Characterization of the chicken GCAP gene array and analyses of GCAP1, GCAP2, and GC1 gene expression in normal and rd chicken pineal

Journal ArticlePURPOSE: This study had three objectives: (1) to characterize the structures of the chicken GCAP1 and GCAP2 genes; (2) to determine if GCAP1, GCAP2, and GC1 genes are expressed in chicken pineal gland; (3) if GC1 is expressed in chicken pineal, to determine if the GC1 null mutation carried by the retinal degeneration (rd) chicken is associated with degenerative changes within the pineal glands of these animals. METHODS: GCAP1 and GCAP2 gene structures were determined by analyses of chicken cosmid and cDNA clones. The putative transcription start points for these genes were determined using 5'-RACE. GCAP1, GCAP2 and GC1 transcripts were analyzed using Northern blot and RT-PCR. Routine light microscopy was used to examine pineal morphology. RESULTS: Chicken GCAP1 and GCAP2 genes are arranged in a tail-to-tail array. Each protein is encoded by 4 exons that are interrupted by 3 introns of variable length, the positions of which are identical within each gene. The putative transcription start points for GCAP1 and GCAP2 are 314 and 243 bases upstream of the translation start codons of these genes, respectively. As in retina, GCAP1, GCAP2 and GC1 genes are expressed in the chicken pineal. Although the GC1 null mutation is present in both the retina and pineal of the rd chicken, only the retina appears to undergo degeneration. CONCLUSIONS: The identical arrangement of chicken, human, and mouse GCAP1/2 genes suggests that these genes originated from an ancient gene duplication/inversion event that occurred during evolution prior to vertebrate diversification. The expression of GC1, GCAP1, and GCAP2 in chicken pineal is consistent with the hypothesis that chicken pineal contains a functional phototransduction cascade. The absence of cellular degeneration in the rd pineal gland suggests that GC1 is not critical for pineal cell survival

Design and evaluation of controls for drift, video gain, and color balance in spaceborne facsimile cameras

The facsimile camera is an optical-mechanical scanning device which has become an attractive candidate as an imaging system for planetary landers and rovers. This paper presents electronic techniques which permit the acquisition and reconstruction of high quality images with this device, even under varying lighting conditions. These techniques include a control for low frequency noise and drift, an automatic gain control, a pulse-duration light modulation scheme, and a relative spectral gain control. Taken together, these techniques allow the reconstruction of radiometrically accurate and properly balanced color images from facsimile camera video data. These techniques have been incorporated into a facsimile camera and reproduction system, and experimental results are presented for each technique and for the complete system

MP754: A Literature Review of the Effects of Intensive Forestry on Forest Structure and Plant Community Composition at the Stand and Landscape Levels

The effects of intensive forest management on forest structure and plant community composition are not well documented, particularly with respect to the forests in the Northeast. This review presents a six-part synthesis of the literature. The first section considers the effects of intensive forestry practices within the context of naturally regenerated stands. The second section reviews the changes associated with the planting of conifers in softwood sites, as well as those previously occupied by hardwood and mixed-wood stands. The third examines the impacts of intensive management specifically on bryophytes and lichens. The fourth section discusses changes in dead organic matter components of the stand and the fifth with the impact on tree pests. The final section views the effects of intensive forestry from the landscape-scale perspective and is followed by summary and conclusions. While this paper provides a summary of scientific information, it does not recommend policy or propose how the forest should be managed.https://digitalcommons.library.umaine.edu/aes_miscpubs/1022/thumbnail.jp

Aromatic hydrocarbons as ozone precursors before and after outbreak of the 2008 financial crisis in the Pearl River Delta region, south China

In the second half of 2008 China's highly industrialized Pearl River Delta (PRD) region was hard-hit by the financial crisis (FC). This study reports volatile organic compounds measured in the PRD during November-December in both 2007 before the FC and 2008 after the FC. While total mixing ratios of non-methane hydrocarbons (NMHCs) on average were only about 7% lower from 40.2 ppbv in 2007 to 37.5 ppbv in 2008, their ozone formation potentials (OFPs) dropped about 30%, resulting from about 55% plummet of aromatic hydrocarbons (AHs) against a greater than 20% increase of total alkanes/alkenes. The elevated alkanes and alkenes in 2008 could be explained by greater emissions from vehicle exhausts and LPG combustion due to rapid increase of vehicle numbers and LPG consumption; the drop of AHs could be explained by reduced emissions from industries using AH-containing solvents due to the influence of the FC, as indicated by much lower ratios of toluene to benzene and of xylenes/ trichloroethylene/tetrachloroethylene to carbon monoxide (CO) in 2008. Source apportionment by positive matrix factorization (PMF) also revealed much less contribution of industry solvents to total anthropogenic NMHCs and particularly to toluene and xylenes in 2008 than in 2007. Based on PMF reconstructed source contributions, calculated OFPs by industrial emissions were responsible for 40.8% in 2007 in contrast to 18.4% in 2008. Further investigation into local industry output statistics suggested that the plummet of AHs in 2008 should be attributed to small enterprises, which contributed largely to ambient AHs due to their huge numbers and non-existent emission treatment, but were much more influenced by the FC. © 2012. American Geophysical Union. All Rights Reserved

The importance of particle dispersion in electrical treeing and breakdown in nano-filled epoxy resin

The addition of nano-fillers has been widely proposed as a method to enhance the dielectric properties of high voltage polymeric insulation, though there are mixed reports in the literature. Here the potential of silica nano-particles to extend the time to failure specifically through resistance to electrical tree growth in epoxy resin is determined. The benefit of silane treating the nano-particles before compounding is clearly established with regard to slowing tree growth and subsequent time to failure. The growth of trees in needle-plane samples is measured in the laboratory with loadings of 1, 3 and 5 wt% nano-filler. In all cases the average times to failure are extended, but silane treatment of the nano-particles prior to compounding yields much superior results. The emergence of a pronounced inception time before tree growth is also noted for the higher-filled, silane-treated cases. The average time to failure of silane-treated 5 wt% filled material was 28 times that of the unfilled resin. The improvement in performance between the nanocomposites with untreated and treated fillers is attributed to fewer agglomerations and improved dispersion of the filler in the treated cases. Measurements of Partial Discharge (PD) indicated significant differences in PD patterns during the growth of trees in the treated and untreated cases. This distinction may provide a quality control method for monitoring materials. In particular, long periods in which PDs were not measured were observed in the silane-treated cases. Visual imaging of tree growth in the unfilled material allowed the changing nature of the tree from fine to tree to dark tree to be observed as it grew. Corresponding PD measurements suggest the dark tree is gradually becoming conductive, and that growth of maximum PD measured is dependent on the relative rates of the growth of the tree and its carbonization. X-ray computer tomography identified significant differences in average tree channel diameters (a reduction from 2.8 µm to 2.0 µm for 1 wt% and 3 wt% cases). This implies that in addition to tree length changes, evaporated tree volumes also change and may explain the change in partial discharge characteristics observed

Optical microsphere resonators: optimal coupling to high-Q whispering gallery modes

A general model is presented for coupling of high-$Q$ whispering-gallery modes in optical microsphere resonators with coupler devices possessing discrete and continuous spectrum of propagating modes. By contrast to conventional high-Q optical cavities, in microspheres independence of high intrinsic quality-factor and controllable parameters of coupling via evanescent field offer variety of regimes earlier available in RF devices. The theory is applied to the earlier-reported data on different types of couplers to microsphere resonators and complemented by experimental demonstration of enhanced coupling efficiency (about 80%) and variable loading regimes with Q>10^8 fused silica microspheres.Comment: 14 pages, 4 figure

\u3ci\u3eDrosophila\u3c/i\u3e Model for Potential Plasticizer Induced Hyperactivity

Plasticizing additives such as phthalates, are known to cause disruptions in human nervous systems linked to neurological disorders, thus with the Drosophila activity monitoring (DAM) system test can be conducted to consider whether the flies are exhibiting hyperactivity (Hlisníková et al., 2021). Drosophila is a useful model for exposure of metabolic compounds followed by general and specific assays of their effects. Our experiments propose a link between exposure to phthalates and hyperactivity between humans that can be investigated with flies as a model for testing hyperactivity (Praveena et al., 2020). The link that is proposed is a cross-sectional study that collected urine samples of children and then scored kids based on attention-deficit/hyperactivity disorder (ADHD) (Kim et al., 2009). The DAM system is a method in which flies are individually monitored for activity during the day and night to notice any differences in general activity, locomotion, and circadian rhythms. The general activities of the flies would be examined alongside a baseline of Drosophila activity, alongside flies induced with glucose to measure any differences in hyperactivity. The addition of glucose is to give a baseline of what hyperactive flies will look like in their sleep cycle and movements in the DAM system We hypothesize a significant increase in hyperactivity in phthalate-exposed flies over both high-glucose and normal flies because phthalates are disrupters in the nervous system, thus may cause signs of hyperactivity when administered to the flies