bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficacy of Cold Atmospheric Plasma Treatment on Chemical and Microbial Pollutants in Water
Authors: El‐Kalliny Amer S. , Abd‐Elmaksoud Sherif , El‐Liethy Mohamed A. , Abu Hashish Hassan M. , Abdel‐Wahed Mahmoud S. , Hefny Mohamed M. , Hamza Ibrahim A.
Published: April 2021

Here, we studied the effect of cold atmospheric plasma (CAP) on chemical and microbial pollutants. A model compound for organic water pollutants, crystal violet dye (CV), was used as a chemical probe to monitor a rapid change in the reactive oxygen and nitrogen species (ROS/RNS) in water. We used a point electrode to generate plasma above the treated liquid. Three variables (the gap distance between the point electrode and the water surface, the input voltage, and the water thickness below the point electrode) have been studied to show their effects on CV percent removal as a response. Additionally, the microbicidal effect of CAP against rotavirus (RoV), φX174, E. coli, and S. aureus in water was investigated. A rapid virucidal activity was observed, up to 5 log10 reduction in 1 min for φX174 and 4.3 log10 reduction of RoV in 5 min CAP exposure. Viral removal could be due to the fact that plasma produced active species which have an oxidative effect on viral capsid protein. As expected, bacteria were more sensitive to CAP than viruses, as ∼4log10 removal was observed after 30s exposure. The potent antibacterial effect of CAP could be due to the reaction of free radicals with the outer membrane of bacteria or even the penetration of the bacterial cells. CAP has the potential to control microbial and chemical pollution in water. However, further work should be conducted to determine the efficacy of CAP treatment in complex water matrices.
Metal‐Free Synthesis of Alkyl Phenyl Selenides by Reaction of Activated Alcohols with the O‐(tert‐Butyl) Se‐Phenyl Selenocarbonate/HI System
Authors: Temperini Andrea , Ballarotto Marco , Siciliano Carlo
Published: April 2021

The reaction of activated alcohols with the O‐(tert‐butyl) Se‐phenyl selenocarbonate/hydroiodic acid system to give the corresponding alkyl phenyl selenides is described. The direct conversion of the hydroxyl group into a phenylselenenyl group is also extended to allyl‐ and tertiary alkyl alcohols. This work provides a safe, metal‐free, and operationally simple process for the preparation of alkyl phenyl selenides from benzylic alcohols.
Retracted: Artifactual Palindrome and Mutations Resulting from the Stable Secondary Structure of Templates in Sanger Sequencing
Authors: Liu Zhaocheng , Zheng Minxue , Liu Zhaobang
Published: April 2021

Due to its advantages of high precision and low cost, automated Sanger sequencing technology remains useful for many applications despite the emergence of next‐generation sequencing (NGS) platforms. Few studies revealed the sequence errors in sanger sequencing because the instrumentation and chemistry currently used for Sanger sequencing is highly reliable and reproducible. Unexpectedly, in our study, the sequencing artifacts were identified in sequencing the PCR product of rAAV‐ITR (recombination Adeno‐Associated Virus‐inverted terminal repeat) which formed highly stable T‐shaped hairpin and played critical role in virus production. The artifactual sequences were characterized by the 3’ end palindromic sequence and nucleotide substitutions. We confirmed that the presence of stable hairpin in template results in sequencing artifacts by employing disruptor to eliminate the structure, sequencing the PCR product and the synthezized strands containing stable or weak hairpin respectively for comparation. Furthermore, we proposed that endonuclease activity of Taq polymerase cleaves the templates containing stable structure to generate annealed 3’end which acts as primer to synthesize the artifactual palindrome.
Palladium‐Catalyzed Regioselective Coupling of Amidines and 1,2,3‐Triiodobenzenes: Facile Synthesis of 2,3‐Diiodinated N‐Arylbenzimidamides as Potential MDM2 and MDM4 Inhibitors
Authors: Al‐Zoubi Raed M. , Al‐Jammal Walid K. , Al‐Zoubi Mazhar S. , Ferguson Michael J. , Zarour Ahmad , Yassin Aksam , Al‐Ansari Abdulla
Published: April 2021

A facile and unprecedented synthesis of 2,3‐diiodinated N‐arylbenzimidamide derivatives through highly regioselective Buchwald‐Hartwig coupling of 5‐substituted‐1,2,3‐triiodobenzene and amidine is described. Remarkably, the amination reactions are proceeded exclusively at the terminal positions, the less sterically hindered, and the most regioactive positions. The highest yields were isolated from a combination between electron‐poor 1,2,3‐triiodoarenes and electron‐poor benzimidamides. The optimized conditions were found to be suitable for many functional groups. This report discloses the first method to make 2,3‐diiodinated N‐arylbenzimidamides that is efficient, general in scope, highly regioselective, and truly remarkable precursors for other transformations
Security risks in cyber physical systems—A systematic mapping study
Authors: Zahid Maryam , Inayat Irum , Daneva Maya , Mehmood Zahid
Published: April 2021

The increased need for constant connectivity and complete automation of existing systems fuels the popularity of Cyber Physical Systems (CPS) worldwide. Increasingly more, these systems are subjected to cyber attacks. In recent years, many major cyber‐attack incidents on CPS have been recorded and, in turn, have been raising concerns in their users' minds. Unlike in traditional IT systems, the complex architecture of CPS consisting of embedded systems integrated with the Internet of Things (IoT) requires rather extensive planning, implementation, and monitoring of security requirements. One crucial step to planning, implementing, and monitoring of these requirements in CPS is the integration of the risk management process in the CPS development life cycle. Existing studies do not clearly portray the extent of damage that the unattended security issues in CPS can cause or have caused, in the incidents recorded. An overview of the possible risk management techniques that could be integrated into the development and maintenance of CPS contributing to improving its security level in its actual environment is missing. In this paper, we are set out to highlight the security requirements and issues specific to CPS that are discussed in scientific literature and to identify the state‐of‐the‐art risk management processes adopted to identify, monitor, and control those security issues in CPS. For that, we conducted a systematic mapping study on the data collected from 312 papers published between 2000 and 2020, focused on the security requirements, challenges, and the risk management processes of CPS. Our work aims to form an overview of the security requirements and risks in CPS today and of those published contributions that have been made until now, towards improving the reliability of CPS. The results of this mapping study reveal (i) integrity authentication and confidentiality as the most targeted security attributes in CPS, (ii) model‐based techniques as the most used risk identification and assessment and management techniques in CPS, (iii) cyber‐security as the most common security risk in CPS, (iv) the notion of “mitigation measures” based on the type of system and the underline internationally recognized standard being the most used risk mitigation technique in CPS, (v) smart grids being the most targeted systems by cyber‐attacks and thus being the most explored domain in CPS literature, and (vi) one of the major limitations, according to the selected literature, concerns the use of the fault trees for fault representation, where there is a possibility of runtime system faults not being accounted for. Finally, the mapping study draws implications for practitioners and researchers based on the findings.
Human microservices: A framework for turning humans into service providers
Authors: Laso Sergio , Berrocal Javier , García‐Alonso José , Canal Carlos , Manuel Murillo Juan
Published: April 2021

During the last decade, the mobile application market has grown steadily thanks to the massive use of smartphones and the emergence of cloud computing for offloading computation tasks and improving the quality of experience. With the more recent deployment of Internet of Things (IoT) devices, this cloud‐based architectural design and the corresponding communication flow has been maintained. Nevertheless, the increasing amount of information exchanged, the stringent requirements of many IoT applications, and the need for these applications to adapt their behavior in real time to the user's context set these architectural assumptions a challenge. Paradigms such as mobile, mist, and edge computing have recently been proposed to exploit the computational and storage capabilities of current smartphones and IoT devices in order to onload some tasks onto them, reducing the overhead on both the cloud and the network. Currently, the application of these paradigms requires much attention from skilled developers to create ad hoc systems, as there lack standards and tools facilitating their use. This communication introduces Human Microservices as a framework facilitating the deployment of APIs on companion devices in order to provide personal and updated information that can be consumed by other entities. The framework improves the integration of humans in the IoT loop and facilitates the deployment of computation units in devices closer to end users, enhancing system response time by reducing the stress on cloud and network infrastructure. The proposed framework is based on existing standards in order to improve software quality and shorten the learning curve.
Western Tethys origin, tropical Asia and tropical America disjunction in Berchemia and reinstatement of Phyllogeiton (Rhamneae, Rhamnaceae)
Authors: Huang Xianhan , Deng Tao , Chen Shaotian , Landis Jacob B. , Lin Nan , Yang Yi , Hu Guangwan , Zhou Zhuo , Wang Yuehua , Wang Hengchang , Tojibaev Komiljon Sh. , Sun Hang
Published: April 2021

Despite the well‐known biogeographic pattern in the Northern Hemisphere of disjunct distributions in plants between eastern Asia and North America, many details regarding the evolution of the disjunction between lineages of tropical Asia and tropical America remain poorly understood. Berchemia (Rhamnaceae), comprising ca. 32 species, is distributed predominantly in tropical regions of east to southeast Asia and North America. However, the phylogeny and biogeography of this genus are still not clear. Furthermore, fossils of the genus have been found in Europe, making it an ideal group to understand the biogeographical story of tropical disjunction in the Northern Hemisphere. With two nuclear (ETS, ITS) and three plastid (petA‐psbJ, psbA‐trnH, trnL‐F) DNA regions, we first reconstructed the phylogeny of Berchemia with Bayesian inference and maximum likelihood approaches. Our results indicated that Berchemia, excluding the African species B. discolor and B. zeyheri, which were placed into the reinstated Phyllogeiton, was well‐supported as monophyletic. Divergence times and ancestral areas were inferred using a Bayesian uncorrelated lognormal relaxed molecular clock model and Bayesian binary MCMC method, respectively. The core Berchemia likely originated in the Western Tethys during the middle Eocene, then formed the tropical Asia and tropical America disjunction during the Oligocene and further diversified in Asia from the early Miocene on. The formation and diversification of the core Berchemia likely resulted from a mixture of geologic events, such as the close of the Tethys Ocean, disappearance of the North Atlantic Land Bridges, uplift of the Qinghai‐Tibetan Plateau, and climatic events, such as the establishment and enhancement of Asian monsoons.
2D‐Coordination Polymers Constituted from Indium Halides and Dipyridyl N‐Donor Ligands
Authors: Schäfer Thomas C. , Becker Jonathan , Sedykh Alexander E. , Müller‐Buschbaum Klaus
Published: April 2021

Four indium‐based, 2D coordination polymers (CP) were synthesized utilizing InCl3 and InI3 and the bidentate ligands 4,4’‐bipyridine (bipy), 1,2‐di(4‐pyridyl)ethylene (bpe) and 1,2‐di(4‐pyridyl)ethane (bpa). The isoreticular networks
[In2Cl6(bipy)] (1) and
[In2Cl6(bpe)] (2) are constituted by chloride‐ and ligand‐bridged octahedra with a honeycomb like (6,3)‐net topology (hcb topology). In contrast,
[(In4Cl12)(bpa)3] (3) consists of {In4Cl12N6} units, with each indium atom being coordinated by chloride anions and bpa ligands in an octahedral fashion. Bpa ligands connect indium atoms in two dimensions, forming a semi‐regular uninodal 3‐c net with the point symbol (4,82), as present in the fes topology. In
[(InI3)2(bpa)3] (4), indium is coordinated by three iodide and three bpa ligands in a meridional fashion. In contrast to
[In2Cl6(bipy)] (1) and
[In2Cl6(bpe)] (2), the indium‐centered octahedra are linked by the bidentate linker only, but also a honeycomb‐like, zigzag‐shaped (6,3)‐net with a hcb topology is formed. The CPs were investigated by SCXRD, PXRD, IR‐spectroscopy, and with DTA/TG regarding their thermal properties.
The Life Course Construction of Inequalities in Health and Wealth in Old Age
Authors: Oris Michel , Baeriswyl Marie , Ihle Andreas
Published: April 2021

In this contribution, we will mobilize the interdisciplinary life course paradigm to consider the processes through which individual heterogeneity in health and wealth is constructed all along life, from the cradle to old age. Considering altogether historical, family and individual times, the life course perspective has been developed in sociology, (lifespan) psychology and epidemiology, and has framed many important studies during the last four decades. The theory of cumulative disadvantage is for sure the most popular in social sciences, explaining how little inter-individual differences early in life expand all along life to reach maximal amplitude among the “young old” (before the selection by differential mortality at very old age). In lifespan psychology, the theory of cognitive reserve (educational level being a proxy) and its continuation, the theory of use or disuse (of cognition during adult life) have more or less the same explanatory power, cognition being a decisive precondition for active ageing and quality of life in old age. However, in spite of the success of those theoretical bodies, a prominent figure in the field, Glen Elder, recently observed that there is surprisingly little evidence for cumulative processes and that a wide variety of model specifications remain completely untested. This finding makes even more important a critical review of the literature which summarize several robust evidences, but also discuss contradictory results and suggest promising research tracks. This exercise considers the life course construction of inequalities in the distribution of objective resources older adults have (or not) “to live the life they own value” (to quote A. Sen 2001). But it is also crucial to consider the subjective component that is inherent to the understanding of well-being.
Shoulder: Instability
Authors: Tuite Michael J. , Pfirrmann Christian W. A.
Published: April 2021

Glenohumeral instability is the inability to keep the humeral head centered in the glenoid fossa. Glenohumeral instability can be classified according to etiology and direction of instability. The glenoid labrum, the glenohumeral ligaments, and the bony structures contribute to the stability glenohumeral joint and need to be addressed with imaging. One of the difficulties with accurately diagnosing labral tears on MR imaging is the normal labral variants, which can sometimes appear similar to tears. The location and extent of a Hill-Sachs lesion and glenoid rim defects need to be related to recognize engaging Hill-Sachs lesions or off-track situations. There are several types of labral tears that are not associated with a prior dislocation. SLAP tears are one of the more common tears of the labrum and can sometimes be difficult to distinguish from a normal variant superior sublabral recess. Labral tears in overhead thrower occur in the posterosuperior labrum, adjacent to the posterior rotator cuff tears in these athletes. Tears in the posterosuperior labrum are also associated with spinoglenoid notch paralabral cysts, which can be painful and cause external rotation weakness.
Adult Tumors of Soft Tissue, Bone, and Bone Marrow: What the Clinician Wants to Know
Authors: Garner Hillary W. , Murphey Mark D.
Published: April 2021

The perceived value of the radiologist to the healthcare team hinges on the accuracy of image interpretation and the quality, clarity, and consistency of the associated report. A thorough understanding of what clinicians want to know from imaging of soft tissue, bone, and bone marrow tumors allows the radiologist to better analyze and communicate the relevant findings using a common multidisciplinary language. Inclusion in the report of a detailed patient history relative to the tumor is also important in that it indicates to the clinician and the patient a clear engagement in the patient’s care and an insight into the desired imaging objectives. With these tenets in mind, this review highlights what clinicians want to know from imaging for soft tissue, bone, and bone marrow tumors.
Spine Trauma
Authors: Chang Connie Y. , Pathria Mini N.
Published: April 2021

Spine trauma is a common indication for diagnostic imaging, and there has been a gradual shift to using cross-sectional imaging techniques for screening and evaluating the injured spine, particularly in elderly patients where radiography can be challenging. The classification of spinal injuries has evolved in the past decades to rely on a combination of fracture morphology as defined by diagnostic imaging in conjunction with the clinical presentation to stratify patients to determine optimal management. Radiologists need to be familiar with these classification systems, which rely heavily on imaging findings using CT and MRI, to accurately describe spinal injury.
Sports-Related Injuries of the Pediatric Musculoskeleton
Authors: Ecklund Kirsten
Published: April 2021

Worldwide, more than 50 million children and adolescents participate in organized athletic programs annually. Despite the numerous health and well-being benefits, this widespread involvement also leads to acute and overuse injuries that account for millions of medical visits each year. Musculoskeletal injury in childhood may lead to growth disturbance and lifelong disability. Imaging plays a critical role in the diagnosis and management of these injuries. While radiography is sufficient for most long bone fractures, MRI is often necessary for optimal evaluation of injuries involving the radiolucent growth mechanism and articular structures. The following review will discuss the imaging features associated with many sports-related injuries unique to the pediatric musculoskeleton, specifically the lower extremity.
Non-traumatic Musculoskeletal Diseases in Children
Authors: Nievelstein Rutger A. J.
Published: April 2021

The pediatric musculoskeletal system differs from the adult musculoskeletal system in many ways, including anatomical, physiological, and psychological differences. These differences will result in differences in clinical and radiological presentation. In this chapter the specific knowledge essential for radiologists who deal with musculoskeletal diseases in children will be discussed with a focus on: (a) hip pathologies, (b) infectious and inflammatory diseases, and (c) bone and soft tissue tumors.
Elbow Imaging with an Emphasis on MRI
Authors: Anderson Mark W. , Chung Christine B.
Published: April 2021

The elbow is a complex joint made up of three separate articulations within a common capsule. The proximal ulna articulates with the trochlea and functions as a hinge joint, while the proximal radioulnar joint provides for rotational movement of the forearm. The radiocapitellar joint allows for both hinge and rotational movements. Together, these allow for flexion and extension of the arm and, in conjunction with the distal radioulnar joint at the wrist, pronation and supination as well.
Imaging of the Hip
Authors: Sutter Reto , Blankenbaker Donna G.
Published: April 2021

Imaging evaluation of the hip joint requires expert knowledge about the detailed anatomy and specific injuries. This chapter will include various osseous pathologies that can affect the hip joint such as stress fractures, osteonecrosis, or subchondral insufficiency fractures. Several types of mechanical impingement between the osseous components of the hip joint will be discussed such as femoroacetabular impingement, abnormal antetorsion, and subspine impingement. Detailed evaluation of damage to the labrum, articular cartilage, and other intra-articular structures is described.
Pelvis and Groin
Authors: Boutin Robert D. , Robinson Philip
Published: April 2021

The groin and pelvis represent a large anatomical region with disorders affecting a diverse array of osteoarticular, musculotendinous, gastrointestinal, and genitourinary structures. Although it can be difficult to pinpoint a pain generator clinically, patients often present with non-specific orthopedic complaints at the anterior, lateral, inferior, or posterior aspect of the pelvis. The purpose of this practical review is to highlight the most important anatomy, injury patterns, and diagnostic imaging findings at each of these four sites.
Postoperative Knee and Shoulder
Authors: Kassarjian Ara , Rubin David A.
Published: April 2021

Arthroscopic surgery in the knee most commonly addresses ligament, meniscal, or articular cartilage abnormalities. Similarly, arthroscopic surgery of the shoulder most commonly addresses tendon and labral abnormalities. The expected postoperative MRI findings depend on both the procedure performed and the time since surgery. Identifying complications and failed procedures relies on both clinical and imaging evaluations.
Einfluss von Achsdeformitäten und deren Korrektur auf die Arthroseentstehung und -progression
Authors: Imhoff Florian B. , Fucentese Sandro F. , Harrer Jörg , Tischer Thomas
Published: April 2021

Die Beachtung der Beinachse und die Möglichkeiten zur deren Korrektur stellen beim jungen Patienten mit Arthrose ein Grundpfeiler der Therapie dar. Die Kombination einer Gelenksverletzung und einer Achsdeviation führt unweigerlich, je nach Ausmaß und Komorbiditäten, schon nach wenigen Jahren zur fortschreitenden Gonarthrose. Neben der genauen Deformitätenanalyse zur Osteotomieplanung, gilt es, Normbereiche der entsprechenden Winkel zu kennen und eine Zielgröße zur Achskorrektur festzulegen. Aus dem Repertoire der verschiedenen kniegelenksnahen Osteotomien sind dann die Nebeneffekte in Bezug auf patellofemorales Maltracking, ligamentäres Balancing und die Beinlänge abzuschätzen. Gerade im Hinblick auf mögliche (und wahrscheinliche) Folgeoperationen beim jungen Patienten müssen neue knöcherne Deformitäten oder ligamentäre Insuffizienzen, welche potenziell bei Überkorrektur entstehen, unbedingt vermieden werden.
Artificial neural network for modeling and investigating the effects of forming tool characteristics on the accuracy and formability of thin aluminum alloy blanks when using SPIF
Authors: Najm Sherwan Mohammed , Paniti Imre
Published: April 2021

Incremental Sheet Forming (ISF) has attracted attention due to its flexibility as far as its forming process and complexity in the deformation mode are concerned. Single Point Incremental Forming (SPIF) is one of the major types of ISF, which also constitutes the simplest type of ISF. If sufficient quality and accuracy without defects are desired, for the production of an ISF component, optimal parameters of the ISF process should be selected. In order to do that, an initial prediction of formability and geometric accuracy helps researchers select proper parameters when forming components using SPIF. In this process, selected parameters are tool materials and shapes. As evidenced by earlier studies, multiple forming tests with different process parameters have been conducted to experimentally explore such parameters when using SPIF. With regard to the range of these parameters, in the scope of this study, the influence of tool material, tool shape, tool-end corner radius, and tool surface roughness (Ra/Rz) were investigated experimentally on SPIF components: the studied factors include the formability and geometric accuracy of formed parts. In order to produce a well-established study, an appropriate modeling tool was needed. To this end, with the help of adopting the data collected from 108 components formed with the help of SPIF, Artificial Neural Network (ANN) was used to explore and determine proper materials and the geometry of forming tools: thus, ANN was applied to predict the formability and geometric accuracy as output. Process parameters were used as input data for the created ANN relying on actual values obtained from experimental components. In addition, an analytical equation was generated for each output based on the extracted weight and bias of the best network prediction. Compared to the experimental approach, analytical equations enable the researcher to estimate parameter values within a relatively short time and in a practicable way. Also, an estimate of Relative Importance (RI) of SPIF parameters (generated with the help of the partitioning weight method) concerning the expected output is also presented in the study. One of the key findings is that tool characteristics play an essential role in all predictions and fundamentally impact the final products.
A survey on single server private information retrieval in a coding theory perspective
Authors: Alfarano Gianira N. , Khathuria Karan , Weger Violetta
Published: April 2021

In this paper, we present a new perspective of single server private information retrieval (PIR) schemes by using the notion of linear error-correcting codes. Many of the known single server schemes are based on taking linear combinations between database elements and the query elements. Using the theory of linear codes, we develop a generic framework that formalizes all such PIR schemes. This generic framework provides an appropriate setup to analyze the security of such PIR schemes. In fact, we describe some known PIR schemes with respect to this code-based framework, and present the weaknesses of the broken PIR schemes in a unified point of view.
Cardiovascular risk profiles and 20-year mortality in older people: gender differences in the Pro.V.A. study
Authors: Trevisan Caterina , Capodaglio Giulia , Ferroni Eliana , Fedeli Ugo , Noale Marianna , Baggio Giovannella , Manzato Enzo , Maggi Stefania , Corti Maria Chiara , Sergi Giuseppe
Published: April 2021

The age- and gender-related cardio-metabolic changes may limit the applicability of guidelines for the prevention of cardiovascular diseases (CVD) in older people. We investigated the association of cardiovascular risk profile with 20-year all-cause and CVD-mortality in older adults, focusing on age- and gender-specific differences. This prospective study involved 2895 community-dwelling individuals aged ≥65 years who participated in the Pro.V.A study. The sum of achieved target levels (smoking, diet, physical activity, body weight, blood pressure, lipids, and diabetes) recommended by the European Society of Cardiology 2016 guidelines was assessed in each participant. From this sum, cardiovascular risk profile was categorised as very high (0–2), high (3), medium (4), low (5), and very low (6–7 target levels achieved). All-cause and CV mortality data over 20 years were obtained from health registers. At Cox regression, lower cardiovascular risk profile was associated with reduced 20-year all-cause mortality in both genders, with stronger results for women (HR = 0.42 [95%CI:0.25–0.69] and HR = 0.61 [95%CI:0.42–0.89] for very low vs. very high cardiovascular risk profile in women and men, respectively). This trend was more marked for CVD mortality. Lower cardiovascular risk profile was associated with reduced all-cause and CVD mortality only in men < 75 years, while the associations persisted in the oldest old women. A lower cardiovascular risk profile, as defined by current guidelines, may reduce all-cause and CVD mortality in older people, with stronger and longer benefits in women. These findings suggest that personalised and life-course approaches considering gender and age differences may improve the delivery of preventive actions in older people.
Typical field lines of Beltrami flows and boundary field line behaviour of Beltrami flows on simply connected, compact, smooth manifolds with boundary
Authors: Gerner Wadim
Published: April 2021

We characterise the boundary field line behaviour of Beltrami flows on compact, connected manifolds with vanishing first de Rham cohomology group. Namely we show that except for an at most nowhere dense subset of the boundary, on which the Beltrami field may vanish, all other field lines at the boundary are smoothly embedded 1-manifolds diffeomorphic to$${\mathbb {R}}$$R, which approach the zero set as time goes to$$\pm \, \infty$$±∞. We then drop the assumptions of compactness and vanishing de Rham cohomology and prove that for almost every point on the given manifold, the field line passing through the point is either a non-constant, periodic orbit or a non-periodic orbit which comes arbitrarily close to the starting point as time goes to$$\pm \infty$$±∞. During the course of the proof, we in particular show that the set of points at which a Beltrami field vanishes in the interior of the manifold is countably 1-rectifiable in the sense of Federer and hence in particular has a Hausdorff dimension of at most 1. As a consequence, we conclude that for every eigenfield of the curl operator, corresponding to a non-zero eigenvalue, there always exists exactly one nodal domain.
Vascular endothelial cell specification in health and disease
Authors: Marziano Corina , Genet Gael , Hirschi Karen K.
Published: April 2021

There are two vascular networks in mammals that coordinately function as the main supply and drainage systems of the body. The blood vasculature carries oxygen, nutrients, circulating cells, and soluble factors to and from every tissue. The lymphatic vasculature maintains interstitial fluid homeostasis, transports hematopoietic cells for immune surveillance, and absorbs fat from the gastrointestinal tract. These vascular systems consist of highly organized networks of specialized vessels including arteries, veins, capillaries, and lymphatic vessels that exhibit different structures and cellular composition enabling distinct functions. All vessels are composed of an inner layer of endothelial cells that are in direct contact with the circulating fluid; therefore, they are the first responders to circulating factors. However, endothelial cells are not homogenous; rather, they are a heterogenous population of specialized cells perfectly designed for the physiological demands of the vessel they constitute. This review provides an overview of the current knowledge of the specification of arterial, venous, capillary, and lymphatic endothelial cell identities during vascular development. We also discuss how the dysregulation of these processes can lead to vascular malformations, and therapeutic approaches that have been developed for their treatment.
Disparity between ecological and political timeframes for species conservation targets
Authors: Piipponen-Doyle Stella , Bolam Friederike C. , Mair Louise
Published: April 2021

The Convention on Biological Diversity’s (CBD) Aichi Target 12 aimed to prevent species extinctions and improve the conservation status of known threatened species by 2020 but has not been met. As the post-2020 global biodiversity framework is negotiated, it is essential that we learn lessons from past failures. Here, we investigate whether a reduction in extinction risk could realistically be achieved within the ten-year timeframe of the Aichi Targets. We identified threatened bird and mammal species for which a population increase could lead to down-listing on the IUCN Red List and created population models that assumed exponential population growth to predict how long it would take to reach the population size threshold required for down-listing. We found that in the best-case scenario, 39/42 birds (93%) and 12/15 mammals (80%) could be expected to show the population increase required to achieve down-listing by one Red List category within a ten-year timeframe. In contrast, under the worst-case scenario, 67% birds and 40% mammals were predicted to take > 10 years to reach the population threshold. These results indicate a disparity between the ecological timeframes required for species to show a reduction in extinction risk, and the political timeframes over which such ecological change is expected to be achieved and detected. We suggest that quantitative analyses should be used to set realistic milestone targets in the post-2020 framework, and that global indicators should be supplemented with temporally sensitive measures of conservation progress in order to maintain political and societal motivation for species conservation.
Game-theoretical model for the sustainable use of thermal water resources: the case of Ischia volcanic Island (Italy)
Authors: Kicsiny Richárd , Piscopo Vincenzo , Scarelli Antonino , Varga Zoltán
Published: April 2021

The Island of Ischia, one of the Italian active volcanoes, is a famous tourist resort for spa treatments. Spas are supplied by withdrawals from groundwaters which are characterized by a wide range of chemical compositions, salinity and temperature. In natural conditions, the hydrogeological system is recharged by rainfall and by deep fluids; the discharge is towards the sea and the springs. During the peak of the tourist season, when approximately 240 wells are operating simultaneously, a significant additional recharge of the aquifers derives from seawater and from upwelling increase in deep fluids. Although this does not compromise the availability of groundwater, the pumping often determines variation in composition and temperature of groundwater over time. Conversely, the maintenance of a stable quality of thermal waters represents one of the requirements for their therapeutic use in the spas. The study aims to establish game-theoretical modeling of the optimal sustainable exploitation of the groundwater resources of the island by competing users (spas) falling in the same flow tube of the aquifer. In the game the spas are the players, the strategy of a player consists of a fixed pumping rate and daily time durations of pumping, and the player’s utility or payoff is proportional to the total quantity of withdrawn thermal water in a given time period. A special constrained Pareto optimal strategy choice is obtained, considered as a cooperative solution of the game. Pareto optimality means that there is no other strategy choice that makes one player better off without making some other player worse off.
Data workflow to incorporate thermodynamic energies from Calphad databases into grand-potential-based phase-field models
Authors: Dargahi Noubary Kaveh , Kellner Michael , Hötzer Johannes , Seiz Marco , Seifert Hans J. , Nestler Britta
Published: April 2021

In order to approximate Gibbs energy functions, a semi-automated framework is introduced for binary and ternary material systems, using Calphad databases. To generate Gibbs energy formulations by means of second-order polynomials, the framework includes a precise approach. Furthermore, an optional extensional step enables the modeling of systems in which a direct generation leads to the unsatisfactory results in the representation of the thermodynamics. Furthermore, an optional extensional step enables the modeling of systems, in which a direct generation leads to the unsatisfactory results, when representing the thermodynamics. Within this extension, the commonly generated functions are modified to satisfy the equilibrium conditions in the observed material systems, leading to a better correlation with thermodynamic databases. The generated Gibbs energy formulations are verified by recalculating the equilibrium concentrations of the phases and rebuilding the phase diagrams in the considered concentration and temperature ranges, prior to the simulation studies. For all comparisons, a close match is achieved between the results and the Calphad databases. As practical examples of the method, phase-field simulation studies for the directional solidification of the binary – and the ternary – eutectic systems are performed. Good agreements between the simulation results and the reported theoretical and experimental studies from literature are found, which indicates the applicability of the presented approaches.

Graphical Abstract
The Innate Immune Response Characterizes Posterior Reversible Encephalopathy Syndrome
Authors: Nelke Christopher , Schulte-Mecklenbeck Andreas , Pawlitzki Marc , Rolfes Leoni , Räuber Saskia , Gross Catharina C. , Minnerup Jens , Meuth Sven G. , Wiendl Heinz , Ruck Tobias
Published: April 2021

While posterior reversible encephalopathy syndrome (PRES) is often characterized by an inflammatory cerebrospinal-fluid (CSF) profile, knowledge of immune cell patterns in PRES is lacking. Thus, we retrospectively characterized CSF and peripheral blood (PB) from 15 PRES patients, which we analyzed by multidimensional flow cytometry (FC). Results were compared to 72 controls, as well as to 9 patients with progressive multifocal leukoencephalopathy (PML, as a relevant differential diagnosis) and 15 multiple sclerosis patients (MS, as a classical neuroinflammatory disorder), respectively. Total protein level in CSF from PRES patients was elevated compared to that in controls, but not to MS and PML. In-depth FC analysis revealed no differences for adaptive immune cells (B cells, plasma cells, CD4+, and CD8+ T cells) in PB or CSF of PRES compared to controls. In contrast, we observed alterations of the adaptive immune response in CSF of PML and MS compared to PRES, indicating that the adaptive immune response is not a driver of disease in PRES. Indeed, PRES was characterized by an innate immune response with CD14++/CD16+ (intermediate) monocytes elevated in PB and CSF, while CD14++/CD16− (classical) monocytes were decreased in PB from PRES patients as compared to controls. Levels of CD14++/CD16+ monocytes correlated with the duration of hospital stay as a surrogate marker for disease severity in PRES patients. Our findings argue for a role of innate rather than adaptive immunity in the pathophysiology of PRES. The observed shift in monocyte subsets might provide valuable diagnostic clues for the clinical management of these patients.
Porosity Dynamics through Carbonate-Reaction Kinetics in High-Temperature Aquifer Storage Applications
Authors: Tilley B. S. , Ueckert M. , Baumann T.
Published: April 2021

While near-surface geothermal energy applications for the heating and cooling of buildings have been in use for decades, their practical adoption is limited by the energy transport rates through soils. Aquifers provide a means to use convective heat transport to improve heat transfer between the building and the aquifer. However, the solid matrix in the aquifer is carbonaceous in nature, and calcification prevention techniques in the heat exchangers for the building also lead to dissolution of the aquifer matrix. Due to the Arrhenius nature of the reaction, dissolution rates may decrease with increasing temperature. An effective medium model is derived for the energy, calcium species, and fluid transport through a dynamic calcite porous medium which undergoes a reaction between the matrix and fluid. To better discern how these competing phenomena affect thermal transport in the aquifer, a two-dimensional Cartesian system is considered, where the vertical axis is parallel to the borehole axis, and flow is in the horizontal direction. An effective medium model is derived for the energy, calcium species, and fluid transport through a dynamic calcite porous medium which undergoes a reaction between the matrix and fluid. Since the fluid velocity decays algebraically with radial distance from the borehole axis, two flow regimes are considered. In one regime, far from the borehole where flow rates are small, conductive thermal transport acts faster than the species transport, leading to a case where precipitation dominates and regions of the smallest porosity contract to limit energy recovery. In regions with larger porosity, moderate advection of the species is sufficient to prevent significant pore closures over the time scale of exploration. The second regime, closer to the borehole, larger flow rates reduce species concentrations sufficiently to dissolve the solid phase between pores. In this second regime, Taylor dispersion effects in both energy and species transport compete, but thermal conduction acts more slowly than advection, promoting dissolution. The critical limitation in modeling the long-term evolution of the aquifer structure is the in situ dissolution rate.
A image encryption algorithm based on chaotic Lorenz system and novel primitive polynomial S-boxes
Authors: Al-Maadeed Temadher Alassiry , Hussain Iqtadar , Anees Amir , Mustafa Muhammad Tahir
Published: April 2021

We have proposed a robust, secure and efficient image encryption algorithm based on chaotic maps and algebraic structure. Nowadays, the chaotic cryptosystems gained more attention due to their efficiency, the assurance of robustness and high sensitivity corresponding to initial conditions. In literature, there are many encryption algorithms that can simply guarantees security while the schemes based on chaotic systems only promises the uncertainty, both of them can not encounter the needs of current scenario. To tackle this issue, this article proposed an image encryption algorithm based on Lorenz chaotic system and primitive irreducible polynomial substitution box. First, we have proposed 16 different S-boxes based on projective general linear group and 16 primitive irreducible polynomials of Galois field of order 256, and then utilized these S-boxes with combination of chaotic map in image encryption scheme. Three chaotic sequences can be produced by the disturbed of Lorenz chaotic system corresponding to variables x, y and z. We have constructed a new pseudo random chaotic sequence ki based on x, y and z. The plain image is encrypted by the use of chaotic sequence ki and XOR operation to get a ciphered image. To show the strength of presented image encryption, some renowned analyses are performed.
A psychometric evaluation of the Functional assessment of cancer therapy—kidney symptom index (FKSI-19) among renal cell carcinoma patients suggesting an alternative two-factor structure
Authors: Rosenblad Andreas Karlsson , Sundqvist Pernilla , Westman Bodil , Ljungberg Börje
Published: April 2021

Purpose

To psychometrically evaluate the hypothesized four-factor structure of the 19-item Functional Assessment of Cancer Therapy—Kidney Symptom Index (FKSI-19) health-related quality of life (HRQoL) instrument in a sample of surgically treated renal cell carcinoma (RCC) patients and examine if an alternative factor structure with good psychometric properties may be derived from the available items.

Methods

The model fit of the hypothesized four-factor structure was examined using confirmatory factor analysis on cohort data from 1731 individuals included in the National Swedish Kidney Cancer Register who had undergone surgery for RCC during the three years 2016–2018 and answered the FKSI-19 instrument within 6–12 months after surgery. Exploratory factor analysis was applied to the same dataset to derive a possible alternative factor solution.

Results

The four-factor structure did not reach the thresholds for good model fit using the normed χ2-value or the Comparative Fit Index, although the Standardized Root Mean Square Residual and Root Mean Square Error of Approximation measures indicated good and acceptable model fits, respectively. An alternative 14-item trimmed FKSI version (FKSI-14) with a two-factor structure derived from the available FKSI-19 items was found to measure the same aspects of HRQoL as the full FKSI-19 instrument.

Conclusion

The present study is the first to use psychometric methods for examining the factor structure of the FKSI-19 instrument. The hypothesized four-factor structure of FKSI-19 provided a barely acceptable model fit. The two-factor FKSI-14 structure may be used as an alternative or complement to the four-factor structure when interpreting the FKSI-19 instrument.
Efficiency comparison of B6(Cg)-Tyrc−2j /J and C57BL/6NTac embryos as hosts for the generation of knockout mice
Authors: Ma Yu’e , He Lei , Xiang Lijie , Zhang Jie , Wang Jing , Zhu Wenjing , Cao Wenni , Zhu Yichen , Gao Man , Zhou Fei , Liu Zhiwei
Published: April 2021

Careful selection of the host embryo is critical to the efficient production of knockout (KO) mice when injecting mouse embryonic stem (mES) cells into blastocysts. B6(Cg)-Tyrc−2j/J (B6 albino) and C57BL/6NTac (B6NTac) strains of mice are widely used to produce host blastocysts for such procedures. Here, we tested these two strains to identify an appropriate match for modified agouti C57BL/6N (JM8A3.N1) mES cells. When comparing blastocyst yield, super-ovulated B6NTac mice produced more injectable blastocysts per female than B6 albino mice (8.2 vs. 5.4). There was no significant difference in birth rate when injected embryos were transferred to the same pseudopregnant recipient strain. However, the live birth rate was significantly higher for B6NTac blastocysts than B6 albino blastocysts (62.7% vs. 50.2%). In addition, the proportion of pups exhibiting high-level and complete chimerism, as identified by coat color, was also significantly higher in the B6NTac strain. There was no obvious difference in the efficiency of germline transmission (GLT) when compared between B6NTac and B6 albino host embryos (61.5% vs. 63.3% for mES clones; 64.5% vs. 67.9% for genes, respectively), thus suggesting that an equivalent GLT rate could be obtained with only a few blastocyst injections for B6NTac embryos. In conclusion, our data indicate that B6NTac blastocysts are a better choice for the microinjection of JM8A3.N1 mES cells than B6 albino blastocysts.
Plant age affects intraspecific variation in functional traits
Authors: Henn Jonathan J. , Damschen Ellen I.
Published: April 2021

Functional traits are often used to examine ecological patterns and processes. Ontogeny—changes that occur over time as the result of development—generates variation in traits within individual organisms. We aimed to quantify the role of ontogeny in structuring functional trait variation across a range of co-existing herbaceous perennial species and hypothesized that ontogenetic variation in traits would be greater in younger vs. older plants. We grew eight herbaceous perennial forb species common in tallgrass prairies from seed in a greenhouse in Madison, Wisconsin, USA to determine how and when time-related variation in functional traits is large relative to other sources of variation, such as differences between leaves and species. We destructively measured common functional traits on four individuals of each species every two weeks for 19 weeks, including leaf mass fraction, root mass fraction, stem mass fraction, specific leaf area, leaf dry matter content, and leaf area. We found that most functional traits indeed change through time, that the direction of many changes are consistent between species but the magnitude of change is species specific, and most time-related variation occurred earlier in development. These results emphasize the importance of considering sampling timing and differences between young and old plants when measuring functional traits. Our results suggest that ontogenetic intraspecific variation can be substantial, especially early in life. It may be problematic to use traits measured from mature plants to interpret the importance of processes that occur at earlier life stages or vice versa; using seedling traits to understand adult plant responses may also be inappropriate.