203 research outputs found
House Musk Shrews (Suncus murinus) Do Not Copulate in the Light Period when First Paired in the Dark
The copulatory behavior pattern of house musk shrews paired for 24 h starting at either 09:00 (light) or 20:00 (dark) was investigated. Ejaculatory behaviors were observed in both light and dark periods, when mating was started at 09:00. However, the males ejaculated only in the dark period when they were paired at 20:00
Strain differences in pubertal development of male ratsâ penile reflexes
The penile reflexes in outbrcd Wistar, SD and inbred Fischer strain male rats aged from 23 to 62 days were observed for 15 min following sheath retraction. Plasma Luteinizing hormone (LH) and testosterone levels were measured at 23, 37, 51and 70 days of age by RIA. All Wistar and SD rats displayed erection: cups and flips before plasma LH and testosterone levels peaked at 51 days of age, whereas in Fischer strain males, erections, flips, but not cups began to be seen around peak levels of these hormones at 51 days of age. The pubertal development of penile reflexes in Fischer strain males was slower than that in Wistar and SD Stocks. The present study is the first to clarify the strain differences in pubertal development of male ratsâ penile reflexes
Effects of rat- prolactin 0n ingestive behavior and leptin levels in adult male rats
Previous studies have indicated that ovine- or bovine-prolactin stimulates ingestive behavior in female, but not in male rats; i.e., that prolactin has sex-specific effects on ingestive behavior. The question addressed here was whether ingestivebehavior in male rats would be induced by rat-prolactin. In a preliminary test male rats were allowed to ingest a 1 M solution of sucrose from a drinking spout. After daily intake of sucrose became stabilized, the males received rat-prolactin by pituitary grafting. The results showed that pituitary grafling both stimulates ingestive behavior and increases serum leptin levels in male rats. These findings coupled with previous findings suggest that proinctin has species-specific effects on ingestivc behavior
Age-Related Changes in the Penile Reflex of Rats
The penile reflex in sexually experienced male rats aged 10 and 44 weeks was observed for 20 min following sheath retraction. All 7 males aged 10 weeks showed erections, cups arid flips, while of 5 males aged 44 weeks only 2 showed erections.Frequencies of the above behaviors in aged males were significantly lower than that in young males. The decrease of penile reflexes with aging was similar to that of copulatory behavior with aging, when paired with receptive females. The presentstudy is the first to clearly establish the pattern of penile reflexes in aged rats
Copulatory behavior of male house musk shrews (Suncus murinus)
The copulatory behavior in male house musk shrews (Jic: SUN strain) aged 10-12 months was observed under the light (09:00-11:00) and dark (20:00-22:00) periods. The females of same strain were used as stimulus in copulatory behavior tests.Two-hour test sessions were recorded. All 14 males showed one ejaculation after a few intromissions within 2 hours. These values are similar to that of male guinea pigs. Comparing behavioral frequencies and latencies for males observed in thelight and dark periods, there were no significant differences between two groups. The present study is the first to clearly establish the pattern of copulatory behavior in male house musk shrews
High-Resolution Submillimeter and Near-Infrared Studies of the Transition Disk around Sz 91
To reveal the structures of a transition disk around a young stellar object
in Lupus, Sz 91, we have performed aperture synthesis 345 GHz continuum and
CO(3--2) observations with the Submillimeter Array (\sim1\arcsec--3\arcsec
resolution), and high-resolution imaging of polarized intensity at the
-band by using the HiCIAO instrument on the Subaru Telescope (0\farcs25
resolution). Our observations successfully resolved the inner and outer radii
of the dust disk to be 65 AU and 170 AU, respectively, which indicates that Sz
91 is a transition disk source with one of the largest known inner holes. The
model fitting analysis of the spectral energy distribution reveals an H
mass of M_\sun in the cold (30 K) outer part at
AU by assuming a canonical gas-to-dust mass ratio of 100, although a
small amount ( M_\sun) of hot (180 K) dust possibly
remains inside the inner hole of the disk. The structure of the hot component
could be interpreted as either an unresolved self-luminous companion body (not
directly detected in our observations) or a narrow ring inside the inner hole.
Significant CO(3--2) emission with a velocity gradient along the major axis of
the dust disk is concentrated on the Sz 91 position, suggesting a rotating gas
disk with a radius of 420 AU. The Sz 91 disk is possibly a rare disk in an
evolutionary stage immediately after the formation of protoplanets because of
the large inner hole and the lower disk mass than other transition disks
studied thus far
Collective Thomson scattering with 77, 154, and 300 GHz sources in LHD
Collective Thomson scattering (CTS) is one of attractive diagnostics for measuring locally and directly the fuel temperature and the velocity distribution of fast ions in fusion plasmas. A mega-watt class source of millimeter or sub-millimeter waves is required to detect a weak scattered radiation superimposed on background radiation owing to electron cyclotron emissions (ECEs) from plasmas. Based on electron cyclotron resonance heating (ECRH) system with the frequencies of 77 GHz and 154 GHz in the Large Helical Device (LHD), the CTS diagnostic system has been developed to measure bulk ion temperatures from a few keV to âŒ10 keV and fast ions originated from 180 keV-neutral beam injection in the LHD. The measured CTS spectra and their time evolutions are analyzed with the electrostatic scattering theory. The bulk ion temperatures obtained from CTS spectra increase with the neutral beam injections and decrease with the heating terminated. The velocity map of simulated fast ions explains that the bumps on tail of measured CTS spectra are caused by the co- and counter- fast ions. A new prescription for anisotropic velocity distribution function is proposed. As for 154 GHz bands, the CTS spectrum broadenings for D and H plasmas are distinguished reasonably at the same temperature, and its ion temperatures are comparable to those of the charge exchange recombination spectroscopy. As reactor-relevant diagnostics, a 300 GHz gyrotron and a corresponding receiver system have been implemented in LHD to access high density plasmas with low background ECEs. The recent progress for CTS diagnostics and their spectrum analysis with the probe frequencies of 77 GHz, 154 GHz, and 300 GHz in the LHD experiments is described
Mutational analysis of xenobiotic metabolizing genes (CYP1A1 and GSTP1) in sporadic head and neck cancer patients
CYP1A1 is the phase I enzyme that detoxifies the carcinogen or converts it into a more electrophilic form, metabolized by phase II enzymes like GSTP1. These detoxifying genes have been extensively studied in association with head and neck cancer (HNC) in different ethnic groups worldwide. The current study was aimed at screening genetic polymorphisms of genes CYP1A1 and GSTP1 in 388 Pakistani HNC patients and 150 cancer-free healthy controls, using PCR-SSCP. No already known variants of either gene were found, however a novel frameshift mutation due to insertion of T (g.2842_2843insT) was observed in the CYP1A1 gene. A statistically significant number (5.4%) of HNC cases, with the mean age of 51.75 (±15.7) years, presented this frameshift mutation in the conserved domain of CYP1A1. Another novel substitution mutation in was found in the GSTP1 gene, presenting TA instead of AG. The g.2848A > T polymorphism causes a leucine-to-leucine formation, whereas g.2849G > A causes alanine-to-threonine formation at amino acid positions 166 and 167, respectively. These exonic mutations were found in 9.5% of the HNC patients and in none of the controls. In addition, two intronic deletions of C (g.1074delC and g.1466delC) were also found in 11 patients with a mean age of 46.2 (±15.6) years. In conclusion, accumulation of mutations in genes CYP1A1 and GSTP1 appears to be associated with increased risk of developing HNC, suggesting that mutations in these genes may play a role in the etiology of head and neck cancer
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