863 research outputs found
A review of the Cenozoic palynostratigraphy of the River Valleys in Central and Western New South Wales.
The palynology of sediments from the Murray, Murrumbidgee, Lachlan, Macquarie and Namoi River Valleys of the Western Slopes of New South Wales reveals remarkably similar patterns in the alluvium of all of the valleys. Mid Miocene and older palynofloras found on the flood plains are rarely (if ever) seen in the valleys where almost all of the palynofloras are placed in the late Miocene-Pliocene M. galeatus Zone. A few palynofloras of the Pleistocene T. pleistocenicus Zone are found at the top of the sequence. The alluvial fills of the palaeovalleys are similar also: in a basal late Miocene-Pliocene unit: the sands and gravels are almost entirely quartz whereas the upper unit of Pleistocene age has a variety of resistant rock types and only a minor quartz component. The alluvium of these river valleys is an important groundwater resource.
In the mid Miocene, a time of high sea level, the rivers of the Western Slopes discharged into the flooded Murray Basin. Following major falls in sea level in the late Miocene, there was a basin-wide time of erosion/non-deposition and entrenchment of the river valleys. Denudation associated with this regression removed older sediments in the valleys and probably carved out the valley-in-valley structures. Tectonic events were probably small and only maintained the elevation of the Highlands.
The palynofloras indicate a substantial change in the vegetation and climate over this time: from rainforest and a wet climate in the mid Miocene to eucalypt sclerophyll forest and a drier, more seasonal climate in the late Miocene-Pliocene to woodlands/grasslands and a much drier climate in the Pleistocene. Deposition of the basal quartz rich alluvial unit occurred under a high rainfall, high-energy regime whereas the upper unit was deposited under a drier climate and low energy regime.
Eustasy was a major forcing factor in the Neogene, but by Pleistocene time, the Murray Basin had become isolated from the sea and the much drier climate had become the major forcing factor
The Story of Science House and the History of the Linnean Society of New South Wales
Science House was built in 1930-31 by its co-owners, the Linnean Society of New South Wales, the Royal Society of New South Wales and the Institute of Engineers Australia, with assistance from the State Government, as “a centre for the Learned Societies”. Office space was rented to scientific and professional societies and halls were hired out for meetings. Profits were divided equally between the three co-owners and the venture was successful. In 1968, the State Government gave notice that Science House would be compulsorily acquired for demolition as part of Sydney Cove Redevelopment Authority Scheme. Compensation was paid and the Societies moved out, but the redevelopment did not go ahead. Science House as a physical entity survived, but the Societies had lost ownership. The Linnean Society of New South Wales and the Royal Society of New South Wales attempted a similar venture in a new Science Centre, but this was not successful.
Throughout this time and to the present day, the Linnean Society of New South Wales has successfully maintained its core function of promoting natural history. It publishes a journal of original research papers each year and occasionally, other books. It holds regular members meetings, presents public lectures, sponsors symposia and field trips, and actively supports scientific research. The Society has managed to adapt to the changing circumstances throughout this time
The Holocene History of the Vegetation and the Environment of Jibbon Swamp, Royal National Park, New South Wales
Jibbon Swamp, in the north eastern part of Royal National Park, yielded a sedimentary history of 8,000 years. The present vegetation was mapped and the modern pollen deposition studied in order to assist interpretation. The palynology infers little change in the vegetation, other than a shifting mosaic of sclerophyllous communities similar to those seen in the area today.The nature of the accumulating sediments and their algal and fungal spore content can be interpreted to reflect the hydrological history of the swamp. An initial establishment period of 8,000 to 5,500 year ago was followed by a permanent pool of water too deep for the sedgeland swamp vegetation, from 5,500 to 2,400 years ago and then a vegetated swamp that dried out periodically, from 2,400 years ago to present, as it does today. Changes in the sediments and algae/fungi record suggest a wetter early Holocene and a drier mid-late Holocene climate, with an intensification of the dry periods about 2,500 years ago. This pattern of change seems to reflect regional climatic change. There is very little change in the less sensitive sclerophyllous vegetation. The likely impact of rising Holocene sea levels on this near-coastal environment is discussed
Efficient replication of pneumonia virus of mice (PVM) in a mouse macrophage cell line
Pneumonia virus of mice (PVM; family Paramyxoviridae, subfamily Pneumovirinae) is a natural respiratory pathogen of rodent species and an important new model for the study of severe viral bronchiolitis and pneumonia. However, despite high virus titers typically detected in infected mouse lung tissue in vivo, cell lines used routinely for virus propagation in vitro are not highly susceptible to PVM infection. We have evaluated several rodent and primate cell lines for susceptibility to PVM infection, and detected highest virus titers from infection of the mouse monocyte-macrophage RAW 264.7 cell line. Additionally, virus replication in RAW 264.7 cells induces the synthesis and secretion of proinflammatory cytokines relevant to respiratory virus disease, including tumor necrosis factor-α (TNF-α), interferon-β (IFN-β), macrophage inflammatory proteins 1α and 1β (MIP-1α and MIP-1β) and the functional homolog of human IL-8, mouse macrophage inflammatory peptide-2 (MIP-2). Identification and characterization of a rodent cell line that supports the replication of PVM and induces the synthesis of disease-related proinflammatory mediators will facilitate studies of molecular mechanisms of viral pathogenesis that will complement and expand on findings from mouse model systems
Differences between CO- and calcium triplet-derived velocity dispersions in spiral galaxies: evidence for central star formation?
We examine the stellar velocity dispersions (sigma) of a sample of 48
galaxies, 35 of which are spirals, from the Palomar nearby galaxy survey. It is
known that for ultra-luminous infrared galaxies (ULIRGs) and merger remnants
thesigma derived from the near-infrared CO band-heads is smaller than that
measured from optical lines, while no discrepancy between these measurements is
found for early-type galaxies. No such studies are available for spiral
galaxies - the subject of this paper. We used cross-dispersed spectroscopic
data obtained with the Gemini Near-Infrared Spectrograph (GNIRS), with spectral
coverage from 0.85 to 2.5um, to obtain sigma measurements from the 2.29 m
CO band-heads (sigma_{CO}), and the 0.85 um calcium triplet (sigma_{CaT}). For
the spiral galaxies in the sample, we found that sigma_{CO} is smaller than
sigma_{CaT}, with a mean fractional difference of 14.3%. The best fit to the
data is given by sigma_{opt} = (46.0+/-18.1) + (0.85+/-0.12)sigma_{CO}. This
"sigma discrepancy" may be related to the presence of warm dust, as suggested
by a slight correlation between the discrepancy and the infrared luminosity.
This is consistent with studies that have found no sigma-discrepancy in
dust-poor early-type galaxies, and a much larger discrepancy in dusty merger
remnants and ULIRGs. That sigma_{CO}$ is lower than sigma_{opt} may also
indicate the presence of a dynamically cold stellar population component. This
would agree with the spatial correspondence between low sigma_{CO} and
young/intermediate-age stellar populations that has been observed in
spatially-resolved spectroscopy of a handful of galaxies.Comment: Published in MNRAS, 446, 282
Ultrasound evidence of altered lumbar connective tissue structure in human subjects with chronic low back pain
<p>Abstract</p> <p>Background</p> <p>Although the connective tissues forming the fascial planes of the back have been hypothesized to play a role in the pathogenesis of chronic low back pain (LBP), there have been no previous studies quantitatively evaluating connective tissue structure in this condition. The goal of this study was to perform an ultrasound-based comparison of perimuscular connective tissue structure in the lumbar region in a group of human subjects with chronic or recurrent LBP for more than 12 months, compared with a group of subjects without LBP.</p> <p>Methods</p> <p>In each of 107 human subjects (60 with LBP and 47 without LBP), parasagittal ultrasound images were acquired bilaterally centered on a point 2 cm lateral to the midpoint of the L2-3 interspinous ligament. The outcome measures based on these images were subcutaneous and perimuscular connective tissue thickness and echogenicity measured by ultrasound.</p> <p>Results</p> <p>There were no significant differences in age, sex, body mass index (BMI) or activity levels between LBP and No-LBP groups. Perimuscular thickness and echogenicity were not correlated with age but were positively correlated with BMI. The LBP group had ~25% greater perimuscular thickness and echogenicity compared with the No-LBP group (ANCOVA adjusted for BMI, p < 0.01 and p < 0.001 respectively).</p> <p>Conclusion</p> <p>This is the first report of abnormal connective tissue structure in the lumbar region in a group of subjects with chronic or recurrent LBP. This finding was not attributable to differences in age, sex, BMI or activity level between groups. Possible causes include genetic factors, abnormal movement patterns and chronic inflammation.</p
Relationship between the Plasma Proteome and Changes in Inflammatory Markers after Bariatric Surgery
Severe obesity is a disease associated with multiple adverse effects on health. Metabolic bariatric surgery (MBS) can have significant effects on multiple body systems and was shown to improve inflammatory markers in previous short-term follow-up studies. We evaluated associations between changes in inflammatory markers (CRP, IL6 and TNFα) and circulating proteins after MBS. Methods: Sequential window acquisition of all theoretical mass spectra (SWATH-MS) proteomics was performed on plasma samples taken at baseline (pre-surgery) and 6 and 12 months after MBS, and concurrent analyses of inflammatory/metabolic parameters were carried out. The change in absolute abundances of those proteins, showing significant change at both 6 and 12 months, was tested for correlation with the absolute and percentage (%) change in inflammatory markers. Results: We found the following results: at 6 months, there was a correlation between %change in IL-6 and fold change in HSPA4 (rho = −0.659; p = 0.038) and in SERPINF1 (rho = 0.714, p = 0.020); at 12 months, there was a positive correlation between %change in IL-6 and fold change in the following proteins—LGALS3BP (rho = 0.700, p = 0.036), HSP90B1 (rho = 0.667; p = 0.05) and ACE (rho = 0.667, p = 0.05). We found significant inverse correlations at 12 months between %change in TNFα and the following proteins: EPHX2 and ACE (for both rho = −0.783, p = 0.013). We also found significant inverse correlations between %change in CRP at 12 months and SHBG (rho = −0.759, p = 0.029), L1CAM (rho = −0.904, p = 0.002) and AMBP (rho = −0.684, p = 0.042). Conclusion: Using SWATH-MS, we identified several proteins that are involved in the inflammatory response whose levels change in patients who achieve remission of T2DM after bariatric surgery in tandem with changes in IL6, TNFα and/or CRP. Future studies are needed to clarify the underlying mechanisms in how MBS decreases low-grade inflammation
Warm Dust and Spatially Variable PAH Emission in the Dwarf Starburst Galaxy NGC 1705
We present Spitzer observations of the dwarf starburst galaxy NGC 1705
obtained as part of SINGS. The galaxy morphology is very different shortward
and longward of ~5 microns: short-wavelength imaging shows an underlying red
stellar population, with the central super star cluster (SSC) dominating the
luminosity; longer-wavelength data reveals warm dust emission arising from two
off-nuclear regions offset by ~250 pc from the SSC. These regions show little
extinction at optical wavelengths. The galaxy has a relatively low global dust
mass (~2E5 solar masses, implying a global dust-to-gas mass ratio ~2--4 times
lower than the Milky Way average). The off-nuclear dust emission appears to be
powered by photons from the same stellar population responsible for the
excitation of the observed H Alpha emission; these photons are unassociated
with the SSC (though a contribution from embedded sources to the IR luminosity
of the off-nuclear regions cannot be ruled out). Low-resolution IRS
spectroscopy shows moderate-strength PAH emission in the 11.3 micron band in
the eastern peak; no PAH emission is detected in the SSC or the western dust
emission complex. There is significant diffuse 8 micron emission after scaling
and subtracting shorter wavelength data; the spatially variable PAH emission
strengths revealed by the IRS data suggest caution in the interpretation of
diffuse 8 micron emission as arising from PAH carriers alone. The metallicity
of NGC 1705 falls at the transition level of 35% solar found by Engelbracht and
collaborators; the fact that a system at this metallicity shows spatially
variable PAH emission demonstrates the complexity of interpreting diffuse 8
micron emission. A radio continuum non-detection, NGC 1705 deviates
significantly from the canonical far-IR vs. radio correlation. (Abridged)Comment: ApJ, in press; please retrieve full-resolution version from
http://www.astro.wesleyan.edu/~cannon/pubs.htm
The Nature of Infrared Emission in the Local Group Dwarf Galaxy NGC 6822 As Revealed by Spitzer
We present Spitzer imaging of the metal-deficient (Z ~30% Z_sun) Local Group
dwarf galaxy NGC 6822. On spatial scales of ~130 pc, we study the nature of IR,
H alpha, HI, and radio continuum emission. Nebular emission strength correlates
with IR surface brightness; however, roughly half of the IR emission is
associated with diffuse regions not luminous at H alpha (as found in previous
studies). The global ratio of dust to HI gas in the ISM, while uncertain at the
factor of ~2 level, is ~25 times lower than the global values derived for
spiral galaxies using similar modeling techniques; localized ratios of dust to
HI gas are about a factor of five higher than the global value in NGC 6822.
There are strong variations (factors of ~10) in the relative ratios of H alpha
and IR flux throughout the central disk; the low dust content of NGC 6822 is
likely responsible for the different H alpha/IR ratios compared to those found
in more metal-rich environments. The H alpha and IR emission is associated with
high-column density (> ~1E21 cm^-2) neutral gas. Increases in IR surface
brightness appear to be affected by both increased radiation field strength and
increased local gas density. Individual regions and the galaxy as a whole fall
within the observed scatter of recent high-resolution studies of the radio-far
IR correlation in nearby spiral galaxies; this is likely the result of depleted
radio and far-IR emission strengths in the ISM of this dwarf galaxy.Comment: ApJ, in press; please retrieve full-resolution version from
http://www.astro.wesleyan.edu/~cannon/pubs.htm
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