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A Cloud Forensic Readiness as a Service (CFRaaS) model allows an environmentto preemptively accumulate relevant potential digital evidence (PDE) which maybe needed during a post-event response process. The benefit of applying a CFRaaSmodel in a cloud environment, is that, it is designed to prevent the modification/tampering of the cloud architectures or the infrastructure during the reactive pro-cess, which if it could, may end up having far-reaching implications. The authorsof this article present the reactive processasaverycostlyexercisewhentheinfra-structure must be reprogrammed every time the process is conducted. This mayhamper successful investigation from the forensic experts and law enforcementagencies perspectives. The CFRaaS model, in its current state, has not been pres-ented in a way that can help to classify or visualize the different types of potentialevidence in all the cloud deployable models, and this may limit the expectationsof what or how the required PDE may be collected. To address this problem, thearticle presents the CFRaaS from a holistic ontology-driven perspective, whichallows the forensic experts to be able to apply the CFRaaS based on its simplicityof the concepts, relationship or semantics between different form of potential evi-dence, as well as how the security of a digital environment being investigatedcould be upheld. The CFRaaS in this context follows a fundamental ontologyengineering approach that is based on the classical Resource Description Frame-work. The proposed ontology-driven approach to CFRaaS is, therefore, aknowledge-base that uses layer-dependencies, which could be an essential toolkitfor digital forensic examiners and other stakeholders in cloud-security. The imple-mentation of this approach could further provide a platform to develop otherknowledge base components for cloud forensics and security

More than ever before, the world is nowadays experiencing increased cyber-attacks in all areas of our daily lives. This situation has made combating cybercrimes a daily struggle for both individuals and organisations. Furthermore, this struggle has been aggravated by the fact that today's cybercriminals have gone a step ahead and are able to employ complicated cyber-attack techniques. Some of those techniques are minuscule and inconspicuous in nature and often camouflage in the facade of authentic requests and commands. In order to combat this menace, especially after a security incident has happened, cyber security professionals as well as digital forensic investigators are always forced to sift through large and complex pools of data also known as Big Data in an effort to unveil Potential Digital Evidence (PDE) that can be used to support litigations. Gathered PDE can then be used to help investigators arrive at particular conclusions and/or decisions. In the case of cyber forensics, what makes the process even tough for investigators is the fact that Big Data often comes from multiple sources and has different file formats. Forensic investigators often have less time and budget to handle the increased demands when it comes to the analysis of these large amounts of complex data for forensic purposes. It is for this reason that the authors in this paper have realised that Deep Learning (DL), which is a subset of Artificial Intelligence (AI), has very distinct use-cases in the domain of cyber forensics, and even if many people might argue that it's not an unrivalled solution, it can help enhance the fight against cybercrime. This paper therefore proposes a generic framework for diverging DL cognitive computing techniques into Cyber Forensics (CF) hereafter referred to as the DLCF Framework. DL uses some machine learning techniques to solve problems through the use of neural networks that simulate human decision-making. Based on these grounds, DL holds the potential

The proliferation of cloud resources among organizations has had numerous benefits with regard to how business processes are conducted. However, despite the benefits, the cloud has not been very resilient due to how it is distributed and its open nature. Due to this, there have been numerous reports on how the security of organizational information has been compromised. In any organization, Digital Forensic Readiness (DFR) is employed as a pre-incident phase whose aim is to maximize the use of Potential Digital Evidence (PDE) while minimizing the cost of performing a Digital Forensic Investigation (DFI). Therefore, it is on this premise that this paper makes a contribution to the architectural design of a Cloud Forensic Readiness as-a-Service (CFRaaS) that uses a Non-Malicious Botnet (NMB) solution as a forensic agent. The authors argue that the architectural design of a CFRaaS is an important aspect, which brings out the requirements that are needed in order for the cloud to be forensically ready for digital investigations when a modified NMB acting as an Agent-Based Solution (ABS) is used. To support this claim, the authors have identified important dependencies and indicators that will provide a synergistic relationship while coming up with CFRaaS design decisions. The main objective of this paper is to present the requirements, design and implementation for achieving DFR in the cloud using a CFRaaS. This study complies with the ISO/IEC 27043: 2015 international standard which presents guidelines for Information Technology, Security Techniques and Incident Investigation Principles and Processes. The result of the study has indicated that it is possible to achieve DFR in the cloud environment using a botnet with modified functionalities.

Methicillin-resistant coagulase-negative staphylococci (MRCoNS) have recently emerged as a significant cause of bovine mastitis worldwide. Here we describe the isolation of MRCoNS from cases of bovine mastitis from a single dairy farm in Australia. Fourteen CoNS isolates were identified as MRCoNS on the basis of having an oxacillin MIC of ≥0.5 μg/mL. The isolates were speciated as S. chromogenes (n = 1) S. fleurettii (n = 1), S. haemolyticus (n = 2), S. sciuri (n = 5), S. simulans (n = 1) S. succinus (n = 2) and S. xylosus (n = 2). Five of the isolates (S. fleuretti, S. haemolyticus S. sciuri and two S. succinus) were mecA-positive. We also detected a previously described S. sciuri mecA homolog in four oxacillin-resistant S. sciuri isolates. The remainder of the putative MRCoNS did not contain any mecA-related resistance determinants in their genomes. Comparative genomic analysis of three previously published S. sciuri isolates, from humans, a squirrel and a cereal crop (rice), and a representative isolate from our study demonstrated clustering and a high degree of genetic homogeneity (>95%), suggesting S. sciuri has low host specificity. In conclusion, CoNS, in particular S. sciuri, may act as a reservoir for SCCmec elements that can easily be spread between different host species by direct cross-infection.

The spread of multidrug resistance among bacterial pathogens poses a serious threat to public health worldwide. Recent approaches towards combating antimicrobial resistance include repurposing old compounds with known safety and development pathways as new antibacterial classes with novel mechanisms of action. Here we show that an analog of the anticoccidial drug robenidine (4,6-bis(2-((E)-4-methylbenzylidene)hydrazinyl)pyrimidin-2-amine; NCL195) displays potent bactericidal activity against Streptococcus pneumoniae and Staphylococcus aureus by disrupting the cell membrane potential. NCL195 was less cytotoxic to mammalian cell lines than the parent compound, showed low metabolic degradation rates by human and mouse liver microsomes, and exhibited high plasma concentration and low plasma clearance rates in mice. NCL195 was bactericidal against Acinetobacter spp and Neisseria meningitidis and also demonstrated potent activity against A. baumannii, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae and Enterobacter spp. in the presence of sub-inhibitory concentrations of ethylenediaminetetra-acetic acid (EDTA) and polymyxin B. These findings demonstrate that NCL195 represents a new chemical lead for further medicinal chemistry and pharmaceutical development to enhance potency, solubility and selectivity against serious bacterial pathogens.

The crisis of antimicrobial resistance (AMR) is one of the most serious issues facing us today. The scale of the problem is illustrated by the recent commitment of Heads of State at the UN to coordinate efforts to curb the spread of AMR infections. In this review, we explore the biochemistry behind the headlines of a few stories that were recently published in the public media. We focus on examples from three different issues related to AMR: (i) hospital-acquired infections, (ii) the spread of resistance through animals and/or the environment and (iii) the role of antimicrobial soaps and other products containing disinfectants in the dissemination of AMR. Although these stories stem from three very different settings, the underlying message in all of them is the same: there is a direct relationship between the use of antimicrobials and the development of resistance. In addition, one type of antimicrobial could select for cross-resistance to another type and/or for multidrug resistance. Therefore, we argue the case for increased stewardship to not only cover clinical use of antibiotics, but also the use of antimicrobials in agriculture and stewardship of our crucially important biocides such as chlorhexidine.

© 2016 Elsevier B.V. Four mercury (Hg) contaminated soils with different pH (7.6, 8.5, 4.2 and 7.02) and total organic carbon contents (2.1, 2.2, 4 and 0.9%) were subjected to bioremediation utilizing a Hg volatilizing bacterial strain Sphingobium SA2 and nutrient amendment. In a field with ~ 280 mg/kg Hg, 60% of Hg was removed by bio-augmentation in 7 days, and the removal was improved when nutrients were added. Whereas in artificially spiked soils, with ~ 100 mg/kg Hg, removal due to bio-augmentation was 33 to 48% in 14 days. In the field contaminated soil, nutrient amendment alone without bio-augmentation removed 50% of Hg in 28 days. Nutrient amendment also had an impact on Hg remediation in the spiked soils, but the best results were obtained when the strain and nutrients both were applied. The development of longer root lengths from lettuce and cucumber seeds grown in the remediated soils confirmed that the soil quality improved after bioremediation. This study clearly demonstrates the potential of Hg-reducing bacteria in remediation of Hg-contaminated soils. However, it is desirable to trap the volatilized Hg for enhanced bioremediation.

The spread of multidrug resistance among bacterial pathogens poses a serious threat to public health worldwide. Recent approaches towards combating antimicrobial resistance include repurposing old compounds with known safety and development pathways as new antibacterial classes with novel mechanisms of action. Here we show that an analog of the anticoccidial drug robenidine (4,6-bis(2-((E)-4-methylbenzylidene)hydrazinyl)pyrimidin-2-amine; NCL195) displays potent bactericidal activity against Streptococcus pneumoniae and Staphylococcus aureus by disrupting the cell membrane potential. NCL195 was less cytotoxic to mammalian cell lines than the parent compound, showed low metabolic degradation rates by human and mouse liver microsomes, and exhibited high plasma concentration and low plasma clearance rates in mice. NCL195 was bactericidal against Acinetobacter spp and Neisseria meningitidis and also demonstrated potent activity against A. baumannii, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae and Enterobacter spp. in the presence of sub-inhibitory concentrations of ethylenediaminetetra-acetic acid (EDTA) and polymyxin B. These findings demonstrate that NCL195 represents a new chemical lead for further medicinal chemistry and pharmaceutical development to enhance potency, solubility and selectivity against serious bacterial pathogens.

The required cyclone underflow volume in tailings classification is usually relatively easily obtained for valley fills with low wall strength to basin area ratios and where at least 30% of the tailings particles in the feed are coarser than 75 microns. Underflow with no more than 15% passing 75 microns can be consistently generated by setting the cyclones to a cut at a point well above 75 microns. However, when the feed contains less than 20% coarser than 75 microns, the split to underflow meeting the required specification can be as low as 7%-10% and the volume requirements can become a constraint. Previous papers describing the optimisation of cyclones for the Kareerand and Brakpan gold tailings facilities in South Africa concluded that the variability and fine nature of the tailings made it difficult to meet the specifications. Additional tests were carried out to establish whether the cyclones could be better controlled by adjusting feed, underflow and overflow conditions dynamically and by changing spigot and vortex finder sizes. The results showed that variations in feed particle size distribution, pressure and density had a negative effect on operations and that reducing the variability will improve the split to the underflow by up to 3% and improve the stacking angle to 1:5. For a given solids concentration, yield stress increased as the percent passing 75 microns increased, with the rate of increase becoming significant above a solids concentration of 68%. The split to underflow can be increased by reducing the cyclone cut point to increase the percent passing 75 microns in the underflow by up to 25%, but this leads to a reduction in yield stress and in stacking angle. To maintain the stacking angle the solids concentration must be increased, but this is not possible without reducing mass split. The permeability of underflow with no more than 15% passing 75 microns was around 5 x 10(-5) m/s and the permeability of the overflow was 10(-7) to 10(-8) m/s, sat, The required cyclone underflow volume in tailings classification is usually relatively easily obtained for valley fills with low wall strength to basin area ratios and where at least 30% of the tailings particles in the feed are coarser than 75 microns. Underflow with no more than 15% passing 75 microns can be consistently generated by setting the cyclones to a cut at a point well above 75 microns. However, when the feed contains less than 20% coarser than 75 microns, the split to underflow meeting the required specification can be as low as 7%-10% and the volume requirements can become a constraint. Previous papers describing the optimisation of cyclones for the Kareerand and Brakpan gold tailings facilities in South Africa concluded that the variability and fine nature of the tailings made it difficult to meet the specifications. Additional tests were carried out to establish whether the cyclones could be better controlled by adjusting feed, underflow and overflow conditions dynamically and by changing spigot and vortex finder sizes. The results showed that variations in feed particle size distribution, pressure and density had a negative effect on operations and that reducing the variability will improve the split to the underflow by up to 3% and improve the stacking angle to 1:5. For a given solids concentration, yield stress increased as the percent passing 75 microns increased, with the rate of increase becoming significant above a solids concentration of 68%. The split to underflow can be increased by reducing the cyclone cut point to increase the percent passing 75 microns in the underflow by up to 25%, but this leads to a reduction in yield stress and in stacking angle. To maintain the stacking angle the solids concentration must be increased, but this is not possible without reducing mass split. The permeability of underflow with no more than 15% passing 75 microns was around 5 x 10(-5) m/s and the permeability of the overflow was 10(-7) to 10(-8) m/s, sat

English: Cryptolepis R.Br. (Apocynaceae, Periplocoideae) was taxonomically revised. Detailed descriptions of macro and micro-morphology, palynology, geographic distribution and ecological characteristics were presented. An identification key to the species was compiled and the nomenclature of all species was revised while all available type material was studied and lectotypes and neotypes were designated where necessary. Molecular phylogenetic analyses, based on the gene regions ITS, trnD–T and trnT–F, of representative species of 28 periplocoid genera and 22 Cryptolepis species were presented and the monophyly of Cryptolepis was evaluated. Historically a total of 81 species names and four subspecies names were published for Cryptolepis. However, a large number of species names were later placed in synonymy or transferred to other genera, while several new combinations were published. This resulted in a total of 29 accepted Cryptolepis species at the commencement of this study. Three new species, C. ibayana, C. thulinii and C. villosa, resulted from this study and the latter two were described in this thesis. One species, C. producta, was synonymised with C. oblongifolia. Cryptolepis, therefore, comprises a total of 31 species at present. In terms of species diversity, distribution and potential pharmaceutical and economic value, Cryptolepis is one of the most significant genera in the Periplocoideae. Cryptolepis grows throughout sub-Saharan Africa, the southern parts of Yemen, the island archipelago of Socotra, and southern Asia ranging from India to southern China, Taiwan, the Philippines and Indonesia. Most of the species grow in tropical forests or savannah, but 13 species are also adapted to arid environments. The majority of Cryptolepis species are concentrated in four centres of diversity along the east coast of Africa and on Socotra. These hotspots are associated with both arid and forest refugia in areas which have been regarded as local centres of endemism, Afrikaans: Cryptolepis R.Br. (Apocynaceae, Periplocoideae) is taksonomies hersien. Volledige beskrywings van die makro- en mikromorfologie, palinologie, geografiese verspreiding en ekologiese eienskappe is aangebied. 'n Uitkenningsleutel tot die spesies is opgestel, die nomenklatuur van al die spesies is hersien, terwyl alle beskikbare tipemateriaal bestudeer is en lekto- en neotipes is, waar nodig, aangewys. Molekulêre filogenetiese ontledings, gebaseer op die geenstreke ITS, trnD–T en trnT–F, van verteenwoordigende spesies van 28 periplokoide genusse en 22 Cryptolepis spesies is in die ondersoek ingesluit, en die monofilie van Cryptolepis is beoordeel. Histories is 'n totaal van 81 spesies en vier subspesies name vir Cryptolepis gepubliseer. 'n Groot aantal van hierdie spesiesname is egter later in sinonomie geplaas of na ander genusse oorgeplaas, terwyl 'n aantal nuwe kombinasies gepubliseer is. Met die aanvang van die huidige studie was daar dus 'n totaal van 29 erkende spesies in Cryptolepis. 'n Verdere drie nuwe spesies, C. ibayana, C. thulinii en C. villosa, is die resultaat van hierdie studie, waarvan die laasgenoemde twee in hierdie proefskrif beskryf is. Een spesie, C. producta, is in sinonomie met C. oblongifolia geplaas. Gevolglik sluit Cryptolepis tans 'n totaal van 31 spesies in. In terme van spesieverskeidenheid, verspreiding en potensiële farmaseutiese en ekonomiese belangrikheid is Cryptolepis een van die belangrikste genusse in die Periplocoideae. Cryptolepis kom dwarsdeur Afrika suid van die Sahara voor, maar ook in die suidelike deel van Jemen, in die Socotra eilandargipel en in suidelike Asië vanaf Indië tot suidelike Sjina, Taiwan, die Filippyne en Indonesië. Die spesies groei hoofsaaklik in tropiese woude of in savanna, maar 13 spesies word in droë omgewings aangetref. Die meeste Cryptolepis spesies is in vier diversiteitsentrums langs die ooskus van Afrika en op Socotra gekonsentreer. Hierdie brandpunte word met beide droë- en woudtoevlugniss

The concept of an Ephemerizer system has been introduced in earlier works as a mechanism to ensure that a file deleted from the persistent storage remains unrecoverable. The principle involved storing the data in an encrypted form in the user’s machine and the key to decrypt the data in a physically separate machine. However the schemes proposed so far do not provide support for fine-grained user settings on the lifetime of the data nor support any mechanism to check the integrity of the system that is using the secret data. In addition we report the presence of a vulnerability in one version of the proposed scheme that can be exploited by an attacker to nullify the ephemeral nature of the keys. We propose and discuss in detail an alternate Identity Based cryptosystem powered scheme that overcomes the identified limitations of the original system.

English: The aims of this study were to survey, classify, describe and ecologically interpret the natural plant communities of the University of the Free State campus in Bloemfontein. A further aim was to apply the urban biotope mapping technique to the campus so that ecological information may be availed to decision makers at the University in an easily accessible format. The phytosociological study was based on Braun-Blanquet procedures. A total of 222 reléves were classified using TURBOVEG, TWINSPAN and MEGATAB. Ordination using the DECORANA ordination algorithm was also applied to the floristic data in order to determine the relationship between the vegetation units and environmental variables. The vegetation was classified into 5 Major Grassland Communities and 2 Major Wetland Communities. All the vegetation units and sub-units were ecologically interpreted and described. Biotope mapping was conducted on the campus using a German technique that has been used in the city of Potchefstroom after being customized to South African conditions. The resultant biotope map showed that most of the space on the campus is taken up by 3 biotope types, namely the built-up area with its intensively managed lawns and gardens and planted trees mainly on the eastern side of the campus, the extensively managed open spaces (natural grassland) mainly in the middle and to the west and the intensively managed sports fields. This study also contributes to the building up of scientific knowledge about the Grassland Biome. Recommendations are made as to how the vegetation on the campus and in other increasingly urbanizing areas of the Grassland Biome may be managed in a manner that is ecologically sound and that meets amenity needs as well., Afrikaans: Die doel van hierdie studie was om die natuurlike plant gemeenskappe van die Universiteit van die Vrystaat se hoofkampus in Bloemfontein te ondersoek, te klassifiseer, te beskryf en ekologies te interpreteer. vii ‘n Verdere doel was om die stedelike biotoop karteringsmetode op die kampus toe te pas ten einde ekologiese inligting vir besluitnemers op die kampus, in ‘n maklik verstaanbare vorm, beskikbaar te stel. Die fitososiologiese studie was gebaseer op Braun-Blanquet prosedures. ‘n Total van 222 reléves is deur die klassifikasie gebruik deur van TURBOVEG, TWINSPAN en MEGATAB gebruik te maak. Ordening deur middel van die DECORANA ordeningsalgoritme was ook op die floristiese data toegepas om te bepaal wat die verwantskappe tussen die plantgemeenskappe en die betrokke omgewingsfaktore, is. Die plantegroei is in 5 Hoof Grasveld-gemeenskappe en 2 Hoof Vleiland-gemeenskappe geklassifiseer. Al die eenhede en sub-eenhede is ekologies geïnterpreteer en beskryf. Biotoop-kartering van die UV kampus is gedoen deur middel van ‘n gewysigde Duitse metode. Hierdie metode is aangepas vir Suid Afrikaanse toestande en is vir die eerste keer in Potchefstroom gebruik. Die biotoop-kaart van die UV-kampus toon dat meeste van die ruimte op die kampus deur drie biotoop-tipes beslaan word. Hulle is beboude gebied met tuine, aangeplante bome en grasperke (oos-kampus), uitgebreide oop areas wat deur natuurlike veld beslaan word, ook intensief-bestuurde sportvelde (weskampus). Hierdie studie dra by tot die steeds uitbreidende wetenskaplike kennis van die Grasveld Bioom. Aanbevelings word gemaak om die natuurlike plantegroei op die kampus op ‘n ekologies verantwoordelike manier te bestuur en om die intrinsieke waarde van die veld te behou.

A taxonomic revision of Cryptolepis R.Br. (Apocynaceae, Periplocoideae) in southern Africa is presented. This revision comprises investigations into the micromorphology of pollen, translators, leaf anatomy, leaf epidermal surfaces and seed coat surfaces; macro-morphology of the plant parts; nomenclature, geographical distribution and ecological characteristics of the six species indigenous to southern Africa. The investigations resulted in descriptions with appropriate nomenclature and the compilation of an identification key for the six species. All available type specimens related to Cryptolepis in southern Africa were studied. Where holotype specimens could not be located lectotypes were designated from available isotypes or syntypes. Where no isotypes or syntypes could be located, neotypes were declared. In cases where only syntypes had been given by authors of species names, lectotypes were declared. Cryptolepis is widely distributed throughout the northern parts of southern Africa, with the largest concentration of species in the north-east of the region. Some species, such as C. oblongifolia, are common, while others have very restricted distribution ranges. C. delagoensis, for instance, is known from only six localities in southern Africa. Only C. decidua occurs in the desert and semi-desert habitats in the north-west of southern Africa, while the other five species inhabit savannah, sand forest, riverine -, afromontane - and coastal vegetation in the eastern parts of the region. In southern Africa Cryptolepis consists of slender climbers, occasionally small suffrutices or branching shrubs with white latex and interpetiolar ridges with dentate colleters. Leaves are opposite, decussate or rarely fascicled. A combination of leaf anatomy and leaf surface characteristics proved to be taxonomically useful for distinguishing the southern African species. The fruit consists of paired follicles. Seeds of Cryptolepis are adapted to anemochoric dispersal through a com

Two new species, Cryptolepis nugaalensis and Cryptolepis somaliensis are described. Both were discovered in and environment in Somalia. Both belong to a unique group of xerophytic, mostly shrub-like species in the Horn of Africa, island of Socotra and southern Arabia, isolated from the rest of the genus.