58 research outputs found
Characterisation and tracking of membrane surfaces at NASA Langley Research Centre
Aerospace engineers require measurements of the shape of aerodynamic surfaces and the six degree of freedom (6DoF) position and
orientation of aerospace models to analyse structural dynamics and aerodynamic forces. The measurement technique must be noncontact,
accurate, reliable, have a high sample rate and preferably be non-intrusive. Close range photogrammetry based on multiple,
synchronised, commercial-off-the-shelf digital cameras can supply surface shape and 6DoF data at 5-15Hz with customisable
accuracies. This paper describes data acquisition systems designed and implemented at NASA Langley Research Center to capture
surface shapes and 6DoF data. System calibration and data processing techniques are discussed. Examples of experiments and data
outputs are described
Assessing cognitive dysfunction in Parkinson’s: An online tool to detect visuo-perceptual deficits
BACKGROUND: People with Parkinson’s disease
(PD) who develop visuo-perceptual deficits are at higher
risk of dementia, but we lack tests that detect subtle visuoperceptual
deficits and can be performed by untrained personnel.
Hallucinations are associated with cognitive impairment
and typically involve perception of complex objects.
Changes in object perception may therefore be a sensitive
marker of visuo-perceptual deficits in PD.
Objective: We developed an online platform to test
visuo-perceptual function. We hypothesised that (1)
visuo-perceptual deficits in PD could be detected using
online tests, (2) object perception would be preferentially
affected, and (3) these deficits would be caused
by changes in perception rather than response bias.
METHODS: We assessed 91 people with PD and 275 controls.
Performance was compared using classical frequentist
statistics. We then fitted a hierarchical Bayesian signal
detection theory model to a subset of tasks.
RESULTS: People with PD were worse than controls at
object recognition, showing no deficits in other visuoperceptual
tests. Specifically, they were worse at identifying
skewed images (P <.0001); at detecting hidden
objects (P 5.0039); at identifying objects in peripheral
vision (P <.0001); and at detecting biological motion
(P 5.0065). In contrast, people with PD were not worse
at mental rotation or subjective size perception. Using
signal detection modelling, we found this effect was
driven by change in perceptual sensitivity rather than
response bias.
CONCLUSIONS: Online tests can detect visuo-perceptual defi-
cits in people with PD, with object recognition particularly
affected. Ultimately, visuo-perceptual tests may be developed
to identify at-risk patients for clinical trials to slow PD dementia
Defensive coping and health-related quality of life in chronic kidney disease: a cross-sectional study
<p>Abstract</p> <p>Background</p> <p>Coping with the stresses of chronic disease is considered as a key factor in the perceived impairment of health related quality of life (HRQL). Little is known though about these associations in chronic kidney disease (CKD). The present study aimed to investigate the relationship of defensive coping and HRQL among patients in different CKD stages, after adjusting for psychological distress, sociodemographic and disease-related variables.</p> <p>Methods</p> <p>The sample consisted of 98 CKD patients, attending a university nephrology department. Seventy-nine (79) pre-dialysis patients of disease stages 3 to 4 and 19 dialysis patients were included. HRQL was assessed by the 36-item Short-Form health survey (SF-36), defensive coping by the Rationality/Emotional Defensiveness (R/ED) scale of the Lifestyle Defense Mechanism Inventory (LDMI) and psychological distress by the depression and anxiety scales of the revised Hopkins Symptom CheckList (SCL-90-R). Regression analyses were carried out to examine the association between SF-36 dimensions and defensive coping style.</p> <p>Results</p> <p>Patients on dialysis had worse scores on SF-36 scales measuring physical aspects of HRQL. In the fully adjusted analysis, a higher defensive coping score was significantly associated with a lower score on the mental component summary (MCS) scale of the SF-36 (worse mental health). In contrast, a higher defensive score showed a small positive association with the physical component summary (PCS) scale of the SF-36 (better health), but this was marginally significant.</p> <p>Conclusions</p> <p>The results provided evidence that emotional defensiveness as a coping style tends to differentially affect the mental and the physical component of HRQL in CKD. Clinicians should be aware of the effects of long-term denial and could examine the possibility of screening for defensive coping and depression in recently diagnosed CKD patients with the aim to improve both physical and mental health.</p
Variable effects of maternal and paternal–fetal contribution to the risk for preeclampsia combining GSTP1, eNOS, and LPL gene polymorphisms
Long-Stay Psychiatric Patients: A Prospective Study Revealing Persistent Antipsychotic-Induced Movement Disorder
OBJECTIVE: The purpose of this study was to assess the frequency of persistent drug-induced movement disorders namely, tardive dyskinesia (TD), parkinsonism, akathisia and tardive dystonia in a representative sample of long-stay patients with chronic severe mental illness. METHOD: Naturalistic study of 209, mainly white, antipsychotic-treated patients, mostly diagnosed with psychotic disorder. Of this group, the same rater examined 194 patients at least two times over a 4-year period, with a mean follow-up time of 1.1 years, with validated scales for TD, parkinsonism, akathisia, and tardive dystonia. RESULTS: The frequencies of persistent movement disorders in the sample were 28.4% for TD, 56.2% for parkinsonism, 4.6% for akathisia and 5.7% for tardive dystonia. Two-thirds of the participants displayed at least one type of persistent movement disorder. CONCLUSIONS: Persistent movement disorder continues to be the norm for long-stay patients with chronic mental illness and long-term antipsychotic treatment. Measures are required to remedy this situation
Factor structure of the Positive and Negative Syndrome Scale (PANSS) in Brazil: convergent validation of the Brazilian version
Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases
The production of peroxide and superoxide is an inevitable consequence of
aerobic metabolism, and while these particular "reactive oxygen species" (ROSs)
can exhibit a number of biological effects, they are not of themselves
excessively reactive and thus they are not especially damaging at physiological
concentrations. However, their reactions with poorly liganded iron species can
lead to the catalytic production of the very reactive and dangerous hydroxyl
radical, which is exceptionally damaging, and a major cause of chronic
inflammation. We review the considerable and wide-ranging evidence for the
involvement of this combination of (su)peroxide and poorly liganded iron in a
large number of physiological and indeed pathological processes and
inflammatory disorders, especially those involving the progressive degradation
of cellular and organismal performance. These diseases share a great many
similarities and thus might be considered to have a common cause (i.e.
iron-catalysed free radical and especially hydroxyl radical generation). The
studies reviewed include those focused on a series of cardiovascular, metabolic
and neurological diseases, where iron can be found at the sites of plaques and
lesions, as well as studies showing the significance of iron to aging and
longevity. The effective chelation of iron by natural or synthetic ligands is
thus of major physiological (and potentially therapeutic) importance. As
systems properties, we need to recognise that physiological observables have
multiple molecular causes, and studying them in isolation leads to inconsistent
patterns of apparent causality when it is the simultaneous combination of
multiple factors that is responsible. This explains, for instance, the
decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference
Differential profiling of lacrimal cytokines in patients suffering from thyroid-associated orbitopathy.
The aim was to investigate the levels of cytokines and soluble IL-6R in the tears of patients with thyroid-associated orbitopathy (TAO) disease. Schirmer's test was adopted to collect tears from TAO patients (N = 20, 17 women, mean age (±SD): 46.0 years (±13.4)) and healthy subjects (N = 18, 10 women, 45.4 years (±18.7)). Lacrimal cytokines and soluble IL-6R (sIL-6R) were measured using a 10-plex panel (Meso Scale Discovery Company) and Invitrogen Human sIL-6R Elisa kit, respectively. Tear levels of IL-10, IL-12p70, IL-13, IL-6 and TNF-α appeared significantly higher in TAO patients than in healthy subjects. Interestingly, IL-10, IL-12p70 and IL-8 levels increased in tears whatever the form of TAO whereas IL-13, IL-6 and TNF-α levels were significantly elevated in inflammatory TAO patients, meaning with a clinical score activity (CAS) ≥ 3, compared to controls. Furthermore, only 3 cytokines were strongly positively correlated with CAS (IL-13 Spearman coeff. r: 0.703, p = 0.0005; IL-6 r: 0.553, p = 0.011; IL-8 r: 0.618, p = 0.004, respectively). Finally, tobacco use disturbed the levels of several cytokines, especially in patient suffering of TAO. The differential profile of lacrimal cytokines could be useful for the diagnosis of TAO patients. Nevertheless, the tobacco use of these patients should be taken into account in the interpretation of the cytokine levels
The Cats-and-Dogs test: A tool to identify visuoperceptual deficits in Parkinson's disease
No abstract available
Semi-Automated Operational Modal Analysis Methodology to Optimize Modal Parameter Estimation
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