Diurnal and nocturnal temperatures for Atlantic salmon postsmolts (Salmo salar L.) during their early marine life

Data storage tags (DSTs) were applied to Atlantic salmon (Salmo salar L.) smolts during their seaward migration in the spring of 2002 at a fish counting fence on Campbellton River, Newfoundland. Our objectives were to discover whether or not salmon smolts could carry DSTs and survive, whether or not useful data on thermal habitat could be obtained and interpreted, and whether or not salmon smolts moved vertically in the water column. Data were downloaded from 15 of the recovered tags and revealed the hourly water temperatures experienced by the fish for periods of 3 to 71 days. The data on the DSTs were analyzed for temperature patterns in relation to migration behavior and diurnal movement of the fish. While in the sea, the DSTs recorded night temperatures of 12.5°C, which were higher than day temperatures of 11.6°C; the record from moored recorders, however, indicated that sea temperatures actually declined at night. It is hypothesized that posts-molts avoid avian predators during daylight hours by positioning themselves deeper in the water column and that they were pursuing prey during the deeper vertical descents or ascents noted during the periods of more rapid changes in temperature

The relationship between smolt and postsmolt growth for Atlantic salmon (Salmo salar) in the Gulf of St. Lawrence

The interaction of ocean climate and growth conditions during the postsmolt phase is emerging as the primary hypothesis to explain patterns of adult recruitment for individual stocks and stock complexes of Atlantic salmon (Salmo salar). Friedland et al. (1993) first reported that contrast in sea surface temperature (SST) conditions during spring appeared to be related to recruitment of the European stock complex. This hypothesis was further supported by the relationship between cohort specific patterns of recruitment for two index stocks and regional scale SST (Friedland et al., 1998). One of the index stocks, the North Esk of Scotland, was shown to have a pattern of postsmolt growth that was positively correlated with survival, indicating that growth during the postsmolt year controls survival and recruitment (Friedland et al., 2000). A similar scenario is emerging for the North American stock complex where contrast in ocean conditions during spring in the postsmolt migration corridors was associated with the recruitment pattern of the stock complex (Friedland et al., 2003a, 2003b). The accumulation of additional data on the postsmolt growth response of both stock complexes will contribute to a better understanding of the recruitment process in Atlantic salmon

A correspondence between solution-state dynamics of an individual protein and the sequence and conformational diversity of its family.

Conformational ensembles are increasingly recognized as a useful representation to describe fundamental relationships between protein structure, dynamics and function. Here we present an ensemble of ubiquitin in solution that is created by sampling conformational space without experimental information using "Backrub" motions inspired by alternative conformations observed in sub-Angstrom resolution crystal structures. Backrub-generated structures are then selected to produce an ensemble that optimizes agreement with nuclear magnetic resonance (NMR) Residual Dipolar Couplings (RDCs). Using this ensemble, we probe two proposed relationships between properties of protein ensembles: (i) a link between native-state dynamics and the conformational heterogeneity observed in crystal structures, and (ii) a relation between dynamics of an individual protein and the conformational variability explored by its natural family. We show that the Backrub motional mechanism can simultaneously explore protein native-state dynamics measured by RDCs, encompass the conformational variability present in ubiquitin complex structures and facilitate sampling of conformational and sequence variability matching those occurring in the ubiquitin protein family. Our results thus support an overall relation between protein dynamics and conformational changes enabling sequence changes in evolution. More practically, the presented method can be applied to improve protein design predictions by accounting for intrinsic native-state dynamics

Extra dimensions, orthopositronium decay, and stellar cooling

In a class of extra dimensional models with a warped metric and a single brane the photon can be localized on the brane by gravity only. An intriguing feature of these models is the possibility of the photon escaping into the extra dimensions. The search for this effect has motivated the present round of precision orthopositronium decay experiments. We point out that in this framework a photon in plasma should be metastable. We consider the astrophysical consequences of this observation, in particular, what it implies for the plasmon decay rate in globular cluster stars and for the core-collapse supernova cooling rate. The resulting bounds on the model parameter exceed the possible reach of orthopositronium experiments by many orders of magnitude.Comment: 13 pages, no figure

One Hour of Love

https://digitalcommons.library.umaine.edu/mmb-vp/3338/thumbnail.jp

Phase-locking transition in a chirped superconducting Josephson resonator

By coupling a harmonic oscillator to a quantum system it is possible to perform a dispersive measurement that is quantum non-demolition (QND), with minimal backaction. A non-linear oscillator has the advantage of measurement gain, but what is the backaction? Experiments on superconducting quantum bits (qubits) coupled to a non-linear Josephson oscillator have thus far utilized the switching of the oscillator near a dynamical bifurcation for sensitivity, and have demonstrated partial QND measurement. The detailed backaction associated with the switching process is complex, and may ultimately limit the degree to which such a measurement can be QND. Here we demonstrate a new dynamical effect in Josephson oscillators by which the bifurcation can be accessed without switching. When energized with a frequency chirped drive with an amplitude close to a sharp, phase-locking threshold, the oscillator evolves smoothly in one of two diverging trajectories - a pointer for the state of a qubit. The observed critical behavior agrees well with theory and suggests a new modality for quantum state measurement.Comment: 5 pages, 4 figure

The lived experiences of access to healthcare for people seeking and refused asylum

This research aims to explore the lived experiences of accessing healthcare among people currently seeking asylum and those who have had their claim for asylum refused, as well as the experiences of health service providers working with these communities. It examines the extent to which people are able to exercise their rights to access healthcare. It looks at the differences between those currently in the asylum system and those who have had their claim refused in England, Scotland and Wales. This report, and the partner report providing a review of evidence (https://www.equalityhumanrights.com/en/publication-download/access-healthcare-people-seeking-and-refused-asylum-great-britain-review), will be of interest to people who play an important role in delivering healthcare and related support services to people seeking or refused asylum. We have also made recommendations for what changes are needed (https://www.equalityhumanrights.com/en/publication-download/making-sure-people-seeking-and-refused-asylum-can-access-healthcare-what-needs) to make sure that people seeking and refused asylum have full enjoyment of their right to health. This report was produced in collaboration with Imperial College London and Doctors of the World UK

Transverse "resistance overshoot" in a Si/SiGe two-dimensional electron gas in the quantum Hall effect regime

We investigate the peculiarities of the "overshoot" phenomena in the transverse Hall resistance R_{xy} in Si/SiGe. Near the low magnetic field end of the quantum Hall effect plateaus, when the filling factor \nu approaches an integer i, R_{xy} overshoots the normal plateau value h/ie^2. However, if magnetic field B increases further, R_{xy} decreases to its normal value. It is shown that in the investigated sample n-Si/Si_{0.7}Ge_{0.3}, overshoots exist for almost all \nu. Existence of overshoot in R_{xy} observed in different materials and for different \nu, where splitting of the adjacent Landau bands has different character, hints at the common origin of this effect. Comparison of the experimental curves R_{xy}(\nu) for \nu = 3 and \nu = 5 with and without overshoot showed that this effect exist in the whole interval between plateaus, not only in the region where R_{xy} exceeds the normal plateau value.Comment: 3 pages, 5 EPS figure