POTENTIAL INCOME EFFECTS OF THE HARKIN-GEPHARDT PROPOSAL ON NEW YORK DAIRY FARMS

This article reports the results of research regarding the farm-level implications for New York dairy producers of national mandatory supply control programs for feed grains and milk. The analysis is based on the proposed Harkin-Gephardt Bill which would authorize a mandatory supply control program for milk and the major supported crops. Representative farm budgets were constructed for a sample of dairy farms to assess the possible effects on costs and returns. Some farmers would gain, while others would not. The results suggest that dairy farmers who purchase all of their feed would be worse off, while farmers who grow grain would be better off under the proposed supply control program.Agricultural Finance,

Least-squares methods for identifying biochemical regulatory networks from noisy measurements

<b>Background</b>: We consider the problem of identifying the dynamic interactions in biochemical networks from noisy experimental data. Typically, approaches for solving this problem make use of an estimation algorithm such as the well-known linear Least-Squares (LS) estimation technique. We demonstrate that when time-series measurements are corrupted by white noise and/or drift noise, more accurate and reliable identification of network interactions can be achieved by employing an estimation algorithm known as Constrained Total Least Squares (CTLS). The Total Least Squares (TLS) technique is a generalised least squares method to solve an overdetermined set of equations whose coefficients are noisy. The CTLS is a natural extension of TLS to the case where the noise components of the coefficients are correlated, as is usually the case with time-series measurements of concentrations and expression profiles in gene networks. <b>Results</b>: The superior performance of the CTLS method in identifying network interactions is demonstrated on three examples: a genetic network containing four genes, a network describing p53 activity and <i>mdm2</i> messenger RNA interactions, and a recently proposed kinetic model for interleukin (IL)-6 and (IL)-12b messenger RNA expression as a function of ATF3 and NF-κB promoter binding. For the first example, the CTLS significantly reduces the errors in the estimation of the Jacobian for the gene network. For the second, the CTLS reduces the errors from the measurements that are corrupted by white noise and the effect of neglected kinetics. For the third, it allows the correct identification, from noisy data, of the negative regulation of (IL)-6 and (IL)-12b by ATF3. <b>Conclusion</b>: The significant improvements in performance demonstrated by the CTLS method under the wide range of conditions tested here, including different levels and types of measurement noise and different numbers of data points, suggests that its application will enable more accurate and reliable identification and modelling of biochemical networks

Newcastle upon Tyne, the Eye of the North

Newcastle upon Tyne is one of England’s great cities. Many think of it mainly as a product of the Industrial Revolution when abundant resources of coal, iron ore and water came together to create a Victorian industrial powerhouse. In fact, Newcastle’s long and proud history began in Roman times when Hadrian’s Wall marked the northernmost point of the Roman Empire.Newcastle became a thriving medieval port, with trading connections around the North Sea, the Atlantic, the Baltic countries and the Mediterranean. By the mid-17th century, Newcastle was not only a major European port, but was also becoming the pre-eminent exporter of coal fuelling the incipient industrial revolution. This volume brings together the archaeological evidence for occupation in the historic core of Newcastle between the prehistoric period and 1650. It places the evidence in the context of the evolving historical communities who made and occupied the site, and in the wider context of medieval and early modern European urban life.The volume synthesizes archaeological and historical evidence, highlighting material only known through excavation – like the early medieval use of the decaying Roman fort for a cemetery and probable church – as well as throwing new light on documented activities – like the way in which the waterfront was physically extended and consolidated to support trade from the 12th century onwards. Taking its name from a castle of national significance, planted after the Norman Conquest as a bulwark against Northern rebels and Scottish aggression, Newcastle was established as the king’s ‘Eye of the North’

Newcastle upon Tyne, the Eye of the North

Newcastle upon Tyne is one of England’s great cities. Many think of it mainly as a product of the Industrial Revolution when abundant resources of coal, iron ore and water came together to create a Victorian industrial powerhouse. In fact, Newcastle’s long and proud history began in Roman times when Hadrian’s Wall marked the northernmost point of the Roman Empire.Newcastle became a thriving medieval port, with trading connections around the North Sea, the Atlantic, the Baltic countries and the Mediterranean. By the mid-17th century, Newcastle was not only a major European port, but was also becoming the pre-eminent exporter of coal fuelling the incipient industrial revolution. This volume brings together the archaeological evidence for occupation in the historic core of Newcastle between the prehistoric period and 1650. It places the evidence in the context of the evolving historical communities who made and occupied the site, and in the wider context of medieval and early modern European urban life.The volume synthesizes archaeological and historical evidence, highlighting material only known through excavation – like the early medieval use of the decaying Roman fort for a cemetery and probable church – as well as throwing new light on documented activities – like the way in which the waterfront was physically extended and consolidated to support trade from the 12th century onwards. Taking its name from a castle of national significance, planted after the Norman Conquest as a bulwark against Northern rebels and Scottish aggression, Newcastle was established as the king’s ‘Eye of the North’

On Four-Point Functions of Half-BPS Operators in General Dimensions

We study four-point correlation functions of half-BPS operators of arbitrary weight for all dimensions d=3,4,5,6 where superconformal theories exist. Using harmonic superspace techniques, we derive the superconformal Ward identities for these correlators and present them in a universal form. We then solve these identities, employing Jack polynomial expansions. We show that the general solution is parameterized by a set of arbitrary two-variable functions, with the exception of the case d=4, where in addition functions of a single variable appear. We also discuss the operator product expansion using recent results on conformal partial wave amplitudes in arbitrary dimension.Comment: The discussion of the case d=6 expanded; references added/correcte

Quantum Gravity from Conformal Field Theory

We bootstrap loop corrections to AdS5 supergravity amplitudes by enforcing the consistency of the known classical results with the operator product expansion of NN = 4 super Yang-Mills theory. In particular this yields much new information on the spectrum of double-trace operators which can then be used, in combination with superconformal symmetry and crossing symmetry, to obtain a prediction for the one-loop amplitude for four graviton multiplets in AdS. This in turn yields further new results on subleading O(1/N 4) corrections to certain double-trace anomalous dimensions

Conjectures for Large N Superconformal N=4 Chiral Primary Four Point Functions

An expression for the four point function for half-BPS operators belonging to the [0,p,0] SU(4) representation in N=4 superconformal theories at strong coupling in the large N limit is suggested for any p. It is expressed in terms of the four point integrals defined by integration over AdS_5 and agrees with, and was motivated by, results for p=2,3,4 obtained via the AdS/CFT correspondence. Using crossing symmetry and unitarity, the detailed form is dictated by the requirement that at large N the contribution of long multiplets with twist less than 2p, which do not have anomalous dimensions, should cancel corresponding free field contributions.Comment: 50 pages, 1 figure, uses harvmac, version 2 extra reference, minor change

Superconformal Symmetry, Correlation Functions and the Operator Product Expansion

Superconformal transformations are derived for the $\N=2,4 supermultiplets corresponding to the simplest chiral primary operators. These are applied to two, three and four point correlation functions. When$\N=4$, results are obtained for the three point function of various descendant operators, including the energy momentum tensor and SU(4) current. For both$\N=2$ or 4 superconformal identities are derived for the functions of the two conformal invariants appearing in the four point function for the chiral primary operator. These are solved in terms of a single arbitrary function of the two conformal invariants and one or three single variable functions. The results are applied to the operator product expansion using the exact formula for the contribution of an operator in the operator product expansion in four dimensions to a scalar four point function. Explicit expressions representing exactly the contribution of both long and possible short supermultiplets to the chiral primary four point function are obtained. These are applied to give the leading perturbative and large N corrections to the scale dimensions of long supermultiplets.Comment: 75 pages, plain TeX file using harvmac; revised version, minor corrections and extra referenc

On Short and Semi-Short Representations for Four Dimensional Superconformal Symmetry

Possible short and semi-short representations for $\N=2$ and $\N=4$ superconformal symmetry in four dimensions are discussed. For $\N=4$ the well known short supermultiplets whose lowest dimension conformal primary operators correspond to \half-BPS or ${1\over 4}$-BPS states and are scalar fields belonging to the $SU(4)_r$ symmetry representations $[0,p,0]$ and $[q,p,q]$ and having scale dimension $\Delta =p$ and $\Delta = 2q+p$ respectively are recovered. The representation content of semi-short multiplets, which arise at the unitarity threshold for long multiplets, is discussed. It is shown how, at the unitarity threshold, a long multiplet can be decomposed into four semi-short multiplets. If the conformal primary state is spinless one of these becomes a short multiplet. For $\N=4$ a ${1\over 4}$-BPS multiplet need not have a protected dimension unless the primary state belongs to a $[1,p,1]$ representation.Comment: 54 pages, plain TeX file using harvma