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220 result(s) for "Ardila, D"
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A Brief History of Colour, the Environmental Impact of Synthetic Dyes and Removal by Using Laccases
The history of colour is fascinating from a social and artistic viewpoint because it shows the way; use; and importance acquired. The use of colours date back to the Stone Age (the first news of cave paintings); colour has contributed to the social and symbolic development of civilizations. Colour has been associated with hierarchy; power and leadership in some of them. The advent of synthetic dyes has revolutionized the colour industry; and due to their low cost; their use has spread to different industrial sectors. Although the percentage of coloured wastewater discharged by the textile; food; pharmaceutical; cosmetic; and paper industries; among other productive areas; are unknown; the toxic effect and ecological implications of this discharged into water bodies are harmful. This review briefly shows the social and artistic history surrounding the discovery and use of natural and synthetic dyes. We summarise the environmental impact caused by the discharge of untreated or poorly treated coloured wastewater to water bodies; which has led to physical; chemical and biological treatments to reduce the colour units so as important physicochemical parameters. We also focus on laccase utility (EC 1.10.3.2), for discolouration enzymatic treatment of coloured wastewater, before its discharge into water bodies. Laccases (p-diphenol: oxidoreductase dioxide) are multicopper oxidoreductase enzymes widely distributed in plants, insects, bacteria, and fungi. Fungal laccases have employed for wastewater colour removal due to their high redox potential. This review includes an analysis of the stability of laccases, the factors that influence production at high scales to achieve discolouration of high volumes of contaminated wastewater, the biotechnological impact of laccases, and the degradation routes that some dyes may follow when using the laccase for colour removal
Impact of Antibiotics as Waste, Physical, Chemical, and Enzymatical Degradation: Use of Laccases
The first traces of Tetracycline (TE) were detected in human skeletons from Sudan and Egypt, finding that it may be related to the diet of the time, the use of some dyes, and the use of soils loaded with microorganisms, such as Streptomyces spp., among other microorganisms capable of producing antibiotics. However, most people only recognise authors dating between 1904 and 1940, such as Ehrlich, Domagk, and Fleming. Antibiotics are the therapeutic option for countless infections treatment; unfortunately, they are the second most common group of drugs in wastewaters worldwide due to failures in industrial waste treatments (pharmaceutics, hospitals, senior residences) and their irrational use in humans and animals. The main antibiotics problem lies in delivered and non-prescribed human use, use in livestock as growth promoters, and crop cultivation as biocides (regulated activities that have not complied in some places). This practice has led to the toxicity of the environment as antibiotics generate eutrophication, water pollution, nutrient imbalance, and press antibiotic resistance. In addition, the removal of antibiotics is not a required process in global wastewater treatment standards. This review aims to raise awareness of the negative impact of antibiotics as residues and physical, chemical, and biological treatments for their degradation. We discuss the high cost of physical and chemical treatments, the risk of using chemicals that worsen the situation, and the fact that each antibiotic class can be transformed differently with each of these treatments and generate new compounds that could be more toxic than the original ones; also, we discuss the use of enzymes for antibiotic degradation, with emphasis on laccases.
GASPS-A Herschel Survey of Gas and Dust in Protoplanetary Disks: Summary and Initial Statistics
ABSTRACT We describe a large-scale far-infrared line and continuum survey of protoplanetary disk through to young debris disk systems carried out using the ACS instrument on the Herschel Space Observatory. This Open Time Key program, known as GASPS (Gas Survey of Protoplanetary Systems), targeted ∼250 young stars in narrow wavelength regions covering the [OI] fine structure line at 63 μm the brightest far-infrared line in such objects. A subset of the brightest targets were also surveyed in [OI]145 μm, [CII] at 157 μm, as well as several transitions of H2O and high-excitation CO lines at selected wavelengths between 78 and 180 μm. Additionally, GASPS included continuum photometry at 70, 100 and 160 μm, around the peak of the dust emission. The targets were SED Class II-III T Tauri stars and debris disks from seven nearby young associations, along with a comparable sample of isolated Herbig AeBe stars. The aim was to study the global gas and dust content in a wide sample of circumstellar disks, combining the results with models in a systematic way. In this overview paper we review the scientific aims, target selection and observing strategy of the program. We summarise some of the initial results, showing line identifications, listing the detections, and giving a first statistical study of line detectability. The [OI] line at 63 μm was the brightest line seen in almost all objects, by a factor of ∼10. Overall [OI]63 μm detection rates were 49%, with 100% of HAeBe stars and 43% of T Tauri stars detected. A comparison with published disk dust masses (derived mainly from sub-mm continuum, assuming standard values of the mm mass opacity) shows a dust mass threshold for [OI]63 μm detection of ∼10-5 M⊙. Normalising to a distance of 140 pc, 84% of objects with dust masses ≥10-5 M⊙ can be detected in this line in the present survey; 32% of those of mass 10-6-10-5 M⊙, and only a very small number of unusual objects with lower masses can be detected. This is consistent with models with a moderate UV excess and disk flaring. For a given disk mass, [OI] detectability is lower for M stars compared with earlier spectral types. Both the continuum and line emission was, in most systems, spatially and spectrally unresolved and centred on the star, suggesting that emission in most cases was from the disk. Approximately 10 objects showed resolved emission, most likely from outflows. In the GASPS sample, [OI] detection rates in T Tauri associations in the 0.3-4 Myr age range were ∼50%. For each association in the 5-20 Myr age range, ∼2 stars remain detectable in [OI]63 μm, and no systems were detected in associations with age >20 Myr. Comparing with the total number of young stars in each association, and assuming a ISM-like gas/dust ratio, this indicates that ∼18% of stars retain a gas-rich disk of total mass ∼1 MJupiter for 1-4 Myr, 1-7% keep such disks for 5-10 Myr, but none are detected beyond 10-20 Myr. The brightest [OI] objects from GASPS were also observed in [OI]145 μm, [CII]157 μm and CO J = 18 - 17, with detection rates of 20-40%. Detection of the [CII] line was not correlated with disk mass, suggesting it arises more commonly from a compact remnant envelope.
An incremental learning approach to prediction models of SEIRD variables in the context of the COVID-19 pandemic
Several works have proposed predictive models of the SEIRD (Susceptible, Exposed, Infected, Recovered, and Dead) variables to characterize the pandemic of COVID-19. One of the challenges of these models is to be able to follow the dynamics of the disease to make more precise predictions. In this paper, we propose an approach based on incremental learning to build predictive models of the SEIRD variables for the COVID-19 pandemic. Our incremental learning approach is a dynamic ensemble method based on a bagging scheme that allows the addition of new models or the updating of incremental models. The article proposes an incremental learning architecture composed of two components. The first component carries out an analysis of the interdependencies of the SEIRD variables and the second component is an incremental learning model that builds/updates the predictive models. The paper analyses the quality of the predictive models of our incremental learning approach using data of the COVID-19 from Colombia, and shows interesting results about the predictions of the SEIRD variables. These results are compared with an incremental learning approach based on random forests.
Multistage emplacement of a composite intrusion: magnetic fabric and zircon U–Pb age of the Parnamirim Pluton, NE Brazil
The advanced stages of the Neoproterozoic Brasiliano orogeny in western Gondwana led to significant crustal reworking and extensive peraluminous magmatism, with many plutons spatially associated with shear zones. This study applies a multi-methodological approach (airborne magnetic surveys, structural analysis, anisotropy of magnetic susceptibility analyses, and U–Pb zircon dating) to the Parnamirim Pluton (Central Domain of the Borborema Province, northeastern Brazil). The pluton is located between the West Pernambuco (E–W, dextral) and Parnamirim (NE–SW, sinistral) shear zones and consists of three main pulses (PP1, PP2, and CV) of peraluminous syenogranites to monzogranites, with magnetic susceptibility controlled by paramagnetic minerals. The NE–SW-striking magmatic, solid-state and magnetic foliations are steeply dipping to subvertical, reflecting syn- to post-emplacement deformation in response to strain caused by the regional deformation field. Magmatic to high-temperature solid-state microstructures dominate in the eastern PP1 unit, while high-strain and high-temperature solid-state deformation microstructures, characterized primarily by grain boundary migration recrystallization, show increasing strain in the western PP2 unit. Elongate country rock xenoliths indicate that pluton emplacement occurred initially by fracture propagation and evolved into sheet amalgamation. Pluton growth was controlled by NE–SW horizontal extension resulting from the combined motion of the West Pernambuco and Parnamirim shear zones, progressing westward, as constrained by the U–Pb zircon ages of PP1 (569 ± 1 Ma) and PP2 (559 ± 2 Ma). The age of the Parnamirim Pluton is similar to those of other granitoids in the Borborema Province and the  Benino-Nigerian Shield, indicating a large-scale magmatic and tectonic event. Graphical abstract Simplified model of the multi-stage intrusion and deformation of the Parnamirim Pluton. The schematic drawing illustrates: the sheet-like intrusion, consistent with the vertical foliation of the host rock (Salgueiro Complex); the initial intrusion took advantage of the foliation planes of the host rocks, facilitating the initial accommodation of the magmatic sheets which provides space and favorable thermal anisotropy for the advancement of the intrusion through the amalgamation of sheets; and the displacement of younger and hotter sheets to the west, favoring strain partitioning during the deformation of the pluton and allowing magmatic textures to be preserved in the eastern part. Additionally, the growth of the pluton was controlled by NE-SW horizontal extension resulting from the combined opposite motion of the West Pernambuco and Parnamirim shear zones, in response to NNW-SSE regional shortening. White arrows represent the transpressive context
Statistical Improvement of rGILCC 1 and rPOXA 1B Laccases Activity Assay Conditions Supported by Molecular Dynamics
Laccases (E.C. 1.10.3.2) are glycoproteins widely distributed in nature. Their structural conformation includes three copper sites in their catalytic center, which are responsible for facilitating substrate oxidation, leading to the generation of H2O instead of H2O2. The measurement of laccase activity (UL−1) results may vary depending on the type of laccase, buffer, redox mediators, and substrates employed. The aim was to select the best conditions for rGILCC 1 and rPOXA 1B laccases activity assay. After sequential statistical assays, the molecular dynamics proved to support this process, and we aimed to accumulate valuable insights into the potential application of these enzymes for the degradation of novel substrates with negative environmental implications. Citrate buffer treatment T2 (CB T2) (pH 3.0 ± 0.2; λ420nm, 2 mM ABTS) had the most favorable results, with 7.315 ± 0.131 UL−1 for rGILCC 1 and 5291.665 ± 45.83 UL−1 for rPOXA 1B. The use of citrate buffer increased the enzyme affinity for ABTS since lower Km values occurred for both enzymes (1.49 × 10−2 mM for rGILCC 1 and 3.72 × 10−2 mM for rPOXA 1B) compared to those obtained in acetate buffer (5.36 × 10−2 mM for rGILCC 1 and 1.72 mM for rPOXA 1B). The molecular dynamics of GILCC 1–ABTS and POXA 1B–ABTS showed stable behavior, with root mean square deviation (RMSD) values not exceeding 2.0 Å. Enzyme activities (rGILCC 1 and rPOXA 1B) and 3D model–ABTS interactions (GILCC 1–ABTS and POXA 1B–ABTS) were under the strong influence of pH, wavelength, ions, and ABTS concentration, supported by computational studies identifying the stabilizing residues and interactions. Integration of the experimental and computational approaches yielded a comprehensive understanding of enzyme–substrate interactions, offering potential applications in environmental substrate treatments.
Recombinant laccase rPOXA 1B real-time, accelerated and molecular dynamics stability study
Background Laccases (EC 1.10.3.2) are multi-copper oxidoreductases with great biotechnological importance due to their high oxidative potential and utility for removing synthetic dyes, oxidizing phenolic compounds, and degrading pesticides, among others. Methods A real-time stability study (RTS) was conducted for a year, by using enzyme concentrates from 3 batches (L1, L3, and L4). For which, five temperatures 243.15, 277.15, 298.15, 303.15, 308.15, and 313.15 K were assayed. Using RTS data and the Arrhenius equation, we calculated the rPOXA 1B accelerated stability (AS). Molecular dynamics (MD) computational study results were very close to those obtained experimentally at four different temperatures 241, 278, 298, and 314 K. Results In the RTS, 101.16, 115.81, 75.23, 46.09, 5.81, and 4.83% of the relative enzyme activity were recovered, at respective assayed temperatures. AS study, showed that rPOXA 1B is stable at 240.98 ± 5.38, 277.40 ± 1.32 or 297.53 ± 3.88 K; with t 1/2 values of 230.8, 46.2, and 12.6 months, respectively. Kinetic and thermodynamic parameters supported the high stability of rPOXA 1B, with an E d value of 41.40 KJ mol − 1 , a low variation of K M and V max , at 240.98 ± 5.38, and 297.53 ± 3.88 K, and ∆G values showing deactivation reaction does not occur. The MD indicates that fluctuations in loop, coils or loops with hydrophilic or intermediate polarity amino acids as well as in some residues of POXA 1B 3D structure, increases with temperature; changing from three fluctuating residues at 278 K to six residues at 298 K, and nine residues at 314 K. Conclusions Laccase rPOXA 1B demonstrated experimentally and computationally to be a stable enzyme, with t 1/2 of 230.8, 46.2 or 12.6 months, if it is preserved impure without preservatives at temperatures of 240.98 ± 5.38, 277.40 ± 1.32 or 297.53 ± 3.88 K respectively; this study could be of great utility for large scale producers.
Usable rainwater volume; results of a hydrological study conducted at the Universidad de Santander, Bucaramanga, Colombia
This study was carried out at the \"Universidad de Santander\", in Bucaramanga, Colombia, to calculate the volume of rainwater capturable from the roofs of five campus buildings, as the blueprints for these surfaces were available to obtain their areas. Roof areas were first obtained for the Guane, Motilón, Arhuaco, Chibcha and Yariguíes buildings, from which rainwater can be captured. Intensity, duration, and frequency curves from the \"Instituto de Hidrología, Meteorología y Estudios Ambientales\" were then used to calculate a design flow, yielding the diameter of the pipe necessary to evacuate the water captured. In addition, data from the \"Universidad de Santander\" meteorological station was evaluated to obtain monthly rainfall figures. The highest-yielding structure was the Motilón building, with approximately 80 m3 in the months of May and November, 2018, as this structure has the largest roof area, and the area experienced its greatest quantity of rain during these months. The total accumulation predicted by the study was 1837.96 m3 annually, sufficient to suggest the possibility of its use in restrooms, gardens, and floor washing at the \"Universidad de Santander\", Bucaramanga, Colombia. The volume of water calculated is variable on a yearly basis, and was estimated by means of one year of rainfall readings from the university's meteorological station. Hydraulic structures designed for the purpose of capturing this water would require a specific study, taking into account the records of other nearby meteorological stations, and making necessary provision for the storage of water in excess of expected volumes.
Development and Evaluation of the Chromatic Behavior of an Intelligent Packaging Material Based on Cellulose Acetate Incorporated with Polydiacetylene for an Efficient Packaging
Global growth of the food industry and the demand for new products with natural characteristics, safe conditions and traceability have driven researches for the development of technologies such as intelligent packaging, capable to fulfil those needs. Polydiacetylene (PDA) is a synthetic material that has been highlighted in research field as a sensor substance, which can be used to produce intelligent packaging capable to detect chemical or biochemical changes in foods and in their environment due to PDA’s color transition from blue to red. This work focused on the development and optimization of an intelligent packaging constituted of a polymeric matrix of cellulose acetate-based incorporated with PDA as the substance sensor. Cellulose acetate films (3% wt.) were developed by a casting method, and the amounts of triethyl citrate plasticizer (TEC) (0–25% wt. of cellulose-acetate) and PDA (0–60 mg) were analyzed to optimize the conditions for the best color transitioning at this study range. The compound amounts incorporated into polymeric matrices were established according to Central Composite Designs (CCD). Three more design variables were analyzed, such as the polymerization time of PDA under UV light exposition (0–60 min), pH values (4–11) and temperature exposure on the film (0–100 °C), important factors on the behavior of PDA’s color changing. In this study, film thickness and film color coordinates were measured in order to study the homogeneity and the color transitioning of PDA films under different pH and temperature conditions, with the purpose of maximizing the color changes through the optimization of PDA and TEC concentrations into the cellulose acetate matrix and the polymerization degree trigged by UV light irradiation. The optimal film conditions were obtained by adding 50.48 g of PDA and 10% of TEC, polymerization time of 18 min under UV light, at 100 °C ± 2 °C of temperature exposure. The changes in pH alone did not statistically influence the color coordinates measured at the analyzed ratio; however, variations in pH associated with other factors had a significant effect on visual color changes, and observations were described. PDA films were optimized to maximize color change in order to obtain a cheap and simple technology to produce intelligent packaging capable to monitor food products along the distribution chain in real time, improving the food quality control and consumer safety.
Obtaining biogas for use during construction of residential buildings
The present study examines the technical and economic feasibility of a biodigester to generate biogas from organic waste, such as human and food residues, generated during construction projects. Based on existing data and the scaling model selected, the quantity of such waste was estimated on a per-worker basis over a period of 30 days; yielding a daily average of 86 grams of food waste, 250 grams of stool, and 1.5 liters of urine. These estimates are scalable for the calculation of periods of greater or lesser duration. The data, variables, and calculations were analyzed using a technological tool developed for this study, such that other users or parties interested in the use of a biodigester for the management of organic wastes and biogas generation in construction projects can enter the relevant data for their project and generate scaling and cost data as an output. The use of a biodigester for construction projects is based on real-life experience in various sectors, for the most part in rural areas and domestic applications; while factors such as space, maintenance, and safety, among others, have hindered the use of this technology in the construction sector. Nevertheless, its implementation in new construction projects drives positive social, environmental, and economic impacts, as it reduces the volume of organic wastes for disposal, and substitutes for the use of fossil fuels. The latter results in a reduction of pollution, and improves the environment, with corresponding positive effects upon human health and wellbeing. It also represents an opportunity to reduce the cost of gas consumed during the construction process of residential buildings.