Volunteer Angling and Technology-Based Solutions Provide the First Estimate of Sea Lice Infections for Wild Coastal Cutthroat Trout (Oncorhynchus Clarkii Clarkii)

Anadromous Coastal Cutthroat Trout Oncorhynchus clarkii clarkii are one of the least studied salmonids but are a highly prized target in sport fisheries in coastal waters of the Pacific Northwest. Despite an observed high prevalence of ectoparasite infections, described by sport anglers as "sea lice," there is a paucity of data available on the spatial and temporal occurrence of infections on Coastal Cutthroat Trout. We collaborated with the angling community through social media engagement and an online application to report ectoparasites observed on sport catch. In 2018, we received voluntary reports for 1,493 Cutthroat Trout and 416 salmon catch events in marine waters from the province of British Columbia and the states of Washington, Oregon, and California. These data demonstrated that the number of argulids and copepods per trout varied according to body size, capture month, and area. To evaluate accuracy of voluntary parasite counts, we compared results to parasite counts on cutthroat from sampling events conducted by trained biologists. For both voluntary angler reports and those of biologists, spring months had a lower prevalence of argulids and copepods, argulids were common on trout, but absent on salmon, and larger trout were associated with an increased number of argulid and copepod infections

Controlling chaos in spatially extended beam-plasma system by the continuous delayed feedback

In present paper we discuss the control of complex spatio-temporal dynamics in a {spatially extended} non-linear system (fluid model of Pierce diode) based on the concepts of controlling chaos in the systems with few degrees of freedom. A presented method is connected with stabilization of unstable homogeneous equilibrium state and the unstable spatio-temporal periodical states analogous to unstable periodic orbits of chaotic dynamics of the systems with few degrees of freedom. We show that this method is effective and allows to achieve desired regular dynamics chosen from a number of possible in the considered system.Comment: 12 pages, 12 figure

Evaluation of Visible Implant Elastomer Tags in Wild Coastal Cutthroat Trout in the Marine Environment

We evaluated the detectability of visible implant elastomer (VIE) tags in Coastal Cutthroat TroutOncorynchus clarkii clarkiiin the marine environment by comparing visually identified recaptures from VIE tags with known recaptures that were identified through genotype matching. A total of 89 individual Coastal Cutthroat Trout were marked in the lower jaw with colored VIE tags, sampled for genetics, and recaptured across 12 months in 2015. The rate of correspondence between the VIE tags and genetic matches was 92% (82/89) of the recaptured Coastal Cutthroat Trout in the nearshore marine environment. We found that red- and blue-colored VIE tags were detected at a higher rate (100%) than were yellow- and orange-colored tags (87.3% and 90.6%, respectively). In contrast, tag type (single or double), tag location (left or right), fish length (FL, mm), and time (days) since tagging had no effect on tag detectability during the study period. All of the tag colors were recovered for the maximum life of the study (up to 342 days). In all of the cases of nondetections (5/89), the tags were not identified upon initial recapture or subsequent capture events, suggesting that they were lost or not visible immediately upon insertion in the field-as opposed to being unidentified due to the degradation of tag detectability over time. The results of this study suggest that VIE tags have the potential to be detectable in juvenile and adult Coastal Cutthroat Trout for at least 12 months after insertion, with blue and red performing the best. Additional monitoring extending beyond 12 months after tagging would be necessary to identify the maximum life of VIE tags

Growth and condition of juvenile coho salmon Oncorhynchus kisutch relate positively to species richness of trophically transmitted parasites

The aims of this study were first, to test the hypothesis that metrics of fish growth and condition relate positively to parasite species richness (S[subscript R]) in a salmonid host; second, to identify whether S[subscript R] differs as a function of host origin; third, to identify whether acquisition of parasites through marine v. freshwater trophic interactions was related to growth and condition of juvenile salmonids. To evaluate these questions, species diversity of trophically transmitted parasites in juvenile coho salmon Oncorhynchus kisutch collected off the coast of the Oregon and Washington states, U.S.A. in June 2002 and 2004 were analysed. Fish infected with three or more parasite species scored highest in metrics of growth and condition. Fish originating from the Columbia River basin had lower SR than those from the Oregon coast, Washington coast and Puget Sound, WA. Parasites obtained through freshwater or marine trophic interactions were equally important in the relationship between SR and ocean growth and condition of juvenile O. kisutch salmon.This is the publisher’s final pdf. The article is copyrighted by the Fisheries Society of the British Isles and published by John Wiley & Sons Ltd. It can be found at: http://onlinelibrary.wiley.com/journal/10.1111/%28ISSN%291095-8649

A fractal set from the binary reflected Gray code

The permutation associated with the decimal expression of the binary reflected Gray code with N bits is considered. Its cycle structure is studied. Considered as a set of points, its self-similarity is pointed out. As a fractal, it is shown to be the attractor of an IFS. For large values of N the set is examined from the point of view of time series analysis

Inkjet-based biopatterning of bone morphogenetic protein-2 to spatially control calvarial bone formation

The purpose of this study was to demonstrate spatial control of osteoblast differentiation in vitro and bone formation in vivo using inkjet bioprinting technology and to create three-dimensional persistent bio-ink patterns of bone morphogenetic protein-2 (BMP-2) and its modifiers immobilized within microporous scaffolds. Semicircular patterns of BMP-2 were printed within circular DermaMatrix™ human allograft scaffold constructs. The contralateral halves of the constructs were unprinted or printed with BMP-2 modifiers, including the BMP-2 inhibitor, noggin. Printed bio-ink pattern retention was validated using fluorescent or 125I-labeled bio-inks. Mouse C2C12 progenitor cells cultured on patterned constructs differentiated in a dose-dependent fashion toward an osteoblastic fate in register to BMP-2 patterns. The fidelity of spatial restriction of osteoblastic differentiation at the boundary between neighboring BMP-2 and noggin patterns improved in comparison with patterns without noggin. Acellular DermaMatrix constructs similarly patterned with BMP-2 and noggin were then implanted into a mouse calvarial defect model. Patterns of bone formation in vivo were comparable with patterned responses of osteoblastic differentiation in vitro. These results demonstrate that three-dimensional biopatterning of a growth factor and growth factor modifier within a construct can direct cell differentiation in vitro and tissue formation in vivo in register to printed patterns. © 2010 Mary Ann Liebert, Inc

Kondo effect in quantum dots

We review mechanisms of low-temperature electronic transport through a quantum dot weakly coupled to two conducting leads. Transport in this case is dominated by electron-electron interaction. At temperatures moderately lower than the charging energy of the dot, the linear conductance is suppressed by the Coulomb blockade. Upon further lowering of the temperature, however, the conductance may start to increase again due to the Kondo effect. We concentrate on lateral quantum dot systems and discuss the conductance in a broad temperature range, which includes the Kondo regime