1,179 research outputs found
Calibration and cross-validation of the ActiGraph wGT3X+ accelerometer for the estimation of physical activity intensity in children with intellectual disabilities
Background:
Valid objective measurement is integral to increasing our understanding of physical activity and sedentary behaviours. However, no population-specific cut points have been calibrated for children with intellectual disabilities. Therefore, this study aimed to calibrate and cross-validate the first population-specific accelerometer intensity cut points for children with intellectual disabilities.
Methods:
Fifty children with intellectual disabilities were randomly assigned to the calibration (n = 36; boys = 28, 9.53±1.08yrs) or cross-validation (n = 14; boys = 9, 9.57±1.16yrs) group. Participants completed a semi-structured school-based activity session, which included various activities ranging from sedentary to vigorous intensity. Direct observation (SOFIT tool) was used to calibrate the ActiGraph wGT3X+, which participants wore on the right hip. Receiver Operating Characteristic curve analyses determined the optimal cut points for sedentary, moderate, and vigorous intensity activity for the vertical axis and vector magnitude. Classification agreement was investigated using sensitivity, specificity, total agreement, and Cohenâs kappa scores against the criterion measure of SOFIT.
Results:
The optimal (AUC = .87â.94) vertical axis cut points (cpm) were â€507 (sedentary), 1008â2300 (moderate), and â„2301 (vigorous), which demonstrated high sensitivity (81â88%) and specificity (81â85%). The optimal (AUC = .86â.92) vector magnitude cut points (cpm) of â€1863 (sedentary), 2610â4214 (moderate), and â„4215 (vigorous) demonstrated comparable, albeit marginally lower, accuracy than the vertical axis cut points (sensitivity = 80â86%; specificity = 77â82%). Classification agreement ranged from moderate to almost perfect (Îș = .51â.85) with high sensitivity and specificity, and confirmed the trend that accuracy increased with intensity, and vertical axis cut points provide higher classification agreement than vector magnitude cut points.
Conclusions:
This study provides the first valid methods of interpreting accelerometer output in children with intellectual disabilities. The calibrated physical activity cut points are notably higher than existing cut points, thus raising questions on the validity of previous low physical activity estimates in children with intellectual disabilities that were based on typically developing cut point
Toxic & Hegemonic Masculinity, Gender Stereotypes & Resonance: The Problematic Snickersâ âGet Some Nutsâ Ad
This paper discusses the ethical implications of the Snickersâ ad campaign, âGet Some Nutsâ. Through priming, framing, race, gender and sexuality stereotypes, researchers explore cultural resonance and hegemonic ideologies within this ad. In this study, close to 200 students examined separate international ethical standards toward this 30-second commercial starring Mr. T. Student comments collected indicated that implicit racist, sexist and homophobic lenses resonated and caused ethical concerns
Advancing the Rights of Children and Adolescents to Be Altruistic: Bone Marrow Donation by Minors
This article examines the standards used for answering the question of whether minors should be allowed to donate bone marrow. Part II introduces the legal background and the standards currently used by courts. Part III explores the unsatisfactory nature of these standards. Part IV presents an empirical study that is intended to provide some help in understanding what might be a useful and respectful standard. Part V concludes the article with a discussion of two alternative revised standards grounded in the doctrines of substituted judgment and the best interests of the child
On minimal ideals in pseudo-finite semigroups
This work was supported by the Engineering and Physical Sciences Research Council [EP/V002953/1].A semigroup S is said to be right pseudo-finite if the universal right congruence can be generated by a finite set UâSĂS, and there is a bound on the length of derivations for an arbitrary pair (s,t)âSĂS as a consequence of those in U. This article explores the existence and nature of a minimal ideal in a right pseudo-finite semigroup. Continuing the theme started in an earlier work by Dandan et al., we show that in several natural classes of monoids, right pseudo-finiteness implies the existence of a completely simple minimal ideal. This is the case for orthodox monoids, completely regular monoids and right reversible monoids, which include all commutative monoids. We also show that certain other conditions imply the existence of a minimal ideal, which need not be completely simple; notably, this is the case for semigroups in which one of the Green's pre-orders â€L or â€J is left compatible with multiplication. Finally, we establish a number of examples of pseudo-finite monoids without a minimal ideal. We develop an explicit construction that yields such examples with additional desired properties, for instance, regularity or J-triviality.PostprintPeer reviewe
On minimal ideals in pseudo-finite semigroups
A semigroup is said to be right pseudo-finite if the universal right
congruence can be generated by a finite set , and there
is a bound on the length of derivations for an arbitrary pair as a consequence of those in . This article explores the existence and
nature of a minimal ideal in a right pseudo-finite semigroup. Continuing the
theme started in an earlier work by Dandan et al., we show that in several
natural classes of monoids, right pseudo-finiteness implies the existence of a
completely simple minimal ideal. This is the case for orthodox monoids,
completely regular monoids and right reversible monoids, which include all
commutative monoids. We also show that certain other conditions imply the
existence of a minimal ideal, which need not be completely simple; notably,
this is the case for semigroups in which one of the Green's pre-orders
or is left compatible with
multiplication. Finally, we establish a number of examples of pseudo-finite
monoids without a minimal ideal. We develop an explicit construction that
yields such examples with additional desired properties, for instance,
regularity or -triviality
Testing the Role of Genetic Background in Parallel Evolution Using the Comparative Experimental Evolution of Antibiotic Resistance
The research leading to these results has received funding from the European Research Council under the European Unionâs Seventh Framework Programme (FP7/2007â2013)/ERC grant agreement no. 281591 and from the Royal Society. V.F. was supported by an MEC Postdoctoral Fellowship from the Spanish Government (EX-2010-0958). T.V. and M.K. carried out the experimental work and analyzed experimental data with R.C.M.; V.F. constructed the phylogeny; V.F. and T.V. carried out comparative analyses; T.V. and R.C.M. prepared the manuscript and all authors contributed to designing the study.Peer reviewedPublisher PD
The Pulsed Spectra of Two Extraordinary Pulsars
We report on X-ray monitoring of two isolated pulsars within the same RXTE
field of view. PSR J1811-1925 in the young supernova remnant G11.2-0.3 has a
nearly sinusoidal pulse profile with a hard pulsed spectrum (photon index
\~1.2). The pulsar is a highly efficient (~ 1% of spin-down energy) emitter of
2-50 keV pulsed X-rays despite having a fairly typical B ~ 2e12 G magnetic
field. PSR J1809-1943/XTE J1810-197 is a newly discovered slow (P=5.54 s),
apparently isolated X-ray pulsar which increased in flux by a factor of ~100 in
2003 January. Nine months of monitoring observations have shown a decrease in
pulsed flux of ~ 30% without a significant change in its apparently thermal
spectrum (kT ~0.7 keV) or pulse profile. During this time, the spin-down torque
has fluctuated by a factor of ~ 2. Both the torque and the flux have remained
steady for the last 3 months, at levels consistent with a magnetar
interpretation.Comment: 3 pages, 4 figures, to appear in the Proceedings of X-ray Timing
2003: Rossi and Beyond, ed. P. Kaaret, F.K. Lamb, & J.H. Swank held in
Cambridge, MA, Nov. 3-5, 200
Genetic Drift Dominates Genome-Wide Regulatory Evolution Following an Ancient Whole-Genome Duplication in Atlantic Salmon
Whole-genome duplications (WGD) have been considered as springboards that potentiate lineage diversification through increasing functional redundancy. Divergence in gene regulatory elements is a central mechanism for evolutionary diversification, yet the patterns and processes governing regulatory divergence following events that lead to massive functional redundancy, such as WGD, remain largely unknown. We studied the patterns of divergence and strength of natural selection on regulatory elements in the Atlantic salmon (Salmo salar) genome, which has undergone WGD 100â80âMa. Using ChIPmentation, we first show that H3K27ac, a histone modification typical to enhancers and promoters, is associated with genic regions, tissue-specific transcription factor binding motifs, and with gene transcription levels in immature testes. Divergence in transcription between duplicated genes from WGD (ohnologs) correlated with difference in the number of proximal regulatory elements, but not with promoter elements, suggesting that functional divergence between ohnologs after WGD is mainly driven by enhancers. By comparing H3K27ac regions between duplicated genome blocks, we further show that a longer polyploid state post-WGD has constrained regulatory divergence. Patterns of genetic diversity across natural populations inferred from resequencing indicate that recent evolutionary pressures on H3K27ac regions are dominated by largely neutral evolution. In sum, our results suggest that post-WGD functional redundancy in regulatory elements continues to have an impact on the evolution of the salmon genome, promoting largely neutral evolution of regulatory elements despite their association with transcription levels. These results highlight a case where genome-wide regulatory evolution following an ancient WGD is dominated by genetic drift.Peer reviewe
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