26 research outputs found

    Development of a measurement platformon a light airplane and analysis of airborne measurementsin the atmospheric boundary layer

    Get PDF
    In the present paper we provide an overview of a long term research project aimed at setting up a suitable platform for measurements in the atmospheric boundary layer on a light airplane along with some preliminary results obtained from fi eld campaigns at selected sites. Measurements of air pressure, temperature and relative humidity have been performed in various Alpine valleys up to a height of about 2500 m a.m.s.l. By means of GPS resources and specifi c post-processing procedures careful positioning of measurement points within the explored domain has been achieved. The analysis of collected data allowed detailed investigation of atmospheric vertical structures and dynamics typical of valley environment, such as morning transition from ground based inversion to fully developed well mixed convective boundary layer. Based on data collected along fl ights, 3D fi elds of the explored variables have been detected and identifi ed through application of geostatistical techniques (Kriging). The adopted procedures allowed evaluation of the intrinsic statistical structure of the spatial distribution of measured quantities and the estimate of the values of the same variable at unexplored locations by suitable weighted average of data recorded at close locations. Results thus obtained are presented and discussed

    Development of a measurement platformon a light airplane and analysis of airborne measurementsin the atmospheric boundary layer

    Get PDF
    In the present paper we provide an overview of a long term research project aimed at setting up a suitable platform for measurements in the atmospheric boundary layer on a light airplane along with some preliminary results obtained from fi eld campaigns at selected sites. Measurements of air pressure, temperature and relative humidity have been performed in various Alpine valleys up to a height of about 2500 m a.m.s.l. By means of GPS resources and specifi c post-processing procedures careful positioning of measurement points within the explored domain has been achieved. The analysis of collected data allowed detailed investigation of atmospheric vertical structures and dynamics typical of valley environment, such as morning transition from ground based inversion to fully developed well mixed convective boundary layer. Based on data collected along fl ights, 3D fi elds of the explored variables have been detected and identifi ed through application of geostatistical techniques (Kriging). The adopted procedures allowed evaluation of the intrinsic statistical structure of the spatial distribution of measured quantities and the estimate of the values of the same variable at unexplored locations by suitable weighted average of data recorded at close locations. Results thus obtained are presented and discussed

    Doing archaeology and working with Amazonian communities: the case of the earthen structures known as geoglyphs

    Get PDF
    The project of study of earthen structures known as geoglyphs led by the universities of Valencia (Spain) and the Federal University of Acre (Rio Branco, Brazil) has different objectives but the main one, beyond, the study of the structures is the implementation of plans that allow the necessary protection of these monuments having an impact on local communities. The project pretends to move away from interventions that could be labeled as ‘neocolonialist’ and contribute to the development of archaeological activity in the state of Acre. For this, it has the collaboration of the Acrean delegation of the Instituto de Patrimonio Histórico Artístico (IPHAN), la fundación Elías Mansur de Cultura e Comunicação and institutions of great social relevance as the In- stituto Chico Mendes de Conservação da Biodiversidade (ICMBIO) and the Empresa Brasileira de Pesquisa Agropecuària (EMBRAPA). The study of the geoglyphs, paradoxically, has been possible due to the deforestation of the Amazon rainforest with absolute con- tempt of the local communities, both indigenous and rubber workers (serengueiros). The sustainable development of these com- munities implies a management of the extractive reserves, mainly of the Chico Mendes one, and to that sustainable development it intends to contribute the integral study of the earthen structures known as geogplyphs. The extraordinary dimension of the phe- nomenon, more than 500 structures in the state of Acre (more than 150000 km2 of mainly forested surface) makes its conserva- tion very complicated if local communities are not involved. From the archaeological point of view, the necessary excavations have to weigh the sustainability of the project and plan activities of protection.The project of study of earthen structures known as geoglyphs led by the universities of Valencia (Spain) and the Federal University of Acre (Rio Branco, Brazil) has different objectives but the main one, beyond, the study of the structures is the implementation of plans that allow the necessary protection of these monuments having an impact on local communities. The project pretends to move away from interventions that could be labeled as ‘neocolonialist’ and contribute to the development of archaeological activity in the state of Acre. For this, it has the collaboration of the Acrean delegation of the Instituto de Patrimonio Histórico Artístico (IPHAN), la fundación Elías Mansur de Cultura e Comunicação and institutions of great social relevance as the In- stituto Chico Mendes de Conservação da Biodiversidade (ICMBIO) and the Empresa Brasileira de Pesquisa Agropecuària (EMBRAPA). The study of the geoglyphs, paradoxically, has been possible due to the deforestation of the Amazon rainforest with absolute con- tempt of the local communities, both indigenous and rubber workers (serengueiros). The sustainable development of these com- munities implies a management of the extractive reserves, mainly of the Chico Mendes one, and to that sustainable development it intends to contribute the integral study of the earthen structures known as geogplyphs. The extraordinary dimension of the phe- nomenon, more than 500 structures in the state of Acre (more than 150000 km2 of mainly forested surface) makes its conserva- tion very complicated if local communities are not involved. From the archaeological point of view, the necessary excavations have to weigh the sustainability of the project and plan activities of protection

    A Importância de se estudar os sitios arqueológicos nas escolas: o caso dos geoglifos no Acre

    Get PDF
    No Estado do Acre foram encontrados centenas de sítios arqueológicos que estão, a cada dia, ganhando mais importância. Conhecidos como Geoglifos, trata-se de estruturas de terra delimitadas por valetas que formam estruturas de grande tamanho e de diversas formas geométricas. Dada sua importância, este trabalho apresenta um relato de experiência obtida a partir do projeto 'Conhecendo os Geoglifos do Acre', que nasce da necessidade de divulgação do conhecimento acerca das estruturas de terra delimitadas por valetas encontradas na região da Amazônia Sul Ocidental, tendo sido aplicado na terceira edição da feira Viver Ciência, que aconteceu em Rio Branco, Acre, entre os dias 19 a 21 de setembro de 2017. O projeto visou a construção de uma maquete, associada à exposição imagens e explicações dialogadas no decorrer do evento, levantando problemáticas e dispersando conhecimentos para a valorização da cultura e educação patrimonial na região. Como objetivo principal, figurou a divulgação dos conhecimentos que já se têm sobre os Geoglifos aos professores e alunos que visitaram a feira, esperando contribuir com o desenvolvimento dos estudos arqueológicos no Estado

    Levothyroxine use and the risk of colorectal cancer: a large population-based case–control study

    Get PDF
    Objective: Whether an association between oral levothyroxine use, leading to supraphysiological exposure of the colon to thyroid hormones, and risk of colorectal cancer exists in humans is unclear. We therefore aimed to assess whether the use of levothyroxine is associated with a reduced risk of colorectal cancer in a linked cohort of pharmacy and cancer data. Design: Population-based matched case–control study. Methods: A total of 28,121 patients diagnosed with colorectal cancer between 1998 and 2014 were matched to 106,086 controls. Multivariable logistic regression was used to estimate the association between levothyroxine use and occurrence of colorectal cancer, adjusted for potential confounders. Results were stratified by gender, age, tumour subtype, and staging, as well as treatment duration and dosing. Results: A total of 1066 colorectal cancer patients (4%) and 4024 (4%) controls had used levothyroxine at any point before index date (adjusted odds ratio 0.95 (0.88–1.01)). Long-term use of levothyroxine was seen in 323 (30%) colorectal cancer patients and 1111 (28%) controls (adjusted odds ratio 1.00 (0.88–1.13)). Stratification by tumour subsite showed a borderline significant risk reduction of rectal cancer, while this was not seen for proximal colon cancer or distal colon cancer. There was no relationship with treatment duration or with levothyroxine dose. Conclusions: In this study, no reduced risk of colorectal cancer was seen in levothyroxine users. When stratifying by tumour subsite, a borderline significant risk reduction of rectal cancer was found and may warrant further research

    Interactions between the night time valley-wind system and a developing cold-air pool

    Get PDF
    This is a pre-copyedited, author-produced PDF of an article accepted for publication in Boundary-Layer Meteorology following peer review. The version of record [Arduini, G., Staquet, C & Chemel, C., ‘Interactions between the night time valley-wind system and a developing cold-air pool’, Boundary-Layer Meteorol (2016) 161:1 (49-72), first published online June 2, 2016, is available at Springer online at doi: 10.1007/s10546-016-0155-8The Weather Research and Forecast (WRF) numerical model is used to characterize the influence of a thermally-driven down-valley flow on a developing cold-air pool in an idealized alpine valley decoupled from the atmosphere above. Results for a three-dimensional (3D) valley, which allows for the formation of a down-valley flow, and for a two-dimensional (2D) valley, where the formation of a down-valley flow is inhibited, are analyzed and compared. A key result is that advection leads to a net cooling in the 2D valley and to a warming in the 3D valley, once the down-valley flow is fully developed. This difference stems from the suppression of the slope-flow induced upward motions over the valley centre in the 3D valley. As a result, the downslope flows develop a cross-valley circulation within the cold-air pool, the growth of the cold-air pool is reduced and the valley atmosphere is generally warmer than in the 2D valley. A quasi-steady state is reached for which the divergence of the down-valley flow along the valley is balanced by the convergence of the downslope flows at the top of the cold-air pool, with no net contribution of subsiding motions far from the slope layer. More precisely, the inflow of air at the top of the cold-air pool is found to be driven by an interplay between the return flow from the plain region and subsidence over the plateaux. Finally, the mechanisms that control the structure of the cold-air pool and its evolution are found to be independent of the valley length as soon as the quasi-steady state is reached and the down-valley flow is fully developed.Peer reviewedFinal Accepted Versio

    Duodenal Anaerobutyricum soehngenii infusion stimulates GLP-1 production, ameliorates glycaemic control and beneficially shapes the duodenal transcriptome in metabolic syndrome subjects : a randomised double-blind placebo-controlled cross-over study

    Get PDF
    Objective Although gut dysbiosis is increasingly recognised as a pathophysiological component of metabolic syndrome (MetS), the role and mode of action of specific gut microbes in metabolic health remain elusive. Previously, we identified the commensal butyrogenic Anaerobutyricum soehngenii to be associated with improved insulin sensitivity in subjects with MetS. In this proof-of-concept study, we investigated the potential therapeutic effects of A. soehngenii L2-7 on systemic metabolic responses and duodenal transcriptome profiles in individuals with MetS. Design In this randomised double-blind placebo-controlled cross-over study, 12 male subjects with MetS received duodenal infusions of A. soehngenii/ placebo and underwent duodenal biopsies, mixed meal tests (6 hours postinfusion) and 24-hour continuous glucose monitoring. Results A. soehngenii treatment provoked a markedly increased postprandial excursion of the insulinotropic hormone glucagon-like peptide 1 (GLP-1) and an elevation of plasma secondary bile acids, which were positively associated with GLP-1 levels. Moreover, A. soehngenii treatment robustly shaped the duodenal expression of 73 genes, with the highest fold induction in the expression of regenerating islet-protein 1B (REG1B)-encoding gene. Strikingly, duodenal REG1B expression positively correlated with GLP-1 levels and negatively correlated with peripheral glucose variability, which was significantly diminished in the 24 hours following A. soehngenii intake. Mechanistically, Reg1B expression is induced upon sensing butyrate or bacterial peptidoglycan. Importantly, A. soehngenii duodenal administration was safe and well tolerated. Conclusions A single dose of A. soehngenii improves peripheral glycaemic control within 24 hours; it specifically stimulates intestinal GLP-1 production and REG1B expression. Further studies are needed to delineate the specific pathways involved in REG1B induction and function in insulin sensitivity.Peer reviewe

    AIM2 in regulatory T cells restrains autoimmune diseases

    Get PDF
    The inflammasome initiates innate defence and inflammatory responses by activating caspase-1 and pyroptotic cell death in myeloid cells1,2. It consists of an innate immune receptor/sensor, pro-caspase-1, and a common adaptor molecule, ASC. Consistent with their pro-inflammatory function, caspase-1, ASC and the inflammasome component NLRP3 exacerbate autoimmunity during experimental autoimmune encephalomyelitis by enhancing the secretion of IL-1β and IL-18 in myeloid cells3–6. Here we show that the DNA-binding inflammasome receptor AIM27–10 has a T cell-intrinsic and inflammasome-independent role in the function of T regulatory (Treg) cells. AIM2 is highly expressed by both human and mouse Treg cells, is induced by TGFβ, and its promoter is occupied by transcription factors that are associated with Treg cells such as RUNX1, ETS1, BCL11B and CREB. RNA sequencing, biochemical and metabolic analyses demonstrated that AIM2 attenuates AKT phosphorylation, mTOR and MYC signalling, and glycolysis, but promotes oxidative phosphorylation of lipids in Treg cells. Mechanistically, AIM2 interacts with the RACK1–PP2A phosphatase complex to restrain AKT phosphorylation. Lineage-tracing analysis demonstrates that AIM2 promotes the stability of Treg cells during inflammation. Although AIM2 is generally accepted as an inflammasome effector in myeloid cells, our results demonstrate a T cell-intrinsic role of AIM2 in restraining autoimmunity by reducing AKT–mTOR signalling and altering immune metabolism to enhance the stability of Treg cells

    925 NOTES AND CORRESPONDENCE A Method to Determine the Capping Inversion of the Convective Boundary Layer

    No full text
    ABSTRACT A simple mathematical algorithm is proposed to decipher the thermal structure of the convective boundary layer by means of best-fit analysis of soundings or airborne measurements with a smooth ideal profile. The latter includes a constant-potential-temperature mixed layer, a strongly stratified entrainment layer, and a constantlapse-rate free atmosphere. The resulting profile depends on five parameters amenable, through simple mathematical relationships, to physical variables defining the vertical structure of the layers. The method allows objective evaluation of parameters involved in the test profile and easy comparison of measurements with theoretically expected structure
    corecore