bluuebunny/crossref_metadata_2025 huggingface dataset:
Longitudinal changes in stream invertebrate assemblages of Grand Teton National Park, Wyoming
Authors: Tronstad Lusha M. , Hotaling Scott , Bish James C.
Published: April 2016

High elevation ecosystems are predicted to be strongly impacted by climate change; however, little is known of extant biodiversity in mountain streams. For this study, five streams in Grand Teton National Park, Wyoming were sampled along a longitudinal gradient to establish a baseline of invertebrate assemblages and environmental conditions. Five Surber samples were collected from low, middle and high elevation sites along each stream.

Nearly 10 000 ind m−2 lived in these streams on average, but the density (mixed effects model, P = 0.54) and richness (P = 0.18) of invertebrates did not vary significantly by elevation. Total density of invertebrates was positively related to the amount of visible biofilm (anova, P = 0.03) and oxidation‐reduction potential (P = 0.05) and taxa richness was negatively related to specific conductivity (P = 0.009).

Invertebrate assemblages and environmental conditions were more similar at low versus high sites when compared using non‐metric multidimensional scaling and tests of multivariate dispersion indicating that higher elevation sites harboured more environmental and species diversity.

These results can help target which aquatic invertebrates to monitor as stream temperatures rise, and highlight the biotic and abiotic factors that structure aquatic ecosystems in the Teton Range of Grand Teton National Park.
Impact of needle insertion depth on the removal of hard‐tissue debris
Authors: Perez R. , Neves A. A. , Belladonna F. G. , Silva E. J. N. L. , Souza E. M. , Fidel S. , Versiani M. A. , Lima I. , Carvalho C. , De‐Deus G.
Published: April 2016

Aim

To evaluate the effect of depth of insertion of an irrigation needle tip on the removal of hard‐tissue debris using micro‐computed tomographic (micro‐CT) imaging.

Methodology

Twenty isthmus‐containing mesial roots of mandibular molars were anatomically matched based on similar morphological dimensions using micro‐CT evaluation and assigned to two groups (n = 10), according to the depth of the irrigation needle tip during biomechanical preparation: 1 or 5 mm short of the working length (WL). The preparation was performed with Reciproc R25 file (tip size 25, .08 taper) and 5.25% NaOCl as irrigant. The final rinse was 17% EDTA followed by bidistilled water. Then, specimens were scanned again, and the matched images of the canals, before and after preparation, were examined to quantify the amount of hard‐tissue debris, expressed as the percentage volume of the initial root canal volume. Data were compared statistically using the Mann–Whitney U‐test.

Results

None of the tested needle insertion depths yielded root canals completely free from hard‐tissue debris. The insertion depth exerted a significant influence on debris removal, with a significant reduction in the percentage volume of hard‐tissue debris when the needle was inserted 1 mm short of the WL (P < 0.05).

Conclusions

The insertion depth of irrigation needles significantly influenced the removal of hard‐tissue debris. A needle tip positioned 1 mm short of the WL resulted in percentage levels of hard‐tissue debris removal almost three times higher than when positioned 5 mm from the WL.
Influences of Liquid‐Phase Sintering on Structure, Grain Growth, and Dielectric Behavior of PbZr0.52Ti0.48O3 Ceramics
Authors: Joshi Shraddha , Acharya Smita
Published: April 2016

In this work, to formulate piezoceramic systems such as PbZr0.52Ti0.48O3 (PZT) for low‐temperature co‐fired ceramic (LTCC)‐based devices, liquid‐phase sintering approach is demonstrated. ZnO–B2O3 (ZB) binary glass system is used as sintering aid. X‐ray diffraction (XRD) study confirms the formation of morphotropic phase boundary (MPB; tetragonal + rhombohedral) in PZT prepared by hydrothermal route. ZB is found to induce change in tetragonal/rhombohedral ratio in MPB of PZT. 1%ZB in PZT is found to raise the tetragonality from 71% to 92% in MPB region of PZT. ZB addition in PZT has reduced the sintering temperature from 1250 to 825°C for relative density about 91% with sustaining MPB phase. 1% ZB content is optimal percentage to enhance sinterability and relative density. Uniform dispersion of glass in PZT matrix is confirmed by SEM images. ZB content in PZT is found to controlling grain growth during sintering. Highest dielectric constant and lowest dielectric loss with low sintering temperature (825°C) of 1%ZB among all glass added in PZT exhibit technical suitability of 1%ZB + PZT to use as LTCC‐based energy storage devices.
Effects of Bi2Se3 Amount in Thermoelectric Performance of Bi2(TeSe)3 Materials Fabricated by High‐Energy Ball Milling
Authors: Rimal Pradip , Han Seung Tek , Hong Soon‐Jik , Kim Hyo‐Seob , Cho Kuk Young , Lee Ilsueuk
Published: April 2016

Amount of Bi2Se3 has significant role in controlling thermoelectric properties of n‐type Bi2(TeSe)3 material. In this study, effects of Se alloying amount in Bi2(TeSe)3 thermoelectric materials fabricated by high‐energy ball milling and spark plasma sintering were studied and compared with other fabrication methods. Amount of Bi2Se3 (5%, 10%, 15%, and 20%) did not have any significant effect over fabricated powder size, grains of consolidated bulks, and mechanical properties; however, electrical properties and thermoelectric efficiency were noticeably influenced. Both carrier concentration and carrier mobility decreased with increase in Se amount. In total, 20% Se alloying was effective in improving thermoelectric figure of merit ZT value by almost 40% compared with only 5% Se alloying.
Evolution of magnetic and bone mineral phases in heat‐treated bioactive glass containing zinc and iron oxides
Authors: Shankhwar Nisha , Singh Rajendra Kumar , Srinivasan Ananthakrishnan
Published: April 2016

Melt‐quenched 15(ZnO,Fe2O3) 50SiO2·20(CaO,P2O5) 15Na2O bioactive glass was heat treated at temperatures (TA) ranging from 550°C to 850°C for different time periods (tA=1, 2 and 3 hours) to understand its devitrification characteristics. Crystallization of calcium sodium phosphate, zinc ferrite, magnetite, and hematite phases depended on heat treatment conditions. Decrease in saturation magnetizations (Ms) with increase in tA of glass heat treated at TA≥750°C is attributed to the formation of hematite which is a weak magnetic material. Magnetic properties as functions of TA and tA are interpreted on the basis of clustering of Fe ions, super‐exchange interaction between Fe2+ and Fe3+ ions and formation of ferrimagnetic and weakly magnetic iron oxide phases with different heat treatment conditions. Electron paramagnetic resonance parameters reveal the variations in site distortions and randomness in Fe ion environment in the matrix upon heat treatment. In vitro mineralization ability of the glass‐ceramics was evaluated by immersion in simulated body fluid (SBF) and monitoring both the pH variation of SBF and formation of hydroxyapatite surface layer as a function of immersion time. These studies help in assessing these glass‐ceramics for hyperthermia treatment and in optimizing the processing conditions for this application.
High serum APRIL levels strongly correlate with disease severity in pediatric atopic eczema
Authors: Mohamed Ezzat Mohamed H. , Mohammed Ahmed A. , Ismail Rania I. H. , Shaheen Kareem Y. A.
Published: April 2016

Background

Expression of the tumor necrosis factor (TNF) family member APRIL (a proliferation‐inducing ligand) is low in normal tissues but is elevated in various autoimmune diseases.

Objectives

This study explored serum APRIL in children with atopic eczema (AE) during flare and quiescence.

Methods

A case–control study including 50 patients with AE and 40 control subjects was conducted. The severity of AE was assessed according to each of the Leicester Sign Score (LSS), the Simple Scoring System (SSS), the SCORing of Atopic Dermatitis (SCORAD) index, and the Objective SCORAD. Serum measurements of APRIL, total immunoglobulin E, and lactate dehydrogenase were obtained in all subjects. Data were obtained during both flare and quiescence in AE subjects. Data were analyzed using the Mann–Whitney U‐test and Pearson's correlation coefficient. P‐values of <0.05 were considered to indicate statistical significance.

Results

Serum APRIL levels were significantly elevated in children with AE in comparison with control subjects during both flare and quiescence (P < 0.0001 for both). Serum APRIL levels during AE flare and quiescence were positively correlated (P < 0.001). Serum APRIL levels and scores on each of the LSS, SSS, and SCORAD showed significant positive correlations (P < 0.01 for all).

Conclusions

Serum APRIL levels were significantly elevated in children with AE during both flare and quiescence. This confirms the importance of APRIL in the pathophysiology of pediatric AE. Serum APRIL is a reliable marker of the severity of AE in children. APRIL may be a new target in the treatment of AE.
Novel mutations in TGM1 and ABCA12 cause autosomal recessive congenital ichthyosis in five Saudi families
Authors: Wakil Salma M. , Binamer Yousef , Al‐Dossari Haya , Al‐Humaidy Rawan , Thuraya Rula Al , Khalifa Ola , Finsterer Josef , Meyer Brian F. , Al Owain Mohammed
Published: April 2016

Background

Autosomal recessive congenital ichthyosis (ARCI) is a rare disorder of keratinization. Infants (10–15%) born with this condition are encapsulated in hyperkeratotic membrane covering the entire body and are called “collodion babies.” So far, mutations in nine different genes have been identified as causative and implicated in the pathogenesis of the clinically and genetically heterogeneous group of ARCI disorders. Among these, TGM1 is the gene most commonly mutated in ARCI.

Methods

We identified 11 patients from five consanguineous but unrelated families affected by ARCI. These patients manifested thick adherent polygonal large scales all over the body. All six patients with TGM1 mutations were born with collodion membrane and had ectropion and eclabium, while none of the patients with ABCA12 mutations had these features. Molecular investigations were performed using the combined approach of homozygosity mapping and Sanger sequencing.

Results

Here we report two novel mutations c.397_398insAGTATGAGTA (p.Tyr136Ter); c.977‐978delCT (p.Ser326Cysfs*8) in TGM1 in three different, unrelated Saudi families and one novel mutation c.6900C>A (p.Phe2300Leu) and one reported mutation c.3470C>T (p.Ser1157Leu) in the ABCA12 gene in two unrelated Saudi families with ARCI.

Conclusions

The identification of these homozygous variants using combined approaches of homozygosity mapping with direct sequencing are the disease causing mutations in these families. Furthermore, these findings are essential for the genetic diagnostic and prognostic workup with ARCI in Saudi patients.
Low‐dose oral isotretinoin therapy in lichen planus pigmentosus: an open‐label non‐randomized prospective pilot study
Authors: Muthu Sendhil Kumaran , Narang Tarun , Saikia Uma N. , Kanwar Amrinder Jit , Parsad Davinder , Dogra Sunil
Published: April 2016

Background

Lichen planus pigmentosus (LPP) is a cosmetically distressing pigmentary disorder often posing a therapeutic challenge. Isotretinoin has been shown to be effective in oral and cutaneous LP, but its role in LPP is yet unknown.

Objective

To evaluate the efficacy and safety of isotretinoin in the management of LPP.

Methods

In this prospective study, 32 clinically and histologically proven patients with LPP were recruited. Subjects were treated with fixed low‐dose (20 mg/day) oral isotretinoin once daily for 6 months along with topical sunscreens. Response was graded as mild (<25%), moderate (26–50%), and good (>50%) improvement based on decrease in intensity and progression of hyperpigmentation.

Results

Twenty‐seven patients (17 females and 10 males), aged 20–62 years, completed the study. Twenty‐three (85.2%) patients had active disease and pruritus at presentation. Treatment outcome was moderate improvement in 15 patients (55.7%) followed by good in seven (21.8%) and mild in two (6.2%). Pruritus subsided at the earliest at 9–14 days, and disease stabilized by 4–6 weeks in treatment‐responsive patients. Patients with a shorter duration (≤5 years) of disease and limited body area involvement had a better outcome.

Conclusions

Low‐dose isotretinoin seems to be a promising treatment modality in stabilizing and decreasing the pigmentation in LPP particularly in early and limited disease.
A survey of coagulation laboratory practices and satisfaction ratings of member laboratories of the Thailand National External Quality Assessment Scheme for blood coagulation
Authors: Chuntarut A. , Tientadakul P. , Wongkrajang P.
Published: April 2016

Introduction

The Thailand National External Quality Assessment Scheme (NEQAS) for blood coagulation was established in 2005. The objective of this study was to collect data of coagulation laboratory practices and satisfaction of NEQAS member.

Methods

Two hundred seventy‐six questionnaires were sent to laboratories that are members of NEQAS to obtain data relating to coagulation laboratory practice and satisfaction in 2014. Data from this survey were compared with data from the survey conducted in 2005 to evaluate levels of improvement.

Results

Of 276 questionnaires sent, 212 (76.8%) were returned. Improvements were characterized by the number of laboratories that (i) decreased use of 3.8% sodium citrate as anticoagulant; (ii) implemented use of at least two control levels for internal quality control; and (iii) implemented reporting of reference values with results, as well as establishing their own reference range and using geometric mean as the denominator for international normalized ratio calculation. For overall satisfaction, 179 of 206 (86.9%) participant laboratories reported being satisfied or very satisfied.

Conclusion

Improvements in coagulation laboratory practices in Thailand were observed in every step of the total testing process. However, additional improvements are still needed, such as determination and use of a local reference range.
Monoclonal B‐cell lymphocytosis in the population of Slovenian region of Lower Carniola
Authors: Bajuk P. , Furlan T. , Černelč P. , Čeh M. , Podgornik H.
Published: April 2016

Introduction

Monoclonal B‐cell lymphocytosis (MBL) is a premalignant asymptomatic condition characterized by the presence of a small population of monoclonal B lymphocytes (less than 5 × 109/L) in the venous blood of otherwise healthy individuals. Incidence of MBL is higher among first‐degree relatives of patients with chronic lymphocytic leukemia (CLL) and also increases with age and among men. We compared the incidence of MBL found in the same environment in both an open general population and relatives of CLL patients.

Methods

Samples were analyzed with 5‐parameter flow cytometry using following monoclonal antibodies: kappa and lambda clonality, CD5, CD19, CD20. We analyzed 216 samples of patients in the Slovenian area of Lower Carniola aged 23–88 years. Fifty‐four patients who came from families where CLL is present were compared by age and gender to 162 healthy individuals from the general population of the same region.

Results

We found 10 cases of MBL (4.6%). In 9.4% of younger (≤ 50 years) first‐degree relatives of CLL patients with immunophenotypic characteristics of atypical MBL, we observed a prevailingly normal κ to λ ratio. The difference in incidence of MBL cases between relatives and the general population decreases with age.

Conclusion

MBL in Slovenia can be coincidentally found with a similar frequency to previously studied populations of other parts of Europe. We found, however, a higher incidence of atypical MBL among first‐degree relatives.
Conceptualising the politics of social protection expansion in low income countries: The intersection of transnational ideas and domestic politics
Authors: Lavers Tom , Hickey Sam
Published: April 2016

The growing literature on social protection in low income developing countries has tended to focus on definitional debates, policy design and impact evaluations, with relatively little consideration of the ways in which politics shape policy. This article argues that politics needs to be at the centre of efforts to understand social protection and outlines a new conceptual framework for investigating this, with a particular focus on explaining the variation in progress made by low income countries in adopting and implementing social protection. We propose that an adapted ‘political settlements’ framework that incorporates insights from the literatures on welfare state development – notably ‘power constellations’ theory, discursive institutionalism and global policy networks – can help frame political commitment to social protection as flowing from the interaction of domestic political economy and transnational ideas. Importantly, this approach situates social protection within a broader political and policy context, and highlights the influence of underlying power relations at multiple levels.
Differences in neurotransmitter systems of ventrolateral periaqueductal gray between the micturition reflex and nociceptive regulation: An in vivo microdialysis study
Authors: Kitta Takeya , Mitsui Takahiko , Kanno Yukiko , Chiba Hiroki , Moriya Kimihiko , Yoshioka Mitsuhiro , Shinohara Nobuo
Published: April 2016

Objectives

To elucidate the possible involvement of glutamate and serotonin (5‐hydroxytryptamine) neurons in the ventrolateral midbrain periaqueductal gray during noxious stimulation.

Methods

The study was carried out by evoking a noxious stimulation by acetic acid in an animal model of cystitis. Changes in glutamate and 5‐hydroxytryptamine in the periaqueductal gray during the micturition reflex and acetic acid‐induced cystitis were determined using in vivo microdialysis combined with cystometry in rats.

Results

Extracellular glutamate levels slightly, but significantly, increased during the micturition reflex induced by saline infusion into the bladder. Intravesical infusion of acetic acid facilitated the micturition reflex characterized by increases in voiding pressure and decreases in the intercontraction interval. Glutamate levels were markedly increased by acetic acid, and this enhancement was sustained for at least 3 h. 5‐Hydroxytryptamine levels, which were not altered during the micturition reflex, were increased after intravesical infusion of acetic acid.

Conclusion

The results suggest that periaqueductal gray glutamate and 5‐hydroxytryptamine neurons differentially participate in the modulation of both nociception and the micturition reflex. Furthermore, periaqueductal gray 5‐hydroxytryptamine levels appear to reflect the nociceptive stimuli.
DACA and the Surge in Unaccompanied Minors at the US‐Mexico Border
Authors: Amuedo‐Dorantes Catalina , Puttitanun Thitima
Published: April 2016

Apprehensions of unaccompanied minors from Central American countries have been on the rise since 2008, but news reports particularly caught up with the increase after 2012. Some politicians posited that the 2012 Deferred Action for Childhood Arrivals (DACA) contributed to the surge by creating the expectation that children would be allowed to stay in the country. Immigration advocates, however, believe that the two are not related. Using data on apprehensions of unaccompanied minors by border patrol sector, nationality and year, we find that DACA did not significantly impact those apprehensions. Rather, the 2008 Williams Wilberforce Trafficking Victims Protection Reauthorization Act, along with violence in the originating countries and economic conditions in both the countries of origin and the United States, emerge as some of the key determinants of the recent surge in unaccompanied minors apprehended along the southwest US‐Mexico border.
Supply chain performance under pull or push contracts in the presence of a market disruption
Authors: Wang Ningning , Fang Xiang , Gou Qinglong , Liang Liang
Published: April 2016

Recently, market disruptions are more prone to emerging in supply chains. To investigate the impact of such a phenomenon on the performance of supply chain members and the entire supply chain, we consider a two‐tier supply chain that consists of one manufacturer (he) and one retailer (she). The retailer orders products from the manufacturer and then sells them to a market in the presence of a potential market disruption caused by a random event. According to the timing of the retailer's order, we study two types of wholesale price contracts, that is, the pull contract (the retailer orders only during the selling season and the manufacturer bears the full inventory risk) and the push contract (the retailer only orders before the selling season starts and bears the full inventory risk). We derive the equilibrium wholesale prices, retail prices, production quantities, order quantities, and corresponding profits under each contract, respectively. By making a comparison between these two types of contracts, we find that when the potential market disruption is severe, the pull contract performs better than the push contract for the supply chain, while the push contract is more attractive for the supply chain when the potential market disruption is relatively mild. Moreover, the manufacturer always prefers the push contract, and the retailer always prefers the pull contract. We also show that the pull or push contract with revenue sharing can still coordinate the supply chain with the potential market disruption.
Relationship Between Electronic Structures and Capacitive Performance of the Electrode Material IrO2–ZrO2
Authors: Shao Yan‐Qun , Chen Zhi‐Jie , Zhu Jun‐Qiu , Zhang Shuai , Lin De‐Yuan , Yi Zhao‐Yu , Tang Dian
Published: April 2016

First‐principles calculations were employed to study the effects of the addition of ZrO2 on the electrochemical activity and structure of Ir–Zr binary oxide. In the computation model employed, Zr atoms replaced Ir atoms in IrO2 supercells, so as to form a rutile‐type solid solution of Ir1−xZrxO2 (0 ≤ x ≤ 1). IrO2–ZrO2 oxide coatings were prepared on Ti substrates by thermal decomposition. X‐ray diffraction (XRD) analyses, cyclic voltammetry, and galvanostatic charge/discharge tests were performed to investigate the effects of the Zr content on the structure and capacitive performance of the synthesized Ti/IrO2–ZrO2 electrodes. As the Zr content was increased, the density of state of Ir1−xZrxO2 moved to a higher energy level, and a forbidden band was formed, which reduced its electronic conductivity. The XRD analyses showed that ZrO2 restrained the crystallization of IrO2. Thus, the extent of the amorphous phase increased with the increase in the ZrO2 content, indicating that the proton conductivity of the binary oxide coating increased with the ZrO2 content. When the ZrO2 content was higher than 50 mol%, the IrO2–ZrO2 coating exhibited a relatively narrow energy band gap (0.42eV) and a “amorphous/crystalline” structure, as well as the highest charge capability, indicating that its electronic and protonic conductivities had reached an equilibrium. This was in accordance with the sudden variation in the length of the M‐O bond and the change in the bulk modulus.
Design Strategy for the Multilayer Core–Shell Bioceramics with Controlled Chemistry
Authors: Liu Limin , He Dongshuang , Yang Xianyan , Zhang Lei , Yang Guojing , Dai Xuesong , Gou Zhongru
Published: April 2016

New strategies for fabricating multiphase bioceramic porous scaffolds with time‐dependent biodegradation and pore network enlargement are of fundamental importance in the advancement of bioceramics. Here, we developed a one‐step preparation of core–shell bioceramic microspheres (~2 mm in diameter) with single‐ or double‐shell structure through a coaxially aligned multilayer capillary system. The Ca‐phosphate (CaP) and Ca‐silicate (CaSi) ceramic phase distribution could be also adjusted by extruding through different capillaries, and thus the biodegradation rate would be readily tailored over time. When the polystyrene (PS) microbeads of ~15 μm in diameter were premixed into the CaP‐ or CaSi‐containing alginate slurry, the tailorable porous structures could be introduced into the core or different shell layers of the microspheres. These micropores may potentially maximize the permeability for rapid exchange of guest molecules or inorganic ions from the bioceramics. Totally, such strategy is promising because the ceramic phases with different biological properties can be assembled into the core–shell bioceramic microspheres, and thus the macropore structure evolution may be readily manipulated in the closely packed microsphere systems. We believe our gradient hybrid methodology will have potential in various categories of advanced biomaterials of organic–inorganic composites.
Electrode Effects on Microstructure Formation During FLASH Sintering of Yttrium‐Stabilized Zirconia
Authors: Qin Wei , Majidi Hasti , Yun Jondo , van Benthem Klaus
Published: April 2016

Systematic microstructural statistics for 3 mol% yttria‐stabilized zirconia synthesized by both conventional sintering and flash sintering with AC and DC current were obtained. Within the gage section, flash sintered microstructures were indistinguishable from those synthesized by conventional sintering procedures. With both techniques, full densification was obtained. However, from both AC and DC flash sintered specimens, heterogeneous grain size distributions and residual porosity were observed in the proximity of the electrodes. After DC sintering, an almost 400 times increased average grain size was observed near cathode compared to the gage section, unlike areas close to the anode. Concepts of Joule heating alone were not sufficient to explain the experimental observations. Instead, the activation energy for grain growth close to the cathode is lowered considerably during flash sintering, hence suggesting that electrode effects can cause significant heterogeneities in microstructure evolution during flash sintering. Microstructural characterization further indicated that microfracturing during green‐pressing and variations in contact resistance between the electrodes and the ceramic may also contribute to grain size gradients and hence local variations of physical properties.
High‐Strength B4C–TaB2 Eutectic Composites Obtained via In Situ by Spark Plasma Sintering
Authors: Demirskyi Dmytro , Sakka Yoshio , Vasylkiv Oleg
Published: April 2016

The in situ synthesis/consolidation of B4C–TaB2 eutectic composites by spark plasma sintering (SPS) is reported. Samples for the evaluation of bending strength were cut from specimens with diameters of 30 mm. The sample prepared for the three‐point flexural strength test had fibers of tantalum diboride with diameter of 1.3 ± 0.4 μm distributed in the B4C matrix, thereby reducing composites brittleness and yielding an indentation fracture toughness of up to 4.5 MPa·m1/2. Furthermore, the Vickers hardness of B4C–TaB2 eutectics formed by SPS was as high as 26 GPa at an indentation load of 9.8 N. The flexural strength of the B4C–TaB2 system has been reported for the first time. Some steps were identified in the load–displacement curve, suggesting that micro‐ and macrocracking occurred during the flexural test. Ceramic composites with a eutectic structure exhibited a room‐temperature strength of 430 ± 25 MPa. Compared with other eutectic composites of boron carbide with transition‐metal diborides, room‐temperature strength the B4C–TaB2 was 40% higher than that of B4C–TiB2 ceramics, demonstrating advantage of the in situ synthesis/consolidation of eutectic composites by SPS.
Theoretical Study on the Relationship Between Crystal Chemistry and Properties of Quaternary Y–Si–O–N Oxynitrides
Authors: Sun Luchao , Liu Bin , Wang Jiemin , Li Zhen , Wang Jingyang
Published: April 2016

Y–Si–O–N quaternary oxynitrides (Y5Si3O12N, Y4Si2O7N2,YSiO2N, Y2Si3O3N4, and Y3Si5ON9) are recognized as important secondary grain‐boundary phases in silicon nitride and believed to have important impacts on the high‐temperature mechanical properties and thermal conductivity of Si3N4ceramic. In this work, equilibrium crystal structures, theoretical mechanical properties (second‐order elastic constants, polycrystalline bulk modulus,shear modulus,Young's modulus, and Vickers hardness) of the five quaternary phases are calculated using first‐principle total energy calculations. Meanwhile, temperature dependence of thermal conductivities of all five compounds is obtained based on Debye–Clarke model and Slack equation. On the basis of theoretical prediction, we establish the relationship between the componential (cation/anion or cation/cation ratios) and structural characteristics (bonding configurations) and mechanical/thermal properties. Our results are expected to provide helpful guidelines to improve the performances of Y–Si–O–N ceramics, and further guide the optimization of mechanical and thermal properties of Si3N4by properly tailoring the secondary grain‐boundary phases.
Antiferroelectric to Ferroelectric Crossover and Energy Storage Properties of (Pb1−xLax)(Zr0.90Ti0.10)1−x/4O3 (0.02 ≤ x ≤ 0.04) Ceramics
Authors: Ciuchi Ioana Veronica , Mitoseriu Liliana , Galassi Carmen
Published: April 2016

Polarization switching behavior and energy storage performances of (Pb1−xLax)(Zr0.90Ti0.10)1−x/4O3 (PLZT x/90/10) ceramics with La compositions across the ferroelectric/antiferroelectric phase boundary, which show variable amount of antiferroelectric (AFE) orthorhombic and ferroelectric (FE) rhombohedral phases, were investigated. A low AFE to FE switching field was obtained and its value could be adjusted by La chemical modification. While the PLZT system evolves from a FE state to an AFE state as a function of La content and from an AFE state to a FE state as a function of the applied electric field, the recoverable energy (Wre) and loss energy (Wloss) range between two limits whose lower and higher values are obtained for PLZT composition in AFE state and FE state, respectively. In terms of the extent of La‐modification, the Wre has been enhanced from 0.819 J/cm3 (for PLZT 2/90/10 and electric field of ~30 kV/cm) to the highest value of 1.85 J/cm3 (for PLZT 3.5/90/10 and electric field ~65 kV/cm), followed by their subsequent reduction.
Electrical Properties and Relaxor Phase Evolution of Li‐Modified BNT‐BKT‐BT Lead‐Free Ceramics
Authors: Yin Dong‐Sheng , Zhao Zhi‐Hao , Dai Ye‐Jing , Zhao Zhe , Zhang Xiao‐Wen , Wang Si‐Hui
Published: April 2016

By conventional ceramics sintering technique, the lead‐free 0.85Bi0.5Na0.5(1−x)Li0.5xTiO3‐0.11Bi0.5K0.5TiO3‐0.04BaTiO3 (x =0–0.15) piezoelectric ceramics were obtained and the effects of Li dopant on the piezoelectric, dielectric, and ferroelectric properties were studied. With increasing Li addition, the temperature‐dependent permittivity exhibited the normal ferroelectric‐to‐ergodic relaxor (FE‐to‐ER) transition temperature (TFE‐ER, abbreviated as TF‐R) decreasing down to room temperature. The increasing Li content also enhanced the diffuseness of the FE‐to‐ER transition behavior. For composition with x = 0.15, a large unipolar strain of 0.37% ( = Smax/Emax = 570 pm/V) was achieved under 6.5 kV/mm applied electric field at room temperature. Both unipolar and bipolar strain curves related to the temperature closely, and when the temperature reached the TF‐R, the normalized strain achieved a maximum value (e.g., for x = 0.10, = 755 pm/V) owing to the electric‐field‐induced ER‐to‐FE state transition.
Improved Crack Healing and High‐Temperature Oxidation Resistance of Ni/Al2O3 by Y or Si Doping
Authors: Maruoka Daisuke , Nanko Makoto
Published: April 2016

Recovery of mechanical strength was investigated for 5 vol% Ni/α‐Al2O3 nanocomposites that had improved resistance to high‐temperature oxidation by doping with Y or Si (Ni/Al2O3‐Y and Ni/Al2O3‐Si). Surface cracks disappeared completely because of the oxidation product, NiAl2O4. The fraction of crack disappearance was comparable between Ni/Al2O3‐Y and Ni/Al2O3‐Si. The apparent activation energy of crack healing is similar to the grain‐boundary diffusion of Ni ions in an Al2O3 matrix. The rate‐controlling process of crack healing is the grain‐boundary diffusion of cations in an internally oxidized zone (IOZ) of the Ni/Al2O3 system. The bending strengths of the as‐sintered and as‐cracked Ni/Al2O3‐Y samples were 561 and 232 MPa, respectively. Heat treatment at 1200°C for 6 h resulted in a recovery of the bending strength up to 662 MPa for Ni/Al2O3‐Y as well as 606 MPa for Ni/Al2O3‐Si. Y and Si dopants were segregated into the Al site at the Al2O3 grain boundaries, and then, enhanced covalent bonding occurred with neighboring oxygen. While the flux of Ni ions was retarded slightly by doping with Y and Si, a shorter IOZ provided enough Ni ions to form NiAl2O4 on the surface. Ni/Al2O3‐Y and Ni/Al2O3‐Si have the desirable properties of crack healing and resistance to high‐temperature oxidation.
Destined to Design? How and Why Australian Women Choose to Study Industrial Design
Authors: Lockhart Cathy , Miller Evonne
Published: April 2016

Despite over three decades of legislation and initiatives designed to tackle the traditional gender divide in the science, technology and design fields, only a quarter of the registered architects in Australia are women. There are no statistics available for other design disciplines, with little known about why women choose design as a career path and who or what influences this decision. This qualitative research addresses this knowledge gap, through semi‐structured in‐depth interviews conducted with 19 Australian women who completed an industrial (product) design degree. Thematic analysis revealed three key themes: childhood aptitude and exposure; significant experiences and people; and design as a serendipitous choice. The findings emphasise the importance of early exposure to design as a potential career choice, highlighting the critical role played by parents, teachers, professionals and social networks.
‘Global health’ and ‘global nursing’: proposed definitions from The Global Advisory Panel on the Future of Nursing
Authors: Wilson Lynda , Mendes Isabel Amelia Costa , Klopper Hester , Catrambone Cathy , Al‐Maaitah Rowaida , Norton Mary E. , Hill Martha
Published: April 2016

Aims

To propose definitions of global health and global nursing that reflect the new paradigm that integrates domestic and international health.

Background

Increased globalization has led to expanded awareness of the importance of global health and global nursing among students and faculty in the health professions and among policymakers and practitioners.

Design

Discussion paper that includes a discussion and review of the literature related to global health and global nursing.

Data sources

A task force searched for and reviewed articles published in English, Spanish or Portuguese between 2005‐2015, developed summaries, listed key elements, identified prevalent themes and developed consensus definitions.

Implications for nursing

The definitions will be used by the Global Advisory Panel on the Future of Nursing to guide promoting a voice and vision for nursing that will contribute to the advancement of the profession's contribution to global health.

Conclusions

Definitions of global health and global nursing were developed based on main themes and concepts identified in the literature review to guide contributions of nursing to global health.
The role of social dominance orientation and patriotism in the evaluation of racial minority and female leaders
Authors: Hoyt Crystal L. , Simon Stefanie
Published: April 2016

This research broadens our understanding of racial and gender bias in leader evaluations by merging implicit leadership theory and social dominance perspectives. Across two experimental studies (291 participants), we tested the prediction that bias in leader evaluations stemming from White and masculine leader standards depends on the extent to which people favor hierarchical group relationships (social dominance orientation) and their level of patriotism. Employing the Goldberg paradigm, participants read identical leadership speeches attributed to either a woman or a man described as either a minority (Black or Latino/a) or a majority (White) group member. Results show social dominance orientation negatively predicted evaluations of minority and female leaders and patriotism positively predicted evaluations of White leaders.
The Information Content of Corporate Pension Funding Status in Japan
Authors: Goto Shingo , Yanase Noriyoshi
Published: April 2016

This paper tests if a firm's pension funding ratio (pension assets/PBO) reveals the management's private information about the firm's operation when the firm can exercise discretion in pension funding. The lax enforcement of pension funding rules and the prevalence of management forecasts make Japanese firms an ideal testing ground. We show that, among firms with large business uncertainty, large accruals, or high effective tax rates, the pension funding ratio predicts the firm's management forecast errors significantly beyond conventional control variable and the effects of pension accounting management. However, the stock market does not appear to incorporate this information immediately.
Individual Large Shareholders, Earnings Management, and Capital‐Market Consequences
Authors: Dou Yiwei , Hope Ole‐Kristian , Thomas Wayne B. , Zou Youli
Published: April 2016

Using a large hand‐collected sample of all blockholders (ownership ≥ 5%) of S&P 1500 firms for the years 2002–2009, we first document significant individual blockholder effects on earnings management (accrual‐based earnings management, real earnings management, and restatements). This association is driven primarily by these large shareholders influencing rather than selecting firms’ financial reporting practices. Second, the market's reaction to earnings announcements suggests that investors recognize the heterogeneity in blockholders’ influence on earnings management. The results highlight the highly individualized effects of blockholders and a mechanism through which shareholders impact reported earnings.
From the north into the Himalayan–Hengduan Mountains: fossil‐calibrated phylogenetic and biogeographical inference in the arctic‐alpine genus Diapensia (Diapensiaceae)
Authors: Hou Yan , Bjorå Charlotte Sletten , Ikeda Hajime , Brochmann Christian , Popp Magnus
Published: April 2016

Aim

Many arctic species are believed to be descendants from ancestors that migrated northwards from high mountains during the formation of the modern arctic biome 2–3 million years ago (Ma). Here, we test whether this hypothesis is consistent with the biogeographical history of the arctic‐alpine genus Diapensia, which shows a disjunction between the Arctic and the Himalayan–Hengduan Mountains (HHM).

Location

The Arctic/sub‐Arctic and the HHM.

Methods

We used the plastid DNA (pDNA) sequences matK and rbcL and seven Ericales fossils to date the origin of Diapensia. Sequences of four pDNA markers and the nuclear ribosomal internal transcribed spacer from 56 Diapenisa accessions were then used to reconstruct the phylogenetic relationships and time of divergence among Diapensia species.

Results

Diapensia consists of three major clades; two corresponding to the two arctic species, and one containing the two HHM species sampled. Both the pDNA tree and the species tree resolved the amphi‐Beringian D. obovata as sister to a clade that included D. lapponica that has an amphi‐Atlantic distribution and the HHM clade. The two arctic species were estimated to have originated in the Middle Miocene‐Early Pliocene (D. obovata: 8.3 Ma, 95% highest posterior probability density (HPD) 4.0–13.5 Ma; D. lapponica: 7.1 Ma, 95% HPD 4.1–10.0 Ma), long before the formation of the modern arctic biome. In contrast, species divergence in the HHM clade was found to be very recent (0.5 Ma, 95% HPD 0.2–0.9 Ma; Early‐Middle Pleistocene).

Main conclusions

Our results reject an HHM origin of the arctic Diapensia and rather suggest that the ancestor of the D. lapponica/HHM clade migrated southwards into the HHM. This study adds to a growing body of evidence suggesting that arctic plant lineages have diverse origins in time and space.
Diversity in insect seed parasite guilds at large geographical scale: the roles of host specificity and spatial distance
Authors: Bonal Raúl , Espelta Josep M. , Muñoz Alberto , Ortego Joaquín , Aparicio José Miguel , Gaddis Keith , Sork Victoria L.
Published: April 2016

Aim

Host specificity within plant‐feeding insects constitutes a fascinating example of natural selection that promotes inter‐specific niche segregation. If specificity is strong, composition of local plant parasitic insect guilds is largely dependent on the presence and prevalence of the preferred hosts. Alternatively, if it is weak or absent, historic and stochastic demographic processes may drive the structuring of insect communities. We assessed whether the species composition of acorn feeding insects (Curculio spp. guilds) and their genetic variation change geographically according to the local host community.

Location

An 800 km transect across California, USA.

Methods

We used DNA taxonomy to detect potential Curculio cryptic speciation and assessed intra‐specific genetic structure among sampling sites. We monitored larval performance on different hosts, by measuring the weight of each larva upon emerging from the acorn. Our phylogenetic and spatial analyses disentangled host specificity and geographical effects on Curculio community composition and genetic structure.

Results

DNA taxonomy revealed no specialized cryptic species. Californian Curculio spp. were sister taxa that did not segregate among Quercus species or, at a deeper taxonomic level, between red and white oaks. Curculio species turnover and intra‐specific genetic differentiation increased with geographical distance among localities irrespective of local oak species composition. Moreover, larval performance did not differ among oak species or acorn sizes when controlling for the effect of the locality.

Main conclusions

Historical processes have contributed to the structuring of acorn weevil communities across California. Trophic niche overlapped among species, indicating that ecologically similar species can co‐exist. Acorn crop inter‐annual variability and unpredictability in mixed oak forests may have selected against narrow specialization, and facilitated co‐existence by means of an inter‐specific time partitioning of the resources. Wide‐scale geographical records of parasitic insects and their host plants are necessary to understand the processes underlying species diversity.
Interactive computer simulation and animation for improving student learning of particle kinetics
Authors: Fang N. , Guo Y.
Published: April 2016

Computer simulation and animation (CSA) has been receiving growing attention and wide application in engineering education in recent years. A new interactive CSA module was developed in the present study to improve student learning of particle kinetics in an undergraduate engineering dynamics course. The unique feature of this CSA module is that it integrates computer visualization with mathematical modeling, so students can directly connect engineering dynamics phenomena to underlying mathematics. A quasi‐experimental pretest–post‐test research design including a comparison group (n = 65) and an intervention group (n = 77) was implemented to assess to what extent the developed CSA module improved student learning. The results show that this new CSA module increased students' class‐average conceptual and procedural learning gains by 29% and 37% respectively. The difference in learning gains between the two groups is statistically significant (Z = −4.526, p = 0.000) based on a nonparametric statistical Mann–Whitney U test. It is found that the improvement of students' conceptual understanding and the improvement of their procedural skills are asymmetrical in this CSA learning environment. The CSA module can serve as an excellent tool to supplement traditional lectures, but cannot fully replace human teachers or tutors in teaching.
Instructor accents in online education and their effect on learning and attitudes
Authors: Sanchez C. A. , Khan S.
Published: April 2016

Reductions in perceptual fluency have been shown to negatively impact attitudes towards learning material, but not learning itself. The current study extends this work to spoken presentations and examines whether the presence of a foreign accent negatively affects learners' experience in an online learning environment. Results indicate that the presence of an instructor accent, consistent with prior work on perceptual fluency, does not impact learning, but does cause learners to rate the instructor as less effective. Further, for those who received accented presentations, changes in participants' attitudes towards both the content area and online instruction were not predicted by learning, but instead their attitude towards the instructor. This suggests that learners in online learning environments with accented narration are potentially miscalibrated, and these biases in judgement could be inappropriately linked to a specific instructor, rather than their success of learning in the field.
Lmbrd1 expression is essential for the initiation of gastrulation
Authors: Buers Insa , Pennekamp Petra , Nitschke Yvonne , Lowe Chrishanthi , Skryabin Boris V. , Rutsch Frank
Published: April 2016

The rare inborn cblF defect of cobalamin metabolism is caused by mutations in the limb region 1 (LMBR1) domain containing 1 gene (LMBRD1). This defect is characterized by massive accumulation of free cobalamin in lysosomes and loss of mitochondrial succinyl‐CoA synthesis and cytosolic methionine synthesis. Affected children suffer from heart defects, developmental delay and megaloblastic anemia. LMBRD1 encodes for LMBD1, a predicted lysosomal cobalamin transport protein. In this study, we determine the physiological function of LMBRD1 during embryogenesis by generating Lmbrd1 deficient mice using the Cre/LoxP system. Complete loss of Lmbrd1 function is accompanied by early embryonic death in mice. Whole mount in situ hybridization studies against bone morphogenetic protein 4 and Nodal show that initial formation of the proximal–distal axis is unaffected in early embryonic stages whereas the initiation of gastrulation is disturbed shown by the expression pattern of even skipped homeotic gene 1 and fibroblast growth factor 8 in Lmbrd1 deficient mice. We conclude that intact function of LMBD1 is essential for the initiation of gastrulation.
Insulin‐like growth factors and their potential role in cardiac epigenetics
Authors: Iosef Husted Cristiana , Valencik Maria
Published: April 2016

Cardiovascular disease (CVD) constitutes a major public health threat worldwide, accounting for 17.3 million deaths annually. Heart disease and stroke account for the majority of healthcare costs in the developed world. While much has been accomplished in understanding the pathophysiology, molecular biology and genetics underlying the diagnosis and treatment of CVD, we know less about the role of epigenetics and their molecular determinants. The impact of environmental changes and epigenetics in CVD is now emerging as critically important in understanding the origin of disease and the development of new therapeutic approaches to prevention and treatment. This review focuses on the emerging role of epigenetics mediated by insulin like‐growth factors‐I and ‐II in major CVDs such as heart failure, cardiac hypertrophy and diabetes.