bluuebunny/crossref_metadata_2025 huggingface dataset:
The large‐scale drivers of population declines in a long‐distance migratory shorebird
Authors: Murray Nicholas J. , Marra Peter P. , Fuller Richard A. , Clemens Robert S. , Dhanjal‐Adams Kiran , Gosbell Ken B. , Hassell Chris J. , Iwamura Takuya , Melville David , Minton Clive D. T. , Riegen Adrian C. , Rogers Danny I. , Woehler Eric J. , Studds Colin E.
Published: September 2017

Migratory species can travel tens of thousands of kilometers each year, spending different parts of their annual cycle in geographically distinct locations. Understanding the drivers of population change is vital for conserving migratory species, yet the challenge of collecting data over entire geographic ranges has hindered attempts to identify the processes leading to observed population changes. Here, we use remotely sensed environmental data and bird count data to investigate the factors driving variability in abundance in two subspecies of a long‐distance migratory shorebird, the bar‐tailed godwit Limosa lapponica. We compiled a spatially and temporally explicit dataset of three environmental variables to identify the conditions experienced by each subspecies in each stage of their annual cycle (breeding, non‐breeding and staging). We used a Bayesian N‐mixture model to analyze 18 years of monthly count data from 21 sites across Australia and New Zealand in relation to the remote sensing data. We found that the abundance of one subspecies L. l. menzbieri in their non‐breeding range was related to climate conditions in breeding grounds, and detected sustained population declines between 1995 and 2012 in both subspecies (L. l. menzbieri, –6.7% and L. l. baueri, –2.1% year–1). To investigate the possible causes of the declines, we quantified changes in habitat extent at 22 migratory staging sites in the Yellow Sea, East Asia, over a 25‐year period and found –1.7% and –1.2% year–1 loss of habitat at staging sites used by L. l. menzbieri and L. l baueri, respectively. Our results highlight the need to identify environmental and anthropogenic drivers of population change across all stages of migration to allow the formulation of effective conservation strategies across entire migratory ranges.
The curse of low expectations
Authors: Battaglia Marianna , Lebedinski Lara
Published: September 2017

We examine how a remedial education programme for primary school‐age children affects parental expectations about their children's future. Using original survey data we collected in Serbia, we investigate whether expectations on labour market prospects and educational attainment change as a consequence of exposure to the Roma Teaching Assistant programme. Our results show that parents of pupils in treated schools expect higher returns to education for their children and are more likely to expect them to achieve a secondary level of education. We also investigate the possible mechanisms in place due to the characteristics of the programme: remedial education and role model.
Cocoa agroforestry is less resilient to sub‐optimal and extreme climate than cocoa in full sun
Authors: Abdulai Issaka , Vaast Philippe , Hoffmann Munir P. , Asare Richard , Jassogne Laurence , Van Asten Piet , Rötter Reimund P. , Graefe Sophie
Published: September 2017

Cocoa agroforestry is perceived as potential adaptation strategy to sub‐optimal or adverse environmental conditions such as drought. We tested this strategy over wet, dry and extremely dry periods comparing cocoa in full sun with agroforestry systems: shaded by (i) a leguminous tree species, Albizia ferruginea and (ii) Antiaris toxicaria, the most common shade tree species in the region. We monitored micro‐climate, sap flux density, throughfall, and soil water content from November 2014 to March 2016 at the forest‐savannah transition zone of Ghana with climate and drought events during the study period serving as proxy for projected future climatic conditions in marginal cocoa cultivation areas of West Africa. Combined transpiration of cocoa and shade trees was significantly higher than cocoa in full sun during wet and dry periods. During wet period, transpiration rate of cocoa plants shaded by A. ferruginea was significantly lower than cocoa under A. toxicaria and full sun. During the extreme drought of 2015/16, all cocoa plants under A. ferruginea died. Cocoa plants under A. toxicaria suffered 77% mortality and massive stress with significantly reduced sap flux density of 115 g cm−2 day−1, whereas cocoa in full sun maintained higher sap flux density of 170 g cm−2 day−1. Moreover, cocoa sap flux recovery after the extreme drought was significantly higher in full sun (163 g cm−2 day−1) than under A. toxicaria (37 g cm−2 day−1). Soil water content in full sun was higher than in shaded systems suggesting that cocoa mortality in the shaded systems was linked to strong competition for soil water. The present results have major implications for cocoa cultivation under climate change. Promoting shade cocoa agroforestry as drought resilient system especially under climate change needs to be carefully reconsidered as shade tree species such as the recommended leguminous A. ferruginea constitute major risk to cocoa functioning under extended severe drought.
Influence of UV filters on the texture profile and efficacy of a cosmetic formulation
Authors: Fossa Shirata M. M. , Campos P. M. B. G. Maia
Published: September 2017

Objective

Considering that many cosmetic products contain UV filters in their composition and that few studies have evaluated the role of UV filters in the physical properties and clinical efficacy of these products, the aim of this study was to assess the influence of UV filters on the properties and immediate effects of a cosmetic formulation.

Methods

Four cosmetic formulations, vehicle (V), vehicle containing UV filters (F), vehicle containing cassava polysaccharides and alfalfa (A) oligosaccharides and vehicle containing UV filters plus cassava polysaccharides and alfalfa oligosaccharides (multifunctional formulation, M) were developed. The texture profile of the formulations was analysed with a TA.XT plus Texturometer®. Twenty female volunteers aged 39–45 years were then selected for the assessment of immediate clinical efficacy of the formulations under study and of transepidermal water loss (TEWL), stratum corneum water content and microrelief of the skin obtained with their use.

Results

The presence of UV filters resulted in an improvement of the physical properties of the multifunctional cosmetic formulation (M) and of skin microrelief. However, the presence of UV filters also caused a significant decrease in hydration.

Conclusion

The presence of sunscreens had a negative influence on immediate skin hydration and TEWL. On the other hand, it positively influenced parameters related to the physical properties of the multifunctional formulation and skin microrelief. Thus, we conclude that the influence of UV filters on the development of cosmetic formulations is an important factor to be considered because it can have either positive or negative effect on the efficacy of the product.
The worldwide diversity of scalp seborrhoea, as daily experienced by seven human ethnic groups
Authors: Pouradier F. , Liu C. , Wares J. , Yokoyama E. , Collaudin C. , Panhard S. , Saint‐Léger D. , Loussouarn G.
Published: September 2017

Objective

The re‐greasing process and kinetics of the human scalp, post‐shampooing, have been previously documented, in vivo, on a few Caucasian subjects. The objective of the presented research was to extend such knowledge over seven different ethnic groups.

Methods

The post‐shampooing re‐greasing kinetics of the scalp was studied on 1325 subjects (women and men of two distinct age classes) from seven different ethnic groups in their residential and native country. Sebum amounts were determined onto small shaved scalp areas at various times post‐shampooing, using the Sebumeter® technique.

Results

As previously published on Caucasian subjects, scalp re‐greasing process follows a hyperbolic‐like kinetics over days. However, amounts of collected sebum highly vary with ethnicity. As recorded through the casual level (CL) at the equilibrium phase, 2–3 days post‐shampooing, the highest amount of sebum was found in African American subjects, followed in descending order by Caucasian American, Japanese, Chinese, Thai, Caucasian European and Indian subjects, the latter showing very low values. Lower amounts of sebum were recorded in the older age class in all ethnics, as compared to the younger one, and male subjects were found higher sebum producers than women, irrespective of ethnicity.

Conclusion

The kinetics and slopes of the re‐greasing process of the human scalp appear similar in all ethnic groups studied. However, striking quantitative differences are found between the seven ethnic groups, resulting from different sebaceous production levels and scalp hygiene routines.
Titanium diboride–silicon carbide–boron carbide ceramics with super‐high hardness and strength
Authors: Neuman Eric W. , Brown‐Shaklee Harlan J. , Hilmas Gregory E. , Fahrenholtz William G.
Published: September 2017

Triplex particulate composites composed of boride and carbide ceramics were found to have high strength, hardness, and fracture toughness values. Two compositions consisting of 70:15:15 and 1:1:1 volume ratios of TiB2, SiC, and B4C were produced from commercially available powders by hot‐pressing. The 70:15:15 ceramic exhibited a strength of ~1.3 GPa, while the 1:1:1 ceramic had a strength of ~0.9 GPa. These strengths are comparable to super‐strong Y2O3‐PSZ and β‐SiAlON based composites. The Vickers’ hardness values of these ceramics were ~32 GPa for indent loads of 9.8 N. Hardness increased as indentation load decreased. The 1:1:1 ceramic had a hardness of ~53 GPa at an indentation load of 0.49 N, higher than values reported for so‐called “super‐hard” ceramics, and comparable to c‐BN.
Bioactive layers based on black glasses on titanium substrates
Authors: Gawęda Magdalena , Jeleń Piotr , Długoń Elżbieta , Wajda Aleksandra , Leśniak Magdalena , Simka Wojciech , Sowa Maciej , Detsch Rainer , Boccaccini Aldo R. , Sitarz Maciej
Published: September 2017

Black glasses are amorphous materials based on silicon oxycarbide. The use of precursors in the form of ladder‐like silsesquioxanes enables the control of the amount of carbon ions in the glass network by adjusting ratios of T to D structural units in precursors. In this study, four different sols precursors of four different layers of black glasses on titanium substrates were prepared. The materials were analyzed with the use of various spectroscopic and microscopic methods. Formation of continuous and hermetic layers resistant to corrosion was proven. The black glasses layers were examined as materials for biomedical applications. Therefore, preliminary tests of their bioactivity and biocompatibility were performed. The best results were obtained for the material of lower contribution of carbon ions.
Optimal Linking Design for Response Model Parameters
Authors: Barrett Michelle D. , van der Linden Wim J.
Published: September 2017

Linking functions adjust for differences between identifiability restrictions used in different instances of the estimation of item response model parameters. These adjustments are necessary when results from those instances are to be compared. As linking functions are derived from estimated item response model parameters, parameter estimation error automatically propagates into linking error. This article explores an optimal linking design approach in which mixed‐integer programming is used to select linking items to minimize linking error. Results indicate that the method holds promise for selection of linking items.
Detecting Differential Item Discrimination (DID) and the Consequences of Ignoring DID in Multilevel Item Response Models
Authors: Lee Woo‐yeol , Cho Sun‐Joo
Published: September 2017

Cross‐level invariance in a multilevel item response model can be investigated by testing whether the within‐level item discriminations are equal to the between‐level item discriminations. Testing the cross‐level invariance assumption is important to understand constructs in multilevel data. However, in most multilevel item response model applications, the cross‐level invariance is assumed without testing of the cross‐level invariance assumption. In this study, the detection methods of differential item discrimination (DID) over levels and the consequences of ignoring DID are illustrated and discussed with the use of multilevel item response models. Simulation results showed that the likelihood ratio test (LRT) performed well in detecting global DID at the test level when some portion of the items exhibited DID. At the item level, the Akaike information criterion (AIC), the sample‐size adjusted Bayesian information criterion (saBIC), LRT, and Wald test showed a satisfactory rejection rate (>.8) when some portion of the items exhibited DID and the items had lower intraclass correlations (or higher DID magnitudes). When DID was ignored, the accuracy of the item discrimination estimates and standard errors was mainly problematic. Implications of the findings and limitations are discussed.
Assessing SSU rDNA Barcodes in Foraminifera: A Case Study using Bolivina quadrata
Authors: Borrelli Chiara , Hou Yubo , Pawlowski Jan W. , Holzmann Maria , Katz Miriam E. , Chandler G. Thomas , Bowser Samuel S.
Published: September 2017

The Small Subunit Ribosomal RNA gene (SSU rDNA) is a widely used tool to reconstruct phylogenetic relationships among foraminiferal species. Recently, the highly variable regions of this gene have been proposed as DNA barcodes to identify foraminiferal species. However, the resolution of these barcodes has not been well established, yet. In this study, we evaluate four SSU rDNA hypervariable regions (37/f, 41/f, 43/e, and 45/e) as DNA barcodes to distinguish among species of the genus Bolivina, with particular emphasis on Bolivina quadrata for which ten new sequences (KY468817–KY468826) were obtained during this study. Our analyses show that a single SSU rDNA hypervariable sequence is insufficient to resolve all Bolivina species and that some regions (37/f and 41/f) are more useful than others (43/e and 45/e) to distinguish among closely related species. In addition, polymorphism analyses reveal a high degree of variability. In the context of barcoding studies, these results emphasize the need to assess the range of intraspecific variability of DNA barcodes prior to their application to identify foraminiferal species in environmental samples; our results also highlight the possibility that a longer SSU rDNA region might be required to distinguish among species belonging to the same taxonomic group (i.e. genus).
Therapy of gastroesophageal reflux disease and functional dyspepsia overlaps with symptoms after usual‐dose proton pump inhibitor: Acotiamide plus usual‐dose proton pump inhibitor versus double‐dose proton pump inhibitor
Authors: Takeuchi Toshihisa , Takahashi Yoshiaki , Kawaguchi Shinpei , Ota Kazuhiro , Harada Satoshi , Kojima Yuichi , Sakamoto Hiroki , Kuramoto Takanori , Kojima Keishi , Sanomura Makoto , Hoshimoto Masahiro , Higashino Takeshi , Itabashi Tsukasa , Takada Ko , Sakaguchi Masahiro , Tominaga Kazunari , Kusano Motoyasu , Higuchi Kazuhide
Published: September 2017

Background and Aim

Gastroesophageal reflux disease (GERD) and functional dyspepsia (FD) often coexist or overlap. In this study, the efficacy of acotiamide in combination with a standard dose of rabeprazole for GERD and FD was compared with that of a double dose of rabeprazole.

Methods

Patients with overlap between GERD and FD experiencing heartburn and epigastric fullness symptoms after standard‐dose proton pump inhibitor (PPI) for ≥ 8 weeks were randomized into two groups and received either acotiamide 300 mg/day + rabeprazole 10 mg/day or rabeprazole 20 mg/day for 4 weeks. Efficacy was assessed by reductions in symptom scores using the Izumo scale questionnaire and modified F‐scale questionnaire.

Results

As the primary endpoint, three upper gastrointestinal symptoms (heartburn, epigastralgia, and epigastric fullness) were reduced by ≥ 50% in 40.8% and 46.9% of patients in the combination and PPI double‐dose groups, respectively, with no significant difference between the two groups. Essentially similar results were obtained for the modified F‐scale questionnaire. No serious adverse events were noted.

Conclusions

Acotiamide 300 mg/day in combination with rabeprazole 10 mg/day or rabeprazole 20 mg/day relieved symptoms in patients with overlap between GERD and FD experiencing heartburn and epigastric fullness symptoms after standard‐dose PPI for ≥ 8 weeks, and the efficacies did not differ between the two treatments. The combination therapy may be an alternative option for persistent symptoms in these patients.
Radiation‐induced changes in the microstructure of epithelial cells of the oral mucosa: A comparative light and electron microscopic study
Authors: Asikainen Pekka J. , Dekker Hannah , Sirviö Ellinoora , Mikkonen Jopi , Schulten Engelbert A. J. M. , Bloemena Elisabeth , Koistinen Arto , ten Bruggenkate Chris M. , Kullaa Arja M.
Published: September 2017

Objectives

The microplicae is a typical structure of the epithelial cell surface of the oral mucosa. The cell surface is potentially of great significance, as it provides the underlying basis for the protective function of the salivary pellicle. The aim of this study was to investigate whether radiation therapy affects the surface morphology of the superficial cells of the human oral mucosa in patients who have received radiotherapy for oral cancer.

Material and methods

Oral mucosal tissue samples from 91 patients were collected during dental implant surgery or ablative surgery. Study group 1 consisted of 28 patients who underwent dental implant surgery after radiotherapy. Group 2 consisted of five patients who developed osteoradionecrosis. Group 3 consisted of eight oral cancer patients without radiotherapy. Group 4 consisted of 50 clinically healthy subjects as controls. The samples were studied with scanning electron microscopy and compared with both light and transmission electron micrographs.

Results

Radiation therapy (RT) induces breakage and destruction in the microplicae morphology and declines the density of the microplicae surface structures. In some of the irradiated cells, the microplicae were completely vanished, especially in patients who developed osteoradionecrosis. In non‐irradiated tissue, the microplicae of the superficial epithelial cells were intact in all cases.

Conclusion

Scanning electron microscopy, in contrast to light microscopy, appears to be a useful tool to reveal the condition of superficial oral mucosal cells. In respect of the possible pathogenesis of osteoradionecrosis, the radiation‐induced damage of the microplicae and its influence on the mucosal salivary pellicle is discussed.
Effect of Body Position, Exercise, and Sedation on Estimation of Pulmonary Artery Pressure in Dogs with Degenerative Atrioventricular Valve Disease
Authors: Rhinehart J.D. , Schober K.E. , Scansen B.A. , Yildiz V. , Bonagura J.D.
Published: September 2017

Background

Severity of pulmonary hypertension (PH) in dogs is related to clinical signs and prognosis.

Hypothesis/Objectives

We hypothesized that Doppler echocardiographic (DE) indices of pulmonary artery pressure (PAP) and pulmonary vascular resistance (PVR) are influenced by independent factors that create clinically important variability of DE‐based estimates of PH in dogs.

Animals

Thirty‐eight client owned dogs with naturally acquired degenerative atrioventricular valve disease and tricuspid regurgitation (TR).

Methods

Dogs were prospectively enrolled, and target variables were acquired during 4 echocardiographic study periods (lateral recumbency, standing, lateral recumbency after a 6‐minute walk test [6MWT], and lateral recumbency after sedation with butorphanol 0.25 mg/kg IM). Statistical methods included repeated measures ANOVA, mixed model analysis, and Chi‐squared test of association.

Results

There was a significant increase in peak TR flow velocity (TRFV; P < 0.01) after sedation in 78% of dogs, with TRFV increasing by >0.4 m/s in 42% of dogs, independent of stroke volume. A significant effect of study period on DE‐estimated PVR was not found (P = 0.15). There were negligible effects of sonographer, body position, and 6MWT on echocardiographic variables of PH. Clinically relevant cyclic variation of TRFV was found. There was an association between estimation of right atrial pressure based on subjective assessment and estimation based on cranial vena cava collapsibility (P = 0.03).

Conclusions and Clinical Importance

The increase in TRFV observed with sedation could change assessment of PH severity and impact prognostication and interpretation of treatment response. Further studies with invasive validation are needed.
Suspected Phenobarbital‐Induced Pseudolymphoma in a Dog
Authors: Lampe R. , Manens J. , Sharp N.
Published: September 2017

Pseudolymphoma is a drug reaction to anti‐epileptics that is well recognized in humans; it has been reported in one cat but not dogs. In this report, lymphoma‐like clinical signs are suspected to be secondary to phenobarbital administration in a dog. A 2.5‐year‐old male, neutered Shepherd mix presented for a 3‐day history of progressive ataxia, dazed mentation, pyrexia, and lethargy. While hospitalized, the dog developed generalized lymphadenopathy and sustained pyrexia. The dog was receiving levetiracetam and phenobarbital for epilepsy, and serum concentrations of both were within standard therapeutic ranges. Abdominal ultrasound revealed hepatomegaly, splenomegaly, and generalized lymphadenopathy. Cytology of the peripheral lymph nodes was consistent with reactive lymph nodes, and aspirates of the liver and spleen revealed histiocytic‐neutrophilic inflammation. Phenobarbital was discontinued and replaced with zonisamide. Within 24 hours, the dog was normothermic, and other clinical signs resolved within a week. This case highlights a potentially serious yet reversible adverse reaction to phenobarbital in a dog. This idiosyncratic reaction could be mistaken for neoplasia and is an important differential for lymphoma‐like signs in any dog administered phenobarbital.
Demography of the Pacific walrus (Odobenus rosmarus divergens) in a changing Arctic
Authors: Taylor Rebecca L. , Udevitz Mark S. , Jay Chadwick V. , Citta John J. , Quakenbush Lori T. , Lemons Patrick R. , Snyder Jonathan A.
Published: September 2017

The Pacific walrus (Odobenus rosmarus divergens) is a candidate to be listed as an endangered species under United States law, in part, because of climate change‐related concerns. While the population was known to be declining in the 1980s and 1990s, its recent status has not been determined. We developed Bayesian models of walrus population dynamics to assess the population by synthesizing information on population sizes, age structures, reproductive rates, and harvests for 1974–2015. Candidate models allowed for temporal variation in some or all vital rates, as well as density dependence or density independence in reproduction and calf survival. All selected models indicated that the population underwent a multidecade decline, which began moderating in the 1990s, and that annual reproductive rate and natural calf survival rates rose over time in a density‐dependent manner. However, selected models were equivocal regarding whether the natural juvenile survival rate was constant or decreasing over time. Depending on whether juvenile survival decreased after 1998, the population growth rate either increased during 1999–2015 or stabilized at a lesser level of decline than seen in the 1980s. The probability that the population was still declining in 2015 ranged from 45% to 87%.
Glycerolipid analysis during desiccation and recovery of the resurrection plant Xerophyta humilis (Bak) Dur and Schinz
Authors: Tshabuse Freedom , Farrant Jill M. , Humbert Lydie , Moura Deborah , Rainteau Dominique , Espinasse Christophe , Idrissi Abdelghani , Merlier Franck , Acket Sébastien , Rafudeen Mohamad S. , Thomasset Brigitte , Ruelland Eric
Published: September 2017

Xerophyta humilis is a poikilochlorophyllous monocot resurrection plant used as a model to study vegetative desiccation tolerance. Dehydration imposes tension and ultimate loss of integrity of membranes in desiccation sensitive species. We investigated the predominant molecular species of glycerolipids present in root and leaf tissues, using multiple reaction monitoring mass spectrometry, and then analysed changes therein during dehydration and subsequent rehydration of whole plants. The presence of fatty acids with long carbon chains and with odd numbers of carbons were detected and confirmed by gas chromatography. Dehydration of both leaves and roots resulted in an increase in species containing polyunsaturated fatty acids and a decrease in disaturated species. Upon rehydration, lipid saturation was reversed, with this being initiated immediately upon watering in roots but only 12–24 hr later in leaves. Relative levels of species with short‐chained odd‐numbered saturated fatty acids decreased during dehydration and increased during rehydration, whereas the reverse trend was observed for long‐chained fatty acids. X. humilis has a unique lipid composition, this report being one of the few to demonstrate the presence of odd‐numbered fatty acids in plant phosphoglycerolipids.
Comparative proteomic profiling of the choline transporter‐like1 (CHER1) mutant provides insights into plasmodesmata composition of fully developed Arabidopsis thaliana leaves
Authors: Kraner Max E. , Müller Carmen , Sonnewald Uwe
Published: September 2017

In plants, intercellular communication and exchange are highly dependent on cell wall bridging structures between adhering cells, so‐called plasmodesmata (PD). In our previous genetic screen for PD‐deficient Arabidopsis mutants, we described choline transporter‐like 1 (CHER1) being important for PD genesis and maturation. Leaves of cher1 mutant plants have up to 10 times less PD, which do not develop to complex structures. Here we utilize the T‐DNA insertion mutant cher1–4 and report a deep comparative proteomic workflow for the identification of cell‐wall‐embedded PD‐associated proteins. Analyzing triplicates of cell‐wall‐enriched fractions in depth by fractionation and quantitative high‐resolution mass spectrometry, we compared > 5000 proteins obtained from fully developed leaves. Comparative data analysis and subsequent filtering generated a list of 61 proteins being significantly more abundant in Col‐0. This list was enriched for previously described PD‐associated proteins. To validate PD association of so far uncharacterized proteins, subcellular localization analyses were carried out by confocal laser‐scanning microscopy. This study confirmed the association of PD for three out of four selected candidates, indicating that the comparative approach indeed allowed identification of so far undescribed PD‐associated proteins. Performing comparative cell wall proteomics of Nicotiana benthamiana tissue, we observed an increase in abundance of these three selected candidates during sink to source transition. Taken together, our comparative proteomic approach revealed a valuable data set of potential PD‐associated proteins, which can be used as a resource to unravel the molecular composition of complex PD and to investigate their function in cell‐to‐cell communication.
Fuel Assembly Concept of the Canadian Supercritical Water-Cooled Reactor
Authors: Yetisir Metin , Hamilton Holly , Xu Rui , Gaudet Michel , Rhodes David , King Mitch , Andrew Kittmer , Benson Ben
Published: September 2017

The Canadian supercritical water-cooled nuclear reactor (SCWR) is a 2540 MWth channel-type SCWR concept that employs 336 fuel channels in the reactor core. Each fuel channel includes a pressure tube that is submerged in a heavy water moderator and contains a removable fuel assembly. The fuel assembly is designed so that all in-core components exposed to high radiation fields (other than the pressure tube) are part of the fuel assembly, which is removed from the reactor core as part of the assembly after three operating cycles. This design feature significantly reduces the likelihood of component failures due to radiation damage. To achieve high (>45%) power conversion efficiency, the Canadian SCWR operates at a supercritical water pressure (25 MPa) and high temperatures (350 °C at the inlet, 625 °C at the outlet). These conditions lead to fuel cladding temperatures close to 800 °C. Because of the reduced material strength at this temperature and higher fission gas production of the fuel, collapsible fuel cladding is selected over internally pressurized cladding. To increase heat transfer and to reduce cladding temperatures, turbulence-inducing wire-wraps are employed on fuel elements. Numerical models have been developed to analyze the thermal-structural behavior of Canadian SCWR fuel at normal and accident conditions. It was found that axial ridging, a possible failure mechanism with collapsed fuel cladding, can be avoided if the cladding thickness is larger than 0.4 mm. Detailed numerical analysis showed that the maximum fuel cladding temperature for the worst-case accident scenario is below the melting point by a small margin. This result was obtained with conservative assumptions, suggesting that the actual margin is greater. Hence, one of the design goals, the exclusion of the possibility of melting of the fuel, which is called the “no-core-melt” concept, seems attainable. However, this needs to be demonstrated more rigorously by removing the conservative assumptions in the analysis and performing supporting experimental work. This paper presents a description of the Canadian SCWR fuel assembly concept, its unique features, the rationale used in the concept development and the results of various numerical analyses demonstrating the performance and characteristics of the Canadian SCWR fuel channel.
Improving Heat Transfer in Hybrid Solar Systems Using Liquid Metal Alloys as a Coolant
Authors: Prabu T. , Ajay Sekar C.
Published: September 2017

An improvement in performance of hybrid solar system with use of liquid metal alloy GaInSn as a coolant has been demonstrated in this study. The performance of hybrid system using GaInSn, water, and air as coolants under different operating conditions such as ambient temperature, different inlet velocities of fluid, solar irradiations is analyzed using simulation software ANSYS and the results obtained are validated using experiments. The results obtained from simulations and experiments are used for determining important performance criteria such as electrical efficiency, thermal efficiency, and exergy efficiency. The exergy, thermal, and electrical efficiencies were found to be at least 11%, 12%, and 12% higher for hybrid system using GaInSn as a coolant when compared to hybrid systems using air and water as coolants, respectively.
Strong Azimuthal Combustion Instabilities in a Spray Annular Chamber With Intermittent Partial Blow-Off
Authors: Prieur Kevin , Durox Daniel , Schuller Thierry , Candel Sébastien
Published: September 2017

This article reports experiments carried out in the MICCA-spray combustor developed at EM2C laboratory. This system comprises 16 swirl spray injectors. Liquid n-heptane is injected by simplex atomizers. The combustion chamber is formed by two cylindrical quartz tubes allowing full optical access to the flame region and it is equipped with 12 pressure sensors recording signals in the plenum and chamber. A high-speed camera provides images of the flames and photomultipliers record the light intensity from different flames. For certain operating conditions, the system exhibits well defined instabilities coupled by the first azimuthal mode of the chamber at a frequency of 750 Hz. These instabilities occur in the form of bursts. Examination of the pressure and the light intensity signals gives access to the acoustic energy source term. Analysis of the phase fluctuations between the two signals is carried out using cross-spectral analysis. At limit cycle, large pressure fluctuations of 5000 Pa are reached, and these levels persist over a finite period of time. Analysis of the signals using the spin ratio indicates that the standing mode is predominant. Flame dynamics at the pressure antinodal line reveals a strong longitudinal pulsation with heat release rate oscillations in phase and increasing linearly with the acoustic pressure for every oscillation levels. At the pressure nodal line, the flames are subjected to large transverse velocity fluctuations leading to a transverse motion of the flames and partial blow-off. Scenarios and modeling elements are developed to interpret these features.
Large Eddy Simulation of Light-Round in an Annular Combustor With Liquid Spray Injection and Comparison With Experiments
Authors: Lancien Théa , Prieur Kevin , Durox Daniel , Candel Sébastien , Vicquelin Ronan
Published: September 2017

The light-round is defined as the process by which the flame initiated by an ignition spark propagates from burner to burner in an annular combustor, eventually leading to a stable combustion. Combining experiments and numerical simulation, it was recently demonstrated that under perfectly premixed conditions, this process could be suitably described by large eddy simulation (LES) using massively parallel computations. The present investigation aims at developing light-round simulations in a configuration that is closer to that found in aero-engines by considering liquid n-heptane injection. The LES of the ignition sequence of a laboratory scale annular combustion chamber comprising sixteen swirled spray injectors is carried out with a monodisperse Eulerian approach for the description of the liquid phase. The objective is to assess this modeling approach of the two-phase reactive flow during the ignition process. The simulation results are compared in terms of flame structure and light-round duration to the corresponding experimental images of the flame front recorded by a high-speed intensified charge-coupled device camera and to the corresponding experimental delays. The dynamics of the flow is also analyzed to identify and characterize mechanisms controlling flame propagation during the light-round process.
An Innovative Device to Enhance Conductor Bearing Capacity in Deepwater Drilling Operations
Authors: Su Kanhua , Yang Jianming , Butt Stephen
Published: September 2017

Deepwater environments raise higher demand on the bearing capacity of the drilling conductor below the mudline. To deal with this problem, a conductor bearing capacity enhancement device was designed. The setting capability of this device and its axial bearing capacity were analyzed with soil mechanics and pile theory. Furthermore, a calculation model was developed, and a numerical method was used to solve for the lateral capacity, coupled with drilling platform, riser, conductor, seabed soft soil, and the device. The result shows that proper setting depth of the device is primarily determined by the property of the soil, rather than the conductor jetting operation. Additionally, appropriate determination of the diameter and wall thickness (WT) of this device can greatly improve the lateral bearing capacity of the conductor.
Active Mixing Nozzle for Multimaterial and Multiscale Three-Dimensional Printing
Authors: Lan Hongbo
Published: September 2017

Multiscale and multimaterial three-dimensional (3D) printing is new frontier in additive manufacturing (AM). It has shown great potential to implement the simultaneous and full control for fabricated object including external geometry, internal architecture, functional surface, material composition and ratio as well as gradient distribution, feature size ranging from nano-, micro-, to macro-scale, embedded components and electrocircuit, etc. Furthermore, it has the ability to construct the heterogeneous and hierarchical structured object with tailored properties and multiple functionalities which cannot be achieved through the existing technologies. That paves the way and may result in great breakthrough in various applications, e.g., functional tissue and organ, functionally graded (FG) material/structure, wearable devices, soft robot, functionally embedded electronics, metamaterial, multifunctionality product, etc. However, very few of the established AM processes have now the capability to implement the multimaterial and multiscale 3D printing. This paper presented a single nozzle-based multiscale and multimaterial 3D printing process by integrating the electrohydrodynamic jet printing and the active mixing multimaterial nozzle. The proposed AM technology has the capability to create multifunctional heterogeneously structured objects with control of the macroscale external geometry and microscale internal structures as well as functional surface features, particularly, the potential to dynamically mix, grade, and vary the ratios of different materials. An active mixing nozzle, as a core functional component of the 3D printer, is systematically investigated by combining with the theoretical analysis, numerical simulation, and experimental verification. The study aims at exploring a feasible solution to implement the multiscale and multimaterial 3D printing at low cost.
Multiscale Stereolithography Using Shaped Beams
Authors: Mao Huachao , Leung Yuen-Shan , Li Yuanrui , Hu Pan , Wu Wei , Chen Yong
Published: September 2017

Current stereolithography (SL) can fabricate three-dimensional (3D) objects in a single-scale level, e.g., printing macroscale or microscale objects. However, it is difficult for the SL printers to fabricate a 3D macroscale object with microscale features. In the paper, a novel SL-based multiscale fabrication method is presented to address such a problem. The developed SL process can fabricate multiscale features by dynamically changing the shape and size of a laser beam. Different shaped beams are realized by switching apertures with different micropatterns. The laser beam without using micropatterns is used to fabricate macroscale features, while the shaped laser beams based on small apertures are used to fabricate micropatterned features. Accordingly, a tool path planning method for the multiscale fabrication process is presented to build macroscale and microscale features using different layer thicknesses, laser exposure time, and scanning paths. Compared with the conventional SL process using a fixed laser beam size, our process can manufacture multiscale features in a 3D object with fast fabrication speed and good surface quality.
Morphology of Voltage-Triggered Ordered Wrinkles of a Dielectric Elastomer Sheet
Authors: Mao Guoyong , Wu Lei , Liang Xueya , Qu Shaoxing
Published: September 2017

Wrinkles widely existing in sheets and membranes have attracted a lot of attention in the fields of material science and engineering applications. In this paper, we present a new method to generate ordered (striplike) and steady wrinkles of a constrained dielectric elastomer (DE) sheet coated with soft electrodes on both sides subjected to high voltage. When the voltage reaches a certain value, wrinkles will nucleate and grow. We conduct both experimental and theoretical studies to investigate the wavelength and amplitude of the wrinkle. The results show a good agreement between theory and experiment. Moreover, the amplitude and wavelength of ordered wrinkles can be tuned by varying the prestretch and geometry of the DE sheet, as well as the applying voltage. This study can help future design of DE transducers such as diffraction grating and optical sensor.
Adaptive Feedforward Control Applied in Switched Reluctance Machines Drive Speed Control in Fault Situations
Authors: Silva Wellington A. , Torrico Bismark C. , Correia Wilkley B. , dos Reis Laurinda L. N.
Published: September 2017

Many industrial and laboratory applications which make use of electric machines require noninterruption operation, even in the presence of faults, such as power generation and electric vehicles. Under fault scenarios, the performance of the system is expected to degrade and control techniques may be helpful to overcome this issue. Within this context, phase faults are obviously undesired, as may lead the machine to stop operating. Switched reluctance machines (SRM), due to its inherit characteristics, are naturally tolerant to phase faults, despite the loss of performance. Most of the techniques used to improve the performance of SRMs in fault situations are related to the switching feed converter. Regarding this issue, instead of presenting an alternative converter topology, this work alternatively proposes a control approach which significantly reduces the phase faults effects on the speed of the motor. Furthermore, the high-frequency noise is attenuated when compared to the classical proportional–integral (PI) controller, commonly applied to control such sort of motors. The proposed SRM-adaptive feedforward control (AFC) controller is able to recover the speed of operation faster than a classical approach, when a feedforward action is not taken into account.
Control-Oriented Modeling of the Dynamics of Stirling Engine Regenerators
Authors: Craun Mitchel , Bamieh Bassam
Published: September 2017

We develop a first-principles model of the regenerator component of a generic Stirling engine. The model is based on the Euler equations of one-dimensional gas dynamics coupled with its convective/conductive heat transfer with the embedded mesh material. We investigate various methods for deriving simpler and low-order control-oriented models from this first principles model, the basic criterion being high fidelity representation of the dynamics of the regenerator when coupled to other dynamic components of the engine. We identify several nondimensional parameters that potentially categorize different modes of operation, and investigate the corresponding time-scale separation. A hierarchy of singularly perturbed models is derived in which acoustic dynamics are eliminated, periodic mesh dynamics are averaged, and the shape of the distributed regenerator gas state is approximated. In addition, since the reduced model is to be operated cyclically when connected to other parts of the engine, we develop such a feedback-aware model reduction algorithm based on a proper orthogonal decomposition (POD) with a chirped signal input (chirp-POD). This algorithm yields reduced models that are accurate over a range of engine operating frequencies.
Homeodomain-like DNA binding proteins control the haploid-to-diploid transition in
Dictyostelium
Authors: Hedgethorne Katy , Eustermann Sebastian , Yang Ji-Chun , Ogden Tom E. H. , Neuhaus David , Bloomfield Gareth
Published: September 2017

Structures of social amoeba mating-type proteins suggest deep conservation of sexual differentiation processes.
Significant and stable drag reduction with air rings confined by alternated superhydrophobic and hydrophilic strips
Authors: Hu Haibao , Wen Jun , Bao Luyao , Jia Laibing , Song Dong , Song Baowei , Pan Guang , Scaraggi Michele , Dini Daniele , Xue Qunji , Zhou Feng
Published: September 2017

Drag reduction of up to 77.2% is achieved with air rings confined by alternating superhydrophobic and hydrophilic strips.
Spectral purity and tunability of terahertz quantum cascade laser sources based on intracavity difference-frequency generation
Authors: Consolino Luigi , Jung Seungyong , Campa Annamaria , De Regis Michele , Pal Shovon , Kim Jae Hyun , Fujita Kazuue , Ito Akio , Hitaka Masahiro , Bartalini Saverio , De Natale Paolo , Belkin Mikhail A. , Vitiello Miriam Serena
Published: September 2017

Difference frequency generation quantum cascade lasers are well-suited for applications requiring narrow-linewidth emitters.
Moisture-triggered physically transient electronics
Authors: Gao Yang , Zhang Ying , Wang Xu , Sim Kyoseung , Liu Jingshen , Chen Ji , Feng Xue , Xu Hangxun , Yu Cunjiang
Published: September 2017

We present a type of electronics that can be dissolved upon the presence of moisture within a controllable time scale.
What to expect when you’re expecting
Authors: Chattopadhyay Pratip K.
Published: September 2017

In this issue, Aghaeepour
et al.
apply systems immunology to study human pregnancy.
A role for T helper cells in anti–CTLA-4 therapy
Authors: Lichtman Andrew H.
Published: September 2017

Comparison of immune responses to CTLA4 and PD-1 blockade uncovers a role for helper T cells in anti–CTLA-4 therapy.
Recovery Optimization and Survival of the Human Norovirus Surrogates Feline Calicivirus and Murine Norovirus on Carpet
Authors: Buckley David , Fraser Angela , Huang Guohui , Jiang Xiuping
Published: September 2017

Carpets have been implicated in prolonged and reoccurring outbreaks of human noroviruses (HuNoV), the leading cause of acute gastroenteritis worldwide. Viral recovery from environmental surfaces, such as carpet, remains undeveloped. Our aim was to determine survival of HuNoV surrogates on an understudied environmental surface, carpet. First, we measured the zeta potential and absorption capacity of wool and nylon carpet fibers, we then developed a minispin column elution (MSC) method, and lastly we characterized the survival of HuNoV surrogates, feline calicivirus (FCV) and murine norovirus (MNV), over 60 days under 30 and 70% relative humidity (RH) on two types of carpet and one glass surface. Carpet surface charge was negative between relevant pH values (i.e., pH 7 to 9). In addition, wool could absorb approximately two times more liquid than nylon. The percent recovery efficiency obtained by the MSC method ranged from 4.34 to 20.89% and from 30.71 to 54.14% for FCV and MNV on carpet fibers, respectively, after desiccation. Overall, elution buffer type did not significantly affect recovery. Infectious FCV or MNV survived between <1 and 15 or between 3 and 15 days, respectively. However, MNV survived longer under some conditions and at significantly (
P
< 0.05) higher titers compared to FCV. Albeit, surrogates followed similar survival trends, i.e., both survived longest on wool then nylon and glass, while 30% RH provided a more hospitable environment compared to 70% RH. Reverse transcription-quantitative PCR signals for both surrogates were detectable for the entire study, but FCV genomic copies experienced significantly higher reductions (<3.80 log
10
copies) on all surfaces compared to MNV (<1.10 log
10
copies).

IMPORTANCE
Human noroviruses (HuNoV) are the leading cause of acute gastroenteritis worldwide. Classical symptoms of illness include vomiting and diarrhea which could lead to severe dehydration and death. HuNoV are transmitted by the fecal-oral or vomitus-oral route via person-to-person contact, food, water, and/or environmental surfaces. Published laboratory-controlled studies have documented the environmental stability of HuNoV on hard surfaces, but there is limited laboratory-based evidence available about survival on soft surfaces, e.g., carpet and upholstered furniture. Several epidemiological reports have suggested soft surfaces may be HuNoV fomites illustrating the importance of conducting a survival study. The three objectives of our research were to demonstrate techniques to characterize soft surfaces, develop a viral elution method for carpet, and characterize the survival of HuNoV surrogates on carpet. These results can be used to improve microbial risk assessments, the development of much-needed soft surface disinfectant, and standardizing protocols for future soft surface studies.