A Bioeconomic Analysis of the Northwestern Hawaiian Islands Lobster Fishery

Several surplus production-based bioeconomic models are applied to the Northwestern Hawaiian Islands (NWHI) commercial lobster fishery. The model which best explains the biological dynamics of the fishery is a modification of the Fox model developed by the authors. Economic costs are applied within a number of conceptual frameworks to develop the first integrated bioeconomic model of the fishery. In another development, the opportunity cost of labor based on crew share at the open access equilibrium level of fishing effort is used instead of proxy wage levels. Given the costs incurred, the fishery appears to be self-regulating in terms of long-term fishing effort for maximum sustainable yield.biological production models, fisheries economics, fisheries management, spiny lobster, slipper lobster, Environmental Economics and Policy, Resource /Energy Economics and Policy,

Deconfined Fermions but Confined Coherence?

The cuprate superconductors and certain organic conductors exhibit transport which is qualitatively anisotropic, yet at the same time other properties of these materials strongly suggest the existence of a Fermi surface and low energy excitations with substantial free electron character. The former of these features is very difficult to account for if the material possesses three dimensional coherence, while the latter is inconsistent with a description based on a two dimensional fixed point. We therefore present a new proposal for these materials in which they are categorized by a fixed point at which transport in one direction is not renormalization group irrelevant, but is intrinsically incoherent, i.e. the incoherence is present in a pure system, at zero temperature. The defining property of such a state is that single electron coherence is confined to lower dimensional subspaces (planes or chains) so that it is impossible to observe interference effects between histories which involve electrons moving between these subspaces.Comment: 31 pages, REVTEX, 3 eps figures, epsf.tex macr

Inhomogeneous Dust Collapse in 5D Einstein-Gauss-Bonnet Gravity

We consider a Lemaitre - Tolman - Bondi type space-time in Einstein gravity with the Gauss-Bonnet combination of quadratic curvature terms, and present exact solution in closed form. It turns out that the presence of the coupling constant of the Gauss-Bonnet terms alpha > 0 completely changes the causal structure of the singularities from the analogous general relativistic case. The gravitational collapse of inhomogeneous dust in the five-dimensional Gauss-Bonnet extended Einstein equations leads to formation of a massive, but weak, timelike singularity which is forbidden in general relativity. Interestingly, this is a counterexample to three conjecture viz. cosmic censorship conjecture, hoop conjecture and Seifert's conjecture.Comment: 8 Latex Pages, 2 EPS figure

Non-spherical collapse of a two fluid star

We obtain the analogue of collapsing Vaidya-like solution to include both a null fluid and a string fluid, with a linear equation of state ($p_{\bot} = k \rho$), in non-spherical (plane symmetric and cylindrically symmetric) anti-de Sitter space-timess. It turns out that the non-spherical collapse of two fluid in anti-de Sitter space-times, in accordance with cosmic censorship, proceed to form black holes, i.e., on naked singularity ever forms, violating hoop conjecture.Comment: 7 pages, RevTeX 4, minor correction

How Do Schr\"odinger's Cats Die?

Recent experiments with superconducting qubits are motivated by the goal of fabricating a quantum computer, but at the same time they illuminate the more fundamental aspects of quantum mechanics. In this paper we analyze the physics of switching current measurements from the point of view of macroscopic quantum mechanics.Comment: 4 figures, 12 page

What is the impact of psychiatric decision units on mental health crisis care pathways? Protocol for an interrupted time series analysis with a synthetic control study

Background The UK mental health system is stretched to breaking point. Individuals presenting with mental health problems wait longer at the ED than those presenting with physical concerns and finding a bed when needed is difficult – 91% of psychiatric wards are operating at above the recommended occupancy rate. To address the pressure, a new type of facility – psychiatric decision units (also known as mental health decision units) – have been introduced in some areas. These are short-stay facilities, available upon referral, targeted to help individuals who may be able to avoid an inpatient admission or lengthy ED visit. To advance knowledge about the effectiveness of this service for this purpose, we will examine the effect of the service on the mental health crisis care pathway over a 4-year time period; the 2 years proceeding and following the introduction of the service. We use aggregate service level data of key indicators of the performance of this pathway. Methods Data from four mental health Trusts in England will be analysed using an interrupted time series (ITS) design with the primary outcomes of the rate of (i) ED psychiatric presentations and (ii) voluntary admissions to mental health wards. This will be supplemented with a synthetic control study with the same primary outcomes, in which a comparable control group is generated for each outcome using a donor pool of suitable National Health Service Trusts in England. The methods are well suited to an evaluation of an intervention at a service delivery level targeting population-level health outcome and the randomisation or ‘trialability’ of the intervention is limited. The synthetic control study controls for national trends over time, increasing our confidence in the results. The study has been designed and will be carried out with the involvement of service users and carers. Discussion This will be the first formal evaluation of psychiatric decision units in England. The analysis will provide estimates of the effect of the decision units on a number of important service use indicators, providing much-needed information for those designing service pathways

Creating citizen-consumers? Public service reform and (un)willing selves

About the book: Postmodern theories heralded the "death of the subject", and thereby deeply contested our intuition that we are free and willing selves. In recent times, the (free) will has come under attack yet again. Findings from the neuro- and cognitive sciences claim the concept of will to be scientifically untenable, specifying that it is our brain rather than our 'self' which decides what we want to do. In spite of these challenges however, the willing self has come to take centre stage in our society: juridical and moral practices ascribing guilt, or the organization of everyday life attributing responsibilities, for instance, can hardly be understood without taking recourse to the willing subject. In this vein, the authors address topics such as the genealogy of the concept of willing selves, the discourse on agency in neuroscience and sociology, the political debate on volition within neoliberal and neoconservative regimes, approaches toward novel forms of relational responsibility as well as moral evaluations in conceptualizing autonomy

Budget feasible mechanisms on matroids

Motivated by many practical applications, in this paper we study budget feasible mechanisms where the goal is to procure independent sets from matroids. More specifically, we are given a matroid =(,) where each ground (indivisible) element is a selfish agent. The cost of each element (i.e., for selling the item or performing a service) is only known to the element itself. There is a buyer with a budget having additive valuations over the set of elements E. The goal is to design an incentive compatible (truthful) budget feasible mechanism which procures an independent set of the matroid under the given budget that yields the largest value possible to the buyer. Our result is a deterministic, polynomial-time, individually rational, truthful and budget feasible mechanism with 4-approximation to the optimal independent set. Then, we extend our mechanism to the setting of matroid intersections in which the goal is to procure common independent sets from multiple matroids. We show that, given a polynomial time deterministic blackbox that returns -approximation solutions to the matroid intersection problem, there exists a deterministic, polynomial time, individually rational, truthful and budget feasible mechanism with (3+1) -approximation to the optimal common independent set

River Clyde Environmental Change Network diatom analysis project final: report to SEPA

This report provides details of work performed on the SEPA contract to ENSIS Ltd. involving the preparation and analysis of historic (September 1994 – August 2010) Environmental Change Network diatom samples from the River Clyde at the Tidal Weir. Diatoms were collected from the site by SEPA, forwarded to ENSIS Ltd and prepared for analysis following protocols described in the United Kingdom Environmental Change Network’s “Protocols for Standard Measurements at Freshwater Sites” (Sykes et al., 1999). Samples were taken at the site at various times of year and a full list of those that have been received by ENSIS is provided in Appendix 1. For this project, in order to minimise any inter-seasonal variability in the time-series, Kate Arnold from SEPA selected a subset of 16 summer samples for analysis, all collected between late July and early September. Approximately 400 diatom valves were counted per sample by Gina Clarke using a light microscope with phase contrast at 1000x magnification. Count data were recorded on a spreadsheet and transferred to ENSIS where they have been added to the ECN diatom database and have also been provided to SEPA. The diatom count data was run through the DARLEQII program (Kelly et al, 2011) in order to generate Trophic Diatom Index (TDI), Ecological Quality Ratio (EQR) and status class values (high, good, moderate, poor, bad) for each sample. Alkalinity values for the calculations were provided by SEPA for all samples except the earliest three in the timeseries, for which the average from all samples was used. Both TDI3 and TDI4 scores were calculated for all samples and the scores reported here. Table 1 is taken from the DARLEQII user guide (Kelly et al, 2011) and describes the output fields provided in the results section for the site below. Electronic copies of the full DARLEQII program output have been provided to SEPA