203 research outputs found

    Nuevos métodos de tintura en frio para lana.

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    Este trabajo se inició como un estudio de la influencia de la urea en el proceso de tintura. Se investigaron los efectos de la urea sobre fibras y colorantes, teniendo presente sus dos posibles factores. 1. Las soluciones de urea hinchan la lana permitiendo el fácil acceso del colorante. 2. La urea dispersa y disgrega el colorante permitiendo un acceso más facil de las especies monomoleculares.Peer Reviewe

    Pathobiology of ALK-negative anaplastic large cell lymphoma

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    The authors revise the concept of ALK-negative anaplastic large cell lymphoma (ALCL) in the light of the recently updated WHO classification of Tumors of Hematopoietic and Lymphoid Tissues both on biological and clinical grounds. The main histological findings are illustrated as well as the phenotypic, molecular and clinical characteristics. Finally, the biological rationale for possible innovative targeted therapies is presented

    Structure and Function of Stony Coral Intraskeletal Polysaccharides

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    Polysaccharides represent a main weight fraction of the intraskeletal organic matrix of corals, but their structure, as well as their function in the calcification process, has been poorly investigated. This communication shows by a combination of techniques (nuclear magnetic resonance, Fourier transform infrared, and monosaccharide composition) that their key component is a 1\u21923 \u3b2-d glucuronic acid polymer and evidences its influence in vitro in the calcification process

    Multiscale analysis on otolith structural features reveals differences in ontogenesis and sex in Merluccius merluccius in the western Adriatic Sea

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    Otolith biomineralization results from biochemical processes regulated by the interaction of internal (physiological) and external (environmental) factors which lead to morphological and ultrastructural variability at intra- and interspecific levels. The aim of this study was to conduct a multi-scale analysis of the sagittal otoliths of the Merlucius merlucius (European hake) from the western Adriatic Sea in order to correlate otolith features with fish ontogeny and sex. We show that otoliths of sexually undifferentiated (non-sexed) individuals having a fish body total length (TL) less than 15 cm had faster growth in length, width, area, perimeter, volume and weight and a higher amount of organic matrix compared with otoliths of sexually differentiated individuals (females and males) having a fish size range of 15-50 cm. Most importantly, with increasing fish TL, female saccular otoliths contained a higher number of protuberances and rougher surface compared with male specimens, which showed more uniform mean curvature density. The differences between females and males discovered in this study could be associated with fish hearing adaptation to reproductive behavioural strategies during the spawning season. The outcomes of this research provide insights on how size and sex-related variations in otolith features may be affected by fish ecological and behavioural patterns

    Gains and losses of coral skeletal porosity changes with ocean acidification acclimation

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    Ocean acidi\ufb01cation is predicted to impact ecosystems reliant on calcifying organisms, potentially reducing the socioeconomic bene\ufb01ts these habitats provide. Here we investigate the acclimation potential of stony corals living along a pH gradient caused by a Mediterranean CO2 vent that serves as a natural long-term experimental setting. We show that in response to reduced skeletal mineralization at lower pH, corals increase their skeletal macroporosity (features >10 micrometers) in order to maintain constant linear extension rate, an important criterion for reproductive output. At the nanoscale, the coral skeleton\u2019s structural features are not altered. However, higher skeletal porosity, and reduced bulk density and stiffness may contribute to reduce population density and increase damage susceptibility under low pH conditions. Based on these observations, the almost universally employed measure of coral biomineralization, the rate of linear extension, might not be a reliable metric for assessing coral health and resilience in a warming and acidifying ocean

    Linking Internal Carbonate Chemistry Regulation and Calcification in Corals Growing at a Mediterranean CO2 Vent

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    Corals exert a strong biological control over their calcification processes, but there is a lack of knowledge on their capability of long-term acclimatization to ocean acidification (OA). We used a dual geochemical proxy approach to estimate the calcifying fluid pH (pHcf) and carbonate chemistry of a Mediterranean coral (Balanophyllia europaea) naturally growing along a pH gradient (range: pHTS 8.07–7.74). The pHcf derived from skeletal boron isotopic composition (δ11B) was 0.3–0.6 units above seawater values and homogeneous along the gradient (mean ± SEM: Site 1 = 8.39 ± 0.03, Site 2 = 8.34 ± 0.03, Site 3 = 8.34 ± 0.02). Also carbonate ion concentration derived from B/Ca was homogeneous [mean ± SEM (μmol kg–1): Site 1 = 579 ± 34, Site 2 = 541 ± 27, Site 3 = 568 ± 30] regardless of seawater pH. Furthermore, gross calcification rate (GCR, mass of CaCO3 deposited on the skeletal unit area per unit of time), estimated by a “bio-inorganic model” (IpHRAC), was homogeneous with decreasing pH. The homogeneous GCR, internal pH and carbonate chemistry confirm that the features of the “building blocks” – the fundamental structural components – produced by the biomineralization process were substantially unaffected by increased acidification. Furthermore, the pH up-regulation observed in this study could potentially explain the previous hypothesis that less “building blocks” are produced with increasing acidification ultimately leading to increased skeletal porosity and to reduced net calcification rate computed by including the total volume of the pore space. In fact, assuming that the available energy at the three sites is the same, this energy at the low pH sites could be partitioned among fewer calicoblastic cells that consume more energy given the larger difference between external and internal pH compared to the control, leading to the production of less building blocks (i.e., formation of pores inside the skeleton structure, determining increased porosity). However, we cannot exclude that also dissolution may play a role in increasing porosity. Thus, the ability of scleractinian corals to maintain elevated pHcf relative to ambient seawater might not always be sufficient to counteract declines in net calcification under OA scenarios

    The Skeletal Organic Matrix from Mediterranean Coral Balanophyllia europaea Influences Calcium Carbonate Precipitation

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    Scleractinian coral skeletons are made mainly of calcium carbonate in the form of aragonite. The mineral deposition occurs in a biological confined environment, but it is still a theme of discussion to what extent the calcification occurs under biological or environmental control. Hence, the shape, size and organization of skeletal crystals from the cellular level through the colony architecture, were attributed to factors as diverse as mineral supersaturation levels and organic mediation of crystal growth. The skeleton contains an intra-skeletal organic matrix (OM) of which only the water soluble component was chemically and physically characterized. In this work that OM from the skeleton of the Balanophyllia europaea, a solitary scleractinian coral endemic to the Mediterranean Sea, is studied in vitro with the aim of understanding its role in the mineralization of calcium carbonate. Mineralization of calcium carbonate was conducted by overgrowth experiments on coral skeleton and in calcium chloride solutions containing different ratios of water soluble and/or insoluble OM and of magnesium ions. The precipitates were characterized by diffractometric, spectroscopic and microscopic techniques. The results showed that both soluble and insoluble OM components influence calcium carbonate precipitation and that the effect is enhanced by their co-presence. The role of magnesium ions is also affected by the presence of the OM components. Thus, in vitro, OM influences calcium carbonate crystal morphology, aggregation and polymorphism as a function of its composition and of the content of magnesium ions in the precipitation media. This research, although does not resolve the controversy between environmental or biological control on the deposition of calcium carbonate in corals, sheds a light on the role of OM, which appears mediated by the presence of magnesium ions

    Security Messages: Or, How I Learned to Stop Disregarding and Heed the Warning

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    Attacks on information security continue to be reported in the media, and result in large losses for organizations. While some attacks are the result of sophisticated threats, others can be traced to failures by organizational insiders to observe basic security policies such as using caution when opening unsolicited email attachments. Faced with the challenges and time demands of everyday stressors, security policy compliance can be costly for individuals; security actions require time and distract attention from other primary tasks. This costliness can lead individuals to ignore prompts to perform security updates, scan their computers for threats, or reboot their computers to apply security updates. This dissertation contains three studies that address the following overarching research question: How can end-user adherence to security messages be better understood and improved, and how can theory inform security-message design? First, two complementary studies are presented that examine the integration of media naturalness theory into a security message context using field study and fMRI designs. Study 1, the field study, unobtrusively captures objective measures of attention from Amazon Mechanical Turk users (N=510) as they perform a between-subjects deception protocol. Study 2, the fMRI study, examines neural activations from a within-subjects participant design (N=23) in response to different security message designs with integrated emotive human facial expressions. Data from studies 1 and 2 show that warnings with integrated facial expressions of threat (fear, disgust) generally elicited greater adherence rates and higher evidence of cognition and elaboration than did warnings with integrated neutral facial expressions or than did warnings with no integrated facial expressions, supporting our hypotheses. Study 3 explores the pattern of risk taking and analysis that users engage in when interacting with interruptive security messages. The corroboration of multiple behavioral dependent variables suggests that users predominantly use a bimodal risk tradeoff paradigm when interacting with interruptive security messages. All three studies address the overarching research question of understanding and improving end user adherence to security messages
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