Miracle-dz/UniFAR-FTUs huggingface dataset:
Anthrax lethal toxin unfolding and translocation via a charge-state ratchet

Author(s): Brown, Michael Joseph | Advisor(s): Krantz, Bryan | Abstract: A fundamental problem in biochemistry is how molecular machines convert chemical potential energy into mechanical work. Here, this problem is addressed in terms of how a proton gradient (ΔpH) drives anthrax toxin transmembrane protein translocation with a given directionality. One model to explain this phenomenon is a charge-state Brownian ratchet, wherein movement is biased by asymmetries across the membrane. Acidic residues in the substrate are protonated on the lower pH starting side, thus allowing them to pass through the cation-selective protective antigen (PA) channel. Movement can occur in either direction according to Brownian motion, but acidic residues that reach the higher pH of the destination are deprotonated, preventing retrotranslocation and resolving movement in one direction.This model is probed through the use of planar lipid bilayer electrophysiology to analyze the charge requirements of the model substrate LFN, the binding domain of the natural substrate lethal factor. Acidic residues are necessary and sufficient for ΔpH-driven translocation provided the starting side pH is low enough to sufficiently protonate the residues. Their position in the sequence, just before LFN's folded domain, plays a key role in substrate unfolding. Basic charges are important for initiation into the channel and to chaperone deprotonated acidic residues during translocation. Further work by Sarah Wynia-Smith confirms the importance of acidic residues just before LFN's folded domain and points to the existence of electrostatic translocation barriers in the PA channel. I identify key residues in the upper portion of the channel's β barrel that contribute to its cation selectivity. These residues also prove to play a significant role in substrate initiation and translocation, supporting the role for a charge gate in the channel that prevents retrotranslocation.Finally, secondary structure of the translocating substrate is analyzed. LFN translocates in a compact helical state nucleated by the channel's α clamp, a nonspecific helix-binding site recently identified by Geoffrey Feld. α clamp-induced helix formation lowers a previously identified but uncharacterized translocation barrier, and substrates that cannot form helices cannot translocate. This suggests a mechanism wherein helix melting, coupled to the electrostatic ratchet, drives translocation-coupled substrate unfolding.
Combatting Substandard and Counterfeit Medicines in the Nigerian Drug Market: How Industrial Pharmacists Can Rise Up to the Challenge

Abstract Substandard and counterfeit medicines (SCMs) are a major public health threat in Africa. In Nigeria, the manufacture and distribution of substandard and counterfeit medicines in the drug market are booming, despite the efforts of law enforcement agencies to crack down on criminal syndicates over the years. The current situation has been exacerbated due to factors tied to unregulated open drug markets, lack of counterfeit detection technology, poor local pharmaceutical manufacturing capacity, and porous cross-border monitoring and surveillance systems. However, industrial pharmacists have a key role to play in combatting the production and circulation of SCMs in the Nigerian drug market. In this commentary, we examine the prevalence of SCMs in Nigeria and proffer feasible recommendations that industrial pharmacists can leverage to ensure its effective containment.
Worth from Waste: Utilizing a Graphite-Rich Fraction from Spent Lithium-Ion Batteries as Alternative Reductant in Nickel Slag Cleaning

One possible way of recovering metals from spent lithium-ion batteries is to integrate the recycling with already existing metallurgical processes. This study continues our effort on integrating froth flotation and nickel-slag cleaning process for metal recovery from spent batteries (SBs), using anodic graphite as the main reductant. The SBs used in this study was a froth fraction from flotation of industrially prepared black mass. The effect of different ratios of Ni-slag to SBs on the time-dependent phase formation and metal behavior was investigated. The possible influence of graphite and sulfur contents in the system on the metal alloy/matte formation was described. The trace element (Co, Cu, Ni, and Mn) concentrations in the slag were analyzed using the laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) technique. The distribution coefficients of cobalt and nickel between the metallic or sulfidic phase (metal alloy/matte) and the coexisting slag increased with the increasing amount of SBs in the starting mixture. However, with the increasing concentrations of graphite in the starting mixture (from 0.99 wt.% to 3.97 wt.%), the Fe concentration in both metal alloy and matte also increased (from 29 wt.% to 68 wt.% and from 7 wt.% to 49 wt.%, respectively), which may be challenging if further hydrometallurgical treatment is expected. Therefore, the composition of metal alloy/matte must be adjusted depending on the further steps for metal recovery.
Creative Cities and Knowledge Management Approach to Culture-Based Urban Regeneration in Slovakia: A Model

The term "Creative City" emerged in the 90s of the 20th century reflecting the trend of transforming post-industrial cities into new creative urban centres - bases for knowledge intensive firms, highly-skilled workers and major cultural assets. The concept of culture-based urban regeneration describes a scheme where culture is purposely employed as a vehicle for an overall urban and social revitalization. The paper addresses innovative processes within culture-based urban regeneration projects in three Slovak cities - Bratislava, Zilina and Kosice - under the concept of creative city. The focus is on the implementation of a tailor-made multi-factor knowledge management model with the aim of exploring the knowledge management practices in urban development projects dealing with the adaptive re-use of industrial and cultural heritage based on the non-profit bottom-up initiatives. properties a of taking into personal fulfilment, the and and (4) described by -
Converting olefins to propene: Ethene to propene and olefin cracking

ABSTRACT Demand for propene as a petrochemical building block keeps growing, while its availability has been decreased by the adoption of shale gas resources, among others. Efforts to optimize its production by conventional means (including modified fluid catalytic cracking) and new on-purpose production technologies (including ethene to propene (ETP) and olefin cracking) are being pursued. This work reviews the progress made on olefin conversion processes, including the ETP reaction, which is still under development, and the cracking of butenes and higher olefins (C5–C8). The factors analyzed include the catalytic performance of different zeolite materials and their modifications to increase catalyst stability, yield, and selectivity to propene, as well as the effect of operating conditions, reaction thermodynamics, and mechanisms involved. The work is complemented by a survey of commercial technologies and developments on olefin conversion processes.
Social Media, Messaging Apps, and Affective Polarization in the United States and Japan

ABSTRACT This study explores how emerging media platforms (i.e., social media and messaging apps) contribute to affective political polarization. We rely on cross-national data (USA and Japan), which allows us to explore the broader implications of how emerging media platforms contribute to political polarization in different cultural contexts. The results are very consistent; social media news use is positively related to affective polarization while messaging apps are negatively related in the USA and Japan. In addition, in the USA, the association of messaging app news and affective polarization is amplified by partisanship strength.
Trading off consumer preferences induced by cultural and colonial heritage: Lessons from New Rice for Africa (NERICA) in Casamance, Senegal

Breeders face the challenging task of tailoring crop varieties to complex consumer preferences shaped through culture and history. The Casamance rice sector in Senegal is an interesting case; while the region is endowed with a 3,000-year-old cultural heritage of African rice domestication, it has also been exposed to century-long colonial import substitution policies, leading to massive influx of cheap, broken Asian rice. Markets have responded to the amalgam of consumer preferences that have emerged as a result of cultural and colonial heritage by offering three standard grades of rice: 100 per cent broken, semi-broken (35–60 per cent broken), and unbroken. To disentangle the trade-off between indigenous and ‘imported’ traits and inform breeding priorities, we conducted framed field experiments with urban women in the Casamance. We assessed consumers’ revealed price premiums for replacing imported, broken Asian rice with three locally produced New Rice for Africa (NERICA) hybrids between African and Asian rice: (i) broken, fragrant NERICA 1; (ii) broken NERICA 4; and (iii) unbroken NERICA 6 featuring medium/bold grain shape. Consumers with genealogical lineages tracing back to the original domesticators of African rice put significantly higher value on locally produced NERICAs relative to immigrants from the north and northeast, who put premiums on ‘imported’ traits such as rice fragrance. Driven by preferences for both broken and unbroken rice, NERICA 6 outcompeted all other varieties as it mimics the grain shape of semi-broken rice while being unbroken. The latter exemplifies how breeders can strike an optimal compromise in the trade-off between cultural and colonial heritage-induced preferences.
Organization engagement: a review and comparison to job engagement

PurposeEmployee engagement has received a considerable amount of research attention over the last decade. However, most of the research has been on job or work engagement. Much less attention has been given to organization engagement, which is a distinct but related target of employee engagement. In this paper, we review the research on organization engagement and identify how it has been measured, its antecedents and consequences and how it compares to job engagement.Design/methodology/approachThis paper provides a narrative review of 40 studies that have measured organization engagement. Most of these studies have been published in the last five years, and they come from 20 different countries. The majority of studies also measured job or work engagement.FindingsMost studies used Saks' (2006) measure of organization engagement. Many antecedents have been found to be related to organization engagement; however, those most often studied and consistently related to organization engagement are organizational-related resources such as perceived organizational support (POS), justice perceptions, corporate social responsibility (CSR), organizational structural factors, organizational climate and HR practices. Organization engagement has been found to be positively related to job satisfaction, organizational commitment, organizational citizenship behavior (OCB), job performance and organizational performance and negatively related to intention to quit. Organization engagement has also been found to partially or fully mediate the relationship between antecedents and consequences. In comparison to job engagement, organization engagement scores tend to be lower, and there are meaningful differences in the antecedents and consequences of organization engagement and job engagement. A number of studies found that organization engagement was more strongly related to several of the consequences than job engagement.Practical implicationsThe results of this review indicate that organization engagement is as important if not more important than job engagement when it comes to its relationship to some of the consequences of employee engagement. Organizations should include a measure of organization engagement in employee surveys and focus on improving organization engagement by providing a supportive work environment, ensuring that employees have positive perceptions of justice, increasing CSR initiatives, providing a variety of human resources (HR) practices and improving organizational climate.Originality/valueThis paper provides the first comprehensive review of research on organization engagement and offers a new model of the antecedents and consequences of organization engagement and compares organization engagement to job engagement.
Are COVID-19 Data Reliable? A Quantitative Analysis of Pandemic Data from 182 Countries

When it comes to COVID-19, access to reliable data is vital. It is crucial for the scientific community to use data reported by independent territories worldwide. This study evaluates the reliability of the pandemic data disclosed by 182 countries worldwide. We collected and assessed conformity of COVID-19 daily infections, deaths, tests, and vaccinations with Benford’s law since the beginning of the coronavirus pandemic. It is commonly accepted that the frequency of leading digits of the pandemic data shall conform to Benford’s law. Our analysis of Benfordness elicits that most countries partially distributed reliable data over the past eighteen months. Notably, the UK, Australia, Spain, Israel, and Germany, followed by 22 different nations, provided the most reliable COVID-19 data within the same period. In contrast, twenty-six nations, including Tajikistan, Belarus, Bangladesh, and Myanmar, published less reliable data on the coronavirus spread. In this context, over 31% of countries worldwide seem to have improved reliability. Our measurement of Benfordness moderately correlates with Johns Hopkin’s Global Health Security Index, suggesting that the quality of data may depend on national healthcare policies and systems. We conclude that economically or politically distressed societies have declined in conformity to the law over time. Our results are particularly relevant for policymakers worldwide.
Cluster After 20 Years of Operations: Science Highlights and Technical Challenges

The Cluster mission was the first constellation using four identical spacecraft to study Sun‐Earth connection plasma processes. Using four spacecraft in a tetrahedron shape, it could measure, for the first time, 3D quantities such as electrical currents, plasma gradients or divergence of the electron pressure tensor and 3D structures such as boundaries, surface waves or vortices. Launched in pairs in July and August 2000, on two Soyuz rockets from Baikonur, the four spacecraft have been collecting data continuously for more than 20 years. The mission faced many challenges during the years of operations as some spacecraft subsystems had a lifetime of a few years beyond the initial two‐year mission. The major one was to operate without functioning batteries and to successfully pass short and long eclipses, up to 3 h long, without damaging the on‐board computers and transmitters and without freezing the fuel. More than 1,000 eclipses have been successfully passed since 2010 using a specially made procedure which switches off the complete spacecraft before entering into eclipse and switches it on when the Sun is again illuminating the solar panels. During 20 years, many discoveries and science results have been published in more than 2,700 scientific papers. A few highlights are presented here, focusing on how varying the spacecraft separation was essential to achieve the science goals of the mission. The Cluster Science Data System and the Cluster archive allows public access to all science data as well as spacecraft ancillary data.
Evaporation Kinetics of Polyol Droplets: Determination of Evaporation Coefficients and Diffusion Constants

In order to quantify the kinetics of mass transfer between the gas and condensed phases in aerosol, physicochemical properties of the gas and condensed phases and kinetic parameters (mass/thermal accommodation coefficients) are crucial for estimating mass fluxes over a wide size range from the free molecule to continuum regimes. In this study, we report measurements of the evaporation kinetics of droplets of 1‐butanol, ethylene glycol (EG), diethylene glycol (DEG), and glycerol under well‐controlled conditions (gas flow rates and temperature) using the previously developed cylindrical electrode electrodynamic balance technique. Measurements are compared with a model that captures the heat and mass transfer occurring at the evaporating droplet surface. The aim of these measurements is to clarify the discrepancy in the reported values of mass accommodation coefficient (αM, equals to evaporation coefficient based on microscopic reversibility) for 1‐butanol, EG, and DEG and improve the accuracy of the value of the diffusion coefficient for glycerol in gaseous nitrogen. The uncertainties in the thermophysical and experimental parameters are carefully assessed, the literature values of the vapor pressures of these components are evaluated, and the plausible ranges of the evaporation coefficients for 1‐butanol, EG, and DEG as well as uncertainty in diffusion coefficient for glycerol are reported. Results show that αM should be greater than 0.4, 0.2, and 0.4 for EG, DEG, and 1‐butanol, respectively. The refined values are helpful for accurate prediction of the evaporation/condensation rates.
Core‐shell architecture of NiSe2 nanoparticles@nitrogen‐doped carbon for hydrogen evolution reaction in acidic and alkaline media

Electrochemical water splitting is known to be one of the most potential pathways for hydrogen generation. However, this process is limited by the sluggish cathodic hydrogen evolution reaction (HER) kinetics. Nitrogen‐doped materials have been exploited for the development of efficient electrocatalysts because of their tunable electronic properties. Herein, we illustrate a facile route to construct the core‐shell architecture in NiSe2@nitrogen‐doped carbon (NiSe2@NC) as efficient catalysts for the HER. NiSe2@NC samples were prepared through a two‐step process involving pyrolysis and selenization at various temperatures from a nitrogen‐rich Ni‐based metal‐organic framework (MOF) precursor. NiSe2@NC‐500°C was considered as the optimal sample because it showed outstanding catalytic properties for the HER with low overvoltages of 161 and 220 mV to deliver a current density of 10 mA/cm2 in acidic and alkaline solutions, respectively. In addition, NiSe2@NC‐500°C exhibited excellent stability after 2000 cycles and 12 h of operation. The high catalytic performance was attributed to the synergistic effect of the core‐shell structure and the carbon layers doped with high pyridinic‐N content, which play a vital role in providing a large number of active centers, imparting high conductivity, and enhancing the durability of the electrocatalyst. This account may open an approach to the design and fabrication of low‐cost electrode materials for HER.
Sustainability Transparency and Trustworthiness of Traditional and Blockchain Ecolabels: A Comparison of Generations X and Y Consumers

Consumers and professionals realize the importance of adopting social and environmental responsibility, but it is not easy for companies to implement transparent sustainability strategies that consumers can trust. Thus, it is often hard for consumers to compare brands to make conscious sustainability decisions. Blockchain technology is proposed as a bridge between ecolabels and industry initiatives as this technology provides the transparency of sustainable business practices. The objective of this study is to examine the effects of effectiveness, knowledge of the sustainability initiative, and trust in claims made by a company in ecolabels (i.e., traditional and blockchain ecolabels) on intention to buy products by comparing Generations X and Y. A total of 200 participants completed the survey. The results indicated that both the trust and knowledge measures were higher for the blockchain label than for the traditional ecolabel for Generation Y. Thus, the companies should determine how to effectively integrate this technology to the mutual benefit of the retailer and consumer by different generations.
Active control of vibrations of piezoelectric‎ rectangular nanocomposite micro plates reinforced with graphene platelet in thermal ambient considering the structural damping

Abstract This paper investigates on the active control ‎of vibrations of rectangular nanocomposite micro plates reinforced with graphene platelet bonded with piezoelectric‎ layers in thermal environment regarding the structural damping. The micro plate is subjected to a transverse load. The thermo-mechanical features of the reinforced layers are determined employing the Halpin-Tsai micromechanical model. The first order shear deformation theory is accompanied by the modified couple stress theory to derive the motion equations of the micro plate. The Ritz technique is applied to the governing equations to discretize the equations of motion. In order to active control ‎of vibrations of the micro plate, a closed-loop PD-controller is proposed. For the sake of determination of the transient response, the Newmark- direct integration technique is applied to the discretized governing equations of motion ensuing from the Ritz technique. The present findings are validated with the available data in the literature. A parametric study is established to shed light on the impression of the material length scale parameter, the boundary condition type, the graphene platelet distribution pattern and its weight fraction, and the control gain values on the dynamic response of the micro plate when it is subjected to a pulse-uniformly distributed transverse force. The results illustrate the more effectiveness of the designed PD controller for X-GPL micro plates with four clamped boundaries especially when the size dependency is incorporated into the formulation. Moreover, the PD controller performance boosts up at higher temperatures.
Dynamic 2H irrigation pulse labelling reveals rapid infiltration and mixing of precipitation in the soil and species‐specific water uptake depths of trees in a temperate forest

Understanding the movement of water in terrestrial ecosystems and determining the soil depths from which mature trees take up water has become an important research priority. Here, we test the suitability of a dynamic 2H pulse‐labelling experiment for assessing (1) the fate of a simulated precipitation event as it moves through the ecohydrological system and (2) the water uptake depths of different tree species in a mature temperate forest. We applied 2H‐labelled water as a single pulse to the top soil using a sprinkler system and then allowed it to infiltrate into deeper soil layers by washing it through the soil column with a sequence of non‐2H‐labelled irrigation pulses. We then followed this 2H‐enriched irrigation pulse over a period of 81 days in different depths of the soil and in the xylem of four tree species (Fagus sylvatica, Quercus petraea, Picea abies and Pinus sylvestris). Our experiment shows infiltration and mixing of the irrigation pulse in the soil occurs within a few days. Furthermore, we found that tree species differed significantly in their use of shallow (−10‐ to −30‐cm soil depth) and deep (−80‐cm soil depth) soil water. We also found immediate uptake of infiltrating mobile soil water by trees, which questions the recently established two‐water‐worlds hypothesis. Our study demonstrated that a dynamic 2H‐labelled irrigation pulse is a useful approach to (1) assess how water from a precipitation event infiltrates into a forest ecosystem and (2) assess the water uptake depths of different temperate tree species.