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Research paper thumbnail of Experimental Study of a Network Access Server for a public WLAN access network

andrew.cmu.edu

Wireless access networks have gained popularity due to the flexibility they allow to the users, w... more Wireless access networks have gained popularity due to the flexibility they allow to the users, who is able to move away from his or her desk while still being able to access information. Among the different Wireless LAN standards, the most widespread, by far, is IEEE 802.11. Public WLAN access networks are being set up in hotspots, i.e. areas expected to have high demand for bandwidth. Access to the Internet and to corporate networks is provided at these hotspots with limited coverage but high available bandwidth. Airports and hotels have often been the first targeted locations for these hotspots, but conference centres, cafes, and train stations will then follow. In the near future, any person who owns at least one access point and has a connection to the Internet can become a small operator and offer access to the Internet using these resources. Existing solutions for such WLAN access networks lack support for security, flexible accounting, mobility, multiaccess, roaming and user-friendly login. The aim of this Master's Thesis was to study if it was possible to solve these problems and how to integrate all this new functionality into existing public WLAN access networks by building and evaluating a prototype of a public WLAN access network. System requirements were defined, currently available solutions analysed and a prototype was built. Most of the functionality of the prototype is placed in the Network Access Server, which is the main element providing security, mobility, and accounting. Flexible accounting, improvements in security, an easy and fast way to login the user, a feedback module to provide information about the current session and integration of the RADIUS architecture with the Mobile IP distribution have all been implemented. We would like to thank our examiner, Professor Gerald Maguire Jr. for his invaluable answers to our questions and his assistance in the preparation of this manuscript. Special thanks, to our advisor George Liu for his advice and guidance during all the time working in the thesis. We would like to express also our most sincere thanks to Enrico Pelleta, for providing us with his IP-Login code, which saved us a lot of time. We also thank all the GNU community for creating great open software, especially the Dynamics, Netfilter, FreeSwan, Freeradius and mySQL teams; without their software this thesis would not have been possible. Thanks to R2M for providing us the opportunity to perform this thesis and to all the Elektrosmoggers for helpful input and interesting presentations. Finally and most specially thanks to our families and friends for supporting us all this time.

Research paper thumbnail of Insights from the inside: A view of botnet management from infiltration

Recent work has leveraged botnet infiltration techniques to track the activities of bots over tim... more Recent work has leveraged botnet infiltration techniques to track the activities of bots over time, particularly with regard to spam campaigns. Building on our previous success in reverseengineering C&C protocols, we have conducted a 4-month infiltration of the MegaD botnet, beginning in October 2009. Our infiltration provides us with constant feeds on MegaD's complex and evolving C&C architecture as well as its spam operations, and provides an opportunity to analyze the botmasters' operations. In particular, we collect significant evidence on the MegaD infrastructure being managed by multiple botmasters. Further, FireEye's attempt to shutdown MegaD on Nov. 6, 2009, which occurred during our infiltration, allows us to gain an inside view on the takedown and how MegaD not only survived it but bounced back with significantly greater vigor. In addition, we present new techniques for mining information about botnet C&C architecture: "Google hacking" to dig out MegaD C&C servers and "milking" C&C servers to extract not only the spectrum of commands sent to bots but the C&C's overall structure. The resulting overall picture then gives us insight into MegaD's management structure, its complex and evolving C&C architecture, and its ability to withstand takedown.

Research paper thumbnail of Complications of 5—Fluorouracil after trabeculectomy

Eye, 1991

Trabeculectomy has a very high success rate,I-3 however, certain ey es are known to be at high ri... more Trabeculectomy has a very high success rate,I-3 however, certain ey es are known to be at high risk of failure due to scarring of the conjunctival bleb. Such eyes include Repeat filtering surgery 21 Secondary glaucoma due to uveitis 11 Aphakia 4 Age <4U 3 African Race 3 Multiple indications 7 Correspondence to Roger A. Hitchings. Consultant Ophthalmologist. Glaucoma Unit, Moorfields Eye Hospital, City Road. London Eel v 2PD.

Research paper thumbnail of Microbiological diagnostic procedures for respiratory cystic fibrosis samples in Spain: towards standard of care practices

BMC Microbiology, 2014

Background: The microbiological procedures for cystic fibrosis (CF) samples of 17 participating S... more Background: The microbiological procedures for cystic fibrosis (CF) samples of 17 participating Spanish centers were examined to verify their compliance with current international and national guidelines and to implement the best standards of care for microbiology practices. A 47-item questionnaire covering different CF microbiology aspects was sent to participant laboratories. Telephone interviews were performed when necessary. Data about samples processing for bacteria, mycobacteria and fungi were collected. Results: Gene sequencing (71%), MALDI-TOF (59%) or both (94%) were available for most laboratories. Susceptibility testing was performed by automated microdilution systems (94%) and manual diffusion methods (59%). However, a low use of selective media for Staphylococcus aureus (59%) and Burkholderia cepacia complex (71%), and of epidemiological typing methods (41%) was reported. Conclusions: Most Spanish laboratories are in agreement with consensus guidelines for the processing of CF respiratory samples, but need to improve in the use of specific selective media and typing methods for epidemiologic studies.

Research paper thumbnail of Group B streptococcal meningitis in adults: report of twelve cases and review

Clinical infectious …, 1997

Group B streptococcus (GBS) is the leading etiologic agent of bacterial meningitis and sepsis dur... more Group B streptococcus (GBS) is the leading etiologic agent of bacterial meningitis and sepsis during the neonatal period, but it is an infrequent cause of meningitis in adults. We report 12 episodes of group B streptococcal meningitis in adults and review 52 cases reported in the literature. A total of 24 men and 40 women were included in the study; the mean age ({ SD) was 49.2 { 20.5 years (range, 17-89 years). All the patients had cerebrospinal fluid cultures positive for GBS. Eighty-six percent of the patients had comorbid conditions, 50% had a distant focus of infection, and blood cultures yielded GBS for 78.7%. The overall case-fatality rate was 34.4% (22 patients). Factors associated with a poor outcome were advanced mean age ({ SD) (61.5 { 17.4 years vs. 42.8 { 19.2 years; P Å .0003) and the presence of complications on admission (P Å .0001). Seven percent of survivors had neurological sequelae. Group B streptococcal meningitis in adults has become increasingly frequent in recent years; it tends to occur in patients with severe underlying conditions and is associated with a high casefatality rate. Factors associated with a poor prognosis are advanced age and the occurrence of neurological and extraneurological complications.

Research paper thumbnail of Experimental Study of a Network Access Server for a public WLAN access network

andrew.cmu.edu

Wireless access networks have gained popularity due to the flexibility they allow to the users, w... more Wireless access networks have gained popularity due to the flexibility they allow to the users, who is able to move away from his or her desk while still being able to access information. Among the different Wireless LAN standards, the most widespread, by far, is IEEE 802.11. Public WLAN access networks are being set up in hotspots, i.e. areas expected to have high demand for bandwidth. Access to the Internet and to corporate networks is provided at these hotspots with limited coverage but high available bandwidth. Airports and hotels have often been the first targeted locations for these hotspots, but conference centres, cafes, and train stations will then follow. In the near future, any person who owns at least one access point and has a connection to the Internet can become a small operator and offer access to the Internet using these resources. Existing solutions for such WLAN access networks lack support for security, flexible accounting, mobility, multiaccess, roaming and user-friendly login. The aim of this Master's Thesis was to study if it was possible to solve these problems and how to integrate all this new functionality into existing public WLAN access networks by building and evaluating a prototype of a public WLAN access network. System requirements were defined, currently available solutions analysed and a prototype was built. Most of the functionality of the prototype is placed in the Network Access Server, which is the main element providing security, mobility, and accounting. Flexible accounting, improvements in security, an easy and fast way to login the user, a feedback module to provide information about the current session and integration of the RADIUS architecture with the Mobile IP distribution have all been implemented. We would like to thank our examiner, Professor Gerald Maguire Jr. for his invaluable answers to our questions and his assistance in the preparation of this manuscript. Special thanks, to our advisor George Liu for his advice and guidance during all the time working in the thesis. We would like to express also our most sincere thanks to Enrico Pelleta, for providing us with his IP-Login code, which saved us a lot of time. We also thank all the GNU community for creating great open software, especially the Dynamics, Netfilter, FreeSwan, Freeradius and mySQL teams; without their software this thesis would not have been possible. Thanks to R2M for providing us the opportunity to perform this thesis and to all the Elektrosmoggers for helpful input and interesting presentations. Finally and most specially thanks to our families and friends for supporting us all this time.

Research paper thumbnail of Insights from the inside: A view of botnet management from infiltration

Recent work has leveraged botnet infiltration techniques to track the activities of bots over tim... more Recent work has leveraged botnet infiltration techniques to track the activities of bots over time, particularly with regard to spam campaigns. Building on our previous success in reverseengineering C&C protocols, we have conducted a 4-month infiltration of the MegaD botnet, beginning in October 2009. Our infiltration provides us with constant feeds on MegaD's complex and evolving C&C architecture as well as its spam operations, and provides an opportunity to analyze the botmasters' operations. In particular, we collect significant evidence on the MegaD infrastructure being managed by multiple botmasters. Further, FireEye's attempt to shutdown MegaD on Nov. 6, 2009, which occurred during our infiltration, allows us to gain an inside view on the takedown and how MegaD not only survived it but bounced back with significantly greater vigor. In addition, we present new techniques for mining information about botnet C&C architecture: "Google hacking" to dig out MegaD C&C servers and "milking" C&C servers to extract not only the spectrum of commands sent to bots but the C&C's overall structure. The resulting overall picture then gives us insight into MegaD's management structure, its complex and evolving C&C architecture, and its ability to withstand takedown.

Research paper thumbnail of Complications of 5—Fluorouracil after trabeculectomy

Eye, 1991

Trabeculectomy has a very high success rate,I-3 however, certain ey es are known to be at high ri... more Trabeculectomy has a very high success rate,I-3 however, certain ey es are known to be at high risk of failure due to scarring of the conjunctival bleb. Such eyes include Repeat filtering surgery 21 Secondary glaucoma due to uveitis 11 Aphakia 4 Age <4U 3 African Race 3 Multiple indications 7 Correspondence to Roger A. Hitchings. Consultant Ophthalmologist. Glaucoma Unit, Moorfields Eye Hospital, City Road. London Eel v 2PD.

Research paper thumbnail of Microbiological diagnostic procedures for respiratory cystic fibrosis samples in Spain: towards standard of care practices

BMC Microbiology, 2014

Background: The microbiological procedures for cystic fibrosis (CF) samples of 17 participating S... more Background: The microbiological procedures for cystic fibrosis (CF) samples of 17 participating Spanish centers were examined to verify their compliance with current international and national guidelines and to implement the best standards of care for microbiology practices. A 47-item questionnaire covering different CF microbiology aspects was sent to participant laboratories. Telephone interviews were performed when necessary. Data about samples processing for bacteria, mycobacteria and fungi were collected. Results: Gene sequencing (71%), MALDI-TOF (59%) or both (94%) were available for most laboratories. Susceptibility testing was performed by automated microdilution systems (94%) and manual diffusion methods (59%). However, a low use of selective media for Staphylococcus aureus (59%) and Burkholderia cepacia complex (71%), and of epidemiological typing methods (41%) was reported. Conclusions: Most Spanish laboratories are in agreement with consensus guidelines for the processing of CF respiratory samples, but need to improve in the use of specific selective media and typing methods for epidemiologic studies.

Research paper thumbnail of Group B streptococcal meningitis in adults: report of twelve cases and review

Clinical infectious …, 1997

Group B streptococcus (GBS) is the leading etiologic agent of bacterial meningitis and sepsis dur... more Group B streptococcus (GBS) is the leading etiologic agent of bacterial meningitis and sepsis during the neonatal period, but it is an infrequent cause of meningitis in adults. We report 12 episodes of group B streptococcal meningitis in adults and review 52 cases reported in the literature. A total of 24 men and 40 women were included in the study; the mean age ({ SD) was 49.2 { 20.5 years (range, 17-89 years). All the patients had cerebrospinal fluid cultures positive for GBS. Eighty-six percent of the patients had comorbid conditions, 50% had a distant focus of infection, and blood cultures yielded GBS for 78.7%. The overall case-fatality rate was 34.4% (22 patients). Factors associated with a poor outcome were advanced mean age ({ SD) (61.5 { 17.4 years vs. 42.8 { 19.2 years; P Å .0003) and the presence of complications on admission (P Å .0001). Seven percent of survivors had neurological sequelae. Group B streptococcal meningitis in adults has become increasingly frequent in recent years; it tends to occur in patients with severe underlying conditions and is associated with a high casefatality rate. Factors associated with a poor prognosis are advanced age and the occurrence of neurological and extraneurological complications.