3,098 research outputs found

    On the orientation of two roman towns in the rhine area

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    The aim of the present paper is to extend the archeoastronomical study sample on the orientation of Roman cities to the analysis of a number of cases in the Rhine area. The starting point is a study of the orientation of Augusta Treverorum (present day Trier; Goethert, 2003). Goethert assumed that the orientation of the decumanus maximus was towards sunrise at the autumn equinox, on September 23rd as the dies natalis of the city. This event would deliberately coincide with the anniversary of the birth of Augustus, and would have determined the establishment and orientation of the new urban layout. However, our in situ measurements of the orientation of the urban network at several sites of the Roman town rule out this hypothesis. We find an orientation that is more in line with those documented for other Roman cities and camps elsewhere in the Roman provinces (González-García et al., 2014; Rodríguez-Antón et al., 2016). Moreover, measurements made in the Lenus Mars temple indicate a recurrent phenomenon of cultural hybridization. Here the temple, located outside the city walls on the west bank of the river Moselle, combines a possibly Celtic orientation with Roman symbolic beliefs. In reality, the alleged orientation towards the dies natalis of Augustus is verified for Cologne. There are a number of circumstances that make this choice logical for a city that was initially planned as the capital of the Augustan province of Germania and the seat of an ara of imperial worshipS

    Microvillous inclusion disease as a cause of severe congenital diarrhea. Case report

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    Indexación: Scopus; Scielo.Introducción: Las diarreas congénitas son patologías graves de baja frecuencia y alta mortalidad. Se manifiestan durante los primeros días o meses de vida con severa diarrea, generando insuficiencia intestinal y dependencia de nutrición parenteral. Se debe sospechar ante un recién nacido o lactante con pérdidas masivas hidroelectrolíticas, y se diagnostican utilizando parámetros clínicos, endoscópicos, histológicos y eventualmente genéticos. El tratamiento es de soporte, con reposición hidroelectrolítica intensa y nutricional. Objetivo: Presentar un caso de diarrea congénita, identificada como Enfermedad por Inclusión Microvellositaria, de presentación neonatal. Caso clínico: Paciente varón edad actual 3 años, hijo de padres consanguíneos, quien debutó a los 10 días de vida con diarrea secretora severa, requiriendo ingreso a unidad de paciente crítico y nutrición parenteral permanente. Inicialmente además con síndrome de Fanconi, que luego se recupera. Se confirmó la sospecha de Enfermedad de Inclusión Microvellositaria utilizando microscopia óptica, electrónica e inmunohistoquímica. Se obtuvo una favorable evolución utilizando nutrición parenteral total (NPT) a domicilio. Conclusiones: Se presenta el primer caso conocido en Chile de un paciente con diarrea congénita por inclusión microvellositaria manejado y su evolución.https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0370-41062017000500015&lng=en&nrm=iso&tlng=es&ORIGINALLANG=e

    Modular analysis of the control of flagellar Ca2+-spike trains produced by CatSper and CaV channels in sea urchin sperm

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    Intracellular calcium ([Ca2+]i) is a basic and ubiquitous cellular signal controlling a wide variety of biological processes. A remarkable example is the steering of sea urchin spermatozoa towards the conspecific egg by a spatially and temporally orchestrated series of [Ca2+]i spikes. Although this process has been an experimental paradigm for reproduction and sperm chemotaxis studies, the composition and regulation of the signalling network underlying the cytosolic calcium fluctuations are hitherto not fully understood. Here, we used a differential equations model of the signalling network to assess which set of channels can explain the characteristic envelope and temporal organisation of the [Ca2+]i-spike trains. The signalling network comprises an initial membrane hyperpolarisation produced by an Upstream module triggered by the egg-released chemoattractant peptide, via receptor activation, cGMP synthesis and decay. Followed by downstream modules leading to intraflagellar pH (pHi), voltage and [Ca2+]i fluctuations. The Upstream module outputs were fitted to kinetic data on cGMP activity and early membrane potential changes measured in bulk cell populations. Two candidate modules featuring voltage-dependent Ca2+-channels link these outputs to the downstream dynamics and can independently explain the typical decaying envelope and the progressive spacing of the spikes. In the first module, [Ca2+]i-spike trains require the concerted action of a classical CaV-like channel and a potassium channel, BK (Slo1), whereas the second module relies on pHi-dependent CatSper dynamics articulated with voltage-dependent neutral sodium-proton exchanger (NHE). We analysed the dynamics of these two modules alone and in mixed scenarios. We show that the [Ca2+]i dynamics observed experimentally after sustained alkalinisation can be reproduced by a model featuring the CatSper and NHE module but not by those including the pH-independent CaV and BK module or proportionate mixed scenarios. We conclude in favour of the module containing CatSper and NHE and highlight experimentally testable predictions that would corroborate this conclusion

    Effects of hydrogen and primary air in a commercial partially-premixed atmospheric gas burner by means of optical and supervised machine learning techniques

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    In order to ascertain the effects of the hydrogen addition and the primary air-fuel ratio on burner performance and emissions, we conduct tests on a commercial atmospheric gas burner using pure methane and a blend of hydrogen/methane. Relevant statistical image features are extracted from a UV–VIS camera equipped with narrow-band optical filters. Radical image results agrees with spectrometric data, showing the relevance of the OH* intensity radiation coming from the outer non-premixed zone. The double-cone flame structure is evident, showing a growing secondary non-premixed cone as the primary air-fuel ratio is decreased. In addition, the direct relationship found between flame radical imaging features and NOx emissions has been used to develop a predictive model by integrating classification techniques and neural networks. The research confirms UV–VIS chemiluminescence imaging techniques as powerful tools aimed at combustion monitoring, with huge prospects of being integrated within advanced emission control techniques for commercial burners

    Optical analysis of blast furnace gas combustion in a laboratory premixed burner

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    The use of blast furnace gas (BFG) as a fuel provides an alternative for waste stream valorization in the steel industry, enhancing the sustainability and decarbonization of its processes. Nevertheless, the implementation of this solution on an industrial scale requires a continuous control of the combustion due to the low calorific value of BFG. This work analyzes the combustion behavior and monitoring of BFG/CH4blends in a laboratory premixed fuel burner. We evaluate several stable combustion conditions by burning different BFG/CH4mixtures at a constant power rate over a wide range of air/fuel equivalence ratios. In addition, relevant image features and chemiluminescence emission spectra have been extracted from flames, using advanced optical devices. BFG combustion causes an increase in CO2and CO emissions, since those fuels are the main fuel components of the mixture. On the other hand, NOxemissions decreased because of the low temperature of combustion of the BFG and its mixtures. Chemiluminescence shows that, in the case of CH4combustion, peaks associated with hydrocarbons are present, while during the substitution of CH4by BFG those peaks are attenuated. Image flame features extracted from both ultraviolet and visible bandwidths show a correlation with the fuel blend and air/fuel equivalence ratio. In the end, methodologies developed in this work have been proven to be valuable alternatives with a high potential for the monitoring and control of BFG cofiring for the steel industry
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