bluuebunny/crossref_metadata_2025 huggingface dataset:
Response Inhibition in Adolescents is Moderated by Brain Connectivity and Social Network Structure
Authors: Tompson Steven H , Falk Emily B , O’Donnell Matthew Brook , Cascio Christopher N , Bayer Joseph B , Vettel Jean M , Bassett Danielle S
Published: August 2020

The social environment an individual is embedded in influences their ability and motivation to engage self-control processes, but little is known about the neural mechanisms underlying this effect. Many individuals successfully regulate their behavior even when they do not show strong activation in canonical self-control brain regions. Thus, individuals may rely on other resources to compensate, including daily experiences navigating and managing complex social relationships that likely bolster self-control processes. Here, we employed a network neuroscience approach to investigate the role of social context and social brain systems in facilitating self-control in adolescents. We measured brain activation using fMRI as 62 adolescents completed a Go/No-Go response inhibition task. We found that self-referential brain systems compensate for weaker activation in executive function brain systems, especially for adolescents with more friends and more communities in their social networks. Collectively, our results indicate a critical role for self-referential brain systems during the developmental trajectory of self-control throughout adolescence.
Hierarchical Pathways from Sensory Processing to Cognitive, Clinical, and Functional Impairments in Schizophrenia
Authors: Koshiyama Daisuke , Thomas Michael L , Miyakoshi Makoto , Joshi Yash B , Molina Juan L , Tanaka-Koshiyama Kumiko , Sprock Joyce , Braff David L , Swerdlow Neal R , Light Gregory A
Published: August 2020

Cognitive impairment is a hallmark of schizophrenia and a robust predictor of functional outcomes. Impairments are found in all phases of the illness and are only moderately attenuated by currently approved therapeutics. Neurophysiological indices of sensory discrimination (ie, mismatch negativity (MMN) and P3a amplitudes) and gamma-band auditory steady-state response (ASSR; power and phase locking) are translational biomarkers widely used in the development of novel therapeutics for neuropsychiatric disorders. It is unclear whether laboratory-based EEG measures add explanatory power to well-established models that use only cognitive, clinical, and functional outcome measures. Moreover, it is unclear if measures of sensory discrimination and gamma-band ASSR uniquely contribute to putative causal pathways linking sensory discrimination, neurocognition, negative symptoms, and functional outcomes in schizophrenia. To answer these questions, hierarchical associations among sensory processing, neurocognition, clinical symptoms, and functional outcomes were assessed via structural equation modeling in a large sample of schizophrenia patients (n = 695) and healthy comparison subjects (n = 503). The results showed that the neurophysiologic indices of sensory discrimination and gamma-band ASSR both significantly contribute to and yield unique hierarchical, “bottom-up” effects on neurocognition, symptoms, and functioning. Measures of sensory discrimination showed direct effects on neurocognition and negative symptoms, while gamma-band ASSR had a direct effect on neurocognition in patients. Continued investigation of the neural mechanisms underlying abnormal networks of MMN/P3a and gamma-band ASSR is needed to clarify the pathophysiology of schizophrenia and the development of novel therapeutic interventions.
A Randomized Clinical Trial of Oxytocin or Galantamine in Schizophrenia: Assessing the Impact on Behavioral, Lexical, and Self-Report Indicators of Social Affiliation
Authors: Dwyer Kristen R , Andrea Alexandra M , Savage Christina L G , Orth Ryan D , Shan LeeAnn , Strauss Gregory P , Adams Heather A , Kelly Deanna L , Weiner Elaine , Gold James M , McMahon Robert P , Carpenter William T , Buchanan Robert W , Blanchard Jack J
Published: August 2020

Prior studies examining the impact of oxytocin on negative symptoms in schizophrenia have yielded mixed results. The current study explored whether oxytocin can improve more proximal indicators of social affiliation as indicated by changes in behavior, language and subjective indices of social affiliation among individuals with schizophrenia spectrum disorders during a role-play designed to elicit affiliative responses. We tested the hypothesis that daily intranasal oxytocin administered for 6 weeks would improve social affiliation as manifested by increased social skill ratings, use of positive, affiliative, and social words, and subjective responses from a previously published randomized controlled trial. Forty outpatients with schizophrenia or schizoaffective disorder were randomized to the oxytocin, galantamine, or placebo group and completed affiliative role-plays and self-report questionnaires of affect, reactions to the affiliative confederate, and willingness to interact at baseline and post-treatment. Results demonstrated that oxytocin was not effective at improving behavioral or subjective indicators of social affiliation. This study adds to a growing literature that the prosocial effects of oxytocin in schizophrenia are limited or null.
Genome-wide analysis of DNA methylation in testis of male rat exposed to chlorpyrifos
Authors: Sai Linlin , Jia Qiang , Zhang Yecui , Han Ru , Geng Xiao , Yu Gongchang , Li Shumin , Shao Hua , Zheng Yuxin , Peng Cheng
Published: August 2020

In our previous study, we found that subchronic exposure of chlorpyrifos (CPF) can cause reproductive damage in male rats. However, the mechanisms underlying the reproductive effects of CPF are not well understood. DNA methylation is essential for epigenetic gene regulation in development and disease. Therefore, we aim to compare DNA methylation profiles between controls and CPF-treated rats in order to identify the epigenetic mechanism of male reproductive toxicity induced by CPF. Methylated DNA immunoprecipitation with high-throughput sequencing (MeDIP-seq) was used to investigate the genome-wide DNA methylation pattern in testes of control and CPF-treated rats for 90 days. We identified 27 019 differentially methylated regions (DMRs) (14 150 upmethylated and 12 869 downmethylated) between CPF-exposed and control groups. The DMR-related genes are mainly involved in 113 pathways predicted by Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. The result showed that high methylation gene PIK3CD may play a key role in epigenetic regulation of multiple pathways, such as Ras signaling pathway, AGE–RAGE signaling pathway in diabetic complications, HIF-1 signaling pathway, VEGF signaling pathway, and glioma and Fc epsilon RI signaling pathway in rats exposed to CPF. Our study provides significant explanations for the epigenetic mechanism of male reproductive toxicology induced by CPF.
Efficiency, Legitimacy, and Impacts of Targeting Methods: Evidence from an Experiment in Niger
Authors: Premand Patrick , Schnitzer Pascale
Published: August 2020

The methods to select safety net beneficiaries are the subject of frequent debates. Targeting assessments usually focus on efficiency by documenting the pre-program profile of selected beneficiaries. This study provides a more comprehensive analysis of targeting performance through an experiment embedded in a national cash transfer program in Niger. Eligible villages were randomly assigned to have beneficiary households selected by community-based targeting (CBT), proxy-means testing (PMT), or a formula to identify the food-insecure (FCS). The study considers targeting legitimacy and the impact of targeting choice on program effectiveness based on data collected after program roll-out. PMT is more efficient in identifying households with lower consumption per capita. Nonbeneficiaries find formula-based methods (PMT and FCS) more legitimate than CBT. Manipulation and information imperfections affect CBT, which can explain why it is not the most legitimate. Program impacts on some welfare dimensions are larger among households selected by PMT than CBT.
Discontinuation of Immunosuppressive Medications in Children With Inflammatory Bowel Disease on Combination Therapy
Authors: El‐Matary Wael , Carroll Matthew W. , Debruyn Jennifer C. , Huynh Hien , Wine Eytan , Lawrence Sally , Chandrakumar Abin , Morel Terra , Jacobson Kevan
Published: August 2020

We determined the frequency and factors associated with the first clinical relapse after immunomodulator (IM) withdrawal in a cohort of children with inflammatory bowel disease on combination therapy. A total of 105 patients (89 with Crohn disease [CD]) in clinical remission were included (91 [86.7%] were on infliximab, 53 [50.5%] with methotrexate, and 52 on azathioprine). The median duration of combination therapy was 2.1 years (interquartile range [IQR] 1.3–2.8). Only 11 (10.5%) patients experienced a clinical relapse over a median duration of follow‐up of 12.0 months (IQR 5.0–19.0) after IM discontinuation. The median baseline pediatric CD activity index in those with CD who relapsed after IM discontinuation was 47.5 (IQR: 35.0–55.0) versus those who did not relapse (median 35.0, IQR: 20.0–52.5; P = 0.04). In the patients who did not relapse, the median IFX trough level at IM discontinuation was 6.2 and 3.8 μg/mL in those who relapsed.
The Liver in Sickle Cell Disease
Authors: Lacaille Florence , Allali Slimane , de Montalembert Mariane
Published: August 2020

Liver involvement is found in nearly 40% of children with sickle cell disease. The most frequent complication is cholelithiasis. The most severe complication is acute hepatic crisis, with symptoms ranging from increasing jaundice to multiple organ failure and death. The emergency and mostly efficient treatment is exchange transfusion. Chronic cholangiopathy is increasingly recognized, with autoimmune features in most cases, worsened by chronic ischemia. Transfusion‐related iron overload is not yet a concern in children, and hepatotoxicity of iron chelators is rare. We propose recommendations to prevent, explore, and treat these complications. We emphasize the close collaboration required between hepatologists and specialists of sickle cell disease.
Validation of International Classification of Diseases, Tenth Revision, Clinical Modification Codes for Identifying Cases of Chlamydia and Gonorrhea
Authors: Ho Yenling Andrew , Rahurkar Saurabh , Tao Guoyu , Patel Chirag G. , Arno Janet N. , Wang Jane , Broyles Andrea A. , Dixon Brian E.
Published: August 2020

Background

While researchers seek to use administrative health data to examine outcomes for individuals with sexually transmitted infections (STIs), the International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) codes used to identify persons with chlamydia and gonorrhea have not been validated. Objectives were to determine the validity of using ICD-10-CM codes to identify individuals with chlamydia and gonorrhea.

Methods

We used data from electronic health records gathered from public and private health systems from October 1, 2015, to December 31, 2016. Patients were included if they were aged 13 to 44 years and received either (1) laboratory testing for chlamydia or gonorrhea or (2) an ICD-10-CM diagnosis of chlamydia, gonorrhea, or an unspecified STI. To validate ICD-10-CM codes, we calculated positive and negative predictive values, sensitivity, and specificity based on the presence of a laboratory test result. We further examined the timing of clinical diagnosis relative to laboratory testing.

Results

The positive predictive values for chlamydia, gonorrhea, and unspecified STI ICD-10-CM codes were 87.6%, 85.0%, and 32.0%, respectively. Negative predictive values were high (>92%). Sensitivity for chlamydia diagnostic codes was 10.6%, and gonorrhea was 9.7%. Specificity was 99.9% for both chlamydia and gonorrhea. The date of diagnosis occurred on or after the date of the laboratory result for 84.8% of persons with chlamydia, 91.9% for gonorrhea, and 23.5% for unspecified STI.

Conclusions

Disease-specific ICD-10-CM codes accurately identify persons with chlamydia and gonorrhea. However, low sensitivities suggest that most individuals could not be identified in administrative data alone without laboratory test results.
Assessment of Cerebral Collateral Flow With Single-Phase Computed Tomography Angiography–Based Multimodal Scales in Patients With Acute Ischemic Stroke
Authors: He Haoran , Qian Zhong-Ming , Sheng Yuan , Liu Yong
Published: August 2020

Objective

Assessing collateral status is important in acute ischemic stroke (AIS). The purpose of this study was to establish an easy and rapid method for evaluating collateral flow.

Methods

A total of 60 patients with AIS were enrolled. The patients were aged 18 to 85 years with endovascular therapy treatment within 10 hours after the appearance of stroke symptoms, prestroke modified Rankin Scale ≤1, Alberta Stroke Program Early CT Score ≥6, and the occlusion of large vessels in anterior circulation. We reformed imaging strategies by conducting a small-dose group-injection test before normal computed tomography angiography (CTA) scanning and selected the visual collateral score and the regional leptomeningeal score scales as the single-phase CTA collateral flow assessment scales with the replacement of the parasagittal anterior cerebral artery territory by anterior cerebral artery regions adjacent to the longitudinal fissure and then verified, respectively, the consistencies between the 2 single-phase CTA-based collateral scales and the digital subtraction angiography (DSA)–based American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology scale and compared the prognosis of endovascular therapy between the AIS patients in the poor-collateral-flow group and the other patients' group assessed by 2 single-phase CTA-based collateral scales.

Results

There was a high consistency between the 2 single-phase CTA-based collateral flow scales with DSA-based American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology scale. The assessment by using CTA-based collateral flow assessment methods generated consistent results.

Conclusion

The single-phase CTA-based visual collateral score scale and regional leptomeningeal score scale can be used as the imaging evidence for the evaluation of collateral flow in AIS patients in the majority of grassroots hospitals where DSA is difficult to carry out.
Photo-bioconvection: towards light control of flows in active suspensions
Authors: Javadi A. , Arrieta J. , Tuval I. , Polin M.
Published: August 2020

The persistent motility of individual constituents in microbial suspensions represents a prime example of the so-called active matter systems. Cells consume energy, exert forces and move, overall releasing the constraints of equilibrium statistical mechanics of passive elements and allowing for complex spatio-temporal patterns to emerge. Moreover, when subject to physico-chemical stimuli their collective behaviour often drives large-scale instabilities of a hydrodynamic nature, with implications for biomixing in natural environments and incipient industrial applications. In turn, our ability to exert external control of these driving stimuli could be used to govern the emerging patterns. Light, being easily manipulable and, at the same time, an important stimulus for a wide variety of microorganisms, is particularly well suited to this end. In this paper, we will discuss the current state, developments and some of the emerging advances in the fundamentals and applications of light-induced bioconvection with a focus on recent experimental realizations and modelling efforts.

This article is part of the theme issue ‘Stokes at 200 (part 2)’.
Stokes' law, viscometry, and the Stokes falling sphere clock
Authors: Cartwright Julyan H. E.
Published: August 2020

Clocks run through the history of physics. Galileo conceived of using the pendulum as a timing device on watching a hanging lamp swing in Pisa cathedral; Huygens invented the pendulum clock; and Einstein thought about clock synchronization in his Gedankenexperiment that led to relativity. Stokes derived his law in the course of investigations to determine the effect of a fluid medium on the swing of a pendulum. I sketch the work that has come out of this, Stokes drag, one of his most famous results. And to celebrate the 200th anniversary of George Gabriel Stokes’ birth I propose using the time of fall of a sphere through a fluid for a sculptural clock—a public kinetic artwork that will tell the time.

This article is part of the theme issue ‘Stokes at 200 (part 2)’.
A systematic review of the genera Geobacillus and Parageobacillus: their evolution, current taxonomic status and major applications
Authors: Najar Ishfaq Nabi , Thakur Nagendra
Published: August 2020

The genus

Geobacillus

, belonging to the phylum Firmicutes, is one of the most important genera and comprises thermophilic bacteria. The genus

Geobacillus

was erected with the taxonomic reclassification of various

Bacillus

species. Taxonomic studies of

Geobacillus

remain in progress. However, there is no comprehensive review of the characteristic features, taxonomic status and study of various applications of this interesting genus. The main aim of this review is to give a comprehensive account of the genus

Geobacillus

. At present the genus acomprises 25 taxa, 14 validly published (with correct name), nine validly published (with synonyms) and two not validly published species. We describe only validly published species of the genera

Geobacillus

and

Parageobacillus

. Vegetative cells of

Geobacillus

species are Gram-strain-positive or -variable, rod-shaped, motile, endospore-forming, aerobic or facultatively anaerobic, obligately thermophilic and chemo-organotrophic. Growth occurs in the pH range 6.08.5 and a temperature of 37–75 °C. The major cellular fatty acids are iso-C15:o, iso-C16:0 and iso-C17:o. The main menaquinone type is MK-7. The G­+C content of the DNA ranges between 48.2 and 58 mol%. The genus

Geobacillus

is widely distributed in nature, being mostly found in many extreme locations such as hot springs, hydrothermal vents, marine trenches, hay composts, etc.

Geobacillus

species have been widely exploited in various industrial and biotechnological applications, and thus are promising candidates for further studies in the future.
Improving the flexibility of Genetically Encoded Voltage Indicators via intermolecular FRET
Authors: Leong Lee Min , Kang Bok Eum , Baker Bradley
Published: August 2020

A new family of Genetically Encoded Voltage Indicators (GEVIs) has been developed based on inter-molecular Förster Resonance Energy Transfer (FRET). To test the hypothesis that the GEVI, ArcLight, functions via interactions between the fluorescent protein (FP) domain of neighboring probes, the FP of ArcLight was replaced with either a FRET donor or acceptor FP. We discovered relatively large FRET signals only when cells were co-transfected with both the FRET donor and acceptor GEVIs. Using a CFP donor and an RFP acceptor, we were able to observe a voltage dependent signal with a Stokes shift of over 200 nm. The intermolecular FRET strategy also works for rhodopsin-based probes potentially improving their flexibility as well. Separating the FRET pair into two distinct proteins has important advantages over intramolecular FRET constructs. First, the signals are larger. Apparently the voltage-induced conformational change moves the two FPs independently thereby increasing the dynamic range. Second, the expression of the FRET donor and acceptor can be restricted independently enabling greater cell type specificity as well as refined subcellular voltage reporting.
How to map a plantain: phylogeny of the diversePlantagineae(Lamiales)
Authors: Shipunov Alexey , Fernández A. José Luis , Hassemer Gustavo , Alp Sean , Lee Hye Ji , Pay Kyle
Published: August 2020

The tribePlantagineae(Lamiales) is a group of plants with worldwide distribution, notorious for its complicated taxonomy, still unresolved natural history, and a trend of morphologic reduction and simplification. This tribe includes the plantains (Plantago), the small aquaticLittorella, and the northern Andean shrubsAragoa. SomePlantagolineages exhibit remarkably high diversification rates, which further adds to the complicated classification, and the worldwide distribution of these plants raises numerous questions related to vicariance and dispersal. In this work, we present the broadest phylogeny of the group to date and discuss the evolutionary, morphological, and biogeographical implications of our phylogenetic results, including the description of two new species from the Americas.
A Unified Framework for Lineage Tracing and Trajectory Inference
Authors: Forrow Aden , Schiebinger Geoffrey
Published: August 2020

Understanding the genetic and epigenetic programs that control differentiation during development is a fundamental challenge, with broad impacts across biology and medicine. New measurement technologies like single-cell RNA-sequencing and CRISPR-based lineage tracing have opened new windows on these processes, through computational trajectory inference and lineage reconstruction. While these two mathematical problems are deeply related, they been approached from separate directions: methods for trajectory inference are not typically designed to leverage information from lineage tracing and vice versa. We present a novel, unified framework for lineage tracing and trajectory inference. Specifically, we develop a method for reconstructing developmental trajectories from time courses with snapshots of both cell states and lineages, leveraging mathematical tools from graphical models and optimal transport. We find that lineage data helps disentangle complex state transitions with increased accuracy using fewer measured time points. Moreover, integrating lineage tracing with trajectory inference in this way enables accurate reconstruction of developmental pathways that are impossible to recover with state-based methods alone.
Dense poly(ethylene glycol) coatings maximize nanoparticle transport across lymphatic endothelial cells and accumulate in the skindraining lymph nodes
Authors: McCright Jacob , Skeen Colin , Yarmovsky Jenny , Maisel Katharina
Published: August 2020

Lymphatic vessels have recently been shown to effectively deliver immune modulatory therapies to the lymph nodes, which enhances their therapeutic efficacy. Prior work has shown that lymphatics transport 10–250 nm nanoparticles from peripheral tissues to the lymph node. However, the surface chemistry required to maximize this transport is poorly understood. Here, we determined the effect of surface poly(ethylene glycol) (PEG) density and size on nanoparticle transport across lymphatic endothelial cells (LECs) by differentially PEGylated model polystyrene nanoparticles. Using an establishedin-vitrolymphatic transport model, we found PEGylation improved the transport of 100 and 40 nm nanoparticles across LECs 50-fold compared to the unmodified nanoparticles and that transport is maximized when the PEG is in a dense brush conformation or high grafting density (Rf/D = 4.9). We also determined that these trends are not size-dependent. PEGylating 40 nm nanoparticles improved transport efficiency across LECs 68-fold compared to unmodified nanoparticles. We also found that PEGylated 100 nm and 40 nm nanoparticles accumulate in lymph nodes within 4 hours after intradermal injection, while unmodified nanoparticles accumulated minimally. Dense PEGylation also led nanoparticles to travel the furthest distance from the injection site. Finally, we determined that nanoparticles are transported via both paracellular and transcellular mechanisms, and that PEG conformation modulates the cellular transport mechanisms. Our results suggest that PEG conformation is crucial to maximize nanoparticle transport across LECs and into lymphatic vessels, making PEG density a crucial design. Optimizing PEG density on nanoparticle formulations has the potential to enhance immunotherapeutic and vaccine outcomes.
Sleep loss disrupts hippocampal memory consolidation via an acetylcholine- and somatostatin interneuron-mediated inhibitory gate
Authors: Delorme James , Kuhn Femke Roig , Wang Lijing , Kodoth Varna , Ma Jingqun , Jiang Sha , Aton Sara J.
Published: August 2020

Sleep loss profoundly disrupts consolidation of hippocampus-dependent memory. To better characterize effects of learning and sleep loss on the hippocampal circuit, we quantified activity-dependent phosphorylation of ribosomal subunit S6 (pS6) across the dorsal hippocampus of mice. We find that pS6 in enhanced in the dentate gyrus (DG) following single-trial contextual fear conditioning (CFC), but is reduced throughout the hippocampus after brief sleep deprivation (SD) – a manipulation which disrupts contextual fear memory (CFM) consolidation. To characterize cell populations with activity affected by SD, we used translating ribosome affinity purification (TRAP)-seq to identify cell type-specific transcripts on pS6 ribosomes after SD vs. sleep. Cell type-specific enrichment analysis (CSEA) of these transcripts revealed that hippocampal somatostatin-expressing (Sst+) interneurons, and cholinergic and orexinergic inputs to hippocampus, are selectively activated after SD. We used TRAP targeted to hippocampal Sst+ interneurons to identify cellular mechanisms mediating SD-driven Sst+ interneuron activation. We next used pharmacogenetics to mimic the effects of SD, selectively activating hippocampal Sst+ interneurons while mice slept in the hours following CFC. We find that activation of Sst+ interneurons is sufficient to disrupt CFM consolidation, by gating activity in surrounding pyramidal neurons. Pharmacogenetic inhibition of cholinergic input to hippocampus from the medial septum (MS) promoted CFM consolidation and disinhibited neurons in the DG, increasing pS6 expression. This suggests that state-dependent gating of DG activity is mediated by cholinergic input during SD. Together these data provide evidence for an inhibitory gate on hippocampal information processing, which is activated by sleep loss.
Timing of neurogenesis through sequential accumulation of miR-9 due to additive expression of multiple alleles
Authors: Soto X. , Burton J. , Manning C. , Minchington T. , Lea R. , Lee J. , Kursawe J. , Rattray M. , Papalopulu N.
Published: August 2020

MicroRNAs (miRs) have important quantitative roles in tuning dynamical gene expression. Hes/Her transcription factor dynamics are sensitive to the increasing amount of miR-9 in the cell, transitioning from noisy high-level expression to oscillatory expression and then to downregulation. However, the mechanism by which miR-9 is quantitatively controlled is not known. In vertebrates, several distinct genomic loci produce the same mature miR-9, but the functional significance of multiple primary transcripts remains unknown. Here, we show that the amount of mature miR-9 increases during zebrafish neurogenesis in a sharp stepwise manner. We characterize the spatiotemporal profile of 7 distinct pri-mir-9s and show that they are sequentially expressed during hindbrain neurogenesis. Quantitative analysis of expression at the single-cell level, shows that expression of late-onset pri-mir-9-1 is added on, rather than replacing the expression of early onset pri-mir-9-4 and 9-5. Mutating the late-onset pri-mir-9-1 with CRISPR/Cas9 prevents the developmental increase of mature miR-9 and reduces late neuronal differentiation. Finally, we use mathematical modelling to explore possible benefits of a stepwise increase of miR-9 over a linear increase. We find that an adaptive network containing Her6 can be insensitive to a linear increase in miR-9 and show that such adaptation can be overcome by step-wise increases of miR-9. In conclusion, our work suggests that a sharp stepwise increase of mature miR-9 is contributed by sequential temporal activation of distinct loci. This may be a strategy to overcome adaptation and facilitate a transition to a new state of Her6 dynamics or level.
Introducing Genes into Mammalian Cells: Viral Vectors
Authors: Sena-Esteves Miguel , Gao Guangping
Published: August 2020

Over the years, many different viral vector systems have been developed to take advantage of the specific biological properties and tropisms of a large number of mammalian viruses. As a result, researchers wanting to introduce and/or express genes in mammalian cells have many options, as discussed here.
Alkaline Phosphatase
Authors: Green Michael R. , Sambrook Joseph
Published: August 2020

Several types of alkaline phosphatases (or alkaline phosphomonoesterase) are commonly used in molecular cloning, including bacterial alkaline phosphatase (BAP) and calf intestinal alkaline phosphatase (CIP, CIAP, or CAP). Similar enzymes isolated from more esoteric cold-blooded organisms (e.g., SAP from shrimp) have become available in recent years and have the advantage of being easier to inactivate than BAP or CIP at the end of dephosphorylation reactions. The uses and properties of these enzymes are introduced here.
CSF-PC based grid tied improved hybrid three quasi Z source converter
Authors: Alla Ramanjaneyulu , Chowdhury Anandita
Published: August 2020

Purpose

A new control method is proposed for grid integration of improved hybrid three quasi z source converter (IHTQZSC). The proposed controller provides a constant switching frequency with an improved dynamic response with fewer computations. The proposed constant switching frequency predictive controller (CSF-PC) does not need weighting factors and reduces the complexity of the control circuit.

Design/methodology/approach

A single PI controller is intended to control voltage across dc-link by generating the necessary shoot-through duty ratio. The predictive controller produces the modulating signals required to inject the desired grid current. The performance of the proposed controller is validated with MATLAB/Simulink software.

Findings

The discrete-time instantaneous model on the grid side in the proposed controller influences the inductor current with minimum ripples. Dynamic response and computational complexity of the converter with the PI controller, finite set model predictive controller (FS-MPC) and the proposed controller are discussed.

Practical implications

The converter belongs to impedance source converters (ISC) family, delivers higher voltage gain in a single-stage power conversion process, extract the energy from the intermittent nature of renewable energy conversion systems. Implementing CSF-PC for ISC is simple, as it has a single PI controller.

Originality/value

Grid integration of high voltage gain IHTQZSC is accomplished with PI, FS-MPC and CSF-PC. Though the FS-MPC exhibits superior dynamic response under input voltage disturbance and grid current variation, total harmonic distortion (THD) in the grid current is high. CSF-PC provides better THD with a good dynamic response with reduced inductor current ripples.
A political–economic explanation of “internet space”
Authors: Ma Yan , Minqiang Cai , Yun Li
Published: August 2020

Purpose

The purpose of this paper is to define the Internet as a virtual space supported by technologies and presented in the form of socioeconomic relations from the perspective of political economy. The Internet space is a unique virtual commodity different from ordinary commodities and has the following effect characteristics: super replicability, space- and time-transcendence, open-source shareability and reality–virtuality transformation.

Design/methodology/approach

Internet space can also be imagined as a piece of virtual land. Internet space can be deemed as a piece of virtual land and its value can be divided into labor value and virtual value. The pricing model of virtual value is mainly determined by the gain and discount rate and this value comes from the transfer and markup of social value. In the context of the Internet Plus era, Internet space has become an essential economic factor that influences human economic activities.

Findings

Therefore, it is of practical significance and theoretical value to introduce Internet space as an economic variable into the framework of economic theory. The realistic logic of Internet space is to influence human economic behaviors with the combination of information binding.

Originality/value

The theoretical mechanism is to have an impact on the micro-market price by changing market relations from two-dimensional to three-dimensional. Its path to functioning at the macro level is to influence economic behaviors by changing the expectations of investment and consumption, resulting in new economic trends.
Managerial implications for construction practices as a consequence of using a psychological contract of safety
Authors: Newaz Mohammad Tanvi , Jefferies Marcus , Davis Peter Rex , Pillay Manikam
Published: August 2020

Purpose

Despite many studies that aim to argue, develop and position the concept of psychological contracts, few have explored how a psychological contract may be applied to safety in the construction industry. A psychological contract of safety (PCS) describes an individual's conceptualized belief that relates to mutual safety obligations, drawn from explicit or implicit promises of associated workers or its supervisor. This study investigates safety practices on construction sites through the lens of the widely applied and researched psychological contract theory emanating from a business paradigm.

Design/methodology/approach

The process of validating a PCS scale within the construction industry required the collection of data from a mega-construction project in Sydney, Australia. A quantitative methodology was used to collect data from 352 construction workers through a survey instrument designed to reveal their perception of procedures, policies and practices. Structural equation modelling (SEM) was used to ensure data reliability and data validity of the survey findings together with goodness of fit of PCS model.

Findings

The findings showed the presence of a PCS in a construction safety setting examined. A two-factor model underlying aspects, namely employer and employee obligations was recommended since the four-factor model, including relational and transactional components of both parties' safety obligations, could not be validated due to the discriminant validity associated with the particular constructs.

Originality/value

Conceptualizing the extant PC theory as a framework from which to leverage safety management initiatives brings a new approach to construction safety studies, revealing the influential role of supervisors in interpreting safety practices. The research aimed to identify safety obligations, which are influential in the development of PSC scale, further the research provides an explanation as to how a PCS may be contextualized in the construction industry.
An exploratory study of safety communication networks of ethnic minority crews in the Hong Kong construction industry
Authors: Lyu Sainan , Hon Carol K.H. , Chan Albert P.C. , Javed Arshad Ali , Zhang Rita Peihua , Wong Francis K.W.
Published: August 2020

Purpose

Previous studies have highlighted that communication barrier was one of the major safety problems faced by ethnic minority (EM) workers. This study aims to model the predominant safety communication networks of EM crews and explore the relationships among safety communication networks, individual attributes, safety climate, near misses and injuries of EM crews.

Design/methodology/approach

Case studies were conducted with EM crews in the Hong Kong construction industry. Demographic attribute, network, safety climate and accidents data were collected through questionnaires and analyzed by a combination of social network analysis (SNA), cross-case comparison and nonparametric tests.

Findings

The results revealed that language proficiency, network density and level of reciprocity were contributing factors of distinguishing high and low safety performing EM crews. EM management received more safety information from EM workers than local management. The centrality of EM workers was significantly related to their age, the perceived priority of safety and language ability.

Practical implications

The research findings regarding the impact of safety communication network characteristics on the safety performance of EM crews provides insights to employers on how to cultivate effective safety communication patterns within EM crews that can lead to better safety performance. The connections between personal attributes and their positions in safety communication networks could help the employers identify the EM workers who are positioned on edges of networks and need more attention.

Originality/value

This study contributes to knowledge by enriching the limited research on analyzing safety communication of small construction crews using SNA and expanding the research object to EM construction crews in the literature, who are more vulnerable to construction accidents. This research also extends the existing body of knowledge from studies mainly carried out in Western culture to Eastern culture. Although safety communication has been regarded as important for EM workers, there is a lack of quantitative analysis on this at a crew level. The present study provides empirical research to reveal authentic safety communication networks and their connections with safety performance and personal attributes.
Multi-agent based safety computational experiment system for shield tunneling projects
Authors: Lu Hui , Qi Junxiong , Li Jue , Xie Yong , Xu Gangyan , Wang Hongwei
Published: August 2020

Purpose

In shield tunneling projects, human, shield machine and underground environment are tightly coupled and interacted. Accidents often occur under dysfunctional interactions among them. Therefore, this paper aims to develop a multi-agent based safety computational experiment system (SCES) and use it to identify the main influential factors of various aspects of human, shield machine and underground environment.

Design/methodology/approach

The methods mainly comprised computational experiments and multi-agent technologies. First, a safety model with human-machine-environment interaction consideration is developed through the multi-agent technologies. On this basis, SCES is implemented. Then computational experiments are designed and performed on SCES for analyzing safety performance and identifying the main influential factors.

Findings

The main influential factors of two common accidents are identified. For surface settlement, the main influential factors are ranked as experience, soil density, soil cohesion, screw conveyor speed and thrust force in descending order of influence levels; for mud cake on cutter, they are ranked as soil cohesion, experience, cutter speed and screw conveyor speed. These results are consistent with intuition and previous studies and demonstrate the applicability of SCES.

Practical implications

The proposed SCES provides comprehensive risk factor identification for shield tunneling projects and also insights to support informed decisions for safety management.

Originality/value

A safety model with human-machine-environment interaction consideration is developed and computational experiments are used to analyze the safety performance. The novel method and model could contribute to system-based safety research and promote systematic understanding of the safety performance of shield tunneling projects.
The specialty coffee trading company (TSTC): contratos de futuro y opciones
Authors: Jenkins Mauricio , Barbosa Francisco
Published: August 2020

Learning outcomes

Los principales objetivos pedagógicos del caso son: Ilustrar cómo empresas latinoamericanas que se dedican a la producción y cosecha de productos básicos (commodities) pueden integrarse verticalmente para apropiarse de una mayor proporción del valor creado a lo largo de la cadena productiva. Entender cómo los contratos de futuros y las opciones sobre productos básicos se pueden utilizar para cubrir riesgo de precio en posiciones largas o cortas en esos productos. Entender cómo los contratos de opciones agregan valor al mitigar riesgo en aquellos contextos en los que la contraparte posee opcionalidad. Discutir las implicaciones que tiene el llamado comercio justo para productores y comercializadores de productos básicos.

Case overview/synopsis

En el caso, Hernán Arosamena, gerente financiero de The Specialty Coffee Trading Co. (TSCT) enfrenta el reto de diseñar una estrategia efectiva para mitigar los riesgos de precio que está generando la creciente demanda del denominado café de comercio justo (fair trade coffee) para la empresa. Ante esta situación, Hernán Arosamena decide revisar la forma en que típicamente la empresa ha gestionado el riesgo de precio en sus transacciones comerciales mediante el uso de los contratos de futuros para luego incorporar los elementos adicionales que transacciones con granos de café de comercio justo puede conllevar. La estrategia típica de mitigación al riesgo de precio involucra el uso de contratos de futuro de café en posiciones largas y cortas para lograr que la empresa obtenga el margen de comercialización deseado en sus negociaciones de compra/venta de granos de café. Para poder mitigar la exposición al riesgo de fluctuaciones en el precio del café cuando la empresa comercializa granos de café de comercio justo requiere el empleo (además) de opciones de venta (put).

Complexity academic level

El caso es apropiado para estudiantes matriculados en cursos o programas especializados tanto de pregrado como de posgrado.

Supplementary materials

El caso esta acompañado por una nota de enseñanza detallada que incluye los diferentes tópicos que pueden discutirse y analizarse, así como el orden en que deberían cubrirse.

Código de área:

CSS 5: International Business.
Assessment of technology strategies for sustainable tourism planning
Authors: Gore Surabhi , Borde Nilesh , Hegde Desai Purva
Published: August 2020

Purpose

An essential requirement for tourism planning and policymaking is to review past strategies. The development of future roadmaps depends on a robust strategy validation process. The research analyses the technology strategies in Goa from 1962–2017 and highlights the impact of technology on tourism in Goa.

Design/methodology/approach

The paper presents a unique methodology that integrates tourism area life cycle (TALC) and Mintzberg’s strategy analysis framework to evaluate strategies at a tourism destination.

Findings

The findings show that most technological advancements have taken place during the period 1989–2008. Both deliberate and emergent strategies were identified. Development of technology altered the type of tourism practiced in Goa. The use of internet facilitated the growth of tourism.

Research limitations/implications

This study clarifies the styles of public planning for tourism. It provides the foundation for strategic planning process.

Practical implications

Effective and efficient use of policy through technology road mapping can aid in co-creating a sustainable tourism destination for the future.

Social implications

The strategic evaluation framework can be used in any tourism destinations to identify past strategies and assess its impact on the future.

Originality/value

The paper presents a unique methodology that integrates TALC and Mintzberg’s strategy analysis framework to evaluate strategies at a tourism destination. The research proposes a strategic evaluation process that recognizes past strategies to validate the strategic analysis process.
Globalisation, crime and wage inequality: a theoretical analysis
Authors: Gupta Manash Ranjan
Published: August 2020

Purpose

This study aims to focus on the effects of economic globalisation programme on the problems of criminal activities and on the degree of skilled–unskilled wage inequality.

Design/methodology/approach

A competitive general equilibrium model of a small open economy is developed. Unskilled labour moves from the production sector to the criminal sector. Those who join the criminal sector snatch a part of capitalists’ income and skilled workers’ income to finance their consumption and face positive probability of being caught and punished. The size of the criminal sector and the rental rate on capital are simultaneously determined in the short-run equilibrium of this model where factor endowments are exogenously given at a particular point of time.

Findings

An increase in the capital endowment resulting from an exogenous foreign capital inflow raises demand for labour and wage rates in both the sectors. So, it lowers the rental rate on capital and thus aggravates the problem of skilled–unskilled wage inequality because the skilled labour using sector is more capital intensive than the other production sector. However, it may lower the size of the criminal sector and thus may raise the level of the gross domestic product.

Originality/value

There exists substantial theoretical works on the problem of skilled–unskilled wage inequality, but none of these works focuses on the general equilibrium allocation of unskilled labour to the criminal sector. On the other hand, existing models specialised to analyse theoretical implications of crime and punishment do not focus on the interaction between crime and wage inequality.
A study of equality of educational opportunity in Nepal using logistic regression analysis
Authors: Ezaki Naruho
Published: August 2020

Purpose

While privatisation in education is expanding, the number of children transferring from public to private schools seeking high-quality education has increased. This study examined equality of educational opportunity, focussing on the attributes of individual children and their familial backgrounds. The target country is Nepal, which has been facing an educational disparity problem between public and private schools.

Design/methodology/approach

This study performed a logistic regression analysis with the objective variable as the binary capability to attend a private school and analysed the differences between children who attended public versus private schools. Semi-structured interviews with subjects and teachers and home-visit surveys were conducted to collect and confirm data.

Findings

This study revealed that particular children were excluded from seeking high-quality education in form of attending private schools. These children's characteristics correspond to lower economic status, illiterate mothers, being only children and female. Moreover, the study observed changes in awareness due to the modernisation and globalisation of Nepali society and growing enthusiasm for education, amongst others.

Originality/value

Research on privatisation and access to quality education, which has attracted scholarly attention in recent years, requires a broader scope regarding target countries and more in-depth analyses. This study focussed on Nepal since, in the country, the phenomenon of children leaving public for private schools is prominent and little research has been conducted on this context. Additionally, since the study gathered extensive data on individual children and did not rely on secondary data, it was possible to perform an in-depth analysis and accurately portray the real situation faced by Nepali children.