62,045 research outputs found

    Sharks - The State of the Science

    Get PDF
    The biological characteristics of sharks make them particularly vulnerable to overfishing. They grow slowly, become sexually mature relatively late and produce few offspring. This vulnerability is reflected in the large number of shark species that are considered to be threatened or endangered. This review of the current scientific literature on the number of sharks killed per year, the causes of this mortality, the status of shark species worldwide and the impact on ecosystems after large predators are removed provides key points

    Measurement of the Degree of Cellulose Degradation Caused by Fungi

    Get PDF
    The objective of this thesis is to obtain a method for determining the degree of cellulose degradation, caused by fungal attack, using testing methods commen to the paper industry rather than complex biochemical testing procedures

    Antidepressant-related deaths.

    No full text

    Workpiece positioning vise

    Get PDF
    A pair of jaw assemblies simultaneously driven in opposed reciprocation by a single shaft has oppositely threaded sections to automatically center delicate or brittle workpieces such as lithium fluoride crystal beneath the blade of a crystal cleaving machine. Both jaw assemblies are suspended above the vise bed by a pair of parallel guide shafts attached to the vise bed. Linear rolling bearings, fitted around the guide shafts and firmly held by opposite ends of the jaw assemblies, provide rolling friction between the guide shafts and the jaw assemblies. A belleville washer at one end of the drive shaft and thrust bearings at both drive shaft ends hold the shaft in compression between the vise bed, thereby preventing wobble of the jaw assemblies due to wear between the shaft and vise bed

    Distribution of red deepsea crab (Chaceon quinquedens) by size and sex in the Gulf of Mexico

    Get PDF
    The red deepsea crab (Chaceon quinquedens (Smith, 1879)) has supported a commercial fishery off the coast of New England since the 1970s (Wigley et al., 1975) and has had annual harvests from 400 metric tons (t) (1996) to 4000 t (2001) (NEFMC, 2002). In 2002, a fishery management plan for the northeast fishery on the Atlantic coast was implemented and total allowable catch was reduced to approximately 2500 t (NEFMC, 2002). Although there are management plans for the golden crab (C. fenneri) and the red deep sea crab for Atlantic coast regions, there is no fishery management plan for red deepsea crabs in the Gulf of Mexico. Successful management for sustainable harvests should be based on a knowledge of the life history of the species, but C. quinquedens has been a difficult species for which to obtain life history and abundance information because of its deep distribution
    • ā€¦
    corecore