bluuebunny/crossref_metadata_2025 huggingface dataset:
New concepts for molecular magnets
Authors: Pilawa Bernd
Published: April 2022

Miller and Epstein (1994) define molecular magnets as magnetic materials which are prepared by the low‐temperature methods of the preparative chemistry. This definition includes molecular crystals of neutral radicals, radical salts and charge transfer complexes as well as metal complexes and polymers with unpaired spins (Dormann 1995). The challenge of molecular magnets consists in tailoring magnetic properties by specific modifications of the molecular units. The combination of magnetism with mechanical or electrical properties of molecular compounds promise materials of high technical interest (Gatteschi 1994a and 1994b, Möhwald 1996) and both the chemical synthesis of new molecular materials with magnetic properties as well as the physical investigation and explanation of these properties is important, in order to achieve any progress. This work deals with the physical characterization of the magnetic properties of molecular materials. It is organized as follows. In the first part molecular crystals of neutral radicals are studied. After briefly discussing the general magnetic properties of these materials and after an overview over the physical principles of exchange interaction between organic radicals I focus on the interplay between the crystallographic structure and the magnetic properties of various derivatives of the verdazyl and nitronyl nitroxide radicals. The magnetic properties of metal complexes are the subject of the second part. After an overview over the experimental and theoretical tools which are used for the investigation of the magnetic properties I shortly discuss the exchange coupling of transition metal ions and the magnetic properties of complexes of two and three metal ions. Special emphasis is given to spin cluster compounds. Spin cluster denote complexes of many magnetic ions. They are attractive as building blocks of molecular magnets as well as magnetic model compounds for the study of spin frustration, molecular super‐paramagnetism and quasi one‐dimensional magnets.
Perturbative gauge invariance: the electroweak theory
Authors: Dütsch Michael , Schaf Günter
Published: April 2022

The concept of perturbative gauge invariance formulated exclusively by means of asymptotic fields is generalized to massive gauge fields. Applying it to the electroweak theory leads to a complete fixing of couplings of scalar and ghost fields and of the coupling to leptons, in agreement with the standard theory. The W/Z mass ratio is also determined, as well as the chiral character of the fermions. We start directly with massive gauge fields and leptons and, nevertheless, obtain a theory which satisfies perturbative gauge invariance.
Perturbative gauge invariance: electroweak theory II
Authors: Aste Andreas , Schaf Günter , Dütsch Michael
Published: April 2022

A recent construction of the electroweak theory, based on perturbative quantum gauge invariance alone, is extended to the case of more generations of fermions with arbitrary mixing. The conditions implied by second order gauge invariance lead to an isolated solution for the fermionic couplings in agreement with the standard model. Third order gauge invariance determines the Higgs potential. The resulting massive gauge theory is manifestly gauge invariant, after construction.
Numerical study on Anderson transitions in three‐dimensional disordered systems in random magnetic fields
Authors: Kawarabayashi Tohru , Kramer Bernhard , Ohtsuki Tomi
Published: April 2022

The Anderson transitions in a random magnetic field in three dimensions are investigated numerically. The critical behavior near the transition point is analyzed in detail by means of the transfer matrix method with high accuracy for systems both with and without an additional random scalar potential. We find the critical exponent ν for the localization length to be 1.45 ± 0.09 with a strong random scalar potential. Without it, the exponent is smaller but increases with the system sizes and extrapolates to the above value within the error bars. These results support the conventional classification of universality classes due to symmetry. Fractal dimensionality of the wave function at the critical point is also estimated by the equation‐of‐motion method.
Theoretical approaches to the metal‐insulator transition in 2D
Authors: Abrahams Elihu
Published: April 2022

Recent experiments on the two‐dimensional electron gas in various semiconductor structures have revealed the existence of what appears to be a continuous low‐temperature metal‐insulator transition as the electron density is varied, although it was previously commonly accepted that all electronic states will be localized in a two‐dimensional disordered medium. Theoretical proposals for the explanation of various aspects of the experiments will be reviewed and implications for the scaling theory of localization will be discussed.
Disorder induced ferromagnetism
Authors: Eisenberg E. , Berkovits R.
Published: April 2022

We study the in uence of on‐site disorder on the magnetic properties of the ground state for restricted geometries. We find that for two dimensional systems disorder enhances the spin polarization of the system. The tendency of disorder to enhance magnetism in the ground state may be relevant to recent experimental observations of spin polarized ground states in quantum dots.
Does a magnetic field suppress the Coulomb gap?
Authors: Sandow B. , Gloos K. , Rentzsch R. , Ionov A.N. , Schirmacher W.
Published: April 2022

We used electron‐tunnelling spectroscopy to investigate the Coulomb correlation in n ‐ type Germanium. The dopant concentration was smaller than the critical concentration for the metal‐insulator (Anderson) transition. The tunnelling conductance, which probes the electronic density of states, was found to depend strongly on both voltage and temperature. At low temperatures it shows a conductance minimum at the Fermi energy as expected for the Coulomb correlation gap. Applying a magnetic field up to B = 4T at T = 0.1 K reduces the magnitude of the tunneling conductance, but does not significantly change the shape of the spectra. At higher fields, the conductance minimum disappears, suggesting a suppression of the Coulomb gap. This could be due to the field‐induced confinement of the electron wave functions, that strongly reduces the overlap between the localized electron states.
Propagation and localisation of vibrational modes in 3–dimensional disordered systems: the binary force constant model
Authors: Schirmacher W. , Diezemann G.
Published: April 2022

We consider a system of coupled harmonic oscillators on a cubic lattice. The force constants are supposed to take two distinct values at random according to a bond concentration x. The density of states (DOS) is evaluated both by numerical diagonalisation and in coherent‐potential approximation (CPA). There is excellent agreement between the results of the two methods. Near the concentration, where the bonds with the larger force constants percolate, the DOS differs appreciably from the crystalline one and is anomalously enhanced at low frequencies as compared to Debye's ω2 law (“boson peak”). These features are shared with models with continuous distributions of force constants. The mean free path near the strongest anomaly is comparable to the wavelength of the excitations. However, the level distance statistics reveils that the corresponding states are delocalised.
Global and local level dynamics in chaotic microwave billiards
Authors: Barth M. , Kuhl U. , Stöckmann H.‐J.
Published: April 2022

The spectra of Sinai microwave billiards and rectangular billiards with statistically distributed circular scatterers have been taken as a function of the position of one wall, and of one of the scatterers, respectively. Whereas in the first case the velocity distribution and correlations obey the universal behaviour predicted by Simons and Altshuler, in the second case a completely different behaviour is observed. This is due to the fact that a shift of one wall changes the wave function globally whereas the displacement of one scatterer only leads to a local perturbance.
Coulomb blockade and transport spectroscopy in short Si:MOSFET
Authors: Sanquer M. , Specht M. , Ghenim L. , Deleonibus S. , Guegan G.
Published: April 2022

We report Coulomb oscillations in short (50 nm and 100 nm) and wide Silicon MOSFETs at very low temperature, when the source‐drain conductance is below the quantum e2/h. the geometry is dual of a wire, where such oscillations have been previously reported. Our observations show that the dominating best conducting channel is a localized state which can accomodate several electrons. This emphasizes that Coulomb blockade appears also at low temperature in a standart short and wide transistor‐like geometry, without intentional confinement, as far as the conductance is below the quantum.

Analysis of the non‐linear transport permits to evaluate both the mean one electron spacing (few kelvins) and the Coulomb energy (few tens of kelvins). At finite transport voltage the contributions of excited states are observed. Comparing the 50 nm and 100 nm series, we find that the size of the impurity quantum dot roughly scales with the source‐drain distance.
Sulfur in Dynamic Covalent Chemistry
Authors: Orrillo A. Gastón , Furlan Ricardo L. E.
Published: April 2022

Sulfur has been important in dynamic covalent chemistry (DCC) since the beginning of the field. Mainly as part of disulfides and thioesters, dynamic sulfur‐based bonds (DSBs) have a leading role in several remarkable reactions. Part of this success is due to the almost ideal properties of DSBs for the preparation of dynamic covalent systems, including high reactivity and good reversibility under mild aqueous conditions, the possibility of exploiting supramolecular interactions, access to isolable structures, and easy experimental control to turn the reaction on/off. DCC is currently witnessing an increase in the importance of DSBs. The chemical flexibility offered by DSBs opens the door to multiple applications. This Review presents an overview of all the DSBs used in DCC, their applications, and remarks on the interesting properties that they confer on dynamic chemical systems, especially those containing several DSBs.
Electrochemical performance of asymmetric device using the nickel–zinc organometallic structure
Authors: Zeng Jie , Devarayapalli Kamakshaiah Charyulu , Li Changping , Vattikuti S. V. Prabhakar , Shim Jaesool
Published: April 2022

Bimetallic metal–organic frameworks (BMOFs) have developed as novel candidates for electrodes due to their high‐performance energy storage applications. We attempted to develop a new three‐dimensional (3D) ordered structure of nickel–zinc MOFs (NZMOF), grown in situ on carbon cloth (NZMOF/CC) using a solvo‐hydrothermal strategy to increase the stored energy. A notable capacitance of 456.8 F/g was achieved for this electrode at 1 A/g. In addition, the NZMOF/CC//AC/CC assembled split‐cell asymmetric supercapacitor device (SASD) achieved an excellent energy and power densities of 38.54 Wh/kg and 750 W/kg, respectively, with a capacity retention of 87.27% after 5000 cycles, which is better than that of conventional supercapacitors. Additionally, this study is easy and controllable, providing a viable approach for fabricating hybrid electrode materials for high‐performance energy storage systems.
Membrane extraction of V(V) by an oleic acid plasticized poly(vinyl chloride)/Aliquat® 336 polymer inclusion membrane
Authors: Bahrami Salar , Dolatyari Leila , Shayani‐Jam Hassan , Yaftian Mohammad Reza
Published: April 2022

Polymer inclusion membranes (PIMs) have received much attention as a greener method than other liquid membranes for the separation of a great number of chemical species. The expected horizon of industrial applications besides the advantages of greener characteristics of PIMs than other liquid membranes and solvent extraction methods, have resulted in development of the new PIMs for specific tasks. In the presented study, a PIM composed of polyvinyl chloride, Aliquat® 336, and oleic acid (50/40/10 wt%, respectively) is fabricated and its characteristics are studied. Membrane segments (3.5 cm diameter, 0.110 ± 0.013 g) can extract 73% of V(V) (initial concentration 50 mg L−1) from 50 ml Na2SO4 solution (0.1 M) adjusted to pH 2.5 after 8 h shaking. The extraction is proceeded by an anion exchange mechanism in which chloride anion of the extractant is replaced by VO2SO4−. It is approved that ~97% of the extracted amount of V(V) is back‐extracted from the loaded PIMs by contacting them, for 24 h, with 50 ml 7 mol L−1 H2SO4/0.25 v/v% of H2O2. The PIM extracts selectively V(V) from the simulated solutions like that obtained by digestion of spent alumina hydrodesulfurization catalysts.
Atmospheric pressure plasma treatment for enhancing the conducting properties of polypyrrole coated nylon fabric
Authors: Deogaonkar‐Baride Smita , Palaskar Shital S.
Published: April 2022

The present study describes a method for plasma‐assisted in situ chemical polymerization of polypyrrole on nylon‐66 fabric to improve adhesion and conductivity of the polypyrrole coating. Plasma generated from various gas mixtures in dielectric barrier discharge were used to modify the surface of nylon‐66 fabric and investigated the influence of plasma on surface chemistry and morphology of nylon‐66 fabric. Polypyrrole was then deposited over this plasma pretreated nylon fabric by using oxidative chemical polymerization to get electrically conducting nylon fabric. Surface physical and chemical changes of plasma treated nylon‐66 fabric were studied by scanning electron microscopy (SEM), wettability, attenuated total reflection‐Fourier transform infrared spectroscopy (ATR‐FTIR) and X‐ray photoelectron spectroscopy (XPS). Effect of the plasma treatment on binding strength was analyzed by studying abrasion resistance and surface resistivity. Results showed that the strongest interfacial bonding and high conductivity were achieved for He+O2 plasma pretreated PPy coated nylon‐66 fabric. Surface functional groups such as CO, COH, COOH, and CONH were detected on plasma treated nylon‐66 fabric by XPS. These surface functional groups are responsible for the improved adhesion and conductivity of PPY coating on nylon fabric by 35% (up to 2500 abrasion cycles) and 50%, respectively.
Synergistically enhanced performance of epoxy resin by block copolymer and multi‐walled carbon nanotubes
Authors: Zhang Wei , Cui Huanan , Lv Yadong , Yang Qi , Huang Yajiang , Li Guangxian , Kong Miqiu
Published: April 2022

This work aims to investigate the performance of the epoxy resin modified by poly(ethylene glycol)‐b‐poly(propylene glycol)‐b‐poly(ethylene glycol) (PEO‐PPO‐PEO) block copolymers and multi‐walled carbon nanotubes (MWCNTs). It is detected that when PEO‐PPO‐PEO block copolymers and MWCNTs are simultaneously added, synergistic toughening effects for epoxy resin achieve without loss of other properties. Specifically, with the introduction of 5 wt% PEO‐PPO‐PEO block copolymers, the critical stress intensity factor (KIc) of the epoxy resin is increased by 65.7% in contrast with the pure epoxy resin by the reason of the epoxy matrix shear yielding triggered by cavitation of PEO‐PPO‐PEO nanophases and by 28.7% with the introduction of 0.25 wt% MWCNTs owing to the pull‐out and crack bridging of MWCNTs, but other properties are decreased. However, with the simultaneous introduction of 5 wt% PEO‐PPO‐PEO and 0.25 wt% MWCNTs, the KIc of epoxy resins is significantly increased by 97.3%, exhibiting much higher than the linear superposition of the corresponding epoxy resin/PEO‐PPO‐PEO and epoxy resin/MWCNTs composites. Meanwhile, the decrease in other properties is retarded. This is because PEO‐PPO‐PEO block copolymer can enhance the interactions between MWCNTs and epoxy resins in the epoxy resin/PEO‐PPO‐PEO/MWCNT composites, thereby promoting the dispersion of MWCNTs in the epoxy resins. Consequently, the fracture toughness of epoxy resins is efficiently boosted by the superposition of the pull‐out and crack bridging of well‐dispersed MWCNTs and the epoxy matrix shear yielding triggered by the strengthened interactions between PEO‐PPO‐PEO block copolymers and MWCNTs. This work supplies an easy and efficient means to solve the dispersion of nanoparticles, which can prominently advance the comprehensive properties of epoxy resins.
Slippery customers for conservation: Distribution and decline of anguillid eels in South Africa
Authors: Hanzen Céline C. , Lucas Martyn C. , Weyl Olaf L.F. , Marr Sean M. , O’Brien Gordon , Downs Colleen T.
Published: April 2022

Four anguillid eel species occur in the western Indian Ocean rivers of Africa: Anguilla bengalensis, Anguilla bicolor, Anguilla marmorata and Anguilla mossambica. These catadromous fishes face multiple stressors, including habitat alteration and deterioration, barriers to migration, pollution and the adverse impacts of alien species, but knowledge of eel species occurrence, abundance and ecology in Africa remains poor.

This study investigated the present and historical distribution of anguillid eels and the potential associated drivers of declines at the southern extremities of their ranges in South Africa. Data analysed included sampling conducted in KwaZulu–Natal and Eastern Cape between 2015 and 2020, and secondary data extracted from databases, museums and local management agencies.

The median extent of inland penetration increased as follows: 22 km for A. bicolor, 29 km for A. marmorata, 94 km for A. bengalensis and 293 km for A. mossambica. The median altitude followed a similar pattern.

Extent of occurrence analyses were carried out at the regional level in KwaZulu–Natal. The sampling data on present distribution (2015–2020), compared with historical data, suggests declines in the extents of occurrence of the four eel species in KwaZulu–Natal, ranging between 31 and 48% in the last 30 years and between 35 and 82% since the 1950s.

With increasing human threats in the region, especially from watercourse modification and water abstraction, further declines for these species are expected. Conservation measures recommended include the maintenance or restoration of the ecological connectivity of important rivers and the implementation of freshwater protected areas. Although eels are at present not widely exploited in South Africa, there is a need for fisheries regulations to manage sustainable commercial exploitation.
Data‐driven dual‐rate cascade control and application to pitch angle control of UAV
Authors: Sakai Yuta , Kawaguchi Natsuki , Sato Takao , Arrieta Orlando
Published: April 2022

A data‐driven design method for a cascade control system is proposed. The cascade control system consists of inner and outer loops, where the control interval of the outer loop is an integer multiple of the inner loop; hence, the system is a dual‐rate system. In the proposed method, controllers in the inner and outer loops are designed based on one‐shot data. In such a dual‐rate cascade system, since the controllers are designed using different data‐rate signals, the lifting technique is applied to align the dual‐rate data. To show its effectiveness, the proposed method is compared with a conventional single‐rate cascade control method, and numerical simulations and experiments are presented to examine servo and regulation performance.
Biolabel‐led research pattern reveals serum profile in rats after treatment with Herba Lysimachiae: Combined analysis of metabonomics and proteomics
Authors: Li Xu‐zhao , Liu Qi , Zhang Shuai‐nan , Yang Wu‐de , Zhou Ying
Published: April 2022

In traditional Chinese medicine, Herba Lysimachiae (HL) is mainly used to treat rheumatic arthralgia. Current pharmacological studies also showed that HL has therapeutic potential for synovial diseases. HL is an oral drug, whose compounds need to enter the blood circulation before reaching the injured tissue, thus potentially causing activity or toxicity to the blood system. In this study, the biolabel‐led research pattern was used to analyze the serum profile after HL intervention, based on which the safety and efficacy of HL were explored. Metabonomics and proteomics were combined to analyze the biolabels responsible for the interventions of HL in serum. Bioinformatics databases were used to screen for the material basis that may interfere with biolabels. Omics analysis showed that differentially expressed proteins (19) and metabolites (5) were identified and considered as the potential biolabels, which were involved in 8 biochemical processes (platelet activation and aggregation, blood glucose release, immune and inflammatory regulation, oxidative stress, endoplasmic reticulum stress, tumor progression, blood pressure regulation, and uric acid synthesis). Thirty‐one compounds may be the material basis to interfere with 11 biolabels. The present research reveals that the potential activities and toxicities of HL can be explored based on the biolabel‐led research pattern.
Industrial energy consumption and pollutant emissions: Combined decomposition of relative performance and absolute changes
Authors: Liu Sicen , Chen Xiaodong , Shen Zhiyang , Baležentis Tomas
Published: April 2022

Combined decomposition of relative productivity growth and absolute changes in input/output variables helps to identify the driving forces of energy conservation and emission reduction. This paper proposes a framework based on the Luenberger productivity indicator (LPI) and the logarithmic mean Divisia index (LMDI) approach to analyze the energy–economy–environment nexus. The empirical case of the China's industrial sector for 2006–2014 is analyzed. Following this approach, we present a variable‐specific decomposition framework which attributes the overall productivity change and its sources to individual input/output variables. Empirically, we examine the relationships between the productivity growth and energy consumption within the LPI–LMDI framework across China's province‐level regions. The results show important spatial variation in the productivity measures. The LPI–LMDI decomposition implies that the industrial energy consumption increased with productivity growth appearing as the only mitigating factor. As regards the industrial SO2 emission, the individual productivity growth effect and the efficiency change effect remained as suppressing factors for emission abatement. These results can be used for evidence‐based decision making.
A three‐dimensional analysis of the development of cranial nerves in human embryos
Authors: Smit Johannes A. , Jacobs Karl , Bais Babette , Meijer Berrie , Seinen Marjolein N. , de Bree Karel , Veldhuis Tyas , Hagoort Jaco , de Jong Kees H. , Breugem Corstiaan C. , Oostra Roelof‐Jan , de Bakker Bernadette S.
Published: April 2022

To increase our understanding of the etiology of specific neurological disorders (e.g., Duane syndrome, glossoptosis in Pierre Robin sequence), proper knowledge of anatomy and embryology of cranial nerves is necessary. We investigated cranial nerve development, studied histological sections of human embryos, and quantitatively analyzed the 3D reconstructions. A total of 28 sectioned and histologically stained human embryos (Carnegie stage [CS] 10 to 23 [21–60 days of development]) were completely digitalized by manual annotation using Amira software. Two specimens per stage were analyzed. Moreover, quantitative volume measurements were performed to assess relative growth of the cranial nerves. A chronologic overview of the morphologic development of each of the 12 cranial nerves, from neural tube to target organ, was provided. Most cranial nerves start developing at CS 12 to 13 (26–32 days of development) and will reach their target organ in stage 17 to 18 (41–46 days). In comparison to the rest of the developing brain, a trend could be identified in which relative growth of the cranial nerves increases at early stages, peaks at CS 17 and slowly decreases afterwards. The development of cranial nerves in human embryos is presented in a comprehensive 3D fashion. An interactive 3D‐PDF is provided to illuminate the development of the cranial nerves in human embryos for educational purposes. This is the first time that volume measurements of cranial nerves in the human embryonic period have been presented.
Prevalence and determinants of caregivers’ self‐reported child abuse among children aged 3–6 years in the south of Iran
Authors: Fatemi Mohammad Javad , Afrashteh Sima , Zahmatkesh Soraya , Hemmati Abdolrasool , Fararouei Mohammad
Published: April 2022

Child abuse is a problem that needs to be addressed worldwide. This is a cross‐sectional study to estimate the prevalence of child abuse among children aged 3 to 6 years and its associated factors in southern Iran. In total, 5142 participants were selected using multi‐stage random sampling. The estimated prevalence rates of neglect and physical and verbal/emotional abuse among children were 26.4% (95% confidence interval [CI] 25.2–27.6), 59.4% (95% CI 58.1–60.6), and 63.9% (95% CI 62.6–65.1), respectively. The results of logistic regression models showed that the child's sex was associated with physical abuse (odds ratio [OR]boy/girl 1.25; 95% CI1.11–1.41) and verbal abuse (ORboy/girl 1.17; 95% CI 1.04–1.32). However, parents living together was inversely associated with physical abuse (OR 0.45; 95% CI 0.25–0.80), verbal abuse (ORboy/girl 0.46; 95% CI 0.25–0.84), and neglect (ORboy/girl 0.53; 95% CI 0.31–0.88). Mother's education (ORuniversity degree/illiterate 0.58; 95% CI 0.35–0.98) was also inversely associated with physical abuse. The prevalence of child abuse in southern Iran is significantly higher than in several other countries in the region and other parts of the world. Social and family factors, including mother's education and parents living together, are important in reducing child abuse and its related mental and physical disorders during childhood. It is essential to train parents of young children about abuse and its negative effects on the health and social performance of children.
Irinotecan‐induced severe hypotension in a patient with lung cancer
Authors: Nakano Ryota , Momo Kenji , Matsuzaki Airi , Sakai Akiko , Uchikura Takeshi , Tanaka Katsumi , Numazawa Satoshi , Sasaki Tadanori
Published: April 2022

Most hypotension during chemotherapy is caused by an allergic mechanism. Conversely, non‐allergic hypotension due to chemotherapy is rare. In this case report, we present a patient who suffered severe hypotension followed by the administration of irinotecan‐based chemotherapy and some supportive care such as steroids for preventing emesis. A 71‐year‐old man with hypertension was diagnosed with stage IV small cell lung cancer (sT1cN3M0). Severe hypotension occurred in the patient after every administration of chemotherapy. Finally, he was able to receive all four courses of chemotherapy as planned along with the medical staff’s support care. This case provides that a regimen that contained irinotecan and steroid could cause hypotension and the mechanism is partially explained by inhibiting choline esterase and adrenal insufficiency. We should be careful about non‐allergic hypotension when we administer irinotecan‐based chemotherapy.
Decolorization of Textile Dyes in a Fixed‐Bed Biofilm Reactor
Authors: Madhushika H. Gimhani , Ariyadasa Thilini U. , Gunawardena Sanja H. P.
Published: April 2022

A fixed‐bed biofilm reactor (FBBR) was developed and its performance in decolorizing synthetic dye mixtures and textile industry effluents was evaluated in both batch and continuous modes. It was observed that yeast extract was important as the carbon source in the FBBR feed for color removal. However, the requirement for yeast extract in FBBR is very small compared to that in suspended cell cultures. Structural changes in dyes due to biological treatment were assessed from ultraviolet‐visible spectral and high‐performance liquid chromatography (HPLC) analyses. Gas chromatography‐mass spectrophotometry (GC‐MS) investigations confirmed that the metabolites formed were nontoxic and benign.
Implementation of irrigation with dairy cattle manure for tropical perennial pastures in Costa Rica
Authors: Herrera‐Muñoz Juan Ignacio , Villalobos‐Villalobos Luis A.
Published: April 2022

Animal manures allow nutrients recycling in cropping systems, while contributing to the fulfillment of environmental standards. Pasture irrigation with animal manures has been fostered for Costa Rican dairy farms over the last 15 yr. A lack of information and training regarding irrigation and management of animal manures has led to the implementation of diverse methods by producers, but those have not yet been characterized. This study aimed to describe the current management of Costa Rican dairy farms irrigating perennial pastures with slurries. The farms were mostly grass‐based systems with supplements fed to cows during the time spent at the milking parlor and/or in feeding stalls through the day. Farms collect manure when facilities are washed with water, which is then stored in plastic tanks or cement structures for less than 1 day before irrigating pastures. The amount of water used by dairy producers was greater than the recommended water/manure ratio (13.4 vs. 4.0 L kg–1), with only one farm reporting values below this ratio. Slurries were sampled and analyzed for their nutrient and microbial content. Both nutrient and microbial content varied in this study due to factors specific to each farm, especially with respect to water management. The variability found in water use among farms and regions (2.4–36.7 L kg–1) may generate unintended consequences from an environmental standpoint. Sustainability of Costa Rican dairy farms can be enhanced if specific guidelines for manure irrigation are developed, which could have benefits for chemical fertilizer use and environmental effect.
Bubble–bitumen detachment in a flowing water channel
Authors: Zhou Joe Z.
Published: April 2022

Effect of water flow velocity (≤3 m/s) on bubbles detaching from bitumen was examined in a water channel at room temperature. The results showed different behaviours of bubble–bitumen detachment for different sizes of bubbles. With increasing water flow speed, a larger bubble (>0.15–0.2 cm) underwent the following steps before detaching from the bitumen layer: deformation; neck formation; the bubble broke up from the neck, with the top portion sheared away, leaving the bottom portion as a small bubble stuck to bitumen; and then, the small bubble detached from the bitumen and was carried away by further increasing water flow. Smaller bubbles (<0.1–0.15 cm) detached from bitumen after deformation without breaking up, with increasing water flow. An empirical correlation between the size of bubbles detaching from bitumen with water flow velocity/shear rate was established. At a flow velocity of 3 m/s, only bubbles smaller than 250–300 μm might be able to stay attached to bitumen, or a shear rate higher than 2500 s−1 is needed to detach a 250–300 μm bubble from bitumen.
Inductive effect and hyperconjugation in radical chain reactions – new learning opportunity to work out key concepts of organic chemistry
Authors: Zimmermann Marc , Domke Dennis , Schween Michael
Published: April 2022

In diesem Beitrag wird eine Lerngelegenheit zur experimentellen Untersuchung von radikalischen Photobromierungsreaktionen vorgestellt. Die Experimente sind als Fallvergleiche konstitutionsisomerer Reaktanten inszeniert und erlauben in der präsentierten Form die Erarbeitung des induktiven Effekts bzw. des Konzepts Hyperkonjugation, die zu den Kernkonzepten der organischen Chemie gehören. Mit unterschiedlichen Beobachtungsmethoden (Verschwinden der Bromfarbe in den Reaktionslösungen sowie Nachweis von pH‐Wert‐Änderungen, Änderungen des elektrischen Leitwerts und Bromid‐Nachweisreaktionen in Testlösungen) eignen sich diese Reaktionen in der Verflechtung von Experiment und Theorie, um grundlegende mechanistische Aspekte radikalischer Substitutionsreaktionen zu untersuchen. Dazu gehören insbesondere die Energetik sowie die Regioselektivität. Zudem sind die Fallvergleiche so angelegt, dass Lernende zwischen relevanten und irrelevanten äußeren Strukturmerkmalen unterscheiden lernen.
Pleomorphic liposarcoma: A clinicopathologic study of 20 FNA cases
Authors: Wakely Paul E. , Wangsiricharoen Sintawat , Ali Syed Z.
Published: April 2022

BACKGROUND

Pleomorphic liposarcoma (PLPS) is the least common but most aggressive of all forms of liposarcoma (LPS). Its diagnosis relies on the recognition of pleomorphic lipoblasts (PLBs), whose numbers vary considerably. Because few large fine‐needle aspiration (FNA) biopsy studies exist, the authors review their experience with PLPS.

METHODS

The authors’ cytopathology files were searched for PLPS with histopathologic verification. FNA biopsy smears were performed via standard techniques.

RESULTS

Twenty cases from 20 patients (male/female ratio, 2.3/1; age range, 22‐77 years; mean age, 58 years) met the inclusion criteria. All had tissue confirmation. Biopsy sites included the following: thigh (11 [55%]), upper extremity (4 [20%]), axilla (2 [10%]), neck (1 [5%]), chest wall (1 [5%]), and mediastinum (1 [5%]). Aspirates were from primary (17 [85%]), locally recurrent (2 [10%]), and metastatic neoplasms (1 [5%]). The FNA diagnoses were PLPS (10 [50%]), myxofibrosarcoma (4 [20%]), LPS (2 [10%]), sarcoma (2 [10%]), and high‐grade malignant neoplasm (2 [10%]). Smears showed thick cell clusters and dissociated single forms. Pleomorphic, epithelioid, and bizarre cell/nuclear shapes were common. PLBs were absent, rare, or unnoticed in 45%. In 25%, smears dominated by myxoid stroma were diagnosed as high‐grade myxofibrosarcoma or myxoid LPS. Ancillary testing performed in 5 cases had limited diagnostic efficacy.

CONCLUSIONS

FNA biopsy of PLPS, although able to successfully recognize malignancy, suffers from a sampling bias due to an inability to capture or recognize PLBs in a significant proportion of cases secondary to the heterogeneous composition of this neoplasm.;
Apprenticeship and the art of making meaning in cytopathology
Authors: Wiles Austin B.
Published: April 2022

The exemplary work of Wakely et al goes beyond the diagnosis of a rare entity. Therein resides an apprenticeship in the art of cytopathology itself: making meaning from specimens.;
Malware detection based on multi‐objective convolution restricted Boltzmann machine model and constraint‐dividing crossover strategy algorithm
Authors: Cui Zhihua , Zhao Yaru , Liu Hao , Wang Ling , Fan Wenhui
Published: April 2022

Malicious code, which is used to threaten network security, has been improved by many methods and strategies. However, the use of unreasonable deep learning models and single‐objective algorithms often affects the accuracy of data classification. Moreover, as an optimization problem, the existence of low‐quality datasets (imbalanced datasets) constrains the training effect of neural network models. Therefore, it is a big challenge to effectively design data processing methods and suitable training models. To enhance the robustness of the model and obtain better data classification results, it is essential to develop an efficient training model and strategy. To resolve this problem, a novel multi‐objective convolution restricted Boltzmann machine (CRBM) model based on the spatial pyramid pooling strategy is proposed to identify images and classify data in this study. Moreover, a fast nondominated sorting genetic algorithm based on the constraint‐dividing crossover strategy (CDCS‐NSGA‐II) is designed to optimize the imbalance datasets of the malware families. Extensive experimental results show that the multi‐objective CRBM model designed in this study combined with the CDCS‐NSGA‐II algorithm can effectively enhance the learning ability of the dataset, increase the effect of data classification and improve the robustness of the model.
Electroless Deposited Nickel Thin Films Alloyed with Thorium
Authors: Schapiro Ilan , Shandalov Michael , Maman Nitzan , Ezersky Vladimir , Golan Yuval , Yahel Eyal
Published: April 2022

Ni thin films alloyed with 232Th are obtained using electroless bath deposition by optimization of solution composition and deposition temperature. X‐ray photoelectron spectroscopy and transmission electron microscopy (TEM) indicate a fairly homogenous distribution of 232Th, with considerable amounts of incorporated oxygen. TEM confirms the presence of crystalline films with low concentrations of nickel phosphide precipitates for both non‐alloyed Ni and Ni─Th films.
Multi‐output, multi‐level, multi‐gate design using non‐linear programming
Authors: Dimopoulos A. C. , Pavlatos C. , Papakonstantinou G.
Published: April 2022

The conventional methodology of logic circuits design is by using logic gates. Thus, most of the minimization algorithms concern a limited set of gates (complete sets), like sum of products, exclusive‐or sum of products, NAND gates, NOR gates, and so forth. In this paper, a method is proposed for minimizing multi‐output Boolean functions using any kind of two‐input gates although it can easily be extended to multi‐input gates. The method is based on non‐linear mixed integer programming. Our methodology was tested against others proposed in the literature showing that it can achieve the same or better results in all cases. The contribution of this work can be summarized in the following: (i) it is the only approach to guarantee minimality to the problem of multi‐output, multi‐level, multi‐gate design, (ii) it is general and flexible and can solve design problems with any predefined gates and gate topology, (iii) it is a novel approach which may be adopted easily to solve other kinds of logic design problems, and (iv) incompletely specified Boolean functions are accepted, in contrary to other methods.
Flow rule‐based routing protocol management system in software‐defined IoT sensor network for IoT applications
Authors: Kumar Karunanithi Praveen , Sivanesan Perumal
Published: April 2022

In this article, a software‐defined (SDN)‐based Internet of things (IoT) sensor network (S‐ISN) architecture is proposed to fulfill the IoT applications in real time. The proposed system's architecture contains three planes, namely, data plane, control plane, and application plane, to enrich SDN in IoT applications. An IoT application‐based SDN controller is designed exclusively with two management rules—IoT application device management and IoT application‐based topology management. IoT application device management engages in controlling the functions of physical devices that lie on the data plane—path formation of the sensor (proactive, reactive, and hybrid) and reporting scheme management (query, time, and event) of the IoT sensor node. Likewise, IoT application topology management facilitates controlling network topology‐related issues using network structure management (data, location, group, and hierarchical) and next‐hop selection management (broadcast, location, and probabilistic) of the IoT sensor network. The above said management policies are achieved in real time to meet the applications of IoT. Hence, this S‐ISN scheme focuses on IoT application‐related issues with great flexibility in real time. Experimental results show that the network metrics have been improved by the proposed approach as compared with existing methods.
Analytical approaches for evaluating passive acoustic monitoring data: A case study of avian vocalizations
Authors: Symes Laurel B. , Kittelberger Kyle D. , Stone Sophia M. , Holmes Richard T. , Jones Jessica S. , Castaneda Ruvalcaba Itzel P. , Webster Michael S. , Ayres Matthew P.
Published: April 2022

The interface between field biology and technology is energizing the collection of vast quantities of environmental data. Passive acoustic monitoring, the use of unattended recording devices to capture environmental sound, is an example where technological advances have facilitated an influx of data that routinely exceeds the capacity for analysis. Computational advances, particularly the integration of machine learning approaches, will support data extraction efforts. However, the analysis and interpretation of these data will require parallel growth in conceptual and technical approaches for data analysis. Here, we use a large hand‐annotated dataset to showcase analysis approaches that will become increasingly useful as datasets grow and data extraction can be partially automated.

We propose and demonstrate seven technical approaches for analyzing bioacoustic data. These include the following: (1) generating species lists and descriptions of vocal variation, (2) assessing how abiotic factors (e.g., rain and wind) impact vocalization rates, (3) testing for differences in community vocalization activity across sites and habitat types, (4) quantifying the phenology of vocal activity, (5) testing for spatiotemporal correlations in vocalizations within species, (6) among species, and (7) using rarefaction analysis to quantify diversity and optimize bioacoustic sampling.

To demonstrate these approaches, we sampled in 2016 and 2018 and used hand annotations of 129,866 bird vocalizations from two forests in New Hampshire, USA, including sites in the Hubbard Brook Experiment Forest where bioacoustic data could be integrated with more than 50 years of observer‐based avian studies. Acoustic monitoring revealed differences in community patterns in vocalization activity between forests of different ages, as well as between nearby similar watersheds. Of numerous environmental variables that were evaluated, background noise was most clearly related to vocalization rates. The songbird community included one cluster of species where vocalization rates declined as ambient noise increased and another cluster where vocalization rates declined over the nesting season. In some common species, the number of vocalizations produced per day was correlated at scales of up to 15 km. Rarefaction analyses showed that adding sampling sites increased species detections more than adding sampling days.

Although our analyses used hand‐annotated data, the methods will extend readily to large‐scale automated detection of vocalization events. Such data are likely to become increasingly available as autonomous recording units become more advanced, affordable, and power efficient. Passive acoustic monitoring with human or automated identification at the species level offers growing potential to complement observer‐based studies of avian ecology.
Chromosome‐level genome assembly for the horned‐gall aphid provides insights into interactions between gall‐making insect and its host plant
Authors: Wei Hong‐Yuan , Ye Yu‐Xuan , Huang Hai‐Jian , Chen Ming‐Shun , Yang Zi‐Xiang , Chen Xiao‐Ming , Zhang Chuan‐Xi
Published: April 2022

The aphid Schlechtendalia chinensis is an economically important insect that can induce horned galls, which are valuable for the medicinal and chemical industries. Up to now, more than twenty aphid genomes have been reported. Most of the sequenced genomes are derived from free‐living aphids. Here, we generated a high‐quality genome assembly from a galling aphid. The final genome assembly is 271.52 Mb, representing one of the smallest sequenced genomes of aphids. The genome assembly is based on contig and scaffold N50 values of the genome sequence are 3.77 Mb and 20.41 Mb, respectively. Nine‐seven percent of the assembled sequences was anchored onto 13 chromosomes. Based on BUSCO analysis, the assembly involved 96.9% of conserved arthropod and 98.5% of the conserved Hemiptera single‐copy orthologous genes. A total of 14,089 protein‐coding genes were predicted. Phylogenetic analysis revealed that S. chinensis diverged from the common ancestor of Eriosoma lanigerum approximately 57 million years ago (MYA). In addition, 35 genes encoding salivary gland proteins showed differentially when S. chinensis forms a gall, suggesting they have potential roles in gall formation and plant defense suppression. Taken together, this high‐quality S. chinensis genome assembly and annotation provide a solid genetic foundation for future research to reveal the mechanism of gall formation and to explore the interaction between aphids and their host plants.
Comparative study on gut microbiota in three Anura frogs from a mountain stream
Authors: Chen Zhuo , Chen Jun‐Qiong , Liu Yao , Zhang Jie , Chen Xiao‐Hong , Qu Yan‐Fu
Published: April 2022

Composition and diversity in gut microbiota are impacted by a wide variety of factors. The similarity of gut microbiota in related or sympatric species has been gaining recent traction. Here, 16S rRNA gene sequencing technology was employed to study the gut microbiota of three sympatric frog species, namely Odorrana tormota, O. graminea, and Amolops wuyiensis. In these three frog species, the most abundant phylum was Proteobacteria, followed by Bacteroidetes, Verrucomicrobia, and Firmicutes. The most abundant family was Burkholderiaceae in three species. The most dominant genera were Burkholderia, Caballeronia, and Paraburkholderia with the highest relative abundance in O. tormota, O. graminea, and A. wuyiensis, respectively. No differences were observed in alpha diversity indexes among the three frog species. However, bacterial similarity of gut microbiota was significantly different between O. tormota and A. wuyiensis and between O. graminea and A. wuyiensis. Metabolism‐related gene function was predominantly enriched in the gut microbiota of the three evaluated frog species. From these findings, that the relative abundance of the gut microbiota and predicted gene functions differed in three species, we conclude that there were significant differences in the gut microbiota of the three species. Similar alpha diversity and interspecific bacterial similarity in the gut might be related to bacterial transmission among the three Anura frogs evaluated in this study.
Phylogeography using mitogenomes: A rare Dipodidae, Sicista betulina, in North‐western Europe
Authors: Andersen Liselotte Wesley , Jacobsen Magnus W. , Frydenberg Jane , Møller Julie Dahl , Jensen Thomas Secher
Published: April 2022

Repeated climatic and vegetation changes during the Pleistocene have shaped biodiversity in Northern Europe including Denmark. The Northern Birch Mouse (Sicista betulina) was one of the first small rodent species to colonize Denmark after the Late Glacial Maximum. This study analyses complete mitochondrial genomes and two nuclear genes of the Northern Birch Mouse to investigate the phylogeographical pattern in North‐western Europe and test whether the species colonized Denmark through several colonization events. The latter was prompt by (i) the present‐day distinct northern and southern Danish distribution and (ii) the subfossil record of Northern Birch Mouse, supporting early Weichselian colonization. Samples from Denmark, Norway, Sweden, Russia, Latvia, Estonia, and Slovakia were included. Mitogenomes were obtained from 54 individuals, all representing unique mitogenomes supporting high genetic variation. Bayesian phylogenetic analysis identified two distinct evolutionary linages in Northern Europe diverging within the Elster glaciation period. The results of the two nuclear genomes showed lower genetic differentiation but supported the same evolutionary history. This suggests an allopatric origin of the clades followed by secondary contact. Individuals from southern Denmark were only found in one clade, while individuals from other areas, including northern Denmark, were represented in both clades. Nevertheless, we found no evidence for repeated colonization's explaining the observed fragmented distribution of the species today. The results indicated that the mitogenome pattern of the Northern Birch Mouse population in southern Denmark was either (i) due to the population being founded from northern Denmark, (ii) a result of climatic and anthropogenic effects reducing population size increasing genetic drift or (iii) caused by sampling bias.