Jatropha Assessment. Agronomy, socio-economic issues, and ecology. Facts from literature.

Jatropha (Jatropha curcas L.) has been promoted as a potential renewable energy source for many of its advantageous properties in comparison to other biomass feedstock. This report summarises the agronomy, socio-economic issues, and ecology facts from literature on Jatropha. Such an overview is essential to formulate recommendations and policy guidelines to stimulate best project practices and also help to avoid the promotion of unviable or unsustainable practices

The QED Structure of the Photon

Measurements of the QED structure of the photon based on the reaction ee --> ee \gamma(*)(P^2)\gamma*(Q^2) --> ee mumu are discussed. This review is an update of the discussion of the results on the QED structure of the photon presented in Refs.[1], and covers the published measurements of the photon structure functions F_2, F_A nd F_B and of the differential cross-section dsig/dx for the exchange of two virtual photons.Comment: Invited talk given at the 7th International Workshop on Deep Inelastic Scattering and QCD, April 19 to 23, 1999, Zeuthen, to appear in the proceedings. 8pages 4 figure

Phase-slip flux qubits

In thin superconducting wires, phase-slip by thermal activation near the critical temperature is a well-known effect. It has recently become clear that phase-slip by quantum tunnelling through the energy barrier can also have a significant rate at low temperatures. In this paper it is suggested that quantum phase-slip can be used to realize a superconducting quantum bit without Josephson junctions. A loop containing a nanofabricated very thin wire is biased with an externally applied magnetic flux of half a flux quantum, resulting in two states with opposite circulating current and equal energy. Quantum phase-slip should provide coherent coupling between these two macroscopic states. Numbers are given for a wire of amorphous niobium-silicon that can be fabricated with advanced electron beam lithography.Comment: Submitted to New Journal of Physics, special issue solid state quantum informatio

Lipolytic sensitivity to catecholamines in patients with human immunodeficiency virus infection

Lipolysis is higher in patients with acquired immunodeficiency syndrome (AIDS) than in healthy control subjects. To evaluate whether this increase in lipolysis is related to increased beta-adrenergic sensitivity, we compared the lipolytic response to epinephrine (approximately 15 ng x kg(-1) x min(-1)) of six AIDS patients with that of six matched control subjects. Lipolysis was measured by infusion of [2H2]glycerol and [2H2]palmitate. The baseline rates of appearance of palmitate (2.06 +/- 0.21 compared with 1.45 +/- 0.07 micromol x kg(-1) x min(-1)) and glycerol (2.35 +/- 0.16 compared with 1.35 +/- 0.06 micromol x kg(-1) x min(-1)) were higher in AIDS patients (P <0.05). The absolute increase in lipolysis, an indicator of the responsiveness to epinephrine, was not different between groups for the rate of appearance of palmitate (86 +/- 14 compared with 75 +/- 7 micromol x L(-1) x min(-1)) or glycerol (79 +/- 13 compared with 59 +/- 6 micromol x L(-1) x min(-1)). Plasma concentrations of epinephrine were not different between groups. Lipolysis was higher whereas the lipolytic response to epinephrine was normal in AIDS patients. Increased lipolytic sensitivity to catecholamines is not the cause of increased lipolysis in AID

How to assess the external validity of therapeutic trials: a conceptual approach

Background External validity of study results is an important issue from a clinical point of view. From a methodological point of view, however, the concept of external validity is more complex than it seems to be at first glance. Methods Methodological review to address the concept of external validity. Results External validity refers to the question whether results are generalizable to persons other than the population in the original study. The only formal way to establish the external validity would be to repeat the study for that specific target population. We propose a three-way approach for assessing the external validity for specified target populations. (i) The study population might not be representative for the eligibility criteria that were intended. It should be addressed whether the study population differs from the intended source population with respect to characteristics that influence outcome. (ii) The target population will, by definition, differ from the study population with respect to geographical, temporal and ethnical conditions. Pondering external validity means asking the question whether these differences may influence study results. (iii) It should be assessed whether the study's conclusions can be generalized to target populations that do not meet all the eligibility criteria. Conclusion Judging the external validity of study results cannot be done by applying given eligibility criteria to a single target population. Rather, it is a complex reflection in which prior knowledge, statistical considerations, biological plausibility and eligibility criteria all have plac

Absence of a Transcellular Oxalate Transport Mechanism in LLC-PK1 and MDCK Cells Cultured on Porous Supports

Transepithelial oxalate transport across polarized monolayers of LLC-PK1 cells, grown on collagen-coated microporous membranes in Transwell culture chambers, was studied in double-label experiments using [14C]-oxalate together with [3H]-D-mannitol as an extracellular marker. The [14C]-labeled glucose analog α-methyl-glucoside (α-MG) was used as functional marker for active proximal tubular sugar transport. Cellular uptake of oxalate and α-MG at both the apical and basolateral plasma membrane was determined. When added to the upper compartment, α-MG was actively taken up at the apical membrane, directed through the cells to the basolateral membrane and transported to the lower compartment, indicating functional epithelial sugar transport by LLC-PK1 cells. In LLC-PK1 cells, the uptake of α-MG at the apical membrane was approximately 50 times higher than that at the basolateral membrane. In contrast to this active transport of sugar, LLC-PK1 cells did not demonstrate oxalate uptake either at the apical or basolateral plasma membrane. The apical-to-basolateral (A- \u3e B) flux of oxalate in LLC-PK1 cells was identical to the basolateral-to-apical (B- \u3e A) oxalate flux in these cells. Moreover these flux characteristics were similar to those found for D-mannitol, indicating paracellular movement for both compounds. From these data, it is concluded that, under the experimental conditions used, LLC-PK1 cells do not exhibit a specific transcellular transport system for oxalate