bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impact of Glutamine Transporters on Pneumococcal Fitness under Infection-Related Conditions
Authors: Härtel Tobias , Klein Matthias , Koedel Uwe , Rohde Manfred , Petruschka Lothar , Hammerschmidt Sven 
Published: November 2010

ABSTRACTThe genomic analysis ofStreptococcuspneumoniaepredicted six putative glutamine uptake systems, which are expressed underinvitroconditions, as shown here by reverse transcription-PCR. Four of these operons consist ofglnHPQ, while two lackglnH, which encodes a soluble glutamine-binding protein. Here, we studied the impact of two of these glutamine ATP-binding cassette transporters onS.pneumoniaeD39 virulence and phagocytosis, which consist of GlnQ and a translationally fused protein of GlnH and GlnP. Mice infected intranasally with D39Δgln0411/0412showed significantly increased survival times and a significant delay in the development of pneumococcal pneumonia compared to those infected with D39, as observed in real time using bioluminescent pneumococci. In a mouse sepsis model, the mutant D39Δgln0411/0412showed only moderate but significant attenuation. In contrast, the D39Δgln1098/1099knockout strain was massively attenuated in the pneumonia and septicemia mouse infection model. To cause pneumonia or sepsis with D39Δgln1098/1099, infection doses 100- to 10,000-fold higher than those used for wild-type strain D39 were required. In an experimental mouse meningitis model, D39Δgln1098/1099produced decreased levels of white blood cells in cerebrospinal fluid and showed decreased numbers of bacteria in the bloodstream compared to D39 and D39Δgln0411/0412. Phagocytosis experiments revealed significantly decreased intracellular survival rates of mutants D39Δgln1098/1099and D39Δgln0411/0412compared to wild-type D39, suggesting that the deficiency of Gln uptake systems impairs resistance to oxidative stress. Taken together, our results demonstrate that both glutamine uptake systems are required for full virulence of pneumococci but exhibit different impacts on the pathogenesis of pneumococci underinvivoconditions.
Vaccination againstChlamydiaGenital Infection Utilizing the MurineC. muridarumModel
Authors: Farris Christina M. , Morrison Richard P. 
Published: November 2010

ABSTRACTChlamydia trachomatisgenital infection is a worldwide public health problem, and considerable effort has been expended on developing an efficacious vaccine. The murine model ofC. muridarumgenital infection has been extremely useful for identification of protective immune responses and in vaccine development. Although a number of immunogenic antigens have been assessed for their ability to induce protection, the majority of studies have utilized the whole organism, the major outer membrane protein (MOMP), or the chlamydial protease-like activity factor (CPAF). These antigens, alone and in combination with a variety of immunostimulatory adjuvants, have induced various levels of protection against infectious challenge, ranging from minimal to nearly sterilizing immunity. Understanding of the mechanisms of natural infection-based immunity and advances in adjuvant biology have resulted in studies that are increasingly successful, but a vaccine licensed for use in humans has not yet been brought to fruition. Here we review immunity to chlamydial genital infection and vaccine development using theC. muridarummodel.
Uropathogenic
Escherichia coli
Induces Chronic Pelvic Pain
Authors: Rudick Charles N. , Berry Ruth E. , Johnson James R. , Johnston Brian , Klumpp David J. , Schaeffer Anthony J. , Thumbikat Praveen 
Published: November 2010

ABSTRACT

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is a debilitating syndrome of unknown etiology often postulated, but not proven, to be associated with microbial infection of the prostate gland. We hypothesized that infection of the prostate by clinically relevant uropathogenic
Escherichia coli
(UPEC) can initiate and establish chronic pain. We utilized an
E. coli
strain newly isolated from a patient with CP/CPPS (strain CP1) and examined its molecular pathogenesis in cell culture and in a murine model of bacterial prostatitis. We found that CP1 is an atypical isolate distinct from most UPEC in its phylotype and virulence factor profile. CP1 adhered to, invaded, and proliferated within prostate epithelia and colonized the prostate and bladder of NOD and C57BL/6J mice. Using behavioral measures of pelvic pain, we showed that CP1 induced and sustained chronic pelvic pain in NOD mice, an attribute not exhibited by a clinical cystitis strain. Furthermore, pain was observed to persist even after bacterial clearance from genitourinary tissues. CP1 induced pelvic pain behavior exclusively in NOD mice and not in C57BL/6J mice, despite comparable levels of colonization and inflammation. Microbial infections can thus serve as initiating agents for chronic pelvic pain through mechanisms that are dependent on both the virulence of the bacterial strain and the genetic background of the host.
Human Leukocytes Kill
Aspergillus nidulans
by Reactive Oxygen Species-Independent Mechanisms
Authors: Henriet Stefanie S. V. , Hermans Peter W. M. , Verweij Paul E. , Simonetti Elles , Holland Steven M. , Sugui Janyce A. , Kwon-Chung Kyung J. , Warris Adilia 
Published: November 2010

ABSTRACT

Invasive aspergillosis is a major threat for patients suffering from chronic granulomatous disease (CGD). Although
Aspergillus fumigatus
is the most commonly encountered
Aspergillus
species, the presence of
A. nidulans
appears to be disproportionately high in CGD patients. The purpose of this study was to investigate the involvement of the NADPH oxidase and the resulting reactive oxygen species (ROS) in host defense against fungi and to clarify their relationship toward
A. nidulans
. Murine CGD alveolar macrophages (AM) and polymorphonuclear leukocytes (PMN) and peripheral blood mononuclear cells (PBMC) from healthy controls and CGD patients were challenged with either
A. fumigatus
or
A. nidulans
. Analysis of the antifungal effects of ROS revealed that
A. nidulans
, in contrast to
A. fumigatus
, is not susceptible to ROS. In addition, infection with live
A. nidulans
did not result in any measurable ROS release. Remarkably, human CGD PMN and PBMC and murine CGD AM were at least equipotent at arresting conidial germination compared to healthy controls. Blocking of the NADPH oxidase resulted in significantly reduced damage of
A. fumigatus
but did not affect
A. nidulans
hyphae. Furthermore, the microbicidal activity of CGD PMN was maintained toward
A. nidulans
but not
A. fumigatus
. In summary, antifungal resistance to
A. nidulans
is not directly ROS related. The etiology of
A. nidulans
infections in CGD cannot be explained by the simple absence of the direct microbicidal effect of ROS.
In vivo
, the NADPH oxidase is a critical regulator of innate immunity whose unraveling will improve our understanding of fungal pathogenesis in CGD.
A Comparative Genomic Analysis of Diverse Clonal Types of EnterotoxigenicEscherichia coliReveals Pathovar-Specific Conservation
Authors: Sahl Jason W. , Steinsland Hans , Redman Julia C. , Angiuoli Samuel V. , Nataro James P. , Sommerfelt Halvor , Rasko David A. 
Published: November 2010

ABSTRACTEnterotoxigenicEscherichia coli(ETEC) is a major cause of diarrheal illness in children less than 5 years of age in low- and middle-income nations, whereas it is an emerging enteric pathogen in industrialized nations. Despite being an important cause of diarrhea, little is known about the genomic composition of ETEC. To address this, we sequenced the genomes of five ETEC isolates obtained from children in Guinea-Bissau with diarrhea. These five isolates represent distinct and globally dominant ETEC clonal groups. Comparative genomic analyses utilizing a gene-independent whole-genome alignment method demonstrated that sequenced ETEC strains share approximately 2.7 million bases of genomic sequence. Phylogenetic analysis of this “core genome” confirmed the diverse history of the ETEC pathovar and provides a finer resolution of theE. colirelationships than multilocus sequence typing. No identified genomic regions were conserved exclusively in all ETEC genomes; however, we identified more genomic content conserved among ETEC genomes than among non-ETECE. coligenomes, suggesting that ETEC isolates share a genomic core. Comparisons of known virulence and of surface-exposed and colonization factor genes across all sequenced ETEC genomes not only identified variability but also indicated that some antigens are restricted to the ETEC pathovar. Overall, the generation of these five genome sequences, in addition to the two previously generated ETEC genomes, highlights the genomic diversity of ETEC. These studies increase our understanding of ETEC evolution, as well as provide insight into virulence factors and conserved proteins, which may be targets for vaccine development.
Coxiella burnetiiAcid Phosphatase Inhibits the Release of Reactive Oxygen Intermediates in Polymorphonuclear Leukocytes
Authors: Hill J. , Samuel J. E. 
Published: November 2010

ABSTRACTCoxiella burnetii, the etiological agent of Q fever, is a small, Gram-negative, obligate intracellular bacterium. Replication ofC. burnetiiduring infection has been shown to be increased by decreasing oxidative stress using p47phox −/−and iNOS−/−micein vivoand by pharmacologic inhibitorsin vitro. Building upon this model, we investigated the role polymorphonuclear leukocytes (PMN) play in the control of infection, since NADPH oxidase-mediated release of reactive oxygen intermediates (ROI) is a primary bactericidal mechanism for these cells that is critical for early innate clearance. Earlier studies suggested thatC. burnetiiactively inhibited release of ROI from PMN through expression of an unidentified acid phosphatase (ACP). Recent genomic annotations identified one open reading frame (CBU0335) which may encode a Sec- and type II-dependent secreted ACP. To test this model, viableC. burnetiipropagated in tissue culture host cells or axenic media,C. burnetiiextracts, or purified recombinant ACP (rACP) was combined with human PMN induced with 4-phorbol 12-myristate 13-acetate (PMA). The release of ROI was inhibited when PMN were challenged with viableC. burnetii,C. burnetiiextracts, or rACP but not when PMN were challenged with electron beam-inactivatedC. burnetii. C. burnetiiextracts and rACP were also able to inhibit PMA-induced formation of NADPH oxidase complex on PMN membranes, suggesting a molecular mechanism responsible for this inhibition. These data support a model in whichC. burnetiieludes the primary ROI killing mechanism of activated PMN by secreting at least one acid phosphatase.
Advances in Quaternary studies in Tasmania
Authors: Colhoun Eric A. , Kiernan Kevin , Barrows Timothy T. , Goede Albert 
Published: November 2010

Abstract
The last 35 years have seen rapid advances in our knowledge of climate change during the Quaternary Period in Tasmania. Extensive mapping and new dating studies, particularly since the advent of exposure dating, have revealed that maximum ice advance occurred 1 Ma ago and later advances were less extensive. Ice advances occurred several times during the last 100 ka, not only during the Last Glacial Maximum. Deglaciation was rapid after 18 ka and complete by 14 ka. Ice strongly affected limestone and produced extensive glaciokarst with deranged surface drainage. Glacial sediment plugged conduits to underground passages partially filled with glaciofluvial gravels. Periglacial erosion, and human impact since late oxygen isotope stage (OIS) 3, enhanced sediment influxes. New pollen records, particularly from Lake Selina, provide a 125 ka vegetation and climate record representative of the Southern Hemisphere. Finally, stable isotope studies of speleothem growth have revealed wide swings in climate. The climate was warm and moist during OIS 5e and early in OIS 1. Climate was cold and dry during OIS 5d and 4, and prevented speleothem growth during OIS 3 and OIS 2.
‘Of droughts and flooding rains’: an alluvial loess record from central South Australia spanning the last glacial cycle
Authors: Haberlah David , Glasby Peter , Williams Martin A. J. , Hill Steven M. , Williams Frances , Rhodes Edward J. , Gostin Victor , O'Flaherty Anthony , Jacobsen Geraldine E. 
Published: November 2010

Abstract

Deposits of proximal dust-derived alluvium (alluvial loess) within the catchments of the now semi-arid Flinders Ranges in South Australia record regionally synchronous intervals of fluvial entrainment, aggradation and down-cutting spanning the last glacial cycle. Today, these floodplain remnants are deeply entrenched and laterally eroded by ephemeral traction load streams. The north–south aligned ranges are strategically situated within the present-day transitional zone, receiving both topographically enhanced winter rainfall from the SW and convectional downpours from summer monsoonal incursions from the north. We develop a regional chronostratigraphy of depositional and erosional events emphasizing the Last Glacial Maximum (LGM). Based on 124 ages (94 accelerator mass spectrometry radiocarbon and 30 optically stimulated luminescence) from the most significant terrace remnants on both sides of the Ranges, we conclude that the last glacial cycle including the LGM was characterized by major environmental changes. Two pronounced periods of pedogenesis between
c
. 36 and 30 ka were followed by widespread erosion and reworking. A short-lived interval of climatic stability before
c
. 24 ka was followed by conditions in which large amounts of proximal dust (loess) were deposited across the catchments. These loess mantles were rapidly redistributed and episodically transported downstream by floods. The termination of this regime
c
. 18–16 ka was marked by rapid incision.
Tectonic geomorphology of Australia
Authors: Quigley Mark C. , Clark Dan , Sandiford Mike 
Published: November 2010

Abstract

The Australian continent is actively deforming in response to far-field stresses generated by plate boundary interactions and buoyancy forces associated with mantle dynamics. On the largest scale (several 10
3
km), the submergence of the northern continental shelf is driven by dynamic topography caused by mantle downwelling along the Indo-Pacific subduction system and accentuated by a regionally elevated geoid. The emergence of the southern shelf is attributed to the progressive movement of Australia away from a dynamic topography low. On the intermediate scale (several 10
2
km), low-amplitude (
c
. 100–200 m) long-wavelength (
c
. 100–300 km) topographic undulations are driven by (1) anomalous, smaller-scale upper mantle convection, and/or (2) lithospheric-scale buckling associated with plate boundary tectonic forcing. On the smallest scale (10
1
km), fault-related deformation driven by partitioning of far-field stresses has modified surface topography at rates of up to
c
. 170 m Ma
−1
, generated more than 30–50% of the contemporary topographic relief between some of Australia's highlands and adjacent piedmonts, and exerted a first-order control on long-term (10
4
–10
6
a) bedrock erosion. Although Australia is often regarded as tectonically and geomorphologically quiescent, Neogene to Recent tectonically induced landscape evolution has occurred across the continent, with geomorphological expressions ranging from mild to dramatic.
Lithology and the evolution of bedrock rivers in post-orogenic settings: constraints from the high-elevation passive continental margin of SE Australia
Authors: Bishop Paul , Goldrick Geoff 
Published: November 2010

Abstract
Understanding the role of lithological variation in the evolution of topography remains a fundamental issue, especially in the neglected post-orogenic terrains. Such settings represent the major part of the Earth's surface and recent modelling suggests that a range of interactions can account for the presence of residual topography for hundreds of millions of years, thereby explaining the great antiquity of landscapes in such settings. Field data from the inland flank of the SE Australian high-elevation continental margin suggest that resistant lithologies act to retard or even preclude the headward transmission of base-level fall driven by the isostatic response to regional denudation. Rejuvenation, be it episodic or continuous, is ‘caught up’ on these resistant lithologies, meaning in effect that the bedrock channels and hillslopes upstream of these ‘stalled’ knickpoints have become detached from the base-level changes downstream of the knickpoints. Until these knickpoints are breached, therefore, catchment relief must increase over time, a landscape evolution scenario that has been most notably suggested by Crickmay and Twidale. The role of resistant lithologies indicates that detachment-limited conditions are a key to the longevity of some post-orogenic landscapes, whereas the general importance of transport-limited conditions in the evolution of post-orogenic landscapes remains to be evaluated in field settings. Non-steady-state landscapes may lie at the heart of widespread, slowly evolving post-orogenic settings, such as high-elevation passive continental margins, meaning that non-steady-state landscapes, with increasing relief through time, are the ‘rule’ rather than the exception.
Rethinking eastern Australian caves
Authors: Osborne R. A. L. 
Published: November 2010

Abstract
There are some 300 bodies of cavernous limestone in eastern Australia, extending from Precipitous Bluff in southeastern Tasmania to the Mitchell Palmer region in north Queensland. These impounded karsts, developed in Palaeozoic limestones of the Tasman Fold Belt System, contain many caves. The caves have a suite of features in common that allows them to be thought of as a major group: the Tasmanic Caves. The Tasmanic Caves include multiphase hypogene caves such as Cathedral Cave at Wellington and multiphase, multiprocess caves such as Jenolan with Carboniferous hypogene and younger paragenetic and fluvial elements. Active hypogene caves occur at Wee Jasper and possibly at five other localities. The Tasmanic Caves are one of the most complex suites of caves in folded Palaeozoic limestones in the world. Field techniques developed to study these caves are now being applied to complex caves in central Europe: in the Czech Republic, Hungary, Poland, Slovakia and Slovenia.
Are the Murray Canyons offshore southern Australia still active for sediment transport?
Authors: Schmidt S. , De Deckker P. , Etcheber H. , Caradec S. 
Published: November 2010

Abstract

The Australian continental margin hosts numerous canyons. Some of the most spectacular canyons are located offshore Kangaroo Island, and these are linked to ancient courses of the River Murray, which would have flowed across the very wide Lacepede Shelf during periods of low sea level. During the AUSCAN-1 project, modern sedimentation was assessed using a multi-tracer approach on interface sediments from 350 to 2500 m water depth. The presence of freshly deposited particles, tagged by
234
Th in excess,
210
Pb-based sediment accumulation (0.03–0.13 cm a
−1
) and
230
Th-based focusing ratios, supports the occurrence of significant advection of marine sediments within these canyons. In the absence of direct riverine inputs, the shelf, being the site of intensive carbonate production, is the main supplier of material. The presence of incised channels in the eastern portion of the Murray Canyons Group (MCG) indicates recent to sub-recent activity along the canyons. The presence of underwater slides in the western side of the MCG confirms that sediment transport to the abyssal plain does occur. Based on our preliminary investigation and by synthesizing previous work on other canyons, we provide a conceptual model for sediment focusing and transfer within the canyons offshore Australia.
East Australian marine abrasion surface
Authors: Thom Bruce G. , Keene Jock B. , Cowell Peter J. , Daley Marc 
Published: November 2010

Abstract

Almost one-third of the seabed off the coastline north and south of Sydney comprises a planated bedrock surface, evident from sidescan surveys over the inner continental shelf. In seismic records, this rock surface extends up to 23 km offshore from the sea cliffs along 300 km of the coast. The rock surface dips offshore to as much as 180 m below sea level, where it merges with a major unconformity in the shelf sediment wedge. The surface is eroded into Mesozoic and Palaeozic rocks and is heavily dissected by sediment-filled, palaeo-valley incision and structural jointing. The sediment-fills comprise sand wedges that thicken landwards to form beaches and estuarine flood-tide deltas, respectively, in smaller and larger palaeo-valleys incised to below present sea level. At the base of the cliffs, the planated surface is buried by shelf sand bodies up to 30 m thick in places. The seaward edge of the surface is everywhere buried by the onlapping continental-shelf sediment wedge. The contiguity of the abrasion surface with the unconformity in the shelf sediment wedge suggests that marine planation began in the Mid-Oligocene, indicating time-average rates of gross cliff retreat at about 1 mm a
−1
.
Geoarchaeology in Australia: understanding human-environment interactions
Authors: Holdaway Simon J. , Fanning Patricia C. 
Published: November 2010

Abstract
This paper reviews the long history of interaction between scientists working in geomorphology, stratigraphy, sedimentology and chronology and those working in archaeology to understand past human–environment interactions in Australia. Despite this close collaboration, differentiating environmental impacts from the influence of human behaviour has proven difficult in research on key topics such as the causes of megafauna extinction, the significance of fire, and the impact of climatic shifts such as the El Niño–Southern Oscillation. Geoarchaeological research focused on depositional environments and post-depositional change in western New South Wales, Australia, provides important examples of how processes acting over different temporal scales affect archaeological deposits. The archaeological record is in some places discontinuous in time because geomorphological activity has removed the record of particular time periods, and it is discontinuous in space because it is preserved only in places that are geomorphologically relatively inactive. Important inferences concerning past human behaviours may be drawn from the record, but the processes responsible for both the presence and absence of the record must be considered. More attention needs to be given to ensuring that datasets with a similar temporal resolution are compared if the causes for behavioural changes in the past are to be correctly understood.