164 research outputs found

    Indoor visible light communication localization system utilizing received signal strength indication technique and trilateration method

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    Visible light communication (VLC) based on light-emitting diodes (LEDs) technology not only provides higher data rate for indoor wireless communications and offering room illumination but also has the potential for indoor localization. VLC-based indoor positioning using the received optical power levels from emitting LEDs is investigated. We consider both scenarios of line-of-sight (LOS) and LOS with non-LOS (LOSNLOS) positioning. The performance of the proposed system is evaluated under both noisy and noiseless channel as is the impact of different location codes on positioning error. The analytical model of the system with noise and the corresponding numerical evaluation for a range of signal-to-noise ratio (SNR) are presented. The results show that an accuracy of 12 dB

    Evaluation of an Emotional Support Service for the Visually Impaired

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    Purpose. To evaluate the impact of a facilitated peer group emotional support service on visual quality of life (VQoL). Methods. Consecutive participants in an emotional support service delivered to groups of up to 6 and facilitated by trained counsellors were recruited (n=29). The VCM1 instrument was administered to participants at the start of the service, at the end of the service, and 6 months after completion of the service. Results. For the group as a whole, VQoL significantly improved between the beginning of the service and the end (F(1, 23) =16.43, p=.000), but was no better than at the start six months later (F(1,23)=3.60, p=.07). However, those with poorer initial VQoL showed significantly greater improvements after six months (1.74Β±2.21 logits) than those with higher initial VQoL (-0.12Β±0.71 logits) (t(23)=2.89, p=.008). The effect size of the intervention for those with poor initial VQoL was 1.10 at the end of service, and 0.92 after six months. The items which became and remained easier were feeling lonely or isolated due to eyesight, feeling sad or low due to eyesight, and feeling worried about general safety outside the home. Conclusions. This facilitated peer group emotional support service significantly improves VQoL as assessed with the VCM1 over at least 6 months for those with poorer initial VQoL. Different interventions may be needed for those with initially good VQoL, and to improve other aspects of quality of life not influenced by the service

    Rehabilitation needs and activity limitations of adults with a visual impairment entering a low vision rehabilitation service in England

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    Purpose- To evaluate outcome measures of the Participation and Activity Inventory (PAI) in a sample of adults with acquired visual impairment entering vision rehabilitation. Both Priority Scores, indicating level of rehabilitative need, and Person Measures, indicating goal difficulty, were considered. Methods- Participants were newly registered adults with visual impairment within Leicestershire, United Kingdom. The importance and difficulty of 48 goals of the PAI were assessed, as were demographic factors, clinical visual function (visual acuity, contrast sensitivity, reading function) and psychosocial function (adjustment to visual loss, depression, anxiety and fear of falling). Priority scores were calculated as the product of importance and difficulty of each goal. All questionnaires were Rasch analysed, and person and item measures of perceived difficulty with goals were derived. Results- Sixty people (mean age Β± S.D. = 75.8 Β± 13.8 years) took part. PAI goals with greatest rehabilitative need were reading (6.82 Β± 2.91), mobility outdoors (6.55 Β± 3.92), mobility indoors within an unfamiliar environment (5.52 Β± 3.93) and writing (5.27 Β± 3.02). Greater rehabilitative need was associated with younger age (Ξ² = βˆ’0.46, p < 0.001), and with higher depressive symptomatology (Ξ² = 0.35, p < 0.01; model R2 34%). Goals with greatest difficulty were mending clothing (βˆ’1.95 Β± 0.35 logits) and hobbies and crafts (βˆ’1.32 Β± 0.23 logits). Greater difficulty was associated with higher depressive symptomatology (Ξ² = 0.39, p < 0.001), lower visual acuity (Ξ² = 0.42, p < 0.001) and lower adjustment of visual loss (Ξ² = 0.31, p < 0.01; model R2 53%). Conclusions- Key rehabilitation needs for adults at entry to services require both optical and non-optical interventions. As rehabilitative need was not associated with the level of visual impairment, eyecare professionals should not wait until the end of medical treatment before referral for support. Similarly, rehabilitative need was associated with younger age, indicating the importance to refer younger people with sight loss at an early stage. The use of structured assessment, such as the PAI, ensures goals that have an impact upon quality of life are specifically identified. Depression screening on entry to rehabilitation is relevant as it predicts both perceived difficulty and rehabilitative need

    An Examination of the Association of Selected Toxic Metals with Total and Central Obesity Indices: NHANES 99-02

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    It is conceivable that toxic metals contribute to obesity by influencing various aspects of metabolism, such as by substituting for essential micronutrients and vital metals, or by inducing oxidative stress. Deficiency of the essential metal zinc decreases adiposity in humans and rodent models, whereas deficiencies of chromium, copper, iron, and magnesium increases adiposity. This study utilized the NHANES 99-02 data to explore the association between waist circumference and body mass index with the body burdens of selected toxic metals (barium, cadmium, cobalt, cesium, molybdenum, lead, antimony, thallium, and tungsten). Some of the associations were significant direct relationships (barium and thallium), and some of the associations were significant inverse relationships (cadmium, cobalt, cesium, and lead). Molybdenum, antimony, and tungsten had mostly insignificant associations with waist circumference and body mass index. This is novel result for most of the toxic metals studied, and a surprising result for lead because high stored lead levels have been shown to correlate with higher rates of diabetes, and obesity may be a key risk factor for developing diabetes. These associations suggest the possibility that environmental exposure to metals may contribute to variations in human weight gain/loss. Future research, such as prospective studies rather than the cross-sectional studies presented here, is warranted to confirm these findings

    Usefulness and acceptability of a standardised orientation and mobility training for partially-sighted older adults using an identification cane

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    <p>Abstract</p> <p>Background</p> <p>Orientation and mobility (O&M) training in using an identification (ID) cane is provided to partially-sighted older adults to facilitate independent functioning and participation in the community. Recently, a protocolised standardised O&M-training in the use of the ID cane was developed in The Netherlands. The purpose of this study is to assess the usefulness and acceptability of both the standardised training and the regular training for participants and O&M-trainers in a randomised controlled trial (NCT00946062).</p> <p>Methods</p> <p>The standardised O&M-training consists of two structured face-to-face sessions and one telephone follow-up, in which, in addition to the regular training, self-management and behavioural change techniques are applied. Questionnaires and interviews were used to collect data on the training’s usefulness, e.g. the population reached, self-reported benefits or achievements, and acceptability, e.g. the performance of the intervention according to protocol and participants’ exposure to and engagement in the training.</p> <p>Results</p> <p>Data was collected from 29 O&M-trainers and 68 participants. Regarding the self-reported benefits, outcomes were comparable for the standardised training and the regular training according the trainers and participants e.g., about 85% of the participants in both groups experienced benefits of the cane and about 70% gained confidence in their capabilities. Participants were actively involved in the standardised training. Nearly 40% of the participants in the standardised training group was not exposed to the training according to protocol regarding the number of sessions scheduled and several intervention elements, such as action planning and contracting.</p> <p>Conclusions</p> <p>The standardised and regular O&M-training showed to be useful and mostly acceptable for the partially-sighted older adults and trainers. Yet, a concern is the deviation from the protocol of the standardised O&M-training by the O&M-trainers regarding distinguishing elements such as action planning. Overall, participants appreciated both trainings and reported benefit.</p

    ACVIM consensus statement: Guidelines for the identification, evaluation, and management of systemic hypertension in dogs and cats

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    An update to the 2007 American College of Veterinary Internal Medicine (ACVIM) consensus statement on the identification, evaluation, and management of systemic hypertension in dogs and cats was presented at the 2017 ACVIM Forum in National Harbor, MD. The updated consensus statement is presented here. The consensus statement aims to provide guidance on appropriate diagnosis and treatment of hypertension in dogs and cats

    Transcription regulation of the Escherichia coli pcnB gene coding for poly(A) polymerase I: roles of ppGpp, DksA and sigma factors

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    Poly(A) polymerase I (PAP I), encoded by the pcnB gene, is a major enzyme responsible for RNA polyadenylation in Escherichia coli, a process involved in the global control of gene expression in this bacterium through influencing the rate of transcript degradation. Recent studies have suggested a complicated regulation of pcnB expression, including a complex promoter region, a control at the level of translation initiation and dependence on bacterial growth rate. In this report, studies on transcription regulation of the pcnB gene are described. Results of in vivo and in vitro experiments indicated that (a) there are three Οƒ70-dependent (p1, pB, and p2) and two ΟƒS-dependent (pS1 and pS2) promoters of the pcnB gene, (b) guanosine tetraphosphate (ppGpp) and DksA directly inhibit transcription from pB, pS1 and pS2, and (c) pB activity is drastically impaired at the stationary phase of growth. These results indicate that regulation of the pcnB gene transcription is a complex process, which involves several factors acting to ensure precise control of PAP I production. Moreover, inhibition of activities of pS1 and pS2 by ppGpp and DksA suggests that regulation of transcription from promoters requiring alternative Οƒ factors by these effectors of the stringent response might occur according to both passive and active models
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