bluuebunny/crossref_metadata_2025 huggingface dataset:
Non‐stationary model of oblique x‐ray incidence in amorphous selenium detectors: I. Point spread function
Authors: Acciavatti Raymond J. , Maidment Andrew D. A.
Published: November 2018

Purpose

In previous work, a theoretical model of the point spread function (PSF) for oblique x‐ray incidence in amorphous selenium (a‐Se) detectors was proposed. The purpose of this paper is to develop a complementary model that includes two additional features. First, the incidence angle and the directionality of ray incidence are calculated at each position, assuming a divergent x‐ray beam geometry. This approach allows the non‐stationarity of the PSF to be modeled. Second, this paper develops a framework that is applicable to a digital system, unlike previous work which did not model the presence of a thin‐film transistor (TFT) array.

Methods

At each point on the detector, the incidence angle and the ray incidence direction are determined using ray tracing. Based on these calculations, an existing model for the PSF of the x‐ray converter (Med Phys. 1995;22:365‐374) is generalized to a non‐stationary model. The PSF is convolved with the product of two rectangle functions, which model the sampling of the TFT array. The rectangle functions match the detector element (del) size in two dimensions.

Results

It is shown that the PSF can be calculated in closed form. This solution is used to simulate a digital mammography (DM) system at two x‐ray energies (20 and 40 keV). Based on the divergence of the x‐ray beam, the direction of ray incidence varies with position. Along this direction, the PSF is broader than the reference rect function matching the del size. The broadening is more pronounced with increasing obliquity. At high energy, the PSF deviates more strongly from the reference rect function, indicating that there is more blurring. In addition, the PSF is calculated along the polar angle perpendicular to the ray incidence direction. For this polar angle, the shape of the PSF is dependent upon whether the ray incidence direction is parallel with the sides of the detector. If the ray incidence direction is parallel with either dimension, the PSF is a perfect rectangle function, matching the del size. However, if the ray incidence direction is at an oblique angle relative to the sides of the detector, the PSF is not rectangular. These results illustrate the non‐stationarity of the PSF.

Conclusions

This paper demonstrates that an existing model of the PSF of a‐Se detectors can be generalized to include the effects of non‐stationarity and digitization. The PSF is determined in closed form. This solution offers the advantage of shorter computation time relative to approaches that use numerical methods. This model is a tool for simulating a‐Se detectors in future work, such as in virtual clinical trials with computational phantoms.
Multishot diffusion‐prepared magnitude‐stabilized balanced steady‐state free precession sequence for distortion‐free diffusion imaging
Authors: Gao Yu , Han Fei , Zhou Ziwu , Zhong Xiaodong , Bi Xiaoming , Neylon John , Santhanam Anand , Yang Yingli , Hu Peng
Published: November 2018

Purpose

To develop and evaluate a multishot diffusion‐prepared (DP) magnitude‐stabilized balanced steady‐state free precession (bSSFP) diffusion imaging sequence with improved geometric fidelity.

Methods

A signal spoiler (magnitude stabilizer; MS) was implemented in a DP‐bSSFP diffusion sequence. Effects of magnitude stabilizers with respect to phase errors were simulated using Bloch simulation. Phantom study was conducted to compare the apparent diffusion coefficient (ADC) accuracy and geometric reliability, quantified using target registration error (TRE), with diffusion‐weighted single‐shot echo‐planar imaging (DW‐ssEPI). Six volunteers were recruited. DW‐ssEPI, DP‐bSSFP with and without ECG triggering, and DP‐MS‐bSSFP with and without ECG triggering were acquired 10 times with b = 500 s/mm2 in a single‐shot manner to evaluate magnitude variability. Diffusion trace images and diffusion tensor images were acquired using a 4‐shot DP‐MS‐bSSFP.

Results

Simulation showed that the DP‐MS‐bSSFP approach is insensitive to phase errors. The DP‐MS‐bSSFP approach had satisfactory ADC accuracy on the phantom with <5% difference with DW‐ssEPI. The mean/max TRE for DW‐ssEPI was 2.31/4.29 mm and was 0.51/1.20 mm for DP‐MS‐bSSFP. In the repeated single‐shot study, DP‐bSSFP without ECG triggering had severe signal void artifacts and exhibited a nonrepeatable pattern, which can be partially mitigated by ECG triggering. Adding the MS provided stable signal magnitude across all repetitions. High‐quality ADC maps and color‐coded fractional anisotropy maps were generated using the 4‐shot DP‐MS‐bSSFP. The mean/max TRE was 2.89/10.80 mm for DW‐ssEPI and 0.59/1.69 mm for DP‐MS‐bSSFP. Good agreements of white matter ADC, cerebrospinal fluid ADC, and white matter fractional anisotropy value were observed between DP‐MS‐bSSFP and DW‐ssEPI.

Conclusion

The proposed DP‐MS‐bSSFP approach provided high‐quality diffusion‐weighted and diffusion‐tensor images with minimal geometric distortion.
Collapse loads for rectangular foundations by three‐dimensional upper bound limit analysis using radial point interpolation method
Authors: Mohapatra Debasis , Kumar Jyant
Published: November 2018

A three‐dimensional kinematic limit analysis approach based on the radial point interpolation method (RPIM) has been used to compute collapse loads for rectangular foundations. The analysis is based on the Mohr‐Coulomb yield criterion and the associated flow rule. It is understood that the internal plastic power dissipation function and flow rule constraints can be expressed entirely in terms of plastic strain rates without involving stresses. The optimization problem has been solved on basis of the semidefinite programming (SDP) by using highly efficient primal‐dual interior point solver MOSEK in MATLAB. The results have been presented in terms of the variation of the shape factors with changes in the aspect ratio (L/B) of the footing for different values of soil internal friction angle (ϕ). Computations have revealed that the shape factors, sc and sq, due to effects of cohesion and surcharge increase continuously with (1) decrease in L/B and (2) increase in ϕ. On the other hand, the shape factor sγ, due to the effect of soil unit weight, increases very marginally with an increase in L/B up to (1) ϕ = 25° for a rough footing and (2) ϕ = 35° for a smooth footing. Thereafter, for greater values of ϕ, the variation of sγ with L/B has been found to be quite similar to that of the factors sc and sq. The variations of (1) nodal velocity patterns, (2) plastic power dissipation, and (3) maximum plastic shear strain rates have also been examined to interpret the associated failure mechanism.
Longitudinal assessment of cerebral perfusion and vascular response to hypoventilation in a bigenic mouse model of Alzheimer's disease with amyloid and tau pathology
Authors: Govaerts Kristof , Lechat Benoit , Struys Tom , Kremer Anna , Borghgraef Peter , Van Leuven Fred , Himmelreich Uwe , Dresselaers Tom
Published: November 2018

Alzheimer's disease is the most common neurodegenerative disease, and many patients also present with vascular dysfunction. In this study, we aimed to assess cerebral blood flow (CBF) and cerebrovascular response (CVR) as early, pre‐symptomatic (3 months of age), imaging markers in a bigenic model of Alzheimer's disease (APP.V717IxTau.P301L, biAT) and in the monogenic parental strains. We further developed our previously published combination of pulsed arterial spin labeling perfusion MRI and hypo‐ventilation paradigm, which allows weaning of the mice from the ventilator. Furthermore, the commonly used isoflurane anesthesia induces vasodilation and is thereby inherently a vascular challenge. We therefore assessed perfusion differences in the mouse models under free‐breathing isoflurane conditions. We report (i) that we can determine CBF and hypoventilation‐based CVR under ketamine/midazolam anesthesia and wean mice from the ventilator, making it a valuable tool for assessment of CBF and CVR in mice, (ii) that biAT mice exhibit lower cortical CBF than wild‐type mice at age 3 months, (iii) that CVR was increased in both biAT and APP.V717I mice but not in Tau.P301L mice, identifying the APP genotype as a strong influencer of brain CVR and (iv) that perfusion differences at baseline are masked by the widely used isoflurane anesthesia.
Medication administration in nursing homes: A qualitative study of the nurse role
Authors: Odberg Kristian Ringsby , Hansen Britt Sætre , Wangensteen Sigrid
Published: November 2018

Aims

The objective of this study was to expand the knowledge of the nurse role during medication administration in the context of nursing homes. The following research question guided the study: How can the nurse role during medication administration in nursing homes be described?

Design

A QUAL–qual mixed study design was applied.

Methods

Data were collected using partial participant observations and semi‐structured interviews of all staff members involved in medication administration. An inductive content analysis was performed.

Results

Medication administration is a pervasive process ingrained in the day‐to‐day activities of providing care to the patients. The nurse role is compensating, flexible and adaptable. There is a dynamic interaction between several contributory factors, those being shifting responsibility, a need for competence, invisible leadership, varying available competence, staff stability and vulnerable shifts.
Influence of zinc stannate and graphene hybrids on reducing the toxic gases and fire hazards during epoxy resin combustion
Authors: Sheng Haibo , Zhang Yan , Ma Chao , Yang Ling , Qiu Shuilai , Wang Bibo , Hu Yuan
Published: November 2018

Spinel zinc stannate (Zn2SnO4, ZS) was successfully synthesized by a simple hydrothermal route, and graphene(G) was used as the carrier to form graphene‐zinc stannate (G‐ZS) hybrids. The resulted G‐Zn2SnO4 (G‐ZS) was incorporated to epoxy resin for the purpose of reducing the toxicity hazards during combustion. Toxic gas analyzer results showed that the ZS hybrids possess high efficiency on reducing the generation of NOx, HCN, and CO. Cone calorimeter results of the G‐ZS/EP composites showed about 40% decrease on peak heat release rate compared with pristine EP which meant better fire performance. Also, TG‐IR technology was used to further investigate the gases release during the EP decomposition process. Particularly, the CO release had decreased about 80% than pure EP. This work constructs a new strategy to make a binary metal oxides system which would be efficient in reducing the toxic gases during polymer combustion. Besides, a proper bridge‐effect is proposed to illustrate the proper mechanism.
Study of phenyl‐terminated hyperbranched polyester as a special β‐nucleating agent on the toughness of isotactic polypropylene
Authors: Liu Jingru , Liang Hongwei , Li Chen , Hu Fangming
Published: November 2018

The effect of phenyl‐terminated hyperbranched polyester (HBP‐Bz) with different generation (the first generation and the fourth generation) as a special β‐nucleating agent on the toughness of isotactic polypropylene (iPP) was investigated by dynamic rheological measurements, scanning electron microscopy, differential scanning calorimetry, wide‐angle X‐ray diffraction, polarized optical microscopy, and mechanical properties measurements. The results show that the β nucleating activity of HBP‐Bz significantly depends on its concentration and molecular structure. The relative content of β‐crystal form (Kβ) increases with the increasing HBP‐Bz percentage reaches a maximum and then decreases as HBP‐Bz percentage further increases. The Kβ values of iPP/HBP‐G1‐1% and iPP/HBP‐G4‐1% blends are 26.52% and 20.80%, respectively. When compared with HBP‐G4, HBP‐G1 has incompact molecular structure, facilitating the π–π interaction between phenyl‐terminated groups and the helix chains of iPP crystallize on it, and therefore relatively good dispersibility, high β nucleating activity and excellent toughening effect are obtained. The impact strength of iPP was dramatically improved, especially with addition of 1 wt% HBP‐G1. POLYM. ENG. SCI., 59:E133–E143, 2019. © 2018 Society of Plastics Engineers
Study of the effect of different electron irradiation doses on the decomposition temperature of azodicarbonamide
Authors: Lopez‐Gonzalez Eduardo , Salmazo Leandra Oliveira , Lopez‐Gil Alberto , Rodriguez‐Perez Miguel A.
Published: November 2018

Azodicarbonamide (ADCA) is a well‐known chemical blowing agent used in the fabrication of polyolefin foams which decomposes into gases at temperatures above the melting temperature of the polymer. In these polymer foams, the polymer is usually crosslinked before or during the foaming process to increase its viscosity and make it capable of supporting the pressure of the gas during foaming. This crosslinking process allows producing low‐density foams with homogeneous cellular structures. A typical procedure to crosslink the polymer is to irradiate it using a high energy‐electron beam. When ADCA is incorporated into the polymer before the irradiation process, it is also exposed to the high energy electron beam. However, the effect of the irradiation on the decomposition process of ADCA has not been explored yet. In this research, it has been found that there is a reduction of the thermal decomposition temperature of ADCA when this material is electron irradiated with different doses ranging from 25 to 150 kGy, being this reduction higher when the irradiation dose is increased. It has also been found, that the reduction of the decomposition temperature is due to a modification of the lattice parameters of the crystalline structure of ADCA. POLYM. ENG. SCI., 59:791–798, 2019. © 2018 Society of Plastics Engineers
Carbon nanotube reinforced poly(trimethylene terephthalate) nanocomposites: Viscoelastic properties and chain confinement
Authors: Aswathi Madathinal Kunjappan , Padmanabhan Moothetty , Mathew Lovely , Saha Prosenjit , Terzano Roberto , Kalarikkal Nandakumar , Volova Tatiana , Thomas Sabu
Published: November 2018

Through a very facile route, a new class of nanocomposites involving poly(trimethylene terephthalate; PTT) and multiwalled carbon nanotubes (MWCNTs) was developed which was found to be high performance engineering material showing high modulus. Morphological, mechanical, viscoelastic, and thermal properties of the PTT nanocomposites with varying compositions of MWCNT were systematically studied and the results were analyzed. The dynamic mechanical and tensile properties of all the nanocomposites were seen to be enhanced with the addition of MWCNT and the sample containing 2 wt% MWCNT showing a storage modulus as much as 9.4 × 108 GPa. The results were correlated with the morphological features obtained from scanning electron microscopy and transmission electron microscopy. Coefficient of effectiveness, degree of entanglement density, and reinforcement efficiency factor were estimated from the storage modulus values and, in addition, the degree of chain confinement also could be quantified. Furthermore, theoretical modelling was also done on the elastic properties of the composites. The crystallization temperature, glass transition temperature, and percentage crystallinity were estimated for all the nanocomposites and it was found that the sample with 3 wt% MWCNT content exhibited the highest glass transition temperature of 68.2°C. POLYM. ENG. SCI., 59:E435–E445, 2019. © 2018 Society of Plastics Engineers
In‐Cell NMR Spectroscopy of Intrinsically Disordered Proteins
Authors: Sciolino Nicholas , Burz David S. , Shekhtman Alexander
Published: November 2018

This review summarizes the results of in‐cell Nuclear Magnetic Resonance, NMR, spectroscopic investigations of the eukaryotic and prokaryotic intrinsically disordered proteins, IDPs: α‐synuclein, prokaryotic ubiquitin‐like protein, Pup, tubulin‐related neuronal protein, Tau, phenylalanyl‐glycyl‐repeat‐rich nucleoporins, FG Nups, and the negative regulator of flagellin synthesis, FlgM. The results show that the cellular behavior of IDPs may differ significantly from that observed in the test tube.
Basicity‐dependent properties of anion conducting membranes consisting of iminium cations for alkaline fuel cells
Authors: Ko Beom‐Seok , Yoshimura Kimio , Warapon Sinananwanich , Shishitani Hideyuki , Yamaguchi Susumu , Tanaka Hirohisa , Maekawa Yasunari
Published: November 2018

To design novel anion‐conducting polymer electrolyte membranes (AEMs), this paper proposes a basicity index (BI) that is defined by the ion‐exchange ratios of AEMs from the OH− to Cl− forms in a neutral aqueous solution as a parameter for Arrhenius basicity (dissociation constant). Using a radiation‐induced graft polymerization technique, three iminium cations are introduced into fluorinated polymer films. The BI of the iminium‐containing AEMs is less than that of a conventional ammonium‐type AEM. The conductivity and water uptake correlate positively with the BI, whereas the thermal and chemical stabilities correlate negatively with the BI. The dependence on the BI stems from the stabilization of the iminium hydroxide in proportion to the basicity of the original diaza‐compounds, resulting in a decrease in conductivity and water uptake with keeping higher thermal and chemical stabilities. Notably, ion conductivity is sufficient and water uptake is less in AEMs with a medium BI. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 503–510
A comparison of biological activity of commercially available purified native botulinum neurotoxin serotypes A1 to F1 in vitro, ex vivo, and in vivo
Authors: Donald Sarah , Elliott Mark , Gray Bryony , Hornby Fraser , Lewandowska Agnieszka , Marlin Sandra , Favre‐Guilmard Christine , Périer Cindy , Cornet Sylvie , Kalinichev Mikhail , Krupp Johannes , Fonfria Elena
Published: November 2018

Botulinum neurotoxin (BoNT) is a major therapeutic agent. Of seven native BoNT serotypes (A to G), only A and B are currently used in the clinic. Here we compared the potency of commercially available purified native serotypes A1 to F1 across in vitro, ex vivo, and in vivo assays. BoNT potency in vitro was assessed in rat primary cells (target protein cleavage and neurotransmitter release assays) in supraspinal, spinal, and sensory systems. BoNT potency ex vivo was measured in the mouse phrenic nerve hemidiaphragm (PNHD) assay, measuring muscle contractility. In vivo, BoNT‐induced muscle relaxation in mice and rats was assessed in the Digit Abduction Score (DAS) test, while effects on body weight (BW) gain were used to assess tolerability. In all assays, all BoNT serotypes were potent toxins, except serotype D1 in vivo which failed to produce significant muscle flaccidity in mice and rats. In rats, all serotypes were well‐tolerated, whereas in mice, reductions in BW were detected at high doses. Serotype A1 was the most potent serotype across in vitro, ex vivo, and in vivo assays. The rank order of potency of the serotypes revealed differences among assays. For example, species‐specificity was seen for serotype B1, and to a lesser extent for serotype C1. Serotypes F1 and C1, not currently in the clinic, showed preference for sensory over motor models and therefore could be considered for development in conditions involving the somatosensory system.
Where science, technology, engineering, and mathematics (STEM) graduates move: Human capital, employment patterns, and interstate migration in the United States
Authors: Wright Richard , Ellis Mark
Published: November 2018

This research investigates the interstate migration of workers in the United States who have earned an undergraduate STEM (science, technology, engineering, and mathematics) degree compared with those who have not. We build on previous studies that (a) classified “skilled” workers as having earned an undergraduate degree (b) used net migration gain or loss as a yardstick of relative destination attraction, and (c) advanced the idea that physical amenities play an outsized role in labour market preferences for skilled workers. We calibrate the attractivity of states for three levels of human capital and then evaluate these assessments of relative attractivity to show that workers with different types of human capital respond to different labour market signals in contradictory ways. Amenity, measured by heating degree days, has little to do with the state‐to‐state migration of workers who have a STEM degree, yet helps explain the migration patterns of workers with no undergraduate degree. Employment growth in a state influences migration for degreed workers in the recessionary years but not in the period of recovery. The opposite holds for workers without a degree. States with high percentages of any type of degreed workers attract both STEM and non‐STEM degreed migrants but not those without a degree. States with a large share of STEM degreed workers in their degreed workforce are especially attractive for STEM degreed migrants. The conclusions discuss what the findings imply about diverging access to labour market opportunity by human capital and state higher education policy.
How confident are predictability estimates of the winter North Atlantic Oscillation?
Authors: Weisheimer Antje , Decremer Damien , MacLeod David , O'Reilly Christopher , Stockdale Tim N. , Johnson Stephanie , Palmer Tim N.
Published: November 2018

Atmospheric seasonal predictability in winter over the Euro‐Atlantic region is studied with an emphasis on the signal‐to‐noise paradox of the North Atlantic Oscillation. Seasonal hindcasts of the ECMWF model for the recent period 1981–2009 show, in agreement with other studies, that correlation skill over Greenland and parts of the Arctic is higher than the signal‐to‐noise ratio implies. This leads to the paradoxical situation where the real world appears more predictable than the models suggest, with the forecast ensembles being overly dispersive (or underconfident). However, it is demonstrated that these conclusions are not supported by the diagnosed relationship between ensemble mean root‐mean‐square error (RMSE) and ensemble spread which indicates a slight under‐dispersion (overconfidence). Furthermore, long atmospheric seasonal hindcasts suggest that over the 110‐year period from 1900 to 2009 the ensemble system is well calibrated (neither over‐ nor under‐dispersive). The observed skill changed drastically in the middle of the twentieth century and paradoxical regions during more recent hindcast periods were strongly under‐dispersive during mid‐century decades.

Due to non‐stationarities of the climate system in the form of decadal variability, relatively short hindcasts are not sufficiently representative of longer‐term behaviour. In addition, small hindcast sample size can lead to skill estimates, in particular of correlation measures, that are not robust. It is shown that the relative uncertainty due to small hindcast sample size is often larger for correlation‐based than for RMSE‐based diagnostics. Correlation‐based measures like the RPC are shown to be highly sensitive to the strength of the predictable signal, implying that disentangling of physical deficiencies in the models on the one hand, and the effects of sampling uncertainty on the other hand, is difficult. Given the current lack of a causal physical mechanism to unravel the puzzle, our hypotheses of non‐stationarity and sampling uncertainty provide simple yet plausible explanations for the paradox.
Carbon and oxygen isotopic analyses of calcite in calcite–dolomite mixtures: Optimization of selective acid extraction
Authors: Liu Xi , Deng Wenfeng , Wei Gangjian
Published: November 2018

Rationale

Carbon and oxygen isotopic compositions of individual minerals in calcite–dolomite mixtures could be measured using a selective acid extraction technique based on the different reaction rates of calcite and dolomite with phosphoric acid. However, poor accuracies of calcite are usually obtained when mixtures of low calcite content are analyzed, which may result in incorrect conclusions. To overcome this shortcoming, improvements are needed in accuracy and precision when using the technique with mixtures of low calcite content.

Methods

Calcite and dolomite were analyzed under different reaction conditions using a GV Isoprime™ II isotope ratio mass spectrometer equipped with a dual inlet (DI) and an automatic sampler, to study the relationships between isotopic compositions and CO2 yield, and reaction time and temperature. Artificial mixtures with varied calcite:dolomite ratios were prepared, and their calcite isotopic compositions were determined with the aim of optimizing analytical conditions.

Results

The CO2 yields and isotopic compositions of calcite and dolomite were obtained on‐line under different experimental conditions using DI‐isotope ratio mass spectrometry (DI‐IRMS). Based on the analysis results of artificial mixtures, the reaction conditions for analyzing isotopic composition of calcite in mixtures were optimized as follows. Samples should have grain sizes of 75–80 μm; and samples with calcite contents of >50%, 30–50% and < 30% should be reacted with acid for 10–15 min at 50°C, 6 min at 50°C and 45 min at 25°C, respectively.

Conclusions

Optimized analytical conditions are suggested for the determination of the isotopic compositions of calcite in mixtures with improved accuracy by an automatic selective acid extraction technique.
Porous diaphragm syndrome with recurrent thymoma
Authors: Ota Takayo , Hasegawa Yoshikazu , Okabe Takafumi , Okimura Akira , Fukuoka Masahiro
Published: November 2018

Porous diaphragm syndrome describes a defect in the diaphragm in which substances pass from the peritoneal cavity to the pleural space. Defects may be congenital or acquired. Acquired defects are caused by the thinning and eventual splitting of collagen fibres in the tendinous part of the diaphragm. We report a case of porous diaphragm syndrome with recurrent thymoma that presented with massive ascites. Increasing intra‐abdominal pressure by ascites and diaphragmatic thinning due to malnutrition by malignancies resulted in the formation of an artificial hole. Thoracentesis changed the balance of hydrostatic pressure, which initiated the influx of a large volume of ascites to the pleural cavity through a hole in the diaphragm.
Secondary students’ proof constructions in mathematics: The role of written versus oral mode of argument representation
Authors: Stylianides Andreas J.
Published: November 2018

Prior research showed that many secondary students fail to construct arguments that meet the standard of proof in mathematics. However, this research tended to use survey methods and only consider students presenting their perceived proofs in written form. The limited use of observation methods and the lack of consideration of students presenting their perceived proofs orally—in tandem with their written proofs for the same claims—might have resulted in a skewed picture of the potential of students’ constructed proofs, and this raises concern about the validity of research findings. The research reported in this article substantiates this concern. Using data from a design experiment in two secondary mathematics classrooms (14–15‐year‐olds), I explored the role of the written versus the oral mode of argument representation in students’ proof constructions. Findings from the comparison between the written arguments (perceived proofs) that the students produced during small group work and the oral arguments that the students presented in front of the class for the same claims showed that the oral mode of representation is more likely than the written mode to be associated with the construction of arguments that meet the standard of proof. Thus if a study had analysed students’ written arguments only (as in survey research), it would have reported a less favourable picture of the potential of students’ constructed proofs than another study that would focus only on students’ oral arguments (as in observational research). Implications for methodology, research and practice are discussed in light of these findings.
Concentration of stromal cell‐derived factor‐1 (SDF‐1/CXCL12) in the follicular fluid is associated with blastocyst development
Authors: Nishigaki Akemi , Tsuzuki‐Nakao Tomoko , Kido Takeharu , Kida Naoko , Kakita‐Kobayashi Maiko , Murata Hiromi , Okada Hidetaka
Published: November 2018

Purpose

To study the association between stromal cell‐derived factor‐1 (SDF‐1/CXCL12) and vascular endothelial growth factor (VEGF) concentrations in individual human ovarian follicles and IVF outcomes.

Methods

Concentrations of SDF‐1 and VEGF in 261 follicular fluid samples were measured with enzyme‐linked immunosorbent assay. IVF outcome parameters were included in fertilization rate, cleavage rate, embryo morphology on day 3, and blastocyst morphology on day 5.

Results

The follicular concentration of SDF‐1 and VEGF was not significantly associated with fertilization and cleavage outcome, and embryo morphology. The rates of full blastocysts and good‐quality blastocysts were significantly higher in follicles with an SDF‐1 concentration of 275‐350 pg/mL than in the follicles with SDF‐1 concentrations of <200 and ≥350 pg/mL (P < 0.05). The follicular concentration of VEGF was not associated with the blastocyst morphology.

Conclusion

Our findings showed that follicular concentration of SDF‐1, and not VEGF, may be a valuable biochemical marker of blastocyst development.
Rely on collaborative, proactive approach to managing conflict on campus
Authors: McCarthy Claudine
Published: November 2018

Student conduct offices often struggle with the perception of being solely reactionary and nothing more.
Statistical methodology for constructing gestational age‐related charts using cross‐sectional and longitudinal data: The INTERGROWTH‐21stproject as a case study
Authors: Ohuma Eric O. , Altman Douglas G. ,   for the International Fetal and Newborn Growth Consortium for the 21 Century (INTERGROWTH‐21 Project)
Published: November 2018

Most studies aiming to construct reference or standard charts use a cross‐sectional design, collecting one measurement per participant. Reference or standard charts can also be constructed using a longitudinal design, collecting multiple measurements per participant. The choice of appropriate statistical methodology is important as inaccurate centiles resulting from inferior methods can lead to incorrect judgements about fetal or newborn size, resulting in suboptimal clinical care.

Reference or standard centiles should ideally provide the best fit to the data, change smoothly with age (eg, gestational age), use as simple a statistical model as possible without compromising model fit, and allow the computation of Z‐scores from centiles to simplify assessment of individuals and enable comparison with different populations. Significance testing and goodness‐of‐fit statistics are usually used to discriminate between models. However, these methods tend not to be useful when examining large data sets as very small differences are statistically significant even if the models are indistinguishable on actual centile plots. Choosing the best model from amongst many is therefore not trivial. Model choice should not be based on statistical considerations (or tests) alone as sometimes the best model may not necessarily offer the best fit to the raw data across gestational age. In this paper, we describe the most commonly applied methodologies available for the construction of age‐specific reference or standard centiles for cross‐sectional and longitudinal data: Fractional polynomial regression, LMS, LMST, LMSP, and multilevel regression methods. For illustration, we used data from the INTERGROWTH‐21stProject, ie, newborn weight (cross‐sectional) and fetal head circumference (longitudinal) data as examples.
Modifying Properties of Aqueous Micellar Solutions by External Additives: Deep Eutectic Solvent versus Its Constituents
Authors: Pal Mahi , Behera Kamalakanta , Yadav Anita , Pandey Siddharth
Published: November 2018

Deep eutectic solvents (DESs) have emerged as nontoxic and inexpensive alternatives to both ionic liquids and common volatile organic solvents. Role of DESs in sustaining and effecting surfactant self‐assemblies has garnered interest only recently. Effect of addition of DESs Reline and Glyceline, constituted of salt choline chloride (ChCl) and different H‐bond donors (HBDs) urea and glycerol, respectively, in 1 : 2 mole ratios, on the physicochemical properties of four structurally‐different aqueous micellar solutions of anionic sodium dodecylsulfate (SDS), cationic dodecyltrimethylammonium bromide (DTAB), zwitterionic dodecyl sulfobetaine (SB‐12) and nonionic Triton X‐100 (TX‐100) is assessed. It is observed that the changes in the properties investigated are contingent, in most part, on the structure of the surfactant as well as on the identity of the DES. Properties of the anionic SDS micellar solutions are affected the most by the addition of the DESs. The change in the properties of an aqueous micellar solution due to the addition of a DES may not always be a result of the cumulative change due to the addition of the constituents of the DES. In general, the salt ChCl of the DESs is found to dominate the changes as compared to the HBDs urea/glycerol. Overall, DESs emerge as substances having potential to favorably modify the key properties of micellar media.
Binary and Ternary Manganese Dioxide Composites Cathode for Aqueous Zinc‐ion Battery
Authors: Zhao Ling , Dong Liubing , Liu Wenbao , Xu Chengjun
Published: November 2018

MnO2 is a traditional cathode material for aqueous zinc‐ion battery (ZIB). However, its extensive use is limited by its poor conductivity and cycling performance. Design of binary or ternary MnO2 composites is a useful way to enhance the performance of MnO2. At first, a series of binary MnO2/carbon nanotube (CNT) composites with different CNT contents were synthesized by a facile co‐precipitation method. The effect of CNT content on the properties of binary composites was investigated. In addition, the ternary MnO2/CNT/polyaniline (PANI) composites were prepared to investigate the effect of unitary, binary and ternary composites on the MnO2. The results show that an appropriate content of CNT decreases the charge transfer resistance of the composite leading to a good electrochemical performance. The addition of PANI stabilizes the cycle performance of the composite at a cost of a slight decrease in the specific capacity.
Fabrication of Bimetallic Ag‐Co Nanoparticle Deposited on Hierarchical ZSM‐5 as a Selective Catalyst for Synthesis of Propargylamine in Water via Multicomponent A3 Coupling
Authors: Kalbasi Roozbeh Javad , Khojastegi Anahita
Published: November 2018

Alloying nanoparticle is a method to adjust the surface properties of catalysts so as to enhance catalytic performances of them and they usually exhibit outstanding characteristics which are disparate from monometallic nanoparticles. In this regard, a bimetallic catalyst based on sliver and cobalt nanoparticles incorporated in the structure of hierarchical ZSM‐5 (Hi‐ZSM‐5) was produced. This novel catalyst was simply produced through simultaneous chemical reduction of silver and cobalt ions in the presence of Hi‐ZSM‐5. The solid support (Hi‐ZSM‐5) has played a highly crucial part in this catalyst because it offers a high surface area for deposition of nanoparticles as active sites and facilitates diffusion of reactants by its mesopores. The catalytic aspects of Ag−Co/Hi‐ZSM‐5 were examined in A3 coupling reaction of amine, aldehyde, acetylene in water media and impacts of different reaction parameters were extensively investigated. Outperforming both monometallic counterparts, the catalyst was found highly selective, stable and recoverable in the reaction and it did not show any sign of chemical or morphological alterations after 5 runs. The chemical composition and morphological properties of the catalyst were evaluated by XRD, BET, SEM‐EDS, TEM, DRS‐UV and ICP‐AES techniques.
A gateway to consumers' minds: Achievements, caveats, and prospects of electroencephalography‐based prediction in neuromarketing
Authors: Hakim Adam , Levy Dino J.
Published: November 2018

In the last decade, the field of consumer neuroscience, or neuromarketing, has been flourishing, with numerous publications, academic programs, initiatives, and companies. The demand for objective neural measures to quantify consumers' preferences and predict responses to marketing campaigns is ever on the rise, particularly due to the limitations of traditional marketing techniques, such as questionnaires, focus groups, and interviews. However, research has yet to converge on a unified methodology or conclusive results that can be applied in the industry. In this review, we present the potential of electroencephalography (EEG)‐based preference prediction. We summarize previous EEG research and propose features which have shown promise in capturing the consumers' evaluation process, including components acquired from an event‐related potential design, inter‐subject correlations, hemispheric asymmetry, and various spectral band powers. Next, we review the latest findings on attempts to predict preferences based on various features of the EEG signal. Finally, we conclude with several recommended guidelines for prediction. Chiefly, we stress the need to demonstrate that neural measures contribute to preference prediction beyond what traditional measures already provide. Second, prediction studies in neuromarketing should adopt the standard practices and methodology used in data science and prediction modeling that is common in other fields such as computer science and engineering.

This article is categorized under:

Economics > Interactive Decision‐Making

Economics > Individual Decision‐Making

Psychology > Prediction

Neuroscience > Cognition
Developing Metrics to Define Progress in Children’s Surgery
Authors: Poenaru Dan , Seyi‐Olajide Justina Onyioza
Published: November 2018

There is a need for relevant, valid, and practical metrics to better quantify both need and progress in global pediatric surgery and for monitoring systems performance. There are several existing surgical metrics in use, including disability‐adjusted life years (DALYs), surgical backlog, effective coverage, cost‐effectiveness, and the Lancet Commission on Global Surgery indicators. Most of these have, however, not been yet applied to children’s surgery, leaving therefore significant data gaps in the burden of disease, infrastructure, human resources, and quality of care assessments in the specialty. This chapter reviews existing global surgical metrics, identifies settings where these have been already applied to children’s surgery, and highlights opportunities for further inquiry in filling the knowledge gaps. Directing focused, intentional knowledge translation efforts in the identified areas of deficiency will foster the maturation of global pediatric surgery into a solid academic discipline able to contribute directly to the cause of improving the lives of children around the world.
Cytogenetic Analysis of Spontaneous Miscarriages Using Long-Term Culturing of Chorionic Villi
Authors: Horiuchi Isao , Wakimoto Yu , Kuwata Tomoyuki , Sawai Hideaki , Shibahara Hiroaki , Takagi Kenjiro
Published: November 2018

Spontaneous miscarriages are strongly associated with fetal chromosomal abnormalities. We sought to validate the occurrence of chromosomal abnormalities in Japanese patients with early spontaneous miscarriages using a conventional long-term culture method. One hundred and thirty-two patients were studied after excluding 7 cases with culture failure. Chromosomal analysis of 132 cases was performed using a long-term culture method of the villous placental tissue. Patients’ age, number of previous spontaneous abortions, fetal data from ultrasonography, and the method of conception (ART or spontaneous pregnancy) were obtained from the electronic medical records. The association between the patient’s background and the cytogenetic data was analyzed using a Chi squared test. The average maternal age of the 132 cases of early spontaneous abortion was 34.2≤±≤4.7 year (range: 24–43). Chromosomal abnormalities were detected in 89 cases (67.4%), among which 52.8% represented trisomy, 1.1% represented double trisomy, 10.1% represented polyploidy, 7.9% represented monosomy, 12.4% represented structural chromosomal abnormality, and 15.7% represented mosaic chromosome abnormalities. Women older than 35 year had a higher rate of chromosomal abnormalities than younger women (76.6% vs. 58.8%; P≤=≤0.015). Twenty-five of the 132 pregnancies were achieved with ART and were associated with a higher rate of trisomy (64.0% vs. 37.4%; P≤=≤0.008). G-banding identified a rare form of polyploidy 94,XXYYYY. Our results confirmed previous findings that older Japanese women with spontaneous miscarriages have a higher rate of chromosomal abnormalities.
Regenerative processes for Poisson zero polytopes
Authors: Martínez Servet , Nagel Werner
Published: November 2018

Let (Mt:t>0) be a Markov process of tessellations of ℝℓ, and let (𝒞t:t>0) be the process of their zero cells (zero polytopes), which has the same distribution as the corresponding process for Poisson hyperplane tessellations. In the present paper we describe the stationary zero cell process (at𝒞at:t∈ℝ),a>1, in terms of some regenerative structure and we show that it is a Bernoulli flow. An important application is to STIT tessellation processes.
Limit theorems for random polytopes with vertices on convex surfaces
Authors: Turchi N. , Wespi F.
Published: November 2018

We consider the random polytope Kn, defined as the convex hull of n points chosen independently and uniformly at random on the boundary of a smooth convex body in ℝd. We present both lower and upper variance bounds, a strong law of large numbers, and a central limit theorem for the intrinsic volumes of Kn. A normal approximation bound from Stein's method and estimates for surface bodies are among the tools involved.
III. A Eucharistically Malnourished Baptist's Desire for Intercommunion
Authors: Harmon Steven R.
Published: November 2018

While I am not claiming credit for this year's panel session devoted to the question of intercommunion in the context of College Theology Society's convention with Baptist participation, I am deeply gratified that we as the church's theologians, Baptist and Catholic, are now raising the question in this manner, and that Professor Freeman has made clear for us what the ground rules seem to be for playing the hypothetical game of Baptist-Catholic intercommunion at a CTS convention. I have nothing to add to his spot-on summary of the Baptist “rules” for open communion and the Catholic “rules” for exceptional intercommunion articulated in the documents he has cited.
“Doing CRISPR”
Authors: Dankel Dorothy Jane
Published: November 2018

Salmon farming is a key industry in Norway, with firsthand value of more than 60 billion Norwegian crowns in 2017. The salmon industry is a driving force for biotechnological applications in the marine sector. The recent release of the Atlantic salmon reference genome offers new opportunities to solve major aquaculture bottlenecks that currently limit expansion of the industry. One major bottleneck is the genetic impact of escaped farmed salmon on wild populations. To solve this problem, the industry can use sterile salmon in production. As shown by Wargelius et al., sterile salmon can be made by preventing the formation of germ cells through genome editing using the CRISPR-Cas9 method. This approach solves problems of genetic introgression and precocious maturation. However, genome editing of animals, especially for human consumption, raises ethical as well as safety and legal questions. These social and ethical aspects can have tremendous impact in analyzing the final result of salmon farming (e.g., consumer acceptability of a fresh or frozen filet or similar salmon product) but also can be examined “upstream” by describing and assessing the research communities that promote and carry out the science that underpins the salmon industry. Who produces the scientific “facts” that govern the Norwegian aquaculture industry? How do these scientific communities work together? What are the societal impacts of this science? This article uses ethnographical observation and interviews to describe the state-of-the-art of CRISPR gene-editing procedures currently employed in the science and industry collaboration in Norway.
The palaeoecological meaning of macromammal remains from archaeological sites exemplified by the case study of Grotta Paglicci (Upper Palaeolithic, southern Italy)
Authors: Boschin Francesco , Boscato Paolo , Berto Claudio , Crezzini Jacopo , Ronchitelli Annamaria
Published: November 2018

Bone accumulation in Palaeolithic archaeological sites is often the result of activities carried out by hunter-gatherer groups. Cultural choices may have influenced prey representation in archaeological assemblages, distorting their palaeoecological meaning. We present a comparison between large mammal and small mammal assemblages from the Upper Palaeolithic sequence of Grotta Paglicci (Apulia, southern Italy) that extends from the Marginally Backed Bladelet Aurignacian (about 39,000 cal yr BP) to the Final Epigravettian (about 13,000 cal yr BP). At Paglicci, the high frequency of horse and ibex remains indicates open and dry environments for most of the Upper Palaeolithic. This is confirmed by the predominance of the common vole among small mammals. The alternation between horse and ibex, which takes place during the Upper Palaeolithic, however, looks to be more related to variations in hunting territories. Taxon frequencies change abruptly at 17,955–16,696 cal yr BP, with an increase in woodland-related ungulates together with micromammals, indicating a climatic evolution towards milder and more humid conditions. Results demonstrate that when the association of ungulate taxa is considered as a whole, it has a good palaeoecological signal, whilst considering taxa separately can help to better understand cultural choices of past hunter-gatherer communities.
Host-plant switching promotes the population growth ofApolygus lucorum: implications for laboratory rearing
Authors: Pan H.-S. , Liu B. , Lu Y.-H.
Published: November 2018

The mirid bugApolygus lucorum(Meyer-Dür) (Hemiptera: Miridae) is a major pest on cotton, fruit trees and other crops in China.A. lucorumadults often switch host plants in the agro-ecosystem, and such host-plant switching may promote more rapid population growth ofA. lucorum. Here, we examined the population fitness ofA. lucorumon different combinations of two plant foods [fresh maize kernels (Zea mays) and green bean pods (Phaseolus vulgaris)] in the laboratory when reared either individually or in groups. Our results suggested that, compared withA. lucorumnymphs reared on green bean alone, the survival rate, developmental rate, and adult weight significantly increased when they were fed fresh maize kernels for both rearing methods. Both two-plant combinations of foods (i.e., maize as nymphal food then green bean as adult food, and green bean as nymphal food then maize as adult food) generally prolonged adult longevity, improved female fecundity, and higher egg hatching rate compared with maize or green bean as food for both nymphs and adults. The combination of nymphs with maize and adults with green bean showed the highest population growth rate for both individual and group rearing of mirid bugs. Host food switching greatly promoted the population growth ofA. lucorum, and suggests a new diet for laboratory rearing ofA. lucorum.