bluuebunny/crossref_metadata_2025 huggingface dataset:
Are there sex differences among colorectal cancer patients in treatment and survival? A Swiss cohort study
Authors: Limam Manuela , Matthes Katarina Luise , Pestoni Giulia , Michalopoulou Eleftheria , Held Leonhard , Dehler Silvia , Korol Dimitri , Rohrmann Sabine
Published: March 2021

Background

Colorectal cancer (CRC) is among the three most common incident cancers and causes of cancer death in Switzerland for both men and women. To promote aspects of gender medicine, we examined differences in treatment decision and survival by sex in CRC patients diagnosed 2000 and 2001 in the canton of Zurich, Switzerland.

Methods

Characteristics assessed of 1076 CRC patients were sex, tumor subsite, age at diagnosis, tumor stage, primary treatment option and comorbidity rated by the Charlson Comorbidity Index (CCI). Missing data for stage and comorbidities were completed using multivariate imputation by chained equations. We estimated the probability of receiving surgery versus another primary treatment using multivariable binomial logistic regression models. Univariable and multivariable Cox proportional hazards regression models were used for survival analysis.

Results

Females were older at diagnosis and had less comorbidities than men. There was no difference with respect to treatment decisions between men and women. The probability of receiving a primary treatment other than surgery was nearly twice as high in patients with the highest comorbidity index, CCI 2+, compared with patients without comorbidities. This effect was significantly stronger in women than in men (p-interaction = 0.010). Survival decreased with higher CCI, tumor stage and age in all CRC patients. Sex had no impact on survival.

Conclusion

The probability of receiving any primary treatment and survival were independent of sex. However, female CRC patients with the highest CCI appeared more likely to receive other therapy than surgery compared to their male counterparts.
Emerging role and therapeutic application of exosome in hepatitis virus infection and associated diseases
Authors: Shi Ying , Du Lingyao , Lv Duoduo , Li Yan , Zhang Zilong , Huang Xiaolun , Tang Hong
Published: March 2021

Hepatitis viruses are chief pathogens of hepatitis and end-stage liver diseases. Their replication and related pathogenic process highly rely on the host micro-environment and multiple cellular elements, including exosomes. Representing with a sort of cell-derived vesicle structure, exosomes were considered to be dispensable cellular components, even wastes. Along with advancing investigation, a specific profile of exosome in driving hepatitis viruses’ infection and hepatic disease progression is revealed. Exosomes greatly affect the pathogenesis of hepatitis viruses by mediating their replication and modulating the host immune responses. The characteristics of host exosomes are markedly changed after infection with hepatitis viruses. Exosomes released from hepatitis virus-infected cells can carry viral nucleic or protein components, thereby acting as an effective subterfuge for hepatitis viruses by participating in viral transportation and immune escape. On the contrary, immune cell-derived exosomes contribute toward the innate antiviral immune defense and virus eradication. There is growing evidence supporting the application of exosomal biomarkers for predicting disease progress or therapeutic outcome, while exosomal nanoshuttles are regarded as promising therapeutic options based on their delivery properties and immune compatibility. In this review, we summarize the biogenesis and secretion mechanism of exosomes, review the recent findings pertaining to the role of exosomes in the interplay between hepatitis viruses and innate immune responses, and conclude their potential in further therapeutic application.
Lubricating properties of chewing stimulated whole saliva from patients suffering from xerostomia
Authors: Vinke Jeroen , Oude Elberink Marijn , Stokman Monique A. , Kroese Frans G. M. , Nazmi Kamran , Bikker Floris J. , van der Mei Henny C. , Vissink Arjan , Sharma Prashant K.
Published: March 2021

Objectives

The study aimed to quantify the lubricating properties of chewing stimulated whole saliva from healthy controls (n = 22), from patients suffering from primary Sjögren’s syndrome (n = 37) and from patients undergoing head-and-neck radiotherapy (n = 34).

Materials and methods

All participants had to complete the Xerostomia Inventory questionnaire to score dry mouth sensation. Lubrication was measured using an ex vivo tongue-enamel friction system in terms of Relief and Relief period. MUC5b and total protein concentrations of the saliva samples were measured by an enzyme-linked immunosorbent assay and a bicinchoninic acid assay, respectively.

Results

Relief of Sjögren’s patients’ saliva and post-irradiation patients’ saliva was similar compared with healthy controls, but saliva from post-irradiation patients lubricated significantly better than saliva from Sjögren’s patients. The Relief period was similar between the three groups. The Relief and Relief period were higher for saliva samples post-irradiation compared to pre-irradiation. MUC5b and total protein concentrations were comparable in all groups. MUC5b and total protein output were significantly lower in patients subjected to radiotherapy compared to saliva from healthy controls and pre-irradiation patients. MUC5b concentrations positively correlated with lubricating properties of post-irradiation patient saliva.

Conclusions

The lubricating properties of patient saliva were not any worse than healthy controls. Lower flow rate leads to lower availability of saliva in the oral cavity and decreases the overall output of protein and MUC5b, which might result in an insufficient replenishing of the mucosal salivary film.

Clinical relevance

An insufficient replenishing might underlie the sensation of a dry mouth and loss of oral function.
Prognostic and predictive impact of stroma cells defined by PDGFRb expression in early breast cancer: results from the randomized SweBCG91RT trial
Authors: Strell Carina , Stenmark Tullberg Axel , Jetne Edelmann Reidunn , Akslen Lars Andreas , Malmström Per , Fernö Mårten , Holmberg Erik , Östman Arne , Karlsson Per
Published: March 2021

Purpose

Predictive biomarkers are needed to aid the individualization of radiotherapy (RT) in breast cancer. Cancer-associated fibroblasts have been implicated in tumor radioresistance and can be identified by platelet-derived growth factor receptor-beta (PDGFRb). This study aims to analyze how PDGFRb expression affects RT benefit in a large randomized RT trial.

Methods

PDGFRb was assessed by immunohistochemistry on tissue microarrays from 989 tumors of the SweBCG91RT trial, which enrolled lymph node-negative, stage I/IIA breast cancer patients randomized to RT after breast-conserving surgery. Outcomes were analyzed at 10 years for ipsilateral breast tumor recurrence (IBTR) and any recurrence and 15 years for breast cancer specific death (BCSD).

Results

PDGFRb expression correlated with estrogen receptor negativity and younger age. An increased risk for any recurrence was noted in univariable analysis for the medium (HR 1.58, CI 95% 1.11–2.23, p = 0.011) or PDGFRb high group (1.49, 1.06–2.10, p = 0.021) compared to the low group. No differences in IBTR or BCSD risk were detected. RT benefit regarding IBTR risk was significant in the PDGFRb low (0.29, 0.12–0.67, p = 0.004) and medium (0.31, 0.16–0.59, p < 0.001) groups but not the PDGFRb high group (0.64, 0.36–1.11, p = 0.110) in multivariable analysis. Likewise, risk reduction for any recurrence was less pronounced in the PDGFRb high group. No significant interaction between RT and PDGFRb-score could be detected.

Conclusion

A higher PDGFRb-score conferred an increased risk of any recurrence, which partly can be explained by its association with estrogen receptor negativity and young age. Reduced RT benefit was noted among patients with high PDGFRb, however without significant interaction.
New DTW Windows Type for Forward- and Backward-Lookingness Examination. Application for Inflation Expectation
Authors: Rutkowska Aleksandra , Szyszko Magdalena
Published: March 2021

This study provides an application of dynamic time warping algorithm with a new window constraint to assess consumer expectations’ information content regarding current and future inflation. Our study’s contribution is the novel application of DTW for testing expectations’ forward-lookingness. Additionally, we modify the algorithm to adjust it for a specific question on the information content of our data. The DTW overcomes constraints of the standard tool that examines forward-lookingness: DTW does not impose assumptions on time series properties. In empirical study we cover seven European counties and compare the DTW outcomes with the results of previous studies in these economies using a standard methodology. The research period covers 2001 to mid-2018. Application of DTW provides information on the degree of expectations’ forward-lookingness. The result, after standardization, are similar to the standard parameters of hybrid specification of expectations. Moreover, the rankings of most forward-looking consumers are replicated. Our results confirm the economic intuition, and they do not contradict previous studies.
Manin Involutions for Elliptic Pencils and Discrete Integrable Systems
Authors: Petrera Matteo , Suris Yuri B. , Wei Kangning , Zander René
Published: March 2021

We contribute to the algebraic-geometric study of discrete integrable systems generated by planar birational maps: (a) we find geometric description of Manin involutions for elliptic pencils consisting of curves of higher degree, birationally equivalent to cubic pencils (Halphen pencils of index 1), and (b) we characterize special geometry of base points ensuring that certain compositions of Manin involutions are integrable maps of low degree (quadratic Cremona maps). In particular, we identify some integrable Kahan discretizations as compositions of Manin involutions for elliptic pencils of higher degree.
A microbiome engineering framework to evaluate rhizobial symbionts of legumes
Authors: Quides Kenjiro W. , Atamian Hagop S.
Published: March 2021

Background

For well over a century, rhizobia have been recognized as effective biofertilizer options for legume crops. This has led to the widespread use of rhizobial inoculants in agricultural systems, but a recurring issue has emerged: applied rhizobia struggle to provide growth benefits to legume crops. This has largely been attributed to the presence of soil rhizobia and has been termed the ‘rhizobial competition problem.’

Scope

Microbiome engineering has emerged as a methodology to circumvent the rhizobial competition problem by creating legume microbiomes that do not require exogenous rhizobia. However, we highlight an alternative implementation of microbiome engineering that focuses on untangling the complexities of the symbiosis that contribute to the rhizobial competition problem. We outline three approaches that use different starting inocula to test hypotheses to overcome the rhizobial competition problem.

Conclusions

The approaches we suggest are targeted at various stages of the legume-rhizobium symbiosis and will help us uncover underlying molecular mechanisms that contribute to the rhizobial competition problem. We conclude with an integrative perspective of these different approaches and suggest a path forward for future research on legumes and their complex microbiome.
A touchstone of Finnish curriculum thought and core curriculum for basic education: Reviewing the current situation and imagining the future
Authors: Hakala Liisa , Kujala Tiina
Published: March 2021

Pandemics, like other global challenges, are unquestionably curricular issues. They are curriculum issues not only because of the disrupting consequences of Covid-19 and the economic and social crisis alike but also because people have, through their own activities, contributed to global catastrophes and perpetuated injustices. This article attempts to answer the question: How does Finnish curricular thought, including the role of the teacher and the core curriculum for basic education, respond to the various global crises? While reviewing the current situation, the article also imagines a post–Covid-19 curriculum. Reactivating what is still powerful inBildung/Didaktikand emphasizing the importance of education’s ethical dimension and the teacher’s role as a curriculum theorist offer the means for dealing with the theme. In addition, understanding the structure of the National Core Curriculum document, the political dimension of the Finnish curriculum’s design process, and the educative possibilities in subjects and multidisciplinary modules, the teacher is capable of creating opportunities for educational experiences that are (ethically) significant for students, proactively and in terms of crises.
COVID-19 nationwide lockdown and physical activity profiles among North-western Italian population using the International Physical Activity Questionnaire (IPAQ)
Authors: Abate Daga Federico , Agostino Samuel , Peretti Serenella , Beratto Luca
Published: March 2021

Background

The role of physical activity in enhancing health is well recognized. However, in the more industrialized countries, physical activity rates are declining, and the emerging COVID-19 pandemic may amplify this scenario. Thus, this study aimed to report the Italian population’s physical activity profile living in the North-western regions during the national lockdown.

Methods

Physical activity was assessed using the official Italian short form of IPAQ, intended for Social Networking Services (SNS). Participation was voluntary, and people could fill the questionnaire simply by clicking on a specific link.

Results

The final sample size was 612 Italians, male and female, equally distributed (49.1% male and 50.9% female). Data showed a percentage of 15.4% of inactive subjects (MET < 700), 61.8% of moderate-active (MET 700–2500), and 22.9% of active people (MET > 2500). Women were more inactive than men (p < 0.01; 57.4% vs 42.6%). Furthermore, participants were classified into four classes of age: 18–29; 30–44; 45–59; and 60–79. Class 18–29 was prevalent (p < 0.01, 68.3%) and showed higher levels of physical activity (p < 0.05).

Conclusions

Italians living in North-western regions maintained a moderate amount of physical activity during the quarantine. This behavior should be encouraged, particularly among women that usually appear to be less active than men.
Diagnosis and management of X-linked hypophosphatemia in children and adolescent in the Gulf Cooperation Council countries
Authors: Al Juraibah Fahad , Al Amiri Elham , Al Dubayee Mohammed , Al Jubeh Jamal , Al Kandari Hessa , Al Sagheir Afaf , Al Shaikh Adnan , Beshyah Salem A. , Deeb Asma , Habeb Abdelhadi , Mustafa Manal , Zidan Hanaa , Mughal M. Zulf
Published: March 2021

Introduction

X-linked hypophosphatemia (XLH) is a rare inherited cause of hypophosphatemic rickets and osteomalacia. It is caused by mutations in the phosphate-regulating endopeptidase homolog, X-linked (PHEX). This results in increased plasma fibroblast growth factor-23 (FGF23), which leads to loss of renal sodium-phosphate co-transporter expression leading to chronic renal phosphate excretion. It also leads to low serum 1,25-dihydroxyvitamin D (1,25(OH)2D), resulting in impaired intestinal phosphate absorption. Chronic hypophosphatemia in XLH leads to impaired endochondral mineralization of the growth plates of long bones with bony deformities. XLH in children and adolescents also causes impaired growth, myopathy, bone pain, and dental abscesses. XLH is the most frequent inherited cause of phosphopenic rickets/osteomalacia. Hypophosphatemia is also found in calcipenic rickets/osteomalacia as a result of secondary hyperparathyroidism. Thus, chronic hypophosphatemia is a common etiologic factor in all types of rickets.

Results

There is considerable overlap between symptoms and signs of phosphopenic and calcipenic rickets/osteomalacia. Wrong diagnosis leads to inappropriate treatment of rickets/osteomalacia. Nutritional rickets and osteomalacia are common in the Gulf Cooperation Council countries which include Saudi Arabia, United Arab Emirates, Kuwait, Qatar, Bahrain, and Oman. Due to high levels of consanguinity in the region, genetic causes of phosphopenic and calcipenic rickets/osteomalacia are also common.

Conclusion

This guideline was developed to provide an approach to the diagnosis of XLH, especially where there is no family history of the disease, and that other related conditions are not mistaken for XLH. We also guide the medical management of XLH with conventional treatment and with burosumab, a recombinant human IgG1 monoclonal antibody to FGF23.
The Influence of Induction Sintering on Microstructure and Deformation Behavior of Ti-5Al-5Mo-5V-3Cr Alloy
Authors: Zyguła Krystian , Wojtaszek Marek , Śleboda Tomasz , Lech Sebastian , Lypchanskyi Oleksandr , Korpała Grzegorz , Prahl Ulrich
Published: March 2021

The influence of the induction sintering process at different temperatures on the behavior of the powder metallurgy Ti-5Al-5Mo-5V-3Cr alloy was investigated. Material for the research was produced by elemental powder blending, followed by the uniaxial cold compacting process. Powder compacts were induction heated and sintered within the temperature range of 1000 °C to 1300 °C. The influences of process parameters on the material behavior during sintering and its properties were studied. The microstructure examination was performed with particular attention to the pore size and distribution as well as the homogenization of the microstructure. The sintering temperature of 1200 °C proved to be critical for the dissolution of most alloying powder particles. Hot compression tests were performed to determine the formability of the obtained material. Significant differences in flow stress behavior between samples sintered at temperatures below and above 1200 °C were observed. The mechanical properties of the material before and after deformation were compared. The evolution of the microstructure of sintered Ti-5Al-5Mo-5V-3Cr alloy after hot deformation was analyzed with an emphasis on its influence on the material properties. Based on the conducted research, it was found that the adequate homogenization of the chemical composition and microstructure was achieved at the temperature of 1250 °C, and a further increase did not reflect in a significant improvement.
High detection rate in [18F]PSMA-1007 PET: interim results focusing on biochemical recurrence in prostate cancer patients
Authors: Watabe Tadashi , Uemura Motohide , Soeda Fumihiko , Naka Sadahiro , Ujike Takeshi , Hatano Koji , Sasaki Hidetaka , Kamiya Takashi , Shimosegawa Eku , Kato Hiroki , Cardinale Jens , Tateishi Ukihide , Nonomura Norio , Giesel Frederik L.
Published: March 2021

Objective

18F-labeled prostate-specific membrane antigen (PSMA) ligand, [18F]PSMA-1007, has the benefit of a higher synthetic yield and minimal excretion in the urine. High detection efficacy was reported in biochemical recurrence (BCR) of prostate cancer after radical prostatectomy. Thus, we evaluated the preliminary diagnostic utility of [18F]PSMA-1007 PET in patients with prostate cancer, focusing on the BCR which is not detected on conventional imaging.

Methods

We enrolled a total of 28 patients (age 51–79 years) with BCR of prostate cancer. BCR was defined as a continuous increase in PSA after radical prostatectomy or radiation therapy without any apparent recurrent lesions on conventional diagnostic imaging (CT and bone scintigraphy). PSMA-PET scanning was performed approximately 60 min after intravenous injection of [18F]PSMA-1007 (259 ± 37 MBq). PSMA-PET images were evaluated for lesion detection as well as its relation to PSA values and location.

Results

Abnormal uptake, which was suspected to be recurrence or metastasis, was detected in 92.9% (26/28) of patients with BCR. The SUVmax was 8.4 ± 6.4 in local recurrence, 11.5 ± 11.8 in pelvic lymph nodes (LN), and 4.1 ± 1.6 in bone metastasis. The detection rates were 66.7% in the PSA group-1 (0.1–0.5 ng/mL), 85.7% in the PSA group-2 (0.5–1.0 ng/mL), and 100% in the PSA group-3 (above 1.0 ng/mL). Among the PET-positive BCR patients (n = 26), local recurrence was detected in 57.7% (15/26), pelvic LN in 42.3% (11/26), and bone metastasis in 15.4% (4/26). In 53% (8/15) of BCR patients who were suspected of local recurrence, focal uptake was detected adjacent to the bladder on [18F]PSMA-1007 PET. This suggested the significant advantage of having minimal physiological urine excretion.

Conclusions

[18F]PSMA-1007 PET showed a high detection rate in recurrent and metastatic lesions. In patients with BCR, its high detection led to suitable treatment strategies, such as salvage radiation therapy or surgical removal of recurrent lymph nodes.

Trial registration

(UMIN Clinical Trials Registry) UMIN000037697.
Upper Ordovician (Hirnantian) to Lower Silurian (Telychian, Llandovery) graptolite biostratigraphy of the Tielugou section, Shennongjia anticline, Hubei Province, China
Authors: Maletz Jörg , Wang Chuanshang , Kai Wei , Wang Xiaofeng
Published: March 2021

The Tielugou section, Shennongjia Anticline, Hubei Province (China) includes a relatively complete succession of Hirnantian (latest Ordovician) to basal Telychian (Llandovery, early Silurian) graptolite faunas. The section shows the first record of a fauna of the late AeronianStimulograptus halliBiozone from South China, even though the index species was not reported. TheStimulograptus sedgwickiiBiozone may not be represented, indicating a possible gap at the base of theStimulograptus halliBiozone. The interval yields a number of taxa that are elsewhere reported to originate only in theStimulograptus halliBiozone. The youngest graptolitic levels are included in theSpirograptus guerichiBiozone based on specimens ofParapetalolithus dignusandParapetalolithus palmeusnot known from earlier intervals.Spirograptus guerichiis not represented in the section. The Tielugou section provides the first detailed information on the faunas and thickness of the encountered biostratigraphic units for the Shennongija region.
Patient Preferences in Rare Diseases: A Qualitative Study in Neuromuscular Disorders to Inform a Quantitative Preference Study
Authors: Jimenez-Moreno A. Cecilia , van Overbeeke Eline , Pinto Cathy Anne , Smith Ian , Sharpe Jenny , Ormrod James , Whichello Chiara , de Bekker-Grob Esther W. , Bullok Kristin , Levitan Bennett , Huys Isabelle , de Wit G. Ardine , Gorman Grainne
Published: March 2021

Introduction

It has become increasingly important to include patient preference information in decision-making processes for drug development. As neuromuscular disorders represent multisystem, debilitating, and progressive rare diseases with few treatment options, this study aimed to explore unmet health care needs and patient treatment preferences for two neuromuscular disorders, myotonic dystrophy type 1 (DM1) and mitochondrial myopathies (MM) to inform early stages of drug development.

Methods

Fifteen semi-structured interviews and five focus group discussions (FGDs) were held with DM1 and MM adult patients and caregivers. Topics discussed included (1) reasons for study participation; (2) disease signs/symptoms and their impact on daily lives; (3) top desired benefits; and (4) acceptability of risks and tolerance levels for a hypothetical new treatment. Data were analyzed following a thematic ‘code’ approach.

Results

A total of 52 participants representing a wide range of disease severities participated. ‘Muscle strength’ and ‘energy and endurance’ were the disease-related unmet needs most often mentioned. Additionally, improved ‘balance’, ‘cognition’ and ‘gut function’ were the top desired treatment benefits, while ‘damage to the liver, kidneys or eyes’ was the most concerning risk. Factors influencing their tolerance to risks related to previously having experienced the risk and differentiation between permanent and temporary risks. A few differences were elicited between patients and caregivers.

Conclusions

This qualitative study provided an open forum to elicit treatment-desired benefits and acceptable risks to be established by patients themselves. These findings can inform decisions for developing new treatments and the design of clinical trials for DM1 and MM.
Seismic performance of deep excavation restrained by guardian truss structures system using quasi-static approach
Authors: Maleki Mahdi , Nabizadeh Ali
Published: March 2021

The control of deformation and stability of the deep excavation walls under seismic and static loads is one of the most important issues in geotechnical engineering. Therefore, in the present study, using the finite element method and taking into account Hardening soil's behavioural model, the effect of different parameters affecting the performance of the deep excavation walls with the guardian truss structures using quasi-static analysis and its comparison with static analysis has been performed. According to the most important results, increasing in the geotechnical parameters of soil such as cohesion, friction angle and elastic modulus will reduce the maximum horizontal displacement in the vertical trench wall. Besides, the maximum settling in the adjacent ground and the maximum swelling in the bottom of the excavation will be reduced. In this way, the improvement in soil resistance parameters will increase the safety factor. Conversely, by increasing the horizontal distance between the trusses, the maximum horizontal displacement and the maximum settling in the adjacent ground and the maximum swelling in the bottom of the excavation will increase and the safety factor will be reduced. Also, the findings from this research show that by increasing the horizontal seismic acceleration coefficient (Kh) and as the construction stages progress, the maximum horizontal displacement of the wall, the maximum settling of the adjacent ground of the wall and the maximum swelling on the bottom of the trench increase and the safety factor will decrease. As well as, the results obtained from the quasi-static seismic analysis of the vertical trench restrained by the guardian truss structure such as the maximum horizontal displacement of the vertical trench wall and the maximum settling in the adjacent ground and the maximum swelling of the bottom of the excavation are much more than the static analysis.
Study and design of a retrofitted smart water meter solution with energy harvesting integration
Authors: Pimenta Nelson , Chaves Paulo
Published: March 2021

The reduction of water resources due to climate change and the increasing demand associated with population growth is a renewed concern. Water distribution monitoring and smart metering are essential tools to improve distribution efficiency. This paper reports on the study, design, and implementation of a smart water meter (SWM) prototype, designed for mechanical water meters that need to undergo a retrofitting process to enable automatic metering readings. Metering data is transmitted through innovative narrowband internet of things (NB-IoT) technology with low power, long-range, and effective penetration. A flexible power management design allows the introduction of an energy harvester that recovers energy from the surrounding environment and charges the internal battery. The energy harvesting feasibility was demonstrated with two proof-of-concept configurations, light and water-turbine based. The details on the performance of the proposed solution are presented, including the output voltages and harvested power. Although the energy harvesting technologies have not been integrated yet in commercial SWM applications, the results show that the integration is feasible and, once employed in a controlled environment, it can create business advantages by reducing the size and capacity of the internal batteries, enabling one to reduce the operation cost and mitigate long-term ecological problems associated with the use and disposal of batteries.
Conceptual design and numerical studies of active flow control aerofoil based on shape-memory alloy and macro fibre composites
Authors: Zhang W. , Nie X.T. , Gao X.Y. , Chen W.H.
Published: March 2021

Active flow control for aerofoils has been proven to be an effective way to improve the aerodynamic performance of aircraft. A conceptual hybrid design with surfaces embedded with Shape-Memory Alloy (SMA) and trailing Macro Fibre Composites (MFC) is proposed to implement active flow control for aerofoils. A Computational Fluid Dynamics (CFD) model has been built to explore the feasibility and potential performance of the proposed conceptual hybrid design. Accordingly, numerical analysis is carried out to investigate the unsteady flow characteristics by dynamic morphing rather than using classical static simulations and complicated coupling. The results show that camber growth by SMA action could cause an evident rise of Cl and Cd in the take-off/landing phases when the Angle-of-Attack (AoA) is less than 10°. The transient tail vibration behaviour in the cruise period when using MFC actuators is studied over wide ranges of frequency, AoA and vibration amplitude. The buffet frequency is locked in by the vibration frequency, and a decrease of 1.66–2.32% in Cd can be achieved by using a proper vibration frequency and amplitude.
Multi-agent cooperative multi-model adaptive guidance law
Authors: Wang S.B. , Wang S.C. , Liu Z.G. , Zhang S. , Guo Y.
Published: March 2021

A multi-agent engagement scenario is considered in which a high-value aircraft launches two defenders to intercept two homing missiles aimed at the aircraft. Under the assumption that all aircrafts have first-order linear dynamic characteristics, a combined multiple-mode adaptive estimation (MMAE) and a two-way cooperative optimal guidance law are proposed for the target–defenders team. Considering the full cooperation of the target and both the two defenders, the two-way cooperative strategies provide the analytical expressions for their optimal control input, enabling the target–defenders team to intercept the missiles with minimal control effort. To successfully intercept the missiles, MMAE is used to identify the guidance laws adopted by the missiles and estimate their states. The simulation results show that the target cooperating with the defenders to perform lure manoeuvres for the missiles can improve the guidance performance of the defenders as well as reduce the control effort of the defenders for intercepting the missiles.
A piecewise smooth Fermi–Ulam pingpong with potential
Authors: ZHOU JING
Published: March 2021

In this paper we study a Fermi–Ulam model where a pingpong ball bounces elastically against a periodically oscillating platform in a gravity field. We assume that the platform motion
$f(t)$
is 1-periodic and piecewise
$C^3$
with a singularity,
$\dot {f}(0+)\ne \dot {f}(1-)$
. If the second derivative
$\ddot {f}(t)$
of the platform motion is either always positive or always less than
$-g$
, where g is the gravitational constant, then the escaping orbits constitute a null set and the system is recurrent. However, under these assumptions, escaping orbits co-exist with bounded orbits at arbitrarily high energy levels.
The death of Adumissa: a suicide at Cape Coast, Ghana, around 1800
Authors: Parker John
Published: March 2021

This article examines the history of voluntary death on the Gold Coast in present-day Ghana. Its focus is the suicide of a young woman named Adwoa Amissa (or Adumissa), who took her own life in dramatic fashion in the town of Cape Coast in the early nineteenth century. Adumissa killed herself in response to the earlier suicide of a thwarted suitor, who declared his own self-destruction to be ‘on her head’, thereby transferring the responsibility to her. These events, which were recorded by Sarah Bowdich, an English resident of Cape Coast in 1816–18, made Adumissa a legendary figure in the Fante region of the Gold Coast and beyond. Despite the interpretive complexities of Bowdich's text, two aspects of the episode reveal themselves as central to an understanding of its cultural context: the impact of the spoken word and the practice of aggressive ‘revenge suicide’ among the Akan and their neighbours. It is within this culturally meaningful and contingent framework that questions about Adumissa's emotional impulses, motivations and agency must be situated.
Public authority and its demons: the Sherbro leopard murders in Sierra Leone
Authors: Richards Paul
Published: March 2021

Demonization is a widespread aspect of political discourse. We are familiar with the demonization of Brussels bureaucrats as a tool for pursuing the British exit from the European Union, and we take stories about the compulsory straightening of bananas with a pinch of salt, however frustrating it might be that some disaffected voters choose to accept these canards as true. But somehow, stories about the demonic in Africa have been accorded much greater ontological respect, not only by colonial powers keen to boost their own legitimacy through claims to a civilizing mission, but also by anthropologists anxious to understand their informants’ imaginative concerns, perhaps without fully appreciating the political craft or guile with which these discourses are invested. In seeking to void the charge of delusion, an empathetic reading of demonization risks missing the strategic significance of mythic interventions intended to extract political advantage. This article examines an instance of mythic creativity in the politics of late nineteenth-century interior Sierra Leone as an example of the stagecraft sometimes implicit in African public authority. The case is that of the human leopard, an avatar of commercially compromised chieftaincy. The article asks whether the alleged activities of these leopards were the straight bananas of a certain form of anti-colonial political resistance. In a concluding discussion, some consequences for understanding current forms and practices of local public authority are inferred.
Studies on the population biology of helminth parasites of fish species from the Caspian Sea drainage basin
Authors: Abdybekova A.M. , Assylbekova S.Zh. , Abdibayeva A.A. , Zhaksylykova A.A. , Barbol B.I. , Aubakirov M.Zh. , Torgerson P.R.
Published: March 2021

The northern section of the Caspian Sea and lower reaches of the Zhaiyk (Ural) River is an important fishery for Kazakhstan. In the present study, a total of 1597 individuals of ten fish species were analysed. The fish were caught over three years, from 2018 to 2020. For each species studied –Abramis brama,Alosa saposchnikowii,Atherina boyeri caspia,Carassius gibelio,Chelon auratus,Cyprinus carpio,Leuciscus aspius,Rutilus caspius,Sander marinusandSander volgensis– between 100 and 200 individuals were examined. A series of generalized linear models (GLMs) were used to examine the association between individual parasite intensity of infection and the Fulton index, age, year the fish was captured, where the fish was captured (northern Caspian or Zhaiyk River) and sex. For each GLM, the best-fitting probability distribution was used –either Poisson, zero-inflated Poisson, negative binomial or zero-inflated negative binomial. For some fish/parasite species, an increased Fulton index was associated with higher intensities of parasite infection, whilst, for others, the Fulton index decreased with the intensity of parasite infection. This was also true of age-related intensity of infection, with some parasites having an increased intensity of infection with age whilst others had a decreased intensity of infection with age. There was also some evidence of variation in intensity of parasite infection between different years when the fish were caught. For some species of fish that are endemic to both the fresh waters of the Zhaiyk River and the low-saline waters of the northern Caspian, there were variations in intensity of parasite infection between the two environments. The best-fitting probability distribution also gave some information about the dynamics of infection. No fish species had a Poisson distribution of parasites, which is consistent with an entirely random infection process, with all fish being potentially exposed. For some parasites, the distribution was a zero-inflated Poisson, which is consistent with either the fish being exposed to parasite infection or not; and, if exposed, infection was a random process. Other parasites had a negative binomial distribution, consistent with the entire fish population being exposed, but the infection process was clumped or there were variations in the susceptibility of infection between fish. Finally, some of the parasites had a zero-inflated negative binomial distribution, which can be interpreted as part of the fish population not being exposed and the remainder of the population being exposed to a clumped or aggregated infection process and/or a variation in individual susceptibility to infection.
Managing narratives, managing identities: Language and credibility in legal consultations with asylum seekers
Authors: Jacobs Marie , Maryns Katrijn
Published: March 2021

This study examines interactional management practices and narrative co-construction in lawyer-asylum seeker consultations in Flanders, Belgium. Drawing upon linguistic-ethnographic fieldwork, it presents a case study of a consultation between an Afghan applicant for international protection, his adviser, and his lawyer. The purpose of the consultation is to prepare the applicant for testifying at the upcoming asylum hearing. Data analysis focuses on (i) the reorientation of the asylum narrative from an authentic-experiential towards a more objectified formal-institutional account; (ii) the participants’ positioning work that indexes this reorientation process; and (iii) their fluctuating alignment of local-interactional and translocal-gatekeeping perspectives. In the discussion, we analyse the consultation in terms of competing legal and experiential voices and views on participant roles/responsibilities. We reflect on how this ambiguity of roles and ideologies relates to the constructed character of credibility, which reveals the importance of adequate legal assistance in this linguistically challenging context. (Legal consultations, asylum procedure, linguistic ethnography, narrative performance, credibility assessment)*
The polarization constant of finite dimensional complex spaces is one
Authors: DIMANT VERÓNICA , GALICER DANIEL , RODRÍGUEZ JORGE TOMÁS
Published: March 2021

The polarization constant of a Banach spaceXis defined as\[{\text{c}}(X){\text{ }}{\text{ }}\mathop {\lim }\limits_{k \to \infty } {\text{ }}\sup {\text{c}}{(k,X)^{\frac{1}{k}}},\]

where\[{\text{c}}(k,X)\]stands for the best constant\[C > 0\]such that\[\mathop P\limits^ \vee \leqslant CP\]for everyk-homogeneous polynomial\[P \in \mathcal{P}{(^k}X)\]. We show that ifXis a finite dimensional complex space then\[{\text{c}}(X) = 1\]. We derive some consequences of this fact regarding the convergence of analytic functions on such spaces.

The result is no longer true in the real setting. Here we relate this constant with the so-called Bochnak’s complexification procedure.

We also study some other properties connected with polarization. Namely, we provide necessary conditions related to the geometry ofXfor\[c(2,X) = 1\]to hold. Additionally we link polarization constants with certain estimates of the nuclear norm of the product of polynomials.
The effect of content-related and external factors on student retention in LMOOCs
Authors: Friðriksdóttir Kolbrún
Published: March 2021

Commonly, low completion rates in massive open online courses have called into question the quality of their learning materials and instruction. This paper attempts to identify crucial factors of engagement and retention in language massive open online courses (LMOOCs) in the context of the open online program of Icelandic Online, a self-guided course for second language learners of Icelandic. The study seeks to explore the impact of factors associated with the course’s instructional design on engagement and retention and reveal crucial determinants of attrition. The study depends on survey and tracking data from 400 learners and qualitative data from 62 informants in one course. It builds on previous studies on student engagement and retention in LMOOCs (Friðriksdóttir, 2018, 2019). The present study identified six content-specific factors that the majority of participants considered to be important for their motivation. Some factors, such as gradual and scaffolded presentation of input, had a positive impact on retention. Furthermore, statements from learners in the study who disengaged before completing show that non-course-related factors, such as time constraints, affect LMOOC retention. The study provides a new framework for how to promote student engagement and suggests specific strategies for other LMOOC developers.
Unusual presentation of mitral prosthetic heart valve thrombosis managed with low dose tenecteplase infusion
Authors: Ahmed A. Shaheer , Gupta Shivank
Published: March 2021

A 11-year-old with history of mitral valve replacement presented with low-grade fever, breathlessness and multiple episodes of haemoptysis for 2 days. Detailed echocardiographic evaluation revealed possible prosthetic valve thrombosis, which was confirmed by fluoroscopy. She was thrombolysed with low dose infusion of tenecteplase. Post thrombolysis her symptoms improved, valve mobility was restored, and haemoptysis subsided. Left sided prosthetic valve thrombosis presenting predominantly with haemoptysis is very rare.
Better preoperative exercise function is associated with shorter hospital stay after paediatric pulmonary valve replacement or conduit revision
Authors: Gauthier Naomi , Muter Angelika , Rhodes Jonathan , Gauvreau Kimberlee , Nathan Meena
Published: March 2021

Exercise capacity is a modifiable factor in patients with CHD that has been related to surgical outcomes in adults. We hypothesised that this was true for children undergoing surgical pulmonary valve replacement; therefore, the relationship of preoperative percent predicted peak oxygen consumption to surgical outcomes as measured by total hospital length of stay was explored.

Methods:

Single centre retrospective cohort study of patients aged 8–18 years who underwent surgical pulmonary valve replacement. The primary predictor was preoperative percent predicted peak oxygen consumption, and primary outcome was total hospital length of stay. Clinical, imaging, and cardiopulmonary exercise test data were reviewed and compared to total hospital length of stay. Cox proportional hazards regression was used to examine the association between total hospital length of stay and percent predicted peak oxygen consumption.

Results:

Three-hundred and seventy patients undergoing pulmonary valve replacement/conduit change between 2003 and 2017 at Boston Children’s Hospital were identified. Ninety had preoperative cardiopulmonary exercise tests within 6 months of surgery. Exclusion for inadequate exercise data (n = 3) and imaging data (n = 1) left 86 patients for review. Patients with percent predicted peak oxygen consumption ≥ 70% (n = 46, 53%) had shorter total hospital length of stay (4.4 days) than the 40 with percent predicted peak oxygen consumption <70% (5.4 days, p = 0.007). Median percent predicted peak oxygen consumption increased over sequential surgical eras (p < 0.001), but total hospital length of stay did not correlate with surgical era, preoperative left ventricular function, or preoperative right ventricular dilation.

Conclusion:

Children undergoing surgical pulmonary valve replacement with better preoperative exercise capacity had shorter total hospital length of stay. Exercise capacity is a potentially modifiable factor prior to and after pulmonary valve replacement. Until more patients systematically undergo cardiopulmonary exercise tests, the full impact of optimisation of exercise capacity will not be known.
Older people living at home: experiences of healthy ageing
Authors: Fjell Astrid , Eriksen Kristin Ådnøy , Hermann Monica , Boström Anne-Marie , Cronfalk Seiger Berit
Published: March 2021

Aim:

The purpose of this study was to investigate how old persons perceived their life to be, how they viewed the ageing process and their need of health care and societal support.

Background:

The purpose of WHO’s Healthy Ageing strategy and development of age-friendly environments is to support physiological and psychosocial changes in old persons by facilitating basic needs. Interventions to operationalize these needs in older people living at home are often developed from a professional perspective and to a small extent involves the perceptions, experience and expectations of the older persons.

Method:

This qualitative study has an explorative design using focus group discussions to collect data. In all, 34 persons between 69 and 93 years of age participated in seven group discussions. The interviews were analyzed using inductive manifest content analysis.

Findings:

The main results suggest that most old persons enjoyed life and wished it to continue for as long as possible. Important was to sustain networks and to feel useful. Unexpected changes were described as threats and the need to use health care services was associated with illness and being dependent. The result is presented in three categories with sub-categories: ‘Embracing life’, ‘Dealing with challenges’ and ‘Considering the future’.
“Airing Our Dirty Linen in Public”: Lidiia Chukovskaia, Nadezhda Mandeľshtam, and Competing Visions for a Liberal Soviet Counterpublic
Authors: Zaitseva Lusia
Published: March 2021

This article contributes to the study of gender and dissidence in the Soviet Union by examining the feud between two significant authors of cultural samizdat and tamizdat—Nadezhda Mandeľshtam and Lidiia Chukovskaia—through an updated feminist lens. It draws on prose unpublished in their lifetimes and presents previously undiscovered writing by Mandeľshtam in order to examine the origins and substance of their feud. I argue that their distinctive modes of authorship date to their relationship with Anna Akhmatova and subsequent differing approaches to her legacy. These approaches reveal their shared conservative attitude regarding gender and moral authority in the nascent liberal Soviet counterpublic as well as their diverging understandings of how the transnational public sphere could help bring about much-needed changes at home. These attitudes shaped how they regarded each other and continue to have salience for our understanding of women's participation in the public sphere in Russia today.
Autocorrelation Infrasound Interferometry
Authors: Ortiz Hugo D. , Matoza Robin S. , Johnson Jeffrey B. , Hernandez Stephen , Anzieta Juan C. , Ruiz Mario C.
Published: March 2021

Seismic and infrasound multistation ambient‐noise interferometry has been widely used to infer ground and atmospheric properties, and single‐station and autocorrelation seismic interferometry has also shown potential for characterizing Earth structure at multiple scales. We extend autocorrelation seismic interferometry to ambient atmospheric infrasound recordings that contain persistent local noise from waterfalls and rivers. Across a range of geographic settings, we retrieve relative sound‐speed changes that exhibit clear diurnal oscillations consistent with temperature and wind variations. We estimate ambient air temperatures from variations in relative sound speeds. The frequency band from 1 to 2 Hz appears most suitable to retrieve weather parameters as nearby waterfalls and rivers may act as continuous and vigorous sources of infrasound that help achieve convergence of coherent phases in the autocorrelation codas. This frequency band is also appropriate for local sound‐speed variations because it has infrasound with wavelengths of ∼170–340 m, corresponding to a typical atmospheric boundary layer height. After applying array analysis to autocorrelation functions derived from a three‐element infrasound array, we find that autocorrelation codas are composed of waves reflected off nearby topographic features, such as caldera walls. Lastly, we demonstrate that autocorrelation infrasound interferometry offers the potential to study the atmosphere over at least several months and with a fine time resolution.