bluuebunny/crossref_metadata_2025 huggingface dataset:
Knowledge of Objective ‘Oughts’: Monotonicity and the New Miners Puzzle
Authors: Muñoz Daniel , Spencer Jack
Published: May 2020

In the classic Miners case, an agent subjectively ought to do what they know is objectively wrong. This case shows that the subjective and objective ‘oughts’ are somewhat independent. But there remains a powerful intuition that the guidance of objective ‘oughts’ is more authoritative—so long as we know what they tell us. We argue that this intuition must be given up in light of a monotonicity principle, which undercuts the rationale for saying that objective ‘oughts’ are an authoritative guide for agents and advisors.
The role of light quality of photoperiodic lighting on photosynthesis, flowering and metabolic profiling in Ranunculus asiaticus L.
Authors: Modarelli Giuseppe C. , Arena Carmen , Pesce Giuseppe , Dell'Aversana Emilia , Fusco Giovanna M. , Carillo Petronia , De Pascale Stefania , Paradiso Roberta
Published: May 2020

Photoperiodic light quality affects flowering of long day plants, by influencing the phytochrome photoequilibria (PPE) at plant level; however, the most effective light spectrum to promote flowering is still unknown for most of the flower crops. We evaluated the influence of light spectrum of three light sources, with different induced PPE, on photosynthesis, metabolic profiling, plant growth and flowering in two hybrids of Ranunculus asiaticus L., MBO (early flowering) and MDR (medium earliness). Three photoperiodic treatments were compared to natural day length (NL): white fluorescent light (PPE 0.84), light emitting diodes (LEDs) with red:far red (R:FR) light at 3:1 ratio (PPE, 0.84) and LEDs with R:FR light at 1:3 ratio (PPE 0.63). Under natural light, net photosynthesis was higher in MDR than in MBO, while photochemistry was similar in the hybrids. Compared to NL, photoperiodic treatments did not affect net photosynthesis, while they promoted the quantum yield of PSII and reduced the non‐photochemical quenching. Under NL, plant growth was greater in MBO, while flowering started earlier in MDR and flowers characteristics were similar in the hybrids. Despite the greater sensitivity of MDR plants in terms of metabolism, photoperiodic lighting improved plant growth and reduced the flowering time only in MBO, with a stronger effect under R:FR 3:1 light. MDR plants were characterized by higher soluble sugars, polyphenols, photosynthetic pigments and proteins, while MBO plants by higher starch and amino acid content. The morphological effects of photoperiodic light quality and the hybrid‐specific response should be taken into account to optimize lighting protocols in commercial farms.
A Soft‐Path Solution to Risk Reduction by Modeling Medical Waste Disposal Center Location‐Allocation Optimization
Authors: Yao Liming , Xu Zhongwen , Zeng Ziqiang
Published: May 2020

The risk of medical waste pollution and huge demand of daily medical waste disposal pose great difficulties to medical waste management. Establishing medical waste disposal centers (MWDCs) is considered one of the ways to reduce the environmental and public risk of medical waste pollution. However, how to serve the medical waste disposal demand in optimal MWDCs’ locations is a key challenge due to the complexity of the whole system and relationships among stakeholders. This article develops a soft‐path solution for reducing risks as well as mitigating the related costs by optimizing the MWDC location‐allocation problem. A risk mitigation‐oriented bilevel equilibrium optimization model is developed for modeling the Stackelberg game behavior between the local government and the medical institutions. The objectives of the local government are minimizing the total risk of loss, the subsidy costs, and the investment cost of building the MWDCs, while minimizing the disposal and transportation costs are the objectives at the medical institution level. Fuzzy random variables are introduced by combining insufficient historical data with expert knowledge via consulting surveys to describe the coexisting uncertainties in the data. To solve the model, a hybrid approach combined with the interactive fuzzy programming technique and an Entropy‐Boltzmann selection‐based genetic algorithm are designed and tested. The Chengdu Medical Waste Disposal Centers Planning Project is used as a practical application. The results show that it is possible to achieve a balanced market with higher economic efficiency and significantly reduced risk through an appropriate principle of interactive actions between the bilevel stakeholders.
Revisiting ‘Bordering, Ordering and Othering’: An Invitation to ‘Migrate’ Towards A Politics of Hope
Authors: Brambilla Chiara
Published: May 2020

‘Bordering, Ordering and Othering’ is a landmark in the scholarship of the ‘processual turn’ in border studies. This commentary provides some reflections on van Houtum and van Naerssen’s paper that seek to foster not only an appreciation of the research avenues it has opened but also a critical interrogation of its shortcomings. Rethinking borders as processes has significantly contributed to the conceptual evolution of borders. And yet, I am concerned with how the b/ordering‐othering perspective can be questioned and broadened. In so doing, I conclude by taking up van Houtum and van Naerssen’s invitation to problematise the border, questioning certainty and securities provided by the exclusive modern state‐centric way of thinking borders based on fixed and everlasting binary framing, which blind us to the constant state of becoming of political and social order. It’s an invitation to ‘migrate’ towards an alternative politics of hope.
Reconsidering the Meta‐ethical Implications of Motivational Internalism and Externalism
Authors: Francén Ragnar
Published: May 2020

Motivational internalism and externalism – that is, theories about moral motivation – have played central roles in meta‐ethical debate mainly because they have been thought to have implications for the constitutive nature of moral judgements. Thus, internalism and externalism have been adduced in favour of and against various versions of cognitivism and non‐cognitivism. This article aims to question a fundamental presupposition behind such arguments. It has standardly been assumed (i) that if motivational internalism is true then moral judgements must consist of attitudes that cannot be had without the relevant motivation, and (ii) that if motivational externalism is true, then moral judgements must consist of attitudes that one can have without being motivated. Against the background of a recent argument to the effect that the first of these assumptions is false, this article develops a parallel argument against the second. If this argument is correct, then motivational externalism is consistent with moral judgements being attitudes that one cannot have without being motivated. Together with the parallel argument concerning internalism, this means that the meta‐ethical significance of internalism and externalism must be reconsidered.
Single-molecule transport kinetics of a glutamate transporter homolog shows static disorder
Authors: Ciftci Didar , Huysmans Gerard H. M. , Wang Xiaoyu , He Changhao , Terry Daniel , Zhou Zhou , Fitzgerald Gabriel , Blanchard Scott C. , Boudker Olga
Published: May 2020

Single-molecule detection of transport turnovers shows a distribution of rates with fast transporters favored by mutations.
Nisin M: a Bioengineered Nisin A Variant That Retains Full Induction Capacity but Has Significantly Reduced Antimicrobial Activity
Authors: O’ Connor Michelle , Field Des , Grainger Aoife , O’ Connor Paula M. , Draper Lorraine , Ross R. Paul , Hill Colin
Published: May 2020

This study describes the generation of a nisin variant with superior characteristics for use in the NICE protein expression system. The variant, termed nisin M, retains an induction capacity comparable to that of wild-type nisin A but exhibits significantly reduced antimicrobial activity and can therefore be used at concentrations that are normally toxic to the expression host.
Newly Named Klebsiella aerogenes (formerly Enterobacter aerogenes) Is Associated with Poor Clinical Outcomes Relative to Other
Enterobacter
Species in Patients with Bloodstream Infection
Authors: Wesevich Austin , Sutton Granger , Ruffin Felicia , Park Lawrence P. , Fouts Derrick E. , Fowler Vance G. , Thaden Joshua T.
Published: May 2020

Enterobacter aerogenes
was recently renamed
Klebsiella aerogenes
. This study aimed to identify differences in clinical characteristics, outcomes, and bacterial genetics among patients with
K. aerogenes
versus
Enterobacter
species bloodstream infections (BSI). We prospectively enrolled patients with
K. aerogenes
or
Enterobacter cloacae
complex (
Ecc
) BSI from 2002 to 2015.
Trace metal elements as paleoenvironmental proxies: Why should we account for sedimentation rate variations?
Authors: Crombez Vincent , Rohais Sebastien , Euzen Tristan , Riquier Laurent , Baudin François , Hernandez-Bilbao Eider
Published: May 2020

Trace metal elements (TMEs) are commonly used to reconstruct the environmental conditions present during the deposition of organic-rich sediments. For example, TME concentrations controlled by changes in primary productivity and redox conditions are widely used in paleoenvironmental studies. Recently, these proxies have undergone a resurgence of interest and are commonly used in large-scale (10–1000 km) studies. However, applying these geochemical proxies at basin scale while ignoring variations in sedimentation rates (SR) may lead to misinterpretation of paleoenvironmental conditions. Here, we show how SR can affect the geochemical records and may lead to incorrect interpretations of TME evolution. Accounting for SR, we computed the authigenic fraction accumulation rates of key TMEs in the Upper Montney Formation and Doig Phosphate (Triassic, western Canada), and we correct the concentration of these elements in the Vaca-Muerta Formation (Jurassic–Cretaceous, Argentina). Our SR-corrected TME proxies require a different interpretation of paleoenvironmental conditions (e.g., primary productivity, basin restriction) compared to conventional TME results and highlight that elementary enrichments commonly interpreted as indicative of anoxic depositional environments may reflect low SR and the formation of condensed intervals. This work also introduces a new workflow to account for SR in paleoenvironmental studies at basin scale and over long time periods.
Microbially induced pseudotraces from a Pantanal soda lake, Brazil: Alternative interpretations for Ediacaran simple trails and their limits
Authors: Warren L.V. , Buatois L.A. , Mángano M.G. , Simões M.G. , Santos M.G.M. , Poiré D.G. , Riccomini C. , Assine M.L.
Published: May 2020

Despite the absence of metazoans, structures resembling animal traces are common in a soda lake from the western Brazil Pantanal wetland. Pantanal soda lakes are ecologically extreme environments that preclude complex life, allowing extremophiles to flourish. Direct observation indicates that these structures are pseudotraces, representing groove marks that result from the interaction of wave-transported floating rafts of epibenthic microbial mat fragments with the substrate. Variations in wind/wave direction and intensity result in marks of different size and morphology. The most common pseudotraces are simple and slightly curved, narrow grooves (type 1), whereas others are straight and present raised lateral ridges (type 2). Both are V-shaped in cross section. Type 3 comprises long, sinuous, shallow grooves, displaying internal crescentic laminated infill and U-shaped cross section. The similarity of these pseudotraces to Ediacaran structures usually interpreted as animal trace fossils suggests that care should be exercised in their analysis. A set of criteria is proposed to differentiate microbially induced pseudotraces from trace fossils. Analysis of Ediacaran structures needs to be performed on a case-by-case basis, taking into account morphology, orientation, and preservation style of the structure, sedimentary environment, and presence or absence of microbial mats.
Clinical implementation of circulating tumour DNA testing forEGFRT790M for detection of treatment resistance in non-small cell lung cancer
Authors: Spence Tara , Perera Sheron , Weiss Jessica , Grenier Sylvie , Ranich Laura , Shepherd Frances , Stockley Tracy L
Published: May 2020

Aims

Epidermal growth factor receptor (EGFR) T790M mutations can be detected in the circulating tumour DNA from plasma of patients with non-small cell lung cancer (NSCLC) to triage patients for osimertinib eligibility and monitor patients longitudinally for development of T790M-mediated resistance.

Methods

Using droplet digital PCR (ddPCR), we examined theEGFRT790M status of 343 sequential patients with NSCLC and correlated mutational status with demographic and clinical features. Where available, serial T790M blood test results were assessed to identify clinical triggers and timing of repeat testing.

Results

Of the 343 patients with liquid biopsy test results, 24% were T790M positive. No clear clinical correlation with a T790M positive test result was identified in this study, although the number of metastatic sites did correlate significantly with the presence ofEGFRsensitising mutations (L858R or exon 19 deletion) in patient plasma, as a measure of tumour DNA shedding. Of the 59 serial blood tests from patients that initially tested negative, 14% were positive on sequential testing, at a time interval up to 6 months after an initially negative blood test.

Conclusions

The ddPCR test forEGFRT790M mutations effectively triaged 24% of patients for treatment with osimertinib, avoiding the need for invasive tissue biopsy in these patients. Our findings suggest that initial and repeat ctDNA testing can be used to monitor for acquiredEGFRT790M resistance for NSCLC.
Safety and efficacy of ticagrelor as single antiplatelet therapy in prevention of thromboembolic complications associated with the Pipeline Embolization Device (PED): multicenter experience
Authors: Mohammaden Mahmoud H , English Stephen W , Stapleton Christopher J , Khedr Eman , Shoyb Ahmed , Hegazy Ahmed , Elbassiouny Ahmed
Published: May 2020

Background

Flow diversion (FD) is a common treatment modality for complex intracranial aneurysms. A major concern regarding the use of FD is thromboembolic events (TEE). There is debate surrounding the optimal antiplatelet regimen to prevent TEE. We aim to evaluate the safety and efficacy of ticagrelor as a single antiplatelet therapy (SAPT) for the prevention of TEE following FD for complex aneurysm treatment.

Methods

A retrospective review of a prospectively maintained neuroendovascular database at three endovascular centers was performed. Patients were included if they had an intracranial aneurysm that was treated with FD between January 2018 and September 2019 and were treated with ticagrelor as SAPT. Primary outcomes included early (within 72 hours post-procedure) and late (within 6 months) ischemic events.

Results

A total of 24 patients (mean age 47.7 years) with 36 aneurysms were eligible for analysis, including 15 (62.5%) females. 14 (58.3%) patients presented with subarachnoid hemorrhage. 35 aneurysms arose from the anterior circulation and 1 from the posterior circulation. 23 aneurysms had a saccular morphology, whereas 7 were fusiform and 6 were blister. For the treatment of all 36 aneurysms, 30 procedures were performed with 32 FD devices. Procedural in-stent thrombosis occurred in 2 cases and was treated with intra-arterial tirofiban without complications. Aneurysm re-bleeding was reported in 1 (4.2%) patient. There were no reported early or late TEE. Three patients discontinued ticagrelor due to systemic side effects.

Conclusion

Ticagrelor is a safe and effective SAPT for the prevention of TEE after FD. Large multicenter prospective studies are warranted to validate our findings.
Comparison of NICE and ESC proposed strategies on new onset chest pain and the contemporary clinical utility of pretest probability risk score
Authors: Papachristidis Alexandros , Vaughan George Frederick , Denny Sarah J , Akbari Tamim , Avornyo Edith , Griffiths Tracey , Saunders Emma , Byrne Jonathan , Monaghan Mark J , Al Fakih Khaled
Published: May 2020

Aims

Patients with de novo chest pain are usually investigated non-invasively. The new UK-National Institute for Health and Care Excellence (NICE) guidelines recommend CT coronary angiography (CTCA) for all patients, while European Society of Cardiology (ESC) recommends functional tests. We sought to compare the clinical utility and perform a cost analysis of these recommendations in two UK centres with different primary investigative strategies.

Methods—results

We compared two groups of patients, group A (n=667) and group B (n=654), with new onset chest pain in two neighbouring National Health Service hospitals, each primarily following either ESC (group A) or NICE (group B) guidance. We assessed the clinical utility of each strategy, including progression to invasive coronary angiography (ICA) and revascularisation. We present a retrospective cost analysis in the context of UK tariff for stress echo (£176), CTCA (£220) and ICA (£1001). Finally, we sought to identify predictors of revascularisation in the whole population.

Baseline characteristics in both groups were similar. The progression to ICA was comparable (9.9% vs 12.0%, p=0.377), with similar requirement for revascularisation (4.0% vs 5.0%.; p=0.532). The average cost of investigations per investigated patient was lower in group A (£279.66 vs £325.77), saving £46.11 per patient. The ESC recommended risk score (RS) was found to be the only predictor of revascularisation (OR 1.05, 95% CI 1.04 to 1.06; p<0.001).

Conclusion

Both NICE and ESC-proposed strategies led to similar rates of ICA and need for revascularisation in discrete, but similar groups of patients. The SE-first approach had a lower overall cost by £46.11 per patient, and the ESC RS was the only variable correlated to revascularisation.
Long-term patient-reported outcome measures after injury: National Trauma Research Action Plan (NTRAP) scoping review protocol
Authors: Herrera-Escobar Juan Pablo , Castillo-Angeles Manuel A , Osman Samia Y , Orlas Claudia P , Janjua Mahin B , Abdullah-Arain Muhammad , Reidy Emma , Jarman Molly P , Price Michelle A , Bulger Eileen M , Nehra Deepika , Haider Adil H
Published: May 2020

Background

A significant proportion of patients who survive traumatic injury continue to suffer impaired functional status and increased mortality long after discharge. However, despite the need to improve long-term outcomes, trauma registries in the USA do not collect data on outcomes or care processes after discharge. One of the main barriers is the lack of consensus regarding the optimal outcome metrics.

Objectives

To describe the methodology of a scoping review evaluating current evidence on the available measures for tracking functional and patient-reported outcomes after injury. The aim of the review was to identify and summarize measures that are being used to track long-term functional recovery and patient-reported outcomes among adults after injury.

Methods

A systematic search of PubMed and Embase will be performed using the search terms for the population (adult trauma patients), type of outcomes (long-term physical, mental, cognitive, and quality of life), and measures available to track them. Studies identified will be reviewed and assessed for relevance by at least two reviewers. Data will be extracted and summarized using descriptive statistics and a narrative synthesis of the results. This protocol is being reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) guidelines.

Dissemination

This scoping review will provide information regarding the currently available metrics for tracking functional and patient-reported outcomes after injury. The review will be presented to a multi-disciplinary stakeholder group that will evaluate these outcome metrics using an online Delphi approach to achieve consensus as part of the development of the National Trauma Research Action Plan (NTRAP). The results of this review will be presented at relevant national surgical conferences and published in peer-reviewed scientific journals.
Hydrostatic equilibrium configurations of neutron stars in a non-minimal geometry-matter coupling theory of gravity
Authors: Carvalho G. A. , Moraes P. H. R. S. , dos Santos S. I. , Gonçalves B. S. , Malheiro M.
Published: May 2020

In this work we analyze hydrostatic equilibrium configurations of neutron stars in a non-minimal geometry-matter coupling (GMC) theory of gravity. We begin with the derivation of the hydrostatic equilibrium equations for thef(R, L) gravity theory, whereRandLare the Ricci scalar and Lagrangian of matter, respectively. We assume$$f(R,L)=R/2+[1+\sigma R]L$$f(R,L)=R/2+[1+σR]L, with$$\sigma $$σconstant. To describe matter inside neutron stars we assume a relativistic polytropic equation of state$$p=K \rho ^{\gamma }$$p=Kργ, with$$\rho $$ρbeing the energy density,Kand$$\gamma = 5/3 $$γ=5/3being constants. We also consider the more realistic equation of state (EoS) known as SLy4, which is a Skyrme type one based on effective nuclear interaction. We show that in this theory it is possible to reach the mass of massive pulsars, such as PSR J2215 + 5135, for both equations of state. Also, results for mass-radius relation in GMC gravity are strongly dependent on the stiffness of the EoS.
Spectral asymptotics on stationary space-times
Authors: Strohmaier Alexander , Zelditch Steve
Published: May 2020

We review our recent relativistic generalization of the Gutzwiller–Duistermaat–Guillemin trace formula and Weyl law on globally hyperbolic stationary space-times with compact Cauchy hypersurfaces. We also discuss anticipated generalizations to non-compact Cauchy hypersurface cases.
Modification of the dynamic equation and tunneling radiation of fermions with arbitrary spin in Kerr-Newman-Kasuya black hole space-time
Authors: Tan Xia , Liu Yuzhen , Liu Zhie , Sha Bei , Zhang Jie , Yang Shuzheng
Published: May 2020

According to the Lorentz Invariance Violation originated from the quantum gravitational theory and the string theory, the Rarita-Schwinger equation of arbitrary spin fermions are exactly modified in the high energy case. Then we restudy the dynamic equation of fermions with arbitrary spin in charged Kerr-Newman-Kasuya (KNK) black hole space-time. Moreover, the tunneling radiation characteristics of fermions are studied according to the modified dynamic equation. Therefore, some new expressions for physical quantities such as tunneling rate, surface gravitation, Hawking temperature and entropy of the black hole are corrected. As a result, we calculate that the surface gravitation at the event horizon of the KNK black hole is a constant, and find that the Hawking temperature will increase, but the entropy will decrease with the increasing of correction parameter.
Nonlinear Vibrations of Thermo-Hyperelastic Moderately Thick Cylindrical Shells with 2:1 Internal Resonance
Authors: Xu Jie , Yuan Xuegang , Zhang Hongwu , Zheng Fei , Chen Liqun
Published: May 2020

The nonlinear vibration of a hyperelastic moderately thick cylindrical shell with 2:1 internal resonance in a temperature field is investigated based on the third-order shear deformation theory. A radial harmonic excitation is applied to the shell. First, by employing the higher-order approximation for the curvature-related expansion, the displacement field of the moderately thick cylindrical shell with improved coefficients is derived. For the temperature field with gradient, the shear modulus of the shell is thickness dependent because of the temperature-dependent nature of the hyperelastic materials used. The graphical results manifest that the temperature gradient has a significant impact on the nonlinear vibration of the shell. In addition, the separation of the resonance peak caused by the variations of the structural parameter and temperature will result in a bubble shaped response curve for the shell.
Clifford 3-qubit states
Authors: Perdomo Oscar
Published: May 2020

Let us denote by [Formula: see text] the Clifford group (the circuit or operations generated by Hadamard, [Formula: see text] phase and the controlled-NOT gates) and by [Formula: see text] the set of qubit states that can be prepared by circuits from the Clifford group. In other words, a state [Formula: see text] if [Formula: see text] where [Formula: see text]. We will refer to states in [Formula: see text] as Clifford states. This paper studies the set of all three-qubit Clifford states. We prove that [Formula: see text] has 8640 states and if we define two states [Formula: see text] and [Formula: see text] in [Formula: see text] to be equivalent if [Formula: see text], with [Formula: see text] a local transformation in [Formula: see text], then the resulting quotient space has five orbits. More exactly, [Formula: see text] where the orbit [Formula: see text] is made up of states with entanglement entropy [Formula: see text]. For example, the first orbit [Formula: see text] contains the state [Formula: see text] and corresponds to the unentangled Clifford states. We say that [Formula: see text] is a real state if all its amplitudes [Formula: see text] are real numbers. We also say that an operator is real if all the entries of its matrix representation with respect to the computational basis are real numbers. In this paper, we also study the set of real Clifford 3 qubits and the way this set splits when we identify two real Clifford states [Formula: see text] and [Formula: see text] to be equivalent if [Formula: see text] where [Formula: see text] is a local real Clifford operator. An interesting aspect that follows from this study of Clifford states is the existence of two real Clifford states [Formula: see text] and [Formula: see text] that can be connected with a Clifford local transformation but they cannot be connected with a real Clifford local transformation. This is, the equation [Formula: see text] for [Formula: see text], does have a solution in the set of local transformations from [Formula: see text] but it does not have a solution among the local transformations from [Formula: see text] that are real. We go a little deeper and show that the equation [Formula: see text] does not have a solution for any local operation (not necessarily Clifford) whose entries are real numbers. Finally, we show how the CNOT gates act on the set of Clifford states and also in the set of real Clifford states.
The minimum eccentric distance sum of trees with given distance k-domination number
Authors: Pei Lidan , Pan Xiangfeng
Published: May 2020

Let [Formula: see text] be a positive integer and [Formula: see text] be a simple connected graph. The eccentric distance sum of [Formula: see text] is defined as [Formula: see text], where [Formula: see text] is the maximum distance from [Formula: see text] to any other vertex and [Formula: see text] is the sum of all distances from [Formula: see text]. A set [Formula: see text] is a distance [Formula: see text]-dominating set of [Formula: see text] if for every vertex [Formula: see text], [Formula: see text] for some vertex [Formula: see text]. The minimum cardinality among all distance [Formula: see text]-dominating sets of [Formula: see text] is called the distance [Formula: see text]-domination number [Formula: see text] of [Formula: see text]. In this paper, the trees among all [Formula: see text]-vertex trees with distance [Formula: see text]-domination number [Formula: see text] having the minimal eccentric distance sum are determined.
The integer {k}-domination number of circulant graphs
Authors: Cheng Yen-Jen , Fu Hung-Lin , Liu Chia-An
Published: May 2020

Let [Formula: see text] be a simple undirected graph. [Formula: see text] is a circulant graph defined on [Formula: see text] with difference set [Formula: see text] provided two vertices [Formula: see text] and [Formula: see text] in [Formula: see text] are adjacent if and only if [Formula: see text]. For convenience, we use [Formula: see text] to denote such a circulant graph.

A function [Formula: see text] is an integer [Formula: see text]-domination function if for each [Formula: see text], [Formula: see text] By considering all [Formula: see text]-domination functions [Formula: see text], the minimum value of [Formula: see text] is the [Formula: see text]-domination number of [Formula: see text], denoted by [Formula: see text]. In this paper, we prove that if [Formula: see text], [Formula: see text], then the integer [Formula: see text]-domination number of [Formula: see text] is [Formula: see text].
Unimodal Bandits with Continuous Arms
Authors: Combes Richard , Proutière Alexandre , Fauquette Alexandre
Published: May 2020

We consider stochastic bandit problems with a continuous set of arms and where the expected reward is a continuous and unimodal function of the arm. For these problems, we propose the Stochastic Polychotomy (SP) algorithms, and derive finite-time upper bounds on its regret and optimization error. We show that, for a class of reward functions, the SP algorithm achieves a regret and an optimization error with optimal scalings, i.e., $O(\sqrtT )$ and $O(1/\sqrtT )$ (up to a logarithmic factor), respectively. SP constitutes the first order-optimal algorithm for non-smooth expected reward functions, as well as for smooth functions with unknown smoothness. The algorithm is based on sequential statistical tests used to successively trim an interval that contains the best arm with high probability. These tests exhibit a minimal sample complexity which confers to SP its adaptivity and optimality. Numerical experiments actually reveal that the algorithm even outperforms state-of-the-art algorithms that exploit the knowledge of the smoothness of the reward function. The performance of SP is further illustrated on the problem of setting optimal reserve prices in repeated second-price auctions; there, the algorithm is evaluated on real-world data.
"I run the world's largest historical outreach project and it's on a cesspool of a website." Moderating a Public Scholarship Site on Reddit: A Case Study of r/AskHistorians
Authors: Gilbert Sarah A.
Published: May 2020

Online communities provide important functions in their participants' lives, from providing spaces to discuss topics of interest to supporting the development of close, personal relationships. Volunteer moderators play key roles in maintaining these spaces, such as creating and enforcing rules and modeling normative behavior. While these users play important governance roles in online spaces, less is known about how the work they do is impacted by platform design and culture. r/AskHistorians, a Reddit-based question and answer forum dedicated to providing users with academic-level answers to questions about history, provides an interesting case study on the impact of design and culture because of its unique rules and their strict enforcement by moderators. In this article I use interviews with r/AskHistorians moderators and community members, observation, and the full comment log of a highly upvoted thread to describe the impact of Reddit's design and culture on moderation work. Results show that visible moderation work that is often interpreted as censorship, and the default masculine whiteness of Reddit create challenges for moderators who use the subreddit as a public history site. Nonetheless, r/AskHistorians moderators have carved a space on Reddit where, through their public scholarship work, the community serves as a model for combating misinformation by building trust in academic processes.
"Learning for the Rise of China": Exploring Uses and Gratifications of State-Owned Online Platform
Authors: Lu Alex Jiahong , Xu Xuecong
Published: May 2020

In January 2019, the Chinese Communist Party launched the online platform XueXi QiangGuo, which translates into "Learning for the Rise of China." Within two months, XueXi became the top-downloaded item of the month on Apple's App Store in China. In response, we conducted an interview study with 28 active XueXi users to investigate their uses and gratifications of this state-owned online platform. Our results reveal seven key motivations: compliance, self-status seeking, general information seeking, job support, entertainment, patriotism, and learning. This state-owned platform introduced a new model for official information dissemination and political communication through direct surveillance and monitoring, leveraging and fostering emotional attachment, and offering heterogeneous apolitical content. We discuss the intended and unintended ramifications of these components, highlighting the importance of future CSCW research to critically engage with pluralist political narratives situated in varied societies, especially non-Western democracies.
Do Multilingual Users Prefer Chat-bots that Code-mix? Let's Nudge and Find Out!
Authors: Bawa Anshul , Khadpe Pranav , Joshi Pratik , Bali Kalika , Choudhury Monojit
Published: May 2020

Despite their pervasiveness, current text-based conversational agents (chatbots) are predominantly monolingual, while users are often multilingual. It is well-known that multilingual users mix languages while interacting with others, as well as in their interactions with computer systems (such as query formulation in text-/voice-based search interfaces and digital assistants). Linguists refer to this phenomenon as code-mixing or code-switching. Do multilingual users also prefer chatbots that can respond in a code-mixed language over those which cannot? In order to inform the design of chatbots for multilingual users, we conduct a mixed-method user-study (N=91) where we examine how conversational agents, that code-mix and reciprocate the users' mixing choices over multiple conversation turns, are evaluated and perceived by bilingual users. We design a human-in-the-loop chatbot with two different code-mixing policies -- (a) always code-mix irrespective of user behavior, and (b) nudge with subtle code-mixed cues and reciprocate only if the user, in turn, code-mixes. These two are contrasted with a monolingual chatbot that never code-mixed. Users are asked to interact with the bots, and provide ratings on perceived naturalness and personal preference. They are also asked open-ended questions around what they (dis)liked about the bots. Analysis of the chat logs, users' ratings, and qualitative responses reveal that multilingual users strongly prefer chatbots that can code-mix. We find that self-reported language proficiency is the strongest predictor of user preferences. Compared to the Always code-mix policy, Nudging emerges as a low-risk low-gain policy which is equally acceptable to all users. Nudging as a policy is further supported by the observation that users who rate the code-mixing bot higher typically tend to reciprocate the language mixing pattern of the bot. These findings present a first step towards developing conversational systems that are more human-like and engaging by virtue of adapting to the users' linguistic style.
Trustworthiness Perceptions of Social Media Resources Named after a Crisis Event
Authors: Chauhan Apoorva , Hughes Amanda Lee
Published: May 2020

People often create social media accounts and pages named after crisis events. We call such accounts and pages Crisis Named Resources (CNRs). CNRs share information about crisis events and are followed by many. Yet, they also appear suddenly (at crisis onset) and in most cases, the owners are unknown. Thus, it can be challenging for audiences in particular to know whether to trust (or not trust) these CNRs and the information they provide. In this study, we conducted surveys and interviews with members of the public and experts in crisis informatics, emergency response, and communication studies to evaluate the trustworthiness of CNRs named after the 2017 Hurricane Irma. Findings showed that participants evaluated trustworthiness based on their perceptions of a CNR's content, information source, profile, and owner. Findings also show that if people perceive that a CNR owner has prior experience in crisis response, can help the public to respond to the event, understands the situation, has the best interests of affected individuals in mind, or will correct misinformation, they tend to trust that CNR. Participant demographics and expertise showed no effect on perceptions of trustworthiness.
Exploring Photography in Rural Kenyan Households: Considering "Relational Objects" in CSCW and HCI
Authors: Wyche Susan , Greenwood April , Geyer Brian Samuel
Published: May 2020

Domestic and personal photography are topics of longstanding interest to CSCW and HCI researchers. In this paper, we explore these topics in Bungoma County, Kenya. We used interview and observation methods to investigate how photographs are taken, displayed, organized, and shared, in 23 rural households. To more deeply understand participants' photography practices, we also gave them digital cameras, observed what they did with them, and asked them to engage in a photo-elicitation exercise. Our findings draw attention to the ways photographs are "relational objects" - that is, material objects that support the maintenance, reproduction, and transformation of social relations. We then describe these relations: economic (i.e., working as cameramen producing and distributing printed images); family (i.e., parents and children using printed images to tell family histories); and community (i.e., people using printed images to present an idealized self). The introduction of digital cameras into these households did not appear to change these practices; instead, it reinforced them. We discuss how considering relational objects in CSCW/HCI is useful for balancing the technologically determinist perspectives that are the basis of many prior studies of photography in these fields. In particular, we detail how considering the concept provides new perspectives on materiality, as well an alternative to the individualistic perspective, which underlies these communities' understanding of photography.
It's the Wild, Wild West: Lessons Learned From IRB Members' Risk Perceptions Toward Digital Research Data
Authors: Huh-Yoo Jina , Rader Emilee
Published: May 2020

Digital technology that is prevalent in people's everyday lives, including smart home devices, mobile apps and social media, increasingly lack regulations for how the user data can be collected, used or disseminated. The CSCW and the larger computing community continue to evaluate and understand the potential negative impacts of research involving digital technologies. As more research involves digital data, Institutional Review Boards (IRBs) take on the difficult task of evaluating and determining risks--likelihood of potential harms--from digital research. Learning more about IRBs' role in concretizing harm and its likelihood will help us critically examine the current approach to regulating digital research, and has implications for how researchers can reflect on their own data practices. We interviewed 22 U.S.-based IRB members and found that, for the interviewees, "being digital" added a risk. Being digital meant increasing possibilities of confidentiality breach, unintended collection of sensitive information, and unauthorized data reuse. Concurrently, interviewees found it difficult to pinpoint the direct harms that come out of those risks. The ambiguous, messy, and situated contexts of digital research data did not fit neatly into current human subjects research protection protocols. We discuss potential solutions for understanding risks and harms of digital technology and implications for the responsibilities of the CSCW and the larger computing community in conducting digital research.
Decolonizing Tactics as Collective Resilience: Identity Work of AAPI Communities on Reddit
Authors: Dosono Bryan , Semaan Bryan
Published: May 2020

Asian American and Pacific Islander (AAPI) communities use online platforms like Reddit to build capacity for resilience from white hegemony. We conduct interviews with 21 moderators of AAPI subreddits to understand how sociotechnical systems contour and contribute to the marginalization of online communities. We examine marginalization through the analytic framework of decolonization and uncover the threats and tactics that AAPI redditors encounter and employ to decolonize their collective identity. We find that moderators of AAPI subreddits develop collective resilience within their online communities by reclaiming space to confront brigade invasion, recording collective memory to circumvent systemic erasure, and revising cultural narratives to deconstruct colonial mentality. We describe how algorithmic configurations within sociotechnical systems reaffirm existing hegemonic values and discuss how users and designers of sociotechnical systems may work toward resisting white hegemony.
Computing Economic Equilibria Using Projection Methods
Authors: Miftakhova Alena , Schmedders Karl , Schumacher Malte
Published: May 2020

The analysis of dynamic economic models routinely leads to the mathematical problem of determining an unknown function for which no closed-form solution exists. Economists must then resort to methods of numerical approximation when analyzing such models. Among the computational methods that have been successfully applied in economics and finance, one set of techniques stands out due to its flexibility and robustness: projection methods. In this article, we describe the basic steps of these methods for several different applications, surveying many successful applications of projection methods to dynamic economic models. Importantly, we emphasize that the ever-increasing complexity and dimensionality of dynamic models have made the previously used simpler methods obsolete and the applications of projection methods all but mandatory. We closely examine the most recent endeavors in the literature on solving economic models with projection methods.
Oral Biologic Delivery: Advances Toward Oral Subunit, DNA, and mRNA Vaccines and the Potential for Mass Vaccination During Pandemics
Authors: Coffey Jacob William , Gaiha Gaurav Das , Traverso Giovanni
Published: May 2020

Oral vaccination enables pain-free and self-administrable vaccine delivery for rapid mass vaccination during pandemic outbreaks. Furthermore, it elicits systemic and mucosal immune responses. This protects against infection at mucosal surfaces, which may further enhance protection and minimize the spread of disease. The gastrointestinal (GI) tract presents a number of prospective mucosal inductive sites for vaccine targeting, including the oral cavity, stomach, and small intestine. However, currently available oral vaccines are effectively limited to live-attenuated and inactivated vaccines against enteric diseases. The GI tract poses a number of challenges,including degradative processes that digest biologics and mucosal barriers that limit their absorption. This review summarizes the approaches currently under development and future opportunities for oral vaccine delivery to established (intestinal) and relatively new (oral cavity, stomach) mucosal targets. Special consideration is given to recent advances in oral biologic delivery that offer promise as future platforms for the administration of oral vaccines.
Suspected Spontaneous Aqueous Humor Misdirection Syndrome in a Boston Terrier
Authors: Zibura Ashley E. , Davidson Michael G. , Westermeyer Hans D.
Published: May 2020

An eight-year-old female spayed Boston Terrier presented to the North Carolina Veterinary Hospital with glaucoma in the left eye (OS). Initial ophthalmic examination revealed moderate ocular hypertension, a diffusely and markedly shallow anterior chamber with anteriorly displaced iris and lens, vitreal prolapse, and a normal iridocorneal angle (ICA) morphology. The patient displayed a paradoxical response to topical latanoprost with an increase in intraocular pressure. These examination findings led to a putative diagnosis of spontaneous aqueous humor misdirection syndrome (AHMS). The patient was successfully managed with topical carbonic anhydrase inhibitors (CAIs) and apraclonidine for eight months until progressive ulcerative keratitis necessitated enucleation of the affected globe. Histopathology and high-field magnetic resonance imaging (MRI) of the enucleated globe did not identify an underlying cause for the glaucoma. This case suggests that AHMS should be considered in dogs presenting with a shallow anterior chamber, vitreal prolapse, increased intraocular pressure, and no other causes of glaucoma.
Spectral Clustering Algorithm Based on Improved Gaussian Kernel Function and Beetle Antennae Search with Damping Factor
Authors: Zhang Zhe , Liu Xiyu , Wang Lin
Published: May 2020

There are two problems in the traditional spectral clustering algorithm. Firstly, when it uses Gaussian kernel function to construct the similarity matrix, different scale parameters in Gaussian kernel function will lead to different results of the algorithm. Secondly, K-means algorithm is often used in the clustering stage of the spectral clustering algorithm. It needs to initialize the cluster center randomly, which will result in the instability of the results. In this paper, an improved spectral clustering algorithm is proposed to solve these two problems. In constructing a similarity matrix, we proposed an improved Gaussian kernel function, which is based on the distance information of some nearest neighbors and can adaptively select scale parameters. In the clustering stage, beetle antennae search algorithm with damping factor is proposed to complete the clustering to overcome the problem of instability of the clustering results. In the experiment, we use four artificial data sets and seven UCI data sets to verify the performance of our algorithm. In addition, four images in BSDS500 image data sets are segmented in this paper, and the results show that our algorithm is better than other comparison algorithms in image segmentation.
Fuzzy Second-Order Sliding Mode Control Design for a Two-Cell DC-DC Converter
Authors: Medhaffar Hanene , Derbel Nabil
Published: May 2020

This paper presents a fuzzy second-order sliding mode controller for a two-cell DC-DC converter. For this aim, a second-order sliding mode controller and a type-2 fuzzy system are combined to achieve an adequate control. For this reason, backgrounds on the type-2 fuzzy sets and on the second-order sliding mode control applied to discrete systems have been presented briefly. A proposed control algorithm is then presented combining these two robust approaches. The asymptotic stability of the overall controlled system has been ensured using the Lyapunov theory. The efficiency and the robustness of the proposed controller have been tested by simulations.