bluuebunny/crossref_metadata_2025 huggingface dataset:
Activity of the PI3K-δ,γ inhibitor duvelisib in a phase 1 trial and preclinical models of T-cell lymphoma
Authors: Horwitz Steven M. , Koch Raphael , Porcu Pierluigi , Oki Yasuhiro , Moskowitz Alison , Perez Megan , Myskowski Patricia , Officer Adam , Jaffe Jacob D. , Morrow Sara N. , Allen Kerstin , Douglas Mark , Stern Howard , Sweeney Jennifer , Kelly Patrick , Kelly Virginia , Aster Jon C. , Weaver David , Foss Francine M. , Weinstock David M.
Published: December 2017

Key Points

The oral PI3K-δ,γ inhibitor duvelisib demonstrated clinical activity and a favorable safety profile in patients with CTCL and PTCL. Duvelisib induced cell-autonomous killing of TCL lines and reprogrammed PTCL-associated macrophages in vivo.
Hematopoietic stem cell gene therapy for IFNγR1 deficiency protects mice from mycobacterial infections
Authors: Hetzel Miriam , Mucci Adele , Blank Patrick , Nguyen Ariane Hai Ha , Schiller Jan , Halle Olga , Kühnel Mark-Philipp , Billig Sandra , Meineke Robert , Brand Daniel , Herder Vanessa , Baumgärtner Wolfgang , Bange Franz-Christoph , Goethe Ralph , Jonigk Danny , Förster Reinhold , Gentner Bernhard , Casanova Jean-Laurent , Bustamante Jacinta , Schambach Axel , Kalinke Ulrich , Lachmann Nico
Published: December 2017

Key Points

Hematopoietic cell and gene therapy can prevent in vivo infections by Mycobacteria spp. using different lentiviral vectors. Cellular repair of macrophages in vivo highlights phagocytes as key players in the disease progression.
Dose Dependency and a Functional Cutoff for TPO-Antibody Positivity During Pregnancy
Authors: Korevaar Tim I M , Pop Victor J , Chaker Layal , Goddijn Mariette , de Rijke Yolanda B , Bisschop Peter H , Broeren Maarten A , Jaddoe Vincent W V , Medici Marco , Visser Theo J , Steegers Eric A P , Vrijkotte Tanja G , Peeters Robin P
Published: December 2017

Objective

To investigate a dose dependency of thyroperoxidase antibody (TPOAb) concentrations in relation to thyroid function and premature delivery and define a population-based, pregnancy-specific, functional cutoff for TPOAb positivity.

Design

Individual participant meta-analysis of three prospective birth cohorts: the Amsterdam Born Children and their Development study, and the Holistic Approach to Pregnancy.

Setting

Population-based studies in the Netherlands (2002 to 2014).

Participants

A total of 11,212 pregnant women (<20 weeks’ gestation).

Main Outcome Measures

Thyrotropin (TSH) and FT4 concentrations, premature delivery.

Results

In all cohorts, there was a dose-dependent positive association of TPOAb concentrations with TSH concentrations, as well as a dose-dependent negative association with FT4 concentrations during early pregnancy (all P < 0.0001). There was a dose-dependent association of TPOAb concentrations with the risk of premature delivery, which was also modified by TSH concentrations. Women with TPOAb concentrations from the 92nd percentile upward had a higher TSH and a higher risk of a TSH >2.5 mU/L (range, 19.4% to 51.3%). Stratified analyses showed that women with TPOAb concentrations below manufacturer cutoffs already had a higher risk of premature delivery, especially when TSH concentrations were high or in the high-normal range.

Conclusions

This study demonstrated a dose-dependent relationship between TPOAbs and thyroid function as well as the risk of premature delivery. Furthermore, our results indicate that the currently used cutoffs for TPOAb positivity may be too high. Furthermore, the use of a population-based cutoff for TPOAbs may identify women with a clinically relevant extent of thyroid autoimmunity and a higher risk of premature delivery but that would not be considered TPOAb positive or eligible for treatment otherwise.
Reversibility and Further Properties of FCFS Infinite Bipartite Matching
Authors: Adan Ivo , Bušić Ana , Mairesse Jean , Weiss Gideon
Published: December 2017

The model of FCFS infinite bipartite matching was introduced in Caldentey, Kaplan and Weiss, 2009. In this model, there is a sequence of items that are chosen i.i.d. from a finite set 𝒞 and an independent sequence of items that are chosen i.i.d. from a finite set 𝒮, and a bipartite compatibility graph G between 𝒞 and 𝒮. Items of the two sequences are matched according to the compatibility graph, and the matching is FCFS, meaning that each item in the one sequence is matched to the earliest compatible unmatched item in the other sequence. In Adan and Weiss, 2012, a Markov chain associated with the matching was analyzed, a condition for stability was derived, and a product form stationary distribution was obtained. In the current paper, we present several new results that unveil the fundamental structure of the model. First, we provide a pathwise Loynes’ type construction which enables to prove the existence of a unique matching for the model defined over all the integers. Second, we prove that the model is dynamically reversible: we define an exchange transformation in which we interchange the positions of each matched pair, and show that the items in the resulting permuted sequences are again independent and i.i.d., and the matching between them is FCFS in reversed time. Third, we obtain product form stationary distributions of several new Markov chains associated with the model. As a by-product, we compute useful performance measures, for instance the link lengths between matched items.
Who Should Finance the Supply Chain? Impact of Credit Ratings on Supply Chain Decisions
Authors: Kouvelis Panos , Zhao Wenhui
Published: December 2017

Problem description: We study the impact of credit ratings on operational and financial decisions of a supply chain with a supplier and a retailer interacting via an early payment discount contract. The retailer has a single opportunity to order a product from the supplier to satisfy future uncertain demand. Both the retailer and supplier are capital constrained, and the retailer can use both short-term bank loans and trade credits for his financing needs, while the supplier can use short-term bank loans and/or the retailers early payment. We analyze for all relevant operational decisions (wholesale price, trade credit rates, bank loans, and order quantity) for capital-constrained firms. Academic/practical relevance: We add a framework on who should finance inventories, and at what rates, in the presence of differential credit ratings of the supply chain parties. Methodology: Within a modified selling to the newsvendor Stackelberg game with the supplier as the leader, we derive the equilibrium trade credit rates, wholesale price, bank loans, and order quantity. Results: We show there exists a threshold such that if the supplier’s credit rating is above it, then the supplier offers trade credits with zero interest rate and the retailer uses trade credits only. Otherwise, the supplier sets a positive rate, which motivates the retailer to combine trade credits and bank loans. The supplier always benefits from working with good rating retailers. A retailer prefers to work with suppliers outside the supplier’s credit rating hole (a finite set of ratings) over suppliers with ratings within the range. Managerial implications: We provide insights on who should finance supply chain inventories and at what rates when there are differential credit rating between the supplier and retailer. We provide a plausible explanation for the practice of large and good credit rating retailers maintaining a small cash ratio and working with small suppliers in developing countries.

The online appendix is available at https://doi.org/10.1287/msom.2017.0669 .

This paper has been accepted for the Manufacturing & Service Operations Management Special Issue on Interface of Finance, Operations, and Risk Management.
Shifting gender gaps in journalism? A longitudinal study on gender segregation in a converging media environment
Authors: De Vuyst Sara
Published: December 2017

This study explores whether recent technological changes in journalism have confirmed traditional gender segregation or created new gender divides. Our first research question focuses on the representation of male and female journalists in online and cross-media journalism that has emerged in the increasingly converged media landscape. Our second question looks at digital tools and explores whether social media are used differently by male and female journalists. In five-year intervals, we conducted a longitudinal survey (2003, 2008, 2013) in which all active journalists in the Dutch-speaking part of Belgium were invited to participate. The response rate was 45% in 2003 (1026 journalists), 31% in 2008 (682 journalists) and 33% in 2013 (751 journalists). Our findings show that women are underrepresented in online and cross-media journalism: female journalists work for fewer websites compared to male journalists and produce less content for different media sectors. The traditional forms of gender segregation were reflected in online journalism. Female journalists also used fewer microblogs, such as Twitter, to disseminate information.
How to be a choni: Tutorial videos, class and gender in Spain’s economic recession
Authors: Moreno Segarra Ignacio , Bernárdez Rodal Asunción
Published: December 2017

This article examines the construction of the choni (chavette) character through ironic and popular beauty tutorials created by Spanish vloggers and their connection with the economic recession in Spain. Our main objective is to discover the use of gender, cultural and class markers in this process and their relation to the dynamics of self-construction and self-differentiation existent on YouTube. In order to identify these characteristics, we are going to use a semiotic and Foucauldian discourse analysis based on the cultural approach to the chav phenomenon in the United Kingdom. The findings from our research illustrate how the figure of the choni is defined by the process of racialization and sexualization and by a lack of cultural competence.
Approximately counting triangles in large graph streams including edge duplicates with a fixed memory usage
Authors: Wang Pinghui , Qi Yiyan , Sun Yu , Zhang Xiangliang , Tao Jing , Guan Xiaohong
Published: December 2017

Counting triangles in a large graph is important for detecting network anomalies such as spam web pages and suspicious accounts (e.g., fraudsters and advertisers) on online social networks. However, it is challenging to compute the number of triangles in a large graph represented as a stream of edges with a low computational cost when given a limited memory. Recently, several effective sampling-based approximation methods have been developed to solve this problem. However, they assume the graph stream of interest contains no duplicate edges, which does not hold in many real-world graph streams (e.g., phone calling networks). In this paper, we observe that these methods exhibit a large estimation error or computational cost even when modified to deal with duplicate edges using deduplication techniques such as Bloom filter and hash-based sampling. To solve this challenge, we design a one-pass streaming algorithm for uniformly sampling distinct edges at a high speed. Compared to state-of-the-art algorithms, our algorithm reduces the sampling cost per edge from
O
(log
k
) (
k
is the maximum number of sampled edges determined by the available memory space) to
O
(1) without using any additional memory space. Based on sampled edges, we develop a simple yet accurate method to infer the number of triangles in the original graph stream. We conduct extensive experiments on a variety of real-world large graphs, and the results demonstrate that our method is several times more accurate and faster than state-of-the-art methods with the same memory usage.
Subgraph matching
Authors: Qiao Miao , Zhang Hao , Cheng Hong
Published: December 2017

Subgraph matching finds a set
I
of all occurrences of a pattern graph in a target graph. It has a wide range of applications while suffers an expensive computation. This efficiency issue has been studied extensively. All existing approaches, however, turn a blind eye to the
output crisis
, that is, when the system has to materialize
I
as a preprocessing/intermediate/final result or an index, the cost of the export of
I
dominates the overall cost, which could be prohibitive even for a small pattern graph.

This paper studies subgraph matching via two problems. 1) Is there an ideal compression of
I
? 2) Will the compression of
I
reversely boost the computation of
I
? For the problem 1), we propose a technique called VCBC to compress
I
to code (
I
) which serves effectively the same as
I.
For problem 2), we propose a subgraph matching computation framework CBF which computes code(
I
)instead of
I
to bring down the output cost. CBF further reduces the overall cost by reducing the intermediate results. Extensive experiments show that the compression ratio of VCBC can be up to 10
5
which also significantly lowers the output cost of CBF. Extensive experiments show the superior performance of CBF over existing approaches.
Interleaving with coroutines
Authors: Psaropoulos Georgios , Legler Thomas , May Norman , Ailamaki Anastasia
Published: December 2017

Index join performance is determined by the efficiency of the lookup operation on the involved index. Although database indexes are highly optimized to leverage processor caches, main memory accesses inevitably increase lookup runtime when the index outsizes the last-level cache; hence, index join performance drops. Still, robust index join performance becomes possible with
instruction stream interleaving
: given a group of lookups, we can hide cache misses in one lookup with instructions from other lookups by switching among their respective instruction streams upon a cache miss.

In this paper, we propose interleaving with coroutines for any type of index join. We showcase our proposal on SAP HANA by implementing binary search and CSB
+
-tree traversal for an instance of index join related to dictionary compression. Coroutine implementations not only perform similarly to prior interleaving techniques, but also resemble the original code closely, while supporting both interleaved and non-interleaved execution. Thus, we claim that coroutines make interleaving practical for use in real DBMS codebases.
Efficient structural graph clustering
Authors: Wen Dong , Qin Lu , Zhang Ying , Chang Lijun , Lin Xuemin
Published: December 2017

Graph clustering is a fundamental problem widely experienced across many industries. The structural graph clustering (SCAN) method obtains not only clusters but also hubs and outliers. However, the clustering results closely depend on two sensitive parameters, ϵ and μ, while the optimal parameter setting depends on different graph properties and various user requirements. Moreover, all existing SCAN solutions need to scan at least the whole graph, even if only a small number of vertices belong to clusters. In this paper we propose an index-based method for SCAN. Based on our index, we cluster the graph for any ϵ and μ in
O
(Σ

c
ϵℂ

|

E
C

|) time, where ℂ is the result set of all clusters and |

E
C

| is the number of edges in a specific cluster
C.
In other words, the time expended to compute structural clustering depends only on the result size, not on the size of the original graph. Our index's space complexity is bounded by
O
(
m
), where
m
is the number of edges in the graph. To handle dynamic graph updates, we propose algorithms and several optimization techniques for maintaining our index. We conduct extensive experiments to practically evaluate the performance of all our proposed algorithms on 10 real-world networks, one of which contains more than 1 billion edges. The experimental results demonstrate that our approaches significantly outperform existing solutions.
Training Methods and Considerations for Practitioners to Reduce Interlimb Asymmetries
Authors: Bishop Chris , Turner Anthony , Read Paul
Published: December 2017

INTERLIMB ASYMMETRIES HAVE BEEN A COMMON SOURCE OF INVESTIGATION IN RECENT YEARS WITH MOST STUDIES HIGHLIGHTING ITS PREVALENCE IN A RANGE OF ATHLETIC TASKS. FEW HAVE TESTED WHETHER REDUCING INTERLIMB DIFFERENCES IS REQUIRED FOR IMPROVED PHYSICAL PERFORMANCE. FURTHERMORE, THERE ARE A NUMBER OF CONSIDERATIONS THAT MAY EXIST, WHICH PRACTITIONERS SHOULD CONSIDER BEFORE STARTING TRAINING INTERVENTIONS TO REDUCE THESE DIFFERENCES. THIS ARTICLE WILL DISCUSS THE AVAILABLE BODY OF LITERATURE PERTAINING TO THE REDUCTION OF INTERLIMB ASYMMETRIES TO DATE AND PROVIDE EXAMPLES OF TRAINING PROGRAMS TO SHOW HOW THEY CAN BE ADDRESSED IF THEIR REDUCTION IS DEEMED NECESSARY.
Bearing Steel Technologies: 11th Volume, Advances in Steel Technologies for Rolling Bearings
Authors: Beswick John M.
Published: December 2017

Description

Get 28 peer-reviewed papers on the latest advancements in rolling bearing steel technologies.

This book features extensive research from the world’s leading bearing steel technology practitioners, including steelmakers, semi-finished and finished bearing steel component producers, rolling bearing producers, development institutes, and academics.

Topics include

These papers were presented at a November 2016 symposium sponsored by ASTM International Committee A01 on Steel, Stainless Steel, and Related Alloys.
In-Depth Comparison of Powder and Ingot Metallurgical M50 Bearing Steels
Authors: Guetard Gael , André Johanna , Bellus Jacques , Sherif Mohamed Y. , Rivera-Díaz-del-Castillo Pedro
Published: December 2017

Powder metallurgy (PM) for bearing steel manufacturing was introduced several decades ago and mainly aimed at limiting segregation effects in high-alloy grades. Despite the significant potential of this relatively new process for producing high-performance bearing steels, its use in commercial applications is still very limited today. It is thought that the slow acceptance of this promising technology is partially due to a lack of understanding of how modern PM steels compare to conventional ingot metallurgical steels. Most of the comparative studies published on this topic have only focused on a few key mechanical properties, which are rarely related to the microstructure. For this study, several variants of M50 were produced using ingot metallurgical and PM processes. This grade was chosen as its performance is well known to be limited by segregation, and it could therefore benefit from a PM process route. The evolution of the microstructure during manufacturing, from solidification to tempering, was carefully investigated. After heat treatment, toughness, hardness, and rolling contact fatigue (RCF) life were measured. RCF tests were performed using a ball-on-rod configuration to compare the performance of the alloys as well as to evaluate the microstructural changes during testing. Differences in the populations of stress raisers (primary carbides and nonmetallic inclusions) were also assessed and used to explain the variations in RCF fatigue lives.
Bearing Steel Quality Assurance with Next Generation SEM-EDS
Authors: Ricker Brock , Patel Vishal , van Beek Cornelis
Published: December 2017

Microscopic cleanliness has dominated bearing steel metallurgical quality requirements for a long time—from the 1974 ASTM symposium on the rating of nonmetallic inclusions in bearing steels to the present day. Steelmaking processes have been improved over the years; the micro-cleanliness demands have increased but the methodologies, based on light optical microscopy, have evolved very little. The goal of removing the subjectivity in micro-inclusion ratings by optical image analysis has existed for a long time, but the pixel size and time have been a limitation in light optical systems. The use of electron microscopy and energy dispersive spectroscopy showed promise in the 1970s, and improved scanning electron microscope (SEM) stability, energy dispersive spectroscopy (EDS) throughput, and EDS resolution has enabled a new generation of SEM-EDS systems. The current generation of SEM-EDS system are now used to perform composition specific micro-inclusion characterization as used in quality assurance and process improvements. In this paper, the Thermo Fisher Scientific system—as applied to bearing steel quality assurance—will be described with examples highlighting the benefits and potential caveats and workarounds.
Nonmetallic Inclusion Bonding in Bearing Steel and the Initiation of White-Etching Cracks
Authors: Vegter Erik , Krock Hans , Kadin Yuri , Ocelík Václav
Published: December 2017

The presence of nonmetallic inclusions in bearing steel is well described as well as the occurrence of white-etching cracks starting at the inclusions. In this paper, the role of interfacial strength in the initiation of small cracks at nonmetallic inclusion-steel interfaces that lead to white-etching crack systems is discussed. The effect of rolling contact fatigue on the steel-inclusion interface will be described to explain the early crack initiation, with a focus on manganese sulfide and complex aluminum oxide inclusions. The factors of size and shape both play an important role in the behavior of inclusions, as well as that of interfacial bonding, which will be shown to be decisive in the strength of a bearing steel. Experimental methods to determine inclusion-steel interface properties are applied, such as advanced tensile tests combined with digital image correlation, in order to show the level of bonding of nonmetallic inclusions. The experimental results contribute to the verification of inclusion modeling in rolling contact fatigue simulations.
Round-Robin Test: Chemical Analysis Capability of the Steel Material Laboratories
Authors: Rubart Marcel Sebastiaan , Schlueter Andreas , Holtz Thorsten
Published: December 2017

In 2014, Siemens AG initiated round-robin testing with regard to the chemical analysis capability of the steel composition from different steel plants, bearing suppliers, and external laboratories. In total, Siemens has gathered results from more than 20 labs and evaluated/analyzed more than 10 main steel elements using the following approach: 1) Definition and verification of samples: Reference values are based on an analysis certificate of the sample material by the German Federal Institute for Materials Research and Testing, with the part-to-part standard deviation calculated using the analysis of variance method. 2) Gathering of results: Measurements per element of the reference samples have been provided to Siemens AG by laboratories and steel suppliers. The result is the ratio of the standard deviation of the measured values, as an indicator of the capability of the measurement process, and the Siemens tolerance range.
Advantages of Si Deoxidation of Bearing Steels for Steel Cleanness and for Composition and Morphology of Nonmetallic Inclusions in Rolled Product
Authors: Ladutkin Dmitrij , Korte Elizabeta , Bleymehl Mark , Bruch Christian , Doppler Karl-Georg
Published: December 2017

The conventional production of bearing steel requires aluminum deoxidation with regard to lowest contents of oxygen improving the rolling contact fatigue life to a very high level. However, for more than 20 years, Saarstahl AG has used the advantages of silicon deoxidation’s ability to avoid the formation of pure high melting alumina inclusions to fulfill the stringent requirements of premium quality for the bearing and the automotive industries. Silicon deoxidized heats have an excellent castability during billet and bloom casting due to the absence of clogging. Saarstahl’s steel production is characterized by the use of alloys with very low contents of aluminum and titanium as well as slag formers without any harmful components. Due to very strict ladle metallurgy, the oxygen content in the finished product is in the range of 4 ppm to 8 ppm. The result is an excellent cleanness of the finished product with regard to ultrasonic immersion tank testing and microscopic evaluation according to ASTM E45, Standard Test Methods for Determining the Inclusion Content of Steel, that easily meets the requirements of the ball bearing industry. In the rolled material, harmless low melting inclusions with similar hardness to the steel matrix were observed. Both stringer (C-type) and intercepted (B-type) inclusions were analyzed having the same composition and mineralogical phases. With an increasing reduction ratio, a transition from stringers to intercepted inclusions occurs without changing the chemical composition of these inclusions. Using selective treatment methods in the secondary metallurgy, a very low level of low melting inclusions was achieved in the rolled product.
Influence of Si and Prior Heat Treatment on Long-Term Thermal Stability of 100Cr6-Type Bearing Steels
Authors: Sourmail Thomas , Moudian Fatima , Billet Mathieu , Millot-Méheux Mathilde
Published: December 2017

The evolution of retained austenite content during austempering or quenching and tempering is investigated for three high carbon steels. These materials were chosen for their increasing silicon content (100Cr6, 0.25 wt%; 100CrMnSi6-4, 0.6 wt%; and 100CrSiMn6-5-4, 1.2 wt%; with the latter being a proprietary alloy also referred to as Endurasco SC). The influence of tempering temperature on retained austenite content is first discussed for “conventional” tempering of steel blanks. Dilatometry is then used to investigate retained austenite evolution during tempering and, in particular, to compare it to that observed during austempering. The role of Si content is underlined and a new heat treatment schedule is proposed, which leads to the stabilization of austenite content for aging treatments of 1,000 h at 250°C.
Application of the OES-PDA Measurements to Predict the Macro-Cleanliness of Products Coming from Continuous Casting Machine
Authors: Krebs Benoit , Brun Nadege , Spadaccini Andrea , Gremeaux Gilles
Published: December 2017

Macro-cleanliness of steel is one of the major issues for both bearing makers and steelmakers starting from continuous casting machines or ingots; 10 MHz inspections are familiar for the most demanding bearing makers and can be considered as a reference technique that gives very reliable information on the macro-cleanliness. In industrial conditions, bars are controlled in-line (4 MHz or phased array), and a representative volume is checked in 10 MHz off-line (laboratory). The required time to get the final results can be long. Optical emission spectroscopy (OES) with pulse discrimination analysis (PDA) is one the fastest methods to quickly estimate the cleanliness using samples taken during the manufacturing process. OES-PDA is a well-known technique that has been applied for years to traditionally characterize micro-cleanliness and to evaluate an inclusion’s chemical composition. In this work, the cleanliness was quantified by measurements on samples taken from the tundish during the casting. Thanks to an appropriate mapping, the macro-cleanliness has been also followed on the rolled products coming from the selected heats. By comparing measurements in precise conditions, relatively good correlations have been found between some OES-PDA indexes and the macro-cleanliness index obtained applying the Stahl-Eisen-Prüfblätter standard, SEP 1927.
Improved Fatigue Life Analysis of Pre-Dented Raceways Used in Bearing Material Testing
Authors: Gabelli Antonio , Morales-Espejel Guillermo E.
Published: December 2017

Endurance testing of bearing samples with pre-dented raceways is a testing methodology often used in bearing material development. The main advantage of this type of test is the drastic reduction of the time required to carry out the measurement of bearing life. This method provides direct experimental data on the fatigue properties of the raceway material that are needed in case the fatigue strength of the raceway is enhanced using specific heat treatments or other means. An in-depth tribological fatigue analysis is applied to pre-dented bearings to get a better inside view of the damaging mechanisms taking place at the stress risers of the raceway. The analysis of the dent spalling process includes the onset and the progression of the fatigue damage originating from the dent. A novel rolling contact fatigue model, with the ability to separate the survival probability of the raceway surface from the subsurface region of the rolling contact, is applied. Results are presented showing a good ability to reproduce the observed endurance test data under a variety of testing conditions. The new model is used to study the effect of dent size, load, and lubrication of pre-dented bearings. It is found that the separation of the surface fatigue from the subsurface material degradation offers new capabilities for the tribological modeling of surface rolling contact fatigue and that this improves the correlation with the experimental observations. Examples of the application of the new method for accounting rolling contact fatigue of pre-dented bearings are given, showing the ability to describe the strengthening mechanisms observed with different bearing materials and heat treatments.
Steel Quality Improvements with Vertical Continuous Casting at Faircrest Steel Plant
Authors: Eastman Christopher M. , Glaws Peter C.
Published: December 2017

The life of a steel bearing component can be strongly influenced by the quality of the bulk material. The shape, surface, and internal structure of the component can be affected by the upstream steelmaking processes. The steel material must positively affect these characteristics through resistance to distortion and superior surface quality and internal cleanness. The TimkenSteel Faircrest jumbo bloom vertical continuous caster was designed to meet these high standards for the production of high-quality bearing steels. Improved segregation symmetry through the implementation of dynamic mechanical soft reduction and controlled cooling has resulted in customer testing to similar levels of finished product distortion as the bottom poured ingot product. The vertical nature of the machine avoids any bending or unbending strains and stresses that are placed on the surface of the curved cast product, and uniform heat extraction is more easily achieved. The straight shape of the strand also provides a greater potential for inclusion removal by flotation without producing any localized inclusion distribution such as an increased inner radius concentration often found in a curved machine cast product. Significant resources were dedicated to developing a unique and robust tundish design through physical and computational modeling efforts. The tundish produces consistent quality characteristics across all three strands and manages steady-state and transitional operational practices while incorporating a sealed inert tundish atmosphere to minimize reoxidation for increased levels of cleanness. The customized features of the machine have led to rapid qualifications from demanding bearing and gear customers using various testing methods, and quality levels have met or exceeded the TimkenSteel quality expectations.
Subsurface Rolling Contact Fatigue of Powder Metallurgy Steels for Aerospace Bearings
Authors: Sidoroff Christine , Lefort Elodie , Dierickx Pierre , André Johanna , Benbahmed Atman
Published: December 2017

For tomorrow’s mechanical systems—for example, in aerospace engines—bearings must meet more and more demanding requirements, such as weight savings and increased reliability. For these reasons, bearing materials must have an increased load capacity that today’s conventional metallurgy can only answer with dedicated lengthy and expensive heat treatment or a technological breakthrough. As powder metallurgy (PM) enables the realization of steel grades not obtainable by conventional metallurgy (high alloy and carbide contents, a very fine microstructure with low segregation, and above all a high hardness), and because technological improvements realized in recent years make this technology suitable for high reliability bearings, PM steel grades can be an answer to these more and more demanding requirements. ASP®2055 grade steel, with a hardened Rockwell hardness of 68HRC, was selected because of its good hardness/toughness compromise. Even though the inclusion cleanliness evaluations show that this PM steel is still not as clean as vacuum induction melted-vacuum arc remelted (known as VIM-VAR) and the best quality electric arc furnace-melted steels, the fatigue behavior rolling contact fatigue tests at 4.2 GPa yielded results with life durations similar to VIM-VAR steels. The reasons why it performed so well under elastohydrodynamic conditions, despite a limited cleanliness, were linked to both the high intrinsic microyield stress of the matrix and the presence of mixed oxide inclusions, leading to limited stress concentrations. These results were very promising for the use of PM ASP®2055 in high reliability bearings.
The Study of the Evaluation of the Fracture Initiation and Propagation on the Rolling Contact Fatigue in Bearing Steels
Authors: Owaki Akihiro , Shimamoto Masaki , Sugimura Tomoko , Iwasaki Katsuhiro
Published: December 2017

The bearings used in various industrial machines need to have good rolling contact fatigue resistance. It is known that the fatigue resistance in clean lubricating oil is decreased when there is a nonmetallic inclusion in the bearing steel. For this reason, various studies to reduce the size and quantity of inclusions have been carried out. On the other hand, to obtain a new approach to suppress the influence of the nonmetallic inclusions, it is important to understand the influence of each nonmetallic inclusion type on the rolling contact fatigue resistance. Therefore, we have worked on evaluations of the fracture initiation and propagation on the rolling contact fatigue in bearing steels. In the previous symposium, we reported that we had created an oxide type inclusion controlled steel (OTICS) using the melting furnace in our laboratory. This steel has an excellent rolling contact fatigue life. In this paper, we will report fracture initiation and propagation on the rolling contact fatigue in OTICS and conventional steel evaluated using an ultrasonic test and an acoustic emission test. We have investigated the defects under the rolling contact surface by the ultrasonic test, with loadings applied at certain times in the thrust-type rolling contact fatigue test. During the test, we also measured the acoustic emissions generated when a fracture occurred. From the ultrasonic test, we succeeded in detecting nonmetallic inclusions with the fractures. Furthermore, the time before defects were detected in the OTICS was longer compared to conventional steel. The same tendency was observed in the acoustic emission test. Longer load times were required before acoustic emissions were detected in OTICS. According to these results, it can be considered that OTICS has a greater rolling contact fatigue life than conventional steel due to the inhibition of the fracture initiation from the nonmetallic inclusion.
Dissecting the Roles of the Calcineurin Pathway in Unisexual Reproduction, Stress Responses, and Virulence in Cryptococcus deneoformans
Authors: Fu Ci , Donadio Nicholas , Cardenas Maria E , Heitman Joseph
Published: December 2017

The Ca2+/calmodulin-dependent protein phosphatase calcineurin orchestrates sexual reproduction, stress responses, and virulence via branched downstream pathways in the opportunistic human fungal pathogen Cryptococcus neoformans. The calcineurin-binding protein Cbp1, the calcineurin temperature suppressor Cts1, the calcineurin-responsive zinc finger transcription factor Crz1, and the calcineurin targets Pbp1, Tif3, and Puf4, all function downstream of calcineurin to orchestrate distinct cellular processes. To elucidate how the calcineurin pathway regulatory network governs unisexual reproduction, stress responses, and virulence, we have analyzed the self-filamentous C. deneoformans strain, XL280α, and generated double mutants of these calcineurin downstream genes. We demonstrated that calcineurin governs unisexual reproduction at different sexual developmental stages, in which the initiation of the yeast–hyphal morphological transition is independent of Crz1, whereas the sporulation process is dependent on Crz1. Calcineurin-dependent unisexual reproduction is independent of the pheromone response pathway. Crz1 synergistically interacts with different calcineurin downstream targets in responding to ER, high-calcium, and cell wall stresses. We observed a widespread synergy suggesting that these proteins function in complex branched pathways downstream of calcineurin with some functional redundancy, which may allow efficient signaling network rewiring within the pathway for prompt adaptation to changing environments. Finally, we showed that deletion of PBP1 or TIF3 in the cna1∆ mutant background conferred a modest level of growth tolerance at 37°, but that the cna1∆ pbp1∆ and cna1∆ tif3∆ double mutants were both avirulent, suggesting that calcineurin may control virulence via mechanisms beyond thermotolerance.
Role of Organizational Devices in ESL Readers' Construction of Mental Representations of Hypertext Content
Authors: Al-Seghayer Khalid
Published: December 2017

The current electronic text format is inherent to the problem of text integration, or, alternatively, cohesion deficit, which greatly affects reading comprehension. The question remains as to whether well structured hypertext would enable L2 readers, particularly ESL readers, to overcome potential difficulties in integrating information and building a unified representation of text content delivered by computer. This study examines the efficacy of embedding microstructural devices (e.g., headings, reviews, and logical connectives statements) and macrostructural devices (a graphical overview map of text content) on the construction and organization of computer hypertext presentations. The study also investigates the interaction between the effect of L2 readers' reading proficiency and the degree of structure in hypertext (structured vs. less structured) on ESL learners' development of coherent mental representations of hypertext content. The participants, 40 ESL students, were introduced to two hypertext reading programs. The first was considered well structured hypertext because it included organizational devices and explicitly showed its underlying hypertext structure. The second was considered less structured because it included no organizational devices and did not indicate the underlying structure of its hypertext. A repeated measures design was used in this study. Forty participants were measured under two conditions: well structured and less structured hypertexts. They were identified as intermediate ESL learners based on their TOEFL scores and were classified as proficient or less proficient readers based on their scores on the reading section of the TOEFL. To assess the efficacy of each type of hypertext, multiple choice and mapping main ideas and details tests were developed and administered to participants after they had read both hypertexts. Results of both tests were analyzed using a paired-samples t-test to compare performance in the two hypertext reading programs and a two-way (proficiency level by hypertext reading program) mixed model ANOVA. The investigation yielded findings showing that well structured hypertext aided ESL readers in developing a more coherent mental representation of the hypertext content, thereby increasing their reading comprehension. The results also indicated that well structured hypertext was more helpful to less proficient readers than it was to more proficient readers. These results offer theoretical, pedagogical, and technological implications for L2 reading instructors and instructional designers.
Tale of Two Communities
Authors: Darhower Mark
Published: December 2017

This study provides a theory-driven account of community building in a bilingual telecollaborative chat setting. A symmetrical arrangement of 70 L1 English learners of Spanish and L1 Spanish learners of English engaged in weekly Internet chat sessions in small groups. The learning metaphors of community and participation serve as the theoretical framework to describe linguistic and social behaviors and interpersonal relationships among participants in two ongoing chat groups, while, at the same time, discourse data are used to build upon theory of (virtual) community. Based on Brown's (2001) classification of levels of online community, the findings illustrate the discursive construction of one community that reached the third, cooperation/camaraderie, level and another that struggled to maintain the second, membership, level.
Can PowerPoint Presentations Effectively Replace Textbooks and Blackboards for Teaching Grammar? Do Students Find Them an Effective Learning Tool?
Authors: Corbeil Giselle
Published: December 2017

The use of PowerPoint presentations for explicit instruction of grammatical structures is increasingly encouraged at the university level. Some teachers are still reluctant to use this technology because they are not convinced that more benefits can be derived from their use than from the conventional use of textbook and blackboard. On the other hand, students who have grown up with the technology welcome this change and feel that they are learning better this way than by conventional means. This study represents an attempt at comparing these two teaching tools. Four intact classes participated in the study. The grammatical form selected was the agreement and placement of modifying adjectives. Results show that there are no significant differences from pre- to posttest on written production exercises or on essay writing and, therefore, that PowerPoint presentations are as effective as the use of a textbook plus blackboard. However, students' answers to the questionnaire indicate their preference for the PowerPoint presentations as a more effective learning tool than the textbook. Explanations are given, followed by suggestions for further research.
Retrofitted Materials for WebCT
Authors: Houston Tony
Published: December 2017

With the advent of web-based programs that automate the scoring of exercises, materials are now being developed from the outset with the capabilities of the web in mind. Materials developed without consideration of the web's capabilities, on the other hand, must be retrofitted. Texts that are retrofitted to the web have the advantage of being pedagogically, not technologically, driven. With adequate attention paid to the pedagogy of adapting such texts to the web, these texts can compete on their own merits with products that are designed from the outset for use on the web. This paper discusses some of the complications of working with retrofitted materials and presents some solutions to common problems.
Developing a Multimedia, Computer-based Spanish Placement Test
Authors: Zabaleta Francisco
Published: December 2017

Placing students of a foreign language within a basic language program constitutes an ongoing problem, particularly for large university departments when they have many incoming freshmen and transfer students. This article outlines the author's experience designing and piloting a language placement test for a university level Spanish program. The paper offers rationale for the project as well as step-by-step instructions and commentary on how to build such a test. The aim of the project was twofold. First, the design and implementation of the test was meant to address a need of a large Spanish language program by offering a fast, reliable, and easy-to-administer Spanish placement test. Second, the use of multimedia-based test items was intended to improve and facilitate comprehensible input by test takers. Analysis of the data indicates that multimedia-based items show marginal improvement in item facility (IF) coefficients over text-only items.
Shear wave velocity in sand: effect of grain shape
Authors: Liu X. , Yang J.
Published: December 2017

Whether the shear wave velocity in sand is dependent on grain shape is a basic question of considerable interest, yet remains open owing to the lack of solid experimental evidence. This technical note presents results from an experimental study where the effect of grain shape was carefully isolated from other factors and the grain shape was accurately measured using laser scanning technology. It is shown that, under otherwise similar conditions, shear wave velocity or the associated small-strain stiffness tends to decrease as sand grains become rounded, and that a fairly good correlation exists between stiffness parameters and a shape index known as overall regularity that accounts for grain shape in a collective manner. The study suggests that the laboratory finding reported in the literature, that a decrease in roundness of sand grains leads to a decrease in shear wave velocity or stiffness, was most likely attributable to varying gradation of tested materials rather than to varying grain shape.
Chile: mitos y realidades de una transición
Authors: Velasco Juan Jacobo
Published: December 2017

En Chile las instituciones funcionan, existe una estructura relativamente transparente y complementaria entre los sectores privado y público que deriva en una economía sana y responsablemente manejada, la corrupción es mínima, y el Gobierno tiene un respaldo sólo comparable con el de los países del primer mundo. En ese marco se hace ciencia social, y de la buena. En este trabajo se intenta responder a la pregunta ¿es este país una “isla de la fantasía”, forjada a sangre y fuego por diecisiete años de dictadura y un modelo económico exitoso?, o ¿es el estilo de vida del chileno una versión latinoamericana del american way of life?
Protocol for: The DHA (Docosahexaenoic acid) Oxford Learning And Behaviour (DOLAB) II Study v1
Authors: Montgomery Paul , Richardson Alex , Burton Jennifer , Burton Alice , F. Spreckelsen Thees
Published: December 2017

PROTOCOL SUMMARY Title: The DHA(docosahexaenoic acid) Oxford Learning and Behaviour (DOLAB) II Study. Type of Study: The study is a randomized, placebo controlled trial (RCT), double blind, fixed dose, parallel groups. Population: Four hundred children from academic year groups 3, 4 and 5 (who are generally aged 7 to 9 years) attending mainstream schools who are currently underperforming in reading (lowest quintile on nationally standardized achievement tests). Number of Sites: Up to two hundred schools from up to eight local authorities as required. Intervention: The active compound (DHA Omega-3), 600mg per day) and corn/soy placebo (matching in package, taste and appearance) will be administered in an oral supplement. Study Duration and process: The parents/guardians of children who are underperforming in reading (according to national tests or school records) will be invited to consent to their child participating in a short school-based session, involving brief assessments of reading and working memory, an optional pinprick blood sample, and behaviour ratings from their teachers and parents. Our previous study (DOLAB) indicated that we should anticipate that 1300 children will need to be screened at the Local Authority stage. Of those approximately half are likely to consent to participate in these brief assessments at school. Those children whose parents consent, and whose reading assessment scores place them in the lowest quintile (on a standardized reading test), will be invited to join the study provided they meet the other inclusion/exclusion criteria (n = 400). Baseline measures will be collected after which children will be randomly allocated to DHA Omega-3 or placebo conditions and followed up after 16 weeks. Recruitment will be carried out over two years. Research Questions: Primary: - Can supplementation with DHA Omega-3 improve child behaviour and learning in underperforming children in year groups 3, 4 and 5 (who are generally aged 7-9 years)? Outcomes assessed will include reading performance, working memory and ADHD-type symptoms (inattention, hyperactivity, impulsivity) as rated by parents. Secondary: - Can supplementation with DHA Omega-3 improve child ADHD-type symptoms (inattention, hyperactivity, impulsivity) as rated by teachers? - Do children’s levels of DHA Omega-3 or related fatty acids (assessed objectively via a pinprick blood sample) predict their learning or behaviour? - Are any observed changes in behaviour or cognitive performance associated with changes in blood fatty acid status?