bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improving the flexibility of Genetically Encoded Voltage Indicators via intermolecular FRET
Authors: Leong Lee Min , Kang Bok Eum , Baker Bradley 
Published: August 2020

AbstractA 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.
A Unified Framework for Lineage Tracing and Trajectory Inference
Authors: Forrow Aden , Schiebinger Geoffrey 
Published: August 2020

AbstractUnderstanding 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

AbstractLymphatic 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

AbstractSleep 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

AbstractMicroRNAs (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.
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

PurposeThe 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/approachInternet 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.FindingsTherefore, 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/valueThe 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

PurposeDespite 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/approachThe 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.FindingsThe 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/valueConceptualizing 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

PurposePrevious 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/approachCase 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.FindingsThe 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 implicationsThe 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/valueThis 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

PurposeIn 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/approachThe 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.FindingsThe 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 implicationsThe proposed SCES provides comprehensive risk factor identification for shield tunneling projects and also insights to support informed decisions for safety management.Originality/valueA 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.