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Janet Y. Uriu‐Adams Sarah G. Obican Carl L. Keen 《Birth defects research. Part C, Embryo today : reviews》2013,99(1):24-44
The essentiality of vitamin D for normal growth and development has been recognized for over 80 years, and vitamin D fortification programs have been in place in the United States for more than 70 years. Despite the above, vitamin D deficiency continues to be a common finding in certain population groups. Vitamin D deficiency has been suggested as a potential risk factor for the development of preeclampsia, and vitamin D deficiency during infancy and early childhood is associated with an increased risk for numerous skeletal disorders, as well as immunological and vascular abnormalities. Vitamin D deficiency can occur through multiple mechanisms including the consumption of diets low in this vitamin and inadequate exposure to environmental ultraviolet B rays. The potential value of vitamin D supplementation in high‐risk pregnancies and during infancy and early childhood is discussed. Currently, there is vigorous debate concerning what constitutes appropriate vitamin D intakes during early development as exemplified by differing recommendations from the Institute of Medicine Dietary Reference Intake report and recent recommendations by the Endocrine Society. As is discussed, a major issue that needs to be resolved is what key biological endpoint should be used when making vitamin D recommendations for the pregnant woman and her offspring. Birth Defects Research (Part C) 99:24–44, 2013. © 2013 Wiley Periodicals, Inc. 相似文献
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In the wild, primate foraging behaviors are related to the diversity and nutritional properties of food, which are affected by seasonal variation. The goal of environmental enrichment is to stimulate captive animals to exhibit similar foraging behavior of their wild counterparts, e.g. To extend foraging time. We conducted a 12-month study on the foraging behavior of Japanese macaques in a semi-naturally forested enclosure to understand how they use both provisioned foods and naturally available plant foods and what are the nutritional criteria of their consumption of natural plants. We recorded time spent feeding on provisioned and natural plant foods and collected the plant parts ingested of their major plant food species monthly, when available.We conducted nutritional analysis (crude protein, crude lipid, neutral detergent fiber-'NDF', ash) and calculated total non-slructural carbohydrate - 'TNC' and total energy of those food items. Monkeys spent 47% of their feeding time foraging on natural plant species. The consumption of plant parts varied significantly across seasons. We found that leaf items were consumed in months when crude protein, crude protein-to-NDF ratio, TNC and total energy were significantly higher and NDF was significantly lower, fruit/nut items in months when crude protein and TNC were significantly higher and crude lipid content was significantly lower, and bark items in months when TNC and total energy were higher and crude lipid content was lower. This preliminary investigation showed that the forested enclosure allowed troop members to more fully express their species typical flexible behavior by challenging them to adjust their foraging behavior to seasonal changes of plant item diversity and nutritional content, also providing the possibility for individuals to nutritionally enhance their diet. 相似文献
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Water striders are insects living on the water surface, over which they can move very quickly and rarely get wetted. We measured the force of free walking in water striders, using a hair attached to their backs and a 3D strain gauge. The error was calculated by comparing force and data derived from geometry and was estimated as 13%. Females on average were stronger (1.32 mN) than males (0.87 mN), however, the ratio of force to weight was not significantly different. Compared with other lighter species, Aquarius paludum seems stronger, but the ratio of force to weight is actually lower. A. paludum applies about 0.3 mN·cm-1 to 0.4 mN·cm-1 with its mid-legs, thus avoiding penetrating the surface tension layer while propelling itself rapidly over the water surface.We also investigated the external morphology with SEM. The body is covered by effectively two layers of macro-and micro-hairs, which renders them hydrophobic. The setae are long (40 um-60 um) and stiff, being responsible for waterproofing, and the microtrichia are much smaller (<10 um), slender, and flexible, holding a bubble over the body when submerged. 相似文献
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Miki T Kiyonaka S Uriu Y De Waard M Wakamori M Beedle AM Campbell KP Mori Y 《Channels (Austin, Tex.)》2007,1(3):144-147
Genetic analyses have revealed an association between the gene encoding the Rab3A-interacting molecule (RIM1) and the autosomal dominant cone-rod dystrophy CORD7. However, the pathogenesis of CORD7 remains unclear. We recently revealed that RIM1 regulates voltage-dependent Ca(2+) channel (VDCC) currents and anchors neurotransmitter-containing vesicles to VDCCs, thereby controlling neurotransmitter release. We demonstrate here that the mouse RIM1 arginine-to-histidine substitution (R655H), which corresponds to the human CORD7 mutation, modifies RIM1 function in regulating VDCC currents elicited by the P/Q-type Ca(v)2.1 and L-type Ca(v)1.4 channels. Thus, our data can raise an interesting possibility that CORD7 phenotypes including retinal deficits and enhanced cognition are at least partly due to altered regulation of presynaptic VDCC currents. 相似文献
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In vertebrate somitogenesis, “segmentation clock” genes (her in zebrafish, hes in mouse, and hairy in chick) show oscillation, synchronized over nearby cells through intercellular interaction. In zebrafish, neighboring cells
interact by Delta-Notch signaling to realize synchronization. Under Delta-Notch, however, a cell with a high expression of
the segmentation clock gene tends to suppress its expression in adjacent cells, which might produce spatial heterogeneity
instead of synchronized oscillation. Here we studied the conditions under which pre-somitic mesoderm cells show synchronized
oscillation of gene expression mathematically. We adopted a model that explicitly considers the kinetics of the mRNA and proteins
of the segmentation clock gene and cell–cell interaction via Delta-Notch signaling. From statistical study of a model with
randomly generated parameters, we revealed how the likelihood that the system generates stable synchronized oscillation depends
on the rate of each reaction in the gene–protein kinetics. 相似文献