bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanics and structure of carbon black gels under high-power ultrasound
Authors: Dagès Noémie , Lidon Pierre , Jung Guillaume , Pignon Frédéric , Manneville Sébastien , Gibaud Thomas
Published: May 2021

Colloidal gels made of carbon black particles dispersed in light mineral oil are “rheo-acoustic” materials, i.e., their mechanical and structural properties can be tuned using high-power ultrasound, sound waves with submicrometer amplitude and frequencies larger than 20 kHz. The effects of high-power ultrasound on the carbon black gel are demonstrated using two experiments: rheology coupled to ultrasound to test for the gel mechanical response and a time-resolved ultra-small-angle x-ray scattering experiment (TRUSAXS) coupled to ultrasound to test for structural changes within the gel. We show that high-power ultrasound above a critical amplitude leads to a complex viscoelastic transient response of the gels within a few seconds: a softening of its storage modulus accompanied by a strong overshoot in its loss modulus. Under high-power ultrasound, the gel displays a viscoelastic spectrum with glasslike features and a significant decrease in its yield strain. Those effects are attributed to the formation of intermittent microcracks in the bulk of the gel as evidenced by TRUSAXS. Provided that the shear rate is not large enough to fully fluidize the sample, high-power ultrasound also facilitates the flow of the gel, reducing its yield stress as well as increasing the shear-thinning index, thanks again to the formation of microcracks.
Changes in Muscle Control After Learning to Direct Pedal Forces in One-Legged Pedaling
Authors: Park Sangsoo , Van Emmerik Richard , Caldwell Graham E.
Published: May 2021

The aim of this study was to describe how major leg muscle activities are altered after learning a novel one-legged pedaling task. Fifteen recreational cyclists practiced one-legged pedaling trials during which they were instructed to match their applied pedal force to a target direction perpendicular to the crank arm. Activity in 10 major leg muscles was measured with surface electromyography electrodes. Improved upstroke task performance was obtained by greater activity in the hip and ankle flexor muscles, counteracting the negative effects of gravity. Greater quadriceps activities explained improved targeting near top dead center. Reduced uniarticular knee and ankle extensor downstroke activities were necessary to prevent freewheeling. Greater hamstring and tibialis anterior activities improved targeting performance near the bottom of the pedal stroke. The activity patterns of the biarticular plantarflexors changed little, likely due to their contributions as knee flexors for smooth upstroke pedaling motion. These results add to our understanding of how the degrees of freedom at the muscle level are altered in a cooperative manner to overcome gravitational effects in order to achieve the learning goal of the motor task while satisfying multiple constraints—in this case, the production of smooth one-legged pedaling motion at the designated mechanical task demands.
Tools suggest people reached Americas early
Authors: Curry Andrew
Published: May 2021

Skeptics question Mexican finds that suggest settlement during the last ice age.
Research cruises gingerly resume
Authors: Graber-Stiehl Ian
Published: May 2021

With quarantines, social distancing, and smaller crews, U.S. ocean science sets sail again.
Polio vaccinators are back after pandemic pause
Authors: Roberts Leslie
Published: May 2021

Mass campaigns resume after modelers warn about risk of "explosive" outbreaks.
‘Campfires’ may drive heating of solar atmosphere
Authors: Clery Daniel
Published: May 2021

Observations suggest small flares are corona's mystery heat source.
Carbohydrates, insulin, and obesity
Authors: Speakman John R. , Hall Kevin D.
Published: May 2021

Insulin plays a role in body fat regulation independent of dietary carbohydrates
The early origin of a birdlike inner ear and the evolution of dinosaurian movement and vocalization
Authors: Hanson Michael , Hoffman Eva A. , Norell Mark A. , Bhullar Bhart-Anjan S.
Published: May 2021

Revealing behavioral secrets in extinct species

Extinct species had complex behaviors, just like modern species, but fossils generally reveal little of these details. New approaches that allow for the study of structures that relate directly to behavior are greatly improving our understanding of the lifestyles of extinct animals (see the Perspective by Witmer). Hanson
et al.
looked at three-dimensional scans of archosauromorph inner ears and found clear patterns relating these bones to complex movement, including flight. Choiniere
et al.
looked at inner ears and scleral eye rings and found a clear emergence of patterns relating to nocturnality in early theropod evolution. Together, these papers reveal behavioral complexity and evolutionary patterns in these groups.

Science
, this issue p.
601
, p.
610
; see also p.
575
The people at the dawn of civilization
The Sumerians
Paul Collins Reaktion Books, 2021. 208 pp.
Authors: Robinson Andrew
Published: May 2021

Sumerian language and culture take center stage in a new anthropological analysis
Rapid antigen testing in COVID-19 responses
Authors: García-Fiñana Marta , Buchan Iain E.
Published: May 2021

SARS-CoV-2 transmission was reduced with measures centered on rapid antigen testing
Engineering Posttranslational Regulation of Glutamine Synthetase for Controllable Ammonia Production in the Plant Symbiont Azospirillum brasilense
Authors: Schnabel Tim , Sattely Elizabeth
Published: May 2021

Nitrogen is the most limiting nutrient in modern agriculture. Free-living diazotrophs, such as
Azospirillum
, are common colonizers of cereal grasses and have the ability to fix nitrogen but natively do not release excess ammonia.
Hypokalaemic paralysis as the initial clinical presentation of Sjogren’s syndrome induced distal renal tubular acidosis
Authors: Kielty Jennifer M , Ryan Paul , Sexton Donal , Kelly Yvelynne P
Published: May 2021

A 41-year-old woman presented by ambulance with a 1-day history of new-onset paralysis and nausea and vomiting ongoing for 48 hours. She had no history of any similar episodes. Biochemical analysis showed profound hypokalaemia with a non-anion gap metabolic acidosis. Her initial serum chloride was within the normal range. She had significant electrocardiographic changes on admission with ST depression, U waves and a prolonged QT interval. Urinary anion gap supported the diagnosis of a distal renal tubular acidosis. Subsequent connective tissue disease serology confirmed previously undiagnosed Sjogren’s syndrome. Successful recovery for this patient required multidisciplinary input from the intensive care, nephrology and neurology teams.
Rapid resolution of a third nerve palsy from pituitary apoplexy
Authors: Hanna Verina , Mednick Zale , Micieli Jonathan
Published: May 2021

A 49-year-old man presented with new onset headache and diplopia, with right ptosis and limitation of extraocular movements consistent with a third nerve palsy. He had a known diagnosis of a non-functioning pituitary adenoma, and his presentation and neuroimaging were consistent with ischaemic pituitary apoplexy. The patient was otherwise stable with no signs of optic neuropathy or endocrine abnormality. He was observed with close interval follow-up and reported resolution of symptoms within 4 days after onset. Pituitary apoplexy is a potentially life-threatening condition often managed with initial medical stabilisation followed by neurosurgical decompression. The guidelines regarding the utility of surgery in patients with isolated ocular motility disorders are unclear, and recent retrospective studies suggested that outcomes may be similar in patients managed conservatively. This case demonstrates that rapid resolution of an isolated third nerve palsy may occur in this setting, and that observation is a reasonable initial management strategy.
Development and rapid rollout of The QUiPP App Toolkit for women who arrive in threatened preterm labour
Authors: Carlisle Naomi , Watson Helena A , Shennan Andrew H
Published: May 2021

Background

Often the first opportunity for clinicians to assess risk of preterm birth is when women present with threatened preterm labour symptoms (such as period-like pain, tightening’s or back ache). However, threatened preterm labour symptoms are not a strong predictor of imminent birth. Clinicians are then faced with a complex clinical dilemma, the need to ameliorate the consequences of preterm birth requires consideration with the side-effects and costs. The QUiPP app is a validated app which can aid clinicians when they triage a women who is in threatened preterm labour.

Aim

Our aim was to produce a toolkit to promote a best practice pathway for women who arrive in threatened preterm labour.

Methods

We worked with two hospitals in South London. This included the aid of a toolkit midwife at each hospital. We also undertook stakeholder focus groups and worked with two Maternity Voice Partnership groups to ensure a diverse range of voices was heard in the toolkit development. While we aimed to produce the toolkit in September 2020, we rapidly rolled out and produced the first version of the toolkit in April 2020 due to COVID-19. As the QUiPP app can reduce admissions and hospital transfers, there was a need to enable all hospitals in England to have access to the toolkit as soon as possible.

Results

While the rapid rollout of The QUiPP App Toolkit due to COVID-19 was not planned, it has demonstrated that toolkits to improve clinical practice can be produced promptly. Through actively welcoming continued feedback meant the initial version of the toolkit could be continually and iteratively refined. The toolkit has been recommended nationally, with National Health Service England recommending the app and toolkit in their COVID-19 update to the Saving Babies Lives Care Bundle and in the British Association of Perinatal Medicine Antenatal Optimisation Toolkit.
Effect of medical treatment on heart failure incidence in patients with a systemic right ventricle
Authors: Ladouceur Magalie , Segura de la Cal Teresa , Gaye Bamba , Valentin Eugenie , Ly Reaksmei , Iserin Laurence , Legendre Antoine , Mousseaux Elie , Li Wei , Rafiq Isma , Kempny Aleksander , Barradas-Pires Ana , Babu-Narayan Sonya V , Gatzoulis Michael A , Dimopoulos Konstantinos
Published: May 2021

Background

To date, clinical trials have been underpowered to demonstrate a benefit from ACE inhibitors (ACEis) or angiotensin II receptor blockers (ARBs) in preventing systemic right ventricle (sRV) failure and disease progression in patients with transposition of the great arteries (TGA). This observational study aimed to estimate the effect of ACEi and ARB on heart failure (HF) incidence and mortality in a large population of patients with an sRV.

Methods

Data on all patients with an sRV under active follow-up at two tertiary centres between January 2007 and September 2018 were studied. The effect of ACEi and ARB on the incidence of HF and mortality was estimated using a propensity score weighting approach to control confounding.

Results

Among the 359 patients with an sRV (32.2 (IQR 26.4–38.3) years, 59.3% male, 66% complete TGA with atrial switch repair and 34% congenitally corrected TGA), 79 (22%) had a moderate to severe sRV dysfunction and 138 (38%) were treated with ACEi or ARB. Fourteen (3.6%) patients died, 8 (2.1%) underwent heart transplantation and 46 (11.8%) had a new HF event over a median follow-up of 7.1 (IQR 4.0–9.4) years. On multivariate Cox analysis with adjustment using propensity score weighting approaches, ACEi or ARBs treatment was not significantly associated with a lower HF incidence or mortality in patients with an sRV.

Conclusions

Despite significant neurohormonal activation described in patients with an sRV, there is still no evidence of a beneficial effect of ACEi or ARB on morbidity and mortality in this population.
Free Fallin’? The decline in evidence-based decision-making by Canada’s protected areas managers
Authors: Lemieux Christopher J. , Halpenny Elizabeth A. , Swerdfager Trevor , He Mu , Gould A. Joyce , Carruthers Den Hoed Don , Bueddefeld Jill , Hvenegaard Glen T. , Joubert Brian , Rollins Rick
Published: May 2021

The conservation of biodiversity requires various forms of evidence to ensure effective outcomes. In this study, we provide an updated assessment of the state of evidence-based decision-making in Canada’s protected areas organizations by examining practitioner perceptions of: ( i) the value and use of various forms of evidence, ( ii) the availability of evidence to support decisions, and ( iii) the extent to which various institutional and behavioural barriers influence the use of evidence. Our results compare national surveys conducted in 2019 and 2013, revealing a significant and concerning decline in the use of all forms of evidence. We found significant declines in the use of peer-reviewed literature, local knowledge, and Indigenous knowledge. Our results correspondingly demonstrate a host of systemic barriers to the effective use of evidence, including a lack of trust, how to deal with uncertainty, and limited training. These challenges persist at a time when the quantity of information is greater than ever, and recognition of the value of Indigenous knowledge is relatively high (and increasing). Leadership is required to cultivate more relevant evidence, to embed scientists and Indigenous Knowledge-Holders in conservation organizations, to (re)establishing knowledge sharing forums, and to establish accountability and reporting measures to support efforts aimed at effectively achieving Canada’s biodiversity conservation goals.
Accelerating Data-Parallel Neural Network Training with Weighted-Averaging Reparameterisation
Authors: Ramroach Sterling , Joshi Ajay
Published: May 2021

Recent advances in artificial intelligence has shown a direct correlation between the performance of a network and the number of hidden layers within the network. The Compute Unified Device Architecture (CUDA) framework facilitates the movement of heavy computation from the CPU to the graphics processing unit (GPU) and is used to accelerate the training of neural networks. In this paper, we consider the problem of data-parallel neural network training. We compare the performance of training the same neural network on the GPU with and without data parallelism. When data parallelism is used, we compare with both the conventional averaging of coefficients and our proposed method. We set out to show that not all sub-networks are equal and thus, should not be treated as equals when normalising weight vectors. The proposed method achieved state of the art accuracy faster than conventional training along with better classification performance in some cases.
The Phasor Plot: A Universal Circle to Advance Fluorescence Lifetime Analysis and Interpretation
Authors: Malacrida Leonel , Ranjit Suman , Jameson David M. , Gratton Enrico
Published: May 2021

The phasor approach to fluorescence lifetime imaging has become a common method to analyze complicated fluorescence signals from biological samples. The appeal of the phasor representation of complex fluorescence decays in biological systems is that a visual representation of the decay of entire cells or tissues can be used to easily interpret fundamental biological states related to metabolism and oxidative stress. Phenotyping based on autofluorescence provides new avenues for disease characterization and diagnostics. The phasor approach is a transformation of complex fluorescence decays that does not use fits to model decays and therefore has the same information content as the original data. The phasor plot is unique for a given system, is highly reproducible, and provides a robust method to evaluate the existence of molecular interactions such as Förster resonance energy transfer or the response of ion indicators. Recent advances permitquantification of multiple components from phasor plots in fluorescence lifetime imaging microscopy, which is not presently possible using data fitting methods, especially in biological systems.
Structures and Functions of Chromatin Fibers
Authors: Chen Ping , Li Wei , Li Guohong
Published: May 2021

In eukaryotes, genomic DNA is packaged into chromatin in the nucleus. The accessibility of DNA is dependent on the chromatin structure and dynamics, which essentially control DNA-related processes, including transcription, DNA replication, and repair. All of the factors that affect the structure and dynamics of nucleosomes, the nucleosome–nucleosome interaction interfaces, and the binding of linker histones or other chromatin-binding proteins need to be considered to understand the organization and function of chromatin fibers. In this review, we provide a summary of recent progress on the structure of chromatin fibers in vitro and in the nucleus, highlight studies on the dynamic regulation of chromatin fibers, and discuss their related biological functions and abnormal organization in diseases.
Development of a Highly Sensitive Imprinted Electrochemical Sensor for the Detection of Hydrocortisone in Wastewater
Authors: Cui Xia , Han Jili , Chen Guoning , Wang Lu , Luo Zhimin , Chang Chun , Zhang Jia , Fu Qiang
Published: May 2021

The existence of hydrocortisone in water resources is a serious threat to human health. However, the rapid and sensitive detection methods for hydrocortisone in wastewater are still lacking. Meanwhile, due to the weak redox activity of hydrocortisone, electrochemical technique cannot be used to detect hydrocortisone directly. Therefore, molecularly imprinted technique combined with prussian blue nanoparticles was synthesized for detecting HC indirectly in this work. We fabricated a novel and highly sensitive molecularly imprinted sensor based on the polydopamine/electro-reduced graphene oxide, which was used for the specific recognition of hydrocortisone in water samples. The prussian blue nanoparticles were introduced as probes to reflect the concentration of the target. The morphology of the prepared sensors was characterized by the scanning electron microscopy. And the feature of the imprinted electrode was performed by the cyclic voltammetry and differential pulse voltammetry. Under the optimal experimental conditions, the relative current signal of prussian blue decreased linearly with the increase of hydrocortisone concentration with a limit of detection 0.006 nM. Moreover, the imprinted sensor had a much higher affinity towards hydrocortisone than other analogues. Then, this system was successfully applied to determine hydrocortisone in real wastewater samples with workable results.
Impact of Carbon Support Structure on the Durability of PtCo Electrocatalysts
Authors: O’Brien T. E. , Herrera S. , Langlois D. A. , Kariuki N. N. , Yu H. , Zachman M. J. , Myers D. J. , Cullen D. A. , Borup R. L. , Mukundan R.
Published: May 2021

High performing, low-Pt content fuel cell membrane electrode assemblies (MEAs) are critical to the economic viability of proton exchange membrane fuel cells (PEMFCs) for the transportation industry. Considerable research has been conducted to reduce the Pt content in fuel cells, leading to the development of transition metal alloys, such as Platinum-Cobalt (PtCo). The degree of degradation of PtCo catalysts can be impacted by not only the composition and morphology of the catalyst particle itself, but also its interactions with the carbon support. In this study several low-PtCo MEAs were fabricated, with various combinations of porous and solid carbon cathode catalyst supports. The MEAs were subjected to an accelerated stress test (AST), and the catalyst degradation characterized using electrochemical, X-ray scattering, and electron microscopy techniques. Porous supports retain more of their electrochemically-active surface area (ECSA) and demonstrate higher performance after the AST. This is believed to be due to the ability of the porous supports to trap the metal particles within the pores, slowing their dissolution/precipitation, and agglomeration. However porous supports also exhibit greater increases in transport resistance probably associated with enhanced Co leaching under the AST conditions.
Proficient Sanitary Wastewater Treatment in Laboratory and Field-Scale Microbial Fuel Cell with Anti-Biofouling Cu0.5Mn0.5Fe2O4 as Cathode Catalyst
Authors: Das Indrasis , Das Sovik , Das Swati , Ghangrekar M. M.
Published: May 2021

For successful field-scale application of microbial fuel cell (MFC), the power recovery from field-scale MFC needs to be improved considerably with simultaneous reduction in its fabrication cost. These problems can be addressed by applying low-cost and efficient cathode catalyst in MFCs. In this regard, Cu0.5Mn0.5Fe2O4 (CuMnFe) was synthesized and applied as cathode catalyst in lab and field-scale MFCs with capacity of 150 ml and 25 l, respectively. Lab-scale MFC having CuMnFe as cathode catalyst demonstrated power density of 176.0 ± 8.2 mW m−2, which was competitive with MFC having Pt as cathode catalyst (183.0 ± 12.6 mW m−2) and it was about seven times higher than control MFC (25.5 ± 4.5 mW m−2) having no catalyst. Application of CuMnFe as cathode catalyst in field-scale MFC produced power density of 7.74 mW m−2, which was three-times higher than the power produced by the field-scale MFC operated without any cathode catalyst (2.58 mW m−2). The cathode catalyst CuMnFe also demonstrated excellent anti-biofouling properties, which in turn improved the power production of field-scale MFC. Therefore, low-cost CuMnFe can be anticipated as an efficacious cathode catalyst for application in MFCs that would produce long term stable higher power, while offering simultaneous treatment to wastewater.
Hydrogen Gas Promoted Self-Limiting Copper Monolayer Deposition on Platinum
Authors: Loichet Torres Paulette A. , El-Sayed Hany A. , Schwämmlein Jan N. , Friedrich Franziska , Gasteiger Hubert A.
Published: May 2021

A hydrogen gas promoted approach to achieve copper underpotential deposition (UPD) on platinum surfaces was developed to form a copper monolayer on polycrystalline platinum and carbon supported platinum catalysts (Pt/C) in a Cu2+-containing electrolyte, serving as alternative to the commonly used electrochemical deposition methods that require external potential control. Initially, the amount of deposited copper in the presence of dissolved hydrogen was determined via fast stripping voltammetry. Subsequently, by monitoring the open circuit potential drop of Pt disk and Pt/C thin-film electrodes upon exposure of an air saturated electrolyte to H2 containing gas, it could be shown that self-limiting Cu coverages of essentially one monolayer can reliably be obtained for 0.1% and 3% H2/Ar mixtures. In a second part, a cell was designed aiming to facilitate the gram-scale preparation of CuUPDPt/C catalysts by the H2 gas promoted approach. The formation of a Cu UPD layer on the Pt nanoparticles supported on carbon with a coverage slightly higher than a monolayer was successfully validated. However, the reaction cell introduced non-idealities at the solution/gas interface, which would need to be optimized to achieve a perfectly self-limiting Cu monolayer on the Pt nanoparticles by the H2 promoted deposition.
Efficient Dissolution of Tungsten Carbide Using an Oxygen-Containing Molten Salt
Authors: Zhang Qinghua , Xi Xiaoli , Zhang Liwen , Nie Zhuanghua , Nie Zuoren
Published: May 2021

Efficient electrochemical dissolution of tungsten carbide is crucial to obtain an efficient recovery of cemented carbide via molten salt electrolysis. Based on the interfacial process, the dissolution mechanism of tungsten carbide in oxygen-containing molten salt was investigated via a mass loss test, electrochemical tests, and first principles calculations. Through the mass loss study, it was found that, although the tungsten-carbon bond was extremely stable, an effective electrochemical dissolution of tungsten carbide could also occur in the presence of oxygen ions. The electrochemical tests demonstrated that an increase in oxygen ions leads to a continuous substitution of chloride ions with oxygen ions on the anode surface. These oxygen ions are further converted into oxygen atoms under the action of an electric field. The oxygen atoms on the anode surface can then effectively destroy the tungsten-carbon bond and promote mass loss, as demonstrated by first principles calculations. In addition, the appearance of maximum mass can be related to the saturation of the electrostatic adsorption of oxygen ions.
Resolving Anodic Current and Temperature Distributions in a Polymer Electrolyte Membrane Water Electrolysis Cell Using a Pseudo-Two-Phase Computational Fluid Dynamics Model
Authors: Lopata J. , Kang Z. , Young J. , Bender G. , Weidner J. W. , Cho H-S. , Shimpalee S.
Published: May 2021

Expanding upon our prior experimental work, we constructed a three-dimensional model of a polymer electrolyte membrane water electrolyzer using computational fluid dynamics. We applied the assumption of pseudo-two-phase flow, the flow of two phases with equal velocity. Experimental data were used to obtain parameters and to determine the conditions under which this model was valid. Anodic distributions of current density, temperature, liquid saturation, and relative humidity were obtained at various flow rates. The overall current density and temperature difference from inlet to outlet at the anode agreed strongly with experimental measurements under most circumstances. This verification allowed us to further examine the apparent gas coverage calculated from experimental and model temperature data. Results suggested a low liquid saturation and low relative humidity at the anode due to the consumption of liquid water and water vapor. However, we questioned the accuracy of the pseudo-two-phase assumption at low water feed rates. We concluded that the model was applicable to systems with liquid water feed rates greater than 0.6 ml min−1 cm−2. Therefore, it is a fair screening method that can advise which operating conditions lead to excessive temperatures or drying at the anode, thereby promoting the longevity of the membrane and catalyst.
Review—Design and Synthesis of Fluorescence Sensing Metal-Organic Frameworks
Authors: Yang Jie , Ni Wang , Ruan Bo , Tsai Lung-Chang , Ma Ning , Shi Dean , Jiang Tao , Tsai Fang-Chang
Published: May 2021

Metal-organic frameworks (MOFs) are researched extensively in adsorption and separation, energy storage and other fields. However, researches of MOFs on fluorescence sensors are relatively few and in the initial stage. In this review, recent advances of MOFs-based fluorescence sensors are systematically quoted, including materials design and the manufacturing strategies, as are the emerging applications about the detection of various analytes, such as metal ion, anion and small molecule. In allusion to the disparate analytes, the material of MOFs-based fluorescence sensor needs earnestly designing to matching specific analyte and the manufacturing strategies needs to be carefully considered to enhance sensitivity and selectivity. Due to the fluorescence, material diversity and adjustable structure, MOFs can suitably meet the design and construction of fluorescence sensor, demonstrating the great potential as fluorescence sensor.
Perspective—A Robotic Actuation System Made of Artificial Cells and Gels
Authors: Yoshida Kazunari
Published: May 2021

This paper introduces recent research on liposome deformation techniques and 3D hydrogel printing. The photo-responsive molecules and the molecular insertion into lipid bilayers induces liposome deformation. The 3D hydrogel printing enables us to freely fabricate the hydrogel objects. It is expected that the combination of such techniques achieves the development of living-creature-like robots. We show the future prospects of the development of soft robots comprising multi-liposomes and hydrogels. We are going to be able to construct a heart-like pump and cellular-slime-mold-like swarm because of advances in researches on deformable liposomes and functional hydrogels.
Equivalent Cauchy Sequences in

q

1

,

q

2

-Quasi Metric-Like Space and Applications to Fixed-Point Theory
Authors: Sila Eriola , Duraj Sidite , Hoxha Elida
Published: May 2021

This paper introduces the concept of

q

1

,

q

2

-quasi metric-like space

X
,
p

and delves into some topological properties of it. A necessary and sufficient condition related to equivalent Cauchy sequences and Cauchy sequences in

X
,
p

have been proved. Furthermore, the results of the fixed point are shown in the setting of

q

1

,

q

2

-quasi metric-like space as applications of conditions of equivalent Cauchy sequences. Besides, some instances are inclined to epitomize the examined consequences.
Impact of the COVID-19 Pandemic on Radiotherapy Supply
Authors: Tramacere Francesco , Asabella Artor Niccoli , Portaluri Maurizio , Altini Corinna , Ferrari Cristina , Bardoscia Lilia , Sardaro Angela
Published: May 2021

Background. The impetuous entrance of the COVID-19 pandemic in Italy in March 2020, after the onset and diffusion in China, found the health system widely unfit to face the large amount of infected patients. The matter of this investigation was to evaluate how pandemic fear and guidelines for limiting the diffusion of SARS-CoV-2 virus could have impacted the regular supply of radiotherapy (RT) and the outcome of the treatments. Materials and Methods. From March 9, 2020, to May 29, 2020, a register has been established to record patients that cancelled or postponed the RT appointment. The reasons were as follows: (1) patients whose appointments were postponed by the staff according to national guidelines; (2) patients who asked themselves to postpone the appointment; (3) patients who interrupted the treatment for causes directly or indirectly related to the pandemic; (4) patients who cancelled their care path. Results. A total number of 277 patients started regular RT, and 384 respected their computed tomography (CT) simulation appointment, but 60 of them had alteration of their therapeutic pathway. Among these, 18 cancelled their appointment. 42 patients asked to postpone their procedure. Twenty-seven out of 42 adduced directly or indirectly SARS-CoV-2 infection-related reasons. Conclusions. The COVID-19 pandemic affected the regular RT delivery to oncologic patients, owing to the delay or cancellation of procedures with the likely effect to observe worsening of local disease control and reduced survival rates in the future.
Quantitative Characterization and Determination of the Main Factors That Control Fracture Development in the Lower Paleozoic Shale in Southeastern Chongqing, China
Authors: Zhang Zhiping , Kong Xiangye , Chen Qing , Zhang Ye , Deng Zhi , Yu Chuan , Lei Zhian , Zhang Haijie , Wang Xiaofeng , Yao Guanghua , Yang Licheng , Tan Xianfeng
Published: May 2021

The Longmaxi and Niutitang Formations are typical shale reservoirs in southeastern Chongqing. Since the Paleozoic, southeastern Chongqing has experienced multistage tectonic movement and diagenesis, resulting in the formation of a large number of natural fractures. In shale reservoirs, fractures not only provide seepage channels for oil and gas migration but also play an important role in the oil and gas reservoir space. Natural fractures provide a flow path from source rock to reservoir during oil filling and connect hydraulic fractures, matrix pores, and boreholes during production. Therefore, identifying the main factors that control the development of natural fractures in the Longmaxi and Niutitang Formations in southeastern Chongqing has a guiding significance for the efficient development of shale reservoirs in this area. By considering the Longmaxi and Niutitang Formation shales as case studies, using field outcrops, drilling cores, and other data, and conducting X-ray diffraction (XRD) analysis as well as total organic carbon (TOC) measurements, the quantitative parameter characteristics and main factors that control the development of natural fractures in reservoir shales were examined in detail. The results obtained showed that there are three types of fractures in the lower Paleozoic shale in southeastern Chongqing, which are structural, diagenetic, and abnormal high-pressure fractures. Among them, the fractures in the Longmaxi Formation shale, which are relatively abundant, predominantly consist of low-angle and high-angle inclined fractures, while the Niutitang Formation predominantly consists of high-angle fractures. Additionally, the investigation of fracture size and fracture density, as well as correlation analyses, showed that the fractures of the Lower Paleozoic shale are predominantly micro fractures that play a key role in improving reservoir seepage. It was also noted that the development of fractures is affected by several factors, including tectonic stress, mineral composition, organic carbon content, and rock thickness. The degree of fracture development was found to be positively correlated with brittle mineral and quartz contents, and high organic matter contents also significantly favored the formation micro fractures.
Increasing Minority Recall Support Vector Machine Model for Imbalanced Data Classification
Authors: Wu Chunye , Wang Nan , Wang Yu
Published: May 2021

Imbalanced data classification is gaining importance in data mining and machine learning. The minority class recall rate requires special treatment in fields such as medical diagnosis, information security, industry, and computer vision. This paper proposes a new strategy and algorithm based on a cost-sensitive support vector machine to improve the minority class recall rate to 1 because the misclassification of even a few samples can cause serious losses in some physical problems. In the proposed method, the modification employs a margin compensation to make the margin lopsided, enabling decision boundary drift. When the boundary reaches a certain position, the minority class samples will be more generalized to achieve the requirement of a recall rate of 1. In the experiments, the effects of different parameters on the performance of the algorithm were analyzed, and the optimal parameters for a recall rate of 1 were determined. The experimental results reveal that, for the imbalanced data classification problem, the traditional definite cost classification scheme and the models classified using the area under the receiver operating characteristic curve criterion rarely produce results such as a recall rate of 1. The new strategy can yield a minority recall of 1 for imbalanced data as the loss of the majority class is acceptable; moreover, it improves the

g

-means index. The proposed algorithm provides superior performance in minority recall compared to the conventional methods. The proposed method has important practical significance in credit card fraud, medical diagnosis, and other areas.
Novel Method to Improve the Uniformity of 7T Body MR Images
Authors: Park Bu S. , Rajan Sunder S.
Published: May 2021

When using ultrahigh-field MR systems (7T), the variations in the RF magnetic field can lead to significant loss in image uniformity. To optimize the overall MR image quality, the image region is divided into multiple smaller regions of interest (the ROIs), which can be independently optimized using transmit array optimization techniques including RF shimming, to improve RF magnetic fields and image intensity. Electromagnetic numerical simulations and corresponding transverse magnetization (|Mt|) acquired using the Bloch equation-based MRI simulator are used to evaluate the proposed method. Compared to the simulation results of quadrature driving method, mean and standard deviation (SD) of |Mt| in the full image (an inner diameter of 500 mm) were improved 47% (mean) and 48% (SD), whereas 94% (max) and 97% (mean) improved in the unaveraged SAR using the proposed method. The uniformity of |Mt| acquired using the method was especially improved in the peripheral region of the selected phantom image compared to that of other methods. The proposed method using multiple independently optimized ROIs and numerical simulations significantly improved the uniformity of |Mt| body images at 7T. This technique would be generally applicable to any high-field strength MR systems, which generate short RF wavelengths compared to the field of view.
A Fixed-Time Hierarchical Formation Control Strategy for Multiquadrotors
Authors: Huang Miaojie , Lu Qiang
Published: May 2021

This paper deals with the problem of multiquadrotor collaborative control by developing and analyzing a new type of fixed-time formation control algorithm. The control strategy proposes a hierarchical control framework, which consists of two layers: a coordinating control layer and a tracking control layer. On the coordinating control layer, according to the fixed-time consistency theory, the virtual position and virtual velocity of each quadrotor are calculated and acquired to form a virtual formation, and the virtual velocity reaches consistency. On the tracking control layer, the real position and the real velocity track the virtual position and the virtual velocity, respectively. Thus, multiquadrotor can achieve the required formation shape and velocity consensus. Finally, the comparative simulations are carried out to illustrate the feasibility and superiority of the proposed fixed-time hierarchical formation control method for multiquadrotor collaborative control.
Identifying the Main Predictors of Length of Care in Social Care in Portugal
Authors: Lopes Hugo , Guerreiro Gracinda , Esquível Manuel , Mateus Céu
Published: May 2021

In this paper, we aim to identify the main predictors at admission and estimate patients’ length of care (LOC), within the framework of the Portuguese National Network for Long-Term Integrated Care, considering two care settings: (1) home and community-based services (HCBS) and (2) nursing home (NH) units comprising Short, Medium, or Long Stay Care. This study relied on a database of 20,984 Portuguese individuals who were admitted to the official long-term care (LTC) system and discharged during 2015. A generalised linear model (GLM) with gamma distribution was adjusted to HCBS and NH populations. Two sets of explanatory variables were used to model the random variable, LOC, namely, patient characteristics (age, gender, family/neighbour support, dependency levels at admission for locomotion, cognitive status, and activities of daily living [ADL]) and external factors (referral entity, number of beds/treatment places per 1,000 inhabitants ≥65 years of age), maturity and occupancy rate of the institution, and care setting. The features found to most influence the reduction of LOC are: male gender, having family/neighbour support, being referred by hospitals to NH (or by primary care to HCBS), and being admitted to units with a lower occupancy rate and with fewer months in operation. Regarding the dependency levels, as the number of ADL considered “dependent” increases, LOC also increases. As for the cognitive status, despite the opposite trend, it was only statistically significant for NH. Furthermore, two additional models were applied by including “death,” although this feature is not observable upon admission. By creating a model that allows for an estimate of the expected LOC for a new individual entering the Portuguese LTC system, policy-makers are able to estimate future costs and optimise resources.
“Água é vida”: política, memória e experiência nos conflitos em torno da mineração em Cajamarca, Peru
Authors: Penãfiel Adriana Paola Paredes , Radomsky Guilherme Francisco Waterloo
Published: May 2021

Neste artigo analisamos como se constitui a defesa da vida e das águas em conflitos socioambientais na região de Cajamarca, norte do Peru. A disputa por água tem se tornado nos últimos anos uma questão central da vida das pessoas em uma região que é foco de exploração mineradora e para a qual se utilizam discursos e apelos para evocar os benefícios quanto ao desenvolvimento que ela pode realizar. Ao longo de pesquisa etnográfica se testemunhou o esforço de pessoas e coletivos para defender as águas dos rios, das lagoas e dos canais de irrigação nos Andes em paralelo ao modo como defendem a vida. Ao fazê-lo, articulam memórias, aprendizagens locais e experiências coletivas para romper com os papeis que a ordem política convencional lhes destinou, constituindo criativamente modos próprios de pensar e pôr em prática projetos de vida e resistir à opulência das empresas mineradoras ou às autoridades estatais.
El camino y el caminar: fuentes históricas de los rarámuri de la Sierra Tarahumara, México
Authors: Ramírez María Isabel Martínez
Published: May 2021

A lo largo de este artículo muestro que, para los rarámuri o tarahumaras que residen en el Norte de México, los caminos y el caminar constituyen un contexto epistemológico caracterizado por revelar los procedimientos necesarios para producir y transmitir contenidos concretos. El objetivo de este escrito es exponer las narrativas recopiladas en dicho contexto para examinar la relación entre la enunciación y los soportes geográficos que son reconocidos como evidencia de los hechos relatados y como generadores de la enunciación. La meta es analizar los procedimientos nativos de la enunciación con el fin de postular una simetría entre estos registros y las fuentes documentales de carácter burocrático y administrativo que el Estado mexicano ha producido durante los siglos XX y XXI y que han servido como un pilar para construir la historia de/sobre los rarámuri. El objeto ulterior es aportar a la construcción de un espacio de existencia para la historia rarámuri.
“Eu tô vivo e isso aqui é minha vida agora”: produção de territórios e condições de existência no cotidiano de uma prisão
Authors: Antunes Sara Vieira
Published: May 2021

A partir da experiência de duas pessoas aprisionadas em uma penitenciária feminina de São Paulo, o presente texto reflete sobre os modos de produção de territórios e condições de existência no cotidiano do cárcere. As formas criativas e táticas de adequar os ambientes de modo a torná-los morada e as redes de suporte, favores e afetos tecidas ao longo de anos são justapostas às formas de dominação e tentativas institucionais de anulação do sujeito aprisionado. Em situações extremas, o corpo torna-se território último de resistência, a partir do qual são agenciadas linhas de fuga capazes de produzir verdadeiras máquinas de guerra contra o Estado, de modo a fazer vida perseverar. Por meio de narrativas que fazem ver diferentes formas de produzir territórios de vidas vivíveis, busca-se discutir as fronteiras entre subjugação, resistência e criação no cotidiano de uma prisão.
Gramsci e o debate da derivação do Estado: o conceito de hegemonia em Joachim Hirsch e Bob Jessop
Authors: Silva Gustavo Carneiro da
Published: May 2021

Este artigo visa apresentar o modo como a obra de Antonio Gramsci foi incorporada por autores marxistas que compõem o debate a respeito da derivação do Estado a partir das categorias da crítica do valor propostas por Karl Marx. Para tanto, o foco será dado ao conceito de “hegemonia” conforme proposto por Gramsci, por entendê-lo como central dentro de sua teoria política. Será abordada a forma como tal conceito foi mobilizado por Joachim Hirsch e Bob Jessop, dois autores que participaram do referido debate e que produziram importantes e antagônicas contribuições para as análises marxistas a respeito da natureza do Estado capitalista.
Considerações sobre a crítica de Blaise Pascal à filosofia moderna do século XVII
Authors: Almeida Rafael Ribeiro de
Published: May 2021

O artigo desenvolvido pretende apresentar Blaise Pascal como antípoda do projeto racionalista de modernidade do século XVII (cujo filósofo emblemático é René Descartes). Ao apontar os limites da razão humana, Pascal contrapõe-se ao otimismo racionalista da sua época, cujo projeto reside em levar o homem, somente via razão, ao conhecimento claro e evidente do mundo. Neste sentido, debruçamo-nos sobre sua refinada obra — Pensamentos —, na qual Pascal posiciona-se de modo a compreender a razão humana como não capaz de afirmar algo de essencial ou verdadeiro, podendo o homem, tão somente, perceber alguma aparência das coisas. Ao cabo, a filosofia pascaliana procura indicar que a proposta de esclarecer o mundo através da racionalidade (supostamente) onipotente revela-se, na verdade, como um modo de escamotear a insuficiência humana.
A Ditadura Militar na Argentina (1976-1983): o aparato repressivo e a Justiça de Transição
Authors: Ribeiro Heloísa Cristina
Published: May 2021

Em 1976, a Argentina sofreu um golpe de Estado orquestrado pelos militares com apoio de setores da sociedade civil, em que é instaurado um regime do terror em defesa dos “valores ocidentais”. Tendo em vista os processos históricos anteriores ao golpe, o presente artigo contextualiza a natureza do regime ditatorial da Argentina e as práticas repressivas, que incluem a tortura, o roubo de bebês e o ocultamento de cadáveres, e apresenta a transição para o regime democrático após 1983. Através de uma comparação entre as bibliografias produzidas sobre a busca por verdade e por justiça na Argentina, busca-se tecer uma análise crítica sobre a Justiça de Transição do país, apresentando as contribuições da experiência argentina para o cenário global, em que a atuação da sociedade civil possui grande importância, e as limitações do processo.
Formas de trabalho “não capitalistas” no capitalismo: sobrevivência histórica ou parte integrante?
Authors: Amador Rodney da Silva
Published: May 2021

O presente artigo tem como objetivo fazer uma pequena contribuição para uma discussão já clássica entre os autores — ditos ou reconhecidos — marxistas, afinal, as chamadas formas não capitalistas de trabalho, isto é, que não são remuneradas na forma de um salário (servidão, escravidão, trabalho voluntário) consiste numa sobrevivência de outros meios de produção ou são parte integrantes do capitalismo? Desta forma, situamos argumentos tanto de um lado da questão quanto de outro, mostrando diferentes vertentes às quais autores marxistas se vinculam. O texto está dividido em três partes: uma breve introdução, uma análise da questão da acumulação primitiva em Marx e, por fim, uma análise de autores que pensaram a questão das formas de trabalho e seus dilemas. Nesta terceira parte, também se levanta certos problemas mais atuais e propostas que levem em consideração debates políticos como a reforma da previdência e a reforma trabalhista.
Rivalidades locais, ambições atlânticas: a diplomacia do comércio de escravos na análise das cartas de Agonglo e Adandozan (1795-1805)
Authors: Gonçalves Raphael dos Santos
Published: May 2021

Neste artigo busco demonstrar as continuidades, rupturas e tensões existentes na diplomacia afro-luso-brasileira no período entre 1795 e 1805, marcos temporais definidos pelo envio de duas embaixadas daomeanas à América Portuguesa. A partir da análise e da comparação entre esses contatos diplomáticos, apresento aspectos que demonstram que as embaixadas são fe-nômenos dotados de historicidade. Amparando-me na análise documental de um conjunto de Cartas do Daomé levantadas por Luis Nicolau Parés, discuto as interações e reciprocidades na diplomacia entre chefaturas daomeanas e autoridades luso-brasileiras durante o período do comércio atlântico de escravos. Busco demonstrar, afinal, que as missivas evidenciam esforços para o estabelecimento de relações comerciais prioritárias com luso-brasileiros, compreensíveis apenas se considerada a imbricação entre as dimensões local e atlântica no Golfo do Benim.