bluuebunny/crossref_metadata_2025 huggingface dataset:
Performance comparison of mixed mode and indirect mode parallel flow forced convection solar driers for drying Curcuma zedoaria
Authors: Lakshmi Durga V. N. , Muthukumar Palanisamy , Ekka Jasinta P. , Nayak Prakash K. , Layek Apurba
Published: March 2019

This study focuses on energy and drying kinetic analyses of Curcuma zedoaria (white turmeric) dried in mixed and indirect active parallel flow solar dryers. Dryer efficiency, specific energy consumption and drying rate are studied. The overall dryer efficiency of mixed mode (MFSCD) is 26.5% higher than indirect mode (IFSCD) solar dryer. Two term model and Verma model fit best for Curcuma zedoaria drying in MFSCD and IFSCD, respectively, and Logarithmic model is quite suitable for open sun drying (OSD). The effective moisture diffusivity of the product dried under MFSCD is highest as compared to IFSCD and OSD products. The quality analyses show that higher values of TFC (78.11 mg GAE/g of sample) and DPPH (120.56 μ mol of TE/g of sample) are reported in the samples dried in MFSCD as compared to IFSCD and OSD samples.

Practical applications

Conventional open sun drying is a common practice followed by small farmers for drying herbs and spices. Products dried under open sun lose their nutritional and medicinal values due to slow drying rate and improper heating. The present work focusses on the development of a low cost solar dryer for drying of high value medicinal herbs like Curcuma zedoaria, curcuma caesia, and black cardamom. Study of drying kinetics helps in improving the design aspects of solar dryer and optimization of the drying systems. Drying time of the Curcuma zedoaria dried in the developed dryer is about 60% less than the open sun drying and the retention of color, antioxidant, and texture of the solar dried products is excellent. The developed solar dryer will be suitable for small small‐scale farmers and can be scaled up to any size.
Effect of ethanolic extraction, thermal vacuum concentration, ultrafiltration, and spray drying on polyphenolic compounds of tropical highland blackberry (Rubus adenotrichos Schltdl.) by‐product
Authors: Quirós Ana M. , Acosta Oscar G. , Thompson Eduardo , Soto Marvin
Published: March 2019

Tropical highland blackberry by‐product (BBP) has high amounts of polyphenols including ellagitannins (ET) and anthocyanins (ATC). Information of the effect of different operations on ET is scarce. In this study, pseudo‐first and first order kinetic models and response surface methodology were applied to optimize the extraction of polyphenols from BBP using ethanol, a food grade solvent. Retention of total polyphenols, ET and ATC was analyzed considering their contents before and after the application of thermal vacuum concentration, ultrafiltration, and spray drying. The optimal conditions for extraction were: a 3.4 solvent/BBP ratio, 57.1% ethanol, 60.0°C, and 120 min extraction time. Thermal vacuum concentration showed a higher retention of ET. A higher purity of ET was accomplished with ultrafiltration. These results provide the basis for further research on the development of a powder enriched with polyphenols, mainly ET, from BBP for food and pharmacological purposes.

Practical applications

Ellagitannins (ET) are a group of polyphenols found in tropical highland blackberries grown in Costa Rica, mainly in their seeds that are discarded as a by‐product (BBP) during blackberry processing. The production process of an ingredient with high amounts of ET has not been widely reported. In this study, modeling and optimization of an ethanolic extraction of polyphenols from BBP, and the effects of thermal vacuum concentration, ultrafiltration and spray drying on polyphenolic compounds were analyzed. This information will lead to further experiments on the effective recovery of ET in order to produce a nutraceutical product, which is not only complementary to the diet, but may also aid in the prevention and treatment of diseases, or an ingredient to be used in the production of functional foods.
Incidence of development of hepatocellular carcinoma in Japanese patients infected with hepatitis B virus is equivalent between genotype B and C in long term
Authors: Haga Hiroaki , Saito Takafumi , Okumoto Kazuo , Tomita Kyoko , Katsumi Tomohiro , Mizuno Kei , Nishina Taketo , Watanabe Hisayoshi , Ueno Yoshiyuki
Published: March 2019

Hepatitis B virus (HBV) genotypes B (HBV/B) and C (HBV/C) are the most prevalent genotypes among Japanese patients with hepatitis. Reportedly, HBV/C infection has been associated with more severe disease progression, manifesting as developing cirrhosis and hepatocellular carcinoma (HCC), than HBV/B infection. However, no long‐term studies have examined the development of HCC in HBV/B‐infected patients in Japan. The aims of our study were to compare the incidence of HCC in HBV/B‐ or HBV/C‐infected patients. A total of 241 patients were followed up among 295 hepatitis B surface antigen (HBsAg)‐positive carriers. Genotypes of HBV were A in 1% (4/295), B in 61% (179/295), C in 37% (110/295) and D in 1% (2/295) patients, and 96% of HBV/B were infected with subgenotype Bj. The mean age at HCC diagnosis was significantly higher in HBV/B than in HBV/C (67.0 ± 10.0 vs 57.7 ± 8.0 years, P < 0.001). The value of FIB‐4 index was significantly higher in HBV/B than in HBV/C (P < 0.01). The rate of HCC was higher in HBV/C than in HBV/B, and a significant difference was observed until the 20‐year observation period (P = 0.048). However, thereafter, HCC associated with HBV/B increased, and no significant difference was observed between HBV/B and HBV/C. HCC development was consistently observed even in HBV/B infection, especially among elderly patients with advanced fibrosis compared with HBV/C. HBV/B‐infected patients developed HCC later in life, and in the long term, we found no differences in incidence of HCC development rates between these two genotypes.
Antimicrobial‐resistant bacterial infections from foods of animal origin: understanding and effectively communicating to consumers
Authors: Ritter G. Donald , Acuff Gary R. , Bergeron Gilles , Bourassa Megan W. , Chapman Benjamin J. , Dickson James S. , Opengart Kenneth , Salois Matthew Jude , Singer Randall S. , Storrs Carina
Published: March 2019

Consumers are increasingly interested in the attributes of the food they consume. This includes what is in the food and how it was raised; and at least some consumers are willing to pay a premium for products with specific attributes. However, the current plethora of labels on the market does not adequately address this issue; rather than providing actionable information, most labels add to the consumer confusion. In addition, there is a tendency toward “absence labels” that can contribute to a negative consumer perception of conventional products that may or may not include the attribute in question. Communication with consumers about the complex and highly technical issue of antimicrobial resistance (AMR) is challenging, and experiences from communication efforts about food safety–related issues demonstrate exactly how challenging this is to communicate clearly. General lessons learned from the science of risk communication can help guide efforts to communicate about the challenging issue of AMR. There are efforts underway to chart out a new approach. A new labeled animal production certification program is under development to provide choice for consumers, while reducing consumer confusion, which mandates antibiotic stewardship practices.
Management and clinical outcomes after lung transplantation in patients with pre‐transplant Mycobacterium abscessus infection: A single center experience
Authors: Perez Alyssa A. , Singer Jonathan P. , Schwartz Brian S. , Chin‐Hong Peter , Shah Rupal J. , Kleinhenz Mary Ellen , Gao Ying , Venado Aida , Leard Lorriana E. , Golden Jeffrey A. , Kukreja Jasleen , Greenland John R. , Hays Steven R.
Published: March 2019

Background

Preoperative Mycobacterium abscessus infection is often considered a contraindication to lung transplantation because of its association with poor outcomes after transplant. Detailed strategies for bridging to transplant, post‐operative management, and data regarding outcomes are lacking.

Methods

We reviewed outcomes in subjects with M abscessus infection who underwent lung transplantation between 2010 and 2018 at the University of California San Francisco. M abscessus infection was defined by American Thoracic Society (ATS) criteria. Data collected included age, FEV1, BMI, LAS, antibiotic regimens, and other management decisions. Time to chronic lung allograft dysfunction (CLAD) and survival were also assessed.

Results

Of 387 lung transplant recipients, seven were infected with M abscessus at the time of listing. All received multiple antibiotics before transplant. While all subjects converted to smear negative for acid‐fast bacilli before listing, five of the seven remained culture‐positive at the time of transplant. After transplant, subjects received a median of 6 months of a multi‐antibiotic regimen. One subject developed a post‐operative M abscessus soft tissue infection that was treated medically. Six of the seven subjects survived the observation period; one died unrelated to M abscessus. Time to CLAD and survival were similar to a contemporary comparator group of CF transplant recipients.

Conclusion

Lung transplant recipients with M abscessus infection have a low incidence of recurrent infection, excellent survival, and freedom from CLAD when an aggressive management and surveillance strategy is utilized. Given these findings, M abscessus infection may not be considered a contraindication to lung transplantation.
The Geographical Tradition on the move: The transnational travels of a classic
Authors: Ferretti Federico
Published: March 2019

Engaging in a dialogue with the other contributors to this forum on spatialities of science and the deepening of historical work on geographical thought in the last few decades, I reflect on the impact of The Geographical Tradition on geographical traditions other than the Anglo‐American one, analysing its citations and receptions in scholarly publications in French, Portuguese, Spanish, and Italian.
Modular organization of murine locomotor pattern in the presence and absence of sensory feedback from muscle spindles
Authors: Santuz Alessandro , Akay Turgay , Mayer William P. , Wells Tyler L. , Schroll Arno , Arampatzis Adamantios
Published: March 2019

Key points

Locomotion on land and in water requires the coordination of a great number of muscle activations and joint movements.

Constant feedback about the position of own body parts in relation to the surrounding environment and the body itself (proprioception) is required to maintain stability and avoid failure.

The central nervous system may follow a modular type of organization by controlling muscles in orchestrated groups (muscle synergies) rather than individually.

We used this concept on genetically modified mice lacking muscle spindles, one of the two main classes of proprioceptors.

We provide evidence that proprioceptive feedback is required by the central nervous system to accurately tune the modular organization of locomotion.

For exploiting terrestrial and aquatic locomotion, vertebrates must build their locomotor patterns based on an enormous amount of variables. The great number of muscles and joints, together with the constant need for sensory feedback information (e.g. proprioception), make the task of controlling movement a problem with overabundant degrees of freedom. It is widely accepted that the central nervous system may simplify the creation and control of movement by generating activation patterns common to muscle groups, rather than specific to individual muscles. These activation patterns, called muscle synergies, describe the modular organization of movement. We extracted synergies through electromyography from the hind limb muscle activities of wild‐type and genetically modified mice lacking sensory feedback from muscle spindles. Muscle spindle‐deficient mice underwent a modification of the temporal structure (motor primitives) of muscle synergies that resulted in diminished functionality during walking. In addition, both the temporal and spatial (motor modules) components of synergies were severely affected when external perturbations were introduced or when animals were immersed in water. These findings show that sensory feedback from group Ia/II muscle spindles regulates motor function in normal and perturbed walking. Moreover, when group Ib Golgi tendon organ feedback is lacking due to enhanced buoyancy, the modular organization of swimming is almost completely compromised.
Comparación entre ancianos sanos con alta y baja reserva cognitiva y ancianos con deterioro cognitivo
Authors: Melendez Moral Juan Carlos , Mayordomo Rodríguez Teresa , Sales Galán Alicia
Published: March 2019

Este trabajo presenta la comparación de las características de sujetos con alta y baja reserva cognitiva, y sujetos con baja reserva cognitiva y deterioro cognitivo, diferenciados a partir del desarrollo de una medida ponderada de reserva cognitiva. Mediante un diseño correlacional se evaluaron 200 personas con edad superior a 65 años, no institucionalizados. Los resultados mostraron, por un lado, que el grupo de alta reserva cognitiva obtuvo mejores puntuaciones tanto en el nivel de deterioro cognitivo como en la medida ponderada de reserva que el grupo de baja reserva cognitiva y, por otro lado, el grupo de baja reserva cognitiva mostró un perfil similar al del grupo de deterioro cognitivo, existiendo solamente diferencias en cuanto a la edad. Las diferencias observadas permiten plantear la medida como una variable que se debe tener en cuenta en el diagnóstico de enfermedades neurodegenerativas y su utilidad para establecer posibles tratamientos.
Theoretical Assessment of Convective and Radiative Heat Losses in a One-Dimensional Multiregion Premixed Flame With Counter-Flow Design Crossing Through Biofuel Particles
Authors: Bidabadi Mehdi , Hosseinzadeh Saman , Sadeghi Sadegh , Setareh Mostafa
Published: March 2019

Due to perspective of biomass usage as a viable source of energy, this paper suggests a potential theoretical approach for studying multiregion nonadiabatic premixed flames with counterflow design crossing through the mixture of air (oxidizer) and lycopodium particles (biofuel). In this research, convective and radiative heat losses are analytically described. Due to the properties of lycopodium, roles of drying and vaporization are included so that the flame structure is created from preheating, drying, vaporization, reaction, and postflame regions. To follow temperature profile and mass fraction of the biofuel in solid and gaseous phases, dimensionalized and nondimensionalized forms of mass and energy balances are expressed. To ensure the continuity and calculate the positions of drying, vaporization, and flame fronts, interface matching conditions are derived employing matlab and mathematica software. For validation purpose, results for temperature profile is compared with those provided in a previous research study and an appropriate is observed under the same conditions. Finally, changes in flame velocity, flame temperature, solid and gaseous fuel mass fractions, and particle size with position measured from the position of stagnation plane, strain rate, and heat transfer coefficient in the presence/absence of losses are evaluated.
Natural history museums face their own past
Authors: Vogel Gretchen
Published: March 2019

Curators confront colonial-era exploitation in the acquisition of dinosaurs, other specimens.
Designer membraneless organelles enable codon reassignment of selected mRNAs in eukaryotes
Authors: Reinkemeier Christopher D. , Girona Gemma Estrada , Lemke Edward A.
Published: March 2019

How to make an organelle in eukaryotes

A key step in the evolution of complex organisms like eukaryotes was the organization of specific tasks into organelles. Reinkemeier
et al.
designed an artificial, membraneless organelle into mammalian cells to perform orthogonal translation. In response to a specific codon in a selected messenger RNA, ribosomes confined to this organelle were able to introduce chemical functionalities site-specifically, expanding the canonical set of amino acids. This approach opens possibilities in synthetic cell engineering and biomedical research.

Science
, this issue p.
eaaw2644
Characterization of Carbapenemase-Producing Klebsiella oxytoca in Spain, 2016–2017
Authors: Pérez-Vazquez María , Oteo-Iglesias Jesús , Sola-Campoy Pedro J. , Carrizo-Manzoni Hugo , Bautista Verónica , Lara Noelia , Aracil Belén , Alhambra Almudena , Martínez-Martínez Luis , Campos José ,   the Spanish Antibiotic Resistance Surveillance Program Collaborating Group, Sánchez-Romero Isabel , Orden Beatriz , Martínez-Ruiz Rocío , Aznar Esteban , Cercenado Emilia , de la Iglesia Pedro , López-Urrutia Luis , Salso Santiago , Vicente Saz José , Reyes Sagrario , Cobos José , García-Picazo Luisa , Ortega-Lafont María , Megías-Lobón Gregoria , Andrés Noelia Arenal , Tarazona Elisa Rodríguez , Álvarez-García Patricia , Fontanals Dionisia , Carranza Rafael , Hernando Susana , Fe Brezmes M. , Ruiz-Velasco Luis Moisés , Cascales Paloma , Guerrero Carmen , Yolanda Gil , Rodríguez-Conde Irene , Saez Alicia
Published: March 2019

There is little information about carbapenemase-producing (CP)
Klebsiella oxytoca
, an important nosocomial pathogen. We characterized CP
K. oxytoca
isolates collected from different Spanish hospitals between January 2016 and October 2017.
Macular thickness amplitude changes when switching from discontinuous to continuous therapy for diabetic macular oedema
Authors: Schechet Sidney A , Adams Olufemi E , Eichenbaum David A , Hariprasad Seenu M
Published: March 2019

Objective

To investigate if the mean central retinal thickness (CRT) amplitude, measured between visits, is consistently decreased when switching from discontinuous to continuous therapy for diabetic macular oedema (DME) following fluocinolone acetonide (FAc) administration.

Methods and analysis

In this retrospective cohort study, all patients with DME treated with FAc at a single centre were included. The primary outcome was CRT amplitude changes measured at each visit prior to and after FAc administration. Secondary outcomes included average number of DME treatments before and after FAc injection, visual acuity and intraocular pressure changes.

Results

Nineteen eyes were included. The mean (SD) follow-up after FAc was 399 (222) days. The mean (SD) CRT amplitude before FAc was 194.6 (114.90) µm, and following FAc administration, the amplitude decreased to 70.8 (94.23) µm (95% CI −189.5 to −58.1; p≤0.001). After FAc, the number of treatments required per month significantly decreased from an average of 1 treatment every 2.7 months to every 6 months (p=0.009).

Conclusion

In patients with DME, the CRT amplitude values and number of treatments significantly decrease following FAc administration while maintaining vision. Further studies are needed to evaluate the significance of these interesting findings.
Clinical pharmacokinetics and pharmacodynamics of intravenous alfaxalone in young Thoroughbred horses premedicated with medetomidine and midazolam
Authors: Wakuno Ai , Aoki Motoki , Kushiro Asuka , Mae Naomi , Maeda Tatsuya , Yamazaki Yosuke , Minamijima Yohei , Nagata Shun‐ichi , Ohta Minoru
Published: March 2019

To investigate the clinical pharmacokinetics and pharmacodynamics of intravenous alfaxalone in young Thoroughbred horses, seven Thoroughbred horses were randomly anaesthetised twice with either 1 or 2 mg/kg of intravenous alfaxalone after premedication with medetomidine (6 µg/kg intravenous) and midazolam (20 µg/kg intravenous). Blood samples were collected at predetermined time points up to two hours after administration. Plasma alfaxalone concentrations were quantified by a liquid chromatography tandem‐mass spectrometry method and analysed by non‐compartmental pharmacokinetic analysis. Induction and recovery qualities were good to excellent for both doses. Recovery time for the 2 mg/kg (median 90 minutes) was significantly longer than that for the 1 mg/kg (median 50 minutes). Respiratory rate for the 2 mg/kg was significantly lower than that for the 1 mg/kg, resulting in hypoxaemia. The median (range) elimination half‐life, total clearance and volume of distribution were 58.2 (42.3–70.7) minutes, 11.6 (10.3–14.5) ml/minute/kg and 0.8 (0.7–0.9) l/kg for the 1 mg/kg and 59.8 (47.5–68.0) minutes, 14.7 (12.1–16.0) ml/minute/kg and 0.9 (0.9–1.2) l/kg for the 2 mg/kg, respectively. Alfaxalone is rapidly eliminated from the plasma in young Thoroughbred horses. Respiratory depression should be especially noted when alfaxalone is used in clinical practice.
The influence of natural and synthetic fibers on mixed mode I/II fracture behavior of cement concrete materials
Authors: Karimzadeh Hossein , Razmi Ali , Imaninasab Reza , Esminejad Afshin
Published: March 2019

This paper evaluated mixed mode I/II fracture toughness of fiber-reinforced concrete using cracked semi-circular bend (SCB) specimens subjected to three-point bending test. Additionally, a comparison was made between the experimental results and the estimations made by different theoretical criteria. Natural and synthetic fibers at various concentrations were used in this study. After producing cracks in SCB specimens at different inclination angles to induce different mixed mode loading conditions (from pure mode I to II), the fracture toughness of SCB specimens was determined. Furthermore, the compressive, splitting tensile, and flexural strength of natural and synthetic fiber-reinforced concrete were measured after 7 and 28 days of curing. While there is an increase in the aforementioned strengths with fiber content increase, 0.3% was found to be the optimum percentage regarding fracture toughness for both fibers. Also, the comparison between the experimental and theoretical results showed that generalized maximum tangential stress criterion estimated the experimental data satisfactorily.
Roughness prediction models using pavement surface distresses in different Canadian climatic regions
Authors: Patrick Graeme , Soliman Haithem
Published: March 2019

The correlation between the international roughness index (IRI) and distress is inherent, as roughness is a function of both the changes in elevation of the distress-free pavement surface and the changes in elevation due to existing surface distress. In this way, a relationship between existing surface distress and IRI may be developed. However, the susceptibility of pavement to various types of surface distress is affected by many factors, including climatic conditions. A model that relates pavement surface distress to IRI for Canada needs to account for climatic conditions in different locations. This paper investigates the relationship between pavement surface distresses and IRI for different climatic conditions in Canada using historical data collected at numerous pavement test section locations sourced from the Long-Term Pavement Performance program database. Developed models were calibrated then validated and found to be statistically significant.
Reduced Basis Method Applied to Eigenvalue Problems from Convection
Authors: Pla Francisco , Herrero Henar
Published: March 2019

The reduced basis method is a suitable technique for finding numerical solutions to partial differential equations that must be obtained for many values of parameters. This method is suitable when researching bifurcations and instabilities of stationary solutions for partial differential equations. It is necessary to solve numerically the partial differential equations along with the corresponding eigenvalue problems of the linear stability analysis of stationary solutions for a large number of bifurcation parameter values. In this paper, the reduced basis method has been used to solve eigenvalue problems derived from the linear stability analysis of stationary solutions in a two-dimensional Rayleigh–Bénard convection problem. The bifurcation parameter is the Rayleigh number, which measures buoyancy. The reduced basis considered belongs to the eigenfunction spaces derived from the eigenvalue problems for different types of solutions in the bifurcation diagram depending on the Rayleigh number. The eigenvalue with the largest real part and its corresponding eigenfunction are easily calculated and the bifurcation points are correctly captured. The resulting matrices are small, which enables a drastic reduction in the computational cost of solving the eigenvalue problems.
2D Triangular von Neumann Cellular Automata with Periodic Boundary
Authors: Uguz Selman , Acar Ecem , Redjepov Shovkat
Published: March 2019

Cellular automata (CA) theory is a very rich and useful model of a discrete dynamical system that focuses on their local information relying on the neighboring cells to produce CA global behaviors. Although the main structure of CA is a discrete special model, the global behaviors at many iterative times and on big scales can be close to nearly a continuous system. The mathematical points of the basic model imply the computable values of the mathematical structure of CA. After modeling the CA structure, an important problem is to be able to move forwards and backwards on CA to understand their behaviors in more elegant ways. This happens in the possible case if CA is a reversible one. In this paper, we investigate the structure and the reversibility cases of two-dimensional (2D) finite, linear, and triangular von Neumann CA with periodic boundary case. It is considered on ternary field [Formula: see text] (i.e. 3-state). We obtain the transition rule matrices for each special case. It is known that the reversibility cases of 2D CA is generally a very challenging problem. For given special triangular information (transition) rule matrices, we prove which triangular linear 2D von Neumann CA is reversible or not. In other words, the reversibility problem of 2D triangular, linear von Neumann CA with periodic boundary is resolved completely over ternary field. However, the general transition rule matrices are also presented to establish the reversibility cases of these special 3-states CA. Since the main CA structures are sufficiently simple to investigate in mathematical ways and also very complex for obtaining chaotic models, we believe that these new types of CA can be found in many different real life applications in special cases e.g. mathematical modeling, theoretical biology and chemistry, DNA research, image science, textile design, etc. in the near future.
Multiple Bifurcation Analysis in a Diffusive Eco-Epidemiological Model with Time Delay
Authors: Babakordi Nayyereh , Zangeneh Hamid R. Z. , Ghahfarokhi Mojtaba Mostafavi
Published: March 2019

In this paper, a delayed eco-epidemiological model with diffusion effects and homogeneous Neumann boundary conditions is proposed. Sufficient conditions for the occurrence of the Hopf-zero, Takens–Bogdanov and saddle-node bifurcations at several steady states are derived. By taking the delay as the bifurcation parameter, it was shown that spatially homogeneous and nonhomogeneous Hopf bifurcations occur at several steady states for a sequence of critical values of the delay parameter. In addition, by applying the normal form theory and center manifold theorem for partial functional differential equations, we present the explicit formula for determining the properties of spatial Hopf bifurcations. Some numerical simulations are carried out.
Spiral Tip Identification via Deterministic Learning
Authors: Dong Xunde , Song Chen , Wang Cong
Published: March 2019

A spiral tip can be considered as a wave source, i.e. a wave is sent out after the tip rotates one circle. Therefore, the dynamics of the spiral tip is vital to understand the behavior of spiral waves. In this paper, we study the spiral tip dynamics from a new perspective by using deterministic learning. A Barkley model described by partial differential equations (PDEs) is employed to illustrate the method. It is first transformed into a set of ordinary differential equations (ODEs) by using finite difference method. Then, the position states of spiral tip are extracted from the spiral wave generated by the transformed Barkley model by using an isocontour method. Finally, with the recurrent trajectory of spiral tip, its dynamics is accurately identified by using the deterministic learning theory. It is shown that the dynamics underlying the periodic or recurrent trajectory of spiral tips can be accurately identified by using the proposed approach. Numerical experiments are included to demonstrate the effectiveness and feasibility of the proposed method.
Various Shadowing in Linear Dynamical Systems
Authors: Wu Xinxing , Zhang Xu , Ma Xin
Published: March 2019

This paper proves that the linear transformation [Formula: see text] on [Formula: see text] has the (asymptotic) average shadowing property if and only if [Formula: see text] is hyperbolic, where [Formula: see text] is a nonsingular matrix, giving a positive answer to a question in [Lee, 2012a]. Besides, it is proved that [Formula: see text] does not have the [Formula: see text]-shadowing property, thus does not have the ergodic shadowing property for every nonsingular matrix [Formula: see text].
Crystallization Behavior of Pure n-Alkane (n-Nonadecane) in a form of Nanoemulsion
Authors: Kuryakov V. N. , Ivanova D. D.
Published: March 2019

Stable emulsions of individual n-alkane (n-nonadecane) in water with different average particle size were prepared without surfactants. The phase transition temperatures for n-nonadecane were determined by the dynamic light scattering method. The effect of the n-alkane particle size on the melting and crystallization temperatures was studied. The crystallization temperature significantly decreases for particles smaller than a certain characteristic value.
Fabrication and Properties of Molybdenum Disulfide Films for Electro-Optical Applications
Authors: Ozcelik S. , Akcay N. , Tivanov M.
Published: March 2019

MoS2 films on sapphire and SiO2/Si substrates were fabricated by sulfurization of sputtered Mo precursor films at 900∘C in a two-zone furnace. Structural, morphological, optical and electrical properties of the films were determined. The films of MoS2 were successfully grown on the substrates with polycrystalline structures and proposed to be used in electro-optical devices.
Characteristics of CZTSSe Thin Films Prepared by Selenization of Sputtered Cu, Sn and ZnS Layers
Authors: Akcay N. , Ozcelik S. , Zaretskaya E. , Juskenas R.
Published: March 2019

We reported the growth of CZTSSe thin films on Mo-coated SLG substrates by the two-step approach which includes the deposition of precursor films by the magnetron sputtering method at room temperature followed by selenization of the precursor films at 560∘C. Formation of CZTSSe films with the kesterite structure was confirmed by XRD and Raman spectroscopy analyses. The films are slightly Cu-rich and Zn-deficient. SEM study shown that the films have uniform surface morphology and densely packed structure without any voids and cracks.
Chinese Economy 2018: Transforming Economic Structures and Stabilising Growth
Authors: QIAN Jiwei
Published: March 2019

China’s economy ended 2018 with 6.6% growth. Its recent supply-side structural reforms to manage the transition of its economy from an investment-driven to an innovation-driven growth model may have some achievements, but the China-US trade war and high debt level of corporations and local governments are among the major uncertainties for the Chinese economy. Since mid-2018, the government has modified its policy priorities, from a strong emphasis on structural reforms to measures that safeguard growth.
A parallel Fortran framework for neural networks and deep learning
Authors: Curcic Milan
Published: March 2019

This paper describes neural-fortran, a parallel Fortran framework for neural networks and deep learning. It features a simple interface to construct feed-forward neural networks of arbitrary structure and size, several activation functions, and stochastic gradient descent as the default optimization algorithm. Neural-fortran also leverages the Fortran 2018 standard collective subroutines to achieve data-based parallelism on shared- or distributed-memory machines. First, I describe the implementation of neural networks with Fortran derived types, whole-array arithmetic, and collective sum and broadcast operations to achieve parallelism. Second, I demonstrate the use of neural-fortran in an example of recognizing hand-written digits from images. Finally, I evaluate the computational performance in both serial and parallel modes. Ease of use and computational performance are similar to an existing popular machine learning framework, making neural-fortran a viable candidate for further development and use in production.
(Pro)renin receptor knockdown in the paraventricular nucleus of the hypothalamus attenuates hypertension development and AT1 receptor-mediated calcium events
Authors: Souza Lucas A. C. , Worker Caleb J. , Li Wencheng , Trebak Fatima , Watkins Trevor , Gayban Ariana Julia B. , Yamasaki Evan , Cooper Silvana G. , Drumm Bernard T. , Feng Yumei
Published: March 2019

Activation of the brain renin-angiotensin system (RAS) is a pivotal step in the pathogenesis of hypertension. The paraventricular nucleus (PVN) of the hypothalamus is a critical part of the angiotensinergic sympatho-excitatory neuronal network involved in neural control of blood pressure and hypertension. However, the importance of the PVN (pro)renin receptor (PVN-PRR)—a key component of the brain RAS—in hypertension development has not been examined. In this study, we investigated the involvement and mechanisms of the PVN-PRR in DOCA-salt-induced hypertension, a mouse model of hypertension. Using nanoinjection of adeno-associated virus-mediated Cre recombinase expression to knock down the PRR specifically in the PVN, we report here that PVN-PRR knockdown attenuated the enhanced blood pressure and sympathetic tone associated with hypertension. Mechanistically, we found that PVN-PRR knockdown was associated with reduced activation of ERK (extracellular signal-regulated kinase)-1/2 in the PVN and rostral ventrolateral medulla during hypertension. In addition, using the genetically encoded Ca2+ biosensor GCaMP6 to monitor Ca2+-signaling events in the neurons of PVN brain slices, we identified a reduction in angiotensin II type 1 receptor-mediated Ca2+ activity as part of the mechanism by which PVN-PRR knockdown attenuates hypertension. Our study demonstrates an essential role of the PRR in PVN neurons in hypertension through regulation of ERK1/2 activation and angiotensin II type 1 receptor-mediated Ca2+ activity.

NEW & NOTEWORTHY PRR knockdown in PVN neurons attenuates the development of DOCA-salt hypertension and autonomic dysfunction through a decrease in ERK1/2 activation in the PVN and RVLM during hypertension. In addition, PRR knockdown reduced AT1aR expression and AT1R-mediated calcium activity during hypertension. Furthermore, we characterized the neuronal targeting specificity of AAV serotype 2 in the mouse PVN and validated the advantages of the genetically encoded calcium biosensor GCaMP6 in visualizing neuronal calcium activity in the PVN.
X-Ray Spectrographic Analysis of Nickel Containing Alloys with Varied Sample Forms
Authors: Davis C. Manning , Clark George R.
Published: March 2019

Techniques are presented whereby X-ray spectrographic analyses are carried out on alloys and metallurgical products which enter the Laboratory in the form of drillings, millings, or filings. The techniques described include direct analysis, with and without internal standards. Analysis of high temperature alloys without a aeries of chemically analysed standards by these techniques have greatly extended the usefulness of the X-ray spectrograph.
X-Ray Emission Spectrographic Analysis of Bastnaesite Rare Earths
Authors: Lytle Farrell W. , Botsford James I. , Heller Henry A.
Published: March 2019

An X-ray emission spectrographic method of analysis is presented for the determination, of rare earth elements in fractions obtained from bastnaesite ore. The method includes the determination of yttrium, thorium, lanthanum., and the rare earth elements in various complex mixtures. The analysis technique is based upon comparing the samples to synthetic standards approximating the composition of the samples. Working curves are plotted on an absolute intensity basis, with, no correction for background. Examples of working curves and the analyses of typical rare earth concentrates are included. The selection of spectral lines for the various sample matrices is discussed. A special technique is used for samples in which rapid hydration and carbonation occurred.

By analyzing synthetic samples of known composition, the accuracy of the method was determined. The error of analysis was about 3 per cent of the amount present in the range from 5 to 100 per cent and about 7 per cent in the 0.2 to 5 per cent range. A maximum of about 40 samples per day may be analyzed for 7 elements each. The advantages and disadvantages of the method are discussed.
Direct Assay for Molybdenum and Ruthenium in Uranium Alloys by X-Ray Emission Spectrometry
Authors: Flikkema D. S. , Schablaske R. V.
Published: March 2019

It has been found possible to determine quickly the concentrations of molybdenum and ruthenium in non-radioactive alloys representative of high burn-up reactor fuels by the method of X-ray emission spectrometry. Preliminary steps of chemical dissolution and separation are not required. The alloys, essentially ternaries of molybdenum and ruthenium with uranium, are being studied because they are considered to typify the alloys which will result from cycling uranium fuel elements through the sequence of fabrication, use and pyro.metallurgical processing.

The analytical procedure involves sampling of the ingot by slicing with a silicon carbide wheel at the plane of interest and reducing the surface to the flatness and finish obtained by a five-minute grinding and polishing operation. In the X-ray spectrograph the flat surface is examined for the intensities of its molybdenum and ruthenium K emission lines, with counting times of one to eight minutes. Calibration plots of intensity versus chemically determined weight per cent are established and used for subsequent sets of analyses.
Analysis of Diffusion Couples by X-Ray Absorption
Authors: Ogilvie Robert E.
Published: March 2019

When two metals are allowed to diffuse into one another, a diffusion aone is formed, the shape of which is determined by the relative diffusivities of the two elements, the time and temperature of the diffusion, and the number of phases existing in equilibrium at the diffusion temperature.

An X-ray absorption technique has been developed to analyze such concentration gradients. This involves the preparation of a thin section from a typical diffusion couple parallel to its axis. This is then scanned with a monochromatic X-ray beam and the transmitted X-rays are measured with a Gejger counter. The intensity of the transmitted beam is determined by the composition of the area in question and the absorption coefficients of the two elements.
Part I-Description and Application of Diffraction Method
Authors: Weissmann Sigmund
Published: March 2019

A method is described which combines optical microscopy with x-ray microscopy and diffraction analysis. The topographical relationship of the grains of a fine-grained material and the fine-structural details of their surface texture are disclosed by a special technique of reflection x-ray microscopy. The experimental observations made by this technique are being correlated to those made by optical microscopy. The individual grains are subsequently analyzed for their substructure characteristics by a photographic tracer technique and a method based on the principle of the double-crystal diffractometer. Quantitaive information is obtained concerning the lattice misalignment of the grains, the size of subgrains, disorientation angle between subgrains, lattice misalignment existing within the subgrains and the nature of low-angle boundaries. Application of the method to the analysis of inclusions and precipitates dispersed in a polycrystalline matrix is discussed.
Instrumentation for X-Ray Diffraction Studies of Highly Radioactive Samples
Authors: Scotti Vincent G. , Mueller James I. , Little John J.
Published: March 2019

With the advent of nuclear engineering, x-ray diffraction has become an important analytical tool in the study of radiation damage due to neutron and gamma-ray irradiation. The materials under study in this work have rdioactive levels up to 40 R/hr. at 17 centimeters combined β and γ. The activity of the various samples under study may be due to (n, γ) reactions or fission products or both.

Data are presented to illustrate the use of sample shielding, detector shielding pulse height discrimination and the combination of all three aids in an effort to attain the most favorable peak to background ratio.
Fluorescent X-Ray Analysis of Highly Radioactive Samples
Authors: Mueller James I. , Scotti Vincent G. , Little John J.
Published: March 2019

This paper describes the use of lead shielding and pulse height discrimination as aids in reducing the background counts due to radioactive samples. The samples under study in this work have radioactive levels up to 40 R/hr. at 17 centimeters combinedβ+γ.

Data are presented to illustrate the tiffectiveness of shielding and pulse height discrimination individually and combined.
An Application of the Mutual Standards Concept to X-Ray Fluorescence Spectroscopy: The Analysis of Meteoritic Sulphide Nodules for Eight Elements
Authors: Chodos Arthur A. , Nichiporuk Walter
Published: March 2019

The mutual standards concept has been applied to the X-ray fluorescence spectroscopic analysis of metcoritic Sulphide nodules for Fe, As, Co, Cr, Cu, Ni, V, and Zn. The technique is rapid and requires no addition of internal standards or binders.

On a sulphur free basis, concentrations range from 88-100% for Fe, up to 10% for Cr and Ni, up to 1% for Co, Cu and Zn, and up to 0.05% for As and V. Sensitivities vary from. 20 to 80 ppm on 100 mg. samples.

Analysis of a large number of chemically synthesized samples indicates accuracies comparable to chemical techniques employed in our laboratory.
X-Ray Emission Spectrographic Analysis of High-Purity Rare-Earth Oxides
Authors: Lytle Farrel W. , Heady Howard H.
Published: March 2019

Minor amounts of rare-earth elements (0.01 to 1.0%) in high-purity rare-earth oxides may be determined by a fluorescent X-ray procedure. The analysis of high-purity yttrium, cerium, praseodymium, neodymium, and samarium is described. Basic to the method is accurate determination of spectral line intensity above background. Sample and standard preparation, choice of analytical lines, and utilization of a helium path to increase X-ray intensities are discussed. Precision and accuracy were evaluated by analyzing samples of known composition. The average of five separate determinations showed an average error of about 10 per cent.
An X-Ray Camera for Precision Lattice Parameter Measurements
Authors: Franks A.
Published: March 2019

A back-reflection focusing camera has been constructed in which instrumental errors, including those due to uneven film shrinkage, have been eliminated or very much reduced. This has been achieved by employing metrological techniques both in construction and calibration, The temperature of the camera can be controlled to 0.05°C. The form of the specimen is such that horizontal and vertical divergence cause no line shift. The X-ray source is a demountable semimicrofocus tube with an adjustable focus. The radiation is monochromatized by a bent and ground quartz crystal.
A Highly Simplified Multielement Calibration System for Semiquantitative X-Ray
Spectrographic Analysis
Authors: Salmon Merlyn L.
Published: March 2019

Semiquantitative results are adequate for the satisfactory solution of many problems involving mineral analyses, andfluorescent X-ray spectrography is gaining more recognition as a satisfactory method for performance of these analyses.

Successful applications of the method, in various instances are discussed to demonstrate a system involving minimum s am - pie preparation and the use of instrumental factors in establishing multielement calibration curves.
Integrated X-Ray Diffraction Intensities from Single Crystals
Authors: Chessin Henry
Published: March 2019

The advantages and accuracy of counter equipment for the measurement of the intensity of scattered X-rays from small single crystals are discussed and illustrated. Several precautions necessary to obtain reliable intensity measurements are discussed. The equi-inclination method of inspecting all accessible reflections is treated in detail. The practicality of the stationary crystal method for determining integrated intensities, in principle the most accurate and rapid method, is demonstrated. Suggestions for improving the accuracy and speed of collecting data are made.
Determination of Relative Stability of Urea Complexes from X-Ray Powder Diffraction Data
Authors: Radell Jack , Connolly J.W.
Published: March 2019

Urea complexes consist of a channel made up of hydrogen-bonded urea host molecules into which a variety of guest molecules can fit to form a crystalline complex. The urea host can accommodate, one at a time, a variety of guests having the requisite size and shape. The stability of the resulting complex is a function of the properties of the guest molecule. A procedure has been devised which produces pure complex free of any uncomplexed urea or host molecules in solution. The insoluble crystalline complexes formed from the solution of urea and guest molecule in methanol established a dynamic equilibrium. When the crystals of complex are removed from the solution, dissociation to urea and guest occurs to an extent, depending upon the dissociation constant of the complex. If the dissociation constant, KD, is very low, undetectable quantities of uncomplexed urea form along with complex. If the dlissoclation constant is high, extensive amounts of urea form in the presence of complex. Characteristic interplanar spacing s are obtained for a urea complex irrespective of the guest molecule present. The pattern obtained for the hexagonal complex is completely different from the pattern obtained for tetragonal urea. X-ray examination of a homologous series of compounds gives, for each partially dissociated complex, spacings for both urea and complex. The relative intensities of urea and complex spacings permit the estimation of the stability of such a complex compared to that of other homologues.
Twenty Years of Progress in X-Ray Diffraction Techniques
Authors: Guinier Andre
Published: March 2019

Although no revolutionary advance has been achieved in the last two decades, X-ray diffraction is not to be considered as a quiescent field of physics. Actually many improvements, in theory as well as in experiment, slight by themselves but very numerous, have considerably increased the efficiency of techniques such as the determination of crystal structures, the analysis of crystalline phases, and the applications of X-rays to various problems of the physics of solids. Only the two last points will be dealt with here:

1.

Crystalline phase analysis. The development of a satisfactory atlas of powder patterns has been too slow, and the data are not yet complete and precise enough to permit a rational utilization of the modern diffractometers. A very interesting new approach is the systematic indexing of the powder patterns which would be possible with computers. In the near future, anyone should be able to analyze a powder at any temperature as an easy routine experiment.

2.

The study of lattice defects. X-ray techniques are now in competition with electron microscopy, the development of which has been very successful in recent years. Now we have a better understanding of the possibilities of both techniques. X-rays give better results to determine the statistics of an extended disorder even if it is slight (e.g., degrees of order in a solid solution), and the microscope is more powerful for the detection of large but rare defects (e.g., dislocations).