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Building a representative model of a complex dynamical system from empirical evidence remains a highly challenging problem. Classically, these models are described by systems of differential equations that depend on parameters that need to be optimized by comparison with data. In this tutorial, we introduce the most common multi-parameter estimation techniques, highlighting their successes and limitations. We demonstrate how to use the adjoint method, which allows efficient handling of large systems with many unknown parameters, and present prototypical examples across several fields of physics. Our primary objective is to provide a practical introduction to adjoint optimization, catering for a broad audience of scientists and engineers. Multiple parameter estimation techniques are employed to empirically validate theoretical propositions regarding complex systems by discerning relevant free parameters from often scarce experimental data. In this tutorial, the authors provide a beginner's guide to parameter estimation via adjoint optimization, and show its efficiency in prototypical problems across different fields of physics. [ABSTRACT FROM AUTHOR]

Sposisorium reilianum is the causal agent of corn ear smut disease. Eleven genes have been identified in its genome that code for enzymes that could constitute its hemicellulosic system, three of which have been associated with two Endo-β-1,4-xylanases and one with α-L-arabinofuranosidase activity. In this study, the native protein extracellular with β-xylosidase activity, called SRBX1, produced by this basidiomycete was analyzed by performing production kinetics and its subsequent purification by gel filtration. The enzyme was characterized biochemically and sequenced. Finally, its synergism with Xylanase SRXL1 was determined. Its activity was higher in a medium with corn hemicellulose and glucose as carbon sources. The purified protein was a monomer associated with the sr16700 gene, with a molecular weight of 117 kDa and optimal activity at 60 °C in a pH range of 4–7, which had the ability to hydrolyze the ρ-nitrophenyl β-D-xylanopyranoside and ρ-Nitrophenyl α-L-arabinofuranoside substrates. Its activity was strongly inhibited by silver ions and presented Km and Vmax values of 2.5 mM and 0.2 μmol/min/mg, respectively, using ρ-nitrophenyl β-D-xylanopyranoside as a substrate. The enzyme degrades corn hemicellulose and birch xylan in combination and in sequential synergism with the xylanase SRXL1. [ABSTRACT FROM AUTHOR]

This work shows a technical-economic procedure to determine the adapted network in a low voltage (LV) residential electrical system with photovoltaic distributed generation (PVDG). A network is adapted when it is designed to minimize the total fixed and variable costs and optimize the equipment to adequately satisfy the demand (both the current demand and its expected growth). The study will consider that the decision to install PVDG is exogenous. The method is based on the concept of Hosting Capacity (HC). This paper analyzes four typical LV networks in the city of Buenos Aires, Argentina. A statistical power flow solves the networks. We take the following statistical variables: residential load, PV penetration, PV power, and location. We obtain the statistical HC for each network, and the HC is used to carry out the technical-economic study of the network. Finally, we establish the adapted network for each level of penetration. The results show that, without PVDG penetration, there are different network options with different costs per km2. When PVDG penetration increases, the networks with the lowest cost per km2 are discarded (due to their FCE), and only the networks with the highest cost per km2 survive. Once 70% penetration of PVDG has been exceeded, none of the studied networks is considered an option.. [ABSTRACT FROM AUTHOR]

The aims of this study were to, first, determine the intracellular aminopeptidase activity (APEi) and second, purify and biochemically characterize one intracellular aminopeptidase enzyme from the phytopathogen fungus Sporisorium reilianum (psrAPEi), the causal agent of head smut in corn. The fungus produced APEi activity in all media cultures evaluated. The psrAPEi was purified by a procedure that involved ammonium sulfate fractionation and four chromatographic steps using an FPLC system (Fast Protein Liquid Chromatography). Results showed an estimated molecular mass of 52.2 kDa. Enzymatic activity was optimal at pH 7.0 and 35 °C and was inhibited by EDTA-Na2, 1,10-phenanthroline, bestatin, and PMSF. This aminopeptidase showed a preference for leucine, arginine, and lysine at the N-position. The Km and Vmax values were 3.72 μM and 188.0 μmol/min, respectively, for l-lysyl-4-nitroanilide. This is the first study to report on intracellular aminopeptidase activity in S. reilianum and the purification and characterization of an intracellular metallo-serine-aminopeptidase (psrAPEi). [ABSTRACT FROM AUTHOR]

The present study demonstrates that Sporisorium reilianum , a phytopathogenic fungus of corn, produces intracellular xylanolytic activity during submerged fermentation. Production reached its highest levels in a medium containing glucose, corn hemicellulose and yeast extract. An intracellular xylanase was purified by a process that included precipitation with ammonium sulfate, ion exchange chromatography and gel filtration. Optimal pH and temperature values were 5.0 and 60 °C, respectively. The enzyme showed activity through a broad pH range. The molecular weights of pure xylanase were 36 and 37 kDa, determined by SDS PAGE and gel filtration, respectively. K m and V max were 0.160 mg/mL and 1.564 μmol/min/mg, respectively, on a substrate of birchwood xylan. SDS, EDTA, β-Mercaptoethanol, Tween 80, Triton and Mn2+ and Ca2+ strongly inhibited activity. The purified enzyme hydrolyzed xylan, releasing xylotriose and xylobiose. Sequence protein analysis showed 95% similarity with the theoretical protein encoded by the sr14403 gene of S. reilianum , which encodes a putative endo-β-1,4-xylanase. The enzyme is an isoform of the extracellular xylanase SRXL1 of this basidiomycete. • Sporisorium reilianum showed intracellular xylanolytic activity. • An intracellular xylanase from S. reilianum was purified with a molecular weight of 37 kDa. • The xylanase intracellular is an isoform of the xylanase extracellular SRXL1. • Using birch xylan as substrate the Km = 0.160 mg/mL and Vmax = 1.564 μmol/mL/min. • The enzyme hydrolyzed the xylan, releasing xylotetrose, xylotriose and xylobiose. [ABSTRACT FROM AUTHOR]

The aim of this study was to design and validate a diagrammatic scale to estimate the severity of gray mold induced by Botrytis cinerea in pomegranate cultivation. A total of 120 healthy and diseased fruits with varying degrees of affliction were collected from orchards with active production located in the municipalities of Chilcuahutla and Taxquillo in the state of Hidalgo, Mexico (20° 18' 11" N, 99° 14' 23" W, 20° 32' 01" N, 99° 20' 03" W, respectively). From these, 60 were selected to determine the severity percentage, according to a 6-class scale (Class 0 = 0%, Class 1 = >0% - 5% - 10%, Class 2 = >10% - 25% - 50%, Class 3 = >50% - 75% - 85%, Class 4 = >85% - 90% - 95%, and Class 5 = >95% - 100%), using the 2LOG software. With the obtained data, representative images were selected to build the diagrammatic scale using Adobe Photoshop. The accuracy (r2), precision (ß0), and reproducibility (ß1) were verified by simple linear regression applied to the data obtained by 12 evaluators with and without experience in the observation of plant diseases. As a result, values of r2 of 0.42 and 0.85 were obtained, without and with the use of the scale, respectively, which confirmed that this tool is suitable to evaluate the severity of the disease accurately and reproducibly. [ABSTRACT FROM AUTHOR]

The extracellular protease APSm1 was purified to homogeneity from Stenocarpella maydis that was grown in acidic minimal media with glucose and ammonium sulfate. The purification procedure consisted of ion exchange chromatography coupled to an FPLC (Fast Protein Liquid Chromatography) system, resulting in a 15.3% recovery and a 2.3-fold increase in specific activity. The molecular weight of the purified enzyme was estimated to be 56.8 kDa by SDS–PAGE. Enzymatic activity toward hemoglobin was optimal at pH 2.0 and at 25 °C. The effects of six protease inhibitors on APSm1 activity were tested. Pepstatin A inhibited APSm1 activity, as the protein is in fact an aspartyl protease. The pure enzyme degraded hemoglobin, albumin and proteins obtained from corn germ at pH 3 but did not have any milk-clotting activities. The Km and V max values obtained were 0.514 mg/mL and 0.222 μmol/min, respectively, using hemoglobin as the substrate. This work is the first to report the purification of a secreted aspartyl protease from S. maydis . [ABSTRACT FROM AUTHOR]

Cheesemaking is one of the most important industries in Mexico. Among all the Mexican cheeses, fresh cheeses are the most popular and most consumed cheese in Mexico and Latin America. However, in Mexico fresh cheese is frequently made with unpasteurized milk and sold in public markets. This may increase the risk for contamination of dairy products with pathogenic bacteria. The presence of multidrug-resistant pathogenic bacteria in food is an important public health concern. Diarrheagenic Escherichia coli pathotypes (DEPs) are foodborne bacteria. This study investigated the presence of indicator bacteria and multidrug-resistant DEPs in fresh cheeses. A total of 120 fresh cheese samples were collected from public markets in the city of Pachuca, Mexico. The samples were analyzed for presence of fecal coliforms (FC), E. coli, and antibiotic resistant DEPs. FC and E. coli were analyzed using the most-probable-number technique. DEPs were identified using two multiplex PCR methods. Susceptibility to 16 antibiotics was tested for the isolated DEPs strains by the standard assay. The frequency of FC, E. coli, and DEPs in the cheese samples was 50, 40, and 19%, respectively. The identified DEPs included Shiga toxin–producing E. coli (STEC; 8%), enteropathogenic E. coli (EPEC; 6%), and enterotoxigenic E. coli (ETEC; 5%). All isolated strains exhibited resistance to at least five antibiotics. One, one, two, and three STEC strains were resistant to 14, 12, 11, and 10 antibiotics, respectively. One strain of EPEC was resistant to 11 antibiotics, three EPEC strains to 9, and one strain to 7. One, one, and two strains of ETEC were resistant to 10, 8, and 7 antibiotics, respectively. The results of the present study indicate that fresh cheeses made with unpasteurized milk could be a risk for consumers, both for native people and visitors to Mexico. [ABSTRACT FROM AUTHOR]

This study aimed to optimize an extruded aquafeed for Oreochromis niloticus (Nile tilapia) using moringa as a partial protein source. Response surface methodology (RSM) with a Rotatable Central Composite Design (CCRD) was employed to evaluate the four factors influence: sardine meal (28.5–39.25%), moringa flour (34.85–45.60%), temperature (110–140°C) and moisture content (13–17%) on aquafeed's physicochemical characteristics: expansion index (EI), bulk density, water solubility index (WSI), water absorption index (WAI), hardness and buoyancy. Numerical optimization identified 100 potential diets, of which four were selected and met the criteria for high WSI (11–14%), low hardness (22–32 N) and 100% buoyancy. The best diet consisted of 31.19% sardine meal and 42.91% moringa flour, processed at 132.5°C and 16% moisture, presenting 13.68% WSI, full buoyancy, 29.63 N hardness, 36.33% protein, 10.71% lipids, and 31.36% carbohydrates, applicable to fingerling O. niloticus. [ABSTRACT FROM AUTHOR]

A key behavior observed during morphogenesis, wound healing, and cancer invasion is that of collective and coordinated cellular motion. Hence, understanding the different aspects of such coordinated migration is fundamental for describing and treating cancer and other pathological defects. In general, individual cells exert forces on their environment in order to move, and collective motion is coordinated by cell–cell adhesion‐based forces. However, this notion ignores other mechanisms that encourage cellular movement, such as pressure differences. Here, using model tumors, it is found that increased pressure drove coordinated cellular motion independent of cell–cell adhesion by triggering cell swelling in a soft extracellular matrix (ECM). In the resulting phenotype, a rapid burst‐like stream of cervical cancer cells emerged from 3D aggregates embedded in soft collagen matrices (0.5 mg mL−1). This fluid‐like pushing mechanism, recorded within 8 h after embedding, shows high cell velocities and super‐diffusive motion. Because the swelling in this model system critically depends on integrin‐mediated cell–ECM adhesions and cellular contractility, the swelling is likely triggered by unsustained mechanotransduction, providing new evidence that pressure‐driven effects must be considered to more completely understand the mechanical forces involved in cell and tissue movement as well as invasion. [ABSTRACT FROM AUTHOR]

We evaluated and characterized the biodegradation of the herbicide diuron in its commercial form above its saturation concentration by Lysinibacillus fusiformis acclimatized by sequential batch culturing. Acclimatization was carried out in eight cycles in liquid culture, improving the capacity of L. fusiformis to remove diuron from 55.13 ± 1.3% in the first batch to 87.2 ± 0.11% in the eighth batch. Diuron biosorption was characterized with Langmuir and Freundlich isotherms, obtaining a maximum biosorption (q max) of 0.00885 mg mg−1. In diuron biodegradation assays, a consumption substrate biomass yield (Y SD/X) of 6.266 mg mg−1 was obtained, showing that biodegradation was the main mechanism in diuron removal. Diuron biodegradation by L. fusiformis was characterized by the Monod model, with a maximum specific growth rate (μ max) of 0.0245 h−1 and an affinity constant (K SD) of 344.09 mg L−1. A low accumulation of 3,4-dichloroaniline with the production of chloride ions indicated dechlorination when diuron was present at high concentrations. A phytotoxic assay conducted with Lactuca sativa showed that the toxicity of an effluent with diuron at 250 mg L−1 decreased when it was pretreated with acclimatized L. fusiformis. Acclimatization by sequential batch culturing improved the ability of L. fusiformis to biodegrade diuron at high concentrations, showing potential in the bioremediation of diuron-contaminated sites. [Display omitted] • L. fusiformis was acclimatized by sequential batch to high concentrations of diuron. • The diuron q max for L. fusiformis according to Langmuir isotherm was 8.85 mg g−1. • In the diuron biodegradation by L. fusiformis μ max value accord to Monod was 0.0245 h−1. • High diuron concentrations affect the granular structure in L. fusiformis. • Effluents with diuron treated by L. fusiformis decreased significative its phytotoxicity. [ABSTRACT FROM AUTHOR]

Tension and mechanical properties of muscle tissue are tightly related to proper skeletal muscle function, which makes experimental access to the biomechanics of muscle tissue formation a key requirement to advance our understanding of muscle function and development. Recently developed elastic in vitro culture chambers allow for raising 3D muscle tissue under controlled conditions and to measure global tissue force generation. However, these chambers are inherently incompatible with high-resolution microscopy limiting their usability to global force measurements, and preventing the exploitation of modern fluorescence based investigation methods for live and dynamic measurements. Here, we present a new chamber design pairing global force measurements, quantified from post-deflection, with local tension measurements obtained from elastic hydrogel beads embedded in muscle tissue. High-resolution 3D video microscopy of engineered muscle formation, enabled by the new chamber, shows an early mechanical tissue homeostasis that remains stable in spite of continued myotube maturation. [ABSTRACT FROM AUTHOR]

Abstract The brewers' spent grain is a by-product generated during brewery process and is a potential source for arabinoxylans (AX) extraction. In the present work, the extraction and characterization of an arabinoxylan-rich fraction from brewers' spent grain (BSG-AX) were performed, and BSG-AX was evaluated as release matrix for caffeine. The BSG-AX showed an AX content of 72% (w /w), a ferulic acid content of 3.52 μg/mg BSG-AX, an Ara/Xyl ratio of 0.89, an intrinsic viscosity of 41.18 mL g−1, and a molecular weight of 43.80 kDa. The studied BSG-AX showed a good antioxidant capacity compared with other polysaccharide gums and was estimated by DPPH (114.41 μM Trolox equivalent/g BSG-AX) and FRAP (49.01 μmol Fe2+/g BSG-AX) assays. The partial specific volume (0.63 cm3 g−1), loss on drying (10.68%), swelling (10.87%), solubility (80.93%) and electrostatic interactions (by zeta potential, −3.44 to −9.17 mV) were determined and used to evaluate the application of the BSG-AX as release matrix. A film containing the BSG-AX, glycerol (as plasticizer) and caffeine (target drug) was prepared as release matrix. Glycerol promoted an increase in the extensibility and the surface smoothness of the BSG-AX-caffeine film. The drug was released (≈98%) in about 7 h. These results are promising to concern the design and use of BSG-AX based biofilms for the controlled release of bioactive compounds. Graphical abstract Unlabelled Image Highlights • BSG-AX shows 72% of AX, and its Ara/Xyl ratio confers it a high solubility. • Ferulic acid contributes to the BSG-AX antioxidant capacity. • Loss on drying, swelling and solubility allow to evaluate the BSG-AX functions. • Glycerol contributes to obtain an extensible BSG-AX films with a smooth surface. • Caffeine release from BSG-AX film follows a non-fickian diffusion. [ABSTRACT FROM AUTHOR]

Species of the genus Prosopis were a major staple food in Aridoamerica before the arrival of Europeans. In the present work, chemical and nutritional properties of Prosopis laevigata pods were described. The composition in weight of pods of P. laevigata was 44% mesocarp, 35% endocarp, and 21% exocarp. Sugars, including sucrose, glucose, fructose, and xylose, were important components of pods, reaching a total sugars content of 447 g/kg in mesocarp flour. Considering the FAO-recommended amino-acid scoring patterns for humans older than 3 years, high values of Lys and sulfur-containing amino acids were found in flours. Thermal treatment of flours increases significantly the phenolic compounds content and free-radical scavenging capacity, an effect associated with the generation of Maillard reaction products. Flours of mesquite pods are a good source of phenolic compounds, with significantly higher free-radical scavenging capacity than soybean and common bean. [ABSTRACT FROM AUTHOR]

The behavior of foodborne bacteria on whole and cut mangoes and the antibacterial effect of Hibiscus sabdariffa calyx extracts and chemical sanitizers against foodborne bacteria on contaminated mangoes were investigated. Mangoes var. Ataulfo and Kent were used in the study. Mangoes were inoculated with Listeria monocytogenes, Shigella flexneri, Salmonella Typhimurium, Salmonella Typhi, Salmonella Montevideo, Escherichia coli strains (O157:H7, non-O157:H7 Shiga toxin–producing, enteropathogenic, enterotoxigenic, enteroinvasive, and enteroaggregative). The antibacterial effect of five roselle calyx extracts (water, ethanol, methanol, acetone, and ethyl acetate), sodium hypochlorite, colloidal silver, and acetic acid against foodborne bacteria were evaluated on contaminated mangoes. The dry extracts obtained with ethanol, methanol, acetone, and ethyl acetate were analyzed by nuclear magnetic resonance spectroscopy to determine solvent residues. Separately, contaminated whole mangoes were immersed in five hibiscus extracts and in sanitizers for 5 min. All foodborne bacteria attached to mangoes. After 20 days at 25 ± 2°C, all foodborne bacterial strains on whole Ataulfo mangoes had decreased by approximately 2.5 log, and on Kent mangoes by approximately 2 log; at 3 ± 2°C, they had decreased to approximately 1.9 and 1.5 log, respectively, on Ataulfo and Kent. All foodborne bacterial strains grew on cut mangoes at 25 ± 2°C; however, at 3 ± 2°C, bacterial growth was inhibited. Residual solvents were not detected in any of the dry extracts by nuclear magnetic resonance. Acetonic, ethanolic, and methanolic roselle calyx extracts caused a greater reduction in concentration (2 to 2.6 log CFU/g) of all foodborne bacteria on contaminated whole mangoes than the sodium hypochlorite, colloidal silver, and acetic acid. Dry roselle calyx extracts may be a potentially useful addition to disinfection procedures of mangoes. [ABSTRACT FROM AUTHOR]

Abstract: The potential of 13 foodborne bacteria to attach and survival on strawberries and the antimicrobial activities of Hibiscus sabdariffa calyx extracts and chemical sanitizers against foodborne bacteria on strawberries were investigated. Strawberries were inoculated with thirteen foodborne bacteria: Listeria monocytogenes, Shigella flexneri, Staphylococcus aureus, Salmonella Typhimurium, S. Typhi, S. Montevideo, Vibrio cholerae O1, and six pathotypes of Escherichia coli: O157:H7, Non‐O157:H7‐Shiga toxin‐producing, enteropathogenic, enterotoxigenic, enteroinvasive, and enteroaggregative. The antibacterial effects of four roselle calyx extracts (in water, methanol, acetone, and ethyl acetate), sodium hypochlorite, colloidal silver, and acetic acid against all pathogenic bacteria were evaluated on contaminated strawberries. All foodborne bacteria attached and survived on strawberries at least 15 days. Acetonic and methanolic roselle calyx extracts caused a greater reduction in the concentration (until 3.8‐log10 reduction in some cases) of all foodborne bacteria than the sodium hypochlorite, colloidal silver and acetic acid on contaminated strawberries. Practical applications: The strawberry is an important crop in United States, Spain, and Mexico. However, fresh strawberries have been associated with foodborne disease caused by E. coli O157:H7 and Salmonella. There is little information about the attachment and survival of foodborne bacteria on strawberries. A number of studies have shown that chemical agents used to eliminate pathogenic bacteria on fruits have a limited antimicrobial effect. Roselle calyx extracts are reported to have an antimicrobial effect. This study provides information about the attachment and survival of different foodborne bacteria on strawberries and information on the significant impact of dry roselle calyx extracts may be potentially useful in disinfection procedures of strawberries. [ABSTRACT FROM AUTHOR]

The objective of this work was to analyze an overvoltage case in a rural distribution feeder belonging to an electrical distribution company in the southeast of the Buenos Aires Province in Argentina. The network was modeled in the Electromagnetic Transients Program, based on the electrical parameters that make up the circuit, in order to evaluate its behavior under various switching and load states. The simulation analysis showed that during certain operation and load situations, the conditions for the overvoltage phenomenon occurred, causing a voltage increase in the single-phase transformer feeding. The guidelines for prevention and control of the phenomenon were provided taking into account the results obtained in the study. [ABSTRACT FROM AUTHOR]

In electric power systems, it is very common to find problems of power quality. The flow of harmonics significantly affect the operation of three-phase induction motors, and its energy characterization becomes difficult. There are different methods in situ to estimate motor efficiency. However, it is necessary to deepen the in situ efficiency analysis under nonsinusoidal voltage conditions. In this paper, a procedure is presented based on the equivalent circuits with losses segregation and using a bacterial foraging algorithm (BFA). It allows induction motors’ energy efficiency determination in field conditions with low invasiveness and working under harmonic distortion. The method was successfully tested on a 1.5 kW motor fed with significant levels of voltage harmonic. [ABSTRACT FROM AUTHOR]

Hydrolysis of corn leaf utilizing two treatment sequences was carried out in this study. The first treatment was chemical and involved subjecting the corn leaf to an alkaline pre-treatment and then to a smooth acid hydrolysis. The second consisted of biological delignification using the strain Trametes sp. 44 H88, followed by enzymatic hydrolysis using the enzymatic extract produced by Trichoderma sp. H88. The ligninolytic extract produced by Trametes sp. 44 H88 was used to detoxify the hydrolyzate. The results indicate that biological pre-treatment with delignification is more favorable and improves the subsequent hydrolysis, regardless of whether the hydrolysis is chemical or biological. The chemical treatment sequence obtained 80% conversion of monosaccharides, while the biological treatment sequence resulted in a 87% conversion rate. Finally, the use of the ligninolytic extract for the dephenolization of the hydrolyzate reduced the presence of compounds of phenolic origin by 23%. [ABSTRACT FROM AUTHOR]

Highlights: [•] Sporisorium reilianum produces an aspartyl protease extracellular Eap1 at acid pH. [•] The protease Eap1 was purified and was stable at a wide range of temperature and pH. [•] The enzyme degraded the albumin, the hemoglobin and plant proteins at acid pH. [•] The protease Eap1 had milk clotting activity. [•] The sequence of the protease corresponds to sr11394 gene of S. reilianum. [Copyright &y& Elsevier]

Straw is an agricultural byproduct that can be utilized to obtain bioethanol without affecting animal or human sustinence. This process involves recovering the sugars and reducing the lignin content present through the use of ligninolytic fungi such as the basidiomycete Trametes sp. 44. Fermentation was carried out using particle sizes 4 (4.76 mm, No. 4 sieve) and 8 (2.30 mm, No. 8 sieve), and two velocities of airflow (100 and 200 mL/min). Study results showed that particle size affected the production of hydrolytic enzymes, as particle size 8 favored the expression of cellulases and hemicellulases. In addition, both aeration and particle size affected the expression of ligninolytic enzymes, as it was observed that with particle size 8 and airflow of 200 mL/min, the study detected 63 AU/mL of LiP and 11 AU/mL of MnP. In the case of laccase, the enzymatic activity detected reached 220 AU/mL using particle size 8 and an airflow velocity of 200 mL/min. Statistical analysis indicated that the treatment that produced the highest biological delignification occurred when Trametes sp. 44 was grown on corn straw at particle size 4 and airflow of 100 mL/min, conditions that yielded 34% delignification at day 12 of fermentation. [ABSTRACT FROM AUTHOR]