bluuebunny/crossref_metadata_2025 huggingface dataset:
Exact Tile-Based Segmentation Inference for Images Larger than GPU
Memory
Authors: Majurski Michael , Bajcsy Peter
Published: June 2021

We address the problem of performing exact (tiling-error free) out-of-core semantic segmentation inference of arbitrarily large images using fully convolutional neural networks (FCN). FCN models have the property that once a model is trained, it can be applied on arbitrarily sized images, although it is still constrained by the available GPU memory. This work is motivated by overcoming the GPU memory size constraint without numerically impacting the fnal result. Our approach is to select a tile size that will ft into GPU memory with a halo border of half the network receptive feld. Next, stride across the image by that tile size without the halo. The input tile halos will overlap, while the output tiles join exactly at the seams. Such an approach enables inference to be performed on whole slide microscopy images, such as those generated by a slide scanner. The novelty of this work is in documenting the formulas for determining tile size and stride and then validating them on U-Net and FC-DenseNet architectures. In addition, we quantify the errors due to tiling confgurations which do not satisfy the constraints, and we explore the use of architecture effective receptive felds to estimate the tiling parameters.
Emergence de dispositifs de GRH partagés entre PME dans des clusters : enseignements à partir de six cas en France
Authors: Calamel Ludivine , Sanséau Pierre-Yves
Published: June 2021

Cet article a pour objectif d’analyser l’émergence et la nature de dispositifs et de pratiques de gestion de ressources humaines (GRH) partagés par des PME, au sein de réseaux territoriaux d’organisations de type cluster. En mobilisant la méthode de l’étude multi-cas, l’analyse de six clusters en France a permis d’identifier des dispositifs de GRH partagés par des PME de trois natures (avortés, en projet, mis en oeuvre) et caractérisés par quatre types de pratiques de GRH (communication, formation, recrutement et gestion des compétences). L’analyse de ces dispositifs et de ces pratiques par l’approche des proximités souligne l’importance de la proximité géographique, associée à celles de la proximité socio-économique des ressources ainsi que de coordination, dans l’émergence des dispositifs de GRH dans les clusters. De plus, la place de la confiance liée à la direction du cluster est discutée.
Être petit et réussir à l’export : étude de dix cas d’entreprises vitivinicoles françaises
Authors: Cheriet Foued , Maurel Carole
Published: June 2021

Plusieurs controverses jalonnent les recherches antérieures sur l’exportation des PME. L’objet de notre travail est d’analyser les facteurs de succès et les risques d’échec à l’international de ces entreprises. Pour cela, nous avons mené une analyse empirique sur dix cas d’entreprises vitivinicoles françaises. Nos résultats montrent une forte diversité des trajectoires à l’export et des visions distinctes du succès et de l’échec à l’international. Trois stratégies non exclusives (partenariale, communication, ressources humaines) se dessinent. Loin d’être un handicap, la petite taille des entreprises vitivinicoles peut se traduire par des attributs compétitifs distinctifs (lien au terroir, spécialisation, image-histoire du producteur).
Intermediate, Local and Glocal Innovation Models for MNCs Targeting Emerging Markets: The Case of a European Telco Operator in Africa and the Middle East
Authors: Ben Mahmoud-Jouini Sihem , Charue-Duboc Florence , Hadengue Marine
Published: June 2021

In this article, we highlight an alternate model of innovation for multinational corporations from advanced markets targeting emerging markets. This model, labeled the intermediate model, is characterized by the nature of the targeted markets as well as the development process. We show that, conversely to the glocal and local models, the intermediate model mixes corporate and local resources from the early stage of the innovation process, during the development and, until the deployment and commercialization of the innovation in the successive emerging markets. We address these questions through the case of a French telco operator targeting Africa and the Middle East.
I Want It All and I Want It Now. Motivations of Counterfeit Luxury Consumption Among Gcc Consumers
Authors: Pueschel Julia
Published: June 2021

This research investigates the motivations of counterfeit luxury consumption in the Gulf Cooperation Council (GCC) countries. Using a Means-End Chain approach, this research uncovers four dominant motivational patterns and complexities that drive affluent GCC consumers to purchase counterfeit luxury products: Value-Consciousness, Belonging, Hedonism and Self-esteem. Luxury brands and policy makers could use these main hidden final values to gain a holistic understanding of consumer motivations and develop stronger anti-counterfeiting strategies to discourage counterfeit consumption.
Ambidextrie adaptative et environnement dynamique : étude longitudinale d’une
PME
Authors: Bogaert Jean-Christophe , Mothe Caroline
Published: June 2021

L’effet temporel de l’ambidextrie organisationnelle sur la longévité des
organisations reste peu étudié, en particulier dans un contexte d’environnement
dynamique. Notre recherche longitudinale couvrant les 25 années d'existence d'une
PME dans la biotechnologie industrielle s'appuie sur une combinaison de méthodes
quantitative et qualitative. Les résultats montrent que l’entreprise a su maintenir
de fortes intensités d’exploration et d’exploitation et les adapter aux multiples
changements de son environnement, essentiellement grâce au réseau. Nous montrons
qu’une ambidextrie adaptative peut être maintenue de manière dynamique en combinant
différents types d’ambidextrie par le biais d’une plasticité
organisationnelle.
La Russie : une cyber-puissance ?
Authors: Bertran Marie-Gabrielle
Published: June 2021

Depuis 2013 et les révélations d’Edward Snowden, la problématique de la souveraineté numérique est devenue un enjeu central en Russie. Selon ce nouveau paradigme, le gouvernement russe a lancé une politique de promotion du développement logiciel dans le pays, appuyée par les acteurs privés qui en bénéficient au premier chef. Une stratégie de russification des logiciels employés sur le territoire semble également avoir émergé, sous la forme de nouvelles normes visant à réglementer la conception, le fonctionnement et l’usage des outils informatiques. Ce passage de l’industrie numérique à une position majeure (à valeur stratégique) en Russie, dans le but d’assurer à la fois les intérêts de l’État et des entreprises russes sur le territoire, mais aussi en-dehors, peut ainsi amener à se demander si le pays compte désormais parmi les puissances internationales du numérique : la Russie est-elle devenue une cyber-puissance ?
Le vecteur asiatique : leurre ou atout de la puissance russe ?
Authors: Facon Isabelle
Published: June 2021

D’une manière générale, l’intention affichée depuis plusieurs années par Moscou de rééquilibrer sa diplomatie et ses relations économiques extérieures au profit du « vecteur asiatique » suscite le scepticisme. Dans les pays occidentaux, ce rééquilibrage est fréquemment considéré comme étant essentiellement le produit de la crise des rapports stratégiques entre la Russie et la communauté euro-atlantique après l’annexion de la Crimée en 2014. Experts et chercheurs russes, quant à eux, semblent également perplexes. Cependant, et pour difficile qu’il soit, le « pivot asiatique » de la Russie mérite attention, car il correspond pour ce pays à des enjeux ayant trait à la fois à sa sécurité et à son statut revendiqué de grande puissance. La question est de savoir si la Russie joue au mieux les possibilités ouvertes par un contexte asiatique qui lui est apparemment un peu plus favorable.
Dos mundos conectados: Cómo la exposición al estrés social nos hace más vulnerables al consumo de drogas
Authors: Montagud-Romero Sandra , D. Reguilón Marina , Rodriguez-Arias Marta
Published: June 2021

El estrés es uno de los principales factores de riesgo que pueden inducir al ser humano a desarrollar trastornos como la depresión, la ansiedad o el consumo de drogas. Una de las principales fuentes de estrés es la interacción social, que puede llevar a situaciones como el acoso escolar o laboral. En este artículo revisaremos la estrecha relación que existe entre la exposición a situaciones estresantes y el incremento en el consumo de la cocaína o el alcohol. Expondremos los principales resultados obtenidos con modelos animales ya que nos permiten estudiar los mecanismos cerebrales involucrados en el impacto del estrés sobre el consumo de drogas. Para concluir, detallaremos los principales mecanismos que explicarían el potente efecto que produce el estrés sobre el consumo de drogas.
Las otras dianas del trastorno por uso de alcohol: Afectaciones sistémicas derivadas del consumo excesivo de alcohol
Authors: Sanvisens Arantza , Muga Robert
Published: June 2021

Consumir alcohol es un hecho arraigado y normalizado en nuestra sociedad, aunque ello pueda suponer un daño físico para el individuo. El consumo de riesgo es un patrón de consumo de alcohol que aumenta la probabilidad de padecer consecuencias negativas para el bebedor o para su entorno. El hígado es, por excelencia, el órgano más afectado por el consumo abusivo de alcohol; sin embargo, el trastorno por uso de alcohol es una enfermedad sistémica con afectaciones orgánicas y psíquicas muy variadas. El sistema inmunitario, el neurológico o el cardiovascular son algunos de los que se pueden ver afectados por el consumo continuado de esta sustancia. Además, el alcohol puede ser la causa de alteraciones epigenéticas que pueden transmitirse de una generación a otra.
Adicción al juego: ¿mito o realidad? Evidencias científicas sobre el trastorno de juego
Authors: Mestre-Bach Gemma , Valenciano-Mendoza Eduardo , Mora-Maltas Bernat , Fernández-Aranda Fernando , Jiménez-Murcia Susana
Published: June 2021

El interés por el trastorno de juego, anteriormente conocido como juego patológico y, en nuestro país, como ludopatía, ha sido creciente tanto en la comunidad clínica como científica. El aumento de evidencia empírica referente al trastorno de juego ha permitido una mejor conceptualización de la patología, así como la identificación de comorbilidades frecuentes y el diseño de posibles opciones terapéuticas efectivas. La presente revisión aborda todas estas temáticas, incluyendo hallazgos recientes en el ámbito de estudio en cuestión.
On the assessment of the national poverty threshold
Authors: Kormishkina Ludmila Aleksandrovna , Ermakova Eka Revazievna
Published: June 2021

This article explores the peculiarities of the phenomenon of poverty in the post-Soviet Russia as one of the key social indicators of the achieved level of well-being and sustainable development of the country. The subject of this research is the socioeconomic relations that condition the persistence of large-scale absolute and relative poverty, and excessive social inequality in the country. The goal consists in outlining boundaries of the existing methodology of definition of poverty; as well as in substantiating that the use of modern methods leads to lowering the subsistence line and minimum wage. The author forms the databases necessary for displaying the absolute and relative poverty threshold in Russia and other foreign countries for the period 2000 – 2019. The article also employs Data Mining. The information framework is comprised of the official statistics of Rosstat and Eurostat, usa.gov International Monetary Fund, World Bank, legal reference system ConsultantPlus; annual reports of the Credit Suisse Institute, World Inequality Lab; infographics of the information analytical portal Knoema. In the course of an analytical retrospective assessment of dynamics of the key indicators of poverty threshold in the Russian Federation, the author establishes a significant discrepancy between the official and actual threshold, which distorts the relevant picture of poverty, impedes the development of the effective strategy for overcoming poverty, which imparts chronic character to this phenomenon. Relying on the relevant foreign experience of poverty reduction strategy, as well as scientific and practical works of the Russian experts in this field, the author justifies the measures for eradication of poverty in the Russian Federation. Recommendations are given for amending the state policy on promoting reduction of poverty in modern Russia, taking into account the need to overcome excessive social inequality.
Less Stress, More Satisfied in Online Learning During the COVID-19 Pandemic: The Moderating Role of Academic Resilience
Authors: Kumalasari Dewi , Akmal Sari Zakiah
Published: June 2021

The COVID-19 outbreak triggered a sudden transformation in all aspects of life. Inevitably, educational environments were also affected. Previous studies found a sharp drop in student satisfaction and a simultaneous corresponding increase in academic stress when online learning was instituted due to the pandemic. Conversely, academic resilience is considered psychological capital; it enables students to overcome stress and stimulates satisfaction. The interactions of these three variables must thus be collectively examined. This study used the convenience sampling technique to investigate the moderating role of academic resilience vis-à-vis academic stress and student satisfaction with online learning during the COVID-19 pandemic. Data were collected via an online questionnaire from a sample of 337 Indonesian undergraduate students aged 18‒32 years recruited for this study. The questionnaire encompassed three measurement instruments: Stressor Scale for College Students (α =.85), Academic Resilience Scale-Indonesian version (α =.89), and Student Satisfaction with Online Learning (α =.90). Linear regression analysis revealed that academic stress exerted a significant negative effect on satisfaction with online learning. Academic resilience was a significant moderator, dampening the effects of academic stress on satisfaction with online learning. The theoretical and practical implications of the research results are also discussed.
The critical role of Hedgehog-responsive mesenchymal progenitors in meniscus development and injury repair
Authors: Wei Yulong , Sun Hao , Gui Tao , Yao Lutian , Zhong Leilei , Yu Wei , Heo Su-Jin , Han Lin , Dyment Nathaniel A , Liu Xiaowei Sherry , Zhang Yejia , Koyama Eiki , Long Fanxin , Zgonis Miltiadis H , Mauck Robert L , Ahn Jaimo , Qin Ling
Published: June 2021

Meniscal tears are associated with a high risk of osteoarthritis but currently have no disease-modifying therapies. Using a Gli1 reporter line, we found that Gli1+ cells contribute to the development of meniscus horns from 2 weeks of age. In adult mice, Gli1+ cells resided at the superficial layer of meniscus and expressed known mesenchymal progenitor markers. In culture, meniscal Gli1+ cells possessed high progenitor activities under the control of Hh signal. Meniscus injury at the anterior horn induced a quick expansion of Gli1-lineage cells. Normally, meniscal tissue healed slowly, leading to cartilage degeneration. Ablation of Gli1+ cells further hindered this repair process. Strikingly, intra-articular injection of Gli1+ meniscal cells or an Hh agonist right after injury accelerated the bridging of the interrupted ends and attenuated signs of osteoarthritis. Taken together, our work identified a novel progenitor population in meniscus and proposes a new treatment for repairing injured meniscus and preventing osteoarthritis.
Short and long sleeping mutants reveal links between sleep and macroautophagy
Authors: Bedont Joseph L , Toda Hirofumi , Shi Mi , Park Christine H , Quake Christine , Stein Carly , Kolesnik Anna , Sehgal Amita
Published: June 2021

Sleep is a conserved and essential behavior, but its mechanistic and functional underpinnings remain poorly defined. Through unbiased genetic screening in Drosophila, we discovered a novel short-sleep mutant we named argus. Positional cloning and subsequent complementation, CRISPR/Cas9 knock-out, and RNAi studies identified Argus as a transmembrane protein that acts in adult peptidergic neurons to regulate sleep. argus mutants accumulate undigested Atg8a(+) autophagosomes, and genetic manipulations impeding autophagosome formation suppress argus sleep phenotypes, indicating that autophagosome accumulation drives argus short-sleep. Conversely, a blue cheese neurodegenerative mutant that impairs autophagosome formation was identified independently as a gain-of-sleep mutant, and targeted RNAi screens identified additional genes involved in autophagosome formation whose knockdown increases sleep. Finally, autophagosomes normally accumulate during the daytime and nighttime sleep deprivation extends this accumulation into the following morning, while daytime gaboxadol feeding promotes sleep and reduces autophagosome accumulation at nightfall. In sum, our results paradoxically demonstrate that wakefulness increases and sleep decreases autophagosome levels under unperturbed conditions, yet strong and sustained upregulation of autophagosomes decreases sleep, whereas strong and sustained downregulation of autophagosomes increases sleep. The complex relationship between sleep and autophagy suggested by our findings may have implications for pathological states including chronic sleep disorders and neurodegeneration, as well as for integration of sleep need with other homeostats, such as under conditions of starvation.
Latent gammaherpesvirus exacerbates arthritis through modification of age-associated B cells
Authors: Mouat Isobel C , Morse Zachary J , Shanina Iryna , Brown Kelly L , Horwitz Marc S
Published: June 2021

Epstein-Barr virus (EBV) infection is associated with rheumatoid arthritis (RA) in adults, though the nature of the relationship remains unknown. Herein, we have examined the contribution of viral infection to the severity of arthritis in mice. We have provided the first evidence that latent gammaherpesvirus infection enhances clinical arthritis, modeling EBV’s role in RA. Mice latently infected with a murine analog of EBV, gammaherpesvirus 68 (γHV68), develop more severe collagen-induced arthritis and a Th1-skewed immune profile reminiscent of human disease. We demonstrate that disease enhancement requires viral latency and is not due to active virus stimulation of the immune response. Age-associated B cells (ABCs) are associated with several human autoimmune diseases, including arthritis, though their contribution to disease is not well understood. Using ABC knockout mice, we have provided the first evidence that ABCs are mechanistically required for viral enhancement of disease, thereby establishing that ABCs are impacted by latent gammaherpesvirus infection and provoke arthritis.
Tight nanoscale clustering of Fcγ receptors using DNA origami promotes phagocytosis
Authors: Kern Nadja , Dong Rui , Douglas Shawn M , Vale Ronald D , Morrissey Meghan A
Published: June 2021

Macrophages destroy pathogens and diseased cells through Fcγ receptor (FcγR)-driven phagocytosis of antibody-opsonized targets. Phagocytosis requires activation of multiple FcγRs, but the mechanism controlling the threshold for response is unclear. We developed a DNA origami-based engulfment system that allows precise nanoscale control of the number and spacing of ligands. When the number of ligands remains constant, reducing ligand spacing from 17.5 nm to 7 nm potently enhances engulfment, primarily by increasing efficiency of the engulfment-initiation process. Tighter ligand clustering increases receptor phosphorylation, as well as proximal downstream signals. Increasing the number of signaling domains recruited to a single ligand-receptor complex was not sufficient to recapitulate this effect, indicating that clustering of multiple receptors is required. Our results suggest that macrophages use information about local ligand densities to make critical engulfment decisions, which has implications for the mechanism of antibody-mediated phagocytosis and the design of immunotherapies.
Futuro y condicional en las lenguas iberorromances
Authors: Víctor Lara Bermejo
Published: June 2021

El futuro morfológico y el condicional en las lenguas iberorromances expresan tanto modalidad como temporalidad, pero cada vez más autores señalan que también pueden configurar evidencialidad. Los datos que se manejan a día de hoy proceden de escasos ejemplos o provienen de la introspección del propio investigador. En este artículo pretendemos dar cuenta de la vigencia actual del futuro y el condicional en todo el espectro iberorromance a través de las ocurrencias de una serie de corpus dialectales que reflejan habla oral y espontánea. La muestra cuantitativa permitirá precisar si ambos tiempos verbales se han convertido en marcas de evidencialidad, en qué medida alguno de ellos ha condicionado al otro y qué tipo de evidencialidad pueden denotar. Asimismo, analizaremos qué lengua es la difusora de evidencialidad, qué direccionalidad ha experimentado y hasta qué punto es posible atestiguar las diferentes etapas por las que estos tiempos transitan hasta su especialización como fuente de información.
Sustantivos e interrogativas encubiertas en español
Authors: Devís Márquez Pedro Pablo
Published: June 2021

Since Baker (1968) suggested the term concealed question —which, following Autor (forthcoming), we translate as “interrogativa encubierta”— to refer to a DP that complements a verb and can be paraphrased by an indirect question (Preguntó el precio/Preguntó cuál era el precio), one of the most debated issues in the literature on languages other than Spanish has been, beside the concept of concealed question itself, what nouns can appear in this type of constructions. However, this issue has practically gone unnoticed in the descriptive grammar of Spanish. This article aims to deal with the ensuing shortcomings of Spanish grammar as well as to review the proposals that fall outside the context of Hispanic linguistics. Most importantly, on the assumption that concealed questions are predicate complements that are remaining elements of an elliptical specificational copular sentence within an indirect question, it will be shown that the type of noun, though irrelevant for the licensing of this kind of structure, plays an important role in its interpretation.
Freshwater-adapted sea bass Dicentrarchus labrax feeding frequency impact in a lettuce Lactuca sativa aquaponics system
Authors: Stathopoulou Paraskevi , Berillis Panagiotis , Vlahos Nikolaos , Nikouli Eleni , Kormas Konstantinos A. , Levizou Efi , Katsoulas Nikolaos , Mente Eleni
Published: June 2021

The aim of this study is to investigate the effect of three daily fish feeding frequencies, two, four and eight times per day (FF2, FF4, and FF8, respectively) on growth performance of sea bass (Dicentrarchus labrax)and lettuce plants (Lactuca sativa) reared in aquaponics. 171 juvenile sea bass with an average body weight of 6.80 ± 0.095 g were used, together with 24 lettuce plants with an average initial height of 11.78 ± 0.074 cm over a 45-day trial period. FF2 fish group showed a significantly lower final weight, weight gain and specific growth rate than the FF4 and FF8 groups. Voluntary feed intake was similar for all the three feeding frequencies treatmens (p > 0.05). No plant mortality was observed during the 45-day study period. All three aquaponic systems resulted in a similar leaf fresh weight and fresh and dry aerial biomass. The results of the present study showed that the FF4 or FF8 feeding frequency contributes to the more efficient utilization of nutrients for better growth of sea bass adapted to fresh water while successfully supporting plant growth to a marketable biomass.
No significant association of repeated messages with changes in health compliance in the COVID-19 pandemic: a registered report on the extended parallel process model
Authors: Yang Jingwen , Wu Xue , Sasaki Kyoshiro , Yamada Yuki
Published: June 2021

When people are confronted with health proposals during the coronavirus disease 2019 (COVID-19) pandemic, it has been suggested that fear of COVID-19 can serve protective functions and ensure public health compliance. However, health proposal repetition and its perceived efficacy also influence the behavior intention toward the proposal, which has not yet been confirmed in the COVID-19 context. The present study examined whether the extended parallel process model (EPPM) could be generalized to a naturalistic context like the COVID-19 pandemic. Additionally, we explored how repetition of a health proposal is involved with the EPPM. In this study, two groups of participants were exposed to the same health proposal related to COVID-19, where one group was exposed once and another group twice. Participants then filled out a questionnaire consisting of items concerning behavior intention and adapted from the Risk Behavior Diagnosis Scale. Structural equation modeling was used to determine the multivariate associations between the variables. Although the results showed that behavior intention is predicted by perceived efficacy, no significant influence of perceived threat was detected. Furthermore, no significant effect of repetition was found toward either response efficacy or perceived susceptibility. These findings indicate that to promote health compliance during the COVID-19 pandemic, it is more efficient to focus on health proposals’ perceived efficacy rather than the disease’s perceived threat. For future health communication research, the present study suggests improved analysis strategies and repeated manipulation of messages.
Characterisation of secretome-based immune responses of human leukocytes infected with variousMycobacterium tuberculosislineages
Authors: Kaewseekhao Benjawan , Roytrakul Sittiruk , Yingchutrakul Yodying , Laohaviroj Marut , Salao Kanin , Faksri Kiatichai
Published: June 2021

Background

Differences in immune responses against different lineages ofMycobacterium tuberculosis(Mtb), and by different types of immune cell, are still poorly understood. We aimed to compare the secretome-based immune responses among threeMtblineages and among immune-cell types. The immune responses were also investigated during infection and when the bacilli had been eliminated from the immune cells.

Methods

Human primary leukocytes were infected with strains representing three lineages ofMtb(East-Asian, Indo-Oceanic and Euro-American). Label-free GeLC MS/MS proteomic analysis of secretomes was performed. The response of each immune-cell type was compared with the appropriate interactome database for each.

Results

The expression pattern of proteins secreted byMtb-infected leukocytes differed amongMtblineages. The ancestral lineage (IO lineage) had a greater ability to activate MMP14 (associated with leukocyte migration) than did the more recent lineages (EA and EuA). During infection, proteins secreted by macrophages, dendritic cells, neutrophils and B-cells were associated with cell proliferation. Following clearance ofMtb, proteins associated with interferon signaling were found in macrophages, dendritic cells and neutrophils: proteins associated with antigen processing were found in B-cells and regulatory T-cells. Expression of immune response-related proteins from many immune-cell types might be suppressed byMtbinfection.Our study has provided a better insight into the host-pathogen interaction and immune response against differentMtblineages.
Notes on a newly discovered population of the Pygmy Copperhead Austrelaps labialis (Jan, 1859) in the Adelaide Hills, South Australia
Authors: Scott Shawn , Biffin Richard
Published: June 2021

The Pygmy Copperhead Austrelaps labialis is South Australia’s only endemic snake, being native to the Adelaide Mount Lofty Ranges and Fleurieu Peninsula; with an additional allopatric population on Kangaroo Island. Within the AMLR, it inhabits stringybark forests and adjacent dense vegetation, occupying a total area of ~150 km2. Here, we document a newly discovered and seemingly isolated population at the north-eastern extent of its known mainland distribution. We visited Lobethal Bushland Park from 2013–2018 and observed snakes of varying age and size, while documenting their ecology and behaviour. In late 2019, the site was decimated by catastrophic wildfire and its persistence here remains unknown. Alongside descriptions of our observations, we suggest measures for the conservation of this vulnerable population in its remnant habitat if it has survived the impacts of wildfire.
Linear and Non-Linear Modelling of Nigerian Crude Oil Prices
Authors: Leneenadogo Wiri , U Sibeate Pius
Published: June 2021

To model Nigeria crude oil prices, this analysis compared univariate linear models to univariate nonlinear models. The data for this analysis was gathered from the Central Bank of Nigeria (CBN) Monthly Statistical Bulletin. The upward and downward movement in the series revealed by the time plot suggests that the series exhibit a regime-switching pattern: the cycle of expansion and contraction. At lag one, the Augmented Dickey-Fuller test was used to test for stationarity. For univariate linear ARIMA (p, d, q)) and univariate non-linear MS-AR, seven models were estimated for the linear model and two for the non-linear model. The best model was chosen based on the criterion of least information criterion,  AIC (2.006612), SC (2.156581), and the maximum log-likelihood of   (-150.5480) for the crude oil prices were used to pick MS-AR (1) for the series. In analysing crude oil prices data, the MS-AR model proposed by Hamilton outperforms the linear autoregressive models proposed by Box- Jenkins. The model was used to predict the series' values over a one-year cycle (12 months).
Morphoecological characteristics of grasses used to restore degraded semi‐arid African rangelands
Authors: Mganga Kevin Z. , Kaindi Eric , Ndathi Aphaxard J.N. , Bosma Luwieke , Kioko Theophilus , Kadenyi Nancy , Wambua Stephen M. , van Steenbergen Frank , Musimba Nashon K.R.
Published: June 2021

Progressive loss of productivity and plant diversity is a concern in global rangelands. In African rangelands, this process is partly attributed to heavy and uncontrolled grazing by livestock and wildlife, leading to land degradation. Therefore, restoring such degraded rangelands is critical for enhancing ecosystem health and securing the livelihoods of millions of people.

Active restoration strategies, for example, reseeding using indigenous perennial grasses, have been identified as a viable ecological solution for restoring degraded African rangelands. Grass species indigenous to African rangelandsCenchrus ciliarisL. (African foxtail grass),Eragrostis superbaPeyr. (Maasai love grass),Enteropogon macrostachyus(Hochst. Ex A. Rich.) Monro ex Benth. (Bush rye grass),Chloris roxburghianaSchult. (Horsetail grass) andChloris gayanaKunth. cv Boma (Rhodes grass) were established in a semi‐arid rangeland in Africa under natural conditions to compare their morphoecological characteristics and suitability for use in ecological restoration. Biomass dry matter yields, plant densities, basal cover, seed production, tiller densities and plant height were measured.

Chloris gayanacv Boma andE. superbaproduced significantly higher dry matter biomass yields and attained higher seed production than other species. High biomass and seed production indicate their suitability to support livestock production and replenish depleted soil seed banks, respectively.

Enteropogon macrostachyusandC. ciliarisdisplayed significantly higher values for components of establishment and ecological restoration success, that is, plant densities, tiller densities and basal cover. Overall,C. roxburghianaranked lowest in the measured morphoecological characteristics.

Successful restoration of degraded African semi‐arid rangelands using indigenous grass reseeding can best be achieved through careful selection of grasses to take advantage of their specific morphoecological characteristics. This selection should primarily be informed by the intended use of the rangeland and the specific challenges of restoring each site.
Fundamental study on quality assurance (QA) procedures for a real‐time tumor tracking radiotherapy (RTRT) system from the viewpoint of imaging devices
Authors: Kimura Suguru , Miyamoto Naoki , Sutherland Kenneth L. , Suzuki Ryusuke , Shirato Hiroki , Ishikawa Masayori
Published: June 2021

Purpose

The real‐time tumor tracking radiotherapy (RTRT) system requires periodic quality assurance (QA) and quality control. The goal of this study is to propose QA procedures from the viewpoint of imaging devices in the RTRT system.

Methods

Tracking by the RTRT system (equips two sets of colored image intensifiers (colored I.I.s) fluoroscopy units) for the moving gold‐marker (diameter 2.0 mm) in a rotating phantom were performed under various X‐ray conditions. To analyze the relationship between fluoroscopic image quality and precision of gold marker coordinate calculation, the standard deviation of the 3D coordinate (σ3D [mm]) of the gold marker, the mean of the pattern recognition score (PRS) and the standard deviation of the distance between rays (DBR) (σDBR [mm]) were evaluated.

Results

When tracking with speed of 10‐60 mm/s, σDBR increased, though the mean PRS did not change significantly (p>0.05). On the contrary, the mean PRS increased depending on the integral noise equivalent quanta (∫NEQ) that is an indicator of image quality calculated from the modulation transfer function (MTF) as an indicator of spatial resolution and the noise power spectrum (NPS) as an indicator of noise characteristic.

Conclusion

The indicators of NEQ, MTF, and NPS were useful for managing the tracking accuracy of the RTRT system. We propose observing the change of these indicators as additional QA procedures for each imaging device from the commissioning baseline.
What Is the Persistence to Methotrexate in Rheumatoid Arthritis, and Does Machine Learning Outperform Hypothesis‐Based Approaches to Its Prediction?
Authors: Westerlind Helga , Maciejewski Mateusz , Frisell Thomas , Jelinsky Scott A , Ziemek Daniel , Askling Johan
Published: June 2021

Objective

The objectives of this study were to assess the 1‐year persistence to methotrexate (MTX) initiated as the first ever conventional synthetic disease‐modifying antirheumatic drug in new‐onset rheumatoid arthritis (RA) and to investigate the marginal gains and robustness of the results by increasing the number and nature of covariates and by using data‐driven, instead of hypothesis‐based, methods to predict this persistence.

Methods

Through the Swedish Rheumatology Quality Register, linked to other data sources, we identified a cohort of 5475 patients with new‐onset RA in 2006‐2016 who were starting MTX monotherapy as their first disease‐modifying antirheumatic drug. Data on phenotype at diagnosis and demographics were combined with increasingly detailed data on medical disease history and medication use in four increasingly complex data sets (48‐4162 covariates). We performed manual model building using logistic regression. We also performed five different machine learning (ML) methods and combined the ML results into an ensemble model. We calculated the area under the receiver operating characteristic curve (AUROC) and made calibration plots. We trained on 90% of the data, and tested the models on a holdout data set.

Results

Of the 5475 patients, 3834 (70%) remained on MTX monotherapy 1 year after treatment start. Clinical RA disease activity and baseline characteristics were most strongly associated with the outcome. The best manual model had an AUROC of 0.66 (95% confidence interval [CI] 0.60‐0.71). For the ML methods, Lasso regression performed best (AUROC = 0.67; 95% CI 0.62‐0.71).

Conclusion

Approximately two thirds of patients with early RA who start MTX remain on this therapy 1 year later. Predicting this persistence remains a challenge, whether using hypothesis‐based or ML models, and may yet require additional types of data.
Adaptive fixed‐time tracking control for stochastic pure‐feedback nonlinear systems
Authors: Liang Yanjun , Li Yuan‐Xin , Hou Zhongsheng
Published: June 2021

The article discusses the adaptive fixed‐time control problems for the stochastic pure‐feedback nonlinear systems. Different from the existing results, the priori information of unknown virtual control coefficients (UVCC) is no longer needed in this article, which is realized by emplying the bound estimation method and well‐defined smooth functions. A novel semi‐global practical fixed‐time stability criterion for the stochastic nonlinear systems is presented. Correspondingly, a new construction of Lyapunov function is proposed for the nonlinear stochastic system by adding the lower bounds of the UVCC. Based on the fuzzy logical system and fixed time stability theorem, a novel adaptive fuzzy fixed‐time tracking control algorithm for stochastic nonlinear system is raised firstly. By theoretical analysis, we can conclude that the whole variables of the controlled system are bounded almost surely and the output can track the desired reference signal to a very small compact set within a predefined fixed‐time interval. Finally, the raised method is illustrated by two simulation examples.
Stability analyses on a towed underwater vehicle motion control system using a high‐gain observer
Authors: Minowa Asuma , Toda Masayoshi
Published: June 2021

This paper presents stability analyses on a towed underwater vehicle (TUV) motion control system using movable wings. The control method utilized is an output‐feedback controller based on linear state‐feedback control and a high‐gain observer. In order to analyze the closed‐loop stability of the system, the singular perturbation method is employed. Not only the asymptotic stability of the system is proved, but also an estimate of its region of attraction is derived. To describe a region of attraction, we propose a method by employing a hyper rhombus, which is quite suitable for quadratic Lyapunov functions. Further, to obtain a less conservative estimate, a state‐space‐scaling method is devised and its efficacy is evaluated by comparing with the conventional estimation method. Then, results of regulation simulations with various initial conditions are provided, which explores the consistency and gap between the theoretical estimate and the simulation results, and the robustness of the control system. Finally, a depth‐tracking control system via switching controllers is constructed according to the results of the stability analysis which investigates configuration of multiple equilibria with different depths and their regions of attraction, and demonstration simulation results are presented to illustrate the validity of the perspective given by the stability analysis.
Ligand and Anion Co‐Leaching Induced Complete Reconstruction of Polyoxomolybdate‐Organic Complex Oxygen‐Evolving Pre‐Catalysts
Authors: Liu Xiong , Xia Fanjie , Guo Ruiting , Huang Meng , Meng Jiashen , Wu Jinsong , Mai Liqiang
Published: June 2021

The coordination compounds in the oxygen evolution reaction (OER) have been researched extensively. However, their poor durability (mostly < 100 h) and controversial reconstruction mechanism restrict their practical applications. Herein, a new‐type polyoxomolybdate‐organic complex (POMo) via wet‐chemistry synthesis with fixed coordination between metal centers (Ni2+ and [Mo8O26]4−) and 2‐Methylimidazole ligand is introduced. After introducing iron, a series of Fe‐doped Ni‐POMo with porous and amorphous structures are fabricated. These features accelerate the diffusion‐leaching processes of ligands and anions, resulting in rapid and complete phase reconstruction during alkaline OER. As a result, nickel‐iron (oxy)hydroxides with rich vacancies and poly‐/low‐crystalline features are in situ generated through dissolution‐redeposition, and serve as the OER‐active species. The optimized Fe0.052Ni‐POMo array pre‐catalyst has excellent activity and sustains ultrastable catalysis for 545 h. The complete reconstruction of POMo enables high catalytic durability (230 h) and stable active phase under realistic conditions (30 wt% KOH, 60.9 °C). Accordingly, the completely reconstructed catalysts with unique structures and ultrastable catalysis have the potential to be applied in industry.
Enabling the Unconstrained Epidermal Pulse Wave Monitoring via Finger‐Touching
Authors: Wang Xue , Yang Jun , Meng Keyu , He Qiang , Zhang Gaoqiang , Zhou Zhihao , Tan Xulong , Feng Zhiping , Sun Chenchen , Yang Jin , Wang Zhong Lin
Published: June 2021

Unconstrained measurement of physiological signals including electrocardiograph, respiration, and temperature by sensors through incorporation into commonly used objects has sparked a notable revolution in healthcare monitoring. However, unconstrained precision epidermal pulse wave monitoring is rarely reported. Although the current flexible skin‐mounted sensors can capture pulse waves, they lack the capability to perceive tiny pulse pressure in an unconstrained manner. Herein, utilizing thin‐film materials and multilevel microstructure design, an ultrathin and flexible sensor (UFS) with the features of high flexibility, shape‐adaptability, and ultra‐broad‐range high pressure sensitivity is proposed for unconstrained precision pulse wave sensing. Given these compelling features, the UFS is mounted to the surfaces of commonly used objects and successfully detects the fingertip pulse wave even under an ultra‐broad‐range finger‐touching force. Key cardiovascular parameters are also extracted from the acquired fingertip pulse wave accurately. Furthermore, a proof‐of‐concept healthcare system, by combining the UFS and flexible devices (for example, flexible phones or E‐newspapers) is demonstrated, offering a great advancement in developing an all‐in‐one system for IoT‐based bio‐health monitoring at all times and places.
Ferroic Halide Perovskite Optoelectronics
Authors: Liu Yongtao , Kim Dohyung , Ievlev Anton V. , Kalinin Sergei V. , Ahmadi Mahshid , Ovchinnikova Olga S.
Published: June 2021

Metal halide perovskites (MHPs) as one of the most active materials gained tremendous attention in the past decade because of their outstanding performance in optoelectronics. Owing to their perovskite structure, ferroelectricity is anticipated in this class of materials. However, whether MHPs are ferroelectric or not remains elusive. Recently, discussion regarding ferroelasticity in MHPs has been also raised. In addition, ionic motion and structural dynamics are well known in MHPs. The interplay of these phenomena including electric polarization, strain, ionic motion, and structural dynamics can have a significant impact on optoelectronics. Therefore, understanding the mechanism behind these phenomena and their interactions is critical in addressing the controversy about ferroicity of MHPs and developing functional devices. Here, the current findings about MHP's ferroicity are summarized and evaluated and a perspective for the future is provided. It is suggested that ionic motion and associated phenomena, coupled with ferroic behavior, are the main drivers behind MHPs functionality. The challenges are also discussed in probing MHPs’ ferroicity and what new measurement modalities are needed to fully understand and characterize MHP behavior. Finally, it is discussed how ferroic and strain can affect the optoelectronic performance of MHPs and how they can be used for engineering of higher performance devices.
Dielectric Elastomer Actuators, Neuromuscular Interfaces, and Foreign Body Response in Artificial Neuromuscular Prostheses: A Review of the Literature for an In Vivo Application
Authors: Bruschi Alessandro , Donati Davide Maria , Choong Peter , Lucarelli Enrico , Wallace Gordon
Published: June 2021

The inability to replace human muscle in surgical practice is a significant challenge. An artificial muscle controlled by the nervous system is considered a potential solution for this. Here, this is defined as a neuromuscular prosthesis. Muscle loss and dysfunction related to musculoskeletal oncological impairments, neuromuscular diseases, trauma or spinal cord injuries can be treated through artificial muscle implantation. At present, the use of dielectric elastomer actuators working as capacitors appears a promising option. Acrylic or silicone elastomers with carbon nanotubes functioning as the electrode achieve mechanical performances similar to human muscle in vitro. However, mechanical, electrical, and biological issues have prevented clinical application to date. Here materials and mechatronic solutions are presented which can tackle current clinical problems associated with implanting an artificial muscle controlled by the nervous system. Progress depends on the improvement of the actuation properties of the elastomer, seamless or wireless integration between the nervous system and the artificial muscle, and on reducing the foreign body response. It is believed that by combining the mechanical, electrical, and biological solutions proposed here, an artificial neuromuscular prosthesis may be a reality in surgical practice in the near future.
Programmable Assembly of π‐Conjugated Polymers
Authors: Hicks Garion E. J. , Li Sheng , Obhi Nimrat K. , Jarrett‐Wilkins Charles N. , Seferos Dwight S.
Published: June 2021

π‐Conjugated polymers have numerous applications due to their advantageous optoelectronic and mechanical properties. These properties depend intrinsically on polymer ordering, including crystallinity, orientation, morphology, domain size, and π–π interactions. Programming, or deliberately controlling the composition and ordering of π‐conjugated polymers by well‐defined inputs, is a key facet in the development of organic electronics. Here, π‐conjugated programming is described at each stage of material development, stressing the links between each programming mode. Covalent programming is performed during polymer synthesis such that complex architectures can be constructed, which direct polymer assembly by governing polymer orientation, π–π interactions, and morphological length‐scales. Solution programming is performed in a solvated state as polymers dissolve, aggregate, crystallize, or react in solution. Solid‐state programming occurs in the solid state and is governed by polymer crystallization, domain segregation, or gelation. Recent progress in programming across these stages is examined, highlighting order‐dependent features and assembly techniques that are unique to π‐conjugated polymers. This should serve as a guide for delineating the many ways of directing π‐conjugated polymer assembly to control ordering, structure, and function, enabling the further development of organic electronics.
Bubble Forming Films for Spatial Selective Cell Killing
Authors: Hua Dawei , Harizaj Aranit , Wels Mike , Brans Toon , Stremersch Stephan , De Keersmaecker Herlinde , Bolea‐Fernandez Eduardo , Vanhaecke Frank , Roels Dimitri , Braeckmans Kevin , Xiong Ranhua , Huang Chaobo , De Smedt Stefaan C. , Sauvage Félix
Published: June 2021

Photodynamic and photothermal cell killing at the surface of tissues finds applications in medicine. However, a lack of control over heat dissipation following a treatment with light might damage surrounding tissues. A new strategy to kill cells at the surface of tissues is reported. Polymeric films are designed in which iron oxide nanoparticles are embedded as photosensitizers. Irradiation of the films with pulsed laser light generates water vapor bubbles at the surface of the films. It is found that “bubble‐films” can kill cells in close proximity to the films due to mechanical forces which arise when the bubbles collapse. Local irradiation of bubble‐films allows for spatial selective single cell killing. As nanosurgery becomes attractive in ophthalmology to remove superficial tumors, bubble‐films are applied on the cornea and it is found that irradiation of the bubble‐films allows spatial and selective killing of corneal cells. As i) the photosensitizer is embedded in the films, which reduces its uptake by cells and spreading into tissues and ii) the bubble‐films can be removed from the tissue after laser treatment, while iii) a low laser fluence is sufficient to generate vapor bubbles, it is foreseen that bubble‐films might become promising for safe resection of superficial tumors.