22,524 research outputs found
Checking chess checks with chunks: A model of simple check detection
The procedure by which humans identify checks in check positions is not well understood. We report here our experience in modelling this process with CHREST, a general-purpose cognitive model that has previously successfully captured a variety of attention- and perception-related phenomena. We have attempted to reproduce the results of an experiment investigating the ability of humans to determine checks in simple chess positions. We propose a specific model of how humans perform this experiment, and show that, given certain reasonable assumptions, CHREST can follow this model to create a good reproduction of the data
An investigation into the effect of ageing on expert memory with CHREST
CHREST is a cognitive architecture that models human perception, learning, memory, and problem solving, and which has successfully simulated numerous human experimental data on chess. In this paper, we describe an investigation into the effects of ageing on expert memory using CHREST. The results of the simulations are related to the literature on ageing. The study illustrates how Computational Intelligence can be used to understand complex phenomena that are affected by multiple variables dynamically evolving as a function of time and that have direct practical implications for human societies
Modelling the relationship between visual short-term memory capacity and recall ability
Previous cognitive modelling work has suggested that the decline of short-term memory (STM) capacity is the dominant factor of age-related decline on recall ability. We report the results of a set of experiments investigating in further detail the effect of varying short-term memory capacity on the recall of chess positions using the CHREST cognitive architecture, and demonstrate a good qualitative match for human data. We then use these results to suggest a potential functional reason for the size of STM capacity in humans and go on to explore the relationships between STM capacity, ageing, knowledge, presentation time, and recall ability
“A respite thing” – A qualitative study of a creative arts leisure programme for family caregivers of people with dementia
This study explored the meanings of participating in a five-week creative arts leisure programme designed for family caregivers of people with dementia, using interpretative phenomenological analysis. Eight carers attended and four who met the eligibility criteria agreed to be interviewed. Participants experienced the arts group as providing a sense of freedom and respite, strengthening identity through promoting achievement, offering social support through a collective focus on art- and craft-making, and increasing resilience for coping with caring. Some found the five-week programme too short. Benefits were linked to the security of knowing that loved ones with dementia were close by, being well cared for. Further research is needed into the longer-term benefits of creative arts groups for promoting carer well-being
An efficient semiparametric maxima estimator of the extremal index
The extremal index , a measure of the degree of local dependence in
the extremes of a stationary process, plays an important role in extreme value
analyses. We estimate semiparametrically, using the relationship
between the distribution of block maxima and the marginal distribution of a
process to define a semiparametric model. We show that these semiparametric
estimators are simpler and substantially more efficient than their parametric
counterparts. We seek to improve efficiency further using maxima over sliding
blocks. A simulation study shows that the semiparametric estimators are
competitive with the leading estimators. An application to sea-surge heights
combines inferences about with a standard extreme value analysis of
block maxima to estimate marginal quantiles.Comment: 17 pages, 7 figures. Minor edits made to version 1 prior to journal
publication. The final publication is available at Springer via
http://dx.doi.org/10.1007/s10687-015-0221-
Antimicrobial resistance and antimicrobial use animal monitoring policies in Europe: Where are we?
The World Health Organization has recognized antimicrobial resistance as one of the top three threats to human health. Any use of antibiotics in animals will ultimately affect humans and vice versa. Appropriate monitoring of antimicrobial use and resistance has been repeatedly emphasized along with the need for global policies. Under the auspices of the European Union research project, EFFORT, we mapped antimicrobial use and resistance monitoring programs in ten European countries. We then compared international and European guidelines and policies. In resistance monitoring, we did not find important differences between countries. Current resistance monitoring systems are focused on food animal species (using fecal samples). They ignore companion animals. The scenario is different for monitoring antibiotics use. Recently, countries have tried to harmonize methodologies, but reporting of antimicrobial use remains voluntary. We therefore identified a need for stronger policies
Comparison of surgical indications and short- and long-term complications in 56 cats undergoing perineal, transpelvic or prepubic urethrostomy
Objectives
The aim of this study was to compare indications, complications and mortality rates for perineal urethrostomy (PU), transpelvic urethrostomy (TPU) and prepubic urethrostomy (PPU).
Methods
A retrospective review of, and follow-up owner questionnaire for, cats undergoing urethrostomy between 2008 and 2018, at a single referral hospital, were performed.
Results
Fifty-six cats underwent urethrostomy (PU, n = 37; TPU, n = 8; PPU, n = 11). The presenting problem was significantly associated with urethrostomy technique (P <0.001). For PU cats, feline idiopathic cystitis (FIC; n = 21 [56.7%]) was the most common problem, whereas for PPU cats, trauma (n = 9 [81.8%]) was most common (P <0.001). Urethrostomy technique was associated with imaging diagnosis (P <0.001) of the urethral lesion. Most PU cats had no diagnostic imaging lesion (n = 15 [40.5%]) or obstructive calculi or clots (n = 10 [27.0%]), and all PPU cats had urethral rupture. Ten (90.9%) PPU cats had a pelvic lesion, while 21 (56.7%) PU cats had a penile lesion. TPU cats had a range of presenting problems and imaging diagnoses. Short- and long-term complications were reported in 33/55 (60.0%) and 11/30 (36.7%) cats, respectively. The number of cats with long-term complications was greater among PPU cats (P = 0.02). Short-term dermatitis (P = 0.019) and long-term incontinence (P = 0.01) were associated with PPU. Short-term mortality was 5.6% and long-term mortality was 13.3%; both were independent of urethrostomy technique. Quality of life post-urethrostomy, across all techniques, was graded as good by 93% of owners.
Conclusions and relevance
In this study, PU was the most common feline urethrostomy technique indicated for FIC. Short-term urethrostomy complications are common, irrespective of urethrostomy technique. Long-term complications are less frequent but more common with PPU
A predicted astrometric microlensing event by a nearby white dwarf
We used the Tycho-Gaia Astrometric Solution catalogue, part of the Gaia Data
Release 1, to search for candidate astrometric microlensing events expected to
occur within the remaining lifetime of the Gaia satellite. Our search yielded
one promising candidate. We predict that the nearby DQ type white dwarf LAWD 37
(WD 1142-645) will lens a background star and will reach closest approach on
November 11th 2019 ( 4 days) with impact parameter mas. This
will produce an apparent maximum deviation of the source position of
mas. In the most propitious circumstance, Gaia will be able to
determine the mass of LAWD 37 to . This mass determination will
provide an independent check on atmospheric models of white dwarfs with helium
rich atmospheres, as well as tests of white dwarf mass radius relationships and
evolutionary theory
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