Uncertainty Principle Enhanced Pairing Correlations in Projected Fermi Systems Near Half Filling

We point out the curious phenomenon of order by projection in a class of lattice Fermi systems near half filling. Enhanced pairing correlations of extended s-wave Cooper pairs result from the process of projecting out s-wave Cooper pairs, with negligible effect on the ground state energy. The Hubbard model is a particularly nice example of the above phenomenon, which is revealed with the use of rigorous inequalities including the Uncertainty Principle Inequality. In addition, we present numerical evidence that at half filling, a related but simplified model shows ODLRO of extended s-wave Cooper pairs.Comment: RevTex 11 pages + 1 ps figure. Date 19 September 1996, Ver.

Nonrenormalization of Flux Superpotentials in String Theory

Recent progress in understanding modulus stabilization in string theory relies on the existence of a non-renormalization theorem for the 4D compactifications of Type IIB supergravity which preserve N=1 supersymmetry. We provide a simple proof of this non-renormalization theorem for a broad class of Type IIB vacua using the known symmetries of these compactifications, thereby putting them on a similar footing as the better-known non-renormalization theorems of heterotic vacua without fluxes. The explicit dependence of the tree-level flux superpotential on the dilaton field makes the proof more subtle than in the absence of fluxes.Comment: 16 pages, no figures. Final version, to appear in JHEP. Arguments for validity of R-symmetry made more explicit. Minor extra comments and references adde

Scientific Opinion on a technical file submitted by the US Authorities to support a request to list a new opinion among the EU import requirements for wood of Agrilus planipennis host plants.

This document presents the scientific opinion of the Panel on Plant Health on the technical file submitted by the US Authorities to support a request to list a new option among the EU import requirements for wood of Agrilus planipennis host plants. The option under consideration is a heat treatment at 60 °C for 60 min to liminate possible infestations of the wood by the emerald ash borer (EAB). The experiments leading the US Authorities to propose this option are presented in a scientific peer reviewed publication, Myers et al. (2009). The analysis of the aggregated data published by Myers et al. (2009) and based on a Probit regression model showed that the proposed treatment cannot guarantee a control level of 99 % or higher. The analysis of the individual data either from the original measurements or from a corrected dataset, using a Probit regression model, showed that it is likely to observe one live EAB out of an infestation of 100 after the proposed heat treatment of 60 °C /60 min. To ensure a control level of 99 % the temperature of the heat treatment of 60 min should be higher than 70 °C. Results obtained with a Poisson log linear model based on individual data showed that the estimated probability that one insect or more per m2 survive the proposed heat treatment was higher than 0.6 and that there is a 0.1 probability that three insects or more per m2 survive the proposed heat treatment. Based on these results, the Panel concludes that A. planipennis is likely to survive the proposed heat treatment of 60 °C/60 min with a low uncertainty, and that the alternative option proposed in the technical file submitted by the US Authorities for wood does not guarantee the wood to be free of A. planipennis

Statement on the dossier for a derogation request for the US authorities concerning cold-treated strawberry plants intended for planting.

Following a request from the European Commission, the EFSA Panel on Plant Health examined the report “Evaluation of Strawberry Nursery Plant Cold Treatments on Survival of the Whitefly, Bemisia tabaci”, submitted to the European Commission by the United States Department of Agriculture (USDA). The report serves as technical justification for a derogation from requirements listed in Annex IV, Part A, Section 1, point 46 of the Council Directive 2000/29/EC. The Panel concluded that due to shortcomings in the report itself and in the experimental design of the study, this report does not demonstrate the effectiveness of the cold treatment proposed for the elimination of B. tabaci from strawberry plant consignments prepared for shipment to the EU. In addition, the Panel conducted a preliminary review of the available literature on viruses of strawberry and concluded that no B. tabaci‐transmitted viruses are currently known to infect strawberry and that no viruses of Fragaria listed in European Council Directive 2000/29/EC are known to be transmitted by B. tabaci. However, adult whiteflies of B. tabaci on strawberry consignments can carry plant viruses irrespective of whether strawberry is a host plant for these viruses and thus represent a pathway for the introduction of non‐European viruses. There is also some uncertainty concerning the extent to which known or unknown B. tabaci‐transmitted viruses could infect strawberry. Irrespective of the presence of B. tabaci, strawberry transplants from the US may represent a pathway for the introduction of any non‐European virus (and other potentially harmful organisms) of Fragaria

Scientific Opinion on the assessment of the risk of solanaceous pospiviroids for the EU territory and the identification and evaluation of risk management options.

Following a request from the EU Commission, the EFSA PLH Panel conducted a risk assessment for the EU territory of pospiviroids affecting solanaceous crops, identified and evaluated risk reduction options and evaluated the EU provisional emergency measures targeting Potato spindle tuber viroid (PSTVd). The risk assessment included PSTVd, Citrus exocortis viroid, Columnea latent viroid, Mexican papita viroid, Tomato apical stunt viroid, Tomato chlorotic dwarf viroid, Tomato planta macho viroid, Chrysanthemum stunt viroid and Pepper chat fruit viroid. Four entry pathways were identified, three involving plant propagation material, with moderate probability of entry, and one involving plant products for human consumption, with low probability of entry. The probability of establishment was considered very high. Spread was considered likely within a crop and moderately likely between crop species, with exception of spread to potato, rated as unlikely. The probability of long distance spread within vegetatively propagated crops was estimated as likely/very likely. The direct consequences were expected to be major in potato and tomato, moderate in pepper, minimal/minor in other vegetables and minimal in ornamentals. Main risk assessment uncertainties derive from limited knowledge on pospiviroids other than PSTVd, although all pospiviroids are expected to have similar biological properties. Management options to reduce risk of entry, spread and consequences were identified and evaluated. No management options can prevent establishment. Examples of successful PSTVd eradication are linked to timely and strict implementation of measures. Uncertainty exists on the effectiveness of risk reduction strategies targeting only one pathway. The EU provisional emergency measures appeared to have significantly reduced PSTVd incidence in Solanum jasminoides and Brugmansia sp., even though eradication from the EU is so far incomplete. The low PSTVd incidence in food crops did not permit to conclude whether the reduction in PSTVd prevalence in ornamentals led to a reduction in outbreaks in food crops

Scientific Opinion on the effect on public or animal health or on the environment on the presence of seeds of Ambrosia spp. in animal feed

The European Commission requested EFSA to provide a scientific opinion on the effect on public or animal health or on the environment on the further distribution of Ambrosia spp. in the European Union and on the importance of feed materials, in particular bird feed, in the dispersion of Ambrosia spp. The genus Ambrosia (Asteraceae family) is distributed worldwide. Ambrosia artemisiifolia (common ragweed) has heavily colonised several areas of South-East Europe. Ambrosia spp., both in their native range and in invaded areas, are of public health concern due to the allergenic properties of their pollen. The NDA Panel concluded that inhalation of the plant pollen causes rhino-conjunctivitis and asthma, with skin allergies and food allergy playing minor roles. Ambrosia may cross-sensitize patients to other allergens, including food allergens. There is some evidence for allergenicity of Ambrosia pollen in animals. With regard to the effects on the environment of the further distribution of Ambrosia spp. in the European Union, the PLH Panel concluded that there is no direct evidence that Ambrosia spp. cause extinction of plant species. However, there are some indications that A. artemisiifolia could become highly invasive in certain environmentally-valuable habitats and might be linked to an impoverishment of species richness, therefore further ecological studies are needed. The CONTAM Panel focused on the relative importance of animal feed, bird feed in particular, on the dispersion of Ambrosia. Ambrosia seeds may contaminate feed. However, animal feed materials compounded for use in livestock are extensively processed. This processing destroys Ambrosia seeds and hence the contribution of compounded feed to the dispersion of Ambrosia is considered to be negligible. Bird feed often contains significant quantities of Ambrosia seeds and remains unprocessed. Therefore, bird feed seems to play an important role in introducing Ambrosia to new, previously not infested areas

Statement on a study proposal prepared by the UC to support a future derogation request from the EU import requirements for wood packaging material originating in the US and used to pack and transport military ammunition. Scientific Opinion.

Following a request from the European Commission, the EFSA Panel on Plant Health was asked to deliver a statement on a study proposal prepared by the US to support a future derogation request from the Community import requirements for wood packaging material (WPM) originating in the US and used to pack and transport military ammunition. The Panel reviewed the submitted study proposal and based its conclusions on the shortcomings identified in the study proposal. It was concluded that, due to these shortcomings, the evaluation of the methodological approach described in this study proposal with regard to: 1.the determination of the likelihood that live pinewood nematode (Bursaphelenchus xylophilus) and other harmful organisms relevant for the Community are present in the WPM used by the US Department of Defense to pack and transport military ammunition (Pest survey component), 2. the assessment of the likelihood that harmful organisms may be introduced into the Community through the WPM pathway (Pathway Risk Analysis component) cannot be conducted

Dynamical Stability of Six-Dimensional Warped Brane-Worlds

We study a generalization of the Randall-Sundrum mechanism for generating the weak/Planck hierarchy, which uses two rather than one warped extra dimension, and which requires no negative tension branes. A 4-brane with one exponentially large compact dimension plays the role of the Planck brane. We investigate the dynamical stability with respect to graviton, graviphoton and radion modes. The radion is shown to have a tachyonic instability for certain models of the 4-brane stress-energy, while it is stable in others, and massless in a special case. If stable, its mass is in the milli-eV range, for parameters of the model which solve the hierarchy problem. The radion is shown to couple to matter with gravitational strength, so that it is potentially detectable by submillimeter-range gravity experiments. The radion mass can be increased using a bulk scalar field in the manner of Goldberger and Wise, but only to order MeV, due to the effect of the large extra dimension. The model predicts a natural scale of 10^{13} GeV on the 4-brane, making it a natural setting for inflation from the ultraviolet brane.Comment: 28 pages, 7 figure

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field