bluuebunny/crossref_metadata_2025 huggingface dataset:
As mulheres no campo político
Authors: Zeytounlian Lauren , Caminhas Lorena Rubia Pereira , Vasco Marcela , Negretti Natália , Ponte Vanessa
Published: April 2021

Neste ensaio investigamos os discursos midiáticos acerca de gênero difundidos em três distintos momentos da política contemporânea brasileira: a eleição e posse da presidenta Dilma Rousseff; o processo de impeachmentinstaurado em dezembro de 2015 e finalizado em agosto de 2016; e o estabelecimento do governo interino de Michel Temer. A análise foi realizada a partir de matérias jornalísticas veiculadas em jornais, revistas e portais onlinedo país no período dos acontecimentos (predominantemente textos da primeira metade de 2016). Complementarmente, analisamos os comentários de internautas relacionados às reportagens. O material estudado revelou que os principais enunciados expressavam uma retomada do espaço doméstico como lugar da mulher e enfatizavam uma incapacidade das mulheres para assumir cargos de relevo na vida pública, constituindo-se como argumentos mobilizados para legitimar o impedimento de Dilma.
O Brasil e a diáspora haitiana
Authors: Bersani Ana Elisa , Joseph Handerson
Published: April 2021

Desde o século XIX, os haitianos circulam entre diferentes espaços nacionais e transnacionais, notadamente no Caribe, na América do Norte, na América do Sul e na Europa, tradicionalmente em países que constituem a diáspora haitiana como os Estados Unidos, o Canadá, a França, a República Dominica e Cuba. Isto é evidência de que a mobilidade é um fenômeno antigo e estrutural no universo haitiano. Entretanto, a partir de 2010, após o terremoto no Haiti, teve início “um quarto grande fluxo da mobilidade internacional haitiana” (JOSEPH, 2015a, 2017a e 2017b) em direção ao Equador, ao Peru, ao Chile, à Argentina, e sobretudo, ao Brasil.
Migração haitiana em São Paulo pós-terremoto de 2010
Authors: Déus Frantz Rousseau
Published: April 2021

O presente artigo investiga o suporte oferecido e o papel desempenhado pela religião na construção de laços afetivos e religiosos que facilitaram a integração social dos imigrantes haitianos na sociedade brasileira de 2012 a 2015. Para alcançar esse objetivo, realizei observação acompanhante no Salão do Reino (Testemunha de Jeová) localizado no Jardim Londres em Campinas. Também, acompanhei várias atividades religiosas feitas pelas Testemunhas de Jeová no Brasil, presencialmente e online. Analisei, ainda, o corpus textual relacionado à questão da religião e da migração; além de outros textos importantes como artigos de jornal, dentre outros. A partir desse estudo, foi possível entender que a religião Testemunhas de Jeová, na tentativa de pregar e converter migrantes haitianos, construiu laços de amizade e de afetividade que facilitam a aceitação dos estudos bíblicos por parte destes imigrantes. Faz parte da própria política de pregação construir tais laços de uma maneira simbólica. Imigrantes com quem conversei durante essa pesquisa mencionaram o apoio que eles recebem dos seguidores dessa religião, como informações acerca do cotidiano da sociedade brasileira e suporte linguístico (ensino de português por alguns membros).
Development of loyalty programmes in the hotel industry
Authors: Laškarin Marina
Published: April 2021

Purpose – In the very beginning when loyalty programmes were being developed, hoteliers were mostly involved as partners of airline companies. However, once they realized the obvious numerous advantages that airlines were gaining, hoteliers began to design their own loyalty programmes. The idea of a loyalty programme is to strike a balance between what guests want and what is offered to them as a reward, and to find other programme partners whose services guests will also use. This paper will look at the basic tenets of loyalty programmes in the hotel industry, the methods of keeping records about guests, and the necessity of creating, structuring and managing guest databases. Design – Four main areas are discussed, namely: loyalty programme, loyalty cards, guest database, and value for guest. The structure of the paper follows this classification. Approach and methodology – The paper is theoretical; it provides review of previous research and gives novel insights into hotel loyalty programme. Various kinds of loyalty programmes are analysed with emphasis placed on loyalty programmes that have emerged based on the differentiation of guests with regard to price policies. This approach is regarded as a considerable contribution to further research into loyalty programmes in the hotel industry. Research findings and originality – While being a major precondition to guest loyalty towards a hospitality facility, guest satisfaction is not the only factor involved. Varying degrees of satisfaction and differing reactions to a specific service create discrepancies between less or more loyal guests regarding the same service or product. Research in this paper focuses on guest loyalty in the hotel industry, that is, on a long-term relationship based on loyalty and trust between a hotel and its guests. The paper’s basic hypothesis is accepted: Well-organized hotel loyalty programmes can help to create an improved approach to guests, from which will result a higher level of satisfaction with services rendered.
Competitiveness of Kvarner region: challenges for destination management and branding
Authors: Bagarić Lidija , Žitinić Danko
Published: April 2021

Purpose – Tourism demand for destinations, services and facilities is changing rapidly and only the destinations with high adaptability can expect to survive. Tourists prefer destinations with strong brands that guarantee a high level of service quality and are prepared to pay for it. Design – This study designs to determine that destination has to recognize the importance of tourism, but, as a brand, Kvarner is not distinctive enough. Based on its natural beauty, rich heritage and its vicinity and accessibility to a large part of Europe, it has the potential of becoming a leading destination. Methodology – Research was carried out in accordance with the Integrated Model of Destination Competitiveness based on 85 indicators. Various statistical methods like T-test, Wilcoxon signed rank test and Shapiro-Wilk test were used. Approach – The research was conducted using a questionnaire, through a dissemination of emails and personal interviews with tourist officials and people involved in the development of tourism in the Kvarner area. Findings – This study finds that destination management is the weak point of destination competitiveness and hypotheses that resources strongly support the overall competitiveness of destination Kvarner, than the elements of destination management and that destination brand is not sufficiently distinctive are confirmed. Originality of the research – This study provides valuable information and comparable data about competitiveness of Kvarner destination and points at brand influence on destination competitiveness.
Parameter Estimation of a Single-Phase Boost PFC Converter with EMI Filter based on an Optimization Algorithm
Authors: Rojas-Dueñas Gabriel , Riba Jordi-Roger , Moreno-Eguilaz Manuel
Published: April 2021

This paper proposes an approach to estimate the parameters of an AC-DC boost power factor corrector converter which includes an EMI filter. To this end, once the topology is known, measurements at the input and output terminals of the converter are done to identify the values of the passive elements. The proposed methodology is based on the trust-region nonlinear least squares algorithm to identify the parameters of the converter. The steady-state and the transient signals of the converter at the input/output terminals are acquired non-intrusively without any internal modification of the circuitry. The accuracy of the parameter identification carried out is determined by comparing the estimated values with the actual values provided by the manufacturer, and by contrasting the measured signals with the ones obtained with a simulation model with the estimated values of the parameters. The results presented in this paper prove the accuracy of the proposed approach, which can be extended to other power converters and filters.
Excision and Reconstruction of Alveolar Rhabdomyosarcoma Involving the Achilles Tendon in a Pediatric Patient
Authors: Koressel Joseph , Stein Matthew , Serra López Viviana M. , Bhatti Tricia R. , Arkader Alexandre
Published: April 2021

Case:

We describe a case of a 9-year-old boy who presented with a left calf mass consistent with alveolar rhabdomyosarcoma involving the Achilles tendon. The patient underwent radical resection of the Achilles tendon and Achilles tendon allograft reconstruction. At 2.5-year follow-up, the child had full ankle range of motion and strength and no signs of disease.

Conclusions:

Radical resection of Achilles tendon in the setting of malignancy and reconstruction with allograft is a rare procedure that has not been previously described in the pediatric population. Orthopaedic oncologists can consider this option for the rare malignancies involving the Achilles tendon.
Hydraulic Fracture Characterization Using Rapid Simulation
Authors: Moridis Nefeli , Lee John , Lam Duc , Schultz Christie , Wardlow Wade
Published: April 2021

The purpose of this paper is to present a technique to estimate hydraulic fracture (HF) length, fracture conductivity, and fracture efficiency using simple and rapid but rigorous reservoir simulation matching of historical production, and where available, pressure. The methodology is particularly appropriate for analysis of horizontal wells with multiple fractures in tight unconventional or unconventional resource plays. In our discussion, we also analyze the differences between the results from decline curve analysis (DCA) approach and the Science Based Forecasting (SBF) results that this work proposes. When we characterize fracture properties with SBF, we can do a better job of forecasting than if we randomly combine fracture properties and reservoir permeability together in a decline-curve trend. The forecasts are significantly different with SBF, therefore fracture characterization plays an important role and SBF uses this characterization to produce different (and better) forecasts.
Turning Produced Water into an Asset: A Delaware Basin Case History
Authors: Aro Dustin , Fowler Steven
Published: April 2021

The Delaware Basin encompasses 6.4 million acres throughout Southeastern New Mexico and West Texas. With large players such as ExxonMobil, Shell or Oxy typically grabbing headlines, it's easy to forget the multitude of smaller public and private E&P operators who exist in and around the acreage positions of the aforementioned companies. Regardless of the size of the acreage holding, a consistent theme is that a typical horizontal well drilled and completed (D&C) will yield water cuts of 60-90% at any given period in its productive lifespan.

Saltwater production, handling and disposal (SWD) is a drag on lease operating expenses (LOE). SWD costs via trucking, pipeline, or on-lease SWD wells can range between $0.50-$3.00/bbl. As existing infrastructure is exhausted, water handling costs have been projected to rise to over $5.00/bbl. Additionally, restricted access to SWD could cause production curtailments and thus impacting operators beyond direct LOE.1

Well completion operations are impacted by freshwater procurement costs starting around $0.75/bbl. Regardless of final frac design, water consumption during fracturing operations typically exceeds 500,000 bbls or $375,000 per well. Significant value exists for recycling produced water via an on-lease pit and utilizing it for future frac operations. The produced water turns into an asset if the operator can efficiently manage to substitute higher and higher percentages of freshwater with produced water.

Many smaller operators (defined as less than 50,000 acres) may view produced water recycling as an operation best left to large E&P's with their massive capital budgets and contiguous acreage. Fortunately, even a 5 well, section development plan can yield returns from an on-lease produced water recycling program.
A Shot in the Dark: How Your Post-Fracture Perforation Imaging can be Misleading and How to Better Understand Cluster Efficiency and Optimize Limited Entry Perforating
Authors: Horton Blake
Published: April 2021

With recent advances in downhole imaging technology, it has become evident that surface perforation testing does not directly translate to downhole conditions. A total of 279 pre- and 595 post- fracture treatment perforations were imaged in this analysis. Pre-treatment perforation hole size was highly variable, even with oriented equal-entry charges. Because of high pre-fracture treatment variability, it is not recommended to use an average diameter of unstimulated perforations to evaluate cluster efficiency of perforations post-fracture treatment. Ideally, perforations should be individually imaged before and after treatment for direct comparison. However, since pre-treatment imaging is costly, an alternate methodology is presented. The findings in this paper will challenge current understanding of actual pre-treatment hole sizes, their variability, and their implications on cluster efficiency.

Cluster efficiency cutoff limits have historically been subjective and promoted a false confidence in the ability of Completions Engineers to extend stage lengths and adjust perforation designs. A more stringent and calculated method of determining cluster efficiency is presented.

Utilizing both wireline pumpdown for pre-treatment measurements, and coil tubing for post-treatment measurements, downhole imaging technology was deployed to measure perforations from four separate perforation charge manufacturers for pre- and post- treatment erosional analysis.

Additionally, while understanding the strike/slip stress state of the Anadarko basin, perforations were oriented at 90° and 270° (degrees from top of wellbore), parallel to the maximum rock stress, promoting a shorter and less tortuous path to the fracture initiation point. Perforating at 90° and 270° reduced tortuosity and surface treating pressure, promoted a less variable pre-treatment perforation hole size due to its symmetry, and resulted in a significant increase in cluster efficiency verses pervious designs.

This project effectively optimized a perforation design utilizing pre- and post- fracture treatment perforation imaging and a thorough understanding of pre-treatment perforation hole size to evaluate the effectiveness of stress-targeted, oriented perforating and its effect on cluster efficiency, tortuosity, and pre-treatment hole size variability. The optimized design resulted in 84%-97% cluster efficiency and reduced surface treating pressure by 770 psi. This workflow can be applied by Completions Engineers to any unconventional basin where plug and perf design is utilized.
Practical Design Considerations for Stage Length, Perforation Clusters and Limited Entry Pressure Intensities
Authors: Huckabee Paul , Ledet Chris , Ugueto Gustavo , Tolle John , Mondal Somnath
Published: April 2021

This paper presents design considerations and field trial applications for determining practical dimensions and limits for interdependencies associated with stage length, perforation clusters and limited entry pressures. Recent applications by multiple authors and companies have begun to reverse the decade-long trend of reducing stage length and perforation spacing, in favor of extending stage lengths, to capture free cash flow value for unconventional resource development. Aggressive limited entry has been an enabler for successful extended stage length applications. Multiple authors have advocated "eXtreme Limited Entry" (XLE) applications. We present diagnostics data and applications that challenges the need for XLE and better constrains the necessary amount of limited entry pressures for effective stimulation distribution for resource development across multiple North American Basins.

Data is presented from integrated application of field trials, stimulation distribution diagnostics, and well performance analysis. Field trials and well performance analysis are from the Permian Delaware Basin Wolfcamp. The field trials include both: greater perforation cluster intensities for base design stage lengths; and extended stage lengths of 50% greater than the base designs. Diagnostics are from multiple North American Basins and include discrete treatment pressure diagnostics and optic fiber distributed sensing. Data is presented to quantify the magnitude and variability for components necessary for maintaining active fracture extension for multiple perforation clusters. Components include: fracture breakdown pressures; in-situ stress, net fracture extension pressure, and near wellbore complexity pressure drop.

Data and examples are presented from multiple wells, and resource development areas, to show the variability in measured treatment pressures for different length scale dimensions. This variability is used to determine the amount of limited entry pressure required to maintain fracture extension, dependent on the stage length dimension. Although Aggressive Limited Entry (ALE) is generally required to enable effective stimulation distribution and extended stage lengths in multiple cluster stages, examples are presented that demonstrate XLE is generally not required. We also discuss some of the considerations and observations that limit perforation cluster spacing intensities. Well performance data from the field trials is presented to validate the applications.

This work demonstrates the value of integrated application of field trials, stimulation distribution diagnostics, and well performance analysis to capture free cash flow value from improved completions and stimulation designs. The discussion will include an assessment of future opportunities for further extension of stage length dimensions.
Modeling Wellbore Proppant Transport and Distribution Across a Single Hydraulic Fracturing Stage Under Field Conditions Using Computational Fluid Dynamics
Authors: Kebert Brent , Almulhim Abdulraof , Miskimins Jennifer , Hunter William , Soehner Gage
Published: April 2021

Successfully treating each cluster within a hydraulic fracturing stage is a key objective for "plug-n-perf" well completions. Most operating companies would agree that the main underlying desire for a successful completion is related to future production capability. In unconventional reservoirs, propped and conductive hydraulic fractures are the primary completion result that drives production and reserve recovery. When designing a treatment, the spacing of clusters is critical to optimizing production and reserve recovery parameters, and therefore, even proppant distribution across a single stage delivers a well the greatest potential for optimized production performance. Diverting the fracturing fluid and proppant evenly across the clusters in a stage allows the greatest opportunity for each cluster to produce equally and drain the associated reservoir volume. Generating equal, producing fractures across a horizontal wellbore is a difficult problem that operators are still trying to solve.

This work models the fluid and proppant distribution across a field-scale, 250-ft long, horizontal hydraulic fracturing stage, replicating realistic field conditions. By utilizing computational fluid dynamics (CFD), this paper investigates the effected proppant distribution results from a fracturing stage mimicking the presence of both a leaking plug and the impacts of stress shadowing. The proppant concentration throughout the wellbore, along with internal wellbore pressure and velocity, are also reviewed to gain an understanding of the effect of the field conditions. Additionally, this paper illustrates the effect of different proppant "ramping" conditions during the fracturing stage. Proppant ramping schedules can be smooth or sharp when increasing proppant concentration, which alters the proppant concentrations throughout the wellbore and associated perforation clusters. Unanticipated alterations of the proppant concentration within the wellbore can lead to early screenouts. Gaining a better understanding of the proppant distribution and concentration inside the wellbore can lead to improved designs of hydraulic fracturing completions.
Application of DFIT-FBA Tests Performed at Multiple Points in a Horizontal Well for Advanced Treatment Stage Design and Reservoir Characterization
Authors: Zeinabady Danial , Zanganeh Behnam , Shahamat Sadeq , Clarkson Christopher R.
Published: April 2021

The DFIT flowback analysis (DFIT-FBA) method, recently developed by the authors, is a new approach for obtaining minimum in-situ stress, reservoir pressure, and well productivity index estimates in a fraction of the time required by conventional DFITs. The goal of this study is to demonstrate the application of DFIT-FBA to hydraulic fracturing design and reservoir characterization by performing tests at multiple points along a horizontal well completed in an unconventional reservoir. Furthermore, new corrections are introduced to the DFIT-FBA method to account for perforation friction, tortuosity, and wellbore unloading during the flowback stage of the test.

The time and cost efficiency associated with the DFIT-FBA method provides an opportunity to conduct multiple field tests without delaying the completion program. Several trials of the new method were performed for this study. These trials demonstrate application of the DFIT-FBA for testing multiple points along the lateral of a horizontal well (toe stage and additional clusters). The operational procedure for each DFIT-FBA test consists of two steps: 1) injection to initiate and propagate a mini hydraulic fracture and 2) flowback of the injected fluid on surface using a variable choke setting on the wellhead. Rate transient analysis methods are then applied to the flowback data to identify flow regimes and estimate closure and reservoir pressure. Flowing material balance analysis is used to estimate the well productivity index for studied reservoir intervals.

Minimum in-situ stress, pore pressure and well productivity index estimates were successfully obtained for all the field trials and validated by comparison against a conventional DFIT. The new corrections for friction and wellbore unloading improved the accuracy of the closure and reservoir pressures by 4%. Furthermore, the results of flowing material balance analysis show that wellbore unloading might cause significant over-estimation of the well productivity index. Considerable variation in well productivity index was observed from the toe stage to the heel stage (along the lateral) for the studied well. This variation has significant implications for hydraulic fracture design optimization, particularly treatment pressures and volumes.
Frac Charge Performance at Downhole Conditions: Assessments and Implications
Authors: Grove Brenden , McGregor Jacob , DeHart Rory , Dusterhoft Ron , Stegent Neil , Grader Avrami
Published: April 2021

Hydraulically fractured completions dominate industry perforating activity, particularly in North American land basins. This has led to the development of fracture-optimized perforating systems in recent years. Aside from overarching safety, reliability, and efficiency priorities, the main technical performance attribute of these systems is consistent hole size in the casing, driven by limited entry fracture design considerations. While the industry continues to seek further improvements in hole size consistency, attention is also being directed to the perforations more holistically, from a perspective of maximizing the effectiveness of subsequent hydraulic fracturing and ultimately production operations.

To this end, this paper presents two related activities addressing the development, qualification, and optimization of perf-for-frac systems. The first is a surface testing protocol used to characterize perforating system performance, in particular casing hole size and consistency. The second is a laboratory program, recently conducted to investigate perforating stressed Eagle Ford shale samples at downhole conditions. This program explored the influences of charge size, formation lamination direction, pore fluid, and dynamic underbalance on perforation characteristics. Casing hole size was also assessed.

For the first activity (surface testing), we find that using cement-backed casing can be an important feature to ensure more downhole-realistic results. For the second activity (laboratory program), perforation casing hole sizes for the charges tested were in line with expectations based on existing surface test data, exhibiting negligible pressure dependency. Corresponding penetration depths into the stressed shale samples generally ranged from 3.5-in to 5-in, which is much shallower than might be expected based on surface concrete performance. Dynamic underbalance was found to exhibit some slight effect on the tunnel fill characteristics, while pore system fluid was found to have minimal influence on the results.

An interesting feature of the perforated samples was the complex fracture network at the perforation tips, which appeared "propped" to some extent with charge liner debris. Some of these fractures were formation beds which had delaminated during the shot, a phenomenon observed for perforations both parallel and perpendicular to the laminations.

The implications of these results to the downhole environment continues to be assessed. Of particular interest is the impact these phenomena might have on fracture initiation, formation breakdown, and treatment stages which accompany subsequent hydraulic fracturing pumping operations.
Characterization and abatement of SOx, NOx and PCDD/Fs in iron ore sinter machine wind legs
Authors: Angalakuditi Veera Brahmacharyulu , Gujare Ramarao , Anbarasu Ramados , Gandikoti Thimmappa , Raydurg Srinivas Rao , Singh Lokendra Raj , Baral Saroj Sundar
Published: April 2021

It was observed that SOx and NOx, in large concentrations, are getting released from certain wind boxes below the sinter machine. The particulates released from specific wind legs were characterized using Quantitative Evaluation of Materials by Scanning Electron Microscopy (QEMSCAN). Particulates with spherical, cubical, needle and bar-like morphologies containing K, Na, Cl were found. Nitrogen-based solids were found in clutter-like morphology. Some particles had a mixture of the above, SOx and NOx. A method of dissolving SOx, NOx and breaking them down into harmless substances was explored in this research. The deposits in the wind legs were dissolved in demineralized water and solutions of sodium bicarbonate, urea, and di-sodium borate deca-hydrate (borax) to estimate the absorbance of K, Na, Cl, Ca, Mg, S, and N based compounds present. Demineralized water and sodium bicarbonate were found to be the most effective sorbents of SOx and NOx. The filtrates were examined under QEMSCAN and found that SOx and NOx are not present. Based on the above finding, a solution of sodium bicarbonate and water 0.01% v/v was sprayed into a wind box and found that SOx and NOx have got reduced by about 55%. To maximize the capture of SOx and NOx, the solution was optimized at 0.02% v/v. With this novel technique, capital intensive Desulphurization (De-SOx) and Denitrification (De-NOx) installation can be avoided. Additionally, an economical solution to the Polychlorinated dibenzo para-dioxins and polychlorinated dibenzofurans (PCDD/Fs) emission was explored in this research. Various physicochemical mechanisms of forming harmful substances are described in this paper.
Magnetically actuated self-clearing catheter for rapid in situ blood clot clearance for improved hemorrhagic stroke treatment
Authors: Yang Qi , Enriquez Angel , Devathasan Dillon , Thompson Craig , Nayee Dillan , Harris Ryan , Satoski Douglas , Obeng-Gyasi Barnabas , Lee Albert , Bentley R. Timothy , Lee Hyowon
Published: April 2021

Maintaining the patency of indwelling drainage devices is critical in preventing further complications following an intraventricular hemorrhage (IVH) and other chronic disease management. Surgeons often use drainage devices to remove blood and cerebrospinal fluid but these catheters frequently become occluded with hematoma. Using an implantable magnetic microactuator, we created a self-clearing catheter that can generate large enough forces to break down obstructive blood clots by applying time-varying magnetic fields. In a blood-circulating model, our self-clearing catheters demonstrated a 7x longer functionality than traditional catheters (211 vs. 27 min) and maintained a low pressure for longer periods (239 vs. 79 min). Using a porcine IVH model, the self-clearing catheters showed a greater survival rate than control catheters (86% vs. 0%) over the course of 6 weeks. The treated animals also had significantly smaller ventricle sizes 1 week after implantation compared to the control animals with traditional catheters. Our results suggest that these magnetic microactuator-embedded smart catheters can expedite the removal of blood from the ventricles and potentially improve the outcomes of critical patients suffering from often deadly IVH.
Soil fertility of fluvial islands increases with proximity to an Amazonian white-water river
Authors: Neto Gilson de Souza Ferreira , BACCARO FABRICIO BEGGIATO , QUESADA CARLOS ALBERTO NOBRE , FIGUEIREDO AXA SIMÕES , OLIVEIRA REGISON , GOMES ERISON , SPIRONELLO WILSON ROBERTO , BARNETT ADRIAN PAUL ASHTON
Published: April 2021

The nutrient content of soils is considered a productivity key factor. Sediment input from Amazonian rivers is one of the natural sources of soil fertility for fluvial islands and riverbank flooded forests. Despite the importance of soil factors for ecosystems, few edaphic studies along riverine sediment-gradients have been undertaken in tropical areas. The current study provides a step forward by describing soil nutrients in a mixed water (sediment-poor black water with input of sediment-rich whitewater) fluvial archipelago. To investigate how geographic distance from a whitewater river mouth affects island soil properties, soil chemical and physical attributes were determined at 61 sampling sites on 35 islands. The studied Central Amazon fluvial islands showed high variability in our fluvisols soil properties. In general, the fluvial island soils were acid and with low fertility. Islands from Jaú and other sites closer to the sediment source (the river Rio Branco) had higher soil fertility than islands of the Anavilhanas Archipelago, which are further away from the sediment source. Our results show that sediment inputs from Amazonian rivers can play an important role in soil properties, and this research increases our understanding on the origin and evolution of one of the largest freshwater archipelagos in the world. Given that soil fertility is often correlated with forest productivity, the main results reported here may also help improve management plans and conservation policies for fluvial island environments of Central Amazonia.
Adaptive vibration control of piezoelectric cantilever beams with uncertainties
Authors: Cui Mingyue , Liu Hongzhao , Jiang Hualong , Qu Chongnian , Liu Wei
Published: April 2021

Considering the stiffness characteristics of piezoelectric layer, the bending stiffness of piezoelectric cantilever beam is obtained by applying the first-order shear deformation theory. The finite element model of piezoelectric cantilever beam is established by Hamilton variation principle. At the maximum strain point, the sensors/actuators are equipped in pairs. Based on the uncertain dynamic model of piezoelectric cantilever beam, an adaptive sliding mode controller (ASMC) is designed by using backstepping technique. The correctness of the finite element model of cantilever beam established is verified by comparing the calculation results of ANSYS software. The effectiveness and superiority of the proposed the ASMC method are verified by the numerical simulations, in comparison with traditional linear quadratic regulator (LQR) control method.
Heat Preconditioning Protects Skin Pressure Injury and Reduces Incidence of Intraoperatively Acquired Pressure Ulcers in Both Humans and Animals
Authors: Xue Huiping , Chang Shuwen , Hou Ping , Xie Ping , Chen Yajie , Wang Yanwei , Miura Daiji , Fan Jianglin , Liang Jingyan , Kitayama Akio , Fang Fang , Yuan Haijuan , Wu Xiaoling , Zhang Xiaolin , Wang Jing , Ding Ning , Zhang Can , Sun Xiuyun , Takashi En
Published: April 2021

To examine the preventive effect of heat preconditioning (HPC) on intraoperatively acquired pressure ulcers (IAPU) in surgical patients and explore the mechanisms of HPC on pressure injury (PI) in rat skin. We generated a skin PI model using hairless rats and treated these rats with HPC. Skin injury size was measured and the expression of heat shock proteins (HSPs) in the skin were examined by real-time RT PCR, Western blotting, and immunohistochemical staining. For human studies, 118 surgical patients were randomly divided into HPC and control groups. We measured sacral skin temperature, sacral pressure and compared the PI prevalence rate. HPC treatment significantly reduced both area(p =0.007, p =0.007, p =0.012) and incidence (p=0.025, p =0.019, p =0.012) of PI in rats on the second, third and fourth days. HSP27 expression was increased in HPC group. Immunohistochemical staining showed that HSP27 was distributed in all types of dermal cells with increase in basal cells. In human studies, HPC treatment increased sacral temperature (p<0.001). The incidence of IAPUs was significantly decreased by 75% in HPC group. HPC can reduce the incidence of PI in both experimental animals and humans. Beneficial effects of HPC were possibly mediated by upregulation of HSP27.
Benefits of Betanin in Rotenone-Induced Parkinson Mice
Authors: Thong-asa Wachiryah , Jedsadavitayakol Sujira , Jutarattananon Suchawalee
Published: April 2021

The present study aimed to investigate betanin’s neuroprotective effect in mice with rotenone-induced Parkinson-like motor dysfunction and neurodegeneration. Forty male ICR mice were divided into 4 groups: Sham-veh, Rot-veh, Rot-Bet100 and Rot-Bet200. Rotenone (Rot) at 2.5 mg/kg/48 h was subcutaneous injected, and betanin (Bet) at 100 and 200 mg/kg/48 h were given alternately with the Rot injections in Rot-Bet groups for 6 weeks. Motor dysfunctions were evaluated weekly using hanging wire and rotarod tests. Malondialdehyde (MDA), reduced glutathione (GSH), catalase (CAT), superoxide dismutase (SOD), neuronal degeneration in the motor cortex (MC), striatum (Str) and substantia nigra par compacta (SNc) were evaluated. The immunohistochemical densities of tyrosine hydroxylase (TH) in Str and in SNc were also measured. We found that rotenone significantly decreased the time to fall in a hanging wire test after the 4th week and after the rotarod test at the 6th week (p<0.05). The percentage of neuronal degeneration in MC, Str and SNc (p<0.05) significantly increased, and the TH density in Str and in SNc (p<0.05) significantly decreased. Betanin at 100 and 200 mg/kg significantly prevented MC, Str and SNc neuronal degeneration (p<0.05) and prevented the decrease of TH density in Str and in SNc (p<0.05). These findings appeared concurrently with improved effects on the time to fall in hanging wire and rotarod tests (p<0.05). Treatment with betanin significantly prevented increased MDA levels and boosted GSH, CAT and SOD activities (p<0.05). Betanin exhibits neuroprotective effects against rotenone-induced Parkinson in mice regarding both motor dysfunction and neurodegeneration. Betanin’s neurohealth benefit relates to its powerful antioxidative property. Therefore, betanin use in neurodegenerative disease therapy is interesting to study.
Disseminated nocardiosis caused by Nocardia vulneris in a macroglobulinemia patient
Authors: QIU Fu lan , MA Zhiyi , ZHONG Rongrong , HUANG Hao nan , WANG Yue Hua , Liu Hui
Published: April 2021

Headings Background : This is a case of a human disseminated nocardiosis caused by Nocardia vulneris which made the patient presenting with fever, cough, shortness of breath, muscle pain and multiple tubercle. Methods: Bacterial culture the blood, sputum, lung rinses and scalp pus samples of the patient, Nocardia vulneris was isolated and identified using the 16s ribosomal RNA gene sequence sequence data. and determine the sensitivity of the isolated bacteria to antibiotics and analysis of the strain's antibiotic treatment. Results: The isolated was identified as Nocardia brasiliensis, which was resistant to ciprofloxacin, but susceptible to amikacin, gentamicin, tobramycin, linezolid, trimethoprim-sulfamethoxazole, amoxicillin/clavulanic, moxifloxacin, ceftriaxone, cefotaxim, imipenem. The patient recovered and his condition remained stable by combinations with linezolid, amikacin and trimethoprim-sulfamethoxazole. Conclusions: This is the first case report of disseminated nocardiosis caused by Nocardia vulneris, and the current case was treated successfully with linezolid, amikacin and trimethoprim-sulfamethoxazole. Clinicians should be aware of its diagnostic, and the MIC value of the drug sensitivity test should be concerned when there is a wide choice of medicines, for the disseminated cases which are diagnosed definitely should be treated with at least 12 months of antimicrobial therapy, bacteriological examination and antimicrobial susceptibility testing should be performed repeatedly.
Significant Risk Factors Associated With Stunting for Children Under the Age of 5-years in Malawi: the Application of Proportional Odds Model Using DHS Datasets.
Authors: Magagula Mzwakhe , Ramroop Shaun , Habyarimana Faustin
Published: April 2021

BackgroundChild malnutrition is perhaps the one of the main medical condition influencing general human wellbeing, mainly in non-industrial nations. The improvement of legitimate evaluations of malnutrition is one of the difficulties encountered by policymakers in numerous countries worldwide. In this manner, the current study was embraced with the essential goal of evaluating and determining all potential determinants of childhood malnutrition in Malawi, using the Demographic and Health Survey (DHS) data 2015/16. The study seeks to reveal some of the significant factors that are perpetuating the incidence of malnutrition in children of Malawi. It also designed to offer deeper insights on how the probability of being diagnosed with this medical condition (malnutrition) evolves across the different levels of the found significant factors.Methods The proportional odds (PO) model was the best model to utilize, motivated by the design of the current study's data set. The PO model is an alternative to conceptualize how the ordinal designed data can be sequentially into dichotomous groups without losing the ordinal nature of response variables. The model is an extension of logistic regression models with two outcomes, it is one of the best models to deal with ordinal response variable comprising of more than two categories. The PO model, as well as the logistic regression models are common classes of generalised linear models (GLMs) mostly used to model association between dependent variable and independent variables. ResultsThe observations derived from fitting the PO model on the Malawi DHS data to investigate risk factors associated with malnutrition (stunting) suggested that: the age of the child; birth type (singleton/multiple births), parents' level of education, household's type of resident; mother's age at the time of birth, mother's BMI, incident of diarrhoea in the last two weeks before the survey, are the most significant independent risk factors of malnutrition (stunting). ConclusionsAll the aforementioned risk factors are controllable, and they can be improved through intervention strategies. The policies that undergird the country are required to counteract this condition, as the majority of the risk factors need the coherent actions of several governing authorities.
The use of complementary/alternative medicine among paediatric patients
Authors: Myrup Christina , Madsen Hanne , Barkholt Natalia Krantz , Sander Stine Dydensborg , Hoest Arne
Published: April 2021

The use of complementary and alternative medicine (CAM) is increasing. The aim of this study was to characterise the use of CAM among patients in an outpatient clinic in a paediatric department. All patients aged 0–18 years, attending the paediatric outpatient clinic at Hans Christian Andersen Children’s Hospital during a 2-week period, in the autumn of 2020, were asked to participate. In total, 771 patients (83.2%) participated. Data were collected using a structured questionnaire, which consisted of 12 questions. CAM was divided into three groups: Herbal medicine (herbal drugs or dietary supplements) (HM), alternative therapy (AT) (e.g. acupuncture) and chiropractic (CHI). Of the 771 paediatric patients enrolled in this study, 59% (n = 455) had used complementary and alternative medicine at least once. CHI was the most used type of CAM and is especially used for disorders not usually treated with conventional medicine, such as infantile colic. Conclusion: The prevalence of children using CAM in Denmark is high and increasing, compared to previous studies. Paediatricians should be aware of this, and paediatric patients should be interviewed about their use of CAM with regard to side-effects, interactions or lack of compliance with conventional medicine.
SRC activation skews cell fate from apoptosis to senescence
Authors: Anerillas Carlos , Herman Allison , Rossi Martina , Munk Rachel , Lehrmann Elin , Martindale Jennifer , Cui Chang-Yi , Abdelmohsen Kotb , De Supriyo , Gorospe Myriam
Published: April 2021

Cells responding to DNA damage implement complex adaptive programs that often culminate in two distinct outcomes: apoptosis or senescence. To systematically identify factors driving each response, we analyzed human IMR-90 fibroblasts exposed to increasing doses of the genotoxin etoposide and identified SRC as a key kinase contributing to this dichotomous decision. SRC was activated by low (50 μM) etoposide but not by high (200 μM) etoposide levels. With low DNA damage, SRC-mediated activation of p38 critically promoted cell survival and senescence, and increased pro-survival BCL2L2 levels, while SRC-mediated repression of p53 prevented a rise in pro-apoptotic PUMA levels. With high DNA damage, SRC was not activated, leading to elevation of p53, inhibition of p38, and apoptosis. In mice exposed to DNA damage, pharmacologic inhibition of SRC prevented tissue accumulation of senescent cells. We propose that inhibiting SRC could be exploited to induce senescent-cell apoptosis in tissues to improve health outcomes.
Genome wide identification and functional characterization of the cotton C-repeat binding factor (CBF) under cold stress condition
Authors: Liu Jiangna , Magwanga Richard , Xu Yanchao , Wei Tingting , Zheng Jie , Hou Yuqing , Wang Yuhong , Okuto Erick , Agong Stephen Gaya , Wang Kunbo , Zhou Zhongli , Cai Xiaoyan , Liu Fang
Published: April 2021

Background Low temperature is a common biological abiotic stress in major cotton growing areas. Cold stress significantly affects the growth, yield and yield quality of cotton. Therefore, it is important to develop a more robust and cold stress tolerant cotton germplasms. In response to climate change and erratic conditions, plants have evolved various survival mechanisms, one of which induction of various stress responsive transcription factors, such as the C-repeat binding factors (CBFs), which have been found to enhance cold tolerance in various plants. Results In this study detailed evaluation of the cotton CBF has been carried out. A total of 29, 28, 25, 21, 30, 26 and 15 proteins encoded by the CBF genes were identified in Gossypium herbaceum, Gossypium arboreum, Gossypium thurberi, Gossypium raimondii, Gossypium turneri, Gossypium longicalyx and Gossypium australe, respectively. Phylogenetic evaluation revealed that the proteins were grouped into seven clades, with clade 1 and 6 being the largest. Moreover, majority of the proteins encoded by the genes were predicted to be located within the nucleus, while some were distributed in other parts of the cell. Based on the transcriptome and RT-qPCR analysis, Gthu17439 (GthCBF4) was highly upregulated under cold stress, and was further validated through forward genetics. The Gthu17439 (GthCBF4) overexpressed plants showed a significantly tolerance to cold stress, with higher germination rate, higher root growth and high induction levels of stress responsive genes. The over-expressed plants exhibited low level of oxidative damage, due to significant reduction in the H2O2 production. Conclusion The results showed that the Gthu17439 (GthCBF4) could be playing a significant role in enhancing cold stress tolerance in cotton and can be further exploited in developing cotton germplasm with an improved cold-stress tolerance
Rhythmic Sensory Stimulation on Gait in Patients With Chronic Stroke
Authors: Lee Yungon , Shin Sunghoon
Published: April 2021

Background: Patients with stroke suffer from impaired locomotion which exhibit unstable walking with increased gait variability. Rhythmic sensory stimulation is one approach for improving the gait of persons with stroke, Parkinson’s disease, or the elderly. However, the effects of this approach on the gait of patients with chronic stroke are unclear. This study was conducted to identify the effects of rhythmic sensory stimulation on the gait of patients with chronic stroke. Methods: Twenty 20 older adults with stroke (mean age ± SD, 72.10 ± 7.15 years; female/male, 8/12) and twenty age- and gender-matched healthy controls (mean age ± SD, 72.65 ± 6.93 years; female/male, 8/12) walked 60 m under four conditions: (1) normal walking with no stimulation, (2) walking with rhythmic auditory stimulation (RAS), (3) walking with rhythmic somatosensory stimulation (RSS), and (4) walking with rhythmic combined stimulation (RCS: RAS + RSS). RAS was applied through an earphone in the ear of each participant, while RSS was applied through a haptic device on the wrist of the participant. RCS was applied simultaneously via an earphone and haptic device. The gait performance (i.e., mean gait speed, stride length, gait cycle, cadence, stance ratio, swing ratio, and double support ratio) and gait variability (i.e., coefficient of variation (CV) value of stride length, gait cycle, stance ratio, swing ratio, and double support ratio) were evaluated. Results: Gait performance in the stroke group was significantly improved in walking with RAS, RSS, and RCS compared to normal walking with no stimulation (P < 0.008). Gait variability was significantly decreased in the RAS, RSS, and RCS conditions compared to that during normal walking (P < 0.008). The gait performance and variability in the healthy control group were not significantly different under the RAS, RSS, or RCS conditions compared to those under normal walking (P > 0.008). Conclusions: Rhythmic sensory stimulation is effective in improving the gait of patients with chronic stroke, regardless of the type of rhythmic stimuli, compared to healthy controls. Trial registration: This study was approved by the Bioethics Committee (IRB-2019-04-003-001), and all participants provided written informed consent.