Semantic variation operators for multidimensional genetic programming

Multidimensional genetic programming represents candidate solutions as sets of programs, and thereby provides an interesting framework for exploiting building block identification. Towards this goal, we investigate the use of machine learning as a way to bias which components of programs are promoted, and propose two semantic operators to choose where useful building blocks are placed during crossover. A forward stagewise crossover operator we propose leads to significant improvements on a set of regression problems, and produces state-of-the-art results in a large benchmark study. We discuss this architecture and others in terms of their propensity for allowing heuristic search to utilize information during the evolutionary process. Finally, we look at the collinearity and complexity of the data representations that result from these architectures, with a view towards disentangling factors of variation in application.Comment: 9 pages, 8 figures, GECCO 201

Employment Statys, Job Type and Employer Description Among Persons with a Significant Visual Impairment in New Zealand

A random sample of 150 working aged members of the Royal New Zealand Foundation of the Blind were canvassed about their employment status, the sector in which they were employed and the types of jobs they held. It was found that although 39% were currently in paid employment, 64% indicated that they 'mostly have had paid employment’ or had 'always had paid employment ' since reaching working age. When asked about the position they currently held, 46% said they worked in the private sector, 24% said they were employed in the public sector, and 25% said they were self-employed; 5% responded as 'other’. In terms of the types of jobs they were in, 29% said they were in sales or service, 23% in professional or managerial positions, 13% in clerical positions, 14% in unskilled labour, 8% in skilled labour, 2% in technical jobs; 14% responded as 'other '. When asked to rate their current position in terms of their skills or abilities, 30% rated it as either 'way too low’, or as 'a bit too low; while, 70% rated as about right. A number of demographic variables were investigated to see if they had an effect on the positions held

Prevalence of QoI resistance and mtDNA diversity in the Irish Zymoseptoria tritici population

peer-reviewedThe emergence and spread of Quinone outside Inhibitor (QoI) fungicide resistance in the Irish Zymoseptoria tritici population in the early 2000s had immediate impacts on the efficacy of the entire group of fungicides for the control of septoria tritici blotch. As a result, a dramatic reduction in the quantities applied to winter wheat occurred in the following seasons. Even in the absence of these fungicides, the frequency of the resistance allele, G143A in the pathogens mtDNA has remained exceptionally high (>97%), and as such, it can be anticipated that continued poor efficacy of current QoI fungicides will be observed. Amongst the isolates with G143A, differences in sensitivity to the QoI pyraclostrobin were observed in vitro. The addition of the alternative oxidase (AOX) inhibitor salicylhydroxamic acid increased sensitivity in these isolates, suggesting some continued impairment of respiration by the QoI fungicides, albeit weak. Interestingly, amongst those tested, the strains from a site with a high frequency of inserts in the MFS1 transporter gene known to enhance QoI efflux did not exhibit this increase in sensitivity. A total of 19 mtDNA haplotypes were detected amongst the 2017 strain collection. Phylogenetic analysis confirmed the suggestion of a common ancestry of all the haplotypes, even though three of the haplotypes contained at least one sensitive strain

Production of Energy-dependent Time Delays in Impulsive Solar Flare Hard X-Ray Emission by Short-Duration Spectral Index Variations

Cross-correlation techniques have been used recently to study the relative timing of solar flare hard X-ray emission at different energies. These studies find that for the majority of the impulsive flares observed with BATSE there is a systematic time delay of a few tens of milliseconds between low (approximate to 50 keV) and higher energy emission (approximate to 100 keV). These time delays have been interpreted as energy-dependent time-of-flight differences for electron propagation from the corona, where they are accelerated, to the chromosphere, where the bulk of the hard X-rays are emitted. We show in this paper that crosscorrelation methods fail if the spectral index of the flare is not constant. BATSE channel ratios typically display variations of factors of 2 to 5 over time intervals as short as a few seconds. Using simulated and observed data, we demonstrate that cross-correlating energy channels with identical timing characteristics, but with variations in the amplitudes of one or a small number of relatively strong emission spikes, produces asymmetric time delays of either sign. The reported time delays are therefore largely due to spectral index variations and are not signatures of time-of-flight effects

Pilot Safety Evaluation of Varenicline for the Treatment of Methamphetamine Dependence.

Despite the worldwide extent of methamphetamine dependence, no medication has been shown to effectively treat afflicted individuals. One relatively unexplored approach is modulation of cholinergic system function. Animal research suggests that enhancement of central cholinergic activity, possibly at nicotinic acetylcholine receptors (nAChRs), can reduce methamphetamine-related behaviors. Further, preliminary findings indicate that rivastigmine, a cholinesterase inhibitor, may reduce craving for methamphetamine after administration of the drug in human subjects. We therefore performed a double-blind, placebo-controlled, crossover pilot study of the safety and tolerability of varenicline in eight methamphetamine-dependent research subjects. Varenicline is used clinically to aid smoking cessation, and acts as a partial agonist at α4β2 nAChRs with full agonist properties at α7 nAChRs. Oral varenicline dose was titrated over 1 week to reach 1 mg bid, and then was co-administered with 30 mg methamphetamine, delivered in ten intravenous infusions of 3 mg each. Varenicline was found to be safe in combination with IV methamphetamine, producing no cardiac rhythm disturbances or alterations in vital sign parameters. No adverse neuropsychiatric sequelae were detected either during varenicline titration or following administration of methamphetamine. The results suggest that varenicline warrants further investigation as a potential treatment for methamphetamine dependence

The end of the partnership with a guide dog: emotional responses, effects on quality of life and relationships with subsequent dogs

Guide dogs are mobility aids that facilitate independent travel of people who are blind or visually impaired. Additional benefits imparted to the guide dog handler include companionship, and increased: social-function, self-esteem and confidence. Some evidence shows that the end of the guide dog partnership can result in reduced mobility, and may have profound psychosocial effects on the handler due to feelings of bereavement and loss of self-esteem. However, this evidence is limited. This study examined the experiences and feelings of 36 people across New Zealand, who experienced the ending of at least one partnership with a guide dog (77 pairings), to explore issues arising at the end of the partnership and how this may impact on relationships with subsequent dogs. Results indicate that the majority of handlers experienced a reduction in their quality of life due to a decrease in independent mobility followed by the loss of a friend and companion, curtailment of social interactions, and loss of self-esteem/confidence. The end of the partnership affected people in different ways. Most handlers “accepted” the partnership had ended, but some felt guilty or angry with the guide dog school. Most applied for another dog immediately, as the need for mobility was high, while others preferred to wait and a smaller number did not reapply. Feelings at this time also affected the handlers’ relationships with subsequent guide dogs, with over a quarter expressing a negative effect. Retiring a guide dog (for whatever reason) is not only difficult for the handler, but also for the handler’s family, friends, co-workers, and doubtlessly, the dog. The majority of handlers expressed feelings of extreme grief when the partnership ended, whether it was successful or not. Feelings of extreme grief were more common for first than subsequent dogs. The depth of emotion was compared to losing a family member or other loved one, which has been reported in some person and pet relationships. A better understanding of issues surrounding the end of the partnership, including the human-animal bond, will help inform the guide dog industry of how best to support their clients during this time and when transitioning to another dog. Findings may be applied to other service/assistance dog users and the pet owning community

An investigation of the complexities of successful and unsuccessful guide dog matching and partnerships.

Matching a person who is blind or visually impaired with a guide dog is a process of finding the most suitable guide dog available for that individual. Not all guide dog partnerships are successful, and the consequences of an unsuccessful partnership may result in reduced mobility and quality of life for the handler (owner), and are costly in time and resources for guide dog training establishments. This study examined 50 peoples' partnerships with one or more dogs (118 pairings) to ascertain the outcome of the relationship. Forty-three of the 118 dogs were returned to the guide dog training establishment before reaching retirement age, with the majority (n = 40) being categorized as having dog-related issues. Most (n = 26) of these dogs' issues were classified as being behavioral in character, including work-related and non-work-related behavior, and 14 were due to physical causes (mainly poor health). Three dogs were returned due to matters relating to the handlers' behavior. More second dogs were returned than the handlers' first or third dogs, and dogs that had been previously used as a guide could be rematched successfully. Defining matching success is not clear-cut. Not all dogs that were returned were considered by their handlers to have been mismatched, and not all dogs retained until retirement were thought to have been good matches, suggesting that some handlers were retaining what they considered to be a poorly matched dog. Almost all the handlers who regarded a dog as being mismatched conceded that some aspects of the match were good. For example, a dog deemed mismatched for poor working behavior may have shown good home and/or other social behaviors. The same principle was true for successful matches, where few handlers claimed to have had a perfect dog. It is hoped that these results may help the guide dog industry identify important aspects of the matching process, and/or be used to identify areas where a matching problem exists

An investigation of the complexities of successful and unsuccessful guide dog matching and partnerships

Matching a person who is blind or visually impaired with a guide dog is a process of finding the most suitable guide dog available for that individual. Not all guide dog partnerships are successful, and the consequences of an unsuccessful partnership may result in reduced mobility and quality of life for the handler (owner), and are costly in time and resources for guide dog training establishments. This study examined 50 peoples' partnerships with one or more dogs (118 pairings) to ascertain the outcome of the relationship. Forty-three of the 118 dogs were returned to the guide dog training establishment before reaching retirement age, with the majority (n = 40) being categorized as having dog-related issues. Most (n = 26) of these dogs' issues were classified as being behavioral in character, including work-related and non-work-related behavior, and 14 were due to physical causes (mainly poor health). Three dogs were returned due to matters relating to the handlers' behavior. More second dogs were returned than the handlers' first or third dogs, and dogs that had been previously used as a guide could be rematched successfully. Defining matching success is not clear-cut. Not all dogs that were returned were considered by their handlers to have been mismatched, and not all dogs retained until retirement were thought to have been good matches, suggesting that some handlers were retaining what they considered to be a poorly matched dog. Almost all the handlers who regarded a dog as being mismatched conceded that some aspects of the match were good. For example, a dog deemed mismatched for poor working behavior may have shown good home and/or other social behaviors. The same principle was true for successful matches, where few handlers claimed to have had a perfect dog. It is hoped that these results may help the guide dog industry identify important aspects of the matching process, and/or be used to identify areas where a matching problem exists

Implementing social health insurance in Ireland: Report of a meeting and workshop held in Dublin, on December 6th 2010

We considered two basic questions, 'Is it possible to implement Social Health Insurance in Ireland?', and 'How can this be done?'. Can Social Health Insurance be implemented in Ireland? Our answer is a very definite yes. Furthermore, there would be many opportunities, while working towards this end, to improve the performance of our health care system. How can it be implemented? This process will need to be actively managed. There are many difficulties in the Irish health services, but also many opportunities. The greatest strengths are the talented, well-trained and very committed staff. Getting and keeping the support of these staff, for the necessary changes in service delivery, will be critical. Ireland has the capacity to make these changes, but without high quality management, a detailed focussed plan for change, and political support, little will happen. Each step in the change needs to be planned to maintain services, improve service delivery, improve service accountability, and improve service governance. Each sector of the service will need someone to lead the change, and mind that service during the change. Primary care remains under-developed. The HSE plan to develop primary care teams (PCT) has not succeeded. There are several established PCTs which work well. In other areas there are informal arrangements for collaboration, which work well. Overall, there are many useful lessons to learn from the experience so far. Future developments will need to place general practice at the centre of primary care. The mechanisms for doing this will vary from place to place, but need to be developed urgently. Acute hospitals face a crisis of governance. Maurice Hayes' (1) recent report on Tallaght hospital gives an idea of the scale of the changes needed. Tallaght is, we believe, not atypical, and is reputed to be by no means the worst governed hospital in the system. This, alone, should provide a pressing motive for change. Redesigning Irish hospitals to a new mission of supporting primary care, of supporting care in the community where possible can, and must, be done. Long-term care for older people is also a challenge. We advise moving to an integrated needs based system with smooth transitions between different degrees of support at home, and different degrees of support in specialized housing facilities including nursing homes. A similar model should apply to other forms of long-term care, for example for people with a substantial disability. Information systems and management processes both need a major overhaul. The health service remains strikingly under-managed, and fixing this will need a substantial culture change within the services. Wide use of standardized formal project management processes will be vital. There is a separate plan being developed to improve health service IT systems, and implementing this needs to be a high priority. We have not considered other key sectors, for example mental health, disability services, and social services. This does not mean that these are unimportant, merely that we had limited time, and a great deal to cover

The Impact of Self-reported Visual Disability on Quality of Life among Older Persons in a Rural Area of Northeast Thailand: A Follow-up Study

A population-based cross-sectional study was conducted to follow-up an earlier study which estimated the prevalence of self-reported visual disability and its impact on the quality of life (QOL) of older persons living in a rural area of Northeast Thailand based on a secondary analysis of data collected for another purpose. Self-reported difficulty with seeing was used to determine prevalence of visual disability. The WHOQOL-BREF and WHOQOL-OLD were used to assess the impact of visual disability on QOL. Fifty nine percent reported having difficulty seeing to the extent that it interfered with their daily life. Those who reported having difficulty with seeing were found to be older, disproportionately female, have lower perception of health, and to score lower on QOL than those who did not. The findings of this study differed from the earlier study. It is asserted that the findings from this latter study are likely to be more representative of the situation due to the use of a more systematic and targeted sampling procedure