62 research outputs found
True-to-size surface mapping with neutral helium atoms
Three-dimensional mapping of microscopic surface structures is important in many applications
of technology and research, including areas as diverse as microfluidics, MEMS and geoscience. How-
ever on the nanoscale, using established techniques for such imaging can be extremely challenging.
Scanning helium microscopy (SHeM) is a new technique that uses neutral helium atoms as a probe,
enabling completely non-destructive imaging. The technique is broadly applicable and ideal for many
otherwise difficult to image materials such as insulators, ultra-thin nano-coatings and biological sam-
ples. Here we present a method for implementation and operation of a stereo helium microscope,
by applying the photometric stereo method of surface reconstruction to helium microscopy. Four
detectors around the sample are typically required, but we show how sample rotation can be used
to perform stereo reconstruction with a single detector instrument, or to improve the quality of
the reconstructed surface by increasing the number of independent measurements. We examine
the quality of the reconstructed surface and show that for low aspect ratio good absolute height is
recovered. For features with height/width ∼ 1 the shape of the surface is still recovered well (8%
error) despite multiple scattering and masking of the helium beam by surface topography. Therefore
it is possible to perform accurate reconstruction of the shape of nanoscale structures with a height
to width ratio of at least unity.SM Lambrick acknowledges funding from Mathworks Lt
Validity and reliability of lower-limb pulse-wave velocity assessments using an oscillometric technique
There is a growing interest in the deleterious effects of sedentary behaviour on lower-limb arterial health. To permit further investigation, including in larger epidemiological studies, there is a need to identify lower-limb arterial health assessment tools that are valid and reliable, yet simple to administer. Purpose: This study sought to determine the validity and between-day reliability of femoral-ankle pulse-wave velocity (faPWV) measures obtained using an oscillometric-based device (SphygmocCor XCEL) in supine and seated positions. Doppler ultrasound (US) was used as the criterion. Methods: A total of 47 healthy adults were recruited for validity (n=32) and reliability (n=15) analyses. Validity was determined by measuring faPWV in seated and supine positions using the XCEL and US devices, in a randomised order. Between-day reliability was determined by measuring seated and supine faPWV using the XCEL on 3 different mornings, separated by a maximum of 7 days. Results: The validity criteria (absolute standard error of estimate [aSEE] <1.0 m/s) was met in the supine (aSEE = 0.8 m/s, 95% CI: 0.4-1.0), but not the seated (aSEE = 1.2 m/s, 95 % CI: 1.1, 1.2) position. Intras-class correlation coefficient estimates revealed the XCEL demonstrated good reliability in the supine position (ICC=0.83, 95% CI: 0.65, 0.93), but poor reliability in the seated position (ICC = 0.29, 95% CI: 0.23, 0.63). Conclusions: The oscillometric XCEL device can be used to determine lower-limb PWV with acceptable validity and reliability in the conventionally recommended supine position, but not the seated position
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'The debatable territory where geology and archaeology meet': reassessing the early archaeobotanical work of Clement Reid and Arthur Lyell at Roman Silchester
The first large-scale archaeobotanical study in Britain, conducted from 1899 to 1909 by Clement Reid and
Arthur Lyell at Silchester, provided the first evidence for the introduction of Roman plant foods to Britain,
yet the findings have thus far remained unverified. This paper presents a reassessment of these
archaeobotanical remains, now stored as part of the Silchester Collection in Reading Museum. The
documentary evidence for the Silchester study is summarised, before the results are presented for over a
1000 plant remains including an assessment of preservation, identification and modern contamination.
The dataset includes both evidence for the presence of nationally rare plant foods, such as medlar, and
several archaeophytes. The methodologies and original interpretations of Reid and Lyell’s study are
reassessed in light of current archaeobotanical knowledge. Spatial and contextual patterns in the
distribution of plant foods and ornamental taxa are also explored. Finally, the legacy of the study for the
development of archaeobotany in the 20th century is evaluated
High-Intensity Interval Training Interventions in Children and Adolescents: A Systematic Review
BackgroundWhilst there is increasing interest in the efficacy of high-intensity interval training in children and adolescents as a time-effective method of eliciting health benefits, there remains little consensus within the literature regarding the most effective means for delivering a high-intensity interval training intervention. Given the global health issues surrounding childhood obesity and associated health implications, the identification of effective intervention strategies is imperative.ObjectivesThe aim of this review was to examine high-intensity interval training as a means of influencing key health parameters and to elucidate the most effective high-intensity interval training protocol.MethodsStudies were included if they: (1) studied healthy children and/or adolescents (aged 5–18 years); (2) prescribed an intervention that was deemed high intensity; and (3) reported health-related outcome measures.ResultsA total of 2092 studies were initially retrieved from four databases. Studies that were deemed to meet the criteria were downloaded in their entirety and independently assessed for relevance by two authors using the pre-determined criteria. From this, 13 studies were deemed suitable. This review found that high-intensity interval training in children and adolescents is a time-effective method of improving cardiovascular disease biomarkers, but evidence regarding other health-related measures is more equivocal. Running-based sessions, at an intensity of >90% heart rate maximum/100–130% maximal aerobic velocity, two to three times a week and with a minimum intervention duration of 7 weeks, elicit the greatest improvements in participant health.ConclusionWhile high-intensity interval training improves cardiovascular disease biomarkers, and the evidence supports the effectiveness of running-based sessions, as outlined above, further recommendations as to optimal exercise duration and rest intervals remain ambiguous owing to the paucity of literature and the methodological limitations of studies presently available
A Training Course for Psychologists: Learning to Assess (Alleged) Sexual Abuse Among Victims and Perpetrators Who Have Intellectual Disabilities
People with intellectual disabilities (ID) are at greater risk of being a victim of sexual abuse and may also be more predisposed to perpetrating sexual abuse. Although the prevalence of sexual abuse among people with ID is difficult to determine, it is clear that there are serious consequences for both victims and perpetrators, and professional support is needed. Psychologists play an important role in the assessment of sexual abuse in both victims and perpetrators and require specific knowledge and skills to execute the assessments. We therefore developed a training course for psychologists aimed at increasing their (applied) knowledge of sexual abuse and the related assessment process in people with ID. In a five-day training course, sessions focusing on theories about diagnostic models were combined with sessions focusing on the assessment of sexual abuse of victims and perpetrators. The effectiveness of the training course was determined in terms of (applied) knowledge via the administration of a study-specific questionnaire including a hypothetical case vignette before, immediately after, and six months after completion of the course. The results show that the knowledge of the psychologists related to sexual abuse and the assessment process for sexual abuse increased significantly, and remained above pre-test level at six-month follow-up. These results are promising, but more research is needed to see if the increased (applied) knowledge in turn leads to application in practice and better care for both victims and perpetrators
Effects of an exercise program on hepatic metabolism, hepatic fat, and cardiovascular health in overweight/obese adolescents from Bogotá, Colombia (the HEPAFIT study): study protocol for a randomized controlled trial
Background: A considerable proportion of contemporary youth have a high risk of obesity-related disorders such
as cardiovascular disease, metabolic syndrome, or non-alcoholic fatty liver disease (NAFLD). Although there is consistent
evidence for the positive effects of physical activity on several health aspects, most adolescents in Colombia are
sedentary. It is, therefore, important to implement strategies that generate changes in lifestyle. The HEPAFIT study
aims to examine whether a 6-month exercise program has benefits for hepatic fat content and cardiovascular health
outcomes among overweight/obese adolescents from Bogotá, Colombia.
Methods/design: Altogether, 100 hundred overweight/obese, sedentary adolescents (aged 11–17 years) attending two
public schools in Bogotá, Colombia, will be included in a parallel-group randomized controlled trial. Adolescents will be
randomly assigned to an intervention group following one of four curricula: (1) the standard physical education
curriculum (60 min per week of physical activity, n = 25) at low-to-moderate intensity; (2) a high-intensity physical
education curriculum (HIPE, n = 25), consisting of endurance and resistance games and non-competitive activities,
such as running, gymkhanas, lifting, pushing, wrestling, or hauling, for 60-min sessions, three times per week, with
an energy expenditure goal of 300 to 500 kcal/session at 75–85% maximum heart rate (HRmax); (3) a low-to-moderate
intensity physical education curriculum (LIPE, n = 25) consisting of endurance and resistance games and non-competitive
activities (e.g., chasing, sprinting, dribbling, or hopping) for 60-min sessions, three times per week with an energy
expenditure goal of 300 kcal/session at 55–75% HRmax; and (4) a combined HIPE and LIPE curriculum (n = 25).
The HIPE, LIPE, and combined interventions were performed in addition to the standard physical education curriculum.
The primary outcome for effectiveness is liver fat content, as measured by the controlled attenuation parameter 1
week after the end of the intervention program.
Discussion: The translational focus may be suitable for collecting new information in a school setting on the
possible effects of physical activity interventions to reduce liver fat content and to improve metabolic profiles
and the cardiometabolic health of overweight/obese adolescents. This may lead to the more efficient use of
school physical education resources.The HEPAFIT study was carried out with the financial support of Instituto
Colombiano para el Desarrollo de la Ciencia y la Tecnología “Francisco José
de Caldas” COLCIENCIAS (code 59700 and no 122277757900). Katherine
González-Ruíz receive a scholarship from Universidad del Rosario, Colombia,
Escuela de Medicina y Ciencias de la Salud, to do a Doctorate. This article
presents independent research commissioned by COLCIENCIAS under its
Program Grants for Applied Research funding scheme (Convocatoria 777–2017)
Changing the prehistory of Sindh and Las Bela coast: twenty-five years of Italian contribution
The paper discusses the prehistory of Lowr Sindh and Las Bela Coast, and the role played by the Italian archaeologists since the 1980's. New date are presented regarding mainly the radiocarbon chronology the Indus Delta settlement on rocky outcrops and the shell middens of Las Bela
Review of archaeological assessment and monitoring procedures in Ireland
SIGLEAvailable from British Library Document Supply Centre-DSC:m00/43193 / BLDSC - British Library Document Supply CentreGBUnited Kingdo
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