Size of Sri Lankan newborns at birth.

This prospective population-based study, involving 4,120 births at the Maternity Unit, Teaching Hospital Kandy, in the years 2008 and 2009, was undertaken to determine the mean birth weight of the newborns in the Central Province, Sri Lanka. The mean birth weight of 2,854 g was found to be equivalent with those calculated from several earlier studies. The mean differences in the birth weights of the three major ethnic communities, the Sinhala, the Tamils and the Sri Lankan Moors, were found to be not statistically significant. The gender difference of 60 g (CI 28-92) and the difference between the birth weights of the first and second born, for babies of all three communities were statistically significant, in uniform with those for white Caucasian populations. A graphical production of the mean birth weights is depicted in percentiles, with the mean birth weights of newborns in the UK superimposed on it for comparison.

Vein Loading in Seedlings of Phaseolus vulgaris Exposed to Excess Cobalt, Nickel, and Zinc.

Vein loading in unifoliate leaves of white bean seedlings exposed to excess Co(2+), Ni(2+), or Zn(2+) for 1 to 4 days was studied by incubating leaf discs in [(14)C]sucrose. The discs from plants exposed to metal exhibited an increased total uptake of radiosucrose but reduced vein loading. Differences between treatments due to infiltration of disc margins were eliminated by analyzing 7-millimeter discs cut from the center of incubated 14-millimeter discs. Uptake of radiosucrose was greater particularly in discs from seedlings exposed to excess Ni(2+) and Zn(2+). The effect increased as exposure of the seedlings to metal increased up to 4 days. Autoradiographs showed vein loading in control leaf tissues with most of the radiosucrose accumulating in minor veins and little remaining in the mesophyll. In discs from metal-treated plants, most of the sucrose remained in the mesophyll without accumulating preferentially in the minor veins. This effect was evident within 24 hours of exposure to excess metal and intensified with longer exposures to metal. The inhibition of vein loading was also evident in situ. Both the preferential accumulation of sucrose into the minor veins of control tissues and the accumulation into mesophyll of metal exposed tissues were sensitive to 2,4-dinitrophenol and the blockage of sulfhydryl groups. It is concluded that the inhibition of vein loading contributes markedly to the observed toxicological effects of reduced photoassimilate export and of accumulation of carbohydrates in fully expanded leaves of bean seedlings exposed to excess metal ions.

Carbohydrate Levels and Photoassimilate Export from Leaves of Phaseolus vulgaris Exposed to Excess Cobalt, Nickel, and Zinc.

Exposure of white bean seedlings to phytotoxic burdens of Co, Ni, or Zn reduced the export of (14)C-photoassimilates from the nearly fully expanded unifoliate leaves. Little (14)C reached the major sink areas, the young trifoliate leaves and the root tips, of seedlings exposed to metal. The unifoliate leaves accumulated sucrose, reducing sugars, and starch. These effects were evident within 1 or 2 days.