A Drosophila mutant (ninaAP228) that is low in rhodopsin concentration but identical to the wild-type fly in photoreceptor morphology has been isolated. R1-6 photoreceptors of the mutant differ from those of wild type in that (a) the prolonged depolarizing afterpotential (PDA) is absent, (b) concentrations of rhodopsin and opsin are substantially reduced, and (c) intramembrane particle density ...

Drosophila eye development provides an excellent model system to study the role of inter-cellular signaling in the specification of unique cell fates. Behavioral screens by Benzer and his colleagues led to the identification of a gene, Sevenless, a receptor tyrosine kinase (RTK) receptor, required for the specification of the UV sensitive R7 cell. Genetic analysis further showed that the Ras/Ra...

Color vision is based on the differential color sensitivity of retinal photoreceptors, however the developmental programs that control photoreceptor cell differentiation and specify color sensitivity are poorly understood. In Drosophila there is growing evidence that the color sensitivity of the R8 cell within an individual ommatidium is regulated by an inductive signal from the adjacent R7 cel...

in this paper, by using the survival models, survival functions for the time from birth to the event of using formula (i.e. the time that baby in fed by breast milk) in urban and rural areas of takestan (iran, winter 1998) are reported. later the relation between the mentioned time and some factors are also discussed. the kaplan-meire method and cox regression are used in this paper as well. 48...

mycotoxins are secondary metabolites of molds and have adverse effects on humans, animals, and crops. those can cause illnesses and economic losses. aflatoxin m1 (afm1) is one of the mycotoxins produced from the hydroxylated metabolite of aflatoxin b1 (afb1). it can be found in milk or milk products obtained from livestock that have ingested contaminated feed. in this paper, recent studies were...

BACKGROUND Copper is an essential mineral involved in the formation and stabilisation of extracellular skin proteins. As copper can be absorbed through intact skin, we reasoned that using socks containing copper-impregnated fibres may have an effect on skin elasticity. METHODS A double blind, placebo controlled study was conducted in which one group of healthy volunteers (n = 32) wore socks w...

We cloned the chicken Hoxb-4 gene and performed in situ analysis to investigate conservation in patterns of expression between the chicken and mouse. The anterior boundaries of expression for both genes in segmented tissues, such as the hindbrain and paraxial mesoderm, map to the same rhombomere (r) (r6/r7) and somite (s) (s6/s7) limits, showing a direct correlation between expression of a spec...