Solving large 0–1 multidimensional knapsack problems by a new simplified binary artificial fish swarm algorithm

The artificial fish swarm algorithm has recently been emerged in continuous global optimization. It uses points of a population in space to identify the position of fish in the school. Many real-world optimization problems are described by 0-1 multidimensional knapsack problems that are NP-hard. In the last decades several exact as well as heuristic methods have been proposed for solving these problems. In this paper, a new simpli ed binary version of the artificial fish swarm algorithm is presented, where a point/ fish is represented by a binary string of 0/1 bits. Trial points are created by using crossover and mutation in the different fi sh behavior that are randomly selected by using two user de ned probability values. In order to make the points feasible the presented algorithm uses a random heuristic drop item procedure followed by an add item procedure aiming to increase the profit throughout the adding of more items in the knapsack. A cyclic reinitialization of 50% of the population, and a simple local search that allows the progress of a small percentage of points towards optimality and after that refines the best point in the population greatly improve the quality of the solutions. The presented method is tested on a set of benchmark instances and a comparison with other methods available in literature is shown. The comparison shows that the proposed method can be an alternative method for solving these problems.The authors wish to thank three anonymous referees for their comments and valuable suggestions to improve the paper. The first author acknowledges Ciˆencia 2007 of FCT (Foundation for Science and Technology) Portugal for the fellowship grant C2007-UMINHO-ALGORITMI-04. Financial support from FEDER COMPETE (Operational Programme Thematic Factors of Competitiveness) and FCT under project FCOMP-01-0124-FEDER-022674 is also acknowledged

Neuroimaging correlates of false memory in 'Alzheimer's disease: A preliminary systematic review

Alzheimer's disease (AD) is characterised by episodic memory impairment, but people also experience memory distortions, including false memories, which can impact on safety and reduce functioning. Understanding the neural networks that underpin false memories could help to predict the need for intervention and guide development of cognitive strategies to reduce memory errors. However, there is a relative absence of research into how the neuropathology of AD contributes to false memory generation. This paper systematically reviews the methodology and outcomes of studies investigating the neuroimaging correlates of false memory in AD. Four studies using structural imaging and three studies using functional imaging were identified. Studies were heterogenous in methodology and received mostly ‘weak’ quality assessment ratings. Combined, and consistent with neuroimaging findings in non-AD populations, results from identified studies provide preliminary support for the hypothesis that medial temporal lobe and prefrontal cortex dysfunction may lead to generation of false memories in AD. However, the small number of studies and significant heterogeneity within them means further study is necessary to assess replicability of results

Falls in the elderly: assessment of prevalence and risk factors

Background: Falls in elderly people can lead to serious health problems. There is limited knowledge about the prevalence of falls, risk factors and causes of falls in the United Arab Emirates. Objective: To assess the prevalence of falls among older adults aged 60 years and above and to determine the risk factors associated with falls. Methods: This cross-sectional study was conducted using an anonymous, 20-item questionnaire which was developed in English and Arabic to be delivered as a semi-structured interview. The pre-piloted questionnaire was distributed to 510 families with at least one elderly person. The study was conducted in Sharjah and Dubai, United Arab Emirates, from September to November 2017. Results: Participants were Arabs (368; 99.5%), living with family (339; 91.6%), females (256; 69.2%), married (240; 64.9%), holders of a university Bachelor’s degree (110; 29.7%), and unemployed (154; 41.6%). Almost half of the participants (188; 50.8%) had a fall in the past two years, and three quarters (141; 75%) of those claimed that their illness was the reason for their fall. The results indicate that female and 70 years and above old participants are more likely to experience falls than males and younger counterparts respectively. A larger proportion of elderly participants not taking medications did not experience falls, while those on 1-4 medications fallers were less than non-fallers. However as the number of medications increased to 5-8 and more than 8 the number of those experiencing falls was significantly higher than non-fallers. Conclusions: Falls are prevalent among the elderly population studied and efforts should be made to decrease the incidence of falls, identify those at risk and increase awareness about falls and their health consequences among the elderly and the general public

Otite externa necrotizante com paralisia facial periférica bilateral: relato de caso e revisão da literatura Necrotizing external otitis with periferic bilateral facial palsy: case report and literature review

A otite externa necrotizante (OEN), conhecida no passado como otite externa maligna, é uma infecção potencialmente letal que começa usualmente no conduto auditivo externo e se estende à base do crânio ocorrendo, principalmente, em pacientes diabéticos idosos e que a despeito de antibioticoterapia prolongada está associada à morbidade elevada e mortalidade significante. Os autores apresentam o caso de um paciente adulto, diabético, com OEN e paralisia facial periférica bilateral que evoluiu com cura da infecção, porém sem melhora da paralisia.<br>Necrotizing external otitis (NEO), known in the past as malignant external otitis, is a potencial letal infection which begins usually in the external ear canal and spreads to the base of the skull. It occurs mainly in diabetic elderly patients who despite prolonged antibioticotherapy is associated to high morbidity and significant mortality. The authors present a case of an adult diabetic patient who developed NOE associated with bilateral periferic facial palsy evoluting with cure of the infection but without facial improvement