bluuebunny/crossref_metadata_2025 huggingface dataset:
Atomistic calculations of thermal conductivity in films made from graphene sheets for electron emitter applications
Authors: Sami S. N. , Islam R. , Joshi R. P.
Published: October 2021

Simulations for the thermal conductivity of carbon fibers (CFs) are carried out based on a molecular dynamics (MD) approach. Our calculations are geared toward providing a general trend for thermal conductivity and its dependence on sample length and to probe the suitability of this material for high power applications from the thermal management standpoint. Since abundant data are not available for carbon fibers, calculations are first carried out in silicon to validate the predictions. The MD results yield a bulk thermal conductivity of 148 W m−1 K−1 for silicon in good agreement with published reports. However, for CF, a much lower bulk value of ∼14 W m−1 K−1 is predicted. This suggests that thermal management would likely be an issue for this material and that CF emitters of lengths below 2 µm should be avoided. The predicted increases in thermal conductivity with temperature may help alleviate the issue to a minor degree. Carbon nanotubes would likely be a better alternative in this context of field emitter arrays.
Effects of surface charge and environmental factors on the electrostatic interaction of fiber with virus-like particle: A case of coronavirus
Authors: Dung D. N. , Phan Anh D. , Nguyen Toan T. , Lam Vu D.
Published: October 2021

We propose a theoretical model to elucidate intermolecular electrostatic interactions between a virus and a substrate. Our model treats the virus as a homogeneous particle having surface charge and the polymer fiber of the respirator as a charged plane. Electric potentials surrounding the virus and fiber are influenced by the surface charge distribution of the virus. We use Poisson–Boltzmann equations to calculate electric potentials. Then, Derjaguin’s approximation and a linear superposition of the potential function are extended to determine the electrostatic force. In this work, we apply this model for coronavirus or SARS-CoV-2 case and numerical results quantitatively agree with prior simulation. We find that the influence of fiber’s potential on the surface charge of the virus is important and is considered in interaction calculations to obtain better accuracy. The electrostatic interaction significantly decays with increasing separation distance, and this curve becomes steeper when adding more salt. Although the interaction force increases with heating, one can observe the repulsive–attractive transition when the environment is acidic.
Development of a rapid plasma decontamination system for decontamination and reuse of filtering facepiece respirators
Authors: Kim Minkwan , Lawson John , Hervé Rodolphe , Jakob Henrike , Ganapathisubramani Bharathram , Keevil Charles W.
Published: October 2021

The COVID-19 pandemic has caused a high demand for filtering facepiece respirators (FFRs), which has brought global challenges in sustaining the supply chain for FFRs. Because respirators are basic personal protective equipment to protect frontline healthcare workers against COVID-19, the chronic, global shortage of N95/N99 masks is one of the most urgent threats to our collective ability to save lives from the coronavirus. The reuse of masks may need to be considered as a crisis capacity strategy to ensure continued availability even though most of the masks are considered one-time use. Moreover, environmentalists warn that single-use masks add to the glut of plastic pollution, threatening the health of oceans and marine life. In this study, we develop a method to decontaminate respirators to reuse filtering facepiece respirators. Samples of SARS-CoV-2 are applied to the 4 × 4 cm2 samples of FFP2 and FFP3 respirator materials. The filtration efficiency of plasma treated samples is measured using a planar particle image velocimetry technique with a neutrally charged polydisperse aerosol particle of NaCl. The measured viral decontamination and filtration efficiencies show that the developed plasma decontamination system can achieve a 4-log reduction for the coronavirus without reducing the filtration efficiency of masks after 5-min plasma exposure. The developed plasma decontamination system demonstrates the feasibility to tackle the acute shortages of FFRs in many countries and their environmental and economic burdens against discarding reusable masks.
Metabolic programming of Rhododendron chrysanthum leaves following exposure to UVB irradiation
Authors: Zhou Xiaofu , Lyu Jie , Sun Li , Dong Jiawei , Xu Hongwei
Published: October 2021

Excessive UVB reaching the earth is a cause for concern. To decipher the mechanism concerning UVB resistance of plants, we studied the effects of UVB radiation on photosynthesis and metabolic profiling of Rhododendron chrysanthum Pall. by applying 2.3 W m−2 of UVB radiation for 2 days. Results showed that maximum quantum yield of PSII (Fv/Fm) and effective quantum yield of PSII (φPSII) decreased by 7.95% and 8.36%, respectively, following UVB exposure. Twenty five known metabolites were identified as most important by two different methods, including univariate and multivariate statistical analyses. Treatment of R. chrysanthum with UVB increased the abundance of flavonoids, organic acids, and amino acids by 62%, 22%, and 5%, respectively. UVB irradiation also induced about 1.18-fold increase in 11 top-ranked metabolites identified: five organic acids (d-2,3-dihydroxypropanoic acid, maleic acid, glyceric acid, fumaric acid and suberic acid), four amino acids (l-norleucine, 3-oxoalanine, l-serine and glycine), and two fatty acids (pelargonic acid and myristoleic acid). In addition, UVB irradiation increased the intermediate products of arginine biosynthesis and the TCA cycle. Taken together, the accumulation of flavonoids, organic acids, amino acids and fatty acids, accompanied by enhancement of TCA cycle and arginine biosynthesis, may protect R. chrysanthum plants against UVB deleterious effects.
Cellular autofluorescence and browning in trichomes of Chinese cabbage (Brassica campestris) in response to mechanical stimulation and senescence
Authors: Sun Xin , Zhao Fanggui , Liu Xin
Published: October 2021

There is limited information concerning the formation of dot-like browning appearing at the base of trichomes on mature leaves on the Chinese cabbage (Brassica campestris L. ssp. pekinensis). This study confirmed for the first time that enhanced autofluorescence can be induced in the base of trichomes when pressure stimuli is applied to trichomes; the enhanced autofluorescence gradually moves to the top of trichomes and the neighbouring mesophyll tissue within 15 min. The excitation of autofluorescence in trichomes was found to be more effective in mature leaves compared to newly emergent leaves. Increased polyphenol oxidase (PPO) activities and reactive oxygen species (ROS) accumulation were also detected in the basal region of trichomes that were subjected to mechanical stimuli. Enhanced fluorescence was observed at the top of the trichomes in senescencing leaves. A browning in the base of the trichomes during leaf senescence was observed. In contrast, no browning occurred at the base of the trichomes in leaves that were subject to pressure stimuli. The blue fluorescence in the trichomes in senescent leaves arises mainly from the condensed cytoplasm. No direct evidence was able to prove that the enhanced autofluorescent substances in the trichomes during leaf senescence are the cause of the browning at the early growth stages.
The role of
Authors: Li Zhe-Xin , Chen Min , Miao Yu-Xiang , Li Qiang , Ren Yun , Zhang Wen-Lin , Lan Jian-Bin , Liu Yi-Qing
Published: October 2021

Kiwifruit (Actinidia chinensis) is rich in nutritional and medicinal value. However, the organism responsible for grey mould, Botrytis cinerea, causes great economic losses and food safety problems to the kiwifruit industry. Understanding the molecular mechanism underlying postharvest kiwifruit responses to B. cinerea is important for preventing grey mould decay and enhancing resistance breeding. Kiwifruit cv. ‘Hongyang’ was used as experimental material. The AcPGIP gene was cloned and virus-induced gene silencing (VIGS) was used to explore the function of the polygalacturonase inhibiting protein (PGIP) gene in kiwifruit resistance to B. cinerea. Virus-induced silencing of AcPGIP resulted in enhanced susceptibility of kiwifruit to B. cinerea. Antioxidant enzymes, secondary metabolites and endogenous hormones were analysed to investigate kiwifruit responses to B. cinerea infection. Kiwifruit effectively activated antioxidant enzymes and secondary metabolite production in response to B. cinerea, which significantly increased Indole-3-acetic acid (IAA), gibberellin 3 (GA3) and abscisic acid (ABA) content relative to those in uninfected fruit. Silencing of AcPGIP enabled kiwifruit to quickly activate hormone-signaling pathways through an alternative mechanism to trigger defence responses against B. cinerea infection. These results expand our understanding of the regulatory mechanism for disease resistance in kiwifruit; further, they provide gene-resource reserves for molecular breeding of kiwifruit for disease resistance.
The antioxidant defense and glyoxalase systems contribute to the thermotolerance of
Authors: Sezgin Muslu Asiye , Kadıoğlu Asim
Published: October 2021

This study focused on the impact of the antioxidant defence and glyoxalase systems on extreme heat tolerance of the thermophilic plant Heliotropium thermophilum L. For this purpose, plants were exposed to 20, 40, 60 and 80 ± 5°C soil temperature gradually for 15 days under laboratory conditions. Our results showed that the hydrogen peroxide and superoxide levels of H. thermophilum were lower at 40 ± 5°C and higher at 80 ± 5°C compared with plants grown at 20 ± 5°C. Some antioxidant enzyme activities tended to increase in plants at 40, 60 and 80 ± 5°C compared with those at 20 ± 5°C and the protein contents responsible for the antioxidant enzymes were in parallel with these enzyme activities. The contents of both reduced and oxidised ascorbate and glutathione rose with increasing temperature. Methylglyoxal level was lower at 40 ± 5°C and higher at 80 ± 5°C compared with plants grown at 20 ± 5°C. Glyoxalase activities highly increased with rising of soil temperature from 20 ± 5°C to 80 ± 5°C. The results of this study suggest that differential modulations of enzymatic antioxidants and the increase in non-enzymatic antioxidants and glyoxalase activities can contribute to the development of the thermotolerance of H. thermophilum through the detoxification of reactive oxygen species and methylglyoxal.
The metabolic reserves, carbohydrate balance and nutritional status of jojoba (
Authors: Lazare Silit , Perry Aviad , Tel-Zur Noemi , Sperling Or , Yermiyahu Uri , Yasuor Hagai , Dag Arnon
Published: October 2021

Jojoba (Simmondsia chinensis (Link) Schneider) holds high industrial value and an extended cultivation trend. Despite its increased importance, there is a lack of fundamental information about its metabolic reserves and development. Our objective was to characterise metabolite allocation and fluctuations in the carbohydrate and nutrient balance of jojoba plants, as affected by fruit load and the plant’s annual cycle. Metabolite profiles were performed for each organ. Soluble carbohydrates (SC) and starch concentrations were surveyed in underground and aboveground organs of high-yield and fruit-removed plants. Simultaneously, nitrogen, potassium and phosphorus were determined in the leaves to evaluate the plant’s nutritional status. We found that sucrose and pinitol were the most abundant sugars in all jojoba organs. Each sugar had a ‘preferred’ organ: glucose was accumulated mainly in the leaves, sucrose and pinitol in woody branches, and fructose in the trunk wood. We found that fruit load significantly influenced the carbohydrate levels in green branches, trunk wood and thin roots. The phenological stage strongly affected the SC–starch balance. Among the examined minerals, only the leaf potassium level was significantly influenced by fruit load. We conclude that jojoba’s nutrient and carbohydrate balance is affected by fruit load and the phenological stage, and describe the organ-specific metabolic reserves.
Identifying the genetic control of salinity tolerance in the bread wheat landrace Mocho de Espiga Branca
Authors: Borjigin Chana , Schilling Rhiannon K. , Jewell Nathaniel , Brien Chris , Sanchez-Ferrero Juan Carlos , Eckermann Paul J. , Watson-Haigh Nathan S. , Berger Bettina , Pearson Allison S. , Roy Stuart J.
Published: October 2021

Salinity tolerance in bread wheat is frequently reported to be associated with low leaf sodium (Na+) concentrations. However, the Portuguese landrace, Mocho de Espiga Branca, accumulates significantly higher leaf Na+ but has comparable salinity tolerance to commercial bread wheat cultivars. To determine the genetic loci associated with the salinity tolerance of this landrace, an F2 mapping population was developed by crossing Mocho de Espiga Branca with the Australian cultivar Gladius. The population was phenotyped for 19 salinity tolerance subtraits using both non-destructive and destructive techniques. Genotyping was performed using genotyping-by-sequencing (GBS). Genomic regions associated with salinity tolerance were detected on chromosomes 1A, 1D, 4B and 5A for the subtraits of relative and absolute growth rate (RGR, AGR respectively), and on chromosome 2A, 2B, 4D and 5D for Na+, potassium (K+) and chloride (Cl−) accumulation. Candidate genes that encode proteins associated with salinity tolerance were identified within the loci including Na+/H+ antiporters, K+ channels, H+-ATPase, calcineurin B-like proteins (CBLs), CBL-interacting protein kinases (CIPKs), calcium dependent protein kinases (CDPKs) and calcium-transporting ATPase. This study provides a new insight into the genetic control of salinity tolerance in a Na+ accumulating bread wheat to assist with the future development of salt tolerant cultivars.
Overexpression of
Authors: Hu Qing , Chen Yanhang , Zhao Yunfeng , Gu Jinbao , Ma Muqing , Li Hua , Li Cong , Wang Zhen-Yu
Published: October 2021

Soil salinity is a significant threat to sustainable agricultural production. Plants must adjust their developmental and physiological processes to deal with environmental salt conditions. We previously identified 18 serine-arginine-rich (SR) proteins from cassava (Manihot esculenta Crantz) that play pivotal roles in alternative splicing when encountering the external stress condition. However, functional characterisation of SR proteins is less reported in cassava, which is an important staple crop in the world. In the current study, we found that the expression of cassava spliceosomal component 35-like 30A (MeSCL30A) was significantly induced in response to drought and salt stress. The MeSCL30A overexpressing lines were also obtained in Arabidopsis thaliana L., which flowered earlier when compared with Col-0. Moreover, the MeSCL30A overexpressing lines were hypersensitive to salt and drought stress with lower germination and greening rate in comparison to Col-0. Importantly, soil-grown overexpression lines exhibited salt sensitivity through modulating the reactive oxygen species homeostasis and negatively regulating the gene expression that involved in ionic stress pathway. Therefore, these findings refined the SR protein-coding genes and provided novel insights for enhancing the resistance to environmental stress in plant.
The Brigalow Catchment Study: VI.
Authors: Tiwari J. , Thornton C. M. , Yu B.
Published: October 2021

Land clearing for cropping and grazing has increased runoff and sediment yield in Central Queensland. The Brigalow Catchment Study (BCS), was established to determine the effect of land clearing on water balance, soils, and productivity, and consisted of three catchments: brigalow forest, cropping, and grazing. Factors responsible for changes in and models for predicting sediment yield have not been assessed. Objectives of this study are to identify climatic, hydrological, and ground cover factors responsible for the increased sediment yield and to assess suitable models for sediment yield prediction. Runoff and sediment yield data from 1988 to 2018 were used to assess the Revised Universal Soil Loss Equation (RUSLE) and the Modified USLE (MUSLE) to predict the sediment yield in brigalow catchments. Common events among the three catchments and events for all catchment pairs were assessed. The sediment yield was approximately 44% higher for cropping and 4% higher for grazing than that from the forested catchment. The runoff amount (Q) and peak runoff rate (Qp) were major variables that could explain most of the increased sediment yield over time. A comparison for each catchment pair showed that sediment yield was 801 kg ha−1 or 37% higher for cropping and 28 kg ha−1 or 2% higher for grazing than for the forested catchment. Regression analysis for three different treatments (seven common events) and for different storm events (15 for forested, 40 for cropping, and 20 for grazing) showed that Q and Qp were best correlated with sediment yield in comparison with variations in ground cover. The high coefficient of determination (R2 > 0.60) provided support for using the MUSLE model, based on both Q and Qp, instead of the RUSLE, and Q and Qp were the most important factors for improving sediment yield predictions from BCS catchments.
Conversion of soil water retention and conductivity parameters from van Genuchten–Mualem to Groenevelt and Grant model
Authors: de Melo Marina Luciana Abreu , de Jong van Lier Quirijn , Armindo Robson André
Published: October 2021

The van Genuchten–Mualem (VGM) model is used largely to represent the relative soil hydraulic conductivity and soil water retention functions [Kr(Θ) and Θ(h)]. Alternative equations proposed by Groenevelt and Grant (GRT) present advantages regarding mathematical versatility. Considering the VGM model cannot be analytically converted into the GRT model, this study empirically related parameters n and α (VGM) to parameters p and k (GRT). We used 90 value combinations of n and α and minimised the sum of squared differences between VGM and GRT models. Linear equations were fitted and validated using soil samples from the UNSODA database. A singular equation of p as a function of n was fitted, while a two-step procedure was required to correlate k and α. All fits resulted in very high precision (r ≥ 0.999) and accuracy (RMSD ≤ 0.025 m3 m−3) for the water retention function and very high precision (r ≥ 0.994) for the hydraulic conductivity function. The accuracy for the Kr(Θ) function was high (RMSD ≤ 0.50) for 34 of the 40 tested soils. The derived empirical equations can be used to convert the equation parameters for Θ(h) regardless of soil type, and for Kr(Θ) with some restrictions upon parameter combinations.
A new perspective on the Basque kopla zaharrak from the Moroccan ayyus
Authors: Gintsburg Sarali
Published: October 2021

In this article I continue reading oral traditional poetry from a cognitive perspective. This time I use findings
obtained empirically from my previous research on the living short improvisational poetic genre ayyu from Morocco
(Gintsburg 2017, 2019a) and turn my
attention to kopla zaharrak, another short oral improvisational poetic genre, which once existed in the Basque
Country but is now extinct and almost forgotten. In order to better understand how this genre once functioned, I first apply to it
the notions of frames, or topics or themes, and scripts, or possible scenarios manifested at
least partly in form of formulaic language, which are triggered by them. The analysis reveals that on the cognitive level
kopla zaharrak offer a structure similar to the ayyu, where the first two lines work as a
frame and the last two lines as a script. In the second part of my research, I compare
examples of kopla zaharrak and ayyus and conclude that, despite obvious cultural and linguistic
differences, the way both traditions make use of images of the natural world and connect them to human situations has demonstrable
similarities.
Optimal indirect estimation for linear inverse problems with discretely sampled functional data
Authors: Pricop-Jeckstadt Mihaela
Published: October 2021

Optimal mean estimation from noisy independent pathes of a stochastic process that are indirectly observed is an issue of great interest in functional inverse problems. In this paper, minimax rates of convergence for a class of linear inverse problems with correlated noise, general source conditions and various degrees of ill-posedness are proven in a continuous setting, when the pathes are entirely observed, and in a projected framework. The phase transition phenomenon characteristic to the functional data analysis appears also here and the thresholds that separate the sparse and the dense data set scenarios are computed for different smoothness conditions. The common design proves to be a special case of the independent design in view of the interpretation of the sampling properties via s-numbers and the price to pay for the data correlation turns out to be high. Finally. numerical experiments involving Abel’s integral operator illustrate the goodness-of-fit of the Tikhonov estimator in various scenarios reflecting the common and independent design as well as sparse and dense sampling.
Suppression of persistent photoconductivity in high gain Ga2O3 Schottky photodetectors*
Authors: Zhou Haitao , Cong Lujia , Ma Jiangang , Li Bingsheng , Xu Haiyang , Liu Yichun
Published: October 2021

The defect-related photoconductivity gain and persistent photoconductivity (PPC) observed in Ga2O3 Schottky photodetectors lead to a contradiction between high responsivity and fast recovery speed. In this work, a metal–semiconductor–metal (MSM) Schottky photodetector, a unidirectional Schottky photodetector, and a photoconductor were constructed on Ga2O3 films. The MSM Schottky devices have high gain (> 13) and high responsivity (> 2.5 A/W) at 230–250 nm, as well as slow recovery speed caused by PPC. Interestingly, applying a positive pulse voltage to the reverse-biased Ga2O3/Au Schottky junction can effectively suppress the PPC in the photodetector, while maintaining high gain. The mechanisms of gain and PPC do not strictly follow the interface trap trapping holes or the self-trapped holes models, which is attributed to the correlation with ionized oxygen vacancies in the Schottky junction. The positive pulse voltage modulates the width of the Schottky junction to help quickly neutralize electrons and ionized oxygen vacancies. The realization of suppression PPC functions and the establishment of physical models will facilitate the realization of high responsivity and fast response Schottky
devices.
A 32-channel 100 GHz wavelength division multiplexer by interleaving two silicon arrayed waveguide gratings*
Authors: Xie Changjian , Zou Xihua , Zou Fang , Yan Lianshan , Pan Wei , Zhang Yong
Published: October 2021

A 32-channel wavelength division multiplexer with 100 GHz spacing is designed and fabricated by interleaving two silicon arrayed waveguide gratings (AWGs). It has a parallel structure consisting of two silicon 16-channel AWGs with 200 GHz spacing and a Mach–Zehnder interferometer (MZI) with 200 GHz free spectral range. The 16 channels of one silicon AWG are interleaved with those of the other AWG in spectrum, but with an identical spacing of 200 GHz. For the composed wavelength division multiplexer, the experiment results reveal 32 wavelength channels in C-band, a wavelength spacing of 100 GHz, and a channel crosstalk lower than –15 dB.
Energy calibration of the GEMPix in the energy range of 6 keV to 2 MeV
Authors: Leidner J. , Murtas F. , Silari M.
Published: October 2021

The GEMPix is a small gaseous detector with a highly
pixelated readout, consisting of a drift region, three Gas Electron
Multipliers (GEMs) for signal amplification, and four Timepix ASICs
with 55 μm pixel pitch and a total of 262,144 pixels (512×512
pixels). A continuous flow of a gas mixture (here propane-based
tissue equivalent gas) is supplied externally at a rate of
5 L/h. By placing a sealed 241Am source outside of the
detector and varying the source-detector distance, the residual
energy of alpha particles entering the sensitive volume of the
GEMPix through a thin Mylar window is varied. An alpha spectrometry
measurement was performed to determine the emission spectrum of the
source, and this spectrum was then used as an input to a FLUKA Monte
Carlo simulation to obtain the residual energy of the alpha
particles. Thus, a calibration curve from 5.9 keV (from an
55Fe source) up to more than 2 MeV was obtained, which is
needed for future applications of the detector, in particular for
microdosimetry.
On an example concerning the second rigidity theorem
Authors: Celikbas Olgur , Matsui Hiroki , Sadeghi Arash
Published: October 2021

In this paper we revisit an example of Celikbas and Takahashi concerning the reflexivity of tensor products of modules. We study Tor-rigidity and the Hochster–Huneke graph with vertices consisting of minimal prime ideals, and determine a condition with which the aforementioned example cannot occur. Our result, in particular, corroborates the Second Rigidity Theorem of Huneke and Wiegand.
Tate resolutions and MCM approximations
Authors: Eisenbud David , Schreyer Frank-Olaf
Published: October 2021

Let

M
M

be a finitely generated Cohen-Macaulay module of codimension

m
m

over a Gorenstein Ring

R
=
S

/

I

R = S/I

, where

S
S

is a regular ring. We show how to form a quasi-isomorphism

ϕ
\phi

from an

R
R

-free resolution of

M
M

to the dual of an

R
R

-free resolution of

M

∨

≔

E
x
t

R

m

(
M
,
R
)

M^{\vee }\colonequals {\mathrm {Ext}}_{R}^{m}(M,R)

using the

S
S

-free resolutions of

R
R

and

M
M

. The mapping cone of

ϕ
\phi

is then a Tate resolution of

M
M

, allowing us to compute the maximal Cohen-Macaulay approximation of

M
M

.

In the case when

R
R

is 0-dimensional local, and

M
M

is the residue field, the formula for

ϕ
\phi

becomes a formula for the socle of

R
R

generalizing a well-known formula for the socle of a zero-dimensional complete intersection.

When

I
⊂
J
⊂
S

I\subset J\subset S

are ideals generated by regular sequences, the

R
R

-module

M
=
S

/

J

M = S/J

is called a quasi-complete intersection, and

ϕ
\phi

was studied in detail by Kustin and Şega. We relate their construction to the sequence of “Eagon-Northcott”-like complexes originally introduced by Buchsbaum and Eisenbud.
The Étale locus in complete local rings
Authors: Heitmann Raymond
Published: October 2021

Let

R
R

be a complete local ring and let

Q
Q

be a prime ideal of

R
R

. It is determined precisely which conditions on

R
R

are equivalent to the existence of a complete unramified regular local ring

A
A

and an element

g
∈
A
−
Q

g\in A-Q

such that

R
R

is a finite

A
A

-module and

A
g

⟶

R
g

A_g\longrightarrow R_g

is étale . A number of other properties of the possible embeddings

A
⟶
R

A\longrightarrow R

are developed in the process including the determination of precisely which fields can be coefficient fields in the Cohen-Gabber Theorem.
A generalization of coefficient ideals
Authors: Lima P.
Published: October 2021

In this paper we give a generalization of the coefficient ideals of an

m

\mathfrak {m}

-primary ideal

I
I

in a quasi-unmixed local ring

R
R

with infinite residue field.
Reducibility of parameter ideals in low powers of the maximal ideal
Authors: Shultis Katharine , Thompson Peder
Published: October 2021

A commutative noetherian local ring

(
R
,

m

)

(R,\mathfrak {m})

is Gorenstein if and only if every parameter ideal of

R
R

is irreducible. Although irreducible parameter ideals may exist in non-Gorenstein rings, Marley, Rogers, and Sakurai show there exists an integer

ℓ
\ell

(depending on

R
R

) such that

R
R

is Gorenstein if and only if there exists an irreducible parameter ideal contained in

m

ℓ

\mathfrak {m}^\ell

. We give upper bounds for

ℓ
\ell

that depend primarily on the existence of certain systems of parameters in low powers of the maximal ideal.
Knutson ideals of generic matrices
Authors: Seccia Lisa
Published: October 2021

In this paper we show that determinantal ideals of generic matrices are Knutson ideals. This fact leads to a useful result about Gröbner bases of certain sums of determinantal ideals. More specifically, given

I
=

I
1

+
…
+

I
k

I=I_1+\ldots +I_k

a sum of ideals of minors on adjacent columns or rows, we prove that the union of the Gröbner bases of the

I
j

I_j

’s is a Gröbner basis of

I
I

.
Comparison of Steklov eigenvalues and Laplacian eigenvalues on graphs
Authors: Shi Yongjie , Yu Chengjie
Published: October 2021

In this paper, we obtain a comparison of Steklov eigenvalues and Laplacian eigenvalues on graphs and discuss its rigidity. As applications of the comparison of eigenvalues, we obtain Lichnerowicz-type estimates and some combinatorial estimates for Steklov eigenvalues on graphs.
Multiplier norm of finite subsets of discrete groups
Authors: Chou Ching
Published: October 2021

Let

G
G

be a discrete group,

V
N
(
G
)

VN(G)

the von Neumann algebra generated by the left translation operators and

A
(
G
)

A(G)

the Fourier algebra of

G
G

. Then

V
N
(
G
)

VN(G)

can be considered as a subspace of

ℓ
2

(
G
)

\ell ^2(G)

and

A
(
G
)
=

ℓ
2

(
G
)
∗

ℓ
2

(
G
)

A(G) = \ell ^2(G)*\ell ^2(G)

. The Banach space dual of

A
(
G
)

A(G)

is

V
N
(
G
)

VN(G)

. The duality between

φ
∈
V
N
(
G
)

\varphi \in VN(G)

and

u
∈
A
(
G
)

u \in A(G)

is

⟨
φ
,
u
⟩
=

∑

x
∈
G

φ
(
x
)
u
(
x
)

\langle \varphi ,u \rangle = \sum _{x \in G}{\varphi (x)u(x)}

, if

φ
∈

ℓ

1

(
G
)

\varphi \in \ell ^{1}(G)

or

u
∈

ℓ
2

(
G
)

u \in \ell ^2(G)

; in these two cases,

φ
u
∈

ℓ

1

(
G
)

\varphi u \in \ell ^{1}(G)

. We will show that if

G
G

is infinite then there exist

φ
∈
V
N
(
G
)

\varphi \in VN(G)

and

u
∈
A
(
G
)

u \in A(G)

such that

φ
u
∉

ℓ

1

(
G
)

\varphi u \notin \ell ^{1}(G)

. When

G
G

is countably infinite, this implies that there exist

φ
∈
V
N
(
G
)

\varphi \in VN(G)

,

u
∈
A
(
G
)

u \in A(G)

and an increasing sequence of finite subsets

F
n

F_n

,

G
=
⋃

F
n

G = \bigcup F_n

such that the sequence

∑

x
∈

F
n

φ
(
x
)
u
(
x
)

\sum _{x \in F_n}{\varphi (x)u(x)}

is divergent and therefore

‖

χ

F

n

‖

M
A
(
G
)

\|{\chi _{F}}_n \|_{MA(G)}

is unbounded. This leads us to give a preliminary study of the growth of

‖

χ

F

‖

M
A
(
G
)

\|\chi _{F}\|_{MA(G)}

as

|

F

|

|F|

, the size of the finite subset

F
F

of

G
G

, is increasing. Recall that when

G
=

Z

G = \mathbb {Z}

, the additive group of integers,
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="double-vertical-bar chi Subscript upper F Baseline double-vertical-bar Subscript upper M upper A left-parenthesis double-struck upper Z right-parenthesis Baseline equals StartFraction 1 Over 2 pi EndFraction integral Subscript 0 Superscript 2 pi Baseline StartAbsoluteValue sigma-summation Underscript k element-of upper F Endscripts e Superscript i k x Baseline EndAbsoluteValue d x">

‖

χ

F

‖

M
A
(

Z

)

=

1

2
π

∫
0

2
π

|

∑

k
∈
F

e

i
k
x

|

d

x

\|\chi _{F}\|_{MA(\mathbb {Z})} = \frac {1}{2\pi }\int _0^{2\pi } \big |\sum _{k \in F} {e^{ikx}}\big | \, d{x}

.
Emergency Department Management of Chest Pain With a High-Sensitivity Troponin-Enabled 0/1-Hour Rule-Out Algorithm
Authors: Bevins Nicholas J , Chae Hyojin , Hubbard Jacqueline A , Castillo Edward M , Tolia Vaishal M , Daniels Lori B , Fitzgerald Robert L
Published: October 2021

Objectives

The analytical sensitivity of high-sensitivity cardiac troponin T (hsTnT) assays has enabled rapid myocardial infarction rule-out algorithms for emergency department (ED) presentations. Few studies have analyzed the real-world impact of hsTnT algorithms on outcomes and operations.

Methods

Comparison of ED length of stay (LOS) and 30-day outcomes (return to ED, inpatient admission, and mortality) for patients presenting with chest pain during 2 separate 208-day periods using a 0/1-hour hsTnT-enabled algorithm or fourth-generation TnT.

Results

Discharge, 30-day readmission, and 30-day mortality rates were not significantly different with fourth-generation TnT vs hsTnT. Thirty-day return rates were significantly decreased with hsTnT (17.4% vs 14.9%; P < .01). For encounters with TnT measured at least twice and resulting in discharge, median ED LOS decreased by 61 minutes with the use of hsTnT (488 vs 427 minutes; P < .0001). Median time between first and second TnT results decreased by 82 minutes with hsTnT (202 vs 120 minutes; P < .0001), suggesting that the 0/1-hour algorithm was incompletely adopted.

Conclusions

Implementation of the hsTnT algorithm was associated with decreased 30-day return rates and decreased ED LOS for a subset of patients, despite incomplete adoption of the 0/1-hour algorithm.
Synthesis and activity of 3-oxo-α-ionone analogs as male attractants for the solanaceous fruit fly,Bactrocera latifrons(Diptera: Tephritidae)
Authors: Yoshida Yukihiro , Haraguchi Dai , Ukuda-Hosokawa Rie , Andou Tsunaki , Matsuyama Takashi , Kohama Tsuguo , Eguchi Takashi , Ohno Satoshi , Ono Hajime , Nishida Ritsuo
Published: October 2021

A series of 3-oxygenated α-ionone analogs have been developed as highly specific male lures for the solanaceous fruit fly Bactrocera latifrons, a pest of solanaceous fruits. We compared the attractant and phagostimulant activities of analogs with or without (i) unsaturations at the 4,5- and/or 7,8-positions and (ii) oxygen moieties at the 3- and/or 9-positions of the ionone molecule. Since naturally occurring vomifoliol (V2) was found to induce a highly potent phagostimulant activity in B. latifrons males, related analogs including dehydrovomifoliol (V1), 6-hydroxy-α-ionone (U1), and 6-hydroxy-α-ionol (U2) were synthesized to evaluate their attractant and phagostimulant activities. Synthetic V1, V2, U1, and U2 exhibited low attractant activity, but their phagostimulant activity was relatively high. Optical isomers of 3-oxo-7,8-dihydro-α-ionone (P3) and V1 were prepared to examine the stereochemical specificity of attractants. (+)-(6R)-P3 and (+)-(6S)-V1 exhibited the corresponding activities, while their respective antipodal enantiomers were found entirely inactive.
SMYD1 alleviates septic myocardial injury by inhibiting endoplasmic reticulum stress
Authors: Chen Meixue , Li Jing , Wang Jinfeng , Le Yuan , Liu Chunfeng
Published: October 2021

Sepsis-induced cardiomyopathy (SIC) is a major complication of sepsis. SET and MYND domain containing 1 (SMYD1) has central importance in heart development, and its role in SIC has not been identified. Herein, we found that the expression of SMYD1 was downregulated in myocardial tissues of SIC patients (from GEO database: GSE79962) and lipopolysaccharide (LPS)-induced SIC rats, and LPS-induced H9c2 cardiomyocytes. We used LPS-stimulated H9c2 cells that mimic sepsis in vitro to explore the function of SMYD1 in SIC. MTT assay, LDH and CK-MB release assay, flow cytometry, and ELISA assay showed that SMYD1 overexpression enhanced cell viability, alleviated cell injury, impeded apoptosis, and reduced the level of proinflammatory factors and NF-κB activation under the condition of LPS stimulation. Moreover, SMYD1 exerted protective effect on H9c2 cells stimulated with LPS through relieving endoplasmic reticulum (ER) stress. In conclusion, overexpression of SMYD1 alleviates cardiac injury through relieving ER stress during sepsis.
Depletion of high-mobility group box 2 causes seminiferous tubule atrophy via aberrant expression of androgen and estrogen receptors in mouse testis
Authors: Sugita Naohiro , Choijookhuu Narantsog , Yano Koichi , Lee Deokcheol , Ikenoue Makoto , Fidya  , Taniguchi Noboru , Chosa Etsuo , Hishikawa Yoshitaka
Published: October 2021

High-mobility group box 2, a chromatin-associated protein that interacts with deoxyribonucleic acid, is implicated in multiple biological processes, including gene transcription, replication, and repair. High-mobility group box 2 is expressed in several tissues, including the testis; however, its functional role is largely unknown. Here, we elucidated the role of high-mobility group box 2 in spermatogenesis. Paraffin-embedded testicular tissues were obtained from 8-week-old and 1-year-old wild-type and knock-out mice. Testis weight and number of seminiferous tubules were decreased, whereas atrophic tubules were increased in high-mobility group box 2-depleted mice. Immunohistochemistry revealed that atrophic tubules contained Sertoli cells, but not germ cells. Moreover, decreased cell proliferation and increased apoptosis were demonstrated in high-mobility group box 2-depleted mouse testis. To elucidate the cause of tubule atrophy, we examined the expression of androgen and estrogen receptors, and the results indicated aberrant expression of androgen receptor and estrogen receptor alpha in Sertoli and Leydig cells. Southwestern histochemistry detected decreased estrogen response element–binding sites in high-mobility group box 2-depleted mouse testis. High-mobility group box 1, which has highly similar structure and function as high-mobility group box 2, was examined by immunohistochemistry and western blotting, which indicated increased expression in testis. These findings indicate a compensatory increase in high-mobility group box 1 expression in high-mobility group box 2 knock-out mouse testis. In summary, depletion of high-mobility group box 2 induced aberrant expression of androgen receptor and estrogen receptor alpha, leading to decreased germ cell proliferation and increased apoptosis which resulted in focal seminiferous tubule atrophy.
Historical biogeography and comparative phylogeography of the Mexican genusBakerantha(Bromeliaceae): insights into evolution and diversification
Authors: Romero-Soler Katya J , Ramírez-Morillo Ivón M , Ruiz-Sanchez Eduardo , Hornung-Leoni Claudia T , Carnevali Germán
Published: October 2021

We studied the rupicolous and dioecious species of Bakerantha (Bromeliaceae) that grow as narrow endemics in central-eastern Mexico. We aimed to describe the spatio-temporal framework in which Bakerantha and its species originated using a phylogeographic and population genetics approach. We carried out population genetics analyses on 29 populations of the five Bakerantha spp., using plastid and nuclear DNA sequences. The data were used to analyse their diversity, genetic structure and demography, to carry out molecular dating and to reconstruction their ancestral area. Our analyses revealed that speciation in Bakerantha began in the Late Pliocene, associated with vicariance resulting from the rise of the Trans-Mexican Volcanic Belt, a barrier that isolated the Bakerantha spp. to its north and south, and subsequent dispersal events in the Sierra Madre Oriental. Genetic data suggest that the species have achieved a high degree of genetic differentiation and variation, but most of them lack intraspecific structure, even though species have remained stable over the time due their life history traits.
Multi-model mapping of phonemic fluency
Authors: Cipolotti Lisa , Xu Tianbo , Harry Bronson , Mole Joe , Lakey Grace , Shallice Tim , Chan Edgar , Nachev Parashkev
Published: October 2021

The voluntary generation of non-overlearned responses is usually assessed with phonemic fluency. Like most frontal tasks, it draws upon different complex processes and systems whose precise nature is still incompletely understood. Many claimed aspects regarding the pattern of phonemic fluency performance and its underlying anatomy remain controversial. Major limitations of past investigations include small sample size, scant analysis of phonemic output and methodologically insufficient lesion analysis approaches. We investigated a large number of patients with focal unilateral right or left frontal (n = 110) or posterior (n = 100) or subcortical (n = 65) lesions imaged with magnetic resonance or computed tomography and compared their performance on the number of overall responses, words produced over time, extremely infrequent/unknown words and inappropriate words generated. We also employed, for the first time parcel-based lesion-symptom mapping, tract-wise statistical analysis as well as Bayesian multi-variate analysis based on meta-analytically defined functional region of interest, including their interactions. We found that left frontal damage was associated with greater impairment than right frontal or posterior damage on overall fluency performance, suggesting that phonemic fluency shows specificity to frontal lesions. We also found that subcorticals, similar to frontals, performed significantly worse than posteriors on overall performance suggesting that subcortical regions are also involved. However, only frontal effects were found for words produced over time, extremely infrequent/unknown and inappropriate words. Parcel-based lesion-symptom mapping analysis found that worse fluency performance was associated with damage to the posterior segment of the left frontal middle and superior gyrus, the left dorsal anterior cingulate gyrus and caudate nucleus. Tract-wise statistical analysis revealed that disconnections of left frontal tracts are critical. Bayesian multi-variate models of lesions and disconnectome maps implicated left middle and inferior frontal and left dorsomedial frontal regions. Our study suggests that a set of well localized left frontal areas together with subcortical regions and several left frontal tracts are critical for word generation. We speculate that a left lateralized network exists. It involves medial, frontal regions supporting the process of ‘energization’, which sustains activation for the duration of the task and middle and inferior frontal regions concerned with ‘selection’, required due to the competition produced by associated stored words, respectively. The methodology adopted represents a promising and empirically robust approach in furthering our understanding of the neurocognitive architecture underpinning executive processes.
Optimal minimax rates against nonsmooth alternatives
Authors: Hitomi Kohtaro , Iwasawa Masamune , Nishiyama Yoshihiko
Published: October 2021

This study investigates optimal minimax rates for specification testing when the alternative hypothesis is built on a set of nonsmooth functions. The set consists of bounded functions that are not necessarily differentiable with no smoothness constraints imposed on their derivatives. In the instrumental variable regression set up with an unknown error variance structure, we find that the optimal minimax rate is $n^{-1/4}$, where n is the sample size. The rate is achieved by a simple test based on the difference between nonparametric and parametric variance estimators. Simulation studies illustrate that the test has reasonable power against various nonsmooth alternatives. The empirical application to Engel curves specification emphasizes the good applicability of the test.
Distributional robustness of K-class estimators and the PULSE
Authors: Jakobsen Martin Emil , Peters Jonas
Published: October 2021

While causal models are robust in that they are prediction optimal under arbitrarily strong interventions, they may not be optimal when the interventions are bounded. We prove that the classical K-class estimator satisfies such optimality by establishing a connection between K-class estimators and anchor regression. This connection further motivates a novel estimator in instrumental variable settings that minimizes the mean squared prediction error subject to the constraint that the estimator lies in an asymptotically valid confidence region of the causal coefficient. We call this estimator PULSE (p-uncorrelated least squares estimator), relate it to work on invariance, show that it can be computed efficiently, as a data-driven K-class estimator, even though the underlying optimization problem is nonconvex, and prove consistency. We evaluate the estimators on real data and perform simulation experiments illustrating that PULSE suffers from less variability. There are several settings, including weak instrument settings, where it outperforms other estimators.
Importance of diagnostic setting in determining mortality in patients with new-onset heart failure: temporal trends in Denmark from 1997 to 2017
Authors: Arulmurugananthavadivel Anojhaan , Holt Anders , Parveen Saaima , Lamberts Morten , Gislason Gunnar H , Torp-Pedersen Christian , Madelaire Christian , Andersson Charlotte , Zahir Deewa , Butt Jawad H , Petrie Mark C , McMurray John , Fosbol Emil L , Kober Lars , Schou Morten
Published: October 2021

Aim

To investigate temporal trends in inpatient vs. outpatient diagnosis of new-onset heart failure (HF) and the subsequent risk of death and hospitalization.

Methods and results

Using nationwide registers, 192 581 patients with a first diagnosis of HF (1997–2017) were included. We computed incidences of HF, age-standardized mortality rates, and absolute risks (ARs) of death and hospitalization (accounting for competing risk of death) to understand the importance of the diagnosis setting in relation to subsequent mortality and hospitalization. The overall incidence of HF was approximately the same (170/100 000 persons) every year during 1997–2017. However, in 1997, 77% of all first diagnoses of HF were made during a hospitalization, whereas the proportion was 39% in 2017. As inpatient diagnoses decreased, outpatient diagnoses increased from 23% to 61%. Outpatients had lower mortality and hospitalization rates than inpatients throughout the study period, although the 1-year age-standardized mortality rate decreased for each inpatient (24 to 14/100-person) and outpatient (11 to 7/100-person). One-year and five-year AR of death decreased by 11.1% and 17.0%, respectively, for all HF patients, while the risk of hospitalization for HF did not decrease significantly (1.13% and 0.96%, respectively).

Conclusion

Between 1997 and 2017, HF changed from being primarily diagnosed during hospitalization to being mostly diagnosed in the outpatient setting. Outpatients had much lower mortality rates than inpatients throughout the study period. Despite a significant decrease in mortality risk for all HF patients, neither inpatients nor outpatients experienced a reduction in the risk of an HF hospitalization.
The survival of blown pack spoilage associatedClostridium estertheticumandClostridium gasigenesspores during the ensiling of grass
Authors: Esteves Eden , Whyte Paul , Gupta Tanushree B , Bolton Declan
Published: October 2021

Blown pack spoilage (BPS) of vacuum packaged primals, caused by Clostridium estertheticum and Clostridium gasigenes, is a serious issue for the beef industry. There are multiple sources of these bacteria on beef farms, including grass and associated feed preparations. The aim of this study was to investigate the survival of C. estertheticum and C. gasigenes spores during the ensiling of grass and the subsequent opening of the silos. Grass, harvested from fields, with and without cattle slurry amendment, was inoculated with approximately 100 spores/g and ensiled using a laboratory (silo) model system at 20°C in the dark. Adding formic acid or sucrose resulted in six treatment combination as follows: no slurry (NS), no slurry plus formic acid (NSFA), no slurry plus sucrose (NSS), slurry (S), slurry plus formic acid (SFA) and slurry plus sucrose (SS). During the silage fermentation, samples were removed periodically and tested for C. estertheticum, C. gasigenes, total viable, Escherichia coli, Enterobacteriaceae and lactic acid bacteria (LAB) counts. The pH, ethanol, volatile fatty acids (VFA), lactic acid and ammonia concentrations were also monitored throughout the experiment. C. estertheticum did not survive the ensiling process, regardless of treatment. In contrast, C. gasigenes grew in the early stages and was detected during the entirety of the fermentation for all treatments. Based on these observations, it was concluded that the silage fermentation process described would not remove C. gasigenes and contaminated grass may result in contaminated feed for animals.