Major shifts at the range edge of marine forests: the combined effects of climate changes and limited dispersal

Global climate change is likely to constrain low latitude range edges across many taxa and habitats. Such is the case for NE Atlantic marine macroalgal forests, important ecosystems whose main structuring species is the annual kelp Saccorhiza polyschides. We coupled ecological niche modelling with simulations of potential dispersal and delayed development stages to infer the major forces shaping range edges and to predict their dynamics. Models indicated that the southern limit is set by high winter temperatures above the physiological tolerance of overwintering microscopic stages and reduced upwelling during recruitment. The best range predictions were achieved assuming low spatial dispersal (5 km) and delayed stages up to two years (temporal dispersal). Reconstructing distributions through time indicated losses of similar to 30% from 1986 to 2014, restricting S. polyschides to upwelling regions at the southern edge. Future predictions further restrict populations to a unique refugium in northwestern Iberia. Losses were dependent on the emissions scenario, with the most drastic one shifting similar to 38% of the current distribution by 2100. Such distributional changes might not be rescued by dispersal in space or time (as shown for the recent past) and are expected to drive major biodiversity loss and changes in ecosystem functioning.Electricity of Portugal (Fundo EDP para a Biodiversidade); FCT - Portuguese Science Foundation [PTDC/MAR-EST/6053/2014, EXTANT-EXCL/AAG-GLO/0661/2012, SFRH/BPD/111003/2015

Integration of supply and demand for water in Central Illinois urban areas

Water demand functions were estimated using two sets of data for Central Illinois -- community-wide data and household data. The community-wide data consist of total residential consumption for each of four pre-selected medium-sized cities in Central Illinois. The household data consist of residents from five cities who responded to a mail survey. This study investigates comparability of parameter estimates from the two approaches. If the parameter estimates are comparable, it would suggest water demand estimates need not require costly and time-consuming household surveys. Estimates of price elasticity are negative and less than unitary based on the two data sets used. The estimated price elasticity based on community-wide data is -.037, while using household data estimated price elasticities are in the range from -.I4 to -.16. Estimated income elasticities for central Illinois households are positive. The estimated income elasticity based on community-wide data is 1.57 while the estimated income elasticity based on household data ranges from .0759 to .316. In comparing results of the general demand model based on the two sets of data, there is wide disparity in the values of the estimated price and income elasticities. The reasons for these differences are not immediately apparent and warrant further investigation.U.S. Department of the InteriorU.S. Geological SurveyOpe

Phosphoethanolamine And Omega-3 In Patients With Asthma

The effect of omega-3 (n-3) in asthma has been inconclusive. One explanation for it may be the low incorporation of these fatty acids in clinical studies. Phosphoethanolamine (PEtn) can increase the synthesis of phosphatidylethanolamine, which can, in turn, increase the incorporation of n-3 in cell membranes. The aim of this study is to evaluate the effect of synthetic PEtn in patients with asthma who are receiving n-3. This randomized, double-blind, placebo-controlled study was carried out over a two month period by using spirometry, the Asthma Control Test questionnaire (ACT) and medicine intake. Forty-one patients with asthma were studied. Twenty-one patients received n-3 daily (1.080 mg of EPA, 720 mg of DHA) and 800 mg of PEtn (PEtn group), and twenty patients received the same doses of n-3 and placebo (control group). All patients continued receiving their conventional treatment for asthma. The hospital ethics committee approved the study. Five patients of each group required systemic corticosteroids, being the total consumption, Smaller in the PEtn group (127.4 mg of prednisone/patient versus 416.0 mg of prednisone/patient in the control group, p-value = 0.0269). There were no significant differences in the changing of ATC and FEV1, as well as in the intake of formoterol or budesonide between the groups. In this study, patients who received phosphoethanolamine and omega-3 needed a Smaller dose of systemic corticosteroid for asthma control than patients who only received omega-3. However, as the trial was conducted on a Small scale, more studies are necessary.99185431854

Self-similarity and novel sample-length-dependence of conductance in quasiperiodic lateral magnetic superlattices

We study the transport of electrons in a Fibonacci magnetic superlattice produced on a two-dimensional electron gas modulated by parallel magnetic field stripes arranged in a Fibonacci sequence. Both the transmission coefficient and conductance exhibit self-similarity and the six-circle property. The presence of extended states yields a finite conductivity at infinite length, that may be detected as an abrupt change in the conductance as the Fermi energy is varied, much as a metal-insulator transition. This is a unique feature of transport in this new kind of structure, arising from its inherent two-dimensional nature.Comment: 9 pages, 5 figures, revtex, important revisions made. to be published in Phys. Rev.

Immobilized lysozyme protein on fibrous medium: Preliminary results for microfiltration applications

The protein lysozyme was deposited onto a permeable support comprising chemically functionalized glass fiber. The main objective of this study was to set a stable organic net with no effect on the medium bed permeability and a preliminary test the activity of this enzyme under immobilized conditions. The film formation is followed by atomic force microscopy (AFM) surface imaging. The effect on the bacteria Escherichia coli was tested using a simple microfiltration column. The filtration results pointed around 75% removal of bacteria in the effluent when compared to the influent concentration. The removal mechanism is assumed as being essentially due biointeraction. The surface polarity characteristics of the formed film were also considered as playing an important role, suggesting an electrostatic interaction mechanism in the microorganism removal

Multi-step thermally induced transitions of ß-lactoglobulin - an in situ spectroscopy approach

An in-situ approach based in multiple spectroscopic techniques and benchmarked with DSC was used to characterise ß-Lg thermally-induced transitions. The methodology applied overcomes previously reported limitations, by ensuring similar experimental conditions in different determinations, non-aggregation conditions and allowing distinguishing between fluorescent variations due to collisional quenching and structural modifications. These experimental improvements along with the correlation of complementary data from the assessment of several unfolding-related events, allowed a real time, precise and detailed description of the unfolding/refolding pathways of ß-Lg. The existence of a complex multi-step unfolding mechanism was confirmed, with a focus on the reversible conformational changes. The elusive unfolding intermediates were characterised in terms of structural swelling, hydrophobic sites accessibility and tryptophan exposure. This approach allowed establishing a clear order of events during thermally-induced structural changes, representing a step forward in the understanding of protein stability and interactions, useful, e.g., when establishing heat treatments of dairy products.This study was supported by the Portuguese Foundation for Science and Technology under the scope of the strategic funding of UID/BIO/04469/2013 unit and of UID/QUI/0081/2013 unit, and COMPETE 2020 (POCI-01-0145-FEDER-006684 and POCI-01-0145-FEDER-006980), Biotecnorte Operation (NORTE-01-0145-FEDER-000004) and Norte-01-0145-FEDER-000028 funded by European Regional Development Fund under the scope of Norte2020 – Programa Operacional Regional do Norte. The authors Rui M. Rodrigues, Ricardo N. Pereira, also thank to FCT their financial grants with SFRH/BD/110723/2015, SFRH/BPD/81887/2011, respectively and Bárbara Claro thanks Norte2020 - Programa Operacional Regional do Norte for a Master grant under the project Norte-01-0145-FEDER-000028.info:eu-repo/semantics/publishedVersio

Dynamic instabilities in resonant tunneling induced by a magnetic field

We show that the addition of a magnetic field parallel to the current induces self sustained intrinsic current oscillations in an asymmetric double barrier structure. The oscillations are attributed to the nonlinear dynamic coupling of the current to the charge trapped in the well, and the effect of the external field over the local density of states across the system. Our results show that the system bifurcates as the field is increased, and may transit to chaos at large enough fields.Comment: 4 pages, 3 figures, accepted in Phys. Rev. Letter

Economic Design of X Control Charts for Monitoring a First Order Autoregressive Process

In this paper we deal with the economic design of an X control chart used to monitor a quality characteristic whose observations fit to a first order autoregressive model. The Duncan cost model is used to select the control chart parameters, namely the sample size (n), the sampling interval (h) and the control limit coefficient (k), that lead to the optimal monitoring cost. We found that the autocorrelation has an adverse effect on the chart’s power, on the false alarm risk and on the cost. It also increases n and h and decreases k. To counteract this undesired effect we considered setting up the subgroups using non-sequential observations. It is shown that this sampling strategy significantly reduces the monitoring cost.

A Tale of Two Fractals: The Hofstadter Butterfly and The Integral Apollonian Gaskets

This paper unveils a mapping between a quantum fractal that describes a physical phenomena, and an abstract geometrical fractal. The quantum fractal is the Hofstadter butterfly discovered in 1976 in an iconic condensed matter problem of electrons moving in a two-dimensional lattice in a transverse magnetic field. The geometric fractal is the integer Apollonian gasket characterized in terms of a 300 BC problem of mutually tangent circles. Both of these fractals are made up of integers. In the Hofstadter butterfly, these integers encode the topological quantum numbers of quantum Hall conductivity. In the Apollonian gaskets an infinite number of mutually tangent circles are nested inside each other, where each circle has integer curvature. The mapping between these two fractals reveals a hidden threefold symmetry embedded in the kaleidoscopic images that describe the asymptotic scaling properties of the butterfly. This paper also serves as a mini review of these fractals, emphasizing their hierarchical aspects in terms of Farey fractions