Biology of Stonecat, Noturus flavus (Siluriformes: Ictaluridae), in Central Illinois and Missouri Streams, and Comparisons with Great Lakes Populations and Congeners

Author Institution: Department of Zoology and The Florida State Museum, University of Florida ; Department of Zoology, Southern Illinois University at CarbondaleAspects of the general biology of the stonecat, Noturusflavus, were analyzed from 261 preserved specimens from Illinois and Missouri streams. Individuals ranged in age from one to 62 mo. The largest specimens examined were a 180-mm SL male and a 165-mm SL female. Females were mature at 3-4 yr and a mean SL of 119.4 mm. Mature oocytes, produced seasonally, ranged from 189 to570(x = 377.8; N = 12) per female. Seven nests, each containing a clutch of embryos or larvae and guarded by a male, were found under large, flat rocks in pools and riffles. All nest-guarding males were 3 yr old and ranged from 87 to 105 mm SL (x = 94.8). Nests were observed in early July at water temperatures of 27 to 29°C. Clutch sizes ranged from 104 to 306+; embryos were spherical, opaque white or light yellow, and ranged in diameter from 2.6 to 4.0 mm (x = 3.4 mm; N = 40). At hatching, mesolarvae ranged from 6.7 to 7.5 mm TL; development was similar to that described for other ictalurids. Stomachs of adults contained a variety of benthic organisms, primarily aquatic larval insects and decapod crustaceans

Distinctive ECG patterns in healthy black adults

Six ECG patterns are found more frequently in healthy black adults than in whites. These patterns are presumably benign, but also may resemble those of malignant disease. 1) Healthy black adults show higher QRS voltage, and more often meet ECG criteria for left ventricular hypertrophy (LVH). Associated repolarization abnormalities can produce ST segment elevation (STE) that resembles ST elevation MI (STEMI). 2) The pattern of benign anterior STE, seen often in males, is more common in black subjects. Similar to LVH, this pattern may falsely suggest STEMI. 3) Both early repolarization (ER) and benign inferolateral STE are more common in black patients. Although they may convey a higher risk of fatal arrhythmias or cardiac death in white populations, it does not appear that black subjects with these patterns show a similar risk. 4) The persistent juvenile T wave inversion pattern shows asymmetric T wave inversion (TWI) in V1-V4, without ST segment deviations. It is most common in black females, and is considered benign. However, this pattern can also resemble the anterior TWI of arrhythmogenic right ventricular cardiomyopathy (ARVC). 5) A pattern of anterior TWI with associated J point elevation is a common finding in the black population, especially athletes. It could suggest hypertrophic cardiomyopathy, but can be presumed to be a benign finding in black athletes, when TWI is limited to V1-V4 and preceded by J point elevation. 6) TWI in the lateral precordial leads, usually associated with end-QRS slurring or notches is seen much more often in apparently healthy black subjects than white subjects. Unlike the anterior TWI pattern, however, it cannot be presumed benign. In conclusion, awareness of these ECG patterns may help to avoid unnecessary diagnostic or therapeutic interventions, but also encourage appropriate investigations

Distinctive ECG patterns in healthy black adults

Six ECG patterns are found more frequently in healthy black adults than in whites. These patterns are presumably benign, but also may resemble those of malignant disease. 1) Healthy black adults show higher QRS voltage, and more often meet ECG criteria for left ventricular hypertrophy (LVH). Associated repolarization abnormalities can produce ST segment elevation (STE) that resembles ST elevation MI (STEMI). 2) The pattern of benign anterior STE, seen often in males, is more common in black subjects. Similar to LVH, this pattern may falsely suggest STEMI. 3) Both early repolarization (ER) and benign inferolateral STE are more common in black patients. Although they may convey a higher risk of fatal arrhythmias or cardiac death in white populations, it does not appear that black subjects with these patterns show a similar risk. 4) The persistent juvenile T wave inversion pattern shows asymmetric T wave inversion (TWI) in V1-V4, without ST segment deviations. It is most common in black females, and is considered benign. However, this pattern can also resemble the anterior TWI of arrhythmogenic right ventricular cardiomyopathy (ARVC). 5) A pattern of anterior TWI with associated J point elevation is a common finding in the black population, especially athletes. It could suggest hypertrophic cardiomyopathy, but can be presumed to be a benign finding in black athletes, when TWI is limited to V1-V4 and preceded by J point elevation. 6) TWI in the lateral precordial leads, usually associated with end-QRS slurring or notches is seen much more often in apparently healthy black subjects than white subjects. Unlike the anterior TWI pattern, however, it cannot be presumed benign. In conclusion, awareness of these ECG patterns may help to avoid unnecessary diagnostic or therapeutic interventions, but also encourage appropriate investigations

The Giant Pillars of the Carina Nebula

Results are presented from a multi-wavelength study of the giant pillars within the Carina Nebula. Using near-IR data from 2MASS, mid-IR data from MSX, 843MHz radio continuum maps from the MOST, and molecular line and continuum observations from the SEST, we investigate the nature of the pillars and search for evidence of ongoing star formation within them. Photodissociation regions (PDRs) exist across the whole nebula and trace the giant pillars, as well as many ridges, filaments, and condensations (Av > 7 mag). Morphological similarities between emission features at 21um and 843MHz adjacent to the PDRs, suggests that the molecular material has been carved by the intense stellar winds and UV radiation from the nearby massive stars. In addition, star forming cores are found at the tips of several of the pillars. Using a stellar density distribution, several candidate embedded clusters are also found. One is clearly seen in the 2MASS images and is located within a dense core (G287.84-0.82). A search for massive young stellar objects and compact HII regions using mid-IR colour criteria, reveal twelve candidates across the complex. Grey-body fits to SEDs for four of these objects are suggestive of OB-stars. We find that massive star formation in the Carina Nebula is occurring across the whole complex and confirm it has been continuous over the past 3 Myrs.Comment: 14 pages, 10 figures (low resolution), accepted by A&

Photodissociation regions and star formation in the Carina Nebula

We have obtained wide-field thermal infrared (IR) images of the Carina Nebula, using the SPIREX/Abu telescope at the South Pole. Emission from poly-cyclic aromatic hydrocarbons (PAHs) at 3.29um, a tracer of photodissociation regions (PDRs), reveals many interesting well defined clumps and diffuse regions throughout the complex. Near-IR images (1--2um), along with images from the Midcourse Space Experiment (MSX) satellite (8--21um) were incorporated to study the interactions between the young stars and the surrounding molecular cloud in more detail. Two new PAH emission clumps have been identified in the Keyhole Nebula and were mapped in 12CO(2--1) and (1--0) using the SEST. Analysis of their physical properties reveals they are dense molecular clumps, externally heated with PDRs on their surfaces and supported by external pressure in a similar manner to the other clumps in the region. A previously identified externally heated globule containing IRAS 10430-5931 in the southern molecular cloud, shows strong 3.29-, 8- and 21-um emission, the spectral energy distribution (SED) revealing the location of an ultra-compact (UC) HII region. The northern part of the nebula is complicated, with PAH emission inter-mixed with mid-IR dust continuum emission. Several point sources are located here and through a two-component black-body fit to their SEDs, we have identified 3 possible UC HII regions as well as a young star surrounded by a circumstellar disc. This implies that star formation in this region is on-going and not halted by the intense radiation from the surrounding young massive stars.Comment: 14 pages, 12 figures. Accepted by MNRAS. Higher resolution figures available at http://www.phys.unsw.edu.au/~jmr/papers.htm

Multibeam Maser Survey of methanol and excited OH in the Magellanic clouds: new detections and maser abundance estimates

‘The definitive version is available at www.blackwell-synergy.com.’ Copyright Blackwell Publishing DOI: 10.1111/j.1365-2966.2008.12888.xPeer reviewe

Two massive star-forming regions at early evolutionary stages

We report sensitive ATCA radio-continuum observations toward IRAS 15596-5301 and 16272-4837, two luminous objects (> 2x10^4 Lsun) thought to represent massive star-forming regions in early stages of evolution (due to previously undetected radio emission at the 1-sigma level of 2 mJy per beam). Also reported are 1.2-millimeter continuum and a series of molecular-line observations made with the SEST telescope. For IRAS 15596-5301, the observations reveal the presence of three distinct compact radio-continuum sources associated with a dense molecular core. We suggest that this core contains a cluster of B stars which are exciting compact HII regions that are in pressure equilibrium with the dense molecular surroundings. No radio continuum emission was detected from IRAS 16272-4837 (3-sigma limit of 0.2 mJy). However, a dense molecular core has been detected. The high luminosity and lack of radio emission from this massive core suggests that it hosts an embedded young massive protostar that is still undergoing an intense accretion phase. This scenario is supported by the observed characteristics of the line profiles and the presence of a bipolar outflow detected from observations of the SiO emission. We suggest that IRAS 16272-4837 is a bona fide massive star- forming region in a very early evolutionary stage, being the precursor of an ultra compact HII region.Comment: 25 pages, 9 figures, accepted for publication in The Astrophysical Journa

ATCA 3mm observations of NGC6334I and I(N): dense cores, outflows and an UCHII region

Aims: Investigation of the dense gas, the outflows and the continuum emission from the massive twin cores NGC6334I and I(N) at high spatial resolution. Methods: We imaged the region with the Australia Telescope Compact Array (ATCA) at 3.4mm wavelength in continuum as well as CH3CN(5_K-4_K) and HCN(1-0) spectral line emission. Results: While the continuum emission in NGC6334I mainly traces the UCHII region, toward NGC6334I(N) we detect line emission from four of the previously identified dust continuum condensations that are of protostellar or pre-stellar nature. The CH3CN(5_K-4_K) lines are detected in all K-components up to energies of 128K above ground toward two protostellar condensations in both regions. We find line-width increasing with increasing K for all sources, which indicates a higher degree of internal motions closer to the central protostars. Toward the main mm and CH3CN source in NGC6334I we identify a velocity gradient approximately perpendicular to the large-scale molecular outflow. This may be interpreted as a signature of an accretion disk, although other scenarios, e.g., an unresolved double source, could produce a similar signature as well. No comparable signature is found toward any of the other sources. HCN does not trace the dense gas well but it is dominated by the molecular outflows. While the outflow in NGC6334I exhibits a normal Hubble-law like velocity structure, the data indicate a precessing outflow close to the plane of the sky for NGC6334I(N). Furthermore, we observe a wide (~15.4km/s) HCN absorption line, much broader than the previously observed CH3OH and NH3 absorption lines. Several explanations for the difference are discussed.Comment: 14 pages, 14 figures, accepted for A&

Molecular line survey of the high-mass star-forming region NGC 6334I with Herschel/HIFI and the SMA

We aim at deriving the molecular abundances and temperatures of the hot molecular cores in the high-mass star-forming region NGC 6334I and consequently deriving their physical and astrochemical conditions. In the framework of the Herschel guaranteed time key program CHESS, NGC 6334I is investigated by using HIFI aboard the Herschel Space Observatory. A spectral line survey is carried out in the frequency range 480-1907 GHz, and auxiliary interferometric data from the SMA in the 230 GHz band provide spatial information for disentangling the different physical components contributing to the HIFI spectrum. The spectral lines are identified with the aid of former surveys and spectral line catalogs. The observed spectrum is then compared to a simulated synthetic spectrum with XCLASS, assuming local thermal equilibrium, and best fit parameters are derived using the model optimization package MAGIX. A total of 46 molecules are identified, with 31 isotopologues, resulting in about 4300 emission and absorption lines. High- energy levels of the dominant emitter methanol and vibrationally excited HCN are detected. The number of unidentified lines remains low with 75, or less than 2 percent of the lines detected. The modeling suggests that several spectral features need two or more components to be fitted properly. Other components could be assigned to cold foreground clouds or to outflows, most visible in the SiO emission. A chemical variation between the two embedded hot cores is found, with more N-bearing molecules identified in SMA1 and O-bearing molecules in SMA2. Spectral line surveys give powerful insights into the study of the interstellar medium. Different molecules trace different physical conditions like the inner hot core, the envelope, the outflows or the cold foreground clouds. The derived molecular abundances provide further constraints for astrochemical models.Comment: 30 pages including appendix, 49 figures, accepted for publication in Astronomy and Astrophysic