3,821 research outputs found
Feasibility of Using Cryostored Colorado Potato Beetle (Coleoptera: Chrysomelidae) Eggs for Rearing \u3ci\u3eEdovum Puttleri\u3c/i\u3e (Hymenoptera: Eulophidae)
Cryostored eggs of Colorado potato beetle, Leptinotarsa decemlineata (Say) eggs were suitable hosts for Edovum puttleri. Parasitism rates were low, however this study was first to show that rearing the parasite on eggs stored at ultra low temperatures (-70 0 C) is feasible. This method of storage will facilitate mass production of E. puttleri as well as prevent loss of the parasite in the event of a crash in the Colorado potato beetle colony
Feasibility of Using Cryostored Colorado Potato Beetle (Coleoptera: Chrysomelidae) Eggs for Rearing \u3ci\u3eEdovum Puttleri\u3c/i\u3e (Hymenoptera: Eulophidae)
Cryostored eggs of Colorado potato beetle, Leptinotarsa decemlineata (Say) eggs were suitable hosts for Edovum puttleri. Parasitism rates were low, however this study was first to show that rearing the parasite on eggs stored at ultra low temperatures (-70 0 C) is feasible. This method of storage will facilitate mass production of E. puttleri as well as prevent loss of the parasite in the event of a crash in the Colorado potato beetle colony
Zeta Potential Measurement and Particle Size Analysis for a Better Understanding of Urinary Inhibitors of Calcium Oxalate Crystallization
To better understand urinary inhibitors of calcium oxalate crystallization, both zeta potential measurement and particle size analysis were chosen to illustrate: (1) the potential therapeutic efficacy of G872, a semi-synthetic sulfated polysaccharide, in stone prevention; and (2) the relative contribution of various urinary fractions {e.g., ultrafiltered urine (UFU), Tamm-Horsfall protein (THP), urinary polyanionsprecipitated with cetylpyridinium chloride (CPC), urinary macromolecular substances with different concentration ratios (UMSl0,50,90 and UMS\u27l0,50,90) and THP-free urine (THPFU)} to total urinary inhibitory activity. The results showed: (1) addition of G872 significantly enhances urinary inhibitory activity and negative zeta potential values; (2) re-addition of the CPC to UFU completely restores urinary inhibitory activity; and (3) artificial urines prepared by mixing UMS\u27 10,50,90 from THPFU with UFU differed in inhibitory activity from that prepared by mixing UMSl0,50,90 from a pooled normal urine with UFU. Based on these experimental results, the following speculations can be made: (1) normal human urines are considered to be a protective colloidal system; (2) urinary inhibitory activity originates mainly from CPC and/or UMS; (3) normal THP is a protective material to maintain urinary inhibitory activity; and (4) mutual interaction between urinary inhibitors may change the total urinary inhibitory activity
The stellar dynamics and mass of NGC 1316 using the radial velocities of planetary nebulae
We present a study of the kinematics of the outer regions of the early-type
galaxy NGC 1316, based on radial velocity measurements of 43 planetary nebulae
as well as deep integrated-light absorption line spectra. The smoothed velocity
field of NGC 1316 indicates fast rotation at a distance of 16 kpc, possibly
associated with an elongated feature orthogonal to the inner dust lanes. The
mean square stellar velocity is approximately independent of radius, and the
estimated total mass of the system is 2.6 x 10^11 M_sun within a radius of 16
kpc, implying an integrated mass-to-light ratio of M/L_B = 8.Comment: 39 pages, 14 figures, in press on The Astrophysical Journal n. 50
Pathological and Immunocytochemical Changes in Chronic Calcium Oxalate Nephrolithiasis in the Rat
In the present study, we exposed rats to a crystal-inducing diet (CID) consisting of vitamin D3 and 0.5% ethylene glycol (EG), and we investigated histologically the kidney damage induced by the deposition of calcium oxalate (CaOx) crystals. After 28 days, 50 % of the animals had renal CaOx crystals, of which 60% also had small papillary stones. Most crystals were present in the cortex. The occurrence of these crystals coincided with morphological and cytochemical changes: glomerular damage, tubular dilatation and necrosis, and an enlargement of the interstitium. The number of epithelial and interstitial cells positive for the proliferating cell nuclear antigen (PCNA) was increased. Tamm-Horsfall protein (THP) was not only demonstrable in the thick ascending limb of the loop of Henle (TAL), but also frequently in glomeruli, in the proximal tubular epithelium, and in the papilla. In the lumen of the tubular system, it was associated with urinary casts. Reflection contrast microscopy (RCM) showed that the crystals were coated with a thin layer of THP. In spite of the high urinary oxalate concentrations, the above described cellular changes were not observed in CID-fed rats without renal crystals. We conclude, therefore, that in the kidney, the retained CaOx crystals rather than the urinary oxalate ions are responsible for the observed morphological and immunocytochemical changes
Lectin-Cytochemistry of Experimental Rat Nephrolithiasis
Lectin reactivity in epithelial apical cell coats of normal rat kidneys was compared to that from animals subjected to crystal inducing diets (CID). The aim was to see whether the absence of lectin reactivity in cell coats is related to intratubular calcium oxalate crystal retention. In normal rat kidneys, after a pre-embedding procedure, it was observed that at the ultrastructural level, reactivity was present but that the lectin specificity for the various parts of the nephron might have to be reconsidered. There was heterogeneity between the epithelial cells with respect to the presence of coat material in the tubular cell apices. Tubular epithelial cell apices from CID rats showed no obvious changes in lectin reactivity pattern. Lectin reactivity was present at the periphery of intratubular crystals but undetectable at true crystal attachment sites or reduced at cell apices in the vicinity of recently attached crystals or agglomerates.
After a post-embedding reaction procedure, wheat-germ agglutinin (WGA)-lectin reactivity confirmed the presence of coat material in the cleft between cell apex and retained crystal at crystal-attachment sites. The WGA/Au-10 nm reaction products were also seen inside epithelial cells. WGA/Au-10 nm reaction products mark a crystal matrix component inside intratubular and re-tained crystals. A similar matrix was also marked by an α-osteopontin ( αOPN/Au-10 nm) reaction product
Simultaneous X-Ray and TeV Gamma-Ray Observations of the TeV Blazar Markarian 421 during February and May 2000
In this paper we present the results of simultaneous observations of the TeV
blazar Markarian 421 (Mrk 421) at X-ray and TeV Gamma-ray energies with the
Rossi X-Ray Timing Explorer (RXTE) and the stereoscopic Cherenkov Telescope
system of the HEGRA (High Energy Gamma Ray Astronomy) experiment, respectively.
The source was monitored from February 2nd to February 16th and from May 3rd to
May 8th, 2000. We discuss in detail the temporal and spectral properties of the
source. Remarkably, the TeV observations of February 7th/8th showed
statistically significant evidence for substantial TeV flux variability on 30
min time scale. We show the results of modeling the data with a time dependent
homogeneous Synchrotron Self-Compton (SSC) model. The X-ray and TeV gamma-ray
emission strengths and energy spectra together with the rapid flux variability
strongly suggest that the emission volume is approaching the observer with a
Doppler factor of 50 or higher. The different flux variability time scales
observed at X-rays and TeV Gamma-rays indicate that a more detailed analysis
will require inhomogeneous models with several emission zones.Comment: Accepted for Publication in ApJ, 21 Pages, 5 Figure
HI Bright Galaxies in the Southern Zone of Avoidance
A blind survey for HI bright galaxies in the southern Zone of Avoidance, (212
deg < l < 36 deg; |b| < 5 deg), has been made with the 21 cm multibeam receiver
on the Parkes 64 m radiotelescope. The survey, sensitive to normal spiral
galaxies to a distance of about 40 Mpc and more nearby dwarfs, detected 110
galaxies. Of these, 67 have no counterparts in the NASA/IPAC Extragalactic
Database. In general, the uncataloged galaxies lie behind thicker obscuration
than do the cataloged objects. All of the newly-discovered galaxies have HI
flux integrals more than an order of magnitude lower than the Circinus galaxy.
The survey recovers the Puppis cluster and foreground group (Kraan-Korteweg &
Huchtmeier 1992), and the Local Void remains empty. The HI mass function
derived for the sample is satisfactorily fit by a Schechter function with
parameters alpha = 1.51 +- 0.12, Phi* = 0.006 +- 0.003, and log M* = 9.7 +-
0.10.Comment: To appear in The Astronomical Journa
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