bluuebunny/crossref_metadata_2025 huggingface dataset:
Stability of Open‐Top Cylindrical Steel Tanks with Primary Stiffening Ring under Wind Loading
Authors: Zeybek Özer , Topkaya Cem , Rotter J. Michael
Published: September 2021

Cylindrical steel tanks are very thin shell structures and vulnerable to buckling under external pressure due to wind or partial vacuum due to rapid emptying or blocked vents when they are either empty or partially emptied. A primary stiffening ring is commonly used at or near the top of the tank wall to increase its strength against external pressure instability. Most traditional design treatments largely ignore the non‐uniform circumferential variation of the wind and treat the tank as subject only to uniform external pressure when sizing the primary stiffening ring. Moreover, the interior of the tank also experiences suction pressures due to the leeward suction on the tank. Wind tunnel tests have shown that the magnitude of these suctions can be very significant compared with the external wind pressures. This study has investigated the buckling resistance of a range of cylindrical steel storage tanks with primary stiffening rings subjected to non‐uniform wind loading modeled as harmonic variations, including the suction, using finite element analyses. A criterion for the required primary stiffening ring stiffness is developed, which is found to depend on its value relative to the stiffness of the cylindrical shell under each harmonic of wind loading. The effects of the shell‐ring stiffness ratio on the buckling capacity are studied and it is found to be a powerful measure that is critical to the design of the ring. Improved design rules are directly obtainable from this new treatment.
Imperfection sensitivity of unstiffened cylindrical shells under external pressure
Authors: Azizi Esmaeil , Stranghöner Natalie
Published: September 2021

The design rules for cylindrical shells subjected to uniform external pressure can be found in corresponding codes and recommendations, e.g. in EN 1993‐1‐6 (2007) or European Recommendation ECCS EDR5 (2008). Although the buckling strength of thin‐walled shells is highly dependent on the imperfections caused by various fabrication or manufacturing processes, the sensitivity of the buckling resistance of an imperfect shell to the amplitude of the geometric imperfections is not taken into account in design rules of standards.

This paper investigates in detail the effect of boundary conditions and cylinder length on the linear buckling behaviour of cylindrical shells subjected to uniform external pressure. Following this, a comprehensive computational study is performed using geometrically nonlinear analyses on imperfect cylindrical shells with two‐imperfection types: (i) eigenmode‐affine form and (ii) longitudinal eigenmode‐affine pattern. Based on the numerical results obtained from eigenvalue analyses, the existing formulae of EN 1993‐1‐6 for the external pressure buckling factor Cβs of short cylindrical shells are modified to provide a more accurate prediction of the elastic critical circumferential buckling stress. The effects of geometric nonlinearity and imperfection sensitivity on the buckling strength are also briefly explored.
New development of design rules for girder with non‐rectangular slender web
Authors: Pourostad Vahid , Kuhlmann Ulrike
Published: September 2021

The current research work focuses on the analysis of longitudinally stiffened I‐girders with slender non‐rectangular web subjected to bending (M), shear (V) and M‐V interaction. Slender structures of thin panels are usually designed according to the rules in EN 1993‐1‐5 generally assuming rectangular panels. For tapered panels, the verifications in EN 1993‐1‐5, are not clearly stated.

To investigate the behaviour of the non‐rectangular panels, six large tests have been realised at the laboratory at the University of Stuttgart, composed of unstiffened and longitudinally stiffened girders. The unstiffened and stiffened panels are numerically recalculated, and the model is validated. Based on a validated numerical model, a parametric study on stiffened girders has been performed. The chosen parameters cover the common application range of bridges. The results of the numerical parametric study also proved that the influence of inclined flange in respect of shear resistance may be considered advantageously. Therefore, a new resistance models has been developed, the results of the existing and the new resistance models were evaluated and compared with the numerical results from the parametric study.

This paper presents an improved design approach of non‐rectangular panel considering the influence of inclined flange. The proposed approach ensures safe and more economic results for non‐rectangular panels.
Modelling issues and pushover response of singlestory older steel buildings
Authors: Cantisani Gaetano , Della Corte Gaetano
Published: September 2021

The paper describes a study concerning the seismic response of some typical non‐residential single‐story older steel buildings. To this end, the design of two archetype buildings was simulated according to structural codes and standards of practice used in Italy in the 1980s‐1990s. The basic structural layout was assumed to be made of trussed portals in the transverse direction and concentric braces in the longitudinal direction. In the direction of the trussed portals, two alternative structural options were considered: (a) a pinned column base with moment action provided by the truss, and (b) a semi‐continuous column base with a pinned connection between the truss and the column top cross section. 3D finite element non‐linear models of the two case study structures were built. The model included the main frame members, some critical connections and explicit representation of fracture propagation for braces. Results from non‐linear static analysis are then presented and discussed. The paper highlights differences in the structural response due to differences in the selected design options, comparing both global and local response results.
Seismic torsional effects on multi‐storey steel buildings
Authors: Ştefănescu Bogdan Cătălin , Calotescu Ileana
Published: September 2021

During earthquakes, a structure may undergo torsional effects even if it is perfectly symmetrical. One of the causes is that seismic waves do not arrive in‐phase in each point of the infrastructure. Moreover, there are always eccentricities between the mass centre, where the seismic forces are considered to be acting, and the stiffness centre, around which the building rotates, this contributing as well to the occurrence of torsional effects. These eccentricities are generated by asymmetries of the structure itself, position of non‐structural elements, asymmetrically applied loading or other factors. Seismic design codes usually take into account torsional effects by means of an equivalent eccentricity that is added to the actual distance between the centres of mass and stiffness. In ordinary design, to analyse the behaviour of a structure subjected to seismic actions, when establishing the mass of the building, a fraction of the variable loads is considered to be uniformly distributed on each floor. This obviously does not happen in reality. The present paper focuses on estimating the limits of the possible actual variation of internal forces in structural members caused by torsional effects. To this aim, two eccentrically braced steel structures were considered. In each case, the variable loads were redistributed in the plan of the building according to different loading schemes, but keeping their total amount constant, equal to the value corresponding to the uniform arrangement on each floor.
Cyclic behaviour of steel beam‐to‐column joints and calculation tools
Authors: Oliveira Sara , Costa Ricardo , Rebelo Carlos , da Silva Luís Simões
Published: September 2021

The seismic design of dissipative beam‐to‐column steel joints is currently allowed in Eurocode EN1998 only when supported by tests due to the lack of reliable models for predicting their behaviour under cyclic conditions. On the other hand, the well‐known component method coded in EN 1993‐1‐8 (EC3‐1‐8) only applies to monotonic response of the joints. In this paper, an extension of this method, cyclic component method (CCM), is presented, which was developed and implemented for cyclic conditions in the scope of the research project EQUALJOINTS. The CCM was developed to predict the joints moment‐rotation behaviour for a wide range of joint configurations by properly combining cyclic force‐elongation behaviour of relevant components using the Modified Richard‐Abbott model. The step‐by‐step development and implementation of the CCM addresses (i) widespan variety of joint configurations and (ii) is fully compatible with the prescriptions in EC3‐1‐8. An example of application of the method is shown for an end‐plate beam‐to‐column steel beam‐to‐column joint, highlighting the level of accuracy achieved so far in the simulations of the cyclic behaviour of joints. The work performed so far shows promising results and good perspectives for new developments, which are identified making use of evidence from the results of the application example.
Seismic Performance of Steel Bridge Piers Corroded at Corners and Bottoms for Several Earthquake Motions
Authors: Kitahara Takeshi , Ohtani Yuka , Nagata Kazutoshi
Published: September 2021

Corrosion damage on steel bridge piers has been observed at the corners where the coating tends to be thin and at the bottoms where stagnant rainwater tends to be generated. The further progress of such corrosion damage results in degradation of the seismic performance of the piers. Nevertheless, there have been very few studies on the seismic performance of steel bridge piers considering the effect of corrosion damage. In this study, the seismic response analyses by the nonlinear finite element models are carried out to investigate the seismic response behavior of the steel bridge piers with corrosion damage at the corners and bottoms. The objective of this study is to understand the influence of the corrosion damage location, corrosion damage ratio, and uncertainty in the input ground motions on the load‐carrying capacity of steel bridge piers. As a result, it is found that the maximum displacements increase and the maximum loadings decrease as corrosion damage progresses. Moreover, the change rates in the maximum displacements and maximum loadings are affected by changes in the natural periods of the target piers due to corrosion damage and by the frequency properties of the input ground motions.
Optimised Strategies for Seismic‐Resilient Self‐Centring Steel Moment Resisting Frames
Authors: Pieroni Ludovica , Elettore Elena , Freddi Fabio , Latour Massimo
Published: September 2021

In recent years there have been significant advancements in the definition of innovative minimal damage structures chasing the urgent requirements of more resilient societies against extreme seismic events. In this context, a type of seismic‐resilient moment resisting frames (MRFs) is based on the use of Self‐Centring Damage‐Free (SCDF) devices in column bases and beam‐to‐column joints. However, when these devices are widespread across the whole structure, the details' complexity increases significantly with respect to conventional solutions, thus limiting their practical application. To overcome this drawback, current research works are focusing on the definition of optimum locations for SCDF devices such that their effectiveness is maximised. Within this context, the present study investigates optimum locations for a limited number of SCDF devices to be used within mid‐ and high‐rise MRFs. An 8‐storey structure is selected for case study purposes and nineteen configurations are investigated considering different positions of SCDF joints. Numerical models of the selected configurations are developed in OpenSees and Incremental Dynamic Analysis are performed. The seismic responses of the case‐study structures equipped with different layouts of SCDF devices are evaluated and compared. Some considerations in terms of optimal distributions of SCDF devices are made with the aim of maximising the efficiency of the solution and the seismic performance of mid‐ and high‐rise MRFs.
Reliability assessment for the Generalized Slenderness based Resistance Method for circular and elliptical hollow sections
Authors: Beyer André , Gardner Leroy , Meng Xin , Taras Andreas
Published: September 2021

In the framework of the RFCS project HOLLOSSTAB, a new design method for determining the resistance of hollow section members has been developed. This method links a generalized slenderness, calculated under the effect of the combined loading, to the resistance of the cross‐section and of the member. This so‐called “Generalized Slenderness‐based Resistance Method” (GSRM) has been shown to provide accurate predictions of experimentally and numerically determined resistances of hollow sections. Nonetheless, the real benefit of this new design method could only be evaluated after a conscientiously performed reliability analysis that is presented in this paper. First, the statistical data of the input variables (cross‐section dimensions, material law) obtained through measurements are presented and compared to the assumptions of Annex E of EN 1993‐1‐1:2020. Then, the reliability analysis is outlined. In particular, attention is given to specific problems resulting from the fact that several basic parameters of GSRM have to be determined numerically (for example the critical loads under combined loading). In addition, the sensitivity of the resulting partial factors to assumptions concerning the statistical distribution of the input variables is studied and discussed.
Parametric study of stainless steel slender I‐section beams
Authors: Šorf Marek , Jandera Michal
Published: September 2021

The contribution shows a numerical parametric study and experimental research of welded slender stainless steel I‐section beams. Difference in behavior of stainless steel and common carbon steel members is generally known, but design of stainless steel members has been established mainly for hollow sections (CHS, SHS/RHS) as these are the typical stainless steel profiles. Currently, open stainless steel sections are also being used in structures and the design rules for both local buckling of very slender sections as well as lateral torsional buckling reduction factors are based on very limited experimental and numerical research. For this reason new research covering these phenomena was carried out at the Czech Technical University in Prague. A numerical model was used for design of test arrangement, the geometrically and materially nonlinear analysis with imperfection was made in software Abaqus. The experimental program consisted of six stainless steel beam tests being used for a model validation. The tests employed two stainless steel materials (austenitic and ferritic steel), one section slenderness (Class 4 for web and flange) and three beam slenderness. A parametric study based on the validated numerical model was carried out with the main focus on lateral‐torsional buckling of slender Class 3 and Class 4 welded I‐sections. A comparison to the existing design procedures is shown. In limited amount, resistance of Class 4 stainless steel sections in bending was also investigated.
Imperfections of LTB tests with directionally true loading using the extended Southwell‐method
Authors: Nonn Jonas , Feldmann Markus
Published: September 2021

Lateral torsional buckling tests were carried out on rolled I‐beams investigating the real effective imperfections. To this end a special test rig was developed allowing for an utmost restraint‐free, thus precise testing of statically determined beams. As a special feature the load control was such that it had to follow the occurring lateral displacement of the test objects with the use of a high‐resolution electronic control in a directionally true and force‐free manner. The imperfections were evaluated in different ways. First, by recording the geometric imperfections. Secondly, by evaluating the tests according to the Southwell‐method, which was extended for lateral torsional buckling and allows the determination of realistically uncoupled initial imperfections v0 and φ0. With the use of the imperfections, which are derived with the extended Southwell‐method (ESM), FE‐analyses lead to exact prediction of the recorded load deformation, which is shown in the paper for the example of HEA 160 sections.
Stabilizing forces in trapezoidal sheeting used as a part of the bracing system
Authors: Korcz‐Konkol Natalia , Iwicki Piotr
Published: September 2021

In the analysis of bracing systems imperfections of the restrained elements should be considered. According to EC3 this effect can be calculated by means of the equivalent stabilizing force, which replaces (in simplified way) initial bow imperfection of the braced element. However, alternative suggestions of the equivalent stabilizing force calculations can be also found in the literature. In this paper segment of the pitched roof with truss girders, purlins and trapezoidal sheeting was analyzed in two variants: with bar bracing and with trapezoidal cladding as a part of the bracing system (resisting in‐plane forces). The influence of the imperfections of the truss girder on the axial forces in the purlins in two cases of the bracing systems were observed. Geometrically nonlinear analysis using shell elements was performed in Abaqus. Initial imperfections of the truss girder were implemented in direct way (by importing imperfect geometry using LBA) and compare to the analytical result according to three selected methods. A few aspects that are omitted in analytical procedures were included in numerical analysis, e.g. the eccentricity between structural elements and the stiffness of selected connections. Results showed discrepancies between numerical and analytical outcomes.
Recent developments of stainless steels in structural applications
Authors: Backhouse Andrew , Baddoo Nancy
Published: September 2021

The paper reviews the recent trends in the use of stainless steels for practical structural applications. It provides a context for the underpinning engineering research work taking place globally in many universities and research institutes on structural stainless steels, which has enabled the development of economic and comprehensive design standards. An already extensive body of work on the structural use of stainless steel has facilitated the growing use of stainless steels for large structures, usually in corrosive environments where durability, combined with long service life, are important and maintenance closures are very costly.

Work has concentrated on duplex grades of stainless steel. Their high strength (30% higher than carbon steel S355) leads to specific applications in weight sensitive structures and this has resulted in a growing range of duplex grades from materials producers. The rationale for use of stainless steel often considers the wider project requirements, including design life and life cycle costing, future maintenance requirements, sustainability and aesthetical demands. The structural use of stainless steel in several case studies of bridges and other large structures from across the world will be discussed. The opportunities for further academic research activities from the perspective of the stainless steel industry will be highlighted.
Challenges in the Design and Implementation of a Steel Beam Launcher for Precast Girders Assembly
Authors: Rodríguez Patricia García , Cruz Jesús Tomás Muñoz , García Manuel Biedma , Llanos Fernando Flórez , Cañueto Mariano Martín
Published: September 2021

ACCIONA has designed and built a Steel Beam Launcher for Precast Beam Assembly. The structure consists of two steel trusses of triangular tridimensional structure 110.90 m long and 3.755 m high. The hoist load capacity of the Beam Launcher is 110 tons and the maximum span between supports is 52 m. The main challenge for the design of the Beam Launcher has been to guarantee the safety of the works in all the maneuvers to be carried out, taking into account the determining longitudinal slope of the viaducts up to 6.0%. To take on this challenge, the Beam Launcher has been designed with a rack‐and‐pinion system, which ensures total safety in the maneuvers. The Beam Launcher has also been designed to develop all the operations required for the assembly of the Viaducts, such as lateral load of the precast beams from barges, front and rear feed of the Beam Launcher from the adjacent span and front and rear feed from a truck located on the previously poured deck. Besides, the Beam Launcher is modular to adapt to the different spans of the Viaducts, extending and decreasing its length when needed. This modular requirement governs the design of the joints in the Beam Launcher: the connections between diagonals and main chords are pinned and the connections between modules are prestressed, using both prestressed bolts and prestressed bars depending on the demanding forces.
Diffusible Hydrogen Concentration in Drawn Arc Stud Weldments
Authors: Brätz Oliver , Henkel Knuth‐Michael
Published: September 2021

The mechanized drawn arc stud welding is a well established process in steel construction for joining technique for pin shaped elements, especially in the field of composite constructions. Therefore, the process is commonly applied on construction sites under different climatic conditions. The process is characterized by its relatively high heat input due to high current and a weld pool protection that is realized by a ceramic ferrule holding the metal vapor as a shielding gas. However, turbulences inside the ferrule during welding cause contaminations with atmospheric humidity. Furthermore, a high cooling rate results in a strongly hardened heat‐affected zone and a considerable residual stress state in the parent material. Thus, there is a risk of hydrogen assisted cold cracking, especially for stud welding on high strength steels or under adverse welding conditions. The knowledge about the expectable hydrogen concentration is fundamental for evaluating the cold cracking susceptibility. In this study, the effect storage conditions of the consumables and atmospheric conditions are investigated and evaluated regarding their effect on the resulting hydrogen concentration in weld metal. For determination of diffusible hydrogen concentration in stud weld metal a method based on the carrier gas hot extraction is used.
Distortional buckling of compressed cold‐formed lipped C channels via buckling mode shapes
Authors: Vaszilievits‐Sömjén Bálint
Published: September 2021

Distortional buckling is a characteristic failure mode of compressed C channels with an intermediate unbraced length in the range of 4 to 7 times the web depth. The usual codified design method to calculate the buckling resistance by Eurocode EN 1993‐1‐3 proceeds through the determination of an effective cross‐section with reduced thicknesses of the stiffener zones working against distortional buckling. To calculate the slenderness of the compressed stiffener zones Eurocode gives simple formulas, applicable separately for end stiffeners and intermediate stiffeners. The identification of the part of the cross‐section to be used in these formulas can be doubtful. It can be demonstrated that these formulas will predict unreliable critical stresses being often on the unsafe side. EN 1993‐1‐3 allows to use more reliable values based on FEA or other approaches without giving a detailed, applicable design methodology.

This paper presents a method which is able to assign cross‐section buckling modes calculated with the help of finite strip analysis to compressed stiffener zones of a compressed general C section. Assignment is based on the determination of deformation energy balance. The proposed approach finds the zones of the section which tend to buckle during distortional buckling and the zones which are responsible to restrain this buckling. Additionally, it gives guidance on how to determine the exact area where the calculated thickness reduction shall be applied around the stiffener. For the thickness reduction the buckling curve given in the actual EN 1993‐1‐3 will be used.

The proposed method is part of a larger research project which aims to provide a complete Eurocode compatible design methodology considering local, distortional and global buckling of general shaped cold‐formed members subject to 3D loading and support condition, to be implemented in computer software programs working with 7DOF beam finite elements..
Triaminocyclopentadienyl Ruthenium Complexes – New Catalysts for Cascade Conversions of Propargyl Alcohols
Authors: Hatzfeld Jana , Skowaisa Steffen , Jäckel Elisabeth , Kaufmann Julia , Haak Edgar
Published: September 2021

Various triaminocyclopentadienyl ruthenium complexes have been synthesized from Ru3(CO)12. The new complexes were tested for their ability to catalyze cascade conversions of propargyl alcohols. Their associated catalytic activities complement the activities of known diaminocyclopentadienone ruthenium complexes. In particular, the substrate scope of catalytic cycloadditions with 3‐ketolactones or phloroglucinol derivatives is extended to terpenoid‐derived propargyl alcohols containing an internal alkyne moiety. A wide range of cyclic terpenoid and phloroglucinol adducts are obtained by complementary application of both types of catalysts.
Development of Ultranarrow‐Bore Open Tubular High Efficiency Liquid Chromatography
Authors: Zhou Yingyan , Guo Guangsheng , Wang Xiayan
Published: September 2021

Comprehensive Summary

Chromatography theory shows that when the inner diameter of the chromatography column is very narrow (e.g., 1—2 μm), the maximum efficiency will be produced in liquid chromatography. In addition, the increasing demand for ultrasmall volume sample analysis has produced the trend of narrowing the diameter of the liquid chromatography column. Experiments have verified that ultranarrow‐bore open tubular liquid chromatography (i.d. ≤ 2 μm) has the advantages of small sample requirement and high separation efficiency. However, there also exist huge challenges along with such obvious advantages. This review summarizes the efforts made by our research group and other research groups to develop this field. We hope that in the near future, ultranarrow bore open‐tube liquid chromatography can be successfully and maturely applied to the application of analytes with ultrasmall size and volume such as single‐cell and even subcellular organelles omics research.

What is the most favorite and original chemistry developed in your research group?

Our research work originated from nanocapillary chromatographic analysis, and then expanded to micro/nanoscale bio‐separation analysis, micro/nanofluidic analysis, and the development of new micro/nano analytical instruments. Currently, our research focuses on single‐cell analysis with temporal and spatial resolution.

What is the most important personality for scientific research?

Having an enquiring mind; Be diligent, curious, and persistent; Pursuing perfection.

What's your hobbies? What's your favorite book(s)?

I enjoy cooking and playing Ping‐Pong. My favorite book is The Art of War.

Who influences you mostly in your life?

My parents.

What is your favorite journal(s)?

Journal of the American Chemical Society, which is the top international academic journal in the field of chemistry and values novelty.

Could you please give us some advices on improving Chinese Journal of Chemistry?

Pursue high quality, highlight the characteristics, strive for excellence, enable fast review and publication.
QoS‐aware trust establishment for cloud federation
Authors: Ahmed Usama , Al‐Saidi Asma , Petri Ioan , Rana Omer F.
Published: September 2021

Cloud federation enables inter‐layer resource exchanges among multiple, heterogeneous cloud service providers. This article proposes a Quality of Service (QoS) aware trust model for effective resource allocation in response to the various user requests within the Clouds4Coordination (C4C) federation system. This QoS mainly comprises of nine parameters combined into three categories: (i) node profile, (ii) reliability, and (iii) competence. Numerical values for these parameters are computed every ‘t’ seconds for each cloud provider. All values measured over an interval Δt are further processed by the proposed model to evaluate the utility associated with a provider (referred to as a discipline in the presented case study). The decision about interacting with a discipline in a collaborative project is based on this utility value. The systems architecture, evaluation methodology, proposed model, and experimental evaluation on a practical test bed is outlined. The proposed QoS‐aware trust evaluation mechanism allows selection of the most useful (based on a utility value) providers. The proposed approach can be used to support federation of cloud services across a number of different application domains.
Disruption of the biological activity of protease‐activated receptors2/4 in adults rather than children in SARS CoV‐2 virus‐mediated mortality in COVID‐19 infection
Authors: Singh Yogendra , Fuloria Neeraj Kumar , Fuloria Shivkanya , Subramaniyan Vetriselvan , Almalki Waleed Hassan , Gupta Gaurav , Shaikh Mohammad Arshad Javed , Singh Mahaveer , Al‐Abbasi Fahad A. , Kazmi Imran
Published: September 2021

One of the most remarkable results in 2019 is the reduced prevalence and death of children from coronavirus infection (COVID‐19). In 2019, a worldwide pandemic impacted around 0.1 billion individuals, with over 3.5 million mortality reported in the literature. There is minimal knowledge on SARS‐CoV‐2 infection immunological responses in kids. Studies have been focused mostly on adults and children since the course of pediatric sickness is often short. In adults, severe COVID‐19 is related to an excessive inflammatory reaction. Macrophages and monocytes are well known to contribute to this systemic response, although numerous lines are indicative of the importance of neutrophils. An increased number of neutrophils and neutrophil to lymphocyte ratios are early signs of SARS‐CoV‐2 and a worse prognosis. In this study that it is crucial to monitor PAR2 and PAR4 expression and function (since nursing children have elevated levels) and the inhibiting the normal physiology through the use of anticoagulants may exacerbate the problem in adults. Thus, in COVID‐19 infection, we propose the use of antiplatelet (thromboxane A2 inhibitors), if required rather than anticoagulants (FXa and thrombin Inhibitors).
Endoscopic balloon dilation for the prevention of severe strictures caused by acute esophageal necrosis
Authors: Jinushi Ryuhei , Ishii Naoki , Yano Takahiko , Imamura Noriatsu , Maekawa Hisato , Kamachi Kenichi
Published: September 2021

A 58‐year‐old man who had the history of alcohol dependence was referred to our emergency center due to severe nausea, vomiting, and subsequent onset of chest and back pain. Esophagogastroduodenoscopy (EGD) showed black‐appearing esophagus mucosa extending from the cervical esophagus to the esophagogastric junction with clear margins, a condition typically referred to as a black esophagus. Alcohol abuse was considered an important factor associated with acute esophageal necrosis in this patient. After admission, he received fluid resuscitation and proton‐pump inhibitors, with restriction of oral intake and treatment of alcohol dependence. Follow‐up EGDs and endoscopic balloon dilation were performed for the management of esophageal narrowing before the development of severe strictures. Strictures were successfully treated endoscopically without complications such as perforation.
A narrative review of systematic reviews on adherence to psoriasis treatments
Authors: Guraya Armaan , Rakita Uros , Porter Caroline L. , Feldman Steven R.
Published: September 2021

Introduction: Psoriasis is a prevalent disorder of the skin which presents with scaly, red plaques and leads to significant morbidity and mortality. Thus, successful treatment is of great importance to the patient and provider.

Objective: Nonetheless, a significant cause of treatment failure may not be incorrect diagnosis or treatment, but rather nonadherence. We aimed to elucidate what factors influence adherence to psoriasis treatments.

Methods: We conducted a review on the literature on adherence by adapting search terms derived from an existing systematic review (SR) on psoriasis adherence. Only data relevant to patients with psoriasis were extracted, including the type of medications they were using, when available. All of the factors associated with adherence were grouped by medication type and whether they had positive, negative, or no association with adherence, or mixed evidence.

Results: We found a unifying theme across SR was the wide heterogeneity in methodology of primary studies. There are pearls to be gleaned from this review, such as the power of a well‐written prescription, shared decision‐making, using effective treatments, having frequent follow‐up, and reframing adverse effects to improve adherence.

Conclusion: There is widespread prevalence of both mixed and contradicting conclusions across the SR, which may stem from the fact that studies on adherence vary extensively in their definition of adherence, their method for evaluating it, and their patient populations.
Novel nectar robbing negatively affects reproduction in Digitalis purpurea
Authors: Mackin Christopher R. , Goulson Dave , Castellanos Maria Clara
Published: September 2021

With many plant–pollinator interactions undergoing change as species’ distributions shift, we require a better understanding of how the addition of new interacting partners can affect plant reproduction. One such group of floral visitors, nectar robbers, can deplete plants of nectar rewards without contributing to pollination. The addition of nectar robbing to the floral visitor assemblage could therefore have costs to the plant´s reproductive output. We focus on a recent plant colonist, Digitalis purpurea, a plant that in its native range is rarely robbed, but experiences intense nectar robbing in areas it has been introduced to. Here, we test the costs to reproduction following experimental nectar robbing. To identify any changes in the behavior of the principal pollinators in response to nectar robbing, we measured visitation rates, visit duration, proportion of flowers visited, and rate of rejection of inflorescences. To find the effects of robbing on fitness, we used proxies for female and male components of reproductive output, by measuring the seeds produced per fruit and the pollen export, respectively. Nectar robbing significantly reduced the rate of visitation and lengths of visits by bumblebees. Additionally, bumblebees visited a lower proportion of flowers on an inflorescence that had robbed flowers. We found that flowers in the robbed treatment produced significantly fewer seeds per fruit on average but did not export fewer pollen grains. Our finding that robbing leads to reduced seed production could be due to fewer and shorter visits to flowers leading to less effective pollination. We discuss the potential consequences of new pollinator environments, such as exposure to nectar robbing, for plant reproduction.
Negative impacts of dominance on bee communities: Does the influence of invasive honey bees differ from native bees?
Authors: Garibaldi Lucas A. , Pérez‐Méndez Néstor , Cordeiro Guaraci D. , Hughes Alice , Orr Michael , Alves‐dos‐Santos Isabel , Freitas Breno M. , Freitas de Oliveira Favízia , LeBuhn Gretchen , Bartomeus Ignasi , Aizen Marcelo A. , Andrade Patricia B. , Blochtein Betina , Boscolo Danilo , Drumond Patricia M. , Gaglianone Maria Cristina , Gemmill‐Herren Barbara , Halinski Rosana , Krug Cristiane , Maués Márcia Motta , Piedade Kiill Lucia H. , Pinheiro Mardiore , Pires Carmen S. S. , Viana Blandina Felipe
Published: September 2021

Invasive species can reach high abundances and dominate native environments. One of the most impressive examples of ecological invasions is the spread of the African subspecies of the honey bee throughout the Americas, starting from its introduction in a single locality in Brazil. The invasive honey bee is expected to more negatively impact bee community abundance and diversity than native dominant species, but this has not been tested previously. We developed a comprehensive and systematic bee sampling scheme, using a protocol deploying 11,520 pan traps across regions and crops for three years in Brazil. We found that invasive honey bees are now the single most dominant bee species. Such dominance has not only negative consequences for abundance and species richness of native bees but also for overall bee abundance (i.e., strong “numerical” effects of honey bees). Contrary to expectations, honey bees did not have stronger negative impacts than other native bees achieving similar levels of dominance (i.e., lack of negative “identity” effects of honey bees). These effects were markedly consistent across crop species, seasons and years, and were independent from land‐use effects. Dominance could be a proxy of bee community degradation and more generally of the severity of ecological invasions.
Functional trait data for vascular plant species from northeastern North America
Authors: Waller Donald M. , Paulson Alison K. , Richards Jeannine H. , Alverson William S. , Amatangelo Kathryn L. , Bai Chengke , Johnson Sarah E. , Li Daijiang , Sonnier Grégory , Toczydlowski Rachel H.
Published: September 2021

Wisconsin's plant communities are responding to shifting disturbance regimes, habitat fragmentation, aerial nitrogen deposition, exotic species invasions, ungulate herbivory, and successional processes. To better understand how plant functional traits mediate species' responses to changing environmental conditions, we collected a large set of functional trait data for vascular plant species occupying Wisconsin forests and grasslands. We used standard protocols to make 76,213 measurements of 34 quantitative traits. These data provide rich information on genome size, physical leaf traits (length, width, circularity, thickness, dry matter content, specific leaf area, etc.), chemical leaf traits (carbon, nitrogen, phosphorus, potassium, calcium, magnesium, ash), life history traits (vegetative and flower heights, seed mass), and traits affecting plant palatability (leaf fiber, fat, and lignin). These trait values derive from replicate measurements on 12+ individuals of each species from multiple sites and 45+ individuals for a selected subset of species. Measurements typically reflect values for individuals although some chemical traits involved composite samples from several individuals at the same site. We also qualitatively characterized each species by plant family, woodiness, functional group, and Raunkiaer lifeform. These data allow us to characterize trait dimensionality, differentiation, and covariation among temperate plant species (e.g., leaf and stem economic syndromes). We can also characterize species' responses to environmental gradients and drivers of ecological change. With survey and resurvey data available from >400 sites in Wisconsin, we can analyze variation in community trait distributions and diversity over time and space. These data therefore allow us to assess how trait divergence vs. convergence affects community assembly and how traits may be related to half‐century shifts in the distribution and abundance of these species. The data set can be used for non‐commercial purposes. The data set is licensed as follows: CC‐By Attribution 4.0 International. We request users cite both the OSF data set and this Ecology data paper publication.
Density data for Lake Ontario benthic invertebrate assemblages from 1964 to 2018
Authors: Burlakova Lyubov E. , Karatayev Alexander Y. , Hrycik Allison R. , Daniel Susan E. , Mehler Knut , Rudstam Lars G. , Watkins James M. , Dermott Ronald , Scharold Jill , Elgin Ashley K. , Nalepa Thomas F. , Hinchey Elizabeth K. , Lozano Stephen J.
Published: September 2021

Benthic invertebrates are important trophic links in aquatic food webs and serve as useful bioindicators of environmental conditions because their responses integrate the effects of both water and sediment qualities. However, long‐term data sets for benthic invertebrate assemblages across broad geographic areas are rare and, even if collected, historic data sets are often not readily accessible. This data set provides densities of benthic macroinvertebrates for all taxa collected during lake‐wide surveys in Lake Ontario, a Laurentian Great Lake, from 1964 to 2018. This information resulted from surveys funded by the governments of the United States and Canada to investigate the status and changes of Lake Ontario benthic community. Of the 13 lake‐wide benthic surveys conducted in Lake Ontario over the course of 54 yr, we were able to acquire taxonomic data to the species level for 11 of the surveys and data to the group level for the other two surveys. Density data are provided for taxa representing the Annelida, Arthropoda, Mollusca, Cnidaria, Nemertea, and Platyhelminthes phyla. Univariate and multivariate analyses revealed that the compositional structure of Lake Ontario invertebrate assemblages differed markedly by depth and were also significantly altered by the Dreissena spp. invasion in early 1990s. The introduction of invasive dreissenids has changed the community historically dominated by Diporeia, Oligochaeta, and Sphaeriidae, to a community dominated by quagga mussels and Oligochaeta. Considering the rarity of long‐term benthic data of high taxonomic resolution in lake ecosystems, this data set could be useful to explore broader aspects of ecological theory, including effects of different environmental factors and invasive species on community organization, functional and phylogenetic diversity, and spatial scale of variation in community structure. The data set could also be useful for studies on individual species including abundance and distribution, species co‐occurrence, and how the patterns of dominance and rarity change over space and time. Use of this data set for academic or educational purposes is encouraged as long as the data source is properly cited using the title of this Data Paper, the names of the authors, the year of publication, the journal name, and the article number.
Alkali Metal Hexafluorido Plumbates(IV) A2[PbF6] (A=Na−Cs) and Luminescence of the Mn4+‐substituted Compounds A2[PbF6] : Mn (A=Li−Cs) and Li2[MF6] : Mn (M=Ti, Ge, Sn)
Authors: Bandemehr Jascha , Baumann Dominik , Seibald Markus , Kraus Florian
Published: September 2021

We synthesized eight novel red‐emitting Mn4+‐substituted phosphors of the compositions A2[PbF6] : Mn (A=Li−Cs) and Li2[MF6] : Mn (M=Ti, Ge, Sn) using a dry‐chemical fluorination process which completely avoids the usage of hydrofluoric acid. Compared with the commonly used red‐emitter K2[SiF6] : Mn (KSF) the two synthesized phosphors Na2[PbF6] : Mn and Li2[GeF6] : Mn show a blue‐shift of their emission maximum, Na2[PbF6] : Mn even by 4.2 nm. The compounds were characterized by powder X‐ray diffraction, IR and emission spectroscopy. Additionally, we present the crystal structures of the unsubstituted compounds A2[PbF6] (A=Na−Cs). Na2[PbF6] crystallizes in the trirutile structure type, whereas the other three are isotypic to K2[GeF6] (space group P
).
Systems thinking and complexity science–informed evaluation frameworks: Assessment of The Economics of Ecosystems and Biodiversity for Agriculture and Food
Authors: Bustamante María , Vidueira Pablo , Baker Lauren
Published: September 2021

Despite the increasing literature, applications, and discussions over the last 15 years, there remain questions about how to bring systems thinking and complexity science (STCS) into evaluation in ways that meaningfully enhance its practice, use, and results. One pathway forward is bridging the gap between the large STCS body of knowledge and evaluation practice by synthesizing STCS insights into actionable frameworks to support the work and role of those engaged in evaluation activities. This chapter aims to contribute to this challenge through two main goals. First, the authors develop an actionable STCS framework comprising ten guiding principles, identified through a review of STCS literature to support evaluation practitioners, researchers, and commissioners to bring STCS into evaluation. Secondly—and to test this STCS principles‐based framework—this chapter assesses the extent to which TEEBAgriFood, an STCS‐informed food systems evaluation framework, advances STCS into evaluation. Results provide learnings and insights about the use of STCS in evaluation design and practice.
Insights and future directions for systems and complexity‐informed evaluation
Authors: Walton Mat , Gates Emily F. , Vidueira Pablo
Published: September 2021

With the increasing maturity of systems thinking and complexity science (STCS) within evaluation, this issue of NDE provides case examples of contemporary application. This article identifies themes across case examples to identify emergent patterns and opportunities for the continued development of evaluation practices that draw upon STCS. Each article describes STCS and its applications within specific evaluation contexts. Our review across cases identified three themes: (1) the importance of setting boundaries around what is included and excluded from within the STCS field in a specific evaluation; (2) using STCS concepts and theories to enhance program and evaluation theory, and (3) broadly drawing upon STCS to support changes in systems and develop capacity within organizations. While these implications show some promise for systems and complexity informed evaluation, they, more importantly, underscore the need for deeper engagement with STCS theories and methods while simultaneously remaining accessible for evaluators.
Applying a systems and complexity lens to building evaluation capacity: Learning from a multicountry donor's experience
Authors: Vang KaYing , Moore Marah , Nicklin Claire
Published: September 2021

Although the evaluation field has increasingly integrated systems thinking and complexity science (STCS) into its work, little has been published on how capacity is built to do STCS‐informed evaluation. The chapter helps address this gap by exploring paired concepts drawn from the STCS and evaluation capacity building (ECB) literature: adaptive action and culture; boundaries and systems and structures; interrelationships and leadership; and perspectives and communication. The ideas are grounded with illustrative examples from a reflective case narrative of an international donor organization and the system surrounding it. Ultimately, the case shares how STCS can reimagine ECB and how increased capacity of the participants and organization can change the broader system.
Receptor‐targeting nanomaterials alleviate binge drinking‐induced neurodegeneration as artificial neurotrophins
Authors: Yang* Jingyu , Wang* Lirong , Huang Liwen , Che Xiaohang , Zhang Zhen , Wang Chunxiao , Bai Lihuan , Liu Ping , Zhao Yanan , Hu Xiaomei , Shi Bingyang , Shen Yuequan , Liang Xing‐Jie , Wu Chunfu , Xue Xue
Published: September 2021

The distinguished properties of nanomaterials promote us to explore whether their intrinsic activities would be beneficial to disease treatment. Furthermore, understanding the molecular mechanism is thereby crucial for biomedical applications. Here, we investigate the therapeutic effects of single‐walled carbon nanotubes (SWNTs) in a rat model of binge alcohol‐induced neurodegeneration. With selection from four types of SWNT structures, bundled SWNTs (bSWNTs) facilitated the recovery of learning and memory via enhancing neuroprotection and neuroregeneration. We screened the potential target for bSWNTs, and found that bSWNTs have the abilities to directly interact with neurotrophic receptors, especially tropomyosin‐related kinase B (TrkB). Moreover, similar to the actions of endogenous neurotrophins, bSWNTs could trigger the dimerization and phosphorylation of TrkB, while these conformational changes resulted in activating their downstream signals involved in neuroprotection and neuroregeneration. With relatively clear mechanisms, these “artificial neurotrophins” provide a proof‐of‐concept example as an efficiently therapeutic strategy for the treatment of neurodegenerative diseases.