cssi/SciSciGPT-SciSciNet huggingface dataset:
Data Poisoning Attacks and Defenses to Crowdsourcing Systems

A key challenge of big data analytics is how to collect a large volume of (labeled) data. Crowdsourcing aims to address this challenge via aggregating and estimating high-quality data (e.g., sentiment label for text) from pervasive clients/users. Existing studies on crowdsourcing focus on designing new methods to improve the aggregated data quality from unreliable/noisy clients. However, the security aspects of such crowdsourcing systems remain under-explored to date. We aim to bridge this gap in this work. Specifically, we show that crowdsourcing is vulnerable to data poisoning attacks, in which malicious clients provide carefully crafted data to corrupt the aggregated data. We formulate our proposed data poisoning attacks as an optimization problem that maximizes the error of the aggregated data. Our evaluation results on one synthetic and two real-world benchmark datasets demonstrate that the proposed attacks can substantially increase the estimation errors of the aggregated data. We also propose two defenses to reduce the impact of malicious clients. Our empirical results show that the proposed defenses can substantially reduce the estimation errors of the data poisoning attacks.
qubit-ADAPT-VQE: An adaptive algorithm for constructing hardware-efficient ansatze on a quantum processor

The resources required to run a high-accuracy variational quantum eigensolver algorithm with a dynamically created ansatz are quantified and reduced significantly, easing the quantum simulation of many-body systems.
Connectedness properties and splittings of groups with isolated flats

We study CAT(0) groups and their splittings as graphs of groups. For one-ended CAT(0) groups with isolated flats we prove a theorem characterizing exactly when the visual boundary is locally connected. This characterization depends on whether the group has a certain type of splitting over a virtually abelian subgroup. In the locally connected case, we describe the boundary as a tree of metric spaces in the sense of Świątkowski. A significant tool used in the proofs of the above results is a general convex splitting theorem for arbitrary CAT(0) groups. If a CAT(0) group splits as a graph of groups with convex edge groups, then the vertex groups are also CAT(0) groups.
On the proliferation of support vectors in high dimensions

The support vector machine (SVM) is a well-established classification method whose name refers to the particular training examples, called support vectors, that determine the maximum margin separating hyperplane. The SVM classifier is known to enjoy good generalization properties when the number of support vectors is small compared to the number of training examples. However, recent research has shown that in sufficiently high-dimensional linear classification problems, the SVM can generalize well despite a proliferation of support vectors where all training examples are support vectors. In this paper, we identify new deterministic equivalences for this phenomenon of support vector proliferation, and use them to (1) substantially broaden the conditions under which the phenomenon occurs in high-dimensional settings, and (2) prove a nearly matching converse result.
Achievable Error Exponents of One-Way and Two-Way AWGN Channels

Achievable error exponents for the one-way with noisy feedback and two-way AWGN channels are derived for the transmission of a finite number of messages $M$ under almost sure (AS) and expected block (EXP) transmit power constraints. In the one-way setting under noisy AWGN feedback, under an AS power constraint, known linear and non-linear passive schemes are modified to incorporate AS constraints in the feedback link as well. In addition, a new active feedback scheme is presented in which the receiver feeds back the most likely pair of codewords, and the transmitter re-transmits which of these two was originally sent. This active feedback scheme outperforms one of the passive feedback schemes for all channel parameters; the linear scheme outperforms the others for low feedback noise variance. Under the EXP constraint, a known achievable error exponent for the transmission of two messages is generalized to any arbitrary but finite number of messages $M$ through the use of simplex codes and erasure decoding. In the two-way AWGN setting, each user has its own message to send in addition to (possibly) aiding in the transmission of feedback for the opposite direction. Two-way error exponent regions are defined and achievable error exponent regions are derived for the first time under both AS and EXP power constraints. For the presented achievability schemes, feedback or interaction leads to error exponent gains in one direction, possibly at the expense of a decrease in the error exponents attained in the other direction. The relationship between $M$ and $n$ supported by our achievable strategies is explored.
Low-Rank Generalized Linear Bandit Problems

In a low-rank linear bandit problem, the reward of an action (represented by a matrix of size $d_1 \times d_2$) is the inner product between the action and an unknown low-rank matrix $\Theta^*$. We propose an algorithm based on a novel combination of online-to-confidence-set conversion~\citep{abbasi2012online} and the exponentially weighted average forecaster constructed by a covering of low-rank matrices. In $T$ rounds, our algorithm achieves $\widetilde{O}((d_1+d_2)^{3/2}\sqrt{rT})$ regret that improves upon the standard linear bandit regret bound of $\widetilde{O}(d_1d_2\sqrt{T})$ when the rank of $\Theta^*$: $r \ll \min\{d_1,d_2\}$. We also extend our algorithmic approach to the generalized linear setting to get an algorithm which enjoys a similar bound under regularity conditions on the link function. To get around the computational intractability of covering based approaches, we propose an efficient algorithm by extending the "Explore-Subspace-Then-Refine" algorithm of~\citet{jun2019bilinear}. Our efficient algorithm achieves $\widetilde{O}((d_1+d_2)^{3/2}\sqrt{rT})$ regret under a mild condition on the action set $\mathcal{X}$ and the $r$-th singular value of $\Theta^*$. Our upper bounds match the conjectured lower bound of \cite{jun2019bilinear} for a subclass of low-rank linear bandit problems. Further, we show that existing lower bounds for the sparse linear bandit problem strongly suggest that our regret bounds are unimprovable. To complement our theoretical contributions, we also conduct experiments to demonstrate that our algorithm can greatly outperform the performance of the standard linear bandit approach when $\Theta^*$ is low-rank.
Kernel Interpolation for Scalable Online Gaussian Processes

Gaussian processes (GPs) provide a gold standard for performance in online settings, such as sample-efficient control and black box optimization, where we need to update a posterior distribution as we acquire data in a sequential fashion. However, updating a GP posterior to accommodate even a single new observation after having observed $n$ points incurs at least $O(n)$ computations in the exact setting. We show how to use structured kernel interpolation to efficiently recycle computations for constant-time $O(1)$ online updates with respect to the number of points $n$, while retaining exact inference. We demonstrate the promise of our approach in a range of online regression and classification settings, Bayesian optimization, and active sampling to reduce error in malaria incidence forecasting. Code is available at this https URL.
Uplink scheduling in CDMA packet-data systems

Uplink scheduling in wireless systems is gaining importance due to arising uplink intensive data services (ftp, image uploads etc.), which could be hampered by the currently in-built asymmetry in favor of the downlink. In this work, we propose and study algorithms for efficient uplink packet-data scheduling in a CDMA cell. The algorithms attempt to maximize system throughput under transmit power limitations on the mobiles assuming instantaneous knowledge of user queues and channels. However no channel statistics or traffic characterization is necessary. Apart from increasing throughput, the algorithms also improve fairness of service among users, hence reducing chances of buffer overflows for poorly located users.The major observation arising from our analysis is that it is advantageous on the uplink to schedule "strong" users one-at-a-time, and "weak" users in larger groups. This contrasts with the downlink where one-at-a-time transmission for all users has shown to be the preferred mode in much previous work. Based on the optimal schedules, we propose less complex and more practical approximate methods, both of which offer significant performance improvement compared to one-at-a-time transmission, and the widely acclaimed Proportional Fair (PF) algorithm, in simulations. When queue content cannot be fed back, we propose a simple modification of PF, Uplink PF (UPF), that offers similar improvement.
Bottom-induced contributions to Higgs plus jet at next-to-next-to-leading order

We present a next-to-next-to-leading order (NNLO) QCD calculation of the bottom-induced contributions to the production of a Higgs boson plus a jet, i.e. the process pp → H + j to $$ \mathcal{O}\left({y}_b^2{\alpha}_s^3\right) $$ . We work in the five-flavor scheme (5FS) in which the bottom quark mass is retained only in the coupling to the Higgs boson. Our calculation uses N-jettiness slicing to regulate infrared divergences, allowing for fully-differential predictions for collider observables. After extensively validating the methodology, we present results for the 13 TeV LHC. Our NNLO predictions show a marked improvement in the overall renormalization and factorization scale dependence, the latter of which proves to be particularly troublesome for 5FS calculations at lower orders. In addition, using the same methodology we present a NNLO computation of $$ b\overline{b} $$ → H. Our results are implemented into MCFM.
Simulations of Ash and Sand Impact on a Hypersonic Forebody

Hypersonic vehicles operate at extreme environments at narrow margins of safety. High-speed flight in the atmosphere when volcanic ash and other meteorological particles are present can cause damag...
Blockchain-empowered Newsvendor optimization

Abstract Technology has been widely adopted as a backbone for supply chain management, especially in the context of retailing. For example, Blockchain Technology (BCT) has been embraced as a disruptive technology, though it is still in a nascent stage. This study examines the technology adoption for Newsvendor model (a.k.a Newsboy), as exemplified by a blockchain system. It aims to shed light on how BCT adoption impacts the optimal ordering decisions and the corresponding optimal profit. Importantly, we investigate the optimal adoption of technology for profit optimization while considering the adoption cost. As a result, we visualize how technology adoption shifts the curve. For some selected demand types (e.g., Uniform and Normal distributions) and the Cobb-Douglas cost function, we derive closed-form expressions for the optimal decisions, based on which some useful insights have been developed. Although high adoption of BCT leads to higher demand and lower ordering cost, some counter-intuitive examples have been devised to reveal that the increase in adoption degree might lower the optimal order quantity and it is not always profitable to adopt a higher BCT even if there is no adoption cost. Finally, a sequence of numerical studies complements our analytical results with rich and useful insights.
Explainable AI for ML jet taggers using expert variables and layerwise relevance propagation

A framework is presented to extract and understand decision-making information from a deep neural network (DNN) classifier of jet substructure tagging techniques. The general method studied is to provide expert variables that augment inputs (“eXpert AUGmented” variables, or XAUG variables), then apply layerwise relevance propagation (LRP) to networks both with and without XAUG variables. The XAUG variables are concatenated with the intermediate layers after network-specific operations (such as convolution or recurrence), and used in the final layers of the network. The results of comparing networks with and without the addition of XAUG variables show that XAUG variables can be used to interpret classifier behavior, increase discrimination ability when combined with low-level features, and in some cases capture the behavior of the classifier completely. The LRP technique can be used to find relevant information the network is using, and when combined with the XAUG variables, can be used to rank features, allowing one to find a reduced set of features that capture part of the network performance. In the studies presented, adding XAUG variables to low-level DNNs increased the efficiency of classifiers by as much as 30-40%. In addition to performance improvements, an approach to quantify numerical uncertainties in the training of these DNNs is presented.
The multiplayer Colonel Blotto game

Abstract We initiate the study of the natural multiplayer generalization of the classic continuous Colonel Blotto game. The two-player Blotto game, introduced by Borel (1953) as a model of resource competition across n simultaneous fronts, has been studied extensively for a century and has seen numerous applications throughout the social sciences. Our work defines the multiplayer Colonel Blotto game and derives Nash equilibria for various settings of k (number of players) and n. We also introduce a “Boolean” version of Blotto that becomes interesting in the multiplayer setting. The main technical difficulty of our work, as in the two-player theoretical literature, is the challenge of coupling various marginal distributions into a joint distribution satisfying a strict sum constraint. In contrast to previous works in the continuous setting, we derive our couplings algorithmically in the form of efficient sampling algorithms.
Folate Deficiency in an Urban Safety Net Population.

Abstract Purpose Since mandatory fortification of grain products with folic acid in the United States in 1998, folate deficiency has become rare. Some have suggested that serum folate levels should be tested rarely in countries with mandatory folic acid fortification, given low rates of deficiency, high cost per deficiency diagnosis, and low rates of supplementation for those diagnosed as deficient. Given persistent racial, ethnic, and socioeconomic disparities in folate deficiency, these suggestions may not apply to all populations. We examine the rate at which serum testing detected folate deficiency in an urban safety net hospital and the characteristics of folate-deficient patients. Methods We reviewed the charts of all inpatients and emergency department patients with low serum folate results at a safety net hospital in Boston in 2018. We collected data concerning demographics, social determinants of health, clinical factors, and whether folate supplementation was prescribed. Finally, we performed a cost analysis. Results Of 1368 patients tested, 76 (5.5%) met criteria for folate deficiency. Overall, 86.8% of these patients were anemic, and 17.1% had macrocytic anemia; 42% were diagnosed with malnutrition. Common social determinants in folate-deficient patients included birth outside of the United States, homelessness, and alcohol use disorder. Of folate-deficient patients, 88% were newly prescribed folic acid supplementation at discharge. The estimated charge per deficient test was $1278. Conclusion Compared with a nearby institution, serum folate testing at our safety net hospital detected deficiency at a higher rate, incurred a lower charge per deficient test, and was more likely to impact management.
Bioverse: A Simulation Framework to Assess the Statistical Power of Future Biosignature Surveys

Next-generation space observatories will conduct the first systematic surveys of terrestrial exoplanet atmospheres and search for evidence of life beyond Earth. While in-depth observations of the nearest habitable worlds may yield enticing results, there are fundamental questions about planetary habitability and evolution which can only be answered through population-level studies of dozens to hundreds of terrestrial planets. To determine the requirements for next-generation observatories to address these questions, we have developed Bioverse. Bioverse combines existing knowledge of exoplanet statistics with a survey simulation and hypothesis testing framework to determine whether proposed space-based direct imaging and transit spectroscopy surveys will be capable of detecting various hypothetical statistical relationships between the properties of terrestrial exoplanets. Following a description of the code, we apply Bioverse to determine whether an ambitious direct imaging or transit survey would be able to determine the extent of the circumstellar habitable zone and study the evolution of Earth-like planets. Given recent evidence that Earth-sized habitable zone planets are likely much rarer than previously believed (Pascucci et al. 2019), we find that space missions with large search volumes will be necessary to study the population of terrestrial and habitable worlds. Moving forward, Bioverse provides a methodology for performing trade studies of future observatory concepts to maximize their ability to address population-level questions, including and beyond the specific examples explored here.
Transcription factor NF-κB unravels nucleosomes

Abstract NF-κB is a transcription factor responsible for activating hundreds of genes in mammalian organisms. To accomplish its function, NF-κB must interact with DNA occupied by nucleosomes, but how this interaction occurs is unclear. Here we used Atomic Force Microscopy to characterize complexes of NF-κB with nucleosomes assembled on different DNA templates. The assembly of NF-κB-nucleosome complexes leads to a substantial decrease of DNA wrapping efficiency from 149 ± 2 bp (SEM) for the control nucleosome sample to 135 ± 3 bp for complexes of nucleosomes with NF-κB. Mapping of the nucleosomes did not reveal displacement of under-wrapped nucleosomes from their original position, suggesting that unravelling involves dissociation of one or both flanks of the nucleosomes. Binding of NF-κB to the core was identified by nucleosome core volume measurements. We discovered two binding modes of NF-κB associated with nucleosome unravelling - NF-κB bound to the nucleosome core and to the DNA flanks. From these findings we propose two models explaining the interaction of NF-κB with the nucleosome complex. The partial unravelling of nucleosomes by NF-κB makes the DNA segment at the edge of the nucleosome core accessible, facilitating the transcription process. We speculate that NF-κB can function as a pioneer factor, enhancing its ability to facilitate rapid transcriptional response to cell stress.
Identifying Helpful Sentences in Product Reviews.

In recent years online shopping has gained momentum and became an important venue for customers wishing to save time and simplify their shopping process. A key advantage of shopping online is the ability to read what other customers are saying about products of interest. In this work, we aim to maintain this advantage in situations where extreme brevity is needed, for example, when shopping by voice. We suggest a novel task of extracting a single representative helpful sentence from a set of reviews for a given product. The selected sentence should meet two conditions: first, it should be helpful for a purchase decision and second, the opinion it expresses should be supported by multiple reviewers. This task is closely related to the task of Multi Document Summarization in the product reviews domain but differs in its objective and its level of conciseness. We collect a dataset in English of sentence helpfulness scores via crowd-sourcing and demonstrate its reliability despite the inherent subjectivity involved. Next, we describe a complete model that extracts representative helpful sentences with positive and negative sentiment towards the product and demonstrate that it outperforms several baselines.
Evolution of human respiratory virus epidemics

Background: Pathogens are often assumed to evolve towards reduced virulence, but counterexamples abound. Faced with a new pathogen, such as SARS-CoV-2, it is crucial to be able to forecast the case fatality rate (CFR) and the overall disease burden. Considerable effort has been invested towards developing a mathematical framework for predicting virulence evolution. Although many approaches accurately recapitulate complex outcomes, most rely on an assumed trade-off between CFR and infection rate. It is often impractical to empirically validate this constraint for human pathogens. Methods: A compartment model with parameters tuning the degree to which symptomatic individuals are isolated and the duration of immunity is constructed and evaluated at both short timescales and at equilibrium. Results: We reveal kinetic constraints whereby variation of multiple parameters in concert leads to decreased CFR and increased pathogen fitness, whereas independent variation of the parameters decreases pathogen fitness. Smallpox, SARS-CoV-2, and influenza are analyzed as diverse representatives of human respiratory viruses. We show that highly virulent viruses, such as smallpox, are often constrained by the host behavior, whereas moderately virulent viruses, such as SARS-CoV-2, appear to be typically constrained by the relationship between the duration of immunity and CFR. Conclusions: Evolution of human respiratory epidemics appears to be often kinetically constrained and a reduction in CFR should not be assumed. These results agree with previous work demonstrating an increase in virulence for smallpox and further predict that SARS-CoV-2 is likely to continue presenting a substantial disease burden. Herd immunity against SARS-CoV-2 and viruses with similar life history traits might be unachievable without vaccination. However, partial isolation of symptomatic individuals can have a major effect on the epidemic dynamics not only by reducing the number of fatalities in the short term but also by changing the evolutionary trajectory of moderate CFR viruses towards reduced CFR.
Lifting images of standard representations of symmetric groups

We investigate closed subgroups $$G \subseteq \mathrm {Sp}_{2g}(\mathbb {Z}_2)$$ whose modulo-2 images coincide with the image $$\mathfrak {S}_{2g + 1} \subseteq \mathrm {Sp}_{2g}(\mathbb {F}_2)$$ of $$S_{2g + 1}$$ or the image $$\mathfrak {S}_{2g + 2} \subseteq \mathrm {Sp}_{2g}(\mathbb {F}_2)$$ of $$S_{2g + 2}$$ under the standard representation. We show that when $$g \ge 2$$ , the only closed subgroup $$G \subseteq \mathrm {Sp}_{2g}(\mathbb {Z}_2)$$ surjecting onto $$\mathfrak {S}_{2g + 2}$$ is its full inverse image in $$\mathrm {Sp}_{2g}(\mathbb {Z}_2)$$ , while all subgroups $$G \subseteq \mathrm {Sp}_{2g}(\mathbb {Z}_2)$$ surjecting onto $$\mathfrak {S}_{2g + 1}$$ are open and contain the level-8 principal congruence subgroup of $$\mathrm {Sp}_{2g}(\mathbb {Z}_2)$$ . As an immediate application, we are able to strengthen a result of Zarhin on 2-adic Galois representations associated to hyperelliptic curves. We also prove an elementary corollary concerning even-degree polynomials with full Galois group.
What Makes Quadruply Lensed Quasars Quadruple

Among known strongly lensed quasar systems, ~25% have gravitational potentials sufficiently flat (and sources sufficiently well aligned) to produce four images rather than two. The projected flattening of the lensing galaxy and tides from neighboring galaxies both contribute to the potential's quadrupole. Witt's hyperbola and Wynne's ellipse permit determination of the overall quadrupole from the positions of the quasar images. The position of the lensing galaxy resolves the distinct contributions of intrinsic ellipticity and tidal shear to that quadrupole. Among 31 quadruply lensed quasars systems with statistically significant decompositions, 15 are either reliably ($2\sigma$) or provisionally ($1\sigma$) shear-dominated and 11 are either reliably or provisionally ellipticity-dominated. For the remaining 8, the two effects make roughly equal contributions to the combined cross section (newly derived here) for quadruple lensing. This observational result is strongly at variance with the ellipticity-dominated forecast of Oguri & Marshall (2010).
Identification of Microprotein-Protein Interactions via APEX Tagging

Microproteins are peptides and small proteins encoded by small open reading frames (smORFs). Newer technologies have led to the recent discovery of hundreds to thousands of new microproteins. The biological functions of a few microproteins have been elucidated, and these microproteins have fundamental roles in biology ranging from limb development to muscle function, highlighting the value of characterizing these molecules. The identification of microprotein–protein interactions (MPIs) has proven to be a successful approach to the functional characterization of these genes; however, traditional immunoprecipitation methods result in the enrichment of nonspecific interactions for microproteins. Here, we test and apply an in situ proximity tagging method that relies on an engineered ascorbate peroxidase 2 (APEX) to elucidate MPIs. The results demonstrate that APEX tagging is superior to traditional immunoprecipitation methods for microproteins. Furthermore, the application of APEX tagging to an uncharacteriz...
Upper bound on the equilibrium concentration of atomic H in solid H2

A phenomenological rate process theory has been developed for the production, storage and recombination of atomic H free radicals in a tritium-impregnated solid H2 at temperatures in the range of about 0.1 to 4 K. In this paper it is shown that the theory requires a stringent upper bound on the equilibrium concentration of trapped atomic H, namely that it cannot exceed about 0.125%, even if the temperature is reduced to an arbitrary low value and a very strong magnetic field is applied to the tritium-impregnated H2 solid.
A note on identifiability conditions in confirmatory factor analysis

Abstract Recently, Chen, Li and Zhang established conditions characterizing asymptotic identifiability of latent factors in confirmatory factor analysis. We give an elementary proof showing that a similar characterization holds non-asymptotically, and prove a related result for identifiability of factor loadings.
Overbooking with Bounded Loss

We study a classical problem in revenue management: quantity-based single-resource revenue management with no-shows. In this problem, a firm observes a sequence of T customers requesting a service. Each arrival is drawn independently from a known distribution of k different types, and the firm needs to decide irrevocably whether to accept or reject requests in an online fashion. The firm has a capacity of resources B, and wants to maximize its profit. Each accepted service request yields a type-dependent revenue and has a type-dependent probability of requiring a resource once all arrivals have occurred (or, be a no-show). If the number of accepted arrivals that require a resource at the end of the horizon is greater than B, the firm needs to pay a fixed compensation for each service request that it cannot fulfill. With a clairvoyant, that knows all arrivals ahead of time, as a benchmark, we provide an algorithm with a uniform additive loss bound, i.e., its expected loss is independent of B and T. This improves upon prior works achieving $Omega(\sqrtT )$ guarantees.
Photoreceptor Compartment-Specific TULP1 Interactomes

Photoreceptors are highly compartmentalized cells with large amounts of proteins synthesized in the inner segment (IS) and transported to the outer segment (OS) and synaptic terminal. Tulp1 is a photoreceptor-specific protein localized to the IS and synapse. In the absence of Tulp1, several OS-specific proteins are mislocalized and synaptic vesicle recycling is impaired. To better understand the involvement of Tulp1 in protein trafficking, our approach in the current study was to physically isolate Tulp1-containing photoreceptor compartments by serial tangential sectioning of retinas and to identify compartment-specific Tulp1 binding partners by immunoprecipitation followed by liquid chromatography tandem mass spectrometry. Our results indicate that Tulp1 has two distinct interactomes. We report the identification of: (1) an IS-specific interaction between Tulp1 and the motor protein Kinesin family member 3a (Kif3a), (2) a synaptic-specific interaction between Tulp1 and the scaffold protein Ribeye, and (3) an interaction between Tulp1 and the cytoskeletal protein microtubule-associated protein 1B (MAP1B) in both compartments. Immunolocalization studies in the wild-type retina indicate that Tulp1 and its binding partners co-localize to their respective compartments. Our observations are compatible with Tulp1 functioning in protein trafficking in multiple photoreceptor compartments, likely as an adapter molecule linking vesicles to molecular motors and the cytoskeletal scaffold.
Millimeter-Scale Chip-Based Supercontinuum Generation for Optical Coherence Tomography

We demonstrate a supercontinuum light source for OCT imaging in a compact 1 mm2 Si 3 N 4 chip. We achieve 105 dB sensitivity and a 6-dB sensitivity roll-off at 1.81 mm with only 300 µW incident power.
Retention and deformation of the blue phases in liquid crystalline elastomers

The blue phases are observed in highly chiral liquid crystalline compositions that nascently organize into a three-dimensional, crystalline nanostructure. The periodicity of the unit cell lattice spacing is on the order of the wavelength of visible light and accordingly, the blue phases exhibit a selective reflection as a photonic crystal. Here, we detail the synthesis of liquid crystalline elastomers that retain blue phase I, blue phase II, and blue phase III. The mechanical properties and optical reconfiguration via deformation of retained blue phases are contrasted to the cholesteric phase in fully solid elastomers with glass transition temperatures below room temperature. Mechanical deformation and chemical swelling of the lightly crosslinked polymer networks induces lattice asymmetry in the blue phase evident in the tuning of the selective reflection. The lattice periodicity of the blue phase elastomer is minimally affected by temperature. The oblique lattice planes of the blue phase tilt and red-shift in response to mechanical deformation. The retention of the blue phases in fully solid, elastomeric films could enable functional implementations in photonics, sensing, and energy applications. Permanently retaining liquid crystalline blue phases in a solid matrix warrants many prospective applications in photonics. Schlafmann and White are able to make a blue phase rubber that retains a crystalline structure upon deformation and responds with angle-dependent color changes.
The impact of a community based rehabilitation program in Afghanistan: a longitudinal analysis using propensity score matching and difference in difference analysis.

BACKGROUND The 2006 United Nations Convention on the Rights of Persons with Disabilities states that the achievement of equal rights, empowerment and social inclusion of people with disabilities requires comprehensive rehabilitation services encompassing all components of the World Health Organization Community based rehabilitation (CBR) matrix: health, education, livelihood, social and empowerment. CBR programs specifically aim to deliver such comprehensive interventions. In the present study, we investigate the impact of a CBR program in Afghanistan on all these components. METHODS We enrolled 1861 newly recruited CBR participants with disabilities in the study, from 169 villages between July 2012 and December 2013 as well as 1132 controls with disabilities randomly selected through a two-stage process within 6000 households from 100 villages in the same provinces but outside the catchment area of the CBR program. We interviewed them again after one (midline) and two (end-line) years in the study. Using propensity score matching and difference in difference analysis, we estimated the impact of the CBR on outcomes of interest, namely mobility, activities of daily living, communication, participation in social and community life, emotional well-being and employment. RESULTS Three years on average into the CBR program, participants showed a significant and close to medium effect size reduction in emotional (Cohen's d = - 0.48, 95%CI[- 0.58--0.38]), and social participation challenges (Cohen's d = - 0.45, 95%CI[- 0.53-- 0.36]); small to medium effect size reduction in unemployment (Cohen's d = - 0.21, 95%CI[- 0.33--0.10]), activities of daily living (Cohen's d = - 0.26, 95%CI[- 0.35--0.18]), mobility (Cohen's d = - 0.36, 95%CI[- 0.44--.29]) and communication challenges (Cohen's d = - 0.38, 95%CI[- 0.46--0.3]). CONCLUSIONS Our study indicates that a CBR program may provide positive rehabilitation outcomes for persons with disabilities even in a conflict context, and improve overall well-being of all participants with disabilities, whatever their impairment, individual characteristics and the CBR matrix components considered. TRIAL REGISTRATION ISRCTN, ISRCTN50214054 . Registered August 5th 2020 - retrospectively registered.
When does forecasting GAAP earnings entail unreasonable effort

Abstract SEC rules require managers to reconcile their non-GAAP earnings forecasts with the most directly comparable GAAP forecasts unless doing so would entail ‘unreasonable effort.’ A significant number of managers rely on the unreasonable efforts exception to justify the omission of comparable GAAP forecasts. We analyze firms that rely on the unreasonable efforts exception and find that their non-GAAP earnings forecasts are more likely to exclude significant recurring expenses that are not excluded by analysts. Our results suggest that almost a third of managers exploit the unreasonable efforts exception to exclude significant recurring expenses from their earnings guidance.
Fabrication of fiber-reinforced polymer ceramic composites by wet electrospinning

Abstract We propose a novel approach of wet electrospinning to yield fiber-reinforced polymer ceramic composites, where a reactive ceramic precursor gel is used as a collector. We illustrate our approach by generating polyethylene oxide (PEO) fibers in a potassium silicate gel; the gel is later activated using metakaolin to yield a ceramic-0.5 wt% PEO fiber composite. An increase of 29% and 22% is recorded for the fabricated polymer ceramic composites in terms of indentation modulus and indentation hardness respectively. Our initial findings demonstrate the process viability and might lead to a potentially scalable manufacturing approach for fiber-reinforced polymer ceramic composites.
Young firms, old capital

Abstract Across a broad range of equipment types and industries, we document a pattern of local capital reallocation from older firms to younger firms. Start-ups purchase a disproportionate share of old physical capital previously owned by more mature firms. The evidence is consistent with financial constraints driving differential demand for vintage capital. The local supply of used capital influences start-up entry, job creation, investment choices, and growth, particularly when capital is immobile. Meanwhile, as suppliers of used capital, incumbents accelerate capital replacement in the presence of younger firms. The evidence suggests previously undocumented benefits to co-location between old and young firms.
How Do Restrictions on Advertising Affect Consumer Search

Advertising is often criticized for presenting only partial or selective information about products. This criticism is particularly pronounced for health products, where large asymmetries in inform...
Local Temperature Scaling for Probability Calibration

For semantic segmentation, label probabilities are often uncalibrated as they are typically only the by-product of a segmentation task. Intersection over Union (IoU) and Dice score are often used as criteria for segmentation success, while metrics related to label probabilities are rarely explored. On the other hand, probability calibration approaches have been studied, which aim at matching probability outputs with experimentally observed errors, but they mainly focus on classification tasks, not on semantic segmentation. Thus, we propose a learning-based calibration method that focuses on multi-label semantic segmentation. Specifically, we adopt a tree-like convolution neural network to predict local temperature values for probability calibration. One advantage of our approach is that it does not change prediction accuracy, hence allowing for calibration as a post-processing step. Experiments on the COCO and LPBA40 datasets demonstrate improved calibration performance over different metrics. We also demonstrate the performance of our method for multi-atlas brain segmentation from magnetic resonance images.
Occupational Licensing and Accountant Quality: Evidence from the 150-Hour Rule

I examine the effects of occupational licensing on the quality of Certified Public Accountants (CPAs). I exploit the staggered adoption of the 150-hour rule, which increases the educational requirements for a CPA license. The analysis shows that the rule decreases the number of entrants into the profession, reducing both low- and high-quality candidates. Labor market proxies for quality find no difference between 150-hour rule CPAs and the rest. Moreover, rule CPAs exit public accounting at similar rates and have comparable writing quality to their non-rule counterparts. Overall, these findings are consistent with the theoretical argument that increases in licensing requirements restrict the supply of entrants and do little to improve quality in the labor market.
Deed Types, House Prices and Mortgage Interest Rates

∗∗∗ When houses are sold they come with a deed attached that spells out the legal guarantees on good title. Some deeds give clues about the characteristics of the seller or the house. Using a 37,043-observation house price hedonic with a Bayesian spatial error model, we find the type of deed attached to a housing sale can have a dramatic correlation with the sale price. Ten deed types command a discount, and one commands a premium relative to warranty deeds. Mortgage rates for sheriff’s deeds and foreclosure deeds are lower than for warranty deeds, indicating more sophisticated buyers. A deed is a written document that conveys a real asset from one party to another. A deed sometimes contains guarantees of good title, freedom from encumbrances and protection from competing claims against the property; other deeds make no such guarantees. The circumstances surrounding the sale determine the type of deed a property will sell with. Investigating the relation between deed type and house price is interesting for several reasons. A universal criticism of house price hedonics is that they fail to control for the condition of the house. The deed type often imparts information about the condition of the house at the time of sale, abating this source of omitted variable bias. Property tax assessors care about deed type if the use of this information yields a better prediction of the underlying structural value of the house than even the sale price does. General warranty deeds have the most robust guarantees of clear title. When a property is transferred with a general warranty deed, the seller is guaranteeing that he holds clear title to the property, and the clear title guarantee extends back to the origin of the property. Discounts and premiums for houses sold with certain alternative deed types, relative to the general warranty deed sales, suggest interesting stories, such as seller motivation for corporation deed sales. Additionally, the discounts associated with foreclosure and sheriff’s deeds may indicate suboptimal mechanism design for foreclosure auctions and sheriff’s sales.
Eccentric millisecond pulsars by resonant convection

Eccentric millisecond pulsars (eMSPs) with white dwarf companions exhibit orbital eccentricities orders of magnitude larger than predicted by turbulent convection in the white dwarfs' red giant progenitors. The orbital periods of eMSPs cluster around $P=20-30$ d, remarkably close to the red giant convective eddy turnover time $t_{\rm eddy}$. We propose that the anomalously large eccentricities are resonantly driven by convective flows somehow made coherent when the turnover time matches the tidally locked red giant's spin period, which is also the tidal forcing period. Numerical simulations of rotating red giants and magnetic field studies of stars show some evidence for especially ordered flow patterns when the convective Rossby number $P/t_{\rm eddy}$ is of order unity. We show that resonant convection boosts eccentricities by a factor of $(t_{\rm nuc}/P)^{1/2}\approx 3\times 10^3$ over the random-walk values that characterize conventional MSPs, in good agreement with observations ($t_{\rm nuc}$ is the giant's nuclear burning time-scale). We also show how variations in the eddy turnover time arising from red giant metallicity variations can reproduce the observed effective width of the resonance, $\Delta P/P\approx 0.4$.
Effect of Interfacial characteristics of metal clad polymeric substrates on electrical high frequency interconnection performance

Etched metallic conductor lines on metal clad polymeric substrates are used for electronic component interconnections. Significant signal losses are observed for microstrip conductor lines used for interconnecting high frequency devices. At these frequencies, the electronic signal travels closer to the metal-polymer interface due to the skin effect. Copper-teflon interfaces were characterized by scanning electron microscopy (SEM) and Auger electron spectroscopy (AES) to determine the interfacial properties. Data relating roughness of the copper film to signal losses was compared to theory. Films used to enhance adhesion are found, to contribute to these losses.
Overinterpretation reveals image classification model pathologies

Image classifiers are typically scored on their test set accuracy, but high accuracy can mask a subtle type of model failure. We find that high scoring convolutional neural networks (CNNs) on popular benchmarks exhibit troubling pathologies that allow them to display high accuracy even in the absence of semantically salient features. When a model provides a high-confidence decision without salient supporting input features, we say the classifier has overinterpreted its input, finding too much class-evidence in patterns that appear nonsensical to humans. Here, we demonstrate that neural networks trained on CIFAR-10 and ImageNet suffer from overinterpretation, and we find models on CIFAR-10 make confident predictions even when 95% of input images are masked and humans cannot discern salient features in the remaining pixel-subsets. Although these patterns portend potential model fragility in real-world deployment, they are in fact valid statistical patterns of the benchmark that alone suffice to attain high test accuracy. Unlike adversarial examples, overinterpretation relies upon unmodified image pixels. We find ensembling and input dropout can each help mitigate overinterpretation.
Does enforcing fairness mitigate biases caused by subpopulation shift

Many instances of algorithmic bias are caused by subpopulation shifts. For example, ML models often perform worse on demographic groups that are underrepresented in the training data. In this paper, we study whether enforcing algorithmic fairness during training improves the performance of the trained model in the \emph{target domain}. On one hand, we conceive scenarios in which enforcing fairness does not improve performance in the target domain. In fact, it may even harm performance. On the other hand, we derive necessary and sufficient conditions under which enforcing algorithmic fairness leads to the Bayes model in the target domain. We also illustrate the practical implications of our theoretical results in simulations and on real data.
On contact type hypersurfaces in 4-space

We consider constraints on the topology of closed 3-manifolds that can arise as hypersurfaces of contact type in standard symplectic $${\mathbb {R}}^4$$ . Using an obstruction derived from Heegaard Floer homology we prove that no Brieskorn homology sphere admits a contact type embedding in $${\mathbb {R}}^4$$ , a result that has bearing on conjectures of Gompf and Kollar. This implies in particular that no rationally convex domain in $${\mathbb {C}}^2$$ has boundary diffeomorphic to a Brieskorn sphere. We also give infinitely many examples of contact 3-manifolds that bound Stein domains in $${\mathbb {C}}^2$$ but not domains that are symplectically convex with respect to the standard symplectic structure; in particular we find Stein domains in $${\mathbb {C}}^2$$ that cannot be made Weinstein with respect to the ambient symplectic structure while preserving the contact structure on their boundaries. Finally, we observe that any strictly pseudoconvex, polynomially convex domain in $${\mathbb {C}}^2$$ having rational homology sphere boundary is diffeomorphic to the standard 4-ball.
Simpler (Classical) and Faster (Quantum) Algorithms for Gibbs Partition Functions

We give classical and quantum algorithms for approximating partition functions of classical Hamiltonians at a given temperature. Specifically, we modify the classical algorithm of Stefankovic, Vempala and Vigoda (J. ACM, 56(3), 2009) to improve its sample complexity; and we quantize this new algorithm, improving upon the previously best quantum algorithm for computing Gibbs partition functions due to Harrow and Wei (SODA 2020).The conventional approach to estimate partition functions requires approximating the mean of Gibbs distributions at nearby inverse temperatures that satisfy certain properties; this set of temperatures is called a cooling schedule. The length of the cooling schedule directly affects the complexity of the algorithm. Combining our improved version of the algorithm of Stefankovic, Vempala and Vigoda with the paired-product estimator of Huber (Ann. Appl. Probab., 25(2), 2015), our new quantum algorithm uses a shorter cooling schedule than previously known. This length matches the optimal length conjectured by Stefankovic, Vempala and Vigoda. The quantum algorithm also achieves a quadratic advantage in the number of required quantum samples compared to the number of random samples drawn by the best classical algorithm, and its computational complexity has quadratically better dependence on the spectral gap of the Markov chains used to produce the quantum samples.
Proceedings before the Cour de Cassation

This chapter describes the territorial competence of the Cour de Cassation (9.01–9.02), decisions subject to review (9.03–9.05), waiver of the right to review (9.06), grounds for review (9.07–9.12), the prohibition against raising new matter (9.13), private parties before the Cour de Cassation (9.14), the role of the ministere public (9.15), the method and time for filing a pourvoi (9.16–9.17), the effects of pourvoi on execution (9.18), procedures before the Cour de Cassation (9.19–9.22), preparation of the decision (9.23), effects of the decision (9.24), procedure on remand (9.25), proceedings on a second pourvoi (9.26), cases in which there is no remand (9.27), and the role of the Cour de Cassation in the development of the law (9.28).
Nonlinear optics as a probe of the mode volume of ultra-high-Q toroid microcavities

We have investigated both numerically and experimentally the mode volume of ultra-high-Q toroid micro-cavities on a chip. Reduction of the mode volume with increasing confinement is predicted numerically, and experimentally observed by a lowering of the threshold for stimulated Raman scattering.
A Solid-State Maxwell Demon

A laboratory-testable, solid-state Maxwell demon is proposed that utilizes the electric field energy of an open-gap p-n junction. Numerical results from a commercial semiconductor device simulator (Silvaco International–Atlas) verify primary results from a 1-D analytic model. Present day fabrication techniques appear adequate for laboratory tests of principle.