms were evaluated by the acquired data, including the average of Previous N steps (P-N), the Previous Nth step (P-Nth), General Regression Neural Network (GRNN), Autoregressive (AR) and Kalman filter (KF). The algorithm with the best efficiency-accuracy trade-off (P-N, when N=5) was implemented in the FES system. System evaluation results obtained from a post-stroke patient with foot-drop showed that the system of this study demonstrated better performance on gait pattern correction than the methods widely adopted in commercial products.

  17. Computationally Efficient Modelling of Dynamic Soil-Structure Interaction of Offshore Wind Turbines on Gravity Footings

    DEFF Research Database (Denmark)

    Damgaard, Mads; Andersen, Lars Vabbersgaard; Ibsen, Lars Bo

    2014-01-01

    The formulation and quality of a computationally efficient model of offshore wind turbine surface foundations is examined. The aim is to establish a model, workable in the frequency and time domain, that can be applied in aeroelastic codes for fast and reliable evaluation of the dynamic structural...... response of wind turbines, in which the geometrical dissipation related to wave propagation into the subsoil is included. Based on the optimal order of a consistent lumped-parameter model obtained by the domain-transformation method and a weighted least-squares technique, the dynamic vibration response...... to wave propagating in the subsoil–even for soil stratifications with low cut-in frequencies. In this regard, utilising discrete second-order models for the physical interpretation of a rational filter puts special demands on the Newmark β-scheme, where the time integration in most cases only provides...

  18. Dynamic characteristics of power-tower space stations with 15-foot truss bays

    Science.gov (United States)

    Dorsey, J. T.

    1986-01-01

    A power tower space station concept which generates power with photovoltaic arrays and where the truss structure has a bay size of 15 ft is described. Rigid body and flexible body dynamic characteristics are presented for a 75-kW Initial Operating Capability (IOC) and 150-kW and 300-kW growth stations. The transient response of the IOC and 300-kW growth stations to shuttle dock, orbit reboost, and mobile remote manipulator system translation loads are studied. Displacements, accelerations, and bending moments at various locations on the IOC and 300-kW growth stations are presented.

  19. Dynamical Functional Theory for Compressed Sensing

    DEFF Research Database (Denmark)

    Cakmak, Burak; Opper, Manfred; Winther, Ole

    2017-01-01

    the Thouless Anderson-Palmer (TAP) equations corresponding to the ensemble. Using a dynamical functional approach we are able to derive an effective stochastic process for the marginal statistics of a single component of the dynamics. This allows us to design memory terms in the algorithm in such a way...

  20. Spatiotemporal Dynamics of Hand-Foot-Mouth Disease and Its Relationship with Meteorological Factors in Jiangsu Province, China.

    Science.gov (United States)

    Liu, Wendong; Ji, Hong; Shan, Jun; Bao, Jin; Sun, Yan; Li, Juan; Bao, Changjun; Tang, Fenyang; Yang, Kun; Bergquist, Robert; Peng, Zhihang; Zhu, Yefei

    2015-01-01

    Hand, foot and mouth disease (HFMD) is an important public health issue in mainland China, including Jiangsu Province. The main purpose of this study was to depict the epidemiological characteristics of HFMD and evaluate the effects of meteorological variables on its dynamics via spatiotemporal analytic methods, which is essential for formulating scientific and effective prevention and control strategies and measures. In total, 497,910 cases of HFMD occurred in the 2009-2013 period, with an average annual incidence of 126.3 per 100,000 in Jiangsu. Out of these, 87.7% were under 5 years old with a male-to-female incidence ratio of 1.4. The dominant pathogens of the laboratory-confirmed cases were EV71 and CoxA16, accounting for 44.8% and 30.6% of all cases, respectively. Two incidence peaks were observed in each year, the higher occurring between April and June, the lower between November and December. The incidence ranged between 16.8 and 233.5 per 100,000 at the county level. The incidence in the South of the province was generally higher than that in the northern regions. The most likely spatiotemporal cluster detected by space-time scan analysis occurred in May-June of 2012 in the southern region. Average temperature and rainfall were positively correlated with HFMD incidence, while the number of days with rainfall ≥ 0.1mm, low temperature, high temperature and hours of sunshine were negatively related. Particularly, relative humidity had no relationship. In conclusion, the prevalence of HFMD in Jiangsu Province has an obvious feature of seasonality. The etiological composition changed dynamically and might be a latent driving force for the temporal variation of the incidence of HFMD. A moderately warm environment promotes the transmission of the HFMD viruses, while particularly cold and hot climate conditions restrain their transmission.

  1. Gait Measures and Dynamic Weight bearing in Young and Elder Trans-tibal Amputee using PTB Prosthesis with SACH foot

    Directory of Open Access Journals (Sweden)

    Prasanna K. Lenka

    2008-12-01

    Full Text Available Objective: to investigate the changes associated with age in gait characteristics and dynamic weight bearing pattern of sound and prosthetic limb of persons with unilateral amputation. Participant: two groups of seven young (24±3.8 years and seven elderly unilateral amputee (71±6 years were selected for this study. Setting: both groups walked at their self selected speed over a 20 second duration plane surface walk way in trans-tibial prosthesis with PTB socket and SACH foot. The raw data of force and EMG sensors of gait analyzer were filtered, processed and analyzed with help of ‘matlab 7.0. A blue tooth enabled heart rate telemetry system was used for calculating gait efficiency in terms of physiological cost index (PCI. Results: significant differences were found in stride duration, (p=0.003, step duration sound limb (p<0.002, stance duration sound limb (p=0.002, stance duration prosthetic limb (p=0.006 and cadence (p=0.001<0.05, however no difference was found in EMG pattern of vastus lateralis between the two groups. The dynamic weight distribution showed more normalized load on anterior parts of heel and minimum load at calcaneal max in elderly group. The results of vertical ground reaction force found the prosthetic side of elderly group takes more weight than young group during loading response. In comparison, PCI was observed to be greater in case of elderly group. Conclusion: most of difference between two groups could be explained by speed variations and biomechanical limitation of ankle joint due to natural aging process.

  2. Symbolic Tensor Calculus -- Functional and Dynamic Approach

    CERN Document Server

    Woszczyna, A; Czaja, W; Golda, Z A

    2016-01-01

    In this paper, we briefly discuss the dynamic and functional approach to computer symbolic tensor analysis. The ccgrg package for Wolfram Language/Mathematica is used to illustrate this approach. Some examples of applications are attached.

  3. Understanding Microbial Communities: Function, Structure and Dynamics

    Science.gov (United States)

    2015-02-11

    microbial communities: Function, structure and dynamics’, at the Isaac Newton Institute, University of Cambridge, United Kingdom, from August to...dynamics’, at the Isaac Newton Institute, University of Cambridge, United Kingdom, from August to December 2014. The programme involved over 150...Communities: Function, Structure and Dynamics’, at the Isaac Newton Institute, Cambridge University, UK, from 19th August 2014 – 19th December 2014

  4. Funktionelle elektrische Stimulation bei Schwäche der Vorfußhebung // Functional electrical Stimulation and drop foot

    Directory of Open Access Journals (Sweden)

    Pinter MM

    2016-01-01

    Full Text Available Drop foot is a common problem following neurological conditions such as stroke, multiple sclerosis, brain injury and incomplete spinal cord injury, consisting in the inability to lift the foot in the swing phase of the gait cycle. Since dropped foot is frequently associated with spasticity and more complex movement problems affecting the whole person, it can result in tripping and falling.br Functional electrical Stimulation (FES devices are designed to address this problem. The peroneal nerve is stimulated using surface electrodes at its most superficial position in its course, where it passes over the head of the fibula bone. The peroneal nerve stimulation induces activity in the tibialis anterior and peroneous longus muscles, causing dorsiflexion and eversion of the foot. The stimulation is synchronised to the gait using a pressure sensitive heel switch. When weight is taken from the switch, stimulation is given. FES results in an economisation of gait and an improvement of walking speed and walking distance.br Recently, an implantable 4-channel drop foot stimulator with independent electrode adjustment resulting in a more specific stimulation showed an improvement of walking speed and a restoration of gait in patients with stroke. The therapeutic effect might be improved compared with surface stimulation. p bKurzfassung:/b Die Schwäche der Vorfußhebung ist ein weit verbreitetes Problem bei neurologischen Erkrankungen wie Schlaganfall, Multiple Sklerose, Schädelhirntrauma und inkomplettem Querschnittsyndrom und führt zu einer insuffizienten Hebung des Vorfußes in der Schwungphase des Gangzyklus. Vielfach ist die Schwäche der Vorfußhebung assoziert mit Spastizität und komplexeren motorischen Problemen, dies führt zu gehäuftem Stolpern und Stürzen.br Die funktionelle elektrische Stimulation (FES ist eine Therapiemodalität zur Korrektur dieses motorischen Problems. Der N. peronaeus wird mittels Oberflächenelektroden, platziert am

  5. Relationship between foot function and medial knee joint loading in people with medial compartment knee osteoarthritis

    National Research Council Canada - National Science Library

    Levinger, Pazit; Menz, Hylton B; Morrow, Adam D; Bartlett, John R; Feller, Julian A; Bergman, Neil R

    2013-01-01

    Dynamic joint loading, particularly the external knee adduction moment (KAM), is an important surrogate measure for the medio-lateral distribution of force across the knee joint in people with knee osteoarthritis (OA...

  6. [The first ray of the hand and the foot in the primates (II). Functional anatomy].

    Science.gov (United States)

    Kuhlmann, J-N

    2008-08-01

    the articular surfaces: modified cardan for the trapezometacarpal and spiraled trochoid for the cuneometacarpal joint. The man was the sole primate, which had practically no mobility at the level of the first ray of his foot. However, the morphology of his cuneometatarsal articulation was similar to that of the other anthropomorphous primates. The muscles which was inserted on the first metacarpus (or metatarsus) played an active role in the circular amplitude and in the apparent circular amplitude, but very discreet in the effective circumduction. The transversal fascicle of the short abductor of the thumb and of the hallux had a little pronator effect. At the level of the foot, the tendon of the fibular longus had an action of pronation and the abductor longus muscle an action of supination. The metacarpophalangeal and the metatarsophalangeal articulations of all the primates were condylar with laterality movements, which were able to reach 40 degrees and which were then unsteady. The metacarpophalangeal articulation of the man was the single exception. He was the sole one with a really steady thumb.

  7. Particle conservation in dynamical density functional theory.

    Science.gov (United States)

    de Las Heras, Daniel; Brader, Joseph M; Fortini, Andrea; Schmidt, Matthias

    2016-06-22

    We present the exact adiabatic theory for the dynamics of the inhomogeneous density distribution of a classical fluid. Erroneous particle number fluctuations of dynamical density functional theory are absent, both for canonical and grand canonical initial conditions. We obtain the canonical free energy functional, which yields the adiabatic interparticle forces of overdamped Brownian motion. Using an exact and one of the most advanced approximate hard core free energy functionals, we obtain excellent agreement with simulations. The theory applies to finite systems in and out of equilibrium.

  8. Effects of a functional foot orthosis on the knee angle in the sagittal plane of college students in their 20s with flatfoot

    Science.gov (United States)

    Park, KwangYong; Seo, KyoChul

    2015-01-01

    [Purpose] The purpose of this study was to examine the effects of a functional foot orthosis on the knee angle in the sagittal plane of college students in their 20s who had flatfoot. [Subjects and Methods] The subjects of this study were 20 college students diagnosed as having flatfoot. The variations of their knee angle (Q-angle) in the sagittal plane during the stance phase were measured using the VICON Motion System (Vicon, Hansung, Korea) before and while wearing a foot orthosis. The experimental data were analyzed using SPSS 12.0 for Windows. [Results] The Q-angle in the test group during the stance phase showed statistically significant declines on the right and left sides while wearing the foot orthosis during the gait-phases of loading response and midstance. During initial contact, terminal stance, and preswing, the Q-angle also decreased on the right and left sides after wearing the foot orthosis, but the changes were not statistically significant. [Conclusion] The college students with flatfoot exhibited declines in the Q-angle in the sagittal plane while wearing a foot orthosis. In this regard, the application of active gait training using orthotic shoes for long hours is likely to help individuals with flatfoot to achieve normal gait. PMID:25995591

  9. Correlates between kinematics and baropodometric measurements for an integrated in-vivo assessment of the segmental foot function in gait.

    Science.gov (United States)

    Giacomozzi, Claudia; Leardini, Alberto; Caravaggi, Paolo

    2014-08-22

    Baropodometry and multi-segmental foot kinematics are frequently employed to obtain insight into the mechanics of the foot-ground interaction in both basic research and clinical settings. However, nothing hitherto has been reported on the full integration of kinematics with baropodometric parameters, and only a few studies have addressed the association between intersegmental kinematics and plantar loading within specific foot regions. The aim of this study was to understanding the relationships between foot joint mobility and plantar loading by focusing on the correlation between these two measures. An integrated pressure-force-kinematics system was used to measure plantar pressure and rotations between foot segments during the stance phase of walking in 10 healthy subjects. An anatomically-based mask was applied to each footprint to obtain six regions according to the position of the markers; hence each kinematic segment was paired with a corresponding area of the plantar surface. Relationships between segmental motion and relevant baropodometric data were explored by means of correlation analysis. Negative, weak-to-moderate correlations (R(2)segmental range of motion across all foot joints except the Calcaneus-Midfoot. Temporal profiles of sagittal-plane kinematics and baropodometric parameters were well correlated, particularly at the ankle joint. Larger motion in the foot joints during walking was associated with lower plantar pressure in almost all regions. The study helps improve our understanding of the relationship between joint mobility and plantar loading in the healthy foot and represents a critical preliminary analysis before addressing possible clinical applications.

  10. Dynamics of inequalities in geometric function theory

    Directory of Open Access Journals (Sweden)

    Reich Simeon

    2001-01-01

    Full Text Available A domain in the complex plane which is star-like with respect to a boundary point can be approximated by domains which are star-like with respect to interior points. This approximation process can be viewed dynamically as an evolution of the null points of the underlying holomorphic functions from the interior of the open unit disk towards a boundary point. We trace these dynamics analytically in terms of the Alexander–Nevanlinna and Robertson inequalities by using the framework of complex dynamical systems and hyperbolic monotonicity.

  11. Dynamics of cavitating cascades. [transfer functions

    Science.gov (United States)

    Brennen, C. E.; Acosta, A. J.

    1980-01-01

    The unsteady dynamics of cavitating cascades and inducer pumps were studied with a view to understanding (and possibly predicting) the dynamic characteristics of these devices. The chronology of the research is summarized as well as the final conculsions for each task. The construction of a dynamic pump test facility and its use in making experimental measurements of the transfer function is described as well as tests conducted using a scale model of the low pressure liquid oxygen turbopump inducer in the shuttle main engine. Auto-oscillation and unsteady inlet flow characteristics are discussed in addition to blade cavity influence and bubbly cavitation.

  12. Increased Brain Activation for Foot Movement During 70-Day 6 Deg Head-Down Bed Rest (HDBR): Evidence from Functional Magnetic Resonance Imaging (fMRI)

    Science.gov (United States)

    Yuan, P.; Koppelmans, V.; Cassady, K.; Cooke, K.; De Dios, Y. E.; Stepanyan, V.; Szecsy, D.; Gadd, N.; Wood, S. J.; Reuter-Lorenz, P. A.; hide

    2015-01-01

    Bed rest has been widely used as a simulation of weightlessness in studying the effects of microgravity exposure on human physiology and cognition. Changes in muscle function and functional mobility have been reported to be associated with bed rest. Understanding the effect of bed rest on neural control of movement would provide helpful information for spaceflight. In the current study, we evaluated how the brain activation for foot movement changed as a function of bed rest. Eighteen healthy men (aged 25 to 39 years) participated in this HDBR study. They remained continuously in the 6deg head-down tilt position for 70 days. Functional MRI was acquired during 1-Hz right foot tapping, and repeated at 7 time points: 12 days pre-, 8 days pre-, 7 days in-, 50 days in-, 70 days in-, 8 days post-, and 12 days post- HDBR. In all 7 sessions, we observed increased activation in the left motor cortex, right cerebellum and right occipital cortex during foot movement blocks compared to rest. Compared to the pre-HDBR baseline (1st and 2nd sessions), foot movement-induced activation in the left hippocampus increased during HDBR. This increase emerged in the 4th session, enlarged in the 5th session, and remained significant in the 6th and 7th sessions. Furthermore, increased activation relative to the baseline in left precuneus was observed in the 5th, 6th and 7th sessions. In addition, in comparison with baseline, increased activation in the left cerebellum was found in the 4th and 5th sessions, whereas increased activation in the right cerebellum was observed in the 4th, 6th and 7th sessions. No brain region exhibited decreased activation during bed rest compared to baseline. The increase of foot movement related brain activation during HDBR suggests that in a long-term head-down position, more neural control is needed to accomplish foot movements. This change required a couple of weeks to develop in HDBR (between 3rd and 4th sessions), and did not return to baseline even 12

  13. LOCAL ENTROPY FUNCTION OF DYNAMICAL SYSTEM

    Directory of Open Access Journals (Sweden)

    İsmail TOK

    2013-05-01

    Full Text Available In this work, we first,define the entropy function of the topological dynamical system and investigate basic properties of this function without going into details. Let (X,A,T be a probability measure space and consider P = { pl5p2,...,pn} a finite measurable partition of all sub-sets of topological dynamical system (X,T.Then,the quantity H (P = ^ zpt is called the i=1 entropy function of finite measurable partition P.Where f-1 log t if 0 0.If diam(P < s,then the quantity L^ (T = h^ (T - h^ (T,P is called a local entropy function of topological dynamical system (X,T . In conclusion, Let (X,T and (Y,S be two topological dynamical system. If TxS is a transformation defined on the product space (XxY,TxS with (TxS(x , y = (Tx,Sy for all (x,y X x Y.Then L ^^ (TxS = L^d(T + L (S .and, we prove some fundamental properties of this function.

  14. Dynamic Blowout Risk Analysis Using Loss Functions.

    Science.gov (United States)

    Abimbola, Majeed; Khan, Faisal

    2017-08-11

    Most risk analysis approaches are static; failing to capture evolving conditions. Blowout, the most feared accident during a drilling operation, is a complex and dynamic event. The traditional risk analysis methods are useful in the early design stage of drilling operation while falling short during evolving operational decision making. A new dynamic risk analysis approach is presented to capture evolving situations through dynamic probability and consequence models. The dynamic consequence models, the focus of this study, are developed in terms of loss functions. These models are subsequently integrated with the probability to estimate operational risk, providing a real-time risk analysis. The real-time evolving situation is considered dependent on the changing bottom-hole pressure as drilling progresses. The application of the methodology and models are demonstrated with a case study of an offshore drilling operation evolving to a blowout. © 2017 Society for Risk Analysis.

  15. Cavus Foot Surgery

    Science.gov (United States)

    ... All Site Content AOFAS / FootCareMD / Treatments Cavus Foot Surgery Page Content What is a cavus foot? A ... problems. What are the goals of cavus foot surgery? The main goal of surgery is to reduce ...

  16. Infection dynamics of foot-and-mouth disease virus in cattle following intra-nasopharyngeal inoculation or contact exposure

    Science.gov (United States)

    For the purpose of developing an improved experimental model for studies of foot-and-mouth disease virus (FMDV) infection in cattle, three different experimental systems based on natural or simulated-natural virus exposure were compared under standardized experimental conditions. Antemortem infecti...

  17. Club foot

    DEFF Research Database (Denmark)

    Engell, V; Damborg, F; Andersen, M;

    2006-01-01

    The aetiology of congenital club foot is unclear. Although studies on populations, families and twins suggest a genetic component, the mode of inheritance does not comply with distinctive patterns. The Odense-based Danish Twin Registry contains data on all 73,000 twin pairs born in Denmark over t...

  18. Exact four-spinon dynamical correlation function

    CERN Document Server

    Abada, A; Si-Lakhal, B; Seba, S; Abada, As

    1998-01-01

    We discuss some properties of the exact four-spinon dynamical correlation function in the antiferromagnetic spin 1/2 XXX-model the expression of which we derived recently. We show that the region in which it is not identically zero is different from and larger than the spin-wave continuum. We discuss its behavior as a function of the neutron momentum transfer $k$ for fixed values of the neutron energy $\\omega$ and compare it to the one corresponding to the exact two-spinon dynamical correlation function. We show that the overall shapes are quite similar but there are differences that we discuss. Particular is the fact that the symmetry about the axis $k=\\pi$ present in the two-spinon case seems to be lost in the four-spinon one. We finish with concluding remarks.

  19. Robust transient dynamics and brain functions

    Directory of Open Access Journals (Sweden)

    Mikhail I Rabinovich

    2011-06-01

    Full Text Available In the last few decades several concepts of Dynamical Systems Theory (DST have guided psychologists, cognitive scientists, and neuroscientists to rethink about sensory motor behavior and embodied cognition. A critical step in the progress of DST application to the brain (supported by modern methods of brain imaging and multi-electrode recording techniques has been the transfer of its initial success in motor behavior to mental function, i.e., perception, emotion, and cognition. Open questions from research in genetics, ecology, brain sciences, etc. have changed DST itself and lead to the discovery of a new dynamical phenomenon, i.e., reproducible and robust transients that are at the same time sensitive to informational signals. The goal of this review is to describe a new mathematical framework -heteroclinic sequential dynamics- to understand self-organized activity in the brain that can explain certain aspects of robust itinerant behavior. Specifically, we discuss a hierarchy of coarse-grain models of mental dynamics in the form of kinetic equations of modes. These modes compete for resources at three levels: (i within the same modality, (ii among different modalities from the same family (like perception, and (iii among modalities from different families (like emotion and cognition. The analysis of the conditions for robustness, i.e., the structural stability of transient (sequential dynamics, give us the possibility to explain phenomena like the finite capacity of our sequential working memory -a vital cognitive function-, and to find specific dynamical signatures -different kinds of instabilities- of several brain functions and mental diseases.

  20. Actin dynamics shape microglia effector functions.

    Science.gov (United States)

    Uhlemann, Ria; Gertz, Karen; Boehmerle, Wolfgang; Schwarz, Tobias; Nolte, Christiane; Freyer, Dorette; Kettenmann, Helmut; Endres, Matthias; Kronenberg, Golo

    2016-06-01

    Impaired actin filament dynamics have been associated with cellular senescence. Microglia, the resident immune cells of the brain, are emerging as a central pathophysiological player in neurodegeneration. Microglia activation, which ranges on a continuum between classical and alternative, may be of critical importance to brain disease. Using genetic and pharmacological manipulations, we studied the effects of alterations in actin dynamics on microglia effector functions. Disruption of actin dynamics did not affect transcription of genes involved in the LPS-triggered classical inflammatory response. By contrast, in consequence of impaired nuclear translocation of phospho-STAT6, genes involved in IL-4 induced alternative activation were strongly downregulated. Functionally, impaired actin dynamics resulted in reduced NO secretion and reduced release of TNFalpha and IL-6 from LPS-stimulated microglia and of IGF-1 from IL-4 stimulated microglia. However, pathological stabilization of the actin cytoskeleton increased LPS-induced release of IL-1beta and IL-18, which belong to an unconventional secretory pathway. Reduced NO release was associated with decreased cytoplasmic iNOS protein expression and decreased intracellular arginine uptake. Furthermore, disruption of actin dynamics resulted in reduced microglia migration, proliferation and phagocytosis. Finally, baseline and ATP-induced [Ca(2+)]int levels were significantly increased in microglia lacking gelsolin, a key actin-severing protein. Together, the dynamic state of the actin cytoskeleton profoundly and distinctly affects microglia behaviours. Disruption of actin dynamics attenuates M2 polarization by inhibiting transcription of alternative activation genes. In classical activation, the role of actin remodelling is complex, does not relate to gene transcription and shows a major divergence between cytokines following conventional and unconventional secretion.

  1. A functional calculus for the magnetization dynamics

    CERN Document Server

    Tranchida, Julien; Nicolis, Stam

    2016-01-01

    A functional calculus approach is applied to the derivation of evolution equations for the moments of the magnetization dynamics of systems subject to stochastic fields. It allows us to derive a general framework for obtaining the master equation for the stochastic magnetization dynamics, that is applied to both, Markovian and non-Markovian dynamics. The formalism is applied for studying different kinds of interactions, that are of practical relevance and hierarchies of evolution equations for the moments of the distribution of the magnetization are obtained. In each case, assumptions are spelled out, in order to close the hierarchies. These closure assumptions are tested by extensive numerical studies, that probe the validity of Gaussian or non--Gaussian closure Ans\\"atze.

  2. Measuring Dynamic Transfer Functions of Cavitating Pumps

    Science.gov (United States)

    Baun, Daniel

    2007-01-01

    A water-flow test facility has been built to enable measurement of dynamic transfer functions (DTFs) of cavitating pumps and of inducers in such pumps. Originally, the facility was intended for use in an investigation of the effects of cavitation in a rocket-engine low-pressure oxygen turbopump. The facility can also be used to measure DTFs of cavitating pumps in general

  3. Mycetoma foot

    Directory of Open Access Journals (Sweden)

    Somnath Gooptu

    2013-01-01

    Full Text Available Mycetoma is an uncommon chronic granulomatous infective disease of the skin, dermis and subcutaneous tissues predominantly seen in tropical countries. A patient presented to our hospital with the swelling of the left foot with a healed sinus and a painful nodule. He gave a history of sinuses in the left foot from which there was discharge of yellow granules. Culture of the ultrasound guided fine needle aspiration cytology of the nodule revealed growths of Nocardia species. The patient was treated with a multi-drug therapy along with debridement of the painful nodule. He experienced symptomatic relief and a regression of the swelling within the three months of follow-up so far. Due to the relatively slow progression of the disease, patients are diagnosed at a late stage. Hence, emphasis should be placed on health education and the importance of wearing footwear.

  4. Hand, Foot, and Mouth Disease in China: Modeling Epidemic Dynamics of Enterovirus Serotypes and Implications for Vaccination.

    Directory of Open Access Journals (Sweden)

    Saki Takahashi

    2016-02-01

    Full Text Available Hand, foot, and mouth disease (HFMD is a common childhood illness caused by serotypes of the Enterovirus A species in the genus Enterovirus of the Picornaviridae family. The disease has had a substantial burden throughout East and Southeast Asia over the past 15 y. China reported 9 million cases of HFMD between 2008 and 2013, with the two serotypes Enterovirus A71 (EV-A71 and Coxsackievirus A16 (CV-A16 being responsible for the majority of these cases. Three recent phase 3 clinical trials showed that inactivated monovalent EV-A71 vaccines manufactured in China were highly efficacious against HFMD associated with EV-A71, but offered no protection against HFMD caused by CV-A16. To better inform vaccination policy, we used mathematical models to evaluate the effect of prospective vaccination against EV-A71-associated HFMD and the potential risk of serotype replacement by CV-A16. We also extended the model to address the co-circulation, and implications for vaccination, of additional non-EV-A71, non-CV-A16 serotypes of enterovirus.Weekly reports of HFMD incidence from 31 provinces in Mainland China from 1 January 2009 to 31 December 2013 were used to fit multi-serotype time series susceptible-infected-recovered (TSIR epidemic models. We obtained good model fit for the two-serotype TSIR with cross-protection, capturing the seasonality and geographic heterogeneity of province-level transmission, with strong correlation between the observed and simulated epidemic series. The national estimate of the basic reproduction number, R0, weighted by provincial population size, was 26.63 for EV-A71 (interquartile range [IQR]: 23.14, 30.40 and 27.13 for CV-A16 (IQR: 23.15, 31.34, with considerable variation between provinces (however, predictions about the overall impact of vaccination were robust to this variation. EV-A71 incidence was projected to decrease monotonically with higher coverage rates of EV-A71 vaccination. Across provinces, CV-A16 incidence in the

  5. Design and Analysis of New Prosthetic Foot.

    Directory of Open Access Journals (Sweden)

    Kadhim K.Al-Kinani,MSc

    2007-01-01

    Full Text Available There is a variety of artificial foot designs variable for use with prosthetic legs . Most of the design can be divided into two classes, articulated and non-articulated feet. one common non-articulated foot is the SACH . The solid ankle cushion heel foot referred to as the SACH foot has a rigid keelOne key or the key factor in designing a new prosthesis is in the analysis of a patients response This view is the most important because if the foot does not provide functional , practical or cosmetically acceptable characteristics the patient will not feel comfortable with the prosthesis , therefore design and manufacturing a new foot is essential, this foot made from polyethylene, its different shape and characteristics The characteristics deemed important by patients in achieving natural gait motion include:Dorsiflexion Energy return Fatigue test In this study, including all these characteristics test, design fatigue foot tester according to ISO 10328 and design new foot .Also, the testometric crosshead was modified to find dorsiflexion angle and energy return .The fatigue criteria for polymer was proposed, in mathematical solution. Finally , the characteristics of SACH foot was compared with new foot by mathematical solution and used visual basic program and experimental method by different tests. From these test that the new foot is better than SACH foot for all test .

  6. GPU accelerated dynamic functional connectivity analysis for functional MRI data.

    Science.gov (United States)

    Akgün, Devrim; Sakoğlu, Ünal; Esquivel, Johnny; Adinoff, Bryon; Mete, Mutlu

    2015-07-01

    Recent advances in multi-core processors and graphics card based computational technologies have paved the way for an improved and dynamic utilization of parallel computing techniques. Numerous applications have been implemented for the acceleration of computationally-intensive problems in various computational science fields including bioinformatics, in which big data problems are prevalent. In neuroimaging, dynamic functional connectivity (DFC) analysis is a computationally demanding method used to investigate dynamic functional interactions among different brain regions or networks identified with functional magnetic resonance imaging (fMRI) data. In this study, we implemented and analyzed a parallel DFC algorithm based on thread-based and block-based approaches. The thread-based approach was designed to parallelize DFC computations and was implemented in both Open Multi-Processing (OpenMP) and Compute Unified Device Architecture (CUDA) programming platforms. Another approach developed in this study to better utilize CUDA architecture is the block-based approach, where parallelization involves smaller parts of fMRI time-courses obtained by sliding-windows. Experimental results showed that the proposed parallel design solutions enabled by the GPUs significantly reduce the computation time for DFC analysis. Multicore implementation using OpenMP on 8-core processor provides up to 7.7× speed-up. GPU implementation using CUDA yielded substantial accelerations ranging from 18.5× to 157× speed-up once thread-based and block-based approaches were combined in the analysis. Proposed parallel programming solutions showed that multi-core processor and CUDA-supported GPU implementations accelerated the DFC analyses significantly. Developed algorithms make the DFC analyses more practical for multi-subject studies with more dynamic analyses.

  7. The prevention of diabetic foot ulceration: how biomechanical research informs clinical practice

    Directory of Open Access Journals (Sweden)

    Frank E. DiLiberto

    Full Text Available ABSTRACT Background Implementation of interprofessional clinical guidelines for the prevention of neuropathic diabetic foot ulceration has demonstrated positive effects regarding ulceration and amputation rates. Current foot care recommendations are primarily based on research regarding the prevention of ulcer recurrence and focused on reducing the magnitude of plantar stress (pressure overload. Yet, foot ulceration remains to be a prevalent and debilitating consequence of Diabetes Mellitus. There is limited evidence targeting the prevention of first-time ulceration, and there is a need to consider additional factors of plantar stress to supplement current guidelines. Objectives The first purpose of this article is to discuss the biomechanical theory underpinning diabetic foot ulcerations and illustrate how plantar tissue underloading may precede overloading and breakdown. The second purpose of this commentary is to discuss how advances in biomechanical foot modeling can inform clinical practice in the prevention of first-time ulceration. Discussion Research demonstrates that progressive weight-bearing activity programs to address the frequency of plantar stress and avoid underloading do not increase ulceration risk. Multi-segment foot modeling studies indicate that dynamic foot function of the midfoot and forefoot is compromised in people with diabetes. Emerging research demonstrates that implementation of foot-specific exercises may positively influence dynamic foot function and improve plantar stress in people with diabetes. Conclusion Continued work is needed to determine how to best design and integrate activity recommendations and foot-specific exercise programs into the current interprofessional paradigm for the prevention of first-time ulceration in people with Diabetes Mellitus.

  8. Foot posture in people with medial compartment knee osteoarthritis

    Directory of Open Access Journals (Sweden)

    Feller Julian A

    2010-12-01

    Full Text Available Abstract Background Foot posture has long been considered to contribute to the development of lower limb musculoskeletal conditions as it may alter the mechanical alignment and dynamic function of the lower limb. This study compared foot posture in people with and without medial compartment knee osteoarthritis (OA using a range of clinical foot measures. The reliability of the foot measures was also assessed. Methods The foot posture of 32 patients with clinically and radiographically-confirmed OA predominantly in the medial compartment of the knee and 28 asymptomatic age-matched healthy controls was investigated using the foot posture index (FPI, vertical navicular height and drop, and the arch index. Independent t tests and effect size (Cohen's d were used to investigate the differences between the groups in the foot posture measurements. Results Significant differences were found between the control and the knee OA groups in relation to the FPI (1.35 ± 1.43 vs. 2.46 ± 2.18, p = 0.02; d = 0.61, medium effect size, navicular drop (0.02 ± 0.01 vs. 0.03 ± 0.01, p = 0.01; d = 1.02, large effect size and the arch index (0.22 ± 0.04 vs. 0.26 ± 0.04, p = 0.04; d = 1.02, large effect size. No significant difference was found for vertical navicular height (0.24 ± 0.03 vs. 0.23 ± 0.03, p = 0.54; d = 0.04, negligible effect size. Conclusion People with medial compartment knee OA exhibit a more pronated foot type compared to controls. It is therefore recommended that the assessment of patients with knee OA in clinical practice should include simple foot measures, and that the potential influence of foot structure and function on the efficacy of foot orthoses in the management of medial compartment knee OA be further investigated.

  9. Relationships between the Foot Posture Index and foot kinematics during gait in individuals with and without patellofemoral pain syndrome

    Directory of Open Access Journals (Sweden)

    Crossley Kay M

    2011-03-01

    Full Text Available Abstract Background Foot posture assessment is commonly undertaken in clinical practice for the evaluation of individuals with patellofemoral pain syndrome (PFPS, particularly when considering prescription of foot orthoses. However, the validity of static assessment to provide insight into dynamic function in individuals with PFPS is unclear. This study was designed to evaluate the extent to which a static foot posture measurement tool (the Foot Posture Index - FPI can provide insight into kinematic variables associated with foot pronation during level walking in individuals with PFPS and asymptomatic controls. Methods Twenty-six individuals (5 males, 21 females with PFPS aged 25.1 ± 4.6 years and 20 control participants (4 males, 16 females aged 23.4 ± 2.3 years were recruited into the study. Each participant underwent clinical evaluation of the FPI and kinematic analysis of the rearfoot and forefoot during walking using a three-dimensional motion analysis system. The association of the FPI score with rearfoot eversion, forefoot dorsiflexion, and forefoot abduction kinematic variables (magnitude, timing of peak and range of motion were evaluated using partial correlation coefficient statistics with gait velocity entered as a covariate. Results A more pronated foot type as measured by the FPI was associated with greater peak forefoot abduction (r = 0.502, p = 0.013 and earlier peak rearfoot eversion relative to the laboratory (r = -0.440, p = 0.031 in the PFPS group, and greater rearfoot eversion range of motion relative to the laboratory (r = 0.614, p = 0.009 in the control group. Conclusion In both individuals with and without PFPS, there was fair to moderate association between the FPI and some parameters of dynamic foot function. Inconsistent findings between the PFPS and control groups indicate that pathology may play a role in the relationship between static foot posture and dynamic function. The fair association between pronated foot

  10. Dynamic Responsive Systems for Catalytic Function.

    Science.gov (United States)

    Vlatković, Matea; Collins, Beatrice S L; Feringa, Ben L

    2016-11-21

    Responsive systems have recently gained much interest in the scientific community in attempts to mimic dynamic functions in biological systems. One of the fascinating potential applications of responsive systems lies in catalysis. Inspired by nature, novel responsive catalytic systems have been built that show analogy with allosteric regulation of enzymes. The design of responsive catalytic systems allows control of catalytic activity and selectivity. In this Review, advances in the field over the last four decades are discussed and a comparison is made amongst the dynamic responsive systems based on the principles underlying their catalytic mechanisms. The catalyst systems are sorted according to the triggers used to achieve control of the catalytic activity and the distinct catalytic reactions illustrated. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Effect of foot-and-mouth disease virus on the frequency, phenotype and function of circulating dendritic cells in cattle

    Science.gov (United States)

    Foot-and-mouth disease virus (FMDV) is a highly contagious virus that causes one of the most devastating diseases in cloven-hoofed animals. Disease symptoms in FMDV-infected animals appear within 2 to 3 days of exposure. Dendritic cells (DC) play an essential role in protective immune responses agai...

  12. Proteins with Novel Structure, Function and Dynamics

    Science.gov (United States)

    Pohorille, Andrew

    2014-01-01

    Recently, a small enzyme that ligates two RNA fragments with the rate of 10(exp 6) above background was evolved in vitro (Seelig and Szostak, Nature 448:828-831, 2007). This enzyme does not resemble any contemporary protein (Chao et al., Nature Chem. Biol. 9:81-83, 2013). It consists of a dynamic, catalytic loop, a small, rigid core containing two zinc ions coordinated by neighboring amino acids, and two highly flexible tails that might be unimportant for protein function. In contrast to other proteins, this enzyme does not contain ordered secondary structure elements, such as alpha-helix or beta-sheet. The loop is kept together by just two interactions of a charged residue and a histidine with a zinc ion, which they coordinate on the opposite side of the loop. Such structure appears to be very fragile. Surprisingly, computer simulations indicate otherwise. As the coordinating, charged residue is mutated to alanine, another, nearby charged residue takes its place, thus keeping the structure nearly intact. If this residue is also substituted by alanine a salt bridge involving two other, charged residues on the opposite sides of the loop keeps the loop in place. These adjustments are facilitated by high flexibility of the protein. Computational predictions have been confirmed experimentally, as both mutants retain full activity and overall structure. These results challenge our notions about what is required for protein activity and about the relationship between protein dynamics, stability and robustness. We hypothesize that small, highly dynamic proteins could be both active and fault tolerant in ways that many other proteins are not, i.e. they can adjust to retain their structure and activity even if subjected to mutations in structurally critical regions. This opens the doors for designing proteins with novel functions, structures and dynamics that have not been yet considered.

  13. A dynamic model of the windlass mechanism of the foot: evidence for early stance phase preloading of the plantar aponeurosis.

    Science.gov (United States)

    Caravaggi, Paolo; Pataky, Todd; Goulermas, John Y; Savage, Russel; Crompton, Robin

    2009-08-01

    In the present study we have estimated the temporal elongation of the plantar aponeurosis (PA) during normal walking using a subject-specific multi-segment rigid-body model of the foot. As previous studies have suggested that muscular forces at the ankle can pre-load the PA prior to heel-strike, the main purpose of the current study was to test, through modelling, whether there is any tension present in the PA during early stance phase. Reflective markers were attached to bony landmarks to track the kinematics of the calcaneus, metatarsus and toes during barefoot walking. Ultrasonography measurements were performed on three subjects to determine both the location of the origin of the PA on the plantar aspect of the calcaneus, and the radii of the metatarsal heads. Starting with the foot in a neutral, unloaded position, inverse kinematics allowed calculation of the tension in the five slips of the PA during the whole duration of the stance phase. The results show that the PA experienced tension significantly above rest during early stance phase in all subjects (P<0.01), thus providing support for the PA-preloading hypothesis. The amount of preloading and the maximum elongation of the slips of the PA decreased from medial to lateral. The mean maximum tension exerted by the PA was 1.5 BW (body weight) over the three subjects.

  14. Combining Molecular Dynamics and Density Functional Theory

    Science.gov (United States)

    Kaxiras, Efthimios

    2015-03-01

    The time evolution of a system consisting of electrons and ions is often treated in the Born-Oppenheimer approximation, with electrons in their instantaneous ground state. This approach cannot capture many interesting processes that involved excitation of electrons and its effects on the coupled electron-ion dynamics. The time scale needed to accurately resolve the evolution of electron dynamics is atto-seconds. This poses a challenge to the simulation of important chemical processes that typically take place on time scales of pico-seconds and beyond, such as reactions at surfaces and charge transport in macromolecules. We will present a methodology based on time-dependent density functional theory for electrons, and classical (Ehrenfest) dynamics for the ions, that successfully captures such processes. We will give a review of key features of the method and several applications. These illustrate how the atomic and electronic structure evolution unravels the elementary steps that constitute a chemical reaction. In collaboration with: G. Kolesov, D. Vinichenko, G. Tritsaris, C.M. Friend, Departments of Physics and of Chemistry and Chemical Biology.

  15. Triceps surae muscle-tendon unit length changes as a function of ankle joint angles and contraction levels: the effect of foot arch deformation.

    Science.gov (United States)

    Iwanuma, Soichiro; Akagi, Ryota; Hashizume, Satoru; Kanehisa, Hiroaki; Yanai, Toshimasa; Kawakami, Yasuo

    2011-09-23

    The purpose of this study was to clarify how foot deformation affects the relationship between triceps surae muscle-tendon unit (MTU) length and ankle joint angle. For six women and six men a series of sagittal magnetic resonance (MR) images of the right foot were taken, and changes in MTU length (the displacement of the calcaneal tuberosity), foot arch angle, and ankle joint angle were measured. In the passive session, each subject's ankle joint was secured at 10° dorsiflexed position, neutral position (NP), and 10° and 20° plantar flexed positions while MR images were acquired. In the active session, each subject was requested to perform submaximal isometric plantar flexions (30%, 60%, and 80% of voluntary maximum) at NP. The changes in MTU length in each trial were estimated by two different formulae reported previously. The changes of the measured MTU length as a function of ankle joint angles observed in all trials of the active session were significantly (ptriceps surae MTU length-ankle joint angle relationship during plantar flexion.

  16. Function of clinical nursing intervention on improving diabetic foot prognosis%糖尿病足的临床护理干预应用

    Institute of Scientific and Technical Information of China (English)

    张艳; 黄秀桃; 王智慧; 叶秀云

    2014-01-01

    目的:探讨临床护理干预在预防糖尿病足发展中的影响作用。方法:选取医院内科糖尿病足住院患者40例,采用临床护理干预观察1个月后,根据Wagner分级法进行分级。结果:治愈37例,好转3例。结论:临床护理干预在预防糖尿病足进展中有着重要作用。%To explore the function of a clinical nursing intervention on t he prevention from diabetic foot development.Methods:Totaly 40 patients with diabetes foot in the department of endocrinology were selected and they received the clinical nursing intervention, Al the patients were observed for one month, and the results were analyzed according to Wagner classification.Results:According to the Wagner classification, Cured 37 cases, improved in 3 cases.Conclusions:The clinical nursing intervention has played an important role in the prevention from diabetic foot progress.

  17. The use of gait analysis in the treatment of pediatric foot and ankle disorders.

    Science.gov (United States)

    Theologis, Tim; Stebbins, Julie

    2010-06-01

    Assessment of foot pathology during walking should form an integral part of the clinical evaluation of children. Simple observation and video recording have limitations and are not quantifiable. Three-dimensional analysis of foot motion during walking can provide invaluable information on the dynamic function of the foot and can contribute to clinical decision making. As motion analysis technology advances, the accuracy and reliability of the dynamic assessment of the foot during walking will increase further, allowing clinicians to rely confidently on this information during patient assessment and the study of treatment outcomes. It is logical to expect that objective and quantifiable assessment of gait should be undertaken before and after treatment that sets gait improvement as one of its aims. Copyright 2010 Elsevier Inc. All rights reserved.

  18. A new method to normalize plantar pressure measurements for foot size and foot progression angle.

    NARCIS (Netherlands)

    Keijsers, N.L.; Stolwijk, N.M.; Nienhuis, B.; Duysens, J.E.J.

    2009-01-01

    Plantar pressure measurement provides important information about the structure and function of the foot and is a helpful tool to evaluate patients with foot complaints. In general, average and maximum plantar pressure of 6-11 areas under the foot are used to compare groups of subjects. However,

  19. Biodiversity and ecosystem functioning in dynamic landscapes.

    Science.gov (United States)

    Brose, Ulrich; Hillebrand, Helmut

    2016-05-19

    The relationship between biodiversity and ecosystem functioning (BEF) and its consequence for ecosystem services has predominantly been studied by controlled, short-term and small-scale experiments under standardized environmental conditions and constant community compositions. However, changes in biodiversity occur in real-world ecosystems with varying environments and a dynamic community composition. In this theme issue, we present novel research on BEF in such dynamic communities. The contributions are organized in three sections on BEF relationships in (i) multi-trophic diversity, (ii) non-equilibrium biodiversity under disturbance and varying environmental conditions, and (iii) large spatial and long temporal scales. The first section shows that multi-trophic BEF relationships often appear idiosyncratic, while accounting for species traits enables a predictive understanding. Future BEF research on complex communities needs to include ecological theory that is based on first principles of species-averaged body masses, stoichiometry and effects of environmental conditions such as temperature. The second section illustrates that disturbance and varying environments have direct as well as indirect (via changes in species richness, community composition and species' traits) effects on BEF relationships. Fluctuations in biodiversity (species richness, community composition and also trait dominance within species) can severely modify BEF relationships. The third section demonstrates that BEF at larger spatial scales is driven by different variables. While species richness per se and community biomass are most important, species identity effects and community composition are less important than at small scales. Across long temporal scales, mass extinctions represent severe changes in biodiversity with mixed effects on ecosystem functions. Together, the contributions of this theme issue identify new research frontiers and answer some open questions on BEF relationships

  20. Flat Feet, Happy Feet? Comparison of the Dynamic Plantar Pressure Distribution and Static Medial Foot Geometry between Malawian and Dutch Adults

    NARCIS (Netherlands)

    Stolwijk, N.M.; Duysens, J.E.J.; Louwerens, J.W.; Ven, Y.H. van de; Keijsers, N.L.

    2013-01-01

    In contrast to western countries, foot complaints are rare in Africa. This is remarkable, as many African adults walk many hours each day, often barefoot or with worn-out shoes. The reason why Africans can withstand such loading without developing foot complaints might be related to the way the foot

  1. Flat Feet, Happy Feet? Comparison of the Dynamic Plantar Pressure Distribution and Static Medial Foot Geometry between Malawian and Dutch Adults

    NARCIS (Netherlands)

    Stolwijk, N.M.; Duysens, J.E.J.; Louwerens, J.W.; Ven, Y.H. van de; Keijsers, N.L.

    2013-01-01

    In contrast to western countries, foot complaints are rare in Africa. This is remarkable, as many African adults walk many hours each day, often barefoot or with worn-out shoes. The reason why Africans can withstand such loading without developing foot complaints might be related to the way the foot

  2. Foot amputation - discharge

    Science.gov (United States)

    Amputation - foot - discharge; Trans-metatarsal amputation - discharge ... You have had a foot amputation. You may have had an accident, or your foot may have had an infection or disease and doctors could not save ...

  3. Functional thermo-dynamics: a generalization of dynamic density functional theory to non-isothermal situations.

    Science.gov (United States)

    Anero, Jesús G; Español, Pep; Tarazona, Pedro

    2013-07-21

    We present a generalization of Density Functional Theory (DFT) to non-equilibrium non-isothermal situations. By using the original approach set forth by Gibbs in his consideration of Macroscopic Thermodynamics (MT), we consider a Functional Thermo-Dynamics (FTD) description based on the density field and the energy density field. A crucial ingredient of the theory is an entropy functional, which is a concave functional. Therefore, there is a one to one connection between the density and energy fields with the conjugate thermodynamic fields. The connection between the three levels of description (MT, DFT, FTD) is clarified through a bridge theorem that relates the entropy of different levels of description and that constitutes a generalization of Mermin's theorem to arbitrary levels of description whose relevant variables are connected linearly. Although the FTD level of description does not provide any new information about averages and correlations at equilibrium, it is a crucial ingredient for the dynamics in non-equilibrium states. We obtain with the technique of projection operators the set of dynamic equations that describe the evolution of the density and energy density fields from an initial non-equilibrium state towards equilibrium. These equations generalize time dependent density functional theory to non-isothermal situations. We also present an explicit model for the entropy functional for hard spheres.

  4. Cardiac mitochondria exhibit dynamic functional clustering

    Directory of Open Access Journals (Sweden)

    Felix Tobias Kurz

    2014-09-01

    Full Text Available Multi-oscillatory behavior of mitochondrial inner membrane potential ΔΨm in self-organized cardiac mitochondrial networks can be triggered by metabolic or oxidative stress. Spatio-temporal analyses of cardiac mitochondrial networks have shown that mitochondria are heterogeneously organized in synchronously oscillating clusters in which the mean cluster frequency and size are inversely correlated, thus suggesting a modulation of cluster frequency through local inter-mitochondrial coupling. In this study, we propose a method to examine the mitochondrial network's topology through quantification of its dynamic local clustering coefficients. Individual mitochondrial ΔΨm oscillation signals were identified for each cardiac myocyte and cross-correlated with all network mitochondria using previously described methods (Kurz et al., 2010. Time-varying inter-mitochondrial connectivity, defined for mitochondria in the whole network whose signals are at least 90% correlated at any given time point, allowed considering functional local clustering coefficients. It is shown that mitochondrial clustering in isolated cardiac myocytes changes dynamically and is significantly higher than for random mitochondrial networks that are constructed using the Erdös-Rényi model based on the same sets of vertices. The network's time-averaged clustering coefficient for cardiac myocytes was found to be 0.500 ± 0.051 (N=9 versus 0.061 ± 0.020 for random networks, respectively. Our results demonstrate that cardiac mitochondria constitute a network with dynamically connected constituents whose topological organization is prone to clustering. Cluster partitioning in networks of coupled oscillators has been observed in scale-free and chaotic systems and is therefore in good agreement with previous models of cardiac mitochondrial networks (Aon et al., 2008.

  5. Relativistic dynamics, Green function and pseudodifferential operators

    CERN Document Server

    Cirilo-Lombardo, Diego Julio

    2016-01-01

    The central role played by pseudodifferential operators in relativistic dynamics is very well know. In this work, operators as the Schrodinger one (e.g: square root) are treated from the point of view of the non-local pseudodifferential Green functions. Starting from the explicit construction of the Green (semigroup) theoretical kernel, a theorem linking the integrability conditions and their dependence on the spacetime dimensions is given. Relativistic wave equations with arbitrary spin and the causality problem are discussed with the algebraic interpretation of the radical operator and their relation with coherent and squeezed states. Also we perform by mean of pure theoretical procedures (based in physical concepts and symmetry) the relativistic position operator which satisfies the conditions of integrability : it is non-local, Lorentz invariant and does not have the same problems as the "local"position operator proposed by Newton and Wigner. Physical examples, as Zitterbewegung and rogue waves, are prese...

  6. Characterizing multisegment foot kinematics during gait in diabetic foot patients

    Directory of Open Access Journals (Sweden)

    Denti Paolo

    2009-10-01

    Full Text Available Abstract Background The prevalence of diabetes mellitus has reached epidemic proportions, this condition may result in multiple and chronic invalidating long term complications. Among these, the diabetic foot, is determined by the simultaneous presence of both peripheral neuropathy and vasculopathy that alter the biomechanics of the foot with the formation of callosity and ulcerations. To diagnose and treat the diabetic foot is crucial to understand the foot complex kinematics. Most of gait analysis protocols represent the entire foot as a rigid body connected to the shank. Nevertheless the existing multisegment models cannot completely decipher the impairments associated with the diabetic foot. Methods A four segment foot and ankle model for assessing the kinematics of the diabetic foot was developed. Ten normal subjects and 10 diabetics gait patterns were collected and major sources of variability were tested. Repeatability analysis was performed both on a normal and on a diabetic subject. Direct skin marker placement was chosen in correspondence of 13 anatomical landmarks and an optoelectronic system was used to collect the data. Results Joint rotation normative bands (mean plus/minus one standard deviation were generated using the data of the control group. Three representative strides per subject were selected. The repeatability analysis on normal and pathological subjects results have been compared with literature and found comparable. Normal and pathological gait have been compared and showed major statistically significant differences in the forefoot and midfoot dorsi-plantarflexion. Conclusion Even though various biomechanical models have been developed so far to study the properties and behaviour of the foot, the present study focuses on developing a methodology for the functional assessment of the foot-ankle complex and for the definition of a functional model of the diabetic neuropathic foot. It is, of course, important to evaluate

  7. Microtransitions and the dynamics of family functioning.

    Science.gov (United States)

    Everri, Marina; Fruggeri, Laura; Molinari, Luisa

    2014-03-01

    This paper presents a qualitative observational study aimed at exploring microtransitions in the relational dynamics of family functioning when the children are adolescents. Three concurrent levels were considered central for family functioning in this period: the acknowledgment of emerging competences, the redefinition of the power structure, and the regulation of interpersonal distances. Twenty-eight non-clinical Italian families with at least one adolescent child were interviewed and video-recorded in their homes. A stance-taking process analysis was carried out on the family interactive sequences arising in the course of the interviews. This analysis was based on the stances taken by all family members in relation to their reciprocal evaluations, positions, and alignments, which allowed us to point out the interlocking of competences, power and distances. Out of all the possible theoretical combinations of these three dimensions, we identified four forms of interaction. In two forms, the emerging changes were not incorporated in the families' interactive repertoires by either reconfirming family stability or resisting family changes. In these ways of interacting competences, power, and distances were not reorganized. In the other two forms, instead, family microtransitions were observable in the extent to which family members either explored family changes or legitimated family reorganizations. In these processes, they could redefine and readdress their ways of interacting.

  8. Ambulatory Function and Perception of Confidence in Persons with Stroke with a Custom-Made Hinged versus a Standard Ankle Foot Orthosis.

    Science.gov (United States)

    Slijper, Angélique; Danielsson, Anna; Willén, Carin

    2012-01-01

    Objective. The aim was to compare walking with an individually designed dynamic hinged ankle foot orthosis (DAFO) and a standard carbon composite ankle foot orthosis (C-AFO). Methods. Twelve participants, mean age 56 years (range 26-72), with hemiparesis due to stroke were included in the study. During the six-minute walk test (6MW), walking velocity, the Physiological Cost Index (PCI), and the degree of experienced exertion were measured with a DAFO and C-AFO, respectively, followed by a Stairs Test velocity and perceived confidence was rated. Results. The mean differences in favor for the DAFO were in 6MW 24.3 m (95% confidence interval [CI] 4.90, 43.76), PCI -0.09 beats/m (95% CI -0.27, 0.95), velocity 0.04 m/s (95% CI -0.01, 0.097), and in the Stairs Test -11.8 s (95% CI -19.05, -4.48). All participants except one perceived the degree of experienced exertion lower and felt more confident when walking with the DAFO. Conclusions. Wearing a DAFO resulted in longer walking distance and faster stair climbing compared to walking with a C-AFO. Eleven of twelve participants felt more confident with the DAFO, which may be more important than speed and distance and the most important reason for prescribing an AFO.

  9. Ambulatory Function and Perception of Confidence in Persons with Stroke with a Custom-Made Hinged versus a Standard Ankle Foot Orthosis

    Directory of Open Access Journals (Sweden)

    Angélique Slijper

    2012-01-01

    Full Text Available Objective. The aim was to compare walking with an individually designed dynamic hinged ankle foot orthosis (DAFO and a standard carbon composite ankle foot orthosis (C-AFO. Methods. Twelve participants, mean age 56 years (range 26–72, with hemiparesis due to stroke were included in the study. During the six-minute walk test (6MW, walking velocity, the Physiological Cost Index (PCI, and the degree of experienced exertion were measured with a DAFO and C-AFO, respectively, followed by a Stairs Test velocity and perceived confidence was rated. Results. The mean differences in favor for the DAFO were in 6MW 24.3 m (95% confidence interval [CI] 4.90, 43.76, PCI −0.09 beats/m (95% CI −0.27, 0.95, velocity 0.04 m/s (95% CI −0.01, 0.097, and in the Stairs Test −11.8 s (95% CI −19.05, −4.48. All participants except one perceived the degree of experienced exertion lower and felt more confident when walking with the DAFO. Conclusions. Wearing a DAFO resulted in longer walking distance and faster stair climbing compared to walking with a C-AFO. Eleven of twelve participants felt more confident with the DAFO, which may be more important than speed and distance and the most important reason for prescribing an AFO.

  10. Dynamics of biomolecules, ligand binding & biological functions

    Science.gov (United States)

    Yi, Myunggi

    Proteins are flexible and dynamic. One static structure alone does not often completely explain biological functions of the protein, and some proteins do not even have high resolution structures. In order to provide better understanding to the biological functions of nicotinic acetylcholine receptor, Diphtheria toxin repressor and M2 proton channel, the dynamics of these proteins are investigated using molecular modeling and molecular dynamics (MD) simulations. With absence of high resolution structure of alpha7 receptor, the homology models of apo and cobra toxin bound forms have been built. From the MD simulations of these model structures, we observed one subunit of apo simulation moved away from other four subunits. With local movement of flexible loop regions, the whole subunit tilted clockwise. These conformational changes occurred spontaneously, and were strongly correlated with the conformational change when the channel is activated by agonists. Unlike other computational studies, we directly compared our model of open conformation with the experimental data. However, the subunits of toxin bound form were stable, and conformational change is restricted by the bound cobra toxin. These results provide activation and inhibition mechanisms of alpha7 receptors and a possible explanation for intermediate conductance of the channel. Intramolecular complex of SH3-like domain with a proline-rich (Pr) peptide segment in Diphtheria toxin repressor (DtxR) is stabilized in inactive state. Upon activation of DtxR by transition metal binding, this intramolecular complex should be dissociated. The dynamics of this intramolecular complex is investigated using MD simulations and NMR spectroscopy. We observed spontaneous opening and closing motions of the Pr segment binding pockets in both Pr-SH3 and SH3 simulations. The MD simulation results and NMR relaxation data suggest that the Pr segment exhibits a binding ↔ unbinding equilibrium. Despite a wealth of experimental

  11. PROMIS Pain Interference and Physical Function Scores Correlate With the Foot and Ankle Ability Measure (FAAM) in Patients With Hallux Valgus.

    Science.gov (United States)

    Nixon, Devon C; McCormick, Jeremy J; Johnson, Jeffrey E; Klein, Sandra E

    2017-08-23

    Traditional patient-reported outcome instruments like the Foot and Ankle Ability Measure (FAAM) quantify patient disability but often are limited by responder burden and incomplete questionnaires. The Patient-Reported Outcome Measurement Information System (PROMIS) overcomes such obstacles through computer-adaptive technology and can capture outcome data from various domains including physical and psychosocial function. Prior work has compared the FAAM with PROMIS physical function; however, there is little evidence comparing the association between foot and ankle-specific tools like the FAAM with more general outcomes measures of PROMIS pain interference and depression in foot and ankle conditions. (1) We asked whether there was a relationship between FAAM Activities of Daily Living (ADL) scores with PROMIS physical function, pain interference, and depression in patients with hallux valgus. (2) Additionally, we asked if we could identify specific factors that are associated with variance in FAAM and PROMIS physical function scores in patients with hallux valgus. Eighty-five new patients with either a primary or secondary diagnosis of hallux valgus based on clinic billing codes from July 2015 to February 2016 were retrospectively identified. Patients completed FAAM ADL paper-based surveys and electronic PROMIS questionnaires for physical function, pain interference, and depression from new patient visits at a single time. Spearman rho correlations were performed between FAAM ADL and PROMIS scores. Analyses then were used to identify differences in FAAM ADL and PROMIS physical function measures based on demographic variables. Stepwise linear regressions then determined which demographic and/or outcome variable(s) accounted for the variance in FAAM ADL and PROMIS physical function scores. FAAM scores correlated strongly with PROMIS physical function (r = 0.70, p < 0.001), moderately with PROMIS pain interference (r = -0.65, p < 0.001), and weakly with PROMIS

  12. The influence of foot orthoses on foot mobility magnitude and arch height index in adults with flexible flat feet.

    Science.gov (United States)

    Sheykhi-Dolagh, Roghaye; Saeedi, Hassan; Farahmand, Behshid; Kamyab, Mojtaba; Kamali, Mohammad; Gholizadeh, Hossein; Derayatifar, Amir A; Curran, Sarah

    2015-06-01

    Flexible flat foot is described as a reduction in the height of the medial longitudinal arch and may occur from abnormal foot pronation. A foot orthosis is thought to modify and control excessive pronation and improve arch height. To compare the immediate effect of three types of orthoses on foot mobility and the arch height index in subjects with flexible flat feet. A quasi-experimental study. The dorsal arch height, midfoot width, foot mobility and arch height index were assessed in 20 participants with flexible flat feet (mean age = 23.2 ± 3 years) for three different foot orthosis conditions: soft, semi-rigid and rigid University of California Biomechanics Laboratory (UCBL). Maximum midfoot width at 90% with arch mobility in the coronal plane was shown in the semi-rigid orthosis condition. The semi-rigid orthosis resulted in the highest mean foot mobility in 90% of weight bearing, and the rigid orthosis (UCBL) had the lowest mean foot mobility. The soft orthosis resulted in foot mobility between that of the rigid and the semi-rigid orthosis. UCBL orthosis showed the highest arch height index, and the semi-rigid orthosis showed the lowest mean arch height index. Due to its rigid structure and long medial-lateral walls, the UCBL orthosis appears to limit foot mobility. Therefore, it is necessary to make an orthosis that facilitates foot mobility in the normal range of the foot arch. Future studies should address the dynamic mobility of the foot with using various types of foot orthoses. Although there are many studies focussed on flat foot and the use of foot orthoses, the mechanism of action is still unclear. This study explored foot mobility and the influence of foot orthoses and showed that a more rigid foot orthosis should be selected based on foot mobility. © The International Society for Prosthetics and Orthotics 2014.

  13. Chondroblastoma of the foot.

    Science.gov (United States)

    Fink, B R; Temple, H T; Chiricosta, F M; Mizel, M S; Murphey, M D

    1997-04-01

    A total of 322 cases of chondroblastoma were referred to the Armed Forces Institute of Pathology between 1960 and 1990. Ten additional cases of chondroblastoma were treated at Walter Reed Army Medical Center between 1985 and 1993. Forty-two of these involved the foot, two of which were treated at Walter Reed Army Medical Center. Patients with chondroblastoma of the foot were male in 35 (81%) cases, with a mean age of 25.5 years, which was significantly different from the mean age of 17.3 years in patients with chondroblastoma of the long bones (P Chondroblastoma of the foot is most commonly found in the posterior subchondral areas of the talus and calcaneus as well as in the calcaneal apophysis. Radiographically, the lesion was associated with an articular surface or apophyseal area in all cases and appeared radiolucent, with little to no matrix production. The margins were generally well defined. Cystic features were noted grossly and histologically in 24 (57%) specimens, a feature seen in only 21% of all chondroblastomas overall. Treatment consists of thorough curetting and bone grafting with good oncologic and functional results.

  14. Effects of a multichannel dynamic functional electrical stimulation system on hemiplegic gait and muscle forces.

    Science.gov (United States)

    Qian, Jing-Guang; Rong, Ke; Qian, Zhenyun; Wen, Chen; Zhang, Songning

    2015-11-01

    [Purpose] The purpose of the study was to design and implement a multichannel dynamic functional electrical stimulation system and investigate acute effects of functional electrical stimulation of the tibialis anterior and rectus femoris on ankle and knee sagittal-plane kinematics and related muscle forces of hemiplegic gait. [Subjects and Methods] A multichannel dynamic electrical stimulation system was developed with 8-channel low frequency current generators. Eight male hemiplegic patients were trained for 4 weeks with electric stimulation of the tibia anterior and rectus femoris muscles during walking, which was coupled with active contraction. Kinematic data were collected, and muscle forces of the tibialis anterior and rectus femoris of the affected limbs were analyzed using a musculoskelatal modeling approach before and after training. A paired sample t-test was used to detect the differences between before and after training. [Results] The step length of the affected limb significantly increased after the stimulation was applied. The maximum dorsiflexion angle and maximum knee flexion angle of the affected limb were both increased significantly during stimulation. The maximum muscle forces of both the tibia anterior and rectus femoris increased significantly during stimulation compared with before functional electrical stimulation was applied. [Conclusion] This study established a functional electrical stimulation strategy based on hemiplegic gait analysis and musculoskeletal modeling. The multichannel functional electrical stimulation system successfully corrected foot drop and altered circumduction hemiplegic gait pattern.

  15. Dynamics and zeta functions on conformally compact manifolds

    CERN Document Server

    Rowlett, Julie; Tapie, Samuel

    2011-01-01

    In this note, we study the dynamics and associated zeta functions of conformally compact manifolds with variable negative sectional curvatures. We begin with a discussion of a larger class of manifolds known as convex co-compact manifolds with variable negative curvature. Applying results from dynamics on these spaces, we obtain optimal meromorphic extensions of weighted dynamical zeta functions and asymptotic counting estimates for the number of weighted closed geodesics. A meromorphic extension of the standard dynamical zeta function and the prime orbit theorem follow as corollaries. Finally, we investigate interactions between the dynamics and spectral theory of these spaces.

  16. The Relationship with Balance, Foot Posture, and Foot Size in School of Physical Education and Sports Students

    Science.gov (United States)

    Irez, Gonul Babayigit

    2014-01-01

    The aim of this study is to investigate the relationship of foot posture and foot size with balance. A hundred and thirteen healthy volunteers were recruited from undergraduate students (Male = 74, Female = 37, age range 18-22). The Foot Posture Index (FPI-6), anthropometric measurements, dynamic balance and static balance measurements were done…

  17. Outdoor dynamic subject-specific evaluation of internal stresses in the residual limb: hydraulic energy-stored prosthetic foot compared to conventional energy-stored prosthetic feet.

    Science.gov (United States)

    Portnoy, Sigal; Kristal, Anat; Gefen, Amit; Siev-Ner, Itzhak

    2012-01-01

    The prosthetic foot plays an important role in propelling, breaking, balancing and supporting body loads while the amputee ambulates on different grounds. It is therefore important to quantify the effect of the prosthetic foot mechanism on biomechanical parameters, in order to prevent pressure ulcers and deep tissue injury. Our aim was to monitor the internal stresses in the residuum of transtibial amputation (TTA) prosthetic-users ambulating on different terrains, which the amputees encounter during their daily activities, i.e. paved floor, grass, ascending and descending stairs and slope. We specifically aimed to compare between the internal stresses in the TTA residuum of amputees ambulating with a novel hydraulic prosthetic foot compared to conventional energy storage and return (ESR) prosthetic feet. Monitoring of internal stresses was accomplished using a portable subject-specific real-time internal stress monitor. We found significant decrease (phydraulic foot, compared to walking with ESR feet. The loading rate calculated while ambulating with the hydraulic foot was at least three times lower than the loading rate calculated while ambulating with the ESR foot. Although the average decrease in internal stresses was ≈ 2-fold larger when replacing single-toe ESR feet with the hydraulic foot than when replacing split-toed ESR feet with the hydraulic foot, the differences were statistically insignificant. Our findings suggest that using a hydraulic prosthetic foot may protect the distal tibial end of the TTA residuum from high stresses, therefore preventing pressure-related injury and pain.

  18. 中药泡足联合健康教育对糖尿病足患者下肢血管功能及生活质量的影响%An analysis of the TCM medicine foot bath plus health education for lower extremity vascular function and quality of life in patients with diabetic foot

    Institute of Scientific and Technical Information of China (English)

    李育静

    2015-01-01

    目的:研究中药泡足联合健康教育对糖尿病足患者下肢血管功能及生活质量的影响。方法:选择2013年6月-2014年8月期间我院收治的60例糖尿病足患者纳入研究,随机分为两组,观察组接受中药泡足联合健康教育,对照组接受常规护理,比较两组患者的下肢血管功能以及生活质量。结果:观察组患者的 IMT、PSV 低于对照组,生活质量评分高于对照组。结论:健康教育联合中药泡足有助于改善下肢血管功能和生活质量。%Objective: To investigate the influence of the TCM medicine foot bath plus health education for lower extremity vascular function and quality of life in patients with diabetic foot. Methods: From June 2013 to August 2014, 60 cases of diabetic foot in our hospital were randomly divided into two groups. The observed group was given the TCM medicine foot bath plus health education; and the control group was given conventional nursing. Lower extremity vascular function and quality of life in two groups were compared. Results: IMT and PSV in the observed group were lower; and the quality of life score was higher. Conclusion: The TCM medicine foot bath plus health education on lower extremity vascular function and quality of life in patients with diabetic foot shows a significant effect.

  19. Evaluating Effects of Localized Habitat Manipulations on Landscape-level Dynamics of White-footed Mouse Populations

    Science.gov (United States)

    Due to complex population dynamics and migration behaviors, the well-being of animal populations that host human diseases sometimes varies across landscapes in ways that cannot be deduced from geographic abundance patterns alone. In such cases, efficient management of ecological...

  20. The Dynamics of Semigroups of Transcendental Meromorphic Functions

    Institute of Scientific and Technical Information of China (English)

    黄志刚

    2004-01-01

    This paper considers the dynamics associated with an arbitrary semigroup of transcendental meromorphic functions.Fatou-Julia theory was used to investigate the dynamics of these semigroups.Some results of the dynamics of a rational mapping on the Riemann sphere were extended to the case.

  1. Analysis of the epidemiological dynamics during the 1982-1983 epidemic of foot-and-mouth disease in Denmark based on molecular high-resolution strain identification

    DEFF Research Database (Denmark)

    Christensen, Laurids Siig; Normann, Preben; Thykier-Nielsen, Søren

    2005-01-01

    An epidemic of foot-and-mouth disease (FMD) causing a total of 23 cases in 1982-1983, primarily on the island of Funen, Denmark, was subjected to molecular epidemiological investigations. In an attempt to exploit the quasi-species nature of foot-and-mouth disease virus strains for molecular high...

  2. Time evolution of the autocorrelation function in dynamical replica theory

    Science.gov (United States)

    Sakata, A.

    2013-04-01

    Asynchronous dynamics given by the master equation in the Sherrington-Kirkpatrick (SK) spin-glass model is studied based on dynamical replica theory (DRT) with an extension to take into account the autocorrelation function. The dynamical behaviour of the system is approximately described by dynamical equations of the macroscopic quantities: magnetization, energy contributed by randomness and the autocorrelation function. The dynamical equations under the replica symmetry assumption are derived by introducing the subshell equipartitioning assumption and exploiting the replica method. The obtained dynamical equations are compared with Monte Carlo simulations, and it is demonstrated that the proposed formula describes well the time evolution of the autocorrelation function in some parameter regions. The study offers a reasonable description of the autocorrelation function in the SK spin-glass system.

  3. Functional evolutions for homogeneous stationary death-immigration spatial dynamics

    CERN Document Server

    Finkelshtein, Dmitri

    2011-01-01

    We discover death-immigration non-equilibrium stochastic dynamics in the continuum also known as the Surgailis process. Explicit expression for the correlation functions is presented. Dynamics of states and their generating functionals are studied. Ergodic properties for the evolutions are considered.

  4. Diabetes and Foot Problems

    Science.gov (United States)

    ... Charcot’s foot . Charcot’s foot may start with redness, warmth, and swelling. Later, bones in your feet and ... is safe) or your elbow to test the warmth of the water. Do not soak your feet ...

  5. Adult Foot Health

    Science.gov (United States)

    ... foot will usually respond to treatment with anti-fungal powders and lotions along with good foot hygiene. ... strikes thousands of Americans. This special type of arthritis can be diagnosed only by medical examination and ...

  6. Automatically Discovering Relaxed Lyapunov Functions for Polynomial Dynamical Systems

    CERN Document Server

    Liu, Jiang; Zhao, Hengjun

    2011-01-01

    The notion of Lyapunov function plays a key role in design and verification of dynamical systems, as well as hybrid and cyber-physical systems. In this paper, to analyze the asymptotic stability of a dynamical system, we generalize standard Lyapunov functions to relaxed Lyapunov functions (RLFs), by considering higher order Lie derivatives of certain functions along the system's vector field. Furthermore, we present a complete method to automatically discovering polynomial RLFs for polynomial dynamical systems (PDSs). Our method is complete in the sense that it is able to discover all polynomial RLFs by enumerating all polynomial templates for any PDS.

  7. Molecular cloning, sequence analysis, prokaryotic expression, and function prediction of foot-specific peroxidase in Hydra magnipapillata Chinese strain.

    Science.gov (United States)

    Pan, H C; Yang, H Q; Zhao, F X; Qian, X C

    2014-08-28

    The cDNA sequence of foot-specific peroxidase PPOD1 from the Chinese strain of Hydra magnipapillata was cloned by reverse transcription-polymerase chain reaction. The cDNA sequence contained a coding region with an 873-bp open reading frame, a 31-bp 5'-untranslated region, and a 36-bp 3'-untranslated region. The structure prediction results showed that PPOD1 contains 10.34% of α-helix, 38.62% of extended strand, 12.41% of β-turn, and 38.62% of random coil. The structural core was α-helix at the N terminus. The GenBank protein blast server showed that PPOD1 contains 2 fascin-like domains. In addition, high-level PPOD1 activity was only present in the ectodermal epithelial cells located on the edge of the adhesive face of the basal disc, and that these cells extended lamellipodia and filopodia when the basal disc was tightly attached to a glass slide. The fascin-like domains of Hydra PPOD1 might contribute to the bundling of the actin filament of these cells, and hence, the formation of filopodia. In conclusion, these cells might play an important role in strengthening the adsorbability of the basal disc to substrates.

  8. Seasonal modeling of hand, foot, and mouth disease as a function of meteorological variations in Chongqing, China

    Science.gov (United States)

    Wang, Pin; Zhao, Han; You, Fangxin; Zhou, Hailong; Goggins, William B.

    2017-08-01

    Hand, foot, and mouth disease (HFMD) is an enterovirus-induced infectious disease, mainly affecting children under 5 years old. Outbreaks of HFMD in recent years indicate the disease interacts with both the weather and season. This study aimed to investigate the seasonal association between HFMD and weather variation in Chongqing, China. Generalized additive models and distributed lag non-linear models based on a maximum lag of 14 days, with negative binomial distribution assumed to account for overdispersion, were constructed to model the association between reporting HFMD cases from 2009 to 2014 and daily mean temperature, relative humidity, total rainfall and sun duration, adjusting for trend, season, and day of the week. The year-round temperature and relative humidity, rainfall in summer, and sun duration in winter were all significantly associated with HFMD. An inverted-U relationship was found between mean temperature and HFMD above 19 °C in summer, with a maximum morbidity at 27 °C, while the risk increased linearly with the temperature in winter. A hockey-stick association was found for relative humidity in summer with increasing risks over 60%. Heavy rainfall, relative to no rain, was found to be associated with reduced HFMD risk in summer and 2 h of sunshine could decrease the risk by 21% in winter. The present study showed meteorological variables were differentially associated with HFMD incidence in two seasons. Short-term weather variation surveillance and forecasting could be employed as an early indicator for potential HFMD outbreaks.

  9. Immediate effects of a controllable knee ankle foot orthosis for functional compensation of gait in patients with proximal leg weakness.

    Science.gov (United States)

    Moreno, Juan C; Brunetti, Fernando; Rocon, Eduardo; Pons, José L

    2008-01-01

    Application of intermittent control of the knee joint stiffness in a knee ankle foot orthosis (KAFO) during gait is proposed. The approach combines inertial sensors and an actuator system in order to apply compensation in quadriceps weakness with a wearable device. Two methods, segment-angular rotation based and segment-angular velocity based, are analysed for the control of the knee joint state (intermittent stiffness) based on the inertial sensors signals. Protocolled tests are developed with two post-polio syndrome patients (PPS). In this study, the cases of gait with free-swinging leg and safe stance with the orthotic system are presented in terms of quantified kinematics (average peak angle of knee flexion of 50 degrees ) and evidences of reduction of frequent compensations (e.g. leg lateral movement) in post-polio syndrome patients. The results from immediate inspection indicate an important improvement of the gait patterns in two patients with proximal leg weakness by means of compensations applied by the wearable orthosis.

  10. Prevention of foot blisters.

    Science.gov (United States)

    Knapik, Joseph J

    2014-01-01

    Foot blisters are the most common medical problem faced by Soldiers during foot march operations and, if untreated, they can lead to infection. Foot blisters are caused by boots rubbing on the foot (frictional forces), which separates skin layers and allows fluid to seep in. Blisters can be prevented by wearing properly sized boots, conditioning feet through regular road marching, wearing socks that reduce reduce friction and moisture, and possibly applying antiperspirants to the feet.

  11. Dynamics and function of compact nucleosome arrays.

    Science.gov (United States)

    Poirier, Michael G; Oh, Eugene; Tims, Hannah S; Widom, Jonathan

    2009-09-01

    The packaging of eukaryotic DNA into chromatin sterically occludes polymerases, recombinases and repair enzymes. How chromatin structure changes to allow their actions is unknown. We constructed defined fluorescently labeled trinucleosome arrays, allowing analysis of chromatin conformational dynamics via fluorescence resonance energy transfer (FRET). The arrays undergo reversible Mg2+-dependent folding similar to that of longer arrays studied previously. We define two intermediate conformational states in the reversible folding of the nucleosome arrays and characterize the microscopic rate constants. Nucleosome arrays are highly dynamic even when compact, undergoing conformational fluctuations on timescales in the second to microsecond range. Compact states of the arrays allow binding to DNA within the central nucleosome via site exposure. Protein binding can also drive decompaction of the arrays. Thus, our results reveal multiple modes by which spontaneous chromatin fiber dynamics allow for the invasion and action of DNA-processing protein complexes.

  12. Semigroups of transcendental entire functions and their dynamics

    Indian Academy of Sciences (India)

    DINESH KUMAR; SANJAY KUMAR

    2017-04-01

    We investigate the dynamics of semigroups of transcendental entire functions using Fatou–Julia theory. Several results of the dynamics associated with iteration of a transcendental entire function have been extended to transcendental semigroups. We provide some condition for connectivity of the Julia set of the transcendental semigroups. We also study finitely generated transcendental semigroups, abelian transcendental semigroups and limit functions of transcendental semigroups on its invariant Fatou components.

  13. Foot Problems

    Science.gov (United States)

    ... such as getting out of a chair or climbing stairs. You may also have trouble with your balance, and your chance of falling increases. Pain that leads to less mobility can result in weight gain, weakness, and decreased heart function. But just ...

  14. Dynamic analysis with a fractional-order chaotic system for estimation of peripheral arterial disease in diabetic foot

    Science.gov (United States)

    Li, Chien-Ming; Du, Yi-Chun; Wu, Jian-Xing; Lin, Chia-Hung; Ho, Yueh-Ren; Chen, Tainsong

    2013-08-01

    Lower-extremity peripheral arterial disease (PAD) is caused by narrowing or occlusion of vessels in patients like type 2 diabetes mellitus, the elderly and smokers. Patients with PAD are mostly asymptomatic; typical early symptoms of this limb-threatening disorder are intermittent claudication and leg pain, suggesting the necessity for accurate diagnosis by invasive angiography and ankle-brachial pressure index. This index acts as a gold standard reference for PAD diagnosis and categorizes its severity into normal, low-grade and high-grade, with respective cut-off points of ≥0.9, 0.9-0.5 and diabetics and 11 healthy adults, with analysis of dynamic errors based on various butterfly motion patterns, and color relational analysis as classifier for pattern recognition. The results show that the classification of PAD severity among these testees was achieved with high accuracy and efficiency. This noninvasive methodology potentially provides timing and accessible feedback to patients with asymptomatic PAD and their physicians for further invasive diagnosis or strict management of risk factors to intervene in the disease progression.

  15. Dynamic critical phenomena from spectral functions on the lattice

    CERN Document Server

    Berges, J; Sexty, D

    2009-01-01

    We investigate spectral functions in the vicinity of the critical temperature of a second-order phase transition. Since critical phenomena in quantum field theories are governed by classical dynamics, universal properties can be computed using real-time lattice simulations. For the example of a relativistic single-component scalar field theory in 2+1 dimensions, we compute the spectral function described by universal scaling functions and extract the dynamic critical exponent z. Together with exactly known static properties of this theory, we obtain a verification from first principles that the relativistic theory is well described by the dynamic universality class of relaxational models with conserved density (Model C).

  16. Footwear and foot care knowledge as risk factors for foot problems in Indian diabetics.

    Science.gov (United States)

    Chandalia, H B; Singh, D; Kapoor, V; Chandalia, S H; Lamba, P S

    2008-10-01

    We assessed 300 diabetic and 100 age- and sex-matched controls for correlating foot wear practices and foot care knowledge and the presence of foot complications. A structured questionnaire evaluated the knowledge about foot care, type of footwear used, education level, association of tobacco abuse, and any associated symptoms of foot disease. Clinical evaluation was done by inspection of feet for presence of any external deformities, assessment of sensory function (vibration perception threshold, VPT), vascular status (foot pulses and ankle brachial ratio) and presence of any infection.In the diabetes category, 44.7% patients had not received previous foot care education. 0.6% walked barefoot outdoors and 45% walked barefoot indoors. Fourteen (4.7%) patients gave history of foot ulceration in the past and comprised the high risk group; only 2 out of 14 had received foot care education, 6 gave history of tobacco abuse, 8 had symptoms of claudication, 9 had paresthesias, 2 walked barefoot indoors. Average duration of diabetes in the high-risk and low-risk diabetes group was 10.85 +/- 6.53 and 9.83 +/- 7.99 years, respectively. In the high- and low-risk diabetic groups, VPT was 19.57 +/- 11.26 and 15.20 +/- 10.21V (P practices were important risk factors for foot problems in diabetes.

  17. Functional connectivity change as shared signal dynamics

    Science.gov (United States)

    Cole, Michael W.; Yang, Genevieve J.; Murray, John D.; Repovš, Grega; Anticevic, Alan

    2015-01-01

    Background An increasing number of neuroscientific studies gain insights by focusing on differences in functional connectivity – between groups, individuals, temporal windows, or task conditions. We found using simulations that additional insights into such differences can be gained by forgoing variance normalization, a procedure used by most functional connectivity measures. Simulations indicated that these functional connectivity measures are sensitive to increases in independent fluctuations (unshared signal) in time series, consistently reducing functional connectivity estimates (e.g., correlations) even though such changes are unrelated to corresponding fluctuations (shared signal) between those time series. This is inconsistent with the common notion of functional connectivity as the amount of inter-region interaction. New Method Simulations revealed that a version of correlation without variance normalization – covariance – was able to isolate differences in shared signal, increasing interpretability of observed functional connectivity change. Simulations also revealed cases problematic for non-normalized methods, leading to a “covariance conjunction” method combining the benefits of both normalized and non-normalized approaches. Results We found that covariance and covariance conjunction methods can detect functional connectivity changes across a variety of tasks and rest in both clinical and non-clinical functional MRI datasets. Comparison with Existing Method(s) We verified using a variety of tasks and rest in both clinical and non-clinical functional MRI datasets that it matters in practice whether correlation, covariance, or covariance conjunction methods are used. Conclusions These results demonstrate the practical and theoretical utility of isolating changes in shared signal, improving the ability to interpret observed functional connectivity change. PMID:26642966

  18. Reconstructing the origin and transmission dynamics of the 1967-68 foot-and-mouth disease epidemic in the United Kingdom.

    Science.gov (United States)

    Wright, Caroline F; Knowles, Nick J; Di Nardo, Antonello; Paton, David J; Haydon, Daniel T; King, Donald P

    2013-12-01

    A large epidemic of foot-and-mouth disease (FMD) occurred in the United Kingdom (UK) over a seven month period in Northwest England from late 1967 to the summer of 1968. This was preceded by a number of smaller FMD outbreaks in the country, two in 1967, in Hampshire and Warwickshire and one in Northumberland during 1966. The causative agent of all four events was identified as FMD virus (FMDV) serotype O and the source of the large epidemic was attributed to infected bone marrow in lamb products imported from Argentina. However, the diagnostic tools available at the time were unable to entirely rule out connections with the earlier UK FMD outbreaks, as well as other potential sources from Europe. The aim of this study was to apply molecular sequencing to investigate the likely source of this epidemic using VP1 region and full genome (FG) sequences determined directly from clinical epithelium samples (n=13) or cell culture isolates (n=6), from this and contemporary outbreaks in the UK, Europe and South America. Analysis of the VP1 sequences provided evidence for at least three separate incursions of FMDV into the UK including one independent introduction that was responsible for the main 1967/68 epidemic. Analysis of FG sequences from the main 1967/68 outbreak (n=10) revealed nucleotide substitutions at 94 genomic sites providing evidence for the linear accumulation of nucleotide substitutions (rate=2.42 × 10(-)(5)nt substitutions/site/day). However, there were five samples where this linear relationship was absent, indicating evolutional dormancy of the virus, presumably outside a host. These results help define the evolutionary dynamics of FMDV during an epidemic and contribute to the knowledge and understanding from which to base future outbreak control strategies.

  19. Habitual physical activity, peripheral neuropathy, foot deformities ...

    African Journals Online (AJOL)

    Function Scale, and a self-designed foot deformity audit form. .... categorised under: Work activity – assesses physical activity level .... married and more than half (59%) were in paid employment. ..... walking patterns of the diabetic groups.

  20. Efficient foot motor control by Neymar's brain.

    Science.gov (United States)

    Naito, Eiichi; Hirose, Satoshi

    2014-01-01

    How very long-term (over many years) motor skill training shapes internal motor representation remains poorly understood. We provide valuable evidence that the football brain of Neymar da Silva Santos Júnior (the Brasilian footballer) recruits very limited neural resources in the motor-cortical foot regions during foot movements. We scanned his brain activity with a 3-tesla functional magnetic resonance imaging (fMRI) while he rotated his right ankle at 1 Hz. We also scanned brain activity when three other age-controlled professional footballers, two top-athlete swimmers and one amateur footballer performed the identical task. A comparison was made between Neymar's brain activity with that obtained from the others. We found activations in the left medial-wall foot motor regions during the foot movements consistently across all participants. However, the size and intensity of medial-wall activity was smaller in the four professional footballers than in the three other participants, despite no difference in amount of foot movement. Surprisingly, the reduced recruitment of medial-wall foot motor regions became apparent in Neymar. His medial-wall activity was smallest among all participants with absolutely no difference in amount of foot movement. Neymar may efficiently control given foot movements probably by largely conserving motor-cortical neural resources. We discuss this possibility in terms of over-years motor skill training effect, use-dependent plasticity, and efficient motor control.

  1. Effect of Foot-and-Mouth Disease Virus Infection on the Frequency, Phenotype and Function of Circulating Dendritic Cells in Cattle.

    Science.gov (United States)

    Sei, Janet J; Waters, Ryan A; Kenney, Mary; Barlow, John W; Golde, William T

    2016-01-01

    Foot-and-mouth disease virus (FMDV) is a highly contagious virus that causes one of the most devastating diseases in cloven-hoofed animals. Disease symptoms develop within 2 to 3 days of exposure and include fever and vesicular lesions on the tongue and hooves. Dendritic cells (DC) play an essential role in protective immune responses against pathogens. Therefore, investigating their role during FMDV infection would lead to a better understanding of host-pathogen interactions. In this study, following infection of cattle with FMDV, we investigated the frequency and function of conventional (cDC) and plasmacytoid DC (pDC) in blood by using multi-color flow cytometry. We show that the frequency of cDC and pDC increased following FMDV infection and peaked 3 to 4 days post-infection. During peak viremia, the cattle became lymphopenic, the expression of MHC class II molecules on cDC and pDC was dramatically down-regulated, the processing of exogenous antigen by cDC and pDC was impaired, and there was an increase in IL-10 production by DC and monocytes. Notably, after clearance of FMDV from the blood, MHC class II expression returned to pre-infection levels. Altogether, our study demonstrates that in cattle, FMDV inhibits the function of DC, thereby retarding the initiation of adaptive immune responses, potentially enhancing virus shedding during the acute phase of infection.

  2. Analysis of Uncertainty in Dynamic Processes Development of Banks Functioning

    Directory of Open Access Journals (Sweden)

    Aleksei V. Korovyakovskii

    2013-01-01

    Full Text Available The paper offers the approach to measure of uncertainty estimation in dynamic processes of banks functioning, using statistic data of different banking operations indicators. To calculate measure of uncertainty in dynamic processes of banks functioning the phase images of relevant sets of statistic data are considered. Besides, it is shown that the form of phase image of the studied sets of statistic data can act as a basis of measure of uncertainty estimation in dynamic processes of banks functioning. The set of analytical characteristics are offered to formalize the form of phase image definition of the studied sets of statistic data. It is shown that the offered analytical characteristics consider inequality of changes in values of the studied sets of statistic data, which is one of the ways of uncertainty display in dynamic processes development. The invariant estimates of measure of uncertainty in dynamic processes of banks functioning, considering significant changes in absolute values of the same indicators for different banks were obtained. The examples of calculation of measure of uncertainty in dynamic processes of concrete banks functioning were cited.

  3. Dynamic reorganization of intrinsic functional networks in the mouse brain.

    Science.gov (United States)

    Grandjean, Joanes; Preti, Maria Giulia; Bolton, Thomas A W; Buerge, Michaela; Seifritz, Erich; Pryce, Christopher R; Van De Ville, Dimitri; Rudin, Markus

    2017-03-14

    Functional connectivity (FC) derived from resting-state functional magnetic resonance imaging (rs-fMRI) allows for the integrative study of neuronal processes at a macroscopic level. The majority of studies to date have assumed stationary interactions between brain regions, without considering the dynamic aspects of network organization. Only recently has the latter received increased attention, predominantly in human studies. Applying dynamic FC (dFC) analysis to mice is attractive given the relative simplicity of the mouse brain and the possibility to explore mechanisms underlying network dynamics using pharmacological, environmental or genetic interventions. Therefore, we have evaluated the feasibility and research potential of mouse dFC using the interventions of social stress or anesthesia duration as two case-study examples. By combining a sliding-window correlation approach with dictionary learning, several dynamic functional states (dFS) with a complex organization were identified, exhibiting highly dynamic inter- and intra-modular interactions. Each dFS displayed a high degree of reproducibility upon changes in analytical parameters and across datasets. They fluctuated at different degrees as a function of anesthetic depth, and were sensitive indicators of pathology as shown for the chronic psychosocial stress mouse model of depression. Dynamic functional states are proposed to make a major contribution to information integration and processing in the healthy and diseased brain.

  4. Paraboloid Shell As Footing

    OpenAIRE

    Al Ansari, Mohammed S.

    1999-01-01

    A simplified method for the design of paraboloid shell footing base on the displacement of the shell's crown where the column axial load is transferred to the footing has been developed. A case study was presented to demonstrate the use of the proposed method and to illustrate its capabilities. The results of the proposed method confirm the ability of the shell model in determining accurate and practical results for the design of paraboloid shell footing. Base on the analytical results of thi...

  5. Dynamic requirements for a functional protein hinge.

    Science.gov (United States)

    Kempf, James G; Jung, Ju-Yeon; Ragain, Christina; Sampson, Nicole S; Loria, J Patrick

    2007-04-20

    The enzyme triosephosphate isomerase (TIM) is a model of catalytic efficiency. The 11 residue loop 6 at the TIM active site plays a major role in this enzymatic prowess. The loop moves between open and closed states, which facilitate substrate access and catalysis, respectively. The N and C-terminal hinges of loop 6 control this motion. Here, we detail flexibility requirements for hinges in a comparative solution NMR study of wild-type (WT) TIM and a quintuple mutant (PGG/GGG). The latter contained glycine substitutions in the N-terminal hinge at Val167 and Trp168, which follow the essential Pro166, and in the C-terminal hinge at Lys174, Thr175, and Ala176. Previous work demonstrated that PGG/GGG has a tenfold higher Km value and 10(3)-fold reduced k(cat) relative to WT with either d-glyceraldehyde 3-phosphate or dihyrdroxyacetone phosphate as substrate. Our NMR results explain this in terms of altered loop-6 dynamics in PGG/GGG. In the mutant, loop 6 exhibits conformational heterogeneity with corresponding motional rates hinge design in proteins: structural rigidity is essential for focused motional freedom of active-site loops.

  6. A functional comparison of conventional knee-ankle-foot orthoses and a microprocessor-controlled leg orthosis system based on biomechanical parameters.

    Science.gov (United States)

    Schmalz, Thomas; Pröbsting, Eva; Auberger, Roland; Siewert, Gordon

    2016-04-01

    The microprocessor-controlled leg orthosis C-Brace enables patients with paretic or paralysed lower limb muscles to use dampened knee flexion under weight-bearing and speed-adapted control of the swing phase. The objective of the present study was to investigate the new technical functions of the C-Brace orthosis, based on biomechanical parameters. The study enrolled six patients. The C-Brace orthosis is compared with conventional leg orthoses (four stance control orthoses, two locked knee-ankle-foot orthoses) using biomechanical parameters of level walking, descending ramps and descending stairs. Ground reaction forces, joint moments and kinematic parameters were measured for level walking as well as ascending and descending ramps and stairs. With the C-Brace, a nearly natural stance phase knee flexion was measured during level walking (mean value 11° ± 5.6°). The maximum swing phase knee flexion angle of the C-Brace approached the normal value of 65° more closely than the stance control orthoses (66° ± 8.5° vs 74° ± 6.4°). No significant differences in the joint moments were found between the C-Brace and stance control orthosis conditions. In contrast to the conventional orthoses, all patients were able to ambulate ramps and stairs using a step-over-step technique with C-Brace (flexion angle 64.6° ± 8.2° and 70.5° ± 12.4°). The results show that the functions of the C-Brace for situation-dependent knee flexion under weight bearing have been used by patients with a high level of confidence. The functional benefits of the C-Brace in comparison with the conventional orthotic mechanisms could be demonstrated most clearly for descending ramps and stairs. The C-Brace orthosis is able to combine improved orthotic function with sustained orthotic safety. © The International Society for Prosthetics and Orthotics 2014.

  7. Measurement of dynamic efficiency: a directional distance function parametric approach

    NARCIS (Netherlands)

    Serra, T.; Oude Lansink, A.G.J.M.; Stefanou, S.E.

    2011-01-01

    This research proposes a parametric estimation of the structural dynamic efficiency measures proposed by Silva and Oude Lansink (2009). Overall, technical and allocative efficiency measurements are derived based on a directional distance function and the duality between this function and the optimal

  8. [Overuse injury syndromes of the calf and foot] ].

    Science.gov (United States)

    Smerdelj, M; Madjarević, M; Oremus, K

    2001-12-01

    The lower leg, foot and ankle form a functional unit of the locomotor system with an important static and dynamic function. Injury or loss of function of any muscle group of the lower leg and the foot influences normal gait or impedes standing. Increased or frequent loads on the muscle group may lead to pain syndromes known as overuse syndromes or overuse injuries. Athletes and certain professions involving standing or walking for a long time are especially susceptible to increased muscle strains. This article describes and clarifies the causes and the development of the pain syndromes in the lower leg, foot and ankle associated with certain professions or sports. The description of anatomical relationships and functions of individual muscle groups is here to clarify the occurrence of overuse injuries which may involve the muscle itself, the tendon, or the point of their attachment to the bone. The article describes observations and experiences from everyday clinical practice, but it also summarises results described in recent publications. The focus is also put on the therapy, which is usually conservative. Particular mention is given to new non-invasive surgical techniques. The article describes the most common overuse injuries of the lower leg such as shin splints, tibialis posterior syndrome, chronic anterior compartment syndrome, overuse injury of the Achilles tendon, enthesitis of the tendo Achilles, retrocalcanear bursitis and rupture of the Achilles tendon. In the foot area the most frequent overuse syndromes are the plantar fasciitis, tibialis posterior tendinitis, tendinitis of the long flexor of the toe, toe extensor tendinitis, and also anterior and posterior impingement syndromes of the ankle.

  9. Integrative analysis of miRNA and mRNA paired expression profiling of primary fibroblast derived from diabetic foot ulcers reveals multiple impaired cellular functions.

    Science.gov (United States)

    Liang, Liang; Stone, Rivka C; Stojadinovic, Olivera; Ramirez, Horacio; Pastar, Irena; Maione, Anna G; Smith, Avi; Yanez, Vanessa; Veves, Aristides; Kirsner, Robert S; Garlick, Jonathan A; Tomic-Canic, Marjana

    2016-11-01

    Diabetic foot ulcers (DFUs) are one of the major complications of diabetes. Its molecular pathology remains poorly understood, impeding the development of effective treatments. Although it has been established that multiple cell types, including fibroblasts, keratinocytes, macrophages, and endothelial cells, all contribute to inhibition of healing, less is known regarding contributions of individual cell type. Thus, we generated primary fibroblasts from nonhealing DFUs and evaluated their cellular and molecular properties in comparison to nondiabetic foot fibroblasts (NFFs). Specifically, we analyzed both micro-RNA and mRNA expression profiles of primary DFU fibroblasts. Paired genomic analyses identified a total of 331 reciprocal miRNA-mRNA pairs including 21 miRNAs (FC > 2.0) along with 239 predicted target genes (FC > 1.5) that are significantly and differentially expressed. Of these, we focused on three miRNAs (miR-21-5p, miR-34a-5p, miR-145-5p) that were induced in DFU fibroblasts as most differentially regulated. The involvement of these microRNAs in wound healing was investigated by testing the expression of their downstream targets as well as by quantifying cellular behaviors in prospectively collected and generated cell lines from 15 patients (seven DFUF and eight NFF samples). We found large number of downstream targets of miR-21-5p, miR-34a-5p, miR-145-5p to be coordinately regulated in mRNA profiles, which was confirmed by quantitative real-time PCR. Pathway analysis on paired miRNA-mRNA profiles predicted inhibition of cell movement and cell proliferation, as well as activation of cell differentiation and senescence in DFU fibroblasts, which was confirmed by cellular assays. We concluded that induction of miR-21-5p, miR-34a-5p, miR-145-5p in DFU dermal fibroblasts plays an important role in impairing multiple cellular functions, thus contributing to overall inhibition of healing in DFUs.

  10. A Novel Prosthetic Foot Designed to Maximize Functional Abilities, Health Outcomes and Quality of Life in People with Transtibial Amputation

    Science.gov (United States)

    2016-09-01

    expenditure, endurance, functional ability, patient-centered health outcomes, quality of life, randomized crossover trial 16. SECURITY CLASSIFICATION OF: 17...study protocol (01-09-2015) is included below: o Modification 3 (local IRB approval 15-08-2015): Added collection of social security number (SSN) to... Neuro -Qol Applied Cognition General Concerns instruments to initial testing. Instruments were added to inform results of self-report and performance

  11. Intrinsically disordered proteins: structural and functional dynamics

    Directory of Open Access Journals (Sweden)

    Wallin S

    2017-02-01

    Full Text Available Stefan Wallin Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St. John’s, NL, Canada Abstract: The classical view holds that proteins fold into essentially unique three-dimensional structures before becoming biologically active. However, studies over the last several years have provided broad and convincing evidence that some proteins do not adopt a single structure and yet are fully functional. These intrinsically disordered proteins (IDPs have been found to be highly prevalent in many genomes, including human, and play key roles in central cellular processes, such as regulation of transcription and translation, cell cycle, and cell signaling. Moreover, IDPs are overrepresented among proteins implicated in disease, including various cancers and neurodegenerative disorders. Intense efforts, by using both experimental and computational approaches, are consequently under way to uncover the molecular mechanisms that underpin the roles of IDPs in biology and disease. This review provides an introduction to the general biophysical properties of IDPs and discusses some of the recent emerging areas in IDP research, including the roles of IDPs in allosteric regulation, regulatory unfolding, and formation of intracellular membrane-less organelles. In addition, recent attempts at therapeutic targeting of IDPs by small molecules, noting in particular that IDPs represent a potentially important source of new drug targets in light of their central role in protein–protein interaction networks, are also reviewed. Keywords: natively unfolded proteins, unstructured proteins, protein folding, protein–protein interaction, cell regulation, signaling, drug development, inhibitors

  12. Effect of foot load changes on foot arch evaluation using foot pressure distribution data

    National Research Council Canada - National Science Library

    Kazuya Imaizumi; Yumi Iwakami; Kazuhiko Yamashita

    2014-01-01

    ... be helpful in health support for the elderly. The present authors have developed a classification system for foot arch type showing high reliability using foot pressure distribution data [1-2]. However, effect of foot load changes on foot arch evaluation remains unclear. The aim of this study was to investigate the effect of foot load chan...

  13. Foot bone kinematics as measured in a cadaveric robotic gait simulator.

    Science.gov (United States)

    Whittaker, Eric C; Aubin, Patrick M; Ledoux, William R

    2011-04-01

    The bony motion of the foot during the stance phase of gait is useful to further our understanding of joint function, disease etiology, injury prevention and surgical intervention. In this study, we used a 10-segment in vitro foot model with anatomical coordinate systems and a robotic gait simulator (RGS) to measure the kinematics of the tibia, talus, calcaneus, cuboid, navicular, medial cuneiform, first metatarsal, hallux, third metatarsal, and fifth metatarsal from six cadaveric feet. The RGS accurately reproduced in vivo vertical ground reaction force (5.9% body weight RMS error) and tibia to ground kinematics. The kinematic data from the foot model generally agree with invasive in vivo descriptions of bony motion and provides the most realistic description of bony motion currently available for an in vitro model. These data help to clarify the function of several joints that are difficult to study in vivo; for example, the combined range of motion of the talonavicular, naviculocuneiform, metatarsocuneiform joints provided more sagittal plane mobility (27.4°) than the talotibial joint alone (23.2°). Additionally, the anatomical coordinate systems made it easier to meaningfully determine bone-to-bone motion, describing uniplanar motion as rotation about a single axis rather than about three. The data provided in this study allow for many kinematic interpretations to be made about dynamic foot bone motion, and the methodology presents a means to explore many invasive foot biomechanics questions under near-physiologic conditions.

  14. Abstraction of Continuous Dynamical Systems Utilizing Lyapunov Functions

    DEFF Research Database (Denmark)

    Sloth, Christoffer; Wisniewski, Rafal

    2010-01-01

    This paper considers the development of a method for abstracting continuous dynamical systems by timed automata. The method is based on partitioning the state space of dynamical systems with invariant sets, which form cells representing locations of the timed automata. To enable verification...... of the dynamical system based on the abstraction, conditions for obtaining sound, complete, and refinable abstractions are set up. It is proposed to partition the state space utilizing sub-level sets of Lyapunov functions, since they are positive invariant sets. The existence of sound abstractions for Morse......-Smale systems and complete and refinable abstractions for linear systems are shown....

  15. Diabetic foot infections.

    Science.gov (United States)

    Gemechu, Fassil W; Seemant, Fnu; Curley, Catherine A

    2013-08-01

    Diabetic foot infection, defined as soft tissue or bone infection below the malleoli, is the most common complication of diabetes mellitus leading to hospitalization and the most frequent cause of nontraumatic lower extremity amputation. Diabetic foot infections are diagnosed clinically based on the presence of at least two classic findings of inflammation or purulence. Infections are classified as mild, moderate, or severe. Most diabetic foot infections are polymicrobial. The most common pathogens are aerobic gram-positive cocci, mainly Staphylococcus species. Osteomyelitis is a serious complication of diabetic foot infection that increases the likelihood of surgical intervention. Treatment is based on the extent and severity of the infection and comorbid conditions. Mild infections are treated with oral antibiotics, wound care, and pressure off-loading in the outpatient setting. Selected patients with moderate infections and all patients with severe infections should be hospitalized, given intravenous antibiotics, and evaluated for possible surgical intervention. Peripheral arterial disease is present in up to 40% of patients with diabetic foot infections, making evaluation of the vascular supply critical. All patients with diabetes should undergo a systematic foot examination at least once a year, and more frequently if risk factors for diabetic foot ulcers exist. Preventive measures include patient education on proper foot care, glycemic and blood pressure control, smoking cessation, use of prescription footwear, intensive care from a podiatrist, and evaluation for surgical interventions as indicated.

  16. The dynamic transfer function for a cavitating inducer

    Science.gov (United States)

    Brennen, C.; Acosta, A. J.

    1975-01-01

    Knowledge of the dynamic performance of pumps is essential for the prediction of transient behavior and instabilities in hydraulic systems; the necessary information is in the form of a transfer function which relates the instantaneous or fluctuating pressure and mass flow rate at inlet to the same quantities in the discharge from the pump. The presence of cavitation within the pump can have a major effect on this transfer function since dynamical changes in the volume of cavitation contribute to the difference in the instantaneous inlet and discharge mass flow rates. The present paper utilizes results from free streamline cascade theory to evaluate the elements in the transfer function for a cavitating inducer and shows that the numerical results are consistent with the characteristics observed in some dynamic tests on rocket engine turbopumps.

  17. An information theory framework for dynamic functional domain connectivity.

    Science.gov (United States)

    Vergara, Victor M; Miller, Robyn; Calhoun, Vince

    2017-06-01

    Dynamic functional network connectivity (dFNC) analyzes time evolution of coherent activity in the brain. In this technique dynamic changes are considered for the whole brain. This paper proposes an information theory framework to measure information flowing among subsets of functional networks call functional domains. Our method aims at estimating bits of information contained and shared among domains. The succession of dynamic functional states is estimated at the domain level. Information quantity is based on the probabilities of observing each dynamic state. Mutual information measurement is then obtained from probabilities across domains. Thus, we named this value the cross domain mutual information (CDMI). Strong CDMIs were observed in relation to the subcortical domain. Domains related to sensorial input, motor control and cerebellum form another CDMI cluster. Information flow among other domains was seldom found. Other methods of dynamic connectivity focus on whole brain dFNC matrices. In the current framework, information theory is applied to states estimated from pairs of multi-network functional domains. In this context, we apply information theory to measure information flow across functional domains. Identified CDMI clusters point to known information pathways in the basal ganglia and also among areas of sensorial input, patterns found in static functional connectivity. In contrast, CDMI across brain areas of higher level cognitive processing follow a different pattern that indicates scarce information sharing. These findings show that employing information theory to formally measured information flow through brain domains reveals additional features of functional connectivity. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Crystallization induced by multiple seeds: dynamical density functional approach.

    Science.gov (United States)

    Neuhaus, T; Schmiedeberg, M; Löwen, H

    2013-12-01

    Using microscopic dynamical density functional theory, we calculate the dynamical formation of polycrystals by following the crystal growth around multiple crystalline seeds imposed to an undercooled fluid. Depending on the undercooling and the size ratio as well as the relative crystal orientation of two neighboring seeds, three possibilities of the final state emerge, namely no crystallization at all, formation of a monocrystal, or two crystallites separated by a curved grain boundary. Our results, which are obtained for two-dimensional hard disk systems using a fundamental-measure density functional, shed new light on the particle-resolved structure and growth of polycrystalline material in general.

  19. A foot drop correcting FES envelope design method using tibialis anterior EMG during healthy gait with a new walking speed control strategy.

    Science.gov (United States)

    Chen, M; Wang, Q B; Lou, X X; Xu, K; Zheng, X X

    2010-01-01

    Restoring walking functions will greatly improve the foot-drop patients' life quality. In this work, we sampled 10 healthy subjects' gait data when walking in 4 different stride frequency overground and developed a dynamic Functional Electrical Stimulation (dFES) system for foot-drop patients' walk training, using the processed tibialis anterior (TA) muscle EMG signal. The data sampled under the new strategy can be used by FES system directly. And the dFES system can provide dynamic Pulse Width Modulation (PWM) FES serial according to the healthy subjects' TA EMG intensity features.

  20. Quantitative evaluation of the reticuloendothelial system function with dynamic MRI.

    Directory of Open Access Journals (Sweden)

    Ting Liu

    Full Text Available PURPOSE: To evaluate the reticuloendothelial system (RES function by real-time imaging blood clearance as well as hepatic uptake of superparamagnetic iron oxide nanoparticle (SPIO using dynamic magnetic resonance imaging (MRI with two-compartment pharmacokinetic modeling. MATERIALS AND METHODS: Kinetics of blood clearance and hepatic accumulation were recorded in young adult male 01b74 athymic nude mice by dynamic T2* weighted MRI after the injection of different doses of SPIO nanoparticles (0.5, 3 or 10 mg Fe/kg. Association parameter, Kin, dissociation parameter, Kout, and elimination constant, Ke, derived from dynamic data with two-compartment model, were used to describe active binding to Kupffer cells and extrahepatic clearance. The clodrosome and liposome were utilized to deplete macrophages and block the RES function to evaluate the capability of the kinetic parameters for investigation of macrophage function and density. RESULTS: The two-compartment model provided a good description for all data and showed a low sum squared residual for all mice (0.27±0.03. A lower Kin, a lower Kout and a lower Ke were found after clodrosome treatment, whereas a lower Kin, a higher Kout and a lower Ke were observed after liposome treatment in comparison to saline treatment (P<0.005. CONCLUSION: Dynamic SPIO-enhanced MR imaging with two-compartment modeling can provide information on RES function on both a cell number and receptor function level.

  1. Ab initio molecular dynamics using hybrid density functionals

    Science.gov (United States)

    Guidon, Manuel; Schiffmann, Florian; Hutter, Jürg; Vandevondele, Joost

    2008-06-01

    Ab initio molecular dynamics simulations with hybrid density functionals have so far found little application due to their computational cost. In this work, an implementation of the Hartree-Fock exchange is presented that is specifically targeted at ab initio molecular dynamics simulations of medium sized systems. We demonstrate that our implementation, which is available as part of the CP2K/Quickstep program, is robust and efficient. Several prescreening techniques lead to a linear scaling cost for integral evaluation and storage. Integral compression techniques allow for in-core calculations on systems containing several thousand basis functions. The massively parallel implementation respects integral symmetry and scales up to hundreds of CPUs using a dynamic load balancing scheme. A time-reversible multiple time step scheme, exploiting the difference in computational efficiency between hybrid and local functionals, brings further time savings. With extensive simulations of liquid water, we demonstrate the ability to perform, for several tens of picoseconds, ab initio molecular dynamics based on hybrid functionals of systems in the condensed phase containing a few thousand Gaussian basis functions.

  2. Development of a transfer function method for dynamic stability measurement

    Science.gov (United States)

    Johnson, W.

    1977-01-01

    Flutter testing method based on transfer function measurements is developed. The error statistics of several dynamic stability measurement methods are reviewed. It is shown that the transfer function measurement controls the error level by averaging the data and correlating the input and output. The method also gives a direct estimate of the error in the response measurement. An algorithm is developed for obtaining the natural frequency and damping ratio of low damped modes of the system, using integrals of the transfer function in the vicinity of a resonant peak. Guidelines are given for selecting the parameters in the transfer function measurement. Finally, the dynamic stability measurement technique is applied to data from a wind tunnel test of a proprotor and wing model.

  3. Habitual functional electrical stimulation therapy improves gait kinematics and walking performance, but not patient-reported functional outcomes, of people with multiple sclerosis who present with foot-drop.

    Directory of Open Access Journals (Sweden)

    Marietta L van der Linden

    Full Text Available BACKGROUND: People with Multiple Sclerosis (pwMS often experience a disturbed gait function such as foot-drop. The objective of this pilot study was to investigate the medium term effects of using Functional Electrical Stimulation (FES to treat foot-drop over a period 12 weeks on gait and patient reported outcomes of pwMS. METHODS AND FINDINGS: Nine pwMS aged 35 to 64 (2 males, 7 females were assessed on four occasions; four weeks before baseline, at baseline and after six weeks and twelve weeks of FES use. Joint kinematics and performance on the 10 meter and 2 minute walk tests (10WT, 2 minWT were assessed with and without FES. Participants also completed the MS walking Scale (MSWS, MS impact scale (MSIS29, Fatigue Severity Score (FSS and wore an activity monitor for seven days after each assessment. Compared to unassisted walking, FES resulted in statistically significant improvements in peak dorsiflexion in swing (p = 0.006, 10MWT (p = 0.006 and 2 minWT (p = 0.002. Effect sizes for the training effect, defined as the change from unassisted walking at baseline to that at 12 weeks, indicated improved ankle angle at initial contact (2.6°, 95% CI -1° to 4°, d = 0.78, and a decrease in perceived exertion over the 2 min walking tests (-1.2 points, 95% CI -5.7 to 3.4, d = -0.86. Five participants exceeded the Minimally Detectable Change (MDC for a training effect on the 10mWT, but only two did so for the 2 minWT. No effects of the use of FES for 12 weeks were found for MSWS, MSIS29, FSS or step count. CONCLUSION: Although FES to treat foot-drop appears to offer the potential for a medium term training effect on ankle kinematics and walking speed, this was not reflected in the patient reported outcomes. This observed lack of relationship between objective walking performance and patient reported outcomes warrants further investigation. TRIAL REGISTRATION: ClinicalTrials.gov NCT01977287.

  4. Dynamics Model Abstraction Scheme Using Radial Basis Functions

    Directory of Open Access Journals (Sweden)

    Silvia Tolu

    2012-01-01

    Full Text Available This paper presents a control model for object manipulation. Properties of objects and environmental conditions influence the motor control and learning. System dynamics depend on an unobserved external context, for example, work load of a robot manipulator. The dynamics of a robot arm change as it manipulates objects with different physical properties, for example, the mass, shape, or mass distribution. We address active sensing strategies to acquire object dynamical models with a radial basis function neural network (RBF. Experiments are done using a real robot’s arm, and trajectory data are gathered during various trials manipulating different objects. Biped robots do not have high force joint servos and the control system hardly compensates all the inertia variation of the adjacent joints and disturbance torque on dynamic gait control. In order to achieve smoother control and lead to more reliable sensorimotor complexes, we evaluate and compare a sparse velocity-driven versus a dense position-driven control scheme.

  5. Light-Front Dynamics and the 3He Spectral Function

    CERN Document Server

    Pace, Emanuele; Kaptari, Leonid; Rinaldi, Matteo; Salme', Giovanni; Scopetta, Sergio

    2016-01-01

    Two topics are presented. The first one is a novel approach for a Poincare' covariant description of nuclear dynamics based on light-front Hamiltonian dynamics. The key quantity is the light-front spectral function, where both normalization and momentum sum rule can be satisfied at the same time. Preliminary results are discussed for an initial analysis of the role of relativity in the EMC effect in 3He. A second issue, very challenging, is considered in a non-relativistic framework, namely a distorted spin-dependent spectral function for 3He in order to take care of the final state interaction between the observed pion and the remnant in semi-inclusive deep inelastic electron scattering off polarized 3He. The generalization of the analysis within the light-front dynamics is outlined.

  6. Population dynamics and mutualism: Functional responses of benefits and costs

    Science.gov (United States)

    Holland, J. Nathaniel; DeAngelis, Donald L.; Bronstein, Judith L.

    2002-01-01

    We develop an approach for studying population dynamics resulting from mutualism by employing functional responses based on density‐dependent benefits and costs. These functional responses express how the population growth rate of a mutualist is modified by the density of its partner. We present several possible dependencies of gross benefits and costs, and hence net effects, to a mutualist as functions of the density of its partner. Net effects to mutualists are likely a monotonically saturating or unimodal function of the density of their partner. We show that fundamental differences in the growth, limitation, and dynamics of a population can occur when net effects to that population change linearly, unimodally, or in a saturating fashion. We use the mutualism between senita cactus and its pollinating seed‐eating moth as an example to show the influence of different benefit and cost functional responses on population dynamics and stability of mutualisms. We investigated two mechanisms that may alter this mutualism's functional responses: distribution of eggs among flowers and fruit abortion. Differences in how benefits and costs vary with density can alter the stability of this mutualism. In particular, fruit abortion may allow for a stable equilibrium where none could otherwise exist.

  7. From dynamics to structure and function of model biomolecular systems

    NARCIS (Netherlands)

    Fontaine-Vive-Curtaz, F.

    2007-01-01

    The purpose of this thesis was to extend recent works on structure and dynamics of hydrogen bonded crystals to model biomolecular systems and biological processes. The tools that we have used are neutron scattering (NS) and density functional theory (DFT) and force field (FF) based simulation method

  8. Nonadiabatic dynamics with intersystem crossings: A time-dependent density functional theory implementation

    Energy Technology Data Exchange (ETDEWEB)

    Franco de Carvalho, F. [Centre Européen de Calcul Atomique et Moléculaire, Ecole Polytechnique Fédérale de Lausanne, Lausanne (Switzerland); Tavernelli, I. [IBM Research GmbH, Zurich Research Laboratory, 8803 Ruschlikon (Switzerland)

    2015-12-14

    In this work, we derive a method to perform trajectory-based nonadiabatic dynamics that is able to describe both nonadiabatic transitions and intersystem crossing events (transitions between states of different spin-multiplicity) at the same level of theory, namely, time-dependent density functional theory (TDDFT). To this end, we combined our previously developed TDDFT-based trajectory surface hopping scheme with an accurate and efficient algorithm for the calculation of the spin-orbit coupling (SOC) matrix elements. More specifically, we designed two algorithms for the calculation of intersystem crossing transitions, one based on an extended Tully’s surface hopping scheme including SOC and the second based on a Landau-Zener approximation applied to the spin sector of the electronic Hilbert space. This development allows for the design of an efficient on-the-fly nonadiabatic approach that can handle, on an equal footing, nonadiabatic and intersystem crossing transitions. The method is applied to the study of the photophysics of sulfur dioxide (SO{sub 2}) in gas and liquid phases.

  9. Q-angle in patellofemoral pain: relationship with dynamic knee valgus, hip abductor torque, pain and function

    Directory of Open Access Journals (Sweden)

    Gabriel Peixoto Leão Almeida

    2016-04-01

    Full Text Available OBJECTIVE: To investigate the relationship between the q-angle and anterior knee pain severity, functional capacity, dynamic knee valgus and hip abductor torque in women with patellofemoral pain syndrome (PFPS. METHODS: This study included 22 women with PFPS. The q-angle was assessed using goniometry: the participants were positioned in dorsal decubitus with the knee and hip extended, and the hip and foot in neutral rotation. Anterior knee pain severity was assessed using a visual analog scale, and functional capacity was assessed using the anterior knee pain scale. Dynamic valgus was evaluated using the frontal plane projection angle (FPPA of the knee, which was recorded using a digital camera during step down, and hip abductor peak torque was recorded using a handheld dynamometer. RESULTS: The q-angle did not present any significant correlation with severity of knee pain (r = -0.29; p = 0.19, functional capacity (r = -0.08; p = 0.72, FPPA (r = -0.28; p = 0.19 or isometric peak torque of the abductor muscles (r = -0.21; p = 0.35. CONCLUSION: The q-angle did not present any relationship with pain intensity, functional capacity, FPPA, or hip abductor peak torque in the patients with PFPS.

  10. Quantum Dynamics in Classical Time Evolution of Correlation Functions

    CERN Document Server

    Wetterich, C

    1997-01-01

    The time-dependence of correlation functions under the influence of cla= ssical equations of motion is described by an exact evolution equation. For conservative systems thermodynamic equilibrium is a fixed point of these equations. We show that this fixed point is not universally stable, since infinitely many conserved correlation functions obstruct the approach to equilibrium. Equilibrium can therefore be reached at most for suitably av= eraged quantities or for subsystems, similar to quantum statistics. The classica= l time evolution of correlation functions shows many dynamical features of quant= um mechanics.

  11. Comparison Criteria for Nonlinear Functional Dynamic Equations of Higher Order

    Directory of Open Access Journals (Sweden)

    Taher S. Hassan

    2016-01-01

    Full Text Available We will consider the higher order functional dynamic equations with mixed nonlinearities of the form xnt+∑j=0Npjtϕγjxφjt=0, on an above-unbounded time scale T, where n≥2, xi(t≔ri(tϕαixi-1Δ(t,  i=1,…,n-1,   with  x0=x,  ϕβ(u≔uβsgn⁡u, and α[i,j]≔αi⋯αj. The function φi:T→T is a rd-continuous function such that limt→∞φi(t=∞ for j=0,1,…,N. The results extend and improve some known results in the literature on higher order nonlinear dynamic equations.

  12. Dynamical density functional theory with hydrodynamic interactions in confined geometries

    Science.gov (United States)

    Goddard, B. D.; Nold, A.; Kalliadasis, S.

    2016-12-01

    We study the dynamics of colloidal fluids in both unconfined geometries and when confined by a hard wall. Under minimal assumptions, we derive a dynamical density functional theory (DDFT) which includes hydrodynamic interactions (HI; bath-mediated forces). By using an efficient numerical scheme based on pseudospectral methods for integro-differential equations, we demonstrate its excellent agreement with the full underlying Langevin equations for systems of hard disks in partial confinement. We further use the derived DDFT formalism to elucidate the crucial effects of HI in confined systems.

  13. 单侧功能性踝关节不稳者的单足静态平衡能力%The single foot static balancing ability of people suffering from single side functional ankle joint instability

    Institute of Scientific and Technical Information of China (English)

    张阳; 张秋霞; 金超

    2014-01-01

    In order to probe into the characteristics of the single foot static balancing ability of people suffering from single side functional ankle joint instability, the authors used a WIN-POD balancing instrument to test the static balancing ability of 15 people suffering from single side functional ankle joint instability and 15 normal people in eyes opened and shut single foot standing conditions for 10, and revealed the following findings: 1) in an eyes opened left foot standing condition, the differences in envelop area and axisY shaking amplitude between the people in the experiment group and the people in the control group were statistically significant (P<0.05); in an eyes shut standing condition, except axesX andY shaking speeds, the differences in other indexes between the people in the experiment group and people in the control group were statistically significant (P<0.05); 2) in an eyes shut right foot standing condition, the differences in envelop area and axisY shaking amplitude between the people in the experi-ment group and the people in the control group were statistically significant (P<0.05); 3) for the people in the ex-periment group, in an eyes opened standing condition, the difference in envelop area between the ill foot and the healthy one was statistically significant (P<0.05), in an eyes shut standing condition, the differences in envelop area and average axisY shaking amplitude between the ill foot and the healthy one were statistically significant (P<0.05); 4) for the people in the control group, in an eyes shut standing condition, except axesX andY shaking speeds, the differences in other indexes between the left foot and the right one were all statistically significant (P<0.05). The said findings indicate the followings: for people suffering from single side functional ankle joint instability, the bal-ancing ability of the ill foot is slightly weaker than that of the corresponding foot of normal people, and also weaker than that of the

  14. Ankle-foot orthoses in stroke: effects on functional balance, weight-bearing asymmetry and the contribution of each lower limb to balance control.

    NARCIS (Netherlands)

    Simons, C.D.; Asseldonk, E.H. van; Kooij, H. van der; Geurts, A.C.H.; Buurke, J.

    2009-01-01

    BACKGROUND: Ankle-foot orthoses are often provided to improve walking in stroke patients, although the evidence of effects on walking and balance control is still inconsistent. This could be caused by a lack of insight into the influence of orthoses on the underlying impairments. These impairments c

  15. Ankle-foot orthoses in stroke: Effects on functional balance, weight-bearing asymmetry and the contribution of each lower limb to balance control

    NARCIS (Netherlands)

    Simons, Corien D.M.; Asseldonk, van Edwin H.F.; Kooij, van der Herman; Geurts, Alexander C.H.; Buurke, Jaap H.

    2009-01-01

    Background Ankle-foot orthoses are often provided to improve walking in stroke patients, although the evidence of effects on walking and balance control is still inconsistent. This could be caused by a lack of insight into the influence of orthoses on the underlying impairments. These impairments ca

  16. A Conserved Domain in the Leader Proteinase of Foot-and-Mouth Disease Virus is Required for Proper Sub-Cellular Localization and Function

    Science.gov (United States)

    The leader proteinase (Lpro) of foot-and-mouth disease virus (FMDV) is involved in antagonizing the innate immune response by blocking the expression of interferon (IFN) protein and by reducing the immediate-early induction of IFN beta mRNA and IFN stimulated genes. In addition to its role in shutti...

  17. [Minor foot amputations in diabetic foot syndrome].

    Science.gov (United States)

    Biehl, C; Eckhard, M; Szalay, G; Heiss, C

    2016-10-01

    The treatment strategy for diabetic foot syndrome must take into account protective sensibility of the foot, open wounds, infection status, and the rules of septic bone surgery. Interventions are classified as elective, prophylactic, curative, or emergency. Amputations in the forefoot and midfoot region are performed as ray amputations (including metatarsal), which can often be carried out as "inner" amputations. Gentle tissue treatment mandatory because of greater risk of revision with re-amputation compared to classical amputation. Good demarcation of infection, acute osteomyelitis, osteolytic lesions, neurotropic ulcer, arterial and venous blood flow to the other toes, gangrene of other toes with metatarsal affection. Arterial occlusive disease, infection of neighboring areas, avoidable amputations, poorly healing ulcers on the lower leg. Primary dorsal approach; minimal incisional distance (5 cm) to minimize skin necrosis risk. Atraumatic preparation, minimize hemostasis to not compromise the borderline perfusion situation. In amputations, plantar skin preparation and longer seams placed as dorsal as possible, either disarticulated and maintain cartilage, or round the cortical metatarsal bone after resection. Diabetes control. Braun splint, mobilization in a shoe with forefoot decompression and hindfoot support, physiotherapy. Antibiotics based on resistance testing. If no complications, dressing change on postoperative day 1. Optimal wound drainage by lowering foot several times a day; drainage removal after 12-24 h. Insoles and footwear optimization. Amputations require continued attention and if necessary treatment to avoid sequelae. Insufficient treatment associated with recurrent ulceration and altered anatomy.

  18. Education for diabetic foot

    Directory of Open Access Journals (Sweden)

    Fabio Batista

    2009-03-01

    Full Text Available Objective: The purpose of this investigation was to stratify the risk in a consecutive group of diabetic patients presenting, for the first time, in a diabetic foot clinic. Additional aims were to investigate the preventive measures in the local health system and to evaluate the level of patient’s awareness about diabetic foot-associated morbidity. Methods: Fifty consecutive adult diabetic patients referred to a Diabetic Foot Clinic of a Municipal Public Hospital comprised the sample for this observational study. The enrollment visit was considered as the first health-system intervention for potential foot morbidity. The average time elapsed since a diagnosis of diabetes among patients was five years. Rresults: At the time of presentation, 94% of sample was not using appropriate footwear. Pedal pulses (dorsalis pedis and/or posterior tibial arteries were palpable in 76% of patients. Thirty subjects (60% had signs of peripheral neuropathy. Twenty-one subjects (42% had clinical deformity. There was a positive correlation between a history of foot ulcer, the presence of peripheral neuropathy, and the presence of foot deformity (p < 0.004 in each correlation. Cconclusions: Informing and educating the patients and those interested in this subject and these problems is essential for favorable outcomes in this scenario.

  19. Crossing the entropy barrier of dynamical zeta functions

    Energy Technology Data Exchange (ETDEWEB)

    Aurich, R.; Bolte, J.; Matthies, C.; Sieber, M.; Steiner, F. (Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik)

    1992-01-01

    Dynamical zeta functions are an important tool to quantize chaotic dynamical systems. The basic quantization rules require the computation of the zeta functions on the real energy axis, where the Euler product representations running over the classical periodic orbits usually do not converge due to the existence of the so-called entropy barrier determined by the topological entropy of the classical system. We shown that the convergence properties of the dynamical zeta functions rewritten as Dirichlet series are governed not only by the well-known topological and metric entropy, but depend crucially on subtle statistical properties of the Maslow indices and of the multiplicities of the periodic orbits that are measured by a new parameter for which we introduce the notion of a third entropy. If and only if the third entropy is nonvanishing, one can cross the entropy barrier; if it exceeds a certain value, one can even compute the zeta function in the physical region by means of a convergent Dirichlet series. A simple statistical model is presented which allows to compute the third entropy. Four examples of chaotic systems are studied in detail to test the model numerically. (orig.).

  20. Enzymes: An integrated view of structure, dynamics and function

    Directory of Open Access Journals (Sweden)

    Agarwal Pratul K

    2006-01-01

    Full Text Available Abstract Microbes utilize enzymes to perform a variety of functions. Enzymes are biocatalysts working as highly efficient machines at the molecular level. In the past, enzymes have been viewed as static entities and their function has been explained on the basis of direct structural interactions between the enzyme and the substrate. A variety of experimental and computational techniques, however, continue to reveal that proteins are dynamically active machines, with various parts exhibiting internal motions at a wide range of time-scales. Increasing evidence also indicates that these internal protein motions play a role in promoting protein function such as enzyme catalysis. Moreover, the thermodynamical fluctuations of the solvent, surrounding the protein, have an impact on internal protein motions and, therefore, on enzyme function. In this review, we describe recent biochemical and theoretical investigations of internal protein dynamics linked to enzyme catalysis. In the enzyme cyclophilin A, investigations have lead to the discovery of a network of protein vibrations promoting catalysis. Cyclophilin A catalyzes peptidyl-prolyl cis/trans isomerization in a variety of peptide and protein substrates. Recent studies of cyclophilin A are discussed in detail and other enzymes (dihydrofolate reductase and liver alcohol dehydrogenase where similar discoveries have been reported are also briefly discussed. The detailed characterization of the discovered networks indicates that protein dynamics plays a role in rate-enhancement achieved by enzymes. An integrated view of enzyme structure, dynamics and function have wide implications in understanding allosteric and co-operative effects, as well as protein engineering of more efficient enzymes and novel drug design.

  1. Anatomical and functional properties of the foot and leg representation in areas 3b, 1 and 2 of primary somatosensory cortex in humans: A 7T fMRI study.

    Science.gov (United States)

    Akselrod, Michel; Martuzzi, Roberto; Serino, Andrea; van der Zwaag, Wietske; Gassert, Roger; Blanke, Olaf

    2017-06-17

    Primary somatosensory cortex (S1) processes somatosensory information and is composed of multiple subregions. In particular, tactile information from the skin is encoded in three subregions, namely Brodmann areas (BAs) 3b, 1 and 2, with each area representing a complete map of the contralateral body. Although, much is known about the somatotopic organization of the hand in human S1, less research has been carried out regarding the somatotopic maps of the foot and leg in S1. Moreover, a latero-medial S1 organization along the superior part of the postcentral gyrus has been reported when moving from hip to toes, yet to date there is no study investigating leg/foot maps within the different subregions of S1. Using ultra-high field MRI (7T), we mapped six cortical representations of the lower limb (hip to toes) at the single subject level and performed this analysis separately for BAs 3b, 1 and 2. Analyzing the BOLD responses associated with tactile stimulations of the mapped foot and leg regions on each side, we quantified the extent and the strength of activation to determine somatotopic organization. In addition, we investigated whether each mapped representation also responded to the stimulation of other body parts (i.e. response selectivity) and conducted dissimilarity analysis relating these anatomical and functional properties of S1 to the physical structure of the lower limbs. Our data reveal somatotopy for the leg, but not for the foot in all investigated BAs, with large inter-subject variability. We found only minor differences between the properties of the three investigated BAs, suggesting that S1 maps for the lower limbs differ from those described for the hand. We also describe greater extent/strength of S1 activation for the big toe representation (compared to the other mapped representations) within all BAs, suggesting a possible homology between the first digit of upper and lower extremity in humans, and report different patterns of selectivity in the

  2. Foot posture is associated with kinematics of the foot during gait: A comparison of normal, planus and cavus feet.

    Science.gov (United States)

    Buldt, Andrew K; Levinger, Pazit; Murley, George S; Menz, Hylton B; Nester, Christopher J; Landorf, Karl B

    2015-06-01

    Variations in foot posture are associated with the development of some lower limb injuries. However, the mechanisms underlying this relationship are unclear. The objective of this study was to compare foot kinematics between normal, pes cavus and pes planus foot posture groups using a multi-segment foot model. Ninety-seven healthy adults, aged 18-47 were classified as either normal (n=37), pes cavus (n=30) or pes planus (n=30) based on normative data for the Foot Posture Index, Arch Index and normalised navicular height. A five segment foot model was used to measure tri-planar motion of the rearfoot, midfoot, medial forefoot, lateral forefoot and hallux during barefoot walking at a self-selected speed. Angle at heel contact, peak angle, time to peak angle and range of motion was measured for each segment. One way ANOVAs with post-hoc analyses of mean differences were used to compare foot posture groups. The pes cavus group demonstrated a distinctive pattern of motion compared to the normal and pes planus foot posture groups. Effect sizes of significant mean differences were large and comparable to similar studies. Three key differences in overall foot function were observed between the groups: (i) altered frontal and transverse plane angles of the rearfoot in the pes cavus foot; (ii) Less midfoot motion in the pes cavus foot during initial contact and midstance; and (iii) reduced midfoot frontal plane ROM in the pes planus foot during pre-swing. These findings indicate that foot posture does influence motion of the foot.

  3. Dynamic density functional theory of solid tumor growth: Preliminary models

    Directory of Open Access Journals (Sweden)

    Arnaud Chauviere

    2012-03-01

    Full Text Available Cancer is a disease that can be seen as a complex system whose dynamics and growth result from nonlinear processes coupled across wide ranges of spatio-temporal scales. The current mathematical modeling literature addresses issues at various scales but the development of theoretical methodologies capable of bridging gaps across scales needs further study. We present a new theoretical framework based on Dynamic Density Functional Theory (DDFT extended, for the first time, to the dynamics of living tissues by accounting for cell density correlations, different cell types, phenotypes and cell birth/death processes, in order to provide a biophysically consistent description of processes across the scales. We present an application of this approach to tumor growth.

  4. A Bayesian Algorithm for Functional Mapping of Dynamic Complex Traits

    Directory of Open Access Journals (Sweden)

    Rongling Wu

    2009-04-01

    Full Text Available Functional mapping of dynamic traits measured in a longitudinal study was originally derived within the maximum likelihood (ML context and implemented with the EM algorithm. Although ML-based functional mapping possesses many favorable statistical properties in parameter estimation, it may be computationally intractable for analyzing longitudinal data with high dimensions and high measurement errors. In this article, we derive a general functional mapping framework for quantitative trait locus mapping of dynamic traits within the Bayesian paradigm. Markov chain Monte Carlo techniques were implemented for functional mapping to estimate biologically and statistically sensible parameters that model the structures of time-dependent genetic effects and covariance matrix. The Bayesian approach is useful to handle difficulties in constructing confidence intervals as well as the identifiability problem, enhancing the statistical inference of functional mapping. We have undertaken simulation studies to investigate the statistical behavior of Bayesian-based functional mapping and used a real example with F2 mice to validate the utilization and usefulness of the model.

  5. Spatiotemporal dynamics of re-innervation and hyperinnervation patterns by uninjured CGRP fibers in the rat foot sole epidermis after nerve injury.

    Science.gov (United States)

    Duraku, Liron S; Hossaini, Mehdi; Hoendervangers, Sieske; Falke, Lukas L; Kambiz, Shoista; Mudera, Vivek C; Holstege, Joan C; Walbeehm, Erik T; Ruigrok, Tom J H

    2012-08-30

    The epidermis is innervated by fine nerve endings that are important in mediating nociceptive stimuli. However, their precise role in neuropathic pain is still controversial. Here, we have studied the role of epidermal peptidergic nociceptive fibers that are located adjacent to injured fibers in a rat model of neuropathic pain. Using the Spared Nerve Injury (SNI) model, which involves complete transections of the tibial and common peroneal nerve while sparing the sural and saphenous branches, mechanical hypersensitivity was induced of the uninjured lateral (sural) and medial (saphenous) area of the foot sole. At different time points, a complete foot sole biopsy was taken from the injured paw and processed for Calcitonin Gene-Related Peptide (CGRP) immunohistochemistry. Subsequently, a novel 2D-reconstruction model depicting the density of CGRP fibers was made to evaluate the course of denervation and re-innervation by uninjured CGRP fibers. The results show an increased density of uninjured CGRP-IR epidermal fibers on the lateral and medial side after a SNI procedure at 5 and 10 weeks. Furthermore, although in control animals the density of epidermal CGRP-IR fibers in the footpads was lower compared to the surrounding skin of the foot, 10 weeks after the SNI procedure, the initially denervated footpads displayed a hyper-innervation. These data support the idea that uninjured fibers may play a considerable role in development and maintenance of neuropathic pain and that it is important to take larger biopsies to test the relationship between innervation of injured and uninjured nerve areas.

  6. Spatiotemporal dynamics of re-innervation and hyperinnervation patterns by uninjured CGRP fibers in the rat foot sole epidermis after nerve injury

    Directory of Open Access Journals (Sweden)

    Duraku Liron S

    2012-08-01

    Full Text Available Abstract The epidermis is innervated by fine nerve endings that are important in mediating nociceptive stimuli. However, their precise role in neuropathic pain is still controversial. Here, we have studied the role of epidermal peptidergic nociceptive fibers that are located adjacent to injured fibers in a rat model of neuropathic pain. Using the Spared Nerve Injury (SNI model, which involves complete transections of the tibial and common peroneal nerve while sparing the sural and saphenous branches, mechanical hypersensitivity was induced of the uninjured lateral (sural and medial (saphenous area of the foot sole. At different time points, a complete foot sole biopsy was taken from the injured paw and processed for Calcitonin Gene-Related Peptide (CGRP immunohistochemistry. Subsequently, a novel 2D-reconstruction model depicting the density of CGRP fibers was made to evaluate the course of denervation and re-innervation by uninjured CGRP fibers. The results show an increased density of uninjured CGRP-IR epidermal fibers on the lateral and medial side after a SNI procedure at 5 and 10 weeks. Furthermore, although in control animals the density of epidermal CGRP-IR fibers in the footpads was lower compared to the surrounding skin of the foot, 10 weeks after the SNI procedure, the initially denervated footpads displayed a hyper-innervation. These data support the idea that uninjured fibers may play a considerable role in development and maintenance of neuropathic pain and that it is important to take larger biopsies to test the relationship between innervation of injured and uninjured nerve areas.

  7. Dynamic Behavior of Axially Functionally Graded Pipes Conveying Fluid

    Directory of Open Access Journals (Sweden)

    Chen An

    2017-01-01

    Full Text Available Dynamic behavior of axially functionally graded (FG pipes conveying fluid was investigated numerically by using the generalized integral transform technique (GITT. The transverse vibration equation was integral transformed into a coupled system of second-order differential equations in the temporal variable. The Mathematica’s built-in function, NDSolve, was employed to numerically solve the resulting transformed ODE system. Excellent convergence of the proposed eigenfunction expansions was demonstrated for calculating the transverse displacement at various points of axially FG pipes conveying fluid. The proposed approach was verified by comparing the obtained results with the available solutions reported in the literature. Moreover, parametric studies were performed to analyze the effects of Young’s modulus variation, material distribution, and flow velocity on the dynamic behavior of axially FG pipes conveying fluid.

  8. Dynamic Regulation and Function of Histone Monoubiquitination in Plants

    Directory of Open Access Journals (Sweden)

    Jing eFeng

    2014-03-01

    Full Text Available Polyubiquitin chain deposition on a target protein frequently leads to proteasome-mediated degradation whereas monoubiquitination modifies target protein property and function independent of proteolysis. Histone monoubiquitination occurs in chromatin and is in nowadays recognized as one critical type of epigenetic marks in eukaryotes. While H2A monoubiquitination (H2Aub1 is generally associated with transcription repression mediated by the Polycomb pathway, H2Bub1 is involved in transcription activation. H2Aub1 and H2Bub1 levels are dynamically regulated via deposition and removal by specific enzymes. We review knows and unknowns of dynamic regulation of H2Aub1 and H2Bub1 deposition and removal in plants and highlight the underlying crucial functions in gene transcription, cell proliferation/differentiation, and plant growth and development. We also discuss crosstalks existing between H2Aub1 or H2Bub1 and different histone methylations for an ample mechanistic understanding.

  9. Unveiling protein functions through the dynamics of the interaction network.

    Directory of Open Access Journals (Sweden)

    Irene Sendiña-Nadal

    Full Text Available Protein interaction networks have become a tool to study biological processes, either for predicting molecular functions or for designing proper new drugs to regulate the main biological interactions. Furthermore, such networks are known to be organized in sub-networks of proteins contributing to the same cellular function. However, the protein function prediction is not accurate and each protein has traditionally been assigned to only one function by the network formalism. By considering the network of the physical interactions between proteins of the yeast together with a manual and single functional classification scheme, we introduce a method able to reveal important information on protein function, at both micro- and macro-scale. In particular, the inspection of the properties of oscillatory dynamics on top of the protein interaction network leads to the identification of misclassification problems in protein function assignments, as well as to unveil correct identification of protein functions. We also demonstrate that our approach can give a network representation of the meta-organization of biological processes by unraveling the interactions between different functional classes.

  10. Subdiffusive dynamics of bump attractors: mechanisms and functional roles.

    Science.gov (United States)

    Qi, Yang; Breakspear, Michael; Gong, Pulin

    2015-02-01

    Bump attractors are localized activity patterns that can self-sustain after stimulus presentation, and they are regarded as the neural substrate for a host of perceptual and cognitive processes. One of the characteristic features of bump attractors is that they are neutrally stable, so that noisy inputs cause them to drift away from their initial locations, severely impairing the accuracy of bump location-dependent neural coding. Previous modeling studies of such noise-induced drifting activity of bump attractors have focused on normal diffusive dynamics, often with an assumption that noisy inputs are uncorrelated. Here we show that long-range temporal correlations and spatial correlations in neural inputs generated by multiple interacting bumps cause them to drift in an anomalous subdiffusive way. This mechanism for generating subdiffusive dynamics of bump attractors is further analyzed based on a generalized Langevin equation. We demonstrate that subdiffusive dynamics can significantly improve the coding accuracy of bump attractors, since the variance of the bump displacement increases sublinearly over time and is much smaller than that of normal diffusion. Furthermore, we reanalyze existing psychophysical data concerning the spread of recalled cue position in spatial working memory tasks and show that its variance increases sublinearly with time, consistent with subdiffusive dynamics of bump attractors. Based on the probability density function of bump position, we also show that the subdiffusive dynamics result in a long-tailed decay of firing rate, greatly extending the duration of persistent activity.

  11. Infimal convolution of total generalized variation functionals for dynamic MRI.

    Science.gov (United States)

    Schloegl, Matthias; Holler, Martin; Schwarzl, Andreas; Bredies, Kristian; Stollberger, Rudolf

    2017-07-01

    To accelerate dynamic MR applications using infimal convolution of total generalized variation functionals (ICTGV) as spatio-temporal regularization for image reconstruction. ICTGV comprises a new image prior tailored to dynamic data that achieves regularization via optimal local balancing between spatial and temporal regularity. Here it is applied for the first time to the reconstruction of dynamic MRI data. CINE and perfusion scans were investigated to study the influence of time dependent morphology and temporal contrast changes. ICTGV regularized reconstruction from subsampled MR data is formulated as a convex optimization problem. Global solutions are obtained by employing a duality based non-smooth optimization algorithm. The reconstruction error remains on a low level with acceleration factors up to 16 for both CINE and dynamic contrast-enhanced MRI data. The GPU implementation of the algorithm suites clinical demands by reducing reconstruction times of one dataset to less than 4 min. ICTGV based dynamic magnetic resonance imaging reconstruction allows for vast undersampling and therefore enables for very high spatial and temporal resolutions, spatial coverage and reduced scan time. With the proposed distinction of model and regularization parameters it offers a new and robust method of flexible decomposition into components with different degrees of temporal regularity. Magn Reson Med 78:142-155, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  12. The dynamic mechanism of presenilin-function: Sensitive gate dynamics and loop unplugging control protein access

    DEFF Research Database (Denmark)

    Somavarapu, Arun Kumar; Kepp, Kasper Planeta

    2016-01-01

    molecular dynamics in an explicit membrane with particular account of the as yet unexplored loop dynamics. We find that mature PSEN1 contains multiple distinct conformational states whereas non-mature PSEN1 is a typical one-state protein. We confirm a previously suggested gating mechanism, and find......There is no molecular explanation for the many presenilin 1 (PSEN1) mutations causing Alzheimer's disease, but both gain of function relating to amyloid production and loss of isolated PSEN1 function have been implied. We report here the first detailed dynamic all-atom model of mature PSEN1 from...... that the 106-131 loop acts as a "hinge" for the TM2 and TM6 "doors". More importantly, we identify an unplugging mechanism of the Exon 9 loop associated only with mature PSEN1. Proper opening of both the "gate" and "plug" in the membrane produces channel-like morphologies and access to the catalytic aspartates...

  13. The 3He spectral function in light-front dynamics

    Directory of Open Access Journals (Sweden)

    Rinaldi Matteo

    2016-01-01

    Full Text Available A distorted spin-dependent spectral function for 3He is considered for the extraction of the transverse-momentum dependent parton distributions in the neutron from semi-inclusive deep inelastic electron scattering off polarized 3He at finite momentum transfers, where final state interactions are taken into account. The generalization of the analysis to a Poincaré covariant framework within the light-front dynamics is outlined.

  14. The 3He spectral function in light-front dynamics

    CERN Document Server

    Rinaldi, Matteo; Kaptari, Leonid; Pace, Emanuele; Salmè, Giovanni; Scopetta, Sergio

    2016-01-01

    A distorted spin-dependent spectral function for 3He is considered for the extraction of the transverse-momentum dependent parton distributions in the neutron from semi-inclusive deep inelastic electron scattering off polarized 3He at finite momentum transfers, where final state interactions are taken into account. The generalization of the analysis to a Poincar\\'e covariant framework within the light-front dynamics is outlined.

  15. Stratum corneum dynamic function measurements after moisturizer or irritant application.

    Science.gov (United States)

    Treffel, P; Gabard, B

    1995-01-01

    Two simple tests were conducted which allowed the quantification of parameters that characterize the stratum corneum (SC) dynamic functions in vivo under physiological conditions after moisturizer applications for 1 h and after irritation with different concentrations of sodium lauryl sulphate (SLS; 0.5-4%) applied under occlusion for 15 min or 24 h. Both tests, the sorption-desorption test (SDT) and the moisture accumulation test (MAT), were performed with a Nova Dermal Phase Meter 9003. The following parameters were quantified: prehydration state (SDT, MAT), hygroscopicity, water-holding capacity (SDT), water accumulation velocity and water accumulation (MAT). These procedures allowed the demonstration of the water-holding effect of urea contained in moisturizers. Differences between the long and the short application time of SLS were characterized by differences in SC dynamic functions while the hydration state was not changed. An effect on transepidermal water loss (TEWL) was noted only after the long application time, although the MAT clearly showed dynamic parameters to be changed after 15 min of treatment. These tests were simple in practice and allowed the demonstration of functional modifications of the SC while other parameters remained unchanged. They gave insight into possible action mechanisms of urea and SLS in the SC.

  16. Dynamic reorganization of brain functional networks during cognition.

    Science.gov (United States)

    Bola, Michał; Sabel, Bernhard A

    2015-07-01

    How does cognition emerge from neural dynamics? The dominant hypothesis states that interactions among distributed brain regions through phase synchronization give basis for cognitive processing. Such phase-synchronized networks are transient and dynamic, established on the timescale of milliseconds in order to perform specific cognitive operations. But unlike resting-state networks, the complex organization of transient cognitive networks is typically not characterized within the graph theory framework. Thus, it is not known whether cognitive processing merely changes the strength of functional connections or, conversely, requires qualitatively new topological arrangements of functional networks. To address this question, we recorded high-density EEG while subjects performed a visual discrimination task. We conducted an event-related network analysis (ERNA) where source-space weighted functional networks were characterized with graph measures. ERNA revealed rapid, transient, and frequency-specific reorganization of the network's topology during cognition. Specifically, cognitive networks were characterized by strong clustering, low modularity, and strong interactions between hub-nodes. Our findings suggest that dense and clustered connectivity between the hub nodes belonging to different modules is the "network fingerprint" of cognition. Such reorganization patterns might facilitate global integration of information and provide a substrate for a "global workspace" necessary for cognition and consciousness to occur. Thus, characterizing topology of the event-related networks opens new vistas to interpret cognitive dynamics in the broader conceptual framework of graph theory. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Dynamics of learning near singularities in radial basis function networks.

    Science.gov (United States)

    Wei, Haikun; Amari, Shun-Ichi

    2008-09-01

    The radial basis function (RBF) networks are one of the most widely used models for function approximation in the regression problem. In the learning paradigm, the best approximation is recursively or iteratively searched for based on observed data (teacher signals). One encounters difficulties in such a process when two component basis functions become identical, or when the magnitude of one component becomes null. In this case, the number of the components reduces by one, and then the reduced component recovers as the learning process proceeds further, provided such a component is necessary for the best approximation. Strange behaviors, especially the plateau phenomena, have been observed in dynamics of learning when such reduction occurs. There exist singularities in the space of parameters, and the above reduction takes place at the singular regions. This paper focuses on a detailed analysis of the dynamical behaviors of learning near the overlap and elimination singularities in RBF networks, based on the averaged learning equation that is applicable to both on-line and batch mode learning. We analyze the stability on the overlap singularity by solving the eigenvalues of the Hessian explicitly. Based on the stability analysis, we plot the analytical dynamic vector fields near the singularity, which are then compared to those real trajectories obtained by a numeric method. We also confirm the existence of the plateaus in both batch and on-line learning by simulation.

  18. Operators versus functions: from quantum dynamical semigroups to tomographic semigroups

    Science.gov (United States)

    Aniello, Paolo

    2013-11-01

    Quantum mechanics can be formulated in terms of phase-space functions, according to Wigner's approach. A generalization of this approach consists in replacing the density operators of the standard formulation with suitable functions, the so-called generalized Wigner functions or (group-covariant) tomograms, obtained by means of group-theoretical methods. A typical problem arising in this context is to express the evolution of a quantum system in terms of tomograms. In the case of a (suitable) open quantum system, the dynamics can be described by means of a quantum dynamical semigroup 'in disguise', namely, by a semigroup of operators acting on tomograms rather than on density operators. We focus on a special class of quantum dynamical semigroups, the twirling semigroups, that have interesting applications, e.g., in quantum information science. The 'disguised counterparts' of the twirling semigroups, i.e., the corresponding semigroups acting on tomograms, form a class of semigroups of operators that we call tomographic semigroups. We show that the twirling semigroups and the tomographic semigroups can be encompassed in a unique theoretical framework, a class of semigroups of operators including also the probability semigroups of classical probability theory, so achieving a deeper insight into both the mathematical and the physical aspects of the problem.

  19. Painful Lytic Lesions of the Foot : A Case Report

    Directory of Open Access Journals (Sweden)

    R Vaishya

    2015-03-01

    Full Text Available The presence of lytic lesions in the bones of foot raises a number of diagnostic possibilities ranging from infection, inflammatory pathology to neoplastic conditions. Although the radiological picture is not pathognomonic of any pathology, clinical history and histopathological examination can help to clinch the diagnosis. We present a case of multiple lytic lesions of the foot and discuss possible differential diagnoses. The patient was diagnosed as a case of madura foot and the lesions responded to surgical debridement and anti-fungal treatment with a good functional outcome. Madura foot is an uncommon, chronic granulomatous fungal or bacterial infection with a predilection in people who walk barefoot. Although known for a specific geographical distribution, madura foot should be kept as a possible diagnosis in patients presenting with lytic lesions of the foot due to population emigration across the world.

  20. Gait: the role of the ankle and foot in walking.

    Science.gov (United States)

    Dubin, Andrew

    2014-03-01

    Evaluation of gait and its associated deviations from normal requires an in-depth evaluation of the patient and an appreciation for the complexity of the task. Understanding gait starts with an appreciation of the basic determinants of gait. Foot drop is a common gait deviation. Functionally, a foot drop results in a long limb. This will result in alterations of the gait cycle during swing phase. The common compensations for a foot drop include steppage gait, circumduction, and a persistently abducted limb. Noninterventional options for management of common gait deviations secondary to ankle/foot dysfunction present challenges.

  1. Dynamics of Microbial Functional Groups in Rhizosphere of Spring Barley

    Directory of Open Access Journals (Sweden)

    Vlad Stoian

    2016-11-01

    Full Text Available Plant rhizosphere is the portion of soil which is in direct contact with the plant roots. From the microbiological point of view, this area is characterized by strong dynamic of functional groups with high specificity towards the substrate available. Spring barley is a crop with high requirements to the composition of the microflora in the rhizosphere, disturbances produced by agronomic inputs affecting the stability of rhizospheric contact interfaces and ultimately the plant growth. Analysis of changes within the microbial community was carried out with the purpose of defining the disruptive impact of mineral inputs and potential of zeolite to reduce these disruptions. Microbial functional groups were analyzed on the basis of the CO2 export under the specific conditions of soil inoculation on specific substrates over a time period of incubation. Microresp detection plates allow evaluation of a large number of samples under identical conditions of inoculation and the establishment of dynamics of the entire microbial community. The dynamics of the entire microbial communities (basal respiration is stimulated to increase in case of unilateral application of zeolite and zeolite as a buffer for urea fertilization. General growth trend of microbial communities follows proportional the associated application of zeolite with urea, the most powerful non-symbiotic nitrogen fixation processes being stimulated by this combination of fertilizers. Simultaneously, an increase in the dynamics of denitrifiers was observed, also the decomposition of lignin and cellulose and biological crust formation due to the proliferation of cyanobacteria. Rhizosphere of barley plants is characterized by the presence of actinomycetes as dominant in functional microbial community of all experimental variants analyzed with a high capacity for biological degradation and raised mineralization of organic matter.

  2. Real-time estimation of dynamic functional connectivity networks.

    Science.gov (United States)

    Monti, Ricardo Pio; Lorenz, Romy; Braga, Rodrigo M; Anagnostopoulos, Christoforos; Leech, Robert; Montana, Giovanni

    2017-01-01

    Two novel and exciting avenues of neuroscientific research involve the study of task-driven dynamic reconfigurations of functional connectivity networks and the study of functional connectivity in real-time. While the former is a well-established field within neuroscience and has received considerable attention in recent years, the latter remains in its infancy. To date, the vast majority of real-time fMRI studies have focused on a single brain region at a time. This is due in part to the many challenges faced when estimating dynamic functional connectivity networks in real-time. In this work, we propose a novel methodology with which to accurately track changes in time-varying functional connectivity networks in real-time. The proposed method is shown to perform competitively when compared to state-of-the-art offline algorithms using both synthetic as well as real-time fMRI data. The proposed method is applied to motor task data from the Human Connectome Project as well as to data obtained from a visuospatial attention task. We demonstrate that the algorithm is able to accurately estimate task-related changes in network structure in real-time. Hum Brain Mapp 38:202-220, 2017. © 2016 Wiley Periodicals, Inc.

  3. Dynamical zeta functions for piecewise monotone maps of the interval

    CERN Document Server

    Ruelle, David

    2004-01-01

    Consider a space M, a map f:M\\to M, and a function g:M \\to {\\mathbb C}. The formal power series \\zeta (z) = \\exp \\sum ^\\infty _{m=1} \\frac {z^m}{m} \\sum _{x \\in \\mathrm {Fix}\\,f^m} \\prod ^{m-1}_{k=0} g (f^kx) yields an example of a dynamical zeta function. Such functions have unexpected analytic properties and interesting relations to the theory of dynamical systems, statistical mechanics, and the spectral theory of certain operators (transfer operators). The first part of this monograph presents a general introduction to this subject. The second part is a detailed study of the zeta functions associated with piecewise monotone maps of the interval [0,1]. In particular, Ruelle gives a proof of a generalized form of the Baladi-Keller theorem relating the poles of \\zeta (z) and the eigenvalues of the transfer operator. He also proves a theorem expressing the largest eigenvalue of the transfer operator in terms of the ergodic properties of (M,f,g).

  4. Lattice dynamics and disorder-induced contraction in functionalized graphene

    Science.gov (United States)

    Feng Huang, Liang; Zeng, Zhi

    2013-02-01

    The lattice dynamics and disorder-induced contraction in hydrogenated, fluorinated, and chlorinated graphene are studied by first-principles simulation. The effects of the functionalization on the phonon dispersions, Grüneissen constants, vibrational thermodynamic functions (free energy, internal energy, entropy, and heat capacity), thermal-expansion coefficients, and bulk moduli are systematically investigated. Functionalization changes the chemical-bond length, mass, thickness, vibrational-mode symmetry, and mode number, and subsequently has significant effects on the phonon dispersions and Grüneissen constants. Functionalization generally increases the vibrational thermodynamic functions, and their temperature dependences all present conventional isotope effects. Functionalization suppresses (enhances) the thermal contraction (expansion) of the lattice, due to the increases in the system mass, membrane thickness, and the compressibility of the phonons. Both the lattice-constant variation and the phonon thermalization contribute to the temperature dependence of the bulk modulus. Both pristine and hydrogenated graphene can be viewed as two kinds of materials having the Invar and Elinvar properties. The contribution to the lattice contraction in functionalized graphene from the conformation disorder (about 2.0%) is much larger than that by thermalization (<0.1% at 300 K), which explains the mismatch between the experimental and theoretical lattice constants.

  5. Effects of foot position of the nonparetic side during sit-to-stand training on postural balance in patients with stroke.

    Science.gov (United States)

    Han, Jintae; Kim, Youngmi; Kim, Kyung

    2015-08-01

    [Purpose] We aimed to investigate postural balance after sit-to-stand (STS) training with different nonparetic foot positions in stroke patients. [Subjects] Thirty-six subjects who experienced a stroke (21 males, 15 females) participated and were divided into the symmetric foot position (SYMM), asymmetric foot position (ASYM), and step foot (STEP) groups. [Methods] Each group performed repetitive sit-to-stand training 5 times a week for 6 weeks. The timed up-and-go test (TUG), functional reach test (FRT), and F-mat system correcting the anterior/posterior (A-P) and medial/lateral (M-L) distance of the center of pressure (COP) were used to measure the static and dynamic postural balance pre- and postintervention. ANCOVA was used to analyze differences among groups, and preintervention variables were used as covariates. [Results] The TUG, FRT, and A-P and M-L distance of the COP in the ASYM and STEP groups were significantly decreased after intervention compared with the SYMM group. All parameters in the STEP group were lower than those in the ASYM group, without a significant difference. [Conclusion] The asymmetric foot position during STS is a good intervention to improve the static and dynamic postural balance in stroke patients. Especially, using a step to change the foot position is effective in improving STS performance.

  6. Charcot foot syndrome.

    Science.gov (United States)

    Jeffcoate, W J

    2015-06-01

    Charcot foot syndrome is an uncommon complication of diabetes but is potentially devastating in its consequences. Outcome is made worse by widespread professional ignorance leading to delayed diagnosis, but it is also hampered by lack of understanding of its causes and lack of treatments with proven effectiveness, other than offloading. There remains a desperate need for studies into its causes as well as comparative audit and trials designed to determine the best treatment for this difficult condition. Such work can probably only be effectively carried out through the establishment of multicentre networks. Nevertheless, improved understanding in recent years of the likely role of inflammatory pathways has raised awareness of the multiple ways in which the effects of neuropathy may be manifest in the development of the Charcot foot. This awareness is also leading to the realization that similar processes may conceivably contribute to the refractoriness of other foot diseases in diabetes, including both chronic unhealing ulcers and osteomyelitis.

  7. Foot muscles strengthener

    Directory of Open Access Journals (Sweden)

    Boris T. Glavač

    2012-04-01

    Full Text Available Previous experience in the correction of flat feet consisted of the use of insoles for shoes and exercises with toys, balls, rollers, inclined planes, etc. A device for strengthening foot muscles is designed for the correction of flat feet in children and, as its name suggests, for strengthening foot muscles in adults. The device is made of wood and metal, with a mechanism and technical solutions, enabling the implementation of specific exercises to activate muscles responsible for the formation of the foot arch. It is suitable for home use with controlled load quantities since it has calibrated springs. The device is patented with the Intellectual Property Office, Republic of Serbia, as a petty patent.

  8. Functional data analysis for dynamical system identification of behavioral processes.

    Science.gov (United States)

    Trail, Jessica B; Collins, Linda M; Rivera, Daniel E; Li, Runze; Piper, Megan E; Baker, Timothy B

    2014-06-01

    Efficient new technology has made it straightforward for behavioral scientists to collect anywhere from several dozen to several thousand dense, repeated measurements on one or more time-varying variables. These intensive longitudinal data (ILD) are ideal for examining complex change over time but present new challenges that illustrate the need for more advanced analytic methods. For example, in ILD the temporal spacing of observations may be irregular, and individuals may be sampled at different times. Also, it is important to assess both how the outcome changes over time and the variation between participants' time-varying processes to make inferences about a particular intervention's effectiveness within the population of interest. The methods presented in this article integrate 2 innovative ILD analytic techniques: functional data analysis and dynamical systems modeling. An empirical application is presented using data from a smoking cessation clinical trial. Study participants provided 42 daily assessments of pre-quit and post-quit withdrawal symptoms. Regression splines were used to approximate smooth functions of craving and negative affect and to estimate the variables' derivatives for each participant. We then modeled the dynamics of nicotine craving using standard input-output dynamical systems models. These models provide a more detailed characterization of the post-quit craving process than do traditional longitudinal models, including information regarding the type, magnitude, and speed of the response to an input. The results, in conjunction with standard engineering control theory techniques, could potentially be used by tobacco researchers to develop a more effective smoking intervention.

  9. Brownian dynamics without Green's functions

    Energy Technology Data Exchange (ETDEWEB)

    Delong, Steven; Donev, Aleksandar, E-mail: donev@courant.nyu.edu [Courant Institute of Mathematical Sciences, New York University, New York, New York 10012 (United States); Usabiaga, Florencio Balboa; Delgado-Buscalioni, Rafael [Departamento de Física Teórica de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Univeridad Autónoma de Madrid, Madrid 28049 (Spain); Griffith, Boyce E. [Courant Institute of Mathematical Sciences, New York University, New York, New York 10012 (United States); Leon H. Charney Division of Cardiology, Department of Medicine, New York University School of Medicine, New York, New York 10016 (United States)

    2014-04-07

    We develop a Fluctuating Immersed Boundary (FIB) method for performing Brownian dynamics simulations of confined particle suspensions. Unlike traditional methods which employ analytical Green's functions for Stokes flow in the confined geometry, the FIB method uses a fluctuating finite-volume Stokes solver to generate the action of the response functions “on the fly.” Importantly, we demonstrate that both the deterministic terms necessary to capture the hydrodynamic interactions among the suspended particles, as well as the stochastic terms necessary to generate the hydrodynamically correlated Brownian motion, can be generated by solving the steady Stokes equations numerically only once per time step. This is accomplished by including a stochastic contribution to the stress tensor in the fluid equations consistent with fluctuating hydrodynamics. We develop novel temporal integrators that account for the multiplicative nature of the noise in the equations of Brownian dynamics and the strong dependence of the mobility on the configuration for confined systems. Notably, we propose a random finite difference approach to approximating the stochastic drift proportional to the divergence of the configuration-dependent mobility matrix. Through comparisons with analytical and existing computational results, we numerically demonstrate the ability of the FIB method to accurately capture both the static (equilibrium) and dynamic properties of interacting particles in flow.

  10. Dynamic fracture of functionally graded magnetoelectroelastic composite materials

    Energy Technology Data Exchange (ETDEWEB)

    Stoynov, Y. [Faculty of Applied Mathematics and Informatics, Technical University of Sofia (Bulgaria); Dineva, P. [Institute of Mechanics, Bulgarian Academy of Sciences, Sofia (Bulgaria)

    2014-11-12

    The stress, magnetic and electric field analysis of multifunctional composites, weakened by impermeable cracks, is of fundamental importance for their structural integrity and reliable service performance. The aim is to study dynamic behavior of a plane of functionally graded magnetoelectroelastic composite with more than one crack. The coupled material properties vary exponentially in an arbitrary direction. The plane is subjected to anti-plane mechanical and in-plane electric and magnetic load. The boundary value problem described by the partial differential equations with variable coefficients is reduced to a non-hypersingular traction boundary integral equation based on the appropriate functional transform and frequency-dependent fundamental solution derived in a closed form by Radon transform. Software code based on the boundary integral equation method (BIEM) is developed, validated and inserted in numerical simulations. The obtained results show the sensitivity of the dynamic stress, magnetic and electric field concentration in the cracked plane to the type and characteristics of the dynamic load, to the location and cracks disposition, to the wave-crack-crack interactions and to the magnitude and direction of the material gradient.

  11. Multiscale functions, scale dynamics, and applications to partial differential equations

    Science.gov (United States)

    Cresson, Jacky; Pierret, Frédéric

    2016-05-01

    Modeling phenomena from experimental data always begins with a choice of hypothesis on the observed dynamics such as determinism, randomness, and differentiability. Depending on these choices, different behaviors can be observed. The natural question associated to the modeling problem is the following: "With a finite set of data concerning a phenomenon, can we recover its underlying nature? From this problem, we introduce in this paper the definition of multi-scale functions, scale calculus, and scale dynamics based on the time scale calculus [see Bohner, M. and Peterson, A., Dynamic Equations on Time Scales: An Introduction with Applications (Springer Science & Business Media, 2001)] which is used to introduce the notion of scale equations. These definitions will be illustrated on the multi-scale Okamoto's functions. Scale equations are analysed using scale regimes and the notion of asymptotic model for a scale equation under a particular scale regime. The introduced formalism explains why a single scale equation can produce distinct continuous models even if the equation is scale invariant. Typical examples of such equations are given by the scale Euler-Lagrange equation. We illustrate our results using the scale Newton's equation which gives rise to a non-linear diffusion equation or a non-linear Schrödinger equation as asymptotic continuous models depending on the particular fractional scale regime which is considered.

  12. [The diabetic foot].

    Science.gov (United States)

    Stirnemann, P; Z'Brun, A; Brunner, D

    1998-10-01

    Problems of the diabetic foot are frequent. The magnitude of the clinical picture and morbidity mirrors the severity and complexity of the underlying pathobiology. The three pathogenetic mechanism involved are ischemia, neuropathy and infection. Seldom do these mechanisms work in isolation, rather most foot problems result from a complex interplay among all three. The clinical picture of the diabetic foot reaches from the neuropathic deformity with diminished or absent sensation of pain to limited gangrene or superficial ulcer. The polymicrobial infection leads to extensive tissue destruction (plantarphlegmone) with osteomyelitis. The patients often notes no pain and may become aware of the infection only through the presence of drainage or a foul odor. These infections are usually more extensive than would be predicted by clinical signs and symptoms. These lesions must be debrided and drained promptly and completely. This often requires amputations of one or more toes, combined with an incision along the entire course of the infected track on the plantar or dorsal aspect of the foot. Cultures should be taken from the depth of the wound. Initial treatment should be with broad-spectrum antibiotics, with subsequent adjustment based on culture results. The diabetic foot is a clinical problem that can be solved with a high degree of success when the approached by an interdisciplinary team (specialists in infectious and vascular disease, podiatry and diabetology). Arterial reconstruction should be designed to restore maximum perfusion to the foot. The most effective result can be obtained with infra-inguinal vein bypass with distal anastomosis to the most proximal artery with direct continuity to the ischemic territory. The single most important factor in the achievement of the reduction of amputation is the autologous vein bypass. The overall outcome in the diabetic patient in terms of graft patency and limb salvage is equal to that in the nondiabetic.

  13. Hash function construction using weighted complex dynamical networks

    Institute of Scientific and Technical Information of China (English)

    Song Yu-Rong; Jiang Guo-Ping

    2013-01-01

    A novel scheme to construct a hash function based on a weighted complex dynamical network (WCDN) generated from an original message is proposed in this paper.First,the original message is divided into blocks.Then,each block is divided into components,and the nodes and weighted edges are well defined from these components and their relations.Namely,the WCDN closely related to the original message is established.Furthermore,the node dynamics of the WCDN are chosen as a chaotic map.After chaotic iterations,quantization and exclusive-or operations,the fixed-length hash value is obtained.This scheme has the property that any tiny change in message can be diffused rapidly through the WCDN,leading to very different hash values.Analysis and simulation show that the scheme possesses good statistical properties,excellent confusion and diffusion,strong collision resistance and high efficiency.

  14. Capacidade funcional dos pacientes com diabetes mellitus e pé ulcerado Capacidad funcional de pacientes con diabetes mellitus y pié ulcerado Functional capability of patients with diabetes with foot ulceration

    Directory of Open Access Journals (Sweden)

    Geraldo Magela Salomé

    2009-01-01

    Full Text Available OBJETIVO: Avaliar a capacidade funcional de pessoas com diabetes mellitus e pé ulcerado. MÉTODOS: Estudo analítico, transversal e comparativo, realizado em hospital público do município de São Paulo, sendo os dados coletados no período de 2 de junho a 30 julho de 2008. Foram selecionados para compor o Grupo de Estudo, 20 pacientes com diabetes mellitus e pé ulcerado; para o Grupo Controle 20 pessoas com diagnóstico médico de diabetes mellitus, sem úlcera no pé. O instrumento utilizado foi Health Assessment Questionnaire-20. RESULTADOS: O grupo estudo diferiu do grupo controle, quanto ao escores HAQ-20, bem como em relação aos componentes 1,2,3,5,6,7 e 8. Também apresentaram diferença estatística significante (POBJETIVO: Evaluar la capacidad funcional de personas con diabetes mellitus y pié ulcerado. MÉTODOS: Se trata de un estudio analítico, transversal y comparativo, realizado en un hospital público del municipio de Sao Paulo, cuyos datos fueron recolectados en el período del 2 de junio al 30 julio del 2008. Fueron seleccionados para componer el Grupo de Estudio, 20 pacientes con diabetes mellitus y pié ulcerado; para el Grupo Control 20 personas con diagnóstico médico de diabetes mellitus, sin úlcera en el pié. El instrumento utilizado fue el Health Assessment Questionnaire-20. RESULTADOS: El grupo de estudio difirió del grupo control, en cuanto a los escores HAQ-20, así como en relación a los componentes 1,2,3,5,6,7 y 8. También presentaron diferencia estadísticamente significativa (POBJECTIVE: To evaluate and compare the functional capability of patients with diabetes with foot ulceration and patients with diabetes without foot ulceration. METHODS: A cross sectional descriptive comparative study was conducted in a public hospital in the district of São Paulo. The sample consisted of 20 patients with foot ulceration and 20 patients without foot ulceration. Data were collected from June 2 to July 30, 2008. The

  15. Multiscale simulations of anisotropic particles combining Brownian Dynamics and Green's Function Reaction Dynamics

    CERN Document Server

    Vijaykumar, Adithya; Wolde, Pieter Rein ten; Bolhuis, Peter G

    2016-01-01

    The modeling of complex reaction-diffusion processes in, for instance, cellular biochemical networks or self-assembling soft matter can be tremendously sped up by employing a multiscale algorithm which combines the mesoscopic Green's Function Reaction Dynamics (GFRD) method with explicit stochastic Brownian, Langevin, or deterministic Molecular Dynamics to treat reactants at the microscopic scale [A. Vijaykumar, P.G. Bolhuis and P.R. ten Wolde, J. Chem. Phys. {\\bf 43}, 21: 214102 (2015)]. Here we extend this multiscale BD-GFRD approach to include the orientational dynamics that is crucial to describe the anisotropic interactions often prevalent in biomolecular systems. We illustrate the novel algorithm using a simple patchy particle model. After validation of the algorithm we discuss its performance. The rotational BD-GFRD multiscale method will open up the possibility for large scale simulations of e.g. protein signalling networks.

  16. [Disorders of statics of the foot and chronic venous insufficiency].

    Science.gov (United States)

    Peresa, M; Krajcar, J

    1987-01-01

    The aim of this study was to confirm a fact known in the relevant literature that there is a correlation between static anomalies of the sole, and varicose veins, a consequence of the decreased quality of the conjunctive tissue. We cite genetic and dynamic factors by way of explanation. To confirm the fact that deformities of the sole of the foot are linked with chronic venous incompetence and influence the functional capacity of the muscular pump, the authors have analysed in young subjects the contractile capacity of the pump even when the index of reduction in the sole of the foot was quite low. The muscular pump in the calf is a compensatory system from the point of view of functional capacity. The authors noted that the velocimetric parameter of speed of flux in the femoral vein is a sensitive parameter and changes rapidly, rising with even minimal activity in the calf. The authors think that acquired deformities are one of the most frequent causes of the poor functioning of the muscular pump in the calf.

  17. Dynamics of localized particles from density functional theory

    Science.gov (United States)

    Reinhardt, J.; Brader, J. M.

    2012-01-01

    A fundamental assumption of the dynamical density functional theory (DDFT) of colloidal systems is that a grand-canonical free-energy functional may be employed to generate the thermodynamic driving forces. Using one-dimensional hard rods as a model system, we analyze the validity of this key assumption and show that unphysical self-interactions of the tagged particle density fields, arising from coupling to a particle reservoir, are responsible for the excessively fast relaxation predicted by the theory. Moreover, our findings suggest that even employing a canonical functional would not lead to an improvement for many-particle systems, if only the total density is considered. We present several possible schemes to suppress these effects by incorporating tagged densities. When applied to confined systems, we demonstrate, using a simple example, that DDFT necessarily leads to delocalized tagged particle density distributions, which do not respect the fundamental geometrical constraints apparent in Brownian dynamics simulation data. The implication of these results for possible applications of DDFT to treat the glass transition are discussed.

  18. Dynamic density functional theory with hydrodynamic interactions and fluctuations

    Energy Technology Data Exchange (ETDEWEB)

    Donev, Aleksandar, E-mail: donev@courant.nyu.edu; Vanden-Eijnden, Eric, E-mail: eve2@courant.nyu.edu [Courant Institute of Mathematical Sciences, New York University, New York, New York 10012 (United States)

    2014-06-21

    We derive a closed equation for the empirical concentration of colloidal particles in the presence of both hydrodynamic and direct interactions. The ensemble average of our functional Langevin equation reproduces known deterministic Dynamic Density Functional Theory (DDFT) [M. Rex and H. Löwen, “Dynamical density functional theory with hydrodynamic interactions and colloids in unstable traps,” Phys. Rev. Lett. 101(14), 148302 (2008)], and, at the same time, it also describes the microscopic fluctuations around the mean behavior. We suggest separating the ideal (non-interacting) contribution from additional corrections due to pairwise interactions. We find that, for an incompressible fluid and in the absence of direct interactions, the mean concentration follows Fick's law just as for uncorrelated walkers. At the same time, the nature of the stochastic terms in fluctuating DDFT is shown to be distinctly different for hydrodynamically-correlated and uncorrelated walkers. This leads to striking differences in the behavior of the fluctuations around Fick's law, even in the absence of pairwise interactions. We connect our own prior work [A. Donev, T. G. Fai, and E. Vanden-Eijnden, “A reversible mesoscopic model of diffusion in liquids: from giant fluctuations to Fick's law,” J. Stat. Mech.: Theory Exp. (2014) P04004] on fluctuating hydrodynamics of diffusion in liquids to the DDFT literature, and demonstrate that the fluid cannot easily be eliminated from consideration if one wants to describe the collective diffusion in colloidal suspensions.

  19. Bacterial dynamics in steady-state biofilters: beyond functional stability.

    Science.gov (United States)

    Cabrol, Léa; Malhautier, Luc; Poly, Franck; Lepeuple, Anne-Sophie; Fanlo, Jean-Louis

    2012-01-01

    The spatial and temporal dynamics of microbial community structure and function were surveyed in duplicated woodchip-biofilters operated under constant conditions for 231 days. The contaminated gaseous stream for treatment was representative of composting emissions, included ammonia, dimethyl disulfide and a mixture of five oxygenated volatile organic compounds. The community structure and diversity were investigated by denaturing gradient gel electrophoresis on 16S rRNA gene fragments. During the first 42 days, microbial acclimatization revealed the influence of operating conditions and contaminant loading on the biofiltration community structure and diversity, as well as the limited impact of inoculum compared to the greater persistence of the endogenous woodchip community. During long-term operation, a high and stable removal efficiency was maintained despite a highly dynamic microbial community, suggesting the probable functional redundancy of the community. Most of the contaminant removal occurred in the first compartment, near the gas inlet, where the microbial diversity was the highest. The stratification of the microbial structures along the filter bed was statistically correlated to the longitudinal distribution of environmental conditions (selective pressure imposed by contaminant concentrations) and function (contaminant elimination capacity), highlighting the central role of the bacterial community. The reproducibility of microbial succession in replicates suggests that the community changes were presumably driven by a deterministic process.

  20. Foot Push-Up Test

    Science.gov (United States)

    ... may be inflamed and may have been overworked. Consulting a foot and ankle surgeon for weak and ... or last name. Search Where do you hurt? Interactive Foot Diagram Arch Supports Arch supports are devices ...

  1. Moments of meson distribution functions with dynamical twisted mass fermions

    CERN Document Server

    Baron, R; Carbonell, J; Jansen, K; Liu, Z; Pène, O; Urbach, C

    2007-01-01

    We present our preliminary results on the lowest moment of quark distribution functions of the pion using two flavor dynamical simulations with Wilson twisted mass fermions at maximal twist. The calculation is done in a range of pion masses from 300 to 500 MeV. A stochastic source method is used to reduce inversions in calculating propagators. Finite volume effects at the lowest quark mass are examined by using two different lattice volumes. Our results show that we achieve statistical errors of only a few percent. We plan to compute renormalization constants non-perturbatively and extend the calculation to two more lattice spacings and to the nucleons.

  2. Dynamically Consistent Nonlinear Evaluations with Their Generating Functions in Lp

    Institute of Scientific and Technical Information of China (English)

    Feng HU

    2013-01-01

    In this paper,we study dynamically consistent nonlinear evaluations in Lp (1 < p < 2).One of our aim is to obtain the following result:under a domination condition,an Ft-consistent evaluation is an ∑g-evaluation in Lp.Furthermore,without the assumption that the generating function g(t,ω,y,z) is continuous with respect to t,we provide some useful characterizations of an εg-evaluation by g and give some applications.These results include and extend some existing results.

  3. What Is a Foot and Ankle Surgeon?

    Science.gov (United States)

    ... Foot & Ankle Surgeon? A A A | Print | Share What is a Foot & Ankle Surgeon? Foot and ankle ... of conditions that affect people of every age. What education has a foot and ankle surgeon received? ...

  4. Osteomyelitis in the diabetic foot

    OpenAIRE

    Malhotra, Rishi; Chan, Claire Shu-Yi; Nather, Aziz

    2014-01-01

    Osteomyelitis (OM) is a common complication of diabetic foot ulcers and/or diabetic foot infections. This review article discusses the clinical presentation, diagnosis, and treatment of OM in the diabetic foot. Clinical features that point to the possibility of OM include the presence of exposed bone in the depth of a diabetic foot ulcer. Medical imaging studies include plain radiographs, magnetic resonance imaging, and bone scintigraphy. A high index of suspicion is also required to make the...

  5. Biological oscillations for learning walking coordination: dynamic recurrent neural network functionally models physiological central pattern generator.

    Science.gov (United States)

    Hoellinger, Thomas; Petieau, Mathieu; Duvinage, Matthieu; Castermans, Thierry; Seetharaman, Karthik; Cebolla, Ana-Maria; Bengoetxea, Ana; Ivanenko, Yuri; Dan, Bernard; Cheron, Guy

    2013-01-01

    The existence of dedicated neuronal modules such as those organized in the cerebral cortex, thalamus, basal ganglia, cerebellum, or spinal cord raises the question of how these functional modules are coordinated for appropriate motor behavior. Study of human locomotion offers an interesting field for addressing this central question. The coordination of the elevation of the 3 leg segments under a planar covariation rule (Borghese et al., 1996) was recently modeled (Barliya et al., 2009) by phase-adjusted simple oscillators shedding new light on the understanding of the central pattern generator (CPG) processing relevant oscillation signals. We describe the use of a dynamic recurrent neural network (DRNN) mimicking the natural oscillatory behavior of human locomotion for reproducing the planar covariation rule in both legs at different walking speeds. Neural network learning was based on sinusoid signals integrating frequency and amplitude features of the first three harmonics of the sagittal elevation angles of the thigh, shank, and foot of each lower limb. We verified the biological plausibility of the neural networks. Best results were obtained with oscillations extracted from the first three harmonics in comparison to oscillations outside the harmonic frequency peaks. Physiological replication steadily increased with the number of neuronal units from 1 to 80, where similarity index reached 0.99. Analysis of synaptic weighting showed that the proportion of inhibitory connections consistently increased with the number of neuronal units in the DRNN. This emerging property in the artificial neural networks resonates with recent advances in neurophysiology of inhibitory neurons that are involved in central nervous system oscillatory activities. The main message of this study is that this type of DRNN may offer a useful model of physiological central pattern generator for gaining insights in basic research and developing clinical applications.

  6. Biological oscillations for learning walking coordination: dynamic recurrent neural network functionally models physiological central pattern generator

    Directory of Open Access Journals (Sweden)

    Thomas eHoellinger

    2013-05-01

    Full Text Available The existence of dedicated neuronal modules such as those organized in the cerebral cortex, thalamus, basal ganglia, cerebellum or spinal cord raises the question of how these functional modules are coordinated for appropriate motor behavior. Study of human locomotion offers an interesting field for addressing this central question. The coordination of the elevation of the 3 leg segments under a planar covariation rule (Borghese et al., 1996 was recently modeled (Barliya et al., 2009 by phase-adjusted simple oscillators shedding new light on the understanding of the central pattern generator processing relevant oscillation signals. We describe the use of a dynamic recurrent neural network (DRNN mimicking the natural oscillatory behavior of human locomotion for reproducing the planar covariation rule in both legs at different walking speeds. Neural network learning was based on sinusoid signals integrating frequency and amplitude features of the first three harmonics of the sagittal elevation angles of the thigh, shank and foot of each lower limb. We verified the biological plausibility of the neural networks. Best results were obtained with oscillations extracted from the first three harmonics in comparison to oscillations outside the harmonic frequency peaks. Physiological replication steadily increased with the number of neuronal units from 1 to 80, where similarity index reached 0.99. Analysis of synaptic weighting showed that the proportion of inhibitory connections consistently increased with the number of neuronal units in the DRNN. This emerging property in the artificial neural networks resonates with recent advances in neurophysiology of inhibitory neurons that are involved in central nervous system oscillatory activities. The main message of this study is that this type of DRNN may offer a useful model of physiological central pattern generator for gaining insights in basic research and developing clinical applications.

  7. Adult cavovarus foot.

    Science.gov (United States)

    Younger, Alastair S E; Hansen, Sigvard T

    2005-09-01

    Cavovarus foot deformity, which often results from an imbalance of muscle forces, is commonly caused by hereditary motor sensory neuropathies. Other causes are cerebral palsy, cerebral injury (stroke), anterior horn cell disease (spinal root injury), talar neck injury, and residual clubfoot. In cavovarus foot deformity, the relatively strong peroneus longus and tibialis posterior muscles cause a hindfoot varus and forefoot valgus (pronated) position. Hindfoot varus causes overload of the lateral border of the foot, resulting in ankle instability, peroneal tendinitis, and stress fracture. Degenerative arthritic changes can develop in overloaded joints. Gait examination allows appropriate planning of tendon transfers to correct stance and swing-phase deficits. Inspection of the forefoot and hindfoot positions determines the need for soft-tissue release and osteotomy. The Coleman block test is invaluable for assessing the cause of hindfoot varus. Prolonged use of orthoses or supportive footwear can result in muscle imbalance, causing increasing deformity and irreversible damage to tendons and joints. Rebalancing tendons is an early priority to prevent unsalvageable deterioration of the foot. Muscle imbalance can be corrected by tendon transfer, corrective osteotomy, and fusion. Fixed bony deformity can be addressed by fusion and osteotomy.

  8. Clinical workflow for personalized foot pressure ulcer prevention.

    Science.gov (United States)

    Bucki, M; Luboz, V; Perrier, A; Champion, E; Diot, B; Vuillerme, N; Payan, Y

    2016-09-01

    Foot pressure ulcers are a common complication of diabetes because of patient's lack of sensitivity due to neuropathy. Deep pressure ulcers appear internally when pressures applied on the foot create high internal strains nearby bony structures. Monitoring tissue strains in persons with diabetes is therefore important for an efficient prevention. We propose to use personalized biomechanical foot models to assess strains within the foot and to determine the risk of ulcer formation. Our workflow generates a foot model adapted to a patient's morphology by deforming an atlas model to conform it to the contours of segmented medical images of the patient's foot. Our biomechanical model is composed of rigid bodies for the bones, joined by ligaments and muscles, and a finite element mesh representing the soft tissues. Using our registration algorithm to conform three datasets, three new patient models were created. After applying a pressure load below these foot models, the Von Mises equivalent strains and "cluster volumes" (i.e. volumes of contiguous elements with strains above a given threshold) were measured within eight functionally meaningful foot regions. The results show the variability of both location and strain values among the three considered patients. This study also confirms that the anatomy of the foot has an influence on the risk of pressure ulcer. Copyright © 2016. Published by Elsevier Ltd.

  9. Mining dynamic noteworthy functions in software execution sequences.

    Science.gov (United States)

    Zhang, Bing; Huang, Guoyan; Wang, Yuqian; He, Haitao; Ren, Jiadong

    2017-01-01

    As the quality of crucial entities can directly affect that of software, their identification and protection become an important premise for effective software development, management, maintenance and testing, which thus contribute to improving the software quality and its attack-defending ability. Most analysis and evaluation on important entities like codes-based static structure analysis are on the destruction of the actual software running. In this paper, from the perspective of software execution process, we proposed an approach to mine dynamic noteworthy functions (DNFM)in software execution sequences. First, according to software decompiling and tracking stack changes, the execution traces composed of a series of function addresses were acquired. Then these traces were modeled as execution sequences and then simplified so as to get simplified sequences (SFS), followed by the extraction of patterns through pattern extraction (PE) algorithm from SFS. After that, evaluating indicators inner-importance and inter-importance were designed to measure the noteworthiness of functions in DNFM algorithm. Finally, these functions were sorted by their noteworthiness. Comparison and contrast were conducted on the experiment results from two traditional complex network-based node mining methods, namely PageRank and DegreeRank. The results show that the DNFM method can mine noteworthy functions in software effectively and precisely.

  10. Mining dynamic noteworthy functions in software execution sequences

    Science.gov (United States)

    Huang, Guoyan; Wang, Yuqian; He, Haitao; Ren, Jiadong

    2017-01-01

    As the quality of crucial entities can directly affect that of software, their identification and protection become an important premise for effective software development, management, maintenance and testing, which thus contribute to improving the software quality and its attack-defending ability. Most analysis and evaluation on important entities like codes-based static structure analysis are on the destruction of the actual software running. In this paper, from the perspective of software execution process, we proposed an approach to mine dynamic noteworthy functions (DNFM)in software execution sequences. First, according to software decompiling and tracking stack changes, the execution traces composed of a series of function addresses were acquired. Then these traces were modeled as execution sequences and then simplified so as to get simplified sequences (SFS), followed by the extraction of patterns through pattern extraction (PE) algorithm from SFS. After that, evaluating indicators inner-importance and inter-importance were designed to measure the noteworthiness of functions in DNFM algorithm. Finally, these functions were sorted by their noteworthiness. Comparison and contrast were conducted on the experiment results from two traditional complex network-based node mining methods, namely PageRank and DegreeRank. The results show that the DNFM method can mine noteworthy functions in software effectively and precisely. PMID:28278276

  11. X-Ray Exam: Foot

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Foot KidsHealth > For Parents > X-Ray Exam: Foot A A A What's in ... español Radiografía: pie What It Is A foot X-ray is a safe and painless test that ...

  12. Neuropathy and Diabetic Foot Syndrome.

    Science.gov (United States)

    Volmer-Thole, Maren; Lobmann, Ralf

    2016-06-10

    Diabetic foot ulceration is a serious complication of diabetes mellitus worldwide and the most common cause of hospitalization in diabetic patients. The etiology of diabetic foot ulcerations is complex due to their multifactorial nature; in the pathophysiology of diabetic foot ulceration polyneuropathy is important. Proper adherence to standard treatment strategies and interdisciplinary cooperation can reduce the still high rates of major amputations.

  13. Mindfulness and dynamic functional neural connectivity in children and adolescents.

    Science.gov (United States)

    Marusak, Hilary A; Elrahal, Farrah; Peters, Craig A; Kundu, Prantik; Lombardo, Michael V; Calhoun, Vince D; Goldberg, Elimelech K; Cohen, Cindy; Taub, Jeffrey W; Rabinak, Christine A

    2017-09-05

    Interventions that promote mindfulness consistently show salutary effects on cognition and emotional wellbeing in adults, and more recently, in children and adolescents. However, we lack understanding of the neurobiological mechanisms underlying mindfulness in youth that should allow for more judicious application of these interventions in clinical and educational settings. Using multi-echo multi-band fMRI, we examined dynamic (i.e., time-varying) and conventional static resting-state connectivity between core neurocognitive networks (i.e., salience/emotion, default mode, central executive) in 42 children and adolescents (ages 6-17). We found that trait mindfulness in youth relates to dynamic but not static resting-state connectivity. Specifically, more mindful youth transitioned more between brain states over the course of the scan, spent overall less time in a certain connectivity state, and showed a state-specific reduction in connectivity between salience/emotion and central executive networks. The number of state transitions mediated the link between higher mindfulness and lower anxiety, providing new insights into potential neural mechanisms underlying benefits of mindfulness on psychological health in youth. Our results provide new evidence that mindfulness in youth relates to functional neural dynamics and interactions between neurocognitive networks, over time. Copyright © 2017. Published by Elsevier B.V.

  14. Functional Loop Dynamics of the Streptavidin-Biotin Complex

    Science.gov (United States)

    Song, Jianing; Li, Yongle; Ji, Changge; Zhang, John Z. H.

    2015-01-01

    Accelerated molecular dynamics (aMD) simulation is employed to study the functional dynamics of the flexible loop3-4 in the strong-binding streptavidin-biotin complex system. Conventional molecular (cMD) simulation is also performed for comparison. The present study reveals the following important properties of the loop dynamics: (1) The transition of loop3-4 from open to closed state is observed in 200 ns aMD simulation. (2) In the absence of biotin binding, the open-state streptavidin is more stable, which is consistent with experimental evidences. The free energy (ΔG) difference is about 5 kcal/mol between two states. But with biotin binding, the closed state is more stable due to electrostatic and hydrophobic interactions between the loop3-4 and biotin. (3) The closure of loop3-4 is concerted to the stable binding of biotin to streptavidin. When the loop3-4 is in its open-state, biotin moves out of the binding pocket, indicating that the interactions between the loop3-4 and biotin are essential in trapping biotin in the binding pocket. (4) In the tetrameric streptavidin system, the conformational change of the loop3-4 in each monomer is independent of each other. That is, there is no cooperative binding for biotin bound to the four subunits of the tetramer.

  15. Functional clustering algorithm for the analysis of dynamic network data

    Science.gov (United States)

    Feldt, S.; Waddell, J.; Hetrick, V. L.; Berke, J. D.; Żochowski, M.

    2009-05-01

    We formulate a technique for the detection of functional clusters in discrete event data. The advantage of this algorithm is that no prior knowledge of the number of functional groups is needed, as our procedure progressively combines data traces and derives the optimal clustering cutoff in a simple and intuitive manner through the use of surrogate data sets. In order to demonstrate the power of this algorithm to detect changes in network dynamics and connectivity, we apply it to both simulated neural spike train data and real neural data obtained from the mouse hippocampus during exploration and slow-wave sleep. Using the simulated data, we show that our algorithm performs better than existing methods. In the experimental data, we observe state-dependent clustering patterns consistent with known neurophysiological processes involved in memory consolidation.

  16. Ephemeral penalty functions for contact-impact dynamics

    Science.gov (United States)

    De La Fuente, Horacio M.; Felippa, Carlos A.

    1991-01-01

    The use of penalty functions to treat a class of structural contact-impact problems is investigated, with emphasis on ones in which the impact phenomena are primarily nondestructive in nature and in which only the gross characterization of the response is required. The dynamic equations of motion are integrated by the difference method. The penalty is represented as an ephemeral fictitious nonlinear spring that is inserted on anticipation of contact. The magnitude and variation of the penalty force is determined through energy balancing considerations. The 'bell shape' of the penalty force function for positive gap was found to be satisfactory, as it depends on only two parameters that can be directly assigned the physical meaning of force and distance. The determination of force law parameters by energy balance worked well. The incorporation of restitution coefficients by the area balancing method yielded excellent results, and no substantial modifications are anticipated. Extensional penalty springs are obviously sufficient for the simple examples treated.

  17. Diffusion of innovations dynamics, biological growth and catenary function

    Science.gov (United States)

    Guseo, Renato

    2016-12-01

    The catenary function has a well-known role in determining the shape of chains and cables supported at their ends under the force of gravity. This enables design using a specific static equilibrium over space. Its reflected version, the catenary arch, allows the construction of bridges and arches exploiting the dual equilibrium property under uniform compression. In this paper, we emphasize a further connection with well-known aggregate biological growth models over time and the related diffusion of innovation key paradigms (e.g., logistic and Bass distributions over time) that determine self-sustaining evolutionary growth dynamics in naturalistic and socio-economic contexts. Moreover, we prove that the 'local entropy function', related to a logistic distribution, is a catenary and vice versa. This special invariance may be explained, at a deeper level, through the Verlinde's conjecture on the origin of gravity as an effect of the entropic force.

  18. Time-dependent density-functional description of nuclear dynamics

    CERN Document Server

    Nakatsukasa, Takashi; Matsuo, Masayuki; Yabana, Kazuhiro

    2016-01-01

    We present the basic concepts and recent developments in the time-dependent density functional theory (TDDFT) for describing nuclear dynamics at low energy. The symmetry breaking is inherent in nuclear energy density functionals (EDFs), which provides a practical description of important correlations at the ground state. Properties of elementary modes of excitation are strongly influenced by the symmetry breaking and can be studied with TDDFT. In particular, a number of recent developments in the linear response calculation have demonstrated their usefulness in description of collective modes of excitation in nuclei. Unrestricted real-time calculations have also become available in recent years, with new developments for quantitative description of nuclear collision phenomena. There are, however, limitations in the real-time approach; for instance, it cannot describe the many-body quantum tunneling. Thus, we treat the quantum fluctuations associated with slow collective motions assuming that time evolution of...

  19. Scale effects in the dynamic transfer functions for cavitating inducers

    Science.gov (United States)

    Brennen, C. E.; Meissner, C.; Lo, E. Y.; Hoffman, G. S.

    1980-01-01

    Dynamic transfer functions for two cavitating inducers of the same geometry but different size are presented, compared and discussed. The transfer functions for each inducer indicate similar trends as the cavitation number is decreased; only minor changes are noted with changes in the flow coefficient, the uniformity of the inlet flow or the temperature of the water (21-74 C). The non-dimensional results for the two sizes are compared with themselves and with theoretical calculations based on the bubbly flow model. All three sets of results compare well and lend further credence to the theoretical model. The best values of the two parameters in the model are evaluated and recommended for use in applications.

  20. Method and apparatus for monitoring dynamic cardiovascular function using n-dimensional representatives of critical functions

    Science.gov (United States)

    Westinskow, Dwayne (Inventor); Agutter, James (Inventor); Syroid, Noah (Inventor); Strayer, David (Inventor); Albert, Robert (Inventor); Wachter, S. Blake (Inventor); Drews, Frank (Inventor)

    2010-01-01

    A method, system, apparatus and device for the monitoring, diagnosis and evaluation of the state of a dynamic pulmonary system is disclosed. This method and system provides the processing means for receiving sensed and/or simulated data, converting such data into a displayable object format and displaying such objects in a manner such that the interrelationships between the respective variables can be correlated and identified by a user. This invention provides for the rapid cognitive grasp of the overall state of a pulmonary critical function with respect to a dynamic system.

  1. 脑性瘫痪患儿踝足矫形器配戴前后对运动功能的量化评价%Quantitative assessment of motor function on children with cerebral palsy before and after wearing ankle foot orthopedic instruments

    Institute of Scientific and Technical Information of China (English)

    李润洁

    2002-01-01

    Objective To assess motor function quantitatively on children with cerebral palsy before and after wearing ankle foot orthopedic instruments.Method Ankle foot orthopedic instruments were made by Dalian Prosthesis Factory.Children' motor function was assessed with self made quantitative assessment scale according to the forth,fifth function area of motor assessment scale of children with cerebral palsy after one week of wearing orthopedic instruments. Result In all 23 patients, orthopedic instruments proved effective in controlling leg muscular tension,correcting equines,genu recurvatum,talips valgus and talipes varus,keeping erect posture and modifying gait.Motor function assessed show significant difference before and one week after wearing orthopedic instruments (P< 0.001).Conclusion Ankle foot orthopedic instruments play a positive role in improving motor function of lower extremity in cerebral palsy patients.

  2. A Comparative Study on Optimal Structural Dynamics Using Wavelet Functions

    Directory of Open Access Journals (Sweden)

    Seyed Hossein Mahdavi

    2015-01-01

    Full Text Available Wavelet solution techniques have become the focus of interest among researchers in different disciplines of science and technology. In this paper, implementation of two different wavelet basis functions has been comparatively considered for dynamic analysis of structures. For this aim, computational technique is developed by using free scale of simple Haar wavelet, initially. Later, complex and continuous Chebyshev wavelet basis functions are presented to improve the time history analysis of structures. Free-scaled Chebyshev coefficient matrix and operation of integration are derived to directly approximate displacements of the corresponding system. In addition, stability of responses has been investigated for the proposed algorithm of discrete Haar wavelet compared against continuous Chebyshev wavelet. To demonstrate the validity of the wavelet-based algorithms, aforesaid schemes have been extended to the linear and nonlinear structural dynamics. The effectiveness of free-scaled Chebyshev wavelet has been compared with simple Haar wavelet and two common integration methods. It is deduced that either indirect method proposed for discrete Haar wavelet or direct approach for continuous Chebyshev wavelet is unconditionally stable. Finally, it is concluded that numerical solution is highly benefited by the least computation time involved and high accuracy of response, particularly using low scale of complex Chebyshev wavelet.

  3. Multiscale functions, Scale dynamics and Applications to partial differential equations

    CERN Document Server

    Cresson, Jacky

    2015-01-01

    Modeling phenomena from experimental data, always begin with a \\emph{choice of hypothesis} on the observed dynamics such as \\emph{determinism}, \\emph{randomness}, \\emph{derivability} etc. Depending on these choices, different behaviors can be observed. The natural question associated to the modeling problem is the following : \\emph{"With a finite set of data concerning a phenomenon, can we recover its underlying nature ?} From this problem, we introduce in this paper the definition of \\emph{multi-scale functions}, \\emph{scale calculus} and \\emph{scale dynamics} based on the \\emph{time-scale calculus} (see \\cite{bohn}). These definitions will be illustrated on the \\emph{multi-scale Okamoto's functions}. The introduced formalism explains why there exists different continuous models associated to an equation with different \\emph{scale regimes} whereas the equation is \\emph{scale invariant}. A typical example of such an equation, is the \\emph{Euler-Lagrange equation} and particularly the \\emph{Newton's equation} ...

  4. Coastal rainforest boundary dynamics during the late Holocene in monsoonal Australia: evidence from radiocarbon dates of abandoned nests of Orange-footed Scrubfowl

    Energy Technology Data Exchange (ETDEWEB)

    Bowman, D.M.J.S.; Panton, W.J. [Parks and Wildlife Commission of the Northern Territory, Darwin, NT (Australia); Head, J. [Australian National Univ, Canberra, ACT (Australia). Quaternary Dating Research Centre

    1997-12-31

    The late Holocene history of monsoon rainforest retreat was explored by radiocarbon dating abandoned Orange-footed Scrubfowl (Megapodius reinwardt Gaimard) nests in coastal savannas in the Northern Territory of Australia. Previous work has demonstrated that in savanna environments this rainforest bird can not build nor maintain the large heaps of soil and leaf litter that it uses for nests. Excavations of two earthen mounds in a savanna habitat verified that they were abandoned Scrubfowl nests, and not Aboriginal middens, given their lack of stratigraphy, non-sequential dating of charcoal in a vertical profile, and absence of archaeological material. Radiocarbon dates of material taken from the surface of abandoned nests were determined for three sites on the coast of the Northern Territory. These analyses revealed that for all three sites, rainforests have contracted within the last 1800 years BP. On Elcho Island an abandoned nest was found to contain the land snail Xanthomelon spheroidea Le Guillou (known to prefer rainforest habitat) with a modern radiocarbon age, suggesting recent contraction of rainforest. The results of this study further weaken the theory that Aboriginal burning was a major cause of rain forest fragmentation in the monsoon tropics, and possibly elsewhere in Australia.

  5. Foot mounted inertial system for pedestrian navigation

    Science.gov (United States)

    Godha, S.; Lachapelle, G.

    2008-07-01

    This paper discusses algorithmic concepts, design and testing of a system based on a low-cost MEMS-based inertial measurement unit (IMU) and high-sensitivity global positioning system (HSGPS) receivers for seamless personal navigation in a GPS signal degraded environment. The system developed here is mounted on a pedestrian shoe/foot and uses measurements based on the dynamics experienced by the inertial sensors on the user's foot. The IMU measurements are processed through a conventional inertial navigation system (INS) algorithm and are then integrated with HSGPS receiver measurements and dynamics derived constraint measurements using a tightly coupled integration strategy. The ability of INS to bridge the navigation solution is evaluated through field tests conducted indoors and in severely signal degraded forest environments. The specific focus is on evaluating system performance under challenging GPS conditions.

  6. Comparative Anthropometry of the Foot

    Science.gov (United States)

    1982-12-01

    height, angular orientatior of metatarsal heads, lateral foot contour, plantar arch height, dorsal arch height, breadth of instep, instep girth...with ball length and ball girth, namely the dorsal and plantar arch heights, foot flare, and the angular orientation of the heads of the metatarsals, may...57. RIVARIATE TABE OF BALL OF FOOT CIRCUMFERENCE AND FOOT BREADTH FOR U. S. ARMY WOMEN (1977) FOOT BREADTH Centimeters 7.5 8.0 8.5 9.0 9.5 10.0 10.5

  7. Functional dynamic factor models with application to yield curve forecasting

    KAUST Repository

    Hays, Spencer

    2012-09-01

    Accurate forecasting of zero coupon bond yields for a continuum of maturities is paramount to bond portfolio management and derivative security pricing. Yet a universal model for yield curve forecasting has been elusive, and prior attempts often resulted in a trade-off between goodness of fit and consistency with economic theory. To address this, herein we propose a novel formulation which connects the dynamic factor model (DFM) framework with concepts from functional data analysis: a DFM with functional factor loading curves. This results in a model capable of forecasting functional time series. Further, in the yield curve context we show that the model retains economic interpretation. Model estimation is achieved through an expectation- maximization algorithm, where the time series parameters and factor loading curves are simultaneously estimated in a single step. Efficient computing is implemented and a data-driven smoothing parameter is nicely incorporated. We show that our model performs very well on forecasting actual yield data compared with existing approaches, especially in regard to profit-based assessment for an innovative trading exercise. We further illustrate the viability of our model to applications outside of yield forecasting.

  8. Structure/Function/Dynamics of Photosystem II Plastoquinone Binding Sites

    Science.gov (United States)

    Lambreva, Maya D.; Russo, Daniela; Polticelli, Fabio; Scognamiglio, Viviana; Antonacci, Amina; Zobnina, Veranika; Campi, Gaetano; Rea, Giuseppina

    2014-01-01

    Photosystem II (PSII) continuously attracts the attention of researchers aiming to unravel the riddle of its functioning and efficiency fundamental for all life on Earth. Besides, an increasing number of biotechnological applications have been envisaged exploiting and mimicking the unique properties of this macromolecular pigment-protein complex. The PSII organization and working principles have inspired the design of electrochemical water splitting schemes and charge separating triads in energy storage systems as well as biochips and sensors for environmental, agricultural and industrial screening of toxic compounds. An intriguing opportunity is the development of sensor devices, exploiting native or manipulated PSII complexes or ad hoc synthesized polypeptides mimicking the PSII reaction centre proteins as bio-sensing elements. This review offers a concise overview of the recent improvements in the understanding of structure and function of PSII donor side, with focus on the interactions of the plastoquinone cofactors with the surrounding environment and operational features. Furthermore, studies focused on photosynthetic proteins structure/function/dynamics and computational analyses aimed at rational design of high-quality bio-recognition elements in biosensor devices are discussed. PMID:24678671

  9. Function-valued adaptive dynamics and optimal control theory.

    Science.gov (United States)

    Parvinen, Kalle; Heino, Mikko; Dieckmann, Ulf

    2013-09-01

    In this article we further develop the theory of adaptive dynamics of function-valued traits. Previous work has concentrated on models for which invasion fitness can be written as an integral in which the integrand for each argument value is a function of the strategy value at that argument value only. For this type of models of direct effect, singular strategies can be found using the calculus of variations, with singular strategies needing to satisfy Euler's equation with environmental feedback. In a broader, more mechanistically oriented class of models, the function-valued strategy affects a process described by differential equations, and fitness can be expressed as an integral in which the integrand for each argument value depends both on the strategy and on process variables at that argument value. In general, the calculus of variations cannot help analyzing this much broader class of models. Here we explain how to find singular strategies in this class of process-mediated models using optimal control theory. In particular, we show that singular strategies need to satisfy Pontryagin's maximum principle with environmental feedback. We demonstrate the utility of this approach by studying the evolution of strategies determining seasonal flowering schedules.

  10. The athlete's foot.

    Science.gov (United States)

    Resnik, S S; Lewis, L A; Cohen, B H

    1977-09-01

    In general, painful feet can affect the performance of an athlete in any sport. To prevent skin diseases of the feet, the "Athlete's Foot" should be kept clean and dry with toenails trimmed. Properly fitting athletic shoes should be worn to avoid the formation of blisters. Wearing of sandals in locker and shower rooms, which prevents intimate contact with infecting organisms, can alleviate many of the problems that affect the feet.

  11. The effects of common footwear on stance-phase mechanical properties of the prosthetic foot-shoe system.

    Science.gov (United States)

    Major, Matthew J; Scham, Joel; Orendurff, Michael

    2017-05-01

    Prosthetic feet are prescribed based on their mechanical function and user functional level. Subtle changes to the stiffness and hysteresis of heel, midfoot, and forefoot regions can influence the dynamics and economy of gait in prosthesis users. However, the user's choice of shoes may alter the prosthetic foot-shoe system mechanical characteristics, compromising carefully prescribed and rigorously engineered performance of feet. Observe the effects of footwear on the mechanical properties of the prosthetic foot-shoe system including commonly prescribed prosthetic feet. Repeated-measures, Mechanical characterization. The stiffness and energy return was measured using a hydraulic-driven materials test machine across combinations of five prosthetic feet and four common shoes as well as a barefoot condition. Heel energy return decreased by an average 4%-9% across feet in all shoes compared to barefoot, with a cushioned trainer displaying the greatest effect. Foot designs that may improve perceived stability by providing low heel stiffness and rapid foot-flat were compromised by the addition of shoes. Shoes altered prosthesis mechanical characteristics in the sagittal and frontal planes, suggesting that shoe type should be controlled or reported in research comparing prostheses. Understanding of how different shoes could alter certain gait-related characteristics of prostheses may aid decisions on footwear made by clinicians and prosthesis users. Clinical relevance Shoes can alter function of the prosthetic foot-shoe system in unexpected and sometimes undesirable ways, often causing similar behavior across setups despite differences in foot design, and prescribing clinicians should carefully consider these effects on prosthesis performance.

  12. Aircraft path planning for optimal imaging using dynamic cost functions

    Science.gov (United States)

    Christie, Gordon; Chaudhry, Haseeb; Kochersberger, Kevin

    2015-05-01

    Unmanned aircraft development has accelerated with recent technological improvements in sensing and communications, which has resulted in an "applications lag" for how these aircraft can best be utilized. The aircraft are becoming smaller, more maneuverable and have longer endurance to perform sensing and sampling missions, but operating them aggressively to exploit these capabilities has not been a primary focus in unmanned systems development. This paper addresses a means of aerial vehicle path planning to provide a realistic optimal path in acquiring imagery for structure from motion (SfM) reconstructions and performing radiation surveys. This method will allow SfM reconstructions to occur accurately and with minimal flight time so that the reconstructions can be executed efficiently. An assumption is made that we have 3D point cloud data available prior to the flight. A discrete set of scan lines are proposed for the given area that are scored based on visibility of the scene. Our approach finds a time-efficient path and calculates trajectories between scan lines and over obstacles encountered along those scan lines. Aircraft dynamics are incorporated into the path planning algorithm as dynamic cost functions to create optimal imaging paths in minimum time. Simulations of the path planning algorithm are shown for an urban environment. We also present our approach for image-based terrain mapping, which is able to efficiently perform a 3D reconstruction of a large area without the use of GPS data.

  13. The neuropathic diabetic foot.

    Science.gov (United States)

    Rathur, Haris M; Boulton, Andrew J M

    2007-01-01

    Diabetic foot problems are common throughout the world, and result in major medical, social and economic consequences for the patients, their families, and society. Foot ulcers are likely to be of neuropathic origin and, therefore, are eminently preventable. Individuals with the greatest risk of ulceration can easily be identified by careful clinical examination of their feet: education and frequent follow-up is indicated for these patients. When infection complicates a foot ulcer, the combination can be limb-threatening, or life-threatening. Infection is defined clinically, but wound cultures assist in identification of causative pathogens. Tissue specimens are strongly preferred to wound swabs for wound cultures. Antimicrobial therapy should be guided by culture results, and although such therapy may cure the infection, it does not heal the wound. Alleviation of the mechanical load on ulcers (offloading) should always be a part of treatment. Plantar neuropathic ulcers typically heal in 6 weeks with nonremovable casts, because pressure at the ulcer site is mitigated and compliance is enforced. The success of other approaches to offloading similarly depends on the patient's adherence to the strategy used for pressure relief.

  14. The diabetic foot.

    Science.gov (United States)

    Rathur, Haris M; Boulton, Andrew J M

    2007-01-01

    Diabetic foot problems are common throughout the world, resulting in major medical, social and economic consequences for the patients, their families, and society. Foot ulcers are more likely to be of neuropathic origin, and therefore eminently preventable. People at greatest risk of ulceration can easily be identified by careful clinical examination of the feet: education and frequent follow-up is indicated for these patients. When infection complicates a foot ulcer, the combination can be limb or life-threatening. Infection is defined clinically, but wound cultures assist in identifying the causative pathogens. Tissue specimens are strongly preferred to wound swabs for wound cultures. Antimicrobial therapy should be guided by culture results, and although such therapy may cure the infection, it does not heal the wound. Alleviation of the mechanical load on ulcers (offloading) should always be a part of treatment. Plantar neuropathic ulcers typically heal in 6 weeks with irremovable casting, because pressure at the ulcer site is mitigated and compliance is enforced. The success of other approaches to offloading similarly depends on the patients' adherence to the effectiveness of pressure relief.

  15. Software tool for the prosthetic foot modeling and stiffness optimization.

    Science.gov (United States)

    Strbac, Matija; Popović, Dejan B

    2012-01-01

    We present the procedure for the optimization of the stiffness of the prosthetic foot. The procedure allows the selection of the elements of the foot and the materials used for the design. The procedure is based on the optimization where the cost function is the minimization of the difference between the knee joint torques of healthy walking and the walking with the transfemural prosthesis. We present a simulation environment that allows the user to interactively vary the foot geometry and track the changes in the knee torque that arise from these adjustments. The software allows the estimation of the optimal prosthetic foot elasticity and geometry. We show that altering model attributes such as the length of the elastic foot segment or its elasticity leads to significant changes in the estimated knee torque required for a given trajectory.

  16. Software Tool for the Prosthetic Foot Modeling and Stiffness Optimization

    Directory of Open Access Journals (Sweden)

    Matija Štrbac

    2012-01-01

    Full Text Available We present the procedure for the optimization of the stiffness of the prosthetic foot. The procedure allows the selection of the elements of the foot and the materials used for the design. The procedure is based on the optimization where the cost function is the minimization of the difference between the knee joint torques of healthy walking and the walking with the transfemural prosthesis. We present a simulation environment that allows the user to interactively vary the foot geometry and track the changes in the knee torque that arise from these adjustments. The software allows the estimation of the optimal prosthetic foot elasticity and geometry. We show that altering model attributes such as the length of the elastic foot segment or its elasticity leads to significant changes in the estimated knee torque required for a given trajectory.

  17. Lisfranc关节损伤后局部软组织损伤对足部功能的影响%Functional evaluation of foot after Lisfranc injury with local soft tissue injury

    Institute of Scientific and Technical Information of China (English)

    孙超; 王智; 张建中

    2010-01-01

    Objective To evaluate the foot function after Lisfranc injury with local soft tissue in-jury. Methods From November 2000 to April 2006, 43 patients (at mean age of 32 years) with fresh Lisfranc injuries (45 sides) were managed with open reduction and internal fixation with screws, Kir-schner wires and AO plates. All patients had no joint surface damage and received no fusion surgery. Ac-cording to the Quenu-Kuss classification of Lisfranc injury, there were 14 patients with type-A injury, 21 with type-B and 10 with type-C. According to AO classification, there were 29 feet without severe soft tis-sue injury and 16 feet with severe soft tissue injury, of which 10 patients were combined with severe local soft tissue injury (one patient with Foot compartment syndrome). The period from injury to surgery was seven days. All patients received cast immobilization for 8-12 weeks and the foot function was evaluated by anteroposterior and lateral X-rays and American Orthopedic Foot and Ankle Society (AOFAS) score. Results All patients were followed up for 12-69 months (average 37 months), which showed that all pa-tients obtained anatomic reduction and 32 patients were satisfied with operative outcome. The average postoperative AOFAS score was 97 points for patients without severe soft tissue injury and 82 points for pa-tients with severe soft tissue injury (P<0.05). Conclusion After Lisfranc injury, the foot function is related to severity of both joint injury and local soft tissue injury.%目的 评价Lisfranc关节损伤后局部软组织损伤程度与足部功能恢复程度之间的关系.方法 自2000年11月至2006年4月,共收治新鲜Lisfranc关节损伤患者43例(45足),平均年龄32岁.所有患者关节面均无毁损,未行融合手术,均行切开复位内固定,故可排除骨性因素影响.按跖跗关节损伤Quenu-Kuss分型:A型14足,B型21足,C型10足;按AO分类局部软组织损伤程度分为:不伴严重软组织损伤组29足

  18. The influence of cholesterol on membrane protein structure, function, and dynamics studied by molecular dynamics simulations.

    Science.gov (United States)

    Grouleff, Julie; Irudayam, Sheeba Jem; Skeby, Katrine K; Schiøtt, Birgit

    2015-09-01

    The plasma membrane, which encapsulates human cells, is composed of a complex mixture of lipids and embedded proteins. Emerging knowledge points towards the lipids as having a regulating role in protein function. Furthermore, insight from protein crystallography has revealed several different types of lipids intimately bound to membrane proteins and peptides, hereby possibly pointing to a site of action for the observed regulation. Cholesterol is among the lipid membrane constituents most often observed to be co-crystallized with membrane proteins, and the cholesterol levels in cell membranes have been found to play an essential role in health and disease. Remarkably little is known about the mechanism of lipid regulation of membrane protein function in health as well as in disease. Herein, we review molecular dynamics simulation studies aimed at investigating the effect of cholesterol on membrane protein and peptide properties. This article is part of a Special Issue entitled: Lipid-protein interactions. Copyright © 2015. Published by Elsevier B.V.

  19. Efficient foot motor control by Neymar’s brain

    Directory of Open Access Journals (Sweden)

    Eiichi eNaito

    2014-08-01

    Full Text Available How very long-term (over many years motor skill training shapes internal motor representation remains poorly understood. We provide valuable evidence that the football brain of Neymar da Silva Santos Júnior (the Brasilian footballer recruits very limited neural resources in the motor-cortical foot regions during foot movements. We scanned his brain activity with a 3-tesla functional magnetic resonance imaging (fMRI while he rotated his right ankle at 1Hz. We also scanned brain activity when three other age-controlled professional footballers, two top-athlete swimmers and one amateur footballer performed the identical task. A comparison was made between Neymar’s brain activity with that obtained from the others. We found activations in the left medial-wall foot motor regions during the foot movements consistently across all participants. However, the size and intensity of medial-wall activity was smaller in the four professional footballers than in the three other participants, despite no difference in amount of foot movement. Surprisingly, the reduced recruitment of medial-wall foot motor regions became apparent in Neymar. His medial-wall activity was smallest among all participants with absolutely no difference in amount of foot movement. Neymar may efficiently control given foot movements probably by largely conserving motor-cortical neural resources. We discuss this possibility in terms of over-years motor skill training effect, use-dependent plasticity, and efficient motor control.

  20. Relationship between static foot posture and foot mobility

    Directory of Open Access Journals (Sweden)

    McPoil Thomas G

    2011-01-01

    Full Text Available Abstract Background It is not uncommon for a person's foot posture and/or mobility to be assessed during a clinical examination. The exact relationship, however, between static posture and mobility is not known. Objective The purpose of this study was to determine the degree of association between static foot posture and mobility. Method The static foot posture and foot mobility of 203 healthy individuals was assessed and then analyzed to determine if low arched or "pronated" feet are more mobile than high arched or "supinated" feet. Results The study demonstrated that those individuals with a lower standing dorsal arch height and/or a wider standing midfoot width had greater mobility in their foot. In addition, those individuals with higher Foot Posture Index (FPI values demonstrated greater mobility and those with lower FPI values demonstrated less mobility. Finally, the amount of foot mobility that an individual has can be predicted reasonably well using either a 3 or 4 variable linear regression model. Conclusions Because of the relationship between static foot posture and mobility, it is recommended that both be assessed as part of a comprehensive evaluation of a individual with foot problems.

  1. Animal diversity and ecosystem functioning in dynamic food webs

    Science.gov (United States)

    Schneider, Florian D.; Brose, Ulrich; Rall, Björn C.; Guill, Christian

    2016-10-01

    Species diversity is changing globally and locally, but the complexity of ecological communities hampers a general understanding of the consequences of animal species loss on ecosystem functioning. High animal diversity increases complementarity of herbivores but also increases feeding rates within the consumer guild. Depending on the balance of these counteracting mechanisms, species-rich animal communities may put plants under top-down control or may release them from grazing pressure. Using a dynamic food-web model with body-mass constraints, we simulate ecosystem functions of 20,000 communities of varying animal diversity. We show that diverse animal communities accumulate more biomass and are more exploitative on plants, despite their higher rates of intra-guild predation. However, they do not reduce plant biomass because the communities are composed of larger, and thus energetically more efficient, plant and animal species. This plasticity of community body-size structure reconciles the debate on the consequences of animal species loss for primary productivity.

  2. Functional diversity and evolutionary dynamics of thermoTRP channels.

    Science.gov (United States)

    Saito, Shigeru; Tominaga, Makoto

    2015-03-01

    Animals have evolved sophisticated physiological systems for sensing ambient temperature since changes in environmental temperatures affect various biological processes. Thermosensitive transient receptor potential (thermoTRP) channels serve as thermal sensors in diverse animal species. They are multimodal receptors that are activated by temperature as well as other physical and chemical stimuli. Since thermoTRP channels are calcium permeable non-selective cation channels, their activation leads to an influx of calcium and sodium ions into the cell and triggers downstream signal transduction. ThermoTRP channels have been characterized in diverse animal species over the past several years, illuminating the diversification of thermoTRP channels in the course of evolution. The gene repertoires of thermoTRP channels differ among animal species. Additionally, in some cases, the temperature and chemical sensitivities among orthologous thermoTRP channels vary among species. The evolutionary flexibility of thermoTRP channels enabled them to contribute to unique physiological systems such as infrared sensation in snakes and bats and seasonal adaptation in silk moth. On the other hand, the functional differences of thermoTRP channels among species have been utilized for understanding the molecular basis for their activation (or inhibition) mechanisms, and amino acid residues (or domains) responsible for the respective channel properties have been identified in various thermoTRP channels. Here we summarize the current understanding of the functional diversity and evolutionary dynamics of thermoTRP channels.

  3. Green’s function molecular dynamics meets discrete dislocation plasticity

    Science.gov (United States)

    Venugopalan, Syam P.; Müser, Martin H.; Nicola, Lucia

    2017-09-01

    Metals deform plastically at the asperity level when brought in contact with a counter body even when the nominal contact pressure is small. Modeling the plasticity of solids with rough surfaces is challenging due to the multi-scale nature of surface roughness and the length-scale dependence of plasticity. While discrete-dislocation plasticity (DDP) simulations capture size-dependent plasticity by keeping track of the motion of individual dislocations, only simple two-dimensional surface geometries have so far been studied with DDP. The main computational bottleneck in contact problems modeled by DDP is the calculation of the dislocation image fields. We address this issue by combining two-dimensional DDP with Green’s function molecular dynamics. The resulting method allows for an efficient boundary-value-method based treatment of elasticity in the presence of dislocations. We demonstrate that our method captures plasticity quantitatively from single to many dislocations and that it scales more favorably with system size than conventional methods. We also derive the relevant Green’s functions for elastic slabs of finite width allowing arbitrary boundary conditions on top and bottom surface to be simulated.

  4. Quantification of functional dynamics of membrane proteins reconstituted in nanodiscs membranes by single turnover functional readout

    DEFF Research Database (Denmark)

    Moses, Matias Emil; Hedegård, Per; Hatzakis, Nikos

    2016-01-01

    and quantification of the activity, abundance, and lifetime of multiple states and transient intermediates in the energy landscape that are typically averaged out in nonsynchronized ensemble measurements. Studying the function of membrane proteins at the single-molecule level remains a formidable challenge......, and to date there is limited number of available functional assays. In this chapter, we describe in detail our recently developed methodology to reconstitute membrane proteins such as the integral membrane protein cytochrome P450 oxidoreductase on membrane systems such as Nanodiscs and study their functional...... dynamics by recordings at the fundamental resolution of individual catalytic turnovers using prefluorescent substrate analogues. We initially describe the methodology for reconstitution, surface immobilization, and data acquisition of individual enzyme catalytic turnovers. We then explain in detail...

  5. A Frame Work for Frequent Pattern Mining Using Dynamic Function

    Directory of Open Access Journals (Sweden)

    Sunil Joshi

    2011-05-01

    Full Text Available Discovering frequent objects (item sets, sequential patterns is one of the most vital fields in data mining. It is well understood that it require running time and memory for defining candidates and this is the motivation for developing large number of algorithm. Frequent patterns mining is the paying attention research issue in association rules analysis. Apriori algorithm is a standard algorithm of association rules mining. Plenty of algorithms for mining association rules and their mutations are projected on the foundation of Apriori Algorithm. Most of the earlier studies adopted Apriori-like algorithms which are based on generate-and-test candidates theme and improving algorithm approach and formation but no one give attention to the structure of database. Several modifications on apriori algorithms are focused on algorithm Strategy but no one-algorithm emphasis on least transaction and more attribute representation of database. We presented a new research trend on frequent pattern mining in which generate Transaction pair to lighten current methods from the traditional blockage, providing scalability to massive data sets and improving response time. In order to mine patterns in database with more columns than rows, we proposed a complete framework for the frequent pattern mining. A simple approach is if we generate pair of transaction instead of item id where attributes are much larger then transaction so result is very fast. Newly, different works anticipated a new way to mine patterns in transposed databases where there is a database with thousands of attributes but merely tens of stuff. We suggest a novel dynamic algorithm for frequent pattern mining in which generate transaction pair and for generating frequent pattern we find out by longest common subsequence using dynamic function. Our solutions give result more rapidly. A quantitative investigation of these tradeoffs is conducted through a wide investigational study on artificial and

  6. Foot segment kinematics during normal walking using a multisegment model of the foot and ankle complex.

    Science.gov (United States)

    Jenkyn, Thomas R; Anas, Kiersten; Nichol, Alexander

    2009-03-01

    Gait analysis using optical tracking equipment has been demonstrated to be a clinically useful tool for measuring three-dimensional kinematics and kinetics of the human body. However, in current practice, the foot is treated as a single rigid segment that articulates with the lower leg, meaning the motions of the joints of the foot cannot be measured. A multisegment kinematic model of the foot was developed for use in a gait analysis laboratory. The foot was divided into hindfoot, talus, midfoot, and medial and lateral forefoot segments. Six functional joints were defined: Ankle and subtalar joints, frontal and transverse plane motions of the hindfoot relative to midfoot, supination-pronation twist of the forefoot relative to midfoot, and medial longitudinal arch height-to-length ratio. Twelve asymptomatic subjects were tested during barefoot walking with a six-camera optical stereometric system and passive markers organized in triads. Repeatability of reported motions was tested using coefficients of multiple correlation. Ankle and subtalar joint motions and twisting of the forefoot were most repeatable. Hindfoot motions were least repeatable both within subjects and between subjects. Hindfoot and forefoot pronations in the frontal place were found to coincide with dropping of the medial longitudinal arch between early to midstance, followed by supination and rising of the arch in late stance and swing phase. This multisegment foot model overcomes a major shortcoming in current gait analysis practice-the inability to measure motion within the foot. Such measurements are crucial if gait analysis is to remain relevant in orthopaedic and rehabilitative treatment of the foot and ankle.

  7. Leaf and stem economics spectra drive diversity of functional plant traits in a dynamic global vegetation model

    NARCIS (Netherlands)

    Sakschewski, B.; Bloh, von W.; Boit, A.; Rammig, A.; Kattge, J.; Poorter, L.; Peñualeas, J.; Thonicke, K.

    2015-01-01

    Functional diversity is critical for ecosystem dynamics, stability and productivity. However, dynamic global vegetation models (DGVMs) which are increasingly used to simulate ecosystem functions under global change, condense functional diversity to plant functional types (PFTs) with constant paramet

  8. [Neuropad test in evaluation of diabetic foot].

    Science.gov (United States)

    Vieru, Alexandra; Niţă, Otilia; Graur, Lidia Iuliana; Mazilu, Georgiana; Mihalache, Laura; Popescu, Raluca Maria; Graur, Mariana

    2012-01-01

    Diabetic neuropathy (DN) is the main cause of foot ulceration. One of the earliest modifications is the loss of normal sudomotor function, a sign of autonomic neuropathy. The aim of this study is to evaluate sudomotor dysfunction using a new tool (Neuropad) in diabetic patients with foot ulceration. We included 58 diabetic patients with foot ulceration admitted in 2010 in the Clinical Center for Diabetes, Nutrition and Metabolic Diseases. We collected data regarding age, gender, type and duration of diabetes, glycated hemoglobin (HbAlc), history of amputations and duration of hospital admission. Peripheral neuropathy was evaluated through the Neuropathy Disability Score (NDS) and autonomic neuropathy was tested through Neuropad. 95% of patients had NDS > or = 6, among which 76% had also positive Neuropad test. Patients with both peripheral and autonomic neuropathy had longer duration of diabetes (p = 0.027) but similar HbA1c as patients with only peripheral neuropathy (p = 0.09). The former also had longer duration of current admission (p = 0.022) and a higher percentage of these patients had history of amputations (p = 0.041). Neuropad is a reliable, easy to use test for the diagnosis of autonomic neuropathy, which puts patients at greater risk for foot ulceration and amputation.

  9. Ultrasound of ankle and foot: overuse and sports injuries.

    Science.gov (United States)

    Khoury, Viviane; Guillin, Raphaël; Dhanju, Jag; Cardinal, Etienne

    2007-06-01

    Sports and overuse injuries of the ankle and foot are commonly encountered in clinical practice. Ultrasound (US) has been established as an excellent diagnostic modality for foot and ankle injuries, providing a rapid noninvasive, economical, and readily available tool that is well tolerated by the patient with acute or chronic pain. The opportunity for dynamic examination is another advantage of US in evaluating ankle and foot pathology, where maneuvers such as muscle contraction and stressing of the joint may be particularly helpful. In many cases, US can be used as a first-line and only imaging modality for diagnosis. This article focuses on ankle disorders related to sports or overuse that affect tendons, including tendinosis, tenosynovitis, paratendinitis, rupture, dislocation, and ligaments that are commonly torn. The sonographic features of certain common foot disorders related to physical activity and overuse are also discussed, including plantar fasciitis, Morton's neuroma, stress fractures, and plantar plate injury.

  10. Fast dynamics perturbation analysis for prediction of protein functional sites

    Directory of Open Access Journals (Sweden)

    Cohn Judith D

    2008-01-01

    Full Text Available Abstract Background We present a fast version of the dynamics perturbation analysis (DPA algorithm to predict functional sites in protein structures. The original DPA algorithm finds regions in proteins where interactions cause a large change in the protein conformational distribution, as measured using the relative entropy Dx. Such regions are associated with functional sites. Results The Fast DPA algorithm, which accelerates DPA calculations, is motivated by an empirical observation that Dx in a normal-modes model is highly correlated with an entropic term that only depends on the eigenvalues of the normal modes. The eigenvalues are accurately estimated using first-order perturbation theory, resulting in a N-fold reduction in the overall computational requirements of the algorithm, where N is the number of residues in the protein. The performance of the original and Fast DPA algorithms was compared using protein structures from a standard small-molecule docking test set. For nominal implementations of each algorithm, top-ranked Fast DPA predictions overlapped the true binding site 94% of the time, compared to 87% of the time for original DPA. In addition, per-protein recall statistics (fraction of binding-site residues that are among predicted residues were slightly better for Fast DPA. On the other hand, per-protein precision statistics (fraction of predicted residues that are among binding-site residues were slightly better using original DPA. Overall, the performance of Fast DPA in predicting ligand-binding-site residues was comparable to that of the original DPA algorithm. Conclusion Compared to the original DPA algorithm, the decreased run time with comparable performance makes Fast DPA well-suited for implementation on a web server and for high-throughput analysis.

  11. Boltzmann-conserving classical dynamics in quantum time-correlation functions: Matsubara dynamics

    CERN Document Server

    Hele, Timothy J H; Muolo, Andrea; Althorpe, Stuart C

    2015-01-01

    We show that a single change in the derivation of the linearized semiclassical-initial value representation (LSC-IVR or classical Wigner approximation) results in a classical dynamics which conserves the quantum Boltzmann distribution. We rederive the (standard) LSC-IVR approach by writing the (exact) quantum time-correlation function in terms of the normal modes of a free ring-polymer (i.e. a discrete imaginary-time Feynman path), taking the limit that the number of polymer beads $N \\to \\infty$, such that the lowest normal-mode frequencies take their Matsubara values. The change we propose is to truncate the quantum Liouvillian, not explicitly in powers of $\\hbar^2$ at $\\hbar^0$ (which gives back the standard LSC-IVR approximation), but in the normal-mode derivatives corresponding to the lowest Matsubara frequencies. The resulting Matsubara dynamics is inherently classical (since all terms $\\mathcal{O}\\left(\\hbar^{2}\\right)$ disappear from the Matsubara Liouvillian in the limit $N \\to \\infty$), and conserves...

  12. A lagrangian dynamical theory for the mass function of cosmic structures; 1, dynamics

    CERN Document Server

    Monaco, P

    1996-01-01

    A new theory for determining the mass function of cosmic structures is presented. It relies on a realistic treatment of collapse dynamics. Gravitational collapse is analyzed in the Lagrangian perturbative framework. Lagrangian perturbations provide an approximation of truncated type, i.e. small-scale structure is filtered out. The collapse time is suitably defined as the instant at which orbit crossing takes place. The convergence of the Lagrangian series in predicting the collapse time of a homogeneous ellipsoid is demonstrated; it is also shown that third-order calculations are necessary in predicting collapse. Then, the Lagrangian prediction, with a correction for quasi-spherical perturbations, can be used to determine the collapse time of a homogeneous ellipsoid in a very fast and precise way. Furthermore, ellipsoidal collapse can be considered as a particular truncation of the Lagrangian series. Gaussian fields with scale-free power spectra are then considered. The Lagrangian series for the collapse time...

  13. American Orthopaedic Foot and Ankle Society

    Science.gov (United States)

    ... Statements Publications Foot & Ankle International (FAI) Foot & Ankle Orthopaedics (FAO) In~Stride Newsletter News Center Press Releases ... the best possible care, see a foot & ankle ORTHOPAEDIC surgeon. Find one in your area here. Having ...

  14. Dynamic behavior of chemical reactivity indices in density functional theory: A Bohn-Oppenheimer quantum molecular dynamics study

    Indian Academy of Sciences (India)

    Shubin Liu

    2005-09-01

    Dynamic behaviors of chemical concepts in density functional theory such as frontier orbitals (HOMO/LUMO), chemical potential, hardness, and electrophilicity index have been investigated in this work in the context of Bohn-Oppenheimer quantum molecular dynamics in association with molecular conformation changes. Exemplary molecular systems like CH$^{+}_{5}$ , Cl- (H2O)30 and Ca2+ (H2O)15 are studied at 300 K in the gas phase, demonstrating that HOMO is more dynamic than LUMO, chemical potential and hardness often fluctuate concurrently. It is argued that DFT concepts and indices may serve as a good framework to understand molecular conformation changes as well as other dynamic phenomena.

  15. Foot-and-mouth disease

    DEFF Research Database (Denmark)

    Belsham, Graham; Charleston, Bryan; Jackson, Terry

    2009-01-01

    Foot-and-mouth disease is an economically important, highly contagious, disease of cloven-hoofed animals characterized by the appearance of vesicles (blisters) on the feet and in and around the mouth. The causative agent, foot-and-mouth disease virus, was the first mammalian virus to be discovered...

  16. Sesamoid Injuries in the Foot

    Science.gov (United States)

    ... the shoe may be prescribed for long-term treatment of sesamoiditis to balance the pressure placed on the ball of the foot. When Is Surgery Needed? When sesamoid injuries fail to respond to nonsurgical treatment, surgery may be required. The foot and ankle ...

  17. Malignant Melanoma of the Foot

    Science.gov (United States)

    ... page. Please enable Javascript in your browser. Malignant Melanoma of the Foot What Is Malignant Melanoma? Melanoma is a cancer that begins in the ... people of all age groups, even the young. Melanoma in the Foot Melanoma that occurs in the ...

  18. Foot-and-mouth disease

    DEFF Research Database (Denmark)

    Belsham, Graham; Charleston, Bryan; Jackson, Terry;

    2009-01-01

    Foot-and-mouth disease is an economically important, highly contagious, disease of cloven-hoofed animals characterized by the appearance of vesicles (blisters) on the feet and in and around the mouth. The causative agent, foot-and-mouth disease virus, was the first mammalian virus to be discovered...

  19. Contribution of the transverse arch to foot stiffness in humans

    OpenAIRE

    Yawar, Ali; Korpas, Lucia; Lugo-Bolanos, Maria; Mandre, Shreyas; Venkadesan, Madhusudhan

    2017-01-01

    Stiffness of the human foot is central to its mechanical function, such as elastic energy storage and propulsion. Its doubly-arched structure, manifested as longitudinal and transverse arches, is thought to underlie the stiff nature. However, previous studies have focused solely on the longitudinal arch, and little is known about whether and how the transverse arch impacts the foot's stiffness. The common observation that a flexible currency bill significantly stiffens upon curling it transve...

  20. Identification of Foot Pathologies Based on Plantar Pressure Asymmetry

    OpenAIRE

    Linah Wafai; Aladin Zayegh; John Woulfe; Syed Mahfuzul Aziz; Rezaul Begg

    2015-01-01

    Foot pathologies can negatively influence foot function, consequently impairing gait during daily activity, and severely impacting an individual’s quality of life. These pathologies are often painful and correspond with high or abnormal plantar pressure, which can result in asymmetry in the pressure distribution between the two feet. There is currently no general consensus on the presence of asymmetry in able-bodied gait, and plantar pressure analysis during gait is in dire need of a standar...

  1. Reconstruction of foot flexion-extension function after replantation of amputated leg%小腿中段离断再植后重建足跖屈背伸功能

    Institute of Scientific and Technical Information of China (English)

    陈秋生; 余斌; 杨建成; 江浩; 陈霞; 竺筠雯

    2001-01-01

    Objective To investigate the foot function reconstruction after replantation of amputated leg. Methods The n erveless injury muscle in the amputated limbs was cut off, a section tensor fascia lata was resected off to replace the injured muscle. Meanwhile, transfer biceps femoris muscle and sartoriu s muscle to strengthen extensive muscles, and transfer semimembranosus muscle an d gracilis muscle to strengthen flexion muscles. Postoperation functional exer cises of the ankle was carried out. Results 2 patients were tre ated with this t echnique, followed up for more than 2 years. The extension and flexion muscle st rength reached MRC4 with satisfactory ankle function, the range of motion of ank le was restored nearly to normal. Conclusion The technique is e ffective to reconstruct most functions of the normal muscles and restore foot function.%目的 探讨小腿中段离断再植后足跖屈背伸功能重建的方法 。方法 常规断肢再植,术中将离断肢远段失神经支配的肌组织切除,只 保留肌腱及肌腱膜,切取髂胫束条桥接远端背伸肌腱和近端肌腹,同时和前移缝匠肌、股二 头肌长头缝接,加强足背伸肌力;桥接远端跖屈肌腱和近端肌腹,同时和游离的半腱肌、股 薄肌缝接,加强足跖屈肌力。结果 治疗2例,分别随访2年8个月及2年5个 月,足背伸、跖屈肌力达Ⅳ~Ⅳ+,踝关节活动度近正常。结论 应用髂 胫束条桥接远断端的肌腱和近断端的正常肌组织,同时利用缝匠肌、股二头肌、半腱肌、股 薄肌加强足的背伸、跖屈肌力,是一种有效的功能重建方法。

  2. Diabetes Foot Ulcers: A novel Treatment Strategy

    Directory of Open Access Journals (Sweden)

    Golnaz Namazi

    2008-05-01

    Full Text Available Foot ulcers are common in 12-25 percent of diabetic patients. Preventing, controlling and treating of these kind chronic wounds are of the major clinical challenges.Evidence based documents revealed that DFU (Diabetic Foot ulcer is a chronic wound type originating from disturbed cellular and molecular mechanisms that have to be in its functional form to overcome its problem. In diabetes and some other chronic based diseases, harmonized acting machine causes chronic phases that result in conditions as foot ulceration and related complications seen commonly in diabetes.DFU needs to be transformed into acute phase in order to be healed in a physiological manner. Disturbed mechanisms have to be corrected reversely and to achieve such a goal it is essential to better understanding of disturbing factors responsible for biological abnormalities. Factors associated with DFU are as cellular and molecular recruitment and function impairments and there is need to repair these mechanisms. For this, we believe that the activated Th-1 cells (T helper-1 Cells might have a critical role in regulation of the several effector functions of the cellular and molecular mechanisms essential to the body to act the best. Evidences and our successful results urge us to suggest this regulatory role for effector cells and molecules generated through activation of Th-1 cells as a treatment strategy.

  3. Dynamic heart phantom with functional mitral and aortic valves

    Science.gov (United States)

    Vannelli, Claire; Moore, John; McLeod, Jonathan; Ceh, Dennis; Peters, Terry

    2015-03-01

    Cardiac valvular stenosis, prolapse and regurgitation are increasingly common conditions, particularly in an elderly population with limited potential for on-pump cardiac surgery. NeoChord©, MitraClipand numerous stent-based transcatheter aortic valve implantation (TAVI) devices provide an alternative to intrusive cardiac operations; performed while the heart is beating, these procedures require surgeons and cardiologists to learn new image-guidance based techniques. Developing these visual aids and protocols is a challenging task that benefits from sophisticated simulators. Existing models lack features needed to simulate off-pump valvular procedures: functional, dynamic valves, apical and vascular access, and user flexibility for different activation patterns such as variable heart rates and rapid pacing. We present a left ventricle phantom with these characteristics. The phantom can be used to simulate valvular repair and replacement procedures with magnetic tracking, augmented reality, fluoroscopy and ultrasound guidance. This tool serves as a platform to develop image-guidance and image processing techniques required for a range of minimally invasive cardiac interventions. The phantom mimics in vivo mitral and aortic valve motion, permitting realistic ultrasound images of these components to be acquired. It also has a physiological realistic left ventricular ejection fraction of 50%. Given its realistic imaging properties and non-biodegradable composition—silicone for tissue, water for blood—the system promises to reduce the number of animal trials required to develop image guidance applications for valvular repair and replacement. The phantom has been used in validation studies for both TAVI image-guidance techniques1, and image-based mitral valve tracking algorithms2.

  4. Abstraction of Continuous Dynamical Systems Utilizing Lyapunov Functions

    DEFF Research Database (Denmark)

    Sloth, Christoffer; Wisniewski, Rafal

    2010-01-01

    This paper considers the development of a method for abstracting continuous dynamical systems by timed automata. The method is based on partitioning the state space of dynamical systems with invariant sets, which form cells representing locations of the timed automata. To enable verification of t...

  5. Estimation of Response Functions Based on Variational Bayes Algorithm in Dynamic Images Sequences

    Directory of Open Access Journals (Sweden)

    Bowei Shan

    2016-01-01

    Full Text Available We proposed a nonparametric Bayesian model based on variational Bayes algorithm to estimate the response functions in dynamic medical imaging. In dynamic renal scintigraphy, the impulse response or retention functions are rather complicated and finding a suitable parametric form is problematic. In this paper, we estimated the response functions using nonparametric Bayesian priors. These priors were designed to favor desirable properties of the functions, such as sparsity or smoothness. These assumptions were used within hierarchical priors of the variational Bayes algorithm. We performed our algorithm on the real online dataset of dynamic renal scintigraphy. The results demonstrated that this algorithm improved the estimation of response functions with nonparametric priors.

  6. Optimization of prosthetic foot stiffness to reduce metabolic cost and intact knee loading during below-knee amputee walking: a theoretical study.

    Science.gov (United States)

    Fey, Nicholas P; Klute, Glenn K; Neptune, Richard R

    2012-11-01

    Unilateral below-knee amputees develop abnormal gait characteristics that include bilateral asymmetries and an elevated metabolic cost relative to non-amputees. In addition, long-term prosthesis use has been linked to an increased prevalence of joint pain and osteoarthritis in the intact leg knee. To improve amputee mobility, prosthetic feet that utilize elastic energy storage and return (ESAR) have been designed, which perform important biomechanical functions such as providing body support and forward propulsion. However, the prescription of appropriate design characteristics (e.g., stiffness) is not well-defined since its influence on foot function and important in vivo biomechanical quantities such as metabolic cost and joint loading remain unclear. The design of feet that improve these quantities could provide considerable advancements in amputee care. Therefore, the purpose of this study was to couple design optimization with dynamic simulations of amputee walking to identify the optimal foot stiffness that minimizes metabolic cost and intact knee joint loading. A musculoskeletal model and distributed stiffness ESAR prosthetic foot model were developed to generate muscle-actuated forward dynamics simulations of amputee walking. Dynamic optimization was used to solve for the optimal muscle excitation patterns and foot stiffness profile that produced simulations that tracked experimental amputee walking data while minimizing metabolic cost and intact leg internal knee contact forces. Muscle and foot function were evaluated by calculating their contributions to the important walking subtasks of body support, forward propulsion and leg swing. The analyses showed that altering a nominal prosthetic foot stiffness distribution by stiffening the toe and mid-foot while making the ankle and heel less stiff improved ESAR foot performance by offloading the intact knee during early to mid-stance of the intact leg and reducing metabolic cost. The optimal design also

  7. Stiffness of the human foot and evolution of the transverse arch

    OpenAIRE

    Venkadesan, Madhusudhan; Dias, Marcelo A.; Singh, Dhiraj K.; Bandi, Mahesh M.; Mandre, Shreyas

    2017-01-01

    Foot stiffness underlies its mechanical function, and is central to the evolution of human bipedal locomotion. The stiff and propulsive human foot has two distinct arches, the longitudinal and transverse. By contrast, the feet of non-human primates are flat and softer. Current understanding of foot stiffness is based on studies that focus solely on the longitudinal arch, and little is known about the mechanical function of the transverse arch. However, common experience suggests that transver...

  8. Biomechanical consequences of gait impairment at the ankle and foot : Injury, malalignment, and co-contraction

    OpenAIRE

    Wang, Ruoli

    2012-01-01

    The human foot contributes significantly to the function of the whole lower extremity during standing and locomotion. Nevertheless, the foot and ankle often suffer injuries and are affected by many musculoskeletal and neurological pathologies. The overall aim of this thesis was to evaluate gait parameters and muscle function change due to foot and ankle injury, malalignment and co-contraction. Using 3D gait analysis, analytical analyses and computational simulations, biomechanical consequence...

  9. Relationships between static foot alignment and dynamic plantar loads in runners with acute and chronic stages of plantar fasciitis: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Ana P. Ribeiro

    2016-02-01

    Full Text Available BACKGROUND: The risk factors for the development of plantar fasciitis (PF have been associated with the medial longitudinal arch (MLA, rearfoot alignment and calcaneal overload. However, the relationships between the biomechanical variables have yet to be determined. OBJECTIVE: The goal of this study was to investigate the relationships between the MLA, rearfoot alignment, and dynamic plantar loads in runners with unilateral PF in acute and chronic phases. METHOD: Cross-sectional study which thirty-five runners with unilateral PF were evaluated: 20 in the acute phase (with pain and 15 with previous chronic PF (without pain. The MLA index and rearfoot alignment were calculated using digital images. The contact area, maximum force, peak pressure, and force-time integral over three plantar areas were acquired with Pedar X insoles while running at 12 km/h, and the loading rates were calculated from the vertical forces. RESULTS: The multiple regression analyses indicated that both the force-time integral (R2=0.15 for acute phase PF; R2=0.17 for chronic PF and maximum force (R2=0.35 for chronic PF over the forefoot were predicted by an elevated MLA index. The rearfoot valgus alignment predicted the maximum force over the rearfoot in both PF groups: acute (R2=0.18 and chronic (R2=0.45. The rearfoot valgus alignment also predicted higher loading rates in the PF groups: acute (R2=0.19 and chronic (R2=0.40. CONCLUSION: The MLA index and the rearfoot alignment were good predictors of plantar loads over the forefoot and rearfoot areas in runners with PF. However, rearfoot valgus was demonstrated to be an important clinical measure, since it was able to predict the maximum force and both loading rates over the rearfoot.

  10. Relationships between static foot alignment and dynamic plantar loads in runners with acute and chronic stages of plantar fasciitis: a cross-sectional study

    Science.gov (United States)

    Ribeiro, Ana P.; Sacco, Isabel C. N.; Dinato, Roberto C.; João, Silvia M. A.

    2016-01-01

    BACKGROUND: The risk factors for the development of plantar fasciitis (PF) have been associated with the medial longitudinal arch (MLA), rearfoot alignment and calcaneal overload. However, the relationships between the biomechanical variables have yet to be determined. OBJECTIVE: The goal of this study was to investigate the relationships between the MLA, rearfoot alignment, and dynamic plantar loads in runners with unilateral PF in acute and chronic phases. METHOD: Cross-sectional study which thirty-five runners with unilateral PF were evaluated: 20 in the acute phase (with pain) and 15 with previous chronic PF (without pain). The MLA index and rearfoot alignment were calculated using digital images. The contact area, maximum force, peak pressure, and force-time integral over three plantar areas were acquired with Pedar X insoles while running at 12 km/h, and the loading rates were calculated from the vertical forces. RESULTS: The multiple regression analyses indicated that both the force-time integral (R 2=0.15 for acute phase PF; R 2=0.17 for chronic PF) and maximum force (R 2=0.35 for chronic PF) over the forefoot were predicted by an elevated MLA index. The rearfoot valgus alignment predicted the maximum force over the rearfoot in both PF groups: acute (R 2=0.18) and chronic (R 2=0.45). The rearfoot valgus alignment also predicted higher loading rates in the PF groups: acute (R 2=0.19) and chronic (R 2=0.40). CONCLUSION: The MLA index and the rearfoot alignment were good predictors of plantar loads over the forefoot and rearfoot areas in runners with PF. However, rearfoot valgus was demonstrated to be an important clinical measure, since it was able to predict the maximum force and both loading rates over the rearfoot. PMID:26786073

  11. Foot Morphological Difference between Habitually Shod and Unshod Runners.

    Directory of Open Access Journals (Sweden)

    Yang Shu

    Full Text Available Foot morphology and function has received increasing attention from both biomechanics researchers and footwear manufacturers. In this study, 168 habitually unshod runners (90 males whose age, weight & height were 23±2.4 years, 66±7.1 kg & 1.68±0.13 m and 78 females whose age, weight & height were 22±1.8 years, 55±4.7 kg & 1.6±0.11 m (Indians and 196 shod runners (130 males whose age, weight & height were 24±2.6 years, 66±8.2 kg & 1.72±0.18 m and 66 females whose age, weight & height were 23±1.5 years, 54±5.6 kg & 1.62±0.15 m (Chinese participated in a foot scanning test using the easy-foot-scan (a three-dimensional foot scanning system to obtain 3D foot surface data and 2D footprint imaging. Foot length, foot width, hallux angle and minimal distance from hallux to second toe were calculated to analyze foot morphological differences. This study found that significant differences exist between groups (shod Chinese and unshod Indians for foot length (female p = 0.001, width (female p = 0.001, hallux angle (male and female p = 0.001 and the minimal distance (male and female p = 0.001 from hallux to second toe. This study suggests that significant differences in morphology between different ethnicities could be considered for future investigation of locomotion biomechanics characteristics between ethnicities and inform last shape and design so as to reduce injury risks and poor performance from mal-fit shoes.

  12. NONLINEAR MHD WAVES IN A PROMINENCE FOOT

    Energy Technology Data Exchange (ETDEWEB)

    Ofman, L. [Catholic University of America, Washington, DC 20064 (United States); Knizhnik, K.; Kucera, T. [NASA Goddard Space Flight Center, Code 671, Greenbelt, MD 20771 (United States); Schmieder, B. [LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, Univ. Paris-Diderot, Sorbonne Paris Cit, 5 place Jules Janssen, F-92195 Meudon (France)

    2015-11-10

    We study nonlinear waves in a prominence foot using a 2.5D MHD model motivated by recent high-resolution observations with Hinode/Solar Optical Telescope in Ca ii emission of a prominence on 2012 October 10 showing highly dynamic small-scale motions in the prominence material. Observations of Hα intensities and of Doppler shifts show similar propagating fluctuations. However, the optically thick nature of the emission lines inhibits a unique quantitative interpretation in terms of density. Nevertheless, we find evidence of nonlinear wave activity in the prominence foot by examining the relative magnitude of the fluctuation intensity (δI/I ∼ δn/n). The waves are evident as significant density fluctuations that vary with height and apparently travel upward from the chromosphere into the prominence material with quasi-periodic fluctuations with a typical period in the range of 5–11 minutes and wavelengths <2000 km. Recent Doppler shift observations show the transverse displacement of the propagating waves. The magnetic field was measured with the THEMIS instrument and was found to be 5–14 G. For the typical prominence density the corresponding fast magnetosonic speed is ∼20 km s{sup −1}, in qualitative agreement with the propagation speed of the detected waves. The 2.5D MHD numerical model is constrained with the typical parameters of the prominence waves seen in observations. Our numerical results reproduce the nonlinear fast magnetosonic waves and provide strong support for the presence of these waves in the prominence foot. We also explore gravitational MHD oscillations of the heavy prominence foot material supported by dipped magnetic field structure.

  13. Dynamics of homegarden structure and function in Kerala, India

    NARCIS (Netherlands)

    Peyre, A.; Guidal, A.; Wiersum, K.F.; Bongers, F.J.J.M.

    2006-01-01

    Homegardens in Kerala have long been important multi-purpose agroforestry systems that combine ecological and socioeconomical sustainability. However, traditional homegardens are subject to different conversion processes linked to socioeconomic changes. These dynamics were studied in a survey of 30

  14. Dynamical model for biological functions of DNA molecules

    Institute of Scientific and Technical Information of China (English)

    PANGXiao-fengI; YANGYao

    2004-01-01

    We proposed a dynamic model of DNA to study its nonlinear excitation and duplication and transcription in the basis of molecular structure and changes of conformation of DNA under influence of bioenergy.

  15. Preliminary report: Dynamic stereopsis in patients with impaired binocular function.

    Science.gov (United States)

    Mollenhauer, K A; Haase, W

    2000-12-01

    In this study, 46 strabismic patients aged between 9 and 58 years were tested for dynamic stereopsis in the peripheral visual field with up to 20 degrees eccentricity. Squint angles ranged from +30 to -36 degrees. The effect of surgical realignment of the visual axes on dynamic stereopsis was tested before and after surgery in 40 of these patients. Of the 46 patients, 23 had esotropia and 23 exotropia. A test device was used which presented two projected squares in polarized light (each square being perceived monocularly through a polarization filter) in horizontal motion, thus creating a three-dimensional impression. Patients were tested qualitatively for dynamically stereoactive fields of vision and quantitatively for the threshold value needed to create a three-dimensional impression. We found residual dynamic stereopsis in 30% of patients who had no central static stereopsis. 56% of the patients improved after surgery, either through a significant (p traffic and sports medicine, regardless of the effect on classical tests.

  16. Structural dynamics flexibility informs function and evolution at a proteome scale

    Science.gov (United States)

    Nevin Gerek, Zeynep; Kumar, Sudhir; Banu Ozkan, Sefika

    2013-01-01

    Protein structures are dynamic entities with a myriad of atomic fluctuations, side-chain rotations, and collective domain movements. Although the importance of these dynamics to proper functioning of proteins is emerging in the studies of many protein families, there is a lack of broad evidence for the critical role of protein dynamics in shaping the biological functions of a substantial fraction of residues for a large number of proteins in the human proteome. Here, we propose a novel dynamic flexibility index (dfi) to quantify the dynamic properties of individual residues in any protein and use it to assess the importance of protein dynamics in 100 human proteins. Our analyses involving functionally critical positions, disease-associated and putatively neutral population variations, and the rate of interspecific substitutions per residue produce concordant patterns at a proteome scale. They establish that the preservation of dynamic properties of residues in a protein structure is critical for maintaining the protein/biological function. Therefore, structural dynamics needs to become a major component of the analysis of protein function and evolution. Such analyses will be facilitated by the dfi, which will also enable the integrative use of structural dynamics with evolutionary conservation in genomic medicine as well as functional genomics investigations. PMID:23745135

  17. Health literacy and diabetic foot ulcer healing.

    Science.gov (United States)

    Margolis, David J; Hampton, Michelle; Hoffstad, Ole; Malay, D Scot; Thom, Stephen

    2015-01-01

    The adherence by patients to diabetic foot ulcer therapy is often difficult. The goal of this study was to begin to understand how a patient's health literacy affects their foot ulcer management decisions. Initially using a cross-sectional study design, we evaluated diabetics with foot ulcers within 4 weeks of being asked to participate in a longitudinal study. We assessed health literacy using measures of general health literacy, diabetes health literacy, diabetes self-efficacy, and diabetes numeracy. Individuals enrolled in the study had higher health literacy based on the Short Test of Functional Health Literacy in Adults [33.8 (SD 2.3) versus 27.3 (SD 9.6); p = 0.009] as compared to individuals who previously declined an invitation to enroll in the study. Furthermore, patients with lower Short Test of Functional Health Literacy in Adults scores had larger (p = 0.04) and older (p = 0.125) wounds (markers for poorer prognosis). Other measures of literacy showed similar results. In conclusion, those with diminished health literacy were less likely to enroll in an investigational study and had wounds that were less likely to heal. © 2015 by the Wound Healing Society.

  18. Complications of the diabetic foot.

    Science.gov (United States)

    Kim, Paul J; Steinberg, John S

    2013-12-01

    The diabetic foot is at high risk for complications because of its role in ambulation. Peripheral neuropathy and peripheral vascular disease can lead to chronic foot ulcers, which are at high risk for infection, in part attributable to areas of high pressure caused by lack of tolerance of the soft tissue and bone and joint deformity. If left untreated, infection and ischemia lead to tissue death, culminating in amputation. Treatment strategies include antibiosis, topical therapies, offloading, debridement, and surgery. A multidisciplinary team approach is necessary in the prevention and treatment of complications of the diabetic foot.

  19. Foot abnormalities of wild birds

    Science.gov (United States)

    Herman, C.M.; Locke, L.N.; Clark, G.M.

    1962-01-01

    The various foot abnormalities that occur in birds, including pox, scaly-leg, bumble-foot, ergotism and freezing are reviewed. In addition, our findings at the Patuxent Wildlife Research Center include pox from dove, mockingbird, cowbird, grackle and several species of sparrows. Scaly-leg has been particularly prevalent on icterids. Bumble foot has been observed in a whistling swan and in a group of captive woodcock. Ergotism is reported from a series of captive Canada geese from North Dakota. Several drug treatments recommended by others are presented.

  20. Minimally invasive surgery for diabetic plantar foot ulcerations

    Directory of Open Access Journals (Sweden)

    Caio Nery

    2011-11-01

    Full Text Available Complications of diabetes mellitus constitute the most common indications for hospitalization and non-traumatic amputations in the USA. The most important risk factors for the development of diabetic foot ulcerations include the presence of peripheral neuropathy, vasculopathy, limited joint mobility, and pre-existing foot deformities. In our study, 500 diabetic patients treated for plantar forefoot ulcerations were enrolled in a prospective study from 2000 to 2008 at the Federal University of São Paulo, Brazil. Fifty-two patients in the study met the criteria and underwent surgical treatment consisting of percutaneous Achilles tendon lengthening to treat plantar forefoot ulcerations. The postoperative follow-up demonstrated prevention of recurrent foot ulcerations in 92% of these diabetic patients that maintained an improved foot function. In conclusion, our study supports that identification and treatment of ankle equinus in the diabetic population may potentially lead to decreased patient morbidity, including reduced risk for both reulceration, and potential lower extremity amputation.

  1. Human Behavior Recognition Using Foot Pressure Sensing Shoes

    Science.gov (United States)

    Sugimoto, Chika; Ozaki, Kenji; Ezoe, Ryosuke; Hosaka, Hiroshi; Yamato, Hiroyuki

    To recognize human behavior in unlimited environments, sensing shoes for measuring foot pressure distribution were developed. Seven pressure sensors were installed on an insole, and a measurement module was embedded in the shoe. An analysis for discriminating the user's movements from the foot pressure distribution was examined, considering the movements, walking, running, standing, sitting, going upstairs and downstairs, and cycling. These seven actions were discriminated using feature quantities such as the average, standard deviation, maximum, and difference deviation extracted from the data of three sensors by discriminant analysis. The evaluation results showed highly accurate behavior recognition based on foot pressure at some points. In addition, by canonical discriminant analysis, six discriminant functions which classify the seven actions with an accuracy of 100% were derived by using feature quantities extracted from five sensors. The results confirmed that discriminant analysis can be used for automatically recognizing human behaviors based on foot pressure data.

  2. Reconstructive foot and ankle surgeries in diabetic patients

    Directory of Open Access Journals (Sweden)

    Ajit Kumar Varma

    2011-01-01

    Full Text Available Diabetic foot and ankle deformities are secondary to long-standing diabetes and neglected foot care. The concept of surgical correction for these deformities is quite recent. The primary objective of reconstructive foot and ankle surgery is the reduction of increased plantar pressures, reduction of pain and the restoration of function, stability and proper appearance. Foot and ankle deformities can result in significant disability, loss of life style, employment and even the loss of the lower limb. Therefore, restoration of normal, problem free foot function and activities will have a significant impact on peoples′ lives. Reconstructive surgical procedures are complex and during reconstruction, internal and external fixation devices, including pins, compression screws, staples, and wires, may be used for repair and stabilization. The surgeries performed depend on the type and severity of the condition. Surgery can involve any part of the foot and ankle, and may involve tendon, bone, joint, tissue or skin repair. Corrective surgeries can at times be performed on an outpatient basis with minimally invasive techniques. Recovery time depends on the type of condition being treated.

  3. The van Hove distribution function for brownian hard spheres: dynamical test particle theory and computer simulations for bulk dynamics.

    Science.gov (United States)

    Hopkins, Paul; Fortini, Andrea; Archer, Andrew J; Schmidt, Matthias

    2010-12-14

    We describe a test particle approach based on dynamical density functional theory (DDFT) for studying the correlated time evolution of the particles that constitute a fluid. Our theory provides a means of calculating the van Hove distribution function by treating its self and distinct parts as the two components of a binary fluid mixture, with the "self " component having only one particle, the "distinct" component consisting of all the other particles, and using DDFT to calculate the time evolution of the density profiles for the two components. We apply this approach to a bulk fluid of Brownian hard spheres and compare to results for the van Hove function and the intermediate scattering function from Brownian dynamics computer simulations. We find good agreement at low and intermediate densities using the very simple Ramakrishnan-Yussouff [Phys. Rev. B 19, 2775 (1979)] approximation for the excess free energy functional. Since the DDFT is based on the equilibrium Helmholtz free energy functional, we can probe a free energy landscape that underlies the dynamics. Within the mean-field approximation we find that as the particle density increases, this landscape develops a minimum, while an exact treatment of a model confined situation shows that for an ergodic fluid this landscape should be monotonic. We discuss possible implications for slow, glassy, and arrested dynamics at high densities.

  4. [Three-dimensional analysis of the foot following implantation of a HINTEGRA ankle prosthesis: evaluation with the Heidelberg foot model].

    Science.gov (United States)

    Müller, S; Wolf, S; Döderlein, L

    2006-05-01

    Detailed foot kinematics after total ankle replacement has not yet been investigated. In this study 11 patients with unilateral Hintegra ankle prosthesis were analysed with the Heidelberg Foot Model. This model measures the kinematics of the fore-, mid- and hindfoot in three clinical planes. Moreover, the kinetics of the hip, knee and ankle was captured. A diminished ROM was found in all foot segments investigated. The timing of the kinematics between sound and involved side appeared similar. A limitation in the hindfoot mobility, as experienced after ankle arthrodesis, was not observed. However, a careful hindfoot alignment is essential for optimal foot function, and previous malalignments should be corrected. Concerning the kinetics, the replaced ankle showed a decreased power generation compensated by an increase in power in the ipsilateral knee. For a more detailed evaluation, further studies are required which include pre- and postoperative data and also take into account different types of prostheses.

  5. Students' Conceptions of Function Transformation in a Dynamic Mathematical Environment

    Science.gov (United States)

    Daher, Wajeeh; Anabousy, Ahlam

    2015-01-01

    The study of function transformations helps students understand the function concept which is a basic and main concept in mathematics, but this study is problematic to school students as well as college students, especially when transformations are performed on non-basic functions. The current research tried to facilitate grade 9 students'…

  6. GROUP DYNAMICS AND TEAM FUNCTIONING IN ORGANIZATIONAL CONTEXT

    Directory of Open Access Journals (Sweden)

    Raluca ZOLTAN

    2015-07-01

    Full Text Available In all kind of organization many activities are done by groups and teams. But how are they formed? What factors influence their existence and development? How members of groups and teams are selected? Which are the consequences in organizational context? In order to answer these questions, in the present paper we describe and analyze the main approaches regarding the formation of work groups and work teams (sociometric approach and group dynamics approach, the main factors that affects group dynamics and the FIRO model for evaluation the team members’ needs.

  7. Dynamic modelling of pectin extraction describing yield and functional characteristics

    DEFF Research Database (Denmark)

    Andersen, Nina Marianne; Cognet, T.; Santacoloma, P. A.

    2017-01-01

    A dynamic model of pectin extraction is proposed that describes pectin yield, degree of esterification and intrinsic viscosity. The dynamic model is one dimensional in the peel geometry and includes mass transport of pectin by diffusion and reaction kinetics of hydrolysis, degradation and de-esterification....... The model takes into account the effects of the process conditions such as temperature and acid concentration on extraction kinetics. It is shown that the model describes pectin bulk solution concentration, degree of esterification and intrinsic viscosity in pilot scale extractions from lime peel...

  8. Broken Ankle/Broken Foot

    Science.gov (United States)

    ... so that your doctor can examine your gait. Imaging tests Not all foot and ankle injuries require ... an orthopedic surgeon may need to use pins, plates or screws to maintain proper position of your ...

  9. Avoiding foot complications in diabetes

    African Journals Online (AJOL)

    to pain, heat, cold, pressure and proprioception allows increased callus formation at pressure points. This usually precedes an ulcer. Autonomic neuropathy causes a warm foot with bulging veins ... inadequate individual or family awareness.

  10. Imaging the diabetic foot

    Energy Technology Data Exchange (ETDEWEB)

    Gold, R.H. [Dept. of Radiological Sciences, UCLA School of Medicine, Los Angeles, CA (United States); Tong, D.T.F. [Dept. of Radiological Sciences, UCLA School of Medicine, Los Angeles, CA (United States); Crim, J.R. [Durham Radiology Associates, Durham, NC (United States); Seeger, L.L. [Dept. of Radiological Sciences, UCLA School of Medicine, Los Angeles, CA (United States)

    1995-11-01

    Early and accurate diagnosis of infection or neuropathy of the diabetic foot is the key to successful management. Angiopathy leads to ischemia which, in combination with peripheral neuropathy, predisposes to pedal skin ulceration, the precursor of osteomyelitis. Chronic hyperglycemia promotes production of glycosylated end products which accumulate on endothelial proteins, causing ischemia of the vasa nervorum. When combined with axonal degeneration of the sensory nerves, the result is hypertrophic neuroarthropathy. Should the sympathetic nerve fibers also be damaged, the resultant loss of vasoconstrictive impulses leads to hyperemia and atrophic neuroarthropathy. Plain radiography, although less sensitive than radionuclide, magnetic resonance (MR), and computed tomographic examinations, should be the initial procedure for imaging suspected osteomyelitis in the diabetic patient. If the radiographs are normal but the clinical suspicion of osteomyelitis is strong, a three-phase {sup 99m}Tc-MDP scan or MR imaging is recommended. An equivocal {sup 99m}Tc-MDP scan should be followed by MR imaging. To exclude osteomyelitis at a site of neuroarthropathy, a {sup 111}In white blood cell scan is preferable. To obtain a specimen of bone for bacteriological studies, percutaneous core biopsy is the procedure of choice, with the entrance of the needle well beyond the edge of the subjacent ulcer. (orig.)

  11. Hand, Foot, and Mouth Disease

    Centers for Disease Control (CDC) Podcasts

    2013-08-08

    Hand, foot, and mouth disease is a contagious illness that mainly affects children under five. In this podcast, Dr. Eileen Schneider talks about the symptoms of hand, foot, and mouth disease, how it spreads, and ways to help protect yourself and your children from getting infected with the virus.  Created: 8/8/2013 by National Center for Immunization and Respiratory Diseases (NCIRD).   Date Released: 8/8/2013.

  12. Effect of peroneal electrical stimulation versus an ankle-foot orthosis on obstacle avoidance ability in people with stroke-related foot drop.

    NARCIS (Netherlands)

    Swigchem, R. van; Duijnhoven, H.J.R. van; Boer, J. den; Geurts, A.C.H.; Weerdesteijn, V.G.

    2012-01-01

    BACKGROUND: Walking ability of people with foot drop in the chronic phase after stroke is better with functional electrical stimulation (FES) of the peroneal nerve than without an orthotic device. However, the literature is not conclusive on whether peroneal FES also is better than an ankle-foot ort

  13. Multi-functional stage-scanning fluorescence micro/nanoscope for single-lipid dynamics

    Science.gov (United States)

    Yang, Li-Ling; Hsieh, Chia-Fen; Chang, Yi-Ren; Shen, Jie-Pan; Chang, Yu-Chung; Chou, Chia-Fu

    2012-02-01

    We combine pulsed laser, supercontinuum radiation source and fast single-photon counting peripherals to obtain a multifunctional micro/nano-scope. This provides us with better spatial and temporal resolution to observe fast dynamics. Performing fluorescence correlation spectroscopy for fast dynamics (lipid dynamics in supported lipid bilayers and living cells is our goal. Lipid raft serves as a platform for recruiting signaling components of effective signal transduction. However, the dynamics of sub-200nm rapidly aggregated lipid rafts are still not elucidated in living cells. We here report our recent progress on the construction of this multi-functional stage-scanning fluorescence micro/nanoscope for single-lipid dynamics study.

  14. Nonparametric modeling of dynamic functional connectivity in fmri data

    DEFF Research Database (Denmark)

    Nielsen, Søren Føns Vind; Madsen, Kristoffer H.; Røge, Rasmus

    2015-01-01

    in Bayesian statistical modeling we use the predictive likelihood to investigate if the model can discriminate between a motor task and rest both within and across subjects. We further investigate what drives dynamic states using the model on the entire data collated across subjects and task/rest. We find...

  15. Simultaneous dynamic electrical and structural measurements of functional materials

    Energy Technology Data Exchange (ETDEWEB)

    Vecchini, C.; Stewart, M.; Muñiz-Piniella, A.; Wooldridge, J. [National Physical Laboratory, Hampton Road, Teddington TW11 0LW (United Kingdom); Thompson, P.; McMitchell, S. R. C.; Bouchenoire, L.; Brown, S.; Wermeille, D.; Lucas, C. A. [XMaS, The UK-CRG, ESRF-The European Synchrotron, CS40220, F-38043, Grenoble Cedex 09 (France); Department of Physics, University of Liverpool, Liverpool L69 3BX (United Kingdom); Lepadatu, S. [National Physical Laboratory, Hampton Road, Teddington TW11 0LW (United Kingdom); Jeremiah Horrocks Institute, University of Central Lancashire, Preston PR1 2HE (United Kingdom); Bikondoa, O.; Hase, T. P. A. [XMaS, The UK-CRG, ESRF-The European Synchrotron, CS40220, F-38043, Grenoble Cedex 09 (France); Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Lesourd, M. [ESRF-The European Synchrotron, CS40220, F-38043, Grenoble Cedex 09 (France); Dontsov, D. [SIOS Meßtechnik GmbH, Am Vogelherd 46, 98693 Ilmenau (Germany); Cain, M. G. [National Physical Laboratory, Hampton Road, Teddington TW11 0LW (United Kingdom); Electrosciences Ltd., Farnham, Surrey GU9 9QT (United Kingdom)

    2015-10-15

    A new materials characterization system developed at the XMaS beamline, located at the European Synchrotron Radiation Facility in France, is presented. We show that this new capability allows to measure the atomic structural evolution (crystallography) of piezoelectric materials whilst simultaneously measuring the overall strain characteristics and electrical response to dynamically (ac) applied external stimuli.

  16. Modeling dynamic functional connectivity using a wishart mixture model

    DEFF Research Database (Denmark)

    Nielsen, Søren Føns Vind; Madsen, Kristoffer Hougaard; Schmidt, Mikkel Nørgaard

    2017-01-01

    .e. the window length. In this work we use the Wishart Mixture Model (WMM) as a probabilistic model for dFC based on variational inference. The framework admits arbitrary window lengths and number of dynamic components and includes the static one-component model as a special case. We exploit that the WMM...

  17. Illiteracy and diabetic foot complications.

    Science.gov (United States)

    Al-Kaabi, Juma M; Al Maskari, Fatma; Cragg, Paul; Afandi, Bachar; Souid, Abdul-Kader

    2015-12-01

    Diabetes is especially common in the United Arab Emirates. Its complications in patients residing in the region have yet to be fully explored. This study reports on foot problems in our diabetic patients, with emphasis on the impact of illiteracy on foot care and complications due to diabetes. Adults were randomly recruited from the Diabetes Center at Tawam-John Hopkins affiliated hospital. A questionnaire addressing foot care and problems was completed for all patients. In addition, an examination was performed by a trained nurse, an endocrinologist, and a podiatrist. Four hundred twenty-two adults with type 2 (93%) or type 1 (7%) diabetes were enrolled; 67% were females. Patients' mean age was 52 ± 13 years and duration of diabetes ≥ 1 year. Illiterate patients were 51% and were less likely to practice foot care (p=0.002), recognize foot risk factors (p=0.004), use proper footwear (p=0.010), and being physically active (pIlliteracy invoked significant challenges to diabetic attentiveness and imposed increased foot complications. Physicians should realize that illiterate patients are vulnerable and require effective strategies to improve their education about the disease and reduce their diabetic complications. Copyright © 2015 Primary Care Diabetes Europe. Published by Elsevier Ltd. All rights reserved.

  18. Surgical reconstruction in diabetic foot syndrome

    Directory of Open Access Journals (Sweden)

    Umid Shoyusupov

    2011-04-01

    Full Text Available Considerable morbidity upon spontaneous wound healing (phlegmons, osteomyelitis, and purulent osteoarthritis of metatarsophalangeal joint as well as loss of the diseased foot’s walking ability are among the reasons for transition to plastic surgery in management tactics. The longer foot lesion persists, the higher probability of amputation. Improvement of treatment of both wound and ulcer lesions by means of reconstructive surgery in patients with diabetic foot syndrome was the main aim of the study. Outcomes of treatment of 460 patients managed at the Center for the Scientific and Clinical Study of Endocrinology, within the period from 2001 to 2009 were analyzed. Size, form, depth and localization of a wound, tissue composition of the wound bed as well as circulation in skin flaps caused the choice of specific operation: autodermoplasty by Parin (with the split-thickness skin flap, local tissue plastic operation (with the sliding or inter-advancing skin flaps, flaps from previously amputated toe or Indian flaps, plastic operation with the controlled tissue tension or combined plastic operation. Reconstructive foot wound surgery allows restoring load-bearing function of the extremity much earlier in contrast to spontaneous healing, reducing incidence of post-operative and long-term complications, amputations and re-amputations, decreasing period of treatment.

  19. Mycetoma (Madura foot): A case report.

    Science.gov (United States)

    Asly, M; Rafaoui, A; Bouyermane, H; Hakam, K; Moustamsik, B; Lmidmani, F; Rafai, M; Largab, A; Elfatimi, A

    2010-12-01

    Mycetoma is a chronic disease, which is endemic in tropical and subtropical countries. We report a rare case of mycetoma located on the foot of a patient living in a temperate-climate country followed by a short discussion. A 50-year-old woman with painless swelling in her left foot. The swelling started after a banal penetrating injury on the sole of her left foot 23 years ago. X-rays images showed multiple osteolytic lesions of the tarsus. The histological analyses identified the fungus madurella mycetomatis. The treatment was radical surgery (amputation). The patient had a tibial prosthesis and recovered an autonomous gait. Mycetoma is a chronic granulomatous inflammatory response often with sinus tract formations due to fungal or bacterial organisms. The infection of the forefoot is quite typical. It is a slowly progressing disease affecting the deep dermis and subcutaneous tissues that can extent to the underlying bones. If it is not diagnosed early on, mycetoma can cause functional and esthetical impairments. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

  20. Comparison of the Internal Dynamics of Metalloproteases Provides New Insights on Their Function and Evolution.

    Directory of Open Access Journals (Sweden)

    Henrique F Carvalho

    Full Text Available Metalloproteases have evolved in a vast number of biological systems, being one of the most diverse types of proteases and presenting a wide range of folds and catalytic metal ions. Given the increasing understanding of protein internal dynamics and its role in enzyme function, we are interested in assessing how the structural heterogeneity of metalloproteases translates into their dynamics. Therefore, the dynamical profile of the clan MA type protein thermolysin, derived from an Elastic Network Model of protein structure, was evaluated against those obtained from a set of experimental structures and molecular dynamics simulation trajectories. A close correspondence was obtained between modes derived from the coarse-grained model and the subspace of functionally-relevant motions observed experimentally, the later being shown to be encoded in the internal dynamics of the protein. This prompted the use of dynamics-based comparison methods that employ such coarse-grained models in a representative set of clan members, allowing for its quantitative description in terms of structural and dynamical variability. Although members show structural similarity, they nonetheless present distinct dynamical profiles, with no apparent correlation between structural and dynamical relatedness. However, previously unnoticed dynamical similarity was found between the relevant members Carboxypeptidase Pfu, Leishmanolysin, and Botulinum Neurotoxin Type A, despite sharing no structural similarity. Inspection of the respective alignments shows that dynamical similarity has a functional basis, namely the need for maintaining proper intermolecular interactions with the respective substrates. These results suggest that distinct selective pressure mechanisms act on metalloproteases at structural and dynamical levels through the course of their evolution. This work shows how new insights on metalloprotease function and evolution can be assessed with comparison schemes that

  1. Functional Nanostructures and Dynamic Materials through Self-Organization

    Institute of Scientific and Technical Information of China (English)

    Jean-Marie; LEHN

    2007-01-01

    1 Results Supramolecular chemistry is actively exploring systems undergoing self-organization.The design of molecular information controlled,"programmed"and functional self-organizing systems provides an original approach to nanoscience and nanotechnology.The spontaneous but controlled generation of well-defined,functional molecular and supramolecular architectures of nanometric size through self-organization represents a means of performing programmed engineering and processing of functional nanostruct...

  2. Nociception at the diabetic foot, an uncharted territory.

    Science.gov (United States)

    Chantelau, Ernst A

    2015-04-15

    The diabetic foot is characterised by painless foot ulceration and/or arthropathy; it is a typical complication of painless diabetic neuropathy. Neuropathy depletes the foot skin of intraepidermal nerve fibre endings of the afferent A-delta and C-fibres, which are mostly nociceptors and excitable by noxious stimuli only. However, some of them are cold or warm receptors whose functions in diabetic neuropathy have frequently been reported. Hence, it is well established by quantitative sensory testing that thermal detection thresholds at the foot skin increase during the course of painless diabetic neuropathy. Pain perception (nociception), by contrast, has rarely been studied. Recent pilot studies of pinprick pain at plantar digital skinfolds showed that the perception threshold was always above the upper limit of measurement of 512 mN (equivalent to 51.2 g) at the diabetic foot. However, deep pressure pain perception threshold at musculus abductor hallucis was beyond 1400 kPa (equivalent to 14 kg; limit of measurement) only in every fifth case. These discrepancies of pain perception between forefoot and hindfoot, and between skin and muscle, demand further study. Measuring nociception at the feet in diabetes opens promising clinical perspectives. A critical nociception threshold may be quantified (probably corresponding to a critical number of intraepidermal nerve fibre endings), beyond which the individual risk of a diabetic foot rises appreciably. Staging of diabetic neuropathy according to nociception thresholds at the feet is highly desirable as guidance to an individualised injury prevention strategy.

  3. Dynamics of homegarden structure and function in Kerala, India

    OpenAIRE

    PEYRE, A.; Guidal, A.; Wiersum, K.F.; Bongers, F.J.J.M.

    2006-01-01

    Homegardens in Kerala have long been important multi-purpose agroforestry systems that combine ecological and socioeconomical sustainability. However, traditional homegardens are subject to different conversion processes linked to socioeconomic changes. These dynamics were studied in a survey of 30 homegardens. On the basis of a cluster analysis of tree/shrub species density and subsequent further grouping using homegarden size as additional characteristic, six homegarden types were different...

  4. Inter-assessor reliability of practice based biomechanical assessment of the foot and ankle

    Directory of Open Access Journals (Sweden)

    Jarvis Hannah L

    2012-06-01

    Full Text Available Abstract Background There is no consensus on which protocols should be used to assess foot and lower limb biomechanics in clinical practice. The reliability of many assessments has been questioned by previous research. The aim of this investigation was to (i identify (through consensus what biomechanical examinations are used in clinical practice and (ii evaluate the inter-assessor reliability of some of these examinations. Methods Part1: Using a modified Delphi technique 12 podiatrists derived consensus on the biomechanical examinations used in clinical practice. Part 2: Eleven podiatrists assessed 6 participants using a subset of the assessment protocol derived in Part 1. Examinations were compared between assessors. Results Clinicians choose to estimate rather than quantitatively measure foot position and motion. Poor inter-assessor reliability was recorded for all examinations. Intra-class correlation coefficient values (ICC for relaxed calcaneal stance position were less than 0.23 and were less than 0.14 for neutral calcaneal stance position. For the examination of ankle joint dorsiflexion, ICC values suggest moderate reliability (less than 0.61. The results of a random effects ANOVA highlight that participant (up to 5.7°, assessor (up to 5.8° and random (up to 5.7° error all contribute to the total error (up to 9.5° for relaxed calcaneal stance position, up to 10.7° for the examination of ankle joint dorsiflexion. Kappa Fleiss values for categorisation of first ray position and mobility were less than 0.05 and for limb length assessment less than 0.02, indicating slight agreement. Conclusion Static biomechanical assessment of the foot, leg and lower limb is an important protocol in clinical practice, but the key examinations used to make inferences about dynamic foot function and to determine orthotic prescription are unreliable.

  5. Simulation study and function analysis of the dynamic aortic valve

    Institute of Scientific and Technical Information of China (English)

    XIA Dongdong; BAI Jing

    2006-01-01

    The dynamic aortic valve (DAV) is a new left ventricular assist device, a micro-axial blood pump implemented at the position of the aortic valve, pumping blood from the left ventricle into the aortic artery. The present dynamic aortic valve operates at 7 different rotation speeds, ranging from 3000 r/min (speed 1) to 9000 r/min (speed 7). Because in vivo experiments need a lot of live animals and take a long period of time, modeling and simulation have been widely used to simulate and analyze hydra-dynamic property of the DAV and its assisting effects. With the measurements from the mock circulatory loop, a mathematic model of the DAV is established and embedded into the previously developed canine circulatory system. Using this model, the effect of the DAV on the failing heart at each rotation speed level is investigated. The vital cardiac variables are computed and compared with in vivo experimental results, which are in good agreement with an acceptable difference mostly 15 %. The establishment of the DAV model and its simulation are useful for further improvement of the DAV device.

  6. Dynamic Colour Possibilities and Functional Properties of Thermochromic Printing Inks

    Directory of Open Access Journals (Sweden)

    Rahela Kulcar

    2012-07-01

    Full Text Available Thermochromic printing inks change their colour regarding the change in temperature and they are one of the major groups of colour-changing inks. One of the most frequently used thermochromic material in printing inks are leuco dyes. The colour of thermochromic prints is dynamic, it is not just temperature-dependent, but it also depends on thermal history. The effect is described by colour hysteresis. This paper aims at discussing general aspects of thermochromic inks, dynamic colorimetric properties of leuco dye-based thermochromic inks, their stability and principle of variable-temperature colour measurement. Thermochromic material is protected in round-shaped capsules. They are much larger than pigments in conventional inks. The polymer envelopes of pigment capsules are more stable against oxidation than the binder. If these envelopes are damaged, the dynamic colour is irreversibly lost. Our aim is to analyse the colorimetric properties of several reversible screen-printed UV-curing leuco dye thermochromic inks with different activation temperatures printed on paper. A small analysis of irreversible thermochromic inks will be presented for comparison with reversible thermochromic inks. Moreover, so as to show interesting possibilities, a combination of different inks was made, an irreversible thermochromic ink was printed on top of the red and blue reversible thermochromic inks. Special attention was given to the characterization of colour hysteresis and the meaning of activation temperature.

  7. The clinical assessment study of the foot (CASF: study protocol for a prospective observational study of foot pain and foot osteoarthritis in the general population

    Directory of Open Access Journals (Sweden)

    Menz Hylton B

    2011-09-01

    Full Text Available Abstract Background Symptomatic osteoarthritis (OA affects approximately 10% of adults aged over 60 years. The foot joint complex is commonly affected by OA, yet there is relatively little research into OA of the foot, compared with other frequently affected sites such as the knee and hand. Existing epidemiological studies of foot OA have focussed predominantly on the first metatarsophalangeal joint at the expense of other joints. This three-year prospective population-based observational cohort study will describe the prevalence of symptomatic radiographic foot OA, relate its occurrence to symptoms, examination findings and life-style-factors, describe the natural history of foot OA, and examine how it presents to, and is diagnosed and managed in primary care. Methods All adults aged 50 years and over registered with four general practices in North Staffordshire, UK, will be invited to participate in a postal Health Survey questionnaire. Respondents to the questionnaire who indicate that they have experienced foot pain in the preceding twelve months will be invited to attend a research clinic for a detailed clinical assessment. This assessment will consist of: clinical interview; physical examination; digital photography of both feet and ankles; plain x-rays of both feet, ankles and hands; ultrasound examination of the plantar fascia; anthropometric measurement; and a further self-complete questionnaire. Follow-up will be undertaken in consenting participants by postal questionnaire at 18 months (clinic attenders only and three years (clinic attenders and survey participants, and also by review of medical records. Discussion This three-year prospective epidemiological study will combine survey data, comprehensive clinical, x-ray and ultrasound assessment, and review of primary care records to identify radiographic phenotypes of foot OA in a population of community-dwelling older adults, and describe their impact on symptoms, function and

  8. Poisson structure and Casimir functions for a noncentral dynamical system in four-dimensional phase space

    Institute of Scientific and Technical Information of China (English)

    Lou Zhi-Mei; Chen Zi-Dong; Wang Wen-Long

    2005-01-01

    In this paper, we express the differential equations of a noncentral dynamical system in Ermakov formalism to obtain the Ermakov invariant. In term of Hamiltonian theories and using the Ermakov invariant as the Hamiltonian,the Poisson structure of a noncentral dynamical system in four-dimensional phase space are constructed. The result indicates that the Poisson structure is degenerate and the noncentral dynamical system possesses four invariants: the Hamiltonian, the Ermakov invariant and two Casimir functions.

  9. Dynamic Function of the Alkyl Spacer of Acetogenins as Potent Inhibitors of Mitochondrial Complex I. A Molecular Dynamics Simulation Approach

    NARCIS (Netherlands)

    Abel Bombasaro, Jose; Barrera Guisasola, Exequiel Ernesto; Masman, Marcelo Fabricio; Angel Zamora, Miguel; Maria Rodriguez, Ana

    2013-01-01

    Acetogenins are among the most potent of the known inhibitors of complex I (NADH-ubiquinone oxidoreductase) in mitochondrial electron transfer system. Elucidation of the dynamic function of the alkyl spacer linking the two toxophores (i.e., the hydroxylated tetrahydrofuran and the gamma-lactone

  10. Can toe-ground footwear margin alter swing-foot ground clearance?

    Science.gov (United States)

    Nagano, Hanatsu; Sparrow, W A; Begg, Rezaul K

    2015-07-01

    Falls are an important healthcare concern in the older population and tripping is the primary cause. Greater swing foot-ground clearance is functional for tripping prevention. Trips frequently occur due to the lowest part of the shoe contacting the walking surface. Shoe design effects on swing foot-ground clearance are, therefore, important considerations. When a shoe is placed on a flat surface, there usually is small vertical margin (VM) between the walking surface and the minimum toe point (MTP). The current study examined the effects of VM on swing foot-ground clearance at a critical gait cycle event, minimum foot clearance (MFC). 3D coordinates of the swing foot (i.e. MTP and heel) were obtained during the swing phase. MTP represented the swing foot-ground clearance and various MTPs were modelled based on a range of VMs. The sagittal orientation of the toe and heel relative to the walking surface was also considered to evaluate effects of VM and swing foot angle on foot-ground clearance. Greater VM increased the swing foot-ground clearance. At MFC, for example, 0.09 cm increase was estimated for every 0.1cm VM. Foot angle throughout the swing phase was typically -30° and 70°. Increasing swing ankle dorsiflexion can maximise VM, which is effective for tripping prevention. Further research will be needed to determine the maximum thresholds of VM to be safely incorporated into a shoe. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Effects of Wearing Different Personal Equipment on Force Distribution at the Plantar Surface of the Foot

    Directory of Open Access Journals (Sweden)

    Christoph Schulze

    2013-01-01

    Full Text Available Background. The wearing of personal equipment can cause specific changes in muscle activity and posture. In the present study, we investigated the influence of differences in equipment related weight loading and load distribution on plantar pressure. In addition, we studied functional effects of wearing different equipment with a particular focus on relevant changes in foot shape. Methods. Static and dynamic pedobarography were performed on 31 male soldiers carrying increasing weights consisting of different items of equipment. Results. The pressure acting on the plantar surface of the foot increased with higher loading, both under static and dynamic conditions (p < 0.05. We observed an increase in the contact area (p < 0.05 and an influence of load distribution through different ways to carry the rifle. Conclusions. The wearing of heavier weights leads to an increase in plantar pressure and contact area. This may be caused by flattening of the transverse and longitudinal arches. The effects are more evident in subjects with flat feet deformities which seem to flatten at an earlier load condition with a greater amount compared to subjects with normal arches. Improving load distribution should be a main goal in the development of military equipment in order to prevent injuries or functional disorders of the lower extremity.

  12. Bacteriology of diabetic foot lesions.

    Science.gov (United States)

    Yoga, R; Khairul, A; Sunita, K; Suresh, C

    2006-02-01

    Infection plays a pivotal role in enhancing a diabetic foot at risk toward amputation. Effective antibiotic therapy against the offending pathogens is an important component of treatment of diabetic foot infections. Recognition of the pathogen is always difficult as the representative deep tissue sample for culture is surrounded by ulcer surface harbouring colonies of organisms frequently labelled as skin commensals. The emergent of resistant strains represents a compounding problem standing against efforts to prevent amputation. This study was undertaken to identify the pathogens associated with diabetic foot infection in terms of their frequency and sensitivity against certain commonly used antibiotics. Forty-four consecutive patients with open diabetic foot infections had wound swab taken for culture and sensitivity testing. Cultures positive were observed in 89% of the cases with Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeroginosa encountered in 20%, 14% and 14% of cases respectively. Mixed growths were isolated in 6% of cultures. All Staphylcoccus aureus isolates were resistant to Penicillin but 80% were sensitive to Erythromycin and Co-trimoxazole. Klebsiella pneumoniae isolates were sensitive to Methicillin and Gentamycin in 80% and 60% of cases respectively, and resistant to Ampicillin and Ceftazidime in 83% and 50% respectively. All Pseudomonas aeroginosa isolates were sensitive to Amikacin and Ciprofloxacin but 50% were resistant to Gentamycin. There was no single antibiotic possessing good coverage for all common organisms isolated from diabetic foot lesions. Staphylococcus aureus remains the predominant cause of diabetic foot infections followed by Klebsiela pneumonia and Pseudomonas aeroginosa. Most infections are monomicrobial. The emergence of multiresistant organisms is a worrying feature in diabetic foot infections.

  13. Differences in dynamic and static functional connectivity between young and elderly healthy adults.

    Science.gov (United States)

    Park, Ji Eun; Jung, Seung Chai; Ryu, Kyeoung Hwa; Oh, Joo Young; Kim, Ho Sung; Choi, Choong-Gon; Kim, Sang Joon; Shim, Woo Hyun

    2017-08-01

    Brain connectivity is highly dynamic, but functional connectivity (FC) studies using resting-state functional magnetic resonance imaging (rs-fMRI) assume it to be static. This study assessed differences in dynamic FC between young healthy adults (YH) and elderly healthy adults (EH) compared to static FC. Using rs-fMRI data from 12 YH and 31 EH, FC was assessed in six functional regions (subcortical, auditory [AUD], sensorimotor [SM], visuospatial [VS], cognitive control [CC], and default mode network [DMN]). Static FC was calculated as Fisher's z-transformed correlation coefficient. The sliding time window correlation (window size 30 s, step size 3 s) was applied for dynamic FC, and the standard deviation across sliding windows was calculated. Differences in static and dynamic FC between EH and YH were calculated and compared by region. EH showed decreased static FC in the subcortical, CC, and DMN regions (FDR corrected p = 0.0013; 74 regions), with no regions showing static FC higher than that in YH. EH showed increased dynamic FC in the subcortical, CC, and DMN regions, whereas decreased dynamic FC in CC and DMN regions (p static and dynamic FC. Dynamic FC exhibited differences from static FC in EH and YH, mainly in regions involved in cognitive control and the DMN. Altered dynamic FC demonstrated both qualitatively and quantitatively distinct patterns of transient brain activity and needs to be studied as an imaging biomarker in the aging process.

  14. COVER CROPS ENHANCE SOIL ORGANIC MATTER, CARBON DYNAMICS AND MICROBIOLOGICAL FUNCTION IN A MEDITERRANEAN VINEYARD AGROECOSYSTEM

    Science.gov (United States)

    Impacts of soil tillage and cover crops on soil carbon (C) dynamics and microbiological function were investigated in a vineyard grown in California’s Mediterranean climate. We 1) compared soil organic matter (SOM), C dynamics and microbiological activity of two cover crops [Trios 102 (Triticale x T...

  15. Transfer function analysis of dynamic cerebral autoregulation in humans

    Science.gov (United States)

    Zhang, R.; Zuckerman, J. H.; Giller, C. A.; Levine, B. D.; Blomqvist, C. G. (Principal Investigator)

    1998-01-01

    To test the hypothesis that spontaneous changes in cerebral blood flow are primarily induced by changes in arterial pressure and that cerebral autoregulation is a frequency-dependent phenomenon, we measured mean arterial pressure in the finger and mean blood flow velocity in the middle cerebral artery (VMCA) during supine rest and acute hypotension induced by thigh cuff deflation in 10 healthy subjects. Transfer function gain, phase, and coherence function between changes in arterial pressure and VMCA were estimated using the Welch method. The impulse response function, calculated as the inverse Fourier transform of this transfer function, enabled the calculation of transient changes in VMCA during acute hypotension, which was compared with the directly measured change in VMCA during thigh cuff deflation. Beat-to-beat changes in VMCA occurred simultaneously with changes in arterial pressure, and the autospectrum of VMCA showed characteristics similar to arterial pressure. Transfer gain increased substantially with increasing frequency from 0.07 to 0.20 Hz in association with a gradual decrease in phase. The coherence function was > 0.5 in the frequency range of 0.07-0.30 Hz and transfer function with the quality of a high-pass filter in the frequency range of 0.07-0.30 Hz.

  16. Three dimensional design, simulation and optimization of a novel, universal diabetic foot offloading orthosis

    Science.gov (United States)

    Sukumar, Chand; Ramachandran, K. I.

    2016-09-01

    Leg amputation is a major consequence of aggregated foot ulceration in diabetic patients. A common sense based treatment approach for diabetic foot ulceration is foot offloading where the patient is required to wear a foot offloading orthosis during the entire treatment course. Removable walker is an excellent foot offloading modality compared to the golden standard solution - total contact cast and felt padding. Commercially available foot offloaders are generally customized with huge cost and less patient compliance. This work suggests an optimized 3D model of a new type light weight removable foot offloading orthosis for diabetic patients. The device has simple adjustable features which make this suitable for wide range of patients with weight of 35 to 74 kg and height of 137 to 180 cm. Foot plate of this orthosis is unisexual, with a size adjustability of (US size) 6 to 10. Materials like Aluminum alloy 6061-T6, Acrylonitrile Butadiene Styrene (ABS) and Polyurethane acted as the key player in reducing weight of the device to 0.804 kg. Static analysis of this device indicated that maximum stress developed in this device under a load of 1000 N is only 37.8 MPa, with a small deflection of 0.150 cm and factor of safety of 3.28, keeping the safety limits, whereas dynamic analysis results assures the load bearing capacity of this device. Thus, the proposed device can be safely used as an orthosis for offloading diabetic ulcerated foot.

  17. Finite element modeling of a 3D coupled foot-boot model.

    Science.gov (United States)

    Qiu, Tian-Xia; Teo, Ee-Chon; Yan, Ya-Bo; Lei, Wei

    2011-12-01

    Increasingly, musculoskeletal models of the human body are used as powerful tools to study biological structures. The lower limb, and in particular the foot, is of interest because it is the primary physical interaction between the body and the environment during locomotion. The goal of this paper is to adopt the finite element (FE) modeling and analysis approaches to create a state-of-the-art 3D coupled foot-boot model for future studies on biomechanical investigation of stress injury mechanism, foot wear design and parachute landing fall simulation. In the modeling process, the foot-ankle model with lower leg was developed based on Computed Tomography (CT) images using ScanIP, Surfacer and ANSYS. Then, the boot was represented by assembling the FE models of upper, insole, midsole and outsole built based on the FE model of the foot-ankle, and finally the coupled foot-boot model was generated by putting together the models of the lower limb and boot. In this study, the FE model of foot and ankle was validated during balance standing. There was a good agreement in the overall patterns of predicted and measured plantar pressure distribution published in literature. The coupled foot-boot model will be fully validated in the subsequent works under both static and dynamic loading conditions for further studies on injuries investigation in military and sports, foot wear design and characteristics of parachute landing impact in military.

  18. Riemann zeta function from wave-packet dynamics

    DEFF Research Database (Denmark)

    Mack, R.; Dahl, Jens Peder; Moya-Cessa, H.

    2010-01-01

    is governed by the temperature of the thermal phase state and tau is proportional to t. We use the JWKB method to solve the inverse spectral problem for a general logarithmic energy spectrum; that is, we determine a family of potentials giving rise to such a spectrum. For large distances, all potentials...... index of JWKB. We compare and contrast exact and approximate eigenvalues of purely logarithmic potentials. Moreover, we use a numerical method to find a potential which leads to exact logarithmic eigenvalues. We discuss possible realizations of Riemann zeta wave-packet dynamics using cold atoms...

  19. Vacuum energy as a c-function for theories with dynamically generated masses

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar, A.C., E-mail: arlene.aguilar@ufabc.edu.b [Federal University of ABC, CCNH, Rua Santa Adelia 166, 09210-170, Santo Andre (Brazil); Doff, A. [Universidade Tecnologica Federal do Parana - UTFPR, COMAT, Via do Conhecimento Km 01, 85503-390, Pato Branco, PR (Brazil); Natale, A.A. [Instituto de Fisica Teorica, UNESP - Universidade Estadual Paulista, Rua Dr. Bento T. Ferraz, 271, Bloco II, 01140-070, Sao Paulo (Brazil)

    2011-01-24

    We argue that in asymptotically free non-Abelian gauge theories possessing the phenomenon of dynamical mass generation the {beta} function is negative up to a value of the coupling constant that corresponds to a non-trivial fixed point, in agreement with recent AdS/QCD analysis. This fixed point happens at the minimum of the vacuum energy ({Omega}), which, as a characteristic of theories with dynamical mass generation, has the properties of a c-function.

  20. Postural stability of biped robots and the foot-rotation indicator (FRI) point

    Energy Technology Data Exchange (ETDEWEB)

    Goswami, A. [Univ. of Pennsylvania, Philadelphia, PA (United States). Dept. of Computer and Information Science

    1999-06-01

    The focus of this paper is the problem of foot rotation in biped robots during the single-support phase. Foot rotation is an indication of postural instability, which should be carefully treated in a dynamically stable walk and avoided altogether in a statically stable walk. The author introduces the foot-rotation indicator (FRI) point, which is a point on the foot/ground-contact surface where the net ground-reaction force would have to act to keep the foot stationary. To ensure no foot rotation, the FRI point must remain within the convex hull of the foot-support area. In contrast with the ground projection of the center of mass (GCoM), which is a static criterion, the FRI point incorporates robot dynamics. As opposed to the center of pressure (CoP) -- better known as the zero-moment point (ZMP) in the robotics literature -- which may not leave the support area, the FRI point may leave the area. In fact, the position of the FRI point outside the footprint indicates the direction of the impending rotation and the magnitude of rotational moment acting on the foot. Owing to these important properties, the FRI point helps not only to monitor the state of postural stability of a biped robot during the entire gait cycle, but indicates the severity of instability of the gait as well. In response to a recent need, the paper also resolves the misconceptions surrounding the CoP/ZMP equivalence.

  1. Modeling dynamic functional information flows on large-scale brain networks.

    Science.gov (United States)

    Lv, Peili; Guo, Lei; Hu, Xintao; Li, Xiang; Jin, Changfeng; Han, Junwei; Li, Lingjiang; Liu, Tianming

    2013-01-01

    Growing evidence from the functional neuroimaging field suggests that human brain functions are realized via dynamic functional interactions on large-scale structural networks. Even in resting state, functional brain networks exhibit remarkable temporal dynamics. However, it has been rarely explored to computationally model such dynamic functional information flows on large-scale brain networks. In this paper, we present a novel computational framework to explore this problem using multimodal resting state fMRI (R-fMRI) and diffusion tensor imaging (DTI) data. Basically, recent literature reports including our own studies have demonstrated that the resting state brain networks dynamically undergo a set of distinct brain states. Within each quasi-stable state, functional information flows from one set of structural brain nodes to other sets of nodes, which is analogous to the message package routing on the Internet from the source node to the destination. Therefore, based on the large-scale structural brain networks constructed from DTI data, we employ a dynamic programming strategy to infer functional information transition routines on structural networks, based on which hub routers that most frequently participate in these routines are identified. It is interesting that a majority of those hub routers are located within the default mode network (DMN), revealing a possible mechanism of the critical functional hub roles played by the DMN in resting state. Also, application of this framework on a post trauma stress disorder (PTSD) dataset demonstrated interesting difference in hub router distributions between PTSD patients and healthy controls.

  2. Objective assessment of foot strike in Parkinson's disease*.

    Science.gov (United States)

    Contin, M; Riva, R; Martinelli, P; Balboni, M; Tonello, C; Albani, F; Baruzzi, A

    1996-05-01

    We assessed the nature of foot strike and the potential effect of acute levodopa dosing in Parkinsonian patients with mild to severe fluctuations of motor performances in comparison with healthy volunteers. Forty-eight patients were enrolled in the study and compared with 33 age and gender matched controls. Each patient was assessed by a computerized electropodographic system before levodopa dosing and 1 and 2-h after intake of a standard fasting morning dose of levodopa plus benserazide. Twelve foot strikes (six right, six left) were analysed per patient. The controls underwent three repeated examinations at 1-h intervals. Patients' motor response to acute levodopa dosing was evaluated at fixed times by a battery of motor tests. Foot strike dynamics differed between patients and controls: in particular, first ground contact of the foot was significantly shifted from heel to forefoot in patients compared to controls. The forward shift in footprint during walking was more marked on the more affected body side but was unrelated to the severity and duration of Parkinsonism and unresponsive to levodopa dosing. Tapping and walking tests were overall responsive to acute levodopa intake. The system seemed suitable to detect irregular patterns of foot strike even at the early stages of Parkinsonism, when lower limb disorder was not clinically overt, and might be useful in the search for clinical markers of Parkinsonian gait.

  3. Evaluating the biomechanics of the pediatric foot in Turner syndrome: a case report.

    Science.gov (United States)

    Morrison, Stewart C; Izod, Alexander; Mahaffey, Ryan

    2012-01-01

    Turner syndrome is a genetic disorder that can present clinically with multiple concurrent comorbidities. This case report describes a 12-year-old girl with Turner syndrome who was referred for podiatric medical assessment and explores the application of optoelectronic stereophotogrammetry in the biomechanical assessment of the foot and lower limb. A four-segment kinematic foot model using 14-mm reflective markers was applied to the foot and lower limb of the patient to track motion at the tibia, rearfoot, forefoot, and hallux. Kinematic results presented in this case study illustrate evidence of excessive foot pronation throughout the stance phase of gait. Whether excessive pronation is a general characteristic of foot function in Turner syndrome remains to be confirmed, but the findings presented suggest that a comprehensive evaluation of foot biomechanics in patients with Turner syndrome may be warranted.

  4. Charcot neuroarthropathy: realignment of diabetic foot by means of osteosynthesis using intramedullary screws – case report,

    Directory of Open Access Journals (Sweden)

    Alexandre Leme Godoy dos Santos

    2014-10-01

    Full Text Available Diabetes mellitus is a serious disease that affects a large portion of the population. Charcot neuroarthropathy is one of its major complications and can lead to osteoarticular deformities, functional incapacity, ulcers and ankle and foot infections. Realignment of the foot by means of arthrodesis presents a high rate of implant failure due to weight-bearing on an insensitive foot. The aim of this report was to describe successful use of intramedullary osteosynthesis with compression screws to stabilize the deformed foot, in a diabetic patient with neuroarthropathy.

  5. Charcot neuroarthropathy: realignment of diabetic foot by means of osteosynthesis using intramedullary screws - case report.

    Science.gov (United States)

    Dos Santos, Alexandre Leme Godoy; Albino, Rômulo Ballarin; Ortiz, Rafael Trevisan; Sakaki, Marcos Hideyo; de Andrade Corsato, Marcos; Fernandes, Tulio Diniz

    2014-01-01

    Diabetes mellitus is a serious disease that affects a large portion of the population. Charcot neuroarthropathy is one of its major complications and can lead to osteoarticular deformities, functional incapacity, ulcers and ankle and foot infections. Realignment of the foot by means of arthrodesis presents a high rate of implant failure due to weight-bearing on an insensitive foot. The aim of this report was to describe successful use of intramedullary osteosynthesis with compression screws to stabilize the deformed foot, in a diabetic patient with neuroarthropathy.

  6. Season physical functioning dynamic of men with different physical condition

    Directory of Open Access Journals (Sweden)

    Prushva O.B.

    2015-10-01

    Full Text Available Purpose: study season peculiarities of physical functioning of men with different physical condition. Material: in the research 53 men of 41-55 years’ age without chronic disease, who practiced healthy life style, participated. It was assessed: daily physical functioning of different intensity with the help of bio-register BASIS B1; body mass index; adaptation potential of Bayevskiy. Results: we determined that men with normal adaptation potential have less quantity of highly intensive steps than men with excessively tensed adaptation potential of cardio-vascular system. Men with tensed adaptation potential have less expressed season changes in physical functioning. Conclusions: We found the following optimal correlations: total quantity of steps per day; quantity of steps with average intensity (80-86 steps per min.; total run steps of high intensity (140-145 steps per min.; quantity of low intensity steps (8-10 steps per min..

  7. The nucleon wave function in light-front dynamics

    CERN Document Server

    Karmanov, V A

    1998-01-01

    The general spin structure of the relativistic nucleon wave function in the $3q$-model is found. It contains 16 spin components, in contrast to 8 ones known previously, since in a many-body system the parity conservation does not reduce the number of the components. The explicitly covariant form of the wave function automatically takes into account the relativistic spin rotations, without introducing any Melosh rotation matrices. It also reduces the calculations to the standard routine of the Dirac matrices and of the trace techniques. In examples of the proton magnetic moment and of the axial nucleon form factor, with a particular wave function, we reproduce the results of the standard approach. Calculations beyond the standard assumptions give different results.

  8. Strong semiclassical approximation of Wigner functions for the Hartree dynamics

    KAUST Repository

    Athanassoulis, Agissilaos

    2011-01-01

    We consider the Wigner equation corresponding to a nonlinear Schrödinger evolution of the Hartree type in the semiclassical limit h → 0. Under appropriate assumptions on the initial data and the interaction potential, we show that the Wigner function is close in L 2 to its weak limit, the solution of the corresponding Vlasov equation. The strong approximation allows the construction of semiclassical operator-valued observables, approximating their quantum counterparts in Hilbert-Schmidt topology. The proof makes use of a pointwise-positivity manipulation, which seems necessary in working with the L 2 norm and the precise form of the nonlinearity. We employ the Husimi function as a pivot between the classical probability density and the Wigner function, which - as it is well known - is not pointwise positive in general.

  9. The influence of the program of prophylaxis of flat foot on the biomechanics characteristics of foot of children of pre-school age

    Directory of Open Access Journals (Sweden)

    Bychuk I.O.

    2011-02-01

    Full Text Available In the article is defined linear and angular biomechanics descriptions of children's foot of senior preschool age. It is analysed the dynamics and increase of the explored indexes during realization of the program of prophylaxis of flat foot in the teaching process. In experiment took part teachers and instructors of physical culture; control and experimental group consist of 20 children at the age of 5-6 years old. Efficiency of the offered program of prophylaxis of flat foot is proved.

  10. deFUME: Dynamic exploration of functional metagenomic sequencing data

    DEFF Research Database (Denmark)

    van der Helm, Eric; Geertz-Hansen, Henrik Marcus; Genee, Hans Jasper

    2015-01-01

    Functional metagenomic selections represent a powerful technique that is widely applied for identification of novel genes from complex metagenomic sources. However, whereas hundreds to thousands of clones can be easily generated and sequenced over a few days of experiments, analyzing the data...... to a comprehensive visual data overview that facilitates effortless inspection of gene function, clustering and distribution. The webserver is available at cbs.dtu.dk/services/deFUME/and the source code is distributed at github.com/EvdH0/deFUME....

  11. Quantum power functional theory for many-body dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Matthias, E-mail: Matthias.Schmidt@uni-bayreuth.de [Theoretische Physik II, Physikalisches Institut, Universität Bayreuth, D-95440 Bayreuth (Germany)

    2015-11-07

    We construct a one-body variational theory for the time evolution of nonrelativistic quantum many-body systems. The position- and time-dependent one-body density, particle current, and time derivative of the current act as three variational fields. The generating (power rate) functional is minimized by the true current time derivative. The corresponding Euler-Lagrange equation, together with the continuity equation for the density, forms a closed set of one-body equations of motion. Space- and time-nonlocal one-body forces are generated by the superadiabatic contribution to the functional. The theory applies to many-electron systems.

  12. Organizational dynamics, functions, and pathobiological dysfunctions of neurofilaments.

    Science.gov (United States)

    Shea, Thomas B; Chan, Walter K-H; Kushkuley, Jacob; Lee, Sangmook

    2009-01-01

    Neurofilament phosphorylation has long been considered to regulate their axonal transport rate, and in doing so it provides stability to mature axons. We evaluate the collective evidence to date regarding how neurofilament C-terminal phosphorylation may regulate axonal transport. We present a few suggestions for further experimentation in this area, and expand upon previous models for axonal NF dynamics. We present evidence that the NFs that display extended residence along axons are critically dependent upon the surrounding microtubules, and that simultaneous interaction with multiple microtubule motors provides the architectural force that regulates their distribution. Finally, we address how C-terminal phosphorylation is regionally and temporally regulated by a balance of kinase and phosphatase activities, and how misregulation of this balance might contribute to motor neuron disease.

  13. Measuring Dynamic Kidney Function in an Undergraduate Physiology Laboratory

    Science.gov (United States)

    Medler, Scott; Harrington, Frederick

    2013-01-01

    Most undergraduate physiology laboratories are very limited in how they treat renal physiology. It is common to find teaching laboratories equipped with the capability for high-resolution digital recordings of physiological functions (muscle twitches, ECG, action potentials, respiratory responses, etc.), but most urinary laboratories still rely on…

  14. Analysis of dynamic pulmonary functions in air conditioned work environment

    Directory of Open Access Journals (Sweden)

    Anu T. E.

    2016-07-01

    Conclusions: The results of the study indicate that the subjects working in AC environment for a long duration are prone to develop restrictive lung diseases. Hence, study concludes that periodic pulmonary function assessment should be made mandatory. Further, regular maintenance of ACs is also recommended. [Int J Res Med Sci 2016; 4(7.000: 2661-2664

  15. Assessing Sensorimotor Function Following ISS with Computerized Dynamic Posturography.

    Science.gov (United States)

    Wood, Scott J; Paloski, William H; Clark, Jonathan B

    2015-12-01

    Postflight postural ataxia reflects both the control strategies adopted for movement in microgravity and the direct effects of deconditioning. Computerized dynamic posturography (CDP) has been used during the first decade of the International Space Station (ISS) expeditions to quantify the initial postflight decrements and recovery of postural stability. The CDP data were obtained on 37 crewmembers as part of their pre- and postflight medical examinations. Sensory organization tests evaluated the ability to make effective use of (or suppress inappropriate) visual, vestibular, and somatosensory information for balance control. This report focuses on eyes closed conditions with either a fixed or sway-referenced base of support, with the head erect or during pitch-head tilts (± 20° at 0.33 Hz). Equilibrium scores were derived from peak-to-peak anterior-posterior sway. Motor-control tests were also used to evaluate a crewmember's ability to automatically recover from unexpected support-surface perturbations. The standard Romberg condition was the least sensitive. Dynamic head tilts led to increased incidence of falls and revealed significantly longer recovery than head-erect conditions. Improvements in postflight postural performance during the later expeditions may be attributable to higher preflight baselines and/or advanced exercise capabilities aboard the ISS. The diagnostic assessment of postural instability is more pronounced during unstable-support conditions requiring active head movements. In addition to supporting return-to-duty decisions by flight surgeons, the CDP provides a standardized sensorimotor measure that can be used to evaluate the effectiveness of countermeasures designed to either minimize deconditioning on orbit or promote reconditioning upon return to Earth.

  16. The Adhesion Mechanism of Marine Mussel Foot Protein: Adsorption of L-Dopa on α- and β-Cristobalite Silica Using Density Functional Theory

    Directory of Open Access Journals (Sweden)

    Shabeer Ahmad Mian

    2017-01-01

    Full Text Available Marine mussels strongly adhere to various surfaces and endure their attachment under a variety of conditions. In order to understand the basic mechanism involved, we study the adsorption of L-dopa molecule on hydrophilic geminal and terminal isolated silanols of silica (001 surface. High content of modified amino acid L-dopa is found in the glue-like material secreted by the mussels through which it sticks to various surfaces under water. To understand the adsorption behavior, we have made use of periodic Density Functional Theory (DFT study. The L-dopa molecule adheres to silica surfaces terminated with geminal and terminal silanols via its catechol part. In both cases, the adhesion is achieved through the formation of 4 H-bonds. A binding energy of 29.48 and 31.67 kcal/mol has been estimated, after the inclusion of dispersion energy, for geminal and terminal silanols of silica, respectively. These results suggest a relatively stronger adhesion of dopa molecule for surface with terminal isolated silanols.

  17. Similarities and Differences of the Soleus and Gastrocnemius H-reflexes during Varied Body Postures, Foot Positions, and Muscle Function: Multifactor Designs for Repeated Measures

    Directory of Open Access Journals (Sweden)

    Sabbahi Mohamed A

    2011-06-01

    Full Text Available Abstract Background Although the soleus (Sol, medial gastrocnemius (MG, and lateral gastrocnemius (LG muscles differ in function, composition, and innervations, it is a common practice is to investigate them as single H-reflex recording. The purpose of this study was to compare H-reflex recordings between these three sections of the triceps surae muscle group of healthy participants while lying and standing during three different ankle positions. Methods The Sol, MG and LG muscles' H-reflexes were recorded from ten participants during prone lying and standing with the ankle in neutral, maximum dorsiflexion, and maximum plantarflexion positions. Four traces were averaged for each combination of conditions. Three-way ANOVAs (posture X ankle position X muscle with planned comparisons were used for statistical comparisons. Results Although the H-reflex in the three muscle sections differed in latency and amplitude, its dependency on posture and ankle position was similar. The H-reflex amplitudes and maximum H-reflex to M-response (H/M ratios were significantly 1 lower during standing compared to lying with the ankle in neutral, 2 greater during standing with the ankle in plantarflexion compared to neutral, and 3 less with the ankle in dorsiflexion compared to neutral during lying and standing for all muscles (p ≤ .05. Conclusion Varying demands are required for muscles activated during distinctly different postures and ankle movement tasks.

  18. Changes in foot pressure elicited by 3D air balance exercise and pelvic stability exercise for functional leg-length discrepancy in adult women.

    Science.gov (United States)

    Lee, Byung-Hoon; Kim, Jeong-Ja; Kim, Chan-Kyu

    2015-03-01

    [Purpose] This study was conducted to examine the effect of pelvic stabilization exercise and 3D equipment exercise on adult women with Functional Leg-Length Discrepancy (FLLD). [Subjects and Methods] Twenty female students in their 20's having FLLD without Structural Leg Length Discrepancy were selected. Exercise was performed for 50 min per session, three times a week, for six weeks. The Pelvic stabilization exercise (PSE) group performed pelvic stabilization exercises for 50 minutes, and the 3D exercise (3DE) group performed 3D Air Balance exercise for 10 minutes after performing the pelvic stabilization exercise program for 40 minutes. [Results] The PSE group showed statistically significant differences in tape measure method (TMM) and maximum pressure between pre-test and post-test, and 3DE showed statistically significant differences in TMM, the difference in maximum pressure, the difference in average pressure, and the difference in support area. At the end of the 6-week intervention, TMM, difference in maximum pressure, difference in average pressure, and difference in support area showed significantly greater reduction in the 3DE group. [Conclusion] The results show that 3D stabilization exercise was more effective at improving the stabilization of the deep muscles surrounding the pelvis and left-right muscular balance. We consider that 3D exercise should be included in exercise programs for improving pelvic cavity and spinal stability in the future.

  19. [Operative treatment of diabetic foot].

    Science.gov (United States)

    Hintermann, B

    1999-07-08

    The majority of diabetic foot ulcers are the results of repetitive pressure that exceeds the threshold of soft-tissue tolerance, leading to mechanical destruction of the tissue. Progression of plantar ulcers can rapidly lead to osteomyelitis that may result in loss of the foot through amputation. In order to prevent such a disaster, surgical treatment should be taken into consideration when conservative treatment remains without success. The goal of surgical treatment of an infected ulcer is debridement of the soft-tissue and removal of the underlying pressure by careful bone resection or correction of a deformity by arthrodesis. Various authors have recently reported successful surgical reconstruction of neuroarthropathic foot deformity and instability. Apparently arthrodesis is a viable alternative to amputation for patients with unstable deformity or recurrent ulceration. Proper preoperative evaluation is mandatory. The indications are not well defined yet.

  20. Coordination of intrinsic and extrinsic foot muscles during walking.

    Science.gov (United States)

    Zelik, Karl E; La Scaleia, Valentina; Ivanenko, Yuri P; Lacquaniti, Francesco

    2015-04-01

    The human foot undergoes complex deformations during walking due to passive tissues and active muscles. However, based on prior recordings it is unclear if muscles that contribute to flexion/extension of the metatarsophalangeal (MTP) joints are activated synchronously to modulate joint impedance, or sequentially to perform distinct biomechanical functions. We investigated the coordination of MTP flexors and extensors with respect to each other, and to other ankle-foot muscles. We analyzed surface electromyographic (EMG) recordings of intrinsic and extrinsic foot muscles for healthy individuals during level treadmill walking, and also during sideways and tiptoe gaits. We computed stride-averaged EMG envelopes and used the timing of peak muscle activity to assess synchronous vs. sequential coordination. We found that peak MTP flexor activity occurred significantly before peak MTP extensor activity during walking (P walking tended to dissociate during other locomotor tasks. For instance, extensor hallucis brevis and extensor digitorum brevis muscle activation peaks decoupled during sideways gait. The sequential peak activity of MTP flexors followed by MTP extensors suggests that their biomechanical contributions may be largely separable from each other and from other extrinsic foot muscles during walking. Meanwhile, the task-specific coordination of the foot muscles during other modes of locomotion indicates a high-level of specificity in their function and control.

  1. Pipeline for inferring protein function from dynamics using coarse-grained molecular mechanics forcefield.

    Science.gov (United States)

    Bhadra, Pratiti; Pal, Debnath

    2017-02-24

    Dynamics is integral to the function of proteins, yet the use of molecular dynamics (MD) simulation as a technique remains under-explored for molecular function inference. This is more important in the context of genomics projects where novel proteins are determined with limited evolutionary information. Recently we developed a method to match the query protein's flexible segments to infer function using a novel approach combining analysis of residue fluctuation-graphs and auto-correlation vectors derived from coarse-grained (CG) MD trajectory. The method was validated on a diverse dataset with sequence identity between proteins as low as 3%, with high function-recall rates. Here we share its implementation as a publicly accessible web service, named DynFunc (Dynamics Match for Function) to query protein function from ≥1 µs long CG dynamics trajectory information of protein subunits. Users are provided with the custom-developed coarse-grained molecular mechanics (CGMM) forcefield to generate the MD trajectories for their protein of interest. On upload of trajectory information, the DynFunc web server identifies specific flexible regions of the protein linked to putative molecular function. Our unique application does not use evolutionary information to infer molecular function from MD information and can, therefore, work for all proteins, including moonlighting and the novel ones, whenever structural information is available. Our pipeline is expected to be of utility to all structural biologists working with novel proteins and interested in moonlighting functions.

  2. Autonomic neuropathy and diabetic foot ulceration.

    Science.gov (United States)

    Edmonds, M E; Nicolaides, K H; Watkins, P J

    1986-01-01

    Autonomic function was studied in three groups of insulin-dependent diabetic patients. Heart rate changes during deep breathing and on standing were significantly less in 28 patients with a recent history of foot ulceration compared with 40 patients with peripheral neuropathy but without ulceration (p less than 0.001) and 54 patients without neuropathy (p less than 0.001). Sympathetic function was assessed in 36 of these patients from peripheral arterial diastolic flow patterns obtained by Doppler ultrasound measurements and expressed as the pulsatility index (PI). Patients with a history of ulceration (n = 10) showed considerably increased diastolic flow (PI = 4.28 +/- 0.53, mean +/- S.E.M.) compared with 12 neuropathic patients with no history of ulceration (PI = 7.80 +/- 0.68, p less than 0.002) and 14 patients without neuropathy (PI = 9.55 +/- 0.89, p less than 0.002). Severely abnormal autonomic function occurs in association with neuropathic foot ulceration, but patients without ulcers have lesser degrees of autonomic neuropathy, thus a causal relationship has not been established.

  3. The Charcot foot in diabetes.

    Science.gov (United States)

    Rogers, Lee C; Frykberg, Robert G; Armstrong, David G; Boulton, Andrew J M; Edmonds, Michael; Van, Georges Ha; Hartemann, Agnes; Game, Frances; Jeffcoate, William; Jirkovska, Alexandra; Jude, Edward; Morbach, Stephan; Morrison, William B; Pinzur, Michael; Pitocco, Dario; Sanders, Lee; Wukich, Dane K; Uccioli, Luigi

    2011-09-01

    The diabetic Charcot foot syndrome is a serious and potentially limb-threatening lower-extremity complication of diabetes. First described in 1883, this enigmatic condition continues to challenge even the most experienced practitioners. Now considered an inflammatory syndrome, the diabetic Charcot foot is characterized by varying degrees of bone and joint disorganization secondary to underlying neuropathy, trauma, and perturbations of bone metabolism. An international task force of experts was convened by the American Diabetes Association and the American Podiatric Medical Association in January 2011 to summarize available evidence on the pathophysiology, natural history, presentations, and treatment recommendations for this entity.

  4. Interacting relativistic quantum dynamics for multi-time wave functions

    Directory of Open Access Journals (Sweden)

    Lienert Matthias

    2016-01-01

    Full Text Available In this paper, we report on recent progress about a rigorous and manifestly covariant interacting model for two Dirac particles in 1+1 dimensions [9, 10]. It is formulated using the multi-time formalism of Dirac, Tomonaga and Schwinger. The mechanism of interaction is a relativistic generalization of contact interactions, and it is achieved going beyond the usual functional-analytic Hamiltonian method.

  5. Interacting relativistic quantum dynamics for multi-time wave functions

    Science.gov (United States)

    Lienert, Matthias

    2016-11-01

    In this paper, we report on recent progress about a rigorous and manifestly covariant interacting model for two Dirac particles in 1+1 dimensions [9, 10]. It is formulated using the multi-time formalism of Dirac, Tomonaga and Schwinger. The mechanism of interaction is a relativistic generalization of contact interactions, and it is achieved going beyond the usual functional-analytic Hamiltonian method.

  6. Relationship between ankle-hind foot function and calcaneal three-dimensional morphological parameters%跟骨三维形态学参数与踝后足功能的关系

    Institute of Scientific and Technical Information of China (English)

    许灿; 李明清; 李康华; 刘华

    2016-01-01

    背景:跟骨整体形态与后距下关节面解剖对位都是跟骨关节内骨折手术治疗的重要预后因素,但当前仍缺少系统的生物力学实验证实跟骨三维形态学参数对于踝-后足功能的重要性。目的:综合利用实体实验与数值分析方法,明确跟骨三维形态学参数与踝后足功能的相关性。方法:首先使用人体踝足尸体标本构建跟骨高度、宽度和长度异常模型,通过生物力学加载支架对各组模型进行加载,分析跟骨高度丢失、宽度增加和长度短缩模型的动力学数据。进而构建正常人体踝后足有限元模型,在其基础上建立跟骨高度丢失、宽度增加和长度短缩数值模型,计算后距下关节面的接触特征。结果与结论:①跟骨宽度增加和长度短缩会部分限制踝后足的活动度,跟骨高度丢失则会引起距下关节活动度增加;②跟骨宽度增加会增加距下关节的接触面积,高度丢失会减少距下关节的接触面积,并使关节应力中心向关节面前下方移动;③跟骨三维形态学参数的改变会导致踝后足生物力学异常,因此跟骨骨折修复治疗中应当细致恢复跟骨的整体形态。%BACKGROUND:Both the overal appearance of the calcaneus and anatomical reduction of posterior subtalar joint are important prognostic factors of calcaneal intra-articular fracture repair. However, there is a lack of biomechanical data supporting the clinical importance of calcaneus height, length and heel width for the ankle-hind foot function. OBJECTIVE:To determine the correlation of the three-dimensional morphological parameters with the ankle-hind foot biomechanics as determined by the entity experiment and numerical analysis. METHODS:Models of abnormal calcaneus height, length and width were constructed in the human cadaveric feet and underwent a biomechanical load. The kinematics of the ankle-hind foot were compared between normal and

  7. Recovery of methanotrophs from disturbance: population dynamics, evenness and functioning.

    Science.gov (United States)

    Ho, Adrian; Lüke, Claudia; Frenzel, Peter

    2011-04-01

    Biodiversity is claimed to be essential for ecosystem functioning, but is threatened by anthropogenic disturbances. Prokaryotes have been assumed to be functionally redundant and virtually inextinguishable. However, recent work indicates that microbes may well be sensitive to environmental disturbance. Focusing on methane-oxidizing bacteria as model organisms, we simulated disturbance-induced mortality by mixing native with sterilized paddy soil in two ratios, 1:4 and 1:40, representing moderate and severe die-offs. Disturbed microcosms were compared with an untreated control. Recovery of activity and populations was followed over 4 months by methane uptake measurements, pmoA-qPCR, pmoA-based terminal restriction fragment length polymorphism and a pmoA-based diagnostic microarray. Diversity and evenness of methanotrophs decreased in disturbed microcosms, but functioning was not compromised. We consistently observed distinctive temporal shifts between type I and type II methanotrophs, and a rapid population growth leading to even higher cell numbers comparing disturbed microcosms with the control. Overcompensating mortality suggested that population size in the control was limited by competition with other bacteria. Overall, methanotrophs showed a remarkable ability to compensate for die-offs.

  8. Linearization models for parabolic dynamical systems via Abel's functional equation

    CERN Document Server

    Elin, Mark; Reich, Simeon; Shoikhet, David

    2009-01-01

    We study linearization models for continuous one-parameter semigroups of parabolic type. In particular, we introduce new limit schemes to obtain solutions of Abel's functional equation and to study asymptotic behavior of such semigroups. The crucial point is that these solutions are univalent functions convex in one direction. In a parallel direction, we find analytic conditions which determine certain geometric properties of those functions, such as the location of their images in either a half-plane or a strip, and their containing either a half-plane or a strip. In the context of semigroup theory these geometric questions may be interpreted as follows: is a given one-parameter continuous semigroup either an outer or an inner conjugate of a group of automorphisms? In other words, the problem is finding a fractional linear model of the semigroup which is defined by a group of automorphisms of the open unit disk. Our results enable us to establish some new important analytic and geometric characteristics of t...

  9. Diabetic foot ulcers: practical treatment recommendations.

    Science.gov (United States)

    Edmonds, Michael

    2006-01-01

    When treating diabetic foot ulcers it is important to be aware of the natural history of the diabetic foot, which can be divided into five stages: stage 1, a normal foot; stage 2, a high risk foot; stage 3, an ulcerated foot; stage 4, an infected foot; and stage 5, a necrotic foot. This covers the entire spectrum of foot disease but emphasises the development of the foot ulcer as a pivotal event in stage 3, which demands urgent and aggressive management. Diabetic foot care in all stages needs multidisciplinary management to control mechanical, wound, microbiological, vascular, metabolic and educational aspects. Achieving good metabolic control of blood glucose, lipids and blood pressure is important in each stage, as is education to teach proper foot care appropriate for each stage. Ideally, it is important to prevent the development of ulcers in stages 1 and 2. In stage 1, the normal foot, it is important to encourage the use of suitable footwear, and to educate the patient to promote healthy foot care and footwear habits. In stage 2, the foot has developed one or more of the following risk factors for ulceration: neuropathy, ischaemia, deformity, swelling and callus. The majority of deformities can be accommodated in special footwear and as callus is an important precursor of ulceration it should be treated aggressively, especially in the neuropathic foot. In stage 3, ulcers can be divided into two distinct entities: those in the neuropathic foot and those in the neuroischaemic foot. In the neuropathic foot, ulcers commonly develop on the plantar surface of the foot and the toes, and are associated with neglected callus and high plantar pressures. In the neuroischaemic foot, ulcers are commonly seen around the edges of the foot, including the apices of the toes and back of the heel, and are associated with trauma or wearing unsuitable shoes. Ulcers in stage 3 need relief of pressure (mechanical control), sharp debridement and dressings (wound control), and

  10. Dynamic soil-structure interaction of monopod and polypod foundations

    DEFF Research Database (Denmark)

    Andersen, Lars Vabbersgaard

    2016-01-01

    The paper concerns the importance of through–soil coupling for structures having foundations with more footings. First, a model for dynamic analysis of polypod footings is established in the frequency domain, employing Green’s function for wave propagation in a layered half-space. To allow analysis...... manner. As a computational example, the dynamic response of a plane frame structure with two footings is compared for two cases: one with and one without the cross coupling. Homogeneous as well as layered soil is considered....... within the time domain, frequency-independent lumped-parameter models are developed. The paper proposes a decision criterion for determination of which components must be included within a lumped-parameter model in order to account for the structure–soil–structure interaction in an adequate and efficient...

  11. Dynamic soil-structure interaction of monopod and polypod foundations

    DEFF Research Database (Denmark)

    Andersen, Lars Vabbersgaard

    2016-01-01

    within the time domain, frequency-independent lumped-parameter models are developed. The paper proposes a decision criterion for determination of which components must be included within a lumped-parameter model in order to account for the structure–soil–structure interaction in an adequate and efficient......The paper concerns the importance of through–soil coupling for structures having foundations with more footings. First, a model for dynamic analysis of polypod footings is established in the frequency domain, employing Green’s function for wave propagation in a layered half-space. To allow analysis...... manner. As a computational example, the dynamic response of a plane frame structure with two footings is compared for two cases: one with and one without the cross coupling. Homogeneous as well as layered soil is considered....

  12. Microfluidic strategy to investigate dynamics of small blood vessel function

    Science.gov (United States)

    Yasotharan, Sanjesh; Bolz, Steffen-Sebastian; Guenther, Axel

    2010-11-01

    Resistance arteries (RAs, 30-300 microns in diameter) that are located within the terminal part of the vascular tree regulate the laminar perfusion of tissue with blood, via the peripheral vascular resistance, and hence controls the systemic blood pressure. The structure of RAs is adapted to actively controlling flow resistance by dynamically changing their diameter, which is non-linearly dependent on the temporal variation of the transmural pressure, perfusion flow rate and spatiotemporal changes in the chemical environment. Increases in systemic blood pressure (hypertension) resulting from pathologic changes in the RA response represent the primary risk factor for cardiovascular diseases. We use a microfluidic strategy to investigate small blood vessels by quantifying structural variations within the arterial wall, RA outer contour and diameter over time. First, we document the artery response to vasomotor drugs that were homogeneously applied at step-wise increasing concentration. Second, we investigate the response in the presence of well-defined axial and circumferential heterogeneities. Artery per- and superfusion is discussed based on microscale PIV measurements of the fluid velocity on both sides of the arterial wall. Structural changes in the arterial wall are quantified using cross-correlation and proper orthogonal decomposition analyses of bright-field micrographs.

  13. Functional verification of dynamically reconfigurable FPGA-based systems

    CERN Document Server

    Gong, Lingkan

    2015-01-01

    This book analyzes the challenges in verifying Dynamically Reconfigurable Systems (DRS) with respect to the user design and the physical implementation of such systems. The authors describe the use of a simulation-only layer to emulate the behavior of target FPGAs and accurately model the characteristic features of reconfiguration. Readers are enabled with this simulation-only layer to maintain verification productivity by abstracting away the physical details of the FPGA fabric.  Two implementations of the simulation-only layer are included: Extended ReChannel is a SystemC library that can be used to check DRS designs at a high level; ReSim is a library to support RTL simulation of a DRS reconfiguring both its logic and state. Through a number of case studies, the authors demonstrate how their approach integrates seamlessly with existing, mainstream DRS design flows and with well-established verification methodologies such as top-down modeling and coverage-driven verification. Provides researchers with an i...

  14. Nonlinear MHD waves in a Prominence Foot

    CERN Document Server

    Ofman, Leon; Kucera, Therese; Schmieder, Brigitte

    2015-01-01

    We study nonlinear waves in a prominence foot using 2.5D MHD model motivated by recent high-resolution observations with Hinode/SOT in Ca~II emission of a prominence on October 10, 2012 showing highly dynamic small-scale motions in the prominence material. Observations of H$\\alpha$ intensities and of Doppler shifts show similar propagating fluctuations. However the optically thick nature of the emission lines inhibits unique quantitative interpretation in terms of density. Nevertheless, we find evidence of nonlinear wave activity in the prominence foot by examining the relative magnitude of the fluctuation intensity ($\\delta I/I\\sim \\delta n/n$). The waves are evident as significant density fluctuations that vary with height, and apparently travel upward from the chromosphere into the prominence material with quasi-periodic fluctuations with typical period in the range of 5-11 minutes, and wavelengths $\\sim <$2000 km. Recent Doppler shift observations show the transverse displacement of the propagating wav...

  15. The dynamic dielectric at a brain functional site and an EM wave approach to functional brain imaging.

    Science.gov (United States)

    Li, X P; Xia, Q; Qu, D; Wu, T C; Yang, D G; Hao, W D; Jiang, X; Li, X M

    2014-11-04

    Functional brain imaging has tremendous applications. The existing methods for functional brain imaging include functional Magnetic Resonant Imaging (fMRI), scalp electroencephalography (EEG), implanted EEG, magnetoencephalography (MEG) and Positron Emission Tomography (PET), which have been widely and successfully applied to various brain imaging studies. To develop a new method for functional brain imaging, here we show that the dielectric at a brain functional site has a dynamic nature, varying with local neuronal activation as the permittivity of the dielectric varies with the ion concentration of the extracellular fluid surrounding neurons in activation. Therefore, the neuronal activation can be sensed by a radiofrequency (RF) electromagnetic (EM) wave propagating through the site as the phase change of the EM wave varies with the permittivity. Such a dynamic nature of the dielectric at a brain functional site provides the basis for an RF EM wave approach to detecting and imaging neuronal activation at brain functional sites, leading to an RF EM wave approach to functional brain imaging.

  16. Probing molecular mechanisms of the Hsp90 chaperone: biophysical modeling identifies key regulators of functional dynamics.

    Directory of Open Access Journals (Sweden)

    Anshuman Dixit

    Full Text Available Deciphering functional mechanisms of the Hsp90 chaperone machinery is an important objective in cancer biology aiming to facilitate discovery of targeted anti-cancer therapies. Despite significant advances in understanding structure and function of molecular chaperones, organizing molecular principles that control the relationship between conformational diversity and functional mechanisms of the Hsp90 activity lack a sufficient quantitative characterization. We combined molecular dynamics simulations, principal component analysis, the energy landscape model and structure-functional analysis of Hsp90 regulatory interactions to systematically investigate functional dynamics of the molecular chaperone. This approach has identified a network of conserved regions common to the Hsp90 chaperones that could play a universal role in coordinating functional dynamics, principal collective motions and allosteric signaling of Hsp90. We have found that these functional motifs may be utilized by the molecular chaperone machinery to act collectively as central regulators of Hsp90 dynamics and activity, including the inter-domain communications, control of ATP hydrolysis, and protein client binding. These findings have provided support to a long-standing assertion that allosteric regulation and catalysis may have emerged via common evolutionary routes. The interaction networks regulating functional motions of Hsp90 may be determined by the inherent structural architecture of the molecular chaperone. At the same time, the thermodynamics-based "conformational selection" of functional states is likely to be activated based on the nature of the binding partner. This mechanistic model of Hsp90 dynamics and function is consistent with the notion that allosteric networks orchestrating cooperative protein motions can be formed by evolutionary conserved and sparsely connected residue clusters. Hence, allosteric signaling through a small network of distantly connected

  17. Structural and Dynamic Process Family Risk Factors: Consequences for Holistic Adolescent Functioning

    Science.gov (United States)

    Matjasko, Jennifer L.; Grunden, Leslie N.; Ernst, Jody L.

    2007-01-01

    This study utilized a dynamic cumulative family risk model to explain changes in adolescent functioning. We used a person-centered approach to detect patterns of academic, emotional, and behavioral functioning and the stability of these patterns using two waves of the National Longitudinal Study of Adolescent Health (N = 10,173). Four adjustment…

  18. Localized Template-Driven Functionalization of Nanoparticles by Dynamic Combinatorial Chemistry

    NARCIS (Netherlands)

    Nowak, Piotr; Saggiomo, Vittorio; Salehian, Fatemeh; Colomb-Delsuc, Mathieu; Han, Yang; Otto, Sijbren

    2015-01-01

    We have developed a method for the localized functionalization of gold nanoparticles using imine-based dynamic combinatorial chemistry. By using DNA templates, amines were grafted on the aldehyde-functionalized nanoparticles only if and where the nanoparticles interacted with the template molecules.

  19. Localized Template-Driven Functionalization of Nanoparticles by Dynamic Combinatorial Chemistry

    NARCIS (Netherlands)

    Nowak, Piotr; Saggiomo, Vittorio; Salehian, Fatemeh; Colomb-Delsuc, Mathieu; Han, Yang; Otto, Sijbren

    2015-01-01

    We have developed a method for the localized functionalization of gold nanoparticles using imine-based dynamic combinatorial chemistry. By using DNA templates, amines were grafted on the aldehyde-functionalized nanoparticles only if and where the nanoparticles interacted with the template molecules.

  20. Structural and functional dynamics of Excitatory Amino Acid Transporters (EAAT

    Directory of Open Access Journals (Sweden)

    Thomas Rauen

    2014-09-01

    Full Text Available Glutamate transporters control the glutamate homeostasis in the central nervous system, and, thus, are not only crucial for physiological excitatory synaptic signaling, but also for the prevention of a large number of neurodegenerative diseases that are associated with excessive and prolonged presence of the neurotransmitter glutamate in the extracellular space. Until now, five subtypes of high-affinity glutamate transporters (excitatory amino acid transporters, EAATs 1–5 have been identified. These 5 high-affinity glutamate transporter subtypes belong to the solute carrier 1 (SLC1 family of transmembrane proteins: EAAT1/GLAST (SLC1A3, EAAT2/GLT1 (SLC1A2, EAAT3/EAAC1 (SLC1A1, EAAT4 (SLC1A6 and EAAT5 (SLC1A7. EAATs are secondary-active transporters, taking up glutamate into the cell against a substantial concentration gradient. The driving force for concentrative uptake is provided by the co-transport of Na+ ions and the counter-transport of one K+ in a step independent of the glutamate translocation step. Due to the electrogenicity of transport, the transmembrane potential can also act as driving force. Glutamate transporters are also able to run in reverse, resulting in glutamate release from cells. Due to these important physiological functions, glutamate transporter expression and, therefore, the transport rate, are tightly regulated. The EAAT protein family are structurally expected to be highly similar, however, these transporters show a functional diversity that ranges from high capacity glutamate uptake systems (EAATs 1–3 to receptor-like glutamate activated anion channels (EAATs 4–5. Here, we provide an update on most recent progress made on EAAT’s molecular transport mechanism, structure-function relationships, pharmacology, and will add recent insights into mechanism of rapid membrane trafficking of glutamate transporters.

  1. Spontaneous Functional Network Dynamics and Associated Structural Substrates in the Human Brain

    Directory of Open Access Journals (Sweden)

    Xuhong eLiao

    2015-09-01

    Full Text Available Recent imaging connectomics studies have demonstrated that the spontaneous human brain functional networks derived from resting-state functional MRI (R-fMRI include many non-trivial topological properties, such as highly efficient small-world architecture and densely connected hub regions. However, very little is known about dynamic functional connectivity (D-FC patterns of spontaneous human brain networks during rest and about how these spontaneous brain dynamics are constrained by the underlying structural connectivity. Here, we combined sub-second multiband R-fMRI data with graph-theoretical approaches to comprehensively investigate the dynamic characteristics of the topological organization of human whole-brain functional networks, and then employed diffusion imaging data in the same participants to further explore the associated structural substrates. At the connection level, we found that human whole-brain D-FC patterns spontaneously fluctuated over time, while homotopic D-FC exhibited high connectivity strength and low temporal variability. At the network level, dynamic functional networks exhibited time-varying but evident small-world and assortativity architecture, with several regions (e.g., insula, sensorimotor cortex and medial prefrontal cortex emerging as functionally persistent hubs (i.e., highly connected regions while possessing large temporal variability in their degree centrality. Finally, the temporal characteristics (i.e., strength and variability of the connectional and nodal properties of the dynamic brain networks were significantly associated with their structural counterparts. Collectively, we demonstrate the economical, efficient and flexible characteristics of dynamic functional coordination in large-scale human brain networks during rest, and highlight their relationship with underlying structural connectivity, which deepens our understandings of spontaneous brain network dynamics in humans.

  2. Hand or foot spasms

    Science.gov (United States)

    ... panic Muscle cramps , usually caused by overuse during sports or work activity Pregnancy, more often during the ... be done. Tests may include: Potassium, calcium and magnesium levels Hormone levels Kidney function tests Vitamin D ...

  3. Uniformly Almost Periodic Functions and Almost Periodic Solutions to Dynamic Equations on Time Scales

    Directory of Open Access Journals (Sweden)

    Yongkun Li

    2011-01-01

    Full Text Available Firstly, we propose a concept of uniformly almost periodic functions on almost periodic time scales and investigate some basic properties of them. When time scale T=ℝ or ℤ, our definition of the uniformly almost periodic functions is equivalent to the classical definitions of uniformly almost periodic functions and the uniformly almost periodic sequences, respectively. Then, based on these, we study the existence and uniqueness of almost periodic solutions and derive some fundamental conditions of admitting an exponential dichotomy to linear dynamic equations. Finally, as an application of our results, we study the existence of almost periodic solutions for an almost periodic nonlinear dynamic equations on time scales.

  4. Diabetic Foot - Multiple Languages: MedlinePlus

    Science.gov (United States)

    ... Are Here: Home → Multiple Languages → All Health Topics → Diabetic Foot URL of this page: https://medlineplus.gov/languages/ ... V W XYZ List of All Topics All Diabetic Foot - Multiple Languages To use the sharing features on ...

  5. 130 DIABETIC FOOT ULCERS: CURRENT TRENDS IN ...

    African Journals Online (AJOL)

    drclement

    achieved in the treatment of diabetic foot ulcers in ... Fig II: WAGNER CLASSIFICATION OF DIABETIC FOOT ULCERS. Grade 0 .... to surgeries for correcting deformities .... Seamless socks and socks with flat, unobtrusive, soft seams should.

  6. Max-Sum Diversification, Monotone Submodular Functions and Dynamic Updates

    CERN Document Server

    Borodin, Allan; Ye, Yuli

    2012-01-01

    Result diversification has many important applications in databases, operations research, information retrieval, and finance. In this paper, we study and extend a particular version of result diversification, known as max-sum diversification. More specifically, we consider the setting where we are given a set of elements in a metric space and a set valuation function $f$ defined on every subset. For any given subset $S$, the overall objective is a linear combination of $f(S)$ and the sum of the distances induced by $S$. The goal is to find a subset $S$ satisfying some constraints that maximizes the overall objective. This problem is first studied by Gollapudi and Sharma for modular set functions and for sets satisfying a cardinality constraint. We consider an extension of the modular case to the monotone submodular case, for which the previous algorithm no longer applies. Interestingly, we are able to match the 2-approximation using a natural, but different greedy algorithm. We then further extend the problem...

  7. Dynamic functional brain networks involved in simple visual discrimination learning.

    Science.gov (United States)

    Fidalgo, Camino; Conejo, Nélida María; González-Pardo, Héctor; Arias, Jorge Luis

    2014-10-01

    Visual discrimination tasks have been widely used to evaluate many types of learning and memory processes. However, little is known about the brain regions involved at different stages of visual discrimination learning. We used cytochrome c oxidase histochemistry to evaluate changes in regional brain oxidative metabolism during visual discrimination learning in a water-T maze at different time points during training. As compared with control groups, the results of the present study reveal the gradual activation of cortical (prefrontal and temporal cortices) and subcortical brain regions (including the striatum and the hippocampus) associated to the mastery of a simple visual discrimination task. On the other hand, the brain regions involved and their functional interactions changed progressively over days of training. Regions associated with novelty, emotion, visuo-spatial orientation and motor aspects of the behavioral task seem to be relevant during the earlier phase of training, whereas a brain network comprising the prefrontal cortex was found along the whole learning process. This study highlights the relevance of functional interactions among brain regions to investigate learning and memory processes. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Effective model hierarchies for dynamic and static classical density functional theories

    Energy Technology Data Exchange (ETDEWEB)

    Majaniemi, S [Department of Applied Physics, Aalto University School of Science and Technology, PO Box 11100, FI-00076 Aalto (Finland); Provatas, N [Department of Materials Science and Engineering, McMaster University, 1280 Main Street West, Hamilton, ON, L8S-4L7 (Canada); Nonomura, M, E-mail: maj@fyslab.hut.f [Department of Physics, Graduate School of Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan)

    2010-09-15

    The origin and methodology of deriving effective model hierarchies are presented with applications to solidification of crystalline solids. In particular, it is discussed how the form of the equations of motion and the effective parameters on larger scales can be obtained from the more microscopic models. It will be shown that tying together the dynamic structure of the projection operator formalism with static classical density functional theories can lead to incomplete (mass) transport properties even though the linearized hydrodynamics on large scales is correctly reproduced. To facilitate a more natural way of binding together the dynamics of the macrovariables and classical density functional theory, a dynamic generalization of density functional theory based on the nonequilibrium generating functional is suggested.

  9. Find an Orthopaedic Foot and Ankle MD/DO

    Science.gov (United States)

    ... Content AOFAS / FootCareMD / Find a Surgeon Find an Orthopaedic Foot & Ankle Surgeon Page Content The Orthopaedic Distinction Who are Orthopaedic Foot & Ankle Surgeons? Orthopaedic foot and ankle surgeons ...

  10. An overview of the Charcot foot pathophysiology

    OpenAIRE

    Öğüt, Tahir; Kaynak, Gökhan; Birsel, Olgar; Güven, Mehmet Fatih

    2013-01-01

    Charcot arthropathy of the foot is a rare but devastating complication of diabetes that remains to be a challenging issue for the foot and ankle surgeons. Charcot foot fails to be an obvious diagnostic option that comes to mind, even in a pathognomonic clinical appearance. The rarity of the disorder, more common pathologies that mimic the condition, and the self-limiting prognosis deviate the clinician from the right diagnosis. The clinical challenges in the diagnosis of Charcot foot require ...

  11. [Spastic equinus foot].

    Science.gov (United States)

    Westhoff, B; Weimann-Stahlschmidt, K; Krauspe, R

    2011-07-01

    Pes equinus is the most common deformity in cerebral palsy. A primarily dynamic pes equinus without shortening of the calf muscle in many cases turns into a structural pes equinus. This is due to insufficient linear growth of the calf muscle compared to bone growth. Structural pes equinus has to be distinguished from marked, compensatory and forefoot pes equinus. Conservative as well as operative treatment options are often applied in combination or sequentially. In dynamic pes equinus botulinum toxin A is the therapy of choice. Only slight structural pes equinus may improve under botulinum toxin A injection with and without additional casting. Usually, structural pes equinus requires operative treatment or lengthening of the gastrocnemius and/or soleus muscle (operation according to Baumann). Because of its side effect of inducing loss of power of the calf muscle, lengthening of the Achilles tendon should only be performed with caution. Especially in bilateral spastic cerebral palsy, the increased risk of causing talipes calcaneovalgus and crouch gait has to be considered.

  12. The dynamical system generated by the 3n+1 function

    CERN Document Server

    Wirsching, Günther J

    1998-01-01

    The 3n+1 function T is defined by T(n)=n/2 for n even, and T(n)=(3n+1)/2 for n odd. The famous 3n+1 conjecture, which remains open, states that, for any starting number n>0, iterated application of T to n eventually produces 1. After a survey of theorems concerning the 3n+1 problem, the main focus of the book are 3n+1 predecessor sets. These are analyzed using, e.g., elementary number theory, combinatorics, asymptotic analysis, and abstract measure theory. The book is written for any mathematician interested in the 3n+1 problem, and in the wealth of mathematical ideas employed to attack it.

  13. Behavior of the Escape Rate Function in Hyperbolic Dynamical Systems

    CERN Document Server

    Demers, Mark

    2011-01-01

    For a fixed initial reference measure, we study the dependence of the escape rate on the hole for a smooth or piecewise smooth hyperbolic map. First, we prove the existence and Holder continuity of the escape rate for systems with small holes admitting Young towers. Then we consider general holes for Anosov diffeomorphisms, without size or Markovian restrictions. We prove bounds on the upper and lower escape rates using the notion of pressure on the survivor set and show that a variational principle holds under generic conditions. However, we also show that the escape rate function forms a devil's staircase with jumps along sequences of regular holes and present examples to elucidate some of the difficulties involved in formulating a general theory.

  14. Neural network design for J function approximation in dynamic programming

    CERN Document Server

    Pang, X

    1998-01-01

    This paper shows that a new type of artificial neural network (ANN) -- the Simultaneous Recurrent Network (SRN) -- can, if properly trained, solve a difficult function approximation problem which conventional ANNs -- either feedforward or Hebbian -- cannot. This problem, the problem of generalized maze navigation, is typical of problems which arise in building true intelligent control systems using neural networks. (Such systems are discussed in the chapter by Werbos in K.Pribram, Brain and Values, Erlbaum 1998.) The paper provides a general review of other types of recurrent networks and alternative training techniques, including a flowchart of the Error Critic training design, arguable the only plausible approach to explain how the brain adapts time-lagged recurrent systems in real-time. The C code of the test is appended. As in the first tests of backprop, the training here was slow, but there are ways to do better after more experience using this type of network.

  15. Foot Health Facts for Athletes

    Science.gov (United States)

    ... as basketball, can lead to tears and even ruptures of the Achilles tendon. These conditions should be followed by a foot and ankle surgeon. Heel pain —This condition is most often caused by plantar fasciitis, although other things, such as stress fractures or ...

  16. Mobility and Balance and Their Correlation with Physiological Factors in Elderly with Different Foot Postures

    Directory of Open Access Journals (Sweden)

    Aisyah Mohd Said

    2015-01-01

    Full Text Available This study determines (1 the correlation between mobility and balance performances with physiological factors and (2 the relationship between foot postures with anthropometric characteristics and lower limb characteristics among elderly with neutral, pronated, and supinated foot. A cross-sectional observational study was conducted in community-dwelling elderly (age: 69.86 ± 5.62 years. Participants were grouped into neutral (n=16, pronated (n=14, and supinated (n=14 foot based on the foot posture index classification. Anthropometric data (height, weight, and BMI, lower limb strength (5-STS and endurance (30 s chair rise test, mobility (TUG, and balance (FSST were determined. Data were analyzed using Spearman’s correlation coefficient. Body weight was negatively and moderately correlated (rs=-0.552, P<0.05 with mobility in supinated foot; moderate-to-high positive linear rank correlation was found between lower limb strength and mobility (rs=0.551 to 0.804, P<0.05 for pronated and neutral foot. Lower limb endurance was negatively and linearly correlated with mobility in pronated (rs=-0.699 and neutral (rs=-0.573 foot. No correlation was observed in balance performance with physiological factors in any of the foot postures. We can conclude that muscle function may be the most important feature to make movement possible in older persons regardless of the type of foot postures.

  17. DIABETIC FOOT ULCERS MICROBIOLOGICAL STUDY

    Directory of Open Access Journals (Sweden)

    P. Rajagopal

    2016-08-01

    Full Text Available BACKGROUND AND OBJECTIVES Infections of all types are more common in patients with diabetes, on the basis of outcome of retrospective study in Canada. Many types of infections are very common in diabetic than non-diabetic patients. Foot is the most common site. Diabetic foot infections range from mild infections to limb threatening conditions. Most require emergency medical attention. Diabetic foot infection is a global burden and projected to increase from 246 million people to over 380 million people by the year 2025. Many people with diabetes develop complications that seriously affect their quality and length of life. Lower limb complications are common, particularly foot ulcers and gangrene. Development of these complications is attributed to individual risk factors, poverty, racial and ethnic differences, and quality of local and national health care systems. The wide variations noted suggest that best practices in low incidence areas could easily be adapted in high incidence areas to reduce the burden of complications. Almost every infection begins in a wound, often as neuropathic ulceration or a traumatic break in the skin. Infections that begin as a small problem may progress to involve soft tissue, bones and joints. Because of these morbidity and occasional mortality by these foot infections several authoritative groups have recently developed guidelines for assessing and treating diabetic foot. METHODOLOGY 100 Diabetic patients with foot ulcers were admitted and wounds were classified using wagner’s classification. Pus was sent for culture and sensitivity and treated accordingly. RESULTS In our study the most common organism cultured from the wound with diabetes mellitus was staphylococcus. The most sensitive drug for these organisms was found to be chloramphenicol on most occasions. CONCLUSION The rationale of pus culture and sensitivity is not only to definitively treat the diabetic wound after the culture sensitivity report is

  18. Root structural and functional dynamics in terrestrial biosphere models--evaluation and recommendations.

    Science.gov (United States)

    Warren, Jeffrey M; Hanson, Paul J; Iversen, Colleen M; Kumar, Jitendra; Walker, Anthony P; Wullschleger, Stan D

    2015-01-01

    There is wide breadth of root function within ecosystems that should be considered when modeling the terrestrial biosphere. Root structure and function are closely associated with control of plant water and nutrient uptake from the soil, plant carbon (C) assimilation, partitioning and release to the soils, and control of biogeochemical cycles through interactions within the rhizosphere. Root function is extremely dynamic and dependent on internal plant signals, root traits and morphology, and the physical, chemical and biotic soil environment. While plant roots have significant structural and functional plasticity to changing environmental conditions, their dynamics are noticeably absent from the land component of process-based Earth system models used to simulate global biogeochemical cycling. Their dynamic representation in large-scale models should improve model veracity. Here, we describe current root inclusion in models across scales, ranging from mechanistic processes of single roots to parameterized root processes operating at the landscape scale. With this foundation we discuss how existing and future root functional knowledge, new data compilation efforts, and novel modeling platforms can be leveraged to enhance root functionality in large-scale terrestrial biosphere models by improving parameterization within models, and introducing new components such as dynamic root distribution and root functional traits linked to resource extraction.

  19. 24 CFR 3285.312 - Footings.

    Science.gov (United States)

    2010-04-01

    ... MODEL MANUFACTURED HOME INSTALLATION STANDARDS Foundations § 3285.312 Footings. (a) Materials approved... density. A footing must support every pier. Footings are to be either: (1) Concrete. (i) Four inch nominal... requirements when frame blocking only is used. 2. In addition to blocking required by § 3285.311, see Table...

  20. A nonlinear correlation function for selecting the delay time in dynamical reconstructions

    Science.gov (United States)

    Aguirre, Luis Antonio

    1995-02-01

    Numerical results discussed in this paper suggest that a function which detects nonlinear correlations in time series usually indicates shorter correlation times than the linear autocorrelation function which is often used for this purpose. The nonlinear correlation function can also detect changes in the data which cannot be distinguished by the linear counterpart. This affects a number of approaches for the selection of the delay time used in the reconstruction of nonlinear dynamics from a single time series based on time delay coordinates.

  1. Impact of foot pronation on postural stability: An observational study.

    Science.gov (United States)

    Koura, Ghada Mohamed; Elimy, Doaa Ayoub; Hamada, Hamada Ahmed; Fawaz, Hossam Eddien; Elgendy, Mohamed Hussein; Saab, Ibtissam M

    2017-09-15

    To investigate the effect of foot pronation on the dynamic balance including overall stability index (OAI), anteroposterior stability index (APSI) and mediolateral stability index (MLSI). Forty participants from both sexes were selected from the Faculty of Physical Therapy, Cairo University, with a mean age of 23.55 ± 1.74 years. Subjects were divided into two groups: group A (8 males and 12 females) with foot pronation, and group B (9 males and 11 females) with normal feet. The Navicular Drop Test (NDT) was used to determine if the feet were pronated and Biodex Balance System was used to assess dynamic balance at level 8 and level 4 for both groups. No significant difference was found in dynamic balance, including OAI, APSI and MLSI at stability level 8 (p> 0.05) but, there was a significant difference at stability level 4 (p< 0.05) between the two groups with lower stability in group A. Foot pronation or flat feet influences the dynamic balance at stability level four using the Biodex Balance System compared with those in the control group.

  2. The Impacts of Hinged and Solid Ankle-Foot Orthoses on Standing and Walking in Children with Spastic Diplegia

    Directory of Open Access Journals (Sweden)

    Hamid DALVAND

    2013-11-01

    orthoses on walking efficiency and gait in children with cerebral palsy. J Rehabil Med 2008;40(7:529-34.Abel MF, Juhl GA,Vaughan CL, Damiano DL. Gait assessment of fixed ankle-foot orthoses in children with spastic diplegia. Arch Phys Med Rehabil 1998;79(2:126-33.Balaban B, Yasar E, Dal U, Yazicioglu K, Mohur H, Kalyon TA. The effect of hinged ankle-foot orthosis on gait and energy expenditure in spastic hemiplegic cerebral palsy. Disabil Rehabil 2007;29(2:139-44.Wilson H, Haideri N, Song K, Telford D. Ankle-foot orthoses for preambulatory children with spastic diplegia. J Pediat Orthoped 1997;17(3:370-6.Romkes J, Hell AK, Brunner R. Changes in muscle activity in children with hemiplegic cerebral palsy while walking with and without ankle-foot orthoses. Gait Posture 2006;24(4:467-74.Radtka SA, Skinner SR, Dixon DM, Johanson ME. A comparison of gait with solid, dynamic, and no ankle-foot orthoses in children with spastic cerebral palsy. Phys Ther 1997;77(4:395-409.Radtka SA, Skinner SR, Johanson ME. A comparison of gait with solid and hinged ankle-foot orthoses in children with spastic diplegic cerebral palsy. Gait Posture 2005;21:303-10.Hayek S, Hemo Y, Chamis S, Bat R, Segev E, Wientroub S, et al. The effect of community prescribed ankle–foot orthoses on gait parameters in children with spastic cerebral palsy. J Children’s Orthoped 2007;1(6:325-32.Burtenr PA, Woollactt MM, Qualls C. Stance balance control with orthoses in a group of children with spastic cerebral palsy. Dev Med Child Neurol 1999;41(11:748-57.Bjornson KF, Schmale GA, Adamczyk-Foster A, McLaughlin J. The effect of dynamic ankle foot orthoses on function in children with cerebral palsy. J Pediat Orthoped 2006;26(6:773-6.Hassani S, Ferdjallah M, Reiners K, Johnson C, Smith P, Harris G. Motor performance comparison of the hinged and dynamic ankle-foot orthotics. Dev Med Child Neurol 2002;44(91:4.Smith PA, Hassani S, Graf A, Flanagan A, Reiners K. Brace evaluation in children with diplegic cerebral palsy

  3. A wearable system for multi-segment foot kinetics measurement.

    Science.gov (United States)

    Rouhani, H; Favre, J; Crevoisier, X; Aminian, K

    2014-05-01

    This study aims to design a wearable system for kinetics measurement of multi-segment foot joints in long-distance walking and to investigate its suitability for clinical evaluations. The wearable system consisted of inertial sensors (3D gyroscopes and 3D accelerometers) on toes, forefoot, hindfoot, and shank, and a plantar pressure insole. After calibration in a laboratory, 10 healthy elderly subjects and 12 patients with ankle osteoarthritis walked 50m twice wearing this system. Using inverse dynamics, 3D forces, moments, and power were calculated in the joint sections among toes, forefoot, hindfoot, and shank. Compared to those we previously estimated for a one-segment foot model, the sagittal and transverse moments and power in the ankle joint, as measured via multi-segment foot model, showed a normalized RMS difference of less than 11%, 14%, and 13%, respectively, for healthy subjects, and 13%, 15%, and 14%, for patients. Similar to our previous study, the coronal moments were not analyzed. Maxima-minima values of anterior-posterior and vertical force, sagittal moment, and power in shank-hindfoot and hindfoot-forefoot joints were significantly different between patients and healthy subjects. Except for power, the inter-subject repeatability of these parameters was CMC>0.90 for healthy subjects and CMC>0.70 for patients. Repeatability of these parameters was lower for the forefoot-toes joint. The proposed measurement system estimated multi-segment foot joints kinetics with acceptable repeatability but showed difference, compared to those previously estimated for the one-segment foot model. These parameters also could distinguish patients from healthy subjects. Thus, this system is suggested for outcome evaluations of foot treatments.

  4. Nonplantigrade Foot Posture: A Constraint on Dinosaur Body Size.

    Directory of Open Access Journals (Sweden)

    Tai Kubo

    Full Text Available Dinosaurs had functionally digitigrade or sub-unguligrade foot postures. With their immediate ancestors, dinosaurs were the only terrestrial nonplantigrades during the Mesozoic. Extant terrestrial mammals have different optimal body sizes according to their foot posture (plantigrade, digitigrade, and unguligrade, yet the relationship of nonplantigrade foot posture with dinosaur body size has never been investigated, even though the body size of dinosaurs has been studied intensively. According to a large dataset presented in this study, the body sizes of all nonplantigrades (including nonvolant dinosaurs, nonvolant terrestrial birds, extant mammals, and extinct Nearctic mammals are above 500 g, except for macroscelid mammals (i.e., elephant shrew, a few alvarezsauroid dinosaurs, and nondinosaur ornithodirans (i.e., the immediate ancestors of dinosaurs. When nonplantigrade tetrapods evolved from plantigrade ancestors, lineages with nonplantigrade foot posture exhibited a steady increase in body size following Cope's rule. In contrast, contemporaneous plantigrade lineages exhibited no trend in body size evolution and were largely constrained to small body sizes. This evolutionary pattern of body size specific to foot posture occurred repeatedly during both the Mesozoic and the Cenozoic eras. Although disturbed by the end-Cretaceous extinction, species of mid to large body size have predominantly been nonplantigrade animals from the Jurassic until the present; conversely, species with small body size have been exclusively composed of plantigrades in the nonvolant terrestrial tetrapod fauna.

  5. Nonplantigrade Foot Posture: A Constraint on Dinosaur Body Size.

    Science.gov (United States)

    Kubo, Tai; Kubo, Mugino O

    2016-01-01

    Dinosaurs had functionally digitigrade or sub-unguligrade foot postures. With their immediate ancestors, dinosaurs were the only terrestrial nonplantigrades during the Mesozoic. Extant terrestrial mammals have different optimal body sizes according to their foot posture (plantigrade, digitigrade, and unguligrade), yet the relationship of nonplantigrade foot posture with dinosaur body size has never been investigated, even though the body size of dinosaurs has been studied intensively. According to a large dataset presented in this study, the body sizes of all nonplantigrades (including nonvolant dinosaurs, nonvolant terrestrial birds, extant mammals, and extinct Nearctic mammals) are above 500 g, except for macroscelid mammals (i.e., elephant shrew), a few alvarezsauroid dinosaurs, and nondinosaur ornithodirans (i.e., the immediate ancestors of dinosaurs). When nonplantigrade tetrapods evolved from plantigrade ancestors, lineages with nonplantigrade foot posture exhibited a steady increase in body size following Cope's rule. In contrast, contemporaneous plantigrade lineages exhibited no trend in body size evolution and were largely constrained to small body sizes. This evolutionary pattern of body size specific to foot posture occurred repeatedly during both the Mesozoic and the Cenozoic eras. Although disturbed by the end-Cretaceous extinction, species of mid to large body size have predominantly been nonplantigrade animals from the Jurassic until the present; conversely, species with small body size have been exclusively composed of plantigrades in the nonvolant terrestrial tetrapod fauna.

  6. Ray amputation for the treatment of foot macrodactyly in children.

    Science.gov (United States)

    Kim, J; Park, J W; Hong, S W; Jeong, J Y; Gong, H S; Baek, G H

    2015-10-01

    Macrodactyly of the foot is a rare but disabling condition. We present the results of surgery on 18 feet of 16 patients, who underwent ray amputation and were followed-up for more than two years at a mean of 80 months (25 to 198). We radiologically measured the intermetatarsal width and forefoot area pre-operatively and at six weeks and two years after surgery. We also evaluated the clinical results using the Oxford Ankle Foot Questionnaire for children (OxAFQ-C) and the Questionnaire for Foot Macrodactyly. The intermetatarsal width and forefoot area ratios were significantly decreased after surgery. The mean OxAFQ-C score was 42 (16 to 57) pre-operatively, improving to 47 (5 to 60) at two years post-operatively (p = 0.021). The mean questionnaire for Foot Macrodactyly score two years after surgery was 8 (6 to 10). Ray amputation gave a measurable reduction in foot size with excellent functional results. For patients with metatarsal involvement, a motionless toe, or involvement of multiple digits, ray amputation is a clinically effective option which is acceptable to patients.

  7. Identification of Foot Pathologies Based on Plantar Pressure Asymmetry

    Directory of Open Access Journals (Sweden)

    Linah Wafai

    2015-08-01

    Full Text Available Foot pathologies can negatively influence foot function, consequently impairing gait during daily activity, and severely impacting an individual’s quality of life. These pathologies are often painful and correspond with high or abnormal plantar pressure, which can result in asymmetry in the pressure distribution between the two feet. There is currently no general consensus on the presence of asymmetry in able-bodied gait, and plantar pressure analysis during gait is in dire need of a standardized method to quantify asymmetry. This paper investigates the use of plantar pressure asymmetry for pathological gait diagnosis. The results of this study involving plantar pressure analysis in fifty one participants (31 healthy and 20 with foot pathologies support the presence of plantar pressure asymmetry in normal gait. A higher level of asymmetry was detected at the majority of the regions in the feet of the pathological population, including statistically significant differences in the plantar pressure asymmetry in two regions of the foot, metatarsophalangeal joint 3 (MPJ3 and the lateral heel. Quantification of plantar pressure asymmetry may prove to be useful for the identification and diagnosis of various foot pathologies.

  8. Structure, dynamics, and function of the monooxygenase P450 BM-3: insights from computer simulations studies

    Science.gov (United States)

    Roccatano, Danilo

    2015-07-01

    The monooxygenase P450 BM-3 is a NADPH-dependent fatty acid hydroxylase enzyme isolated from soil bacterium Bacillus megaterium. As a pivotal member of cytochrome P450 superfamily, it has been intensely studied for the comprehension of structure-dynamics-function relationships in this class of enzymes. In addition, due to its peculiar properties, it is also a promising enzyme for biochemical and biomedical applications. However, despite the efforts, the full understanding of the enzyme structure and dynamics is not yet achieved. Computational studies, particularly molecular dynamics (MD) simulations, have importantly contributed to this endeavor by providing new insights at an atomic level regarding the correlations between structure, dynamics, and function of the protein. This topical review summarizes computational studies based on MD simulations of the cytochrome P450 BM-3 and gives an outlook on future directions.

  9. Dynamic network participation of functional connectivity hubs assessed by resting-state fMRI

    Directory of Open Access Journals (Sweden)

    Alexander eSchaefer

    2014-05-01

    Full Text Available Network studies of large-scale brain connectivity have demonstrated that highly connected areas, or ‘hubs’, are a key feature of human functional and structural brain organization. We use resting-state functional MRI data and connectivity clustering to identify multi network hubs and show that while hubs can belong to multiple networks their degree of integration into these different networks varies dynamically over time. In addition, we found that these network dynamics were inversely related to positive self-generated thoughts reported by individuals and were further decreased with older age. Moreover, the left caudate varied its degree of participation between a default mode subnetwork and a limbic network. This variation was predictive of individual differences in the reports of past-related thoughts. These results support an association between ongoing thought processes and network dynamics and offer a new approach to investigate the brain dynamics underlying mental experience.

  10. [Functional magnetic resonance imaging and dynamic neuroanatomy of addictive disorders].

    Science.gov (United States)

    Mel'nikov, M E; Shtark, M B

    2014-01-01

    Research into the cerebral patterns that govern the formation and development of addictive behavior is one of the most interesting goals of neurophysiology. Authors of contemporary papers on the matter define a number of symptoms that are all part of substance or non-substance dependence, each one of them leading to abnormalities in the corresponding system of the brain. During the last twenty years the functional magnetic resonance imaging (fMR1) technology has been instrumental in locating such abnormalities, identifying specific parts of the brain that, when dysfunctional, may enhance addiction and cause its positive or negative symptoms. This article reviews fMRI studies aimed toward locating areas in the brain that are responsible for cognitive, emotional, and motivational dysfunction. Cerebral correlatives of impulsiveness, behavior control, and drug cravings are reviewed separately. The article also contains an overview of possibilities to further investigate the Selves of those dependent on substances, identify previously unknown diagnostic markers of substance dependence, and evaluate the effectiveness of therapy. The research under review in this article provides data that points to a special role of the nucleus caudatus as well as the nucleus accumbens, the thalamus, the insular cortex (IC), the anterior cingulate, prefrontal and orbitofrontal areas in psychological disorders that are part of substance dependence. General findings of the article are in accordance with contemporary models of addictive pattern.

  11. Effect of gait triggered functional electrical stimulation on foot drop patients after stroke%步态诱发功能性电刺激对脑卒中足下垂患者的疗效观察

    Institute of Scientific and Technical Information of China (English)

    刘翠华; 张盘德; 容小川; 周惠嫦; 陈丽珊; 林楚克; 李桂恩; 武士龙

    2011-01-01

    , XFT-2001P neuromuscular locator was used to find sensitive position, then the negative electrode was placed on sensitive position (common peroneal nerve) and the positive electrode was placed on the suitable position (tibialis anterior muscle). Walking function was evaluated before treatment, 1 week after treatment and 2 weeks after treatment.Result: After 2 weeks treatment, daring walking with low-frequency electrical pulse stimulator walking speed, transfer ability, up and down stairs ability improved immediately and the physiological cost consumption of foot drop patients after stroke reduced(P<0.05-0.001). Conclusion: Low-frequency electrical pulse stimulator could improve walking function of affected low limbs offoot drop patients after stroke. Walking speed, transfer ability, up and down stairs ability improved significantly and physiological consumption reduced significantly during walking with the stimulator. The stimulator had no ob-viaus side effect and it was considered to be a safe and effective training equipment.

  12. ONYCHOMADESIS IN A CHILD - SEQUELAE OF HAND - FOOT - MOUTH DISEASE

    Directory of Open Access Journals (Sweden)

    Adhikrishnan

    2015-04-01

    Full Text Available Hand – Foot – Mouth disease of coxsackie a virus and Enteroviruses. With symptoms like fever, sore throat, followed by Maculopapular and vesicular lesions around the oral cavity, palms and soles and recently adding to the list is onychomadesis. As a result of nail matrix function arrest, there is transverse ridging (beau’s lines, temporary loss of nail plate.

  13. Sea Surface Temperature Modeling using Radial Basis Function Networks With a Dynamically Weighted Particle Filter

    KAUST Repository

    Ryu, Duchwan

    2013-03-01

    The sea surface temperature (SST) is an important factor of the earth climate system. A deep understanding of SST is essential for climate monitoring and prediction. In general, SST follows a nonlinear pattern in both time and location and can be modeled by a dynamic system which changes with time and location. In this article, we propose a radial basis function network-based dynamic model which is able to catch the nonlinearity of the data and propose to use the dynamically weighted particle filter to estimate the parameters of the dynamic model. We analyze the SST observed in the Caribbean Islands area after a hurricane using the proposed dynamic model. Comparing to the traditional grid-based approach that requires a supercomputer due to its high computational demand, our approach requires much less CPU time and makes real-time forecasting of SST doable on a personal computer. Supplementary materials for this article are available online. © 2013 American Statistical Association.

  14. Dynamic functional connectivity analysis of Taichong (LR3) acupuncture effects in various brain regions

    Institute of Scientific and Technical Information of China (English)

    Wenjuan Qiu; Bin Yan; Hongjian He; Li Tong; Jianxin Li

    2012-01-01

    The present study conducted a multi-scale dynamic functional connectivity analysis to evaluate dynamic behavior of acupuncture at Taichong (LR3) and sham acupoints surrounding Taichong. Results showed differences in wavelet transform coherence characteristic curves in the declive, precuneus, postcentral gyrus, supramarginal gyrus, and occipital lobe between acupuncture at Taichong and acupuncture at sham acupoints. The differences in characteristic curves revealed that the specific effect of acupuncture existed during the post-acupuncture rest state and lasted for 5 minutes.

  15. Clinical examination and foot pressure analysis of diabetic foot: Prospective analytical study in Indian diabetic patients.

    Directory of Open Access Journals (Sweden)

    Harshanand Popalwar

    2016-03-01

    Conclusion: Meticulous clinical examination can easily identify diabetic neuropathy and related pathological complications of diabetic foot. This shall help for early diagnosis and prevention of diabetic foot complications. Foot pressure analysis can be useful tool to screen patients of diabetic foot for abnormal high pressure point areas and can predict future risk of ulceration due to high foot pressure. This study states findings in Indian diabetic patients. [Natl J Med Res 2016; 6(1.000: 17-22

  16. Reliability and normative values of the foot line test: a technique to assess foot posture

    DEFF Research Database (Denmark)

    Brushøj, C; Larsen, Klaus; Nielsen, MB;

    2007-01-01

    STUDY DESIGN: Test-retest reliability. OBJECTIVE: To examine the reliability and report normative values of a novel test, the foot line test (FLT), to describe foot morphology. BACKGROUND: Numerous foot examinations are performed each day, but most existing examination techniques have considerable......). There was no significant association between foot size and FLT values. CONCLUSION: The FLT is a reproducible technique to assess foot posture....

  17. STUDY ON DYNAMICS, STABILITY AND CONTROL OF MULTI-BODY FLEXIBLE STRUCTURE SYSTEM IN FUNCTIONAL SPACE

    Institute of Scientific and Technical Information of China (English)

    徐建国; 贾军国

    2001-01-01

    The dynamics, stability and control problem of a kind of infinite dimensional system are studied in the functional space with the method of modern mathematics. First,the dynamical control model of the distributed parameter system with multi-body flexible and multi-topological structure was established which has damping, gyroscopic parts and constrained damping. Secondly, the necessary and sufficient condition of controllability and observability, the stability theory and asymptotic property of the system were obtained.These results expand the theory of the field about the dynamics and control of the system with multi-body flexible structure, and have important engineering significance.

  18. Dynamic remodeling of microbial biofilms by functionally distinct exopolysaccharides.

    Science.gov (United States)

    Chew, Su Chuen; Kundukad, Binu; Seviour, Thomas; van der Maarel, Johan R C; Yang, Liang; Rice, Scott A; Doyle, Patrick; Kjelleberg, Staffan

    2014-08-05

    Biofilms are densely populated communities of microbial cells protected and held together by a matrix of extracellular polymeric substances. The structure and rheological properties of the matrix at the microscale influence the retention and transport of molecules and cells in the biofilm, thereby dictating population and community behavior. Despite its importance, quantitative descriptions of the matrix microstructure and microrheology are limited. Here, particle-tracking microrheology in combination with genetic approaches was used to spatially and temporally study the rheological contributions of the major exopolysaccharides Pel and Psl in Pseudomonas aeruginosa biofilms. Psl increased the elasticity and effective cross-linking within the matrix, which strengthened its scaffold and appeared to facilitate the formation of microcolonies. Conversely, Pel reduced effective cross-linking within the matrix. Without Psl, the matrix becomes more viscous, which facilitates biofilm spreading. The wild-type biofilm decreased in effective cross-linking over time, which would be advantageous for the spreading and colonization of new surfaces. This suggests that there are regulatory mechanisms to control production of the exopolysaccharides that serve to remodel the matrix of developing biofilms. The exopolysaccharides were also found to have profound effects on the spatial organization and integration of P. aeruginosa in a mixed-species biofilm model of P. aeruginosa-Staphylococcus aureus. Pel was required for close association of the two species in mixed-species microcolonies. In contrast, Psl was important for P. aeruginosa to form single-species biofilms on top of S. aureus biofilms. Our results demonstrate that Pel and Psl have distinct physical properties and functional roles during biofilm formation. Importance: Most bacteria grow as biofilms in the environment or in association with eukaryotic hosts. Removal of biofilms that form on surfaces is a challenge in clinical

  19. Sensory functions in the foot soles in victims of generalized torture, in victims also beaten under the feet (falanga) and in healthy controls - A blinded study using quantitative sensory testing

    DEFF Research Database (Denmark)

    Prip, K.; Persson, Anja; Sjolund, B. H.

    2012-01-01

    Background: Falanga torture (beatings on the foot soles) produces local chronic pain and severe walking difficulties. We have previously reported signs of neuropathic pain in the feet of falanga victims. The objective here was to clarify underlying pain mechanisms by quantifying sensory impairments...

  20. Dynamic density functional theory of protein adsorption on polymer-coated nanoparticles

    CERN Document Server

    Angioletti-Uberti, Stefano; Dzubiella, Joachim

    2014-01-01

    We present a theoretical model for the description of the adsorption kinetics of globular proteins onto charged core-shell microgel particles based on Dynamic Density Functional Theory (DDFT). This model builds on a previous description of protein adsorption thermodynamics [Yigit \\textit{et al}, Langmuir 28 (2012)], shown to well interpret the available calorimetric experimental data of binding isotherms. In practice, a spatially-dependent free-energy functional including the same physical interactions is built, and used to study the kinetics via a generalised diffusion equation. To test this model, we apply it to the case study of Lysozyme adsorption on PNIPAM coated nanoparticles, and show that the dynamics obtained within DDFT is consistent with that extrapolated from experiments. We also perform a systematic study of the effect of various parameters in our model, and investigate the loading dynamics as a function of proteins' valence and hydrophobic adsorption energy, as well as their concentration and th...

  1. BIONic WalkAide for correcting foot drop.

    Science.gov (United States)

    Weber, Douglas J; Stein, Richard B; Chan, K Ming; Loeb, Gerald; Richmond, Frances; Rolf, Robert; James, Kelly; Chong, Su Ling

    2005-06-01

    The goal of this study was to test the feasibility and efficacy of using microstimulators (BIONs) to correct foot drop, the first human application of BIONs in functional electrical stimulation (FES). A prototype BIONic foot drop stimulator was developed by modifying a WalkAide2 stimulator to control BION stimulation of the ankle dorsiflexor muscles. BION stimulation was compared with surface stimulation of the common peroneal nerve provided by a normal WalkAide2 foot drop stimulator. Compared to surface stimulation, we found that BION stimulation of the deep peroneal nerve produces a more balanced ankle flexion movement without everting the foot. A three-dimensional motion analysis was performed to measure the ankle and foot kinematics with and without stimulation. Without stimulation, the toe on the affected leg drags across the ground. The BIONic WalkAide elevates the foot such that the toe clears the ground by 3 cm, which is equivalent to the toe clearance in the unaffected leg. The physiological cost index (PCI) was used to measure effort during walking. The PCI is high without stimulation (2.29 +/- 0.37; mean +/- S.D.) and greatly reduced with surface (1.29 +/- 0.10) and BION stimulation (1.46 +/- 0.24). Also, walking speed is increased from 9.4 +/- 0.4 m/min without stimulation to 19.6 +/- 2.0 m/min with surface and 17.8 +/- 0.7 m/min with BION stimulation. We conclude that functional electrical stimulation with BIONs is a practical alternative to surface stimulation and provides more selective control of muscle activation.

  2. Statistical inference of dynamic resting-state functional connectivity using hierarchical observation modeling.

    Science.gov (United States)

    Sojoudi, Alireza; Goodyear, Bradley G

    2016-12-01

    Spontaneous fluctuations of blood-oxygenation level-dependent functional magnetic resonance imaging (BOLD fMRI) signals are highly synchronous between brain regions that serve similar functions. This provides a means to investigate functional networks; however, most analysis techniques assume functional connections are constant over time. This may be problematic in the case of neurological disease, where functional connections may be highly variable. Recently, several methods have been proposed to determine moment-to-moment changes in the strength of functional connections over an imaging session (so called dynamic connectivity). Here a novel analysis framework based on a hierarchical observation modeling approach was proposed, to permit statistical inference of the presence of dynamic connectivity. A two-level linear model composed of overlapping sliding windows of fMRI signals, incorporating the fact that overlapping windows are not independent was described. To test this approach, datasets were synthesized whereby functional connectivity was either constant (significant or insignificant) or modulated by an external input. The method successfully determines the statistical significance of a functional connection in phase with the modulation, and it exhibits greater sensitivity and specificity in detecting regions with variable connectivity, when compared with sliding-window correlation analysis. For real data, this technique possesses greater reproducibility and provides a more discriminative estimate of dynamic connectivity than sliding-window correlation analysis. Hum Brain Mapp 37:4566-4580, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  3. RISK FACTOR DIAGNOSTIC SCORE IN DIABETIC FOOT

    Directory of Open Access Journals (Sweden)

    Mohamed Shameem P. M

    2016-09-01

    Full Text Available INTRODUCTION Diabetic foot ulcers vary in their clinical presentation and nature of severity and therefore create a challenging problem to the treating surgeon regarding the prediction of the clinical course and the end result of the treatment. Clinical studies have shown that there are certain risk factors for the progression of foot ulcers in diabetics and it may therefore be possible to predict the course of an ulcer foot at presentation itself, thus instituting proper therapy without delay. Spoken otherwise clinical scoring may tell that this particular ulcer is having highest chance of amputation, then one may be able to take an early decision for the same and avoid the septic complications, inconvenience to the patient, long hospital stay and cost of treatments. AIM OF THE STUDY Aim of the study is to evaluate the above-mentioned scoring system in predicting the course the diabetic foot ulcers. MATERIALS AND METHODS 50 patients with Diabetic Foot attending the OPD of Department of Surgery of Government Hospital attached to Calicut Medical College are included in the present study. After thorough history taking and clinical examination, six risk factors like Age, pedal vessels, renal function, neuropathy, radiological findings and ulcers were observed in the patients by giving certain scoring points to each of them. The total number of points scored by the patients at the time of admission or OPD treatment was correlated with the final outcome in these patients, whether leading to amputation or conservative management. All the data was analysed using standard statistical methods. OBSERVATIONS AND RESULTS There were 12 females and 38 males with a female to male ratio 1:3.1. All were aged above 30 years. Twenty-four (48% of them were between 30-60 years and twenty six (52% were above 60 years. 10 patients were treated conservatively with risk score range: 10 to 35. Six had single toe loss with risk score: 25 to 35. Six had multiple toe loss

  4. Effective Boolean dynamics analysis to identify functionally important genes in large-scale signaling networks.

    Science.gov (United States)

    Trinh, Hung-Cuong; Kwon, Yung-Keun

    2015-11-01

    Efficiently identifying functionally important genes in order to understand the minimal requirements of normal cellular development is challenging. To this end, a variety of structural measures have been proposed and their effectiveness has been investigated in recent literature; however, few studies have shown the effectiveness of dynamics-based measures. This led us to investigate a dynamic measure to identify functionally important genes, and the effectiveness of which was verified through application on two large-scale human signaling networks. We specifically consider Boolean sensitivity-based dynamics against an update-rule perturbation (BSU) as a dynamic measure. Through investigations on two large-scale human signaling networks, we found that genes with relatively high BSU values show slower evolutionary rate and higher proportions of essential genes and drug targets than other genes. Gene-ontology analysis showed clear differences between the former and latter groups of genes. Furthermore, we compare the identification accuracies of essential genes and drug targets via BSU and five well-known structural measures. Although BSU did not always show the best performance, it effectively identified the putative set of genes, which is significantly different from the results obtained via the structural measures. Most interestingly, BSU showed the highest synergy effect in identifying the functionally important genes in conjunction with other measures. Our results imply that Boolean-sensitive dynamics can be used as a measure to effectively identify functionally important genes in signaling networks.

  5. Toe functions have little effect on dynamic balance ability in elderly people.

    Science.gov (United States)

    Yoshimoto, Yoshinobu; Oyama, Yukitsuna; Tanaka, Mamoru; Sakamoto, Asuka

    2017-01-01

    [Purpose] The purpose of this study was to examine the toe function of elderly people and the association with the dynamic balance ability for the developing effective fall-prevention measures. [Subjects and Methods] Seventy-eight participants in a community health service were included in this cross-sectional study. The Timed Up and Go Test and Four Square Step Test were used to test dynamic balance ability. The toe functions related to dynamic balance ability were toe flexion strength, presence or absence of restricted range of motion of the hallux, presence or absence of hallux pain, and hallux valgus angle. [Results] Factors related to the Timed Up and Go Test results were toe flexion strength, age, and presence or absence of hallux pain. Their standard partial regression coefficients were -0.400, 0.277, and -0.218, respectively. Factors related to the Four Square Step Test results were toe flexion strength and age. Their standard partial regression coefficients were -0.334 and 0.277, respectively. [Conclusion] Toe functions appear to have little impact on dynamic balance ability in elderly people who have mild toe dysfunction. Approaches that address not only the toes, but trunk functions, and other leg joints should be investigated for improving the dynamic balance ability.

  6. High transition frequencies of dynamic functional connectivity states in the creative brain

    Science.gov (United States)

    Li, Junchao; Zhang, Delong; Liang, Aiying; Liang, Bishan; Wang, Zengjian; Cai, Yuxuan; Gao, Mengxia; Gao, Zhenni; Chang, Song; Jiao, Bingqing; Huang, Ruiwang; Liu, Ming

    2017-01-01

    Creativity is thought to require the flexible reconfiguration of multiple brain regions that interact in transient and complex communication patterns. In contrast to prior emphases on searching for specific regions or networks associated with creative performance, we focused on exploring the association between the reconfiguration of dynamic functional connectivity states and creative ability. We hypothesized that a high frequency of dynamic functional connectivity state transitions will be associated with creative ability. To test this hypothesis, we recruited a high-creative group (HCG) and a low-creative group (LCG) of participants and collected resting-state fMRI (R-fMRI) data and Torrance Tests of Creative Thinking (TTCT) scores from each participant. By combining an independent component analysis with a dynamic network analysis approach, we discovered the HCG had more frequent transitions between dynamic functional connectivity (dFC) states than the LCG. Moreover, a confirmatory analysis using multiplication of temporal derivatives also indicated that there were more frequent dFC state transitions in the HCG. Taken together, these results provided empirical evidence for a linkage between the flexible reconfiguration of dynamic functional connectivity states and creative ability. These findings have the potential to provide new insights into the neural basis of creativity. PMID:28383052

  7. High transition frequencies of dynamic functional connectivity states in the creative brain.

    Science.gov (United States)

    Li, Junchao; Zhang, Delong; Liang, Aiying; Liang, Bishan; Wang, Zengjian; Cai, Yuxuan; Gao, Mengxia; Gao, Zhenni; Chang, Song; Jiao, Bingqing; Huang, Ruiwang; Liu, Ming

    2017-04-06

    Creativity is thought to require the flexible reconfiguration of multiple brain regions that interact in transient and complex communication patterns. In contrast to prior emphases on searching for specific regions or networks associated with creative performance, we focused on exploring the association between the reconfiguration of dynamic functional connectivity states and creative ability. We hypothesized that a high frequency of dynamic functional connectivity state transitions will be associated with creative ability. To test this hypothesis, we recruited a high-creative group (HCG) and a low-creative group (LCG) of participants and collected resting-state fMRI (R-fMRI) data and Torrance Tests of Creative Thinking (TTCT) scores from each participant. By combining an independent component analysis with a dynamic network analysis approach, we discovered the HCG had more frequent transitions between dynamic functional connectivity (dFC) states than the LCG. Moreover, a confirmatory analysis using multiplication of temporal derivatives also indicated that there were more frequent dFC state transitions in the HCG. Taken together, these results provided empirical evidence for a linkage between the flexible reconfiguration of dynamic functional connectivity states and creative ability. These findings have the potential to provide new insights into the neural basis of creativity.

  8. Dynamical density functional theory for molecular and colloidal fluids: a microscopic approach to fluid mechanics.

    Science.gov (United States)

    Archer, A J

    2009-01-07

    In recent years, a number of dynamical density functional theories (DDFTs) have been developed for describing the dynamics of the one-body density of both colloidal and atomic fluids. In the colloidal case, the particles are assumed to have stochastic equations of motion and theories exist for both the case when the particle motion is overdamped and also in the regime where inertial effects are relevant. In this paper, we extend the theory and explore the connections between the microscopic DDFT and the equations of motion from continuum fluid mechanics. In particular, starting from the Kramers equation, which governs the dynamics of the phase space probability distribution function for the system, we show that one may obtain an approximate DDFT that is a generalization of the Euler equation. This DDFT is capable of describing the dynamics of the fluid density profile down to the scale of the individual particles. As with previous DDFTs, the dynamical equations require as input the Helmholtz free energy functional from equilibrium density functional theory (DFT). For an equilibrium system, the theory predicts the same fluid one-body density profile as one would obtain from DFT. Making further approximations, we show that the theory may be used to obtain the mode coupling theory that is widely used for describing the transition from a liquid to a glassy state.

  9. Foot Placement Indicator for Balance of Planar Bipeds with Point Feet

    Directory of Open Access Journals (Sweden)

    Pieter van Zutven

    2013-05-01

    Full Text Available Abstract If humanoid robots are to be used in society, they should be able to maintain their balance. Knowing where to step is crucially important. In this paper we contribute an algorithm that can compute the foot step location such that bipedal balance is maintained for planar bipeds with point feet and an arbitrary number of non-massless links on a horizontal and flat ground. The algorithm is called the foot placement indicator (FPI and it extends the foot placement estimator (FPE. The FPE uses an inverted pendulum model to capture the dynamics of a humanoid robot, whereas the FPI deals with multi-body models with distributed masses. This paper analyses equilibrium sets and the stability of planar bipeds with point feet. The algorithm uses conservation of energy throughout the step, taking into account the instantaneous impact dynamics at foot strike. A simulation case study on a five-link planar biped shows the effectiveness of the FPI.

  10. Foot Placement Indicator for Balance of Planar Bipeds with Point Feet

    Directory of Open Access Journals (Sweden)

    Pieter van Zutven

    2013-05-01

    Full Text Available If humanoid robots are to be used in society, they should be able to maintain their balance. Knowing where to step is crucially important. In this paper we contribute an algorithm that can compute the foot step location such that bipedal balance is maintained for planar bipeds with point feet and an arbitrary number of non‐massless links on a horizontal and flat ground. The algorithm is called the foot placement indicator (FPI and it extends the foot placement estimator (FPE. The FPE uses an inverted pendulum model to capture the dynamics of a humanoid robot, whereas the FPI deals with multi‐body models with distributed masses. This paper analyses equilibrium sets and the stability of planar bipeds with point feet. The algorithm uses conservation of energy throughout the step, taking into account the instantaneous impact dynamics at foot strike. A simulation case study on a five‐link planar biped shows the effectiveness of the FPI.

  11. 临床手法结合功能锻炼矫治生长发育儿童扁平足的探讨%Discussion of Clinical Manipulative Therapy Combined with Functional Exercise to Treat the Children with Flat Foot

    Institute of Scientific and Technical Information of China (English)

    陈瑞巧

    2016-01-01

    随着我国优生优育政策与措施的不断完善,人们对生长发育儿童的身体保健越来越重视,有调查结果显示,我国约有1/3的人患有不同程度的扁平足。今年3月,某中心对江南第一幼儿院、海珠幼儿院和儿童福利幼儿院的630名儿童进行的调查发现扁平足患者竟有389人,约占62%。目前,治疗扁平足的手段主要有传统的体育锻炼、穿着合适的鞋子以及各种足部矫形器和鞋垫足部矫形器和鞋垫,还有一些手术疗法。我中心采用手法并配合功能锻炼的方法矫治扁平足患者取得了较好的效果。%With the continuous improvement of the policies and measures of eugenic and superior nurture of China,people pay more and more attention to the health care of children,according to the results of the recent survey,China has about a third of people with different degrees of flat foot.On march this year,630 children in Jiangnan First Kindergarten,Haizhu Kindergarten and Children's Welfare Kindergarten were re-searched,it was found that there were 389 children of flat foot,accounting for 62%.Flat foot is mainly trea-ted by traditional methods of physical exercise,wearing the right shoes and various foot brace and the insole foot brace and the insole,and some other surgical therapies.We used manipulative therapy combined with functional exercise to treat the patients with flat foot and got a good effect.

  12. Integrating palliative care with usual care of diabetic foot wounds.

    Science.gov (United States)

    Dunning, Trisha

    2016-01-01

    Palliative care is a philosophy and a system for deciding care and can be used alone or integrated with usual chronic disease care. Palliative care encompasses end-of-life care. Palliative care aims to enhance quality of life, optimize function and manage symptoms including early in the course of chronic diseases. The purposes of this article are to outline palliative care and discuss how it can be integrated with usual care of diabetic foot wounds. Many people with diabetes who have foot wounds also have other comorbidities and diabetes complications such as cardiovascular and renal disease and depression, which affect medicine and other treatment choices, functional status, surgical risk and quality of life. Two broad of diabetic foot disease exist: those likely to heal but who could still benefit from integrated palliative care such as managing pain and those where healing is unlikely where palliation can be the primary focus. People with diabetes can die suddenly, although the life course is usually long with periods of stable and unstable disease. Many health professionals are reluctant to discuss palliative care or suggest people to document their end-of-life care preferences. If such preferences are not documented, the person might not achieve their desired death or place of death and health professionals and families can be confronted with difficult decisions. Palliative care can be integrated with usual foot care and is associated with improved function, better quality of life and greater patient and family satisfaction.

  13. The effect of dynamic ankle-foot orthosis on ankle joints of children with cerebral palsy%动踝矫形鞋对脑瘫儿童踝关节的影响

    Institute of Scientific and Technical Information of China (English)

    杜文静; 李慧慧; 谈恩民; 王磊

    2015-01-01

    Aim:To analyze the effects of ankle foot orthosis on angle of ankle plantar flexion and dorsiflexion,and the walking cycle of lower limbs of children with cerebral palsy.Methods:25 subjects with cerebral palsy came to the physical therapy rehabilitation center volunteered to participate in the ex-periment in Shenzhen Disabled Rehabilitation Center,Guangdong,China in 2014 -06 /2014 -07,who were abnormal during walking.The child's parents or guardian informed consent.According to the chron-ological age,subjects were divided into four groups,5 of 2 ~4 years old group (2y ≤ age 0.05),and there was no significant difference between left and right side (P >0.05 ),the variance was equal.Between each age group,the parameters had no significant difference (P >0.05)expect for the cycle time between no wearing ankle-foot orthopedic and wearing ankle -foot orthopedic (P =0.02 <0.05).The cycle of time of left/right was 0.989 ±0.071 during no wearing ankle-foot orthopedic,and the coefficient of variation was 7.18% in all the samples.The cycle of time of left/right was 1.003 ±0.045 during wearing ankle-foot orthopedic,and the coefficient of variation was 4.49% in all the samples.It indicated that the gait of left and right was symmetry.Conclusion:The datas of 25 subjects were different between no wearing ankle-foot orthopedic and wearing ankle-foot ortho-pedic.① The more age were older,the smaller the angles of ankle plantar flexion were during no wearing ankle-foot orthopedic in all groups except 2 ~4 years old group.② The angle of ankle plantar flexion of children with wearing ankle-foot orthopedic were bigger than that of children without wearing ankle-foot orthopedic in different groups except the right side of 2 ~4 years old group and left side of 8 ~10 years old group,and the angle of ankle dorsiflexion of children with wearing ankle-foot orthopedic were bigger than that of children without wearing ankle-foot orthopedic in different groups.③ The more age were ol

  14. Dynamics of a family of transcendental meromorphic functions having rational Schwarzian derivative

    Science.gov (United States)

    Sajid, M.; Kapoor, G. P.

    2007-02-01

    In the present paper, a class of critically finite transcendental meromorphic functions having rational Schwarzian derivative is introduced and the dynamics of functions in one parameter family is investigated. It is found that there exist two parameter values [lambda]*=[phi](0)>0 and , where and is the real root of [phi]'(x)=0, such that the Fatou sets of f[lambda](z) for [lambda]=[lambda]* and [lambda]=[lambda]** contain parabolic domains. A computationally useful characterization of the Julia set of the function f[lambda](z) as the complement of the basin of attraction of an attracting real fixed point of f[lambda](z) is established and applied for the generation of the images of the Julia sets of f[lambda](z). Further, it is observed that the Julia set of explodes to whole complex plane for [lambda]>[lambda]**. Finally, our results found in the present paper are compared with the recent results on dynamics of one parameter families [lambda]tanz, [R.L. Devaney, L. Keen, Dynamics of meromorphic maps: Maps with polynomial Schwarzian derivative, Ann. Sci. Ecole Norm. Sup. 22 (4) (1989) 55-79; L. Keen, J. Kotus, Dynamics of the family [lambda]tan(z), Conform. Geom. Dynam. 1 (1997) 28-57; G.M. Stallard, The Hausdorff dimension of Julia sets of meromorphic functions, J. London Math. Soc. 49 (1994) 281-295] and , [lambda]>0 [G.P. Kapoor, M. Guru Prem Prasad, Dynamics of : The Julia set and bifurcation, Ergodic Theory Dynam. Systems 18 (1998) 1363-1383].

  15. Dynamic functional connectivity and brain metastability during altered states of consciousness.

    Science.gov (United States)

    Cavanna, Federico; Vilas, Martina G; Palmucci, Matías; Tagliazucchi, Enzo

    2017-10-03

    The scientific study of human consciousness has greatly benefited from the development of non-invasive brain imaging methods. The quest to identify the neural correlates of consciousness combined psychophysical experimentation with neuroimaging tools such as functional magnetic resonance imaging (fMRI) to map the changes in neural activity associated with conscious vs. unconscious percepts. Different neuroimaging methods have also been applied to characterize spontaneous brain activity fluctuations during altered states of consciousness, and to develop quantitative metrics for the level of consciousness. Most of these studies, however, have not explored the dynamic nature of the whole-brain imaging data provided by fMRI. A series of empirical and computational studies strongly suggests that the temporal fluctuations observed in this data present a non-trivial structure, and that this structure is compatible with the exploration of a discrete repertoire of states. In this review we focus on how dynamic neuroimaging can be used to address theoretical accounts of consciousness based on the hypothesis of a dynamic core, i.e. a constantly evolving and transiently stable set of coordinated neurons that constitute an integrated and differentiated physical substrate for each conscious experience. We review work exploring the possibility that metastability in brain dynamics leads to a repertoire of dynamic core states, and discuss how it might be modified during altered states of consciousness. This discussion prompts us to review neuroimaging studies aimed to map the dynamic exploration of the repertoire of states as a function of consciousness. Complementary studies of the dynamic core hypothesis using perturbative methods are also discussed. Finally, we propose that a link between metastability in brain dynamics and the level of consciousness could pave the way towards a mechanistic understanding of altered states of consciousness using tools from dynamical systems

  16. The Influence of Dynamic Orthosis Training on Upper Extremity Function after Stroke: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Rodrigo Cappato de Araújo

    2014-01-01

    Full Text Available The goal of this study was to assess the use of a dynamic orthosis on upper extremity function in chronic stroke patients. A case series approach was utilized, with provision of a training program (3x/week, 50 minutes/session for 8 weeks and employment of a dynamic orthosis. Six volunteers with persistent hemiparesis due to a single, unilateral stroke performed task-oriented movements with the aid of a dynamic orthosis. Tests were administered before and after training. Functional capacity was assessed using the TEMPA (Test d'Évaluation des Membres Supérieurs de Personnes Âgées test. The Wilcoxon test was used for pre-training and post-training comparisons of TEMPA scores. The volunteers showed significant improvement of upper extremity function in the performance of a bilateral task (p = 0.01 and three unilateral tasks (p = 0.04. This pilot study suggests that the dynamic orthosis associated with the performance of functional tasks can have positive outcomes regarding the improvement of functional capacity of upper extremity.

  17. TIME-HARMONIC DYNAMIC GREEN'S FUNCTIONS FOR ONE-DIMENSIONAL HEXAGONAL QUASICRYSTALS

    Institute of Scientific and Technical Information of China (English)

    Wang Xu

    2005-01-01

    Quasicrystals have additional phason degrees of freedom not found in conventional crystals. In this paper, we present an exact solution for time-harmonic dynamic Green's function of one-dimensional hexagonal quasicrystals with the Laue classes 6/mh and 6/mhmm. Through the introduction of two new functions ψ and ψ, the original problem is reduced to the determination of Green's functions for two independent Helmholtz equations. The explicit expressions of displacement and stress fields are presented and their asymptotic behaviors are discussed. The static Green's function can be obtained by letting the circular frequency approach zero.

  18. The abstracted and integrated Green functions and OOP of BEM in soil dynamics

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    It has been generally recognized that Green function integrated with Boundary Element Method (BEM) has advantages in dimensional reduction, high accuracy and satisfaction of the radiation condition at infinity, etc. Recently, the computational technique has rapidly developed and the orient-object programming has been widely applied, whereas the attribute ofion and the integration of Green function employed in BEM have not been discovered yet. In this work the abstrac- tion and integration of Green function are carried out for soil dynamics problems, and the procedure of the object-oriented calculation method is presented. Based on the Green function developed for the two-phase saturated medium, the re- sponse of the wave field to tunnel subjected to dynamic loading is calculated, and the transient solution as well as the time history of response is obtained.

  19. Quantum statistics and classical mechanics: real time correlation functions from ring polymer molecular dynamics.

    Science.gov (United States)

    Craig, Ian R; Manolopoulos, David E

    2004-08-22

    We propose an approximate method for calculating Kubo-transformed real-time correlation functions involving position-dependent operators, based on path integral (Parrinello-Rahman) molecular dynamics. The method gives the exact quantum mechanical correlation function at time zero, exactly satisfies the quantum mechanical detailed balance condition, and for correlation functions of the form C(Ax)(t) and C(xB)(t) it gives the exact result for a harmonic potential. It also works reasonably well at short times for more general potentials and correlation functions, as we illustrate with some example calculations. The method provides a consistent improvement over purely classical molecular dynamics that is most apparent in the low-temperature regime.

  20. Three applications of functional analysis with group dynamic cognitive behavioral group therapy.

    Science.gov (United States)

    Scharwächter, Peter

    2008-01-01

    Case illustrations from group dynamic cognitive behavioral group therapy are presented to demonstrate three applications of functional analysis and the resulting cognitive behavioral interventions. The principles of group dynamic cognitive behavioral group therapy are explained. A functional analysis is applied first to the problem behavior of an individual group member. A clinical case illustrates how the group members help to change this individual group member's behavior from a learning theory perspective. Next, the circular interactional problem behavior between two group members is reduced to the individual functional analysis of each of the two member's problem behaviors. It is then illustrated how the two group member's problem behaviors, as well as feedback from others, contribute toward helping to change each others behavior. The paper concludes that functional analysis and ensuing behavioral interventions can be also applied to group as a whole behavior.