Transmission of white sturgeon iridovirus in Kootenai River white sturgeon Acipenser transmontanus

It is thought that white sturgeon iridovirus (WSIV) is transmitted vertically from adult white sturgeon Acipenser transmontanus to progeny, and that wild adults are carriers of this virus. Based on this assumption, egg disinfection trials were initiated using wild Kootenai River white sturgeon. Over 2 consecutive years, post-fertilized eggs were disinfected with iodine at concentrations ranging from 0 to 400 ppm. Eggs were incubated and progeny were reared on either de-chlorinated municipal or Kootenai River water. Juvenile sturgeon (mean weight 3.0 g) from these treatment groups were then subjected to a density stress (15 or 20 g(-1)) to manifest WSIV disease in individuals harboring the virus. In Year 1, mortality in all groups ranged from 6 to 37% and the use of municipal water was shown to significantly improve survival. However, WSIV infection was not detected in fish from any of the treatment groups or controls, and therefore did not contribute to the observed mortality. In Year 2, all treatment and control groups reared on Kootenai River water tested positive for WSIV infection and exhibited mortality ranging from 59 to 94%, but fish from groups reared on municipal water did not test positive for WSIV infection. This shows that that vertical transmission did not occur in this study. Horizontal transmission played a significant role in WSIV infection, but the lack of infection in Year 1 suggests a cyclic occurrence of the virus in the Kootenai River system. Although survival tended to be better in iodine-treated groups, the effects of iodine treatment in relation to WSIV transmission remain unknown. An important finding is that not all wild white sturgeon broodstock yield WSIV-positive progeny.     

Differential riboflavin deposition in white and variegated white mutants of Drosophila hydei

Riboflavin deposition in organs of Drosophila hydei was studied by means of a growth test using a riboflavin-deficient strain of the fungus Aspergillus nidulans. In wild-type animals, riboflavin is deposited in Malpighian tubules (MT) and testes but not in adult eyes. Certain white (w) mutants do not contain riboflavin, whereas intermediately colored w mutants contain minor amounts of the substance. Riboflavin-containing MT cells contain special globules that can be fixed and stained with the redox dye phenazine-methosulphate. The number and size of these granules is related to growth effect and point to a role of the w locus in the intracellular deposition of riboflavin in special organs. In white-mottled (wm) position-effect variegation mutants, a significant correlation was found between the extent of variegation (percentage of yellow cells) and riboflavin content (growth effect) of the MT. However, the individual variation of cell phenotype was extremely large and exaggerated types were observed indicating "overdominance" of the rearranged w+ gene. This contradicts an unsubstantiated dogma of position-effect variegation that assumes that the affected gene simply switches between the on and off state, as is discussed.     

Egg white proteins.

1. Egg white proteins are the principal solutes present in egg white, making up approximately 10% of its weight. 2. They are globular proteins and most have acidic isoelectric points. 3. Many are glycoproteins with carbohydrate contents ranging from 2 to 58%. 4. Of the major egg white proteins, lysozyme is the only one having catalytic activity, but many have specific binding sites, e.g. for vitamins such as biotin, riboflavin and thiamin, or for metal ions such as FeIII. 5. A major group are those showing proteinase inhibitory activity, and they include ovomucoid, ovoinhibitor, cystatin and ovostatin. 6. The synthesis of egg white protein occurs in the oviduct, and is hormonally controlled either by oestrogens or progesterone. 7. Extensive studies have been carried out in the genes coding for egg white proteins.     

Preparation of balanced trichromatic white phosphors for solid‐state white lighting

High quality white light‐emitting diodes (LEDs) employ multi‐component phosphor mixtures to generate light of a high color rendering index (CRI). The number of distinct components in a typical phosphor mix usually ranges from two to four. Here we describe a systematic experimental technique for starting with phosphors of known chromatic properties and arriving at their respective proportions for creating a blended phosphor to produce light of the desired chromaticity. This method is applicable to both LED pumped and laser diode (LD) pumped white light sources. In this approach, the radiometric power in the down‐converted luminescence of each phosphor is determined and that information is used to estimate the CIE chromaticity coordinate of light generated from the mixed phosphor. A suitable method for mixing multi‐component phosphors is also described. This paper also examines the effect of light scattering particles in phosphors and their use for altering the spectral characteristics of LD‐ and LED‐generated light. This is the only approach available for making high efficiency phosphor‐converted single‐color LEDs that emit light of wide spectral width.     

Tests for resistance to white clover mosaic virus in red and white clover

A range of red and white clover cultivars was tested for immunity to white clover mosaic virus. All plants became infected although some showed no symptoms. Enzyme-linked immunosorbent assay (ELISA) and immunosorbent electron microscopy (ISEM) revealed significant differences in virus concentration between red clover cultivars and between clones of white clover artificially infected with the virus. These differences could not, however, be related to relative yield losses.     

Unconfined compression of white matter

The porous properties of brain tissue are important for understanding normal and abnormal cerebrospinal fluid flow in the brain. In this study, a poroviscoelastic model was fitted to the stress relaxation response of white matter in unconfined compression performed under a range of low strain rates. A set of experiments was also performed on the tissue samples using a no-slip boundary condition. Results from these experiments demonstrated that the rheological response of the white matter is primarily governed by the intrinsic viscoelastic properties of the solid phase. The permeability of white matter was found to be of the order of 10(-12) m4/Ns.