Movement of radioactive isotopes in the phloem tissue was investigated by the stripping technic similar to that used by Stout and Hoagland, i.e., the bark was separated from the wood and a piece of paraffined paper was inserted between them. When P32 was introduced to the leaves, it moved both upward and downward chiefly through the phloem tissue. C14 invariably moved in the phloem when supplied to the leaves in the form of C14O2. The simultaneous movement of these 2 radioactive tracers in opposite directions in the phloem was studied by supplying them separately to the leaves at each end of a stripped area. Their radioactivities were separated by the dry combustion method. Radioactivity due to C14 was re-covered in the BaCO3 fraction, while that due to P32 was re-tained in the ash. By carrying out this expt. under continuous light for a short period of time, considerable amt. of both P32 and C14 were found in the phloem of the stripped area. This is considered to be conclusive evidence for the simultaneous movement of P32 and C14 in opposite directions in the phloem tissue.

The Hill reaction was followed by the reduction of an oxidation-reduction dye, 2, 6-dichlorophenol indophenol. Samples of the mixture of the dye and chloroplasts were exposed to monochromatic light obtained from a Wood replica grating monochro-mator. The degree of dye reduction produced by exposure was measured with a Beckman spectrophotometer at the wave length corresponding to the absorption peak of the dye. The action spectrum of this reaction was obtained by plotting the effectiveness of light against wave length. This curve was compared with the absorption spectrum of chloroplast suspension and the photosynthetic action spectra of Chlorella and Ulva. Quantum requirement for this reaction was calculated. All findings are consistent with the view that Hill reaction is identical with the primary photochemical step of photosynthesis. The action spectrum of this reaction thus may be interpreted as a measure of the spectrum effectiveness for the photosynthetic process in chlorophasts of a higher plant.

Cuttings of garnet peridotite were collected between 603.2 and 683.5 in in the CCSD at Donghai. Minerals were separated by various methods and handpicked under a binocular microscope. The selected minerals were identified by SEM-EDS, microprobe, Laser Raman, and EDXD ( Synchrontron X-ray Diffraction). A number of unusual minerals have been recognized from the cuttings, e. g., moissanite, w stite, native Fe, native Cr, native Ni, native An, native Cu, native Al, taenite, kamacite, Ni-Fe-Cr alloy, Ni-Fe alloy, Fe-Cr alloy, Si-Fe alloy (Fe3Sgamma), and Co-Ni alloy. Two grains of Fe2P alloy (barringerite), have also been found. They are spheroidal in shape, with diameters of about 200 mu m, and they have identical hexagonal structures with cell parameters of a = 5.877 angstrom, c = 3.437 angstrom, and a: c = 1 :0.5848. They belong to space group P62m. This mineral, which is similar in structure and composition to artificial Fe2P (ICDD 83-2337), has previously only been found in meteorites. This is the first reported natural terrestrial occurrence of barringerite. Further study on its genesis and formational conditions is underway.

To evaluate the feasibility and capability of using filter-feeding bivalves as biofilters for organic waste derived from fish faeces and feed wastage in marine fish culture activities, a polyculture system comprising fish and green-lipped mussels Perna viridis was developed by transplantation of mussels into fish cages. As a control, mussels from the same population were simultaneously transplanted to a distant reference site free of effects from fish farming activities. After 3 mo acclimation, samples of mussel tissue, particulate organic matter (POM), fish feed and fish faeces were collected for measurements of carbon and nitrogen isotopic ratios and fatty acid profiles. Enrichment of C-13 and N-15 in mussel tissue collected inside the fish cages as compared to those at the reference site indicated the uptake and assimilation of isotopically heavier fish feed and fish faeces. Compared with mussels from the reference site, the pattern of fatty acid profiles and single fatty acids of mussels in fish cages also tended to be closer to fatty acid profiles of fish feed from fish farms. Based on the concentration-weighted isotope mixing model, the proportions of mussel biomass assimilated from POM, fish feed and fish faeces to mussel dietary consumption were 68.3, 27.5 and 4.2%, respectively. The direct uptake of organic waste from fish farms by filter-feeding mussels is different to their consumption of phytoplanktonic biomass, because the nutrient flux is shifted between these 2 distinct pathways.

E7, a single domain Family 33 cellulose binding module (CBM) protein, and E8, a non-catalytic, three-domain protein consisting of a Family 33 CBM, a FNIII domain, followed by a Family 2 CBM, were cloned, expressed, purified, and characterized. Western blots showed that E7 and E8 were induced and secreted when Thermobifida fusca was grown on cellobiose, Solka floc, switchgrass, or alfalfa as well as on beta-1,3 linked glucose molecules such as laminaribiose or pachyman. E8 bound well to alpha- and beta-chitin and bacterial microcrystalline cellulose (BMCC) at all pHs tested. E7 bound strongly to P-chitin, less well to a-chitin and more weakly to BMCC than E8. Filter paper binding assays showed that E7 was 28% bound, E8 was 39% bound, a purified CBM2 binding domain from Cel6B was 88% bound, and only 5% of the Cel5A catalytic domain was bound. A C-terminal 6 x His tag influenced binding of both E7 and E8 to these substrates. Filter paper activity assays showed enhanced activity of T. fusca cellulases when E7 or E8 was present. This effect was observed at very low concentrations of cellulases or at very long times into the reaction and was mainly independent of the type of cellulase and the number of cellulases in the mixture. E8, and to a lesser extent E7, significantly enhanced the activity of Serratia marscescens Chitinase C on beta-chitin.

We have previously described the creation and analysis of a Notch1 activity-trap mouse line, Notch1 intramembrane proteolysis-Cre6MT or N1IP::Cre(LO), that marked cells experiencing relatively high levels of Notch1 activation. Here, we report and characterize a second line with improved sensitivity (N1IP::Cre(HI)) to mark cells experiencing lower levels of Notch1 activation. This improvement was achieved by increasing transcript stability and by restoring the native carboxy terminus of Cre, resulting in a five- to tenfold increase in Cre activity. The magnitude of this effect probably impacts Cre activity in strains with carboxy-terminal Ert2 fusion. These two trap lines and the related line N1IP::Cre(ERT2) form a complementary mapping tool kit to identify changes in Notch1 activation patterns in vivo as the consequence of genetic or pharmaceutical intervention, and illustrate the variation in Notch1 signal strength from one tissue to the next and across developmental time.

We present a comprehensive overview of a volume-complete sample of white dwarfs located within 40 pc of the Sun, a significant proportion of which were detected in Gaia Data Release 3 (DR3). Our DR3 sample contains 1076 spectroscopically confirmed white dwarfs, with just five candidates within the volume remaining unconfirmed (> 99 per cent spectroscopic completeness). Additionally, 28 white dwarfs were not in our initial selection from Gaia DR3, most of which are in unresolved binaries. We use Gaia DR3 photometry and astrometry to determine a uniform set of white dwarf parameters, including mass, effective temperature, and cooling age. We assess the demographics of the 40 pc sample, specifically magnetic fields, binarity, space density, and mass distributions.

Compression of small molecules can induce solid-state reactions that are difficult or impossible under conventional, solution-phase conditions. Of particular interest is the topochemical-like reaction of arenes to produce polymeric nanomaterials. However, high reaction onset pressures and poor selectivity remain significant challenges. Herein, the incorporation of electron-withdrawing and -donating groups into pi-stacked arenes is proposed as a strategy to reduce reaction barriers to cycloaddition and onset pressures. Nevertheless, competing side-chain reactions between functional groups represent alternative viable pathways. For the case of a diaminobenzene:tetracyanobenzene cocrystal, amidine formation between amine and cyano groups occurs prior to cycloaddition with an onset pressure near 9 GPa, as determined using vibrational spectroscopy, X-ray diffraction, and first-principles calculations. This work demonstrates that reduced-barrier cycloaddition reactions are theoretically possible via strategic functionalization; however, the incorporation of pendant groups may enable alternative reaction pathways. Controlled reactions between pendant groups represent an additional strategy for producing unique polymeric nanomaterials.

Microbial heterotrophs (‘picoheterotrophs’) drive global carbon cycling, but how to quantitatively organize their functional complexity remains unclear. Here, we generate a global -scale, mechanistic understanding of marine picoheterotrophic functional biogeography with a novel model -data synthesis. We build picoheterotrophic diversity into a trait -based marine ecosystem model along two axes: substrate lability and optimization for growth rate (copiotrophy) vs. substrate affinity (oligotrophy). Using genetic sequences along an Alaska -to -Antarctica Pacific Ocean transect, we compile 21 picoheterotrophic guilds and estimate their degree of copiotrophy. Data and model agreement suggests that gradients in predation and substrate lability predominantly set biogeographical patterns, and identifies ‘slow copiotrophs’ subsisting at depth. Results demonstrate the predictability of the marine microbiome and connect ecological dynamics with carbon storage, crucial for projecting changes in a warming ocean.