bluuebunny/crossref_metadata_2025 huggingface dataset:
Recruiting RyRs to open in a Ca2+release unit: Single-RyR gating properties make RyR group dynamics
Authors: Gillespie D.
Published: October 2019

In cardiac myocytes, clusters of type-2 ryanodine receptors (RyR2s) release Ca2+from the sarcoplasmic reticulum (SR) via a positive feedback mechanism where fluxed Ca2+activates nearby RyRs. While the general principles of this are understood, less is known about how single-RyR gating properties define the RyR group dynamics in an array of many channels. Here, we examine this using simulations with three models of RyR gating that have identical open probabilities. The commonly-used two-state Markov gating model produces frequent, large, and long Ca2+release events because the single exponential that defines its open time (OT) and closed time (CT) distributions reproduces the experimental data poorly. In contrast, simulations that utilize complete single-channel OT and CT distributions fit with multiple exponentials produce infrequent Ca2+release events with far fewer open RyRs. Moreover, when experimentally-measured correlations between single-channel OTs and CTs are included, Ca2+release events become even smaller. This occurs because the correlations produce a small but consistent bias against recruiting more RyRs to open during the middle of a Ca2+release event, between the initiation and termination phases (which are unaltered compared to the uncorrelated simulations). Beyond the effects of full OT and CT distributions and OT/CT correlations on SR Ca2+release, we also show that Ca2+release events can terminate spontaneously without any reduction in SR [Ca2+] or physical coupling between RyRs when Ca2+flux is below a threshold value. This both supports and extends the pernicious attrition/induction decay hypothesis that SR Ca2+release events terminate below a threshold Ca2+flux.

STATEMENT OF SIGNIFICANCE

This work provides insights into RyR2-mediated Ca2+release by a cluster of RyRs interacting only via their fluxed Ca2+. It is shown that: 1) common proxies like the single-RyR open probability versus cytosolic [Ca2+] curve and mean open or closed times are poor predictors of SR Ca2+release dynamics; 2) Ca2+release events can self-terminate below a flux threshold without any physical coupling between channels; 3) commonly-used two-state Markov gating models can produce qualitatively different Ca2+release events (larger and longer) compared to simulations where complete single-channel open and closed time distributions are used; 4) correlations between a RyR’s open times and previous closed duration (and vice versa) significantly limit Ca2+release by tamping down the number of open RyRs.
4-state model for simulating kinetic and steady-state voltagedependent gating of gap junctions
Authors: Snipas M. , Kraujalis T. , Maciunas K. , Kraujaliene L. , Gudaitis L. , Verselis V. K.
Published: October 2019

Gap junction (GJ) channels, formed of connexin (Cx) proteins, provide a direct pathway for metabolic and electrical cell-to-cell communication. These specialized channels are not just passive conduits for the passage of ions and metabolites, but have been shown to gate robustly in response to transjunctional voltage, Vj, the voltage difference between two coupled cells and are regulated by various chemical factors. Voltage gating of GJs may play a physiological role, particularly in excitable cells which can exhibit large transients in membrane potential during the generation of an action potential. We present a mathematical/computational model of GJ channel voltage gating to assess properties of GJ channels that takes into account contingent gating of two series hemichannels and the distribution of Vj across each hemichannel. From electrophysiological recordings in cell cultures transfected with Cx43 and Cx45, isoforms that are expressed in cardiac tissue, data sets were fit simultaneously using global optimization. The results showed that the model is capable of describing both steady-state and kinetic properties of homotypic and heterotypic GJ channels composed of these connexins. Moreover, mathematical analyses showed that the model can be simplified to a reversible two-state system and solved analytically, using a rapid equilibrium assumption. Given that excitable cells are arranged in interconnected networks, the equilibrium assumption allows for a substantial reduction in computation time, which is useful in simulations of large clusters of coupled cells. Overall, this model can serve not just as a modeling tool, but also to provide a means of testing GJ channel gating behavior.

Significance

Gap junction (GJ) channels gate in response to transjunctional voltage which provides the capacity for dynamic regulation of intercellular coupling. Kinetic properties of GJs in modeling studies have been infrequently addressed and we present a computational model of voltage gating that can account for both kinetic and steady-state changes in junctional conductance, gj. Although GJs possess two gating mechanisms, our analysis indicates that changes in gj for each voltage polarity can be adequately described by a kinetic scheme describing a single mechanism in each of the hemichannels, suggesting functional dominance of one mechanism over a substantial voltage range. This property allowed for model simplification that can be applied for efficient simulation of sizeable cell clusters and analyses of electrophysiological data.
Antibody-Recruiting Protein-Catalyzed Capture Agents to Combat Antibiotic-Resistant Bacteria
Authors: Idso Matthew N. , Akhade Ajay Suresh , Arrieta-Ortiz Mario L. , Lai Bert T. , Srinivas Vivek , Hopkins James P. , Gomes Ana Oliveira , Subramanian Naeha , Baliga Nitin , Heath James R.
Published: October 2019

Antibiotic resistant infections are projected to cause over 10 million deaths by 2050, yet the development of new antibiotics has slowed. This points to an urgent need for methodologies for the rapid development of antibiotics against emerging drug resistant pathogens. We report on a generalizable combined computational and synthetic approach, called antibody-recruiting protein-catalyzed capture agents (AR-PCCs), to address this challenge. We applied the combinatorial PCC technology to identify macrocyclic peptide ligands against highly conserved surface protein epitopes of carbapenem-resistant Klebsiella pneumoniae, an opportunistic gram-negative pathogen with drug resistant strains. Multi-omic data combined with bioinformatic analyses identified epitopes of the highly expressed MrkA surface protein of K. pneumoniae for targeting in PCC screens. The top-performing ligand exhibited high-affinity (EC50∼50 nM) to full-length MrkA, and selectively bound to MrkA-expressing K. pneumoniae, but not to other pathogenic bacterial species. AR-PCCs conjugated with immunogens promoted antibody recruitment to K. pneumoniae, leading to phagocytosis and phagocytic killing by macrophages. The rapid development of this highly targeted antibiotic implies that the integrated computational and synthetic toolkit described here can be used for the accelerated production of antibiotics against drug resistant bacteria.
NADPH and glutathione redox link TCA cycle activity to endoplasmic reticulum stress
Authors: Gansemer Erica R. , McCommis Kyle S. , Martino Michael , King-McAlpin Abdul Qaadir , Potthoff Matthew J. , Finck Brian N. , Taylor Eric B. , Rutkowski D. Thomas
Published: October 2019

Endoplasmic reticulum (ER) stress is associated with dysregulated metabolism, but little is known about how the ER responds to metabolic activity. Here, working primarily in mouse hepatocytes, we show that decreasing the availability of substrate for the TCA cycle diminished NADPH production and attenuated ER stress in a manner that depended on glutathione oxidation. ER stress was also alleviated by impairing either TCA-dependent NADPH production or Glutathione Reductase. Conversely, stimulating TCA activity favored NADPH production, glutathione reduction, and ER stress. Validating these findings, we show that deletion of the mitochondrial pyruvate carrier, which is known to decrease TCA cycle activity and protect the liver from diet-induced injury, also diminished NADPH, elevated glutathione oxidation, and alleviated ER stress. These results provide independent genetic evidence that mitochondrial oxidative metabolism is linked to ER homeostasis. Our results demonstrate a novel pathway of communication between mitochondria and the ER, through relay of redox metabolites.
Self-assembly of multi-component mitochondrial nucleoids via phase separation
Authors: Feric Marina , Demarest Tyler G. , Tian Jane , Croteau Deborah L. , Bohr Vilhelm A. , Misteli Tom
Published: October 2019

Mitochondria contain an autonomous and spatially segregated genome. The organizational unit of their genome is the nucleoid, which consists of mitochondrial DNA (mtDNA) and associated architectural proteins. Here, we show that phase separation is the primary physical mechanism for assembly and size-control of the mitochondrial nucleoid. The major mtDNA-binding protein TFAM spontaneously phase separatesin vitrovia weak, multivalent interactions into viscoelastic droplets with slow internal dynamics. In combination, TFAM and mtDNA form multiphase, gel-like structuresin vitro, which recapitulate thein vivodynamic behavior of mt-nucleoids. Enlarged, phase-separated, yet transcriptionally active, nucleoids are present in mitochondria from patients with the premature aging disorder Hutchinson-Gilford Progeria Syndrome (HGPS) and are associated with mitochondrial dysfunction. These results point to phase separation as an evolutionarily conserved mechanism of genome organization.

Highlights

Mitochondrial genomes are organized by phase separation.

The main packaging protein TFAM and mtDNA combine to form viscoelastic, multiphase dropletsin vitro.

Mitochondrial nucleoids exhibit phase behaviorin vivo, including dynamic rearrangements and heterogenous organization.

Coalescence and enlargement of mt-nucleoids occur upon loss of mitochondrial homeostasis as well as in prematurely aged cells and are associated with mitochondrial dysfunction.
The population and evolutionary dynamics of bacteriophage: Why be temperate revisited
Authors: Chaudhry Waqas , Vega Nicole , Govindan Adithi , Garcia Rodrigo , Lee Esther , McCall Ingrid , Levin Bruce
Published: October 2019

Bacteriophages are deemed either lytic (virulent) or temperate, respectively depending on whether their genomes are transmitted solely horizontally, or both horizontally and vertically. To elucidate the ecological and evolutionary conditions under which natural selection will favor the evolution and maintenance of lytic or temperate modes of phage replication and transmission, we use a comprehensive mathematical model of the dynamics of temperate and virulent phage in populations of bacteria sensitive and resistant to these viruses. For our numerical analysis of the properties of this model, we use parameters estimated with the temperate bacteriophage Lambda, λ, it’s clear and virulent mutants, andE. colisensitive and resistant - refractory to these phages. Using batch and serial transfer population dynamic and reconstruction experiments, we test the hypotheses generated from this theoretical analysis. Based on the results of this jointly theoretical and experimental study, we postulate the conditions under which natural selection will favor the evolution and maintenance of lytic and temperate modes of phage replication and transmission. A compelling and novel prediction thisin silico,in vitro, andin plasticostudy makes is lysogenic bacteria from natural populations will be resistant-refractory to the phage for which they are lysogenic as well as lytic phage sharing the same receptors as these temperate viruses.
An Improved Recombineering Toolset for Plants
Authors: Brumos Javier , Zhao Chengsong , Gong Yan , Soriano David , Patel Arjun P. , Perez-Amador Miguel A. , Stepanova Anna N. , Alonso Jose M.
Published: October 2019

Gene functional studies often rely on the expression of a gene of interest as transcriptional and translational fusions with specialized tags. Ideally, this is done in the native chromosomal contexts to avoid potential misexpression artifacts. Although recent improvements in genome editing have made it possible to directly modify the target genes in their native chromosomal locations, classical transgenesis is still the preferred experimental approach chosen in most gene tagging studies because of its time efficiency and accessibility. We have developed a recombineering-based tagging system that brings together the convenience of the classical transgenic approaches and the high degree of confidence in the results obtained by direct chromosomal tagging using genome-editing strategies. These simple, scalable, customizable recombineering toolsets and protocols allow a variety of genetic modifications to be generated. In addition, we developed a highly efficient recombinase-mediated cassette exchange system to facilitate the transfer of the desired sequences from a bacterial artificial chromosome clone to a transformation-compatible binary vector, expanding the use of the recombineering approaches beyond Arabidopsis (Arabidopsis thaliana). We demonstrated the utility of this system by generating more than 250 whole-gene translational fusions and 123 Arabidopsis transgenic lines corresponding to 62 auxin-related genes and characterizing the translational reporter expression patterns for 14 auxin biosynthesis genes.
Synthesis and structural study of organic two-photon-absorbing cycloalkanone chromophores
Authors: Bogdanov Georgii , Tillotson John P. , Khrustalev Victor N. , Rigin Sergei , Timofeeva Tatiana V.
Published: October 2019

The three organic two-photon-absorbing cycloalkanone chromophores 2,4-bis[4-(diethylamino)benzylidene]cyclobutanone, C26H32N2O (I), 2,5-bis[4-(diethylamino)benzylidene]cyclopentanone, C27H34N2O (II), and 2,6-bis[4-(diethylamino)benzylidene]cyclohexanone, C28H36N2O (III), were obtained by a reaction between 4-(diethylamino)benzaldehyde and the corresponding cycloalkanone and were characterized by single-crystal X-ray diffraction studies, as well as density functional theory (DFT) quantum-chemical calculations. Molecules of this series have three main fragments, i.e. central acceptor (A) and two terminal donors (D
1 and D
2) and represent examples of the D
1–π–A–π–D
2 molecular design. All three compounds crystallize with two crystallographically independent molecules in the asymmetric unit (A and B) and are distinguished by the conformations of both the molecular Et2N—C6H4—C=C—C(=O)—C=C—C6H4—NEt2 backbone (arcuate or linear) and the terminal diethylamino substituents (syn- or antiperiplanar to the plane of the molecule). The central four- and five-membered rings in I and II are almost planar, and the six-membered ring in III adopts a sofa conformation. In the crystals of I–III, the two independent molecules A and B form hydrogen-bonded [A...B] dimers via intermolecular C—H...O hydrogen bonds. Furthermore, the [A...B] dimers in I are bound by intermolecular C—H...O hydrogen bonds into two-tier puckered layers, whereas in the crystals of II and III, the [A...B] dimers are stacked along the c and a axes, respectively. Taking into account the decreasing steric strain upon expanding the central ring, compound I might be more efficient as a two-photon absorption chromophore than compounds II and III, which corresponds to the results of spectroscopic studies.
Ethical work climate, organizational identification, leader-member-exchange (LMX) and organizational citizenship behavior (OCB)
Authors: Teng Chih-Ching , Lu Allan Cheng Chieh , Huang Zhi-Yang , Fang Chien-Hua
Published: October 2019

Purpose

This paper aims to propose and test a moderated mediation model examining the relationships among ethical work climate, organizational identification, leader-member-exchange (LMX) and organizational citizenship behavior (OCB).

Design/methodology/approach

Numerous regression analyses were performed using PROCESS (version 2.13), a macro for SPSS developed by Hayes (2017) to test this moderated mediation model.

Findings

The analytical results showed that organizational identification mediates the positive relationship between an ethical work climate and OCB. The analytical results also showed that LMX moderates the direct effect of ethical work climate on organizational identification and that LMX also moderates the indirect effect of ethical work climate on OCB via organizational identification.

Practical implications

This study provides numerous valuable implications for hotels to develop effective strategies to promote employees’ OCB and improve their organizational identification.

Originality/value

This study was the first attempt to propose and test a moderated mediation model that explores the relationships among ethical work climate, organizational identification, leader-member-exchange (LMX) and OCB.
Quality of work, economic crisis, and temporary employment
Authors: Bartoll Xavier , Ramos Raul
Published: October 2019

Purpose

The purpose of this paper is to analyse the association between the type of contract (temporary vs permanent) and the quality of work and its different dimensions before and after the economic crisis among Spanish employees.

Design/methodology/approach

Structural equations techniques are used to analyse the association between the type of contract and the work quality and its different dimensions before and after the crisis. Data are drawn from the 2006/2007 and 2009/2010 waves of the Encuesta de Calidad de Vida en el Trabajo.

Findings

The results show that in the two considered periods there are no differences in quality of work among male involuntary temporary workers and those with permanent contracts. However, there is an adverse widening gap across all dimensions of work quality for women in involuntary temporary employment during the economic crisis. There is also a shift among men and women in involuntary temporary employment from valuing intrinsic job quality dimension in the pre-crisis period to valuing more the work environment dimension during the crisis period.

Research limitations/implications

The analysis is limited by the continuity of variables across years and the high proportion of missing values in some variables. The obtained results cannot be interpreted in terms of causality.

Originality/value

This is the first study to consider whether the deterioration in the Spanish labour market during the crisis has affected the relationship between the type of contract and the different dimensions of the quality of work.
Tribological properties of soft/hard hybrid surface of Babbitt alloy/steel
Authors: Ni Yuquan , Dong Guangneng , Liu Qi , Wang Wei , Li Yihong
Published: October 2019

Purpose

Babbitt bush is easy to cause severe adhesive wear due to unexpected journal fall. This paper aims to improve wear resistance of Babbitt bush.

Design/methodology/approach

A soft/hard hybrid surface mircoprofile of Babbitt alloy/steel was fabricated by a technology of laser texture combined with hot-pressing. The friction and wear performances of bare steel (steel-h), Babbitt bush on steel (steel-s) and Babbitt filled in dimples of steel (steel-hs) were conducted on a ball-on-disc tester under dry and lubricated conditions.

Findings

The results showed that wettability of steel-hs was enhanced by forming soft/hard hybrid surface. Compared with steel-s, the stability of friction coefficient curve of steel-hs was improved without increasing coefficient friction. The wear resistance of steel-hs was remarkably enhanced under dry and lubricated conditions.

Originality/value

The originality of this paper is as following: to improve the tribological properties and to prolong service life of steel-s, soft/hard hybrid surface of Babbitt filled in dimples of steel substrate was successfully fabricated by laser texturing combined with hot-pressing. This paper showed that the lipophilicity of steel-hs was best among those of steel-s and steel-h. Babbitt alloy as a soft filler on dimples of steel substrate improved anti-wear of steel-s remarkably. It provides a new way to fabricate Babbitt as bushing on steel substrate.
Examining the efficiency of IT applications and bank performance
Authors: Owusu Kwateng Kwame , Agyei Joseph , Amanor Kofi
Published: October 2019

Purpose

Banking institutions have vigorously pursued the integration of information and communication technology in modern banking services. Unfortunately, empirical support demonstrating the usefulness of this undertaking has largely been scanty. The purpose of this paper is to investigate causal links between the efficiency of information technology (IT) applications and bank performance using data envelopment analysis.

Design/methodology/approach

The study adopts the DEA approach to evaluate the bank level cost and IT efficiency. The Vector Error Correction Model Granger causality tests with the forecast error variance decomposition and impulse response functions were subsequently used to examine the causal relationship between the variables.

Findings

From the findings, the bank achieved an average level of 99.1 per cent cost efficiency for the sampled period. Also the periods where the bank obtained optimal cost efficiency were in 2005, 2006 and 2014. This culminated into inefficiency scores ranging from 0 to 2.9 per cent, with 2016 financial year as the period of worst cost performance. In addition, the study found that there are both short-run and long-run relationships between IT efficiency and cost performance.

Practical implications

Management should note that any improvement to IT applications may contribute significantly to overall IT performance but for the short period, specifically the first period, by the medium to long-run period, most improvement to overall IT performance emanates from cost performance of the bank.

Originality/value

Some studies have examined the effect of IT on banks in USA and Europe. However, such studies are rare in the African context. This study will contribute to extant literature by add a new dimension of IT and bank efficiency.
Improving occupational health and safety (OHS) in construction using Training-Within-Industry method
Authors: Mollo Lesiba George , Emuze Fidelis , Smallwood John
Published: October 2019

Purpose

The manufacturing industry is a well-known source of interventions adapted to solve problems in the construction industry. The use of Training-Within-Industry (TWI) is one such intervention adopted in the construction industry to solve the construction problem relating to occupational health and safety (OHS). The objectives of TWI are to help the industry to transfer knowledge and skills from management to the employees. Therefore, the purpose of this paper was to investigate whether TWI can reduce OHS problems by promoting “learning by doing” on construction sites.

Design/methodology/approach

A case-based-research method was used to investigate the reported OHS problems in the construction industry in South Africa. The data were quantitative and qualitative in nature; the questionnaire survey, semi-structured interview and focus group interview techniques were used to collect data in the study.

Findings

The findings provide a better understanding of the human contributions influencing the behaviour of people causing accidents on construction sites. The data show that construction project leaders struggle to promote “learning by doing” because of inappropriate behaviour, lack of communication and inadequate training provided to new workers on construction sites. Also, there is significant scope for TWI deployment in construction because of the inability of supervisors or management to promote “learning by doing” on construction sites.

Practical implications

Based on the research findings, it is discovered that OHS is a serious concern in the construction industry. Therefore, the adoption of learning by doing on a construction site would help to improve OHS outcome.

Originality/value

The study highlights the need to introduce TWI on construction sites to reduce human failure causing accidents. TWI could lead to improving the knowledge- and skills-transfer programmes for construction workers in favour of better safety performance.
CSR disclosure in developing and developed countries: a comparative study
Authors: Bhatia Aparna , Makkar Binny
Published: October 2019

Purpose

This paper aims to examine and compare the nature and extent of corporate social responsibility (CSR) reporting practices of companies in developing (BRICS [Brazil, Russia, India, China and South Africa]) and developed (the USA and the UK) countries.

Design/methodology/approach

Content analysis is conducted on the annual reports and websites of 325 companies listed on stock exchanges of developing markets and of developed markets (Brazil – IBrX 100, 46 companies; Russia – Broad Market Index, 50 companies; India – BSE 100, 50 companies; China – SSE 180, 29 companies; South Africa – FTSE/JSE All Share index, 50 companies; the USA – NYSE 100, 50 companies; the UK – FTSE 100, 50 companies). Descriptives are used to calculate company wise and item wise scores.T-test analysis is applied to check for significant differences between mean scores of developing and developed countries.

Findings

The findings of the study reflect that developed countries have higher CSR disclosure scores than developing countries. Overall, mean CSR disclosure score of developed countries is 53.5%, followed by that of the developing countries at 49.4%. Developed countries take lead in CSR disclosure for all the five categories, namely, human resources, community, environment, customer and product and others. The results of independent sampleT-test suggest that mean disclosure score of developing nations is significantly different from developed nations.

Practical implications

As suggested by the results, the gap in the CSR disclosure scores between developing and developed group of countries is not an alarming one. However, developing countries should practice CSR in spirit and not just in letter. Focus should not be on just filling the pages in black and white, rather the essence of CSR should be attained for balanced development of the country. For instance, though developing country like India has high score of CSR disclosure in contrast to each of the developed country taken in the sample, yet the country is still battling with several issues such as poverty, over-population, corruption, poor standard of working conditions for the employees and environmental conservation. Sustenance should focus upon renewable sources of energy; efforts of employees should be acknowledged offering flexible working hours; consumer trust should be built by communicating authentic and accurate information about the product. As developing countries encounter several social and environmental problems, companies must endeavor to build a healthy nation keeping in mind the welfare of all stakeholders by practicing CSR.

Originality/value

This study overcomes the limitations of prior cross-country studies by taking a better representative sample with greater number of countries belonging to identifiable group of “developing” and “developed” nations and thus attempts to improve generalization and authenticity of results.
With whom do consumers interact?
Authors: Duong Hue Trong , Nguyen Long Thang Van , Vu Hong Tien
Published: October 2019

Purpose

The purpose of this study is to investigate the effects of congruent and incongruent anonymous comments posted to an online health news article on personal risk perception. This association is examined through testing the moderating roles of perceived similarity and approval ratings, and the mediating roles of source credibility and content credibility.

Design/methodology/approach

Hypotheses regarding the impact of comments on personal risk perception were tested experimentally using a news article, comments and approval ratings about the ear picking behavior. Data were collected from 391 young Vietnamese respondents.

Findings

The influence of online comments (congruent vs incongruent) on personal risk perception was mediated by source credibility and content credibility. Further, data showed a direct effect of online comments on personal risk perception. Interestingly, the direct and indirect effects of online comments on personal risk perception were observed among participants who perceived that anonymous commenters were similar to them. Approval ratings had neither a main nor interaction effect with comments on the dependent variables.

Practical implications

The results indicate that marketers should consider online comments as a powerful form of social influence, which may alter consumers’ personal risk perception.

Originality/value

The present study adds to social marketing literature by showing how consumers’ online comments influence personal risk perception in the context of changing media ecosystem.
Reacting to negative online customer reviews
Authors: Piehler Rico , Schade Michael , Hanisch Ines , Burmann Christoph
Published: October 2019

Purpose

The purpose of this paper is to investigate the effects of explanation and compensation, as specific accommodative management responses to negative online customer reviews, on potential customers.

Design/methodology/approach

The scenario-based online experiment with 306 participants investigates the effects of explanation and compensation on potential customers’ purchase intentions in the hotel segment of the hospitality industry.

Findings

The results reveal that combining an explanation with compensation is the most effective management response; providing neither an explanation nor compensation is the least effective. The effects of management responses that entail providing only an explanation or compensation do not differ significantly.

Research limitations/implications

Continued research should investigate the effects of specific accommodative management responses in other service industries and other cultural settings and consider different kinds of explanations and compensation.

Practical implications

Hotel managers in the hospitality industry should reply to negative online customer reviews by combining an explanation with compensation. Service providers that currently lack structures and procedures to identify service failures and their causes or that cannot take corrective actions should provide compensation. Service providers that currently have limited financial resources should provide explanations.

Originality/value

This study analyses the effects of explanation and compensation on potential customers’ purchase intentions. In addressing the effects on potential customers, instead of on complainants, the conceptual framework represents a novel combination of management responses from service recovery research with signalling theory, the search-experience-credence framework and risk reduction methods.
It looks nice, but does it work? Using student learning outcomes to assess library instructional spaces
Authors: Jarocki Zoe
Published: October 2019

Purpose

The purpose of this paper is to discuss how a mixed-methods approach to assessing student learning was used to determine the efficacy of redesigned library instructional spaces.

Design/methodology/approach

In 2017, the library at San Diego State remodeled a classroom to support active learning. The author undertook a pilot study to compare outcomes from the active learning classroom (ALC) and the traditional computer lab (CL) classroom. The assessment was done after one-shot library sessions for four sections of the same course in the ALC and the CL. Students completed surveys to assess their reactions to the instruction and e-mailed the librarian copies of the articles that they selected which were analyzed for quality using a rubric.

Findings

The mean scores from the CL classroom sections were slightly higher for the survey questions, though it was not statistically significant. The articles selected by students in the ALC had a slightly higher average quality score on the rubric, however, it was not large enough to be statistically significant.

Research limitations/implications

This was a limited assessment project and the results may not be generalizable to other institutions or types of instruction. Overall, students selected high-quality resources and felt positive about the library after instruction in both library classrooms. The data did not demonstrate significant improvements in student learning outcomes or attitudes in the remodeled ALC.

Originality/value

This mixed-methods assessment technique can be used to evaluate student learning and attitudes about the library and may be adapted by other librarians. It may also be of interest to those interested in designing learning spaces in libraries.
Conditions for kin selection to bring cooperation and improve population growth: A response to Iritani
Authors: Kobayashi Kazuya
Published: October 2019

To clarify how intraspecific competition over fertilization affects population growth rates and community dynamics in plants, Kobayashi (Journal of Ecology, 2019) proposed analytical and simulation models based on the game theory. Within this framework, it is suggested that the negative density‐dependent effect arising from sexual selection is an important force for sustaining biodiversity. Relaxing certain assumptions made in the analytical model, Iritani (Journal of Ecology, 2019) successfully incorporated the effect of kin selection in the model. This change makes a significant contribution towards improving the generality of the model.

Here, I clarify the contribution of Iritani (Journal of Ecology, 2019) and explain the condition under which kin selection promotes the evolution of cooperation (facilitativeness).

Kin selection has the potential to promote the evolution of cooperation under certain conditions. However, it is difficult to maintain cooperative traits in high‐density environments where individuals must interact with many other conspecifics. Thus, even after the model was extended by Iritani, it cannot be used to state that the negative density‐dependent effect arising from intraspecific competition over fertilization does not exist, but it has successfully revealed that the situation is more complex in nature.

Synthesis. Kin selection exists wherever intraspecific interactions between individuals occur, but does not necessarily lead to the evolution of cooperation. More detailed theoretical and empirical studies are needed to determine whether sexual selection generally produces negative density dependence, even when kin selection is taken into account.
High Opportunity Cost Demand as an Indicator of Weekday Drinking and Distinctly Severe Alcohol Problems: A Behavioral Economic Analysis
Authors: Joyner Keanan J. , Meshesha Lidia Z. , Dennhardt Ashley A. , Borsari Brian , Martens Matthew P. , Murphy James G.
Published: October 2019

Introduction

Behavioral economic theory views addiction as a reinforcer pathology characterized by excessive demand for drugs relative to alternatives. Complementary to this theory, Lamb and Ginsburg (Pharmacology Biochemistry and Behavior, 164, 2018, 62) describe addiction as a behavioral allocation disorder and predict that decisions to drink under increasingly stringent constraints are a central indicator of addiction. This study used a modified demand‐curve paradigm to examine alcohol demand in the context of a next‐day contingency (high opportunity cost demand) as a specific indicator of a severe pattern of alcohol problems.

Methods

Participants were 370 undergraduates (61.1% female, 86.5% white, Mage = 18.8) reporting multiple past‐month heavy drinking episodes (5/4 drinks per occasion for men/women) who completed 2 versions of an alcohol purchase task (APT), along with measures of past‐month alcohol use and problems. In 1 APT (low opportunity cost), students imagined they had no next‐day responsibilities, and in the other APT (high opportunity cost), they imagined having a 10:00 am test the next day. Item‐response theory analyses were used to determine mild and severe alcohol problems from the Young Adult Alcohol Consequences Questionnaire (Journal of Studies on Alcohol, 67, 2006, 169), and the most and least severe binge drinking days throughout the week.

Results

Low opportunity cost demand (β = 0.15, p = 0.02) significantly predicted beyond high opportunity cost demand for the least severe problems, and high opportunity cost demand (β = 0.17, p = 0.009) significantly predicted beyond low opportunity cost demand for the most severe problems. Similarly, low opportunity cost demand (β = 0.26, p < 0.001) was more highly associated with weekend drinking, whereas high opportunity cost demand (β = 0.21, p = 0.001) was more highly associated with weekday drinking.

Conclusions

The current results suggest high opportunity cost alcohol demand is a distinct marker of severe alcohol problems among college student heavy drinkers.
Efficacy and safety of tofacitinib dose de‐escalation and dose escalation for patients with ulcerative colitis: results from OCTAVE Open
Authors: Sands Bruce E. , Armuzzi Alessandro , Marshall John K. , Lindsay James O. , Sandborn William J. , Danese Silvio , Panés Julián , Bressler Brian , Colombel Jean‐Frédéric , Lawendy Nervin , Maller Eric , Zhang Haiying , Chan Gary , Salese Leonardo , Tsilkos Konstantinos , Marren Amy , Su Chinyu
Published: October 2019

Background

For patients with UC, flexible maintenance dosing therapy may confer advantages for safety, efficacy, costs and patient preference. Tofacitinib is an oral, small molecule JAK inhibitor for the treatment of UC.

Aim

To assess the efficacy and safety of tofacitinib dose de‐escalation and escalation in patients with UC.

Methods

We evaluated data (November 2017 data cut‐off) from OCTAVE Open, an ongoing, open‐label, long‐term extension study. The dose de‐escalation group comprised 66 tofacitinib induction responders in remission following 52 weeks' tofacitinib 10 mg b.d. maintenance therapy, subsequently de‐escalated to 5 mg b.d. in OCTAVE Open. The dose escalation group comprised 57 tofacitinib induction responders who experienced treatment failure while receiving 5 mg b.d. maintenance therapy, subsequently escalated to 10 mg b.d. in OCTAVE Open.

Results

After tofacitinib de‐escalation, 92.4% (61/66) and 84.1% (53/63) of patients maintained clinical response and 80.3% (53/66) and 74.6% (47/63) maintained remission, at months 2 and 12, respectively. After dose escalation, 57.9% (33/57) and 64.9% (37/57) of patients recaptured clinical response and 35.1% (20/57) and 49.1% (28/57) were in remission, at months 2 and 12, respectively. The incidence rate of herpes zoster with dose escalation (7.6 patients with events/100 patient‐years) was numerically higher than in the overall tofacitinib UC programme.

Conclusions

Following tofacitinib de‐escalation in patients already in remission on 10 mg b.d., most maintained remission, although 25.4% lost remission, at month 12. For induction responders who dose‐escalated following treatment failure on 5 mg b.d. maintenance therapy, 49.1% achieved remission by month 12. (ClinicalTrials.gov number: NCT01470612).
Survey of cases of tick‐paralysis and the presence of the eastern paralysis tick, Ixodes holocyclus, and the southern paralysis tick, Ixodes cornuatus, in the Greater Melbourne Area
Authors: Barker D , Barker SC
Published: October 2019

Objective

The objective of this study was to test the hypothesis that the paralysis ticks, Ixodes holocyclus and Ixodes cornuatus, are epizootic and/or enzootic in the Greater Melbourne Area (GMA).

Methods

We examined the ticks in the museum collections of Australia, wrote to, phoned and visited veterinarians and other colleagues in the GMA to gather information about the cases of tick paralysis and to request the ticks for identification.

Results

We present evidence of I. holocyclus at 24 postcodes and I. cornuatus at 28 postcodes in the GMA.

Conclusions

We found evidence that I. holocyclus is epizootic at four postcodes in the GMA: at East Melbourne, Williamstown, Moonee Ponds and Hoppers Crossing. We did not find evidence that I. holocyclus is enzootic in the GMA. I. cornuatus is apparently enzootic in the GMA at Bullengarook, Kinglake, Chum Creek and Healesville. Our hypothesis is that I. cornuatus is also enzootic at Mt Macedon, Gisborne and at other bushy postcodes in the GMA. Since this tick is apparently enzootic in the GMA, it may also be epizootic at postcodes adjacent to busy postcodes such as Bullengarook, Kinglake, Chum Creek and Healesville. The concept of hitch‐hiker larvae, nymphs and adult female ticks may explain many of the cases of tick paralysis due to I. holocyclus in the GMA. The accurate assessment of the risk of tick paralysis in dogs and cats in the GMA requires a more detailed map of the distribution of I. holocyclus and I. cornuatus in Victoria.
Secretory IgA accumulated in the airspaces of idiopathic pulmonary fibrosis and promoted VEGF, TGF-β and IL-8 production by A549 cells
Authors: Kobayashi K , Suzukawa M , Watanabe K , Arakawa S , Igarashi S , Asari I , Hebisawa A , Matsui H , Nagai H , Nagase T , Ohta K
Published: October 2019

Secretory IgA (SIgA) is a well-known mucosal-surface molecule in first-line defense against extrinsic pathogens and antigens. Its immunomodulatory and pathological roles have also been emphasized, but it is unclear whether it plays a pathological role in lung diseases. In the present study, we aimed to determine the distribution of IgA in idiopathic pulmonary fibrosis (IPF) lungs and whether IgA affects the functions of airway epithelial cells. We performed immunohistochemical analysis of lung sections from patients with IPF and found that mucus accumulated in the airspaces adjacent to the hyperplastic epithelia contained abundant SIgA. This was not true in the lungs of non-IPF subjects. An in-vitro assay revealed that SIgA bound to the surface of A549 cells and significantly promoted production of vascular endothelial growth factor (VEGF), transforming growth factor (TGF)-β and interleukin (IL)-8, important cytokines in the pathogenesis of IPF. Among the known receptors for IgA, A549 cells expressed high levels of transferrin receptor (TfR)/CD71. Transfection experiments with siRNA targeted against TfR/CD71 followed by stimulation with SIgA suggested that TfR/CD71 may be at least partially involved in the SIgA-induced cytokine production by A549 cells. These phenomena were specific for SIgA, distinct from IgG. SIgA may modulate the progression of IPF by enhancing synthesis of VEGF, TGF-β and IL-8.
Lymph node ratio as a prognostic marker in advanced laryngeal and hypopharyngeal carcinoma after primary total laryngopharyngectomy
Authors: Grasl Stefan , Janik Stefan , Parzefall Thomas , Formanek Michael , Grasl Matthaeus C. , Heiduschka Gregor , Erovic Boban M.
Published: October 2019

Background

We evaluated the prognostic value of lymph node ratio (LNR) in patients with advanced laryngeal and hypopharyngeal squamous cell carcinoma.

Study Design

Retrospective chart review.

Methods

Between 1994 and 2018, 79 patients underwent total laryngopharyngectomy and adjuvant therapy. LNR was determined and statistically compared to patients’ overall survival (OS), disease‐specific survival (DSS), disease‐free survival (DFS), locoregional and distant failure.

Results

The 5‐year OS, DSS and DFS rates were 45.6%, 73.4% and 56.9%, respectively. 24.1% and 25.3% developed loco‐ regional failure or distant metastatic disease, respectively. Univariate analyses showed that high LNR (cut‐off >0.07) was significantly associated with distant and locoregional failure. On multivariate analysis, LNR remained an independent predictor for OS (P = .004), DSS (P = .009) and DFS (P = .044).

Conclusion

Increased LNR in patients with advanced laryngeal or hypopharyngeal carcinoma is significantly linked to shortened OS, DSS, DFS and higher locoregional and distant metastatic disease.
The influence of vestibular stimulation on metabolism and body composition
Authors: McKeown J. , McGeoch P. D. , Grieve D. J.
Published: October 2019

Obesity, diabetes and metabolic disease represent an ongoing and rapidly worsening public health issue in both the developed, and much of the developing world. Although there are many factors that influence fat storage, it has been clearly demonstrated that the homeostatic cornerstone of metabolism lies within the hypothalamus. Moreover, neuronal damage to vital areas of the hypothalamus can drive reregulation or dysregulation of endocrine function, energy expenditure and appetite, thereby promoting a shift in overall metabolic function towards a state of obesity. Therefore, identification of treatments that influence the hypothalamus to improve obesity and associated metabolic diseases has long been a medical goal. Interestingly, evidence from animal studies suggests that activating the vestibular system, specifically the macular gravity receptor, influences the hypothalamus in a way that decreases body fat storage and causes a metabolic shift towards a leaner state. Given that the macular element of the vestibular system has been shown to activate with transdermal electrical stimulation applied to the mastoids, this may be a potential therapeutic approach for obesity, diabetes or related metabolic diseases, whereby repetitive stimulation of the vestibular system influences hypothalamic control of metabolic homeostasis, thereby encouraging decreased fat storage. Here, we present an up‐to‐date review of the current literature surrounding the vestibular influence of the hypothalamus and associated homeostatic sites in the context of current and novel therapeutic approaches for improved clinical management of obesity and diabetes.
Explosions of Stupidity: Notes for an Urbanist Pedagogy
Authors: Ford Derek R.
Published: October 2019

In this article, Derek R. Ford develops an urbanist pedagogy, a particular mode of educational praxis that arises out of — and, more importantly, is oriented toward — the creation of the urban, a praxis that is internal to and constitutive of urban revolt. Ford does so with the help of two thinkers who are seldom theorized together: Henri Lefebvre and Jean‐François Lyotard. Taken together, Lefebvre and Lyotard allow him to advance a conception of the urban not as an object, thing, or distinct space (like the city), but as an incommunicable process that entails two distinct and interrelated creative educational elements: explosive confrontation and stupor. At the end of the article, Ford reads this urbanist pedagogy through a set of protest movements in West Germany.
The Art of Straying: Benjamin on Distraction and the Informal Education of the City
Authors: Lewis Tyson E.
Published: October 2019

In this article, Tyson E. Lewis argues for an alternative form of educational attunement beyond attentiveness. Discourses and practices of schooling emphasize being attentive as a primary educational virtue. This emphasis casts distraction as either the negation of attention or its deterioration. In either case, distraction lacks educational use and, as such, must be overcome through the cultivation of attention. Yet this approach to the question of attention versus distraction misses how distraction contains within itself a different kind of educational potentiality, a different kind of educational attunement. In an attempt to carve out space and time for distraction, Lewis turns to the writings of Walter Benjamin who offers up a more complex view of distraction than is presently found in educational philosophy. In particular, Benjamin argues that cities are not only places of negative forms of distraction (as mere diversions), but also places for cultivating productive distraction in the form of an open and alert attunement to new ways of experiencing and perceiving the relationship between world and self. Cities, for Benjamin, become educational spaces that teach lessons in a distracted form of life, the culmination of which is the creativity expressed in what he refers to as “the art of straying.”