204 research outputs found
Mantos inducidos por microbialitas en sedimentos siliciclásticos plio-cuaternarios? del NO de Iberia
Microbial mats are organo-sedimentary deposits formed by
bacteria that trap or synthesize certain chemical elements. This type
of activity gives rise to the formation of lamellar and/or columnar
bioconstructions (stromatolites) and/or concentric structures (oncolites
and thrombolites). The study of microbial mats used to be
restricted mainly to marine and coastal environments related to the
formation of ancient carbonate sediments (Palaeozoic/Proterozoic),
and/or extreme conditions in hypersaline environments. However,
in recent years, the presence of these forms has been identified in
continental siliciclastic rocks and sediments with a temporal distribution
that reaches into modern times. In this study, several levels
of ferruginous crusts associated with microbial activity are found,
interspersed in a Cenozoic deposit located in the province of Zamora.
This deposit consists of concentric, laminated iron structures
filled with silt, interspersed throughout a clayey-silt layer of variegated
colors which shows signs of bioturbation and desiccation due to
fluid escape. These findings allow the inference of the sedimentary
and climatic conditions responsible for the growth and preservation
of microbial mats in the siliciclastic sediments of the north-western
edge of the Duero BasinLos mantos microbiales constituyen depósitos organosedimentarios
formados por bacterias que atrapan o sintetizan determinados
elementos químicos. Este tipo de actividad da lugar a la formación de
estructuras laminares y/o columnares (estromatolitos) y/o concéntricas
(oncolitos y trombolitos). Su estudio, por tanto, quedaba reducido principalmente
a ambientes marinos y litorales relacionados con la formación
de sedimentos carbonatados de edad muy antigua (Paleozoico/
Proterozoico), y/o condiciones extremas en ambientes hipersalinos. Sin
embargo, en los últimos años, se ha identificado la presencia de estas
formas en rocas y sedimentos de afinidad continental y carácter siliciclástico,
que se extienden temporalmente hasta la actualidad. En este
estudio, se presenta el hallazgo de varios niveles de costras ferruginosas
asociadas a la actividad microbiana, intercalados en un depósito
cenozoico de la provincia de Zamora. Se trata de una serie de niveles
caracterizados por la presencia de capas ferruginosas laminadas y concéntricas,
constituidas por limos que aparecen en el techo y muro de
un nivel arcilloso-limoso de colores abigarrados y signos de bioturbación
y desecación por escape de fluidos. Este singular hallazgo permite
establecer las condiciones sedimentarias y climáticas responsables del
crecimiento y conservación de mantos microbianos en sedimentos siliciclásticos
del borde noroccidental de la cuenca del Duer
Entrepreneurship and Social Work: a comparison between Social Work students and graduates
Social Work is a profession dedicated to help people who have a problematic situation to be solved. Social Workers have abilities and resources to resolve problems and they use the abilities of the person who needs that help to empower them. The ambit of those professionals is very varied: public administration, private companies or NGOs. In this context, we analyze the role played by entrepreneurs. In this work we have collected information that allows us to draw conclusions about social entrepreneurship and the vision that social workers have about that movement. To do so, we have sent a questionnaire, previously validated by experts in the field, aimed at Social Work students and graduates. The treatment of this informaticon has enabled us to find out their opinion about entrepreneurship, the differences in the way of thinking between both groups concerning the creation or not of companies and if they believe that they might be entrepreneurs in the future. We have detected little entrepreneurial spirit among social workers, partly due to the lack of this entrepreneurial culture not only in society but also in the curriculum of Social Work degrees
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Organic fraction of municipal solid waste for the production of L-lactic acid with high optical purity
The organic fraction of municipal solid waste (OFMSW) is an abundant biowaste with great potential in the bioeconomy model. Previous reports have demonstrated that OFMSW hydrolysates are good substrates for lactic acid (LA) production. However, LA can exist in two enantiomeric forms (L- and D-) and most commercial LA applications require a high enantiomeric purity, typically of the L-isomer. Due to natural occurring bacteria in the waste, a mixture of D- and L-LA can form in the substrate, reducing the final enantiomeric purity of the product and limiting its commercial application. In the research reported in this article, hydrolysates from OFMSW were evaluated for the production L-LA with high enantiomeric purity. Firstly, a pre-treatment with monopolar electrodialysis membranes was implemented to remove the unfavourable D-LA in the hydrolysate. This step allowed the reduction in LA concentration and subsequent fermentations of the hydrolysate resulted in enantiomeric purities over 98%. At the pilot scale, a fermentation of the pre-treated hydrolysate, by B. coagulans A166, resulted in a final LA concentration of 61.1 g L−1 and a yield of 0.94 g g−1. The downstream of the process resulted on a LA recovery of 51.5% and a L-LA optical purity of 98.7%
Métodos de escalamiento aplicados a la priorización de necesidades de formación en organizaciones
Los criterios para priorizar las necesidades que justifican las acciones formativas a implantar no se suelen explicitar a priori en los programas de formación continua en contextos organizacionales. En este trabajo se proponen los métodos de escalamiento como procedimiento factible y útil para identificar criterios explícitos de priorización de necesidades, y se concreta cuál de ellos es más apropiado en este contexto de intervención. 404 empleados de una organización pública cumplimentaron un cuestionario ad hoc para priorizar necesidades formativas en diferentes áreas durante el período 2004 al 2006; concretamente, se ordenaron 117, 75 y 286 estímulos, respectivamente. Se calcularon y compararon las ordenaciones obtenidas con cuatro métodos de escalamiento: el método de Dunn-Rankin y tres métodos derivados de la Ley del Juicio Categórico de Thurstone, concretamente ordenación por rangos, intervalos sucesivos e intervalos aparentemente iguales. Con los resultados, se constata la factibilidad y utilidad de estos métodos de escalamiento para la solución de los problemas planteados; a partir de los métodos más precisos, se propone el uso del método de ordenación por rangos por su parsimonia (respecto a sencillez en su procedimiento); y se anticipan futuras líneas de actuación
Impact of amyloid-PET in daily clinical management of patients with cognitive impairment fulfilling appropriate use criteria
To evaluate the use of amyloid-positron emission tomography (PET) in routine clinical practice, in a selected population with cognitive
impairment that meets appropriate use criteria (AUC).
A multicenter, observational, prospective case-series study of 211patients from 2 level-3 hospitals who fulfilled clinical AUC for
amyloid-PET scan in a naturalistic setting. Certainty degree was evaluated using a 5-point Likert scale: 0 (very low probability); 1 (low
probability); 2 (intermediate probability); 3 (high probability); and 4 (practically sure), before and after amyloid PET. The treatment plan
was considered as cognition-specific or noncognition-specific.
Amyloid-PET was positive in 118 patients (55.9%) and negative in 93 patients (44.1%). Diagnostic prescan confidence according
amyloid-PET results showed that in both, negative and positive-PET subgroup, the most frequent category was intermediate
probability (45.7% and 55.1%, respectively). After the amyloid-PET, the diagnostic confidence showed a very different distribution,
that was, in the negative-PET group the most frequent categories are very unlikely (70.7%) and unlikely (29.3%), while in the positive-
PET group were very probable (57.6%) and practically sure (39%). Only in 14/211 patients (6.6%) the result of the amyloid-PET did
not influence the diagnostic confidence, while in 194 patients (93.4%), the diagnostic confidence improved significantly after amyloid-
PET results. The therapeutic intention was modified in 93 patients (44.1%). Specific treatment for Alzheimer disease was started,
before amyloid-PET, in 80 patients (37.9%).
This naturalistic study provides evidence that the implementation of amyloid-PET is associated with a significant improvement in
diagnostic confidence and has a high impact on the therapeutic management of patients with mild cognitive impairment fulfilled
clinical AUC
Multivariate explanatory model for sporadic carcinoma of the colon in Dukes’ stages I and IIa
We obtained before an explanatory model with six dependant variables: age of the patient, total cholesterol (TC), HDL cholesterol (HDL-C), VLDL cholesterol (VLDL-C), alkaline phosphatase (AP) and the CA 19.9 tumour marker. Our objective in this study was to validate the model by means of the acquisition of new records for an additional analysis.Ministerio de Educación y Cienci
Determining the distribution of triclosan and methyl triclosan in estuarine settings
We have developed a method for the analysis of two sewage-derived contaminants: triclosan (TCS), an antibacterial agent, and methyl triclosan (MTCS), a TCS metabolite. For solid samples (4 g), extraction and cleanup were integrated into the same step using pressurized liquid extraction (PLE) with in-cell-clean-up (1 g of florisil). The extraction was performed using dichloromethane at 100 °C, 1500 psi and 3 static extraction cycles of 5 min each. For water samples (100 mL), stir bar sorptive extraction–liquid desorption (SBSE–LD) was used. Bars were stirred for 10 h and analytes were later desorbed using acetonitrile. Finally, MTCS and a silylated derivative of TCS were determined by gas chromatography–mass spectrometry (GC–MS). Recovery experiments in water and sediments were performed and the results ranged from 67% to 78%. Limits of detection (LODs) were 5 ng L−1 for TCS and 1 ng L−1 for MTCS, in water samples, and 0.1 ng g−1 for TCS and MTCS in solid samples. The method was applied then to determine the levels of these compounds in the estuary of Guadalete River (SW Spain). TCS and MTCS concentrations up to 9.6 ng g−1 in sediments and 310 ng L−1 in water were measured. Their distribution was strongly influenced by the presence of wastewater sources, treated and untreated, along the sampling area, where maximum concentrations were detected. Highest values were reached in the water column during low tides as the water volume in the estuary becomes lower
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