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Xjenza Online Vol. 6 Iss. 2 - December 2018
Xjenza Online Vol. 6 Iss. 2 - December 2018 ISSUE: Xjenza Online Vol. 6 Iss. 2 - December 2018



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Editorial
Editorial
Cristiana Sebu
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Article
Estimates of Input-Output Multipliers for the Maltese Economy Based on the Symmetric Input-Output Table for 2010
Ian P. Cassar, Noel Rapa
Pages: 70 - 85
Abstract | View full article | PDF
Abstract:
The study presents the estimates of industry specific multipliers which are derived utilizing a highly disaggregated symmetric input-output table for the Maltese Economy for 2010, published by the National Statistics Office of Malta in 2016. The aim of this study is to derive and analyse a set of output, value added, income and employment multipliers, which illustrate how an exogenous shock to the final demand of each industry would affect the production activities of the Maltese economy on the basis of the Leontief demand driven model. Both the open, as well as the closed Leontief demand driven model are utilized in order to derive the simple and total multipliers. The study presents a comparative analysis of the direct, indirect and induced multiplier effects in terms of the output, value added, income and employment generation for each industry within the Maltese economy. Although there is a considerable degree of heterogeneity in the results obtained across the various multiplier measures, when considering the complete set of multiplier results, a number of industries do feature as relatively strong performers across all categories of multipliers. The accommodation and food services activities feature in the top 15 in almost all categories of multipliers under consideration, confirming the historic tendency for the tourism sector to feature as a key important economic driver. The sectors associated with the public sector, more specifically the public administration, education and human health sectors, were also found to consistently exhibit relatively strong multiplier effects.

Doi: 10.7423/XJENZA.2018.2.01
Article
A Review of Studies Investigating the Dielectric Properties of Biological Tissues for Application in Hyperthermia and Microwave Thermal Ablation
Julian Bonello, Lourdes Farrugia, Charles V. Sammut
Pages: 86 - 93
Abstract | View full article | PDF
Abstract:
Heating of biological tissues beyond 40 C has become an established method of treating a number of diseases, most notably tumours, where hyperthermia and thermal ablation are important modalities. In some interventions, tissue temperatures reached can even go beyond 100 C, and demand precise knowledge of tissue dielectric properties and how these vary with frequency and temperature in order to facilitate accurate computational simulations for preclinical planning. This paper reviews the available literature concerning dielectric properties of biological tissues and their temperature dependence, focusing on the frequencies of 915MHz and 2.45 GHz, at which most of the studies reviewed investigate predominantly liver tissue. In this review a comparative analysis of the results obtained by different research groups are presented in the different studies is also made, indicating possible limiting factors in the different studies. These studies propose a number of different models which could be used to describe temperature dependence. Due to the prevalence of liver investigations, it would be ideal to conduct further studies on different biological tissues.

Doi: 10.7423/XJENZA.2018.2.02
Article
Action Observation and Execution Network: An Extended View
Rozzi Stefano, Gerbella Marzio, Rizzolatti Giacomo
Pages: 94 - 109
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Abstract:
The mirror mechanism is a basic mechanism that transforms sensory representations of others’ behaviours into one’s own motor or visceromotor representations concerning that behaviour. In this review, we examine the different functions of the mirror mechanism according to its location in the brain, with particular emphasis on recent data concerning the prefrontal cortex and the emotional centres.

Doi: 10.7423/XJENZA.2018.2.03
Article
Banking on You? The Level of Public Awareness of Biobanks in Malta
Maria Desira, Gillian M. Martin
Pages: 110 - 116
Abstract | View full article | PDF
Abstract:
This paper explores the level of awareness of the Maltese general public in relation to the existence and use of biobanks as resources for biomedical and genomic research. Using a quantitative research design, a four question survey was administered face-toface to a random stratified quota sample (n = 387) of the Maltese population. The survey assessed whether the general public understands what a biobank is, and what the people believe/ think a biobank might be. Results show that the overwhelming majority of the public is not aware of the term ‘biobank’, and when asked to think about what a biobank could be, the majority of these failed to give an accurate answer, with a financial institution being the most frequent suggestion. This said, 26.5% of those who initially claimed that they did not know what a biobank is (or claimed they were not sure) went on to give a legitimate response when asked to speculate about what a biobank could be. Most of these respondents mentioned biobanks which store gametes and/or embryos and biobanks which store blood and organs for the purpose of donation. Whilst gender does not seem to be a significant factor in the outcome as an independant variable, educational achievement did have an influence on the accuracy of the responses. The key finding is that only 2.3% of the Maltese population promptly associated the term ‘biobank’ with a facility for storing tissue for the purpose of biomedical research, while the vast majority believed it referred to a financial institution.

Doi: 10.7423/XJENZA.2018.2.04
Article
Maltese Microalgae and Global Climate Variability
Kristina Fenech, Sarah Schembri, Gabrielle Zammit
Pages: 117 - 126
Abstract | View full article | PDF
Abstract:
The biodiversity of cyanobacteria and microalgae growing in terrestrial and marine habitats around the Maltese islands is currently being investigated, as limited knowledge exists about the phototrophic microorganisms inhabiting this geographical area. New strains of the genera Oculatella, Albertania, Nodosilinea, Nostoc, Lyngbya, Oscillatoria, Calothrix and Jenufa have been recorded recently. Since the phototrophic microbial biodiversity is currently largely unknown, there is an imminent risk of undescribed microorganisms being lost as a result of changes in microbial community structures due to global climate variability (GCV). We describe a six-month experiment to assess the effects of GCV on two Maltese microorganisms, the filamentous heterocytous cyanobacterial Nostoc strain AD0303 and a coccal microalgal Jenufa strain AD0402. Each strain was cultured under environmental conditions associated with GCV; a temperature (T) of 26 C, enhanced ultraviolet radiation (UVR) and an increased CO2 concentration. Elevated T stimulated growth and biomass accumulation of Nostoc AD0303, whereas growth of Jenufa AD0402 was partially inhibited. Increased UVR had the most prominent effect on cellular morphology. Nostoc AD0303 presented as aggregated filaments, whereas Jenufa AD0402 exhibited thicker cell walls. These UVprotecting mechanisms allowed both strains to accumulate biomass at a significantly higher rate than the control. An increase in CO2 concentration resulted in inhibition of growth in Jenufa AD0402 and bleaching of filaments in Nostoc AD0303, both leading to culture death. A lower CO2 concentration and re-introduction of air subsequently allowed Jenufa AD0402 to grow. So far, this demonstrates that the effects imposed by climate variability are strain-specific, making changes at an ecosystem level difficult to predict.

Doi: 10.7423/XJENZA.2018.2.05
Article
Time Variation, Asymmetry and Threshold Effects in Malta’s Phillips Curve
William Gatt
Pages: 127 - 140
Abstract | View full article | PDF
Abstract:
This paper estimates a Phillips curve for Malta using data since the 1960s, using Bayesian methods to estimate a time-varying parameter model with stochastic volatility. It presents evidence that the curve has flattened over time. This implies that the link between inflation and economic activity has weakened, consistent with findings for other countries. This phenomenon is driven by downward price stickiness and threshold effects, where inflation is generally unresponsive to domestic economic conditions unless the economy is going through a strong boom. Meanwhile, this study finds an increasingly important role for import price shocks in driving inflation in the Maltese economy, owing to its increased openness and trade integration. The estimated variance of shocks to inflation was high in the 1980s, but has fallen greatly since then, rising somewhat in the run-up to the Great Recession.

Doi: 10.7423/XJENZA.2018.2.06
Article
The Development of the Sympathetic System of the Heart
Gary Bonnici, Yimeng Zhang, Jean Calleja-Agius, Pierre Schembri-Wismayer
Pages: 141 - 152
Abstract | View full article | PDF
Abstract:
Development of the sympathetic nervous system begins at about embryonic day 9 in mice with the migration of the neural crest cells to the dorsal aorta and the development of neurons and the sympathetic ganglia. This is followed by the axonal elongation towards the developing cardiac tissue. This process is directed by a series of signal ligands including ephrin-B1, semaphorin 3a (Sema3a), F-Spondin, bone morphogenetic proteins (BMPs), Wnt-1 protein, neurotrophin-3 (NT-3), nerve growth factor (NGF) and artemin (ARTN). Once at the developing heart, the nerve fibres follow the coronary veins in the subepicardium using NGF and the chemorepellent Sema3a as signals. Here they interact with the cardiac conduction system. Although these cardiac neural cells are part of the autonomic system, they are developed later, mainly on the epicardial surface. Bilateral innervation of the heart comes from the middle cervical stellate (MC-S) ganglion. Although the left ventricle and atrium receive noradrenaline from the MC-S on both sides, the right ventricle receives more from the MC-S from the left rather than from the right side. The development of the great vessels also contributes towards the pattern of development of cardiac innervation. The afferent fibres leaving the heart are also described. Their development relates to the sympathetic innervation of the heart and therefore to cardiac sensations. We hypothesise about how this reflects on the patterns of ischaemic cardiac pain.

Doi: 10.7423/XJENZA.2018.2.07
Article
Does Absence of Charismatic Species Impact the Ecotourism Potential of Central Mediterranean Islands?
Karl Agius, Nadia Theuma, Alan Deidun
Pages: 153 - 164
Abstract | View full article | PDF
Abstract:
Central Mediterranean Islands tend to be devoid of large terrestrial charismatic fauna which usually serve as target species for ecotourism. This has raised questions on the potential of ecotourism in such destinations. However it has been argued that absence of charismatic megafauna should not be considered as a limitation. Ecotours were organised on nine islands in the central Mediterranean region. Interviews and focus groups were held with participants of the ecotours and stakeholders. It has been argued that most charismatic species are marine, touting marine ecotourism as the ideal tourism product. Furthermore, rather than focusing on charismatic species, the ecotourism product on such islands should revolve around the various coastal environments and habitats and other smaller species including non-mammals, especially endemic ones thus facilitating a broader approach to conservation. Owing to the remarkable biodiversity of plant species, charismatic megaflora and plants have also been identified as important targets for ecotourism. Furthermore, due to the intense environmental pressure and limited size of protected areas the overlap with cultural, rural and adventure tourism has been suggested. In order for the ecotourism product to be more competitive archipelago tourism also referred to as island hopping is also recommended, a proposal which is supported by the presence of endemic and sub-endemic species. Results show that absence of charismatic species does not limit ecotourism development on such islands.

Doi: 10.7423/XJENZA.2018.2.08
Article
The 36th European Seismological Commission General Assembly
Sebastiano D’Amico, Pauline Galea, Matthew R. Agius, George Bozionelos, Daniela Farrugia, Emanuele Colica
Pages: 165 - 167
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