Nanoparticle growth following photochemical α‐ and β‐pinene oxidation at Appledore Island during International Consortium for Research on Transport and Transformation/Chemistry of Halogens at the Isles of Shoals 2004

Nanoparticle events were observed 48 times in particle size distributions at Appledore Island during the International Consortium for Atmospheric Research on Transport and Transformation/Chemistry of Halogens on the Isles of Shoals (ICARTT/CHAiOS) field campaign from 2 July to 12 August of 2004. Eighteen of the nanoparticle events showed particle growth and occurred during mornings when peaks in mixing ratios of α‐ and β‐pinene and ozone made production of condensable products from photochemical oxidation probable. Many pollutants and other potential precursors for aerosol formation were also at elevated mixing ratios during these events, including NO, HNO3, NH3, HCl, propane, and several other volatile organic carbon compounds. There were no consistent changes in particle composition, although both submicron and supermicron particles included high maximum concentrations of methane sulfonate, sulfate, iodide, nitrate, and ammonium during these events. Nanoparticle growth continued over several hours with a nearly linear rate of increase of diameter with time. The observed nanoparticle growth rates varied from 3 to 13 nm h−1. Apparent nanoparticle aerosol mass fractions (yields) were estimated to range from less than 0.0005 to almost 1 using α‐ and β‐pinene as the presumed particle source. These apparent high aerosol mass fractions (yields) at low changes in aerosol mass are up to two orders of magnitude greater than predictions from extrapolated laboratory parameterizations and may provide a more accurate assessment of secondary organic aerosol formation for estimating the growth of nanoparticles in global models

Body Composition, Protein Deposition, and Efficiency of Lysine Utilization of Growing Pigs Fed Crystalline or Protein-Bound Lysine

Two 4-week experiments were conducted to determine body composition and lysine utilization for protein deposition (PD) in barrows and gilts. Thirty-two growing pigs (16 barrows and 16 gilts; average initial body weight of 40.4 lb) were used in each experiment. Pigs were randomly allotted to one of seven dietary treatments. Four pigs (two barrows and two gilts) were killed at the start and the remaining pigs were killed at the end of the experiments to determine body composition. There were two replications per treatment in each experiment for a total of four replications. Dietary treatments consisted of a basal diet (0.55% lysine) and diets containing 0.65, 0.75, and 0.85% lysine that were achieved by adding lysine to the basal diet from either soybean meal (SBM) or L-lysine•HCl (crystalline). Body protein concentration was greater (P \u3c 0.01) in pigs fed the 0.75% crystalline- supplemented diet than in pigs fed SBM at the same concentration. Gilts had greater (P = 0.05) body lysine concentration than barrows. Body PD and lysine deposition increased linearly with dietary lysine concentration (P \u3c 0.01), but were not different between the two sources of lysine (SBM vs crystalline, respectively) at the same concentration. Barrows and gilts had similar PD and lysine deposition. Body fat concentration decreased (P \u3c 0.01) as the dietary lysine concentration increased for both lysine sources; however, fat deposition was not affected by diet. Water deposition increased with dietary lysine concentration (P = 0.05). Body ash content was similar in pigs fed crystalline or SBM-lysine. The results suggest that PD of growing pigs fed lysine from SBM is similar to that of pigs fed crystalline lysine. Pigs fed 0.75% or 0.85% total lysine (0.20% or 0.30% from SBM) had greater (P \u3c 0.05) efficiency of lysine utilization than pigs fed crystalline-supplemented diets at the same concentration. Gilts utilized lysine from SBM more efficiently than barrows (P \u3c 0.05) at the dietary lysine concentration of 0.75 and 0.85%. The results indicate no significant differences in PD of pigs fed supplemented diets from L-lysine•HCl and soybean meal. However, it appears that the efficiency of lysine utilization of gilts fed diets supplemented with SBM-bound lysine is greater than that of barrows. Supplementing low-protein diets with crystalline amino acids at adequate concentrations can offer environmental benefits towards reducing nitrogen excretion without affecting protein deposition

Body Composition, Protein Deposition, and Efficiency of Lysine Utilization of Growing Pigs Fed Crystalline or Protein-Bound Lysine

Two 4-week experiments were conducted to determine body composition and lysine utilization for protein deposition (PD) in barrows and gilts. Thirty-two growing pigs (16 barrows and 16 gilts; average initial body weight of 40.4 lb) were used in each experiment. Pigs were randomly allotted to one of seven dietary treatments. Four pigs (two barrows and two gilts) were killed at the start and the remaining pigs were killed at the end of the experiments to determine body composition. There were two replications per treatment in each experiment for a total of four replications. Dietary treatments consisted of a basal diet (0.55% lysine) and diets containing 0.65, 0.75, and 0.85% lysine that were achieved by adding lysine to the basal diet from either soybean meal (SBM) or L-lysine•HCl (crystalline). Body protein concentration was greater (P \u3c 0.01) in pigs fed the 0.75% crystalline- supplemented diet than in pigs fed SBM at the same concentration. Gilts had greater (P = 0.05) body lysine concentration than barrows. Body PD and lysine deposition increased linearly with dietary lysine concentration (P \u3c 0.01), but were not different between the two sources of lysine (SBM vs crystalline, respectively) at the same concentration. Barrows and gilts had similar PD and lysine deposition. Body fat concentration decreased (P \u3c 0.01) as the dietary lysine concentration increased for both lysine sources; however, fat deposition was not affected by diet. Water deposition increased with dietary lysine concentration (P = 0.05). Body ash content was similar in pigs fed crystalline or SBM-lysine. The results suggest that PD of growing pigs fed lysine from SBM is similar to that of pigs fed crystalline lysine. Pigs fed 0.75% or 0.85% total lysine (0.20% or 0.30% from SBM) had greater (P \u3c 0.05) efficiency of lysine utilization than pigs fed crystalline-supplemented diets at the same concentration. Gilts utilized lysine from SBM more efficiently than barrows (P \u3c 0.05) at the dietary lysine concentration of 0.75 and 0.85%. The results indicate no significant differences in PD of pigs fed supplemented diets from L-lysine•HCl and soybean meal. However, it appears that the efficiency of lysine utilization of gilts fed diets supplemented with SBM-bound lysine is greater than that of barrows. Supplementing low-protein diets with crystalline amino acids at adequate concentrations can offer environmental benefits towards reducing nitrogen excretion without affecting protein deposition

Signature of the Simplicial Supermetric

We investigate the signature of the Lund-Regge metric on spaces of simplicial three-geometries which are important in some formulations of quantum gravity. Tetrahedra can be joined together to make a three-dimensional piecewise linear manifold. A metric on this manifold is specified by assigning a flat metric to the interior of the tetrahedra and values to their squared edge-lengths. The subset of the space of squared edge-lengths obeying triangle and analogous inequalities is simplicial configuration space. We derive the Lund-Regge metric on simplicial configuration space and show how it provides the shortest distance between simplicial three-geometries among all choices of gauge inside the simplices for defining this metric (Regge gauge freedom). We show analytically that there is always at least one physical timelike direction in simplicial configuration space and provide a lower bound on the number of spacelike directions. We show that in the neighborhood of points in this space corresponding to flat metrics there are spacelike directions corresponding to gauge freedom in assigning the edge-lengths. We evaluate the signature numerically for the simplicial configuration spaces based on some simple triangulations of the three-sphere (S^3) and three-torus (T^3). For the surface of a four-simplex triangulation of S^3 we find one timelike direction and all the rest spacelike over all of the simplicial configuration space. For the triangulation of T^3 around flat space we find degeneracies in the simplicial supermetric as well as a few gauge modes corresponding to a positive eigenvalue. Moreover, we have determined that some of the negative eigenvalues are physical, i.e. the corresponding eigenvectors are not generators of diffeomorphisms. We compare our results with the known properties of continuum superspace.Comment: 24 pages, RevTeX, 4 eps Figures. Submitted to Classical Quantum Gravit

Attraction of human monocytes by the neuropeptide secretoneurin

AbstractSecretoneurin is a newly discovered 33-amino-acid peptide derived from secretogranin II (chromogranin C) that is found in sensory afferent C-fibers. We show here that secretoneurin triggers the selective migration of human monocytes in vitro and in vivo. Combinations of secretoneurin with the sensory neuropeptides, substance P or somatostatin, synergistically stimulate such migration. The attraction of monocytes represents the first established function of secretoneurin as a sensory neuropeptide

Hidden biosphere in an oxygen-deficient Atlantic open ocean eddy: future implications of ocean deoxygenation on primary production in the eastern tropical North Atlantic

The eastern tropical North Atlantic (ETNA) is characterized by a highly productive coastal upwelling system and a moderate oxygen minimum zone with lowest open ocean oxygen (O2) concentrations of around 40 μmol kg−1. Only recently, the discovery of re-occurring mesoscale eddies with sometimes close to anoxic O2 concentrations (<1 μmol kg−1) and located just below the mixed layer challenged our understanding of O2 distribution and biogeochemical processes in this area. Here, we present the first metagenomic dataset from a deoxygenated anticyclonic modewater eddy in the open waters of the ETNA. In the eddy, we observed a significantly lower bacterial diversity compared to surrounding waters, along with a significant community shift. We detected enhanced primary productivity in the surface layer of the eddy indicated by elevated chlorophyll concentrations and increased carbon uptake rates up to three times as high as in surrounding waters. Carbon uptake below the euphotic zone correlated to the presence of a specific high-light ecotype of Prochlorococcus, which is usually underrepresented in the ETNA. Our combined data indicate that high primary production in the eddy fuels export production and the presence of a specific microbial community responsible for enhanced respiration at shallow depths, below the mixed layer base. Progressively decreasing O2 concentrations in the eddy were found to promote transcription of the key gene for denitrification, nirS, in the O2-depleted core waters. This process is usually absent from the open ETNA waters. In the light of future ocean deoxygenation our results show exemplarily that even distinct events of anoxia have the potential to alter microbial community structures and with that critically impact primary productivity and biogeochemical processes of oceanic water bodies

The Macroscopic Rate of Nucleic Acid Translocation by Hepatitis C virus Helicase NS3h is Dependent on Both the Sugar and Base Moieties

The NS3 helicase (NS3h) of hepatitis C virus (HCV) is a 3′ to 5′ SF2 RNA and DNA helicase that is essential for the replication of HCV. We have examined the kinetic mechanism of translocation of NS3h along single-stranded nucleic acid with bases rU, dU and dT and have found that the macroscopic rate of translocation is dependent upon both the base and sugar moieties of the nucleic acid, with approximate macroscopic translocation rates of 3 nt/s (oligo-dT), 35 nt/s (oligo-dU), and 42 nt/s (oligo-rU), respectively. We found a strong correlation between the macroscopic translocation rates and the binding affinity of the translocating NS3h protein to the respective substrates such that weaker affinity corresponded to faster translocation. The values of K0.5 for NS3h translocation at a saturating ATP concentration are: (3.3 ± 0.4) μM nucleotide (poly-dT), (27 ± 2) μM nucleotide (poly-dU), and (36 ± 2) μM nucleotide (poly-rU). Furthermore, the results of isothermal titration of NS3h with these oligonucleotides suggest that differences in TΔS° are the principal source of the differences in the affinity of NS3h binding to these substrates. Interestingly, despite the differences in macroscopic translocation rates and binding affinities, the ATP coupling stoichiometry for NS3h translocation was identical for all three substrates, ~0.5 ATP molecules consumed per nucleotide translocated. This similar periodicity of ATP consumption implies a similar mechanism for NS3h translocation along RNA and DNA substrates

&quot;EDML1&quot;: a chronology for the EPICA deep ice core from Dronning Maud Land, Antarctica, over the last 150 000 years.

A chronology called EDML1 has been developed for the EPICA ice core from Dronning Maud Land (EDML). EDML1 is closely interlinked with EDC3, the new chronology for the EPICA ice core from Dome-C (EDC) through a stratigraphic match between EDML and EDC that consists of 322 volcanic match points over the last 128 ka. The EDC3 chronology comprises a glaciological model at EDC, which is constrained and later selectively tuned using primary dating information from EDC as well as from EDML, the latter being transferred using the tight stratigraphic link between the two cores. Finally, EDML1 was built by exporting EDC3 to EDML. For ages younger than 41 ka BP the new synchronized time scale EDML1/EDC3 is based on dated volcanic events and on a match to the Greenlandic ice core chronology GICC05 via &lt;sup&gt;10&lt;/sup&gt;Be and methane. The internal consistency between EDML1 and EDC3 is estimated to be typically ~6 years and always less than 450 years over the last 128 ka (always less than 130 years over the last 60 ka), which reflects an unprecedented synchrony of time scales. EDML1 ends at 150 ka BP (2417 m depth) because the match between EDML and EDC becomes ambiguous further down. This hints at a complex ice flow history for the deepest 350 m of the EDML ice core

A reliable cw Lyman-α\alpha laser source for future cooling of antihydrogen

We demonstrate a reliable continuous-wave (cw) laser source at the 1\,$S$--2\,$P$ transition in (anti)hydrogen at 121.56\,nm (Lyman-$\alpha$) based on four-wave sum-frequency mixing in mercury. A two-photon resonance in the four-wave mixing scheme is essential for a powerful cw Lyman-$\alpha$ source and is well investigated.Comment: 8 pages, 3 figures, Proceedings of LEAP 201