2,832 research outputs found

    Cyanobacteria blooms cannot be controlled by effective microorganisms (EM) from mud- or Bokashi-balls

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    In controlled experiments, the ability of ‘‘Effective Microorganisms (EM, in the form of mudballs or Bokashi-balls)’’ was tested for clearing waters from cyanobacteria. We found suspensions of EM-mudballs up to 1 g l-1 to be ineffective in reducing cyanobacterial growth. In all controls and EM-mudball treatments up to 1 g l-1 the cyanobacterial chlorophyll-a (Chl-a) concentrations increased within 4 weeks from&120 to 325–435 lg l-1. When pieces of EM-mudballs (42.5 g) were added to 25-l lake water with cyanobacteria, no decrease of cyanobacteria as compared to untreated controls was observed. In contrast, after 4 weeks cyanobacterial Chl-a concentrations were significantly higher in EM-mudball treatments (52 lg l-1) than in controls (20 lg l-1). Only when suspensions with extremely high EM-mudball concentrations were applied (i.e., 5 and 10 g l-1), exceeding the recommended concentrations by orders of magnitude, cyanobacterial growth was inhibited and a bloom forming concentration was reduced strongly. In these high dosing treatments, the oxygen concentration dropped initially to very low levels of 1.8 g l-1. This was most probably through forcing strong light limitation on the cyanobacteria caused by the high amount of clay and subsequent high turbidity of the water. Hence, this study yields no support for the hypothesis that EM is effective in preventing cyanobacterial proliferation or in terminating blooms. We consider EM products to be ineffective because they neither permanently bind nor remove phosphorus from eutroficated systems, they have no inhibiting effect on cyanobacteria, and they could even be an extra source of nutrients

    Limits on a gravitational field dependence of the proton-electron mass ratio from H2 in white dwarf stars.

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    Spectra of molecular hydrogen (H2) are employed to search for a possible proton-to-electron mass ratio (μ) dependence on gravity. The Lyman transitions of H2, observed with the Hubble Space Telescope towards white dwarf stars that underwent a gravitational collapse, are compared to accurate laboratory spectra taking into account the high temperature conditions (T∼13 000  K) of their photospheres. We derive sensitivity coefficients Ki which define how the individual H2 transitions shift due to μ dependence. The spectrum of white dwarf star GD133 yields a Δμ/μ constraint of (-2.7±4.7stat±0.2syst)×10(-5) for a local environment of a gravitational potential ϕ∼10(4) ϕEarth, while that of G29-38 yields Δμ/μ=(-5.8±3.8stat±0.3syst)×10(-5) for a potential of 2×10(4) ϕEarth.This work was supported by the FOM-Program \Bro- ken Mirrors & Drifting Constant", Science and Technol- ogy Facilities Council, Templeton Foundation and Aus- tralian Research Council (DP110100866).This is the accepted manuscript. The final version is available from APS at http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.113.123002

    Synovial cell metabolism and chronic inflammation in rheumatoid arthritis

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    Metabolomic studies of body fluids show that immune-mediated inflammatory diseases such as rheumatoid arthritis (RA) are associated with metabolic disruption. This is likely to reflect the increased bioenergetic and biosynthetic demands of sustained inflammation and changes to nutrient and oxygen availability in damaged tissue. The synovial membrane lining layer is the principle site of inflammation in RA. Here the resident cells are the fibroblast-like synoviocytes (FLS) and the synovial tissue macrophages (STM), which are transformed toward overproduction of enzymes which degrade cartilage and bone, and cytokines which promote immune cell infiltration. Recent studies have shown metabolic changes in both FLS and macrophages from RA patients and these may be therapeutically targetable. However, as the origins and subset specific functions of synoviocytes are poorly understood and the signaling modules which control metabolic deviation in RA synovial cells are yet to be explored, significant additional research is needed to translate these findings toward clinical application. Furthermore, in many inflamed tissues, different cell types can forge metabolic collaborations through solute carriers (SLC) in their membranes, to meet a high demand for energy or biomolecules. Such relationships are likely to exist in the synovium and are yet to be explored. Finally, it is not yet known whether metabolic change is a consequence of disease or if primary changes to cellular metabolism might underlie or contribute to early stage disease pathogenesis. This article collates what is known about metabolism in synovial tissue cells and highlights future research directions in this area

    Young infants' visual fixation patterns in addition and subtraction tasks support an object tracking account.

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    This is the final version of the article. Available from Elsevier via the DOI in this record.Investigating infants' numerical ability is crucial to identifying the developmental origins of numeracy. Wynn (1992) claimed that 5-month-old infants understand addition and subtraction as indicated by longer looking at outcomes that violate numerical operations (i.e., 1+1=1 and 2-1=2). However, Wynn's claim was contentious, with others suggesting that her results might reflect a familiarity preference for the initial array or that they could be explained in terms of object tracking. To cast light on this controversy, Wynn's conditions were replicated with conventional looking time supplemented with eye-tracker data. In the incorrect outcome of 2 in a subtraction event (2-1=2), infants looked selectively at the incorrectly present object, a finding that is not predicted by an initial array preference account or a symbolic numerical account but that is consistent with a perceptual object tracking account. It appears that young infants can track at least one object over occlusion, and this may form the precursor of numerical ability.This research was funded by a grant from the Nuffield Foundation (SGS/32130) to the first author, a grant from the Economic and Social Research Council (RES-000-22-1113 and ES/K000934/1) to the first author, and grants from the National Institutes of Health (HD-48733 and HD-40432) to the last author. We thank the infants and parents for contributing to the research

    The effects of three days of sub-maximal-intensity mountain biking on sleep

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    Objectives. We determined the effect of three consecutive days of sub-maximal-intensity mountain biking (4.5 hours per day, ~64 km per day), on the sleep of ten healthy, trained male and female mountain bikers. Methods. The sleep of the mountain bikers was assessed both subjectively (visual analogue scales and sleep questionnaires) and objectively (activity data logger) on each night of mountain biking and for seven nights when they were not cycling (pre-exercise, mean of seven nights). The cyclists’ mood and muscular pain were assessed each night using visual analogue scales. The cyclists slept at home in their normal environment. Results. There was no significant difference between the mountain bikers’ muscular pain and mood (calm/anxious visual analogue scale) measured during the pre-exercise stage and their pain and mood measured on each of the mountain biking nights (p>0.05). However, compared with the pre-exercise stage, the mountain bikers reported that they were significantly more tired (tired/energetic visual analogue scale) on each night of cycling (p<0.01). The sleep of the mountain bikers was disrupted on the night of the third day of mountain biking only. On this night, compared with the pre-exercise stage, the mountain bikers reported that they woke up more during the night (double the number of times) (p<0.001), and an activity data logger recorded that they were awake for about half an hour longer during the night (p<0.05). Conclusion. We have shown that three days of repeated, endurance sub-maximal mountain biking disrupted the sleep of the mountain bikers on the third night of cycling

    Criatividade no uso de ferramentas pedagógicas: novo paradigma educacional em curso de graduação

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    Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro TecnológicoNesta nova era da globalização, em constantes evoluções tecnológicas, a inovação tem feito a diferença. Neste estudo, analisa-se o uso da tecnologia na aprendizagem, avaliando a associação da inovação à criatividade, e à ligação motivação-aluno-professor, como ferramentas que tornam o processo pedagógico viável. Considerando a importância da criatividade no comportamento e no trabalho humano, utilizamos a técnica do incidente crítico para avaliar aspectos da criatividade do professor. Este trabalho é um estudo não experimental, do tipo pós-facto-retrospectivo. Através de questionário e entrevista foram analisados estatisticamente o comportamento do professor no uso das várias ferramentas pedagógicas e sua influência na motivação e aprendizado dos alunos. Identificamos nos relatos os incidentes críticos, extraímos, categorizamos e relacionamos as situações, comportamentos e conseqüências. Dos 44 relatos obtivemos 76 situações das quais extraímos o uso de diferentes metodologias sendo 17 situações utilizando métodos tradicionais; 35 utilizando métodos interativos e 24 utilizando métodos com ferramenta tecnológica, 81 comportamentos adequados e inadequados, 85 consequências para os alunos, 47 consequências para a aprendizagem e 20 consequências da metodologia usada. Finalmente, discutimos os resultados e algumas questões e conclusões sobre a criatividade no uso das ferramentas pedagógicas pelo professor foram levantada

    Fluorodeoxyglucose-positron emission tomography/computed tomography in the staging and evaluation of treatment response in a patient with Castleman's disease: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Castleman's disease is a rare lymphatic polyclonal disorder that is characterised by unicentric or multicentric lymph node hyperplasia and non-specific symptoms and signs including fever, asthenia, weight loss, enlarged liver and abnormally high blood levels of antibodies.</p> <p>Case presentation</p> <p>We present the case of a 74-year-old man with Castleman's disease. The disease was detected with a contrast-enhanced computed tomography (CT) scan and a fluorodeoxyglucose (FDG)-positron emission tomography (PET)/CT study; diagnosis was made with histopathology. After treatment with surgical excision followed by chemotherapy, the disease response was evaluated using both diagnostic techniques. However, only the PET study was able to identify the spread of the disease to the abdominal lymph nodes, which were both enlarged and normal size, and, after treatment, to evaluate the disease response.</p> <p>Conclusion</p> <p>Based on the results of previous case reports and on those of the present study, it seems that Castleman's disease has a high glucose metabolic activity. Therefore, the use of PET can be considered appropriate in order to stage or restage the disease and to evaluate the response of the disease to treatment.</p

    Finding Plastic Patches in Coastal Waters using Optical Satellite Data

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    Satellites collecting optical data offer a unique perspective from which to observe the problem of plastic litter in the marine environment, but few studies have successfully demonstrated their use for this purpose. For the first time, we show that patches of floating macroplastics are detectable in optical data acquired by the European Space Agency (ESA) Sentinel-2 satellites and, furthermore, are distinguishable from naturally occurring materials such as seaweed. We present case studies from four countries where suspected macroplastics were detected in Sentinel-2 Earth Observation data. Patches of materials on the ocean surface were highlighted using a novel Floating Debris Index (FDI) developed for the Sentinel-2 Multi-Spectral Instrument (MSI). In all cases, floating aggregations were detectable on sub-pixel scales, and appeared to be composed of a mix of seaweed, sea foam, and macroplastics. Building first steps toward a future monitoring system, we leveraged spectral shape to identify macroplastics, and a Naïve Bayes algorithm to classify mixed materials. Suspected plastics were successfully classified as plastics with an accuracy of 86

    Assortment optimisation under a general discrete choice model: A tight analysis of revenue-ordered assortments

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    The assortment problem in revenue management is the problem of deciding which subset of products to offer to consumers in order to maximise revenue. A simple and natural strategy is to select the best assortment out of all those that are constructed by fixing a threshold revenue π\pi and then choosing all products with revenue at least π\pi. This is known as the revenue-ordered assortments strategy. In this paper we study the approximation guarantees provided by revenue-ordered assortments when customers are rational in the following sense: the probability of selecting a specific product from the set being offered cannot increase if the set is enlarged. This rationality assumption, known as regularity, is satisfied by almost all discrete choice models considered in the revenue management and choice theory literature, and in particular by random utility models. The bounds we obtain are tight and improve on recent results in that direction, such as for the Mixed Multinomial Logit model by Rusmevichientong et al. (2014). An appealing feature of our analysis is its simplicity, as it relies only on the regularity condition. We also draw a connection between assortment optimisation and two pricing problems called unit demand envy-free pricing and Stackelberg minimum spanning tree: These problems can be restated as assortment problems under discrete choice models satisfying the regularity condition, and moreover revenue-ordered assortments correspond then to the well-studied uniform pricing heuristic. When specialised to that setting, the general bounds we establish for revenue-ordered assortments match and unify the best known results on uniform pricing.Comment: Minor changes following referees' comment

    The calcium activated nucleotidases: A diverse family of soluble and membrane associated nucleotide hydrolyzing enzymes

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    It has long been known that the salivary glands of hematophagous (blood-feeding) arthropods secrete soluble apyrases, which are potent nucleotide hydrolyzing enzymes capable of hydrolyzing extracellular ATP and ADP, the latter being a major agonist contributing to platelet aggregation. Only recently, however, has the identification of proteins homologous to these apyrases been reported in non-blood-feeding organisms such as rodents and humans. In this review, we present an overview of the diverse family of apyrases first described in the blood-feeding arthropods, including the identification and characterization of the soluble and membrane-bound vertebrate enzymes homologous to these arthropod apyrases. We also describe the enzymatic properties and nucleotide specificities of the expressed enzymes, and insights gained into the structure and function of this calcium activated nucleotidase (CAN) family from biophysical, mutagenesis and crystallography studies. The potential therapeutic value of these proteins is also discussed
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