bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of Ultraviolet B Light‐Emitting Diodes with Single or Triple Quantum Wells
Authors: Kolbe Tim , Knauer Arne , Ruschel Jan , Rass Jens , Kyong Cho Hyun , Hagedorn Sylvia , Glaab Johannes , Lobo Ploch Neysha , Einfeldt Sven , Weyers Markus
Published: May 2021

Light‐emitting diodes (LEDs) with an emission wavelength of 310 nm containing either a single or a triple quantum well are compared regarding their efficiency and long‐term stability. In addition, the influence of the thickness of the lower quantum well barrier and the quantum well thickness in single quantum well (SQW) LEDs is investigated. Electroluminescence measurements show a 28% higher initial output power for the SQW LEDs compared with the triple quantum well (TQW) LEDs because of larger spatial overlap of the carriers in the SQW as revealed by electro‐optical simulations of the LED heterostructures. However, TQW LEDs show a higher output power than SQW LEDs after 1 h operation under harsh conditions. For SQW LEDs, it is found that for a thicker lower quantum well barrier (65 nm instead of 25 nm) the initial output power decreases by ≈15%. A thicker SQW (3 nm instead of 1.6 nm) reduces the initial output power by even 45% but increases the lifetime by a factor of 6 which is attributed to reduced Auger recombination from an enhanced spatial separation of electrons and holes in the quantum wells due to the quantum‐confined Stark effect.
Design and Analysis of a Polarization‐Insensitive and Wide‐Angle Ultrabroadband Metamaterial Absorber
Authors: Luo Zhiyou , Ji Shijun , Zhao Ji , Wu Han , Dai Handa
Published: May 2021

Herein, a polarization‐insensitive and wide‐angle characteristic ultrabroadband metamaterial absorber (UBMMA) is reported, which covers the entire X band and Ku band and parts of the C band and K band. The standard unit cell of the UBMMA is designed based on the frustum of a cone with a through‐hole, and it is composed of multiple metal and dielectric layers by cross. The calculation results indicate that the absorptivity of the proposed UBMMA is more than 85% from 6.65 to 23.73 GHz except for the frequency bands 13.10–13.20 and 15.38–15.73 GHz, and the absorptivity is more than 90% in the frequency bands 6.65–12.25 and 20.33–23.33 GHz. The distributions of the electric field, magnetic field, and surface current are calculated and analyzed, and the absorbing mechanism of the UBMMA is explained. The UBMMA is insensitive to the transverse electric and transverse magnetic polarization, and it displays an agreeable absorption effect under high incident angles. The influence of important geometric parameters on the absorption performance of the UBMMA is studied. Because of the satisfactory ultrabroadband absorption performance of the UBMMA, it can be applied in the fields of satellite radar, broadband antennae, and electromagnetic shielding.
Multistate Magnetic Domain Wall Devices for Neuromorphic Computing
Authors: Sbiaa Rachid
Published: May 2021

In recent years, neuromorphic computing has been intensively investigated, to take over the conventional or von Neumann scheme. Herein, the advantages of memristors as neurons and synapses are discussed. After a brief introduction to biological neurons and synapses, focus is put on spin‐based devices, including magnetic tunnel junction (MTJ) and domain wall devices. Certain materials and device designs aim at mimicking synapses’ functionality, whereas others gather both neurons and synapses. The advancements in spin‐based memory applications are of great advantage for neuromorphic computing and their implementation is presented herein.
p‐Type Doping and Alloying of CuI Thin Films with Selenium
Authors: Storm Philipp , Bar Michael Sebastian , Selle Susanne , von Wenckstern Holger , Grundmann Marius , Lorenz Michael
Published: May 2021

The impact of the intentional selenium doping of CuI thin films is investigated concerning crucial crystalline, electrical and optical properties. For selenium contents in between 0.1 at.% and 1 at.%, the carrier density can be systematically adjusted by the selenium supply during growth between cm and cm while transparency and crystallinity remain unaffected. By temperature‐dependent Hall‐effect measurements, a carrier freeze out is observed and the binding energy of the selenium dopant is determined. The long‐term electrical stability in combination with cappings is significantly improved compared to undoped or oxygen doped CuI. However, for selenium contents exceeding 1 at.%, major crystalline changes are observed that are presumably correlated to a phase transformation. Transmission and electrical measurements suggest that the solubility limit of Se in CuI is about 1 at.% since a degradation of the transparency and decreasing free hole densities are observed for Se contents exceeding 1 at.%. Hence, the doping limit for Se in CuI corresponds to 1 at.%.
Solutions of the Eliassen balance equation for inertially and/or symmetrically stable and unstable vortices
Authors: Wang Shanghong , Montgomery Michael T. , Smith Roger K.
Published: May 2021

Two methods for solving the Eliassen equation for the corresponding balanced secondary circulation of a numerically simulated, high‐resolution tropical cyclone vortex are compared. In idealized calculations for a symmetrically stable vortex, both methods (successive overrelaxation [SOR] and multigrid) converge and the solutions are broadly similar. In more typical cases, where the vortex has regions of inertial or symmetric instability, it is necessary to coarsen the data from the numerical simulation to determine the balanced secondary circulation. A convergent solution can be obtained with the multigrid method for a finer grid spacing than with the SOR method. However, the multigrid method fails to converge when the vertical grid spacing is similar to that of the numerical simulation. Results using both methods confirm the inability of the balance formulation to capture the strong inflow and resulting tangential wind spin‐up in the frictional boundary layer during a period of rapid intensification. Typical tropical cyclone simulations show an inflow layer just beneath the upper‐level outflow layer, and the corresponding balanced secondary circulation may show such an inflow layer also. However, caution is called for in attributing this inflow layer to a balanced flow response driven by the distribution of diabatic heating and tangential momentum forcing. Our study suggests that this inflow layer is likely an artifact of the ad hoc regularization procedure that is necessary to keep the Eliassen equation globally elliptic in regions of inertial and/or symmetric instability.
Benchmarking Quantum Chemistry Computations with Variational, Imaginary Time Evolution, and Krylov Space Solver Algorithms
Authors: Yeter‐Aydeniz Kübra , Gard Bryan T. , Jakowski Jacek , Majumder Swarnadeep , Barron George S. , Siopsis George , Humble Travis S. , Pooser Raphael C.
Published: May 2021

Quantum chemistry is a key application area for noisy‐intermediate scale quantum (NISQ) devices, and therefore serves as an important benchmark for current and future quantum computer performance. Previous benchmarks in this field have focused on variational methods for computing ground and excited states of various molecules, including a benchmarking suite focused on the performance of computing ground states for alkali‐hydrides under an array of error mitigation methods. State‐of‐the‐art methods to reach chemical accuracy in hybrid quantum‐classical electronic structure calculations of alkali hydride molecules on NISQ devices from IBM are outlined here. It is demonstrated how to extend the reach of variational eigensolvers with symmetry preserving Ansätze. Next, it is outlined how to use quantum imaginary time evolution and Lanczos as a complementary method to variational techniques, highlighting the advantages of each approach. Finally, a new error mitigation method is demonstrated which uses systematic error cancellation via hidden inverse gate constructions, improving the performance of typical variational algorithms. These results show that electronic structure calculations have advanced rapidly, to routine chemical accuracy for simple molecules, from their inception on quantum computers a few short years ago, and they point to further rapid progress to larger molecules as the power of NISQ devices grows.
Intercropping kura clover with prairie cordgrass grown on a marginal land enhanced soil carbon and nitrogen fractions
Authors: Abagandura Gandura Omar , Kumar Sandeep
Published: May 2021

Prairie cordgrass (PCG) (Spartina pectinata Link) has been the focus of much scientific attention recently for use in biofuel applications, as it grows well on marginal lands that are unsuitable for row crops. This study investigated how the intercropping of kura clover (KC) (Trifolium ambiguum M. Bieb) with PCG for 8 yr affects soil carbon (C) and nitrogen (N) fractions compared with N fertilization on marginally yielding croplands in South Dakota. This study was initiated in 2011 with five treatments: intercropping PCG with KC (PCG‐KC), and PCG with N fertilizer at four levels: 0 kg N ha–1 (PCG‐0N), 75 kg N ha–1 (PCG‐75N), 150 kg N ha–1 (PCG‐150N), and 225 kg N ha–1 (PCG‐225N). Soil samples were collected in 2018 and analyzed for permanganate oxidizable C and N, stable C and N, mineralized C and N, dissolved organic C and N, and particulate organic C and N. Further, C and N management indices were calculated from these data. Results showed that permanganate oxidizable C and N and particulate organic C and N were generally higher under PCG‐KC than under PCG‐0N and PCG‐75N but similar to PCG‐150N and PCG‐225N. Dissolved organic C and N and C mineralization were higher under PCG‐KC compared with fertilized and unfertilized PCG. Prairie cordgrass–kura clover (190.10) recorded a 91% higher N management index than PCG‐75N (99.66) but was similar to PCG‐150N (165.70) and PCG‐225N (163.10). This study concludes that growing KC–PCG mixture rather than using N fertilizers would have an overall positive effect on marginally yielding cropland soils.
Thoughts on “AIDSandCOVID‐19: A Tale of Two Pandemics and the Role of Statisticians” by Susan S. Ellenberg and Jeffrey S. Morris
Authors: Gail Mitchell H.
Published: May 2021

Human immunodeficiency virus and Covid‐19 (or SARS‐CoV‐2) differ in their incubation distributions and in their susceptibility to immunologic defense. These features affect our ability to predict the course of these epidemics and to control them.
AIDS and COVID: A tale of two pandemics and the role of statisticians
Authors: Ellenberg Susan S. , Morris Jeffrey S.
Published: May 2021

The world has experienced three global pandemics over the last half‐century: HIV/AIDS, H1N1, and COVID‐19. HIV/AIDS and COVID‐19 are still with us and have wrought extensive havoc worldwide. There are many differences between these two infections and their global impacts, but one thing they have in common is the mobilization of scientific resources to both understand the infection and develop ways to combat it. As was the case with HIV, statisticians have been in the forefront of scientists working to understand transmission dynamics and the natural history of infection, determine prognostic factors for severe disease, and develop optimal study designs to assess therapeutics and vaccines.
Comment
Authors: Follmann Dean
Published: May 2021

Common themes from the AIDS and COVID‐19 pandemics are reviewed from the vantage point of a statistician at the National Institutes of Health.
Semiparametric analysis of zero‐inflated recurrent events with a terminal event
Authors: Ma Chenchen , Hu Tao , Lin Zhantao
Published: May 2021

Recurrent event data frequently arise in longitudinal studies and observations on recurrent events could be terminated by a major failure event such as death. In many situations, there exist a large fraction of subjects without any recurrent events of interest. Among these subjects, some are unsusceptible to recurrent events, while others are susceptible but have no recurrent events being observed due to censoring. In this article, we propose a zero‐inflated generalized joint frailty model and a sieve maximum likelihood approach to analyze zero‐inflated recurrent events with a terminal event. The model provides a considerable flexibility in formulating the effects of covariates on both recurrent events and the terminal event by specifying various transformation functions. In addition, Bernstein polynomials are employed to approximate the unknown cumulative baseline hazard (intensity) function. The estimation procedure can be easily implemented and is computationally fast. Extensive simulation studies are conducted and demonstrate that our proposed method works well for practical situations. Finally, we apply the method to analyze myocardial infarction recurrences in the presence of death in a clinical trial with cardiovascular outcomes.
A structured Review of Quality of Life in Advanced and High-Risk Cutaneous Squamous Cell Carcinoma Shows the Need for More Studies and Better Measures
Authors: Starkings R. , Shilling V. , Jenkins V. , Fallowfield L.
Published: May 2021

Background

Cutaneous squamous cell carcinoma (cSCC) accounts for nearly a quarter of non-melanoma skin cancers. Studies reporting Quality of Life (QoL) in this group focus on early stage disease. A small proportion of cSCC patients have high-risk or advanced disease, with potentially significant QoL impacts, yet are largely overlooked.

Aims

This structured review appraises measures and published QoL outcomes in this group.

Materials & Methods

We conducted searches in MEDLINE, EMBASE, CINAHLplus and PsycInfo in June 2020 (updated in October) to identify publications specifically reporting QoL outcomes in this cohort. Returns were reviewed against a strict set of eligibility criteria.

Results

We identified seven publications for inclusion; three relating to high-risk cSCC, three to metastatic disease and one to unresectable disease. Publications were appraised for quality using the Mixed Methods Appraisal Tool. Only one fulfilled more than two of the five quality criteria. Studies employed a range of patient reported outcome measures to assess QoL, both generic and disease specific.

Discussion

All studies with multiple time-points reported stable or improving QoL, however extrapolation of these findings to the cSCC population is not warranted due to study limitations including mixed populations, incomplete data sets or single measurements. We set out to review the QoL literature for high-risk and advanced cSCC and found a small and disparate body of evidence. Studies varied significantly in terms of study population, design and quality. While the identified studies suggested stable or improving QoL, we question the choice of measures used and highlight the need for further work in this area.

Conclusion

While there are some published reports about quality of life for patients with early stage cutaneous squamous cell carcinoma, these impacts for the high-risk or advanced cohort are largely unexplored. We conducted a structured review of published measures and outcomes used in this cohort and found a demonstrable need for further, targeted, exploration of patient needs in this area.
CEO early‐life disaster experience and corporate social performance
Authors: O'Sullivan Don , Zolotoy Leon , Fan Qingliang
Published: May 2021

Research Summary

Despite an extensive upper echelons literature on how CEOs' prior experiences influence firm behavior, we know little about the influence of traumatic experiences early in CEOs' lives. Drawing on post‐traumatic growth theory, we describe how traumatic experiences early in CEOs' lives influence corporate social performance. Our theory points to the asymmetric impact of CEO early‐life trauma on responsible and irresponsible corporate social performance and to two boundary conditions: CEO age at the time of the traumatic event and the severity of the event. We develop and test our arguments in the context of large‐scale disasters experienced early in the CEO's life. Our findings advance strategic management research on the relationship between CEO experiences and firm outcomes.

Managerial Summary

We consider how traumatic experiences in childhood shape CEO cognition and values and, therefore, firm behavior. Our findings suggest that CEOs who have had to deal with traumatic early‐life events may gain psychological strength from such experiences and that their psychological growth informs firm conduct. Specifically, our findings indicate that experience of trauma early in the CEO's life is positively associated with corporate social performance. The implication is that boards aspiring to enhance this aspect of corporate performance may wish to consider the early‐life experiences of prospective CEOs. While early‐life experiences are unlikely to feature on a prospective CEO's résumé, the typical selection process for senior executive appointments is well placed to unearth executives' life histories.
Recent Developments in Flexible Thermoelectric Devices
Authors: Yang Shiqi , Qiu Pengfei , Chen Lidong , Shi Xun
Published: May 2021

Flexible thermoelectrics, including flexible thermoelectric materials and devices, can directly convert the heat from human body into useful electricity, providing a promising solution for uninterrupted power to wearables. In the past decade, flexible thermoelectrics has achieved notable progress. Various kinds of flexible thermoelectric materials have been developed and some of them have been fabricated into flexible thermoelectric devices, showing the ability to generate nW‐level or even μW‐level electricity. Herein, the basic design principles and typical configurations of flexible thermoelectric devices, as well as the requirements on thermoelectric materials to achieve high performance flexible thermoelectric devices, are first introduced. Then, the recent progress achieved in flexible thermoelectric devices based on organics materials, traditional inorganic materials, other organic/inorganic composites/hybrids, and plastic deformable inorganic semiconductors, respectively, are summarized. Finally, an outlook on the future development of flexible thermoelectrics is briefly given. This study sheds light on the further development of flexible thermoelectrics.
Feasibility of a Full Chalcopyrite Tandem Solar Cell: A Quantitative Numerical Approach
Authors: Tiwari Kunal J. , Giraldo Sergio , Placidi Marcel , Gon Medaille Axel , Thomere Angelica , Resalati Shahaboddin , Saucedo Edgardo , Jehl Li-Kao Zacharie
Published: May 2021

The potential of tandem solar cells combining two chalcopyrite absorbers is evaluated using numerical modeling based on an exhaustive set of experimental parameters, offering a high degree of confidence in the numerical values reported herein. The simple yet reliable approach used here combines a transfer matrix‐based optical model of the wide bandgap CIGSe top subcell used as input for the 1D electrical modeling of a reference narrow bandgap CIGSe bottom cell. Various optical optimizations to the top subcell are investigated, with the aim to increase the bottom subcell current and reduce the efficiency threshold needed at the top subcell for the tandem device to beat the current single junction efficiency record. The results here suggest that significant progress compared with the state of the art can be made using a pure CuGaSe2 absorber combined with an optimized back contact with an ultrathin transition metal oxide interlayer. With a bottom subcell current more than doubled in the optimum top subcell configuration, a challenging yet clear pathway for the future realization of tandem solar cells based on chalcopyrite absorbers is offered.
Phosphorus Partition Between Liquid Crude Steel and High‐Basicity Basic Oxygen Furnace Slags
Authors: Kovtun Oleksandr , Karbayev Meirzhan , Korobeinikov Iurii , Srishilan C , Shukla Ajay Kumar , Volkova Olena
Published: May 2021

The phosphorus partition between the unkilled liquid crude steel and the high basicity (CaO/SiO2 = 4.2), basic oxygen furnace (BOF) slags with varying compositions of Al2O3, TiO2, and MnO is studied at temperatures 1600 and 1650 °C. The tests are conducted in both “slag‐to‐metal” and “metal‐to‐slag” directions and for durations of 30 and 60 min. The measured results are compared with the values reported in literature and found to be in good agreement with some of them. It is found in the investigation of high‐basicity BOF slags, that Al2O3, MnO, and TiO2 lower the phosphorus partition. The phosphorus partition increases with increasing optical basicity. The phosphorus partition shows a maximum when the FeO content is in range of 25–30 mass%. The MgO content slightly increases the phosphorus partition.
In Situ X‐Ray Diffraction Analysis of Microstructure Evolution during Deep Cryogenic Treatment and Tempering of Tool Steels
Authors: Cui Chengsong , Dong Juan , Epp Jérémy , Schulz Alwin , Steinbacher Matthias , Acar Serdal , Herbst Sebastian , Maier Hans Jürgen
Published: May 2021

Deep cryogenic treatment of tool steels, incorporated in conventional hardening and tempering, has been a topic of intensive research in recent years. Yet, the governing microstructural mechanisms involved in the deep cryogenic treatment of high‐alloyed tool steels are still controversial. Thus, an in situ X‐ray diffraction study is conducted on three tool steels X38CrMoV5‐3, X153CrMoV12, and ~X190CrVMo20‐4 to shed light on microstructural evolution during cryogenic treatment and subsequent tempering. For these high‐alloyed tool steels, the transformation of retained austenite into martensite is detected during the cooling phase of the cryogenic treatment. A change in tetragonality of martensite occurs mainly in the heating phase of the subsequent tempering process, which indicates the diffusion of carbon and carbide precipitation from the martensite. The microstructure evolution of the tool steels after hardening, cryogenic treatment, and tempering is further examined by scanning electron microscopy.
Process Routes of Low‐Ni Liquefied Natural Gas Tank Steel with Excellent Cryogenic Toughness
Authors: Chen Qi-Yuan , Zhang Wei-Na , Ren Jia-Kuan , Wang Meng , Xie Zhang-Long , Chen Jun , Liu Zhen-Yu
Published: May 2021

Herein, several treatments, including modified quenching and tempering (QT) treatment, ultrafast cooling and tempering (UFC‐T) treatment, and ultrafast cooling, intercritical quenching, and tempering (UFC‐LT) treatment, are used to prepare low‐Ni steels and compared with conventional QT treatment. All the three treatments enable low‐Ni steel to achieve equivalent or better cryogenic toughness than 9% Ni steel. The toughening effect of modified QT treatment is better than that of UFC‐T treatment, which is attributed to the increase in density of high‐angle grain boundaries (HAGBs). For modified QT treatment, fine equiaxed prior austenite grains and weak variant selection of martensite transformation lead to higher density HAGBs. Although the coarse elongated prior austenite grains in UFC‐T treatment are beneficial to Bain grouping and not conducive to matrix refinement, the intercritical quenching step in UFC‐LT treatment further increases the density of HAGBs due to the jagged prior austenite grain boundaries (PAGBs) and fresh martensite formed along PAGBs. Therefore, UFC‐LT treatment achieves high‐density HAGBs and excellent cryogenic toughness similar to modified QT treatment. Due to the wider tempering temperature process window, UFC‐LT treatment is the optimal process route for low‐Ni liquefied natural gas tank steel.
Die rechnerische Bestimmung der Dämpfung von Stahl‐Eisenbahnbrücken – Teil 2: Verifizierung anhand von Bestandsbrücken
Authors: Stollwitzer Andreas , Fink Josef
Published: May 2021

Werden an Eisenbahnbrücken Messungen zur Bestimmung der dynamischen Parameter Eigenfrequenz und Dämpfung durchgeführt, ist hinsichtlich der Dämpfung häufig eine signifikante Diskrepanz zwischen Messung und normativer Vorgabe zu beobachten. Die EN 1991‐2 schreibt für dynamische Berechnungen konservative Dämpfungsmaße vor, welche als untere Grenze der in der Realität zu erwartenden Dämpfung kommuniziert werden und damit stark auf der sicheren Seite liegen. In Teil 1 zum vorliegenden Beitrag wurden für zwei vorab definierte Brückenmodelle neue Ansätze hergeleitet, welche es ermöglichen, die Dämpfung von Eisenbahnbrücken rechnerisch zu ermitteln. Diese Rechenmodelle werden nun durch einen Vergleich mit aus Messdaten identifizierten dynamischen Parametern von 13 bestehenden Stahl‐Eisenbahnbrücken verifiziert. Ein Vergleich zwischen Rechnung und Messung veranschaulicht einerseits die erhebliche Abweichung zwischen normativ vorgeschriebener und real vorhandener Dämpfung. Andererseits wird gezeigt, dass die in Teil 1 vorgestellten Ansätze realitätsnahe Ergebnisse liefern und eine evidenzbasierte Alternative zur Norm darstellen. Dadurch werden Potenziale für eine Minimierung der Diskrepanz zwischen Messung und Rechnung aufgezeigt und eine Grundlage zur realitätsnahen rechnerischen Bestimmung der Dämpfung geschaffen.
Presumed septic sacroiliitis in a puppy with unilateral hind limb lameness and sciatic nerve neuropathy
Authors: Goh Derniese , House Arthur
Published: May 2021

A 5‐month‐old female entire Dachshund presented with an acute onset of left hind limb lameness following intense play. There were concurrent intermittent neurological deficits in the left hind limb, and pain in the lumbosacral region and on dorsal flexion of the tail. Computed tomography (CT) imaging revealed an asymmetric widening of the left sacroiliac joint with loss of cortical margins, accompanied by mild osteolytic changes of the adjacent ilium and sacrum highly suggestive of septic sacroiliitis. There was also perilesional steatitis in the region of the sciatic nerve. An 8‐week course of antimicrobial therapy was prescribed. Complete resolution of all clinical signs was noted at a 7‐month follow up. Sacroiliitis should be considered as a differential for unilateral hind limb lameness with or without intermittent sciatic neuropathy in a puppy in the absence of other orthopaedic conditions.
Heroin intoxication in a dog
Authors: McDermott Fergal M. , Henriksson Andrea E. , Wismer Tina A.
Published: May 2021

An 11‐month‐old intact male boxer cross was presented unconscious following oral heroin consumption. At home, intramuscular naloxone given by the owner showed no obvious improvements. Intravenous naloxone given in the hospital quickly reversed the clinical signs. The owners were not able to afford hospitalisation and the animal was discharged against medical advice. No signs of rebound opioid toxicity were reported. This case report describes the clinical presentation and treatment of a case of heroin intoxication in a dog.
Baseflow and transmission loss: A review
Authors: McMahon Thomas A. , Nathan Rory J.
Published: May 2021

There is an extensive literature dealing with the interaction between groundwater and surface water, and this includes major reviews on baseflow, transmission losses, baseflow recession analysis, and broader aspects of low flows. Although these are mature topics in hydrology, they continue to attract strong interest, with hundreds of papers published in leading journals over the past 20 years. Our comprehensive review of the relevant literature focusses in detail on the use of linear and nonlinear models of recession discharge, and on transmission loss. From this review we identify three approaches to understanding recession, namely (a) theoretical approaches based on the Boussinesq equation, (b) applications of recession slope analysis, and (c) estimates of transmission loss by input–output water balance. We review the application of these techniques to ephemeral and humid areas and note the wide adoption of linear models despite most researchers accepting that the processes are nonlinear. Few papers address the characteristics of groundwater flow to ephemeral streams from unconfined aquifers. Although initially considered an ephemeral arid/semi‐arid stream feature, transmission loss occurs in streams in humid areas. Interestingly, we identify a significant omission in the literature, in that while it is common to observe nonlinear behavior in streamflow recessions, little explicit account has been given to the role of transmission loss which can be an important factor in identifying the structure of nonlinear recession models.

This article is categorized under:

Science of Water > Hydrological Processes
Synthesis and characterization of second‐generation phosphorus‐nitrogen PN3P‐rhodium (I) pincer complexes via ligand post‐modification
Authors: Zhou Chunhui , Hu Jinsong , Chakraborty Priyanka , Huang Kuo‐Wei
Published: May 2021

A pseudo‐dearomatized PN3P*Rh−CO complex reacts with various alkyl/benzyl halides to furnish a series of second‐generation PN3P‐pincer carbonyl complexes via the ligand post‐modification strategy. These synthesized complexes were fully characterized by NMR, FTIR, HRMS, and single‐crystal X‐ray crystallography. A plausible mechanism for the formation of 2nd‐generation PN3P complexes was proposed based on the isolation of the minor dialkylated products.
Tridentate NPN Ligands with a Central Secondary Phosphine Oxide Donor and their Corresponding Metal Complexes
Authors: Keske Eric C. , Sattler Madeleine O. , Lough Alan J. , Morris Robert H.
Published: May 2021

Three new Ru complexes with N‐P(OH)‐N donor ligands were synthesized and characterized. A ruthenium complex with a ligand with quinolinyl side arms exhibited monodentate coordination through the phosphorus atom with an intramolecular POH⋅⋅⋅N(quinolinyl) hydrogen bond but with no interaction between nitrogen donors and the ruthenium center. Two pentamethylcyclopentadienyl ruthenium complexes with a ligand with pyridyl side arms exhibited fac‐κ3‐NPN’ tridentate coordination to the metal center, one with an interionic POH⋅⋅⋅FPF5 hydrogen bond in the crystal. A paramagnetic nickel [Ni3(N‐P(O)‐N)4] cluster was also characterized; the crystal structure shows three nickel centers in two different environments. The central nickel is coordinated to four deprotonated ligands, two are bidentate κ2‐NO, two are monodentate κ‐O and is connected to the other two nickel centers by two sets of bridging μ2‐O,P moieties. Non‐central nickel centers are each coordinated to one bidentate ligand κ2‐PN and one monodentate ligand κ‐P.
The effect of the drying method on the cell wall structure and sorption properties of waterlogged archaeological wood
Authors: Broda Magdalena , Curling Simon F. , Frankowski Marcin
Published: May 2021

Drying is a process affecting various wood properties, including its structure, moisture behaviour and mechanical properties. Since waterlogged wooden artefacts usually constitute priceless objects of cultural heritage, understanding the effect of drying on the complex interactions between the wood ultrastructure and the resulting properties is necessary to ensure their proper conservation. Hence, this was the aim of the present study, with a particular emphasis on the influence of drying conditions on the relations between the cell wall structure, dimensional stability and hygroscopicity of degraded archaeological wood. The choice of the particular drying methods was dictated by their final effect on wood appearance (dimensions). The results obtained clearly show that depending on the drying method applied, the resulting material differs significantly in structure, dimensions and sorption properties, despite the same degree of wood degradation. Air- and oven-drying resulted in the highest wood shrinkage, lower porosity, and a decreased number of free hydroxyls in the wood cell wall. The best wood dimensional stabilisation and the highest porosity were ensured by freeze- and supercritical drying. No correlations were found between wood structure and moisture behaviour. The outcome of the research may be useful for conservators who plan to provide the artefacts with proper storage conditions and effective conservation/reconservation.
Impact of Specific Bowel Symptoms on Quality of Life in Patients with Midgut Neuroendocrine Tumours
Authors: Ohlsson Håkan , Wahlberg Gideon , Malmström Marlene , Gustafsson Rita , Sundlöv Anna , Nordenström Erik , Almquist Martin
Published: May 2021

Introduction

Patients with midgut neuroendocrine tumours (NETs) suffer from decreased health‐related quality of life (HRQoL), in large part due to bowel symptoms. However, it is unknown which bowel symptoms affect HRQoL the most. An enhanced understanding of this is essential to better focus treatment on this aspect of the disease. This study aimed to determine which bowel symptoms affect HRQoL the most in patients with midgut NETs.

Methods

Consenting patients with midgut NET completed the Memorial Sloan Kettering Bowel Function Instrument and the HRQoL questionnaire (EORTC QLQ‐C30). The correlation between bowel symptoms and HRQoL was analysed using multiple linear regression, adjusting for age, Charlson Comorbidity Index score, presence of metastatic disease, chromogranin A, and BMI yielding ß‐coefficients with 95% confidence intervals.

Results

Totally, 119 patients with midgut NET completed the questionnaires and were included in the study. Loose stool and bowel frequency ≥ 3/day were the most common bowel symptoms, reported by 47% and 56% of patients, respectively. However, sensitivity to certain types of food and beverages, a feeling of incomplete emptying of the bowel, and soiling were the symptoms most strongly correlated with decreased HRQoL, especially within domains concerning role and social function, with ß‐coefficients for the strongest correlated symptoms of 15.0 and 14.6, respectively.

Discussion

While symptoms concerning stool consistency and frequency are common in patients with midgut NET, our study suggests that other, more socially stigmatising symptoms affect patients’ HRQoL more. Our findings could help caregivers understand patients’ perceptions of the disease and provide avenues for more directed therapies.
Deep neural networks for quantum circuit mapping
Authors: Acampora Giovanni , Schiattarella Roberto
Published: May 2021

Quantum computers have become reality thanks to the effort of some majors in developing innovative technologies that enable the usage of quantum effects in computation, so as to pave the way towards the design of efficient quantum algorithms to use in different applications domains, from finance and chemistry to artificial and computational intelligence. However, there are still some technological limitations that do not allow a correct design of quantum algorithms, compromising the achievement of the so-called quantum advantage. Specifically, a major limitation in the design of a quantum algorithm is related to its proper mapping to a specific quantum processor so that the underlying physical constraints are satisfied. This hard problem, known as circuit mapping, is a critical task to face in quantum world, and it needs to be efficiently addressed to allow quantum computers to work correctly and productively. In order to bridge above gap, this paper introduces a very first circuit mapping approach based on deep neural networks, which opens a completely new scenario in which the correct execution of quantum algorithms is supported by classical machine learning techniques. As shown in experimental section, the proposed approach speeds up current state-of-the-art mapping algorithms when used on 5-qubits IBM Q processors, maintaining suitable mapping accuracy.
Impacts of litter decay on organic leachate composition and reactivity
Authors: Hensgens Geert , Lechtenfeld Oliver J. , Guillemette François , Laudon Hjalmar , Berggren Martin
Published: May 2021

Litter decomposition produces labile and recalcitrant forms of dissolved organic matter (DOM) that significantly affect soil carbon (C) sequestration. Chemical analysis of this DOM can provide important knowledge for understanding soil DOM dynamics, but detailed molecular analyses on litter derived DOM are scarce. Here we use ultrahigh resolution mass spectrometry (FT-ICR MS) to characterize the molecular composition of DOM from fresh and progressively decomposed litter samples. We compared high reactive (HR) and low reactive (LR) litter sources with regard to changes in the chemistry and bioavailability of leachates throughout the early phase of litter decay. We show that litter reactivity is a driver of chemical changes in the leached DOM of litter species. Birch, alder and Vaccinium (i.e. HR) litter initially produced more DOM with a higher lability than that of spruce, pine and wood (i.e. LR) litter. Labile oxidized phenolic compounds were abundant in leachates produced during the initial HR litter decay stages, indicating litter lignin degradation. However, the similarity in chemistry between HR and LR leachates increased during the litter decay process as highly leachable structures in HR litter were depleted. In contrast, chemistry of leachates from LR litter changed little during the litter decay process. The oxygenated phenolic compounds from HR litter were driving the lability of HR leachates and the changes in relative abundance of molecules during DOM incubation. This appeared to result in the creation of stable aliphatic secondary microbial compounds. In LR leachates, lability was driven by labile aliphatic compounds, while more resistant phenolic compounds were associated with recalcitrance. These results show how DOM dynamics follow different paths depending on litter reactivity, which has important implications for soil biogeochemistry and C sequestration.
Optimal Incentives for Patent Challenges in the Pharmaceutical Industry
Authors: Böhme Enrico , Frank Jonas Severin , Kerber Wolfgang
Published: May 2021

In this paper, we show that a provision in antitrust law to allow patent settlements with a later market entry of generics than the date that is expected under patent litigation can increase consumer welfare. We introduce a policy parameter for determining the optimal additional period for collusion that would incentivize the challenging of weak patents and maximize consumer welfare. While in principle, later market entry leads to higher profits and lower consumer welfare, this can be more than compensated for if more patents are challenged as a result.
Numerical Design and Experimental Validation of a Plastic 3D-Printed Waveguide Antenna for Shallow Object Microwave Imaging
Authors: Bossi Luca , Falorni Pierluigi , Priori Saverio , Olmi Roberto , Capineri Lorenzo
Published: May 2021

Microwave imaging of shallow buried objects has been demonstrated with holographic radar for landmine detection, civil engineering and cultural heritage. A key component of this system is the antenna based on a truncated cylindrical waveguide with two feeds. This paper investigates for the first time a manufacturing technology based on the 3D printing of a volumetric cylindrical plastic antenna. The investigation of this manufacturing technology was motivated by the reduction in the antenna size and customization of the electromagnetic characteristics to the radio frequency electronics mounted on the robotic scanning system. The antenna that was designed using a simulator and filled with polylactic acid plastic material (relative dielectric permittivity Ɛr = 2.5) is compared to the metal antenna, both operating at around 2 GHz. The goal was to replicate the characteristics of the void core antenna to be able to provide the same quality/information of the microwave images of shallow buried objects. Finally, we compared the scan results of dielectric and metal targets both in the air and in natural soil. From the observation of some of the characteristics of the images, such as dynamics, morphology of the target, signal-to-noise ratio, and operating distance, we demonstrate that 3D printing for volumetric cylindrical waveguide antenna could be used to obtain compact and easily adaptable antennas for different applications in remote sensing.
Security Threat Analysis of the 5G ESSENCE Platform
Authors: Chochliouros Ioannis P. , Spiliopoulou Anastasia S. , Kostopoulos Alexandros , Kourtis Michail-Alexandros , Lazaridis Pavlos I. , Zaharis Zaharias D. , Prasad Neeli R.
Published: May 2021

The present paper discusses several security requirements coming from assessment of the use cases developed within the context of the original 5G-PPP “5G ESSENCE” project. Following to a concrete introduction to the project’s main innovative features and the description of all selected use cases coming directly from the vertical markets, we have separately assessed each one among them towards identifying security threats affecting the development of associated virtualised services within the broader 5G scope. Once our analysis has been performed, we propose options for potential service implementation, to ensure specific security requests.
Making the Umwelt Bubble of the Modern Synthesis Burst
Authors: Tønnessen Morten
Published: May 2021

Noble rightly emphasizes that some modern evolutionary biologists´ neglect of agency is consequential with regard to our understanding of the natural world and real-world ecological developments. I elaborate on biosemiotic ideas on semiotic agency and explain how organisms can change the environment by way of semiotic causation. I also comment on the human language’s role in human Umwelten, and how our linguistically mediated reality can be self-deceptive – as if we lived in a bubble of our own making. Finally, I indicate how we can make the Umwelt bubble of the Modern Synthesis burst.
Review of mechanical properties of and optimisation methods for continuous fibre-reinforced thermoplastic parts manufactured by fused deposition modelling
Authors: Handwerker Michael , Wellnitz Jörg , Marzbani Hormoz
Published: May 2021

A new way of manufacturing continuous fibre-reinforced plastics is the embedding of fibres in the filament of a 3D printer. This method could be used in manufacturing composite materials with a thermoplastic matrix containing glass, Kevlar and carbon fibres. This paper provides an overview of research on the mechanical and physical properties of these parts as well as optimisation approaches of additively manufactured thermoplastics. Furthermore, applicable testing and analysis methods and their corresponding standards are included. Several studies, which represent the current state of the art, are reviewed in detail for the analysis of the mechanical performance of different fibre reinforcements. In addition, an overview of different optimisation approaches is given. The ultimate tensile strength of Kevlar and glass fibre-reinforced parts are similar to those of common Aluminium alloys whereas the carbon fibre reinforced parts outperform their aluminium counterparts. Major performance limitations include a poor adhesion between layers as well as a high air void ratio.
Novel Radiographic Indexes for Elbow Stability Assessment: Part A—Cadaveric Validation
Authors: Luceri Francesco , Cucchi Davide , Rosagrata Enrico , Zaolino Carlo Eugenio , Viganò Marco , de Girolamo Laura , Zagarella Andrea , Catapano Michele , Gallazzi Mauro Battista , Arrigoni Paolo Angelo , Randelli Pietro Simone
Published: May 2021

Introduction

Elbow bony stability relies primarily on the high anatomic congruency between the humeral trochlea and the ulnar greater sigmoid notch. No practical tools are available to distinguish different morphotypes of the proximal ulna and herewith predict elbow stability. The aim of this study was to assess inter-observer reproducibility, evaluate diagnostic performance and determine responsiveness to change after simulated coronoid process fracture for three novel elbow radiographic indexes.

Methods

Ten fresh-frozen cadaver specimens of upper limbs from human donors were available for this study. Three primary indexes were defined, as well as two derived angles: Trochlear Depth Index (TDI); Posterior Coverage Index (PCI); Anterior Coverage Index (ACI); radiographic coverage angle (RCA); olecranon–diaphisary angle (ODA). Each index was first measured on standardized lateral radiographs and subsequently by direct measurement after open dissection. Finally, a type II coronoid fracture (Regan and Morrey classification) was created on each specimen and both radiographic and open measurements were repeated. All measurements were conducted by two orthopaedic surgeons and two dedicated musculoskeletal radiologists.

Results

All three indexes showed good or moderate inter-observer reliability and moderate accuracy and precision when compared to the gold standard (open measurement). A significant change between the radiographic TDI and ACI before and after simulated coronoid fracture was observed [TDI: decrease from 0.45 ± 0.03 to 0.39 ± 0.08 (p = 0.035); ACI: decrease from 1.90 ± 0.17 to 1.58 ± 0.21 (p = 0.001)]. As expected, no significant changes were documented for the PCI. Based on these data, a predictive model was generated, able to identify coronoid fractures with a sensitivity of 80% and a specificity of 100%.

Conclusion

New, simple and easily reproducible radiological indexes to describe the congruency of the greater sigmoid notch have been proposed. TDI and ACI change significantly after a simulated coronoid fracture, indicating a good responsiveness of these parameters to a pathological condition. Furthermore, combining TDI and ACI in a regression model equation allowed to identify simulated fractures with high sensitivity and specificity. The newly proposed indexes are, therefore, promising tools to improve diagnostic accuracy of coronoid fractures and show potential to enhance perioperative diagnostic also in cases of elbow instability and stiffness.

Level of evidence

Basic science study.

Clinical relevance

The newly proposed indexes are promising tools to improve diagnostic accuracy of coronoid fractures as well as to enhance perioperative diagnostic for elbow instability and stiffness.
Accounting for Multisectoral Dynamics in Supporting Equitable Adaptation Planning: A Case Study on the Rice Agriculture in the Vietnam Mekong Delta
Authors: Jafino Bramka Arga , Kwakkel Jan H. , Klijn Frans , Dung Nguyen Viet , van Delden Hedwig , Haasnoot Marjolijn , Sutanudjaja Edwin H.
Published: May 2021

The need for explicitly considering equity in climate change adaptation planning is increasingly being recognized. However, evaluations of adaptation often adopt an aggregated perspective, while disaggregation of results is important to learn about who benefits when and where. A typical example is adaptation of rice agriculture in the Vietnam Mekong Delta (VMD). Efforts focused on flood protection have mainly benefitted large‐scale farmers while harming small‐scale farmers. To investigate the distributional consequences of adaptation policies in the VMD, we assess both aggregate total output and equity indicators, as well as disaggregated impacts in terms of district‐level farming profitability. Doing so requires an adequate representation of the multisectoral dynamics between the human and biophysical systems which influence farming profitability. We develop a spatially explicit integrated assessment model that couples inundation, sedimentation, soil fertility and nutrient dynamics, and behavioral land‐use change and farming profitability calculation. We find that inter‐district inequality responds in a non‐linear way to climatic and socio‐economic changes and choices of adaptation policies. The patterns of who wins and who loses could change substantially when a different policy is implemented or if a slightly different uncertain future materializes. We also find that there is no simple ranking of alternative adaptation policies, so one should make trade‐offs based on agreed preferences. Accounting for equity implies exploring the distribution of outcomes over different groups over a range of uncertain futures. Only by accounting for multisectoral dynamics can planners anticipate the equity consequences of adaptation and prepare additional measures to aid the worse‐off actors.