239 research outputs found
Formation of Clay-Rich Layers at The Slip Surface of Slope Instabilities: The Role of Groundwater
Some landslides around the world that have low-angle failure planes show exceptionally poor mechanical properties. In some cases, an extraordinarily pure clay layer has been detected on the rupture surface. In this work, a complex landslide, the so-called Diezma landslide, is investigated in a low-to moderate-relief region of Southeast Spain. In this landslide, movement was concentrated on several surfaces that developed on a centimeter-thick layer of smectite (montmorillonite-beidellite) clay-rich level. Since these clayey levels have a very low permeability, high plasticity, and low friction angle, they control the stability of the entire slide mass. Specifically, the triggering factor of this landslide seems to be linked to the infiltration of water from a karstic aquifer located in the head area. The circulation of water through old failure planes could have promoted the active hydrolysis of marly soils to produce new smectite clay minerals. Here, by using geophysical, mineralogical, and geochemical modelling methods, we reveal that the formation and dissolution of carbonates, sulfates, and clay minerals in the Diezma landslide could explain the elevated concentrations of highly plastic secondary clays in its slip surface. This study may help in the understanding of landslides that show secondary clay layers coinciding to their low-angle failure planes.This study was supported by the research projects PID2019-107138RB-I00 funded by the Spanish Ministry of Science and Innovation and P18-RT-3632 funded by the Junta de Andalucí
Past, present and future global influence and technological applications of iron-bearing metastable nanominerals
Iron-bearing nanominerals such as ferrihydrite, schwertmannite, and green rust behave as metastable precursors leading to the formation of more thermodynamically stable iron mineral phases (e.g., jarosite, goethite, hematite, and magnetite). However, this transformation may last from days to tens or even hundreds of years, making them the most predominant iron-bearing minerals at environmental conditions and at the human time scale. The present review characterizes ferrihydrite, schwertmannite, and green rust nanominerals according to their main physical and chemical properties, and at both nano- and meso-scales. It also presents a comprehensive review of the multiple past and present Earth environments where these nanominerals have played, and still play, a pivotal role in the geochemistry, mineralogy and environmental nanogeosciences of these environments. Finally, the present and future technological applications of these nanominerals as well as their role in the generation of a more sustainable human-Earth relationship is discussed, with a special emphasis on their use in new circular economies and green based technologies
Mineral equilibria and thermodynamic uncertainties in the geothermometrical characterisation of carbonate geothermal systems of low temperature. The case of the Alhama-Jaraba system (Spain)
Geothermometrical characterisation of low-temperature, carbonate-evaporitic geothermal systems is usually hampered by the lack of appropriate mineral equilibria to successfully use most of the classical geothermometers and/or by the thermodynamic uncertainties affecting some of the most probable mineral equilibria in low temperature conditions. This situation is further hindered if the thermal waters are additionally affected by secondary processes (e.g., CO2 loss) during their ascent to surface. All these problems cluster together in the low-temperature Alhama-Jaraba thermal system, hosted in carbonate rocks, with spring temperatures about 30 °C and waters of Ca-Mg−HCO3/SO4 type. This system, one of the largest naturally flowing (600 L/s) low temperature thermal systems in Europe, is used in this paper as a suitable frame to assess the problems in the application of chemical geothermometrical techniques (classical geothermometers and geothermometrical modelling) and to provide a methodology that could be used in this type of geothermal system or in potential CO2 storage sites in similar aquifers. The results obtained have shown that the effects of the secondary processes can be avoided by selecting the samples unaffected by such processes and, therefore, representative of the conditions at depth, or by applying existing methodologies to reconstruct the original composition, as is usually done for medium to high temperature systems. The effective mineral equilibria at depth depend on the temperature, the residence time and the specific lithological/mineralogical characteristics of the system studied. In the present case, the mineral equilibria on which classical cation geothermometers are based have not been attained. The low proportion of evaporitic minerals in the hosting aquifer prevents the system from reaching anhydrite equilibrium, otherwise common in carbonate-evaporitic systems and necessary for the specific SO4-F geothermometer or the specially reliable quartz (or chalcedony) – anhydrite equilibrium in the geothermometrical modelling of these geothermal systems. Under these circumstances, the temperature estimation must rely on quartz (or chalcedony), clay minerals and, especially, calcite and dolomite. However, clay minerals and dolomite present important thermodynamic uncertainties related to possible variations in composition or crystallinity degree for clays and order/disorder degree for dolomite. To deal with these problems, a sensitivity analysis to the thermodynamic data for clay minerals has been carried out, comparing the results obtained when considering different solubility data. The uncertainties associated with dolomite have been addressed by reviewing the solubility data available for dolomites with different order degrees and performing specific calculations for the order degree of the dolomite in the aquifer. This approach can be used to find the most adequate dolomite thermodynamic data for the system under consideration, including medium-high temperature geothermal systems. Finally, the temperature estimation of the Alhama-Jaraba waters in the deep reservoir has been obtained from simultaneous equilibria of quartz, calcite, partially disordered dolomite and some aluminosilicate phases. The obtained value of 51 ± 14 °C is within the uncertainty range normally affecting this type of estimations and is coherent with independent estimations from geophysical data
Il legame tra la privazione del sonno e gli errori commessi dagli infermieri durante il turno di notte
Introduction: Nurses who work at night often experience high levels of sleepiness, which are the biological consequence of the circadian rhythm, which induces sleep at particular hours of the night, increasing the risk of errors and accidents.
Objective: According to the latest data declared by the World Organization of Healthcare (WHO), at least 134 million patients are victims every year adverse events that occur due to the lack of safety in the health care and and 2.6 million those who die from it, but most of these deaths are avoidable. The study aims to investigate the relationship between sleep deprivation and errors in patient care by the nursing staff who works the night shift. In the aviation and transportation sectors, studies conducted revealed as sleep deprivation increases the risk of mistakes. Few researches have investigated nighttime nursing.
Method: A literature search was conducted by interrogating banks PubMed and Cochrane data limiting article selection to the last 10 years. Only one study met our benchmarks: “Sleep deprivation and error in Nurses who work the night shift ”of 2014, by Arlene L. Johnson, whose questionnaire it was adapted to the Italian situation and administered to a sample of 41,000 nurses, to which 3358 responded.
Results: 94.7% of the interviewees, during the night shift, carry out ordinary activities. 16.8 of respondents made mistakes in the last two night shifts; in 59.5% of the cases only one mistake was made. Lack of sleep (3-5 hours of sleep during the 24 hours of the day before the interview) seems to determine a higher frequency of errors. This trend is particularly marked a nurses working in critical wards (23.9%). Even the number of nights, affects the propensity to make mistakes, with an error rate of 20.5%.
Keywords: night shift, nurses, medical error, quality of careIntroduzione: Gli infermieri che lavorano di notte, spesso sperimentano alti livelli di sonnolenza, che sono la conseguenza biologica del ritmo circadiano, che induce il sonno in particolari ore della notte, aumentando il rischio di errori ed incidenti.
Obiettivo: Secondo gli ultimi dati dichiarati dall’Organizzazione Mondiale della Sanità (Oms), sono almeno 134 milioni i pazienti che ogni anno sono vittime di eventi avversi che si verificano a causa della mancanza di sicurezza nelle prestazioni sanitarie e 2,6 milioni quelli muoiono per questo, ma la maggior parte di questi decessi sono evitabili. Lo studio ha l’obiettivo di indagare la relazione tra la privazione del sonno e gli errori nell’assistenza sanitaria al paziente, da parte del personale infermieristico che lavora nel turno di notte. Nel settore aeronautico ed in quello dei trasporti, gli studi condotti hanno rilevato come la privazione di sonno aumenti il rischio di errori. Poche le ricerche che hanno indagato l’assistenza notturna infermieristica.
Metodo: È stata condotta una ricerca della letteratura interrogando le banche dati PubMed e Cochrane limitando la selezione degli articoli agli ultimi 10 anni. Solo uno studio ha soddisfatto i nostri parametri:“ Sleep Deprivation and Error in Nurses who Work the Night Shift” del 2014, di Arlene L. Johnson, il cui questionario è stato adattato alla realtà italiana e somministrato ad un campione di 41 mila infermieri, al quale hanno risposto in 3358.
Risultati: Il 94,7% dei rispondenti, durante il turno notturno, svolge attività ordinaria. Il 16,8 dei rispondenti ha commesso errori negli ultimi due turni notturni; nel 59,5 % dei casi è stato commesso un solo errore. La carenza di sonno (3-5 ore dormite nell’arco delle 24 ore del giorno che precede l’intervista) sembra determinare una maggiore frequenza di errori. Questa tendenza è particolarmente marcata presso gli infermieri impegnati nei reparti di area critica (23,9%). Anche il numero di notti, incide sulla propensione a commettere errori, con una frequenza di errore del 20,5%.
Parole chiave: lavoro per turni, turno notturno, infermieri, qualità, error
Risk of aortic dissection in patients with ascending aorta aneurysm: a new biological, morphological, and biomechanical network behind the aortic diameter
Thoracic aortic aneurysm represents a deadly condition, particularly when it evolves into rupture and dissection. Proper surgical timing is the key to positively influencing the survival of patients with this pathology. According to the most recent guidelines, ascending aorta size ≥ 55 mm and a rate of growth ≥ 0.5 cm per year are the most important factors for surgical indication. Nevertheless, a lot of evidence show that aortic ruptures and dissections might occur also in small size ascending aorta. In this review, we sought to analyze a new biological and morphological network behind the aortic diameter that need to be considered in order to identify the portion of patients with thoracic aortic aneurysm who are at increased risk of aortic complications, despite current aortic guidelines not advising surgical intervention in this group
Echoes from Intrinsic Connectivity Networks in the Subcortex
Decades of research have greatly improved our understanding of intrinsic human brain organization in terms of functional networks and the transmodal hubs within the cortex at which they converge. However, substrates of multinetwork integration in the human subcortex are relatively uncharted. Here, we leveraged recent advances in subcortical atlasing and ultra-high field (7 T) imaging optimized for the subcortex to investigate the functional architecture of 14 individual structures in healthy adult males and females with a fully data-driven approach. We revealed that spontaneous neural activity in subcortical regions can be decomposed into multiple independent subsignals that correlate with, or “echo,” the activity in functional networks across the cortex. Distinct subregions of the thalamus, striatum, claustrum, and hippocampus showed a varied pattern of echoes from attention, control, visual, somatomotor, and default mode networks, demonstrating evidence for a heterogeneous organization supportive of functional integration. Multiple network activity furthermore converged within the globus pallidus externa, substantia nigra, and ventral tegmental area but was specific to one subregion, while the amygdala and pedunculopontine nucleus preferentially affiliated with a single network, showing a more homogeneous topography. Subregional connectivity of the globus pallidus interna, subthalamic nucleus, red nucleus, periaqueductal gray, and locus coeruleus did not resemble patterns of cortical network activity. Together, these finding describe potential mechanisms through which the subcortex participates in integrated and segregated information processing and shapes the spontaneous cognitive dynamics during rest
Past, present and future global influence and technological applications of iron-bearing metastable nanominerals
Iron-bearing nanominerals such as ferrihydrite, schwertmannite, and green rust behave as metastable
precursors leading to the formation of more thermodynamically stable iron mineral phases (e.g., jarosite, goethite, hematite, and magnetite). However, this transformation may last from days to tens or even hundreds of years, making them the most predominant iron-bearing minerals at environmental conditions and at the human time scale. The present review characterizes ferrihydrite, schwertmannite, and green rust nanominerals according to their main physical and chemical properties, and at both nano- and mesoscales. It also presents a comprehensive review of the multiple past and present Earth environments where these nanominerals have played, and still play, a pivotal role in the geochemistry, mineralogy and environmental nanogeosciences of these environments. Finally, the present and future technological applications of these nanominerals as well as their role in the generation of a more sustainable human- Earth relationship is discussed, with a special emphasis on their use in new circular economies and green based technologies.This research was partially supported by Advanced Mining Technology Center (AMTC) from Universidad de Chile; National Agency for Research and Development, ANID, through ANID-PIA Project AFB180004. MAC was financially supported by the Spanish Ministry of Science and Innovation through the Program Ramon y Cajal 2019, Grant RYC2019-026496-I. J.P.H.P. acknowledges the funding from the European Union’s Horizon 2020 Marie Skłodowska-Curie Innovative Training Network (grant no. 675219) and Helmholtz Recruiting Initiative (award no. I-044-16- 01). MPA was financially supported by the Junta de Andalucía through the Emergia Program 2020. Funding for open access charge: Universidad de Huelva / CBUA
Religious Pilgrimage: Experiencing Places, Objects and Events
This article explores the concept of the Eventization of faith (Pfadenhauer, 2010) through application of three case studies, to identify learning that might be applied to a traditional pilgrimage destination, such as Jerusalem. This Holy City is held sacred by the three Abrahamic religions, and faith-based tourism is central both to the Holy Land and to the city of Jerusalem (Leppakari & Griffin, 2017). This paper builds on research that identifies processes and models that provide insight into the developing concept of the eventization of faith. The work examines outcomes from three different perspectives: - The impact of traditional church-led pilgrimages to places in the Holy Land, on participants and their local church communities. - The successful eventization of the Lindisfarne Gospels as part of their release to Durham University in 2013, and the impact on local historical, cultural and religious identity and heritage (Dowson, 2019). - The shared pilgrimage experience of thousands of Christian women participating in the annual Cherish Conference in Leeds, Yorkshire, held in a secular event venue (Dowson, 2016). In analysing these three case study examples, this paper aims to identify factors that might enhance our understanding of the concept of eventization of faith. Utilising face to face interviews and online survey results, the research focuses on the aspects of community, identity and authenticity. Events enable shared experiences in a faith context (Lee et al., 2015), and so this research develops a model that captures and expresses approaches that might encourage pilgrimages to traditional destinations, through the medium of events, adding insight into the development of the academic concept of Eventization of Faith
Cooperativas agrícolas: uma análise bibliométrica da produção internacional
This research aimed to analyze the bibliometry research on agricultural cooperatives in the international scope. Based on the quantitative approach, the Web of Science base was used for surveying international production and from this perspective, as a keyword: Agricultural Cooperatives, without applying temporal cut or any other search filter. For the analysis of the production raised, the Bibliometric Laws of Bradford, Lotka and Zipf were used. The results demonstrate the concentration and approaches of the journals. It was noted the approaches on internal and external aspects: strategic developments, industrial organization, industrial and food systems. Besides that attributes for international and political comparisons were observed. According to the clusters it is concluded that the most used approach is agency theory, followed by problems of governance, strategic aspects, production and social aspects. This consideration is the effect of an average growth was 7.5% in the last 35 years.Esta pesquisa objetivou analisar a bibliometria das pesquisas sobre cooperativas agrícolas no âmbito internacional. A metodologia utiliza a Web of Science como base, com a palavra chave: Agricultural Cooperatives, sem recorte temporal e sem aplicar outro filtro, e aplica as Leis bibliométricas de Bradford, Lotka e Zipf para análise. Os resultados demonstração a concentração e os enfoques dos periódicos. Notaram-se as abordagens sobre aspectos internos e externos: desenvolvimentos estratégicos, organização industrial, sistemas industriais e alimentares. E ainda, aborda atributos voltados a comparações internacionais e políticas. A lei de Lokta foi respeitada pela distribuição de frequência encontrada, pois mais de 87% dos autores possuem apenas 1 publicação. A análise de similitude e de clusters possibilitou identificar os agrupamentos dos trabalhos encontrados. Os resultados indicaram que é um campo amplo, conforme os troncos de similitude e clusters encontrados. Além disso, existe um crescimento médio foi de 7,5% nos últimos 35 anos
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