Targeted “Hotspot” Removal of Derelict Blue Crab Traps (VA, MD)

In the winter of 2019/2020, five commercial watermen spent a cumulative total of 120 removal days on the water and collected 971 derelict blue crab traps which contained 985 blue crabs, 239 fish (oyster toad fish, black sea bass, flounder, pig fish, striped bass, speckled trout, perch, butterfish), 31 diamond back terrapin (a listed “species of concern”), and one duck. A majority of the traps removed were metal as opposed to vinyl coated (83% and 17%, respectively). Bycatch was present in 43% (346) of metal traps and 44% (72) of vinyl coated traps removed. On average, the instantaneous capture rates were similar for both trap types with an average of 1.0 crab captured per trap and 0.25 fish captured per trap. In addition, 10 abandoned eel traps were removed which contained 2 blue crabs, 3 fish, and 1eel

The D0 Run IIb Luminosity Measurement

An assessment of the recorded integrated luminosity is presented for data collected with the D0 detector at the Fermilab Tevatron Collider from June 2006 to September 2011 (Run IIb). In addition, a measurement of the effective cross section for inelastic interactions, also referred to as the luminosity constant, is reported. This measurement incorporates new features that lead to a substantial improvement in the precision of the result. A luminosity constant of \sigma_{LM} = 48.3\pm1.9\pm0.6 mb is obtained, where the first uncertainty is due to the accuracy of the inelastic cross section used by both CDF and D0, and the second uncertainty is due to D0 sources. The recorded luminosity for the highest E_T jet trigger is L_rec = 9.2 \pm 0.4 fb^{-1}, with a relative uncertainty of 4.3%.Comment: 20 pages, 23 figure

Architecture of a Silicon Strip Beam Position Monitor

A collaboration between Fermilab and the Institute for High Energy Physics (IHEP), Beijing, has developed a beam position monitor for the IHEP test beam facility. This telescope is based on 5 stations of silicon strip detectors having a pitch of 60 microns. The total active area of each layer of the detector is about 12x10 cm2. Readout of the strips is provided through the use of VA1` ASICs mounted on custom hybrid printed circuit boards and interfaced to Adapter Cards via copper-over-kapton flexible circuits. The Adapter Cards amplify and level-shift the signal for input to the Fermilab CAPTAN data acquisition nodes for data readout and channel configuration. These nodes deliver readout and temperature data from triggered events to an analysis computer over gigabit Ethernet links.Comment: Submitted to TWEPP 201

Ariel - Volume 10 Number 1

Executive Editors Madalyn Schaefgen David Reich Business Manager David Reich News Editors Medical College Edward Zurad CAHS John Guardiani World Mark Zwanger Features Editors Meg Trexler Jim O\u27Brien Editorials Editor Jeffrey Banyas Photography and Sports Editor Stuart Singer Commons Editor Brenda Peterso

Microsecond delays on non-real time operating systems

We have developed microsecond timing and profiling software that runs on standard Windows and Linux based operating systems. This software is orders of magnitudes better than most of the standard native functions in wide use. Our software libraries calibrate RDTSC in microseconds or seconds to provide two different types of delays: a ''Guaranteed Minimum'' and a precision ''Long Delay'', which releases to the kernel. Both return profiling information of the actual delay

Derelict Blue Crab Trap Impacts on Marine Fisheries in the Lower York River, Virginia

In Virginia, an examination of existing derelict trap data retrieved from Chesapeake Bay Multispecies Monitoring and Assessment Program (ChesMMAP) trawl surveys shows the potential effect of derelict traps on fish communities in Virginia waters (Bonzek and Latour 2005). Since 2002, ChesMMAP has attempted to sample 90 stations in the mainstem Chesapeake Bay ranging from the southern edge of the Susquehanna Flats to the Bay mouth in all depths to a minimum of 10 feet during each cruise. There are approximately 4-5 cruises per year and a large mesh bottom trawl is used to capture adult fish of a variety of species. During this sampling time frame (2002-2005), when derelict traps were inadvertently dredged up with the trawl, observations on fish and shellfish species trapped within were made

Ecological and Economic Effects of Derelict Fishing Gear in the Chesapeake Bay 2015/2016 Final Assessment Report

Derelict fishing gear represents a major challenge to marine resource management: whether through deliberate abandonment or through accidental loss, derelict traps in particular have significant negative effects both economic (e.g., reduced fishery harvest from ghost fishing and gear competition that leads to the reduced efficiency of active gear) and ecological (e.g., degraded habitats and marine food webs and crab and bycatch mortality). Throughout the Chesapeake Bay, commercial harvest of hard-shelled blue crabs is a major fishing activity: every year sees the deployment of several hundred thousand blue crab traps (known locally as crab “pots”) across the Bay, of which an estimated 12-20% are lost each year. This report focuses on these derelict crab pots, drawing on many direct or remote observations and other data to quantify their abundance and spatial distribution across the Chesapeake Bay, and their resulting ecological and economic effects

The Layer 0 Inner Silicon Detector of the D0 Experiment

This paper describes the design, fabrication, installation and performance of the new inner layer called Layer 0 (L0) that was inserted in the existing Run IIa Silicon Micro-Strip Tracker (SMT) of the D0 experiment at the Fermilab Tevatron collider. L0 provides tracking information from two layers of sensors, which are mounted with center lines at a radial distance of 16.1 mm and 17.6 mm respectively from the beam axis. The sensors and readout electronics are mounted on a specially designed and fabricated carbon fiber structure that includes cooling for sensor and readout electronics. The structure has a thin polyimide circuit bonded to it so that the circuit couples electrically to the carbon fiber allowing the support structure to be used both for detector grounding and a low impedance connection between the remotely mounted hybrids and the sensors.Comment: 28 pages, 9 figure