bluuebunny/crossref_metadata_2025_split huggingface dataset:
Unveiling the nature of SgrA* with the geodesic motion of S-stars
Authors: Della Monica Riccardo , de Martino Ivan 
Published: March 2022

Abstract
Despite the huge improvements guaranteed by future GRAVITY observations of the S0-2 star, these will not be able to unveil the fundamental nature, whether black hole or wormhole, of the central supermassive object. Nevertheless, observing stars orbiting closer to the central gravitational source could allow to distinguish between the black hole and wormhole nature of this object at more than 5σ.

Firstly, we have used publicly available astrometric and spectroscopic measurements of the S0-2 star to constrain the metric around the supermassive object without finding any evidence either favouring or ruling out the wormhole nature. Secondly, we have designed a mock catalogue of future observations of the S0-2 star mirroring the accuracy and precision of GRAVITY. Afterwards, we firstly tested our methodology showing that our procedure recovers the input model, and subsequently we demonstrated that the constraining power of such a dataset is not enough to distinguish between black hole and wormhole.
Finally, we built some toy models representing stars orbiting much closer the central object than S0-2.
We used these toy models to investigate which are the ideal orbital features and observational strategies to achieve our aim of unveiling the fundamental nature of the central supermassive object, demonstrating that a star with a period of the order of ∼ 5 years and a pericentre distance of ∼ 5 AU could identify the nature of the central object at almost 5σ accuracy.
Gamma-band enhancement of functional brain connectivity following transcutaneous electrical nerve stimulation
Authors: Zarei Ali Asghar , Jensen Winnie , Faghani Jadidi Armita , Lontis Eugen Romulus , Atashzar S Farokh 
Published: March 2022

Abstract

Objective. Transcutaneous electrical nerve stimulation (TENS) has been suggested as a possible non-invasive pain treatment. However, the underlying mechanism of the analgesic effect of TENS and how brain network functional connectivity (FC) is affected following the use of TENS is not yet fully understood. The purpose of this study was to investigate the effect of high-frequency TENS on the alteration of functional brain network connectivity and the corresponding topographical changes, besides perceived sensations. Approach. Forty healthy subjects participated in this study. Electroencephalography (EEG) data and sensory profiles were recorded before and up to an hour following high-frequency TENS (100 Hz) in sham and intervention groups. Brain source activity from EEG data was estimated using the LORETA algorithm. In order to generate the functional brain connectivity network, the Phase Lag Index was calculated for all pair-wise connections of eight selected brain areas over six different frequency bands (i.e. δ, θ, α, β, γ, and 0.5–90 Hz). Main results. The results suggested that the FC between the primary somatosensory cortex (SI) and the anterior cingulate cortex, in addition to FC between SI and the medial prefrontal cortex, were significantly increased in the gamma-band, following the TENS intervention. Additionally, using graph theory, several significant changes were observed in global and local characteristics of functional brain connectivity in gamma-band. Significance. Our observations in this paper open a neuropsychological window of understanding the underlying mechanism of TENS and the corresponding changes in functional brain connectivity, simultaneously with alteration in sensory perception.
From legacy contamination to watershed systems science: a review of scientific insights and technologies developed through DOE-supported research in water and energy security
Authors: Dwivedi Dipankar , Steefel Carl I , Arora Bhavna , Banfield Jill , Bargar John , Boyanov Maxim I , Brooks Scott C , Chen Xingyuan , Hubbard Susan S , Kaplan Dan , Kemner Kenneth M , Nico Peter S , O’Loughlin Edward J , Pierce Eric M , Painter Scott L , Scheibe Timothy D , Wainwright Haruko M , Williams Kenneth H , Zavarin Mavrik 
Published: March 2022

AbstractWater resources, including groundwater and prominent rivers worldwide, are under duress because of excessive contaminant and nutrient loads. To help mitigate this problem, the United States Department of Energy (DOE) has supported research since the late 1980s to improve our fundamental knowledge of processes that could be used to help clean up challenging subsurface problems. Problems of interest have included subsurface radioactive waste, heavy metals, and metalloids (e.g. uranium, mercury, arsenic). Research efforts have provided insights into detailed groundwater biogeochemical process coupling and the resulting geochemical exports of metals and nutrients to surrounding environments. Recently, an increased focus has been placed on constraining the exchanges and fates of carbon and nitrogen within and across bedrock to canopy compartments of a watershed and in river–floodplain settings, because of their important role in driving biogeochemical interactions with contaminants and the potential of increased fluxes under changing precipitation regimes, including extreme events. While reviewing the extensive research that has been conducted at DOE’s representative sites and testbeds (such as the Oyster Site in Virginia, Savannah River Site in South Carolina, Oak Ridge Reservation in Tennessee, Hanford in Washington, Nevada National Security Site in Nevada, Riverton in Wyoming, and Rifle and East River in Colorado), this review paper explores the nature and distribution of contaminants in the surface and shallow subsurface (i.e. the critical zone) and their interactions with carbon and nitrogen dynamics. We also describe state-of-the-art, scale-aware characterization approaches and models developed to predict contaminant fate and transport. The models take advantage of DOE leadership-class high-performance computers and are beginning to incorporate artificial intelligence approaches to tackle the extreme diversity of hydro-biogeochemical processes and measurements. Recognizing that the insights and capability developments are potentially transferable to many other sites, we also explore the scientific implications of these advances and recommend future research directions.
Resetting random walks in one-dimensional lattices with sinks
Authors: Christophorov L N 
Published: March 2022

Abstract
A standard symmetrical random walk with Poissonian resetting in a chain with terminal sinks is considered. The expressions for probabilities of occupation of chain nodes are obtained for arbitrary values of chain length N, rate k of jumps to adjacent nodes, sink intensities q
0, q

N
and placements of resetting node n

r
and starting node n
0. These expressions are used for calculating the dependences of the prime characteristics of the process (unconditional and conditional mean first passage/exit times and splitting probabilities W
0, W

N
) on resetting rate r. Among a rich variety of process scenarios, the possibility of inverting the ratio W
0/W

N
with r growing is of special interest. This provides an effective mechanism of controlling the process outcome.
Micropatterned conductive elastomer patch based on poly (glycerol sebacate)-graphene for cardiac tissue repair
Authors: Shi Mengting , Bai Lang , Xu Meiguang , Li Zhenlong , Hu Tianli , Hu Juan , Zhang Zixi , Yin Zhanhai , Guo Baolin 
Published: March 2022

Abstract
Preparing a micropatterned elastomer film with characteristics that can simulate the mechanical properties, anisotropy, and electroactivity of natural myocardial tissues is crucial in cardiac tissue engineering after myocardial infarction (MI). Therefore, in this study, we developed several elastomeric films with a surface micropattern based on poly (glycerol sebacate) (PGS) and graphene (Gr). These films have sufficient mechanical strength (0.6 ± 0.1–3.2 ± 0.08 MPa) to withstand heartbeats, and the micropatterned structure also satisfies the natural myocardium anisotropy in the transverse and vertical. Moreover, Gr makes these films conductive (up to 5.80 × 10−7 S m−1), which is necessary for the conduction of electrical signals between cardiomyocytes and the cardiac tissue. Furthermore, they have good cytocompatibility and can promote cell proliferation in H9c2 rat cardiomyocyte cell lines. In vivo test results indicate that these films have good biocompatibility. Notably, a film with 1 wt% Gr content (PGS–Gr1) significantly affects the recovery of myocardial function in rats after MI. This film effectively decreased the infarct size and degree of myocardial fibrosis and reduced collagen deposition. Echocardiographic evaluation showed that after treatment with this film, the left ventricular internal dimension (LVID) in systole and LVID in diastole of rats exhibited a significant downward trend, whereas the fractional shortening and ejection fraction were significantly increased compared with the control group. These data indicate that this electroactive micropatterned anisotropic elastomer film can be applied in cardiac tissue engineering.
Laser induced fluorescence of cervical tissues: an in-vitro study for the diagnosis of cervical cancer from the cervicitis
Authors: Barik Ajaya Kumar , Pavithran M Sanoop , N Mithun , Pai Muralidhar V , Upadhya Rekha , Lukose Jijo , Pai Abhilash K , Pai Kanthilatha , Chidangil Santhosh 
Published: March 2022

Abstract
The transformation of normal cervix to cervicitis as well as to cervical cancer is accompanied with biochemical alterations at cellular level. Laser induced fluorescence (LIF) can reflect those changes either as variations in the fluorescence intensity or as shift in the fluorescence maxima of bio fluorophores present in tissues. The curve resolved fluorescence investigation of tissues under 325 nm excitation provides collagen, bound nicotinamide adenine dinucleotide (NADH) and free NADH as the discrimination factors between normal, cervicitis and cervical cancer. Even though the fluorescence emission intensity derived from collagen fiber is comparable in both normal and cervicitis, a considerable reduction was observed for the cervical cancer tissues compared to the former. Fluorescence corresponding to bound NADH is found to be reduced during the progression from normal to cervicitis and to cervical cancer, whereas the free NADH shows an opposite trend. The principal component analysis (PCA) was performed to obtain classification of spectral data from different categories on a reduced dimensional space. Furthermore, to test the usefulness of the recorded fluorescence spectra in discriminating the malignant and non-malignant (cervicitis and normal) samples, a supervised machine learning model based on support vector machine (SVM) was built using the PCA-reduced data. The proposed SVM model was able to detect the malignant samples with a sensitivity of 94.19% and specificity of 96.51%. Moreover, the Raman spectral data from the corresponding tissue sites corroborate well with the observations derived from the fluorescence measurement. The results obtained in the present pilot study strongly suggests the potential of LIF technique combined with multivariate data analysis tool for the diagnosis of cervicitis and cervical malignancy.
Prediction of dry sliding wear behaviour of China clay particles reinforced AA6082 matrix composites using response surface methodology and analysis of the worn surfaces
Authors: Bright Renjin J , G Selvakumar , M Sumathi 
Published: March 2022

Abstract
This research work presents an attempt solemnly carried out to analyze and predict the wear behaviour of the cost-effective China clay particles reinforced AA6082 aluminium alloy composites. The combined effect of the independent variables (mass fraction of the reinforcement, applied load and sliding speed) on the wear loss and coefficient of friction of the composites were studied. The wear tests were conducted using a computerized pin on disc tribometer. For all the experiments the sliding distance was kept constant as 1500 m. In order to perform the experiments in an organized manner, the response surface methodology (RSM) was designated. The significant parameters which govern the wear loss and coefficient of friction were identified using the ANOVA (Analysis of variance) test. The regression equations developed to predict the response parameters (wear and coefficient of friction) were validated extensively by choosing several values of the independent variables within the design space. From the study, it was noted that RSM holds good reliability in the prediction of the wear behaviour of the composites. The composite materials exhibited better wear resistance with the increase in the incorporation of China clay particles. The worn-out samples were segregated as high, medium and low wear loss categories to analyze the worn surface morphology and to interpret the wear mechanism.
A Monte Carlo study of near infrared light propagation in the human head with lesions—a time-resolved approach
Authors: Vera Demián A , García Héctor A , Victoria Waks Serra Ma , Baez Guido R , Iriarte Daniela I , Pomarico Juan A 
Published: March 2022

Abstract
Several clinical conditions leading to traumatic brain injury can cause hematomas or edemas inside the cerebral tissue. If these are not properly treated in time, they are prone to produce long-term neurological disabilities, or even death. Low-cost, portable and easy-to-handle devices are desired for continuous monitoring of these conditions and Near Infrared Spectroscopy (NIRS) techniques represent an appropriate choice. In this work, we use Time-Resolved (TR) Monte Carlo simulations to present a study of NIR light propagation over a digital MRI phantom. Healthy and injured (hematoma/edema) situations are considered. TR Diffuse Reflectance simulations for different lesion volumes and interoptode distances are performed in the frontal area and the left parietal area. Results show that mean partial pathlengths, photon measurement density functions and time dependent contrasts are sensitive to the presence of lesions, allowing their detection mainly for intermediate optodes separations, which proves that these metrics represent robust means of diagnose and monitoring. Conventional Continuous Wave (CW) contrasts are also presented as a particular case of the time dependent ones, but they result less sensitive to the lesions, and have higher associated uncertainties.
Ta/NiO subwavelength bilayer for wide gamut, strong interference structural color
Authors: Spenato David , Dubreuil Matthieu , Morineau Denis , Giamarchi Philippe , Dekadkevi David , Jay Jean-Philippe , Fessant Alain , Rivet Sylvain , Le Grand Yann 
Published: March 2022

Abstract
In this paper we demonstrate that Ta/NiO bilayers may be use as high-efficiency, lithography free, reflective structural color filters for generating broad color gamut. Experimental results show that reflectance spectra present deep dips in the visible range, leading to strong structural colors that can be adjusted via the NiO subwavelength layer thickness. Simulation based on thin film interference theory allow to account for the experimental data. We demonstrate that the optical interference effect is still effective when the films are deposited on a flexible substrates such as paper and kapton, enabling to consider flexible color filtering applications.
Plant and soil microbial responses to irrigation retirement in semiarid cropping systems
Authors: Núñez Agustín , Ball Ryan , Schipanski Meagan 
Published: March 2022

Abstract
Water scarcity limits irrigated agriculture, and there is an increasing frequency of situations where farmers must transition from irrigated to dryland cropping systems. This transition poses several challenges, and it is necessary to understand the changes in crop productivity and soil health for the design of viable cropping systems. Our objective was to compare the impact of irrigation retirement on crop production and soil microbial dynamics under the two major crops of the semiarid High Plains. In a formerly irrigated field, we installed a transition experiment that consisted of two irrigation managements, irrigated and non-irrigated (retired), under two cropping systems: continuous maize and continuous winter wheat. Lower soil moisture after irrigation retirement decreased plant biomass production in both crops, with a higher effect on maize (2 to 6-fold decrease) than on wheat (20% less aboveground biomass production). In both crops, irrigation retirement affected crop development in the order grain yield > aboveground biomass > belowground biomass. Soil microbial communities were less affected by irrigation retirement than the evaluated crops and changes were concentrated in the maize agroecosystem. After three seasons, the high decrease in maize productivity and soil moisture resulted in 50% less extracellular enzyme activity in the dryland treatment, but without consistent effects on microbial biomass or community composition assessed by phospholipid fatty acids. Winter wheat appears as a viable option not only to sustain crop production but also to minimize the negative impacts of irrigation retirement on soil health. However, root production was lower in wheat than in maize, which may affect the long-term evolution of soil organic carbon.
Finite-field coupling via learning the charge response kernel
Authors: Shao Yunqi , Andersson Linnéa , Knijff Lisanne , Zhang Chao 
Published: March 2022

Abstract
Response of the electronic density at the electrode–electrolyte interface to the external field (potential) is fundamental in electrochemistry. In density-functional theory, this is captured by the so-called charge response kernel (CRK). Projecting the CRK to its atom-condensed form is an essential step for obtaining the response charge of atoms. In this work, the atom-condensed CRK is learnt from the molecular polarizability using machine learning (ML) models and subsequently used for the response-charge prediction under an external field (potential). As the machine-learnt CRK shows a physical scaling of polarizability over the molecular size and does not (necessarily) require the matrix-inversion operation in practice, this opens up a viable and efficient route for introducing finite-field coupling in the atomistic simulation of electrochemical systems powered by ML models.
Heat kernels for reflected diffusions with jumps on inner uniform domains
Authors: Chen Zhen-Qing , Kim Panki , Kumagai Takashi , Wang Jian 
Published: March 2022

In this paper, we study sharp two-sided heat kernel estimates for a large class of symmetric reflected diffusions with jumps on the closure of an inner uniform domain

D
D

in a length metric space. The length metric is the intrinsic metric of a strongly local Dirichlet form. When

D
D

is an inner uniform domain in the Euclidean space, a prototype for a special case of the processes under consideration is symmetric reflected diffusions with jumps on

D
D

, whose infinitesimal generators are non-local (pseudo-differential) operators

L

\mathcal {L}

on

D
D

of the form
\[

L

u
(
x
)

=

1
2

∑

i
,
j
=
1

d

∂

∂

x
i

(

a

i
j

(
x
)

∂
u
(
x
)

∂

x
j

)

+

lim

ε
↓
0

∫

{
y
∈
D
:

ρ
D

(
y
,
x
)
>
ε
}

(
u
(
y
)
−
u
(
x
)
)
J
(
x
,
y
)

d
y

\mathcal {L} u(x)\! =\!\frac 12 \!\sum _{i, j=1}^d\! \frac {\partial }{\partial x_i}\! \left (\!\!a_{ij}(x) \frac {\partial u(x)}{\partial x_j}\!\right ) \!+ \lim _{\varepsilon \downarrow 0}\! \int _{\{y\in D: \, \rho _D(y, x)>\varepsilon \}}\!\! (u(y)-u(x)) J(x, y)\, dy

\]
satisfying “Neumann boundary condition”. Here,

ρ
D

(
x
,
y
)

\rho _D(x,y)

is the length metric on

D
D

,

A
(
x
)
=
(

a

i
j

(
x
)

)

1
≤
i
,
j
≤
d

A(x)=(a_{ij}(x))_{1\leq i,j\leq d}

is a measurable

d
×
d

d\times d

matrix-valued function on

D
D

that is uniformly elliptic and bounded, and
\[

J
(
x
,
y
)
≔

1

Φ
(

ρ
D

(
x
,
y
)
)

∫

[

α
1

,

α
2

]

c
(
α
,
x
,
y
)

ρ
D

(
x
,
y

)

d
+
α

ν
(
d
α
)
,

J(x,y)≔\frac {1}{\Phi (\rho _D(x,y))} \int _{[\alpha _1, \alpha _2]} \frac {c(\alpha , x,y)} {\rho _D(x,y)^{d+\alpha }} \,\nu (d\alpha ),

\]
where

ν
\nu

is a finite measure on

[

α
1

,

α
2

]
⊂
(
0
,
2
)

[\alpha _1, \alpha _2] \subset (0, 2)

,

Φ
\Phi

is an increasing function on

[
0
,
∞
)

[ 0, \infty )

with

c
1

e

c
2

r

β

≤
Φ
(
r
)
≤

c
3

e

c
4

r

β

c_1e^{c_2r^{\beta }} \le \Phi (r) \le c_3 e^{c_4r^{\beta }}

for some

β
∈
[
0
,
∞
]

\beta \in [0,\infty ]

, and

c
(
α
,
x
,
y
)

c(\alpha , x, y)

is a jointly measurable function that is bounded between two positive constants and is symmetric in

(
x
,
y
)

(x, y)

.
The cross–product conjecture for width two posets
Authors: Chan Swee Hong , Pak Igor , Panova Greta 
Published: March 2022

The cross–product conjecture (CPC) of Brightwell, Felsner and Trotter [Order 12 (1995), pp. 327-349] is a two-parameter quadratic inequality for the number of linear extensions of a poset

P
=
(
X
,
≺
)

P= (X, \prec )

with given value differences on three distinct elements in

X
X

. We give two different proofs of this inequality for posets of width two. The first proof is algebraic and generalizes CPC to a four-parameter family. The second proof is combinatorial and extends CPC to a

q
q

-analogue. Further applications include relationships between CPC and other poset inequalities, and the equality part of the CPC for posets of width two.
Poisson boundary on full Fock space
Authors: Rajarama Bhat B. , Bikram Panchugopal , De Sandipan , Rakshit Narayan 
Published: March 2022

This article is devoted to studying the non-commutative Poisson boundary associated with

(

B

(

F

(

H

)

)

,

P

ω

)

\Big (B\big (\mathcal {F}(\mathcal {H})\big ), P_{\omega }\Big )

where

H

\mathcal {H}

is a separable Hilbert space (finite or infinite-dimensional),

dim
⁡

H

>
1

\dim \mathcal {H} > 1

, with an orthonormal basis

E

\mathcal {E}

,

B

(

F

(

H

)

)

B\big (\mathcal {F}(\mathcal {H})\big )

is the algebra of bounded linear operators on the full Fock space

F

(

H

)

\mathcal {F}(\mathcal {H})

defined over

H

\mathcal {H}

,

ω
=
{

ω
e

:
e
∈

E

}

\omega = \{\omega _e: e \in \mathcal {E} \}

is a sequence of strictly positive real numbers such that

∑
e

ω
e

=
1

\sum _e \omega _e = 1

and

P

ω

P_{\omega }

is the Markov operator on

B

(

F

(

H

)

)

B\big (\mathcal {F}(\mathcal {H})\big )

defined by

P

ω

(
x
)
=

∑

e
∈

E

ω
e

l
e
∗

x

l
e

,

x
∈
B

(

F

(

H

)

)

,

\begin{align*} P_{\omega }(x) = \sum _{e \in \mathcal {E}} \omega _e l_e^* x l_e, \ x \in B\big (\mathcal {F}(\mathcal {H})\big ), \end{align*}

where, for

e
∈

E

e \in \mathcal {E}

,

l
e

l_e

denotes the left creation operator associated with

e
e

. We observe that the non-commutative Poisson boundary associated with

(

B

(

F

(

H

)

)

,

P

ω

)

\Big (B\big (\mathcal {F}(\mathcal {H})\big ), P_{\omega }\Big )

is

σ
\sigma

-weak closure of the Cuntz algebra

O

dim
⁡

H

\mathcal {O}_{\dim \mathcal {H}}

generated by the right creation operators. We prove that the Poisson boundary is an injective factor of type

I
I
I

III

for any choice of

ω
\omega

. Moreover, if

H

\mathcal {H}

is finite-dimensional, we completely classify the Poisson boundary in terms of its Connes’

S
S

invariant and curiously they are type

I
I

I

λ

III _{\lambda }

factors with

λ
\lambda

belonging to a certain small class of algebraic numbers.