bluuebunny/crossref_metadata_2025 huggingface dataset:
Segregation of Ca at the Mg/MgO interface and its effect on grain refinement of Mg alloys
Authors: Wang S H , Wang F , Wang Y , Ramasse Q M , Fan Z
Published: May 2019

It has been reported that native MgO particles in Mg alloy melts can act as heterogeneous nucleation substrates such that grain refinement of Mg alloys is achieved. A recent study showed the addition of Ca, combined with the native MgO particles, significantly improves grain refinement of Mg and its alloys. However, the mechanism underlying the grain refining phenomenon is not well understood due to the lack of direct experimental evidence. In this work, we investigated the segregation of Ca atoms at the Mg/MgO interface and its effect on grain refinement in Mg-0.5Ca alloys by utilizing advanced analytical electron microscopy. The experimental results focus on the chemical and structural information at the interface between MgO and the Ca solute. Adsorption layers rich in Al, N and Ca have been detected on {1 1 1} facets of MgO particles, with the lattice structure resembling the structure of MgO. It is suggested that the significant grain refinement improvement can be attributed not only to the growth restriction due to the presence of Ca addition but also to the specific chemistry and structure of the adsorption layers.
On Analytical Concepts of Novel Multi-Resolution Casting Simulations
Authors: Horr Amir M
Published: May 2019

One of the crucial ingredients of today’s numerical simulation technologies is their cross-scale and cross-platform capabilities for material processes applications. Handling of simultaneous evolution paths at various scales\times (i.e., multi-scaling) during complex material processes where materials microstructure & microchemistry interact with meso and macro events, is one of awkward challenges of computational material engineering. The material phase change and also its thermal energy evolutions are also drastically increasing the complexity of the numerical simulations. The introduction of multi-resolution and multi-scale numerical schemes in recent years and their ground-breaking potentials for computational material science applications have vividly raised the expectations for more resourceful future virtual tools. A crucial point in implementing these novel numerical techniques for simulation of material processes is their flexibility towards the modelling approach (i.e., discrete, continuous…) and also their compatibility with solver-independent platforms. As these multi-resolution\physical techniques should provide some answers to the best ways of designing future high-performance materials along with optimisation of new & existing material processes and also improvement of their life-time performance, a broad & well-structured research work is required. Hence, the proposed multi-resolution framework herein, has been developed based on analytical & numerical techniques built on sound physical and mathematical foundations developed during the last few decades. The combination of recently developed concepts of dynamic\evolving domains along with cross-scale grid overlapping\interfacing and also sound parallel computing routines have been employed to address the multi-scale challenges of material processes simulations. In the research work herein, analytical and computational aspects of multi-resolution simulation framework for dynamic casting processes (i.e., continuous and semi-continuous casting) are presented and physical\mathematical basis of the analytical-computational solidification and cooling modules are elaborated. Industrial applications of the techniques are also envisaged using parallel-processing and fast computing facilities for full-scale casting applications.
Solidification processing of scrap Al-alloys containing high levels of Fe
Authors: Lazaro-Nebreda J , Patel J B , Chang I T H , Stone I C , Fan Z
Published: May 2019

The accumulation of iron in molten aluminium is one of the main concerns for the recycling and casting industries because it leads to the formation of undesirable Fe-rich intermetallic compounds which are detrimental to mechanical properties. Many methods have been developed in the past to reduce the iron accumulated in molten aluminium scrap, but they all suffer from poor efficiency. Hence, a more efficient method is urgently needed to mitigate the negative effect of high iron levels in the melt, thereby avoiding downgrading secondary aluminium to low quality products or the dilution with expensive primary aluminium. This contribution provides a study of the Fe-rich intermetallic compounds developed in aluminium casting alloys with high levels of Fe as a function of melt processing conditions. Results show that the formation of the Fe-compounds is not only dependent on the cooling rate and holding time before solidification, but more on the initial melt treatment as it enhances the nucleation and growth of the Fe-phases. Elemental addition of Mn leads to the formation of large and compact intermetallic particles, but at slow rate. Physical melt treatment by intensive high shearing produces a much faster nucleation and results in a fine dispersion of smaller iron containing intermetallic particles. The latter could be used either to increase the tolerance to iron contamination or to facilitate the iron removal process, providing huge benefits for the recyclability of scrap aluminium alloys as it would allow the transformation of low-grade feedstock into a low cost and small carbon footprint material for high quality castings.
Advances in Modeling of Steel Solidification with IDS
Authors: Miettinen J , Louhenkilpi S , Visuri V-V , Fabritius T
Published: May 2019

IDS (Inter-Dendritic Solidification) is a thermodynamic-kinetic software package that simulates phase changes, compound formation/dissolution, and solute distribution during solidification of steels as well as during their cooling/heating process after solidification. The software package also simulates solid-state phase transformations related to the austenite decomposition process at temperatures below 900/600 °C, and calculates thermophysical material properties from the liquid state down to room temperature. These data are needed in other models, such as heat transfer and thermal stress models, whose reliability heavily depends on the input data. The software package also features a database for thermodynamic, kinetic and microstructure data, as well as for several material properties. Owing to the short calculation times, the IDS tool is suitable for online applications. This paper presents IDS and its modules with the latest developments and validations, along with examples of modeling results.
Dendrite growth direction measurements: understanding the solute advancement in continuous casting of steel
Authors: SenGupta A. , Santillana B. , Sridhar S. , Auinger M.
Published: May 2019

Maintaining competitiveness in steel manufacturing requires improving process efficiency and production volume whilst enhancing product quality and performance. This is particularly challenging for producing value-added advanced steel grades such as advanced high strength steels and electrical steels. These grades due to higher weight percentage of alloying elements cause difficulties in various stages of upstream and downstream processing, and this includes continuous casting, wherein high solute levels are critical towards macro-segregation. Interface growth direction in systems with more than one component is dictated by the solute profile ahead of the moving solidification front. Understanding the profile of growth direction with casting process parameters during the progress of casting will provide an important perspective towards reducing the macro-segregation in the cast product. In the present study, two steel slab samples from conventional slab caster under the influence of electromagnetic brake (EMBR) at Tata Steel in IJmuiden (The Netherlands) have been investigated for dendrite deflection measurements. The samples showed a transition zone where a change in the deflection behavior occurs. Also, the magnitude of the deflection angle decreases away from the slab surface. Correlating these experimental data with modeled fluid flow profile will help in improving the understanding of the dynamic nature of the solute advancement so that the casting parameters can be optimized to improve product quality.
Utilizing inclusion data in characterization of oxide-sulfide stringers in hot-rolled plates
Authors: Alatarvas T , Antola T , Fabritius T
Published: May 2019

The targets of this study were to determine the effect of vertical location and the composition of inclusions to the occurrence of oxide–sulfide stringers, and to determine the calcium aluminate phases most prone to form stringers during hot rolling of aluminium killed, calcium treated steel. The phases present in the inclusions have a significant effect on the deformation of inclusions during hot rolling, and consequently, on mechanical properties of the steel. A MATLAB script is utilized to identify and locate detrimental stringers from the hot rolled plates. Inclusion analysis data gathered with a scanning electron microscope and exported from IncaFeature software is analyzed. The following properties are presented for each stringer: the number of inclusions and length of stringer, phase fractions and compositions, and the composition of the unfragmented inclusion before hot rolling. According to the results, the longest stringers have total lengths over 200 µm, with almost 20 inclusions. The overall composition of the longest stringers is between C12A7 and C3A calcium aluminates with minor MgO contents. The diameters of the unfragmented inclusions in the slabs, forming stringers during hot rolling, were estimated to be around 20 µm for the longest stringers. From the dataset, plenty of CaO–CaS stringers were also characterized, obviously a result of excess calcium treatment.
Numerical simulations of liquid steel alloying in the three strand continuous casting bloom tundish
Authors: Cwudziński A
Published: May 2019

This paper aims to obtain fundamental information on chemical homogenisation process of liquid steel with alloy additions in the bloom tundish. For alloy feeding to liquid steel pulse step alloying method was applied. Author checked the effect of hydrodynamic conditions occurs in the internal working space of tundish on the process of alloy mixing with liquid steel. Within the work basic and proposed tundish equipments were considered. Numerical modelling technique was employed to demonstrate the process of alloy addition mixing during continuous casting process. Ansys-Fluent computer program was used for numerical simulation. For particular continuous casting strands time mixing was calculated.
Effect of Pores on Tensile Fracture of Die-cast AlSiMgMn alloys with 3D X-ray μ-CT and FE Simulation
Authors: Zhao H D , Liu F , Yang R S , Sun F Z
Published: May 2019

In this study, the pores in die-cast AlSiMgMn alloys were inspected and reconstructed with high resolution three-dimensional (3D) X-ray micro computed tomograpgy (μ-CT) technique. Finite element (FE) meshes were built with consideration of the pore actural morphorloges from the CT inspection. Based on dutile damage model, the FE simulation of tensile fracture of the alloys was carried out. The simulation results were compared and verified with the tensile of in-situ scanning electron microscopy (SEM). The two results are agreement in the main crack path and pores on the fracture. With the pore-scale simulation, the effects of pore characteristics on the stress distributions and crack initiation and growth during the tensile were analyzed. It was found that the pores of lower sphericity and larger project area in tensile axis direction are prone to form microcracks and promote main crack deflection. The results also show that aggregation of brittle alpha-Fe intermetallics of the alloys also has important influence on the main crack propagation.
On modelling viscoplastic behavior of the solidifying shell in the funnel-type continuous casting mold
Authors: Vakhrushev A , Kharicha A , Wu M , Ludwig A , Nitzl G , Tang Y , Hackl G , Watziger J , Rodrigues C M G
Published: May 2019

As it is known from literature, the metals tend to follow a viscoplastic law at high temperatures. Thereby, based on the authors’ previous developments to simulate the behavior of the equiaxed crystals packed bed, a viscoplastic stress model is applied to the thin slab casting process. The model is reduced to the single phase mixture formulation for faster and robust simulations. In this idea, the solidifying shell represents a ‘creeping solid’ and the Norton-Hoff type stress model is formulated with the model parameters obtained experimentally. A coupling procedure is established to converge the non-linear terms. The influence of the stress model parameters is investigated. Next the model is applied for the simulation of the thin slab casting to improve a previously developed technique: a viscoplastic rheology is applied to calculate the motion of the solidifying melt instead of imposing the velocities of the mush. The simulation results show that the most deformations happen at the funnel part of the mold, causing highest strain rates and the significant drop of the viscoplastic ‘apparent viscosity’ according to the Norton-Hoff law. The solid shell velocities are mostly uniform at the straight parts of the strand but a slight acceleration of the shell is observed along the funnel surface. Strong compression / expansion zones are detected at the funnel part, which could lead to defects formation. The solid shell thickness was successfully predicted as well and compared to the previous work by the authors.
Solid-liquid interfacial energy of Al-Zn solid-solutions in equilibrium with Al-Zn liquid
Authors: Yılmaz E , Erol H , Acer Erol E , Gündüz M
Published: May 2019

The grain boundary groove method has been successfully used to measure solid-liquid interfacial energies, σSL, experimentally for binary eutectic and peritectic systems, multi-component systems as well as pure materials and for opaque materials as well as transparent materials. It was shown that the grain boundary groove method can be use to obtain σSL for any alloy system provided that the prepared alloy sample can be held at the evaluated temperature for a long enough time with a very stable temperature gradient. In order to show the applicability of the groove method to any system, a part of the Al-Zn phase diagram was chosen. Equilibrated grain boundary groove shapes for solid Alα solution (Al-30wt%Zn) in equilibrium with AlZn liquid (Al-60wt%Zn) have been directly observed with a radial heat flow apparatus. The Gibbs-Thomson coefficient, Γ, was determined with a numerical method using observed groove shapes. The measured thermal conductivities of the solid Alα solution and AlZn liquid phases and the temperature gradient in the solid phase at the solid-liquid interface were used for the calculation of Γ and then σSL was determined using the Gibbs-Thomson equation. The grain boundary energy for the same system was also obtained from the observed groove shapes. The results of the work were compared with the results of the related experimental works.
Fragmentation norm and relative quasimorphisms
Authors: Brandenbursky Michael , Kędra Jarek
Published: May 2019

We prove that manifolds with complicated enough fundamental group admit measure-preserving homeomorphisms which have positive stable fragmentation norm with respect to balls of bounded measure.
Random lattices, punctured tori and the Teichmüller distribution
Authors: Martin Gaven
Published: May 2019

The moduli space of lattices of

C

\mathbb {C}

is a Riemann surface of finite hyperbolic area with the square lattice as an origin. We select a lattice from the induced uniform distribution and calculate the statistics of the Teichmüller distance to the origin. This in turn identifies distribution of the distance in Teichmüller space to the central “square” punctured torus in the moduli space of punctured tori. There are singularities in this p.d.f. arising from the topology of the moduli space. We also consider the statistics of the distance in Teichmüller space to the rectangular punctured tori and the p.d.f. and expected distortion of the extremal quasiconformal mappings.
Non-removability of Sierpiński spaces
Authors: Ntalampekos Dimitrios , Wu Jang-Mei
Published: May 2019

We prove that all Sierpiński spaces in

S

n

{\mathbb {S}}^n

,

n
≥
2

n\geq 2

, are non-removable for (quasi)conformal maps, generalizing the result of the first named author [Non-removability of Sierpiński carpets, preprint, 2018]. More precisely, we show that for any Sierpiński space

X
⊂

S

n

X\subset \mathbb {S}^n

there exists a homeomorphism

f
:

S

n

→

S

n

f\colon \mathbb {S}^n\to \mathbb {S}^n

, conformal in

S

n

∖
X

\mathbb {S}^n\setminus X

, that maps

X
X

to a set of positive measure and is not globally (quasi)conformal. This is the first class of examples of non-removable sets in higher dimensions.
Non-left-orderable surgeries on L-space twisted torus knots
Authors: Tran Anh
Published: May 2019

We show that if

K
K

is an L-space twisted torus knot

T

p
,
p
k
±
1

l
,
m

T^{l,m}_{p,pk \pm 1}

with

p
≥
2

p \ge 2

,

k
≥
1

k \ge 1

,

m
≥
1

m \ge 1

, and

1
≤
l
≤
p
−
1

1 \le l \le p-1

, then the fundamental group of the

3
3

-manifold obtained by

r
s

\frac {r}{s}

-surgery along

K
K

is not left-orderable whenever

r
s

≥
2
g
(
K
)
−
1

\frac {r}{s} \ge 2 g(K) -1

, where

g
(
K
)

g(K)

is the genus of

K
K

.
Subconvexity for twisted 𝐿-functions on 𝐺𝐿₃ over the Gaussian number field
Authors: Qi Zhi
Published: May 2019

Let

q
∈

Z

[
i
]

q \in \mathbb {Z} [i]

be prime, and let

χ
\chi

be the primitive quadratic Hecke character modulo

q
q

. Let

π
\pi

be a self-dual Hecke automorphic cusp form for

S
L

3

(

Z

[
i
]
)

\mathrm {SL}_3 (\mathbb {Z} [i] )

, and let

f
f

be a Hecke cusp form for

Γ
0

(
q
)
⊂

S
L

2

(

Z

[
i
]
)

\Gamma _0 (q) \subset \mathrm {SL}_2 (\mathbb {Z} [i])

. Consider the twisted

L
L

-functions

L
(
s
,
π
⊗
f
⊗
χ
)

L (s, \pi \otimes f \otimes \chi )

and

L
(
s
,
π
⊗
χ
)

L (s, \pi \otimes \chi )

on

G
L

3

×

G
L

2

\mathrm {GL}_3 \times \mathrm {GL}_2

and

G
L

3

\mathrm {GL}_3

. We prove the subconvexity bounds
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper L left-parenthesis one half comma pi circled-times f circled-times chi right-parenthesis much-less-than Subscript epsilon comma pi comma f Baseline normal upper N left-parenthesis q right-parenthesis Superscript 5 slash 4 plus epsilon Baseline comma upper L left-parenthesis one half plus i t comma pi circled-times chi right-parenthesis much-less-than Subscript epsilon comma pi comma t Baseline normal upper N left-parenthesis q right-parenthesis Superscript 5 slash 8 plus epsilon">

L

(

1
2

,
π
⊗
f
⊗
χ

)

≪

ε
,
π
,
f

N

(
q

)

5

/

4
+
ε

,

L

(

1
2

+
i
t
,
π
⊗
χ

)

≪

ε
,
π
,
t

N

(
q

)

5

/

8
+
ε

\begin{equation*} L \big (\tfrac 1 2, \pi \otimes f \otimes \chi \big ) \ll _{\, \varepsilon , \pi , f } \mathrm {N} (q)^{5/4 + \varepsilon }, \quad L \big (\tfrac 1 2 + it, \pi \otimes \chi \big ) \ll _{\, \varepsilon , \pi , t } \mathrm {N} (q)^{5/8 + \varepsilon } \end{equation*}

for any

ε
>
0

\varepsilon > 0

.
Sums of Galois representations and arithmetic homology
Authors: Ash Avner , Doud Darrin
Published: May 2019

Let

Γ
0

(
n
,
N
)

\Gamma _0(n,N)

denote the usual congruence subgroup of type

Γ
0

\Gamma _0

and level

N
N

in

SL
(
n
,

Z

)

\text {SL}(n,{\mathbb Z})

. Suppose for

i
=
1
,
2

i=1,2

that we have an irreducible odd

n
n

-dimensional Galois representation

ρ
i

\rho _i

attached to a homology Hecke eigenclass in

H
∗

(

Γ
0

(
n
,

N
i

)
,

M
i

)

H_*(\Gamma _0(n,N_i),M_i)

, where the level

N
i

N_i

and the weight and nebentype making up

M
i

M_i

are as predicted by the Serre-style conjecture of Ash, Doud, Pollack, and Sinnott. We assume that

n
n

is odd, that

N
1

N
2

N_1N_2

is squarefree, and that

ρ
1

⊕

ρ
2

\rho _1\oplus \rho _2

is odd. We prove two theorems that assert that

ρ
1

⊕

ρ
2

\rho _1\oplus \rho _2

is attached to a homology Hecke eigenclass in

H
∗

(

Γ
0

(
2
n
,
N
)
,
M
)

H_*(\Gamma _0(2n,N),M)

, where

N
N

and

M
M

are as predicted by the Serre-style conjecture. The first theorem requires the hypothesis that the highest weights of

M
1

M_1

and

M
2

M_2

are small in a certain sense. The second theorem requires the truth of a conjecture as to what degrees of homology can support Hecke eigenclasses with irreducible Galois representations attached, but no hypothesis on the highest weights of

M
1

M_1

and

M
2

M_2

. This conjecture is known to be true for

n
=
3

n=3

, so we obtain unconditional results for

GL
(
6
)

\text {GL}(6)

. A similar result for

GL
(
4
)

\text {GL}(4)

appeared in an earlier paper.
The DEAD-box RNA helicase Ded1 has a role in the translational response to TORC1 inhibition
Authors: Aryanpur Peyman P. , Renner David M. , Rodela Emily , Mittelmeier Telsa M. , Byrd Aaron , Bolger Timothy A.
Published: May 2019

Ded1 is a DEAD-box RNA helicase with essential roles in translation initiation. It binds to the eukaryotic initiation factor 4F (eIF4F) complex and promotes 48S preinitiation complex assembly and start-site scanning of 5′ untranslated regions of mRNAs. Most prior studies of Ded1 cellular function were conducted in steady-state conditions during nutrient-rich growth. In this work, however, we examine its role in the translational response during target of rapamycin (TOR)C1 inhibition and identify a novel function of Ded1 as a translation repressor. We show that C-terminal mutants of DED1 are defective in down-regulating translation following TORC1 inhibition using rapamycin. Furthermore, following TORC1 inhibition, eIF4G1 normally dissociates from translation complexes and is degraded, and this process is attenuated in mutant cells. Mapping of the functional requirements for Ded1 in this translational response indicates that Ded1 enzymatic activity and interaction with eIF4G1 are required, while homo-oligomerization may be dispensable. Our results are consistent with a model wherein Ded1 stalls translation and specifically removes eIF4G1 from translation preinitiation complexes, thus removing eIF4G1 from the translating mRNA pool and leading to the codegradation of both proteins. Shared features among DED1 orthologues suggest that this role is conserved and may be implicated in pathologies such as oncogenesis.
Fine structure and dynamics of EB3 binding zones on microtubules in fibroblast cells
Authors: Mustyatsa V. V. , Kostarev A. V. , Tvorogova A. V. , Ataullakhanov F. I. , Gudimchuk N. B. , Vorobjev I. A.
Published: May 2019

End-binding (EB) proteins associate with the growing tips of microtubules (MTs)and modulate their dynamics directly and indirectly, by recruiting essential factors to fine-tune MTs for their many essential roles in cells. Previously EB proteins have been shown to recognize a stabilizing GTP/GDP-Pi cap at the tip of growing MTs, but information about additional EB-binding zones on MTs has been limited. In this work, we studied fluorescence intensity profiles of one of the three mammalian EB-proteins, EB3, fused with red fluorescent protein (RFP). The distribution of EB3 on MTs in mouse fibroblasts frequently deviated from single exponential decay and exhibited secondary peaks. Those secondary peaks, which we refer to as EB3-islands, were detected on 56% comets of growing MTs and were encountered once per 44 s of EB3-RFP comet growth time with about 5 s half-lifetime. The majority of EB3-islands in the vicinity of MT tips was stationary and originated from EB3 comets moving with the growing MT tips. Computational modeling of the decoration of dynamic MT tips by EB3 suggested that the EB3-islands could not be explained simply by a stochastic first-order GTP hydrolysis/phosphate release. We speculate that additional protein factors contribute to EB3 residence time on MTs in cells, likely affecting MT dynamics.
Wage Compression within the Firm: Evidence from an Indexation Scheme
Authors: Leonardi Marco , Pellizzari Michele , Tabasso Domenico
Published: May 2019

We revisit the role of labour market institutions by showing how they affect the sharing of firm-specific rents between employers and employees. We look at an Italian wage indexation mechanism (‘Scala Mobile’) that compressed the distribution of wages, imposing real wage increases at the bottom of the distribution. After developing a simplified version of a search model with intra-firm bargaining and on-the-job search, we document that skilled workers received lower wage adjustments when employed at firms with many unskilled workers and they tended to move towards more skill-intensive firms. Moreover, the system drove the least skill-intensive firms out of the market.
Wheat drought tolerance in the field is predicted by amino acid responses to glasshouse-imposed drought
Authors: Yadav Arun K , Carroll Adam J , Estavillo Gonzalo M , Rebetzke Greg J , Pogson Barry J
Published: May 2019

Glasshouse-based metabolic markers predict yield gap-based drought tolerance determined from multiseason and site field trials which could serve as a potential breeding tool for selecting drought-resilient crops.
Ebola Response: A study of the Psychosocial Factors of Preparedness Among Commissioned Corps Officers of the United States Public Health Service
Authors: Sumter Jeffery L , Roberts Jill , Goodrich-Doctor Adrienne , Mason Thomas J
Published: May 2019

Introduction

The purpose of the cross-sectional study was to explore the relationships between occupational and general-self efficacy, and perceived preparedness among Commissioned Corps officers in the United States Public Health Service (Commissioned Corps). Commissioned Corps officers fight to protect the United States from diseases and care for the survivors of natural disasters and terrorist attacks. Commissioned Corps officers play a vital role in the fight to protect the United States from diseases and care for the survivors of natural disasters and terrorist attacks. The Commissioned Corps provided healthcare services in Liberia during the 2014 Ebola crisis that underscored the challenges of emerging diseases in a globalized community. It is imperative that these health professionals maintain a high level of self-efficacy and feel confident in their overall preparedness training as they respond to public health emergencies.

Materials and Methods

This study used assessment instruments derived from Albert Bandura’s concept of self-efficacy to analyze the occupational and general self-efficacy, and perceived preparedness levels of health services officers in the Commissioned Corps. 82 Commissioned Corps officers completed the assessment survey. To date, no study has examined the relationship between these constructs in this population.

Results

There was a statistically significant relationship between feeling confident in one’s Commissioned Corps training and perceived preparedness (rs = 0.55, p < 0.001).

Conclusion

This study reflects the training perceptions and self-beliefs of Commissioned Corps officers, fills an important gap in the empirical research in this population, and advances previous investigations, which suffered from an underrepresentation of female service members.
Incidence of Hyperoxia in Combat Wounded in Iraq and Afghanistan: A Potential Opportunity for Oxygen Conservation
Authors: Schauer Steven G , April Michael D , Naylor Jason F , Mould-Millman Nee-Kofi , Bebarta Vikhyat S , Becker Tyson E , Maddry Joseph K , Ginde Adit A
Published: May 2019

Introduction

Oxygen supplementation is frequently used in critically injured trauma casualties in the combat setting. Oxygen supplies in the deployed setting are limited so excessive use of oxygen may unnecessarily consume this limited resource. We describe the incidence of supraphysiologic oxygenation (hyperoxia) within casualties in the Department of Defense Trauma Registry (DoDTR).

Methods

This is a subanalysis of previously published data from the DoDTR – we isolated casualties with a documented arterial blood gas (ABG) and categorized hyperoxia as an arterial oxygen >100 mmHg and extreme hyperoxia > 300 mmHg (a subset of hyperoxia). We defined serious injuries as those with an Abbreviated Injury Score (AIS) of 3 or greater. We defined a probable moderate traumatic brain injury of those with an AIS of 3 or greater for the head region and at least one Glasgow Coma Scale at 8 or less.

Results

Our initial search yielded 28,222 casualties, of which 10,969 had at least one ABG available. Within the 10,969, the proportion of casualties experiencing hyperoxia in this population was 20.6% (2,269) with a subset of 4.1% (452) meeting criteria for extreme hyperoxia. Among those with hyperoxia, the median age was 25 years (IQR 21–30), most were male (96.8%), most frequently US forces (41.4%), injured in Afghanistan (68.3%), injured by explosive (61.1%), with moderate injury scores (median 17, IQR 10–26), and most (93.8%) survived to hospital discharge. A total of 17.8% (1,954) of the casualties underwent endotracheal intubation: 27.5% (538 of 1,954) prior to emergency department (ED) arrival and 72.5% (1,416 of 1,954) within the ED. Among those intubated in the prehospital setting, upon ED arrival 35.1% (189) were hyperoxic, and a subset of 5.6% (30) that were extremely hyperoxic. Among those intubated in the ED, 35.4% (502) were hyperoxic, 7.9% (112) were extremely hyperoxic. Within the 1,277 with a probable TBI, 44.2% (565) experienced hyperoxia and 9.5% (122) met criteria for extreme hyperoxia.

Conclusions

In our dataset, more than 1 in 5 casualties overall had documented hyperoxia on ABG measurement, 1 in 3 intubated casualties, and almost 1 in 2 TBI casualties. With limited oxygen supplies in theater and logistical challenges with oxygen resupply, efforts to avoid unnecessary oxygen supplementation may have material impact on preserving this scarce resource and avoid potential detrimental clinical effects from supraphysiologic oxygen concentrations.
Prosthetic Mesh for the Prevention of Parastomal Hernias
Authors: Pich Jacqueline
Published: May 2019

Editor's note: This is a summary of a nursing care–related systematic review from the Cochrane Library. For more information, see http://nursingcare.cochrane.org.
A thermoporoelastic model for fluid transport in tumour tissues
Authors: Andreozzi Assunta , Iasiello Marcello , Netti Paolo Antonio
Published: May 2019

In this paper, the effect of coupled thermal dilation and stress on interstitial fluid transport in tumour tissues is evaluated. The tumour is modelled as a spherical deformable poroelastic medium embedded with interstitial fluid, while the transvascular fluid flow is modelled as a uniform distribution of fluid sink and source points. A hyperbolic-decay radial function is used to model the heat source generation along with a rapid decay of tumour blood flow. Governing equations for displacement, fluid flow and temperature are first scaled and then solved with a finite-element scheme. Results are compared with analytical solutions from the literature, while results are presented for different scaling parameters to analyse the various physical phenomena. Results show that temperature affects pressure and velocity fields through the deformable medium. Finally, simulations are performed by assuming that the heat source is periodic, in order to assess the extent to which this condition affects the velocity field. It is reported that in some cases, especially for periodic heating, the combination of thermoelastic and poroelastic deformation led to no monotonic pressure distribution, which can be interesting for applications such as macromolecule drug delivery, in which the advective contribution is very important owing to the low diffusivity.
Passive cervical spine ligaments provide stability during head impacts
Authors: Kuo Calvin , Sheffels Jodie , Fanton Michael , Yu Ina Bianca , Hamalainen Rosa , Camarillo David
Published: May 2019

It has been suggested that neck muscle strength and anticipatory cocontraction can decrease head motions during head impacts. Here, we quantify the relative angular impulse contributions of neck soft tissue to head stabilization using an OpenSim musculoskeletal model with Hill-type muscles and rate-dependent ligaments. We simulated sagittal extension and lateral flexion mild experimental head impacts performed on 10 subjects with relaxed or cocontracted muscles, and median American football head impacts. We estimated angular impulses from active muscle, passive muscle and ligaments during head impact acceleration and deceleration phases. During the acceleration phase, active musculature produced resistive angular impulses that were 30% of the impact angular impulse in experimental impacts with cocontracted muscles. This was reduced below 20% in football impacts. During the deceleration phase, active musculature stabilized the head with 50% of the impact angular impulse in experimental impacts with cocontracted muscles. However, passive ligaments provided greater stabilizing angular impulses in football impacts. The redistribution of stabilizing angular impulses results from ligament and muscle dependence on lengthening rate, where ligaments stiffen substantially compared to active muscle at high lengthening rates. Thus, ligaments provide relatively greater deceleration impulses in these impacts, which limit the effectiveness of muscle strengthening or anticipated activations.
Growth and metabolic characterization of four lactic acid bacteria species isolated from rice beer prepared in Assam, India
Authors: Das Arup Jyoti , Das Manas Jyoti , Miyaji Tatsuro , Deka Sankar Chandra
Published: May 2019

Isolation and identification of lactic acid bacteria (LAB) from rice beer prepared in Assam, India was performed and their growth associated and functional properties were studied. LAB strains were identified as

Lactobacillus casei

,

Pediococcus pentosaceus

,

Lactobacillus pentosus

and

Lactobacillus plantarum

based on 16 s rRNA sequencing. Their growth characteristics at different pH, NaCl concentration, temperature and presence of carbohydrates were profiled. High tolerance against acid and bile salts was shown by all the strains, particularly

L. pentosus

TEZU174 and

P. pentosaceus

TEZU199 up to a pH of 1.5, and

L. pentosus

TEZU174 up to 14  % bile concentration. They were susceptible towards the common antibiotics, wherein erythromycin, chloramphenicol and linezolid were the most effective. The strains displayed antibiosis activity against

Escherichia coli

and

Staphylococcus aureus

and antioxidant activity in terms of resistance to H2O2, scavenging of ·OH and DPPH free radicals was also displayed, wherein

L. casei

TEZU374 and

P. pentosaceus

TEZU482 were the most effective with above 70  % scavenging activity. The strains displayed cellular aggregation and

L. casei

TEZU262 and

L. casei

TEZU309 were highly aggregated, which attained 100  % autoaggregation within a period of 5 h. High cell surface hydrophobicity was shown by

L. casei

TEZU309 towards xylene and chloroform, and

P. pentosaceus

TEZU427 towards ethyl acetate. The strains evinced good gut tolerance capacity, antioxidant activity and adherence properties, which are characteristics of probiotic bacteria and thus are candidates for therapeutic uses and also to be used as starter cultures.
CReasPy-cloning: a method for simultaneous cloning and engineering of megabase-sized genomes in yeast using the CRISPR-Cas9 system
Authors: Ruiz Estelle , Talenton Vincent , Dubrana Marie-Pierre , Guesdon Gabrielle , Lluch-Senar Maria , Salin Franck , Sirand-Pugnet Pascal , Arfi Yonathan , Lartigue Carole
Published: May 2019

Over the last decade a new strategy was developed to bypass the difficulties to genetically engineer some microbial species by transferring (or “cloning”) their genome into another organism that is amenable to efficient genetic modifications and therefore acts as a living workbench. As such, the yeastSaccharomyces cerevisiaehas been used to clone and engineer genomes from viruses, bacteria and algae. The cloning step requires the insertion of yeast genetic elements within the genome of interest, in order to drive its replication and maintenance as an artificial chromosome in the host cell. Current methods used to introduce these genetic elements are still unsatisfactory, due either to their random nature (transposon) or the requirement for unique restriction sites at specific positions (TAR cloning). Here we describe the CReasPy-Cloning, a new method that combines both the ability of Cas9 to cleave DNA at a user-specified locus and the yeast’s highly efficient homologous recombination to simultaneously clone and engineer a bacterial chromosome in yeast. Using the 0.816 Mbp genome ofMycoplasma pneumoniaeas a proof of concept, we demonstrate that our method can be used to introduce the yeast genetic element at any location in the bacterial chromosome while simultaneously deleting various genes or group of genes. We also show that CReasPy-cloning can be used to edit up to three independent genomic loci at the same time with an efficiency high enough to warrant the screening of a small (<50) number of clones, allowing for significantly shortened genome engineering cycle times.
Codon Use and Aversion is Largely Phylogenetically Conserved Across the Tree of Life
Authors: Miller Justin B. , McKinnon Lauren M. , Whiting Michael F. , Ridge Perry G.
Published: May 2019

Using parsimony, we analyzed codon usages across 12 337 species and 25 727 orthologous genes to rank specific genes and codons according to their phylogenetic signal. We examined each codon within each ortholog to determine the codon usage for each species. In total, 890 814 codons were parsimony informative. Next, we compared species that used a codon with species that did not use the codon. We assessed each codon’s congruence with species relationships provided in the Open Tree of Life (OTL) and determined the statistical probability of observing these results by random chance. We determined that 25 771 codons had no parallelisms or reversals when mapped to the OTL. Codon usages from orthologous genes spanning many species were 1 109x more likely to be congruent with species relationships in the OTL than would be expected by random chance. Using the OTL as a reference, we show that codon usage is phylogenetically conserved within orthologous genes in archaea, bacteria, plants, mammals, and other vertebrates. We also show how to use our provided framework to test different tree hypotheses by confirming the placement of turtles as sister taxa to archosaurs.

Availability

All scripts, a README, and necessary test files are freely available on GitHub at https://github.com/ridgelab/codon_congruence

Contact

perry.ridge@byu.edu
The plasma Factor XIII heterotetrameric complex structure: unexpected unequal pairing within a symmetric complex
Authors: Singh Sneha , Nazabal Alexis , Kaniyappan Senthilvelrajan , Pellequer Jean-Luc , Wolberg Alisa S. , Imhof Diana , Oldenburg Johannes , Biswas Arijit
Published: May 2019

Factor XIII (FXIII) is a predominant determinant of clot stability, strength, and composition. Plasma FXIII circulates as a pro-transglutaminase with 2 catalytic A subunits and 2 carrier-protective B subunits in a heterotetramer (FXIII-A2B2). FXIII-A2and -B2subunits are synthesized separately and then assembled in plasma. Following proteolytic activation by thrombin and calcium-mediated dissociation of the B-subunits, activated FXIII (FXIIIa) covalently cross-links fibrin, promoting clot stability. The zymogen and active states of the FXIII-A subunits have been structurally characterized; however, the structure of FXIII-B subunits and the FXIII-A2B2complex have remained elusive. Using integrative hybrid approaches including atomic force microscopy, cross-linking mass spectrometry, and computational approaches, we have constructed the first all-atom model of the FXIII-A2B2complex. We also used molecular dynamic simulations in combination with isothermal titration calorimetry to characterize FXIII-A2B2assembly, activation, and dissociation. Our data reveal unequal pairing of individual subunit monomers in an otherwise symmetric complex, and suggest this unusual structure is critical for both assembly and activation of this complex. Our findings enhance understanding of mechanisms associating FXIII-A2B2mutations with disease and have important implications for the rational design of molecules to alter FXIII assembly and/or activity to reduce bleeding and thrombotic complications.
Brain age estimation is a sensitive marker of processing speed in the early course of multiple sclerosis
Authors: Høgestøl Einar A. , Nygaard Gro O. , Emhjellen Petter E. , Kaufmann Tobias , Beyer Mona K. , Sowa Piotr , Andreassen Ole A. , Celius Elisabeth G. , Landrø Nils Inge , Westlye Lars T. , Harbo Hanne F.
Published: May 2019

Background and objectives

Cognitive deficits in MS are common, also early in the disease course. We aimed to identify if estimated brain age from MRI could serve as an imaging marker for early cognitive symptoms in a longitudinal MS study.

Methods

A group of 76 MS patients (mean age 34 years, 71% females, 96% relapsing-remitting) was examined 1, 2 and 5 years after diagnosis. A machine-learning model using Freesurfer-processed T1-weighted brain MRI data from 3208 healthy controls, was applied to develop a prediction model for brain age. The difference between estimated and chronological brain age was calculated (brain age gap). Tests of memory, attention and executive functions were performed. Associations between brain age gap and cognitive performance were assessed using linear mixed effects (LME) models and corrected for multiple testing.

Results

LME models revealed a significant association between the Color Naming condition of Color-Word Interference Test and brain age gap (t=2.84, p=0.005).

Conclusions

In this study, decreased information processing speed correlated with increased brain age gap. Our findings suggest that brain age estimation using MRI provides a useful semi-automated approach applying machine learning for individual level brain phenotyping and correlates with information processing speed in the early course of MS.
Selective autophagy, lipophagy and mitophagy, in the Harderian gland along the estrous cycle: a potential retrieval effect of melatonin
Authors: García-Macia Marina , Santos-Ledo Adrián , Caballero Beatriz , Rubio-González Adrián , de Luxán-Delgado Beatriz , Potes Yaiza , Rodríguez-González Susana , Boga José Antonio , Coto-Montes Ana
Published: May 2019

Sexual dimorphism has been reported in many processes. However, sexual bias in favor of the use of males is very present in science. One of the main reasons is that the impact of hormones in diverse pathways and processes such as autophagy have not been properly addressed in vivo. The Harderian gland is a perfect model to study autophagic modulation as it exhibits important changes during the estrous cycle. The aim of this study is to identify the main processes behind Harderian gland differences under estrous cycle and their modulator. In the present study we show that redox-sensitive transcription factors have an essential role: NF-κB may activate SQSTM1/p62 in estrus, promoting selective types of autophagy: mitophagy and lipophagy. Nrf2 activation in diestrus, leads the retrieval phase and restoration of mitochondrial homeostasis. Melatonin’s receptors show higher expression in diestrus, leading to decreases in pro-inflammatory mediators and enhanced Nrf2 expression. Consequently, autophagy is blocked, and porphyrin release is reduced. All these results point to melatonin as one of the main modulators of the changes in autophagy during the estrous cycle.
Costs and benefits of giant sperm and sperm storage organs in Drosophila melanogaster
Authors: Zajitschek Susanne , Zajitschek Felix , Josway Sarah , Al Shabeeb Reem , Weiner Halli , Manier Mollie K.
Published: May 2019

In the Drosophila lineage, both sperm and the primary female sperm storage organ, the seminal receptacle (SR), may reach extraordinary lengths. In D. melanogaster, long SRs bias fertilization toward long sperm during the displacement stage of sperm competition. This sperm-SR interaction, together with a genetic correlation between the traits, suggests that the coevolution of exaggerated sperm and SR lengths may be driven by Fisherian runaway selection. To further understand the costs and benefits of long sperm and SR genotypes in both sexes, we measured male and female fitness in inbred lines of D. melanogaster derived from four populations previously selected for long sperm, short sperm, long SRs, or short SRs. We specifically asked: do long SRs impose costs or benefits on the females that bear them? Do genotypes that generate long sperm in males impose a fitness cost on females sharing those genotypes? Is long sperm an honest indicator of male viability and associated with increased fitness? And finally, are the benefits of long sperm restricted to competitive fertilization success, or do long-sperm males also have increased mating success and fecundity in single matings? We found that both sexes have increased longevity in long sperm and long SR genotypes, with fewer reproduction-related benefits and evidence for trade-offs in males, compared to females. Our results suggest that sperm length and SR length are both indicators of increased viability.
Deletion of beta-fructofuranosidase (invertase) genes is associated with sucrose content in Date Palm fruit
Authors: Malek Joel A. , Mathew Sweety , Mathew Lisa , Younuskunju Shameem , Mohamoud Yasmin A. , Suhre Karsten
Published: May 2019

The fruit of date palm trees are an important part of the diet for a large portion of the Middle East and North Africa. The fruit is consumed both fresh and dry and can be stored dry for extended periods of time. Date fruits vary significantly across hundreds of cultivars identified in the main regions of cultivation. Most dried date fruit are low in sucrose but high in glucose and fructose. However, high sucrose content is a distinctive feature of some date fruit and affects flavor as well as texture and water retention. To identify the genes controlling high sucrose content we analyzed date fruit metabolomics for association with genotype data from 121 date fruits. We found significant association of dried date sucrose content and a genomic region that contains 3 tandem copies of the beta-fructofuranosidase (invertase) gene in the reference Khalas genome, a low sucrose fruit. High sucrose cultivars including the popular Deglet Noor had a homozygous deletion of two of the 3 copies of the invertase gene. We show the deletion allele is derived when compared to the ancestral allele that retains the all copies of the gene in 3 other species of Phoenix. The fact that 2 of the 3 tandem invertase copies are associated with dry fruit sucrose content will assist in better understanding the distinct roles of multiple date palm invertases in plant physiology. Identification of the recessive alleles associated with end-point sucrose content in date fruit may be used in selective breeding in the future.
G-quadruplexes sequester free heme in living cells
Authors: Gray Lucas T. , Lombardi Emilia Puig , Verga Daniela , Guetta Corinne , Nicolas Alain , Teulade-Fichou Marie-Paule , Londoño-Vallejo Arturo , Maizels Nancy
Published: May 2019

Heme is an essential cofactor for many enzymes, but free heme is toxic and its levels are tightly regulated. G-quadruplexes bind heme avidlyin vitro, raising the possibility that they may sequester hemein vivo. If so, then treatment that displaces heme from quadruplexes is predicted to induce expression of genes involved in iron and heme homeostasis. Here we show that PhenDC3, a G-quadruplex ligand structurally unrelated to heme, displaces quadruplex-bound hemein vitroand alters transcription in cultured human cells, up-regulating genes that support heme degradation and iron homeostasis, and most strikingly causing a 30-fold induction of heme oxidase 1, the key enzyme in heme degradation. We propose that G-quadruplexes sequester heme to protect cells from the pathophysiological consequences of free heme. This identifies a new function for G-quadruplexes and a new mechanism for protection of cells from heme.