Virus-like particles associated with marine mussel mortalities in New Zealand

Green-lip mussel Pema canaliculus spat (15 to 30 mm length) in the outer Marlborough Sounds, New Zealand, suffered 50 to 100% mortality during January to April 1994 (summer/autumn) following thinning and reseeding of the mussel lines by farmers. Adult mussel mortalities of 2 to 5 % continued from February to early May 1994. Histological examination showed extensive haemocytosis and multifocal liquefaction necrosis of interstitial cells, basal cells and digestive tubule epithelial cells. Sloughed pyknotic or karyolytic digestive tubule epithelial cells formed characteristic rounded granular bodies 10 to 15 μm diameter both in digestive tubules and free in lesions . No viral inclusion bodies were observed. Ultrastructural examination showed highly modified rough endoplasmic reticulum associated with small, 25 to 45 nm diameter, electron- dense uncoated virus-like particles Identical cell damage and virus-like particles were subsequently found in monbund adult (75 to 110 mm length) P canaliculus and stunted (25 to 4 7 mm length) subt1dal Mvtilus galloprovincialis from the same area. Following purfication of extracts of the moribund spat by isopycnic centrifugation in CsCJ, large numbers of 25 nm diameter, unenveloped, virus particles were seen by electron microscopy. These particles had a density of 1.364 g cm- 3 A broad band at a density expected for enveloped particles (1.21to1.24 g cm 1 ) was also observed but contained few virus-like particles. Cell damage and mussel mortalities are thus likely due to a small unenveloped virus

Fathers\u27 and Mothers\u27 Cognitive Stimulation in Early Play with Toddlers: Predictors of 5th grade Reading and Math

Developmental support in early parent-infant interactions has been shown to predict children\u27s early development and later academic success, but the long-term combined impacts of maternal and paternal interactions are rarely examined. For 229 low-income children in the US Early Head Start Research and Evaluation Project, parent-toddler interactions at age 2, observed separately with fathers and mothers, were examined in relation to child outcomes at age 3 and 5th grade. In families with resident biological fathers, both mother and father cognitive stimulation independently predicted 5th grade math and reading, over and above program impacts and child gender. In other families, only mother cognitive stimulation predicted later child outcomes, even if fathers were involved in children\u27s lives. Adding early developmental indicators to the model showed that the contributions of mothers\u27 early cognitive stimulation on children\u27s later academic skills were significantly mediated by children\u27s early development in biological father-resident families, but not in other families. Similarly, adding early developmental indicators to the reading model showed that the contributions of fathers\u27 early cognitive stimulation on children\u27s later reading was partially mediated by children\u27s early vocabulary in biological father-resident families, but not in other families. These results suggest that fathers\u27 and mothers\u27 cognitive stimulation in early play with toddlers both have the potential to make long-term direct and indirect impacts on their children\u27s academic success