Jorge C. Pereira

Accessibility levels of Portuguese enterprise websites: equal opportunities for all?

Web accessibility is growing in importance. We may also find an increasing need for access to web resources by those with some sort of disability. The Web is very important for spreading information and for promoting interaction between the various elements in society. Given this, it is essential that the Web presents itself as a totally accessible resource, so that it can help citizens with disabilities and their integration in society. This obligation should be even greater for enterprises as primarily the Web is used as a marketing and business platform. With this document, we present indicators regarding the [lack of] accessibility levels of Portuguese enterprise websites. This article contains theoretical and background considerations as well as the results of two different studies that the research team undertook. First of all, the research team made a comparison between the 1000 largest Portuguese enterprises (annual sales volume) and the 1000 best Portuguese small and medium enterprises (sales growth and profit) using a specialised software tool and according to Web Content Accessibility Guidelines (WCAG) 1.0; the research team then also considered WCAG 2.0 and its impact on enterprise Web accessibility. In the second study (qualitative in nature), focus group interactions led to a set of recommendations towards greater accessibility.

An Efficient Method for Genomic DNA Extraction from Different Molluscs Species

The selection of a DNA extraction method is a critical step when subsequent analysis depends on the DNA quality and quantity. Unlike mammals, for which several capable DNA extraction methods have been developed, for molluscs the availability of optimized genomic DNA extraction protocols is clearly insufficient. Several aspects such as animal physiology, the type (e.g., adductor muscle or gills) or quantity of tissue, can explain the lack of efficiency (quality and yield) in molluscs genomic DNA extraction procedure. In an attempt to overcome these aspects, this work describes an efficient method for molluscs genomic DNA extraction that was tested in several species from different orders: Veneridae, Ostreidae, Anomiidae, Cardiidae (Bivalvia) and Muricidae (Gastropoda), with different weight sample tissues. The isolated DNA was of high molecular weight with high yield and purity, even with reduced quantities of tissue. Moreover, the genomic DNA isolated, demonstrated to be suitable for several downstream molecular techniques, such as PCR sequencing among others.

Genetic diversity of two Portuguese populations of the pullet carpet shell Venerupis senegalensis, based on RAPD markers: contribution to a sustainable restocking program

The pullet carpet shell Venerupis senegalensis (=V. pullastra) is a commercially important species in Portugal, Spain, France, and Italy. In Portugal, this species was once abundant in the Ria Formosa (southern Portugal). However, in the early 1980s, its abundance declined dramatically due to overfishing. In order to reverse this negative trend, the genetic sustainable management of the wild stocks of V. senegalensis should be performed by promoting successful restocking actions and the development of an aquaculture commercial production program of this species. In order to find the best broodstock for aquaculture purposes and therefore minimize the deleterious effects of hatchery practices, we analyzed the genetic diversity of the natural population to be restocked (Ria Formosa) but also of another potential genetically close population (Ria de Aveiro) by RAPD. Similar and substantive percentage of polymorphic loci, effective number of alleles, Nei’s gene diversity, and Shannon’s diversity index was found within both populations. This high genetic variability within populations suggests that they might have a gene pool with sufficient genetic plasticity to support changes in the environmental conditions. Analyses of population genetic structure also revealed a small genetic differentiation between the two populations. The high genetic variability of the natural population to be restocked makes it the preferential broodstock for aquaculture purposes. However, the Ria de Aveiro population could also be a viable alternative, due to its genetic plasticity and the genetic similarity of both populations. The results of this study can be useful to the sustainable management of wild stocks as well as in promoting successful restocking actions based on aquaculture production.

Social networks sites adoption at firm level: A literature review

The current technological and social Era in which our society lives, provides for the necessary background in order for Social Networks Sites (SNS) to be considered an essential and very relevant tool not only for individual social interaction, but also for firms to perform business activities. By analyzing the existent literature on the SNS adoption at firm level, the authors perceived the existence of a knowledge gap on this topic, thus creating the need for a SNS related literature review. In this paper, we present a systematic literature review on the SNS topic, mainly focusing the efforts towards the adoption of this technology at firm level. Some final considerations on future research are also presented in the final section of the article.

Cytogenetic Characterization of the Dwarf Oyster Ostrea stentina (Mollusca: Bivalvia) and Comparative Karyological Analysis within Ostreinae

ABSTRACT Regardless of the high economic value and large geographical distribution of oysters, the current knowledge of oyster taxonomic relationships and systematics is still limited, particularly for flat oysters. In this study, the molecular cytogenetic characterization of mitotic chromosomes of the Provence flat oyster or dwarf oyster, Ostrea stentina, was performed through Giemsa staining, chromosome measurements, in situ restriction endonuclease banding, C-banding, fluorescence in situ hybridization with major ribosomal RNA genes (ITS1), and telomeric sequence (TTAGGG)n. The karyotype (2n = 20) consisted of 6 metacentric (1, 3, 4, 6, 8, and 10) and 4 submetacentric (2, 5, 7, and 9) chromosome pairs. Chromosome treatment with HaeIII produced specific banding patterns for all chromosomal pairs, confirming the efficiency of this restriction enzyme for chromosome banding in oysters. Results for C-banding revealed the presence of heterochromatin in the telomeric regions of the short arms: on a large metacentric chromosomal pair and on a submetacentric chromosomal pair. In situ hybridization with telomeric sequence revealed bright hybridization signals in the telomeres of all chromosomes. The location of the major ribosomal rDNA (ITS1) displayed the presence of 2 signals: in the telomeric regions of the short arms of the largest metacentric chromosome and in a submetacentric chromosome. The cytogenetic data obtained was used to perform a comparative karyological analysis within the subfamily Ostreinae. It is also important to highlight that this type of work can provide new insights on major genomic changes at the chromosome level in the flat oysters.