10,392 research outputs found
The Complexity of Human Walking: A Knee Osteoarthritis Study
This study proposes a framework for deconstructing complex walking patterns to create a simple principal component space before checking whether the projection to this space is suitable for identifying changes from the normality. We focus on knee osteoarthritis, the most common knee joint disease and the second leading cause of disability. Knee osteoarthritis affects over 250 million people worldwide. The motivation for projecting the highly dimensional movements to a lower dimensional and simpler space is our belief that motor behaviour can be understood by identifying a simplicity via projection to a low principal component space, which may reflect upon the underlying mechanism. To study this, we recruited 180 subjects, 47 of which reported that they had knee osteoarthritis. They were asked to walk several times along a walkway equipped with two force plates that capture their ground reaction forces along 3 axes, namely vertical, anterior-posterior, and medio-lateral, at 1000 Hz. Data when the subject does not clearly strike the force plate were excluded, leaving 1–3 gait cycles per subject. To examine the complexity of human walking, we applied dimensionality reduction via Probabilistic Principal Component Analysis. The first principal component explains 34% of the variance in the data, whereas over 80% of the variance is explained by 8 principal components or more. This proves the complexity of the underlying structure of the ground reaction forces. To examine if our musculoskeletal system generates movements that are distinguishable between normal and pathological subjects in a low dimensional principal component space, we applied a Bayes classifier. For the tested cross-validated, subject-independent experimental protocol, the classification accuracy equals 82.62%. Also, a novel complexity measure is proposed, which can be used as an objective index to facilitate clinical decision making. This measure proves that knee osteoarthritis subjects exhibit more variability in the two-dimensional principal component space
On the hydrogen neutral outflowing disks of B[e] supergiants
(abridged) B[e] supergiants are known to possess geometrically thick dusty
disks. Disk-forming wind models have, however, been found to be insufficient in
reproducing the observed dust emission. This problem arises due to the severe
assumption that, as for classical Be stars, the near-infrared excess emission
originates in the disk. Modeling of the free-free and free-bound emission
therefore results in an upper limit for the disk mass loss rate, hampering dust
condensation in the disk. We propose a revised scenario for the non-spherical
winds of B[e] supergiants: a normal B-type line-driven polar wind and an
outflowing disk-forming wind that is neutral in hydrogen at, or very close to
the stellar surface. We concentrate on the pole-on seen LMC B[e] supergiant
R126 and calculate the line luminosities of the optical [OI] emission lines
with an outflowing disk scenario. In addition, we compute the free-free and
free-bound emission from a line-driven polar wind and model the spectral energy
distribution in the optical and near-infrared. Good fits to the [OI] line
luminosities are achieved for an outflowing disk that is neutral in hydrogen
right from the stellar surface. Neutral thereby means that hydrogen is ionized
by less than 0.1%. Consequently, the free-free and free-bound emission cannot
(dominantly) arise from the disk and cannot limit the disk mass loss rate. The
hydrogen neutral outflowing disk scenario therefore provides an ideal
environment for efficient dust formation. The spectral energy distribution in
the optical and near-infrared range can be well fitted with the stellar
continuum plus free-free and free-bound emission from the polar line-driven
wind. Our modeling further delivers minimum values for \dot{M}(disk) > 2.5d-5
M_sun/yr and for the density contrast between equatorial and polar wind of ~10.Comment: 9 pages, 8 figures, accepted for publication in A&
Actual past discrimination or group membership as a requirement to benefit from affirmative action: A comparison between South African and American case law
This note analyses the South African and US positions with regard to the issue of whether actual past discrimination is required as a prerequisite to benefit from affirmative action or whether membership of a designated group will suffice. The focus is on employment law. Categorisation of affirmative action beneficiaries and criticism of the same are covered. The consequences of over- and under-inclusiveness will briefly be addressed. This is done against the background of the various notions of equality. It seems that the US courts (following the notion of equality of opportunity) had initially been unwilling to accord Blacks and women the benefit of a conclusive presumption of victimization, notwithstanding wide acceptance of the fact that discrimination had adversely affected them. A showing of actual past discrimination was required until the late 1980s when case law made it clear that this was not necessary any longer. At present, however, the pendulum has moved back again and a strong evidentiary basis must be made out that discrimination had in fact taken place and that it had an impact on the group as a whole. In SA where affirmative action has been implemented only since 1999 (in contrast to the 40 years of experience of the US), the courts quickly made it clear that membership of a designated group and not actual disadvantage is what is required. This interpretation is in line with the notion of substantive equality, as embraced by the Constitution and the EEA. Hopefully, this approach will successfully address SA’s history of systemic and pervasive discrimination. Although the use of categories of beneficiaries will no doubt also lead to over-inclusion, it should be kept in mind that the situation in SA is different to that of the US, in that a majority must be affirmed
Pacific Island food security: situation, challenges and opportunities
In recent years, there have been large and rapid increases in the prices of basic foods worldwide. Pacific island countries have not been isolated from the global food 'crisis'. This article shows that there are substantial differences in the impacts within and between Pacific island countries. To be effective and not counterproductive, policy and donor responses need to be tailored accordingly. This article recommends a combination of measures directed at mitigating the threats and empowering rural people to take advantage of the opportunities
Diurnal fluctuation in the number of hypocretin/orexin and histamine producing: Implication for understanding and treating neuronal loss.
The loss of specific neuronal phenotypes, as determined by immunohistochemistry, has become a powerful tool for identifying the nature and cause of neurological diseases. Here we show that the number of neurons identified and quantified using this method misses a substantial percentage of extant neurons in a phenotype specific manner. In mice, 24% more hypocretin/orexin (Hcrt) neurons are seen in the night compared to the day, and an additional 17% are seen after inhibiting microtubule polymerization with colchicine. We see no such difference between the number of MCH (melanin concentrating hormone) neurons in dark, light or colchicine conditions, despite MCH and Hcrt both being hypothalamic peptide transmitters. Although the size of Hcrt neurons did not differ between light and dark, the size of MCH neurons was increased by 15% in the light phase. The number of neurons containing histidine decarboxylase (HDC), the histamine synthesizing enzyme, was 34% greater in the dark than in the light, but, like Hcrt, cell size did not differ. We did not find a significant difference in the number or the size of neurons expressing choline acetyltransferase (ChAT), the acetylcholine synthesizing enzyme, in the horizontal diagonal band (HBD) during the dark and light conditions. As expected, colchicine treatment did not increase the number of these neurons. Understanding the function and dynamics of transmitter production within "non-visible" phenotypically defined cells has fundamental implications for our understanding of brain plasticity
Alien Registration- Mcgregor, John M. (Gouldsboro, Hancock County)
https://digitalmaine.com/alien_docs/19769/thumbnail.jp
The Richard commission and the financing of devolved government : the economics of devolution in Wales: Briefing No. 8
If the Barnett formula is rigorously applied to determine the budget of the Welsh Assembly Government, this will ultimately adversely affect the economy of Wales by limiting the growth in aggregate demand. This effect is reinforced now that population weights determining rises in expenditure in Wales (and Scotland and Northern Ireland) are regularly up-dated. There is some controversy in Wales about whether some form of needs-assessment exercise would favour Wales relative to its current position. What is clear is that the outcome of a rigorous, long term application of the Barnett formula would be a share of UK public expenditures in Wales (and Scotland and Northern Ireland) that was almost certainly below the level that would be dictated by any conventional understanding of 'needs'. The impact of the tax-varying power favoured by the Richard Commission is ambiguous, with the direction of effects dependent on the reaction of the current labour force and potential migrants. If workers insist on full compensation for loss of income to tax through a rise in gross wages a tax rise would lead to an economic contraction. However, if workers value the additional public services financed by the tax rise as equal to their loss of disposable income, this effect can be avoided. Much in other words would depend on how the proceeds of the tax rise were spen
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