430 research outputs found
Elytrigia repens L. Desvaux ex Nevski (Poaceae), a new record for the Maltese Islands
The discovery of an indigenous population of Elytrigia repens extending for 420m through the valleybed of Wied il- Guasri, Gozo, is reported. The accompanying vegetation is described. The species' distributional range and local status are also given.peer-reviewe
The rediscovery of Asplenium trichomanes L. (Family : Aspleniaceae) in the Maltese Islands (Central Mediterranean)
Asplenium trichomanes, last recorded during the first 2 decades of the twentieth century and thereafter thought to be extinct, was rediscovered at Fuq tal-Gruwa, Ta' Cenc area, Gozo; 15 individuals were found. The accompanying garigue vegetation occuring at the site is described. The plants found belong to the subspecies quadrivalens.peer-reviewe
Second-order conditioning in Drosophila
Animals possess the ability to associate neutral stimuli in their environment with both rewards and punishment. A conditioned stimulus (CS1) such as a smell or sound, can become associated with an unconditioned stimulus (US), such as a food reward, to elicit what is known as the conditioned response (CR). This type of learning is commonly referred to as classical conditioning or first-order conditioning (FOC). Second-order conditioning (SOC) is an extension of this type of association wherein a novel stimulus is introduced (CS2) and associated with a previously conditioning first-order stimulus (CS1). As a result, the organism may show an attraction or avoidance towards the novel stimulus (CS2) even though it was never directly paired with the original unconditioned stimulus (US). In nature, there is a potential for SOC in almost any circumstance involving exposure to a sequence of learned events. For example, honeybees often memorize complex navigational pathways by associating landmarks with the presence of flowers. While a house or a tree may not reward the insect with nectar, it can be associated with a series of stimuli that eventually lead to a beneficial reward.
My work in this dissertation focuses on conclusively demonstrating SOC for the first time in Drosophila along with utilizing genetic and molecular techniques to in- vestigate the neuronal basis of this behavior. The fruit fly has numerous advantages underlying its usefulness as a model organism: its genome has been sequenced, it possesses a relatively short time of development, it can be easily subjected to genetic alterations, and it is studied by numerous laboratories around the world. Using an au- tomated, computer-controlled olfactory-based learning paradigm, I will demonstrate the ability of Drosophila to form these complex, higher-order memories initially be- lieved to be reserved only for the vertebrate learning model. In addition, I will show that Drosophila are also capable of conditioning in situations of complex odor presen- tations for both first- and second-order conditioning. Furthermore, through the use of a transgenic neuron silencing approach exclusive to the Drosophila animal model, I will examine whether previously studied neuronal circuits fulfill similar roles in both first- and second-order conditioning
Multi-stage languages in hardware design
As circuits increase in size and complexity, hardware description techniques have been trying to adopt features already well-
established in software languages. In this paper, we investigate how
different hardware description languages implement levels of abstraction over the hardware designs, and we examine how improvements
have lead to features like parameterised circuits and generic descriptions, that enable users to efficiently model and reason about large
regular-shaped structures and connection patterns. Nonetheless, the
ability to include non-functional properties of circuits in the same description is still an open issue. Lately, proposed solutions are looking
into meta-functional languages and multi-staging techniques. We examine how hardware description languages can benefit from the capabilities of meta-functional languages, which are able to reason about,
and transform the circuit generators as data objects, thus providing
a means to access both the functional and non-functional aspects of
the generated circuits.peer-reviewe
Materiality disclosures in statutory auditing : a Maltese perspective
Materiality is a fundamental auditing concept. The determination and application of materiality in the conduct of an external audit is regulated by International Standards on Auditing. This paper analysed the benefits and drawbacks of materiality disclosures in Maltese statutory auditing from the perspective of Maltese auditors, whilst measuring and explaining their resistance to such disclosures. A mixed-methods research design was adopted whereby data was collected from Maltese auditors first using a selfadministered
questionnaire, followed by semi-structured interviews. This paper concluded that the drawbacks of disclosing materiality in Maltese statutory audit reports greatly outweighed any potential benefits that might be reaped. Maltese auditors generally resisted disclosing materiality levels mainly due to the drawbacks associated with such disclosures. This paper also concluded that materiality disclosures in the audit report should, at present, be avoided in Malta because the local market is not sufficiently mature and knowledgeable to properly understand such disclosures.peer-reviewe
Bromus cathatrticus Vahl (Fam. Poaceae) : a new record for the Maltese Islands
The discoveries of the first 4 known populations of the alien Bromus catharticus from the Maltese Islands are reported. Notes on the species’ distribution range, local habitat and invasive potential are also given.peer-reviewe
Temperature Switch PCR (TSP): Robust assay design for reliable amplification and genotyping of SNPs
Background Many research and diagnostic applications rely upon the assay of individual single nucleotide polymorphisms (SNPs). Thus, methods to improve the speed and efficiency for single-marker SNP genotyping are highly desirable. Here, we describe the method of temperature-switch PCR (TSP), a biphasic four-primer PCR system with a universal primer design that permits amplification of the target locus in the first phase of thermal cycling before switching to the detection of the alleles. TSP can simplify assay design for a range of commonly used single-marker SNP genotyping methods, and reduce the requirement for individual assay optimization and operator expertise in the deployment of SNP assays. Results We demonstrate the utility of TSP for the rapid construction of robust and convenient endpoint SNP genotyping assays based on allele-specific PCR and high resolution melt analysis by generating a total of 11,232 data points. The TSP assays were performed under standardised reaction conditions, requiring minimal optimization of individual assays. High genotyping accuracy was verified by 100% concordance of TSP genotypes in a blinded study with an independent genotyping method. Conclusion Theoretically, TSP can be directly incorporated into the design of assays for most current single-marker SNP genotyping methods. TSP provides several technological advances for single-marker SNP genotyping including simplified assay design and development, increased assay specificity and genotyping accuracy, and opportunities for assay automation. By reducing the requirement for operator expertise, TSP provides opportunities to deploy a wider range of single-marker SNP genotyping methods in the laboratory. TSP has broad applications and can be deployed in any animal and plant species.Tania Tabone, Diane E Mather and Matthew J Hayde
Predicting candidate genes for human deafness disorders: a bioinformatics approach
BACKGROUND: There are more than 50 genes for autosomal dominant and autosomal recessive nonsyndromic hereditary deafness that are yet to be cloned. The human genome sequence and expression profiles of transcripts in the inner ear have aided positional cloning approaches. The knowledge of protein interactions offers additional advantages in selecting candidate genes within a mapped region. RESULTS: We have employed a bioinformatic approach to assemble the genes encoded by genomic regions that harbor various deafness loci. The genes were then in silico analyzed for their candidacy by expression pattern and ability to interact with other proteins. Such analyses have narrowed a list of 2400 genes from suspected regions of the genome to a manageable number of about 140 for further analysis. CONCLUSION: We have established a list of strong candidate genes encoded by the regions linked to various nonsyndromic hereditary hearing loss phenotypes by using a novel bioinformatic approach. The candidates presented here provide a starting point for mutational analysis in well-characterized families along with genetic linkage to refine the loci. The advantages and shortcomings of this bioinformatic approach are discussed
Access to circuit generators in embedded hdls
General purpose functional languages have been widely used as host languages for the embedding of domain specific languages, especially hardware description languages. The embedding approach provides various
abstraction techniques, enabling the description of generators for whole
families of circuits, in particular parameterised regular circuits. The two-stage language setting that is achieved by means of embedding, provides
a means to reason about the generated circuits as data objects within
the host language. Nonetheless, these circuit objects lack information
about their generators, or about the manner in which these where generated, which can be used for placement and analysis. In this paper, we
use reFLect as a functional language with reflection features, to enable us
not only to access the circuits, but also the circuit generators. Through
the use of code quotation and pattern matching, we propose a framework
through which we can access the structure of the circuit in terms of nested
blocks that map the generation flow that was followed by the generator.peer-reviewe
Corporate governance transparency in small listed entities : the case of Malta
Purpose: The objectives of this study are to examine whether a lack of transparency is a common corporate governance feature of listed entities (“MLEs”) in the small European state of Malta and, if so, to assess the possible implications of such a stance. Design/Approach/Methodology: In order to achieve such research objectives, a predominantly qualitative mixed methodology was adopted. This involved carrying out thirteen semi-structured interviews with MLE and audit firm representatives, these being supported by an examination of the corporate governance statements of MLEs for the 2015-2017 periods. Findings: Results show a general lack of transparency in corporate governance reporting, with a common MLE tendency to comply only at a superficial level with the principles of good corporate governance and thus to often fail to sustain an appropriate level of transparency and governance structures. Practical Implications: It is recomended to increase company and shareholder awareness so as to help towards further improving current attitudes. Originality/Value: The study is particularly envisaged to contribute towards encouraging stakeholders in small-state contexts to reassess their current perspectives towards corporate transparency.peer-reviewe
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