Precise Orbit Determination for ALOS

The Advanced Land Observing Satellite (ALOS) has been developed to contribute to the fields of mapping, precise regional land coverage observation, disaster monitoring, and resource surveying. Because the mounted sensors need high geometrical accuracy, precise orbit determination for ALOS is essential for satisfying the mission objectives. So ALOS mounts a GPS receiver and a Laser Reflector (LR) for Satellite Laser Ranging (SLR). This paper deals with the precise orbit determination experiments for ALOS using Global and High Accuracy Trajectory determination System (GUTS) and the evaluation of the orbit determination accuracy by SLR data. The results show that, even though the GPS receiver loses lock of GPS signals more frequently than expected, GPS-based orbit is consistent with SLR-based orbit. And considering the 1 sigma error, orbit determination accuracy of a few decimeters (peak-to-peak) was achieved

Metataxonomic Analysis of the Uterine Microbiota Associated with Low Fertility in Dairy Cows Using Endometrial Tissues Prior to First Artificial Insemination

The deterioration in reproductive performance in association with low fertility leads to significant economic losses on dairy farms. The uterine microbiota has begun to attract attention as a possible cause of unexplained low fertility. We analyzed the uterine microbiota associated with fertility by 16S rRNA gene amplicon sequencing in dairy cows. First, the alpha (Chao1 and Shannon) and beta (unweighted and weighted UniFrac) diversities of 69 cows at four dairy farms that had passed the voluntary waiting period before the first artificial insemination (AI) were analyzed with respect to factors including farm, housing style, feeding management, parity, and AI frequency to conception. Significant differences were observed in the farm, housing style, and feeding management, except parity and AI frequency to conception. The other diversity metrics did not show significant differences in the tested factors. Similar results were obtained for the predicted functional profile. Next, the microbial diversity analysis of 31 cows at a single farm using weighted UniFrac distance matrices revealed a correlation with AI frequency to conception but not with parity. In correlation with AI frequency to conception, the predicted function profile appeared to be slightly modified and a single bacterial taxon, Arcobacter, was detected. The bacterial associations related to fertility were estimated. Considering these, the uterine microbiota in dairy cows can be varied depending on the farm management practices and may become one of the measures for low fertility

The role for insulin-like growth factor-I in preimplantation embryonic development and decidualization following superovulation in the rat

Superovulation causes detrimental effects, including embryonic loss and implantation failure. This study determined potential roles for insulin-like growth factor (IGF-I) in uterine environment regulation and preimplantation development, in conjunction with the detrimental effects of superovulation in the rat. IGF-I may be beneficial to preimplantation embryonic development. IGF-I stimulated embryonic development and metabolism in vitro and increased the rate of implantation and fetal development when the blastocysts were transferred into a receptive uterus. However, IGF-I may be involved in embryonic loss following superovulation, by perturbing the uterine environment. Superovulation enhanced uterine IGF-I action from day 1 to 3 of pregnancy and reduced its action on days 5 and 6. Uterine luminal fluid from the uterus exposed to increased IGF-I action from day 1 to 3 was detrimental to embryonic development. This uterine luminal fluid had altered electrolyte composition that is similar to that observed following superovulation. Anti-IGF-I antibody restored superovulationinduced alterations in cations, suggesting that IGF-I may partially mediate this effect of superovulation. Superovulation-induced alterations in IGF-I action may adversely affect decidualization, a critical step in implantation. High IGF-I levels from day 1 to 3 and low levels from day 3 to 5, inhibited deciduoma formation. Alterations in IGF-I action after day 5 had no effect, suggesting a role for IGF-I in uterine sensitization. The role of IGF-I in decidualization may be complex. IGF-I cannot be substituted for growth hormone (GH) and thyroxine (T4) during decidualization, but altered deciduoma formation and alkaline phosphatase (ALP) activity in the GH and T4-dependent manner. IGF-I either stimulated or inhibited deciduoma formation and ALP activity, depending upon concentration and treatment period. IGF-I stimulated basal ALP activity but inhibited prostaglandin E2-stimulated ALP activity in the endometrial stroma cells. In conclusion, IGF-I may play an important role in the maintenance of a receptive uterine environment for embryonic development and the regulation of decidualization. Embryonic loss and failure of implantation following superovulation may be partially attributed to disturbances in uterine IGF-I action as observed in this study.Medicine, Faculty ofObstetrics and Gynaecology, Department ofGraduat

ATP content and maturational/developmental ability of bovine oocytes with various cytoplasmic morphologies

We examined the relationship among morphological appearance (six groups) of bovine oocytes, ATP content and maturational/developmental ability. Oocytes with a brown ooplasm (with or without a dark region) had intermediate levels of ATP at the germinal vesicle (GV) stage and showed higher rates of first polar body (PB) extrusion than the other groups. Oocytes with a low level of ATP (oocytes with a pale ooplasm without dark clusters) and oocytes with a high level of ATP (oocytes with a black ooplasm) showed lower rates of PB extrusion. During in vitro maturation, ATP levels in oocytes decreased at around GV breakdown and increased toward metaphase II (MII). MII oocytes having a brown ooplasm with a dark region, which had good developmental capacity, had a relatively high level of ATP. MII oocytes with a brown or pale ooplasm without dark clusters, which had poor developmental capacity, had low ATP levels. MII oocytes with a black ooplasm, which had poor developmental capacity, had an unusually high level of ATP. These results suggest that the morphological appearance of bovine oocytes is closely related to their ATP levels and that cytoplasmic morphology will give an advantage for the selection of oocytes with a high maturational and developmental ability

Endometrial epidermal growth factor profile and its abnormalities in dairy cows

Normal cows have 2 peaks in endometrial epidermal growth factor (EGF) concentrations on Days 2-4 and 13-14, and the absence of peaks has been linked to reduced fertility in repeat breeder (RB) cows. However, the timing of the peaks (i.e., day of examinations) was estimated for a few cows per cycle day. Therefore, the present study characterized EGF peaks and examined if the absence of peaks in RB cows indicate either peak loss or changed timing. In Study 1, 20 Holstein cows were examined for EGF concentrations between Days 1 and 6 using repeated biopsy of the uterine endometrial tissues. Sixteen cows exhibited increased EGF concentrations for 2-3 days between Days 2 and 5. All 16 cows exhibited increased EGF concentrations on Day 3. In Study 2, 10 cows were examined for EGF concentrations between Days 11 and 16. Increased EGF concentrations for 2-3 days were found in 7 cows between Days 12 and 15. All 7 cows exhibited increased EGF concentrations on Days 13 and 14. In Study 3, 12 RB cows were examined for endometrial EGF concentrations between Days 1 and 6. Four cows exhibited an increase of EGF concentrations on Days 3 and 4, whereas 8 cows (66.7%) exhibited low EGF concentrations throughout the study period. In conclusion, Days 3 and 13-14 are suitable days to examine a cyclic change of endometrial EGF concentrations. Further, low EGF concentrations on Day 3 in RB cows indicated an absence, but not altered timing, of the EGF peak

Fertilizability of oocytes derived from Holstein cows having different antral follicle counts in ovaries

In this study, to clarify the relationship between ovarian reserve and oocyte quality, cumulus-oocyte complexes (COCs) were collected repeatedly by ovum pick-up (OPU) from cows with high and low antral follicle counts (AFCs) at short (3–4 days) and long (7 days) intervals, and COC morphologies and oocyte fertilizability were examined. The relationship between AFC and follicular growth after OPU was also investigated. Cows showing AFC of ≥30 in at least one OPU session were grouped into the high-AFC group. At a short interval, follicular sizes and COC morphologies were similar between the different AFC groups. However, the normal fertilization rate was higher in the high-AFC group than in the low one, although total penetration rates were similar. At a long interval, the percentage of COCs with poor morphology in the high-AFC group was higher and the normal fertilization rate was lower than in the low one. In the low-AFC group, normal fertilization rates at short and long intervals were similar, and mean follicular size became larger at a long than at a short interval. However, mean follicular sizes at short- and long-interval OPU were similar in the high-AFC group. In conclusion, it is suggested that oocytes derived from cows with high AFC had higher fertilizability than those from cows with low AFC when OPUs were performed at a short (3–4 days) interval. However, oocyte quality in high-AFC cows was impaired by long-interval (7 days) OPU, possibly due to the degradation of follicles