A two year survey of ophthalmic traumas in the Maltese Islands, 1986-87

Many are the ophthalmic injuries seen daily at the ophthalmic department at St. Luke’s Hospital. The majority are of a minor nature and are treated on an out-patient basis. This is a retrospective survey of ophthalmic traumas of a serious nature occurring during the years 1986/1987. All the case required admission to hospital. The criteria used are various. Since this is a retrospective study no standardised format for data collection was used. There were 110 cases of which 94 were males and 16 females. The aim of the article is not to present the mode of treatment of these cases but to enlighten on the types of injures encountered and their causation.peer-reviewe

Papillitis as the prominent ocular sign in Acquired Immune Deficiency Syndrome (AIDS)

A 29-year old homosexual presented with clinical symptoms and an immunological picture of AIDS syndrome. Ocular involvement started in August 1986 with reduction of visual acuity in the right eye rapidly progressing to amaurosis. The most prominent ophthalmoscopical sign was of papillitis which had, in the beginning, the characteristics of an ischaemic optic neuropathy. Besides this, cotton-wool spots, retinal haemorrhages and limited areas of Cytomegalovirus (CMV) retinitis were found. Choroid was also involved with secondary CMV retinitis. On the other hand, sheathing of retinal vessels and Roth’s spots were absent. Although papilloedema, haemorrhages, cotton-wool exudates and CMV retinitis completely disappeared by October 1986, the general condition aggravated and the patient finally succumbed.peer-reviewe

Ocular manifestations in lepromatous and tuberculoid leprosy

Ocular manifestations of leprosy in 100 patients examined were reported on; -80% were suffering from the lepromatous type of the disease. The most frequent change was loss of eyebrows (40%) which was seen mainly in lepromatous patients. The sclera and cornea were rarely affected separately, but sclerokerato-iridocyclitis was found in 3%. On the other hand, the iris was involved rather more often -16% (atrophy of the iris -4, atrophy of the pupillary margin -3, miosis -1, posterior synechiae -6, keratic precipitates -1, and iris "pearls" -1). The iritis always had an insidious chronic evolution. The origin of the iritis is probably multifactorial: a) neuroparalytic due to involvement of the autonomic nerves supplying the iris muscles, primarily dilator; b) direct effect of Mycobacterium leprae on the iris tissue; and c) immune or auto-immune mechanisms. The posterior uvea was rarely affected (2%). No case of primary glaucoma was detected, but secondary glaucoma due to sclerokerato-iridocyclitis was found in 2 cases. Cataract seems to occur more frequently in leprosy patients (20%) than in the general population. The anterior segment was mostly affected (21%), and all these cases belonged to the lepromatous (16) or borderline lepromatous (5) type.peer-reviewe

An Efficient Implementation of a Subgraph Isomorphism Algorithm for GPUs.

The subgraph isomorphism problem is a computational task that applies to a wide range of today's applications, ranging from the understanding of biological networks to the analysis of social networks. Even though different implementations for CPUs have been proposed to improve the efficiency of such a graph search algorithm, they have shown to be bounded by the intrinsic sequential nature of the algorithm. More recently, graphics processing units (GPUs) have become widespread platforms that provide massive parallelism at low cost. Nevertheless, parallelizing any efficient and optimized sequential algorithm for subgraph isomorphism on many-core architectures is a very challenging task. This article presents , a parallel implementation of the subgraph isomorphism algorithm for GPUs. Different strategies are implemented in to deal with the space complexity of the graph searching algorithm, the potential workload imbalance, and the thread divergence involved by the non-homogeneity of actual graphs. The paper presents the results obtained on several graphs of different sizes and characteristics to understand the efficiency of the proposed approach

An entropy heuristic to optimize decision diagrams for index-driven search in biological graph databases

Graphs are a widely used structure for knowledge representation. Their uses range from biochemical to biomedical applications and are recently involved in multi-omics analyses. A key computational task regarding graphs is the search of specific topologies contained in them. The task is known to be NP-complete, thus indexing techniques are applied for dealing with its complexity. In particular, techniques exploiting paths extracted from graphs have shown good performances in terms of time requirements, but they still suffer because of the relatively large size of the produced index. We applied decision diagrams (DDs) as index data structure showing a good reduction in the indexing size with respect to other approaches. Nevertheless, the size of a DD is dependent on its variable order. Because the search of an optimal order is an NP-complete task, variable order heuristics on DDs are applied by exploiting domain-specific information. Here, we propose a heuristic based on the information content of the labeled paths. Tests on well-studied biological benchmarks, which are an essential part of multi-omics graphs, show that the resultant size correlates with the information measure related to the paths and that the chosen order allows to effectively reduce the index size

An entropy heuristic to optimize decision diagrams for index-driven search in biological graph databases

Graphs are a widely used structure for knowledge representation. Their uses range from biochemical to biomedical applications and are recently involved in multi-omics analyses. A key computational task regarding graphs is the search of specific topologies contained in them. The task is known to be NP-complete, thus indexing techniques are applied for dealing with its complexity. In particular, techniques exploiting paths extracted from graphs have shown good performances in terms of time requirements, but they still suffer because of the relatively large size of the produced index. We applied decision diagrams (DDs) as index data structure showing a good reduction in the indexing size with respect to other approaches. Nevertheless, the size of a DD is dependent on its variable order. Because the search of an optimal order is an NP-complete task, variable order heuristics on DDs are applied by exploiting domain-specific information. Here, we propose a heuristic based on the information content of the labeled paths. Tests on well-studied biological benchmarks, which are an essential part of multi-omics graphs, show that the resultant size correlates with the information measure related to the paths and that the chosen order allows to effectively reduce the index size

Multimodal Feature Integration in the Angular Gyrus during Episodic and Semantic Retrieval.

UNLABELLED: Much evidence from distinct lines of investigation indicates the involvement of angular gyrus (AnG) in the retrieval of both episodic and semantic information, but the region's precise function and whether that function differs across episodic and semantic retrieval have yet to be determined. We used univariate and multivariate fMRI analysis methods to examine the role of AnG in multimodal feature integration during episodic and semantic retrieval. Human participants completed episodic and semantic memory tasks involving unimodal (auditory or visual) and multimodal (audio-visual) stimuli. Univariate analyses revealed the recruitment of functionally distinct AnG subregions during the retrieval of episodic and semantic information. Consistent with a role in multimodal feature integration during episodic retrieval, significantly greater AnG activity was observed during retrieval of integrated multimodal episodic memories compared with unimodal episodic memories. Multivariate classification analyses revealed that individual multimodal episodic memories could be differentiated in AnG, with classification accuracy tracking the vividness of participants' reported recollections, whereas distinct unimodal memories were represented in sensory association areas only. In contrast to episodic retrieval, AnG was engaged to a statistically equivalent degree during retrieval of unimodal and multimodal semantic memories, suggesting a distinct role for AnG during semantic retrieval. Modality-specific sensory association areas exhibited corresponding activity during both episodic and semantic retrieval, which mirrored the functional specialization of these regions during perception. The results offer new insights into the integrative processes subserved by AnG and its contribution to our subjective experience of remembering. SIGNIFICANCE STATEMENT: Using univariate and multivariate fMRI analyses, we provide evidence that functionally distinct subregions of angular gyrus (AnG) contribute to the retrieval of episodic and semantic memories. Our multivariate pattern classifier could distinguish episodic memory representations in AnG according to whether they were multimodal (audio-visual) or unimodal (auditory or visual) in nature, whereas statistically equivalent AnG activity was observed during retrieval of unimodal and multimodal semantic memories. Classification accuracy during episodic retrieval scaled with the trial-by-trial vividness with which participants experienced their recollections. Therefore, the findings offer new insights into the integrative processes subserved by AnG and how its function may contribute to our subjective experience of remembering.This study was funded by a James S. McDonnell Foundation Scholar Award to JSS, and was carried out within the University of Cambridge Behavioural and Clinical Neuroscience Institute, funded by a joint award from the Medical Research Council and the Wellcome Trust. We would like to thank the staff of the MRC Cognition and Brain Sciences Unit MRI facility for scanning assistance.This is the final version of the article. It first appeared from the Society for Neuroscience via https://doi.org/10.1523/JNEUROSCI.4310-15.201

matching of prior textures by image compression for geological mapping and novelty detection

We describe an image-comparison technique of Heidemann and Ritter (2008a, b), which uses image compression, and is capable of: (i) detecting novel textures in a series of images, as well as of: (ii) alerting the user to the similarity of a new image to a previously observed texture. This image-comparison technique has been implemented and tested using our Astrobiology Phone-cam system, which employs Bluetooth communication to send images to a local laptop server in the field for the image-compression analysis. We tested the system in a field site displaying a heterogeneous suite of sandstones, limestones, mudstones and coal beds. Some of the rocks are partly covered with lichen. The image-matching procedure of this system performed very well with data obtained through our field test, grouping all images of yellow lichens together and grouping all images of a coal bed together, and giving 91% accuracy for similarity detection. Such similarity detection could be employed to make maps of different geological units. The novelty-detection performance of our system was also rather good (64% accuracy). Such novelty detection may become valuable in searching for new geological units, which could be of astrobiological interest. The current system is not directly intended for mapping and novelty detection of a second field site based on image- compression analysis of an image database from a first field site, although our current system could be further developed towards this end. Furthermore, the image-comparison technique is an unsupervised technique that is not capable of directly classifying an image as containing a particular geological feature; labelling of such geological features is done post facto by human geologists associated with this study, for the purpose of analysing the system's performance. By providing more advanced capabilities for similarity detection and novelty detection, this image-compression technique could be useful in giving more scientific autonomy to robotic planetary rovers, and in assisting human astronauts in their geological exploration and assessment

The Cyborg Astrobiologist: Testing a Novelty-Detection Algorithm on Two Mobile Exploration Systems at Rivas Vaciamadrid in Spain and at the Mars Desert Research Station in Utah

(ABRIDGED) In previous work, two platforms have been developed for testing computer-vision algorithms for robotic planetary exploration (McGuire et al. 2004b,2005; Bartolo et al. 2007). The wearable-computer platform has been tested at geological and astrobiological field sites in Spain (Rivas Vaciamadrid and Riba de Santiuste), and the phone-camera has been tested at a geological field site in Malta. In this work, we (i) apply a Hopfield neural-network algorithm for novelty detection based upon color, (ii) integrate a field-capable digital microscope on the wearable computer platform, (iii) test this novelty detection with the digital microscope at Rivas Vaciamadrid, (iv) develop a Bluetooth communication mode for the phone-camera platform, in order to allow access to a mobile processing computer at the field sites, and (v) test the novelty detection on the Bluetooth-enabled phone-camera connected to a netbook computer at the Mars Desert Research Station in Utah. This systems engineering and field testing have together allowed us to develop a real-time computer-vision system that is capable, for example, of identifying lichens as novel within a series of images acquired in semi-arid desert environments. We acquired sequences of images of geologic outcrops in Utah and Spain consisting of various rock types and colors to test this algorithm. The algorithm robustly recognized previously-observed units by their color, while requiring only a single image or a few images to learn colors as familiar, demonstrating its fast learning capability.Comment: 28 pages, 12 figures, accepted for publication in the International Journal of Astrobiolog