259 research outputs found
A new database of the quantitative cathodoluminescence of the main quarry marbles used in antiquity
Quantitative cathodoluminescence (CL) has rarely been applied for the archaeometric studies concerning marble provenance, despite its potential. This paper develops the method and provides a new database of the parameters obtained from the main marble quarries used in antiquity. With a total number of 473 marble samples from ten districts of the central and eastern Mediterranean, it is the first database on quantitative CL, with the additional advantage of being the same samples that have already characterized by other conventional techniques and that are available in the literature. Focused on the measurements of the intensity peaks at the UV and visible spectra, registered by a spectrometer coupled to a scanning electron microscope (CL-SEM), the representative values are plotted on different useful diagrams to be applied in the identification of marble provenance studies, as a complementary tool of other analyses
Petrography and mineralogy of the white marble and black stone of Göktepe (Mugla, Turkey) used in antiquity: New data for provenance determination
The discovery near Göktepe (Mugla province, Western Turkey) of an ancient quarrying site of white marbles and black stones has recently been reported by some authors. Assigning the provenance of stone from ancient artifacts to Göktepe is currently possible mainly thanks to chemical, EPR and MGS data. Petrographic description, which many researchers use to characterize ancient marbles, is still incomplete. Several thin sections of both types of stone were thus examined in this study, and also used for cathodoluminescence analysis. As the rock is >99% calcite, trace minerals could only be detected in some samples by XRD analysis of insoluble residues after acetic acid attack. Data on strontium and manganese contents and carbon and oxygen isotopes were also recorded, for better understanding of some petrographic features. A new method of grain size characterization was tentatively introduced to improve the description of grain size variability in the white marble. Microstructure and grain size measurements on thin sections of this marble identify two petrographic varieties: the first is extremely fine with signs of dynamic recrystallization, and the second exhibits texture and MGS similar to those of Carrara marble. Statuary samples of white marble from Villa Adriana (Tivoli, Rome), preliminarily assigned in a previous study partly to Carrara and partly to Göktepe quarry, are reconsidered here. A certain degree of variability was found in the structures and textures in the thin sections of the Göktepe black stone. It may have undergone transformations at an advanced stage of diagenesis. One important source of this variability seems to be a fluid alteration event, revealed by both isotopic and chemical data and trace mineral assemblages
A new hybrid taxon on genus Thymus L. collected in Aragón (Spain)
MXrEo SANZ, G.; MERcADAL FERRERUELA, N. E. & Písco GARCÍA, J. M. 1995. Sobre un hibrido nuevo del género Thymus L. detectado en Aragón. Bot. Complutensis 20: 69-73. Se comunica el hallazgo de un nuevo hibrido del género Thwnus L. (Labiatae) en la provincia de Teruel, el cual se describe con el nombre de Th. x henitoi Mateo, Mercadal & Pisco, nothosp. nswa, alquc se le supone la combinación parental Th. godayanus Rivas-Martínez et al. x Ni. pulegioides L.Málvo SANZ. G.; MERCADAI. FERRERtJELA, N. E. & Písco GARCÍA, J. M, 1995. A new hybrid taxon on genus Thymus L. collected in Aragón (Spain). BoL Coniplutensis 20: 69-73. A new nothospccics belonging to the genus Thvmus L. (Labiatae) coming from Teruel province (Aragon, NE Spain) is described. The new name proposed is Th. benitoi Mateo, Mercadal & Pisco, nothosp. nova. which its presumed parents are Ni. goda yanas Rivas-Martínez eraL and ib. pulegioides L
N-Palmitoylphosphatidylethanolamine stabilizes liposomes in the presence of human serum: effect of lipidic composition and system characterization
AbstractLiposomes containing negatively-charged phospholipid, N-palmitoylphosphatidylethanolamine (NPPE) were examined for stability in the presence of human serum, using the release of the entrapped 5,6-carboxyfluorescein as an aqueous marker. Either small unilamellar vesicles (SUV) or large unilamellar vesicles (LUV) were used. Incorporation of NPPE into PC SUV decreases leakage in the presence of serum or phosphate-buffered saline, no strictly related to size increase observed and to the surface negative charge present. The stabilizing effect of NPPE and Chol were synergistic. Inhibition of destabilization induced by serum of PC/Chol liposomes was observed when NPPE concentrations were above 12 mol%. Change in the membrane fluidity or incorporation of a monosialoganglioside into liposomes do not significantly change the half-life of liposomes in the presence of a high NPPE concentration. Incorporation of NPPE into PC/Chol liposomes increases membrane rigidity which does not change after serum incubation. The presence of NPPE in liposomes decreases lipid transfer/exchange between liposomes and lipoproteins although the same amount of serum proteins were incorporated as in PC/Chol liposomes. As expected, these proteins are accessible to trypsin digestion. In accordance with these results, the liposome agglutination assay shows no steric barrier activity. As a whole, the results obtained in this paper suggest a complex mechanism for stabilization of NPPE containing liposomes in human serum
Psychometric properties of the mindfulness in teaching scale among Spanish teachers
Mindfulness in the educational field provides several benefits. The assessment of mindfulness is a fundamental previous step for evidence-based interventions. Therefore, the present study aimed to adapt and validate the Mindfulness in Teaching Scale (MTS) among Spanish teachers. This scale comprises 14 items on two dimensions: intrapersonal and interpersonal. The sample comprised 398 teachers (31% males, 68% females) whose ages ranged from 25 to 69 years (M = 44.14; SD = 10.16). Once the scale was adapted in Spanish, we examined its psychometric properties. To do so, we conducted a Confirmatory Factor analysis (CFA), which supported the two-factor structure. As evidence for validity, the MTS scores correlated with perceived teaching self-efficacy. The reliability values using Cronbach’s alpha were good. This scale has adequate psychometric properties and is useful for assessing mindfulness among Spanish teachers. We discuss its implications for the education field
The INTERPRET Decision-Support System version 3.0 for evaluation of Magnetic Resonance Spectroscopy data from human brain tumours and other abnormal brain masses.
Background
Proton Magnetic Resonance (MR) Spectroscopy (MRS) is a widely available technique for those clinical centres equipped with MR scanners. Unlike the rest of MR-based techniques, MRS yields not images but spectra of metabolites in the tissues. In pathological situations, the MRS profile changes and this has been particularly described for brain tumours. However, radiologists are frequently not familiar to the interpretation of MRS data and for this reason, the usefulness of decision-support systems (DSS) in MRS data analysis has been explored.
Results
This work presents the INTERPRET DSS version 3.0, analysing the improvements made from its first release in 2002. Version 3.0 is aimed to be a program that 1st, can be easily used with any new case from any MR scanner manufacturer and 2nd, improves the initial analysis capabilities of the first version. The main improvements are an embedded database, user accounts, more diagnostic discrimination capabilities and the possibility to analyse data acquired under additional data acquisition conditions. Other improvements include a customisable graphical user interface (GUI). Most diagnostic problems included have been addressed through a pattern-recognition based approach, in which classifiers based on linear discriminant analysis (LDA) were trained and tested.
Conclusions
The INTERPRET DSS 3.0 allows radiologists, medical physicists, biochemists or, generally speaking, any person with a minimum knowledge of what an MR spectrum is, to enter their own SV raw data, acquired at 1.5 T, and to analyse them. The system is expected to help in the categorisation of MR Spectra from abnormal brain masses
Validation of the Spanish Version of the Lucidity and Consciousness in Dreams Scale
Lucid dreaming, a specific phenomenon of dream consciousness, refers to the experience being aware that one is dreaming. The primary aim of this research was to validate a Spanish version of the Lucidity and Consciousness in Dreams scale (LuCiD). A secondary aim was to explore whether meditation experience and mindfulness trait were related to LuCiD scores. Data from 367 Spanish men (34.6%) and women (65.4%) who completed LuCiD, the Five Facets of Mindfulness Questionnaire (FFMQ), and the Positive and Negative Affect Schedule (PANAS) were examined. From the total sample, 40.3% indicated some experience with formal meditation (meditators), while 59.7% did not have any meditation experience (non-meditators). A random subsample of 101 participants, who completed LuCiD for a second time after a period of 10-15days, was used for test-retest reliability analysis. The LuCiD scale comprises 28 items distributed across eight factors: insight, control, thought, realism, memory, dissociation, negative emotion, and positive emotion. Factor structure, reliability by both internal consistency and test-retest reliability, and construct and concurrent validity were tested. Confirmatory factor analysis (CFA) confirmed the original eight-factor model, showing goodness of fit in contrast to a single-factor model. Item 15 was deleted from the Dissociation factor as it performed poorly (i.e., skewness and kurtosis, non-normal distribution of responses, and corrected item-total correlation under 0.40). The scale showed adequate values of internal consistency (between alpha=0.65 for Memory and alpha=0.83 for Positive Emotion) and test-retest reliability by significant Pearson correlations (p < 0.001) for each factor. The scores of meditators were higher for the LuCiD scale Insight and Dissociation factors, in contrast to those of non-meditators. The Observing facet of mindfulness was positively associated with all LuCiD factors, except Realism and Positive Emotion, and the Acting with Awareness facet showed a negative correlation with the LuCiD factor Realism. Finally, positive and negative affects was associated with the LuCiD factors Positive Emotion and Negative Emotion. This study provides a valid and reliable measure for exploring lucidity and consciousness in dreams for a Spanish population, Moreover, the results suggest a relationship with meditation experience, mindfulness trait, and positive and negative affect.</p
Validation of the Spanish version of the Multidimensional State Boredom Scale (MSBS)
Background: Boredom, which is a common problem in the general population, has been associated with several psychiatric disorders. The Multidimensional State Boredom Scale (MSBS) was developed, based on a theoretically and empirically grounded definition of boredom, to assess this construct. The aim of the present study was to assess the psychometric properties of the Spanish validated version of the MSBS in a multi-age sample recruited from the general population.
Methods: The patients (N = 303) were recruited from primary care settings. In addition to the sociodemographic variables and the MSBS, the General Health Questionnaire 28 items (GHQ-28), Positive and Negative Affect Scale (PANAS), Negative subscale and the Mindful Attention Awareness Scale (MAAS) were administered. We used confirmatory factor analysis (CFA) to analyse the dimensionality of the MSBS. Cronbach’s a coefficient was used to analyse the internal consistency of the scale. The consistency of the MSBS over time (test-retest reliability) was assessed using the intra-class correlation coefficient. The construct validity was examined by calculating Pearson’s r correlations between the MSBS with theoretically related and unrelated constructs. Cronbach’s a for MSBS was 0.89 (95 % CI, 0.87–0.92), ranging from 0.75 to 0.83 for the 5 subscales.
Results: The characteristics of the final sample (N = 303) were that the participants were primarily female (66.77 %) with a mean age of 49.32 years (SD, 11.46) and primarily European (94.71 %). The CFA of the MSBS confirmed that the original five-factor model showed good fit indices: CFI = .96; GFI = .94; SRMR = .05; and RMSEA = .06 [.05–.08]. Cronbach’s a for MSBS was 0.89 (95 % CI, 0.87–0.92), ranging from 0.75 to 0.83 for the 5 subscales. The MSBS showed a test-retest coefficient measured with an ICC of 0.90 (95 % CI, 0.88–0.92). The ICC for the 5 subscales ranged from 0.81 to 0.89. The MSBS showed a significant negative correlation with MAAS and a significant positive correlation with the GHQ (total score and subscales) and PANAS-Negative Affect.
Conclusions: The Spanish version of the MSBS has been validated as a reliable instrument for measuring boredom in the general population. This study will facilitate the assessment of boredom for clinical and research purposes in Spanish-speaking populations
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