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Abstract This present study investigates the heat-assisted extraction (HAE) of bioactive antioxidants from Enantia chlorantha stem bark (ECSB). The effects of process parameters of operating temperature (OT: 35–55 °C), extraction time (ET: 100–200 min) and solid: liquid ratio (S/L: 1:20–1:50 g/mL) are determined on the total polyphenol content (TPC), antioxidant activity (AA) and extract yield (EY) using the D-Optimal design. Multi-criteria optimization is also conducted to determine the HAE optimum conditions. The integrated process for E. chlorantha stem bark extracts (ECBEs) production is thereafter designed with the optimum HAE conditions and techno-economically analysed. Three industrial ECBEs production setups (5, 100 and 1000 L extractor capacities) are analysed for probable scale-up and the risk & sensitivity analyses are conducted via Monte Carlo simulation. The HAE parameters affect the extraction process significantly. The OT, ET and S/L that maximize the TPC, AA and EY simultaneously are: OT = 54.10 °C, ET = 120.16 min and S/L = 1:50 g/mL. The 1000 L plant extractor setup is the most economical capacity having the least unit production cost (UPC) of 763.52 US$/kg ECBEs. The certainty of achieving 763.52 US$/kg ECBEs for the 1000 L capacity is 55.43% and the only variable with negative contribution (− 37.9%) on ECBEs UPC is the extract recovery variable.

Evidence suggests that short-term study abroad experiences can help advance various dimensions of second language (L2) learners' linguistic competence. However, the extent to which gains following a brief sojourn are durable and maintained after immersion remains an open question. The present study examined both the immediate and sustained learning outcomes following a short-term study abroad program by considering L2 Spanish learners' (a) linguistic gains in global proficiency, oral production, and L2 knowledge, and (b) nonlinguistic gains in perceived psychobehavioral flexibility, a trait that remains under-researched despite its broad relevance to study abroad contexts. Data were collected at the onset and end of a summer study abroad program in Spain, as well as 5 weeks post-sojourn, after students' reimmersion in the first language environment. Mixed-effects models revealed that gains in global proficiency and some aspects of oral production and L2 knowledge, as well as increases in perceived psychobehavioral flexibility, were noticeable at the end of the program and were maintained for several weeks post-sojourn in the absence of further L2 instruction. Findings provide a first look into the potential of short-term study abroad for promoting durable developmental changes across linguistic and nonlinguistic domains.

The majority of US university students studying foreign languages are enrolled in introductory courses that are typically part of a coordinated curriculum. Such courses conventionally include the assessment of second language (L2) writing skills. However, given that these assessments can be broadly conceived and vary by program, their design and implementation are subject to differing opinions and beliefs from the stakeholders involved. In an effort to better understand how their views of L2 writing assessments overlap and/or diverge, the present study examined instructor (N = 28) and student (N = 183) beliefs in Spanish language programs at three public US universities using an online Likert-scale and ranked-choice questionnaire. Results revealed that although there was misalignment regarding the pedagogical purpose of such assignments, in general there was broad agreement among the two groups, including the use of a writing-to-learn approach to develop both specific and broad linguistic skills.

This work reported the effects of heat-assisted extraction (HAE) temperature (35–55 °C), solid: liquid (1:20–1:50 g/mL) and time (100–200 min) on the total phenolic content (TPC, GAE/g), bioactive extracts yield (EYs, %) and antioxidant activity (AA, AAE/g) of Senna alata leaves (SALs) using the Box-Behnken experimental design. Multi-objective HAE process optimization was also carried out. The large scale (1000 L extractor capacity) HAE integrated process was thereafter designed using the global optimum data and techno-economically analyzed. Profitability sensitivity and uncertainty analyzes were conducted on the large scale integrated process to determine the associated risk. The extraction temperature, solid: liquid and time had significant effects on TPC, EYs and AA. The extraction conditions at 54.97 °C, 41.59 g/mL and 100 min gave an optimum TPC, EYs and AA of 84.3897 mg GAE/g, 21.3607% and 6.61696 µM AAE/g, respectively. The phenolic profiling showed that SALs extracts were rich in betulinic, gallic, chlorogenic, caffeic and ferulic acids. The large scale integrated plant possessed net present value (NPV), internal rate of return (IIR), return on investment (ROI) and payback time (PBT) of 193.511 US$, 7.11%, 13.97%, and 7.16 y, respectively. The certainty of obtaining base case NPV and ROI were 55.88 and 60.96%. Out of technical and cost variables selected for sensitivity analysis, extracts recovery contributed the most (26.6 and 27.9% in NPV and ROI, respectively) while the extraction temperature and SALs purchase cost did not contribute significantly to the variance in NPV and ROI.

The first goal of this study was to examine how individual differences in initial L2 proficiency help explain L2 grammar development in oral production during short-term immersion abroad. The second goal of the study was methodological, and evaluated challenges that can result from operationalizing learners' initial L2 proficiency as pretest performance on outcome measures (as opposed to independent proficiency measures) in analyses of L2 change. L2 Spanish learners participating in summer study abroad completed an elicited imitation task and two oral production tasks. Production data were analyzed for changes in relevant grammatical complexity and accuracy dimensions. Results indicate that learners with higher initial L2 proficiency experience greater L2 grammar advancement from short-term immersion, and that pretest performance can be an unreliable operational estimate of initial proficiency when analyzing L2 gains. We discuss findings following cognitive accounts of SLA, and highlight methodological implications for further research in immersion contexts and beyond.

This work presents an integrated heat-assisted extraction process for the production of crude anthocyanins powder (CAnysP) from Hibiscus sabdariffa calyx using SuperPro Designer. The influence of process scale-up (0.04 -1000L) and variables (temperature, time and ethanol proportion in solvent) were investigated by adopting a circumscribed central composite design on techno-economic parameters such as annual production rate (APR) and unit production cost (UPC) CAnysP. The individual runs in the CCCD were taken as different process scenario and simulated independently. Multi-gene genetic programming (MGGP) was further used to develop robust predictive models. The robustness of the model and sensitivity analysis were ascertained using the Monte Carlo simulation. The process scenario at 30 min, 30 °C, 50% and 1000 L possessed the highest CAnysP APR and lowest UPC. MGGP- models predicted R2 = 0.9984 for CAnysP APR and R2 = 0.9643 for UPC and certainty (99.98% for CAnysP APR and 98.47% for UPC).

The present study evaluated the extraction of flavonoids, phenolics and antioxidants from the Khaya senegalensis plant. A Box-Behnken design implementing response surface methodology was employed to optimize the process. The process variables include time, temperature and concentration, while total phenolic content, flavonoid content, antioxidant activity and yield are the responses. The optimum yield of 15.2467 %, total phenolic content of 0.8939 mg·g-1, total flavonoid content of 12.1453 mg·g-1 and antioxidant activity of 0.991182 mg·g-1 were obtained at a temperature of 42.59 °C, time of 3.58 hours and solvent concentration of 0.02 g·mL-1. The ANOVA and parametric analysis demonstrate that the process variables significantly affect the yield, total flavonoid content, and antioxidant activity.

The role of attention has been central to theoretical and empirical inquiries in second language (L2) acquisition. The current eye-tracking study examined how external and internal attentional manipulations (Chun, Golomb, &Turk-Browne, 2011) promote L2 grammatical development. Participants (n = 55) were exposed to Spanish direct-object pronouns under external or internal attentional manipulations, which were implemented through textual input enhancement or structured input practice, respectively. Results for both manipulations indicated that (a) learner attentional allocation to the form was affected; (b) L2 gains were evidenced, although only the internal manipulation led to above-chance performance; and (c) L2 gains were related to attention allocated to the form under the external manipulation and to a lesser extent the internal manipulation. Overall, findings may inform theoretical perspectives on attention and elucidate cognitive processes related to L2 instruction.

This work investigated the influence of process variables of extraction temperature (35–55 °C), solid to liquid ratio (1:20–1:50 g/mL) and time (100–200 min) on the total phenolic content (TPC) and yield (EY) of Carica papaya leaves (CPL) extracts using Box-Behnken experimental design available in Design Expert software. Bi-objective process optimization was also carried out using the desirability function algorithm. The optimum process variables were later used to design an integrated process for the production of CPL extracts with the assistance of SuperPro Designer software. Scale-up studies and economic analysis for CPL extracts production were investigated in the range of 0.638–20.431 × 103 kg CPL extracts/y to determine the most economically feasible production capacity based on the minimum unit production cost (UPC) of CPL extracts. The risk and sensitivity analyses of the most economically feasible production scale were carried out using the Monte Carlo simulation in Oracle Crystal Ball software. Process variables had notable influences on the TPC and EY of CPL extracts. The extraction temperature of 35 °C, solid to liquid ratio of 40.25 g/mL and time of 100 min gave the optimum TPC of 74.65 mg GAE/g d.b and EY of 18.76 % (w/w). HPLC results indicated that CPL extracts were rich in gallic, betulinic, chlorogenic, ellagic, ferulic and caffeic acids. The designed integrated process showed similar behavior with the laboratory scale of 0.18758 g CPL extracts/batch. The preliminary techno-economic analysis indicated that plant capacity has a strong dependence on the material & energy demands and process economics. Plant capacity of 19.857 × 103 kg CPL extracts/y possessed the least UPC and was selected as the most economically feasible scale. The certainty of obtaining base case UPC value of 525.21 US$/kg CPL extracts was 75.20%. Sensitivity analysis showed that extracts recovery, CPL/water, centrifuge purchase cost, extraction time, extractor purchase cost and extraction temperature contributed -5.3 %, +42.8%, +4.0%, +47.1%, +0.1%, and +0.5%, respectively to the variance in UPC of CPL extracts.

The wastewater from paint manufacturing industry contains high quantity of pollutants that are generated from washing equipment, as well as chemical additives. Hence, coagulation–flocculation was applied in the present study to evaluate the performance of some natural coagulant derived from Hibiscus esculentus L,(okra) Detarium microcarpum,(sweet dater) Xanthosoma (cocoyam) and Crassostrea Virginica, (oyster shell) in the removal of turbidity from paint wastewater (PW). The coagulants were characterized using Fourier transform infrared spectrometer (FTIR), Scanning electron microscopy (SEM) and X-ray diffraction (XRD). A laboratory jar test was employed for the experiments. Process kinetic was studied to determine coagulation-flocculation parameters such as coagulation rate constant and coagulation half-life τ1/2. The effects of the operating parameters such as initial pH of the wastewater, coagulant dosage and settling time affecting the efficiency of turbidity removal were studied in a one-factor-at-a-time (OFAT) process. Box-Behnken Design (BBD) was used in designing the experiment; evaluate the individual and interactive effect of the variables and determining the optimum conditions. Statistical parameters such as coefficient of determination R2, sum of square roots due to error (SSE) and the root mean square error (RMSE) were used to evaluate the adequacy of the process. The optimum removal of turbidity was observed at pH range 2–4, dosage 100–200 mg/L and settling time of 30 min for the coagulants, with removal efficiency of 60–92.6% a second order polynomial regression equation with R2 values of 0.9644, 0.9827, 0.9707 and 0.9718 for OSC, DMC, CYC and ODC, respectively. While the coagulation half-time, τ1/2 ranges from 0.98 for OSC, 0.87 for DMC, 13.73 for CYC and 9.15 for ODC. The study has proved the coagulant can be used in treatment of turbidity from paint wastewater.

We conducted a multisite replication study with aspects of preregistration in order to explore the feasibility of such an approach in second language (L2) research. To this end, we addressed open questions in a line of research that has examined whether having learners attend to form while reading or listening to a L2 passage interferes with comprehension. Our results are consistent with findings from the specific paradigm that we replicated in that no effects on comprehension were detected in analyses conducted over all sites. However, further investigation is warranted due to site-specific effects and methodological limitations. We found all aspects of the multisite registered replication approach to be useful although the registration component itself appeared to be an especially feasible and valuable first step toward increasing the robustness and generalizability of findings in our field.

Since December 2019, the coronavirus 2019 (COVID-19) pandemic has rapidly spread and overwhelmed healthcare systems worldwide, urging physicians to understand how to manage this novel infection. Early in the pandemic, more severe forms of COVID-19 have been observed in patients with cardiovascular comorbidities, who are often treated with renin-angiotensin aldosterone system (RAAS)-blockers, such as angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs), but whether these are indeed independent risk factors is unknown. The cellular receptor for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the membrane-bound angiotensin converting enzyme 2 (ACE2), as for SARS-CoV(-1). Experimental data suggest that expression of ACE2 may be increased by RAAS-blockers, raising concerns that these drugs may facilitate viral cell entry. On the other hand, ACE2 is a key counter-regulator of the RAAS, by degrading angiotensin II into angiotensin (1-7), and may thereby mediate beneficial effects in COVID-19. These considerations have raised concerns about the management of these drugs, and early comments shed vivid controversy among physicians. This review will describe the homeostatic balance between ACE-angiotensin II and ACE2-angiotensin (1-7) and summarize the pathophysiological rationale underlying the debated role of the RAAS and its modulators in the context of the pandemic. In addition, we will review available evidence investigating the impact of RAAS blockers on the course and prognosis of COVID-19 and discuss why retrospective observational studies should be interpreted with caution. These considerations highlight the importance of solid evidence-based data in order to guide physicians in the management of RAAS-interfering drugs in the general population as well as in patients with more or less severe forms of SARS-CoV-2 infection.