According to the pigment theory of matching, metameric matches result from the equation of the rates of photoisomerizations for each of the three classes of cone pigments excited by the two matched fields. If true, matches are radiance-invariant and additive. Tests of the theory in this paper show small but ubiquitous failures in radiance-invariance due to systematic rather than random errors i...

Variation in plant shoot structure may be described as occurring through changes within a basic unit, the metamer. Using this terminology, the apical meristem of Arabidopsis produces three metameric types sequentially: type 1, rosette; type 2, coflorescence-bearing with bract; and type 3, flower-bearing without bract. We describe a mutant of Arabidopsis, Leafy, homozygous for a recessive allele...

Segmented organisms have serially repeated structures [1] that become specialized in some segments [2]. We show here that the Drosophila corpora allata, prothoracic glands, and trachea have a homologous origin and can convert into each other. The tracheal epithelial tubes develop from ten trunk placodes [3, 4], and homologous ectodermal cells in the maxilla and labium form the corpora allata an...

Variation in plant shoot structure may be described as occurring through changes within a basic unit, the metamer. Using this terminology, the apical meristem of Arabidopsis produces three metameric types sequentially: type 1, rosette; type 2, coflorescence-bearing with bract; and type 3, flower-bearing without bract. We describe a mutant of Arabidopsis, Leafy, homozygous for a recessive allele...

A heart is described pathologically in which the aorta emerged from the right ventricle and was not related to the ventricular septal defect, while the pulmonary trunk emerged from both ventricles, but mostly the right, and was related to the ventricular septal defect. This Taussig-Bing arrangement of vessels was coupled with the presence of the aortic orifice to the left and the pulmonic orifi...

A 2-year-old boy was born at term of healthy, non-consanguineous Iranian parents. His mother attended in the clinic with the history of sometimes discoloration of diapers after passing urine. She noticed that first at the age of one month with intensified in recent months. His Physical examination and growth parameters were normal. His mother denied taking any medication (sorbitol, nitrofuranto...

background black pepper (piper nigrum) is one of the well-known spices extensively used worldwide especially in india, and southeast asia. the presence of alkaloids in the pepper, namely, piperine and its three stereoisomers, isopiperine, chavicine and isochavicine are well noticed. objectives the current study evaluated the effect of lyophilization and oven drying on the stability and decompos...

the main objective of this study was to determine the effects of nitrogen fixing bacteria and manure application on the seed yield and yield components in black cumin (nigella sativa l.). the experiment was carried out at the ran research station in firouzkouh in 2012. a 4×4 factorial experiment, arranged in a randomized complete blocks designed with three replications. the treatments consisted...

a 2-year-old boy was born at term of healthy, non-consanguineous iranian parents. his mother attended in the clinic with the history of sometimes discoloration of diapers after passing urine. she noticed that first at the age of one month with intensified in recent months. his physical examination and growth parameters were normal. his mother denied taking any medication (sorbitol, nitrofuranto...