bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bonds
Authors: Solymar L. , Walsh D. , Syms R. R. A. 
Published: October 2018

Abstract
Mechanical properties of bonds are discussed, with the aid of a simple phenomenological model in which the variation of energy as a function of distance between the elements is described in terms of polynomials. The properties of various kinds of bonds (ionic bond, metallic bond, covalent bond, van der Waals bond) are explained with the aid of simple models. Carbon is discussed with two examples: bonds between 60 atoms that lead to the formation of a three-dimensional molecule known as Buckminsterfullerene, and the alternative sheet-shaped configuration known as graphene, that has recently become the centre of interest. A general theory for finding the energy levels is introduced, relying on Feynman’s coupled wave equations. There is a brief reference to nuclear forces, followed by a discussion of the hydrogen molecule. The relationship between coupling and the splitting of the energy levels is discussed with an analogy to coupled resonant circuits.
The band theory of solids
Authors: Solymar L. , Walsh D. , Syms R. R. A. 
Published: October 2018

Abstract
The solution of Schrodinger’s equation is discussed for a model in which atoms are represented by potential wells, from which the band structure follows. Three further models are discussed, the Ziman model (which is based on the effect of Bragg reflection upon the wave functions), and the Feynman model (based on coupled equations), and the tight binding model (based on a more realistic solution of the Schrödinger equation). The concept of effective mass is introduced, followed by the effective number of electrons. The difference between metals and insulators based on their band structure is discussed. The concept of holes is introduced. The band structure of divalent metals is explained. For finite temperatures the Fermi–Dirac function is combined with band theory whence the distinction between insulators and semiconductors is derived.
Semiconductors
Authors: Solymar L. , Walsh D. , Syms R. R. A. 
Published: October 2018

Abstract
Both intrinsic and extrinsic semiconductors are discussed in terms of their band structure. The acceptor and donor energy levels are introduced. Scattering is discussed, from which the conductivity of semiconductors is derived. Some mathematical relations between electron and hole densities are derived. The mobilities of III–V and II–VI compounds and their dependence on impurity concentrations are discussed. Band structures of real and idealized semiconductors are contrasted. Measurements of semiconductor properties are reviewed. Various possibilities for optical excitation of electrons are discussed. The technology of crystal growth and purification are reviewed, in particular, molecular beam epitaxy and metal-organic chemical vapour deposition.
Magnetic materials
Authors: Solymar L. , Walsh D. , Syms R. R. A. 
Published: October 2018

Abstract
Macroscopic and microscopic theories of magnetic polarization are discussed. The origin of domains, domain walls, and of the hysteresis curve and the contrast between soft and hard magnetic materials are explained. The more important elements of the quantum theory of magnetism are discussed. The principles of the alignments in antiferromagnetic and ferromagnetic materials are explained. Magnetic resonance phenomena are discussed. Magnetoresistance and spintronics and their device prospects are also discussed at some length.
Lasers
Authors: Solymar L. , Walsh D. , Syms R. R. A. 
Published: October 2018

Abstract
Two-state and three-state systems are introduced. The properties of gaseous, solid state, and dye lasers are discussed and particular attention is devoted to semiconductor lasers. Reducing the dimensions leading to wells, wires, and dots is shown to have advantages. Quantum cascade lasers working in the THz region are discussed. The phenomena of Q switching, cavity dumping, and mode locking are explained. Parametric oscillators and optical fibre amplifiers are discussed. Masers are briefly mentioned. Laser noise is discussed. Awide variety of applications are mentioned. The curious phenomenon of laser cooling is explained. The basic principles of holographic recording and display are described.
Superconductivity
Authors: Solymar L. , Walsh D. , Syms R. R. A. 
Published: October 2018

Abstract
The Meissner effect is discussed. The latent heat of transition is derived by a thermodynamic approach. The concept of surface energy is introduced, leading to the distinction between Type I and Type II superconductors. The differential equation for the superconducting wave function is derived. The energy gap and the phenomenon of tunnelling are discussed. The difference between superconducting tunnelling and Josephson tunnelling is explained. The significance of high transition temperature superconductors is discussed. It is shown that an important application of superconductors is to produce high-field magnets.
Epilogue
Authors: Solymar L. , Walsh D. , Syms R. R. A. 
Published: October 2018

Abstract
The virtues of the profession of engineering are extolled. The views of one of the greatest electrical engineers (Rudolf Kompfner) of the last century are quoted as follows: “The feeling one experiences when he obtains a new important insight when a crucial experiment works, when an idea begins to grow and bear fruit, these mental states are indescribably beautiful and exciting. Nomaterial reward can produce effects even distantly approaching them. Yet another benefit is that an inventor can never be bored. There is no time when I cannot think of a variety of problems. All waiting to be speculated about, perhaps tackled, perhaps solved. All one has to do is to ask the questions, why? How? And not be content with the easy, the superficial answer.”
The Twang Factor in Country Music
Authors: Neal Jocelyn R. 
Published: October 2018

Abstract
The term twang in instrumental and vocal contexts carries powerful associations within country and western music. Revered by some and disdained by others, twang indexes rural traditions, untrained singers, and, consequently the pride in this cultural heritage. This chapter explores the sonic properties of twang in both instruments and the human voice, the cultural implications and reception of twang, and the deemphasis on twang in Nashville’s country music scene in the 1950s. It presents a case study of two contrasting recordings by Jim Reeves (one with liberal use of twang and one without), examines the sonic character of country albums from Ray Charles and Connie Francis, and investigates the contemporary politics of twang in country music.
Conceived in Harlesden: Candidate-Centred Campaigning in British General Elections
Authors: Milazzo Caitlin , Townsley Joshua 
Published: October 2018

AbstractRecent decades have seen an increasing trend towards the personalisation of election campaigns, even in systems where candidates have few structural incentives to emphasise their personal appeal. In this article, we build on a growing literature that points to the importance of candidate characteristics in determining electoral success. Using a dataset composed of more than 3700 leaflets distributed during the 2015 and 2017 general elections, we explore the conditions under which messages emphasising the personal characteristics of prospective parliamentary candidates appear in British general election campaign materials. Even when we account for party affiliation, we find that there are important contextual and individual-level factors that predict the use of candidate-centred messaging.
Dirac cohomology, the projective supermodules of the symmetric group and the Vogan morphism
Authors: Calvert Kieran 
Published: October 2018

Abstract
We derive an explicit description of the genuine projective representations of the symmetric group Sn using Dirac cohomology and the branching graph for the irreducible genuine projective representations of Sn. Ciubotaru and He [D. Ciubotaru and X. He, Green polynomials of Weyl groups, elliptic pairings, and the extended index. Adv. Math., 283:1–50, 2015], using the extended Dirac index, showed that the characters of the projective representations of Sn are related to the characters of elliptic-graded modules. We derive the branching graph using Dirac theory and combinatorics relating to the cohomology of Borel varieties ℬe of g and are able to use Dirac cohomology to construct an explicit model for the projective representations. We also describe Vogan’s morphism for Hecke algebras in type A using spectrum data of the Jucys–Murphy elements.
The Costs of Agglomeration: House and Land Prices in French Cities
Authors: Combes Pierre-Philippe , Duranton Gilles , Gobillon Laurent 
Published: October 2018

AbstractWe develop a new methodology to estimate the elasticity of urban costs with respect to city population using French house and land price data. After handling a number of estimation concerns, we find that the elasticity of urban costs increases with city population with an estimate of about 0.03 for an urban area with 100,000 inhabitants to 0.08 for an urban area of the size of Paris. Our approach also yields a number of intermediate outputs of independent interest such as the share of housing in expenditure, the elasticity of unit house and land prices with respect to city population, and within-city distance gradients for house and land prices.
Effects of supplement type and narasin inclusion on supplement intake by Bos indicus beef bulls grazing a warm-season forage
Authors: Cappellozza Bruno I , Lasmar Pedro V F , Reis Flávea T , Oliveira Leane , Hoe Fernanda , Boehler Ryan M , Leibovich Jose , Starkey Robert , Simas José , Cooke Reinaldo F 
Published: October 2018

Abstract
This study aimed to evaluate the effects of supplement type and narasin inclusion on the frequency and supplement intake of grazing Bos indicus beef bulls. Four hundred animals were ranked by initial BW (383 ± 35 kg) and allocated into one of four paddocks of Brachiaria brizantha cv. Marandú (100 animals/paddock). Paddocks were randomly assigned to receive either a mineral salt (MIN) or a protein-energetic supplement (PREN) containing or not narasin (N) for a 90-d period. An individual electronic data capture system with 11 feed bunks was used to individually measure supplement intake and meal frequency in each paddock. The evaluations and analysis of individual intake, frequency of visits to the feeder, and intake per visit (I/V) were performed every 15 d and classified as periods (PR1 through PR6). All data were analyzed as a 2 × 2 factorial design with the PROC MIXED procedure of SAS. A supplement type × N × PR interaction was observed (P &lt; 0.0001) for daily supplement intake. No differences were observed between MIN, whereas PREN had a greater (P ≤ 0.03) supplement intake on PR1 and PR3, but a reduced supplement intake on PR6 compared with PREN + N (P = 0.02). Moreover, no supplement type × N interaction (P = 0.47) or N (P = 0.44) effects were observed for daily supplement intake in the present study. A supplement type × N × PR interaction was detected (P &lt; 0.0001) for the frequency of visits in the feeders. Throughout the experimental period, animals from the MIN + N had a greater (P ≤ 0.02) frequency of visits compared with MIN cohorts. A supplement effect was detected for I/V (P = 0.02), whereas neither a narasin effect (P = 0.74) nor interactions (P ≥ 0.16) were observed. Animals offered PREN had a greater I/V when compared with MIN cohorts (145 vs. 846 g/d for MIN and PREN, respectively; SEM = 16.1). When these data are reported as percentage of days visiting the feeder within each PR, MIN and MIN + N animals visited the feeder for 25.8% and 35.9% of the days, respectively. Conversely, no differences were observed (P = 0.65) in the overall mean visits per PR between PREN and PREN + N (12.8 vs. 12.3 d for PREN and PREN + N, respectively; SEM = 0.195). As percentage of days visiting the feeder, PREN and PREN + N visited the feeder for 85.1% and 81.9% of the days, respectively. In summary, narasin inclusion did not reduce supplement intake, regardless of supplement type, but increased the frequency of visits to the feeder for the MIN treatment.
Mineral status of California beef cattle1
Authors: Davy Josh S , Forero Larry C , Shapero Matthew W K , Rao Devii R , Becchetti Theresa A , Koopman Rivers Carissa , Stackhouse Jeffery W , DeAtley Kasey L , McNabb Bret R 
Published: October 2018

AbstractOptimal mineral nutrition is required for cattle reproduction, immune function, and structural development. Formal evaluation of the current mineral status of California beef cattle is currently lacking. In 2017, a survey was initiated that evaluated a panel of 10 different minerals in 14 counties across California. Samples were collected from 555 cattle at 50 different ranches. Region of the state significantly affected herd mineral status. Herd use of supplements was also significant, and increased most blood levels of the mineral(s) targeted for supplementation. Forage source was idiosyncratic on its effect of mineral status. Previous blood survey data showed selenium to be widely deficient in California cattle in the 1970s and 1980s, but in this case, it was generally adequate in all areas of California. This indicates a good producer understanding of where supplementation is needed. Copper deficiency was more widespread in the southern region when compared with further north. Zinc deficiency was seen ubiquitously statewide, with 36% of animals being deficient. Manganese has been largely ignored in California. This study is the first known documentation of manganese levels in the state. Sampling found 92% of cattle fell below critical manganese levels. However, further research to better define manganese critical levels is probably warranted. The status of other minerals is presented.
The Social Media Editor at Medical Journals: Responsibilities, Goals, Barriers, and Facilitators
Authors: Lopez Melany , Chan Teresa M. , Thoma Brent , Arora Vineet M. , Trueger N. Seth 
Published: October 2018

Purpose
To determine the responsibilities of journal social media editors (SMEs) and describe their goals and barriers and facilitators to their position.

Method
The authors identified SMEs using an informal listserv and snowball sampling. Participants were interviewed (June–July 2016) about their position, including responsibilities; goals; barriers and facilitators; and attitudes and perceptions about the position. Themes were identified through a thematic analysis and consensus-building approach. Descriptive data, including audience metrics and 2016 impact factors, were collected.

Results
Thirty SMEs were invited; 24 were interviewed (19 by phone and 5 via e-mail). SMEs generally had a track record in the social media community before being invited to be SME; many had preexisting roles at their journal. Responsibilities varied considerably; some SMEs also served as decision editors. Many SMEs personally managed journal accounts, and many had support from nonphysician journal staff. Consistently, SMEs focused on improving reader engagement by disseminating new journal publications on social media. The authors identified goals, resources, and sustainability as primary themes of SMEs’ perspectives on their positions. Editorial leadership support was identified as a key facilitator in their position at the journal. Challenges to sustainability included a lack of tangible resources and uncertainty surrounding, or a lack of, academic credit for social media activities.

Conclusions
Many of the participating SMEs pioneered the use of social media as a platform for knowledge dissemination at their journals. While editorial boards were qualitatively supportive, SMEs were challenged by limited resources and lack of academic credit for social media work.
Drug Misuse and Hepatitis C Virus Infection Profiles for Three Generations of Patients Being Monitored for Prescription Drug Adherence
Authors: McClure Fred Leland , Niles Justin K. , Kaufman Harvey W. , Gudin Jeffrey 
Published: October 2018

Objectives:
Two epidemics in the United States are related: opioid drug injection and hepatitis C virus (HCV) infection. This study quantifies the relationship between illicit/prescription drug misuse and HCV infection in 3 population generations: baby boomers (born 1945–1965, inclusive), pre-baby boomers, and post-baby boomers.

Methods:
This retrospective study included prescription drug consistency (March–December 2015) and HCV (2011–2015) patient test results performed at a large national clinical reference laboratory. HCV positivity, drug use consistency/inconsistency with prescribed drug information, type of inconsistent use, and inconsistent use of individual drug classes were assessed.

Results:
This study evaluated 39,231 prescription drug monitoring and HCV sets of test results from 18,410 patients. Of these patients, 25.1% tested positive for HCV and 57.3% demonstrated drug test results that were inconsistent with the prescribed medication(s). The types of drug test inconsistency differed substantially between HCV-positive and -negative patients, particularly testing positive for both non-prescribed drugs and prescribed drugs. Specimens from HCV-positive baby boomer and post-baby boomers demonstrated non-prescribed use of opioids and many other drug classes more often than from HCV-negative patients.

Conclusions:
The rates of inconsistent drug test results and types of drugs misused suggest that HCV-positive patients are more likely than HCV-negative patients to display high-risk behavior, even beyond opioid use. This difference is most pronounced in the post-baby boomer generation. Healthcare professionals should consider these patterns and how they differ by generation when monitoring for both prescription and illicit drugs, the results of which can impact treatment decisions including prescribing analgesics.
Do Academic Health Care Systems Really Value Education? A Survey of Academic Plastic Surgeons
Authors: Sun Helen H. , Pourtaheri Navid , Janis Jeffrey E. , Becker Devra B. 
Published: October 2018

Background:
Although education is critical to the mission of academic medical centers in the United States, it is often not quantified and monetized as are their research and clinical missions. We undertook this survey to assess the perceived valuation of educational endeavors of plastic surgeon faculty at the U.S. academic medical centers.

Methods:
A survey using Qualtrics software (Qualtrics, Provo, UT) was distributed to faculty members of the American Council of Academic Plastic Surgeons by electronic mail in February 2015. A total of 16 questions included both demographic information and Likert-item questions of perception of valuation of educational activities. For analysis, responses were grouped according to an adapted Net Promoter Score including “unsupportive” (0–6), “neutral” (7–8), and “supportive” (9–10).

Results:
Sixty-five surveys were completed out of a total of 406, with an overall response rate of 16%. Kruskal-Wallis statistical analysis demonstrated that region and rank were not significant in perception of hospital or departmental support for educational activities. Respondents rated their departments as more supportive than their institutions (P < 0.05), and average perceived value rating of institutions was “unsupportive.” Financial support was associated with higher ratings with respect to support of institutions and departments. Mid-career faculty displayed a trend toward lower ratings of perception of support.

Conclusions:
The majority of respondents perceived their institutions and departments as unsupportive of educational effort. Direct compensation to physicians for teaching efforts may improve faculty retention in academia and reduce physician burnout.
Communication Course for Pediatric Providers Improves Self-efficacy
Authors: Grome Luke J. , Banuelos Rosa C. , Lopez Michelle A. , Nicome Roger K. , Leaming-Van Zandt Katherine J. 
Published: October 2018

Background:
Communication is essential to building a trusting, clinician-patient relationship. Multiple studies have demonstrated the effects of experiential communication training on patient experience and provider well-being and resiliency. To date, no studies have described an organization-wide communication training program for pediatric clinicians. The objective of this study was to evaluate the impact of a pediatric-focused communication course on provider satisfaction, self-efficacy, and burnout.

Methods:
Texas Children’s Hospital, in collaboration with the Academy on Communication in Healthcare, designed and implemented a pediatric focused communication course entitled Breakthrough Communication. Pre, immediate-post, and 3-month postcourse completion online surveys were sent to participants 1 day before, 1 day after, and 3 months after course completion. Participant demographic information, self-assessment of communication skills, the Maslach Burnout Inventory Human Services Survey, and postcourse satisfaction data were collected.

Results:
Participants reported high course satisfaction and improved self-efficacy in all measured skill sets both following and 3 months after course completion. Trends indicating a reduction in provider burnout improved in 2 of the 3 Maslach Burnout Inventory domains; however, statistical significance was not achieved.

Conclusions:
A pediatric-focused communication course was well received by multi-specialty clinicians within a large, academic health care organization. This course enhanced clinician self-efficacy with newly learned pediatric encounter specific communication skills.
Simple-safe-sure Fluid Drainage Just above Breast Tissue Expander using 18-Gauge Blunt Cannula
Authors: Kagaya Yu , Arikawa Masaki , Kageyama Daisuke , Sekiyama Takuya , Akazawa Satoshi 
Published: October 2018

Summary:
The presence of seroma after breast tissue expander (TE) insertion for a long duration can cause infection and purulency; thus, obvious fluid collection around TEs should be drained as early as possible. However, due to the risk of puncture, it may not be possible to completely drain the fluid if it is located above the TE. To manage such cases, we used an 18-gauge blunt cannula and achieved good results. Among 98 cases in which breast reconstruction was performed with a TE, 5 patients had symptoms of infection with fluid collection just above the TE. In all 5 cases, resolution of the infection was observed in an outpatient setting without the removal or puncture of the inserted TE, by performing a drainage technique using an 18-gauge blunt cannula. An 18-gauge blunt cannula minimized the risk of expander rupture during drainage and enabled the complete aspiration of fluid, even when it was located just above the TE; thus, the resolution of infection with the preservation of the expander was possible in cases that would otherwise have been impossible to treat without the removal of the TE. This drainage procedure using an 18-gauge blunt cannula is considered to be simple, safe, and sure, with benefits that exceed the risk; thus, there should be no reason to hesitate in performing this drainage procedure, even in cases involving slight fluid collection around the TE.