Abstract
We introduce the Automatic Learning for the Rapid Classification of Events (ALeRCE) broker, an astronomical alert broker designed to provide a rapid and self-consistent classification of ...large etendue telescope alert streams, such as that provided by the Zwicky Transient Facility (ZTF) and, in the future, the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST). ALeRCE is a Chilean-led broker run by an interdisciplinary team of astronomers and engineers working to become intermediaries between survey and follow-up facilities. ALeRCE uses a pipeline that includes the real-time ingestion, aggregation, cross-matching, machine-learning (ML) classification, and visualization of the ZTF alert stream. We use two classifiers: a stamp-based classifier, designed for rapid classification, and a light curve–based classifier, which uses the multiband flux evolution to achieve a more refined classification. We describe in detail our pipeline, data products, tools, and services, which are made public for the community (see
https://alerce.science
). Since we began operating our real-time ML classification of the ZTF alert stream in early 2019, we have grown a large community of active users around the globe. We describe our results to date, including the real-time processing of 1.5 × 10
8
alerts, the stamp classification of 3.4 × 10
7
objects, the light-curve classification of 1.1 × 10
6
objects, the report of 6162 supernova candidates, and different experiments using LSST-like alert streams. Finally, we discuss the challenges ahead in going from a single stream of alerts such as ZTF to a multistream ecosystem dominated by LSST.
New metal/polymer composite filaments for fused deposition modeling (FDM) processes were developed in order to observe the thermo-mechanical properties of the new filaments. The acrylonitrile ...butadiene styrene (ABS) thermoplastic was mixed with copper and iron particles. The percent loading of the metal powder was varied to confirm the effects of metal particles on the thermo-mechanical properties of the filament, such as tensile strength and thermal conductivity. The printing parameters such as temperature and fill density were also varied to see the effects of the parameters on the tensile strength of the final product which was made with the FDM process. As a result of this study, it was confirmed that the tensile strength of the composites is decreased by increasing the loading of metal particles. Additionally, the thermal conductivity of the metal/polymer composite filament was improved by increasing the metal content. It is believed that the metal/polymer filament could be used to print metal and large-scale 3-dimensional (3D) structures without any distortion by the thermal expansion of thermoplastics. The material could also be used in 3D printed circuits and electromagnetic structures for shielding and other applications.
High hydrostatic pressure stabilized galactose oxidase (GaOx) at 70.0–80.0°C against thermal inactivation. The pseudo‐first‐order rate constant of inactivation kinact decreased by a factor of 8 at ...80°C and by a factor of 44 at 72.5°C. The most pronounced effect of pressure was at the lowest studied temperature of 70.0°C with an activation volume of inactivation ΔV‡ of 78.8 cm3 mol−1. The optimal pressure against thermal inactivation was between 200 and 300 MPa. Unlike other enzymes, as temperature increased the ΔV‡ of inactivation decreased, and as pressure increased the activation energy of inactivation Eai increased. Combining the results for GaOx with earlier research on the pressure‐induced stabilization of other enzymes suggests that ΔV‡ of inactivation correlates with the total molar volume of cavities larger than ~100 Å3 in enzyme monomers for enzymes near the optimal pH and whose thermal unfolding is not accompanied by oligomer dissociation.
High hydrostatic pressure stabilized galactose oxidase (GaOx) against thermal inactivation. The activation energy of inactivation of GaOx and other oxidases correlates with the total molar volume of cavities larger than ~100 Å3 per monomer for enzymes near the optimal pH and whose thermal unfolding is not accompanied by oligomer dissociation.
Metabolomic analysis in food science: a review Cevallos-Cevallos, Juan M.; Reyes-De-Corcuera, José I.; Etxeberria, Edgardo ...
Trends in food science & technology,
12/2009, Letnik:
20, Številka:
11
Journal Article
Recenzirano
Metabolomics has emerged as an important tool in many disciplines such as human diseases and nutrition, drug discovery, plant physiology and others. In food science, metabolomics has recently risen ...as a tool for quality, processing and safety of raw materials and final products. This article discusses the latest advances in food metabolomics from the discriminative, predictive, and informative approaches, as well as the typical methods used at each step of the metabolomic analysis.
To determine the frequency and nature of leptomeningeal contrast enhancement in multiple sclerosis (MS) via in vivo 3-tesla postcontrast T2-weighted, fluid-attenuated inversion recovery (FLAIR) MRI ...and 7-tesla postmortem MRI-pathology correlation.
Brain MRI, using the postcontrast T2-weighted, FLAIR technique, was prospectively collected in 299 MS cases and 37 age-matched neurologically healthy controls. Expert raters evaluated focal gadolinium enhancement in the leptomeningeal compartment. Two progressive MS cases came to autopsy after in vivo MRI characterization. Pathologic and immunohistochemical examination assessed the association of enhancement with leptomeningeal inflammation and adjacent cortical demyelination.
Focal contrast enhancement was detected in the leptomeningeal compartment in 74 of 299 MS cases (25%) vs 1 of 37 neurologically healthy controls (2.7%; p = 0.001). Enhancement was nearly twice as frequent (p = 0.009) in progressive MS (39/118 cases, 33%) as in relapsing-remitting MS (35/181, 19%). Enhancing foci generally remained stable throughout the evaluation period (up to 5.5 years). Pathology showed perivascular lymphocytic and mononuclear infiltration in the enhancing areas in association with flanking subpial cortical demyelination.
Leptomeningeal contrast enhancement occurs frequently in MS and is a noninvasive, in vivo marker of inflammation and associated subpial demyelination. It might therefore enable testing of new treatments aimed at eliminating this inflammation and potentially arresting progressive MS.
Food additives such as titanium dioxide (E171), iron oxides and hydroxides (E172), silver (E174), and gold (E175) are highly used as colorants while silicon dioxide (E551) is generally used as ...anticaking in ultra-processed foodstuff highly used in the Western diets. These additives contain nanosized particles (1–100 nm) and there is a rising concern since these nanoparticles could exert major adverse effects due to they are not metabolized but are accumulated in several organs. Here, we analyze the evidence of gastrotoxicity, hepatotoxicity and the impact of microbiota on gut-brain and gut-liver axis induced by E171, E172, E174, E175 and E551 and their non-food grade nanosized counterparts after oral consumption. Although, no studies using these food additives have been performed to evaluate neurotoxicity or alterations in animal behavior, their non-food grade nanosized counterparts have been associated with stress, depression, cognitive and eating disorders as signs of animal behavior alterations. We identified that these food additives induce gastrotoxicity, hepatotoxicity and alterations in gut microbiota and most evidence points out oxidative stress as the main mechanism of toxicity, however, the role of oxidative stress as the main mechanism needs to be explored further.
The evidence of toxicity induced by oral consumption of E171, E172, E174, E175, E551 and their nanoparticles counterparts. Oral consumption of titanium dioxide (E171), iron oxide and hydroxides (E172), silver (E174), gold (E175) and silicon dioxide (E551) causes several signs of toxicity in the gastrointestinal tissues and liver (blue bullets) and oxidative stress in both (red bullets). However, the evidence of oxidative stress is restricted to description of increase in reactive oxygen species (ROS), decrease in antioxidant enzymes (catalase, superoxide dismutase and, glutathione reductase) and oxidative damage to biomolecules such as lipids, proteins and DNA. On the other hand, there is no available evidence of neurotoxicity of these five food-additives, however, their nanosized counterparts used in animal experimental models have induced clear signs of neurotoxicity and alterations in the behavior but scarce evidence of oxidative stress has been associated with. Display omitted
•E171, E172, E174, E175 and E551 food additives contain a fraction of nanoparticles.•E171, E172, E174, E175 and E551 are accumulated inducing gastro and hepatotoxicity.•Microbiome is altered by oral consumption of E171, E172, E174, E175 and E551.•Neurotoxicity and alterations in behavior and cognition are potentials effects.•Oxidative stress is important in their toxicity but further studies are needed.
Heteromerization of G-protein-coupled receptors is an important event as they integrate the actions of extracellular signals to give heteromer-selective ligand binding and signaling, opening new ...avenues in the development of potential drug targets in pharmacotherapy. The aim of the present paper was to check for cannabinoid CB1–GPR55 receptor heteromers in the central nervous system (CNS), specifically in striatum. First, a direct interaction was demonstrated in cells transfected with the cDNA for the human version of the receptors, using bioluminescence resonance energy transfer and in situ proximity ligation assays (PLA). In the heterologous system, a biochemical fingerprint consisting on cross-antagonism in ERK1/2 phosphorylation was detected. The cross-antagonism was also observed on GPR55-mediated NFAT activation. Direct identification of GPR55 receptors in striatum is here demonstrated in rat brain slices using a specific agonist. Moreover, the heteromer fingerprint was identified in these rat slices by ERK1/2 phosphorylation assays whereas PLA assays showed results consistent with receptor–receptor interactions in both caudate and putamen nuclei of a non-human primate. The results indicate not only that GPR55 is expressed in striatum but also that CB1 and GPR55 receptors form heteromers in this specific CNS region.
Display omitted
•GPR55 is expressed in the striatum.•Cannabinoid CB1 and GPR55 receptors form heteromers in the CNS.•Rat striatal slices display the CB1R–GPR55 heteromer fingerprint.•Non-human primate striatum displays CB1R–GPR55 heteromers.
In the orange juice industry, pulp (ruptured juice sacs) is separated from the juice after extraction and pasteurized separately before blending back with juice or sold for other food applications. ...However, pulp is not always pasteurized immediately after extraction and the flow behavior is affected by endogenous pectinmethylesterase (PME). This is particularly important because of the high power required to pump orange pulp in industrial pasteurizers. This study characterized the effect of PME on the flow behavior of citrus pulp during storage at 4 °C using rotational rheometry and during pulp storage at 22 °C using capillary rheometry. PME activity was 0.011 ± 0.001 PEU for the pulp used in rotational rheometry and 0.030 ± 0.002 PEU for the pulp used in capillary rheometry. Rotational rheometry was used to assess the effect of PME on the Power Law parameters at shear rates (γ̇) below those that cause slip. There were no significant differences among storage time on the flow behavior index (n). However, the consistency coefficient (K) increased with storage time. Significant differences were found after 12‐hr storage increasing from 120 ± 30 Pa·sn to 160 ± 15 Pa·sn (16.7%) after 24 hr. Capillary rheomtery was used to assess the effect of PME on the pressure drop in a flow system. Significant differences were found at or after 12‐hr storage. The mean pressure drop increased by 34% after 24 hr, for a flow rate of 50 × 10−6 m3/s (0.8 GPM) in an 8.9‐m long (29.2 ft), 0.022‐m (1‐in) diameter pipe.
Practical Application
Design and optimization of processing equipment and industrial handling systems of orange pulp require detailed knowledge of its rheological (flow) properties. Citrus pulp is rich in pectinmethylesterase, an enzyme that causes thickening of the product when not inactivated during pasteurization. Understanding how fast PME affects the flow properties of orange pulp is important for citrus processors to decide how long pulp can be stored before pasteurizing it.
The characterization of the rheological properties of orange pulp under typical processing temperatures is needed for the design and optimization of orange pulp processing systems. The flow of orange ...pulp produced slip at shear rates at ∼1 to 5 s−1. Rotational rheometry revealed that the flow behavior of orange pulp before slip occurrence followed the Power Law model for concentrations of ∼500 to 800 g/L at 4 to 80 °C. The consistency coefficient (K) ranged from 33 to 234 Pa·sn and the flow behavior index n ranged from 0.18 to 0.24. Both, K and n decreased with temperature. While K fitted well an Arrhenius‐like model, n best fitted a linear model. As concentration increased K increased linearly, while n was not significantly (P > 0.05) affected. The flow without slip was calculated using the Power Law parameters from rotational rheometry and the wall shear stress (σw) from capillary rheometry for the experimental flow rates. This allowed calculating the corrected slip coefficient βc and obviated the need for pipes with multiple diameters. βc decreased by one order of magnitude when temperature increased from 4 to 50 °C when σw was 0.1 kPa. The effect was exacerbated with increased flow rate. Similarly, βc increased by about one order of magnitude when pulp concentration increased from ∼550 to 850 g/L at 80 °C. The increase in βc with temperature indicated that the effect of temperature in the consistency of the bulk was different from its effect on the consistency of the liquid phase near the pipe wall.
Practical Application
Design and optimization of processes equipment and industrial handling systems of orange pulp require detailed knowledge of their rheological (flow) properties. Citrus pulp like fruit pastes and purees produce less friction than one would anticipate when they flow because the liquid fraction acts as a lubricant. This study presents an original method for such characterization and shows that wall slip is greatly affected by temperature and concentration.
Fifty-five years have passed and more than 100,000 articles have been published since the first report of an electrochemical enzyme biosensor. However, very few biosensors have reached practical ...application and commercialization. The bulk of the research effort has been on increasing sensitivity and selectivity. In contrast, the number of publications dealing with stability or stabilization of enzyme biosensors is very small. Here, we critically review enzyme stabilization strategies as well as the progress that has been done in the past 20 years with respect to enzyme biosensor stabilization. Glucose oxidase, lactate oxidase, alcohol oxidase, and xanthine oxidase are the focus of this review because of their potential applications in food. The inconsistency in reporting biosensor stability was identified as a critical hurdle to research progress in this area. Fundamental questions that remain unanswered are outlined.
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