Automatic spiral analysis for objective assessment of motor symptoms in Parkinson's disease

Objective: To develop a method for objective quantification of PD motor symptoms related to Off episodes and peak dose dyskinesias, using spiral data gathered by using a touch screen telemetry device. The aim was to objectively characterize predominant motor phenotypes (bradykinesia and dyskinesia), to help in automating the process of visual interpretation of movement anomalies in spirals as rated by movement disorder specialists. Background: A retrospective analysis was conducted on recordings from 65 patients with advanced idiopathic PD from nine different clinics in Sweden, recruited from January 2006 until August 2010. In addition to the patient group, 10 healthy elderly subjects were recruited. Upper limb movement data were collected using a touch screen telemetry device from home environments of the subjects. Measurements with the device were performed four times per day during week-long test periods. On each test occasion, the subjects were asked to trace pre-drawn Archimedean spirals, using the dominant hand. The pre-drawn spiral was shown on the screen of the device. The spiral test was repeated three times per test occasion and they were instructed to complete it within 10 seconds. The device had a sampling rate of 10Hz and measured both position and time-stamps (in milliseconds) of the pen tip. Methods: Four independent raters (FB, DH, AJ and DN) used a web interface that animated the spiral drawings and allowed them to observe different kinematic features during the drawing process and to rate task performance. Initially, a number of kinematic features were assessed including ‘impairment’, ‘speed’, ‘irregularity’ and ‘hesitation’ followed by marking the predominant motor phenotype on a 3-category scale: tremor, bradykinesia and/or choreatic dyskinesia. There were only 2 test occasions for which all the four raters either classified them as tremor or could not identify the motor phenotype. Therefore, the two main motor phenotype categories were bradykinesia and dyskinesia. ‘Impairment’ was rated on a scale from 0 (no impairment) to 10 (extremely severe) whereas ‘speed’, ‘irregularity’ and ‘hesitation’ were rated on a scale from 0 (normal) to 4 (extremely severe). The proposed data-driven method consisted of the following steps. Initially, 28 spatiotemporal features were extracted from the time series signals before being presented to a Multilayer Perceptron (MLP) classifier. The features were based on different kinematic quantities of spirals including radius, angle, speed and velocity with the aim of measuring the severity of involuntary symptoms and discriminate between PD-specific (bradykinesia) and/or treatment-induced symptoms (dyskinesia). A Principal Component Analysis was applied on the features to reduce their dimensions where 4 relevant principal components (PCs) were retained and used as inputs to the MLP classifier. Finally, the MLP classifier mapped these components to the corresponding visually assessed motor phenotype scores for automating the process of scoring the bradykinesia and dyskinesia in PD patients whilst they draw spirals using the touch screen device. For motor phenotype (bradykinesia vs. dyskinesia) classification, the stratified 10-fold cross validation technique was employed. Results: There were good agreements between the four raters when rating the individual kinematic features with intra-class correlation coefficient (ICC) of 0.88 for ‘impairment’, 0.74 for ‘speed’, 0.70 for ‘irregularity’, and moderate agreements when rating ‘hesitation’ with an ICC of 0.49. When assessing the two main motor phenotype categories (bradykinesia or dyskinesia) in animated spirals the agreements between the four raters ranged from fair to moderate. There were good correlations between mean ratings of the four raters on individual kinematic features and computed scores. The MLP classifier classified the motor phenotype that is bradykinesia or dyskinesia with an accuracy of 85% in relation to visual classifications of the four movement disorder specialists. The test-retest reliability of the four PCs across the three spiral test trials was good with Cronbach’s Alpha coefficients of 0.80, 0.82, 0.54 and 0.49, respectively. These results indicate that the computed scores are stable and consistent over time. Significant differences were found between the two groups (patients and healthy elderly subjects) in all the PCs, except for the PC3. Conclusions: The proposed method automatically assessed the severity of unwanted symptoms and could reasonably well discriminate between PD-specific and/or treatment-induced motor symptoms, in relation to visual assessments of movement disorder specialists. The objective assessments could provide a time-effect summary score that could be useful for improving decision-making during symptom evaluation of individualized treatment when the goal is to maximize functional On time for patients while minimizing their Off episodes and troublesome dyskinesias.

Aging studies on conducting polypyrrole

Change of tensile properties, electrical conductivity and microwave shielding of electrochemically synthesized polypyrrole films with time are presented. Highly doped films had good electrical stability, retaining high microwave reflectivity throughout the aging period. Lightly doped films were less stable and partially reflective and absorptive of microwaves. FT-IR spectral observations revealed a progressive increase in intensity of an unsaturated conjugated carbonyl peak, which was not observed in the highly doped films, suggesting that the concentration of the dopant had an influence on the mechanism of degradation of conductivity.

Lower permian oncolites from South China: implications for equatorial sea-level responses to late palaeozoic Gondwanan glaciation

The oncoid-bearing Chuanshan Formation is a regionally extensive carbonate deposit of predominantly Asselian to early Sakmarian (Early Permian) age in South China, occupying an area of some 500,000 km2. Throughout South China, the oncoid-bearing horizons are generally stable and broadly comparable in lithology, fossil content and the morphology of the oncoid grains. Four types of microfacies are recognized from the oncolite succession and overall they suggest a moderate- to high-energy, wave-agitated shallow marine carbonate platform environment. An analysis of the stratigraphic distribution of oncoid grain size, density, thickness and the bedding structures of the oncolite beds and the number of coating laminae indicate the presence of metre-scale cyclothems, suggestive of possible high-frequency cycles of sea-level fluctuation. Compared to carbonate successions above and below that lack oncolites, and in conjunction with evidence from sequence stratigraphic and isotopic geochemical analyses of coeval carbonate deposits in South China and elsewhere, the origin of the Chuanshan oncolites is linked to a drastic drop in global sea-level at the Pennsylvanian–Permian boundary, that can be correlated closely in timing with the zenith of the Late Palaeozoic Gondwanan glaciation. It is further suggested that the eustatic changes apparent from the deposition of the Chuanshan oncolites and similar coeval deposits in lower palaeolatitudes were coupled with, and influenced by, the contemporaneous high-latitude Gondwanan glaciation, the largest and longest known such event in Phanerozoic Earth history.

Globally privileged citizenship

Educators interested in social change have been using an analysis of privilege in their gender and anti-racist work for some time. Through working with adult Australians in a community education programme on asylum seekers, the applicability of an analysis of privilege to the exclusionary discourses concerning asylum seekers and refugees became clear. This paper argues that possessing citizenship of a safe, stable and materially comfortable country (globally privileged citizenship) provides similar unearned assets as does Whiteness, maleness and other characteristics of dominant groups. Through an analysis of citizenship we reverse the gaze that sees refugees and asylum seekers as the problem and place it on those of us who occupy the privileged position. Alternative approaches to exclusionary discourses of citizenship, asylum seekers and refugees are canvassed.

Conductive fabrics for heating applications

By coating textiles with electrically conductive organic polymers, we are able to produce functional, intelligent fabrics. These fabrics can be utilised in applications such as gas sensors, actuators, electromagnetic shielding, radar absorption, selected frequency filtering in indoor wireless applications, and heating applications where vital parts of the body can be heated without embedding any wiring through the fabric.

Heat generation in fabrics coated with the conductive polymer polypyrrole was investigated. The fabrics were coated by chemical synthesis methods by oxidizing the pyrrole monomer in the presence of the fabric substrate. Ferric chloride was selected as the oxidizing agent and anthraquinone-2-sulfonic acid (AQSA) sodium salt monohydrate as the dopant.

Conductive fabrics were characterized by resistivity measurements, scanning electron microscopy, thermal imaging, current transmission over a period of time and calculations of power density per unit area. Effects of reaction conditions on the electrical properties and heat generated are presented. Polypyrrole coated fabrics were stable and possessed high electrical conductivity. Resistivity values ranged from 100-500 ohms/square depending on the reaction parameters. When subjected to a constant voltage of 24V, the polypyrrole coated polyester-Lycra® fabric doped with AQSA reached a maximum temperature of 42°C and a power density per unit area of 430 W/m² was achieved.

Interventions to reduce harm associated with adolescent substance use

A major proportion of the disease burden and deaths for young people in developed nations is attributable to misuse of alcohol and illicit drugs. Patterns of substance use established in adolescence are quite stable and predict chronic patterns of use, mortality, and morbidity later in life. We integrated fi ndings of systematic reviews to summarise evidence for interventions aimed at prevention and reduction of harms related to adolescent substance use. Evidence of efficacy was available for developmental prevention interventions that aim to prevent onset of harmful patterns in settings such as vulnerable families, schools, and communities, and universal strategies to reduce attractiveness of substance use. Regulatory interventions aim to increase perceived costs and reduce availability and accessibility of substances. Increasing price, restricting settings of use, and raising legal purchase age are eff ective in reducing use of alcohol and tobacco and related harms. Screening and brief intervention are efficacious, but efficacy of a range of treatment approaches has not been reliably established. Harm-reduction interventions are effective in young people involved in risky and injecting substance use.

Stability of body mass index in Australian children: a prospective cohort study across the middle childhood years

Objective: To investigate the prevalence and incidence of overweight and obesity, the frequency of overweight resolution and the influence of parental adiposity during middle childhood.

Design: As part of a prospective cohort study, height and weight were measured in 1997 and 2000/2001. Children were classified as non-overweight, overweight or obese based on standard international definitions. Body mass index (BMI) was transformed into age- and gender-specific Z-scores employing the LMS method and 2000 growth chart data of the Centers for Disease Control and Prevention. Parents self-reported height and weight, and were classified as underweight, healthy weight, overweight or obese based on World Health Organization definitions.

Setting: Primary schools in Victoria, Australia.

Subjects: In total, 1438 children aged 5–10 years at baseline.

Results: The prevalence of overweight and obesity increased between baseline (15.0 and 4.3%, respectively) and follow-up (19.7 and 4.8%, respectively; P < 0.001 for increase in overweight and obesity combined). There were 140 incident cases of overweight (9.7% of the cohort) and 24 of obesity (1.7% of the cohort); only 3.8% of the cohort (19.8% of overweight/obese children) resolved to a healthy weight. The stability of child adiposity as measured by BMI category (84.8% remained in the same category) and BMI Z-score (r = 0.84; mean change = −0.05) was extremely high. Mean change in BMI Z-score decreased with age (linear trend β = 0.03, 95% confidence interval 0.01–0.05). The influence of parental adiposity largely disappeared when children's baseline BMI was adjusted for.

Conclusions: During middle childhood, the incidence of overweight/obesity exceeds the proportion of children resolving to non-overweight. However, for most children adiposity remains stable, and stability appears to increase with age. Prevention strategies targeting children in early childhood are required.

Doubling fish exports or garment exports : which would benefit the Fijian economy most? Evidence from a computable general equilibrium model

The need to diversify Fiji's export base has been identified as an important avenue for reducing Fiji's vulnerabilities in international trade. This paper poses the question: Doubling fish exports or garment exports: which would be most beneficial for the Fijian economy? To achieve the goal of this paper, the computable general equilibrium model is used, this being at the forefront of research on 'impact studies'. The main finding is that when garment exports and fish exports are doubled, the benefits to the Fijian economy are greater from garment exports, suggesting that the latter has stronger linkages with the rest of the economy. On the basis of this finding, policymakers should divert resources towards sustaining the garment industry whose future is uncertain due to expiring trade agreements and unstable economic policies.

Guideline-based programs in the treatment of complex PTSD

The term “post-traumatic stress disorder” (PTSD) is a relatively new diagnostic label, being formally recognized in 1980 in the Diagnostic Statistical Manual for Psychiatric Illness – Third Edition (DSM-III) of the American Psychiatric Association (APA, 1980). Complex Post-Traumatic Stress Disorder (CP) is a more recently discussed, and newly-classified, phenomenon, initially discussed in the early 1990s (Herman, 1992a). Thus, as research into effective treatments for CP is sparse, the treatment of CP is the topic of this study, in which a guideline-based treatment program developed by the researcher for the treatment of CP is implemented and evaluated. Ten individuals participated in this study, undertaking individualized, guideline-based treatment programs spanning a period of six months. In providing background information relevant to this study, an explanation is provided regarding the nature of CP, and the reasons for its consideration as a separate phenomenon to PTSD. The adequacy of the PTSD formulation in enabling effective assessment and treatment of CP is also explored, with endorsement of previous researchers’ conclusions that the CP construct is more useful than the PTSD construct for assessing and treating survivors of long-term and multiple forms of abuse. The PTSD classification is restrictive, and not necessarily appropriate for certain forms of trauma (such as prolonged trauma, or multiple forms of trauma), as such trauma experiences may lead to specific effects that lay outside those formerly associated with PTSD. Such effects include alterations in affect regulation, consciousness, self-perception, interpersonal relationships, and in systems of meaning. Following discussion regarding the PTSD/CP classification, an examination of treatment methods currently used in the treatment of PTSD, and a review of treatment outcome studies, takes place. The adequacy of primary treatment methods in treating CP symptoms is then examined, with the conclusion that a range of treatment methods could potentially be useful in the treatment of CP symptoms. Individuals with a diagnosis of CP may benefit from the adoption of an eclectic approach, drawing on different treatment options for different symptoms, and constantly evaluating client progress and re-evaluating interventions. This review of treatment approaches is followed by details of an initial study undertaken to obtain feedback from individuals who had suffered long-term/multiple trauma and who had received treatment. Participants in this initial study were asked open-ended questions regarding the treatment approach they had experienced, the most useful aspect of the treatment, the least useful aspect, and other strategies/treatment approaches that may have been useful – but which were not used. The feedback obtained from these individuals was used to inform the development of treatment guidelines for use in the main study, as were recommendations made by Chu (1998). The predominant focus of the treatment guidelines was “ego strengthening”, a term coined by Chu (1998) to describe the “initial (sometimes lengthy) period of developing fundamental skills in maintaining supportive relationships, developing self-care strategies, coping with symptomatology, improving functioning, and establishing a positive self identity” (p.75). Using a case study approach, data are then presented relating to each of the ten individuals involved in the treatment program: details of his/her trauma experience(s)and the impact of the trauma (as perceived by each individual); details of each individual’s treatment program (as planned, and as implemented); post-treatment evaluation of the positive and negative aspects of the treatment program (from the therapist’s perspective); and details of the symptoms reported by the individual post-treatment, via psychometric assessment and also during interview. Analysis and discussion of the data relating to the ten participants in the study are the focal point of this study. The evaluation of the effectiveness of each individual’s treatment has been based predominantly on qualitative data, obtained from an analysis of language (discourse analysis) used by participants to describe their symptoms pre- and post-treatment. Both blatant and subtle changes in the language used by participants to describe themselves, their behaviour, and their relationships pre- and post-treatment have provided an insight into the possible changes that occurred as a result of the treatment program. The language used by participants has been a rich source of data, one that has enabled the researcher to obtain information that could not be obtained using psychometric assessment methods. Most of the participants in this study portrayed notable changes in many of the CP symptoms, including being more stable and having improved capacity to explore their early abuse. Although no direct cause-effect relationship between the participants’ treatment program and the improvements described can be established from this study, the participants’ perception that the program assisted them with their symptoms, and reported many aspects of “ego strengthening”, is of major importance. Such self-perception of strength and empowerment is important if an individual is going to be able to deal with past trauma experiences. In fact, abreactive work may have a greater chance of succeeding if those who have experienced long-term or multiple trauma are feeling more empowered, and more stable, as were the participants in this study (post-intervention). In concluding this study, recommendations have been made in regard to the use of guideline-based treatment programs in the responsible treatment of CP. Strengths and limitations of this study have also been highlighted, and recommendations have been made regarding possibilities for future research related to CP treatment. On the whole, this study has supported strongly other research that highlights the importance of focusing on “ego strengthening” in assisting those who have suffered long-term/multiple trauma experiences. Thus, a guideline-based program focusing on assisting sufferers of long-term trauma with some, or all, of the symptoms of CP, is recommended as an important first stage of any treatment of individuals who have experienced long-term/multiple trauma, allowing them to develop the emotional and psychological strength required to deal with past traumatic events. Clinicians who are treating patients whose history depicts long-term or multiple trauma experiences (either from their childhood, or at some stage in their adult life) need, therefore, to be mindful of assessing individuals for symptoms of CP – so that they can treat these symptoms prior to engaging in any work associated directly with the past traumatic experiences.

Variations in vascular access flows in haemodialysis can depend on needle orientation

Introduction: While using the Transonic Qc[TM] machine to assess access flow in arteriovenous fistulae (AVF), we observed that when compared to antegrade arterial needle insertion, retrograde arterial needle insertion could regularly produce lower access flow measurements. This study sought to explore this phenomenon.

Method: 23 patients entered and 20 finished the study. Patient selection criteria included: functioning AVF and an adequate AVF length for either retrograde or antegrade arterial needle insertion. After ensuring stable and similar blood pressures, 3 flow measurements were taken during the first 2 hours on the same dialysis day of 3 consecutive weeks using antegrade needle insertion then were repeated on 3 further consecutive weeks using retrograde insertion.

Results: Overall, access flows measured with retrograde insertion were significantly lower by a mean difference of 107.15 ml/min (57-484 ml/min) than the flows measured with antegrade needle placement. In 5/20, 3 recorded minimal difference and 2 had a higher access flows during retrograde insertion. No recirculation was observed during either antegrade or retrograde needle insertion. The paired t-test showed that there was significant difference between the antegrade versus retrograde mean measurements (p = 0.005).

Conclusion: Although the sample size is small and the number of measurements limited, we conclude that access flows may be greater with an antegrade arterial orientation compared to flows recorded with a retrograde orientation. The phenomenon behind this conclusion is yet to be investigated. We suggest that when using the Transonic Qc[TM] access measurement device the arterial needle should always be in the same direction for each measurement for each individual patient.

A robust set-valued state estimation approach to the problem of vision based SLAM for mobile robots

The problem of visual simultaneous localization and mapping (SLAM) is examined in this paper using ideas and algorithms from robust control and estimation theory. Using a stereo-vision based sensor, a nonlinear measurement model is derived which leads to nonlinear measurements of the landmark coordinates along with optical flow based measurements of the relative robot-landmark velocity. Using a novel analytical measurement transformation, the nonlinear SLAM problem is converted into the linear filter is guaranteed stable and the ALAM state estimation error is bounded within an ellipsoidal set. No similar results are available for the commonly employed extended Kalman filter which is known to exhibit divergent and inconsistency characteristics in practice.

Reliable downloading algorithms for bittorrent-like systems

In this paper we study a reliable downloading algorithm for BitTorrent-like systems, and attest it in mathematics. BitTorrent-like systems have become immensely popular peer-to-peer file distribution tools in the internet in recent years. We analyze them in theory and point out some of their limitations especially in reliability, and propose an algorithm to resolve these problems by using the redundant copies in neighbors in P2P networks and can further optimize the downloading speed in some condition. Our preliminary simulations show that the proposed reliable algorithm works well; the improved BitTorrent-like systems are very stable and reliable.

Stability of oxide films formed on mild steel in turbulent flow conditions of alkaline solutions at elevated temperatures

In the industries involving alkaline solutions in different process streams, the nature and stability of oxide films formed on the metallic surfaces determine the rates of erosion–corrosion of the equipment. In the present study the characteristics of the oxide films formed on AISI 1020 steel in a 2.75 M sodium hydroxide solution at temperatures up to 175°C, have been investigated by employing electrochemical techniques of cyclic voltammetry and chronoamperometry. The experiments were carried out in an autoclave system based upon a ‘rotating cylinder electrode’ geometry to determine the effects of turbulence on the stability of the films. The results suggest that little protection is afforded in the active region (at about −0.8 V_SHE). In the passive region at low potentials (−0.6 V to −0.4 V_SHE), it appears the films are compact and more stable, and therefore provide good protection. At higher potentials (>−0.4 V_SHE) in the passive region, the results suggest that film formation and dissolution occur simultaneously and the increase in temperature and turbulence causes a breakdown of the passive film resulting in a situation similar to nonprotective magnetite growth.

Disulfides as redox switches : from molecular mechanisms to functional significance

The molecular mechanisms underlying thiol-based redox control are poorly defined. Disulfide bonds between Cys residues are commonly thought to confer extra rigidity and stability to their resident protein, forming a type of proteinaceous spot weld. Redox biologists have been redefining the role of disulfides over the last 30–40 years. Disulfides are now known to form in the cytosol under conditions of oxidative stress. Isomerization of extracellular disulfides is also emerging as an important regulator of protein function. The current paradigm is that the disulfide proteome consists of two subproteomes: a structural group and a redox-sensitive group. The redoxsensitive group is less stable and often associated with regions of stress in protein structures. Some characterized redox-active disulfides are the helical CXXC motif, often associated with thioredoxin-fold proteins; and forbidden disulfides, a group of metastable disulfides that disobey elucidated rules of protein stereochemistry. Here we discuss the role of redox-active disulfides as switches in proteins.

Polar transformation system for offline handwritten character recognition

Offline handwritten recognition is an important automated process in pattern recognition and computer vision field. This paper presents an approach of polar coordinate-based handwritten recognition system involving Support Vector Machines (SVM) classification methodology to achieve high recognition performance. We provide comparison and evaluation for zoning feature extraction methods applied in Polar system. The recognition results we proposed were trained and tested by using SVM with a set of 650 handwritten character images. All the input images are segmented (isolated) handwritten characters. Compared with Cartesian based handwritten recognition system, the recognition rate is more stable and improved up to 86.63%.