Synthesis of [3-C-13]-2,3-dihydroxy-4-methoxybenzaldehyde

An efficient synthesis of [3-13C]-2,3-dihydroxy-4-methoxybenzaldehyde, an isotopically labelled probe of a common intermediate used in the synthesis of a number of biologically relevant molecules, has been achieved in 9 steps from an acyclic, non-aromatic precursor. A 13C label for molecular imaging was introduced in a linear synthesis from the reaction of [13C]-labelled methyl iodide with glutaric monomethyl ester chloride. Cyclisation then aromatisation gave 1,3-dimethoxybenzene and an additional methoxy group was introduced by a formylation/Baeyer–Villiger/hydrolysis/methylation sequence. Subsequent ortho-formylation and selective demethylation yielded the desired [3-13C]-2,3-dihydroxy-4-methoxybenzaldehyde

Physical Mechanisms of Tropical Climate Feedbacks Investigated Using Temperature and Moisture Trends

ArticleOpen access articleTropical climate feedback mechanisms are assessed using satellite-observed and model-simulated trends in tropical tropospheric temperature from the MSU/AMSU instruments and upper-tropospheric humidity from the HIRS instruments. Despite discrepancies in the rates of tropospheric warming between observations and models, both are consistent with constant relative humidity over the period 1979--2008. Because uncertainties in satellite-observed tropical-mean trends preclude a constraint on tropical-mean trends in models we also explore regional features of the feedbacks. The regional pattern of the lapse rate feedback is primarily determined by the regional pattern of surface temperature changes, as tropical atmospheric warming is relatively horizontally uniform. The regional pattern of the water vapor feedback is influenced by the regional pattern of precipitation changes, with variations of 1--2 W m-2 K-1 across the Tropics (compared to a tropical-mean feedback magnitude of 3.3--4 W m-2 K-1). Thus the geographical patterns of water vapor and lapse rate feedbacks are not correlated, but when the feedbacks are calculated in precipitation percentiles rather than in geographical space they are anti-correlated, with strong positive water vapor feedback associated with strong negative lapse rate feedback. The regional structure of the feedbacks is not related to the strength of the tropical-mean feedback in a subset of the climate models from the CMIP5 archive. Nevertheless the approach constitutes a useful process-based test of climate models and has the potential to be extended to constrain regional climate projections.Natural Environment Research Council (NERC

Target Fragmentation in Semi-Inclusive DIS: Fracture Functions, Cut Vertices and the OPE

We discuss semi-inclusive Deep Inelastic Scattering (DIS) in the z -> 1 limit, in particular the relationship between fracture functions, generalised cut vertices and Green functions of the composite operators arising in the OPE. The implications, in the spin-polarised case, for testing whether the "proton spin" effect is target-independent are explored. Explicit calculations in (phi^3)_6 theory are presented which are consistent with our observations.Comment: 22 pages, 25 figures, LaTeX 2e; uses graphics packag

Differential Equations for Definition and Evaluation of Feynman Integrals

It is shown that every Feynman integral can be interpreted as Green function of some linear differential operator with constant coefficients. This definition is equivalent to usual one but needs no regularization and application of $R$-operation. It is argued that presented formalism is convenient for practical calculations of Feynman integrals.Comment: pages, LaTEX, MSU-PHYS-HEP-Lu2/9

Effect of different standing poses on whole body volume acquisition by three-dimensional photonic scanning

The present study compared whole body volumes obtained by three-dimensional (3D) photonic scanning of two different poses and discussed its effect on body composition estimation. Pose A with large angles of shoulder abduction and feet separated and Pose B with shoulders abducted slightly, the elbows extended and heels together. 16 male and 13 female participants were scanned twice in each pose using a 3D scanner. The mean of whole body volume and the mean of body composition obtained with Pose B was corrected by a regression equation and compared with the results obtained from Pose A. After correction, the whole body volumes acquired with these two poses were similar [limit of agreement = (-0.71 l,0.71 l)] but the body compositions obtained with Pose A and Pose B were different [limit of agreement = (-4.4%, 4.4%)]. The results indicated that scanning using either pose gives reliable estimations for whole body volume and body composition. The whole body volume obtained from different poses can be adjusted using the regression equation but small volumetric differences translate into much more substantial differences in body fat percentage. Hence, it is recommended to use the same scanning pose consistently when monitoring individuals longitudinally

Actors and networks or agents and structures: towards a realist view of information systems

Actor-network theory (ANT) has achieved a measure of popularity in the analysis of information systems. This paper looks at ANT from the perspective of the social realism of Margaret Archer. It argues that the main issue with ANT from a realist perspective is its adoption of a `flat' ontology, particularly with regard to human beings. It explores the value of incorporating concepts from ANT into a social realist approach, but argues that the latter offers a more productive way of approaching information systems

Renormalization of composite operators

The blocked composite operators are defined in the one-component Euclidean scalar field theory, and shown to generate a linear transformation of the operators, the operator mixing. This transformation allows us to introduce the parallel transport of the operators along the RG trajectory. The connection on this one-dimensional manifold governs the scale evolution of the operator mixing. It is shown that the solution of the eigenvalue problem of the connection gives the various scaling regimes and the relevant operators there. The relation to perturbative renormalization is also discussed in the framework of the $\phi^3$ theory in dimension $d=6$.Comment: 24 pages, revtex (accepted by Phys. Rev. D), changes in introduction and summar

Total photoproduction cross-section at very high energy

In this paper we apply to photoproduction total cross-section a model we have proposed for purely hadronic processes and which is based on QCD mini-jets and soft gluon re-summation. We compare the predictions of our model with the HERA data as well as with other models. For cosmic rays, our model predicts substantially higher cross-sections at TeV energies than models based on factorization but lower than models based on mini-jets alone, without soft gluons. We discuss the origin of this difference.Comment: 13 pages, 9 figures. Accepted for publication in EPJC. Changes concern added references, clarifications of the Soft Gluon Resummation method used in the paper, and other changes requested by the Journal referee which do not change the results of the original versio

A 14-year experience with kidney transplantation.

Between November, 1962 and August, 1975, 668 kidney transplants were done in 556 consecutive patients at Denver, Colorado. The Denver experience has been divided into 7 periods of time, according to the conditions of care during each period. The results in related transplantation have changed little during the decade beginning in 1966. The results in unrelated transplantation have not materially changed since 1968. The long-term patient survival after related transplantation has been better than after cadaver transplantation. The results of transplantation in 57 children ages 3 to 18 years have been slightly better than the results of adult transplantation. The outcome of kidney transplantation and the feasibility of improving this therapy with present techniques are limited by our inability to accurately match each patient with the immunologically best donor and by our inability to precisely control the immune system of the recipient. Rejection is still the main reason for graft loss, and sepsis remains the main cause of patient mortality. More specific and less toxic means of achieving graft acceptance are needed before a higher level of patient service can be realized. However, even with the tools now available, thousands of recipients throughout the world have been returned to useful lives