747 research outputs found
Reaction of Alpine-Borane with Aldehydes: Reactivity Rate Assessment by Observation of the Disappearance of the Carbonyl n - Pi* Peak by UV-Visible Spectroscopy
Due to an unexpectedly difficult reduction of indole-3-carbaldehyde and of isobutyraldehyde using the chiral reducing agent Alpine-Borane, the reactivity of several aliphatic, aromatic, and unsaturated aldehydes was investigated. This was done in order to determine whether there was a relationship between aldehyde structure and reduction rate. It was found that aliphatic aldehydes and aromatic aldehydes with no strongly electron-donating groups on the arene ring reduced faster than unsaturated aldehydes
Ecological characterization of the Florida springs coast: Pithlachascotee to Waccasassa Rivers
This report covers the upper coast of west-central Florida. This region includes the drainage basins and nearshore waters of the west coast of Florida between, but not including, the Anclote River basin and the Suwannee River basin. The name Springs Coast wash chosen because this area contains a multitude of springs, both named and too small or inaccessible to have been names. Much of the area is karstic limestone. Most recognizable among the springs are the famous Crystal river, Weeki Wachee, and Homosassa. This territory includes large expanses of
marsh and wetland and, along its shores, the southern end of the largest area of seagrass beds in the state -- the Florida Big Bend Seagrass Beds preserve. It also possesses numerous spring-fed rivers and streams along the coast, whose constant discharges provide unique, relatively stable estuarine environments. This document is a summary of the available
information on the Springs Coast area of Florida, for
use by planners, developers, regulatory authorities,
and other interested parties. An understanding of the
factors affecting their plans and the possibly unexpected
impacts of their actions on others will, it is
hoped, promote intelligent development in areas
capable of supporting it. We have tried to provide a
clear, coherent picture of what is currently known
about how the physical, chemical, and biological
factors of the environment interact. (343 pp.
Discovery of a 500 pc shell in the nucleus of Centaurus A
Spitzer Space Telescope mid-infrared images of the radio galaxy Centaurus A
reveal a shell-like, bipolar, structure 500 pc to the north and south of the
nucleus. This shell is seen in 5.8, 8.0 and 24 micron broad-band images. Such a
remarkable shell has not been previously detected in a radio galaxy and is the
first extragalactic nuclear shell detected at mid-infrared wavelengths. We
estimate that the shell is a few million years old and has a mass of order
million solar masses. A conservative estimate for the mechanical energy in the
wind driven bubble is 10^53 erg. The shell could have created by a small few
thousand solar mass nuclear burst of star formation. Alternatively, the
bolometric luminosity of the active nucleus is sufficiently large that it could
power the shell. Constraints on the shell's velocity are lacking. However, if
the shell is moving at 1000 km/s then the required mechanical energy would be
100 times larger.Comment: submitted to ApJ Letter
Reply to Rob Smeetsâ letter to the editor regarding the article âA comparison of the relationship between depression, perceived disability, and physical performance in persons with chronic painâ (2008)
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90330/1/j.ejpain.2008.08.007.pd
The Wide Field Spectrograph (WiFeS)
This paper describes the Wide Field Spectrograph (WiFeS) under construction
at the Research School of Astronomy and Astrophysics (RSAA) of the Australian
National University (ANU) for the ANU 2.3m telescope at the Siding Spring
Observatory. WiFeS is a powerful integral field, double-beam, concentric,
image-slicing spectrograph designed to deliver excellent thoughput, wavelength
stability, spectrophotometric performance and superb image quality along with
wide spectral coverage throughout the 320-950 nm wavelength region. It provides
a 25x38 arcsec. field with 0.5 arcsec. sampling along each of twenty five 38X1
arcsec slitlets. The output format is optimized to match the 4096x4096 pixel
CCD detectors in each of two cameras individually optimized for the blue and
the red ends of the spectrum, respectively. A process of "interleaved
nod-and-shuffle" will be applied to permit quantum noise-limited sky
subtraction. Using VPH gratings, spectral resolutions of 3000 and 7000 are
provided. The full spectral range is covered in a single exposure at R=3000,
and in two exposures in the R=7000 mode. The use of transmissive coated optics,
VPH gratings and optimized mirror coatings ensures a throughput (including
telescope atmosphere and detector) > 30% over a wide spectral range. The
concentric image-slicer design ensures an excellent and uniform image quality
across the full field. To maximize scientific return, the whole instrument is
configured for remote observing, pipeline data reduction, and the accumulation
of calibration image libraries.Comment: Accepted for publication in Astrophysics & Space Science, 16 pages,
14 figure
Sodium-glucose cotransporter 2 inhibitor effects on heart failure hospitalization and cardiac function: systematic review
Aims:
To systematically review randomized controlled trials assessing effects of sodiumâglucose cotransporter 2 inhibitors (SGLT2is) on hospitalization for heart failure (HHF) and cardiac structure/function and explore randomized controlled trial (RCT)-derived evidence for SGLT2i efficacy mechanisms in heart failure (HF).
Methods and results:
Systematic searches of Medline and Embase were performed. In seven trials [3730â17 160 patients; low risk of bias (RoB)], SGLT2is significantly reduced the relative risk of HHF by 27â39% vs. placebo, including in two studies in patients with HF with reduced ejection fraction with or without type-2 diabetes mellitus (T2DM). Improvements in conventional cardiovascular risk factors, including glycaemic levels, cannot account for these effects. Five trials (56â105 patients; low RoB) assessed the effects of 6â12 months of SGLT2i treatment on left ventricular structure/function; four reported significant improvements vs. placebo, and one did not. Five trials (low RoB) assessed SGLT2i treatment effects on serum N-terminal pro B-type natriuretic peptide levels; significant reductions vs. placebo were reported after 8â12 months (two studies; 3730â4744 patients) but not â€12 weeks (three studies; 80â263 patients). Limited available RCT-derived evidence suggests various possible cardioprotective SGLT2i mechanisms, including improved haemodynamics (natriuresis and reduced interstitial fluid without blood volume contraction/neurohormonal activation) and vascular function, enhanced erythropoiesis, reduced tissue sodium and epicardial fat/inflammation, decreased sympathetic tone, and beneficial changes in cellular energetics.
Conclusions:
Sodiumâglucose cotransporter 2 inhibitors reduce HHF regardless of T2DM status, and reversal of adverse left ventricular remodelling likely contributes to this efficacy. Hypothesis-driven mechanistic trials remain sparse, although numerous trials are planned or ongoing
Systematic review of the effects of sodium-glucose cotransporter 2 inhibitors on hospitalization for heart failure and cardiac structure or function, and exploratory assessment of potential mechanisms
In the past 5 years, there has been a profound shift in the therapeutic focus of trials of sodium-glucose cotransporter 2 inhibitors (SGLT2is).
Although initially explored and introduced as glucose-lowering agents for patients with type 2 diabetes mellitus (T2DM), 1 clinical investigation of these molecules has evolved towards heart failure (HF) and chronic kidney disease (CKD) outcomes in patients with and without T2DM.
We systematically reviewed randomized controlled trial (RCT) data assessing the effects of SGLT2 is compared with placebo on hospitalization for HF (HHF), cardiac structure and cardiac function, in a PRISMA-compliant manner.
We also reviewed, in an exploratory manner, mechanistic evidence for how SGLT2 is may exert their benefits
Synthesis and evaluation of human phosphodiesterases (PDE) 5 inhibitor analogs as trypanosomal PDE inhibitors. 2. Tadalafil analogs
Author Posting. © The Author(s), 2012. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Bioorganic & Medicinal Chemistry Letters 22 (2012): 2582-2584, doi:10.1016/j.bmcl.2012.01.118.In this report we describe our ongoing target repurposing efforts focused on discovery of inhibitors of the essential trypanosomal phosphodiesterase TbrPDEB1. This enzyme has been implicated in virulence of Trypanosoma brucei, the causative agent of human African trypanosomiasis (HAT). We outline the synthesis and biological evaluation of analogs of tadalafil, a human PDE5 inhibitor currently utilized for treatment of erectile dysfunction, and report that these analogs are weak inhibitors of TbrPDEB1.This work was supported by the National Institutes of Health (R01AI082577), Boston University and Northeastern University
The SAMI Galaxy Survey: Shocks and Outflows in a normal star-forming galaxy
We demonstrate the feasibility and potential of using large integral field
spectroscopic surveys to investigate the prevalence of galactic-scale outflows
in the local Universe. Using integral field data from SAMI and the Wide Field
Spectrograph, we study the nature of an isolated disk galaxy, SDSS
J090005.05+000446.7 (z = 0.05386). In the integral field datasets, the galaxy
presents skewed line profiles changing with position in the galaxy. The skewed
line profiles are caused by different kinematic components overlapping in the
line-of-sight direction. We perform spectral decomposition to separate the line
profiles in each spatial pixel as combinations of (1) a narrow kinematic
component consistent with HII regions, (2) a broad kinematic component
consistent with shock excitation, and (3) an intermediate component consistent
with shock excitation and photoionisation mixing. The three kinematic
components have distinctly different velocity fields, velocity dispersions,
line ratios, and electron densities. We model the line ratios, velocity
dispersions, and electron densities with our MAPPINGS IV shock and
photoionisation models, and we reach remarkable agreement between the data and
the models. The models demonstrate that the different emission line properties
are caused by major galactic outflows that introduce shock excitation in
addition to photoionisation by star-forming activities. Interstellar shocks
embedded in the outflows shock-excite and compress the gas, causing the
elevated line ratios, velocity dispersions, and electron densities observed in
the broad kinematic component. We argue from energy considerations that, with
the lack of a powerful active galactic nucleus, the outflows are likely to be
driven by starburst activities. Our results set a benchmark of the type of
analysis that can be achieved by the SAMI Galaxy Survey on large numbers of
galaxies.Comment: 17 pages, 15 figures. Accepted to MNRAS. References update
The effect of behind-the-scenes encounters and interactive presentations on the welfare of captive servals (Leptailurus serval)
The serval (Leptailurus serval) is a small African felid that is well represented in zoos and often serves as an animal ambassador in encounter programs with zoo visitors. The impact on serval welfare in relation to such programs has not been investigated to date, and the aim of this study was to assess short-term welfare effects of varying levels of visitor interaction in two captive servals. Weekly blocks of four different treatments were imposed three times on each animal over 12 weeks, and the treatments involved (1) Presentations (serval undertaking a routine training session in a designated presentation space, typically attracting high visitor numbers), (2) Behind-the-scenes (BTS, a close encounter allowing a small group of visitors to interact closely with the cat in its enclosure), (3) Presentations and BTS combined, and (4) No visitor interaction. Serval activity budgets as well as behavioural diversity were created from behaviours observed from Close Circuit Television (CCTV) footage during four daily recording sessions per animal over three consecutive days per treatment, using instantaneous scan sampling every 60 s. Individual faecal samples were collected daily to monitor changes in faecal glucocorticoid metabolite (FGM) concentration. Results indicate that the mean number of scans with stereotypic pacing was significantly reduced (p = 0.01) during Treatments 1 and 3, when cats participated in presentations only, or the two activities combined. Conversely, a significant reduction in behavioural diversity (p 0.05). Given the reduction in stereotypic pacing, these findings suggest that involvement in an encounter program appears to exert an overall positive short-term welfare effect on the individual servals in this study. Although a reduction in behavioural diversity was not considered a negative welfare effect in the short term, potential long-term negative welfare effects resulting from a more frequent encounter program could not be ruled out in the present study
- âŠ