bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analyzing Infrastructure as Code to Prevent Intra-update Sniping Vulnerabilities
Authors: Lepiller Julien , Piskac Ruzica , Schäf Martin , Santolucito Mark 
Published: March 2021

AbstractInfrastructure as Code is a new approach to computing infrastructure management that allows users to leverage tools such as version control, automatic deployments, and program analysis for infrastructure configurations. This approach allows for faster and more homogeneous configuration of a complete infrastructure. Infrastructure as Code languages, such as CloudFormation or TerraForm, use a declarative model so that users only need to describe the desired state of the infrastructure. However, in practice, these languages are not processed atomically. During an upgrade, the infrastructure goes through a series of intermediate states. We identify a security vulnerability that occurs during an upgrade even when the initial and final states of the infrastructure are secure, and we show that those vulnerability are possible in Amazon’s AWS and Google Cloud. We call such attacks intra-update sniping vulnerabilities. In order to mitigate this shortcoming, we present a technique that detects such vulnerabilities and pinpoints the root causes of insecure deployment migrations. We implement this technique in a tool, Häyhä, that uses dataflow graph analysis. We evaluate our tool on a set of open-source CloudFormation templates and find that it is scalable and could be used as part of a deployment workflow.
Syntax-Guided Quantifier Instantiation
Authors: Niemetz Aina , Preiner Mathias , Reynolds Andrew , Barrett Clark , Tinelli Cesare 
Published: March 2021

AbstractThis paper presents a novel approach for quantifier instantiation in Satisfiability Modulo Theories (SMT) that leverages syntax-guided synthesis (SyGuS) to choose instantiation terms. It targets quantified constraints over background theories such as (non)linear integer, reals and floating-point arithmetic, bit-vectors, and their combinations. Unlike previous approaches for quantifier instantiation in these domains which rely on theory-specific strategies, the new approach can be applied to any (combined) theory, when provided with a grammar for instantiation terms for all sorts in the theory. We implement syntax-guided instantiation in the SMT solver CVC4, leveraging its support for enumerative SyGuS. Our experiments demonstrate the versatility of the approach, showing that it is competitive with or exceeds the performance of state-of-the-art solvers on a range of background theories.
For a Few Dollars More
Authors: Haslbeck Maximilian P. L. , Lammich Peter 
Published: March 2021

AbstractWe present a framework to verify both, functional correctness and worst-case complexity of practically efficient algorithms. We implemented a stepwise refinement approach, using the novel concept of resource currencies to naturally structure the resource analysis along the refinement chain, and allow a fine-grained analysis of operation counts. Our framework targets the LLVM intermediate representation. We extend its semantics from earlier work with a cost model. As case study, we verify the correctness and $$O(n\log n)$$

O
(
n
log
n
)

worst-case complexity of an implementation of the introsort algorithm, whose performance is on par with the state-of-the-art implementation found in the GNU C++ Library.
Session Coalgebras: A Coalgebraic View on Session Types and Communication Protocols
Authors: Keizer Alex C. , Basold Henning , Pérez Jorge A. 
Published: March 2021

AbstractCompositional methods are central to the development and verification of software systems. They allow breaking down large systems into smaller components, while enabling reasoning about the behaviour of the composed system. For concurrent and communicating systems, compositional techniques based on behavioural type systems have received much attention. By abstracting communication protocols as types, these type systems can statically check that programs interact with channels according to a certain protocol, whether the intended messages are exchanged in a certain order. In this paper, we put on our coalgebraic spectacles to investigate session types, a widely studied class of behavioural type systems. We provide a syntax-free description of session-based concurrency as states of coalgebras. As a result, we rediscover type equivalence, duality, and subtyping relations in terms of canonical coinductive presentations. In turn, this coinductive presentation makes it possible to elegantly derive a decidable type system with subtyping for $$\pi $$
π
-calculus processes, in which the states of a coalgebra will serve as channel protocols. Going full circle, we exhibit a coalgebra structure on an existing session type system, and show that the relations and type system resulting from our coalgebraic perspective agree with the existing ones.
Densities of Almost Surely Terminating Probabilistic Programs are Differentiable Almost Everywhere
Authors: Mak Carol , Ong C.-H. Luke , Paquet Hugo , Wagner Dominik 
Published: March 2021

AbstractWe study the differential properties of higher-order statistical probabilistic programs with recursion and conditioning. Our starting point is an open problem posed by Hongseok Yang: what class of statistical probabilistic programs have densities that are differentiable almost everywhere? To formalise the problem, we consider Statistical PCF (SPCF), an extension of call-by-value PCF with real numbers, and constructs for sampling and conditioning. We give SPCF a sampling-style operational semantics à la Borgström et al., and study the associated weight (commonly referred to as the density) function and value function on the set of possible execution traces.Our main result is that almost surely terminating SPCF programs, generated from a set of primitive functions (e.g. the set of analytic functions) satisfying mild closure properties, have weight and value functions that are almost everywhere differentiable. We use a stochastic form of symbolic execution to reason about almost everywhere differentiability. A by-product of this work is that almost surely terminatingdeterministic(S)PCF programs with real parameters denote functions that are almost everywhere differentiable.Our result is of practical interest, as almost everywhere differentiability of the density function is required to hold for the correctness of major gradient-based inference algorithms.
Automated Termination Analysis of Polynomial Probabilistic Programs
Authors: Moosbrugger Marcel , Bartocci Ezio , Katoen Joost-Pieter , Kovács Laura 
Published: March 2021

AbstractThe termination behavior of probabilistic programs depends on the outcomes of random assignments. Almost sure termination (AST) is concerned with the question whether a program terminates with probability one on all possible inputs. Positive almost sure termination (PAST) focuses on termination in a finite expected number of steps. This paper presents a fully automated approach to the termination analysis of probabilistic while-programs whose guards and expressions are polynomial expressions. As proving (positive) AST is undecidable in general, existing proof rules typically provide sufficient conditions. These conditions mostly involve constraints on supermartingales. We consider four proof rules from the literature and extend these with generalizations of existing proof rules for (P)AST. We automate the resulting set of proof rules by effectively computing asymptotic bounds on polynomials over the program variables. These bounds are used to decide the sufficient conditions – including the constraints on supermartingales – of a proof rule. Our software tool Amber can thus check AST, PAST, as well as their negations for a large class of polynomial probabilistic programs, while carrying out the termination reasoning fully with polynomial witnesses. Experimental results show the merits of our generalized proof rules and demonstrate that Amber can handle probabilistic programs that are out of reach for other state-of-the-art tools.
Data Flow Analysis of Asynchronous Systems using Infinite Abstract Domains
Authors: Athaiya Snigdha , Komondoor Raghavan , Kumar K. Narayan 
Published: March 2021

AbstractAsynchronous message-passing systems are employed frequently to implement distributed mechanisms, protocols, and processes. This paper addresses the problem of precise data flow analysis for such systems. To obtain good precision, data flow analysis needs to somehow skip execution paths that read more messages than the number of messages sent so far in the path, as such paths are infeasible at run time. Existing data flow analysis techniques do elide a subset of such infeasible paths, but have the restriction that they admit only finite abstract analysis domains. In this paper we propose a generalization of these approaches to admit infinite abstract analysis domains, as such domains are commonly used in practice to obtain high precision. We have implemented our approach, and have analyzed its performance on a set of 14 benchmarks. On these benchmarks our tool obtains significantly higher precision compared to a baseline approach that does not elide any infeasible paths and to another baseline that elides infeasible paths but admits only finite abstract domains.
Sound and Complete Concolic Testing for Higher-order Functions
Authors: You Shu-Hung , Findler Robert Bruce , Dimoulas Christos 
Published: March 2021

AbstractHigher-order functions have become a staple of modern programming languages. However, such values stymie concolic testers, as the SMT solvers at their hearts are inherently first-order.This paper lays a formal foundations for concolic testing higher-order functional programs. Three ideas enable our results: (i) our tester considers only program inputs in a canonical form; (ii) it collects novel constraints from the evaluation of the canonical inputs to search the space of inputs with partial help from an SMT solver and (iii) it collects constraints from canonical inputs even when they are arguments to concretized calls. We prove that (i) concolic evaluation is sound with respect to concrete evaluation; (ii) modulo concretization and SMT solver incompleteness, the search for a counter-example succeeds if a user program has a bug and (iii) this search amounts to directed evolution of inputs targeting hard-to-reach corners of the program.
Verified Software Units
Authors: Beringer Lennart 
Published: March 2021

AbstractModularity - the partitioning of software into units of functionality that interact with each other via interfaces - has been the mainstay of software development for half a century. In case of the C language, the main mechanism for modularity is the compilation unit / header file abstraction. This paper complements programmatic modularity for C with modularity idioms for specification and verification in the context of Verifiable C, an expressive separation logic for CompCert . Technical innovations include (i)abstract predicate declarations– existential packages that combine Parkinson & Bierman’s abstract predicates with their client-visible reasoning principles; (ii)residualpredicates, which help enforcing data abstraction in callback-rich code; and (iii) an application to pure (Smalltalk-style) objects that connects code verification to model-level reasoning about features such as subtyping,self, inheritance, and late binding. We introduce our techniques using concrete example modules that have all been verified using the Coq proof assistant and combine to fully linked verified programs using a novel, abstraction-respecting component composition rule for Verifiable C.
Perturbative calculations of entanglement entropy
Authors: Dadras Pouria , Kitaev Alexei 
Published: March 2021

Abstract
This paper is an attempt to extend the recent understanding of the Page curve for evaporating black holes to more general systems coupled to a heat bath. Although calculating the von Neumann entropy by the replica trick is usually a challenge, we have identified two solvable cases. For the initial section of the Page curve, we sum up the perturbation series in the system-bath coupling κ; the most interesting contribution is of order 2s, where s is the number of replicas. For the saturated regime, we consider the effect of an external impulse on the entropy at a later time and relate it to OTOCs. A significant simplification occurs in the maximal chaos case such that the effect may be interpreted in terms of an intermediate object, analogous to the branching surface of a replica wormhole.
Health-related quality of life in refugee minors from Syria, Iraq and Afghanistan resettled in Sweden: a nation-wide, cross-sectional study
Authors: Solberg Øivind , Sengoelge Mathilde , Johnson-Singh Charisse M. , Vaez Marjan , Eriksson Anna-Karin , Saboonchi Fredrik 
Published: March 2021

Abstract
Purpose
To examine health-related quality of life (HRQoL) in refugee minors resettled in Sweden and compare results to a European reference population, while exploring associations between sociodemographic factors and HRQoL dimensions.

Methods
A cross-sectional, nation-wide study was conducted with a stratified sample of refugee minors ages 12–15 and 16–18 from Afghanistan, Iraq and Syria, resettled in Sweden between 2014 and 2018. HRQoL was measured using KIDSCREEN-27. HRQoL dimension scores of the sample were compared to mean scores of European age and gender-matched reference population. Associations between sociodemographic factors and HRQoL dimensions were investigated with independent t tests and ANOVA. A multivariable regression analysis was performed to identify the sociodemographic factors associated with HRQoL.

Results
The questionnaire was sent to 10,000 potential respondents. The response rate was 26%, yielding n = 2559 refugee minors (boys 55%, girls 45%) in the study sample. Compared to European references, minors in the present study had significantly lower scores of HRQoL within psychological wellbeing and peers and social support, whereas levels for autonomy and parent/guardian relations and school environment were higher. Several sociodemographic factors were significantly associated with all HRQoL dimensions, with those 16–18 years old, having average or poor family economy, and living with an unrelated adult or family reporting lower levels of HRQoL. Minors from Afghanistan had significantly lower scores of HRQoL for all dimensions compared to those from Iraq and Syria.

Conclusion
Refugee minors had significantly lower levels of HRQoL for psychological wellbeing and peers and social support compared to European references. Future research should further investigate this potential HRQoL gap further.
The mental health of ex-prisoners: analysis of the 2014 English National Survey of Psychiatric Morbidity
Authors: Bebbington Paul E. , McManus Sally , Coid Jeremy W. , Garside Richard , Brugha Terry 
Published: March 2021

Abstract
Purpose
Prisoners experience extremely high rates of psychiatric disturbance. However, ex-prisoners have never previously been identified in representative population surveys to establish how far this excess persists after release. Our purpose was to provide the first community-based estimate of ex-prisoners’ mental health in England using the data from the 2014 Adult Psychiatric Morbidity Survey (APMS).

Methods
APMS 2014 provides cross-sectional data from a random sample (N = 7546) of England’s household population aged 16 or above. Standardised instruments categorised psychiatric disorders and social circumstances. Participants who had been in prison were compared with the rest of the sample.

Results
One participant in seventy had been in prison (1.4%; 95% CI 1.1–1.7; n = 103). Ex-prisoners suffered an excess of current psychiatric problems, including common mental disorders (CMDs), psychosis, post-traumatic disorder, substance dependence, and suicide attempts. They were more likely to screen positive for attention-deficit/hyperactivity disorder and autistic traits, to have low verbal IQ, and to lack qualifications. They disclosed higher rates of childhood adversity, including physical and sexual abuse and local authority care. The odds (1.88; 95% CI 1.02–3.47) of CMDs were nearly doubled in ex-prisoners, even after adjusting for trauma and current socioeconomic adversity.

Conclusions
Prison experience is a marker of enduring psychiatric vulnerability, identifying an important target population for intervention and support. Moreover, the psychiatric attributes of ex-prisoners provide the context for recidivism. Without effective liaison between the criminal justice system and mental health services, the vulnerability of ex-prisoners to relapse and to reoffending will continue, with consequent personal and societal costs.
Local Spatialized Knowledge of Threats to Forest Conservation in Ghana’s High Forest Zone
Authors: Somuah Dorcas Peggy , Ros–Tonen Mirjam A. F. , Baud Isa 
Published: March 2021

AbstractAlthough deforestation rates are declining, protected forest areas remain under threat. While the importance of spatialized (‘mapped’) community knowledge for conservation planning is acknowledged in scientific literature, the integration of such knowledge in forest governance and conservation planning remains scarce, particularly in Ghana. This paper aims to make clear how participatory spatial knowledge tools and geographic information systems can be used to assess the threats to forest conservation in Ghana’s high forest zone. The results show that holders of spatial community-embedded knowledge not only sketch-mapped the location and spatial distribution of the threats to forest conservation in the forest reserves, but also provided information on the actors they perceived to be causing such threats. Such information is not available in forest inventories conducted by the responsible government agencies, but is needed to focus conservation strategies and make them more effective. Maps with the anticipated condition of the forest in 10 years’ time furthermore provided insights which can help governance actors to deal with the underlying drivers of forest degradation. This suggests that local spatialized knowledge needs to be integrated into the institutional arrangements for the governance of forested landscapes, and that such governance cannot be effective without the inclusion of local people’s knowledge. Due consideration is however to be given to the conditions that ensure that spatialized knowledge production and its use in landscape management decision-making occurs in an inclusive manner.
Two Marine Desulfotomaculum spp. of Different Origin are Capable of Utilizing Acetone and Higher Ketones
Authors: Frey Jasmin , Kaßner Sophie , Schink Bernhard 
Published: March 2021

AbstractDegradation of acetone and higher ketones has been described in detail for aerobic and nitrate-reducing bacteria. Among sulfate-reducing bacteria, degradation of acetone and other ketones is still an uncommon ability and has not been understood completely yet. In the present work, we show that Desulfotomaculum arcticum and Desulfotomaculum geothermicum are able to degrade acetone and butanone. Total proteomics of cell-free extracts of both organisms indicated an involvement of a thiamine diphosphate-dependent enzyme, a B12-dependent mutase, and a specific dehydrogenase during acetone degradation. Similar enzymes were recently described to be involved in acetone degradation by Desulfococcus biacutus. As there are so far only two described sulfate reducers able to degrade acetone, D. arcticum and D. geothermicum represent two further species with this capacity. All these bacteria appear to degrade acetone via the same set of enzymes and therefore via the same pathway.
Pelagic deep-sea fauna observed on video transects in the southern Norwegian Sea
Authors: Neitzel Philipp , Hosia Aino , Piatkowski Uwe , Hoving Henk-Jan 
Published: March 2021

AbstractObservations of the diversity, distribution and abundance of pelagic fauna are absent for many ocean regions in the Atlantic, but baseline data are required to detect changes in communities as a result of climate change. Gelatinous fauna are increasingly recognized as vital players in oceanic food webs, but sampling these delicate organisms in nets is challenging. Underwater (in situ) observations have provided unprecedented insights into mesopelagic communities in particular for abundance and distribution of gelatinous fauna. In September 2018, we performed horizontal video transects (50–1200 m) using the pelagic in situ observation system during a research cruise in the southern Norwegian Sea. Annotation of the video recordings resulted in 12 abundant and 7 rare taxa. Chaetognaths, the trachymedusa Aglantha digitale and appendicularians were the three most abundant taxa. The high numbers of fishes and crustaceans in the upper 100 m was likely the result of vertical migration. Gelatinous zooplankton included ctenophores (lobate ctenophores, Beroe spp., Euplokamis sp., and an undescribed cydippid) as well as calycophoran and physonect siphonophores. We discuss the distributions of these fauna, some of which represent the first record for the Norwegian Sea.
Arthroscopic anatomy of the posterolateral corner of the knee: anatomic relations and arthroscopic approaches
Authors: Frings Jannik , Weiß Sebastian , Kolb Jan , Behrendt Peter , Frosch Karl-Heinz , Krause Matthias 
Published: March 2021

Abstract
Introduction
Although open-surgical techniques for the reconstruction of the posterolateral corner (PLC) are well established, the use of arthroscopic procedures has recently increased. When compared with open surgical preparation, arthroscopic orientation in the PLC is challenging and anatomic relations may not be familiar. Nevertheless, a profound knowledge of anatomic key structures and possible structures at risk as well as technical variations of arthroscopic approaches are mandatory to allow a precise and safe surgical intervention.

Materials and methods
In a cadaveric video demonstration, an anterolateral (AL), anteromedial (AM), posteromedial (PM) and posterolateral (PL) portal, as well as a transseptal approach (TSA) were developed. Key structures of the PLC were defined and sequentially exposed during posterolateral arthroscopy. Finally, anatomic relations of all key structures were demonstrated.

Results
All key structures of the PLC can be visualized during arthroscopy. Thereby, careful portal placement is crucial in order to allow an effective exposure. Two alternatives of the TSA were described, depending on the region of interest. The peroneal nerve can be visualized dorsal to the biceps femoris tendon (BT), lateral to the soleus muscle (SM) and about 3 cm distal to the fibular styloid (FS). The distal attachment of the fibular collateral ligament (FCL) can be exposed on the lateral side of the fibular head (FH). The fibular attachment of the popliteofibular ligament (PFL) is exposed at the tip of the FS.

Conclusion
Arthroscopy of the posterolateral recessus allows full visualization of all key structures of the posterolateral corner, which provides the basis for anatomic and safe drill channel placement in PLC reconstruction. A sufficient exposure of relevant anatomic landmarks and precise portal preparation reduce the risk of iatrogenic vascular and peroneal nerve injury.