bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultrahigh-vacuum organic molecular-beam deposition system for in situ growth and characterization
Authors: Annese Emilia , dos Santos Joacir E. , Rodrigues Gustavo Lorencini M. P. , Rocha Andre Silva , de Moraes Horacio Ribeiro , Cezar Julio Criginski
Published: September 2018

A compact ultrahigh-vacuum molecular-beam deposition system has been developed for the in situ synthesis of organic thin films and multilayers. The system incorporates all the features (heater, thickness monitor, evaporators) necessary for controlled organic thin-film growth. It can be used independently, or it can be docked to the in situ growth system and transferred to other instruments of the PGM beamline, thus allowing extensive film preparation and characterization. A manipulator dedicated to specimen preparation and organic-film deposition with temperature control between 200 K and ∼800 K has been developed. The design and performance of the system are reported with emphasis on a novel solution of masks developed to achieve position-dependent film deposition. To demonstrate the enhanced capabilities of the PGM beamline in the growth and in the characterization of electronic-structure studies of organic molecular films and their heterostructures through synchrotron-based spectroscopies, this paper presents some preliminary results of a study of Fe-phthalocyanine growth on Si substrates and on in situ prepared La0.67Sr0.33MnO3 buffer layers on SrTiO3 single crystal.
Cyclic high temperature corrosion studies of carbon nanotubes-Cr2O3 composite coatings on boiler steel at 900°C in molten salt environment
Authors: Goyal Khushdeep , Singh Hazoor , Bhatia Rakesh
Published: September 2018

Purpose

Molten sulphate-vanadate induced hot corrosion is the main reason of failure of boiler tubes used at high temperatures in thermal power plants. The hot corrosion can be encountered by applying thermal spray coatings on the alloy steels. In this perspective, this paper aims to attempt to investigate the effect of carbon nanotubes reinforcement on Cr2O3 composite coatings on hot corrosion behaviour of ASTM-SA213-T22 steel in a corrosive environment of Na2SO4 – 60%V2O5 at 900°C for 50 cycles.

Design/methodology/approach

The coatings have been deposited with high velocity oxy fuel process. The samples were exposed to hot corrosion in a Silicon tube furnace at 900°C for 50 cycles. The kinetics of corrosion behaviour were analysed by the weight gain measurements after each cycle. Corrosion products were analysed with X-ray diffraction, scanning electron microscopy, energy dispersive and cross-sectional analysis techniques.

Findings

During investigations, the carbon nanotubes (CNT) reinforced Cr2O3 composite coatings on T22 steel were found to provide better corrosion resistance in the molten salt environment at 900°C. The coatings showed lower weight gain along with formation of protective oxide scales during the experiment. Improvement in protection against hot corrosion was observed with increase in CNT content in the coating matrix.

Research limitations/implications

The addition of CNT has resulted in reduction in porosity by filling the voids in chromium oxide coating, with interlocking of particle and has blocked the penetration of corroding species to enhance the corrosion resistance of the composite coatings. The corrosion rate was found to be decreasing with increase in CNT content in coating matrix.

Originality/value

It must be mentioned here that high temperature corrosion behaviour of thermally sprayed CNT-Cr2O3 composite coatings has never been studied, and it is not available in the literature. Hence, present investigation can provide valuable information for application of CNT-reinforced coatings in high temperature fuel combustion environments.
The effect of audit committee effectiveness and audit quality on corporate voluntary disclosure quality
Authors: Agyei-Mensah Ben Kwame
Published: September 2018

Purpose

The purpose of this paper is to examine the linkages between audit committees’ (AC) effectiveness, audit quality and corporate voluntary disclosure quality (VDQ).

Design/methodology/approach

Empirical tests address 144 firm-year observations drawn from Ghanaian listed companies during 2013–2016.

Findings

The results document a substitute and complementary effect between the presence of Big Four auditor and effective AC in increasing quality voluntary disclosure.

Originality/value

This study is one of the few that have examined the effect of AC effectiveness and audit quality on corporate VDQ. The findings lend credence to the belief that AC effectiveness and Big Four auditors complement each other to enhance quality of voluntary information disclosure.
The academic performance of primary school students from rural China
Authors: Liu Hongyan , Xue Hao , Shi Yaojiang , Rozelle Scott
Published: September 2018

Purpose

Low levels of human capital in rural China are rooted in the poor schooling outcomes of elementary school students. The purpose of this paper is to provide insight into the distribution of academic performance in rural China and identify vulnerable groups.

Design/methodology/approach

The authors draw on a data set of 25,892 observations constructed from 11 school-level surveys spanning nine provinces and one municipality in China conducted from 2013 to 2015.

Findings

The authors find that the distribution of academic performance is uneven across provinces and subgroups. In general, male students, Han, living in richer counties, living with their parents and studying in rural public schools do better academically than female students, non-Han, living in poorer counties, left behind and studying in private migrant schools in cities.

Research limitations/implications

Using the results of this study, policymakers should be able to better target investments into rural education focusing on at risk subpopulations.

Originality/value

With limited data sources, the research on the academic performance of students in rural China is largely absent. The findings of this study help to fill the gaps in the literature base.
Diagnosis of rotor broken bars faults in squirrel cage induction motor using continuous wavelet transform
Authors: Abdi Monfared Omid , Doroudi Aref , Darvishi Amin
Published: September 2018

Purpose

Squirrel cage induction motors suffer from several faults such as rotor broken bar. One of the powerful methods to detect induction motor faults is the line current signature analysis. This paper aims to present a novel algorithm based on continuous wavelet transform (CWT) to diagnose a rotor broken bar fault.

Design/methodology/approach

The proposed CWT has high flexibility in monitoring any frequency of interest in a waveform. Based on this transform, stator current frequency spectrum is analyzed to diagnose the rotor broken bar fault. The algorithm distinguishes the healthy motor from the faulted one based on a proper index. The method can be used in steady-state running time of induction motor and under different loading conditions. Experimental results are presented to show the validity of the proposed approach.

Findings

The proposed index considerably increases at the broken bars conditions compared to the healthy conditions. It can clearly diagnose the faulty conditions. The experimental results are found to be in good agreement with the theoretical and simulated results. The proposed method can reduce the noise and spectral leakage effects.

Originality/value

The main contribution of the paper are as follows: using CWT for detection of broken bar faults; introducing a proper index for diagnosing broken bars; and introducing a supplementary index to reduce the noise and spectral leakage effects.
Aditya Birla Money: developing options of investment strategy
Authors: Keshari Jena Sangram , Dash Ashutosh
Published: September 2018

Subject area

Financial derivative and risk management.

Study level/applicability

The case is intended to be used for MBA and BBA programs in the elective courses such as derivatives and risk management, financial engineering, financial risk management and portfolio management, and for executives aspiring for the fund manager position in industry. The case could also be used in management development programs on financial risk management.

Case overview

The case was based on the real life experience of a portfolio manager who was entrusted with the responsibility of maximizing return of the portfolio. With the backdrop of dismal performance of the portfolio, the portfolio manager is looking for opportunity in the context of declaration of result by Infosys Ltd, one of the constituents of the portfolio. So the team headed by Nirakar Chaulia was thinking of development and application of option strategies to exploit the result day (i.e. January 14, 2016) opportunity to improve the performance of the portfolio and also reduce the potential of stock price risk. Moreover, the case was designed to help the students develop and assess different option strategies based on their market intuitions. Also, students would be able to apply the option contracts for managing price risk associated with the underlying asset.

Expected learning outcomes

The case would prepare students to develop different strategies to be exploited in different market conditions and assess their performance. Especially, this case was designed to enable the students to understand options as a special kind of derivative in terms of trading and its payoff, how to initiate directional and volatility trading with options, how to apply options to generate income to enhance the portfolio performance and how to develop option strategies for different market conditions and assess their performance.

Supplementary materials

Teaching note is available for instructors only.

Subject code

CSS 1: Accounting and Finance.
Organizational emphasis on inclusion as a cultural value and third-party response to sexual harassment
Authors: Collazo Jr José Luis , Kmec Julie A.
Published: September 2018

Purpose

Reliance on third-party judgments are common in efforts to identify and reduce workplace sexual harassment (SH). The purpose of this paper is to identify whether a workplace emphasis on inclusion as a cultural value is related to third-party labeling of and response to an exchange between a male manager and his female subordinate.

Design/methodology/approach

Participants (n=308) in an online survey experiment were randomly assigned to a workplace that emphasized inclusion or one that emphasized individual achievement as a cultural value. They read a vignette describing a workplace interaction between a male manager and his female subordinate and responded to a series of questions.

Findings

Organizational emphasis on inclusion is unrelated to third-party labeling of the interaction as SH, but positively associated with labeling the female’s intention to pursue harassment charges as an overreaction, and support for the female subordinate in a claim of SH against her manager. Culture is unassociated with willingness to defend the male manager in a SH claim.

Practical implications

Identifying how workplace culture shapes third-party reaction to harassment can help employers use third-party witnesses and cultural value statements as tools to reduce SH.

Social implications

A workplace’s cultural emphasis on inclusion is positively related to third-party support for SH victims implying the importance of workplace context in the fight against workplace SH.

Originality/value

The paper presents the first experimental analysis of how a workplace cultural emphasis on inclusion affects the third-party observers’ reactions to SH.
Big Data analytics for prediction: parallel processing of the big learning base with the possibility of improving the final result of the prediction
Authors: Djafri Laouni , Amar Bensaber Djamel , Adjoudj Reda
Published: September 2018

Purpose

This paper aims to solve the problems of big data analytics for prediction including volume, veracity and velocity by improving the prediction result to an acceptable level and in the shortest possible time.

Design/methodology/approach

This paper is divided into two parts. The first one is to improve the result of the prediction. In this part, two ideas are proposed: the double pruning enhanced random forest algorithm and extracting a shared learning base from the stratified random sampling method to obtain a representative learning base of all original data. The second part proposes to design a distributed architecture supported by new technologies solutions, which in turn works in a coherent and efficient way with the sampling strategy under the supervision of the Map-Reduce algorithm.

Findings

The representative learning base obtained by the integration of two learning bases, the partial base and the shared base, presents an excellent representation of the original data set and gives very good results of the Big Data predictive analytics. Furthermore, these results were supported by the improved random forests supervised learning method, which played a key role in this context.

Originality/value

All companies are concerned, especially those with large amounts of information and want to screen them to improve their knowledge for the customer and optimize their campaigns.
Exploring the benefits and challenges of learning analytics in higher education institutions: a systematic literature review
Authors: El Alfy Shahira , Marx Gómez Jorge , Dani Anita
Published: September 2018

Purpose

The potential capabilities and benefits that learning analytics can provide are not fully utilized. A current stream of research suggests that learning analytics has more to offer for continuous improvement of higher education institutions. This study aims to explore the opportunities that data analytics stand to offer higher education and the challenges that plays down its role, adoption and usage in different areas of higher education institutions.

Design/methodology/approach

This study adopts a systematic literature review approach in answering the research questions. The critical role of learning analytics and the exploratory nature of research questions justify the use of systematic literature review. The current study used systematic research process adapted and presented by Hallinger (2013) to be used in social sciences in general and in educational leadership and management in particular. A standard process of finding relevant articles and examining reference lists is followed using articles from higher education which is the research context.

Findings

An examination of the literature showed that the majority of studies within the sample of articles are empirical representing 53 per cent, 32 per cent are conceptual, while only 15 per cent of the articles are a systematic literature review. Results also show that 58 per cent of the articles are teaching and learning related, 34 per cent are management related, while only 8 per cent are research related. Several challenges and opportunities of learning analytics in the three areas highlighted are presented and discussed.

Originality/value

The benefits and challenges of learning analytics are numerous and scattered in the literature. In this study, a typology related to different educational domains is developed to shed light on the benefits and challenges of learning analytics within particular higher education areas that are relevant to specific stakeholders. Benefits and challenges of learning analytics are classified into being management related, teaching and learning related and research related.
Family policies and fertility
Authors: Wesolowski Katharina , Ferrarini Tommy
Published: September 2018

Purpose

The purpose of this paper is to analyze the link between two different family policy dimensions – one supporting the combination of work and parenthood and one supporting stay-at-home mothers – and fertility rates between 1995 and 2011 in 33 industrialized countries.

Design/methodology/approach

Total fertility rates were regressed on the two policy dimensions, earner–carer support and traditional–family support, using pooled time-series analysis with country fixed effects and stepwise control for female labor force participation, unemployment rates and GDP.

Findings

The analyses show that earner–carer support is linked to higher fertility, while traditional–family support is not. Also, higher female labor force participation is linked to higher fertility before GDP is included. Conversely, higher unemployment is correlated with lower fertility levels. Sensitivity analyses with and without day care enrollment on a smaller set of countries show no influence of day care on the results for family policy.

Originality/value

The results give weight to the argument that family policies supporting the combination of work and parenthood could increase fertility in low-fertility countries, probably mediated in part by female labor force participation. Earnings-related earner–carer support incentivizes women to enter the labor force before parenthood and to return to work after time off with their newborn child, thus supporting a combination of work and parenthood.
Promoting radical innovation through end-user computing satisfaction
Authors: Domínguez-Escrig Emilio , Broch Francisco Fermín Mallén , Lapiedra Rafael , Chiva Ricardo
Published: September 2018

Purpose

The purpose of this paper is to provide empirical evidence of the relationship between end-user computing satisfaction (EUCS) and radical innovation, using organizational learning as an explanatory variable.

Design/methodology/approach

An empirical study was conducted in a population of 402 Spanish companies. A sample of 251 valid questionnaires was obtained. Structural equations were used to validate the proposed hypotheses.

Findings

Organizational learning capability fully mediates the relationship between EUCS and radical innovation.

Research limitations/implications

The sample of companies is heterogeneous in terms of size, sector, age and market share. The study uses single informants.

Practical implications

Results highlight the need to implement adequate information systems to promote radical innovation. In addition, it is necessary to facilitate organizational contexts that encourage dialogue, experimentation, risk-taking, participative decision-making and openness to the external environment.

Originality/value

This research contributes to the study of alternative antecedents of radical innovation by highlighting the importance of EUCS.
Effect of labelled information and sensory attributes on consumers’ intention to purchase milk
Authors: Hoque Mohammed Ziaul , Xie Jinghua , Nazneen Suraiya
Published: September 2018

Purpose

The purpose of this paper is to examine the influences of consumer perceptions of labelled information and sensory attributes on consumers’ intention to buy fresh milk.

Design/methodology/approach

An experiment was conducted on 117 consumers in a lab at a university. After closely inspecting the labels’ information and tasting two types of milk, participants were asked to fill in a questionnaire, using the direct interview method. Exploratory factor analysis, confirmatory factor analysis and structural equation modelling were applied to analyse the data.

Findings

The results show that products’ labelled information and the sensory perceptions increase the buying intention of both ultra-high temperature treated fresh milk (UFM) and pasteurised fresh milk (PFM). The sensory perceptions of PFM can mediate the relationship between products’ labels and consumer buying intentions, but this relationship is not true for UFM. According to our results, nutritional facts and taking responsibility for one’s health are the keys to fresh milk commercialisation in terms of higher relative weights and commonness.

Originality/value

Although the sensory aspects of milk have been rigorously evaluated in the food science literature, to the best of the authors’ knowledge, few studies have focussed on the sensory perceptions of fresh milk incorporating process categories (UFM and PFM) and their mediating effect between labelled information and buying intention in the social sciences. The study is pioneering in that it investigates the perceptions of sensory attributes affecting consumer purchasing decisions for fresh milk in an emerging market.
Organizational learning as participants’ knowledge harvesting from product development
Authors: Tolsby June
Published: September 2018

Purpose

This paper aims to introduce the term, knowledge harvesting, as an aid for researchers in comprehending what knowledge strategies influences projects, where to find knowledge, how to visualize knowledge, how to cultivate knowledge, who distributes project knowledge and how to gain former project knowledge.

Design/methodology/approach

The term knowledge harvesting emerged after having analyzed employees interviews at a Danish welding machine manufacturer using an adjusted grounded theory.

Findings

Employees’ knowledge harvesting strategies involve collecting knowledge, making knowledge visible in projects, introducing knowledge in projects, identifying knowledge deficiencies, cultivating knowledge to support projects and ensuring readily available historical knowledge termed para-knowledge.

Practical implications

To strengthen how significant and relevant knowledge harvesting can be, researchers need to apply knowledge harvesting as an explanation in their own research projects. Only then will knowledge harvesting becomes a solid explanation of what knowledge strategies employees apply and their implications for organization learning.

Originality/value

Knowledge harvesting introduces new understandings regarding employees’ knowledge acquisition processes during product development. Knowledge harvesting can help researchers to understand and identify how, why and what knowledge processes take place throughout product development.
Preparation and characterization of transparent magneto‐optical Ho2O3 ceramics
Authors: Lu Bin , Cheng Hongmei , Xu Xinxin , Chen Hongbing
Published: September 2018

Transparent magneto‐optical Ho2O3 ceramics were successfully prepared with an in‐line transmittance of ~73% at the wavelength of 1000 nm (~90% of the theoretical transmittance of Ho2O3 single crystal) and an average grain size of ~28 μm. The ceramics were fabricated using sulfate‐exchanged nitrate‐type layered rare‐earth hydroxide as the precipitation precursor at a relatively low sintering temperature of 1700°C. The layered compound exhibited nanosheet morphology and fully collapsed into a round oxide powder with an average particle size of ~48 nm by pyrolysis. Calcination temperature for Ho2O3 powder significantly affected the optical quality of the sintered body and the optimum calcination temperature was found to be 1050°C. The transparent magneto‐optical Ho2O3 ceramics displayed wavelength‐dependent Verdet constants of −180, −46, and −20 rad/Tm at 632, 1064, and 1550 nm, respectively. Thus, the Ho2O3 ceramics show good potential for applications in high‐power laser systems.
High carriers transmission efficiency ZnS/SnS2 heterojunction channel toward excellent photoelectrochemical activity
Authors: Zhang Jun , Huang Guozhou , Zeng Jinghui , Shi Yuxuan , Lin Songjun , Chen Xuan , Wang Hongbo , Kong Zhe , Xi Junhua , Ji Zhenguo
Published: September 2018

ZnS has been found superiority in photoelectrochemistry for the fast response of photo‐inducing and its high conductor band position (~0.8 eV) results in strong reduction ability for hydrogen production. However, the solar absorbance of ZnS is much low for the wide band gap (~3.2 eV) and the carriers’ migration efficiency also need to be improved. Here, nano‐ZnS were coupled with ultrathin SnS2 nanosheets as heterojunction composites. This heterojunction composite demonstrated largely increase in specific surface area (from 4 to 12‐25 m2/g), obvious improvement of UV‐vis absorbance and narrower band gap. Furthermore, the carriers’ migration efficiency of ZnS/SnS2 heterojunction has been confirmed to be much higher by photocurrent response and electrochemical impedance spectroscopy. Due to the improvement in structure, compared with pristine ZnS, this ZnS/SnS2 heterojunction exhibited vast enhancement in photoelectrochemical performance. The composite with best activity exhibited 12.8 times enhancement in photocurrent density. The conduction band and valence band of ZnS are both more negative than those of SnS2, the photo‐induced electrons at the conduction band of ZnS will transfer into the conduction band of SnS2 while the photo‐induced holes at the valence band of SnS2 will transfer into the valence band of ZnS. In this way, the photo‐produced carriers will flow into different semiconductors and the carriers’ migration efficiency is enhanced. The work improves a new structure to develop the heterojunction property for photoelectrochemical application.
Teriflunomide's Effect on Glia in Experimental Demyelinating Disease: A Neuroimaging and Histologic Study
Authors: Pol Suyog , Sveinsson Michele , Sudyn Michelle , Babek Natan , Siebert Danielle , Bertolino Nicola , Modica Claire M. , Preda Marilena , Schweser Ferdinand , Zivadinov Robert
Published: September 2018

BACKGROUND AND PURPOSE

Teriflunomide reduces disability progression and brain atrophy in multiple sclerosis patients. The exact mechanism of action by which teriflunomide exerts these effects is currently unknown. We assessed the effect of teriflunomide on brain glial cells in the Theiler's murine encephalomyelitis virus (TMEV) by using a histological approach in combination with neuroimaging.

METHODS

Forty‐eight SJL female mice received an intracerebral injection of TMEV at 6–8 weeks of age and were then treated with teriflunomide (n = 24) or placebo (n = 24) for 9 months. They were examined with MRI and behavioral testing at 2, 6, and 9 months postinduction (mPI). Of those, 18 teriflunomide‐treated and 17 controls mice were analyzed histologically at 9 mPI to sample from different brain regions for myelination status, microglial density, and oligodendroglial lineage. The histological and MRI outcomes were correlated.

RESULTS

Corpus callosum microglial density was numerically lower in the teriflunomide‐treated mice compared to the control group (141.1 ± 21.7 SEM vs. 214.74 ± 34.79 SEM, Iba1+ cells/mm2, P = .087). Basal ganglia (BG) microglial density in the teriflunomide group exhibited a negative correlation with fractional anisotropy (P = .021) and a positive correlation with mean diffusivity (P = .034), indicating less inflammation and axonal damage. Oligodendroglial lineage cell and myelin density were not significantly different between treatment groups. However, a significant positive correlation between BG oligodendrocytes and BG volume (P = .027), and with N‐acetyl aspartate concentration (P = .008), was found in the teriflunomide group, indicating less axonal loss.

CONCLUSION

Teriflunomide altered microglia density and oligodendrocytes differentiation, which was associated with less evident microstructural damage on MRI.
Hubungan Antara Trait Personaliti Kehematan, Keterbukaan, Ekstraversidan Kesetujuan Dengan Kecerdasan Emosi Dalam Kalangan Pemimpin Pendidik Sekolah Berprestasi Tinggi (SBT)
Authors: Md Nawi Nurul Hudani , Redzuan Ma'rof , Md Nawi Noor Hisham
Published: September 2018

The main objective of this cross-sectional study is to determine inter relationship of emotional intelligence and personality trait (Conscientiousness, Openness to experiences, Extraversion, Agreeableness) among school educator leaders in High Performance Schools (SBT). Two sets of questionnaire to measure emotional intelligence and personality trait were administered to 306 (89%) subjects who were selected by stratified random sampling in 15 SBT schools in Malaysia. Data were analyzed through inferential statistics such as correlation. The finding by the bivariate analysis using the Pearson correlation method indicates that the personality trait such as Conscientiousness (r=.552, p<.05), Openness to experiences (r=.362, p<.05), Extraversion (r=.505, p<.05), Agreeableness (r=.193, p<.05) are positively and significant correlated with overall emotional intelligence among the schools educator leaders. The correlation values of the personality Conscientiousness trait (r=.552, p<.05) are higher than the correlation values of the rest of others personality traits and emotional intelligence. This finding suggests that personality Conscientiousness trait have stronger relationship with emotional intelligence compare to the others traits. On a practical note, the assessment of psychological construct in schools setting such as emotional intelligence and personality could possibly assist in enhancing the work performances in delivering huge benefits to the society especially in the educational
Short‐term and long‐term human or mouse organoid units generate tissue‐engineered small intestine without added signalling molecules
Authors: Hou Xiaogang , Chang David F. , Trecartin Andrew , Barthel Erik R. , Schlieve Christopher R. , Frey Mark R. , Fowler Kathryn L. , Grikscheit Tracy C.
Published: September 2018

New Findings

What is the central question of this study?

Tissue‐engineered small intestine was previously generated in vivo by immediate implantation of organoid units derived from both mouse and human donor intestine. Although immediate transplantation of organoid units into patients shows promise as a potential future therapy, some critically ill patients might require delayed transplantation.

What is the main finding and its importance?

Unlike enteroids, which consist of isolated intestinal crypts, short‐ and long‐term cultured organoid units are composed of epithelial and mesenchymal cells derived from mouse or human intestine. Organoid units do not require added signalling molecules and can generate tissue‐engineered intestine in vivo.

Mouse and human postnatal and fetal organoid units (OUs) maintained in either short‐term culture (2 weeks) or long‐term culture (from 4 weeks up to 3 months) without adding exogenous growth factors were implanted in immunocompromised mice to form tissue‐engineered small intestine (TESI) in vivo. Intestinal epithelial stem and neuronal progenitor cells were maintained in long‐term OU cultures from both humans and mice without exogenous growth factors, and these cultures were successfully used to form TESI. This was enhanced with OUs derived from human fetal tissues. Organoid unit culture is different from enteroid culture, which is limited to epithelial cell growth and requires supplementation with R‐Spondin, noggin and epidermal growth factor. Organoid units contain multiple cell types, including epithelial, mesenchymal and enteric nervous system cells. Short‐ and long‐term cultured OUs derived from mouse and human intestine develop into TESI in vivo, which contains key components of the small intestine similar to native intestine.
A Simple Model for the Distribution of Dark Matter
Authors: Kaura Lakshya , Mallya Akshat , Singh Vijay A.
Published: September 2018

In recent times, the subject of dark matter has engaged the public thanks to reports in popular scientific journals and newspapers. In a first course in physics, we frequently encounter questions regarding reasons for belief in dark matter. Related questions regarding the composition and density of dark matter are also raised. In this article, we address the issue of the density distribution of dark matter.
Towards Meaningful Physics Recognition: What does this recognition actually look like?
Authors: Hazari Zahra , Cass Cheryl
Published: September 2018

In the February 2017 issue of The Physics Teacher, an article was presented that highlighted the importance of high school physics teachers in inspiring women in physics, particularly by recognizing them as being a “physics person.” Drawing on data from over 900 female undergraduates in physics, the article showed that the largest fraction became interested in physics careers during high school. In particular, being recognized by their physics teacher substantially increased the odds of their planning physics careers by the beginning of college. Since this article was published, questions have been directed toward us from physics teachers regarding the nature of recognition, e.g., how do we recognize a student meaningfully and what does recognition look like in the classroom? For example, one teacher wrote saying: I specifically wanted to tell you how much I appreciated this: …your closing note that not all recognition is meaningful, and that the key is high expectations for all and recognition of when [expectations are] met…I wrote in my margins on the page before, “What does this recognition actually look like?”
Building Measurement Devices with Students – From Hands-on to Minds-on
Authors: Porat Gilit , Kapon Shulamit
Published: September 2018

Although the teaching of mechanics at advanced K12 levels often starts with a brief introduction to physical quantities and units, the nature and function of measurements in physics and their inherent uncertainty are hardly ever discussed. The laboratory is mainly used to illustrate the theoretical principles taught in class. This paper presents a project-based learning approach that aims to provide high school students with a sense of the nature and role of measurements in physics (units, uncertainty, etc.) as well as help them develop laboratory, data analysis, and scientific communication skills in a fun and engaging way. Each project involves the design, building, and calibration of a measurement device for a basic physical quantity (time, length, and mass). Each measurement device is made up of recycled materials (e.g., plastic bottles) and simple pieces of equipment available in any high school physics laboratory (e.g., springs). The students build the device, calibrate it, and write a detailed documentation that explains how it works, its specifications, and instructions for use. The students also present their work to peers and visitors. We describe five basic measurement devices, the scaffolding we used to help the students make the transition from the “arts and crafts” aspect of the work to its deeper scientific meaning, and different orchestrations for various classroom settings.
The dynamics of the magnetic linear accelerator examined by video motion analysis
Authors: Becker Sebastian , Thees Michael , Kuhn Jochen
Published: September 2018

Amagnetic linear accelerator (or Gauss accelerator) is a device that uses the conversion of magnetic energy into kinetic energy to launch an object with high velocity. A simple experimental implementation consists of a line of steel spheres in which the first one is a permanent magnetic sphere. If another steel ball collides with the magnetic sphere from the left, the rightmost steel sphere is ejected at a much larger velocity than the impacting steel sphere. Several approaches have been published to determine the velocity of the ejected sphere, for example by using photogates or by measuring the impact position of the ejected sphere after falling from a table. All of these approaches have in common that the measurement of the velocity is a static process. This article describes an approach in which video motion analysis on tablet computers is used to measure simultaneously the time course of the velocity of the impacting steel sphere as well as the ejected steel sphere, thus giving students insight into the dynamics of the processes that lead to a higher kinetic energy of the ejected sphere.
Help! – I was just hired as a new teacher and I have to teach physics!
Authors: Johnson Jeff S.
Published: September 2018

“I’m starting my first year teaching physics next week. I taught ed-tech last year and was an engineer for some years before that. As of today, I have zero lessons planned. I have made a survey to have my students fill out on the first day, and that is about it. I’ll be teaching both the AP and Basic level Physics.”
A modular backbone aided the rise of mammals
Authors: Pennisi Elizabeth
Published: September 2018

Fossils show how lumbar vertebrae were freed up to adapt to myriad lifestyles.
Brain scientists dive into deep neural networks
Authors: Servick Kelly
Published: September 2018

Increasingly skilled artificial intelligence could hold clues to human sensory systems.
Research on research
Authors: Enserink Martin
Published: September 2018

A growing number of scientists is studying science itself.
The truth squad
Authors: Stokstad Erik
Published: September 2018

In its drive to expose weaknesses in science, an up-and-coming research group doesn't mind stepping on some toes.
Bacterial antagonism in host-associated microbial communities
Authors: García-Bayona Leonor , Comstock Laurie E.
Published: September 2018

Interspecies competition shapes communities

The gut microbiota of mammals is diverse and dynamic, and gut bacteria respond sensitively to diet and drug intake. Nevertheless, in a healthy adult, microbial community composition remains remarkably stable over time, despite being highly individual. García-Bayona and Comstock review the mechanisms that gut bacterial species use to jostle for space and resources and maintain their populations in the face of intense and varied competition. Bacteria have evolved a range of antibiotics, bacteriocins, toxins, and delivery devices to enable interspecies conflict. These interbacterial weapons possess a spectrum of specificities and range from those that target strains of their own species to broad-acting bacteriocides. This toxic armamentarium provides a valuable resource for potential therapeutic development.

Science
, this issue p.
eaat2456
A gut-brain neural circuit for nutrient sensory transduction
Authors: Kaelberer Melanie Maya , Buchanan Kelly L. , Klein Marguerita E. , Barth Bradley B. , Montoya Marcia M. , Shen Xiling , Bohórquez Diego V.
Published: September 2018

Dissecting the gut-brain axis

It is generally believed that cells in the gut transduce sensory information through the paracrine action of hormones. Kaelberer
et al.
found that, in addition to the well-described classical paracrine transduction, enteroendocrine cells also form fast, excitatory synapses with vagal afferents (see the Perspective by Hoffman and Lumpkin). This more direct circuit for gut-brain signaling uses glutamate as a neurotransmitter. Thus, sensory cues that stimulate the gut could potentially be manipulated to influence specific brain functions and behavior, including those linked to food choices.

Science
, this issue p.
eaat5236
; see also p.
1203
A gut feeling
Authors: Hoffman Benjamin U. , Lumpkin Ellen A.
Published: September 2018

Gut-brain signaling involves neurotransmission from gut sensory epithelial cells
OmniSkins: Robotic skins that turn inanimate objects into multifunctional robots
Authors: Booth Joran W. , Shah Dylan , Case Jennifer C. , White Edward L. , Yuen Michelle C. , Cyr-Choiniere Olivier , Kramer-Bottiglio Rebecca
Published: September 2018

Robotic skins are planar substrates with embedded actuation and sensing that can wrap around soft objects to turn them into robots.
Self-monitoring of blood glucose in insulin-treated diabetes: a multicase study
Authors: Cameron Dawn , Harris Fiona , Evans Josie M M
Published: September 2018

Objective

To explore how and why self-monitoring of blood glucose (SMBG) is carried out in a real-world context.

Research design and methods

We conducted a multicase study among ten people with type 1 and insulin-treated type 2 diabetes mellitus in Scotland, alongside seven nominated support people and four healthcare professionals. All participants were interviewed in depth and six participants provided SMBG diaries. Stones’ version of structuration theory informed the analysis.

Results

People with diabetes were able to provide immediate motives for SMBG at particular times, often having different motives on different occasions. We identified six such motives, including routine, in response to symptoms, associated with a diabetes review, to facilitate lifestyle, when a ‘good’ result was expected, and higher level motives for longer term glycemic control. These motives were influenced by underlying attitudes toward diabetes that included level of engagement and responsibility for diabetes, a desire not to be controlled by diabetes, resistance to diabetes, diabetes education and relationship with the health service, fear of hypoglycemia, and prevention of diabetes complications. Five responses to test results were identified, depending on the immediate motive and underlying attitudes.

Conclusions

People with insulin-treated diabetes do not necessarily self-monitor with an explicit goal of improving long-term glycemic control, but may have other motives that are important to them. An individualized understanding is therefore needed to advise people with diabetes how SMBG can be optimized for them.
Using a common data platform to facilitate audit and feedback on the quality of hospital care provided to sick newborns in Kenya
Authors: Maina Michuki , Aluvaala Jalemba , Mwaniki Paul , Tosas-Auguet Olga , Mutinda Catherine , Maina Beth , Schultsz Constance , English Mike
Published: September 2018

Essential interventions to reduce neonatal deaths that can be effectively delivered in hospitals have been identified. Improving information systems may support routine monitoring of the delivery of these interventions and outcomes at scale. We used cycles of audit and feedback (A&F) coupled with the use of a standardised newborn admission record (NAR) form to explore the potential for creating a common inpatient neonatal data platform and illustrate its potential for monitoring prescribing accuracy. Revised NARs were introduced in a high volume, neonatal unit in Kenya together with 13 A&F meetings over a period of 3  years from January 2014 to November 2016. Data were abstracted from medical records for 15 months before introduction of the revised NAR and A&F and during the 3 years of A&F. We calculated, for each patient, the percentage of documented items from among the total recommended for documentation and trends calculated over time. Gentamicin prescribing accuracy was also tracked over time. Records were examined for 827 and 7336 patients in the pre-A&F and post-A&F periods, respectively. Documentation scores improved overall. Documentation of gestational age improved from <15% in 2014 to >75% in 2016. For five recommended items, including temperature, documentation remained <50%. 16.7% (n=1367; 95%  CI 15.9 to 17.6) of the admitted babies had a diagnosis of neonatal sepsis needing antibiotic treatment. In this group, dosing accuracy of gentamicin improved over time for those under 2  kg from 60% (95%36.1 to 80.1) in 2013 to 83% (95% CI 69.2 to 92.3) in 2016. We report that it is possible to improve routine data collection in neonatal units using a standardised neonatal record linked to relatively basic electronic data collection tools and cycles of A&F. This can be useful in identifying potential gaps in care and tracking outcomes with an aim of improving the quality of care.
Effect of vitamin D supplementation on serum 25-hydroxyvitamin D concentration in children and adolescents: a systematic review and meta-analysis protocol
Authors: Asghari Golaleh , Farhadnejad Hossein , Hosseinpanah Farhad , Moslehi Nazanin , Mirmiran Parvin , Azizi Fereidoun
Published: September 2018

Introduction

The importance of vitamin D for bone health as well as its role in non-skeletal functions has long been documented. However, review investigations on the effect of vitamin D supplementation on serum 25-hydroxyvitamin D (25(OH)D) levels in children and adolescents are scarce. The aims of the current study were to assess the impact of various doses of vitamin D supplementation on serum 25(OH)D concentrations in children and adolescents, and to identify relevant determinants of variations in the effect of vitamin D supplementation.

Methods

PubMed, Scopus, ISI Web of Science and Cochrane Central Register of Controlled Trials databases up to 27 September 2017 will systematically be searched for randomised controlled trials of vitamin D supplementation. We considered articles with the following control groups as eligible: placebo control, control group without any supplementation or a comparative arm investigation. Two reviewers will assess articles for eligibility according to prespecified selection criteria, after which data extraction and quality appraisal will be conducted by two independent reviewers. The quality assessment will be assessed using the Jadad scale. Meta-analyses will be conducted where appropriate. We will express continuous measures (ie, serum 25(OH)D concentration) as mean differences with 95% CIs. Heterogeneity of the data will be investigated via visual inspection of the forest plots and using χ2test on N-1 df, with a significance level of α=0.1. We will also assess individual study and subgroup characteristics and perform a sensitivity analysis. Publication bias will be assessed using funnel plot and statistical analysis of Egger’s test.

Ethics and dissemination

Ethics approval is not required because the work will be carried out on published documents. The authors will publish findings from this review through peer-reviewed publication or conference presentations.

PROSPERO registration number

CRD42017067179.
Associations between understanding of current treatment intent, communication with healthcare providers, preferences for invasive life-sustaining interventions and decisional conflict: results from a survey of patients with advanced heart failure in Singapore
Authors: Malhotra Chetna , Sim David , Jaufeerally Fazlur , Finkelstein Eric A
Published: September 2018

Objectives

To make informed choices about use of future invasive life-sustaining interventions (ILSI), patients with congestive heart failure (CHF) need to correctly understand the intent of their current treatments. However, healthcare providers may be wary of having these discussions due to fear of distressing patients. In this study, we assessed whether patients who understand their treatment intent are less willing to undergo ILSI and are indeed more psychologically distressed.

Design, participants and outcomes

As part of a cross-sectional survey conducted prior to randomising patients for a trial, we asked 282 patients with advanced CHF (New York Heart Association Class III and IV) whether they believe their existing treatments would cure their heart condition, their willingness to undergo ILSI and assessed their anxiety and depression using the Hospital Anxiety and Depression Scale.

Results

Approximately half of patients reported a willingness to undergo ILSI if needed. Only 22% knew that their current treatments were not curative. These patients were far less willing to undergo ILSI (OR 0.28, 95% CI 0.15 to 0.56) and were not at a greater risk of having clinically significant anxiety (OR 0.72, 0.34 to 1.54) and depression (OR 0.70, 0.33 to 1.47) compared with those who did not understand their current treatment intent.

Conclusions

Improving patients’ understanding of the intent of their current treatments can help patients make informed choices about ILSI.

Trial registration number

NCT02299180; Pre-results.
‘It's oxymoronic for vets to be activist vegans’
Authors: Howie Neil
Published: September 2018

Neil Howie argues that livestock farming is essential to meet the global demand for food and that vets should be focusing on improving the food‐animal cycle rather than abolishing it.
Donald Steven McGregor
Authors: Stephen Frank , Manson Sinclair , McLean Hamish
Published: September 2018

A caring, compassionate vet who showed the same dedication to all animals and their owners. As an excellent clinician and a skilled surgeon, his practice was built on values that were important to him.