bluuebunny/crossref_metadata_2025 huggingface dataset:
Driver's Licenses for All? Racialized Illegality and the Implementation of Progressive Immigration Policy in California
Authors: Enriquez Laura E. , Vazquez Vera Daisy , Ramakrishnan S. Karthick
Published: January 2019

Progressive subfederal immigration policy aims to reduce the consequences of illegality for undocumented immigrants. Drawing on interviews with representatives from immigrant‐serving organizations in California, we examine the case of Assembly Bill (A.B.) 60 driver's licenses to assess whether all Californian undocumented immigrants have equal access to a driver's license. Although A.B. 60 was race‐neutral legislation, we argue that its implementation was shaped by racialized migration histories and that it reproduces racialized illegality. Specifically, the deep history of undocumented Mexican migration to California has shaped the institutional capacity of nonprofit and community organizations, foreign consulates, and the Department of Motor Vehicles to advocate for, implement, and serve A.B. 60 applicants. As a result, Spanish‐speaking, Latina/o/x immigrants, particularly those of Mexican origin, experience greater access to A.B. 60 driver's licenses. To combat this, organizations actively worked to reracialize illegality as an issue that also affects non‐Latino populations. Ultimately, we demonstrate that the construction and experience of illegality are deeply tied to race and place.
Population genomics demystifies the defoliation phenotype in the plant pathogen Verticillium dahliae
Authors: Zhang Dan‐Dan , Wang Jie , Wang Dan , Kong Zhi‐Qiang , Zhou Lei , Zhang Geng‐Yun , Gui Yue‐Jing , Li Jun‐Jiao , Huang Jin‐Qun , Wang Bao‐Li , Liu Chun , Yin Chun‐Mei , Li Rui‐Xing , Li Ting‐Gang , Wang Jin‐Long , Short Dylan P. G. , Klosterman Steven J. , Bostock Richard M. , Subbarao Krishna V. , Chen Jie‐Yin , Dai Xiao‐Feng
Published: January 2019

Verticillium dahliae is a broad host‐range pathogen that causes vascular wilts in plants. Interactions between three hosts and specific V. dahliae genotypes result in severe defoliation. The underlying mechanisms of defoliation are unresolved.

Genome resequencing, gene deletion and complementation, gene expression analysis, sequence divergence, defoliating phenotype identification, virulence analysis, and quantification of V. dahliae secondary metabolites were performed.

Population genomics previously revealed that G‐LSR2 was horizontally transferred from the fungus Fusarium oxysporum f. sp. vasinfectum to V. dahliae and is exclusively found in the genomes of defoliating (D) strains. Deletion of seven genes within G‐LSR2, designated as VdDf genes, produced the nondefoliation phenotype on cotton, olive, and okra but complementation of two genes restored the defoliation phenotype. Genes VdDf5 and VdDf6 associated with defoliation shared homology with polyketide synthases involved in secondary metabolism, whereas VdDf7 shared homology with proteins involved in the biosynthesis of N‐lauroylethanolamine (N‐acylethanolamine (NAE) 12:0), a compound that induces defoliation. NAE overbiosynthesis by D strains also appears to disrupt NAE metabolism in cotton by inducing overexpression of fatty acid amide hydrolase.

The VdDfs modulate the synthesis and overproduction of secondary metabolites, such as NAE 12:0, that cause defoliation either by altering abscisic acid sensitivity, hormone disruption, or sensitivity to the pathogen.
An 11‐country study to benchmark the implementation of recommended nutrition policies by national governments using the Healthy Food Environment Policy Index, 2015‐2018
Authors: Vandevijvere Stefanie , Barquera Simon , Caceres Gabriela , Corvalan Camila , Karupaiah Tilakavati , Kroker‐Lobos Maria Fernanda , L'Abbé Mary , Ng See Hoe , Phulkerd Sirinya , Ramirez‐Zea Manuel , Rebello Salome A. , Reyes Marcela , Sacks Gary , Sánchez Nóchez Carmen María , Sanchez Karina , Sanders David , Spires Mark , Swart Rina , Tangcharoensathien Viroj , Tay Zoey , Taylor Anna , Tolentino‐Mayo Lizbeth , Van Dam Rob , Vanderlee Lana , Watson Fiona , Whitton Clare , Swinburn Boyd
Published: January 2019

The Healthy Food Environment Policy Index (Food‐EPI) aims to assess the extent of implementation of recommended food environment policies by governments compared with international best practices and prioritize actions to fill implementation gaps. The Food‐EPI was applied in 11 countries across six regions (2015‐2018). National public health nutrition panels (n = 11‐101 experts) rated the extent of implementation of 47 policy and infrastructure support good practice indicators by their government(s) against best practices, using an evidence document verified by government officials. Experts identified and prioritized actions to address implementation gaps. The proportion of indicators at “very low if any,” “low,” “medium,” and “high” implementation, overall Food‐EPI scores, and priority action areas were compared across countries. Inter‐rater reliability was good (GwetAC2 = 0.6‐0.8). Chile had the highest proportion of policies (13%) rated at “high” implementation, while Guatemala had the highest proportion of policies (83%) rated at “very low if any” implementation. The overall Food‐EPI score was “medium” for Australia, England, Chile, and Singapore, while “very low if any” for Guatemala. Policy areas most frequently prioritized included taxes on unhealthy foods, restricting unhealthy food promotion and front‐of‐pack labelling. The Food‐EPI was found to be a robust tool and process to benchmark governments' progress to create healthy food environments.
Beyond the bone: Bone morphogenetic protein signaling in adipose tissue
Authors: Blázquez‐Medela Ana M. , Jumabay Medet , Boström Kristina I.
Published: January 2019

The bone morphogenetic proteins (BMPs) belong to the same superfamily as related to transforming growth factor β (TGFβ), growth and differentiation factors (GDFs), and activins. They were initially described as inducers of bone formation but are now known to be involved in morphogenetic activities and cell differentiation throughout the body, including the development of adipose tissue and adipogenic differentiation. BMP4 and BMP7 are the most studied BMPs in adipose tissue, with major roles in white adipogenesis and brown adipogenesis, respectively, but other BMPs such as BMP2, BMP6, and BMP8b as well as some inhibitors and modulators have been shown to also affect adipogenesis. It has become ever more important to understand adipose regulation, including the BMP pathways, in light of the strong links between obesity and metabolic and cardiovascular disease. In this review, we summarize the available information on BMP signaling in adipose tissue using preferentially articles that have appeared in the last decade, which together demonstrate the importance of BMP signaling in adipose biology.
Global Determinants of the Gold Price: A Multivariate Cointegration Analysis
Authors: Murach Michael
Published: January 2019

The present paper follows publications which have investigated the influence of global liquidity developments on commodity prices and asset price indices. It contributes to the literature by analyzing how global developments in money, output, and inflation can be related to developments in gold prices in a long‐run perspective. Applying a multivariate cointegration (CVAR) analysis, this study investigates long‐run relationships between these variables. The results suggest a significant influence of excess global liquidity on real gold prices and a co‐movement of real gold prices and global inflation.
Time–frequency relationship between US inflation and inflation uncertainty: evidence from historical data
Authors: Albulescu Claudiu Tiberiu , Tiwari Aviral Kumar , Miller Stephen M. , Gupta Rangan
Published: January 2019

We provide new evidence on the relationship between inflation and its uncertainty in the United States on an historical basis, covering the period from 1775 to 2014. First, we use a bounded approach for measuring inflation uncertainty, as proposed by Chan et al. (2013), and compare the results with the Stock and Watson (2007) and Chan (2015) methods. Second, we employ the wavelet methodology to analyze the comovements and causal effects between the two series. Our results provide evidence of a relationship between inflation and its uncertainty that varies across time and frequency. First, we show that in the medium and long runs, the Freidman–Ball hypothesis holds with a bounded measure of uncertainty, while if the Stock and Watson (2007) measure of uncertainty is used, the Cukierman–Meltzer reasoning prevails. Therefore, the findings are sensitive to the way inflation uncertainty is computed. Second, we discover mixed evidence about the inflation–uncertainty nexus in the short run, findings that explain the mixed results reported to date in the empirical literature.
Evaluating Parent Participation in Individualized Education Programs by Opinions of Parents and Teachers
Authors: İlik Ş. Şenay , Er Rukiye Konuk
Published: January 2019

All individuals who are responsible for the education of learners with special needs must actively participate in Individualized Education Programs (IEP). Moreover, IEP is a common ground encouraging educators and parents to work together on an education plan. This study aims to evaluate the opinions of both parents and teachers regarding parent participation in IEP. The qualitative approach was used in this study. To profoundly examine the opinions of parents and special education teachers and to make them explain it in their own words, descriptive survey model, one of the qualitative research methods, was used. Descriptive survey model enables to organize data according to the themes put forward by the research questions and to present it by considering questions and dimensions. The purposive sampling method was used in this study to obtain more detailed information regarding the opinions of special education teachers and parents with children with special needs about the preparation and implementation process of IEP. 22 teachers and 25 parents participated in the study. Data were analyzed through content analysis. It was found that most of the parents do not know anything about IEP. It was also found that parents are not involved in the IEP process and they are not invited by the school/institution. As for the opinions of teachers, it was found that they have some problems about getting the parents to involve in the IEP process. It was seen that teachers are lack of knowledge regarding how to include parents in the IEP process.
Stiffness Contrast and Separation Influence Wrinkling of Adjacent Layers in a Homogeneous Matrix
Authors: M. Colin Jérôme , Darayi Mohsen , Holland Maria A.
Published: January 2019

In this paper, we study the wrinkling instability of two layers embedded in a homogeneous matrix of infinite size. Using a linear stability analysis, we characterize the wrinkling of the two layers as a function of the layer spacing and the shear moduli ratio between the two materials. When the layers are stiffer than the surrounding matrix, stiffness contrast largely determines the stability behavior of the system. When the layers are softer than the surrounding matrix, stiffness contrast and layer spacing interact to determine critical threshold strain and wavelength, and result in striking discontinuities in wavelength between regimes. When the layers are close to each other, the system has a strong preference for the symmetric wrinkling mode, but as the distance between the two layers increases, the anti-symmetric mode may emerge.
Solid-solid dewetting of scandium thin films on the W(100) surface observed using emission microscopy
Authors: Mroz Michael V. , Savina Tatiana , Kordesch Martin E. , Sadowski Jerzy T. , Tenney Samuel A.
Published: January 2019

Several operating modes of cathode lens emission microscopy are used to observe scandium on W(100), including mirror microscopy, thermionic emission microscopy, and low energy electron diffraction. Scandium thin films are deposited by thermal evaporation from a metal source onto W(100). The scandium films on W(100) are observed to dewet from the W(100) surface and to form droplets when the surface is heated: the dewetting temperature is thickness dependent and spans a range from 500 to 900 °C, which is far below the melting temperature (1541 °C). Thinner films produce smaller droplets; a range of film thicknesses from 5 to 30 nm was tested. X-ray photoelectron spectroscopy of the scandium films exposed to oxygen was also measured in order to understand the function of scandium in thermionic cathodes. The shift of the W 4f peaks upon oxygen absorption, scandium adsorption, and subsequent heating indicates that oxygen preferentially bonds to scandium. The shift in the scandium 3p level indicates formation of Sc2O3.
Do plants favor their kin?
Authors: Pennisi Elizabeth
Published: January 2019

Once considered outlandish, the idea that plants help their relatives is taking root.
Asteroid mission faces ‘breathtaking’ touchdown
Authors: Normile Dennis
Published: January 2019

As first data roll in from Hayabusa2, engineers plan descent to rocky surface.
Counter-propagating charge transport in the quantum Hall effect regime
Authors: Lafont Fabien , Rosenblatt Amir , Heiblum Moty , Umansky Vladimir
Published: January 2019

A backward current

Two-dimensional materials in a magnetic field can exhibit the so-called quantum Hall effect. This regime is characterized by currents running along the edge of the sample in the “downstream” direction determined by the sign of the magnetic field. Lafont
et al.
studied electrical transport in GaAs-AlGaAs heterostructures, focusing on a previously less-studied spin-unpolarized state in the fractional quantum Hall regime. By considering various experimental configurations, they observed a component of the charge current flowing in the opposite, “upstream” direction.

Science
, this issue p.
54
A military alliance goes green
Greening the Alliance
Simone Turchetti
University of Chicago Press, 2018. 263 pp.
Authors: Degroot Dagomar
Published: January 2019

Seeking solutions to Cold War divisions, in the mid-20th century NATO embraced environmentalism
Robots, telework, and the jobs of the future
The Globotics Upheaval: Globalization, Robotics, and the Future of Work
Richard Baldwin
Oxford University Press, 2019. 300 pp.
Authors: Peha Jon
Published: January 2019

Globalization and AI are primed to disrupt tomorrow's workplace, argues an economist
Understanding Lassa fever
Authors: Bhadelia Nahid
Published: January 2019

Genomics study informs about Lassa fever epidemiology
Improving crop yield
Authors: Eisenhut Marion , Weber Andreas P. M.
Published: January 2019

Synthetic photorespiration bypass increases crop yield
Autoimmunity and immunodeficiency at the crossroad: autoimmune disorders as the presenting feature of selective IgM deficiency
Authors: Campochiaro Corrado , Atay Sirin , Clark Kristina E N , Ong Voon , Denton Christopher P
Published: January 2019

Selective immunoglobulin M deficiency (sIgMD) is an immunodeficiency with undefined pathogenesis and commonly presenting with recurrent infections.1The European Society for Immunodeficiencies Registry defines sIgMD as a serum IgM level repeatedly below 2 SD of normal with normal levels of serum IgA, IgG and IgG subclasses, normal vaccination responses, absence of T-cell defects and absence of causative external factors. Rarely it can also be associated with autoimmune diseases.2–7Here we describe a patient with primary sIgMD; who presented with multiple autoimmune diseases without a history of recurrent infections and we provide a short literature review on sIgMD and autoimmune diseases.
Pregnancy, malignancy or mother nature? Persistence of high hCG levels in a perimenopausal woman
Authors: Demir Ayşe Y , Musson Ruben EA , Schöls Willem A , Duk Jitze M
Published: January 2019

Despite the fact that a small percentage of peri en postmenopausal women have mild elevations in human chorionic gonadotrophin (hCG) concentrations (<14 IU/L) besides high levels of gonadotrophins, a considerable number of clinicians are not aware of this phenomenon. We report a case of a 53-year-old woman with an unusually high hCG concentration (>40 IU/L) given her menopausal state. Although a pregnancy or a malignancy was unlikely on the basis of stable hCG levels, elevated gonadotrophins and a negative transvaginal ultrasound, her physicians were uncertain and chose an expectant approach by repeated testing. Ultimately, after consulting the laboratory, analytical interference was ruled out and pituitary origin of unusual high hCG level could be confirmed after conduction of a suppression test by oestrogen–progesterone hormone replacement therapy. Until that time, the patient had undergone a vast amount of laboratory tests and gynaecology consultations, resulting in an enormous amount of confusion, anxiety and overdiagnosis.
Effects of screentime on the health and well-being of children and adolescents: a systematic review of reviews
Authors: Stiglic Neza , Viner Russell M
Published: January 2019

Objectives

To systematically examine the evidence of harms and benefits relating to time spent on screens for children and young people’s (CYP) health and well-being, to inform policy.

Methods

Systematic review of reviews undertaken to answer the question ‘What is the evidence for health and well-being effects of screentime in children and adolescents (CYP)?’ Electronic databases were searched for systematic reviews in February 2018. Eligible reviews reported associations between time on screens (screentime; any type) and any health/well-being outcome in CYP. Quality of reviews was assessed and strength of evidence across reviews evaluated.

Results

13 reviews were identified (1 high quality, 9 medium and 3 low quality). 6 addressed body composition; 3 diet/energy intake; 7 mental health; 4 cardiovascular risk; 4 for fitness; 3 for sleep; 1 pain; 1 asthma. We found moderately strong evidence for associations between screentime and greater obesity/adiposity and higher depressive symptoms; moderate evidence for an association between screentime and higher energy intake, less healthy diet quality and poorer quality of life. There was weak evidence for associations of screentime with behaviour problems, anxiety, hyperactivity and inattention, poorer self-esteem, poorer well-being and poorer psychosocial health, metabolic syndrome, poorer cardiorespiratory fitness, poorer cognitive development and lower educational attainments and poor sleep outcomes. There was no or insufficient evidence for an association of screentime with eating disorders or suicidal ideation, individual cardiovascular risk factors, asthma prevalence or pain. Evidence for threshold effects was weak. We found weak evidence that small amounts of daily screen use is not harmful and may have some benefits.

Conclusions

There is evidence that higher levels of screentime is associated with a variety of health harms for CYP, with evidence strongest for adiposity, unhealthy diet, depressive symptoms and quality of life. Evidence to guide policy on safe CYP screentime exposure is limited.

PROSPERO registration number

CRD42018089483.
Stromal morphological changes and immunophenotypic features of precancerous lesions and hepatocellular carcinoma
Authors: Chen Dingbao , Li Zhao , Zhu Weihua , Cheng Qian , Song Qiujing , Qian Lihua , Zhu Ji-Ye
Published: January 2019

Aims

To evaluate stromal histopathological features and immunostaining expression for differential diagnosis of low- and high-grade dysplastic nodules (HGDN) to early and progressed hepatocellular carcinomas (eHCC, pHCC).

Materials

We evaluated sinusoid capillarisation (SC), solitary artery (SA), ductular reaction (DR), stromal invasion and expression of six biomarkers (GPC3, HSP70, GS, CD34, CK19, EpCAM) in a series of 97 cases.

Results

Stromal morphological changes, including SC, DR and SA, exhibited significant differences in differential diagnosis. In one indicator, SC had the best sensitivity (90.00%) and accuracy (85.42%), and SA had the best specificity at 88.89 %. In combinations, SC +and SA +were favourable and optimal. The immunoreactivity of GPC3, HSP70 and GS increased significantly in line with the stepwise progression of hepatocarcinogenesis.

Conclusions

Stromal histopathology features are useful for diagnosing HGDN, eHCC and small HCC. The immunostaining panel of GPC3, HSP70 and GS can also be supplementary.
Corrosion fatigue properties of narrow gap laser welded 301L stainless steel
Authors: Zhang Hang , Yang Tao , Sun Kai , Hu Yingcan
Published: January 2019

In this paper, the corrosion-fatigue behavior of 301L stainless steel (SS) welded joints using narrow gap laser wire welding under the different stress ratio and concentrations of Cl[Formula: see text] has been investigated. Corrosion fatigue life curve (S-N) under different conditions was tested and fitted to obtain the fatigue limit. The microstructures and fracture surfaces of specimens were examined by optical microscopy (OM) and scanning electron microscopy (SEM). EBSD results have shown that chromium depletion in the weld heat-affected zone (HAZ) contributes to the decrease of corrosion fatigue properties in the HAZ.
Adsorption behaviors of ether and aluminum surface: A molecular dynamics study
Authors: Liu Pingan , Sun Ruochen , Liu Junpeng
Published: January 2019

As a pre-study for ether-coated aluminum (Al) nanoparticles (ANPs), ReaxFF or reactive force field-based Molecular Dynamic (MD) Simulations are performed to uncover the mechanism of adsorption behaviors between the Aluminum surface and ether molecules. Meanwhile, part of the results has been verified by experiments. In this study, three different models have been employed with varying concentrations of ether molecules. The obtained results indicate that the adsorption of the ether molecule could be divided into four stages and each stage is associated with charge transfer between Hydrogen and Aluminum atoms. After that, adsorbed ether molecules keep a horizontal state above the Aluminum surface with a vacuum. By evaluating variable temperature conditions, it is concluded that the room-temperature is suitable for forming the ether coating on Aluminum surface. Besides, a higher ether concentration could also bring beneficial effects relating to adsorbing rates. While the disassociated ether solution is removed, it seems that some adsorbed ether molecules will be desorbed, which is similar to the volatilization effect in the filtering experiment. Finally, simulations for desorption show that 455 (K) is a critical point for the adsorbed ether layer.
Measuring the research impact of the book
Folding and Fracturing of Rocks
by John G. Ramsay
Authors: Lisle Richard J. , Bastida Fernando , Aller Jesús
Published: January 2019

On the 50th anniversary of the publication of the book
Folding and Fracturing of Rocks
by John G. Ramsay we use an analysis of citations to assess the book's impact on research in the field of structural geology. Five topics dealt with in the book have had special success in terms of the number of citations: (1) superimposed folding; (2) fold classification based on layer thickness variation; (3) simple shear deformation; (4) the

R
f

/
φ
method; and (5) the flexural-slip mechanism of folding. The great impact of this book can be seen in several examples where the book has inspired new lines of research, such as: progressive deformation, strain analysis, shear zones and folding analysis. Ramsay's great merit in writing his book was to have wisely known to apply the quantitative methodology of continuum mechanics to the analysis of the geological structures. We conclude that
Folding and Fracturing of Rocks
is the most influential textbook in the field of structural geology research.
Agile Culture
Authors: Fraser Steven , Manci Dennis
Published: January 2019

The culture of agile development practices and an assessment of agile's "success" were the topics of two XP2017 panel sessions. There were three primary conclusions of these two panels. Agile has high brand recognition in the software industry, but it isn't always successfully implemented. In some cases, the labels used to explain and promote agile practices can get in the way of agile success. It was also recognized that despite a negative perception, agile's reputation as being a cult was more a reflection of a small, but growing core of practitioners.
Designing the Software Systems of the Future
Authors: Northrop Lina , Ozkaya Ipek , Fairbanks George , Keeling Michael
Published: January 2019

We report here on the Future of Software Design Workshop that was held on Jan 12-14, 2018 in Pittsburgh, PA under the sponsorship of the Carnegie Mellon University Software Engineering Institute. The software industry is awash in modern trends that involve artificial intelligence (AI), autonomy, data everywhere, etc. These trends affect the structure of softwareintensive systems and their designs. The goal of the workshop was to bring together participants from diverse backgrounds to formulate ideas for software design of future systems and related research opportunities and challenges. In this report we summarize the outcomes of the workshop
No Silver Bullet Reloaded
Authors: Fraser Steven , Manci Dennis
Published: January 2019

At XP2017 in Koln, a panel was convened to discuss the classic 1987 IEEE Software paper by Frederick P. Brooks, "No Silver Bullet: Essence and Accidents in Software Engineering." The ideas presented in his paper have influenced several generations of software developers. Brooks emphasized the notions of essential complexity and accidental complexity, and he offered suggestions for promising approaches to software development. While his approaches are linked to what we now recognize as "agile practices," panelists offered an implicit caveat that they must be done with discipline to avoid increased accidental complexity. Panelists also observed that agile development itself is not a "silver bullet".
The ALI Architecture Description Language
Authors: Haider Umaima , McGregor John D. , Bashroush Rabih
Published: January 2019

Architecture Description Languages (ADLs) have emerged over the past two decades as a means to abstract details of large-scale systems in order to enable better intellectual control over the complete systems. Recently, there has been an explosion in the number of ADLs created in the research community. However, industrial adoption of these ADLs has been rather limited. This has been attributed to various reasons, including the lack of support of some ADLs for: variability management, requirements traceability, architectural artefact reusability and multiple architectural views. To overcome these limitations, this paper is a report on ALI, an ADL that was designed to complement existing work by adding mechanisms to address the aforementioned limitations. The ALI design principles, concepts, notations and formal semantics are presented in this paper. The notation is illustrated using two distinct case studies, one from the information systems domain " an Asset Management System (AMS); and another from the embedded systems domain - a Wheel Brake System (WBS).
Agile Culture
Authors: Fraser Steven , Mancl Dennis
Published: January 2019

The culture of agile development practices and an assessment of agile's "success" were the topics of two XP2017 panel sessions. There were three primary conclusions of these two panels. Agile has high brand recognition in the software industry, but it isn't always successfully implemented. In some cases, the labels used to explain and promote agile practices can get in the way of agile success. It was also recognized that despite a negative perception, agile's reputation as being a cult was more a reflection of a small, but growing core of practitioners.
Designing the Software Systems of the Future
Authors: Northrop Linda , Ozkaya Ipek , Fairbanks George , Keeling Michael
Published: January 2019

We report here on the Future of Software DesignWorkshop that was held on Jan 12-14, 2018 in Pittsburgh, PA under the sponsorship of the Carnegie Mellon University Software Engineering Institute. The software industry is awash in modern trends that involve artificial intelligence (AI), autonomy, data everywhere, etc. These trends affect the structure of software-intensive systems and their designs. The goal of the workshop was to bring together participants from diverse backgrounds to formulate ideas for software design of future systems and related research opportunities and challenges. In this report we summarize the outcomes of the workshop.
Side-Channel Analysis via Symbolic Execution and Model Counting
Authors: Bultan Tevfik
Published: January 2019

An important problem in computer security is the detection of side-channel vulnerabilities. Information gained by observing nonfunctional properties of program executions (i.e., sidechannels such as execution time or memory usage) can enable attackers to infer secrets that the program accesses (such as a password). In this talk, I will discuss how symbolic execution, combined with a model counting constraint solver, can be used for quantifying side- channel leakage in Java programs. I will also discuss automata-based model counting techniques. We have implemented these techniques by integrating our modelcounting constraint solver, called Automata-Based model Counter (ABC), with the symbolic execution tool Symbolic Path Finder (SPF).
Test input generation using separati logic
Authors: Phan Quoc-Sang
Published: January 2019

Unit testing is the practice of testing individual units of a program, where a unit can be a method or a group of methods. Unit testing is important for software development, and automated test case generation is important for reducing the cost and improving the quality of unit testing. When an input of a un is a dynamically allocated data structure, such as list and tree, it has unbounded domain, and strict requirements over the shape or size. This makes test case generation notoriously hard. In this talk, we present Java StarFinder (JSF), a JPF extension for testing units that manipulate data structures. JSF is a symbolic execution engine that uses separation logi specification to capture the constraints over the input, and performs context-sensitive lazy initialization to construct valid test cases.
Definitional proof-irrelevance without K
Authors: Gilbert Gaëtan , Cockx Jesper , Sozeau Matthieu , Tabareau Nicolas
Published: January 2019

Definitional equality—or conversion—for a type theory with a decidable type checking is the simplest tool to prove that two objects are the same, letting the system decide just using computation. Therefore, the more things are equal by conversion, the simpler it is to use a language based on type theory. Proof-irrelevance, stating that any two proofs of the same proposition are equal, is a possible way to extend conversion to make a type theory more powerful. However, this new power comes at a price if we integrate it naively, either by making type checking undecidable or by realizing new axioms—such as uniqueness of identity proofs (UIP)—that are incompatible with other extensions, such as univalence. In this paper, taking inspiration from homotopy type theory, we propose a general way to extend a type theory with definitional proof irrelevance, in a way that keeps type checking decidable and is compatible with univalence. We provide a new criterion to decide whether a proposition can be eliminated over a type (correcting and improving the so-called singleton elimination of Coq) by using techniques coming from recent development on dependent pattern matching without UIP. We show the generality of our approach by providing implementations for both Coq and Agda, both of which are planned to be integrated in future versions of those proof assistants.
Abstracting algebraic effects
Authors: Biernacki Dariusz , Piróg Maciej , Polesiuk Piotr , Sieczkowski Filip
Published: January 2019

Proposed originally by Plotkin and Pretnar, algebraic effects and their handlers are a leading-edge approach to computational effects: exceptions, mutable state, nondeterminism, and such. Appreciated for their elegance and expressiveness, they are now progressing into mainstream functional programming languages. In this paper, we introduce and examine programming language constructs that back adoption of programming with algebraic effects on a larger scale in a modular fashion by providing mechanisms for abstraction. We propose two such mechanisms: existential effects (which hide the details of a particular effect from the user) and local effects (which guarantee that no code coming from the outside can interfere with a given effect). The main technical difficulty arises from the dynamic nature of coupling an effectful operation with the right handler during execution, but, as we show in this paper, a carefully designed type system can ensure that this will not break the abstraction. Our main contribution is a novel calculus for algebraic effects and handlers, called λ

HEL

, equipped with local and existential algebraic effects, in which the dynamic nature of handlers is kept in check by typed runtime coercions. As a proof of concept, we present an experimental programming language based on our calculus, which provides strong abstraction mechanisms via an ML-style module system.
Dynamic type inference for gradual Hindley–Milner typing
Authors: Miyazaki Yusuke , Sekiyama Taro , Igarashi Atsushi
Published: January 2019

Garcia and Cimini study a type inference problem for the ITGL, an implicitly and gradually typed language with let-polymorphism, and develop a sound and complete inference algorithm for it. Soundness and completeness mean that, if the algorithm succeeds, the input term can be translated to a well-typed term of an explicitly typed blame calculus by cast insertion and vice versa. However, in general, there are many possible translations depending on how type variables that were left undecided by static type inference are instantiated with concrete static types. Worse, the translated terms may behave differently—some evaluate to values but others raise blame.

In this paper, we propose and formalize a new blame calculus λ
B
DTI
that avoids such divergence as an intermediate language for the ITGL. A main idea is to allow a term to contain type variables (that have not been instantiated during static type inference) and defer instantiation of these type variables to run time. We introduce
dynamic type inference
(DTI) into the semantics of λ
B
DTI
so that type variables are instantiated along reduction. The DTI-based semantics not only avoids the divergence described above but also is
sound and complete
with respect to the semantics of fully instantiated terms in the following sense: if the evaluation of a term succeeds (i.e., terminates with a value) in the DTI-based semantics, then there is a fully instantiated version of the term that also succeeds in the explicitly typed blame calculus and vice versa.

Finally, we prove the gradual guarantee, which is an important correctness criterion of a gradually typed language, for the ITGL.
Less is more: multiparty session types revisited
Authors: Scalas Alceste , Yoshida Nobuko
Published: January 2019

Multiparty Session Types (MPST) are a typing discipline ensuring that a message-passing process implements a
multiparty session protocol
, without errors. In this paper, we propose a new, generalised MPST theory.

Our contribution is fourfold. (1) We demonstrate that a revision of the theoretical foundations of MPST is
necessary
: classic MPST have a limited
subject reduction
property, with inherent restrictions that are easily overlooked, and in previous work have led to flawed type safety proofs; our new theory removes such restrictions and fixes such flaws. (2) We contribute a new MPST theory that is
less
complicated, and yet
more
general, than the classic one: it does
not
require
global multiparty session types
nor
binary session type duality
— instead, it is grounded on general behavioural type-level properties, and proves type safety of many more protocols and processes. (3) We produce a detailed analysis of type-level properties, showing how, in our new theory, they allow to ensure decidability of type checking, and statically guarantee that processes enjoy, , deadlock-freedom and liveness at run-time. (4) We show how our new theory can integrate type and model checking: type-level properties can be expressed in modal µ-calculus, and verified with well-established tools.
Game semantics for quantum programming
Authors: Clairambault Pierre , De Visme Marc , Winskel Glynn
Published: January 2019

Quantum programming languages permit a hardware independent, high-level description of quantum algo rithms. In particular, the quantum lambda-calculus is a higher-order programming language with quantum primitives, mixing quantum data and classical control. Giving satisfactory denotational semantics to the quantum lambda-calculus is a challenging problem that has attracted significant interest in the past few years. Several models have been proposed but for those that address the whole quantum λ-calculus, they either do not represent the dynamics of computation, or they lack the compositionality one often expects from denotational models.

In this paper, we give the first compositional and interactive model of the full quantum lambda-calculus, based on game semantics. To achieve this we introduce a model of quantum games and strategies, combining quantum data with a representation of the dynamics of computation inspired from causal models of concurrent systems. In this model we first give a computationally adequate interpretation of the affine fragment. Then, we extend the model with a notion of symmetry, allowing us to deal with replication. In this refined setting, we interpret and prove adequacy for the full quantum lambda-calculus. We do this both from a sequential and a parallel interpretation, the latter representing faithfully the causal independence between sub-computations.
Probabilistic programming with densities in SlicStan: efficient, flexible, and deterministic
Authors: Gorinova Maria I. , Gordon Andrew D. , Sutton Charles
Published: January 2019

Stan is a probabilistic programming language that has been increasingly used for real-world scalable projects. However, to make practical inference possible, the language sacrifices some of its usability by adopting a block syntax, which lacks compositionality and flexible user-defined functions. Moreover, the semantics of the language has been mainly given in terms of intuition about implementation, and has not been formalised.

This paper provides a formal treatment of the Stan language, and introduces the probabilistic programming language SlicStan --- a compositional, self-optimising version of Stan. Our main contributions are (1) the formalisation of a core subset of Stan through an operational density-based semantics; (2) the design and semantics of the Stan-like language SlicStan, which facilities better code reuse and abstraction through its compositional syntax, more flexible functions, and information-flow type system; and (3) a formal, semantic-preserving procedure for translating SlicStan to Stan.
Formal verification of higher-order probabilistic programs: reasoning about approximation, convergence, Bayesian inference, and optimization
Authors: Sato Tetsuya , Aguirre Alejandro , Barthe Gilles , Gaboardi Marco , Garg Deepak , Hsu Justin
Published: January 2019

Probabilistic programming provides a convenient
lingua franca
for writing succinct and rigorous descriptions of probabilistic models and inference tasks. Several probabilistic programming languages, including Anglican, Church or Hakaru, derive their expressiveness from a powerful combination of continuous distributions, conditioning, and higher-order functions. Although very important for practical applications, these features raise fundamental challenges for program semantics and verification. Several recent works offer promising answers to these challenges, but their primary focus is on foundational semantics issues.

In this paper, we take a step further by developing a suite of logics, collectively named PPV for proving properties of programs written in an expressive probabilistic higher-order language with continuous sampling operations and primitives for conditioning distributions. Our logics mimic the comfortable reasoning style of informal proofs using carefully selected axiomatizations of key results from probability theory. The versatility of our logics is illustrated through the formal verification of several intricate examples from statistics, probabilistic inference, and machine learning. We further show expressiveness by giving sound embeddings of existing logics. In particular, we do this in a parametric way by showing how the semantics idea of (unary and relational) ⊤⊤-lifting can be internalized in our logics. The soundness of PPV follows by interpreting programs and assertions in quasi-Borel spaces (QBS), a recently proposed variant of Borel spaces with a good structure for interpreting higher order probabilistic programs.
Trace abstraction modulo probability
Authors: Smith Calvin , Hsu Justin , Albarghouthi Aws
Published: January 2019

We propose trace abstraction modulo probability, a proof technique for verifying high-probability accuracy guarantees of probabilistic programs. Our proofs overapproximate the set of program traces using failure automata, finite-state automata that upper bound the probability of failing to satisfy a target specification. We automate proof construction by reducing probabilistic reasoning to logical reasoning: we use program synthesis methods to select axioms for sampling instructions, and then apply Craig interpolation to prove that traces fail the target specification with only a small probability. Our method handles programs with unknown inputs, parameterized distributions, infinite state spaces, and parameterized specifications. We evaluate our technique on a range of randomized algorithms drawn from the differential privacy literature and beyond. To our knowledge, our approach is the first to automatically establish accuracy properties of these algorithms.
Inferring frame conditions with static correlation analysis
Authors: Andreescu Oana F. , Jensen Thomas , Lescuyer Stéphane , Montagu Benoît
Published: January 2019

We introduce the abstract domain of correlations to denote equality relations between parts of inputs and outputs of programs. We formalise the theory of correlations, and mechanically verify their semantic properties. We design a static inter-procedural dataflow analysis for automatically inferring correlations for programs written in a first-order language equipped with algebraic data-types and arrays. The analysis, its precision and execution cost, have been evaluated on the code and functional specification of an industrial-size micro-kernel. We exploit the inferred correlations to automatically discharge two thirds of the proof obligations related to the preservation of invariants for this micro-kernel.
Adventures in monitorability: from branching to linear time and back again
Authors: Aceto Luca , Achilleos Antonis , Francalanza Adrian , Ingólfsdóttir Anna , Lehtinen Karoliina
Published: January 2019

This paper establishes a comprehensive theory of runtime monitorability for Hennessy-Milner logic with recursion, a very expressive variant of the modal µ-calculus. It investigates the monitorability of that logic with a linear-time semantics and then compares the obtained results with ones that were previously presented in the literature for a branching-time setting. Our work establishes an expressiveness hierarchy of monitorable fragments of Hennessy-Milner logic with recursion in a linear-time setting and exactly identifies what kinds of guarantees can be given using runtime monitors for each fragment in the hierarchy. Each fragment is shown to be complete, in the sense that it can express all properties that can be monitored under the corresponding guarantees. The study is carried out using a principled approach to monitoring that connects the semantics of the logic and the operational semantics of monitors. The proposed framework supports the automatic, compositional synthesis of correct monitors from monitorable properties.
Weak-consistency specification via visibility relaxation
Authors: Emmi Michael , Enea Constantin
Published: January 2019

Effective software specifications enable modular reasoning, allowing clients to establish program properties without knowing the details of module implementations. While some modules’ operations behave atomically, others admit weaker consistencies to increase performance. Consequently, since current methodologies do not capture the guarantees provided by operations of varying non-atomic consistencies, specifications are ineffective, forfeiting the ability to establish properties of programs that invoke non-atomic operations.

In this work we develop a methodology for specifying software modules whose operations satisfy multiple distinct consistency levels. In particular, we develop a simple annotation language for specifying weakly-consistent operations via visibility relaxation, wherein annotations impose varying constraints on the visibility among operations. To integrate with modern software platforms, we identify a novel characterization of consistency called sequential happens-before consistency, which admits effective validation. Empirically, we demonstrate the efficacy of our approach by deriving and validating relaxed-visibility specifications for Java concurrent objects. Furthermore, we demonstrate an optimality of our annotation language, empirically, by establishing that even finer-grained languages do not capture stronger specifications for Java objects.
Hamsaz: replication coordination analysis and synthesis
Authors: Houshmand Farzin , Lesani Mohsen
Published: January 2019

Distributed system replication is widely used as a means of fault-tolerance and scalability. However, it provides a spectrum of consistency choices that impose a dilemma for clients between correctness, responsiveness and availability. Given a sequential object and its integrity properties, we automatically synthesize a replicated object that guarantees state integrity and convergence and avoids unnecessary coordination. Our approach is based on a novel sufficient condition for integrity and convergence called well-coordination that requires certain orders between conflicting and dependent operations. We statically analyze the given sequential object to decide its conflicting and dependent methods and use this information to avoid coordination. We present novel coordination protocols that are parametric in terms of the analysis results and provide the well-coordination requirements. We implemented a tool called Hamsaz that can automatically analyze the given object, instantiate the protocols and synthesize replicated objects. We have applied Hamsaz to a suite of use-cases and synthesized replicated objects that are significantly more responsive than the strongly consistent baseline.