Programming in logic without logic programming

In previous work, we proposed a logic-based framework in which computation is the execution of actions in an attempt to make reactive rules of the form if antecedent then consequent true in a canonical model of a logic program determined by an initial state, sequence of events, and the resulting sequence of subsequent states. In this model-theoretic semantics, reactive rules are the driving force, and logic programs play only a supporting role. In the canonical model, states, actions and other events are represented with timestamps. But in the operational semantics, for the sake of efficiency, timestamps are omitted and only the current state is maintained. State transitions are performed reactively by executing actions to make the consequents of rules true whenever the antecedents become true. This operational semantics is sound, but incomplete. It cannot make reactive rules true by preventing their antecedents from becoming true, or by proactively making their consequents true before their antecedents become true. In this paper, we characterize the notion of reactive model, and prove that the operational semantics can generate all and only such models. In order to focus on the main issues, we omit the logic programming component of the framework.Comment: Under consideration in Theory and Practice of Logic Programming (TPLP

Managing Intellectual Property to Foster Agricultural Development

Over the past decades, consideration of IPRs has become increasingly important in many areas of agricultural development, including foreign direct investment, technology transfer, trade, investment in innovation, access to genetic resources, and the protection of traditional knowledge. The widening role of IPRs in governing the ownership of—and access to—innovation, information, and knowledge makes them particularly critical in ensuring that developing countries benefit from the introduction of new technologies that could radically alter the welfare of the poor. Failing to improve IPR policies and practices to support the needs of developing countries will eliminate significant development opportunities. The discussion in this note moves away from policy prescriptions to focus on investments to improve how IPRs are used in practice in agricultural development. These investments must be seen as complementary to other investments in agricultural development. IPRs are woven into the context of innovation and R&D. They can enable entrepreneurship and allow the leveraging of private resources for resolving the problems of poverty. Conversely, IPRs issues can delay important scientific advancements, deter investment in products for the poor, and impose crippling transaction costs on organizations if the wrong tools are used or tools are badly applied. The central benefit of pursuing the investments outlined in this note is to build into the system a more robust capacity for strategic and flexible use of IPRs tailored to development goals

Intellectual Property Management Strategies to Accelerate the Development and Access of Vaccines and Diagnostics: Case Studies on Pandemic Influenza, Malaria and SARS

Achieving global access to vaccines, diagnostics, and pharmaceuticals remains a challenge. Throughout the developing world, intellectual property (IP) constraints complicate access to critically essential medical technologies and products. Vaccines for malaria and pandemic strains of influenza, as well as diagnostic and vaccine technologies for SARS, are not only relevant to global public health but are particularly critical to the needs of developing countries. A global access solution is urgently needed. This article offers a timely case‐by‐case analysis of preliminary patent landscape surveys and formulates options via patent pools and other forms of creative IP management to accelerate development and access. The analysis of the feasibility of patent pools reveals several impediments to patent pools: these include antitrust considerations, bargaining difficulties caused by asymmetric interests and asymmetric rights among IP holders (e.g. improvement vs. foundational patents), and the difficulties of securing financial support given the significant transaction costs associated with pools. Because of the above conceptual and operational hurdles, patent pools do not appear to be a feasible way to accelerate development. Other mechanisms, however, can ameliorate IP constraints. For example, a key IP constraint related to pandemic influenza vaccines R&D appears to have been resolved when Medimmune secured the assembly of all relevant reverse genetics IP and pledged broad access. Clearly, the landscape is complex and multidimensional. Licensing systems are not the only issue. Measures must also be taken to limit regulatory hurdles and enable the swift, legal production of pandemic influenza vaccines to meet the needs of developing countries. This is why a comprehensive analysis is so necessary. From a strictly legal perspective, IP systems work through the power to exclude. However, as this study’s exploration and formulation of creative licensing strategies reveals, it is also true that IP can be structured and managed to work through the “power to include.

Dynamical variety of shapes in financial multifractality

The concept of multifractality offers a powerful formal tool to filter out multitude of the most relevant characteristics of complex time series. The related studies thus far presented in the scientific literature typically limit themselves to evaluation of whether or not a time series is multifractal and width of the resulting singularity spectrum is considered a measure of the degree of complexity involved. However, the character of the complexity of time series generated by the natural processes usually appears much more intricate than such a bare statement can reflect. As an example, based on the long-term records of S&P500 and NASDAQ - the two world leading stock market indices - the present study shows that they indeed develop the multifractal features, but these features evolve through a variety of shapes, most often strongly asymmetric, whose changes typically are correlated with the historically most significant events experienced by the world economy. Relating at the same time the index multifractal singularity spectra to those of the component stocks that form this index reflects the varying degree of correlations involved among the stocks.Comment: 26 pages, 10 figure

A Survey of the Management and Development of Captive African Elephant (\u3cem\u3eLoxodonta africana\u3c/em\u3e) Calves: Birth to Three Months of Age

We used four surveys to collect information about the birth, physical growth, and behavioral development of 12 African elephant calves born in captivity. The management of the birth process and neonatal care involved a variety of standard procedures. All of the calves were born at night, between 7PM and 7AM. The calves showed a systematic progression in behavioral and physical development, attaining developmental milestones at least a quickly as calves in situ. This study emphasized birth-related events, changes in the ways that calves used their trunks, first instances of behaviors, and interactions of the calves with other, usually adult, elephants. Several behaviors, such as the dam covering her calf with hay and the calf sucking its own trunk, were common in the captive situation and have been observed in situ. Overall, the behaviors of the calves resembled those observed for African elephant calves in situ. These data should help in the management of African elephants under human care by providing systematic reference values for the birth and development of elephant calves