5,095 research outputs found

    A formal account of dishonesty

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    International audienceThis paper provides formal accounts of dishonest attitudes of agents. We introduce a propositional multi-modal logic that can represent an agent's belief and intention as well as communication between agents. Using the language, we formulate different categories of dishonesty. We first provide two different definitions of lies and provide their logical properties. We then consider an incentive behind the act of lying and introduce lying with objectives. We subsequently define bullshit, withholding information and half-truths, and analyze their formal properties. We compare different categories of dishonesty in a systematic manner, and examine their connection to deception. We also propose maxims for dishonest communication that agents should ideally try to satisfy

    Damped Lyman alpha Absorbing Galaxies At Low Redshifts z<1 From Hierarchical Galaxy Formation Models

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    We investigate Damped Ly-alpha absorbing galaxies (DLA galaxies) at low redshifts z<1 in the hierarchical structure formation scenario to clarify the nature of DLA galaxies because observational data of such galaxies mainly at low redshifts are currently available. We find that our model well reproduces distributions of fundamental properties of DLA galaxies such as luminosities, column densities, impact parameters obtained by optical and near-infrared imagings. Our results suggest that DLA systems primarily consist of low luminosity galaxies with small impact parameters (typical radius about 3 kpc, surface brightness from 22 to 27 mag arcsec^{-2}) similar to low surface brightness (LSB) galaxies. In addition, we investigate selection biases arising from the faintness and from the masking effect which prevents us from identifying a DLA galaxy hidden or contaminated by a point spread function of a background quasar. We find that the latter affects the distributions of DLA properties more seriously rather than the former, and that the observational data are well reproduced only when taking into account the masking effect. The missing rate of DLA galaxies by the masking effect attains 60-90 % in the sample at redshift 0<z<1 when an angular size limit is as small as 1 arcsec. Furthermore we find a tight correlation between HI mass and cross section of DLA galaxies, and also find that HI-rich galaxies with M(HI) \sim 10^{9} M_sun dominate DLA systems. These features are entirely consistent with those from the Arecibo Dual-Beam Survey which is a blind 21 cm survey. Finally we discuss star formation rates, and find that they are typically about 10^{-2} M_sun yr^{-1} as low as those in LSB galaxies.Comment: 21 pages, 13 figures, Accepted for publication in Astrophsical Journa

    Ontwikkeling en implementatie van geĂŻntegreerde bestrijding in zomerbloemen : toepassing van beschikbare producten en ontwikkeling van nieuwe natuurlijke vijanden

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    In 2008 en 2009 werden loslatingen verricht van de roofmijten Neoseiulus cucumeris en Amblyseius andersoni, soms aangevuld met Phytoseiulus persimilis, in de zomerbloemen rozenbottel, chrysant, Veronica, Alchemilla en Delphinium. Hierbij bleek dat roofmijten zich niet in alle gewassen in gelijke mate vestigen. In Alchemilla en Delphinium bleek al spontaan Neoseiulus cucumeris voor te kunnen komen. Als in deze gewassen nog geen roofmijten voorkomen, zal introductie van N. cucumeris zeker slagen, mits er geen breedwerkende middelen worden toegepast. Vooral Alchemilla bleek een goede roofmijtenplant te zijn. Behalve Neoseiulus cucumeris werden ook andere soorten gevonden. Roofmijten die in de handel zijn tegen spint, Phytoseiulus persimilis en Neoseiulus californicus, vestigen zich eveneens goed in dit gewas, in tegenstelling tot Amblyseius andersoni. Verder kunnen spontaan andere natuurlijke vijanden van plagen voorkomen: roofwantsen, gaasvliegen en galmuggen. Trips nam in beide jaren af gedurende de teelt of bleef op een laag niveau. Neoseiulus alpinus is een roofmijt, die eerder is verzameld van Alchemilla en in kweek genomen. Een loslating van deze roofmijt in Alchemilla slaagde in 2008 niet, maar in 2009 wel. In Delphinium was in 2008 vanaf het begin van de waarnemingen Neoseiulus cucumeris in het gewas aanwezig. Na introductie van Amblyseius andersoni werd ook deze soort teruggevonden. Spint kwam in 2008 niet tot ontwikkeling. Buiten de proef kwam plaatselijk cyclamenmijt voor. In 2009 werd in Delphinium zwavel verdampt tegen echte meeldauw. Er was geen goede vestiging van roofmijten in het gewas, ook niet van de roofmijt Phytoseiulus persimilis, waardoor chemische bestrijding van spint noodzakelijk was. In Veronica, chrysant en rozenbottel kwamen in vergelijking met Alchemilla en Delphinium minder roofmijten voor. Trips en spint waren in 2008 en 2009 geen probleem in Veronica, chrysant en rozenbottel. Op rozenbottel kwam zonder introductie Neoseiulus cucumeris voor. Andere soorten roofmijten, die soms spontaan optraden waren Neoseiulus reductus in Delphinium, Amblyseius graminis in Alchemilla en chrysant, en roofmijten die tot een andere groep (Bdelloidea) behoren, met name op chrysant en Veronica

    Growth of children with Langerhans cell histiocytosis

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    Conclusion: GH deficiency is not a common manifestation of LCH in childhood and GH provocation tests are only indicated when there is a poor or decelerating growth rate. In our patients the number of organs involved and/or the treatment modality did not influence the growth in all but one. Diseases in childhood have an impact on growth. The influence of Langerhans cell histiocytosis (LCH) on growth has never been studied well. Recently a patient with LCH was treated with human growth hormone (GH) because of severe GH deficiency due to LCH involvement of both the hypothalamus and pituitary. This led us to review our charts from 1971 onward for evaluation of the growth patterns in patients with LCH. Here the long-term growth of 22 patients with LCH is reported, the median follow up being 7 years and 1 month. The height data were converted into standard deviation scores (SDS). At diagnosis the mean SDS of patients with isolated LCH at diagnosis was 0.04 and -0.37 in patients with disseminated LCH. Of the total group, 12 patients did not show any influence from the LCH or therapy on their growth. The remaining 10 patients reached, after a minimum of 3 years, a percentile clearly higher than that at diagnosis. However all the ten above mentioned patients, either isolated or disseminated LCH, had a lesion in the facial side of the skull

    Biomechanical Analysis of Reducing Sacroiliac Joint Shear Load by Optimization of Pelvic Muscle and Ligament Forces

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    Effective stabilization of the sacroiliac joints (SIJ) is essential, since spinal loading is transferred via the SIJ to the coxal bones, and further to the legs. We performed a biomechanical analysis of SIJ stability in terms of reduced SIJ shear force in standing posture using a validated static 3-D simulation model. This model contained 100 muscle elements, 8 ligaments, and 8 joints in trunk, pelvis, and upper legs. Initially, the model was set up to minimize the maximum muscle stress. In this situation, the trunk load was mainly balanced between the coxal bones by vertical SIJ shear force. An imposed reduction of the vertical SIJ shear by 20% resulted in 70% increase of SIJ compression force due to activation of hip flexors and counteracting hip extensors. Another 20% reduction of the vertical SIJ shear force resulted in further increase of SIJ compression force by 400%, due to activation of the transversely oriented M. transversus abdominis and pelvic floor muscles. The M. transversus abdominis crosses the SIJ and clamps the sacrum between the coxal bones. Moreover, the pelvic floor muscles oppose lateral movement of the coxal bones, which stabilizes the position of the sacrum between the coxal bones (the pelvic arc). Our results suggest that training of the M. transversus abdominis and the pelvic floor muscles could help to relieve SI-joint related pelvic pain

    Effects of Maturity and Drying Method on the Nutritive Value of Tropical Grasses in Nicaragua

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    Tropical grasses are key components for both grazing and conserved forages in sustainable livestock systems (beef and dairy) in Central America. The objective of the study was to evaluate grasses used in Nicaragua and their nutritive value contribution as preserved forage during the dry season under different drying methods. Five tropical bunch grasses (Andropogon gayanus, Hyparrheniarufa, Urochloabrizantha, Megathyrsus maximus, and Cenchruspurpureus) were sampled across different farms in Nicaragua in 2014 and 2015 using three replications. Forage samples were collected at 2, 4, 6, and 8-wk maturity as well as season long samples. Samples drying methods included sun- and oven-dried. Sun-dried samples were air dried outdoors for five days while oven-driedused forced air at 55 oC. Samples were analyzed for nutritive value using wet chemistry protocols for crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF) and in vitro total digestibility (IVTD). Drying methods did not influence CP, ADF, NDF and IVTD concentrations. There were significant differences among grass species in CP levels (P= 0.0003), ADF (P= 0.0009), and IVTD (P= 0.0083). U.brizantha had the greatest CP concentration (79 g/kg) while C. purpureus had the lowest CP (44 g/kg). U. brizantha had the lowest ADF (340 g/kg) concentration. Species A. gayanus, H. rufa, and Megathyrsus maximus had similar NDF concentrations. In vitro total digestibility ranged from 680 to 750 g/kg with M. maximus having the lowest digestibility. Significant differences in forages nutritive value were observed among maturity stages for CP (P\u3c 0.0001), ADF (P= 0.0022), NDF (P= 0.0006), and IVTD (P= 0.0241), but U. brizantha maintained higher CP and IVTD concentrations compared other species, indicating that could be a more preferred species for off-season feeding

    Improved lattice operators: the case of the topological charge density

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    We analyze the properties of a class of improved lattice topological charge density operators, constructed by a smearing-like procedure. By optimizing the choice of the parameters introduced in their definition, we find operators having (i) a better statistical behavior as estimators of the topological charge density on the lattice, i.e. less noisy; (ii) a multiplicative renormalization much closer to one; (iii) a large suppression of the perturbative tail (and other unphysical mixings) in the corresponding lattice topological susceptibility.Comment: 11 pages (REVTEX) + 4 (uuencoded) figure

    Planetary Nebulae as Probes of Stellar Evolution and Populations

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    Planetary Nebulae (PNe) have been used satisfactory to test the effects of stellar evolution on the Galactic chemical environment. Moreover, a link exists between nebular morphology and stellar populations and evolution. We present the latest results on Galactic PN morphology, and an extension to a distance unbiased and homogeneous sample of Large Magellanic Cloud PNe. We show that PNe and their morphology may be successfully used as probes of stellar evolution and populations.Comment: to appear in: Chemical Evolution of the Milky Way: stars versus clusters, ed. F. Giovannelli and F. Matteucci, Kluwer (2000), in pres

    Measurement of the half-life of the T=12\frac{1}{2} mirror decay of 19^{19}Ne and its implication on physics beyond the standard model

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    The 12+→12+\frac{1}{2}^+ \rightarrow \frac{1}{2}^+ superallowed mixed mirror decay of 19^{19}Ne to 19^{19}F is excellently suited for high precision studies of the weak interaction. However, there is some disagreement on the value of the half-life. In a new measurement we have determined this quantity to be T1/2T_{1/2} = 17.2832±0.0051(stat)17.2832 \pm 0.0051_{(stat)} ±0.0066(sys)\pm 0.0066_{(sys)} s, which differs from the previous world average by 3 standard deviations. The impact of this measurement on limits for physics beyond the standard model such as the presence of tensor currents is discussed.Comment: 5 pages, 3 figures, 1 tabl

    Thermodynamics of lattice QCD with two light quark flavours on a 16^3 x 8 lattice II

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    We have extended our earlier simulations of the high temperature behaviour of lattice QCD with two light flavours of staggered quarks on a 163×816^3 \times 8 lattice to lower quark mass (m_q=0.00625). The transition from hadronic matter to a quark-gluon plasma is observed at 6/g2=5.49(2)6/g^2=5.49(2) corresponding to a temperature of Tc≈140T_c \approx 140MeV. We present measurements of observables which probe the nature of the quark-gluon plasma and serve to distinguish it from hadronic matter. Although the transition is quite abrupt, we have seen no indications that it is first order.Comment: 23 pages, RevteX, 6 encapsulated postscript figure
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