Development of active cassava starch cellulose nanofiber-based films incorporated with natural antimicrobial tea tree essential oil

In the present study, a cassava starch-glycerol film with reinforcement of Pinus sp. nanofibers (NFC) incorporated with tea tree (Melaleuca alternifolia) essential oil (TTO) were prepared by casting technique. The physical (barrier, mechanical, and optical), structural, and antimicrobial properties of the films were evaluated and compared with the control films. Films with 0.08% TTO exhibited a significant increase in the tensile strength (TS) while films with 1.5% TTO showed a decrease in TS, suggesting a crosslinking effect. The addition of 1.5% TTO reduced the water vapor permeability values in 43% comparing to the control films. Analysis obtained by Fourier transform infrared spectroscopy showed bands related to the interaction between TTO and matrix for films with 1.5% TTO and 0.3% NFC. This film was effective against Staphylococcus aureus and Candida albicans which could be applied for several packaging purposes. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48726.     

Dietary fish oil and cytochrome P-450 monooxygenase activity in rat liver and kidney

Lauric acid hydroxylation and aminopyrineN-demethylation were studied in kidney and liver microsomes from rats treated with fish oil. Different doses of fish oil containing 20% eicosapentaenoic acid and 10% docosahexaenoic acid were provided daily to the rats for seven days. In all the groups studied, the lauric acid metabolism was higher in kidney microsomes and the aminopyrine metabolism in the liver microsomes. Although no effect on the renal cytochrome P-450 concentration was detectable, all four fish oil doses increased the hepatic concentration of cytochrome P-450 by a mean 27%. The higher fish oil doses used increased the renal and hepatic microsomal metabolism of aminopyrine. The lauric acid metabolism was increased by fish oil only in the liver. Fish oil, a known inducer of fatty acid peroxisomal β-oxidation, also induced microsomal activity. These results show that liver and kidney respond in different ways to dietary factors such as fish oil. In addition, our study would suggest that fish oil increased the activity of two different families of liver cytochrome P-450. The activity of kidney lauric acid 11- and 12-hydroxylation, however, was not modulated by fish oil.     

Multifunctional Nanocrystalline Thin Films of Er2O3: Interplay between Nucleation Kinetics and Film Characteristics

In this study, thin films of Er₂O₃ are deposited by low‐pressure metal–organic chemical vapor deposition (MOCVD) using a tris(isopropylcyclopentadienyl)erbium precursor and O₂ on various substrates, including p‐type Si(100), Si(111), Corning glass, and c‐axis‐oriented α‐Al₂O₃(0001). The resulting films are extensively characterized in order to demonstrate their applicability as antireflective and protective coatings and as high‐k gate dielectrics. The interplay existing among the substrate, the nucleation kinetics, and the resulting structural, morphological, optical, and electrical properties of Er₂O₃ thin films is explored. Fast nucleation governed by surface energy minimization characterizes the growth of (111)‐oriented Er₂O₃ on Si(100), glass, and α‐Al₂O_3. Conversely, nonhomogeneous nucleation leads to polycrystalline Er₂O₃ on Si(111) substrates. Er₂O₃ films grown on Si(100) possess superior characteristics. A high refractive index of 2.1 at 589.3 nm, comparable to the value for bulk single crystalline Er₂O₃, a high transparency in the near UV‐vis range, and an optical bandgap of 6.5 eV make Er₂O₃ interesting as an antireflective and protective coating. A static dielectric constant of 12–13 and a density of interface traps as low as 4.2 × 10¹⁰ cm² eV^–1 for 5–10 nm thick Er₂O₃ layers grown on Si(100) render the present Er₂O₃ films interesting also as high‐k dielectrics in complementary metal oxide semiconductor (CMOS) devices.     

Defeating Colluding Nodes in Desktop Grid Computing Platforms

Desktop Grid systems reached a preeminent place among the most powerful computing platforms in the planet. Unfortunately, they are extremely vulnerable to mischief, because computing projects exert no administrative or technical control on volunteers. These can very easily output bad results, due to software or hardware glitches (resulting from over-clocking for instance), to get unfair computational credit, or simply to ruin the project. To mitigate this problem, Desktop Grid servers replicate work units and apply majority voting, typically on 2 or 3 results. In this paper, we observe that simple majority voting is powerless against malicious volunteers that collude to attack the project. We argue that to identify this type of attack and to spot colluding nodes, each work unit needs at least 3 voters. In addition, we propose to post-process the voting pools in two steps. i) In the first step, we use a statistical approach to identify nodes that were not colluding, but submitted bad results; ii) then, we use a rather simple principle to go after malicious nodes which acted together: they might have won conflicting voting pools against nodes that were not identified in step i. We use simulation to show that our heuristic can be quite effective against colluding nodes, in scenarios where honest nodes form a majority.     

Proteinase inhibition of fish muscle enzymes using legume seed extracts.

Seed extracts from indigenous and introduced legumes were prepared and used to search for inhibitors of fish muscle proteinases. Fish flesh extracts were prepared from samples of Merluccius productus (Pacific whiting or merluza) obtained off the Oregon coast and in the Gulf of California, respectively. The proteinase activity in the fish muscle for the Pacific whiting was the highest, followed by parasitized merluza. The lowest proteinase activity was for the nonparasitized merluza. Six out of 12 seed extracts reduced the proteinase activity from the fish flesh by more than 50%. The reduction of enzyme activity was higher for samples of fish flesh extracts from the Gulf of California than for the Oregon samples. Seed extracts also reduced the proteinase activity of commercial serine and cysteine proteinases such as trypsin, chymotrypsin, and papain. This inhibitory capacity was maintained even after heating the seed extracts to 90 degrees C for 15 min. Several seed extracts show promise for use as proteinase inhibitors during production of surimi, the intended commercial product of massive fisheries such as Pacific whiting or merluza.     

Recovery of manganese from zinc alkaline batteries by reductive acid leaching using carbohydrates as reductant

Acid leaching of manganese from the powders of exhausted zinc alkaline batteries has been studied using carbohydrates as reducing agents. A mono-saccharide (glucose) and a di-saccharide (lactose) have been tested, the second as a template of industrial wastes. Manganese leaching was complete in the presence of both carbohydrates, along with zinc. Data from the factorial test with lactose have been analysed with ANOVA. The most significant effects for manganese extraction were sulphuric acid concentration, temperature, and lactose concentration.     

Interactions among dynamic sets of objects

In this paper, we present an operator to model interactions among objects. Our proposal allows a variable number of participant objects in an interaction, and this number will be fixed during the execution of the model. This provides a very flexible interaction model based on synchronous interactions among several objects. Our interaction model is based on events and allows a multiple-way communication among objects. Concrete values of a communication are generated through constraints which are imposed locally on each participant object. The proposed interaction (and communication) model is very versatile and can be used as an abstract specification mechanism.     

On the Evolution of Vector Distance Functions of Closed Curves

Inspired by the work by Gomes et al., we describe and analyze a vector distance function approach for the implicit evolution of closed curves of codimension larger than one. The approach is set up in complete generality, and then applied to the evolution of dynamic geometric active contours in (codimension three case). In order to carry this out one needs an explicit expression for the zero level set for which we propose a discrete connectivity method. This leads us to make connections with the new theory of cubical homology. We provide some explicit simulation results in order to illustrate the methodology. Electronic supplementary material Electronic supplementary material is available for this article at and accessible for authorised users. First online version published in October, 2005     

Physico-Chemical Model of Toxic Substances in the Great Lakes

A physico-chemical model of the fate of toxic substances in the Great Lakes is constructed from mass balance principles, incorporating principal mechanisms of paniculate sorption-desorption, sediment-water and atmosphere-water interactions, and chemical and biochemical decay. The steady state mass balance model of the suspended solids in the open lake water yields net solids loss rates from 0.02 mjdfor Saginaw Bay to 1.22 m/dfor Lake Ontario. Calibration of the toxic model is through comparison to plutonium-239 data collected in the 1970s using a 23-year time variable calculation. The results indicate that, in general, the sediments are interactive with the water column in the Great Lakes through resuspension and horizontal transport. Fifty percent response times of ²³⁹Pu following a cessation of load extend beyond 10 years with sediment resuspension. The calibrated model was also applied to polychlorinated biphenyl (PCB) using a high and low estimate of contemporary external load and with and without volatilization. The lower load level (lake range 640 to 1,390 kg/yr) with volatilization (at an exchange rate of 0.1 m/d) appears to be more representative of observed surface sediment data for the open lake waters. Calculated water column concentrations for the lower load level with and without volatilization ranged from 0.25 to 0.90 ng/Lfor open lake waters. Fifty percent response times for PCB following cessation of load varied from less than 5 years when volatilization was included to 10 to 20 years without volatilization. Comparison of these response times to decline of concentrations of PCB in Lake Michigan bloaters indicates that, at least for that lake, volatilization is occurring at an exchange rate of about 0.1 m/d.     

The impact of malnutrition on brain development, intelligence and school work performance

The findings from several authors confirm that undernutrition at an early age affects brain growth and intellectual quotient. Most part of students with the lowest scholastic achievement scores present suboptimal head circumference (anthropometric indicator of past nutrition and brain development) and brain size. On the other hand, intellectual quotient measured through intelligence tests (Weschler-R, or the Raven Progressives Matrices Test) has been described positively and significantly correlated with brain size measured by magnetic resonance imaging (MRI); in this respect, intellectual ability has been recognized as one of the best predictors of scholastic achievement. Considering that education is the change lever for the improvement of the quality of life and that the absolute numbers of undernourished children have been increasing in the world, is of major relevance to analyse the long-term effects of undernutrition at an early age. The investigations related to the interrelationships between nutritional status, brain development, intelligence and scholastic achievement are of greatest importance, since nutritional problems affect the lowest socioeconomic stratum with negative consequences manifested in school-age, in higher levels of school dropout, learning problems and a low percentage of students enrolling into higher education. This limits the development of people by which a clear economic benefit to increase adult productivity for government policies might be successful preventing childhood malnutrition.