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Xjenza Online Vol. 10 Iss. 1
Xjenza Online Vol. 10 Iss. 1 ISSUE: Xjenza Online Vol. 10 Iss. 1


In Our Commitment to Science

Tracking Caretta caretta: Movement patterns following rehabilitation in Malta
Martina Cutajar, Celine Ferlat, Vincent Attard, Anthony Gruppetta
Pages: 2 - 14
Abstract | View full article | PDF
GPS tracking through the use of satellite transmitters has proved to be a useful technology in identifying migratory patterns in juvenile and adult sea turtles, despite being a relatively new tool in behavioural biology. This technology has allowed tracking to take place over larger areas and for longer periods of time than previously possible. Loggerhead sea turtles (Caretta caretta) are able to travel over large distances throughout their life, being able to travel up to 13,000 km in one year, visiting distant areas and often demonstrating complex patterns of movement both as juveniles and adults. However, information on the tracking of loggerhead turtles rehabilitated and released from the Maltese islands is scarce. This study followed the paths taken by five loggerhead sea turtles, four of which were juveniles while one was a full male adult. All turtles were rescued in Maltese waters and rehabilitated at the Aquaculture Directorate at Fort San Luċjan. The turtles spent between 205 and 1550 days at the rehabilitation centre, depending on the severity of their injuries. Three of these turtles were missing either a front or a hind limb. Turtle movements were recorded as X-Y coordinates using Argos System Applications. This information was gathered using Collecte Localisation Satellite (CLS). Following release, all five turtles were observed to frequent the same main region to the South of the Maltese islands, typically the Libyan and Tunisian neritic coastal zones, with few discrepancies also being recorded. The maximum daily speed recorded ranged between 2.4 and 8.0 km/h. The total distance travelled by the turtles under study ranged between 1375 km and 3273 km in 92 and 292 days respectively. The five turtles covered similar mean distances (11.2 – 22.4 km/day), despite differences in their life-stages and physical abilities. These results suggest that despite their physical limitations, turtles having missing limbs moved at speeds and covered distances comparable to their fully able counterparts.

Doi: 10.7423/XJENZA.2022.1.01
Self-reported stressors and experiences of Maltese dental academics during the COVID-19 pandemic
Anne-Marie Agius, Ethel Vento Zahra, Gabriella Gatt, Arthur R. G. Cortes, Nikolai Attard
Pages: 15 - 22
Abstract | View full article | PDF
Aim: to compare self-reported outcomes among dental faculty members during the COVID-19 pandemic.
Materials and methods: An anonymous questionnaire consisting of 13 closed and open-ended questions was sent to all faculty members (n=41) at the Faculty of Dental Surgery at the university of this study. Categorical (likert-scale) and qualitative questions on self-reported outcomes were identified and tallied. Non-parametric tests were used to correlate and compare variables among the different gender, departments and roles of the academics (i.e. full-time, part-time, visiting and demonstrators).
Results: Thirty-two (32) out of fourty-one (41) academics completed the online questionnaire. A satisfactory adaptation to online lecturing was noted from the majority of the participants. On the other hand, full-time faculty members were significantly more anxious about contracting COVID-19, than part-time and visiting faculty members (p=0.020). Most participants were concerned about the lack of practical training opportunities for students. There were no significant differences between gender categories for any of the variables explored in this study (p>0.05).
Conclusion: Academics accepted online platforms for lecturing and examinations as viable alternatives to traditional methods for theoretical learning but they were highly concerned about the possibility of students losing their practical skills during the lockdown and that online tutoring cannot compensate for lost hands-on time in preparation for their upcoming practical examinations. They, however, recognized the benefits of blended modes of tuition in the future.

Doi: 10.7423/XJENZA.2022.1.02
Identifying risk factors of aortic valve replacement using survival frailty models
Liberato Camilleri, Lawrence Grech, Alexander Manché
Pages: 23 - 29
Abstract | View full article | PDF
Traditional survival modeling techniques, including the Kaplan Meier estimator, Cox regression and parametric survival models assume a fairly homogeneous population, where variation in survival durations can be explained by a small number of observed explanatory variables. However, in the presence of heterogeneity, frailty models are more appropriate to model survival data by introducing random effects that account for the variability generated from unobserved covariates. This paper presents two types of frailty models. The unshared frailty model assumes that different individuals have distinct frailties, while the shared frailty model assumes that the population can be divided into clusters, where members in the same cluster share the same frailty. Due to their nice mathematical properties, the Gamma and the Inverse Gaussian distributions are the most popular choices for the frailty distribution.

These survival models are fitted to a data set using the facilities of STATA. The participants are patients who underwent an aortic valve replacement procedure at a Maltese hospital between 2003 and 2019. The dependent variable is the duration till death or till censored and the eleven predictors provide information about the patients’ health condition; surgery operative procedures; and duration of convalesce period. Moreover, in shared frailty models the patients are clustered by their diabetic condition since it is known that diabetic patients are more at risk of dying following aortic surgery.

Doi: 10.7423/XJENZA.2022.1.03
Analysis on how COVID-19 is affecting health care workers
Sheriseane Diacono, Rebecca Caruana, David Zammit
Pages: 30 - 36
Abstract | View full article | PDF
The COVID-19 pandemic has impacted most of the world’s population, in this paper we are interested particularly in how it has impacted directly the healthcare workers and front-liners working in Malta. The questionnaire conducted focused on issues that impacted them directly and indirectly such as stress levels, work load, and their psychological well-being. Whilst it is evidence that during the pandemic, health care workers were faced with psychological challenges, health care professionals working in Malta still shy away from looking for help for various reasons such as lack of resources, lack of education and fear of stigma. Through this research, it seems that the way forward during these challenging times is to increase the support from government entities, to increase education and awareness regarding mental health and support.

Doi: 10.7423/XJENZA.2022.1.04
Block Decomposition of Price Multipliers in a SAM Framework for Malta
Adrian Theuma, Kevin Abela
Pages: 36 - 46
Abstract | View full article | PDF
A social accounting matrix can be utilised to model prices, providing a deeper understanding on price effects linked to intersectoral linkages, wages costs and cost-of-living adjustments. The objective of this article is to estimate price multipliers and their decomposition effects for the Maltese economy, based on the 2010 micro social accounting matrix. The estimated price multipliers follow the methodological framework proposed by (Roland-Holst and Sancho (1995). The aim is to capture all existing price multiplier effects which are embedded within the entire circular flow of income and expenditure. This paper presents the first block decomposition of price multipliers locally with the objective to estimate and distinguish between transfer, open-loop and closed-loop effects. Therefore, this paper provides additional insight on tracing the different price effects following exogenous cost injections. Findings portray that the effects on production activities following injection in the same production account is dominated mainly by transfer effects. However, the price multiplier effects on endogenous accounts following an injection in production activities would result in mainly open-loop effects. The effects of higher wage costs on production activities and households are mainly dominated by open-loop effects, followed by induced effects. The estimated price multipliers can be utilised for policy formulation but are subject to the traditional input-output framework assumptions. However, the estimated price multipliers provide a first cut estimate of assessing price effects in terms of intermediary input costs, wages costs and cost-of-living adjustments following exogenous cost changes.

Doi: 10.7423/XJENZA.2022.1.05
Elastomers for the Development of Orthopaedic Implants - A Review
Dylan Abela, Arif Rochman, Joseph Buhagiar, Pierluigi Mollicone, Pierre Schembri-Wismayer
Pages: 48 - 60
Abstract | View full article | PDF
There has been an increase in the use of elastomers in the biomedical industry. Recent developments in utilising elastomers for use in orthopaedic implants has shown the great potential of these materials for long-term implantation.
Elastomers are being developed for applications in tissue engineering, polymeric scaffolds and synthetic implants, all with the aim of repairing or maintaining orthopaedic joints in working order. The aim of this review is to discuss current developments in elastomeric orthopaedic implants and their most utilised materials namely silicones, polyurethanes and hydrogels. Polyurethane and silicone elastomers are commonly used in bulk implantable devices due to their good mechanical properties, chemical resistance and biocompatibility.
Other materials such as polycarbonate urethanes (PCUs) are being utilised as means to protect the joints due to their superb mechanical properties and wear characteristics.
The range of applications of elastomers vary from hip joint replacements, such as in the case of the TriboFit implant, meniscal implants, and first metatarsophalangeal joint replacements. More recently hydrogels have been utilised as coatings for increased lubrication in joint replacements, as a substitute for articular cartilage.
Applications of hydrogels vary from improving the collagen and proteoglycan content of the joint to improving the load distribution across the joint in arthritic knee joints. The use of elastomers in orthopaedic implants is still in its infancy; and whilst a large amount of the research being done is still in the prototype stages, the potential of these materials and devices is unlimited.

Doi: 10.7423/XJENZA.2022.1.06