Yolk provides an important source of nutrients during the early development of oviparous organisms. It is composed mainly of vitellogenin proteins packed into membrane-bound compartments called yolk platelets. Catabolism of yolk is initiated by acidification of the yolk platelet, leading to the activation of Cathepsin-like proteinases, but it is unknown how this process is triggered. Yolk catab...

A description of the fine structure of the yolk of the unincubated hen's egg has been provided, which will serve as a basis for further studies on yolk digestion. The gross components of the yolk (that is, free-floating lipid drops, yellow and white yolk spheres together with their enclosed lipid subdroplets, and aqueous protein fluid) could be recognized by phase contrast and low power electro...

In S. bullata, the ovaries contribute to the synthesis of yolk polypeptides. A specific antiserum for yolk polypeptides was used to visualize the presence of yolk polypeptides in the follicle cells during their differentiation. After vitellogenesis has started, all follicle cells contain yolk polypeptides. The squamous follicle cells covering the nurse cells and the border cells lose yolk polyp...

Little is known about how metabolism changes during development. For most animal embryos, yolk protein is a principal source of nutrition, particularly of essential amino acids. Within eggs, yolk is stored inside large organelles called yolk platelets (YPs). We have gained insight into embryonic nutrition in the African clawed frog Xenopus laevis by studying YPs. Amphibians follow the ancestral...

Let Z1, ..., Zn be i.i.d observations, where Zi = Xi +Yi and Xi and Yi are independent random variables. Assume that the distribution of Y ’s is known. The ordinary deconvolution problem is the problem of estimating the destribution of a random variables Xi from the observations Zi. In some situations (for instance, in signal processing) we don’t know the distribution of Yi but rather can assum...

PURPOSE To describe the ethnic differences in central corneal thickness (CCT) in population-based samples of ethnic Bai, Yi and Han people living in rural China. METHODS 6504 adults (2119 ethnic Bai, 2202 ethnic Yi and 2183 ethnic Han) aged 50 years or older participated in the study. Each subject underwent standardized ocular examinations and interviewer-administered questionnaires for risk ...

Summary. Objectives: To evaluate the clinical accuracy of antiphospholipid antibody (aPL) specificities both individually and/or in combination, in a wide cohort of systemic lupus erythematosus (SLE) patients in an attempt to identify a panel of tests that may provide the best accuracy for diagnosing antiphospholipid syndrome (APS). Patients and Methods:This study included 230 patients (218 wom...

We report on basic natural history, life history, and diet of Priapella chamulae (Poeciliidae) from Arroyo Tres, a small creek in Tabasco, southern México. The tertiary (adult) sex ratio was heavily female-skewed, female P. chamulae produced medium-sized offspring (~2.3 mg), one clutch at a time (i.e., showed no superfetation), and relied predominantly on yolk for embryo provisioning (Matrotrop...