bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dielectric properties of mineral oil‐based nanofluids under temperature variations
Authors: Muangpratoom Pichai , Pattanadech Norasage 
Published: October 2019

The aim of this research is to improve the electrical properties of dielectric liquids. An examination of the dielectric properties of mineral oil‐based nanofluids was carried out, using three different nanoparticle types: titanium dioxide, zinc oxide, and barium titanate, each with a mean diameter not exceeding 100 nm. The test samples were divided into two groups, including mineral oil mixed with nanoparticles at a concentration of 0.01 and 0.03% volume fraction, respectively. Determination of the AC breakdown voltage of the unmodified mineral oil and the nanofluid samples was performed through testing at temperatures varying within the range of 35–90°C in accordance with the standards of IEC 60156. Furthermore, testing was also performed to determine the dielectric dissipation factor (tanδ) for each of the liquid samples according to IEC 60247. From the study, it was shown that the performance of nanofluid was significantly affected by increasing the temperature. It could be observed from the findings that the use of nanoparticles in creating mineral oil‐based nanofluids had potential to bring a number of advantages in terms of dielectric applications.
Novel radar signal to efficiently utilise spectrum based on continuous‐phase frequency‐shift keying
Authors: Jie Zhang , Xuewei Xu , Tao Jiang , Hong Zhang 
Published: October 2019

Aiming at the problem of high side‐band spectrum for a general frequency‐shift keying (FSK) radar signal, this study introduces a novel radar FSK signal based on continuous‐phase frequency‐shift keying (CPFSK) used in communication systems. Theoretical analysis, simulation and physical application results show that the CPFSK radar signal efficiently controls the spectral containment, whose roll‐off performance of the CPFSK is ∼20 dB better than that of normal FSK; meanwhile, the modified signal possesses good ambiguity and pulse compression performances for radar application.
Cognitive HF radar
Authors: Anderson Stuart 
Published: October 2019

Radars operating in the high‐frequency (HF) band can exploit propagation modes other than line‐of‐sight and are hence widely employed to provide over‐the‐horizon surveillance and remote sensing. Most HF radars operating today rely on surface wave propagation; while opportunities for enhancing their performance by adding cognitive features exist, these have not been widely seized. In contrast, designers of HF skywave radars, which exploit ionospheric reflection to achieve ranges in excess of 4000 km, have long sought to counter the enormous challenges of the geophysical environment by implementing schemes to raise radar intelligence quotient (IQ) and autonomy. Measures that have been explored relate to resource allocation, operating procedures, signal processing, target classification and remote sensing. The perception–action cycle constitutes the structural element of these developments, accessing prior knowledge and input from auxiliary sensors, exactly as proposed by those who later coined the term cognitive radar. Here, the roles of cognition in HF skywave radars are reviewed, illustrating the needs and benefits with examples including detection in sea clutter, ionospheric channel compensation and multiple‐input and multiple‐output HF radar.
Design of terahertz frequency scanning reflector antenna and its application in direction‐of‐arrival estimation
Authors: Li Shichao , Hou Peipei , Zhang Pengcheng , Hao Congjing , Qu Jian , Jia Qu , Li Gang , Li Chao 
Published: October 2019

A novel frequency scanning‐based direction‐of‐arrival (DOA) estimation scheme is proposed at terahertz (THz) band. The diffraction enhancement mechanism, focusing the superposition of the diffracted beam radiated from each element in one unit cell, is expanded to the 0.3 THz band. The frequency scanning reflector antenna (FSRA) operating at 235–330 GHz is proposed with high diffraction efficiency. Angular super‐resolution algorithm is proposed based on the FSRA. Maximum likelihood (ML) method, traditionally used in array signal processing, is extended to the novel frequency scanning system based on the FSRA. The model of FSRA manifold vector is constructed. A FSRA operating on 0.3 THz frequency band was experimented, based on which the DOA estimation system is constructed. The resolution of the frequency scanning ML algorithm can be obtained on the level of half of the 3 dB beamwidth by the proof‐of‐principle experiments in 0.3 THz band.
Investigating vertical motion of small insects in atmospheric boundary layer using millimetre‐wavelength radar and Doppler LIDAR
Authors: Wainwright Charlotte E. , Stepanian Phillip M. , Reynolds Don R. , Reynolds Andy M. 
Published: October 2019

It is well known in the meteorological community that millimetre‐wavelength cloud radars contain considerable contamination from aerial biota, and much of this comprises small weakly flying insects. Several methods have been explored for removing insect contamination from cloud radar data yet using this data to study the behaviour of insects remains a relatively unexplored area. Here, the authors describe the use of a collocated Ka‐band cloud radar and Doppler LIDAR to study the vertical motion of small insects and investigate how this varies depending on the surrounding vertical air motion. We find that in the convective boundary layer, insects are largely concentrated in updrafts. During the daytime, small insects in downdrafts are found to descend at an average rate of 0.25 m s−1, yet insects caught in updrafts showed a descent response that was dependent upon the strength of the updraft in which they were embedded. Although the downward motion of the insects increased with increasing updraft strength, it was insufficient to overcome the rising motion in the updraft, i.e. in updrafts the insects ascend but at a slower speed than the surrounding air. We also report an ongoing efforts to extend this research to the nocturnal stable boundary layer.
Radar small/mini target detection technology in strong clutter environment
Authors: Wu Linyong , Mao Jin , Bai Weixiong 
Published: October 2019

A method of radar small/mini target wavelet transform and principal component analysis in strong clutter environment is suggested. Focusing on the situation that the small/mini target in the strong clutter environment is swamped by clutter, traditional constant false‐alarm detection method limited by theory limit cannot effectively detect target, the transform domain, wavelet coefficient and principal component decomposition can realise the separation of radar small/mini target signal from the clutter signal, so as to achieve clutter suppression and small/mini target detection. The test shows the radar small/mini target detection based on wavelet transform is limited by wavelet function, decomposition layers and adaptive threshold; principal component decomposition can adapt to the signal of different radar systems, and types with good adaptability to algorithm can effectively suppress clutter and improve average signal‐to‐noise ratio by 7 dB.
Micro‐vibration distinguishment between humans and animals based on ensemble empirical mode decomposition using ultra‐wide band radar
Authors: Yin Yue , Yu Xiao , Lv Hao , Liu Miao , Qi Fugui , Wang Jianqi 
Published: October 2019

Ultra‐wide band (UWB) bio‐radar attracts lots of researchers, due to its special advantages of non‐contact detection. It is widely used in multiple applications such as medical monitoring, rescue and anti‐terrorism missions nowadays. However, identifying the target after it was detected and located comes to be a more challenging task. The study aims to investigate the differences of the target characteristics between humans and animals based on ensemble empirical mode decomposition analysis and to test whether these differences can be distinguished. Finally, the authors proposed a new method to distinguish between humans and animals with 500 MHz UWB bio‐radar detection system by calculating the energy ratio of micro‐vibration signal in human breathing frequency band. Experimental results demonstrate that the energy ratio can be served as a useful parameter, which is promising to distinguish between humans and rabbits.
Research on aperture‐level simultaneous transmit and receive
Authors: Qiu Jian , Yao Yuan , Wu Guangxin 
Published: October 2019

This study uses adaptive digital beamforming to provide high isolation between a transmitter and a receiver, which proved effective in achieving simultaneous transmit and receive. Uniform linear array is chosen as the research object, and the cost function is constructed by combining the coupling matrix and beam pointing constraints; then the optimal weighted vector is obtained under the linearly constrained minimum variance rule. The method will provide at least 110 dB isolation without affecting the performance of target detection, which provides certain reference significance in engineering.
Performance analysis of one‐step prediction‐based cognitive jamming in jammer‐radar countermeasure model
Authors: Gao Lu , Liu Li , Cao Yang , Wang Shangyue , You Shixun 
Published: October 2019

Strong adaptive radar, such as cognitive radar (CNR), can perform various missions while ensuring its own security in electronic warfare, via detecting environments and changing the radar parameters in real time. Unfortunately, most of the current military countermeasures, such as jamming‐based electronic countermeasures, have rarely been related to jamming for CNR. Since the behaviours of radar in the traditional design of the jammer‐radar scenario are always static, it is easy to create a subjective or local optimal jamming effect. In order to dynamically analyse the execution process of a complete jamming radar mission, this work establishes an equivalent attack‐defence game in which the radar is regarded as a defence decision agent, and the jammer is an attack decision agent. The attributes of the game's players, the rules of the game, and the conditions for the end of the game are set clearly by setting reasonable parameters. After searching for antagonism strategies by exhaustive method, it can be found that the survivability of the predictive cognitive jamming is much stronger than that of the normal jamming based on real‐time sampling data of radars. This conclusion is demonstrated through a 1 ms simulation of the game process.
Intensivmedizin bei älteren Patienten – Berücksichtigung von altersbedingter Organdysfunktion und Vulnerabilität
Authors: Michels Guido , Müller-Werdan Ursula 
Published: October 2019

Was ist neu?
Altersphysiologische Organ- bzw. Organsystemveränderungen Alle Organe des Menschen durchlaufen eine altersbedingte Funktionseinschränkung bzw. einen Alterungsprozess. So bleiben Herz, Lunge, Nieren, Gastrointestinaltrakt, Hormon- und Immunsystem und v. a. dem Gehirn geringere physiologische Reserven, um gegenüber Noxen oder abweichenden Bedingungen ihre Funktion erhalten zu können. Bei intensivpflichtigen Patienten stellt v. a. ein Delir einen prognostisch ungünstigen Faktor dar. Umso wichtiger ist hier ein effektives Management.
Altersbedingte Vulnerabilität Nicht das Lebensalter allein wirkt sich auf die vergleichsweise erhöhte Sterblichkeit bei älteren Patienten aus. Zu den entscheidenden Vulnerabilitätsfaktoren zählen auch v. a. die Gebrechlichkeit, der Ernährungszustand, die kognitive Funktion sowie die Schwere der aktuellen Krankheit und Komorbiditäten.
Begrenzung des Therapieziels Den immer größeren technischen Möglichkeiten der Medizin stehen oft die ethischen Forderungen entgegen: Respekt vor Autonomie, Nicht-Schaden, Fürsorge, Gerechtigkeit. Entscheidend ist schließlich der Patientenwille, auch wenn es oft eine Herausforderung darstellt, diesen bestimmen und befolgen zu können.
Stereoselective Preparation and Reactions of Chiral Secondary Alkyllithiums
Authors: Skotnitzki Juri , Kremsmair Alexander , Knochel Paul 
Published: October 2019

The preparation of chiral non-stabilized open-chain alkyl­lithium reagents prepared from the corresponding chiral secondary alkyl iodides and their subsequent transmetalation to the corresponding secondary alkylcopper or alkylzinc derivatives is reviewed. These new organometallic reagents allow the stereoselective preparation of a broad range of chiral molecules.1	Introduction2	Stereoselective Preparation of Secondary Alkyllithiums3	Preparation of Stereodefined Secondary Alkylcopper Reagents4	Preparation of Stereodefined Secondary Alkylzinc Derivatives and Their Stereoselective Cross-Coupling with Alkenyl and Aryl Halides­5	Conclusion
Balance-equation method for simulating terahertz quantum-cascade lasers using a wave-function basis with reduced dipole moments of tunnel-coupled states
Authors: Ushakov D.V. , Afonenko A.A. , Dubinov A.A. , Gavrilenko V.I. , Volkov O.Yu. , Shchavruk N.V. , Ponomarev D.S. , Khabibullin R.A. 
Published: October 2019

Abstract
A model based on a system of balance equations for localised and continuum states is developed to calculate the current − voltage (I − V) and power characteristics of quantum-cascade lasers (QCLs) operating in the terahertz (THz) range. A method for modifying the eigenbasis of the Schrödinger equation by reducing the dipole moments of tunnel-coupled states is proposed to take into account the effect of dephasing on the carrier transport. The calculated and experimental data on the current − voltage characteristics and the dependence of the integrated radiation intensity on current for the THz QCLs lasing at 2.3 THz are compared. The calculated and measured values of the threshold current, lasing current range, and maximum operating temperature T
max are found to be in good agreement. It is shown that T
max can be increased by 25 % by reducing the thickness of the top contact layer n
+-GaAs of the laser structure under study from 800 to 100 nm.
Superluminescent diodes based on asymmetric double-quantum-well heterostructures
Authors: Andreeva E.V. , Il’chenko S.N. , Ladugin M.A. , Marmalyuk A.A. , Pankratov K.M. , Shidlovskii V.R. , Yakubovich S.D. 
Published: October 2019

Abstract
The power and spectral characteristics of near-IR superluminescent diodes (SLDs) based on asymmetric double-quantum-well GaAs/InGaAs heterostructures are studied experimentally. It is shown that, varying the active layer composition and the spatial-single-mode active channel length of these SLDs, it is possible to widely change the achievable output optical power and the spectral width of the symmetric bell-shaped spectrum. The studied SLDs have a lower coherence function pedestal, a weaker dependence of the spectral width on the injection current, and a higher polarisation degree than the widely spread SLDs based on single-quantum-well heterostructures with the same spectral widths.
Linking scaling laws across eukaryotes
Authors: Hatton Ian A. , Dobson Andy P. , Storch David , Galbraith Eric D. , Loreau Michel 
Published: October 2019

Significance
Metabolic scaling theory has had a profound influence on ecology, but the core links between species characteristics have not been formally tested across the full domain to which the theory claims to apply. We compiled datasets spanning all eukaryotes for the foremost body mass scaling laws: metabolism, abundance, growth, and mortality. We show that metabolism and abundance scaling only follow the canonical ±3/4 slopes within some taxonomic groups, but across eukaryotes reveal reciprocal near ±1 slopes, broadly supporting the “energetic equivalence rule.” In contrast to metabolism, growth follows consistent ∼3/4 scaling within many groups and across all eukaryotes. Our findings are incompatible with a metabolic basis for growth scaling and instead point to growth dynamics as foundational to biological scaling.
Climate-driven regime shifts in a mangrove–salt marsh ecotone over the past 250 years
Authors: Cavanaugh Kyle C. , Dangremond Emily M. , Doughty Cheryl L. , Williams A. Park , Parker John D. , Hayes Matthew A. , Rodriguez Wilfrid , Feller Ilka C. 
Published: October 2019

Significance
In recent years, tropical species have expanded poleward into temperate regions. For example, along the east coast of North America, mangroves have expanded into salt marshes in response to decreases in the frequency of extreme freezes. But questions remain about how mangrove abundance has changed over longer timescales and the role of anthropogenic climate change. We used a mixed methods approach to document a series of climate-driven shifts in mangrove abundance over the past 250 y. However, climate model projections suggest warming may push this fluctuating system toward a persistent state of mangrove dominance. This historical approach can be applied to a variety of ecosystems to place the effects of climate change in the context of long-term natural climate variability.
Divergent roles of astrocytic versus neuronal EAAT2 deficiency on cognition and overlap with aging and Alzheimer’s molecular signatures
Authors: Sharma Abhijeet , Kazim Syed Faraz , Larson Chloe S. , Ramakrishnan Aarthi , Gray Jason D. , McEwen Bruce S. , Rosenberg Paul A. , Shen Li , Pereira Ana C. 
Published: October 2019

Significance
The excitatory amino acid transporter 2 (EAAT2) is the predominant glutamate transporter in the mammalian brain, and its expression is reduced in aging and sporadic Alzheimer’s disease (AD) brains. The mechanisms through which reduced EAAT2 expression contributes to cognitive decline and AD-related neurodegeneration and the differential functional roles of its astrocytic and neuronal components remain largely unknown. This study uses behavioral analysis to show that astrocytic and neuronal EAAT2 deficiency in mice causes age-dependent cognitive dysfunction. Furthermore, we show that gene expression from human AD and aging datasets have a robust overlap with astrocytic EAAT2 deficiency. This study highlights the distinct signaling mechanisms mediated by neuronal and astrocytic EAAT2 and EAAT2 as a potential therapeutic target in aging and AD.
DNA methyltransferase inhibitors induce a BRCAness phenotype that sensitizes NSCLC to PARP inhibitor and ionizing radiation
Authors: Abbotts Rachel , Topper Michael J. , Biondi Christopher , Fontaine Daniel , Goswami Reena , Stojanovic Lora , Choi Eun Yong , McLaughlin Lena , Kogan Aksinija A. , Xia Limin , Lapidus Rena , Mahmood Javed , Baylin Stephen B. , Rassool Feyruz V. 
Published: October 2019

Significance
We introduce a key role for low doses of DNA methyltransferase inhibitors (DNMTis) in reprogramming the DNA repair transcriptome and creating a homologous recombination defect (HRD), sensitizing to poly (ADP-ribose) polymerase (PARP) inhibitors (PARPis) in breast cancer gene (BRCA)-proficient nonsmall cell lung cancer (NSCLC), which are not clinically responsive to PARPis. The nonhomologous end-joining pathway is also downregulated by DNMTis, generating sensitivity to radiation therapy (RT). The significant increases in antitumor effects with DNMTi and PARPis in combination with RT suggest a potentially potent therapeutic strategy for patients with BRCA-proficient NSCLC, for whom limited therapy is available.
The rhizobial type III effector ErnA confers the ability to form nodules in legumes
Authors: Teulet Albin , Busset Nicolas , Fardoux Joël , Gully Djamel , Chaintreuil Clémence , Cartieaux Fabienne , Jauneau Alain , Comorge Virginie , Okazaki Shin , Kaneko Takakazu , Gressent Frédéric , Nouwen Nico , Arrighi Jean-François , Koebnik Ralf , Mergaert Peter , Deslandes Laurent , Giraud Eric 
Published: October 2019

Significance
Legumes have a tremendous ecological and agronomic importance due to their ability to interact symbiotically with nitrogen-fixing rhizobia. In most of the rhizobial–legume symbioses, the establishment of the interaction requires the plant perception of the bacterial lipochitooligosaccharide Nod factor signal. However, some bradyrhizobia can activate the symbiosis differently, thanks to their type III secretion system, which delivers effector proteins into the host cell. Here, we demonstrate that this symbiotic process relies on a small set of effectors playing distinct and complementary roles. Most remarkably, a nuclear-targeted effector named ErnA conferred the ability to form nodules. The understanding of this alternative pathway toward nitrogen-fixing symbiosis could pave the way for designing new strategies to transfer nodulation into cereals.
Recurrence is required to capture the representational dynamics of the human visual system
Authors: Kietzmann Tim C. , Spoerer Courtney J. , Sörensen Lynn K. A. , Cichy Radoslaw M. , Hauk Olaf , Kriegeskorte Nikolaus 
Published: October 2019

Significance
Understanding the computational principles that underlie human vision is a key challenge for neuroscience and could help improve machine vision. Feedforward neural network models process their input through a deep cascade of computations. These models can recognize objects in images and explain aspects of human rapid recognition. However, the human brain contains recurrent connections within and between stages of the cascade, which are missing from the models that dominate both engineering and neuroscience. Here, we measure and model the dynamics of human brain activity during visual perception. We compare feedforward and recurrent neural network models and find that only recurrent models can account for the dynamic transformations of representations among multiple regions of visual cortex.
Early hominins evolved within non-analog ecosystems
Authors: Faith J. Tyler , Rowan John , Du Andrew 
Published: October 2019

Significance
Testing ecological hypotheses of human evolution requires an understanding of the ancient plant and animal communities within which our ancestors lived. Though present-day ecosystems provide the baseline for reconstructing the ecological context of human evolution, the extent to which modern ecosystems are representative of past ones is unknown. Through analyses of a fossil dataset spanning the last 7 Myr, we show that eastern African communities of large-bodied mammalian herbivores differed markedly from those today until ∼700,000 y ago. Because large herbivores are ecosystem engineers and shape biotic communities in ways that impact a wide variety of species, this implies that the vast majority of early human evolution transpired in the context of ecosystems that functioned unlike any known today.
Technology-mediated task-based interaction
Authors: Ziegler Nicole , Phung Huy 
Published: October 2019

Abstract
This exploratory study examines the extent to which mode differentially impacts the quantity and quality of
interactional features in second language (L2) task-based interaction. Following a within-subject, repeated measures design,
intermediate adult learners (n = 20) completed four (counter-balanced) tasks with a confederate interlocutor in
the following conditions: audio-chat, video-chat, text-chat, and multimodal chat (in which participants could interact using more
than one form of communication). Quantitative analyses examined the quality of learners’ interactions, including negotiation,
recasts, and LREs. Data regarding learners’ perceptions of type of technology were also collected to provide a more holistic
perspective. The results demonstrate differences in terms of interactional features and learners’ preference based on mode of
technology.