966 research outputs found
Diversity and function of phage encoded depolymerases
Bacteriophages of the Podoviridae family often exhibit so-called depolymerases as structural components of the virion. These enzymes appear as tail spike proteins (TSPs). After specific binding to capsular polysaccharides (CPS), exopolysaccharides (EPS) or lipopolysaccharide (LPS) of the host bacteria, polysaccharide-repeating units are specifically cleaved. Finally, the phage reaches the last barrier, the cell wall, injects its DNA, and infects the cell. Recently, similar enzymes from bacteriophages of the Ackermannviridae, Myoviridae, and Siphoviridae families were also described. In this mini-review the diversity and function of phage encoded CPS-, EPS-, and LPSdegrading depolymerases is summarized. The function of the enzymes is described in terms of substrate specificity and applications in biotechnology
Novel phylogenetic algorithm to monitor human tropism in Egyptian H5N1-HPAIV reveals evolution toward efficient human-to-human transmission
Years of endemic infections with highly pathogenic avian influenza (HPAI) A subtype H5N1 virus in poultry and high numbers of infections in humans provide ample opportunity in Egypt for H5N1-HPAIV to develop pandemic potential. In an effort to better understand the viral determinants that facilitate human infections of the Egyptian H5N1-HPAIVvirus, we developed a new phylogenetic algorithm based on a new distance measure derived from the informational spectrum method (ISM). This new approach, which describes functional aspects of the evolution of the hemagglutinin subunit 1 (HA1), revealed a growing group G2 of H5N1-HPAIV in Egypt after 2009 that acquired new informational spectrum (IS) properties suggestive of an increased human tropism and pandemic potential. While in 2006 all viruses in Egypt belonged to the G1 group, by 2011 these viruses were virtually replaced by G2 viruses. All of the G2 viruses displayed four characteristic mutations (D43N, S120(D,N), (S,L)129Δ and I151T), three of which were previously reported to increase binding to the human receptor. Already in 2006–2008 G2 viruses were significantly (p<0.02) more often found in humans than expected from their overall prevalence and this further increased in 2009–2011 (p<0.007). Our approach also identified viruses that acquired additional mutations that we predict to further enhance their human tropism. The extensive evolution of Egyptian H5N1-HPAIV towards a preferential human tropism underlines an urgent need to closely monitor these viruses with respect to molecular determinants of virulence
BYOD: Risk considerations in a South African organisation
In recent times, while numerous organisations have difficulty keeping abreast with the frequent year-on-year technology changes, their employees on the other hand, continue to bring their personal devices to work to more readily access organisational data. This concept is known as Bring Your Own Device (BYOD). Studies have demonstrated that the introduction of BYOD commonly has a positive effect on both organisation and employees: increased optimism, job satisfaction and productivity are some of the perceived positive effects. Furthermore, BYOD can improve employees’ opportunities for mobile working and assist with the work flexibility they seek. This phenomenon, however, is still not well understood. In the South African context, this refers particularly to an inadequate understanding of risks associated with the introduction of BYOD into organisations. Some of the risks associated with this phenomenon are, for instance, related to information security, legislation and privacy issues. Hence, the intention of this research was to investigate, determine and assess BYOD risk considerations in a South African organisation. Using the available literature on this subject and an interpretative exploratory case study approach, this research explored various facets of BYOD-related risks (e.g. implementational, technological, legislation, regulation and privacy risks, human aspects and organisational concerns) as well as the impact these risks may have on both employees and an organisation. The organisation under investigation – from this point onward referred to as “Organisation A” – is a South African based information technology (IT) security consulting and service management organisation, which has seen increased expansion in its business and thus an increase in the number of its employees utilising their personal devices at the workplace. Even so, Organisation A was uncertain regarding possible risks that might hinder benefits of BYOD. Hence, this researcher defined the main research question as “What are the risks of introducing the BYOD in the South African organisation and what is an effective approach to address identified risks?”. The main objective was to identify and describe BYOD-related risks and to propose an appropriate model for addressing these risks. To answer the main research question, this researcher reviewed the applicable literature on the BYOD, including the limited South African literature pertaining to the subject. The review elicited the most common BYOD-related risks but also some models, frameworks and standards that may be applied for addressing these risks. Based on these revelations, an applicable BYOD risk management model was created and proposed. The literature review findings were subsequently tested in the empirical setting (in Organisation A) by conducting comprehensive interviews with research participants. This research adopted a qualitative approach in general and a case study methodology in particular. The collected data were analysed using the interpretative phenomenological analysis (IPA), which aided in providing a comprehensive understanding of the interviewees’ responses regarding the BYOD risks. The interviewees were selected based on a purposeful (pre-defined) sampling. The results of this interpretative research suggest that the interviewees’ responses are closely aligned with the information on BYOD risks collected from the pertinent literature. The results show that successful introduction and usage of BYOD in the studied organisation requires the implementation of mixed risk management measures: technological (e.g. mobile device management and its additional components), non-technological (e.g. IT or BYOD security policies), the usage of general risk management frameworks (e.g. ISO 27001), the development of an organisational security culture and skilling of the human factor (e.g. employee awareness, training and education, for example). Additionally, it was found that participation of employees in the development of BYOD policies is an essential and effective tactic for transforming a fragile BYOD risk link (i.e. employees) into a strong risk prevention mechanism. Furthermore, this research also revealed that in the South African context, it is important that an organisation’s BYOD security policies are sound, preferably meeting the POPI Act requirements and thereby avoiding legislation risks. The contribution of this research is twofold: first academic, and second, practical. The academic contribution is realised by adding to the body of knowledge on the BYOD risks – most particularly in terms of understanding potential risks when introducing BYOD in the South African context. The practical contribution manifests through the provision of detailed risk considerations and mitigation guidelines for organisations wishing to introduce BYOD practices or considering ways to improve their current BYOD risk management strategy. It is acknowledged that this research has some limitations, particularly in regard to the limited generalisation of the findings due to the limited sample provided by only one organisation. Although the results are not necessarily applicable to other South African organisations, these limitations did not impact the relevance and validity of this research
Physical Activity and Natural Anti-VIP Antibodies: Potential Role in Breast and Prostate Cancer Therapy
BACKGROUND: There is convincing evidence from numerous clinical and epidemiological studies that physical activity can reduce the risk for breast and prostate cancer. The biological mechanisms underlying this phenomenon remain elusive. Herein we suggest a role for naturally produced antibodies reactive with the vasoactive intestinal peptide (VIP) in the suppression of breast and prostate cancer, which we believe could offer a possible molecular mechanism underlying control of these cancers by physical exercise. METHODOLOGY AND RESULTS: We found that sera from individuals having breast and prostate cancers have decreased titers of VIP natural antibodies as demonstrated by a lower reactivity against peptide NTM1, having similar informational and structural properties as VIP. In contrast, sera collected from elite athletes, exhibited titers of natural NTM1-reactive antibodies that are significantly increased, suggesting that physical activity boosts production of these antibodies. SIGNIFICANCE: Presented results suggest that physical exercise stimulates production of natural anti-VIP antibodies and likely results in suppression of VIP. This, in turn, may play a protective role against breast and prostate cancers. Physical exercise should be further investigated as a potential tool in the treatment of these diseases
Characterization of conserved properties of hemagglutinin of H5N1 and human influenza viruses: possible consequences for therapy and infection control
<p>Abstract</p> <p>Background</p> <p>Epidemics caused by highly pathogenic avian influenza virus (HPAIV) are a continuing threat to human health and to the world's economy. The development of approaches, which help to understand the significance of structural changes resulting from the alarming mutational propensity for human-to-human transmission of HPAIV, is of particularly interest. Here we compare informational and structural properties of the hemagglutinin (HA) of H5N1 virus and human influenza virus subtypes, which are important for the receptor/virus interaction.</p> <p>Results</p> <p>Presented results revealed that HA proteins encode highly conserved information that differ between influenza virus subtypes H5N1, H1N1, H3N2, H7N7 and defined an HA domain which may modulate interaction with receptor. We also found that about one third of H5N1 viruses which are isolated during the 2006/07 influenza outbreak in Egypt possibly evolve towards receptor usage similar to that of seasonal H1N1.</p> <p>Conclusion</p> <p>The presented results may help to better understand the interaction of influenza virus with its receptor(s) and to identify new therapeutic targets for drug development.</p
Towards a Numerical Procedure for Composite Slab Assessment
Composite slab design relies upon adequate shear bond resistance between the steel and concrete. This is achieved by friction between the materials and the mechanical interlock of embossments pressed in the steel. The behaviour of this shear bond resistance is complex and is obtainable only from model tests. This paper explores the potential for numerical modelling to provide the required design information
Survey on educational material on sustainable constructions
Higher education of professionals in the construction and real estate sector is in the process of
“Greening curricula”. Pressures to educate environmentally literate workforce are increasing.
Leading construction companies worldwide are becoming involved in green construction.
“Green building, green project, green property, green procurement as well as green living and
green citizenship” are concepts that are used in business like in voluntary organisations.
The literature survey shows that technical universities worldwide have incorporated modules,
courses and programmes of sustainable construction. In general, new teaching methods
and approaches are regarded as necessary due to the complexity of triple bottom-line issues of
the sustainable construction. In addition to traditional lecturing and exercises, life-cycle and
overall performance matters are taught by methods of team-work, problem-solving and learning-
by-doing.
The material for this study was gathered from literature and virtual site visits of universities
as well as a questionnaire among the participants of the COST C25. First remarks concerning all
the material is that there are still few technical universities with a cross-cutting strategy about
sustainability. Among the participants of the C25, 50% informed about systematic educational
approach. This study is related to the initiative in the WG2 of C25 to establish a knowledge base
to support development of educational material on sustainable constructions.CostEuropean Science Foundatio
Could Spontaneous Retroperitoneal Haematoma Present with Scrotal Mass?
Background: Retroperitoneal haematoma could be caused by different factors. It is increasing due to an increase in the use of antithrombotic and anticoagulant therapy. Diagnosis of retroperitoneal haematoma forms a big challenge in daily clinical practice. Patients with retroperitoneal haematoma could present with leg paresis, abdominal pain, shock or abdominal compartment syndrome. Retroperitoneal haematoma could be treated conservatively but surgical interference or embolization of the bleeding vessels is always an option. Objectives: To present a case with spontaneous retroperitoneal haematoma presenting with scrotal haematoma together with a mini- review of retroperitoneal haematoma. Conclusions: Retroperitoneal haematoma may present with a scrotal swelling and could be treated conservatively depending on the presentation and severity of the bleeding
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