Shortening of Subjective Visual Intervals Followed by Repetitive Stimulation

Our previous research demonstrated that repetitive tone stimulation shortened the perceived duration of the preceding auditory time interval. In this study, we examined whether repetitive visual stimulation influences the perception of preceding visual time intervals. Results showed that a time interval followed by a high-frequency visual flicker was perceived as shorter than that followed by a low-frequency visual flicker. The perceived duration decreased as the frequency of the visual flicker increased. The visual flicker presented in one hemifield shortened the apparent time interval in the other hemifield. A final experiment showed that repetitive tone stimulation also shortened the perceived duration of preceding visual time intervals. We concluded that visual flicker shortened the perceived duration of preceding visual time intervals in the same way as repetitive auditory stimulation shortened the subjective duration of preceding tones

Initial results of Husafell solar radio spectrograph

Observing the moon surface and subsurface materials using various radio frequencies is very important for investigating the physical properties of the moon. In particular, the frequency dependence of the dielectric constant of surface and subsurface materials provides information on the density profile. Because the dielectric constant is identified by measuring the reflectivity of the radio waves, we attempted to observe direct solar radio bursts in Iceland and reflected solar radio bursts in Iitate simultaneously. A new solar radio spectrograph to observe solar radio bursts has been installed at Husafell station in Iceland. The spectrograph covers two frequency bands in the ranges of 18MHz to 38MHz and 190MHz to 350MHz. Since September 2004, several successful observations have been made: 30 events of Type-I, -II, -III, and -IV bursts have been found in data obtained between September 2004 and August 2005. The flux density of the solar radio bursts detected in this study was within the range of 10 to 100s.f.u. We previously confirmed that when strong solar burst phenomena occur in the UHF range, the reflected wave signal from the moon surface can be detected using the Iitate Planetary Radio Telescope, installed in Japan

Effects of parity and season on pregnancy rates to Japanese Black beef cattle

Repeat-breeder (RB) cows are a major source of economic waste due to their decreased fertility. Embryo transfer (ET) is an alternative tool to improve the fertility of RB cows. The aims of the present study were to evaluate the effects of recipient parity and the season on pregnancy rates following ET in RB Japanese Black beef cattle. Embryos were transferred nonsurgically to recipients, consisting of 155 heifers (< 2 years old) and 172 cows (< 8 years old), which were defined as RB cattle. Of the recipients that were presented for ET, 57 recipients received a fresh embryo and 270 recipients received a frozen embryo. There were no differences in the pregnancy rates between cattle that received fresh embryos or frozen embryos. The rates of recipients with pregnancy, abortion, stillbirth, and normal calving were similar between heifers and cows. In cows, the pregnancy rates were lower (P < 0.05) in summer (June to August) than in spring (March to May) and winter (December to February). In heifers, however, there were no differences in the pregnancy rates among the seasons. Our findings indicate that in RB Japanese Black beef cattle, the parity of the recipients does not have an effect on the pregnancy rates following the transfer of fresh and frozen embryos. However, heat stress may affect reproductive performance in RB Japanese Black cows

Vaginal stimulation enhances ovulation of queen ovaries treated using a combination of eCG and hCG

Follicular changes throughout the oestrous phase have been poorly documented in queens because of the location and the small size of ovaries. We investigated follicular development in queens treated with a combination of equine chorionic gonadotropin (eCG) and human chorionic gonadotropin (hCG) and evaluated the effects of vaginal stimulation by a tomcat on ovulation induction. A hormonal treatment was administered using a simple crossover design. Four queens were administered 150 IU of eCG (day 1) and 250 IU of hCG on day 5 and 6. Half of the queens were mated with a vasectomised tomcat for 3 days after hCG injection. Ultrasound imaging of the ovaries clamped at a subcutaneous site was performed once a day from day 1 to 7, and on day 13, and the serum concentrations of oestradiol and progesterone were examined on day 1, 5, 7 and 13. The mean number of follicles gradually increased with the eCG treatment and decreased after hCG injection. The ovulation rate of follicles was significantly higher in the vaginal stimulation group (70.0%) than in the control group (42.6%). During the hormonal treatments, the serum concentration of oestradiol and progesterone did not differ between the two groups. Ultrasound imaging of the ovaries clamped at a subcutaneous site showed that eCG and hCG treatment promoted the follicular growth and corpus luteum formation, respectively. The combination of hCG injection with vaginal stimulation by a vasectomised tomcat enhanced the ovulation rate of follicles

Cystic Ovarian Follicles in Cattle

The objective of this study was to determine the effects of different intramuscular dosages of human chorionic gonadotropin (hCG) on ovarian follicular development of dairy cows diagnosed with refractory cystic ovarian follicles (COFs). Cows diagnosed with COFs (≥25mm in diameter) were allocated to four treatment groups: hCG-1 (n = 3), a single dose of 4,500 IU on day 1; hCG-2 (n = 3), 2,250 IU on days 1 and 3; hCG-3 (n = 3), 1,500 IU on days 1, 3, and 5; and hCG-C (n = 3) received saline on day 1. Blood sampling and ovarian ultrasonographic (US) examinations were performed on days 1, 3, 5, 7, and 14. A progesterone (P4) value 1 ng/ml was 100% (3/3) and 100% (3/3) in group hCG-1; 100% (3/3) and 67% (2/3) in group hCG-2; 67%(2/3) and 100%(3/3) in group hCG-3; and 33%(1/3) and 33%(1/3) in group hCG-C, respectively. Strong tendencies of P4 increases in group hCG-1 (P = 0.054) and hCG-2 (P = 0.051) were measured after hCG administration. Additionally, P4 values tended to be higher (P = 0.07) for group hCG-1 compared to group hCG-C on day 5. The preliminary findings of this study suggest that multiple smaller doses of hCG might be equally effective as a single large dose of hCG in modulating ovarian follicular development in dairy cows with COFs

Effects of dibutyryl cyclic adenosine monophosphate and human chorionic gonadotropin on the formation of antral follicle-like structures by bovine cumulus—oocyte complexes

This study evaluated the effect of dibutyryl cyclic adenosine monophos-phate (dbcAMP) and human chorionic gonadotropin (hCG) on the formation of antral follicle-like structures (AFLSs) and on the meiotic status of bovine cumulus– oocyte complexes (COCs) embedded in collagen gel. Supplementation with dbcAMP increased the mean diameter of AFLSs during days 4–8 of culture compared with that of control COCs, irrespective of the concentration of dbcAMP used (0.5–2.0 mM). When the embedded COCs were cultured for 8 days with hCG, the diameters of AFLSs after 4 days of culture tended to be lower in the supplemented COCs than in the control COCs without hCG, irrespective of the concentration used (1–100 IU/mL). Supplementation with 10 IU/mL hCG increased the concentrations of anti-Müllerian hormone but not progesterone and oestradiol in the culture medium after 4 days of culture. Almost all oocytes collected from AFLSs had resumed meiosis by the end of culture, irrespective of supplementation of dbcAMP and hCG. These results indicate that although dbcAMP had a positive effect on AFLS formation and development, supplementation with hCG was detrimental. Moreover, hCG supplementation did not influence the luteinisation of granulosa cells in the AFLS for 4 days after the start of culture

Correlation Analysis Between Time Awareness and Morningness-Eveningness Preference

The circadian clock is adjusted by light inputs via the retinohypothalamic tract. Because environmental light is controllable for modern humans at the individual’s preference although under social schedules, individual differences in time-related psychology and behavior may be associated with morningness-eveningness preference (M-E preference). To examine this hypothesis, we used the Time Management Scale and Time Anxiety Scale to quantify time-related psychology and behavior. These scales aim to evaluate “awareness of effective time management and utilization” and “anxiety about uncontrollable time schedule and unexpected time-related outcome”, respectively. According to our correlation analysis using mid-sleep time as a marker for M-E preference, we obtained results supporting our hypothesis in the correlation between the M-E preference values and the Time Management Scale scores, with larger “time estimation” and “taking each moment as it comes” scores associated with more morningness and eveningness, respectively. Considering that modern humans likely become night owls under artificial light conditions, it appears plausible that lower awareness of time management leads to more eveningness

Mislocalization of Visual Stimuli: Independent Effects of Static and Dynamic Attention

Shifts of visual attention cause systematic distortions of the perceived locations of visual objects around the focus of attention. In the attention repulsion effect, the perceived location of a visual target is shifted away from an attention-attracting cue when the cue is presented before the target. Recently it has been found that, if the visual cue is presented after the target, the perceived location of the target shifts toward the location of the following cue. One unanswered question is whether a single mechanism underlies both attentional repulsion and attraction effects. We presented participants with two disks at diagonal locations as visual cues and two vertical lines as targets. Participants were asked to perform a forced-choice task to judge targets' positions. The present study examined whether the magnitude of the repulsion effect and the attraction effect would differ (Experiment 1), whether the two effects would interact (Experiment 2), and whether the location or the dynamic shift of attentional focus would determine the distortions effects (Experiment 3). The results showed that the effect size of the attraction effect was slightly larger than the repulsion effect and the preceding and following cues have independent influences on the perceived positions. The repulsion effect was caused by the location of attnetion and the attraction effect was due to the dynamic shift of attentional focus, suggesting that the underlying mechanisms for the retrospective attraction effect might be different from those for the repulsion effect

当院の子宮下部筋腫合併妊娠における分娩転帰について

　子宮筋腫は年齢と共に有病率が増加する。それ故、近年における晩婚化や出産年齢の高齢化に伴い、子宮筋腫合併妊娠も増加傾向にある。比較的大きな子宮筋腫が子宮下部にある場合、経腟分娩困難と判断され帝王切開が選択される症例も少なくないと考えられる。　子宮筋腫の位置及び大きさと経腟分娩の可否について検討するため、当院の外来にて経腟分娩困難となる可能性があると判断された子宮筋腫合併妊娠で、妊娠後期に核磁気共鳴画像法(Magnetic Resonance Imaging:以下MRI)が撮影された6症例に対して後方視的に検討した。6症例中5症例で経腟分娩が可能であったが、子宮体下部後壁に長径90mmの子宮筋腫を認めた1例は、妊娠41週で予定日超過のため誘発を開始したが、分娩停止のため帝王切開による分娩となった。帝王切開の1例を他の5例と比較すると、年齢、妊娠週数、子宮筋腫の大きさに特記すべき差異を認めないが、子宮筋腫の位置がほぼ正中で、かつ子宮筋腫の下端が内子宮口よりも低位であるとの特徴を認めた。逆に、長径70〜120mmの子宮下部筋腫が存在してもその位置が正中から偏心している場合や、位置が正中でも下端が内子宮口よりも高位であれば、経腟分娩が可能であった