Temporary carbon storage and discount rates

Several approaches have been proposed for accounting for temporary carbon sequestration in land-use change and forestry projects that are implemented to offset permanent emissions of carbon dioxide from the energy sector. In a previous paper, we evaluated the incentives provided by some of these approaches. In this paper, we investigate further what we call the “ideal” accounting system, where the forest owner would be paid for carbon sequestration as the service is provided and redeem payments when the forest is harvested and carbon is released back into the atmosphere. We demonstrate how discounting affects the net present value of the forest when carbon sequestration is taken into account under this ideal system. Not all carbon is released back into the atmosphere at harvest, however, since a large proportion may remain fixed in forest products for many years. Here, we compare the profitability of the forest under full redemption of credits at harvest, with partial redemption of credits at harvest followed by annual redemption post-harvest as the carbon decays in a durable forest product. The analysis is based on simulation of farm-forestry systems in south-eastern Australia.carbon accounting, reforestation, discounting, bioeconomics, Environmental Economics and Policy, Land Economics/Use,

A survey to investigate the association of pain, foot disability and quality of life with corns

Background Corns are a common foot problem affecting a large proportion of the population. This study describes the characteristics of corns experienced by 201 participants taking part in a randomised controlled trial to investigate associations between demographic and corn parameters on pain, foot related disability and quality of life (QoL). Methods Pain from the main (index) corn was measured using a visual analogue scale (VAS); foot related disability was assessed with the Foot Disability Questionnaire (now known as the Manchester Foot Pain and Disability Index) and quality of life was recorded with the EQ-5D questionnaire. The effect of demographic and corn parameters on the pain and quality of life outcomes was assessed with analysis of variance (ANOVA) methods. The effect of the same factors on a linear combination of the foot-related disability outcome measures was assessed using multivariate ANOVA methods. Pain was also tested for its mediating properties on the causal pathway between the independent variables and quality of life. Results The mean pain score was 5.29 points on a 10 cm VAS, with females reporting substantively higher pain levels than males. Age affected foot-related disability, with lower levels on all domains of the MFPDI reported in older participants; each year of advancing age was associated with falls of: 0.009 points on the Concern about Appearance (CA) domain; 0.047 points on the Functional Limitation (FL) domain and 0.048 points on the Pain Intensity (PI) domain. Sex and corn type also affected disability, with higher scores reported by females and participants with plantar corns. Conclusions The effect of pain was shown to mediate the relationship between sex and foot-related disability. The presence of plantar corns has a more detrimental effect on QoL than dorsal/inter-digital corns

Distribution and correlates of plantar hyperkeratotic lesions in older people

<p>Abstract</p> <p>Background</p> <p>Plantar hyperkeratotic lesions are common in older people and are associated with pain, mobility impairment and functional limitations. However, little has been documented in relation to the frequency or distribution of these lesions. The aim of this study was to document the occurrence of plantar hyperkeratotic lesions and the patterns in which they occur in a random sample of older people.</p> <p>Methods</p> <p>A medical history questionnaire was administered to a random sample of 301 people living independently in the community (117 men, 184 women) aged between 70 and 95 years (mean 77.2, SD 4.9), who also underwent a clinical assessment of foot problems, including the documentation of plantar lesion locations, toe deformities and the presence and severity of hallux valgus.</p> <p>Results</p> <p>Of the 301 participants, 180 (60%) had at least one plantar hyperkeratotic lesion. Those with plantar lesions were more likely to be female (χ²= 18.75, <it>p </it>< 0.01; OR = 2.86), have moderate to severe hallux valgus (χ²= 6.15, <it>p </it>< 0.02; OR = 2.95), a larger dorsiflexion range of motion at the ankle (39.4 ± 9.3 <it>vs </it>36.3 ± 8.4°; <it>t </it>= 2.68, <it>df </it>= 286, <it>p </it>< 0.01), and spent more time on their feet at home (5.1 ± 1.0 <it>vs </it>4.8 ± 1.3 hours, <it>t </it>= -2.46, <it>df </it>= 299, <it>p </it>= 0.01). No associations were found between the presence of plantar lesions and body mass index, obesity, foot posture, dominant foot or forefoot pain. A total of 53 different lesions patterns were observed, with the most common lesion pattern being "roll-off" hyperkeratosis on the medial aspect of the 1^stmetatarsophalangeal joint (MPJ), accounting for 12% of all lesion patterns. "Roll-off" lesions under the 1^stMPJ and interphalangeal joint were significantly associated with moderate to severe hallux valgus (<it>p </it>< 0.05), whereas lesions under the central MPJs were significantly associated with deformity of the corresponding lesser toe (<it>p </it>< 0.05). Factor analysis indicated that 62% of lesion patterns could be grouped under three broad categories, relating to medial, central and lateral locations.</p> <p>Conclusion</p> <p>Plantar hyperkeratotic lesions affect 60% of older people and are associated with female gender, hallux valgus, toe deformity, increased ankle flexibility and time spent on feet, but are not associated with obesity, limb dominance, forefoot pain or foot posture. Although there are a wide range of lesion distribution patterns, most can be classified into medial, central or lateral groups. Further research is required to determine whether these patterns are related to the dynamic function of the foot or other factors such as foot pathology or morphology.</p

Age and gender differences in disabling foot pain using different definitions of the manchester foot pain and disability index

Extent: 9p.Background: The Manchester Foot Pain and Disability Index (MFPDI) has been used to determine the prevalence of disabling foot pain in several studies, however there is some debate as to which case definition is most appropriate. The objective of this study was to explore age and gender differences in the proportion of people with disabling foot pain using three different case definitions of the MFPDI and for each individual MFPDI item. Methods: A random sample of 223 participants aged 27 to 90 years (88 males and 135 females) from the North West Adelaide Health Study, who reported having pain, aching or stiffness in either of their feet on most days in the last month, completed the MFPDI by telephone interview. The proportion of people with disabling foot pain was determined using three definitions: (i) Definition A-at least one of the 17 items documented on at least some days in the last month; (ii) Definition B-at least one of the 17 items documented on most/every day(s) in the last month, and; (iii) Definition C-at least one of the ten functional limitation items documented on most/every day(s) in the last month. Cross-tabulations and chi-squared statistics were used to explore differences in responses to the MFPDI items according to age and gender. Results: The proportion of people with disabling foot pain according to each definition was as follows: Definition A (100%), Definition B (95.1%) and Definition C (77.6%). Definition C was most sensitive to age and gender differences. Exploration of individual MFPDI items indicated that age significantly affected both the pain intensity and functional limitation items, with younger people more likely to report their foot pain being worse in the morning, and older people more likely to report functional limitations. Although gender did not influence responses to the personal appearance items, women were more likely report functional limitations than men. Conclusions: Definition C of the MFPDI is more sensitive to age and gender differences in the proportion of people with disabling foot pain, and would therefore seem to be the most appropriate case definition to use in epidemiological studies involving a broad age range of participants.Hylton B Menz, Tiffany K Gill, Anne W Taylor and Catherine L Hil

Prevalence and correlates of foot pain in a population-based study: the North West Adelaide health study

Background: Few population-based studies have examined the prevalence of foot pain in thegeneral community. The aims of this study were therefore to determine the prevalence, correlatesand impact of foot pain in a population-based sample of people aged 18 years and over living in the northwest region of Adelaide, South Australia.Methods: The North West Adelaide Health Study is a representative longitudinal cohort study ofn = 4,060 people randomly selected and recruited by telephone interview. The second stage of datacollection on this cohort was undertaken between mid 2004 and early 2006. In this phase,information regarding the prevalence of musculoskeletal conditions was included. Overall, n = 3,206 participants returned to the clinic during the second visit, and as part of the assessment were asked to report whether they had pain, aching or stiffness on most days in either of their feet. Data were also collected on body mass index (BMI); major medical conditions; other joint symptoms and health-related quality of life (the Medical Outcomes Study Short Form 36 [SF-36]).Results: Overall, 17.4% (95% confidence interval 16.2 – 18.8) of participants indicated that theyhad foot pain, aching or stiffness in either of their feet. Females, those aged 50 years and over,classified as obese and who reported knee, hip and back pain were all significantly more likely to report foot pain. Respondents with foot pain scored lower on all domains of the SF-36 afteradjustment for age, sex and BMI.Conclusion: Foot pain affects nearly one in five of people in the community, is associated withincreased age, female sex, obesity and pain in other body regions, and has a significant detrimental impact on health-related quality of life.Catherine L Hill, Tiffany K Gill, Hylton B Menz and Anne W Taylo

An improved method for mobility prediction using a Markov model and density estimation

This is the author accepted manuscript. The final version is available from IEEE via the DOI in this recordThe prediction of an individual's future locations is a significant part of scientific researches. While a variety of solutions have been investigated for the prediction of future locations, predicting departure and arrival times at predicted locations is a task with higher complexity and less attention. While the challenges of combining spatial and temporal information have been stated in various works, the proposed solutions lack accuracy and robustness. This paper proposes a simple yet effective way to predict not only an individual's future location, but also most probable departure and arrival times as well as the most probable route from origin to destination

Validity of self-assessment of hallux valgus using the Manchester scale

<p>Abstract</p> <p>Background</p> <p>Hallux valgus (HV) is a common condition involving the progressive subluxation of the first metatarsophalangeal joint due to lateral deviation of the hallux and medial deviation of the first metatarsal. The objective of this study was to evaluate the re-test reliability and validity of self-assessment of HV using a simple clinical screening tool involving four standardised photographs (the Manchester scale), in order to determine whether this tool could be used for postal surveys of the condition.</p> <p>Methods</p> <p>HV was assessed with the Manchester scale in 138 people aged 65 to 93 years of age (102 women and 36 men) as part of a larger randomised controlled trial. At the six month follow-up assessment, HV was reassessed to determine re-test reliability, and participants were asked to self-assess their degree of HV independent of the examiners. Associations between (i) baseline and follow-up assessments of the examiners and (ii) participant and examiner assessments were performed using weighted kappa statistics. Analyses were then repeated after HV was dichotomised as present or absent using unweighted kappa, and sensitivity and specificity of self-assessment of HV was determined.</p> <p>Results</p> <p>Re-test reliability of the examiners was substantial to almost perfect (weighted kappa = 0.78 to 0.90), and there was a substantial level of agreement between observations of the participants and the examiners (weighted kappa = 0.71 to 0.80). Overall, there was a slight tendency for participants to rate their HV as less severe than the examiners. When the Manchester scale scores were dichotomised, agreement was substantial to almost perfect for both re-test comparisons (kappa = 0.80 to 0.89) and substantial for comparisons between participants and examiners (kappa = 0.64 to 0.76). The sensitivity and specificity of self-assessment of HV using the dichotomous scale were 85 and 88%, respectively.</p> <p>Conclusions</p> <p>The Manchester scale demonstrates high re-test reliability, and self-assessment scores obtained by participants are strongly associated with scores obtained by examiners. These findings indicate that the tool can be used with confidence in postal surveys to document the presence and severity of HV.</p> <p>Trial registration</p> <p>ACTRN12608000065392</p

Identifying atypical travel patterns for improved medium-term mobility prediction

This is the author accepted manuscript. The final version is available from IEEE via the DOI in this recordDuring the last decades, concepts of Intelligent Transportation Systems (ITS) were continuously adapted and improved based on new insights into human travel behavior. Drivers for improvements are the quantity and quality of available mobility data, which increased significantly in recent years. Based on travel behavior, literature proposes a large number of different solutions for next step or future location prediction. However a holistic spatio-temporal prediction, which could further improve the quality of ITS, creates a more complex task. The prediction of medium-term mobility for one to seven days is challenging in particular for atypical travel behavior, since the weekdays’ order delivers no reliable indication for the next day’s travel behavior. With our contribution, we explore the benefits of various prediction approaches for medium-term mobility prediction and combine them dynamically to predict individual mobility behavior for a period of one week. The derived framework utilizes an exhaustive search approach to benefit from a machine learning based clustering method on location data. In conjunction with an Artificial Neural Network, the prediction framework is robust against prediction errors created by atypical behavior. With two data sets consisting of smartphone and vehicle data, we demonstrate the framework’s real-world applicability. We show that clustering an individual’s historical movement data can improve the prediction accuracy of different prediction methods that will be explained in detail and illustrate the interrelation of entropy and prediction accuracy.University of Exete