931 resultados para Aristarchus, of Samothrace, ca. 217-145 B.C.
Resumo:
Samples of cultivated Ulva clathrata were collected from a medium scale system (MSS, 1.5 1.5 m tank), or from a large scale system (LSS, 0.8 ha earthen pond). MSS samples were dried directly while the LSS sample was washed in freshwater and pressed before drying. Crude protein content ranged 20–26%, essential amino acids accounting for 32–36% of crude protein. The main analysed monosaccharides were rhamnose (36–40%), uronic acids (27–29%), xylose (10–13%) and glucose (10–16%). Some notable variations between MSS and LSS samples were observed for total dietary fibre (26% vs 41%), saturated fatty acids (31% vs 51%), PUFAS (33% vs 13%), carotenoids (358 vs 169 mg kg1 dw) and for Ca (9 vs 19 g kg1 ), Fe (0.6 vs 4.2 g kg1 ), Cu (44 vs 14 mg kg1 ), Zn (93 vs 17 mg kg1 ) and As (2 vs 9 mg kg1 ). The chemical composition of U. clathrata indicates that it has a good potential for its use in human and animal food.
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Cette recherche vise à décrire les liens entre les représentations des enfants dans deux systèmes d’écriture: alphabétique et consonantique. Cette étude transversale est déployée auprès de 60 enfants libanais âgés entre 4 et 6 ans. Les écritures des enfants autour de huit mots sont récoltées en français et en arabe. Les résultats ne montrent aucune différence significative entre les deux systèmes d’écriture aux âges de 4 et 5 ans. C’est à l’âge de 6 ans que des différences significatives se présentent entre les deux langues. Les résultats montrent une différence significative des écritures en fonction de l’âge. Ces résultats soutiennent l’hypothèse développementale d’une structuration unique inductive quant aux codes alphabétique français et consonantique arabe. Cette structuration se distingue pour chacune des langues lors de l’entrée formelle dans l’écrit. Descripteurs: 1- émergence, 2- littératie, 3- écriture provisoire, 4- français, 5- arabe
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This thesis concerns the analysis of the socio-economic transformation of communities in Bronze Age southwestern Cyprus. Through the adoption of a dialectical perspective of analysis, individuals and environment are considered part of the same unity: they are cooperating agents in shaping society and culture. The Bronze Age is a period of intense transformation in the organization of local communities, made of a continuous renegotiation of the socio-economic roles and interactions. The archaeological record from this portion of the island allows one to go beyond the investigation of the complex and articulated transition from the EBA-MBA agro-pastoral and self-sufficient communities to the LBA centralized and trade-oriented urban-centres. Through a shifting of analytical scales, the emerging picture suggests major transformations in the individual-community-territory dialectical relations. A profound change in the materials conditions of social life, as well as in the superstructural realm, was particularly entailed by the dissolution of the relation to the earth, due to the emergence of new forms of land exploitation/ownership and to the shift of the settlement pattern in previously unknown areas. One of the key points of this thesis is the methodological challenge of working with legacy survey data as I re-analysed a diverse archaeological legacy, which is the result of more than fifty years of survey projects, rescue and research-oriented excavations, as well as casual discoveries. Source critique and data evaluation are essential requirements in an integrative and cross-disciplinary regional perspective, in the comprehensive processing of heterogeneous archaeological and environmental datasets. Through the estimation of data precision and certainty, I developed an effective - but simple - method to critically evaluate existing datasets and to inter-correlate them without losing their original complexity. This powerful method for data integration can be applied to similar datasets belonging to other regions and other periods as it originates from the evaluation of larger methodological and theoretical issues that are not limited to my spatial and temporal focus. As I argue in this thesis, diverse archaeological legacies can be efficiently re-analysed through an integrative and regional methodology. The adoption of a regional scale of analysis can provide an excellent perspective on the complexity of transformations in ancient societies, thus creating a fundamental bridge between the local stories and grand landscape narratives.
Resumo:
Raman spectroscopy has been used to study the arsenate minerals haidingerite Ca(AsO3OH)•H2O and brassite Mg(AsO3OH)•4H2O. Intense Raman bands in haidingerite spectrum observed at 745 and 855 cm-1 are assigned to the (AsO3OH)2- ν3 antisymmetric stretching and ν1 symmetric stretching vibrational modes. For brassite two similarly assigned intense bands are found at 809 and 862 cm-1. The observation of multiple Raman bands in the (AsO3OH)2- stretching and bending regions suggests that the arsenate tetrahedrons in the crystal structures of both minerals studied are strongly distorted. Broad Raman bands observed at 2842 cm-1 for haidingerite and 3035 cm-1 for brassite indicate strong hydrogen bonding of water molecules in the structure of these minerals. OH…O hydrogen bond lengths were calculated from the Raman spectra based on empiric relations.
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The relationship between soil structure and the ability of soil to stabilize soil organic matter (SOM) is a key element in soil C dynamics that has either been overlooked or treated in a cursory fashion when developing SOM models. The purpose of this paper is to review current knowledge of SOM dynamics within the framework of a newly proposed soil C saturation concept. Initially, we distinguish SOM that is protected against decomposition by various mechanisms from that which is not protected from decomposition. Methods of quantification and characteristics of three SOM pools defined as protected are discussed. Soil organic matter can be: (1) physically stabilized, or protected from decomposition, through microaggregation, or (2) intimate association with silt and clay particles, and (3) can be biochemically stabilized through the formation of recalcitrant SOM compounds. In addition to behavior of each SOM pool, we discuss implications of changes in land management on processes by which SOM compounds undergo protection and release. The characteristics and responses to changes in land use or land management are described for the light fraction (LF) and particulate organic matter (POM). We defined the LF and POM not occluded within microaggregates (53-250 mum sized aggregates as unprotected. Our conclusions are illustrated in a new conceptual SOM model that differs from most SOM models in that the model state variables are measurable SOM pools. We suggest that physicochemical characteristics inherent to soils define the maximum protective capacity of these pools, which limits increases in SOM (i.e. C sequestration) with increased organic residue inputs.
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The development of new materials for water purification is of universal importance. Among these types of materials are layered double hydroxides (LDHs). Non-ionic materials pose a significant problem as pollutants. The interaction of methyl orange (MO) and acidic scarlet GR (GR) adsorption on hydrocalumite (Ca/Al-LDH-Cl) were studied by X-ray diffraction (XRD), infrared spectroscopy (MIR), scanning electron microscope (SEM) and near-infrared spectroscopy (NIR). The XRD results revealed that the basal spacing of Ca/Al-LDH-MO was expanded to 2.45 nm, and the MO molecules were intercalated with a inter-penetrating bilayer model in the gallery of LDH, with 49o tilting angle. Yet Ca/Al-LDH-GR was kept the same d-value as Ca/Al-LDH-Cl. The NIR spectrum for Ca/Al-LDH-MO showed a prominent band around 5994 cm-1, assigned to the combination result of the N-H stretching vibrations, which was considered as a mark to assess MO- ion intercalation into Ca/Al-LDH-Cl interlayers. From SEM images, the particle morphology of Ca/Al-LDH-MO mainly changed to irregular platelets, with a “honey-comb” like structure. Yet the Ca/Al-LDH-GR maintained regular hexagons platelets, which was similar to that of Ca/Al-LDH-Cl. All results indicated that MO- ion was intercalated into Ca/Al-LDH-Cl interlayers, and acidic scarlet GR was only adsorped upon Ca/Al-LDH-Cl surfaces.
Resumo:
The purpose of this study was to investigate the effects of whole-body cryotherapy (WBC) on proprioceptive function, muscle force recovery following eccentric muscle contractions and tympanic temperature (TTY). Thirty-six subjects were randomly assigned to a group receiving two 3-min treatments of −110 ± 3 °C or 15 ± 3 °C. Knee joint position sense (JPS), maximal voluntary isometric contraction (MVIC) of the knee extensors, force proprioception and TTY were recorded before, immediately after the exposure and again 15 min later. A convenience sample of 18 subjects also underwent an eccentric exercise protocol on their contralateral left leg 24 h before exposure. MVIC (left knee), peak power output (PPO) during a repeated sprint on a cycle ergometer and muscles soreness were measured pre-, 24, 48 and 72 h post-treatment. WBC reduced TTY, by 0.3 °C, when compared with the control group (P<0.001). However, JPS, MVIC or force proprioception was not affected. Similarly, WBC did not effect MVIC, PPO or muscle soreness following eccentric exercise. WBC, administered 24 h after eccentric exercise, is ineffective in alleviating muscle soreness or enhancing muscle force recovery. The results of this study also indicate no increased risk of proprioceptive-related injury following WBC.
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Objectives: To evaluate the clinical value of pre-operative serum CA125 in predicting the presence of extra-uterine disease in patients with apparent early stage endometrial cancer. Methods: Between October 6, 2005 and June 17, 2010, 760 patients were enrolled in an international, multicentre, prospective randomized trial (LACE) comparing laparotomy with laparoscopy in the management of endometrial cancer apparently confined to the uterus. This study is based on data from 657 patients with endometrial adenocarcinoma who had a pre-operative serum CA125 value, and was undertaken to correlate pre-operative serum CA125 with final stage. Results: Using a pre-operative CA-125 cutpoint of 30U/ml was associated with the smallest misclassification error (14.5%) using a multiple cross-validation method. Median pre-operative serum CA-125 was 14U/ml, and using a cutpoint of 30U/ml, 14.9% of patients had elevated CA-125 levels. Of 98 patients with elevated CA-125 level, 36 (36.7%) had evidence of extra-uterine disease. Of the 116 patients (17.7%) with evidence of extra-uterine disease, 31.0% had elevated CA-125 level. In univariate and multivariate logistic regression analysis, only pre-operative CA-125 level was found to be associated with extra-uterine spread of disease. Utilising a cutpoint of 30U/ml achieved a sensitivity, specificity, positive predictive value and negative predictive value of 31.0%, 88.5%, 36.7% and 85.7% respectively. Overall, 326/657 (49.6%) of patients had full surgical staging involving lymph node dissection. When analysis was limited to patients that had undergone full surgical staging, the outcomes remained essentially unchanged. Conclusions: Elevated CA-125 above 30U/ml in patients with apparent early stage disease is associated with a sensitivity of 31.0% and specificity of 88.5% in detecting extra-uterine disease. Pre-operative identification of this risk factor may assist to triage patients to tertiary centres and comprehensive surgical staging.
Resumo:
Epstein Barr virus (EBV) is a common γ-herpes virus, infecting approximately 90% of the world‟s population. It is also one of the first known viruses known to be oncogenic, and is associated with a number of tumour types, primarily lymphomas. MicroRNAs (miRNAs) are post-transcriptional regulators of gene expression and many human miRNAs have been associated with the development of malignancies including cancer. EBV was the first human virus identified to express miRNAs and encodes more than 40 miRNAs within its genome. Yet, an understanding of the targets of EBV-miRNAs, and thereby the function of them in pathogenesis remains sadly limited. This study identifies a potential novel target of EBV-miRNAs, MECP2 and characterises the miRNA:mRNA interactions between two previously identified novel targets; Bim and EBF1. In particular, this study focuses upon the interaction between EBF1 and the EBV-miRNA BART11-5p, demonstrating a 151bp region of the EBF1 3‟UTR that is capable of mediating the silencing of luciferase expression by BART11-5p but is not capable of silencing a full length EBF1-3‟UTR luciferase construct. This study provides evidence that EBF1 may be a target of one or more EBV-miRNAs.