Article Operational Results with Fast Automatic Beam-Based LHC Collimator Alignment Gianluca Valentino, Ralph W. Assmann, Roderik Bruce, Stefano Redaelli, Belen Salvachua, Nicholas Sammut, Daniel Wollmann Pages: 3 - 14 Read Abstract | View full article |
PDF Abstract: The CERN Large Hadron Collider (LHC) is the largest and highest-energy particle accelerator ever built. It is designed to collide particles at a centre-of-mass energy of 14 TeV to explore the fundamental forces and constituents of matter. Due to the potentially destructive high-energy particle beams, with a total design energy of 362 MJ, the collider is equipped with a series of machine protection systems. The beam cleaning or collimation system is designed to passively intercept and absorb particles at large amplitudes. The cleaning eciency depends heavily on the accurate positioning of the jaws with respect to the beam trajectory. Beam-based collimator alignment is currently the only feasible technique that can be used to determine the beam centre and beam size at the collimator locations. If the alignment is performed without any automation, it can require up to 30 hours to complete for all collimators. This reduces the beam time available for physics experiments. This article provides a brief recap of the algorithms and software developed to automate and speed up the alignment procedure, and presents the operational results achieved with fast automatic beam-based alignment in the 2011- 2013 LHC runs.
Doi: http://dx.medra.org/10.7423/XJENZA.2013.2.01
Article Serotonin, how to find it... Francesco Crespi Pages: 15 - 23 Read Abstract | View full article |
PDF Abstract: Serotonin or 5-hydroxytryptamine (5- HT) is a monoamine neurotransmitter. Biochemically derived from tryptophan, serotonin is primarily found in the gastrointestinal tract, platelets, and in the central nervous system (CNS) of animals, including humans. Discovered and crystallized over sixty years ago, serotonin operates as a short-range neurotransmitter as well as a long-range signalling modulator, with multiple effects on whole organism functions via plasma, platelet and neuroendocrine, gut, adrenal and other peripheral systems across many species. All of the important functions of serotonin in the brain and body were identi ed over the ensuing years by neurochemical, physiological and pharmacological investigations. Mainly, all these investigations have been performed via invasive methodologies, particularly in the CNS studies. Here we present a rapid overview of such methodological approaches focussing on voltammetry, one of the most recent technical approaches for serotonin analysis in vivo, in situ and in real time. Furthermore, we introduce a late technical evolution in the attempt to obtain in vivo non invasive measurement of brain serotonin.
Doi: http://dx.medra.org/10.7423/XJENZA.2013.2.02
Article The Pygmalion-Galatea myth in relation to simulation scenarios in Star Trek Victor Grech Pages: 24 - 29 Read Abstract | View full article |
PDF Abstract: Star Trek has existed since 1966, with a total of 738 hours of viewing time. Like most science ction, the series frequently alludes to religion or myth but censors such references for the modern world-view by sanitising them with scienti c or scienti c-sounding explanation. This paper illustrates the depiction of the Galatea-Pygmalion myth in the franchise and relates these to simulation scenarios.
Doi: http://dx.medra.org/10.7423/XJENZA.2013.2.03
Article Stroke patients' interpretation of symptoms and presentation to hos- pital Gabrielle Scicluna, Maria Mallia, Mark Gruppetta, Francesca Theuma, Simon Aquilina, Josanne Aquilina Pages: 30 - 33 Read Abstract | View full article |
PDF Abstract: The aim of this study was to elucidate patient interpretation of stroke symptoms and to investigate factors which in uence timely presentation to hospital. Methods All patients admitted to Mater Dei Hospital with a diagnosis of cerebrovascular accident (CVA) or transient ischaemic attack (TIA) between July and September 2011 were recruited prospectively. Data was collected by patient interview and with reference to medical notes in order to determine patient risk factors for stroke, knowledge on stroke, interpretation of stroke symptoms and time interval to presentation to hospital. Results The cohort studied (N = 54) had an average age of 67.9years (SD = 10:407). The risk factors for cerebrovascular disease most frequently found in this group were hypertension (56%), hypercholesterolaemia (56%), family history of stroke (41%) and smoking (39%). Participants interpreted their symptoms as stroke in 33% of cases (n = 18), whereas 48% reported that they did not know or suspect any particular cause at the time. The perceived severity of events at symptom onset was reported as `high' by 41% and `low' by 57%. Only 31% of participants (n = 17) recognised the brain as the organ primarily affected in stroke. Forty ve percent of patients sought medical advice within one hour. Fifty-six percent (n = 30) rst resorted to their family doctor, whilst 28% (n = 15) phoned the emergency services. Family doctor as rst contact was associated with delayed presentation (p = 0.007); conversely, phoning emergency services was associated with earlier presentation to A&E. Conclusion The results of this study highlight limited knowledge about stroke in the population involved. It also serves to clarify factors contributing to high rates of late presentation. These ndings show the need for an improvement in public awareness in terms of education on stroke and the importance of early presentation to hospital.
Doi: http://dx.medra.org/10.7423/XJENZA.2013.2.04
Article Pollen Characterisation of Maltese Honey Claudette Gambin, Edwin Lanfranco, David Mifsud Pages: 34 - 47 Read Abstract | View full article |
PDF Abstract: In 2004 and 2005, pollen characterisation of 35 samples of honey collected from the islands of Malta and Gozo, was carried out with the aim to identify the botanical origin of honey produced on these islands. Pollen was extracted from the honey samples via centrifugation and identi ed to pollen type, generic level and where possible, speci c level via microscopic analysis. This was done by comparison with available literature and with the aid of prepared reference slides of pollen collected from the plant species commonly present in the Maltese islands. A total of 61 pollen types were identi ed from 33 families. The best represented families were the Asteraceae, Brassicaceae, Fabaceae and Apiaceae. Thyme (Thymbra capitata (L.) CAV.) pollen was found to be predominant in ten samples, with a percentage frequency that ranged from 10% to 67%. Hedysarum coronarium L. was found to be predominant in ve honey samples with percentage frequencies from 48% to 78% while Lotus spp. pollen was found to be predominant in one honey sample with a percentage frequency of 57%. The remaining 14 honey samples possessed pollen spectra which were characterized by a few frequent pollen types that possessed similar percentage frequencies and were thus considered to be multi oral. This is the rst work of pollen characterisation of Maltese honey.
Doi: http://dx.medra.org/10.7423/XJENZA.2013.2.05
Article The role of Public Transport in addressing Sustainable Mobility for the Elderly Population in Malta none Pages: 48 - 55 Read Abstract | View full article |
PDF Abstract: Over the past few years, several countries have continued experiencing a growth in their elderly population. Similarly, a number of towns and villages in Malta registered a high elderly population in the last census (NSO, 2012). The elderly people are one of the dominant `transport disadvantaged' groups in the community. This research aims to analyse whether the current public transport system in Malta is providing effective and efficient mobility for elderly in the town of Luqa. In order to analyse this, the study analysed spatial accessibility, sought to identify barriers encountered by the elderly when using public transport and determine temporal accessibility to medical care. Data was collected using telephone surveys, travel time and bus frequency surveys. Statistical analysis was carried out using IBM SPSS 20 and Geographic Information Systems. The study showed that proximity to bus stops in Luqa does not affect public transport use amongst the elderly. The main barriers that elderly encounter when using public transport are mainly related to long waiting times, lack of comfort on bus stops and inaccessible travel information. Finally, temporal accessibility from Luqa to the State's general hospital, Mater Dei, still requires improvements as it does not meet the desired time budgets of elderly people. By identifying the main concerns this study seeks to encourage policy makers and planners to target future development in public transport taking into consideration the requirements of the growing elderly population.
Doi: http://dx.medra.org/10.7423/XJENZA.2013.2.06
Article A Study of Nano-Particle Based Silane Consolidants for Globigerina Limestone Sophie M Briffa, Daniel Vella, Maria J Mosquera Pages: 56 - 65 Read Abstract | View full article |
PDF Abstract: This STEPS funded study focuses on the application of hybrid and nanoparticle loaded hybrid silane consolidants for the treatment of 'Franka' Globigerina Limestone. Consolidants act by gluing deteriorated stone material to underlying healthy stone (Dukes, 1972; Gutt, 1973; Garrod, 2001). The consolidants evaluated were a laboratory prepared hybrid silane based on a mixture of tetraethylorthosilicate (TEOS) and 3-(glycidoxypropyl) trimethoxysilane (GPTMS), the same hybrid loaded with silica nanoparticles and loaded with GPTMS-modi ed silica nanoparticles. In addition, a consolidant based on the hydrolysis product of TEOS was also tested. Prepared consolidants were applied to test blocks by complete immersion. Untreated stone block were used as benchmarks. Following application, half of the treated samples were subjected to accelerated weathering. All limestone blocks were then characterised by colorimetry and optical and electron microscopy. The pore size distribution was assessed by Mercury Intrusion Porosimetry. A water absorption by capillarity technique was also carried out to assess any changes in water uptake rate. The mechanical properties were assessed by resistance to sodium sulfate crystallisation. Microscopy observations showed that penetration into the stone occurred to different extents depending on the consolidant. The hybrid consolidant led to yellowing of the limestone but the addition of nanoparticles to the hybrid (modi ed or not) appeared to help restore the original colour of the stone. The porosity of the limestone was only marginally affected by the different treatments but the somewhat hydrophobic nature of the consolidants led to a disruption in the capillary ow of water into the limestone.
Doi: http://dx.medra.org/10.7423/XJENZA.2013.2.07
Article Optical Glauber Modeling in High-Energy Nuclear Collisions Jurgen Mifsud, Thorsten Kollegger Pages: 66 - 72 Read Abstract | View full article |
PDF Abstract: The Optical Glauber Model is used in this study in order to understand the initial conditions in heavy-ion collisions and at the end understand the relationship between the particles produced after the collision. In the rst part of this study, the initial geometrical features of the collision as a function of the impact parameter, such as the number of participating nucleons and the number of collisions between nucleons are obtained. Then, after obtaining numerical values for the number of participating nucleons, the study was focused on two distinct particles being produced after the collision and the relationship between them is also determined from the correlation as a function of the impact parameter.
Doi: http://dx.medra.org/10.7423/XJENZA.2013.2.08
Article Nicotine Addiction: A Review Jacob Vella, Giuseppe Di Giovanni Pages: 73 - 85 Read Abstract | View full article |
PDF Abstract: Nicotine, the major psychoactive compound in tobacco, acts as a potent addictive drug in humans. The addictive nature of nicotine leads to more than 6 million deaths a year. Evidence indicates that nicotine and other drugs of abuse act on central dopaminergic pathways and modulate their neurophysiological mechanisms. Nicotine stimulates dopaminergic pathways and the prefrontal cortex (PFC), inducing enhanced reward perception and increased cognitive function, respectively. These ndings are consistent with the fact that nicotine binds to different subtypes of nicotinic acetylcholine receptors present on the neurons found in the PFC and ventral tegmental area of the midbrain. The latter, being the area most involved in addictive behaviour, projects to the limbic system, particularly the nucleus accumbens, and receives afferents from the prefrontal cortex and brainstem. Although dopaminergic pathways and nicotinic acetylcholine receptors are the protagonists of nicotine addiction, several minor pathways and their constituent receptors have been indicated as being either directly or indirectly a ected by nicotine. These include serotonergic pathways and central cannabinoid receptors. Despite the scarcity of approved drugs and partial ecacy of approved treatment, insight into nicotine neurophysiological modulation has led to a better appreciation of nicotine-seeking behaviour and subsequent improved design of pharmacological and behavioural approaches to smoking cessation. Tobacco is the single most preventable cause of death in the world today. Better understanding of the neurobiological mechanisms underlying nicotine addiction will ultimately lead to more e ective treatments of both nicotine dependence and nicotine rewarding effects.
Doi: http://dx.medra.org/10.7423/XJENZA.2013.2.09
Article Lessons from an unplanned scientific and academic life Francis Vella Pages: 86 - 97 View full article |
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Article Webcast courses in Medical Genetics and Next Generation Sequencing Isabella Borg Pages: 98 - 100 View full article |
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Article INTERDISCIPLINARY CHEMICAL APPROACHES FOR NEUROPATHOLOGY CM1103 Giuseppe Di Giovanni Pages: 101 - 119 View full article |
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