bluuebunny/crossref_metadata_2025_split huggingface dataset:
Formal verification of a constant-time preserving C compiler
Authors: Barthe Gilles , Blazy Sandrine , Grégoire Benjamin , Hutin Rémi , Laporte Vincent , Pichardie David , Trieu Alix 
Published: December 2019

Timing side-channels are arguably one of the main sources of vulnerabilities in cryptographic implementations. One effective mitigation against timing side-channels is to write programs that do not perform secret-dependent branches and memory accesses. This mitigation, known as "cryptographic constant-time", is adopted by several popular cryptographic libraries.
This paper focuses on compilation of cryptographic constant-time programs, and more specifically on the following question: is the code generated by a realistic compiler for a constant-time source program itself provably constant-time? Surprisingly, we answer the question positively for a mildly modified version of the CompCert compiler, a formally verified and moderately optimizing compiler for C. Concretely, we modify the CompCert compiler to eliminate sources of potential leakage. Then, we instrument the operational semantics of CompCert intermediate languages so as to be able to capture cryptographic constant-time. Finally, we prove that the modified CompCert compiler preserves constant-time. Our mechanization maximizes reuse of the CompCert correctness proof, through the use of new proof techniques for proving preservation of constant-time. These techniques achieve complementary trade-offs between generality and tractability of proof effort, and are of independent interest.
CompCertM: CompCert with C-assembly linking and lightweight modular verification
Authors: Song Youngju , Cho Minki , Kim Dongjoo , Kim Yonghyun , Kang Jeehoon , Hur Chung-Kil 
Published: December 2019

Supporting multi-language linking such as linking C and handwritten assembly modules in the verified compiler CompCert requires a more compositional verification technique than that used in CompCert just supporting separate compilation. The two extensions, CompCertX and Compositional CompCert, supporting multi-language linking take different approaches. The former simplifies the problem by imposing restrictions that the source modules should have no mutual dependence and be verified against certain well-behaved specifications. On the other hand, the latter develops a new verification technique that directly solves the problem but at the expense of significantly increasing the verification cost.
In this paper, we develop a novel lightweight verification technique, called RUSC (Refinement Under Self-related Contexts), and demonstrate how RUSC can solve the problem without any restrictions but still with low verification overhead. For this, we develop CompCertM, a full extension of the latest version of CompCert supporting multi-language linking. Moreover, we demonstrate the power of RUSC as a program verification technique by modularly verifying interesting programs consisting of C and handwritten assembly against their mathematical specifications.
Label-dependent session types
Authors: Thiemann Peter , Vasconcelos Vasco T. 
Published: December 2019

Session types have emerged as a typing discipline for communication protocols. Existing calculi with session types come equipped with many different primitives that combine communication with the introduction or elimination of the transmitted value.
We present a foundational session type calculus with a lightweight operational semantics. It fully decouples communication from the introduction and elimination of data and thus features a single communication reduction, which acts as a rendezvous between senders and receivers. We achieve this decoupling by introducing label-dependent session types, a minimalist value-dependent session type system with subtyping. The system is sufficiently powerful to simulate existing functional session type systems. Compared to such systems, label-dependent session types place fewer restrictions on the code. We further introduce primitive recursion over natural numbers at the type level, thus allowing to describe protocols whose behaviour depends on numbers exchanged in messages. An algorithmic type checking system is introduced and proved equivalent to its declarative counterpart. The new calculus showcases a novel lightweight integration of dependent types and linear typing, with has uses beyond session type systems.
False News On Social Media
Authors: Pierri Francesco , Ceri Stefano 
Published: December 2019

In the past few years, the research community has dedicated growing interest to the issue of false news circulating on social networks. The widespread attention on detecting and characterizing deceptive information has been motivated by considerable political and social backlashes in the real world. As a matter of fact, social media platforms exhibit peculiar characteristics, with respect to traditional news outlets, which have been particularly favorable to the proliferation of false news. They also present unique challenges for all kind of potential interventions on the subject.
As this issue becomes of global concern, it is also gaining more attention in academia. The aim of this survey is to offer a comprehensive study on the recent advances in terms of detection, characterization and mitigation of false news that propagate on social media, as well as the challenges and the open questions that await future research on the field. We use a data-driven approach, focusing on a classification of the features that are used in each study to characterize false information and on the datasets used for instructing classification methods. At the end of the survey, we highlight emerging approaches that look most promising for addressing false news.
Synthesis and Application in Anticounterfeiting of RGB Upconversion Nanoparticles
Authors: Zhang Yongling , Lv Peng , Qin Zhengkun 
Published: December 2019

In this paper, we synthesized ~105±15 nm cubic phase KMnF3:Yb3+,Er3+ NPs, ~195±10 nm hexagonal phase NaYF4:Yb3+,Tm3+ NPs, and ~200±10 nm hexagonal phase NaYF4:Yb3+,Er3+ NPs. Under the excitation of 980 nm, the strong red upconversion luminescence (4F9/2⟶4I15/2, the peak is located at ~653 nm) of Er3+ ions of KMnF3:Yb3+,Er3+ NPs can be seen, the strong blue upconversion luminescence (1D2⟶3F4, 1G4⟶3H6; the peaks are located at ~451 nm and ~477 nm, respectively) of Tm3+ ions of NaYF4:Yb3+,Tm3+ NPs can be observed, and the strong green upconversion luminescence (4I11/2⟶4I15/2, 4S3/2⟶4I15/2; the peaks are located at ~524 nm and ~541 nm, respectively) of Er3+ ions of NaYF4:Yb3+,Er3+ NPs can be found. The mixed white upconversion luminescent materials can be obtained by adjusting the doping ratio of the above NPs. Cyclohexane solution of red, blue, green, and the mixed white NPs can be used as ink, and “JLNU” is written on paper with a pen. Without 980 nm radiation, nothing could be seen. Under 980 nm irradiation, the colored letters “JLNU” can be seen. Red, blue, green, and the mixed white upconversion NPs can be used in security anticounterfeiting.
Impact of Endothelial Shear Stress on the Bilateral Progression of Unilateral Moyamoya Disease
Authors: Lee Woo-Jin , Jeong Seul-Ki , Han Kap-Soo , Lee Sang Hyuk , Ryu Young Jin , Sohn Chul-Ho , Jung Keun-Hwa 
Published: December 2019

Background and Purpose—
In unilateral moyamoya disease, altered endothelial shear stress on the intact-side terminal internal carotid artery might trigger the progression to bilateral disease. We analyzed the endothelial shear stress parameters of the normally appearing terminal internal carotid artery in unilateral moyamoya disease and its association with the progression to bilateral disease.

Methods—
This retrospective cohort study included patients diagnosed with unilateral moyamoya disease by cerebral angiography and followed-up with regular magnetic resonance imaging/magnetic resonance angiography evaluations for >1 year. Endothelial shear stress parameters acquired were mean and maximum signal intensity gradients (SIG) and SIG SD at the vessel boundary in time-of-flight sequences in initial brain magnetic resonance imaging/magnetic resonance angiography. Contralateral disease progression defined as the detection of newly developed vessel steno-occlusion with an magnetic resonance angiography steno-occlusive stage of ≥2, in the previously intact side of the brain on follow-up magnetic resonance imaging/magnetic resonance angiography evaluation.

Results—

Among 146 patients (66 males [45.2%] and 80 females [54.8%]; 76 pediatric [52.1%]), contralateral disease progression was detected in 43 patients (29.5%) after a mean follow-up of 4.3±2.4 years. Multivariate analysis showed that SIG SD was significantly associated with this progression (odds ratio, 13.001 [95% CI, 1.764−95.794],
P
=0.012). In receiver operating characteristic curve analysis, SIG SD predicted the contralateral progression with area under the curve values of 0.803 (95% CI, 0.726−0.880,
P
<0.001). The regression model was reproduced in the external cohort of 31 patients.

Conclusions—
Increased spatial variability of the endothelial shear stress around the normally appearing terminal internal carotid artery, as measured by SIG SD in time-of-flight sequences, may predict the contralateral progression of unilateral moyamoya disease.
Clinically feasible brain morphometric similarity network construction approaches with restricted magnetic resonance imaging acquisitions
Authors: King Daniel J. , Wood Amanda G. 
Published: December 2019

Abstract
Morphometric similarity networks (MSNs) estimate organization of the cortex as a biologically meaningful set of similarities between anatomical features at the macro- and microstructural level, derived from multiple structural MRI (sMRI) sequences. These networks are clinically relevant, predicting 40% variance in IQ. However, the sequences required (T1w, T2w, DWI) to produce these networks are longer acquisitions, less feasible in some populations. Thus, estimating MSNs using features from T1w sMRI is attractive to clinical and developmental neuroscience. We studied whether reduced-feature approaches approximate the original MSN model as a potential tool to investigate brain structure. In a large, homogenous dataset of healthy young adults (from the Human Connectome Project, HCP), we extended previous investigations of reduced-feature MSNs by comparing not only T1w-derived networks, but also additional MSNs generated with fewer MR sequences, to their full acquisition counterparts. We produce MSNs that are highly similar at the edge level to those generated with multimodal imaging; however, the nodal topology of the networks differed. These networks had limited predictive validity of generalized cognitive ability. Overall, when multimodal imaging is not available or appropriate, T1w-restricted MSN construction is feasible, provides an appropriate estimate of the MSN, and could be a useful approach to examine outcomes in future studies.
Al-Ṣafadī, His Critics, and the Drag of Philological Time
Authors: Talib Adam 
Published: December 2019

AbstractPhilology was more than a scholarly tool in the system of classical Arabo-Islamic writing; it was a cognitive model. This cognitive model was embodied by scholars and repeatedly performed by them in oral and written expression. It can be understood as a habitus. This article takes seriously pre-modern critiques of a revisionist darling al-Ṣafadī’s masterful commentary al-Ghayth al-musajjam fī sharḥ «Lāmiyyat al-ʿAjam» to consider the cognitive logic of this philological habitus and the ways in which modern scholarly agendas manipulate the chronological plane of Arabic literary history.
A Midlatitude Climatology and Interannual Variability of 200- and 500-hPa Cut-Off Lows
Authors: Muñoz Cristian , Schultz David , Vaughan Geraint 
Published: December 2019

AbstractA climatology of midlatitude 200- and 500-hPa cut-off low systems in the Northern and Southern Hemispheres is constructed from the NCEP–NCAR reanalysis by detecting and tracking, under one consistent method, all of the systems that persisted for more than 36 h for the 58 years of 1960–2017. This method identifies a cut-off low as a cold-core geopotential height minimum that is isolated from the main westerlies and with a strong temperature gradient on its eastern flank. The obtained spatial and seasonal distributions show preferred regions of occurrence and that within these regions there is a level-dependent seasonality of cut-off lows. Whereas 200-hPa systems are more frequent in summer and autumn, 500-hPa systems are more evenly distributed throughout the seasons. Within each region and at each level, the annual number of cut-off lows has been increasing over time, trends that are consistent with documented signals of climate change such as a weakening and poleward shift of the subtropical jets and an increase in blocking frequency. These trends explain as much as 64% of the variance in the annual number of cut-off lows. The contribution of the annular modes and El Niño–Southern Oscillation to the interannual variability of the number of cut-off lows per season in each hemisphere is also investigated. Only the Northern Hemisphere annular mode has a statistically significant negative correlation throughout all seasons that explains 18%–45% of the variance in the yearly number of Northern Hemisphere 500-hPa cut-off lows.
Global Estimates of Land Surface Water Fluxes from SMOS and SMAP Satellite Soil Moisture Data
Authors: Sadeghi Morteza , Ebtehaj Ardeshir , Crow Wade T. , Gao Lun , Purdy Adam J. , Fisher Joshua B. , Jones Scott B. , Babaeian Ebrahim , Tuller Markus 
Published: December 2019

AbstractIn-depth knowledge about the global patterns and dynamics of land surface net water flux (NWF) is essential for quantification of depletion and recharge of groundwater resources. Net water flux cannot be directly measured, and its estimates as a residual of individual surface flux components often suffer from mass conservation errors due to accumulated systematic biases of individual fluxes. Here, for the first time, we provide direct estimates of global NWF based on near-surface satellite soil moisture retrievals from the Soil Moisture Ocean Salinity (SMOS) and Soil Moisture Active Passive (SMAP) satellites. We apply a recently developed analytical model derived via inversion of the linearized Richards’ equation. The model is parsimonious, yet yields unbiased estimates of long-term cumulative NWF that is generally well correlated with the terrestrial water storage anomaly from the Gravity Recovery and Climate Experiment (GRACE) satellite. In addition, in conjunction with precipitation and evapotranspiration retrievals, the resultant NWF estimates provide a new means for retrieving global infiltration and runoff from satellite observations. However, the efficacy of the proposed approach over densely vegetated regions is questionable, due to the uncertainty of the satellite soil moisture retrievals and the lack of explicit parameterization of transpiration by deeply rooted plants in the proposed model. Future research is needed to advance this modeling paradigm to explicitly account for plant transpiration.
Another Note on Rossby Wave Energy Flux
Authors: Durland Theodore S. , Farrar J. Thomas 
Published: December 2019

AbstractLonguet-Higgins in 1964 first pointed out that the Rossby wave energy flux as defined by the pressure work is not the same as that defined by the group velocity. The two definitions provide answers that differ by a nondivergent vector. Longuet-Higgins suggested that the problem arose from ambiguity in the definition of energy flux, which only impacts the energy equation through its divergence. Numerous authors have addressed this issue from various perspectives, and we offer one more approach that we feel is more succinct than previous ones, both mathematically and conceptually. We follow the work described by Cai and Huang in 2013 in concluding that there is no need to invoke the ambiguity offered by Longuet-Higgins. By working directly from the shallow-water equations (as opposed to the more involved quasigeostrophic treatment of Cai and Huang), we provide a concise derivation of the nondivergent pressure work and demonstrate that the two energy flux definitions are equivalent when only the divergent part of the pressure work is considered. The difference vector comes from the nondivergent part of the geostrophic pressure work, and the familiar westward component of the Rossby wave group velocity comes from the divergent part of the geostrophic pressure work. In a broadband wave field, the expression for energy flux in terms of a single group velocity is no longer meaningful, but the expression for energy flux in terms of the divergent pressure work is still valid.
Occupational Therapists as Street-Level Bureaucrats: Leveraging the Political Nature of Everyday Practice
Authors: Aldrich Rebecca M. , Rudman Debbie Laliberte 
Published: December 2019

Background. As front-line service providers who often work in systems regulated by governmental bodies, occupational therapists can be conceptualized as “street-level bureaucrats” ( Lipsky, 1980/2010 ) who effect and are affected by policy. Purpose. Drawing on understandings from a study of long-term unemployment, this article proposes that occupational therapists, as street-level bureaucrats, respond to inter-related policies and systems in ways that can perpetuate, resist, or transform opportunities for doing and being. Key Issues. By highlighting practitioners’ everyday negotiation of governmental, organizational, and professional power relations, the notion of street-level bureaucracy illuminates the political nature of practice as well as the possibilities and boundaries that policy can place on ideal forms and outcomes of practice. Implications. Framing occupational therapists as street-level bureaucrats reinforces practitioners’ situatedness as political actors. Mobilizing this framing can enhance awareness of occupational therapists’ exercise of discretion, which can be investigated as a basis for occupation-focused and emancipatory forms of practice.
Does child abuse have an impact on self-esteem, depression, anxiety and stress conditions of individuals?
Authors: Berber Çelik Çiğdem , Odacı Hatice 
Published: December 2019

Background: The present study addressed the effects of child abuse in early adulthood. Aims: The purpose of the study was to determine the direct and indirect effects of child abuse on self-esteem, depression, anxiety and stress levels. Method: The participants of the study were 636 students (477 females and 159 males) studying at three different state universities in Turkey. Data were collected through ‘Childhood Trauma Questionnaire’, ‘Depression Anxiety Stress Scale (DASS)’, ‘Two-Dimensional Self-Esteem Scale (Self-Liking/Self-Competence)’ and ‘Demographic Information Form’. The obtained data were analyzed with Pearson product-moment correlation coefficient and path analysis techniques via SPSS 23 and AMOS 22. Results: Considering the relationship between the variables, child abuse was found to be negatively correlated with self-esteem, while it was positively correlated with depression, anxiety and stress. As a result of the path analysis, it was observed that child abuse affected self-esteem directly in the negative way. Throughout the analysis, self-esteem was found to have a direct and negative effect on depression, anxiety and stress, respectively. Child abuse was also found to have an indirect effect on depression, anxiety and stress. Conclusion: Self-esteem had full mediation effect between child abuse, and depression, anxiety and stress.
Utility of platelet function testing in stent-assisted coiling of cerebral aneurysms
Authors: Wirtz Mirja M , Schirmer Clemens M , Goren Oded , Bohan Christian O , Dalal Shamsher , Weiner Gregory , Foreman Paul M , Griessenauer Christoph J 
Published: December 2019

Background Thromboembolic complications are the primary risks of stent-coiling of cerebral aneurysms. The utility of platelet function testing in stent-assisted aneurysm coiling remains controversial. This study aimed to assess a pharmacy-mediated antiplatelet management protocol for stent-assisted coiling. Methods Stent-coiled aneurysms at an academic institution in the United States between 2015 and 2018 were retrospectively reviewed. All patients were managed using a pharmacy-mediated antiplatelet protocol, which required repeated platelet function testing and subsequent dose adjustments. Medication dosage, number of adjustments, aspirin reaction units (ARU) and P2Y12 reaction units (PRU), as well as complication rates, angiographic and functional outcome were analyzed. Results A total of 56 aneurysms (median size 5 mm, range 2.6–14.0 mm) in 54 patients (median age 58.5 years) were treated with stent-assisted coil embolization. Most aneurysms were located at the basilar tip (28.6%). Median pre-procedure ARU and PRU were 442.5 (range 363–594) and 123.5 (range 1–252), respectively. Approximately two-thirds of all procedures required at least one aspirin dose adjustment and 88.5% of procedures required at least one clopidogrel dose adjustment. There were two (3.6%) thromboembolic complications. One of the thromboembolic complications occurred in a patient where the pharmacy-mediated protocol was violated. There were no hemorrhagic complications. Last imaging follow-up demonstrated complete aneurysm occlusion in 83.9%. Conclusion In patients where the pharmacy-mediated antiplatelet protocol was followed, the thromboembolic complication rate was 1.8%. This complication rate compares favorably to those reported in large contemporary series. Nevertheless, the pharmacy-mediated protocol places a significant burden on both the patient and healthcare system.