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We identified a novel, 6,513-bp-long RNA, termed Bombyx mori macula-like latent virus (BmMLV) RNA, which abundantly expressed in B. mori cultured BmN cells. BmMLV RNA potentially encodes two proteins, putative RNA replicase and coat protein, which share structural features and sequence similarities with those of a plant RNA virus, the genus Maculavirus. Northern blot analysis showed that two transcripts were expressed in BmN cells: a 6.5-kb-long RNA, which contains both putative RNA replicase and coat protein genes, and a 1.2-kb-long RNA, which contains only a coat protein gene. Southern blot analysis showed that BmMLV RNA is not carried by the B. mori genome. RT-PCR analysis also revealed the presence of BmMLV RNA in several B. mori cell lines other than BmN cells, suggesting that BmMLV RNA latently exists in B. mori cultured cells. Infection studies showed that BmMLV virions were able to infect BmMLV-negative Spodoptera frugiperda Sf-9 cells and B. mori larvae. Electron microscopy and Northern blot analysis of a purified BmMLV revealed that isometric virions appear to be 28 to 30 nm in diameter and contain a 6.5-kb genomic RNA. These results showed that BmMLV is a novel macula-like virus infectious to and replicable in B. mori-derived cells.

In surveys of three groups of workers occupationally exposed to polychlorinated biphenyls (PCBs) serum PCB concentrations were quantitated as lower chlorinated biphenyls (L-PCBs) and higher chlorinated biphenyls (H-PCBs). Serum L-PCB and H-PCB concentrations were many times greater among workers employed in power capacitor manufacturing than among the general population, even comparing employees never assigned to work in PCBexposed areas. Statistically significant positive correlations of symptoms suggestive of mucous membrane and skin irritation, of systemic malaise, and altered peripheral sensation were noted with increasing concentrations of serum PCB. No clinical abnormalities attributable to exposure to PCB were observed. Serum PCB concentrations were positively and significantly correlated with glutamic-oxalacetic transaminase (SGOT), serum gamma-glutamyl transpeptidase (GGTP), and plasma triglyceride, and inversely correlated with plasma high density lipoproteincholesterol. These correlations were present across all study sites. These findings are indicative of PCBs' physiological effect on the liver, whose long-range health significance is unknown. Nevertheless, the consistent positive association of serum PCB w'th plasma triglyceride and negative association with plasma HDL-cholesterol may have long-wrm cardiovascular consequences.Polychlonnated biphenyls (PCBs), a class of chlorinated aromatic hydrocarbon compounds, have become widely dispersed in the environment.

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;To elucidate the mechanism of plant responses to shading, we identified three promoter/enhancer trap lines (M812, J53, J59) that exhibited reporter expression in the hypocotyl in response to the end-of-day far-red light treatment. Interestingly, we found auxin-responsive genes in the vicinities of the reporter insertion sites in M812 and J53. We examined the effects of auxin on the reporter expression in these lines together with a previously identified N35 line. The results indicated that the reporter expression was induced by exogenous auxin in N35 and J53. Furthermore, an auxin transport inhibitor inhibited the responses of these lines to the end-of-day far-red light treatment, suggesting the involvement of auxin in the responses of plants to shading. By contrast, neither auxin nor the transport inhibitor affected the response in M812 and J59. Interestingly, J59 responded to ABA. Hence, ABA might be involved in the response as well. Analysis of the photoreceptive sites for the responses revealed the cotyledons, not the hypocotyl, are the major photoreceptive sites both in the auxin-responsive and ABA-responsive lines. Hence, some signals appeared to be transmitted from the cotyledons to the hypocotyl.

Two-photon photoemission (2PPE) spectroscopy is used to reveal dynamic relaxation of highly excited electrons generated by 3 eV photons in Si. Monochromatic 2PPE at probe-photon energies ranging from 3.2 to 3.5 eV reveals a coherent 2PPE peak from the valence band maximum, and a transiently populated photoemission peak near L 1 in the conduction band. Time-resolved 2PPE measurements show that electrons injected into the L valley undergo L-to-X intervalley scattering with a time constant of 180 fs at 293 K. A deformation potential constant of 1.2 eVÅ −1 is obtained for the scattering. The highly excited electrons are relaxed down around the conduction band minimum to form a quasi-equilibrated hot electron distribution; the highest density is accumulated at 660 fs after excitation. The hot electron distribution is equilibrated with the lattice within 2 ps after excitation. These results are compared to relaxation processes of electrons injected directly into the X valley by photons with energies below 2.2 eV.

A pool of Arabidopsis lines transformed with the activation vector was screened for short hypocotyl mutants under dim far-red light, and three mutant lines designated chibi1-3 (chi) were isolated. Among the chi mutants, chi2 was dominant. The chi2 seedlings were short, regardless of the light conditions. The chi2 mature plants exhibited phenotypic features such as dwarfism, reduced male fertility and dark green, rounded epinastic leaves, which are characteristics of brassinosteroid-deficient mutants such as det2, cpd, and dwf4. Furthermore, the hypocotyl phenotype was restored by the addition of brassinolide to the culture medium, suggesting that brassinosteroids had been affected in this mutant. The molecular analysis of the chi2 mutant revealed that the CYP72C1 gene was overexpressed by the enhancing activity of the inserted DNA. Wild-type plants that were transformed with a vector containing a chimeric gene between the 35S promoter and the CYP72C1 genomic DNA exhibited a similar phenotype. Consistent with the morphological and physiological phenotype, the levels of active brassinosteroids were reduced in the chi2 mutant. Hence, CYP72C1, together with BAS1/CYP72B1, is speculated to regulate active brassinosteroid levels in plants. Expression analysis suggested that wild-type CYP72C1 transcript levels increased after exposure to white light, although the physiological significance of such a response remains obscure.