Effects Of Physical Impairments Research Articles

Increasing attendance of patient support groups

Purpose: A critical care admission can be very traumatic to both patients and their families, with the effects of physical impairments and psychological stress being experienced sometime after discharge which can impede daily life. Research suggests that a critical care support group that connects critical care survivors and their families with others who have also experienced critical care may allow them to share, discuss and work together to overcome these impairments so as to improve the overall quality of life for patients and their families.

Effects of physical impairments on fitness correlates of the white-footed mouse, Peromyscus leucopus.

Physical impairments are widely assumed to reduce the viability of individual animals, but their impacts on individuals within natural populations of vertebrates are rarely quantified. By monitoring wild populations of white-footed mice over 26 years, we assessed whether missing or deformed limbs, tail or eyes influenced the survival, body mass, movement and ectoparasite burden of their bearers. Of the 27 244 individuals monitored, 543 (2%) had visible physical impairments. Persistence times (survival) were similar between mice with and without impairments. Mice with eye and tail impairments had 5% and 6% greater mass, respectively, than unimpaired mice. Mice with tail impairments had larger home ranges than did unimpaired mice. Burdens of black-legged ticks (Ixodes scapularis) were higher among mice with tail and limb impairments while burdens of bot fly larvae (Cuterebra) were higher among mice with cataracts compared to mice without impairments. Our findings do not support the presupposition that physical impairments reduce viability in their bearers and are inconsistent with the devaluation of impaired individuals that pervaded early thinking in evolutionary biology.

Physical Impairment Aware Virtual Optical Network Construction Algorithm with Service Differentiation in Elastic Optical Networks

Background: Elastic optical networks can support high data bit rates efficiently with its flexible wavelength grid, and with virtual optical networks, network resources can be managed simply. However, the signal may be deteriorated by the physical impairments. Therefore, service differentiation techniques have to consider the physical impairments. Objective: We propose a novel virtual optical network construction algorithm that provides service differentiation. Moreover, the effect of physical impairments is considered before constructing a virtual optical network. The goal of the proposed algorithm is to provide service differentiation in terms of the rejection rate of virtual optical network requests. Here, we consider the on-line scenario where the traffic is not known in advance. Methods: In the proposed method, each virtual optical network comprises two nodes and a lightpath between the two nodes. In our proposed method, service differentiation is provided by giving a higher (lower) acceptance rate for high (low) priority users. This method consists of four mechanisms; signaling mechanism, physical impairment estimation mechanism, resource check mechanism, and retransmission mechanism. Numerical Results: We evaluate by simulation the performance of the proposed method in NSFNET and European topologies. Analysis of the rejection rate as function of network load, impact of the network load on the number of retransmissions, and impact of network topology were discussed. Numerical results show that our method not only provides service differentiation but also reduces the overall rejection rate. Conclusion: We can conclude that our method is efficient compared to the conventional methods considering the scenario and topologies analyzed.

American Medical Association Impairment Ratings and Earnings Losses Due to Disability

Abstract The AMA Guides to the Evaluation of Permanent Impairment (AMA Guides) has been criticized because it was designed to measure the severity of impairment (loss of function of a body part) rather than disability (eg, inability to work), and the AMA Guides uses whole person impairment that accords higher priority to body regions that are deemed more important to functionality even though no objective evidence supports the relative importance of different body regions. This article reports on a study funded by the California Commission on Health and Safety and Workers’ Compensation (CHSWC) to address these concerns. The study found that the AMA Guides, Fifth Edition, is an effective tool for ranking the effect of physical impairments on the ability to work; people with higher physical impairment ratings, measured using the AMA Guides, consistently had higher earnings losses. The authors conclude that ratings based on the AMA Guides, Fifth Edition, probably are more accurate and consistent than ratings conducted under the previous system in California, the system used by the Veterans Administration, or systems used by Wisconsin and Florida in the 1960s. The authors also identified significant challenges to using ratings based on the AMA Guides to determine financial compensation, particularly across body regions, and some evidence suggests that the relationship between impairment ratings and losses was attenuated at higher ratings.

Impairment-aware QoS provisioning in dual-header OBS networks

Signal degradation due to physical impairments may result in unacceptable bit-error rates of received signals at the destination. Based on earlier work, we study the impairment-aware quality of service (QoS) provisioning problem in dual-header optical burst switching (OBS) networks that employ two control packets for each data burst. At an OBS node, the proposed algorithm schedule bursts for transmission by searching for available resources using admission control and preemption. The algorithm also verifies signal quality. Simulation results show that this algorithm is effective in providing QoS support in OBS networks while considering physical impairment effects.

Impairment-aware ordered scheduling in dual-header optical burst switched networks

Optical burst switching (OBS) is a promising technology for bridging the gap between optical wavelength switching and optical packet switching. Optical signal transmission quality is subject to various types of physical impairment introduced by optical fibers, switching elements, or other network components. The signal degradation due to physical impairment may be significant enough such that the bit-error rate of received signals is unacceptably high at the destination, rendering the signal to not usable. In this article, based on earlier study, we study the burst-scheduling problem in OBS networks using two control packets for each data burst, taking into account physical impairment effects. We propose a burst-scheduling algorithm that accommodates incoming bursts by primary path routing, deflection routing, and burst scheduling. We design an admission control mechanism to use network resources efficiently. At an OBS node, the proposed algorithm schedules bursts for transmission by searching for available resources as well as verifying signal quality. Our simulation results demonstrate that the proposed algorithm is effective in terms of reducing the burst-blocking probability.

Dynamic RWA with FWM-induced crosstalk awareness and modulation format conversion in wavelength-routed optical networks

The constraint of signal transmission quality and network resources utilization in transparent optical networks are herein addressed through a representative cost function based upon an impairment-constraint-base routing (ICBR) approach, taking into account link capacity utilization and the nonlinear physical effect, in the primary instance due to Four-Wave Mixing (FWM)-induced crosstalk. The FWM effect is considered one of the most severe physical impairments for the future photonic networks since the accumulation of FWM crosstalk may cause a fatal degradation in the teletraffic network performance. This paper presents an added functionality to the network model design based on all-optical modulation format conversion from conventional on-off keying (OOK) to quadrature phase-shift keying (QPSK) sending more data within the same bandwidth while minimizing the blocking probability. The joint effect of physical impairment (i.e., FWM-induced crosstalk) awareness and two different modulation formats is considered through numerical simulations. The proposed scheme is expected to realize an all-optical transparent interconnection between networks that employ diverse modulation formats. Results show that the proposed FWM-aware Routing and Wavelength Assignment (RWA) algorithm leads to a more realistic system performance while giving a significant improvement on the network performance.

Physical impairment aware scheduling in optical burst switched networks

Optical burst switching (OBS) presents itself as a promising technology for bridging the gap between optical wavelength switching and optical packet switching. Increasingly, researchers attempt to incorporate more realistic constraints into the design of OBS networks. Optical signal transmission quality is subject to various types of physical impairment introduced by optical fibers, switching equipment, or other network components. The signal degradation due to physical impairments may be significant enough such that the bit-error rate of received signals is unacceptably high at the destination, rendering the signal not usable. In this paper, based on earlier work, we study the burst scheduling problem in OBS networks, taking into account physical impairment effects. We propose three effective burst scheduling algorithms: (1) a JET based Physical Impairment Constrained Algorithm (JETPIC), (2) an Integrated Physical Impairment Constrained Algorithm (IPIC), and (3) an Enhanced Integrated Physical Impairment Constrained Algorithm (EIPIC). At an OBS node, the proposed algorithms schedule bursts for transmission by searching for available resources as well as verifying signal quality. Our simulation results show that the proposed algorithms are effective in terms of reducing the burst blocking probability. In general, algorithm JETPIC outperforms algorithms IPIC and EIPIC in burst blocking probability and average end-to-end delay performance.

Q-factor-based constraint routing improves performance in optical networks

In communication networks, routing involves the identification of a path between the source and destination nodes for each connection request. Traditional routing approaches find a path that minimizes a certain cost parameter, such as the length of the connection. Most of the reported routing and wavelength assignment algorithms (RWAs) assume that once an available path and wavelength have been identified, the connection is feasible. This may not be true in transparent optical networks using wavelength division multiplexing (WDM), where the optical signal experiences and accumulates the effects of physical impairments associated with the transmission line and optical switching nodes. In some cases, this results in unacceptable signal quality. Hence, impairment-constraint-based routing (ICBR) is needed in order to ensure that the connections are feasible. To do this, it is necessary to consider not only the network-level conditions but also the equally important physical performance of the connection. Previously we proposed an RWA that included an ICBR approach. Our technique took into account various physical impairments present in an optical network, and considered different problems independently. Here, a path was assumed to be feasible if a set of criteria reflecting the signal quality (in terms of the different impairments) is satisfied. Here we propose a scheme that integrates routing and wavelength assignment and also considers the physical performance of the network in an ICBR algorithm developed to achieve optimal network performance. This scheme takes into account— through detailed modelling—the various hardware issues and their interplay. This integrated approach produces an estimation of the signal quality (Q) factor and the associated penalties. Figure 1. An impairment-constraint-based routing (ICBR) algorithm optimizes and improves overall network performance with a lower percentage of blocked calls as compared to the performance achieved in a traditional shortest-path (SP) approach.

The effect of physical impairment on low back pain and disability on mothers of children with and without neuromuscular disorders

Abstract Introduction : Physical impairments such as inadequacy of muscle strength, endurance and flexibility may be lead to low back pain. The aim of this study was to compare of the effect of physical impairment on low back pain and disability on mothers of children with and without neuromuscular disorders. Methods : Mothers of children with muscular dystrophies (Group I, n = 30) and mothers of healthy children (Group II, n = 30) participated to the study. The mother muscle strength of trunk flexion and extension, flexibility of trunk extension and lateral flexion, and endurance of abdominal muscles were assessed. Body mass index of the mothers and children were recorded. Low back pain was assessed by Oswestry low back pain disability questionnaire (OLBQDS) and visual analogue scale (VAS). Results : There were positive correlations between children's body mass index, OLBQDS scores and VAS of mothers in both groups. A negative correlation was found between muscle strengths, flexibility and VAS in Group I...

Do You Really Have to Believe?

When an improbable team of losers, the 1969 New York Mets, won the World Series, they were inspired by a relief pitcher who would scream, “You gotta believe!” Perhaps Tug McGraw (who also was famous for saying, “I have no trouble with the twelve inches between my elbow and my palm. It's the seven inches between my ears that's bent”) knew something about the value of this mantra, a value that we could not discern because of his quirkiness. He was implying that belief shaped reality. Belief does not guarantee success, however, so we might ask whether the eccentric McGraw's message is really true. When a person is imprisoned in a home by extreme agoraphobia, we have no trouble seeing that mental disorder as the cause of disability. But when a lack of faith in physical capabilities, often as a result of justifiable fear, limits a person's activities, should we view this as a physical limitation or a problem due to a belief? If physical therapy interventions are to be effective, we need to discern how the effects of physical impairments might be different from psychological factors. Having a physical skill matters little if you are too uncomfortable or fearful to use it. In this issue, Miller and colleagues (pages 856–865) provide us with an intriguing report that deals with the issue of …

Difficulties in relationships between nonhandicapped and severely mentally retarded children: The effect of physical impairments

Difficulties in relationships between nonhandicapped and severely mentally retarded children (ages 8–12) were examined as a function of the presence or absence of additional physical handicapping conditions. Two sets of data, involving multiple codes of both the handicapped and nonhandicapped children's behavior, were analyzed and aggregated to address this issue. Findings suggested that nonhandicapped children work harder, receive and emit fewer social reinforcers, have less opportunity to play and have fun, and achieve lower levels of social play when their playmate is physically handicapped as well as severely mentally retarded. Implications for the longevity of social relationships with and the community survival of severely multiply handicapped persons are discussed. Strategies for increasing the reinforcement potential of relationships with multiply handicapped children are proposed for future research and implementation.

The effect of physical status on the affective expression of handicapped infants

This study investigated the ability of handicapped infants to express laughter in response to specific stimuli and examined the effect of physical impairment in limiting an individual child's ability to laugh. Results were interpreted as supporting the hypothesis that as the degree of muscle tone involvement increased from normal to mild, moderate or severe, the child's ability to laugh decreased. The associated decrement in laugh responses occurred whether the child was classed as hypotonic or hypertonic. The authors suggest that consideration of this physical component is important if one is to use the number of laughing responses to specific stimuli as a gauge of a muscle involved infant's cognitive status.