bluuebunny/crossref_metadata_2025 huggingface dataset:
Retrospective Evaluation of the Short-Term Sustainability of the Locally Grown Produce Initiative of the Hunger Prevention and Nutrition Assistance Program in New York State
Authors: Allsopp Marie A. K. , Hosler Akiko S.
Published: March 2018

Context:

The Hunger Prevention and Nutrition Assistance Program (HPNAP) is a New York State Department of Health program. The HPNAP improves nutritional quality of food available at food banks, food pantries, soup kitchens, and emergency shelters through contractual relationships to fund the purchase, delivery, storage, and service of nutritious food.

Objective:

To determine whether a one-time fiscal stimulus of the Locally Grown Produce Initiative to HPNAP contractors in 2012-2013 would result in a short-term sustainable increase in the proportion of dollars spent on New York State Grown (NYSG) produce.

Design:

Quasi-experimental, nonequivalent control group design. We analyzed New York State Department of Health administrative data regarding expenditures on all produce and NYSG produce by HPNAP contractors.

Setting:

New York State.

Outcome Measures:

The proportion of dollars spent on NYSG produce during 2011-2012 (preintervention) and 2013-2014 (postintervention) was compared between HPNAP food bank contractors (recipients of stimulus money, n = 8) and non–food bank contractors (nonrecipients, n = 34) using nonparametric methods.

Results:

The HPNAP Locally Grown Produce Initiative was associated with an increased proportion of NYSG produce spending by food bank contractors that received a fiscal stimulus 1 year later. Upstate food banks had the largest increase (median 31.6%) among all HPNAP contractors.

Conclusion:

The results of this study revealed that the Locally Grown Produce Initiative fiscal stimulus had a positive, year-long and statewide effect on the proportion of expenditure on NYSG produce by food banks. We hope that the initial success seen in New York State may encourage other states to adopt similar initiatives in future.
Leadership Perceptions of Endgame Strategies for Tobacco Control in California
Authors: Smith Elizabeth A. , McDaniel Patricia A. , Malone Ruth E.
Published: March 2018

Objective:

To explore the perspectives of key stakeholders regarding advancement of the tobacco endgame in California.

Design:

Interviews and focus groups exploring participants' knowledge of the tobacco endgame concept, their reactions to 4 endgame policy proposals (banning tobacco sales, registering smokers, retailer reduction, and permanently prohibiting tobacco sales to all those born after a certain year [“tobacco-free generation”]), and policy priorities and obstacles.

Participants:

Interviews with 11 California legislators/legislative staff members, 6 leaders of national tobacco control organizations, and 5 leaders of California-based organizations or California subsidiaries of national organizations. Focus groups (7) with professional and volunteer tobacco control advocates in Northern, Southern, and Central California.

Results:

Advocates were more familiar with the endgame concept than legislators or legislative staff. All proposed endgame policies received both support and opposition, but smoker registration and banning tobacco sales were the least popular, regarded as too stigmatizing or too extreme. The tobacco-free generation and retailer-reduction policies received the most support. Both were regarded as politically feasible, given their focus on protecting youth or regulating retailers and their gradual approach. Concerns raised about all the proposals included the creation of black markets and the potential for disparate impacts on disadvantaged communities.

Conclusion:

Participants' willingness to support novel tobacco control proposals suggests that they understand the magnitude of the tobacco problem and have some appetite for innovation despite concerns about specific endgame policies. A preference for more gradual approaches suggests that taking incremental steps toward an endgame policy goal may be the most effective strategy.
Memory encoding of syntactic information involves domain-general attentional resources. Evidence from dual-task studies
Authors: Heyselaar Evelien , Segaert Katrien
Published: March 2018

We investigate the type of attention (domain-general or language-specific) used during syntactic processing. We focus on syntactic priming: In this task, participants listen to a sentence that describes a picture (prime sentence), followed by a picture the participants need to describe (target sentence). We measure the proportion of times participants use the syntactic structure they heard in the prime sentence to describe the current target sentence as a measure of syntactic processing. Participants simultaneously conducted a motion-object tracking (MOT) task, a task commonly used to tax domain-general attentional resources. We manipulated the number of objects the participant had to track; we thus measured participants’ ability to process syntax while their attention is not-, slightly-, or overly-taxed. Performance in the MOT task was significantly worse when conducted as a dual-task compared to as a single task. We observed an inverted U-shaped curve on priming magnitude when conducting the MOT task concurrently with prime sentences (i.e., memory encoding), but no effect when conducted with target sentences (i.e., memory retrieval). Our results illustrate how, during the encoding of syntactic information, domain-general attention differentially affects syntactic processing, whereas during the retrieval of syntactic information domain-general attention does not influence syntactic processing.
Metagenomic assembly of new (sub)arctic Cyanobacteria and their associated microbiome from non-axenic cultures
Authors: Cornet Luc , Bertrand Amandine R. , Hanikenne Marc , Javaux Emmanuelle J. , Wilmotte Annick , Baurain Denis
Published: March 2018

Cyanobacteria form one of the most diversified phylum of Bacteria. They are important ecologically as primary producers, for Earth evolution and biotechnological applications. Yet, Cyanobacteria are notably difficult to purify and grow axenically, and most strains in culture collections contain heterotrophic bacteria that were likely associated to Cyanobacteria in the environment. Obtaining cyanobacterial DNA without contaminant sequences is thus a challenging and time-consuming task. Here, we deploy a metagenomic pipeline that enables the easy recovery of high-quality genomes from non-axenic cultures. We tested this pipeline on 17 cyanobacterial cultures from the BCCM/ULC public collection and generated novel genome sequences for 15 arctic or subarctic strains, of which 14 early-branching organisms that will be useful for cyanobacterial phylogenomics. In parallel, we managed to assemble 31 co-cultivated bacteria from the same cultures and showed that they mostly belong to Bacteroidetes and Proteobacteria, some of them being very closely related in spite of geographically distant sampling sites.

Importance

Complete genomes of cold-adapted Cyanobacteria are underrepresented in databases, due to the difficulty to grow them axenically. In this work, we report the genome sequencing of 12 (sub)arctic and 3 temperate Cyanobacteria, along with 21 Proteobacteria and 5 Bacteroidetes recovered from their microbiome. Following the use of a state-of-the-art metagenomic pipeline, 12 of our new cyanobacterial genome assemblies are of high-quality, which indicates that even non-axenic cultures can yield complete genomes suitable for phylogenomics and comparative genomics. From a methodological point of view, we investigate the fate of SSU rRNA (16S) genes during metagenomic binning and observe that multi-copy rRNA operons are lost because of higher sequencing coverage and divergent tetranucleotide frequencies. Moreover, we devised a measure of genomic identity to compare metagenomic bins of different completeness, which allowed us to show that Cyanobacteria-associated bacteria can be highly related in spite of considerable distance between collection points.
Quantification of DNA samples by Ethidium Bromide Spot Technique
Authors: Zhao Jessica , Zhao Julian , Cummins Antoine , Gonzalez Tiffany , Axler-DiPerte Grace , Camenares Devin
Published: March 2018

Accurate and quick determination of DNA concentration is critical for the assembly of synthetic constructs, as well as a multitude of other experiments. We sought to optimize an under-utilized and inexpensive approach for determining DNA concentration: a spotting technique that uses the intercalating dye Ethidium Bromide. This technique does not require specialized equipment such as a spectrophotometer, but instead relies on visualization of dye-DNA complex fluorescence when excited by UV light. We modelled and tested a range of parameters for dye concentration and spot size, finding that 15uL spots with 1.0ug/mL Ethidium Bromide produced the most reliable standard curve. More importantly, we hope that our approach can help other labs optimize this protocol for their own experimental setup. Adoption of this technique may help enable development of iGEM teams in resource limited environments and laboratories which do not or cannot employ a satisfactory method for determining DNA concentration.

Financial Disclosure

We obtained funding support from Canon Solutions America, and indirect support for this work through the CUNY Research Scholars Program. However, the funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing Interests

The authors have declared that no competing interests exist.

Ethics Statement

N/A

Data Availability

Yes – all data are fully available without restriction. The data can be found in the associated supplementary materials.

Article Tags

DNA, Ethidium Bromide, EtBr, Concentration, Method, UV, Gibson Assembly

Header Statement

This work was assessed during the iGEM/PLOS Realtime Peer Review Jamboree on 23rd February 2018 and has been revised in response to the reviewers. Responses to Reviewers, and supplementary information (including Fig. S1) are available as separate files.
Neural Data Visualization for Scalable and Generalizable Single Cell Analysis
Authors: Cho Hyunghoon , Berger Bonnie , Peng Jian
Published: March 2018

Single-cell RNA sequencing is becoming effective and accessible as emerging technologies push its scale to millions of cells and beyond. Visualizing the landscape of single cell expression has been a fundamental tool in single cell analysis. However, standard methods for visualization, such as t-stochastic neighbor embedding (t-SNE), not only lack scalability to data sets with millions of cells, but also are unable to generalize to new cells, an important ability for transferring knowledge across fast-accumulating data sets. We introduce net-SNE, which trains a neural network to learn a high quality visualization of single cells that newly generalizes to unseen data. While matching the visualization quality of t-SNE on 14 benchmark data sets of varying sizes, from hundreds to 1.3 million cells, net-SNE also effectively positions previously unseen cells, even when an entire subtype is missing from the initial data set or when the new cells are from a different sequencing experiment. Furthermore, given a “reference” visualization, net-SNE can vastly reduce the computational burden of visualizing millions of single cells from multiple days to just a few minutes of runtime. Our work provides a general framework for newly bootstrapping single cell analysis from existing data sets.
Cortical thickness in right frontal and left lingual gyri differentially mediate episodic memory for spatial contextual details across the adult lifespan
Authors: Swierkot A. , Rajah M. N.
Published: March 2018

Healthy aging is associated with declines in episodic memory and with widespread cortical thinning. These parallel declines suggest that age-related changes in cortical thickness may contribute to episodic memory decline with age. The current study uses a cross-sectional study design to examine whether regional cortical thickness mediates the relationship between age and episodic memory, as measured by a context memory task for faces. Mediation and conditional mediation models were tested using bootstrapping in order to determine how age-associated changes in regional cortical thickness mediated age-associated changes in performance on the context memory task. We observed that right superior frontal cortical thickness conditionally mediated spatial context memory only in middle-aged and older adults; and right caudal middle frontal cortical thickness conditionally mediated context memory only in older adults. Left lingual cortical thickness mediated spatial context memory across the adult lifespan, but this effect was most evident at midlife. Right parahippocampal cortical thickness mediated context memory, independent of age. We conclude that our cortical thickness results were generally consistent with the posterior-to-anterior shift in aging hypothesis (Davis et al., 2008) for episodic memory.
USP9X regulates DVL2 ubiquitylation to determine WNT pathway specification
Authors: Nielsen Casey P. , Jernigan Kristin K. , Diggins Nicole L. , Webb Donna J. , MacGurn Jason A.
Published: March 2018

The WNT signaling network is comprised of multiple receptors that relay various input signals via distinct transduction pathways to execute multiple complex and context-specific output processes. Integrity of the WNT signaling network relies on proper specification between canonical and non-canonical pathways, which presents a regulatory challenge given that several signal transducing elements are shared between pathways. Here, we report that USP9X, a deubiquitylase, and WWP1, an E3 ubiquitin ligase, interact physically to regulate a ubiquitin switch on DVL2, a WNT signaling protein. Our findings indicate that USP9X-mediated deubiquitylation of DVL2 is required for canonical WNT activation, while DVL2 ubiquitylation promotes its localization to actin-rich projections and increased cellular motility. We propose that a WWP1-USP9X axis regulates a ubiquitin switch on DVL2 that specifies its participation in either canonical WNT or WNT-PCP pathways. These findings have important implications for therapeutic targeting of USP9X in human cancer.
Microstate EEGlab toolbox: An introductory guide
Authors: Poulsen Andreas Trier , Pedroni Andreas , Langer Nicolas , Hansen Lars Kai
Published: March 2018

EEG microstate analysis offers a sparse characterisation of the spatio-temporal features of large-scale brain network activity. However, despite the concept of microstates is straight-forward and offers various quantifications of the EEG signal with a relatively clear neurophysiological interpretation, a few important aspects about the currently applied methods are not readily comprehensible. Here we aim to increase the transparency about the methods to facilitate widespread application and reproducibility of EEG microstate analysis by introducing a new EEGlab toolbox for Matlab. EEGlab and the Microstate toolbox are open source, allowing the user to keep track of all details in every analysis step. The toolbox is specifically designed to facilitate the development of new methods. While the toolbox can be controlled with a graphical user interface (GUI), making it easier for newcomers to take their first steps in exploring the possibilities of microstate analysis, the Matlab framework allows advanced users to create scripts to automatise analysis for multiple subjects to avoid tediously repeating steps for every subject. This manuscript provides an overview of the most commonly applied microstate methods as well as a tutorial consisting of a comprehensive walk-through of the analysis of a small, publicly available dataset.
Onset of differentiation is posttranscriptionally controlled in adult neural stem cells
Authors: Baser Avni , Dang Yonglong , Skabkin Maxim , Gülcüler Balta Gülce S. , Kalamakis Georgios , Kleber Susanne , Göpferich Manuel , Schefzik Roman , Santos Lopez Alejandro , Llorens Bobadilla Enric , Schultz Carsten , Fischer Bernd , Martin-Villalba Ana
Published: March 2018

The contribution of posttranscriptional regulation of gene expression to neural stem cell differentiation during tissue homeostasis remains elusive. Here we show highly dynamic changes in protein synthesis along differentiation of stem cells to neurons in vivo. Examination of individual transcripts using RiboTag mouse models reveals that neural stem cells efficiently translate abundant transcripts, whereas translation becomes increasingly controlled with the onset of differentiation. Stem cell generation of early neuroblasts involves translational repression of a subset of mRNAs including the stem cell-identity factors Sox2 and Pax6 as well as translation machinery components. In silico motif analysis identifies a pyrimidine-rich motif (PRM) in this repressed subset. A drop in mTORC1 activity at the onset of differentiation selectively blocks translation of PRM-containing transcripts. Our data uncovers how a drop in mTORC1 allows robust simultaneous posttranscriptional repression of key stem cell identity-factors and translation-components and thereby stemness exit and migration.
Genomic characterization of six virus-associated cancers identifies changes in the tumor microenvironment and altered genetic programming
Authors: Varn Frederick S. , Wang Yue , Cheng Chao
Published: March 2018

Viruses affect approximately 20% of all human cancers and express immunogenic proteins that make these tumor types potent targets for immune checkpoint inhibitors. In this study, we apply computational tools to The Cancer Genome Atlas and other datasets to define how virus infection shapes the tumor microenvironment and genetic architecture of 6 virus-associated tumor types. Across cancers, the cellular composition of the tumor microenvironment varied based on viral status, with infected tumors often exhibiting increased infiltration of cytolytic cell types. Analyses of the infiltrating T cell receptor repertoire revealed that Epstein-Barr virus was associated with decreased diversity in multiple cancers, suggesting an antigen-driven immune response. Tissue-specific gene expression signatures capturing these virus-induced transcriptomic changes successfully predicted virus status in independent datasets and were associated with both immune- and proliferation-related features that were predictive of prognosis. The analyses presented suggest viruses have distinct effects in different tumors with implications for immunotherapy.
A novel, biologically-informed polygenic score reveals role of mesocorticolimbic insulin receptor gene network on impulsivity and addiction
Authors: McCracken Kathryn , Hari Dass Shantala A. , Pokhvisneva Irina , Chen Lawrence M. , Garg Elika , Nguyen Thao T. T. , Yaqubi Moein , McEwen Lisa M. , MacIsaac Julie L. , Diorio Josie , Kobor Michael S. , O’Donnell Kieran J. , Meaney Michael J. , Silveira Patricia P.
Published: March 2018

Importance

Activation of brain insulin receptors occurs on mesocorticolimbic regions, modulating reward sensitivity and inhibitory control. Variations in the functioning of this mechanism likely associate with individual differences in the risk for related psychopathologies (attention-deficit hyperactivity disorder, addiction), an idea that agrees with the high comorbidity between insulin resistant states and psychiatric conditions. While genetic studies comprise an interesting tool to explore neurobiological mechanisms in community samples, the conventional genome-wide association studies and polygenic risk score methodologies completely ignore the fact that genes operate in networks, and code for precise biological functions in specific tissues.

Objective

We propose a novel, biologically informed genetic score reflecting the mesocorticolimbic insulin receptor-related gene network, and investigate if it predicts dopamine-related psychopathology (impulsivity and addiction) in community samples.

Design

Birth cohort (Maternal Adversity, Vulnerability and Neurodevelopment, MAVAN) and adult cohort (Study of Addiction, Genes and Environment, SAGE).

Setting

General community.

Participants

212 4-year-old children (MAVAN), and 1626 adults (SAGE).

Exposure

The biologically informed, mesocorticolimbic specific, insulin receptor polygenic score was created based on levels of co-expression with the insulin receptor in striatum and prefrontal cortex, and calculated in the two samples using the genotype data (Psychip/Psycharray).

Main outcome

childhood impulsivity in the Information Sampling task, and risk for early addiction onset.

Results

The insulin receptor polygenic score showed improved prediction of childhood impulsivity in boys and risk for early addiction onset in males in comparison to conventional polygenic risk scores for attention-deficit hyperactivity disorder or addiction.

Conclusions and relevance

This novel genomic approach reveals insulin action as a relevant biological process involved in the risk for dopamine-related psychopathology.

Key points

Question

Considering the modulation of mesocorticolimbic dopaminergic pathways by insulin through the action on its receptors (IR), we investigated if a novel, region specific polygenic score on the IR-related gene network (ePRS-IR) is associated with dopamine-related behaviors (impulsivity and addiction).

Findings

The ePRS-IR showed improved prediction of childhood impulsivity and risk for early addiction onset in comparison to conventional polygenic risk scores for ADHD or addiction.

Meaning

This novel genomic approach reveals insulin action as a biological process involved in the risk for dopamine-related psychopathology.
Hydrocerussite-related minerals and materials: structural principles, chemical variations and infrared spectroscopy
Authors: Siidra Oleg , Nekrasova Diana , Depmeier Wulf , Chukanov Nikita , Zaitsev Anatoly , Turner Rick
Published: March 2018

White lead or basic lead carbonate, 2PbCO3·Pb(OH)2, the synthetic analogue of hydrocerussite Pb3(OH)2(CO3)2, has been known since antiquity as the most frequently used white paint. A number of different minerals and synthetic materials compositionally and structurally related to hydrocerussite have been described within the last two decades. Herein, a review is given of general structural principles, chemical variations and IR spectra of the rapidly growing family of hydrocerussite-related minerals and synthetic materials. Only structures containing a hydroxo- and/or oxo-component,i.e.which are compositionally directly related with hydrocerussite and `white lead', are reviewed in detail. An essential structural feature of all the considered phases is the presence of electroneutral [PbCO3]0cerussite-type layers or sheets. Various interleaved sheets can be incorporated between the cerussite-type sheets. Different sheets are stacked into two-dimensional blocks separated by the stereochemically active 6s2lone electron pairs on Pb2+cations. Minerals and synthetic materials described herein, together with a number of still hypothetical members, constitute a family of modular structures. Hydrocerussite, abellaite and grootfonteinite can be considered to constitute a merotype family of structures. The remaining hydrocerussite-related structures discussed are built on similar principles, but are more complex. Structural architectures of somersetite and slag phase from Lavrion, Attica, Greece, are unique for oxysalt mineral structures in general. Thus, the whole family of hydrocerussite-related phases can be denoted as a plesiotype family of modular structures. The crystal structures of hydrocerussite from Merehead quarry, Somerset, England, and of its synthetic analogue, both determined from single crystals, are reported here for the first time. The results of the infrared (IR) spectroscopy show that this method is useful for distinguishing several different minerals related to hydrocerussite and their synthetic analogues.
Crystal structure, phase transition and structural deformations in iron borate (Y0.95Bi0.05)Fe3(BO3)4in the temperature range 90–500 K
Authors: Smirnova Ekaterina S. , Alekseeva Olga A. , Dudka Alexander P. , Artemov Vladimir V. , Zubavichus Yan V. , Gudim Irina A. , Bezmaterhykh Leonard N. , Frolov Kirill V. , Lyubutin Igor S.
Published: March 2018

An accurate X-ray diffraction study of (Y0.95Bi0.05)Fe3(BO3)4single crystals in the temperature range 90–500 K was performed on a laboratory diffractometer and used synchrotron radiation. It was established that the crystal undergoes a diffuse structural phase transition in the temperature range 350–380 K. The complexity of localization of such a transition over temperature was overcome by means of special analysis of systematic extinction reflections by symmetry. The transition temperature can be considered to beTstr≃ 370 K. The crystal has a trigonal structure in the space groupP3121 at temperatures of 90–370 K, and it has a trigonal structure in the space groupR32 at 375–500 K. There is one type of chain formed by the FeO6octahedra along thecaxis in theR32 phase. When going into theP3121 phase, two types of nonequivalent chains arise, in which Fe atoms are separated from the Y atoms by a different distance. Upon lowering the temperature from 500 to 90 K, a distortion of the Y(Bi)O6, FeO6, B(2,3)O3coordination polyhedra is observed. The distances between atoms in helical Fe chains and Fe—O—Fe angles change non-uniformly. A sharp jump in the equivalent isotropic displacement parameters of O1 and O2 atoms within the Fe—Fe chains and fluctuations of the equivalent isotropic displacement parameters of B2 and B3 atoms were observed in the region of structural transition as well as noticeable elongation of O1, O2, B2, B3, Fe1, Fe2 atomic displacement ellipsoids. It was established that the helices of electron density formed by Fe, O1 and O2 atoms may be structural elements determining chirality, optical activity and multiferroicity of rare-earth iron borates. Compression and stretching of these helices account for the symmetry change and for the manifestation of a number of properties, whose geometry is controlled by an indirect exchange interaction between iron cations that compete with the thermal motion of atoms in the structure. Structural analysis detected these changes as variations of a number of structural characteristics in thecunit-cell direction, that is, the direction of the helices. Structural results for the local surrounding of the atoms in (Y0.95Bi0.05)Fe3(BO3)4were confirmed by EXAFS and Mössbauer spectroscopies.
Revisiting theI{\overline {\bf 1}} structures of high-temperature Ca-rich plagioclase feldspar – a single-crystal neutron and X-ray diffraction study
Authors: Jin Shiyun , Wang Xiaoping , Xu Huifang
Published: March 2018

The I{\overline 1} structures of four natural Ca-rich plagioclase feldspars formed at high temperature were analysed using single-crystal neutron and X-ray diffraction. The neutron time-of-flight Laue diffractometer at the ORNL Spallation Neutron Source (Tennessee, USA) combined with a single-crystal X-ray diffraction instrument were able to reveal some new details about these already intensively studied structures. The split oxygen atoms refined from the neutron diffraction data show the underlying mechanism of Ca–Na ordering and the anisotropic P{\overline 1} ordering along thec-axis. The compositional ranges covered by the samples studied are quite rare for I{\overline 1} structures. The incommensurately modulatede2 structure of some plagioclase samples can easily be confused with an I{\overline 1} structure from the diffraction pattern, which puts some previously published I{\overline 1} structures into question. An incomplete phase diagram for Ca-rich plagioclase feldspar is proposed to explain the rarity of the I{\overline 1} structure in this compositional range, and a time–temperature–transformation diagram for the composition ∼An66is provided accordingly.
Phase transitions in ferroelectric 4-aminopyridinium tetrachloroantimonate(III) – revisited
Authors: Gągor Anna
Published: March 2018

New X-ray diffraction studies on the crystal structure of ferroelectric [4-NH2C5H4NH][SbCl4] indicate that in the broad temperature range from 240 to 304 K covering the three intermediate phases, the crystal structure is modulated. Phase II is incommensurately modulated with modulation vectorq= βb*, β varying from 0.60 to 0.66 and monoclinicC2/c(0β0)s0 superspace group. Ferroelectric phase III is commensurate withq= 2\over 3b*andCc(0β0)0 symmetry. Polar phase IV is incommensurately modulated with β varying from 0.66 to 0.70 andCc(0β0)0 superspace group. In all phases only first-order satellites are observed along theb*direction. Two types of periodic deformation are present in the structure of modulated phases. The 4-aminopyridinium cations are subjected to occupation modulation whereas [SbCl4]−nchains are displacively modulated. The paraelectric–ferroelectric phase transition is an example of the incommensurate–commensurate transition of the lock-in type. A new mechanism for this transformation is proposed.
Surface embeddings of the Klein and the Möbius–Kantor graphs
Authors: Pedersen Martin Cramer , Delgado-Friedrichs Olaf , Hyde Stephen T.
Published: March 2018

This paper describes an invariant representation for finite graphs embedded on orientable tori of arbitrary genus, with working examples of embeddings of the Möbius–Kantor graph on the torus, the genus-2 bitorus and the genus-3 tritorus, as well as the two-dimensional, 7-valent Klein graph on the tritorus (and its dual: the 3-valent Klein graph). The genus-2 and -3 embeddings describe quotient graphs of 2- and 3-periodic reticulations of hyperbolic surfaces. This invariant is used to identify infinite nets related to the Möbius–Kantor and 7-valent Klein graphs.
Addressing operational constraints through Contextual Leadership at a KZN Public Hospital
Authors: Zungu Sibongile , Mathu Kenneth M. , Scheepers Caren
Published: March 2018

Subject area

Organizational Development; Change Management; Leadership; Healthcare Management Operations; Supply Chain.

Study level/applicability

MBA; Masters in Healthcare Management; Post-graduate Diploma in Leadership; MPhil in Strategic Leadership.

Case overview

On April 16, 2016, the CEO of Prince Mshiyeni Memorial hospital, Kwa-Zulu Natal, South Africa, Dr Sandile Tshabalala reflected as he drove through the winding hills of the Cato range. In recent years, the hospital had been a subject of negative publicity with horror stories about patients collapsing while waiting for their medication at one of Durban’s largest hospitals. The case features a number of stakeholders and their demands and even threats. Contextual leadership intelligence requires accurate identification of relevant stakeholders and then involvement in solutions. The case illustrates how these demands had been listened to and how the stakeholders had been involved in finding solutions. A remarkable solution was to realize that the bottleneck at the pharmacy was actually caused by a problem early on in the process, for example, the late start of administrative staff who had to submit patients. A further solution was to utilize the primary health care clinics and even churches for dispensing chronic medicine.

Expected learning outcomes

Gaining insight and foresight into the operations and supply chain dilemmas in public health care. Developing understanding of the impact of various stakeholders in the healthcare sector. Understanding buy-in when leading change. Acquiring contextual leadership intelligence in the public health environment.

Supplementary materials

Teaching Notes are available for educators only. Please contact your library to gain login details or email support@emeraldinsight.com to request teaching notes.

Subject code

CSS 7: Management Science.
Pacari Chocolate: preserving biodiversity, living without regret
Authors: Lupton Nathaniel C. , Sánchez Angélica , Kerpel Annette
Published: March 2018

Subject area

Emerging Markets.

Study level/applicability

Undergraduate, Masters.

Case overview

Pacari Chocolate is the flagship brand of SKS Farms CIA Ltda., located in Quito, Ecuador. The company specializes in organic chocolate production which it sells in Ecuador and exports to other Latin American, European and North American markets. The company began operation in 2002, founded by Carla Barbotó and her husband Santiago Peralta. Carla is the Director of SKS and Santiago is General Manager. The case is set just after Santiago negotiated a deal to supply Emirates Airlines with mini bars to be distributed to flight passengers. Santiago is excited about this new deal, which will provide a new revenue stream, enhance brand image and potentially create new customers. Carla and Santiago pursue excellence with their products, as evidenced by over 160 awards, many globally recognized. However, their mission is also very much social in that they seek to improve the lives of Andean farmers, indigenous peoples and broader Ecuadorean society. The principle author uses this case in a course on innovative approaches to engaging emerging market opportunities, in which shared (social + economic) value and the formation of strong national industries are key outcomes, to be addressed through complementary market and non-market entrepreneurship strategies.

Expected learning outcomes

Expected learning outcomes are as follows: to identify the contextual challenges faced by an emerging market firm, and explain what must be done to overcome them; to identify the role of a firm in developing a national competency in an agricultural product industry; to demonstrate the creation of “shared value” and examine how the social mission of a company can reinforce and sustain its economic value creating activities; and to generate and evaluate options for developing international markets when a firm has limited resources to invest in marketing activities.

Supplementary materials

Teaching Notes are available for educators only. Please contact your library to gain login details or email support@emeraldinsight.com to request teaching notes.

Subject code

CSS 3: Entrepreneurship.
Macro-economic index effect on house prices in China
Authors: Li Zheyu , Razali Muhammad Najib , Gholipour Fereidouni Hassan , Mohd. Adnan Yasmin
Published: March 2018

Purpose

The purpose of this study is to estimate different data models on house prices using statistical models and the variables which are controlled by real estate policy.

Design/methodology/approach

This study used several statistical techniques, such as Vector auto-regression (VAR), Johansen co-integration and variance decomposition, which aim to assess the significant effect of macroeconomic factors on Chinese house prices.

Findings

The results show that land supply and other variables have negative effects on house prices. The results also indicate that financial mortgages for real estate have positive effects on house prices and the area of vacant houses as well as the area of housing sold.

Research limitations/implications

This study only covers three cities in China because of limitations of data for other cities.

Originality/value

This study proposes policy suggestions according to the empirical results obtained.
Transcendence/religion to immanence/nonreligion in assisted dying
Authors: Beaman Lori G. , Steele Cory
Published: March 2018

Purpose

The purpose of this paper is to draw attention to the ways in which the Supreme Court of Canada has shifted away from transcendent/religious to nonreligious conceptualizations of assisted dying.

Design/methodology/approach

A discourse analysis of a Supreme Court of Canada case on assisted dying and the facta of the 26 associated interveners.

Findings

The research points to a shift away from religious to nonreligious understandings in the way the Court conceptualizes suffering, pain, illness and assisted dying.

Originality/value

This paper contributes to the understanding of nonreligion as a social phenomenon.
The direct and indirect effect of cash transfers: the case of Indonesia
Authors: Yusuf Arief Anshory
Published: March 2018

Purpose

The purpose of this paper is to analyze the impact of unconditional cash transfers in Indonesia on poverty and inequality while, unlike much of the previous literature on the welfare impact of such transfers, acknowledging that they will have both a direct effect and an economy-wide effect on the national economy.

Design/methodology/approach

The methodology used is a Computable General Equilibrium (CGE) model of the Indonesian economy. The unique feature of this model, which is very relevant in this study, is the disaggregation of households by expenditure classes; this allows for precise estimation of the distributional impact and poverty incidence.

Findings

The results suggest that, despite a large reduction in poverty, particularly in rural areas, such transfers reduce the Indonesian GDP, especially if domestically financed through increasing the value added tax of all commodities. However, the GDP reduction can be reduced by approximately half when cash transfers are financed by reducing the distortionary fuel subsidy. Moreover, cash transfers financed by reducing the fuel subsidy also reduce inequality by much more than otherwise. Various extents of the distribution of the transfers are compared, from giving them to the poorest 10 percent to distributing them equally to all households. The benefit of the transfers, in terms of reduced poverty and inequality, is found to be smaller when the author extends the beneficiaries toward the non-poor, although the economy-wide cost, in terms of the reduced GDP, is smaller.

Research limitations/implications

The CGE model used in this model is a comparative-static model that does not explicitly model the time dimension, i.e. how the impact of the transfers evolves over time. This is important if we want to know the timing of the transfers and how and when they are translated into impacts.

Practical implications

To reduce the contractionary effect of cash transfers program, government/policy makers should carefully look for appropriate financing such as from removing subsidy with pre-existing distortions like fuel subsidies.

Social implications

Government needs to carefully design cash transfers to minimize the negative indirect (economy-wide) implication for the national economy and to make sure that the transfers reach the targeted beneficiaries.

Originality/value

Few previous studies have acknowledged the indirect economy-wide effect in analyzing the impact of cash transfers. To the author’s knowledge, this has never been done before for Indonesia. Unlike previous studies, this paper is unique as it contains sensitivity analysis on how transfers can be mistargeted and reach the non-poor and looks at the implications not only for poverty and inequality but also for the rest of the economy.
Education and teenage childbirth in Uganda
Authors: Makate Marshall , Makate Clifton
Published: March 2018

Purpose

The role of increased schooling on teenage childbirth has been expansively studied especially in developed countries. However, caveats remain in the case of low-income countries especially Sub-Saharan Africa. The purpose of this paper is to ascertain the impact of increased schooling on the probability of first childbirth at 15 years or younger, 16-17, 18-19, and 20 years or older, in the important context of Uganda – a country with one of the highest adolescent fertility rates in Africa.

Design/methodology/approach

The empirical analysis uses recent data from the nationally representative Demographic and Health Survey for Uganda conducted in 2011. The authors then adopt a fuzzy regression discontinuity design, estimated using instrumental variables techniques that exploit the exogenous change in schooling impelled by the universal primary education policy enacted in 1997 in Uganda. The empirical approach compares the fertility outcomes for women born in 1984-1992 (i.e. exposed to the policy) to those born in 1973-1981 (i.e. non-exposed).

Findings

The authors find that a one-year increase in schooling lowers the probability of first childbirth at age the age of 15 years or younger, 16-17, 18-19, and 20 years or older by nearly 8.2, 9.2, 9.4, and 9.5 percentage points, respectively. Also, pathways through which education impacts teenage motherhood included information access through the media, increased literacy, prenatal care utilization, marital status, and unhealthy sexual behavior.

Originality/value

The paper uses nationally representative survey data to scrutinize the causal influence of schooling on the probability of first childbirth using the 1997 universal primary education in Uganda as a natural experiment to identify the impact of schooling. The study recommends that expanding primary schooling opportunities for girls may be an effective strategy toward accelerated reductions in teenage fertility in Uganda.
Surface roughness effects on point contact elastohydrodynamic lubrication in linear rolling guide with fractal surface topographies
Authors: Li Linlin , Yang Jiajun
Published: March 2018

Purpose

The purpose of this paper is to study the effects of surface roughness on the lubrication performances of the linear rolling guide, which provides theoretical guidance for its lubrication design.

Design/methodology/approach

The two-variable Weierstrass–Mandelbrot function is used to represent the random and multi-scale characteristics of the rough surface topography. The elastohydrodynamic lubrication (EHL) model of contact between the steel ball and raceway is built. The full numerical solutions of the pressure and film thickness are obtained by using the multi-grid technique.

Findings

The presence of surface roughness can cause the random fluctuations of the pressure and film thickness, and the fluctuations can become more dramatic for the rougher surfaces. It is also found that the film characteristics can be influenced significantly by the working conditions, such as the load, velocity and ambient viscosity of lubricants.

Originality/value

Characterization of surface topographies regarding EHL problems in the past studies cannot reflect random and multi-scale characteristics. In this paper, the fractal-based method is introduced to analysis of the point-contact micro-EHL. It reveals the mechanism and law of contact lubrication influenced by the fractal surface roughness and enriches the lubrication principle and method of the linear rolling guide.
Effect of laser surface texturing on tribological properties of polyimide composites in the application of traveling wave rotary ultrasonic motor
Authors: Liu Xiaoliang , Zhao Gai , Qiu Jinhao
Published: March 2018

Purpose

The purpose of this paper is to investigate the effect of laser surface texturing on the tribological properties of polyimide composites and the output performance of traveling wave rotary ultrasonic motor.

Design/methodology/approach

The surface texturing on polyimide composites specimens were fabricated by laser ablation process of different dimple densities, and then the tribological properties were tested by a flat-on-flat tribometer under dry conditions. Finally, the output performance of the traveling wave rotary ultrasonic motor was tested to verify the effectiveness of dimples surface texturing.

Findings

The results show that surface texturing can greatly enhance the friction coefficient of contact interface, especially the specimen with a dimple density of 7.06 per cent exhibited the highest friction coefficient among the specimens. When the input voltage is 500 V, the output power, locked-rotor torque and output torque of ultrasonic motor with textured PI of 7.06 per cent dimple density as friction material at the speed of 100 r/min increased by 13.8, 19 and 12.8 per cent compared to that of the untextured PTFE, respectively. When the ultrasonic motor reverses, the output performance is increased by 20.9, 40.3 and 17.7 per cent, respectively.

Originality/value

Surface texturing is an effective way to improve the friction behavior of polyimide composites and then correspondingly enhance the energy conversion efficiency and output performance of the traveling wave rotary ultrasonic motor.
Evaluation of parameters for application of Laser Surface Texturing (LST) in tooling for the sheet-metal forming process
Authors: Taha-Tijerina José Jaime , Garza GerardoTadeo , Maldonado-Cortés Demófilo
Published: March 2018

Purpose

The purpose of this paper is to evaluate the effects of microcavities, diameter and depth, in tribological performance, of the application of laser surface texturing (LST) and LST gradient (LSTG) techniques, to understand and define the critical parameters of these techniques in sheet-metal forming tools.

Design/methodology/approach

The paper studies the effect of studied critical parameters of LST and LSTG techniques, on block-on-ring configuration for tribology evaluation. Experimental design parameters for LST and LSTG are proposed and evaluated for the best tribology performance (COF and wear).

Findings

The results show that the application of optimized LST process could represent a 42 per cent improvement on the COF and up to 86 per cent enhancement in the COF results for the LSTG application.

Practical implications

The results show that LST and LSTG techniques present significant positive effects on the tribological properties of sheet-metal forming materials.

Originality/value

This demonstrates the potential of LST technique applied to industrial tooling, and the LSTG pattern which further increases the benefits obtained with the LST technique, particularly in which friction and wear areas are critical. A response surface map is developed to determine the control parameters which are useful for the tooling design. These techniques could be used for metal-forming applications like deep-drawing, achieving an increased tool life.
Cost-efficient long-term estimation of gear oil filterability considering stresses in service
Authors: Burghardt Gero , Flórez Andrew , Jacobs Georg
Published: March 2018

Purpose

Wear particles and contaminants are known to reduce lifetime of machine elements such as roller bearings. This can be avoided through fine filtration. However, oil filterability can change in service, and in case of exceeding the maximum pressure at the filter, contaminated oil can flow through a bypass, threatening the function of the lubricated components. The purpose of this study is to provide a cost-efficient method to estimate the long-term oil fine filterability.

Design/methodology/approach

The estimation of long-term oil fine filterability takes place in two steps. In the first step, oil in its original condition is subjected to different stresses to reproduce changes experienced in service within a relatively short period of time. In the second step, the resulting oil is subjected to filterability tests. Existing test methods were adapted to produce realistic oil changes and deliver a realistic evaluation of filterability.

Findings

Oils produced using metal-catalyzed thermal-oxidative stresses and humid air are similar to real oil samples from the point of view of nuclear magnetic resonance oil analyses and filterability tests. Test conditions suitable for highly viscous gear oils were derived considering operation at low and high temperatures.

Originality/value

The test method provides an estimate of deterioration of oil filterability in service through a comparison between the filterability of oil in original condition and the filterability of an artificially produced oil.