A generalized model for longitudinal short- and long-term mortality data for commercial fishery discards and recreational fishery catch-and-releases

Conservation concerns and new management policies such as the implementation of ecosystem-based approaches to fisheries management are motivating an increasing need for estimates of mortality associated with commercial fishery discards and released fish from recreational fisheries. Traditional containment studies and emerging techniques using electronic tags on fish released to the wild are producing longitudinal mortality-time data from which discard or release mortalities can be estimated, but where there may also be a need to account analytically for other sources of mortality. In this study, we present theoretical and empirical arguments for a parametric mixture-distribution model for discard mortality data. We show, analytically and using case studies for Atlantic cod (Gadus morhua), American plaice (Hippoglossoides platessoides), and winter skate (Leucoraja ocellata), how this model can easily be generalized to incorporate different characteristics of discard mortality data such as distinct capture, post-release and natural mortalities, and delayed mortality onset. In simulations over a range of conditions, the model provided reliable parameter estimates for cases involving both discard and natural mortality. These results support this modelling approach, indicating that it is well suited for data from studies in which fish are released to their natural environment. The model was found to be less reliable in simulations when there was a delay in discard mortality onset, though such an effect appears only in a minority of existing discard mortality studies. Overall, the model provides a flexible framework in which to analyse discard mortality data and to produce reliable scientific advice on discard mortality rates and possibilities for mitigation

Beyond reporting statistical significance: Identifying informative effect sizes to improve scientific communication.

Transparent communication of research is key to foster understanding within and beyond the scientific community. An increased focus on reporting effect sizes in addition to p value-based significance statements or Bayes Factors may improve scientific communication with the general public. Across three studies ( N = 652), we compared subjective informativeness ratings for five effect sizes, Bayes Factor, and commonly used significance statements. Results showed that Cohen's U3 was rated as most informative. For example, 440 participants (69%) found U3 more informative than Cohen's d, while 95 (15%) found d more informative than U3, with 99 participants (16%) finding both effect sizes equally informative. This effect was not moderated by level of education. We therefore suggest that in general, Cohen's U3 is used when scientific findings are communicated. However, the choice of the effect size may vary depending on what a researcher wants to highlight (e.g. differences or similarities)

Spatial housing economics: a survey

This introduction to the Virtual Special Issue surveys the development of spatial housing economics from its roots in neo-classical theory, through more recent developments in social interactions modelling, and touching on the role of institutions, path dependence and economic history. The survey also points to some of the more promising future directions for the subject that are beginning to appear in the literature. The survey covers elements hedonic models, spatial econometrics, neighbourhood models, housing market areas, housing supply, models of segregation, migration, housing tenure, sub-national house price modelling including the so-called ripple effect, and agent-based models. Possible future directions are set in the context of a selection of recent papers that have appeared in Urban Studies. Nevertheless, there are still important gaps in the literature that merit further attention, arising at least partly from emerging policy problems. These include more research on housing and biodiversity, the relationship between housing and civil unrest, the effects of changing age distributions - notably housing for the elderly - and the impact of different international institutional structures. Methodologically, developments in Big Data provide an exciting framework for future work

Chemical composition and enzymatic digestibility of sugarcane clones selected for varied lignin content

<p>Abstract</p> <p>Background</p> <p>The recalcitrance of lignocellulosic materials is a major limitation for their conversion into fermentable sugars. Lignin depletion in new cultivars or transgenic plants has been identified as a way to diminish this recalcitrance. In this study, we assessed the success of a sugarcane breeding program in selecting sugarcane plants with low lignin content, and report the chemical composition and agronomic characteristics of eleven experimental hybrids and two reference samples. The enzymatic digestion of untreated and chemically delignified samples was evaluated to advance the performance of the sugarcane residue (bagasse) in cellulosic-ethanol production processes.</p> <p>Results</p> <p>The ranges for the percentages of glucan, hemicellulose, lignin, and extractive (based on oven-dry biomass) of the experimental hybrids and reference samples were 38% to 43%, 25% to 32%, 17% to 24%, and 1.6% to 7.5%, respectively. The samples with the smallest amounts of lignin did not produce the largest amounts of total polysaccharides. Instead, a variable increase in the mass of a number of components, including extractives, seemed to compensate for the reduction in lignin content. Hydroxycinnamic acids accounted for a significant part of the aromatic compounds in the samples, with <it>p</it>-coumaric acid predominating, whereas ferulic acid was present only in low amounts. Hydroxycinnamic acids with ester linkage to the hemicelluloses varied from 2.3% to 3.6%. The percentage of total hydroxycinnamic acids (including the fraction linked to lignin through ether linkages) varied from 5.0% to 9.2%, and correlated to some extent with the lignin content. These clones released up to 31% of glucose after 72 hours of digestion with commercial cellulases, whereas chemically delignified samples led to cellulose conversion values of more than 80%. However, plants with lower lignin content required less delignification to reach higher efficiencies of cellulose conversion during the enzymatic treatment.</p> <p>Conclusion</p> <p>Some of the experimental sugarcane hybrids did have the combined characteristics of high biomass and high sucrose production with low lignin content. Conversion of glucan to glucose by commercial cellulases was increased in the samples with low lignin content. Chemical delignification further increased the cellulose conversion to values of more than 80%. Thus, plants with lower lignin content required less delignification to reach higher efficiencies of cellulose conversion during the enzymatic treatment.</p

Re-organisation of oesophago-gastric cancer care in England: progress and remaining challenges

RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are.Abstract Background Oesophago-gastric cancer services in England have been extensively reorganised since 2001 to deliver a centralised, specialist-led service. Our aim was to assess how well the National Health Service (NHS) in England met organisational standards for oesophago-gastric cancer care. Methods Questionnaires that asked about the provision of staging investigations, curative and palliative treatments and key personnel were sent in September 2007 to the lead clinician for oesophago-gastric cancer at all 30 cancer networks and 156 NHS acute trusts in England. Results Responses were received from all networks and 81% of NHS trusts. All networks provided essential staging investigations and a range of endoscopic palliative therapies. Only 16 of the 30 cancer networks discussed all patients at the specialist multi-disciplinary team meeting and 11 networks had not fully centralised curative surgery. There was also variation between NHS trusts in the integration of the palliative care team, the availability of nurse specialists and the use of dieticians to provide nutritional support. Conclusion There has been considerable progress in reforming oesophago-gastric cancer services but the process of reorganisation is still incomplete and regional differences in service provision exist that may lead to variation in patient outcomes.Published versio

Supersymmetric Vacua in Random Supergravity

We determine the spectrum of scalar masses in a supersymmetric vacuum of a general N=1 supergravity theory, with the Kahler potential and superpotential taken to be random functions of N complex scalar fields. We derive a random matrix model for the Hessian matrix and compute the eigenvalue spectrum. Tachyons consistent with the Breitenlohner-Freedman bound are generically present, and although these tachyons cannot destabilize the supersymmetric vacuum, they do influence the likelihood of the existence of an `uplift' to a metastable vacuum with positive cosmological constant. We show that the probability that a supersymmetric AdS vacuum has no tachyons is formally equivalent to the probability of a large fluctuation of the smallest eigenvalue of a certain real Wishart matrix. For normally-distributed matrix entries and any N, this probability is given exactly by P = exp(-2N^2|W|^2/m_{susy}^2), with W denoting the superpotential and m_{susy} the supersymmetric mass scale; for more general distributions of the entries, our result is accurate when N >> 1. We conclude that for |W| \gtrsim m_{susy}/N, tachyonic instabilities are ubiquitous in configurations obtained by uplifting supersymmetric vacua.Comment: 26 pages, 6 figure

Using Biologic Markers in Blood to Assess Exposure to Multiple Environmental Chemicals for Inner-City Children 3–6 Years of Age

We assessed concurrent exposure to a mixture of > 50 environmental chemicals by measuring the chemicals or their metabolites in the blood of 43 ethnically diverse children (3–6 years of age) from a socioeconomically disadvantaged neighborhood in Minneapolis. Over a 2-year period, additional samples were collected every 6–12 months from as many children as possible. We analyzed blood samples for 11 volatile organic compounds (VOCs), 2 heavy metals (lead and mercury, 11 organochlorine (OC) pesticides or related compounds, and 30 polychlorinated biphenyl (PCB) congeners. The evidence suggests that numerous VOCs originated from common sources, as did many PCBs. Longitudinal measurements indicate that between-child variance was greater than within-child variance for two VOCs (benzene, toluene), for both heavy metals (Pb, Hg), for all detectable OC pesticides, and for 15 of the measured PCB congeners (74, 99, 101, 118, 138–158, 146, 153, 156, 170, 178, 180, 187, 189, 194, 195). Despite the relatively small sample size, highest measured blood levels of 1,4-dichlorobenzene, styrene, m-/p-xylene, Pb, Hg, heptachlor epoxide, oxychlordane, dichlorodiphenyldichloroethene (p,p′-DDE), trans-nonachlor, and PCB congeners 74, 99, 105, 118, 138, 146, 153, 156, 170, and 180 were comparable with or higher than 95th percentile measurements of older children and adults from national surveys. Results demonstrate that cumulative exposures to multiple environmental carcinogens and neurotoxins can be comparatively high for children from a poor inner-city neighborhood

Logarithmic Corrections to Extremal Black Hole Entropy from Quantum Entropy Function

We evaluate the one loop determinant of matter multiplet fields of N=4 supergravity in the near horizon geometry of quarter BPS black holes, and use it to calculate logarithmic corrections to the entropy of these black holes using the quantum entropy function formalism. We show that even though individual fields give non-vanishing logarithmic contribution to the entropy, the net contribution from all the fields in the matter multiplet vanishes. Thus logarithmic corrections to the entropy of quarter BPS black holes, if present, must be independent of the number of matter multiplet fields in the theory. This is consistent with the microscopic results. During our analysis we also determine the complete spectrum of small fluctuations of matter multiplet fields in the near horizon geometry.Comment: LaTeX file, 52 pages; v2: minor corrections, references adde

Macroscopic transport by synthetic molecular machines

Nature uses molecular motors and machines in virtually every significant biological process, but demonstrating that simpler artificial structures operating through the same gross mechanisms can be interfaced with—and perform physical tasks in—the macroscopic world represents a significant hurdle for molecular nanotechnology. Here we describe a wholly synthetic molecular system that converts an external energy source (light) into biased brownian motion to transport a macroscopic cargo and do measurable work. The millimetre-scale directional transport of a liquid on a surface is achieved by using the biased brownian motion of stimuli-responsive rotaxanes (‘molecular shuttles’) to expose or conceal fluoroalkane residues and thereby modify surface tension. The collective operation of a monolayer of the molecular shuttles is sufficient to power the movement of a microlitre droplet of diiodomethane up a twelve-degree incline.