367 research outputs found
A Systematic Review of Extended Reality (XR) for Understanding and Augmenting Vision Loss
Over the past decade, extended reality (XR) has emerged as an assistive
technology not only to augment residual vision of people losing their sight but
also to study the rudimentary vision restored to blind people by a visual
neuroprosthesis. To make the best use of these emerging technologies, it is
valuable and timely to understand the state of this research and identify any
shortcomings that are present. Here we present a systematic literature review
of 227 publications from 106 different venues assessing the potential of XR
technology to further visual accessibility. In contrast to other reviews, we
sample studies from multiple scientific disciplines, focus on augmentation of a
person's residual vision, and require studies to feature a quantitative
evaluation with appropriate end users. We summarize prominent findings from
different XR research areas, show how the landscape has changed over the last
decade, and identify scientific gaps in the literature. Specifically, we
highlight the need for real-world validation, the broadening of end-user
participation, and a more nuanced understanding of the suitability and
usability of different XR-based accessibility aids. By broadening end-user
participation to early stages of the design process and shifting the focus from
behavioral performance to qualitative assessments of usability, future research
has the potential to develop XR technologies that may not only allow for
studying vision loss, but also enable novel visual accessibility aids with the
potential to impact the lives of millions of people living with vision loss
Evidence for Magnetic Field Induced Changes of the Phase of Tunneling States: Spontaneous Echoes in (KBr)(KCN) in Magnetic Fields
Recently, it has been discovered that in contrast to expectations the
low-temperature dielectric properties of some multi-component glasses depend
strongly on magnetic fields. In particular, the low-frequency dielectric
susceptibility and the amplitude of coherent polarization echoes show striking
non-monotonic magnetic field dependencies. The low-temperature dielectric
response of these materials is governed by atomic tunneling systems. We now
have investigated the coherent properties of tunneling states in a crystalline
host in magnetic fields up to 230mT. Two-pulse echo experiments have been
performed on a KBr crystal containing about 7.5% CN. Like in glasses, but
perhaps even more surprising in the case of a crystalline system, we observe a
very strong magnetic field dependence of the echo amplitude. Moreover, for the
first time we have direct evidence that magnetic fields change the phase of
coherent tunneling systems in a well-defined way. We present the data and
discuss the possible origin of this intriguing effect.Comment: 4 pages, 3 figures, submitted to PR
THE PREVALENCE OF PALPABLE FINGER JOINT NODULES IN DIFFUSE IDIOPATHIC SKELETAL HYPEROSTOSIS (DISH). A CONTROLLED STUDY
The presence of clinically palpable finger joint nodules a(Heberden's and Bouchard's nodes) was documented in 123 consecutive cases with diffuse idiopathic skeletal hyperostosis (DISH) of the thoracic spine and 191 matched DISH negative controls. The prevalence of palpable finger joint nodules was almost twice as frequent in cases with spinal DISH compared to controls (46% versus 31%, X2 = 7.67, P<0.01; multivariate adjusted odds ratio OR = 1.84; 95% CI: 1.14-2.98). This increase was most marked at the proximal interphalangeal joint, in males and in patients up to the age of 65 years. In addition and independent of other variables such as hyperostotic features, age and sex, the prevalence of palpable finger joint nodules was about twice as high in probands with a history of physically heavy work compared to those without (43% ver sus 26%, X = 9.18, P<0.005; multivariate adjusted odds ratio OR = 2.10; 95% CI: 1.26-3.52). From these results we con clude that DISH should be considered as an independent risk factor in the development of finger joint nodule
DIFFUSE IDIOPATHIC SKELETAL HYPEROSTOSIS (DISH) OF THE SPINE: A CAUSE OF BACK PAIN? A CONTROLLED STUDY
This is the first controlled study of the frequency of back pain in a European caucasian population with diffuse idiopathic skeletal hyperostosis (DISH). Elderly patients admitted to hospital for reasons other than back pain were assessed for the presence of spinal DISH using the routine lateral chest radiograph films. A total of 106 probands (82 males, 24 females) with a mean age of 70 years fulfilled the criteria for DISH as defined previously. One hundred and seventyeight patients (117 males, 61 females) not meeting these criteria were used as controls. The prevalence of back pain was assessed by a blinded interviewer using a structured questionnaire. Our primary hymthesis was that spinal DISH positive probands had not had back pain more often than controls. The controlled study showed no statistically significant difference in pain frequency between spinal DISH positive probands and controls at any spinal level. We conclude that back pain does not occur more often in radiographically defined DISH positive probands than in controls. The radiological finding of spinal DISH, as far as it does not lead to stenosis of the spinal canal or dysphagia, thus seems to be a finding without clinical relevanc
SEVERE OSTEOPOROSIS DUE TO SYSTEMIC MAST CELL DISEASE: SUCCESSFUL TREATMENT WITH INTERFERON ALPHA-2B
We describe a 33-yr-old man suffering from severe vertebral osteoporosis and urticaria pigmentosa due to systemic mast cell disease (SMCD). Because i.v. clodronate therapy could not prevent further vertebral fractures, an additional treatment with interferon alpha-2b was initiated. During 24 months of treatment, our patient had no further pain episodes, no new vertebral fractures were discovered, trabecular bone mineral density (BMD) increased significantly and urticarial symptoms improved. Nevertheless, the extent of skin lesions remained unchanged. On histological examination, a remarkable decrease of mast cells was observed in the bone marrow, but not in the skin. Five months after discontinuation of interferon alpha-2b, trabecular BMD decreased and urticarial symptoms deteriorated. These findings illustrate a beneficial effect of interferon alpha-2b on SMCD-induced osteoporosis as well as urticarial symptoms, and raise the question whether this treatment may have a diverse impact on mast cell populations in different tissue
Bio-Inspired Multi-Layer Spiking Neural Network Extracts Discriminative Features from Speech Signals
Spiking neural networks (SNNs) enable power-efficient implementations due to
their sparse, spike-based coding scheme. This paper develops a bio-inspired SNN
that uses unsupervised learning to extract discriminative features from speech
signals, which can subsequently be used in a classifier. The architecture
consists of a spiking convolutional/pooling layer followed by a fully connected
spiking layer for feature discovery. The convolutional layer of leaky,
integrate-and-fire (LIF) neurons represents primary acoustic features. The
fully connected layer is equipped with a probabilistic spike-timing-dependent
plasticity learning rule. This layer represents the discriminative features
through probabilistic, LIF neurons. To assess the discriminative power of the
learned features, they are used in a hidden Markov model (HMM) for spoken digit
recognition. The experimental results show performance above 96% that compares
favorably with popular statistical feature extraction methods. Our results
provide a novel demonstration of unsupervised feature acquisition in an SNN
DIFFUSE IDIOPATHIC SKELETAL HYPEROSTOSIS (DISH) OF THE SHOULDER: A CAUSE OF SHOULDER PAIN?
Shoulder pain is a common complaint and shoulder hyperostosis a frequent radiological condition. However, little is known about the association between the clinical and radiological findings. To evaluate the clinical relevance of shoulder hyperostosis we performed a controlled, blind study of 99 hospitalized probands with and without thoracospinal hyperostosis on lateral chest X-rays. The study included grading of the shoulder hyperostosis on the basis of three bilateral standard radiographs, assessing shoulder pain in a standardized way by an interviewer and recording extraskeletal causes of shoulder pain. The prevalence of shoulder hyperostosis was doubled in probands with thoracospinal hyperostosis compared to controls (X2= 5.90, F>0.025, n = 99). Shoulder hyperostosis, irrespective of thoracospinal hyperostosis, predisposed to shoulder pain (40% versus 18%, x2 = 4.06, F>0.05, n = 74). Shoulder hyperostosis in combination with thoracospinal hyperostosis (shoulder DISH) predisposed to shoulder pain to an even greater extent (46% versus 12%, x2 = 6.64, P>0.01, n = 47). We conclude that shoulder hyperostosis is a radiological finding of potential clinical relevanc
DIFFUSE IDIOPATHIC SKELETAL HYPEROSTOSIS (DISH) OF THE ELBOW: A CAUSE OF ELBOW PAIN? A CONTROLLED STUDY
Elbow pain is a common complaint and elbow hyperostosis a frequent radiological condition. However, little is known about the association between the clinical and radiological findings. To evaluate the relationship between spinal and extraspinal hyperostotic features and the clinical relevance of elbow hyperostosis we have performed the first controlled, double-blinded study of 85 hospitalized probands, 33 with and 52 without thoracospinal hyperostosis on lateral chest X-ray. Elbow and shoulder hyperostosis were graded on bilateral standard radiographs. Elbow pain was assessed by an interviewer using a standardized questionnaire and extraskeletal causes of elbow pain were recorded. The prevalence of elbow hyperostosis was increased in cases with thoracospinal hyperostosis compared to controls (82% versus 58%, X2 = 5.32, P<0.025, n = 85, odds ratio (OR) 3.30 (95% Cl 1.16-9.35)). Similarly, the prevalence of elbow hyperostosis was increased in cases with shoulder hyperostosis compared to controls (83% versus 60%, x2 = 4.51, P<0.05, n = 84, OR = 3.20 (95% CI 1.06-9.66)), emphasizing the multifocal nature of hyperostotic features. Elbow pain was only slightly more prevalent in cases with elbow hyperostosis compared to controls (21% versus l3%, x2 = 0.75, NS, OR = 1.84 (95% CI 0.46-7.44)). We conclude that elbow hyperostosis is a radiological finding of doubtful clinical relevanc
Maternal opioids age-dependently impair neonatal respiratory control networks
19 pagesInfants exposed to opioids in utero are an increasing clinical population and these
infants are often diagnosed with Neonatal Abstinence Syndrome (NAS). Infants
with NAS have diverse negative health consequences, including respiratory
distress. However, many factors contribute to NAS, confounding the ability to
understand how maternal opioids directly impact the neonatal respiratory system.
Breathing is controlled centrally by respiratory networks in the brainstem and
spinal cord, but the impact of maternal opioids on developing perinatal respiratory
networks has not been studied. Using progressively more isolated respiratory
network circuitry, we tested the hypothesis that maternal opioids directly impair
neonatal central respiratory control networks. Fictive respiratory-related motor
activity from isolated central respiratory networks was age-dependently impaired
in neonates after maternal opioids within more complete respiratory networks
(brainstem and spinal cords), but unaffected in more isolated networks (medullary
slices containing the preBötzinger Complex). These deficits were due, in part, to
lingering opioids within neonatal respiratory control networks immediately after
birth and involved lasting impairments to respiratory pattern. Since opioids are
routinely given to infants with NAS to curb withdrawal symptoms and our previous
work demonstrated acute blunting of opioid-induced respiratory depression in
neonatal breathing, we further tested the responses of isolated networks to
exogenous opioids. Isolated respiratory control networks also demonstrated
age-dependent blunted responses to exogenous opioids that correlated with
changes in opioid receptor expression within a primary respiratory rhythm
generating region, the preBötzinger Complex. Thus, maternal opioids agedependently
impair neonatal central respiratory control and responses to
exogenous opioids, suggesting central respiratory impairments contribute to
neonatal breathing destabilization after maternal opioids and likely contribute
to respiratory distress in infants with NAS. These studies represent a significant
advancement of our understanding of the complex effects of maternal opioids,
even late in gestation, contributing to neonatal breathing deficits, necessary first
steps in developing novel therapeutics to support breathing in infants with NAS
Atrial and placental melanoma metastasis: a case report and literature review
Malignant melanoma can metastasize to virtually any organ of the body. The aggressiveness is determined by the primary site, depth of dermal invasion, presence or absence of ulceration, lymphovascular infiltration and regional lymph node involvement. We report a case of a pregnant woman with a previous history of stage 3 melanoma who presented with cardiac metastasis and placental melanoma infiltration. A review of literature on cardiac and placental involvement of melanoma is also provided
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