170,161 research outputs found
Groupe A4. - Production alimentaire et marketing, en relation avec les problèmes régionaux
No full textCsaki C., Dimou Elefthéria. Groupe A4. - Production alimentaire et marketing, en relation avec les problèmes régionaux. In: Économie rurale. N°150-151, 1982. Agriculture et développement régional en Europe, sous la direction de Louis P. Mahé. pp. 91-95
SMALL FARMS IN CENTRAL AND EASTERN EUROPE: IS THERE A FUTURE FOR THEM?
No full textAgribusiness, Agricultural and Food Policy, Consumer/Household Economics, Land Economics/Use,
TOWARDS A REALISTIC MODEL OF HIGGSLESS ELECTROWEAK SYMMETRY BREAKING
No full textWe present a 5D gauge theory in warped space based on a bulk SU(2)L×SU(2)R×U(1)B-L gauge group where the gauge symmetry is broken by boundary conditions. The symmetry breaking pattern and the mass spectrum resemble that in the standard model (SM). To leading order in the warp factor the ρ parameter and the coupling of the Z (S parameter) are as in the SM, while corrections are expected at the level of a percent. From the anti–de Sitter (AdS) conformal field theory point of view the model presented here can be viewed as the AdS dual of a (walking) technicolorlike theory, in the sense that it is the presence of the IR brane itself that breaks electroweak symmetry, and not a localized Higgs on the IR brane (which should be interpreted as a composite Higgs model). This model predicts the lightest W, Z, and γ resonances to be at around 1.2 TeV, and no fundamental (or composite) Higgs particles
The super-little Higgs
No full textSupersymmetry combined with little Higgs can render the Higgs vacuum expectation value super-little, providing models of electroweak symmetry breaking free from fine-tunings. We discuss the difficulties that arise in implementing this idea and propose one simple successful model. Thanks to appropriately chosen Higgs representations, D-terms give a negligible tree-level mass term to the Goldstone. The fermion representations are anomaly free, generation independent, and embeddable into an SU(6) grand unified theory. A simple mechanism provides the large top quark mass
The minimal set of electroweak precision parameters
No full textWe present a simple method for analyzing the impact of precision electroweak data above and below the Z peak on flavor-conserving, heavy new physics. We find that experiments have probed about ten combinations of new-physics effects, which to a good approximation can be condensed into the effective oblique parameters S, T, U, V, X, W, Y (we prove positivity constraints W,Y >= 0) and three combinations of quark couplings (including a distinct parameter for the bottom). We apply our method to generic extra Z(') vectors
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
On the dynamical origin of the η ′ potential and the axion mass
No full textWe investigate the dynamics responsible for generating the potential of the η ′, the (would-be) Goldstone boson associated with the anomalous axial U(1) symmetry of QCD. The standard lore posits that pure QCD dynamics generates a confining potential with a branched structure as a function of the θ angle, and that this same potential largely determines the properties of the η ′ once fermions are included. Here we test this picture by examining a supersymmetric extension of QCD with a small amount of supersymmetry breaking generated via anomaly mediation. For pure SU(N) QCD without flavors, we verify that there are N branches generated by gaugino condensation. Once quarks are introduced, the flavor effects qualitatively change the strong dynamics of the pure theory. For F flavors we find |N − F| branches, whose dynamical origin is gaugino condensation in the unbroken subgroup for F < N – 1, and in the dual gauge group for F > N + 1. For the special cases of F = N – 1, N, N + 1 we find no branches and the entire potential is consistent with being a one-instanton effect. The number of branches is a simple consequence of the selection rules of an anomalous U(1) R symmetry. We find that the η ′ mass does not vanish in the large N limit for fixed F/N, since the anomaly is non-vanishing. The same dynamics that is responsible for the η ′ potential is also responsible for the axion potential. We present a simple derivation of the axion mass formula for an arbitrary number of flavors
Mitomycin C in highly myopic eyes - Author reply
No full textOphthalmology. 2005 Feb;112(2):208-18; discussion 219.
Mitomycin C modulation of corneal wound healing after photorefractive keratectomy in highly myopic eyes.
Gambato C, Ghirlando A, Moretto E, Busato F, Midena E.
SourceRefractive Surgery Service and Antimetabolite Therapy Research Unit, Department of Ophthalmology, University of Padova, Padova, Italy.
Abstract
PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes.
DESIGN: Prospective, double-masked, randomized clinical trial.
PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia.
METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months).
MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH.
RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively).
CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK.
Comment in
Ophthalmology. 2006 Feb;113(2):357; author reply 357-8
Agriculture and the transition to the market
No full textAgricultural sectors in Eastern and Central Europe are large so that changes in producer prices, farm employment, and land ownership affect substantial numbers of people. In the past, food in the region was politicized. For decades, governments of Eastern European countries and the USSR offered their citizens stable, subsidized food prices and a steadily improving diet in an effort to demonstrate the superiority of communism over capitalism. During the transition, the context has changed, but food remains politicized. Many consumers in the region are ill-prepared to pay the real costs of food, which are quite high. The task of reducing those costs will be difficult, involving restructuring of farms and fostering competition in processing and distribution. Management of the agricultural transition will affect the political sustainability of the process and influence agriculture's contribution to the growth of emerging market economies. Although the agricultural sector of Eastern and Central Europe is large, Soviet agriculture dwarfs it in its impact on the region and the world. A positive program to stop the decline in Soviet agriculture could contribute to economic growth and political stability. Failure to remedy the fundamental flaws in Soviet agriculture will speed the country's slide into poverty and ethnic turmoil - and undermine the efforts of Central and Eastern Europeans to succeed.Access to Markets,Environmental Economics&Policies,Economic Theory&Research,Agricultural Knowledge&Information Systems,Markets and Market Access
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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