ABSTRACT
We present a multiscale stochastic analysis of foreign exchange rates using the H-theory formalism, which provides a hierarchical intermittency model for the information cascade in the currency market. We examine the distributions of returns and volatilities for the three most traded currency pairs: euro-U.S. dollar, U.S. dollar-Japanese yen, and British pound-U.S. dollar. We find that these markets have a hierarchy of timescales, with larger markets exhibiting more hierarchy levels. We provide a theoretical framework for understanding why the number of levels in the information cascade increases with market size, in analogy with similar behavior for the energy cascade in turbulence as a function of Reynolds number. We briefly argue that using turbulence-like models for financial markets can also provide valuable insights for developing efficient algorithmic trading strategies.
ABSTRACT
Cesium auride (CsAu) is an intriguing compound formed by two metals that, upon reacting, exhibits properties of an ionic salt. In this study, we employ computer simulations to explore the influence of relativistic effects on the structure and some physical properties of CsAu, as well as on a potential pressure-induced structural phase transition, the effect of high pressures on its electronic gap, and the possible transition to a conducting state. We have found that including relativistic effects reduces the lattice parameter of CsAu and brings its volumetric properties closer to the trend observed in alkali halides. It also enhances the charge transfer from cesium to gold, resulting in a difference of up to 0.15e, at ambient pressure, between non-relativistic and fully relativistic calculations. Additionally, upon increasing pressure, in the absence of intervening structural phase transitions, the closing of CsAu's band gap is expected at approximately 31.5 GPa. The inclusion of relativistic effects stabilizes the CsAu Pm3Ìm structure and shifts the transition pressure to a possible high-pressure P4/mmm phase from 2 GPa (non-relativistic calculation) to 14 GPa (fully-relativistic calculation). Both the Pm3Ìm and P4/mmm structures become dynamically unstable around 15 GPa, thus suggesting that the tetragonal structure may be an intermediate state towards a truly stable high-pressure CsAu phase.
ABSTRACT
Microbial lipids are a valuable source of potential biofuels and essential polyunsaturated fatty acids. The optimization of the fermentation conditions is a strategy that affects the total lipid concentration. The genus Nigrospora sp. has been the target of investigations based on its potential bioherbicidal action. Therefore, this study developed a strategy to maximize the biomass concentration and lipid accumulation by Nigrospora sp. in submerged fermentation. Different media compositions and process variables were investigated in shaken flasks and bioreactor in batch and fed-batch modes. Maximum biomass concentration and lipid accumulations were 40.17 g/L and 21.32 wt% in the bioreactor, which was 2.1 and 5.4 times higher than the same condition in shaken flasks, respectively. This study presents relevant information to the production of fungal lipids since few investigations are exploring the fed-batch strategy to increase the yield of fungi lipids, as well as few studies investigating Nigrospora sp. to produce lipids.
Subject(s)
Ascomycota , Bioreactors , Fermentation , Lipids , Biomass , BiofuelsABSTRACT
Butia capitata endocarp (BCE) is a biomass residue with the potential to produce a wide variety of bio-products. The processing of BCE in a sequential process of subcritical water hydrolysis (SWH) and hydrothermal liquefaction (HTL) was investigated to obtain fermentable sugars, platform chemicals, bio-oil, and biochar. The SWH was evaluated at 230 and 260 °C and solvent: feed mass ratios (R) of 10 and 20 for the production of fermentable sugars and platform chemicals. The solid residue from SWH was sequentially submitted to the HTL at 330 and 360 °C for bio-oil and biochar production. The results were analyzed by comparing the sequential (SWH/HTL) and individual (HTL only) processes. The highest yields of fermentable sugars (5.26 g/ 100 g BCE) were obtained for SWH at 260 °C and R-20 with higher contents of xylose (2.64 g/100 g BCE) and cellobiose (1.75 g/100 g BCE). The highest yields of platform chemicals (2.44 g/100 g BCE) were obtained for SWH at 260 °C and R-10 with higher contents of acetic acid (1.78 g/100 g BCE) and furfural (0.54 g/100 g BCE). The highest yield of bio-oil (25.30 g/100 g BCE) occurred in HTL individual process at 360 °C and R-20. Sequential process SWH/HTL showed a decrease in bio-oil yield but maintained a similar biochar yield compared to HTL, in addition to the production of fermentable sugars and platform chemicals.
ABSTRACT
The fungi-based technology provided encouraging scenarios in the transition from a conventionally based economic system to the potential security of sources closely associated with the agricultural sphere such as the agriculture. In recent years, the intensification of fungi-based processes has generated significant gains, additionally to the production of materials with significant benefits and strong environmental importance. Furthermore, the growing concern for human health, especially in the agriculture scenario, has fostered the investigation of organisms with high biological and beneficial potential for use in agricultural systems. Accordingly, this study offered a comprehensive review of the diversity of the soil fungal microbiome and its main applications in a biotechnological approach aimed at agriculture and food chain-related areas. Moreover, the spectrum of opportunities and the extensive optimization platform for obtaining fungi compounds and metabolites are discussed. Finally, future perspectives regarding the insurgency of innovations and challenges on the broad rise of visionary solutions applied to the biotechnology context are provided.
Subject(s)
Mycobiome , Soil , Humans , Agriculture , Biotechnology , Food ChainABSTRACT
AIM: In breast carcinoma (BC), the relationship between the ploidy pattern and molecular subtyping is still unknown. We aim to investigate the prognostic impact of DNA ploidy within molecular subtypes of a large cohort of BC patients. METHODS: The series involved 520 BC patients with no neoadjuvant therapy and a median follow-up of 115.5 months. Immunohistochemical assessment of hormonal receptors, ERBB2 (HER2) status and Ki67 proliferative activity was the basis of the surrogate molecular subtyping. Ploidy was evaluated by DNA flow cytometry in fresh/frozen tumour samples. Kaplan-Meier (K-M) survival estimation was used for prognostic statistical analysis. RESULTS: Luminal A subtype had the lowest prevalence of disease recurrences (23.6 %) and deaths from disease (18.3 %), while Luminal B (42.2 %/37.9 %), Triple-negative (46.4 %/40.6 %), and HER2-positive (55.9 %/50.0 %) subtypes had the highest. The Triple-positive subtype shows an intermediate/low frequency of adverse events (29.4 % of disease recurrences and 17.6 % of deaths from disease). Luminal A tumours were mostly diploid (55.3 %), while Triple-negative and HER2-positive tumours showed a high incidence of aneuploidy (82.6 % and 88.2 %, respectively). Luminal B and Triple-positive tumours had an intermediate percentage of aneuploidy (63.8 % and 70.6 %, respectively). K-M survival curves showed that DNA aneuploidy is significantly associated with shorter disease-free survival and overall survival in Luminal A and Luminal B molecular subtypes. CONCLUSION: DNA aneuploidy identifies a subset of Luminal BC patients with worse clinical outcome, potentially eligible for more aggressive adjuvant therapy.
Subject(s)
Breast Neoplasms , Receptor, ErbB-2 , Humans , Female , Receptor, ErbB-2/analysis , Neoplasm Recurrence, Local , Breast Neoplasms/pathology , Prognosis , Disease-Free Survival , Aneuploidy , DNA , Receptors, Progesterone/analysis , Biomarkers, Tumor/analysisABSTRACT
We present the software ModInterv as an informatics tool to monitor, in an automated and user-friendly manner, the evolution and trend of COVID-19 epidemic curves, both for cases and deaths. The ModInterv software uses parametric generalized growth models, together with LOWESS regression analysis, to fit epidemic curves with multiple waves of infections for countries around the world as well as for states and cities in Brazil and the USA. The software automatically accesses publicly available COVID-19 databases maintained by the Johns Hopkins University (for countries as well as states and cities in the USA) and the Federal University of Viçosa (for states and cities in Brazil). The richness of the implemented models lies in the possibility of quantitatively and reliably detecting the distinct acceleration regimes of the disease. We describe the backend structure of software as well as its practical use. The software helps the user not only to understand the current stage of the epidemic in a chosen location but also to make short term predictions as to how the curves may evolve. The app is freely available on the internet (http://fisica.ufpr.br/modinterv), thus making a sophisticated mathematical analysis of epidemic data readily accessible to any interested user.
ABSTRACT
The relative stability between the crystal structure of α-F2, space group C2/c, and a hypothesized high-pressure phase, space group Cmce, was explored using Density Functional Theory at the PBE0+D3(ABC)/TVZP level of theory and further assessed by Quantum Monte Carlo calculations. The analysis of the phonon dispersion spectra reveals that, at ambient pressure, besides the energy difference favoring the C2/c structure, the Cmce phase also presents a dynamical instability near the Γ-point, which disappears with increasing pressure. The unstable vibrational mode can be related to the absence of σ-holes in the fluorine molecule, which renders a repulsive head-to-head interaction between molecules, as opposed to heavier halogens, in which the presence of σ-holes stabilizes the orthogonal Cmce structure. The results show that the pressure-induced phase transition C2/c â Cmce is of second-order.
ABSTRACT
A generalized pathway model, with time-dependent parameters, is applied to describe the mortality curves of the COVID-19 disease for several countries that exhibit multiple waves of infections. The pathway approach adopted here is formulated explicitly in time, in the sense that the model's growth rate for the number of deaths or infections is written as an explicit function of time, rather than in terms of the cumulative quantity itself. This allows for a direct fit of the model to daily data (new deaths or new cases) without the need of any integration. The model is applied to COVID-19 mortality curves for ten selected countries and found to be in very good agreement with the data for all cases considered. From the fitted theoretical curves for a given location, relevant epidemiological information can be extracted, such as the starting and peak dates for each successive wave. It is argued that obtaining reliable estimates for such characteristic points is important for studying the effectiveness of interventions and the possible negative impact of their relaxation, as it allows for a direct comparison of the time of adoption/relaxation of control measures with the peaks and troughs of the epidemic curve.
ABSTRACT
There are many blackberry cultivars in Brazil; however, the characteristics and applications of the Cherokee cultivar have not yet been widely studied. For this reason, this research investigated the behaviour of maltodextrin (MD), gum Arabic (GA), and pectin (PEC), as carriers combined in different proportions (20% MD, 15% MD + 5% GA, 15% MD + 5% PEC), on encapsulation of Cherokee blackberry pulp extract obtained by freeze-drying. The results of moisture content (2.73-3.36%), water activity (aw) (0.11-0.15), solubility (52.40-54.11%), hygroscopicity (17.59-21.11%), colour (hue 0.24-0.32), retention of anthocyanins (51.55-60.53%), total phenolic compounds (39.72-70.73 mg GAE/100g), antioxidant activity at 25 mg/mL (77.89-80.02%), IC50 (12.26-14.53), simulated in vitro digestion and morphology were discussed. Concerning morphology, blackberry powders had irregular structures and amorphous structures. Comparatively, the best results were obtained for MD-GA. MD-GA presented the highest content of phenolic compounds (70.73 ± 1.84 mg GAE/100g) and antioxidant activity (80.02%), as well as the lowest IC50 value (12.26). In general, all powders showed an increase in phenolic compounds during in vitro digestion, because of the pH conditions and digestive enzymes present in the simulated digestive fluid. This result shows that the wall material provides protection, since the blackberry rich extract (RE) showed degradation of phenolic compounds in in vitro digestion. In this sense, freeze-drying is a suitable technique for the encapsulation of Cherokee blackberry pulp extract.
Subject(s)
Gum Arabic , Rubus , Gum Arabic/chemistry , Antioxidants/chemistry , Rubus/chemistry , Brazil , Pectins , Anthocyanins/chemistry , Drug Compounding/methods , Phenols/chemistryABSTRACT
The influence of age on the outcome of patients with invasive breast carcinoma (IBC) has not yet been fully established. The present study investigated two subgroups of patients either side of the age spectrum, and evaluated cytometric, histopathological and molecular characteristics. The series involved 219 patients with IBC that had long-term follow-up, which were divided into two subgroups: Young (≤45 years; n=103) and old patients (≥75 years; n=116). Immunohistochemical evaluation of hormonal receptors, Ki67 index and HER2 status (plus HER2 silver in situ hybridization in equivocal cases) were used as the basis for surrogate molecular subtyping. Ploidy and S-phase fraction (SPF) were analysed by DNA flow cytometry. Differences between the subgroups' characteristics were assessed by the two proportion Z test. Kaplan-Meier estimation and log-rank test were applied for survival analyses. The median age in the subgroups were 40 years (range, 19-45 years) in the young group and 78 years (range, 75-91 years) in the older subgroup. Young patients exhibited higher lymph node involvement, more advanced disease staging, higher SPF tumour proliferative activity, and a trend of lower incidence of Luminal A and higher incidence of Luminal B tumours. The median SPF value was significantly higher in young patients [7.1% (range, 1.5-23.7%) vs. 4.5% (range, 0.7-26.4%)], whereas the ploidy pattern showed no significant difference. In the whole series, as within IBC of no special type, young patients had a higher rate of recurrence (46.6 vs. 22.4%; P<0.001) and deaths from disease (35.9 vs. 20.7%; P=0.030), with a statistically significant difference for disease-free survival. In conclusion, the present study indicated that young patients with IBC exhibited more aggressive disease, with an increased risk of recurrence and shorter disease-free survival. SPF, lymph node status and staging appeared to be the main prognostic factors to differentiate young from older patients with IBC.
ABSTRACT
The COVID-19 pandemic has proven the importance of mathematical tools to understand the evolution of epidemic outbreaks and provide reliable information to the general public and health authorities. In this perspective, we have developed ModInterv, an online software that applies growth models to monitor the evolution of the COVID-19 epidemic in locations chosen by the user among countries worldwide or states and cities in the USA or Brazil. This paper describes the software capabilities and its use both in recent research works and by technical committees assisting government authorities. Possible applications to other epidemics are also briefly discussed.
ABSTRACT
We offer a new perspective on the problem of characterizing mesoscopic fluctuations in the interplateau regions of the integer quantum Hall transition. We found that longitudinal and transverse conductance fluctuations, generated by varying the external magnetic field within a microscopic model, are multifractal and lead to distributions of conductance increments (magnetoconductance) with heavy tails (intermittency) and signatures of a hierarchical structure (cascade) in the corresponding stochastic process, akin to Kolmogorov's theory of fluid turbulence. We confirm this picture by interpreting the stochastic process of the conductance increments in the framework of H theory, which is a continuous-time stochastic approach that incorporates the basic features of Kolmogorov's theory. The multifractal analysis of the conductance "time series," combined with the H-theory formalism, provides strong support for the overall characterization of mesoscopic fluctuations in the quantum Hall transition as a multifractal stochastic phenomenon with multiscale hierarchy, intermittency, and cascade effects.
ABSTRACT
Undernutrition, anemia, and intestinal parasitic infections are public health problems in Angola, especially in pre-school children. We analyzed binary data from a longitudinal four-arm randomized parallel trial conducted in Bengo Province, northern Angola, over the course of two years, with seven follow-up assessments to explore the effects of four interventions (deworming and a test-and-treat approach for intestinal parasites, at both the individual and household levels) on wasting and stunting, and to understand their indirect benefits for anemia, malaria, diarrhea, and vomiting. A total of 121 children with intestinal parasitic infections received baseline treatment, and were allocated to the four arms (1:1:1:1). Using continuous outcome variables of height-for-age (HAZ) and weight-for-height (WHZ) statistical approaches did not reveal a clear benefit of any particular arm (Pathogens 2021, 10, 309). Next, HAZ and WHZ were transformed into binary variables of stunting and wasting, respectively, considering their mild-to-severe (Z-score < −1) and moderate-to-severe degrees (Z-score < −2). Original clinical data (on anemia, diarrhea, vomiting, and malaria) were also analyzed. From a binary longitudinal analysis with different dependence structures, using the R package bild, fitted models revealed the potential benefit of a test-and-treat approach at the individual level for wasting compared with annual albendazole at the individual level, especially considering mild-to-severe forms (ORadj = 0.27; p = 0.007). All arms showed similar effects on stunting, compared with annual albendazole, at a 5% significance level. Time and age at baseline presented favorable effects in the percentage of stunting using both severity degrees. Results showed a decreased chance of having anemia and diarrhea over time, although with no significant differences between arms. Data from longitudinal studies are essential to study the direct and indirect effects of interventions, such as deworming, and to explore additional approaches aiming at better understanding the temporal structure of nutrition and health outcomes in children.
Subject(s)
Anemia , Intestinal Diseases, Parasitic , Malaria , Parasites , Albendazole/therapeutic use , Anemia/diagnosis , Anemia/drug therapy , Anemia/etiology , Animals , Cachexia , Child , Child, Preschool , Diarrhea/drug therapy , Growth Disorders/drug therapy , Humans , Infant , Intestinal Diseases, Parasitic/diagnosis , Intestinal Diseases, Parasitic/drug therapy , Malaria/complications , Malaria/drug therapy , Prevalence , VomitingABSTRACT
Cell wall degrading enzymes (chitinase and ß-1,3-glucanase) were produced by solid-state fermentation (SSF) using the fungus Trichoderma harzianum and different agro-industrial products, mainly residues. The influence of temperature (25-35 °C), initial moisture content (50-90% w/w), nutrient solution (1-2% v/w), and yeast extract (1-2% w/w) on enzyme activity was evaluated. The application of ultrasound during fermentation for different times (0-6 h/day) was also studied. White rice was the substrate that showed the highest chitinase and ß-1,3-glucanase activities, which were 31.31 U/g for chitinase and 23.83 U/g for ß-1,3-glucanase after 10 days of fermentation. Application of ultrasound waves during fermentation positively affected (p < 0.05) the enzyme activities. The best results for chitinase (51.88 U/g) and ß-1,3-glucanase (39.22 U/g) were obtained with a 50% (w/w) moisture content and 4 h/day ultrasound application for 10 days of fermentation. Increases of 3.6-fold (from 14.37 to 51.88 U/g) and 3.8-fold (from 10.22 to 39.22 U/g) in activities for chitinase and ß-1,3-glucanase, respectively, compared to non-sonicated fermentation, were obtained. Ultrasound technique associated with the SSF process was a promising alternative to increase the production activity of cell wall degrading enzymes: chitinase and ß-1,3-glucanase.
ABSTRACT
The valorization of agro-industrial residues can be improved through their full use, making the production of second-generation ethanol viable. In this scenario, hydrolyzed soybean straw generated from a subcritical water process was applied to the basic fuchsin adsorption. At pH eight, a high adsorption capacity was obtained. The mass test results showed that basic fuchsin's removal and adsorption capacity could be maximized with an adsorbent dosage of 0.9 g L-1. The linear driving force model was suitable for predicting the kinetic profile, and the kinetic curves showed that equilibrium was reached with only 30 min of contact time. Besides, the Langmuir model was the best to predict the adsorption isotherms. The thermodynamic parameters revealed a spontaneous and endothermic process. At 328 K, there is maximum adsorption capacity (72.9 mg g-1). Therefore, it can be stated that this material could be competitive in terms of adsorption capacity coupled with the idea of full use of waste.
Subject(s)
Water Pollutants, Chemical , Water , Adsorption , Ethanol , Hydrogen-Ion Concentration , Kinetics , Rosaniline Dyes , Glycine max , Thermodynamics , Water/chemistry , Water Pollutants, Chemical/chemistryABSTRACT
Supercritical fluids' extraction (SFE) and conventional solvent extraction (CSE) for defatting of quinoa flour as pretreatments to produce the quinoa protein hydrolysate (QPH) were studied. The objective was to extract the oil and separate the phenolic compounds (PC) and the defatted quinoa flour for subsequent quinoa protein extraction and enzymatic hydrolysis. The oil extraction yield (OEY), total flavonoid content (TFC), and QPH yield were compared. SuperPro Designer 9.0® software was used to estimate the cost of manufacturing (COM), productivity, and net present value (NPV) on laboratory and industrial scales. SFE allows higher OEY and separation of PC. The SFE oil showed a higher OEY (99.70%), higher antioxidant activity (34.28 mg GAE/100 g), higher QPH yield (197.12%), lower COM (US$ 90.10/kg), and higher NPV (US$ 205,006,000) as compared to CSE (with 77.59%, 160.52%, US$ 109.29/kg, and US$ 28,159,000, respectively). The sensitivity analysis showed that the sale of by-products improves the economic results: at the industrial scale, no significant differences were found, and both processes are economically feasible. However, results indicate that SFE allows the recovery of an oil and QPH of better nutritional quality and a high level of purity-free organic solvents for further health and nutraceutical uses.
ABSTRACT
This study aimed to verify if microwave hydrodiffusion and gravity (MHG) could efficiently extract anthocyanins from strawberries and raspberries with low environmental impact and costs. Our findings revealed that it was possible to extract 69 and 64% anthocyanins from the strawberries and raspberries in a single extraction step, respectively. When the co-product (product remaining after extracting in natura fruits) was hydrated with green solvents and subjected to re-extraction, it was possible to exhaustively extract the anthocyanins from both fruits. Using the Green Analytical Procedure Index (GAPI), the MHG proved to cause low environmental impact due to the solvents used, enabling the reuse of the co-product for food and pharmaceutical products application. Moreover, the MHG was economically viable, and the sample pretreated with distilled water was the most indicated re-extraction method. The MHG process proved to be exhaustive for strawberry and raspberry anthocyanins, thus demonstrating to be an excellent alternative for sustainable extraction.
Subject(s)
Fragaria , Rubus , Anthocyanins , Fruit , Microwaves , SolventsABSTRACT
This study aimed to evaluate the impact of the ultrasound intensity (0, 5, 10, and 20 W/cm2) on the esterification of annatto (Bixa orellana L.) seed starch with octenyl succinic anhydride (OSA) employing a short processing time (5 min) to produce a novel emulsifier. OSA-esterified annatto seed starches were examined according to their degree of substitution (DS), amylose content, granule size distribution, microstructure, and X-ray diffractogram. Also, the performance of the OSA-modified annatto seed starch to stabilize colloidal systems was compared to commercial samples of OSA-modified starches. For this, annatto seed oil-in-water emulsions were produced and characterized according to their droplet size distribution, microstructure, and kinetic stability. Increasing ultrasound intensity from 5 W/cm2 to 20 W/cm2, DS values reached up to 0.139 ± 0.031. Likewise, these treatments yielded approximately 1.24-1.36 times more amylose content than the sample without ultrasound application. Most of the starch granules presented smooth surfaces without visible fissures. The higher ultrasound intensity hindered the aggregation of starch granules, thus forming well-defined elliptical particles. On the other hand, the increase of the ultrasound intensity did not change Brouckere mean diameter of the starch granules. No significant qualitative differences were seen in the X-ray diffractograms in terms of diffraction angle and peak intensity, indicating that the main functional characteristics of starches were not altered with ultrasound treatment. Furthermore, modified annatto starch was able to stabilize annatto seed oil-in-water emulsions. When compared to two commercial modified starches, OSA-esterified annatto starch produced a colloidal system with a larger Sauter mean diameter (14 ± 2 µm). However, the emulsion stabilized with modified annatto starch was more kinetically stable during the storage time in comparison to those stabilized with commercial starches.
Subject(s)
Amylose , Succinic Anhydrides , Amylose/chemistry , Bixaceae , Emulsions/chemistry , Esterification , Plant Oils/analysis , Seeds/chemistry , Starch/chemistry , Succinic Anhydrides/chemistry , Water/analysisABSTRACT
We present the software ModInterv as an informatics tool to monitor, in an automated and user-friendly manner, the evolution and trend of COVID-19 epidemic curves, both for cases and deaths. The ModInterv software uses parametric generalized growth models, together with LOWESS regression analysis, to fit epidemic curves with multiple waves of infections for countries around the world as well as for states and cities in Brazil and the USA. The software automatically accesses publicly available COVID-19 databases maintained by the Johns Hopkins University (for countries as well as states and cities in the USA) and the Federal University of Vicosa (for states and cities in Brazil). The richness of the implemented models lies in the possibility of quantitatively and reliably detecting the distinct acceleration regimes of the disease. We describe the backend structure of software as well as its practical use. The software helps the user not only to understand the current stage of the epidemic in a chosen location but also to make short term predictions as to how the curves may evolve. The app is freely available on the internet (http://fisica.ufpr.br/modinterv), thus making a sophisticated mathematical analysis of epidemic data readily accessible to any interested user.