Release of captive-raised Eastern hellbenders (Cryptobranchus alleganiensis) to test the success of a chytrid vaccine and new cage design

Researchers and managers commonly apply captive-raising and reintroductions of animals to offset losses due to worldwide amphibian declines. Recent declines in the Eastern hellbender (Cryptobranchus alleganiensis alleganiensis) have resulted in several reintroductions that have had little success. There is evidence that chytridiomycosis (chytrid), a disease caused by the fungus Batrachochytrium dendrobatidis (Bd), may negatively affect hellbenders post-release. Further, excessive post-release movement may result in movement away from suitable habitat and increased risk of predation which can have negative effects on the survival of released hellbenders. Caging captive-raised animals can be effective for limiting excessive post-release movement. This study tested a new chytrid vaccine and release method involving a new temporary cage design. Twenty captive-raised hellbenders were released into a stream in the Allegheny River drainage in June 2017. Half of these hellbenders were vaccinated. Five vaccinated and five unvaccinated hellbenders were released into cages that were removed in September 2017. The other half (five vaccinated, five unvaccinated) were released directly into the stream. Hellbenders were located daily using radio telemetry and tested for Bd weekly for the remainder of the study period. Overall, the 118-day study resulted in 30% survival. The vaccine was unsuccessful; all hellbenders tested positive for Bd at some point during the summer. After cage removal, caged hellbenders moved as much as uncaged, but this caging method may have contributed to greater survival for hellbenders in the caged treatment group. These findings suggest that chytridiomycosis is a major issue for survival of head-started hellbenders in NYS, and that caging during release may require further investigation

Venus cusp observations during 1969 - Synopsis of results

Venus cusp observations during 196

Space shuttle electromagnetic environment experiment. Phase A: Definition study

Methods for carrying out measurements of earth electromagnetic environment using the space shuttle as a measurement system platform are herein reported. The goal is to provide means for mapping intentional and nonintentional emitters on earth in the frequency range 0.4 to 40 GHz. A survey was made of known emitters using available data from national and international regulatory agencies, and from industry sources. The spatial distribution of sources, power levels, frequencies, degree of frequency re-use, etc., found in the survey, are here presented. A concept is developed for scanning the earth using a directive antenna whose beam is made to rotate at a fixed angle relative to the nadir; the illuminated area swept by the beam is of the form of cycloidal annulus over a sphere. During the beam's sojourn over a point, the receiver sweeps in frequency over ranges in the order of octave width using sweeping filter bandwidths sufficient to give stable readings

Space shuttle electromagnetic environment experiment. Phase A: Definition study

A program is discussed which develops a concept for measuring the electromagnetic environment on earth with equipment on board an orbiting space shuttle. Earlier work on spaceborne measuring experiments is reviewed, and emissions to be expected are estimated using, in part, previously gathered data. General relations among system parameters are presented, followed by a proposal on spatial and frequency scanning concepts. The methods proposed include a nadir looking measurement with small lateral scan and a circularly scanned measurement looking tangent to the earth's surface at the horizon. Antenna requirements are given, assuming frequency coverage from 400 MHz to 40 GHz. For the low frequency range, 400-1000 MHz, a processed, thinned array is proposed which will be more fully analyzed in the next phase of the program. Preliminary hardware and data processing requirements are presented

Asymptotic information leakage under one-try attacks

We study the asymptotic behaviour of (a) information leakage and (b) adversary’s error probability in information hiding systems modelled as noisy channels. Specifically, we assume the attacker can make a single guess after observing n independent executions of the system, throughout which the secret information is kept fixed. We show that the asymptotic behaviour of quantities (a) and (b) can be determined in a simple way from the channel matrix. Moreover, simple and tight bounds on them as functions of n show that the convergence is exponential. We also discuss feasible methods to evaluate the rate of convergence. Our results cover both the Bayesian case, where a prior probability distribution on the secrets is assumed known to the attacker, and the maximum-likelihood case, where the attacker does not know such distribution. In the Bayesian case, we identify the distributions that maximize the leakage. We consider both the min-entropy setting studied by Smith and the additive form recently proposed by Braun et al., and show the two forms do agree asymptotically. Next, we extend these results to a more sophisticated eavesdropping scenario, where the attacker can perform a (noisy) observation at each state of the computation and the systems are modelled as hidden Markov models

Regulatory and institutional issues for development of remedial action strategies at ORNL

This paper discusses a number of unresolved regulatory and institutional issues of fundamental importance to the development of strategies for cleanup of sites contaminated by the radioactive materials at Oak Ridge National Laboratory. These issues include the development of criteria for limiting radiation exposures of the public from remedial action sites, the time period to be assumed for active institutional controls over contaminated sites and the location at which such controls will be maintained, and the applicability of current standards for radioactivity in drinking water to surface waters and ground waters on the Oak Ridge Reservation. Proposals for resolution of these issues emphasize the need to protect public health, but in a cost-effective manner. 21 refs

Context for performance assessment

In developing its recommendations on performance assessment for disposal of low-level radioactive waste, Scientific committee 87-3 of the National Council on Radiation Protection and Measurements (NCRP) has considered a number of topics that provide a context for the development of suitable approaches to performance assessment. This paper summarizes the Committee` discussions on these topics, including (1) the definition of low-level waste and its sources and properties, as they affect the variety of wastes that must be considered, (2) fundamental objectives and principles of radioactive waste disposal and their application to low-level waste, (3) current performance objectives for low-level waste disposal in the US, with particular emphasis on such unresolved issues of importance to performance assessment as the time frame for compliance, requirements for protection of groundwater and surface water, inclusion of doses from radon, demonstrating compliance with fixed performance objectives using highly uncertain model projections, and application of the principle that releases to the environment should be maintained as low as reasonably achievable (ALARA), (4) the role of active and passive institutional controls over disposal sites, (5) the role of the inadvertent human intruder in low-level waste disposal, (6) model validation and confidence in model outcomes, and (7) the concept of reasonable assurance of compliance

Quantitative information flow, with a view

We put forward a general model intended for assessment of system security against passive eavesdroppers, both quantitatively ( how much information is leaked) and qualitatively ( what properties are leaked). To this purpose, we extend information hiding systems ( ihs ), a model where the secret-observable relation is represented as a noisy channel, with views : basically, partitions of the state-space. Given a view W and n independent observations of the system, one is interested in the probability that a Bayesian adversary wrongly predicts the class of W the underlying secret belongs to. We offer results that allow one to easily characterise the behaviour of this error probability as a function of the number of observations, in terms of the channel matrices defining the ihs and the view W . In particular, we provide expressions for the limit value as n → ∞, show by tight bounds that convergence is exponential, and also characterise the rate of convergence to predefined error thresholds. We then show a few instances of statistical attacks that can be assessed by a direct application of our model: attacks against modular exponentiation that exploit timing leaks, against anonymity in mix-nets and against privacy in sparse datasets