bluuebunny/crossref_metadata_2025 huggingface dataset:
A combined velocity and temperature measurement with an LED and a low-speed camera
Authors: Deng Zhichao , König Jörg , Cierpka Christian
Published: July 2022

Microfluidic devices are governed by three-dimensional velocity and temperature fields, and their boundary conditions are often unknown. Therefore, a measurement technique is often desired to measure both fields in a volume. With astigmatism particle tracking velocimetry (APTV) combined with luminescence lifetime imaging, the temperature and all velocity components in a volume can be measured with one optical access. While the three-dimensional particle position is determined by evaluating the shape of the corresponding particle image, the temperature measurement relies on estimating the temperature-dependent luminescence lifetime derived from particle images on two subsequent image captures shortly after the photoexcitation. For this, typically a high-energetic pulsed laser is required to ensure a high signal-to-noise ratio. However, it can also cause additional heating of the fluid. We show that this problem is solved by replacing the pulsed laser with an LED. To compensate for the lower power provided by the LED, we adapted the timing schedule and vastly extended the illumination time and the exposure time for both image captures. In addition, we were able to replace the typically used high-speed camera with an ordinary double-frame camera. In this way, very low measurement uncertainties on all measured quantities can be achieved while keeping the temperature of the fluid unaffected. Random errors dominate within the two focal planes of APTV, yielding a standard deviation of the temperature of individual particles of about 1 

∘

C

only. The measurement error caused by the movement of tracer particles during the much longer illumination and exposure time were found to be acceptable when the measured velocity is low. With the circumvention of light-source induced heating and the lower cost of hardware devices, the adapted approach is a suitable measurement technique for microfluidic related research.
An accurate orientation measurement system of self-propelled artillery barrel based on coordinate system mapping
Authors: Cheng Zejun , Wang Huaiguang , Han Lanyi , Du Binhan , Shi Zhiyong
Published: July 2022

Barrel orientation accuracy is an essential factor affecting the hit rate of self-propelled artillery, which comprehensively reflects the working state of the self-propelled artillery fire control system. An accurate self-propelled artillery orientation measurement system based on the coordinate system mapping is proposed to reduce the axis simulation error and introduce the north datum. The measurement system uses Radio Navigation Satellite System orientation technology to determine the measurement area’s standard north orientation. Based on the standard north orientation, a coordinate measurement system is established. The total station and self-propelled artillery positions are unified to the coordinate measurement system. The total station measures the coordinates of the marked points on the barrel. According to the coordinates of the marker points under different datums, the mapping relationship of different coordinate systems can be obtained. The total station measures the azimuth and elevation angle of the line connecting the marked points. Based on the coordinate system mapping relationship, the accurate orientation of the self-propelled artillery barrel can be calculated. The combined standard uncertainty evaluation is performed, and the uncertainties of the azimuth and elevation angles are

1.5167
×

10

−
4

 rad

and

1.6341
×

10

−
4

 rad

, respectively. A particular type of self-propelled artillery is selected for experiments. The results show that the system’s measurement accuracy can be guaranteed within

2.0944
×

10

−
4

 rad

.
On the non-chiral intermediate long wave equation
Authors: Berntson Bjorn K , Langmann Edwin , Lenells Jonatan
Published: July 2022

We study integrability properties of the non-chiral intermediate long wave equation recently introduced by the authors as a parity-invariant variant of the intermediate long wave equation. For this new equation we: (a) derive a Lax pair, (b) derive a Hirota bilinear form, (c) derive a Bäcklund transformation, (d) use, separately, the Bäcklund transformation and the Lax representation to obtain an infinite number of conservation laws.
Extraction of quasi-coherent modes based on reflectometry data
Authors: Salazar Luigui , Heuraux Stéphane , Sabot Roland , Krämer-Flecken Andreas , Supra Team Tore
Published: July 2022

The identification of turbulence sources would drive to a deeper understanding of confinement dynamics in tokamak plasmas. Turbulence results from a mixture of instabilities corresponding to sources at different timescales and spatial scales. Using poloidal correlation reflectometry and multi-pin Langmuir probe, it was shown in the T-10 and the Tokamak Experiment for Technology Oriented Research (TEXTOR) tokamaks that the reflectometry frequency spectrum is the superposition of several components: broadband component, quasi-coherent (QC) modes and low-frequency components. The relevance of QC modes is associated with their link with the trapped electron mode instability. This link was exhibited in the transition from the linear ohmic confinement (LOC) to the saturated ohmic confinement (SOC) regime. A method is presented in this paper to extract the QC mode component from the reflectometry data, enabling its separation from the broadband component and the study of its time evolution. It is a first step toward the discrimination of turbulence sources. The central idea explores a way to combine the approach of signal processing and machine learning. The continuous wavelet transform on the basis of complex Morlet wavelet has proved to be efficient in providing a decomposition of a signal at different scales over time for fluctuation tackling; clustering techniques, such as the mini-batch K-means, are able to tackle clusters at different scales. The method was applied to Tore Supra and TEXTOR reflectometry data. In Tore Supra, the amplitude of the extracted QC mode component decreases during the LOC–SOC transition. In TEXTOR, the amplitude of the coherent spectra of the extracted QC mode component is similar to the experimental coherent spectra obtained through correlation reflectometry. The developed method permits the extraction of components, preserving their physical and statistical properties.
Effects of ICRF waves to EAST LHCD discharges on intrinsic rotations
Authors: Jin Y F , Lyu B , Bae C , Zhang X J , Rice J E , Wang F D , Fu J , Liu H Q , Zhang H M , Zeng L , Chu Y Q , Zang Q , Bin B , Li Y C , He L , Lu D A , Liu H J
Published: July 2022

Ion cyclotron range of frequencies (ICRFs) have proven to efficiently serve as a toroidal rotation source in tokamak plasmas. Recent experiments on the experimental advanced superconducting tokamak show that the rotation profiles are remarkably modified when the internal inductance (l
i) changed. The comparisons of the ion and electron temperature profiles among ICRF-heated plasmas suggest that the change in l
i can remarkably affect the toroidal rotation velocity. The scaling of rotation velocity increments as a function of the change in l
i also suggests that ICRF would serve as a reliable rotation source in plasmas with larger l
i decrements.
Charged-particles measurements in low-pressure iodine plasmas used for electric propulsion
Authors: Esteves B , Marmuse F , Drag C , Bourdon A , Laguna A Alvarez , Chabert P
Published: July 2022

This paper investigates iodine as an alternative propellant for space plasma propulsion. Measurements are taken in a low-pressure inductively-coupled plasma chamber used as the ionization stage of a gridded ion-engine. Langmuir probes are used to measure the electron density and the electron energy distribution functions spatial variations between the inductive coil and the extraction grids for several radio-frequency (RF) powers and mass flow rates. Measurements in iodine are compared to xenon, krypton and argon in order to evaluate performances of these various propellants for ionization (and therefore power) efficiency. At low mass flow rates, iodine is found to be the most efficient propellant, however, as the mass flow rate increases, the ionization cost in iodine increases rapidly due to both its molecular and electronegative nature. The ratio of negative ion to electron density is measured using laser-induced photodetachment in order to quantify the effect of iodine electronegativity. Finally, all measurements are compared to a previously published global (volume-averaged) model. The agreement between model and experiments is acceptable, however several modelling improvements are proposed.
Experimental characterization of the thermo-electro-mechanical properties of a shape memory composite during electric activation
Authors: Pereira Sánchez Clara , Houbben Maxime , Fagnard Jean-Francois , Harmeling Pascal , Jérôme Christine , Noels Ludovic , Vanderbemden Philippe
Published: July 2022

This works investigates in detail the electro-thermo-mechanical properties of a shape memory composite (SMC) during shape memory cycles in which the heating is a result of resistive heating. The SMC is a covalently cross-linked poly(ϵ-caprolactone) network filled with 3 wt% of multiwall carbon nanotubes. The characterization is performed with the help of a custom-made tensile test bench that is able to couple the mechanical characterization with the thermal and electrical ones. A proportional integral controller using the lambda tuning method is used in order to control the temperature achieved by resistive heating of the SMC. The electrical resistivity of the SMC shows a non-linear and non-monotonic dependence on temperature and strain. The resistivity is also found to vary among successive shape memory cycles, suggesting that a (first) training cycle is necessary not only to stabilize the mechanical but also the electrical properties of the SMC. A fuzzy logic controller for constant load control is also used to investigate the strain variation with temperature related to the two-way shape memory effect of the SMC. The results give evidence of the strong interplay between the electrical and (thermo-)mechanical characteristics of electroactive SMCs.
Efficient and robust entanglement generation with deep reinforcement learning for quantum metrology
Authors: Qiu Yuxiang , Zhuang Min , Huang Jiahao , Lee Chaohong
Published: July 2022

Quantum metrology exploits quantum resources and strategies to improve measurement precision of unknown parameters. One crucial issue is how to prepare a quantum entangled state suitable for high-precision measurement beyond the standard quantum limit. Here, we propose a scheme to optimize the state preparation pulse sequence to accelerate the one-axis twisting dynamics for entanglement generation with the aid of deep reinforcement learning (DRL). We consider the pulse train as a sequence of π/2 pulses along one axis or two orthogonal axes, and the operation is determined by maximizing the quantum Fisher information using DRL. Within a limited evolution time, the ultimate precision bounds of the prepared entangled states follow the Heisenberg-limited scalings. These states can also be used as the input states for Ramsey interferometry and the final measurement precisions still follow the Heisenberg-limited scalings. While the pulse train along only one axis is more simple and efficient, the scheme using pulse sequence along two orthogonal axes show better robustness against atom number difference between simulation and experiment. Our protocol with DRL is efficient and easy to be implemented in state-of-the-art experiments.
Structural role of double layer amphoteric oxides forms on electrical conductivity: PbO/zinc oxide semiconductor
Authors: Akay Defne , Gökmen Uğur , Ocak Sema Bilge
Published: July 2022

We have investigated the electrical properties of PbO/Zinc Oxide double-layer semiconductor (DLS) diodes such as series resistance (Rs), ideality factor (n), and barrier height (φb). The samples were manufactured by using an evaporation technique at room temperature. To obtain their main electrical parameters, current-voltage (I–V) measurements have been performed in the dark and at room temperature. In the study, we examined two diodes to evaluate the electrical characteristics of PbO/Zinc Oxide double-layer semiconductor (DLS) diodes using the thermionic emission (TE) theory, Norde’s method, and Cheung’s functions. While n,ϕb,andI0values of Diode 1 were found to be 4.02, 0.739 eV, and 1.506. 10−8A respectively, the same values of Diode 2 were calculated as 4.14, 0.724 eV, and 2.65.10−8A, respectively, by using the TE method. The values of n,ϕb,andRswere also calculated using the Cheung’s method, and they were found to be 10.048, 0.549 eV, and 4.058kΩ,respectively, for Diode 1, while these values were calculated as 8.116, 0.659 eV, and 7.799kΩrespectively, for Diode 2.φbandRsvalues are also ascertained as0.84eVfor Diode 1 and0.80eVfor Diode 2,18.2kΩfor Diode 1 and11.1kΩfor Diode 2 using Norde Method, respectively. The forward bias I–V characteristics were used to obtain the energy distribution of the interface state density considering the effective barrier height’s bias dependence. The change observed in the interface state density’s magnitude ranged between1.4×1012and2.0×1011eV−1cm−2.The evaluated series resistance indicates the product of mobility and free carrier concentration, ideality factor is a measure of how closely the diode follows the ideal diode equation, and barrier height also depends on the concentration of carriers in PbO/Zinc Oxide double-layer semiconductors.
Characterizing spatial point processes by percolation transitions
Authors: Villegas Pablo , Gili Tommaso , Gabrielli Andrea , Caldarelli Guido
Published: July 2022

A set of discrete individual points located in an embedding continuum space can be seen as percolating or non-percolating, depending on the radius of the discs/spheres associated with each of them. This problem is relevant in theoretical ecology to analyze, e.g., the spatial percolation of a tree species in a tropical forest or a savanna. Here, we revisit the problem of aggregating random points in continuum systems (from 2 to 6-dimensional Euclidean spaces) to analyze the nature of the corresponding percolation transition in spatial point processes. This problem finds a natural description in terms of the canonical ensemble but not in the usual grand-canonical one, customarily employed to describe percolation transitions. This leads us to analyze the question of ensemble equivalence and study whether the resulting canonical continuum percolation transition shares its universal properties with standard percolation transitions, analyzing diverse homogeneous and heterogeneous spatial point processes. We, therefore, provide a powerful tool to characterize and classify a vast class of natural point patterns, revealing their fundamental properties based on percolation phase transitions.
Spherical model with Dzyaloshinskii–Moriya interactions
Authors: de Castilho William , Salinas S R
Published: July 2022

We analyze the thermodynamic behavior of a ferromagnetic mean-spherical model with three distinct spin components and the addition of Dzyaloshinkii–Moriya interactions. Exact calculations are performed for classical and quantum versions of this lattice model system. We show the onset of space modulated structures at low temperatures.
Effect of multiple scattering on diffracted transition radiation of a relativistic electron crossing a single crystal target
Authors: Blazhevich S.V. , Noskov A.V. , Fedoseev A.E.
Published: July 2022

In this paper, we study the influence of multiple scattering
of a relativistic electron on diffracted transition radiation (DTR),
which arises when this particle crosses a single-crystal target in
the Bragg scattering geometry. For this case we have obtained the
expressions describing the angular density of DTR both with and
without allowance for multiple scattering of the relativistic
electron in the target. The paper shows that the multiple scattering
leads to a significant increase in the DTR angular density at low
energies of the electron.
Hierarchical structure in the trace formula*
Authors: Keating J P
Published: July 2022

Guztwiller’s trace formula is central to the semiclassical theory of quantum energy levels and spectral statistics in classically chaotic systems. Motivated by recent developments in random matrix theory and number theory, we elucidate a hierarchical structure in the way periodic orbits contribute to the trace formula that has implications for the value distribution of spectral determinants in quantum chaotic systems.
Reliability of using LS-VCE computation in Deriving Variances for Multi-Classes Dataset
Authors: Zulkifli Akram , Abbas Mohd Azwan , Hashim Norshahrizan Mohd , Mustafar Mohamad Asrul , Abdullah Ashraf
Published: July 2022

Stochastic modelling (SM) plays an essential role in least-squares adjustment (LSA), especially for geodetic network data processing. Estimated variances derived from SM are vital factors in determining the reliability of the computed parameter vectors and ensuring the sensitivity of adjustment outcomes toward outliers. As there are multi-source of datasets consisting various of data quality, there is still room for improvement when positional accuracy becomes the main priority. Concerning the accuracy argument, legacy datasets that were exploited in establishing the National Digital Cadastral Database (NDCDB) were obtained from multi-classes of measurement (i.e., first, second and third classes). Taking into account this condition, this research has investigated the capability of stochastic modelling to preserve the positional accuracy of land records that comprehends from multi-classes data quality. To achieve that, the algorithm of Least Squares Variance Component Estimator (LSVCE) was employed in estimating realistic variances. First and second classes measurement were yielded from three (3) certified plans (CPs) which are CP93887, CP80333, and CP33758. Comparison between the adjusted results computed from the combined and separated variance according to data classes have demonstrated that combined variance can detect outliers while separated variance can give realistic adjustment results. From these outcomes, the experiments verified that a hybrid solution is needed for both data classes in order to preserve positional accuracy. In conclusion, to ensure the accuracy of survey data in the future, a proper variance component is needed to improve the coordinated cadastral database.
Walkability Index in Pasir Gudang by using GIS
Authors: Ahmad Akmal Azizi , Naharudin Nabilah
Published: July 2022

Walkability is defined as the level of comfort of an environment can be provided to people so they can walk to their destination. Walkability also supports community health, safety, liveability and reduce car dependence. Walkability is vital due to urban growth and the increased number of vehicle used. Walkable city promotes the residents to walk more in their neighbourhood. In addition to that, a walkable city promotes an active transportation in the era that seems to be very much car reliance. This study aims to measure the Walkability Index in the city of Pasir Gudang while addressing a question; i) How can the Walkability Index be measured? Hence, a new index was developed to address the question. The Walkability Index is calculated for every neighbourhood in Pasir Gudang by using the 3D criteria, Dwelling Density, Land Use Diversity, and Intersection Density. The index was classified into five categories from the lowest to the highest index.
Effects of feeding pressures on the flowfield structures of three-dimensional film cooling
Authors: Zhao Xinhai , Yi Shihe , Mi Qi , Ding Haolin , He Lin
Published: July 2022

A Mach 2.6 annular supersonic nozzle was designed to protect a hypersonic cone. The annular nozzle is able produce tangential cooling film around the cone. Experiments were carried out in a hypersonic wind tunnel under different cooling film feeding pressures and different attack angles. Temperature-sensitive paint (TSP) was used to measure surface temperature of the cone body; schlieren method was applied to visualize the flow structures. TSP results showed that cooling film can obviously decrease surface heating load, but its efficiency was influenced by the angle of attack. Schlieren results showed that the shape of upper-lip shock wave is similar to an arc, and the reflected shock wave is more closer to a straight line; both the tilt rate of upper-lip shock wave and the reflected shock wave were increased exponentially with the rise of feeding pressure; a higher feeding pressure resulted in a larger curvature of upper-lip shock wave; compared with reflected shock wave, upper-lip shock wave and shearing layer were more easily affected by the feeding pressure. With higher feeding pressure, incidence point was moved to the further downstream location, and a fitting formula is given to express the relationship between the position of the shock wave incidence point and the feeding pressure.
Color-tunable photoluminescence and persistent luminescence in a single LiYGeO4:Tb3+ phosphor
Authors: Wang Hong , Wang Xinjie , Liu Shuang , Mei Tianjian , Fan Ying , Kang Lihua , Xin Fangyun , Xing Mingming , Fu Yao , Luo Xixian , Tian Ying
Published: July 2022

Persistent luminescence (PerL) phosphors have been widely applied in many advanced applications in the field of emergency lighting, safety signage, and ornaments. Recently, the PerL phosphors based on germanates have attracted great attention owing to their excellent PerL performance. However, the design and development of excellent germanates-based PerL materials with full spectral emissions remain challenging due to the lack of color-tunable PerL, especially in the blue and green regions (400–600 nm). Herein, we develop a new type of Tb3+-activated LiYGeO4 PerL phosphor with real-time adjusting the photoluminescence (PL) and PerL color, which can be effectively excited by a 254 UV light. Both blue and green PerL are realized simultaneously in a single phosphor. When LiYGeO4:Tb3+ doped with lower concentrations of Tb3+ ions, phosphors emit blue PL and PerL. With increasing Tb3+ concentration, the PL and PerL colors of LiYGeO4:Tb3+ PerL phosphor are gradually regulated from blue to green. Besides, LiYGeO4:Tb3+ exhibits temperature-dependent luminescence property, whose PL and PerL colors can also be successively widely tuned by various temperature. This stable and tunable color in real-time PL and PerL property promote the as-designed LiYGeO4:Tb3+ phosphor to have potential applications in advanced anti-counterfeiting and display devices.
Prediction of VMAT delivery accuracy using plan modulation complexity score and log-files analysis
Authors: Viola Pietro , Romano Carmela , Craus Maurizio , Macchia Gabriella , Buwenge Milly , Indovina Luca , Valentini Vincenzo , Morganti Alessio G , Deodato Francesco , Cilla Savino
Published: July 2022

The purpose of this study was to develop a predictive model based on plan complexity metrics and linac log-files analysis to classify the dosimetric accuracy of VMAT plans. A total of 612 VMAT plans, corresponding to 1224 arcs, were analyzed. All VMAT arcs underwent pre-treatment verification that was performed by means of the dynamic log-files generated by the linac. The comparison of predicted (by TPS) and measured (by log-files) integral fluences was performed using γ-analysis in terms of the percentage of points with γ-value smaller than one (γ%) and using a stringent 2%(local)/2 mm criteria. This γ-analysis was performed by a commercial software LinacWatch. The action limits (AL) were derived from the mean values, standard deviations and the confidence limit (CL) of the γ% distribution. A plan complexity metric, the modulation complexity score (MCS), based on the aperture beam area variability and leaf sequence variability was used as input variable of the model. A binary logistic regression (LR) model was developed to classify QA results as ‘pass’ (γ% ≥ AL) or ‘fail’ (γ% < AL). Receiver operator characteristics (ROC) curves were used to determine the optimal MCS threshold to flag ‘failed’ plans that need to be re-optimized. The model reliability was evaluated stratifying the plans in training, validation and testing groups. The confidence and action limits for γ% were found 20.1% and 79.9%, respectively. The accuracy of the model for the training and testing dataset was 97.4% and 98.0%, respectively. The optimal MCS threshold value for the identification of failed plans was 0.142, providing a true positive rate able to flag the plans failing QA of 91%. In clinical routine, the use of this MCS threshold may allow the prompt identification of overly modulated plans, then reducing the number of QA failures and improving the quality of VMAT plans used for treatment.
Emerging hot spot analysis to indicate forest conservation priorities and efficacy on regional to continental scales: a study of forest change in Selva Maya 2000–2020
Authors: Cuba Nicholas , Sauls Laura A , Bebbington Anthony J , Bebbington Denise Humphreys , Chicchon Avecita , Marimón Pilar Delpino , Diaz Oscar , Hecht Susanna , Kandel Susan , Osborne Tracey , Ray Rebecca , Rivera Madelyn , Rogan John , Zalles Viviana
Published: July 2022

Despite the importance of preserving contiguous tropical forest areas to maintain biodiversity and terrestrial carbon stocks, methodological challenges continue to hinder broad-scale analysis of threats to these forests. Emerging Hot Spot Analysis (EHSA) is a spatial-statistical method that conveys complex information about the temporal dynamics of deforestation across a range of moderate to coarse spatial scales. Using Global Forest Change (GFC) data as inputs, EHSA produces spatially comprehensive, gridded outputs that represent a standardized, reproduceable way to instantiate contiguous forest tracts as spatial objects. Doing so allows aggregation of other GFC-derived values and analysis of alternative geographic configurations besides sub-national jurisdictions or protected areas, which can limit observation of finer scale variations. This paper illustrates the method’s utility to comprehensively characterize the magnitude and temporality of pressures facing the Selva Maya, a transboundary forest region with extensive areas under conservation that covers portions of Mexico, Guatemala, and Belize.
A manifold of planar triangular meshes with complete Riemannian metric
Authors: Herzog Roland , Loayza-Romero Estefanía
Published: July 2022

Shape spaces are fundamental in a variety of applications including image registration, morphing, matching, interpolation, and shape optimization. In this work, we consider two-dimensional shapes represented by triangular meshes of a given connectivity. We show that the collection of admissible configurations representable by such meshes forms a smooth manifold. For this manifold of planar triangular meshes we propose a geodesically complete Riemannian metric. It is a distinguishing feature of this metric that it preserves the mesh connectivity and prevents the mesh from degrading along geodesic curves. We detail a symplectic numerical integrator for the geodesic equation in its Hamiltonian formulation. Numerical experiments show that the proposed metric keeps the cell aspect ratios bounded away from zero and thus avoids mesh degradation along arbitrarily long geodesic curves.
The integer homology threshold in 𝑌_{𝑑}(𝑛,𝑝)
Authors: Newman Andrew , Paquette Elliot
Published: July 2022

We prove that in the

d
d

-dimensional Linial–Meshulam stochastic process the

(
d
−
1
)

(d - 1)

st homology group with integer coefficients vanishes exactly when the final maximal

(
d
−
1
)

(d - 1)

-dimensional face is covered by a top-dimensional face. This generalizes the

d
=
2

d = 2

case proved recently by Łuczak and Peled [Discrete Comput. Geom. 59 (2018), pp. 131–142] and establishes that

p
=
d
log
⁡
n

/

n

p =d \log n/n

is the sharp threshold for homology with integer coefficients to vanish in

Y
d

(
n
,
p
)

Y_d(n, p)

, answering a 2003 question of Linial and Meshulam [Combinatorica 26 (2006), pp. 475–487].
Weakly saturated hypergraphs and a conjecture of Tuza
Authors: Shapira Asaf , Tyomkyn Mykhaylo
Published: July 2022

Given a fixed hypergraph

H
H

, let

wsat
⁡
(
n
,
H
)

\operatorname {wsat}(n,H)

denote the smallest number of edges in an

n
n

-vertex hypergraph

G
G

, with the property that one can sequentially add the edges missing from

G
G

, so that whenever an edge is added, a new copy of

H
H

is created. The study of

wsat
⁡
(
n
,
H
)

\operatorname {wsat}(n,H)

was introduced by Bollobás in 1968, and turned out to be one of the most influential topics in extremal combinatorics. While for most

H
H

very little is known regarding

wsat
⁡
(
n
,
H
)

\operatorname {wsat}(n,H)

, Alon proved in 1985 that for every graph

H
H

there is a limiting constant

C
H

C_H

so that

wsat
⁡
(
n
,
H
)
=
(

C
H

+
o
(
1
)
)
n

\operatorname {wsat}(n,H)=(C_H+o(1))n

. Tuza conjectured in 1992 that Alon’s theorem can be (appropriately) extended to arbitrary

r
r

-uniform hypergraphs. In this paper we prove this conjecture.
On symmetric representations of 𝑆𝐿₂(ℤ)
Authors: Ng Siu-Hung , Wang Yilong , Wilson Samuel
Published: July 2022

We introduce the notions of symmetric and symmetrizable representations of

SL
2

⁡
(

Z

)

{\operatorname {SL}_2(\mathbb {Z})}

. The linear representations of

SL
2

⁡
(

Z

)

{\operatorname {SL}_2(\mathbb {Z})}

arising from modular tensor categories are symmetric and have congruence kernel. Conversely, one may also reconstruct modular data from finite-dimensional symmetric, congruence representations of

SL
2

⁡
(

Z

)

{\operatorname {SL}_2(\mathbb {Z})}

. By investigating a

Z

/

2

Z

\mathbb {Z}/2\mathbb {Z}

-symmetry of some Weil representations at prime power levels, we prove that all finite-dimensional congruence representations of

SL
2

⁡
(

Z

)

{\operatorname {SL}_2(\mathbb {Z})}

are symmetrizable. We also provide examples of unsymmetrizable noncongruence representations of

SL
2

⁡
(

Z

)

{\operatorname {SL}_2(\mathbb {Z})}

that are subrepresentations of a symmetric one.
On large ℓ₁-sums of Lipschitz-free spaces and applications
Authors: Candido Leandro , Guzmán Héctor
Published: July 2022

We prove that the Lipschitz-free space over a Banach space

X
X

of density

κ
\kappa

, denoted by

F

(
X
)

\mathcal {F}(X)

, is linearly isomorphic to its

ℓ
1

\ell _1

-sum

(

⨁

κ

F

(
X
)
)

ℓ
1

\left (\bigoplus _{\kappa }\mathcal {F}(X)\right )_{\ell _1}

. This provides an extension of a previous result from Kaufmann in the context of non-separable Banach spaces. Further, we obtain a complete classification of the spaces of real-valued Lipschitz functions that vanish at

0
0

over a

L

p

\mathcal {L}_p

-space. More precisely, we establish that, for every

1
≤
p
≤
∞

1\leq p\leq \infty

, if

X
X

is a

L

p

\mathcal {L}_p

-space of density

κ
\kappa

, then

L
i
p

0

(
X
)

\mathrm {Lip}_0(X)

is either isomorphic to

L
i
p

0

(

ℓ
p

(
κ
)
)

\mathrm {Lip}_0(\ell _p(\kappa ))

if

p
>
∞

p>\infty

, or

L
i
p

0

(

c
0

(
κ
)
)

\mathrm {Lip}_0(c_0(\kappa ))

if

p
=
∞

p=\infty

.
Affine Lie algebra representations induced from Whittaker modules
Authors: Cardoso Maria Clara , Futorny Vyacheslav
Published: July 2022

We use induction from parabolic subalgebras with infinite-dimensional Levi factor to construct new families of irreducible representations for arbitrary affine Kac-Moody algebras. Our first construction defines a functor from the category of Whittaker modules over the Levi factor of a parabolic subalgebra to the category of modules over the affine Lie algebra. The second functor sends tensor products of a module over the affine part of the Levi factor (in particular any weight module) and of a Whittaker module over the complement Heisenberg subalgebra to the affine Lie algebra modules. Both functors preserve irreducibility when the central charge is nonzero.
Intermediate dimensions of infinitely generated attractors
Authors: Banaji Amlan , Fraser Jonathan
Published: July 2022

We study the dimension theory of limit sets of iterated function systems consisting of a countably infinite number of contractions. Our primary focus is on the intermediate dimensions: a family of dimensions depending on a parameter

θ
∈
[
0
,
1
]

\theta \in [0,1]

which interpolate between the Hausdorff and box dimensions. Our main results are in the case when all the contractions are conformal. Under a natural separation condition we prove that the intermediate dimensions of the limit set are the maximum of the Hausdorff dimension of the limit set and the intermediate dimensions of the set of fixed points of the contractions. This builds on work of Mauldin and Urbański concerning the Hausdorff and upper box dimension. We give several (often counter-intuitive) applications of our work to dimensions of projections, fractional Brownian images, and general Hölder images. These applications apply to well-studied examples such as sets of numbers which have real or complex continued fraction expansions with restricted entries.

We also obtain several results without assuming conformality or any separation conditions. We prove general upper bounds for the Hausdorff, box and intermediate dimensions of infinitely generated attractors in terms of a topological pressure function. We also show that the limit set of a ‘generic’ infinite iterated function system has box and intermediate dimensions equal to the ambient spatial dimension, where ‘generic’ can refer to any one of (i) full measure; (ii) prevalent; or (iii) comeagre.
Generic properties of Steklov eigenfunctions
Authors: Wang Lihan
Published: July 2022

Let

M
n

M^n

be a smooth compact manifold with smooth boundary. We show that for a generic

C
k

C^k

metric on

M
n

¯

{}\mkern 3mu\overline {\mkern -3muM^n}

with

k
>
n
−
1

k>n-1

, the non-zero Steklov eigenvalues are simple. Moreover, we prove that the non-constant Steklov eigenfunctions have zero as a regular value and are Morse functions on the boundary for such generic metric. These results generalize the celebrated results on Laplacians by Uhlenbeck to the Steklov setting.
When do two rational functions have locally biholomorphic Julia sets?
Authors: Dujardin Romain , Favre Charles , Gauthier Thomas
Published: July 2022

In this article we address the following question, whose interest was recently renewed by problems arising in arithmetic dynamics: under which conditions does there exist a local biholomorphism between the Julia sets of two given one-dimensional rational maps? In particular we find criteria ensuring that such a local isomorphism is induced by an algebraic correspondence. This extends and unifies classical results due to Baker, Beardon, Eremenko, Levin, Przytycki and others. The proof involves entire curves and positive currents.
Guide to Latin in International Law
Authors: Fellmeth Aaron X. , Horwitz Maurice
Published: July 2022

As knowledge of Latin continues to diminish, its frequent use in cases, textbooks, treaties, and scholarly works frequently baffles law students, practitioners, and scholars alike.

The Guide to Latin in International Law seeks to fill the gaps left by the commonly used law dictionaries by taking a comprehensive approach to the subject which includes literal translations of Latin terms and phrases as well as definitions that take into account the common uses of the terms. It also includes examples that show the terms used in context by international law scholars, diplomats, or judges, wherever such examples would be helpful to readers.

Furthermore, the guidebook also features the modern English pronunciation for each term as well as the classical or “restored” pronunciation. In addition, the entries frequently contain etymological information, and each entry is also cross-referenced to related terms for ease of use.

The second edition adds approximately 60 (mostly less common) Latin terms and phrases used in international law writings that were absent from the first edition. It also contains additional examples of usage and etymological information as well as enhanced cross-references.

Because the understanding of Latin is a critical skill for scholars and practitioners who hope to gain a better understanding of sources of law and each other, this book assists international lawyers and law students seeking to master, or at least to decipher, the Latin terminology that permeates scholarly writings in the field, treaties, judgments of international courts and tribunals, and other sources of international law.
Effectiveness of Coronavirus Disease 2019 (COVID-19) Vaccination Against Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection Among Residents of US Nursing Homes Before and During the Delta Variant Predominance, December 2020–November 2021
Authors: Hatfield Kelly M , Baggs James , Wolford Hannah , Fang Michael , Sattar Ammarah A , Montgomery Kelsey S , Jin Steven , Jernigan John , Pilishvili Tamara
Published: July 2022

Background

Residents of nursing homes experience disproportionate morbidity and mortality related to coronavirus disease 2019 (COVID-19) and were prioritized for vaccine introduction. We evaluated COVID-19 vaccine effectiveness (VE) in preventing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections among nursing home residents.

Methods

We used a retrospective cohort of 4315 nursing home residents during 14 December 2020–9 November 2021. A Cox proportional hazards model was used to estimate hazard ratios comparing residents with a completed vaccination series with unvaccinated among those with and without prior SARS-CoV-2 infection, by vaccine product, and by time period.

Results

Overall adjusted VE was 58% (95% confidence interval [CI], 44% to 69%) among residents without a history of SARS-CoV-2 infection. During the pre-Delta period, the VE within 150 days of receipt of the second dose of Pfizer-BioNTech (67%; 95% CI, 40% to 82%) and Moderna (75%; 95% CI, 32% to 91%) was similar. During the Delta period, VE measured >150 days after the second dose was 33% (95% CI, −2% to 56%) for Pfizer-BioNTech and 77% (95% CI, 48% to 91%) for Moderna. Rates of infection were 78% lower (95% CI, 67% to 85%) among residents with prior SARS-CoV-2 infection and completed vaccination series compared with unvaccinated residents without a history of SARS-CoV-2 infection.

Conclusions

COVID-19 vaccines were effective in preventing SARS-CoV-2 infections among nursing home residents, and history of prior SARS-CoV-2 infection provided additional protection. Maintaining high coverage of recommended doses of COVID-19 vaccines remains a critical tool for preventing infections in nursing homes.
Duration of Protection After Vaccination Against Yellow Fever: A Systematic Review and Meta-Analysis
Authors: Kling Kerstin , Domingo Cristina , Bogdan Christian , Duffy Steven , Harder Thomas , Howick Jeremy , Kleijnen Jos , McDermott Kevin , Wichmann Ole , Wilder-Smith Annelies , Wolff Robert
Published: July 2022

The duration of protection after a single dose of yellow fever vaccine is a matter of debate. To summarize the current knowledge, we performed a systematic literature review and meta-analysis. Studies on the duration of protection after 1 and ≥2 vaccine doses were reviewed. Data were stratified by time since vaccination. In our meta-analysis, we used random-effects models. We identified 36 studies from 20 countries, comprising more than 17 000 participants aged 6 months to 85 years. Among healthy adults and children, pooled seroprotection rates after single vaccination dose were close to 100% by 3 months and remained high in adults for 5 to 10 years. In children vaccinated before age 2 years, the seroprotection rate was 52% within 5 years after primary vaccination. For immunodeficient persons, data indicate relevant waning. The extent of waning of seroprotection after yellow fever vaccination depends on age and immune status at primary vaccination.
A Systematic Review of Crohn’s Disease Case Definitions in Administrative or Claims Databases
Authors: Hutfless Susan , Jasper Ryan A , Tilak Aman , Ghosh Tamoghna , Kedia Saurabh , Liu Simon , Urrunaga Nathalie H , Josephson Matthew , Narang Arshit , Miller Steve , Chen Po-Hung , Joseph Shelly , Brant Steven R
Published: July 2022

Background

We sought to review Crohn’s disease (CD) case definitions that use diagnosis, procedure, and medication claims.

Methods

We searched PubMed and Embase from inception through January 31, 2022, using terms related to CD, inflammatory bowel disease, administrative claims, or validity. Each article was scrutinized by 2 authors independently screening and abstracting data. Collected data included participant characteristics, case definition characteristics, and case definition validity. When diagnostic accuracy was provided for multiple case definitions, we extracted the case definition selected by the authors. All diagnostic accuracy characteristics were captured.

Results

We identified 30 studies that evaluated a case definition using claims data to identify CD patients. The most common case definition included counts of diagnosis codes (57%) followed by a combination of diagnosis codes and medications (20%). All but 1 study validated the case definition with a medical chart review. In 2 studies, the patient’s primary care provider completed a survey to confirm disease status. The positive predictive value of the case definitions ranged from 18% (≥1 code at a single U.S. health plan) to 100% (≥1 code plus a relevant prescription at a U.S. hospital). More complex case definitions (eg, ≥1 code + prescription or ≥2 codes) had lower variability in positive predictive value (≥80%) and specificity (≥85%) than the ≥1 code requirement.

Conclusions

Health services researchers should validate case definitions in their research cohorts. When such validation cannot be performed, we recommend using a more complex case definition. Studies without a validated CD case definition should use sensitivity analyses to confirm the robustness of their results.
A spatial analysis of longline survey data for improved indices of Atlantic halibut abundance
Authors: Luo Jiaxin , McDonald Raphaël R , Wringe Brendan F , den Heyer Cornelia E , Smith Bruce , Yan Yuan , Mills Flemming Joanna
Published: July 2022

Atlantic halibut (Hippoglossus hippoglossus) support an economically important fishery on the eastern coast of Canada. Like other species that are not well sampled by trawl surveys, halibut in this area are monitored using longline surveys. These surveys present challenges that can make obtaining indices of abundance difficult. Issues include gear saturation, which can result in a non-linear relationship between catch per unit effort and local abundance. The current approach to obtain a relative index consists of fitting a multinomial exponential model to a subset of hooks from each survey station. While this approach accounts for hook competition, it does not account for the presence of spatial patterns. We therefore extend the multinomial exponential model to include spatial random fields for both Atlantic halibut and non-target species, set-specific soak time, and data from the hooks. Furthermore, we propose a method for aggregating the resulting spatially varying indices to obtain an annual index for the entirety of the modelled area. This novel approach identifies Atlantic halibut hotspots in multiple years, while simultaneously providing relative abundance indices for 2017 through 2020. These outcomes demonstrate the widespread applicability of our methods for improving the scientific advice upon which fisheries management decisions are based.
Risk factors and prognostic significance of postoperative complications following lateral pelvic lymph node dissection for rectal cancer: results of the multicenter lateral node study in China
Authors: Zhou Sicheng , Tang Jianqiang , Mei Shiwen , Lou Zheng , Fu Wei , Feng Bo , Yang Yingchi , Sun Yi , Liu Qian ,   the Chinese Lateral Node Collaborative Group
Published: July 2022

Objective

Total mesorectal excision (TME) plus lateral pelvic lymph node (LPN) dissection (LPND) is a technically complex and challenging procedure with higher morbidity than TME alone. We aimed to investigate the risk factors for postoperative complications after TME + LPND, and the impact of complications on patient prognosis.

Methods

A total of 387 rectal cancer patients with clinical LPN metastasis (LPNM) who underwent TME + LPND at three institutions affiliated with the Chinese Lateral Node Collaborative Group were included. Logistic regression models were used to identify the risk factors for post-surgical complications, and the log-rank test was used to compare the prognosis. Severe complications were described as grade III-V.

Results

The incidence rates of overall complications and severe complications after TME + LPND were 15.2% (59/387) and 7.8% (30/387), respectively. Multivariate analysis showed that a duration of operation ≥260 min was an independent risk factor for both overall (odds ratio [OR] = 3.03, 95% confidence interval [CI] = 1.57–5.85, P = 0.001) and severe postoperative complications (OR = 2.67, 95% CI = 1.06–6.73, P = 0.037). The development of overall postoperative complications (P = 0.114) and severe postoperative complications (P = 0.298) had no significant impact on the overall survival. However, patients with overall complications (P = 0.015) or severe complications (P = 0.031) with a postoperative hospital stay >30 days had significantly an overall worse survival.

Conclusion

A surgical duration of ≥260 min is a significant risk factor for both overall and severe postoperative complications after TME + LPND for middle-low rectal cancer. Furthermore, the development of overall complications or severe complications that require a postoperative hospital stay >30 days significantly worsens the prognosis.
Continuing maintenance temozolomide therapy beyond 12 cycles confers no clinical benefit over discontinuation at 12 cycles in patients with IDH1/2-wildtype glioblastoma
Authors: Ohno Makoto , Miyakita Yasuji , Takahashi Masamichi , Yanagisawa Shunsuke , Tamura Yukie , Narita Yoshitaka
Published: July 2022

Objective

The optimal duration of maintenance temozolomide therapy is controversial. We aimed to examine the clinical benefits of continuing temozolomide therapy beyond 12 cycles in patients with glioblastoma.

Methods

We included 41 patients with isocitrate dehydrogenase 1/2-wildtype glioblastoma, who received 12 or more cycles of temozolomide therapy between June 2006 and December 2019. We evaluated the outcome between 16 patients who continued temozolomide therapy beyond 12 cycles up to 24 cycles (≥13 cycles group) and 25 patients wherein temozolomide therapy was discontinued at 12 cycles (12 cycles group).

Results

The median progression-free survival and survival time after completing 12 cycles (residual progression-free survival and residual overall survival) did not differ between the 12 cycles group and ≥13 cycles group (residual progression-free survival: 11.3 vs. 9.2 months, P = 0.61, residual overall survival: 25.7 vs. 30.2 months, P = 0.76). Multivariate analysis including temozolomide therapy beyond 12 cycles, age at 12 cycles, Karnofsky performance status at 12 cycles, residual tumor at 12 cycles, maintenance therapy regimen and O-6-methylguanine deoxyribonucleic acid methyltransferase promoter methylation status revealed that extended temozolomide therapy beyond 12 cycles was not correlated with residual progression-free survival and residual overall survival (P = 0.80 and P = 0.41, respectively) but Karnofsky performance status at 12 cycles ≥80 was significantly associated with increased residual overall survival (P = 0.0012).

Conclusions

Continuing temozolomide beyond 12 cycles confers no clinical benefit over the discontinuation of temozolomide at 12 cycles. Karnofsky performance status at 12 cycles ≥80 may serve as a novel predictive factor for long-term survival.