Strain localization in polycrystalline material with second phase particles: Numerical modeling with application to ice mixtures

We use a centimeter-scale 2-D numerical model to investigate the effect of the presence of a second phase with various volume percent, shape, and orientation on strain localization in a viscoelastic matrix. In addition, the evolution of bulk rheological behavior of aggregates during uniaxial compression is analyzed. The rheological effect of dynamic recrystallization processes in the matrix is reproduced by viscous strain softening. We show that the presence of hard particles strengthens the aggregate, but also causes strain localization and the formation of ductile shear zones in the matrix. The presence of soft particles weakens the aggregate, while strain localizes within the particles and matrix between particles. The shape and the orientation of second phases control the orientation, geometry, and connectivity of ductile shear zones. We propose an analytical scaling method that translates the bulk stress measurements of our 2-D simulations to 3-D experiments. Comparing our model to the laboratory uniaxial compression experiments on ice cylinders with hard second phases allows the analysis of transient and steady-state strain distribution in ice matrix, and strain partitioning between ice and second phases through empirical calibration of viscous softening parameters. We find that the ice matrix in two-phase aggregates accommodates more strain than the applied bulk strain, while at faster strain rates some of the load is transferred into hard particles. Our study illustrates that dynamic recrystallization processes in the matrix are markedly influenced by the presence of a second phase

Multiparametric determination of genes and their point mutations for identification of beta-lactamases

More than half of all currently used antibiotics belong to the beta-lactam group, but their clinical effectiveness is severely limited by antibiotic resistance of microorganisms that are the causative agents of infectious diseases. Several mechanisms for the resistance of Enterobacteriaceae have been established, but the main one is the enzymatic hydrolysis of the antibiotic by specific enzymes called beta-lactamases. Beta-lactamases represent a large group of genetically and functionally different enzymes of which extended-spectrum beta-lactamases (ESBLs) pose the greatest threat. Due to the plasmid localization of the encoded genes, the distribution of these enzymes among the pathogens increases every year. Among ESBLs the most widespread and clinically relevant are class A ESBLs of TEM, SHV, and CTX-M types. TEM and SHV type ESBLs are derived from penicillinases TEM-1, TEM-2, and SHV-1 and are characterized by several single amino acid substitutions. The extended spectrum of substrate specificity for CTX-M beta-lactamases is also associated with the emergence of single mutations in the coding genes. The present review describes various molecular-biological methods used to identify determinants of antibiotic resistance. Particular attention is given to the method of hybridization analysis on microarrays, which allows simultaneous multiparametric determination of many genes and point mutations in them. A separate chapter deals with the use of hybridization analysis on microarrays for genotyping of the major clinically significant ESBLs. Specificity of mutation detection by means of hybridization analysis with different detection techniques is compared

Analysis of Blue Fountain Pen Ink by UV-Vis Spectroscopy, ATR-FTIR Spectroscopy, and Thin Layer Chromatography Enhanced with RGB Spot Evaluation to Construct a Database for Comparison and Identification.

Pen ink can be a crucial piece of physical evidence in the area of Forensic Science. For example, evidence such as notes, letters, printed documents, checks, currency, ransom notes, and books may contain ink. Analysis of ink is typically done for identification or differentiation purposes. To improve existing methods, it was proposed to create a database with many samples and experimental information. The methods used and evaluated were thin-layer chromatography (TLC) enhanced with RGB spot evaluation, UV-Vis spectroscopy, and ATR-FTIR spectroscopy. All three methods were used to analyze 89 fountain pen ink samples. All three methods were able to discriminate between the majority of the ink samples. However, some samples were still similar and difficult to differentiate with a single method. Using more than one method proved advantageous in discriminating more samples

IDENTIFICATION OF FATTY ACIDS IN SACHA INCHI OIL (CURSIVE PLUKENETIA VOLUBILIS L.) FROM ECUADOR

Objective: The aim of this study was to identify fatty acids in a sacha inchi oil sample.Methods: Sacha inchi oil was obtained of sacha inchi seeds using the cold pressing method. Fatty acids analysis was carried out using the gas chromatography with a mass selective detector and using the database Library NIST14.L to identify the compounds.Results: Sacha inchi seeds have a high content of unsaturated fatty acids with 34.98% of ɷ6 α- Linoleic and 47.04% of ɷ3 α- Linolenic. Sacha inchi seeds only have 3.98% of palmitic acid.Conclusions: Sacha inchi seed is a good source of fatty acids ɷ3 and ɷ6, being ɷ3 and ɷ6 in a good proportion. Sacha inchi oil can be used to elaborate functional foods

Reconstructing Native American Population History

The peopling of the Americas has been the subject of extensive genetic, archaeological and linguistic research; however, central questions remain unresolved1–5. One contentious issue is whether the settlement occurred via a single6–8 or multiple streams of migration from Siberia9–15. The pattern of dispersals within the Americas is also poorly understood. To address these questions at higher resolution than was previously possible, we assembled data from 52 Native American and 17 Siberian groups genotyped at 364,470 single nucleotide polymorphisms. We show that Native Americans descend from at least three streams of Asian gene flow. Most descend entirely from a single ancestral population that we call “First American”. However, speakers of Eskimo-Aleut languages from the Arctic inherit almost half their ancestry from a second stream of Asian gene flow, and the Na-Dene-speaking Chipewyan from Canada inherit roughly one-tenth of their ancestry from a third stream. We show that the initial peopling followed a southward expansion facilitated by the coast, with sequential population splits and little gene flow after divergence, especially in South America. A major exception is in Chibchan-speakers on both sides of the Panama Isthmus, who have ancestry from both North and South America

Evaluation of Natural Technological Interfaces for Children with Psychomotor Disabilities

population with disabilities, there is a group that has intellectual, sensory, motor disabilities, or a combination of them. The International Classification of Functioning, Disability and Health (ICF) defines disability as an umbrella term for impairments, activity limitations and participation restrictions. It is estimated that over 15 % of the world´s population is afflicted by disability in some form. In Argentina this prevalence reaches 7.1%. When these people want to use any technological device, usually find that its physical interfaces are not accessible. Often they need adaptations, raising costs but accessibility is not totally guaranteed. Current technologies allow "more natural" interfaces, where the feedback is immediate. The application of appropriate technology with natural or intuitive interfaces, allow greater accessibility than adaptations commonly used for the overall development of students with psychomotor disorders. The objective of this work is to facilitate the comprehensive development of students with senso psychomotor disorders attending the Special School Beatriz Martinez A. Allio, through the incorporation and implementation of natural interfaces for working with computers in education, offering teaching a complementary tool for the development of their daily activities. The interfaces of hardware and software implementation are proposed to achieve the overall goal. It is intended to make at least a touch screen and at least one interface with the Kinect camera game console Xbox 360.Fil: Beltramone, D. A. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Ingeniería Biomédica; Argentina.Fil: Tula, S. M. Ministerio de Educación de la Provincia de Córdoba. Escuela Especial B. A. Martínez Allio; Argentina.Fil: Rivarola, M. F. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Escuela Kinesiología y Fisioterapia; Argentina.Fil: Hidalgo, M. B. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Ingeniería Biomédica; Argentina.Fil: Tancredi, P. D. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Ingeniería Biomédica; Argentina.Fil: Quinteros Quintana, M. L. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Ingeniería Biomédica; Argentina.Fil: Diaz, J. M. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Ingeniería Biomédica; Argentina.Fil: Marcotti, A. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Ingeniería Biomédica; Argentina.Fil: Atea, J. J. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Electrónica; Argentina.Ingeniería Médic

Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016

Influencia de especies arbóreas implantadas sobre parámetros biológicos y bioquímicos en un suelo forestal de Chubut, Argentina

87-92The influence of some tree species on biological and biochemical properties of a forest soil was studied with the purpose of establishing criteria to achieve a sustainable development of a forest system. The study site is a forest soil of Chubut, in the Argentinean Patagonia. Surface soil samples were taken of three plots with a dominant species each one: Oak (Quercus robur), Ash (Fraxinus excelsior L.) and Radiata Pine (Pinus radiata D. Don.). Microbial respiration, dehydrogenase and acid phosphatase activities, counts of aerobic and amylolytic bacteria, actinomyces and fungi were determined in soil samples, while phosphorous was determines in leaves. The results showed important differences of these parameters for the different species considered in the study, differences that are explained by the different chemical composition of the vegetal species

Desarrollo de productos de arándanos con propiedades antioxidantes y probióticas

Se estudiaron alternativas de industrialización de arándanos mediante la obtención de productos con propiedades funcionales. Se elaboró jugo de arándanos (JA) despectinizando con 4mg de enzima LAFASE®-CLARIFICATION/100g arándanos y 8mg enzima LAFASE®-HE-GRAND-CRU/100g arándanos a 50°C durante 1,3h. En estas condiciones se maximizaron el rendimiento de extracción de jugo y la concentración de antocianinas totales (AT). Para estabilizar el JA se optimizó el baremo temperatura-tiempo de pasteurización en 77°C y 85s, lo que posibilitó la obtención de jugo de arándanos pasteurizado (JAP) con altas concentraciones de AT. Al JAP se incorporaron bacterias probióticas de Lactobacillus rhamnosus, obteniendo jugo de arándanos con probióticos (JACP). Las mejores condiciones de almacenamiento para el jugo de arándanos fueron como JAP almacenado a 0°C durante 300 días y como JACP a 0°C durante 30 días. El JAP se utilizó para impregnar rodajas de manzana y zucchini y potenciar sus propiedades funcionales. Las rodajas fueron deshidratadas a 40, 50 y 60°C para obtener snacks enriquecidos con antocianinas. El modelo de Page describió adecuadamente la cinética de deshidratación. A 60°C se logró la mayor retención de AT y el menor tiempo de deshidratación, lo que es de interés desde el punto de vista tecnológic

Synergistic effect of acetazolamide-(2-hydroxy)propyl β-cyclodextrin in timolol liposomes for decreasing and prolonging intraocular pressure levels

The purpose of this study was to design, for the first time, a co-loaded liposomal formulation (CLL) for treatment of glaucoma including timolol maleate (TM) in the lipid bilayer and acetazolamide (Acz)-(2-hydroxy)propyl β-cyclodextrin (HPβCD) complexes (AczHP) solubilized in the aqueous core of liposomes. Formulations with TM (TM-L) and AczHP (AczHP-L), separately, were also prepared and characterized. A preliminary study comprising the Acz/HPβCD complexes and their interaction with cholesterol (a component of the lipid bilayer) was realized. Then, a screening study on formulation factors affecting the quality of the product was carried out following the design of the experiment methodology. In addition, in vitro release and permeation studies and in vivo lowering intraocular pressure (IOP) studies were performed. The results of the inclusion com-plexation behavior, characterization, and binding ability of Acz with HPβCD showed that HPβCD could enhance the water solubility of Acz despite the weak binding ability of the complex. Ch disturbed the stability and solubility parameters of Acz due to the fact of its competence by CD; thus, Chems (steroid derivative) was selected for further liposome formulation studies. The optimization of the lipid bilayer composition (DDAB, 0.0173 mmol and no double loading) and the extrusion as methods to reduce vesicle size were crucial for improving the physico-chemical properties and encapsulation efficiency of both drugs. In vitro release and permeation studies demonstrated that the CLL formulation showed improvement in in vitro drug release and permeation compared to the liposomal formulations with a single drug (TM-L and AczHP-L) and the standard solutions (TM-S and AczHP-S). CLL showed high efficacy in reducing and prolonging IOP, suggesting that the synergistic effect of TM and Acz on aqueous humor retention and the presence of this cyclodextrin and liposomes as permeation enhancers are responsible for the success of this strategy of co-loading for glaucoma therapy.Junta de Andalucía 2017/CTS214Universidad de Sevilla PPI546/202