bluuebunny/crossref_metadata_2025 huggingface dataset:
Temperature effect on the tensile properties of unplasticized polyvinyl chloride
Authors: Amorim Felipe C. , Souza Joao F. B. , da Costa Mattos Heraldo S. , Reis Joao M. L.
Published: February 2022

The present paper investigates the effect of temperature of unplasticized polyvinyl chloride (UPVC) under tension. UPVC specimens were tensile tested across a range of temperatures (from −20°C to 60°C). The UPVC, like other polymers, was strongly affected by temperature. Those below room temperature were more fragile but had greater tensile strength and stiffness. When room temperature is exceeded, the UPVC test specimens became softer, with lower strength and stiffness. Considering the results, an analytical expression to predict the mechanical behavior of UPVC in tensile tests at different temperatures—more specifically a description of the experimental tensile stress–strain curves by an algebraic equation is proposed. A reasonable approximation of the stress–strain curve was possible to obtain with a minimum of three tests performed at different temperatures. The analytical results were in good agreement with experimental ones.
Homotopy Transfer and Effective Field Theory II: Strings and Double Field Theory
Authors: Arvanitakis Alex S. , Hohm Olaf , Hull Chris , Lekeu Victor
Published: February 2022

We continue our study of effective field theory via homotopy transfer of ‐algebras, and apply it to tree‐level non‐Wilsonian effective actions of the kind discussed by Sen in which the modes integrated out are comparable in mass to the modes that are kept. We focus on the construction of effective actions for string states at fixed levels and in particular on the construction of weakly constrained double field theory. With these examples in mind, we discuss closed string theory on toroidal backgrounds and resolve some subtle issues involving vertex operators, including the proper form of cocycle factors and of the reflector state. This resolves outstanding issues concerning the construction of covariant closed string field theory on toroidal backgrounds. The weakly constrained double field theory is formally obtained from closed string field theory on a toroidal background by integrating out all but the ‘doubly massless’ states and homotopy transfer then gives a prescription for determining the theory's vertices and symmetries. We also discuss consistent truncation in the context of homotopy transfer.
A modeling‐based proposal for safe and efficacious reintroduction of bedaquiline after dose interruption: A population pharmacokinetics study
Authors: Keutzer Lina , Akhondipour Salehabad Yasamin , Davies Forsman Lina , Simonsson Ulrika S. H.
Published: February 2022

Bedaquiline (BDQ) is recommended for treatment of multidrug‐resistant tuberculosis (MDR‐TB) for the majority of patients. Given its long terminal half‐life and safety concerns, such as QTc‐prolongation, re‐introducing BDQ after multiple dose interruption is not intuitive and there are currently no existing guidelines. In this simulation‐based study, we investigated different loading dose strategies for BDQ re‐introduction, taking safety and efficacy into account. Multiple scenarios of time and length of interruption as well as BDQ re‐introduction, including no loading dose, 1‐ and 2‐week loading doses (200 mg and 400 mg once daily), were simulated from a previously published population pharmacokinetic (PK) model describing BDQ and its main metabolite M2 PK in patients with MDR‐TB. The efficacy target was defined as 95.0% of the average BDQ concentration without dose interruption during standard treatment. Because M2 is the main driver for QTc‐prolongation, the safety limit was set to be below the maximal average M2 metabolite concentration in a standard treatment. Simulations suggest that dose interruptions between treatment weeks 3 and 72 (interruption length: 1 to 6 weeks) require a 2‐week loading dose of 200 mg once daily in the typical patient. If treatment was interrupted for longer than 8 weeks, a 2‐week loading dose (400 mg once daily) was needed to reach the proposed efficacy target, slightly exceeding the safety limit. In conclusion, we here propose a strategy for BDQ re‐introduction providing guidance to clinicians for safe and efficacious BDQ dosing.
Improving the Met Office's Forecast Ocean Assimilation Model (FOAM) with the assimilation of satellite‐derived sea‐ice thickness data from CryoSat‐2 and SMOS in the Arctic
Authors: Mignac Davi , Martin Matthew , Fiedler Emma , Blockley Ed , Fournier Nicolas
Published: February 2022

Derived from two complementary satellites, CryoSat‐2 and Soil Moisture and Ocean Salinity (SMOS), sea ice thickness (SIT) data are assimilated into the Met Office's global ocean–sea ice forecasting system, FOAM, using a 3D‐Var assimilation scheme, NEMOVAR. CryoSat‐2 along‐track SITs, which are converted from freeboard measurements using the model snow depth, and a daily, gridded SMOS SIT product are used in the assimilation to constrain the Arctic sea ice thickness. When using only CryoSat‐2 assimilation, SIT forecast fields within the ice pack are greatly improved with respect to independent airborne measurements. However, the positive impacts of CryoSat‐2 assimilation in thick ice regions are counteracted by an SIT overestimation in areas of thin ice, due to biased freeboard measurements there. Adding the SMOS assimilation results in much thinner SITs in those regions, which performs better than the control when compared to SIT objective analyses and mooring measurements in the Beaufort and Barents Seas. Furthermore, SMOS assimilation enhances the short‐term predictive skill of the marginal sea‐ice concentration relative to the control. This is translated into a consistent retreat of the sea‐ice covered areas in the 5‐day forecasts during March 2017, which is in better agreement with independent ice edge products. This work successfully demonstrates improvements in FOAM sea ice when SIT observations from both CryoSat‐2 and SMOS are assimilated, representing an important step towards the operational implementation of SIT assimilation within Met Office forecasting systems.
The linkage between Agile project management and sustainable development: A theoretical and empirical view
Authors: Zakrzewska Małgorzata , Piwowar‐Sulej Katarzyna , Jarosz Szymon , Sagan Adam , Sołtysik Mariusz
Published: February 2022

The issue of project management methodologies has never be undertaken by academics in the context of their contribution to sustainability. There is the lack of understanding which Agile Project Management (APM) results and Agile value creation methods are in line with the assumptions of sustainability. The article fills this gap and presents the linkage between Agile project management and sustainability. The article presents both theoretical considerations as well as the results of empirical research that explains the relationship between APM and sustainability. As a result of multiple surveys, Guttman scales were developed, which showed the degree of Agile aspects' influence on sustainability, taking into account both the results of Agile implementation and the methods of value creation. Research revealed that improving the timeliness of deliveries, increase in productivity and improving the atmosphere in the organization as APM result is significant for sustainability. Value creation methods that most correspond with sustainability are design thinking and Agile rituals. The above provide certain practical and theoretical implications.
Two Imidazo[1,2‐a]pyridine Congeners Show Aggregation‐Induced Emission (AIE): Exploring AIE Potential for Sensor and Imaging Applications
Authors: Mala Ramanjaneyulu , Divya Dhakshinamurthy , Vijayan Priyadharshni , Narayanasamy Mathivanan , Thennarasu Sathiah
Published: February 2022

Density functional theoretical calculations predicted non‐coplanar twisted geometry for two new imidazo[1,2‐a]pyridine derivatives, Imp and ImBt. Analysis of single‐crystal of Imp asserted the non‐coplanar twisted geometry, which is implicated in aggregation induced emission (AIE) of small aromatic molecules. Universal quenching by water was observed in aqueous THF solutions of Imp and ImBt, but they showed AIE effect when the water content was more than 80 %. Non‐fluorescent solutions of Imp and ImBt in THF‐water (7 : 3 v/v) mixture turned fluorescent on addition of specific metal ions prompting their potential to be explored for turn‐on sensor applications. While ImBt showed AIE response to Cd2+, Hg2+ and Al3+, Imp displayed AIE effect only to Cd2+ ions, under identical conditions. Absence of interference from common metal ions (including Hg2+ and Al3+) led to selective formation of Imp‐CdCl2 (1 : 1) complex, which offered the limit of detection of Cd2+ to be 19.2 μM. The observed selectivity for Cd2+ permitted the use of Imp in the imaging of live Rhizoctonia oryze contaminated with Cd2+ ions.
Crystallographic and Computational Characterisation of the Potential PET Tracer 1,4,7‐Triazacyclononane‐1,4,7‐tri(methylenephosphonato)gallium(III)
Authors: Davey Patrick R. W. J. , Forsyth Craig M. , Paterson Brett M.
Published: February 2022

The macrocyclic chelator 1,4,7‐triazacyclononane‐1,4,7‐tri(methylenephosphonic acid) (H6NOTP) has shown significant promise for use in positron emission tomography with the positron‐emitting radionuclide 68Ga3+. We report the X‐ray crystal structure of the neutral complex 1,4,7‐triazacyclononane‐1,4,7‐tri(methylenephosphonato)gallium(III) ([Ga(H3NOTP)]), which crystallised in the centrosymmetric space group P21/n. The coordination geometry of the Ga3+ ion is distorted octahedral with three macrocyclic amine N donor atoms and three singly deprotonated phosphonato O donor atoms. Two discrete enantiomers, Δ(λλλ)‐SSS and Λ(δδδ)‐RRR, are present as a racemate within the unit cell. Intermolecular hydrogen bonds between phosphonic acid groups of adjacent complexes form a two‐dimensional sheet network. Density functional theory (DFT) calculations supported the observation of complexes with low electric field gradient values with slight but significant deviations from ideal octahedral geometry. The DFT calculations were also used to investigate the influence of intermolecular interactions and ligand protonation states on the coordination environment and surface charge distribution.
Lemon Juice: A Versatile Biocatalyst and Green Solvent in Organic Transformations
Authors: Shaik Baji Baba , Seboletswe Pule , Mohite Sachin Balaso , Katari Naresh Kumar , Bala Muhammad D. , Karpoormath Rajshekhar , Singh Parvesh
Published: February 2022

Green chemistry is the basis for fast‐growing, eco‐friendly, alternative sustainable technologies for the development of chemical products without the use or generation of hazardous catalysts. The role of naturally occurring fruit juice as a catalyst or solvent in organic synthesis has gained focused interest across the globe. Lemon juice‐mediated synthesis has been widely explored recently as a highly significant, selective solvent and biocatalyst in organic synthesis. This review presents recent developments on lemon‐juice mediated transformations and their application to synthesize molecules or building blocks of pharmaceutical interest. We believe this review article will be of interest to researchers both in academic and industrial settings focused on developing novel pharmacophores from a green chemistry principles perspective.
Statistical Optimization and Modeling Approach for Fenton‐like Discoloration of Methyl Orange using Green Zero‐valent Iron Nanoparticle Catalysts
Authors: Chowdhury Sujan , Al‐Mamun Abdullah , Zulfiqar Muhammad , Alam M. M. , Rahman Mohammed M.
Published: February 2022

Wastewater treatment is extremely beneficial to the environment by minimizing pollution. Water pollution caused by textile industries deteriorates ecosystems and threatens the environment. In this study, we fabricated nanoscale zerovalent iron nanoparticle (NZVI‐NPs) catalysts that act as Fenton‐like adsorbents, which remove methyl orange (MO) dye from wastewater much faster than microscale nanoparticles. The analysis of variance (ANOVA) led us to derive a quadratic model with R2=0.973. According to the central composite design in response surface methodology (CCD‐RSM) statistical optimization, 99.65 % of predicted decolorization was achieved with 1.0 g/L catalyst loading, pH initialization of 3.0, reaction temperature of 25 °C, and 22 mmol/L H2O2 concentration. By fitting a pseudo‐second‐order kinetic model, we calculated the rate constant of dye adsorption. The Langmuir isotherm demonstrated an excellent correlation between dye adsorption and catalyst with a maximum adsorption capacity (50.45 mg/g). The activation energy of the catalyst (62.26 kJ/mol) predicts a physical adsorption process. Newly developed catalysts are green efficient adsorbents suitable for significant dye removal from wastewater for the safety of aquatic life and human life. Moreover, these newly developed materials could be more suitable for the remediation of other harmful pollutants and the production of hydrogen, energy and water splitting applications.
Hybridization of Nanoclay with a Chromium‐Based Metal‐Organic Framework for Boosting Adsorption of Organic Dyes from Wastewater
Authors: Far Hossein Shahriyari , Hasanzadeh Mahdi , Najafi Mina , Rahimi Rahmatollah
Published: February 2022

We demonstrate enhanced dye adsorption capacity of nanoclay by decoration with chromium‐based MOF (MIL‐101) nanostructure. The Clay/Cr‐MOF composite exhibits a crystalline structure with high thermal stability. Moreover, it shows the superior specific surface area (4959 m2/g) and porosity which is beneficial for wastewater treatment. The developed Clay‐MOF composite exhibits superb adsorption capacity toward various organic dyes as compared with existing materials. The adsorption experiments revealed high adsorption capacity and selective dye removal efficiency of MOF‐modified nanoclay with reusability for multiple regeneration cycles. The adsorption kinetics was found to obey the pseudo‐second‐order kinetic model. These findings provide new insights into the application of such porous adsorbents for wastewater treatment applications.
Metal‐Free Boron‐Rich Borocarbonitride Catalysts for High‐Efficient Oxygen Reduction to Produce Hydrogen Peroxide†
Authors: Liu Zhiming , Gao Dazhi , Hu Lina , Liu Fang , Liu Hui , Li Ying , Zhang Jun , Xue Yanming , Tang Chengchun
Published: February 2022

Hydrogen peroxide (H2O2) is one of major chemical products in industrial production and daily life. The electrochemical method of two‐electron oxygen reduction reaction (ORR) to synthesize H2O2 is a promising method. Carbon‐based materials are considered to be ideal catalysts for H2O2 production by ORR because of its low price and good conductivity, but H2O2 selectivity of catalysts is still unsatisfactory due to the unreasonable electronic structure. Heteroatom doping is considered to be an effective method to adjust the electronic structure of electrocatalysts. Here, we report B, N co‐doped graphite named borocarbonitride (BCN) materials with different atomic content as significant ORR catalysts. The relationship between the electronic structure of BCN catalysts and H2O2 selectivity was discovered. Specially, the born‐rich BCN electrocatalyst with optimal doping amount of B and N not only exhibits excellent H2O2 selectivity of 71.7 % at the applied potential of 0.4 V in alkaline solution, but also shows good electrochemical stability. The excellent H2O2 selectivity of the BCN catalyst may be attributed to high content of B−C bonds and excellent ion mobility in electrolyte. This work not only provides a meaningful reference for designing the electronic structure of BCN catalysts to promote electrocatalytic H2O2 production, but also broadens the application of high efficient and stable metal‐free electrocatalysts in the field of two‐electron ORR.
Azolo[5,1‐c][1,2,4]triazines and Azoloazapurines: Synthesis, Antimicrobial activity and in silico Studies
Authors: Voinkov Egor K. , Drokin Roman A. , Fedotov Victor V. , Butorin Ilya I. , Savateev Konstantin V. , Lyapustin Daniil N. , Gazizov Denis A. , Gorbunov Evgeny B. , Slepukhin Pavel A. , Gerasimova Natalya A. , Evstigneeva Natalya P. , Zilberberg Natalya V. , Kungurov Nikolay V. , Ulomsky Evgeny N. , Rusinov Vladimir L.
Published: February 2022

The present work reports on the synthesis of series of azolo[5,1‐c][1,2,4]triazines and derivatives of azoloazapurines. The synthesized compounds were tested in vitro for antibacterial activity against N. gonorrhoeae and antimycotic activity against Trichophyton interdigitale, Epidermophyton floccosum, Microsporum canis and Candida albicans. It was found that 10 compounds of the series of 3‐nitroazolo[5,1‐c][1,2,4]triazine‐4‐amines 4 exhibit high antibacterial activity (MIC≤15 μg/ml), but do not exhibit antimycotic activity. For compounds active against N. gonorrhoeae, a biological target was predicted from the pharmacophore search method and homologous modeling was carried out for it. The results of molecular docking using the constructed model of dihydrofolate reductase have a good correlation with in vitro tests. Refined docking showed the similarity of the leading compounds positions in the protein active site. The formation of stable non‐covalent bonds of the nitro group with the amino acid residues Lys34/Lys55 makes a major contribution to the orienting effect of ligands.
Cu(II), Mn(II) and Zn(II) Complexes of Anthracene‐Affixed Carboxylate‐Rich Tridentate Ligand: Synthesis, Structure, Spectroscopic Investigation and Their DNA Binding Profile
Authors: Majumder Avishek , Haldar Shobhraj , Dutta Nityananda , Das Arpan , Bera Manindranath
Published: February 2022

Anthracene‐affixed carboxylate‐rich tridentate ligand containing three new mononuclear complexes, [Cu(acpa)(H2O)2]⋅H2O (1), [Mn(acpa)(H2O)2] (2) and [Zn(acpa)(H2O)2] (3) (H2acpa=3‐(anthracene‐9‐ylmethyl‐carboxymethyl‐amino)‐propionic acid), have been synthesized and characterized by various analytical and spectral methods. In methanol, complexes 1–3 have been prepared by carrying out reaction of the ligand H2acpa with stoichiometric amounts of CuSO4 ⋅ 5H2O, MnSO4⋅H2O and ZnSO4 ⋅ 7H2O respectively, in the presence of NaOH at ambient temperature. The X‐ray crystal structure analysis reveals that complex 1 consists of a distorted square pyramidal copper center, coordinated to one acpa2− ligand in a tridentate manner (N,O,O) and two exogenous water molecules. On the other hand, the molecular structures of complexes 2 and 3, optimized by DFT method indicate that their core arrangements around the metal centers are similar to that of 1. In solution, the coordination phenomena of Cu((II), Mn(II) and Zn(II) ions with the ligand H2acpa and the structural features of the complexes have been authenticated by UV‐Vis and fluorescence titration experiments. The composition of the MII/acpa2− complexes (M=Cu, Mn, Zn) in 1–3 has been observed to be 1 : 1, based on the UV‐Vis/fluorescence titration results which are further supported by X‐ray crystallography and DFT calculation. Complexes 1–3 are investigated for their binding affinity towards Calf Thymus (CT) DNA in solution at pH∼7.5 by UV‐Vis and fluorescence spectroscopic methods. From the electronic absorption spectral studies, it has been found that the DNA binding constants of 1–3 are (5.67±0.32)×104 M−1, (2.35±0.26)×104 M−1 and (2.49±0.33)×104 M−1, respectively, following the order 1>3>2. Measurements of viscosity of DNA in the absence and presence of the metal complexes suggest that all three complexes interact with DNA through partial intercalative mode.
Sequencing innovation rollout: Learning opportunity versus entry speed
Authors: Klingebiel Ronald , Joseph John , Machoba Valerie
Published: February 2022

Research summary

Our article examines the deliberate creation of learning opportunities in the global rollout of innovations. Some firms launch in only a subset of markets at first, with later launches being conditional on debut‐market performance. Such sequencing decreases the downside of potential innovation failure but increases the downside of potential competitive preemption. Consistent with this trade‐off, handset makers during the feature‐phone era sequence rollout more often when innovations are novel. Also consistent is that sequencing seems to respond to firms' past experience with failure and preemption, and that it begins in markets offering strong signals of success and failure—markets with competing innovations and sophisticated consumers, respectively. Our findings contribute to the understanding of entry strategy and opens avenues for researching intentional organizational experimentation.

Managerial summary

Firms can decide whether to launch innovations little by little or everywhere at once. Trial launches allow firms to test commercial viability and react to outcomes before rolling out elsewhere, but risks that competitors get their first. An immediate global launch, by contrast, reduces the scope for competitive preemption but increases the costs of potential failure. Our article uses data from the handset industry to highlight conditions that shape rollout decisions and examine the debut markets sought out for trial launches. Firms tend to trial novel innovations in particular, and their experience with prior misses as well as flops influences their preference. Trial launches often begin in markets with strong competition and discerning consumers, indicating an initial prioritization of learning over monetization. Opportunities for experimentation during market rollout thus ought to feature in strategic considerations of entry timing.
3D Bioprinting of Multifunctional Dynamic Nanocomposite Bioinks Incorporating Cu‐Doped Mesoporous Bioactive Glass Nanoparticles for Bone Tissue Engineering
Authors: Zhu Hui , Monavari Mahshid , Zheng Kai , Distler Thomas , Ouyang Liliang , Heid Susanne , Jin Zhaorui , He Jiankang , Li Dichen , Boccaccini Aldo R.
Published: February 2022

Bioprinting has seen significant progress in recent years for the fabrication of bionic tissues with high complexity. However, it remains challenging to develop cell‐laden bioinks exhibiting superior physiochemical properties and bio‐functionality. In this study, a multifunctional nanocomposite bioink is developed based on amine‐functionalized copper (Cu)‐doped mesoporous bioactive glass nanoparticles (ACuMBGNs) and a hydrogel formulation relying on dynamic covalent chemistry composed of alginate dialdehyde (oxidized alginate) and gelatin, with favorable rheological properties, improved shape fidelity, and structural stability for extrusion‐based bioprinting. The reversible dynamic microenvironment in combination with the impact of cell‐adhesive ligands introduced by aminated particles enables the rapid spreading (within 3 days) and high survival (>90%) of embedded human osteosarcoma cells and immortalized mouse bone marrow‐derived stroma cells. Osteogenic differentiation of primary mouse bone marrow stromal stem cells (BMSCs) and angiogenesis are promoted in the bioprinted alginate dialdehyde‐gelatin (ADA‐GEL or AG)‐ACuMBGN scaffolds without additional growth factors in vitro, which is likely due to ion stimulation from the incorporated nanoparticles and possibly due to cell mechanosensing in the dynamic matrix. In conclusion, it is envisioned that these nanocomposite bioinks can serve as promising platforms for bioprinting complex 3D matrix environments providing superior physiochemical and biological performance for bone tissue engineering.
Optimizing the Performance of a Dual‐Injection Gas‐Stirred Ladle Using Physical Modeling
Authors: González-Rivera Carlos , Ramirez-Argáez Marco A. , Amaro-Villeda Adrián , Trápaga-Martínez Gerardo , Jardón-Pérez Luis Enrique
Published: February 2022

Herein, the effects of the angle between nozzles, oil thickness, gas flow ratio, and gas flow rate on mixing time and open eye area in a physical model of a gas‐stirred ladle with dual plugs are studied. The effect of the variables under study is determined using a two‐level factorial design. Particle image velocimetry (PIV) is used to establish, through the analysis of flow patterns, the effect of the studied variables on the hydrodynamics of the system. Results suggest that operating conditions significantly change the flow structure and greatly influence the system's mixing time and open eye area behavior. The Pareto front of the optimized results on mixing time and open eye area is obtained through a multiobjective optimization using a genetic algorithm (NSGA‐II). The results are conclusive in that, for optimal performance, the ladle must be operated using an angle slightly higher than 90° between plugs, a differentiated flow ratio, high oil thickness, and a gas flow rate adjusted according to whether the preference is given to the protection of the bath or to the mixing process.
Laboratory experiments and dual‐domain modeling of infiltration dynamics in partially saturated fractured porous media
Authors: Rüdiger Florian , Dentz Marco , Nimmo John , Kordilla Jannes
Published: February 2022

Many studies have shown that fracture networks can provide rapid pathways for water infiltration and time‐dependent recharge in the vadose zone of consolidated fractured rock formations. To investigate the control of fracture networks and fracture–matrix interaction on preferential flow and infiltration dynamics, we constructed a simple network system consisting of m × 2 sandstone blocks placed in between two glass plates. Water was injected from a point source directly into the fracture system with a constant flow rate of 1.5 g min−1. We used a dual‐porosity non‐equilibrium model to model the discharge dynamics and the internal fracture–matrix mass exchange and observed strong deviations from the laboratory results when the original parameterization was used. This specifically concerns the matrix–fracture volume ratio κ and the fracture flow velocity v that require modifications in terms of their definition and underlying process description. Although the original model assumes a perfectly coupled fracture and matrix domain, in the experiments the discrete nature of the fracture network led to a much stronger dominance of the rapid flow domain and hence to a reduction of κ. The newly introduced parameter κ* includes additional effects and processes related to the time‐dependent evolution and smaller size of the fracture–matrix interface. Furthermore, experiments of varying total vertical system size reveal convergence toward a unique parameter set and the existence of a representative elementary volume (REV) for the chosen setup. Though it performs less well for very small systems below REV scale, the unique parameter set describes discharge dynamics in sufficiently large systems with high accuracy.
History and Development of Military Psychology
Authors: Mastroianni George R.
Published: February 2022

Psychology is widely thought to have emerged as a scientific discipline only quite recently: at the end of the nineteenth century. Psychological thinking had nevertheless been occurring for millennia, and such thinking formed a significant element of Greek philosophy in the centuries before the Common Era. The Greeks, no strangers to war, applied this thinking to military matters, such as learning, motivation, and the roles of environment and heredity in human development. From these beginnings, the systematic study of the unique considerations that arise when humans come together in military undertakings began. The industrialization of warfare that began in the nineteenth century added new questions and problems, problems which became more urgent just as the novel application of the methods of science to human psychology became institutionalized in universities in the decades before World War I. Today, military psychology is a vibrant and dynamic field that focuses on a core set of stable and enduring areas of study that include leadership, personnel selection, training, human factors, human performance, and clinical psychology. As military technology and the nature of warfare continue to evolve within the context of national and social institutions that are themselves constantly in flux, military psychology will adapt to encompass the new questions and problems brought by these changes.
Horizons and correlation functions in 2D Schwarzschild-de Sitter spacetime
Authors: Anderson Paul R. , Traschen Jennie
Published: February 2022

Abstract

Two-dimensional Schwarzschild-de Sitter is a convenient spacetime in which to study the effects of horizons on quantum fields since the spacetime contains two horizons, and the wave equation for a massless minimally coupled scalar field can be solved exactly. The two-point correlation function of a massless scalar is computed in the Unruh state. It is found that the field correlations grow linearly in terms of a particular time coordinate that is good in the future development of the past horizons, and that the rate of growth is equal to the sum of the black hole plus cosmological surface gravities. This time dependence results from additive contributions of each horizon component of the past Cauchy surface that is used to define the state. The state becomes the Bunch-Davies vacuum in the cosmological far field limit. The two point function for the field velocities is also analyzed and a peak is found when one point is between the black hole and cosmological horizons and one point is outside the future cosmological horizon.
The complementary value of intraoperative fluorescence imaging and Raman spectroscopy for cancer surgery: combining the incompatibles
Authors: Lauwerends L. J. , Abbasi H. , Bakker Schut T. C. , Van Driel P. B. A. A. , Hardillo J. A. U. , Santos I. P. , Barroso E. M. , Koljenović S. , Vahrmeijer A. L. , Baatenburg de Jong R. J. , Puppels G. J. , Keereweer S.
Published: February 2022

A clear margin is an important prognostic factor for most solid tumours treated by surgery. Intraoperative fluorescence imaging using exogenous tumour-specific fluorescent agents has shown particular benefit in improving complete resection of tumour tissue. However, signal processing for fluorescence imaging is complex, and fluorescence signal intensity does not always perfectly correlate with tumour location. Raman spectroscopy has the capacity to accurately differentiate between malignant and healthy tissue based on their molecular composition. In Raman spectroscopy, specificity is uniquely high, but signal intensity is weak and Raman measurements are mainly performed in a point-wise manner on microscopic tissue volumes, making whole-field assessment temporally unfeasible. In this review, we describe the state-of-the-art of both optical techniques, paying special attention to the combined intraoperative application of fluorescence imaging and Raman spectroscopy in current clinical research. We demonstrate how these techniques are complementary and address the technical challenges that have traditionally led them to be considered mutually exclusive for clinical implementation. Finally, we present a novel strategy that exploits the optimal characteristics of both modalities to facilitate resection with clear surgical margins.
International Survey of Medical Students Exposure to Relevant Global Surgery (ISOMERS): A Cross‐Sectional Study
Authors:   InciSioN Collaborative
Published: February 2022

Background

The principles of global surgery should be taught as a part of the core curriculum in medical schools. The need for medical students to be familiar with the topic is increasing in acceptance. There is, however, a paucity of data on how medical students are exposed to global surgery. This study aims to evaluate exposure of medical students to global surgery, awareness of the key messages of the Lancet Commission on Global Surgery, global surgery career aspirations and barriers to said aspirations.

Methods

ISOMERS was a multi‐centre, online, cross‐sectional survey of final year medical students globally. The questionnaire utilised a combination of Likert‐scale, multiple‐choice, and free text questions.

Results

In this study, 1593 final year medical students from 144 medical schools in 20 countries participated. The majority (n = 869/1496, 58.1%) believed global surgery to be relevant, despite 17.7% (n = 271/1535) having any exposure to global surgery. Most participants (n = 1187/1476, 80.4%) wanted additional resources on global surgery. Difficulty in providing appropriate care for patients living abroad (n = 854/1242, 68.8%) was the most common perceived barrier to a career in global surgery.

Conclusions

Participants believed global surgery was a relevant topic for medical students and wanted additional resources that they could access on global surgery. It is critical for medical students to become aware that global surgery is a field that aims to address inequity in surgical care not just internationally, but nationally and locally as well.
Plant litter composition and stable isotope signatures vary during decomposition in blue carbon ecosystems
Authors: Kelleway J. J. , Trevathan-Tackett S. M. , Baldock J. , Critchley L. P.
Published: February 2022

The ratio of isotopes of carbon (13C:12C or δ13C) and nitrogen (15N:14N or δ15N) are common indicators of the flow and storage of organic matter in coastal wetland research. Effective use of these indicators requires quantification and understanding of: (1) the variability of isotope signatures of potential organic matter source materials; and (2) the influence of organic matter decomposition on isotopic signatures. While it is well-established that organic matter characteristics change during the decomposition process, there has been little direct quantification of any concurrent shifts in isotope signatures for coastal detritus. In this study, we addressed this by quantifying: (1) shifts in sample composition using solid-state 13C Nuclear Magnetic Resonance (NMR) spectroscopy; and (2) shifts in δ13C and δ15N signatures of coastal plant tissues from field litterbag experiments. We observed significant shifts in 13C NMR spectra across the course of deployment for all four plant tissues assessed (leaves of mangrove Avicennia marina; branchlets of supratidal tree Casuarina glauca; leaf wrack and roots/rhizomes of the seagrass Zostera muelleri), driven largely by the preferential loss of labile constituents and concentration of more resistant macromolecules, such as lignin and leaf waxes. While there were shifts in isotope ratios for all species, these varied in direction and magnitude among species, tissue type and isotopes. This included δ13C enrichments of up to 3.1‰ and 2.4‰ in leaves of A. marina, and branchlets of C. glauca, respectively, but δ13C depletions of up to 4.0‰ for Z. muelleri. Shifts in δ15N varied among species and tissue types, with few clear temporal patterns. Partial least squares regression analyses showed that some tissue isotope signatures can be reliably predicted on the basis of sample composition (13C NMR spectra), however, multiple inter- and intra-species variations preclude a simple explanation of isotopic signature shifts on the basis of plant-material molecular shifts alone. Further, we cannot preclude the potential influence of microbe-associated organic matter on sample composition or isotopic signatures. Our findings emphasise the importance of considering decomposition effects on stable isotope signatures in blue carbon ecosystems. Isotope approaches will remain a valuable tool in coastal ecosystem research, but require robust experimental approaches (including appropriate use of decomposed end-members or fractionation correction factors; quantification of microbial organic matter) and quantification of decomposition dynamics for specific plant tissues and environmental settings.
Seaweed farming in Africa: current status and future potential
Authors: Msuya Flower E. , Bolton John , Pascal Fred , Narrain Koushul , Nyonje Betty , Cottier-Cook Elizabeth J.
Published: February 2022

Global demand for seaweed and its products has increased exponentially over the last 25 years. Equally, the continent of Africa and its offshore islands have considerable potential for seaweed production to contribute to world demand. Compared with China and the rest of Asia, Africa lags behind in seaweed production and utilisation. However, for red eucheumatoid seaweeds, Africa is the third-largest producer in the world, producing about 120,000 t (FW) annually. Details are provided for 13 African countries that are currently involved in seaweed farming and harvesting, commercially or experimentally, for export or domestic utilisation. Eucheuma spp. and Kappaphycus spp. in Tanzania represent 92% and in Madagascar 4.7% of continental production, and Ulva spp. and Gracilaria spp. in South Africa represent 1.5%. Over 2000 species of seaweed have been recorded in Africa, some of which are already successfully cultivated in other parts of the world. The environmental conditions across the continent range from warm, tropical waters to the cooler, nutrient-rich waters of the southwest, enabling the cultivation of seaweeds from the tropical, carrageenan-producing eucheumatoids to temperate kelp species. Seaweed aquaculture production in Africa, led predominantly by women, has improved the livelihoods of its coastal people. Challenges through disease and pest outbreaks, as a result of climate change, and the low prices paid to farmers are highlighted as major constraints on the development of this industry. Through scaling up and expanding current efforts in production and utilisation of seaweeds, Africa has the potential to join China and Southeast Asia as a global leader in producing, processing and consuming a wide variety of seaweeds.
Young Adult Adaptability to the Social Challenges of the COVID-19 Pandemic: The Protective Role of Friendships
Authors: Juvonen Jaana , Lessard Leah M. , Kline Naomi G. , Graham Sandra
Published: February 2022

The continuing COVID-19 pandemic enables assessment of the adaptability of young adults to non-normative stressors threatening their social-emotional wellbeing. Focusing specifically on a developmentally critical social challenge of restricted in-person contact, the goal of the current study was to examine the role of friendships in alleviating social-emotional problems. Data were collected via online surveys from an ethnically diverse sample (n = 1557) of 20 to 24-year-olds (62% cisgender female, 31% male, 7% gender diverse or gender questioning) in spring of 2021. Longitudinal data from an earlier time point involving an age-normative social challenge (transition out of high school) were used as a comparison. The comparisons between the transition from high school and the pandemic showed that whereas social anxiety and depressive symptoms increased, loneliness decreased. Participants also reported having slightly more friends and rated the overall quality of their friendships as somewhat higher. Regression analyses revealed that a greater number of friends over time and greater satisfaction with friend electronic communication during the pandemic were most robustly related to lower social and generalized anxiety as well as depressive symptoms, over and above earlier social-emotional wellbeing and a number of relevant correlates. Loneliness was protected by higher quality of friendships, greater contact with friends, as well as more frequent and satisfying electronic communication with friends. The results suggest that although young adults are facing emotional challenges during the continued pandemic, they are also able to adapt by keeping in touch with friends to decrease subjective sense of isolation. The findings have novel intervention implications to reduce loneliness.
Gender-sensitive sentiment analysis for estimating the emotional climate in online teacher education
Authors: Usart Mireia , Grimalt-Álvaro Carme , Iglesias-Estradé Adolf Maria
Published: February 2022

Teacher training takes place in distance education to a large extent. Within these contexts, trainers should make use of all the information available to adapt and refine their instructional methods during the training process. Sentiment analysis (SA) can give immediate feedback of the emotions expressed and help in the training process, although it has been used infrequently in educational settings, slow to assess, and bound to interpretative issues, such as gender bias. This research aimed to design and evaluate a SA gender-sensitive method as a proxy to characterize the emotional climate of teacher trainees in an online course. An explanatory case study with mixed methods was implemented among students of the Interuniversity Master of Educational Technologies (N = 48). Participants’ messages were analyzed and correlated with learning achievement and, along with a qualitative study of participants’ satisfaction with the Master’s degree, to validate the effectiveness of the method. Results show that sentiment expression cannot be used to exactly predict participants’ achievement, but it can guide trainers to foresee how participants will broadly act in a learning task and, in consequence, use SA results for tuning and improving the quality of the guidance during the course. Gender differences found in our study support gendered patterns related to the emotional climate, with female participants posting more negative messages than their counterparts. Last but not least, the design of well-adjusted teaching–learning sequences with appropriate scaffolding can contribute to building a positive climate in the online learning environment.
Agroforestry and reforestation with the Gold Standard-Decision Analysis of a voluntary carbon offset label
Authors: Netter Leonie , Luedeling Eike , Whitney Cory
Published: February 2022

Voluntary standards can help to ensure the quality of projects eligible for carbon offsetting, i.e., selling carbon certificates. However, in deciding on whether to adopt such standards, the managers of carbon offset projects are faced with uncertainty regarding the costs and risks involved. Decision Analysis provides a helpful set of tools that can support such decisions by forecasting outcomes under different scenarios. We applied Decision Analysis methods to generate models for the decisions to certify two projects in Costa Rica with the voluntary carbon offset label “The Gold Standard”. We evaluated certifying an additional site of a partially certified reforestation project, as well as the initial certification of an agroforestry project.

We calibrated and interviewed decision-makers and stakeholders of the certification projects to identify important parameters and translate these into a decision model. We ran the final decision model as a Monte Carlo simulation to project plausible ranges of decision outcomes, expressed as Net Present Values and annual cash flows. We identified critical uncertainties and research priorities by using the Expected Value of Perfect Information. The results indicate that certification of the two projects would result in a positive Net Present Value. The partially low return on investment of the certification, however, shows the need for projects to undergo thorough evaluation and generate customized strategies before participating in a voluntary carbon offset scheme. The Decision Analysis approaches we describe can help to improve the process of decision making under uncertainty and should be widely adopted for evaluating the potential impacts of certification.
Convergence rates of RLT and Lasserre-type hierarchies for the generalized moment problem over the simplex and the sphere
Authors: Kirschner Felix , de Klerk Etienne
Published: February 2022

We consider the generalized moment problem (GMP) over the simplex and the sphere. This is a rich setting and it contains NP-hard problems as special cases, like constructing optimal cubature schemes and rational optimization. Using the reformulation-linearization technique (RLT) and Lasserre-type hierarchies, relaxations of the problem are introduced and analyzed. For our analysis we assume throughout the existence of a dual optimal solution as well as strong duality. For the GMP over the simplex we prove a convergence rate of O(1/r) for a linear programming, RLT-type hierarchy, where r is the level of the hierarchy, using a quantitative version of Pólya’s Positivstellensatz. As an extension of a recent result by Fang and Fawzi (Math Program, 2020. https://doi.org/10.1007/s10107-020-01537-7) we prove the Lasserre hierarchy of the GMP (Lasserre in Math Program 112(1):65–92, 2008. https://doi.org/10.1007/s10107-006-0085-1) over the sphere has a convergence rate of $$O(1/r^2)$$

O
(
1
/

r
2

)

. Moreover, we show the introduced linear RLT-relaxation is a generalization of a hierarchy for minimizing forms of degree d over the simplex, introduced by De Klerk et al. (J Theor Comput Sci 361(2–3):210–225, 2006).
Desiderata for Rational, Non-doxastic Faith
Authors: Palmqvist Carl-Johan
Published: February 2022

According to an increasingly popular view known as non-doxasticism, religious faith need not include belief, but only some cognitively weaker attitude. This view comes with great promises, as it offers a way for the agnostic to partake in religion. My concern is how such a non-doxastic faith might be understood as a rational attitude. I offer three desiderata for any account of rational, non-doxastic faith. These desiderata are based on general considerations regarding epistemic rationality and on major themes from current literature on the closely related notions of trust and hope. The first desideratum states that faith must be able to meet the demands of reason. The second requires, perhaps surprisingly, that faith should not imply trust. The third requires that faith should imply hope while excluding despair. I show how several prominent accounts of non-doxastic faith, by Lara Buchak, Daniel Howard-Snyder and Daniel McKaughan, all fail to meet at least one of these desiderata. I also suggest that the desiderata should make us prefer a reconstructive methodology.
Literature review and proposal of best practice for ophthalmologists: monitoring of patients following intravitreal brolucizumab therapy
Authors: Kilmartin Dara J.
Published: February 2022

Brolucizumab is a novel humanised, single-chain, variable fragment inhibitor of Vascular Endothelial Growth Factor-A for the treatment of neurovascular age-related macular degeneration. Brolucizumab gained US Food and Drug Administration and European Medicines Agency approval following the Phase III HAWK (NCT02307682) and HARRIER (NCT02434328) trials which compared brolucizumab with aflibercept, presenting a tolerable safety and favourable efficacy profile. The mean change (least squares [LS] mean ± standard error) in best-corrected visual acuity letters from baseline to week 96 in the HAWK trial was 5.9 ± 0.78 for brolucizumab (6 mg) versus 5.3 ± 0.78 for aflibercept, and in the HARRIER trial, 6.1 ± 0.73 (6 mg) for brolucizumab (6 mg) and 6.6 ± 0.73 for aflibercept. Within both trials, greater reductions were noted in the central subfield thickness from baseline to week 96 in the brolucizumab (6 mg) groups versus the aflibercept group. Subsequent post-marketing reports detailed intraocular inflammation (IOI) after brolucizumab treatment and in response an independent safety review committee conducted a post hoc data review. While comparable, the rate of brolucizumab-associated IOI was higher in the post hoc analysis than the trials (4.6% and 4.4%, respectively). Findings from trials and real-world data indicate there may be pre-defining risk factors that predispose patients to IOI following brolucizumab treatment. With a thorough understanding of IOI classification and best practice management, ophthalmologists can use brolucizumab confidently and, should a case arise, they should act quickly to prevent vision loss. Herein, we provide information and guidance to support clinical decision-making related to brolucizumab use.