bluuebunny/crossref_metadata_2025 huggingface dataset:
Initial effect of shifting from traditional to no-tillage on runoff retention and sediment reduction under rainfall simulation
Authors: Salem Haytham Mohamed , Ali Ali Mohamed , Wu Weicheng , Tu Qihong
Published: October 2021

Context Low precipitation and soil erosion are critical threats to sustainable agricultural development in the north-western coastal zone of Egypt. Conservation tillage may offer a good opportunity to mitigate these threats; however, switching from traditional tillage to conservation tillage causes initial challenges such as soil compaction and erosion. Aims This study was designed in order to assess the effects of various tillage practices on soil bulk density, volumetric water content, runoff rate, runoff initiation time, soil loss, sediment yield rate and wheat (Triticum aestivum L.) yield in a cultivated basin area. Furthermore, to investigate the efficacy of various rainfall intensities in generating runoff in a micro-catchment area. Methods Under rainfall simulation, five rainfall intensities (14, 21, 30, 36, and 45 mm h−1) and three tillage practices (contour tillage, CT; traditional tillage, TT; and no tillage, NT) were investigated. Key results Under various rainfall intensities, the CT treatment significantly reduced surface runoff compared with the TT and NT treatments. For the 30 mm h−1 rainfall intensity, the CT treatment decreased sediment yield rate by 58.7% and 49.4% compared with NT and TT treatments, respectively. Furthermore, the CT treatment significantly increased precipitation use efficiency by 11.8% and 19.9% compared with TT and NT treatments, respectively. Additionally, the CT increased grain yield by 12.3% more than TT and 21% more than NT. Conclusions and implications Consequently, it is preferable to encourage farmers to use CT practices when transitioning from traditional tillage to conservation tillage. Moreover, soil compaction and smoothing may contribute to enhance the generated runoff on the micro-catchment area.
Differential effects of PD-1 and CTLA-4 blockade on the melanoma-reactive CD8 T cell response
Authors: Gangaev Anastasia , Rozeman Elisa A. , Rohaan Maartje W. , Isaeva Olga I. , Philips Daisy , Patiwael Sanne , van den Berg Joost H. , Ribas Antoni , Schadendorf Dirk , Schilling Bastian , Schumacher Ton N. , Blank Christian U. , Haanen John B. A. G. , Kvistborg Pia
Published: October 2021

Significance

Despite the success of checkpoint-targeting therapies, many melanoma patients do not respond or acquire resistance after initial responsiveness. A better understanding about the mechanism by which these therapies enhance immune-mediated tumor control is key to providing the rationale for better treatment strategies. In this study, we show that PD-1 blockade does not modulate the breadth or the magnitude of the circulating tumor-reactive CD8 T cell response. In contrast and in concordance with our previous study, CTLA-4 blockade leads to a broadening of the circulating melanoma-reactive CD8 T cell response. Together, these findings show differential mechanisms of action of CTLA-4 and PD-1 blockade and support the synergy of the combination treatment seen in the clinic.
Optogenetic stimulation of glutamatergic neurons in the cuneiform nucleus controls locomotion in a mouse model of Parkinson’s disease
Authors: Fougère Maxime , van der Zouwen Cornelis Immanuel , Boutin Joël , Neszvecsko Kloé , Sarret Philippe , Ryczko Dimitri
Published: October 2021

Significance

In Parkinson’s disease, alleviating locomotor deficits is a challenge. Clinicians are exploring the deep brain stimulation of the mesencephalic locomotor region, a brainstem region controlling locomotion, but results are mixed. However, the best target in this region in Parkinson’s disease remains unknown. Indeed, this region, which comprises the pedunculopontine and cuneiform nuclei, contains different cell types with opposing effects on locomotor output. Here, using mice in which midbrain dopaminergic cells were damaged by a neurotoxin, we demonstrate that optogenetic activation of glutamatergic neurons in the cuneiform nucleus increases locomotion, controls speed, and evokes limb movements similar to those observed during spontaneous locomotion in intact animals. Our study identifies a potentially clinically relevant target to improve locomotor function in Parkinson’s disease.
The translatome of neuronal cell bodies, dendrites, and axons
Authors: Glock Caspar , Biever Anne , Tushev Georgi , Nassim-Assir Belquis , Kao Allison , Bartnik Ina , tom Dieck Susanne , Schuman Erin M.
Published: October 2021

Significance

Proteins are the key drivers of neuronal synaptic function. The regulation of gene expression is important for the formation and modification of synapses throughout the lifespan. The complexity of dendrites and axons imposes unique challenges for protein supply at remote locations. The discovery of messenger RNAs (mRNAs) and ribosomes near synapses has shown that local protein synthesis represents an important solution to this challenge. Here we used RNA sequencing and ribosome sequencing to determine directly the population of mRNAs that is present and in the process of translation in neuronal cell bodies, dendrites, and axons. Thousands of transcripts were differentially translated between the cell body and synaptic regions with over 800 mRNAs exhibiting more translation in the dendritic–axonal compartment.
Microstructural evolution and mechanical behaviour of Nb–10Hf–15W alloy doped with Si
Authors: Liao Junhua , Yu Fan , Wei Zhenhe , Sha Jiangbo
Published: October 2021

The microstructural evolution and mechanical properties of Nb–10Hf–15W–(0/1/3/5)Si (at.-%) alloys were investigated. The as-cast 0Si and 1Si alloys had a single Nb solid solution (NbSS) phase, while the 3Si and 5Si alloys consisted of NbSS matrix and the eutectic of NbSS plus Nb3Si. After heat treatment, the microstructure contained primary NbSS and NbSS + α-Nb5Si3 eutectoid in 3Si and 5Si alloys. Fracture toughness of as-cast and heat-treated samples at room temperature monolithically decreased with increasing Si content. However, the α-Nb5Si3 phase improved compressive strength of the NbSS alloy at 1250 and 1350°C, with no degradation in the ductility or formability of the NbSS/Nb5Si3 microstructure. Finally, the failure mechanisms of the NbSS/α-Nb5Si3 microstructure at room and high temperatures were discussed.
Enhanced IL-2 in early life limits the development of TFH and protective antiviral immunity
Authors: Pyle Chloe J. , Labeur-Iurman Lucia , Groves Helen T. , Puttur Franz , Lloyd Clare M. , Tregoning John S. , Harker James A.
Published: October 2021

T follicular helper cell (TFH)–dependent antibody responses are critical for long-term immunity. Antibody responses are diminished in early life, limiting long-term protective immunity and allowing prolonged or recurrent infection, which may be important for viral lung infections that are highly prevalent in infancy. In a murine model using respiratory syncytial virus (RSV), we show that TFH and the high-affinity antibody production they promote are vital for preventing disease on RSV reinfection. Following a secondary RSV infection, TFH-deficient mice had significantly exacerbated disease characterized by delayed viral clearance, increased weight loss, and immunopathology. TFH generation in early life was compromised by heightened IL-2 and STAT5 signaling in differentiating naive T cells. Neutralization of IL-2 during early-life RSV infection resulted in a TFH-dependent increase in antibody-mediated immunity and was sufficient to limit disease severity upon reinfection. These data demonstrate the importance of TFH in protection against recurrent RSV infection and highlight a mechanism by which this is suppressed in early life.
Exploring the self-tuning of the cosmological constant from Planck mass variation
Authors: Blanco Daniel Sobral , Lombriser Lucas
Published: October 2021

Recently, the variation of the Planck mass in the general relativistic Einstein–Hilbert action was proposed as a self-tuning mechanism of the cosmological constant, preventing standard model vacuum energy from freely gravitating and enabling an estimation of the magnitude of its observed value. We explore here new aspects of this proposal. We first develop an equivalent Einstein-frame formalism to the current Jordan-frame formulation of the mechanism and use this to highlight similarities and differences of self-tuning to the sequestering mechanism. We then show how with an extension of the local self-tuning action by a coupled Gauss–Bonnet term and a companion four-form field strength, graviton loops can be prevented from incapacitating the degravitation of the standard model vacuum energy. For certain cases, we furthermore find that this extension can be recast as a Horndeski scalar–tensor theory and be embedded in the conventional local self-tuning formalism. We then explore the possibility of a unification of inflation with self-tuning. The resulting equations can alternatively be used to motivate a multiverse interpretation. In this context, we revisit the coincidence problem and provide an estimation for the probability of the emergence of intelligent life in our Universe as a function of cosmic age, inferred from star and terrestrial planet formation processes. We conclude that we live at a very typical epoch, where we should expect the energy densities of the cosmological constant and matter to be of comparable size. For a dimensionless quantity to compare the emergence of life throughout the cosmic history of different universes in an anthropic analysis of the multiverse, we choose the order of magnitude difference of the evolving horizon size of a Universe to the size of its proton as the basic building block of atoms, molecules, and eventually life. For our Universe we find this number to form peak at approximately 42. We leave the question of whether the same number is frequently assumed for the emergence of life across other universes or singles out a special case to future exploration.
Enhanced broadband monopole emission and acoustic energy harvesting via a dual anisotropic metamaterial
Authors: Lei Yunzhong , Wu Jiu Hui , Huang Zhen , Yang Shaokun
Published: October 2021

Broadband sound energy enhancement is essential in practical scenarios, such as acoustic positioning and acoustic communication. In this paper, a dual anisotropic metamaterial composed of an inner Mie resonator and an outer acoustic grating is proposed, aiming to achieve enhanced broadband monopole emission and acoustic energy harvesting (AEH) via the coupling of the first and second monopole resonances. Considering thermo-viscous dissipation, numerical simulations and experimental results demonstrate that the dual anisotropic metamaterial can realize omnidirectional enhanced broadband monopole emission at 795 Hz–1511 Hz, the maximum sound pressure level (SPL) gain is 16.4 dB and the SPL gain fluctuation is 3 dB. Furthermore, simulation results reveal that the broadband AEH can be achieved by the dual anisotropic metamaterial, the fluctuation of the SPL gain at 794 Hz–1537 Hz is 3 dB and the maximum is 14.7 dB. Based on the results, the dual anisotropic metamaterial is expected to show significant potentials in acoustic positioning and acoustic communication.
Dye-synthesized N, S co-doped carbon via plasma engineering as metal-free oxygen reduction reaction electrocatalysts
Authors: Son Hyunjee , Kim Seonghee , Lee Jin Hong , Li Oi Lun
Published: October 2021

Emerging metal-free heterogeneous element-doped carbon-based catalysts have shown advantages of high catalytic efficiency and low cost, and are regarded as a promising alternative to metal catalysts in alkaline-based fuel cells and metal–air batteries. Methylene blue, commonly used to stain specimens, has been causing serious marine pollution and should be considered for eco-friendly recycling. In this study, methylene blue was chosen as an additive and precursor for N- and S-doped carbon nanoparticles and was dissolved in quinoline (C9H7N) to synthesize N, S co-doped carbon electrocatalysts via plasma engineering. Based on the electrochemical analysis conducted using a rotating ring disk electrode system, compared to the carbon catalyst synthesized from pure quinoline, the oxygen reduction reaction (ORR) performance was enhanced by increasing the amount of methylene blue (E
onset = 0.78 V (vs RHE) at 100% quinoline, 0.79 V (vs RHE) at 1 mM MBQ-G, 0.84 V (vs RHE) at 2 mM MBQ-G, and 0.86 V (vs RHE) at 3 mM MBQ-G). From the electrochemical results, the onset potential (E
onset), half-wave potential (E
1/2), and Tafel slope of 3 mM MBQ-G showed the best performance among all the carbon-based catalysts. In addition, the durability properties of 3 mM methylene blue (declined 30 mV after 6000 cycles) is superior to that of the benchmark ORR catalysts of 20 wt.% Pt/C (declined 60 mV after 6000 cycles). Through this study, we have successfully shown the possibility to effectively recycle methylene blue, which often causes marine and water pollution in the dyeing industry, as a useful precursor in carbon-based catalytic materials.
A modified hybrid chemical vapor deposition method for the fabrication of efficient CsPbBr3 perovskite solar cells
Authors: Ullah Saad , Liu Linlin , Yang Shi-E , Liu Ping , Guo Haizhong , Chen Yongsheng
Published: October 2021

Due to its outstanding stability, all-inorganic cesium lead bromide (CsPbBr3) perovskite is gaining increasing attention as a functional material in photovoltaics and other optoelectronic applications. However, the preparation of high-quality CsPbBr3 films via solution processing remains a significant challenge due to the cesium precursor’s low solubility in common solvents. As a result, developing viable evaporation deposition strategies is critical for increasing the photovoltaic performance of perovskite solar cells (PSCs) based on CsPbBr3. In this paper, a modified hybrid chemical vapor deposition is applied to fabricate CsPbBr3 films, and the effects of reaction temperature and reaction time on the crystallinity, morphology, and photo-electric properties of the films are investigated. By optimizing the reaction conditions, high-quality CsPbBr3 films with good crystallinity and uniformity are successfully obtained. Based on these films, CsPbBr3 PSCs with a device configuration of fluorine-doped tin oxide/compact-TiO2/CsPbBr3/carbon attained impressive power conversion efficiency of 4.41% with an ultra-high open-circuit voltage (V
OC) of 1.39 V. This demonstration suggests that the modified hybrid chemical vapor deposition strategy enables a promising fabrication route suitable for all-inorganic perovskite thin films in photovoltaic application.
Giant magnetoresistance and topological Hall effect in the EuGa4 antiferromagnet
Authors: Zhang H , Zhu X Y , Xu Y , Gawryluk D J , Xie W , Ju S L , Shi M , Shiroka T , Zhan Q F , Pomjakushina E , Shang T
Published: October 2021

We report on systematic temperature- and magnetic field-dependent studies of the EuGa4 binary compound, which crystallizes in a centrosymmetric tetragonal BaAl4-type structure with space group I4/mmm. The electronic properties of EuGa4 single crystals, with an antiferromagnetic (AFM) transition at T
N ∼ 16.4 K, were characterized via electrical resistivity and magnetization measurements. A giant nonsaturating magnetoresistance was observed at low temperatures, reaching

∼
7
×
1

0

4

% at 2 K in a magnetic field of 9 T. In the AFM state, EuGa4 undergoes a series of metamagnetic transitions in an applied magnetic field, clearly manifested in its field-dependent electrical resistivity. Below T
N, in the ∼4–7 T field range, we observe also a clear hump-like anomaly in the Hall resistivity which is part of the anomalous Hall resistivity. We attribute such a hump-like feature to the topological Hall effect, usually occurring in noncentrosymmetric materials known to host topological spin textures (as e.g., magnetic skyrmions). Therefore, the family of materials with a tetragonal BaAl4-type structure, to which EuGa4 and EuAl4 belong, seems to comprise suitable candidates on which one can study the interplay among correlated-electron phenomena (such as charge-density wave or exotic magnetism) with topological spin textures and topologically nontrivial bands.
Negative electron affinity opens quantum well in MgO layers on Ag(100)
Authors: Helmreich Rebecca , Classen Andrej , Fauster Thomas
Published: October 2021

Epitaxial MgO films on Ag(100) were studied by photoelectron spectroscopy. From the low-energy part of the spectra we obtain a negative electron affinity of about −0.9 eV. Even though electrons in the lowest conduction band are not confined by a potential barrier at the surface, quantum-well resonances are observed. The dispersion of the conduction band is determined in good agreement with theoretical calculations. Aspects of observing image-potential states predicted by theory on MgO films are discussed.
Inter-frequency code bias handling and estimation for multi-frequency BeiDou-3/Galileo uncombined precise point positioning
Authors: Cao Xinyun , Shen Fei , Ge Yulong , Liu Chao , Zhang Shoujian
Published: October 2021

The development of a global navigation satellite system (GNSS) with multi-frequency signals brings new opportunities for providing high-quality positioning, navigation and timing (PNT) services. Proper inter-frequency code bias (IFB) handling is a prerequisite for multi-frequency uncombined precise point positioning (UC-PPP) to ensure reliable and accurate PNT services. This work focuses on analyzing the mathematical representation of estimated parameters, as well as the relationship between different multi-frequency UC-PPP models, caused by whether to correct the inter-frequency satellite differential code bias (DCB) or the external ionosphere. Multi-GNSS experiment (MGEX) network stations tracking Galileo E1/E5a/E5b/E6/E5ab and BeiDou-3 (BDS-3) B1I/B3I/B1C/B2a signals were used to investigate the positioning performance and parameter estimations of three multi-frequency UC-PPP models. The results show that the loosely constrained ionosphere will make the estimated ionosphere and DCB/IFB parameters unable to effectively separate due to their high linear dependence. The 3D positioning accuracy of UC-PPP using Galileo five-frequency, BDS-3 four-frequency and Galileo/BDS-3 multi-frequency signals in static mode is 1.76, 2.36 and 1.39 cm, while the corresponding accuracy in kinematic mode is 6.40, 7.08 and 4.16 cm, respectively. The consistency of Galileo IFBs with respect to the MGEX DCB files is rather good, and the probability of deviations within 0.3 ns is 96.58%. Compared to Galileo, the agreement of the BDS-3 IFBs with respect to the reference values is worse, with 92.69% of them within 1 ns.
One-step synthesis of vanadium-doped anatase mesocrystals for Li-ion battery anodes
Authors: Boytsova O V , Drozhzhin O A , Petukhov D I , Chumakova A V , Sobol A G , Beltyukov A N , Eliseev A A , Bosak A B
Published: October 2021

Here we report a successful one-step synthesis of vanadium-doped anatase mesocrystals by reactive annealing of NH4TiOF3/PEG2000 mesocrystal precursors with NH4VO3. The formation solid solution Ti1−x
V
x
O2 with vanadium content up to x = 25 at% inheriting the structure of mesocrystals is observed for the first time. The doping mechanism via vapor phase transport of vanadium is proposed. The Ti1−x
V
x
O2 mesocrystals exhibit improved specific capacity of 175 mAh g−1 (compared to 150 mAh g−1 for pure anatase phase) and decreased potential gap between charge and discharge processes.
A versatile modular preparation strategy for targeted drug delivery systems against multidrug-resistant cancer cells
Authors: Wang Huanhuan , Ning Xiaoyue , Wang Xinnan , Ding Fei , Wang Yongjian
Published: October 2021

Nanotechnology is widely used in targeted drug delivery, but different drug delivery systems need to ‘re-determine’ different synthesis schemes, which greatly limits the further expansion of targeted nanomedicine applications. In this study, we propose a facile and versatile modular stacking strategy to fabricate targeted drug delivery systems to enable tailored designs for patient-specific therapeutic responses. The systems were constructed by a pH-sensitive prodrug module and a mitochondrial targeting module via self-assembly. Using this modular strategy, we successfully prepared two targeting nano-drug delivery systems, TPP-DOX and PK-DOX, where the mitochondrial targeting molecules were triphenylphosphonium (TPP) and 1-(2-Chlorophenyl)-N-methyl-N-(1-methylpropyl)-3-isoquinolinecarboxamide (PK11195), respectively. Confocal laser microscopy and flow cytometry tests revealed that TPP-DOX and PK-DOX exhibited high mitochondria targeting capability and greatly improved the drug retention in drug-resistant cells. The antitumor activity tests showed that the IC50 values of TPP-DOX and PK-DOX in MCF-7/ADR cells were 2.5- and 8.2-fold lower than that of free DOX, respectively. These results indicated that PK was more effective than TPP. The studies on their therapeutic effects on human breast cancer resistant cells verified the feasibility of the modular approach, indicated that the two modular targeted drug delivery systems: (1) retain the drug toxicity and cell-killing effect of the prodrug module, (2) have precise targeting capabilities due to mitochondrial targeting module, (3) enhance drug uptake, reduce drug efflux and reverse the multidrug resistance effect to a certain extent. The results show that modular stacking is a practical, effective and versatile method for preparing targeting drugs with broad application prospects. This study provides an easy approach on preparing customizable targeted drug delivery systems to improve precision therapies.
Anodic TiO2 nanotube arrays for photocatalytic CO2 conversion: comparative photocatalysis and EPR study
Authors: Savchuk Timofey , Gavrilin Ilya , Konstantinova Elizaveta , Dronov Alexey , Volkov Roman , Borgardt Nickolay , Maniecki Tomasz , Gavrilov Sergey , Zaitsev Vladimir
Published: October 2021

Titania (TiO2) is a widely used semiconductor for the photocatalytic decomposition of organic impurities in air, water and the conversion of CO2 into hydrocarbon fuel precursors. TiO2 in the form of nanotubes arrays is the most attractive for practical use because of the morphological advantages providing more favorable diffusion of photocatalytic reaction products and a low recombination rate of photogenerated electrons and holes. We have carried out a comparative study of the photocatalytic activity of gas-phase conversion of CO2 to hydrocarbon products and the defect properties of multi-walled and single-walled arrays of TiO2 nanotubes. Methanol and methane have been detected in the CO2 photoreduction process. The photocatalytic evolution rate of multi-walled TiO2 nanotubes is twice as fast for methane as for single-walled TiO2 nanotubes after four hours of irradiation and four times faster for methanol. The type and features of the structural defects have been investigated by EPR spectroscopy. For the first time, it has been shown that Ti3+/oxygen vacancy centers are mainly located inside the outer layer of nanotubes, while carbon dangling bonds have been observed directly on the surface of the inner layer. Carbon defects have been found to be the centers of adsorption and accumulation of photoinduced charge carriers. The results are entirely new; they clarify the role of different types of defects in the photocatalytic conversion of CO2 to hydrocarbon compounds and show good prospects for applying TiO2 nanotube arrays.
Memristively programmable transistors
Authors: Tappertzhofen S , Nielen L , Valov I , Waser R
Published: October 2021

When designing the gate-dielectric of a floating-gate-transistor, one must make a tradeoff between the necessity of providing an ultra-small leakage current behavior for long state retention, and a moderate to high tunneling-rate for fast programming speed. Here we report on a memristively programmable transistor that overcomes this tradeoff. The operation principle is comparable to floating-gate-transistors, but the advantage of the analyzed concept is that ions instead of electrons are used for programming. Since the mass of ions is significantly larger than the effective mass of electrons, gate-dielectrics with higher leakage current levels can be used. We demonstrate the practical feasibility of the device using a proof-of-concept study based on a micrometer-sized thin-film transistor and LT-Spice simulations of 32 nm transistors. Memristively programmable transistors have the potential of high programming endurance and retention times, fast programming speeds, and high scalability.
Stationary coalescing walks on the lattice II: entropy
Authors: Chaika Jon , Krishnan Arjun
Published: October 2021

This paper is a sequel to Chaika and Krishnan, 2016. We again consider translation invariant measures on families of nearest-neighbor semi-infinite walks on the integer lattice

Z

d

. We assume that once walks meet, they coalesce. We consider various entropic properties of these systems. We show that in systems with completely positive entropy, bi-infinite trajectories must carry entropy. In the case of directed walks in dimension 2 we show that positive entropy guarantees that all trajectories cannot be bi-infinite. To show that our theorems are proper, we construct a stationary discrete-time symmetric exclusion process whose particle trajectories form bi-infinite trajectories carrying entropy.
On long-time behavior of solutions of the Zakharov–Rubenchik/Benney–Roskes system
Authors: Martínez María E , Palacios José M
Published: October 2021

We study decay properties for solutions to the initial value problem associated with the one-dimensional Zakharov–Rubenchik/Benney–Roskes (ZR/BR) system. We prove time-integrability in growing compact intervals of sizetr,r< 2/3, centered on some characteristic curves coming from the underlying transport equations associated with the ZR/BR system. Additionally, we prove decay to zero of the local energy-norm in so-called far-field regions. Our results are independent of the size of the initial data and do not require any parity condition.
Scaled pressure of continuous flows*
Authors: Cheng Dandan , Li Zhiming
Published: October 2021

In this paper we introduce the notion ofscaled pressureof continuous flows. It is proved that scaled pressure is preserved under certain reparametrizations of orbits and Lipschitz conjugations of fixed-point free continuous flows. Moreover, for expansive flows, scaled pressure can be described by period-orbits. In particular, a variational principle is obtained by comparing scaled pressures for continuous flows with their time one maps.
Global multiplicity of solutions for a modified elliptic problem with singular terms
*
Authors: Santos C A , Yang Minbo , Zhou Jiazheng
Published: October 2021

We establish global multiplicity results of solutions for the singular nonlinear problem

−
Δ
u
−
u
Δ

u

2

=
λ
a

(

x

)

u

−
α

+
b

(

x

)

u

β

in

Ω
,

u
>
0

in

Ω
,

u
=
0

on

∂
Ω
,

where

Ω
⊂

R

N

is a smooth bounded domain; N ⩾ 3; a, b are bounded continuous functions, 0 < α < 1 < β ⩽ 22* − 1 and λ > 0 is a real parameter. We first prove a comparison principle to prove the existence of a minimal solution by the method of sub and super solutions and then we also obtain the second solution by critical point theory.
IPEM topical report: results of a 2020 UK survey on the use of online treatment monitoring solutions for IMRT/VMAT
Authors: W Stevens Simon , Moloney Stephen , Bangiri Anna , Blackmore Andrew , Hart Clare , Holmes-Smith William , Pooler Alistair , Rixham Philip , Doolan Paul
Published: October 2021

Numerous commercial technologies for online treatment monitoring (OTM) in radiotherapy (RT) are currently available including electronic portal imaging device (EPID) in vivo dosimetry (IVD), transmission detectors and log files analysis. Despite this, in the UK there exists limited guidance on how to implement and commission a system for clinical use or information about the resources required to set up and maintain a service. A Radiotherapy Special Interest Group working party, established by Institute of Physics and Engineering in Medicine was formed with a view to reassess the current practice for OTM in the UK and an aim to develop consensus guidelines for the implementation of a system. A survey distributed to Heads of Medical Physics at 71 UK RT departments investigated: availability of OTM in the UK; estimates of workload; clinical implementation; methods of analysis; quality assurance; and opinions on future directions. The survey achieved a 76% response rate and demonstrated that OTM is widely supported in the UK, with 87% of respondents indicating all patients should undergo OTM. EPID IVD (EIVD) was the most popular form of OTM. An active EIVD service was reported by 37% of respondents, with 84% believing it was the optimal solution. This demonstrates a steady increase in adoption since 2012. Other forms of OTM were in use but they had only been adopted by a minority of centres. Financial barriers and the increase of staff workload continue to hinder wider implementation in other centres. Device automation and integration is a key factor for successful future adoption and requires support between treatment machine and OTM manufacturers. The survey has provided an updated analysis on the use of OTM methods across the UK. Future guidance is recommended on commissioning, adoption of local tolerances and root-cause analysis strategies to assist departments intending to implement OTM.
Electron acceleration using twisted laser wavefronts
Authors: Shi Yin , R Blackman David , Arefiev Alexey
Published: October 2021

Using plasma mirror injection we demonstrate, both analytically and numerically, that a circularly polarized helical laser pulse can accelerate highly collimated dense bunches of electrons to several hundred MeV using currently available laser systems. The circular-polarized helical (Laguerre–Gaussian) beam has a unique field structure where the transverse fields have helix-like wave-fronts which tend to zero on-axis where, at focus, there are large on-axis longitudinal magnetic and electric fields. The acceleration of electrons by this type of laser pulse is analyzed as a function of radial mode number and it is shown that the radial mode number has a profound effect on electron acceleration close to the laser axis. Using three-dimensional particle-in-cell simulations a circular-polarized helical laser beam with power of 0.6 PW is shown to produce several dense attosecond bunches. The bunch nearest the peak of the laser envelope has an energy of 0.47 GeV with spread as narrow as 10%, a charge of 26 pC with duration of

∼
400

as, and a very low divergence of 20 mrad. The confinement by longitudinal magnetic fields in the near-axis region allows the longitudinal electric fields to accelerate the electrons over a long period after the initial reflection. Both the longitudinal E and B fields are shown to be essential for electron acceleration in this scheme. This opens up new paths toward attosecond electron beams, or attosecond radiation, at many laser facilities around the world.
On the realization of WIMPflation
Authors: Garcia Marcos A.G. , Mambrini Yann , Olive Keith A. , Verner Sarunas
Published: October 2021

We consider models for inflation with a stable inflaton. Reheating is achieved through scattering processes such as ϕϕ→ h h, where h is the Standard Model Higgs boson. We consider the reheating process in detail and show that for a relatively large coupling (needed for the late annihilations of the inflaton during freeze-out), reheating is almost instantaneous leading to a relatively high reheating temperature. The process ϕϕ↔ h h brings the inflaton back into equilibrium, leading to a well studied scalar singlet dark matter candidate and Higgs portal model. We argue that such models can be derived from no-scale supergravity.
Assembly bias in quadratic bias parameters of dark matter halos from forward modeling
Authors: Lazeyras Titouan , Barreira Alexandre , Schmidt Fabian
Published: October 2021

We use the forward modeling approach to galaxy clustering combined with the likelihood from the effective-field theory of large-scale structure to measure assembly bias, i.e. the dependence of halo bias on properties beyond the total mass, in the linear (b1) and second order bias parameters (b2 and bK
2) of dark matter halos in N-body simulations. This is the first time that assembly bias in the tidal bias parameter bK
2 is measured. We focus on three standard halo properties: the concentration c, spin λ, and sphericity s, for which we find an assembly bias signal in bK
2 that is opposite to that in b1. Specifically, at fixed mass, halos that get more (less) positively biased in b1, get less (more) negatively biased in bK
2. We also investigate the impact of assembly bias on the b2(b1) and bK
2(b1) relations, and find that while the b2(b1) relation stays roughly unchanged, assembly bias strongly impacts the bK
2(b1) relation. This impact likely extends also to the corresponding relation for galaxies, which motivates future studies to design better priors on bK
2(b1) for use in cosmological constraints from galaxy clustering data.
Morphogen-regulated contact-mediated signaling between cells can drive the transitions underlying body segmentation in vertebrates
Authors: Kuyyamudi Chandrashekar , Menon Shakti N , Sinha Sitabhra
Published: October 2021

We propose a unified mechanism that reproduces the sequence of dynamical transitions observed during somitogenesis, the process of body segmentation during embryonic development, that is invariant across all vertebrate species. This is achieved by combining inter-cellular interactions mediated via receptor-ligand coupling with global spatial heterogeneity introduced through a morphogen gradient known to occur along the anteroposterior axis. Our model reproduces synchronized oscillations in the gene expression in cells at the anterior of the presomitic mesoderm as it grows by adding new cells at its posterior, followed by travelling waves and subsequent arrest of activity, with the eventual appearance of somite-like patterns. This framework integrates a boundary-organized pattern formation mechanism, which uses positional information provided by a morphogen gradient, with the coupling-mediated self-organized emergence of collective dynamics, to explain the processes that lead to segmentation.
Light-weight electrophysiology hardware and software platform for cloud-based neural recording experiments
Authors: Voitiuk Kateryna , Geng Jinghui , Keefe Matthew G , Parks David F , Sanso Sebastian E , Hawthorne Nico , Freeman Daniel B , Currie Rob , Mostajo-Radji Mohammed A , Pollen Alex A , Nowakowski Tomasz J , Salama Sofie R , Teodorescu Mircea , Haussler David
Published: October 2021

Objective. Neural activity represents a functional readout of neurons that is increasingly important to monitor in a wide range of experiments. Extracellular recordings have emerged as a powerful technique for measuring neural activity because these methods do not lead to the destruction or degradation of the cells being measured. Current approaches to electrophysiology have a low throughput of experiments due to manual supervision and expensive equipment. This bottleneck limits broader inferences that can be achieved with numerous long-term recorded samples. Approach. We developed Piphys, an inexpensive open source neurophysiological recording platform that consists of both hardware and software. It is easily accessed and controlled via a standard web interface through Internet of Things (IoT) protocols. Main results. We used a Raspberry Pi as the primary processing device along with an Intan bioamplifier. We designed a hardware expansion circuit board and software to enable voltage sampling and user interaction. This standalone system was validated with primary human neurons, showing reliability in collecting neural activity in near real-time. Significance. The hardware modules and cloud software allow for remote control of neural recording experiments as well as horizontal scalability, enabling long-term observations of development, organization, and neural activity at scale.
The IFMIF-DONES fusion oriented neutron source: evolution of the design
Authors: Królas W. , Ibarra A. , Arbeiter F. , Arranz F. , Bernardi D. , Cappelli M. , Castellanos J. , Dézsi T. , Dzitko H. , Favuzza P. , García A. , Gutiérrez J. , Lewitowicz M. , Maj A. , Martin-Fuertes F. , Micciché G. , Muñoz A. , Nitti F.S. , Pinna T. , Podadera I. , Pons J. , Qiu Y. , Román R. , Toth M. , Zsakai A.
Published: October 2021

IFMIF-DONES is a powerful neutron irradiation facility for the study and qualification of materials planned as part of the European roadmap to fusion-generated electricity. Its main goal is to study properties of materials under severe irradiation in a neutron field similar to the one in a fusion reactor first wall. It is a key facility to prepare for the construction of the DEMO power plant envisaged to follow ITER. The decision to start the construction of IFMIF-DONES is expected imminent. In this paper we present and discuss several key technical studies and decisions to improve and optimize the engineering design of IFMIF-DONES which were carried out as part of the activities in the framework of the EUROfusion Early Neutron Source work package (2015–2020). The following topics are discussed in this paper: the new layout of the IFMIF-DONES SRF LINAC accelerator and high-energy beam transport line, 7Be impurity management approach for the lithium loop, a maintainable test cell concept, a revised layout of the access cell for the remote maintenance operations, and facilities for complementary experiments.
Observation of low frequency electrostatic coherent oscillation in the proximity of the density limit in the TJ-II stellarator
Authors: Fernández-Ruiz D. , Losada U. , Ochando M.A. , Liu B. , Hidalgo C. , the TJ-II Team
Published: October 2021

Turbulence self-regulation mechanisms are widely believed to be partially governed by the non-linear interplay between turbulence and large-scale plasma flows. In this paper, we employ floating potential data recorded via Langmuir probes to study the evolution of long-range correlated structures in plasmas near the operational density limit of the TJ-II stellarator. The results point towards the presence and amplification of low frequency, coherent, global fluctuations with similar properties to those of the zonal flows in the vicinity of this limit.
Isobaric charge-exchange reactions: a tool to study the excitation of baryonic resonances in exotic nuclear matter
Authors: Rodríguez-Sánchez J L , Benlliure J , Haettner E , Scheidenberger C , Vargas J , Ayyad Y , Alvarez-Pol H , Atkinson J , Aumann T , Beceiro-Novo S , Boretzky K , Caamaño M , Casarejos E , Cortina-Gil D , Fernández P Díaz , Estrade A , Geissel H , Itahashi K , Kelić-Heil A , Lenske H , Litvinov Yu A , Paradela C , Pérez-Loureiro D , Pietri S , Prochazka A , Saito T R , Takechi M , Tanaka Y K , Vidaña I , Weick H , Winfield J S
Published: October 2021

Isobaric charge-exchange reactions induced by beams of 112Sn have been investigated at the GSI facility using the fragment separator FRS. The high-resolving power of this spectrometer makes it possible to obtain the isobaric charge-exchange cross sections with an uncertainty of 3.5% and to separate quasi-elastic and inelastic contributions in the missing-energy spectra, in which the inelastic component is associated to the in-medium excitation of baryonic resonances such as the Δ resonance. We report on the results obtained for the (p,n) channel excited by using different targets that cover a large range in neutron excess. In addition, we also compare the missing-energy spectra with an intranuclear cascade model coupled to a de-excitation code to investigate the in-medium effects in the production of baryonic resonances.
The study of active geomagnetic shielding coils system for JUNO
Authors: Zhang G. , Lu H. , Songwadhana J. , Yan Y. , Morozov N. , Ning F. , Zhang P. , Yang C. , Khosonthongkee K. , Limphirat A. , Yan T. , Payupol T. , Suwonjandee N. , Asavapibhop B. , Sawangwit U. , Sangka A. , Zhu Z. , Wang X. , Liu X. , Xie Z.
Published: October 2021

The Jiangmen Underground Neutrino Observatory (JUNO) is a
large liquid scintillator (LS) detector for neutrino mass ordering
and other neutrino physics research. The detector uses large-size
20 inches photomultiplier tubes to detect photons from a liquid
scintillator. The large PMTs are sensitive and easily affected such
that the detection efficiency loses about 60% under the
geomagnetic field intensity (∼500 mG). It has a significantly
negative effect on the detector performance, and a compensation
system is necessary for geomagnetic field shielding. As permalloys
are easily rusted in water, a better way for the geomagnetic
shielding is to apply an active compensation coils system. The
simulations show that a set of 32 circular coils can meet the
experiment requirement. The residual magnetic field is less than
0.05 G in the Central Detector Photomultiplier Tube (CD-PMT) region
(38.5–39.5 m in diameter). A prototype coil system with a 1.2 m
was built to validate the simulation and the design. The measured
data of prototype and simulation results are consistent with each
other, and geomagnetic field intensity is effectively reduced by
coils, verifying the shielding coils system design for JUNO. This
study is expected to provide practical guidance for the PMT magnetic
field shielding for future large-scale detector designs.
Biomimetic 3D-printed PCL scaffold containing a high concentration carbonated-nanohydroxyapatite with immobilized-collagen for bone tissue engineering: enhanced bioactivity and physicomechanical characteristics
Authors: Moghaddaszadeh Ali , Seddiqi Hadi , Najmoddin Najmeh , Abbasi Ravasjani Sonia , Klein-Nulend Jenneke
Published: October 2021

A challenging approach of three-dimensional (3D)-biomimetic scaffold design for bone tissue engineering is to improve scaffold bioactivity and mechanical properties. We aimed to design and fabricate 3D-polycaprolactone (PCL)-based nanocomposite scaffold containing a high concentration homogeneously distributed carbonated-nanohydroxyapatite (C-nHA)-particles in combination with immobilized-collagen to mimic real bone properties. PCL-scaffolds without/with C-nHA at 30%, 45%, and 60% (wt/wt) were 3D-printed. PCL/C-nHA60%-scaffolds were surface-modified by NaOH-treatment and collagen-immobilization. Physicomechanical and biological properties were investigated experimentally and by finite-element (FE) modeling. Scaffold surface-roughness enhanced by increasing C-nHA (1.7 – 6.1-fold), but decreased by surface-modification (0.6-fold). The contact angle decreased by increasing C-nHA (0.9 – 0.7-fold), and by surface-modification (0.5-fold). The zeta potential decreased by increasing C-nHA (3.2-9.9-fold). Average elastic modulus, compressive strength, and reaction force enhanced by increasing C-nHA and by surface-modification. FE modeling revealed that von Mises stress distribution became less homogeneous by increasing C-nHA, and by surface-modification. Maximal von Mises stress for 2% compression strain in all scaffolds did not exceed yield stress for bulk-material. 3D-printed PCL/C-nHA60% with surface-modification enhanced pre-osteoblast spreading, proliferation, collagen deposition, alkaline phosphatase activity, and mineralization. In conclusion, a novel biomimetic 3D-printed PCL-scaffold containing a high concentration C-nHA with surface-modification was successfully fabricated. It exhibited superior physicomechanical and biological properties, making it a promising biomaterial for bone tissue engineering.
Channeling environmentalism into climate policy: an experimental study of Fridays for Future participants from Germany
Authors: Soliev Ilkhom , Janssen Marco A , Theesfeld Insa , Pritchard Calvin , Pirscher Frauke , Lee Allen
Published: October 2021

This study argues that scholars and policy-makers need to understand environmental activists better to bridge the gap between growing activism and policy. Conventional wisdom is that environmental activists generally support stronger climate policies. But there is still little understanding about diversity of views within activist groups when it comes to specific policies, and existing studies indicate that their views are not uniform, which can weaken their impact as a group. Activists might unite to demand change, but not necessarily agree on details of the desired change. Exploring the differences within the group, this paper focuses on how to nudge those who already share favorable attitudes towards policies that mitigate climate change. The motivation has been to see, in presence of general support for stronger environmental policies, whether this support could be channeled into more specific policies. We first take on a methodological challenge to construct an index of environmental predisposition. Then drawing from existing social-behavioral scholarship, we analyze results of an experimental survey with select treatments previously reported as promising. In November and December 2019, we collected responses from 119 participants at the Fridays for Future demonstrations in Germany. The results indicate that there are indeed important differences within the group, and nudging effects exist even in this rather strongly predisposed group, with participants assigned to the experimental group showing higher levels of support for the introduction of a carbon tax that is traditionally seen as a difficult policy to gain widespread public support. We find that those who score neither too high nor too low are more likely to respond to nudging. Yet, the effects vary for general outcomes such as policy support, behavioral intentions, and environmental citizenship. Overall, the findings show the value of understanding the heterogeneity of individual views within environmental movements better and directing interventions in large resource systems such as climate to specific issues and target groups for accelerating transformations towards sustainability.
Four decades of nitrous oxide emission from Chinese aquaculture underscores the urgency and opportunity for climate change mitigation
Authors: Zhou Yangen , Huang Ming , Tian Hanqin , Xu Rongting , Ge Jian , Yang Xiaogang , Liu Rongxin , Sun Yunxia , Pan Shufen , Gao Qinfeng , Dong Shuanglin
Published: October 2021

As the fastest growing food production sector in the world, aquaculture may become an important source of nitrous oxide (N2O)—a potent greenhouse gas and the dominant source of ozone-depleting substances in the stratosphere. China is the largest aquaculture producer globally; however, the magnitude of N2O emission from Chinese aquaculture systems (CASs) has not yet been extensively investigated. Here, we quantified N2O emission from the CASs since the Reform and Opening-up (1979–2019) at the species-, provincial-, and national-levels using annual aquaculture production data, based on nitrogen (N) levels in feed type, feed amount, feed conversion ratio, and emission factor (EF). Our estimate indicates that over the past 41 years, N2O emission from CASs has increased approximately 25 times from 0.67 ± 0.04 GgN in 1979 to 16.69 ± 0.31 GgN in 2019. Freshwater fish farming, primarily in two provinces, namely, Guangdong and Hubei, where intensive freshwater fish farming has been adopted in the past decades, accounted for approximately 89% of this emission increase. We also calculated the EF for each species, ranging from 0.79 ± 0.23 g N2O kg−1 animal to 2.41 ± 0.14 g N2O kg−1 animal. The results of this study suggest that selecting low-EF species and improving feed use efficiency can help reduce aquaculture N2O emission for building a climate-resilient sustainable aquaculture.