One-and-a-half syndrome : its presentation, causes and neuroanatomy

BACKGROUND: One-and-a-half syndrome involves a combination of an ipsilateral horizontal gaze palsy and an ipsilateral internuclear ophthalmoplegia. This condition is easily missed due to its presentation, but can be the first sign of serious disease. We aim to increase awareness of this syndrome’s presentation and give an insight into the intricate neuroanatomical connections that are affected in it.CASE PRESENTATION: We present a case of a 39-year-old previously healthy female who presented with a one-week history of diplopia and non-vertiginous dizziness. On examination, a left horizontal gaze palsy with deficits in left abduction and right adduction was noted, accompanied by left adduction weakness and right horizontal disconjugate jerk nystagmus in abduction. A diagnosis of OAHS was made, and she was admitted for further tests. An MRI of her brain revealed multiple hyperintensities throughout, along with an enhancing lesion in keeping with active disease. A diagnosis of Multiple Sclerosis was made and she was given a five-day course of methylprednisolone, with which her vision, and ultimately her gait, improved. She was discharged with outpatient follow-up, to further discuss treatment options for her new diagnosis.CONCLUSION: Diplopia and vertigo are symptoms that should prompt careful clinical examination with proper attention to ocular motility testing, and subsequent referral to neurology if required. Unnecessary delays in diagnosis and management could ultimately be detrimental to the patient, and being aware of uncommon presentations would go a long way in enhancing patient safety.peer-reviewe

Evidence for Melt Leakage from the Hawaiian Plume above the Mantle Transition Zone

Dehydration reactions at the top of the mantle transition zone (MTZ) can stabilize partial melt in a seismic low-velocity layer (LVL), but the seismic effects of temperature, melt and volatile content are difficult to distinguish. We invert P-to-S receiver function phases converted at the top and bottom of a LVL above the MTZ beneath Hawaii. To separate the thermal and melting related seismic anomalies, we carry out over 10 million rock physics inversions. These inversions account for variations arising from the Clapeyron slope of phase transition, bulk solid composition, dihedral angle, and mantle potential temperature. We use two independent seismic constraints to evaluate the temperature and shear wave speed within the LVL. The thermal anomalies reveal the presence of a hot and seismically slow plume stem surrounded by a “halo” of cold and fast mantle material. In contrast to this temperature distribution, the plume stem contains less than 0.5 vol% melt, while the surrounding LVL—within the coverage area—contains up to 1.7 vol% melt, indicating possible lateral transport of the melt. When compared to the melting temperatures of mantle rocks, the temperature within the LVL, calculated from seismic observations of MTZ thickness, suggests that the observed small degrees of melting are sustained by the presence of volatiles such as CO2 and H2O. We estimate the Hawaiian plume loses up to 1.9 Mt/yr H2O and 10.7 Mt/yr CO2 to the LVL, providing a crucial missing flux for global volatile cycles

Raman spectroscopy of gallium ion irradiated graphene

The successful integration of graphene in future technologies, such as filtration and nanoelectronics, depends on the ability to introduce controlled nanostructured defects in graphene. In this work, Raman spectroscopy is used to investigate the induction of disorder in graphene via gallium ion beam bombardment. Two configurations of CVD-grown graphene samples are used: (i) graphene supported on a Si/SiO2 substrate, and (ii) graphene suspended on porous TEM grids. It is observed that the supported graphene experiences more damage in response to lower beam doses than suspended graphene. This phenomenon is attributed to the behaviour of the energetic ions impinging the sample. In suspended graphene, the ions pass through the graphene membrane once and disperse to the atmosphere, while in supported graphene, the ions embed themselves in the substrate causing swelling and backscattering events, hence increasing the induced disorder. In supported graphene, the ratio between the Gaussian D and G peaks attributed to amorphous carbon, and the Lorentzian D and G peaks attributed to graphene, (IDG/IDL) and (IGG/IGL), are suggested to be used to quantify the degree of amorphization. The results are relevant to the development of nanostructured graphene-based filtration or desalination membranes, as well as for graphene-based nanoelectronics.JRC.F.2-Consumer Products Safet

Is it giant cell arteritis? : a retrospective audit on temporal artery biopsy for giant cell arteritis

Background: Giant cell arteritis (GCA) is the commonest of the vasculitides and should form part of the differential diagnosis of a new-onset headache in patients over 50 years with elevated inflammatory markers. Temporal artery biopsy (TAB) is the gold standard for its diagnoses. Aim: The aim of this audit was to determine whether patients referred for a TAB between 2010 and 2015 at Mater Dei Hospital qualified for a diagnosis of GCA and the significance of the TAB result in affecting management of GCA by correlating the clinical profile and biochemical criteria according to the guidelines based on the American College of Rheumatology (ACR) criteria. Results: The percentage of positive TABs in our cohort of 170 patients was 23%. The ESR (sensitivity - 100%) was shown to be a significant factor associated with a positive TAB when compared to CRP (sensitivity 90%). 79.5% of positive TAB results were patients aged between 70-89 years of age, proving age is also a significant factor. New onset headache was the most common complaint (66%). Only 45.9% of patients were started on steroids prior to TAB despite the clinical suspicion of GCA. This increased to 54.1% of patients on steroids after TAB was performed, pending a histology result. Conclusion:Our findings, which are similar to comparing studies, question the practicality of TAB in the clinical diagnosis of GCA. Clinical symptoms, raised ESR and increasing age proved to be significant factors contributing to the clinical diagnosis and management of GCA. Non-invasive ultrasonography can further confirm the diagnosis and is to replace TAB in the near future.peer-reviewe

Post-earthquake damage classification and assessment: case study of the residential buildings after the Mw = 5 earthquake in Mila city, Northeast Algeria on August 7, 2020

On August 7th, 2020, a magnitude Mw = 5.0 earthquake shook 5 km north of Mila city center, northeast of Algeria, causing substantial damage directly to structures, and indirectly from induced impacts of landslides and rock falls, ultimately disrupt to everyday civilian life. Given the recent significant seismic occurrences in the region, a detailed and comprehensive examination and assessment of post-earthquake damage is critical to Algeria. This is primarily because masonry, concrete, and colonial-era structures are sensitive to horizontal motions caused by seismic waves, and because masonry and concrete structures constitute a substantial portion of today’s Algeria's build environment. We present a post-earthquake investigation of the Mila earthquake, starting from the earthquake source, and a catalogue of buildings type, damage categorization, and failure patterns of residential structures in Mila's historic old town, where colonial-era brick buildings prevail. We find that structures that represent notable architectural achievements were severely damaged as a result of the earthquake. Data acquired during the immediate post-earthquake analysis was also evaluated and discussed. The graphical representations of the damages are detailed and complemented by photos. This seismic event has shown the fragility of Algeria's building stock, which must be addressed properly in future years. This study reports on an overall estimate of residential buildings in Mila's lower city, as well as an evaluation of the seismic vulnerability of three neighborhood towns (El-Kherba, Grareme-Gouga, and Azzeba). A generic database for graphical surveys and geometric research was developed and implemented making it possible to evaluate the shear strength on-site. The broad observations, collated data, and consequences were then loaded into the 3Muri structural verification program. Nonlinear static analysis was conducted to analyze probable failure paths and compare the real damage to the software results.publishe

Analysis of online news coverage on earthquakes through text mining

News agencies work around the clock to report critical news such as earthquakes. We investigate the relationship between online news articles and seismic events that happen around the world in real time. We utilize computer text mining tools to automatically harvest, identify, cluster and extract information from earthquake-related reports, and carry out cross-validation on the mined information. Earthquake parameters retrieved from the United States Geological Survey (USGS) Application Programming Interface (API) are organized into earthquake events, with each event consisting of daily earthquake readings taking place in a particular geographical location. The results are then visualized on a user-friendly dashboard. 268,182 news reports published by 23 news agencies from different parts of the world and 14,717 earthquakes of magnitude ranging from 4 to 8.2 listed in the bulletin were processed during a 1-year study between 2018 and 2019. 1.25% of the analyzed articles had the word “quake” and 0.4% were clustered and then mapped to an earthquake event. The use of multilingual news sources from 16 countries (6 languages) gives the advantage of reducing potential news bias originating from English-written reports only. The mapping of articles with an earthquake catalog helps verify earthquake reports and determine relationships. We find that the distribution of the reported seismicity is from earthquakes that occur on or very close to land. We propose a general relationship between the number of news agencies, the earthquake magnitude and the anticipated number of published articles. News reports tend to mention higher earthquake magnitudes than those in the USGS earthquake catalog, and the reports on earthquakes can last from a few days to a couple of weeks following the earthquake.peer-reviewe

Neogeography and seismic risk perception : a comparison between two case studies : Calabria, Southern Italy and Malta

Geography of perception aims at clarifying human behaviour by studying the concepts and images of the real world that a person elaborates on by considering the psychological and social aspects of man’s behaviour within an environment. In this context, a questionnaire was given to primary and middle school pupils in an area of Calabria (Southern Italy), which has recently been affected by an on-going seismic sequence widely felt by the local population. The same questionnaire was given to students in Malta (Central Mediterranean), an area considered to have a low-to-moderate seismic hazard, and where earthquake awareness is not culturally strong. In this way, the knowledge effectively possessed by the students (relating to age, experience and area of origin) are analysed; their analogous and differing perceptions on earthquakes in different areas are highlighted. The data collected can be used to project and create new informative tools through which students will become “geographic information volunteers” studying natural risks such as earthquakes, and augmenting the territory’s level of resilience.peer-reviewe

Georisks in the Mediterranean and their mitigation

An international scientific conference organised by the Seismic Monitoring and Research Unit, Department of Geoscience, Faculty of Science, Department of Civil and Structural Engineering and Department of Construction and Property Management, Faculty of the Built Environment, University of Malta.Part of the SIMIT project: Integrated civil protection system for the Italo-Maltese cross-border area. Italia-Malta Programme – Cohesion Policy 2007-2013This conference is one of the activities organised within the SIMIT strategic project (Integrated Cross-Border Italo-Maltese System of Civil Protection), Italia-Malta Operational Programme 2007 – 2013. SIMIT aims to establish a system of collaboration in Civil Protection procedures and data management between Sicilian and Maltese partners, so as to guarantee the safety and protection of the citizens and infrastructure of the cross-border area. It is led by the Department of Civil Protection of the Sicilian region, and has as other partners the Department of Civil Protection of Malta and the Universities of Palermo, Catania and Malta. SIMIT was launched in March 2013, and will come to a close in October 2015. Ever since the initial formulation of the project, it has been recognised that a state of national preparedness and correct strategies in the face of natural hazards cannot be truly effective without a sound scientific knowledge of the hazards and related risks. The University of Malta, together with colleagues from other Universities in the project, has been contributing mostly to the gathering and application of scientific knowledge, both in earthquake hazard as well as in building vulnerability. The issue of seismic hazard in the cross-border region has been identified as deserving foremost importance. South-East Sicily in particular has suffered on more than one occasion the effects of large devastating earthquakes. Malta, although fortunately more removed from the sources of such large earthquakes, has not been completely spared of their damaging effects. The drastic increase in the building density over recent decades has raised the level of awareness and concern of citizens and authorities about our vulnerability. These considerations have spurred scientists from the cross-border region to work together towards a deeper understanding of the underlying causes and nature of seismic and associated hazards, such as landslide and tsunami. The SIMIT project has provided us with the means of improving earthquake surveillance and analysis in the Sicily Channel and further afield in the Mediterranean, as well as with facilities to study the behaviour of our rocks and buildings during earthquake shaking. The role of the civil engineering community in this endeavour cannot be overstated, and this is reflected in the incorporation, from the beginning, of the civil engineering component in the SIMIT project. Constructing safer buildings is now accepted to be the major option towards human loss mitigation during strong earthquakes, and this project has provided us with a welcome opportunity for interaction between the two disciplines. Finally the role of the Civil Protection authorities must occupy a central position, as we recognize the importance of their prevention, coordination and intervention efforts, aided by the input of the scientific community. This conference brings together a diversity of geoscientists and engineers whose collaboration is the only way forward to tackling issues and strategies for risk mitigation. Moreover we welcome the contribution of participants from farther afield than the Central Mediterranean, so that their varied experience may enhance our efforts. We are proud to host the conference in the historic city of Valletta, in the heart of the Mediterranean, which also serves as a constant reminder of the responsibility of all regions to protect and conserve our collective heritage.peer-reviewe