bluuebunny/crossref_metadata_2025 huggingface dataset:
A failure mechanism consistency test method for accelerated degradation test
Authors: Zhai Guofu , Zheng Bokai , Ye Xuerong , Si Shuang , Zio Enrico
Published: August 2020

Accelerated degradation test (ADT) is generally used to accelerate degradation processes in products to estimate their lifespan and to assess their reliability in a short period of time. How to perform the failure mechanism consistency test is crucial in the application of the ADT method. Existing failure mechanism consistency test methods assume that degradation rates among individual products are the same. However, these methods do not take degradation dispersions caused by manufacturing technologies into consideration. To address this issue, a failure mechanism consistency test method for ADT based on the activation energy invariant method and the likelihood ratio test is proposed. First, a degradation modeling method for ADT is introduced. Then, the logarithmic maximum likelihood function values of the degradation models are estimated based on the two‐step maximum likelihood estimation (MLE) method. Finally, the decision rule is proposed based on the likelihood ratio test. The method mentioned above is, then, used on the real degradation data of carbon‐film resistors and bullet O‐rings, and its effectiveness is verified. Furthermore, based on the failure mechanism change point in RTV5370 siloxane rubbers, the simulated degradation data are degenerated to compare the proposed method with the method not considering individual differences in different ADT programs and degradation dispersions.
Rapid computational evaluation of small‐molecule hydrolase mimics for preorganized H‐bond networks
Authors: Öner Alara , Çelebi‐Ölçüm Nihan
Published: August 2020

Spirocyclic oligomers formed by coupling chiral cyclic building blocks carrying the catalytic machinery of hydrolases (spiroligozymes) catalyze the transesterification of vinyl trifluoromethylacetate with methanol but suffer from the lack of enzyme‐like preorganization of their catalytic functionalities in a well‐defined geometry via H‐bond networks. The computational protocol presented herein combines different levels of theories to rapidly explore structural modifications for an improved structural preorganization. Calculations predict that a modification as simple as replacing the five‐membered building block holding the alcohol moiety with a six‐membered analog in spiroligozymes significantly increases the occupancy of the H‐bond between the benzyl alcohol‐pyridine nucleophilic dyad that mimics the Ser‐His‐Asp/Glu triad of hydrolases. The computed energy profile is indicative of faster acylation of this derivative compared to the parent spiroligozyme and highlights the importance of inclusion of an oxyanion hole motif for efficient catalysis.
Experiments on the hydraulics and swimming responses of juvenile Chinook Salmon encountering a floating guidance structure
Authors: Swanson Samuel T. , Tullos Desiree D. , Goodwin R. Andrew
Published: August 2020

Floating guidance structures are intended to promote safe passage for juvenile salmon migrating downstream through reservoirs. However, the ability of an engineered structure to guide fish to safe passage has been primarily tested through large‐scale implementation in reservoirs or in laboratory studies and computer simulations without live fish. Research is needed that integrates fluid mechanics with fish behaviour to study how hydraulic conditions around a guidance structure trigger swimming behaviours. In this study, an outdoor experimental channel was used to identify: (a) the hydraulic signature of a floating guidance structure and (b) changes in fish swim behaviour in relation to channel hydraulics. The flow field surrounding a guidance structure at two deployment angles was characterized using acoustic Doppler velocimeters. Swimming behaviours of juvenile Chinook salmon were recorded using underwater videogrammetry. A statistical method for behaviour change detection identified the most likely locations of swimming behaviour changes in fish as they first encountered the guidance structure. Finally, the locations of behaviour changes were compared to the hydraulics surrounding each guidance structure. Taken together, results indicated the fish did respond to the guide wall with behaviour changes, but did not distinguish between the two guide wall angles. While the two guide wall angles did produce statistically different distributions of hydraulic variables, the differences were small, potentially too small for the fish to produce a behavioural response. To inform the design of guidance structures, further work may clarify if swim responses vary with more aggressive wall angles and/or higher approach velocities, or if any contraction of flow and/or visual cue will produce similar behaviour responses.
Assessing ethical consumer behavior for sustainable development: The mediating role of brand attachment
Authors: Rasool Shahid , Cerchione Roberto , Salo Jari
Published: August 2020

Despite being ethically concerned, sometimes ethically minded consumers opted for unethical brands. This research aims to uncover the underlying reasons and the role of self‐congruence theory to bridge this intention‐behavior gap. This paper analyses the impact of actual self‐concept (ASC) and ideal self‐congruence (ISC) on different dimensions of ethically minded consumer behavior (EMCB) in presence of brand attachment (BA) as mediator. Structural equation modeling (SEM) is used to investigate these issues in a sample of 674 respondents. The results reveal that the positively significant relationship of the ASC and ISC with the dimensions of EMCB is negatively mediated by BA. For managers, findings offer a strategical direction and real‐world approach to improving BA and ethical concerns simultaneously without exploiting customer's actual self while promising a strong customer value. This study develops holistic theoretical model that addresses the intention‐behavior gap in sustainable development literature and enhances the understanding of self‐congruence and ethically minded consumption where brands are involved.
BILITE: A Bayesian randomized phase II design for immunotherapy by jointly modeling the longitudinal immune response and time‐to‐event efficacy
Authors: Guo Beibei , Zang Yong
Published: August 2020

Immunotherapy—treatments that target a patient's immune system—has attracted considerable attention in cancer research. Its recent success has led to generation of novel immunotherapeutic agents that need to be evaluated in clinical trials. Two unique features of immunotherapy are the immune response and the fact that some patients may achieve long‐term durable response. In this article, we propose a two‐arm Bayesian adaptive randomized phase II clinical trial design for immunotherapy that jointly models the longitudinal immune response and time‐to‐event efficacy (BILITE), with a fraction of patients assumed to be cured by the treatment. The longitudinal immune response is modeled using hierarchical nonlinear mixed‐effects models with possibly different trajectory patterns for the cured and susceptible groups. Conditional on the immune response trajectory, the time‐to‐event efficacy data for patients in the susceptible group is modeled via a time‐dependent Cox‐type regression model. We quantify the desirability of the treatment using a utility function and propose a two‐stage design to adaptively randomize patients to treatments and make treatment recommendations at the end of the trial. Simulation studies show that compared with a conventional design that ignores the immune response, BILITE yields superior operating characteristics in terms of the ability to identify promising agents and terminate the trial early for futility.
Rechargeable Calcium–Sulfur Batteries Enabled by an Efficient Borate‐Based Electrolyte
Authors: Li Zhenyou , Vinayan Bhaghavathi Parambath , Diemant Thomas , Behm Rolf Jürgen , Fichtner Maximilian , Zhao‐Karger Zhirong
Published: August 2020

Rechargeable metal–sulfur batteries show great promise for energy storage applications because of their potentially high energy and low cost. The multivalent‐metal based electrochemical system exhibits the particular advantage of the feasibility of dendrite‐free metal anode. Calcium (Ca) represents a promising anode material owing to the low reductive potential, high capacity, and abundant natural resources. However, calcium–sulfur (Ca–S) battery technology is in an early R&D stage, facing the fundamental challenge to develop a suitable electrolyte enabling reversible electrochemical Ca deposition, and at the same time, sulfur redox reactions in the system. Herein, a study of a room‐temperature Ca–S battery by employing a stable and efficient calcium tetrakis(hexafluoroisopropyloxy) borate Ca[B(hfip)4]2 electrolyte is presented. The Ca–S batteries exhibit a cell voltage of ≈2.1 V (close to its thermodynamic value) and good reversibility. The mechanistic studies hint at a redox chemistry of sulfur with polysulfide/sulfide species involved in the Ca‐based system.
Rational Design of FeNi Bimetal Modified Covalent Organic Frameworks for Photoconversion of Anthropogenic CO2 into Widely Tunable Syngas
Authors: Han Bin , Ou Xinwen , Zhong Zuqi , Liang Shujie , Deng Hong , Lin Zhang
Published: August 2020

Direct photoconversion of low‐concentration CO2 into a widely tunable syngas (i.e., CO/H2 mixture) provides a feasible outlet for the high value‐added utilization of anthropogenic CO2. However, in the low‐concentration CO2 photoreduction system, it remains a huge challenge to screen appropriate catalysts for efficient CO and H2 production, respectively, and provide a facile parameter to tune the CO/H2 ratio in a wide range. Herein, by engineering the metal sites on the covalent organic frameworks matrix, low‐concentration CO2 can be efficiently photoconverted into tunable syngas, whose CO/H2 ratio (1:19–9:1) is obviously wider than reported systems. Experiments and density functional theory calculations indicate that Fe sites serve as the H2 evolution sites due to the much stronger binding affinity to H2O, while Ni sites act as the CO production sites for the higher affinity to CO2. Notably, the widely tunable syngas can also be produced over other Fe/Ni‐based bimetal catalysts, regardless of their structures and supporting materials, confirming the significant role of the metal sites in regulating the selectivity of CO2 photoreduction and providing a modular design strategy for syngas production.
Rapid and Controllable Synthesis of Nanocrystallized Nickel‐Cobalt Boride Electrode Materials via a Mircoimpinging Stream Reaction for High Performance Supercapacitors
Authors: Zhang Qingcheng , Zhao Junping , Wu Yechao , Li Jun , Jin Huile , Zhao Shiqiang , Chai Lulu , Wang Yahui , Lei Yong , Wang Shun
Published: August 2020

Nickel‐cobalt borides (denoted as NCBs) have been considered as a promising candidate for aqueous supercapacitors due to their high capacitive performances. However, most reported NCBs are amorphous that results in slow electron transfer and even structure collapse during cycling. In this work, a nanocrystallized NCBs‐based supercapacitor is successfully designed via a facile and practical microimpinging stream reactor (MISR) technique, composed of a nanocrystallized NCB core to facilitate the charge transfer, and a tightly contacted Ni‐Co borates/metaborates (NCBi) shell which is helpful for OH− adsorption. These merits endow NCB@NCBi a large specific capacity of 966 C g−1 (capacitance of 2415 F g−1) at 1 A g−1 and good rate capability (633.2 C g−1 at 30 A g−1), as well as a very high energy density of 74.3 Wh kg−1 in an asymmetric supercapacitor device. More interestingly, it is found that a gradual in situ conversion of core NCBs to nanocrystallized Ni‐Co (oxy)‐hydroxides inwardly takes place during the cycles, which continuously offers large specific capacity due to more electron transfer in the redox reaction processes. Meanwhile, the electron deficient state of boron in metal‐borates shells can make it easier to accept electrons and thus promote ionic conduction.
Conceptualising, extracting and analysing requirements arguments in users' forums: The CrowdRE‐Arg framework
Authors: Ali Khan Javed , Liu Lin , Wen Lijie , Ali Raian
Published: August 2020

Due to the pervasive use of online forums and social media, users' feedback are more accessible today and can be used within a requirements engineering context. However, such information is often fragmented, with multiple perspectives from multiple parties involved during on‐going interactions. In this paper, the authors propose a Crowd‐based Requirements Engineering approach by Argumentation (CrowdRE‐Arg). The framework is based on the analysis of the textual conversations found in user forums, identification of features, issues and the arguments that are in favour or opposing a given requirements statement. The analysis is to generate an argumentation model of the involved user statements, retrieve the conflicting‐viewpoints, reason about the winning‐arguments and present that to systems analysts to make informed‐requirements decisions. For this purpose, the authors adopted a bipolar argumentation framework and a coalition‐based meta‐argumentation framework as well as user voting techniques. The CrowdRE‐Arg approach and its algorithms are illustrated through two sample conversations threads taken from the Reddit forum. Additionally, the authors devised algorithms that can identify conflict‐free features or issues based on their supporting and attacking arguments. The authors tested these machine learning algorithms on a set of 3,051 user comments, preprocessed using the content analysis technique. The results show that the proposed algorithms correctly and efficiently identify conflict‐free features and issues along with their winning arguments.
Are Product Owners communicators? A multi‐method research approach to provide a more comprehensive picture of Product Owners in practice
Authors: Unger‐Windeler Carolin , Klünder Jil Ann‐Christin , Reuscher Timothy , Schneider Kurt
Published: August 2020

Product Owners have an important role in the agile and hybrid software development process. While this role is supposed to maximize the value of a product, there seem to be several scattered results on how they achieve this, as well as what actually constitutes this role in practice. To consolidate current research results and to further analyze the key attribute of Product Owners, we conducted a multi‐method research approach spanning a systematic mapping study and a consecutive case study in a hybrid development environment.

The results of the mapping study states that Product Owners are communicators. We further investigated on this and used the shadowing technique to observe three Product Owners' communication activities. The results support that statement, as the gained data reveal that Product Owners spend 65% of their time in meetings. But rather than just providing the team with the necessary requirements for the product under development, Product Owners need this time to synchronize and align their work, streamline the agile process of large‐scale Scrum, discuss team‐based topics, and to solve upcoming issues addressed by the team. These results contribute to draw a more comprehensive picture of the important but yet complex role of Product Owners in practice.
Diagnostic performance of ultrasound to differentiate perforated from non‐perforated paediatric appendicitis: A narrative review
Authors: Conwell Nancy K. , Kennedy Narelle J. , Quinton Ann E.
Published: August 2020

Appendicitis is the most common reason for urgent paediatric surgery, with significantly higher rates of appendiceal perforation in young children. Distinct management plans are required for perforated and non‐perforated appendicitis and thus accurate differentiation is crucial. Ultrasound is a safe imaging modality that avoids ionising radiation exposure to children and is useful for diagnosis of appendicitis. The aim of this review is to explore the diagnostic performance of ultrasound for detecting perforated paediatric appendicitis and to determine the sonographic findings useful for distinguishing perforated from non‐perforated appendicitis in the paediatric population. Ultrasound demonstrates high specificity ranging from 90% to 100%, but low sensitivity ranging from 23% to 44% for differentiating perforated from non‐perforated appendicitis in children. Sonographic findings significantly associated with perforated paediatric appendicitis include an abscess, loculated or complex intraperitoneal fluid, an appendicolith, dilated bowel and thickening of the terminal ileum, all of which demonstrate high specificity but low sensitivity. The high specificity of ultrasound indicates that it is a useful diagnostic tool to rule out perforated appendicitis and differentiate it from non‐perforated appendicitis in children.
Speciation in Cisco with Emphasis on Secondary Contacts, Plasticity, and Hybridization
Authors: Eshenroder Randy L. , Jacobson Peter C.
Published: August 2020

The Cisco Coregonus artedi is a planktivorous fish that is widely distributed in lakes across glaciated areas of North America. With retreat of Laurentide ice, Cisco dispersed from refugia into a vast network of meltwater (proglacial) lakes that eventually receded, stranding populations in depressions—today’s lakes. Refugial populations also colonized lakes that fell outside of the footprint of a proglacial lake. These two types of Cisco lakes, those inside the footprint of a proglacial lake and those outside the footprint, though uncounted, number in the high hundreds or more. All 53 lakes reported to contain sympatric forms of Cisco occur in previously inundated lakes; no sympatric forms occur in lakes that were not inundated. We reviewed Laurentide zoogeography to assess whether secondary contacts in the proglacial lakes were extensive enough to account for the distribution of sympatric lakes. We concluded that secondary contacts had been more extensive in the proglacial lakes than detected in genetic studies of Cisco. We inferred that secondary contacts in the proglacial lakes resulted in more plastic, diverse phenotypes than were found in lakes not inundated and that these phenotypes were more capable of divergence than were phenotypes inhabiting lakes not inundated. Secondary contacts in the proglacial lakes appear to have been limited to shallow‐water forms of Cisco. Deepwater forms likely did not evolve until after the proglacial lakes receded, as meltwater appears to have been trophically unsuitable for pelagic fishes like Cisco. Cisco are assumed to have colonized meltwater lakes by “hopscotching” between inlets, thereby avoiding prolonged existence in meltwater. Sympatric populations of Cisco are rare in comparison with the number of allopatric populations, even in inundated lakes, indicating that divergence occurs under specialized conditions. Canalization appears to have diminished the evolvability of contemporary forms as compared to their ancestors. Hybridization within Cisco species pairs appears to be the norm and is aggravated by anthropogenically induced events.
Chinese cross‐border mergers and acquisitions in the developing world: Is Africa unique?
Authors: Gunessee Saileshsingh , Hu Shuang
Published: August 2020

China has emerged as an important partner for Africa. Not surprisingly, Chinese business and investment relations with Africa have been growing. This article contends that Africa offers a different proposition to Chinese business interests in non‐African developing economies. In this optic, it takes a “comparative” institution‐based view treating factors that determine Chinese multinationals' cross‐border merger and acquisition (CBMA) decisions as comparatively different for Africa to the rest of the developing world. From a panel data estimation of the number of Chinese CBMAs from 2007 to 2016, we find among market size, natural resources, strategic assets, labor productivity, and institutional governance, only natural resources and market size have a distinctive effect, with Chinese investors being more attracted to African natural resources than the African market. The drive for natural resources provides impetus for Chinese MNEs to choose CBMAs over greenfield investment, and through majority ownership to exercise control. Our inference is that Africa is “significantly” different from other developing regions, in terms of CBMAs, as Chinese multinationals have a strong motive to control access to natural resources.
Clearance of amyloid‐beta with bispecific antibody constructs bound to erythrocytes
Authors: Taylor Ronald P. , Lindorfer Margaret A. , Atkinson John P.
Published: August 2020

We propose use of bispecific monoclonal antibody (mAb) complexes bound to erythrocytes to redress the lack of efficacy of anti‐amyloid beta mAbs in Alzheimer's disease treatment. Our paradigm leverages erythrocyte complement receptor 1 to promote rapid and quantitative removal of amyloid beta from the circulation, and its subsequent removal from the brain as well.
Developing Adaptive Expertise at Facilitating Dialogic Text Discussions
Authors: Zook‐Howell Dena , Matsumura Lindsay Clare , Walsh Marguerite W. , Correnti Richard , Bickel Donna DiPrima
Published: August 2020

Facilitating rigorous and interactive (dialogic) classroom text discussions that build reading comprehension skills requires advanced forms of expertise and skills. The authors describe three different ways that discussions can evolve when practicing teachers take up the work of making their discussions more dialogic. The authors then describe some ways that teachers can reflect on these challenges to support professional learning and enhance classroom text discussion quality.
Becoming Brave Spellers
Authors: Schrodt Katie , FitzPatrick Erin , Elleman Amy
Published: August 2020

Research has indicated that adding mind‐set and self‐regulation strategy instruction to the writers’ workshop framework may improve motivation, independence, and academic success in young writers. Invented spelling can strengthen the relation between phonological and orthographic representations. The authors examined the impact of growth mind‐set instruction on writing using a strategy of “brave spelling” to encourage students to use invented spelling skills to increase the sophistication of their writing. The authors combined research on invented spelling and growth mind‐set to create unique lesson plans focused on the development of word‐reading skills, alphabetic knowledge, and phonological awareness. In 10 weeks, 12 kindergartners bravely spelled 240 different words that conventionally contain five or more letters. This research was incorporated into the “brave spelling” lesson plan. The authors explore how creating a culture of brave spellers is one strategy for helping students write any words they can imagine.
High‐throughput computational design of halide perovskites and beyond for optoelectronics
Authors: Li Yuheng , Yang Kesong
Published: August 2020

Halide perovskites have attracted great interest as promising next‐generation materials in optoelectronics, ranging from solar cells to light‐emitting diodes. Despite their exceptional optoelectronic properties and low cost, the prototypical organic–inorganic hybrid lead halide perovskites suffer from toxicity and low stability. Therefore, it is of high demand to search for stable and nontoxic alternatives to the hybrid lead halide perovskites. Recently, high‐throughput computational materials design has emerged as a powerful approach to accelerate the discovery of new halide perovskite compositions or even novel compounds beyond perovskites. In this review, we discuss how this approach discovers halide perovskites and beyond for optoelectronics. We first overview the background of halide perovskites and methodologies in high‐throughput computational design. Then, we focus on materials properties for different optoelectronic applications, and how they are assessed with materials descriptors. Finally, we review different studies in terms of specific materials types to discuss their design principles, screening results, and experimental verification.

This article is categorized under:

Structure and Mechanism > Computational Materials Science

Electronic Structure Theory > Density Functional Theory
Concluding Discussion: The Past, Present, and Future of Technical Universities
Authors: Broström Anders , Geschwind Lars , Larsen Katarina
Published: August 2020

Higher education institutions identified as ‘technical universities’ enjoy considerable status in many countries. Yet studies of boundary negotiations from a range of settings suggest that opportunities to transform into a broader, research-based university often takes precedence over the alternative vision of remaining or moving towards becoming a focused technical university. In this chapter, we discuss alternative explanations for the lacklustre appeal of the latter type of institutional template, and outline a roadmap for how the historical legacy of the technical university may be cultivated.
Abflussentstehung – wie aus Niederschlag Abfluss wird
Authors: Seibert Simon P. , Auerswald Karl
Published: August 2020

Oberflächenabfluss entsteht durch Regen, wenn die Rückhaltemöglichkeiten auf Pflanzen und Bodenoberfläche erschöpft sind und die Infiltrationsrate kleiner als die Regenintensität wird. Um für planerische Fragen mit überschaubarem Aufwand die Abflussreaktion abzuschätzen, haben sich stark vereinfachte Verfahren etabliert. Empfohlen und genauer vorgestellt wird eine Weiterentwicklung des Curve-Number-Verfahrens. Letztes ist einfach, weltweit etabliert und für Planungszwecke hinreichend genau. Eine wesentliche Neuerung ist, dass monatliche Werte unterschiedlicher Ackerkulturen unter deutschen Anbaubedingungen und von Grünland, Wald, Siedlungs- und Verkehrsflächen vorgestellt werden. Sie verbessern nicht nur die Abbildung mittlerer Bedingungen, die für Planungszwecke relevant sind, sondern erlauben auch eine Modellierung des Jahresverlaufs, der sich unweigerlich durch die Bewirtschaftung, sich ändernde Bodenfeuchte und sich ändernde Bodenbedeckung ergibt. Damit kann auch die Wirkung von Ansatzpunkten zur Reduktion des Abflussvolumens quantitativ abgeschätzt werden, die in der Landnutzung, der Flächenparzellierung und der landwirtschaftlichen Bewirtschaftungspraxis vorhanden sind. Darüber hinaus werden Empfehlungen zur Wahl geeigneter Bemessungsniederschläge in ländlichen Gebieten gegeben.
Abflusskonzentration – wie Abfluss in der Fläche gebündelt und beschleunigt wird
Authors: Seibert Simon P. , Auerswald Karl
Published: August 2020

Ausgehend von der Wasserscheide bis in die größeren Gewässer bündelt sich Oberflächenabfluss zunehmend entlang des Fließpfades und beschleunigt dabei. Die allgemeinen Grundprinzipien und Einflussgrößen dieser Beschleunigung werden vorgestellt, typische Abflussformen und Fließpfade in kleinen, ländlichen Einzugsgebieten erläutert und die hydraulischen Grundlagen und Methoden zur Berechnung von Fließgeschwindigkeit und Fließzeit beschrieben.
Unerkannte letale idiopathische Riesenzellmyokarditis – ein Fallbericht
Authors: Birngruber C. G. , Hochscheid C. , Dettmeyer R. B.
Published: August 2020

Myokarditiden stellen nach der hypertrophen Kardiomyopathie und der stenosierenden Koronararteriensklerose die dritthäufigste Ursache des plötzlichen Herztodes dar. Die Klinik der Myokarditis ist wie ihr Verlauf äußerst variabel, und ihr Therapieerfolg hängt stark von der Ätiologie und somit einer umfassenden diagnostischen Abklärung ab. Zum Goldstandard gehört nach wie vor die Endomyokardbiopsie, deren Ergebnisse bedeutenden Einfluss auf die Therapieplanung haben können. Vorgestellt wird der Fall einer 35 Jahre alt gewordenen Frau, bei der zu Lebzeiten eine chronisch aktive lymphozytäre Myokarditis mit Nachweis des humanen Herpesvirus 6 (HHV 6) diagnostiziert wurde. Acht Monate nach der Diagnose verstarb sie unerwartet. Die Obduktion mit nachfolgender histopathologischer Aufarbeitung der Myokardproben erbrachte den Nachweis einer Riesenzellmyokarditis, die als Differenzialdiagnose zu Lebzeiten nicht gestellt worden war. Der Fall verdeutlicht die Problematik der Diagnosestellung zu Lebzeiten, wenn Myokardproben nicht repräsentativ sind zum Nachweis der Grunderkrankung und illustriert die autoptischen Befunde dieser seltenen Form der Myokarditis.
Percutaneous Cholecystostomy Placement in Cases of Non‐operative Cholecystitis: A Retrospective Cohort Analysis
Authors: Gandhi Karan , Du Plessis Rimon , Klopper Juan , Kloppers Christo
Published: August 2020

Background

Acute (calculous) cholecystitis (AC) is an extremely common surgical presentation, managed by cholecystectomy. Percutaneous cholecystostomy (PC) is an alternative; however, its safety and efficacy, along with subsequent cholecystectomy, are underreported in South Africa, where patients often present late and access to emergency operating theatre is constrained. The aim of the study was to demonstrate the outcomes of PC in patients with AC not responding to antimicrobials.

Materials and methods

A retrospective cohort review of patient records, who underwent PC in Groote Schuur Hospital, Cape Town, between May 2013 and July 2016, was performed. Patients with PC for malignancy or acalculous cholecystitis were excluded. Technical success, clinical response, procedure‐related morbidity and mortality were recorded. Interval LC parameters were investigated.

Results

Technical success and clinical improvement was seen in 29 of 37 patients (78.38%) who had PC. Malposition (8.11%) was the most common complication. Two patients required emergency surgery (5.4%), while one tube was dislodged. Median tube placement duration was 25 days (range 1–211). Post‐procedure, 16 patients (43.24%) went on to have LC, of which 50% (eight patients) required conversion to open surgery and 25% (four) had subtotal cholecystectomy. Median surgical time was 130 min. There were no procedure‐related mortalities but eight patients (21.62%) died in the 90‐day period following tube insertion.

Conclusion

In patients with AC, PC is safe, with high technical success and low complication rate. Subsequent cholecystectomy should be performed, but is usually challenging. The requirement for PC may predict a more complex disease process.
Oceanic sediment accumulation rates predicted via machine learning algorithm: towards sediment characterization on a global scale
Authors: Restreppo Giancarlo A. , Wood Warren T. , Phrampus Benjamin J.
Published: August 2020

Observed vertical sediment accumulation rates (n = 1031) were gathered from ~ 55 years of peer reviewed literature. Original methods of rate calculation include long-term isotope geochronology (14C,210Pb, and137Cs), pollen analysis, horizon markers, and box coring. These observations are used to create a database of global, contemporary vertical sediment accumulation rates. Rates were converted to cm year−1, paired with the observation’s longitude and latitude, and placed into a machine learning–based Global Predictive Seabed Model (GPSM). GPSM finds correlations between the data and established global “predictors” (quantities known or estimable everywhere, e.g., distance from coastline and river mouths). The result, using a k-nearest neighbor (k-NN) algorithm, is a 5-arc-minute global map of predicted benthic vertical sediment accumulation rates. The map generated provides a global reference for vertical sedimentation from coastal to abyssal depths. Areas of highest sedimentation, ~ 3–8 cm year−1, are generally river mouth proximal coastal zones draining relatively large areas with high maximum elevations and with wide, shallow continental shelves (e.g., the Gulf of Mexico and the Amazon Delta), with rates falling exponentially towards the deepest parts of the oceans. The exception is Oceania, which displays significant vertical sedimentation over a large area without draining the large drainage basins seen in other regions. Coastal zones with relatively small drainage basins and steep shelves display vertical sedimentation of ~ 1 cm year−1, which is limited to the near shore when compared with shallow, wide margins (e.g., the western coasts of North and South America). Abyssal depth rates are functionally zero at the time scale examined (~ 10−4 cm year−1) and increase one order of magnitude near the Mid-Atlantic Ridge and at the Galapagos Triple Junction.
Outcomes after appendectomy in children with acute appendicitis treated at a tertiary paediatric centre: results from a retrospective cohort study
Authors: Knaapen Max , van Amstel Paul , van Amstel Tim , The Sarah-May M. L. , Bakx Roel , van Heurn Ernest L. W. E. , Gorter Ramon R.
Published: August 2020

Purpose

In general, an appendectomy is presumed to have a limited burden of disease. However, in current literature, reported complication rates vary. This study aims to provide additional insights in the incidence of post-appendectomy complications in children with acute appendicitis.

Methods

This retrospective cohort study included children (0–17 years old) that underwent appendectomy at our tertiary referral centre for suspected acute appendicitis (January 2011–December 2018). Children referred to our centre, and those that underwent non-operative treatment were excluded. Post-appendectomy complications were recorded from electronic medical charts using predefined definitions and classified as severe (Clavien-Dindo III–IV) or less severe (Clavien-Dindo I–II).

Results

A total of 131 children were included. Simple and complex appendicitis was diagnosed in 66 (50%) and 60 (46%) children, respectively. A non-inflamed appendix was seen in five (4%) children. One or more complications were identified in 33 (25%) patients. Eight (12%) children with simple appendicitis developed a complication, three of these were severe. In children with complex appendicitis, 23 (38%) children developed a complication, 14 of these were severe.

Conclusion

This study shows a high rate of complications compared with current literature, both in children with simple and complex appendicitis. This is probably the result of our definition of complications and being a tertiary referral centre receiving more severe appendicitis cases. However, these results still show that appendectomy is not always a routine procedure with only few complications. Substantiating the need to keep optimizing treatment for children with appendicitis.
Do isolates from pharyngeal and rectal swabs match blood culture bacterial pathogens in septic VLBW infants? A pilot, cross-sectional study
Authors: Capasso Letizia , Maddaluno Sergio , Coppola Clara , Dolce Pasquale , di Cola Giuseppe Schiano , Sierchio Enrico , Borrrelli Angela Carla , Bagattini Maria , Esposito Eliana Pia , Zarrilli Raffaele , Antonaki Eleni , Catania Maria Rosaria , Raimondi Francesco
Published: August 2020

Serial body site swabbing is used to monitor horizontal spread of aggressive bacterial species in the neonatal intensive care unit (NICU). Since colonization/carriage is thought to precede systemic infection, one might expect to retrieve colonizing pathogens from blood cultures. This hypothesis, however, has not been fully investigated in very low birth weight (VLBW) infants that are at high sepsis’ risk. The primary outcome was, in a population of VLBW infants with late-onset sepsis, the matching between blood culture results and pathogens isolated from rectal and nose/pharyngeal surveillance swabs in the preceding 2 weeks. The secondary outcomes were the site of swabbing and time interval from colonization to blood culture positivity. Out of 333 VLBW neonates, 80 (24%) were diagnosed with bacterial sepsis. In 46 (57%) neonates, the blood culture showed the same pathogen species cultured from a swab. Of these, 30 were isolated from infants with both body sites colonized with an average time interval of 3.5 days; 2/16 were isolated from rectal swabs and 14 /16 from nose/pharyngeal samples.

Conclusion: Our data show a fair correspondence between bacteria colonizing the nasopharynx and/or the rectum and pathogens later isolated from blood cultures. This association depends on the swabbing site, number of sites, and pathogen species. Although these data constitute valuable results, they are not sufficient for providing the sole base of a thoughtful clinical decision.

What is Known:• Body site’s colonization may precede systemic infection.• Little is known on this mechanism in VLBW infants that are at higher sepsis’ risk.What is New:•Colonizing bacteria partially correspond to pathogens of blood cultures in VLBW infants with sepsis.• Correspondence depends on swabbing site, number of sites, and pathogen species.
Smoking habits and detection rate of unruptured intracranial aneurysms and incidence rate of subarachnoid haemorrhage in Norway between 2008 and 2015
Authors: Majewska Paulina , Gulati Sasha , Øie Lise , Salvesen Øyvind , Müller Tomm B. , Solheim Ole
Published: August 2020

Objective

The aim of this study was to investigate the detection rate of unruptured intracranial aneurysms (UIAs) and incidence of aneurysmal subarachnoid haemorrhage (SAH) in relation to the rapidly changing smoking rates in Norway between 2008 and 2015.

Methods

The registry-based study included all patients (≥ 16 years old) admitted to a hospital in Norway between 2008 and 2015 with a primary diagnosis of aneurysmal SAH or an outpatient diagnosis of UIAs. Age group–specific and total detection rate of UIAs and incidence rate of SAH over the years were calculated. Age group–specific data on smoking habits was retrieved from a national annual survey representative of the whole Norwegian population.

Results

The rate of daily smokers decreased by 48% between 2008 and 2015. The detection rate of UIAs decreased by 47% from 17.3 in 2008 to 9.3 per 100,000 persons in 2015, and the incidence of SAH decreased by 30% from 11.3 in 2008 to 7.9 per 100,000 persons in 2015. The average annual decline in prevalence of daily smoking, UIA detection rate, and SAH incidence was 6.9%, 6.7%, and 4.3% per year, respectively. Multinomial logistic regression analyses revealed that the correlation between the decline in estimated daily smoking rates and decline in detection rate of UIAs (hazard ratio 52.5 CI = (14.9,∞), p < 0.00001) and incidence of SAH (hazard ratio 11.8 CI=(5.6,32.5), p < 0.00001) are statistically significant. The association is particularly strong in young and middle-aged cohorts (< 66 years old).

Conclusion

It is likely that reducing cigarette smoking on a population-based level strongly reduces the rates of UIAs and SAH.
Mutual relations between jasmonic acid and acibenzolar-S-methyl in the induction of resistance to the two-spotted spider mite (Tetranychus urticae) in apple trees
Authors: Warabieda Wojciech , Markiewicz M. , Wójcik D.
Published: August 2020

The possibility of inducing resistance to the two-spotted spider mite, Tetranychus urticae Koch, in ‘Gala’ apple trees growing under optimal fertilization or nitrogen-deficiency conditions was investigated. The effects of jasmonic acid (JA) at 1.5 and 2.5 mM, and acibenzolar-S-methyl (benzothiadiazole, BTH) at 0.5 and 1.5 mM, applied separately or together, on the fecundity of T. urticae females in a laboratory test as well as on the population growth of the pest in a greenhouse experiment were determined. The influence of both elicitors on the induction of LOX and PAL gene expression was assessed in a parallel experiment using real-time PCR. Jasmonic acid showed significantly higher effectiveness in inducing apple tree resistance to T. urticae, as compared to BTH. This was particularly evident in the reduction in pest numbers that was observed in the greenhouse experiment and was also confirmed by increased LOX gene expression after treatment with JA. BTH induced the expression of the PAL gene more strongly than jasmonic acid; however, this was not reflected in the performance of the two-spotted spider mite in the laboratory and greenhouse experiments. It was also found that the antagonistic effect of BTH on JA might lead to decreased effectiveness of the jasmonic acid used to induce apple tree resistance to the two-spotted spider mite. Although nitrogen fertilization stimulated the development of spider mite populations, the resistance induction mechanism was more effective in N-fertilized plants, which was especially evident at the higher jasmonic acid concentration.
The Development and Process Evaluation of a 3-Day Acceptance and Commitment Therapy Group Program for Adolescent Cancer Survivors
Authors: Clarke Kristina , Patterson Pandora , McDonald Fiona E. J. , Wakefield Claire E. , Sansom-Daly Ursula , Zebrack Brad
Published: August 2020

Background

Adolescents diagnosed with cancer experience unique psychosocial concerns that persist beyond treatment completion into longer-term survivorship. Camp-based, group Acceptance and Commitment Therapy (ACT) programs are a potential model for providing evidence-informed psychological and peer support to adolescent cancer survivors.

Objective

This paper describes the development and exploration of the feasibility and acceptability of such a program, Places You’ll Go. This manualised program incorporates five 90-min group ACT sessions within a 3-day camp, teaching ACT strategies in the context of psychosocial impacts of cancer.

Method

Eight facilitators and twenty-eight Australian adolescent cancer survivors (68% female; age range 12–17 years, M = 15.4 years) participated in the program and evaluation. Feasibility was assessed using facilitator-reported session duration, attendance, quality and content fidelity; facilitators also completed interviews after program completion. Young people completed surveys on program acceptability at the end of each session and at program completion.

Results

All planned sessions were delivered, with 97% attendance and high fidelity in manualised program delivery. All young people were mostly or very satisfied and would recommend the program to another cancer survivor. Opportunities for peer connection and skill development contributed to perceived program acceptability.

Conclusions

The Places You’ll Go program was acceptable and feasible to deliver. It is a promising community-based model for promoting peer support and well-being in adolescent cancer survivors, indicating the potential of ACT-based approaches for this population. Further work is underway to evaluate whether the program improves psychosocial wellbeing among participants, and if this is linked to the therapeutic mechanisms underpinning ACT.
Oxidative degradation of non-recycled and recycled paper
Authors: Coppola Floriana , Modelli Alberto
Published: August 2020

The degradation of paper-based materials involves several and complex mechanisms, such as hydrolysis and oxidation. The behaviour of different types of pulps can be very variable. In this study, the difference upon oxidation of contemporary non-recycled and recycled papers, which now constitute a considerable fibre source, is investigated. A 0.015 M potassium periodate solution is used to oxidise five types of paper, two non-recycled and three recycled, for 0.5, 1, 2 and 4 h. The effects of such oxidation treatments are evaluated in terms of carbonyl content and degree of polymerisation (DP). A modified procedure of the Szabolcs’s method and viscometry are used to measure the carbonyl content and DP, respectively. The carbonyl groups are found to increase more rapidly in the recycled papers than in the non-recycled ones. On the contrary, oxidation causes a larger decrease of the DP values in the non-recycled papers, the paper made of pure cellulose being the most sensitive in terms of depolymerisation. The DP values measured for pure cellulose paper are in line with previously reported data. Moreover, in accordance with the Ekenstam equation, the plots of the reciprocal of DP as a function of oxidation time show good linear correlations for all types of paper investigated. Pseudo rate constants are thus calculated from the slopes of these plots, those of the non-recycled papers being found to be higher than those of the recycled papers.

Graphic abstract
Effects of the antidepressant fluoxetine on pigment dispersion in chromatophores of the common sand shrimp, Crangon crangon: repeated experiments paint an inconclusive picture
Authors: Ford Alex T. , Feuerhelm Eleanor
Published: August 2020

The effects of antidepressants in the environment are starting to generate considerable interest due to the fact that neurotransmitters influence a range of biological processes. Crypsis is an important behavioural and physiological response in many crustaceans modulated by monoamine and pigment dispersing/concentrating hormones. This study aimed to develop a test methodology and investigate the effects of the selective serotonin reuptake inhibitor (SSRI), fluoxetine, on a chromatophore index and overall carapace ‘darkness’ in the common sand shrimp Crangon crangon. Adult shrimp were exposed for either 1 h, 1 day or 1 week across a range of nominal fluoxetine concentrations (10 ng/L, 100 ng/L and 1000 ng/L) and the chromatophore index or carapace percentage ‘darkness’ was recorded following 30 min on white and black substrates. These experiments were repeated three times using different specimens. Animals became significantly darker (~20%) on darker background and lighter on light backgrounds as one might expect. However, time periods over which the animals were recorded had a significant impact on the colouration suggesting habituation to laboratory conditions. Fluoxetine exposure came up as a significant factor in two of the three trials for the chromatophore index but the results was inconsistent between trials. There was a high degree of correlation between the chromatophore index and the percentage darkness analyses however, there was no significant effects for fluoxetine exposure with the percentage darkness data. We conclude that the effects on antidepressants on colour change remain inconclusive from these experiments and we discuss potential areas to improve the repeatability of the experiments.
Relative Reduction in Prevalence (RRP): An Alternative to Cohen’s Effect Size Statistics for Judging Alcohol, Cigarette, and Marijuana Use Prevention Outcomes
Authors: Hansen William B.
Published: August 2020

Jacob Cohen developed two statistical measures for judging the magnitude of effects produced by an intervention, known as Cohen’s d, appropriate for assessing scaled data, and Cohen’s h, appropriate for assessing proportions. These have been widely employed in evaluating the effectiveness of alcohol, cigarette, marijuana, and other drug prevention efforts. I present two tests to consider the adequacy of using these statistics when applied to drug use prevention programs. I used student survey data from grades 6 through 12 (N = 1,963,964) collected by the Georgia Department of Education between 2015 and 2017 and aggregated at the school level (N = 1036). I calculated effect sizes for an imaginary drug prevention program that (1) reduced 30-day alcohol, cigarette, and marijuana prevalence by 50%; and (2) maintained 30-day prevalence at a pretest level for multiple years. While both approaches to estimating intervention effects represent ideal outcomes for prevention that surpass what is normally observed, Cohen’s statistics failed to reflect the effectiveness of these approaches. I recommend including an alternative method for calculating effect size for judging program outcomes. This alternative method, Relative Reduction in Prevalence (RRP), calculates ratio differences between treatment and control group drug use prevalence at posttest and follow-up, adjusting for differences observed at pretest. RRP allows researchers to state the degree to which an intervention could be viewed as efficacious or effective that can be readily understood by practitioners.
A note on the zeros of approximations of the Ramanujan $$\Xi $$-function
Authors: Chirre Andrés , Castañón Oswaldo Velásquez
Published: August 2020

In this paper we review the study of the distribution of the zeros of certain approximations for the Ramanujan $$\Xi $$
Ξ
-function given by Ki (Ramanujan J 17(1):123–143, 2008), and we provide new proofs of his results. Our approach is motivated by the ideas of Velásquez (J Anal Math 110:67–127, 2010) in the study of the zeros of certain sums of entire functions with some condition of stability related to the Hermite–Biehler theorem.