Persistence and potential causes of reduced net CH4 consumption under elevated CO2 in a temperate forest

Impacts of the projected increase in atmospheric CO2 on other biogeochemical cycles are uncertain. In a two-year study, Phillips et al. (2001) reported a 16 to 30% decrease in net consumption of atmospheric CH4 by soils in CO2-enriched plots in a temperate loblolly pine (Pinus taeda) forest. Consumption by upland soils accounts for [approximately]30 Tg CH4 y-1 and is the only terrestrial sink for atmospheric CH4, which is a greenhouse gas with radiative forcing second only to CO2. However, it is uncertain whether decreased atmospheric CH4 consumption represents a transient or sustained response of forest-soil systems to elevated CO2. This research focused on field observations aimed at investigating the strength and persistence of reduced atmospheric CH4 consumption by temperate forest soils under elevated CO2 at the same study site. It further investigates the causes of this response by CH4 oxidizing and producing communities through field and laboratory experiments. Rates of soil-atmosphere CH4 exchange were repeatedly measured over 3 y from permanently established sampling sites at the Free Air Carbon Dioxide (FACE) site in the Duke Forest, where CO2-enriched plots of a loblolly pine forest are maintained at approximately 200 mL L-1 above ambient concentrations (380 mL L-1), while control plots are exposed to ambient atmospheres. Reduced net atmospheric CH4 consumption persisted in CO2-enriched plots, showing annual declines of 19, 10 and 8% relative to control plots. This study and previous work give a nearly continuous 8 y record of reduced net atmospheric CH4 consumption in CO2 -enriched plots that suggests this is likely a sustained negative feedback to increasing atmospheric CO2. Causitive factors for the observed decrease in net CH4 consumption under elevated CO2 were difficult to identify because of high spatial and temporal variability in microbial activity and limited ability to collect soil samples. However, higher soil moisture and increased incidence and rates of CH4 production in CO2-enriched plots, along with transient inhibition by plant exudates and low overall soil diffusivity, begin to explain reduced rates of CH4 consumption and increased rates of CH4 production that result in long-term reduction in net CH4 consumption in these soils

A multivariate approach to human mate preferences

Human mate choice is complicated, with various individual differences and contextual factors influencing preferences for numerous traits. However, focused studies on human mate choice often do not capture this multivariate complexity. Here, we consider multiple factors simultaneously to demonstrate the advantages of a multivariate approach to human mate preferences. Participants (N = 689) rated the attractiveness of opposite-sex online dating profiles that were independently manipulated on facial attractiveness, perceived facial masculinity/femininity, and intelligence. Participants were also randomly instructed to either consider short- or long-term relationships. Using fitness surfaces analyses, we assess the linear and nonlinear effects and interactions of the profiles' facial attractiveness, perceived facial masculinity/femininity, and perceived intelligence on participants' attractiveness ratings. Using hierarchical linear modeling, we were also able to consider the independent contribution of participants' individual differences on their revealed preferences for the manipulated traits. These individual differences included participants' age, socioeconomic status, education, disgust (moral, sexual, and pathogen), sociosexual orientation, personality variables, masculinity, and mate value. Together, our results illuminate various previously undetectable phenomena, including nonlinear preference functions and interactions with individual differences. More broadly, the study illustrates the value of considering both individual variation and population-level measures when addressing questions of sexual selection, and demonstrates the utility of multivariate approaches to complement focused studies

Weak radiative hyperon decays, Hara's theorem and the diquark

Weak radiative hyperon decays are discussed in the diquark-level approach. It is pointed out that in the general diquark formalism one may reproduce the experimentally suggested pattern of asymmetries, while maintaining Hara's theorem in the SU(3) limit. At present, however, no detailed quark-based model of parity-violating diquark-photon coupling exists that would have the necessary properties.Comment: 10 pages, LaTe

STUDY CORRELATING NIOBIUM SURFACE ROUGHNESS WITH SURFACE PARTICLE COUNTS

Abstract A study has been initiated at Michigan State University (MSU) to relate the surface preparation of Superconducting Radio Frequency (SRF) resonators and surface particle counts, using niobium samples. During fabrication, undesired surface roughness can develop on the internal surfaces of the resonators. The final cavity finish will be product of material forming, machining, welding, chemistry, high-pressure rinsing, and handling of the niobium material. This study will document niobium samples treated with MSU standard processing procedures; first measuring the surface roughness, then polishing samples with defined techniques, processing, and measuring surface particle counts. The samples will include as received niobium, machined surfaces, welded surfaces, and surfaces with characterized surface imperfections (scratches)

Hyperon weak radiative decays in chiral perturbation theory

We investigate the leading-order amplitudes for weak radiative decays of hyperons in chiral perturbation theory. We consistently include contributions from the next-to-leading order weak-interaction Lagrangian. It is shown that due to these terms Hara's theorem is violated. The data for the decays of charged hyperons can be easily accounted for. However, at this order in the chiral expansion, the four amplitudes for the decays of neutral hyperons satisfy relations which are in disagreement with the data. The asymmetry parameters for all the decays can not be accounted for without higher-order terms. We shortly comment on the effect of the 27-plet part of the weak interaction.Comment: 8 pages of REVTeX and using macro-package "feynman.tex" (available at http://xxx.lanl.gov/ftp/hep-ph/papers/macros) for the 2 figure

Genotype and Phenotype in 12 additional individuals with SATB2-Associated Syndrome

SATB2-associated syndrome (SAS) is a multisystemic disorder caused by alterations of the SATB2 gene. We describe the phenotype and genotype of 12 individuals with 10 unique (de novo in 11 of 11 tested) pathogenic variants (1 splice site, 5 frameshift, 3 nonsense, and 2 missense) in SATB2 and review all cases reported in the published literature caused by point alterations thus far. In the cohort here described, developmental delay (DD) with severe speech compromise, facial dysmorphism, and dental anomalies were present in all cases. We also present the third case of tibial bowing in an individual who, just as in the previous 2 individuals in the literature, also had a truncating pathogenic variant of SATB2. We explore early genotype-phenotype correlations and reaffirm the main clinical features of this recognizable syndrome: universal DD with severe speech impediment, mild facial dysmorphism, and high frequency of craniofacial anomalies, behavioral issues, and brain neuroradiographic changes. As the recently proposed surveillance guidelines for individuals with SAS are adopted by providers, further delineation of the frequency and impact of other phenotypic traits will become available. Similarly, as new cases of SAS are identified, further exploration of genotype-phenotype correlations will be possible

Progress in development of the readout chip for the ATLAS semiconductor tracker

The development of the ABCD chip for the binary readout of silicon strip detectors in the ATLAS Semiconductor Tracker has entered a pre-production prototyping phase. Following evaluation of the ABCD2T prototype chip, necessary correction in the design have been implemented and the ABCD3T version has been manufactured in the DMILL process. Design issues addressed in the ABCD3T chip and performance of this pre-production prototype are discussed

Measurement of the diffractive structure function in deep inelastic scattering at HERA

This paper presents an analysis of the inclusive properties of diffractive deep inelastic scattering events produced in $ep$ interactions at HERA. The events are characterised by a rapidity gap between the outgoing proton system and the remaining hadronic system. Inclusive distributions are presented and compared with Monte Carlo models for diffractive processes. The data are consistent with models where the pomeron structure function has a hard and a soft contribution. The diffractive structure function is measured as a function of \xpom, the momentum fraction lost by the proton, of $\beta$, the momentum fraction of the struck quark with respect to \xpom, and of $Q^2$. The \xpom dependence is consistent with the form \xpoma where $a~=~1.30~\pm~0.08~(stat)~^{+~0.08}_{-~0.14}~(sys)$ in all bins of $\beta$ and $Q^2$. In the measured $Q^2$ range, the diffractive structure function approximately scales with $Q^2$ at fixed $\beta$. In an Ingelman-Schlein type model, where commonly used pomeron flux factor normalisations are assumed, it is found that the quarks within the pomeron do not saturate the momentum sum rule.Comment: 36 pages, latex, 11 figures appended as uuencoded fil

A Search for Light Super Symmetric Baryons

We have searched for the production and decay of light super-symmetric baryons produced in 800 GeV/c proton copper interactions in a charged hyperon beam experiment. We observe no evidence for the decays R+(uud \g^~) -> S(uds \g^~) pi+ and X-(ssd \g^~) -> S(uds \g^~) pi- in the predicted parent mass and lifetime ranges of 1700-2500 Mev/c2 and 50-500 ps. Production upper limits for R+ at xF=0.47, Pt=1.4 GeV/c2 and X- at xF=0.48, Pt=0.65 GeV/c2 of less than 10^-3 of all charged secondary particles produced are obtained for all but the highest masses and shortest lifetimes predicted.Comment: 9 pages, uuencoded postscript 4 figures uuencoded, tar-compressed file (submitted to PRL

THE IMPACT OF GEL ELECTROPHORESIS UPON OUR UNDERSTANDING OF THE ESTERASES *

The impact of gel electrophoresis upon our understanding of the esterases has been formidable in that it has provided us with new insights and understanding concerning the number and biochemical characteristics of the many esterase-active proteins found in biological material. The relationships between the esterases within a species and among species still remains largely to be determined. With regard to the function of esterases it is to be expected that there will be several. One promising possibility is suggested by the work of Allen and Hunter, which illustrated a dependent relationship between male sex hormone and the esterases in the mouse epididymis. Supporting this work is the observation by Shaw and Koen (1963) demonstrating the presence of an esterase in the mouse kidney, which also was dependent on male sex hormone. The change observed in the serum esterase of the pregnant rabbit reported here and in women by Friedman and Lapman (1961) may also relate to hormone changes associated with pregnancy, although this relationship remains to be demonstrated. A second area where the esterases are likely to be functioning is in relation to protein synthetic activity of the endoplasmic reticulum. The only evidence supporting this suggestion is the abundant presence of esterases found in this location. The seven experiments described and discussed here along with those included in the references may serve as illustrations of the kind of work that can be accomplished by the use of these methods.*Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75632/1/j.1749-6632.1964.tb14224.x.pd