Oxidation of aldehydes used as food additives by peroxynitrite

Benzaldehyde and its derivatives are used as food supplements. These substances can be used mainly as flavorings or as antioxidants. Besides, peroxynitrite, an oxidizing agent, could be formed in canned food. Both species could react between them. The present article has focused on the kinetic study of the oxidation of aldehydes by peroxynitrite. A reaction mechanism that justifies all the experimental results is proposed. This mechanism, in acidic media, passes through three competitive pathways: (a) a radical attack that produces benzoic acid. (b) peracid oxidation, and (c) a nucleophilic attack of peroxynitrous acid over aldehyde to form an intermediate, X, that produces benzoic acid, or, through a Cannizzaro-type reaction, benzoic acid and benzyl alcohol. All rate constants involved in the third pathway (c) have been calculated. These results have never been described in the literature in acid media. A pH effect was analyzed

A Spanish-language patient safety questionnaire to measure medical and nursing students' attitudes and knowledge.

[EN] OBJECTIVE: To design and validate a questionnaire for assessing attitudes and knowledge about patient safety using a sample of medical and nursing students undergoing clinical training in Spain and four countries in Latin America. METHODS: In this cross-sectional study, a literature review was carried out and total of 786 medical and nursing students were surveyed at eight universities from five countries (Chile, Colombia, El Salvador, Guatemala, and Spain) to develop and refine a Spanish-language questionnaire on knowledge and attitudes about patient safety. The scope of the questionnaire was based on five dimensions (factors) presented in studies related to patient safety culture found in PubMed and Scopus. Based on the five factors, 25 reactive items were developed. Composite reliability indexes and Cronbach's alpha statistics were estimated for each factor, and confirmatory factor analysis was conducted to assess validity. After a pilot test, the questionnaire was refined using confirmatory models, maximum-likelihood estimation, and the variance-covariance matrix (as input). Multiple linear regression models were used to confirm external validity, considering variables related to patient safety culture as dependent variables and the five factors as independent variables. RESULTS: The final instrument was a structured five-point Likert self-administered survey (the "Latino Student Patient Safety Questionnaire") consisting of 21 items grouped into five factors. Compound reliability indexes (Cronbach's alpha statistic) calculated for the five factors were about 0.7 or higher. The results of the multiple linear regression analyses indicated good model fit (goodness-of-fit index: 0.9). Item-total correlations were higher than 0.3 in all cases. The convergent-discriminant validity was adequate. CONCLUSIONS: The questionnaire designed and validated in this study assesses nursing and medical students' attitudes and knowledge about patient safety. This instrument could be used to indirectly evaluate whether or not students in health disciplines are acquiring and thus likely to put into practice the professional skills currently considered most appropriate for patient safety

Palaeozoic – Early Mesozoic geological history of the Antarctic Peninsula and correlations with Patagonia: Kinematic reconstructions of the proto-Pacific margin of Gondwana

The Antarctic Peninsula preserves geological evidence of a long-lived continental margin with intrusive, volcaniclastic and accretionary complexes indicating a convergent margin setting from at least the Cambrian to the Cenozoic. We examine the poorly understood units and successions from the Palaeozoic to the Early Mesozoic and develop detailed kinematic reconstructions for this section of the margin. We use existing geochronology, along with newly presented Usingle bondPb detrital zircon geochronology, combined with detailed field evidence to develop correlations between geological units and tectonic events across Patagonia and the proto-Antarctic Peninsula. The continental margin of Gondwana/Pangea was a convergent margin setting punctuated by crustal block translation, deformation, magmatic pulses (flare-ups) and development of thick accretionary complexes. These events are strongly linked to subducting slab dynamics and a para-autochthonous model is proposed for the long-lived margin. Major magmatic pulses are evident during the Ordovician (Famatinian) and Permian, and the magmatic record is reflected in the detrital zircon age profiles of metasedimentary successions of the northern Antarctic Peninsula and Tierra del Fuego. Major tectonic events during the Carboniferous – Permian (Gondwanide Orogeny) and Triassic (Chonide Event – Peninsula Orogeny) are recognised across the Antarctic Peninsula – Patagonia and are correlated to potential terrane suturing and flat slab dynamics. Our kinematic reconstructions developed in GPlates, combined with geological field relationships have allowed us to model the locus of magmatism relative to the active margin and also the likely source for thick sedimentary successions

Native American gene flow into Polynesia predating Easter Island settlement

The possibility of voyaging contact between prehistoric Polynesian and Native American populations has long intrigued researchers. Proponents have pointed to the existence of New World crops, such as the sweet potato and bottle gourd, in the Polynesian archaeological record, but nowhere else outside the pre-Columbian Americas1,2,3,4,5,6, while critics have argued that these botanical dispersals need not have been human mediated7. The Norwegian explorer Thor Heyerdahl controversially suggested that prehistoric South American populations had an important role in the settlement of east Polynesia and particularly of Easter Island (Rapa Nui)2. Several limited molecular genetic studies have reached opposing conclusions, and the possibility continues to be as hotly contested today as it was when first suggested8,9,10,11,12. Here we analyse genome-wide variation in individuals from islands across Polynesia for signs of Native American admixture, analysing 807 individuals from 17 island populations and 15 Pacific coast Native American groups. We find conclusive evidence for prehistoric contact of Polynesian individuals with Native American individuals (around AD 1200) contemporaneous with the settlement of remote Oceania13,14,15. Our analyses suggest strongly that a single contact event occurred in eastern Polynesia, before the settlement of Rapa Nui, between Polynesian individuals and a Native American group most closely related to the indigenous inhabitants of present-day Colombia

ARCHAEOMETRIC CHARACTERIZATION OF THE CERAMICS FROM TWO CELTIBERIAN HILLFORTS: PRELIMINARY RESULTS

<p>In this work, we present the preliminary results of the archaeometric analysis of several ceramic and clay samples from two Celtiberian hillforts of the Iron Age from the Spanish Central Plateau: El Ceremeño and its cemetery (Early and Middle Iron Age) and the oppidum of Los Rodiles (Late Iron Age) including La Rodriga, a potter's workshop contemporary to Los Rodiles. Clay samples were collected from all sites in order to carry out a provenance analysis and to determine if the ceramic production of the proposed archaeological sites was local or foreign. Mineralogical analysis was performed by Thin-Layer Petrography (TLP) and XRay Diffraction (XRD), whereas chemical analysis was done by X-Ray Fluorescence: Semi-quantitative (XRF) and Trace Elemental analysis (XRF-t). Moreover, to complete the study a thermal analysis was carried out by a dilatometer (DLT). Although the number of samples evaluated was limited, in all the studied cases, the analyzed pottery was clearly found to be made with the clay from the surroundings of the archaeological sites.</p

Middle to Late Miocene Contractional Deformation in Costa Rica Triggered by Plate Geodynamics

OVSICORIContractional deformation in Costa Rica is usually attributed to the subduction of the aseismic Cocos Ridge. In this work, we review the evidences for contraction in the middle to late Miocene, prior to the arrival of the Cocos Ridge at the Middle America Trench. We find that the Miocene phase of contractional deformation is found in all of Costa Rica, probably extending to Nicaragua as well. The widespread distribution of this event requires a regional or plate geodynamic trigger. We analyze the possible mechanisms that could produce the onset of contractional deformation, using the better known case of subduction orogeny, the Andes, as an analog. We propose that a change in the direction of the Cocos plate since ∼19 Ma led to a change from oblique to orthogonal convergence, producing contractional deformation of the upper plate.La deformación por contracción en Costa Rica generalmente se atribuye a la subducción de la asísmica Cocos Ridge. En este trabajo, revisamos las evidencias de contracción en el Mioceno medio a tardío, antes de la llegada de Cocos Ridge a la Fosa de Mesoamérica. Encontramos que la fase de deformación por contracción del Mioceno se encuentra en toda Costa Rica, probablemente extendiéndose también a Nicaragua. La amplia distribución de este evento requiere un desencadenante geodinámico regional o de placas. Analizamos los posibles mecanismos que podrían producir el inicio de la deformación contractiva, utilizando el caso más conocido de orogenia de subducción, los Andes, como análogo. Proponemos que un cambio en la dirección de la placa de Cocos desde ∼19 Ma llevó a un cambio de convergencia oblicua a ortogonal, produciendo una deformación por contracción de la placa superior.Universidad Nacional de Cuyo, ArgentinaUniversidad Nacional, Costa RicaUniversidad de Costa Rica, Costa RicaServicio Nacional de Geología y Minería, ChileUniversidad de O’Higgins, ChileInstituto Argentino de Nivología, Glaciología y Ciencias Ambientales, ArgentinaObservatorio Vulcanológico y Sismológico de Costa Ric

Neonates from women with pregestational maternal obesity show reduced umbilical vein endothelial response to insulin

Objective: Pregestational maternal obesity (PGMO) associates with foetoplacental vascular endothelial dysfunction and higher risk for insulin resistance in the neonate. We characterised the PGMO consequences on the insulin response of the human foetoplacental vasculature. Methods: Umbilical veins were from pregnancies where the mother was with PGMO (body mass index 30–42.3 kg/m, n = 33) or normal pregestational weight (PGMN) (body mass index 19.5–24.4 kg/m, n = 21) with total gestational weight gain within the physiological range. Umbilical vein ring segments were mounted in a myograph for isometric force measurements. Primary cultures of human umbilical vein endothelial cells were used in passage 3. Vessel rings and cells were exposed to 1 nmol/L insulin (20 min) in the absence or presence of 100 μmol/L N-nitro-L-arginine methyl ester (inhibitor of nitric oxide synthase, NOS). Results: Vessel rings from PGMO showed reduced nitric oxide synthase-activity dependent dilation to insulin or calcitonin-gene related peptide compared with PGMN. PGMO associated with higher inhibitor phosphorylation of the insulin receptor substrate 1 (IRS-1) and lower activator phosphorylation of protein kinase B/Akt (Akt). Cells from PGMO also showed lower nitric oxide level and reduced activator serine but increased inhibitor threonine phosphorylation of endothelial nitric oxide synthase (eNOS) and saturable transport of L-arginine. HUVECs from PGMO were not responsive to insulin. Conclusion: The lack of response to insulin by the foetoplacental endothelium may result from reduced IRS-1/Akt/eNOS signalling in PGMO. These findings may result in higher risk of insulin resistance in neonates to PGMO pregnancies

On the pathways. Inter-nodal archaeology in the Atacama desert Pampa (c. 7000 BP-400 BP)

•Pre-Hispanic pathways meshwork of the Atacama Desert.•Internodal spaces with a diversity of practices and travelers revealing a variety of mobility strategies and dynamics.•Pre-Hispanic social imaginaries through ceremonial sites, rock art and geoglyphs.•Knowing the people who travelled and their connections through isotopes and burial offerings.•Direct evidence of transit from the Archaic Period (c. 7000 BP) until the end of Late or Inka Period (c. 450 BP).•Sites in Ancachi and Calate show a greater concentration of evidence for the entire sequence. We present a synthesis of our investigation into pre-Hispanic pathways of the Atacama Desert Pampa -one of the driest and harshest environments on our planet- where we have identified a variety of mobility strategies and dynamics deployed by the different communities that inhabited both the Pacific coast and the inland oases of this region. Specifically, we focus on the inter-nodal archaeological and biogeochemical data that provides direct evidence of the presence of individuals from myriad regions traversing this area from the Middle Archaic to Late periods (c. 7000 BP-400 BP). Moreover, we analyze how, beginning in the Formative Period, this multiplicity of peoples employed different mobility systems, circulation, relationships, and social exchanges to integrate this apparent “empty space”. In doing so, we discuss and reformulate the classic highland caravanning model of the Andes, which considered highland caravanning groups as the only agents promoting long-distance mobility and exchange