bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of strain rate on hot tear formation in Al-Si-Cu alloys
Authors: Bhagavath S , Cai B , Atwood R , Lee PD , Karagadde S 
Published: May 2019

Abstract
The alloy casting process is one of the major manufacturing processes to produce near net shape components. The casing process is prone to a wide variety of defects, with hot tear being one of the most detrimental. The two main factors generally recognized as the primary cause for formation of hot tears are the mechanical response of the mush (which effects its permeability), and the solidification range (solidification time). The response of the mushy zone under deformation is mainly affected by the solid fraction, strain rate and grain morphology. Even though the science behind the formation of hot tear is understood, there is no general criterion to quantify the hot tear formation under varying casting conditions. The development of ultra-fast X-ray imaging has facilitated the means to quantify the effects of the critical parameters in-situ and develop better correlations for hot tear prediction. The in situ experiments will also provide insights into mush rheology, which has significant influence on hot tear formation. In this study, isothermal semi solid compression studies of Al-Si-Cu alloys were carried out using specially built thermo-mechanical rig. We studied the effects of the strain rate in the range of 2 × 10-4–0.02/s and solid fraction (∼0.6-0.9) on the mechanical response of the mushy zone. The sample were characterized before and after deformation using X-ray micro tomography. The data was subjected to an image processing routine and the amount of porosity and hot tear was quantified. The stress-strain curve of the semisolid alloys showed a characteristic strain softening behaviour for semi solid samples with ∼0.6-0.7 solid fraction, irrespective of loading rates, whereas the behaviour at higher fractions were that of constant flow stress. Additionally, in situ compression experiments were carried out, wherein the liquid channel thickness at various strain values were measured. Isolated liquid channels were formed under loading, from where the hot tears were found to nucleate. Hot tear susceptibility was found to increase with increasing strain rate and rheology of the mush, which is dependent on solid fraction.
Using morphology-equivalent method to simulate the evolution of shrinkage in Ti6Al4V alloy castings during HIP
Authors: Xu Q , Zhou J X , Li W , Feng X , Nan H , Yin Y J 
Published: May 2019

Abstract
Hot isostatic pressing(HIP) is an effective method to eliminate the shrinkage in castings. The morphology of shrinkage is complex, and there are structures such as sharp corners and small passages which would lead to a large number of elements and easily divergent calculation results. Therefore, the application of numerical simulation in HIP is limited. To solve the non-convergence problem, the real shrinkage is often simplified as a sphere. However, this simplification ignores the characteristics of the shrinkage and makes the simulation results unreliable. In this paper, the technique of morphology-equivalent ellipsoid is applied to the numerical simulation of shrinkage evolution during HIP. Firstly, the 3D morphology of shrinkage in Ti6Al4V alloy castings is obtained by micro computed tomography. The radius of sphere and the geometric size and orientation of morphology-equivalent ellipsoid are calculated by corresponding equivalent techniques. Secondly, the numerical simulations of HIP for the Ti6Al4V castings before and after the equivalent method are carried out. The volume evolution of three kinds of shrinkages are recorded and compared. The results show that the volume evolution of the morphology-equivalent ellipsoid is closer to that of the real shrinkage, the feasibility of the morphology-equivalent ellipsoid and the limitations of sphere are verified.
Numerical Simulations of Electromagnetic Counteractions to Mold Fluid Flow Asymmetry Deviations
Authors: Sedén Martin , Rydholm Bengt 
Published: May 2019

Abstract
Asymmetric flow of the molten steel in a continuous slab casting mold may be detrimental to the quality of the solidified end product. Depending on the severity of the biased flow, local mold powder entrainment, non-homogeneous solidification around the perimeter of the initial shell or non-optimal inclusion seclusion may occur. In particular, nozzle clogging in the last slabs before an SEN exchange may cause strong and asymmetries in the upper regions of the mold. To avoid costly downgrades of steel quality in these slabs, it is vital to maintain stable and symmetric fluid flow conditions in the mold. The EMBR and the FC Mold are two flexible electromagnetic devices able to produce asymmetric braking/stirring along the width of the mold in slab casting, and in this way allow counteraction against e.g. biased mold flow or local excessive flow speeds. Numerical computations of mold fluid flow and magnetic flux have been carried out to quantify the required fields to symmetrize biased flow scenarios caused by e.g. SEN clogging. In conjunction with steel plant trial feedback, the simulation results have been used to setup control algorithms for the EMBR and FC Mold.
Effect of different process parameters on non-metallic inclusions during electro-slag remelting of a tempering steel
Authors: Schneider R , Schroft S , Molnar M , Klösch G , Schüller C 
Published: May 2019

Abstract
The remelting behavior of the tempering steel 50CrMo4, was investigated with several experimental melts on a lab-scale ESR-plant. The investigated parameters included a variation of the slag compositions and the use of a protective nitrogen atmosphere. Variations of the slag composition comprised slags with different contents of CaF2, CaO and Al2O3 as well as a variation of the SiO2-content. The remelted ingots were forged and analyzed regarding their chemical composition as well as their distribution and composition of the non-metallic inclusions (NMI) by automated SEM-EDX method. The chemical composition of the slag after remelting was analyzed as well. The results clearly show a relationship mainly of Si and Al in the steel with the process parameters. NMI changed in their total amount, type and size distribution. The protective atmosphere reduced the Si-losses during remelting. The majority of the NMI were of the Al2O3- & MnS-type. In general, remelting lead to an almost complete removal of sulfides, a reduction of oxisulfides and a shift towards more oxides. The total amount of NMI was most strongly reduced by the high CaF2-containing remelting slag.
Boundary value problems in Lipschitz domains for equations with lower order coefficients
Authors: Sakellaris Georgios 
Published: May 2019

We use the method of layer potentials to study the

R
2

R_2

regularity problem and the

D
2

D_2

Dirichlet problem for second order elliptic equations with lower order coefficients in bounded Lipschitz domains. For

R
2

R_2

we establish existence and uniqueness by assuming that

L

\mathcal {L}

is of the form

L

u
=
−
div
(
A
∇
u
+
b
u
)
+
c
∇
u
+
d
u

\mathcal {L}u=-\text {div}(A\nabla u+bu)+c\nabla u+du

, where the matrix

A
A

is uniformly elliptic and Hölder continuous,

b
b

is Hölder continuous, and

c
,
d

c,d

belong to Lebesgue classes and satisfy either the condition

d
≥

div

b

d\geq \ \text {div}\,b

or

d
≥

div

c

d\geq \ \text {div}\,c

in the sense of distributions. In particular,

A
A

is not assumed to be symmetric, and there is no smallness assumption on the norms of the lower order coefficients. We also show existence and uniqueness for

D
2

D_2

for the adjoint equations

L

t

u
=
0

\mathcal {L}^tu=0

.
Testosterone Replacement Therapy and the Risk of Prostate Cancer in Men With Late-Onset Hypogonadism
Authors: Santella Christina , Renoux Christel , Yin Hui , Yu Oriana H Y , Azoulay Laurent 
Published: May 2019

Abstract
The association between the use of testosterone replacement therapy (TRT) and prostate cancer remains uncertain. Thus, we investigated whether TRT is associated with an increased risk of prostate cancer in men with late-onset hypogonadism. We used the UK Clinical Practice Research Datalink to assemble a cohort of 12,779 men who were newly diagnosed with hypogonadism between January 1, 1995, and August 31, 2016, with follow-up until August 31, 2017. Exposure to TRT was treated as a time-varying variable and lagged by 1 year to account for cancer latency, with nonuse as the reference category. During 58,224 person-years of follow-up, a total of 215 patients were newly diagnosed with prostate cancer, generating an incidence rate of 3.7 per 1,000 person-years. In time-dependent Cox proportional hazards models, use of TRT was not associated with an overall increased risk of prostate cancer (hazard ratio = 0.97; 95% confidence interval: 0.71, 1.32) compared with nonuse. Results remained consistent in secondary and sensitivity analyses, as well as in a propensity score–matched cohort analysis that further assessed the impact of residual confounding. Overall, the use of TRT was not associated with an increased risk of prostate cancer in men with late-onset hypogonadism.
Signs of Friendship: A Response to Alexander Nehamas’s ‘The Good of Friendship’
Authors: Gibson Richard Hughes 
Published: May 2019

Abstract
This piece responds to Alexander Nehamas’s claim in ‘The Good of Friendship’ (2010) that painting has difficulty representing friendship, an issue exemplified for Nehamas by Jacopo Pontormo’s double portrait Two Friends (c.1522). I argue that friendship has not been as elusive for the painter as Nehamas suggests, using as a counter-example Quentin Massys’s diptych of Erasmus and Pieter Gillis (1517). My exposition of Massys’s picture, moreover, reveals dimensions of modern friendship, particularly its concerns for communications media and publicity, neglected by Nehamas’s account.
Spatiotemporal variation in thermal niches suggests lability rather than conservatism of thermal physiology along an environmental gradient
Authors: Gilbert Anthony L , Miles Donald B 
Published: May 2019

Abstract
Temperature variation throughout a species range can be extensive and exert divergent spatiotemporal patterns of selection. The estimation of phenotypic differences of populations along environmental gradients provides information regarding population-level responses to changing environments and evolutionary lability in climate-relevant traits. However, few studies have found physiological differentiation across environmental gradients attributable to behavioural thermoregulation buffering physiological evolution. Here, we compared thermal sensitivity of physiological performance among three populations of the ornate tree lizard (Urosaurus ornatus) along a 1100 m elevational gradient in southeastern Arizona across years in order to determine whether spatial differences in thermal environments are capable of driving local physiological differentiation. Lizards exhibited significant population-level differences in thermal physiology. The thermal traits of lizards at low elevations included warmer body temperatures and higher preferred and critical thermal temperatures. In contrast, lizards at higher elevations had cooler body temperatures and lower preferred and critical thermal temperatures. Populations also exhibited differences in the optimal temperature for performance and thermal performance breadth. The direction of population variation was consistent across years. Environmental gradients can provide model systems for studying the evolution of thermal physiology, and our study is one of the first to suggest that population differentiation in thermal physiology could be more prominent than previously thought.
Generalized meta-analysis for multiple regression models across studies with disparate covariate information
Authors: Kundu Prosenjit , Tang Runlong , Chatterjee Nilanjan 
Published: May 2019

Summary
Meta-analysis is widely popular for synthesizing information on common parameters of interest across multiple studies because of its logistical convenience and statistical efficiency. We develop a generalized meta-analysis approach to combining information on multivariate regression parameters across multiple studies that have varying levels of covariate information. Using algebraic relationships among regression parameters in different dimensions, we specify a set of moment equations for estimating parameters of a maximal model through information available from sets of parameter estimates for a series of reduced models from the different studies. The specification of the equations requires a reference dataset for estimating the joint distribution of the covariates. We propose to solve these equations using the generalized method of moments approach, with the optimal weighting of the equations taking into account uncertainty associated with estimates of the parameters of the reduced models. We describe extensions of the iterated reweighted least-squares algorithm for fitting generalized linear regression models using the proposed framework. Based on the same moment equations, we also develop a diagnostic test for detecting violations of underlying model assumptions, such as those arising from heterogeneity in the underlying study populations. The proposed methods are illustrated with extensive simulation studies and a real-data example involving the development of a breast cancer risk prediction model using disparate risk factor information from multiple studies.
Predictors of Unlikely Bacterial Pneumonia and Adverse Pneumonia Outcome in Children Admitted to a Hospital in Central Vietnam
Authors: Nguyen Phuong T K , Tran Hoang T , Tran Thach S , Fitzgerald Dominic A , Graham Stephen M , Marais Ben J 
Published: May 2019

Abstract

Background
Pneumonia is the leading cause of antibiotic use and hospitalization in Vietnam. There is a need for better prediction of unlikely bacterial pneumonia and adverse pneumonia outcome in order to guide hospital admission and improve rational antibiotic use.

Methods
All children under 5 admitted with pneumonia (per clinician assessment) to the Da Nang Hospital for Women and Children were prospectively enrolled. Children were classified as having likely or unlikely bacterial pneumonia and followed for outcome assessment. A Bayesian model averaging approach was used to identify predictors of unlikely bacterial pneumonia and adverse pneumonia outcome, which guided the development of a pragmatic management algorithm.

Results
Of 3817 patients assessed, 2199 (57.6%) met World Health Organization (WHO) pneumonia criteria. In total, 1594 (41.7%) children were classified as having unlikely and 129 (3.4%) as having likely bacterial pneumonia. The remainder (2399; 62.9%) were considered to have disease of uncertain etiology. Factors predictive of unlikely bacterial pneumonia were no fever, no consolidation on chest radiograph, and absolute neutrophil count &lt;5 × 109/L at presentation, which had a negative predictive value (NPV) for likely bacterial pneumonia of 99.0%. Among those who met WHO pneumonia criteria, 8.6% (189/2199) experienced an adverse outcome. Not having any WHO danger sign or consolidation on chest radiograph had an NPV of 96.8% for adverse pneumonia outcome.

Conclusions
An algorithm that screens for predictors of likely bacterial pneumonia and adverse pneumonia outcome could reduce unnecessary antibiotic use and hospital admission, but its clinical utility requires validation in a prospective study.
Behavior-Obfuscation Resistance Malware Detection
Authors: Cheng Binlin , Liu Jinjun , Chen Jiejie , Shi Shudong , Peng Xufu , Zhang Xingwen , Hai Haiqing 
Published: May 2019

Abstract
Malware brings a big security threat on the Internet today. With the great increasing malware attacks. Behavior-based detection approaches are one of the major method to detect zero-day malware. Such approaches often use API calls to represent the behavior of malware. Unfortunately, behavior-based approaches suffer from behavior obfuscation attacks. In this paper, we propose a novel malware detection approach that is both effective and efficient. First, we abstract the API call to object operation. And then we generate the object operation dependency graph based on these object operations. Our approach use dependency graph to represent the behavior of malware. The evaluation results show that our approach can provide a complete resistance to all types of behavior obfuscation attacks, and outperforms existing behavior-based approaches in terms of better effectiveness and efficiency.
Descending aortic replacement for intimal angiosarcoma
Authors: Yokawa Koki , Inoue Takeshi , Yamanaka Katsuhiro , Okada Kenji 
Published: May 2019

Abstract
Aortic angiosarcoma is an exceedingly rare clinical entity. A significant delay in diagnosis can occur due to its rareness and lack of specific clinical manifestation. A 71-year-old woman was admitted to the emergency department owing to an acute episode of abdominal pain. A computed tomography (CT) scan showed thoraco-abdominal aortic occlusion and splenic infarction. The patient was initially treated with descending aortic replacement for degenerative atherothrombotic aneurysm. An FDG-positron emission tomography-CT scan and biopsy ultimately confirmed the diagnosis of aortic angiosarcoma. This case highlights the difficulties of making an early diagnosis of aortic angiosarcoma.
BSA4Yeast: Web-based quantitative trait locus linkage analysis and bulk segregant analysis of yeast sequencing data
Authors: Zhang Zhi , Jung Paul P , Grouès Valentin , May Patrick , Linster Carole , Glaab Enrico 
Published: May 2019

Abstract

Background
Quantitative trait locus (QTL) mapping using bulk segregants is an effective approach for identifying genetic variants associated with phenotypes of interest in model organisms. By exploiting next-generation sequencing technology, the QTL mapping accuracy can be improved significantly, providing a valuable means to annotate new genetic variants. However, setting up a comprehensive analysis framework for this purpose is a time-consuming and error-prone task, posing many challenges for scientists with limited experience in this domain.

Results
Here, we present BSA4Yeast, a comprehensive web application for QTL mapping via bulk segregant analysis of yeast sequencing data. The software provides an automated and efficiency-optimized data processing, up-to-date functional annotations, and an interactive web interface to explore identified QTLs.

Conclusions
BSA4Yeast enables researchers to identify plausible candidate genes in QTL regions efficiently in order to validate their genetic variations experimentally as causative for a phenotype of interest. BSA4Yeast is freely available at https://bsa4yeast.lcsb.uni.lu.
Evolution of, and via, Developmental Plasticity: Insights through the Study of Scaling Relationships
Authors: Casasa Sofia , Moczek Armin P 
Published: May 2019

AbstractScaling relationships emerge from differential growth of body parts relative to each other. As such, scaling relationships are at least in part the product of developmental plasticity. While some of the developmental genetic mechanisms underlying scaling relationships are starting to be elucidated, how these mechanisms evolve and give rise to the enormous diversity of allometric scaling observed in nature is less understood. Furthermore, developmental plasticity has itself been proposed as a mechanism that facilitates adaptation and diversification, yet its role in the developmental evolution of scaling relationships remains largely unknown. In this review, we first explore how the mechanisms of scaling relationships have evolved. We primarily focus on insect development and review how pathway components and pathway interactions have evolved across taxa to regulate scaling relationships across diverse traits. We then discuss the potential role of developmental plasticity in the evolution of scaling relationships. Specifically, we address the potential role of allometric plasticity and cryptic genetic variation in allometry in facilitating divergence via genetic accommodation. Collectively, in this article, we aim to bring together two aspects of developmental plasticity: the mechanistic underpinnings of scaling relationships and their evolution, and the potential role that plasticity plays in the evolutionary diversification of scaling relationships.
On the Refined Conjectures on Fitting Ideals of Selmer Groups of Elliptic Curves with Supersingular Reduction
Authors: Kim Chan-Ho , Kurihara Masato 
Published: May 2019

AbstractIn this paper, we study the Fitting ideals of Selmer groups over finite subextensions in the cyclotomic $\mathbb{Z}_p$-extension of $\mathbb{Q}$ of an elliptic curve over $\mathbb{Q}$. Especially, we present a proof of the “weak main conjecture” à la Mazur and Tate for elliptic curves with good (supersingular) reduction at an odd prime $p$. We also prove the “strong main conjecture” suggested by the second named author under the validity of the $\pm $-main conjecture and the vanishing of a certain error term. The key idea is the explicit comparison among “finite layer objects”, “$\pm $-objects”, and “fine objects” in Iwasawa theory. The case of good ordinary reduction is also treated.
Antiretroviral drug reduction in highly experienced HIV-infected patients receiving a multidrug regimen: the ECOVIR study
Authors: Valantin Marc-Antoine , Durand Lise , Wirden Marc , Assoumou Lambert , Caby Fabienne , Soulié Cathia , Nguyen Thi Thu-Thuy , Tubiana Roland , Kirstetter Myriam , Junot Helga , Marcelin Anne-Geneviève , Peytavin Gilles , Tilleul Patrick , Katlama Christine 
Published: May 2019

AbstractObjectivesIn a context of life-long therapy, we asked whether it could be possible to reduce the number of antiretroviral drugs without jeopardizing viral suppression.MethodsECOVIR was a prospective study aiming to assess whether in patients on combination ART with ≥4 antiretrovirals for ≥24 weeks and virally suppressed for ≥48 weeks, a drug-reduced (DR) regimen could be proposed. The intervention consisted of discontinuing genotypically less susceptible drugs to reach a DR regimen with ≤3 antiretrovirals. The primary endpoint was the proportion of patients maintaining viral suppression at week (W) 24.ResultsFrom 89 eligible individuals for the study, a DR regimen was proposed in 86 (97%) patients, of whom 71 were switched to a DR regimen. Baseline characteristics [median (IQR)] were: age 58 (53–65) years, duration of treatment 24 (21–26) years and viral suppression 8 (6–11) years. The cumulative resistance profile showed full resistance to lamivudine/emtricitabine (91%), abacavir (74%), efavirenz/nevirapine (70%), rilpivirine (56%), darunavir (q24h/q12h) (42%/29%), lopinavir (69%), atazanavir (71%) and raltegravir (24%). The final DR regimen consisted of a two-drug or three-drug regimen in 54 patients (76%) and in 17 patients (24%), respectively. The success rate of a DR regimen at W24 was 93.9% (95% CI 84.4–97.6, Kaplan–Meier estimate). Four patients experienced virological failure (at W4, W8 and W12), all with plasma viral load (pVL) <600 copies/mL and no emergence of resistance mutations. The DR strategy allowed a monthly cost saving of 36%.ConclusionsIn experienced patients with high-level resistance, individualized strategies based on expert advice can offer DR regimen options with fewer drug–drug interactions and a significant economic impact while ensuring virological success.