566 research outputs found

    Introducing mobile home agents into the distributed authentication protocol to achieve location privacy in mobile IPv6

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    Mobile IPv6 will be the basis for the fourth generation 4G networks which will completely revolutionize the way telecommunication devices operate. This paradigm shift will occur due to the sole use of packed switching networks. Mobile IPv6 utilizes binding updates as a route optimization to reduced triangle routing between the mobile node, the home agent and the correspondent node, allowing direct communication between the mobile node and the correspondent. However, direct communication between the nodes produces a range of security vulnerabilities, which the home agent avoided. This paper attempts to provide the advantages of using the home agent as an intermediary whilst reducing the latency of triangle routing. This can be achieved with the proposed use of a mobile home agent which essentially follows the mobile node as it moves between points of attachment providing location privacy and pseudo-direct communication, which can be incorporated into the distributed authentication protocol or be used as a stand alone solution

    Online educational repositories for promoting agricultural knowledge

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    Systolic blood pressure reactions to acute stress are associated with future hypertension status in the Dutch Famine Birth Cohort Study

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    These analyses examined the association between blood pressure reactions to acute psychological stress and subsequent hypertension status in a substantial Dutch cohort. Blood pressure was recorded during a resting baseline and during three acute stress tasks, Stroop colour word, mirror tracing and speech. Five years later, diagnosed hypertension status was determined by questionnaire. Participants were 453 (237 women) members of the Dutch Famine Birth Cohort. In analysis adjusting for a number of potential confounders, systolic blood pressure reactivity was positively related to future hypertension. This was the case irrespective of whether reactivity was calculated as the peak or the average response to the stress tasks. The association was strongest for reactions to the speech and Stroop tasks. Diastolic blood pressure reactivity was not significantly associated with hypertension. The results provide support for the reactivity hypothesis. \ud \u

    Changes in the Prevalence of Child and Youth Mental Disorders and Perceived Need for Professional Help between 1983 and 2014: Evidence from the Ontario Child Health Study

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    Objectives: To examine: 1) changes in the prevalence of mental disorders and perceived need for professional help among children (ages 4 to 11) and youth (ages 12 to 16) between 1983 and 2014 in Ontario and 2) whether these changes vary by age and sex, urban-rural residency, poverty, lone-parent status, and immigrant background. Methods: The 1983 (n = 2836) and 2014 (n = 5785) Ontario Child Health Studies are provincially representative cross-sectional surveys with identical self-report checklist measures of conduct disorder, hyperactivity, and emotional disorder, as well as perceived need for professional help, assessed by integrating parent and teacher responses (ages 4 to 11) and parent and youth responses (ages 12 to 16). Results: The overall prevalence of perceived need for professional help increased from 6.8% to 18.9% among 4- to 16-year-olds. An increase in any disorder among children (15.4% to 19.6%) was attributable to increases in hyperactivity among males (8.9% to 15.7%). Although the prevalence of any disorder did not change among youth, conduct disorder decreased (7.2% to 2.5%) while emotional disorder increased (9.2% to 13.2%). The prevalence of any disorder increased more in rural and small to medium urban areas versus large urban areas. The prevalence of any disorder decreased for children and youth in immigrant but not nonimmigrant families. Conclusions: Although there have been decreases in the prevalence of conduct disorder, increases in other mental disorders and perceived need for professional help underscore the continued need for effective prevention and intervention programs

    Children’s Mental Health Need and Expenditures in Ontario: Findings from the 2014 Ontario Child Health Study

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    Objective: To estimate the alignment between the Ontario Ministry of Children and Youth Services (MCYS) expenditures for children’s mental health services and population need, and to quantify the value of adjusting for need in addition to population size in formula-based expenditure allocations. Two need definitions are used: “assessed need,” as the presence of a mental disorder, and “perceived need,” as the subjective perception of a mental health problem. Methods: Children’s mental health need and service contact estimates (from the 2014 Ontario Child Health Study), expenditure data (from government administrative data), and population counts (from the 2011 Canadian Census) were combined to generate formula-based expenditure allocations based on 1) population size and 2) need (population size adjusted for levels of need). Allocations were compared at the service area and region level and for the 2 need definitions (assessed and perceived). Results: Comparisons were made for 13 of 33 MCYS service areas and all 5 regions. The percentage of MCYS expenditure reallocation needed to achieve an allocation based on assessed need was 25.5% at the service area level and 25.6% at the region level. Based on perceived need, these amounts were 19.4% and 27.2%, respectively. The value of needs-adjustment ranged from 8.0% to 22.7% of total expenditures, depending on the definition of need. Conclusion: Making needs adjustments to population counts using population estimates of children’s mental health need (assessed or perceived) provides additional value for informing and evaluating allocation decisions. This study provides much-needed and current information about the match between expenditures and children’s mental health need

    Detection of gait initiation Failure in Parkinson's disease based on wavelet transform and Support Vector Machine

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    © 2017 IEEE. Gait initiation Failure (GIF) is the situation in which patients with Parkinson's disease (PD) feel as if their feet get 'stuck' to the floor when initiating their first steps. GIF is a subtype of Freezing of Gait (FOG) and often leads to falls and related injuries. Understanding of neurobiological mechanisms underlying GIF has been limited by difficulties in eliciting and objectively characterizing such gait phenomena in the clinical setting. Studies investigating the effects of GIF on brain activity using EEG offer the potential to study such behavior. In this preliminary study, we present a novel methodology where wavelet transform was used for feature extraction and Support Vector Machine for classifying GIF events in five patients with PD and FOG. To deal with the large amount of EEG data, a Principal Component Analysis (PCA) was applied to reduce the data dimension from 15 EEG channels into 6 principal components (PCs), retaining 93% of the information. Independent Component Analysis using Entropy Bound Minimization (ICA-EBM) was applied to 6 PCs for source separation with the aim of improving detection ability of GIF events as compared to the normal initiation of gait (Good Starts). The results of this analysis demonstrated the correct identification of GIF episodes with an 83.1% sensitivity, 89.5% specificity and 86.3% accuracy. These results suggest that our proposed methodology is a promising non-invasive approach to improve GIF detection in PD and FOG

    Phase-dependent spectra in a driven two-level atom

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    We propose a method to observe phase-dependent spectra in resonance fluorescence, employing a two-level atom driven by a strong coherent field and a weak, amplitude-fluctuating field. The spectra are similar to those which occur in a squeezed vacuum, but avoid the problem of achieving squeezing over a 4Ď€4\pi solid angle. The system shows other interesting features, such as pronounced gain without population inversion.Comment: 4 pages and 4 figures. Submitted to Phys. Rev. Let

    Children’s Mental Health Need and Expenditures in Ontario: Findings from the 2014 Ontario Child Health Study

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    Objective: To estimate the alignment between the Ontario Ministry of Children and Youth Services (MCYS) expenditures for children’s mental health services and population need, and to quantify the value of adjusting for need in addition to population size in formula-based expenditure allocations. Two need definitions are used: “assessed need,” as the presence of a mental disorder, and “perceived need,” as the subjective perception of a mental health problem. Methods: Children’s mental health need and service contact estimates (from the 2014 Ontario Child Health Study), expenditure data (from government administrative data), and population counts (from the 2011 Canadian Census) were combined to generate formula-based expenditure allocations based on 1) population size and 2) need (population size adjusted for levels of need). Allocations were compared at the service area and region level and for the 2 need definitions (assessed and perceived). Results: Comparisons were made for 13 of 33 MCYS service areas and all 5 regions. The percentage of MCYS expenditure reallocation needed to achieve an allocation based on assessed need was 25.5% at the service area level and 25.6% at the region level. Based on perceived need, these amounts were 19.4% and 27.2%, respectively. The value of needs-adjustment ranged from 8.0% to 22.7% of total expenditures, depending on the definition of need. Conclusion: Making needs adjustments to population counts using population estimates of children’s mental health need (assessed or perceived) provides additional value for informing and evaluating allocation decisions. This study provides much-needed and current information about the match between expenditures and children’s mental health need

    Poverty, Neighbourhood Antisocial Behaviour, and Children’s Mental Health Problems: Findings from the 2014 Ontario Child Health Study

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    Objectives: To determine if levels of neighbourhood poverty and neighbourhood antisocial behaviour modify associations between household poverty and child and youth mental health problems. Methods: Data come from the 2014 Ontario Child Health Study—a provincially representative survey of 6537 families with 10,802 four- to 17-year-olds. Multivariate multilevel modelling was used to test if neighbourhood poverty and antisocial behaviour interact with household poverty to modify associations with children’s externalizing and internalizing problems based on parent assessments of children (4- to 17-year-olds) and self-assessments of youth (12- to 17-year-olds). Results: Based on parent assessments, neighbourhood poverty, and antisocial behaviour modified associations between household poverty and children’s mental health problems. Among children living in households below the poverty line, levels of mental health problems were 1) lower when living in neighbourhoods with higher concentrations of poverty and 2) higher when living in neighbourhoods with more antisocial behaviour. These associations were stronger for externalizing versus internalizing problems when conditional on antisocial behaviour and generalized only to youth-assessed externalizing problems. Conclusion: The lower levels of externalizing problems reported among children living in poor households in low-income neighbourhoods identify potential challenges with integrating poorer households into more affluent neighbourhoods. More important, children living in poor households located in neighbourhoods exhibiting more antisocial behaviour are at dramatically higher risk for mental health problems. Reducing levels of neighbourhood antisocial behaviour could have large mental health benefits, particularly among poor children

    Changes in the Prevalence of Child and Youth Mental Disorders and Perceived Need for Professional Help between 1983 and 2014: Evidence from the Ontario Child Health Study

    Get PDF
    Objectives: To examine: 1) changes in the prevalence of mental disorders and perceived need for professional help among children (ages 4 to 11) and youth (ages 12 to 16) between 1983 and 2014 in Ontario and 2) whether these changes vary by age and sex, urban-rural residency, poverty, lone-parent status, and immigrant background. Methods: The 1983 (n = 2836) and 2014 (n = 5785) Ontario Child Health Studies are provincially representative cross-sectional surveys with identical self-report checklist measures of conduct disorder, hyperactivity, and emotional disorder, as well as perceived need for professional help, assessed by integrating parent and teacher responses (ages 4 to 11) and parent and youth responses (ages 12 to 16). Results: The overall prevalence of perceived need for professional help increased from 6.8% to 18.9% among 4- to 16-year-olds. An increase in any disorder among children (15.4% to 19.6%) was attributable to increases in hyperactivity among males (8.9% to 15.7%). Although the prevalence of any disorder did not change among youth, conduct disorder decreased (7.2% to 2.5%) while emotional disorder increased (9.2% to 13.2%). The prevalence of any disorder increased more in rural and small to medium urban areas versus large urban areas. The prevalence of any disorder decreased for children and youth in immigrant but not nonimmigrant families. Conclusions: Although there have been decreases in the prevalence of conduct disorder, increases in other mental disorders and perceived need for professional help underscore the continued need for effective prevention and intervention programs
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