Comparison of life history parameters for landed and discarded fish captured off the southeastern United States

Commercial fisheries that are managed with minimum size limits protect small fish of all ages and may affect size-selective mortality by the differential removal of fast growing fish. This differential removal may decrease the average size at age, maturation, or sexual transition of the exploited population. When fishery-independent data are not available, a comparison of life history parameters of landed with those of discarded fish (by regulation) will indicate if differential mortality is occurring with the capture of young but large fish (fast growing phenotypes). Indications of this differential size-selective mortality would include the following: the discarded portion of the target fish would have similar age ranges but smaller sizes at age, maturation, and sexual transition as that of landed fish. We examined three species with minimum size limits but different exploitation histories. The known heavily exploited species (Rhomboplites aurorubens [vermilion snapper] and Pagrus pagrus [red porgy]) show signs of this differential mortality. Their landed catch includes many young, large fish, whereas discarded fish had a similar age range and mean ages but smaller sizes at age than the landed fish. The unknown exploited species, Mycteroperca phenax (scamp), showed no signs of differential mortality due to size-selective fishing. Landed catch consisted of old, large fish and discarded scamp had little overlap in age ranges, had significantly different mean ages, and only small differences in size at age when compared to comparable data for landed fish

Tonguefishes

The South Carolina Department of Natural Resources published guides to many threatened animals living in the state. This guide gives information about Tonguefishes, including description, status, habitat, conservation challenges & recommendations, and measures of success

Nonlinear quantum error correction

We introduce a theory of quantum error correction (QEC) for a subclass of states within a larger Hilbert space. In the standard theory of QEC, the set of all encoded states is formed by an arbitrary linear combination of the codewords. However, this can be more general than required for a given quantum protocol which may only traverse a subclass of states within the Hilbert space. Here we propose the concept of nonlinear QEC (NLQEC), where the encoded states are not necessarily a linear combination of codewords. We introduce a sufficiency criterion for NLQEC with respect to the subclass of states. The new criterion gives a more relaxed condition for the formation of a QEC code, such that under the assumption that the states are within the subclass of states, the errors are correctable. This allows us, for instance, to effectively circumvent the no-go theorems regarding optical QEC for Gaussian states and channels, for which we present explicit examples

Circuit-based PSI for Covid-19 Risk Scoring

—Many solutions have been proposed to improve manual contact tracing for infectious diseases through automation. Privacy is crucial for the deployment of such a system as it greatly influences adoption. Approaches for digital contact tracing like Google Apple Exposure Notification (GAEN) protect the privacy of users by decentralizing risk scoring. But GAEN leaks information about diagnosed users as ephemeral pseudonyms are broadcast to everyone. To combat deanonymisation based on the time of encounter while providing extensive risk scoring functionality we propose to use a private set intersection (PSI) protocol based on garbled circuits. Using oblivious programmable pseudo random functions PSI (PPRF-PSI) , we implement our solution CERTAIN which leaks no information to querying users other than one risk score for each of the last 14 days representing their risk of infection. We implement payload inclusion for OPPRF-PSI and evaluate the efficiency and performance of different risk scoring mechanisms on an Android devic

Influence of soak time and fish accumulation on catches of reef fishes in a multispecies trap survey

Catch rates from fishery-independent surveys often are assumed to vary in proportion to the actual abundance of a population, but this approach assumes that the catchability coefficient (q) is constant. When fish accumulate in a gear, the rate at which the gear catches fish can decline, and, as a result, catch asymptotes and q declines with longer fishing times. We used data from long-term trap surveys (1990–2011) in the southeastern U.S. Atlantic to determine whether traps saturated for 8 reef fish species because of the amount of time traps soaked or the level of fish accumulation (the total number of individuals of all fish species caught in a trap). We used a delta-generalized-additive model to relate the catch of each species to a variety of predictor variables to determine how catch was influenced by soak time and fish accumulation after accounting for variability in catch due to the other predictor variables in the model. We found evidence of trap saturation for all 8 reef fish species examined. Traps became saturated for most species across the range of soak times examined, but trap saturation occurred for 3 fish species because of fish accumulation levels in the trap. Our results indicate that, to infer relative abundance levels from catch data, future studies should standardize catch or catch rates with nonlinear regression models that incorporate soak time, fish accumulation, and any other predictor variable that may ultimately influence catch. Determination of the exact mechanisms that cause trap saturation is a critical need for accurate stock assessment, and our results indicate that these mechanisms may vary considerably among species

Voltage-Driven Conformational Switching with Distinct Raman Signature in a Single-Molecule Junction

Precisely controlling well-defined, stable single-molecule junctions represents a pillar of single-molecule electronics. Early attempts to establish computing with molecular switching arrays were partly challenged by limitations in the direct chemical characterization of metalâEuro"moleculeâEuro"metal junctions. While cryogenic scanning probe studies have advanced the mechanistic understanding of current- and voltage-induced conformational switching, metalâEuro"moleculeâEuro"metal conformations are still largely inferred from indirect evidence. Hence, the development of robust, chemically sensitive techniques is instrumental for advancement in the field. Here we probe the conformation of a two-state molecular switch with vibrational spectroscopy, while simultaneously operating it by means of the applied voltage. Our study emphasizes measurements of single-molecule Raman spectra in a room-temperature stable single-molecule switch presenting a signal modulation of nearly 2 orders of magnitude

A flexible Diversity Workbench tool to publish biodiversity data from SQL database networks through platforms like GFBio

The Diversity Workbench (DWB, www.diversityworkbench.net) is a suite of MS SQL databases and data processing tools designed for the management of research data in biology, ecology and geosciences. The software apart from the underlying DBMS is open source. The complete software package is freely available. The DWB with ten data domain-specific databases, one generic database and some independent data processing tools is the result of 20 years software development. The DWB is suitable for single researchers, research groups of any size but also appropriate to set up networks for long-term data repositories and data centers. To operate automated transfer of bio- and geodiversity data for publication from those in-house networks, a new DWB tool was implemented. The core functions include the filtering and transformation of data and metadata from selected in-house data collections stored in productive master SQL databases. The tool is designed for use by database administrators and scientific data curators. It fulfils three major steps for each single data collection: • term, taxa and metadata assignment with parallel data export and creation of a not publicly accessible first-level cache MS SQL database independent from the DWB master database network; unifying data from data domain-specific DWB source databases inside of a (institutional) firewall • re-organisation of data, filtering according later data package assignment and creation of a second-level publicly accessible PostgreSQL database • creation of a publicly accessible data package properly formatted for data harvesting tools of web portals and for data mapping and provision software like the BIOCASe Provider Software. With this DWB tool for guiding data publication some major challenges in bio- and geodiversity research are addressed: a) The data filtering, transformation and publication can be done periodically and is realized without data change and information loss in the linked in-house master databases which might be curated in the long-run. b) A data expert and data scientist is able to handle this transformation tool and organize data publication with minor involvement of a database administrator. c) The data packages are configured for publication according to the individual requests of data producers who often ask for anonymization of certain persons, intend to withhold single data units, set embargos and have to blur geographic coordinates. d) With the automated data transfer for publication, the tool guarantees a reproducible path from the original source to the presentation on a platform. The data centers SMNS and SNSB are using the tool to guide their data publication through the GBIF global biodiversity data network (https://www.gbif.org/) and through the GFBio platform (https://www.gfbio.org/). Furthermore, it is used to create specifically formatted, publicly accessible cache databases with filtered and aggregated content for thematically focused information portals like the Botanischer Informationsknoten Bayern (http://daten.bayernflora.de/de/index.php). Summarizing, the new DWB tool is able to support a wide range of data transfer and transformation tasks for data publication from DWB networks. It is included in the published software versions of DiversityCollection and described in its manual. Future planning includes the extension of the tool to involve the data filtering and transformation from DiversityDescriptions as a generic DWB source database. KEYWORDS: automated data transfer, biodiversity data, data filtering, data publication, GFBio data center