bluuebunny/crossref_metadata_2025 huggingface dataset:
Differential effects of chronic immunosuppression on behavioral, epigenetic, and Alzheimer’s disease-associated markers in 3xTg-AD mice
Authors: Kapadia Minesh , Mian M. Firoz , Ma Donglai , Hutton Craig P. , Azam Amber , Narkaj Klotilda , Cao Chuanhai , Brown Breanna , Michalski Bernadeta , Morgan David , Forsythe Paul , Zovkic Iva B. , Fahnestock Margaret , Sakic Boris
Published: January 2021

Background

Circulating autoantibodies and sex-dependent discrepancy in prevalence are unexplained phenomena of Alzheimer’s disease (AD). Using the 3xTg-AD mouse model, we reported that adult males show early manifestations of systemic autoimmunity, increased emotional reactivity, enhanced expression of the histone variant macroH2A1 in the cerebral cortex, and loss of plaque/tangle pathology. Conversely, adult females display less severe autoimmunity and retain their AD-like phenotype. This study examines the link between immunity and other traits of the current 3xTg-AD model.

Methods

Young 3xTg-AD and wild-type mice drank a sucrose-laced 0.4 mg/ml solution of the immunosuppressant cyclophosphamide on weekends for 5 months. After behavioral phenotyping at 2 and 6 months of age, we assessed organ mass, serologic markers of autoimmunity, molecular markers of early AD pathology, and expression of genes associated with neurodegeneration.

Results

Chronic immunosuppression prevented hematocrit drop and reduced soluble Aβ in 3xTg-AD males while normalizing the expression of histone variant macroH2A1 in 3xTg-AD females. This treatment also reduced hepatosplenomegaly, lowered autoantibody levels, and increased the effector T cell population while decreasing the proportion of regulatory T cells in both sexes. Exposure to cyclophosphamide, however, neither prevented reduced brain mass and BDNF expression nor normalized increased tau and anxiety-related behaviors.

Conclusion

The results suggest that systemic autoimmunity increases soluble Aβ production and affects transcriptional regulation of macroH2A1 in a sex-related manner. Despite the complexity of multisystem interactions, 3xTg-AD mice can be a useful in vivo model for exploring the regulatory role of autoimmunity in the etiology of AD-like neurodegenerative disorders.
Exponential stability for delayed complex-valued neural networks with reaction-diffusion terms
Authors: Xu Xiaohui , Yang Jibin , Xu Quan , Xu Yanhai , Sun Shulei
Published: January 2021

In this study, we investigate reaction-diffusion complex-valued neural networks with mixed delays. The mixed delays include both time-varying and infinite distributed delays. Criteria are derived to ensure the existence, uniqueness, and exponential stability of the equilibrium state of the addressed system on the basis of the M-matrix properties and homeomorphism mapping theories as well as the vector Lyapunov function method. The results demonstrate the positive effect of reaction-diffusion on the stability, which further improves the existing conditions. Finally, the analysis of several examples is compared to the present results to verify the correctness and reduced conservatism of the primary results.
Modeling and forecasting the spread of COVID-19 with stochastic and deterministic approaches: Africa and Europe
Authors: Atangana Abdon , İğret Araz Seda
Published: January 2021

Using the existing collected data from European and African countries, we present a statistical analysis of forecast of the future number of daily deaths and infections up to 10 September 2020. We presented numerous statistical analyses of collected data from both continents using numerous existing statistical theories. Our predictions show the possibility of the second wave of spread in Europe in the worse scenario and an exponential growth in the number of infections in Africa. The projection of statistical analysis leads us to introducing an extended version of the well-blancmange function to further capture the spread with fractal properties. A mathematical model depicting the spread with nine sub-classes is considered, first converted to a stochastic system, where the existence and uniqueness are presented. Then the model is extended to the concept of nonlocal operators; due to nonlinearity, a modified numerical scheme is suggested and used to present numerical simulations. The suggested mathematical model is able to predict two to three waves of the spread in the near future.
Current plastics pollution threats due to COVID-19 and its possible mitigation techniques: a waste-to-energy conversion via Pyrolysis
Authors: Aragaw Tadele Assefa , Mekonnen Bassazin Ayalew
Published: January 2021

Background

The extensive use and production of PPE, and disposal in the COVID-19 pandemic increases the plastic wastes arise environmental threats. Roughly, 129 billion face masks and 65 billion plastic gloves every month are used and disposed of on the globe. The study aims to identify the polymer type of face masks and gloves and sustainable plastic waste management options.

Results

The identification of polymers, which can help for fuel conversion alternatives, was confirmed by FTIR and TGA/DTA analysis and confirms that the polymeric categories fit for the intended purpose. Moreover, the handling technique for upcycling and the environmental impacts of the medical face mask and glove were discussed. The FTIR result revealed that face masks and gloves are polypropylene and PVC thermoplastic polymer, respectively and they can be easily transformed to fuel energy via pyrolysis. The endothermic peaks around 431 ℃ for medical glove and 175 ℃ for surgical is observed tells that the melting point of the PVC and polypropylene of plastic polymers, respectively. The pyrolysis of the face mask and glove was carried out in a closed reactor at 400 ℃ for 1 h. Conferring to lab-scale processes, liquid, and wax fuel rate of 75%, char of 10%, and the rest non-condensable gases were estimated at the end.

Conclusions

It can be concluded that the medical plastics can be recycled into oil due to their thermoplastics nature having high oil content and the waste to energy conversion can potentially reduce the volume of PPE plastic wastes.
Understanding the host-microbe interactions using metabolic modeling
Authors: Jansma Jack , El Aidy Sahar
Published: January 2021

The human gut harbors an enormous number of symbiotic microbes, which is vital for human health. However, interactions within the complex microbiota community and between the microbiota and its host are challenging to elucidate, limiting development in the treatment for a variety of diseases associated with microbiota dysbiosis. Using in silico simulation methods based on flux balance analysis, those interactions can be better investigated. Flux balance analysis uses an annotated genome-scale reconstruction of a metabolic network to determine the distribution of metabolic fluxes that represent the complete metabolism of a bacterium in a certain metabolic environment such as the gut. Simulation of a set of bacterial species in a shared metabolic environment can enable the study of the effect of numerous perturbations, such as dietary changes or addition of a probiotic species in a personalized manner. This review aims to introduce to experimental biologists the possible applications of flux balance analysis in the host-microbiota interaction field and discusses its potential use to improve human health.
Improved effect of a mitochondria-targeted antioxidant on hydrogen peroxide-induced oxidative stress in human retinal pigment epithelium cells
Authors: Kim Myung Hee , Kim Do-Hun , Yang Su Geun , Kim Dae Yu
Published: January 2021

Background

Oxidative damage to retinal pigment epithelial (RPE) cells contributes to the development of age-related macular degeneration, which is among the leading causes of visual loss in elderly people. In the present study, we evaluated the protective role of triphenylphosphonium (TPP)-Niacin against hydrogen peroxide (H2O2)-induced oxidative stress in RPE cells.

Methods

The cellular viability, lactate dehydrogenase release, reactive oxygen species (ROS) generation, and mitochondrial function of retinal ARPE-19 cells were determined under treatment with H2O2 or pre-treatment with TPP-Niacin. The expression level of mitochondrial related genes and some transcription factors were assessed using real-time polymerase chain reaction (RT-qPCR).

Results

TPP-Niacin significantly improved cell viability, reduced ROS generation, and increased the antioxidant enzymes in H2O2-treated ARPE-19 cells. Mitochondrial dysfunction from the H2O2-induced oxidative stress was also considerably diminished by TPP-Niacin treatment, along with reduction of the mitochondrial membrane potential (MMP) and upregulation of the mitochondrial-associated gene. In addition, TPP-Niacin markedly enhanced the expression of transcription factors (PGC-1α and NRF2) and antioxidant-associated genes (especially HO-1 and NQO-1).

Conclusion

We verified the protective effect of TPP-Niacin against H2O2-induced oxidative stress in RPE cells. TPP-Niacin is believed to protect against mitochondrial dysfunction by upregulating antioxidant-related genes, such as PGC-1α, NRF2, HO-1, and NQO-1, in RPE cells.
Winter fidelity, movements, and energy expenditure of Midcontinent Greater White-fronted Geese
Authors: VonBank Jay A. , Weegman Mitch D. , Link Paul T. , Cunningham Stephanie A. , Kraai Kevin J. , Collins Daniel P. , Ballard Bart M.
Published: January 2021

Background

Animal movement patterns are the result of both environmental and physiological effects, and the rates of movement and energy expenditure of given movement strategies are influenced by the physical environment an animal inhabits. Greater white-fronted geese in North America winter in ecologically distinct regions and have undergone a large-scale shift in wintering distribution over the past 20 years. White-fronts continue to winter in historical wintering areas in addition to contemporary areas, but the rates of movement among regions, and energetic consequences of those decisions, are unknown. Additionally, linkages between wintering and breeding regions are generally unknown, and may influence within-winter movement rates.

Methods

We used Global Positioning System and acceleration data from 97 white-fronts during two winters to elucidate movement characteristics, model regional transition probabilities using a multistate model in a Bayesian framework, estimate regional energy expenditure, and determine behavior time-allocation influences on energy expenditure using overall dynamic body acceleration and linear mixed-effects models. We assess the linkages between wintering and breeding regions by evaluating the winter distributions for each breeding region.

Results

White-fronts exhibited greater daily movement early in the winter period, and decreased movements as winter progressed. Transition probabilities were greatest towards contemporary winter regions and away from historical wintering regions. Energy expenditure was up to 55% greater, and white-fronts spent more time feeding and flying, in contemporary wintering regions compared to historical regions. White-fronts subsequently summered across their entire previously known breeding distribution, indicating substantial mixing of individuals of varying breeding provenance during winter.

Conclusions

White-fronts revealed extreme plasticity in their wintering strategy, including high immigration probability to contemporary wintering regions, high emigration from historical wintering regions, and high regional fidelity to western regions, but frequent movements among eastern regions. Given that movements of white-fronts trended toward contemporary wintering regions, we anticipate that a wintering distribution shift eastward will continue. Unexpectedly, greater energy expenditure in contemporary wintering regions revealed variable energetic consequences of choice in wintering region and shifting distribution. Because geese spent more time feeding in contemporary regions than historical regions, increased energy expenditure is likely balanced by increased energy acquisition in contemporary wintering areas.
Drug supply situation in Rwanda during COVID-19: issues, efforts and challenges
Authors: Uwizeyimana Theogene , Hashim Hashim Talib , Kabakambira Jean Damascene , Mujyarugamba Jean Claude , Dushime Jackson , Ntacyabukura Blaise , Ndayizeye Remy , Adebisi Yusuff Adebayo , Lucero-Prisno Don Eliseo
Published: January 2021

COVID-19 is a threat to health systems around the world and Rwanda is not an exception. The impact of the pandemic is far-reaching and access to health commodities is not spared. Proper drug supply is critical for a robust healthcare system. It determines the extent at which the population are likely to have access to essential medicines and treatments. In Rwanda, the pharmaceutical sector heavily relies on imports. With the emergence of COVID-19 pandemic, the drug supply system was interrupted leaving many stores from small local pharmacies to the big medical stores running out of stock. The reasons were limited importation of goods from abroad, and the panic buying practice among the customers and some institutions when responding to the pandemic. Drug and medicines accessibility, availability and affordability should be the core of any drug management policy. It is with no doubt that, Rwanda has made a tremendous work to mitigate the effect of COVID-19 on the country’s drug supply; however, efforts are still needed to invest in local pharmaceutical production as a way to minimize import expenses in the country. Good policy on drug importation, production and distribution should be enforced to avoid any drug shortage that may be encountered in the Rwandan drug market.
Advanced echocardiographic phenotyping of critically ill patients with coronavirus-19 sepsis: a prospective cohort study
Authors: Bagate François , Masi Paul , d’Humières Thomas , Al-Assaad Lara , Chakra Laure Abou , Razazi Keyvan , de Prost Nicolas , Carteaux Guillaume , Derumeaux Genevieve , Mekontso Dessap Armand
Published: January 2021

Background

Sepsis is characterized by various hemodynamic alterations which could happen concomitantly in the heart, pulmonary and systemic circulations. A comprehensive demonstration of their interactions in the clinical setting of COVID-19 sepsis is lacking. This study aimed at evaluating the feasibility, clinical implications, and physiological coherence of the various indices of hemodynamic function and acute myocardial injury (AMI) in COVID-19 sepsis.

Methods

Hemodynamic and echocardiographic data of septic critically ill COVID-19 patients were prospectively recorded. A dozen hemodynamic indices exploring contractility and loading conditions were assessed. Several cardiac biomarkers were measured, and AMI was considered if serum concentration of high-sensitive troponin T (hs-TNT) was above the 99th percentile, upper reference.

Results

Sixty-seven patients were assessed (55 males), with a median age of 61 [50–70] years. Overall, the feasibility of echocardiographic parameters was very good, ranging from 93 to 100%. Hierarchical clustering method identified four coherent clusters involving cardiac preload, left ventricle (LV) contractility, LV afterload, and right ventricle (RV) function. LV contractility indices were not associated with preload indices, but some of them were positively correlated with RV function parameters and negatively correlated with a single LV afterload parameter. In most cases (n = 36, 54%), echocardiography results prompted therapeutic changes. Mortality was not influenced by the echocardiographic variables in multivariable analysis. Cardiac biomarkers’ concentrations were most often increased with high incidence of AMI reaching 72%. hs-TNT was associated with mortality and inversely correlated with most of LV and RV contractility indices.

Conclusions

In this comprehensive hemodynamic evaluation in critically ill COVID-19 septic patients, we identified four homogeneous and coherent clusters with a good feasibility. AMI was common and associated with alteration of LV and RV functions. Echocardiographic assessment had a clinical impact on patient management in most cases.
COVID-19 associated acute demyelination masquerading as stroke: a case report
Authors: Khandelwal Krati , Puranik Monika , Gupta Vivek , Khandelwal Gaurav , Dave Pranav Kumar , Hirve Makarand
Published: January 2021

Background

During the recent outbreak of COVID-19, various atypical extrapulmonary manifestations are being seen, including neurological ones. Reported cases mainly include encephalopathy, myelitis, and cranial nerve involvement. This case describes uncommon neuroradiological finding in the context of COVID-19.

Case presentation

We report an atypical case of COVID-19 presenting with stroke-like episode, with MRI brain showing isolated bilateral posterior internal capsule involvement. This has rarely been reported in literature.

Conclusion

As the numbers of COVID-19 cases are increasing, such atypical presentations should be kept in mind.
Interpolation method based on pattern-feature correlation
Authors: Yu Bo , Zhou Hui , Liu Wenling , Wang Lingqian , Chen Hanming
Published: January 2021

Reasonable low-wavenumber initial models are essential for reducing the nonuniqueness of seismic inversion. A traditional approach to estimate the low-wavenumber models of elastic parameters is well-log interpolation. However, complex geologic structures decrease the accuracy of this method. To overcome these challenges in building prior models, we have developed an interpolation method based on pattern-feature correlation (PFC) inspired by multiple-point geostatistics (MPG). In our interpolation method, we scan a stacked seismic profile using a predefined data template to obtain a geologic pattern around each node in the seismic profile. Each pattern is then converted into several filter scores with the filters defined in the MPG algorithm of the filter-based simulation. We calculate the correlation coefficients of the filter scores among different patterns for the various nodes and define them as PFCs. We construct the initial models from well-log data based on the weighted interpolation method, in which the weighting factors are precisely determined by the PFCs. We build the initial models using our method for synthetic and field data to demonstrate its effectiveness. To verify the validity of the initial models, we apply them to Bayesian linearized inversion. The accuracy of the interpolation and inversion results verifies the excellent performance of our interpolation method. Our method provides a novel and convenient approach that combines seismic and well-log data, which contributes to seismic exploration and geologic modeling.
On the pseudospectral method and spectral accuracy
Authors: Mittet Rune
Published: January 2021

There are numerical accuracy problems related to the implementation of sharp internal interfaces in pseudospectral and finite-difference schemes. It is common practice to classify numerical errors due to the implementation of interfaces as being to some order in a Taylor expansion. An alternative approach is to classify these errors as being to some order in a Fourier expansion. The pseudospectral method does not provide spectral accuracy in inhomogeneous media. The numerical errors for the upper half of the frequency/wavenumber spectra of the propagating fields are not related to the implementation of the derivative operators but to aliasing effects coming from the multiplication of static material-parameter fields with the dynamic propagating fields. The pseudospectral method can only provide half-spectral accuracy. The same type of spatial aliasing errors is also present for finite-difference schemes. High-order finite differences can provide the same accuracy as the pseudospectral method if the staggered finite-difference derivative operators have a negligible error at four grid points per shortest wavelength and above. Smoothing of the material-parameter field leads to additional reduction in the error-free bandwidth of the propagating fields. Assuming that there is a maximum wavenumber up to which the spectrum of the smoothed model coincides with the implementation using a properly band-limited Heaviside step function, then there exists a local critical wavenumber for the propagating field equal to one half of the maximum wavenumber for the smoothed model. Harmonic averaging of material-parameter fields also results in wavenumber spectra where there is a maximum wavenumber above which the wavenumber spectrum deviates from an implementation with a band-limited Heaviside step function. The same one-half rule is also applicable in this case.
Focal Boost to the Intraprostatic Tumor in External Beam Radiotherapy for Patients With Localized Prostate Cancer: Results From the FLAME Randomized Phase III Trial
Authors: Kerkmeijer Linda G. W. , Groen Veerle H. , Pos Floris J. , Haustermans Karin , Monninkhof Evelyn M. , Smeenk Robert Jan , Kunze-Busch Martina , de Boer Johannes C. J. , van der Voort van Zijp Jochem , van Vulpen Marco , Draulans Cédric , van den Bergh Laura , Isebaert Sofie , van der Heide Uulke A.
Published: January 2021

PURPOSE

This study investigates whether focal boosting of the macroscopic visible tumor with external beam radiotherapy increases biochemical disease-free survival (bDFS) in patients with localized prostate cancer.

PATIENTS AND METHODS

In the phase III, multicenter, randomized controlled Focal Lesion Ablative Microboost in Prostate Cancer trial, 571 patients with intermediate- and high-risk prostate cancer were enrolled between 2009 and 2015. Patients assigned to standard treatment received 77 Gy (fractions of 2.2 Gy) to the entire prostate. The focal boost arm received an additional simultaneous integrated focal boost up to 95 Gy (fractions up to 2.7 Gy) to the intraprostatic lesion visible on multiparametric magnetic resonance imaging. Organ at risk constraints were prioritized over the focal boost dose. The primary end point was 5-year bDFS. Secondary end points were disease-free survival (DFS), distant metastases-free survival, prostate cancer-specific survival, overall survival, toxicity, and health-related quality of life.

RESULTS

Median follow-up was 72 months. Biochemical DFS was significantly higher in the focal boost compared with the standard arm (hazard ratio 0.45, 95% CI, 0.28 to 0.71, P < .001). At 5-year follow-up bDFS was 92% and 85%, respectively. We did not observe differences in prostate cancer-specific survival ( P = .49) and overall survival ( P = .50). The cumulative incidence of late genitourinary and GI toxicity grade ≥ 2 was 23% and 12% in the standard arm versus 28% and 13% in the focal boost arm, respectively. Both for late toxicity as health-related quality of life, differences were small and not statistically significant.

CONCLUSION

The addition of a focal boost to the intraprostatic lesion improved bDFS for patients with localized intermediate- and high-risk prostate cancer without impacting toxicity and quality of life. The Focal Lesion Ablative Microboost in Prostate Cancer study shows that a high focal boost strategy to improve tumor control while respecting organ at risk dose constraints is effective and safe.
Harnessing brain development to understand brain tumours
Authors: Marino Silvia , Gilbertson Richard J.
Published: January 2021

Brain tumours are the commonest solid neoplasms in children, accounting for one quarter of all childhood cancers. Our growing knowledge of basic developmental mechanisms has significantly contributed to understanding the pathogenesis of these tumours and is beginning to impact clinical decisions on how children with these diseases are treated.
Oxygen regulates epithelial stem cell proliferation via RhoA-actomyosin-YAP/TAZ signal in mouse incisor
Authors: Otsu Keishi , Ida-Yonemochi Hiroko , Ikezaki Shojiro , Ema Masatsugu , Hitomi Jiro , Ohshima Hayato , Harada Hidemitsu
Published: January 2021

Stem cells are maintained in specific niches that strictly regulate their proliferation and differentiation for proper tissue regeneration and renewal. Molecular oxygen (O2) is an important component of the niche microenvironment, but little is known about how O2 governs epithelial stem cell (ESC) behavior. Here, we demonstrate that O2 plays a crucial role in regulating the proliferation of ESCs using the continuously growing mouse incisors. We have revealed that slow-cycling cells in the niche are maintained under relatively hypoxic conditions compared with actively proliferating cells, based on the blood vessel distribution and metabolic status. Mechanistically, we have demonstrated that, during hypoxia, HIF1α upregulation activates the RhoA signal, thereby promoting cortical actomyosin and stabilizing the adherens junction complex, including merlin. This leads to the cytoplasmic retention of YAP/TAZ to attenuate cell proliferation. These results shed light on the biological significance of blood-vessel geometry and the signaling mechanism through microenvironmental O2 to orchestrate ESC behavior, providing a novel molecular basis for the microenvironmental O2-mediated stem cell regulation during tissue development and renewal.
Robustness and timing of cellular differentiation through population-based symmetry breaking
Authors: Stanoev Angel , Schröter Christian , Koseska Aneta
Published: January 2021

During mammalian development and homeostasis, cells often transition from a multilineage primed state to one of several differentiated cell types that are marked by the expression of mutually exclusive genetic markers. These observations have been classically explained by single-cell multistability as the dynamical basis of differentiation, where robust cell-type proportioning relies on pre-existing cell-to-cell differences. We propose a conceptually different dynamical mechanism in which cell types emerge and are maintained collectively by cell-cell communication as a novel inhomogeneous state of the coupled system. Differentiation can be triggered by cell number increase as the population grows in size, through organisation of the initial homogeneous population before the symmetry-breaking bifurcation point. Robust proportioning and reliable recovery of the differentiated cell types following a perturbation is an inherent feature of the inhomogeneous state that is collectively maintained. This dynamical mechanism is valid for systems with steady-state or oscillatory single-cell dynamics. Therefore, our results suggest that timing and subsequent differentiation in robust cell-type proportions can emerge from the cooperative behaviour of growing cell populations during development.
Frequency and characterization of ancillary chest CT findings in COVID-19 pneumonia
Authors: Silva Mario , Ledda Roberta Eufrasia , Schiebler Mark , Balbi Maurizio , Sironi Sandro , Milone Francesca , Affanni Paola , Milanese Gianluca , Sverzellati Nicola
Published: January 2021

Objectives:

Ground-glass opacity and consolidation are recognized typical features of Coronavirus disease-19 (COVID-19) pneumonia on Chest CT, yet ancillary findings have not been fully described. We aimed to describe ancillary findings of COVID-19 pneumonia on CT, to define their prevalence, and investigate their association with clinical data.

Methods:

We retrospectively reviewed our CT chest cases with coupled reverse transcriptase polymerase chain reaction (rt-PCR). Patients with negative rt-PCR or without admission chest CT were excluded. Ancillary findings included: vessel enlargement, subpleural curvilinear lines, dependent subpleural atelectasis, centrilobular solid nodules, pleural and/or pericardial effusions, enlarged mediastinal lymph nodes. Continuous data were expressed as median and 95% confidence interval (95% CI) and tested by Mann–Whitney U test.

Results:

Ancillary findings were represented by 106/252 (42.1%, 36.1 to 48.2) vessel enlargement, 50/252 (19.8%, 15.4 to 25.2) subpleural curvilinear lines, 26/252 (10.1%, 7.1 to 14.7) dependent subpleural atelectasis, 15/252 (5.9%, 3.6 to 9.6) pleural effusion, 15/252 (5.9%, 3.6 to 9.6) mediastinal lymph nodes enlargement, 13/252 (5.2%, 3 to 8.6) centrilobular solid nodules, and 6/252 (2.4%, 1.1 to 5.1) pericardial effusion. Air space disease was more extensive in patients with vessel enlargement or centrilobular solid nodules (p < 0.001). Vessel enlargement was associated with longer history of fever (p = 0.035) and lower admission oxygen saturation (p = 0.014); dependent subpleural atelectasis with lower oxygen saturation (p < 0.001) and higher respiratory rate (p < 0.001); mediastinal lymph nodes with shorter history of cough (p = 0.046); centrilobular solid nodules with lower prevalence of cough (p = 0.023), lower oxygen saturation (p < 0.001), and higher respiratory rate (p = 0.032), and pericardial effusion with shorter history of cough (p = 0.015). Ancillary findings associated with longer hospital stay were subpleural curvilinear lines (p = 0.02), whereas centrilobular solid nodules were associated with higher rate of intensive care unit admission (p = 0.01).

Conclusion:

Typical high-resolution CT findings of COVID-19 pneumonia are frequently associated with ancillary findings that variably associate with disease extent, clinical parameters, and disease severity.

Advances in knowledge:

Ancillary findings might reflect the broad range of heterogeneous mechanisms in severe acute respiratory syndrome from viral pneumonia, and potentially help disease phenotyping.
Speech therapy technologies
Authors: Azova Ol'ga , D'yakova Elena , Antipova Zhanna , Vorob'eva Mariya
Published: January 2021

The textbook discusses the features of the formation of speech and motor functions in children, as well as their disorders. Technologies of examination of the pronouncing side of speech, lexical and grammatical structure of language and coherent speech, tempo-rhythmic organization of speech and motor functions in children are presented. The methods and techniques of diagnostics, criteria for assessing the violation of the formation of functions are described in detail. Meets the requirements of the federal state educational standards of higher education of the latest generation. For students of higher educational institutions studying in the direction of training 44.03.03 "Special (defectological) education" (bachelor's level). It may be useful for undergraduate students studying in the areas of training 44.03.02 "Psychological and pedagogical education" and 44.03.01 "Pedagogical education" - future primary school teachers. It is recommended for the examination of all components of speech and motor functions in children with various disorders.
Relay protection and automation of electric power systems
Authors: Goremykin Sergey
Published: January 2021

The textbook describes the main issues of the theory of relay protection and automation of electric power systems. The structure and functional purpose of protection devices and automation of power transmission lines of various configurations, synchronous generators, power transformers, electric motors and individual electrical installations are considered. For each of the types of protection of the above objects, the structure, the principle of operation, the order of selection of settings are given, the advantages and disadvantages are evaluated, indicating the scope of application. The manual includes material on complete devices based on semiconductor and microprocessor element bases. The progressive use of such devices (protection of the third and fourth generations) is appropriate and effective due to their significant advantages. Meets the requirements of the federal state educational standards of higher education of the latest generation. It is intended for students in the areas of training 13.03.02 "Electric power and electrical engineering" (profile "Power supply", discipline "Relay protection and automation of electric power systems") and 35.03.06 "Agroengineering" (profile "Power supply and electrical equipment of agricultural enterprises", discipline "Relay protection of electrical equipment of agricultural objects"), as well as for graduate students and specialists engaged in the field of electrification and automation of industrial and agrotechnical objects.
Subunit Principle: Key Element for Plantar Reconstruction with Free Sensate Flaps
Authors: Sanchez Blanca Yadira Arambula , Gallardo Daniel De Luna , Espinoza Jaime Aron Garcia , Soto David Flores
Published: January 2021

Purpose: Plantar wounds represent a frequent practice of the plastic and reconstructive surgeon. The uniqueness and high complexity of the microarchitecture and biomechanics of the plantar region explain the complex challenge of its reconstruction. With the advances in microsurgery, including the plantar subunit principle, both applied in the restoration of plantar defects through the use of sensorineural free flaps have allowed an optimal reconstruction.Methods: A descriptive, retrospective study was carried out in a period of time established between January 2016 and January 2019, obtaining a total of 18 patients with plantar defects, reconstructed using sensory free flaps. Tissue stability, recovery of protective sensitivity, early ambulation, and correct use of footwear were evaluated.Results: The most frequent etiology was secondary to oncological resections due to melanoma (n = 12, 66.7%), followed by gunshot wounds (n = 4, 22.2%). Subunit 3 was the most frequently involved in 38.9% (n = 7). In the 88.8% of the cases, was used an anterolateral thigh flap (n = 16) and the lateral antebrachial flap in 22.2% (n = 2). The free flap survival rate was 100%. An average of seven points was obtained at 6 months based on the Semmes-Weinstein test. The mean for the return to their daily activities was 2.5 months. The patients of 94.4% (n = 17) recovered ambulation and could footwear. Conclusion: The reconstruction of plantar defects must have a systematic approached, taking the subunit principle as a central point. The treatment of plantar defects with sensorineural free flaps represent an unprecedented option for optimal reconstruction.
Modeling and Solving the Intersection Inspection Rural Postman Problem
Authors: Sinha Roy Debdatta , Masone Adriano , Golden Bruce , Wasil Edward
Published: January 2021

Local governments inspect roads to decide which segments and intersections to repair. Videos are taken using a camera mounted on a vehicle. The vehicle taking the videos proceeds straight or takes a left turn to cover an intersection fully. We introduce the intersection inspection rural postman problem (IIRPP), which is a new variant of the rural postman problem (RPP) that involves turns. We develop integer programming formulations of the IIRPP based on two different graph transformations to generate least-cost vehicle routes. One formulation is based on a new idea of transforming a graph. A second formulation is based on a graph transformation idea from the literature. Computational experiments show that the formulation involving the new graph transformation idea performs much better than the other formulation. We also develop an RPP-based heuristic and a heuristic based on a modified RPP. Heuristic solutions are improved by solving integer programming formulations on an induced subgraph. Computational experiments show that the heuristics based on the modified RPP perform much better than the RPP-based heuristics. The best-performing heuristic generates very good quality IIRPP-feasible routes on large street networks quickly.

Summary of Contribution. Our paper addresses a real-world problem faced by local governments during road inspections. The real-world problem that we solve and the methodologies that we use fall at the intersection of computing and operations research. We introduce the intersection inspection rural postman problem, which is a new variant of the rural postman problem that involves turns to capture this real-world scenario. The rural postman problem is an important problem in vehicle routing. Studying new variants of this problem is key to extending the practice and theory of vehicle routing. We develop an integer programming formulation based on a new idea of transforming a graph and also develop heuristics based on the rural postman problem.
The Power of Opaque Products in Pricing
Authors: Elmachtoub Adam N. , Hamilton Michael L.
Published: January 2021

We study the power of selling opaque products, that is, products where a feature (such as color) is hidden from the customer until after purchase. Opaque products, which are sold with a price discount, have emerged as a powerful vehicle to increase revenue for many online retailers and service providers that offer horizontally differentiated items. In the opaque selling models we consider, all of the items are sold at a single common price alongside opaque products that may correspond to various subsets of the items. We consider two types of customers, risk-neutral ones, who assume they will receive a truly random item of the opaque product, and pessimistic ones, who assume they will receive their least favorite item of the opaque product. We benchmark opaque selling against two common selling strategies: discriminatory pricing, where one explicitly charges different prices for each item, and single pricing, where a single price is charged for all the items. We give a sharp characterization of when opaque selling outperforms discriminatory pricing; namely, this result holds for situations where all customers are pessimistic or the item valuations are supported on two points. In the latter case, we also show that opaque selling with just one opaque product guarantees at least 71.9% of the revenue from discriminatory pricing. We then provide upper bounds on the potential revenue increase from opaque selling strategies over single pricing and describe cases where the increase can be significantly more than that of discriminatory pricing. Finally, we provide pricing algorithms and conduct an extensive numerical study to assess the power of opaque selling for a variety valuation distributions and model extensions.

This paper was accepted by Gabriel Weintraub, revenue management and market analytics.
Points Gained in Football: Using Markov Process-Based Value Functions to Assess Team Performance
Authors: Chan Timothy C. Y. , Fernandes Craig , Puterman Martin L.
Published: January 2021

A Theoretical Foundation for Value Functions in Sports
Do Startup Employees Earn More in the Long Run?
Authors: Sorenson Olav , Dahl Michael S. , Canales Rodrigo , Burton M. Diane
Published: January 2021

Evaluating the attractiveness of startup employment requires an understanding of both what startups pay and the implications of these jobs for earnings trajectories. Analyzing Danish registry data, we find that employees hired by startups earn roughly 17% less over the next 10 years than those hired by large, established firms. About half of this earnings differential stems from sorting—from the fact that startup employees have less human capital. Long-term earnings also vary depending on when individuals are hired. Although the earliest employees of startups suffer an earnings penalty, those hired by already-successful startups earn a small premium. Two factors appear to account for the earnings penalties for the early employees: Startups fail at high rates, creating costly spells of unemployment for their (former) employees. Job-mobility patterns also diverge: After being employed by a small startup, individuals rarely return to the large employers that pay more.
Staying Alive: Toward a Diverging Consensus Model of Overcoming a Bias Against Novelty in Groups
Authors: Harvey Sarah , Mueller Jennifer S.
Published: January 2021

Organizations that desire creativity often use groups like task forces, decision panels, and selection committees with the primary purpose of evaluating novel ideas. Those groups need to keep at least some novel ideas alive while also assessing the usefulness of ideas. Research suggests, however, that such groups often prefer proven ideas whose usefulness can be easily predicted and reject novel ideas early in the course of discussion. How those groups deal with the tension between novelty and the predictability of idea usefulness in the process of overcoming a bias against novelty is therefore an important question for understanding organizational creativity and innovation. We explore that question with a qualitative study of the discussions of four healthcare policy groups who confronted the tension early in the process of evaluating ideas. Unlike prior work that emphasizes how groups integrate tensions to build consensus around ideas, our study showed that overcoming a bias against novelty involved maintaining tension by fracturing a group’s shared understanding of usefulness and retaining those divergent perspectives alongside moments of consensus. We describe this as a diverging consensus model of overcoming a bias against novelty. Our work contributes to the literature examining how groups can productively engage with tensions and provides a dynamic process for how groups might overcome the bias against novelty and therefore keep some novel ideas alive to fuel organizational creativity and innovation.
Effect of the Ba/K ratio on structural, dielectric and energy storage properties of BaO–K2O–TiO2–P2O5 glass-ceramics
Authors:   Faculté des Sciences de Meknès, Haily E. , Bih L. , El Bouari A. , Lahmar A. , El Marssi M. , Manoun B. ,   Université Moulay Ismail,   Faculté des Sciences Ben M’sik Casablanca,   University of Picardie Jules Verne,   Université Hassan 1er,   Mohammed VI Polytechnic University
Published: January 2021

xBaO–(20−x)K2O–30TiO2–50P2O5 with (0≤x≤20 mol%) glasses were successfully elaborated by the melt quenching while their related glass-ceramics were developed by controlled crystallisation. Density and molar volume measurements, differential thermal analysis and Raman spectroscopy were carried out to examine the glassy structure, the results revealed that the addition of BaO increases the reticulation and reinforces the glass network by the creation of strengthened linkages. X-ray diffraction has identified the formation of MTi2(PO4)3 with M=(K, Ba0·5) in all the glass-ceramics (GC) and the precipitation of a secondary BaTiP2O8 phase when x increase beyond 10 mol%. The dielectric properties of the glass-ceramics were studied by impedance spectroscopy, it showed that the addition of BaO induces an enhancement of both thermal and frequency stability of the dielectric parameters (εr and tanδ). The glass-ceramic with 5 mol% of BaO GC-(x=5) presents the highest dielectric constant and the lowest dielectric loss. The P-E hysteresis loops were recorded at room temperature and the energy storage parameters of the glass-ceramics were determined. These parameters were significantly improved by the increase of the BaO content and the optimum parameters were obtained for GC-(x=5). The dielectric and energy storage parameters were discussed according to the structure data.
Emancipatory societal projects for Latin America: a critical commitment for the reconceptualisation of Social Work at Universidad Católica de Valparaíso School of Social Work
Authors: Martínez Leticia Arancibia , Julio Gloria Cáceres
Published: January 2021

This article analyses the reconceptualisation movement of social work in Chile from mid-1960 to 1973 that impacted on universities, which, in turn, participated in theoretical and political discussions through Latin America during that time. The article has been prepared from the perspective of the project of the School of Social Work at the Catholic University of Valparaíso as an experience that merged the theoretical discussions around radical questioning and professional change. It covers the period from the ‘developmental policies’ in the geopolitical context of the Cold War, when occidental powers competed to extend their influence over Third World countries, to the transition process to socialism during the Popular Unity Government in Chile.
Gender, socio-political cleavages and the co-constitution of gender identities: a multidimensional analysis of self-assessed masculine and feminine characteristics
Authors: Alexander Amy C. , Bolzendahl Catherine , Öhberg Patrik
Published: January 2021

This study offers a multidimensional analysis of individuals’ self-assessments of their masculine and feminine characteristics to better understand variation from more to less binary gender identities. Through gender’s co-constitution along with various social localities, we expect that a number of socio-political factors differentiate individuals’ gender identities through self-assessments of their masculine and feminine characteristics. Using data from a 2013 Swedish survey, our results show that men and women tend towards traditionally polarised gender identities and that social location is a particularly influential correlate of men’s claims of feminine characteristics and women’s of masculine characteristics. Individuals from younger generations and individuals who are more educated are consistently more likely to ascribe to less binary feminine and masculine characteristics. This suggests that generational replacement and higher education may increase the tendency of populations to ascribe to less binary gender identities.
Three-dimensional gravity tailored ultra-broadband absorber based on a high-impedance surface
Authors: Zhang Hao , Tian Xingliang , Zhang Haifeng , Zhang Dan
Published: January 2021

In this paper, we present a novel, to the best of our knowledge, 3D ultra-broadband tunable metamaterial absorber (TMA), which is innovatively tuned by the gravity field with changing the position of the liquid metal (eutectic gallium-indium) in theory. The given TMA consists of a 3D glass cavity filled with the liquid metal, two-layer high-impedance surfaces, two dielectric layers, and a metallic plate on the bottom. The ultra-broadband absorption is achieved by the high-impedance surface and the liquid metal. Furthermore, it is noted that the liquid metal is poured into the different parts of the glass cavities via rotation under the action of the gravity field to obtain the tunable absorption. When such a TMA is not rotated, for the TE wave, the absorption rate exceeds 90% from 1.8 to 57.5 GHz with a wide relative absorption bandwidth (AB) of 187.8%. However, for the TM wave, the absorptivity goes beyond 90% at 5.6–56.4 GHz. The proposed TMA exhibits ultra-broadband absorption in the frequency regime of 1.6–45.3 GHz (the absorption rate is higher than 90%) with such a TMA rotated 180° in the

x

−

y

plane, while the absorption rate is near zero from 1.6 to 60 GHz when the proposed TMA is rotated 180° in the

y

−

z

plane. Moreover, the surface current distributions, the near-field amplitude

|

E
z

|

, the phase

φ
z

, and the magnetic field distributions are investigated to describe the operating mechanism of the designed TMA. Besides, the numerical results indicate that such a TMA can realize high absorption under a wider incident angle. Compared with traditional tunable devices, the gravity field regulation, which can change the operating frequencies of an absorber in a noncontact way, has the advantages of easy implementation and resource savings. The proposed absorber tuned by the gravity will have potential applications in frequency selection. With the change of liquid metal and structure design, this design can also be potentially applied in other microwave and terahertz devices. Taken together, this study suggests a role for such an absorber in promoting a novel application for tunable devices.