bluuebunny/crossref_metadata_2025 huggingface dataset:
Resistive switching properties of monolayer h-BN atomristors with different electrodes
Authors: Li Yuan , Cui Zhenjun , He Yanwei , Tian Hao , Yang Tianchen , Shou Chengyun , Liu Jianlin
Published: April 2022

Resistive switching properties based on molecular beam epitaxy-grown monolayer hexagonal boron nitride (h-BN) atomristors are studied by using metal insulator metal configurations with different electrode materials. Au/monolayer h-BN/Ni devices demonstrate a forming-free bipolar resistive switching (BRS) behavior, a good endurance with up to 97 cycles at a high compliance current of 100 mA, an average on/off ratio of 103, and a low set/reset voltage variability. Metal/monolayer h-BN/graphite/Co devices exhibit self-compliant current BRS characteristics. Both metal/h-BN/Ni and metal/h-BN/graphite/Co devices show the coexistence of BRS, unipolar resistive switching (URS), and nonvolatile threshold switching (TH) modes. The formation of conductive filaments is attributed to the diffusion and trapping of metal ions on the defect sites driven by the electric field, while the rupture is driven by the electric field in BRS and by Joule heating in URS and TH modes.
Preparation of bulk nano-aluminum materials from nanopowder using explosive consolidation
Authors: Zhang Jing , Guo Zhuowei , Sang Shengjun , Li Chenchen , Li Bin , Zhang Dan , Xie Lifeng
Published: April 2022

To optimize powder explosive consolidation technology, an improved explosive consolidation device capable of relieving pressure was designed. Bulk nano-aluminum materials achieving more than 98% of standard density were successfully fabricated by explosive consolidation. The effect of different detonation velocities on the properties of the consolidated aluminum was investigated by varying the ratio of the ammonium nitrate explosive (AN-TNT) and wood flour to adjust the detonation velocity. The results revealed that the production of “Mach holes” (defects produced by excess energy in a converging shock wave) can be reduced by decreasing the detonation velocity. At a detonation velocity of 2158 m/s, bulk aluminum with high density, high hardness, high strength, and uniform microstructure without any Mach holes and with a grain size of about 80 nm can be achieved. The hardness of explosively consolidated aluminum was four times that of aluminum prepared by general industrial technology, and its compressive strength double that of industrially prepared aluminum.
Can one detect intermediate denaturation states of DNA sequences by following the equilibrium open–close dynamic fluctuations of a single base pair?
Authors: Chauhan Keerti , Singh Amit Raj , Kumar Sanjay , Granek Rony
Published: April 2022

Melting of DNA sequences may occur through a few major intermediate states, whose influence on the melting curve has been discussed previously, while their effect on the kinetics has not been explored thoroughly. Here, we chose a simple DNA sequence, forming a hairpin in its native (zipped) state, and study it using molecular dynamic (MD) simulations and a model integrating the Gaussian network model with bond-binding energies—the Gaussian binding energy (GBE) model. We find two major partial denaturation states, a bubble state and a partial unzipping state. We demonstrate the influence of these two states on the closing–opening base pair dynamics, as probed by a tagged bond auto-correlation function (ACF). We argue that the latter is measured by fluorescence correlation spectroscopy experiments, in which one base of the pair is linked to a fluorescent dye, while the complementary base is linked to a quencher, similar to the experiment reported by Altan-Bonnet et al. [Phys. Rev. Lett. 90, 138101 (2003)]. We find that tagging certain base pairs at temperatures around the melting temperature results in a multi-step relaxation of the ACF, while tagging other base pairs leads to an effectively single-step relaxation, albeit non-exponential. Only the latter type of relaxation has been observed experimentally, and we suggest which of the other base pairs should be tagged in order to observe multi-step relaxation. We demonstrate that this behavior can be observed with other sequences and argue that the GBE can reliably predict these dynamics for very long sequences, where MD simulations might be limited.
Revealing the intrinsic p-to-n transition mechanism on Mg3Sb2 through extra Mg
Authors: Zhang Xiong , Cao Xiaoliang , Zhang Yu , Gu Haoshuang , Liu Jibing , Han Guang , Zhang Bin , Wang Guoyu , Zhou Xiaoyuan
Published: April 2022

The intrinsic p-to-n transition mechanism for Mg3Sb2-based thermoelectrics is revealed through pristine Mg3Sb2 by tunning extra Mg. By using TEM characterization combined with transport measurements, the Mg3Sb2 matrix is proposed to have three stages of evolution with the increase in extra Mg content: Mg vacancy-rich (Sb-rich phase) period, Mg vacancy-compensated (nearly no precipitates) period, and Mg vacancy-deficient (Mg-rich phase) period, revealing that the Mg vacancy concentration is a key factor in the intrinsic p-to-n transition. Our work will deepen the understanding of p-to-n transition in Mg3Sb2-based thermoelectrics and provide valuable references for developing other p/n-coexisted thermoelectrics.
Ultra-broadband light detection based on the light-induced transverse thermoelectric effect of epitaxial PbSe thin films with inclined structure
Authors: Chen Mingjing , Chen Xuyang , Wang Qinyi , Ning Xingkun , Li Zhiliang , Yan Guoying , San Xingyuan , Wang Shufang
Published: April 2022

PbSe is a simple binary compound that has been studied extensively for use as a promising moderate-temperature thermoelectric material. In this Letter, we report the observation of the light-induced transverse thermoelectric (TTE) effect in c-axis inclined PbSe thin films that were grown epitaxially on c-axis miscut SrTiO3 single crystal substrates using the pulsed laser deposition technique. Because of the anisotropic Seebeck coefficient of these inclined PbSe thin films, high TTE voltage signals were detected when the film surfaces were irradiated using various different continuous-wave lasers with wavelengths ranging from the ultraviolet (360 nm) to the far infrared (10.6 μm). In addition, the amplitudes of the output voltage signals showed good linear dependence on both the radiation power density and the film inclination angle. The results above demonstrate the potential of PbSe for self-powered ultra-broadband light detection applications.
Optimal perturbations and transition in the magnetohydrodynamic boundary layer under the influence of a spanwise magnetic field
Authors: Bourcy S. , Velizhanina Y. , Pavlenko Y. , Knaepen B.
Published: April 2022

Many shear flows exhibit laminar to turbulent transitions at subcritical Reynolds numbers. In this context, the computation of the perturbations that exhibit the largest possible transient growth is of central interest as it often sheds light on the actual bypass transition route. In this work, we consider the effect on the transient growth of a spanwise magnetic field in a boundary layer flow of a liquid metal over an electrically insulating flat plate. We compute the optimal perturbations using non-modal theory and perform a parametric study to measure the influence of the magnetic field on their amplification and orientation with respect to the flow direction. We also perform direct numerical simulations to examine how the optimal perturbations evolve in the nonlinear regime. To assess the influence of the boundary layer development, we consider both a constant Blasius base flow profile and a growing base profile. We show that the properties of the optimal perturbations are not significantly affected by the choice of the base profile, whereas it has a more important impact on their evolution in the nonlinear regime.
Numerical study of heat transfer, flow fields, turbulent length scales, and anisotropy in corrugated heat exchanger channels
Authors: Karlsson G. , Fureby C. , Wang L. , Norberg C. , Holm M. , Strömer F.
Published: April 2022

In this study, we report on large eddy simulation (LES) of convectively dominated heat transfer in a corrugated heat exchanger channel using the computational fluid dynamics toolbox, OpenFOAM. A chevron pattern domain with 63 contact points is used to represent the conditions in a real plate heat exchanger (PHE). The unsteady nature of the flow is elucidated using visualization techniques based on volume rendering of temperature and iso surfaces of vorticity defined using the λ2-criterion and contours of wall shear stress and wall heat flux to illustrate the heat transfer process. Global surface averaged temperature and pressure drop are extracted from the LES on successively finer grids, approaching direct numerical simulation resolution, to increase the understanding of grid resolution requirements for LES in PHEs. Industry standard Reynolds-averaged Navier–Stokes simulations are compared to the LES results along selected profiles to demonstrate similarities and differences between the two techniques. The differences detected are further investigated using anisotropy invariant mapping, energy spectra, and turbulence length scale distributions. Significant differences between the model classes are detected and detailed. Moreover, the LES resolution requirements for the flow and the heat transfer processes are found to be different with the latter being more severe.
Noncollinear magnetic order in epitaxial thin films of the centrosymmetric MnPtGa hard magnet
Authors: Ibarra R. , Lesne E. , Ouladdiaf B. , Beauvois K. , Sukhanov A. S. , Wawrzyńczak R. , Schnelle W. , Devishvili A. , Inosov D. S. , Felser C. , Markou A.
Published: April 2022

Magnetic systems exhibiting spin-canted states have garnered much attention recently for their promising rich exotic properties driven by the real-space spin textures and competing magnetic orders. In this study, we present the structural and magnetic properties of hexagonal 60 nm MnPtGa epitaxial thin films grown by magnetron sputtering on Al2O3(0001) single-crystalline substrates. The MnPtGa film crystallizes in the centrosymmetric P63/mmc (No. 194) space group, showing perpendicular magnetic anisotropy along the c-axis, with a Curie temperature TC = 263 K. In addition, the MnPtGa film undergoes a spin reorientation transition at Tsr = 160 K. We investigated the MnPtGa magnetic ground states using single-crystal neutron diffraction. A structurally forbidden (001) magnetic Bragg reflection emerges below Tsr, indicating the existence of a spin-canted state, where the magnetic moments align ferromagnetically perpendicular to the basal plane, and a non-zero in-plane component exhibits an antiferromagnetic ordering along the c-axis. At 2 K, the refined magnetic moments of Mn are μz = 4.2(4) μB and μx = 1.5(3) μB, projected onto the c-axis and basal plane, respectively. Hence, we determined a 20° Mn spin canting angle off from the c-axis.
Observation of an anisotropic ultrafast spin relaxation process in large-area WTe2 films
Authors: Chen Yequan , Chen Zhendong , Sun Wenxuan , Chen Yongda , Lu Xianyang , Ruan Xuezhong , Wang Fengqiu , Wu Jing , He Liang , Zhang Rong , Xu Yongbing , Wang Xuefeng
Published: April 2022

Weyl semimetal Td-WTe2 hosts the natural broken inversion symmetry and strong spin–orbit coupling, which contains profound spin-related physics within a picosecond timescale. However, the comprehensive understanding of ultrafast spin behaviors in WTe2 is lacking due to its limited quality of large-scale films. Here, we report on an anisotropic ultrafast spin dynamics in highly oriented Td-WTe2 films using a femtosecond pump–probe technique at room temperature. A transient spin polarization-flip transition as fast as 0.8 ps is observed upon photoexcitation. The inversed spin is subsequently scattered by defects with a duration of about 5.9 ps. The whole relaxation process exhibits an intriguing dual anisotropy of sixfold and twofold symmetries, which stems from the energy band anisotropy of the WTe2 crystalline structure and the matrix element effect, respectively. Our work enriches the insights into the ultrafast opto-spintronics in topological Weyl semimetals.
Community participation in Australia’s National Suicide Prevention Trial
Authors: King Kylie , Hall Teresa , Oostermeijer Sanne , Currier Dianne
Published: April 2022

Background National systems-based suicide prevention approaches are increasingly being implemented. Community participation is fundamental to the successful implementation of these approaches, but can be challenging to undertake. We present findings from the evaluation of Australia’s National Suicide Prevention Trial (the Trial). Methods We completed consultations with 127 community members and 46 Primary Health Network (PHN) staff. Thematic analysis was undertaken to understand the process of community participation in the planning and implementation of the Trial. Results Themes were identified regarding: a collaborative PHN; an engaged and passionate community; maintaining engagement; getting the right people involved; and getting stakeholders to work together. Continuous negotiation about Trial ownership, acceptability of the Trial model, and choice of activities was required. Community participation was somewhat challenging for PHNs, taking much longer than anticipated for a range of reasons. Conclusions Future system-based approaches could benefit from the provision of community participation skills training and support to enable a more coordinated, and perhaps more easily achieved, approach to the involvement of community. Despite a long process of relationship building between stakeholders, this led to improved community cohesion and integration in local suicide prevention, ready for future collaborative work.
Space use and daily movement patterns in an arid zone agamid lizard†
Authors: Bernich Adam , Maute Kimberly , Contador-Kelsall Isabella C. , Story Paul G. , Hose Grant C. , French Kristine
Published: April 2022

Context Quantifying the space use and movement patterns of animals is important to understand other aspects of a species ecology, such as habitat use and social systems. However, basic data on space use and movement patterns, and how they are influenced by biotic or abiotic factors, are lacking for many species. Aims We identified the space use and movement patterns of the central bearded dragon (Pogona vitticeps), and assessed how external factors (environmental conditions) and internal factors (sex and morphology) shape these patterns. Methods We tracked 36 P. vitticeps individuals over three seasons from 2017 to 2018. Animals carried tags with a Global Positioning Systems (GPS) device to collect spatial data and an accelerometer to collect movement data in far western New South Wales, Australia. Measurements of body morphology were taken for each individual and ambient temperatures were recorded. Space use was analysed by calculating minimum convex polygons (MCPs) and kernel density estimates (KDEs) using the spatial data. Movement data were analysed to determine whether dragons had moved during 10-min periods. Results Twenty-three out of 36 individuals held defined activity areas. Males with wider tails were most likely to be floaters (i.e. not restricted to specific areas). Evidence of floater behaviour was shown by 45% of females and 20% of males, though both sexes often roamed over distances greater than 1 km. Air temperatures strongly influenced movement rates in both sexes. Movement rate was significantly higher for males than females during late-spring, but not mid-summer, and was inversely related to head sizes and body mass during mid-summer. Interestingly, although there was no correlation observed between daily movement rates and size of MCPs calculated, the movement rates of residents were significantly different from floaters for each season. Conclusions These results confirm that wild P. vitticeps movement patterns are driven by temperature, though space-use patterns vary from previously studied agamids, with high rates of nomadism, possibly due to drought conditions. Individuals varied widely in their space-use tactics, which seem unrelated to size, a potential proxy for social status or age. Implications Our study provides baseline information on a common arid zone agamid that is lacking research in the wild. More complex studies on the ecology of P. vitticeps can build on the findings of this study.
Small-molecule IKKβ activation modulator (IKAM) targets MAP3K1 and inhibits pancreatic tumor growth
Authors: Napoleon John Victor , Sagar Satish , Kubica Sydney P. , Boghean Lidia , Kour Smit , King Hannah M. , Sonawane Yogesh A. , Crawford Ayrianne J. , Gautam Nagsen , Kizhake Smitha , Bialk Pawel A. , Kmiec Eric , Mallareddy Jayapal Reddy , Patil Prathamesh P. , Rana Sandeep , Singh Sarbjit , Prahlad Janani , Grandgenett Paul M. , Borgstahl Gloria E. O. , Ghosal Gargi , Alnouti Yazen , Hollingsworth Michael A. , Radhakrishnan Prakash , Natarajan Amarnath
Published: April 2022

Significance

Pancreatic cancer is a deadly disease with limited therapeutic options. High expression of the kinase MAP3K1 is associated with poor survival among pancreatic cancer patients. MAP3K1 activates the kinase IKKβ, and our studies show that higher levels of activated IKKβ are found in patient-derived tumors as opposed to the surrounding normal tissue. We also show that inhibition of MAP3K1 by a drug-like compound 39-100 results in reduced levels of activated IKKβ. This leads to reduced tumor growth and reduced metastasis in pancreatic cancer models. Therefore, drug candidates like 39-100, that are IKKβ activation modulators, can be developed to treat pancreatic cancer.
Inefficient development of syncytiotrophoblasts in the
Atp11a
-deficient mouse placenta
Authors: Ochiai Yuki , Suzuki Chigure , Segawa Katsumori , Uchiyama Yasuo , Nagata Shigekazu
Published: April 2022

Significance

Plasma membranes are composed of a lipid bilayer in which phosphatidylserine (PtdSer) is confined to the inner leaflet by the action of flippase that translocates PtdSer from the outer to inner leaflets. Two P4-ATPases (ATP11A and ATP11C) work as flippase at plasma membranes. Here, we report that the mouse placenta expresses only ATP11A, and
Atp11a-
deficient mouse embryos die during embryogenesis due to inefficient formation of syncytiotrophoblasts in the placental labyrinth. The flippase-null mutation inactivates human choriocarcinoma BeWo cells to translocate PtdSer into the inner leaflet and undergo cell fusion. These findings highlight the importance of flippase to regulate the distribution of phospholipids for cell fusion, at least in trophoblast fusion.
Convergent total synthesis of (+)-calcipotriol: A scalable, modular approach to vitamin D analogs
Authors: Gu Jieyu , Rodriguez Kevin X. , Kanda Yuzuru , Yang Shenghua , Ociepa Michal , Wilke Henrik , Abrishami Arteen V. , Jørgensen Lars , Skak-Nielsen Tine , Chen Jason S. , Baran Phil S.
Published: April 2022

Significance

Vitamin D (VitD), a group of secosteroids, has proved to be an essential molecule in supporting overall human health. Structurally, modification at C20 has led to the discovery of novel analogs with a wide range of biological targets. Among them, calcipotriol (Daivonex; LEO Pharma) has been a proven clinical drug for the treatment of psoriasis, an autoimmune skin disease. This work relates to an improved process for the preparation of intermediates useful for the preparation of a range of VitD derivatives, including calcipotriol, and to processes for preparation of calcipotriol. Strategic bond disconnections enable de novo syntheses of both A- and CD-rings not wedded to semisynthesis.
Brap regulates liver morphology and hepatocyte turnover via modulation of the Hippo pathway
Authors: Priest Christina , Nagari Rohith T. , Bideyan Lara , Lee Stephen D. , Nguyen Alexander , Xiao Xu , Tontonoz Peter
Published: April 2022

Significance

The liver has a complex cellular architecture that is essential for its function. In this work, we show that BRAP, a ubiquitin ligase of poorly understood function, is required for maintenance of proper liver morphology. BRAP deletion in the liver causes disruption of its normal architecture and inflammation due to altered expression of genes involved in cell growth and extracellular interactions. This work sheds light on the mechanisms that maintain proper liver structure and has implications for liver disease.
Kick effect of enzymes causes filament compression
Authors: Mao Dan-jian , Qin Chao-ran , Tian Wen-de
Published: April 2022

We investigate the influence of enzymes on the structure and dynamics of a filament by dissipative particle dynamics simulations. Enzyme exerts a kick force on the filament monomer. We pay particular attention to two factors: the magnitude of kick force and enzyme concentration. Large kick force as well as high enzyme concentration prefers a remarkable compression of the filament reminiscent of the effective depletion interaction owing to an effective increase in enzyme size and the reduction of solvent quality. Additionally, the kick effect gives rise to an increase of enzyme density from the center-of-mass of the filament to its periphery. Moreover, the increase of enzyme concentration and kick force also causes a decrease in relaxation time. Our finding is helpful to understand the role of catalytic force in chemo-mechano-biological function and the filament behavior under chemical reaction via kick-induced change of solvent quality.
A generalized algorithm for the automatic diagnosis of sleep apnea from per-sample encoding of airflow and oximetry
Authors: Uddin M B , Chow C M , Ling S H , Su S W
Published: April 2022

Objective. Sleep apnea is a common sleep breathing disorder that can significantly decrease sleep quality and have major health consequences. It is diagnosed based on the apnea hypopnea index (AHI). This study explored a novel, generalized algorithm for the automatic diagnosis of sleep apnea employing airflow (AF) and oximetry (SpO2) signals. Approach. Of the 988 polysomnography records, 45 were randomly selected for developing the automatic algorithm and the remainder 943 for validating purposes. The algorithm detects apnea events by a per-sample encoding process applied to the peak excursion of AF signal. Hypopnea events were detected from the per-sample encoding of AF and SpO2 with an adjustment to time lag in SpO2. Total recording time was automatically processed and optimized for computation of total sleep time (TST). Total number of detected events and computed TST were used to estimate AHI. The estimated AHI was validated against the scored data from the Sleep Heart Health Study. Main results. Intraclass correlation coefficient of 0.94 was obtained between estimated and scored AHIs. The diagnostic accuracies were 93.5%, 92.4%, and 96.6% for AHI cut-off values of ≥5, ≥15, and ≥30 respectively. The overall accuracy for the combined severity categories (normal, mild, moderate, and severe) and kappa were 83.4% and 0.77 respectively. Significance. This new automatic technique was found to be superior to the other existing methods and can be applied to any portable sleep devices especially for home sleep apnea tests.
Experimental distinction of the molecularly induced Balmer emission contribution and its application for inferring molecular divertor density with 2D filtered camera measurements during detachment in JET L-mode plasmas
Authors: Karhunen J , Holm A , Lomanowski B , Solokha V , Aleiferis S , Carvalho P , Groth M , Lawson K D , Meigs A G , Shaw A
Published: April 2022

A previously presented model for generating 2D estimates of the divertor plasma conditions at JET from deuterium Balmer line intensity ratios, obtained from tomographic reconstructions of divertor camera images, was amended to consider also the Balmer emission arising from molecular processes. Utilizing the AMJUEL and H2VIBR atomic and molecular databases of EIRENE enabled also inference of the molecular divertor density from the distinguished molecularly induced emission. Analysis of a JET L-mode density scan suggests the molecularly induced emission accounting for up to 60%–70% and 10%–20% of the Balmer D

α

and D

γ

intensities, respectively, at the onset of detachment, while electron-ion recombination becomes increasingly dominant with deepening detachment. Similar observations were made by post-processing EDGE2D-EIRENE simulations, which indicated significant roles of molecular D

2
+

ions and vibrational excitation of the D2 molecules as precursors for the molecularly induced emission. The experimentally inferred molecular density at the outer strike point was found to increase monotonously with decreasing strike point temperature, reaching approximately 30%–50% of the local electron density at

n

m
o
l

,

o
s
p

=

1–2

×

10

20

m−3 at

T

e
,
o
s
p

≈

0.7 eV. A further steep increase by a factor of 3–5 was observed with decrease of

T

e
,
o
s
p

to 0.5 eV. The observations are in qualitative and reasonable quantitative agreement with EDGE2D-EIRENE predictions of

n

m
o
l

,

o
s
p

within the uncertainties of the experimental data.
A single gate SiGe/Si tunnel FET with rectangular HfO2 dielectric pocket to improve I
on/I
amb current ratio
Authors: Panda Shwetapadma , Mishra Guru Prasad , Dash Sidhartha
Published: April 2022

The ambipolar conduction in the tunnel field-effect transistors (TFETs) is considered the primary hindrance in its usage in complimentary digital circuits and low-power applications. The higher ambipolarity puts a serious question on the efficiency of a TFET, which is a result of channel/drain (C/D) tunneling. This further leads to a significant reduction in the current switching ratio (I
on/I
amb). This paper presents an n-type Si0.6Ge0.4/Si heterostructure TFET with a rectangular dielectric pocket (RDP) to maximize I
on/I
amb current ratio. This has been achieved by suppressing the ambipolarity and improving the on current simultaneously. The existence of Si1−x
Gex in the source and silicon channel provides improved on current (I
on) with controlled leakage current (I
off). Similarly, high-k RDP in the drain reduces ambipolar current (I
amb) significantly and thus, exhibits a higher I
on/I
amb ratio. The different parameters such as x-distance from the C/D interface, y-distance from the gate/drain interface, and dielectric constant has been considered to provide a higher I
on/I
amb ratio of

6.30
×

10
7

. The effect of the presence of interface trap charges and variable Ge mole fraction has been studied. The current ratio can be further improved to

4.0
×

10

12

with an underlap length of 25 nm.
Using Pantheon and Hubble parameter data to constrain the Ricci dark energy in a Bianchi I Universe
Authors: Najafi A , Hossienkhani H
Published: April 2022

In this work, we use the most recent publicly available type Ia supernova (SNIa) compilations and H(z) data. A well formulated cosmological model based on Bianchi type I (BI) metric is implemented in the presence of the Ricci dark energy model. Using the maximum likelihood technique, we estimate the present value of Hubble’s constant H
0 = 70.339 ± 0.743, matter density parameter

Ω

m

0

=
0.297
±
0.031

, anisotropy parameter

Ω

σ

0

=

−0.004 01 ± 0.001 07 within

1
σ
′

confidence level by bounding our derived model with recent joint Pantheon and H(z) data. We have constrained the present value of the equation of state parameter as ω
de = −1.17 joint with the observational data. The present value of the deceleration parameter of the Universe in the derived model is obtained as

q

0

=
−

0.749

−
0.086

+
0.076

. Transition redshift is also derived as

z

tr

∼
0.551

with the recent observations (Pantheon + H(z)) datasets. Finally, we compare the anisotropy effects on the evolution of H(z) for the proposed model under consideration with different observational datasets.
Quasinormal modes and absorption of a massless scalar field for the magnetic Gauss–Bonnet black hole
Authors: Ma Chen , Zhang Yu , Li Qian , Lin Zhi-Wen
Published: April 2022

We study the massless scalar quasinormal frequencies of an asymptotically flat static and spherically symmetric black hole with a nonzero magnetic charge in four-dimensional extended scalar-tensor-Gauss–Bonnet theory. The results show that the real part of the quasinormal frequency becomes larger and the imaginary part becomes smaller with increasing the magnetic charge or the angular harmonic index. The existence of magnetic charges will reduce the damping of scalar perturbation, but increase the frequency. We also study the absorption cross-section of the scalar field in this black hole. We find that its curve will become lower as the magnetic charge increases, i.e. the magnetic charge will weaken the absorption capacity of the black hole. Meanwhile, the high-frequency limit of the total absorption cross-section is just the area of black hole shadow.
Supercell symmetry modified spectral statistics of Kramers–Weyl fermions*
Authors: Lemut G , Pacholski M J , Tworzydło J , Beenakker C W J
Published: April 2022

We calculate the spectral statistics of the Kramers–Weyl Hamiltonian H = v∑
α

σ

α
 sin p

α
+ tσ
0∑
α
cos p

α
in a chaotic quantum dot. The Hamiltonian has symplectic time-reversal symmetry (H is invariant when spin σ

α
and momentum p

α
both change sign), and yet for small t the level spacing distributionP(s) ∝s

β
follows the β = 1 orthogonal ensemble instead of the β = 4 symplectic ensemble. We identify a supercell symmetry of H that explains this finding. The supercell symmetry is broken by the spin-independent hopping energy ∝t cos p, which induces a transition from β = 1 to β = 4 statistics that shows up in the conductance as a transition from weak localization to weak antilocalization.
Air quality status before, during and after the pandemic COVID-19 Movement Control Order (MCO) at urban and suburban areas in Malaysia
Authors: Zahid A Z M , Bakar A A A , Halim N F M , Salleh M Z M
Published: April 2022

A severe acute respiratory syndrome, COVID-19 outbreak started in December 2019 reported in the city of Wuhan, China has spread rapidly in other countries around the world. Declared as a pandemic, the lockdowns, industrial shutdowns, closing international borders and overall reduced mobility of the population either for tourism or work commutes have led to air pollution reduction. The lockdown implemented worldwide including Malaysia has come as a respite to the environment, especially in air pollutant levels. Utilizing the Air Pollutant Index (API) data recorded on an hourly basis throughout different series of national lockdown phases, this study is undertaken to evaluate the air quality status before, during and after the implementation of MCO by comparing the selected urban and suburban areas in Malaysia. Six (6) locations including Bandaraya Melaka, Cheras and Alor Setar (urban) and Seri Manjung, Kangar and Kuantan (suburban) were chosen in this study. The result revealed that the air quality has shown improvements after a further extension of lockdown days at both urban (API 36.3-61.5%) and suburban areas (API 46.5-48.6%). It has indirectly changed the air quality status from ‘moderate’ to ‘good’ in all 6 urban and suburban areas. The air quality trends, however, gradually deteriorate and has increased as more restrictions were eased at a later stage. The implementation of lockdown measures not only restricted the spread of infection rate but has reduced ambient air pollutants levels that lead to enhanced air quality. The results obtained in this study can be a useful insight for the regulatory agencies in controlling air pollution and restore the environment quality.
A review of plastic and microplastic pollution towards the Malaysian marine environment
Authors: Tan E , Jaafar N F , Aileen Tan S H , Mohd Zanuri N B
Published: April 2022

Abstract Plastics are widely used in daily lives but uncontrollably dumped into the ocean by humans. Plastic pollution is harmful to the marine environment and organisms as it can break down into microplastics (MPs) and release chemicals into the water. Microplastics (MPs) are small, fragmented plastic pieces (< 5mm) that exist in every part of the ocean. MPs are problematic because they are hard to recover and can be easily consumed by marine organisms, resulting in bioaccumulation and biomagnification in the food chain. Malaysia is a tropical country located at the heart of Southeast Asia (SEA) and owns diverse marine ecosystems and organisms. Malaysia is affected by plastic pollution due to rapid development and intense economic activities. In this paper, we discuss the plastic pollution crisis in Malaysia and its contributing factor. We review the possible effect on the marine environment in Malaysia. Knowledge gaps to manage plastic pollution in Malaysia are also addressed. As MPs are consistently discovered in different compartments of the Malaysian marine environment, there is an urgency to develop a better waste management system and strong cooperation from all societal levels to handle plastic pollution in the country.
Precision Agriculture Using Internet Of Thingsin Regosol Soil
Authors: Charibaldi N , Saidi D , Kodong F R
Published: April 2022

The utilization of information and communication technology, especially the Internet of Things (IoT) can use sensors (along with the application interface). Sensors are able to measure features in the soil at any time such as pH, humidity and nutrients. Measurements can be made at any time, meaning the sensor is also able to monitor changes in the value of these features. This study aims to implement an Internet of Things (IoT) Information System to measure and monitor humidity, pH, and NPK levels in Regosol soil planted with mustard greens with capillary irrigation and liquid organic fertilizer. This study used a completely randomized design with two factors, namely the type of liquid organic fertilizer and the number of capillary irrigation wicks. The first factor consists of 4 levels: P0: No liquid organic fertilizer, P1: 5 liters/ha Liquid organic fertilizer from household waste, P2: 5 liters/ha Liquid organic fertilizer from Biduri leaves, P3 : 300 kg/ha NPK fertilizer. The second factor consists of 3 levels: I0: No capillary irrigation, I1: Capillary irrigation with 1 wick, I2: Capillary irrigation with 2 wicks. The results showed that the soil moisture during the growth of mustard greens was 16.59% to 23.48%, the more capillary wick, the higher the soil moisture, the average water requirement for mustard plant growth was 3.16 liters. The application of liquid organic fertilizer has a significant effect on soil pH and soil NPK levels. Capillary irrigation had a significant effect on soil pH, but had no significant effect on soil NPK levels.
Significant role of Corporate to Reduce Farmers Poverty: A Lesson from Eastern Kalimantan, Indonesia
Authors: Suhadi I , Irham J , Mulyo H , Jamhari
Published: April 2022

CSR implementation in Indonesia is regulated within the Republic of Indonesia Law Number 40 of 2007. Supported by these regulations, the implementation of CSR has the same goal as the agricultural development goal, namely to improve the welfare of the farmers. Among the sustainable development goals which will be collaborated with CSR is the poverty reduction within the agricultural sector. There are many studies on CSR disclosure within the company’s perspective, but an overview of the role of CSR implementation in agriculture in reducing farmer poverty remains limited. To find out the poverty level of farmers before and after receiving CSR assistance is part of the purpose of this study. In addition, this study also wants to prove whether CSR assistance has an impact on reducing the poverty level of farmers. This activity was carried out in East Kutai, East Kalimantan Province with 61 farmers spread over 4 villages which were selected purposively. Identification of poverty levels is based on the Central Bureau of Statistics criteria, index of headcount, index of poverty depth, and index of poverty severity. Meanwhile, to find out the impact of CSR assistance, it’s seen through the difference in poverty levels before and after receiving CSR assistance and is tested statistically. The results indicated that CSR assistance had a significant effect on reducing the poverty rate of farmers, from 16.4% to 5.8%. This finding showed that the implementation of CSR assistance is able to contribute positively in overcoming a very important problem in the agricultural sector, namely reducing farmer poverty.
The potency of Vis/NIR spectroscopy for classification of soybean based of colour
Authors: Pahlawan M F R , Murti B M A , Masithoh R E
Published: April 2022

Soybean in various colour is easy to identify using human eyes. However, it is hard to perform manual method for on-line production. Therefore, detection of colour for sorting the soybean is important especially for industries which require a rapid and real-time task. This research was conducted to study the potency of a modular type of VIS/NIR spectroscopy at wavelength of 350-1000 nm to classify black, green, and yellow of soybean seed and flour. Principal component analysis (PCA) and PCA Linear discriminant analysis (PCA-LDA) were used based on various spectra pre-processing techniques. Results showed that PCA-LDA model was able to classify soybean seeds of 97% accuracy and soybean flour of 100% accuracy.
Frost Protection Case Study in Orchards
Authors: Lakatos L , Brotodjojo R R R
Published: April 2022

In two important fruit-growing areas of Hungary (Siófok, Pallag) we analyzed some frost protection methods used in practice, such as paraffin candles, frostbuster and frost protection irrigation. The frost protection experiment was set up by spraying the fruit trees with water at different intervals for half a minute. The canopy of each tree contained 4 thermometers, the average value of which was used to characterize the efficiency of frost protection irrigation. The effectiveness of frost protection in the canopy of the fruit tree can be characterized by the temperature measurable during the protection. The combined presence of sub-freezing water and ice, the freed heat of freezing, keeps the temperature near the protected flowers above 0 ° C, while the ambient air is up to -8 ° C. Frostbuster is a new frost protection technology developed primarily for frost protection in orchards. The device works by butane combustion and produces high (80-90 ° C) temperatures with strong air blowing. The device is towed by a tractor, so it is suitable for protecting up to 5-7 hectares. In the event of severe frosts, the tractor speed must be increased and it is advisable to reduce the size of the protected area. Paraffin candles are placed in a row between the trees. Between every tree or every second tree. As a result, up to a thousand paraffin candles can be placed in each hectare of the protected plantation. Applying them means a lot of human labor and high cost. Our study confirmed that Fostbusteres and paraffin candles only protect against frost up to -4 ° C, while antifreeze irrigation provided effective protection against frosts of up to -7 degrees.
Characteristics of Nutrients on Functional Bread with Additional Red Bean, Soy Bean, and Corn as Food Supplementation for Stunting Children Under Five
Authors: Helmizar  , Sakinah R
Published: April 2022

Stunting is a part of wider nutrition crisis found in one out of four children under five in Indonesia. Functionally, the bread made from red bean, soy bean, and corn was categorized as functional bread. As a functional food, it contains nutritional components that are useful and effective for health, such as amino acid, protein, vitamin, and mineral. It also supports physical growth and brain development of stunting children. The study design was True Experimental Design using Completely Randomized Design (CRD). This study was initiated with the analysis of biochemical nutrition value at Food Technology Laboratory in Andalas University. The result shows that a total of 100 grams of bread contains additional flour of 30 grams of red bean, 30 grams of soya bean, and 20 grams of corn. It has nutritional value of 43,64 grams of carbohydrate, 16,91 grams of protein, 10,38 grams of fat, and 335,6 kcal of calories. Nutrients in the bread with additional red bean, soy bean, and corn are potential as food supplementation, especially for stunting children under five.
Heat kernel estimates for symmetric jump processes with anisotropic jumping kernels
Authors: Kang Jaehoon
Published: April 2022

We show two-sided bounds of heat kernel for symmetric pure jump Markov process in

R

d

\mathbb {R}^d

with jumping kernel

J
(
x
,
y
)

J(x,y)

that is comparable to

\frac {\bbone _{\mathcal {V}}(x-y)}{|x-y|^{d+\alpha }}, where

V

\mathcal {V}

is a union of symmetric cones and

0
>
α
>
2

0>\alpha >2

.
The second gap on complete self-shrinkers
Authors: Cheng Qing-Ming , Wei Guoxin , Yano Wataru
Published: April 2022

In this paper, we study complete self-shrinkers in Euclidean space and prove that an

n
n

-dimensional complete self-shrinker in Euclidean space

R

n
+
1

\mathbb {R}^{n+1}

is isometric to either

R

n

\mathbb {R}^{n}

,

S

n

(

n

)

S^{n}(\sqrt {n})

, or

S
k

(

k

)
×

R

n
−
k

S^k (\sqrt {k})\times \mathbb {R}^{n-k}

,

1
≤
k
≤
n
−
1

1\leq k\leq n-1

, if the squared norm

S
S

of the second fundamental form,

f
3

f_3

are constant and

S
S

satisfies

S
>
1.83379

S>1.83379

. We should remark that the condition of polynomial volume growth is not assumed.
Spherical contact toric manifolds
Authors: Li Hui
Published: April 2022

Let

(
M
,
α
)

(M, \alpha )

be a

2
n
+
1

2n+1

-dimensional connected compact contact toric manifold of Reeb type. Suppose the contact form

α
\alpha

is regular, we find conditions under which

M
M

is homeomorphic to

S

2
n
+
1

S^{2n+1}

.
Helly groups, coarsely Helly groups, and relative hyperbolicity
Authors: Osajda Damian , Valiunas Motiejus
Published: April 2022

A simplicial graph is said to be (coarsely) Helly if any collection of pairwise intersecting balls has non-empty (coarse) intersection. (Coarsely) Helly groups are groups acting geometrically on (coarsely) Helly graphs. Our main result is that finitely generated groups that are hyperbolic relative to (coarsely) Helly subgroups are themselves (coarsely) Helly. One important consequence is that various classical groups, including toral relatively hyperbolic groups, are equipped with a CAT(0)-like structure—they act geometrically on spaces with convex geodesic bicombing. As a means of proving the main theorems we establish a result of independent interest concerning relatively hyperbolic groups: a ‘relatively hyperbolic’ description of geodesics in a graph on which a relatively hyperbolic group acts geometrically. In the other direction, we show that for relatively hyperbolic (coarsely) Helly groups their parabolic subgroups are (coarsely) Helly as well. More generally, we show that ‘quasiconvex’ subgroups of (coarsely) Helly groups are themselves (coarsely) Helly.
‘Why did he do it? Because he’s a Fucking Bloke’: Victim Insights into the Perpetration of Street Harassment
Authors: Hindes Sophie , Fileborn Bianca
Published: April 2022

Despite the pervasive nature of street harassment, there is currently little research exploring who perpetrates street harassment and why. Drawing on interviews with Australians who have experienced street harassment, we examine their insights into perpetration. Participants identified individual-level, social/cultural, structural and contextual factors that facilitate street harassment. While existing theoretical explanations of gendered violence help to account for the perpetration of street harassment, these were not sufficient in accounting for participants’ experiences. Participants often drew on gendered, aged, classed and racial stereotypes in their perceptions of perpetrators. We argue that a nuanced understanding of power that accounts for multiple, intersecting forms of marginalisation is needed to understand who perpetrates, as well as who is perceived to perpetrate street harassment.
Oral Microbiome of Crohn’s Disease Patients With and Without Oral Manifestations
Authors: Hu Shijia , Mok John , Gowans Michelle , Ong David E H , Hartono Juanda Leo , Lee Jonathan Wei Jie
Published: April 2022

Background and Aims

Microbiome dysbiosis is associated with inflammatory destruction in Crohn’s disease [CD]. Although gut microbiome dysbiosis is well established in CD, the oral microbiome is comparatively under-studied. This study aims to characterize the oral microbiome of CD patients with/without oral manifestations.

Methods

Patients with CD were recruited with age-, gender- and race-matched controls. Potential confounders such as dental caries and periodontal condition were recorded. The oral microbiome was collected using saliva samples. Microbial DNA was extracted and sequenced using shotgun sequencing. Metagenomic taxonomic and functional profiles were generated and analysed.

Results

The study recruited 41 patients with CD and 24 healthy controls. Within the CD subjects, 39.0% had oral manifestations with the majority presenting with cobblestoning and/or oral ulcers. Principal coordinate analysis demonstrated distinct oral microbiome profiles between subjects with and without CD, with four key variables responsible for overall oral microbiome variance: [1] diagnosis of CD, [2] concomitant use of steroids, [3] concomitant use of azathioprine and 4] presence of oral ulcers. Thirty-two significant differentially abundant microbial species were identified, with the majority associated with the diagnosis of CD. A predictive model based on differences in the oral microbiome found that the oral microbiome has strong discriminatory function to distinguish subjects with and without CD [AUROC 0.84]. Functional analysis found that an increased representation of microbial enzymes [n = 5] in the butyrate pathway was positively associated with the presence of oral ulcers.

Conclusions

The oral microbiome can aid in the diagnosis of CD and its composition was associated with oral manifestations.
A suboptimal control of linear time-delay problems via dynamic programming
Authors: Gooran Orimi Atefeh , Effati Sohrab , Farahi Mohammad Hadi
Published: April 2022

We study a class of infinite horizon optimal control problems with a state delay, and investigate the dynamic programming approach which leverages the sufficient optimality conditions and provides a closed-loop solution. Importantly, the well-known Lyapunov–Krasovskii functional is applied to relate the solution of the problem to the solution of a set of three Riccati-type matrix differential equations. We then present an analytic-based approach to solve the resultant equations and subsequently provide a suboptimal closed-loop solution for the considered problem. We prove the uniform convergence of the proposed approach and show that the presented closed-loop system is asymptotically stable in the Lyapunov sense. Furthermore, the observability of the linear time-delay system is discussed and proved. Finally, numerical examples illustrate the efficiency of the proposed method.