Effects of β‐carotene‐enriched dry carrots on β‐carotene status and colostral immunoglobulin in β‐carotene‐deficient Japanese Black cows

Data from 18 β‐carotene‐deficient Japanese Black cows were collected to clarify the effects of feeding β‐carotene‐enriched dry carrots on β‐carotene status and colostral immunoglobulin (Ig) in cows. Cows were assigned to control or carrot groups from 3 weeks before the expected calving date to parturition, and supplemental β‐carotene from dry carrots was 138 mg/day in the carrot group. Plasma β‐carotene concentrations in the control and carrot groups at parturition were 95 and 120 μg/dL, and feeding dry carrots slightly improved plasma β‐carotene at parturition. Feeding dry carrots increased colostral IgA concentrations in cows and tended to increase colostral IgG₁, but colostral IgM, IgG₂, β‐carotene and vitamin A were not affected by the treatment. Feeding dry carrots had no effects on plasma IgG₁, IgA and IgM concentrations in cows, but plasma IgG₁ concentrations decreased rapidly from 3 weeks before the expected calving date to parturition. These results indicate that feeding β‐carotene‐enriched dry carrots is effective to enhance colostral IgA and IgG₁ concentrations in β‐carotene‐deficient cows.     

Exposure to blue LED light before the onset of darkness under a long‐day photoperiod alters melatonin secretion,feeding behaviour and growth in female dairy calves

The effect of blue LED on melatonin secretion, feeding behaviour and growth was addressed in Holstein female dairy calves. In Exp.1, six animals (8 weeks old, 97 ± 4.1 kg BW) were exposed to yellow or blue LED for 2 hr before darkness over 7 days under a long‐day photoperiod (LDPP). In Exp. 2, six animals (8 weeks old, 88.5 ± 4.8 kg BW) were exposed to blue light from a white LED all daytime or a yellow LED for 2 hr before the darkness of LDPP (blue light cut) over 3 weeks. In Exp. 1, blue light mildly suppressed melatonin secretion during the 2‐hr treatment but did not affect the timing of the nightly melatonin rise. However, the rise in nighty melatonin levels was higher with yellow than blue LED. In Exp. 2, white LED completely suppressed melatonin secretion during the 2‐hr treatment, but plasma melatonin concentrations were similar during the darkness. Grass hay intake, rumination time, frequency of water intake and body weight gain were higher in animals exposed to the yellow rather than the white LED. Overall results indicate that exposure to blue light from white LEDs under an LDPP suppresses melatonin secretion and might negatively impact the development of female dairy calves.     

Evidence for estrogen receptor expression during medullary bone formation and resorption in estrogen-treated male Japanese quails (Coturnix coturnix japonica)

The temporal expression of estrogen receptor (ER)-α and ER-β mRNA was examined in male Japanese quails. Femurs of quails receiving 17β-estradiol underwent RTPCR and histochemical analysis 1 to 15 days after treatment. Untreated quails were used as controls (day 0). Between days 0 and 5, cells lining the bone endosteal surface differentiated into osteoblasts, which in turn formed medullary bone. Expression of ER-α was already observed on day 0 and increased slightly during bone formation whereas ER-β was hardly detected throughout this process. After osteoclasts appeared on the medullary bone surface, this type of bone disappeared from the bone marrow cavity (days 7~15). ER-α expression simultaneously decreased slightly and ER-β levels remained very low. These results suggest that estrogen activity mediated by ER-α not only affects medullary bone formation but also bone resorption.     

Unstable side population phenotype of mouse spermatogonial stem cells in vitro

Stem cells of the side population (SP) phenotype are found in many self-renewing tissues and can be identified by their unique ability to effectively exclude the dye Hoechst 33342. We previously established a method for expanding spermatogonial stem cells (SSCs) in vitro, but the frequency of SSCs is only about 1 to 2%, limiting detailed SSC analyses. In this study, we sought to isolate SSCs from in vitro cultures by exploiting their ability to exclude Hoechst 33342. In contrast to the findings of previous in vivo studies, we found that SP cells developed in a stochastic manner in vitro. Moreover, SP cells in culture were not enriched in SSCs, but they were interconvertible with non-SP cells. Although SP cells were consistently found in testes after transplantation of cultured cells, they were not enriched in SSCs. These results show that SSCs have an unstable SP phenotype and provide evidence that SSCs change their phenotype characteristics in response to their microenvironment.     

Mass and local topography measurements of Itokawa by Hayabusa

The ranging instrument aboard the Hayabusa spacecraft measured the surface topography of asteroid 25143 Itokawa and its mass. A typical rough area is similar in roughness to debris located on the interior wall of a large crater on asteroid 433 Eros, which suggests a surface structure on Itokawa similar to crater ejecta on Eros. The mass of Itokawa was estimated as (3.58 +/- 0.18) x 10(10) kilograms, implying a bulk density of (1.95 +/- 0.14) grams per cubic centimeter for a volume of (1.84 +/- 0.09) x 10(7) cubic meters and a bulk porosity of approximately 40%, which is similar to that of angular sands, when assuming an LL (low iron chondritic) meteorite composition. Combined with surface observations, these data indicate that Itokawa is the first subkilometer-sized small asteroid showing a rubble-pile body rather than a solid monolithic asteroid.     

Effects of glutathione treatments during sperm washing and in vitro fertilization on the in vitro early development of embryos of Japanese Black cattle

This study was conducted to examine the effects of adding glutathione (1 mM) to media used for sperm washing and in vitro fertilization (IVF) on the improvement of early development of embryos produced using cryopreserved spermatozoa of the less IVF-competent bull (the one considered unqualified as spermatozoa supplier for the production of bovine blastocysts using IVF). The cryopreserved spermatozoa of this bull were characterized by normal motility and lower ATP content and blastocyst productivity than those of IVF-competent bulls. The addition of glutathione to the sperm washing medium was more effective in improving the productivity of blastocysts and ATP content than the addition of glutathione to the IVF medium or no glutathione addition at all (control). These results suggest that this simple method may be used to improve the potential of cryopreserved spermatozoa of less IVF-competent bulls to fertilize oocytes in vitro and to induce normal embryonic development after fertilization.     

Value-per-recruit analysis of bighand thornyhead <Emphasis Type="Italic">Sebastolobus macrochir</Emphasis> caught off the Pacific coast of northern Honshu,Japan

The yield-per-recruit (YPR) analysis has been used to assess growth overfishing of exploited fish stocks. Since the ex-vessel price per weight widely depends on the size of the fish, the result of the YPR does not imply the revenue. The value-per-recruit (VPR) analysis, which is an economic expansion of the YPR analysis, was conducted for bighand thornyhead Sebastolobus macrochir caught off the Pacific coast of northern Honshu, Japan. The results showed that, for the current age at first capture (t _c = 3), the current fishing mortality (F = 0.12) was close to the optimum level. However, for the current F, optimum t _c in the VPR model was 8 years and would lead to a 47% increase compared to the current revenue. The maximum YPR was obtained at t _c = 6 years, but the revenue at t _c = 6 only gave a 20% increase in the maximum revenue. The difference was caused by the size dependency of the ex-vessel price per weight. The VPR model would generate fisheries management plans with both economical and biological consideration and would help in making general consensus of fisheries management strategies.     

Spatial–temporal variations in the composition of two <Emphasis Type="Italic">Zostera</Emphasis> species in a seagrass bed: implications for population management of a commercially exploited grass shrimp

We examined spatial and temporal variations in the species composition of two seagrass species, Zostera marina and Z. caespitosa, in a lagoon facing the Sea of Okhotsk. We also considered how those variations affected habitat quality for motile epifauna, especially for a commercial shrimp. A long-interval comparison between 1996 and 2013 showed that seagrass species composition in the lagoon did not vary, while their relative abundances did. A survey in 2012 revealed that the abundance of Z. caespitosa was affected by the abundance of Z. marina, water depth, and location in the lagoon. Although these seagrass species have similar aboveground morphology, differences in their fine structures were detected. Diversities of motile animals inhabiting the seagrass species were the same. Differences in seagrass utilization were observed when we focused on a commercial shrimp, Pandalus latirostris. This shrimp always preferred higher densities of shoots irrespective of the species and seasonally changed their preference for the number of leaves per shoot. They were therefore more abundant in Z. caespitosa, which had those structural characteristics. The results suggest that the management of shrimp resources could be improved by flexibly changing protected areas in accordance with the dynamics of seagrass distribution in the lagoon.