bluuebunny/crossref_metadata_2025 huggingface dataset:
Human placental mesenchymal stem cells ameliorate chemotherapy-induced damage in the testis by reducing apoptosis/oxidative stress and promoting autophagy
Authors: Lu Jiafeng , Liu Zhenxing , Shu Mingkai , Zhang Liya , Xia Wenjuan , Tang Liuna , Li Jincheng , Huang Boxian , Li Hong
Published: March 2021

Background

The side effects of busulfan on male reproduction are serious, so fertility preservation in children undergoing busulfan treatment is a major worldwide concern. Human placental mesenchymal stem cells (hPMSCs) have advantages such as stable proliferation and lower immunogenicity that make them an ideal material for stimulating tissue repair, especially restoring spermatogenesis. The protective effects of hPMSCs in busulfan-induced Sertoli cells and in busulfan-treated mouse testes have not been determined. Our study aimed to elaborate the protective effect and potential mechanisms of hPMSCs in busulfan-treated testes and Sertoli cells.

Methods

First, we developed a mouse model of busulfan-induced testicular toxicity in vivo and a mouse Sertoli cell line treated with busulfan in vitro to assess the protective effect and mechanisms of hPMSC treatment on spermatogenesis. Then, the length, width, and weight of the testes were monitored using Vernier calipers. Furthermore, at 1 week and 4 weeks after the transplantation of hPMSCs, histological sections of testes were stained with hematoxylin-eosin, and the seminiferous tubules with fluid-filled cavities were counted. Through ELISA analysis, testosterone levels and MDA, SOD, LDH, and CAT activities, which are associated with ROS, were detected. Markers of ROS, proliferation (Ki67), and apoptosis (Annexin V) were evaluated by FACS. Next, the fluorescence intensity of proliferation markers (BrdU and SCP3), an antioxidant marker (SIRT1), a spermatogenesis marker (PLZF), and autophagy-related genes (P62 and LC3AB) were detected by fluorescence microscopy. The mRNA expression of γ-H2AX, BRCA1, PARP1, PCNA, Ki67, P62, and LC3 was determined by qRT-PCR.

Results

hPMSCs restored disrupted spermatogenesis, promoted improved semen parameters, and increased testosterone levels, testis size, and autophagy in the testis toxicity mouse model induced by busulfan. hPMSCs suppressed the apoptosis of Sertoli cells and enhanced their rate of proliferation in vitro. Additionally, hPMSCs protected against oxidative stress and decreased oxidative damage in the testis toxicity mouse model induced by busulfan. Furthermore, hPMSCs increased the expression of proliferation genes (PCNA and KI67) and decreased the mRNA levels of apoptotic genes such as γ-H2AX, BRCA1, and PARP1.

Conclusions

This research showed that hPMSC injection ameliorated busulfan-induced damage in the testis by reducing apoptosis/oxidative stress and promoting autophagy. The present study offers an idea for a new method for clinical treatment of chemotherapy-induced spermatogenesis.
Molecular optimization by capturing chemist’s intuition using deep neural networks
Authors: He Jiazhen , You Huifang , Sandström Emil , Nittinger Eva , Bjerrum Esben Jannik , Tyrchan Christian , Czechtizky Werngard , Engkvist Ola
Published: March 2021

A main challenge in drug discovery is finding molecules with a desirable balance of multiple properties. Here, we focus on the task of molecular optimization, where the goal is to optimize a given starting molecule towards desirable properties. This task can be framed as a machine translation problem in natural language processing, where in our case, a molecule is translated into a molecule with optimized properties based on the SMILES representation. Typically, chemists would use their intuition to suggest chemical transformations for the starting molecule being optimized. A widely used strategy is the concept of matched molecular pairs where two molecules differ by a single transformation. We seek to capture the chemist’s intuition from matched molecular pairs using machine translation models. Specifically, the sequence-to-sequence model with attention mechanism, and the Transformer model are employed to generate molecules with desirable properties. As a proof of concept, three ADMET properties are optimized simultaneously:logD,solubility, andclearance, which are important properties of a drug. Since desirable properties often vary from project to project, the user-specified desirable property changes are incorporated into the input as an additional condition together with the starting molecules being optimized. Thus, the models can be guided to generate molecules satisfying the desirable properties. Additionally, we compare the two machine translation models based on the SMILES representation, with a graph-to-graph translation model HierG2G, which has shown the state-of-the-art performance in molecular optimization. Our results show that the Transformer can generate more molecules with desirable properties by making small modifications to the given starting molecules, which can be intuitive to chemists. A further enrichment of diverse molecules can be achieved by using an ensemble of models.
Cooperative treatment effectiveness of ATR and HSP90 inhibition in Ewing’s sarcoma cells
Authors: Marx Christian , Schaarschmidt Marc U. , Kirkpatrick Joanna , Marx-Blümel Lisa , Halilovic Melisa , Westermann Martin , Hoelzer Doerte , Meyer Felix B. , Geng Yibo , Buder Katrin , Schadwinkel Hauke M. , Siniuk Kanstantsin , Becker Sabine , Thierbach René , Beck James F. , Sonnemann Jürgen , Wang Zhao-Qi
Published: March 2021

Introduction

Ewing's sarcoma is an aggressive childhood malignancy whose outcome has not substantially improved over the last two decades. In this study, combination treatments of the HSP90 inhibitor AUY922 with either the ATR inhibitor VE821 or the ATM inhibitor KU55933 were investigated for their effectiveness in Ewing's sarcoma cells.

Methods

Effects were determined in p53 wild-type and p53 null Ewing's sarcoma cell lines by flow cytometric analyses of cell death, mitochondrial depolarization and cell-cycle distribution as well as fluorescence and transmission electron microscopy. They were molecularly characterized by gene and protein expression profiling, and by quantitative whole proteome analysis.

Results

AUY922 alone induced DNA damage, apoptosis and ER stress, while reducing the abundance of DNA repair proteins. The combination of AUY922 with VE821 led to strong apoptosis induction independent of the cellular p53 status, yet based on different molecular mechanisms. p53 wild-type cells activated pro-apoptotic gene transcription and underwent mitochondria-mediated apoptosis, while p53 null cells accumulated higher levels of DNA damage, ER stress and autophagy, eventually leading to apoptosis. Impaired PI3K/AKT/mTOR signaling further contributed to the antineoplastic combination effects of AUY922 and VE821. In contrast, the combination of AUY922 with KU55933 did not produce a cooperative effect.

Conclusion

Our study reveals that HSP90 and ATR inhibitor combination treatment may be an effective therapeutic approach for Ewing's sarcoma irrespective of the p53 status.
Community-based educational interventions for prevention of type II diabetes: a global systematic review and meta-analysis
Authors: Shirvani Tayebeh , Javadivala Zeinab , Azimi Somayeh , Shaghaghi Abdolreza , Fathifar Zahra , Devender Bhalla H. D. R. , Abdekhoda Mohammadhiwa , Nadrian Haidar
Published: March 2021

Purpose

Our objective was to estimate the change in community-based education interventions throughout the world that may effectuate in risk parameters of type II diabetes (T2D), including the diabetes incidence rate, fasting blood glucose, hemoglobin A1C, body mass index, waist circumference, and systolic and diastolic blood pressure.

Methods

A comprehensive search for globally eligible studies was conducted on PubMed, Embase, ProQuest, CINAHL nursing & allied health source, Cochrane Library, Google Scholar, conference proceedings, and reference lists. Data were extracted using JBI standardized data extraction tool. The primary outcome variables were diabetes incidence rate, fasting blood sugar (FBS), hemoglobin A1c (HbAlc), body mass index (BMI), waist circumference (WC), systolic/diastolic blood pressure (s/d BP). Random-effects meta-analysis and sub-group analyses were conducted.

Results

Nineteen interventional studies were included in the review, and ten studies were pooled in the meta-analysis (n = 16,106, mean age = 41.5 years). The incidence rate of T2D was reported in three trials, within which the risk of developing T2D was reduced by 54.0% in favor of community-based educational interventions, (RR = 0.54, 95% CI = 0.38–0.75; p < 0.001). In eleven (n = 11,587) and six (n = 6416) studies, the pooled mean differences were − 0.33 (95% CI: − 0.45 to − 0.20, p < 0.0001) and − 0.15 (95% CI: − 0.28 to − 0.03, p < 0.0001) for FBS and HbA1c levels, respectively. Positive significant effects were observed on reducing BMI [pooled mean difference = − 0.47 (95% CI: − 0.66 to − 0.28), I2 = 95.7%, p < 0.0001] and WC [pooled mean difference = − 0.66 (95% CI: − 0.89 to − 0.43), I2 = 97.3%, p < 0.0001]. The use of theoretical frameworks was found to provide a 48.0% change in fasting blood sugar.

Conclusions

Based on a comprehensive data collection of about 16,106 participants and reasonable analyses, we conclude that educational interventions may reduce diabetes incidence by 54.0%, particularly through reductions in fasting blood glucose, body mass index, and waist circumference. The diabetes risk parameters may favorably improve irrespective of the duration of intervention, at as low as 6 months. The application of theoretical frameworks while designing educational interventions is also encouraged.

Systematic review registration

PROSPERO CRD42018115877
Optimal harvesting strategies of a stochastic competitive model with S-type distributed time delays and Lévy jumps
Authors: Qiu Hong , Deng Wenmin , Xiang Mingqi
Published: March 2021

The aim of this paper is to investigate the optimal harvesting strategies of a stochastic competitive Lotka–Volterra model with S-type distributed time delays and Lévy jumps by using ergodic method. Firstly, the sufficient conditions for extinction and stable in the time average of each species are established under some suitable assumptions. Secondly, under a technical assumption, the stability in distribution of this model is proved. Then the sufficient and necessary criteria for the existence of optimal harvesting policy are established under the condition that all species are persistent. Moreover, the explicit expression of the optimal harvesting effort and the maximum of sustainable yield are given.
Central versus wellhead power plants in geothermal grid electricity generation
Authors: Kabeyi Moses Jeremiah Barasa , Olanrewaju Oludolapo A.
Published: March 2021

The long gestation period, high upfront costs and the risks in the development of central geothermal power plants are the main reasons for the slow rate of geothermal electricity growth and its contribution to the global electricity mix. The overall objective of this study was to make a comparison between central geothermal power plants and wellhead power plants in the delivery of geothermal electricity projects. The study showed that wellhead power plants are generally less efficient compared to central power plants because of higher specific steam consumption, but are financially attractive because of the quicker return on investment, early electricity generation and the lower financial risks. The study showed that permanent wellhead power plants are a better option for geothermal wells with too low or too high steam pressure compared to others in the steam field. Temporary use of wellhead power plants as opposed to their permanent use is preferred when only limited time is available between the commissioning of a wellhead plant and the commissioning of a central power plant in the same steam field. Technical, operational and environmental challenges, including higher specific steam consumption and lower efficiency than central power plants as well as absence of geothermal fluid reinjection system make wellhead plants less economical and less sustainable in resource use. It can thus be concluded that wellhead power plants can reduce the long wait to generate geothermal electricity and make an early return on investment for investors. Both central and wellhead power plants have relatively higher capacity factor than many other power plants and so can be used to supply base load electricity for the grid or off-grid power supply. This study is a review of the central and wellhead power plants and additionally provides policy guidelines in the execution of geothermal electricity projects either as central or wellhead power plants for grid electricity generation.
PR interval as a predictor of syncope in tilt-up testing in adolescents and young adults
Authors: Jug Juraj , Bradić Lada , Levicki Rea , Benčić Martina Lovrić
Published: March 2021

Background

Syncope, as the most frequent consciousness disorder, is very common in young individuals. The aim of this study was to analyze ECG parameters and clinical properties obtained during tilt-up testing in 12 to 30-year-old subjects. We enrolled a total of 142 patients from our outpatient clinic (39 males, 103 females) with a true positive tilt-up test and analyzed ECG records obtained during tilt-testing. Data were stratified according to the age, gender, and type of syncope.

Results

PR interval shortening preceding syncope was found in all syncope types, irrespective of the gender. All types of syncope were more frequent in women (72.5%). Mixed syncope type was found to be the most common (47.18%). Male and female subjects differed in initial heart rate (71.56 vs 76.23/min, p=0.05), as well as heart rate dynamics during tilt-up testing. A gender difference was also found in systolic blood pressure (116.92 vs 110.44 mmHg, p<0.01), time to syncope onset (20.77 vs. 16.44 min, p=0.03), and the total number of syncopal episodes in patient history (2.79 vs. 4.62, p<0.05). Subjects with cardioinhibitory syncope had the longest PR interval (average 154.3 ms). PR interval prolongation and loss of variability during tilt-up testing positively correlated with aging (r=0.22, p<0.05). Nodal rhythm was found in 8 patients.

Conclusion

PR interval shortening on ECG tracings during a tilt-up test can be found in all subtypes of vasovagal syncope, thereby contrasting previous reports that these changes are a hallmark of the cardioinhibitory type of syncope. PR shortening, if observed during ECG monitoring, could be a potential predictor of syncope.
Impurity effects in a two-dimensional nonsymmorphic Dirac semimetal
Authors: He Chaocheng
Published: March 2021

We theoretically study the impurity-induced states in a two-dimensional nonsymmorphic Dirac semimetal based on the T-matrix method. For calculating the local density of states, we find that for a Dirac system with two symmetry-inequivalent Dirac points the impurity states are similar to those in an ordinary two-dimensional Dirac sysytem. Whereas for the situation of two symmetry-equivalent Dirac points, the impurity states exhibit many distinct features, which are attributed to the spin-sublattice correlation associated with nonsymmorphic symmetry. In particular, these features are robust for the presence of the chiral symmetry-breaking term. Furthermore the impurity states in a Weyl semimetal and topological insulator with nonsymmorphic symmetries are derived and discussed. Thus the impurity effects of a two-dimensional nonsymmorphic Dirac semimetal can be used to probe the various topological nontrivial phases.
Symmetry and fluctuation of cell movements in neural crest-derived facial mesenchyme
Authors: Danescu Adrian , Rens Elisabeth G. , Rehki Jaspreet , Woo Johnathan , Akazawa Takashi , Fu Katherine , Edelstein-Keshet Leah , Richman Joy M.
Published: March 2021

In the face, symmetry is established when bilateral streams of neural crest cells leave the neural tube at the same time, follow identical migration routes and then give rise to the facial prominences. However, developmental instability exists, particularly surrounding the steps of lip fusion. The causes of instability are unknown but inability to cope with developmental fluctuations are a likely cause of congenital malformations, such as non-syndromic orofacial clefts. Here, we tracked cell movements over time in the frontonasal mass, which forms the facial midline and participates in lip fusion, using live-cell imaging of chick embryos. Our mathematical examination of cell velocity vectors uncovered temporal fluctuations in several parameters, including order/disorder, symmetry/asymmetry and divergence/convergence. We found that treatment with a Rho GTPase inhibitor completely disrupted the temporal fluctuations in all measures and blocked morphogenesis. Thus, we discovered that genetic control of symmetry extends to mesenchymal cell movements and that these movements are of the type that could be perturbed in asymmetrical malformations, such as non-syndromic cleft lip.

This article has an associated ‘The people behind the papers’ interview.
Murine intestinal stem cells are highly sensitive to modulation of the T3/TRα1-dependent pathway
Authors: Godart Matthias , Frau Carla , Farhat Diana , Giolito Maria Virginia , Jamard Catherine , Le Nevé Clementine , Freund Jean-Noel , Penalva Luiz O. , Sirakov Maria , Plateroti Michelina
Published: March 2021

The thyroid hormone T3 and its nuclear receptor TRα1 control gut development and homeostasis through the modulation of intestinal crypt cell proliferation. Despite increasing data, in-depth analysis on their specific action on intestinal stem cells is lacking. By using ex vivo 3D organoid cultures and molecular approaches, we observed early responses to T3 involving the T3-metabolizing enzyme Dio1 and the transporter Mct10, accompanied by a complex response of stem cell- and progenitor-enriched genes. Interestingly, specific TRα1 loss-of-function (inducible or constitutive) was responsible for low ex vivo organoid development and impaired stem cell activity. T3 treatment of animals in vivo not only confirmed the positive action of this hormone on crypt cell proliferation but also demonstrated its key action in modulating the number of stem cells, the expression of their specific markers and the commitment of progenitors into lineage-specific differentiation. In conclusion, T3 treatment or TRα1 modulation has a rapid and strong effect on intestinal stem cells, broadening our perspectives in the study of T3/TRα1-dependent signaling in these cells.
The RAC1 activator Tiam1 regulates centriole duplication through controlling PLK4 levels
Authors: Porter Andrew P. , Reed Hannah , White Gavin R. M. , Ogg Erinn-Lee , Whalley Helen J. , Malliri Angeliki
Published: March 2021

Centriole duplication is tightly controlled to maintain correct centriole number through the cell cycle. Key to this is the regulated degradation of PLK4, the master regulator of centriole duplication. Here, we show that the Rac1 guanine nucleotide exchange factor (GEF) Tiam1 localises to centrosomes during S-phase, where it is required for the maintenance of normal centriole number. Depletion of Tiam1 leads to an increase in centrosomal PLK4 and centriole overduplication, whereas overexpression of Tiam1 can restrict centriole overduplication. Ultimately, Tiam1 depletion leads to lagging chromosomes at anaphase and aneuploidy, which are potential drivers of malignant progression. The effects of Tiam1 depletion on centrosomal PLK4 levels and centriole overduplication can be rescued by re-expression of both wild-type Tiam1 and catalytically inactive (GEF*) Tiam1, but not by Tiam1 mutants unable to bind to the F-box protein βTRCP (also known as F-box/WD repeat-containing protein 1A) implying that Tiam1 regulates PLK4 levels through promoting βTRCP-mediated degradation independently of Rac1 activation.
Daily temperature cycles prolong lifespan and have sex-specific effects on peripheral clock gene expression in Drosophila melanogaster
Authors: Goh Grace H. , Blache Dominique , Mark Peter J. , Kennington W. Jason , Maloney Shane K.
Published: March 2021

Circadian rhythms optimize health by coordinating the timing of physiological processes to match predictable daily environmental challenges. The circadian rhythm of body temperature is thought to be an important modulator of molecular clocks in peripheral tissues, but how daily temperature cycles affect physiological function is unclear. Here, we examined the effect of constant temperature (Tcon, 25°C) and cycling temperature (Tcyc, 28°C:22°C during light:dark) paradigms on lifespan of Drosophila melanogaster, and the expression of clock genes, heat shock protein 83 (Hsp83), Frost (Fst) and senescence marker protein-30 (smp-30). Male and female D. melanogaster housed at Tcyc had longer median lifespans than those housed at Tcon. Tcyc induced robust Hsp83 rhythms and rescued the age-related decrease in smp-30 expression that was observed in flies at Tcon, potentially indicating an increased capacity to cope with age-related cellular stress. Ageing under Tcon led to a decrease in the amplitude of expression of all clock genes in the bodies of male flies, except for cyc, which was non-rhythmic, and for per and cry in female flies. Strikingly, housing under Tcyc conditions rescued the age-related decrease in amplitude of all clock genes, and generated rhythmicity in cyc expression, in the male flies, but not the female flies. The results suggest that ambient temperature rhythms modulate D. melanogaster lifespan, and that the amplitude of clock gene expression in peripheral body clocks may be a potential link between temperature rhythms and longevity in male D. melanogaster. Longevity due to Tcyc appeared predominantly independent of clock gene amplitude in female D. melanogaster.
CPUE comparison of traditional crayfish fyke net rigged with knotted net and alternatively knotless net
Authors: Cilbiz Mehmet , Uysal Rahmi , Yağcı Abdulkadir , Korkut S. Oğuz , Çapkın Kadir , Cesur Mehmet
Published: March 2021

In this study, it is aimed to compare the yield and strength of the crayfish fyke rigged with knotless net with 210d/12 rope thickness with those of the traditional net material rigged with 210d/6 knotted net which is widely used in Turkey in fishing crayfish (Pontastacus leptodactylus, Eschscholtz, 1823). The study was carried out on a monthly basis between June 2017 and May 2018. In the study, a total of 300 fyke nets, equipped with 150 classical and 150 alternative nets, were used. The caught crayfishes were measured and weighted according to the fyke net they were caught in. A total of 3509 crayfish were caught, 1465 of which were caught with alternative fyke net and 2044 with traditional fyke net. Average CPUE value ranged from 10.93 (g/fyke net/day) to 281.14 (g/fyke net/day) for per fishing operation. Average CPUE value of the traditional gear was found to be 98.34 (g/fyke net/day) , while that of the alternative gear was determined as 79.46 (g/fyke net/day), and no statistically significant difference was found between average CPUE values (p>0.05). Average strength value of the traditional fyke net was determined as (± SE) 10.43 ± 0.27 kg, while that value in 210d / 12 knotless net was identified as 14.50 ± 0.91 kg (p<0.05). Although it has high strength, since the CPUE value of the alternative fyke net is lower by 19.20% compared to the traditional gear, it is believed that its use in crayfish fishing will not be profitable.
Control of ECB tests depending on their operating conditions
Authors: Kozyukov Aleksandr , Meerson Vera , Oksyuta O. , Achkasov A.
Published: March 2021

The paper considers the requirements for test benches for studying the appearance of single radiation effects in the electronic component base (ECB) at elevated and low temperatures. Examples of the influence of the temperature regime on the levels of ECB stability, as well as the influence of the passive and active modes of radio-electronic equipment on the occurrence of single events are presented.
METHODS FOR ENSURING THE STABILITY OF THE ELECTRONIC COMPONENT BASE IN TERMS OF REVERSIBLE SINGLE EVENTS
Authors: Kozyukov Aleksandr , Raspopov G. , Yankov A. , Zolnikov Konstantin , Evdokimova Svetlana
Published: March 2021

The problem of ensuring the stability of the electronic component base in the event of reversible single events and its solution by N-fold redundancy methods is considered. The paper presents a description, scheme, advantages and disadvantages of N-fold redundancy methods, such as duplication with a loaded backup element, various modifications of redundancy, sliding redundancy, and the use of a watchdog timer.
THE RESOURCE SAVING PROBLEMS SAVING CONSIDERING SPECIFICS OF SEVERAL 2D PLACEMENT TASKS
Authors: Kushcheva I. , Khukhryanskaya E.
Published: March 2021

Specific tasks of regular dense 2D placement of objects of different metric characteristics in a close non-binded area of a complex geometry, oriented for CAD applications are highlighted in this work. Methods of minimizing losts of consumed raw materials were analysed with the basement of provided unified geometric model.
MODELING THE PROCESS OF INSPECTION OF REINFORCED CONCRETE SUPPORTS OF TECHNOLOGICAL OVERPASSES
Authors: Rogov N , Nikolenko S. , Sazonova Svetlana
Published: March 2021

The paper presents the process of assessing the technical condition of reinforced concrete supports of existing technological overpasses. The characteristics of overpasses are given. Defects identified in the process of assessing the technical condition are shown. The paper describes the control of concrete strength by the non-destructive method of elastic rebound using the Digi Shmidt 2000 device and the determination of the concrete cover thickness and the location of reinforcement by the magnetic method using the Profometer-5S device. The layout of the working reinforcement in the reinforced concrete supports of the overpass section has been determined. The results of verification calculations of the structures of technological ramps are given, taking into account the revealed defects and damages, the strength of materials and the specified actual loads. Proposals are given for improving the performance of concrete of reinforced concrete supports of overpasses.
MODEL OF INDIVIDUALLY GROUP ASSIGNMENT OF ACCESS TO HIERARCHICALLY ORGANIZED OBJECTS OF CRITICAL INFORMATION SYSTEMS USING MOBILE TECHNOLOGIES
Authors: Rogozin E. , Khvostov Viktor , Suhanov Valeriy , Korobkin D. , Mochalov D.
Published: March 2021

The analysis of access control models currently used in information security systems (SPI) is carried out. Based on the analysis of the advantages and disadvantages of discretionary, authoritative and role models in the implementation of access of mobile systems of subjects with different needs and roles to hierarchically organized information objects of medical information systems (MIS), it is proposed to use access control based on a thematic - hierarchical policy. The methods of forming thematic grids that provide security control of information flows are proposed. The article offers methods for setting the reachability matrix for reading, writing, and executing different access subjects to access objects with monorubricated and multi-rubricated hierarchical thematic classification.
Contradictions, Conflicts and Crises in the Development of the Functional Infrastructure of Consumer Lending
Authors: Tursunov B.
Published: March 2021

When characterizing the infrastructure of the consumer lending market, it should be assessed not only by isolated structural elements, but also in general in their interaction. It is worth noting that statistical material on the infrastructure of the consumer lending market is often rather scarce and cannot give an exhaustive picture of the state of the consumer lending infrastructure, therefore, for the development of the consumer lending infrastructure, it is necessary to consider not only the infrastructure elements, but also need to penetrate into their problems.
On the Fair Division of a Random Object
Authors: Bogomolnaia Anna , Moulin Hervé , Sandomirskiy Fedor
Published: March 2021

Ann likes oranges much more than apples; Bob likes apples much more than oranges. Tomorrow they will receive one fruit that will be an orange or an apple with equal probability. Giving one half to each agent is fair for each realization of the fruit. However, agreeing that whatever fruit appears will go to the agent who likes it more gives a higher expected utility to each agent and is fair in the average sense: in expectation, each agent prefers the allocation to the equal division of the fruit; that is, the agent gets a fair share. We turn this familiar observation into an economic design problem: upon drawing a random object (the fruit), we learn the realized utility of each agent and can compare it to the mean of the agent’s distribution of utilities; no other statistical information about the distribution is available. We fully characterize the division rules using only this sparse information in the most efficient possible way while giving everyone a fair share. Although the probability distribution of individual utilities is arbitrary and mostly unknown to the manager, these rules perform in the same range as the best rule when the manager has full access to this distribution.

This paper was accepted by Ilia Tsetlin, behavioral economics and decision analysis.
Land subdivision: How students determine equal area
Authors: Hendroanto Aan
Published: March 2021

This study aims to support student’s understanding of the properties of a bisector related to the area of the triangle. A context and a set of activities is design based on Realistic Mathematics Education (RME) theory to develop students’ understanding and to engage them in meaningful activities. Design research is chosen as the research approach with two cycles of experiment. A context of land subdivision problem was selected to activate students’ prior knowledge and to bring them into the activities. At First, the activities is presented in small group of mathematics students and in the regional mathematics competition as one of the final question for the finalists. Then, the second cycle is conducted in the classroom with students from mathematics education program in Universitas Ahmad Dahlan. The result showed that none of the students and finalists in the competition were able to solve the question because they do not have idea how to do land subdivision. They cannot use their prior knowledge of bisector to solve the problem. After revising the activities, in the classroom, all groups in the class were able to solve the problem. These activities are land subdivision with three different levels of difficulties and purposes.
Deep-learning-aided forward optical coherence tomography endoscope for percutaneous nephrostomy guidance
Authors: Wang Chen , Calle Paul , Tran Ton Nu Bao , Zhang Zuyuan , Yan Feng , Donaldson Anthony M. , Bradley Nathan A. , Yu Zhongxin , Fung Kar-ming , Pan Chongle , Tang Qinggong
Published: March 2021

Percutaneous renal access is the critical initial step in many medical
settings. In order to obtain the best surgical outcome with minimum
patient morbidity, an improved method for access to the renal calyx is
needed. In our study, we built a forward-view optical coherence
tomography (OCT) endoscopic system for percutaneous nephrostomy (PCN)
guidance. Porcine kidneys were imaged in our experiment to demonstrate
the feasibility of the imaging system. Three tissue types of porcine
kidneys (renal cortex, medulla, and calyx) can be clearly
distinguished due to the morphological and tissue differences from the
OCT endoscopic images. To further improve the guidance efficacy and
reduce the learning burden of the clinical doctors, a
deep-learning-based computer aided diagnosis platform was developed to
automatically classify the OCT images by the renal tissue types.
Convolutional neural networks (CNN) were developed with labeled OCT
images based on the ResNet34, MobileNetv2 and ResNet50 architectures.
Nested cross-validation and testing was used to benchmark the
classification performance with uncertainty quantification over 10
kidneys, which demonstrated robust performance over substantial
biological variability among kidneys. ResNet50-based CNN models
achieved an average classification accuracy of
82.6%±3.0%. The classification precisions were
79%±4% for cortex, 85%±6%
for medulla, and 91%±5% for calyx and the
classification recalls were 68%±11% for cortex,
91%±4% for medulla, and
89%±3% for calyx. Interpretation of the CNN
predictions showed the discriminative characteristics in the OCT
images of the three renal tissue types. The results validated the
technical feasibility of using this novel imaging platform to
automatically recognize the images of renal tissue structures ahead of
the PCN needle in PCN surgery.
Cavity length control for Fourier domain mode locked (FDML) lasers with µm precision
Authors: Lotz Simon , Grill Christin , Göb Madita , Draxinger Wolfgang , Kolb Jan Philip , Huber Robert
Published: March 2021

In highly dispersion compensated Fourier domain mode locked (FDML) lasers, an ultra-low noise operation can only be achieved by extremely precise and stable matching of the filter tuning period and light circulation time in the cavity. We present a robust and high precision closed-loop control algorithm and an actively cavity length controlled FDML laser. The cavity length control achieves a stability of ∼0.18 mHz at a sweep repetition rate of ∼418 kHz which corresponds to a ratio of 4×10−10. Furthermore, we prove that the rapid change of the cavity length has no negative impact on the quality of optical coherence tomography using the FDML laser as light source.
Dynamics of nonclassical properties of a SU(3) system interacting with two open parametric amplifier modes
Authors: Mohamed A.-B. A. , Hessian H. A. , Obada A.-S. F. , Eleuch H.
Published: March 2021

We introduce an analytical description of an open bimodal cavity containing a

Λ

-type three-level atom. We explore the effect of the atom–cavity nonlinear interaction, the cavity dissipation, and the initial coherent intensity on the dynamics of the nonclassical correlations for a cavity prepared initially in a superposition of nonlinear coherent states. The nonlinear interaction generates a regular entanglement between the subsystems, and populates the energy atomic states. We show that the collapse phenomenon is a good indicator of the generated quantum coherence. The growth of the entropy is used to explore the generated entanglement (if the dissipation is absent) and mixedness (in the presence of the dissipation). It is found that the generation and the robustness of the quantum synchronization and the correlations between the subsystems are very sensitive to the dissipation, the superposition, and the coherent intensity of the initial Barut–Girardello coherent states.
Analysis of a wavelength-tunable D-shaped photonic crystal fiber filter with broad bandwidth
Authors: Meng Xiaojian , Li Jianshe , Guo Ying , Du Huijing , Liu Yundong , Li Shuguang , Guo Haitao , Bi Weihong
Published: March 2021

This paper has designed a D-shaped photonic crystal fiber filter based on surface plasmon resonance. The single-polarization filtering performance is analyzed systematically by the finite element method. It is found that the structural optimization process will modify the refractive index of the fundamental mode and the surface plasmon polarization mode, which results in a shift of the resonance wavelength. The proposed filter is able to indicate the wavelength-tunable function in the ranges of 1250–1350 nm and 1550–1750 nm by two methods. Moreover, at the communication windows of 1310 nm and 1550 nm, the corresponding filtering bandwidths are 170 and 550 nm, respectively. The flow chart of filter preparation reported in the study is promising for use in the field of optical devices.
Optical amplification for astronomical imaging at higher resolution
Authors: Gumpel Gal , Ribak Erez N.
Published: March 2021

Heisenberg’s uncertainty principle tells us that it is impossible to determine simultaneously the position of a photon crossing a telescope’s aperture and its momentum. Super-resolution imaging techniques rely on modification of the observed sample or on entangling photons. In astronomy, we have no access to the object, but resolution may be improved by optical amplification. Unfortunately, spontaneous emission contributes noise and negates the possible gain from stimulated emissions. We show that it is possible to increase the weight of the stimulated photons by considering photon statistics and observe an improvement in resolution. Most importantly, we demonstrate a method that can apply for all imaging purposes.
Digital compensation of imperfect pump counter-phasing induced phase distortion in optical phase conjugation of high-order QAM
Authors: Nguyen Tu T. , Boscolo Sonia , Ali Abdallah A. I. , Sygletos Stylianos , Takasaka Shigehiro , Sugizaki Ryuichi , Ellis Andrew D.
Published: March 2021

We propose a new two-stage digital signal processing scheme to suppress the phase distortion that arises from imperfect pump counter-phasing in a dual-pump fibre-based optical phase conjugation system. We demonstrate experimentally and numerically a signal-to-noise ratio improvement of more than 4 dB relative to conventional phase noise compensation, when the proposed scheme is used with 16/64/256 quadrature-amplitude modulation signals at pump-phase mismatch values as large as 8°.
Design and fabrication of high-performance multimode interferometer in lithium niobate thin film
Authors: Chen Guanyu , Ng Jun Da , Lin Hong-Lin , Zhang Gong , Gong Xiao , Danner Aaron J.
Published: March 2021

We propose and demonstrate a type of high-performance transverse magnetic (TM) multimode interferometer (MMI) in Z-cut thin film lithium niobate (TFLN). Both 1 × 2 and 4 × 4 MMI designs are demonstrated. Simulation results show that the insertion losses (ILs) are nominally about 0.157 and 0.297 dB for the 1 × 2 and 4 × 4 MMI, respectively, with wide fabrication tolerances. Based on the designed structure, the MMIs are fabricated using an argon based induced coupled plasma (ICP) etching method in Z-cut TFLN. The measured ILs are 0.268 and 0.63 dB for these two kinds of devices. The presented TM mode MMI featuring compact size and low loss can be used for both multifunctional devices and on-chip integrated circuits on a Z-cut TFLN platform.
Quantum detector tomography of a superconducting nanostrip photon-number-resolving detector
Authors: Endo Mamoru , Sonoyama Tatsuki , Matsuyama Mikihisa , Okamoto Fumiya , Miki Shigehito , Yabuno Masahiro , China Fumihiro , Terai Hirotaka , Furusawa Akira
Published: March 2021

Superconducting nanostrip photon detectors have been used as single-photon detectors, which can discriminate only photons’ presence or absence. It has recently been found that they can discriminate the number of photons by analyzing the output signal waveform, and they are expected to be used in various fields, especially in optical-quantum-information processing. Here, we improve the photon-number-resolving performance for light with a high-average photon number by pattern matching of the output signal waveform. Furthermore, we estimate the positive-operator-valued measure of the detector by a quantum detector tomography. The result shows that the device has photon-number-resolving performance up to five photons without any multiplexing or arraying, indicating that it is useful as a photon-number-resolving detector.
Observing quantum-path interference and Van Hove singularity in polarization-resolved high-harmonic spectroscopy
Authors: Du Tao-Yuan
Published: March 2021

High-harmonic spectra in solids driven by linearly polarized laser pulses contain diverse polarization dependence and fine modulation in the harmonic yields. In this work, we attribute the direction-dependent features of harmonic yields to the collective roles of tunneling rate, quantum-path interference, and joint density of state (JDOS). In addition, we distinguish the dominant contribution between quantum-path interference and the Van Hove singularity of JDOS, and demonstrate that the emergence of spectral enhancement in the vicinity of cutoff frequency is determined by the Van Hove singularity of JDOS. Polarization-resolved high-harmonic spectra are a promising spectroscopic tool to probe the electronic structure and dynamics in solids and thus open a door to measure Van Hove singularities and the energy band with high-resolution crystal momentum.
The oldest Homo erectus buried lithic horizon from the Eastern Saharan Africa. EDAR 7 - an Acheulean assemblage with Kombewa method from the Eastern Desert, Sudan
Authors: Masojć Mirosław , Kim Ju Yong , Krupa-Kurzynowska Joanna , Sohn Young Kwan , Ehlert Maciej , Michalec Grzegorz , Cendrowska Marzena , Andrieux Eric , Armitage Simon J. , Szmit Marcin , Dreczko Ewa , Kim Jin Cheul , Kim Ji Sung , Lee Gwang-Soo , Moska Piotr , Jadain Modather Abdalla
Published: March 2021

Although essential for reconstructing hominin behaviour during the Early Palaeolithic, only a handful of Acheulean sites have been dated in the Eastern Sahara region. This is due to the scarcity of sites for this time period and the lack of datable material. However, recent excavations in the Atbara region (Sudan) have provided unique opportunities to analyse and date Acheulean stone tools. We report here on EDAR 7, part of a cluster of Acheulean and Middle Stone Age (MSA) sites that were recently discovered in the Eastern Desert Atbara River (EDAR) region, located in the Eastern Desert (Sudan) far from the Nile valley. At EDAR 7, a 3.5 metre sedimentary sequence was excavated, allowing an Acheulean assemblage to be investigated using a combination of sedimentology, stone tool studies and optically stimulated luminescence dating (OSL). The site has delivered a complete Acheulean knappingchaine opératoire, providing new information about the Saharan Acheulean. The EDAR 7 site is interpreted as a remnant of a campsite based on the co-occurrence of two reduction modes: one geared towards the production of Large Cutting Tools (LCTs), and the other based on the flaking of small debitage and production of flake tools. Particularly notable in the EDAR 7 assemblage is the abundance of cleavers, most of which display evidence of flake production. Implementation of giant Kombewa flakes was also observed. A geometric morphometric analysis of hand-axes was conducted to verify a possible Late Acheulean assemblage standardisation in the Nubian Sahara. In addition, the analysis of micro-traces and wear on the artefacts has provided information on the use history of the Acheulean stone tools. Sediment analyses and OSL dating show that the EDAR 7 sequence contains the oldest Acheulean encampment remains in the Eastern Sahara, dated to the MIS 11 or earlier. This confirms thatHomo erectusoccupied the EDAR region during Middle Pleistocene humid periods, and demonstrates that habitable corridors existed between the Ethiopian Highlands, the Nile and the Red Sea coast, allowing population dispersals across the continent and out of it.
Validity and reliability of the Amharic version of the Schwartz Center Compassionate Care Scale
Authors: Zeray Merkeb , Mariam Damen Haile , Sahile Zekariyas , Hailu Alemayehu
Published: March 2021

Background

Compassionate care is the sensitivity shown by health care providers to understand another person’s suffering and a willingness to help and to promote the well being of that person. Although monitoring of compassionate care is key to ensuring patient-centered care, there is no validated tool in the Ethiopian context that can be applied to measure compassionate care. Therefore, this study aimed to assess the structural validity and reliability of the 12-item Schwartz Center Compassionate Care Scale® (SCCCS) in the Ethiopian context.

Methods

The structural validity and reliability of the 12-item Schwartz Center Compassionate Care Scale® were investigated in a sample of 423 oncology patients in the adult Oncology department of Tikur Anbessa Specialized Hospital in Addis Ababa, Ethiopia. The internal consistency of the instrument was examined based on Cronbach’s alpha coefficient, and the structural validity was evaluated by subjecting the items of the instrument to factor analysis. Statistical analysis was made using SPSS version 23.0.

Results

We have found that the Schwartz Center Compassionate Care scale is a two-factor structure (recognizing suffering and acting to relieve suffering). The scale has high overall scale reliability, which was 0.88, and subscale reliability of 0.84 for both recognizing suffering and acting to relieve suffering factors.

Conclusions

The Schwartz Center Compassionate Care Scale has high internal consistency and acceptable structural validity value. The tool can be used to measure compassionate care practice in the Ethiopian context.
Developing and validating an individualized breast cancer risk prediction model for women attending breast cancer screening
Authors: Louro Javier , Román Marta , Posso Margarita , Vázquez Ivonne , Saladié Francina , Rodriguez-Arana Ana , Quintana M. Jesús , Domingo Laia , Baré Marisa , Marcos-Gragera Rafael , Vernet-Tomas María , Sala Maria , Castells Xavier ,   on behalf of the BELE and IRIS Study Groups
Published: March 2021

Background

Several studies have proposed personalized strategies based on women’s individual breast cancer risk to improve the effectiveness of breast cancer screening. We designed and internally validated an individualized risk prediction model for women eligible for mammography screening.

Methods

Retrospective cohort study of 121,969 women aged 50 to 69 years, screened at the long-standing population-based screening program in Spain between 1995 and 2015 and followed up until 2017. We used partly conditional Cox proportional hazards regression to estimate the adjusted hazard ratios (aHR) and individual risks for age, family history of breast cancer, previous benign breast disease, and previous mammographic features. We internally validated our model with the expected-to-observed ratio and the area under the receiver operating characteristic curve.

Results

During a mean follow-up of 7.5 years, 2,058 women were diagnosed with breast cancer. All three risk factors were strongly associated with breast cancer risk, with the highest risk being found among women with family history of breast cancer (aHR: 1.67), a proliferative benign breast disease (aHR: 3.02) and previous calcifications (aHR: 2.52). The model was well calibrated overall (expected-to-observed ratio ranging from 0.99 at 2 years to 1.02 at 20 years) but slightly overestimated the risk in women with proliferative benign breast disease. The area under the receiver operating characteristic curve ranged from 58.7% to 64.7%, depending of the time horizon selected.

Conclusions

We developed a risk prediction model to estimate the short- and long-term risk of breast cancer in women eligible for mammography screening using information routinely reported at screening participation. The model could help to guiding individualized screening strategies aimed at improving the risk-benefit balance of mammography screening programs.