bluuebunny/crossref_metadata_2025 huggingface dataset:
Macroscopic magneto-chiroptical metasurfaces
Authors: Petrucci Gaia , Gabbani Alessio , Faniayeu Ihar , Pedrueza-Villalmanzo Esteban , Cucinotta Giuseppe , Atzori Matteo , Dmitriev Alexandre , Pineider Francesco
Published: June 2021

Nanophotonic chiral antennas exhibit orders of magnitude higher circular dichroism (CD) compared to molecular systems. When the structural chirality is merged with magnetism at the nanoscale, efficient magnetic control over the dichroic response is achieved, bringing exciting prospects to active nanophotonic devices. Here, we devise macroscopic enantiomeric magnetophotonic metasurfaces of plasmonic-ferromagnetic spiral antennas assembled on large areas via hole-mask colloidal lithography. The simultaneous presence of 3D- and 2D-features in chiral nanoantennas induces large CD response, where we identify reciprocal and non-reciprocal contributions, respectively. Exploring further this type of magnetophotonic metasurfaces might allow the realization of high-sensitivity chiral sensors and prompts the design of advanced macroscopic optical devices operating with polarized light.
Dynamics and stress relaxation of bidisperse polymer melts with unentangled and moderately entangled chains
Authors: Adeyemi Oluseye , Zhu Shiping , Xi Li
Published: June 2021

Polydispersity is inevitable in industrially produced polymers. Established theories of polymer dynamics and rheology, however, were mostly built on monodisperse linear polymers. Dynamics of polydisperse polymers is yet to be fully explored—specifically how chains of different lengths affect the dynamics of one another in a mixture. This study explored the dynamics of bidisperse polymer melts using molecular dynamics and a bead–spring chain model. Binary mixtures between a moderately entangled long-chain species and an unentangled or marginally entangled short-chain species were investigated. We found that adding short chains can significantly accelerate the dynamics of the long chains by substantially lessening their extent of entanglement. Meanwhile, although introducing long chains also hinders the motion of the short chains, it does not qualitatively alter the nature of their dynamics—unentangled short chains still follow classical Rouse dynamics even in a matrix containing entangled chains. Detailed Rouse mode analysis was used to reveal the effects of entanglement at chain segments of different scales. Stress relaxation following a step shear strain was also studied, and semi-empirical mixing rules that predict the linear viscoelasticity of polydisperse polymers based on that of monodisperse systems were evaluated with simulation results.
Torricelli's curtain: Morphology of horizontal laminar jets under gravity
Authors: Tramis O. , Merlin-Anglade E. , Paternoster G. , Rabaud M. , Ribe N. M.
Published: June 2021

Viscous fluid exiting a long horizontal circular pipe develops a complex structure comprising a primary jet above and a smaller secondary jet below with a thin fluid curtain connecting them. We present here a combined experimental, theoretical, and numerical study of this “Torricelli's curtain” phenomenon, focusing on the factors that control its morphology. The dimensional parameters that define the problem are the pipe radius a; the mean exit velocity U of the fluid; the gravitational acceleration g; and the fluid's density ρ, kinematic viscosity ν, and coefficient of surface tension γ. Rescaling of experimentally measured trajectories of the primary and secondary jets using a for the vertical coordinate and LD=U(a/g)1/2 for the horizontal coordinate x collapses the data onto universal curves for x<10LD. We propose a theoretical model for the curtain in which particle trajectories result from the composition of two motions: a horizontal component corresponding to the evolving axial velocity profile of an axisymmetric viscous jet and a vertical component due to free fall under gravity. The model predicts well the trajectory of the primary jet, but somewhat less well that of the secondary jet. We suggest that the remaining discrepancy may be explained by surface tension-driven (Taylor–Culick) retraction of the secondary jet. Finally, direct numerical simulation reveals recirculating “Dean” vortices in vertical sections of the primary jet, placing Torricelli's curtain firmly within the context of flow in curved pipes.
Evolutionary and phylogenetic insights from a nuclear genome sequence of the extinct, giant, “subfossil” koala lemurMegaladapis edwardsi
Authors: Marciniak Stephanie , Mughal Mehreen R. , Godfrey Laurie R. , Bankoff Richard J. , Randrianatoandro Heritiana , Crowley Brooke E. , Bergey Christina M. , Muldoon Kathleen M. , Randrianasy Jeannot , Raharivololona Brigitte M. , Schuster Stephan C. , Malhi Ripan S. , Yoder Anne D. , Louis Edward E. , Kistler Logan , Perry George H.
Published: June 2021

Significance

Based on “subfossil” skeletal remains it is known that multiple now-extinct giant lemur (primate) species with estimated body masses of up to ∼160 kg survived on Madagascar into the past millennium. In this study, we used ancient DNA methods to sequence the nuclear genome of one of these megafaunal lemurs,Megaladapis edwardsi(∼85 kg). With the power of the nuclear genome, we robustly resolved the phylogenetic relationship betweenMegaladapisand other lemurs, which had been a lingering uncertainty. We also identified multiple signatures of past positive natural selection across theM. edwardsigenome that support reconstructions of this taxon as a large-bodied, specialized folivore.
Immunogenicity and efficacy of the COVID-19 candidate vector vaccine MVA-SARS-2-S in preclinical vaccination
Authors: Tscherne Alina , Schwarz Jan Hendrik , Rohde Cornelius , Kupke Alexandra , Kalodimou Georgia , Limpinsel Leonard , Okba Nisreen M. A. , Bošnjak Berislav , Sandrock Inga , Odak Ivan , Halwe Sandro , Sauerhering Lucie , Brosinski Katrin , Liangliang Nan , Duell Elke , Jany Sylvia , Freudenstein Astrid , Schmidt Jörg , Werner Anke , Gellhorn Serra Michelle , Klüver Michael , Guggemos Wolfgang , Seilmaier Michael , Wendtner Clemens-Martin , Förster Reinhold , Haagmans Bart L. , Becker Stephan , Sutter Gerd , Volz Asisa
Published: June 2021

Significance

The highly attenuated vaccinia virus MVA is licensed as smallpox vaccine; as a vector it is a component of the approved adenovirus-MVA–based prime-boost vaccine against Ebola virus disease. Here, we provide results from testing the COVID-19 candidate vaccine MVA-SARS-2-S, a poxvirus-based vector vaccine that proceeded to clinical evaluation. When administered by intramuscular inoculation, MVA-SARS-2-S expresses and safely delivers the full-length SARS-CoV-2 S protein, inducing balanced SARS-CoV-2–specific cellular and humoral immunity, and protective efficacy in vaccinated mice. Substantial clinical experience has been gained with MVA vectors using homologous and heterologous prime-boost applications, including the immunization of children and immunocompromised individuals. Thus, MVA-SARS-2-S represents an important resource for developing further optimized COVID-19 vaccines.
Lateral gate dynamics of the bacterial translocon during cotranslational membrane protein insertion
Authors: Mercier Evan , Wang Xiaolin , Maiti Manisankar , Wintermeyer Wolfgang , Rodnina Marina V.
Published: June 2021

Significance

Membrane proteins are inserted into the phospholipid bilayer through a lateral gate in the translocon, SecYEG in bacteria, which is expected to be closed in the resting state. Here, we use single-molecule FRET to study the translocon dynamics on timescales ranging from submilliseconds to seconds. We show that the lateral gate is highly dynamic, fluctuating through a continuum of states from open to closed. The insertase YidC facilitates the insertion of transmembrane helices by shifting the fluctuations toward more open conformations. Spontaneous fluctuations allow the gate to rapidly release newly synthesized transmembrane segments into the phospholipid bilayer during ongoing translation. The results highlight the important role of rapid spontaneous fluctuations during the key step in the biogenesis of inner-membrane proteins.
Exploring how Hospitalization Can Alter Hepatitis C Virus Treatment Prioritization and Trajectories in People who Use Drugs: A Qualitative Analysis
Authors: Levander Ximena A. , Vega Taylor A. , Seaman Andrew , Korthuis P. Todd , Englander Honora
Published: June 2021

Background: People who use drugs (PWUD) have high rates of hepatitis C virus (HCV) infection. Hospitalization can be a time for PWUD to engage in addiction treatment, but little is known about how hospitalization shapes HCV treatment readiness. We aimed to describe how hospitalization and addiction medicine consult service (AMCS) can alter HCV prioritization of inpatient PWUD with HCV. Methods: We conducted a qualitative study consisting of semi-structured interviews ( n = 27) of hospitalized adults with addiction and HCV infection seen by an AMCS at a single, urban, academic center. Interviews were audio-recorded, transcribed, and coded iteratively at the semantic level, and analyzed for themes. Results: Of the 27 participants, most identified as Caucasian (85%), male gender (67%), and they primarily used opioids (78%); approximately half (48%) reported HCV diagnosis over 5 years ago. We identified three main themes around hospitalization altering the prioritizations and HCV treatment preferences for PWUD: (1) HCV treatment non-engaged (2) HCV treatment urgency, and (3) HCV treatment in the future. Those wanting to treat HCV—whether urgently or in the future—shared the overlapping theme of hospitalization as a reachable moment for their addiction and HCV. These participants recognized the long-term benefits of addressing HCV and connected their hospitalization to substance use. Conclusion: In our study, PWUD with HCV expressed varying and competing priorities and life circumstances contributing to three main HCV treatment trajectories. Our results suggest ways hospitalization can serve as an HCV touchpoint for PWUD, especially in the context of addressing substance use, and could be used when designing and implementing targeted interventions to improve the HCV care continuum for PWUD.
Bro1 stimulates Vps4 to promote intralumenal vesicle formation during multivesicular body biogenesis
Authors: Tseng Chun-Che , Dean Shirley , Davies Brian A. , Azmi Ishara F. , Pashkova Natalya , Payne Johanna A. , Staffenhagen Jennifer , West Matt , Piper Robert C. , Odorizzi Greg , Katzmann David J.
Published: June 2021

Endosomal sorting complexes required for transport (ESCRT-0, -I, -II, -III) execute cargo sorting and intralumenal vesicle (ILV) formation during conversion of endosomes to multivesicular bodies (MVBs). The AAA-ATPase Vps4 regulates the ESCRT-III polymer to facilitate membrane remodeling and ILV scission during MVB biogenesis. Here, we show that the conserved V domain of ESCRT-associated protein Bro1 (the yeast homologue of mammalian proteins ALIX and HD-PTP) directly stimulates Vps4. This activity is required for MVB cargo sorting. Furthermore, the Bro1 V domain alone supports Vps4/ESCRT–driven ILV formation in vivo without efficient MVB cargo sorting. These results reveal a novel activity of the V domains of Bro1 homologues in licensing ESCRT-III–dependent ILV formation and suggest a role in coordinating cargo sorting with membrane remodeling during MVB sorting. Moreover, ubiquitin binding enhances V domain stimulation of Vps4 to promote ILV formation via the Bro1–Vps4–ESCRT-III axis, uncovering a novel role for ubiquitin during MVB biogenesis in addition to facilitating cargo recognition.
The RNA m6A reader YTHDF2 controls NK cell antitumor and antiviral immunity
Authors: Ma Shoubao , Yan Jiazhuo , Barr Tasha , Zhang Jianying , Chen Zhenhua , Wang Li-Shu , Sun Joseph C. , Chen Jianjun , Caligiuri Michael A. , Yu Jianhua
Published: June 2021

N 6-methyladenosine (m6A) is the most prevalent posttranscriptional modification on RNA. NK cells are the predominant innate lymphoid cells that mediate antiviral and antitumor immunity. However, whether and how m6A modifications affect NK cell immunity remain unknown. Here, we discover that YTHDF2, a well-known m6A reader, is upregulated in NK cells upon activation by cytokines, tumors, and cytomegalovirus infection. Ythdf2 deficiency in NK cells impairs NK cell antitumor and antiviral activity in vivo. YTHDF2 maintains NK cell homeostasis and terminal maturation, correlating with modulating NK cell trafficking and regulating Eomes, respectively. YTHDF2 promotes NK cell effector function and is required for IL-15–mediated NK cell survival and proliferation by forming a STAT5–YTHDF2 positive feedback loop. Transcriptome-wide screening identifies Tardbp to be involved in cell proliferation or survival as a YTHDF2-binding target in NK cells. Collectively, we elucidate the biological roles of m6A modifications in NK cells and highlight a new direction to harness NK cell antitumor immunity.
On the periphery of university physics: trainee physics teachers’ experiences of learning undergraduate physics
Authors: Larsson Johanna , Airey John
Published: June 2021

High school physics teachers have a difficult job to do. On the one hand, they are charged with contributing to the creation of a scientifically literate society, while on the other they play a pivotal role in the recruitment of future physicists. Given the importance of this dual role, one might expect that the training of future physics teachers would be a priority for any physics department. However, research suggests that this is often not the case. While concerns have been raised about future physics teachers’ understanding of physics content, less work has focussed on the sociocultural experiences of the learning environments trainees meet when learning undergraduate physics. This case study examines how a sample of trainee physics teachers perceive learning undergraduate physics content together with engineering and physics bachelor students in a large, high-status, research-oriented physics department. The findings aim to be of interest to physics lecturers when examining their own practice. We interviewed 17 trainee physics teachers about their experiences of learning undergraduate physics, how they perceived the relevance of their physics courses for their future role as teachers, and how this affected their physics learning. Here, we identified four central themes of the students’ experiences: (1) teacher programme invisibility, (2) passive classroom culture, (3) perceived relevance of physics courses, and (4) no incentive to do well in physics. We discuss how this study illustrates the potential struggles trainee physics teachers may encounter when learning undergraduate physics. We also suggest how our findings may be used to inform the practice of university physics lecturers who come in contact with trainee physics teachers, and comment on the structure and organization of physics teacher education as a whole.
Implementation of a triage monitoring program for internal exposure to short-lived radionuclides in Israel—challenges and recommendations
Authors: Shukrun R H , Epstein L , Koch J , Benmaman D , Buchbinder L , Cohen S , Veinguer M , Datz H
Published: June 2021

Monitoring internal exposure to short-lived radionuclides is challenging, due to the frequent measurements required. ISO Standard 16 637 and the Swiss Personal Dosimetry Ordinance describe a screening measurement (triage monitoring) conducted in the workplace to identify workers suspected of internal exposure. Based on a previous study that examined the feasibility of using several commonly found radiation monitors in Israel in a triage monitoring program, we conducted a pilot study towards the implementation of triage monitoring in nuclear medicine facilities in Israel. The pilot study was conducted while considering the current Israeli regulations and local safety culture. We implemented the triage monitoring program in three nuclear medicine facilities in Israel, with a total of 55 monitored workers. The pilot study consisted of two stages: a short-term stage conducted in the largest manufacture of radiopharmaceuticals in Israel and a long-term stage in two nuclear medicine departments in Israel. During the first stage of the study, participants were asked to conduct a daily measurement at the end of the workday and send a urine sample to the national internal dosimetry laboratory. The second stage lasted 5 months in a major hospital and 18 months in a regional hospital. The workers were asked to perform the measurement at the end of the shift and send a urine sample if a defined threshold had been crossed. The mean participation rate in the long-term stage (>70%) indicates that implementation of the triage monitoring program could be successful in Israel. Based on the findings of the study, practical recommendations are listed: suitable monitoring devices, allocating a monitoring location, time of measurement, training of the workers, record keeping and coordination with a certified dosimetry laboratory. The pilot study recommendations were submitted to the Israel Institute for Occupational Safety and Hygiene at the Ministry of Labor, Social Affairs and Social Services.
Overview of epidemiological studies of nuclear workers: opportunities, expectations, and limitations
∗
Authors: Wakeford Richard
Published: June 2021

Epidemiological studies of those exposed occupationally to ionising radiation offer an important opportunity to directly check the assumptions underlying the international system of radiological protection against low-level radiation exposures. Recent nuclear worker studies, notably the International Nuclear Workers Study (INWORKS) and studies of the Mayak workforce in Russia, provide powerful investigations of a wide range of cumulative photon doses received at a low dose-rate over protracted periods, and broadly confirm radiation-related excess risks of leukaemia and solid cancers at around the levels predicted by standard risk models derived mainly from the experience of the Japanese atomic-bomb survivors acutely exposed principally to gamma radiation. However, the slope of the dose-response for solid cancers expressed in terms of the excess relative risk per unit dose, ERR/Gy, differs between INWORKS and Mayak, such that when compared with the slope derived from the atomic-bomb survivors, INWORKS does not provide obvious support for the use in radiological protection of a dose and dose-rate effectiveness factor greater than one whereas the Mayak workforce apparently does. This difference could be a chance effect, but it could also point to potential problems with these worker studies. Of particular concern is the adequacy of recorded doses received in the early years of operations at older nuclear installations, such as the potential for ‘missed’ photon doses. A further issue is how baseline cancer rates may influence radiation-related excess risks. There is scope for a considerable increase in the statistical power of worker studies, with longer follow-up capturing more deaths and incident cases of cancer, and further workforces being included in collaborative studies, but the difficulties posed by dosimetry questions should not be ignored and need to be the subject of detailed scrutiny.
Growth rates of orbits in non-periodic twist maps and a theorem by Neishtadt
Authors: Kunze Markus , Ortega Rafael
Published: June 2021

We consider non-periodic holomorphic twist maps of the form

θ

1

=
θ
+

1

r

α

(

γ
+

F

1

(

θ
,
r

)

)

,

r

1

=
r
+

r

1
−
α

F

2

(

θ
,
r

)

,

for α ∈ ]0, 1[ and

γ
∈
R
\

0

. Under appropriate assumptions on F
1, F
2 and a primitive

h

of r
1 dθ
1 − r dθ it is shown that

r

n

=
O

(

(

log

n

)

1
/
α

)

, if

(

θ

n

,

r

n

)

n
∈

N

0

is a forward complete real orbit of the map.
Random composition of L-S-V maps sampled over large parameter ranges
Authors: Bose Christopher , Quas Anthony , Tanzi Matteo
Published: June 2021

Liverani–Saussol–Vaienti (L–S–V) maps form a family of piecewise differentiable dynamical systems on [0, 1] depending on one parameter

ω
∈

R

+

. These maps are everywhere expanding apart from a neutral fixed point. It is well known that depending on the amount of expansion close to the neutral point, they have either an absolutely continuous invariant probability measure and polynomial decay of correlations (ω < 1), or a unique physical measure that is singular and concentrated at the neutral point (ω > 1). In this paper, we study the composition of L–S–V maps whose parameters are randomly sampled from a range in

R

+

, and where these two contrasting behaviours are mixed. We show that if the parameters ω < 1 are sampled with positive probability, then the stationary measure of the random system is absolutely continuous; the annealed decay rate of correlations is close (or in some cases equal) to the fastest rate of decay among those of the sampled systems; and suitably rescaled Birkhoff averages converge to limit laws. In contrast to previous studies where ω ∈ [0, 1], we allow ω > 1 in our sampling distribution. We also show that one can obtain similar decay of correlation rates for

ω
∈

R

+

, when sampling is done with respect to a family of smooth, heavy-tailed distributions.
The stochastic Cahn–Hilliard equation with degenerate mobility and logarithmic potential
Authors: Scarpa Luca
Published: June 2021

We prove existence of martingale solutions for the stochastic Cahn–Hilliard equation with degenerate mobility and multiplicative Wiener noise. The potential is allowed to be of logarithmic or double-obstacle type. By extending to the stochastic framework a regularization procedure introduced by Elliott and Garcke in the deterministic setting, we show that a compatibility condition between the degeneracy of the mobility and the blow-up of the potential allows to confine some approximate solutions in the physically relevant domain. By using a suitable Lipschitz-continuity property of the noise, uniform energy and magnitude estimates are proved. The passage to the limit is then carried out by stochastic compactness arguments in a variational framework. Applications to stochastic phase-field modelling are also discussed.
Asymptotic estimates for an integral equation in theory of phase transition
Authors: Chen Qinghua , Lei Yutian
Published: June 2021

In this paper, we study the asymptotic behavior of solutions of an integral equation of the Allen–Cahn type in

R

n

u

(

x

)

=

l

⃗

+

C

*

∫

R

n

u

(

y

)

(

1
−
|
u

(

y

)

|

2

)

|
1
−
|
u

(

y

)

|

2

|

p
−
2

|
x
−
y

|

n
−
α

d
y

, when |x| → ∞. Here

u
:

R

n

→

R

k

is uniformly continuous, and k ⩾ 1, n ⩾ 2, α ∈ (0, n) and

p
−
1
>

n

n
−
α

. In addition,

l

⃗

∈

R

k

is a constant vector and C
* is a real constant. If

1
−
|
u

|

2

∈

L

s

(

R

n

)

for some s ∈ [1, ∞), we know that |u| → 1 when |x| → ∞. Furthermore, we prove that if

1
−
|
u

|

2

∈

L

s

(

R

n

)

for some

s
∈

[

1
,

n

α

(

p
−
1

)

)

, then

u
→

l

⃗

when |x| → ∞, and hence

|

l

⃗

|
=
1

. When

1
−
|
u

|

2

∈

L

s

(

R

n

)

for some

s
∈

[

1
,

n

α

(

p
−
2

)

)

, then there exists some positive constant C such that |1 − |u(x)|2| ⩽ C|x|
α−n
for large |x|. Here the Harnack type estimate and the regularity lifting lemma come into play in those proofs.
Multiple timescales and the parametrisation method in geometric singular perturbation theory
Authors: Lizarraga Ian , Rink Bob , Wechselberger Martin
Published: June 2021

We present a novel method for computing slow manifolds and their fast fibre bundles in geometric singular perturbation problems. This coordinate-independent method is inspired by the parametrisation method introduced by Cabré, Fontich and de la Llave. By iteratively solving a so-called conjugacy equation, our method simultaneously computes parametrisations of slow manifolds and fast fibre bundles, as well as the dynamics on these objects, to arbitrarily high degrees of accuracy. We show the power of this top-down method for the study of systems with multiple (i.e. three or more) timescales. In particular, we highlight the emergence of hidden timescales and show how our method can uncover these surprising multiple timescale structures. We also apply our parametrisation method to several reaction network problems.
Experimental investigation on drag reduction in a turbulent boundary layer with a submerged synthetic jet
Authors: Li Biao-Hui , Wang Kang-Jun , Wang Yu-Fei , Jiang Nan
Published: June 2021

This work investigates the active control of a fully developed turbulent boundary layer by a submerged synthetic jet actuator. The impacts of the control are explored by measuring the streamwise velocities using particle image velocimetry, and reduction of the skin-friction drag is observed in a certain range downstream of the orifice. The coherent structure is defined and extracted using a spatial two-point correlation function, and it is found that the synthetic jet can efficiently reduce the streamwise scale of the coherent structure. Proper orthogonal decomposition analysis reveals that large-scale turbulent kinetic energy is significantly attenuated with the introduction of a synthetic jet. The conditional averaging results show that the induction effect of the prograde vortex on the low-speed fluid in a large-scale fluctuation velocity field is deadened, thereby suppressing the bursting process near the wall.
First neutron Bragg-edge imaging experimental results at CSNS*
Authors: Chen Jie , Tan Zhijian , Liu Weiqiang , Deng Sihao , Wang Shengxiang , Wang Liyi , Zheng Haibiao , Lu Huaile , Shen Feiran , Hao Jiazheng , Zhou Xiaojuan , Zhou Jianrong , Sun Zhijia , He Lunhua , Liang Tianjiao
Published: June 2021

The neutron Bragg-edge imaging is expected to be a new non-destructive energy-resolved neutron imaging technique for quantitatively two-dimensional or three-dimensional visualizing crystallographic information in a bulk material, which could be benefited from pulsed neutron source. Here we build a Bragg-edge imaging system on the General Purpose Powder Diffractometer at the China Spallation Neutron Source. The residual strain mapping of a bent Q235 ferrite steel sample has been achieved with a spectral resolution of 0.15% by the time-of-flight neutron Bragg-edge imaging on this system. The results show its great potential applications in materials science and engineering.
Observation of the BEC-BCS crossover in a degenerate Fermi gas of lithium atoms
Authors: Yan Xiang-Chuan , Sun Da-Li , Wang Lu , Min Jing , Peng Shi-Guo , Jiang Kai-Jun
Published: June 2021

We observe characteristic atomic behaviors in the Bose–Einstein-condensation-Bardeen–Cooper–Schrieffer (BECBCS) crossover, by accurately tuning the magnetic field across the Feshbach resonance of lithium atoms. The magnetic field is calibrated by measuring the Zeeman shift of the optical transition. A non-monotonic anisotropic expansion is observed across the Feshbach resonance. The density distribution is explored in different interacting regimes, where a condensate of diatomic molecules forms in the BEC limit with the indication of a bimodal distribution. We also measure the three-body recombination atom loss in the BEC-BCS crossover, and find that the magnetic field of the maximum atom loss is in the BEC limit and gets closer to the Feshbach resonance when decreasing the atom temperature, which agrees with previous experiments and theoretical prediction. This work builds up a controllable platform for the study on the strongly interacting Fermi gas.
Geodesic acoustic modes in magnetic confinement devices
Authors: Conway G.D. , Smolyakov A.I. , Ido T.
Published: June 2021

Geodesic acoustic modes (GAMs) are ubiquitous oscillatory flow phenomena observed in toroidal magnetic confinement fusion plasmas, such as tokamaks and stellarators. They are recognized as the non-stationary branch of the turbulence driven zonal flows which play a critical regulatory role in cross-field turbulent transport. GAMs are supported by the plasma compressibility due to magnetic geodesic curvature—an intrinsic feature of any toroidal confinement device. GAMs impact the plasma confinement via velocity shearing of turbulent eddies, modulation of transport, and by providing additional routes for energy dissipation. GAMs can also be driven by energetic particles (so-called EGAMs) or even pumped by a variety of other mechanisms, both internal and external to the plasma, opening-up possibilities for plasma diagnosis and turbulence control. In recent years there have been major advances in all areas of GAM research: measurements, theory, and numerical simulations. This review assesses the status of these developments and the progress made towards a unified understanding of the GAM behaviour and its role in plasma confinement. The review begins with tutorial-like reviews of the basic concepts and theory, followed by a series of topic orientated sections covering different aspects of the GAM. The approach adopted here is to present and contrast experimental observations alongside the predictions from theory and numerical simulations. The review concludes with a comprehensive summary of the field, highlighting outstanding issues and prospects for future developments.
Delay distributions on encrypted real-time traffics
Authors: Ilham Dirja Nur , Suherman S , Sihombing G , Siregar Yulianta
Published: June 2021

Real-time streams are common for nowadays communication for both data and video. Real-time data communication such as chat application and telemetry, as well as real-time video communication such as video call, video conference, or monitoring video are prone to the third party attacked. End to end encryption has been considered as the most realistic solution such as applied by WhatsApp so that the transmitted data is difficult to be revealed by the attacker. Since encryption and decryption processes injected additional delay, the algorithm should be fast enough to avoid inconvenience to users. This paper examines delay distribution for encrypted real-time traffics. The simulation shows that the decryption contributed the most to the end to end delay. Decryption delay is about 4.58 times higher than encryption and transmission delay. Although assessment involves only two links, the complex network has relatively lower than the obtained decryption delay. Meanwhile, encryption contributed only about 0.2% to the overall end to end delay.
Analysis of C4.5 Algorithm of Water Quality Dataset
Authors: Mardiansyah Heru , Zarlis Muhammad , Sitompul Opim Salim
Published: June 2021

The C4.5 algorithm still has weaknesses in predicting or classifying data if a large number of classes are used which can lead to increased decision-making time. So an approach is needed to improve the performance of the C4.5 algorithm with the selected split attributes that use the application of the average gain value to help predictions. The C4.5 algorithm is one of the Decision Tree methods in the classification process using the information entropy concept. The C4.5 algorithm uses the split criteria from ID3, the Gain Ratio is a modification of the method. The ID3 algorithm uses Information Gain (IG) for the split attribute criteria, while the C4.5 algorithm with Gain Ratio (GR), where the root value comes from high gain. The conclusion of the tests that have been carried out using the Water Quality dataset in the C4.5 method has an accuracy rate of 91.30%, with a classification error rate of 8.70%. Successful implementation using the C4.5 method in predicting the Water Quality dataset.
Implementation of Steganography Modified Least Significant Bit using the Columnar Transposition Cipher and Caesar Cipher Algorithm in Image Insertion
Authors: Handrizal  , Tarigan Jos Timanta , Putra Doni Irwansyah
Published: June 2021

Steganography technique is a technique to hide data or information into other media such as digital images, text, sound, or video. One of the simplest methods of Steganography in the concept of Steganography is the Least Significant Bit. The Least Significant Bit (LSB) method hides the message by inserting the message at the lower or rightmost bits in the cover work file as a medium to hide the message. Caesar Cipher is one method that replaces each letter in the plaintext with letters that are at odds with certain numbers in the alphabet. Columnar transposition Cipher is one method in which messages are written in rows of a specified length, then are read column by column in the order of reading based on a keyword. The message is inserted into the cover image with the target pixel determination to be inserted based on the results of the Caesar Cipher process of the Columnar Transposition Cipher index to the random value of the Multiply With Carry Generator algorithm. The system implementation uses the C# programming language. The results of this study indicate that the implementation of a combination of Caesar Cipher, Columnar Transposition Cipher, and Multiply With Carry Generator can maintain the confidentiality, integrity, and security of data.
Data science: A Review towards the Big Data Problems
Authors: Nasution Mahyuddin K.M. , Sitompul Opim Salim , Elveny Marischa , Syah Rahmad
Published: June 2021

Data science is the naming of science that can change when dealing with its subject, big data, into big data science. Extraction as the main task of and based on the definition of data science requires an interpretive way of big data. This interpretation follows the characteristics of big data, namely a review of several problems that arise concerning the characters of big data is as an approach. The goal is that data and information, in information extraction or knowledge extraction from the information space, can well organize as is the case in social networks. This paper aims to provide a brief description of it.
Evaluation of the Factors Influencing the Trust of Millennial Citizens in E-Government
Authors: Assegaff S , Andrianti A , Astri L Y
Published: June 2021

This study aims at identifying the effect of the millennial generation’s perceptions regarding risks, security, and trust in the Internet when utilizing e-government services. A total of 291 data items were collected through online surveys and this information was analysed quantitatively with the SEM method by employing the Smart PLS application. The confidence of this generation in applications is observed to be influenced by software quality and trust in the internet, but not information quality and faith in the government. Furthermore, trust in the internet is unaffected by internal risk, while the intention to use this medium is influenced by reliance on applications and also affected user behaviour.
Re-programming Electronic Control Unit for Increase Torque and Power a Motorcycle
Authors: Kamil I , Soeharwinto  , Fachrizal F
Published: June 2021

This research aims to determine the performance difference of using a standard electronic control unit (ECU) compared to re-programming the ECU of a motorcycle. The experiment was carried out on a Honda CRF 150cc motorcycle manufactured in 2018. The research methods are experimental research and use descriptive statistic method. Research findings inform that the maximum torque of the standard ECU is 13.7 Nm at 4700 rpm, and the maximum power is 9.2 KW at 7000 rpm. The re-programming ECU has a maximum torque of 17.1 Nm at 5700 rpm, and a maximum power of 12.1 kW at 7200 rpm. The apparent increase in torque is around 80.11 % and in power is around 76 %. It can be concluded that the re-programming ECU provides a more optimized engine performance on a CRF150L motorcycle.
Factors Affecting Players to Pay Online Games
Authors: Tjhin V U , Hendratno S P
Published: June 2021

This paper aimed to investigate the behavior of online game players. Even though online games have experienced rapid development in the community, it is still difficult to convince online gamers in developing countries to pay for the privilege of playing these games. This study focuses on three factors that influence the intention in paying for online games, namely fun, fantasy, and challenge. The respondents surveyed reached 1278 players of Arena of Valor (AOV) in Indonesia. The data were analyzed with Structural Equation Modeling with a Partial Least Square (PLS) approach using SmartPLS. This research developed four hypotheses. The results can be summarized as follows. First, fun has a significant impact on intention to pay. Second, fantasy has a significant impact on intention to pay. Third, challenge has a significant impact on intention to pay. Fourth, fun, fantasy, and challenge have a significant impact on intention to pay. The variable of fun has the greatest influence on intention to pay compared to the variable of fantasy and challenge. A gamer’s feeling has a greater influence on a player’s intention to pay for the game being played. Online game companies need to pay attention to aspects related to fun, so gamers have better judgment for the decision to pay for the game being played.
Implementation of Image Security using Elliptic Curve Cryptography RSA Algorithm and Least Significant Bit Algorithm
Authors: Handrizal  , Herriyance  , Hanayong J , Zarlis M , Sihombing P
Published: June 2021

Data exchange is a very important thing in today’s technological development. Two important factors must be considered in the process of data exchange, namely speed and security. Rapid technological development can result in insecure data because it can be stolen or manipulated by people who are not privileged. Thus, we need a way or method to be able to overcome these problems, such as cryptography and steganography. The Rivest-Shamir-Adleman or RSA algorithm is an asymmetric cryptographic algorithm that uses 2 prime numbers to generate a public key and a private key that is used in the encryption process for the data. The ECC concept is used to determine the seed or initial value in the generation of prime numbers in the RSA Algorithm by using point addition and multiplication in an elliptic curve. The Least Significant Bit Algorithm is a Steganography Algorithm that inserts bits from the message at the last bit in a cover, replacing the last bit. The parameter used is Running Time in steganography. The results of the research show that image files can be hidden in another image file and returned to normal with a combination of cryptography and steganography with an average Running Time for the insertion process of 3090.167 ms and the extraction process of 2917.167 ms.
Diagnosis of Facial Skin Disease in Expert System Using Fuzzy Sugeno Method
Authors: Hardi S M , Siregar D P D , Elviwani
Published: June 2021

Structure of human skin is the largest structure in the human body. Skin has many function for human body. The importance of skin care is done to provide beauty to the skin, especially facial skin care, how important facial care can be seen by number of beauty clinics that are used to help treat skin beauty. Various kinds of facial skin problems, one of problem were facial acne which can interfere with beauty of facial skin. Most people oftenly uneducated how to treat acne which is often inappropriate. Usually, sufferers will go directly to the doctor or beauty clinic. Problem often occurs is high cost of consulting with experts and long distance between user’s location and nearest doctor’s clinic, so needed an application that can help users to be able to consult about skin diseases on the face. In these researches, researchers focused on problem of acne on facial skin by implementing an expert system using Sugeno fuzzy method. Results obtained from these researches is kind of acne and severity based on the symptoms input by user. This application expert system implemented with mobile app and having an accuracy rate of 75% from 100% by testing results of experts and results by system.
Identification of Lung Cancer on Chest X-Ray (CXR) Medical Images Using the Probabilistic Neural Network Method
Authors: Syahputra M F , Rahmat R F , Rambe R
Published: June 2021

The high death rate from lung cancer is caused by the late detection or detection of cancer in the body so that treatment is carried out after the cancer has entered a high stage of severity. Meanwhile, lung cancer is a disease that requires fast and targeted treatment. One of the diagnoses of lung cancer can be done through a chest X-ray (CXR) and the results can only be read by an expert such as a doctor. In many cases, the doctor’s diagnosis takes time and is still possible for errors. With increasingly sophisticated knowledge, several diseases can be identified by image analysis, including lung cancer. Digital image processing and methods and neural networks can help identify cancer. The method proposed in this study is a probabilistic neural network to identify normal and cancer images from lung images in lung cancer detection. The identification stage consists of several stages, namely preprocessing, segmentation with canny edge detection, feature extraction with the Gray Level Co-Ocorrence Matrix (GLCM) and identification with a Probabilistic Neural Network (PNN). With the method used, the accuracy of the lung cancer identification results was 93.33%.
Implementation of Not So Naive and Burkhard-Keller Tree algorithms in Indonesian-Hokkien dictionary application
Authors: Budiman M A , Rachmawati D , Charity
Published: June 2021

In Indonesia, especially in Medan, North Sumatra, Hokkien is used in everyday life within the Chinese community. However, learning the language is still done manually. Therefore, the authors intend to create an Android-based Hokkien dictionary application. The most common typing errors found were deleting and inserting single characters, substituting and reversing adjacent characters. Exact string matching can perform a quick search, but the search will fail when the incorrect input is entered. This study aims to prove the advantages and disadvantages of each algorithm in accessing information in addition to displaying the results of the running time of both algorithms. The results showed that the search time for the Burkhard-Keller Tree algorithm increased by 72% and 96% for the Not So Naive algorithm when searching on a database containing 200 words and 400 words. The Not So Naive algorithm has a mean running time of 26.9 ms and a mean running time of 53.5 ms on the Burkhard-Keller Tree algorithm.
Maple as a tool to understand marketing game for up to four companies
Authors: Zahedi  , Affandi Marwan , Suparni  , Suzana Yenny , Razi Fachrur
Published: June 2021

In business environment, advertisement is very important. Companies spent a lot of money to advertise their products. When there are several players which have the same product to market, the competition will be quite tough since the market size is finite. The amount of the money spent for advertisement will affect the sale of the product. The profit for each company will depend on the amount of money spent for advertisement. However, this will also depend on the money spent by other companies, making the determination of the optimum profit become difficult. For two and three companies, exact value of the optimum profit for each company can be found. However, the analysis for more than three companies is quite complicated so we must resort to numerical method. Examples for the cases of two, three and four companies are given. A company with the smallest effectiveness factor and gross profit will have the smallest optimum profit. Maple has been widely used to derive formulas and to solve the case studies in this paper.
A cryptocompression system with Multi-Factor RSA algorithm and Levenstein code algorithm
Authors: Budiman M A , Sihombing P , Fikri I A
Published: June 2021

Exchanging digital messages by electronic means has a major security concern. The data being sent can be accessed and read by some unintended parties if there is no security system involved. Cryptography obscures the messages being sent and they can only be read by intended recipients by using the right key. Using asymetric cryptography algorithm such as Multi-Factor RSA may help to obscure a message with high security; however, the ciphertext is usually much larger than the message so it takes much more time to transmit. In order to solve this problem, this research combines the Multi-Factor RSA with the Levenstein Code algorithm in a cryptocompression system to compress the size of the message being sent. This research also compares encrypt-then-compress scheme with compress-then-encrypt scheme. The result shows that encrypt-then-compress scheme has a better compression ratio than the compress-then-encrypt scheme. On the contrary, in terms of actual time performance, the compress-then-encrypt scheme is faster than encrypt-then-compress scheme.
Design and Implementation of IoT based Automated Tomato Watering System Using ESP8266
Authors: Nurhasanah Rossy , Savina Lira , Nata Zul Mahadi , Zulkhair Ilham
Published: June 2021

Tomatoes need a proper watering system in order to grow and provide optimal yields. The factors that must be considered in watering the tomatoes are soil moisture and air temperature. The soil moisture needed for planting tomatoes is between 60% to 80% with a temperature rate between 24 to 28 degrees Celsius. We propose to implement an IoT based agricultural technology innovation to address the problem of precise watering system based on soil moisture and air temperature rate, which can be controlled remotely via internet connection. This system was designed and assembled using ESP8266 with soil moisture sensor and DHT11. This system was also programmed to be controlled using the Telegram Messenger application. The data read by the sensor could be seen through the Telegram Bot and do watering the plants automatically or manually. Based on several experiments conducted in this study, the system could do watering as well as maintain and control soil moisture and air temperature properly. By using this system, it will be easier for farmers to control and maintain tomato plants from anywhere and anytime through the Telegram Messenger.
An implementation of Rabin-p cryptosystem and affine cipher in a hybrid scheme to secure text
Authors: Budiman M A , Handrizal  , Azzahra S
Published: June 2021

One way to keep digital information secure is by using cryptographic techniques. With respect to its keys, cryptography generally is divided into two types: symmetric and asymmetric. Symmetric cryptography algorithm uses the same key in both encryption and decryption while asymmetric uses different keys for each of these processes. Asymmetric cryptography algorithm is known to be ineffective to encrypt big messages since it takes more CPU time to do the computation and the resulting ciphertext is usually much bigger than the original message. To eliminate these problems, in this research, we combine Rabin-p cryptosystem, an asymmetric cryptography algorithm, and affine cipher, a symmetric cryptography algorithm, in a hybrid scheme in order to secure messages from unwanted parties. The affine cipher is used for message encryption while Rabin-p is used for affine cipher’s key encryption. The result of this research is a hybrid cryptography scheme that can encrypt and decrypt message in the form of *.pdf files and be able to restore the message without losing integrity.
Social network extraction based on Web: A Review about Supervised Methods
Authors: Nasution Mahyuddin K. M. , Noah Shahrul Azman
Published: June 2021

The extraction of social networks from specific sources of information is essential. It relates to the disclosure of social structures with prevailing behavior in accordance with that information source. It, of course, requires methods that are generally in a supervised stream. The method changes based on the demands of data modeling, which are generally textual, but do not rule out other types of information, such as databases or different literacy. This paper reviews the methods that have been developed and the types of information sources involved as input to the social network extraction process. This brief review follows the literature related to social network extraction involving supervised methods. Based on different information sources, there are different models in supervised stream.