Theoretical Maximum Value Research Articles

Biomarker evolution after neoadjuvant systemic therapy in breast cancer.

e12615 Background: Tumor heterogeneity is one of the hallmarks of breast cancer (BC) and has major implications for treatment response and resistance. Currently, there are no specific guidelines regarding biomarker reassessment on residual tumor post-neoadjuvant systemic therapy (NAST). In this study, we compared biomarker discordance between pre- and post-NAST tumors at our institution and determined if actionable changes were observed. We also report the impact of the detected biomarkers differences on the choice of adjuvant treatment. Methods: We conducted a retrospective review of BC patients who received NAST followed by definitive surgery from 2004 to 2020. The initial tissue biopsies were tested for estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) status per ASCO/CAP guidelines and repeated on the residual tumor tissue after NAST. Descriptive statistics was used to compare clinicopathologic characteristics. The biomarkers were compared using Wilcoxon’s t test and McNemar’s test. Concordance analysis of intrinsic subtypes was evaluated by Cohen’s kappa method. Results: Out of 434 patients who undergone surgical resection following NAST, 95 (22%) patients were identified to have repeat biomarker testing of residual invasive BC post NAST. 30 out of the 96 patients were found to discordant receptor status on repeat biomarker testing. In this cohort of thirty patients with discordant biomarkers, median age was 51.5 (29-70 years), 33.3% cases had stage II, and 56.7% had stage III BC. 66.75 patients were ER positive and/or PR positive, 20% patients were HER2 positive with one triple positive, and 13.3% patients were triple negative on pre-NAST tumors. Majority of the retesting was performed on breast tissue (90%, n = 27). The biomarker change was noted in 11 out of 30 (36.7%) for ER, 12 out of 30 (40%) for PR, and 13 out of 30 (43.3%) for HER2 marker. Concordance analysis demonstrated that HER2 was the most prone to change (Cohen K = -0.003) from pre-NAST to post-NAST specimen, whereas ER (Cohen k = 0.26) and PR (Cohen k = 0.18) were less subject to change. Kappa assumes theoretical maximum value of 1 when pre- and post-NAST are in agreement, a negative value indicates a poor concordance. One third of patients with discordant biomarkers had additional adjuvant treatment. 8 out of 30 patients (26.7%) were started on adjuvant anti-HER2 therapy due to HER2 positivity on post-NAST tumors. After ER positivity was detected on residual BC tumors, 2 initial triple negative patients (6.7%) were initiated on adjuvant endocrine therapy. Conclusions: Biomarker discordance due to tumor heterogeneity is an increasingly recognized phenomenon. Given the prognostic and therapeutic implications of biomarker driven BC management, retesting biomarkers routinely after NAST on residual invasive tumor would be beneficial in this patient population.

Radiation use efficiency increased over a century of maize (Zea mays L.) breeding in the US corn belt.

In the absence of stress, crop growth depends on the amount of light intercepted by the canopy and the conversion efficiency [radiation use efficiency (RUE)]. This study tested the hypothesis that long-term genetic gain for grain yield was partly due to improved RUE. The hypothesis was tested using 30 elite maize hybrids commercialized in the US corn belt between 1930 and 2017. Crops grown under irrigation showed that pre-flowering crop growth increased at a rate of 0.11 g m-2 year-1, while light interception remained constant. Therefore, RUE increased at a rate of 0.0049 g MJ-1 year-1, translating into an average of 3 g m-2 year-1 of grain yield over 100 years of maize breeding. Considering that the harvest index has not changed for crops grown at optimal density for the hybrid, the cumulative RUE increase over the history of commercial maize breeding in the USA can account for ~32% of the documented yield trend for maize grown in the central US corn belt. The remaining RUE gap between this study and theoretical maximum values suggests that a yield improvement of a similar magnitude could be achieved by further increasing RUE.

Proteome reallocation enables the selective de novo biosynthesis of non-linear, branched-chain acetate esters

The one-carbon recursive ketoacid elongation pathway is responsible for making various branched-chain amino acids, aldehydes, alcohols, ketoacids, and acetate esters in living cells. Controlling selective microbial biosynthesis of these target molecules at high efficiency is challenging due to enzyme promiscuity, regulation, and metabolic burden. In this study, we present a systematic modular design approach to control proteome reallocation for selective microbial biosynthesis of branched-chain acetate esters. Through pathway modularization, we partitioned the branched-chain ester pathways into four submodules including ketoisovalerate submodule for converting pyruvate to ketoisovalerate, ketoacid elongation submodule for producing longer carbon-chain ketoacids, ketoacid decarboxylase submodule for converting ketoacids to alcohols, and alcohol acyltransferase submodule for producing branched-chain acetate esters by condensing alcohols and acetyl-CoA. By systematic manipulation of pathway gene replication and transcription, enzyme specificity of the first committed steps of these submodules, and downstream competing pathways, we demonstrated selective microbial production of isoamyl acetate over isobutyl acetate. We found that the optimized isoamyl acetate pathway globally redistributed the amino acid fractions in the proteomes and required up to 23–31% proteome reallocation at the expense of other cellular resources, such as those required to generate precursor metabolites and energy for growth and amino acid biosynthesis. From glucose fed-batch fermentation, the engineered strains produced isoamyl acetate up to a titer of 8.8 g/L (>0.25 g/L toxicity limit), a yield of 0.22 g/g (61% of maximal theoretical value), and 86% selectivity, achieving the highest titers, yields and selectivity of isoamyl acetate reported to date.

A Method for Automated Pharmacophore Model Generation Using Multiple Copy Simultaneous Search

Pharmacophores are three‐dimensional arrangements of molecular features required for biological activity that are often used in virtual screening efforts to prioritize ligands for experimental screening. G protein‐coupled receptors (GPCR) are integral membrane proteins of considerable interest as targets for ligand discovery and drug development. Ligand‐based pharmacophore models can be constructed to identify structural commonalities between known bioactive ligands for targets including GPCR. However, structure‐based pharmacophores (which only require a resolved or predictive structure for a protein) have gained more attention as the number of publicly available, high‐resolution GPCR structures have increased (113 unique GPCR represented as of November 24, 2021). Thus, the goal of this study was to develop a method of structure‐based pharmacophore model generation applicable to ligand discovery for GPCR with few known ligands. Pharmacophore models have been generated using the active sites of 8 class A GPCR crystal structures via automated feature annotation of 5 randomly selected functional group fragments in an attempt to sample diverse combinations of pharmacophore features to aid in virtual screening efforts. Each of the 5000 generated pharmacophores was then used to search a database containing active and decoy/inactive compounds for 30 class A GPCR and scored using enrichment factor and goodness‐of‐hit metrics to assess performance. As proof‐of‐principle for this method, pharmacophore models were also generated within two dopamine receptor 2 (D2) crystal structures to elucidate novel ligands possessing activity for this receptor. Application of this method to the set of 8 class A GPCR generated pharmacophore models possessing the theoretical maximum enrichment factor value in both resolved structures (8 of 8 cases) and predictive models (7 of 8 cases), implying that generated pharmacophore models will prove useful in the context of virtual screening. Furthermore, application of this protocol to the D2 receptor resulted in the identification of novel candidate ligands whose activity has been confirmed with two in vitroactivity assays.

Study on the photothermal performance of polytetrafluoroethylene-based evaporation interface with solar-driven enhanced by graphite-clay

Interface evaporation by solar-driven was a thermal desalination method that offered high efficiency and energy-saving. The photo-thermal conversion efficiency of the interface evaporation device by solar-driven could be effectively improved by increasing the optical absorption capacity (a) and wetting capacity (MI) of the evaporation interface simultaneously. In this study, the photothermal performance of the solar-driven interface evaporation device was enhanced by graphite-clay. And an improved evaluation idea and a corresponding calculation method for photothermal performance were proposed. The morphology and hydrophilicity of the solar-driven polytetrafluoroethylene-based evaporation interface (GC-PTFE) enhanced by graphite-clay were characterized. A regression model of the contribution rate (ηfh) of graphite-clay on the photo-thermal conversion efficiency of the GC-PTFE unit was constructed. The results showed that the GC-PTFE (HB) presented a loose foam-like micron-level microporous structure, and all the GC-PTFEs offered hydrophilicity. The maximum theoretical value and corresponding prediction error of ηfh were 87.88% and 0.97%, respectively. The rejection rate of GC-PTFE for all measured ions was more than or equal to 99.95%. This study had an important guiding significance for optimizing the key structural parameters and evaluation system of photothermal performance of the GC-PTFE unit.

Assessing Chemical Migration from Plastic Food Packaging into Food Simulant by Gas and Liquid Chromatography with High-Resolution Mass Spectrometry.

Some components of plastic food packaging can migrate into food, and whereas migration studies of known components are required and relatively straightforward, identification of nonintentionally added substances (NIAS; unknowns) is challenging yet imperative to better characterizing food safety. To this aim, migration was investigated across 24 unique plastic food packaging products including plastic wrap, storage bags, vacuum bags, and meat trays. Gas and liquid chromatography separation systems coupled with Orbitrap mass analyzers were used for comprehensive nontargeted screening of migrants. Tentative identifications of features were assigned by searching commercial databases (e.g., NIST, MZCloud, ChemSpider, Extractables and Leachables) and filtering results based on mass accuracy, retention time indices, and mass spectral patterns. Several migrants showed elevated levels in specific food packaging types, particularly meat trays and plastic wrap, and varying degrees of migration over the 10 days. Eleven putative migrants are listed as substances of potential concern or priority hazardous substances. Additionally, migration amounts of an Irgafos 168 degradation product determined by semiquantitation exceeded proposed theoretical maximum migration values.

Food abundance mediates the harmful effects of ZnO nanoparticles on development and early reproductive performance of Daphnia magna

Most aquatic ecosystems are at risk of being polluted by new environmental pollutant nanoparticles. As the main food source of zooplankton, the biomass of algae always fluctuates. Cladocerans, an important part of zooplankton, are usually be simultaneously exposed to different abundance of algae and nanoparticles in aquatic environment. To evaluate the combined effects of food abundance and ZnO nanoparticles concentration on the development and early reproductive performance of cladocerans, we exposed Daphnia magna, a common and representative model organism in cladocerans, to the combinations of different abundances of Chlorella pyrenoidosa and different concentrations of ZnO nanoparticles, recorded the key life-history traits, and used multiple models to fit the data. Results showed that high level of ZnO nanoparticles and low abundance Chlorella had an interactively negative effect on the life history of D. magna. When D. magna was exposed to ZnO nanoparticles, some life history traits, such as survival time, body length at maturation, and offspring per female, increased exponentially with the increase of food abundance, and then reached a theoretical maximum value, whereas some other life history traits, such as time to maturation and time to first brood, showed an opposite trend. However, higher Chlorella abundance reduced the negative effect of ZnO nanoparticles on D. magna, but the negative effect could not be eliminated with the increase of food abundance. Below Chlorella 0.30 mg C L−1, food plays a decisive role, while at or above this threshold, ZnO nanoparticles play a decisive role. Therefore, the effect of different ZnO nanoparticles concentrations can be fully reflected only when food is sufficient, and the negative effects of food shortages may mask the toxic effects of ZnO nanoparticles on D. magna. The findings indicated that the effects of food abundance should be considered in evaluating the realistic impact of pollutants on zooplankton.

Optimization Analysis to Evaluate the Relationships between Different Ion Concentrations and Prymnesium parvum Growth Rate

The purpose of this study was to evaluate the optimum environmental condition required for reaching the maximum growth rate of P. parvum. Eight ions (Na+, K+, CO32−, HCO3−, Ca2+, Mg2+, Cl−, and SO42−) were divided into two groups with a uniform design of 4 factors and 10 levels. The results showed a rising trend in growth rate with increasing ion concentrations. However, concentrations that exceeded the threshold led to a slowdown in the growth rate. Therefore, adequate supply of ion concentrations promoted growth of P. parvum, whereas excessively abundant or deficient ion concentrations inhibited its growth rate. Specifically, the order of impact of the first four ion factors on the growth rate was Na+ > HCO3− > K+ > CO32−. The growth rate of P. parvum reached the maximum theoretical 0.999 when the concentrations of Na+, K+, CO32−, and HCO3− ions were 397.98, 11.60, 3.37, and 33.31 mg/L, respectively. This theoretical growth maximum was inferred from the experimental results obtained in this study. For other ion factors, SO42− had the most influence on the growth rate of P. parvum, followed by Mg2+, Ca2+, and Cl− ions. The growth rate of P. parvum reached the maximum theoretical value of 0.945 when the concentrations of Ca2+, Mg2+, Cl−, and SO42− ions were 11.52, 32.95, 326.29, and 377.31 mg/L, respectively. The findings presented in this study add to our understanding of the growth conditions of P. parvum and provide a theoretical basis for dealing with the water bloom it produces in order to control and utilize it.

New insights into diffusion and reaction of CO2 gas in recycled aggregate concrete

The diffusion and reaction mechanisms of gas in natural aggregate concrete cannot be directly used for modelling the gas behavior in recycled aggregate concrete due to its inhomogeneity. Thus, the inhomogeneity of CO2 diffusivity in RAC is simulated for the first time using the multi-path modelling theory proposed herein. The diffusion and reaction models of CO2 in each path are then established. The carbonation depth in each path is determined. The reliability of theoretical maximum and average values of carbonation depths in different paths is further verified by experimental data. The results showed that there were five kinds of CO2 diffusion paths in recycled aggregate concrete and their carbonation depths showed a noteworthy difference. Besides, the developed theoretical model can predict the maximum value, weighted and mathematic average values of carbonation depths with reasonable accuracy, and the model in this study was more accurate than those in the literature.

Balancing the health effect between risks of methylmercury and benefits of nutrients in consumption of Chinese mitten crab (Eriocheir sinensis) in China.

Aquatic products contain both beneficial substances such as polyunsaturated fatty acids and harmful compounds such as methylmercury, and their combined health effects should be assessed at a common end point for a rational analysis. We used a risk-benefit model to assess net IQ point gain from consumption of Chinese mitten crabs (Eriocheir sinensis) from Jiangsu Province. Levels of methylmercury in the edible parts of the crabs ranged from 0.79 to 69.47μg/kg (mean: 26.88 ± 15.09μg/kg). Levels of methylmercury did not differ by sampling location. In aquaculture experiments, we simulated artificial pond farming using either iced trash fish or formulated feed. Crabs fed iced trash fish contained 28.72 ± 2.30mg/g of eicosapentaenoic acid and docosahexaenoic acid and crabs fed formulated feed contained 19.64 ± 3.62mg/g of eicosapentaenoic acid and docosahexaenoic acid. Model calculations estimated a gain of 7.52 IQ points from consumption of crabs fed formulated feed and 11.00 IQ points from consumption of crabs fed iced trash fish. They are all above the maximum theoretical IQ point gain value. Chinese mitten crab is a kind of high-quality food which is beneficial to the neural development of infants. Our findings may assist in improving crab farming methods and consumption patterns, accelerating the sustainable development of the Chinese mitten crab industry.

Heat-Induced Dry Hydrolysis of Sodium Borohydride/Oxalic Acid Dihydrate Composite for Hydrogen Production.

The generation of hydrogen, free of poisonous gas, combined with a lightweight proton-exchange membrane fuel cell can expand the use of hydrogen energy from conventional ground transportation vehicles and power stations to a variety of flying vehicles and wearable devices for civilian and military purposes. Herein, a hydrogen fuel composite composed of sodium borohydride (SB) and oxalic acid dihydrate (OA·2H2O) is introduced. The SB/OA·2H2O composite was easily decomposed to generate pure hydrogen at a trigger temperature of 50 °C, at which the water molecules of the OA·2H2O component were effectively liberated, inducing hydrolysis of the SB component to produce hydrogen gas. This dry hydrolysis-based hydrogen generation using the SB/OA·2H2O composite has the merits of rapidly generating hydrogen (i.e., 0.4 g of the composite can be fully decomposed within a minute at low temperatures), free of poisonous gas, in approximately 5 wt % yield (the theoretical maximum value).

Mechanism of Dyspnea during Exercise in Children with Corrected Congenital Heart Disease.

This study will evaluate cardiorespiratory and peripheral muscle function and their relationship with subjective dyspnea threshold after the surgical correction of congenital heart disease in children. Thirteen children with surgically repaired congenital heart disease were recruited. Each participant performed an incremental exercise test on a cycle ergometer until exhaustion. Gas exchanges were continuously sampled to measure the maximal aerobic parameters and ventilatory thresholds. The functional capacity of the subjects was assessed with a 6 min walk test. At the end of the exercise test, isokinetic Cybex Norm was used to evaluate the strength and endurance of the knee extensor muscle in the leg. Dyspnea was subjectively scored with a visual analog scale during the last 15 s of each exercise step. Oxygen consumption measured at the dyspnea score/VO2 relationship located at the dyspnea threshold, at which dyspnea suddenly increased. Results: The maximal and submaximal values of the parameters describing the exercise and the peripheral muscular performances were: VO2 Peak: 33.8 ± 8.9 mL·min−1·kg−1; HR: 174 ± 9 b·min−1; VEmax: 65.68 ± 15.9 L·min−1; P max: 117 ± 27 W; maximal voluntary isometric force MVIF: 120.8 ± 41.9 N/m; and time to exhaustion Tlim: 53 ± 21 s. Oxygen consumption measured at the dyspnea threshold was related to VO2 Peak (R2 = 0.74; p < 0.01), Tlim (R2 = 0.78; p < 0.01), and the distance achieved during the 6MWT (R2 = 0.57; p < 0.05). Compared to the theoretical maximal values for the power output, VO2, and HR, the surgical correction did not repair the exercise performance. After the surgical correction of congenital heart disease, exercise performance was impeded by alterations of the cardiorespiratory function and peripheral local factors. A subjective evaluation of the dyspnea threshold is a reliable criterion that allows the prediction of exercise capacity in subjects suffering from congenital heart disease.

Direct upcycling of polyethylene terephthalate (PET) waste bottles into α-Fe2O3 incorporated MIL-53(Al) for the synthesis of Al2O3/Fe3O4-encapsulated magnetic carbon composite and efficient removal of non-steroidal anti-inflammatory drugs

The upcycling of polyethylene terephthalate (PET) waste into high-value-added materials can have a significant contribution to global environmental protection. In this study, considering the unique thermal behaviors of PET and metal salts (i.e., Al and Fe) under similar hydrothermal conditions, we proposed a novel solvent-free one-pot approach for the upcycling of PET. In a one-pot hydrothermal reaction at 220 ℃ under self-generated pressure, PET waste was depolymerized into starting monomers (terephthalic acid and ethylene glycol), Al-based metal–organic frameworks (MIL-53(Al)) were fabricated, and iron oxides (α-Fe2O3) were formed simultaneously. X-ray diffraction measurements clearly demonstrated that α-Fe2O3 incorporated MIL-53(Al) (α-Fe2O3/MIL-53(Al)) was successfully synthesized directly from PET waste bottles via a novel green approach. After the annealing process, the α-Fe2O3/MIL-53(Al) precursor was successfully converted to an Al2O3/Fe3O4-encapsulated magnetic carbon composite (Al/[email protected]). The feasibility test proved that the Al/[email protected] prepared at an annealing temperature of 600 ℃ (Al/[email protected]600) effectively removed four common non-steroidal anti-inflammatory drugs, i.e., ibuprofen (96.31%), diclofenac (66.84%), naproxen (87.83%), and ketoprofen (90.07%). Owing to its low removal rate, diclofenac was selected as the target pollutant, and the adsorption parameters were optimized using response surface methodology. Under the optimized conditions (solution pH = 5.0, adsorbent dosage = 1.21 g/L, and contact time = 15 h), the maximum actual diclofenac removal (92.94%) was obtained, which agreed with the maximum theoretical value (93.15%). In addition, Al/[email protected]600 exhibited excellent reusability (removal rate > 85%) after five repetitive adsorption-regeneration cycles. This study demonstrates the promising opportunities for the upcycling PET waste bottles as efficient adsorbents for the removal of emerging environmental contaminants.

The effect of nitrogen species on the catalytic properties of N-doped graphene

The production of effective catalysts in the oxygen reduction reaction (ORR) continues to be a great challenge for scientists. A constant increase in demand for energy storage materials is followed by a proportionate increase in the number of reports on electrocatalyst synthesis. The scientific world focuses on environmentally friendly materials synthesized in accordance with the safest possible. In this work, we developed a facile method of obtaining heavy-metal-free electrode materials that are effective in ORR. Graphene-based catalysts were doped using azodicarbonamide (ADC) as the source of nitrogen, then carbonized at high temperatures in the range of 700–900 °C under inert gas flow. The produced materials were tested as catalysts for ORR, which is the most important reaction for Zn–air batteries and fuel cells. All obtained nitrogen-doped graphene foams showed increased catalytic activity in ORR owing to active sites created by nitrogen functional groups on the graphene surface. This paper shows that carbonization temperature has a significant impact on nitrogen content and that a small percentage of nitrogen may have a positive effect on the catalytic activity of the obtained materials. The number of transferred electrons in ORR was found to range from three to the maximal theoretical value, i.e., four.

Nonlinear Predictive Control Method for Maximizing Wind Energy Extraction of Variable Speed Wind Turbines under Turbulence

Generally, wind turbines are controlled by Maximum Power Point Tracking (MPPT) strategies in order to achieve maximum power extraction below its rated value. But it is very difficult to adjust the rotor speed according to the highly fluctuating wind speed accurately and quickly, due to the large inertia of wind turbines, and therefore, the efficiency of wind energy extraction will never reach its theoretical maximum value. To address this problem, a new method has been developed in this paper which is totally different from the known classical methods. In this paper a wind speeds prediction for maximum wind energy extraction (MWEE) of variable-speed wind turbines (VSWTs) is presented. A nonlinear predictive control is developed by solving a nonlinear optimization problem to generate the optimal generator torque sequence and consequently the previewed rotor speeds with maximum wind energy extraction. A detailed explanation has been provided of how this new method works through a detailed block diagram; accurate algorithm and flowchart. The proposed nonlinear predictive method takes full advantage and the MWEE objective is confirmed by the simulation results compared to the classical TSR methods.

Thermodynamic Consistency of the Cushman Method of Computing the Configurational Entropy of a Landscape Lattice.

There has been a recent surge of interest in theory and methods for calculating the entropy of landscape patterns, but relatively little is known about the thermodynamic consistency of these approaches. I posit that for any of these methods to be fully thermodynamically consistent, they must meet three conditions. First, the computed entropies must lie along the theoretical distribution of entropies as a function of total edge length, which Cushman showed was a parabolic function following from the fact that there is a normal distribution of permuted edge lengths, the entropy is the logarithm of the number of microstates in a macrostate, and the logarithm of a normal distribution is a parabolic function. Second, the entropy must increase over time through the period of the random mixing simulation, following the expectation that entropy increases in a closed system. Third, at full mixing, the entropy will fluctuate randomly around the maximum theoretical value, associated with a perfectly random arrangement of the lattice. I evaluated these criteria in a test condition involving a binary, two-class landscape using the Cushman method of directly applying the Boltzmann relation (s = klogW) to permuted landscape configurations and measuring the distribution of total edge length. The results show that the Cushman method directly applying the classical Boltzmann relation is fully consistent with these criteria and therefore fully thermodynamically consistent. I suggest that this method, which is a direct application of the classical and iconic formulation of Boltzmann, has advantages given its direct interpretability, theoretical elegance, and thermodynamic consistency.

Population Pharmacokinetic Modeling and Dose Optimization of Vancomycin in Chinese Patients with Augmented Renal Clearance.

Patients with augmented renal clearance (ARC) have been described as having low vancomycin concentration. However, the pharmacokinetic model that best describes vancomycin in patients with ARC has not been clarified. The purpose of this study is to determine the pharmacokinetic of vancomycin in Chinese adults and the recommend dosage for patients with different renal function, including patients with ARC. We retrospectively collected 424 vancomycin serum concentrations from 209 Chinese patients and performed a population pharmacokinetic model using NONMEM 7.4.4. The final model indicated that the clearance rate of vancomycin increased together with the creatinine clearance, and exhibited a nearly saturated curve at higher creatinine clearance. The estimated clearance of vancomycin was between 3.46 and 5.58 L/h in patients with ARC, with 5.58 being the maximum theoretical value. The central volume of distribution increased by more than three times in patients admitted to Intensive Care Unit. Monte Carlo simulations were conducted to explore the probability of reaching the target therapeutic range (24-h area under the curve: 400–650 mg·h/L, trough concentration: 10–20 mg/L) when various dose regimens were administered. The simulations indicated that dose should increase together with the creatinine clearance until 180 mL/min. These findings may contribute to improving the efficacy and safety of vancomycin in patients with ARC.

Influence of gradation of aggregates using particle packing methods on strength and microstructure of blended cement mortars

Blended cements having partial replacement of fly ash (FA) and granulated blast furnace slag (GBFS) with Ordinary Portland Cement (OPC) have proven to be more sustainable cements with several ecological benefits, increased performance and durability aspects compared to plain OPC. In this study, three blended cements, namely Portland Pozzolana Cement (OPC + FA), Portland Slag Cement (OPC + GBFS) and Composite Cement (OPC + FA + GBFS) are examined. Three Particle Packing Models (PPM) viz. Modified Toufar Model (MTM), J D Dewar model (JDD) and Compressible Packing Model (CPM) are considered to evaluate the gradation of fine aggregates used in designing the mortars and are compared with the mortars designed as per IS 650:2008. The theoretical maximum packing density values obtained based on MTM, JDD and CPM models are 0.681, 0.674 and 0.668 respectively, while the experimental packing density values are 0.617, 0.626 and 0.642 respectively. The compressive strength of Composite Cement (CC), Portland Slag Cement (PSC) and Portland Pozzolana Cement (PPC) mortars exhibited a delay in gain of strength compared to OPC mortars. The mortar samples prepared using CPM model, showed an average increase in compressive strength of 20.71% at 7 days, 12.26% at 28 days and 10.29% at 90 days compared to samples designed using IS 650:2008. Similar trend was observed from MTM and JDD mortar samples also with strength of mortars varying as CPM > MTM > JDD > IS 650. This shows that particle packing models are useful in overcoming the delay in early strength of blended cements due to slow pozzolanic reaction. The hydrated phases of cement and microstructure is examined using Scanning Electron Microscopy and X-Ray Diffraction.

Increased sediment deposition triggered by climate change impacts freshwater pearl mussel habitats and metapopulations

Abstract The freshwater pearl mussel Margaritifera margaritifera is a benthic organism sensitive to hydrological regime alterations and habitat degradation driven by excessive fine bed material deposit (FBMD). Both issues are potentially exacerbated by climate change. Understanding how climate change affects future mussel habitats and the dispersal among them (dependent on the brown trout as fish host) can support the planning of effective conservation actions. To project the impacts of climate change on the mussel, a semi‐mechanistic modelling cascade was implemented for the Aist catchment in Austria (630 km2), including a hydrological model, a hydraulic model, Random Forest Models for FBMD accumulation risk and Species Distribution Models. Two climate change models (RCPs 4.5 and 8.5) for two future horizons (2060 and 2090) were considered. A graph‐based assessment of the structural connectivity was used to measure the probability of successful dispersal. Results show a reduction of peak discharge that cascades into a widespread reduction in shear stresses during high flow. The mussel's habitats, defined by hydraulics (i.e. patches with low shear stresses during high flow), are predicted to be stable over the simulated scenarios. The pressure of FBMDs over the delineated habitat patches is predicted to increase in the future due to the reduced stream transport capacity, reducing up to 25% of the available patches in 2090 for RCP 8.5. Consequently, the mussel's dispersal probability decreases to 44.3%–75.6% of the maximum theoretical value, with the highest drops for short dispersal distances, impacting metapopulation dynamics. Synthesis and applications. The widespread issue of fine sediment deposition in the streambed will be exacerbated for those catchments where climate change reduces the stream transport capacity. The impacts on the freshwater pearl mussel include habitat loss due to the formation of a new unsuitable substrate, and a decrease in the potential dispersal among the residual habitats. Thus, conservation plans that aim to protect the mussel in the future should focus on the mitigation of fine bed material deposits, prioritizing those subreaches that offer the highest potential for preserving connectivity among suitable habitats.

Approach to Evaluating Seismic Intensity by Integrating InSAR Co-seismic Deformation and Far Field Observation Data

Seismic intensity (SI) is an important reference index for understanding disaster situations, establishing emergency rescue plans and performing loss assessments after an earthquake. In this paper, we investigated the feasibility of assessing SI through interferometric synthetic aperture radar (InSAR) data after the Wenchuan earthquake on May 12, 2008, in China. The proposed approach relies on pre-existing residential data to obtain the regional seismic deformation corresponding to blocks. Theoretical maximum and minimum values analysis was carried out according to seismic attenuation relationships, and the deformation points were classified using Jenks natural breakpoints. The deformation field data were used to evaluate the epicenter and periphery areas. Instrument-based intensity values of stations were included in our analysis and used to investigate the periphery of the study area. Classification results of deformation field and instrument-based intensity values were combined to form a complete deformation field. The effectiveness of the method was verified based on a case study of the Yushu earthquake, another severe earthquake in China.The work represents one of the first attempts to establish the potential relationship between the seismic deformation field and intensity in China, validated against ground survey data. This study addresses methodological aspects, highlighting the potential of the co-seismic deformation field for intensity assessment, and discusses the limitations of terrain and data in this approach compared to ground surveys.