1,102 research outputs found
Assessing infant carriage systems: ground reaction force implications for gait of the caregiver
Objective: To assess the acute alterations of anterior infant carriage systems on the ground reaction force experienced during over ground walking.
Background: Previous research has identified the alterations in posture and gait associated with an increased anterior load (external or internal); however the forces applied to the system due to the altered posture during over ground walking have not been established.
Method: Thirteen mixed gender participants completed forty-five over ground walking trials at a self-selected pace under three loaded conditions (unloaded, semi-structured carrier 9.9kg and structured carrier 9.9kg). Each trial consisted of a fifteen metre walkway, centred around a piezoelectric force platform sampling at 1200 Hz. Differences were assessed between loaded and unloaded conditions and across carriers using paired samples t-tests and repeated measures ANOVA.
Results: Additional load increased all ground reaction force parameters; however, the magnitude of force changes was influenced by carrier structure. The structured carrier displayed increased force magnitudes, a reduction in the time to vertical maximum heel contact and an increased duration of the flat foot phase in walking gait.
Conclusion: Evidence suggest that the acute application of anterior infant carriers alters both kinetic and temporal measures of walking gait. Importantly these changes appear to be governed not solely by the additional mass but also by the structure of the carrier.
Application: These findings indicate carrier structure should be considered by the wearer and may be used to inform policy in the recommendation of anterior infant carriage systems use by caregivers
Postural stability is affected in older males with Haemophilia—a matched control study
Despite fall-related injuries having serious consequences for older haemophilic patients, few studies have investigated their postural stability and risk of falls.
The aim was to examine postural stability, joint function and joint mobility in haemophiliacs and age-matched controls. Centre of pressure excursions in four 60 s balance conditions, two minute walk test, passive ankle and knee range of motion, Haemophilia Joint Health Score, and Haemophilia Early Arthropathy Detection with Ultrasound score were measured in eight men with haemophilia (people with heamophilia, PWH), and eight age-matched men without haemophilia (people without heamophilia, PWOH). PWH have significantly worse postural stability under physically perturbed conditions (p = 0.001–0.028, η2p
= 0.19–0.34), reduced joint function (p = 0.001–0.010, d = 1.33–2.62) and mobility (p < 0.001–0.025, d = 1.01–4.61), and increased centre of pressure (CoP) velocity (p < 0.001–0.003) when compared to PWOH. Postural stability among PWH did not deteriorate with time standing, although significant decreases compared to PWOH across all time intervals were observed (Eyes Open Foam (EOF) CoP ellipse (time x group) p = 0.011, η2p
= 0.28; path (time × group) p = 0.035, η2p
= 0.21; EOF CoP antero-posterior (AP) (time × group) p = 0.021, η2p
= 0.24). Joint function, mobility, and postural stability are reduced in PWH compared to PWOH, driven by differences in the CoP AP range. Dynamic tests incorporating physical perturbation may be more effective than static balance tests on a level surface, and longer period of time to assess postural stability may determine whether fatigue affects ability of PWH to maintain postural stability. Adoption of a possible ‘hip strategy’ by which to achieve balance suggests falls prevention programs need to focus on increasing hip strength and retraining ankle strategy movement to allow PWH to improve balance stability
The devil in the detail: Interpreting livelihood turbulence from a 25-year panel study from Thailand
10.1111/area.12188Area473296-30
"Hero Imagery" - Are there performance advantages associated with imagining yourself as your favourite athlete?
Objectives: This study examined whether there are performance advantages associated with a single bout of imagery when imagining yourself ‘as your favourite athlete’, or imagining yourself performing a strength-based task.
Design: A blind 2 (Imagery ability: high, low) x 3 (imagery condition: self, “hero”, control) mixed factorial design was used.
Methods: Participants (n = 17 male; Mage = 19.7 ± 2.7) completed the Sport Imagery Ability Questionnaire then viewed a standardised video demonstrating the grip strength (GS) task. Three baseline trials separated by one minute were then executed. Three imagery scripts (control, self, hero) were then presented to participants via an MP3 player in a counterbalanced order (an interval of 1-minute was provided between each condition). The conclusion of each imagery script prompted participants to perform the GS task. Performance in each condition was conceptualised as delta change scores (Imagery condition – baseline average).
Results: No main effects were present but there was a group x condition interaction (F(2,28) = 4.27, p = .02. ƞ_p^2= .23. The interaction suggests that for individuals with high imagery ability, simply “doing the imagery that they already do” is preferable compared to a scripted self- or hero-imagery condition. For individuals with a low imagery ability, a simple script whether that is self- or hero- based may enhance strength performance, compared to “what they already do”.
Conclusion: Imagery ability may influence the effectiveness of a brief imagery intervention. Further examination of processes and outcomes associated with “hero-imagery” is recommended
SSSPM J1444-2019: an extremely high proper motion, ultracool subdwarf
We present the discovery of a new extreme high proper motion object (3.5
arcsec/year) which we classify as an ultracool subdwarf with [M/H] = -0.5. It
has a formal spectral type of sdM9 but also shows L-type features: while the VO
bands are completely absent, it exhibits extremely strong TiO absorption in its
optical spectrum. With a radial velocity of about -160 km/s and a rough
distance estimate of 16--24 pc, it is likely one of the nearest halo members
crossing the Solar neighbourhood with a heliocentric space velocity of
(U,V,W)=(-244,-256,-100)+/-(32,77,6) km/s.Comment: 4 pages, 4 figures (Fig.1a-d available as jpg files), accepted for
publication in Astronomy & Astrophysics Letter
Lactation transcriptomics in the Australian marsupial, Macropus eugenii: transcript sequencing and quantification
<p>Abstract</p> <p>Background</p> <p>Lactation is an important aspect of mammalian biology and, amongst mammals, marsupials show one of the most complex lactation cycles. Marsupials, such as the tammar wallaby (<it>Macropus eugenii</it>) give birth to a relatively immature newborn and progressive changes in milk composition and milk production regulate early stage development of the young.</p> <p>Results</p> <p>In order to investigate gene expression in the marsupial mammary gland during lactation, a comprehensive set of cDNA libraries was derived from lactating tissues throughout the lactation cycle of the tammar wallaby. A total of 14,837 express sequence tags were produced by cDNA sequencing. Sequence analysis and sequence assembly were used to construct a comprehensive catalogue of mammary transcripts.</p> <p>Sequence data from pregnant and early or late lactating specific cDNA libraries and, data from early or late lactation massively parallel sequencing strategies were combined to analyse the variation of milk protein gene expression during the lactation cycle.</p> <p>Conclusion</p> <p>Results show a steady increase in expression of genes coding for secreted protein during the lactation cycle that is associated with high proportion of transcripts coding for milk proteins. In addition, genes involved in immune function, translation and energy or anabolic metabolism are expressed across the lactation cycle. A number of potential new milk proteins or mammary gland remodelling markers, including noncoding RNAs have been identified.</p
Camp Counseling and the Development and Transfer of Workforce Skills: The Perspective of Ohio 4-H Camp Counselor Alumni
Recent research shows that camp counselors, including those in 4-H, benefit from the experience by developing important life skills. However, because research regarding the perception of workforce skill development in this context has yielded inconsistent findings, the present study used focus groups to examine 4-H camp counselor alumni perceptions about the skills gained and transfer of these skills to other settings. Overall, 4-H camp counselor alumni thought their experience was fun and enjoyable, yet challenging. They believed they developed important life and workforce skills. Not only did alumni learn these skills, but the skills transferred beyond the camp setting. Leadership was noted as the skill most frequently applied to other contexts. Alumni believed that their counseling experiences had both indirect and direct impacts on their career choice. This study suggests many practical applications for those who work with camp programs
Diagnosis of vertebral fractures in children: is a simplified algorithm-based qualitative technique reliable?
Background Identification of osteoporotic vertebral fractures
allows treatment opportunity reducing future risk. There is no
agreed standardised method for diagnosing paediatric vertebral
fractures.
Objective To evaluate the precision of a modified adult
algorithm-based qualitative (ABQ) technique, applicable to
children with primary or secondary osteoporosis.
Materials and methods Three radiologists independently
assessed lateral spine radiographs of 50 children with
suspected reduction in bone mineral density using a modified
ABQ scoring system and following simplification to include
only clinically relevant parameters, a simplified ABQ score. A
final consensus of all observers using simplified ABQ was
performed as a reference standard for fracture characterisation.
Kappa was calculated for interobserver agreement of the
components of both scoring systems and intraobserver agreement
of simplified ABQ based on a second read of 29 randomly
selected images.
Results Interobserver Kappa for modified ABQ scoring for
fracture detection, severity and shape ranged from 0.34 to
0.49 Kappa for abnormal endplate and position assessment
was 0.27 to 0.38. Inter- and intraobserver Kappa for simplified
ABQ scoring for fracture detection and grade ranged from
0.37 to 0.46 and 0.45 to 0.56, respectively. Inter- and
intraobserver Kappa for affected endplate ranged from 0.31
to 0.41 and 0.45 to 0.51, respectively. Subjectively, observers’
felt simplified ABQ was easier and less time-consuming.
Conclusion Observer reliability of modified and simplified
ABQ was similar, with slight to moderate agreement for fracture
detection and grade/severity. Due to subjective preference
for simplified ABQ, we suggest its use as a semi-objective
measure of diagnosing paediatric vertebral fracture
Pressure dependence of the sound velocity in a 2D lattice of Hertz-Mindlin balls: a mean field description
We study the dependence on the external pressure of the velocities
of long wavelength sound waves in a confined 2D h.c.p. lattice of 3D
elastic frictional balls interacting via one-sided Hertz-Mindlin contact
forces, whose diameters exhibit mild dispersion. The presence of an underlying
long range order enables us to build an effective medium description which
incorporates the radial fluctuations of the contact forces acting on a single
site. Due to the non linearity of Hertz elasticity, self-consistency results in
a highly non-linear differential equation for the "equation of state" linking
the effective stiffness of the array with the applied pressure, from which
sound velocities are then obtained. The results are in excellent agreement with
existing experimental results and simulations in the high and intermediate
pressure regimes. It emerges from the analysis that the departure of
from the ideal Hertz behavior must be attributed primarily to the
fluctuations of the stress field, rather than to the pressure dependence of the
number of contacts
Social behaviour in zoo bachelor groups: a case study of related South American fur seals
Appropriate management of social groups is one of the greatest challenges that face zoos and aquaria worldwide. To facilitate breeding programmes, particularly in polygynous species, there is a need to house surplus males in bachelor groups, yet for pinnipeds, the social impact of this management strategy is unknown. The aim of this research was to enhance understanding of sociality in South American fur seals (SAFSs), with a particular focus on social dynamics in a related bachelor group, and consider implications for evidence-based management of this species in zoos. The subjects were four related male seals housed at Bristol Zoo Gardens. Social interaction and nearest neighbour data were collected between February and July 2019. Individuals engaged in both positive and negative social interactions. Positive interactions were more frequent than negative interactions, and no excessive negative interactions were observed. Temporal dynamics were observed in social relationships, and negative interactions did not increase with the onset of the breeding season. Reciprocity in dyadic relationships was variable across the study months, and nearest neighbours were not necessarily reflective of social partners. This research highlights the importance of longitudinal monitoring of social relationships and establishment of baseline social behaviour profiles to support evidence-based species management. We advocate that this research is extended, to further develop our understanding of SAFS social needs within zoo environments, to understand the differences between single-sex and mixed-sex groups and to identify the degree to which the extensive research conducted in other polygynous species (e.g., gorillas) is applicable in the social management of South American fur seals moving forwards
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