title: Ancient origins determine global biogeography of hot and cold desert cyanobacteria

authors: Bahl, Justin

subjects: biological sciences

abstract: Factors governing large-scale spatio-temporal distribution of microorganisms remain unresolved, yet are pivotal to understanding ecosystem value and function. Molecular genetic analyses have focused on the influence of niche and neutral processes in determining spatial patterns without considering the temporal scale. Here, we use temporal phylogenetic analysis calibrated using microfossil data for a globally sampled desert cyanobacterium, Chroococcidiopsis, to investigate spatio-temporal patterns in microbial biogeography and evolution. Multilocus phylogenetic associations were dependent on contemporary climate with no evidence for distance-related patterns. Massively parallel pyrosequencing of environmental samples confirmed that Chroococcidiopsis variants were specific to either hot or cold deserts. Temporally scaled phylogenetic analyses showed no evidence of recent inter-regional gene flow, indicating populations have not shared common ancestry since before the formation of modern continents. These results indicate that global distribution of desert cyanobacteria has not resulted from widespread contemporary dispersal but is an ancient evolutionary legacy. This highlights the importance of considering temporal scales in microbial biogeography.

text: Ancient origins determine global biogeography of hot and cold desert cyanobacteria Factors governing large-scale spatio-temporal distribution of microorganisms remain unresolved, yet are pivotal to understanding ecosystem value and function. Molecular genetic analyses have focused on the influence of niche and neutral processes in determining spatial patterns without considering the temporal scale. Here, we use temporal phylogenetic analysis calibrated using microfossil data for a globally sampled desert cyanobacterium, Chroococcidiopsis, to investigate spatio-temporal patterns in microbial biogeography and evolution. Multilocus phylogenetic associations were dependent on contemporary climate with no evidence for distance-related patterns. Massively parallel pyrosequencing of environmental samples confirmed that Chroococcidiopsis variants were specific to either hot or cold deserts. Temporally scaled phylogenetic analyses showed no evidence of recent inter-regional gene flow, indicating populations have not shared common ancestry since before the formation of modern continents. These results indicate that global distribution of desert cyanobacteria has not resulted from widespread contemporary dispersal but is an ancient evolutionary legacy. This highlights the importance of considering temporal scales in microbial biogeography.

year: 2010

title: Security Analysis of the Evolved Packet Core for LTE Networks

authors: Wadsworth, Simon Oliver

subjects: LTE

abstract: Originally cellular networks handled calls and short messages only. Today, this has been extended to handle packet data services. However now the world is moving towards an entirely IP based mobile service based on LTE and the Evolved Packet Core. Security becomes even more important than before. Cellular networks will be using the same technology that runs the Internet, which could leave them open to a range of threats from the air interface side of the network, especially with the popularity of smart phones and USB "Mobile Broadband" modems. This thesis investigated a range of network protocols used in the Evolved Packet Core, as well as the possibility of attacks against these networks and their protocols and whether such attacks can be achieved, especially from cheap handheld devices. Further this thesis presents results showing that these network protocols are free from serious flaws in their specification.

text: Security Analysis of the Evolved Packet Core for LTE Networks Originally cellular networks handled calls and short messages only. Today, this has been extended to handle packet data services. However now the world is moving towards an entirely IP based mobile service based on LTE and the Evolved Packet Core. Security becomes even more important than before. Cellular networks will be using the same technology that runs the Internet, which could leave them open to a range of threats from the air interface side of the network, especially with the popularity of smart phones and USB "Mobile Broadband" modems. This thesis investigated a range of network protocols used in the Evolved Packet Core, as well as the possibility of attacks against these networks and their protocols and whether such attacks can be achieved, especially from cheap handheld devices. Further this thesis presents results showing that these network protocols are free from serious flaws in their specification.

year: 2013

title: Kia kāpuia te reo o Tāmaki ki te Tonga: Tāmaki Makaurau ki te Tonga

authors: Lee-Morgan, Jenny Bol Jun

abstract: Mai i te Papakuratanga o Mataoho tae noa ki tona Ipu. Mai i Pukaki Tapu o Poutiikeka ki Te Puketapapatanga a Hape. Mai i te tahuna o Torea i nga wai o Mokoia, mawhiti atu ki Te Arapueru e karekare mai na ko Te Manukanuka a Hoturoa, kei reira a Taramainuku raua ko Kaiwhare. Ka kawea ki nga.hau o Mangere, e topa ai taku manuhokahoka ki Te Manurewatanga a Tamapahore. Whakaterawhiti taku haere ki Otara-a-nuku, ki Otara-a-rangi koia te tikapatanga o toku tiipuna o Marutuahu. Hoki whenei mai au ki Te Pane o Mataoho, tiro kau ake au ki aku pa whakairo ko Matatukutureia, ko Matukurua nga nohoanga tapu o Huakaiwaka, o Nga Tini-o-toitehuatahi, o Maruiwi kua ngaro katoa ki te reinga.

text: Kia kāpuia te reo o Tāmaki ki te Tonga: Tāmaki Makaurau ki te Tonga Mai i te Papakuratanga o Mataoho tae noa ki tona Ipu. Mai i Pukaki Tapu o Poutiikeka ki Te Puketapapatanga a Hape. Mai i te tahuna o Torea i nga wai o Mokoia, mawhiti atu ki Te Arapueru e karekare mai na ko Te Manukanuka a Hoturoa, kei reira a Taramainuku raua ko Kaiwhare. Ka kawea ki nga.hau o Mangere, e topa ai taku manuhokahoka ki Te Manurewatanga a Tamapahore. Whakaterawhiti taku haere ki Otara-a-nuku, ki Otara-a-rangi koia te tikapatanga o toku tiipuna o Marutuahu. Hoki whenei mai au ki Te Pane o Mataoho, tiro kau ake au ki aku pa whakairo ko Matatukutureia, ko Matukurua nga nohoanga tapu o Huakaiwaka, o Nga Tini-o-toitehuatahi, o Maruiwi kua ngaro katoa ki te reinga.

year: 2017