Transient spatiotemporal chaos collapses into periodic and steady states in an electrically-coupled neural ring network

Chaotic behavior in a spatially extended system is often referred to as spatiotemporal chaos. The trajectories of a system as it evolves through state space are described by irregular spatial and temporal patterns. In mathematical biology, spatiotemporal chaos has been demonstrated in chemotaxis models (Painter & Hillen, 2011) predator-prey models (Sherratt, J. & Fowler, A., 1995) and the Hogdkin-Huxley neural model (Wang, Lu, & Chen, 2006). Transient chaos is a special case of chaotic dynamics in which the system dynamics collapses without external perturbation. Rather, collapse is an intrinsic property of the system. Here, we diff usively couple many spiking neurons into a ring network and fi nd that the network dynamics can collapse on to two diff erent species of attractor: the limit cycle and the steady-state solution

Fluorine toxicity studies Status progress report

Fluorine toxicity studies of effects from human inhalation and damage to animal kidney

Credit Risk and Bank Lending in the Czech Republic

This project undertakes an empirical analysis in credit risk modeling using a data sample representative of bank lending to the Czech corporate sector. A rating system is constructed using a proprietary database (Creditreform) that provides a solvency index for a large number of Czech firms. Several methods for the calibration and validation of a rating system are described and tested in practice. On the basis of a representative portfolio for Czech industries, systemic predictions of regulatory and economic capital are obtained and compared. The methodologies formulated by the latest Consultative Document of the NBCA (April 2003) and by the Credit Metrics and CreditRisk+ models are applied. The main contributions of this project can be briefly summarized as follows, (a) it shows in an applied manner that input data problems in credit risk modeling can be overcome, (b) it sheds light on regulatory issues that are gaining increasing relevance, and (c) it outlines the most important features of two credit risk models.Credit Risk, Economic Capital, Exchange Rate Exposure, Rating System.

The Economics of Manure Utilization: Model and Application

A model of manure utilization is developed and applied to four types of transportable manure. Model results highlight important response differences among manure types and generally illustrate the diseconomies of manure production. For example, as manure production increases, manure value decreases and excess phosphate applications increase, thereby increasing the potential for phosphorus runoff. Policy scenarios limiting the manure application rate reduce manure value and excess phosphate application. Increasing the ratio of land using manure increases manure value while reducing excess phosphate application. Buildup of soil nutrients reduces manure value, but either increases or decreases excess phosphate application depending on the scenario.linear programming, manure application, manure transportation, manure utilization, manure value, optimization, Farm Management,

IMPACT OF DOMESTIC FOOD PROGRAMS ON NUTRIENT INTAKE OF LOW-INCOME PERSONS IN THE UNITED STATES

Food Consumption/Nutrition/Food Safety, Food Security and Poverty,

Establishing optogenetic tools in the auditory system of the Mongolian Gerbil

The Mongolian Gerbil (Meriones unguiculatus) serves as a popular and widely used model organism for the human auditory system. Its hearing range largely overlaps with that of human’s and even extends below 1 kHz, frequencies very important for human hearing. Like humans, gerbils can localize sounds based on their interaural time difference (ITD) or interaural level difference (ILD) and also show perceptual suppression of the spatial source of reverberations (precedence effect). The auditory circuitries underlying the computation of ITDs and ILDs are very well described in the gerbil, although the exact mechanisms for the extraction of ITDs are still under debate. The contribution of the medial nucleus of the trapezoid body (MNTB) in tuning neurons sensitive to ITDs is still unclear. Similarly, the precedence effect is well known and thought to greatly facilitate listening in reverberant environments, yet the neural substrate of the precedence effect is still elusive. A circuitry that might subserve the precedence effect is hypothesized to be formed by the dorsal nucleus of the lateral lemniscus (DNLL) and the inferior colliculus (IC). However, a precise and reversible manipulation of the DNLL-IC circuitry or the ITD circuitry has not been possible due to the lack of technical means. With the advent of optogenetics, tools are becoming available that would allow to specifically activate and silence nuclei within both circuitries. Yet, transgenic lines or genetic tools are neither disposable nor established for the Mongolian Gerbil. Hence, in order to express optogenetic tools in the gerbil auditory brainstem and midbrain, a reliable and neuron specific gene delivery system needs to be established as a major prerequisite. Only when this important first step is taken, the actual optogenetical tools can be applied and tested. In this study, the first hurdle of gene delivery into the Mongolian Gerbil was successfully cleared by using recombinant adeno-associated viruses (rAAV) as vectors. Via the stereotactic injection of rAAVs into the DNLL, IC and MNTB, not only reliable and efficient transduction of neurons was achieved but also neuronal specific expression of transgenes was attained. As a second accomplishment, the channelrhodopsin mutant CatCH as well as the halorhodopsin NpHR3.0 were characterized in acute brain slices by performing whole cell patch-clamp recordings of transduced neurons. As a final step and proof of principle experiment, sound evoked neural responses in the DNLL and IC were successfully manipulated with light in vivo, as could be demonstrated by single cell extracellular recordings from anaesthetized animals. In sum, this study successfully adapted and established gene delivery and optogenetic tools in the auditory system of the Mongolian Gerbil. This represents a fully functional and highly versatile toolbox that not only paves the way to further elucidate the ITD as well as the DNLL-IC circuitry but is also applicable to other questions

Computer Intellectual Property Claims: Computer Software and Data Base Protection

The National Commission on New Technological Uses of Copyrighted Works has defined a set of subsidiary issues which have formed the basis for conducting its research and study activities. These issues include: (1) The manner in which computer software should be dealt with by copyright law; (2) How the copyright law should apply to automated data bases; (3) The copyright consequences of the input or output of a copyrighted work within a computer system; (4) The copyright status of “new works of authorship” created by the application or intervention of computer technology; and (5) How the law should deal with the long range implications of photocopying and other means of replication of copyrighted works. Keplinger explains the activities of the National Commission on New Technological Uses of Copyrighted Works, which was established in 1974 to recommend to the President and Congress changes in the copyright laws necessitated by advancing computer technology. Carefully striking a balance between the public interest and that of the creator of a work, the commission’s proposal precludes the unauthorized input, output, or storage of a work within the memory components of a computer system while specifically prohibiting copyright protection for ideas, procedures, principles, discoveries, or concepts