338 research outputs found

    A statistical mechanics description of environmental variability in metabolic networks

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    Many of the chemical reactions that take place within a living cell are irreversible. Due to evolutionary pressures, the number of allowable reactions within these systems are highly constrained and thus the resulting metabolic networks display considerable asymmetry. In this paper, we explore possible evolutionary factors pertaining to the reduced symmetry observed in these networks, and demonstrate the important role environmental variability plays in shaping their structural organization. Interpreting the returnability index as an equilibrium constant for a reaction network in equilibrium with a hypothetical reference system, enables us to quantify the extent to which a metabolic network is in disequilibrium. Further, by introducing a new directed centrality measure via an extension of the subgraph centrality metric to directed networks, we are able to characterise individual metabolites by their participation within metabolic pathways. To demonstrate these ideas, we study 116 metabolic networks of bacteria. In particular, we find that the equilibrium constant for the metabolic networks decreases significantly in-line with variability in bacterial habitats, supporting the view that environmental variability promotes disequilibrium within these biochemical reaction system

    Probable overwintering of adult Hyalomma rufipes in Central Europe

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    Hyalomma spp. ticks (Acari: Ixodidae) represent a public health threat because of their prominent role in the transmission of Crimean- Congo haemorrhagic fever (CCHF) virus. Moreover, these ticks can transmit other medically important arboviruses such as Thogoto, Dhori, West Nile, and Bhanja viruses; human pathogenic bacteria like Rickettsia conorii, R. aeschlimannii, and Anaplasma marginale; and protozoans like Theileria annulata and Babesia caballi (Huba ´lek and Rudolf, 2011). Many records of larval and nymphal H. marginatum ticks on birds migrating from North Africa and Southern Europe into Central and Northern Europe have been published

    First findings and molecular data of phlebotomus mascittii (diptera: Psychodidae) in the cantabrian cornice (northern spain)

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    Phlebotomus (Transphlebotomus) mascittii Grassi, 1908 (Diptera: Psychodidae) has been found in several European countries. In Spain, sporadic records were reported in the early ''80s in Catalonia (Northeast Spain), and it was never detected again. Recent entomological surveys carried out between 2004 and 2020 revealed the presence of several specimens of P. mascittii in Spain. The species identification was confirmed by both morphological and molecular analyses. The analyzed specimens belonged to the haplotype (COI_2) defined by one polymorphic site compared to other European specimens. Phlebotomus mascittii was found in low population densities in rural areas associated with livestock farms and in an urban cemetery during the summer season. This study provides the first records of this species in various localities along the Cantabrian cornice (Northern Spain) and represents its westernmost observation in the Palearctic region. The implications of the finding of this uncommon species are discussed at different levels, with emphasis on its suspected role in the transmission of leishmaniosis. © The Author(s) 2021

    Mitigación del colapso de las cubiertas ligeras de fibrocemento ante vientos huracanados

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    The Caribbean region, the Gulf of Mexico and the Strait of Florida, is an area of high vulnerability to high-level hurricanes. Light covers are the most vulnerable during the occurrence of these phenomena, their collapse generates a great danger to the life of the residents of these homes, as well as a high economic and social impact. The objective of this research has been the characterization of the lightweight fiber cement roofs (asbestos-cement) most commonly used in Cuba and through the modeling of the Finite Element Method to determine the causes of the collapse of these when extreme winds occur due to high intensity hurricanes, perform the comparative analysis of the resistive behavior of the covers studied and to mitigate the collapse of the covered ones.La región del Caribe, el Golfo de México y el Estrecho de la Florida es una zona de alta vulnerabilidad ante huracanes de altas categorías. Las cubiertas ligeras son los elementos más vulnerables durante la ocurrencia de estos fenómenos, su colapso genera un gran peligro para la vida de los habitantes de estas viviendas, así como un alto impacto económico y social en las mismas y en obras sociales e industriales. El objetivo de esta investigación ha sido la caracterización de las cubiertas ligeras de fibrocemento (amianto-cemento) más utilizadas en Cuba y, a través de la modelación por el Método de los Elementos Finitos, determinar las causas del colapso de éstas cuando ocurren vientos extremos producidos por huracanes de alta intensidad, realizar el análisis comparativo del comportamiento resistivo de las cubiertas estudiadas y mitigar el colapso de las mismas

    Otras aplicaciones docentes del Atlas Digital de Petrología Sedimentaria a través del Campus Virtual UCM (www.ucm.es/info/petrosed)

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    La Petrología Sedimentaria se adapta a las necesidades profesionales que demanda la sociedad y entre ellas el sector de la construcción. Preparar a los futuros profesionales plantea un reto no solo en la Facultad de CC. Geológicas (UCM) sino en otras muchas, sobre todo a la hora de diseñar y desarrollar el material y las herramientas didácticas que el alumno precisa en su autoaprendizaje. La asignatura Materiales de Construcción, impartida en la Facultad de CC. Geológicas (UCM) (Grado de Ingeniería Geológica), utiliza, a través de Campus Virtual, el Atlas de Petrología Sedimentaria: http://www.ucm.es/info/petrosed, ya que recoge un material didáctico fundamental para el desarrollo de gran parte de sus clases prácticas y teóricas. Esta asignatura muestra una gran afinidad con la temática y la metodología de trabajo que se emplea en la asignatura Petrología Sedimentaria, a pesar de pertenecer a campos científico-técnicos diferentes

    Evidence of the Importance of Host Habitat Use in Predicting the Dilution Effect of Wild Boar for Deer Exposure to Anaplasma spp

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    Foci of tick-borne pathogens occur at fine spatial scales, and depend upon a complex arrangement of factors involving climate, host abundance and landscape composition. It has been proposed that the presence of hosts that support tick feeding but not pathogen multiplication may dilute the transmission of the pathogen. However, models need to consider the spatial component to adequately explain how hosts, ticks and pathogens are distributed into the landscape

    Search for low-mass WIMPs in a 0.6 kg day exposure of the DAMIC experiment at SNOLAB

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    We present results of a dark matter search performed with a 0.6 kg day exposure of the DAMIC experiment at the SNOLAB underground laboratory. We measure the energy spectrum of ionization events in the bulk silicon of charge-coupled devices down to a signal of 60 eV electron equivalent. The data are consistent with radiogenic backgrounds, and constraints on the spin-independent WIMP-nucleon elastic-scattering cross section are accordingly placed. A region of parameter space relevant to the potential signal from the CDMS-II Si experiment is excluded using the same target for the first time. This result obtained with a limited exposure demonstrates the potential to explore the low-mass WIMP region (<10 GeV/c2c^{2}) of the upcoming DAMIC100, a 100 g detector currently being installed in SNOLAB.Comment: 11 pages, 11 figure

    A novel combined scientific and artistic approach for the advanced characterization of interactomes: The akirin/subolesin model

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    The main objective of this study was to propose a novel methodology to approach challenges in molecular biology. Akirin/Subolesin (AKR/SUB) are vaccine protective antigens and are a model for the study of the interactome due to its conserved function in the regulation of different biological processes such as immunity and development throughout the metazoan. Herein, three visual artists and a music professor collaborated with scientists for the functional characterization of the AKR2 interactome in the regulation of the NF-¿B pathway in human placenta cells. The results served as a methodological proof-of-concept to advance this research area. The results showed new perspectives on unexplored characteristics of AKR2 with functional implications. These results included protein dimerization, the physical interactions with different proteins simultaneously to regulate various biological processes defined by cell type-specific AKR– protein interactions, and how these interactions positively or negatively regulate the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-¿B) signaling pathway in a biological context-dependent manner. These results suggested that AKR2-interacting proteins might constitute suitable secondary transcription factors for cell-and stimulus-specific regulation of NF-¿B. Musical perspective supported AKR/SUB evolutionary conservation in different species and provided new mechanistic insights into the AKR2 interactome. The combined scientific and artistic perspectives resulted in a multidisciplinary approach, advancing our knowledge on AKR/SUB interactome, and provided new insights into the function of AKR2–protein interactions in the regulation of the NF-¿B pathway. Additionally, herein we proposed an algorithm for quantum vaccinomics by focusing on the model proteins AKR/SUB. © 2020 by the authors. Licensee MDPI, Basel, Switzerland

    Comparative study of the use of Doxycycline and Oxytetracycline to treat Anaplasmosis in fattening lambss

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    Lamb icteric carcasses condemnation due to Anaplasma ovis is causing relevant economic losses. A comparative study was developed on the effects of different antibiotics to treat ovine anaplasmosis in fattening lambs. A total of 100 A. ovis naturally infected lambs were selected and randomly divided into four groups of 25 lambs: Group ID, treated with injectable doxycycline; Group OD, oral doxycycline; Group O, injectable oxytetracycline; and Group C, untreated animals for the control group. Clinical, haematological, and molecular analyses were performed before the treatment and 12 and 45 days after the beginning of the treatments, and carcass condemnation was followed after slaughter. The A. ovis bacterial load was high before the treatments in the four groups and decreased significantly 45 days after treatment in the ID and O Groups (p &lt; 0.001). The parameters that were related to haemolysis showed similar results. At the abattoir, 15 out of the 47 examined carcasses were condemned; 7 of C Group, 6 of OD Group, 2 of O Group, and 0 of ID Group. It can be concluded that injectable doxycycline and oxytetracycline significantly reduce A. ovis bacterial load in blood and carcass condemnation at the abattoir. Further studies are needed in order to confirm these encouraging findings
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