Property rights, collective action and technologies for natural resource management: a conceptual framework

Environmental management, Gender, Capacity,

Brans-Dicke DGP Brane Cosmology

We consider a five dimensional DGP-brane scenario endowed with a non-minimally coupled scalar field within the context of Brans-Dicke theory. This theory predicts that the mass appearing in the gravitational potential is modified by the addition of the mass of the effective intrinsic curvature on the brane. We also derive the effective four dimensional field equations on a 3+1 dimensional brane where the fifth dimension is assumed to have an orbifold symmetry. Finally, we discuss the cosmological implications of this setup, predicting an accelerated expanding universe with a value of the Brans-Dicke parameter $\omega$ consistent with values resulting from the solar system observations.Comment: 12 pages, 1 figure, to appear in JCA

The Mason Test: A Defense Against Sybil Attacks in Wireless Networks Without Trusted Authorities

Wireless networks are vulnerable to Sybil attacks, in which a malicious node poses as many identities in order to gain disproportionate influence. Many defenses based on spatial variability of wireless channels exist, but depend either on detailed, multi-tap channel estimation - something not exposed on commodity 802.11 devices - or valid RSSI observations from multiple trusted sources, e.g., corporate access points - something not directly available in ad hoc and delay-tolerant networks with potentially malicious neighbors. We extend these techniques to be practical for wireless ad hoc networks of commodity 802.11 devices. Specifically, we propose two efficient methods for separating the valid RSSI observations of behaving nodes from those falsified by malicious participants. Further, we note that prior signalprint methods are easily defeated by mobile attackers and develop an appropriate challenge-response defense. Finally, we present the Mason test, the first implementation of these techniques for ad hoc and delay-tolerant networks of commodity 802.11 devices. We illustrate its performance in several real-world scenarios

Impacts of agricultural research on poverty: findings of an integrated economic and social analysis

Agricultural research, Sustainable livelihoods, Agricultural growth, Gender, Agricultural technology,

Does the absence of cointegration explain the typical findings in long horizon regressions?

One of the stylized facts in financial and international economics is that of increasing predictability of variables such as exchange rates and stock returns at longer horizons. This fact is based upon applications of long horizon regressions, from which the typical findings are that the point estimates of the regression parameter, the associated t-statistic, and the regression R^2 all tend to increase as the horizon increases. Such long horizon regression analyses implicitly assume the existence of cointegration between the variables involved. In this paper, we investigate the consequences of dropping this assumption. In particular, we look upon the long horizon regression as a conditional error-correction model and interpret the test for long horizon predictability as a single equation test for cointegration. We derive the asymptotic distributions of the estimator of the regression parameter and its t-statistic for arbitrary horizons, under the null hypothesis of no cointegration. It is shown that these distributions provide an alternative explanation for at least part of the typical findings. Furthermore, the distributions are used to derive a Phillips-Perron type correction to the ordinary least-squares t-statistic in order to endow it with a stable size for given, arbitrary, horizon. A local asymptotic power analysis reveals that the power of long horizon regression tests does not increase with the horizon. Exchange rate data are used to demonstrate the empirical relevance of our theoretical results

Dimensional Effects on Densities of States and Interactions in Nanostructures

We consider electrons in the presence of interfaces with different effective electron mass, and electromagnetic fields in the presence of a high-permittivity interface in bulk material. The equations of motion for these dimensionally hybrid systems yield analytic expressions for Green’s functions and electromagnetic potentials that interpolate between the two-dimensional logarithmic potential at short distance, and the three-dimensional r−1 potential at large distance. This also yields results for electron densities of states which interpolate between the well-known two-dimensional and three-dimensional formulas. The transition length scales for interfaces of thickness L are found to be of order Lm/2m* for an interface in which electrons move with effective mass m*, and for a dielectric thin film with permittivity in a bulk of permittivity . We can easily test the merits of the formalism by comparing the calculated electromagnetic potential with the infinite series solutions from image charges. This confirms that the dimensionally hybrid models are excellent approximations for distances r ≳ L/2

Combining single view recognition and multiple view stereo for architectural scenes

©2001 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.This paper describes a structure from motion and recognition paradigm for generating 3D models from 2D sets of images. In particular we consider the domain of architectural photographs. A model based approach is adopted with the architectural model built from a “Lego kit” of parameterised parts. The approach taken is different from traditional stereo or shape from X approaches in that identification of the parameterised components (such as windows, doors, buttresses etc) from one image is combined with parallax information in order to generate the 3D model. This model based approach has two main benefits: first, it allows the inference of shape and texture where the evidence from the images is weak; and second, it recovers not only geometry and texture but also an interpretation of the model, which can be used for automatic enhancement techniques such as the application of reflective textures to windowsDick, A.R., Torr, P.H.S., Ruffle, S.J., Cipolla, R

The isolation from Saccharomyces cerevisiae of two antibacterial cationic proteins that inhibit malolactic bacteria

Substances with antibacterial activity were recovered from the extracellular medium and from the acidified cell extract of Saccharomyces cerevisiae R107 by binding onto a cation exchanger. The fraction eluted with NaOH contained two different antibacterial factors, one with the characteristics of lysozyme, the other apparently a small protein with a similar high pI.Die Isolierung von zwei bakteriziden, kationischen Proteinen aus Saccharomyces cerevisiae, die Bakterien des Säureabbaus hemmenSubstanzen mit bakterizider Wirkung wurden sowohl aus dem Kultursubstrat als auch aus angesäuertem Zellextrakt von Saccharomyces cerevisiae Rl07 mit Hilfe von Kationenaustauscher isoliert. Die mit NaOH eluierte Fraktion enthielt zwei unterschiedliche bakterizide Substanzen, eine mit Lysozymeigenschaften, die andere, ein kleines Protein, mit ähnlich hohem isoelektrischen Punkt

Adalimumab in the treatment of pediatric patients with chronic noninfectious anterior uveitis

Introduction: Adalimumab is established as an effective treatment for pediatric noninfectious uveitis refractory to methotrexate. However current use of the medication is empiric, according to fixed-dosing regimens and a significant proportion of patients will be nonresponsive or suboptimally responsive to adalimumab. Areas covered: There remains considerable scope to improve outcomes through tailoring treatment according to individual patient responsiveness. Monitoring of anti-drug antibodies and serum drug trough levels may assist in predicting which patients are likely to have a poor response to adalimumab and enable tailoring of regimens to individual patients. Expert opinion: We propose use of these biomarkers to individualize therapy in suboptimally responding patients, and present an algorithm of treatment escalation for pediatric noninfectious uveitis