The biota of the Hawkesbury-Nepean catchment: reconstruction and restoration

Despite 200 years of European settlement, the Hawkesbury-Nepean catchment sustains a rich and diverse fauna. This is a consequence of extensive sandstone environments largely unsuited for development that escaped the extensive habitat modifications affecting the fauna of the grassy woodlands on the Cumberland Plain and Southern Tablelands. The most significant impacts followed the clearing and fragmentation of the vegetation for agriculture. Changed fire regimes, the naturalization of exotic plants and animals, and disease were also factors in the decline of native birds and mammals. Data on frogs and reptiles are limited, but some reptiles have declined in abundance in association with the loss of habitats. Not all native species have been adversely affected by European settlement and a number of birds have increased in abundance and extended their range within the catchment. Agricultural clearing and urban development have also affected aquatic ecosystems. The pre-European environment was apparently characterized by creek and river systems subjected to periodic floods, but with clear water, low nutrient levels, and clean sandly or rocky substrates. Increased nutrient levels, turbidity and siltation associated with urban and rural effluents, land clearing, foreshore erosion and river bed mining has reduced the extent of seagrass communities in the lower Hawkesbury and changed the substrate of rivers and the estuary. Mangrove communities have expanded. Other impacts on aquatic environments include the removal of riparian vegetation and the draining of wetlands, changes of flow regimes, dredging of channels, pollution of water from domestic, industrial and agricultural sources, changes in salinity, eutrophication of wetlands and the over-exploitation of the aquatic fauna. In freshwater creeks and rivers the native fauna has declined in abundance, while introduced species have spread throughout the catchment. In estuarine and marine environments, the fauna associated with clear water, low siltation rates, and seagrass beds has declined and species that were formerly abundant are now scarce. The native terrestrial and aquatic fauna in the catchment will continue to decline with urban expansion and better management of human activities within the catchment is urgently required. Further clearing within the catchment is unwise and existing vegetation remnants (including freshwater wetlands) should be protected from development. This is particularly important on the Cumberland Plain and Southern Tablelands where as distinctive fauna is associated with vegetation remnants and the reserve system is inadequate. Similarly provision needs to be made for minimum freshwater flows into the Hawkesbury-Nepean estuary. Nutrient removal from sewage, control of stormwater runoff, and better management of agricultural chemicals, fertilizers and mining within the catchment is necessary to restore water quality. Foreshoes should be revegetated. Most importantly, urban expansion and population growth within the catchment should be restricted

Comparing HIV case detection in prison during opt-in vs. Opt-out testing policies

Routine HIV screening in health care settings, including prisons and jails, is recommended by the US Centers for Disease Control and Prevention to enhance the detection of HIV infection

Symptomatic Sinus Node Disease: Natural History After Permanent Ventricular Pacing *

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75403/1/j.1540-8159.1979.tb03650.x.pd

Structural characterisation of neutrophil glycans by ultra sensitive mass spectrometric glycomics methodology

Neutrophils are the most abundant white blood cells in humans and play a vital role in several aspects of the immune response. Numerous reports have implicated neutrophil glycosylation as an important factor in mediating these interactions. We report here the application of high sensitivity glycomics methodologies, including matrix assisted laser desorption ionisation (MALDI-TOF) and MALDI-TOF/TOF analyses, to the structural analysis of N- and O-linked carbohydrates released from two samples of neutrophils, prepared by two separate and geographically remote laboratories. The data produced demonstrates that the cells display a diverse range of sialylated and fucosylated complex glycans, with a high level of similarity between the two preparations

Engineering a new loop-free shortest paths routing algorithm

International audienceWe present LFR (Loop Free Routing), a new loop-free distance vector routing algorithm, which is able to update the shortest paths of a distributed network with n nodes in fully dynamic scenarios. If Phi is the total number of nodes affected by a set of updates to the network, and phi is the maximum number of destinations for which a node is affected, then LFR requires O(Phi*Delta) messages and O(n + phi*Delta) space per node, where Delta is the maximum degree of the nodes of the network. We experimentally compare LFR with DUAL, one of the most popular loop-free distance vector algorithms, which is part of CISCO's EIGRP protocol and requires O(Phi*Delta) messages and Θ(n*Delta) space per node. The experiments are based on both real-world and artificial instances and show that LFR is always the best choice in terms of memory require- ments, while in terms of messages LFR outperforms DUAL on real-world instances, whereas DUAL is the best choice on artificial instances

The position of graptolites within Lower Palaeozoic planktic ecosystems.

An integrated approach has been used to assess the palaeoecology of graptolites both as a discrete group and also as a part of the biota present within Ordovician and Silurian planktic realms. Study of the functional morphology of graptolites and comparisons with recent ecological analogues demonstrates that graptolites most probably filled a variety of niches as primary consumers, with modes of life related to the colony morphotype. Graptolite coloniality was extremely ordered, lacking any close morphological analogues in Recent faunas. To obtain maximum functional efficiency, graptolites would have needed varying degrees of coordinated automobility. A change in lifestyle related to ontogenetic changes was prevalent within many graptolite groups. Differing lifestyle was reflected by differing reproductive strategies, with synrhabdosomes most likely being a method for rapid asexual reproduction. Direct evidence in the form of graptolithophage 'coprolitic' bodies, as well as indirect evidence in the form of probable defensive adaptations, indicate that graptolites comprised a food item for a variety of predators. Graptolites were also hosts to a variety of parasitic organisms and provided an important nutrient source for scavenging organisms

scRNA-seq in medulloblastoma shows cellular heterogeneity and lineage expansion support resistance to SHH inhibitor therapy

Targeting oncogenic pathways holds promise for brain tumor treatment, but inhibition of Sonic Hedgehog (SHH) signaling has failed in SHH-driven medulloblastoma. Cellular diversity within tumors and reduced lineage commitment can undermine targeted therapy by increasing the probability of treatment-resistant populations. Using single-cell RNA-seq and lineage tracing, we analyzed cellular diversity in medulloblastomas in transgenic, medulloblastoma-prone mice, and responses to the SHH-pathway inhibitor vismodegib. In untreated tumors, we find expected stromal cells and tumor-derived cells showing either a spectrum of neural progenitor-differentiation states or glial and stem cell markers. Vismodegib reduces the proliferative population and increases differentiation. However, specific cell types in vismodegib-treated tumors remain proliferative, showing either persistent SHH-pathway activation or stem cell characteristics. Our data show that even in tumors with a single pathway-activating mutation, diverse mechanisms drive tumor growth. This diversity confers early resistance to targeted inhibitor therapy, demonstrating the need to target multiple pathways simultaneously