bluuebunny/crossref_metadata_2025 huggingface dataset:
Intrinsic root morphology determines the phosphorus acquisition efficiency of five annual pasture legumes irrespective of mycorrhizal colonisation
Authors: McLachlan Jonathan W. , Becquer Adeline , Haling Rebecca E. , Simpson Richard J. , Flavel Richard J. , Guppy Chris N.
Published: September 2020

Mycorrhizal fungi are ubiquitous in agroecosystems and form symbiotic associations that contribute to the phosphorus (P) acquisition of many plants. The impact of mycorrhizas is most pronounced in P-deficient soil and commonly involves modifications to the root morphology of colonised plants. However, the consequences of mycorrhizal colonisation on root acclimation responses to P stress are not well described. Five annual pasture legumes, with differing root morphologies, were grown to determine the effect of mycorrhizal colonisation on shoot yield, root morphology and P uptake. Micro-swards of each legume were established in pots filled with a topsoil layer that had been amended with five rates of P fertiliser. The topsoil overlaid a low-P subsoil that mimicked the stratification of P that occurs under pasture. Mycorrhizal colonisation improved P acquisition and shoot yield in the low-P soil treatments, but did not reduce the critical external P requirement of the legumes for near-maximum yield. The yield responses of the mycorrhizal plants were associated with reduced dry matter allocation to topsoil roots, which meant that the P acquisition benefit associated with mycorrhizal colonisation was not additive in the P-deficient soil. The contribution of the mycorrhizal association to P acquisition was consistent among the legumes when they were compared at an equivalent level of plant P stress, and was most pronounced below a P stress index of ~0.5. The intrinsic root morphology of the legumes determined their differences in P-acquisition efficiency irrespective of mycorrhizal colonisation.
Hydrogen sulfide induced by hydrogen peroxide mediates brassinosteroid-induced stomatal closure of Arabidopsis thaliana
Authors: Ma Yinli , Shao Luhan , Zhang Wei , Zheng Fengxi
Published: September 2020

The role of hydrogen sulfide (H2S) and its relationship with hydrogen peroxide (H2O2) in brassinosteroid-induced stomatal closure in Arabidopsis thaliana (L.) Heynh. were investigated. In the present study, 2,4-epibrassinolide (EBR, a bioactive BR) induced stomatal closure in the wild type, the effects were inhibited by H2S scavenger and synthesis inhibitors, and H2O2 scavengers and synthesis inhibitor. However, EBR failed to close the stomata of mutants Atl-cdes, Atd-cdes, AtrbohF and AtrbohD/F. Additionally, EBR induced increase of L-/D-cysteine desulfhydrase (L-/D-CDes) activity, H2S production, and H2O2 production in the wild type, and the effects were inhibited by H2S scavenger and synthesis inhibitors, and H2O2 scavengers and synthesis inhibitor respectively. Furthermore, EBR increased H2O2 levels in the guard cells of AtrbohD mutant, but couldn’t raise H2O2 levels in the guard cells of AtrbohF and AtrbohD/F mutants. Next, scavengers and synthesis inhibitor of H2O2 could significantly inhibit EBR-induced rise of L-/D-CDes activity and H2S production in the wild type, but H2S scavenger and synthesis inhibitors failed to repress EBR-induced H2O2 production. EBR could increase H2O2 levels in the guard cells of Atl-cdes and Atd-cdes mutants, but EBR failed to induce increase of L-/D-CDes activity and H2S production in AtrbohF and AtrbohD/F mutants. Therefore, we conclude that H2S and H2O2 are involved in the signal transduction pathway of EBR-induced stomatal closure. Altogether, our data suggested that EBR induces AtrbohF-dependent H2O2 production and subsequent AtL-CDes-/AtD-CDes-catalysed H2S production, and finally closes stomata in A. thaliana.
Spatial heterogeneity can lead to substantial local variations in COVID-19 timing and severity
Authors: Thomas Loring J. , Huang Peng , Yin Fan , Luo Xiaoshuang Iris , Almquist Zack W. , Hipp John R. , Butts Carter T.
Published: September 2020

Significance

We examine the effects of an uneven population distribution on the spread of the COVID-19 disease spread, using a diffusion model based on interpersonal contact networks. Taking into account spatial heterogeneity, the spread of COVID-19 is much “burstier” than in standard epidemiological models, with substantial local disparities in timing and severity and long lags between local outbreaks. We show that spatial heterogeneity may produce dramatic differences in social exposures to those with the illness, and may stress health care delivery systems in ways that are not well captured by standard SIR-like models.
Zn2+ to probe voltage-gated proton (Hv1) channels
Authors: Larsson H. Peter
Published: September 2020

Cherny and coworkers use zinc ion as a probe to identify different conformational states of voltage-gated proton (Hv1) channels.
Mott Transition and Superconductivity in Quantum Spin Liquid Candidate NaYbSe2
Authors: Jia Ya-Ting , Gong Chun-Sheng , Liu Yi-Xuan , Zhao Jian-Fa , Dong Cheng , Dai Guang-Yang , Li Xiao-Dong , Lei He-Chang , Yu Run-Ze , Zhang Guang-Ming , Jin Chang-Qing
Published: September 2020

The Mott transition is one of the fundamental issues in condensed matter physics, especially in the system with antiferromagnetic long-range order. However, such a transition is rare in quantum spin liquid (QSL) systems without long-range order. Here we report the experimental pressure-induced insulator to metal transition followed by the emergence of superconductivity in the QSL candidate NaYbSe2 with a triangular lattice of 4f Yb3+ ions. Detail analysis of transport properties in metallic state shows an evolution from non-Fermi liquid to Fermi liquid behavior when approaching the vicinity of superconductivity. An irreversible structure phase transition occurs around 11 GPa, which is revealed by the x-ray diffraction. These results shed light on the Mott transition in the QSL systems.
Dynamical systems in perturbative scalar field cosmology
Authors: Alho Artur , Uggla Claes , Wainwright John
Published: September 2020

We derive a new regular dynamical system on a three-dimensional compact state space describing linear scalar perturbations of spatially flat Robertson–Walker geometries for relativistic models with a minimally coupled scalar field with an exponential potential. This enables us to construct the global solution space, illustrated with figures, where known solutions are shown to reside on special invariant sets. We also use our dynamical systems approach to obtain new results about the comoving and uniform density curvature perturbations. Finally we show how to extend our approach to more general scalar field potentials. This leads to state spaces where the state space of the models with an exponential potential appears as invariant boundary sets, thereby illustrating their role as building blocks in a hierarchy of increasingly complex cosmological models.
Obtaining the Bragg curve using a low-cost detector
Authors: Klosowski Allison , Bastos Rodrigo Oliveira
Published: September 2020

The Bragg curve has special significance for modern medicine. The pronounced peak of energy loss at the end of the heavy charged particle path in matter allows tumors to be treated more accurately with protons and other heavier ions beams. In order to use simple devices to experimentally illustrate the principles involved in the charged particle energy loss in matter, we present how to build a low-cost detector to study the loss of energy of alpha particles in air and obtain the Bragg curve.
Scaling effects and brittle fracture mechanisms in laser punching of PECVD SiO2 films
Authors: Sakaev I , Berg Y , Kotler Z , Ishaaya A A
Published: September 2020

We experimentally investigate the removal of several microns thick plasma-enhanced chemical vapour deposition SiO2 films by a localized dynamic fracture due to confined laser–matter interaction with the silicon substrate (punching) using 10 ps laser pulses at 355 nm. A near order of magnitude increase in the punching threshold fluence (from ∼0.1 to ∼1 J cm−2) is observed as the ratio between the spot size and the film thickness is scaled down, in order to produce high aspect ratio openings in the film. An opening radius of about twice the film thickness appears to be an approximate practical limit. A high aspect ratio opening is created by a cone fracture of the film and the ejection of a conoid film segment (flyer). We discuss mechanisms of brittle fracture that may lead to the observed patterns.
Continuous trapping of bacteria in non-Newtonian blood flow using negative dielectrophoresis with quadrupole electrodes
Authors: Ren Qinlong , Liang Chenxing , Wang Zexiao , Qu Z G
Published: September 2020

Efficient trapping of bacteria from whole blood is essential for point-of-care diagnostics of sepsis at an early stage in order to reduce morbidity and mortality. However, low bacteria concentration and the presence of blood cells hinder the trapping efficiency of bacteria from whole blood. As red blood cells comprise 94.9% of total blood cells, lysing the red blood cells using saponin could effectively attenuate the influence of the blood component on the bacteria-trapping process. In this situation, long-range bacteria trapping from whole blood using a hybrid electrokinetic based lab-on-a-chip device becomes promising. In this paper, through developing a multi-physical lattice Boltzmann method with Langevin dynamics, the continuous trapping process of S. aureus in a microfluidic channel with quadrupole electrodes under combined alternating-current electrothermal electrohydrodynamic force and negative dielectrophoresis force is numerically investigated and optimized at various parametric conditions. Based on the statistical data, a stable bacteria recovery rate of 68.4%–74.5% is successfully achieved with respect to different bacteria densities under appropriate operational conditions of the designed lab-on-a-chip device. The current work demonstrates the potential of continuous bacteria trapping from whole blood using hybrid electrokinetic phenomena.
A new two-dimensional semiconducting carbon allotrope with direct band gap: a first-principles prediction
Authors: Yang Xing , Wang Yuwei , Xiao Ruining , Liu Huanxiang , Bing Zhitong , Zhang Yang , Yao Xiaojun
Published: September 2020

Two-dimensional (2D) carbon materials with an appropriate band gap play important roles in the various electronics fields. Here, based on first-principles calculations, we predict a new 2D carbon allotrope containing 32 atoms, consists of pentagonal, hexagonal, octagonal and decagonal rings. This new allotrope is named as Po-C32, which possesses P4/MMM symmetry with a tetragonal lattice and has a vertical distance of 2.22 Å between the uppermost and undermost atoms. The cohesive energy, phonon band structure, ab initio molecular dynamics simulations and elastic constants fitting confirm Po-C32 has high stabilities. The fitted in-plane Young’s modulus and Poisson’s ratio along
a
and
b
directions are Y

a
= Y

b
= 244 N m−1 and v

a
= v

b
= 0.14, respectively, exhibiting the same mechanical properties along
a
and
b
directions. Interestingly, Po-C32 is a semiconductor with a direct band gap of 2.05 eV, comparable to that of phosphorene, exhibiting great potential in nanoelectronics. Moreover, two stable derivative allotropes are also predicted based on Po-C32. Po-C24-3D is an indirect narrow band gap (1.02 eV) semiconductor, while Po-C32-3D possesses a wider indirect band gap of 3.90 eV, which can be also applied in optoelectronic device.
Nanoscale structural and electrical properties of graphene grown on AlGaN by catalyst-free chemical vapor deposition
Authors: Giannazzo F , Dagher R , Schilirò E , Panasci S E , Greco G , Nicotra G , Roccaforte F , Agnello S , Brault J , Cordier Y , Michon A
Published: September 2020

The integration of graphene (Gr) with nitride semiconductors is highly interesting for applications in high-power/high-frequency electronics and optoelectronics. In this work, we demonstrated the direct growth of Gr on Al0.5Ga0.5N/sapphire templates by propane (C3H8) chemical vapor deposition at a temperature of 1350 °C. After optimization of the C3H8 flow rate, a uniform and conformal Gr coverage was achieved, which proved beneficial to prevent degradation of AlGaN morphology. X-ray photoemission spectroscopy revealed Ga loss and partial oxidation of Al in the near-surface AlGaN region. Such chemical modification of a ∼2 nm thick AlGaN surface region was confirmed by cross-sectional scanning transmission electron microscopy combined with electron energy loss spectroscopy, which also showed the presence of a bilayer of Gr with partial sp2/sp3 hybridization. Raman spectra indicated that the deposited Gr is nanocrystalline (with domain size ∼7 nm) and compressively strained. A Gr sheet resistance of ∼15.8 kΩ sq−1 was evaluated by four-point-probe measurements, consistently with the nanocrystalline nature of these films. Furthermore, nanoscale resolution current mapping by conductive atomic force microscopy indicated local variations of the Gr carrier density at a mesoscopic scale, which can be ascribed to changes in the charge transfer from the substrate due to local oxidation of AlGaN or to the presence of Gr wrinkles.
Vanadium disulfide for ultrafast photonic application
Authors: Pang Lihui , Li Lu , Wang Rongfeng , Zhao Qiyi , Liu Wenjun , Wu Rongqian , Lv Yi
Published: September 2020

The investigation of two-dimensional (2D) nonlinear optical materials offers a promising way to construct the high-performance optical devices in fundamental and industrial applications because of their rich distinct optoelectronic properties. Herein, by utilizing the liquid exfoliation method, vanadium disulfide (VS2) nanosheets are prepared and the thickness is measured to be 3.16 nm. In addition, we have fabricated the VS2-based optical device and the nonlinear optical property is characterized with modulation depth of 23.97%. By using VS2 as saturable absorber, a high stable passively mode-locking Er-doped fiber laser is obtained with pulse duration of 169 fs and the largest average output power of 70.5 mW. The slope efficiency is up to 7.9%. In comparison to recent results of mode-locking fiber lasers with 2D materials, the VS2-based fiber laser demonstrates better performance. To the best of our knowledge, this is the first example of using VS2 for generating femtosecond mode-locked laser pulse. Our experimental results not only reveal VS2 ultrafast photonics application, but also advance the high-performance applications for information science and nonlinear optics.
Overnight airway obstruction severity prediction centered on acoustic properties of smart phone: validation with esophageal pressure
Authors: Markandeya Mrunal N , Abeyratne Udantha R , Hukins Craig
Published: September 2020

Objective: Obstructive sleep apnea is characterized by a number of airway obstructions. Esophageal pressure manometry (EPM) based estimation of consecutive peak to trough differences (ΔPes) is the gold standard method to quantify the severity of airway obstructions. However, the procedure is rarely available in sleep laboratories due to invasive nature. There is a clinical need for a simplified, scalable technology that can quantify the severity of airway obstructions. In this paper, we address this and propose a pioneering technology, centered on sleep related respiratory sound (SRS) to predict overnight ΔPes signal.Approach: We recorded streams of SRS using a bedside iPhone 7 smartphone from subjects undergoing diagnostic polysomnography (PSG) studies and EPM was performed concurrently. Overnight data was divided into epochs of 10 s duration with 50% overlap. Altogether, we extracted 42 181 such epochs from 13 subjects. Acoustic features and features from the two PSG signals serve as an input to train a machine learning algorithm to achieve mapping between non-invasive features and ΔPes values. A testing dataset of 14 171 epochs from four new subjects was used for validation.Main results: The SRS based model predicted the ΔPes with a median of absolute error of 6.75 cmH2O (±0.59,r= 0.83(±0.03)). When information from the PSG were combined with the SRS, the model performance became: 6.37cmH2O (±1.02,r= 0.85(±0.04)).Significance: The smart phone based SRS alone, or in combination with routinely collected PSG signals can provide a non-invasive method to predict overnight ΔPes. The method has the potential to be automated and scaled to provide a low-cost alternative to EPM.
New low temperature multidipole plasma device with a magnetic X-point and its properties
Authors: Lim Yegeon , You Yong Sung , Lee Wonjun , Ahn Bin , Moon Se Youn , Kim Bosung , Woo H J , Lho Taihyeop , Choe Wonho , Ghim Y-c
Published: September 2020

A new low temperature multidipole plasma device with a magnetic X-point is developed. With a usual multidipole configuration generated by permanent neodymium magnets, a pair of axially flowing electrical currents up to 1.0 kA in the chamber creates figure-eight shaped poloidal magnetic fields with the X-point which separates plasmas into three distinct regions of core, edge and private regions. This new device, magnetic X-point simulator system (MAXIMUS), is equipped with end-plate wall filaments, core filaments and a LaB6 cathode as DC plasma sources. A wide range of plasma densities from 108 to 1012 cm−3 with electron temperatures of 0.4 to 3 eV is achieved. Plasmas in MAXIMUS are highly correlated with the shape of the magnetic fields as electrons are magnetized. Furthermore, electron velocity distribution functions can be significantly modified from usual Maxwellian distributions due to the strong grad-B and curvature drifts of electrons, resulting in high skewness and excess kurtosis. Such a capability of controlling the distribution function as well as having closed circular magnetic fields will allow us to systematically investigate effects of non-Maxwellian distribution functions and curved magnetic fields on various physical phenomena such as cross-field diffusion process, plasma waves and many nonlinear physics including solitons, shock waves and three-wave interactions. Tokamak edge physics correlated with neutral particles is also to be investigated with MAXIMUS.
A quantum heat machine from fast optomechanics
Authors: Bennett James S , Madsen Lars S , Rubinsztein-Dunlop Halina , Bowen Warwick P
Published: September 2020

We consider a thermodynamic machine in which the working fluid is a quantized harmonic oscillator that is controlled on timescales that are much faster than the oscillator period. We find that operation in this ‘fast’ regime allows access to a range of quantum thermodynamical behaviors that are otherwise inaccessible, including heat engine and refrigeration modes of operation, quantum squeezing, and transient cooling to temperatures below that of the cold bath. The machine involves rapid periodic squeezing operations and could potentially be constructed using pulsed optomechanical interactions. The prediction of rich behavior in the fast regime opens up new possibilities for quantum optomechanical machines and quantum thermodynamics.
Influence of CX-reactions on the radiation in the pedestal region at ASDEX Upgrade
Authors: Dux R. , Cavedon M. , Kallenbach A. , McDermott R.M. , Vogel G. , ASDEX Upgrade team the
Published: September 2020

The radial density profiles of Ne10 +  and Ne8 +  have been measured with charge exchange recombination spectroscopy in an H-mode discharge in ASDEX Upgrade. When trying to fit the data with an impurity transport code that only takes electronic ionisation and recombination into account, the density of Ne8 +  is too low by more than an order of magnitude indicating that an additional recombination mechanism must be at work. We ascribe the missing recombination channel to charge exchange (CX) reactions between neutral deuterium and the impurity ions, which has long been known to be a very efficient recombination reaction. Including the CX-reactions yields a good fit of the ionisation balance and delivers the neutral density profile in the pedestal, which is not known from other diagnostics. Here, the CX-reactions lead to a change of the ionisation balance on the whole flux surface and the measurement delivers a flux surface averaged neutral density with the exception of the region very close to the X-point. Furthermore, it leads to an increase of the pedestal radiation of neon since the partially ionised stages can emit line radiation. This amounts to an increase of the radiated power of neon inside of the separatrix by a factor of 5. A similar analysis was done for argon in an H-mode discharge dominated by Ar radiation. Only the CX-recombination in the pedestal can explain the radiated power inside the separatrix, which would be too low by a factor of 2.2 without CX. In addition, the radiances of VUV lines from many charge stages are much better fitted when including the CX-recombination. A simple projection of the impact of CX-recombination to the much hotter ITER pedestals shows that for elements up to Kr, a beneficial increase of edge radiated power per core radiated power and of radiated power per central dilution is obtained, while for Xe and especially for W the effect is weak.
Fishery observers address arctic fishery discards
Authors: Snyder Hunter T , Erbaugh James T
Published: September 2020

Fishery observers are prevalent actors in the global effort to reduce discards in fisheries, but there remains considerable uncertainty about how effective they are. We analyzed high-resolution logbook records of individual hauls (n = 127 415) across five-and-a-half-years (2012–2018) for all of Greenland’s large-scale fisheries to determine if onboard fishery observers influence the mandatory reporting of discards. To do so, we used exact matching to compare reported discards for observed and unobserved hauls (each time a catch is recorded), thus controlling for systematic differences between monitored and unmonitored practices. After adjusting for variables that represent species caught, gear, vessel, owner, year, license, and location, we found that skippers systematically underreport discards when no observers are on board. Systematic underreporting was most pronounced in less valuable fisheries, in contrast to theoretical arguments in previous studies. The differences between reported discards from observed and unobserved fishing leads us to assume that onboard observers encourage more faithful logbook records. Thus, onboard observers play a vital role in improving information on the environmental impact of fishing and in turn, make a key contribution to sustainable fisheries management.
The 0-concordance monoid admits an infinite linearly independent set
Authors: Dai Irving , Miller Maggie
Published: September 2020

Under the relation of

0
0

-concordance, the set of knotted 2-spheres in

S
4

S^4

forms a commutative monoid

M

0

\mathcal {M}_0

with the operation of connected sum. Sunukjian [Int. Math. Res. Not. IMRN 17 (2015), pp. 7950–7978] has recently shown that

M

0

\mathcal {M}_0

contains a submonoid isomorphic to

Z

≥
0

\mathbb {Z}^{\ge 0}

. In this note, we show that

M

0

\mathcal {M}_0

contains a submonoid isomorphic to

(

Z

≥
0

)
∞

(\mathbb {Z}^{\ge 0})^\infty

. Our argument relates the

0
0

-concordance monoid to linear independence of certain Seifert solids in the spin rational homology cobordism group.
Periodic solutions and attractiveness for some partial functional differential equations with lack of compactness
Authors: Ezzinbi Khalil , Taoudi Mohamed Aziz
Published: September 2020

This paper deals with the existence of periodic solutions and attractiveness for some partial functional differential equations in Banach spaces. We assume that the first linear part generates a strongly continuous semigroup, while the delayed part is periodic with respect to the first argument. We prove that the existence of a bounded solution implies the existence of a periodic solution. Several results regarding uniqueness and global attractiveness of periodic solutions are also established. The analysis relies on a fixed point theorem of Chow and Hale’s type and uses some arguments of weak topology. Our theorems extend in a broad sense some new and classical related results. An application to a transport equation with delay is also presented.
A group invariant Bishop-Phelps theorem
Authors: Falcó Javier
Published: September 2020

We show that for any Banach space and any compact topological group

G
⊂
L
(
X
)

G\subset L(X)

such that the norm of

X
X

is

G
G

-invariant, the set of norm attaining

G
G

-invariant functionals on

X
X

is dense in the set of all

G
G

-invariant functionals on

X
X

, where a mapping

f
f

is called

G
G

-invariant if for every

x
∈
X

x\in X

and every

g
∈
G

g\in G

,

f

(

g
(
x
)

)

=
f
(
x
)

f\big (g(x)\big )=f(x)

. In contrast, we show also that the analog of Bollobás result does not hold in general. A version of Bollobás and James’ theorems is also presented.
Countably and entropy expansive homeomorphisms with the shadowing property
Authors: Artigue Alfonso , Carvalho Bernardo , Cordeiro Welington , Vieitez José
Published: September 2020

We discuss the dynamics beyond topological hyperbolicity considering homeomorphisms satisfying the shadowing property and generalizations of expansivity. It is proved that transitive countably expansive homeomorphisms satisfying the shadowing property are expansive in the set of transitive points. This is in contrast with pseudo-Anosov diffeomorphisms of the two-dimensional sphere that are transitive, cw-expansive, satisfy the shadowing property but the dynamical ball in each transitive point contains a Cantor subset. We exhibit examples of countably expansive homeomorphisms that are not finite expansive, satisfy the shadowing property and admits an infinite number of chain-recurrent classes. We further explore the relation between countable and entropy expansivity and prove that for surface homeomorphisms

f
:
S
→
S

f\colon S\to S

satisfying the shadowing property and

Ω
(
f
)
=
S

\Omega (f)=S

, both countably expansive and entropy cw-expansive are equivalent to being topologically conjugate to an Anosov diffeomorphism.
Psychosocial Interventions for Reducing Suicidal Behaviour and Alcohol Consumption in Patients With Alcohol Problems: A Systematic Review of Randomized Controlled Trials
Authors: Hurzeler Tristan , Giannopoulos Vicki , Uribe Gabriela , Louie Eva , Haber Paul , Morley Kirsten C
Published: September 2020

Objective

We aimed to provide a synthesis and evaluation of psychosocial interventions to prevent suicide and reduce self-harm, as well as alcohol intake, for patients with alcohol problems.

Methods

The systematic review was carried out according to the PRISMA guidelines and considered articles published in English from all countries. Terms relating to suicidality and alcohol problems were used to search Medline, EMBASE and PsycINFO databases. Randomized controlled trials of psychosocial interventions targeted for outpatient settings were included.

Results

Six studies with a total of 400 participants were included. Two investigated dialectic behavioural therapy (DBT), one internet-delivered DBT, one dynamic deconstructivist psychotherapy (DDP) and two integrated cognitive behavioural therapy (CBT). Face to face and online DBT was significantly associated with abstinence and reductions in consumption with only a trend for a reduction in suicide attempts in one study relative to treatment at usual (TAU). DDP yielded significant reductions in alcohol consumption and suicide attempts versus community care. CBT was significantly effective relative to TAU in reducing alcohol use and suicide attempts in one trial with adolescents but not in another trial in an adult population.

Conclusion

Integrated CBT has promise for adolescents, DBT may be helpful for alcohol patients with borderline personality disorder and iDBT may be useful for the wider community with heavy alcohol use. However, given the paucity of studies and the exploratory nature of these trials, there is currently no strong evidence for an effective psychosocial intervention to reduce alcohol consumption and suicidal behaviour in adults with problematic alcohol use.
Literary Genealogies and the Kinship of Black Modernity
Authors: Fielder Brigitte
Published: September 2020

This brief essay is a reflection on the genealogical as a metaphor for modernity’s teleologies. Considering genealogy not as a biological lineage but as a network of kinship relations, we can better understand the collective—and often teleologically recursive—means by which modernity is imagined and reimagined. Understood via this metaphor of relation, we can see how modernity is not simply a progressive line of descendancy, but a complex web of influence. Our methodologies for tracing modernity’s genealogies must therefore think beyond what is inevitable and toward the deliberate and multiplicitous practices contributing to its reproduction. These methodologies must often follow circuitous routes that defy normative disciplinary taxonomies and frameworks. Moreover, the process of tracing modernity’s genealogies is ongoing, perpetuated always to the present moment as its study is also a mechanism for its perpetual reproduction.

Black genealogical reproduction is an involved process in modernity, encompassing mechanisms from the bodily to the aesthetic to the technological, resisting normalized teleologies of descent, and extending its branches into complex webs that emerge within Black futures and help to produce them.
Knock-Down of Hippocampal DISC1 in Immune-Challenged Mice Impairs the Prefrontal–Hippocampal Coupling and the Cognitive Performance Throughout Development
Authors: Xu Xiaxia , Song Lingzhen , Hanganu-Opatz Ileana L
Published: September 2020

Disrupted-in-schizophrenia 1 (DISC1) gene represents an intracellular hub of developmental processes. When combined with early environmental stressors, such as maternal immune activation, but not in the absence of thereof, whole-brain DISC1 knock-down leads to memory and executive deficits as result of impaired prefrontal–hippocampal communication throughout development. While synaptic dysfunction in neonatal prefrontal cortex (PFC) has been recently identified as one source of abnormal long-range coupling, the contribution of hippocampus (HP) is still unknown. Here, we aim to fill this knowledge gap by combining in vivo electrophysiology and optogenetics with morphological and behavioral assessment of immune-challenged mice with DISC1 knock-down either in the whole brain (GE) or restricted to pyramidal neurons in hippocampal CA1 area (GHPE). We found abnormal network activity, sharp-waves, and neuronal firing in CA1 that complement the deficits in upper layer of PFC. Moreover, optogenetic activating CA1 pyramidal neurons fails to activate the prefrontal local circuits. These deficits that persist till prejuvenile age relate to dendrite sparsification and loss of spines of CA1 pyramidal neurons. As a long-term consequence, DISC1 knock-down in HP leads to poorer recognition memory at prejuvenile age. Thus, DISC1-controlled developmental processes in HP in immune-challenged mice are critical for circuit function and cognitive behavior.
Competition Among Three Forensically Important Blow Fly Species (Diptera: Calliphoridae):Phormia regina, Lucilia sericata, andChrysomya rufifacies
Authors: MacInnis Amber E , Higley Leon G
Published: September 2020

Avoiding competition is thought to explain insect successional patterns on carrion, but few studies have looked at competition directly. We use replacement series experiments with three species of blow flies: Phormia regina (Meigen) (Diptera: Calliphoridae), Lucilia sericata (Meigen) (Diptera:Calliphoridae), and Chrysomya rufifacies (Macquart) (Diptera:Calliphoridae) to characterize competitive relationships. From experimental results, P. regina showed a significant competitive advantage over L. sericata. Infestation of carrion differs between L. sericata and P. regina; specifically, L. sericata oviposits on carrion without any delay, while P. regina typically delays oviposition. Our findings are consistent with the notion that differences in oviposition times represent a mechanism for L. sericata to avoid potential competition. Competition by C. rufifacies differs since C. rufifacies, in the event of a limited food supply, will prey on other maggot species. In replacement series experiments, C. rufifacies killed all P. regina in mixed treatments, representing an ultimate competitive advantage. In the United States, these two species do not often overlap because of differences in seasonal distribution. However, with climate change, phenological separation may grow less distinct. Surprisingly, in replacement series experiments with C. rufifacies and L. sericata, no competitive interactions were observed. In other studies, L. sericata has been shown to form clusters away from predaceous maggots, allowing improved survival, which may account for the absence of predation by C. rufifacies. Finally, this study shows that replacement series models are useful in measuring competition, supporting the notion that interspecific competition between necrophagous insect species may have driven life history traits of those species.
Leaflet kinematics after the Yacoub and Florida-sleeve operations: results of an in vitro study
Authors: Tasca Giordano , Jaworek Michal , Lucherini Federico , Trinca Francesco , Redaelli Paola , Antona Carlo , Vismara Riccardo
Published: September 2020

OBJECTIVES

The Florida-sleeve is a valve-sparing technique that causes minimal interference to leaflet kinematics and aortic root dynamism. The aim of this in vitro study was to evaluate the effects of the Florida-sleeve and Yacoub techniques on aortic leaflet kinematics.

METHODS

Two groups of 6 whole porcine hearts were treated with either the Florida-sleeve technique or the Yacoub technique and tested in a pulsatile loop. Valve fluid dynamics, coronary flow analysis and valve echocardiograms were performed both before and after the procedures.

RESULTS

Both procedures showed no difference in rapid valve opening time as compared with their respective baseline values. The Florida-sleeve procedure showed a shorter slow closing time (192 ± 19 ms vs baseline 244 ± 14 ms, P = 0.016) and increased slow closing velocity (−1.5 ± 0.4 cm/s vs baseline −0.8 ± 0.4 cm/s, P = 0.038). In the rapid valve closing phase, the Yacoub procedure showed a trend towards slower closing valve velocity (−16 ± 9 cm/s vs baseline −25 ± 9 cm/s, P = 0.07). The Yacoub procedure showed larger leaflet displacement at the end of the slow valve closing time that was 2.0 ± 0.5 cm vs baseline 1.5 ± 0.3 cm, P = 0.044. When comparing the Florida-sleeve and Yacoub procedures, the former showed statistically significant shorter slow valve closing time (P = 0.017).

CONCLUSIONS

This study showed that the Florida-sleeve technique alters the slow closing phase of the aortic valve leaflet kinematics when compared with both the normal baseline and Yacoub procedure, while the latter showed a larger leaflet displacement before the rapid closing valve phase.
Magnetotelluric investigation of the Precambrian crust and intraplate Cenozoic volcanism in the Gour Oumelalen area, Central Hoggar, South Algeria
Authors: Boukhalfa Zakaria , Bouzid Abderrezak , Xu Yixian , Bendaoud Abderrahmane , Yang Bo , Hamoudi Mohamed , Bougchiche Said Sofiane , Deramchi Aboubakr , Amara Massinissa , Ouzegane Khadidja , Boukhlouf Walid , Abtout Abdeslam , Bendekken Abdelhamid , Djeddi Mohamed
Published: September 2020

The Tuareg Shield was assembled by oceanic closures and horizontal movements along mega-shear zones between approximately 20 terranes during the Pan-African Orogeny (750–550 Ma). Although there is an ongoing debate about its origin, the exhumation of the Tuareg Shield is assumed to be related to Cenozoic intraplate volcanism. The Gour Oumelalen is a key region of the Tuareg Shield and is located in the northeastern part of the Egéré-Aleksod terrane, corresponding to the eastern boundary of the Archean–Palaeoproterozoic microcontinent LATEA (Central Hoggar). The eastern boundary of the study area corresponds to a Neoproterozoic suture zone separating two old microcontinents, LATEA and the Orosirian Stripe. We deployed two magnetotelluric (MT) profiles consisting of 33 broad-band MT stations and combined these with aeromagnetic data, aiming to define the crustal structure in detail. The resistivity cross-sections obtained from the 3-D inversion of full impedance tensor and tipper data from stations along the profiles, confirm the main Precambrian faults, some of which are covered by Quaternary sediments and hence, have not yet been deciphered. The cross-sections also highlight the Cretaceous–Quaternary sedimentary basins represented by low resistivities. The upper crust is typically cratonic with a high electrical resistivity. On the contrary, the lower crust shows a drastic drop in resistivity (<10 Ωm). The most plausible hypothesis is that the study area corresponds to a Cretaceous rifting zone. The Cretaceous magmatic event and its related fluids and mineralization as well as the recent fluids associated with Cenozoic volcanism, are plausible causes of a very conductive lower crust. However, we cannot exclude other reasons such as: (i) a high-temperature and strongly sheared mobile belt or (ii) a contribution of inheritance involving Pan-African events that affected this former suture area.
Spatio-temporal analysis of seismic anisotropy associated with the Cook Strait and Kaikōura earthquake sequences in New Zealand
Authors: Graham Kenny M , Savage Martha K , Arnold Richard , Zal Hubert J , Okada Tomomi , Iio Yoshihisa , Matsumoto Satoshi
Published: September 2020

Large earthquakes can diminish and redistribute stress, which can change the stress field in the Earth’s crust. Seismic anisotropy, measured through shear wave splitting (SWS), is often considered to be an indicator of stress in the crust because the closure of cracks due to differential stress leads to waves polarized parallel to the cracks travelling faster than in the orthogonal direction. We examine spatial and temporal variations in SWS measurements and the Vp/Vs ratio associated with the 2013 Cook Strait (Seddon, Grassmere) and 2016 Kaikōura earthquakes in New Zealand. These earthquake sequences provide a unique data set, where clusters of closely spaced earthquakes occurred. We use an automatic, objective splitting analysis algorithm and automatic local S-phase pickers to expedite the processing and to minimize observer bias. We present SWS and Vp/Vs measurements for over 40 000 crustal earthquakes across 36 stations spanning close to $5\frac{1}{2}$ yr between 2013 and 2018. We obtain a total of 102 260 (out of 398 169) high-quality measurements. We observe significant spatial variations in the fast polarization orientation, ϕ. The orientation of gravitational stresses are consistent with most of the observed anisotropy. However, multiple mechanisms (such as structural, tectonic stresses and gravitational stresses) may control some of the observed crustal anisotropy in the study area. Systematic analysis of SWS parameters and Vp/Vs ratios revealed that apparent temporal variations are caused by variation in earthquake path through spatially varying media.
Factors associated with high pain catastrophizing in patients undergoing hip arthroscopy for femoroacetabular impingement syndrome
Authors: Dumont Guillaume D , Land Joel , Battle Nicole C , Glenn Rachel L , Menge Travis J , Thier Zachary T
Published: September 2020

The purpose of this study was to determine if physical, mental health and patient-specific factors are associated with increased Pain Catastrophizing in patients undergoing hip arthroscopy for femoroacetabular impingement syndrome (FAIS). Patients who underwent primary hip arthroscopy for FAIS were retrospectively analyzed. Patients were included if they completed a standard pre-operative questionnaire which included the Pain Catastrophizing Scale (PCS), VAS and 12-Item Short Form Survey (SF-12) Physical and Mental Composite Scores. Patient-specific variables including age, gender, BMI, tobacco use, number of allergies, pre-operative opioid use and diagnosis of depression or anxiety were recorded. Multiple linear regression was performed to assess for a relationship between physical and mental health scores, patient-specific variables, and a ‘High Catastrophizing’ PCS score. One-hundred and sixty-eight patients were included in this study. Patients with a PCS score of 22 or above were categorized as ‘High Catastrophizing’. The variables included in the multiple linear regression model statistically significantly predicted high pain catastrophizing, F(10,149) = 4.75, P < 0.001, R2 = 0.4. SF-12 Physical and Mental Composite Scores and a mental health illness diagnosis added statistically significantly to the prediction, P < 0.005. Pre-operative hip arthroscopy patients with better general physical and mental health, as measured by the SF-12, and those without mental health illness are less likely to having higher pain catastrophizing scores. Age, gender, BMI, visual analog pain scale (VAS), tobacco use, number of allergies and pre-operative opioid use were not independently associated with elevated pain catastrophizing scores. These findings may be helpful when interpreting PCS scores and counseling patients prior to arthroscopic hip surgery.
Epigenetic Age Acceleration and Chronic Health Conditions Among Adult Survivors of Childhood Cancer
Authors: Qin Na , Li Zhenghong , Song Nan , Wilson Carmen L , Easton John , Mulder Heather , Plyler Emily , Neale Geoffrey , Walker Emily , Zhou Xin , Pan Haitao , Hudson Melissa M , Yasui Yutaka , Robison Leslie L , Zhang Jinghui , Ness Kirsten K , Wang Zhaoming
Published: September 2020

Background

Mounting evidence supports the occurrence of accelerating aging among long-term survivors of childhood cancer. We aimed to investigate epigenetic age acceleration (EAA) in survivors and evaluate associations between EAA, treatment exposures, health behaviors, and chronic health conditions (CHCs).

Methods

Genome-wide methylation data were generated with Infinium EPIC BeadChip on blood-derived DNA from 2139 survivors and 282 frequency matched controls from the St Jude Lifetime Cohort Study. EAAs were estimated as residuals from a linear regression of epigenetic age (Levine’s clock) against chronological age. Adjusted least square mean (ALSM) of EAA was calculated and compared between survivors and controls, across treatment exposures and health behaviors. Associations of EAA with 20 clinically assessed CHCs were evaluated with multivariable piecewise-exponential models. All statistical tests for P values below were 2-sided.

Results

EAA was statistically significantly higher in survivors than controls (ALSM = 0.63, 95% confidence interval [CI] = 0.26 to 1.01 vs −3.61, 95% CI = −4.43 to 2.80). In a multivariable model among survivors, statistically significantly higher EAA (P < .05) was observed in those exposed to chest radiotherapy, abdomen or pelvic radiotherapy, alkylating agents, glucocorticoids, or epipodophyllotoxins. Compared with survivors with favorable health behaviors (ALSM = 0.26, 95% CI=−0.36 to 0.87), EAA was statistically significantly higher among survivors with intermediate (ALSM = 1.07, 95% CI = 0.59 to 1.54) or unfavorable health behaviors (ALSM = 1.45, 95% CI = 0.60 to 2.30). In time-to-event analyses, statistically significant associations were identified between EAA tertiles and incidence of 7 CHCs: hypertension (3rd vs 1st tertile, relative rate [RR] = 1.83, 95% CI = 1.17 to 2.83), myocardial infarction (RR = 2.91, 95% CI = 1.27 to 7.21), obesity (RR = 1.39, 95% CI = 1.17 to 1.66), obstructive pulmonary deficit (RR = 1.86, 95% CI = 0.95 to 3.77), peripheral motor neuropathy (RR = 2.89, 95% CI = 1.24 to 6.97), peripheral sensory neuropathy (RR = 2.04, 95% CI = 0.99 to 4.26), and pulmonary diffusion deficits (RR = 2.75, 95% CI = 0.95 to 7.63).

Conclusions

EAA is statistically significantly higher in survivors of childhood cancer than in noncancer controls and is associated with specific treatment exposures, unfavorable health behaviors, and presence of specific CHCs.
A Novel Approach to Understanding Social Behaviors in Pediatric Brain Tumor Survivors: A Pilot Study
Authors: Desjardins Leandra , Lai Meng-Chuan , Vorstman Jacob , Bartels Ute , Barrera Maru
Published: September 2020

Background/Objectives

Pediatric brain tumor survivors (PBTS) are at risk of experiencing challenges in social adjustment. However, the specific social behaviors of PBTS have rarely been directly assessed. This pilot study explores the first novel use of the Autism Diagnostic Observation Schedule, second edition (ADOS-2), to evaluate the social behaviors of PBTS.

Methods

Twenty-six PBTS (ages 9–17 years; M = 7.8 years from diagnosis; 52% male; 41% received radiation treatment) completed the ADOS-2. The proportion of the sample experiencing impairment was examined descriptively across all items of the ADOS-2, as well as by a summary “overall score” created for this study, and using the ADOS-2 “diagnostic algorithm” scores for autism. Social adjustment, cognitive, medical, and demographic variables were explored as correlates of the ADOS-2 “overall score”.

Results

Study recruitment was 34%, impeded by distance from the tertiary-care center. The percentage of PBTS experiencing detectable impairments ranged from 0% to 50% across ADOS-2 items. Cranial radiation treatment, lower IQ, and slower cognitive processing were associated with higher impairment on the ADOS-2 “overall score”.

Conclusion

The ADOS-2 can be used to assess the discrete social behaviors of PBTS. This study provides a foundation for future investigations using the ADOS-2 to assess social behaviors in this population. Identifying specific social behavior difficulties in PBTS is key to refining much needed targeted social skills interventions for this population.
Blunt vascular trauma in a patient with peripheral arterial disease: a case report and review of the literature
Authors: Karachentsev Sergiy
Published: September 2020

Blunt vascular trauma is rare and challenging in management. Trauma victims who are elderly and have medical comorbidities are still uncommon, but their proportion is expected to increase, as life expectancy has been rising worldwide. A case of blunt vascular trauma to the lower extremity in a 70-year-old patient is reported. During the procedure, a contusion of the superficial femoral artery with thrombosis was identified. Besides, the artery was found to be affected by atherosclerosis. Thrombectomy with resection of the artery and end-to-end anastomosis was performed. Good early clinical outcome was achieved. Nonsystematic review of the available literature is also presented.
Pinpointing secondary metabolites that shape the composition and function of the plant microbiome
Authors: Jacoby Richard P , Koprivova Anna , Kopriva Stanislav
Published: September 2020

One of the major questions in contemporary plant science involves determining the functional mechanisms that plants use to shape their microbiome. Plants produce a plethora of chemically diverse secondary metabolites, many of which exert bioactive effects on microorganisms. Several recent publications have unequivocally shown that plant secondary metabolites affect microbiome composition and function. These studies have pinpointed that the microbiome can be influenced by a diverse set of molecules, including: coumarins, glucosinolates, benzoxazinoids, camalexin, and triterpenes. In this review, we summarize the role of secondary metabolites in shaping the plant microbiome, highlighting recent literature. A body of knowledge is now emerging that links specific plant metabolites with distinct microbial responses, mediated via defined biochemical mechanisms. There is significant potential to boost agricultural sustainability via the targeted enhancement of beneficial microbial traits, and here we argue that the newly discovered links between root chemistry and microbiome composition could provide a new set of tools for rationally manipulating the plant microbiome.