804 research outputs found
Cyanate Assimilation by the Alkaliphilic Cyanide-Degrading Bacterium Pseudomonas pseudoalcaligenes CECT5344: Mutational Analysis of the cyn Gene Cluster
The alkaliphilic bacterium Pseudomonas pseudoalcaligenes CECT5344 can grow with cyanate, cyanide, or cyanide-containing industrial residues as the sole nitrogen source, but the assimilation of cyanide and cyanate takes place through independent pathways. Therefore, cyanide degradation involves a chemical reaction between cyanide and oxaloacetate to form a nitrile that is hydrolyzed to ammonium by the nitrilase NitC, whereas cyanate assimilation requires a cyanase that catalyzes cyanate decomposition to ammonium and carbon dioxide. The P. pseudoalcaligenes CECT5344 cynFABDS gene cluster codes for the putative transcriptional regulator CynF, the ABC-type cyanate transporter CynABD, and the cyanase CynS. In this study, transcriptional analysis revealed that the structural cynABDS genes constitute a single transcriptional unit, which was induced by cyanate and repressed by ammonium. Mutational characterization of the cyn genes indicated that CynF was essential for cynABDS gene expression and that nitrate/nitrite transporters may be involved in cyanate uptake, in addition to the CynABD transport system. Biodegradation of hazardous jewelry wastewater containing high amounts of cyanide and metals was achieved in a batch reactor operating at an alkaline pH after chemical treatment with hydrogen peroxide to oxidize cyanide to cyanate
Hand classification of fMRI ICA noise components
We present a practical "how-to" guide to help determine whether single-subject fMRI independent components (ICs) characterise structured noise or not. Manual identification of signal and noise after ICA decomposition is required for efficient data denoising: to train supervised algorithms, to check the results of unsupervised ones or to manually clean the data. In this paper we describe the main spatial and temporal features of ICs and provide general guidelines on how to evaluate these. Examples of signal and noise components are provided from a wide range of datasets (3T data, including examples from the UK Biobank and the Human Connectome Project, and 7T data), together with practical guidelines for their identification. Finally, we discuss how the data quality, data type and preprocessing can influence the characteristics of the ICs and present examples of particularly challenging datasets
Fluvial geomorphological dynamics and land use changes: impact on the organic carbon stocks of soil and sediment
The drainage basin of the Turrilla river (SE of Spain) went through important land cover changes since 1950s; from mainly an agrarian scenario in 1956 to other depopulated and forested in 2015. This study analyzes the effects of land use changes on fluvial dynamics and their relationship with the organic carbon (OC) stock in fluvial sedimentary deposits as well as in the soil of the basin. Methods included a fluvial geomorphological analysis and a land use change analysis in combination with OC databases of soil and sediment. Results showed that the fluvial channel experienced important morphological changes related to different erosion processes and stabilization of fluvial deposits, induced by land use changes in the drainage area. The active channel decreased 63% in the study period, while bank erosion and gully erosion increased (34% and 21 %, respectively). Alluvial fans and alluvial plain were also extended (21% and 7 %, respectively) and alluvial bars were colonized by vegetation. Sediment was impoverished in OC compared to catchment soils (0.24 enrichment ratio sediment/soil). However the increase of OC stock (Mg ha-1) was very similar between soil (25 %) and sediment (23 %). The total reservoir of OC (Mg) increased 27% in sediments and 25% in the catchment soils. Results show the large influence of geomorphological dynamics on the OC reservoir at the catchment scale. A very high potential of fluvial sediments to increase OC sinks was observed, particularly in scenarios where the active channel is narrowed and the fluvial channel is encroached with vegetation, facilitating the input of OC in sediment. The potential of sediment to sequester organic carbon could be very useful in planning and management of fluvial sedimentary zones in climate change mitigation policies. © 2019, Universidad Austral de Chile. All rights reserved.Este estudio ha recibido apoyo financiero del proyecto DISECO (CGL2014-55405-R) del Plan Nacional de Ciencia del Ministerio de Economía y Competitividad de España, del proyecto SOGLO (P7/24 IAP BELSPO) del gobierno de Bélgica. AHM recibió apoyo financiero para una estancia en la Universidad Nacional de Córdoba (Argentina) del Banco de Santander mediante el Convenio Becas de Intercambio Latinoamérica (Programa ILA). CBF recibió apoyo financiero para dos estancias en el extranjero del programa Salvador de Madariaga 2017 (Ministerio de Educación, Cultura y Deporte, Gobierno de España) y del programa Jiménez de la Espada 2017 (Fundación Séneca, Agencia de Ciencia y Tecnología de la Región de Murcia). MAB fue parcialmente financiada por un contrato Juan de la Cierva-Incorporación (Ref: IJCI-2015-23500). Todas estas estancias permitieron el trabajo continuado en la redacción de este artículo
Modelling the distribution of white matter hyperintensities due to ageing on MRI images using Bayesian inference
White matter hyperintensities (WMH), also known as white matter lesions, are localised white matter areas that appear hyperintense on MRI scans. WMH commonly occur in the ageing population, and are often associated with several factors such as cognitive disorders, cardiovascular risk factors, cerebrovascular and neurodegenerative diseases. Despite the fact that some links between lesion location and parametric factors such as age have already been established, the relationship between voxel-wise spatial distribution of lesions and these factors is not yet well understood. Hence, it would be of clinical importance to model the distribution of lesions at the population-level and quantitatively analyse the effect of various factors on the lesion distribution model.
In this work we compare various methods, including our proposed method, to generate voxel-wise distributions of WMH within a population with respect to various factors. Our proposed Bayesian spline method models the spatio-temporal distribution of WMH with respect to a parametric factor of interest, in this case age, within a population. Our probabilistic model takes as input the lesion segmentation binary maps of subjects belonging to various age groups and provides a population-level parametric lesion probability map as output. We used a spline representation to ensure a degree of smoothness in space and the dimension associated with the parameter, and formulated our model using a Bayesian framework.
We tested our algorithm output on simulated data and compared our results with those obtained using various existing methods with different levels of algorithmic and computational complexity. We then compared the better performing methods on a real dataset, consisting of 1000 subjects of the UK Biobank, divided in two groups based on hypertension diagnosis. Finally, we applied our method on a clinical dataset of patients with vascular disease.
On simulated dataset, the results from our algorithm showed a mean square error (MSE) value of , which was lower than the MSE value reported in the literature, with the advantage of being robust and computationally efficient. In the UK Biobank data, we found that the lesion probabilities are higher for the hypertension group compared to the non-hypertension group and further verified this finding using a statistical t-test. Finally, when applying our method on patients with vascular disease, we observed that the overall probability of lesions is significantly higher in later age groups, which is in line with the current literature
Motivational analysis comparing three contexts of physical activity
El estudio analizó las diferencias motivacionales entre estudiantes de educación física, deportistas y practicantes de ejercicio físico no competitivo. Además, examinó el poder de predicción del clima motivacional percibido y de los tipos de motivación sobre la propensión a la experiencia autotélica en los tres contextos. Se utilizaron tres muestras diferentes: 895 estudiantes de educación física, 413 deportistas y 727 practicantes de ejercicio físico no competitivo. El análisis de regresión mostró que el clima tarea y la motivación intrínseca predijeron positivamente y de forma significativa la experiencia autotélica en los tres contextos, de ahí la importancia de fomentar este tipo de clima motivacional. No obstante, los resultados han mostrado diferencias motivacionales entre los contextos de educación física, deporte competitivo y ejercicio físico no competitivo. Los resultados son discutidos en relación al diferente carácter competitivo/lúdico y voluntariedad/obligatoriedad que rodea a la práctica física en cada uno de los contextos comparados en este estudioThe study analyzed the motivational differences between physical education students, athletes and non-competitive exercisers. Furthermore, the predictive power of perceived motivational climate and types of motivation on the autotelic experience propensity in the three contexts was examined. Three different samples were used: 895 physical education students, 413 athletes and 727 non-competitive exercisers. Regression analysis showed that task-involving climate and intrinsic motivation positively and significantly predicted the autotelic experience in the three contexts, hence the importance of promoting this type of motivational climate. However, the results revealed that there were motivational differences between the contexts of physical education, competitive sports and non-competitive exercise. The results are discussed in relation to the different features (e.g. competitive, recreational, voluntary or obligatory) surrounding the physical activity in each of the contexts compared in this studyLa realización de este trabajo fue posible gracias al proyecto de investigación "Evaluación y análisis comparativo de factores motivacionales relacionados con la adherencia a la práctica en diferentes contextos físico-deportivos: Educación física, deporte de competición y actividad física no competitiva" (Ref. DEP2007-73201-C03/ACTI), financiado por el Ministerio de Ciencia e Innovación de Españ
Management of the COPD patient with comorbidities: an experts recommendation document
Background: Chronic obstructive pulmonary disease (COPD) is associated with multiple comorbidities, which impact negatively on patients and are often underdiagnosed, thus lacking a proper management due to the absence of clear guidelines.
Purpose: To elaborate expert recommendations aimed to help healthcare professionals to provide the right care for treating COPD patients with comorbidities.
Methods: A modified RAND-UCLA appropriateness method consisting of nominal groups to draw up consensus recommendations (6 Spanish experts) and 2-Delphi rounds to validate them (23 Spanish experts) was performed.
Results: A panel of Spanish internal medicine experts reached consensus on 73 recommendations and 81 conclusions on the clinical consequences of the presence of comorbidities. In general, the experts reached consensus on the issues raised with regard to cardiovascular comorbidity and metabolic disorders. Consensus was reached on the use of selective serotonin reuptake inhibitors in cases of depression and the usefulness of referring patients
with anxiety to respiratory rehabilitation programmes. The results also showed consensus on the usefulness of investigating the quality of sleep, the treatment of pain with opioids and the evaluation of osteoporosis by lateral chest radiography.
Conclusion: This study provides conclusions and recommendations that are intended to improve the management of the complexity of patients with COPD and important comorbidities, usually excluded from clinical trials.
Keywords: chronic obstructive pulmonary disease, COPD, comorbidities, modified RANDUCLA, Delphi techniqu
Puntos de servicio en aseos públicos para minimizar y equilibrar los tiempos de espera de hombres y mujeres
The article raises the issue of the queues that usually appear in the ladies toilets in contrast to the fluidity with which gentlemen can access theirs, and points that this situation is only due to bad dimensioning of the toilets and thus that the problem has an easy solution. After describing and parameterizing the queuing forming processes in ladies and gentlemen toilets, a simulation program is used to analyze in each case the influence of the number of service points in waiting times. Finally, the results obtained are used to give recommendations in order to balance the waiting times of ladies and gentlemen while keeping them below reasonable levels.Se plantea el problema de las colas que se presentan habitualmente en los aseos de señoras en contraste con la fluidez con que se accede a los de caballeros, considerando que esta situación tiene solución ya que es sólo debida al mal dimensionado de los aseos. Tras describir y parametrizar los procesos de formación de colas en los aseos de señoras y de caballeros, se utiliza un programa de simulación para analizar en cada caso la influencia del número de puntos de servicio en los tiempos de espera. Finalmente, de acuerdo con los resultados obtenidos, se realizan unas recomendaciones para equilibrar los tiempos de espera, manteniéndolos en ambos casos por debajo de unos valores razonables
Exploring anaerobic environments for cyanide and cyano-derivatives microbial degradation
Cyanide is one of the most toxic chemicals for living organisms described so far. Its toxicity is mainly based on the high affinity
that cyanide presents toward metals, provoking inhibition of essential metalloenzymes. Cyanide and its cyano-derivatives are
produced in a large scale by many industrial activities related to recovering of precious metals in mining and jewelry, coke
production, steel hardening, synthesis of organic chemicals, and food processing industries. As consequence, cyanide-containing
wastes are accumulated in the environment becoming a risk to human health and ecosystems. Cyanide and related compounds,
like nitriles and thiocyanate, are degraded aerobically by numerous bacteria, and therefore, biodegradation has been offered as a
clean and cheap strategy to deal with these industrial wastes. Anaerobic biological treatments are often preferred options for
wastewater biodegradation. However, at present very little is known about anaerobic degradation of these hazardous compounds.
This review is focused on microbial degradation of cyanide and related compounds under anaerobiosis, exploring their potential
application in bioremediation of industrial cyanide-containing wastes
Assimilation of cyanide and cyano-derivatives by Pseudomonas pseudoalcaligenes CECT5344: from omic approaches to biotechnological applications
Mining, jewellery and metal-processing industries use cyanide for extracting gold and other valuable metals, generating large amounts of highly toxic wastewater. Biological treatments may be a clean alternative under the environmental point of view to the conventional physical or chemical processes used to remove cyanide and related compounds from these industrial effluents. Pseudomonas pseudoalcaligenes CECT5344 can grow under alkaline conditions using cyanide, cyanate or different nitriles as the sole nitrogen source, and is able to remove up to 12 mM total cyanide from a jewellery industry wastewater that contains cyanide free and complexed to metals. Complete genome sequencing of this bacterium has allowed the application of transcriptomic and proteomic techniques, providing a holistic view of the cyanide biodegradation process. The complex response to cyanide by the cyanotrophic bacterium P. pseudoalcaligenes CECT5344 and the potential biotechnological applications of this model organism in the bioremediation of cyanide-containing industrial residues are reviewed
Bioremediation of cyanide-containing wastes: The potential of systems and synthetic biology for cleaning up the toxic leftovers from mining
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