Public Economic Benefits of Reducing Salinity Discharges: Evidence from California’s San Joaquin Valley

Environmental Economics and Policy,

D-branes in B Fields

The RR Page charges for the D2-, D4-, D6-brane in B fields are constructed explicitly from the equations of motion and the nonvanishing (modified) Bianchi identities by exploiting their properties --- conserved and localized. It is found that the RR Page charges are independent of the backgound B fields, which provides further evidence that the RR Page charge should be quantized. In our construction, it is highly nontrivial that the terms like B x B x B, B x B x F, B x F x F from different sources are exactly cancelled with each other.Comment: 13 pages, latex, version to appear in Nucl. Phys.

String Field Theory Projectors for Fermions of Integral Weight

The interaction vertex for a fermionic first order system of weights (1,0) such as the twisted bc-system, the fermionic part of N=2 string field theory and the auxiliary \eta\xi system of N=1 strings is formulated in the Moyal basis. In this basis, the Neumann matrices are diagonal; as usual, the eigenvectors are labeled by \kappa\in\R. Oscillators constructed from these eigenvectors make up two Clifford algebras for each nonzero value of \kappa. Using a generalization of the Moyal-Weyl map to the fermionic case, we classify all projectors of the star-algebra which factorize into projectors for each \kappa-subspace. At least for the case of squeezed states we recover the full set of bosonic projectors with this property. Among the subclass of ghost number-homogeneous squeezed state projectors, we find a single class of BPZ-real states parametrized by one (nearly) arbitrary function of \kappa. This class is shown to contain the generalized butterfly states. Furthermore, we elaborate on sufficient and necessary conditions which have to be fulfilled by our projectors in order to constitute surface states. As a byproduct we find that the full star product of N=2 string field theory translates into a canonically normalized continuous tensor product of Moyal-Weyl products up to an overall normalization. The divergent factors arising from the translation to the continuous basis cancel between bosons and fermions in any even dimension.Comment: LaTeX, 1+23 pages, minor improvements, references adde

String Field Theory Vertices for Fermions of Integral Weight

We construct Witten-type string field theory vertices for a fermionic first order system with conformal weights (0,1) in the operator formulation using delta-function overlap conditions as well as the Neumann function method. The identity, the reflector and the interaction vertex are treated in detail paying attention to the zero mode conditions and the U(1) charge anomaly. The Neumann coefficients for the interaction vertex are shown to be intimately connected with the coefficients for bosons allowing a simple proof that the reparametrization anomaly of the fermionic first order system cancels the contribution of two real bosons. This agrees with their contribution c=-2 to the central charge. The overlap equations for the interaction vertex are shown to hold. Our results have applications in N=2 string field theory, Berkovits' hybrid formalism for superstring field theory, the \eta\xi-system and the twisted bc-system used in bosonic vacuum string field theory.Comment: 1+28 pages, minor improvements, references adde

BRST construction of D-branes in SU(2) WZW model

BRST construction of $D$-branes in SU(2) WZW model is proposed.Comment: 18 pages, LaTex, minor changes, typos corrected and ref. adde

On surface states and star-subalgebras in string field theory

We elaborate on the relations between surface states and squeezed states. First, we investigate two different criteria for determining whether a matter sector squeezed state is also a surface state and show that the two criteria are equivalent. Then, we derive similar criteria for the ghost sector. Next, we refine the criterion for determining whether a surface state is in H_{\kappa^2}, the subalgebra of squeezed states obeying [S,K_1^2]=0. This enables us to find all the surface states of the H_{\kappa^2} subalgebra, and show that it consists only of wedge states and (hybrid) butterflies. Finally, we investigate generalizations of this criterion and find an infinite family of surface states subalgebras, whose surfaces are described using a "generalized Schwarz-Christoffel" mapping.Comment: 38 pages, 6 figures, JHEP style; typos corrected, ref. adde

Matrix Models and D-branes in Twistor String Theory

We construct two matrix models from twistor string theory: one by dimensional reduction onto a rational curve and another one by introducing noncommutative coordinates on the fibres of the supertwistor space P^(3|4)->CP^1. We comment on the interpretation of our matrix models in terms of topological D-branes and relate them to a recently proposed string field theory. By extending one of the models, we can carry over all the ingredients of the super ADHM construction to a D-brane configuration in the supertwistor space P^(3|4). Eventually, we present the analogue picture for the (super) Nahm construction.Comment: 1+37 pages, reference added, JHEP style, published versio

Glicerina bruta em suplementos para bovinos de corte a pasto no período seco

The objective of this work was to evaluate the effect of the replacement of corn by crude glycerin (CG) on the nutritional parameters and performance of beef cattle grazing Urochloa brizantha 'Marandu' during the dry season. To evaluate ruminal parameters, five non‑fistulated Nelore steers were used, with average initial body weight (BW) of 331.7±29.6 kg, allotted to a 5x5 Latin square. To evaluate performance, 30 steers were used, with average BW of 312.4±23.3 kg, allotted to a completely randomized design. Concentrated supplements (20% crude protein) with 0, 33, 66, and 100% CG replacing corn were evaluated and provided in the amount of 4.0 kg per animal per day. Intake of supplement, total, and pasture dry matter (DM), as well as of digestible organic matter (OM), presented quadratic behavior to the replacement levels. The apparent digestibility of DM, OM, neutral detergent fiber, and digestible OM, as well as  average daily gain, also showed quadratic behavior. In concentrated supplements provided in the amount of 10 g kg‑1 body weight, the total replacement of corn by crude glycerin reduces supplement and digestible organic matter intake, besides the performance of grazing beef cattle.O objetivo deste trabalho foi avaliar o efeito da substituição do milho pela glicerina bruta (GB) sobre os parâmetros nutricionais e o desempenho de bovinos de corte em pastagem de Urochloa brizantha 'Marandu', no período seco. Para a avaliação dos parâmetros ruminais, foram utilizados cinco bovinos da raça Nelore não fistulados, com peso corporal (PC) inicial de 331,7±29,6 kg, distribuídos em delineamento em quadrado latino 5x5. Para a avaliação do desempenho, foram utilizados 30 bovinos, com PC médio de 312,4±23,3 kg, distribuídos em delineamento inteiramente casualizado. Avaliaram-se suplementos concentrados (20% de proteína bruta) com 0, 33, 66 e 100% de GB em substituição ao milho, fornecidos na quantidade de 4,0 kg por animal por dia. Os consumos de matéria seca (MS) de suplemento, total e de pasto, bem como o de matéria orgânica (MO) digestível, apresentaram comportamento quadrático frente aos níveis de substituição. As digestibilidades aparentes de MS, MO, fibra em detergente neutro e MO digerida, bem como o ganho médio diário, também apresentaram comportamento quadrático. Em suplementos concentrados fornecidos na quantidade de 10 g kg‑1 de peso corporal, a substituição total do milho pela glicerina bruta reduz o consumo de suplemento e de matéria orgânica digerida, além do desempenho de bovinos de corte em pastejo

Analytical Solutions of Open String Field Theory

In this work we review Schnabl's construction of the tachyon vacuum solution to bosonic covariant open string field theory and the results that followed. We survey the state of the art of string field theory research preceding this construction focusing on Sen's conjectures and the results obtained using level truncation methods. The tachyon vacuum solution can be described in various ways. We describe its geometric representation using wedge states, its formal algebraic representation as a pure-gauge solution and its oscillator representation. We also describe the analytical proofs of some of Sen's conjectures for this solution. The tools used in the context of the vacuum solution can be adapted to the construction of other solutions, namely various marginal deformations. We present some of the approaches used in the construction of these solutions. The generalization of these ideas to open superstring field theory is explained in detail. We start from the exposition of the problems one faces in the construction of superstring field theory. We then present the cubic and the non-polynomial versions of superstring field theory and discuss a proposal suggesting their classical equivalence. Finally, the bosonic solutions are generalized to this case. In particular, we focus on the (somewhat surprising) generalization of the tachyon solution to the case of a theory with no tachyons.Comment: Invited review for Physics Reports. v1: 106 p., 8 fig. v2: 108 p., minor changes. v3: 117 p., 9 fig., presentation modified and expanded in several places, typos corrected, ref. added and updated. v4: Published version. 125 p., 10 fig., further modifications of the presentation, ref. added and update