Interview with the Coordinator Prof. Giuseppe Di Giovanni, University of Malta, Department of Physiology and Biochemistry

Interview with the Coordinator of the Malta Neuroscience Network Programme, Prof. Giuseppe Di Giovanni regarding the Malta Neuroscience Net- work. "With the creation of the Malta Neuroscience Network, we will be keeping up with the most important developments with regard to brain research world- wide: multi-disciplinary collaboration. Understanding the way the brain works, and above all brain diseases is extremely complicated, and requires the involvement of researchers coming from a number of diff erent scientifi c disciplines and clinical areas collaborating in new ways."peer-reviewe

Second Neuroscience Day at the University of Malta

The second Neuroscience Seminar Day @ the University of Malta was held on the 5th and 6th of July 2011 at the Faculty of Medicine and Surgery. The principal aim of this day was to create a forum in which Maltese and Italian neuroscientists could meet. Academics involved in this field benefit substantially by meeting and interacting with international colleagues, and thereby developing new collaborations. This view is held not only by myself, but also by Professor Richard Muscat, ProRector for Research and Innovation, who is always highly supportive of the development of the field of neuroscience and of research in general in Malta. My second objective in organising these neuroscience seminars is to offer the opportunity for our medical and science students and also the general public to get to know about new developments in the field of brain research achieved by both Maltese and foreign scientists.peer-reviewe

Topological aspects of generalized Harper operators

A generalized version of the TKNN-equations computing Hall conductances for generalized Dirac-like Harper operators is derived. Geometrically these equations relate Chern numbers of suitable (dual) bundles naturally associated to spectral projections of the operators.Comment: 8 pages; needs aipproc.cls and corresponding style files. To appear in: "The Eight International Conference on Progress in Theoretical Physics", Mentouri University, Constantine, Algeria, October 2011; Conference proceedings of the AIP, edited by N. Mebarki and J. Mimoun

Generalized TKNN-equations

We derive generalized TKNN-equations via bundle representations of the noncommutative torus with rational deformation parameter, the bundle coming from spectral projections in the torus algebra. These equations relate Chern numbers of dual bundles which we interpret as Hall conductances for Dirac-like Hamiltonians describing magnetic Bloch electrons in a strong magnetic field. We also present their generalizations for irrational values of the deformation parameter.Comment: v2: 32 pages; Sect. 1 and Sect. 2.5 partially rewritten; additional minor corrections; references added. Key words: TKNN-equations, Noncommutative torus, vector bundles, Chern number

Nicotine addiction : a review

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 findings 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 on 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 affected by nicotine. These include serotonergic pathways and central cannabinoid receptors. Despite the scarcity of approved drugs and partial efficacy of approved treatment, insight into nicotine neurophysiological modulation led to 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 effective treatments of both nicotine dependence and nicotine rewarding effects.peer-reviewe

The Palaearctic species of Pristaulacus Kieffer, 1900 (Hymenoptera, Aulacidae) : remarks on taxonomy, systematic, and biogeography

Taxonomic, systematic, and biogeography knowledge on the Palaearctic species of Pristaulacus Kieffer 1900 is summarized. Twenty-one valid species are recognized. The most important morphological characters taken into consideration are: shape, cuticular sculpture, and pubescence of head; index length/width of antennomeres; shape, sculpture and cuticular processes of mesosoma, especially of pronotum and mesonotum; number and shape of teeth on claw; shape and sculpture of metasoma; ovipositor length compared with wing and antenna length; and colour pattern (e.g., the dark spots on fore wing, and the colour of hind tarsus). Several characters of the genital capsule of the male were proved to be very useful for species identification, e.g., the shape of the paramere, volsella, cuspis, and digitus. Based on analysis of twenty-five morphological characters, eight species groups are recognized. The critical revision of the chorological data, including many new records, introduced relevant changes of the geographical distribution pattern of most species. Twelve species are restricted to the western part of the Palaearctic Region and eight species are restricted to its eastern part; only one species, P. gibbator, has a wider distribution, including both western and eastern parts of the Palaearctics

Interview with the Co-ordinator of the Malta Neuroscience Network

Iggy Fenech interviews the Co-ordinator of the Malta Neuroscience Network, Professor Giuseppe Di Giovanni. He is a neuroscientist. For more than 2 decades, his research has focused on understanding the patho- physiology of central monoaminergic systems in di fferent neuropsychiatric disorders such as depression, schizophrenia, drug abuse, Parkinson's disease and epilepsy.peer-reviewe

5-Hydroxy-3-(4-hydroxyphenyl)-8,8-dimethyl-6- (3-methylbut-2-enyl)pyrano[2,3-h]chromen-4-one

Natural and semi-synthetic compounds are being studied as novel phosphodiesterase 5 (PDE5) inhibitors for the treatment of erectile dysfunction, pulmonary hypertension, and lower urinary symptoms. Maclura pomifera is a source of flavonoids, one of the main classes of molecules investigated for these purposes. The extraction of the natural isoflavone osajin and its modification to obtain a semi-synthetic derivative are described in this short note. 1H and 13C-nuclear magnetic resonance spectroscopy (NMR), mass spectrometry, high-performance liquid chromatography (HPLC) and spectroscopic characterization of the title compound are also hereby provided. Two-dimensional (2D) nuclear Overhauser effect spectroscopy (NOESY) NMR, supported by in silico conformational studies, was used to achieve a complete assignment of the proton signals, assessing the correct chemical structure of the compound. Heteronuclear single quantum coherence spectroscopy (HSQC) and heteronuclear multiple bond correlation (HMBC) NMR experiments were performed to assign 13C chemical shifts. Calculated chemical properties and preliminary in silico docking suggest that this molecule might be a promising candidate as PDE5 inhibitor

Getting Close Without Touching: Near-Gathering for Autonomous Mobile Robots

In this paper we study the Near-Gathering problem for a finite set of dimensionless, deterministic, asynchronous, anonymous, oblivious and autonomous mobile robots with limited visibility moving in the Euclidean plane in Look-Compute-Move (LCM) cycles. In this problem, the robots have to get close enough to each other, so that every robot can see all the others, without touching (i.e., colliding with) any other robot. The importance of solving the Near-Gathering problem is that it makes it possible to overcome the restriction of having robots with limited visibility. Hence it allows to exploit all the studies (the majority, actually) done on this topic in the unlimited visibility setting. Indeed, after the robots get close enough to each other, they are able to see all the robots in the system, a scenario that is similar to the one where the robots have unlimited visibility. We present the first (deterministic) algorithm for the Near-Gathering problem, to the best of our knowledge, which allows a set of autonomous mobile robots to nearly gather within finite time without ever colliding. Our algorithm assumes some reasonable conditions on the input configuration (the Near-Gathering problem is easily seen to be unsolvable in general). Further, all the robots are assumed to have a compass (hence they agree on the "North" direction), but they do not necessarily have the same handedness (hence they may disagree on the clockwise direction). We also show how the robots can detect termination, i.e., detect when the Near-Gathering problem has been solved. This is crucial when the robots have to perform a generic task after having nearly gathered. We show that termination detection can be obtained even if the total number of robots is unknown to the robots themselves (i.e., it is not a parameter of the algorithm), and robots have no way to explicitly communicate.Comment: 25 pages, 8 fiugre