bluuebunny/crossref_metadata_2025 huggingface dataset:
DIY OCEANOGRAPHY • A Simple and Inexpensive Method for Manipulating Dissolved Oxygen in the Lab
Authors:   Dauphin Island Sea Lab, Gadeken Kara , Dorgan Kelly
Published: April 2021

Changes in dissolved oxygen concentration can cause dramatic shifts in chemical, biological, and ecological processes in aquatic systems. In shallow coastal areas, this can happen on short timescales, with oxygen increasing during the day due to photosynthesis and declining at night due to respiration. We present a system controlled by an Arduino microprocessor that leverages the oxygen-consuming capacity of sediments to manipulate dissolved oxygen in an aquarium tank to planned concentrations. With minor adjustments to the Arduino code, the system can produce a variety of dissolved oxygen patterns, including a diel cycle. Designed to be user-friendly and scalable if needed, the system uses easily acquired, low-cost electronic and aquarium components. Its simplicity and accessibility permit deeper exploration of the effects of dissolved oxygen variability in aquatic systems, and the use of Arduino code and basic electronics makes it a potential tool for teaching experimental design and instrument fabrication.
A Comprehensive Review of 4(1H)-Quinolones and 4(1H)-Pyridones for the Development of an Effective Antimalarial
Authors: H. Asakawa Ami , Manetsch Roman
Published: April 2021

Malaria is a global public health issue. Despite the efforts in malaria prevention, nearly half the world’s population is at risk of infection. Until present-day, researchers are struggling to design and discover an efficacious antimalarial. In comparison to most common antimalarial chemotypes that eliminate erythrocytic stages of P. falciparum, 4(1H)-quinolones and 4(1H)-pyridones exhibit antimalarial activity against multiple stages of the parasite. They have potential to treat blood stages of multidrug resistant P. falciparum malaria, eradicate dormant exoerythro stages of relapsing malaria species (P. vivax), and prevent transmission of infectious gametocytes to mosquitoes. However, thus far, the advancement of these chemotypes towards pre-clinical and clinical development has been impeded due to poor physicochemical properties, poor oral bioavailability, and poor dose-proportionality limiting preclinical safety and toxicity studies. Despite all these challenges, 4(1H)-quinolones and 4(1H)-pyridones continue to be at the forefront for the development of the next-generation antimalarials as they would have tremendous global public health impact and could significantly enhance current malaria elimination efforts.
Progress on Experimental Study of Melt Pool Flow Dynamics in Laser Material Processing
Authors: Xiao Xianfeng , Lu Cong , Fu Yanshu , Ye Xiaojun , Song Lijun
Published: April 2021

Laser material processing has becoming a rapid developing technology due to the flexibility of laser tool. Melt pool is the main product from the interaction between laser and material and its features has a great impact on the heat transfer, solidification behavior, and defects formation. Thus, understanding changes to melt pool flow is essential to obtain good fabricated product. This chapter presents a review of the experimental studies on melt pool flow dynamics for laser welding and laser additive manufacturing. The mechanisms of melt pool convection and its principal affecting factors are first presented. Researches on melt flow visualization using direct and indirect experimental methods are then reviewed and discussed.
Network-on-Chip Topologies: Potentials, Technical Challenges, Recent Advances and Research Direction
Authors: A. Alimi Isiaka , K. Patel Romil , Aboderin Oluyomi , M. Abdalla Abdelgader , A. Gbadamosi Ramoni , J. Muga Nelson , N. Pinto Armando , L. Teixeira António
Published: April 2021

Integration technology advancement has impacted the System-on-Chip (SoC) in which heterogeneous cores are supported on a single chip. Based on the huge amount of supported heterogeneous cores, efficient communication between the associated processors has to be considered at all levels of the system design to ensure global interconnection. This can be achieved through a design-friendly, flexible, scalable, and high-performance interconnection architecture. It is noteworthy that the interconnections between multiple cores on a chip present a considerable influence on the performance and communication of the chip design regarding the throughput, end-to-end delay, and packets loss ratio. Although hierarchical architectures have addressed the majority of the associated challenges of the traditional interconnection techniques, the main limiting factor is scalability. Network-on-Chip (NoC) has been presented as a scalable and well-structured alternative solution that is capable of addressing communication issues in the on-chip systems. In this context, several NoC topologies have been presented to support various routing techniques and attend to different chip architectural requirements. This book chapter reviews some of the existing NoC topologies and their associated characteristics. Also, application mapping algorithms and some key challenges of NoC are considered.
Kierkegaard’s Response to the Hegelian Necessity of the Past
Authors: Davidshofer Claudine ,   Philosophy Documentation Center
Published: April 2021

This article analyzes the “Interlude” in Kierkegaard’s Philosophical Fragments. In particular, it examines Johannes Climacus’s response to Hegel’s view that a past actuality is necessary. I provide an in-depth analysis of Hegel’s view of modality (possibility, actuality, necessity) and of what he means when he says that a past actuality is necessary. In contrast to the standard scholarly interpretation, I argue that Climacus need not reject Hegel’s view because Hegel’s view of the necessity of the past is not so controversial or difficult to accept. Finally, I show that Climacus’s main critique is that we cannot know the past as necessary in any meaningful way. He worries that we might get so preoccupied with the futile task of trying to know the Hegelian necessity of the past that we forget to personally appropriate the past in a way that can help us live in the present.
The Artifact of Non-Humanity
Authors: Kolozova Katerina ,   DePaul University
Published: April 2021

The scope of the paper is to present the concept of the radical dyad of the “non-human,” in an attempt to think radical humanity in terms of Marxian materialism, which is the product of approaching Marx’s writings on “the real” and “the physical” by way of François Laruelle’s non-philosophical method. Unlike posthumanism, inspired by critical theory and the method of poststructuralism, the theory of the non-human, as a radical dyad of technology in the generic sense of the word (ranging from the techné of speaking a natural language to AI technology) and the organic understood as physicality, does away with anthropocentrism. Moreover, it does away with any anthropomorphology of thought, that is, it does away with any theorizing or philosophy that is centered on the notion of (human) subjectivity or, to borrow a Laruellian term, any “posture of thought” that is molded according to the structure of subjectivity centered thinking,
UNwilling or UNable? The United Nations and the recurrent problem of sexual abuse
Authors: Egelström Sandra
Published: April 2021

AbstractSince its establishment in 1945, the United Nations has grown to become a powerful intergovernmental body enjoying respect and legitimacy among a large part of the international community. Unfortunately, since the 1990s there have been recurrent problems with the organization’s peacekeeping forces being accused of sexual violence against the very people they are supposed to protect. In this article, the UN’s management of events in the Central African Republic (CAR) in 2014 and its inability to put an end to the sexual assaults committed by its representatives have been used to explore whether the organization could be accused of a state crime – under the presumption that the UN can be equated with a state. To do this, the definition of state crime and the complicity continuum developed by Kauzlarich, Mullins and Matthews (2003) are used to evaluate the UN’s actions in relation to the events in the CAR. The responsibilities of the UN in situations like the one in the CAR are examined and discussed.AbstractFörenta nationerna har sedan starten 1945 utvecklats till en mäktig mellanstatlig organisation som åtnjuter respekt och legitimitet från majoriteten av det internationella samfundet. Dessvärre har det, sedan 1990-talet, vid upprepade tillfällen uppdagats att organisationens fredsbevarande styrkor anklagats för sexuellt våld mot just de grupper som de är satta att beskydda. I denna artikel användes organisationens hantering av händelserna i Centralafrikanska republiken (CAR) under 2014, samt dess oförmåga att stoppa sexuella övergrepp utförda av dess företrädare, för att undersöka om FN kunde anklagas för en statligt brott, under förutsättning att organisationen kan likställas med en stat. För detta användes Kauzlarich, Mullins och Matthews (2003) definition av statlig brottslighet, samt det complicity continuum som de utvecklat, för att utvärdera FN:s åtgärder under händelserna i CAR. FN:s ansvar i situationer som det i CAR problematiseras och diskuteras.
Immigration et francophonies minoritaires canadiennes : les apories de la cohésion sociale
Authors: Sall Leyla , Veronis Luisa , Huot Suzanne , Piquemal Nathalie , Zellama Faïçal
Published: April 2021

Les communautés francophones en situation minoritaire (CFSM) du Canada ont opéré une transformation sociétale remarquable au début des années 2000 : elles sont devenues des communautés d’accueil d’immigrants d’expression française et francophiles. Mais qu’en est-il de leur cohésion sociale dans le contexte de la diversité ethnoraciale ? Cet article explore les apories de la cohésion sociale dans quatre CFSM à travers le pays (Colombie-Britannique, Manitoba, Ontario et Nouveau-Brunswick). Il se base, d’une part, sur des tendances lourdes de la recherche en sciences sociales portant sur la cohésion sociale et, d’autre part, sur des données qualitatives issues de groupes de discussion. Nos résultats confirment un fait mis en évidence par la sociologie durkheimienne : l’atteinte d’une cohésion sociale par les CFSM semble devoir passer par un processus de destruction créatrice générateur de collectivités contractuelles, qui sont aptes à intégrer pleinement des immigrants francophones transnationaux qui ne partagent pas nécessairement les ambitions de faire société de leur communauté d’accueil.
Sobre alguns participis actius amb verbs de moviment
Authors: Crespí Isabel
Published: April 2021

L’objectiu d’aquest estudi és analitzar les estructures formades a partir de la combinació d’un participi amb un verb de moviment, en casos com venir plorat de casa. L’interès d’aquestes dades rau en el fet que els participis que descrivim no són actius (plorat, tossit), però adquireixen una lectura activa en combinar-se amb verbs de desplaçament (venir, sortir, arribar). Al llarg de l’article recopilem i descrivim les dades que segueixen aquesta configuració i mirem d’esbossar alguns apunts per a una possible anàlisi formal. D’una banda, seguint la proposta d’Armstrong (2017), defensem que verbs com plorar o tossir permeten la formació d’un participi actiu resultatiu perquè tenen un objecte implícit. Considerem que aquest participi actiu és un predicatiu secundari obligatori seleccionat pel verb principal. Concretament, el participi projecta una oració reduïda que és una clàusula absoluta, per la qual cosa denota un acció finalitzada i anterior a la del verb principal. D’altra banda, proposem que el verb principal és un verb de moviment que projecta una estructura inergativa, i no inacusativa, la qual cosa implica una interpretació agentiva del subjecte.
Història i trama: els casos clínics com a relats acadèmics
Authors: Kot’átková Adéla
Published: April 2021

Els casos clínics constitueixen un gènere propi dels professionals sanitaris, que els redacten i publiquen amb propòsits didàctics i de recerca. A diferència d’altres textos científics, es basen en l’experiència clínica d’un o pocs pacients, per la qual cosa adopten un caràcter narratiu i una sèrie de característiques que ens condueixen a considerar-los com a relats acadèmics. En aquest article mirem d’esbrinar si aquesta consideració és apropiada. Revisem la teoria de la narració per identificar l’element clau que defineix el relat respecte d’altres textos narratius: la trama o intriga. Comprovem la presència d’aquest element en un corpus de casos clínics escrits en català, anglès i castellà publicats en revistes de l’àmbit de la salut mental.
Humanisme o humanitarisme? Fallida d’imponderables a l’entorn d’una discussió propedèutica entre Ramon Esquerra i Manuel Cruells
Authors: Molla Guillem
Published: April 2021

Aquest article analitza l’intercanvi de parers entre els crítics Ramon Esquerra (1909-1938) i Manuel Cruells (1910-1988) sobre com calia entendre l’humanisme renaixentista. Partint d’aquí, se centra en el primer autor per examinar les implicacions derivades de l’acte de pensar la crisi d’entreguerres, la funció de l’intel·lectual i els processos culturals del passat des del context geogràfic i temporal del present. A la llum dels discursos d’alguns dels grans pensadors europeus del moment (Hazard, Berdiàiev, Benda, Maurois, etc.), Esquerra projecta des de la seva crítica literària una preocupació per l’esdevenidor de la civilització occidental davant l’ascens de les ideologies totalitaristes dels anys trenta, fent prevaldre un punt de vista històric i moral molt crític amb el pensament materialista. En aquest sentit, s’analitzen també aspectes com l’herència del cristianisme medieval en la formació d’una suposada consciència europea i el tractament a la premsa del concepte d’humanitarisme a l’entorn del 1935.
Identifying Families in C-SPAN's U.S. Presidential Ratings: 2000, 2009, and 2017
Authors: CRAMER ALEXANDER , CRAMER KENNETH
Published: April 2021

Since the inauguration of George Washington in 1789, the United States of America has seen the governance of some 44 individual presidents. Although such presidents share a variety of attributes, they still differ from one another on many others. Significantly, these traits may be used to construct distinct sets of “families” of presidents throughout American history. By comparatively analyzing data from experts on the U.S. presidency – in this case, the C-SPAN Presidential Historians Surveys from 2000, 2009, and 2017 – this article identifies a consistent set of six presidential families: the All Stars; the Conservative Visionaries; the Postwar Progressives; the Average Joes; the Forgettables; and the Regrettables. In situating these categories in history, this article argues that U.S. presidents can be accurately organized into cohesive, like-performing families whose constituents share a common set of criteria.
The Effect of Sucrose and Stress on Male Participants' Memory
Authors: FOX COSETTE , PAJOR SABRINA
Published: April 2021

Glucose has been shown to have a memory facilitating effect. The goal of this study is to test if sucrose, a carbohydrate consumed on a daily basis, would also enhance memory in male college students. Subjects were given either a sucrose (50 g) or a placebo drink (50.6 mg of saccharine). Subjects filled the Stress Indicator Questionnaire that measures five stress indicators: physical, sleep, behavioral, emotional, and personal habits. A slideshow of 52 IAPS pictures were then shown to the subjects followed by immediate and delayed recall tests and a recognition test. Even though we found no direct effect of sucrose on memory, the results showed that high fasting blood glucose level is associated with lower recognition memory. Furthermore, high sleep stress enhanced memory for immediate recall. On the other hand, high behavioral stress was detrimental for delayed recall and recognition. The differential effects of the different indicators of stress on memory is discussed in relation to changes in cortisol levels that may result in modulation of blood glucose levels which in turn can affect memory. The results of this study shed light on the effect of different types of stress and fasting glucose levels on memory.
Counterfeiting and Michigan: The Territorial and Early Statehood Years
Authors: BAILEY CHRISTOPHER , WHITE NANCY J.
Published: April 2021

Counterfeiting crime was pervasive in the early years of Michigan. This paper describes and analyzes the environment of currency counterfeiting and the causes and effects of counterfeiting in Michigan in the early- and mid-nineteenth century. The laws and changes to the laws of Michigan relating to counterfeiting are also summarized. This is the first state-level historical narrative of nineteenth century counterfeiting in the United States, allowing us to investigate the economic environment and the counterfeiting and counterfeiting law outcomes of a particular state with its particular circumstances. This will give future researchers a basis for state-to-state comparisons of causes and outcomes of counterfeiting and counterfeiting law. In our conclusion, we provide a lengthy example list of future state-to-state counterfeiting comparisons that can be made.
Defects in translation-dependent quality control pathways lead to convergent molecular and neurodevelopmental pathology
Authors: Terrey Markus , Adamson Scott I , Chuang Jeffrey H , Ackerman Susan L
Published: April 2021

Translation-dependent quality control pathways such as no-go decay (NGD), non-stop decay (NSD), and nonsense-mediated decay (NMD) govern protein synthesis and proteostasis by resolving non-translating ribosomes and preventing the production of potentially toxic peptides derived from faulty and aberrant mRNAs. However, how translation is altered and the in vivo defects that arise in the absence of these pathways are poorly understood. Here, we show that the NGD/NSD factorsPeloandHbs1lare critical in mice for cerebellar neurogenesis but expendable for survival of these neurons after development. Analysis of mutant mouse embryonic fibroblasts revealed translational pauses, alteration of signaling pathways, and translational reprogramming. Similar effects on signaling pathways, including mTOR activation, the translatome and mouse cerebellar development were observed upon deletion of the NMD factorUpf2. Our data reveal that these quality control pathways that function to mitigate errors at distinct steps in translation can evoke similar cellular responses.
Local Broadcast Journalists and the Trap of Professional Heterogeneity
Authors: Casula Clementina
Published: April 2021

The ideological tenets of the journalistic professions, historically grounded in the development of modern Western democracies, are increasingly shaken by the changes brought about by a series of technological, economic, and ideological processes challenging the foundations of professionalism. This article considers how these changes influence how work is performed and experienced in Italy by local journalists, providing professional news coverage and programs to communities at the grassroots level through both private and public outlets. The findings of qualitative research adopting a neo-institutional approach are presented and discussed following the analytical frame of the special issue, distinguishing three dimensions (within, between, beyond) related to the increased differentiation and the changing role of professionals in post-industrial societies. Conclusions point to the fact that the resulting heterogeneity if accepted without granting the necessary conditions to maintain professional standards, may bring into question the feasibility of a professional community.
Non-target screening of organic compounds in offshore produced water by GC×GC-MS
Authors: Bergfors Sofie N. , Huynh Khoa , Jensen Annette E. , Sundberg Jonas
Published: April 2021

Produced water is the largest by-product of oil and gas production. At off-shore installations, the produced water is typically reinjected or discharged into the sea. The water contains a complex mixture of dispersed and dissolved oil, solids and inorganic ions. A better understanding of its composition is fundamental to (1) improve environmental impact assessment tools and (2) develop more efficient water treatment technologies. The objective of the study was to screen produced water sampled from a producing field in the Danish region of the North Sea to identify any containing organic compounds. The samples were taken at a test separator and represent an unfiltered picture of the composition before cleaning procedures. The analytes were isolated by liquid-liquid extraction and derivatized using a silylation reagent to increase the volatility of oxygenated compounds. The final extracts were analyzed by comprehensive multi-dimensional gas chromatography coupled to a high-resolution mass spectrometer. A non-target processing workflow was implemented to extract features and quantify the confidence of library matches by correlation to retention indices and the presence of molecular ions. Approximately 120 unique compounds were identified across nine samples. Of those, 15 were present in all samples. The main types of compounds are aliphatic and aromatic carboxylic acids with a small fraction of hydrocarbons. The findings have implications for developing improved environmental impact assessment tools and water remediation technologies.
Compacting oblivious agents on dynamic rings
Authors: Das Shantanu , Di Luna Giuseppe Antonio , Mazzei Daniele , Prencipe Giuseppe
Published: April 2021

In this paper we investigate dynamic networks populated by autonomous mobile agents. Dynamic networks are networks whose topology can change continuously, at unpredictable locations and at unpredictable times. These changes are not considered to be faults, but rather an integral part of the nature of the system. The agents can autonomously move on the network, with the goal of solving cooperatively an assigned common task. Here, we focus on a specific network: the unoriented ring. More specifically, we study 1-interval connected dynamic rings (i.e., at any time, at most one of the edges might be missing). The agents move according to the widely used Look–Compute–Move life cycle, and can be homogenous (thus identical) or heterogenous (agents are assigned colors from a set of c > 1 colors). For identical agents, their goal is to form a compact segment, where agents occupy a continuous part of the ring and no two agents occupy the same node: we call this the Compact Configuration Problem. In the case of agents with colors, called the Colored Compact Configuration Problem, the goal is to group agents such that each group is formed by all agents having the same color, it occupies a continuous segment of the network, and groups of agents having different colors occupy distinct areas of the network. In this paper we determine the necessary conditions to solve both proposed problems. For all solvable cases, we provide algorithms for both the monochromatic and the colored version of the compact configuration problem. All our algorithms work even for the simplest model where agents have no persistent memory, no communication capabilities and do not agree on a common orientation within the network. To the best of our knowledge this is the first work on the compaction problem in a dynamic network.
Evolutionary genomics of endangered Hawaiian tree snails (Achatinellidae: Achatinellinae) for conservation of adaptive capacity
Authors: Price Melissa R. , Hadfield Michael G. , Knapp Ingrid S.S. , Toonen Robert J. , Forsman Zac H.
Published: April 2021

Phylogenomic studies can provide insights into speciation, adaptation, and extinction, while providing a roadmap for conservation. Hawaiian tree snails are a model system for an adaptive radiation facing an extinction crisis. In the last 5 years, nearly all populations of Hawaiian tree snails across the 30 remaining species in the subfamily Achatinellinae (Achatinellidae) have declined from hundreds or thousands in the wild down to undetectable levels. Nearly 100 species historically occurred across dramatic environmental gradients on five of the Hawaiian Islands, but habitat loss, overcollection, and predation by invasive species have decimated populations. As such, this system offers the opportunity to integrate efforts to conserve evolutionary potential into conservation planning for a rapidly declining subfamily. Here, we used genome-wide, restriction-site associated DNA sequencing (RADseq), along with mitochondrial genome reconstruction, to resolve evolutionary relationships to inform conservation efforts. Phylogenetic analysis of nearly 400k genome-wide SNPs from 59 populations and 25 species across six genera in the family Achatinellidae, was generally concordant with taxonomy, geography, and mtDNA with several notable exceptions; mtDNA was unable to resolve some deeper nodes (e.g., the monophyly of Achatinella), while SNP data did not resolve as many shallow nodes. Both phylogenetic and coalescent analysis revealed deep divergences between populations within Achatinella mustelina that were consistent with species-level differences. Given cryptic species-level divergence within populations that are geographically proximate, they are at higher risk of extirpation from invasive predators and climate change than previously assumed. This study clarifies evolutionary relationships within this model system for adaptive radiation, forming the basis for conservation strategies such as translocation, captive rearing, and hybridization trials to prevent the loss of capacity to adapt to rapidly changing environmental conditions.
Bloom evenness modulates the influence of bloom abundance on insect community structure in suburban gardens
Authors: Braatz Elizabeth Y. , Gezon Zachariah J. , Rossetti Kristin , Maynard Lily T. , Bremer Jonathan S. , Hill Geena M. , Streifel Marissa A. , Daniels Jaret C.
Published: April 2021

As land use change drives global insect declines, the value of enhancing habitat in urban and suburban landscapes has become increasingly important for flower-visiting insects. In order to help identify best landscaping practices, we conducted plant surveys and insect bowl-trap surveys in 34 suburban yards for 21 months in Gainesville, FL, USA, which resulted in 274 paired days of plant and insect survey data. We assessed the impact of nearest greenspace size, distance to greenspace, yard area, plant richness, plant type, bloom abundance, bloom richness and bloom evenness on insect abundance and richness. Our samples include 34,972 insects captured, 485,827 blooms counted and 774 species of plants recorded. We found that bloom evenness had a modulating effect on bloom abundance—a more even sample of the same number of blooms would have a disproportionately greater positive impact on flower visitor richness, insect richness and insect abundance. Bloom abundance was also highly significant and positively associated with flower visitor abundance, but nearest greenspace size, distance to greenspace, plant type (native vs. non-native vs. Florida Friendly), and yard area were not found to be important factors. Plant richness was a highly significant factor, but its effect size was very small.
Soil microbial diversity in organic and non-organic pasture systems
Authors: Acharya Mohan , Ashworth Amanda J. , Yang Yichao , Burke Joan M. , Lee Jung Ae , Sharma Acharya Roshani
Published: April 2021

Understanding the effects of organic pasture management on the soil microbiome is important for sustainable forage production since soil microbiome diversity contributes to improved nutrient cycling, soil structure, plant growth, and environmental resiliency; however, the soil microbiome response to pasture management is largely unknown. This study assessed the soil microbial diversity, richness, and community structure following 10 years of pasture management (organic or non-organic) of the V4 region of the 16S rRNA using the Illumina MiSeq platform. Soil samples were collected from 0–15 cm in July and August from 2017–2018 and soil nutrient properties (nutrients, carbon, nitrogen, and pH) quantified and correlated with soil microbial diversity. Overall, greater soil bacterial species richness (P ≤ 0.05) occurred in organic relative to non-organic (conventional) systems. Management affected bacterial species richness (Chao1), with greater richness occurring in organic pasture soils and less richness occurring in non-organic systems (P ≤ 0.05). Similarly, management affected bacterial evenness (Simpson’s index), with a more diverse community occurring in organically managed soils relative to non-organic pastures (P ≤ 0.05). Linear discriminant analysis effect size analysis showed statistically significant and biologically consistent differences in bacterial taxa in organic compared with non-organic soils. Therefore, there was a shift in bacterial community structure in organic relative to non-organic soils (P ≤ 0.05). Additionally, soil nutrients (Fe, Mg, Ni, S, Al, K, Cd, and Cu), pH, C, and N were correlated with one or more dominant bacterial phyla (Gemmatimonadetes, Planctomycetes, Firmicutes, Chloroflexi, Actinobacteria, and Acidobacteria). Overall, pasture management affected soil microbial diversity, with greater diversity occurring in organic than non-organic systems, likely owing to applications of organic poultry litter in organic systems compared to non-organic management (use of inorganic-fertilizers and herbicides). Results indicate that when pastures are converted to organic production systems, soil microbial richness and diversity may increase, thereby resulting in enhanced soil microbiome diversity and overall ecosystem services.
The antimicrobial activity of silver acetate against Acinetobacter baumannii in a Galleria mellonella infection model
Authors: Mannix-Fisher Eden , McLean Samantha
Published: April 2021

Background

The increasing prevalence of bacterial infections that are resistant to antibiotic treatment has caused the scientific and medical communities to look for alternate remedies aimed at prevention and treatment. In addition to researching novel antimicrobials, there has also been much interest in revisiting some of the earliest therapies used by man. One such antimicrobial is silver; its use stretches back to the ancient Greeks but interest in its medicinal properties has increased in recent years due to the rise in antibiotic resistance. Currently antimicrobial silver is found in everything from lunch boxes to medical device implants. Though much is claimed about the antimicrobial efficacy of silver salts the research in this area is mixed.

Methods

Herein we investigated the efficacy of silver acetate against a carbapenem resistant strain of Acinetobacter baumannii to determine the in vitro activity of this silver salt against a World Health Organisation designated category I critical pathogen. Furthermore, we use the Galleria mellonella larvae model to assess toxicity of the compound and its efficacy in treating infections in a live host.

Results

We found that silver acetate can be delivered safely to Galleria at medically relevant and antimicrobial levels without detriment to the larvae and that administration of silver acetate to an infection model significantly improved survival. This demonstrates the selective toxicity of silver acetate for bacterial pathogens but also highlights the need for administration of well-defined doses of the antimicrobial to provide an efficacious treatment.
Bayes Estimators of Exponentiated Inverse Rayleigh Distribution using Lindleys Approximation
Authors: Sule Bashiru Omeiza , Adegoke Taiwo Mobolaji , Uthman Kafayat Tolani
Published: April 2021

In this paper, Bayes estimators of the unknown shape and scale parameters of the Exponentiated Inverse Rayleigh Distribution (EIRD) have been derived using both the frequentist and bayesian methods. The Bayes theorem was adopted to obtain the posterior distribution of the shape and scale parameters of an Exponentiated Inverse Rayleigh Distribution (EIRD) using both conjugate and non-conjugate prior distribution under different loss functions (such as Entropy Loss Function, Linex Loss Function and Scale Invariant Squared Error Loss Function). The posterior distribution derived for both shape and scale parameters are intractable and a Lindley approximation was adopted to obtain the parameters of interest. The loss function were employed to obtain the estimates for both scale and shape parameters with an assumption that the both scale and shape parameters are unknown and independent. Also the Bayes estimate for the simulated datasets and real life datasets were obtained. The Bayes estimates obtained under dierent loss functions are close to the true parameter value of the shape and scale parameters. The estimators are then compared in terms of their Mean Square Error (MSE) using R programming language. We deduce that the MSE reduces as the sample size (n) increases.
An adaptive feedback linearized model predictive controller design for a nonlinear multi‐input multi‐output system
Authors: Dutta Lakshmi , Das Dushmanta K.
Published: April 2021

In this work, an adaptive feedback linearized model predictive control (AFLMPC) scheme is proposed to compensate system uncertainty for a class of nonlinear multi‐input multi‐output system. Initially, a feedback linearization technique is used to transform the nonlinear dynamics into an exact linear model, thereafter, a model predictive control scheme is designed to obtain the desired tracking performance. A suitable constraint mapping algorithm has been developed to map input constraints to the new virtual input of the proposed control scheme. The proposed control scheme utilizes multiple estimation model and the concept of second‐level adaptation technique Pandey et al. (2014) to handle the parametric uncertainty in real‐time. Hence, the adaptive term in the control scheme is used to counteract the effect of model uncertainties and parameter adaptation errors. The effectiveness of the proposed AFLMPC control algorithm has been verified successfully in simulation as well as the experimental setup of the TRMS model. The unavailable states of the nonlinear system have been estimated using an extended Kalman filter based state observer. The performance of the proposed control algorithm has been compared with other existing nonlinear control techniques in simulation and experimental validation.
Conformal, Ultra‐thin Skin‐Contact‐Actuated Hybrid Piezo/Triboelectric Wearable Sensor Based on AlN and Parylene‐Encapsulated Elastomeric Blend
Authors: Mariello Massimo , Fachechi Luca , Guido Francesco , De Vittorio Massimo
Published: April 2021

Flexible electronics based on piezoelectric/triboelectric devices is an attractive technology for human sensing. Their hybridization overcomes the limitations of single components, resulting in compliant skin sensors with enhanced performances and applicability. Such hybrid devices are typically based on wide‐area scarcely durable polymers or lead‐containing piezoelectric materials; they are often not biocompatible and poorly skin‐adaptable, lacking in multifunctionality. In this work, a novel compliant, conformal hybrid piezoelectric‐triboelectric ultra‐thin wearable sensor made of biocompatible materials is reported. The device is in contact with skin through an ultra‐soft patch covered on both sides by a thin friction parylene film. Its working principle is unprecedently based on three simultaneous, complementary and mutually enhancing effects: piezoelectric, skin‐contact‐actuation, and piezo‐tribo hybrid contact. The device can detect, with high sensitivity and wide measurement range, both the impulsiveness of sudden motions and the slower micro‐friction phenomena due to skin deformations, ensuring a stable and repeatable identification of bio‐signals typical of body movements. The device multifunctionality is shown for identifying gait walking, distinguishing hand gestures with a 5‐sensor system on the hand back, and monitoring human joints motions (neck, wrist, elbow, knee, ankle). The assessed energy harvesting capabilities demonstrate the suitability for fabrication of more complex self‐powered sensing systems.
Ultrathin Layered Double Hydroxide Nanosheets Enabling Composite Polymer Electrolyte for All‐Solid‐State Lithium Batteries at Room Temperature
Authors: Xia Shuixin , Yang Binbin , Zhang Hebin , Yang Junhe , Liu Wei , Zheng Shiyou
Published: April 2021

Solid electrolytes are the most promising substitutes for liquid electrolytes to construct high‐safety and high‐energy‐density energy storage devices. Nevertheless, the poor lithium ion mobility and ionic conductivity at room temperature (RT) have seriously hindered their practical usage. Herein, single‐layer layered‐double‐hydroxide nanosheets (SLN) reinforced poly(vinylidene fluoride‐co‐hexafluoropropylene) (PVDF‐HFP) composite polymer electrolyte is designed, which delivers an exceptionally high ionic conductivity of 2.2 × 10−4 S cm−1 (25 °C), superior Li+ transfer number (≈0.78) and wide electrochemical window (≈4.9 V) with a low SLN loading (≈1 wt%). The Li symmetric cells demonstrate ultra‐long lifespan stable cycling over ≈900 h at 0.1 mA cm−2, RT. Moreover, the all‐solid‐state Li|LiFePO4 cells can run stably with a high capacity retention of 98.6% over 190 cycles at 0.1 C, RT. Moreover, using LiCoO2/LiNi0.8Co0.1Mn0.1O2, the all‐solid‐state lithium metal batteries also demonstrate excellent cycling at RT. Density functional theory calculations are performed to elucidate the working mechanism of SLN in the polymer matrix. This is the first report of all‐solid‐state lithium batteries working at RT with PVDF‐HFP based solid electrolyte, providing a novel strategy and significant step toward cost‐effective and scalable solid electrolytes for practical usage at RT.
2D Gadolinium Oxide Nanoplates as T1 Magnetic Resonance Imaging Contrast Agents
Authors: Stinnett Gary , Taheri Nasim , Villanova Jake , Bohloul Arash , Guo Xiaoting , Esposito Edward P. , Xiao Zhen , Stueber Deanna , Avendano Carolina , Decuzzi Paolo , Pautler Robia G. , Colvin Vicki L.
Published: April 2021

Millions of people a year receive magnetic resonance imaging (MRI) contrast agents for the diagnosis of conditions as diverse as fatty liver disease and cancer. Gadolinium chelates, which provide preferred T1 contrast, are the current standard but face an uncertain future due to increasing concerns about their nephrogenic toxicity as well as poor performance in high‐field MRI scanners. Gadolinium‐containing nanocrystals are interesting alternatives as they bypass the kidneys and can offer the possibility of both intracellular accumulation and active targeting. Nanocrystal contrast performance is notably limited, however, as their organic coatings block water from close interactions with surface Gadoliniums. Here, these steric barriers to water exchange are minimized through shape engineering of plate‐like nanocrystals that possess accessible Gadoliniums at their edges. Sulfonated surface polymers promote second‐sphere relaxation processes that contribute remarkable contrast even at the highest fields (r1 = 32.6 × 10−3 m Gd−1 s−1 at 9.4 T). These noncytotoxic materials release no detectable free Gadolinium even under mild acidic conditions. They preferentially accumulate in the liver of mice with a circulation half‐life 50% longer than commercial agents. These features allow these T1 MRI contrast agents to be applied for the first time to the ex vivo detection of nonalcoholic fatty liver disease in mice.
Simultaneous Delivery of Multiple Antimicrobial Agents by Biphasic Scaffolds for Effective Treatment of Wound Biofilms
Authors: Su Yajuan , McCarthy Alec , Wong Shannon L. , Hollins Ronald R. , Wang Guangshun , Xie Jingwei
Published: April 2021

Biofilms pose a major challenge to control wound‐associated infections. Due to biofilm impenetrability, traditional antimicrobial agents are often ineffective in combating biofilms. Herein, a biphasic scaffold is reported as an antimicrobial delivery system by integrating nanofiber mats with dissolvable microneedle arrays for the effective treatment of bacterial biofilms. Different combinations of antimicrobial agents, including AgNO3, Ga(NO3)3, and vancomycin, are incorporated into nanofiber mats by coaxial electrospinning, which enables sustained delivery of these drugs. The antimicrobial agents‐incorporated dissolvable microneedle arrays allow direct penetration of drugs into biofilms. By optimizing the administration strategies, drug combinations, and microneedle densities, biphasic scaffolds are able to eradicate both methicillin‐resistant Staphylococcus aureus (MRSA) and MRSA/Pseudomonas aeruginosa blend biofilms in an ex vivo human skin wound infection model without necessitating surgical debridement. Taken together, the combinatorial system comprises of nanofiber mats and microneedle arrays can provide an efficacious delivery of multiple antimicrobial agents for the treatment of bacterial biofilms in wounds.
Capillary‐Force‐Driven Self‐Assembly of 4D‐Printed Microstructures
Authors: Liu Xiaojiang , Wei Mengxiao , Wang Qiong , Tian Yujia , Han Jiamian , Gu Hongcheng , Ding Haibo , Chen Qiang , Zhou Kun , Gu Zhongze
Published: April 2021

Capillary‐force‐driven self‐assembly is emerging as a significant approach for the massive manufacture of advanced materials with novel wetting, adhesion, optical, mechanical, or electrical properties. However, academic value and practical applications of the self‐assembly are greatly restricted because traditional micropillar self‐assembly is always unidirectional. In this work, two‐photon‐lithography‐based 4D microprinting is introduced to realize the reversible and bidirectional self‐assembly of microstructures. With asymmetric crosslinking densities, the printed vertical microstructures can switch to a curved state with controlled thickness, curvature, and smooth morphology that are impossible to replicate by traditional 3D‐printing technology. In different evaporating solvents, the 4D‐printed microstructures can experience three states: (I) coalesce into clusters from original vertical states via traditional self‐assembly, (II) remain curved, or (III) arbitrarily self‐assemble (4D self‐assembly) toward the curving directions. Compared to conventional approaches, this 4D self‐assembly is distance‐independent, which can generate varieties of assemblies with a yield as high as 100%. More importantly, the three states can be reversibly switched, allowing the development of many promising applications such as reversible micropatterns, switchable wetting, and dynamic actuation of microrobots, origami, and encapsulation.
Optical and Structural Properties of Manganese‐Doped Zinc Oxide Grown by Metal‐Organic Chemical Vapor Deposition
Authors: Saravade Vishal , Manzoor Zahra , Corda Alexis , Zhou Chuanle , Ferguson Ian , Lu Na
Published: April 2021

This systematic study investigates the optical properties and process−structure−property relationships of Mn‐doped zinc oxide (ZnMnO) grown by metal‐organic chemical vapor deposition with varying Mn‐doping concentration and growth conditions. ZnMnO exhibits a good crystal quality oriented in the (002) direction and contains intermixtures of zinc oxide (ZnO)‐like and manganese oxide (MnxOy)‐like phases. The material exhibits a direct energy absorption band‐edge and a reduction in bandgap with Mn‐doping. Photoluminescence studies show that Mn‐doping can simultaneously tailor broad green band luminescence and ultraviolet edge emissions. Post‐growth air‐annealing results in broad MnxOy‐related photoluminescence emissions at 3.3–4.5 eV. A further reduction in the absorption band‐edge is also observed with annealing. Results indicate that luminescence wavelengths and intensities, and absorption band‐edge can be tuned with the Mn‐doping process. This paper promotes a thorough understanding of defect centers in ZnO with transition metal doping and their interrelation with optical characteristics. The work provides a solid foundation for the development of optoelectronic devices, such as light emitting diodes, solar cells, lasers, and photodetectors using ZnO‐based materials.
A New Monolayer B4C4 with Robust Stability and Excellent Performance for Spontaneous Water Splitting Under Visible Light
Authors: Li Lin , Li Xiaowei , Zhang Qiuyu , Zhu Dongyang , Li Xiaoyu , Zhang Yihe
Published: April 2021

The nature of new monolayer boron carbides (B4C4) and their photocatalytic performance for spontaneous water splitting are investigated using first‐principles calculations. It is interesting to find that B4C4 has a special puckered surface similar to pure borophene and exhibits robust mechanical stability even at extremely high temperature in the molecular dynamics simulation. Its elastic constant in a direction is close to the superstar graphene in 2D materials. Moreover, B4C4 also meets two necessary principles as a photocatalyst, it has proper valence and conduction band positions and a proper indirect bandgap. The optical absorption edge is about 525 nm corresponding a larger range of visible light adsorption than that of g‐C3N4. Additionally, the carrier mobilities are estimated to be about 800 cm2 V−1 s−1 of the electron and 40 000 cm2 V−1 s−1 of the hole which shows its excellent photocatalytic performance. Further calculations demonstrate that the H2O molecule can be stably adsorbed on B4C4 sheet, only a smaller activation energy is needed and the water splitting can be carried out spontaneously. The nanoribbon structures still maintain good performances for practical applications. Generally speaking, the new monolayer B4C4 is an efficient and promising photocatalyst toward overall water splitting proved by these calculation results.
Absolute Volume Deformation Potentials of Inorganic ABX3 Halide Perovskites: The Chemical Trends
Authors: Wang Shanshan , Huang Menglin , Wu Yu‐Ning , Chen Shiyou
Published: April 2021

The absolute volume deformation potential (AVDP) is an important physical quantity that describes the absolute energy level shift of semiconductors under pressure. The valence band maximum (VBM) and conduction band minimum (CBM) AVDPs of inorganic cubic ABX3 perovskites (where A = K, Rb, Cs; B = Ge, Sn, Pb; X = Cl, Br, I) are systematically investigated using ab‐initio simulations. Spin‐orbit coupling (SOC) is found to have negligible effect on the AVDPs of ABX3 perovskites, though it plays an important role in their band structures. The AVDPs of VBM are determined to be all negative and large, meaning the energy level will shift downward as the crystal volumes increase, while AVDPs of CBM are mostly positive and small. The AVDPs of VBM and CBM both increase as the atomic number of X‐site element increases, while the absolute value of VBM's AVDP increases initially and decreases afterward as atomic number of B‐site element becomes larger. These trends can be well explained based on the atomic orbital levels, the hybridization of the band edge orbitals, bond length, and bandwidth. These results provide critical parameters for the band structure engineering design of optoelectronic devices based on the ABX3 halide perovskites through strain control.