The permanence debate

E. Kintisch (“Deforestation moves to the fore in Copenhagen,” News of the Week, 11 December 2009, p. 1465) identifies a number of issues hindering an agreement on Reducing Emissions from Deforestation and Forest Degradation (REDD). However, he does not mention permanence, which has dogged the REDD discussions for some time (1). Many negotiators fear that reductions in loss of forest carbon stocks may be credited and rewarded now, but that the forest may later disappear (whether cut or affected by die-off due to climate changes). They contrast this scenario with that of fossil fuels, for which they argue that savings are permanent. This argument is flawed. There is a finite quantity of fossil fuel underground. Clean technology slows the rate at which it is extracted and burned, but eventually it will all be converted to CO2. REDD will slow the rate at which carbon is emitted from forests in an analogous way. The conceptual muddle about permanence occurs when people confuse “stocks” with the “rate of change of stocks.” Reduced emissions from deforestation and forest degradation are, like fossil fuel reductions, calculated on the basis of lowered annual losses compared to business as usual, not on the basis of stock remaining. There is only one difference between stocks of fossil carbon and stocks of living carbon, in terms of permanence. Carbon lost due to deforestation or forest degradation in one place can be replaced by reforestation or enhancing carbon stocks in degraded forests elsewhere, whereas fossil fuels cannot be replaced at all

Light-Modulated Self-Blockage of a Urea Binding Site in a Stiff-Stilbene Based Anion Receptor

Anion binding to a receptor based on stiff‐stilbene, which is equipped with a urea hydrogen bond donating group and a phosphate or phosphinate hydrogen bond accepting group, can be controlled by light. In one photoaddressable state (E isomer) the urea binding site is available for binding, while in the other (Z isomer) it is blocked because of an intramolecular interaction with its hydrogen bond accepting motif. This intramolecular interaction is supported by DFT calculations and 1H NMR titrations reveal a significantly lower anion binding strength for the state in which anion binding is blocked. Furthermore, the molecular switching processhas been studied in detail by UV/Vis and NMR spectroscopy. The presented approach opens up new opportunities toward the development of photoresponsive anion receptors.Supramolecular & Biomaterials Chemistr

One-pot, modular approach to functionalized ketones via nucleophilic addition/Buchwald-Hartwig amination strategy

A general one-pot procedure for the 1,2-addition of organolithium reagents to amides followed by the Buchwald-Hartwig amination with in situ released lithium amides is presented. In this work amides are used as masked ketones, revealed by the addition of organolithium reagents which generates a lithium amide, suitable for subsequent Buchwald-Hartwig coupling in the presence of a palladium catalyst. This methodology allows for rapid, efficient and atom economic synthesis of aminoarylketones in good yields

Between a Rock and a Hard Place: The Precarious State of a Double Agent during the Cold War

While scholarly literature has paid attention to human intelligence professionalism from the perspective of the agent handler, we know relatively little about the precarious positions in which (double) agents often find themselves and what their ensuing needs from their handlers consist of. This article suggests that (double) agents desire a reciprocal, affect-based relationship with their handlers, involving trust and gratitude, more than just a negotiated relationship based on (financial) agreements. This article explains the importance of such a relationship. The main source of this research consists of original, in-depth oral history interviews with former double agent “M.” He operated from the 1960s through the 1990s for the Dutch Security Service and the Central Intelligence Agency against the East German Ministerium für Staatssicherheit. The article analyzes the varying degrees of appreciation that these services showed for his work, and it investigates their consequences on the psychological well-being of the double agent

Dendritic cell-mediated HIV-1 transmission to T cells of LAD-1 patients is impaired due to the defect in LFA-1

BACKGROUND: Dendritic cells (DC) have been proposed to mediate sexual HIV-1 transmission by capturing the virus in the mucosa and subsequently presenting it to CD4(+ )T cells. We have demonstrated before that DC subsets expressing higher levels of intercellular adhesion molecule-1 (ICAM-1) are better HIV-1 transmitters. ICAM-1 binds leukocyte function-associated molecule-1 (LFA-1) on T cells, an integrin responsible for adhesion and signaling at the immunological synapse. To corroborate the importance of the ICAM-1— LFA-1 interaction, we performed transmission experiments to LFA-1 negative leukocytes from Leukocyte Adhesion Deficiency type 1 (LAD-1) patients. RESULTS: We clearly show that DC-mediated HIV-1 transmission to LAD-1 T cells is impaired in comparison to healthy controls. Furthermore, HIV-1 transmission to T cells from a unique LAD-1 patient with a well characterized LFA-1 activation defect was impaired as well, demonstrating that activation of LFA-1 is crucial for efficient transmission. Decreased cell adhesion between DC and LAD-1 T cells could also be illustrated by significantly smaller DC-T cell clusters after HIV-1 transmission. CONCLUSION: By making use of LFA-1 defect cells from unique patients, this study provides more insight into the mechanism of HIV-1 transmission by DC. This may offer new treatment options to reduce sexual transmission of HIV-1

A thrips vector of tomato spotted wilt virus responds to tomato acylsugar chemical diversity with reduced oviposition and virus inoculation.

There is increasing evidence that acylsugars deter insect pests and plant virus vectors, including the western flower thrips (WFT), Frankliniella occidentalis (Pergande), vector of tomato spotted wilt virus (TSWV). Acylsugars are sugar-polyesters composed of saturated, un-saturated, and variously branched short and long chain fatty acids (FAs) esterified to a glucose (acylglucose) or sucrose (acylsucrose) moiety. We sought to understand how acylsucrose amount and composition of associated FA profiles interacted to mediate resistance to WFT oviposition and TSWV inoculation on tomato leaves. Towards this goal, we examined WFT oviposition and TSWV inoculation behavior on tomato lines bred to exude varying amounts of acylsucrose in association with diverse FA profiles. Our data show that as acylsucrose amounts increased, WFT egg-laying (oviposition) decreased and TSWV inoculation was suppressed. Western flower thrips also responded to FA profiles that included iC4, iC11, nC12 and nC10 FA. These findings support improving acylsugar-mediated resistance against WFT by breeding tomatoes exuding greater amounts of acylsucrose associated with specific FA profiles. We show that increasing acylsucrose amount output by type IV trichomes and selecting for particular FA profiles through advanced breeding profoundly affects WFT behavior in ways that benefit management of WFT as direct pests and as TSWV vectors

Phosphatidylethanolamine mediates insertion of the catalytic domain of leader peptidase in membranes

AbstractLeader peptidase is an integral membrane protein of E. coli and it catalyses the removal of most signal peptides from translocated precursor proteins. In this study it is shown that when the transmembrane anchors are removed in vivo, the remaining catalytic domain can bind to inner and outer membranes of E. coli. Furthermore, the purified catalytic domain binds to inner membrane vesicles and vesicles composed of purified inner membrane lipids with comparable efficiency. It is shown that the interaction is caused by penetration of a part of the catalytic domain between the lipids. Penetration is mediated by phosphatidylethanolamine, the most abundant lipid in E. coli, and does not seem to depend on electrostatic interactions. A hydrophobic segment around the catalytically important residue serine 90 is required for the interaction with membranes