Gait characteristics in women's safety shoes.

Science.gov (United States)

Goto, Kanako; Abe, Kaoru

2017-11-01

Although workers in Japan are required to wear safety footwear, there is concern about occupational accidents that occur when wearing safety shoes. This study aimed to analyze the effect of wearing hardsoled safety shoes on both spatiotemporal gait characteristics and the muscle activity in the lower extremities. Seventeen young women participated in this study. A 5-m gait trial and a surface electromyography trial were conducted while the women walked in either safety shoes or sports shoes. Paired t-tests were performed to analyze the differences in gait characteristics when walking in the two different pairs of shoes. Walking in safety shoes was associated with a significant increase in vastus lateralis, biceps femoris and tibialis anterior activity. This increased muscle activity in the lower extremities is likely compensating for the lower flexibility of the safety shoes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Differences in plantar loading between training shoes and racing flats at a self-selected running speed

NARCIS (Netherlands)

Wiegerinck, Johannes I.; Boyd, Jennifer; Yoder, Jordan C.; Abbey, Alicia N.; Nunley, James A.; Queen, Robin M.

2009-01-01

The purpose of this study was to examine the difference in plantar loading between two different running shoe types. We hypothesized that a higher maximum force, peak pressure, and contact area would exist beneath the entire foot while running in a racing flat when compared to a training shoe. 37

Effects of aluminum hinged shoes on the structure of contracted feet in Thoroughbred yearlings

OpenAIRE

TANAKA, Kousuke; HIRAGA, Atsushi; TAKAHASHI, Toshiyuki; KUWANO, Atsutoshi; MORRISON, Scott Edward

2015-01-01

ABSTRACT We applied aluminum hinged shoes (AHSs) to the club foot-associated contracted feet of 11 Thoroughbred yearlings to examine the effects of the shoes on the shape of the hoof and third phalanx (P III). After 3 months of AHS use, the size of the affected hooves increased significantly, reaching the approximate size of the healthy contralateral hooves with respect to the maximum lateral width of the foot, the mean ratio of the bearing border width to the coronary band width, and the mea...

Shoe allergic contact dermatitis.

Science.gov (United States)

Matthys, Erin; Zahir, Amir; Ehrlich, Alison

2014-01-01

Foot dermatitis is a widespread condition, affecting men and women of all ages. Because of the location, this condition may present as a debilitating problem to those who have it. Allergic contact dermatitis involving the feet is frequently due to shoes or socks. The allergens that cause shoe dermatitis can be found in any constituent of footwear, including rubber, adhesives, leather, dyes, metals, and medicaments. The goal of treatment is to identify and minimize contact with the offending allergen(s). The lack of product information released from shoe manufacturers and the continually changing trends in footwear present a challenge in treating this condition. The aim of this study is to review the current literature on allergic contact shoe dermatitis; clinical presentation, allergens, patch testing, and management will be discussed. PubMed and MEDLINE databases were used for the search, with a focus on literature updates from the last 15 years.

Effect of Shoes on Stiffness and Energy Efficiency of Ankle-Foot Orthosis: Bench Testing Analysis.

Science.gov (United States)

Kobayashi, Toshiki; Gao, Fan; LeCursi, Nicholas; Foreman, K Bo; Orendurff, Michael S

2017-12-01

Understanding the mechanical properties of ankle-foot orthoses (AFOs) is important to maximize their benefit for those with movement disorders during gait. Though mechanical properties such as stiffness and/or energy efficiency of AFOs have been extensively studied, it remains unknown how and to what extent shoes influence their properties. The aim of this study was to investigate the effect of shoes on stiffness and energy efficiency of an AFO using a custom mechanical testing device. Stiffness and energy efficiency of the AFO were measured in the plantar flexion and dorsiflexion range, respectively, under AFO-alone and AFO-Shoe combination conditions. The results of this study demonstrated that the stiffness of the AFO-Shoe combination was significantly decreased compared to the AFO-alone condition, but no significant differences were found in energy efficiency. From the results, we recommend that shoes used with AFOs should be carefully selected not only based on their effect on alignment of the lower limb, but also their effects on overall mechanical properties of the AFO-Shoe combination. Further study is needed to clarify the effects of differences in shoe designs on AFO-Shoe combination mechanical properties.

Injuries And Footwear (Part 2): Minimalist Running Shoes.

Science.gov (United States)

Knapik, Joseph J; Orr, Robin; Pope, Rodney; Grier, Tyson

2016-01-01

This article defines minimalist running shoes and examines physiological, biomechanical, and injury rate differences when running in conventional versus minimalist running shoes. A minimalist shoe is one that provides "minimal interference with the natural movement of the foot, because of its high flexibility, low heel to toe drop, weight and stack height, and the absence of motion control and stability devices." Most studies indicate that running in minimalist shoes results in a lower physiological energy cost than running in conventional shoes, likely because of the lower weight of the minimalist shoe. Most individuals running in conventional shoes impact the ground heel first (rearfoot strike pattern), whereas most people running in minimalist shoes tend to strike with the front of the foot (forefoot strike pattern). The rate at which force is developed on ground impact (i.e., the loading rate) is generally higher when running in conventional versus minimalist shoes. Findings from studies that have looked at associations between injuries and foot strike patterns or injuries and loading rates are conflicting, so it is not clear if these factors influence injury rates; more research is needed. Better-designed prospective studies indicate that bone stress injuries and the overall injury incidence are higher in minimalist shoes during the early weeks (10-12 weeks) of transition to this type of footwear. Longer-term studies are needed to define injury rates once runners are fully transitioned to minimalist shoes. At least one longer-term minimalist-shoe investigation is ongoing and, hopefully, will be published soon. 2016.

Stiffness Effects in Rocker-Soled Shoes: Biomechanical Implications

Science.gov (United States)

Su, Pei-Fang; Chung, Chia-Hua; Hsia, Chi-Chun; Chang, Chih-Han

2017-01-01

Rocker-soled shoes provide a way to reduce the possible concentration of stress, as well as change movement patterns, during gait. This study attempts to examine how plantar force and spatio-temporal variables are affected by two rocker designs, one with softer and one with denser sole materials, by comparing them with the barefoot condition and with flat-soled shoes. Eleven subjects’ gait parameters during walking and jogging were recorded. Our results showed that compared with barefoot walking, plantar forces were higher for flat shoes while lower for both types of rocker shoes, the softer-material rocker being the lowest. The plantar force of flat shoes is greater than the vertical ground reaction force, while that of both rocker shoes is much less, 13.87–30.55% body weight. However, as locomotion speed increased to jogging, for all shoe types, except at the second peak plantar force of the denser sole material rocker shoes, plantar forces were greater than for bare feet. More interestingly, because the transmission of force was faster while jogging, greater plantar force was seen in the rocker-soled shoes with softer material than with denser material; results for higher-speed shock absorption in rocker-soled shoes with softer material were thus not as good. In general, the rolling phenomena along the bottom surface of the rocker shoes, as well as an increase in the duration of simultaneous curve rolling and ankle rotation, could contribute to the reduction of plantar force for both rocker designs. The possible mechanism is the conversion of vertical kinetic energy into rotational kinetic energy. To conclude, since plantar force is related to foot-ground interface and deceleration methods, rocker-design shoes could achieve desired plantar force reduction through certain rolling phenomena, shoe-sole stiffness levels, and locomotion speeds. PMID:28046009

Stiffness Effects in Rocker-Soled Shoes: Biomechanical Implications.

Directory of Open Access Journals (Sweden)

Shih-Yun Lin

Full Text Available Rocker-soled shoes provide a way to reduce the possible concentration of stress, as well as change movement patterns, during gait. This study attempts to examine how plantar force and spatio-temporal variables are affected by two rocker designs, one with softer and one with denser sole materials, by comparing them with the barefoot condition and with flat-soled shoes. Eleven subjects' gait parameters during walking and jogging were recorded. Our results showed that compared with barefoot walking, plantar forces were higher for flat shoes while lower for both types of rocker shoes, the softer-material rocker being the lowest. The plantar force of flat shoes is greater than the vertical ground reaction force, while that of both rocker shoes is much less, 13.87-30.55% body weight. However, as locomotion speed increased to jogging, for all shoe types, except at the second peak plantar force of the denser sole material rocker shoes, plantar forces were greater than for bare feet. More interestingly, because the transmission of force was faster while jogging, greater plantar force was seen in the rocker-soled shoes with softer material than with denser material; results for higher-speed shock absorption in rocker-soled shoes with softer material were thus not as good. In general, the rolling phenomena along the bottom surface of the rocker shoes, as well as an increase in the duration of simultaneous curve rolling and ankle rotation, could contribute to the reduction of plantar force for both rocker designs. The possible mechanism is the conversion of vertical kinetic energy into rotational kinetic energy. To conclude, since plantar force is related to foot-ground interface and deceleration methods, rocker-design shoes could achieve desired plantar force reduction through certain rolling phenomena, shoe-sole stiffness levels, and locomotion speeds.

Radiation exposure from shoe-fitting fluoroscopes

International Nuclear Information System (INIS)

Busch, Uwe

2015-01-01

It is 40 years ago that a very popular X-ray device disappeared in German shoe shops: the shoe-fitting fluoroscope or Pedoskop. Since the 1930s, these X-ray machines were an integral part of any good shoe business. Following the entry into force X-Ray Regulation (RoeV 1973) the use of these devices was prohibited in Germany.

[The functional sport shoe parameter "torsion" within running shoe research--a literature review].

Science.gov (United States)

Michel, F I; Kälin, X; Metzger, A; Westphal, K; Schweizer, F; Campe, S; Segesser, B

2009-12-01

Within the sport shoe area torsion is described as the twisting and decoupling of the rear-, mid- and forefoot along the longitudinal axis of the foot. Studies have shown that running shoes restrict the torsion of the foot and thus they increase the pronation of the foot. Based on the findings, it is recommended to design running shoes, which allow the natural freedom of movement of the foot. The market introduction of the first torsion concept through adidas(R) took place in 1989. Independently of the first market introduction, only one epidemiological study was conducted in the running shoe area. The study should investigate the occurrence of Achilles tendon problems of the athletes running in the new "adidas Torsion(R) shoes". However, further studies quantifying the optimal region of torsionability concerning the reduction of injury incidence are still missing. Newer studies reveal that the criterion torsion only plays a secondary roll regarding the buying decision. Moreover, athletes are not able to perceive torsionability as a discrete functional parameter. It is to register, that several workgroups are dealing intensively with the detailed analysis of the foot movement based on kinematic multi-segment-models. However, scientific as well as popular scientific contributions display that the original idea of the torsion concept is still not completely understood. Hence, the "inverse" characteristic is postulated. The present literature review leads to the deduction that the functional characteristics of the torsion concept are not fully implemented within the running shoe area. This implies the necessity of scientific studies, which investigate the relevance of a functional torsion concept regarding injury prevention based on basic and applied research. Besides, biomechanical studies should analyse systematically the mechanism and the effects of torsion relevant technologies and systems.

Injury-reduction effectiveness of prescribing running shoes on the basis of foot arch height: summary of military investigations.

Science.gov (United States)

Knapik, Joseph J; Trone, Daniel W; Tchandja, Juste; Jones, Bruce H

2014-10-01

Secondary analysis of 3 randomized controlled trials. Objective Analysis of studies that examined whether prescribing running shoes on the basis of foot arch height influenced injury risk during military basic training. Prior to 2007, running magazines and running-shoe companies suggested that imprints of the bottom of the feet (plantar shape) could be used as an indication of foot arch height and that this could be used to select individually appropriate types of running shoes. Similar studies were conducted in US Army (2168 men, 951 women), Air Force (1955 men, 718 women), and Marine Corps (840 men, 571 women) basic training. After foot examinations, recruits were randomized to either an experimental or a control group. Recruits in the experimental group selected or were assigned motion-control, stability, or cushioned shoes to match their plantar shape, which represented a low, medium, or high foot arch, respectively. The control group received a stability shoe regardless of plantar shape. Injuries during basic training were assessed from outpatient medical records. Meta-analyses that pooled results of the 3 investigations showed little difference between the experimental and control groups in the injury rate (injuries per 1000 person-days) for either men (summary rate ratio = 0.97; 95% confidence interval [CI]: 0.88, 1.06) or women (summary rate ratio = 0.97; 95% CI: 0.85, 1.08). When injury rates for specific types of running shoes were compared, there were no differences. Selecting running shoes based on arch height had little influence on injury risk in military basic training. Prevention, level 1b.

To what extent does not wearing shoes affect the local dynamic stability of walking?: effect size and intrasession repeatability.

Science.gov (United States)

Terrier, Philippe; Reynard, Fabienne

2014-04-01

Local dynamic stability (stability) quantifies how a system responds to small perturbations. Several experimental and clinical findings have highlighted the association between gait stability and fall risk. Walking without shoes is known to slightly modify gait parameters. Barefoot walking may cause unusual sensory feedback to individuals accustomed to shod walking, and this may affect stability. The objective was therefore to compare the stability of shod and barefoot walking in healthy individuals and to analyze the intrasession repeatability. Forty participants traversed a 70 m indoor corridor wearing normal shoes in one trial and walking barefoot in a second trial. Trunk accelerations were recorded with a 3D-accelerometer attached to the lower back. The stability was computed using the finite-time maximal Lyapunov exponent method. Absolute agreement between the forward and backward paths was estimated with the intraclass correlation coefficient (ICC). Barefoot walking did not significantly modify the stability as compared with shod walking (average standardized effect size: +0.11). The intrasession repeatability was high (ICC: 0.73-0.81) and slightly higher in barefoot walking condition (ICC: 0.81-0.87). Therefore, it seems that barefoot walking can be used to evaluate stability without introducing a bias as compared with shod walking, and with a sufficient reliability.

Effects of aluminum hinged shoes on the structure of contracted feet in Thoroughbred yearlings.

Science.gov (United States)

Tanaka, Kousuke; Hiraga, Atsushi; Takahashi, Toshiyuki; Kuwano, Atsutoshi; Morrison, Scott Edward

2015-01-01

We applied aluminum hinged shoes (AHSs) to the club foot-associated contracted feet of 11 Thoroughbred yearlings to examine the effects of the shoes on the shape of the hoof and third phalanx (P III). After 3 months of AHS use, the size of the affected hooves increased significantly, reaching the approximate size of the healthy contralateral hooves with respect to the maximum lateral width of the foot, the mean ratio of the bearing border width to the coronary band width, and the mean ratio of the solar surface width to the articular surface width. These results suggest that the AHSs corrected the contracted feet in these yearling horses.

Metallurgical Design and Development of NASA Crawler/Transporter Tread Belt Shoe Castings

Science.gov (United States)

Parker, Donald S.

2006-01-01

The NASA Crawler/Transporters (CT-1 and CT-2) used to transport the Space Shuffles are one of the largest tracked vehicles in existence today. Two of these machines have been used to move space flight vehicles at Kennedy Space Center since the Apollo missions of the 1960's and relatively few modifications have been made to keep them operational. In September of 2003 during normal Crawler/Transporter operations cracks were observed along the roller pad surfaces of several tread belt shoes. Further examination showed 20 cracked shoes on CT-1 and 40 cracked shoes on CT-2 and a formal failure analysis investigation was undertaken while the cracked shoes were replaced. Six shoes were cross-sectioned with the fracture surfaces exposed and it was determined that the cracks were due to fatigue that initiated on the internal casting web channels at pre-existing casting defects and propagated through thickness both transgranularly and intergranularly between internal shrinkage cavities, porosity, and along austenitic and ferritic grain boundaries. The original shoes were cast during the 1960's using a modified 861330 steel with slightly higher levels of chromium, nickel and molybdenum followed by heat treatment to achieve a minimum tensile strength of 11 Oksi. Subsequent metallurgical analysis of the tread belt shoes after multiple failures showed excessive internal defects, alloy segregation, a nonuniform ferritic/ bainitic/martensitic microstructure, and low average tensile properties indicative of poor casting and poor heat-treatment. As a result, NASA funded an initiative to replace all of the tread belt shoes on both crawler/transporters along with a redesign of the alloy, manufacturing, and heat-treatment to create a homogeneous cast structure with uniform mechanical and metallurgical properties. ME Global, a wholly owned subsidiary of ME Elecmetal based in Minneapolis, MN was selected as manufacturing and design partner to develop the new shoes and this paper

Exploiting Fashion Features for Floor Storage Systems in the Shoe Industry

Directory of Open Access Journals (Sweden)

Antonella Meneghetti

2013-08-01

Full Text Available Floor storage systems are used in the shoe industry to store fashion products of seasonal collections of low quantity and high variety. Since space is valuable and order picking must be sped up, stacking of shoeboxes should be optimized. The problem is modelled based on shoe features (model, type, colour, and size and with the goal of forcing similar boxes into locations close to each other in order to improve workers’ ability to retrieve orders fast. The model is encoded in Constraint Logic Programming and solved comparing different strategies, also using Large Neighbourhood Search. Simulation experiments are run to evaluate how the stacking model affects picking performance.

Comparison of shoe-length fit between people with and without diabetic peripheral neuropathy: a case–control study

Directory of Open Access Journals (Sweden)

McInnes Alistair D

2012-04-01

Full Text Available Abstract Background Amongst the many identified mechanisms leading to diabetic foot ulceration, ill-fitting footwear is one. There is anecdotal evidence that people with diabetic peripheral neuropathy wear shoes that are too small in order to increase the sensation of fit. The aim of this study was to determine whether people with diabetic sensory neuropathy wear appropriate length footwear. Methods A case–control design was used to compare internal shoe length and foot length differences between a group of people with diabetes and peripheral sensory neuropathy and a group of people without diabetes and no peripheral sensory neuropathy. Shoe and foot length measurements were taken using a calibrated Internal Shoe Size Gauge® and a Brannock Device®, respectively. Results Data was collected from 85 participants with diabetes and 118 participants without diabetes. The mean difference between shoe and foot length was not significantly different between the two groups. However, a significant number of participants within both groups had a shoe to foot length difference that lay outside a previously suggested 10 to 15 mm range. From the diabetic and non-diabetic groups 82% (70/85 and 66% (78/118, respectively had a foot to shoe length difference outside this same range. Conclusions This study shows that although there is no significant difference in shoe-length fit between participants with and without neuropathy, a significant proportion of these populations wear shoes that are either too long or too short for their foot length according to the 10 to 15 mm value used for comparison. The study has highlighted the need for standardised approaches when considering the allowance required between foot and internal shoe length and for the measurement and comparison of foot and shoe dimensions.

Indoor and outdoor concentrations of RSP, NO2 and selected volatile organic compounds at 32 shoe stalls located near busy roadways in Seoul, Korea

International Nuclear Information System (INIS)

Bae, Hyunjoo; Chung, Moonho; Yang, Wonho

2004-01-01

It is suspected that persons who work in indoor environments near busy roadways are exposed to elevated levels of air pollutants during working hours. This study evaluated the potential exposure and source contribution associated with traffic-related air pollution for workers (polishers and repairmen) in shoe stalls from each of 32 districts during working hours in Seoul, Korea. The shoe stalls have been located at very close distances to the busy roadways. In this study, shoe stall workers could be exposed to high levels of respirable suspended particulate (RSP), nitrogen dioxide (NO 2 ) and volatile organic compounds (VOCs) from outdoor sources such as traffic exhaust, as well as indoor sources in the shoe stalls such as dust on the shoes, portable gas ranges, organic solvents, adhesives and shoe polish. Compounds of particular note included indoor mean concentrations of benzene, toluene, m/p-xylene and o-xylene were 0.732, 6.777, 4.080 and 1.302 mg/m 3 , respectively, in all shoe stalls. Mean indoor/outdoor ratios for toluene and m/p-xylene concentrations were 54.52 and 20.84, respectively. The contribution of vehicle exhaust emissions to indoor air quality of shoe stalls was identified by means of correlating the relationships between simultaneously measured air pollutant concentrations indoors and outdoors. Unlike RSP and NO 2 , indoor VOCs concentrations of shoe stalls mainly originated from indoor sources vs. outdoor sources

Modified distal shoe appliance for premature loss of multiple deciduous molars: a case report.

Science.gov (United States)

Bhat, Prasanna Kumar; K, Navin H; Idris, Mohammed; Christopher, Pradeep; Rai, Niharika

2014-08-01

Preservation of the primary dentition until the normal time of exfoliation is one of the most important factor involved in preventive and interceptive dentistry. The premature loss of second primary molar before the eruption of permanent first molar can create a significant arch space/tooth size discrepancy. Distal shoe space maintainer is a valuable part of the Paediatric Dentist's armamentarium in those cases where the second primary molar is prematurely lost and it helps to guide the first permanent molar into place. Conventional design poses various limitations in cases of premature loss of multiple deciduous molars. Thus, it is required to modify the conventional designs according to the needs of the patient. This case report describes an innovative modification of distal shoe appliance in cases of premature loss of multiple deciduous molars. In the present case, modification of distal shoe space maintainer was advocated because of inadequate abutments caused due to multiple loss of deciduous molars. Bilateral design of distal shoe was planned for unilateral loss of deciduous molars.

Contact allergens in shoe leather among patients with foot eczema.

NARCIS (Netherlands)

Coevorden, A.M. van; Coenraads, P.J.; Pas, H.H.; Valk, P.G.M. van der

2002-01-01

Some patients with relapsing foot eczema and a shoe leather allergy, who fail to show positive results with standard series and shoe wear screening tray patch testing, do not respond to the use of hypoallergenic shoe leather. We assume that relevant allergens are present in hypoallergenic shoe

Contact allergens in shoe leather among patients with foot eczema

NARCIS (Netherlands)

van Coevorden, AM; Coenraads, PJ; Pas, HH; van der Valk, PGM

Some patients with relapsing foot eczema and a shoe leather allergy, who fail to show positive results with standard series and shoe wear screening tray patch testing, do not respond to the use of hypoallergenic shoe leather. We assume that relevant allergens are present in hypoallergenic shoe

Differences in friction and torsional resistance in athletic shoe-turf surface interfaces.

Science.gov (United States)

Heidt, R S; Dormer, S G; Cawley, P W; Scranton, P E; Losse, G; Howard, M

1996-01-01

This study evaluated the shoe-surface interaction of 15 football shoes made by 3 manufacturers in both anterior translation and rotation using a specially designed pneumatic testing system. The shoes included traditional cleated football shoes, "court" shoes (basketball-style shoes), molded-cleat shoes, and turf shoes. Under an 11.35-kg (25-pound) axial load, all shoes were tested on synthetic turf under wet and dry conditions and on natural stadium grass. Test-retest reliability, as calculated using the Pearson Product-Moment Correlation test, was 0.85 for force of translation and 0.55 for the moment of rotation. The wet versus dry surface values on translation were significantly different for rotation about the tibial axis. Spatting, which is protective taping of the ankle and heel applied on the outside of the shoe, resulted in a reduction of forces generated in both translation and rotation. No overall difference between shoes on grass versus AstroTurf was noted. However, there were significant differences for cleated and turf shoes. Shoes tested in conditions for which they were not designed exhibited reproducible excessive or extreme minimal friction characteristics that may have safety implications. On the basis of this study, we urge shoe manufacturers to display suggested indications and playing surface conditions for which their shoes are recommended.

Acute effect of different minimalist shoes on foot strike pattern and kinematics in rearfoot strikers during running.

Science.gov (United States)

Squadrone, Roberto; Rodano, Renato; Hamill, Joseph; Preatoni, Ezio

2015-01-01

Despite the growing interest in minimalist shoes, no studies have compared the efficacy of different types of minimalist shoe models in reproducing barefoot running patterns and in eliciting biomechanical changes that make them differ from standard cushioned running shoes. The aim of this study was to investigate the acute effects of different footwear models, marketed as "minimalist" by their manufacturer, on running biomechanics. Six running shoes marketed as barefoot/minimalist models, a standard cushioned shoe and the barefoot condition were tested. Foot-/shoe-ground pressure and three-dimensional lower limb kinematics were measured in experienced rearfoot strike runners while they were running at 3.33 m · s⁻¹ on an instrumented treadmill. Physical and mechanical characteristics of shoes (mass, heel and forefoot sole thickness, shock absorption and flexibility) were measured with laboratory tests. There were significant changes in foot strike pattern (described by the strike index and foot contact angle) and spatio-temporal stride characteristics, whereas only some among the other selected kinematic parameters (i.e. knee angles and hip vertical displacement) changed accordingly. Different types of minimalist footwear models induced different changes. It appears that minimalist footwear with lower heel heights and minimal shock absorption is more effective in replicating barefoot running.

Kinematic and kinetic comparison of running in standard and minimalist shoes.

Science.gov (United States)

Willy, Richard W; Davis, Irene S

2014-02-01

The purpose of this study was to determine whether running in a minimalist shoe results in a reduction in ground reaction forces and alters kinematics over standard shoe running. The secondary purpose of this study was to determine whether within-session accommodation to a novel minimalist shoe occurs. Subjects were 14 male, rearfoot striking runners who had never run in a minimalist shoe. Subjects were tested while running 3.35 m·s(-1) for 10 min on an instrumented treadmill in a minimalist and a standard shoe as three-dimensional lower extremity kinematics and kinetics were evaluated. Data were collected at minute 1 and then again after 10 min of running in both shoe conditions to evaluate accommodation to the shoe conditions. Shoe-time interactions were not found for any of the variables of interest. Minimalist shoe running resulted in no changes in step length (P = 0.967) or in step rate (P = 0.230). At footstrike, greater knee flexion (P = 0.001) and greater dorsiflexion angle (P = 0.025) were noted in the minimalist shoe. Vertical impact peak (P = 0.017) and average vertical loading rate (P < 0.000) were greater during minimalist shoe running. There were main effects of time as dorsiflexion angle decreased (P = 0.035), foot inclination at footstrike decreased (P = 0.048), and knee flexion at footstrike increased (P = 0.002), yet the vertical impact peak (P = 0.002) and average vertical loading rate (P < 0.000) increased. Running in a minimalist shoe appears to, at least in the short term, increase loading of the lower extremity over standard shoe running. The accommodation period resulted in less favorable landing mechanics in both shoes. These findings bring into question whether minimal shoes will provide enough feedback to induce an alteration that is similar to barefoot running.

Mechanics of jazz shoes and their effect on pointing in child dancers.

Science.gov (United States)

Fong Yan, Alycia; Smith, Richard; Vanwanseele, Benedicte; Hiller, Claire

2012-07-01

There has been little scientific investigation of the impact of dance shoes on foot motion or dance injuries. The pointed (plantar-flexed) foot is a fundamental component of both the technical requirements and the traditional aesthetic of ballet and jazz dancing. The aims of this study were to quantify the externally observed angle of plantar flexion in various jazz shoes compared with barefoot and to compare the sagittal plane bending stiffness of the various jazz shoes. Sixteen female recreational child dancers were recruited for 3D motion analysis of active plantar flexion. The jazz shoes tested were a split-sole jazz shoe, full-sole jazz shoe, and jazz sneaker. A shoe dynamometer measured the stiffness of the jazz shoes. The shoes had a significant effect on ankle plantar flexion. All jazz shoes significantly restricted the midfoot plantar flexion angle compared with the barefoot condition. The split-sole jazz shoe demonstrated the least restriction, whereas the full-sole jazz shoe the most midfoot restriction. A small restriction in metartarsophalangeal plantar flexion and a greater restriction at the midfoot joint were demonstrated when wearing stiff jazz shoes. These restrictions will decrease the aesthetic of the pointed foot, may encourage incorrect muscle activation, and have an impact on dance performance.

Development of inexpensive prosthetic feet for high-heeled shoes using simple shoe insole model

OpenAIRE

Margrit R. Meier, PhD; Kerice A. Tucker, BSc; Andrew H. Hansen, PhD

2014-01-01

The large majority of prosthetic feet are aimed at low-heeled shoes, with a few models allowing a heel height of up to 5 cm. However, a survey by the American Podiatric Medical Association indicates that most women wear heels over 5 cm; thus, current prosthetic feet limit most female prosthesis users in their choice. Some prosthetic foot components are heel-height adjustable; however, their plantar surface shapes do not change to match the insole shapes of the shoes with different heel height...

The influence of shoe aging on children running biomechanics.

Science.gov (United States)

Herbaut, Alexis; Chavet, Pascale; Roux, Maxime; Guéguen, Nils; Barbier, Franck; Simoneau-Buessinger, Emilie

2017-07-01

Athletic children are prone to overuse injuries, especially at the heel and knee. Since footwear is an extrinsic factor of lower limb injury risk, the aim of this study was to assess the influence of shoe aging on children running biomechanics. Fourteen children active in sports participated in a laboratory biomechanical evaluation. A new pair of shoes was provided to each participant at an inclusion visit. Four months later, the participants performed a running task and their kinematics and kinetics were assessed both with their used shoes and with a new pair of shoes identical to the first. Furthermore, mechanical cushioning properties of shoes were evaluated before and after in-vivo aging. After 4months of use, the sole stiffness increased by 16% and the energy loss capacity decreased by 18% (pknee kinematic adjustment was found at foot strike in used shoes but changes were observed later during stance. Running with used shoes produced a higher loading rate of the vertical ground reaction force (+23%, p=0.016), suggesting higher compressive forces under the heel and placing children at risk to experience impact-related injuries. Nevertheless, the decreased peak ankle and knee power absorption in used shoes (-11%, p=0.010 and -12%, p=0.029, respectively) suggests a lower ankle and knee joints loading during the absorption phase that may be beneficial regarding stretch-related injuries. Copyright © 2017 Elsevier B.V. All rights reserved.

Shoe rim and shoe buckle pseudotumor of the ankle in elite and professional figure skaters and snowboarders: MR imaging findings

International Nuclear Information System (INIS)

Anderson, S.E.; Weber, M.; Steinbach, L.S.; Ballmer, F.T.

2004-01-01

To review MR imaging of figure skaters and snowboarders presenting with painful soft-tissue swelling of the lateral supramalleolar region with a clinical provisional diagnosis of soft-tissue tumor. MR imaging was prospectively reviewed by two sub-specialized musculoskeletal radiologists. The findings were correlated with a second clinical review and examination of the shoe wear. The patients were four female athletes undergoing heavy training regimes, ranging in age between 16 and 25 years. Two patients were elite figure skaters, and two were professional snowboarders. Three patients had unilateral masses with pain, and one patient presented with bilateral clinical findings. MR imaging showed subcutaneous, focal soft-tissue masses of the supramalleolar region in five ankles at the same level above the ankle joint. MR imaging prompted a second clinical review and correlation with the shoe wear. The MR imaging findings correlated to the level of the shoe rim or shoe buckle in all patients, confirming the suspected MR imaging diagnosis of an impingement syndrome. All four sportswomen were training excessively, ignoring safety advice regarding training duration, timing of breaks, and shoe wear rotation. (orig.)

Immediate effects of EVA midsole resilience and upper shoe structure on running biomechanics: a machine learning approach

OpenAIRE

Onodera, Andrea N.; Gavi?o Neto, Wilson P.; Roveri, Maria Isabel; Oliveira, Wagner R.; Sacco, Isabel CN

2017-01-01

Background Resilience of midsole material and the upper structure of the shoe are conceptual characteristics that can interfere in running biomechanics patterns. Artificial intelligence techniques can capture features from the entire waveform, adding new perspective for biomechanical analysis. This study tested the influence of shoe midsole resilience and upper structure on running kinematics and kinetics of non-professional runners by using feature selection, information gain, and artificial...

Patient compliance and effect of orthopaedic shoes

DEFF Research Database (Denmark)

Philipsen, A B; Ellitsgaard, N; Krogsgaard, M R

1999-01-01

Orthopaedic shoes are individually handmade after a prescription from an orthopaedic surgeon, hence relatively expensive. Bad compliance is mentioned in the literature but not investigated. In order to evaluate patient compliance and the effect of orthopaedic shoes, 85 patients who were prescribed...

Shoe-Insole Technology for Injury Prevention in Walking

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Hanatsu Nagano

2018-05-01

Full Text Available Impaired walking increases injury risk during locomotion, including falls-related acute injuries and overuse damage to lower limb joints. Gait impairments seriously restrict voluntary, habitual engagement in injury prevention activities, such as recreational walking and exercise. There is, therefore, an urgent need for technology-based interventions for gait disorders that are cost effective, willingly taken-up, and provide immediate positive effects on walking. Gait control using shoe-insoles has potential as an effective population-based intervention, and new sensor technologies will enhance the effectiveness of these devices. Shoe-insole modifications include: (i ankle joint support for falls prevention; (ii shock absorption by utilising lower-resilience materials at the heel; (iii improving reaction speed by stimulating cutaneous receptors; and (iv preserving dynamic balance via foot centre of pressure control. Using sensor technology, such as in-shoe pressure measurement and motion capture systems, gait can be precisely monitored, allowing us to visualise how shoe-insoles change walking patterns. In addition, in-shoe systems, such as pressure monitoring and inertial sensors, can be incorporated into the insole to monitor gait in real-time. Inertial sensors coupled with in-shoe foot pressure sensors and global positioning systems (GPS could be used to monitor spatiotemporal parameters in real-time. Real-time, online data management will enable ‘big-data’ applications to everyday gait control characteristics.

Rotational and peak torque stiffness of rugby shoes.

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Ballal, Moez S; Usuelli, Federico Giuseppe; Montrasio, Umberto Alfieri; Molloy, Andy; La Barbera, Luigi; Villa, Tomaso; Banfi, Giuseppe

2014-09-01

Sports people always strive to avoid injury. Sports shoe designs in many sports have been shown to affect traction and injury rates. The aim of this study is to demonstrate the differing stiffness and torque in rugby boots that are designed for the same effect. Five different types of rugby shoes commonly worn by scrum forwards were laboratory tested for rotational stiffness and peak torque on a natural playing surface generating force patterns that would be consistent with a rugby scrum. The overall internal rotation peak torque was 57.75±6.26 Nm while that of external rotation was 56.55±4.36 Nm. The Peak internal and external rotational stiffness were 0.696±0.1 and 0.708±0.06 Nm/deg respectively. Our results, when compared to rotational stiffness and peak torques of football shoes published in the literature, show that shoes worn by rugby players exert higher rotational and peak torque stiffness compared to football shoes when tested on the same natural surfaces. There was significant difference between the tested rugby shoes brands. In our opinion, to maximize potential performance and lower the potential of non-contact injury, care should be taken in choosing boots with stiffness appropriate to the players main playing role. Copyright © 2014 Elsevier Ltd. All rights reserved.

iShoes for blind and visually impaired people

OpenAIRE

Assairi, Bandar; Holmes, Violeta

2013-01-01

This paper presents the development of an iShoes system for blind and visually impaired people. The iShoes system utilizes a microcontroller with sound output interfaced with ultrasonic sensors. The prototype system is designed to be specifically mounted on/in the shoes to aid navigation in urban routes. The ultrasonic transducers determine the range from an obstacle and then play an audio message to reflect the distance from the target. This system will assist blind and visually impaired peo...

Predictive multiscale computational model of shoe-floor coefficient of friction.

Science.gov (United States)

Moghaddam, Seyed Reza M; Acharya, Arjun; Redfern, Mark S; Beschorner, Kurt E

2018-01-03

Understanding the frictional interactions between the shoe and floor during walking is critical to prevention of slips and falls, particularly when contaminants are present. A multiscale finite element model of shoe-floor-contaminant friction was developed that takes into account the surface and material characteristics of the shoe and flooring in microscopic and macroscopic scales. The model calculates shoe-floor coefficient of friction (COF) in boundary lubrication regime where effects of adhesion friction and hydrodynamic pressures are negligible. The validity of model outputs was assessed by comparing model predictions to the experimental results from mechanical COF testing. The multiscale model estimates were linearly related to the experimental results (p < 0.0001). The model predicted 73% of variability in experimentally-measured shoe-floor-contaminant COF. The results demonstrate the potential of multiscale finite element modeling in aiding slip-resistant shoe and flooring design and reducing slip and fall injuries. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Effect of rocker shoes on plantar pressure pattern in healthy female runners

NARCIS (Netherlands)

Sobhani, Sobhan; van den Heuvel, Edwin; Bredeweg, Steven; Kluitenberg, Bas; Postema, Klaas; Hijmans, Juha M.; Dekker, Rienk

Rocker profile shoes (rocker shoes) are one of the treatment options of metatarsalgia and forefoot stress fractures. The efficacy of rocker shoes in unloading the forefoot pressure has been shown in walking. In running, however, the effect of rocker shoes on forefoot pressure is unknown. Eighteen

Effect of environmental temperature on shock absorption properties of running shoes.

Science.gov (United States)

Dib, Mansour Y; Smith, Jay; Bernhardt, Kathie A; Kaufman, Kenton R; Miles, Kevin A

2005-05-01

To determine the effect of temperature changes on the shock attenuation of 4 running shoe shock absorption systems. Prospective. Motion analysis laboratory. The shock attenuation of 4 different running shoes representing common shock absorption systems (Nike Air Triax, Asics Gel Nimbus IV, Adidas a3 cushioning, Adidas Supernova cushion) was measured at ambient temperatures of -20 degrees C, -10 degrees C, 0 degrees C, +10 degrees C, +20 degrees C, +30 degrees C, +40 degrees C, and +50 degrees C. Repeated-measures analysis of variance was used to determine differences between shoes. Shock attenuation as indicated by peak deceleration (g) measured by a mechanical impactor following ASTM Standard F1614-99. Shock attenuation decreased significantly with reduced temperature for each shoe tested. The Adidas a3 shoe exhibited significantly higher peak decelerations (lower shock attenuation) at cold temperatures compared with the other shoes. Cold ambient temperatures significantly reduce the shock attenuation of commonly used running shoes. These findings have important clinical implications for individuals training in extreme weather environments, particularly those with a history of lower limb overuse injuries.

The Risks and Benefits of Running Barefoot or in Minimalist Shoes

OpenAIRE

Perkins, Kyle P.; Hanney, William J.; Rothschild, Carey E.

2014-01-01

Context: The popularity of running barefoot or in minimalist shoes has recently increased because of claims of injury prevention, enhanced running efficiency, and improved performance compared with running in shoes. Potential risks and benefits of running barefoot or in minimalist shoes have yet to be clearly defined. Objective: To determine the methodological quality and level of evidence pertaining to the risks and benefits of running barefoot or in minimalist shoes. Data Sources: In Septem...

Rotational stiffness of American football shoes affects ankle biomechanics and injury severity.

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Button, Keith D; Braman, Jerrod E; Davison, Mark A; Wei, Feng; Schaeffer, Maureen C; Haut, Roger C

2015-06-01

While previous studies have investigated the effect of shoe-surface interaction on injury risk, few studies have examined the effect of rotational stiffness of the shoe. The hypothesis of the current study was that ankles externally rotated to failure in shoes with low rotational stiffness would allow more talus eversion than those in shoes with a higher rotational stiffness, resulting in less severe injury. Twelve (six pairs) cadaver lower extremities were externally rotated to gross failure while positioned in 20 deg of pre-eversion and 20 deg of predorsiflexion by fixing the distal end of the foot, axially loading the proximal tibia, and internally rotating the tibia. One ankle in each pair was constrained by an American football shoe with a stiff upper, while the other was constrained by an American football shoe with a flexible upper. Experimental bone motions were input into specimen-specific computational models to examine levels of ligament elongation to help understand mechanisms of ankle joint failure. Ankles in flexible shoes allowed 6.7±2.4 deg of talus eversion during rotation, significantly greater than the 1.7±1.0 deg for ankles in stiff shoes (p = 0.01). The significantly greater eversion in flexible shoes was potentially due to a more natural response of the ankle during rotation, possibly affecting the injuries that were produced. All ankles failed by either medial ankle injury or syndesmotic injury, or a combination of both. Complex (more than one ligament or bone) injuries were noted in 4 of 6 ankles in stiff shoes and 1 of 6 ankles in flexible shoes. Ligament elongations from the computational model validated the experimental injury data. The current study suggested flexibility (or rotational stiffness) of the shoe may play an important role in both the severity of ankle injuries for athletes.

Running shoes and running injuries: mythbusting and a proposal for two new paradigms: 'preferred movement path' and 'comfort filter'.

Science.gov (United States)

Nigg, B M; Baltich, J; Hoerzer, S; Enders, H

2015-10-01

In the past 100 years, running shoes experienced dramatic changes. The question then arises whether or not running shoes (or sport shoes in general) influence the frequency of running injuries at all. This paper addresses five aspects related to running injuries and shoe selection, including (1) the changes in running injuries over the past 40 years, (2) the relationship between sport shoes, sport inserts and running injuries, (3) previously researched mechanisms of injury related to footwear and two new paradigms for injury prevention including (4) the 'preferred movement path' and (5) the 'comfort filter'. Specifically, the data regarding the relationship between impact characteristics and ankle pronation to the risk of developing a running-related injury is reviewed. Based on the lack of conclusive evidence for these two variables, which were once thought to be the prime predictors of running injuries, two new paradigms are suggested to elucidate the association between footwear and injury. These two paradigms, 'the preferred movement path' and 'the comfort filter', suggest that a runner intuitively selects a comfortable product using their own comfort filter that allows them to remain in the preferred movement path. This may automatically reduce the injury risk and may explain why there does not seem to be a secular trend in running injury rates. 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.

Immediate effects of EVA midsole resilience and upper shoe structure on running biomechanics: a machine learning approach

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Andrea N. Onodera

2017-02-01

Full Text Available Background Resilience of midsole material and the upper structure of the shoe are conceptual characteristics that can interfere in running biomechanics patterns. Artificial intelligence techniques can capture features from the entire waveform, adding new perspective for biomechanical analysis. This study tested the influence of shoe midsole resilience and upper structure on running kinematics and kinetics of non-professional runners by using feature selection, information gain, and artificial neural network analysis. Methods Twenty-seven experienced male runners (63 ± 44 km/week run ran in four-shoe design that combined two resilience-cushioning materials (low and high and two uppers (minimalist and structured. Kinematic data was acquired by six infrared cameras at 300 Hz, and ground reaction forces were acquired by two force plates at 1,200 Hz. We conducted a Machine Learning analysis to identify features from the complete kinematic and kinetic time series and from 42 discrete variables that had better discriminate the four shoes studied. For that analysis, we built an input data matrix of dimensions 1,080 (10 trials × 4 shoes × 27 subjects × 1,254 (3 joints × 3 planes of movement × 101 data points + 3 vectors forces × 101 data points + 42 discrete calculated kinetic and kinematic features. Results The applied feature selection by information gain and artificial neural networks successfully differentiated the two resilience materials using 200(16% biomechanical variables with an accuracy of 84.8% by detecting alterations of running biomechanics, and the two upper structures with an accuracy of 93.9%. Discussion The discrimination of midsole resilience resulted in lower accuracy levels than did the discrimination of the shoe uppers. In both cases, the ground reaction forces were among the 25 most relevant features. The resilience of the cushioning material caused significant effects on initial heel impact, while the effects

Immediate effects of EVA midsole resilience and upper shoe structure on running biomechanics: a machine learning approach.

Science.gov (United States)

Onodera, Andrea N; Gavião Neto, Wilson P; Roveri, Maria Isabel; Oliveira, Wagner R; Sacco, Isabel Cn

2017-01-01

Resilience of midsole material and the upper structure of the shoe are conceptual characteristics that can interfere in running biomechanics patterns. Artificial intelligence techniques can capture features from the entire waveform, adding new perspective for biomechanical analysis. This study tested the influence of shoe midsole resilience and upper structure on running kinematics and kinetics of non-professional runners by using feature selection, information gain, and artificial neural network analysis. Twenty-seven experienced male runners (63 ± 44 km/week run) ran in four-shoe design that combined two resilience-cushioning materials (low and high) and two uppers (minimalist and structured). Kinematic data was acquired by six infrared cameras at 300 Hz, and ground reaction forces were acquired by two force plates at 1,200 Hz. We conducted a Machine Learning analysis to identify features from the complete kinematic and kinetic time series and from 42 discrete variables that had better discriminate the four shoes studied. For that analysis, we built an input data matrix of dimensions 1,080 (10 trials × 4 shoes × 27 subjects) × 1,254 (3 joints × 3 planes of movement × 101 data points + 3 vectors forces × 101 data points + 42 discrete calculated kinetic and kinematic features). The applied feature selection by information gain and artificial neural networks successfully differentiated the two resilience materials using 200(16%) biomechanical variables with an accuracy of 84.8% by detecting alterations of running biomechanics, and the two upper structures with an accuracy of 93.9%. The discrimination of midsole resilience resulted in lower accuracy levels than did the discrimination of the shoe uppers. In both cases, the ground reaction forces were among the 25 most relevant features. The resilience of the cushioning material caused significant effects on initial heel impact, while the effects of different uppers were distributed along the

The re-emergence of the minimal running shoe.

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Davis, Irene S

2014-10-01

The running shoe has gone through significant changes since its inception. The purpose of this paper is to review these changes, the majority of which have occurred over the past 50 years. Running footwear began as very minimal, then evolved to become highly cushioned and supportive. However, over the past 5 years, there has been a reversal of this trend, with runners seeking more minimal shoes that allow their feet more natural motion. This abrupt shift toward footwear without cushioning and support has led to reports of injuries associated with minimal footwear. In response to this, the running footwear industry shifted again toward the development of lightweight, partial minimal shoes that offer some support and cushioning. In this paper, studies comparing the mechanics between running in minimal, partial minimal, and traditional shoes are reviewed. The implications for injuries in all 3 conditions are examined. The use of minimal footwear in other populations besides runners is discussed. Finally, areas for future research into minimal footwear are suggested.

Impact attenuation properties of jazz shoes alter lower limb joint stiffness during jump landings.

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Fong Yan, Alycia; Smith, Richard M; Hiller, Claire E; Sinclair, Peter J

2017-05-01

To quantify the impact attenuation properties of the jazz shoes, and to investigate the in-vivo effect of four jazz shoe designs on lower limb joint stiffness during a dance-specific jump. Repeated measures. A custom-built mechanical shoe tester similar to that used by athletic shoe companies was used to vertically impact the forefoot and heel region of four different jazz shoe designs. Additionally, dancers performed eight sautés in second position in bare feet and the shoe conditions. Force platforms and 3D-motion capture were used to analyse the joint stiffness of the midfoot, ankle, knee and hip during the jump landings. Mechanical testing of the jazz shoes revealed significant differences in impact attenuation characteristics among each of the jazz shoe designs. Gross knee and midfoot joint stiffness were significantly affected by the jazz shoe designs in the dancers' jump landings. The tested jazz shoe designs altered the impact attenuating capacity of jump landing technique in dancers. The cushioned jazz shoes are recommended particularly for injured dancers to reduce impact on the lower limb. Jazz shoe design should consider the impact attenuation properties of the forefoot region, due to the toe-strike landing technique in dance movement. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Effect of Five-Finger Shoes on Vertical Ground Reaction Force Loading Rates and Perceived Comfort during the Stance Phase of the Running

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Seyede Zeynab Hoseini

2016-06-01

Full Text Available Objective:  Increased vertical ground reaction force loading rates and lack of comfort footwear in the early stance phase can increase the risk of overuse injuries. The purpose of this study was to investigate the effect of Five-finger shoes on vertical ground reaction force loading rate and perceived comfort during the stance phase of running. Methods: 15 male students (aged 24 ± 5/24 years, weight 75/8 ± 4/61 kg, height 178/6 ± 6/64 cm were selected. Subjects were asked to run over a force plate, in control shoe, five finger shoe and barefoot conditions. Loading rate using the slope of the vertical reaction force and perceived comfort were determined using a visual analogue scale. One factor repeated measures ANOVA was used to test the loading rate hypothesis and Paired t-tests was used to test the meaningfulness of perceived comfort (P<0/05. Results: The effect of shoes on loading rate was found to be not significant (P=0.1. However, comfort of control shoes increased by 10. 92% as compared to that of five-finger shoes (P=0.001.  Conclusion: The loading rate of five-finger shoes is the same as that of barefoot during running; however, as subjects did not perceive them as comfortable as regular shoes are five-finger shoes cannot be advised as a desirable choice in exercises.

Cross-Domain Shoe Retrieval with a Semantic Hierarchy of Attribute Classification Network.

Science.gov (United States)

Zhan, Huijing; Shi, Boxin; Kot, Alex C

2017-08-04

Cross-domain shoe image retrieval is a challenging problem, because the query photo from the street domain (daily life scenario) and the reference photo in the online domain (online shop images) have significant visual differences due to the viewpoint and scale variation, self-occlusion, and cluttered background. This paper proposes the Semantic Hierarchy Of attributE Convolutional Neural Network (SHOE-CNN) with a three-level feature representation for discriminative shoe feature expression and efficient retrieval. The SHOE-CNN with its newly designed loss function systematically merges semantic attributes of closer visual appearances to prevent shoe images with the obvious visual differences being confused with each other; the features extracted from image, region, and part levels effectively match the shoe images across different domains. We collect a large-scale shoe dataset composed of 14341 street domain and 12652 corresponding online domain images with fine-grained attributes to train our network and evaluate our system. The top-20 retrieval accuracy improves significantly over the solution with the pre-trained CNN features.

Industrial research on the quality of brake shoes meant for rolling stock

Science.gov (United States)

Popa, E.; Pascu, L.; Socalici, A.; Lascufoni, A.

2016-02-01

Brake shoes wear appears as a normal exploitation process and depends both on the braking force and on the material the shoe is made of. Brake shoes are made of molded sulfurous cast iron. The industrial research and experiments aim at determining the specific characteristics of the phosphorous cast iron (chemical and structural homogeneity, hardness) and their optimization in view of improving the quality of the brake shoes meant for the rolling stock

Factors associated with use of slip-resistant shoes in US limited-service restaurant workers.

Science.gov (United States)

Verma, Santosh K; Courtney, Theodore K; Corns, Helen L; Huang, Yueng-Hsiang; Lombardi, David A; Chang, Wen-Ruey; Brennan, Melanye J; Perry, Melissa J

2012-06-01

Slips and falls are a leading cause of injury at work. Several studies have indicated that slip-resistant shoes can reduce the risk of occupational slips and falls. Few studies, however, have examined the determinants of slip-resistant shoe use. This study examined the individual and workplace factors associated with slip-resistant shoe use. 475 workers from 36 limited-service restaurants in the USA participated in a study of workplace slipping. Demographic and job characteristic information about each participant was collected. Restaurant managers provided information on whether slip-resistant shoes were provided and paid for by the employer and whether any guidance was given regarding slip-resistant shoe use when they were not provided. Kitchen floor coefficient of friction was measured. Slip-resistant status of the shoes was determined by noting the presence of a 'slip-resistant' marking on the sole. Poisson regression with robust SE was used to calculate prevalence ratios. 320 participants wore slip-resistant shoes (67%). In the multivariate analysis, the prevalence of slip-resistant shoe use was lowest in 15-19-year age group. Women were more likely to wear slip-resistant shoes (prevalence ratio 1.18, 95% CI 1.07 to 1.31). The prevalence of slip-resistant shoe use was lower when no guidance regarding slip-resistant shoes was given as compared to when they were provided by the employer (prevalence ratio 0.66, 95% CI 0.55 to 0.79). Education level, job tenure and the mean coefficient of friction had no significant effects on the use of slip-resistant shoes. Provision of slip-resistant shoes was the strongest predictor of their use. Given their effectiveness and low cost, employers should consider providing slip-resistant shoes at work.

Compressors selection and sizing

CERN Document Server

Brown, Royce N

2005-01-01

This practical reference provides in-depth information required to understand and properly estimate compressor capabilities and to select the proper designs. Engineers and students will gain a thorough understanding of compression principles, equipment, applications, selection, sizing, installation, and maintenance. The many examples clearly illustrate key aspects to help readers understand the ""real world"" of compressor technology.Compressors: Selection and Sizing, third edition is completely updated with new API standards. Additions requested by readers include a new section on di

Implementation of a Shoe-Embedded Human Interface and Collaborative Supplementation of Service Requirements on Smartphone System

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Kaname Takaochi

2013-01-01

Full Text Available Although a handsfree man-machine interface is useful when the user’s hands are not free, existing handsfree input devices are not the type of device that are normally worn by people. We have focused on a shoe as an input device because people normally wear it when they go out, and proposed a shoe-embedded interface. The input device is a sensor shoe. Weight sensors have been attached at three positions on a sole: the first metatarsal, the fifth metatarsal, and the calcaneal tuberosity. These positions have been selected based on the characteristics of the human foot skeleton. Two types of foot operation have been used: tap and push. By combining these operations, 10 commands have been defined. To make it possible to use web applications with a limited number of commands, we have proposed a method of supplementing the user’s service requirements using collaborative filtering. The sensor shoe houses an insole with hetero-core optical fiber sensor elements attached to it. These elements are sensitive to weight. We have built an experimental system that runs on a smartphone and provides the shoe-embedded interface, and conducted experiments with three test subjects to evaluate the system. The average rate of successful command identification was 89 %. We have also evaluated this service requirements supplementation method theoretically, and confirmed that the proposed service recommendation function can be applied to smartphone systems.

Effect of rocker-soled shoes on parameters of knee joint load in knee osteoarthritis.

Science.gov (United States)

Madden, Elizabeth G; Kean, Crystal O; Wrigley, Tim V; Bennell, Kim L; Hinman, Rana S

2015-01-01

This study evaluated the immediate effects of rocker-soled shoes on parameters of the knee adduction moment (KAM) and pain in individuals with knee osteoarthritis (OA). Three-dimensional gait analysis was performed on 30 individuals (mean (SD): age, 61 (7) yr; 15 (50%) male) with radiographic and symptomatic knee OA under three walking conditions in a randomized order: i) wearing rocker-soled shoes (Skechers Shape-ups), ii) wearing non-rocker-soled shoes (ASICS walking shoes), and iii) barefoot. Peak KAM and KAM angular impulse were measured as primary indicators of knee load distribution. Secondary measures included the knee flexion moment (KFM) and knee pain during walking. Peak KAM was significantly lower when wearing the rocker-soled shoes compared with that when wearing the non-rocker-soled shoes (mean difference (95% confidence interval), -0.27 (-0.42 to -0.12) N·m/BW × Ht%; P < 0.001). Post hoc tests revealed no significant difference in KAM impulse between rocker-soled and non-rocker-soled shoe conditions (P = 0.13). Both peak KAM and KAM impulse were significantly higher during both shoe conditions compared with those during the barefoot condition (P < 0.001). There were no significant differences in KFM (P = 0.36) or knee pain (P = 0.89) between conditions. Rocker-soled shoes significantly reduced peak KAM when compared with non-rocker-soled shoes, without a concomitant change in KFM, and thus may potentially reduce medial knee joint loading. However, KAM parameters in the rocker-soled shoes remained significantly higher than those during barefoot walking. Wearing rocker-soled shoes did not have a significant immediate effect on walking pain. Further research is required to evaluate whether rocker-soled shoes can influence symptoms and progression of knee OA with prolonged wear.

A case of contact dermatitis to dimethylfumarate in shoes identified in Italy

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Franca Davanzo

2010-12-01

Full Text Available The present paper describes a case of shoe contact dermatitis from DMF identified by the Poison Control Centre of Milan (PCCM, Italy, in 2009. A 35 year old woman was affected by irritant reactions while wearing shoes contaminated with DMF. Exposure to these shoes was limited to a 8 hour period and was not repeated. In the following days the patient suffered feet blistering and swelling limited to the area in contact with shoe vamp. Topical application of cortisone did not prevent development of bullous eczema. After 20 days from exposure, the lesions were healed but the skin remained red, dry and very sensitive. Chemical analyses of shoes quantified an average concentration of DMF of 383 mg/kg. The patient refused to be patch tested. The observation here reported confirm that DMF should be considered a possible causal agent in shoe contact dermatitis. Documentation of cases exposed to this chemical provide a relevant support to characterize clinical manifestations and to identifying contaminated articles.

Automated visual inspection of brake shoe wear

Science.gov (United States)

Lu, Shengfang; Liu, Zhen; Nan, Guo; Zhang, Guangjun

2015-10-01

With the rapid development of high-speed railway, the automated fault inspection is necessary to ensure train's operation safety. Visual technology is paid more attention in trouble detection and maintenance. For a linear CCD camera, Image alignment is the first step in fault detection. To increase the speed of image processing, an improved scale invariant feature transform (SIFT) method is presented. The image is divided into multiple levels of different resolution. Then, we do not stop to extract the feature from the lowest resolution to the highest level until we get sufficient SIFT key points. At that level, the image is registered and aligned quickly. In the stage of inspection, we devote our efforts to finding the trouble of brake shoe, which is one of the key components in brake system on electrical multiple units train (EMU). Its pre-warning on wear limitation is very important in fault detection. In this paper, we propose an automatic inspection approach to detect the fault of brake shoe. Firstly, we use multi-resolution pyramid template matching technology to fast locate the brake shoe. Then, we employ Hough transform to detect the circles of bolts in brake region. Due to the rigid characteristic of structure, we can identify whether the brake shoe has a fault. The experiments demonstrate that the way we propose has a good performance, and can meet the need of practical applications.

The effect of the heel- to- toe rocker shoe on moments of ankle joint and temporal-spatial of gait in female student

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masoomeh Veiskarami

2015-01-01

Full Text Available Background : Rocker shoes are the most commonly prescribed external therapeutic shoe modification and are used for treatment of the ankle and midfoot problems. The aim of this study was to assesse the effects of the heel- to-toe rocker shoes on temporal-spatial and ankle joint moments in sagital and frontal plane. Materials and Methods: In this quasi-exprimental study, three-dimentional gait analysis was carried out on 20 healthy university female students with normal normal gait pattern selected by convenience sampling method. A Vicon 470 system(Oxford Metrix, U.K. consisting of 6 cameras operating at 60Hz and kistler forceplate (A9286 was used.The paired samples T test was used to statistical analysis. Results: The results showed that there is no significant change in temporal-spatial parameters while wearing this modified shoe ,but the ankle moments while wearing rocker shoes in sagittal plane was significantly less than that while wearing traditional shoes(p=0.002 but in frontal plane significantly increased(p=0.007. Conclusion: Based on the current findings the major benefits of this modified shoe appear to be significantly restricted sagital plane moments with maintenance of walking speed so the loads on ankle joint and achilles tendon reduced, but increases frontal plain moments which leads to increase of mediolateral instability of ankle joint.

A consensus definition and rating scale for minimalist shoes.

Science.gov (United States)

Esculier, Jean-Francois; Dubois, Blaise; Dionne, Clermont E; Leblond, Jean; Roy, Jean-Sébastien

2015-01-01

While minimalist running shoes may have an influence on running biomechanics and on the incidence of overuse injuries, the term "minimalist" is currently used without standardisation. The objectives of this study were to reach a consensus on a standard definition of minimalist running shoes, and to develop and validate a rating scale that could be used to determine the degree of minimalism of running shoes, the Minimalist Index (MI). For this modified Delphi study, 42 experts from 11 countries completed four electronic questionnaires on an optimal definition of minimalist shoes and on elements to include within the MI. Once MI was developed following consensus, 85 participants subjectively ranked randomly assigned footwear models from the most to the least minimalist and rated their degree of minimalism using visual analog scales (VAS), before evaluating the same footwear models using MI. A subsample of thirty participants reassessed the same shoes on another occasion. Construct validity and inter- and intra-rater reliability (intraclass correlation coefficients [ICC]; Gwet's AC1) of MI were evaluated. The following definition of minimalist shoes was agreed upon by 95 % of participants: "Footwear providing minimal interference with the natural movement of the foot due to its high flexibility, low heel to toe drop, weight and stack height, and the absence of motion control and stability devices". Characteristics to be included in MI were weight, flexibility, heel to toe drop, stack height and motion control/stability devices, each subscale carrying equal weighing (20 %) on final score. Total MI score was highly correlated with VAS (r = 0.91). A significant rank effect (p minimalism, and may help to decrease injuries related to footwear transition.

Technical evaluation of a CAD system for orthopaedic shoe-upper design.

Science.gov (United States)

Lord, M; Foulston, J; Smith, P J

1991-01-01

Computer aided design is now employed routinely in the volume shoe trade. New styles are developed on a three-dimensional image of the last followed by automated pattern generation and engineering. It is suggested that such systems could be useful in the orthopaedic footwear industry although the different requirements for these bespoke products need careful consideration. A clinical trial has been conducted on the Shoemaster (Clarks Shoes) upper design system both to assess its technical capabilities and to consider its role in improvement of service and cosmetic appearance. This particular system works throughout on a three-dimensional representation of the shoe last, which offers particular advantages for integration with shape capture and reproduction. The report concentrates on the technical evaluation to assess (a) its ability to work with unusual last shapes dictated by medical requirements and (b) its potential for integration into a complete computer system for design of both shoe lasts and shoe uppers. The trial indicates that this particular system is promising in both respects.

Investigation of Friction Behaviors of Brake Shoe Materials using Metallic Filler

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E. Surojo

2015-12-01

Full Text Available Some vehicles use brake shoe made from semi-metallic materials. Semi-metallic brake shoes are made from a combination of metallic and non-metallic materials. Metallic particles are added in the formulation of brake shoe material to improve composites characteristics. In this paper, friction behaviors of brake shoe material using metallic filler were investigated. Machining chips of cast iron and copper wire of electric motor used were incorporated in composite as metallic fillers with amount 0, 2, and 4 vol. %. Friction testing was performed to measure coefficient of friction by pressing surface specimen against the surface of rotating disc. The results show that cast iron chip and Cu short wire have effect on increasing coefficient of friction of brake shoe material. They form contact plateau at contact surface. At contact surface, the Cu short wires which have parallel orientation to the sliding contact were susceptible to detach from the matrix.

The reliability of the Adelaide in-shoe foot model.

Science.gov (United States)

Bishop, Chris; Hillier, Susan; Thewlis, Dominic

2017-07-01

Understanding the biomechanics of the foot is essential for many areas of research and clinical practice such as orthotic interventions and footwear development. Despite the widespread attention paid to the biomechanics of the foot during gait, what largely remains unknown is how the foot moves inside the shoe. This study investigated the reliability of the Adelaide In-Shoe Foot Model, which was designed to quantify in-shoe foot kinematics and kinetics during walking. Intra-rater reliability was assessed in 30 participants over five walking trials whilst wearing shoes during two data collection sessions, separated by one week. Sufficient reliability for use was interpreted as a coefficient of multiple correlation and intra-class correlation coefficient of >0.61. Inter-rater reliability was investigated separately in a second sample of 10 adults by two researchers with experience in applying markers for the purpose of motion analysis. The results indicated good consistency in waveform estimation for most kinematic and kinetic data, as well as good inter-and intra-rater reliability. The exception is the peak medial ground reaction force, the minimum abduction angle and the peak abduction/adduction external hindfoot joint moments which resulted in less than acceptable repeatability. Based on our results, the Adelaide in-shoe foot model can be used with confidence for 24 commonly measured biomechanical variables during shod walking. Copyright © 2017 Elsevier B.V. All rights reserved.

Nasal Cancer in the Northamptonshire Boot and Shoe Industry

Science.gov (United States)

Acheson, E. D.; Cowdell, R. H.; Jolles, B.

1970-01-01

A survey of the incidence of nasal cancer in Northamptonshire during the period 1953 to 1967 is reported. Of the 46 patients with nasal cancer ascertained during the 15-year period 21 (19 males and 2 females) had been employed at some time in the boot and shoe industry. Five other cases diagnosed either before 1953 or after 1967 in persons who had worked in the boot and shoe industry in Northamptonshire were ascertained from various sources. The incidence of nasal cancer (all histological types considered together) was significantly higher in male boot and shoe operatives in Northamptonshire than in males of all occupational classes in the Cancer Register areas selected for comparison and in males working in other occupations in Northamptonshire. The excess incidence has recently given rise to the occurrence of between 1 and 2 new cases per annum in the Northamptonshire boot and shoe industry. The cases within the Northamptonshire industry occurred almost entirely in the relatively small number of workers who are exposed to the dust of the materials used in the manufacture of footwear. Possibly there are two carcinogenic factors in the industry—one related to the production of nasal adenocarcinoma, and the other to squamous and possibly other types of carcinoma in the nasal cavity and sinuses. This requires further study. Our best estimate of the latent period for the adenocarcinoma cases was 54·6 years, which is substantially longer than for the patients with squamous, transitional, and anaplastic tumours (41·7 years). We have no evidence to answer the question whether the facts are still present in the industrial environment, though undoubtedly the standards of hygiene in the industry has improved substantially since these men were first exposed. There is probably an increased risk of nasal adenocarcinoma in the footwear repairing industry, but this requires further study. Our evidence suggests that snuff taking should be considered as a possible contributory

Effect of shoes containing nanosilica particles on knee valgus in active females during landing

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Zahra Bassiri

2015-01-01

Full Text Available Objective(s: The effect of silica nanoparticles (SNPs in sport shoes outsoles on the  parameters related to anterior cruciate ligament (ACL Injury has not been investigated. The aim of this study was to investigate the effect of shoes outsole containing a composite of thermoplastic elastomer based on styrene-butadiene and silica nanoparticles (TPEN shoe on Knee Valgus Angle (KVA as a risk factor of ACL injuries during landing Materials and Methods: Fourteen active healthy women without knee injuries and disorders performed bilateral drop jump (DJ and single leg drop landing (SLL tasks in barefoot, wearing shoes fabricated with polyvinyl chloride outsole (PVC shoe and TPEN shoes conditions , randomly. The knee valgus angle values of right and left legs were calculated in the landing conditions. Two factors repeated measures ANOVA were used to investigate the effect of landing and footwear conditions on KVA of right and left legs.  Results: For both left and right limbs, the KVA was at maximum and minimum values during landing with barefoot and TPEN shoes, respectively. PVC shoe significantly reduced the knee valgus by 3.84% in left and 4.18% in right knee (P

Evaluating the injury incidence from skate shoes in the United States.

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Ruth, Erin; Shah, Binisa; Fales, Willliam

2009-05-01

The goals of this study were to evaluate whether the increased use of skate shoes may lead to an increase in injuries for children and adolescents aged 5 to 14 years in the United States and to describe the types of injuries reported by emergency departments as a result of skate shoe use. Retrospective analysis of the National Electronic Injury Surveillance System database from January 1, 2002 to December 31, 2006 for injuries resulting from footwear in children and adolescents aged 5 to 14 years. Injuries resulting from skate shoe use were identified by manual review of the data. For the 5-year period, an estimated 3525 patients between 5 and 14 years of age were treated in United States emergency departments for injuries resulting from skate shoe use. The percentage of injuries resulting from skate shoes of total footwear-related injuries varied by year, however, with 1.0%, 1.0%, 0.8%, and 1.9% occurring in 2002 to 2005, respectively, and 11.8% occurring in 2006. This substantial increase in 2006 accounts for 73.6% of skate shoe-related injuries and is statistically significant (chi, P = skate shoe sales, with a correlation coefficient of 0.9982.Most of the injured children and adolescents were white, and there was a slight, nonsignificant predominance of boys. Most injuries in all 5-year-olds were fractures (46.7%), followed by contusions (17.9%) and sprains (17.2%). The most frequent site of fracture was the forearm (38.4%), followed by the wrist (35.1%) and the leg (14.9%). Other injuries included lacerations (7.3%), concussions (6.6%), internal organ injuries (0.9%), hematomas (0.2%), dislocations (0.2%), and injuries not otherwise specified (3.1%). Based on national estimates, 104 (0.01%) patients required admission to the hospital. No injuries recorded in the National Electronic Injury Surveillance System database resulted in death. As the first study analyzing injury rates as a result of skate shoe use in the United States, this study demonstrated a recent

Analysing Factors That Drives Customer Loyalty Of Shoes Laundry Quickcares Manado

OpenAIRE

Mawa, Maria; Tumbuan, Willem J.F.Alfa; Tielung, Maria V.J

2017-01-01

This research is to analyzing what are the factors that drive customer loyalty of shoe laundry Quickcares Manado. Shoe Laundry is the services that offer to clean and taking care shoe, Customer Loyalty is the result of consistently positive emotional experience, physical attribute-based satisfaction and perceived value of an experience, which includes the product or services. It is important to know factors that drive customer Loyalty in business, in order to guarantee business continuity and...

Influence of sports flooring and shoes on impact forces and performance during jump tasks.

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Laurent Malisoux

Full Text Available We aim to determine the influence of sports floorings and sports shoes on impact mechanics and performance during standardised jump tasks. Twenty-one male volunteers performed ankle jumps (four consecutive maximal bounds with very dynamic ankle movements and multi-jumps (two consecutive maximal counter-movement jumps on force plates using minimalist and cushioned shoes under 5 sports flooring (SF conditions. The shock absorption properties of the SF, defined as the proportion of peak impact force absorbed by the tested flooring when compared with a concrete hard surface, were: SF0 = 0% (no flooring, SF1 = 19%, SF2 = 26%, SF3 = 37% and SF4 = 45%. Shoe and flooring effects were compared using 2x5 repeated-measures ANOVA with post-hoc Bonferroni-corrected comparisons. A significant interaction between SF and shoe conditions was found for VILR only (p = 0.003. In minimalist shoes, SF influenced Vertical Instantaneous Loading Rate (VILR during ankle jumps (p = 0.006 and multi-jumps (p<0.001, in accordance with shock absorption properties. However, in cushioned shoes, SF influenced VILR during ankle jumps only (p<0.001. Contact Time was the only additional variable affected by SF, but only during multi-jumps in minimalist shoes (p = 0.037. Cushioned shoes induced lower VILR (p<0.001 and lower Contact Time (p≤0.002 during ankle jumps and multi-jumps compared to minimalist shoes. During ankle jumps, cushioned shoes induced greater Peak Vertical Ground Reaction Force (PVGRF, p = 0.002, greater Vertical Average Loading Rate (p<0.001, and lower eccentric (p = 0.008 and concentric (p = 0.004 work. During multi-jumps, PVGRF was lower (p<0.001 and jump height was higher (p<0.001 in cushioned compared to minimalist shoes. In conclusion, cushioning influenced impact forces during standardised jump tasks, whether it was provided by the shoes or the sports flooring. VILR is the variable that was the most affected.

Evaluation and Optimization of Therapeutic Footwear for Neuropathic Diabetic Foot Patients Using In-Shoe Plantar Pressure Analysis

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Bus, Sicco A.; Haspels, Rob; Busch-Westbroek, Tessa E.

2011-01-01

OBJECTIVE Therapeutic footwear for diabetic foot patients aims to reduce the risk of ulceration by relieving mechanical pressure on the foot. However, footwear efficacy is generally not assessed in clinical practice. The purpose of this study was to assess the value of in-shoe plantar pressure analysis to evaluate and optimize the pressure-reducing effects of diabetic therapeutic footwear. RESEARCH DESIGN AND METHODS Dynamic in-shoe plantar pressure distribution was measured in 23 neuropathic diabetic foot patients wearing fully customized footwear. Regions of interest (with peak pressure >200 kPa) were selected and targeted for pressure optimization by modifying the shoe or insole. After each of a maximum of three rounds of modifications, the effect on in-shoe plantar pressure was measured. Successful optimization was achieved with a peak pressure reduction of >25% (criterion A) or below an absolute level of 200 kPa (criterion B). RESULTS In 35 defined regions, mean peak pressure was significantly reduced from 303 (SD 77) to 208 (46) kPa after an average 1.6 rounds of footwear modifications (P diabetic foot. This result provides an objective approach to instantly improve footwear quality, which should reduce the risk for pressure-related plantar foot ulcers. PMID:21610125

EVA Moccasin : Creating a research archetype to explore shoe use

NARCIS (Netherlands)

Nachtigall, T.

2017-01-01

In this paper three separate approaches to recording use data are encompassed in a single shoe sole prototype. A shoe sole with electronic and nonelectronic sensors is crafted using 3D printing of flexible materials from programed g-Code. The sole is inserted into a laser cut, 3D printing reinforced

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

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

2016-01-01

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. PMID:27307512

The study of mildew proof effect of 60Co γ irradiation on leather shoes

International Nuclear Information System (INIS)

Wu Caixuan; Deng Zhiqun; Yu Qin; Zeng Daonan; Deng Guili

1992-01-01

Leather products occupy an important place in the national economy. In order to prevent from mildewing of leather products in storage, transportation and sale, the packed shoes were irradiated with 60 Co γ ray. Test materials are cattle, sheep and pig leather shoes. The results shows that: 1. There are 11 types of molds which make leather shoes mildewed: Oospora sp, Rhizopus oryzae Went and Grrelings, Aspergillus flavus Link, Aspergillus terreus thom, Monilia sp, Botrytis sp, Aspergillus niger V. Tiegh, Penicillum Lividum Westling, Penicillum Corylophilum Dieckx, Penicillum Cyaneum (B. and S.) Biourge and Penicillum Verrulosum Peeyrone. 2. The three types of shoes packed with polyethylene film can be prevented from mildewing after irradiation at level of 12 kGy. 3. The irradiation at 30 kGy does not change the physical properties of the shoes. 4. The irradiated shoes packed with polyethylene film can prevent mildewing, but unpacked ones would be mildewed again

Influence of different safety shoes on gait and plantar pressure: a standardized examination of workers in the automotive industry.

Science.gov (United States)

Ochsmann, Elke; Noll, Ulrike; Ellegast, Rolf; Hermanns, Ingo; Kraus, Thomas

2016-09-30

Working conditions, such as walking and standing on hard surfaces, can increase the development of musculoskeletal complaints. At the interface between flooring and musculoskeletal system, safety shoes may play an important role in the well-being of employees. The aim of this study was to evaluate the effects of different safety shoes on gait and plantar pressure distributions on industrial flooring. Twenty automotive workers were individually fitted out with three different pairs of safety shoes ( "normal" shoes, cushioned shoes, and midfoot bearing shoes). They walked at a given speed of 1.5 m/s. The CUELA measuring system and shoe insoles were used for gait analysis and plantar pressure measurements, respectively. Statistical analysis was conducted by ANOVA analysis for repeated measures. Walking with cushioned safety shoes or a midfoot bearing safety shoe led to a significant decrease of the average trunk inclination (pshoes as well as midfoot bearing shoes (pshoes. As expected, plantar pressure distributions varied significantly between cushioned or midfoot bearing shoes and shoes without ergonomic components. The overall function of safety shoes is the avoidance of injury in case of an industrial accident, but in addition, safety shoes could be a long-term preventive instrument for maintaining health of the employees' musculoskeletal system, as they are able to affect gait parameters. Further research needs to focus on safety shoes in working situations.

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

2018-04-01

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.

LOW HANDICAP GOLFERS GENERATE MORE TORQUE AT THE SHOE-NATURAL GRASS INTERFACE WHEN USING A DRIVER

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Paul Worsfold

2008-09-01

Full Text Available The aim was to determine the rotational torque occurring at the shoe-natural grass interface during golf swing performance with different clubs, and to determine the influence of handicap and golf shoe design. Twenty-four golfers (8 low 0-7; 8 medium 8-14; and 8 high 15+ performed 5 shots with a driver, 3-iron and 7-iron when 3 shoes were worn: a modern 8 mm metal 7-spike shoe, an alternative 7-spike shoe and a flat soled shoe. Torque was measured at the front and back foot by grass covered force platforms in an outdoor field. Torque at the shoe- natural turf interface was similar at the front foot when using a driver, 3-iron and 7-iron with maximum mean torque (Tzmax 17-19 Nm and torque generation in the entire backswing and downswing approximately 40 Nm. At the back foot, torque was less than at the front foot when using the driver, 3-iron and 7-iron. At the back foot Tzmax was 6-7 Nm, and torque generation was 10-16 Nm, with a trend for greater torque generation when using the driver rather than the irons. The metal spike shoe allowed significantly more back foot torque generation when using a driver than a flat- soled shoe (p 0.05, although back foot mean torques generated tended to be greater for the metal spike shoe. The golf shot outcomes were similar for low, medium and high handicappers in both metal and alternative spike shoes (metal: 87%; 76%; 54%; alternative: 85%; 74%; 54% respectively. The better, low handicap golfers generated significantly more back foot torque (metal spike: 18.2 Nm; alternative: 15.8 Nm; p < 0.05 when using a driver. Further research should consider back foot shoe-grass interface demands during driver usage by low handicap and lighter body-weight golfers

Effect of soccer shoe upper on ball behaviour in curve kicks

Science.gov (United States)

Ishii, Hideyuki; Sakurai, Yoshihisa; Maruyama, Takeo

2014-08-01

New soccer shoes have been developed by considering various concepts related to kicking, such as curving a soccer ball. However, the effects of shoes on ball behaviour remain unclear. In this study, by using a finite element simulation, we investigated the factors that affect ball behaviour immediately after impact in a curve kick. Five experienced male university soccer players performed one curve kick. We developed a finite element model of the foot and ball and evaluated the validity of the model by comparing the finite element results for the ball behaviour immediately after impact with the experimental results. The launch angle, ball velocity, and ball rotation in the finite element analysis were all in general agreement with the experimental results. Using the validated finite element model, we simulated the ball behaviour. The simulation results indicated that the larger the foot velocity immediately before impact, the larger the ball velocity and ball rotation. Furthermore, the Young's modulus of the shoe upper and the coefficient of friction between the shoe upper and the ball had little effect on the launch angle, ball velocity, and ball rotation. The results of this study suggest that the shoe upper does not significantly influence ball behaviour.

Multibody Dynamic Stress Simulation of Rigid-Flexible Shovel Crawler Shoes

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Samuel Frimpong

2016-06-01

Full Text Available Electric shovels are used in surface mining operations to achieve economic production capacities. The capital investments and operating costs associated with the shovels deployed in the Athabasca oil sands formation are high due to the abrasive conditions. The shovel crawler shoes interact with sharp and abrasive sand particles, and, thus, are subjected to high transient dynamic stresses. These high stresses cause wear and tear leading to crack initiation, propagation and premature fatigue failure. The objective of this paper is to develop a model to characterize the crawler stresses and deformation for the P&H 4100C BOSS during propel and loading using rigid-flexible multi-body dynamic theory. A 3-D virtual prototype model of the rigid-flexible crawler track assembly and its interactions with oil sand formation is simulated to capture the model dynamics within multibody dynamics software MSC ADAMS. The modal and stress shapes and modal loads due to machine weight for each flexible crawler shoes are generated from finite element analysis (FEA. The modal coordinates from the simulation are combined with mode and stress shapes using modal superposition method to calculate real-time stresses and deformation of flexible crawler shoes. The results show a maximum von Mises stress value of 170 MPa occurring in the driving crawler shoe during the propel motion. This study provides a foundation for the subsequent fatigue life analysis of crawler shoes for extending crawler service life.

EFFECT OF SHOE RAISE ALONG WITH MOTOR RELEARNING PROGRAMME (MRP ON AMBULATION IN CHRONIC STROKE

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Gajanan Bhalerao

2016-06-01

Full Text Available Background: Stroke subjects face reduced tolerance to activity and sedentary lifestyle due to various impairments, such as muscle weakness, pain, spasticity, and poor balance. Thus, loss of independent ambulation especially outdoors is generally observed in them. Methods: Chronic stroke patients (> 6 months with Functional Ambulation Category score > 2 and able to walk at least 10 meters of distance with and without assistance from a tertiary healthcare centre were selected and treated. Subjects were randomly divided into 2 groups control group (n=14 and experimental group (n=13. Each group received Motor Relearning Programme for 60 minutes, 6 times a week for 4 weeks. The experimental group received an additional shoe-raise of 1 cm on the unaffected side along with while ambulating during therapy as well as at home. Pre and post treatment the patients were assessed for spatio-temporal parameters using foot print analysis method and Rivermead Visual Gait Assessment (RVGA Score using RVGA scale. Results: There was significant improvement seen in almost all the spatio-temporal gait parameters and RVGA score in within group analysis. Whereas on between group the results from between group comparison suggests that subjects in MRP with shoe-raise group showed better results in spatio-temporal parameters of gait than subjects receiving MRPalone. But there was no additional benefit of shoe-raise seen on RGVA score and angle of toe-out parameter. Conclusion: Additional use of shoe-raise helps to improve spatio-temporal gait parameters. However, there was no additional change seen in RVGA score.

Shoe adaptation after amputation of the II - V phalangeal bones of the foot.

Science.gov (United States)

Rommers, G M; Diepstraten, H J M; Bakker, E; Lindeman, E

2006-12-01

In The Netherlands, about 50% of all amputations of the lower limb are toes and forefoot amputations. Traumata of toes and mid-foot are rare. Preservation of the foot is the primary goal for treatment. Crush injuries of the foot may be associated with prolonged morbidity. This case study presents an insole solution for the solitary first phalangeal bone after amputation of the phalangeal bones II - V. The normal adaptation for forefoot amputations is stiffening of the sole of the shoe and a rocker bar to improve the toe off phase with load reduction of the forefoot. Because the patient had to do excessive stair climbing during work another solution was chosen. As a foot orthosis, a metal soleplate was made in order to have free movement during loading and toe-off during walking. The soleplate gives safety and provides self-adjusting properties after toe off. This enables the shoe technician to make a shoe without a rocker bar or an extra stiff insole. The 0.5 mm custom-made spring-steel plate is also used as a protective in industrial safety shoes. To improve shoe adaptation more research and case reports have to be published in order to inform doctors and shoe technicians about everyday solutions to partial foot amputations.

The influence of cadence and shoes on patellofemoral joint kinetics in runners with patellofemoral pain.

Science.gov (United States)

Bonacci, Jason; Hall, Michelle; Fox, Aaron; Saunders, Natalie; Shipsides, Tristan; Vicenzino, Bill

2018-06-01

To determine the effect of a combination of a minimalist shoe and increased cadence on measures of patellofemoral joint loading during running in individuals with patellofemoral pain. Within-participant repeated measures with four conditions presented in random order: (1) control shoe at preferred cadence; (2) control shoe with +10% cadence; (3) minimalist shoe at preferred cadence; (4) minimalist shoe with +10% cadence. Fifteen recreational runners with patellofemoral pain ran on an instrumented treadmill while three-dimensional motion capture data were acquired. Peak patellofemoral joint stress, joint reaction force, knee extensor moment and knee joint angle during the stance phase of running were calculated. One-way repeated measures ANOVA was used to compare the control condition (1) to the three experimental conditions (2-4). Running in a minimalist shoe at an increased cadence reduced patellofemoral stress and joint reaction force on average by approximately 29% (ppatellofemoral joint stress by 15% and joint reaction force by 17% (ppatellofemoral joint stress and joint reaction force by 16% and 19% (ppatellofemoral pain, running in a minimalist shoe at an increased cadence had the greatest reduction in patellofemoral joint loading compared to a control shoe at preferred cadence. This may be an effective intervention to modulate biomechanical factors related to patellofemoral pain. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

CAD-based intelligent robot system integrated with 3D scanning for shoe roughing and cementing

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Chiu Cheng-Chang

2017-01-01

Full Text Available Roughing and cementing are very essential to the process of bonding shoe uppers and the corresponding soles; however, for shoes with complicated design, such as sport shoes, roughing and cementing greatly relied on manual operation. Recently, shoe industry is progressing to 3D design, thus 3D model of the shoe upper and sole will be created before launching into mass production. Taking advantage of the 3D model, this study developed a plug-in program on Rhino 3D CAD platform, which realized the complicated roughing and cementing route planning to be performed by the plug-in program, integrated with real-time 3D scanning information to compensate the planned route, and then converted to working trajectory of robot arm to implement roughing and cementing. The proposed 3D CAD-based intelligent robot arm system integrated with 3D scanning for shoe roughing and cementing is realized and proved to be feasible.

Mobile gait analysis via eSHOEs instrumented shoe insoles: a pilot study for validation against the gold standard GAITRite®.

Science.gov (United States)

Jagos, Harald; Pils, Katharina; Haller, Michael; Wassermann, Claudia; Chhatwal, Christa; Rafolt, Dietmar; Rattay, Frank

2017-07-01

Clinical gait analysis contributes massively to rehabilitation support and improvement of in-patient care. The research project eSHOE aspires to be a useful addition to the rich variety of gait analysis systems. It was designed to fill the gap of affordable, reasonably accurate and highly mobile measurement devices. With the overall goal of enabling individual home-based monitoring and training for people suffering from chronic diseases, affecting the locomotor system. Motion and pressure sensors gather movement data directly on the (users) feet, store them locally and/or transmit them wirelessly to a PC. A combination of pattern recognition and feature extraction algorithms translates the motion data into standard gait parameters. Accuracy of eSHOE were evaluated against the reference system GAITRite in a clinical pilot study. Eleven hip fracture patients (78.4 ± 7.7 years) and twelve healthy subjects (40.8 ± 9.1 years) were included in these trials. All subjects performed three measurements at a comfortable walking speed over 8 m, including the 6-m long GAITRite mat. Six standard gait parameters were extracted from a total of 347 gait cycles. Agreement was analysed via scatterplots, histograms and Bland-Altman plots. In the patient group, the average differences between eSHOE and GAITRite range from -0.046 to 0.045 s and in the healthy group from -0.029 to 0.029 s. Therefore, it can be concluded that eSHOE delivers adequately accurate results. Especially with the prospect as an at home supplement or follow-up to clinical gait analysis and compared to other state of the art wearable motion analysis systems.

Sporadic wind wave horse-shoe patterns

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S. Yu. Annenkov

1999-01-01

Full Text Available The work considers three-dimensional crescent-shaped patterns often seen on water surface in natural basins and observed in wave tank experiments. The most common of these 'horse-shoe-like' patterns appear to be sporadic, i.e., emerging and disappearing spontaneously even under steady wind conditions. The paper suggests a qualitative model of these structures aimed at explaining their sporadic nature, physical mechanisms of their selection and their specific asymmetric form. First, the phenomenon of sporadic horse-shoe patterns is studied numerically using the novel algorithm of water waves simulation recently developed by the authors (Annenkov and Shrira, 1999. The simulations show that a steep gravity wave embedded into widespectrum primordial noise and subjected to small nonconservative effects typically follows the simple evolution scenario: most of the time the system can be considered as consisting of a basic wave and a single pair of oblique satellites, although the choice of this pair tends to be different at different instants. Despite the effective low-dimensionality of the multimodal system dynamics at relatively sho ' rt time spans, the role of small satellites is important: in particular, they enlarge the maxima of the developed satellites. The presence of Benjamin-Feir satellites appears to be of no qualitative importance at the timescales under consideration. The selection mechanism has been linked to the quartic resonant interactions among the oblique satellites lying in the domain of five-wave (McLean's class II instability of the basic wave: the satellites tend to push each other out of the resonance zone due to the frequency shifts caused by the quartic interactions. Since the instability domain is narrow (of order of cube of the basic wave steepness, eventually in a generic situation only a single pair survives and attains considerable amplitude. The specific front asymmetry is found to result from the interplay of quartic

A Novel Method for Measuring In-Shoe Navicular Drop during Gait

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Henrik Karstoft

2012-08-01

Full Text Available Analysis of foot movement is essential in the treatment and prevention of foot-related disorders. Measuring the in-shoe foot movement during everyday activities, such as sports, has the potential to become an important diagnostic tool in clinical practice. The current paper describes the development of a thin, flexible and robust capacitive strain sensor for the in-shoe measurement of the navicular drop. The navicular drop is a well-recognized measure of foot movement. The position of the strain sensor on the foot was analyzed to determine the optimal points of attachment. The sensor was evaluated against a state-of-the-art video-based system that tracks reflective markers on the bare foot. Preliminary experimental results show that the developed strain sensor is able to measure navicular drop on the bare foot with an accuracy on par with the video-based system and with a high reproducibility. Temporal comparison of video-based, barefoot and in-shoe measurements indicate that the developed sensor measures the navicular drop accurately in shoes and can be used without any discomfort for the user.

Ipsilateral deficits in 1-handed shoe tying after left or right hemisphere stroke.

Science.gov (United States)

Poole, Janet L; Sadek, Joseph; Haaland, Kathleen Y

2009-10-01

Poole JL, Sadek J, Haaland KY. Ipsilateral deficits in 1-handed shoe tying after left or right hemisphere stroke. To examine 1-handed shoe tying performance and whether cognitive deficits more associated with left or right hemisphere damage differentially affect it after unilateral stroke. Observational cohort comparing ipsilesional shoe tying, spatial and language skills, and limb praxis. Primary care Veterans Affairs and private medical center. Not applicable. Volunteer right-handed sample of adults with left or right hemisphere damage and healthy demographically matched adults. The number of correct trials and the total time to complete 10 trials tying a shoe using the 1-handed method. Both stroke groups had fewer correct trials and were significantly slower tying the shoe than the control group. Spatial skills predicted accuracy and speed after right hemisphere damage. After left hemisphere damage, accuracy was predicted by spatial skills and limb praxis, while speed was predicted by limb praxis only. Ipsilesional shoe tying is similarly impaired after left or right hemisphere damage, but for different reasons. Spatial deficits had a greater influence after right hemisphere damage, and limb apraxia had a greater influence after left hemisphere damage. Language deficits did not affect performance, indicating that aphasia does not preclude using this therapy approach. These results suggest that rehabilitation professionals should consider assessment of limb apraxia and ipsilesional skill training in the performance of everyday tasks.

Does Shoe Collar Height Influence Ankle Joint Kinematics and Kinetics in Sagittal Plane Maneuvers?

Science.gov (United States)

Yang, Yang; Fang, Ying; Zhang, Xini; He, Junliang; Fu, Weijie

2017-01-01

The Objective of the study is to investigate the effects of basketball shoes with different collar heights on ankle kinematics and kinetics and athletic performance in different sagittal plane maneuvers. Twelve participants who wore high-top and low-top basketball shoes (hereafter, HS and LS, respectively) performed a weight-bearing dorsiflexion (WB-DF) maneuver, drop jumps (DJs), and lay-up jumps (LJs). Their sagittal plane kinematics and ground reaction forces were recorded using the Vicon motion capture system and Kistler force plates simultaneously. Moreover, ankle dorsiflexion and plantarflexion angles, moment, power, stiffness, and jump height were calculated. In the WB-DF test, the peak ankle dorsiflexion angle (p = 0.041) was significantly smaller in HS than in LS. Additionally, the peak ankle plantarflexion moment (p = 0.028) and power (p = 0.022) were significantly lower in HS than in LS during LJs but not during DJs. In both jumping maneuvers, no significant differences were found in the jump height or ankle kinematics between the two shoe types. According to the WB-DF test, increasing shoe collar height can effectively reduce the ankle range of motion in the sagittal plane. Although the HS did not restrict the flexion–extension performance of the ankle joint during two jumping maneuvers, an increased shoe collar height can reduce peak ankle plantarflexion moment and peak power during the push-off phase in LJs. Therefore, a higher shoe collar height should be used to circumvent effects on the partial kinetics of the ankle joint in the sagittal plane. Key points An increased shoe collar height effectively reduced ankle joint ROM in the sagittal plane in weight-bearing dorsiflexion maneuver. Shoe collar height did not affect sagittal plane ankle kinematics and had no effect on performance during realistic jumping. Shoe collar height can affect the ankle plantarflexion torque and peak power during the push-off phase in lay-up jump. PMID:29238255

A COMPARISON OF GOLF SHOE DESIGNS HIGHLIGHTS GREATER GROUND REACTION FORCES WITH SHORTER IRONS

Directory of Open Access Journals (Sweden)

Paul Worsfold

2007-12-01

Full Text Available In an effort to reduce golf turf damage the traditional metal spike golf shoe has been redesigned, but shoe-ground biomechanical evaluations have utilised artificial grass surfaces. Twenty-four golfers wore three different golf shoe traction designs (traditional metal spikes, alternative spikes, and a flat-soled shoe with no additional traction when performing shots with a driver, 3 iron and 7 iron. Ground action forces were measured beneath the feet by two natural grass covered force platforms. The maximum vertical force recorded at the back foot with the 3 iron and 7 iron was 0.82 BW (body weight and at the front foot 1.1 BW approximately in both the metal spike and alternative spike golf shoe designs. When using the driver these maximal vertical values were 0.49 BW at the back foot and 0.84 BW at the front foot. Furthermore, as performance of the backswing and then downswing necessitates a change in movement direction the range of force generated during the complete swing was calculated. In the metal spike shoe the vertical force generated at the back foot with both irons was 0.67 BW and at the front foot 0.96 BW with the 3 iron and 0.92 BW with the 7 iron. The back foot vertical force generated with the driver was 0.33 BW and at the front foot 0.83 BW wearing the metal spike shoe. Results indicated the greater force generation with the irons. When using the driver the more horizontal swing plane associated with the longer club reduced vertical forces at the back and front foot. However, the mediolateral force generated across each foot in the metal and alternative spike shoes when using the driver was greater than when the irons were used. The coefficient of friction was 0. 62 at the back and front foot whichever shoe was worn or club used

Exposure to chrysotile asbestos associated with unpacking and repacking boxes of automobile brake pads and shoes.

Science.gov (United States)

Madl, A K; Scott, L L; Murbach, D M; Fehling, K A; Finley, B L; Paustenbach, D J

2008-08-01

Industrial hygiene surveys and epidemiologic studies of auto mechanics have shown that these workers are not at an increased risk of asbestos-related disease; however, concerns continue to be raised regarding asbestos exposure from asbestos-containing brakes. Handling new asbestos-containing brake components has recently been suggested as a potential source of asbestos exposure. A simulation study involving the unpacking and repacking of 105 boxes of brakes (for vehicles ca. 1946-80), including 62 boxes of brake pads and 43 boxes of brake shoes, was conducted to examine how this activity might contribute to both short-term and 8-h time-weighted average exposures to asbestos. Breathing zone samples on the lapel of a volunteer worker (n = 80) and area samples at bystander (e.g., 1.5 m from worker) (n = 56), remote area (n = 26) and ambient (n = 10) locations collected during the unpacking and repacking of boxes of asbestos-containing brakes were analyzed by phase contrast microscopy and transmission electron microscopy. Exposure to airborne asbestos was characterized for a variety of parameters including the number of boxes handled, brake type (i.e. pads versus shoes) and the distance from the activity (i.e. worker, bystander and remote area). This study also evaluated the fiber size and morphology distribution according to the International Organization for Standardization analytical method for asbestos. It was observed that (i) airborne asbestos concentrations increased with the number of boxes unpacked and repacked, (ii) handling boxes of brake pads resulted in higher worker asbestos exposures compared to handling boxes of brake shoes, (iii) cleanup and clothes-handling tasks produced less airborne asbestos than handling boxes of brakes and (iv) fiber size and morphology analysis showed that while the majority of fibers were free (e.g. not associated with a cluster or matrix), 20 microm length) considered to pose the greatest risk of asbestos-related disease. It

Contact dermatitis caused by a new rubber compound detected in canvas shoes

NARCIS (Netherlands)

Hulstaert, Eva; Bergendorff, Ola; Persson, Christina; Goossens, An; Gilissen, Liesbeth; Engfeldt, Malin; Bruze, Magnus; Schuttelaar, Marie L.; Meijer, Joost M; Lapeere, Hilde

Background. In 2015 and 2016, female patients in Flanders consulted a dermatologist because they developed skin lesions after wearing a specific brand of canvas shoes. Objectives. To identify the culprit allergen in the shoes. Methods. Eighteen young females aged 14-22 years presented with itching

Shoe Orthotics for the Treatment of Chronic Low Back Pain: A Randomized Controlled Trial.

Science.gov (United States)

Cambron, Jerrilyn A; Dexheimer, Jennifer M; Duarte, Manuel; Freels, Sally

2017-09-01

To investigate the efficacy of shoe orthotics with and without chiropractic treatment for chronic low back pain compared with no treatment. Randomized controlled trial. Integrative medicine teaching clinic at a university. Adult subjects (N=225) with symptomatic low back pain of ≥3 months were recruited from a volunteer sample. Subjects were randomized into 1 of 3 treatment groups (shoe orthotic, plus, and waitlist groups). The shoe orthotic group received custom-made shoe orthotics. The plus group received custom-made orthotics plus chiropractic manipulation, hot or cold packs, and manual soft tissue massage. The waitlist group received no care. The primary outcome measures were change in perceived back pain (numerical pain rating scale) and functional health status (Oswestry Disability Index) after 6 weeks of study participation. Outcomes were also assessed after 12 weeks and then after an additional 3, 6, and 12 months. After 6 weeks, all 3 groups demonstrated significant within-group improvement in average back pain, but only the shoe orthotic and plus groups had significant within-group improvement in function. When compared with the waitlist group, the shoe orthotic group demonstrated significantly greater improvements in pain (Ppain (P=.3431). Group differences at 12 weeks and later were not significant. Six weeks of prescription shoe orthotics significantly improved back pain and dysfunction compared with no treatment. The addition of chiropractic care led to higher improvements in function. Copyright © 2017 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Redistribution of Mechanical Work at the Knee and Ankle Joints During Fast Running in Minimalist Shoes.

Science.gov (United States)

Fuller, Joel T; Buckley, Jonathan D; Tsiros, Margarita D; Brown, Nicholas A T; Thewlis, Dominic

2016-10-01

Minimalist shoes have been suggested as a way to alter running biomechanics to improve running performance and reduce injuries. However, to date, researchers have only considered the effect of minimalist shoes at slow running speeds. To determine if runners change foot-strike pattern and alter the distribution of mechanical work at the knee and ankle joints when running at a fast speed in minimalist shoes compared with conventional running shoes. Crossover study. Research laboratory. Twenty-six trained runners (age = 30.0 ± 7.9 years [age range, 18-40 years], height = 1.79 ± 0.06 m, mass = 75.3 ± 8.2 kg, weekly training distance = 27 ± 15 km) who ran with a habitual rearfoot foot-strike pattern and had no experience running in minimalist shoes. Participants completed overground running trials at 18 km/h in minimalist and conventional shoes. Sagittal-plane kinematics and joint work at the knee and ankle joints were computed using 3-dimensional kinematic and ground reaction force data. Foot-strike pattern was classified as rearfoot, midfoot, or forefoot strike based on strike index and ankle angle at initial contact. We observed no difference in foot-strike classification between shoes (χ 2 1 = 2.29, P = .13). Ankle angle at initial contact was less (2.46° versus 7.43°; t 25 = 3.34, P = .003) and strike index was greater (35.97% versus 29.04%; t 25 = 2.38, P = .03) when running in minimalist shoes compared with conventional shoes. We observed greater negative (52.87 J versus 42.46 J; t 24 = 2.29, P = .03) and positive work (68.91 J versus 59.08 J; t 24 = 2.65, P = .01) at the ankle but less negative (59.01 J versus 67.02 J; t 24 = 2.25, P = .03) and positive work (40.37 J versus 47.09 J; t 24 = 2.11, P = .046) at the knee with minimalist shoes compared with conventional shoes. Running in minimalist shoes at a fast speed caused a redistribution of work from the knee to the ankle joint. This finding suggests that runners changing from conventional to minimalist

Antropometric parameters problem solving of shoe lasts by deforming membranes with medium weight

Science.gov (United States)

Albu, A. V.; Anghel Drugarin, C. V.; Barla, E. M.; Porav, V.

2018-01-01

The paper presents research results into getting a virtual model of shoe last and anthropometric parameters change. The most important change occurs in the fingers region. Alternatives CAD-CAM technology for next generation is based on DELCAM software for the CAM procedure and simulation of MATLAB software. This research has led to the virtual changes of the last, anthropometric parameter - the width of the fingers (ld) and shoe last length - (Lp) and images have been achieved with the representation in section of the shoe last changed from the original shoe lasts by FEM method (Finite element method) in MATLAB environment. The results are applied in the textile industry and in the elaboration of linings consumption or in the development of leather substitutes on fabric, knitted or woven material type.

49 CFR 236.801 - Shoe, latch.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Shoe, latch. 236.801 Section 236.801 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.801...

Modified Distal Shoe Appliance for Premature Loss of Multiple Deciduous Molars: A Case Report

OpenAIRE

Bhat, Prasanna Kumar; K., Navin H.; Idris, Mohammed; Christopher, Pradeep; Rai, Niharika

2014-01-01

Preservation of the primary dentition until the normal time of exfoliation is one of the most important factor involved in preventive and interceptive dentistry. The premature loss of second primary molar before the eruption of permanent first molar can create a significant arch space/tooth size discrepancy. Distal shoe space maintainer is a valuable part of the Paediatric Dentist’s armamentarium in those cases where the second primary molar is prematurely lost and it helps to guide the first...

Effects of an unstable shoe construction on balance in women aged over 50 years

DEFF Research Database (Denmark)

Ramstrand, Nerrolyn; Thuesen, Anna Helena; Nielsen, Dennis Brandborg

2010-01-01

BACKGROUND: Shoes with an unstable sole construction are commonly used as a therapeutic tool by physiotherapists and are widely available from shoe and sporting goods retailers. The aim of this study was to investigate the effects of using an unstable shoe (Masai Barefoot Technology) on standing ....... INTERPRETATION: Results from the present study suggest that, for this group of individuals, use of unstable footwear may improve certain aspects of balance....

Inherent variation in multiple shoe-sole test impressions.

Science.gov (United States)

Shor, Yaron; Wiesner, Sarena; Tsach, Tsadok; Gurel, Ron; Yekutieli, Yoram

2018-04-01

Shoeprints left at crime scenes are seldom perfect. Many prints are distorted or contaminated by various materials. Noisy background often contributes to vagueness on the shoeprints as well. Test impressions made from the suspect's shoes in the laboratory are considered a genuine replication of the shoe-sole. This naïve attitude is far from being correct. Consecutive test impressions made in the laboratory under strict similar conditions revealed differences among the exemplars of the same sole. Some of them are minor, but some are major, and can mislead the less experienced practitioners during the comparison process. This article focuses on the inherent within source variability between controlled shoeprints made from the same shoe, as it appears on the RACs. To describe and analyze this variability, repeated test impressions were prepared, and datasets were created. Several RACs were marked on each test impression, using an expert assisting software tool (developed in the authors' lab). The variance in repeated test impressions is demonstrated and possible sources are discussed. This variance should be considered when trying to establish the degree of matching between individual characteristics. Copyright © 2017. Published by Elsevier B.V.

Comparison of plantar pressure distribution between three different shoes and three common movements in futsal.

Science.gov (United States)

Teymouri, Meghdad; Halabchi, Farzin; Mirshahi, Maryam; Mansournia, Mohammad Ali; Mousavi Ahranjani, Ali; Sadeghi, Amir

2017-01-01

Analysis of in-shoe pressure distribution during sport-specific movements may provide a clue to improve shoe design and prevent injuries. This study compared the mean and the peak pressures over the whole foot and ten separate areas of the foot, wearing different shoes during specific movements. Nine male adult recreational futsal players performed three trials of three sport-specific movements (shuffle, sprint and penalty kick), while they were wearing three brands of futsal shoes (Adidas, Lotto and Tiger). Plantar pressures on dominant feet were collected using the F-SCAN system. Peak and mean pressures for whole foot and each separate area were extracted. For statistical analysis, the mean differences in outcome variables between different shoes and movements were estimated using random-effects regression model using STATA ver.10. In the average calculation of the three movements, the peak pressure on the whole foot in Adidas shoe was less than Lotto [8.8% (CI95%: 4.1-13.6%)] and Tiger shoes [11.8% (CI95%:7-16.7%)], (P<0.001). Also, the recorded peak pressure on the whole foot in penalty kick was 61.1% (CI95%: 56.3-65.9%) and 57.6% (CI95%: 52.8-62.3%) less than Shuffle and Sprint tests, respectively (P<0.001). Areas with the highest peak pressure during all 3 movements were not different between all shoes. This area was medial forefoot in cases of shuffle and sprint movements and medial heel in case of penalty kick.

Comparison of plantar pressure distribution between three different shoes and three common movements in futsal.

Directory of Open Access Journals (Sweden)

Meghdad Teymouri

Full Text Available Analysis of in-shoe pressure distribution during sport-specific movements may provide a clue to improve shoe design and prevent injuries. This study compared the mean and the peak pressures over the whole foot and ten separate areas of the foot, wearing different shoes during specific movements.Nine male adult recreational futsal players performed three trials of three sport-specific movements (shuffle, sprint and penalty kick, while they were wearing three brands of futsal shoes (Adidas, Lotto and Tiger. Plantar pressures on dominant feet were collected using the F-SCAN system. Peak and mean pressures for whole foot and each separate area were extracted. For statistical analysis, the mean differences in outcome variables between different shoes and movements were estimated using random-effects regression model using STATA ver.10.In the average calculation of the three movements, the peak pressure on the whole foot in Adidas shoe was less than Lotto [8.8% (CI95%: 4.1-13.6%] and Tiger shoes [11.8% (CI95%:7-16.7%], (P<0.001. Also, the recorded peak pressure on the whole foot in penalty kick was 61.1% (CI95%: 56.3-65.9% and 57.6% (CI95%: 52.8-62.3% less than Shuffle and Sprint tests, respectively (P<0.001.Areas with the highest peak pressure during all 3 movements were not different between all shoes. This area was medial forefoot in cases of shuffle and sprint movements and medial heel in case of penalty kick.

Modified distal shoe appliance--fabrication and clinical performance.

Science.gov (United States)

Gujjar, Kumar Raghav; Indushekar, K R; Amith, H V; Sharma, Shefali Li

2012-01-01

When the primary second molar is prematurely lost, mesial movement and migration of the permanent first molar often occurs. This is one of the most difficult problems of the developing dentition confronted by pediatric dentists. Use of a space maintainer that will guide the permanent first molar into its normal position is indicated. In cases with bilateral premature loss of primary molars, the conventional design of distal shoe poses a variety of problems and, therefore, necessitates a customized design for the eruption guidance of permanent first molars. The purpose of this case report is to discuss an innovative design of a distal shoe appliance, which was used with good clinical results.

Does shoe heel design influence ground reaction forces and knee moments during maximum lunges in elite and intermediate badminton players?

Science.gov (United States)

Lam, Wing-Kai; Ryue, Jaejin; Lee, Ki-Kwang; Park, Sang-Kyoon; Cheung, Jason Tak-Man; Ryu, Jiseon

2017-01-01

Lunge is one frequently executed movement in badminton and involves a unique sagittal footstrike angle of more than 40 degrees at initial ground contact compared with other manoeuvres. This study examined if the shoe heel curvature design of a badminton shoe would influence shoe-ground kinematics, ground reaction forces, and knee moments during lunge. Eleven elite and fifteen intermediate players performed five left-forward maximum lunge trials with Rounded Heel Shoe (RHS), Flattened Heel Shoe (FHS), and Standard Heel Shoes (SHS). Shoe-ground kinematics, ground reaction forces, and knee moments were measured by using synchronized force platform and motion analysis system. A 2 (Group) x 3 (Shoe) ANOVA with repeated measures was performed to determine the effects of different shoes and different playing levels, as well as the interaction of two factors on all variables. Shoe effect indicated that players demonstrated lower maximum vertical loading rate in RHS than the other two shoes (P badminton lunge. The differences in impact loads and knee moments between elite and intermediate players may be useful in optimizing footwear design and training strategy to minimize the potential risks for impact related injuries in badminton.

The effect of gait training with shoe inserts on the improvement of pain and gait in sacroiliac joint patients.

Science.gov (United States)

Cho, Byung-Yun; Yoon, Jung-Gyu

2015-08-01

[Purpose] The purpose of the current research was to identify how gait training with shoe inserts affects the pain and gait of sacroiliac joint dysfunction patients. [Subjects and Methods] Thirty subjects were randomly selected and assigned to be either the experimental group (gait training with shoe insert group) or control group. Each group consisted of 15 patients. Pain was measured by Visual Analogue Scale, and foot pressure in a standing position and during gait was measured with a Gateview AFA-50 system (Alpus, Seoul, Republic of Korea). A paired sample t-test was used to compare the pain and gait of the sacroiliac joint before and after the intervention. Correlation between pain and walking after gait training with shoe inserts was examined by Pearson test. The level of significance was set at α=0.05. [Results] It was found that application of the intervention to the experimental group resulted in a significant decrease in sacroiliac joint pain. It was also found that there was a significant correlation between Visual Analogue Scale score and dynamic asymmetric index (r= 0.796) and that there was a negative correlation between Visual Analogue Scale score and forefoot/rear foot peak pressure ratio (r=-0.728). [Conclusion] The results of our analysis lead us to conclude that the intervention with shoe inserts had a significant influence on the pain and gait of sacroiliac joint patients.

Role of EVA viscoelastic properties in the protective performance of a sport shoe: computational studies.

Science.gov (United States)

Even-Tzur, Nurit; Weisz, Ety; Hirsch-Falk, Yifat; Gefen, Amit

2006-01-01

Modern sport shoes are designed to attenuate mechanical stress waves, mainly through deformation of the viscoelastic midsole which is typically made of ethylene vinyl acetate (EVA) foam. Shock absorption is obtained by flow of air through interconnected air cells in the EVA during shoe deformation under body-weight. However, when the shoe is overused and air cells collapse or thickness of the EVA is reduced, shock absorption capacity may be affected, and this may contribute to running injuries. Using lumped system and finite element models, we studied heel pad stresses and strains during heel-strike in running, considering the viscoelastic constitutive behavior of both the heel pad and EVA midsole. In particular, we simulated wear cases of the EVA, manifested in the modeling by reduced foam thickness, increased elastic stiffness, and shorter stress relaxation with respect to new shoe conditions. Simulations showed that heel pad stresses and strains were sensitive to viscous damping of the EVA. Wear of the EVA consistently increased heel pad stresses, and reduced EVA thickness was the most influential factor, e.g., for a 50% reduction in thickness, peak heel pad stress increased by 19%. We conclude that modeling of the heel-shoe interaction should consider the viscoelastic properties of the tissue and shoe components, and the age of the studied shoe.

Computer vision for shoe upper profile measurement via upper and sole conformal matching

Science.gov (United States)

Hu, Zhongxu; Bicker, Robert; Taylor, Paul; Marshall, Chris

2007-01-01

This paper describes a structured light computer vision system applied to the measurement of the 3D profile of shoe uppers. The trajectory obtained is used to guide an industrial robot for automatic edge roughing around the contour of the shoe upper so that the bonding strength can be improved. Due to the specific contour and unevenness of the shoe upper, even if the 3D profile is obtained using computer vision, it is still difficult to reliably define the roughing path around the shape. However, the shape of the corresponding shoe sole is better defined, and it is much easier to measure the edge using computer vision. Therefore, a feasible strategy is to measure both the upper and sole profiles, and then align and fit the sole contour to the upper, in order to obtain the best fit. The trajectory of the edge of the desired roughing path is calculated and is then smoothed and interpolated using NURBS curves to guide an industrial robot for shoe upper surface removal; experiments show robust and consistent results. An outline description of the structured light vision system is given here, along with the calibration techniques used.

Evaluation of radiation exposure from shoe-deodorants as radioactive consumer products

International Nuclear Information System (INIS)

Furuta, Etsuko; Yokota, Shigeaki; Aburai, Tamaru; Yoshizawa, Yukio

2007-01-01

Six shoe-deodorants on the market were analyzed using gamma-ray spectroscopy and radionuclide imaging techniques. The results reveal that at least three deodorants were 'radioactive consumer products' containing radionuclides of thorium (Th) series, uranium series, and potassium-40 that were added intentionally. Equivalent dose rates and effective dose rates were calculated using the activities in these deodorants. There were no samples breaking the nuclear reactor and fuel regulation law. Radioactive concentration of the deodorant for a shoe-shelf is higher than other deodorants, and the total concentrations of daughter nuclides of Th which are radioactive equilibrium with 224 Ra exceeded 90 Bq·g -1 . The effective dose rate at one meter from the shoe-shelf-deodorant is 8.6x10 -4 μSv·h -1 . Another type of shoe-deodorants is an insole that causes the surface dose of plantar skin. The equivalent dose was calculated as 1.9 μSv·h -1 at one millimeter from the insole. This study suggested that it needs to watch severely over the deodorants because many kinds of deodorants are used in home and some deodorants are radioactive consumer products. (author)

SAFETY SHOES WEARER'S COMFORT PERCEPTION AND EFFECTS AMONG MANUFACTURING EMPLOYEES

OpenAIRE

Deros, Baba Md; Rahman, Mohd Iezalman Ab; Baba, Nurul Huda; Yusof, Ahmed Rithauddeen

2017-01-01

This study investigates ergonomicproblems faced by manufacturing employees due to wearing inappropriate safetyshoes. A total of 30 survey respondents was recruited based on the shoes theywear. Pedar-X was used in the experiment to measure the pressure that acts onthe wearer’ feet. Survey results showed the wearer’ experienced the highestpain with the frequency of 80% for right and 83.33% for the left heel forwearing safety shoes two to three times a week. Meanwhile, Pedar-X recordedaverage pe...

The Preferred Movement Path Paradigm: Influence of Running Shoes on Joint Movement.

Science.gov (United States)

Nigg, Benno M; Vienneau, Jordyn; Smith, Aimée C; Trudeau, Matthieu B; Mohr, Maurice; Nigg, Sandro R

2017-08-01

(A) To quantify differences in lower extremity joint kinematics for groups of runners subjected to different running footwear conditions, and (B) to quantify differences in lower extremity joint kinematics on an individual basis for runners subjected to different running footwear conditions. Three-dimensional ankle and knee joint kinematics were collected for 35 heel-toe runners when wearing three different running shoes and when running barefoot. Absolute mean differences in ankle and knee joint kinematics were computed between running shoe conditions. The percentage of individual runners who displayed differences below a 2°, 3°, and 5° threshold were also calculated. The results indicate that the mean kinematics of the ankle and knee joints were similar between running shoe conditions. Aside from ankle dorsiflexion and knee flexion, the percentage of runners maintaining their movement path between running shoes (i.e., less than 3°) was in the order of magnitude of about 80% to 100%. Many runners showed ankle and knee joint kinematics that differed between a conventional running shoe and barefoot by more than 3°, especially for ankle dorsiflexion and knee flexion. Many runners stay in the same movement path (the preferred movement path) when running in various different footwear conditions. The percentage of runners maintaining their preferred movement path depends on the magnitude of the change introduced by the footwear condition.

The influence of motion control shoes on the running gait of mature and young females.

Science.gov (United States)

Lilley, Kim; Stiles, Vicky; Dixon, Sharon

2013-03-01

This study compared the running gait of mature and young females, and investigated the effect of a motion control shoe. First, it was hypothesised that in a neutral shoe, mature females would display significantly greater rearfoot eversion, knee internal rotation and external adductor moments when compared to a younger group. Secondly, the motion control shoe would reduce rearfoot eversion and knee internal rotation in both groups. Thirdly it was hypothesised that the motion control shoe would increase knee external adductor moment, through an increase in knee varus and moment arm. 15 mature (40-60 years) and 15 young (18-25 years) females performed 10 running trials at 3.5ms(-1)±5% over a force platform. Two shoes were tested, the Adidas Supernova Glide (neutral), and the Adidas Supernova Sequence (motion control). Ankle and knee joint dynamics were analysed for the right leg, and the mean of ten trials was calculated. Joint moments were calculated using inverse dynamics. In the neutral condition, mature females presented greater peak rearfoot eversion, knee internal rotation, and external adductor moments than young females (p<0.05). A motion control shoe significantly reduced peak rearfoot eversion and knee internal rotation among both groups (p<0.05). No between shoe differences in knee external adductor moment were observed. A motion control shoe is recommended to reduce risk of injury associated with rearfoot eversion and knee internal rotation in mature females. However since the knee external adductor moment is a variable commonly associated with medial knee loading it is suggested that alternative design features are required to influence this moment. Copyright © 2012 Elsevier B.V. All rights reserved.

Immediate effect of Masai Barefoot Technology shoes on knee joint moments in women with knee osteoarthritis.

Science.gov (United States)

Tateuchi, Hiroshige; Taniguchi, Masashi; Takagi, Yui; Goto, Yusuke; Otsuka, Naoki; Koyama, Yumiko; Kobayashi, Masashi; Ichihashi, Noriaki

2014-01-01

Footwear modification can beneficially alter knee loading in patients with knee osteoarthritis. This study evaluated the effect of Masai Barefoot Technology shoes on reductions in external knee moments in patients with knee osteoarthritis. Three-dimensional motion analysis was used to examine the effect of Masai Barefoot Technology versus control shoes on the knee adduction and flexion moments in 17 women (mean age, 63.6 years) with radiographically confirmed knee osteoarthritis. The lateral and anterior trunk lean values, knee flexion and adduction angles, and ground reaction force were also evaluated. The influence of the original walking pattern on the changes in knee moments with Masai Barefoot Technology shoes was evaluated. The knee flexion moment in early stance was significantly reduced while walking with the Masai Barefoot Technology shoes (0.25±0.14Nm/kgm) as compared with walking with control shoes (0.30±0.19 Nm/kgm); whereas the knee adduction moment showed no changes. Masai Barefoot Technology shoes did not increase compensatory lateral and anterior trunk lean. The degree of knee flexion moment in the original walking pattern with control shoes was correlated directly with its reduction when wearing Masai Barefoot Technology shoes by multiple linear regression analysis (adjusted R2=0.44, Pknee flexion moment during walking without increasing the compensatory trunk lean and may therefore reduce external knee loading in women with knee osteoarthritis. Copyright © 2014 Elsevier B.V. All rights reserved.

An innovative sealed shoe to off-load and heal diabetic forefoot ulcers - a feasibility study.

Science.gov (United States)

Jarl, Gustav; Tranberg, Roy

2017-01-01

Background : Non-removable knee-high devices are the gold standard to treat diabetic foot ulcers located on the plantar forefoot, but they immobilize the ankle, which restricts daily life activities and has negative effects on joint functioning. Objective : To investigate the feasibility of sealing a therapeutic shoe to off-load and heal diabetic forefoot ulcers. Design : A case series of seven men with type 2 diabetes and a metatarsal head ulcer were prescribed therapeutic shoes and custom-made insoles. The shoe was sealed with a plastic band. Off-loading was assessed with the F-scan pressure measurement system. Adherence to wearing the shoe was assessed with a temperature sensor and by documenting the status of the seal. Results : The off-loading was effective and all ulcers healed. Median time to healing was 56 days (range 8-160). Complications were secondary ulcer ( n  = 1) and plantar hematoma ( n  = 1). Five of seven participants did not disturb the seal. Conclusions : Sealing a therapeutic shoe is a feasible way to off-load and heal forefoot ulcers. A controlled trial is needed to compare the effectiveness and safety of a sealed shoe to other non-removable devices.

Pengaruh Intensitas Mengakses Media Sosial Adidas dan Citra Merek terhadap Keputusan Pembelian Sport Shoes Adidas di Kalangan Remaja Wanita

OpenAIRE

Purnama, Ayu Sri; Herieningsih, Sri Widowati; Pradekso, Tandiyo; Rakhmad, Wiwid Noor

2016-01-01

Sport shoes merupakan salah satu jenis sepatu yang di minati oleh masyarakat saat ini, Selain itu akhir-akhir ini salah satu jenis sport shoes yakni running shoes menjadi fashion baru dikalangan remaja di Indonesia. Namun salah satu produsen sports shoes yaitu adidas saat ini kurang diminati bila dibandingkan dengan kompetitornya hasil survey mengenai sport shoes yang digunakan dan diminati oleh remaja wanita di Indonesia menunjukkan bahwa Adidas menempati urutan ke- tiga setelah nike dan con...

Evaluation of lower limb electromyographic activity when using unstable shoes for the first time: a pilot quasi control trial.

Science.gov (United States)

Branthwaite, Helen; Chockalingam, Nachiappan; Pandyan, Anand; Khatri, Gaurav

2013-08-01

Unstable shoes, which have recently become popular, claim to provide additional physiological and biomechanical advantages to people who wear them. Alterations in postural stability have been shown when using the shoe after training. However, the immediate effect on muscle activity when walking in unstable shoes for the first time has not been investigated. To evaluate muscle activity and temporal parameters of gait when wearing Masai Barefoot Technology shoes(®) for the first time compared to the subject's own regular trainer shoes. A pilot repeated-measures quasi control trial. Electromyographic measurements of lower leg muscles (soleus, medial gastrocnemius, lateral gastrocnemius, tibialis anterior, peroneus longus, rectus femoris, biceps femoris and gluteus medius) were measured in 15 healthy participants using Masai Barefoot Technology shoes and trainer shoes over a 10-m walkway. Muscle activity of the third and sixth steps was used to study the difference in behaviour of the muscles under the two shoe conditions. Temporal parameters were captured with footswitches to highlight heel strike, heel lift and toe off. Paired samples t-test was completed to compare mean muscle activity for Masai Barefoot Technology and trainer shoes. Indicated that the use of Masai Barefoot Technology shoes increased the intensity of the magnitude of muscle activity. While this increase in the activity was not significant across the subjects, there were inter-individual differences in muscle activity. This variance between the participants demonstrates that some subjects do alter muscle behaviour while wearing such shoes. A more rigorous and specific assessment is required when advising patients to purchase the Masai Barefoot Technology shoe. Not all subjects respond positively to using unstable shoes, and the point in time when muscle behaviour can change is variable. Use of Masai Barefoot Technology shoe in patient management should be monitored closely as the individual muscle

Influence of sports flooring and shoes on impact forces and performance during jump tasks.

Science.gov (United States)

Malisoux, Laurent; Gette, Paul; Urhausen, Axel; Bomfim, Joao; Theisen, Daniel

2017-01-01

We aim to determine the influence of sports floorings and sports shoes on impact mechanics and performance during standardised jump tasks. Twenty-one male volunteers performed ankle jumps (four consecutive maximal bounds with very dynamic ankle movements) and multi-jumps (two consecutive maximal counter-movement jumps) on force plates using minimalist and cushioned shoes under 5 sports flooring (SF) conditions. The shock absorption properties of the SF, defined as the proportion of peak impact force absorbed by the tested flooring when compared with a concrete hard surface, were: SF0 = 0% (no flooring), SF1 = 19%, SF2 = 26%, SF3 = 37% and SF4 = 45%. Shoe and flooring effects were compared using 2x5 repeated-measures ANOVA with post-hoc Bonferroni-corrected comparisons. A significant interaction between SF and shoe conditions was found for VILR only (p = 0.003). In minimalist shoes, SF influenced Vertical Instantaneous Loading Rate (VILR) during ankle jumps (p = 0.006) and multi-jumps (pflooring. VILR is the variable that was the most affected.

Development of non-destructive testing system of shoes for infrared rays

Energy Technology Data Exchange (ETDEWEB)

Kim, Jae Yeol; Park, Chang Sun; Oh, Ki Jang; Ma, Sang Dong; Kim, Bong Jae [Chosun Univesity, Kwangju (Korea, Republic of); Yang, Dong Jo [Research Institute of Industrial Science and Technology, Pohang (Korea, Republic of)

2001-05-15

Diagnosis or measurements using Infrared thermo-image hasn't been available. A quick diagnosis and thermal analysis can be possible when that kind of system is introduced to the investigation of each part. In this study, Infrared Camera, Thermo-vision 900 of AGEMA Company was used in order to investigate. Infrared Camera usually detects only Infrared wave from the light in order to illustrate the temperature distribution. Infrared diagnosis system can be applied to various field. But the defect discrimination can be automatic or mechanization on the special shoes total inspection system. Also, it is more effective to development and composition on the shoes total inspection system. In this study, it is introduction method of special shoes nondestructive total inspection. Performance of the proposed method are shown by through thermo-Image.

Does shoe heel design influence ground reaction forces and knee moments during maximum lunges in elite and intermediate badminton players?

Directory of Open Access Journals (Sweden)

Wing-Kai Lam

Full Text Available Lunge is one frequently executed movement in badminton and involves a unique sagittal footstrike angle of more than 40 degrees at initial ground contact compared with other manoeuvres. This study examined if the shoe heel curvature design of a badminton shoe would influence shoe-ground kinematics, ground reaction forces, and knee moments during lunge.Eleven elite and fifteen intermediate players performed five left-forward maximum lunge trials with Rounded Heel Shoe (RHS, Flattened Heel Shoe (FHS, and Standard Heel Shoes (SHS. Shoe-ground kinematics, ground reaction forces, and knee moments were measured by using synchronized force platform and motion analysis system. A 2 (Group x 3 (Shoe ANOVA with repeated measures was performed to determine the effects of different shoes and different playing levels, as well as the interaction of two factors on all variables.Shoe effect indicated that players demonstrated lower maximum vertical loading rate in RHS than the other two shoes (P < 0.05. Group effect revealed that elite players exhibited larger footstrike angle, faster approaching speed, lower peak horizontal force and horizontal loading rates but higher vertical loading rates and larger peak knee flexion and extension moments (P < 0.05. Analysis of Interactions of Group x Shoe for maximum and mean vertical loading rates (P < 0.05 indicated that elite players exhibited lower left maximum and mean vertical loading rates in RHS compared to FHS (P < 0.01, while the intermediate group did not show any Shoe effect on vertical loading rates.These findings indicate that shoe heel curvature would play some role in altering ground reaction force impact during badminton lunge. The differences in impact loads and knee moments between elite and intermediate players may be useful in optimizing footwear design and training strategy to minimize the potential risks for impact related injuries in badminton.

Biomechanical variables and perception of comfort in running shoes with different cushioning technologies.

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Dinato, Roberto C; Ribeiro, Ana P; Butugan, Marco K; Pereira, Ivye L R; Onodera, Andrea N; Sacco, Isabel C N

2015-01-01

To investigate the relationships between the perception of comfort and biomechanical parameters (plantar pressure and ground reaction force) during running with four different types of cushioning technology in running shoes. Randomized repeated measures. Twenty-two men, recreational runners (18-45 years) ran 12km/h with running shoes with four different cushioning systems. Outcome measures included nine items related to perception of comfort and 12 biomechanical measures related to the ground reaction forces and plantar pressures. Repeated measure ANOVAs, Pearson correlation coefficients, and step-wise multiple regression analyses were employed (p≤0.05). No significant correlations were found between the perception of comfort and the biomechanical parameters for the four types of investigated shoes. Regression analysis revealed that 56% of the perceived general comfort can be explained by the variables push-off rate and pressure integral over the forefoot (p=0.015) and that 33% of the perception of comfort over the forefoot can be explained by second peak force and push-off rate (p=0.016). The results did not demonstrate significant relationships between the perception of comfort and the biomechanical parameters for the three types of shoes investigated (Gel, Air, and ethylene-vinyl acetate). Only the shoe with Adiprene+ technology had its general comfort and cushioning perception predicted by the loads over the forefoot. Thus, in general, one cannot predict the perception of comfort of a running shoe through impact and plantar pressure received. Copyright © 2013 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Body Mass and Weekly Training Distance Influence the Pain and Injuries Experienced by Runners Using Minimalist Shoes: A Randomized Controlled Trial.

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Fuller, Joel T; Thewlis, Dominic; Buckley, Jonathan D; Brown, Nicholas A T; Hamill, Joseph; Tsiros, Margarita D

2017-04-01

Minimalist shoes have been popularized as a safe alternative to conventional running shoes. However, a paucity of research is available investigating the longer-term safety of minimalist shoes. To compare running-related pain and injury between minimalist and conventional shoes in trained runners and to investigate interactions between shoe type, body mass, and weekly training distance. Randomized clinical trial; Level of evidence, 2. Sixty-one trained, habitual rearfoot footfall runners (mean ± SD: body mass, 74.6 ± 9.3 kg; weekly training distance, 25 ± 14 km) were randomly allocated to either minimalist or conventional shoes. Runners gradually increased the time spent running in their allocated shoes over 26 weeks. Running-related pain intensity was measured weekly by use of 100-mm visual analog scales. Time to first running-related injury was also assessed. Interactions were found between shoe type and weekly training distance for weekly running-related pain; greater pain was experienced with minimalist shoes ( P 10 mm) were noted when the weekly training distance was more than 35 km/wk. Eleven of 30 runners sustained an injury in conventional shoes compared with 16 of 31 runners in minimalist shoes (hazard ratio, 1.64; 95% confidence interval, 0.63-4.27; P = .31). A shoe × body mass interaction was found for time to first running-related injury ( P = .01). For runners using minimalist shoes, relative to runners using conventional shoes, the risk of sustaining an injury became more likely with increasing body mass above 71.4 kg, and the risk was moderately increased (hazard ratio, 2.00; 95% confidence interval, 1.10-3.66; P = .02) for runners using minimalist shoes who had a body mass of 85.7 kg. Runners should limit weekly training distance in minimalist shoes to avoid running-related pain. Heavier runners are at greater risk of injury when running in minimalist shoes. Registration: Australian New Zealand Clinical Trials Registry (ACTRN12613000642785).

Allergic contact dermatitis caused by dimethylthiocarbamylbenzothiazole sulfide (DMTBS) in canvas shoes: in search of the culprit allergen.

Science.gov (United States)

Schuttelaar, Marie L; Meijer, Joost M; Engfeldt, Malin; Lapeere, Hilde; Goossens, An; Bruze, Magnus; Persson, Christina; Bergendorff, Ola

2018-01-01

During rubber vulcanization, new compounds can be formed. To report a case of allergic shoe dermatitis in which the search for the allergen ultimately led to the identification of dimethylthiocarbamylbenzothiazole sulfide (DMTBS). A female presented with eczema on her feet after wearing Sperry Top Sider® canvas sneakers. Patch testing was performed with the European baseline series, additional series, shoe materials, and extracts of shoe materials. Thin-layer chromatography (TLC) was performed for additional patch testing, and high-performance liquid chromatography and gas chromatography-mass spectometry were used for chemical analysis. Positive reactions were found to thiuram mix (+), tetramethylthiuram monosulfide (TMTM) (+), shoe material (+), and shoe extracts in eth. (++) and acetone (+). The extracts did not contain TMTM or other components of thiuram mix. TLC strips yielded a positive reaction (+) to one spot, whereas chemical analysis gave a negative result. Thereafter, a similar sneaker from another patient with shoe dermatitis was analysed, and DMBTS was identified. New extracts of the shoe of our first patient were then also shown to contain DMTBS. DMTBS as culprit allergen was confirmed by positive patch testing with a dilution series with DMTBS. DMBTS was identified as the culprit allergen in shoe dermatitis, giving rise to compound allergy. The positive reaction to TMTM was considered to represent cross-reactivity. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Single leg balancing in ballet: effects of shoe conditions and poses.

Science.gov (United States)

Lobo da Costa, Paula H; Azevedo Nora, Fernanda G S; Vieira, Marcus Fraga; Bosch, Kerstin; Rosenbaum, Dieter

2013-03-01

The purpose of this study was to describe the effects of lower limb positioning and shoe conditions on stability levels of selected single leg ballet poses performed in demi-pointe position. Fourteen female non-professional ballet dancers (mean age of 18.4±2.8 years and mean body mass index of 21.5±2.8kg/m(2)) who had practiced ballet for at least seven years, without any musculoskeletal impairment volunteered to participate in this study. A capacitive pressure platform allowed for the assessment of center of pressure variables related to the execution of three single leg ballet poses in demi pointé position: attitude devant, attitude derriére, and attitude a la second. Peak pressures, contact areas, COP oscillation areas, anterior-posterior and medio-lateral COP oscillations and velocities were compared between two shoe conditions (barefoot versus slippers) and among the different poses. Barefoot performances produced more stable poses with significantly higher plantar contact areas, smaller COP oscillation areas and smaller anterior-posterior COP oscillations. COP oscillation areas, anterior-posterior COP oscillations and medio-lateral COP velocities indicated that attitude a la second is the least challenging and attitude derriére the most challenging pose. Copyright © 2012 Elsevier B.V. All rights reserved.

Effects of Running Shoes with Abrasion Resistant Rubber Sole on the Exercise Capacity of the Human Body

Directory of Open Access Journals (Sweden)

Bo Wang

2017-10-01

Full Text Available With the development of industrialization, rubber has been gradually used in the manufacture of sports equipment for its favourable properties. This study involved the addition of C5 petroleum resin into brominated isobutylene-isoprene rubber (BIIR and butadiene rubber (BR while manufacturing the sole of running shoes. The effects of running shoes with abrasion resistant rubber sole on the exercise capacity of the human body were investigated by analysing the skid resistance and abrasion resistance of the running shoes, and conducting biomechanical study on naked feet and feet wearing the shoes. The results demonstrated that the rubber sole had favourable slip resistance property and mechanical properties such as stretching, abrasion resistance, and hardness. Compared to naked feet, the peak pressure intensity of the whole step of feet wearing the newly developed shoes, was significantly lower than that of feet wearing ordinary shoes. In the future, rubber can bring more comfortable experience because of its favourable properties.

Novel Thermal Analysis Model of the Foot-Shoe Sole Interface during Gait Motion

Directory of Open Access Journals (Sweden)

Yasuhiro Shimazaki

2018-02-01

Full Text Available Excessive heat at the foot-shoe sole interface negatively affects a human’s thermal comfort. An understanding of the thermal behavior at this interface is important for alleviating this discomfort. During gait motion, a human’s body weight cyclically compresses a shoe sole (commonly constructed of viscoelastic materials, generating heat during loading. To evaluate the thermal effects of this internal heat generation on foot comfort, we developed and empirically validated a thermal analysis model during gait motion. A simple, one-dimensional prediction model for heat conduction with heat generation during compressive loading was used. Heat generation was estimated as a function of the shoe sole’s material properties (e.g., elastic modulus and various gait parameters. When compared with experimental results, the proposed model proved effective in predicting thermal behavior at the foot-shoe sole interface under various conditions and shows potential for improving a human’s thermal comfort during gait motion through informed footwear design.

Statistical fluctuations of an ocean surface inferred from shoes and ships

Science.gov (United States)

Lerche, Ian; Maubeuge, Frédéric

1995-12-01

This paper shows that it is possible to roughly estimate some ocean properties using simple time-dependent statistical models of ocean fluctuations. Based on a real incident, the loss by a vessel of a Nike shoes container in the North Pacific Ocean, a statistical model was tested on data sets consisting of the Nike shoes found by beachcombers a few months later. This statistical treatment of the shoes' motion allows one to infer velocity trends of the Pacific Ocean, together with their fluctuation strengths. The idea is to suppose that there is a mean bulk flow speed that can depend on location on the ocean surface and time. The fluctuations of the surface flow speed are then treated as statistically random. The distribution of shoes is described in space and time using Markov probability processes related to the mean and fluctuating ocean properties. The aim of the exercise is to provide some of the properties of the Pacific Ocean that are otherwise calculated using a sophisticated numerical model, OSCURS, where numerous data are needed. Relevant quantities are sharply estimated, which can be useful to (1) constrain output results from OSCURS computations, and (2) elucidate the behavior patterns of ocean flow characteristics on long time scales.

Shoe heel abrasion and its possible biomechanical cause: a transversal study with infantry recruits.

Science.gov (United States)

Baumfeld, Daniel; Raduan, Fernando C; Macedo, Benjamim; Silva, Thiago Alexandre Alves; Baumfeld, Tiago; Favato, Danilo Fabrino; de Andrade, Marco Antonio Percope; Nery, Caio

2015-11-19

Excessive shoe heel abrasion is of concern to patients and shoe manufacturers, but little scientific information is available about this feature and its possible causes. The purpose of this study was to relate this phenomenon with biomechanical factors that could predispose to shoe heel abrasion. Ninety-seven recruits (median age 25) were enrolled in this study. Shoe abrasion was assessed manually with a metric plastic tape on the posterior part of the heel that comes in contact with the ground. The number of sprains, foot alignment, and calf muscle shortening (Silfverskiold test) was also assessed in order to relate it with shoe heel abrasion. After using our exclusion criteria, 86 recruits and 172 were considered for this study. The most common abrasion site was the lateral portion of the heel surface (50 %). Forty-four percent of the participants had neutral hind-foot alignment and 39 % had valgus alignment. Twenty-six (30 %) patients have had previous ankle or foot sprains. Neutral foot was related with less calf muscle shortening. On the other hand, valgus hind-foot alignment was more associated with Achilles shortening (p study was able to correlate shoe heel abrasion with biomechanical causes (neutral alignment-uniform abrasion/varus alignment-central and lateral abrasion). More effort has to be done to continue evaluating outsole abrasion with its possible biomechanical cause in order to predict and treat possible associated injuries.

Multivariate research in areas of phosphorus cast-iron brake shoes manufacturing using the statistical analysis and the multiple regression equations

Science.gov (United States)

Kiss, I.; Cioată, V. G.; Alexa, V.; Raţiu, S. A.

2017-05-01

The braking system is one of the most important and complex subsystems of railway vehicles, especially when it comes for safety. Therefore, installing efficient safe brakes on the modern railway vehicles is essential. Nowadays is devoted attention to solving problems connected with using high performance brake materials and its impact on thermal and mechanical loading of railway wheels. The main factor that influences the selection of a friction material for railway applications is the performance criterion, due to the interaction between the brake block and the wheel produce complex thermos-mechanical phenomena. In this work, the investigated subjects are the cast-iron brake shoes, which are still widely used on freight wagons. Therefore, the cast-iron brake shoes - with lamellar graphite and with a high content of phosphorus (0.8-1.1%) - need a special investigation. In order to establish the optimal condition for the cast-iron brake shoes we proposed a mathematical modelling study by using the statistical analysis and multiple regression equations. Multivariate research is important in areas of cast-iron brake shoes manufacturing, because many variables interact with each other simultaneously. Multivariate visualization comes to the fore when researchers have difficulties in comprehending many dimensions at one time. Technological data (hardness and chemical composition) obtained from cast-iron brake shoes were used for this purpose. In order to settle the multiple correlation between the hardness of the cast-iron brake shoes, and the chemical compositions elements several model of regression equation types has been proposed. Because a three-dimensional surface with variables on three axes is a common way to illustrate multivariate data, in which the maximum and minimum values are easily highlighted, we plotted graphical representation of the regression equations in order to explain interaction of the variables and locate the optimal level of each variable for

Barefoot versus shoe running: from the past to the present.

Science.gov (United States)

Kaplan, Yonatan

2014-02-01

Barefoot running is not a new concept, but relatively few people choose to engage in barefoot running on a regular basis. Despite the technological developments in modern running footwear, as many as 79% of runners are injured every year. Although benefits of barefoot running have been proposed, there are also potential risks associated with it. To review the evidence-based literature concerning barefoot/minimal footwear running and the implications for the practicing physician. Multiple publications were reviewed using an electronic search of databases such as Medline, Cinahl, Embase, PubMed, and Cochrane Database from inception until August 30, 2013 using the search terms barefoot running, barefoot running biomechanics, and shoe vs. barefoot running. Ninety-six relevant articles were found. Most were reviews of biomechanical and kinematic studies. There are notable differences in gait and other parameters between barefoot running and shoe running. Based on these findings and much anecdotal evidence, one could conclude that barefoot runners should have fewer injuries, better performance, or both. Several athletic shoe companies have designed running shoes that attempt to mimic the barefoot condition, and thus garner the purported benefits of barefoot running. Although there is no evidence that confirms or refutes improved performance and reduced injuries in barefoot runners, many of the claimed disadvantages to barefoot running are not supported by the literature. Nonetheless, it seems that barefoot running may be an acceptable training method for athletes and coaches, as it may minimize the risks of injury.

The effects of high custom made shoes on gait characteristics and patient satisfaction in hemiplegic gait.

Science.gov (United States)

Eckhardt, Martine M; Mulder, Mascha C Borgerhoff; Horemans, Herwin L; van der Woude, Luc H; Ribbers, Gerard M

2011-10-01

To determine the effects of a temporary high custom made orthopaedic shoe on functional mobility, walking speed, and gait characteristics in hemiplegic stroke patients. In addition, interference of attentional demands and patient satisfaction were studied. Clinical experimental study. University Medical Centre. Nineteen stroke patients (12 males; mean age 55 years (standard deviation (SD) 10 years); mean time post onset 3.6 months (SD 1.4 months)) with a spastic paresis of the lower extremity. Functional mobility was assessed with the timed up and go test, walking speed and gait characteristics were measured with clinical gait analysis and performed with and without a verbal dual task. Patient satisfaction was determined with a questionnaire. Walking with the high orthopaedic shoe resulted in improved functional mobility (22%; pshoes. The dual task interfered with functional mobility during walking. The interference was equally big for normal shoes as for the orthopaedic shoe. Patients evaluated walking with the high orthopaedic shoe as an improvement (psafety, walking distance and walking speed. In the early recovery phase after stroke, when regaining walking ability, a temporary high orthopaedic shoe can improve hemiplegic gait, even with dual task interference. Copyright © 2011 Elsevier B.V. All rights reserved.

The effect of material characteristics of shoe soles on muscle activation and energy aspects during running.

Science.gov (United States)

Nigg, B M; Stefanyshyn, D; Cole, G; Stergiou, P; Miller, J

2003-04-01

The purposes of this study were (a) to determine group and individual differences in oxygen consumption during heel-toe running and (b) to quantify the differences in EMG activity for selected muscle groups of the lower extremities when running in shoes with different mechanical heel characteristics. Twenty male runners performed heel-toe running using two shoe conditions, one with a mainly elastic and a visco-elastic heel. Oxygen consumption was quantified during steady state runs of 6 min duration, running slightly above the aerobic threshold providing four pairs of oxygen consumption results for comparison. Muscle activity was quantified using bipolar surface EMG measurements from the tibialis anterior, medial gastrocnemius, vastus medialis and the hamstrings muscle groups. EMG data were sampled for 5 s every minute for the 6 min providing 30 trials. EMG data were compared for the different conditions using an ANOVA (alpha=0.05). The findings of this study showed that changes in the heel material characteristics of running shoes were associated with (a) subject specific changes in oxygen consumption and (b) subject and muscle specific changes in the intensities of muscle activation before heel strike in the lower extremities. It is suggested that further study of these phenomena will help understand many aspects of human locomotion, including work, performance, fatigue and possible injuries.

Does Shoe Collar Height Influence Ankle Joint Kinematics and Kinetics in Sagittal Plane Maneuvers?

Directory of Open Access Journals (Sweden)

Yang Yang, Ying Fang, Xini Zhang, Junliang He, Weijie Fu

2017-12-01

Full Text Available The Objective of the study is to investigate the effects of basketball shoes with different collar heights on ankle kinematics and kinetics and athletic performance in different sagittal plane maneuvers. Twelve participants who wore high-top and low-top basketball shoes (hereafter, HS and LS, respectively performed a weight-bearing dorsiflexion (WB-DF maneuver, drop jumps (DJs, and lay-up jumps (LJs. Their sagittal plane kinematics and ground reaction forces were recorded using the Vicon motion capture system and Kistler force plates simultaneously. Moreover, ankle dorsiflexion and plantarflexion angles, moment, power, stiffness, and jump height were calculated. In the WB-DF test, the peak ankle dorsiflexion angle (p = 0.041 was significantly smaller in HS than in LS. Additionally, the peak ankle plantarflexion moment (p = 0.028 and power (p = 0.022 were significantly lower in HS than in LS during LJs but not during DJs. In both jumping maneuvers, no significant differences were found in the jump height or ankle kinematics between the two shoe types. According to the WB-DF test, increasing shoe collar height can effectively reduce the ankle range of motion in the sagittal plane. Although the HS did not restrict the flexion–extension performance of the ankle joint during two jumping maneuvers, an increased shoe collar height can reduce peak ankle plantarflexion moment and peak power during the push-off phase in LJs. Therefore, a higher shoe collar height should be used to circumvent effects on the partial kinetics of the ankle joint in the sagittal plane.

Does Shoe Collar Height Influence Ankle Joint Kinematics and Kinetics in Sagittal Plane Maneuvers?

Science.gov (United States)

Yang, Yang; Fang, Ying; Zhang, Xini; He, Junliang; Fu, Weijie

2017-12-01

The Objective of the study is to investigate the effects of basketball shoes with different collar heights on ankle kinematics and kinetics and athletic performance in different sagittal plane maneuvers. Twelve participants who wore high-top and low-top basketball shoes (hereafter, HS and LS, respectively) performed a weight-bearing dorsiflexion (WB-DF) maneuver, drop jumps (DJs), and lay-up jumps (LJs). Their sagittal plane kinematics and ground reaction forces were recorded using the Vicon motion capture system and Kistler force plates simultaneously. Moreover, ankle dorsiflexion and plantarflexion angles, moment, power, stiffness, and jump height were calculated. In the WB-DF test, the peak ankle dorsiflexion angle (p = 0.041) was significantly smaller in HS than in LS. Additionally, the peak ankle plantarflexion moment (p = 0.028) and power (p = 0.022) were significantly lower in HS than in LS during LJs but not during DJs. In both jumping maneuvers, no significant differences were found in the jump height or ankle kinematics between the two shoe types. According to the WB-DF test, increasing shoe collar height can effectively reduce the ankle range of motion in the sagittal plane. Although the HS did not restrict the flexion-extension performance of the ankle joint during two jumping maneuvers, an increased shoe collar height can reduce peak ankle plantarflexion moment and peak power during the push-off phase in LJs. Therefore, a higher shoe collar height should be used to circumvent effects on the partial kinetics of the ankle joint in the sagittal plane.

The Role of Shoe Design in Ankle Sprain Rates Among Collegiate Basketball Players

Science.gov (United States)

Curtis, Claudia K; Laudner, Kevin G; McLoda, Todd A; McCaw, Steven T

2008-01-01

Context: Much of the recent focus in shoe design and engineering has been on improving athletic performance. Currently, this improvement has been in the form of “cushioned column systems,” which are spring-like in design and located under the heel of the shoe in place of a conventional heel counter. Concerns have been raised about whether this design alteration has increased the incidence of ankle sprains. Objective: To examine the incidence of lateral ankle sprains in collegiate basketball players with regard to shoe design. Design: Prospective cohort study. Setting: Certified athletic trainers at 1014 National Collegiate Athletic Association (NCAA)-affiliated schools sponsoring basketball during the 2005–2006 regular season were notified of an online questionnaire. Athletic trainers at 22 of the 1014 schools participated. Patients or Other Participants: A total of 230 basketball players (141 males, 89 females; age  =  20.2 ± 1.5 years) from NCAA Division I–III basketball programs sustained lateral ankle sprains. Main Outcome Measure(s): Ankle sprain information and type of shoe worn (cushioned column or noncushioned column) were collected via online survey. The incidence of lateral ankle sprains and type of shoes worn were compared using a chi-square analysis. Results: No difference was noted in ankle sprain incidence between groups (χ2  =  2.44, P  =  .20, relative risk  =  1.47, 95% confidence interval [CI]  =  0.32, 6.86). The incidence of ankle sprains was 1.33 per 1000 exposures in the cushioned column group (95% CI  =  0.62, 3.51) and 1.96 per 1000 exposures in the noncushioned column group (95% CI  =  0.51, 4.22). Conclusions: No increased incidence of ankle sprains was associated with shoe design. PMID:18523571

Influence of midsole hardness of standard cushioned shoes on running-related injury risk.

Science.gov (United States)

Theisen, Daniel; Malisoux, Laurent; Genin, Joakim; Delattre, Nicolas; Seil, Romain; Urhausen, Axel

2014-03-01

In this double-blind randomised controlled trial, we tested if leisure-time runners using shoes with less compliant midsoles have a higher running-related injury (RRI) risk. We provided 247 runners with standard running shoes having either a soft study shoes (soft-SS) or a hard study shoes (hard-SS) midsole and followed them prospectively for 5 months regarding RRI. All information about sports practice and injuries was uploaded on a dedicated internet platform and checked for consistency and completeness. RRI was defined as any first-time pain sustained during or as a result of running practice and impeding normal running activity for at least 1 day. Cox proportional hazards regressions were used to identify RRI risk factors. The type of study shoes used for running was not associated with RRIs (HR=0.92; 95% CI 0.57 to 1.48). The hard-SS had a 15% greater overall stiffness in the heel region. The two study groups were similar regarding personal and sports participation characteristics, except for years of running experience, which was higher (prunning. No between-group differences were found regarding injury location, type, severity or category. Nevertheless, the adjusted regression model revealed positive associations with RRI risk for body mass index (HR=1.126; 95% CI 1.033 to 1.227), previous injury (HR=1.735; 95% CI 1.037 to 2.902) and mean session intensity (HR=1.396; 95% CI 1.040 to 1.874). Protective factors were previous regular running activity (HR=0.422; 95% CI 0.228 to 0.779) and weekly volume of other sports activities (HR=0.702; 95% CI 0.561 to 0.879). Midsole hardness of modern cushioned running shoes does not seem to influence RRI risk.

[Technical aspects in the provision of orthopedic shoes for athletes].

Science.gov (United States)

Walther, M; Volkering, C; Röser, A

2013-03-01

From the technical point of view different groups must be distinguished in the provision of orthopedic shoes for athletes. The one group encompasses athletes who are provided with insoles in the hope of improved comfort or better performance. The other group includes athletes with diseases or injuries of the lower limbs for whom the provision of appropriate shoes and insoles makes it possible for them to participate again actively in their chosen sport. In such cases one has to differentiate between the purely physical disorder of the foot and biomechanical disorders. For the first group the correct fitting of the shoe is the most important factor whereas in the second group attempts are made to correct and/or compensate for the deficit by means of insoles and wedges as well as supporting or bedding elements. The particular challenge for all such measures is to achieve an as small as possible impairment on the sport activity or, in the ideal cases, even to support it. © Georg Thieme Verlag KG Stuttgart · New York.

Fluctuating survival selection explains variation in avian group size.

Science.gov (United States)

Brown, Charles R; Brown, Mary Bomberger; Roche, Erin A; O'Brien, Valerie A; Page, Catherine E

2016-05-03

Most animal groups vary extensively in size. Because individuals in certain sizes of groups often have higher apparent fitness than those in other groups, why wide group size variation persists in most populations remains unexplained. We used a 30-y mark-recapture study of colonially breeding cliff swallows (Petrochelidon pyrrhonota) to show that the survival advantages of different colony sizes fluctuated among years. Colony size was under both stabilizing and directional selection in different years, and reversals in the sign of directional selection regularly occurred. Directional selection was predicted in part by drought conditions: birds in larger colonies tended to be favored in cooler and wetter years, and birds in smaller colonies in hotter and drier years. Oscillating selection on colony size likely reflected annual differences in food availability and the consequent importance of information transfer, and/or the level of ectoparasitism, with the net benefit of sociality varying under these different conditions. Averaged across years, there was no net directional change in selection on colony size. The wide range in cliff swallow group size is probably maintained by fluctuating survival selection and represents the first case, to our knowledge, in which fitness advantages of different group sizes regularly oscillate over time in a natural vertebrate population.

Measurement of oil film thickness and friction force on a guide shoe bearing

DEFF Research Database (Denmark)

Vølund, Anders

2002-01-01

An experimental program was carried out in order to reveal oil film thickness, and friction force of the guide shoe bearing of a large two stroke marine diesel engine. The experiment was conducted on a full size engine located at the research facility at MAN B&W Diesel A/S. The experiment...... was conducted such that the influence from the experiment on the characteristics were as small as possible. The objective of the experiment was to determine the frictional loss of this bearing and to check whether a suggested numerical model was applicable or not. Some future aspects for this bearing...

The Relationship of Foot Shape and Sensitivity to Comfort of Shoe-Inserts

Science.gov (United States)

1998-07-30

tension of the plantar fascia have been implicated by several authors as a cause of plan tar fasciitis which results in symptomatic heel pain and...Pressure distribution Relationship Between Foot Sensitivity and Plantar Pressure RESULTS AND DISCUSSION The shoe and insert factors Factor Sl...sensitivity of the plantar surface of the foot). For activities which are typical for army personal the choice of an appropriate shoe is essential

Post-marathon wearing of Masai Barefoot Technology shoes facilitates recovery from race-induced fatigue: an evaluation utilizing a visual analog scale

Directory of Open Access Journals (Sweden)

Nakagawa K

2014-12-01

Full Text Available Kento Nakagawa, Takashi Obu, Kazuyuki KanosueFaculty of Sport Sciences, Waseda University, Tokorozawa, Saitama, Japan Purpose: To investigate the potential benefit of post-race wearing of unstable shoes (Masai Barefoot Technology [MBT] on recovery from marathon race–induced fatigue.Patients and methods: Forty-five runners who participated in a full marathon race were divided into three groups: 1 MBT shoes, 2 trail running shoes, and 3 control (CON. Participants ran a full marathon with their own running shoes, and then put on the assigned shoes immediately after the race. They continued to wear the assigned shoes for the ensuing 3 days. The CON group wore their usual shoes. Estimates of post-race fatigue were made by the participants on questionnaires that utilized a visual analog scale. Estimates were made just after the race, as well as for the next 3 days.Results: The subjective fatigue of the MBT group was lower than that of the CON (P<0.05 or trail running shoe groups (P<0.05 on day 3.Conclusion: MBT shoe intervention can promote recovery from the fatigue induced by running a full marathon.Keywords: footwear, VAS, full marathon

VIDEO-ANALYSIS OF THE EFFECT OF DIFFERENT TYPES OF ADAPTED SHOES ON KNEE ADDUCTION MOMENT

Directory of Open Access Journals (Sweden)

Andrey Yu. Aksenov

2017-03-01

Full Text Available Background. The effect of different footwear profiles on knee adduction moment have not been fully studied. Methods. Fifteen healthy volunteer subjects, age 25.3 (±2.73, undertook a series of gait laboratory trials with adapted shoes. Kinematic and kinetic data were collect using 16 Oqus 3+ cameras and the walking speed was controlled using timing gates. High street shoes were adapted to include five different heel heights (varying from a 1.5 cm to 5.5 cm heels, two heel profile conditions (curved and semi-curved heels, three varying apex angles (10, 15, and 20 degrees, and barefoot and 3CR footwear conditions. The baseline shoe had no heel curve, a heel height of 3.5cm, an apex position of 62.5% of the shoe length, an apex angle of 15 deg, and a rigid forepart of the shoe. Results. The shoe with 5.5 cm heel height significantly increased the mean knee adduction moment during 50%–100% of the stance phase compared to the 1.5 cm heel (p = 0.008. The high heel shoe also significantly increased knee adduction impulse (area under the curve versus the 1.5, 2.5, and 3.5 cm heels, and the 10° toe angle and barefoot condition. Ten degrees of toe angle reduced mean knee adduction moment during 0%–50% of the stance phase versus 20° and significantly reduced mean knee adduction moment during the late stance phase versus 15° and 20° toe angle footwear conditions. Walking with the curved heel for the healthy subjects increased mean knee adduction moment during 0%–50% of the stance phase compared to the heel without curvature (p < 0.0009. Conclusion. Further study is required to investigate those changes in patients with high risk of knee osteoarthritis.

Improving Quality of Shoe Soles Product using Six Sigma

Science.gov (United States)

Jesslyn Wijaya, Athalia; Trusaji, Wildan; Akbar, Muhammad; Ma’ruf, Anas; Irianto, Dradjad

2018-03-01

A manufacture in Bandung produce kind of rubber-based product i.e. trim, rice rollers, shoe soles, etc. After penetrating the shoe soles market, the manufacture has met customer with tight quality control. Based on the past data, defect level of this product was 18.08% that caused the manufacture’s loss of time and money. Quality improvement effort was done using six sigma method that included phases of define, measure, analyse, improve, and control (DMAIC). In the design phase, the object’s problem and definition were defined. Delphi method was also used in this phase to identify critical factors. In the measure phase, the existing process stability and sigma quality level were measured. Fishbone diagram and failure mode and effect analysis (FMEA) were used in the next phase to analyse the root cause and determine the priority issues. Improve phase was done by designing alternative improvement strategy using 5W1H method. Some improvement efforts were identified, i.e. (i) modifying design of the hanging rack, (ii) create pantone colour book and check sheet, (iii) provide pedestrian line at compound department, (iv) buying stop watch, and (v) modifying shoe soles dies. Some control strategies for continuous improvement were proposed such as SOP or reward and punishment system.

The Red Shoes : Motion picture (1948)

OpenAIRE

Lauri Lucente, Gloria; Buhagiar, Celaine

2011-01-01

Black Swan : A ballet dancer wins the lead in "Swan Lake" and is perfect for the role of the delicate White Swan - Princess Odette - but slowly loses her mind as she becomes more and more like Odile, the Black Swan. The Red Shoes : A young ballet dancer is torn between the man she loves and her pursuit to become a prima ballerina.

Influence of footwear designed to boost energy return on running economy in comparison to a conventional running shoe.

Science.gov (United States)

Sinclair, J; Mcgrath, R; Brook, O; Taylor, P J; Dillon, S

2016-01-01

Running economy is a reflection of the amount of inspired oxygen required to maintain a given velocity and is considered a determining factor for running performance. Athletic footwear has been advocated as a mechanism by which running economy can be enhanced. New commercially available footwear has been developed in order to increase energy return, although their efficacy has not been investigated. This study aimed to examine the effects of energy return footwear on running economy in relation to conventional running shoes. Twelve male runners completed 6-min steady-state runs in conventional and energy return footwear. Overall, oxygen consumption (VO2), heart rate, respiratory exchange ratio, shoe comfort and rating of perceived exertion were assessed. Moreover, participants subjectively indicated which shoe condition they preferred for running. Differences in shoe comfort and physiological parameters were examined using Wilcoxon signed-rank tests, whilst shoe preferences were tested using a chi-square analysis. The results showed that VO2 and respiratory exchange ratio were significantly lower, and shoe comfort was significantly greater, in the energy return footwear. Given the relationship between running economy and running performance, these observations indicate that the energy return footwear may be associated with enhanced running performance in comparison to conventional shoes.

If the shoe fits: development of an on-line tool to aid practitioner/patient discussions about 'healthy footwear'.

Science.gov (United States)

Farndon, Lisa; Robinson, Victoria; Nicholls, Emily; Vernon, Wesley

2016-01-01

A previous study highlighted the importance of footwear to individuals' sense of their identity, demonstrating that shoes must 'fit' someone socially, as well as functionally. However, unhealthy shoes can have a detrimental effect on both foot health and mobility. This project utilises qualitative social science methods to enable podiatrists to understand the broader contribution of footwear to patients' sense of themselves and from this an online toolkit was developed to aid footwear education. Semi-structured interviews were conducted with six podiatrists/shoe-fitters and 13 people with foot pathologies, some of whom also completed shoe diaries. These were supplemented with some follow-up interviews and photographs of participants' own shoes were taken to allow in-depth discussions. Four areas related to 'fit' were identified; practicalities, personal, purpose and pressures, all of which need to be considered when discussing changes in footwear. These were incorporated into an online toolkit which was further validated by service users and practitioners in a focus group. This toolkit can support podiatrists in partnership with patients to identify and address possible barriers to changing footwear towards a more suitable shoe. Enabling patients to make healthier shoe choices will help contribute to improvements in their foot health and mobility.

The risks and benefits of running barefoot or in minimalist shoes: a systematic review.

Science.gov (United States)

Perkins, Kyle P; Hanney, William J; Rothschild, Carey E

2014-11-01

The popularity of running barefoot or in minimalist shoes has recently increased because of claims of injury prevention, enhanced running efficiency, and improved performance compared with running in shoes. Potential risks and benefits of running barefoot or in minimalist shoes have yet to be clearly defined. To determine the methodological quality and level of evidence pertaining to the risks and benefits of running barefoot or in minimalist shoes. In September 2013, a comprehensive search of the Ovid MEDLINE, SPORTDiscus, and CINAHL databases was performed by 2 independent reviewers. Included articles were obtained from peer-reviewed journals in the English language with no limit for year of publication. Final inclusion criteria required at least 1 of the following outcome variables: pain, injury rate, running economy, joint forces, running velocity, electromyography, muscle performance, or edema. Systematic review. Level 3. Two reviewers appraised each article using the Downs and Black checklist and appraised each for level of evidence. Twenty-three articles met the criteria for this review. Of 27 possible points on the Downs and Black checklist, articles scored between 13 and 19 points, indicating a range of evidence from very limited to moderate. Moderate evidence supports the following biomechanical differences when running barefoot versus in shoes: overall less maximum vertical ground reaction forces, less extension moment and power absorption at the knee, less foot and ankle dorsiflexion at ground contact, less ground contact time, shorter stride length, increased stride frequency, and increased knee flexion at ground contact. Because of lack of high-quality evidence, no definitive conclusions can be drawn regarding specific risks or benefits to running barefoot, shod, or in minimalist shoes.

The effect of shoe design and lateral wedging on knee loading

DEFF Research Database (Denmark)

Mølgaard, Carsten; Kersting, Uwe G.

The increasing number of patients with developing osteoarthritis is accompanied by a growing scientific interest in non-operative early treatment strategies. It is generally believed that laterally wedged insoles can change the distribution of the knee loading, but the importance of footwear design...... shoe were revealed. Conclusion: Lateral wedging is effective regardless of shoe design. Differences between the four neutral walking conditions underline the importance of footwear choice in individuals. It is safe to apply lateral wedges without jeopardizing muscular control during walking regardless...

Occupational skin hazards and prevalence of occupational skin diseases in shoe manufacturing workers in Indonesia

NARCIS (Netherlands)

Febriana, Sri Awalia; Soebono, Hardyanto; Coenraads, Pieter-Jan

Purpose Shoe manufacturing workers are exposed daily to an extensive range of potential physical and chemical occupational hazards. Shoe manufacturing in Indonesia is one of the industrial sectors that has shown sustained growth amongst the newly industrialized countries (NICs). In this study, we

Shoe contact dermatitis from dimethyl fumarate: clinical manifestations, patch test results, chemical analysis, and source of exposure.

Science.gov (United States)

Giménez-Arnau, Ana; Silvestre, Juan Francisco; Mercader, Pedro; De la Cuadra, Jesus; Ballester, Isabel; Gallardo, Fernando; Pujol, Ramón M; Zimerson, Erik; Bruze, Magnus

2009-11-01

The methyl ester form of fumaric acid named dimethyl fumarate (DMF) is an effective mould-growth inhibitor. Its irritating and sensitizing properties were demonstrated in animal models. Recently, DMF has been identified as responsible for furniture contact dermatitis in Europe. To describe the clinical manifestations, patch test results, shoe chemical analysis, and source of exposure to DMF-induced shoe contact dermatitis. Patients with suspected shoe contact dermatitis were studied in compliance with the Declaration of Helsinki. Patch test results obtained with their own shoe and the European baseline series, acrylates and fumaric acid esters (FAE), were recorded according to international guidelines. The content of DMF in shoes was analysed with gas chromatography and mass spectrometry. Acute, immediate irritant contact dermatitis and non-immunological contact urticaria were observed in eight adults and two children, respectively. All the adult patients studied developed a delayed sensitization demonstrated by a positive patch testing to DMF Global preventive measures for avoiding contact with DMF are necessary.

Optimal fit of chairside-fabricated distal shoe space maintainer.

Science.gov (United States)

Nouri, M R; Kennedy, D B

2013-10-01

Premature loss of a primary second molar may lead to space loss in the dental arch. This space loss tends to be more severe in unfavourable malocclusions. The distal shoe space maintainer (DSSM) may be beneficial in controlling the path of eruption of an unerupted permanent first molar from the primary into the early mixed dentition. This article describes the technique for achieving optimal fit of a chairside-fabricated band and DSSM in a single visit by contouring the distal shoe blade, and by extending it to the mesial surface of the permanent first molar. Upon the eruption of the permanent first molar DSSM may be modified to a reverse band-and-loop, or replaced by a lingual holding arch.

The influence of the cast iron structure upon the hardness of brake shoes meant for the rolling sock

International Nuclear Information System (INIS)

Socalici, A; Pascu, L; Popa, E; Hepuţ, T

2015-01-01

An important characteristic with a high impact upon the exploitation durability of the brake shoes is hardness. The paper introduces the influence of the phosphorous cast iron structure upon the hardness of the brake shoes meant for the tractive and trailing rolling stock. The results presented show the variation of hardness on the surface and the cross section of the braking shoe (paper)

The effect of textured ballet shoe insoles on ankle proprioception in dancers.

Science.gov (United States)

Steinberg, Nili; Waddington, Gordon; Adams, Roger; Karin, Janet; Tirosh, Oren

2016-01-01

Impaired ankle inversion movement discrimination (AIMD) can lead to ankle sprain injuries. The aim of this study was to explore whether wearing textured insoles improved AIMD compared with barefoot, ballet shoes and smooth insoles, among dancers. Forty-four adolescent male and female dancers, aged 13-19, from The Australian Ballet School were tested for AIMD while barefoot, wearing ballet shoes, smooth insoles, and textured insoles. No interaction was found between the four different footwear conditions, the two genders, or the two levels of dancers in AIMD (p > .05). An interaction was found between the four different footwear conditions and the three tertiles when tested in ballet shoes (p = .006). Although significant differences were found between the upper tertiles and the lower tertiles when tested with ballet shoes, barefoot and with smooth insoles (p < .001; p < .001; p = .047, respectively), when testing with textured insoles dancers in the lower tertile obtained similar scores to those obtained by dancers in the upper tertile (p = .911). Textured insoles improved the discrimination scores of dancers with low AIMD, suggesting that textured insoles may trigger the cutaneous receptors in the plantar surface, increasing the awareness of ankle positioning, which in turn might decrease the chance of ankle injury. Copyright © 2015 Elsevier Ltd. All rights reserved.

Shoe-Floor Interactions in Human Walking With Slips: Modeling and Experiments.

Science.gov (United States)

Trkov, Mitja; Yi, Jingang; Liu, Tao; Li, Kang

2018-03-01

Shoe-floor interactions play a crucial role in determining the possibility of potential slip and fall during human walking. Biomechanical and tribological parameters influence the friction characteristics between the shoe sole and the floor and the existing work mainly focus on experimental studies. In this paper, we present modeling, analysis, and experiments to understand slip and force distributions between the shoe sole and floor surface during human walking. We present results for both soft and hard sole material. The computational approaches for slip and friction force distributions are presented using a spring-beam networks model. The model predictions match the experimentally observed sole deformations with large soft sole deformation at the beginning and the end stages of the stance, which indicates the increased risk for slip. The experiments confirm that both the previously reported required coefficient of friction (RCOF) and the deformation measurements in this study can be used to predict slip occurrence. Moreover, the deformation and force distribution results reported in this study provide further understanding and knowledge of slip initiation and termination under various biomechanical conditions.

The effect of shoe type on gait in forefoot strike runners during a 50-km run

Directory of Open Access Journals (Sweden)

Mark E. Kasmer

2014-06-01

Conclusion: More runners adopted a more posterior initial contact area after the 50-km run in the traditional shoe type than in the minimalist shoe type. The runners who adopted a more posterior initial contact area were more closely associated with an increased median frequency of the medial gastrocnemius, which suggests there may be a change in motor unit recruitment pattern during long-distance, sustained velocity running. The increased peak pressures observed in the medial forefoot in the minimalist shoe type may predispose to metatarsal stress fractures in the setting of improper training.

Perspective: Size selected clusters for catalysis and electrochemistry

Science.gov (United States)

Halder, Avik; Curtiss, Larry A.; Fortunelli, Alessandro; Vajda, Stefan

2018-03-01

Size-selected clusters containing a handful of atoms may possess noble catalytic properties different from nano-sized or bulk catalysts. Size- and composition-selected clusters can also serve as models of the catalytic active site, where an addition or removal of a single atom can have a dramatic effect on their activity and selectivity. In this perspective, we provide an overview of studies performed under both ultra-high vacuum and realistic reaction conditions aimed at the interrogation, characterization, and understanding of the performance of supported size-selected clusters in heterogeneous and electrochemical reactions, which address the effects of cluster size, cluster composition, cluster-support interactions, and reaction conditions, the key parameters for the understanding and control of catalyst functionality. Computational modeling based on density functional theory sampling of local minima and energy barriers or ab initio molecular dynamics simulations is an integral part of this research by providing fundamental understanding of the catalytic processes at the atomic level, as well as by predicting new materials compositions which can be validated in experiments. Finally, we discuss approaches which aim at the scale up of the production of well-defined clusters for use in real world applications.

Parents: Avoid Kids Foot Problems with the Right Shoes

Science.gov (United States)

... Print | Share Avoid Kids Foot Problems with the Right Shoes Before you head to the store to ... College of Foot and Ankle Surgeons (ACFAS), All Rights Reserved. Privacy Statement | Disclaimer | Terms and Conditions | Site ...

Uniform deposition of size-selected clusters using Lissajous scanning

International Nuclear Information System (INIS)

Beniya, Atsushi; Watanabe, Yoshihide; Hirata, Hirohito

2016-01-01

Size-selected clusters can be deposited on the surface using size-selected cluster ion beams. However, because of the cross-sectional intensity distribution of the ion beam, it is difficult to define the coverage of the deposited clusters. The aggregation probability of the cluster depends on coverage, whereas cluster size on the surface depends on the position, despite the size-selected clusters are deposited. It is crucial, therefore, to deposit clusters uniformly on the surface. In this study, size-selected clusters were deposited uniformly on surfaces by scanning the cluster ions in the form of Lissajous pattern. Two sets of deflector electrodes set in orthogonal directions were placed in front of the sample surface. Triangular waves were applied to the electrodes with an irrational frequency ratio to ensure that the ion trajectory filled the sample surface. The advantages of this method are simplicity and low cost of setup compared with raster scanning method. The authors further investigated CO adsorption on size-selected Pt n (n = 7, 15, 20) clusters uniformly deposited on the Al 2 O 3 /NiAl(110) surface and demonstrated the importance of uniform deposition.

Uniform deposition of size-selected clusters using Lissajous scanning

Energy Technology Data Exchange (ETDEWEB)

Beniya, Atsushi; Watanabe, Yoshihide, E-mail: e0827@mosk.tytlabs.co.jp [Toyota Central R& D Labs., Inc., 41-1 Yokomichi, Nagakute, Aichi 480-1192 (Japan); Hirata, Hirohito [Toyota Motor Corporation, 1200 Mishuku, Susono, Shizuoka 410-1193 (Japan)

2016-05-15

Size-selected clusters can be deposited on the surface using size-selected cluster ion beams. However, because of the cross-sectional intensity distribution of the ion beam, it is difficult to define the coverage of the deposited clusters. The aggregation probability of the cluster depends on coverage, whereas cluster size on the surface depends on the position, despite the size-selected clusters are deposited. It is crucial, therefore, to deposit clusters uniformly on the surface. In this study, size-selected clusters were deposited uniformly on surfaces by scanning the cluster ions in the form of Lissajous pattern. Two sets of deflector electrodes set in orthogonal directions were placed in front of the sample surface. Triangular waves were applied to the electrodes with an irrational frequency ratio to ensure that the ion trajectory filled the sample surface. The advantages of this method are simplicity and low cost of setup compared with raster scanning method. The authors further investigated CO adsorption on size-selected Pt{sub n} (n = 7, 15, 20) clusters uniformly deposited on the Al{sub 2}O{sub 3}/NiAl(110) surface and demonstrated the importance of uniform deposition.

Running with a minimalist shoe increases plantar pressure in the forefoot region of healthy female runners

NARCIS (Netherlands)

Bergstra, S. A.; Kluitenberg, B.; Dekker, R.; Bredeweg, S. W.; Postema, K.; Van den Heuvel, E. R.; Hijmans, J. M.; Sobhani, S.

OBJECTIVES: Minimalist running shoes have been proposed as an alternative to barefoot running. However, several studies have reported cases of forefoot stress fractures after switching from standard to minimalist shoes. Therefore, the aim of the current study was to investigate the differences in

Duration of slip-resistant shoe usage and the rate of slipping in limited-service restaurants: results from a prospective and crossover study.

Science.gov (United States)

Verma, Santosh K; Zhao, Zhe; Courtney, Theodore K; Chang, Wen-Ruey; Lombardi, David A; Huang, Yueng-Hsiang; Brennan, Melanye J; Perry, Melissa J

2014-01-01

Several studies have indicated that slip-resistant shoes may have a positive effect on reducing the risk of slips and falls, a leading cause of injury at work. Few studies, however, have examined how duration of shoe usage affects their slip-resistance properties. This study examined the association between the duration of slip-resistant shoes usage and the self-reported rate of slipping in limited-service restaurant workers. A total of 475 workers from 36 limited-service restaurants in the USA were recruited to participate in a 12-week prospective study of workplace slipping. Of the 475 participants, 83 reported changing to a new pair of shoes at least once during the 12-week follow-up. The results show that slip-resistant shoes worn for less than six months were moderately more effective than those worn for more than six months. Changing to a new pair of shoes among those wearing slip-resistant shoes at baseline was associated with a 55% reduction in the rate of slipping (RR = 0.45, 95% CI = 0.23-0.89). Further research is needed to develop criteria for the replacement of slip-resistant shoes.

Unravelling anisogamy: egg size and ejaculate size mediate selection on morphology in free-swimming sperm.

Science.gov (United States)

Monro, Keyne; Marshall, Dustin J

2016-07-13

Gamete dimorphism (anisogamy) defines the sexes in most multicellular organisms. Theoretical explanations for its maintenance usually emphasize the size-related selection pressures of sperm competition and zygote survival, assuming that fertilization of all eggs precludes selection for phenotypes that enhance fertility. In external fertilizers, however, fertilization is often incomplete due to sperm limitation, and the risk of polyspermy weakens the advantage of high sperm numbers that is predicted to limit sperm size, allowing alternative selection pressures to target free-swimming sperm. We asked whether egg size and ejaculate size mediate selection on the free-swimming sperm of Galeolaria caespitosa, a marine tubeworm with external fertilization, by comparing relationships between sperm morphology and male fertility across manipulations of egg size and sperm density. Our results suggest that selection pressures exerted by these factors may aid the maintenance of anisogamy in external fertilizers by limiting the adaptive value of larger sperm in the absence of competition. In doing so, our study offers a more complete explanation for the stability of anisogamy across the range of sperm environments typical of this mating system and identifies new potential for the sexes to coevolve via mutual selection pressures exerted by gametes at fertilization. © 2016 The Author(s).

Novel In-Shoe Exoskeleton for Offloading of Forefoot Pressure for Individuals With Diabetic Foot Pathology.

Science.gov (United States)

Roser, Mark C; Canavan, Paul K; Najafi, Bijan; Cooper Watchman, Marcy; Vaishnav, Kairavi; Armstrong, David G

2017-09-01

Infected diabetic foot ulcers are the leading cause of lower limb amputation. This study evaluated the ability of in-shoe exoskeletons to redirect forces outside of body and through an exoskeleton as an effective means of offloading plantar pressure, the major contributing factor of ulceration. We compared pressure in the forefoot and hind-foot of participants (n = 5) shod with novel exoskeleton footwear. Plantar pressure readings were taken during a 6-m walk at participant's self-selected speed, and five strides were averaged. Results were taken with Achilles exotendon springs disengaged as a baseline, followed by measurements taken with the springs engaged. When springs were engaged, all participants demonstrated a decrease in forefoot pressure, averaging a 22% reduction ( P exoskeleton solution. Results suggest that when the novel exoskeletons were deployed in footwear and exotendon springs engaged, force was successfully transferred from the lower leg through the exoskeleton-enabled shoe to ground, reducing load on the forefoot. The results need to be confirmed in a larger sample. Another study is warranted to examine the effectiveness of this offloading to prevent diabetic foot ulcer, while minimizing gait alteration in daily physical activities.

Effects of forefoot bending stiffness of badminton shoes on agility, comfort perception and lower leg kinematics during typical badminton movements.

Science.gov (United States)

Park, Sang-Kyoon; Lam, Wing-Kai; Yoon, Sukhoon; Lee, Ki-Kwang; Ryu, Jiseon

2017-09-01

This study investigated whether an increase in the forefoot bending stiffness of a badminton shoe would positively affect agility, comfort and biomechanical variables during badminton-specific movements. Three shoe conditions with identical shoe upper and sole designs with different bending stiffness (Flexible, Regular and Stiff) were used. Elite male badminton players completed an agility test on a standard badminton court involving consecutive lunges in six directions, a comfort test performed by a pair of participants conducting a game-like practice trial and a biomechanics test involving a random assignment of consecutive right forward lunges. No significant differences were found in agility time and biomechanical variables among the three shoes. The players wearing the shoe with a flexible forefoot outsole demonstrated a decreased perception of comfort in the forefoot cushion compared to regular and stiffer conditions during the comfort test (p badminton-specific tasks. It was concluded that an optimisation of forefoot structure and materials in badminton shoes should consider the individual's perception to maximise footwear comfort in performance.

The barefoot debate: can minimalist shoes reduce running-related injuries?

Science.gov (United States)

Rixe, Jeffrey A; Gallo, Robert A; Silvis, Matthew L

2012-01-01

Running has evolved throughout history from a necessary form of locomotion to an athletic and recreational pursuit. During this transition, our barefoot ancestors developed footwear. By the late 1970s, running popularity surged, and footwear manufacturers developed the running shoe. Despite new shoe technology and expert advice, runners still face high injury rates, which have yet to decline. Recently, "minimalist" running, marked by a soft forefoot strike and shorter, quicker strides, has become increasingly popular within the running community. Biomechanical studies have suggested that these features of barefoot-style running may lead to a reduction in injury rates. After conducting more outcomes-based research, minimalist footwear and gait retraining may serve as new methods to reduce injuries within the running population.

A preliminary case study of the effect of shoe-wearing on the biomechanics of a horse’s foot

Directory of Open Access Journals (Sweden)

Olga Panagiotopoulou

2016-07-01

in the shod condition at mid-stance, consistent with the tentative conclusion that a steel shoe might increase mechanical loading. However, because of our limited sample size none of these apparent differences have been tested for statistical significance. Our preliminary study illustrates how the shoe may influence the dynamics and mechanics of a Thoroughbred horse’s forefoot during slow walking, but more research is needed to quantify the effect of the shoe on the equine forefoot during the whole stance phase, at faster speeds/gaits and with more individuals as well as with a similar focus on the hind feet. We anticipate that our preliminary analysis using advanced methodological approaches will pave the way for new directions in research on the form/function relationship of the equine foot, with the ultimate goal to minimise foot injuries and improve animal health and welfare.

Selection dramatically reduces effective population size in HIV-1 infection

Directory of Open Access Journals (Sweden)

Mittler John E

2008-05-01

Full Text Available Abstract Background In HIV-1 evolution, a 100–100,000 fold discrepancy between census size and effective population size (Ne has been noted. Although it is well known that selection can reduce Ne, high in vivo mutation and recombination rates complicate attempts to quantify the effects of selection on HIV-1 effective size. Results We use the inbreeding coefficient and the variance in allele frequency at a linked neutral locus to estimate the reduction in Ne due to selection in the presence of mutation and recombination. With biologically realistic mutation rates, the reduction in Ne due to selection is determined by the strength of selection, i.e., the stronger the selection, the greater the reduction. However, the dependence of Ne on selection can break down if recombination rates are very high (e.g., r ≥ 0.1. With biologically likely recombination rates, our model suggests that recurrent selective sweeps similar to those observed in vivo can reduce within-host HIV-1 effective population sizes by a factor of 300 or more. Conclusion Although other factors, such as unequal viral reproduction rates and limited migration between tissue compartments contribute to reductions in Ne, our model suggests that recurrent selection plays a significant role in reducing HIV-1 effective population sizes in vivo.

Effect of hoof boots and toe-extension shoes on the forelimb kinetics of horses during walking.

Science.gov (United States)

Amitrano, Fernando N; Gutierrez-Nibeyro, Santiago D; Schaeffer, David J

2016-05-01

OBJECTIVE To determine and compare the effect of hoof boots (HBs) and shoes with a toe extension on stance duration, ground reaction force, and sole length in contact with the ground in nonlame horses during walking. ANIMALS 6 nonlame Standardbreds. PROCEDURES Force plate gait analyses of the forelimbs were performed while the horses were walking barefoot before manipulation of feet (baseline), while the horses were walking fitted with HBs, while the horses were walking shod with toe-extension shoes, and while the horses were walking barefoot after shoe removal. Horses underwent radiography of both forelimb feet to determine the sole length in contact with the ground when barefoot, wearing HBs, and shod with toe-extension shoes. Stance duration, ground reaction force, and sole length were compared among the various walking sessions. RESULTS Compared with baseline findings, stance duration increased significantly when horses were fitted with HBs (7%) or toe-extension shoes (5%). Peak forelimb ground reaction force was similar among walking sessions; however, time of braking force peak was significantly greater during the stance phase only when horses wore HBs. Also, the sole length in contact with the ground was significantly longer in horses fitted with HBs (14.3 cm) or shod with the toe-extension shoes (17.6 cm), compared with that for one of the barefoot hooves (12.7 cm). CONCLUSIONS AND CLINICAL RELEVANCE In nonlame horses, use of HBs prolonged the stance time and time of braking force peak, which is indicative of a slower deceleration phase during limb impact with the ground. Also, the use of HBs prolonged the deceleration phase of the stride and increased the sole length in contact with the ground.

Adolescent runners: the effect of training shoes on running kinematics.

Science.gov (United States)

Mullen, Scott; Toby, E Bruce

2013-06-01

The modern running shoe typically features a large cushioned heel intended to dissipate the energy at heel strike to the knees and hips. The purpose of this study was to evaluate the effect that shoes have upon the running biomechanics among competitive adolescent runners. We wish to answer the question of whether running style is altered in these athletes because of footwear. Twelve competitive adolescent athletes were recruited from local track teams. Each ran on a treadmill in large heel trainers, track flats, and barefoot. Four different speeds were used to test each athlete. The biomechanics were assessed with a motion capture system. Stride length, heel height during posterior swing phase, and foot/ground contact were recorded. Shoe type markedly altered the running biomechanics. The foot/ground contact point showed differences in terms of footwear (Ptrainers, the athletes landed on their heels 69.79% of the time at all speeds (Ptrainers promote a heel strike pattern, whereas track flats and barefoot promote a forefoot or midfoot strike pattern. Training in heavily cushioned trainers by the competitive runner has not been clearly shown to be detrimental to performance, but it does change the gait pattern. It is not known whether the altered biomechanics of the heavily heeled cushioned trainer may be detrimental to the adolescent runner who is still developing a running style.

Shoe sole tread designs and outcomes of slipping and falling on slippery floor surfaces.

Directory of Open Access Journals (Sweden)

Li-Wen Liu

Full Text Available A gait experiment was conducted under two shoe sole and three floor conditions. The shoe soles and floors were characterized by the tread and groove designs on the surface. The coefficients of friction (COF on the floor in the target area were measured. The subjects were required to walk on a walkway and stepping on a target area covered with glycerol. The motions of the feet of the subjects were captured. Gait parameters were calculated based on the motion data. Among the 240 trials, there were 37 no-slips, 81 microslips, 45 slides, and 77 slips. It was found that the condition with shoe sole and floor had both tread grooves perpendicular to the walking direction had the highest COF, the shortest slip distance, and the lowest percentages of slide and slip. The condition with shoe sole and floor had both tread grooves parallel to the walking direction had the lowest COF and the longest slip distance among all experimental conditions. The Pearson's correlation coefficients between slip distance and slip velocity, time to foot flat, foot angle, and compensatory step length were 0.82 (p<0.0001, 0.33 (p<0.0001, -0.54 (p<0.0001, and -0.51 (p<0.0001, respectively.

Fluid Pressures at the Shoe-Floor-Contaminant Interface During Slips: Effects of Tread & Implications on Slip Severity

Science.gov (United States)

Beschorner, Kurt E.; Albert, Devon L.; Chambers, April J.; Redfern, Mark S.

2018-01-01

Previous research on slip and fall accidents has suggested that pressurized fluid between the shoe and floor is responsible for initiating slips yet this effect has not been verified experimentally. This study aimed to 1) measure hydrodynamic pressures during slipping for treaded and untreaded conditions; 2) determine the effects of fluid pressure on slip severity; and 3) quantify how fluid pressures vary with instantaneous resultant slipping speed, position on the shoe surface, and throughout the progression of the slip. Eighteen subjects walked on known dry and unexpected slippery floors, while wearing treaded and untreaded shoes. Fluid pressure sensors, embedded in the floor, recorded hydrodynamic pressures during slipping. The maximum fluid pressures (mean+/−standard deviation) were significantly higher for the untreaded conditions (124 +/−75 kPa) than the treaded conditions (1.1 +/−0.29 kPa). Maximum fluid pressures were positively correlated with peak slipping speed (r = 0.87), suggesting that higher fluid pressures, which are associated with untreaded conditions, resulted in more severe slips. Instantaneous resultant slipping speed and position of sensor relative to the shoe sole and walking direction explained 41% of the fluid pressure variability. Fluid pressures were primarily observed for untreaded conditions. This study confirms that fluid pressures are relevant to slipping events, consistent with fluid dynamics theory (i.e. the Reynolds equation), and can be modified with shoe tread design. The results suggest that the occurrence and severity of unexpected slips can be reduced by designing shoes/floors that reduce underfoot fluid pressures. PMID:24267270

The bending stiffness of shoes is beneficial to running energetics if it does not disturb the natural MTP joint flexion.

Science.gov (United States)

Oh, Keonyoung; Park, Sukyung

2017-02-28

A local minimum for running energetics has been reported for a specific bending stiffness, implying that shoe stiffness assists in running propulsion. However, the determinant of the metabolic optimum remains unknown. Highly stiff shoes significantly increase the moment arm of the ground reaction force (GRF) and reduce the leverage effect of joint torque at ground push-off. Inspired by previous findings, we hypothesized that the restriction of the natural metatarsophalangeal (MTP) flexion caused by stiffened shoes and the corresponding joint torque changes may reduce the benefit of shoe bending stiffness to running energetics. We proposed the critical stiffness, k cr , which is defined as the ratio of the MTP joint (MTPJ) torque to the maximal MTPJ flexion angle, as a possible threshold of the elastic benefit of shoe stiffness. 19 subjects participated in a running test while wearing insoles with five different bending stiffness levels. Joint angles, GRFs, and metabolic costs were measured and analyzed as functions of the shoe stiffness. No significant changes were found in the take-off velocity of the center of mass (CoM), but the horizontal ground push-offs were significantly reduced at different shoe stiffness levels, indicating that complementary changes in the lower-limb joint torques were introduced to maintain steady running. Slight increases in the ankle, knee, and hip joint angular impulses were observed at stiffness levels exceeding the critical stiffness, whereas the angular impulse at the MTPJ was significantly reduced. These results indicate that the shoe bending stiffness is beneficial to running energetics if it does not disturb the natural MTPJ flexion. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Effect of Advertising, Perceived Quality and Brand Awareness on Consumer Purchase Intention (Case Study: Adidas Sport Shoes)

OpenAIRE

Laluyan, Wanda Nadya; Pangemanan, Sifrid S; Worang, Frederik G

2017-01-01

Sports as needs, which is read by the companies manufacturers who produce a sport shoes product. In Indonesia, the competition in footwear industry is getting tight and variety. It makes so much many shoes retail opened and developing. With that situation, the companies are trying to create a variety shoes and trying to adding new value on their product to keep their customer and getting new consumers and of course to make them still survive in the market. The aims of this study are to analyz...

[Analysis of the protective effect of shock-absorbing shoes for patients treated with hip and knee endoprostheses].

Science.gov (United States)

Gebauer, D; Cziuk, N

1988-01-01

Biomechanical loading of total knee and hip replacement is one of the essential factors which limit the longterm-function of the implant components. A simple and cheap safety provision to avoid mechanical overload seems to be wearing of shock-absorbing shoes. The performed study analyzes the effect of that type of shoe. For judgement the parameters: energy absorption while slow shock, damping while hard shock and safety against sliding were taken. The experiments showed the shock-absorbing shoe is an easy, inexpensive, but very efficient protection measure to improve the longterm-stability of endoprosthesis of the lower extremity.

Identification of fungi from children's shoes and application of a ...

African Journals Online (AJOL)

Jane

2011-10-24

Oct 24, 2011 ... ... for Clean Technology of Leather Manufacture, Institute of Life Sciences, Sichuan ... treated insole against yeasts and molds from children's shoes were evaluated by the ... was produced by a conventional process in factory.

The long-term effect of minimalist shoes on running performance and injury: design of a randomised controlled trial

Science.gov (United States)

Fuller, Joel T; Thewlis, Dominic; Tsiros, Margarita D; Brown, Nicholas A T; Buckley, Jonathan D

2015-01-01

Introduction The outcome of the effects of transitioning to minimalist running shoes is a topic of interest for runners and scientists. However, few studies have investigated the longer term effects of running in minimalist shoes. The purpose of this randomised controlled trial (RCT) is to investigate the effects of a 26 week transition to minimalist shoes on running performance and injury risk in trained runners unaccustomed to minimalist footwear. Methods and analysis A randomised parallel intervention design will be used. Seventy-six trained male runners will be recruited. To be eligible, runners must be aged 18–40 years, run with a habitual rearfoot footfall pattern, train with conventional shoes and have no prior experience with minimalist shoes. Runners will complete a standardised transition to either minimalist or control shoes and undergo assessments at baseline, 6 and 26 weeks. 5 km time-trial performance (5TT), running economy, running biomechanics, triceps surae muscle strength and lower limb bone mineral density will be assessed at each time point. Pain and injury will be recorded weekly. Training will be standardised during the first 6 weeks. Primary statistical analysis will compare 5TT between shoe groups at the 6-week time point and injury incidence across the entire 26-week study period. Ethics and dissemination This RCT has been approved by the Human Research Ethics Committee of the University of South Australia. Participants will be required to provide their written informed consent prior to participation in the study. Study findings will be disseminated in the form of journal publications and conference presentations after completion of planned data analysis. Trial registration number This RCT has been registered with the Australian New Zealand Clinical Trials Registry (ACTRN12613000642785). PMID:26297368

Leukaemia incidence among workers in the shoe and boot manufacturing industry: a case-control study

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Forand Steven P

2004-08-01

Full Text Available Abstract Background Previous reports have indicated an excess of leukaemia in Broome County, New York, particularly in the Town of Union. Surveillance of cancer incidence data indicates that a large proportion of these cases occurred among males ages 65 and older. Shoe and boot manufacturing has been the largest single industry in this area throughout much of the past century. Occupational studies from Europe suggest a link between leukaemia and employment in the shoe and boot manufacturing industry. However, researchers have not found a positive association between leukaemia and employment in the shoe industry among workers in the United States. Methods A matched case-control study was conducted to investigate the association between leukaemia incidence among males 65 and older and employment in the shoe and boot manufacturing industry. Thirty-six cases of leukaemia occurring between 1981–1990; among males age 65 and older; residing in the town of Union met the study case criteria. Death certificates were obtained for each of the cases. These were matched to death certificates of 144 controls on date of death and date of birth +/- 1 year. Death certificates were then examined to determine the employer and occupation of each study subject. Conditional logistic regression was used to determine the risk of leukaemia among those working in the industry. Results The risk of both leukaemia (OR = 1.47; 95% CI 0.70, 3.09 and acute myeloid leukaemia (OR = 1.19; 95% CI 0.33, 4.28 were elevated among those employed in the shoe and boot manufacturing industry, however neither was statistically significant. Conclusion The results, though suggestive of an association between leukaemia and employment in the shoe and boot manufacturing industry, were not statistically conclusive due mainly to limited study power. Several additional limitations may also have prevented the observance of more conclusive findings. Better exposure assessment, information on

Equal Susceptibility and Size-selective Mobility in Aeolian Saltation

Science.gov (United States)

Martin, R. L.; Kok, J. F.

2017-12-01

Natural wind-eroded soils generally contain a mixture of particle sizes. However, models for aeolian saltation are typically derived for sediment bed surfaces containing only a single particle size. To treat natural mixed beds, models for saltation and associated dust aerosol emission have typically simplified aeolian transport either as a series of non-interacting single particle size beds or as a bed containing only the median or mean particle size. Here, we test these common assumptions underpinning aeolian transport models using measurements of size-resolved saltation fluxes at three natural field sites. We find that a wide range of sand size classes experience "equal susceptibility" to saltation at a single common threshold wind shear stress, contrary to the "selective susceptibility" expected for treatment of a mixed bed as multiple single particle size beds. Furthermore, we observe strong size-selectivity in the mobility of different particle sizes, which is not adequately accounted for in current models. At all field sites, mobility is enhanced for particles that are 0.4-0.8 times the median bed particle diameter, while mobility declines rapidly with increasing particle size above this range. We further observe that the most mobile particles also experience the largest saltation heights, which helps to explain variations in size-selective mobility. These observations refute the common simplification of saltation as a series of non-interacting single particle sizes. Sand transport and dust emission models that use this incorrect assumption can be both simplified and improved by instead using a single particle size representative of the mixed bed.

AHP-Based Optimal Selection of Garment Sizes for Online Shopping

Institute of Scientific and Technical Information of China (English)

无

2007-01-01

Garment online shopping has been accepted by more and more consumers in recent years. In online shopping, a buyer only chooses the garment size judged by his own experience without trying-on, so the selected garment may not be the fittest one for the buyer due to the variety of body's figures. Thus, we propose a method of optimal selection of garment sizes for online shopping based on Analytic Hierarchy Process (AHP). The hierarchical structure model for optimal selection of garment sizes is structured and the fittest garment for a buyer is found by calculating the matching degrees between individual's measurements and the corresponding key-part values of ready-to-wear clothing sizes. In order to demonstrate its feasibility, we provide an example of selecting the fittest sizes of men's bottom. The result shows that the proposed method is useful in online clothing sales application.

Experimental Study of Heat Dissipation in Indoor Sports Shoes

NARCIS (Netherlands)

Dessing, O.; Jansen, A.J.; Leihitu, C.; Overhage, D.

2014-01-01

As indoor sports shoes are intensively used in a warm and sweaty environment for periods of up to three consecutive hours, the built-up heat inside is insufficiently released causing warm and perspiring feet. This results in an increased chance of blisters and skin irritations. Experimental research

Concerns and Intentions among Young Migrants in the Shoe-shine ...

African Journals Online (AJOL)

In Ghana, the shoe-shine business is one of the informal sector businesses that ... and methods, results and discussion, conclusions and recommendations. .... that in both Kumasi and Accra, some female migrants are engaged in the kaya yei.

EFFECTS OF UNSTABLE SHOES ON ENERGY COST DURING TREADMILL WALKING AT VARIOUS SPEEDS

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Keiji Koyama

2012-12-01

Full Text Available In recent years, shoes having rounded soles in the anterior- posterior direction have been commercially introduced, which are commonly known as unstable shoes (US. However, physiological responses during walking in US, particularly at various speeds, have not been extensively studied to date. The purpose of this study was to investigate the effect of wearing unstable shoes while walking at low to high speeds on the rate of perceived exertion (RPE, muscle activation, oxygen consumption (VO2, and optimum speed. Healthy male adults wore US or normal walking shoes (WS, and walked at various speeds on a treadmill with no inclination. In experiment 1, subjects walked at 3, 4, 5, 6, and 7 km·h-1 (duration, 3 min for all speeds and were recorded on video from the right sagittal plane to calculate the step length and cadence. Simultaneously, electromyogram (EMG was recorded from six different thigh and calf muscles, and the integrated EMG (iEMG was calculated. In experiment 2, RPE, heart rate and VO2 were measured with the walking speed being increased from 3.6 to 7.2 km·h-1 incrementally by 0.9 km·h-1 every 6 min. The optimum speed, defined by the least oxygen cost, was calculated from the fitted quadratic relationship between walking speed and oxygen cost. Wearing US resulted in significantly longer step length and lower cadence compared with WS condition at any given speed. For all speeds, iEMG in the medial gastrocnemius and soleus muscles, heart rate, and VO2 were significantly higher in US than WS. However, RPE and optimum speed (US, 4.75 ± 0.32 km·h-1; WS, 4. 79 ± 0.18 km·h-1 did not differ significantly between the two conditions. These results suggest that unstable shoes can increase muscle activity of lower legs and energy cost without influencing RPE and optimum speed during walking at various speeds

Effects of unstable shoes on chronic low back pain in health professionals: a randomized controlled trial.

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Armand, Stéphane; Tavcar, Ziva; Turcot, Katia; Allet, Lara; Hoffmeyer, Pierre; Genevay, Stéphane

2014-12-01

The aim of this study was to evaluate the effectiveness of unstable shoes in reducing low back pain in health professionals. Of a volunteer sample of 144 participants, 40 with nonspecific chronic low back pain were eligible and enrolled in this study. Participants were randomized to an intervention group, who wore unstable shoes (model MBT Fora), or a control group, who wore conventional sports shoes (model Adidas Bigroar). The participants had to wear the study shoes during their work hours, and at least 6 hours per workday, over a period of 6 weeks. The primary outcome was low back pain assessed on a Visual Analog Scale. The secondary outcomes were patient satisfaction, disability evaluated using Roland-Morris questionnaire and quality of life evaluated using EQ-VAS. The intervention group showed a significant decrease in pain scores compared to the control group. The rate of satisfaction was higher in the intervention group (79%) compared to the control group (25%). There was no significant difference for the Roland-Morris disability questionnaire score and the EQ-VAS scale. The results of this clinical trial suggest that wearing unstable shoes for 6 weeks significantly decreases low back pain in patients suffering from chronic low back pain but had no significant effect on quality of life and disability scores. Copyright © 2014 Société française de rhumatologie. Published by Elsevier SAS. All rights reserved.

Epidemiology of Shoe Wearing Patterns Over Time in Older Women: Associations With Foot Pain and Hallux Valgus.

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Menz, Hylton B; Roddy, Edward; Marshall, Michelle; Thomas, Martin J; Rathod, Trishna; Peat, George M; Croft, Peter R

2016-12-01

Foot problems are prevalent in older women and are thought to be associated with footwear. This study examined women's shoe wearing patterns over time and evaluated associations between footwear characteristics and foot pain and hallux valgus. Women aged 50-89 years (n = 2,627) completed a survey that included drawings of four toe-box shapes and four heel heights. For each life decade, participants indicated which footwear style they wore most of the time. Foot pain in the past 12 months and hallux valgus were documented by self-report. Logistic regression examined associations between heel height, toe-box shape, foot pain and hallux valgus. Wearing shoes with a high heel and very narrow toe box between the ages of 20 and 29 was common, but decreased to less than 10% by the age of 40. Compared with women who had worn shoes with a very wide toe box, the likelihood of hallux valgus increased in those who had worn shoes with a wide (odds ratio [OR] 1.96, 95% CI 1.03-3.71), narrow (2.39, 1.29-4.42) and very narrow (2.70, 1.46-5.00) toe box between the ages of 20 and 29 and those who wore shoes with a very narrow toe box (1.93, 1.10-3.39) between the ages of 30 and 39. Women wear shoes with a lower heel and broader toe box as they age. Wearing constrictive footwear between the ages of 20 and 39 may be critical for developing hallux valgus in later life. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America.

Effect of Product Quality, Promotion, and Brand Image on Purchase Decision of Nike Sports Shoes (Case Study on S1 Fisip Undip Students)

OpenAIRE

Saputra, Denny; Waluyo, Handoyo Djoko; Listyorini, Sari

2014-01-01

Complex consumer needs all critical and followed increasingly competitive market competition lead to Nike Sports Shoes must to compete and also maintain their market consumer seized from its competitors. Consumers who take the decision to choose Nike Sports Shoes will consider various things before buying it. Consideration to make a decision consist of influenced the quality of the product, promotion, and brand image of Nike Sport Shoes. The problem in this research is Sports Shoes Nike fluct...

Blocked Randomization with Randomly Selected Block Sizes

Directory of Open Access Journals (Sweden)

Jimmy Efird

2010-12-01

Full Text Available When planning a randomized clinical trial, careful consideration must be given to how participants are selected for various arms of a study. Selection and accidental bias may occur when participants are not assigned to study groups with equal probability. A simple random allocation scheme is a process by which each participant has equal likelihood of being assigned to treatment versus referent groups. However, by chance an unequal number of individuals may be assigned to each arm of the study and thus decrease the power to detect statistically significant differences between groups. Block randomization is a commonly used technique in clinical trial design to reduce bias and achieve balance in the allocation of participants to treatment arms, especially when the sample size is small. This method increases the probability that each arm will contain an equal number of individuals by sequencing participant assignments by block. Yet still, the allocation process may be predictable, for example, when the investigator is not blind and the block size is fixed. This paper provides an overview of blocked randomization and illustrates how to avoid selection bias by using random block sizes.

Portion distortion: typical portion sizes selected by young adults.

Science.gov (United States)

Schwartz, Jaime; Byrd-Bredbenner, Carol

2006-09-01

The incidence of obesity has increased in parallel with increasing portion sizes of individually packaged and ready-to-eat prepared foods as well as foods served at restaurants. Portion distortion (perceiving large portion sizes as appropriate amounts to eat at a single eating occasion) may contribute to increasing energy intakes and expanding waistlines. The purpose of this study was to determine typical portion sizes that young adults select, how typical portion sizes compare with reference portion sizes (based in this study on the Nutrition Labeling and Education Act's quantities of food customarily eaten per eating occasion), and whether the size of typical portions has changed over time. Young adults (n=177, 75% female, age range 16 to 26 years) at a major northeastern university. Participants served themselves typical portion sizes of eight foods at breakfast (n=63) or six foods at lunch or dinner (n=62, n=52, respectively). Typical portion-size selections were unobtrusively weighed. A unit score was calculated by awarding 1 point for each food with a typical portion size that was within 25% larger or smaller than the reference portion; larger or smaller portions were given 0 points. Thus, each participant's unit score could range from 0 to 8 at breakfast or 0 to 6 at lunch and dinner. Analysis of variance or t tests were used to determine whether typical and reference portion sizes differed, and whether typical portion sizes changed over time. Mean unit scores (+/-standard deviation) were 3.63+/-1.27 and 1.89+/-1.14, for breakfast and lunch/dinner, respectively, indicating little agreement between typical and reference portion sizes. Typical portions sizes in this study tended to be significantly different from those selected by young adults in a similar study conducted 2 decades ago. Portion distortion seems to affect the portion sizes selected by young adults for some foods. This phenomenon has the potential to hinder weight loss, weight maintenance, and

One size fits all electronics for insole-based activity monitoring.

Science.gov (United States)

Hegde, Nagaraj; Bries, Matthew; Melanson, Edward; Sazonov, Edward

2017-07-01

Footwear based wearable sensors are becoming prominent in many areas of monitoring health and wellness, such as gait and activity monitoring. In our previous research we introduced an insole based wearable system SmartStep, which is completely integrated in a socially acceptable package. From a manufacturing perspective, SmartStep's electronics had to be custom made for each shoe size, greatly complicating the manufacturing process. In this work we explore the possibility of making a universal electronics platform for SmartStep - SmartStep 3.0, which can be used in the most common insole sizes without modifications. A pilot human subject experiments were run to compare the accuracy between the one-size fits all (SmartStep 3.0) and custom size SmartStep 2.0. A total of ~10 hours of data was collected in the pilot study involving three participants performing different activities of daily living while wearing SmartStep 2.0 and SmartStep 3.0. Leave one out cross validation resulted in a 98.5% average accuracy from SmartStep 2.0, while SmartStep 3.0 resulted in 98.3% accuracy, suggesting that the SmartStep 3.0 can be as accurate as SmartStep 2.0, while fitting most common shoe sizes.

Corrective shoeing in horses: analysis of the adaptation period to the new condition imposed

Directory of Open Access Journals (Sweden)

Raquel M. Albernaz

2012-10-01

Full Text Available Corrective shoeing is a method commonly used to alter the locomotion pattern in animals or as therapy for various disorders of the locomotive system of horses. However, to date, there have been no scientific studies discussing the period during which animals adapt to this type of intervention. The goal of this study was to evaluate the horseshoe adaptation period with the toe or heel elevated by six degrees at 0, 48, and 96 hours after each type of shoeing. For this analysis, the horses were recorded while walking on a treadmill. Stride length and gait qualitative analyzes were performed using Dvideow software. The level of significance adopted was 5%. In the present study, there was no significant difference between the evaluation times; elevating the toe or heel by six degrees do not generates discomfort during locomotion, therefore, horses are able to return to a regular exercise or training routine immediately after shoeing.

Adaptation of running pattern to the drop of standard cushioned shoes: A randomised controlled trial with a 6-month follow-up.

Science.gov (United States)

Malisoux, Laurent; Gette, Paul; Chambon, Nicolas; Urhausen, Axel; Theisen, Daniel

2017-08-01

While several cross-sectional studies have investigated the acute effects of shoe drop on running biomechanics, the long-term consequences are currently unknown. This study aimed to investigate if the drop of standard cushioned shoes induces specific adaptations in running technique over a six-month period in leisure-time runners. Double-blinded randomised controlled trial. The participants (n=59) received a pair of shoes with a heel-to-toe drop of 10mm (D10), 6mm (D6) or 0mm (D0) and were followed-up regarding running training over 6 months or 500km, whichever came first. Spatio-temporal variables and kinematics (foot/ground, ankle and knee joint angles) were investigated while running at preferred speed on a treadmill before and after the follow-up. The participants ran 332±178km in the study shoes between pre- and post-tests. There was no shoe version by time interaction for any of the spatio-temporal variables nor for lower limb angles at initial ground contact. A small but significant shoe drop effect was found for knee abduction at mid-stance (p=0.032), as it decreased for the D0 version (-0.3±3.1 vs. -1.3±2.6°) while it increased for the D6 (0.3±2.7 vs. 1.3±3.1°) and D10 version (-0.2±3.2 vs. 0.5±3.1°). However, none of the pairwise comparisons was significant in the post-hoc analysis. Apart from knee abduction at mid-stance, no specific adaptation in spatio-temporal variables and kinematics was found between the three shoe versions during this 6-month follow-up. Thus, shoe drop of standard cushioned shoes does not seem to influence running biomechanics in the long term. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Correlation Of An E-Nose System For Odor Assessment Of Shoe/Sock Systems With A Human Sensory Panel

International Nuclear Information System (INIS)

Horras, Stephan; Reimann, Peter; Schuetze, Andreas; Gaiotto, Alessandra; Mayer, Maria

2009-01-01

Evaluation of strength and quality of smell is today still primarily done with human sensory panels. For a range of applications, technical systems for an objective smell assessment would provide a great benefit in R and D and also day-to-day application. The project presented here specifically addresses the problem of assessing the strength and unpleasantness of smell caused by sweat in shoes and socks by an E-nose system. The ultimate goal is to provide a tool for developing improved shoe/sock systems with optimized materials.The main approach to achieve this goal is to find a correlation between the assessment of a human sensory panel and the complex sensor response patterns of an E-Nose system to appraise the smell of sweat in shoes and socks. Therefore a range of test persons wear shoes and socks under defined ambient conditions in a controlled test environment as well as during everyday use. Afterwards the smell of the shoes and socks is both measured with the E-Nose system and assessed by a human sensory panel. We report here the results of the first larger test series and the identified correlation between the E-Nose system and the human assessment of the smell of sweat.

The Effect of Body Mass on the Shoe-Athlete Interaction.

Science.gov (United States)

Tsouknidas, A; Pantazopoulos, M; Sagris, D; Fasnakis, D; Maropoulos, S; Arabatzi, F; Michailidis, N

2017-01-01

Long-distance running is known to induce joint overloading and elevate cytokine levels, which are the hallmarks for a variety of running-related injuries. To address this, footwear systems incorporate cushioning midsoles to mitigate injurious mechanical loading. The aim of this study was to evaluate the effect of athlete body mass on the cushioning capacity of technical footwear. An artificial heel was prototyped to fit the impact pattern of a heel-strike runner and used to measure shock attenuation by an automated drop test. Impact mass and velocity were modulated to simulate runners of various body mass and speeds. The investigation provided refined insight on running-induced impact transmission to the human body. The examined midsole system was optimized around anthropometric data corresponding to an average (normal) body mass. The results suggest that although modern footwear is capable of attenuating the shock waves occurring during foot strike, improper shoe selection could expose an athlete to high levels of peak stress that could provoke an abnormal cartilage response. The selection of a weight-specific cushioning system could provide optimum protection and could thus prolong the duration of physical exercise beneficial to maintaining a simulated immune system.

The Effect of Body Mass on the Shoe-Athlete Interaction

Directory of Open Access Journals (Sweden)

A. Tsouknidas

2017-01-01

Full Text Available Long-distance running is known to induce joint overloading and elevate cytokine levels, which are the hallmarks for a variety of running-related injuries. To address this, footwear systems incorporate cushioning midsoles to mitigate injurious mechanical loading. The aim of this study was to evaluate the effect of athlete body mass on the cushioning capacity of technical footwear. An artificial heel was prototyped to fit the impact pattern of a heel-strike runner and used to measure shock attenuation by an automated drop test. Impact mass and velocity were modulated to simulate runners of various body mass and speeds. The investigation provided refined insight on running-induced impact transmission to the human body. The examined midsole system was optimized around anthropometric data corresponding to an average (normal body mass. The results suggest that although modern footwear is capable of attenuating the shock waves occurring during foot strike, improper shoe selection could expose an athlete to high levels of peak stress that could provoke an abnormal cartilage response. The selection of a weight-specific cushioning system could provide optimum protection and could thus prolong the duration of physical exercise beneficial to maintaining a simulated immune system.

Shoe drop reduction influences the lower limb biomechanics of children tennis players during an open stance forehand: A longitudinal study.

Science.gov (United States)

Herbaut, Alexis; Simoneau-Buessinger, Emilie; Barbier, Franck; Gillet, Christophe; Roux, Maxime; Guéguen, Nils; Chavet, Pascale

2017-11-01

Compared to traditional tennis shoes, using 0-drop shoes was shown to induce an immediate switch from rear- to forefoot strike pattern to perform an open stance tennis forehand for 30% of children tennis players. The purpose of the study was to examine the long-term effects of a gradual reduction in the shoe drop on the biomechanics of children tennis players performing open stance forehands. Thirty children tennis players participated in 2 laboratory biomechanical test sessions (intermediate: +4 months and final: +8 months) after an inclusion visit where they were randomly assigned to control (CON) or experimental (EXP) group. CON received 12-mm-drop shoes twice, whereas EXP received 8 mm then 4-mm-drop shoes. Strike index indicated that all CON were rearfoot strikers in intermediate and final test sessions. All EXP were rearfoot strikers in intermediate test session, but half the group switched towards a forefoot strike pattern in final test session. This switch resulted in a decreased loading rate of the ground reaction force (-73%, p = .005) but increased peak ankle plantarflexors moment (+47%, p = .050) and peak ankle power absorption (+107%, p = .005) for these participants compared with CON. Biomechanical changes associated with the long-term use of partial minimalist shoes suggest a reduction in heel compressive forces but an increase in Achilles tendon tensile forces.

Persistent directional selection on body size and a resolution to the paradox of stasis.

Science.gov (United States)

Rollinson, Njal; Rowe, Locke

2015-09-01

Directional selection on size is common but often fails to result in microevolution in the wild. Similarly, macroevolutionary rates in size are low relative to the observed strength of selection in nature. We show that many estimates of selection on size have been measured on juveniles, not adults. Further, parents influence juvenile size by adjusting investment per offspring. In light of these observations, we help resolve this paradox by suggesting that the observed upward selection on size is balanced by selection against investment per offspring, resulting in little or no net selection gradient on size. We find that trade-offs between fecundity and juvenile size are common, consistent with the notion of selection against investment per offspring. We also find that median directional selection on size is positive for juveniles but no net directional selection exists for adult size. This is expected because parent-offspring conflict exists over size, and juvenile size is more strongly affected by investment per offspring than adult size. These findings provide qualitative support for the hypothesis that upward selection on size is balanced by selection against investment per offspring, where parent-offspring conflict over size is embodied in the opposing signs of the two selection gradients. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.

A Portable Ultrasonic Nondestructive Inspection System for Metal Matrix Composite Track Shoes

International Nuclear Information System (INIS)

Mi Bao; Zhao Xiaoliang; Qian Tao; Stevenson, Mark; Kwan, Chiman; Owens, Steven E.; Royer, Roger L. Jr.; Tittmann, Bernhard R.; Raju, Basavaraju B.

2007-01-01

Cast aluminum track shoes reinforced with metal matrix composite (MMC) inserts at heavy loading areas such as center splines and sprocket windows are light in weight, and can resist high temperature and wear. Various defects such as disbonds at the insert-substrate interface, cracks and porosity in the MMC layer, etc. can be introduced during the manufacturing process and/or in service. This paper presents a portable ultrasonic system to automatically inspect tank track shoes for disbond. Ultrasonic pulse/echo inspection has shown good reliability for disbond detection. A prototype sensor array fixture has been designed and fabricated to prove the feasibility. Good agreements between the sensor fixture results and ultrasonic C-scan images were obtained

BODY SIZE AND HAREM SIZE IN MALE RED-WINGED BLACKBIRDS: MANIPULATING SELECTION WITH SEX-SPECIFIC FEEDERS.

Science.gov (United States)

Rohwer, Sievert; Langston, Nancy; Gori, Dave

1996-10-01

We experimentally manipulated the strength of selection in the field on red-winged blackbirds (Agelaius phoeniceus) to test hypotheses about contrasting selective forces that favor either large or small males in sexually size dimorphic birds. Selander (1972) argued that sexual selection favors larger males, while survival selection eventually stabilizes male size because larger males do not survive as well as smaller males during harsh winters. Searcy (1979a) proposed instead that sexual selection may be self limiting: male size might be stabilized not by overwinter mortality, but by breeding-season sexual selection that favors smaller males. Under conditions of energetic stress, smaller males should be able to display more and thus achieve higher reproductive success. Using feeders that provisioned males or females but not both, we produced conditions that mimicked the extremes of natural conditions. We found experimental support for the hypothesis that when food is abundant, sexual selection favors larger males. But even under conditions of severe energetic stress, smaller males did not gain larger harems, as the self-limiting hypothesis predicted. Larger males were more energetically stressed than smaller males, but in ways that affected their future reproductive output rather than their current reproductive performance. Stressed males that returned had smaller wings and tails than those that did not return; among returning stressed males, relative harem sizes were inversely related to wing and tail length. Thus, male body size may be stabilized not by survival costs during the non-breeding season, nor by energetic costs during the breeding season, but by costs of future reproduction that larger males pay for their increased breeding-season effort. © 1996 The Society for the Study of Evolution.

Evolution of brain region volumes during artificial selection for relative brain size.

Science.gov (United States)

Kotrschal, Alexander; Zeng, Hong-Li; van der Bijl, Wouter; Öhman-Mägi, Caroline; Kotrschal, Kurt; Pelckmans, Kristiaan; Kolm, Niclas

2017-12-01

The vertebrate brain shows an extremely conserved layout across taxa. Still, the relative sizes of separate brain regions vary markedly between species. One interesting pattern is that larger brains seem associated with increased relative sizes only of certain brain regions, for instance telencephalon and cerebellum. Till now, the evolutionary association between separate brain regions and overall brain size is based on comparative evidence and remains experimentally untested. Here, we test the evolutionary response of brain regions to directional selection on brain size in guppies (Poecilia reticulata) selected for large and small relative brain size. In these animals, artificial selection led to a fast response in relative brain size, while body size remained unchanged. We use microcomputer tomography to investigate how the volumes of 11 main brain regions respond to selection for larger versus smaller brains. We found no differences in relative brain region volumes between large- and small-brained animals and only minor sex-specific variation. Also, selection did not change allometric scaling between brain and brain region sizes. Our results suggest that brain regions respond similarly to strong directional selection on relative brain size, which indicates that brain anatomy variation in contemporary species most likely stem from direct selection on key regions. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

Kinematic analysis of postural reactions to a posterior translation in rocker bottom shoes in younger and older adults.

Science.gov (United States)

Kimel-Scott, Dorothy R; Gulledge, Elisha N; Bolena, Ryan E; Albright, Bruce C

2014-01-01

Shoes with rocker bottom soles are utilized by persons with diabetic peripheral neuropathy to reduce plantar pressures during gait. The risk of falls increases with age and is compounded by diabetic neuropathy. The purpose of this study was to analyze how rocker bottom shoes affect posture control of older adults (50-75 years old) and younger adults (20-35 years old) in response to posterior slide perturbations. The postural response to a posterior platform translation was normalized among subjects by applying the below threshold stepping velocity (BTSV) for each subject. The BTSV was the fastest velocity of platform translation that did not cause a stepping response while wearing the rocker bottom shoes. Joint excursion, time to first response, response time, and variability of mean peak joint angles were analyzed at the ankle, knee, hip, trunk, and head in the sagittal plane. The statistical analysis was a 2-factor mixed repeated measures design to determine interactions between and within shoe types and age groups. While wearing rocker bottom shoes, both age groups exhibited increased joint excursion, differences in time to initial response, and longer response time. The older group demonstrated decreased joint excursion and increased time to initial response compared to the younger group, as well as a significantly slower mean BTSV. These findings support the conclusion that in healthy older adults and in populations at risk for falls, the use of rocker bottom or other unstable shoes may increase the potential of falls when confronted with a standing perturbation such as a forceful slip or trip. Copyright © 2013 Elsevier B.V. All rights reserved.

Hand and shoe monitor using air ionization probes

International Nuclear Information System (INIS)

Fergus, R.W.

1981-01-01

A hand and shoe radiation monitor is provided which includes a probe support body defining a plurality of cells, within each cell there being an ionization probe. The support body provides structural strength for protecting the ionization probes from force applied to the support body during a radiation monitoring event. There is also provided a fast response time amplifier circuit for the output from the ionization probes

The Comparison of two models of marker – placement for identifying the rear foot angle in normal people with and without shoes during the stance phase of walking

Directory of Open Access Journals (Sweden)

2016-09-01

Full Text Available Objective: The purpose of this study was to compare the two models of marker placement for identifying of rear foot angle in normal people with and without shoes during the different stage of stance phase of walking. Methods: Fifteen male students in Birjand University were selected based on Navicular Drop Index. After marker placement based on Clarke and Nigg models, the rear foot angle were recorded with two-dimensional analysis (Panasonic Camera from behind position while subjects walked with 1.7 m/s on a treadmill with and without shoes. For statistical analysis, independent samples t-test was used (p≤0.05. Results: The Results showed a significant difference in rear foot angle during the stance phase between the two models of Clarke and Nigg during walking with and without shoes (p≤0.001. Conclusion: Based on the results of the present study, due to their specific features care must be considered when using any of these two models to investigate the angular kinematics of the foot.

Do running speed and shoe cushioning influence impact loading and tibial shock in basketball players?

Directory of Open Access Journals (Sweden)

Wing-Kai Lam

2018-05-01

Full Text Available Background Tibial stress fracture (TSF is a common injury in basketball players. This condition has been associated with high tibial shock and impact loading, which can be affected by running speed, footwear condition, and footstrike pattern. However, these relationships were established in runners but not in basketball players, with very little research done on impact loading and speed. Hence, this study compared tibial shock, impact loading, and foot strike pattern in basketball players running at different speeds with different shoe cushioning properties/performances. Methods Eighteen male collegiate basketball players performed straight running trials with different shoe cushioning (regular-, better-, and best-cushioning and running speed conditions (3.0 m/s vs. 6.0 m/s on a flat instrumented runway. Tri-axial accelerometer, force plate and motion capture system were used to determine tibial accelerations, vertical ground reaction forces and footstrike patterns in each condition, respectively. Comfort perception was indicated on a 150 mm Visual Analogue Scale. A 2 (speed × 3 (footwear repeated measures ANOVA was used to examine the main effects of shoe cushioning and running speeds. Results Greater tibial shock (P 0.14; η2 = 0.13. Discussion There may be an optimal band of shoe cushioning for better protection against TSF. These findings may provide insights to formulate rehabilitation protocols for basketball players who are recovering from TSF.

Prey size selection and cannibalistic behaviour of juvenile barramundi Lates calcarifer.

Science.gov (United States)

Ribeiro, F F; Qin, J G

2015-05-01

This study assessed the cannibalistic behaviour of juvenile barramundi Lates calcarifer and examined the relationship between prey size selection and energy gain of cannibals. Prey handling time and capture success by cannibals were used to estimate the ratio of energy gain to energy cost in prey selection. Cannibals selected smaller prey despite its capability of ingesting larger prey individuals. In behavioural analysis, prey handling time significantly increased with prey size, but it was not significantly affected by cannibal size. Conversely, capture success significantly decreased with the increase of both prey and cannibal sizes. The profitability indices showed that the smaller prey provides the most energy return for cannibals of all size classes. These results indicate that L. calcarifer cannibals select smaller prey for more profitable return. The behavioural analysis, however, indicates that L. calcarifer cannibals attack prey of all size at a similar rate but ingest smaller prey more often, suggesting that prey size selection is passively orientated rather than at the predator's choice. The increase of prey escape ability and morphological constraint contribute to the reduction of intracohort cannibalism as fish grow larger. This study contributes to the understanding of intracohort cannibalism and development of strategies to reduce fish cannibalistic mortalities. © 2015 The Fisheries Society of the British Isles.

A Shoe-Embedded Piezoelectric Energy Harvester for Wearable Sensors

Directory of Open Access Journals (Sweden)

Jingjing Zhao

2014-07-01

Full Text Available Harvesting mechanical energy from human motion is an attractive approach for obtaining clean and sustainable electric energy to power wearable sensors, which are widely used for health monitoring, activity recognition, gait analysis and so on. This paper studies a piezoelectric energy harvester for the parasitic mechanical energy in shoes originated from human motion. The harvester is based on a specially designed sandwich structure with a thin thickness, which makes it readily compatible with a shoe. Besides, consideration is given to both high performance and excellent durability. The harvester provides an average output power of 1 mW during a walk at a frequency of roughly 1 Hz. Furthermore, a direct current (DC power supply is built through integrating the harvester with a power management circuit. The DC power supply is tested by driving a simulated wireless transmitter, which can be activated once every 2–3 steps with an active period lasting 5 ms and a mean power of 50 mW. This work demonstrates the feasibility of applying piezoelectric energy harvesters to power wearable sensors.

Model catalysis by size-selected cluster deposition

Energy Technology Data Exchange (ETDEWEB)

Anderson, Scott [Univ. of Utah, Salt Lake City, UT (United States)

2015-11-20

This report summarizes the accomplishments during the last four years of the subject grant. Results are presented for experiments in which size-selected model catalysts were studied under surface science and aqueous electrochemical conditions. Strong effects of cluster size were found, and by correlating the size effects with size-dependent physical properties of the samples measured by surface science methods, it was possible to deduce mechanistic insights, such as the factors that control the rate-limiting step in the reactions. Results are presented for CO oxidation, CO binding energetics and geometries, and electronic effects under surface science conditions, and for the electrochemical oxygen reduction reaction, ethanol oxidation reaction, and for oxidation of carbon by water.

The effect of shoe design and lateral wedges on knee load and neuromuscular control in healthy subjects during walking

DEFF Research Database (Denmark)

Mølgaard, Carsten Møller; Kersting, Uwe G.

2013-01-01

and second peak knee adduction moments. However, the variability of this moment between shoe designs was of similar magnitude as the effect of laterally wedged insoles. Only marginal changes in muscle activity for gastrocnemius when walking with the wedged Oxford shoe were revealed. Conclusion: Lateral...

Shoe collar height effect on athletic performance, ankle joint kinematics and kinetics during unanticipated maximum-effort side-cutting performance.

Science.gov (United States)

Lam, Gilbert Wing Kai; Park, Eun Jung; Lee, Ki-Kwang; Cheung, Jason Tak-Man

2015-01-01

Side-step cutting manoeuvres comprise the coordination between planting and non-planting legs. Increased shoe collar height is expected to influence ankle biomechanics of both legs and possibly respective cutting performance. This study examined the shoe collar height effect on kinematics and kinetics of planting and non-planting legs during an unanticipated side-step cutting. Fifteen university basketball players performed maximum-effort side-step cutting to the left 45° direction or a straight ahead run in response to a random light signal. Seven successful cutting trials were collected for each condition. Athletic performance, ground reaction force, ankle kinematics and kinetics of both legs were analysed using paired t-tests. Results indicated that high-collar shoes resulted in less ankle inversion and external rotation during initial contact for the planting leg. The high-collar shoes also exhibited a smaller ankle range of motion in the sagittal and transverse planes for both legs, respectively. However, no collar effect was found for ankle moments and performance indicators including cutting performance time, ground contact time, propulsion ground reaction forces and impulses. These findings indicated that high-collar shoes altered ankle positioning and restricted ankle joint freedom movements in both legs, while no negative effect was found for athletic cutting performance.

Deposition of Size-Selected Cu Nanoparticles by Inert Gas Condensation

Directory of Open Access Journals (Sweden)

Martínez E

2009-01-01

Full Text Available Abstract Nanometer size-selected Cu clusters in the size range of 1–5 nm have been produced by a plasma-gas-condensation-type cluster deposition apparatus, which combines a grow-discharge sputtering with an inert gas condensation technique. With this method, by controlling the experimental conditions, it was possible to produce nanoparticles with a strict control in size. The structure and size of Cu nanoparticles were determined by mass spectroscopy and confirmed by atomic force microscopy (AFM and scanning electron transmission microscopy (STEM measurements. In order to preserve the structural and morphological properties, the energy of cluster impact was controlled; the energy of acceleration of the nanoparticles was in near values at 0.1 ev/atom for being in soft landing regime. From SEM measurements developed in STEM-HAADF mode, we found that nanoparticles are near sized to those values fixed experimentally also confirmed by AFM observations. The results are relevant, since it demonstrates that proper optimization of operation conditions can lead to desired cluster sizes as well as desired cluster size distributions. It was also demonstrated the efficiency of the method to obtain size-selected Cu clusters films, as a random stacking of nanometer-size crystallites assembly. The deposition of size-selected metal clusters represents a novel method of preparing Cu nanostructures, with high potential in optical and catalytic applications.

Species selectivity in different sized topless trawl designs: Does size matter?

DEFF Research Database (Denmark)

Krag, Ludvig Ahm; Herrmann, Bent; Karlsen, Junita Diana

2015-01-01

-specific quotas. The toplesstrawl design was developed to improve species-specific selectivity in such fisheries. In a topless trawl,the foot rope is located more forward than the headline to allow fish to escape upwards, whereas theheadline is located in front in traditional trawl designs. In this study we...... Atlantic, topless trawls have been introducedas legal cod-selective trawl designs. However, this study demonstrates that identical gear modificationsmade to similar trawls of different sizes and used in the same fishery can lead to different results....

Biomechanics of slow running and walking with a rocker shoe

NARCIS (Netherlands)

Sobhani, Sobhan; Hijmans, Juha; van den Heuvel, Edwin; Zwerver, Johannes; Dekker, Rienk; Postema, Klaas

Evidence suggests a link between the loading of the Achilles tendon and the magnitude of the ankle internal plantar flexion moment during late stance of gait, which is clinically relevant in the management of Achilles tendinopathy. Some studies showed that rocker shoes can reduce the ankle internal

Seed predators exert selection on the subindividual variation of seed size.

Science.gov (United States)

Sobral, M; Guitián, J; Guitián, P; Larrinaga, A R

2014-07-01

Subindividual variation among repeated organs in plants constitutes an overlooked level of variation in phenotypic selection studies, despite being a major component of phenotypic variation. Animals that interact with plants could be selective agents on subindividual variation. This study examines selective pressures exerted during post-dispersal seed predation and germination on the subindividual variation of seed size in hawthorn (Crataegus monogyna). With a seed offering experiment and a germination test, we estimated phenotypic selection differentials for average and subindividual variation of seed size due to seed predation and germination. Seed size affects germination, growth rate and the probability of an individual seed of escaping predation. Longer seeds showed higher germination rates, but this did not result in significant selection on phenotypes of the maternal trees. On the other hand, seed predators avoided wider seeds, and by doing so exerted phenotypic selection on adult average and subindividual variation of seed size. The detected selection on subindividual variation suggests that the levels of phenotypic variation within individual plants may be, at least partly, the adaptive consequence of animal-mediated selection. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

The influence of shoe drop on the kinematics and kinetics of children tennis players.

Science.gov (United States)

Herbaut, Alexis; Chavet, Pascale; Roux, Maxime; Guéguen, Nils; Gillet, Christophe; Barbier, Franck; Simoneau-Buessinger, Emilie

2016-11-01

This study investigated the immediate effects of reducing the shoe drop (i.e. the difference between the heel and the forefoot height) on the kinematics and kinetics of the lower extremities of children tennis players performing a tennis-specific movement. Thirteen children tennis players performed a series of simulated open stance forehands wearing 3 pairs of shoes differing only in the drop: 0 (D0), 6 (D6) and the control condition of 12 mm (D12). Two embedded forceplates and a motion capture system were used to analyse the ground reaction forces and ankle and knee joint angles and moments of the leading lower limb. In D6 compared with D12, the peak impact force was reduced by 24% (p = .004) and the ankle was less dorsiflexed at foot strike (p = .037). In D0 compared with D12, the peak impact force was reduced by 17% (p = .049), the ankle was less dorsiflexed at foot strike (p = .045) and the knee was more flexed at foot strike (p = .007). In addition, 4 out of 13 participants (31%) presented a forefoot strike pattern for some of the trials in D0. No difference was observed across shoe conditions for the peak knee extensor moment (p = .658) or the peak ankle plantarflexor moment (p = .071). The results provide preliminary data supporting the hypothesis that for children tennis players, using a 6-mm lower shoe drop might reduce heel impact forces and thus limit potentially impact-related injuries.

Influence of running shoes and cross-trainers on Achilles tendon forces during running compared with military boots.

Science.gov (United States)

Sinclair, Jonathan; Taylor, P J; Atkins, S

2015-06-01

Military recruits are known to be susceptible to Achilles tendon pathology. The British Army have introduced footwear models, the PT-03 (cross-trainer) and PT1000 (running shoes), in an attempt to reduce the incidence of injuries. The aim of the current investigation was to examine the Achilles tendon forces of the cross-trainer and running shoe in relation to conventional army boots. Ten male participants ran at 4.0 m/s in each footwear condition. Achilles tendon forces were obtained throughout the stance phase of running and compared using repeated-measures ANOVAs. The results showed that the time to peak Achilles tendon force was significantly shorter when running in conventional army boots (0.12 s) in comparison with the cross-trainer (0.13 s) and running shoe (0.13 s). Achilles tendon loading rate was shown to be significantly greater in conventional army boots (38.73 BW/s) in comparison with the cross-trainer (35.14 BW/s) and running shoe (33.57 BW/s). The results of this study suggest that the running shoes and cross-trainer footwear are associated with reductions in Achilles tendon parameters that have been linked to the aetiology of injury, and thus it can be hypothesised that these footwear could be beneficial for military recruits undertaking running exercises. 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.

Influence of the Heel-to-Toe Drop of Standard Cushioned Running Shoes on Injury Risk in Leisure-Time Runners: A Randomized Controlled Trial With 6-Month Follow-up.

Science.gov (United States)

Malisoux, Laurent; Chambon, Nicolas; Urhausen, Axel; Theisen, Daniel

2016-11-01

Modern running shoes are available in a wide range of heel-to-toe drops (ie, the height difference between the forward and rear parts of the inside of the shoe). While shoe drop has been shown to influence strike pattern, its effect on injury risk has never been investigated. Therefore, the reasons for such variety in this parameter are unclear. The first aim of this study was to determine whether the drop of standard cushioned running shoes influences running injury risk. The secondary aim was to investigate whether recent running regularity modifies the relationship between shoe drop and injury risk. Randomized controlled trial; Level of evidence, 1. Leisure-time runners (N = 553) were observed for 6 months after having received a pair of shoes with a heel-to-toe drop of 10 mm (D10), 6 mm (D6), or 0 mm (D0). All participants reported their running activities and injuries (time-loss definition, at least 1 day) in an electronic system. Cox regression analyses were used to compare injury risk between the 3 groups based on hazard rate ratios (HRs) and their 95% CIs. A stratified analysis was conducted to evaluate the effect of shoe drop in occasional runners (running regularity, low-drop shoes (D6 and D0) were found to be associated with a lower injury risk in occasional runners (HR, 0.48; 95% CI, 0.23-0.98), whereas these shoes were associated with a higher injury risk in regular runners (HR, 1.67; 95% CI, 1.07-2.62). Overall, injury risk was not modified by the drop of standard cushioned running shoes. However, low-drop shoes could be more hazardous for regular runners, while these shoes seem to be preferable for occasional runners to limit injury risk. © 2016 The Author(s).

Injury Reduction Effectiveness of Prescribing Running Shoes Based on Foot Shape in Air Force Basic Military Training

Science.gov (United States)

2008-08-01

resulted in excessive pronation, creating a torsional force that repeatedly overstretched the plantar fascia leading to the fasciitis. However, the...Defense Safety Oversight Council, this study examined whether prescribing running shoes based on the shape of the plantar surface influenced injury risk...prescribed motion control, stability, or cushioned shoes for plantar shapes indicative of low, medium, or high arches, respectively. A control group (C, n

Effect of shoe type on plantar pressure: a gender comparison

NARCIS (Netherlands)

Queen, Robin M.; Abbey, Alicia N.; Wiegerinck, Johannes I.; Yoder, Jordan C.; Nunley, James A.

2010-01-01

Despite the differences in materials, racing flats have begun to be used not only for racing, but also for daily training. As there are data suggesting a gender difference in overuse injuries in runners, shoe choice may affect loading patterns during running. The purpose was to determine differences

A change in competitive context reverses sexual selection on male size.

Science.gov (United States)

Kasumovic, M M; Andrade, M C B

2009-02-01

In studies of sexual selection, larger size is often argued to increase male fitness, and relatively smaller males are explained by genetic and/or environmental variation. We demonstrate that a size-development life-history trade-off could underlie the maintenance of a broad, unimodal distribution of size in male redback spiders (Latrodectus hasselti). Larger males are superior in direct competition, but redback males mature rapidly at small size in the presence of females. In field enclosures, we simulated two competitive contexts favouring development of divergent male sizes. Relatively smaller males lost when competing directly, but had 10 times higher fitness than relatively larger males when given the temporal advantage of rapid development. Linear selection gradients confirmed the reversal of selection on size, showing that it is critical to consider life-history decisions underlying the development of traits related to fitness.

A novel magnet based 3D printed marker wand as basis for repeated in-shoe multi segment foot analysis: a proof of concept.

Science.gov (United States)

Eerdekens, Maarten; Staes, Filip; Pilkington, Thomas; Deschamps, Kevin

2017-01-01

Application of in-shoe multi-segment foot kinematic analyses currently faces a number of challenges, including: (i) the difficulty to apply regular markers onto the skin, (ii) the necessity for an adequate shoe which fits various foot morphologies and (iii) the need for adequate repeatability throughout a repeated measure condition. The aim of this study therefore was to design novel magnet based 3D printed markers for repeated in-shoe measurements while using accordingly adapted modified shoes for a specific multi-segment foot model. Multi-segment foot kinematics of ten participants were recorded and kinematics of hindfoot, midfoot and forefoot were calculated. Dynamic trials were conducted to check for intra and inter-session repeatability when combining novel markers and modified shoes in a repeated measures design. Intraclass correlation coefficients were calculated to determine reliability. Both repeatability and reliability were proven to be good to excellent with maximum joint angle deviations of 1.11° for intra-session variability and 1.29° for same-day inter-session variability respectively and ICC values of >0.91. The novel markers can be reliably used in future research settings using in-shoe multi-segment foot kinematic analyses with multiple shod conditions.

Effect on injuries of assigning shoes based on foot shape in air force basic training.

Science.gov (United States)

Knapik, Joseph J; Brosch, Lorie C; Venuto, Margaret; Swedler, David I; Bullock, Steven H; Gaines, Lorraine S; Murphy, Ryan J; Tchandja, Juste; Jones, Bruce H

2010-01-01

This study examined whether assigning running shoes based on the shape of the bottom of the foot (plantar surface) influenced injury risk in Air Force Basic Military Training (BMT) and examined risk factors for injury in BMT. Data were collected from BMT recruits during 2007; analysis took place during 2008. After foot examinations, recruits were randomly consigned to either an experimental group (E, n=1042 men, 375 women) or a control group (C, n=913 men, 346 women). Experimental group recruits were assigned motion control, stability, or cushioned shoes for plantar shapes indicative of low, medium, or high arches, respectively. Control group recruits received a stability shoe regardless of plantar shape. Injuries during BMT were determined from outpatient visits provided from the Defense Medical Surveillance System. Other injury risk factors (fitness, smoking, physical activity, prior injury, menstrual history, and demographics) were obtained from a questionnaire, existing databases, or BMT units. Multivariate Cox regression controlling for other risk factors showed little difference in injury risk between the groups among men (hazard ratio [E/C]=1.11, 95% CI=0.89-1.38) or women (hazard ratio [E/C]=1.20, 95% CI= 0.90-1.60). Independent injury risk factors among both men and women included low aerobic fitness and cigarette smoking. This prospective study demonstrated that assigning running shoes based on the shape of the plantar surface had little influence on injury risk in BMT even after controlling for other injury risk factors. Published by Elsevier Inc.

Antarctic krill; assessment of mesh size selectivity and escape mortality from trawls

DEFF Research Database (Denmark)

Krafft, Bjørn A.; Krag, Ludvig Ahm; Herrmann, Bent

2015-01-01

Marine AS. The project will examine krill escape mortality from the codend during a full scale field experiment, model size selectivity and escape mortality in codends including different designs and assess the size selectivity in the trawl body forward of the codend. Based on end results from the preceding...... examinations we will be able to predict size selectivity and escape mortality from the entire trawl body with the appurtenant mortality for different trawl designs......This working paper presents the aims and methodology for a three-year-project (commenced in 2015) assessing size selectivity and escape mortality of Antarctic krill from trawl nets. The project is widely based on acquired experiences from a completed study Net Escapement of Antarctic krill...

Quantitative self-assessment of exposure to solvents among shoe repair men

NARCIS (Netherlands)

Hertsenberg, S.; Brouwer, D.; Lurvink, M.; Rubingh, C.; Rijnders, E.; Tielemans, E.

2007-01-01

Self-assessment of exposure (SAE) refers to any exposure assessment methodology wherein the worker takes an active role in establishing his or her exposure status. The objective of this study was to investigate the reliability and feasibility of SAE approaches among shoe repair workers collecting

Effect of surgical shoes on brake response time after first metatarsal osteotomy--a prospective cohort study.

Science.gov (United States)

Dammerer, Dietmar; Braito, Matthias; Biedermann, Rainer; Ban, Michael; Giesinger, Johannes; Haid, Christian; Liebensteiner, Michael C; Kaufmann, Gerhard

2016-01-20

The aim of this study is to assess patients' driving ability when wearing surgical shoes following right-sided first metatarsal osteotomy. From August 2013 to August 2015, 42 consecutive patients (mean age 54.5 years) with right-sided hallux valgus deformity underwent first metatarsal osteotomy. Patients were tested for brake response time (BRT) 1 day preoperatively (control run) and at 2 and 6 weeks postoperatively. Two different types of foot orthosis were investigated. BRT was assessed using a custom-made driving simulator. Preoperative BRT was 712 msec (standard deviation (SD), 221 msec). BRT was significantly slower at all tested postoperative times than preoperatively (p shoes. Mean global American Orthopaedic Foot and Ankle Society (AOFAS) outcome score and AOFAS pain and alignment subscores increased postoperatively (p shoe after bunionectomy. However, patients should have sufficient recovery, exercise, and training before resuming driving a car, because safety is always a priority. ClinicalTrials.gov, NCT02354066.

Clutches and brakes design and selection

CERN Document Server

Orthwein, William C

2004-01-01

FRICTION MATERIALSFriction CodeWearBrake FadeFriction MaterialsNotationReferencesBAND BRAKESDerivation of EquationsApplicationLever-Actuated Band Brake: Backstop DesignExample: Design of a BackstopNotationFormula CollectionReferencesEXTERNALLY AND INTERNALLY PIVOTED SHOE BRAKESPivoted External Drum BrakesPivoted Internal Drum BrakesDesign of Dual-Anchor Twin-Shoe Drum BrakesDual-Anchor Twin-Shoe Drum Brake Design ExamplesDesign of Single-Anchor Twin-Shoe Drum BrakesSingle-Anchor Twin-Shoe Drum Brake Design Exam

Selective attention supports working memory maintenance by modulating perceptual processing of distractors.

Science.gov (United States)

Sreenivasan, Kartik K; Jha, Amishi P

2007-01-01

Selective attention has been shown to bias sensory processing in favor of relevant stimuli and against irrelevant or distracting stimuli in perceptual tasks. Increasing evidence suggests that selective attention plays an important role during working memory maintenance, possibly by biasing sensory processing in favor of to-be-remembered items. In the current study, we investigated whether selective attention may also support working memory by biasing processing against irrelevant and potentially distracting information. Event-related potentials (ERPs) were recorded while subjects (n = 22) performed a delayed-recognition task for faces and shoes. The delay period was filled with face or shoe distractors. Behavioral performance was impaired when distractors were congruent with the working memory domain (e.g., face distractor during working memory for faces) relative to when distractors were incongruent with the working memory domain (e.g., face distractor during shoe working memory). If attentional biasing against distractor processing is indeed functionally relevant in supporting working memory maintenance, perceptual processing of distractors is predicted to be attenuated when distractors are more behaviorally intrusive relative to when they are nonintrusive. As such, we predicted that perceptual processing of distracting faces, as measured by the face-sensitive N170 ERP component, would be reduced in the context of congruent (face) working memory relative to incongruent (shoe) working memory. The N170 elicited by distracting faces demonstrated reduced amplitude during congruent versus incongruent working memory. These results suggest that perceptual processing of distracting faces may be attenuated due to attentional biasing against sensory processing of distractors that are most behaviorally intrusive during working memory maintenance.

Evidence of size-selective evolution in the fighting conch from prehistoric subsistence harvesting.

Science.gov (United States)

O'Dea, Aaron; Shaffer, Marian Lynne; Doughty, Douglas R; Wake, Thomas A; Rodriguez, Felix A

2014-05-07

Intensive size-selective harvesting can drive evolution of sexual maturity at smaller body size. Conversely, prehistoric, low-intensity subsistence harvesting is not considered an effective agent of size-selective evolution. Uniting archaeological, palaeontological and contemporary material, we show that size at sexual maturity in the edible conch Strombus pugilis declined significantly from pre-human (approx. 7 ka) to prehistoric times (approx. 1 ka) and again to the present day. Size at maturity also fell from early- to late-prehistoric periods, synchronous with an increase in harvesting intensity as other resources became depleted. A consequence of declining size at maturity is that early prehistoric harvesters would have received two-thirds more meat per conch than contemporary harvesters. After exploring the potential effects of selection biases, demographic shifts, environmental change and habitat alteration, these observations collectively implicate prehistoric subsistence harvesting as an agent of size-selective evolution with long-term detrimental consequences. We observe that contemporary populations that are protected from harvesting are slightly larger at maturity, suggesting that halting or even reversing thousands of years of size-selective evolution may be possible.

Sexual selection and the evolution of brain size in primates.

Science.gov (United States)

Schillaci, Michael A

2006-12-20

Reproductive competition among males has long been considered a powerful force in the evolution of primates. The evolution of brain size and complexity in the Order Primates has been widely regarded as the hallmark of primate evolutionary history. Despite their importance to our understanding of primate evolution, the relationship between sexual selection and the evolutionary development of brain size is not well studied. The present research examines the evolutionary relationship between brain size and two components of primate sexual selection, sperm competition and male competition for mates. Results indicate that there is not a significant relationship between relative brain size and sperm competition as measured by relative testis size in primates, suggesting sperm competition has not played an important role in the evolution of brain size in the primate order. There is, however, a significant negative evolutionary relationship between relative brain size and the level of male competition for mates. The present study shows that the largest relative brain sizes among primate species are associated with monogamous mating systems, suggesting primate monogamy may require greater social acuity and abilities of deception.

Vertical ground reaction force analysis during gait with unstable shoes

Directory of Open Access Journals (Sweden)

Giulia Pereira

Full Text Available AbstractIntroduction Footwear is no longer just an accessory but also a protection for the musculoskeletal system, and its most important characteristic is comfort.Objectives This study aims to identify and to analyze the vertical ground reaction force in barefoot women and women with unstable shoes.Methodology Five women aged 25 ± 4 years old and mass of 50 ± 7 kg participated in this study. An AMTI force plate was used for data acquisition. The 10 trials for each situation were considered valid where the subject approached the platform with the right foot and at the speed of 4 km/h ± 5%. The instable shoe of this study is used in the practice of physical activity.Results The results showed that the first peak force was higher for the footwear situation, about 5% and significant differences between the barefoot and footwear situation. This significant difference was in the first and second peaks force and in the time of the second peak.Conclusion The values showed that the footwear absorbs approximately 45% of the impact during gait.

Occupational skin hazards and prevalence of occupational skin diseases in shoe manufacturing workers in Indonesia.

Science.gov (United States)

Febriana, Sri Awalia; Soebono, Hardyanto; Coenraads, Pieter-Jan

2014-02-01

Shoe manufacturing workers are exposed daily to an extensive range of potential physical and chemical occupational hazards. Shoe manufacturing in Indonesia is one of the industrial sectors that has shown sustained growth amongst the newly industrialized countries (NICs). In this study, we investigated the possible potential exposure of the workers to physical and occupational hazards and determined the prevalence of occupational skin diseases at a shoe manufacturing factory in Indonesia. A cross-sectional study on the observation of the working process and an inventory and risk assessment of exposure to the chemicals used. Classification of chemicals as potential sensitizers/irritants and qualitative assessments of these chemicals were done. Workers were examined and interviewed using the Nordic Occupational Skin Questionnaire-2002/LONG. The risk of Occupational skin diseases (OSD) at the shoe factory was mainly related to the exposure of the workers' skin to potential physical and chemical hazards in hot and humid environmental conditions. From a total of 514 workers, 8.5 % reported current OSD and 4.8 % reported a history of OSD. Occupational skin diseases were diagnosed in 29 % of the workers by dermatologists and 7.6 % had an occupational contact dermatitis (OCD). Of the 39 workers with contact dermatitis, 33 consented to being patch tested, 14 (3 %) workers showed a positive results and considered as having an occupational allergic contact dermatitis (OACD) and 25 (4.9 %) had an occupational irritant contact dermatitis (OICD). We observed a repeated and prolonged exposure of the workers to numerous physical and chemical skin hazards at this factory.

[Dancing with Pointe Shoes: Characteristics and Assessment Criteria for Pointe Readiness].

Science.gov (United States)

Wanke, Eileen M; Exner-Grave, Elisabeth

2017-12-01

Training with pointe shoes is an integral part of professional dance education and ambitious hobby dancing. Pointe shoes - developed more than hundred years ago and almost unaltered since then - are highly specific and strike a balance between aesthetics, function, protection, and health care. Therefore, pointe readiness should be tested prior to all dance training or career training. Medical specialists are often confronted with this issue. Specific anatomical dance technique-orientated general conditional and coordinative preconditions as well as dance-technical prerequisites must be met by pointe readiness tests in order to keep traumatic injuries or long-term damage at a minimum. In addition to a (training) history, medical counselling sessions have come to include various tests that enable a reliable decision for or against pointe work. This article suggests adequate testing procedures (STT TEST), taking account of professional dancing as well as hobby dancing. © Georg Thieme Verlag KG Stuttgart · New York.

Urban prevalence of Listeria spp. and Listeria monocytogenes in public lavatories and on shoe soles of facility patrons in the European capital city Vienna.

Science.gov (United States)

Schoder, D; Schmalwieser, A; Szakmary-Brändle, K; Stessl, B; Wagner, M

2015-05-01

The aim of this study was to determine the prevalence of Listeria spp. and Listeria monocytogenes (L. monocytogenes) in urban public lavatories and on shoe soles of facility patrons in a European capital city. More than 91% of all municipal public lavatories in Vienna close to public hubs were included in this study. Overall, 373 swab samples of public lavatories and shoes of facility patrons were enriched, according to ISO 11290-1. Listeria monocytogenes isolates were subtyped using pulsed-field gel electrophoresis. A total of 24 samples were positive for Listeria spp., yielding an overall prevalence of 6.4% (24/373). Listeria monocytogenes was found in 2.1% (8/373) of all samples. Swabs from lavatories in parks, container lavatories and lavatories at markets had the highest prevalences of 20.7% (6/29), 20% (2/10) and 12.5% (1/8) Listeria spp., respectively. These detection rates were statistically significantly higher than those associated with lavatories in shopping centres (P = 0.003, P = 0.002, P = 0.02) and at public transport locations (P = 0.0004, P = 0.005, P = 0.02). Shoes sampled at Christmas markets showed the highest Listeria spp. and L. monocytogenes prevalences of 80% (4/5) and 40% (2/5), respectively. With regard to shoe type, Listeria spp. detection rates were 14.3% (3/21; winter boots), 13.3% (2/15; hiking boots), sport shoes (5.9%; 2/34) and brogues (5.1%; 4/79). No Listeria spp. were found on shoe soles that had smooth treads (0/76), while Listeria spp. were detected on 19.5% (8/41) of medium depth tread shoe types and on 9.4% (3/32) of deep tread shoes. These data suggest that soil environment is still one of the most important reservoirs for the foodborne pathogen L. monocytogenes. © 2014 Blackwell Verlag GmbH.

Body size, swimming speed, or thermal sensitivity? Predator-imposed selection on amphibian larvae.

Science.gov (United States)

Gvoždík, Lumír; Smolinský, Radovan

2015-11-02

Many animals rely on their escape performance during predator encounters. Because of its dependence on body size and temperature, escape velocity is fully characterized by three measures, absolute value, size-corrected value, and its response to temperature (thermal sensitivity). The primary target of the selection imposed by predators is poorly understood. We examined predator (dragonfly larva)-imposed selection on prey (newt larvae) body size and characteristics of escape velocity using replicated and controlled predation experiments under seminatural conditions. Specifically, because these species experience a wide range of temperatures throughout their larval phases, we predict that larvae achieving high swimming velocities across temperatures will have a selective advantage over more thermally sensitive individuals. Nonzero selection differentials indicated that predators selected for prey body size and both absolute and size-corrected maximum swimming velocity. Comparison of selection differentials with control confirmed selection only on body size, i.e., dragonfly larvae preferably preyed on small newt larvae. Maximum swimming velocity and its thermal sensitivity showed low group repeatability, which contributed to non-detectable selection on both characteristics of escape performance. In the newt-dragonfly larvae interaction, body size plays a more important role than maximum values and thermal sensitivity of swimming velocity during predator escape. This corroborates the general importance of body size in predator-prey interactions. The absence of an appropriate control in predation experiments may lead to potentially misleading conclusions about the primary target of predator-imposed selection. Insights from predation experiments contribute to our understanding of the link between performance and fitness, and further improve mechanistic models of predator-prey interactions and food web dynamics.

Zooplankton size selection relative to gill raker spacing in rainbow trout

Science.gov (United States)

Budy, P.; Haddix, T.; Schneidervin, R.

2005-01-01

Rainbow trout Oncorhynchus mykiss are one of the most widely stocked salmonids worldwide, often based on the assumption that they will effectively utilize abundant invertebrate food resources. We evaluated the potential for feeding morphology to affect prey selection by rainbow trout using a combination of laboratory feeding experiments and field observations in Flaming Gorge Reservoir, Utah-Wyoming. For rainbow trout collected from the reservoir, inter-gill raker spacing averaged 1.09 mm and there was low variation among fish overall (SD = 0.28). Ninety-seven percent of all zooplankton observed in the diets of rainbow trout collected in the reservoir were larger than the interraker spacing, while only 29% of the zooplankton found in the environment were larger than the interraker spacing. Over the size range of rainbow trout evaluated here (200-475 mm), interraker spacing increased moderately with increasing fish length; however, the size of zooplankton found in the diet did not increase with increasing fish length. In laboratory experiments, rainbow trout consumed the largest zooplankton available; the mean size of zooplankton observed in the diets was significantly larger than the mean size of zooplankton available. Electivity indices for both laboratory and field observations indicated strong selection for larger-sized zooplankton. The size threshold at which electivity switched from selection against smaller-sized zooplankton to selection for larger-sized zooplankton closely corresponded to the mean interraker spacing for both groups (???1-1.2 mm). The combination of results observed here indicates that rainbow trout morphology limits the retention of different-sized zooplankton prey and reinforces the importance of understanding how effectively rainbow trout can utilize the type and sizes of different prey available in a given system. These considerations may improve our ability to predict the potential for growth and survival of rainbow trout within and

Scale-Dependent Habitat Selection and Size-Based Dominance in Adult Male American Alligators.

Directory of Open Access Journals (Sweden)

Bradley A Strickland

Full Text Available Habitat selection is an active behavioral process that may vary across spatial and temporal scales. Animals choose an area of primary utilization (i.e., home range then make decisions focused on resource needs within patches. Dominance may affect the spatial distribution of conspecifics and concomitant habitat selection. Size-dependent social dominance hierarchies have been documented in captive alligators, but evidence is lacking from wild populations. We studied habitat selection for adult male American alligators (Alligator mississippiensis; n = 17 on the Pearl River in central Mississippi, USA, to test whether habitat selection was scale-dependent and individual resource selectivity was a function of conspecific body size. We used K-select analysis to quantify selection at the home range scale and patches within the home range to determine selection congruency and important habitat variables. In addition, we used linear models to determine if body size was related to selection patterns and strengths. Our results indicated habitat selection of adult male alligators was a scale-dependent process. Alligators demonstrated greater overall selection for habitat variables at the patch level and less at the home range level, suggesting resources may not be limited when selecting a home range for animals in our study area. Further, diurnal habitat selection patterns may depend on thermoregulatory needs. There was no relationship between resource selection or home range size and body size, suggesting size-dependent dominance hierarchies may not have influenced alligator resource selection or space use in our sample. Though apparent habitat suitability and low alligator density did not manifest in an observed dominance hierarchy, we hypothesize that a change in either could increase intraspecific interactions, facilitating a dominance hierarchy. Due to the broad and diverse ecological roles of alligators, understanding the factors that influence their

Scale-dependent habitat selection and size-based dominance in adult male American alligators

Science.gov (United States)

Strickland, Bradley A.; Vilella, Francisco; Belant, Jerrold L.

2016-01-01

Habitat selection is an active behavioral process that may vary across spatial and temporal scales. Animals choose an area of primary utilization (i.e., home range) then make decisions focused on resource needs within patches. Dominance may affect the spatial distribution of conspecifics and concomitant habitat selection. Size-dependent social dominance hierarchies have been documented in captive alligators, but evidence is lacking from wild populations. We studied habitat selection for adult male American alligators (Alligator mississippiensis; n = 17) on the Pearl River in central Mississippi, USA, to test whether habitat selection was scale-dependent and individual resource selectivity was a function of conspecific body size. We used K-select analysis to quantify selection at the home range scale and patches within the home range to determine selection congruency and important habitat variables. In addition, we used linear models to determine if body size was related to selection patterns and strengths. Our results indicated habitat selection of adult male alligators was a scale-dependent process. Alligators demonstrated greater overall selection for habitat variables at the patch level and less at the home range level, suggesting resources may not be limited when selecting a home range for animals in our study area. Further, diurnal habitat selection patterns may depend on thermoregulatory needs. There was no relationship between resource selection or home range size and body size, suggesting size-dependent dominance hierarchies may not have influenced alligator resource selection or space use in our sample. Though apparent habitat suitability and low alligator density did not manifest in an observed dominance hierarchy, we hypothesize that a change in either could increase intraspecific interactions, facilitating a dominance hierarchy. Due to the broad and diverse ecological roles of alligators, understanding the factors that influence their social dominance

The reliability, accuracy and minimal detectable difference of a multi-segment kinematic model of the foot-shoe complex.

Science.gov (United States)

Bishop, Chris; Paul, Gunther; Thewlis, Dominic

2013-04-01

Kinematic models are commonly used to quantify foot and ankle kinematics, yet no marker sets or models have been proven reliable or accurate when wearing shoes. Further, the minimal detectable difference of a developed model is often not reported. We present a kinematic model that is reliable, accurate and sensitive to describe the kinematics of the foot-shoe complex and lower leg during walking gait. In order to achieve this, a new marker set was established, consisting of 25 markers applied on the shoe and skin surface, which informed a four segment kinematic model of the foot-shoe complex and lower leg. Three independent experiments were conducted to determine the reliability, accuracy and minimal detectable difference of the marker set and model. Inter-rater reliability of marker placement on the shoe was proven to be good to excellent (ICC=0.75-0.98) indicating that markers could be applied reliably between raters. Intra-rater reliability was better for the experienced rater (ICC=0.68-0.99) than the inexperienced rater (ICC=0.38-0.97). The accuracy of marker placement along each axis was <6.7 mm for all markers studied. Minimal detectable difference (MDD90) thresholds were defined for each joint; tibiocalcaneal joint--MDD90=2.17-9.36°, tarsometatarsal joint--MDD90=1.03-9.29° and the metatarsophalangeal joint--MDD90=1.75-9.12°. These thresholds proposed are specific for the description of shod motion, and can be used in future research designed at comparing between different footwear. Copyright © 2012 Elsevier B.V. All rights reserved.

Sexual selection and the evolution of brain size in primates.

Directory of Open Access Journals (Sweden)

Michael A Schillaci

Full Text Available Reproductive competition among males has long been considered a powerful force in the evolution of primates. The evolution of brain size and complexity in the Order Primates has been widely regarded as the hallmark of primate evolutionary history. Despite their importance to our understanding of primate evolution, the relationship between sexual selection and the evolutionary development of brain size is not well studied. The present research examines the evolutionary relationship between brain size and two components of primate sexual selection, sperm competition and male competition for mates. Results indicate that there is not a significant relationship between relative brain size and sperm competition as measured by relative testis size in primates, suggesting sperm competition has not played an important role in the evolution of brain size in the primate order. There is, however, a significant negative evolutionary relationship between relative brain size and the level of male competition for mates. The present study shows that the largest relative brain sizes among primate species are associated with monogamous mating systems, suggesting primate monogamy may require greater social acuity and abilities of deception.

Study on the production of kanvas shoes adhesive from natural rubber latex grafted with methyl methacrylate (NRL-g PMMA) copolymer

International Nuclear Information System (INIS)

Utama, Marga; Sudirman; Setyowati, Penny

2002-01-01

The optimation condition of radiation copolymerization of MMA into natural rubber latex at the doses of radiation : 5; 7.5 and 10 kGy with concentration of MMA 25; 50; 75; and 100 phr (Part Hundred Ratio of Rubber) expectially and optimazation condition of the adhesive process all the production of canvas shoes have been carried out. The properties of NRL-g-MMA and its rubber such as total solid contain, viscosity, pH, modulus, tensile, strenght, hardnes, elongation at break, and adhesive strenght for producting canvas shoes where evaluated. The at adhesive results show that NRL-g-MMA with the 75 phr of MMA and iradiation dose 5 kGy is adhesive will good stability during storage. The adhesive strenght of shoes its 16-18 N/6mm, more here than SNI 1-0172-1987 with the value 10N/6mm. Besic there is a tendency that adhesive strengt of product shoes at rome temperature (30-50 o C). stronger than at high temperature (100 o C)

Mortality of workers employed in shoe manufacturing: an update.

Science.gov (United States)

Lehman, Everett J; Hein, Misty J

2006-07-01

In the late 1970s, the National Institute for Occupational Safety and Health identified two shoe manufacturing facilities where workers experienced relatively "pure" exposures to toluene. A mortality study was conducted through December 31, 1982. An original study did not detect elevated leukemia mortality but did detect increased lung cancer mortality. The present study is an update of the mortality of the original cohort. The study cohort consisted of workers employed 1 month or more between 1940 and 1979 at two Ohio shoe manufacturing plants. Vital status was ascertained through December 31, 1999. Seven thousand eight hundred twenty eight workers, contributing 300,777 person years, were available for analysis. An excess of lung cancer deaths persisted with additional years of follow-up (SMR = 1.36, 95% confidence interval (CI) = 1.19-1.54). Trend tests did not indicate a positive trend between lung cancer risk and duration of employment. Mortality from leukemia was not significantly elevated in the updated analysis. Results indicate a possible association between lung cancer mortality and exposure to chronic, low-levels of organic solvents. Although the strength of this conclusion was weakened by the lack of increasing lung cancer risk in relation to duration of employment, other studies have supported this association. Published 2006 Wiley-Liss, Inc.

Social polyandry, parental investment, sexual selection, and evolution of reduced female gamete size.

Science.gov (United States)

Andersson, Malte

2004-01-01

Sexual selection in the form of sperm competition is a major explanation for small size of male gametes. Can sexual selection in polyandrous species with reversed sex roles also lead to reduced female gamete size? Comparative studies show that egg size in birds tends to decrease as a lineage evolves social polyandry. Here, a quantitative genetic model predicts that female scrambles over mates lead to evolution of reduced female gamete size. Increased female mating success drives the evolution of smaller eggs, which take less time to produce, until balanced by lowered offspring survival. Mean egg size is usually reduced and polyandry increased by increasing sex ratio (male bias) and maximum possible number of mates. Polyandry also increases with the asynchrony (variance) in female breeding start. Opportunity for sexual selection increases with the maximum number of mates but decreases with increasing sex ratio. It is well known that parental investment can affect sexual selection. The model suggests that the influence is mutual: owing to a coevolutionary feedback loop, sexual selection in females also shapes initial parental investment by reducing egg size. Feedback between sexual selection and parental investment may be common.

The distal shoe space maintainer chairside fabrication and clinical performance.

Science.gov (United States)

Brill, Warren A

2002-01-01

The chairside-fabricated distal shoe appliance, with a stainless steel crown as the retainer, is an efficacious and cost-effective appliance for guiding the unerupted permanent first molar into position after premature loss or extraction of the second primary molar. The fabrication technique is illustrated in this case report and data is presented on the success rate of the appliance.

Radioisotopic measurement methods for determining the wear railway brake shoe and its rim wearing effect

International Nuclear Information System (INIS)

Doman, P.

1979-01-01

Under operating conditions the wear of brake shoe was tested by a measuring method based on the principle of radioisotopic thickness measurement. It is characteristic to the sensitivity of the method that the wear caused by the fast braking of a train (speed: 100 km/h) as well as the uneven wear distribution were determinable. Surface activating methods assuring the periodic and continuous evaluation were also developed. A test was performed with galvanic surface activation under operating conditions to determine the rim wearing effect of the brake shoe. Apart from the operational tests a new method based on activated wear measurement was also developed. (author)

Can parallel use of different running shoes decrease running-related injury risk?

Science.gov (United States)

Malisoux, L; Ramesh, J; Mann, R; Seil, R; Urhausen, A; Theisen, D

2015-02-01

The aim of this study was to determine if runners who use concomitantly different pairs of running shoes are at a lower risk of running-related injury (RRI). Recreational runners (n = 264) participated in this 22-week prospective follow-up and reported all information about their running session characteristics, other sport participation and injuries on a dedicated Internet platform. A RRI was defined as a physical pain or complaint located at the lower limbs or lower back region, sustained during or as a result of running practice and impeding planned running activity for at least 1 day. One-third of the participants (n = 87) experienced at least one RRI during the observation period. The adjusted Cox regression analysis revealed that the parallel use of more than one pair of running shoes was a protective factor [hazard ratio (HR) = 0.614; 95% confidence interval (CI) = 0.389-0.969], while previous injury was a risk factor (HR = 1.722; 95%CI = 1.114-2.661). Additionally, increased mean session distance (km; HR = 0.795; 95%CI = 0.725-0.872) and increased weekly volume of other sports (h/week; HR = 0.848; 95%CI = 0.732-0.982) were associated with lower RRI risk. Multiple shoe use and participation in other sports are strategies potentially leading to a variation of the load applied to the musculoskeletal system. They could be advised to recreational runners to prevent RRI. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The Oblique Art of Shoes: Popular Culture, Aesthetic Pleasure, and the Humanities

NARCIS (Netherlands)

Lindner, C.

2015-01-01

This article addresses popular culture and the humanities. It uses shoes as an object of analysis to interrogate the place and function of aesthetic pleasure in critical thinking and cultural practice in the age of globalization and the neoliberal university. Tracking contemporary articulations of

Linking seasonal home range size with habitat selection and movement in a mountain ungulate.

Science.gov (United States)

Viana, Duarte S; Granados, José Enrique; Fandos, Paulino; Pérez, Jesús M; Cano-Manuel, Francisco Javier; Burón, Daniel; Fandos, Guillermo; Aguado, María Ángeles Párraga; Figuerola, Jordi; Soriguer, Ramón C

2018-01-01

Space use by animals is determined by the interplay between movement and the environment, and is thus mediated by habitat selection, biotic interactions and intrinsic factors of moving individuals. These processes ultimately determine home range size, but their relative contributions and dynamic nature remain less explored. We investigated the role of habitat selection, movement unrelated to habitat selection and intrinsic factors related to sex in driving space use and home range size in Iberian ibex, Capra pyrenaica . We used GPS collars to track ibex across the year in two different geographical areas of Sierra Nevada, Spain, and measured habitat variables related to forage and roost availability. By using integrated step selection analysis (iSSA), we show that habitat selection was important to explain space use by ibex. As a consequence, movement was constrained by habitat selection, as observed displacement rate was shorter than expected under null selection. Selection-independent movement, selection strength and resource availability were important drivers of seasonal home range size. Both displacement rate and directional persistence had a positive relationship with home range size while accounting for habitat selection, suggesting that individual characteristics and state may also affect home range size. Ibex living at higher altitudes, where resource availability shows stronger altitudinal gradients across the year, had larger home ranges. Home range size was larger in spring and autumn, when ibex ascend and descend back, and smaller in summer and winter, when resources are more stable. Therefore, home range size decreased with resource availability. Finally, males had larger home ranges than females, which might be explained by differences in body size and reproductive behaviour. Movement, selection strength, resource availability and intrinsic factors related to sex determined home range size of Iberian ibex. Our results highlight the need to integrate

Evidence of size-selective evolution in the fighting conch from prehistoric subsistence harvesting

OpenAIRE

O'Dea, Aaron; Shaffer, Marian Lynne; Doughty, Douglas R.; Wake, Thomas A.; Rodriguez, Felix A.

2014-01-01

Intensive size-selective harvesting can drive evolution of sexual maturity at smaller body size. Conversely, prehistoric, low-intensity subsistence harvesting is not considered an effective agent of size-selective evolution. Uniting archaeological, palaeontological and contemporary material, we show that size at sexual maturity in the edible conch Strombus pugilis declined significantly from pre-human (approx. 7 ka) to prehistoric times (approx. 1 ka) and again to the present day. Size at mat...

Shoe and field surface risk factors for acute lower extremity injuries among female youth soccer players

Science.gov (United States)

O'Kane, John W.; Gray, Kristen E.; Levy, Marni R.; Neradilek, Moni; Tencer, Allan F.; Polissar, Nayak L.; Schiff, Melissa A.

2015-01-01

Objective Describe acute lower extremity injuries and evaluate extrinsic risk factors in female youth soccer Design Nested case-control study Setting Youth soccer clubs in Washington State, USA. Participants Female soccer players (N= 351) ages 11 to 15 years randomly selected from 4 soccer clubs from which 83% of their players were enrolled with complete follow-up for 92% of players. Interventions Injured players were interviewed regarding injury, field surface, shoe type, and position. Uninjured controls, matched on game or practice session, were also interviewed. Main Outcome Measures The association between risk factors and acute lower extremity injury using logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CI). Results One hundred seventy-three acute lower extremity injuries occurred involving primarily the ankle (39.3%), knee (24.9%), and thigh (11.0%). Over half (52.9%) recovered within 1 week, while 30.2% lasted beyond 2 weeks. During practices, those injured were approximately 3-fold ( OR 2.83, 95% CI 1.49-5.31) more likely to play on grass than artificial turf and 2.4-fold (95% CI 1.03-5.96) more likely to wear cleats on grass than other shoe and surface combinations. During games injured players were 89% (95% CI 1.03-4.17) more likely to play defender compared to forward. Conclusions Half of the acute lower extremity injuries affected the ankle or knee. Grass surface and wearing cleats on grass increased training injuries. PMID:26327288

Modelling and simulation of size selectivity in diamond mesh trawl cod-ends

DEFF Research Database (Denmark)

Herrmann, Bent

of the fishing gear. The cod-end is the rearmost part of a trawl where catch accumulates and in which most of the size selection is known to take place. To date, the main method used to assess the selectivity of trawl cod-ends has been to run sea trials followed by statistical analysis of the obtained......Within many fisheries there is a widespread discard of fish. Furthermore, there are several fisheries where fish are caught before reaching the optimal size, leading to an adverse exploitation of the resources. One way to achieve a more optimal exploitation is to improve the size selectivity...

Tactile shoe inlays for high speed pressure monitoring

DEFF Research Database (Denmark)

Drimus, Alin; Mátéfi-Tempfli, Stefan

2015-01-01

This work describes the development of flexible tactile sensor shoe inlays for humanoid robots. Their design is based on a sandwich structure of flexible layers with a thin sheet of piezoresistive rubber as main transducer element. The layout and patterning of top and bottom electrodes give 1024...... pressure sensitive cells and the use of high speed electronics and multiplexing algorithms provides frame rates of 100 Hz. The sensors tolerate overloads while showing a consistent output. The developed prototypes show a high potential not only for robotics, but also for use in sensorised human prosthetics....

Customization of consumer goods: First steps to fully customizable fashionable ladies′ shoes

NARCIS (Netherlands)

Zande, M. van der; Bergmans, S.; Kamperman, N.; Vorst, B. van de

2009-01-01

The production of fashionable footwear has basically been the same for almost a century. It consists of combining elements of various materials together formed around a physical shape - the last - thereby making a product that fits around the foot - the shoe. This process requires different stages

Fundamentals of equine podiatry: balanced trimming and physiological shoeing

OpenAIRE

Estrada, Manuel

2014-01-01

The concepts of balanced trimming and physiological shoeing of the equine hoof as a way to prevent asymmetrical weight bearing and related orthopedic problems are discussed in this paper. Suggestions are given for the technical training of the personnel involved.  Considering the quantity and quality of the existing equine herd in Costa Rica, it is recommended to create a Farrier School as well as to coordinate the necessary efforts with other educational institutions related to the animal in...

Size-selective detection in integrated optical interferometric biosensors

NARCIS (Netherlands)

Mulder, Harmen K P; Ymeti, Aurel; Subramaniam, Vinod; Kanger, Johannes S

2012-01-01

We present a new size-selective detection method for integrated optical interferometric biosensors that can strongly enhance their performance. We demonstrate that by launching multiple wavelengths into a Young interferometer waveguide sensor it is feasible to derive refractive index changes from

A prospective study of floor surface, shoes, floor cleaning and slipping in US limited-service restaurant workers.

Science.gov (United States)

Verma, Santosh K; Chang, Wen Ruey; Courtney, Theodore K; Lombardi, David A; Huang, Yueng-Hsiang; Brennan, Melanye J; Mittleman, Murray A; Ware, James H; Perry, Melissa J

2011-04-01

Slips and falls are a leading cause of injury at work. Few studies, however, have systematically examined risk factors of slipping outside the laboratory environment. This study examined the association between floor surface characteristics, slip-resistant shoes, floor cleaning frequency and the risk of slipping in limited-service restaurant workers. 475 workers from 36 limited-service restaurants from three major chains in six states in the USA were recruited to participate in a prospective cohort study of workplace slipping. Kitchen floor surface roughness and coefficient of friction (COF) were measured in eight working areas and then averaged within each restaurant. The use of slip-resistant shoes was determined by examining the participant's shoes and noting the presence of a 'slip-resistant' marking on the sole. Restaurant managers reported the frequency of daily kitchen floor cleaning. Participants reported their slip experience and work hours weekly for up to 12 weeks. The survey materials were made available in three languages: English, Spanish and Portuguese. The associations between rate of slipping and risk factors were assessed using a multivariable negative binomial generalised estimating equation model. The mean of individual slipping rate varied among the restaurants from 0.02 to 2.49 slips per 40 work hours. After adjusting for age, gender, BMI, education, primary language, job tenure and restaurant chain, the use of slip-resistant shoes was associated with a 54% reduction in the reported rate of slipping (95% CI 37% to 64%), and the rate of slipping decreased by 21% (95% CI 5% to 34%) for each 0.1 increase in the mean kitchen COF. Increasing floor cleaning frequency was significantly associated with a decreasing rate of slipping when considered in isolation but not after statistical adjustment for other factors. These results provide support for the use of slip-resistant shoes and measures to increase COF as preventive interventions to reduce slips

Influence of different safety shoes on gait and plantar pressure: a standardized examination of workers in the automotive industry

OpenAIRE

Ochsmann, Elke; Noll, Ulrike; Ellegast, Rolf; Hermanns, Ingo; Kraus, Thomas

2016-01-01

Objective: Working conditions, such as walking and standing on hard surfaces, can increase the development of musculoskeletal complaints. At the interface between flooring and musculoskeletal system, safety shoes may play an important role in the well-being of employees. The aim of this study was to evaluate the effects of different safety shoes on gait and plantar pressure distributions on industrial flooring. Methods: Twenty automotive workers were individually fitted out with three differe...

Customization of consumer goods: First steps to fully customizable fashionable ladies′ shoes

NARCIS (Netherlands)

Zande, M. van der; Bergmans, S.; Kamperman, N.; Vorst, B. van de

2009-01-01

The production of fashionable footwear has basically been the same for almost a century. It consists of combining elements of various materials together around a physical shape – the last – and thereby making a product around the foot – the shoe. This process requires different stages in production,

Full Step Cycle Kinematic and Kinetic Comparison of Barefoot Walking and a Traditional Shoe Walking in Healthy Youth: Insights for Barefoot Technology

Directory of Open Access Journals (Sweden)

Yi Xu

2017-01-01

Full Text Available Objective. Barefoot technology shoes are becoming increasingly popular, yet modifications are still needed. The present study aims to gain valuable insights by comparing barefoot walking to neutral shoe walking in a healthy youth population. Methods. 28 healthy university students (22 females and 6 males were recruited to walk on a 10-meter walkway both barefoot and in neutral running shoes at their comfortable walking speed. Full step cycle kinematic and kinetic data were collected using an 8-camera motion capture system. Results. In the early stance phase, the knee extension moment (MK1, the first peak absorbed joint power at the knee joint (PK1, and the flexion angle of knee/dorsiflexion angle of the ankle were significantly reduced when walking in neutral running shoes. However, in the late stance, barefoot walking resulted in decreased hip joint flexion moment (MH2, second peak extension knee moment (MK3, hip flexors absorbed power (PH2, hip flexors generated power (PH3, second peak absorbed power by knee flexors (PK2, and second peak anterior-posterior component of joint force at the hip (APFH2, knee (APFK2, and ankle (APFA2. Conclusions. These results indicate that it should be cautious to discard conventional elements from future running shoe designs and rush to embrace the barefoot technology fashion.

Contamination Control of Freeze Shoe Coring System for Collection of Aquifer Sands

Science.gov (United States)

Homola, K.; van Geen, A.; Spivack, A. J.; Grzybowski, B.; Schlottenmier, D.

2017-12-01

We have developed and tested an original device, the freeze-shoe coring system, designed to recover undisturbed samples of water contained in sand-dominated aquifers. Aquifer sands are notoriously difficult to collect together with porewater from coincident depths, as high hydraulic permeability leads to water drainage and mixing during retrieval. Two existing corer designs were reconfigured to incorporate the freeze-shoe system; a Hydraulic Piston (HPC) and a Rotary (RC) Corer. Once deployed, liquid CO­2 contained in an interior tank is channeled to coils at the core head where it changes phase, rapidly cooling the deepest portion of the core. The resulting frozen core material impedes water loss during recovery. We conducted contamination tests to examine the integrity of cores retrieved during a March 2017 yard test deployment. Perfluorocarbon tracer (PFC) was added to the drill fluid and recovered cores were subsampled to capture the distribution of PFC throughout the core length and interior. Samples were collected from two HPC and one RC core and analyzed for PFC concentrations. The lowest porewater contamination, around 0.01% invasive fluid, occurs in the center of both HPC cores. The greatest contamination (up to 10%) occurs at the disturbed edges where core material contacts drill fluid. There was lower contamination in the core interior than top, bottom, and edges, as well as significantly lower contamination in HPC cores that those recovered with the RC. These results confirm that the freeze-shoe system, proposed for field test deployments in West Bengal, India, can successfully collect intact porewater and sediment material with minimal if any contamination from drill fluid.

Corridors of barchan dunes: Stability and size selection

DEFF Research Database (Denmark)

Hersen, P.; Andersen, Ken Haste; Elbelrhiti, H.

2004-01-01

state. Second, the propagation speed of dunes decreases with the size of the dune: this leads, through the collision process, to a coarsening of barchan fields. We show that these phenomena are not specific to the model, but result from general and robust mechanisms. The length scales needed...... for these instabilities to develop are derived and discussed. They turn out to be much smaller than the dune field length. As a conclusion, there should exist further, yet unknown, mechanisms regulating and selecting the size of dunes....

Biomimetic supercontainers for size-selective electrochemical sensing of molecular ions

Science.gov (United States)

Netzer, Nathan L.; Must, Indrek; Qiao, Yupu; Zhang, Shi-Li; Wang, Zhenqiang; Zhang, Zhen

2017-04-01

New ionophores are essential for advancing the art of selective ion sensing. Metal-organic supercontainers (MOSCs), a new family of biomimetic coordination capsules designed using sulfonylcalix[4]arenes as container precursors, are known for their tunable molecular recognition capabilities towards an array of guests. Herein, we demonstrate the use of MOSCs as a new class of size-selective ionophores dedicated to electrochemical sensing of molecular ions. Specifically, a MOSC molecule with its cavities matching the size of methylene blue (MB+), a versatile organic molecule used for bio-recognition, was incorporated into a polymeric mixed-matrix membrane and used as an ion-selective electrode. This MOSC-incorporated electrode showed a near-Nernstian potentiometric response to MB+ in the nano- to micro-molar range. The exceptional size-selectivity was also evident through contrast studies. To demonstrate the practical utility of our approach, a simulated wastewater experiment was conducted using water from the Fyris River (Sweden). It not only showed a near-Nernstian response to MB+ but also revealed a possible method for potentiometric titration of the redox indicator. Our study thus represents a new paradigm for the rational design of ionophores that can rapidly and precisely monitor molecular ions relevant to environmental, biomedical, and other related areas.

Pinning of size-selected gold and nickel nanoclusters on graphite

NARCIS (Netherlands)

Di Vece, M.|info:eu-repo/dai/nl/248753355; Paloma, S.; Palmer, R.E.

2005-01-01

Size-selected gold and nickel nanoclusters are of interest from an electronic, catalytic, and biological point of view. These applications require the deposition of the clusters on a surface, and a key challenge is to retain the cluster size. Here controlled energy impact is used to immobilize the

The Influence of Outdoor Shoe Sole Stiffness on the Metatarsophalangeal Joint Kinematics When Walking and Running in Different Conditions

Directory of Open Access Journals (Sweden)

Paolo Mistretta

2018-02-01

Full Text Available Understanding the action of the metatarsophalangeal joint (MTP is fundamental to improving the design process of a new outdoor shoe. Coming from the stated consideration, the aim of this research is to study the influence of shoe sole stiffness and terrain slope on the MTP joint angle of subjects walking in different conditions. To pursue this intent, different data collection sessions have been carried out in-vitro and in-vivo, indoor and outdoor. Two different approaches have been used to collect gait kinematics: an IMU (Inertial Measurement Unit based system for the first campaign of tests, and a 2D video analysis for the second. Major findings showed a linear correlation between shoe sole stiffness and peak MTP joint angle during gait, as well as consistency in the value of the slope of the linear regression curves corresponding to the different conditions examined.

U-Mo Alloy Powder Obtained Through Selective Hydriding. Particle Size Control

International Nuclear Information System (INIS)

Balart, S.N.; Bruzzoni, P.; Granovsky, M.S.

2002-01-01

Hydride-dehydride methods to obtain U-Mo alloy powder for high-density fuel elements have been successfully tested by different authors. One of these methods is the selective hydriding of the α phase (HSα). In the HSα method, a key step is the partial decomposition of the γ phase (retained by quenching) to α phase and an enriched γ phase or U 2 Mo. This transformation starts mainly at grain boundaries. Subsequent hydrogenation of this material leads to selective hydriding of the α phase, embrittlement and intergranular fracture. According to this picture, the particle size of the final product should be related to the γ grain size of the starting alloy. The feasibility of controlling the particle size of the product by changing the γ grain size of the starting alloy is currently investigated. In this work an U-7 wt% Mo alloy was subjected to various heat treatments in order to obtain different grain sizes. The results on the powder particle size distribution after applying the HSα method to these samples show that there is a strong correlation between the original γ grain size and the particle size distribution of the powder. (author)

Magnetron sputtering cluster apparatus for formation and deposition of size-selected metal nanoparticles

DEFF Research Database (Denmark)

Hanif, Muhammad; Popok, Vladimir

2015-01-01

selection is achieved using an electrostatic quadrupole mass selector. The deposited silver clusters are studied using atomic force microscopy. The height distributions show typical relative standard size deviation of 9-13% for given sizes in the range between 5-23 nm. Thus, the apparatus demonstrates good...... capability in formation of supported size-selected metal nanoparticles with controllable coverage for various practical applications....

Aerosol size characteristics in selected working areas

International Nuclear Information System (INIS)

Ahmed, K.

1984-05-01

This report presents the work done to study the aerosol activity size distributions and their respirable fractions in some selected areas of the Juelich Nuclear Research Center. Anderson cascade impactors were used to find the aerodynamic size ranges of the airborne particles for subsequent analysis of activity associated with each size group. The aerosols were found to follow in general log-normal distributions in the hot cells with values of AMAD between 5 and 10 μm. Measurements in the AVR containment and decontamination laboratory in Uranit GmbH showed deviations from log-normal distribution. In the waste press area the distribution is sometimes log-normal and sometimes not, depending upon the origin of waste. The values of AMAD are in the range of 2 to 4 μm in these areas. The respirable fractions were calculated using ACGIH definition for respirable dust to be < 25% in hot cells and < 60% in other areas. Pulmonary depositions according to ICRP model were < 10% and < 15% respectively. (orig./HP)

Breathing shoes and complementarities: strategic innovation in a mature industry

OpenAIRE

A. Camuffo; A. Furlan; P. Romano; A. Vinelli

2008-01-01

This paper tells the story of Geox, an Italian footwear manufacturer that, in less than a decade, has become one of the world's largest shoe manufacturers. Applying the related notions of complementarity and performance landscape to study strategic positioning in the footwear industry, we show that, though grounded on product innovation (the original Geox breathes® patented system which allows ventilation in waterproof rubber sole), Geox's competitive advantage has not grown out of operationa...

In-shoe plantar tri-axial stress profiles during maximum-effort cutting maneuvers.

Science.gov (United States)

Cong, Yan; Lam, Wing Kai; Cheung, Jason Tak-Man; Zhang, Ming

2014-12-18

Soft tissue injuries, such as anterior cruciate ligament rupture, ankle sprain and foot skin problems, frequently occur during cutting maneuvers. These injuries are often regarded as associated with abnormal joint torque and interfacial friction caused by excessive external and in-shoe shear forces. This study simultaneously investigated the dynamic in-shoe localized plantar pressure and shear stress during lateral shuffling and 45° sidestep cutting maneuvers. Tri-axial force transducers were affixed at the first and second metatarsal heads, lateral forefoot, and heel regions in the midsole of a basketball shoe. Seventeen basketball players executed both cutting maneuvers with maximum efforts. Lateral shuffling cutting had a larger mediolateral braking force than 45° sidestep cutting. This large braking force was concentrated at the first metatarsal head, as indicated by its maximum medial shear stress (312.2 ± 157.0 kPa). During propulsion phase, peak shear stress occurred at the second metatarsal head (271.3 ± 124.3 kPa). Compared with lateral shuffling cutting, 45° sidestep cutting produced larger peak propulsion shear stress (463.0 ± 272.6 kPa) but smaller peak braking shear stress (184.8 ± 181.7 kPa), of which both were found at the first metatarsal head. During both cutting maneuvers, maximum medial and posterior shear stress occurred at the first metatarsal head, whereas maximum pressure occurred at the second metatarsal head. The first and second metatarsal heads sustained relatively high pressure and shear stress and were expected to be susceptible to plantar tissue discomfort or injury. Due to different stress distribution, distinct pressure and shear cushioning mechanisms in basketball footwear might be considered over different foot regions. Copyright © 2014 Elsevier Ltd. All rights reserved.

Size-Selective Oxidation of Aldehydes with Zeolite Encapsulated Gold Nanoparticles

DEFF Research Database (Denmark)

Højholt, Karen Thrane; Laursen, Anders Bo; Kegnæs, Søren

2011-01-01

Here, we report a synthesis and catalytic study of hybrid materials comprised of 1–3 nm sinter-stable Au nanoparticles in MFI-type zeolites. An optional post-treatment in aqua regia effectively remove Au from the external surfaces. The size-selective aerobic aldehyde oxidation verifies that the a......Here, we report a synthesis and catalytic study of hybrid materials comprised of 1–3 nm sinter-stable Au nanoparticles in MFI-type zeolites. An optional post-treatment in aqua regia effectively remove Au from the external surfaces. The size-selective aerobic aldehyde oxidation verifies...... that the active Au is accessible only through the zeolite micropores....

The effect of shoe design and lateral wedges on knee load and neuromuscular control in healthy subjects during walking

DEFF Research Database (Denmark)

Mølgaard, Carsten; Kersting, Uwe G.

2014-01-01

The increasing number of patients with developing osteoarthritis is accompanied by a growing scientific interest in non-operative early treatment strategies. It is generally believed that laterally wedged insoles can change the distribution of knee loading. However, the importance of footwear...... wedging is effective regardless of shoe design. Differences between the three neutral walking conditions underline the importance of footwear choice in individuals. It is safe to apply lateral wedges without jeopardising muscular control during walking regardless of shoe type. Possible effects of altering...

Identification of virtual grounds using virtual reality haptic shoes and sound synthesis

DEFF Research Database (Denmark)

Serafin, Stefania; Turchet, Luca; Nordahl, Rolf

2010-01-01

We describe a system which simulates in real-time the auditory and haptic sensation of walking on different surfaces. The system is based on physical models, that drive both the haptic and audio synthesizers, and a pair of shoes enhanced with sensors and actuators. In a discrimination experiment,...

An Overview of Smart Shoes in the Internet of Health Things: Gait and Mobility Assessment in Health Promotion and Disease Monitoring

Directory of Open Access Journals (Sweden)

Bjoern M. Eskofier

2017-09-01

Full Text Available New smart technologies and the internet of things increasingly play a key role in healthcare and wellness, contributing to the development of novel healthcare concepts. These technologies enable a comprehensive view of an individual’s movement and mobility, potentially supporting healthy living as well as complementing medical diagnostics and the monitoring of therapeutic outcomes. This overview article specifically addresses smart shoes, which are becoming one such smart technology within the future internet of health things, since the ability to walk defines large aspects of quality of life in a wide range of health and disease conditions. Smart shoes offer the possibility to support prevention, diagnostic work-up, therapeutic decisions, and individual disease monitoring with a continuous assessment of gait and mobility. This overview article provides the technological as well as medical aspects of smart shoes within this rising area of digital health applications, and is designed especially for the novel reader in this specific field. It also stresses the need for closer interdisciplinary interactions between technological and medical experts to bridge the gap between research and practice. Smart shoes can be envisioned to serve as pervasive wearable computing systems that enable innovative solutions and services for the promotion of healthy living and the transformation of health care.

Estimation of the ancestral effective population sizes of African great apes under different selection regimes.

Science.gov (United States)

Schrago, Carlos G

2014-08-01

Reliable estimates of ancestral effective population sizes are necessary to unveil the population-level phenomena that shaped the phylogeny and molecular evolution of the African great apes. Although several methods have previously been applied to infer ancestral effective population sizes, an analysis of the influence of the selective regime on the estimates of ancestral demography has not been thoroughly conducted. In this study, three independent data sets under different selective regimes were used were composed to tackle this issue. The results showed that selection had a significant impact on the estimates of ancestral effective population sizes of the African great apes. The inference of the ancestral demography of African great apes was affected by the selection regime. The effects, however, were not homogeneous along the ancestral populations of great apes. The effective population size of the ancestor of humans and chimpanzees was more impacted by the selection regime when compared to the same parameter in the ancestor of humans, chimpanzees and gorillas. Because the selection regime influenced the estimates of ancestral effective population size, it is reasonable to assume that a portion of the discrepancy found in previous studies that inferred the ancestral effective population size may be attributable to the differential action of selection on the genes sampled.

Escape windows to improve the size selectivity in the Baltic cod trawl fishery

DEFF Research Database (Denmark)

Madsen, Niels; Holst, René; Foldager, L.

2002-01-01

A rapid decrease of the stock of Baltic cod (Gadus morhua) has provided the incentive to improve the size selectivity in the trawl fishery. Use of escape windows is permitted in the legislation to give means of improving the size selectivity of cod as an alternative to a traditional standard codend....... The history of the use of escape windows in the Baltic Sea cod fishery is reviewed. The present escape windows do not function optimally. The objective of this new experiment was to compare an improved design of escape window, which is placed in the upper panel, with that of standard codend. Three standard...... of the codend selectivity was formulated to analyse the results and determine the effects of codend type, mesh size and other recorded variables. L50 and SR increased significantly with the mesh size. L50 was significantly increased and SR significantly reduced for a window codend with the same window mesh size...

The Strength and Drivers of Bird-Mediated Selection on Fruit Crop Size: A Meta-Analysis

Directory of Open Access Journals (Sweden)

Facundo X. Palacio

2018-02-01

Full Text Available In seed-dispersal mutualisms, the number of fruit a plant displays is a key trait, as it acts as a signal for seed dispersers that entails fruit removal and exportation of reproductive units (fruit crop size hypothesis. Although this hypothesis has gained general acceptance, forces driving the shape and strength of natural selection exerted by birds on fruit crop size remains an unresolved matter. Here, we propose that ecological filters promoting high functional equivalence of interacting partners (similar functional roles translate into similar selection pressures on fruit crop size, enhancing selection strength on this trait. We performed a meta-analysis on 50 seed-dispersal systems to test the hypothesis that frugivorous birds exert positive selection pressure on fruit crop size, and to assess whether different factors expected to act as filters (fruit diameter, fruit type, fruiting season length, bird functional groups, and latitude influence phenotypic selection regimes on this trait. Birds promote larger fruit crop sizes as a general pattern in nature. Short fruiting seasons and a high proportion of species belonging to the same functional group showed higher selection strength on fruit crop size. Also, selection strength on fruit crop size increased for large-fruited species and toward the tropics. Our results support the hypothesis that fruit crop size represents a conspicuous signal advertising the amount of reward to visually driven interacting partners, and that both plant and bird traits, as well as environmental factors, drive selection strength on fruit display traits. Furthermore, our results suggest that the relationship among forces impinged by phenology and frugivore functional roles may be key to understand their evolutionary stability.

Sexual selection on male size drives the evolution of male-biased sexual size dimorphism via the prolongation of male development.

Science.gov (United States)

Rohner, Patrick T; Blanckenhorn, Wolf U; Puniamoorthy, Nalini

2016-06-01

Sexual size dimorphism (SSD) arises when the net effects of natural and sexual selection on body size differ between the sexes. Quantitative SSD variation between taxa is common, but directional intraspecific SSD reversals are rare. We combined micro- and macroevolutionary approaches to study geographic SSD variation in closely related black scavenger flies. Common garden experiments revealed stark intra- and interspecific variation: Sepsis biflexuosa is monomorphic across the Holarctic, while S. cynipsea (only in Europe) consistently exhibits female-biased SSD. Interestingly, S. neocynipsea displays contrasting SSD in Europe (females larger) and North America (males larger), a pattern opposite to the geographic reversal in SSD of S. punctum documented in a previous study. In accordance with the differential equilibrium model for the evolution of SSD, the intensity of sexual selection on male size varied between continents (weaker in Europe), whereas fecundity selection on female body size did not. Subsequent comparative analyses of 49 taxa documented at least six independent origins of male-biased SSD in Sepsidae, which is likely caused by sexual selection on male size and mediated by bimaturism. Therefore, reversals in SSD and the associated changes in larval development might be much more common and rapid and less constrained than currently assumed. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

Assessment of asymmetric leg loading before and after total hip arthroplasty using instrumented shoes

NARCIS (Netherlands)

Martínez-Ramírez, Alicia; Weenk, D.; Lecumberri, Pablo; Verdonschot, Nicolaas Jacobus Joseph; Pakvis, Dean; Veltink, Petrus H.

2013-01-01

The stance time and the average vertical ground reaction force measured with the instrumented shoes during walking, and their symmetry index, showed significant differences before and after total hip arthroplasty. However, the data obtained with the sit to stand test did not reveal this improvement

Natural selection and inheritance of breeding time and clutch size in the collared flycatcher.

Science.gov (United States)

Sheldon, B C; Kruuk, L E B; Merilä, J

2003-02-01

Many characteristics of organisms in free-living populations appear to be under directional selection, possess additive genetic variance, and yet show no evolutionary response to selection. Avian breeding time and clutch size are often-cited examples of such characters. We report analyses of inheritance of, and selection on, these traits in a long-term study of a wild population of the collared flycatcher Ficedula albicollis. We used mixed model analysis with REML estimation ("animal models") to make full use of the information in complex multigenerational pedigrees. Heritability of laying date, but not clutch size, was lower than that estimated previously using parent-offspring regressions, although for both traits there was evidence of substantial additive genetic variance (h2 = 0.19 and 0.29, respectively). Laying date and clutch size were negatively genetically correlated (rA = -0.41 +/- 0.09), implying that selection on one of the traits would cause a correlated response in the other, but there was little evidence to suggest that evolution of either trait would be constrained by correlations with other phenotypic characters. Analysis of selection on these traits in females revealed consistent strong directional fecundity selection for earlier breeding at the level of the phenotype (beta = -0.28 +/- 0.03), but little evidence for stabilising selection on breeding time. We found no evidence that clutch size was independently under selection. Analysis of fecundity selection on breeding values for laying date, estimated from an animal model, indicated that selection acts directly on additive genetic variance underlying breeding time (beta = -0.20 +/- 0.04), but not on clutch size (beta = 0.03 +/- 0.05). In contrast, selection on laying date via adult female survival fluctuated in sign between years, and was opposite in sign for selection on phenotypes (negative) and breeding values (positive). Our data thus suggest that any evolutionary response to selection on

Synthesis and magnetic properties of size-selected CoPt nanoparticles

International Nuclear Information System (INIS)

Tournus, F.; Blanc, N.; Tamion, A.; Hillenkamp, M.; Dupuis, V.

2011-01-01

CoPt nanoparticles are widely studied, in particular for their potentially very high magnetic anisotropy. However, their magnetic properties can differ from the bulk ones and they are expected to vary with the particle size. In this paper, we report the synthesis and characterization of well-defined CoPt nanoparticle samples produced in ultrahigh vacuum conditions following a physical route: the mass-selected low energy cluster beam deposition technique. This approach relies on an electrostatic deviation of ionized clusters which allows us to easily adjust the particle size, independently from the deposited equivalent thickness (i.e. the surface or volume particle density in a sample). Diluted samples made of CoPt particles, with different diameters, embedded in amorphous carbon are studied by transmission electron microscopy and superconducting interference device magnetometry, which gives access to the magnetic anisotropy energy distribution. We then compare the magnetic properties of two different particle sizes. The results are found to be consistent with an anisotropy constant (including its distribution) which does not evolve with the particle size in the range considered. - Highlights: → Samples of mass-selected CoPt nanoparticles are synthesized by an original physical method. → The magnetic properties of two different particle sizes are compared. → The anisotropy constant (including its dispersion) does not evolve in the range considered. → These results illustrate some invariance properties of ZFC curves.

The effect of shoe type on static and dynamic balance during treadmill walking in young healthy women.

Science.gov (United States)

Kim, Mi-Kyoung; Kong, Byung-Sun; Yoo, Kyung-Tae

2017-09-01

[Purpose] The purpose of this study was to analyze the effect of various shoes on the static and dynamic balance of young women in their 20s. [Subjects and Methods] The subjects of the study were 15 healthy young women and repeated measured design. The subjects walked on the treadmill at a speed of 4 km/h for 30 minutes wearing three types of shoes: sneaker, rain boots, and combat boots. Balance was measured by a Romberg test and a limits of stability test. One-way ANOVA was used for statistical analysis. [Results] As the results of the Romberg test, the main effect of time was shown in the EO-COG area, EO-COG length, and EO-COG velocity. As the results of the limits of stability test, the main effects of time in LT, RT, FW, and total. There were significant differences in the LT in the sneaker group, the rain boots group, and the LT and RT in the combat boots group between the pre- and post-test. [Conclusion] The characteristics of shoes such as the materials, hardness, and thickness of the soles, the coefficient of friction of the outsoles, and the collar height affected the static and dynamic balance.

Study on friction behaviour of brake shoe materials for mining hoist

Science.gov (United States)

Ungureanu, M.; Ungureanu, N. S.; Crăciun, I.

2017-02-01

The friction coefficient in the brake linkages has an important influence on the braking efficiency and safety of machines. The paper presents a method for the study of the friction coefficient of the friction couple brake shoe-drum for mining hoist. In this context, it is interesting to define the friction coefficient, not just according to the materials in contact, but according to the entire ensemble of tribological factors of the friction couple.

A New Error Analysis and Accuracy Synthesis Method for Shoe Last Machine

Directory of Open Access Journals (Sweden)

Bian Xiangjuan

2014-05-01

Full Text Available In order to improve the manufacturing precision of the shoe last machine, a new error-computing model has been put forward to. At first, Based on the special topological structure of the shoe last machine and multi-rigid body system theory, a spatial error-calculating model of the system was built; Then, the law of error distributing in the whole work space was discussed, and the maximum error position of the system was found; At last, The sensitivities of error parameters were analyzed at the maximum position and the accuracy synthesis was conducted by using Monte Carlo method. Considering the error sensitivities analysis, the accuracy of the main parts was distributed. Results show that the probability of the maximal volume error less than 0.05 mm of the new scheme was improved from 0.6592 to 0.7021 than the probability of the old scheme, the precision of the system was improved obviously, the model can be used for the error analysis and accuracy synthesis of the complex multi- embranchment motion chain system, and to improve the system precision of manufacturing.

Epidemiology of High-Heel Shoe Injuries in U.S. Women: 2002 to 2012.

Science.gov (United States)

Moore, Justin Xavier; Lambert, Brice; Jenkins, Gabrielle P; McGwin, Gerald

2015-01-01

The purpose of the present study was to investigate the epidemiology of high-heel-related injuries among a nationally representative population of women in the United States and to analyze the demographic differences within this group. The data used in the present study were collected from the Consumer Product Safety Commission's National Electronic Injury Surveillance System. A total of 3294 injuries, representing an estimated 123,355 high-heel-related injuries, were treated in emergency departments within the United States from 2002 to 2012. The overall rate of high-heel-related injuries for the study was 7.32 per 100,000 females (95% confidence interval 7.08 to 7.56). The injury rate was greatest for young adult females, with the greatest rates observed for those aged 20 to 29 years (18.38 per 100,000 females) and those aged 30 to 39 years (11.07 per 100,000 females). The results from the present study suggest that high-heel-related injuries have nearly doubled during the 11-year period from 2002 to 2012. Injuries from high heels are differential by body region, with most injuries occurring as sprains and strains to the foot and ankle. Although high heels might be stylish, from a health standpoint, it could be worthwhile for females and those interested in wearing high heels to understand the risks of wearing high-heeled shoes and the potential harm that precarious activities in high-heeled shoes can cause. The results of the present study can be used in the development of a prospective cohort study to investigate the risk of injury from high-heeled shoes, accounting for the exposure time and studying differences in demographics (e.g., age and race). Copyright © 2015 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

The influence of cadence and power output on force application and in-shoe pressure distribution during cycling by competitive and recreational cyclists.

Science.gov (United States)

Sanderson, D J; Hennig, E M; Black, A H

2000-03-01

The aim of this study was to determine the response of cyclists to manipulations of cadence and power output in terms of force application and plantar pressure distribution. Two groups of cyclists, 17 recreational and 12 competitive, rode at three nominal cadences (60, 80, 100 rev x min(-1)) and four power outputs (100, 200, 300, 400 W) while simultaneous force and in-shoe pressure data were collected. Two piezoelectric triaxial force transducers mounted in the right pedal measured components of the pedal force and orientation, and a discrete transducer system with 12 transducers recorded the in-shoe pressures. Force application was characterized by calculating peak resultant and peak effective pedal forces and positive and negative impulses. In-shoe pressures were analysed as peak pressures and as the percent relative load. The force data showed no significant group effect but there was a cadence and power main effect. The impulse data showed a significant three-way interaction. Increased cadence resulted in a decreased positive impulse, while increased power output resulted in an increased impulse. The competitive group produced less positive impulse but the difference became less at higher cadences. Few between-group differences were found in pressure, notable only in the pressure under the first metatarsal region. This showed a consistent pattern of in-shoe pressure distribution, where the primary loading structures were the first metatarsal and hallux. There was no indication that pressure at specific sites influenced the pedal force application. The absence of group differences indicated that pressure distribution was not the result of training, but reflected the intrinsic relationship between the foot, the shoe and the pedal.

The Effect of Shoe Sole Tread Groove Depth on the Gait Parameters during Walking on Dry and Slippery Surface

Directory of Open Access Journals (Sweden)

M Ziaei

2012-12-01

Full Text Available Background: Prevention of slipping accidents requires provision of adequate friction through the use of suitable combinations of footwear and underfoot surfaces. Shoe sole tread groove is one of the important factors on friction coefficient during walking. Objective: To measure the effect of different shoe sole tread groove depths and different surfaces on the required quotient of friction (Q, heel strike velocity and occurrence time of ground reaction forces (GRF in stance phase during walking on slippery and dry surfaces. Methods: In this semi-experimental study, 22 healthy men were studied under different conditions. The studied independent variables were shoe groove depths (included 1, 2.5 and 5 mm and type of walking surface (dry and slippery. Biomechanical gait analysis was carried out with 396 single steps. Data were collected by motion analysis system and two force platform. Results: The occurrence time of GRF was significantly faster on dry surface than slippery surface (p<0.01. Q was significantly lower on slippery surface and with groove depths of 1 and 2.5 mm. The highest value of Q was observed with the deepest groove depth of 5 mm. Heel strike velocity did not differ significantly in the 6 conditions tested. Conclusion: Tread groove depth is a significant factor affecting the Q at the shoes-surface interface on dry and slippery floors. It seems that deeper groove is more appropriate for maintaining the stability during walking. The walking surface affects the occurrence time of GRF; the force components occur sooner on the dry than slippery surface.

Study on Walking Training System using High-Performance Shoes constructed with Rubber Elements

International Nuclear Information System (INIS)

Hayakawa, Y; Kawanaka, S; Doi, S; Kanezaki, K

2016-01-01

The number of accidental falls has been increasing among the elderly as society has aged. The main factor is a deteriorating center of balance due to declining physical performance. Another major factor is that the elderly tend to have bowlegged walking and their center of gravity position of the body tend to swing from side to side during walking. To find ways to counteract falls among the elderly, we developed walking training system to treat the gap in the center of balance. We also designed High-Performance Shoes that showed the status of a person's balance while walking. We also produced walk assistance from the insole in which insole stiffness corresponded to human sole distribution could be changed to correct the person's walking status. We constructed our High- Performances Shoes to detect pressure distribution during walking. Comparing normal sole distribution patterns and corrected ones, we confirmed that our assistance system helped change the user's posture, thereby reducing falls among the elderly. (paper)

Sample size estimation and sampling techniques for selecting a representative sample

Directory of Open Access Journals (Sweden)

Aamir Omair

2014-01-01

Full Text Available Introduction: The purpose of this article is to provide a general understanding of the concepts of sampling as applied to health-related research. Sample Size Estimation: It is important to select a representative sample in quantitative research in order to be able to generalize the results to the target population. The sample should be of the required sample size and must be selected using an appropriate probability sampling technique. There are many hidden biases which can adversely affect the outcome of the study. Important factors to consider for estimating the sample size include the size of the study population, confidence level, expected proportion of the outcome variable (for categorical variables/standard deviation of the outcome variable (for numerical variables, and the required precision (margin of accuracy from the study. The more the precision required, the greater is the required sample size. Sampling Techniques: The probability sampling techniques applied for health related research include simple random sampling, systematic random sampling, stratified random sampling, cluster sampling, and multistage sampling. These are more recommended than the nonprobability sampling techniques, because the results of the study can be generalized to the target population.

The knee adduction moment measured with an instrumented force shoe in patients with knee osteoarthritis

NARCIS (Netherlands)

van den Noort, J.C.; van den Noort, Josien C.; van der Esch, Martin; Steultjens, Martijn P.M.; Dekker, Joost; Schepers, H. Martin; Veltink, Petrus H.; Harlaar, Jaap

2012-01-01

The external knee adduction moment (KAdM) during gait is an important parameter in patients with knee osteoarthritis (OA). KAdM measurement is currently restricted to instruments only available in gait laboratories. However, ambulatory movement analysis technology, including instrumented force shoes

Selective determination of dopamine using quantum-sized gold nanoparticles protected with charge selective ligands

Science.gov (United States)

Kwak, Kyuju; Kumar, S. Senthil; Lee, Dongil

2012-06-01

We report here the selective determination of dopamine (DA) using quantum-sized gold nanoparticles coated with charge selective ligands. Glutathione protected gold nanoparticles (GS-Au25) were synthesized and immobilized into a sol-gel matrix via thiol linkers. The GS-Au25 modified sol-gel electrode was found to show excellent electrocatalytic activity towards the oxidation of DA but no activity towards the oxidation of ascorbic acid. The role of electrostatic charge in the selective electrocatalytic activity of GS-Au25 was verified by voltammetry of redox markers carrying opposite charges. The pH dependent sensitivity for the determination of DA further confirmed the charge screening effect of GS-Au25. Mechanistic investigation revealed that the selectivity is attained by the selective formation of an electrostatic complex between the negatively charged GS-Au25 and DA cation. The GS-Au25 modified sol-gel electrode also showed excellent selectivity for DA in the presence of an interferent, ascorbic acid.We report here the selective determination of dopamine (DA) using quantum-sized gold nanoparticles coated with charge selective ligands. Glutathione protected gold nanoparticles (GS-Au25) were synthesized and immobilized into a sol-gel matrix via thiol linkers. The GS-Au25 modified sol-gel electrode was found to show excellent electrocatalytic activity towards the oxidation of DA but no activity towards the oxidation of ascorbic acid. The role of electrostatic charge in the selective electrocatalytic activity of GS-Au25 was verified by voltammetry of redox markers carrying opposite charges. The pH dependent sensitivity for the determination of DA further confirmed the charge screening effect of GS-Au25. Mechanistic investigation revealed that the selectivity is attained by the selective formation of an electrostatic complex between the negatively charged GS-Au25 and DA cation. The GS-Au25 modified sol-gel electrode also showed excellent selectivity for DA in the

Statistical experiments using the multiple regression research for prediction of proper hardness in areas of phosphorus cast-iron brake shoes manufacturing

Science.gov (United States)

Kiss, I.; Cioată, V. G.; Ratiu, S. A.; Rackov, M.; Penčić, M.

2018-01-01

Multivariate research is important in areas of cast-iron brake shoes manufacturing, because many variables interact with each other simultaneously. This article focuses on expressing the multiple linear regression model related to the hardness assurance by the chemical composition of the phosphorous cast irons destined to the brake shoes, having in view that the regression coefficients will illustrate the unrelated contributions of each independent variable towards predicting the dependent variable. In order to settle the multiple correlations between the hardness of the cast-iron brake shoes, and their chemical compositions several regression equations has been proposed. Is searched a mathematical solution which can determine the optimum chemical composition for the hardness desirable values. Starting from the above-mentioned affirmations two new statistical experiments are effectuated related to the values of Phosphorus [P], Manganese [Mn] and Silicon [Si]. Therefore, the regression equations, which describe the mathematical dependency between the above-mentioned elements and the hardness, are determined. As result, several correlation charts will be revealed.

Injury Reduction Effectiveness of Prescribing Running Shoes Based on Foot Shape in Air Force Basic Military Training

National Research Council Canada - National Science Library

Knapik, Joseph J; Brosch, Lorie C; Venuto, Margaret; Swedler, David I; Bullock, Steven H; Gaines, Lorraine S; Murphy, Ryan J; Canada, Sara E; Hoedebecke, Edward L; Tobler, Steven K

2008-01-01

In response to a request from the Military Training Task Force of the Defense Safety Oversight Council this study examined whether prescribing running shoes based on the shape of the plantar surface...

Effectiveness and safety of a nonremovable fiberglass off-bearing cast versus a therapeutic shoe in the treatment of neuropathic foot ulcers: a randomized study.

Science.gov (United States)

Caravaggi, C; Faglia, E; De Giglio, R; Mantero, M; Quarantiello, A; Sommariva, E; Gino, M; Pritelli, C; Morabito, A

2000-12-01

To evaluate and compare the rate of reduction of the surface area of neuropathic plantar ulcers in diabetic patients treated with nonremovable rigidity-differentiated fiberglass off-bearing casts or a cloth shoe with a rigid sole with unloading alkaform insoles. The secondary aim was to evaluate the side effects and degree of patient acceptance of treatment. Fifty diabetic patients with neuropathic plantar ulcers were consecutively enrolled and randomized to one of two treatment groups. Of the 50 patients, 24 were treated with a specialized cloth shoe with a rigid sole and an unloading alkaform insole (shoe group), and 26 patients were treated with a nonremovable off-bearing fiberglass cast (cast group). All patients in both study groups returned to the clinic for weekly control visits. Their ulcers were treated with a standard dressing. Tracings of the ulcer area using a transparent dressing were performed on the day of entry to the study and after 30 days of treatment. The presence of new ulcerations caused by the use of the pressure-relief apparatus was recorded. Patient acceptance of the treatment was measured using a visual analog scale. At the end of the treatment period, an 8.3% increase of the ulcer area was observed in two patients in the shoe group, whereas in the cast group, no patient presented an increase. The reduction of the ulcer area was statistically more rapid in the cast group (Mann-Whitney test, P = 0.0004). Furthermore, the number of ulcers completely healed at the 30-day time point was 13 (50%) in the cast group and 5 (20.8%) in the shoe group (P = 0.03). In both groups, no side effects were recorded. The average score +/- SD of patient acceptance was 91.15 +/- 9.9 in the shoe group and 88.33 +/- 17.3 (NS) in the cast group. Our study has shown a significant difference in the speed of the reduction of neuropathic plantar ulcers treated with a fiberglass cast compared with a specialized cloth shoe. The use of fiberglass material with variable

The effects of high custom made shoes on gait characteristics and patient satisfaction in hemiplegic gait

NARCIS (Netherlands)

Eckhardt, Martine M; Mulder, Mascha C Borgerhoff; Horemans, Herwin L; van der Woude, Lucas; Ribbers, Gerard M

2011-01-01

OBJECTIVE: To determine the effects of a temporary high custom made orthopaedic shoe on functional mobility, walking speed, and gait characteristics in hemiplegic stroke patients. In addition, interference of attentional demands and patient satisfaction were studied. DESIGN: Clinical experimental

The effects of high custom made shoes on gait characteristics and patient satisfaction in hemiplegic gait

NARCIS (Netherlands)

Eckhardt, Martine M.; Mulder, Mascha C. Borgerhoff; Horemans, Herwin L.; van der Woude, Luc H.; Ribbers, Gerard M.

2011-01-01

Objective: To determine the effects of a temporary high custom made orthopaedic shoe on functional mobility, walking speed, and gait characteristics in hemiplegic stroke patients. In addition, interference of attentional demands and patient satisfaction were studied. Design: Clinical experimental

Shoe midsole longitudinal bending stiffness and running economy, joint energy, and EMG.

Science.gov (United States)

Roy, Jean-Pierre R; Stefanyshyn, Darren J

2006-03-01

It has been shown that mechanical energy is dissipated at the metatarsophalangeal (MTP) joint during running and jumping. Furthermore, increasing the longitudinal bending stiffness of the midsole significantly reduced the energy dissipated at the MTP joint and increased jump performance. It was hypothesized that increasing midsole longitudinal bending stiffness would also lead to improvements in running economy. This study investigated the influence of midsole longitudinal bending stiffness on running economy (performance variable) and evaluated the local effects on joint energetics and muscular activity. Carbon fiber plates were inserted into running shoe midsoles and running economy, joint energy, and electromyographic (EMG) data were collected on 13 subjects. Approximately a 1% metabolic energy savings was observed when subjects ran in a stiff midsole relative to the control midsole. Subjects with a greater body mass had a greater decrease in oxygen consumption rates in the stiff midsole relative to the control midsole condition. The stiffer midsoles showed no significant differences in energy absorption at the MTP joint compared with the control shoe. Finally, no significant changes were observed in muscular activation. Increasing midsole longitudinal bending stiffness led to improvements in running economy, yet the underlying mechanisms that can be attributed to this improvement are still not fully understood.

Size-selective performance evaluation of candidate aerosol inlets using polydisperse aerosols

Data.gov (United States)

U.S. Environmental Protection Agency — Presented are detailed techniques for the generation, collection, and analysis of polydisperse calibration aerosols for wind tunnel evaluation of size-selective...

The effect of size-selective samplers (cyclones) on XRD response

CSIR Research Space (South Africa)

Pretorius, CJ

2011-07-01

Full Text Available The study evaluated five size-selective samplers used in the South African mining industry to determine how their performance affects the X-ray powder diffraction (XRD) response when respirable dust samples are analysed for quartz using direct...

Modified random hinge transport mechanics and multiple scattering step-size selection in EGS5

International Nuclear Information System (INIS)

Wilderman, S.J.; Bielajew, A.F.

2005-01-01

The new transport mechanics in EGS5 allows for significantly longer electron transport step sizes and hence shorter computation times than required for identical problems in EGS4. But as with all Monte Carlo electron transport algorithms, certain classes of problems exhibit step-size dependencies even when operating within recommended ranges, sometimes making selection of step-sizes a daunting task for novice users. Further contributing to this problem, because of the decoupling of multiple scattering and continuous energy loss in the dual random hinge transport mechanics of EGS5, there are two independent step sizes in EGS5, one for multiple scattering and one for continuous energy loss, each of which influences speed and accuracy in a different manner. Further, whereas EGS4 used a single value of fractional energy loss (ESTEPE) to determine step sizes at all energies, to increase performance by decreasing the amount of effort expended simulating lower energy particles, EGS5 permits the fractional energy loss values which are used to determine both the multiple scattering and continuous energy loss step sizes to vary with energy. This results in requiring the user to specify four fractional energy loss values when optimizing computations for speed. Thus, in order to simplify step-size selection and to mitigate step-size dependencies, a method has been devised to automatically optimize step-size selection based on a single material dependent input related to the size of problem tally region. In this paper we discuss the new transport mechanics in EGS5 and describe the automatic step-size optimization algorithm. (author)

Influence of an unstable shoe on compensatory postural adjustments: An experimental evaluation

OpenAIRE

Andreia S. P. Sousa; Rui Macedo; Rubim Santos; João Manuel R. S. Tavares

2010-01-01

This study attempted to evaluate the influence of using an unstable shoe in muscle re-cruitment strategies and center of pressure (CoP) displacement after the application of an external perturba-tion. Fourteen healthy female subjects participated in this study. The electromyographic activity of medial ga-strocnemius, tibialis anterior, rectus femoris, biceps femoris, rectus abdominis and erector spinae muscles and the kinetic values to calculate the CoP were collected and analyzed after the a...

The effect of size on the oxygen electroreduction activity of mass-selected platinum nanoparticles

DEFF Research Database (Denmark)

Pérez Alonso, Francisco; McCarthy, David N; Nierhoff, Anders

2012-01-01

A matter of size: The particle size effect on the activity of the oxygen reduction reaction of size-selected platinum clusters was studied. The ORR activity decreased with decreasing Pt nanoparticle size, corresponding to a decrease in the fraction of terraces on the surfaces of the Pt nanopartic...

The Effect of Size on the Oxygen Electroreduction Activity of Mass‐Selected Platinum Nanoparticles

DEFF Research Database (Denmark)

Pérez Alonso, Francisco; McCarthy, David Norman; Nierhoff, Anders Ulrik Fregerslev

2012-01-01

A matter of size: The particle size effect on the activity of the oxygen reduction reaction of size-selected platinum clusters was studied. The ORR activity decreased with decreasing Pt nanoparticle size, corresponding to a decrease in the fraction of terraces on the surfaces of the Pt nanopartic...

Effects of long-term wearing of high-heeled shoes on the control of the body's center of mass motion in relation to the center of pressure during walking.

Science.gov (United States)

Chien, Hui-Lien; Lu, Tung-Wu; Liu, Ming-Wei

2014-04-01

High-heeled shoes are associated with instability and falling, leading to injuries such as fracture and ankle sprain. This study investigated the effects of habitual wearing of high-heeled shoes on the body's center of mass (COM) motion relative to the center of pressure (COP) during gait. Fifteen female experienced wearers and 15 matched controls walked with high-heeled shoes (7.3cm) while kinematic and ground reaction force data were measured and used to calculate temporal-distance parameters, joint moments, COM-COP inclination angles (IA) and the rate of IA changes (RCIA). Compared with inexperienced wearers, experienced subjects showed significantly reduced frontal IA with increased ankle pronator moments during single-limb support (pheel-strike, and reduced DLS time (pheel-strike (pknee extensor moments at toe-off (pheeled shoes, providing a basis for future design of strategies to minimize the risk of falling during high-heeled gait. Copyright © 2014 Elsevier B.V. All rights reserved.

Group selection on population size affects life-history patterns in the entomopathogenic nematode Steinernema carpocapsae.

Science.gov (United States)

Bashey, Farrah; Lively, Curtis M

2009-05-01

Selection is recognized to operate on multiple levels. In disease organisms, selection among hosts is thought to provide an important counterbalance to selection for faster growth within hosts. We performed three experiments, each selecting for a divergence in group size in the entomopathogenic nematode, Steinernema carpocapsae. These nematodes infect and kill insect larvae, reproduce inside the host carcass, and emerge as infective juveniles. We imposed selection on group size by selecting among hosts for either high or low numbers of emerging nematodes. Our goal was to determine whether this trait could respond to selection at the group level, and if so, to examine what other traits would evolve as correlated responses. One of the three experiments showed a significant response to group selection. In that experiment, the high-selected treatment consistently produced more emerging nematodes per host than the low-selected treatment. In addition, nematodes were larger and they emerged later from hosts in the low-selected lines. Despite small effective population sizes, the effects of inbreeding were small in this experiment. Thus, selection among hosts can be effective, leading to both a direct evolutionary response at the population level, as well as to correlated responses in populational and individual traits.

Discrimination of gender-, speed-, and shoe-dependent movement patterns in runners using full-body kinematics.

Science.gov (United States)

Maurer, Christian; Federolf, Peter; von Tscharner, Vinzenz; Stirling, Lisa; Nigg, Benno M

2012-05-01

Changes in gait kinematics have often been analyzed using pattern recognition methods such as principal component analysis (PCA). It is usually just the first few principal components that are analyzed, because they describe the main variability within a dataset and thus represent the main movement patterns. However, while subtle changes in gait pattern (for instance, due to different footwear) may not change main movement patterns, they may affect movements represented by higher principal components. This study was designed to test two hypotheses: (1) speed and gender differences can be observed in the first principal components, and (2) small interventions such as changing footwear change the gait characteristics of higher principal components. Kinematic changes due to different running conditions (speed - 3.1m/s and 4.9 m/s, gender, and footwear - control shoe and adidas MicroBounce shoe) were investigated by applying PCA and support vector machine (SVM) to a full-body reflective marker setup. Differences in speed changed the basic movement pattern, as was reflected by a change in the time-dependent coefficient derived from the first principal. Gender was differentiated by using the time-dependent coefficient derived from intermediate principal components. (Intermediate principal components are characterized by limb rotations of the thigh and shank.) Different shoe conditions were identified in higher principal components. This study showed that different interventions can be analyzed using a full-body kinematic approach. Within the well-defined vector space spanned by the data of all subjects, higher principal components should also be considered because these components show the differences that result from small interventions such as footwear changes. Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.

Creative prosthetic foot selection enables successful ambulation in stiletto high heels.

Science.gov (United States)

Russell Esposito, Elizabeth; Lipe, Delbert H; Rábago, Christopher A

2017-11-01

Walking in high heels presents biomechanical challenges, yet they remain part of many women's attire. However, women with a lower limb amputation are limited in available footwear options. Case description and methods: This case study is in response to one patient's assertion that she walked better and more symmetrically in heels than flat shoes with her below-knee prosthesis. She underwent gait analysis in athletic shoes and 10-cm stiletto high heels worn with a pediatric running foot to determine if these claims could be substantiated through biomechanical measures. Global gait asymmetry indices were calculated. Findings and outcomes: Asymmetry indices were nearly identical between athletic shoes and heels but joint-level findings differed substantially. Ankle mechanics were more symmetrical in heels but hip mechanics were less. The maintenance of symmetry in stiletto high heels does not imply maintenance of gait quality, as high heels are known to adversely affect some components walking mechanics. Clinical relevance Returning to high-heel wear is achievable for prosthesis users. Accommodations can be made using creativity in prosthetic foot selection to enable successful ambulation; however, attention to gait mechanics may be important for patient safety.

Device for selectively securing an object to a shaft

International Nuclear Information System (INIS)

Calizano, F.; Chauvel, M.

1984-01-01

A magnetic tape reel is secured to a reel drive motor shaft by a device including a hub secured to the shaft, a plurality of shoes, and actuating means for thrusting the shoes against the reel and for releasing them from contact with the reel. The securing device includes a cam mounted on the shaft in combination with a locking device including the cam periphery. The locking device thrusts the shoes against the object and is operated by rotation of the motor. The cam is immobilized in rotation while the shoes are locked

Size-Selective Modes of Aeolian Transport on Earth and Mars

Science.gov (United States)

Swann, C.; Ewing, R. C.; Sherman, D. J.; McLean, C. J.

2016-12-01

Aeolian sand transport is a dominant driver of surface change and dust emission on Mars. Estimates of aeolian sand transport on Earth and Mars rely on terrestrial transport models that do not differentiate between transport modes (e.g., creep vs. saltation), which limits estimates of the critical threshold for transport and the total sand flux during a transport event. A gap remains in understanding how the different modes contribute to the total sand flux. Experiments conducted at the MARtian Surface WInd Tunnel separated modes of transport for uniform and mixed grain size surfaces at Earth and Martian atmospheric pressures. Crushed walnut shells with a density of 1.0 gm/cm3 were used. Experiments resolved grain size distributions for creeping and saltating grains over 3 uniform surfaces, U1, U2, and U3, with median grain sizes of 308 µm, 721 µm, and 1294 µm, and a mixed grain size surface, M1, with median grain sizes of 519 µm. A mesh trap located 5 cm above the test bed and a surface creep trap were deployed to capture particles moving as saltation and creep. Grains that entered the creep trap at angles ≥ 75° were categorized as moving in creep mode only. Only U1 and M1 surfaces captured enough surface creep at both Earth and Mars pressure for statistically significant grain size analysis. Our experiments show that size selective transport differs between Earth and Mars conditions. The median grain size of particles moving in creep for both uniform and mixed surfaces are larger under Earth conditions. (U1Earth = 385 µm vs. U1Mars = 355 µm; M1Earth = 762 vs. M1Mars = 697 µm ). However, particles moving in saltation were larger under Mars conditions (U1Earth = 282 µm; U1Mars = 309 µm; M1Earth = 347 µm; M1Mars = 454 µm ). Similar to terrestrial experiments, the median size of surface creep is larger than the median grain size of saltation. Median sizes of U1, U2, U3 at Mars conditions for creep was 355 µm, 774 µm and 1574 µm. Saltation at Mars

Legal size limit implies strong fisheries selection on sexually selected traits in a temperate wrasse providing male-only parental care

Directory of Open Access Journals (Sweden)

Kim Aleksander Tallaksen Halvorsen

2015-12-01

Full Text Available Corkwing wrasse (Symphodus melops is a temperate wrasse displaying both sex and male dimorphism and is targeted in a size selective commercial fishery which has increased dramatically since 2008. Wrasses are supplied alive to salmon farms as cleaner fish to combat infestations of Salmon lice. In previous studies, growth and maturation has been found to differ among male morphs and sexes and these groups might therefore be targeted unevenly by the size selective fishery. In the present study, we address this by comparing size regulations and fishing practice with data on sex specific growth and maturation from Western and Southern Norway, two regions varying in density and life histories. Two years of field data on density and length measures was used together with a subsample of otoliths to determine sex specific growth patterns. In the region with high density, nesting males were found to grow faster and mature later than sneaker males and females. Here, most nesting males will reach the minimum size as juveniles, one and two years before females and sneakers respectively. In contrast, sexual dimorphism was much less pronounced in the low density region, and relaxed male-male competition over nesting sites seems a likely explanation for this pattern. Intensive harvesting with selective removal of the larger nesting males could potentially lead to short term effect such as sperm limitation and reduced offspring survival and thus affect the productivity of juveniles. In addition, the current fishing regime may select for reduced growth rates and earlier maturation and oppose sexual selection.

Selective Hydrogenation of Acrolein Over Pd Model Catalysts: Temperature and Particle-Size Effects.

Science.gov (United States)

O'Brien, Casey P; Dostert, Karl-Heinz; Schauermann, Swetlana; Freund, Hans-Joachim

2016-10-24

The selectivity in the hydrogenation of acrolein over Fe 3 O 4 -supported Pd nanoparticles has been investigated as a function of nanoparticle size in the 220-270 K temperature range. While Pd(111) shows nearly 100 % selectivity towards the desired hydrogenation of the C=O bond to produce propenol, Pd nanoparticles were found to be much less selective towards this product. In situ detection of surface species by using IR-reflection absorption spectroscopy shows that the selectivity towards propenol critically depends on the formation of an oxopropyl spectator species. While an overlayer of oxopropyl species is effectively formed on Pd(111) turning the surface highly selective for propenol formation, this process is strongly hindered on Pd nanoparticles by acrolein decomposition resulting in CO formation. We show that the extent of acrolein decomposition can be tuned by varying the particle size and the reaction temperature. As a result, significant production of propenol is observed over 12 nm Pd nanoparticles at 250 K, while smaller (4 and 7 nm) nanoparticles did not produce propenol at any of the temperatures investigated. The possible origin of particle-size dependence of propenol formation is discussed. This work demonstrates that the selectivity in the hydrogenation of acrolein is controlled by the relative rates of acrolein partial hydrogenation to oxopropyl surface species and of acrolein decomposition, which has significant implications for rational catalyst design. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Selection of portable tools for use in a size reduction facility

International Nuclear Information System (INIS)

Hawley, L.N.

1986-07-01

A range of portable tools are identified for development and eventual use within a remote operations facility for the size reduction of plutonium contaminated materials. The process of selection defines the work to be performed within the facility and matches this to the general categories of suitable tools. Specific commercial tools are then selected or, where none exists, proposals are made for the development of special tools. (author)

Local outcomes of globalization: manufacturing decline and labor response in the Philippine garment and shoe industries

NARCIS (Netherlands)

Beerepoot, N.

2008-01-01

In the past few decades, globalisation has led to major international shifts in labour intensive manufacturing generating ‘winners’ and ‘losers’ among countries, industries and workers. This paper uses case studies of the shoe industry in Marikina City and the garments sector in Metro Manila in

Allergic contact dermatitis caused by dimethylthiocarbamylbenzothiazole sulfide (DMTBS) in canvas shoes : in search of the culprit allergen

NARCIS (Netherlands)

Schuttelaar, Marie L; Meijer, Joost M; Engfeldt, Malin; Lapeere, Hilde; Goossens, An; Bruze, Magnus; Persson, Christina; Bergendorff, Ola

Background. During rubber vulcanization, new compounds can be formed. Objectives. To report a case of allergic shoe dermatitis in which the search for the allergen ultimately led to the identification of dimethylthiocarbamylbenzothiazole sulfide (DMTBS). Methods. A female presented with eczema on

Estimating Sound Intensity and its Effect on the Hearing Status of the Workers in an Industrial Shoe Factory.

Directory of Open Access Journals (Sweden)

Vida Ameri

1999-03-01

Full Text Available Introduction: We estimated the noise in an industrial shoe factory to determine the effect of noise in the workplace on the hearing status of the workers in such environments.Materials and method: the intensity of noise in dB in different parts of the factory was estimated. Then working people in each part was selected randomly and their hearing thresholds were evaluated by Conventional audiometry.Results: The results demonstrated that 23% were required to estimate thresholds more precisely and 95 needed close examination by Otolaryngologist. Besides, 10% of the workers suffered sensory neural hearing loss whose 2% of them diagnosed as NIHL.Discussion: Since the mentioned factory has good hearing conservation program for the workers, it seems that promoting the program can decline the number of noise induced hearing losses to the least numbers.

Hot Shoes in the Room: Authentication of Thermal Imaging for Quantitative Forensic Analysis

Directory of Open Access Journals (Sweden)

Justin H. J. Chua

2018-01-01

Full Text Available Thermal imaging has been a mainstay of military applications and diagnostic engineering. However, there is currently no formalised procedure for the use of thermal imaging capable of standing up to judicial scrutiny. Using a scientifically sound characterisation method, we describe the cooling function of three common shoe types at an ambient room temperature of 22 °C (295 K based on the digital output of a consumer-grade FLIR i50 thermal imager. Our method allows the reliable estimation of cooling time from pixel intensity values within a time interval of 3 to 25 min after shoes have been removed. We found a significant linear relationship between pixel intensity level and temperature. The calibration method allows the replicable determination of independent thermal cooling profiles for objects without the need for emissivity values associated with non-ideal black-body thermal radiation or system noise functions. The method has potential applications for law enforcement and forensic research, such as cross-validating statements about time spent by a person in a room. The use of thermal images can thus provide forensic scientists, law enforcement officials, and legislative bodies with an efficient and cost-effective tool for obtaining and interpreting time-based evidence.

SPORTS SHOES PURCHASE INTENTION AMONG MALAYSIAN VOLLEYBALL PLAYERS VS. NON-VOLLEYBALL PLAYERS: A CONCEPTUAL PAPER

Directory of Open Access Journals (Sweden)

GOH PIN SIANG

2013-12-01

Full Text Available The purpose of this study is to advance the understanding of volleyball players’ purchase intention toward sport shoes by investigating the relationship between the independent variables (endorsement, advertising, pricing and electronic word-of-mouth and purchase intention. Descriptive research and causal research will be used as the research design, thus questionnaire and experimentation will be used to obtain data. Primary data in this study is attained by distributing the questionnaire to the Malaysian volleyball players throughout several volleyball tournament venues in Malaysia. The experiment will be conducted by comparing two groups of respondents, including volleyball players and non-volleyball players. This study is limited to several independent variables such as endorsement, advertising, pricing and electronic word-of-mouth. This study is significant for marketers for solving the challenges faced in the sport industry. It also helps to identify consumers’ purchase preferences for sport shoes. The marketer would understand more about their targeted customers’ intentions to purchase, thus the sport industry related with sport marketing in Malaysia might gain more profit.

Available friction of ladder shoes and slip potential for climbing on a straight ladder.

Science.gov (United States)

Chang, Wen-Ruey; Chang, Chien-Chi; Matz, Simon

2005-07-15

Straight ladder accidents are a major safety problem. As a leading cause of injuries involving straight ladders, slips at the ladder base occur when the required friction exceeds the available friction at the ladder shoe and floor interface. The objectives of this experiment were to measure the available friction at the base of a portable straight ladder in contact with a floor and to estimate the slip potential of the ladder. The results of friction measurements indicated that the measured friction coefficient on the oily surfaces differed among the six commercially available ladder shoes evaluated. A statistical model was used to compare the available friction results from the current study with the friction requirements under different climbing conditions from a previous study based on their stochastic distributions to estimate the slip potential at the base of the ladder. The results showed that different climbing conditions used in the previous study could be supported by available friction on dry surfaces. However, when the ladder was put onto oily surfaces, resulting in a significant reduction in the available friction due to contamination, slip potential was significantly increased.

Genome size variation affects song attractiveness in grasshoppers: evidence for sexual selection against large genomes.

Science.gov (United States)

Schielzeth, Holger; Streitner, Corinna; Lampe, Ulrike; Franzke, Alexandra; Reinhold, Klaus

2014-12-01

Genome size is largely uncorrelated to organismal complexity and adaptive scenarios. Genetic drift as well as intragenomic conflict have been put forward to explain this observation. We here study the impact of genome size on sexual attractiveness in the bow-winged grasshopper Chorthippus biguttulus. Grasshoppers show particularly large variation in genome size due to the high prevalence of supernumerary chromosomes that are considered (mildly) selfish, as evidenced by non-Mendelian inheritance and fitness costs if present in high numbers. We ranked male grasshoppers by song characteristics that are known to affect female preferences in this species and scored genome sizes of attractive and unattractive individuals from the extremes of this distribution. We find that attractive singers have significantly smaller genomes, demonstrating that genome size is reflected in male courtship songs and that females prefer songs of males with small genomes. Such a genome size dependent mate preference effectively selects against selfish genetic elements that tend to increase genome size. The data therefore provide a novel example of how sexual selection can reinforce natural selection and can act as an agent in an intragenomic arms race. Furthermore, our findings indicate an underappreciated route of how choosy females could gain indirect benefits. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

The impact of feedstock cost on technology selection and optimum size

International Nuclear Information System (INIS)

Cameron, Jay B.; Kumar, Amit; Flynn, Peter C.

2007-01-01

Development of biomass projects at optimum size and technology enhances the role that biomass can make in mitigating greenhouse gas. Optimum sized plants can be built when biomass resources are sufficient to meet feedstock demand; examples include wood and forest harvest residues from extensive forests, and grain straw and corn stover from large agricultural regions. The impact of feedstock cost on technology selection is evaluated by comparing the cost of power from the gasification and direct combustion of boreal forest wood chips. Optimum size is a function of plant cost and the distance variable cost (DVC, $ dry tonne -1 km -1 ) of the biomass fuel; distance fixed costs (DFC, $ dry tonne -1 ) such as acquisition, harvesting, loading and unloading do not impact optimum size. At low values of DVC and DFC, as occur with wood chips sourced from the boreal forest, direct combustion has a lower power cost than gasification. At higher values of DVC and DFC, gasification has a lower power cost than direct combustion. This crossover in most economic technology will always arise when a more efficient technology with a higher capital cost per unit of output is compared to a less efficient technology with a lower capital cost per unit of output. In such cases technology selection cannot be separated from an analysis of feedstock cost

Effect of directional selection for body size on fluctuating asymmetry ...

Indian Academy of Sciences (India)

In this study, we investigated whether stress caused by artificial bidirectional selection for body size has any effect on the levels of FA of different morphological traits in Drosophila ananassae. The realised heritability (h2) was higher in low-line females and high-line males, which suggests an asymmetrical response to ...

Salts-based size-selective precipitation: toward mass precipitation of aqueous nanoparticles.

Science.gov (United States)

Wang, Chun-Lei; Fang, Min; Xu, Shu-Hong; Cui, Yi-Ping

2010-01-19

Purification is a necessary step before the application of nanocrystals (NCs), since the excess matter in nanoparticles solution usually causes a disadvantage to their subsequent coupling or assembling with other materials. In this work, a novel salts-based precipitation technique is originally developed for the precipitation and size-selective precipitation of aqueous NCs. Simply by addition of salts, NCs can be precipitated from the solution. After decantation of the supernatant solution, the precipitates can be dispersed in water again. By means of adjusting the addition amount of salt, size-selective precipitation of aqueous NCs can be achieved. Namely, the NCs with large size are precipitated preferentially, leaving small NCs in solution. Compared with the traditional nonsolvents-based precipitation technique, the current one is simpler and more rapid due to the avoidance of condensation and heating manipulations used in the traditional precipitation process. Moreover, the salts-based precipitation technique was generally available for the precipitation of aqueous nanoparticles, no matter if there were semiconductor NCs or metal nanoparticles. Simultaneously, the cost of the current method is also much lower than that of the traditional nonsolvents-based precipitation technique, making it applicable for mass purification of aqueous NCs.

Size dependent magnetism of mass selected deposited transition metal clusters

International Nuclear Information System (INIS)

Lau, T.

2002-05-01

The size dependent magnetic properties of small iron clusters deposited on ultrathin Ni/Cu(100) films have been studied with circularly polarised synchrotron radiation. For X-ray magnetic circular dichroism studies, the magnetic moments of size selected clusters were aligned perpendicular to the sample surface. Exchange coupling of the clusters to the ultrathin Ni/Cu(100) film determines the orientation of their magnetic moments. All clusters are coupled ferromagnetically to the underlayer. With the use of sum rules, orbital and spin magnetic moments as well as their ratios have been extracted from X-ray magnetic circular dichroism spectra. The ratio of orbital to spin magnetic moments varies considerably as a function of cluster size, reflecting the dependence of magnetic properties on cluster size and geometry. These variations can be explained in terms of a strongly size dependent orbital moment. Both orbital and spin magnetic moments are significantly enhanced in small clusters as compared to bulk iron, although this effect is more pronounced for the spin moment. Magnetic properties of deposited clusters are governed by the interplay of cluster specific properties on the one hand and cluster-substrate interactions on the other hand. Size dependent variations of magnetic moments are modified upon contact with the substrate. (orig.)

Storage Tanks - Selection Of Type, Design Code And Tank Sizing

International Nuclear Information System (INIS)

Shatla, M.N; El Hady, M.

2004-01-01

The present work gives an insight into the proper selection of type, design code and sizing of storage tanks used in the Petroleum and Process industries. In this work, storage tanks are classified based on their design conditions. Suitable design codes and their limitations are discussed for each tank type. The option of storage under high pressure and ambient temperature, in spherical and cigar tanks, is compared to the option of storage under low temperature and slight pressure (close to ambient) in low temperature and cryogenic tanks. The discussion is extended to the types of low temperature and cryogenic tanks and recommendations are given to select their types. A study of pressurized tanks designed according to ASME code, conducted in the present work, reveals that tanks designed according to ASME Section VIII DIV 2 provides cost savings over tanks designed according to ASME Section VIII DlV 1. The present work is extended to discuss the parameters that affect sizing of flat bottom cylindrical tanks. The analysis shows the effect of height-to-diameter ratio on tank instability and foundation loads

Enhanced Size Selection in Two-Photon Excitation for CsPbBr3 Perovskite Nanocrystals.

Science.gov (United States)

Chen, Junsheng; Chábera, Pavel; Pascher, Torbjörn; Messing, Maria E; Schaller, Richard; Canton, Sophie; Zheng, Kaibo; Pullerits, Tõnu

2017-10-19

Cesium lead bromide (CsPbBr 3 ) perovskite nanocrystals (NCs), with large two-photon absorption (TPA) cross-section and bright photoluminescence (PL), have been demonstrated as stable two-photon-pumped lasing medium. With two-photon excitation, red-shifted PL spectrum and increased PL lifetime is observed compared with one-photon excitation. We have investigated the origin of such difference using time-resolved laser spectroscopies. We ascribe the difference to the enhanced size selection of NCs by two-photon excitation. Because of inherent nonlinearity, the size dependence of absorption cross-section under TPA is stronger. Consequently, larger size NCs are preferably excited, leading to longer excited-state lifetime and red-shifted PL emission. In a broad view, the enhanced size selection in two-photon excitation of CsPbBr 3 NCs is likely a general feature of the perovskite NCs and can be tuned via NC size distribution to influence their performance within NC-based nonlinear optical materials and devices.

Influence of dorsiflexion shoes on neuromuscular fatigue of the plantar flexors after combined tapping-jumping exercises in volleyball players.

Science.gov (United States)

Lapole, Thomas; Ahmaidi, Said; Gaillien, Benjamin; Leprêtre, Pierre-Marie

2013-07-01

Dorsiflexion shoes could be useful to increase jumping performance. The aim of the present study was to investigate the impact of wearing shoes inducing moderate dorsiflexion (2°) on neuromuscular fatigue induced by volleyball exercises involving multiple stretch-shortening cycles. Squat jump (SJ) and countermovement jump (CMJ) performance, and plantar flexors isometric voluntary and evoked contractile properties were assessed in 10 unfamiliarized trained volleyball players before and after a 10-minute intensive combined tapping-jumping volleyball exercise performed, in blinded randomized conditions, with neutral (0°) or moderate dorsiflexion (2°). No significant difference was observed on SJ performance in neutral and moderate dorsiflexion conditions. However, CMJ height was initially lower with 2° dorsiflexion compared with 0° (p volleyball exercise also induced a significant decrease in maximal voluntary contraction (p volleyball players.

FOOTBALL PLAYERS’ LEGS BIOMECHANICS DURING THE GAME AND THE REQUIREMENTS FOR FOOTBALL SHOES

OpenAIRE

Cornelia Ionescu Luca; Cristina Secan

2013-01-01

Football players, during the game, find themselves in both static and dynamic positions. Movement may be accomplished through walking, marching, running and jumping. While walking, the step may be simple, if referred to a single leg or double when talking about both legs. The simple steps have different phases for the bare-foot, the impact phase, supported foot and oscillating shank-bone and propulsion. Football shoes for walking make contact with the support surface through cleats. The back...

Assessment of Competence in EVAR Stent Graft Sizing and Selection

DEFF Research Database (Denmark)

Strøm, M; Lönn, L.; Bech, B.

2017-01-01

Objectives and background: The aims of this study were to develop a test of competence in endovascular aortic repair (EVAR) stent graft sizing and selection; to examine the test for evidence of validity; and to explore the experience required for the task. Methods: The test was developed based...... measurements, Mann-Whitney U test could discriminate between experts and novices (p = .002), between experts and intermediates (p = .010), and between novices and intermediates (p = .036). In stent selection the experts performed significantly better than both the novices and the intermediates (p = .002 and p...... of competence in vessel analysis and stent graft selection for endovascular aortic repair. This was supported by strong validity evidence with good internal consistency and discriminatory ability. The tool may be used to facilitate training and certification of future endovascular specialists....

Physical Behavior in Older Persons during Daily Life: Insights from Instrumented Shoes

Directory of Open Access Journals (Sweden)

Christopher Moufawad el Achkar

2016-08-01

Full Text Available Activity level and gait parameters during daily life are important indicators for clinicians because they can provide critical insights into modifications of mobility and function over time. Wearable activity monitoring has been gaining momentum in daily life health assessment. Consequently, this study seeks to validate an algorithm for the classification of daily life activities and to provide a detailed gait analysis in older adults. A system consisting of an inertial sensor combined with a pressure sensing insole has been developed. Using an algorithm that we previously validated during a semi structured protocol, activities in 10 healthy elderly participants were recorded and compared to a wearable reference system over a 4 h recording period at home. Detailed gait parameters were calculated from inertial sensors. Dynamics of physical behavior were characterized using barcodes that express the measure of behavioral complexity. Activity classification based on the algorithm led to a 93% accuracy in classifying basic activities of daily life, i.e., sitting, standing, and walking. Gait analysis emphasizes the importance of metrics such as foot clearance in daily life assessment. Results also underline that measures of physical behavior and gait performance are complementary, especially since gait parameters were not correlated to complexity. Participants gave positive feedback regarding the use of the instrumented shoes. These results extend previous observations in showing the concurrent validity of the instrumented shoes compared to a body-worn reference system for daily-life physical behavior monitoring in older adults.

Shoe cushioning, body mass and running biomechanics as risk factors for running injury: a study protocol for a randomised controlled trial.

Science.gov (United States)

Malisoux, Laurent; Delattre, Nicolas; Urhausen, Axel; Theisen, Daniel

2017-08-21

Repetitive loading of the musculoskeletal system is suggested to be involved in the underlying mechanism of the majority of running-related injuries (RRIs). Accordingly, heavier runners are assumed to be at a higher risk of RRI. The cushioning system of modern running shoes is expected to protect runners again high impact forces, and therefore, RRI. However, the role of shoe cushioning in injury prevention remains unclear. The main aim of this study is to investigate the influence of shoe cushioning and body mass on RRI risk, while exploring simultaneously the association between running technique and RRI risk. This double-blinded randomised controlled trial will involve about 800 healthy leisure-time runners. They will randomly receive one of two running shoe models that will differ in their cushioning properties (ie, stiffness) by ~35%. The participants will perform a running test on an instrumented treadmill at their preferred running speed at baseline. Then they will be followed up prospectively over a 6-month period, during which they will self-report all their sports activities as well as any injury in an internet-based database TIPPS (Training and Injury Prevention Platform for Sports). Cox regression analyses will be used to compare injury risk between the study groups and to investigate the association among training, biomechanical and anatomical risk factors, and injury risk. The study was approved by the National Ethics Committee for Research (Ref: 201701/02 v1.1). Outcomes will be disseminated through publications in peer-reviewed journals, presentations at international conferences, as well as articles in popular magazines and on specialised websites. NCT03115437, Pre-results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Body size, swimming speed, or thermal sensitivity? Predator-imposed selection on amphibian larvae

Czech Academy of Sciences Publication Activity Database

Gvoždík, Lumír; Smolinský, Radovan

2015-01-01

Roč. 15, č. 1 (2015), č. článku 238. ISSN 1471-2148 R&D Projects: GA ČR GAP506/10/2170; GA ČR(CZ) GA15-07140S Institutional support: RVO:68081766 Keywords : Antipredator strategies * Ichthyosaura * Newts * Performance-fitness * Predator –prey interaction * Predator –prey size ratio * Selection differential * Selection experiment * Viability selection Subject RIV: EG - Zoology Impact factor: 3.406, year: 2015

Human Occipital and Parietal GABA Selectively Influence Visual Perception of Orientation and Size.

Science.gov (United States)

Song, Chen; Sandberg, Kristian; Andersen, Lau Møller; Blicher, Jakob Udby; Rees, Geraint

2017-09-13

GABA is the primary inhibitory neurotransmitter in human brain. The level of GABA varies substantially across individuals, and this variability is associated with interindividual differences in visual perception. However, it remains unclear whether the association between GABA level and visual perception reflects a general influence of visual inhibition or whether the GABA levels of different cortical regions selectively influence perception of different visual features. To address this, we studied how the GABA levels of parietal and occipital cortices related to interindividual differences in size, orientation, and brightness perception. We used visual contextual illusion as a perceptual assay since the illusion dissociates perceptual content from stimulus content and the magnitude of the illusion reflects the effect of visual inhibition. Across individuals, we observed selective correlations between the level of GABA and the magnitude of contextual illusion. Specifically, parietal GABA level correlated with size illusion magnitude but not with orientation or brightness illusion magnitude; in contrast, occipital GABA level correlated with orientation illusion magnitude but not with size or brightness illusion magnitude. Our findings reveal a region- and feature-dependent influence of GABA level on human visual perception. Parietal and occipital cortices contain, respectively, topographic maps of size and orientation preference in which neural responses to stimulus sizes and stimulus orientations are modulated by intraregional lateral connections. We propose that these lateral connections may underlie the selective influence of GABA on visual perception. SIGNIFICANCE STATEMENT GABA, the primary inhibitory neurotransmitter in human visual system, varies substantially across individuals. This interindividual variability in GABA level is linked to interindividual differences in many aspects of visual perception. However, the widespread influence of GABA raises the

Human Occipital and Parietal GABA Selectively Influence Visual Perception of Orientation and Size

Science.gov (United States)

Andersen, Lau Møller; Blicher, Jakob Udby

2017-01-01

GABA is the primary inhibitory neurotransmitter in human brain. The level of GABA varies substantially across individuals, and this variability is associated with interindividual differences in visual perception. However, it remains unclear whether the association between GABA level and visual perception reflects a general influence of visual inhibition or whether the GABA levels of different cortical regions selectively influence perception of different visual features. To address this, we studied how the GABA levels of parietal and occipital cortices related to interindividual differences in size, orientation, and brightness perception. We used visual contextual illusion as a perceptual assay since the illusion dissociates perceptual content from stimulus content and the magnitude of the illusion reflects the effect of visual inhibition. Across individuals, we observed selective correlations between the level of GABA and the magnitude of contextual illusion. Specifically, parietal GABA level correlated with size illusion magnitude but not with orientation or brightness illusion magnitude; in contrast, occipital GABA level correlated with orientation illusion magnitude but not with size or brightness illusion magnitude. Our findings reveal a region- and feature-dependent influence of GABA level on human visual perception. Parietal and occipital cortices contain, respectively, topographic maps of size and orientation preference in which neural responses to stimulus sizes and stimulus orientations are modulated by intraregional lateral connections. We propose that these lateral connections may underlie the selective influence of GABA on visual perception. SIGNIFICANCE STATEMENT GABA, the primary inhibitory neurotransmitter in human visual system, varies substantially across individuals. This interindividual variability in GABA level is linked to interindividual differences in many aspects of visual perception. However, the widespread influence of GABA raises the

Selection on male size, leg length and condition during mate search in a sexually highly dimorphic orb-weaving spider.

Science.gov (United States)

Foellmer, Matthias W; Fairbairn, Daphne J

2005-02-01

Mate search plays a central role in hypotheses for the adaptive significance of extreme female-biased sexual size dimorphism (SSD) in animals. Spiders (Araneae) are the only free-living terrestrial taxon where extreme SSD is common. The "gravity hypothesis" states that small body size in males is favoured during mate search in species where males have to climb to reach females, because body length is inversely proportional to achievable speed on vertical structures. However, locomotive performance of males may also depend on relative leg length. Here we examine selection on male body size and leg length during mate search in the highly dimorphic orb-weaving spider Argiope aurantia, using a multivariate approach to distinguish selection targeted at different components of size. Further, we investigate the scaling relationships between male size and energy reserves, and the differential loss of reserves. Adult males do not feed while roving, and a size-dependent differential energy storage capacity may thus affect male performance during mate search. Contrary to predictions, large body size was favoured in one of two populations, and this was due to selection for longer legs. Male size was not under selection in the second population, but we detected direct selection for longer third legs. Males lost energy reserves during mate search, but this was independent of male size and storage capacity scaled isometrically with size. Thus, mate search is unlikely to lead to selection for small male size, but the hypothesis that relatively longer legs in male spiders reflect a search-adapted morphology is supported.

Validation of Energy Expenditure Prediction Models Using Real-Time Shoe-Based Motion Detectors.

Science.gov (United States)

Lin, Shih-Yun; Lai, Ying-Chih; Hsia, Chi-Chun; Su, Pei-Fang; Chang, Chih-Han

2017-09-01

This study aimed to verify and compare the accuracy of energy expenditure (EE) prediction models using shoe-based motion detectors with embedded accelerometers. Three physical activity (PA) datasets (unclassified, recognition, and intensity segmentation) were used to develop three prediction models. A multiple classification flow and these models were used to estimate EE. The "unclassified" dataset was defined as the data without PA recognition, the "recognition" as the data classified with PA recognition, and the "intensity segmentation" as the data with intensity segmentation. The three datasets contained accelerometer signals (quantified as signal magnitude area (SMA)) and net heart rate (HR net ). The accuracy of these models was assessed according to the deviation between physically measured EE and model-estimated EE. The variance between physically measured EE and model-estimated EE expressed by simple linear regressions was increased by 63% and 13% using SMA and HR net , respectively. The accuracy of the EE predicted from accelerometer signals is influenced by the different activities that exhibit different count-EE relationships within the same prediction model. The recognition model provides a better estimation and lower variability of EE compared with the unclassified and intensity segmentation models. The proposed shoe-based motion detectors can improve the accuracy of EE estimation and has great potential to be used to manage everyday exercise in real time.

Questionnaire for usability evaluation of orthopaedic shoes: construction and reliability in patients with degenerative disorders of the foot

NARCIS (Netherlands)

Jannink, M.J.A.; de Vries, Jaap; Stewart, Roy E.; Groothoff, Johan W.; Lankhorst, Gustaaf J.

2004-01-01

Objective: To develop a self-report questionnaire for patients with degenerative disorders of the foot to evaluate the usability of their orthopaedic shoes, and to assess the reproducibility and responsiveness of the instrument. Design: Development of the Questionnaire for Usability Evaluation of

Questionnaire for usability evaluation of orthopaedic shoes : Construction and reliability in patients with degenerative disorders of the foot

NARCIS (Netherlands)

Jannink, MJA; de Vries, J; Stewart, RE; Groothoff, JW; Lankhorst, GJ

2004-01-01

Objective: To develop a self-report questionnaire for patients with degenerative disorders of the foot to evaluate the usability of their orthopaedic shoes, and to assess the reproducibility and responsiveness of the instrument. Design: Development of the Questionnaire for Usability Evaluation of

Questionnaire for usability evaluation of orthopaedic shoes : Construction and reliability in patients with degenerative disorders of the foot

NARCIS (Netherlands)

Jannink, MJA; de Vries, J; Stewart, RE; Groothoff, JW; Lankhorst, GJ

Objective: To develop a self-report questionnaire for patients with degenerative disorders of the foot to evaluate the usability of their orthopaedic shoes, and to assess the reproducibility and responsiveness of the instrument. Design: Development of the Questionnaire for Usability Evaluation of

Differences in productive robustness in rabbits selected for reproductive longevity or litter size

DEFF Research Database (Denmark)

Theilgaard, R; Baselga, M; Blas, E

2009-01-01

The aim of this work was to evaluate the ability of a line selected for reproductive longevity (LP) to confront productive challenges compared to a line selected during 31 generations for litter size at weaning (V). A total of 133 reproductive rabbit does were used (72 and 61 from LP and V lines,...

Preliminarily study on the maximum handling size, prey size and species selectivity of growth hormone transgenic and non-transgenic common carp Cyprinus carpio when foraging on gastropods

Science.gov (United States)

Zhu, Tingbing; Zhang, Lihong; Zhang, Tanglin; Wang, Yaping; Hu, Wei; Olsen, Rolf Eric; Zhu, Zuoyan

2017-10-01

The present study preliminarily examined the differences in maximum handling size, prey size and species selectivity of growth hormone transgenic and non-transgenic common carp Cyprinus carpio when foraging on four gastropods species (Bellamya aeruginosa, Radix auricularia, Parafossarulus sinensis and Alocinma longicornis) under laboratory conditions. In the maximum handling size trial, five fish from each age group (1-year-old and 2-year-old) and each genotype (transgenic and non-transgenic) of common carp were individually allowed to feed on B. aeruginosa with wide shell height range. The results showed that maximum handling size increased linearly with fish length, and there was no significant difference in maximum handling size between the two genotypes. In the size selection trial, three pairs of 2-year-old transgenic and non-transgenic carp were individually allowed to feed on three size groups of B. aeruginosa. The results show that the two genotypes of C. carpio favored the small-sized group over the large-sized group. In the species selection trial, three pairs of 2-year-old transgenic and non-transgenic carp were individually allowed to feed on thin-shelled B. aeruginosa and thick-shelled R. auricularia, and five pairs of 2-year-old transgenic and non-transgenic carp were individually allowed to feed on two gastropods species (P. sinensis and A. longicornis) with similar size and shell strength. The results showed that both genotypes preferred thin-shelled Radix auricularia rather than thick-shelled B. aeruginosa, but there were no significant difference in selectivity between the two genotypes when fed on P. sinensis and A. longicornis. The present study indicates that transgenic and non-transgenic C. carpio show similar selectivity of predation on the size- and species-limited gastropods. While this information may be useful for assessing the environmental risk of transgenic carp, it does not necessarily demonstrate that transgenic common carp might

Women's Preferences for Penis Size: A New Research Method Using Selection among 3D Models.

Science.gov (United States)

Prause, Nicole; Park, Jaymie; Leung, Shannon; Miller, Geoffrey

2015-01-01

Women's preferences for penis size may affect men's comfort with their own bodies and may have implications for sexual health. Studies of women's penis size preferences typically have relied on their abstract ratings or selecting amongst 2D, flaccid images. This study used haptic stimuli to allow assessment of women's size recall accuracy for the first time, as well as examine their preferences for erect penis sizes in different relationship contexts. Women (N = 75) selected amongst 33, 3D models. Women recalled model size accurately using this method, although they made more errors with respect to penis length than circumference. Women preferred a penis of slightly larger circumference and length for one-time (length = 6.4 inches/16.3 cm, circumference = 5.0 inches/12.7 cm) versus long-term (length = 6.3 inches/16.0 cm, circumference = 4.8 inches/12.2 cm) sexual partners. These first estimates of erect penis size preferences using 3D models suggest women accurately recall size and prefer penises only slightly larger than average.

Women's Preferences for Penis Size: A New Research Method Using Selection among 3D Models.

Directory of Open Access Journals (Sweden)

Nicole Prause

Full Text Available Women's preferences for penis size may affect men's comfort with their own bodies and may have implications for sexual health. Studies of women's penis size preferences typically have relied on their abstract ratings or selecting amongst 2D, flaccid images. This study used haptic stimuli to allow assessment of women's size recall accuracy for the first time, as well as examine their preferences for erect penis sizes in different relationship contexts. Women (N = 75 selected amongst 33, 3D models. Women recalled model size accurately using this method, although they made more errors with respect to penis length than circumference. Women preferred a penis of slightly larger circumference and length for one-time (length = 6.4 inches/16.3 cm, circumference = 5.0 inches/12.7 cm versus long-term (length = 6.3 inches/16.0 cm, circumference = 4.8 inches/12.2 cm sexual partners. These first estimates of erect penis size preferences using 3D models suggest women accurately recall size and prefer penises only slightly larger than average.

Portion, package or tableware size for changing selection and consumption of food, alcohol and tobacco

Science.gov (United States)

Hollands, Gareth J; Shemilt, Ian; Marteau, Theresa M; Jebb, Susan A; Lewis, Hannah B; Wei, Yinghui; Higgins, Julian Pt; Ogilvie, David

2015-01-01

Background Overeating and harmful alcohol and tobacco use have been linked to the aetiology of various non-communicable diseases, which are among the leading global causes of morbidity and premature mortality. As people are repeatedly exposed to varying sizes and shapes of food, alcohol and tobacco products in environments such as shops, restaurants, bars and homes, this has stimulated public health policy interest in product size and shape as potential targets for intervention. Objectives 1) To assess the effects of interventions involving exposure to different sizes or sets of physical dimensions of a portion, package, individual unit or item of tableware on unregulated selection or consumption of food, alcohol or tobacco products in adults and children. 2) To assess the extent to which these effects may be modified by study, intervention and participant characteristics. Search methods We searched CENTRAL, MEDLINE, EMBASE, PsycINFO, eight other published or grey literature databases, trial registries and key websites up to November 2012, followed by citation searches and contacts with study authors. This original search identified eligible studies published up to July 2013, which are fully incorporated into the review. We conducted an updated search up to 30 January 2015 but further eligible studies are not yet fully incorporated due to their minimal potential to change the conclusions. Selection criteria Randomised controlled trials with between-subjects (parallel-group) or within-subjects (cross-over) designs, conducted in laboratory or field settings, in adults or children. Eligible studies compared at least two groups of participants, each exposed to a different size or shape of a portion of a food (including non-alcoholic beverages), alcohol or tobacco product, its package or individual unit size, or of an item of tableware used to consume it, and included a measure of unregulated selection or consumption of food, alcohol or tobacco. Data collection and

Stepping into others’ shoes: a cognitive perspective on target audience orientation in written translation

OpenAIRE

Apfelthaler, Matthias

2014-01-01

This paper suggests what might allow translators to orient themselves towards their target audience in the translation process. To shed light on translators’ ability to put themselves into their target audience’s shoes, I adopt a cognitive perspective by drawing on current findings from psychology, cognitive science and neuroscience. I depart from the notion of target audience as applied to written translation. Aspects to this concept and the terminology of audience in translation studies are...

Size selectivity of commercial (300 MC) and larger square mesh top ...

African Journals Online (AJOL)

In the present study, size selectivity of a commercial (300 MC) and a larger square mesh top panel (LSMTPC) codend for blue whiting (Micromesistius poutassou) were tested on a commercial trawl net in the international waters between Turkey and Greece. Trawling, performed during daylight was carried out at depths ...

Morphological impact on the reaction kinetics of size-selected cobalt oxide nanoparticles

International Nuclear Information System (INIS)

Bartling, Stephan; Meiwes-Broer, Karl-Heinz; Barke, Ingo; Pohl, Marga-Martina

2015-01-01

Apart from large surface areas, low activation energies are essential for efficient reactions, particularly in heterogeneous catalysis. Here, we show that not only the size of nanoparticles but also their detailed morphology can crucially affect reaction kinetics, as demonstrated for mass-selected, soft-landed, and oxidized cobalt clusters in a 6 nm to 18 nm size range. The method of reflection high-energy electron diffraction is extended to the quantitative determination of particle activation energies which is applied for repeated oxidation and reduction cycles at the same particles. We find unexpectedly small activation barriers for the reduction reaction of the largest particles studied, despite generally increasing barriers for growing sizes. We attribute these observations to the interplay of reaction-specific material transport with a size-dependent inner particle morphology

[Occupational risks of a shoe industry from the workers' perspective].

Science.gov (United States)

Luz, Fernanda Reinher da; Loro, Marli Maria; Zeitoune, Regina Célia Gollner; Kolankiewicz, Adriane Cristina Bernat; Rosanelli, Cleci Schmidt Piovesan

2013-01-01

This is a qualitative and descriptive study, which aimed to identify the occupational risks of a shoe industry, as well as the preventive measures taken against those risks, from the workers' perspective. The sample consisted of fifteen workers. Data were collected through semi-structured interviews and analyzed according to content analysis. The ethical aspects were respected and the research was approved by the Committee of Ethics in Research of the Northwest Regional University of Rio Grande do Sul. The results showed that the workers are aware of the risks of their work process, made use of safety measures for personal protection, and the company offers safety devices, informing and performing periodical visits to the sectors, aiming to develop educational actions.

Site-specific fragmentation of polystyrene molecule using size-selected Ar gas cluster ion beam

International Nuclear Information System (INIS)

Moritani, Kousuke; Mukai, Gen; Hashinokuchi, Michihiro; Mochiji, Kozo

2009-01-01

The secondary ion mass spectrum (SIMS) of a polystyrene thin film was investigated using a size-selected Ar gas cluster ion beam (GCIB). The fragmentation in the SIM spectrum varied by kinetic energy per atom (E atom ); the E atom dependence of the secondary ion intensity of the fragment species of polystyrene can be essentially classified into three types based on the relationship between E atom and the dissociation energy of a specific bonding site in the molecule. These results indicate that adjusting E atom of size-selected GCIB may realize site-specific bond breaking within a molecule. (author)

When bigger is not better: selection against large size, high condition and fast growth in juvenile lemon sharks.

Science.gov (United States)

Dibattista, J D; Feldheim, K A; Gruber, S H; Hendry, A P

2007-01-01

Selection acting on large marine vertebrates may be qualitatively different from that acting on terrestrial or freshwater organisms, but logistical constraints have thus far precluded selection estimates for the former. We overcame these constraints by exhaustively sampling and repeatedly recapturing individuals in six cohorts of juvenile lemon sharks (450 age-0 and 255 age-1 fish) at an enclosed nursery site (Bimini, Bahamas). Data on individual size, condition factor, growth rate and inter-annual survival were used to test the 'bigger is better', 'fatter is better' and 'faster is better' hypotheses of life-history theory. For age-0 sharks, selection on all measured traits was weak, and generally acted against large size and high condition. For age-1 sharks, selection was much stronger, and consistently acted against large size and fast growth. These results suggest that selective pressures at Bimini may be constraining the evolution of large size and fast growth, an observation that fits well with the observed small size and low growth rate of juveniles at this site. Our results support those of some other recent studies in suggesting that bigger/fatter/faster is not always better, and may often be worse.

Ultrathin self-assembled anionic polymer membranes for superfast size-selective separation

Science.gov (United States)

Deng, Chao; Zhang, Qiu Gen; Han, Guang Lu; Gong, Yi; Zhu, Ai Mei; Liu, Qing Lin

2013-10-01

Nanoporous membranes with superior separation performance have become more crucial with increasing concerns in functional nanomaterials. Here novel ultrahigh permeable nanoporous membranes have been fabricated on macroporous supports by self-assembly of anionic polymer on copper hydroxide nanostrand templates in organic solution. This facile approach has a great potential for the fabrication of ultrathin anionic polymer membranes as a general method. The as-fabricated self-assembled membranes have a mean pore size of 5-12 nm and an adjustable thickness as low as 85 nm. They allow superfast permeation of water, and exhibit excellent size-selective separation properties and good fouling resistance for negatively-charged solutes during filtration. The 85 nm thick membrane has an ultrahigh water flux (3306 l m-2 h-1 bar-1) that is an order of magnitude larger than commercial membranes, and can highly efficiently separate 5 and 15 nm gold nanoparticles from their mixtures. The newly developed nanoporous membranes have a wide application in separation and purification of biomacromolecules and nanoparticles.Nanoporous membranes with superior separation performance have become more crucial with increasing concerns in functional nanomaterials. Here novel ultrahigh permeable nanoporous membranes have been fabricated on macroporous supports by self-assembly of anionic polymer on copper hydroxide nanostrand templates in organic solution. This facile approach has a great potential for the fabrication of ultrathin anionic polymer membranes as a general method. The as-fabricated self-assembled membranes have a mean pore size of 5-12 nm and an adjustable thickness as low as 85 nm. They allow superfast permeation of water, and exhibit excellent size-selective separation properties and good fouling resistance for negatively-charged solutes during filtration. The 85 nm thick membrane has an ultrahigh water flux (3306 l m-2 h-1 bar-1) that is an order of magnitude larger than

SPORTS SHOES PURCHASE INTENTION AMONG MALAYSIAN VOLLEYBALL PLAYERS VS. NON-VOLLEYBALL PLAYERS: A CONCEPTUAL PAPER

OpenAIRE

GOH PIN SIANG; ZURAIDAH SULAIMAN

2013-01-01

The purpose of this study is to advance the understanding of volleyball players’ purchase intention toward sport shoes by investigating the relationship between the independent variables (endorsement, advertising, pricing and electronic word-of-mouth) and purchase intention. Descriptive research and causal research will be used as the research design, thus questionnaire and experimentation will be used to obtain data. Primary data in this study is attained by distributing the questionnaire to...

The impact of Nassau grouper size and abundance on scuba diver site selection and MPA economics

NARCIS (Netherlands)

Rudd, M.A.; Tupper, M.H.

2002-01-01

Since many fisheries are size-selective, the establishment of marine protected areas (MPAs) is expected to increase both the average size and abundance of exploited species, such as the valuable but vulnerable Nassau grouper ( Epinephelus striatus ). Increases in mean size and/or abundance of

Chlorine dioxide is a size-selective antimicrobial agent.

Directory of Open Access Journals (Sweden)

Zoltán Noszticzius

Full Text Available BACKGROUND / AIMS: ClO2, the so-called "ideal biocide", could also be applied as an antiseptic if it was understood why the solution killing microbes rapidly does not cause any harm to humans or to animals. Our aim was to find the source of that selectivity by studying its reaction-diffusion mechanism both theoretically and experimentally. METHODS: ClO2 permeation measurements through protein membranes were performed and the time delay of ClO2 transport due to reaction and diffusion was determined. To calculate ClO2 penetration depths and estimate bacterial killing times, approximate solutions of the reaction-diffusion equation were derived. In these calculations evaporation rates of ClO2 were also measured and taken into account. RESULTS: The rate law of the reaction-diffusion model predicts that the killing time is proportional to the square of the characteristic size (e.g. diameter of a body, thus, small ones will be killed extremely fast. For example, the killing time for a bacterium is on the order of milliseconds in a 300 ppm ClO2 solution. Thus, a few minutes of contact time (limited by the volatility of ClO2 is quite enough to kill all bacteria, but short enough to keep ClO2 penetration into the living tissues of a greater organism safely below 0.1 mm, minimizing cytotoxic effects when applying it as an antiseptic. Additional properties of ClO2, advantageous for an antiseptic, are also discussed. Most importantly, that bacteria are not able to develop resistance against ClO2 as it reacts with biological thiols which play a vital role in all living organisms. CONCLUSION: Selectivity of ClO2 between humans and bacteria is based not on their different biochemistry, but on their different size. We hope initiating clinical applications of this promising local antiseptic.

Shoe cleat position during cycling and its effect on subsequent running performance in triathletes.

Science.gov (United States)

Viker, Tomas; Richardson, Matt X

2013-01-01

Research with cyclists suggests a decreased load on the lower limbs by placing the shoe cleat more posteriorly, which may benefit subsequent running in a triathlon. This study investigated the effect of shoe cleat position during cycling on subsequent running. Following bike-run training sessions with both aft and traditional cleat positions, 13 well-trained triathletes completed a 30 min simulated draft-legal triathlon cycling leg, followed by a maximal 5 km run on two occasions, once with aft-placed and once with traditionally placed cleats. Oxygen consumption, breath frequency, heart rate, cadence and power output were measured during cycling, while heart rate, contact time, 200 m lap time and total time were measured during running. Cardiovascular measures did not differ between aft and traditional cleat placement during the cycling protocol. The 5 km run time was similar for aft and traditional cleat placement, at 1084 ± 80 s and 1072 ± 64 s, respectively, as was contact time during km 1 and 5, and heart rate and running speed for km 5 for the two cleat positions. Running speed during km 1 was 2.1% ± 1.8 faster (P beneficial effects of an aft cleat position on subsequent running in a short distance triathlon.

ORTHOPEDIC AND BIOMECHANICAL FEATURES FOR RUNNING SHOES FOR SPRINTS, MEDIUM AND LONG DISTANCES

OpenAIRE

Cornelia Ionescu Luca; Cristina Secan

2013-01-01

Athletics is the sport discipline that has 3 simple event types and 2 multiple events competitions. The simple events are: running, jumps, and throws and the multiple events competitions are: decathlon and heptathlon. The running events are 100 m, 200 m and 400 m dash and 800 m, 1500 m, 5000 m and 10000 m; 100m, 400 m and 3000 m hurdles; marathon, 20 km and 50 km march and cross-country. Different athletics events will require different types of sport shoes, designed for the specific events....

Work-related depression and associated factors in a shoe manufacturing factory in Haiphong City, Vietnam

Directory of Open Access Journals (Sweden)

Khue Pham Minh

2014-12-01

Full Text Available Objectives: To determine the prevalence and associated factors of work-related depression among the employees of a shoe manufacturing factory in Haiphong City, Vietnam. Material and Methods: We carried out this cross-sectional study among 420 workers in 2012 in Le Lai II Shoe Manufacturing Factory in Haiphong City, Vietnam using Karasek’s Job Content Questionnaire (JCQ and the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM IV tool for measuring depression. Results: The study results show that a relatively high proportion of workers (20.7% belongs to the high-strain group based on Karasek’s model. The prevalence of work-related depression among workers was relatively high (18.8%. The factors associated with depression at work were high psychological demand (adjusted OR = 3.0, 95% CI: 1.1–8.3, low social support (adjusted OR = 4.7, 95% CI: 1.2–12.8, inadequate work protection materials (OR = 4.1, 95% CI: 2.2–10.1 and work absenteeism (OR = 6.2, 95% CI: 2.5–18.9. Conclusions: Strengthening the social support network (involving supervisors and co‑workers, reducing psychological job demand and assuring work protection materials at the workplace may highly facilitate reducing work-related depression.

"I could cry, the amount of shoes I can't get into": A qualitative exploration of the factors that influence retail footwear selection in women with rheumatoid arthritis

Science.gov (United States)

2011-01-01

Background Studies have reported that women with rheumatoid arthritis (RA) are not wearing NHS supplied therapeutic footwear; therefore it is likely they are wearing footwear sourced through retailers. Previous research gives limited information (largely associated with cosmesis) on people's perceptions on the relationships that exist between retail footwear, well-being and quality of life. This study aimed to explore the perceptions of women with RA regarding their choice of retail footwear and identify the factors influencing retail footwear selection. Methods Eleven women with RA wearing normal retail footwear were recruited from an out-patient podiatry clinic in the south east of England. Semi-structured interviews were carried out and an interpretative phenomenological approach was adopted for data collection and transcript analysis. Results Six key themes were revealed from the analysis: (1) the nature of foot complaints and deformities, (2) aesthetic appearance and design of footwear, (3) body image, (4) psychosocial aspects, (5) Perceptions of footwear and (6) the therapeutic value of retail shoes. These contributed to an overarching concept of loss of choice associated with retail footwear. In particular, the areas discussed most frequently throughout were themes (2), (3) and (4), which were notably more 'emotional' in nature. Conclusions Limitations in retail footwear for these women have impacted on their individuality, linking significantly with their body image. The loss of choice in footwear as a consequence of the disease impacts negatively on emotions, wellbeing and was identified in reduced self-perceived quality of life. PMID:21794134

Portion, package or tableware size for changing selection and consumption of food, alcohol and tobacco.

Science.gov (United States)

Hollands, Gareth J; Shemilt, Ian; Marteau, Theresa M; Jebb, Susan A; Lewis, Hannah B; Wei, Yinghui; Higgins, Julian P T; Ogilvie, David

2015-09-14

Overeating and harmful alcohol and tobacco use have been linked to the aetiology of various non-communicable diseases, which are among the leading global causes of morbidity and premature mortality. As people are repeatedly exposed to varying sizes and shapes of food, alcohol and tobacco products in environments such as shops, restaurants, bars and homes, this has stimulated public health policy interest in product size and shape as potential targets for intervention. 1) To assess the effects of interventions involving exposure to different sizes or sets of physical dimensions of a portion, package, individual unit or item of tableware on unregulated selection or consumption of food, alcohol or tobacco products in adults and children.2) To assess the extent to which these effects may be modified by study, intervention and participant characteristics. We searched CENTRAL, MEDLINE, EMBASE, PsycINFO, eight other published or grey literature databases, trial registries and key websites up to November 2012, followed by citation searches and contacts with study authors. This original search identified eligible studies published up to July 2013, which are fully incorporated into the review. We conducted an updated search up to 30 January 2015 but further eligible studies are not yet fully incorporated due to their minimal potential to change the conclusions. Randomised controlled trials with between-subjects (parallel-group) or within-subjects (cross-over) designs, conducted in laboratory or field settings, in adults or children. Eligible studies compared at least two groups of participants, each exposed to a different size or shape of a portion of a food (including non-alcoholic beverages), alcohol or tobacco product, its package or individual unit size, or of an item of tableware used to consume it, and included a measure of unregulated selection or consumption of food, alcohol or tobacco. We applied standard Cochrane methods to select eligible studies for inclusion and

Portion Sizes from 24-Hour Dietary Recalls Differed by Sex among Those Who Selected the Same Portion Size Category on a Food Frequency Questionnaire.

Science.gov (United States)

Kang, Minji; Park, Song-Yi; Boushey, Carol J; Wilkens, Lynne R; Monroe, Kristine R; Le Marchand, Loïc; Kolonel, Laurence N; Murphy, Suzanne P; Paik, Hee-Young

2018-05-08

Accounting for sex differences in food portions may improve dietary measurement; however, this factor has not been well examined. The aim of this study was to examine sex differences in reported food portions from 24-hour dietary recalls (24HDRs) among those who selected the same portion size category on a quantitative food frequency questionnaire (QFFQ). This study was conducted with a cross-sectional design. Participants (n=319) were members of the Hawaii-Los Angeles Multiethnic Cohort who completed three 24HDRs and a QFFQ in a calibration study conducted in 2010 and 2011. Portions of individual foods reported from 24HDRs served as the outcome measures. Mean food portions from 24HDRs were compared between men and women who reported the same portion size on the QFFQ, after adjustment for race/ethnicity using a linear regression model. Actual amount and the assigned amount of the selected portion size in the QFFQ were compared using one-sample t test for men and women separately. Of 163 food items with portion size options listed in the QFFQ, 32 were reported in 24HDRs by ≥20 men and ≥20 women who selected the same portion size in the QFFQ. Although they chose the same portion size on the QFFQ, mean intake amounts from 24HDRs were significantly higher for men than for women for "beef/lamb/veal," "white rice," "brown/wild rice," "lettuce/tossed salad," "eggs cooked/raw," "whole wheat/rye bread," "buns/rolls," and "mayonnaise in sandwiches." For men, mean portions of 14 items from the 24HDRs were significantly different from the assigned amounts for QFFQ items (seven higher and seven lower), whereas for women, mean portions of 14 items were significantly lower from the assigned amounts (with five significantly higher). These sex differences in reported 24HDR food portions-even among participants who selected the same portion size on the QFFQ-suggest that the use of methods that account for differences in the portions consumed by men and women when QFFQs are

Size selective isocyanate aerosols personal air sampling using porous plastic foams

International Nuclear Information System (INIS)

Cong Khanh Huynh; Trinh Vu Duc

2009-01-01

As part of a European project (SMT4-CT96-2137), various European institutions specialized in occupational hygiene (BGIA, HSL, IOM, INRS, IST, Ambiente e Lavoro) have established a program of scientific collaboration to develop one or more prototypes of European personal samplers for the collection of simultaneous three dust fractions: inhalable, thoracic and respirable. These samplers based on existing sampling heads (IOM, GSP and cassettes) use Polyurethane Plastic Foam (PUF) according to their porosity to support sampling and separator size of the particles. In this study, the authors present an original application of size selective personal air sampling using chemical impregnated PUF to perform isocyanate aerosols capturing and derivatizing in industrial spray-painting shops.

How is Size Related to Profitability? Post-Consolidation Evidence from Selected Banks in Nigeria

Directory of Open Access Journals (Sweden)

Funso T. Kolapo

2016-10-01

Full Text Available It is theoretically believed that increase in firm size would result to increase in firm profitability. Therefore, this study examines the relationship between size and profitability of six banks in Nigeria after the 2005 consolidation exercise. The measure of profitability is return on assets. Employing the static panel data regression method, the study found that size has an insignificant negative relationship with bank profitability. This study concludes that the 2005 consolidation exercise did not enhance the profitability of the selected banks.

A miniature shoe-mounted orientation determination system for accurate indoor heading and trajectory tracking.

Science.gov (United States)

Zhang, Shengzhi; Yu, Shuai; Liu, Chaojun; Liu, Sheng

2016-06-01

Tracking the position of pedestrian is urgently demanded when the most commonly used GPS (Global Position System) is unavailable. Benefited from the small size, low-power consumption, and relatively high reliability, micro-electro-mechanical system sensors are well suited for GPS-denied indoor pedestrian heading estimation. In this paper, a real-time miniature orientation determination system (MODS) was developed for indoor heading and trajectory tracking based on a novel dual-linear Kalman filter. The proposed filter precludes the impact of geomagnetic distortions on pitch and roll that the heading is subjected to. A robust calibration approach was designed to improve the accuracy of sensors measurements based on a unified sensor model. Online tests were performed on the MODS with an improved turntable. The results demonstrate that the average RMSE (root-mean-square error) of heading estimation is less than 1°. Indoor heading experiments were carried out with the MODS mounted on the shoe of pedestrian. Besides, we integrated the existing MODS into an indoor pedestrian dead reckoning application as an example of its utility in realistic actions. A human attitude-based walking model was developed to calculate the walking distance. Test results indicate that mean percentage error of indoor trajectory tracking achieves 2% of the total walking distance. This paper provides a feasible alternative for accurate indoor heading and trajectory tracking.

Effect of a size-selective biomanipulation on nutrient release by gizzard shad in Florida (USA lakes

Directory of Open Access Journals (Sweden)

Schaus M.H.

2013-11-01

Full Text Available Although fish removal for biomanipulation is often highly size-selective, our understanding of the nutrient cycling effects of this size-selection is poor. To better understand these effects, we measured nutrient excretion by gizzard shad (Dorosoma cepedianum of differing sizes from four central Florida (USA lakes and combined these measures with gillnet biomass and size-structure data to compare lake-wide effects among lakes and years. Direct removal of P in fish tissue ranged from 0.16−1.00 kg·P·ha-1·yr-1. The estimated reduction in P excretion due to harvest ranged from 30.8−202.5 g·P·ha-1·month-1, with effects strongly tied to the biomass and size structure harvested. The amount of P release prevented per kg of fish removed was lower in previously unharvested lakes, due to the initial removal of larger fish with lower mass-specific excretion rates. Gill net mesh size impacted the size distribution of harvested fish, with smaller fish that excrete more P per gram being more vulnerable to smaller mesh sizes. In Lake Apopka, decreasing the mesh size by 1.3 cm yielded P excretion reductions that were 10.7−15.1% larger. Fish harvesting to reduce internal nutrient cycling can be most effective by increasing total harvest and by harvesting smaller size classes over multiple years.

The influence of high-heeled shoes on strain and tension force of the anterior talofibular ligament and plantar fascia during balanced standing and walking.

Science.gov (United States)

Yu, Jia; Wong, Duo Wai-Chi; Zhang, Hongtao; Luo, Zong-Ping; Zhang, Ming

2016-10-01

High-heeled shoes have the capability to alter the strain and tension of ligamentous structures between the foot and ankle, which may result in ankle instability. However, high-heeled shoes can also reduce the strain on plantar fascia, which may be beneficial for the treatment of plantar fasciitis. In this study, the influence of heel height on strain and tension force applied to the anterior talofibular ligament (ATL) and plantar fascia were investigated. A three-dimensional finite element model of coupled foot-ankle-shoe complex was constructed. Four heel heights were studied in balanced standing: 0 in. (0cm), 1 in. (2.54cm), 2 in. (5.08cm), and 3 in. (7.62cm). A walking analysis was performed using 2-in. (5.08cm) high-heeled shoes. During balanced standing, the tension force on the ATL increased from 14.8N to 97.0N, with a six-fold increase in strain from 0 in. to 3 in. (0-7.62cm). The tension force and the average strain on the plantar fascia decreased from 151.0N (strain: 0.74%) to 59.6N (strain: 0.28%) when the heel height increased from 0 in. to 2 in. (0-5.08cm). When heel height reached 3 in. (7.62cm), the force and average strain increased to 278.3N (strain: 1.33%). The walking simulation showed that the fascia stretched out while the ATL loading decreased during push off. The simulation outcome demonstrated the influence of heel height on ATL alteration and plantar fascia strain, which implies risks for ankle injury and suggests guidance for the treatment of plantar fasciitis. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

Liquidity Determinants of the Selected Banking Sectors and their Size Groups

Directory of Open Access Journals (Sweden)

Jana Laštůvková

2016-01-01

Full Text Available The article focuses on the factors affecting the liquidity of selected bank sectors, as well as their size groups, using panel regression analysis. For higher complexity of the results, multiple dependent variables are used: liquidity creation, outflow and net change. The values are calculated based on the specific method of liquidity risk measurement – gross liquidity flows. The results indicate both multiple effects of some factors on the given variables, as well as isolated influence of factors on a single liquidity form or size group. Thus, when looking for determinants using just one form of liquidity, such as creation, the results need not necessarily comprehensively show the influence of the given factors, and can lead to erroneous conclusions. The results also point to the differing behaviours of the size groups and their different sensitivity on the factors; smaller banks have shown higher sensitivity on macroeconomic variables. Higher flexibility in regulation could lead to higher optimization.

Clinical assessment of dynamic coefficient of friction effects in shoe-sole trituration of patients with drop foot.

Science.gov (United States)

Nima, Jamshidi; Firooz, Salami

2012-06-01

The aim of this study was examining the effect of human factors such as plantar friction, contact period time, and impulse on shoe-sole trituration of drop foot patients. Twenty-five patients with drop foot and twenty normal subjects were recruited in the study. The force plate and its related software's recorded human factor (coefficient of friction, ground reaction force, time of stance phase) as time dependent parameters. Dynamic coefficient of friction patterns were categorized based on their magnitude versus time when the longitudinal axis of the sole was plotted as the Y-axis and the transverse axis of the sole as X-axis during stance phase. The result of this research indicated that the average coefficient of friction among drop foot patients is 77.53 % (p value <0.05) lower than the normal subjects. Also the time of stance phase among drop foot patients is 7.56 % (p value <0.05) greater than normal subjects. There is no difference in the peaks, of vertical ground reaction force between normal and control group. The findings of this research revealed that the time of stance phase has a key role in shoe-sole trituration of patients with drop foot.

Sexual selection accounts for the geographic reversal of sexual size dimorphism in the dung fly, sepsis punctum (Diptera: Sepsidae).

Science.gov (United States)

Puniamoorthy, Nalini; Schäfer, Martin A; Blanckenhorn, Wolf U

2012-07-01

Sexual size dimorphism (SSD) varies widely across and within species. The differential equilibrium model of SSD explains dimorphism as the evolutionary outcome of consistent differences in natural and sexual selection between the sexes. Here, we comprehensively examine a unique cross-continental reversal in SSD in the dung fly, Sepsis punctum. Using common garden laboratory experiments, we establish that SSD is male-biased in Europe and female-biased in North America. When estimating sexual (pairing success) and fecundity selection (clutch size of female partner) on males under three operational sex ratios (OSRs), we find that the intensity of sexual selection is significantly stronger in European versus North American populations, increasing with male body size and OSR in the former only. Fecundity selection on female body size also increases strongly with egg number and weakly with egg volume, however, equally on both continents. Finally, viability selection on body size in terms of intrinsic (physiological) adult life span in the laboratory is overall nil and does not vary significantly across all seven populations. Although it is impossible to prove causality, our results confirm the differential equilibrium model of SSD in that differences in sexual selection intensity account for the reversal in SSD in European versus North American populations, presumably mediating the ongoing speciation process in S. punctum. © 2012 The Author(s).

High sintering resistance of size-selected platinum cluster catalysts by suppressed ostwald ripening

DEFF Research Database (Denmark)

Wettergren, Kristina; Schweinberger, Florian F.; Deiana, Davide

2014-01-01

on different supports exhibit remarkable intrinsic sintering resistance even under reaction conditions. The observed stability is related to suppression of Ostwald ripening by elimination of its main driving force via size-selection. This study thus constitutes a general blueprint for the rational design...... of sintering resistant catalyst systems and for efficient experimental strategies to determine sintering mechanisms. Moreover, this is the first systematic experimental investigation of sintering processes in nanoparticle systems with an initially perfectly monomodal size distribution under ambient conditions....

Effect of netting direction and number of meshes around on size selection in the codend for Baltic cod (Gadus morhua)

DEFF Research Database (Denmark)

Wienbeck, Harald; Herrmann, Bent; Moderhak, Waldemar

2011-01-01

We investigated experimentally the effect that turning the netting direction 90° (T90) and halving the number of meshes around in the circumference in a diamond mesh codend had on size selection of Baltic cod. The results generally agreed with predictions of a previous simulation-based study. Both...... modifications had a significant positive effect on the size selection of cod. The best selection results were obtained for a codend in which both factors were applied together. For that codend, very little between-haul variation in cod size selection was detected, especially compared to the reference codend...

Size-selective sorting in bubble streaming flows: Particle migration on fast time scales

Science.gov (United States)

Thameem, Raqeeb; Rallabandi, Bhargav; Hilgenfeldt, Sascha

2015-11-01

Steady streaming from ultrasonically driven microbubbles is an increasingly popular technique in microfluidics because such devices are easily manufactured and generate powerful and highly controllable flows. Combining streaming and Poiseuille transport flows allows for passive size-sensitive sorting at particle sizes and selectivities much smaller than the bubble radius. The crucial particle deflection and separation takes place over very small times (milliseconds) and length scales (20-30 microns) and can be rationalized using a simplified geometric mechanism. A quantitative theoretical description is achieved through the application of recent results on three-dimensional streaming flow field contributions. To develop a more fundamental understanding of the particle dynamics, we use high-speed photography of trajectories in polydisperse particle suspensions, recording the particle motion on the time scale of the bubble oscillation. Our data reveal the dependence of particle displacement on driving phase, particle size, oscillatory flow speed, and streaming speed. With this information, the effective repulsive force exerted by the bubble on the particle can be quantified, showing for the first time how fast, selective particle migration is effected in a streaming flow. We acknowledge support by the National Science Foundation under grant number CBET-1236141.

Induced Effects on Red Imported Fire Ant (Hymenoptera: Formicidae) Forager Size Ratios by Pseudacteon spp. (Diptera: Phoridae): Implications on Bait Size Selection.

Science.gov (United States)

Reed, J J; Puckett, R T; Gold, R E

2015-10-01

Red imported fire ants, Solenopsis invicta Buren, are adversely affected by phorid flies in the genus Pseudacteon by instigating defensive behaviors in their hosts, and in turn reducing the efficiency of S. invicta foraging. Multiple Pseudacteon species have been released in Texas, and research has been focused on the establishment and spread of these introduced biological control agents. Field experiments were conducted to determine bait particle size selection of S. invicta when exposed to phorid populations. Four different particle sizes of two candidate baits were offered to foragers (one provided by a pesticide manufacturer, and a laboratory-created bait). Foragers selectively were attracted to, and removed more 1-1.4-mm particles than any other bait size. The industry-provided bait is primarily made of particles in the 1.4-2.0 mm size, larger than what was selected by the ants in this study. While there was a preference for foragers to be attracted to and rest on the industry-provided blank bait, S. invicta removed more of the laboratory-created bait from the test vials. There was an abundance of workers with head widths ranging from 0.5-0.75 mm collected from baits. This was dissimilar from a previous study wherein phorid flies were not active and in which large workers were collected in higher abundance at the site. This implies that phorid fly activity caused a shift for red imported fire ant colonies to have fewer large foragers. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Footwear recommendations and patterns among orthopaedic foot and ankle surgeons: a survey.

Science.gov (United States)

Farber, Daniel C; Knutsen, Elisa J

2013-12-01

Foot and ankle surgeons are in a unique position to educate patients about the importance of proper footwear. Neither their recommendations regarding shoe selection nor their own footwear patterns have previously been reported. A total of 866 members of the American Orthopaedic Foot & Ankle Society (AOFAS) were asked to complete a survey via the Internet. Topics included specific shoe brands recommended to patients, how attributes of footwear are communicated, and respondents' footwear habits. In all, 276 (32%) surgeons responded, and 64% recommended New Balance athletic shoes to patients; 26% did not recommend specific brands. It was found that 50% wear New Balance athletic shoes; 25% wear Nike. Rockport (27%) and SAS (27%) were the most recommended dress shoes. In all, 76% are familiar with AOFAS guidelines for proper shoe fit, but only 56% educated their patients about the guidelines; 43% do not consider what patients might think of their shoes when selecting what to wear in the clinical setting. Despite the multitude of different brands, several were commonly recommended. Respondents seem to be aware of the impact of their own shoe selection on patients' perspectives of footwear, but many do not consider themselves role models for proper footwear.

Footwear in rock climbing: Current practice.

Science.gov (United States)

McHenry, R D; Arnold, G P; Wang, W; Abboud, R J

2015-09-01

Many rock climbers wear ill-fitting and excessively tight footwear during activity. However, there is insufficient evidence of the extent or harms of this practice. To investigate footwear use in rock climbers with a focus on issues surrounding fit. A cross-sectional study with active rock climbers of over one year of experience completing a survey on their activity and footwear. Additionally, the authors quantified foot and shoe lengths and sizes alongside demographic data. Ill-fitting and excessively tight footwear was found in 55 out of 56 rock climbers. Foot pain during activity was also commonplace in 91% of the climbers. A mean size reduction of almost 4 UK shoe sizes was found between the climbers' street shoe size and that of their climbing footwear using a calibrated foot/shoe ruler. There is an unfortunate association of climbers of higher abilities seeking a tighter shoe fit (pfootwear use amongst rock climbers, further investigation may aim to quantify its impact and seek a solution balancing climbing performance while mitigating foot injury. Copyright © 2015 Elsevier Ltd. All rights reserved.

Body Size Preference of Marine Animals in Relation to Extinction Selectivity

Science.gov (United States)

Sriram, A.; Idgunji, S.; Heim, N. A.; Payne, J.

2014-12-01

comparisons showed that mean size decreased across the extinction boundary. This was due to the fact that new originating genera were smaller than the genera that survived. Our results show that there is variability in the relationship between body size and extinction selectivity in various mass extinctions.

Size- and charge selectivity of glomerular filtration in Type 1 (insulin-dependent) diabetic patients with and without albuminuria

DEFF Research Database (Denmark)

Deckert, T; Kofoed-Enevoldsen, A; Vidal, P

1993-01-01

Albuminuria is the first clinical event in the development of diabetic nephropathy. We assessed glomerular charge- and size selectivity in 51 patients with Type 1 (insulin-dependent) diabetes mellitus of juvenile onset and 11 healthy individuals. Patients were allocated to five groups. The urinary...... techniques and tubular protein reabsorption by excretion of beta 2-microglobulin. Charge selectivity was estimated from the IgG/IgG4 selectivity index. Size selectivity was measured by dextran clearance. Dextran was measured by refractive index detection after fractionation (2 A fractions in the range 26...... macromolecular pathways in the development of diabetic nephropathy....

Artificial selection on relative brain size in the guppy reveals costs and benefits of evolving a larger brain.

Science.gov (United States)

Kotrschal, Alexander; Rogell, Björn; Bundsen, Andreas; Svensson, Beatrice; Zajitschek, Susanne; Brännström, Ioana; Immler, Simone; Maklakov, Alexei A; Kolm, Niclas

2013-01-21

The large variation in brain size that exists in the animal kingdom has been suggested to have evolved through the balance between selective advantages of greater cognitive ability and the prohibitively high energy demands of a larger brain (the "expensive-tissue hypothesis"). Despite over a century of research on the evolution of brain size, empirical support for the trade-off between cognitive ability and energetic costs is based exclusively on correlative evidence, and the theory remains controversial. Here we provide experimental evidence for costs and benefits of increased brain size. We used artificial selection for large and small brain size relative to body size in a live-bearing fish, the guppy (Poecilia reticulata), and found that relative brain size evolved rapidly in response to divergent selection in both sexes. Large-brained females outperformed small-brained females in a numerical learning assay designed to test cognitive ability. Moreover, large-brained lines, especially males, developed smaller guts, as predicted by the expensive-tissue hypothesis, and produced fewer offspring. We propose that the evolution of brain size is mediated by a functional trade-off between increased cognitive ability and reproductive performance and discuss the implications of these findings for vertebrate brain evolution. Copyright © 2013 Elsevier Ltd. All rights reserved.

"I could cry, the amount of shoes I can't get into": A qualitative exploration of the factors that influence retail footwear selection in women with rheumatoid arthritis

Directory of Open Access Journals (Sweden)

Naidoo Serena

2011-07-01

Full Text Available Abstract Background Studies have reported that women with rheumatoid arthritis (RA are not wearing NHS supplied therapeutic footwear; therefore it is likely they are wearing footwear sourced through retailers. Previous research gives limited information (largely associated with cosmesis on people's perceptions on the relationships that exist between retail footwear, well-being and quality of life. This study aimed to explore the perceptions of women with RA regarding their choice of retail footwear and identify the factors influencing retail footwear selection. Methods Eleven women with RA wearing normal retail footwear were recruited from an out-patient podiatry clinic in the south east of England. Semi-structured interviews were carried out and an interpretative phenomenological approach was adopted for data collection and transcript analysis. Results Six key themes were revealed from the analysis: (1 the nature of foot complaints and deformities, (2 aesthetic appearance and design of footwear, (3 body image, (4 psychosocial aspects, (5 Perceptions of footwear and (6 the therapeutic value of retail shoes. These contributed to an overarching concept of loss of choice associated with retail footwear. In particular, the areas discussed most frequently throughout were themes (2, (3 and (4, which were notably more 'emotional' in nature. Conclusions Limitations in retail footwear for these women have impacted on their individuality, linking significantly with their body image. The loss of choice in footwear as a consequence of the disease impacts negatively on emotions, wellbeing and was identified in reduced self-perceived quality of life.

Techniques used by United Kingdom consultant plastic surgeons to select implant size for primary breast augmentation.

Science.gov (United States)

Holmes, W J M; Timmons, M J; Kauser, S

2015-10-01

Techniques used to estimate implant size for primary breast augmentation have evolved since the 1970s. Currently no consensus exists on the optimal method to select implant size for primary breast augmentation. In 2013 we asked United Kingdom consultant plastic surgeons who were full members of BAPRAS or BAAPS what was their technique for implant size selection for primary aesthetic breast augmentation. We also asked what was the range of implant sizes they commonly used. The answers to question one were grouped into four categories: experience, measurements, pre-operative external sizers and intra-operative sizers. The response rate was 46% (164/358). Overall, 95% (153/159) of all respondents performed some form of pre-operative assessment, the others relied on "experience" only. The most common technique for pre-operative assessment was by external sizers (74%). Measurements were used by 57% of respondents and 3% used intra-operative sizers only. A combination of measurements and sizers was used by 34% of respondents. The most common measurements were breast base (68%), breast tissue compliance (19%), breast height (15%), and chest diameter (9%). The median implant size commonly used in primary breast augmentation was 300cc. Pre-operative external sizers are the most common technique used by UK consultant plastic surgeons to select implant size for primary breast augmentation. We discuss the above findings in relation to the evolution of pre-operative planning techniques for breast augmentation. Copyright © 2015 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

How to Select Children's Shoes

Science.gov (United States)

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An integrated approach for determining the size of hardwood group-selection openings

Science.gov (United States)

Chris B. LeDoux

1999-01-01

The use of group-selection methods is becoming more widespread as landowners and forest managers attempt to respond to public pressure to reduce the size of clearcut blocks. Several studies have shown that harvesting timber in smaller groups or clumps increases the cost of operations for both cable and ground-based logging systems. Recent regeneration studies have...

An Efficient Adaptive Window Size Selection Method for Improving Spectrogram Visualization

Directory of Open Access Journals (Sweden)

Shibli Nisar

2016-01-01

Full Text Available Short Time Fourier Transform (STFT is an important technique for the time-frequency analysis of a time varying signal. The basic approach behind it involves the application of a Fast Fourier Transform (FFT to a signal multiplied with an appropriate window function with fixed resolution. The selection of an appropriate window size is difficult when no background information about the input signal is known. In this paper, a novel empirical model is proposed that adaptively adjusts the window size for a narrow band-signal using spectrum sensing technique. For wide-band signals, where a fixed time-frequency resolution is undesirable, the approach adapts the constant Q transform (CQT. Unlike the STFT, the CQT provides a varying time-frequency resolution. This results in a high spectral resolution at low frequencies and high temporal resolution at high frequencies. In this paper, a simple but effective switching framework is provided between both STFT and CQT. The proposed method also allows for the dynamic construction of a filter bank according to user-defined parameters. This helps in reducing redundant entries in the filter bank. Results obtained from the proposed method not only improve the spectrogram visualization but also reduce the computation cost and achieves 87.71% of the appropriate window length selection.

What enables size-selective trophy hunting of wildlife?

Directory of Open Access Journals (Sweden)

Chris T Darimont

Full Text Available Although rarely considered predators, wildlife hunters can function as important ecological and evolutionary agents. In part, their influence relates to targeting of large reproductive adults within prey populations. Despite known impacts of size-selective harvests, however, we know little about what enables hunters to kill these older, rarer, and presumably more wary individuals. In other mammalian predators, predatory performance varies with knowledge and physical condition, which accumulates and declines, respectively, with age. Moreover, some species evolved camouflage as a physical trait to aid in predatory performance. In this work, we tested whether knowledge-based faculty (use of a hunting guide with accumulated experience in specific areas, physical traits (relative body mass [RBM] and camouflage clothing, and age can predict predatory performance. We measured performance as do many hunters: size of killed cervid prey, using the number of antler tines as a proxy. Examining ∼ 4300 online photographs of hunters posing with carcasses, we found that only the presence of guides increased the odds of killing larger prey. Accounting for this effect, modest evidence suggested that unguided hunters presumably handicapped with the highest RBM actually had greater odds of killing large prey. There was no association with hunter age, perhaps because of our coarse measure (presence of grey hair and the performance trade-offs between knowledge accumulation and physical deterioration with age. Despite its prevalence among sampled hunters (80%, camouflage had no influence on size of killed prey. Should these patterns be representative of other areas and prey, and our interpretations correct, evolutionarily-enlightened harvest management might benefit from regulatory scrutiny on guided hunting. More broadly, we suggest that by being nutritionally and demographically de-coupled from prey and aided by efficient killing technology and road access

Selecting the optimum plot size for a California design-based stream and wetland mapping program.

Science.gov (United States)

Lackey, Leila G; Stein, Eric D

2014-04-01

Accurate estimates of the extent and distribution of wetlands and streams are the foundation of wetland monitoring, management, restoration, and regulatory programs. Traditionally, these estimates have relied on comprehensive mapping. However, this approach is prohibitively resource-intensive over large areas, making it both impractical and statistically unreliable. Probabilistic (design-based) approaches to evaluating status and trends provide a more cost-effective alternative because, compared with comprehensive mapping, overall extent is inferred from mapping a statistically representative, randomly selected subset of the target area. In this type of design, the size of sample plots has a significant impact on program costs and on statistical precision and accuracy; however, no consensus exists on the appropriate plot size for remote monitoring of stream and wetland extent. This study utilized simulated sampling to assess the performance of four plot sizes (1, 4, 9, and 16 km(2)) for three geographic regions of California. Simulation results showed smaller plot sizes (1 and 4 km(2)) were most efficient for achieving desired levels of statistical accuracy and precision. However, larger plot sizes were more likely to contain rare and spatially limited wetland subtypes. Balancing these considerations led to selection of 4 km(2) for the California status and trends program.

Size-selective separation of polydisperse gold nanoparticles in supercritical ethane.

Science.gov (United States)

Williams, Dylan P; Satherley, John

2009-04-09

The aim of this study was to use supercritical ethane to selectively disperse alkanethiol-stabilized gold nanoparticles of one size from a polydisperse sample in order to recover a monodisperse fraction of the nanoparticles. A disperse sample of metal nanoparticles with diameters in the range of 1-5 nm was prepared using established techniques then further purified by Soxhlet extraction. The purified sample was subjected to supercritical ethane at a temperature of 318 K in the pressure range 50-276 bar. Particles were characterized by UV-vis absorption spectroscopy, TEM, and MALDI-TOF mass spectroscopy. The results show that with increasing pressure the dispersibility of the nanoparticles increases, this effect is most pronounced for smaller nanoparticles. At the highest pressure investigated a sample of the particles was effectively stripped of all the smaller particles leaving a monodisperse sample. The relationship between dispersibility and supercritical fluid density for two different size samples of alkanethiol-stabilized gold nanoparticles was considered using the Chrastil chemical equilibrium model.

Charge- and Size-Selective Molecular Separation using Ultrathin Cellulose Membranes

KAUST Repository

Puspasari, Tiara

2016-08-30

To date, it is still a challenge to prepare high-flux and highselectivity microporous membranes thinner than 20 nm without introducing defects. In this work, we report for the first time the application of cellulose membranes for selective separation of small molecules. A freestanding cellulose membrane as thin as 10 nm has been prepared through regeneration of trimethylsilyl cellulose (TMSC). The freestanding membrane can be transferred to any desired substrate and shows a normalized flux as high as 700 L m−2 h−1 bar−1 when supported by a porous alumina disc. According to filtration experiments, the membrane exhibits precise size-sieving performances with an estimated pore size between 1.5–3.5 nm depending on the regeneration period and initial TMSC concentration. A perfect discrimination of anionic molecules over neutral species is demonstrated. Moreover, the membrane demonstrates high reproducibility, high scale-up potential, and excellent stability over two months.

The Effect of Shoe Insole Stiffness on Leg Stiffness during Stance Phase of Running in Two Different Speeds ‎among Active Men

Directory of Open Access Journals (Sweden)

Zeinab Tazike-Lemeski

2016-08-01

Full Text Available Introduction: The effect of shoe insoles with different characteristics and in different running speeds on lower-limb stiffness is still ‎controversial. The aim of this study was to investigate the effect of two types of insoles (soft and semi-rigid in two ‎different running speeds on leg stiffness during stance phase of running among active men.‎ Materials and Methods: ‎15 male students without any background of lower extremity injury were selected. Subjects were asked to run with ‎two controlled velocities of 3.0 ± 0.2 and 5.0 ± 0.1 m/s in control and insole conditions (soft and semi-rigid on a ‎force plate, placed on the middle of 15-meter runway. The cinematics and cinetics of motion were measured and ‎calculated using 5 video cameras and one force plate. The leg stiffness was achieved via dividing the vertical ‎ground reaction force by leg compression. Two-factor repeated measures ANOVA was used to test the hypothesis at ‎the significance level of P £ 0.050.‎ Results: There was a significant difference between the two types of insoles on leg stiffness. In fact, semi-rigid insole significantly increased leg stiffness (P < 0.001. However, this discrepancy was not related to the running speed (P = 0.999. In addition, there was no significant difference between the two different speeds on leg stiffness (P = 0.632. Conclusion: It seems that the increase in shoe insole stiffness may increase the leg stiffness. Furthermore, the effect of insole ‎stiffness is not related to the running speed, and leg stiffness will remains constant in low to medium running speeds.‎

Plantar pressure measurements. Rational shoe-wear in patients with rheumatoid arthritis.

Science.gov (United States)

Barrett, J P

1976-03-15

Objective measurements of forefoot plantar pressures were taken on 25 patients with rheumatoid arthritis. The Harris mat footprint test and the Brand slipper sock test were used to assess both compressive shearing forces. The Harris mat footprint test is a static used when the patient is unshod. The Brand slipper sock test is a dynamic test used while the shoe is worn. An experimental sandal was designed and used for the treatment of symptomatic forefoot callosities. The Harris mat footprint test results improved dramatically after the patients had worn an experimental sandal for six months. The Brand slipper sock test results showed marked diminution in the pressure profile while the patients wore the experimental sandal. All of the patients improved in their functional abilities while wearing the experimental sandal.

Effectiveness of custom-made orthopaedic shoes in the reduction of foot pain and pressure in patients with degenerative disorders of the foot

NARCIS (Netherlands)

Jannink, Michiel; van Dijk, Henk; IJzerman, Maarten; Groothuis-Oudshoorn, Karen; Groothoff, Johan; Lankhorst, Gustaaf

2006-01-01

Background: Degenerative disorders of the foot often are painful during standing and walking. It is assumed that, because of bone deformity, callus, and deformity of the plantar pads, the plantar pressure distribution changes. Prescription of orthopaedic shoes for patients with degenerative

Effect of surgical shoes on brake response time after first metatarsal osteotomy?a prospective cohort study

OpenAIRE

Dammerer, Dietmar; Braito, Matthias; Biedermann, Rainer; Ban, Michael; Giesinger, Johannes; Haid, Christian; Liebensteiner, Michael C.; Kaufmann, Gerhard

2016-01-01

Background The aim of this study is to assess patients? driving ability when wearing surgical shoes following right-sided first metatarsal osteotomy. Methods From August 2013 to August 2015, 42 consecutive patients (mean age 54.5?years) with right-sided hallux valgus deformity underwent first metatarsal osteotomy. Patients were tested for brake response time (BRT) 1?day preoperatively (control run) and at 2 and 6?weeks postoperatively. Two different types of foot orthosis were investigated. B...

AERB information booklet: personal protective equipment- safety footwear

International Nuclear Information System (INIS)

1992-01-01

The main classes of safety footwear required for industrial operations in the units of Department of Atomic Energy are the following; leather safety boots and shoes, firemen's leather boots - Wellington type, electrical safety shoes, chemical safety shoes, shoes suitable for mining operations. The criteria to be adopted for selection of safety shoes for nuclear installations are given. (M.K.V.). 5 annexures, 1 appendix

Shoe concerns and foot problems of wearers of safety footwear.

Science.gov (United States)

Marr, S J; Quine, S

1993-05-01

In Australia workers in many industries are required to wear safety footwear (footwear incorporating a steel toe cap). An investigation of the problems reported by 321 workers (70 per cent male) employed in a broad range of work activities and required to wear safety footwear was conducted in 1990 and 1991. Respondents were interviewed by a professionally trained podiatrist using a structured questionnaire followed by a foot examination. An extremely high percentage (91 per cent) of subjects reported one or more foot problems (which were verified by the podiatrist), and most considered that the safety footwear either caused the problem or adversely affected an existing foot condition. The main shoe concerns reported were excessive heat (65 per cent of all respondents), inflexible soles (52 per cent), weight (48 per cent) and pressure from steel toe cap (47 per cent). Certain gender differences were identified. General recommendations are made.

Effect of field view size and lighting on unique-hue selection using Natural Color System object colors.

Science.gov (United States)

Shamey, Renzo; Zubair, Muhammad; Cheema, Hammad

2015-08-01

The aim of this study was twofold, first to determine the effect of field view size and second of illumination conditions on the selection of unique hue samples (UHs: R, Y, G and B) from two rotatable trays, each containing forty highly chromatic Natural Color System (NCS) samples, on one tray corresponding to 1.4° and on the other to 5.7° field of view size. UH selections were made by 25 color-normal observers who repeated assessments three times with a gap of at least 24h between trials. Observers separately assessed UHs under four illumination conditions simulating illuminants D65, A, F2 and F11. An apparent hue shift (statistically significant for UR) was noted for UH selections at 5.7° field of view compared to those at 1.4°. Observers' overall variability was found to be higher for UH stimuli selections at the larger field of view. Intra-observer variability was found to be approximately 18.7% of inter-observer variability in selection of samples for both sample sizes. The highest intra-observer variability was under simulated illuminant D65, followed by A, F11, and F2. Copyright © 2015 Elsevier Ltd. All rights reserved.

Arrays of Size-Selected Metal Nanoparticles Formed by Cluster Ion Beam Technique

DEFF Research Database (Denmark)

Ceynowa, F. A.; Chirumamilla, Manohar; Zenin, Volodymyr

2018-01-01

Deposition of size-selected copper and silver nanoparticles (NPs) on polymers using cluster beam technique is studied. It is shown that ratio of particle embedment in the film can be controlled by simple thermal annealing. Combining electron beam lithography, cluster beam deposition, and heat...... with required configurations which can be applied for wave-guiding, resonators, in sensor technologies, and surface enhanced Raman scattering....

Supra-annular structure assessment for self-expanding transcatheter heart valve size selection in patients with bicuspid aortic valve.

Science.gov (United States)

Liu, Xianbao; He, Yuxin; Zhu, Qifeng; Gao, Feng; He, Wei; Yu, Lei; Zhou, Qijing; Kong, Minjian; Wang, Jian'an

2018-04-01

To explore assessment of supra-annular structure for self-expanding transcatheter heart valve (THV) size selection in patients with bicuspid aortic stenosis (AS). Annulus-based device selection from CT measurement is the standard sizing strategy for tricuspid aortic valve before transcatheter aortic valve replacement (TAVR). Because of supra-annular deformity, device selection for bicuspid AS has not been systemically studied. Twelve patients with bicuspid AS who underwent TAVR with self-expanding THVs were included in this study. To assess supra-annular structure, sequential balloon aortic valvuloplasty was performed in every 2 mm increments until waist sign occurred with less than mild regurgitation. Procedural results and 30 day follow-up outcomes were analyzed. Seven patients (58.3%) with 18 mm; three patients (25%) with sequential 18 mm, 20 mm; and only two patients (16.7%) with sequential 18 mm, 20 mm, and 22 mm balloon sizing were performed, respectively. According to the results of supra-annular assessment, a smaller device size (91.7%) was selected in all but one patient compared with annulus based sizing strategy, and the outcomes were satisfactory with 100% procedural success. No mortality and 1 minor stroke were observed at 30 d follow-up. The percentage of NYHA III/IV decreased from 83.3% (9/12) to 16.7% (2/12). No new permanent pacemaker implantation and no moderate or severe paravalvular leakage were found. A supra-annular structure based sizing strategy is feasible for TAVR in patients with bicuspid AS. © 2018 The Authors Catheterization and Cardiovascular Interventions Published by Wiley Periodicals, Inc.

Foot pronation is not associated with increased injury risk in novice runners wearing a neutral shoe : a 1-year prospective cohort study

NARCIS (Netherlands)

Nielsen, Rasmus Oestergaard; Buist, Ida; Parner, Erik Thorlund; Nohr, Ellen Aagaard; Sorensen, Henrik; Lind, Martin; Rasmussen, Sten

Objective To investigate if running distance to first running-related injury varies between foot postures in novice runners wearing neutral shoes. Design A 1-year epidemiological observational prospective cohort study. Setting Denmark. Participants A total of 927 novice runners equivalent to 1854

The extended Price equation quantifies species selection on mammalian body size across the Palaeocene/Eocene Thermal Maximum.

Science.gov (United States)

Rankin, Brian D; Fox, Jeremy W; Barrón-Ortiz, Christian R; Chew, Amy E; Holroyd, Patricia A; Ludtke, Joshua A; Yang, Xingkai; Theodor, Jessica M

2015-08-07

Species selection, covariation of species' traits with their net diversification rates, is an important component of macroevolution. Most studies have relied on indirect evidence for its operation and have not quantified its strength relative to other macroevolutionary forces. We use an extension of the Price equation to quantify the mechanisms of body size macroevolution in mammals from the latest Palaeocene and earliest Eocene of the Bighorn and Clarks Fork Basins of Wyoming. Dwarfing of mammalian taxa across the Palaeocene/Eocene Thermal Maximum (PETM), an intense, brief warming event that occurred at approximately 56 Ma, has been suggested to reflect anagenetic change and the immigration of small bodied-mammals, but might also be attributable to species selection. Using previously reconstructed ancestor-descendant relationships, we partitioned change in mean mammalian body size into three distinct mechanisms: species selection operating on resident mammals, anagenetic change within resident mammalian lineages and change due to immigrants. The remarkable decrease in mean body size across the warming event occurred through anagenetic change and immigration. Species selection also was strong across the PETM but, intriguingly, favoured larger-bodied species, implying some unknown mechanism(s) by which warming events affect macroevolution. © 2015 The Author(s).

Size-selective predation and predator-induced life-history shifts alter the outcome of competition between planktonic grazers

NARCIS (Netherlands)

Hülsmann, S.; Rinke, K.; Mooij, W.M.

2011-01-01

1.We studied the effect of size-selective predation on the outcome of competition between two differently sized prey species in a homogenous environment. 2. Using a physiologically structured population model, we calculated equilibrium food concentrations for a range of predation scenarios defined

Effect of Inoculant Alloy Selection and Particle Size on Efficiency of Isomorphic Inoculation of Ti-Al.

Science.gov (United States)

Kennedy, J R; Rouat, B; Daloz, D; Bouzy, E; Zollinger, J

2018-04-25

The process of isomorphic inoculation relies on precise selection of inoculant alloys for a given system. Three alloys, Ti-10Al-25Nb, Ti-25Al-10Ta, and Ti-47Ta (at %) were selected as potential isomorphic inoculants for a Ti-46Al alloy. The binary Ti-Ta alloy selected was found to be ineffective as an inoculant due to its large density difference with the melt, causing the particles to settle. Both ternary alloys were successfully implemented as isomorphic inoculants that decreased the equiaxed grain size and increased the equiaxed fraction in their ingots. The degree of grain refinement obtained was found to be dependent on the number of particles introduced to the melt. Also, more new grains were formed than particles added to the melt. The grains/particle efficiency varied from greater than one to nearly twenty as the size of the particle increased. This is attributed to the breaking up of particles into smaller particles by dissolution in the melt. For a given particle size, Ti-Al-Ta and Ti-Al-Nb particles were found to have a roughly similar grain/particle efficiency.

Evolution of floral display in Eichhornia paniculata (Pontederiaceae): direct and correlated responses to selection on flower size and number.

Science.gov (United States)

Worley, A C; Barrett, S C

2000-10-01

Trade-offs between flower size and number seem likely to influence the evolution of floral display and are an important assumption of several theoretical models. We assessed floral trade-offs by imposing two generations of selection on flower size and number in a greenhouse population of bee-pollinated Eichhornia paniculata. We established a control line and two replicate selection lines of 100 plants each for large flowers (S+), small flowers (S-), and many flowers per inflorescence (N+). We compared realized heritabilities and genetic correlations with estimates based on restricted-maximum-likelihood (REML) analysis of pedigrees. Responses to selection confirmed REML heritability estimates (flower size, h2 = 0.48; daily flower number, h2 = 0.10; total flower number, h2 = 0.23). Differences in nectar, pollen, and ovule production between S+ and S- lines supported an overall divergence in investment per flower. Both realized and REML estimates of the genetic correlation between daily and total flower number were r = 1.0. However, correlated responses to selection were inconsistent in their support of a trade-off. In both S- lines, correlated increases in flower number indicated a genetic correlation of r = -0.6 between flower size and number. In contrast, correlated responses in N+ and S+ lines were not significant, although flower size decreased in one N+ line. In addition, REML estimates of genetic correlations between flower size and number were positive, and did not differ from zero when variation in leaf area and age at first flowering were taken into account. These results likely reflect the combined effects of variation in genes controlling the resources available for flowering and genes with opposing effects on flower size and number. Our results suggest that the short-term evolution of floral display is not necessarily constrained by trade-offs between flower size and number, as is often assumed.

Self-selection in size and structure in argon clusters formed on amorphous carbon

Energy Technology Data Exchange (ETDEWEB)

Krainyukova, Nina V.; Waal, Benjamin W. van de

2004-07-01

Argon clusters formed on an amorphous carbon substrate as deposited from the vapor phase were studied by means of transmission high energy electron diffraction using the liquid helium cryostat. Electron diffractograms were analysed on the basis of assumption that there exist a cluster size distribution in samples formed on substrate and multi-shell structures such as icosahedra, decahedra, fcc and hcp were probed for different sizes up to {approx}15 000 atoms. The experimental data were considered as a result of a superposition of diffracted intensities from clusters of different sizes and structures. The comparative analysis was based on the R-factor minimization that was found to be equal to 0.014 for the best fit between experiment and modelling. The total size and structure distribution function shows the presence of 'non-crystallographic' structures such as icosahedra and decahedra with five-fold symmetry that was found to prevail and a smaller amount of fcc and hcp structures. Possible growth mechanisms as well as observed general tendency to self-selection in sizes and structures are presumably governed by confined pore-like geometry in an amorphous carbon substrate.

Effects of shoe sole geometry on toe clearance and walking stability in older adults.

Science.gov (United States)

Thies, S B; Price, C; Kenney, L P J; Baker, R

2015-07-01

Thirty-five percent of people above age 65 fall each year, and half of their falls are associated with tripping: tripping, an apparently 'mundane' everyday problem, therefore, significantly impacts on older people's health and associated medical costs. To avoid tripping and subsequent falling, sufficient toe clearance during the swing phase is crucial. We previously found that a rocker-shaped shoe sole enhances toe clearance in young adults, thereby decreasing their trip-risk. This study investigates whether such sole design also enhances older adults' toe clearance, without inadvertently affecting their walking stability. Toe clearance and its variability are reported together with measures of walking stability for twelve older adults, walking in shoes with rocker angles of 10°, 15°, and 20°. Surface inclinations (flat, incline, decline) were chosen to reflect a potential real-world environment. Toe clearance increased substantially from the 10° to the 15° rocker angle (p=0.003) without compromising measures of walking stability (p>0.05). A further increase in rocker angle to 20° resulted in less substantial enhancement of toe clearance and came at the cost of a decrease in gait speed on the decline. The novelty of this investigation lies in the exploration of the trade-off between reduction of trip-risk through footwear design and adverse effects on walking stability on real-life relevant surfaces. Our two studies suggest that the current focus on slip-resistance in footwear design may need to be generalised to include other factors that affect trip-risk. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

A simulation-based attempt to quantify the morphological component of size selection of Nephrops norvegicus in trawl codends

DEFF Research Database (Denmark)

Frandsen, Rikke; Herrmann, Bent; Madsen, Niels

2010-01-01

The selectivity for Nephrops (Nephrops norvegicus) in trawl codends generally is poor and the lack of steepness of the selection curve results in high discard rates and/or loss of legal-sized catch. This poor codend selectivity often is attributed to the irregular shape of Nephrops, which to some...

Selection Of Suitable Particle Size And Particle Ratio For Japanese Cucumber Cucumis Sativus L. Plants

Directory of Open Access Journals (Sweden)

Galahitigama GAH

2015-08-01

Full Text Available This study was conducted to select the best particle size of coco peat for cucumber nurseries as well as best particle ratio for optimum plant growth and development of cucumber. The experiment was carried out in International Foodstuff Company and Faculty of Agriculture University of Ruhuna Sri Lanka during 2015 to 2016. Under experiment one three types of different particle sizes were used namely fine amp88040.5mm T2 medium 3mm-0.5mm T3 and coarse 4mm T4 with normal coco peat T1 as treatments. Complete Randomized Design CRD used as experimental design with five replicates. Germination percentage number of leaves per seedling seedling height in frequent day intervals was taken as growth parameters. Analysis of variance procedure was applied to analyze the data at 5 probability level. The results revealed that medium size particle media sieve size 0.5mm -3mm of coco peat was the best particle size for cucumber nursery practice when considered the physical and chemical properties of medium particles of coco peat. In the experiment of selecting of suitable particle ratio for cucumber plants the compressed mixture of coco peat particles that contain 70 ww unsieved coco peat 20 ww coarse particles and 10 ww coconut husk chips 5 12mm has given best results for growth performances compared to other treatments and cucumber grown in this mixture has shown maximum growth and yield performances.

Selection for altruism through random drift in variable size populations

Directory of Open Access Journals (Sweden)

Houchmandzadeh Bahram

2012-05-01

Full Text Available Abstract Background Altruistic behavior is defined as helping others at a cost to oneself and a lowered fitness. The lower fitness implies that altruists should be selected against, which is in contradiction with their widespread presence is nature. Present models of selection for altruism (kin or multilevel show that altruistic behaviors can have ‘hidden’ advantages if the ‘common good’ produced by altruists is restricted to some related or unrelated groups. These models are mostly deterministic, or assume a frequency dependent fitness. Results Evolutionary dynamics is a competition between deterministic selection pressure and stochastic events due to random sampling from one generation to the next. We show here that an altruistic allele extending the carrying capacity of the habitat can win by increasing the random drift of “selfish” alleles. In other terms, the fixation probability of altruistic genes can be higher than those of a selfish ones, even though altruists have a smaller fitness. Moreover when populations are geographically structured, the altruists advantage can be highly amplified and the fixation probability of selfish genes can tend toward zero. The above results are obtained both by numerical and analytical calculations. Analytical results are obtained in the limit of large populations. Conclusions The theory we present does not involve kin or multilevel selection, but is based on the existence of random drift in variable size populations. The model is a generalization of the original Fisher-Wright and Moran models where the carrying capacity depends on the number of altruists.

Selection of the Maximum Spatial Cluster Size of the Spatial Scan Statistic by Using the Maximum Clustering Set-Proportion Statistic.

Science.gov (United States)

Ma, Yue; Yin, Fei; Zhang, Tao; Zhou, Xiaohua Andrew; Li, Xiaosong

2016-01-01

Spatial scan statistics are widely used in various fields. The performance of these statistics is influenced by parameters, such as maximum spatial cluster size, and can be improved by parameter selection using performance measures. Current performance measures are based on the presence of clusters and are thus inapplicable to data sets without known clusters. In this work, we propose a novel overall performance measure called maximum clustering set-proportion (MCS-P), which is based on the likelihood of the union of detected clusters and the applied dataset. MCS-P was compared with existing performance measures in a simulation study to select the maximum spatial cluster size. Results of other performance measures, such as sensitivity and misclassification, suggest that the spatial scan statistic achieves accurate results in most scenarios with the maximum spatial cluster sizes selected using MCS-P. Given that previously known clusters are not required in the proposed strategy, selection of the optimal maximum cluster size with MCS-P can improve the performance of the scan statistic in applications without identified clusters.

Selection based on the size of the black tie of the great tit may be reversed in urban habitats.

Science.gov (United States)

Senar, Juan Carlos; Conroy, Michael J; Quesada, Javier; Mateos-Gonzalez, Fernando

2014-07-01

A standard approach to model how selection shapes phenotypic traits is the analysis of capture-recapture data relating trait variation to survival. Divergent selection, however, has never been analyzed by the capture-recapture approach. Most reported examples of differences between urban and nonurban animals reflect behavioral plasticity rather than divergent selection. The aim of this paper was to use a capture-recapture approach to test the hypothesis that divergent selection can also drive local adaptation in urban habitats. We focused on the size of the black breast stripe (i.e., tie width) of the great tit (Parus major), a sexual ornament used in mate choice. Urban great tits display smaller tie sizes than forest birds. Because tie size is mostly genetically determined, it could potentially respond to selection. We analyzed capture/recapture data of male great tits in Barcelona city (N = 171) and in a nearby (7 km) forest (N = 324) from 1992 to 2008 using MARK. When modelling recapture rate, we found it to be strongly influenced by tie width, so that both for urban and forest habitats, birds with smaller ties were more trap-shy and more cautious than their larger tied counterparts. When modelling survival, we found that survival prospects in forest great tits increased the larger their tie width (i.e., directional positive selection), but the reverse was found for urban birds, with individuals displaying smaller ties showing higher survival (i.e., directional negative selection). As melanin-based tie size seems to be related to personality, and both are heritable, results may be explained by cautious personalities being favored in urban environments. More importantly, our results show that divergent selection can be an important mechanism in local adaptation to urban habitats and that capture-recapture is a powerful tool to test it.

Establishing state of motion through two-dimensional foot and shoe print analysis: A pilot study.

Science.gov (United States)

Neves, Fernando Bueno; Arnold, Graham P; Nasir, Sadiq; Wang, Weijie; MacDonald, Calum; Christie, Ian; Abboud, Rami J

2018-03-01

According to the College of Podiatry, footprints rank among the most frequent forms of evidence found at crime scenes, and the recent ascension of forensic podiatry reflects the importance of footwear and barefoot traces in contemporary forensic practice. In this context, this pilot study focused on whether it is possible to distinguish between walking and running states using parameters derived from two-dimensional foot or shoe prints. Eleven subjects moved along four tracks (barefoot walking; barefoot running; footwear walking; footwear running) while having their bare feet or footwear stained with artificial blood and their footstep patterns recorded. Contact stains and associated bloodstain patterns were collected, and body movements were recorded through three-dimensional motion capture. Barefoot walking prints were found to be larger than barefoot static prints (1.789±0.481cm; pprints (0.635±0.405cm; p=0.006). No correlation was observed for footwear prints. Running trials were more associated with the presence of both passive and cast off stains than walking trials, and the quantity of additional associated stains surrounding individual foot and shoe prints was also higher in running states. Furthermore, a previously proposed equation predicted speed with a high degree of accuracy (within 6%) and may be used for clinical assessment of walking speed. Contact stains, associated bloodstain patterns and stride length measurements may serve to ascertain state of motion in real crime scene scenarios, and future studies may be capable of designing statistical frameworks which could be used in courts of law. Copyright © 2018 Elsevier B.V. All rights reserved.

Ethylbenzene Disproportionation on HZSM-5 Zeolite : The Effect of Aluminum Content and Crystal Size on the Selectivity for p-Diethylbenzene

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Velasco N.D.

1998-01-01

Full Text Available The aim of this work was to verify the effect of MFI aluminum content and crystal size on the selectivity for para-diethylbenzene during ethylbenzene disproportionation. It was observed that the para-diethylbenzene selectivity increased as MFI crystal size increased. The increase in aluminum content caused a decrease in the selectivity for para-diethylbenzene. However, for crystals larger than 8 m m, the decrease in aluminum content had little influence on the selectivity for para-diethylbenzene. The results can be explained by the number of active aluminum sites on the external surface of the crystals.

Evidence of market-driven size-selective fishing and the mediating effects of biological and institutional factors.

Science.gov (United States)

Reddy, Sheila M W; Wentz, Allison; Aburto-Oropeza, Octavio; Maxey, Martin; Nagavarapu, Sriniketh; Leslie, Heather M

2013-06-01

Market demand is often ignored or assumed to lead uniformly to the decline of resources. Yet little is known about how market demand influences natural resources in particular contexts, or the mediating effects of biological or institutional factors. Here, we investigate this problem by examining the Pacific red snapper (Lutjanus peru) fishery around La Paz, Mexico, where medium or "plate-sized" fish are sold to restaurants at a premium price. If higher demand for plate-sized fish increases the relative abundance of the smallest (recruit size class) and largest (most fecund) fish, this may be a market mechanism to increase stocks and fishermen's revenues. We tested this hypothesis by estimating the effect of prices on the distribution of catch across size classes using daily records of prices and catch. We linked predictions from this economic choice model to a staged-based model of the fishery to estimate the effects on the stock and revenues from harvest. We found that the supply of plate-sized fish increased by 6%, while the supply of large fish decreased by 4% as a result of a 13% price premium for plate-sized fish. This market-driven size selection increased revenues (14%) but decreased total fish biomass (-3%). However, when market-driven size selection was combined with limited institutional constraints, both fish biomass (28%) and fishermen's revenue (22%) increased. These results show that the direction and magnitude of the effects of market demand on biological populations and human behavior can depend on both biological attributes and institutional constraints. Fisheries management may capitalize on these conditional effects by implementing size-based regulations when economic and institutional incentives will enhance compliance, as in the case we describe here, or by creating compliance enhancing conditions for existing regulations.

Effect of Group-Selection Opening Size on Breeding Bird Habitat Use in a Bottomland Forest

Energy Technology Data Exchange (ETDEWEB)

Moorman, C.E.; D.C. Guynn, Jr.

2001-12-01

Research on the effects of creating group-selection openings of various sizes on breeding birds habitat use in a bottomland hardwood forest of the Upper Coastal Plain of South Carolina. Creation of 0.5-ha group selection openings in southern bottomland forests should provide breeding habitat for some field-edge species in gaps and habitat for forest-interior species and canopy-dwelling forest-edge species between gaps provided that enough mature forest is made available.

The shoelace book a mathematical guide to the best (and worst) ways to lace your shoes

CERN Document Server

Polster, Burkard

2006-01-01

Crisscross, zigzag, bowtie, devil, angel, or star: which are the longest, the shortest, the strongest, and the weakest lacings? Pondering the mathematics of shoelaces, the author paints a vivid picture of the simple, beautiful, and surprising characterizations of the most common shoelace patterns. The mathematics involved is an attractive mix of combinatorics and elementary calculus. This book will be enjoyed by mathematically minded people for as long as there are shoes to lace. Burkard Polster is a well-known mathematical juggler, magician, origami expert, bubble-master, shoelace charmer, an

Sedimentation and the Economics of Selecting an Optimum Reservoir Size

Science.gov (United States)

Miltz, David; White, David C.

1987-08-01

This paper attempts to develop an easily reproducible methodology for the economic selection of an optimal reservoir size given an annual sedimentation rate. The optimal capacity is that at which the marginal cost of constructing additional storage capacity is equal to the dredging costs avoided by having that additional capacity available to store sediment. The cost implications of misestimating dredging costs, construction costs, and sediment delivery rates are investigated. In general, it is shown that oversizing is a rational response to uncertainty in the estimation of parameters. The sensitivity of the results to alternative discount rates is also discussed. The theoretical discussion is illustrated with a case study drawn from Highland Silver Lake in southwestern Illinois.

Size-controlled sensitivity and selectivity for the fluorometric detection of Ag+ by homocysteine capped CdTe quantum dots

International Nuclear Information System (INIS)

Jiao, Hangzhou; Liang, Zhenhua; Peng, Guihua; Zhang, Ling; Lin, Hengwei

2014-01-01

We have synthesized water dispersible CdTe quantum dots (QDs) in different sizes and with various capping reagents, and have studied the effects of their size on the sensitivity and selectivity in the fluorometric determination of metal ions, particularly of silver(I). It is found that an increase in the particle size of homocysteine-capped CdTe QDs from 1.7 nm to 3.3 nm and to 3.7 nm enhances both the sensitivity and selectivity of the determination of Ag(I) to give an ultimate limit of detection as low as 8.3 nM. This effect can partially be explained by the better passivation of surface traps on smaller sized QDs via adsorption of Ag(I), thereby decreasing the apparent detection efficiency. In addition, the presence of CdS in the CdTe QDs is likely to play a role. The study demonstrates that an improvement in sensing performance is accomplished by using QDs of fine-tuned particle sizes. Such effects are likely also to occur with other QD-based optical probes. (author)

Effectiveness of a long-term use of a minimalist footwear versus habitual shoe on pain, function and mechanical loads in knee osteoarthritis: a randomized controlled trial.

Science.gov (United States)

Trombini-Souza, Francis; Fuller, Ricardo; Matias, Alessandra; Yokota, Mariane; Butugan, Marco; Goldenstein-Schainberg, Claudia; Sacco, Isabel C N

2012-07-12

Recent studies have shown an important reduction of joint overload during locomotion in elderly women with knee osteoarthritis (OA) after short-term use of minimalist shoes. Our aim is to investigate the chronic effect of inexpensive and minimalist footwear on the clinical and functional aspects of OA and gait biomechanics of elderly women with knee OA. Fifty-six elderly women with knee OA grade 2 or 3 (Kellgren and Lawrence) are randomized into blocks and allocated to either the intervention group, which will use flexible, non-heeled shoes- Moleca®-for six months for at least six hours daily, or the control group, which could not use these shoes. Neither group is undergoing physical therapy treatment throughout the intervention period. Moleca® is a women's double canvas, flexible, flat walking shoe without heels, with a 5-mm anti-slip rubber sole and a 3-mm internal wedge of ethylene vinyl acetate. Both groups will be followed for six months and will be assessed at baseline condition, after three months, and after six months (end of intervention). All the assessments will be performed by a physiotherapist that is blind to the group allocation. The primary outcome is the pain Western Ontario and McMaster Universities Osteoarthritis (WOMAC) score. The secondary outcomes are global WOMAC score; joint stiffness and disability WOMAC scores; knee pain with a visual analogue scale; walking distance in the six-minute walk test; Lequesne score; amount and frequency (number of days) of paracetamol (500 mg) intake over six months; knee adduction moment during gait; global medical assessment score; and global patient auto-assessment score. At baseline, all patients receive a diary to record the hours of daily use of the footwear intervention; every two weeks, the same physiotherapist makes phone calls to all patients in order to verify adherence to treatment. The statistical analysis will be based on intention-to-treat analysis, as well as general linear models of

Evidence of market-driven size-selective fishing and the mediating effects of biological and institutional factors

Science.gov (United States)

Reddy, Sheila M. W.; Wentz, Allison; Aburto-Oropeza, Octavio; Maxey, Martin; Nagavarapu, Sriniketh; Leslie, Heather M.

2014-01-01

Market demand is often ignored or assumed to lead uniformly to the decline of resources. Yet little is known about how market demand influences natural resources in particular contexts, or the mediating effects of biological or institutional factors. Here, we investigate this problem by examining the Pacific red snapper (Lutjanus peru) fishery around La Paz, Mexico, where medium or “plate-sized” fish are sold to restaurants at a premium price. If higher demand for plate-sized fish increases the relative abundance of the smallest (recruit size class) and largest (most fecund) fish, this may be a market mechanism to increase stocks and fishermen’s revenues. We tested this hypothesis by estimating the effect of prices on the distribution of catch across size classes using daily records of prices and catch. We linked predictions from this economic choice model to a staged-based model of the fishery to estimate the effects on the stock and revenues from harvest. We found that the supply of plate-sized fish increased by 6%, while the supply of large fish decreased by 4% as a result of a 13% price premium for plate-sized fish. This market-driven size selection increased revenues (14%) but decreased total fish biomass (−3%). However, when market-driven size selection was combined with limited institutional constraints, both fish biomass (28%) and fishermen’s revenue (22%) increased. These results show that the direction and magnitude of the effects of market demand on biological populations and human behavior can depend on both biological attributes and institutional constraints. Fisheries management may capitalize on these conditional effects by implementing size-based regulations when economic and institutional incentives will enhance compliance, as in the case we describe here, or by creating compliance enhancing conditions for existing regulations. PMID:23865225

ERGONOMIC WORK ANALYSIS APPLICATION IN A SMALL SHOE BUSINESS

Directory of Open Access Journals (Sweden)

Aline Marian Callegaro

2013-11-01

Full Text Available This paper aims to presentthe results after conducting an Ergonomic Work Analysis (EWA in a smallbusiness located in Porto Alegre. The ergonomic intervention was performed basedon Guérin et al. (2001 and aimed to analyze the process organization and thelayout of the shoemaker workstations to provide improvements to these areas.The starting point was the account of the small shoe business owner’s need hadto hire one more shoemaker without increasing the company physical space. The EWAwas used focusing the work organization, how the flow of information ran fromthe entry of an order to the final stage of the product repairing. Thediagnosis showed the company main problems were related to the shop assistantsdependence on the shoemakers to provide budget information and delivery time tocustomers and the layout organization. Among the results, a temporal analysisof two company recurrent tasks was performed in order to ascertain possiblelosses related to the displacement and the search for material. A new layoutscheme was also proposed, aiming to organize the work stations, making easierthe stock, tools and equipment removal, providing a free space to make possiblethe hiring of the new shoemakers within the current company boundaries.

Why forefoot striking in minimal shoes might positively change the course of running injuries

Directory of Open Access Journals (Sweden)

Irene S. Davis

2017-06-01

Full Text Available It is believed that human ancestors evolved the ability to run bipedally approximately 2 million years ago. This form of locomotion may have been important to our survival and likely has influenced the evolution of our body form. As our bodies have adapted to run, it seems unusual that up to 79% of modern day runners are injured annually. The etiology of these injuries is clearly multifactorial. However, 1 aspect of running that has significantly changed over the past 50 years is the footwear we use. Modern running shoes have become increasingly cushioned and supportive, and have changed the way we run. In particular, they have altered our footstrike pattern from a predominantly forefoot strike (FFS landing to a predominantly rearfoot strike (RFS landing. This change alters the way in which the body is loaded and may be contributing to the high rate of injuries runners experience while engaged in an activity for which they were adapted. In this paper, we will examine the benefits of barefoot running (typically an FFS pattern, and compare the lower extremity mechanics between FFS and RFS. The implications of these mechanical differences, in terms of injury, will be discussed. We will then provide evidence to support our contention that FFS provides an optimal mechanical environment for specific foot and ankle structures, such as the heel pad, the plantar fascia, and the Achilles tendon. The importance of footwear will then be addressed, highlighting its interaction with strike pattern on mechanics. This analysis will underscore why footwear matters when assessing mechanics. Finally, proper preparation and safe transition to an FFS pattern in minimal shoes will be emphasized. Through the discussion of the current literature, we will develop a justification for returning to running in the way for which we were adapted to reduce running-related injuries.

Impact of payroll taxes for small shoe manufacturing enterprises profit generation in Bogota city 15th district

Directory of Open Access Journals (Sweden)

José Armando Hernández Bernal

2016-04-01

Full Text Available In this paper we illustrate the financial difficulties that payroll taxes would impose on small shoe manufacturing enterprises in Bogota City 15th district and how this would impose some restrictions for firms profit generation, when such contributions turns out to be a fixed cost. We present a brief on the legal framework as well as an econometric exercise that shows the relations between labor costs and profit generation for the footwear industry in the 15th urban district of Bogotá city.

ZResponse to selection, heritability and genetic correlations between body weight and body size in Pacific white shrimp, Litopenaeus vannamei

Science.gov (United States)

Andriantahina, Farafidy; Liu, Xiaolin; Huang, Hao; Xiang, Jianhai

2012-03-01

To quantify the response to selection, heritability and genetic correlations between weight and size of Litopenaeus vannamei, the body weight (BW), total length (TL), body length (BL), first abdominal segment depth (FASD), third abdominal segment depth (TASD), first abdominal segment width (FASW), and partial carapace length (PCL) of 5-month-old parents and of offspnng were measured by calculating seven body measunngs of offspnng produced by a nested mating design. Seventeen half-sib families and 42 full-sib families of L. vannamei were produced using artificial fertilization from 2-4 dams by each sire, and measured at around five months post-metamorphosis. The results show that hentabilities among vanous traits were high: 0.515±0.030 for body weight and 0.394±0.030 for total length. After one generation of selection. the selection response was 10.70% for offspring growth. In the 5th month, the realized heritability for weight was 0.296 for the offspnng generation. Genetic correlations between body weight and body size were highly variable. The results indicate that external morphological parameters can be applied dunng breeder selection for enhancing the growth without sacrificing animals for determining the body size and breed ability; and selective breeding can be improved significantly, simultaneously with increased production.

Effect of directional selection for body size on fluctuating asymmetry in certain morphological traits in Drosophila ananassae.

Science.gov (United States)

Vishalakshi, C; Singh, B N

2009-06-01

Variation in the subtle differences between the right and left sides of bilateral characters or fluctuating asymmetry (FA) has been considered as an indicator of an organism's ability to cope with genetic and environmental stresses during development. However, due to inconsistency in the results of empirical studies, the relationship between FA and stress has been the subject of intense debate. In this study, we investigated whether stress caused by artificial bidirectional selection for body size has any effect on the levels of FA of different morphological traits in Drosophila ananassae. The realised heritability (h2) was higher in low-line females and high-line males, which suggests an asymmetrical response to selection for body size. Further, the levels of FA were compared across 10 generations of selection in different selection lines in both sexes for sternopleural bristle number, wing length, wing-to-thorax ratio, sex combtooth number and ovariole number. The levels of FA differed significantly among generations and selection lines but did not change markedly with directional selection. However, the levels of FA were higher in the G10 generation (at the end of selection) than G0 (at the start of selection) but lower than the G5 generation in different selection lines, suggesting that the levels of FA are not affected by the inbreeding generated during the course of selection. Also, the levels of FA in the hybrids of high and low lines were signifi cantly lower than the parental selection lines, suggesting that FA is influenced by hybridisation. These results are discussed in the framework of the literature available on FA and its relationship with stress.

A Direct Method for Mapping the Center of Pressure Measured by an Insole Pressure Sensor System to the Shoe's Local Coordinate System.

Science.gov (United States)

Weaver, Brian T; Braman, Jerrod E; Haut, Roger C

2016-06-01

A direct method to express the center of pressure (CoP) measured by an insole pressure sensor system (IPSS) into a known coordinate system measured by motion tracking equipment is presented. A custom probe was constructed with reflective markers to allow its tip to be precisely tracked with motion tracking equipment. This probe was utilized to activate individual sensors on an IPSS that was placed in a shoe fitted with reflective markers used to establish a local shoe coordinate system. When pressed onto the IPSS the location of the probe's tip was coincident with the CoP measured by the IPSS (IPSS-CoP). Two separate pushes (i.e., data points) were used to develop vectors in each respective coordinate system. Simple vector mathematics determined the rotational and translational components of the transformation matrix needed to express the IPSS-CoP into the local shoe coordinate system. Validation was performed by comparing IPSS-CoP with an embedded force plate measured CoP (FP-CoP) from data gathered during kinematic trials. Six male subjects stood on an embedded FP and performed anterior/posterior (AP) sway, internal rotation, and external rotation of the body relative to a firmly planted foot. The IPSS-CoP was highly correlated with the FP-CoP for all motions, root mean square errors (RMSRRs) were comparable to other research, and there were no statistical differences between the displacement of the IPSS-CoP and FP-CoP for both the AP and medial/lateral (ML) axes, respectively. The results demonstrated that this methodology could be utilized to determine the transformation variables need to express IPSS-CoP into a known coordinate system measured by motion tracking equipment and that these variables can be determined outside the laboratory anywhere motion tracking equipment is available.

The necessity of microscopy to characterize the optical properties of size-selected, nonspherical aerosol particles.

Science.gov (United States)

Veghte, Daniel P; Freedman, Miriam A

2012-11-06

It is currently unknown whether mineral dust causes a net warming or cooling effect on the climate system. This uncertainty stems from the varied and evolving shape and composition of mineral dust, which leads to diverse interactions of dust with solar and terrestrial radiation. To investigate these interactions, we have used a cavity ring-down spectrometer to study the optical properties of size-selected calcium carbonate particles, a reactive component of mineral dust. The size selection of nonspherical particles like mineral dust can differ from spherical particles in the polydispersity of the population selected. To calculate the expected extinction cross sections, we use Mie scattering theory for monodisperse spherical particles and for spherical particles with the polydispersity observed in transmission electron microscopy images. Our results for calcium carbonate are compared to the well-studied system of ammonium sulfate. While ammonium sulfate extinction cross sections agree with Mie scattering theory for monodisperse spherical particles, the results for calcium carbonate deviate at large and small particle sizes. We find good agreement for both systems, however, between the calculations performed using the particle images and the cavity ring-down data, indicating that both ammonium sulfate and calcium carbonate can be treated as polydisperse spherical particles. Our results indicate that having an independent measure of polydispersity is essential for understanding the optical properties of nonspherical particles measured with cavity ring-down spectroscopy. Our combined spectroscopy and microscopy techniques demonstrate a novel method by which cavity ring-down spectroscopy can be extended for the study of more complex aerosol particles.

In search of genetic constraints limiting the evolution of egg size: direct and correlated responses to artificial selection on a prenatal maternal effector.

Science.gov (United States)

Pick, J L; Hutter, P; Tschirren, B

2016-06-01

Maternal effects are an important force in nature, but the evolutionary dynamics of the traits that cause them are not well understood. Egg size is known to be a key mediator of prenatal maternal effects with an established genetic basis. In contrast to theoretical expectations for fitness-related traits, there is a large amount of additive genetic variation in egg size observed in natural populations. One possible mechanism for the maintenance of this variation is through genetic constraints caused by a shared genetic basis among traits. Here we created replicated, divergent selection lines for maternal egg investment in Japanese quail (Coturnix japonica) to quantify the role of genetic constraints in the evolution of egg size. We found that egg size responds rapidly to selection, accompanied by a strong response in all egg components. Initially, we observed a correlated response in body size, but this response declined over time, showing that egg size and body size can evolve independently. Furthermore, no correlated response in fecundity (measured as the proportion of days on which a female laid an egg) was observed. However, the response to selection was asymmetrical, with egg size plateauing after one generation of selection in the high but not the low investment lines. We attribute this pattern to the presence of genetic asymmetries, caused by directional dominance or unequal allele frequencies. Such asymmetries may contribute to the evolutionary stasis in egg size observed in natural populations, despite a positive association between egg size and fitness.

Linear and nonlinear surface spectroscopy of supported size selected metal clusters and organic adsorbates

Energy Technology Data Exchange (ETDEWEB)

Thaemer, Martin Georg

2012-03-08

The spectroscopic investigation of supported size selected metal clusters over a wide wavelength range plays an important role for understanding their outstanding catalytic properties. The challenge which must be overcome to perform such measurements is the difficult detection of the weak spectroscopic signals from these samples. As a consequence, highly sensitive spectroscopic methods are applied, such as surface Cavity Ringdown Spectroscopy and surface Second Harmonic Generation Spectroscopy. The spectroscopic apparatus developed is shown to have a sensitivity which is high enough to detect sub-monolayer coverages of adsorbates on surfaces. In the measured spectra of small supported silver clusters of the sizes Ag{sub 4}2, Ag{sub 2}1, Ag{sub 9}, and Ag atoms a stepwise transition from particles with purely metallic character to particles with molecule-like properties can be observed within this size range.

Cyclohexane selective photocatalytic oxidation by anatase TiO2: influence of particle size and crystallinity

NARCIS (Netherlands)

Carneiro, J.T.; Carneiro, Joana T.; Almeida, A.R.; Almeida, Ana R.; Moulijn, Jacob A.; Mul, Guido

2010-01-01

A systematic study is presented on the effect of crystallite size of Anatase (Hombikat, Sachtleben), varied by calcination at different temperatures up to 800 °C, on photocatalytic activity in cyclohexane selective oxidation. Two different reactors were used to test the materials: a top illumination

Effect of shoe heel height on vastus medialis and vastus lateralis electromyographic activity during sit to stand

Directory of Open Access Journals (Sweden)

Hodgson David

2008-01-01

Full Text Available Abstract Background It has been proposed that high-heeled shoes may contribute to the development and progression of knee pain. However, surprisingly little research has been carried out on how shoe heel height affects muscle activity around the knee joint. The purpose of this study was to investigate the effect of differing heel height on the electromyographic (EMG activity in vastus medialis (VM and vastus lateralis (VL during a sit to stand activity. This was an exploratory study to inform future research. Methods A repeated measures design was used. Twenty five healthy females carried out a standardised sit to stand activity under 4 conditions; barefoot, and with heel wedges of 1, 3, and 5 cm in height. EMG activity was recorded from VM and VL during the activity. Data were analysed using 1 × 4 repeated measures ANOVA. Results Average rectified EMG activity differed with heel height in both VM (F2.2, 51.7 = 5.24, p 3, 72 = 5.32, p 3, 72 = 0.61, p = 0.609. Conclusion We found that as heel height increased, there was an increase in EMG activity in both VM and VL, but no change in the relative EMG intensity of VM and VL as measured by the VM: VL ratio. This showed that no VM: VL imbalance was elicited. This study provides information that will inform future research on how heel height affects muscle activity around the knee joint.

Bell-shaped size selection in a bottom trawl: A case study for Nephrops directed fishery with reduced catches of cod

DEFF Research Database (Denmark)

Lövgren, Johan; Herrmann, Bent; Feekings, Jordan P.

2016-01-01

and size selectivity have motivated the development of selective systems in trawl fisheries that utilize more than one selective device simultaneously. An example can be found in the Swedish demersal trawl fishery targeting Norway lobster (Nephrops norvegicus), which simultaneously aims at avoiding catches...

Model selection for semiparametric marginal mean regression accounting for within-cluster subsampling variability and informative cluster size.

Science.gov (United States)

Shen, Chung-Wei; Chen, Yi-Hau

2018-03-13

We propose a model selection criterion for semiparametric marginal mean regression based on generalized estimating equations. The work is motivated by a longitudinal study on the physical frailty outcome in the elderly, where the cluster size, that is, the number of the observed outcomes in each subject, is "informative" in the sense that it is related to the frailty outcome itself. The new proposal, called Resampling Cluster Information Criterion (RCIC), is based on the resampling idea utilized in the within-cluster resampling method (Hoffman, Sen, and Weinberg, 2001, Biometrika 88, 1121-1134) and accommodates informative cluster size. The implementation of RCIC, however, is free of performing actual resampling of the data and hence is computationally convenient. Compared with the existing model selection methods for marginal mean regression, the RCIC method incorporates an additional component accounting for variability of the model over within-cluster subsampling, and leads to remarkable improvements in selecting the correct model, regardless of whether the cluster size is informative or not. Applying the RCIC method to the longitudinal frailty study, we identify being female, old age, low income and life satisfaction, and chronic health conditions as significant risk factors for physical frailty in the elderly. © 2018, The International Biometric Society.

Value generation in the context of manufacturing strategy: an analysis in shoe manufactories

Directory of Open Access Journals (Sweden)

Sergio Evangelista Silva

2015-02-01

Full Text Available The manufacturing function has the role of provide to the customers products with generate value. However this task is not unique of this function, it has to work with the functions research and development (R&D and marketing and sales (M&S. This paper call these three functions as generating value functions, and discuss their mutual role in the process of generating value in the products of a firm. The validation of this model is performed by three comparative case studies, conducted in three shoe manufactories (SMs, with different value generation strategies. The empirical study shows that the mutual role of generating value functions in the value generating process, and that the configuration and the relative role of each function change according to the firm strategy followed.

Is portion size selection associated with expected satiation, perceived healthfulness or expected tastiness? A case study on pizza using a photograph-based computer task.

Science.gov (United States)

Labbe, D; Rytz, A; Godinot, N; Ferrage, A; Martin, N

2017-01-01

Increasing portion sizes over the last 30 years are considered to be one of the factors underlying overconsumption. Past research on the drivers of portion selection for foods showed that larger portions are selected for foods delivering low expected satiation. However, the respective contribution of expected satiation vs. two other potential drivers of portion size selection, i.e. perceived healthfulness and expected tastiness, has never been explored. In this study, we conjointly explored the role of expected satiation, perceived healthfulness and expected tastiness when selecting portions within a range of six commercial pizzas varying in their toppings and brands. For each product, 63 pizza consumers selected a portion size that would satisfy them for lunch and scored their expected satiation, perceived healthfulness and expected tastiness. As six participants selected an entire pizza as ideal portion independently of topping or brand, their data sets were not considered in the data analyses completed on responses from 57 participants. Hierarchical multiple regression analyses showed that portion size variance was predicted by perceived healthiness and expected tastiness variables. Two sub-groups of participants with different portion size patterns across pizzas were identified through post-hoc exploratory analysis. The explanatory power of the regression model was significantly improved by adding interaction terms between sub-group and expected satiation variables and between sub-group and perceived healthfulness variables to the model. Analysis at a sub-group level showed either positive or negative association between portion size and expected satiation depending on sub-groups. For one group, portion size selection was more health-driven and for the other, more hedonic-driven. These results showed that even when considering a well-liked product category, perceived healthfulness can be an important factor influencing portion size decision. Copyright © 2016

EXAFS study on structure of sulfide K-Co-Mo catalysts

International Nuclear Information System (INIS)

Bao Jun; Bian Guozhu; Fu Yilu; Liu Tao; Xie Yaning; Hu Tiandou

2002-01-01

Recently, authors prepared a kind of K-Co-Mo ultrafine particles by sol-gel method and it shoes much small particle size but higher activity and selectivity toward alcohol formation than the one prepared by conventional method. The aim of the present work is to research the microstructures of the Mo and Co species in the K-Co-Mo samples prepared by different method

Characterisation of Q and T steel pole shoes manufactured by sand casting; Charakterisierung mit Sandguss hergestellter Polschuhe aus verguetetem Stahl

Energy Technology Data Exchange (ETDEWEB)

Asensio-Lozano, J.; Alvarez-Antolin, J.F. [Oviedo Univ. (Spain). Dept. of Materials Science and Metallurgical Engineering; Panta-Mesones, J.T. [National Univ. of Trujillo, La Libertad (Peru). Faculty of Mines, Metallurgy and Materials; Vander-Voort, G.F. [Buehler Ltd., Lake Bluff, IL (United States)

2008-04-15

This paper presents a study of the microstructural and mechanical characterization of the GS 35 CrMoV 10 4 alloy employed in the manufacture of sand-cast pole shoes for 4-pole synchronous electric power generators working at a frequency of 60 Hz. In addition, the most appropriate treatment for ensuring compliance with the technical specifications defined in DIN Standard No. 1.7755 has been designed. (orig.)

Squamate hatchling size and the evolutionary causes of negative offspring size allometry.

Science.gov (United States)

Meiri, S; Feldman, A; Kratochvíl, L

2015-02-01

Although fecundity selection is ubiquitous, in an overwhelming majority of animal lineages, small species produce smaller number of offspring per clutch. In this context, egg, hatchling and neonate sizes are absolutely larger, but smaller relative to adult body size in larger species. The evolutionary causes of this widespread phenomenon are not fully explored. The negative offspring size allometry can result from processes limiting maximal egg/offspring size forcing larger species to produce relatively smaller offspring ('upper limit'), or from a limit on minimal egg/offspring size forcing smaller species to produce relatively larger offspring ('lower limit'). Several reptile lineages have invariant clutch sizes, where females always lay either one or two eggs per clutch. These lineages offer an interesting perspective on the general evolutionary forces driving negative offspring size allometry, because an important selective factor, fecundity selection in a single clutch, is eliminated here. Under the upper limit hypotheses, large offspring should be selected against in lineages with invariant clutch sizes as well, and these lineages should therefore exhibit the same, or shallower, offspring size allometry as lineages with variable clutch size. On the other hand, the lower limit hypotheses would allow lineages with invariant clutch sizes to have steeper offspring size allometries. Using an extensive data set on the hatchling and female sizes of > 1800 species of squamates, we document that negative offspring size allometry is widespread in lizards and snakes with variable clutch sizes and that some lineages with invariant clutch sizes have unusually steep offspring size allometries. These findings suggest that the negative offspring size allometry is driven by a constraint on minimal offspring size, which scales with a negative allometry. © 2014 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2014 European Society For Evolutionary

Orthosis-Shaped Sandals Are as Efficacious as In-Shoe Orthoses and Better than Flat Sandals for Plantar Heel Pain: A Randomized Control Trial.

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Bill Vicenzino

Full Text Available To investigate efficacy of a contoured sandal being marketed for plantar heel pain with comparison to a flat flip-flop and contoured in-shoe insert/orthosis.150 volunteers aged 50 (SD: 12 years with plantar heel pain (>4 weeks were enrolled after responding to advertisements and eligibility determined by telephone and at first visit. Participants were randomly allocated to receive commercially available contoured sandals (n = 49, flat flip-flops (n = 50 or over the counter, pre-fabricated full-length foot orthotics (n = 51. Primary outcomes were a 15-point Global Rating of Change scale (GROC: 1 = a very great deal worse, 15 = a very great deal better, 13 to 15 representing an improvement and the 20-item Lower Extremity Function Scale (LEFS on which participants rate 20 common weight bearing activities and activities of daily living on a 5-point scale (0 = extreme difficulty, 4 = no difficulty. Secondary outcomes were worst level of heel pain in the preceding week, and the foot and ankle ability measure. Outcomes were collected blind to allocation. Analyses were done on an intention to treat basis with 12 weeks being the primary outcome time of interest.The contoured sandal was 68% more likely to report improvement in terms of GROC compared to flat flip-flop. On the LEFS the contoured sandal was 61% more likely than flat flip-flop to report improvement. The secondary outcomes in the main reflected the primary outcomes, and there were no differences between contoured sandal and shoe insert.Physicians can have confidence in supporting a patient's decision to wear contoured sandals or in-shoe orthoses as one of the first and simple strategies to manage their heel pain.The Australian New Zealand Clinical Trials Registry ACTRN12612000463875.

Electron impact ionization of size selected hydrogen clusters (H2)N: ion fragment and neutral size distributions.

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Kornilov, Oleg; Toennies, J Peter

2008-05-21

Clusters consisting of normal H2 molecules, produced in a free jet expansion, are size selected by diffraction from a transmission nanograting prior to electron impact ionization. For each neutral cluster (H2)(N) (N=2-40), the relative intensities of the ion fragments Hn+ are measured with a mass spectrometer. H3+ is found to be the most abundant fragment up to N=17. With a further increase in N, the abundances of H3+, H5+, H7+, and H9+ first increase and, after passing through a maximum, approach each other. At N=40, they are about the same and more than a factor of 2 and 3 larger than for H11+ and H13+, respectively. For a given neutral cluster size, the intensities of the ion fragments follow a Poisson distribution. The fragmentation probabilities are used to determine the neutral cluster size distribution produced in the expansion at a source temperature of 30.1 K and a source pressure of 1.50 bar. The distribution shows no clear evidence of a magic number N=13 as predicted by theory and found in experiments with pure para-H2 clusters. The ion fragment distributions are also used to extract information on the internal energy distribution of the H3+ ions produced in the reaction H2+ + H2-->H3+ +H, which is initiated upon ionization of the cluster. The internal energy is assumed to be rapidly equilibrated and to determine the number of molecules subsequently evaporated. The internal energy distribution found in this way is in good agreement with data obtained in an earlier independent merged beam scattering experiment.

These Shoes Are Made for Walking: Sensitivity Performance Evaluation of Commercial Activity Monitors under the Expected Conditions and Circumstances Required to Achieve the International Daily Step Goal of 10,000 Steps.

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O'Connell, Sandra; ÓLaighin, Gearóid; Kelly, Lisa; Murphy, Elaine; Beirne, Sorcha; Burke, Niall; Kilgannon, Orlaith; Quinlan, Leo R

2016-01-01

Physical activity is a vitally important part of a healthy lifestyle, and is of major benefit to both physical and mental health. A daily step count of 10,000 steps is recommended globally to achieve an appropriate level of physical activity. Accurate quantification of physical activity during conditions reflecting those needed to achieve the recommended daily step count of 10,000 steps is essential. As such, we aimed to assess four commercial activity monitors for their sensitivity/accuracy in a prescribed walking route that reflects a range of surfaces that would typically be used to achieve the recommended daily step count, in two types of footwear expected to be used throughout the day when aiming to achieve the recommended daily step count, and in a timeframe required to do so. Four commercial activity monitors were worn simultaneously by participants (n = 15) during a prescribed walking route reflective of surfaces typically encountered while achieving the daily recommended 10,000 steps. Activity monitors tested were the Garmin Vivofit ™, New Lifestyles' NL-2000 ™ pedometer, Withings Smart Activity Monitor Tracker (Pulse O2) ™, and Fitbit One ™. All activity monitors tested were accurate in their step detection over the variety of different surfaces tested (natural lawn grass, gravel, ceramic tile, tarmacadam/asphalt, linoleum), when wearing both running shoes and hard-soled dress shoes. All activity monitors tested were accurate in their step detection sensitivity and are valid monitors for physical activity quantification over the variety of different surfaces tested, when wearing both running shoes and hard-soled dress shoes, and over a timeframe necessary for accumulating the recommended daily step count of 10,000 steps. However, it is important to consider the accuracy of activity monitors, particularly when physical activity in the form of stepping activities is prescribed as an intervention in the treatment or prevention of a disease state.

The influence of store image on customer satisfaction: a case study of a shoe store

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Tarsis Souza Silva

2010-01-01

Full Text Available Knowledge of customers' image of a store is an essential factor in the management of retail outlets. This article presents a case study of the effect of the image customers have of a shoe store on their satisfaction, based on a descriptive and quantitative survey, with the application of a structured questionnaire. We then employed factor analysis to obtain seven store image factors: assortment, convenience, reputation, price, atmosphere, layout and service. The results show that the factor that most affects customer satisfaction in the store studied is service, and that atmosphere and layout have no effect in this respect. The results provide a better understanding of the role store image plays in customer satisfaction and loyalty.

Modified distal shoe appliance for the loss of a primary second molar: a case report.

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Dhull, Kanika Singh; Bhojraj, Nandlal; Yadav, Shweta; Prabhakaran, Sheeja Devi

2011-01-01

Preservation of primary teeth until their normal exfoliation plays a crucial role in preventive and interceptive dentistry. Premature loss of the primary second molar prior to the eruption of the permanent first molar in the absence of the primary second molar can lead to mesial movement and migration of the permanent molar before and during its eruption. In such cases, an intra-alveolar type of space maintainer to guide the eruption of the permanent first molar is indicated. In certain cases, however, the conventional design is not practical. This paper describes a new design for distal shoe appliances in cases of primary second molar loss prior to the eruption of the permanent mandibular first molar.

Feature-size dependent selective edge enhancement of x-ray images

International Nuclear Information System (INIS)

Herman, S.

1988-01-01

Morphological filters are nonlinear signal transformations that operate on a picture directly in the space domain. Such filters are based on the theory of mathematical morphology previously formulated. The filt4er being presented here features a ''mask'' operator (called a ''structuring element'' in some of the literature) which is a function of the two spatial coordinates x and y. The two basic mathematical operations are called ''masked erosion'' and ''masked dilation''. In the case of masked erosion the mask is passed over the input image in a raster pattern. At each position of the mask, the pixel values under the mask are multiplied by the mask pixel values. Then the output pixel value, located at the center position of the mask,is set equal to the minimum of the product of the mask and input values. Similarity, for masked dilation, the output pixel value is the maximum of the product of the input and the mask pixel values. The two basic processes of dilation and erosion can be used to construct the next level of operations the ''positive sieve'' (also called ''opening'') and the ''negative sieve'' (''closing''). The positive sieve modifies the peaks in the image whereas the negative sieve works on image valleys. The positive sieve is implemented by passing the output of the masked erosion step through the masked dilation function. The negative sieve reverses this procedure, using a dilation followed by an erosion. Each such sifting operator is characterized by a ''hole size''. It will be shown that the choice of hole size will select the range of pixel detail sizes which are to be enhanced. The shape of the mask will govern the shape of the enhancement. Finally positive sifting is used to enhance positive-going (peak) features, whereas negative enhances the negative-going (valley) landmarks

Morpho morphometrics: Shared ancestry and selection drive the evolution of wing size and shape in Morpho butterflies.