bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of pigeon pea leaves (Cajanus cajan) replacing alfalfa meal on growth performance, carcass trait, nutrient digestibility, antioxidant capacity and biochemical parameters of rabbits
Authors: Chen Yiye , Zhu Ni , Chen Xiaoyang , Liu Guangbin , Li Yaokun , Guo Yongqing , Deng Ming , Liu Dewu , Sun Baoli
Published: May 2019

A 30‐day experiment was performed to determine the effect of pigeon pea leaves (PPL) on growth performance, carcass trait, meat quality, nutrient digestibility, antioxidant capacity and biochemical parameters of growing rabbits. In a completely randomized design, PPL replaced alfalfa meal at the level of 0%, 10%, 20% and 30%, which were named PPL0 (control), PPL10, PPL20 and PML30 respectively. Two hundred New Zealand white rabbits at 6 weeks with similar weight (870.23 ± 15.98 g) were allocated to four dietary groups with five replicates containing 10 rabbits/per replicate (male). The results showed that: (a) PPL powder contained 24.26% crude protein, 4.34% crude fat, 17.86% crude fibre, 7.05% ash, 1.35% calcium, 0.28% phosphorus, 1.09% lysine and 0.20% methionine, and the chemical compositions are on DM basis; (b) the ratio of feed to gain of rabbits fed diet PPL10 was significantly better (p < 0.05) than those fed other three diets; (c) the content of longissimus dorsi (LD) moisture in the rabbits fed diets without PPL (control group) was 12% lower than that in the PPL30 diets (60.1 vs. 72.1; p < 0.05). In PPL10, PPL20 and PPL30 diets, the leg muscle (LM) b*(yellowness) value was 33%, 30% and 22.6% higher than the control group respectively. The rabbits fed diets PPL0 had lower (p < 0.05) LM crude protein and ash and higher (p < 0.05) crude fat of LD and LM as compared with those fed other diets; (d) crude protein and energy digestibility of PPL0 and PPL10 diets were significantly higher (p < 0.05) than PPL30 diets; and (e) serum glutathione peroxidase (GSH‐Px) activity of the rabbits fed PPL10 and PPL30 diets was significantly higher (p < 0.05) than that fed PPL20 diets. Liver total antioxidant capacity (T‐AOC) activity of the PPL30 groups was 1.3% higher (p < 0.05) than the PPL10 group. Additionally, the control group (PPL0) had the highest (p < 0.05) blood urea nitrogen (BUN), total cholesterol (TCHO) and low‐density lipoprotein cholesterol (LDLC) content compared with the groups supplemented with PPL. The PPL30 group had the highest (p < 0.05) triiodothyronine (T3) and tetraiodothyroxine (T4) value among the dietary groups.
In ovo injection of flavanone on bone quality characteristics, biochemical parameters and antioxidant enzyme status of blood in daily chicks
Authors: Ranjbar Zahra , Torki Mehran , Karimi Torshizi Amir Ali
Published: May 2019

In ovo injection (IOI) of Naringin (N), flavanone was examined on post‐hatch blood biochemical parameters, antioxidant status and bone characteristics. Fertile eggs (n = 700) were distributed in seven groups with 100 eggs. On 14th and 17.5th days of incubation, four groups were injected using 15 or 30 mg active ingredient levels of naringin/0.5 ml saline/egg, low and high level, into amnion sac. Controls include sham (injected normal saline, 0.5 ml/egg on day 14 and 17.5th) and un‐injected group. IOI of high naringin and saline on 14th day of incubation resulted in lower hatchability and then higher mortality in last week of embryonic life. On day hatch, high levels of injected groups more body weight compared to the control. Chick length was increased at high levels of naringin on day 17.5th compared to control and saline injected. Quality traits of bones were improved in naringin‐injected groups compared to control. IOI of naringin influenced thyroid hormones on 14th day of incubation. Naringin groups influenced the Alkaline phosphatase (ALP), Calcium (Ca), superoxide dismutase (SOD), blood biochemical and lipids. Totally, amniotic IOI of naringin in last days of developing embryo may be useful for hatched chick, development of leg long bone or effect on biochemical metabolites by levels of flavanone that it needs more research.
Mesoscale and microscale shock effects in the LL6 S4 chondrites Saint‐Séverin and Elbert: A tale of two breccias
Authors: Hugo Richard C. , Ruzicka Alex M. , Rubin Alan E.
Published: May 2019

Saint‐Séverin and Elbert, two LL6 chondrite breccias, were systematically studied to evaluate multiple deformation effects on spatial scales ranging from thin section (mesoscale) to micron‐submicron (microscale) using optical microscopy, electron backscatter diffraction (EBSD), and transmission electron microscopy (TEM). The different techniques provide consistent results but have complementary strengths, together providing a powerful approach to unravel even complex impact histories. Both meteorites have an S4 conventional shock stage, but interclast areas are more deformed, and clasts are more deformed in Elbert than in Saint‐Séverin. TEM and EBSD data provide compelling evidence that Saint‐Séverin experienced significant shock deformation while already hot, and cooled rapidly afterward, as a result of a major, possibly disruptive impact on the LL chondrite parent body ~4.4 Ga ago. In contrast, Elbert was shocked from a cold initial state but was heated significantly during shock, and cooled in a localized hot impact deposit on the LL asteroid. Both meteorites probably were shocked at least twice; data for Saint‐Séverin are best reconciled with a three‐impact model.
Improving the lives of millions through new double fortification of salt technology
Authors: Diosady Levente L. , Mannar M.G. Venkatesh , Krishnaswamy Kiruba
Published: May 2019

Micronutrient deficiencies (including iodine and iron deficiency) is a global health problem affecting one third of the world's population. Salt is an ideal carrier for food fortification as it is universally consumed at equal rates, independently of economic status, and it is industrially processed. Addressing iron and iodine deficiencies together is a challenge, due to interaction between iodine and iron, negating the effect of added iodine. This paper explains the development of an improved microencapsulation‐based technology to produce iron premix, which, when added to iodized salt, is stable and organoleptically indistinguishable. Ferrous fumarate was extruded, followed by cutting, sieving to achieve a size of 300–710 μm (salt grain size). Agglomerated extrudates were microencapsulated (5% hydroxypropyl methylcellulose and 5% soy stearin) to form iron premix. Microencapsulation ensures that the added micronutrients are stable without interaction or degradation. Double Fortified Salt is formed by blending iron premix with iodized salt (1:200 ratio). This technology was transferred to India for industrial scale‐up. The public distribution system was utilized to establish and monitor an efficient distribution network for DFS in a transparent manner. The scale‐up process was initially demonstrated in the state of Uttar Pradesh, following its success two more Indian states have started distribution of DFS. At present, the DFS with iron and iodine is reaching 60 million people in India. This important health intervention technology through food fortification has the potential to be scaled globally to ensure a world free from iron deficiency anemia.
Intraspecific divergence in floral‐tube length promotes asymmetric pollen movement and reproductive isolation
Authors: Minnaar Corneile , de Jager Marinus L. , Anderson Bruce
Published: May 2019

The causative link between phenotypic divergence and reproductive isolation is an important but poorly understood part of ecological speciation. We studied the effects of floral‐tube length variation on pollen placement/receipt positions and reproductive isolation.

In a population ofLapeirousia anceps(Iridaceae) with bimodal floral‐tube lengths, we labelled pollen of short‐ and long‐tubed flowers with different colour fluorescent nanoparticles (quantum dots). This enabled us to map pollen placement by long‐ and short‐tubed flowers on the only floral visitor, a long‐proboscid fly. Furthermore, it allowed us to quantify pollen movement within and between short‐ and long‐tubed flowers.

Short‐ and long‐tubed flowers placed pollen on different parts of the pollinator, and long‐tubed flowers placed more pollen per visit than short‐tubed flowers. This resulted in assortative pollen receipt (most pollen received comes from the same phenotype) and strong but asymmetric reproductive isolation, where short‐tubed plants are more reproductively isolated than long‐tubed plants.

These results suggest that floral‐tube length divergence can promote mechanical isolation in plants through divergence in pollen placement sites on pollinators. Consequently, in concert with other reproductive isolation mechanisms, selection for differences in floral‐tube length can play an important role in ecological speciation of plants.
A national study of nursing homes as learning environments according to undergraduate nursing student’s perspective
Authors: Gonella Silvia , Brugnolli Anna , Terzoni Stefano , Destrebecq Anne , Saiani Luisa , Zannini Lucia , Dimonte Valerio , Canzan Federica , Mansutti Irene , Palese Alvisa ,   the SVIAT TEAM
Published: May 2019

Background

Nursing students report care of the older people as an undesirable career pathway. Positive clinical placement experiences influence students’ attitudes and career intentions with respect to nursing home (NH) setting. The clinical environment's quality depends on meaningful learning opportunities, the relationship with the preceptors, and the pedagogical atmosphere as influenced by the staff–student interactions.

Aim

The aim of this study was to explore nursing students’ perceptions on their clinical learning experience and competence learned in the NH setting as compared to other clinical areas.

Methods

A secondary analysis was performed of an Italian national cross‐sectional study involving 9,607 nursing students attending 95 different three‐year bachelor laureate nursing programmes in 27 universities. A questionnaire exploring individual and nursing programme variables was devised. Moreover, students self‐reported the perceived quality of the clinical learning experience using the Clinical Learning Quality Evaluation Index tool and the degree of competence learned using a four‐point Likert‐type scale.

Results

Students in the NH setting scored the overall quality of the learning environment significantly higher (p = 0.046) compared to those experiencing other clinical settings, and they scored higher learning occasions (p = 0.002) and self‐directed learning opportunities (p = 0.018). No difference emerged in the perceived mean degree of competences learned at the end of the clinical rotation (p = 0.271).

Conclusion

Nursing students perceive the NH setting to be a good quality learning environment with valuable learning opportunities and self‐directed learning opportunities compared to other settings. The nursing home setting provides opportunities to acquire clinical competences comparable to the ones in other clinical settings such as hospital units.

Implications for practice

Nursing home settings should be considered by all nursing programmes as a learning environment particularly worthy for students at different levels of their education.
Natural rubber biosynthesis in plants, the rubber transferase complex, and metabolic engineering progress and prospects
Authors: Cherian Sam , Ryu Stephen Beungtae , Cornish Katrina
Published: May 2019

Natural rubber (NR) is a nonfungible and valuable biopolymer, used to manufacture ~50 000 rubber products, including tires and medical gloves. Current production of NR is derived entirely from the para rubber tree (Hevea brasiliensis). The increasing demand for NR, coupled with limitations and vulnerability of H. brasiliensis production systems, has induced increasing interest among scientists and companies in potential alternative NR crops. Genetic/metabolic pathway engineering approaches, to generate NR‐enriched genotypes of alternative NR plants, are of great importance. However, although our knowledge of rubber biochemistry has significantly advanced, our current understanding of NR biosynthesis, the biosynthetic machinery and the molecular mechanisms involved remains incomplete. Two spatially separated metabolic pathways provide precursors for NR biosynthesis in plants and their genes and enzymes/complexes are quite well understood. In contrast, understanding of the proteins and genes involved in the final step(s)—the synthesis of the high molecular weight rubber polymer itself—is only now beginning to emerge. In this review, we provide a critical evaluation of recent research developments in NR biosynthesis, in vitro reconstitution, and the genetic and metabolic pathway engineering advances intended to improve NR content in plants, including H. brasiliensis, two other prospective alternative rubber crops, namely the rubber dandelion and guayule, and model species, such as lettuce. We describe a new model of the rubber transferase complex, which integrates these developments. In addition, we highlight the current challenges in NR biosynthesis research and future perspectives on metabolic pathway engineering of NR to speed alternative rubber crop commercial development.
Strawberry tonoplast transporter, FaVPT1, controls phosphate accumulation and fruit quality
Authors: Huang Yun , Xu Peng‐Hao , Hou Bing‐Zhu , Shen Yuan‐Yue
Published: May 2019

Phosphorus (P) is essential for plant growth and development, and the vacuole is an important organelle for phosphate storage. However, the tonoplast phosphate transporter in fleshy fruits remains unknown. In this study, based on the strawberry (Fragaria × ananassa) fruit transcriptome data, a tonoplast‐localized vacuolar phosphate transporter with SPX and major facilitator superfamily domains, FaVPT1, was identified. FaVPT1 expression was highest in the fruits and could be induced by sucrose. Using transient transgenic systems in strawberry fruit, the downregulation and upregulation of FaVPT1 inhibited and promoted ripening, respectively, and affected phosphate contents, fruit firmness, sugar and anthocyanin contents, and ripening‐related gene transcription. FaVPT1 could rescue Pi absorption in both yeast and the Arabidopsis atvpt1 mutant, confirming the similar function of FaVPT1 and AtVPT1, a previously identified tonoplast phosphate transporter in Arabidopsis. The Escherichia coli–expressed SPX domain of FaVPT1 could strongly bind to InsP6 with a Kd of 3.5 μM. The results demonstrate that FaVPT1 is a tonoplast phosphate transporter and regulates strawberry fruit ripening and quality, to a large extent, via sucrose.
Hikikomori : Multidimensional understanding, assessment, and future international perspectives
Authors: Kato Takahiro A. , Kanba Shigenobu , Teo Alan R.
Published: May 2019

Hikikomori, a severe form of social withdrawal, has long been observed in Japan mainly among youth and adolescents since around the 1970s, and has been especially highlighted since the late 1990s. Moreover, hikikomori‐like cases have recently been reported in many other countries. Hikikomori negatively influences not only the individual's mental health and social participation, but also wider education and workforce stability, and as such is a novel urgent global issue. In this review, we introduce the history, definition, diagnostic evaluation, and interventions for hikikomori and also the international prevalence of hikikomori outside Japan. We propose a hypothesis regarding the globalization of hikikomori based on domestic and international perspectives. In addition, we introduce our latest assessment system for hikikomori (including the latest version of the ‘proposed diagnostic criteria of hikikomori for the future DSM/ICD diagnostic systems’) and propose therapeutic strategies, including family approaches and individualized therapies. Finally, we present future challenges that may lead to solutions for an internationalized hikikomori.
A Viewpoint on Research for Social Business Entrepreneurship
Authors: Desai Sameeksha , Tyler John E.
Published: May 2019

This Viewpoint essay outlines key considerations for research on entrepreneurship, and for social business entrepreneurship specifically, considering the wide range of forms and essentially heterogeneous nature of this broad set of businesses. Themes related to practical research and key questions are outlined, along with considerations for researchers as the social business entrepreneurship space continues to evolve.
Over the ROC methodology: Productivity, economic size and firms’ export thresholds
Authors: Costa Stefano , Sallusti Federico , Vicarelli Claudio , Zurlo Davide
Published: May 2019

We identify the minimum combinations of productivity and “economic size” that Italian manufacturing firms need to achieve in order to access international markets. These “export thresholds” are estimated by applying, for the first time in economics, the ROC (receiver operating characteristics) methodology. In this way, we detect a model‐based (rather than a subjectively determined) cut‐off that allows to identify exporters and nonexporters and provides a measure of each firm’s distance from the export threshold. This methodology also paves the way to investigate other determinants of thresholds, thus helping to design more effective policy interventions to reduce barriers to trade.
Narrowest-Over-Threshold Detection of Multiple Change Points and Change-Point-Like Features
Authors: Baranowski Rafal , Chen Yining , Fryzlewicz Piotr
Published: May 2019

We propose a new, generic and flexible methodology for non-parametric function estimation, in which we first estimate the number and locations of any features that may be present in the function and then estimate the function parametrically between each pair of neighbouring detected features. Examples of features handled by our methodology include change points in the piecewise constant signal model, kinks in the piecewise linear signal model and other similar irregularities, which we also refer to as generalized change points. Our methodology works with only minor modifications across a range of generalized change point scenarios, and we achieve such a high degree of generality by proposing and using a new multiple generalized change point detection device, termed narrowest-over-threshold (NOT) detection. The key ingredient of the NOT method is its focus on the smallest local sections of the data on which the existence of a feature is suspected. For selected scenarios, we show the consistency and near optimality of the NOT algorithm in detecting the number and locations of generalized change points. The NOT estimators are easy to implement and rapid to compute. Importantly, the NOT approach is easy to extend by the user to tailor to their own needs. Our methodology is implemented in the R package not.
On how the immune system preferentially interacts with antigen‐specific molecules bound to antigen over unbound molecules, with emphasis on B cell receptor signalling
Authors: Bretscher Peter A. , Al‐Yassin Ghassan A.
Published: May 2019

Antigen‐specific molecules of the immune system, namely antibodies, the membrane immunoglobulins (mIgs) of B cells and T cell receptors (TcRs), can all signal their interaction with antigen. There are different mechanisms by which this signalling could occur. These mechanisms can be divided into two general categories: allosteric and non‐allosteric. In allosteric mechanisms, the monovalent binding of the antigen to the receptor triggers a conformational change at the binding site that is propagated to an invariant part of the receptor, a change recognized by a sensing unit. We argue allosteric mechanisms are implausible. Non‐allosteric mechanisms depend on steric effects due to the antigen's size and/or multivalency. We consider two non‐allosteric mechanisms by which the mIg of B cells has been envisaged to signal its interaction with antigen: the popular cross‐linking model and the dissociation activation model. We argue, on the basis of both experimental observations and physiological considerations, that the dissociation activation model, developed by Reth and his colleagues, is uniquely plausible.
Phytoglobins in the nuclei, cytoplasm and chloroplasts modulate nitric oxide signaling and interact with abscisic acid
Authors: Rubio Maria C. , Calvo‐Begueria Laura , Díaz‐Mendoza Mercedes , Elhiti Mohamed , Moore Marten , Matamoros Manuel A. , James Euan K. , Díaz Isabel , Pérez‐Rontomé Carmen , Villar Irene , Sein‐Echaluce Violeta C. , Hebelstrup Kim H. , Dietz Karl‐Josef , Becana Manuel
Published: May 2019

Symbiotic hemoglobins provide O2 to N2‐fixing bacteria within legume nodules, but the functions of non‐symbiotic hemoglobins or phytoglobins (Glbs) are much less defined. Immunolabeling combined with confocal microscopy of the Glbs tagged at the C‐terminus with green fluorescent protein was used to determine their subcellular localizations in Arabidopsis and Lotus japonicus. Recombinant proteins were used to examine nitric oxide (NO) scavenging in vitro and transgenic plants to show S‐nitrosylation and other in vivo interactions with NO and abscisic acid (ABA) responses. We found that Glbs occur in the nuclei, chloroplasts and amyloplasts of both model plants, and also in the cytoplasm of Arabidopsis cells. The proteins show similar NO dioxygenase activities in vitro, are nitrosylated in Cys residues in vivo, and scavenge NO in the stomatal cells. The Cys/Ser mutation does not affect NO dioxygenase activity, and S‐nitrosylation does not significantly consume NO. We demonstrate an interaction between Glbs and ABA on several grounds: Glb1 and Glb2 scavenge NO produced in stomatal guard cells following ABA supply; plants overexpressing Glb1 show higher constitutive expression of the ABA responsive genes Responsive to ABA (RAB18), Responsive to Dehydration (RD29A) and Highly ABA‐Induced 2 (HAI2), and are more tolerant to dehydration; and ABA strongly upregulates class 1 Glbs. We conclude that Glbs modulate NO and interact with ABA in crucial physiological processes such as the plant's response to dessication.
Chloride as a macronutrient increases water‐use efficiency by anatomically driven reduced stomatal conductance and increased mesophyll diffusion to CO2
Authors: Franco‐Navarro Juan D. , Rosales Miguel A. , Cubero‐Font Paloma , Calvo Purificación , Álvarez Rosario , Diaz‐Espejo Antonio , Colmenero‐Flores José M.
Published: May 2019

Chloride (Cl−) has been recently described as a beneficial macronutrient, playing specific roles in promoting plant growth and water‐use efficiency (WUE). However, it is still unclear how Cl− could be beneficial, especially in comparison with nitrate (NO3−), an essential source of nitrogen that shares with Cl− similar physical and osmotic properties, as well as common transport mechanisms. In tobacco plants, macronutrient levels of Cl− specifically reduce stomatal conductance (gs) without a concomitant reduction in the net photosynthesis rate (AN). As stomata‐mediated water loss through transpiration is inherent in the need of C3 plants to capture CO2, simultaneous increase in photosynthesis and WUE is of great relevance to achieve a sustainable increase in C3 crop productivity. Our results showed that Cl−‐mediated stimulation of larger leaf cells leads to a reduction in stomatal density, which in turn reduces gs and water consumption. Conversely, Cl− improves mesophyll diffusion conductance to CO2 (gm) and photosynthetic performance due to a higher surface area of chloroplasts exposed to the intercellular airspace of mesophyll cells, possibly as a consequence of the stimulation of chloroplast biogenesis. A key finding of this study is the simultaneous improvement of AN and WUE due to macronutrient Cl− nutrition. This work identifies relevant and specific functions in which Cl− participates as a beneficial macronutrient for higher plants, uncovering a sustainable approach to improve crop yield.
The Arabidopsis non‐host defence‐associated coumarin scopoletin protects soybean from Asian soybean rust
Authors: Beyer Sebastian F. , Beesley Alexander , Rohmann Philipp F.W. , Schultheiss Holger , Conrath Uwe , Langenbach Caspar J.G.
Published: May 2019

The fungus Phakopsora pachyrhizi (Pp) causes Asian soybean rust (SBR) disease which provokes tremendous losses in global soybean production. Pp is mainly controlled with synthetic fungicides to which the fungus swiftly develops fungicide resistance. To substitute or complement synthetic fungicides in Asian soybean rust control, we aimed to identify antifungal metabolites in Arabidopsis which is not a host for Pp. Comparative transcriptional and metabolic profiling of the Pp‐inoculated Arabidopsis non‐host and the soybean host revealed induction of phenylpropanoid metabolism‐associated genes in both species but activation of scopoletin biosynthesis only in the resistant non‐host. Scopoletin is a coumarin and an antioxidant. In vitro experiments disclosed fungistatic activity of scopoletin against Pp, associated with reduced accumulation of reactive oxygen species (ROS) in fungal pre‐infection structures. Non‐antioxidant and antioxidant molecules including coumarins with a similar structure to scopoletin were inactive or much less effective at inhibiting fungal accumulation of ROS and germination of Pp spores. When sprayed onto Arabidopsis leaves, scopoletin also suppressed the formation of Pp pre‐infection structures and penetration of the plant. However, scopoletin neither directly activated defence nor did it prime Arabidopsis for enhanced defence, therefore emphasizing fungistatic activity as the exclusive mode of action of scopoletin against Pp. Because scopletin also protected soybean from Pp infection, the coumarin may serve as a natural fungicide or as a lead for the development of near‐to‐nature fungicides against Asian soybean rust.
Wear Performance Evaluation of Minimum Quantity Lubrication With Exfoliated Graphite Nanoplatelets in Turning Titanium Alloy
Authors: Nguyen Dinh , Lee Phi-Ho , Guo Yang , Park Kyung-Hee , Kwon Patrick
Published: May 2019

This paper evaluates the performances of dry, minimum quantity lubrication (MQL), and MQL with nanofluid conditions in turning of the most common titanium (Ti) alloy, Ti-6Al-4 V, in a solution treated and aged (STA) microstructure. In particular, the nanofluid evaluated here is vegetable (rapeseed) oil mixed with small concentrations of exfoliated graphite nanoplatelets (xGnPs). This paper focuses on turning process that imposes a challenging condition to apply the oil or nanofluid droplets directly onto the tribological surfaces of a cutting tool due to the uninterrupted engagement between tool and work material during cutting. A series of turning experiments was conducted with uncoated carbide inserts, while measuring the cutting forces with a dynamometer under the dry, MQL and MQL with nanofluid conditions supplying oil droplets externally from our MQL device. The inserts are retrieved intermittently to measure the progress of flank and crater wear using a confocal microscopy. This preliminary experimental result shows that MQL and in particular MQL with the nanofluid significantly improve the machinability of Ti alloys even in turning process. However, to attain the best performance, the MQL conditions such as nozzle orientation and the concentration of xGnP must be optimized.
An Efficient Numerical Model of Elastohydrodynamic Lubrication for Transversely Isotropic Materials
Authors: Wang Zhanjiang , Zhang Yinxian
Published: May 2019

An elastohydrodynamic lubrication model for a rigid ball in contact with a transversely isotropic half-space is constructed. Reynolds equation, film thickness equation, and load balance equation are solved using the finite difference method, where the surface vertical displacement or deformation of transversely isotropic half-space is considered through the film thickness equation. The numerical methods are verified by comparing the displacements and stresses with those from Hertzian analytical solutions. Furthermore, the effects of elastic moduli, entertainment velocities, and lubricants on fluid pressure, film thickness, and von Mises stress are analyzed and discussed under a constant load. Finally, the modified Hamrock–Dowson equations for transversely isotropic materials to calculate central film thickness and minimum film thickness are proposed and validated.
Effect of Heat Treatment on Tribological Properties of Ni-B Coatings on Low Carbon Steel: Wear Maps and Wear Mechanisms
Authors: Arias Sandra , Castaño Juan G. , Correa Esteban , Echeverría Félix , Gómez Maryory
Published: May 2019

Among the alternatives for using low-carbon steel in parts with heavy wear, as gears and bearing surfaces, Ni-B electroless coatings deposited on these steels are considered due to their wear resistance. Wear maps, elaborated from friction or wear results found for different evaluated conditions, are a very useful tool for the selection of materials based on tribological properties. However, wear maps for electroless Ni-B coatings are very scarce. In this work, dry sliding wear tests with different loads and sliding velocities were performed on Ni-B electroless coatings applied on AISI/SAE 1018 steel, with and without heat treatment at 450 °C for 1 h, with the aim of determining the effect of the heat treatment on the friction coefficients and wear rates. Contour and profile maps, and finally friction and wear maps, were constructed for each of the coatings evaluated. The coating properties before and after the heat treatment were studied by means of scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), scratch tests, nanoindentation, and differential scanning calorimetry (DSC). Sliding wear tracks were studied using SEM, energy-dispersive spectroscopy (EDS), and micro-Raman spectroscopy. Good agreement between experimental and predicted values was found in friction and wear maps. Wear mechanisms change from flattening in less severe conditions to abrasion in more severe conditions, besides spalling and adhesive wear in untreated coatings. Moreover, abrasive wear is lower in heat-treated coating than in untreated coating.
Influence of Micro-Lobed Burner on the Non-Premixed Combustion of Methane and Oxygen
Authors: Xie Yi , Yi Chuan-li
Published: May 2019

Non-premixed combustion was implemented in a micro-lobed combustion system, and its influence on combustion was studied using both experiments and simulations. The results show that a micro-lobed burner produces streamwise vortices with intensities that increase with the equivalence ratio of methane to oxygen (Φ). Due to the streamwise vortices and the increment of the contact area between methane and oxygen, the gasses mix well in the micro-lobed burner, giving it a larger OH mass fraction and higher temperatures than the micro-splitter burner. Moreover, the equivalence ratio greatly influences the combustion enhancement from the micro-lobed burner, especially near the burner exit. The maximum temperature difference between the two micro-burners at the Z/D = 0.01 cross section is 171 K, when Φ is 0.6. However, when the mixing enhancement caused by the streamwise vortices disappears, Φ has little influence on the combustion temperature of the micro-lobed burner, especially when Φ ≥ 1. In this case, the maximum temperature variation between the micro-lobed burner and micro-splitter burner remains nearly constant.
Development of Bolted Flange Design Tool Based on Artificial Neural Network
Authors: Yıldırım Alper , Akay Ahmet Arda , Gülaşık Hasan , Çoker Demirkan , Gürses Ercan , Kayran Altan
Published: May 2019

Finite element analysis (FEA) of bolted flange connections is the common methodology for the analysis of bolted flange connections. However, it requires high computational power for model preparation and nonlinear analysis due to contact definitions used between the mating parts. Design of an optimum bolted flange connection requires many costly finite element analyses to be performed to decide on the optimum bolt configuration and minimum flange and casing thicknesses. In this study, very fast responding and accurate artificial neural network-based bolted flange design tool is developed. Artificial neural network is established using the database which is generated by the results of more than 10,000 nonlinear finite element analyses of the bolted flange connection of a typical aircraft engine. The FEA database is created by taking permutations of the parametric geometric design variables of the bolted flange connection and input load parameters. In order to decrease the number of FEA points, the significance of each design variable is evaluated by performing a parameter correlation study beforehand, and the number of design points between the lower and upper and bounds of the design variables is decided accordingly. The prediction of the artificial neural network based design tool is then compared with the FEA results. The results show excellent agreement between the artificial neural network-based design tool and the nonlinear FEA results within the training limits of the artificial neural network.
Elephant’s Trunk Robot: An Extremely Versatile Under-Actuated Continuum Robot Driven by a Single Motor
Authors: Liu Yuwang , Ge Zhuang , Yang Shangkui , Walker Ian D. , Ju Zhaojie
Published: May 2019

Continuous-bodied “trunk and tentacle” robots have increased self-adaptability and obstacle avoidance capabilities, compared with traditional, discrete-jointed, robots with large rigid links. In particular, continuous-bodied robots have obvious advantages in grasping objects across a wide range of external dimensions. Not only can they grasp objects using end effectors like traditional robots, but their bodies can also be regarded as a gripping device, and large objects with respect to the robot’s scale can be captured by the entire structure of the robots themselves. Existing trunk-like robots have distributed multidrive actuation and are often manufactured using soft materials, which leads to a complex actuator system that also limits their potential applications in dangerous and extreme environments. This paper introduces a new type of elephant’s trunk robot with very few driving constraints. The robot consists of a series of novel underactuated linkage units. With a single-motor drive, the robot can achieve stable grasping of objects of different shapes and sizes. The proposed robot simplifies the requirements of the sensing and control systems during the operation process and has the advantage of accomplishing the capture task without determining the exact shape and position of the target object. It is especially suitable for operations such as non-cooperative target capture in extremely dangerous environments, including those in outer space. Based on theoretical analysis and model design, a trunk robot prototype was developed, and a comprehensive experimental study of the bending/extension and grasping operation functions was conducted to verify the validity of the proposed robot design.
Active Control of Nonlinear Transient Vibration of Laminated Composite Beams Using Triangular SCLD Treatment With Fractional Order Derivative Viscoelastic Model
Authors: Sahoo S. R. , Ray M. C.
Published: May 2019

This paper is concerned with the analysis of the effectiveness of triangular shaped smart constrained layer damping (SCLD) treatment in attenuating geometrically nonlinear transient vibrations of laminated composite beams. The SCLD treatment is comprised of an advanced vertically reinforced 1–3 piezoelectric composite (PZC) as the constraining layer and an isotropic viscoelastic layer as the constrained layer, which is modeled using a two-dimensional fractional order derivative (FOD) model with Grünwald definition of the FODs. A nonlinear meshfree model of the smart composite beam is developed for analyzing its nonlinear transient response within the framework of a layerwise shear and normal deformation theory considering von Kármán type geometric nonlinearity. Cantilever type composite beams having different lamination sequences integrated with regular rectangular/triangular type of SCLD treatments are considered for presenting the numerical results. For comparison purpose, a geometrical constraint has been imposed such that both the rectangular and triangular shaped SCLD treatments will cover the equal area on the top surface of the beam. The numerical analyses demonstrate the effectiveness of the triangular shaped SCLD patches over the rectangular SCLD treatment in controlling the nonlinear vibration of laminated composite beams. The two-dimensional FOD model of the viscoelastic material has been efficiently implemented for the active damping analysis of smart composite beam.
Magnetic Resonance Imaging Based Flow Field and Lagrangian Particle Tracking From a Left Ventricular Assist Device
Authors: Amili Omid , MacIver Robroy , Coletti Filippo
Published: May 2019

This study explores the optimal left ventricular assist device (LVAD) cannula outflow configuration in a patient-specific replica of the aorta. The volumetric velocity field is measured using phase-contrast magnetic resonance imaging (PC-MRI) under a physiologically relevant steady flow. The effect of the LVAD outflow graft insertion site and anastomosis angle on the transport of embolic particles to cranial vessels is studied by solving the particle equation of motion for spheres in the range of 0.1–1.0 mm using the measured three-dimensional (3D) velocity field. Results show that for a given aorta anatomy, it is possible to design the cannula graft location and terminal curvature so that the probability of embolic transport to the cranial vessels is significantly minimized. This is particularly important since the complex flow pattern in each cannula case affects the embolic trajectories differently, and hence the common assumption that particles distribute by the volumetric flow division does not hold.
Investigation of the Observed Rupture Lines in Abdominal Aortic Aneurysms Using Crack Propagation Simulations
Authors: Attarian S. , Xiao S. , Chung T. C. , da Silva E. S. , Raghavan M. L.
Published: May 2019

The objective of the study is to use crack propagation simulation to study the rupture site characteristics in ruptured abdominal aortic aneurysms (AAA). In a study population of four ruptured AAA harvested whole from cadavers, the rupture lines were precisely documented. The wall properties such as thickness and material parameters were experimentally determined. Using subject-specific three-dimensional (3D) geometry and a finite elastic isotropic material model with subject-specific parameters, crack propagation simulations were conducted based on basic fracture mechanics principles to investigate if and how localized weak spots may have led to the rupture lines observed upon harvest of ruptured AAA. When an initial crack was imposed at the site of peak wall stress, the propagated path did not match the observed rupture line. This indicates that in this study population, the peak wall stress was unlikely to have caused the observed rupture. When cracks were initiated at random locations in the AAA along random orientations and for random initial lengths, the orientation of the resulting propagated rupture line was always longitudinal. This suggests that the AAA morphology predisposes the AAA to rupture longitudinally, which is consistent with observations. And finally, it was found that, in this study population, rupture may have initiated at short segments of less than 1 cm length that then propagated to the observed rupture lines. This finding provides some guidance for the spatial resolution (approx. 1 cm) of weak spots to investigate for in AAA during ex vivo experimental and in vivo elastography studies. The small study population and lack of a reliable failure model for AAA tissue make these findings preliminary.
The genus Uroseius Berlese (Acari: Mesostigmata: Uropodina: Trachytidae) in the Iberian Peninsula with description of a new species associated with animal remains
Authors: Moraza Maria L. , Pérez-Martínez Sandra
Published: May 2019

Description of a new species of Uroseius Berlese based on deutonymph and female specimens from northern Spain is presented. Observations of some cuticular organs on idiosoma and legs are described for the first time for the genus. An attempt to notate idiosomal setae as in Gamasina mesostigmatid mites is made based on complete dorsal chaetome of larval and pronymphal instars of Uroseius and Apionoseius Berlese species. Uroseius acuminatus (C.L. Koch) is a new record for the Iberian Peninsula. General morphological and biological aspects of Uroseius are presented. A tentative key, provided for separation of the 15 deutonymphs and nine adult females of the world species of Uroseius, is given.
Expectations about the source of a speaker's accent affect accent adaptation
Authors: Vaughn Charlotte R.
Published: May 2019

When encountering speakers whose accents differ from the listener's own, listeners initially show a processing cost, but that cost can be attenuated after short term exposure. The extent to which processing foreign accents (L2-accents) and within-language accents (L1-accents) is similar is still an open question. This study considers whether listeners' expectations about the source of a speaker's accent—whether the speaker is purported to be an L1 or an L2 speaker—affect intelligibility. Prior work has indirectly manipulated expectations about a speaker's accent through photographs, but the present study primes listeners with a description of the speaker's accent itself. In experiment 1, native English listeners transcribed Spanish-accented English sentences in noise under three different conditions (speaker's accent: monolingual L1 Latinx English, L1-Spanish/L2-English, no information given). Results indicate that, by the end of the experiment, listeners given some information about the accent outperformed listeners given no information, and listeners told the speaker was L1-accented outperformed listeners told to expect L2-accented speech. Findings are interpreted in terms of listeners' expectations about task difficulty, and a follow-up experiment (experiment 2) found that priming listeners to expect that their ability to understand L2-accented speech can improve does in fact improve intelligibility.
The effects of amplitude and duration on the perception of English statements vs questions for native English and Chinese listeners
Authors: Feng Jie , Tao Sha , Wu Xinchun , Alsbury Katherine , Liu Chang
Published: May 2019

The current study investigated whether amplitude and duration cues were salient for signaling English questions versus statements for native Mandarin Chinese listeners. The F0 contours of the final word were manipulated continuously from falling to rising patterns with the amplitude or duration varied. English-native and Chinese-native (EN and CN) listeners identified whether they heard a statement or a question. Results showed that the performance of EN listeners was influenced by the change of amplitude and duration in question-statement identification, while CN listeners' performance was not, suggesting possible differences of cue weighting between the two groups in distinguishing English sentence types.
Wave number–spiral acoustic tweezers for dynamic and reconfigurable manipulation of particles and cells
Authors: Tian Zhenhua , Yang Shujie , Huang Po-Hsun , Wang Zeyu , Zhang Peiran , Gu Yuyang , Bachman Hunter , Chen Chuyi , Wu Mengxi , Xie Yangbo , Huang Tony Jun
Published: May 2019

Acoustic tweezers with frequency multiplexing enable dynamic manipulation of micro-objects using dual-channel excitation.
Ultra-compact broadband polarization diversity orbital angular momentum generator with 3.6 × 3.6 μm
2
footprint
Authors: Zhou Nan , Zheng Shuang , Cao Xiaoping , Zhao Yifan , Gao Shengqian , Zhu Yuntao , He Mingbo , Cai Xinlun , Wang Jian
Published: May 2019

We demonstrate an ultra-compact broadband polarization diversity orbital angular momentum generator on a silicon platform
Strain tolerance of two-dimensional crystal growth on curved surfaces
Authors: Wang Kai , Puretzky Alexander A. , Hu Zhili , Srijanto Bernadeta R. , Li Xufan , Gupta Nitant , Yu Henry , Tian Mengkun , Mahjouri-Samani Masoud , Gao Xiang , Oyedele Akinola , Rouleau Christopher M. , Eres Gyula , Yakobson Boris I. , Yoon Mina , Xiao Kai , Geohegan David B.
Published: May 2019

2D crystals of WS
2
stretch as they grow over curved surfaces, allowing strain engineering of their optoelectronic properties.
Direct link between mechanical stability in gels and percolation of isostatic particles
Authors: Tsurusawa Hideyo , Leocmach Mathieu , Russo John , Tanaka Hajime
Published: May 2019

Mechanical stability of colloidal gels emerges from the isotropic percolation of locally rigid isostatic structures.
Two-dimensional hybrid perovskites sustaining strong polariton interactions at room temperature
Authors: Fieramosca A. , Polimeno L. , Ardizzone V. , De Marco L. , Pugliese M. , Maiorano V. , De Giorgi M. , Dominici L. , Gigli G. , Gerace D. , Ballarini D. , Sanvitto D.
Published: May 2019

Large single-crystal flakes of 2D perovskite are able to sustain strong polariton nonlinearities at room temperature.
Peripheral lymph nodes contain migratory and resident innate lymphoid cell populations
Authors: Dutton Emma E. , Gajdasik Dominika W. , Willis Claire , Fiancette Remi , Bishop Emma L. , Camelo Ana , Sleeman Matthew A. , Coccia Margherita , Didierlaurent Arnaud M. , Tomura Michio , Pilataxi Fernanda , Morehouse Christopher A. , Carlesso Gianluca , Withers David R.
Published: May 2019

Innate lymphoid cells recirculate through peripheral lymph nodes and contribute to early IFN-γ production after immunization.
NF-κB RelA Is Required for Hepatoprotection during Pneumonia and Sepsis
Authors: Kim Yuri , Allen Eri , Baird Lillia A. , Symer Elise M. , Korkmaz Filiz T. , Na Elim , Odom Christine V. , Jones Matthew R. , Mizgerd Joseph P. , Traber Katrina E. , Quinton Lee J.
Published: May 2019

Pneumonia and sepsis are distinct but integrally linked public health concerns. The hepatic acute-phase response (APR), which is largely dependent on transcription factors NF-κB RelA and STAT3, is a hallmark of these pathologies and other injurious conditions. Inactivation of the APR can promote liver injury, a frequently observed organ dysfunction during sepsis. However, whether or how the acute-phase changes promote liver tissue resilience during infections is unclear.
Miliary pattern on chest imaging as a presentation of EGFR-negative primary lung adenocarcinoma
Authors: Hoffman Seth A , Manski Scott , Deepak Janaki
Published: May 2019

A 64-year-old African American man, with a history of prostate adenocarcinoma treated in 2009 and a greater than 50-pack-year tobacco smoking history, presented with 2–3 weeks of non-productive cough, frontal headache and generalised myalgias and arthralgias. CT was positive for diffuse, miliary opacities in bilateral lung fields. He was diagnosed with stage four lung adenocarcinoma, negative for epidermal growth factor receptor (EGFR) gene mutation. The patient was unable to tolerate therapy and passed away approximately 4 months after his diagnosis. Previous case reports and research have suggested an association between EGFR gene mutation and miliary patterned lung metastases in non-small cell lung cancer. This case suggests that the mechanism by which miliary patterned metastases occur is more complex than purely mutation of the EGFR gene. Further study may elucidate novel molecular targets for treatment, especially in patients with rapidly progressive disease such as the patient we describe.