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

What Makes a Problem GP-Hard? Analysis of a Tunably Difficult Problem in Genetic Programming

This paper addresses the issue of what makes a problem genetic programming (GP)-hard by considering the binomial-3 problem. In the process, we discuss the efficacy of the metaphor of an adaptive fitness landscape to explain what is GP-hard. We indicate that, at least for this problem, the metaphor is misleading.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45613/1/10710_2004_Article_335714.pd

Lipoprotein lipase is active as a monomer

Lipoprotein lipase (LPL), the enzyme that hydrolyzes triglycerides in plasma lipoproteins, is assumed to be active only as a homodimer. In support of this idea, several groups have reported that the size of LPL, as measured by density gradient ultracentrifugation, is ∼110 kDa, twice the size of LPL monomers (∼55 kDa). Of note, however, in those studies the LPL had been incubated with heparin, a polyanionic substance that binds and stabilizes LPL. Here we revisited the assumption that LPL is active only as a homodimer. When freshly secreted human LPL (or purified preparations of LPL) was subjected to density gradient ultracentrifugation (in the absence of heparin), LPL mass and activity peaks exhibited the size expected of monomers (near the 66-kDa albumin standard). GPIHBP1-bound LPL also exhibited the size expected for a monomer. In the presence of heparin, LPL size increased, overlapping with a 97.2-kDa standard. We also used density gradient ultracentrifugation to characterize the LPL within the high-salt and low-salt peaks from a heparin-Sepharose column. The catalytically active LPL within the high-salt peak exhibited the size of monomers, whereas most of the inactive LPL in the low-salt peak was at the bottom of the tube (in aggregates). Consistent with those findings, the LPL in the low-salt peak, but not that in the high-salt peak, was easily detectable with single mAb sandwich ELISAs, in which LPL is captured and detected with the same antibody. We conclude that catalytically active LPL can exist in a monomeric state

Equivariant Alexandrov Geometry and Orbifold Finiteness

Let a compact Lie group act isometrically on a non-collapsing sequence of compact Alexandrov spaces with fixed dimension and uniform lower curvature and upper diameter bounds. If the sequence of actions is equicontinuous and converges in the equivariant Gromov--Hausdorff topology, then the limit space is equivariantly homeomorphic to spaces in the tail of the sequence. As a consequence, the class of Riemannian orbifolds of dimension $n$ defined by a lower bound on the sectional curvature and the volume and an upper bound on the diameter has only finitely many members up to orbifold homeomorphism. Furthermore, any class of isospectral Riemannian orbifolds with a lower bound on the sectional curvature is finite up to orbifold homeomorphism.Comment: 25 pages, in v2 citation for Theorem 2.13 was corrected, in this version the material of arXiv:1401.0739 was incorporated. The combined article has been published in the Journal of Geometric Analysi

Kava, alcohol and tobacco consumption among Tongans with urbanization

The prevalence of kava (Piper methysticum), alcohol and tobacco consumption in Nuku'alofa (urban) and Foa (rural) are described. Current kava consumption was males 48% and females 1%. Prevalence was significantly higher among rural males. Current alcohol consumption was almost exclusive to the urban population and predominantly male, but only 2 (1%) rural males were current alcohol consumers. 169 (84.0%) of the rural males were irregularly or had ceased consuming alcohol. Tobacco consumption also showed a significant male predominance. There was a significantly higher total tobacco consumption in the urban population. Concordance of the three habits was evident among males, with 27 concordant positive (expected = 5.98) and 46 concordant negative (expected = 6.60). It appears that kava, a traditional Pacific beverage may have lost ground to alcohol as urban Tongans adopt a more cosmopolitan life style. Kava, if proved relatively harmless, may be promoted as a less unhealthy alternative to tobacco and alcohol.