1,441 research outputs found

    Use of fractal dimensions to quantify coral shape

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    A morphometrical method to quantify and characterize coral corallites using Richardson Plots and Kaye's notion of fractal dimensions is presented. A Jurassic coral species (Aplosmilia spinosa) and five Recent coral species were compared using the Box-Counting Method. This method enables the characterization of their morphologies at calicular and septal levels by their fractal dimensions (structural and textural). Moreover, it is possible to determine differences between species of Montastraea and to tackle the high phenotypic plasticity of Montastraea annularis. The use of fractal dimensions versus conventional methods (e.g., measurements of linear dimensions with a calliper, landmarks, Fourier analyses) to explore a rugged boundary object is discussed. It appears that fractal methods have the potential to considerably simplify the morphometrical and statistical approaches, and be a valuable addition to methods based on Euclidian geometr

    Brucellosis in terrestrial wildlife

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    The epidemiological link between brucellosis in wildlife and brucellosis in livestock and people is widely recognised. When studying brucellosis in wildlife, three questions arise: (i) Is this the result of a spillover from livestock or a sustainable infection in one or more host species of wildlife? (ii) Does wildlife brucellosis represent a reservoir of Brucella strains for livestock? (iii) Is it of zoonotic concern? Despite their different host preferences, B. abortus and B. suis have been isolated from a variety of wildlife species, whereas B. melitensis is rarely reported in wildlife. The pathogenesis of Brucella spp. in wildlife reservoirs is not yet fully defi ned. The prevalence of brucellosis in some wildlife species is very low and thus the behaviour of individual animals, and interactions between wildlife and livestock, may be the most important drivers for transmission. Since signs of the disease are non-pathognomonic, defi nitive diagnosis depends on laboratory testing, including indirect tests that can be applied to blood or milk, as well as direct tests (classical bacteriology and methods based on the polymerase chain reaction [PCR]). However, serological tests cannot determine which Brucella species has induced anti-Brucella antibodies in the host. Only the isolation of Brucella spp. (or specifi c DNA detection by PCR) allows a defi nitive diagnosis, using classical or molecular techniques to identify and type specifi c strains. There is as yet no brucellosis vaccine that demonstrates satisfactory safety and effi cacy in wildlife. Therefore, controlling brucellosis in wildlife should be based on good management practices. At present, transmission of Brucella spp. from wildlife to humans seems to be linked to the butchering of meat and dressing of infected wild or feral pig carcasses in the developed world, and infected African buffalo in the developing world. In the Arctic, the traditional consumption of raw bone marrow and the internal organs of freshly killed caribou or reindeer is an important risk factor.bacteriologyBrucella sppBrucellosisEpidemiologyLivestock/wildlife interfaceSerologyWildlifePublishe

    Analisis Faktor Penurunan Tanah Terhadap Kinerja Automated Rubber Tyred Gantry Pada Terminal Peti Kemas Semarang

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    Penurunan tanah yang terjadi di Terminal Peti Kemas Semarang, khususnya pada Container Yard 05 tempat Automated Rubber Tyred Gantry beroperasi menyebabkan sistem operasi ARTG terganggu. Hal tersebut dikarenakan penurunan tanah menyebabkan kemiringan pada ARTG pad. Tujuan yang ingin dicapai dalam penulisan tugas akhir ini adalah untuk memprediksi kapan kemiringan ARTG pad pada tiap blok melewati batas toleransi supaya segera dilakukan tindakan untuk mengatasi masalah tersebut. Berdasarkan perhitungan konsolidasi, penurunan tanah pada Container Yard 05 seharusnya berhenti pada 300 sampai 360 hari setelah pekerjaan reklamasi selesai. Namun saat dilakukan pengukuran lapangan di bulan Agustus 2016 dan Maret 2017 masih terdapat penurunan tanah. Berdasarkan data pengukuran lapangan yang ada, dilakukan pendekatan berupa persamaan linear untuk memprediksi kapan masing-masing blok pelayanan ARTG sistemnya terganggu. Diprediksi Blok C akan terganggu sistemnya paling awal, yaitu pada bulan Maret 2017. Blok D akan terganggu sistemnya pada September 2017, kemudian pada bulan Februari 2018, Blok F sistemnya terganggu. Sistem Blok G akan terganggu di bulan April 2018, sedangkan sistem pada blok E diprediksi akan terganggu paling akhir yaitu bulan Juni 2019. Saran yang dapat diberikan ialah saat proses reklamasi, sebelum area reklamasi diberikan perkerasan, derajat konsolidasinya sudah harus mencapai atau mendekati 90%. Dengan demikian tanah yang ditimbun akan lebih stabil saat mulai diberikan beban operasional. Untuk blok yang sistemnya akan terganggu, dapat dilakukan pekerjaan leveling

    Low-temperature specific heat of real crystals: Possibility of leading contribution of optical and short-wavelength acoustical vibrations

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    We point out that the repeatedly reported glass-like properties of crystalline materials are not necessarily associated with localized (or quasilocalized) excitations. In real crystals, optical and short-wavelength acoustical vibrations remain damped due to defects down to zero temperature. If such a damping is frequency-independent, e.g. due to planar defects or charged defects, these optical and short-wavelength acoustical vibrations yield a linear-in-TT contribution to the low-temperature specific heat of the crystal lattices. At low enough temperatures such a contribution will prevail over that of the long-wavelength acoustical vibrations (Debye contribution). The crossover between the linear and the Debye regime takes place at TNT^* \propto \sqrt N, where NN is the concentration of the defects responsible for the damping. Estimates show that this crossover could be observable.Comment: 5 pages. v4: Error in Appendix corrected, which does not change the main results of the pape

    Trajectories of self-rated health in people with diabetes: Associations with functioning in a prospective community sample

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    © 2013 Schmitz et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Background: Self-rated health (SRH) is a single-item measure that is one of the most widely used measures of general health in population health research. Relatively little is known about changes and the trajectories of SRH in people with chronic medical conditions. The aims of the present study were to identify and describe longitudinal trajectories of self-rated health (SRH) status in people with diabetes. Methods: A prospective community study was carried out between 2008 and 2011. SRH was assessed at baseline and yearly at follow-ups (n=1288). Analysis was carried out through trajectory modeling. The trajectory groups were subsequently compared at 4 years follow-up with respect to functioning. Results: Four distinct trajectories of SRH were identified: 1) 72.2% of the participants were assigned to a persistently good SRH trajectory; 2) 10.1% were assigned to a persistently poor SRH trajectory; 3) mean SRH scores changed from good to poor for one group (7.3%); while 4) mean SRH scores changed from poor to medium/good for another group (10.4%). Those with a persistently poor perception of health status were at higher risk for poor functioning at 4 years follow-up than those whose SRH scores decreased from good to poor. Conclusions: SRH is an important predictor for poor functioning in diabetes, but the trajectory of SRH seems to be even more important. Health professionals should pay attention to not only SRH per se, but also changes in SRH over time.This work was supported by Operating Grant MOP-84574 from the Canadian Institutes of Health Research (CIHR). GG was supported by a doctoral fellowship from the CIHR. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

    Identification of a novel BET bromodomain inhibitor-sensitive, gene regulatory circuit that controls Rituximab response and tumour growth in aggressive lymphoid cancers.: CYCLON-induced Rituximab resistance

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    International audienceImmuno-chemotherapy elicit high response rates in B-cell non-Hodgkin lymphoma but heterogeneity in response duration is observed, with some patients achieving cure and others showing refractory disease or relapse. Using a transcriptome-powered targeted proteomics screen, we discovered a gene regulatory circuit involving the nuclear factor CYCLON which characterizes aggressive disease and resistance to the anti-CD20 monoclonal antibody, Rituximab, in high-risk B-cell lymphoma. CYCLON knockdown was found to inhibit the aggressivity of MYC-overexpressing tumours in mice and to modulate gene expression programs of biological relevance to lymphoma. Furthermore, CYCLON knockdown increased the sensitivity of human lymphoma B cells to Rituximab in vitro and in vivo. Strikingly, this effect could be mimicked by in vitro treatment of lymphoma B cells with a small molecule inhibitor for BET bromodomain proteins (JQ1). In summary, this work has identified CYCLON as a new MYC cooperating factor that autonomously drives aggressive tumour growth and Rituximab resistance in lymphoma. This resistance mechanism is amenable to next-generation epigenetic therapy by BET bromodomain inhibition, thereby providing a new combination therapy rationale for high-risk lymphoma

    Production of Medical Radioisotopes with High Specific Activity in Photonuclear Reactions with γ\gamma Beams of High Intensity and Large Brilliance

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    We study the production of radioisotopes for nuclear medicine in (γ,xn+yp)(\gamma,x{\rm n}+y{\rm p}) photonuclear reactions or (γ,γ\gamma,\gamma') photoexcitation reactions with high flux [(1013101510^{13}-10^{15})γ\gamma/s], small diameter (100μ\sim (100 \, \mum)2)^2 and small band width (ΔE/E103104\Delta E/E \approx 10^{-3}-10^{-4}) γ\gamma beams produced by Compton back-scattering of laser light from relativistic brilliant electron beams. We compare them to (ion,xxn+y + yp) reactions with (ion=p,d,α\alpha) from particle accelerators like cyclotrons and (n,γ\gamma) or (n,f) reactions from nuclear reactors. For photonuclear reactions with a narrow γ\gamma beam the energy deposition in the target can be managed by using a stack of thin target foils or wires, hence avoiding direct stopping of the Compton and pair electrons (positrons). (γ,γ)(\gamma,\gamma') isomer production via specially selected γ\gamma cascades allows to produce high specific activity in multiple excitations, where no back-pumping of the isomer to the ground state occurs. We discuss in detail many specific radioisotopes for diagnostics and therapy applications. Photonuclear reactions with γ\gamma beams allow to produce certain radioisotopes, e.g. 47^{47}Sc, 44^{44}Ti, 67^{67}Cu, 103^{103}Pd, 117m^{117m}Sn, 169^{169}Er, 195m^{195m}Pt or 225^{225}Ac, with higher specific activity and/or more economically than with classical methods. This will open the way for completely new clinical applications of radioisotopes. For example 195m^{195m}Pt could be used to verify the patient's response to chemotherapy with platinum compounds before a complete treatment is performed. Also innovative isotopes like 47^{47}Sc, 67^{67}Cu and 225^{225}Ac could be produced for the first time in sufficient quantities for large-scale application in targeted radionuclide therapy.Comment: submitted to Appl. Phys.

    Resonant Visible Light Modulation with Graphene

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    Fast modulation and switching of light at visible and near-infrared (vis-NIR) frequencies is of utmost importance for optical signal processing and sensing technologies. No fundamental limit appears to prevent us from designing wavelength-sized devices capable of controlling the light phase and intensity at gigaherts (and even terahertz) speeds in those spectral ranges. However, this problem remains largely unsolved, despite recent advances in the use of quantum wells and phase-change materials for that purpose. Here, we explore an alternative solution based upon the remarkable electro-optical properties of graphene. In particular, we predict unity-order changes in the transmission and absorption of vis-NIR light produced upon electrical doping of graphene sheets coupled to realistically engineered optical cavities. The light intensity is enhanced at the graphene plane, and so is its absorption, which can be switched and modulated via Pauli blocking through varying the level of doping. Specifically, we explore dielectric planar cavities operating under either tunneling or Fabry-Perot resonant transmission conditions, as well as Mie modes in silicon nanospheres and lattice resonances in metal particle arrays. Our simulations reveal absolute variations in transmission exceeding 90% as well as an extinction ratio >15 dB with small insertion losses using feasible material parameters, thus supporting the application of graphene in fast electro-optics at vis-NIR frequencies.Comment: 17 pages, 13 figures, 54 reference
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