bluuebunny/crossref_metadata_2025 huggingface dataset:
Climate‐induced decrease in biomass flow in marine food webs may severely affect predators and ecosystem production
Authors: du Pontavice Hubert , Gascuel Didier , Reygondeau Gabriel , Stock Charles , Cheung William W. L.
Published: March 2021

Climate change impacts on marine life in the world ocean are expected to accelerate over the 21st century, affecting the structure and functioning of food webs. We analyzed a key aspect of this issue, focusing on the impact of changes in biomass flow within marine food webs and the resulting effects on ecosystem biomass and production. We used a modeling framework based on a parsimonious quasi‐physical representation of biomass flow through the food web, to explore the future of marine consumer biomass and production at the global scale over the 21st century. Biomass flow is determined by three climate‐related factors: primary production entering the food web, trophic transfer efficiency describing losses in biomass transfers from one trophic level (TL) to the next, and flow kinetic measuring the speed of biomass transfers within the food web. Using climate projections of three earth system models, we calculated biomass and production at each TL on a 1° latitude ×1° longitude grid of the global ocean under two greenhouse gas emission scenarios. We show that the alterations of the trophic functioning of marine ecosystems, mainly driven by faster and less efficient biomass transfers and decreasing primary production, would lead to a projected decline in total consumer biomass by 18.5% by 2090–2099 relative to 1986–2005 under the “no mitigation policy” scenario. The projected decrease in transfer efficiency is expected to amplify impacts at higher TLs, leading to a 21.3% decrease in abundance of predators and thus to a change in the overall trophic structure of marine ecosystems. Marine animal production is also projected to decline but to a lesser extent than biomass. Our study highlights that the temporal and spatial projected changes in biomass and production would imply direct repercussions on the future of world fisheries and beyond all services provided by Ocean.
Significance of plumage colour for winter survival in the Tawny Owl (Strix aluco): revisiting the camouflage hypothesis
Authors: Solonen Tapio
Published: March 2021

In snowy winters, the survival of Tawny Owls Strix aluco of the grey colour morph is suggested to be better than that of the brown (or red) morph, partly due to their paler plumage, which is presumed to provide better camouflage against predation. If the difference in the susceptibility to predation between the colour morphs is significant, this should probably be reflected in the relation between the number of snow‐covered days (i.e. the length of the winter) and the number and survival of owls of different colour. In a population in southern Finland there were no significant associations between the number of snowy days during winter and the number of breeding Tawny Owls of different colour morphs in the following spring, but the number of owls, in particular red ones, varied inversely with the number of snowy days in the winter of the previous year. The time lag suggests that the number of snow‐covered days (or some related factors) primarily influenced the pre‐breeding survival of young red owls. However, I found no effect of snow days on the proportion of colour morphs, suggesting only small differences in morph‐specific survival under long‐lasting winter conditions.
Retrospective evaluation of intranasal carcinomas in cats treated with external‐beam radiotherapy: 42 cases
Authors: Yoshikawa Hiroto , Gieger Tracy L. , Saba Corey F. , Fredrickson Kirsha , Kubicek Lyndsay , Haney Siobhan , Ruslander David , Kelsey Krista L. , McEntee Margaret C. , Nolan Michael W.
Published: March 2021

Background

Little is known regarding the comparative efficacy of various irradiation strategies used to treat intranasal carcinomas (INC) in cats.

Objectives

Investigate outcomes and prognostic factors associated with survival for cats with INC.

Animals

Forty‐two cats with INC that underwent radiotherapy (RT).

Methods

Single‐arm retrospective study. Medical record review for cats with INC that underwent RT at 1 of 7 veterinary RT facilities. Irradiation protocols categorized as: definitive‐intent fractionated RT (FRT), definitive‐intent stereotactic RT (SRT), and palliative‐intent RT (PRT). Median overall survival time (OST) and disease progression‐free survival (PFS; documented by advanced transverse imaging, or recurrence of symptoms) were calculated. Associations between tumor stage, RT protocol/intent, and adjunctive treatment usage and outcome were calculated.

Results

Cats underwent SRT (N = 18), FRT (N = 8), and PRT (N = 16). In multivariate modeling, cats received definitive‐intent treatment (DRT; FRT/SRT) had significantly longer median PFS (504 days, [95% confidence interval (CI): 428–580 days] vs PRT 198 days [95% CI: 62–334 days];p = 0.006) and median OST [721 days (95% CI: 527–915 days) vs 284 days (95% CI: 0–570 days);p = 0.001]). Cats that underwent second DRT course at time of recurrence lived significantly longer than cats that received 1 RT course (either DRT or PRT [median OST 824 days (95% CI: 237–1410 days) vs 434 days (95% CI: 277–591 days);p= .028]).

Conclusion

In cats with INC, DRT is associated with prolonged OST and PFS as compared to PRT. If tumor progression occurs, a second course of DRT should be considered.
Personality and social memory: High source and destination memory in extroverts
Authors: El Haj Mohamad , Allain Philippe , De Bont Leslie , Ndobo André
Published: March 2021

We evaluated relationship between personality and memory for social interactions. More specifically, we investigated the relationship between extraversion and the ability to remember who told us some information (i.e., source memory) and the ability to remember to whom we told that information (i.e., destination memory). On a source memory task, participants received information from pictures of celebrities; a subsequent recognition test required them to identify the celebrities from whom they had received that information. On a destination memory task, participants were invited to tell information to celebrities; a later recognition task instructed them to identify the celebrity to whom they had previously told that information. Besides the assessment of source and destination memory, participants answered a questionnaire regarding extraversion. Results demonstrated significant positive correlation between extraversion and source memory, as well as significant positive correlation between extraversion and destination memory. In other words, the more participants described themselves as extraverts, the higher their source and destination memory. During social communications (e.g., in a conversation), extraverts may demonstrate high source and destination memory as these individuals typically value social communication, public sharing, and processing of social information.
Towards an Ultimate Finite Element Oriented Solver on Unstructured Meshes
Authors: Belsky Vladimir , Fish Jacob
Published: March 2021

The paper investigates computational efficiency of various finite element solvers, including the state-of-the-art iterative methods based on multigrid-like and Modified Incomplete Cholesky preconditioners, as well as sparse direct solver recently developed at NASA Langley. These methods are compared to the newly developed Finite Element Oriented Solver (FEOS), which combines the advantages of the iterative and direct solution techniques. Numerical tests are conducted for both well-conditioned three dimensional problems as well as poor-conditioned problems, such as thin shells. The proposed FEOS solver has been found to possess a remarkable robustness and computational efficiency, by far superior to its comprising ingredients.
Isothermal Curve Determination in Water to Air Concentric Tube Exchanger Using Finite Difference Method
Authors: Koestoer Raldi Artono , Legi Edwin , Setiadi Nandy
Published: March 2021

This paper discuss the heat tranfer in the concentric tube with numerical solution. Hot water flow in the inner tube and the force circulation of air has been used to absorb the heat from the inner tube in paralel direction. Kosasih and Koestoer [7] compared the result of experimental research and the numerical calculation of temperatur distribution in annular space. In this work, the calculation with Pascal Programming in Personal Computer, continue to inner side where hot water flows and the heat passed the wall in between of both side. Isothermal curve has been established by figuring the temperature points and it was depicted using AutoCad.
Using Computational Fluid Dynamics to Design Heat Transfer Enhancement Methods for Cooling Channels
Authors: Plotnik Aaron M. , Anderson Ann M.
Published: March 2021

This paper presents the results of a study to enhance heat transfer in a short narrow cooling channel (7.9 mm high by 30.9 mm wide by 109 mm long). The study was performed using a computational fluid dynamics (CFD) code. Flotherm, by Flomerics, Inc. The work emphasizes the usefulness of CFD in the design process. The heat transfer enhancement was accomplished by placing thin rib-like protrusions in the channel. Simulations were run for two protrusion spacings, with a range of protrusion heights from 0.5 to 1.5 mm and a range of channel Reynolds number from 500 to 40,000. The results of a grid dependence study are presented and baseline comparisons are made to validate the computational model. The results show increases in channel Nusselt number of 10–160% while the friction factor increases by 10–5200%. The different configurations are compared using a non-dimensional measure of the pumping power and this shows that devices are most effective at low Reynolds numbers. The enhancement in heat transfer, the increase in friction loss and the worth in terms of pumping power would all have to be weighed with respect to the needs of a particular application before any choice is made to apply the techniques studied in this report.
Validation of the INS3D-UP Code in the Prediction of Turbulent Flow of Liquid Propellants in a Sharp Bend
Authors: Sharif M. A. R. , Haskew J. T.
Published: March 2021

The capability of the INS3D-UP code in the prediction of turbulent flow in a sharp bend of circular cross-section has been investigated. The code, developed by the NASA Ames Research Center, is being used by the NASA Marshal Space Flight Center to analyze turbulent flow of liquid propellant in vaned pipe bends designed for use in the Space Shuttle Main Engine. The FORTRAN code is based on finite difference method and uses the concept of pseudocompressibility to solve incompressible Navier-Stokes equation. The Baldwin-Barth turbulence model is embedded in the code for turbulence computation. The flow field, at a Reynolds number of 43,000, in a sharp 90° bend has been predicted and compared with measurement. It is found that the agreement between the predicted and measured velocities is very well. The predicted pressures at the bend wall also compares reasonably well with the measurement. It is concluded that the INS3D-UP code is a good computational tool to analyze similar flow problems.
Computational Fluid Mechanics Studies of Conical Diffuser Flow
Authors: Chin S. B. , Bullough W. A. , Cardew G. E. , Kinsella J.
Published: March 2021

Values of pressure recovery coefficient (PRC) are compared for flow through and along conical diffusers. Overall analytical, experimental and Computational Fluid Mechanics (CFM) determined characterisations are presented for a range of included angle 20, at industrially representative Reynolds numbers, and for the 7° diffuser, over a range of Reynolds numbers. The 7° diffuser is also examined for variation in PRC along its length, at one Reynolds number. All diffusers have the same diameter ratio. The results were verified against data from the internal aerodynamics literature.

These examinations were carried out in order to build up confidence in the use of a proprietary CFM package as a basis for the study of flows in diffusers and, in particular, pressure distributions therein. Computation and experiments were done by undergraduate students acting in concert, on a class mini-project.

Problems of modelling, boundary location and specification of numerical boundary conditions vis a vis real diffuser situations with and without inlet duct and tailpipe are described. The relationship between measured wall tappings of pressure and pressure variations and those from the numerical solution are investigated.
Optimal Design of a Pulsed Water Jet Nozzle
Authors: Li Zheng , Geskin E. S.
Published: March 2021

The objective of this paper is to evaluate the effect of the geometry of downstream edge in the resonating cavity on the performance of a pulsating water jet nozzle. The operation of this nozzle is evaluated by numerical modeling of the water flow within the nozzle. A procedure of computer simulation is employed to examine the performance of the nozzle and the numerical simulation results are validated by the experiments. The nozzle is formed by the use of two conventional nozzles connected by a cavity and numerical and experimental results show that the downstream edge in the cavity has an important effect on the performance of the nozzle. The obtained information demonstrate that the downstream edge with geometry of concave shape is better than the one of convex and flat surface due to its convergent shape enhancing the focusing of the jet and thus increasing the jet kinetic energy. The numerical and experimental results show that the optimal angle of downstream edge is 75° for the best operation of the nozzle. The substantial increase of the rate of cleaning and erosion of such as aluminum, steel and titanium in the course of use of optimal designed nozzle is observed. The obtained computational results enable us to design an effective nozzle suitable for both material removal and surface processing.
Conceptual Design With Functionally and Morphologically Parametrized Feature Objects
Authors: Horváth Imre , Thernesz Vilmos , Bagoly Zoltán
Published: March 2021

Innovative conceptual design is a critical factor to produce competitive industrial and consumer products. Conceptual design needs to be formalized and supported by computational models in order to be covered by computer based design environments. Until now, scheme-based, symbolic and/or physical feature oriented approaches have been applied to generate conceptual models of products. In the case of these approaches, morphological aspects are more or less neglected. Concept features, presented in this paper, are able to represent information on both initial geometries and structural relationships. A concept feature object is a knowledge chunk that defines (a) a set of entities that is needed to build up a skeleton of a part or subassembly, (b) a set of parameters that is needed to characterize a skeleton from a morphological point of view, (c) a set of parameters and physical expressions that describe the possible operation and behaviour of skeletons. Generic modelling is used to derive skeletons. The skeleton and their operational descriptions, as neural Petri nets, form organs that are combined into an organ structure of the modelled industrial or consumer product. The methodology of modelling and simulation with concept feature-objects is described.
Maximal Volume Decomposition and its Application to Feature Recognition
Authors: Dave Parag , Sakurai Hiroshi
Published: March 2021

A method has been developed that decomposes an object having both planar and curved faces into volumes, called maximal volumes, using the halfspaces of the object. A maximal volume has as few concave edges as possible without introducing additional halfspaces. The object is first decomposed into minimal cells by extending the faces of the object. These minimal cells are then composed to form maximal volumes. The combinations of such minimal cells that result in maximal volumes are searched efficiently by examining the relationships among those minimal cells.

With this decomposition method, a delta volume, which is the volume difference between the raw material and the finished part, is decomposed into maximal volumes. By subtracting maximal volumes from each other in different orders and applying graph matching to the resulting volumes, multiple interpretations of features can be generated.
Representation of Manufacturing Environment and Structured Knowledge Base in a CAPP System
Authors: Zhou Xiangyu , Yan Junqi , Jin Yi , Ma Dengzhe , Ling Zhi-Kui
Published: March 2021

Process Planning of a product determines the process activities during its manufacturing process. Transformation of the product from design to its final form by process planning is controlled by its manufacturing environment. In this paper, the systematic representation of a manufacturing environment and a hierarchical data model to represent a process plan is studied and introduced for the flexibility of the Computer Aided Process Planning (CAPP) system and for the integration purpose. An event-driven architecture for the design of general CAPP systems is established based on these models. A CAPP system (U-CAPP) developed by the authors based on these concepts is briefly described.
Complex Dies Representation and Definition With Complex Feature-Based Model
Authors: Mawussi Kwamivi , Bernard Alain
Published: March 2021

The production of stamped-paris corresponds to a long manufacturing process compared to a mechanical part obtained by chip removing machining. This manufacturing process is characterized by three design functions : the design of finished part, the design of stamped-part and the definition of dies, and two manufacturing functions : the dies machining and the production (large batch) of forged parts. The manifold data handled during the implementation of the design functions require specific representations according to the tasks carried out.

In this paper we propose a complex features-based model for the representation and the definition of forging dies which allows to conceptualize all the definition data related to the semantic, structural and topological aspects. According to the semantic and structural point of view, we adopted a functional and hierarchical decomposition of the shape of the die represented which integrates the feature concept. Relations between elements of the model and blend primitives network are defined in order to facilitate the topological comprehension and exploitation of the design results.
Prototyping and Design for Assembly Analysis Using Multimodal Virtual Environments
Authors: Gupta Rakesh , Zeltzer David
Published: March 2021

This work investigates whether estimates of ease of part handling and part insertion can be provided by multimodal simulation using virtual environment (VE) technology, rather than by using conventional table-based methods such as Boothroyd and Dewhurst Charts.

To do this, a unified physically based model has been developed for modeling dynamic interactions among virtual objects and haptic interactions between the human designer and the virtual objects. This model is augmented with auditory events in a multimodal VE system called the “Virtual Environment for Design for Assembly” (VEDA). Currently these models are 2D in order to preserve interactive update rates, but we expect that these results will be generalizable to 3d models.

VEDA has been used to evaluate the feasibility and advantages of using multimodal virtual environments as a design tool for manual assembly. The designer sees a visual representation of the objects and can interactively sense and manipulate virtual objects through haptic interface devices with force feedback. He/She can feel these objects and hear sounds when there are collisions among the objects. Objects can be interactively grasped and assembled with other parts of the assembly to prototype new designs and perform Design for Assembly analysis.

Experiments have been conducted with human subjects to investigate whether Multimodal Virtual Environments are able to replicate experiments linking increases in assembly time with increase in task difficulty. In particular, the effect of clearance, friction, chamfers and distance of travel on handling and insertion time have been compared in real and virtual environments for peg-in-hole assembly task. In addition, the effects of degrading/removing the different modes (visual, auditory and haptic) on different phases of manual assembly have been examined.
Self-Organizing Neural Networks for Automated Machinery Monitoring Systems
Authors: Zhang Siyu , Ganesan R. , Sankar T. S.
Published: March 2021

Two fundamental problems that are frequently encountered in automated machinery monitoring and diagnostics are formulated into their corresponding mathematical problems of clustering and trend analysis. The need for and the efficiency of multiple-index based trend analysis, in both precisely evaluating the current conditions of a machine system using on-line vibration measurements and obtaining a reliable prediction about its future behaviour, are systematically brought out. Neural network solutions to these problems, particularly the solutions using Self-Organizing Maps (SOM) are sought. Statistical parameters of the on-line vibration signal such as peak-to-peak value, absolute mean value, crest factor etc., are used to form the data set depending on the machinery system being monitored and diagnosed. Self-organizing mapping algorithm is then employed to perform the clustering and feature extraction which takes as the input the multi-dimensional data set and provides as the output the condition of the machinery system. Associated one-layer neural network is developed during the process of SOM and the training of this network is performed in an unsupervised learning mode. A new efficient neural network algorithm that has been previously developed by the present authors for multiple-index based regression is adapted to perform the trend analysis of a machine system. Applications of the above neural network algorithms to the condition monitoring and life estimation of both a bearing system as well as a rotor system are fully demonstrated using real-life data.
Characterization and comparison of echolocation clicks of white-beaked dolphins (Lagenorhynchus albirostris) off the Northumberland coast, UK
Authors: Yang Liangliang , Sharpe Matt , Temple Andrew J , Berggren Per
Published: March 2021

Odontocetes produce ultrasonic clicks for navigation and foraging. These are commonly categorized as regular or buzz clicks based on the inter-click interval. Buzz clicks are linked to foraging behaviors and may be subdivided into slow buzz clicks for prey chase, and regular buzz clicks for prey capture. This study recorded these three click types produced by white-beaked dolphins (Lagenorhynchus albirostris) off the Northumberland coast, UK. Acoustic parameters (including duration, centroid frequency, and root-mean-squared bandwidth) were calculated and compared across the three click types. The results showed that the regular clicks had shorter durations and higher frequencies than both the buzz click types. The regular buzz clicks had longer durations, lower frequencies, and narrower bandwidths than the slow buzz clicks. Additionally, regardless of click type, about 30% of the clicks had high-frequency (200–250 kHz) secondary peaks and >90% of the clicks displayed spectral peak and notch patterns between 20 and 80 kHz. These findings are useful for future quantitative assessment of the echolocation performance of white-beaked dolphins in the wild. The patterns of spectral peaks and notches identified may facilitate for acoustic identification of this species.
SARS-CoV-2 mutations in MHC-I-restricted epitopes evade CD8
+
T cell responses
Authors: Agerer Benedikt , Koblischke Maximilian , Gudipati Venugopal , Montaño-Gutierrez Luis Fernando , Smyth Mark , Popa Alexandra , Genger Jakob-Wendelin , Endler Lukas , Florian David M. , Mühlgrabner Vanessa , Graninger Marianne , Aberle Stephan W. , Husa Anna-Maria , Shaw Lisa Ellen , Lercher Alexander , Gattinger Pia , Torralba-Gombau Ricard , Trapin Doris , Penz Thomas , Barreca Daniele , Fae Ingrid , Wenda Sabine , Traugott Marianna , Walder Gernot , Pickl Winfried F. , Thiel Volker , Allerberger Franz , Stockinger Hannes , Puchhammer-Stöckl Elisabeth , Weninger Wolfgang , Fischer Gottfried , Hoepler Wolfgang , Pawelka Erich , Zoufaly Alexander , Valenta Rudolf , Bock Christoph , Paster Wolfgang , Geyeregger René , Farlik Matthias , Halbritter Florian , Huppa Johannes B. , Aberle Judith H. , Bergthaler Andreas
Published: March 2021

SARS-CoV-2 mutations in MHC-I epitopes identified by deep viral sequencing evade CTL responses through decreased peptide-MHC-I binding.
Development and Validation of an
In Silico
Decision Tool To Guide Optimization of Intravenous Artesunate Dosing Regimens for Severe Falciparum Malaria Patients
Authors: Zaloumis Sophie G. , Whyte Jason M. , Tarning Joel , Krishna Sanjeev , McCaw James M. , Cao Pengxing , White Michael T. , Dini Saber , Fowkes Freya J. I. , Maude Richard J. , Kremsner Peter , Dondorp Arjen , Price Ric N. , White Nicholas J. , Simpson Julie A.
Published: March 2021

Most deaths from severe falciparum malaria occur within 24 h of presentation to a hospital. Intravenous (i.v.) artesunate is the first-line treatment for severe falciparum malaria, but its efficacy may be compromised by delayed parasitological responses.
The Reovirus μ2 C-Terminal Loop Inversely Regulates NTPase and Transcription Functions versus Binding to Factory-Forming μNS and Promotes Replication in Tumorigenic Cells
Authors: Yip Wan Kong (Wynton) , Cristi Francisca , Trifonov Georgi , Narayan Nashae , Kubanski Mark , Shmulevitz Maya
Published: March 2021

Reovirus is a model system for understanding virus replication and also a clinically relevant virus for cancer therapy. We identified the first mutation that increases reovirus infection in tumorigenic cells by enhancing postentry stages of reovirus replication.
Subsystems and Fuzzy Relation Equations of Fuzzy Automata Based on Generalized Residuated Lattice
Authors: Singh Anupam K. , Gautam Vinay
Published: March 2021

The objective of this paper is to establish the concepts of subsystems, reverse subsystems and double subsystems of a fuzzy automata based on generalized residuated lattices where the fuzzy sets are equipped with generalized residuated lattice in which the commutative property does not hold and characterizes them in terms of fuzzy relation inequalities and equations. Also, the opening and closure systems in the lattices of fuzzy subsets of [Formula: see text] can be discussed for these six subsystems.
Effects of Plasticizer Content and Ceramic Addition on Electrochemical Properties of Cross-Linked Polymer Electrolyte
Authors: Du Zhijia , Chen X. Chelsea , Sahore Ritu , Wu Xianyang , Li Jianlin , Dudney Nancy J.
Published: March 2021

The development of a safe electrolyte is the key to improving energy density for next generation lithium batteries. In this work, UV-crosslinked poly(ethylene oxide) (PEO) -based polymer and composite electrolytes are systematically investigated on their ionic conductivity, mechanical and electrochemical properties. The polymer electrolytes are plasticized with non-flammable linear short-chain PEO. In the composite electrolytes, a doped lithium aluminum titanium phosphate (LATP) ceramic, LICGC™, is used as the ceramic filler. It is found that the addition of the plasticizer leads to a tradeoff between ion transport and mechanical properties. In contrast, the addition of ceramic fillers improves both the ionic conductivity and mechanical properties. The sample with 20 wt% of LICGC™ shows a conductivity of ∼0.6 mS cm−1 at 50 °C. This sample also demonstrates much longer cycle life than the neat polymer electrolyte in Li platting/stripping test with a capacity of 1 mAh cm−2. A full cell made with this composite electrolyte against Li metal anode and high voltage LiNi0.6Mn0.2Co0.2O2 cathode shows 94% capacity retention after 30 cycles, compared to 58% capacity retention with the neat polymer electrolyte. These results demonstrate that a hybrid of polymer/ceramic/non-flammable plasticizer is a promising path to high energy density, high voltage lithium batteries.
Statistical Analysis of Public Sentiment on the Ghanaian Government: A Machine Learning Approach
Authors: Andoh John , Asiedu Louis , Lotsi Anani , Chapman-Wardy Charlotte
Published: March 2021

Gathering public opinions on the Internet and Internet-based applications like Twitter has become popular in recent times, as it provides decision-makers with uncensored public views on products, government policies, and programs. Through natural language processing and machine learning techniques, unstructured data forms from these sources can be analyzed using traditional statistical learning. The challenge encountered in machine learning method-based sentiment classification still remains the abundant amount of data available, which makes it difficult to train the learning algorithms in feasible time. This eventually degrades the classification accuracy of the algorithms. From this assertion, the effect of training data sizes in classification tasks cannot be overemphasized. This study statistically assessed the performance of Naive Bayes, support vector machine (SVM), and random forest algorithms on sentiment text classification task. The research also investigated the optimal conditions such as varying data sizes, trees, and kernel types under which each of the respective algorithms performed best. The study collected Twitter data from Ghanaian users which contained sentiments about the Ghanaian Government. The data was preprocessed, manually labeled by the researcher, and then trained using the aforementioned algorithms. These algorithms are three of the most popular learning algorithms which have had lots of success in diverse fields. The Naive Bayes classifier was adjudged the best algorithm for the task as it outperformed the other two machine learning algorithms with an accuracy of 99%, F1 score of 86.51%, and Matthews correlation coefficient of 0.9906. The algorithm also performed well with increasing data sizes. The Naive Bayes classifier is recommended as viable for sentiment text classification, especially for text classification systems which work with Big Data.
Cerebral Sinus Thrombosis Secondary to SARS-CoV-2 Infection
Authors: Khazaei Mojtaba , Karimi Kiana , Sedighi Parinaz , Khazaei Salman
Published: March 2021

Coronavirus disease-19 (COVID‐19) is a novel infectious disease and every day we are learning more about its various clinical features and complications. Different studies during the pandemic have shown various neurological manifestations secondary to the infection such as stroke due to cerebral vessel thrombosis. Herein, we presented a 57-year-old man admitted to our hospital with gradual headache, seizure, and decreasing level of consciousness. Three weeks earlier, he was diagnosed with COVID-19 and mild to moderate respiratory problems. Decreased level of consciousness made physicians intubate the patient and initiate mechanical ventilation in the intensive care unit (ICU). Treatment was initiated with phenytoin. Brain CT scan showed right transverse sinus and cortical vein thrombosis with subarachnoid hemorrhage. He received successful anticoagulant therapy, with further improvement in oxygenation, and discharged with a good general condition. This case is important because several neurological complications of COVID-19 should be noticed and managed by appropriate treatment according to the patient’s condition.
Impact of Ethnicity and Underlying Comorbidity on COVID‐19 Inhospital Mortality: An Observational Study in Abu Dhabi, UAE
Authors: Deeb Asma , Khawaja Khulood , Sakrani Nida , AlAkhras Abdulla , Al Mesabi Ahmed , Trehan Ravi , Kumar Palat Chirakkara , Babiker Zahir , Nagelkerke Nico , Fru-Nsutebu Emmanuel
Published: March 2021

Background. The UAE reported its first cluster of COVID 2019 in a group of returned travellers from Wuhan in January 2020. Various comorbidities are associated with worse disease prognosis. Understanding the impact of ethnicity on the disease outcome is an important public health issue but data from our region is lacking. Aim. We aim to identify comorbidities among patients hospitalized for COVID‐19 that are associated with inhospital death. Also, to assess if ethnicity is correlated with increased risk of death. Patients and Method. The study is a single‐centre, observational study in Shaikh Shakhbout Medical City, Abu Dhabi. Patients admitted with COVID‐19, between 1st of March and the end of May, were enrolled. Records were studied for demography, comorbidity, and ethnicity. Ethnicity was divided into Arabs (Gulf, North Africa, and the Levant), South Asia (India, Pakistan, Bangladesh, Nepal, and Afghanistan), Africans, the Philippines, and others. The study was approved by the Department of Health of Abu Dhabi. Results. 1075 patients (972 males) were enrolled. There were 24 nationalities under 5 ethnicity groups. Mean (average) age was 51 years (20–81). 101 (9.4%) died with deceased patients being significantly older. Death risk was not significantly influenced by sex. Duration of hospitalization among survivors was 6.2 days (0.2–40.4) with older patients and men staying longer (P < 0.01). Comorbidities of diabetes, hypertension, cardiovascular disease, chronic renal disease, liver disease, and malignancy were associated with higher risk of mortality univariate, but only liver disease reached statistical significance after adjustment for age. The highest percentage of death was seen in Arab Levant (21.2) followed by the Asian Afghan (18.8); however, differences among ethnicities did not reach statistical significance (P = 0.086). Conclusion. COVID‐19 outcome was worse in older people and those with comorbidities. Men and older patients required longer hospitalization. Ethnicity is not seen to impact the risk of mortality.
An Interpretable Model‐Based Prediction of Severity and Crucial Factors in Patients with COVID‐19
Authors: Zheng Bowen , Cai Yong , Zeng Fengxia , Lin Min , Zheng Jun , Chen Weiguo , Qin Genggeng , Guo Yi
Published: March 2021

This study established an interpretable machine learning model to predict the severity of coronavirus disease 2019 (COVID‐19) and output the most crucial deterioration factors. Clinical information, laboratory tests, and chest computed tomography (CT) scans at admission were collected. Two experienced radiologists reviewed the scans for the patterns, distribution, and CT scores of lung abnormalities. Six machine learning models were established to predict the severity of COVID‐19. After parameter tuning and performance comparison, the optimal model was explained using Shapley Additive explanations to output the crucial factors. This study enrolled and classified 198 patients into mild (n = 162; 46.93 ± 14.49 years old) and severe (n = 36; 60.97 ± 15.91 years old) groups. The severe group had a higher temperature (37.42 ± 0.99°C vs. 36.75 ± 0.66°C), CT score at admission, neutrophil count, and neutrophil‐to‐lymphocyte ratio than the mild group. The XGBoost model ranked first among all models, with an AUC, sensitivity, and specificity of 0.924, 90.91%, and 97.96%, respectively. The early stage of chest CT, total CT score of the percentage of lung involvement, and age were the top three contributors to the prediction of the deterioration of XGBoost. A higher total score on chest CT had a more significant impact on the prediction. In conclusion, the XGBoost model to predict the severity of COVID‐19 achieved excellent performance and output the essential factors in the deterioration process, which may help with early clinical intervention, improve prognosis, and reduce mortality.
A Posteriori Error Analysis for a Lagrange Multiplier Method for a Stokes/Biot Fluid-Poroelastic Structure Interaction Model
Authors: Wilfrid Houédanou Koffi
Published: March 2021

In this work, we develop an a posteriori error analysis of a conforming mixed finite element method for solving the coupled problem arising in the interaction between a free fluid and a fluid in a poroelastic medium on isotropic meshes in

ℝ

d

,

d
∈

2
,
3

. The approach utilizes a Lagrange multiplier method to impose weakly the interface conditions [Ilona Ambartsumyan et al., Numerische Mathematik, 140 (2): 513-553, 2018]. The a posteriori error estimate is based on a suitable evaluation on the residual of the finite element solution. It is proven that the a posteriori error estimate provided in this paper is both reliable and efficient. The proof of reliability makes use of suitable auxiliary problems, diverse continuous inf-sup conditions satisfied by the bilinear forms involved, Helmholtz decomposition, and local approximation properties of the Clément interpolant. On the other hand, inverse inequalities and the localization technique based on simplexe-bubble and face-bubble functions are the main tools for proving the efficiency of the estimator. Up to minor modifications, our analysis can be extended to other finite element subspaces yielding a stable Galerkin scheme.
Lagenandra wayambae (Araceae), a new endemic species from a freshwater swamp forest of Sri Lanka

Authors: MADOLA INDRAKHEELA , YAKANDAWALA KAPILA , YAKANDAWALA DEEPTHI , KARUNARATNE SENANI
Published: March 2021

A new species of Lagenandra (Araceae), is described and illustrated from Walauwewaththa Wathurana freshwater swamp forest, Bulathsinghala, Sri Lanka. Here we describe the new species as Lagenandra wayambae Madola, K. Yakandawala, D. Yakandawala and Karunaratne and provide a detailed description, drawing and colour photographs. We compare the morphology of L. wayambae with that of similar members of Lagenandra and conduct an assessment of its conservation status. A taxonomic key to the Sri Lankan Lagenandra is presented for easy identification. Recognizing a new endemic member enhances the number of Sri Lankan species to nine. According to the IUCN red data category guidelines L. wayambae qualifies for Critically Endangered category under Criterion B1ab (ii,iii,v) + B2ab (ii,iii,v).
von Willebrand disease: what does the future hold?
Authors: Denis Cécile V. , Susen Sophie , Lenting Peter J.
Published: March 2021

von Willebrand disease (VWD) is characterized by its heterogeneous clinical manifestation, which complicates its diagnosis and management. The clinical management of VWD has remained essentially unchanged over the last 30 years or so, using von Willebrand factor (VWF) concentrates, desmopressin, and anti–fibrinolytic agents as main tools to control bleeding. This is in contrast to hemophilia A, for which a continuous innovative path has led to novel treatment modalities. Despite current VWD management being considered effective, quality-of-life studies consistently reveal a higher than anticipated burden of VWD on patients, which is particularly true for women. Apparently, despite our perceived notion of current therapeutic efficiency, there is space for innovation with the goal of reaching superior efficacy. Developing innovative treatments for VWD is complex, especially given the heterogeneity of the disease and the multifunctional nature of VWF. In this perspective article, we describe several potential strategies that could provide the basis for future VWD treatments. These include genetic approaches, such as gene therapy using dual-vector adenoassociated virus and transcriptional silencing of mutant alleles. Furthermore, protein-based approaches to increase factor FVIII levels in VWD-type 3 or 2N patients are discussed. Finally, antibody-based options to interfere with VWF degradation (for congenital VWD-type 2A or acquired von Willebrand syndrome-type 2A) or increase endogenous VWF levels (for VWD-type 1) are presented. By highlighting these potential strategies, we hope to initiate an innovative path, which ultimately would allow us to better serve VWD patients and their specific needs.
The evolution of hemocyanin genes in Tectipleura: a multitude of conserved introns in highly diverse gastropods
Authors: Schäfer Gabriela Giannina , Pedrini-Martha Veronika , Jackson Daniel John , Dallinger Reinhard , Lieb Bernhard
Published: March 2021

Background

Hemocyanin is the oxygen transporter of most molluscs. Since the oxygen affinity of hemocyanin is strongly temperature-dependent, this essential protein needs to be well-adapted to the environment. In Tectipleura, a very diverse group of gastropods with > 27,000 species living in all kinds of habitats, several hemocyanin genes have already been analyzed. Multiple independent duplications of this gene have been identified and may represent potential adaptations to different environments and lifestyles. The aim of this study is to further explore the evolution of these genes by analyzing their exon–intron architectures.

Results

We have reconstructed the gene architectures of ten hemocyanin genes from four Tectipleura species:Aplysia californica, Lymnaea stagnalis, Cornu aspersumandHelix pomatia. Their hemocyanin genes each contain 53 introns, significantly more than in the hemocyanin genes of Cephalopoda (9–11), Vetigastropoda (15) and Caenogastropoda (28–33). The gene structures of Tectipleura hemocyanins are identical in terms of intron number and location, with the exception of one out of two hemocyanin genes ofL. stagnalisthat comprises one additional intron. We found that gene structures that differ between molluscan lineages most probably evolved more recently through independent intron gains.

Conclusions

The strict conservation of the large number of introns in Tectipleura hemocyanin genes over 200 million years suggests the influence of a selective pressure on this gene structure. While we could not identify conserved sequence motifs within these introns, it may be simply the great number of introns that offers increased possibilities of gene regulation relative to hemocyanin genes with less introns and thus may have facilitated habitat shifts and speciation events. This hypothesis is supported by the relatively high number of introns within the hemocyanin genes ofPomacea canaliculatathat has evolved independently of the Tectipleura.Pomacea canaliculatabelongs to the Caenogastropoda, the sister group of Heterobranchia (that encompass Tectipleura) which is also very diverse and comprises species living in different habitats. Our findings provide a hint to some of the molecular mechanisms that may have supported the spectacular radiation of one of Metazoa’s most species rich groups.
Borrelia burgdorferi infection modifies protein content in saliva of Ixodes scapularis nymphs
Authors: Kim Tae Kwon , Tirloni Lucas , Bencosme-Cuevas Emily , Kim Tae Heung , Diedrich Jolene K. , Yates John R. , Mulenga Albert
Published: March 2021

Background

Lyme disease (LD) caused by Borrelia burgdorferi is the most prevalent tick-borne disease. There is evidence that vaccines based on tick proteins that promote tick transmission of B. burgdorferi could prevent LD. As Ixodes scapularis nymph tick bites are responsible for most LD cases, this study sought to identify nymph tick saliva proteins associated with B. burgdorferi transmission using LC-MS/MS. Tick saliva was collected using a non-invasive method of stimulating ticks (uninfected and infected: unfed, and every 12 h during feeding through 72 h, and fully-fed) to salivate into 2% pilocarpine-PBS for protein identification using LC-MS/MS.

Results

We identified a combined 747 tick saliva proteins of uninfected and B. burgdorferi infected ticks that were classified into 25 functional categories: housekeeping-like (48%), unknown function (18%), protease inhibitors (9%), immune-related (6%), proteases (8%), extracellular matrix (7%), and small categories that account for <5% each. Notably, B. burgdorferi infected ticks secreted high number of saliva proteins (n=645) than uninfected ticks (n=376). Counter-intuitively, antimicrobial peptides, which function to block bacterial infection at tick feeding site were suppressed 23-85 folds in B. burgdorferi infected ticks. Similar to glycolysis enzymes being enhanced in mammalian cells exposed to B. burgdorferi : eight of the 10-glycolysis pathway enzymes were secreted at high abundance by B. burgdorferi infected ticks. Of significance, rabbits exposed to B. burgdorferi infected ticks acquired potent immunity that caused 40-60% mortality of B. burgdorferi infected ticks during the second infestation compared to 15-28% for the uninfected. This might be explained by ELISA data that show that high expression levels of immunogenic proteins in B. burgdorferi infected ticks.

Conclusion

Data here suggest that B. burgdorferi infection modified protein content in tick saliva to promote its survival at the tick feeding site. For instance, enzymes; copper/zinc superoxide dismutase that led to production of H2O2 that is toxic to B. burgdorferi were suppressed, while, catalase and thioredoxin that neutralize H2O2, and pyruvate kinase which yields pyruvate that protects Bb from H2O2 killing were enhanced. We conclude data here is an important resource for discovery of effective antigens for a vaccine to prevent LD.
A comparative analysis of heart microRNAs in vertebrates brings novel insights into the evolution of genetic regulatory networks
Authors: Nachtigall Pedro G. , Bovolenta Luiz A. , Patton James G. , Fromm Bastian , Lemke Ney , Pinhal Danillo
Published: March 2021

Background

During vertebrate evolution, the heart has undergone remarkable changes that lead to morphophysiological differences in the fully formed heart of these species, such as chamber septation, heart rate frequency, blood pressure, and cardiac output volume. Despite these differences, the heart developmental process is guided by a core gene set conserved across vertebrates. Nonetheless, the regulatory mechanisms controlling the expression of genes involved in heart development and maintenance are largely uncharted. MicroRNAs (miRNAs) have been described as important regulatory elements in several biological processes, including heart biology. These small RNA molecules are broadly conserved in sequence and genomic context in metazoans. Mutations may occur in miRNAs and/or genes that contribute to the establishment of distinct repertoires of miRNA-target interactions, thereby favoring the differential control of gene expression and, consequently, the origin of novel phenotypes. In fact, several studies showed that miRNAs are integrated into genetic regulatory networks (GRNs) governing specific developmental programs and diseases. However, studies integrating miRNAs in vertebrate heart GRNs under an evolutionary perspective are still scarce.

Results

We comprehensively examined and compared the heart miRNome of 20 species representatives of the five major vertebrate groups. We found 54 miRNA families with conserved expression and a variable number of miRNA families with group-specific expression in fishes, amphibians, reptiles, birds, and mammals. We also detected that conserved miRNAs present higher expression levels and a higher number of targets, whereas the group-specific miRNAs present lower expression levels and few targets.

Conclusions

Both the conserved and group-specific miRNAs can be considered modulators orchestrating the core and peripheral genes of heart GRNs of vertebrates, which can be related to the morphophysiological differences and similarities existing in the heart of distinct vertebrate groups. We propose a hypothesis to explain evolutionary differences in the putative functional roles of miRNAs in the heart GRNs analyzed. Furthermore, we present new insights into the molecular mechanisms that could be helping modulate the diversity of morphophysiology in the heart organ of vertebrate species.