The information needs of people living with ankylosing spondylitis: a questionnaire survey

<p>BACKGROUND:Today, health care is patient-centred with patients more involved in medical decision making and taking an active role in managing their disease. It is important that patients are appropriately informed about their condition and that their health care needs are met. We examine the information utilisation, sources and needs of people with ankylosing spondylitis (AS).</p> <p>METHODS: Participants in an existing AS cohort study were asked to complete a postal or online questionnaire containing closed and open-ended questions, regarding their information access and needs. Participants were stratified by age and descriptive statistics were performed using STATA 11, while thematic analysis was performed on open-ended question narratives. Qualitative data was handled in Microsoft Access and explored for emerging themes and patterns of experiences.</p> <p>RESULTS: Despite 73% of respondents having internet access, only 49% used the internet to access information regarding AS. Even then, this was only infrequently. Only 50% of respondents reported accessing written information about AS, which was obtained mainly in specialist clinics. Women were more likely than men to access information (63% (women) 46% (men)) regardless of the source, while younger patients were more likely to use online sources. The main source of non-written information was the rheumatologist. Overall, the respondents felt there was sufficient information available, but there was a perception that the tone was often too negative. The majority (95%) of people would like to receive a regular newsletter about AS, containing positive practical and local information. Suggestions were also made for more information about AS to be made available to non-specialist medical professionals and the general public.</p> <p>CONCLUSIONS: There appears to be sufficient information available for people with AS in the UK and this is mostly accessed by younger AS patients. Many patients, particularly men, choose not to access AS information and concerns were raised about its negative tone. Patients still rely on written and verbal information from their specialists. Future initiatives should focus on the delivery of more positive information, targeting younger participants in particular and increasing the awareness in the general population and wider non-specialist medical community.</p&gt

A Novel Estimator for the Rate of Information Transfer by Continuous Signals

The information transfer rate provides an objective and rigorous way to quantify how much information is being transmitted through a communications channel whose input and output consist of time-varying signals. However, current estimators of information content in continuous signals are typically based on assumptions about the system's linearity and signal statistics, or they require prohibitive amounts of data. Here we present a novel information rate estimator without these limitations that is also optimized for computational efficiency. We validate the method with a simulated Gaussian information channel and demonstrate its performance with two example applications. Information transfer between the input and output signals of a nonlinear system is analyzed using a sensory receptor neuron as the model system. Then, a climate data set is analyzed to demonstrate that the method can be applied to a system based on two outputs generated by interrelated random processes. These analyses also demonstrate that the new method offers consistent performance in situations where classical methods fail. In addition to these examples, the method is applicable to a wide range of continuous time series commonly observed in the natural sciences, economics and engineering

Psychopathic traits and offender characteristics – a nationwide consecutive sample of homicidal male adolescents

<p>Abstract</p> <p>Background</p> <p>The aim of the study was to evaluate psychopathy-like personality traits in a nationwide consecutive sample of adolescent male homicide offenders and to compare the findings with those of a randomly sampled adult male homicide offender group. A further aim was to investigate associations between psychopathic traits and offender and offence characteristics in adolescent homicides.</p> <p>Methods</p> <p>Forensic psychiatric examination reports and crime reports of all 15 to19- year- old male Finnish offenders who had been subjected to a forensic psychiatric examination and convicted for a homicide during 1995–2004 were collected (n = 57). A random sample of 57 adult male homicide offenders was selected as a comparison group. Offence and offender characteristics were collected from the files and a file-based assessment of psychopathic traits was performed using the Hare Psychopathy Checklist-Revised (PCL-R) by trained raters.</p> <p>Results</p> <p>No significant differences existed between the adolescents and adults in PCL-R total scores, factor 2 (social deviance) scores, or in facets 3 (lifestyle) and 4 (antisocial). Adults scored significantly higher on factor 1 (interpersonal/affective) and facets 1 (interpersonal) and 2 (affective). The adolescent group was divided into two subgroups according to PCL-R total scores. One in five homicidal male adolescents met criteria for psychopathic personality using a PCL-R total score of 26 or higher. These boys significantly more often had a crime history before the index homicide, more frequently used excessive violence during the index homicide, more rarely lived with both parents until 16 years of age, had more institutional or foster home placements in childhood, had more school difficulties, more often had received special education, and, more often had contact with mental health services prior to age 18 years than boys scoring low on the PCL-R. They also more often had parental criminal history as well as homicide history of parents or near relatives than the group scoring low on the PCL-R.</p> <p>Conclusion</p> <p>Homicidal boys behaved as antisocially as the homicidal adults. The adults, however, showed more both affective and interpersonal features of psychopathy. Homicidal adolescents with psychopathy-like personality character form a special subgroup among other homicidal youngsters. Recognizing their characteristics, especially in life course development, would facilitate effective prevention and intervention efforts.</p

Characterization of Quasi-Stationarity Regions for Vehicle-to-Vehicle Radio Channels

We analyze the nonwide-sense-stationarity (nonWSS) of vehicle-to-vehicle (V2V) radio channels using three metrics: 1) the correlation matrix distance (CMD); 2) the wideband spectral divergence (SD); and 3) the shadow fading correlation. The analysis is based on measurements carried out at 5.3 GHz using a 30 × 4 MIMO system in suburban, urban, and underground parking areas. Several factors such as the existence of a line-of-sight (LOS), the speed of cars, and the antenna array size and configuration are considered in the analysis of non-WSS. It is found that quasi-stationarity region ranges from 3 to 80 m in different V2V scenarios, and is strongly affected by the above factors. Based on the comparison of the equivalent quasi-stationarity region size estimated by the three metrics, it is suggested to use SD and shadowing correlation metrics for systems with small electrical array apertures and to use CMD metric only for arrays with large electrical apertures

A Dynamic Wideband Directional Channel Model for Vehicle-to-Vehicle Communications

Vehicle-to-vehicle (V2V) communications have received a lot of attention due to their numerous applications in traffic safety. The design, testing, and improvement of the V2V system hinge critically on the understanding of the propagation channels. An important feature of the V2V channel is the time variance. To statistically model the time-variant V2V channels, a dynamic wideband directional channel model is proposed in this paper, based on measurements conducted at 5.3 GHz in suburban, urban, and underground parking environments. The model incorporates both angular and delay domain properties and the dynamic evolution of multipath components (MPCs). The correlation matrix distance is used to determine the size of local wide-sense stationary (WSS) region. Within each WSS time window, MPCs are extracted using the Bartlett beamformer. A multipath distance-based tracking algorithm is used to identify the “birth” and “death” of such paths over different stationarity regions, and the lifetime of MPC is modeled with a truncated Gaussian distribution. Distributions for the number of multipaths and their positions are statistically modeled. Within each path lifetime, the initial power is found to depend on the excess delay, and a linear polynomial function is used to model the variations within the lifetime. In addition, a Nakagami distribution is suggested to describe the fading behavior. Finally, the model implementation is validated by comparison of second-order statistics between measurements and simulations

Vehicle-to-Vehicle Radio Channel Characterization in Crossroad Scenarios

Vehicle-to-vehicle (V2V)-communication-based collision avoidance systems detect if two vehicles are on a collision course (e.g., in crossroads, intersections, and highway merging), and they are particularly useful in the absence of line of sight (LOS) owing to buildings, roadside infrastructures, and road bending. Relying on radio measurements using a 4 × 30 multiple-input-multiple-output (MIMO) system at 5.3 GHz, this paper presents the results of an empirical study of V2V propagation channels in two suburban crossroad scenarios, where vehicles are either moving in the same direction and separate from each other along different roads or pass each other in opposite directions at the crossing. The quasi-stationarity interval is first characterized using correlation matrix distance (CMD). Small-scale fading follows a Nakagami distribution based on the Akaike information criteria (AIC). Delay and angular dispersions are found to be significantly affected by the type of crossroad and the presence of an LOS. Cross-correlation coefficients between delay dispersion, angular dispersion, and small-scale fading behavior are also evaluated. By comparing the results of the different crossroads, it is found that the delay and angular dispersions are large in the first type of crossroad. By contrast, in the second type of crossroad, small delay and angular dispersions are observed due to road bending and obstruction by roadside trees

Non-stationarity Characterization for Vehicle-to-vehicle Channels Using Correlation Matrix Distance and Shadow Fading Correlation

Vehicle-to-Vehicle (V2V) radio channels have been considered as non-stationary due to the dynamic scatterers in V2V environments. To characterize its stationarity is of great importance as it determines the time-variant V2V channel statistics. Therefore, we analyze the non-stationarity of V2V radio channels using two metrics: the correlation matrix distance (CMD) and the shadow fading correlation. The analysis is based on the measurements conducted in a suburban area of Finland at 5.3 GHz. We use the Aalto channel sounder and a 30 £ 4 MIMO system. The power delay pro¯le (PDP), CMD, and shadowing are estimated from the measured channel impulse responses. The equivalent stationarity distance is found to be around 6 m, and it is observed that regions with large delay spreads correspond to smaller stationarity regions. The shadow fading auto-correlation coe±cient is found to follow an exponential decay model and the decorrelation distance is considered as the shadowing-based equivalent stationarity distance. Based on the comparison of the equivalent stationarity distances estimated by the two metrics, it is found that the CMD metric is more sensitive to the changes of direction-of-arrival/departure, whereas the shadowing metric takes only into account the power variations over time. We also note that the estimation of shadowing metric is close to the results from CMD. This shows that the shadow correlation can also be used to characterize the non-stationarity of radio channels