bluuebunny/crossref_metadata_2025 huggingface dataset:
Photoredox-catalysed regioselective synthesis of C-4-alkylated pyridines with N-(acyloxy)phthalimides
Authors: Zhang Zhucheng , He Qian , Zhang Xiaofei , Yang Chunhao
Published: February 2022

Herein, a method of direct C-4 selective alkylation of pyridines under visible light irradiation was reported.
Molecular editing in natural product synthesis
Authors: Hui Chunngai , Wang Zhuo , Wang Shiping , Xu Chunfa
Published: February 2022

Molecular editing entailing insertion and deletion of atom(s) enables new synthetic design and the efficiency of natural product synthesis could be improved.
A simple predictor of interface orientation of fluids of disk-like anisotropic particles and its implications for organic semiconductors
Authors: Boehm Belinda J. , Huang David M.
Published: February 2022

A simple and general predictor of molecular orientation at solid and vapour interfaces of isotropic fluids of disk-like particles is identified from classical molecular dynamics simulations of particles modelled on typical organic semiconductors.
A digital signal processor‐efficient accelerator for depthwise separable convolution
Authors: Li Xueming , Huang Hongmin , Liu Yuan , Hu Xianghong , Xiong Xiaoming
Published: February 2022

Recent researches on deep convolution neural networks have proposed some compact networks, such as MobileNet, but its main computation, depthwise separable convolution (DWC), which reduces the reusable data and improves the requirement of data loading efficiency. Although DWC can effectively reduce the amount of network computation, it needs a special accelerator to enhance the inference speed. This paper proposes a high‐performance accelerator for DWC based on the commonly used acceleration platform field‐programmable gate array. The proposed accelerator supports the computation of both standard convolutions (SCs) and DWC as well as two activation functions. In addition, two data storage formats are used to maintain the data loading efficiency for different input requirements of SC and DWC under high parallelism. Furthermore, a processing unit that can execute two 8 × 8‐bit multiplications inside one digital signal processor (DSP) is designed to make the best use of the DSP hardware resources. Finally, the accelerator is implemented on ZYNQ ZC706 at 200 MHz. Consuming only 392 DSPs, the accelerator achieves 134.5 giga operations per second (GOPS) and 209.4 frames per second (FPS) on MobileNet V1 as well as 96.4 GOPS and 250.4 FPS on MobileNet V2. Experimental results demonstrate that this design provides a better DSP efficiency than previous works.
Simple analytical model for accurate switching loss calculation in power MOSFETs using non‐linearities of Miller capacitance
Authors: Prado Edemar O. , Bolsi Pedro C. , Sartori Hamiltom C. , Pinheiro José Renes
Published: February 2022

A simple and accurate analytical model for the estimation of switching losses on power MOSFETs is proposed. It consists of simplifying the non‐linear behaviour of Miller capacitance as a function of voltage. Experimental results are used to validate the model in the 5–500 kHz range. The proposed analytical model is compared to other frequently used methods. Results confirm the accuracy of the proposed model in different voltage levels, using four different MOSFET part numbers, spanning three technologies: SiC, superjunction, and conventional silicon. Because of its simplicity of implementation, it is especially recommended for applications that design converters by evaluating a large database of transistor part numbers.
A highly efficient power block with series connection of power SiC MOSFETs‐design, characterization and assessment in MV converters
Authors: Li Chengmin , Lu Zhebie , Zhu Ankang , Li Chushan , Luo Haoze , Li Wuhua , He Xiangning
Published: February 2022

Implementation of the series connection of the SiC MOSFETs in medium voltage (MV) high power converters faces a series of challenges, including the electrical/thermal stress imbalance, insulation coordination design, high dv/dt elimination and robustness under variable operating conditions. This paper stresses these challenges and proposes a comprehensive design of a 9.6 kV/200 A power block based on the series connection of SiC MOSFETs. The power block has been verified under the continuous operation, which demonstrates the highly efficient and reliable operation under the variable switching current condition. Afterward, performance screening in a 5 kV/1 MW inverter is conducted to assess the efficiency in MV converters. Compared with the advanced high voltage high power devices, the proposed power block demonstrates fast switching speed and low switching loss, which indicates that the series connection of SiC MOSFETs is a promising technique to expand the operation voltage/power of the SiC MOSFETs to the MV megawatt level. The proposed design can be expanded to other specifications as well.
Distribution of dust ejected from the lunar surface into the Earth-Moon system
Authors: Yang Kun , Schmidt Jürgen , Feng Weiming , Liu Xiaodong
Published: February 2022

Aims. An asymmetric dust cloud was detected around the Moon by the Lunar Dust Experiment on board the Lunar Atmosphere and Dust Environment Explorer mission. We investigate the dynamics of the grains that escape the Moon and their configuration in the Earth-Moon system.

Methods. We use a plausible initial ejecta distribution and mass production rate for the ejected dust. Various forces, including the solar radiation pressure and the gravity of the Moon, Earth, and Sun, are considered in the dynamical model, and direct numerical integrations of trajectories of dust particles are performed. The final states, the average life spans, and the fraction of retrograde grains as functions of particle size are computed. The number density distribution in the Earth-Moon system is obtained through long-term simulations.

Results. The average life spans depend on the size of dust particles and show a rapid increase in the size range between 1 and 10 μm. About 3.6 × 10−3 kg s−1 (~2%) particles ejected from the lunar surface escape the gravity of the Moon, and they form an asymmetric torus between the Earth and the Moon in the range [10 RE, 50 RE], which is offset toward the direction of the Sun. A considerable number of retrograde particles occur in the Earth-Moon system.
Weak line discovered by Voyager 1 in the interstellar medium: Quasi-thermal noise produced by very few fast electrons
Authors: Meyer-Vernet N. , Lecacheux A. , Issautier K. , Moncuquet M.
Published: February 2022

A weak continuous line has been recently discovered onboard Voyager 1 in the interstellar medium, whose origin raised two major questions. First, how can this line be produced by plasma quasi-thermal noise on the Voyager short antenna? Second, why does this line emerge at some distance from the heliopause? We provide a simple answer to these questions, which elucidates the origin of this line. First, a minute quantity of supra-thermal electrons, as generally present in plasmas – whence the qualifier ‘quasi-thermal’ – can produce a small plasma frequency peak on a short antenna, of amplitude independent of the concentration of these electrons; furthermore, the detection required long spectral averages, alleviating the smallness of the peak compared to the background. We therefore attribute the observed line to a minute proportion of fast electrons that contribute negligibly to the pressure. Second, we suggest that, up to some distance from the heliopause, the large compressive fluctuations ubiquitous in this region prevent the line to emerge from the statistical fluctuations of the receiver noise because it is blurred out by the averaging required for detection, especially in the presence of short-wavelength density fluctuations. These results open up novel perspectives for interstellar missions, by showing that a minute proportion of fast electrons may be sufficient to measure the density even with a relatively short antenna, because the quietness of the medium enables a large number of spectra to be averaged.
Comparison study of rust layers formed on Q420 and weathering steel after 6 years of exposure in marine atmospheres
Authors: Chen Yunxiang , Xia Xiaojian , Huang Yao , Hong Yicheng , Lin Deyuan , Lu Yanjin
Published: February 2022

In this study, the corrosion products formed on Q420 and weathering steel (WS) after 6 years of exposure in marine atmospheres in Pingtan, Fujian Province in China was examined. The evolution of the rust layers in terms of surface and cross-sectional morphologies were observed by SEM, while the consisted phases on the Q420 and WS were detected by XRD. The protective effect of the rust layers on the steels was studied by the electrochemical tests. The results of weight loss indicated that the Q420 had a relatively higher corrosion rate than that of the WS steel. The SEM observation showed that the WS steel could form a relative compact with fewer cracks after a long time of exposure concerning the Q420 steel. The electrochemical tests suggested the rust layer formed in the initial stage for the Q420 steel showed a better protective effect than that one formed at a later stage, whereas a better protective effect of the rust layer was formed at the later stage for the WS steels.
Effects of nitrogen rates on yield, yield components, and other related attributes of different rapeseed (Brassica napus L.) varieties
Authors: Yahbi Mohammed , Nabloussi Abdelghani , Maataoui Abdelwahed , El Alami Nabila , Boutagayout Abdellatif , Daoui Khalid
Published: February 2022

Rapeseed is one of the most important oilseed crops in the world and, in Morocco, it may contribute to the improvement of food security in edible oils through developing performant cultivars and optimizing the crops management including nitrogen fertilization. The objective of this study was to evaluate the response of different Moroccan varieties to nitrogen application. Field trials were carried out at the experimental station of National School of Agriculture in Meknes, during two cropping seasons (2017–2018 and 2018–2019). Five varieties (“Narjisse”, “Moufida”, “Alia”, “Adila”, and “Lila”) were combined to different nitrogen rates (0, 30, 60, and 90 kg N ha−1). The experimental design adopted is a split split-plot with three replications, where nitrogen treatment was affected to main plot, variety to subplot, and year to sub-subplot. Results showed that dry matter, harvest index, oil content, seed yield per plant and yield components were significantly affected by nitrogen rates, with an upward trend in seed yield as the nitrogen rates increased. On average, seed yield increased by 50.33% for application of 90 kg N ha−1 compared to the control (without N fertilization). However, oil content declined from 41.08% to 37.81% with the increase of nitrogen level from 0 to 90 kg N ha−1. Additionally, for the other traits studied, the highest mean values were observed for 90 kg N ha−1, except harvest index which exhibited the greatest value for 60 kg N ha−1. Variation among the varieties was significantly large for all traits studied with a superiority of the variety “Alia” for seed yield per plant (9.82 g plant−1), number of pods per plant (151), and number of seeds per pod (24.05).
Anti-Toxoplasma gondii effect of lupane-type triterpenes from the bark of black alder (Alnus glutinosa) and identification of a potential target by reverse docking
Authors: Darme Pierre , Escotte-Binet Sandie , Cordonnier Julien , Remy Simon , Hubert Jane , Sayagh Charlotte , Borie Nicolas , Villena Isabelle , Voutquenne-Nazabadioko Laurence , Dauchez Manuel , Baud Stéphanie , Renault Jean-Hugues , Aubert Dominique
Published: February 2022

Toxoplasmosis is a worldwide parasitosis that is generally benign. The infestation may pose a risk to immunocompromized patients and to fetuses when pregnant women have recently seroconverted. Current treatments have numerous side effects and chemoresistance is emerging, hence the need to find new anti-Toxoplasma gondii substances. This study focuses on the antiparasitic potential of lupane-type pentacyclic triterpenes isolated from the bark of black alder (Alnus glutinosa), as well as the hypothesis of their macromolecular target by an original method of reverse docking. Among the isolated triterpenes, betulone was the most active compound with an IC50 of 2.7 ± 1.2 μM, a CC50 greater than 80 μM, and a selectivity index of over 29.6. An additional study of the anti-T. gondii potential of commercially available compounds (betulonic acid methyl ester and betulonic acid) showed the important role of the C3 ketone function and the C28 oxidation level on the lupane-type triterpene in the antiparasitic activity since their IC50 and CC50 were similar to that of betulone. Finally, the most active compounds were subjected to the AMIDE reverse docking workflow. A dataset of 87 T. gondii proteins from the Protein Data Bank was created. It identified calcium-dependent protein kinase CDPK3 as the most likely target of betulin derivatives.
The Fashion Industry and its Problematic Consequences in the Green Marketing Era a Review
Authors: Sagapova Nikola , Buchtele Roman , Dušek Radim
Published: February 2022

This paper uses a narrative literature review to provide evidence of the problematic consequences of the fast fashion industry in the context of sustainability and to consider the option of the green marketing approach as a way of reducing negative impacts. Studies relevant to our research were identified through a search of Web of Science, Science Direct, Scopus and Google Scholar. In recent years, environmental sustainability has played an important role on the political agenda, but it is also driving innovation in business. The range of environmentally friendly products on the market is increasing, and consumers are showing interest in buying these types of products, which are usually more expensive. Unfortunately, fashion production is one of the least sustainable industries. Therefore, more and more fashion companies are trying to implement green approaches in their value chains. Green marketing in the context of the fashion industry essentially refers to products that are produced with respect to working conditions and the environment, and to the possibility of finding a compromise between business objectives and environmental issues.
Human Resource Management Strategy as a Small Business Competitive Advantage Tool
Authors: Urban Jan
Published: February 2022

The goal of a company’s HR management (HRM) strategy is to define its medium-term objectives in HRM and development as well as to specify the main management tools needed for their achievement. The HRM goals set by this strategy should be linked to the company’s strategic business goals and respond in advance to its medium term HRM requirements dictated by both internal and external factors. Corresponding HRM measures and/or policies should be effective in terms of achieving HRM objectives, as well as efficient in terms of their costs and benefits relations. The purpose of this paper based on a qualitative analysis of interviews with small business owners focused on the importance of their HRM strategy for the competitive advantage of their emerging companies, as well as on relevant secondary sources, is to outline a particular methodology and the main characteristics of successful HRM strategies. The main attention is drawn to the linkage of the HRM strategy to the overall companies´ business strategies as well as their appropriate contents and structure.
Endovascular Revascularization as a Treatment Option for Peripheral Arterial Disease due to Diabetes in Saudi Arabia: Public Awareness Survey
Authors: Alshammari Afnan Hammad Ali , Alshurtan Noura Hamad Rasheed , Alshammeri Amirah Fahad Mohammed , Alharbi Abdulaziz Ayied Abdullah
Published: February 2022

Objectives Diabetic foot disease is a common and serious complication of diabetes that represents a major global health concern with high mortality and morbidity rates. Successful revascularization and improved perfusion have had fundamental roles in reducing the rate of amputation in diabetic foot patients over the last decade. Creating public awareness plays a key role in early treatment and prevention of amputation. The aim of this study was to determine if people are aware of endovascular revascularization as a therapeutic option for diabetes-related peripheral artery disease.

Methods The study is a community-based observational descriptive cross-sectional study that was conducted to assess Saudi population knowledge and awareness about endovascular revascularization as a treatment option of diabetic foot disease through interventional radiology. The self-administered online survey was randomly distributed with a maximum of 20 multiple choice questions through social media channels.

Results Endovascular revascularization as a treatment of diabetes-related peripheral artery disease through interventional radiology was unknown to 90.2% of the participants. Awareness has been influenced by many factors including age, occupation, and family history.

Conclusion This study highlights the importance of raising public awareness about endovascular revascularization as a treatment option for diabetes-related peripheral arterial disease in suitable patients.
Knowledge, Attitude, and Practice Toward Mask-Wearing Behaviors During Covid-19 Pandemic Among Mangalore Residents: A Cross-Sectional Study
Authors: Krishna Nidhish , Ramesh Athul , Hegde Amitha M.
Published: February 2022

Objectives The objective of this study is to assess the knowledge, awareness, and practice toward mask-wearing behaviors of Mangalore residents during the coronavirus disease 2019 (COVID-19) outbreak.

Materials and Methods This survey was conducted at A B Shetty Memorial Institute of Dental Sciences in Mangalore. The questionnaire consisted of 18 questions that were prepared as an online form (Google Forms), and a total of 172 responses were received among the residents of Mangalore who visited the hospital.

The questions were distributed based on knowledge, attitude, and practice regarding the mask-wearing behaviors, and the distribution of responses was presented as frequency and percentages. Prior to the inception of the study, the nature and purpose of the study were explained to each respondent, and informed consent was obtained by all participants in this study.

Statistical analysis was done using SPSS software version 23.

Results It was evident that the COVID-19 knowledge scores were found to be significantly associated with a lower likelihood of negative attitudes and potentially dangerous practices toward the COVID-19 epidemic in this study. These findings clearly indicate the importance of improving residents' COVID-19 knowledge via health education, which may also result in improvements in their attitudes and practices toward COVID-19.

Conclusion In summary, our findings suggest that Mangalore residents have fair knowledge and optimistic attitudes, despite the current lockdown measures undertaken during the second wave of COVID-19, The positivity rate in Mangalore has not reduced satisfactorily. Self-protection, testing, and vaccination would help to reduce the spread and mortality rate due to coronavirus. The residents of Mangalore should abide by the COVID -19 preventive measures and implement this knowledge into their daily practices.
Challenges in the Histopathologic Diagnosis of Brain Tumors: An Institutional Experience in a Series of Cases
Authors: Shetty Jayaprakash K. , Prasad Kishan H.L. , S. Shruthi , Raghothaman Ananthan
Published: February 2022

Background Central nervous system (CNS) tumors are relatively rare. However, brain tumors are one of the leading causes of cancer-related morbidity and mortality. Accurate histopathologic diagnosis and molecular diagnostics are critical for managing these patients. Histopathology plays a vital role in diagnosis, but clinical and radiological information is also crucial while evaluating brain tumors.

Materials and Methods A cross-sectional observational study was performed for a period of 1 year in the pathology department of a tertiary hospital. All the brain biopsies sent for histopathological analysis were analyzed, and among which five brain biopsy tissue posing the diagnostic dilemma in conventional histopathology were included in the study. Immunohistochemistry was performed wherever necessary.

Results During the study period, we encountered 32 cases of brain biopsy. Five cases posing diagnostic challenges in histopathological diagnosis were included in the study. Expert opinions of neuropathologists were taken in all of these cases. We reviewed the cases for the diagnostic difficulties. A review of all these cases has impacted further treatment.

Conclusion In this case series, we present five CNS tumors with a diagnostic dilemma in histopathological diagnosis where clinicoradiological correlation, immunohistochemistry, and expert opinion helped in the definitive diagnosis revealing the importance of a multidisciplinary approach for the better management of patients.
Neonatal Meningitis with Septicemia by Elizabethkingia meningoseptica: A Case Report
Authors: Murthy Neetha S. , Shivappa Sowmya G. , Tejashree A. , Karthik Krishna M.V.S. , Deepashree R.
Published: February 2022

Elizabethkingia is ubiquitary aerobic bacillus abundantly found in the community as well as hospital environments. Elizabethkingia meningoseptica is an emerging nosocomial pathogen with an elemental ability to acclimate and survive in diversified environmental circumstances. Prompt diagnosis and an early therapeutic intervention are preponderant in the management of these infections. We report a case of meningitis with septicemia caused by E. meningoseptica in a 1-day-old outborn neonate. The child was stabilized with anticonvulsants and, based on laboratory findings, the neonate was started on ciprofloxacin in addition to symptomatic management. The child responded well to the treatment and was discharged on day 7 after treatment initiation. Perceptive treatment protocols backed with accurate laboratory evidence remain instrumental to avert unpropitious outcomes while combatting rare multidrug-resistant opportunistic infections.
Simulations shed light on key process in semiconductor device manufacturing
Authors: Ikenson Ben
Published: February 2022

Classical molecular dynamics reveal intricacies of silicon atomic layer etching process with alternating exposure to chlorine gas and argon ions
Bonding wire interconnection de-embedding for GaN high electron mobility transistor loadpull measurement with fixture
Authors: Wang Lu-Lu , Fang Wen-Rao , Huang Wen-Hua , Li Jia-Wei , Shao Hao , Fu Chao , He Tian-Wei
Published: February 2022

Test fixtures with high power capacity and an impedance matching network are generally chosen for measurements of high-power gallium nitride high electron mobility transistors. To make interconnection of the test fixtures and devices under test, wire bonding is an effective assembly method. Bonding wires become dominant parasitic elements, especially in the S parameter measurement and loadpull measurement, which should be taken into account and accurately de-embedded for device measurements and modeling. In this paper, test fixtures and through-reflect-line calibration kits are designed to achieve the S parameter measurements of the bonding wire with a vector network analyzer. Equivalent inductances of the bonding wire can be obtained with the electromagnetic simulation model and compact circuit model proposed based on the test fixture. The good agreement of the equivalent inductances extracted with the test fixture and models verified that the way to characterize bonding wire interconnection is effective and accurate. Cree’s CGHV1J006D is chosen to take the S parameter measurement for proving the accurate model of the bonding wire. Finally, the equivalent inductance of the 2 mm gate-width transistor is obtained with the electromagnetic model. The drain impedance is accurately calculated after the loadpull measurement with bonding wire effects de-embedded, which matches the loadline theory.
Simultaneously enhanced electrical conductivity and suppressed thermal conductivity for ALD ZnO films via purge-time controlled defects
Authors: Ghiyasi Ramin , Milich Milena , Tomko John , Tewari Girish C. , Lastusaari Mika , Hopkins Patrick E. , Karppinen Maarit
Published: February 2022

We demonstrate the simultaneous manipulation of electrical and thermal transport characteristics of ZnO thin films fabricated via the prototype atomic layer deposition (ALD) process from diethyl zinc (DEZ) and water precursors. The key ALD process parameter is the length of the N2 purge applied after the DEZ precursor pulse. We characterize the thin films with x-ray reflectivity measurements for the film growth characteristics, with photoluminescence spectroscopy for structural defects, with electrical transport measurements for carrier density, electrical resistivity, and Seebeck coefficient, and with time-domain thermoreflectance measurements for thermal conductivity. Photoluminescence spectroscopy data suggest that elongation of the purge period creates structural defects, which increase the electron carrier density; this would explain the enhanced electrical conductivity of the films. At the same time, the defects are likely to hinder the thermal transport in the films. The, thus, realized simultaneous increase in electrical conductivity and decrease in thermal conductivity are of fundamental importance in thermoelectrics. Moreover, the simple control of the intrinsic electrical transport properties is highly desired for the semiconducting ZnO films in optics and microelectronics.
Follicle-stimulating hormone regulates Notch signalling in the seminiferous epithelium of continuously and seasonally breeding rodents
Authors: Lustofin Sylwia , Kamińska Alicja , Brzoskwinia Małgorzata , Pardyak Laura , Pawlicki Piotr , Szpręgiel Izabela , Bilińska Barbara , Hejmej Anna
Published: February 2022

Context Juxtacrine (contact-dependent) communication between the cells of seminiferous epithelium mediated by Notch signalling is of importance for the proper course of spermatogenesis in mammals. Aims The present study was designed to evaluate the role of follicle-stimulating hormone (FSH) in the regulation of Notch signalling in rodent seminiferous epithelium. Methods We explored the effects (1) of pharmacological inhibition of the hypothalamus–pituitary–gonadal (HPG) axis and FSH replacement in pubertal rats, and (2) of photoinhibition of HPG axis followed by FSH substitution in seasonally breeding rodents, bank voles, on Notch pathway activity. Experiments on isolated rat Sertoli cells exposed to FSH were also performed. Gene and protein expressions of Notch pathway components were analysed using RT-qPCR, western blot and immunohistochemistry/immunofluorescence. Key results Distribution patterns of Notch pathway proteins in bank vole and rat seminiferous epithelium were comparable; however, levels of activated Notch1 and Notch3, hairy/enhancer of split 1 (HES1) and hairy/enhancer of split-related with YRPW motif 1 (HEY1) in bank voles were dependent on the length of the photoperiod. In response to FSH similar changes in these proteins were found in both species, indicating that FSH is a negative regulator of Notch pathway activity in seminiferous epithelium. Conclusions Our results support a common mechanism of FSH action on Notch pathway during onset and recrudescence of spermatogenesis in rodents. Implications Interaction between FSH signalling and Notch pathway in Sertoli cells may be involved in spermatogenic activity changes of the testes occurring during puberty or photoperiod shift in continuously and seasonally breeding rodents, respectively.
Influences of grassland to cropland conversion on select soil properties, microbiome and agricultural emissions
Authors: Lai Liming , Yilmaz Turhan , Kumar Sandeep , Fennell Anne , Gonzalez Hernandez Jose L.
Published: February 2022

Context Conversion of grasslands to croplands can usually result in the degradation of soils and increased greenhouse gas (GHG) emissions such as carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4). However, little is known about the impacts of grassland conversion to recently tilled croplands on soils and GHG fluxes. Aims A field experiment was established in 2016 to evaluate the impacts of grassland conversion to tilled cropland under different landscape positions (upslope, backslope, and footslope) on select soil properties and soil GHG fluxes. Key results The findings showed that the grassland conversion significantly increased soil bulk density and electrical conductivity but reduced pH and total nitrogen (TN). The conversion impacted soil biome community grassland and tilled croplands. The landscape position significantly impacted soil pH (footslope < upslope) and TN (footslope > upslope). The grassland conversion significantly decreased soil CO2 fluxes, but increased soil CH4 and N2O fluxes. The landscape position significantly impacted soil CO2 (footslope > upslope and backslope) and CH4 (upslope > footslope and backslope) fluxes for some periods. Soil CO2 and N2O fluxes generally followed upward and downward trends over time, respectively. Conclusions These results indicate that grassland conversion was able to lose soil N, increase soil compaction, acidity, salts, and soil N2O and CH4 fluxes, and decrease the diversity of abundant genera and CO2 fluxes. Footslope increased TN, soil acidity, CO2, and CH4 fluxes, compared with upslope and backslope. CO2 fluxes under grassland and tilled cropland significantly increased over time, whereas N2O fluxes under grassland significantly reduced. Implications Conversion of grassland to tilled cropland significantly impacted on sol quality. It caused a loss in soil N and increased soil compaction, acidity and salts. Grassland conversion also decreased the abundance and diversity soil microbiome.
Influence of no-till cover crop management on soil thermal properties
Authors: Haruna Samuel I. , Anderson Stephen H.
Published: February 2022

Context Soil thermal properties influence soil health parameters and can help determine crop productivity with changing global atmospheric climate. Aim This study investigated the influence of no-till (NT) and cover crop (CC) management on soil thermal properties. Methods The study site was managed with NT. The CCs used included hairy vetch (Vicia villosa Roth.), crimson clover (Trifolium incarnatum L.), winter wheat (Triticum aestivum L.), winter peas (Lathyrus hirsutus L.), oats (Avena sativa), triticale (Triticale hexaploide Lart.), barley (Hordeum vulgare L.) and flax (Linum usitatissimum L.). Soil samples were collected at 0–10, 10–20, and 20–30 cm depths just prior to CCs being planted and also collected just before CCs were terminated. Treatments included NT CC and NT no cover crop (NC). Soil thermal properties (thermal conductivity [λ], volumetric heat capacity [C V], and thermal diffusivity [D]) were measured at 0, −33, and −100 kPa soil water pressures. Key Results CV at saturation was 13% higher under CC management compared with NC management. Averaged over all depths just before CC termination, λ and D at saturation were 21 and 35% higher, respectively, under NC management compared with CC management probably due to closer contact between soil particles. Conclusions Results from this study suggest CCs with NT management may be able to resist extreme soil temperature changes which could improve soil health and crop productivity in these systems. Implications NT and CC could improve crop productivity in the future but more in situ studies of soil thermal properties under these systems are needed.
Protein kinase Cγ in cerebellar Purkinje cells regulates Ca
2+
-activated large-conductance K
+
channels and motor coordination
Authors: Watanave Masashi , Takahashi Nobutaka , Hosoi Nobutake , Konno Ayumu , Yamamoto Hikaru , Yasui Hiroyuki , Kawachi Mika , Horii Takuro , Matsuzaki Yasunori , Hatada Izuho , Hirai Hirokazu
Published: February 2022

Significance

The cerebellum, the site where protein kinase C (PKC) was discovered, contains the highest amount of PKCγ in the central nervous system. PKCγ in the cerebellum is exclusively confined to Purkinje cells (PCs), sole outputs from the cerebellar cortex. Systemic PKCγ-knockout mice show impaired motor coordination; however, the cause of motor defects remains unknown. Here we show that activation of PKCγ suppresses the Ca
2+
-activated large-conductance K
+
(BK) channels located along the PC dendrites. A consequential increase in the membrane resistance attenuates electrical signal decay during propagation, resulting in an altered complex spike waveform. Our results suggest that synaptically activated PKCγ in PCs plays a critical role in motor coordination by negative modulation of BK currents.
Persistent soil carbon enhanced in Mollisols by well-managed grasslands but not annual grain or dairy forage cropping systems
Authors: Rui Yichao , Jackson Randall D. , Cotrufo M. Francesca , Sanford Gregg R. , Spiesman Brian J. , Deiss Leonardo , Culman Steven W. , Liang Chao , Ruark Matthew D.
Published: February 2022

Significance

Soil organic carbon (C) responses to agricultural management are highly uncertain, hindering our ability to assess the C sequestration potential of croplands and develop sound policies to mitigate climate change while enhancing other ecosystem services. Combining experimental evidence from a long-term field experiment and a meta-analysis of published literature, we show that the accrual of mineral-associated soil C in intensively managed Mollisols was only achieved by managing ruminant grazing on perennial grasslands. Although modifying dominant grain-based systems with reduced tillage, diversified rotations, and legumes and manure additions improve soil health metrics—which is critical to soil, nutrient, and water conservation—they are unlikely to enhance persistent forms of soil C in Mollisols to help drawdown atmospheric C and stabilize climate.
Modelling climate change impacts on maize
Authors: Chisanga Charles Bwalya , Moombe Miyanda , Elijah Phiri
Published: February 2022

Numerous modelling efforts have focused on maize as it is an important cereal crop for both human consumption and livestock production. Crop simulation and multi-linear regressions models can be used to quantify the likely potential impacts of climate change on maize growth and yield. Such models include AquaCrop, Agricultural Production Systems Simulator (APSIM), Decision Support System for Agro-technology Transfer (DSSAT), EPIC, CropSyst, Root Zone Water Quality Model (RZWQM2), SARRA-H, IMPACT+DSSAT, DSSAT, ALAMANC, WOFOST, ADEL, GEPIC, Empirical, MOS, GLAM-Maize, InfoCrop and EcoCrop, among others. Models give predictions utilizing meteorological, soil and crop data in numerical simulations. Various sources of climatic data are available including government meteorological and research departments, world organizations and private institutions. Climate data can also be generated using statistical and dynamical downscaling tools. The review showed that future maize growth and yield would be affected by changes in precipitation, temperature and soil fertility. Rise in temperature is the major factor altering maize yield. Nevertheless, crop simulation models have been observed to give mixed results depending on the region and the crop. Sources of uncertainty in predictions have been attributed to challenges in model parameterization, calibration and validation.
Malaise and remedy of binary boson-star initial data
Authors: Helfer Thomas , Sperhake Ulrich , Croft Robin , Radia Miren , Ge Bo-Xuan , Lim Eugene A
Published: February 2022

Through numerical simulations of boson-star head-on collisions, we explore the quality of binary initial data obtained from the superposition of single-star spacetimes. Our results demonstrate that evolutions starting from a plain superposition of individual boosted boson-star spacetimes are vulnerable to significant unphysical artefacts. For equal-mass binaries, these difficulties can be overcome with a simple modification of the initial data suggested in Helferet al(2019Phys. Rev. D99044046) for collisions of oscillations. While we specifically consider massive complex scalar field boson star models of very high and low compactness, we conjecture that this vulnerability be also present in other kinds of exotic compact systems and hence needs to be addressed.
Topological classifications of quadratic bosonic excitations in closed and open systems with examples
Authors: He Yan , Chien Chih-Chun
Published: February 2022

The topological classifications of quadratic bosonic systems according to the symmetries of the dynamic matrices from the equations of motion of closed systems and the effective Hamiltonians from the Lindblad equations of open systems are analyzed. While the non-Hermitian dynamic matrix and effective Hamiltonian both lead to a ten-fold way table, the system-reservoir coupling may cause a system with or without coupling to a reservoir to fall into different classes. A 2D Chern insulator is shown to be insensitive to the different classifications. In contrast, we present a 1D bosonic Su–Schrieffer–Heeger model with chiral symmetry and a 2D bosonic topological insulator with time-reversal symmetry to show the corresponding open systems may fall into different classes if the Lindblad operators break the symmetry.
Modeling and robust decentralized control system design for plasma current and position in Damavand tokamak
Authors: Fatahi Masoome , Moaveni Bijan , Zandi Hassan , Rasouli Hossein
Published: February 2022

This paper presents a linear dynamic model for the current and position of plasma in Damavand tokamak (DT) based on the RZIP methodology. Experimental data shots of DT are employed to validate the model and to show its accuracy. Since there are uncertainties in the model parameters, a robust decentralized control system is designed by considering the interaction between the input-output channels. Robust proportional and proportional-integral controllers are designed to obtain robust closed-loop stability and performance based on the Kharitonov theorem. The simulation results of the closed-loop system in two scenarios are presented to show the effectiveness of the introduced control system.
Magnetic interaction between soft and hard ferrimagnetic phases in BaFe12O19 + CuFe2O4 composite
Authors: Manglam Murli Kumar , Kumari Suman , Mallick Jyotirekha , Shukla Anant , Kar Manoranjan
Published: February 2022

Magnetic behavior of

B
a
F

e

12

O

19

+

(
x
)

C
u
F

e

2

O

4

(with x = 1, 2, and 4) has been explored. These composites were prepared by the standard sol-gel route. X-ray diffraction, Field Emission Scanning Electron Microscopy, and Transmission Electron Microscopy techniques were employed to characterize the composites. The magnetic interaction between

C
u
F

e

2

O

4

and

B
a
F

e

12

O

19

particles in the composite has been studied by recording the M–H hysteresis loops by employing the Vibrating Sample Magnetometer technique. The role of copper ferrite in the

B
a
F

e

12

O

19

+
C
u
F

e

2

O

4

composite has been explored. It is interesting to note that the

B
a
F

e

12

O

19

+
C
u
F

e

2

O

4

(i.e. x =1) composite shows the maximum magnetic parameters (M

s

, H

c

, and (BH)
max) among all the composite samples under study. Hence, this composition has been investigated extensively by annealing at different temperatures to optimize its magnetic properties. The

B
a
F

e

12

O

19

 + 

C
u
F

e

2

O

4

composite annealed at 1000 oC exhibits the maximum energy product (BH)
max and saturation magnetization (M

s
). The magnetic interaction between two different magnetic phases in the composite has been explored by using the Henkel plot study with the help of isothermal remanent magnetization (IRM) and direct current demagnetization (DCD) M–H curves. The exchange coupling between soft and hard magnetic phases in the composite is also examined by the derivative of magnetization with the magnetic field.
Dirac partial wave calculation for electron scattering cross section by nucleic acid bases
Authors: Ashouri Marjan , Hajivaliei Mahdi , Gholami Nasim
Published: February 2022

Differential, total, elastic and inelastic scattering cross sections due to the electron impact on the primary nucleic acid bases, are calculated with relativistic Dirac partial-wave considering a local interaction potential known as spherical complex optical potential model. The electron scattering is modeled by implementing screening-corrected additivity rule, a modified form of independent atom model, over an energy range of 10–20000 eV. Comparisons of results obtained in this work with other theoretical and experimental approaches are also presented.
Cosmological implications of axion-matter couplings
Authors: Green Daniel , Guo Yi , Wallisch Benjamin
Published: February 2022

Axions and other light particles appear ubiquitously in
physics beyond the Standard Model, with a variety of possible
couplings to ordinary matter. Cosmology offers a unique probe of
these particles as they can thermalize in the hot environment of the
early universe for any such coupling. For sub-MeV particles, their
entropy must leave a measurable cosmological signal, usually via the
effective number of relativistic particles, N
eff. In this paper,
we will revisit the cosmological constraints on the couplings of
axions and other pseudo-Nambu-Goldstone bosons to Standard Model
fermions from thermalization below the electroweak scale, where
these couplings are marginal and give contributions to the radiation
density of ΔN
eff > 0.027. We update the calculation of the
production rates to eliminate unnecessary approximations and find
that the cosmological bounds on these interactions are complementary
to astrophysical constraints, e.g. from supernova SN 1987A. We
additionally provide quantitative explanations for these bounds and
their relationship.
4D Einstein-Gauss-Bonnet gravity from non-Einsteinian phase
Authors: Sengupta Sandipan
Published: February 2022

We set up an Einstein-Gauss-Bonnet theory in four
dimensions, based on the recent formulation of pure gravity with
extra dimensions of vanishing metrical length [1]. In
absence of torsion, the effective field equations depend only on the
four-metric, reflecting a quadratic curvature nonlinearity but no
higher than second order derivatives. In contrast with recent
proposals to obtain 4dEGB theories through a singular rescaling of
the Gauss-Bonnet coupling, this formalism requires no (classical)
regularization of divergences and is inequivalent to Horndeski
gravity, while being generally covariant and independent of
compactification. Notably, the vacuum field equations admit FLRW
cosmologies containing nonsingular bounce and self-accelerating
Universe, and spherically symmetric black holes
more general than
Schwarzschild.
The quadratic theory of gravity emerging here is shown
to
be preserved against the inclusion of higher Lovelock densities in
5+2n dimensions.
Anderson localization of a spin–orbit coupled Bose–Einstein condensate in disorder potential
Authors: Zhang Huan , Liu Sheng , Zhang Yongsheng
Published: February 2022

We present numerical results of a one-dimensional spin–orbit coupled Bose–Einstein condensate expanding in a speckle disorder potential by employing the Gross–Pitaevskii equation. Localization properties of a spin–orbit coupled Bose–Einstein condensate in zero-momentum phase, magnetic phase and stripe phase are studied. It is found that the localizing behavior in the zero-momentum phase is similar to the normal Bose–Einstein condensate. Moreover, in both magnetic phase and stripe phase, the localization length changes non-monotonically as the fitting interval increases. In magnetic phases, the Bose–Einstein condensate will experience spin relaxation in disorder potential.
Temperature and strain sensitivities of surface and hybrid acoustic wave Brillouin scattering in optical microfibers
Authors: Liu Yi , Gu Yuanqi , Ning Yu , Chen Pengfei , Yao Yao , You Yajun , He Wenjun , Chou Xiujian
Published: February 2022

Temperature and strain sensitivities of surface acoustic wave (SAW) and hybrid acoustic wave (HAW) Brillouin scattering (BS) in 1 μm–1.3 μm diameter optical microfibers are simulated. In contrast to stimulated Brillouin scattering (SBS) from bulk acoustic wave in standard optical fiber, SAW and HAW BS, due to SAWs and HAWs induced by the coupling of longitudinal and shear waves and propagating along the surface and core of microfiber respectively, facilitate innovative detection in optical microfibers sensing. The highest temperature and strain sensitivities of the hybrid acoustic modes (HAMs) are 1.082 MHz/°C and 0.0289 MHz/με, respectively, which is suitable for microfiber sensing application of high temperature and strain resolutions. Meanwhile, the temperature and strain sensitivities of the SAMs are less affected by fiber diameter changes, ranging from 0.05 MHz/°C/μm to 0.25 MHz/°C/μm and 1 × 10−4 MHz/με/μm to 5 × 10−4 MHz/με/μm, respectively. It can be found that that SAW BS for temperature and strain sensing would put less stress on manufacturing constraints for optical microfibers. Besides, the simultaneous sensing of temperature and strain can be realized by SAW and HAW BS, with temperature and strain errors as low as 0.30 °C–0.34 °C and 14.47 με–16.25 με.
Enhanced cold mercury atom production with two-dimensional magneto-optical trap
Authors: Zhang Ye , Liu Qi-Xin , Sun Jian-Fang , Xu Zhen , Wang Yu-Zhu
Published: February 2022

A cold atom source is important for quantum metrology and precision measurement. To reduce the quantum projection noise limit in optical lattice clock, one can increase the number of cold atoms and reduce the dead time by enhancing the loading rate. In this work, we realize an enhanced cold mercury atom source based on a two-dimensional (2D) magneto-optical trap (MOT). The vacuum system is composed of two titanium chambers connected with a differential pumping tube. Two stable cooling laser systems are adopted for the 2D-MOT and the three-dimensional (3D)-MOT, respectively. Using an optimized 2D-MOT and push beam, about 1.3×106 atoms, which are almost an order of magnitude higher than using a pure 3D-MOT, are loaded into the 3D-MOT for 202Hg atoms. This enhanced cold mercury atom source is helpful in increasing the frequency stability of a neutral mercury lattice clock.
Simulating the resonance-mediated (1 + 2)-three-photon absorption enhancement in Pr3+ ions by a rectangle phase modulation
Authors: Cheng Wenjing , Li Yuan , Qiao Hongzhen , Wang Meng , Ma Shaoshuo , Shu Fangjie , Xie Chuanqi , Liang Guo
Published: February 2022

Enhancing the upconversion luminescence of rare earth ions is crucial for their applications in the laser sources, fiber optic communications, color displays, biolabeling, and biomedical sensors. In this paper, we theoretically study the resonance-mediated (1 + 2)-three-photon absorption in Pr3+ ions by a rectangle phase modulation. The results show that the resonance-mediated (1 + 2)-three-photon absorption can be effectively enhanced by properly designing the depth and width of the rectangle phase modulation, which can be attributed to the constructive interference between on-resonant and near-resonant three-photon excitation pathways. Further, the enhancement efficiency of resonance-mediated (1 + 2)-three-photon absorption can be affected by the pulse width (or spectral bandwidth) of femtosecond laser field, final state transition frequency, and absorption bandwidths. This research can provide a clear physical picture for understanding and controlling the multi-photon absorption in rare-earth ions, and also can provide theoretical guidance for improving the up-conversion luminescence.