bluuebunny/crossref_metadata_2025_split huggingface dataset:
(p)ppGpp is required for Virulence ofShigella flexneri
Authors: Kago Grace , Turnbough Charles L. , Payne Shelley M. 
Published: August 2023

ABSTRACTInfection by the enteric pathogenShigella flexnerirequires transit through the gastrointestinal tract and invasion of and replication within the cells of the host colonic epithelium. This process exposes the pathogen to a range of diverse microenvironments. Further, the unique composition and physical environment of the eukaryotic cell cytosol represents a stressful environment forS. flexneri, and extensive physiological adaptations are needed for the bacterium to thrive. In this work, we show that disrupting synthesis of the stringent response alarmone (p)ppGpp inS. flexneridiminished expression of key virulence genes, includingipaA, ipaB, ipaCandicsA, and it reduced bacterial invasion and intercellular spread. Deletion of the (p)ppGpp synthase generelAalone had no effect onS. flexnerivirulence, but disruption of bothrelAand the (p)ppGpp synthase/hydrolase genespoTresulted in loss of (p)ppGpp synthesis and virulence. While therelA spoTdeletion mutant was able to invade a cultured human epithelial cell monolayer, albeit at reduced levels, it was unable to maintain the infection and spread to adjacent cells, as indicated by loss of plaque formation. Complementation withspoTon a plasmid vector restored plaque formation. Thus, SpoT alone is sufficient to provide the necessary level of (p)ppGpp for virulence. These results indicate that (p)ppGpp is required forS. flexnerivirulence and adaptation to the intracellular environment, adding to the repertoire of signaling pathways that affectShigellapathogenesis.
A Standardized Protocol for Sample Preparation for Scanning Electron Microscopy (SEM) to Visualize Extrachromosomal DNA (ecDNA)
Authors: Madren Jillann , Chen Jingting , Dennis William , Ford Christina , White Kristen , Brunk Elizabeth 
Published: August 2023

AbstractExtrachromosomal DNA (ecDNA) are large (∼kilo to megabase) acentric, atelomeric, circular DNAs that are established cytogenetic markers for malignancy, hard-to-treat tumors and drug resistance. Often referred to as double minute chromosomes, ecDNA have been studied since the 1960s, primarily through molecular biology techniques, such as cytogenetics and fluorescence microscopy. More recently, next generation sequencing technologies present novel opportunities for identifying ecDNA. However, none of these approaches adequately address the architecture, size and composition of ecDNA within single cells. Developing an approach to systematically visualize ecDNA, confirm their circular architecture and determine their ultrastructure and composition is an urgent, unmet need. This work presents a protocol for visualizing ecDNA at high resolution using scanning electron microscopy (SEM). To this end, we have optimized an end-to-end procedure that involves preparing, processing and visualizing metaphase spread samples. This protocol was tested on five human cancer cell lines (COLO320DM, NCIH716, NCIH2170, SKGT2, SNU16), four of which express ecDNA in various amounts and one amplifies DNA via a homogeneous staining region (HSR). This work presents a standardized approach to preparing samples and visualizing ecDNA using SEM.SignificanceExtrachromosomal DNA (ecDNA) are proposed to have unique molecular traits, which include acentric, atelomeric and circular DNA. Standardized, high resolution microscopy approaches are in high demand to better understand structure-function relationships of ecDNA.
Tumor suppressor let-7 acts as a key regulator for maintaining pluripotency gene expression in Muse cells
Authors: Li Gen , Wakao Shohei , Kitada Masaaki , Dezawa Mari 
Published: August 2023

AbstractIn embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs), the expression of an RNA-binding pluripotency-relevant protein, LIN28, and the absence of its antagonist, the tumor-suppressor microRNA (miRNA) let-7, play a key role in maintaining pluripotency. Muse cells are non-tumorigenic pluripotent-like stem cells residing in the bone marrow, peripheral blood, and organ connective tissues as pluripotent surface marker SSEA-3(+). They express pluripotency genes, differentiate into triploblastic-lineage cells, and self-renew at the single cell level. Muse cells do not express LIN28 but do express let-7 at higher levels than in iPSCs. In Muse cells, we demonstrated that let-7 inhibited the PI3K-AKT pathway, leading to sustainable expression of the key pluripotency regulator KLF4 as well as its downstream genes,POU5F1,SOX2, andNANOG. Let-7 also suppressed proliferation and glycolysis by inhibiting the PI3K-AKT pathway, suggesting its involvement in non-tumorigenicity. Furthermore, the MEK/ERK pathway is not controlled by let-7 and may have a pivotal role in maintaining self-renewal and suppression of senescence. The system found in Muse cells, in which the tumor suppressor let-7, but not LIN28, tunes the expression of pluripotency genes, might be a rational cell system conferring both pluripotency-like properties and a low risk for tumorigenicity.
SUMOnet: Deep Sequential Prediction of SUMOylation Sites
Authors: Dilekoglu Berke , Tastan Oznur 
Published: August 2023

AbstractSUMOylation is a reversible post-translational protein modification in which SUMOs (small ubiquitin-like modifiers) covalently attach to a specific lysine residue of the target protein. This process is vital for many cellular events. Aberrant SUMOylation is associated with several diseases, including Alzheimer’s, cancer, and diabetes. Therefore, accurate identification of SUMOylation sites is essential to understanding cellular processes and pathologies that arise with their disruption. We present three deep neural architectures, SUMOnets, that take the peptide sequence centered on the candidate SUMOylation site as input and predict whether the lysine could be SUMOylated. Each of these models, SUMOnet-1, -2, and -3 relies on different compositions of deep sequential learning architectural units, such as bidirectional Gated Recurrent Units(biGRUs) and convolutional layers. We evaluate these models on the benchmark dataset with three different input peptide representations of the input sequence. SUMOnet-3 achieves 75.8% AUPR and 87% AUC scores, corresponding to approximately 5% improvement over the closest state-of-the-art SUMOylation predictor and 16% improvement over GPS-SUMO, the most widely adopted tool. We also evaluate models on a challenging subset of the test data formed based on the absence and presence of known SUMOylation motifs. Even though the performances of all methods degrade in these cases, SUMOnet-3 remains the best predictor in these challenging cases.Availability and ImplementationThe SUMOnet-3 framework is available as an open-source project and a Python library athttps://github.com/berkedilekoglu/SUMOnet.
Reinforcing resilience on the supply side: the role of supplier capabilities
Authors: Akbar Bilal , Aslam Haris 
Published: August 2023

PurposeThis research study aims to investigate supplier integration's (SI) impact on supply-side resilience (SSR) while considering the intervening role of supplier sustainability and supplier flexibility (SF).Design/methodology/approachGrounded in the dynamic capabilities view (DCV), the study posits that integration of the focal firm with firm's suppliers leads to sustainability on the supplier's side, which makes the firms more flexible to work with during disruptive circumstances, resulting in resilience on the supply side. The hypotheses are tested on the data of 181 manufacturing firm supply chain managers from a developing country.FindingsThe research findings confirmed the hypothesized model suggesting that SI positively impacts SSR. The results also confirm the existence of sequential mediation of supplier sustainability and SF between the SI–SSR relationship.Practical implicationsThe results of this study show that SI is the primary capability for organizations seeking SSR. Furthermore, the supply-side capabilities, to be effective, are developed in a specific order.Originality/valueThis research advances the body of knowledge by identifying the underlying mechanisms through which SI augments SSR.
A hedonic analysis of the determinants of hotel room rates in the Greater Gaborone Region (Botswana) using quantile regression
Authors: Chatibura Delly Mahachi 
Published: August 2023

PurposeThe purpose of this study is to examine the influence of key hotel attributes on the room rates of selected hotels in the Greater Gaborone Region, Botswana.Design/methodology/approachUsing hedonic pricing analysis, the effect of eight attributes collected from 80 standard double rooms on Booking.com in the area was analysed using quantile regression.FindingsThe estimated results from quantile regression suggested the importance of the 10th quantile as the best predictor of hotel room price distribution. Overall, the presence of a fitness centre and the availability of meeting and conference facilities were positively significant for the lowest- and premium-priced hotels, respectively.Research limitations/implicationsThe study advanced the literature in hedonic pricing models by confirming the applicability of hotel room rate attribute research in unexplored environments.Practical implicationsHotel managers should be aware of the influence of key attributes, such as meeting and conference space availability and locational factors, on the pricing decisions of room rates in the Greater Gaborone Region. The study also presented opportunities for business-to-business marketing between hotel and tour operators in the region.Originality/valueThe study is one of the few that uses quantile regression in the hedonic pricing analysis of hotel room rates.
Key performance indicators in short-term rental accommodation
Authors: Pardinha João , Mota Jorge , Costa Rui Augusto 
Published: August 2023

Purpose
The boom of new players in the accommodation sector has led to an increase in the level of competitiveness and has highlighted the importance of using key performance indicators (KPIs) in organisational decision-making processes as efficient tools for thriving in the growingly competitive environment. This study aims to assess the use of KPIs by owner-managers of small and medium-sized short-term rental accommodation (STRA) units.

Design/methodology/approach
To achieve this aim, this research encompasses two different primary data collection methods conducted in 2021. Firstly, from April to May, a set of exploratory interviews with experts within the STRA domain was planned. Secondly, an intensive data collection, from June to September, included an online questionnaire with close-ended questions to a sample of all the companies that manage STRA units in Portugal.

Findings
These managers tend to use more widely financial and operational KPIs that depict relationships with guests and reflect the activity of the STRA units, the external environment and the innovation level. Moreover, younger managers and those with higher levels of education tend to use a “monitoring review of digital platforms” KPI, while less experienced managers use financial and operational KPIs and senior and higher experienced managers place greater value on KPIs associated with customer relationships.

Originality/value
STRA units hold a very relevant position in the hospitality industry, and it is urgent to generate more information to better understand this growing subsector. This research contributes to the literature providing evidence on the importance of KPI to STRA units, for owner-managers and for urban tourism, considering their growth, proliferation and importance for the planning of cities by destination management organisations.
Understanding the role of Instagram in young adult consumers' purchase and post-purchase evaluation behaviors
Authors: Hood Sara Lewis , Thoney-Barletta Kristin Anne , Rothenberg Lori 
Published: August 2023

PurposeThis study explored the role that Instagram, a prominent social media platform, plays in the consumer decision-making process of young adults (age 18–27 years) in the United States as they shop online for apparel and interact with the digital profiles of apparel brands. Specifically, this study compared consumers' purchase and post-purchase evaluation behaviors on Instagram between Millennials and Generation Z, and investigated the role of consumers' trust of Instagram on these behaviors.Design/methodology/approachA survey instrument was developed to explore critical variables, including consumers' purchase and post-purchase evaluation behaviors on Instagram, consumers' trust of Instagram, and demographic factors, adapting previous works from Ko (2018), Djafarova and Rushworth (2017), and Herrando et al. (2019). Survey responses were collected via the Qualtrics participant panel service (N = 226), then coded and analyzed using JMP Pro (Version 14.2).FindingsResults indicated that statistically significant mean differences were present among several key variables, including between Millennial and Generation Z post-purchase behaviors on Instagram, willingness to share feedback about a brand experience on Instagram, and trust of content on Instagram. Additionally, it was determined that purchase and post-purchase behaviors on Instagram are significantly different depending on whether or not a consumer trusts Instagram and the content therein.Originality/valueWhile online consumer behaviors have been previously studied, the impact of young adults' Instagram usage on their purchase and post-purchase evaluation behaviors in the apparel sector had not been thoroughly examined. The findings from this study provide meaningful insights on the purchase and post-purchase behaviors on Instagram of young adult consumers from different generational cohorts. They demonstrate that developing trust with young adults is critical to the success of brands trying to reach this demographic on Instagram.
Trust, pandemic and communication: an analysis of the COVID-19 pandemic from an autopoietic systems perspective
Authors: Wahyuni Hermin Indah 
Published: August 2023

PurposeThis article seeks to discuss trust within the context of public health crises using an autopoietic systems perspective that positions communication as one of its core concepts. This article will explore trust studies conducted during public health crises in this Millennium (from SARS to COVID-19 pandemics), including their problems; briefly summarize Luhmann's concept of Vertrauen; and use this concept to analyze trust issues during the COVID-19 pandemic.Design/methodology/approachThis article will explore trust studies conducted during public health crises from SARS to COVID-19 pandemics, including their problems. The perspective used is an explication of Niklas Luhmann's theory regarding Vertrauen which was derived as a framework for reading empirical facts on trust issues during the COVID-19 pandemic. The research design and exploration stages were inspired by the theory of autopoiesis systems by Niklas Luhmann.FindingsFrom a systems perspective, the COVID-19 pandemic has highlighted the extraordinary complexity of the linkages between social systems. Trust will continue to evolve dynamically as new variants emerge in society. Consequently, the pandemic has provided the momentum necessary for maximally exploring the concept of trust. Indonesia thus experienced significant obstacles when making and implementing disaster mitigation policies. Owing to the lack of a trust system, greater emphasis was given to control and power. There has been little preparedness to create and reinforce public trust, and this in turn has stifled efforts to stop the spread of COVID-19.Originality/valueThis study of trust, communication and public health crises has provided space to reflect on the development of trust within the social system. This study shows that trust can prove to be a very important factor in resolving a crisis. However, the complexity of the interrelationships of the social system can affect the quality of trust. The context of Indonesia's social system which is very complex due to population density and the dynamics of the development of its social system which is very diverse as an archipelagic country has contributed to the originality of the study of trust in times of crisis in a growing contemporary society.
Application of biosensors in aflatoxins detection in food: a review
Authors: Narjabadi Fam Shakiba , Massoud Ramona 
Published: August 2023

Purpose
Food safety is among the most important topics in the world. According to WHO guidelines, aflatoxins are one of the most hazardous food toxins. Therefore, their detection in food products seems crucial due to health problems. The purpose of this paper is to discuss the different types of biosensors in aflatoxin determination.

Design/methodology/approach
Traditional detection methods are time consuming and expensive. As fast and accurate detection is important in monitoring food contaminants, alternative analytical methods would be essential. Biosensors are the intelligent design of sensitive sensors for precise detection of toxins in a short time. Various biosensors are being applied for aflatoxins detection in food products with many advantages over the traditional methods.

Findings
Biosensors are cost-effective, stable and have possessed high selectivity, specificity and accuracy in aflatoxins detection. Applying biosensors has been increased recently, so biosensing methods (optical, electrochemical, piezoelectrical, immunosensors, surface plasmon resonance and calorimetric) are discussed along with their advantages in this article.

Research limitations/implications
More efforts should be occurred to detect and decrease the aflatoxins by biosensors, and some traits like accuracy and selectivity would be the purpose of future projects. The combination of various techniques would also help in toxin detection issue in food products, so high efforts in this regard are also required for the upcoming years.

Originality/value
This article also reviews different types of biosensors simultaneously and explains their specificity for aflatoxin determination in different food products and also the future trends and requirements.
Natural and synthetic drugs as eco-friendly and sustainable corrosion inhibitors for metals: a review
Authors: Njoku Chigoziri N. , Maduoma Temple Uzoma , Emori Wilfred , Odey Rita Emmanuel , Unimke Beshel M. , Yakubu Emmanuel , Anorondu Cyril C. , Udunwa Daniel I. , Njoku Onyinyechi C. , Oyoh Kechinyere B. 
Published: August 2023

Purpose
Corrosion is a major concern for many industries that use metals as structural or functional materials, and the use of corrosion inhibitors is a widely accepted strategy to protect metals from deterioration in corrosive environments. Moreover, the toxic nature, non-biodegradability and price of most conventional corrosion inhibitors have encouraged the application of greener and more sustainable options, with natural and synthetic drugs being major actors. Hence, this paper aims to stress the capability of natural and synthetic drugs as manageable and sustainable, environmentally friendly solutions to the problem of metal corrosion.

Design/methodology/approach
In this review, the recent developments in the use of natural and synthetic drugs as corrosion inhibitors are explored in detail to highlight the key advancements and drawbacks towards the advantageous utilization of drugs as corrosion inhibitors.

Findings
Corrosion is a critical issue in numerous modern applications, and conventional strategies of corrosion inhibition include the use of toxic and environmentally harmful chemicals. As greener alternatives, natural compounds like plant extracts, essential oils and biopolymers, as well as synthetic drugs, are highlighted in this review. In addition, the advantages and disadvantages of these compounds, as well as their effectiveness in preventing corrosion, are discussed in the review.

Originality/value
This survey stresses on the most recent abilities of natural and synthetic drugs as viable and sustainable, environmentally friendly solutions to the problem of metal corrosion, thus expanding the general knowledge of green corrosion inhibitors.
Study of parametric interaction during fused filament fabrication (FFF) using interpretive structural modelling (ISM) followed by experimental analysis
Authors: Sharma Shekhar , Datta Saurav , Roy Tarapada , Mahapatra Siba Sankar 
Published: August 2023

Purpose
Fused filament fabrication (FFF) is a type of additive manufacturing (AM) based on materials extrusion. It is the most widely practiced AM route, especially used for polymer-based rapid prototyping and customized product fabrication in relation to aerospace, automotive, architecture, consumer goods and medical applications. During FFF, part quality (surface finish, dimensional accuracy and static mechanical strength) is greatly influenced by several process parameters. The paper aims to study FFF parametric influence on aforesaid part quality aspects. In addition, dynamic analysis of the FFF part is carried out.

Design/methodology/approach
Interpretive structural modelling is attempted to articulate interrelationships that exist amongst FFF parameters. Next, a few specimens are fabricated using acrylonitrile butadiene styrene plastic at varied build orientation and build style. Effects of build orientation and build style on part’s ultimate tensile strength, flexure strength along with width build time are studied. Prototype beams (of different thickness) are fabricated by varying build style. Instrumental impact hammer Modal analysis is performed on the cantilever beams (cantilever support) to obtain the natural frequencies (first mode). Parametric influence on natural frequencies is also studied.

Findings
Static mechanical properties (tensile and flexure strength) are greatly influenced by build style and build orientation. Natural frequency (NF) of prototype beams is highly influenced by the build style and beam thickness.

Originality/value
FFF built parts when subjected to application, may have to face a variety of external dynamic loads. If frequency of induced vibration (due to external force) matches with NF of the component part, resonance is incurred. To avoid occurrence of resonance, operational frequency (frequency of externally applied forces) must be lower/ higher than the NF. Because NF depends on mass and stiffness, and boundary conditions, FFF parts produced through varying build style may definitely correspond to varied NF. This aspect is explained in this work.