Wireless Networks is a very growing market. However, the security measures are not strong enough; the WEP security protocol is flawed. The 802.11 Task Group I is working on new security measures in order to strengthen the access control of users, the privacy and the integrity of data. We will describe the WEP flaws and the new security measures of 802.11 Task Group I. Finally, we will propose a new architecture to improve user identification for the wireless network of our department.

Student Number : 8805489T - MA research report - School of Human and Community Development - Faculty of Humanities / A casual scan of workplace based mental health services in South Africa reveals a developing tendency and trend towards the outsourcing of this service. Most companies that previously boosted relatively huge integrated and comprehensive workplace mental health services have ceased offering these services internally in favour of sourcing them from external service providers. Most occupational social workers who previously worked in these departments are now part of the outsourced services. Occupational social work theory advocates for practitioners to go beyond focusing on the individual by also seeking to impact on the environment and the community in the quest to serve the needs of their clients. Some services, particularly if the practitioner seeks to change the host organisation, are easier to render when the practitioner is within the organisation. The present study investigated, using robust statistical methods, firstly, the desirability of comprehensiveness and integration in workplace mental health services, and, secondly, whether observed levels of comprehensiveness and integration in service delivery in a single organisation that uses outsourced workplace mental health services are in line with desired levels. The research results indicate that host organisations desire more comprehensiveness and integration in workplace mental health services than is currently observed from an outsourced mental health service.

<p>This dissertation investigates the linguistic features of engagement in spoken academic online and face-to-face instruction in mathematics on two platforms: Khan Academy and MIT OpenCourseWare. In particular, the study analyses involvement features (personal pronouns and deixis) and interactional features (response elicitors, direct hypothetical reported speech). Using corpus linguistics methodology and register analysis framework (Biber &Conrad, 2009), I investigated normed frequency of occurrence for these features and multi-word expressions which contain them to reveal patterns of use. Additionally, I investigated the function of these features in concordance lines to reveal their use to engage audience in the learning process. The findings of this study suggests that Khan Academy instruction in mathematics relies on using conversational and academic spoken features similar to those found in the MIT lecture corpus, including frequent use of personal pronouns (especially <i>we)</i>, and response elicitors (<i>right?)</i>. The format of online video instruction also elicits more use of spatial deixis to draw attention to the elements on the virtual board. The findings of this exploratory study add to the growing literature on language used for educational purposes in online environments, especially the online academic spoken discourse.</p>

The Staphylococcus aureus two component system (TCS) sae governs expression of numerous virulence factors, including Eap (extracellular adherence protein), which in turn among other functions also mediates invasion of host cells. The sae TCS is encoded by the saePQRS operon, with saeS coding for the sensor histidine kinase (SaeS) and saeR encoding the response regulator (SaeR). The saeRS system is preceded by two additional open reading frames (ORFs), saeP and saeQ, which are predicted to encode a lipoprotein (SaeP) and a membrane protein (SaeQ), respectively. Earlier, we have shown that SDS-containing subinhibitory concentrations of biocides (Perform®) and SDS alone activate sae transcription and increase cellular invasiveness in S. aureus strain Newman. The effect is associated with an amino acid exchange in the N-terminus of SaeS (L18P), specific to strain Newman. In this work, the role of whether the two additional genes, saePQ coding for the accessory proteins SaeP and SaeQ, respectively, are involved in SDS-mediated saeRS was investigated. It could demonstrated that the lack of the SaeP protein resulted in an increased saeRS transcription without SDS stress in both SaeSL/P variants, while the SDS effect was less pronounced on sae and eap expression compared to the Newman wildtype, suggesting that the SaeP protein represses the sae system. Also, SDS-mediated inductions of sae and eap transcription along with enhanced invasion were found to be dependent on presence of the SaeSP variant in Newman wildtype. On the other hand, the study also shows that the saePQ region of the sae operon is required for fully functional two-component system saeRS under normal growth conditions, but it is not involved in SDS-mediated activation of the saeS signaling and sae-target class I gene, eap. In the second approach, the study investigates whether SDS-induced sae expression and host cell invasion is common among S. aureus strains not carrying the (L18P) point mutation. To demonstrate this strain Newman, its isogenic saeS mutants, and various S. aureus isolates were analysed for sae, eap expression and cellular invasiveness. Among the strains tested, SDS exposure resulted only in an increase of sae transcription, Eap production and cellular invasiveness in strain Newman wild type and MRSA strain ST239-635/93R, the latter without an increase in Eap. Interestingly, the epidemic community-associated MRSA strain, USA300 LAC showed a biphasic response in sae transcription at different growth stages, which, however, was not accompanied by increased invasiveness. All other clinical isolates investigated displayed a decrease of the parameters tested. While in strain Newman the SDS effect was due to the saeSP allele, this was not the case in strain ST239-635/93R and the biphasic USA300 strains. Also, increased invasiveness of ST239-635/93R was found to be independent of Eap production. Furthermore, to investigate the global effect of SDS on sae target gene expression, strain Newman wild-type and Newman ∆sae were treated with SDS and analyzed for their transcription profiles of sae target genes using microarray assays. We could show that subinhibitory concentrations of SDS upregulate and downregulate gene expression of several signaling pathways involved in biosynthetic, metabolic pathways as well as virulence, host cell adherence, stress reponse and many hypothetical proteins. In summary, the study sheds light on the role of the upstream region saePQ in SDS-mediated saeRS and eap expression during S. aureus SDS stress. Most importantly, the study also shows that subinhibitory SDS concentrations have pronounced strain-dependent effects on sae transcription and subsequent host cell invasion in S. aureus, with the latter likely to be mediated in some strains by other factors than the known invasin Eap and FnBP proteins. Moreover, there seems to exist more than the saeSP-mediated mechanism for SDS-induced sae transcription in clinical S. aureus isolates. These results help to further understand and clarify virulence and pathogenesis mechanisms and their regulation in S. aureus. / Das Zwei Komponenten-Systems (TCS) Sae in S. aureus reguliert die Expression einer Vielzahl von Virulenzfaktoren, dazu gehört unter anderem das extrazelluläre Adhärenzprotein Eap, welches neben weiteren Funktionen, die Invasion in eukaryotische Wirtszellen vermittelt. Die Gene des sae TCS sind in einem Operon organisiert (saePQRS), wobei saeS für die sensorische Histidinkinase (SaeS) und saeR für den „Response Regulator“ (SaeR) kodieren. Diesen Genen sind zwei weitere Genabschnitte, saeP und saeQ, vorangestellt, wobei saeP vermutlich für ein Lipoprotein (SaeP) und saeQ für ein Membranprotein (RelQ) kodieren. In einer früheren Arbeit konnten wir zeigen, dass SDS-haltige Biozide (Perform©) unter sub- inhibitorischen Konzentrationen, sowie reines SDS, die sae Transkription aktiviert und dadurch zu einer erhöhten Invasion des S. aureus Stamms Newman in Wirtszellen führt. Dieser Effekt ist assoziiert mit einem spezifischen Aminosäureaustausch im N-terminus von SaeS (L18P) des Stamm Newman. In dieser Arbeit soll nun die Beteiligung der zwei zusätzlichen Gene, saeP und saeQ, an der SDS vermittelten transkriptionellen Induktion von saeR/S untersucht werden. Es konnte gezeigt werden, dass ohne SaeP, die saeR/S Transkription in beiden SaeL/P Varianten erhöht war, wobei eine zusätzliche SDS Behandlung hierfür nicht notwendig war. Im Gegenteil, es zeigte sich, dass der SDS Effekt auf die sae und eap Expression in der saeP Mutante deutlich weniger ausgeprägt ist als im Wildtyp Stamm. Das läßt vermuten, dass das Lipoprotein SaeP repremierend auf das sae System einwirkt. Des Weiteren wurde festgestellt, dass die SDS vermittelte transkriptionelle Induktion von sae und eap, zusammen mit der erhöhten Invasion, abhängig vom vorhanden sein der SaeSP Variante im Newman Wildtyp Stamm ist. Die Arbeit zeigt, dass die saePQ Region wichtig ist für die vollständige Funktion des Zwei Komponenten Systems SaeRS unter normalen Wachstumsbedingungen. Jedoch ist diese Region nicht involviert in der Aktivierung von SaeS, mit SDS als Signalgeber, sowie der darauffolgenden Aktivierung des sae Zielgens eap. In einem zweiten Ansatz wurde untersucht, ob die SDS induzierte sae Expression und Wirtszellinvasion auch häufig in S. aureus Stämmen auftritt, welche keine (L18P) Punktmutation besitzen. Dafür wurde Stamm Newman, die isogene saeS Mutante und verschiedene S. aureus Klinikisolate auf ihre sae, eap Expression, sowie zelluläre Invasionsfähigkeit hin analysiert. Von den getesteten Stämmen reagiert nur Wildtyp Stamm Newman und ein MRSA Stamm ST239-635/93R mit gesteigerter sae Transkription, Eap Produktion und zellulärer Invasion. Der MRSA Stamm jedoch ohne erhöhte Eap Produktion. Interessanterweise zeigt der „community- associated“ MRSA Stamm USA300 LAC eine biphasische sae Transkription in verschiedenen Wachstumsphasen, welche jedoch nicht einhergeht mit erhöhter Invasion. Alle anderen Klinikisolate zeigten abnehmende Tendenzen in den getesteten Parametern. Während im Stamm Newman der SDS Effekt auf das saeSP Allel zurückzuführen ist, gilt dies nicht für den Stamm ST239-635/93R, sowie den biphasischen Stamm USA300. Außerdem konnte gezeigt werden, dass die erhöhte Invasion des Stamms ST239-635/93R unabhängig von seiner Eap Produktion ist. Des Weiteren zeigten wir den globalen Effekt von SDS auf die sae Zielgenexpression. Dafür behandelten wir Wildtyp Stamm Newman mit SDS und analysierten die Transkription der sae Zielgene mittels Microarray Analyse. Wir konnten zeigen, dass subinhibitorische SDS Konzentrationen, induzierende als auch repremierende Auswirkungen auf die Genexpression haben. Dabei sind Gene betroffen, die involviert sind in verschiedene Signalwege, Biosynthese/Metabolismus als auch in Virulenz, Wirtzelladhärenz und Stressantwort. Zusammenfassend gibt die Arbeit Aufschluss über die Rolle der „upstream“ Region saePQ hinsichtlich der SDS-abhängigen saeRS und eap Expression in S. aureus. Am wichtigsten ist hierbei die Erkenntnis, das subinhibitorische SDS Konzentrationen einen deutlichen stammabhängigen Effekt auf die sae Transkription und daraus folgernd auf die Wirtszellinvasion von S. aureus haben. Letzteres wird vermutlich in manchen Stämmen durch andere Faktoren als die bekannten Invasinproteine Eap und FnBP vermittelt. Außerdem scheint es in den klinischen S. aureus Isolaten mehr als nur den saeSP abhängigen Mechanismus der sae Induktion durch SDS zu geben. Diese Ergebnisse helfen uns die Virulenz und pathogenen Mechanismen als auch deren Regulation in S. aureus zu verstehen. Die Beobachtungen tragen zu unserem Verständnis bei, wie das sae System Signale der Umgebung detektieren kann. Dies ist bis jetzt eine Fragestellung mit vielen Unbekannten.

For many students, listening to academic lectures is one of the hardest listening skills (Lebauer, 1988). There are various possible reasons for this: the jargon and specialised words of the field that are used; also the language that is used is often at a more formal level; the lecture situation which is unidirectional with the listener having little role to play, and no control of the oral message; the expectations that the listener is assumed to have in listening to lectures which depends on many factors such as attitude, motivation, linguistic knowledge and world experience. Trying to find an answer to where difficulties lie is the purpose of this study, with the focus on the type of problems that post-graduate non-native students of English might have had during their study in a native English academic environment. Chapter one presents the purpose and significance of study, and deals with a few problems in the history of the teaching of listening in Vietnam. Chapter two looks at the different developments in understanding the listening processes in general and listening to lectures in particular. Chapter three studies difficulties that non-native speakers of English may face in lecture listening. Chapter four mentions some of the recommendations that the study implies.

<p>This thesis investigates how Ericsson AB should do to achieve fast and secure handover when roaming in a WLAN. It also provides a security analysis of the system that the wireless access point is part of. The reason for this is that Ericsson is selling an access point called the ABS 2200 aimed at the public hotspot market. </p><p>The premise was that they wanted a standardized way of handling the roaming issue. At the outset the 802.11F standard looked like a good alternative (in fact the only standardized alternative). Towards last stages of the work though, it was discovered that the 802.11F standard is no longer supported by IEEE. </p><p>Despite this fact, the conclusion is that secure and fast roaming can be attained if 802.11F is combined with the security standard 802.11i. </p><p>The security analysis concludes that Denial Of Service is a major threat to WLAN hotspots. It also points out the link between the access point and authentication server is the weakest link in the system. The recommendation is that this link receives an additional layer of protection through IPsec withESP. The algorithm recommendations for ESP are AES for confidentiality and SHA-1 for integrity. </p><p>This thesis can also be used as a primer on security in WLAN and contains an extensive glossary making it useful as a reference when reading 802.11 standards.</p>

This post-use evaluation research aims to investigate the appropriacy of academic writing materials to contextual needs, and to investigate the essential considerations concerning these materials. This case study was conducted with the participation of program designers, teachers, and students at three universities in Hungary, Turkey, and Oman. A unique checklist was developed to evaluate the materials. The data collection process consisted of questionnaires and interviews. The results concur with findings in the literature regarding the benefits of using computer-mediated communication in the writing class, the need to combine process and product pedagogies, the necessity of having discipline-specific themes, and the need to provide students with more guidelines and input. Interestingly, contrary to the literature, the students do not seem to benefit from peer feedback / they value teacher feedback more. Furthermore, despite their increasing role in writing, there are few collaborative writing activities in these materials. The quantitative and the qualitative data also demonstrate that the program designers and the teachers consider in-house writing materials more appropriate than global materials, since they were developed in view of the learning context and the specific requirements. However, neither global nor in-house materials are regarded as motivating and attracting for the students. There are relatively new areas for further research as a result of these findings: the role of free writing in EAP and the ways to manage mixed language levels of the students. All these findings are expected to provide insights to researchers and practitioners in the fields of writing and materials evaluation.

This post-use evaluation research aims to investigate the appropriacy of academic writing materials to contextual needs, and to investigate the essential considerations concerning these materials. This case study was conducted with the participation of program designers, teachers, and students at three universities in Hungary, Turkey, and Oman. A unique checklist was developed to evaluate the materials. The data collection process consisted of questionnaires and interviews. The results concur with findings in the literature regarding the benefits of using computer-mediated communication in the writing class, the need to combine process and product pedagogies, the necessity of having discipline-specific themes, and the need to provide students with more guidelines and input. Interestingly, contrary to the literature, the students do not seem to benefit from peer feedback / they value teacher feedback more. Furthermore, despite their increasing role in writing, there are few collaborative writing activities in these materials. The quantitative and the qualitative data also demonstrate that the program designers and the teachers consider in-house writing materials more appropriate than global materials, since they were developed in view of the learning context and the specific requirements. However, neither global nor in-house materials are regarded as motivating and attracting for the students. There are relatively new areas for further research as a result of these findings: the role of free writing in EAP and the ways to manage mixed language levels of the students. All these findings are expected to provide insights to researchers and practitioners in the fields of writing and materials evaluation.

<p>This study explores second and third year students' and teachers‟ views on factors that hinder or facilitate the mastery of English for Academic Purposes (EAP) in the Science and Engineering Technology Higher Institutions of learning in Rwanda (KIST) and seeks to establish the extent to which the current programme meets the needs of the students. This is done by highlighting a whole range of teacher and student perspectives on the EAP programme. Two key requirements invite students to write their academic assignments in the form of research proposals and research project reports. In order to help them perform well in their field subjects, KIST introduced a department of English with a General English Programme under the umbrella of the then School of Language Studies (SORAS) in 1997. The department‟s first assigned mission was to teach English to students in all departments in a bid to support and encourage them to cope with their field specific courses which are taught in English. Rwanda‟s National Council for Higher Education (2007), on language teaching and learning, states that the trio, that is Kinyarwanda (the Mother Tongue and national language) and English and French (as foreign languages), should be taught at primary, secondary and higher education levels in order to reconcile the divide between Rwandan returnees (who had lived abroad for many decades) and locals. It is in this context that KIST, one of the institutions of higher learning, adopted the bilingual policy to cater to students‟ needs to learn both French and English as media of academic communication. However, after Rwanda‟s integration into the East African Community and the Commonwealth, English has been officially adopted as the medium of instruction in all schools and higher institutions of education. That is why there was a sudden language shift in 2006 from French to English as a medium of instruction at KIST. French and Kinyarwanda are now merely taught as subjects. The motive behind the move was to cater for Rwanda‟s needs to fully participate in the economic community of East African Community in general and in the global economy in particular. The move drastically affected students‟ ability to read and write English in their respective disciplines. The move also affected lecturers of other speciality areas. To avert the obvious challenges emanating from this sudden shift in language policy, the Institute introduced the English for Specific Purposes (ESP) and English for Academic Purposes (EAP) programmes under the then KIST School of Language Studies (SOLAS) and the KIST Language Centre. However, appropriate instructional materials for such courses have not been easily available. Given this situation, English teachers have had to create their own materials rather than the existing generalised and pre-packaged language teaching materials. As a result, students‟ specific needs for induction into a scientific writing community at tertiary level have rarely been met. It is against this background that the study seeks to investigate factors that are facilitating and the mastery of EAP. The study operates on post-colonial/post-structuralist theoretical perspectives. These were founded on the analytical framework that is guided by thematic and/or conceptual underpinnings of language policy in the post-colonial Africa. Thus, English Language Teaching (ELT), developed into English as a second and additional language that is multi-semiotic and multi-modality in EAP and science genres, focusing mostly on its academic literacy, identity, ideology, power and agency, as well as its investment in language teaching and learning and the scientific community practice. Using a combination of ethnographic principles/practices like participants‟ observations, oneto- one interviews, focus group discussions and documentary review in data collection, the study utilises thematic/conceptual analysis to draw its conclusions. Drawing from the above conceptual perspectives, therefore, as well as from the methodological approach, this thesis emphasises the fact that the inability of students to successfully master EAP is caused by various factors, including the choice of English language learning materials. Contradictory approaches to language learning and to academic literacy practices create further challenges to the Rwandan students‟ advancement in English mastery. These same practices also serve to limit the students‟ ability to learn this language and complicate their access to local and global cultural exposure that is necessary for their socio-economic development of Rwanda. The study also reveals lack of appropriate discursive competence and multi-semiotic repertoires as some of the major factors inhibiting students‟ academic progress. This is partly explained by the nature of the English language learning and teaching materials that is in use which neither provides general nor disciplinary specific academic and learning opportunities in English. Similarly, a range of structural and professional constraints on &bdquo / agency‟ exists for teachers of English in Rwanda as an additional language to the students, including lack of induction into scientific discourses or the EAP community of language practice. The overall lack of power and agency by teachers also contributes to constraints and constrictions in English language learning practices for these students in Rwanda. The study, however, observes that this situation is not only peculiar to KIST, as it is also common in almost all tertiary institutions in Rwanda. Specific recommendations are made in the study to improve the quality of English language learning and teaching in general and EAP in particular at KIST as an institution of higher learning, through the establishment of a clearer language policy and training opportunities for staff to update and develop required language skills in EAP, especially with regards to writing skills in sciences and engineering. The government of Rwanda, under the umbrella of Rwanda Education Board (REB) and the contribution of English language experts at the Institute, should provide a clearer direction of the language policy and curriculum that addresses Rwandan students‟ specific needs. KIST, as an institution of higher learning, should value and facilitate the teaching and learning of English in general and the teaching of EAP in particular, bearing in mind its assigned mission. The management of the Institute should encourage interaction between EAP and subject area lecturers to discuss and agree upon, text types to be used by EAP lecturers in teaching. KIST management should also provide room for regular interactions with English lecturers to listen to their views and offer them further language training opportunities in order to update and develop the required skills in EAP, especially with regards to writing skills in science and engineering.</p>

The purpose of this study is to investigate the efficiencies of bioremediation of sandy beach contaminated by crude oil. In this study, we used two lab-scale tanks, tank-A and tank-B, to simulate a sandy beach contaminated by crude oil. In the experiments, we added the bioreagents and oleophilic fertilizers (Inipol EAP 22&#x00AE;) in order to enrich crude oil degradation of sandy beach. The crude oil was degraded by nature culture in tank-A, while the crude oil was degraded by the mixed culture of several pure strains¡]MO-1, KS-1, DS-4, PF-4, PH-2, B-1, TF and XY-2¡^. We divided the experiment into five stages in this study. In conclusion, we found that the oleophilic fertilizers could increase both of the growth rate of oil degradation bacteria and crude oil biodegradation rate. However, a part of the fertilizers might flow into the ocean due to idal current. The addition of mixed culture could help to improve the biodegradation rate of sandy beach contaminated by crude oil.