CTCF loss has limited effects on global genome architecture in Drosophila despite critical regulatory functions.

Vertebrate genomes are partitioned into contact domains defined by enhanced internal contact frequency and formed by two principal mechanisms: compartmentalization of transcriptionally active and inactive domains, and stalling of chromosomal loop-extruding cohesin by CTCF bound at domain boundaries. While Drosophila has widespread contact domains and CTCF, it is currently unclear whether CTCF-dependent domains exist in flies. We genetically ablate CTCF in Drosophila and examine impacts on genome folding and transcriptional regulation in the central nervous system. We find that CTCF is required to form a small fraction of all domain boundaries, while critically controlling expression patterns of certain genes and supporting nervous system function. We also find that CTCF recruits the pervasive boundary-associated factor Cp190 to CTCF-occupied boundaries and co-regulates a subset of genes near boundaries together with Cp190. These results highlight a profound difference in CTCF-requirement for genome folding in flies and vertebrates, in which a large fraction of boundaries are CTCF-dependent and suggest that CTCF has played mutable roles in genome architecture and direct gene expression control during metazoan evolution

Activation of Human T-Helper/Inducer Cell, T-Cytotoxic Cell, B-Cell, and Natural Killer (NK)-Cells and induction of Natural Killer Cell Activity against K562 Chronic Myeloid Leukemia Cells with Modified Citrus Pectin

<p>Abstract</p> <p>Background</p> <p>Modified citrus pectin (MCP) is known for its anti-cancer effects and its ability to be absorbed and circulated in the human body. In this report we tested the ability of MCP to induce the activation of human blood lymphocyte subsets like T, B and NK-cells.</p> <p>Methods</p> <p>MCP treated human blood samples were incubated with specific antibody combinations and analyzed in a flow cytometer using a 3-color protocol. To test functionality of the activated NK-cells, isolated normal lymphocytes were treated with increasing concentrations of MCP. Log-phase PKH26-labeled K562 leukemic cells were added to the lymphocytes and incubated for 4 h. The mixture was stained with FITC-labeled active form of caspase 3 antibody and analyzed by a 2-color flow cytometry protocol. The percentage of K562 cells positive for PKH26 and FITC were calculated as the dead cells induced by NK-cells. Monosaccharide analysis of the MCP was performed by high-performance anion-exchange chromatography with pulse amperometric detection (HPAEC-PAD).</p> <p>Results</p> <p>MCP activated T-cytotoxic cells and B-cell in a dose-dependent manner, and induced significant dose-dependent activation of NK-cells. MCP-activated NK-cells demonstrated functionality in inducing cancer cell death. MCP consisted of oligogalacturonic acids with some containing 4,5-unsaturated non-reducing ends.</p> <p>Conclusions</p> <p>MCP has immunostimulatory properties in human blood samples, including the activation of functional NK cells against K562 leukemic cells in culture. Unsaturated oligogalacturonic acids appear to be the immunostimulatory carbohydrates in MCP.</p

Auxiliary gauge mediation: a new route to mini-split supersymmetry

The discovery of a standard-model-like Higgs at 126 GeV and the absence of squark signals thus far at the LHC both point towards a mini-split spectrum for supersymmetry. Within standard paradigms, it is non-trivial to realize a mini-split spectrum with heavier sfermions but lighter gauginos while simultaneously generating Higgs sector soft terms of the correct magnitude, suggesting the need for new models of supersymmetry breaking and mediation. In this paper, we present a new approach to mini-split model building based on gauge mediation by “auxiliary groups”, which are the anomaly-free continuous symmetries of the standard model in the limit of vanishing Yukawa couplings. In addition to the well-known flavor SU(3) [subscript F] and baryon-minus-lepton U(1) [subscript B−L] groups, we find that an additional U(1) [subscript H] acting on the Higgs doublets alone can be used to generate Higgs soft masses and B-terms necessary for a complete model of mini-split. Auxiliary gauge mediation is a special case of Higgsed gauge mediation, and we review the resulting two-loop scalar soft terms as well as three-loop gaugino masses. Along the way, we present a complete two-loop calculation of A-terms and B-terms in gauge mediation, which — contrary to a common misconception — includes a non-zero contribution at the messenger threshold which can be sizable in models with light gauginos. We present several phenomenologically acceptable mini-split spectra arising from auxiliary gauge mediation and highlight a complete minimal model which realizes the required spectrum and Higgs sector soft terms with a single U(1) [subscript X] auxiliary gauge symmetry. We discuss possible experimental consequences.United States. Dept. of Energy (Cooperative Research Agreement DE-FG02-05ER-41360)National Science Foundation (U.S.). Graduate Research Fellowship ProgramSimons Foundation (Postdoctoral Fellowship)United States. Dept. of Energy (Early Career Research Program DE-FG02-11ER-41741

Significant quantum effects in hydrogen activation

Dissociation of molecular hydrogen is an important step in a wide variety of chemical, biological, and physical processes. Due to the light mass of hydrogen, it is recognized that quantum effects are often important to its reactivity. However, understanding how quantum effects impact the reactivity of hydrogen is still in its infancy. Here, we examine this issue using a well-defined Pd/Cu(111) alloy that allows the activation of hydrogen and deuterium molecules to be examined at individual Pd atom surface sites over a wide range of temperatures. Experiments comparing the uptake of hydrogen and deuterium as a function of temperature reveal completely different behavior of the two species. The rate of hydrogen activation increases at lower sample temperature, whereas deuterium activation slows as the temperature is lowered. Density functional theory simulations in which quantum nuclear effects are accounted for reveal that tunneling through the dissociation barrier is prevalent for H2 up to ∼190 K and for D2 up to ∼140 K. Kinetic Monte Carlo simulations indicate that the effective barrier to H2 dissociation is so low that hydrogen uptake on the surface is limited merely by thermodynamics, whereas the D2 dissociation process is controlled by kinetics. These data illustrate the complexity and inherent quantum nature of this ubiquitous and seemingly simple chemical process. Examining these effects in other systems with a similar range of approaches may uncover temperature regimes where quantum effects can be harnessed, yielding greater control of bond-breaking processes at surfaces and uncovering useful chemistries such as selective bond activation or isotope separation

Investments in Gas Pipelines and Liquefied Natural Gas Infrastructure. What is the Impact on the Security of Supply?

This paper addresses the question of the infrastructure investment required for gas pipeline and liquefied natural gas (LNG) connections to meet growing gas demand in an enlarged EU over the next 20 years. Several issues are presented, bearing in mind the major objective of the security of supply for EU countries. First, to set the scene, recent projections of gas demand in an enlarged EU are presented along with the corresponding need for additional imports. Then a scenario is developed showing possible supply routes to meet the import gap, relying on increasingly remote routes. An impressive bill of $150 to 200 billion will have to be paid for extending and building the required infrastructure in pipeline links and LNG-receiving facilities. The expected major development of LNG markets is subject to a particular discussion, as far as the progressive globalisation of this market and its inherent flexibility provide major advantages in terms of the security of supply, despite more costly infrastructure than pipeline links. The impact of technological progress is expected to reduce both capital investment and unit transport costs, offering access to new supply opportunities. Finally, the question of major obstacles to the realisation of the required huge investments in gas infrastructure over the next 20 years is addressed, opening hot debate on the subjects of future gas price, market liberalisation and financing issues

Equilibrium with a Market of Permits

In this paper we present the main results of three original studies on the equilibrium with a market of tradeable permits in a static framework. In first study, we have considered an international equilibrium of two countries which depend on the quantity of permits to each country. The allocation is efficient if and only if it is proportional to efficient labor. A redistribution in favor of the less developed country implies a redistribution to this country but leads to a dilemma with efficiency. In the second study, we analyze the consequences of the choice between giving free permits to firms and other possibilities. We show that for equalizing incomes of production factors with there marginal productivities, each factor should receive a quantity of free permits proportional to its contribution to production. In the third study, we consider the partial equilibrium of an industry where each firm is characterized by a parameter combining production efficiency and pollution effect. We define a theoretical indicator of environmental efficiency and we analyze its properties

A Climate-Change Policy Induced Shift from Innovations in Energy Production to Energy Savings

We develop an endogenous growth model with capital, labor and energy as production factors and three productivity variables that measure accumulated innovations for energy production, energy savings, and neutral growth. All markets are complete and perfect, except for research, for which we assume that the marginal social value exceeds marginal costs by factor four. The model constants are calibrated so that the model reproduces the relevant trends over the 1970-2000 period. The model contains a simple climate module, and is used to assess the impact of Induced Technological Change (ITC) for a policy that aims at a maximum level of atmospheric CO2 concentration (450 ppmv). ITC is shown to reduce the required carbon tax by about a factor 2, and to reduce costs of such a policy by about factor 10. Numerical simulations show that knowledge accumulation shifts from energy production to energy saving technology

Application of Technological Control Measures on Vehicle Pollution: A Cost-Benefit Analysis in China

For the past two decades, China has experienced strong, continuous economic growth. At the same time, the number of motor vehicles in China has rapidly increased. As a direct result of such a phenomenon, China has been registering significant increases in air pollution. In spite of recent advances in air pollution control, it remains a serious problem for Chinas major cities, and constitutes an important issue in the agenda of its policy makers. The object of this paper is to explore the use of cost-benefit analysis (CBA) to evaluate and rank alternative policy scenarios regarding the control of air pollution emitted by motor vehicles. The empirical analysis carried out relates specifically to the Chinese context, over a twenty year period, from 2001 to 2020, and focuses on emission changes of the following three principal pollutants: CO, HC and NOx