bluuebunny/crossref_metadata_2025 huggingface dataset:
Randomized, placebo‐controlled, phase 3 study of perifosine combined with bortezomib and dexamethasone in patients with relapsed, refractory multiple myeloma previously treated with bortezomib
Authors: Richardson Paul G. , Nagler Arnon , Ben‐Yehuda Dina , Badros Ashraf , Hari Parameswaran N. , Hajek Roman , Spicka Ivan , Kaya Hakan , LeBlanc Richard , Yoon Sung‐Soo , Kim Kihyun , Martinez‐Lopez Joaquin , Mittelman Moshe , Shpilberg Ofer , Blake Paul , Hideshima Teru , Colson Kathleen , Laubach Jacob P. , Ghobrial Irene M. , Leiba Merav , Gatt Moshe E. , Sportelli Peter , Chen Michael , Anderson Kenneth C.
Published: April 2020

Perifosine, an investigational, oral, synthetic alkylphospholipid, inhibits signal transduction pathways of relevance in multiple myeloma (MM) including PI3K/Akt. Perifosine demonstrated anti‐MM activity in preclinical studies and encouraging early‐phase clinical activity in combination with bortezomib. A randomized, double‐blind, placebo‐controlled phase 3 study was conducted to evaluate addition of perifosine to bortezomib‐dexamethasone in MM patients with one to four prior therapies who had relapsed following previous bortezomib‐based therapy. The primary endpoint was progression‐free survival (PFS). The study was discontinued at planned interim analysis, with 135 patients enrolled. Median PFS was 22.7 weeks (95% confidence interval 16·0–45·4) in the perifosine arm and 39.0 weeks (18.3–50.1) in the placebo arm (hazard ratio 1.269 [0.817–1.969]; P = .287); overall response rates were 20% and 27%, respectively. Conversely, median overall survival (OS) was 141.9 weeks and 83.3 weeks (hazard ratio 0.734 [0.380–1.419]; P = .356). Overall, 61% and 55% of patients in the perifosine and placebo arms reported grade 3/4 adverse events, including thrombocytopenia (26% vs 14%), anemia (7% vs 8%), hyponatremia (6% vs 8%), and pneumonia (9% vs 3%). These findings demonstrate no PFS benefit from the addition of perifosine to bortezomib‐dexamethasone in this study of relapsed/refractory MM, but comparable safety and OS.
Examining the Association Between Racial Identity Attitudes and Coping With Racism‐Related Stress
Authors: Lewis Jioni A. , Cameron Rebecca P. , Kim‐Ju Greg M. , Meyers Lawrence S.
Published: April 2020

The authors examined the association between racial identity attitudes and coping with racism‐related stress among Asian, Black, and Latinx college students (N = 195). Results of the canonical correlation analysis indicated that higher scores on a combination of all racial identity attitudes were significantly associated with greater active coping for Black and Latinx students. Among Asian students, the authors found that higher scores on conformity, dissonance, and immersion‐emersion racial identity attitudes were significantly associated with greater avoidant coping.

Los autores examinaron la asociación entre las actitudes de identidad racial y el afrontamiento del estrés relacionado con el racismo en estudiantes universitarios asiáticos, negros y latinxs (N = 195). Los resultados del análisis de correlación canónica indicaron que unos valores más altos en la combinación de todas las actitudes de identidad racial estaban asociados significativamente a un mayor afrontamiento activo en estudiantes negros y latinxs. En estudiantes asiático‐americanos, los autores hallaron que unos valores más altos en las actitudes de identidad racial de conformidad, disonancia e inmersión/emersión estaban asociados significativamente a un mayor afrontamiento evasivo.
Fretting corrosion of Si3N4 vs CoCrMo femoral heads on Ti‐6Al‐V trunnions
Authors: Khullar Piyush , Zhu Dongkai , Gilbert Jeremy L.
Published: April 2020

Fretting corrosion at the head‐neck taper junction was compared between silicon nitride (Si3N4) and commercially available cobalt chrome (CoCrMo) femoral heads on titanium (Ti‐6Al‐4V) trunnions. An electrochemical setup was used to capture the fretting currents (characterized by oxide abrasion and repassivation) during cyclic loading. Onset load, pull‐off force (disassembly load), short term and long term (1 million cycles) fretting currents were used to compare the fretting corrosion performance between the test group (Si3N4/Ti‐6Al‐4V) and the control group (CoCrMo/Ti‐6Al‐4V). Incremental cyclic fretting corrosion tests showed that the Si3N4/Ti‐6Al‐4V combination had statistically lower (P < .05) average fretting current of 0.189 µA (SD = 0.114 µA) compared to 0.685 µA (SD = 0.630 µA) for CoCrMo/Ti‐6Al‐4V for cyclic load of 3200 N. Similarly, for the one million cycle fretting corrosion tests, the Si3N4/Ti‐6Al‐4V couples had statistically lower (P < .05) average current (0.048 µA, SD = 0.025 µA) vs CoCrMo/Ti‐6Al‐4V couples (0.366 µA, SD = 0.143 µA). The Si3N4 heads also had higher onset loads (P < .05) for fretting (vs CoCrMo, 2200 N vs 1740 N) indicating a difference in surface contact mechanics between the two groups. Scanning electron microscopy with energy dispersive spectroscopy confirmed material transfer from the trunnions to the heads for both groups tested, and from head to trunnion for the CoCrMo heads. Minimal Si3N4 transfer was noted. The electrochemical, mechanical, and microscopic inspection data supported the hypothesis that Si3N4/Ti‐6Al‐4Vcombination had better fretting corrosion performance compared to CoCrMo/Ti‐6Al‐4V.
Linear calibrations in chromatography: The incorrect use of ordinary least squares for determinations at low levels, and the need to redefine the limit of quantification with this regression model
Authors: Sanchez Juan M.
Published: April 2020

Ordinary least squares is widely applied as the standard regression method for analytical calibrations, and it is usually accepted that this regression method can be used for quantification starting at the limit of quantification. However, it requires calibration being homoscedastic and this is not common. Different calibrations have been evaluated to assess whether ordinary least squares is adequate to quantify estimates at low levels. All calibrations evaluated were linear and heteroscedastic. Despite acceptable values for precision at limit of quantification levels were obtained, ordinary least squares fitting resulted in significant and unacceptable bias at low levels. When weighted least squares regression was applied, bias at low levels was solved and accurate estimates were obtained. With heteroscedastic calibrations, limit values determined by conventional methods are only appropriate if weighted least squares are used. A “practical limit of quantification” can be determined with ordinary least squares in heteroscedastic calibrations, which should be fixed at a minimum of 20 times the value calculated with conventional methods. Biases obtained above this “practical limit” were acceptable applying ordinary least squares and no significant differences were obtained between the estimates measured using weighted and ordinary least squares when analyzing real‐world samples.
Enhancing the selectivity of liquid chromatography–mass spectrometry by using trilinear decomposition on LC‐MS data: An application to three‐way calibration of coeluting analytes in human plasma
Authors: Yan Xiu‐Fang , Liang Yan‐Mei , Zhou Bo , Bin Jun , Kang Chao
Published: April 2020

The high selectivities of liquid chromatography and mass spectrometry make liquid chromatography–mass spectrometry one of the most popular tools for quantitative analysis in complex chemical, biological, and environmental systems, while the potential mathematical selectivity of liquid chromatography–mass spectrometry is rarely investigated. This work discussed the mathematical selectivity of liquid chromatography–mass spectrometry by three‐way calibration based on the trilinear model, with an application to quantitative analysis of coeluting aromatic amino acids in human plasma. By the trilinear decomposition of the constructed liquid chromatography–mass spectrometry‐sample trilinear model and individual regression of the decomposed relative intensity versus concentration, the proposed three‐way calibration method successfully achieved quantitative analysis of coeluting aromatic amino acids in human plasma, even in the presence of uncalibrated interferent(s) and a varying background. This analytical method can ease the requirements for sample preparation and complete chromatographic separation of components, reduce the use of organic solvents, decrease the time of chromatographic separation, and increase the peak capacity of liquid chromatography–mass spectrometry. As a “green analytical method”, the liquid chromatography–mass spectrometry three‐way calibration method can provide a promising tool for direct and fast quantitative analysis in complex systems containing uncalibrated spectral interferents, especially for the situation where the coelution problem is difficult to overcome.
The wisdom of ecosystems: A transactive memory theory of knowledge management in entrepreneurial ecosystems
Authors: Roundy Philip T.
Published: April 2020

The contextual turn in entrepreneurship research has shifted scholars' attention to the place‐based forces that shape entrepreneurship in vibrant entrepreneurial ecosystems, such as Silicon Valley, Stockholm, and Bangalore. Studies find that an important component of ecosystems is the knowledge they contain about the entrepreneurship process. However, the critical questions of how entrepreneurs overcome challenges associated with acquiring tacit knowledge, how entrepreneurs leverage their ecosystems to organize knowledge, and what factors influence an ecosystem's ability to serve as a knowledge repository remain unexamined. To formulate a theory explaining how entrepreneurs use their ecosystems to facilitate knowledge management and organizational learning, insights from group cognition are adapted to introduce the concept of entrepreneurial ecosystem transactive memory. It is theorized that ecosystem‐level characteristics, including diversity, coherence, connectivity, prosociality, and interdependence, influence an ecosystem's transactive memory structure and processes. By examining the linkages between ecosystem characteristics and transactive memory, a more nuanced understanding of the cognitive dynamics of entrepreneurial ecosystems is provided. The theoretical model charts a path for interdisciplinary research on knowledge management in entrepreneurial ecosystems and generates implications for practitioners.
The Shape of Things to Come: In‐Hospital Three‐Dimensional Printing for Mandibular Reconstruction Using Fibula Free Flap
Authors: Zavattero Emanuele , Fasolis Massimo , Novaresio Andrea , Gerbino Giovanni , Borbon Claudia , Ramieri Guglielmo
Published: April 2020

Objectives/Hypothesis

The aim of this study was to explore whether the production of in‐hospital, low‐cost surgical cutting guides would be possible and to assess different cutting guide shapes to facilitate the surgery and the application with instruments.

Study Design

Cohort study.

Methods

Using free computer‐aided design software, surgical cutting guides for the mandible and fibula were designed and used to perform virtual segmental osteotomies and fibula transplants in seven patients.

Results

Fourteen virtual osteotomies were performed using the free software and the proposed workflow. Thirteen guides were then printed to transfer the virtual planning information to the operating room.

Conclusions

Virtual planning and the three‐dimensional (3D) printing of guides for mandibular reconstruction is reliable with the aid of an in‐hospital 3D laboratory. We also demonstrated that different guides with different shapes could be produced with benefits during surgery.

Level of Evidence

4 Laryngoscope, 2020
Enhanced 2 µm Mid‐Infrared Laser Output from Tm3+‐Activated Glass Ceramic Microcavities
Authors: Kang Shiliang , Ouyang Tianchang , Yang Dandan , Pan Qiwen , Qiu Jianrong , Dong Guoping
Published: April 2020

Transparent glass ceramics (GCs) consisting of an homogeneous glass phase and a well‐dispersed crystal phase are considered as ideal optical gain materials potentially applied in optoelectronic devices due to the combination of facile processability of glass and the intense crystal field of nanocrystals. Here, a heat‐induced nanocrystal‐in‐glass method is employed to integrate the active ions Tm3+ into Bi2Te4O11 nanocrystals with an intense crystal field to realize an enhanced microlaser output. This strategy endows the efficient tellurate GC microcavity laser operating at ≈2 µm. Compared with the laser properties of as‐prepared glass microcavities, the pump threshold (260 µW) is as low as less than a quarter and the slope efficiency (0.0296%) is 5.5 times higher. Furthermore, by carefully engineering the heat treatment temperature and duration, the crystal size and distribution can be precisely controlled. Thus, the Rayleigh scattering loss that is detrimental to quality (Q) factor is effectively suppressed and the GC microcavities with high Q factors up to 105 are successfully obtained. This work provides useful insight on the development of optical functional materials and expands the practical applications of GC microcavities in various optoelectronic fields.
Charge‐Transfer‐Complexed Conjugated Microporous Polymers (CT‐CMPs)
Authors: Veldhuizen Hugo , van den Elzen Luc , Mahon Tadhg , Abellon Ruben , Nagai Atsushi
Published: April 2020

A new concept of the formation of charge transfer (CT) complexes between an intrinsically electron‐donating conjugated microporous polymer and a small molecule acceptor is reported. Spirobifluorene‐based mesoporous organic polymers with high porosity and Brunauer–Emmett–Teller surface area are synthesized by the Suzuki‐coupling reaction of spirobifluorene and pyrene monomers. The simple doping of the synthesized mesoporous, electron‐rich, conjugated polymer with 7,7,8,8‐tetracyanoquinodimethane as an acceptor leads to efficient CT complexation in the electron‐donating mesoporous spaces. This results in a high‐speed synthesis (within 5 s), thermally stable compound (up to about 200 °C), and good control of the concentration of donor–acceptor pairs in the CT complex.
Ring–Ring Equilibration in Solid, Even‐Numbered Cyclic Poly(l‐lactide)s and their Stereocomplexes
Authors: Weidner Steffen M. , Meyer Andreas , Kricheldorf Hans R.
Published: April 2020

Even‐numbered cyclic poly(d‐lactide) and poly(l‐lactide) are prepared by ring‐expansion polymerization. The cyclic pol(l‐lactide) is annealed either at 120 or at 160 °C for several days. The progress of transesterification in the solid state is monitored by the formation of odd‐numbered cycles via matrix‐assisted laser desorption/ionization‐time of flight mass spectrometry. The changes of the crystallinity are monitored by differential scanning calorimetry, wide‐ and small‐angle x‐ray scattering (WAXS and SAXS) measurements. Despite total even‐odd equilibration at 160 °C, the crystallinity of poly(l‐lactide) is not reduced. Furthermore, the crystallinity of the stereocomplexes of both cyclic polylactides do not decrease or vanish, as expected, when a blocky or random stereosequence is formed by transesterification. This conclusion is confirmed by 13C NMR spectroscopy. These measurements demonstrate that transesterification is a ring–ring equilibration involving the loops on the surfaces of the lamellar crystallites thereby improving crystallinity and 3D packing of crystallites without significant broadening of the molecular weight distribution.
13C solid‐state NMR complemented by ATR‐FTIR and micro‐DSC to study modern collagen‐based material and historical leather
Authors: Proietti Noemi , Di Tullio Valeria , Carsote Cristina , Badea Elena
Published: April 2020

Ancient vegetable tanned leathers and parchments are very complex materials in which both different manufacturing and deterioration processes make their study and chemical characterisation difficult. In this research, solid‐state nuclear magnetic resonance (NMR) spectroscopy was applied to identify different tannin families (condensed and hydrolysable) in historical leather objects such as bookbindings, wall upholsters, footwear and accessories, and military apparel. Furthermore, leather deterioration with special focus on collagen gelatinisation was investigated. A comparison with Fourier transform infrared (FTIR) spectroscopy and micro‐differential scanning calorimetry (micro‐DSC) was also performed to support the 13C CP‐MAS NMR findings and to point out the advantages and limitations of solid‐state NMR in analysing historical and archaeological leathers. A wide database of NMR and FTIR spectra of commercial tannins compounds was also collected in order to characterise historical and archaeological leathers.
Efficacy of electrical stimulation of denervated muscle: A multicenter, double‐blind, randomized clinical trial
Authors: Piccinini Giulia , Cuccagna Cristina , Caliandro Pietro , Coraci Daniele , Germanotta Marco , Pecchioli Cristiano , Padua Luca
Published: April 2020

Background

This was a multicenter, double‐blind, randomized clinical trial to investigate the efficacy of electrical stimulation of denervated muscle (ESDM) on recovery of patients with peripheral nerve injuries.

Methods

We enrolled 38 patients with traumatic peripheral nerve injuries with axonal damage and clinical impairment of two muscles, who were randomly treated with real or sham electrical stimulation (ES). Clinical and neurophysiological examinations were performed before treatment, at the end of treatment, and 3 mo posttreatment, by the same physician who was blinded to the ES allocation.

Results

All patients improved but there was no significant beneficial effect of ESDM compared with sham treatment.

Conclusions

This study failed to demonstrate the efficacy of ESDM for peripheral nerve injuries. However, given the large number of variables related to ES and the heterogeneity in disease etiologies and clinical manifestations, future studies on homogeneous populations using different stimulation protocols may be useful.
Assessing the (eco)macroeconomic performance index of India: A data envelopment analysis approach
Authors: Mohanty Ranjan Kumar , Sahoo Biresh K. , Chaudhury Pradipta K.
Published: April 2020

The prime objective of this article is to construct a robust macroeconomic performance (MEP) index of the Indian economy using the data envelopment analysis (DEA) approach. Seven major macro indicators, namely, economic growth, employment rate, terms of trade, inflation rate, fiscal deficit, pollution, and climate change are used to compute MEP and Eco‐MEP indices of the Indian economy from 1980–1981 to 2018–2019. Overall, both the MEP and Eco‐MEP index scores have quite similar best performing years worst performing years, and have also captured the major events that affected adversely the Indian economy during the past decades. The trend in the overall performance of the Indian economy was better in the 1980s and the 1990s but has deteriorated since 2000. The autoregressive distributed lag bounds testing approaches to cointegration methods are used to test the robustness/utility of these indices. The estimated results show that MEP and Eco‐MEP have a positive impact on private investment, foreign investment inflows, foreign direct investment, and a negative effect on the current account deficit. Hence, the suggested composite MEP index is stable, robust and truly captures the economic performance of India. The constructed MEP composite index may be used by foreign investors, rating agencies, private investors, and policymakers for their planning and decision‐making processes.
Mobility Assessment under Dual Task Conditions in Women With Fibromyalgia: A Test‐Retest Reliability Study
Authors: Murillo‐Garcia Alvaro , Villafaina Santos , Leon‐Llamas Juan Luis , Sánchez‐Gómez Jesús , Domínguez‐Muñoz Francisco Javier , Collado‐Mateo Daniel , Gusi Narcis
Published: April 2020

Objective

To assess the test‐retest reliability of the 10‐step stair ascent test, Timed Up and Go (TUG) test, and 10‐meter walking test under dual‐task conditions in patients with fibromyalgia.

Design

Test‐retest reliability.

Settings

Local fibromyalgia association and university facilities.

Participants

Thirty‐eight women with fibromyalgia.

Interventions

Not applicable.

Main Outcome Measures

Fear of falling and the number of falls in the last year were measured using a visual analogue scale. The 10‐step stair ascent test, TUG test, and 10‐meter walking test were conducted under single‐ and dual‐task conditions. The order between single‐ and dual‐task condition was randomized in both test and retest. Retest measurement was assessed the week following the test.

Results

The reliability of the performance on the 10‐step stair ascent test under dual and single conditions ranged between good (>0.75 to < 0.9) and excellent (≥0.9), but there were significant differences between test and retest. The reliability of the TUG is between good (≥0.75 to < 0.9) and excellent (≥0.9) under the dual‐task condition as well as moderate (≥0.5 to <0.75) and excellent (≥0.9) under the single‐task condition. The reliability of the 10‐meter walking dual‐task test is between moderate (≥0.5 to <0.75) and good (≥0.75 to < 0.9) under dual‐ and single‐task condition, respectively.

Conclusions

The TUG and 10‐meter walking tests are reliable for assessing mobility under the dual‐task condition in women with fibromyalgia. The performance on the TUG, 10‐step stair ascent, and 10‐meter walking test under single‐ and dual‐task conditions was significantly related to fear of falling. These results may help healthcare professionals and researchers to interpret the effect of interventions in women with fibromyalgia.
Development and validation of an algorithm of diagnostic and procedural codes for the identification of children hospitalized with a tracheostomy in Ontario, Canada
Authors: McKelvie Brianna , Pianosi Kiersten , Chan Jason , Tsampalieros Anne , Benchimol Eric I. , Macdonald Kristian I. , Strychowsky Julie , Vaccani Jean‐Philippe , McNally James D.
Published: April 2020

Background

The requirement for a tracheostomy in children is associated with significant morbidity, mortality, and healthcare utilization. Easy identification of children with tracheostomies would facilitate important research on this population and provide quality improvement initiatives.

Aim

The purpose of this study is to determine whether an algorithm of diagnostic and procedural codes can accurately identify children hospitalized with a tracheostomy using routinely collected health data.

Methods

Chart reviews were performed at the Children's Hospital of Eastern Ontario (CHEO) and the London Health Sciences Center (LHSC) to establish a true positive cohort of pediatric patients with tracheostomies admitted between 2008 and 2016. A multidisciplinary team developed algorithms of diagnostic and procedural codes contained within the Canadian Institute for Health Information Discharge Abstract Database. Algorithms were tested and refined against the true‐positive and true‐negative cohort. The accuracy of the diagnostic codes related to tracheostomy complications was also evaluated.

Results

A chart review identified 158 unique children with tracheostomies (77 at CHEO, 81 at LHSC) with 901 individual admissions (401 at CHEO, 507 at LHSC). The best algorithms for identifying children with a tracheostomy had a sensitivity and specificity of more than 99%, a positive predictive value (PPV) of 94.0% and negative predictive value (NPV) of 100%. The algorithm for the identification of tracheostomy‐related complications had a sensitivity of 76.7%, a specificity of 65%, PPV of 52.3%, and an NPV of 84.7%.

Conclusions

This study provides an algorithm for the accurate identification of children hospitalized in Canada with a tracheostomy, facilitating population‐level epidemiological research and quality improvement initiatives.
p‐Methoxyphenol: A potent and effective scavenger for solid‐phase peptide synthesis
Authors: Samacá Jhoan , Velandia‐Bautista Erika , Tabares Luisa , Escamilla Luis , Vanegas Magnolia , Patarroyo Manuel‐E.
Published: April 2020

During the final step of t‐Boc/Bzl, solid‐phase peptide synthesis (SPPS)‐protecting groups from amino acids (aa) side chains must be removed from the target peptides during cleavage from the solid support. These reaction steps involve hydrolysis with hydrogen fluoride (HF) in the presence of a nucleophile (scavenger), whose function is to trap the carbocations produced during SN1‐type reactions. Five peptide sequences were synthesised for evaluating p‐methoxyphenol effectiveness as a potent scavenger. After the synthesis, the resin–peptide was then separated into two equal parts to be cleaved using two scavengers: conventional reactive p‐cresol (reported in the literature as an effective acyl ion eliminator) and p‐methoxyphenol (hypothesised as fulfilling the same functions as the routinely used scavenger). Detailed analysis of the electrostatic potential map (EPM) revealed similarities between these two nucleophiles, regarding net atomic charge, electron density distribution, and similar pKa values. Good scavenger efficacy was observed by chromatography and mass spectrometry results for the synthesised molecules, which revealed that p‐methoxyphenol can be used as a potent scavenger during SPPS by t‐Boc/Bzl strategy, as similar results were obtained using the conventional scavenger.
Reaction wheel fault‐tolerant finite‐time control for spacecraft attitude tracking without unwinding
Authors: Lee Daero , Leeghim Henzeh
Published: April 2020

This article proposes fault‐tolerant finite‐time attitude tracking control of a rigid spacecraft actuated by four reaction wheels without unwinding problem in the presence of external disturbances, uncertain inertia parameter, and actuator faults. First, a novel antiunwinding finite‐time attitude tracking control law is derived with a designed control signal which works within a known actuator‐magnitude constraint using a continuous nonsingular fast terminal sliding mode (NFTSM) concept. Second, a finite‐time disturbance observer (FTDO) is introduced to estimate a lumped disturbance due to external disturbances, uncertain inertia parameter, actuator faults, and input saturation. Third, a composite controller is developed which consists of a feedback control based on the continuous NFTSM method and compensation term based on the FTDO. The global finite‐time stability is proved using Lyapunov stability theory. Moreover, the singularity and unwinding phenomenon are avoided. Simulation results are conducted under actuator constraints in the presence of external disturbances, inertia uncertainty, and actuator faults and results are illustrated to show the effectiveness of the proposed method. In addition, to show the superiority of the proposed control method over the recently reported control methods, comparative analysis is also presented.
Kinetic Resolution of Racemic 2‐Aryloxy Propionyl Chlorides Using Enantiopure (S)‐3,4‐Dihydro‐3‐methyl‐2H‐[1,4]benzoxazines
Authors: Vakarov Sergey A. , Chulakov Evgeny N. , Sadretdinova Liliya Sh. , Kodess Mikhail I. , Ezhikova Marina A. , Pervova Marina G. , Ganebnykh Ilya N. , Levit Galina L. , Krasnov Victor P.
Published: April 2020

Stereoselectivity in the mutual kinetic resolution (KR) of racemic 3,4‐dihydro‐3‐methyl‐2H‐[1,4]benzoxazines and racemic 2‐aryloxy propionyl chlorides was studied. Based on the results obtained, preparative methods for single enantiomers of a series of 2‐aryloxy propionic acids via acylative KR of their racemates with enantiopure (S)‐3,4‐dihydro‐3‐methyl‐2H‐[1,4]benzoxazines have been proposed.
Hierarchically Structured Bifunctional Electrocatalysts of Stacked Core–Shell CoS1−xPx Heterostructure Nanosheets for Overall Water Splitting
Authors: Boppella Ramireddy , Park Jaemin , Lee Hyungsoo , Jang Gyumin , Moon Jooho
Published: April 2020

The rational design and strategy of obtaining stable bifunctional electrocatalysts with unique functionalities are prerequisite to achieving robust catalytic activity. In this study, a composition‐controlled partial sulfurization/phosphorization strategy to synthesize a doughnut‐like 3D heterostructured electrocatalyst for overall water splitting is proposed, wherein core–shell 2D CoS1−xPx nanosheets decorated with N‐doped carbon are self‐assembled to form a hierarchical 3D architecture. The composition and phase structure in core–shell CoS1−xPx can be readily modified by controlling the liquid phase sulfurization and subsequent phosphorization, thereby modifying the electronic structure and activating the intrinsic active sites. The resulting CoS1−xPx benefits from the unique structural features including high accessible active surface area, adequate amount of reactive sites, intimate interfacial coupling between the components, interconnected electron highway, and accelerated charge/mass transfer ability. Consequently, the optimized CoS0.46P0.54 electrocatalyst achieves a catalytic current density of 10 mA cm−2 at overpotentials as low as 101 and 302 mV for hydrogen evolution reaction and oxygen evolution reaction, respectively, with outstanding long‐term operational stability in alkaline solution. The CoS0.46P0.54 couple enables an alkaline water electrolysis with a current density of 10 mA cm−2 at a low cell voltage of 1.62 V, comparable to that of the RuO2||Pt/C couple (1.6 V).
Erratum to: Leading higher-derivative corrections to Kerr geometry
Authors: Cano Pablo A. , Ruipérez Alejandro
Published: April 2020

There was an error when copying eqs. (4.41), (4.42) and (4.43) from the Mathematica file. The error does not propagate and, in particular, the figures are not affected.
Cationic liposomes for generic signal amplification strategies in bioassays
Authors: Hofmann Carola , Kaiser Barbara , Maerkl Susanne , Duerkop Axel , Baeumner Antje J.
Published: April 2020

Liposomes have been widely applied in bioanalytical assays. Most liposomes used bare negative charges to prevent non-specific binding and increase colloidal stability. Here, in contrast, highly stable, positively charged liposomes entrapping the fluorescent dye sulforhodamine B (SRB) were developed to serve as a secondary, non-specific label‚ and signal amplification tool in bioanalytical systems by exploiting their electrostatic interaction with negatively charged vesicles, surfaces, and microorganisms. The cationic liposomes were optimized for long-term stability (> 5 months) and high dye entrapment yield. Their capability as secondary, non-specific labels was first successfully proven through electrostatic interactions of cationic and anionic liposomes using dynamic light scattering, and then in a bioassay with fluorescence detection leading to an enhancement factor of 8.5 without any additional surface blocking steps. Moreover, the cationic liposomes bound efficiently to anionic magnetic beads were stable throughout magnetic separation procedures and could hence serve directly as labels in magnetic separation and purification strategies. Finally, the electrostatic interaction was exploited for the direct, simple, non-specific labeling of gram-negative bacteria. Isolated Escherichia coli cells were chosen as models and direct detection was demonstrated via fluorescent and chemiluminescent liposomes. Thus, these cationic liposomes can be used as generic labels for the development of ultrasensitive bioassays based on electrostatic interaction without the need for additional expensive recognition units like antibodies, where desired specificity is already afforded through other strategies.
The importance of including habitat-specific behaviour in models of butterfly movement
Authors: Evans Luke C. , Sibly Richard M. , Thorbek Pernille , Sims Ian , Oliver Tom H. , Walters Richard J.
Published: April 2020

Dispersal is a key process affecting population persistence and major factors affecting dispersal rates are the amounts, connectedness and properties of habitats in landscapes. We present new data on the butterflyManiola jurtinain flower-rich and flower-poor habitats that demonstrates how movement and behaviour differ between sexes and habitat types, and how this effects consequent dispersal rates. Females had higher flight speeds than males, but their total time in flight was four times less. The effect of habitat type was strong for both sexes, flight speeds were ~ 2.5 × and ~ 1.7 × faster on resource-poor habitats for males and females, respectively, and flights were approximately 50% longer. With few exceptions females oviposited in the mown grass habitat, likely because growing grass offers better food for emerging caterpillars, but they foraged in the resource-rich habitat. It seems that females faced a trade-off between ovipositing without foraging in the mown grass or foraging without ovipositing where flowers were abundant. We show that taking account of habitat-dependent differences in activity, here categorised as flight or non-flight, is crucial to obtaining good fits of an individual-based model to observed movement. An important implication of this finding is that incorporating habitat-specific activity budgets is likely necessary for predicting longer-term dispersal in heterogeneous habitats, as habitat-specific behaviour substantially influences the mean (> 30% difference) and kurtosis (1.4 × difference) of dispersal kernels. The presented IBMs provide a simple method to explicitly incorporate known activity and movement rates when predicting dispersal in changing and heterogeneous landscapes.
Open Creative Labs – Treffpunkte für Kreative?
Authors: Schmidt Suntje
Published: April 2020

Vor dem Hintergrund einer zunehmenden räumlichen und sozialen Fragmentierung von Erwerbsarbeit hinterfragt der vorliegende Beitrag, inwiefern Open Creative Labs Treffpunkte für Kreativschaffende anbieten und wodurch diese Treffpunkte charakterisiert sind. Hierfür werden zunächst „Dritte Orte“ als Treffpunkte vorgestellt, strukturelle Wandlungsprozesse in Arbeitsmärkten skizziert und Open Creative Labs als neuartige physisch-soziale Arbeitsumgebungen vorgestellt. Dabei soll verdeutlicht werden, dass Open Creative Labs weit mehr als Treffpunkte in der Kreativwirtschaft darstellen.
On the Anatomy of Medical Progress Within an Overlapping Generations Economy
Authors: Frankovic Ivan , Kuhn Michael , Wrzaczek Stefan
Published: April 2020

We study medical progress within a two-sector economy of overlapping generations subject to endogenous mortality. Individuals demand health care with a view to lowering mortality over their life-cycle. We characterise the individual optimum and the general equilibrium, and study the impact of a major medical innovation leading to an improvement in the effectiveness of health care. We find that general equilibrium effects dampen strongly the increase in health care usage following medical innovation. Moreover, an increase in savings offsets the negative impact on GDP per capita of a decline in the support ratio. Finally, we show that the reallocation of resources between the final goods and health care sector, following the innovation, plays a crucial role in shaping the general equilibrium impact.
How do the green components of urban green infrastructure influence the use of ecosystem services? Examples from Leipzig, Germany
Authors: Palliwoda Julia , Banzhaf Ellen , Priess Jörg A.
Published: April 2020

Context

The pressure on remaining open spaces of urban green infrastructure (UGI) is high due to increasing urbanization and the multiple requirements of a diverse urban population. Thus, a good quality and high capacity for ecosystem services of UGI is crucial to support a good quality of life.

Objectives

This study analyses the influence of tree cover and other green parameters like species richness on ecosystem service use in urban parks and green brownfields. The outcomes contribute to design and management of resilient UGI.

Methods

We assessed the diversity of woody and herbaceous flowering species in 36 study sites with low, medium and high tree cover in the city of Leipzig, Germany. UGI users were counted, and randomly selected visitors (n = 1750) were interviewed about their use of ecosystem services.

Results

We found tree cover in urban parks negatively influencing physical interactions used by respondents. In parks with high tree cover, more respondents were benefitting from regulating services such as noise mediation or shade provision. Brownfield visitors preferred sites with low to medium tree cover, mainly for walking the dog but also for other ecosystem services. Plant species richness did not show significant influence.

Conclusions

Tree cover in parks and brownfields can be a predictor for a range of ecosystem services typically used by visitors, highlighting how vegetation or green structures in UGI can be employed to steer the use. Brownfields provide additional space for complementary ecosystem service use, thus contributing to the avoidance of potential use conflicts in managed UGI like parks.
Development and application of indica–japonica SNP assays using the Fluidigm platform for rice genetic analysis and molecular breeding
Authors: Seo Jeonghwan , Lee Gileung , Jin Zhuo , Kim Backki , Chin Joong Hyoun , Koh Hee-Jong
Published: April 2020

Molecular markers are efficient and essential genotyping tools for molecular breeding and genetic analysis of rice. We developed two 96-plex indica–japonica single nucleotide polymorphism (SNP) genotyping sets for genetic analysis and molecular breeding in rice using the Fluidigm platform. Informative SNPs between indica and japonica were selected from SNP data of the Rice Diversity database, HapRice world SNP data of the Q-TARO database, and our 40 rice cultivar resequencing dataset. SNPs in set 1 were evenly distributed across all 12 rice chromosomes at a spacing of 4–5 Mb between adjacent SNPs. SNPs in set 2 mapped to the long genetic intervals in set 1 and included 14 functional or linked SNPs in genes previously cloned and associated with agronomic traits. Additionally, we used the SNP sets developed in this study to perform genetic diversity analysis of various cultivated and wild rice accessions, construction and validation of a subspecies diagnostic subset, linkage map construction and quantitative trait locus (QTL) analysis of a japonica × indica F2 population, and background profiling during marker-assisted backcrossing. Furthermore, we identified subspecies-specific SNPs and discuss their distribution and association with agronomic traits and subspecies differentiation. Our results indicate that these subspecies-specific SNPs were present in wild rice prior to domestication. This genotyping system will serve as an efficient and quick tool for genetic analysis and molecular breeding in rice.
Formation and Evolution of Disks Around Young Stellar Objects
Authors: Zhao Bo , Tomida Kengo , Hennebelle Patrick , Tobin John J. , Maury Anaëlle , Hirota Tomoya , Sánchez-Monge Álvaro , Kuiper Rolf , Rosen Anna , Bhandare Asmita , Padovani Marco , Lee Yueh-Ning
Published: April 2020

Recent observations have suggested that circumstellar disks may commonly form around young stellar objects. Although the formation of circumstellar disks can be a natural result of the conservation of angular momentum in the parent cloud, theoretical studies instead show disk formation to be difficult from dense molecular cores magnetized to a realistic level, owing to efficient magnetic braking that transports a large fraction of the angular momentum away from the circumstellar region. We review recent progress in the formation and early evolution of disks around young stellar objects of both low-mass and high-mass, with an emphasis on mechanisms that may bridge the gap between observation and theory, including non-ideal MHD effects and asymmetric perturbations in the collapsing core (e.g., magnetic field misalignment and turbulence). We also address the associated processes of outflow launching and the formation of multiple systems, and discuss possible implications in properties of protoplanetary disks.
The effects of video lecture viewing strategies on cognitive load
Authors: Costley Jamie , Fanguy Mik , Lange Chris , Baldwin Matthew
Published: April 2020

Ideally, instruction should be delivered in a way that reduces the processing of information that does not contribute to learning (extraneous load) and increases cognitive processing that contributes to learning (germane load). One way students might effectively manage extraneous load is through specific video lecture viewing strategies to control the flow of information. Extant research provides conflicting perspectives regarding the role of viewing strategies within video lectures in improving learning. This study analyzed survey responses from a group of university students (n = 2012) participating in online classes in South Korea and looked at the mediating effect of video lecture viewing strategies on the relationship between extraneous load and germane load. The results showed that viewing strategies mediated the relationship between extraneous load and germane load. When viewing strategies were added to the model, the large negative relationship between extraneous load and germane load reversed to become a small positive relationship, implying that the negative correlation between extraneous load and germane load can be largely mitigated by students engaging in specific viewing strategies to better understand the content.
Auswirkungen verschachtelten Lernens auf das prozedurale und konzeptuelle Wissen von Lernenden über Zuordnungen
Authors: Borromeo Ferri Rita , Pede Stella , Lipowsky Frank
Published: April 2020

Häufig werden im Mathematikunterricht Lerninhalte eher separiert behandelt. Der Ansatz des sogenannten verschachtelten Lernens geht dagegen davon aus, dass es in vielen Fällen sinnvoll ist, die Lerninhalte abwechselnd und vermischt anzuordnen, um bei den Schülerinnen und Schülern lern- und verstehensförderliche Prozesse anzuregen sowie nachhaltiges Lernen zu fördern. Verschachteltes Lernen zählt zu den wünschenswerten Erschwernissen. Das Ziel der wünschenswerten Erschwernisse ist, durch eine Erhöhung des kognitiven Aufwandes beim Lernen einen langfristigen Lernerfolg zu erreichen. Die in diesem Artikel beschriebene Studie untersucht Effekte des verschachtelten Lernens gegenüber dem sogenannten geblockten Lernen, bei dem Inhalte nacheinander erarbeitet und geübt werden. Die Studie wurde mit Lernenden des Jahrgangs 7 durchgeführt, die in einer 8‑stündigen Unterrichtseinheit das Thema „Zuordnungen“ entweder geblockt oder verschachtelt lernten. Das Design der experimentellen Studie sah die parallelisierte Zuweisung der Lernenden zu beiden Bedingungen und die Messung des Lernerfolgs zu drei Messzeitpunkten (Post- und zwei Follow-Up-Tests) vor. Die Ergebnisse der Studie zeigen, dass sich das verschachtelte gegenüber dem geblockten Lernen nachhaltig auf das konzeptuelle Wissen der Lernenden auswirkt, während in der Entwicklung des prozeduralen Wissens keine Unterschiede festzustellen waren.
Are the natural sciences ready for truth, healing, and reconciliation with Indigenous peoples in Canada? Exploring ‘settler readiness’ at a world-class freshwater research station
Authors: Bozhkov Elissa , Walker Chad , McCourt Vanessa , Castleden Heather
Published: April 2020

The Experimental Lakes Area in Northwestern Ontario, Canada, is a globally prominent freshwater research facility, conducting impactful whole-of-lake experiments on so-called ‘pristine’ lakes and watersheds. These lakes are located in traditional Anishinaabe (Indigenous) territory and the home of 28 Treaty #3 Nations, something rarely acknowledged until now. Indeed, Indigenous peoples in the area have historically been excluded from the research facility’s governance and research. Shortly after it changed hands in 2014—from the federal government to the not-for-profit International Institute of Sustainable Development (IISD)—the Truth and Reconciliation Commission (TRC) of Canada released its Calls to Action to all Canadians. The newly named International Institute of Sustainable Development-Experimental Lakes Area (IISD-ELA) began to respond with a number of initiatives aimed to develop relationships with local Indigenous peoples and communities. In this paper, from the perspectives of IISD-ELA staff members, we share findings from an exploratory study into the relationships beginning to develop between IISD-ELA and Treaty #3 Nations. We used semi-structured interviews (n = 10) to identify how staff perceived their initial efforts and contextualize those with the current literature on meaningfully engagement in reconciliation. Our analysis highlights perceived barriers, including time, resources, and funding constraints, as well as an acknowledged lack of cultural awareness and sensitivity training. Participants also recognized the need to engage Indigenous knowledge holders and embrace their ways of knowing at the research station. While the study is small in scale, as an international leader in freshwater science, transparency in the IISD-ELA’s journey in reconciliation has the potential to inform, influence, and ‘unsettle’ settler-colonial scientists, field stations, and institutions across the country and beyond.
When quick response codes didn’t do the trick
Authors: Walcott-Bedeau Gabrielle , Raeburn Kazzara , Burkhardt Dirk , Clunes Mark
Published: April 2020

Medical education programs in the United States or Canada comply with the Liaison Committee on medical education standards to ensure their graduates provide proficient medical care. One standard includes student development as a lifelong learner. The competency of lifelong learning is developed through self-directed activities such as students evaluating their learning objectives and resources without external help.

Quick response (QR) codes were the technological tools introduced in a traditional medical institution to enhance students’ self-directed initiative to tap resources. Relevant lecture objectives and other information such as supplemental discipline content, reading assignments and web-based link resources were embedded into codes and ‘pasted’ onto all pages of their course PDF handouts. It was anticipated that most students had access to smart phones to conveniently scan the codes and retrieve the information.

However, an in-class survey conducted showed that only 30% of the students found the QR codes useful. Further questioning revealed that some students just didn’t know how to use the codes or didn’t think the information embedded was worth the effort to decrypt. Although students were tech-savvy in the social and entertainment realms, they were not adept in the use of technology for educational purposes.

QR codes presented several theoretical, pedagogical advantages to enhance experiential and self-directed learning. However, implementation among students, in a traditional classroom, required prior instructions on usage. Student feedback was also imperative when introducing novel, innovative tools like QR codes.