cssi/SciSciGPT-SciSciNet huggingface dataset:
Asymmetric Total Synthesis of an Important 3-(Hydroxymethyl)carbacephalosporin

Carbacephalosporins have gained much attention as important antibacterial agents. Recently, 3-(hydroxymethyl)carbacephalosporins have been linked to quinolones for the production of multifunctional antibiotics. A short, practical asymmetric total synthesis of carbacephalosporin 3, suitable for conjugating to other chemical moieties, is reported. The synthesis was achieved by Mitsunobu cyclization of dipeptide 12, prepared from l-erythro-anti-β-hydroxy-α-amino acid 11, and subsequent Horner−Wadsworth−Emmons cyclization of ketone 16.
Synthesis of polyazacyclophane‐intercalator conjugates for combinatorial chemistry and RNA interaction studies

Anthraquinone and pyrene intercalators were conjugated to different positions of several polyaza-pyridinocyclophanes by various linkers to provide thirteen new polyazacyclophane-intercalator conjugates 1–13. These resulting conjugates contain two or three constrained secondary nitrogen atoms on the ring, which may serve as nucleophilic, coordinating or hydrogen-bonding sites for combinatorial, RNA interaction and coordination studies.
Concentration dependent chromatin states induced by the bicoid morphogen gradient

In Drosophila, graded expression of the maternal transcription factor Bicoid (Bcd) provides positional information to activate target genes at different positions along the anterior-posterior axis. We have measured the genome-wide binding profile of Bcd using ChIP-seq in embryos expressing single, uniform levels of Bcd protein, and grouped Bcd-bound targets into four classes based on occupancy at different concentrations. By measuring the biochemical affinity of target enhancers in these classes in vitro and genome-wide chromatin accessibility by ATAC-seq, we found that the occupancy of target sequences by Bcd is not primarily determined by Bcd binding sites, but by chromatin context. Bcd drives an open chromatin state at a subset of its targets. Our data support a model where Bcd influences chromatin structure to gain access to concentration-sensitive targets at high concentrations, while concentration-insensitive targets are found in more accessible chromatin and are bound at low concentrations. This may be a common property of developmental transcription factors that must gain early access to their target enhancers while the chromatin state of the genome is being remodeled during large-scale transitions in the gene regulatory landscape.
Tropical and Midlatitude Impact on Seasonal Polar Predictability in the Community Earth System Model

AbstractThe impact on seasonal polar predictability from improved tropical and midlatitude forecasts is explored using a perfect-model experiment and applying a nudging approach in a GCM. We run th...
Hydrothermal syntheses of layered uranium oxyfluorides: illustrations of dimensional reduction.

Two new U(VI) oxyfluorides (C5H6N)U2O4F5 (AU2-4) and (C3H5N2)U2O4F5·1.75H2O (AU2-5) have been prepared through explorations of the UO2(C2H3O2)2/HF/pyridine and UO3/HF/pyrazole systems at 180 °C for...
Adventitious viruses persistently infect three commonly used mosquito cell lines.

Abstract Mosquito cell lines have been used extensively in research to isolate and propagate arthropod-borne viruses and understand virus-vector interactions. Despite their utility as an in vitro tool, these cell lines are poorly defined and may harbor insect-specific viruses. Accordingly, we screened four commonly-used mosquito cell lines, C6/36 and U4.4 cells from Aedes albopictus, Aag2 cells from Aedes aegypti, and Hsu cells from Culex quinquefasciatus, for the presence of adventitious (i.e. exogenous) viruses. All four cell lines stained positive for double-stranded RNA, indicative of RNA virus replication. We subsequently identified viruses infecting Aag2, U4.4 and Hsu cell lines using untargeted next-generation sequencing, but not C6/36 cells. PCR confirmation revealed that these sequences stem from active viral replication and/or integration into the cellular genome. Our results show that these commonly-used mosquito cell lines are persistently-infected with several viruses. This finding may be critical to interpreting data generated in these systems.
Synthesis of 2,4-Diamino-5,6,7,8,9,10-hexahydro-5,9-methanopyrimido[4,5-b]azocine

We have initiated a program aimed at the synthesis of derivatives of 2,4-diamino-5,6,7,8,9,10-hexahydro-5,9-methanopyrimido[4,5-b]azocine (3) as potential selective inhibitors of Pneumocystis carin...
Stereoselective aldol additions of titanium enolates of N-acetyl-4-isopropyl-thiazolidinethione

Abstract The addition of chlorotitanium enolates of N-acetyl isopropyl thiazolidine-2-thione to aldehydes was investigated. The stereoselectivity of the aldol products was controlled by the number of equivalents of base added. The syn aldol product was obtained preferentially when 2 equiv of Lewis acid and 1 equiv of base were employed. The anti aldol product was obtained preferentially when 1 equiv of Lewis acid and 2 equiv of base were employed for unsaturated aldehydes. Unexpected results were found with hindered aldehydes when 2 equiv of base were employed.
Tolerance and dependence to Δ9-tetrahydrocannabinol in rhesus monkeys: Activity assessments

Cannabis withdrawal upon discontinuation of long-term, heavy Cannabis use is reported in humans; however, methods to establish the nature and intensity of cannabinoid withdrawal, especially directly observable signs, have not been widely established. This study quantified activity in the home cage of rhesus monkeys and examined the extent to which activity can be used to quantify tolerance to and dependence on Δ9-tetrahydrocannabinol (Δ9-THC). Home-cage activity was measured in one group that received Δ9-THC (1 mg/kg s.c.) every 12 h (i.e., chronic Δ9-THC), and a second group that received Δ9-THC (0.1 mg/kg i.v.) once every 3 days (i.e., intermittent Δ9-THC). Treatment was temporarily discontinued in the chronic Δ9-THC group and the effects of rimonabant and Δ9-THC were examined in both groups. Activity counts were highest during the day (lights on 0600–2000 h) and were lower at night. Rimonabant (0.1–3.2 mg/kg i.v.) dose-dependently increased activity (maximum 20-fold) in the chronic Δ9-THC group but did not significantly alter activity in the intermittent Δ9-THC group. Δ9-THC (0.32–3.2 mg/kg i.v.) dose-dependently decreased activity counts (maximum 4-fold) in both groups but was somewhat more potent in the intermittent as compared with the Δ9-THC group. Discontinuation of Δ9-THC treatment resulted in an immediate (i.e., within 24 h) and time-related increase in activity. The time-related increase in home-cage activity upon abrupt discontinuation of chronic Δ9-THC treatment, as well as the effects of rimonabant to increase activity in monkeys receiving chronic, but not intermittent, Δ9-THC treatment, are consistent with signs of physical dependence on Δ9-THC in primates.
Mass spectrometry applications in the analysis of nucleosides nucleotides and oligonucleotides

Abstract The past ten years have been an exciting time in mass spectrometry as a number of important instrumental developments have revolutionized the field, including the analysis of nucleic acid components.1,2 The focus of this talk will be on the impact that new ionization methods, e.g., plasma desorption(PD) and fast atom bombardment(FAB), and new magnet technology (expanded mass range and scan speed capability) have had on the analysis of nucleosides and nucleotides. Results from the speaker's laboratory will be used to illustrate the significance of capillary GC/MS techniques for the separation and analysis of complex mixtures of nucleosides derived from a biological source. In addition, some approaches being developed to overcome current limitations in the FAB analysis of nucleosides and nucleotides will be described. Unfortunately, time does not permit a discussion of other new areas of interest, i.e., LC/MS3 and MS/MS.4
Enantioselective Synthesis of the Oxadecalin Core of Phomactin A via a Highly Stereoselective Diels−Alder Reaction

Phomactin A (1) is a selective antagonist of platelet activating factor (PAF). Herein, we report our progress toward the construction of the oxadecalin core of 1. This route is based on the Diels−Alder cycloaddition of an appropriately functionalized vinyl pyran and a complementary dienophile. A model of this reaction involving 2 and maleic anhydride was conducted. Adduct 3 contains the correct stereochemical arrangements between functional groups necessary for gaining access to phomactin A.
Oxidative Rearrangement of 2-Substituted Oxazolines. A Novel Entry to 5,6-Dihydro-2H-1,4-oxazin-2-ones and Morpholin-2-ones

A novel synthesis of 5,6-dihydro-2H-1,4-oxazin-2-ones by SeO2-promoted oxidative rearrangement of 2-alkyl- and 2-(arylmethyl)oxazolines is described. Yields are good to excellent (up to 94%) with t...
Reductive iodonio-Claisen rearrangement of iodothiophene diacetates with allylsilanes: formal synthesis of Plavix®

Abstract Iodothiophene diacetates react with allyltrimethylsilanes in the presence of boron trifluoride diethyl etherate to afford corresponding ortho-allyliodothiophenes via reductive iodonio-Claisen rearrangement. This method has been successfully applied to the synthesis of Plavix®, a blood clot inhibitor used to reduce the risk of heart attack and stroke.
The cis-regulatory logic underlying abdominal Hox-mediated repression versus activation of regulatory elements in Drosophila.

Abstract During development diverse transcription factor inputs are integrated by cis-regulatory modules (CRMs) to yield cell-specific gene expression. Defining how CRMs recruit the appropriate combinations of factors to either activate or repress gene expression remains a challenge. In this study, we compare and contrast the ability of two CRMs within the Drosophila embryo to recruit functional Hox transcription factor complexes. The DCRE CRM recruits Ultrabithorax (Ubx) and Abdominal-A (Abd-A) Hox complexes that include the Extradenticle (Exd) and Homothorax (Hth) transcription factors to repress the Distal-less leg selector gene, whereas the RhoA CRM selectively recruits Abd-A/Exd/Hth complexes to activate rhomboid and stimulate Epidermal Growth Factor secretion in sensory cell precursors. By swapping binding sites between these elements, we found that the RhoA Exd/Hth/Hox site configuration that mediates Abd-A specific activation can convey transcriptional repression by both Ubx and Abd-A when placed into the DCRE. We further show that the orientation and spacing of Hox sites relative to additional binding sites within the RhoA and DCRE is critical to mediate cell- and segment-specific output. These results indicate that the configuration of Exd, Hth, and Hox site within RhoA is neither Abd-A specific nor activation specific. Instead Hox specific output is largely dependent upon the presence of appropriately spaced and oriented binding sites for additional TF inputs. Taken together, these studies provide insight into the cis-regulatory logic used to generate cell-specific outputs via recruiting Hox transcription factor complexes.
Closed-loop feedback control for microfluidic systems through automated capacitive fluid height sensing

Precise fluid height sensing in open-channel microfluidics has long been a desirable feature for a wide range of applications. However, performing accurate measurements of the fluid level in small-scale reservoirs (<1 mL) has proven to be an elusive goal, especially if direct fluid-sensor contact needs to be avoided. In particular, gravity-driven systems used in several microfluidic applications to establish pressure gradients and impose flow remain open-loop and largely unmonitored due to these sensing limitations. Here we present an optimized self-shielded coplanar capacitive sensor design and automated control system to provide submillimeter fluid-height resolution (∼250 μm) and control of small-scale open reservoirs without the need for direct fluid contact. Results from testing and validation of our optimized sensor and system also suggest that accurate fluid height information can be used to robustly characterize, calibrate and dynamically control a range of microfluidic systems with complex pumping mechanisms, even in cell culture conditions. Capacitive sensing technology provides a scalable and cost-effective way to enable continuous monitoring and closed-loop feedback control of fluid volumes in small-scale gravity-dominated wells in a variety of microfluidic applications.
Substantial Cd-Cd bonding in Ca6PtCd11: a condensed intermetallic phase built of pentagonal Cd7 and rectangular Cd4/2Pt pyramids.

The new trail-breaking compound Ca6PtCd11 has been synthesized and its structural and bonding properties investigated. This unusual phase features an unprecedented degree of cadmium aggregation, including linear chains, novel Cd7 PBP aggregates, and edge-shared chains of PtCd4/2 square pyramids. Manifestations of this chemistry elsewhere has evidently been precluded in earlier work by the inclusion of larger amounts of the strong d-metal bonding Au or Pt. Under the right conditions Cd seems quite effective as an open s,p-band metal.
A general and efficient method for the palladium-catalyzed cross-coupling of thiols and secondary phosphines

Abstract The general and efficient cross-coupling of thiols with aryl halides was developed utilizing Pd(OAc)2/1,1′-bis(diisopropylphosphino)ferrocene as the catalyst. The substrate scope is broad and includes a variety of aryl bromides and chlorides, which can be coupled to aliphatic and aromatic thiols. This catalyst system has the widest substrate scope of any reported to date. The present catalyst system also enables the palladium-catalyzed coupling of secondary phosphines with aryl bromides and chlorides.
RapMap: a rapid, sensitive and accurate tool for mapping RNA-seq reads to transcriptomes.

Motivation: The alignment of sequencing reads to a transcriptome is a common and important step in many RNA-seq analysis tasks. When aligning RNA-seq reads directly to a transcriptome (as is common in the de novo setting or when a trusted reference annotation is available), care must be taken to report the potentially large number of multi-mapping locations per read. This can pose a substantial computational burden for existing aligners, and can considerably slow downstream analysis. Results: We introduce a novel concept, quasi-mapping, and an efficient algorithm implementing this approach for mapping sequencing reads to a transcriptome. By attempting only to report the potential loci of origin of a sequencing read, and not the base-to-base alignment by which it derives from the reference, RapMap—our tool implementing quasi-mapping—is capable of mapping sequencing reads to a target transcriptome substantially faster than existing alignment tools. The algorithm we use to implement quasi-mapping uses several efficient data structures and takes advantage of the special structure of shared sequence prevalent in transcriptomes to rapidly provide highly-accurate mapping information. We demonstrate how quasi-mapping can be successfully applied to the problems of transcript-level quantification from RNA-seq reads and the clustering of contigs from de novo assembled transcriptomes into biologically meaningful groups. Availability and implementation: RapMap is implemented in C ++11 and is available as open-source software, under GPL v3, at https://github.com/COMBINE-lab/RapMap. Contact: ude.koorbynots.sc@ortap.bor Supplementary information: Supplementary data are available at Bioinformatics online.
Conditions for modified fischer glycosidations with n‐pentenol and other alcohols

Various O-glycosides were prepared directly from the corresponding aldoses by use of 3 molar equivalents of an alcohol with catalytic amounts of trifluoromethanesulfonic acid (triflic acid) in dimethyl sulfoxide.
Stereoselective Synthesis of C5−C20 and C21−C34 Subunits of the Core Structure of the Aplyronines. Applications of Enantioselective Additions of Chiral Allenylindium Reagents to Chiral Aldehydes

The stereoselective synthesis of a C5−C20 and a C21−C34 subunit of the aplyronine family of polyketide marine macrolides has been achieved. These subunits contain all 15 stereocenters of the core structure. Six of the 15 stereocenters were introduced through enantioselective and diastereoselective additions of chiral allenylindium reagents to α-methyl-β-oxygenated propionaldehydes. The products of these additions were further transformed by reactions involving the terminal alkynyl substituent produced in the addition reactions. Unlike previous applications of this methodology, the present synthesis employs Pd(0)-catalyzed transmetalations of chiral allenylpalladium intermediates to generate the chiral allenylindium reagents in situ.
Swimming sheet in a density-stratified fluid

In this work, we theoretically investigate the swimming velocity of a Taylor swimming sheet immersed in a linearly density-stratified fluid. We use a regular perturbation expansion approach to estimate the swimming velocity up to second order in wave amplitude. We divide our analysis into two regimes of low () and finite Reynolds numbers. We use our solution to understand the effect of stratification on the swimming behaviour of organisms. We find that stratification significantly influences motility characteristics of the swimmer such as the swimming speed, hydrodynamic power expenditure, swimming efficiency and the induced mixing, quantified by mixing efficiency and diapycnal eddy diffusivity. We explore this dependence in detail for both low and finite Reynolds number and elucidate the fundamental insights obtained. We expect our work to shed some light on the importance of stratification in the locomotion of organisms living in density-stratified aquatic environments.
Integrating regulatory DNA sequence and gene expression to predict genome-wide chromatin accessibility across cellular contexts.

Motivation Genome-wide profiles of chromatin accessibility and gene expression in diverse cellular contexts are critical to decipher the dynamics of transcriptional regulation. Recently, convolutional neural networks have been used to learn predictive cis-regulatory DNA sequence models of context-specific chromatin accessibility landscapes. However, these context-specific regulatory sequence models cannot generalize predictions across cell types. Results We introduce multi-modal, residual neural network architectures that integrate cis-regulatory sequence and context-specific expression of trans-regulators to predict genome-wide chromatin accessibility profiles across cellular contexts. We show that the average accessibility of a genomic region across training contexts can be a surprisingly powerful predictor. We leverage this feature and employ novel strategies for training models to enhance genome-wide prediction of shared and context-specific chromatin accessible sites across cell types. We interpret the models to reveal insights into cis- and trans-regulation of chromatin dynamics across 123 diverse cellular contexts. Availability and implementation The code is available at https://github.com/kundajelab/ChromDragoNN. Supplementary information Supplementary data are available at Bioinformatics online.
Implementation Science, Behavior Analysis, and Supporting Evidence-based Practices for Individuals with Autism

Although applied behavior analysis researchers have created efficacious treatment and intervention practices for children and youth with autism spectrum disorder (ASD), there is a gap between research and practice. Implementation Science (IS) and Organizational Behavior Management (OBM), based with Applied Behavior Analysis, are two parallel fields that could close this gap. This paper provides descriptions of both IS and OBM, highlighting their commonalities and unique featuers. The paper concludes with examples of how researchers have used IS and OBM to promote practitioners' use of evidence-based practices and services for children and youth with ASD.
Qubit metrology for building a fault-tolerant quantum computer

Recent progress in quantum information has led to the start of several large national and industrial efforts to build a quantum computer. Researchers are now working to overcome many scientific and technological challenges. The program's biggest obstacle, a potential showstopper for the entire effort, is the need for high-fidelity qubit operations in a scalable architecture. This challenge arises from the fundamental fragility of quantum information, which can only be overcome with quantum error correction. In a fault-tolerant quantum computer the qubits and their logic interactions must have errors below a threshold: scaling up with more and more qubits then brings the net error probability down to appropriate levels ~ $10^{-18}$ needed for running complex algorithms. Reducing error requires solving problems in physics, control, materials and fabrication, which differ for every implementation. I explain here the common key driver for continued improvement - the metrology of qubit errors.
Parameter-free topology inference and sparsification for data on manifolds

In topology inference from data, current approaches face two major problems. One concerns the selection of a correct parameter to build an appropriate complex on top of the data points; the other involves with the typical 'large' size of this complex. We address these two issues in the context of inferring homology from sample points of a smooth manifold of known dimension sitting in an Euclidean space ℝk. We show that, for a sample size of n points, we can identify a set of O(n2) points (as opposed to O(n⌈k/2⌉) Voronoi vertices) approximating a subset of the medial axis that suffices to compute a distance sandwiched between the well known local feature size and the local weak feature size (in fact, the approximating set can be further reduced in size to O(n)). This distance, called the lean feature size, helps pruning the input set at least to the level of local feature size while making the data locally uniform. The local uniformity in turn helps in building a complex for homology inference on top of the sparsified data without requiring any user-supplied distance threshold. Unlike most topology inference results, ours does not require that the input is dense relative to a global feature such as reach or weak feature size; instead it can be adaptive with respect to the local feature size. We present some empirical evidence in support of our theoretical claims.
SAFFRON: A fast, efficient, and robust framework for group testing based on sparse-graph codes

The group testing problem is to identify a population of K defective items from a set of n items by pooling groups of items. The result of a test for a group of items is positive if any of the items in the group is defective and negative otherwise. The goal is to judiciously group subsets of items such that defective items can be reliably recovered using the minimum number of tests, while also having a low-complexity decoder. We describe SAFFRON (Sparse-grAph codes Framework For gROup testiNg), a non-adaptive group testing scheme that recovers at least a (1 − ϵ)-fraction (for any arbitrarily small ϵ > 0) of K defective items with high probability with m = 6C(ϵ)K log 2 n tests, where C(ϵ) is a precisely characterized constant that depends only on o. For instance, it can provably recover at least (1 − 10−6)K defective items with m ≃ 68K log 2 n tests. The computational complexity of the decoding algorithm is O(K log n), which is order-optimal. Further, we describe a systematic methodology to robustify SAFFRON such that it can reliably recover the set of K defective items even in the presence of erroneous or noisy test results. We also propose Singleton-Only-SAFFRON, a variant of SAFFRON, that recovers all the K defective items with m = 2e(1+α)K log K log 2 n tests with probability 1 − O(1/Kα), where α > 0 is a constant. Our key intellectual contribution involves the pioneering use of powerful density-evolution methods of modern coding theory (e.g. sparse-graph codes) for efficient group testing design and performance analysis.
Learning From Noisy Singly-labeled Data

Supervised learning depends on annotated examples, which are taken to be the \emph{ground truth}. But these labels often come from noisy crowdsourcing platforms, like Amazon Mechanical Turk. Practitioners typically collect multiple labels per example and aggregate the results to mitigate noise (the classic crowdsourcing problem). Given a fixed annotation budget and unlimited unlabeled data, redundant annotation comes at the expense of fewer labeled examples. This raises two fundamental questions: (1) How can we best learn from noisy workers? (2) How should we allocate our labeling budget to maximize the performance of a classifier? We propose a new algorithm for jointly modeling labels and worker quality from noisy crowd-sourced data. The alternating minimization proceeds in rounds, estimating worker quality from disagreement with the current model and then updating the model by optimizing a loss function that accounts for the current estimate of worker quality. Unlike previous approaches, even with only one annotation per example, our algorithm can estimate worker quality. We establish a generalization error bound for models learned with our algorithm and establish theoretically that it's better to label many examples once (vs less multiply) when worker quality is above a threshold. Experiments conducted on both ImageNet (with simulated noisy workers) and MS-COCO (using the real crowdsourced labels) confirm our algorithm's benefits.
Extreme points of a ball about a measure with finite support

We show that, for the space of Borel probability measures on a Borel subset of a Polish metric space, the extreme points of the Prokhorov, Monge–Wasserstein and Kantorovich metric balls about a measure whose support has at most n points, consist of measures whose supports have at most n+2 points. Moreover, we use the Strassen and Kantorovich–Rubinstein duality theorems to develop representations of supersets of the extreme points based on linear programming, and then develop these representations towards the goal of their efficient computation.
Zeta-polynomials for modular form periods

Abstract Answering problems of Manin, we use the critical L-values of even weight k ≥ 4 newforms f ∈ S k ( Γ 0 ( N ) ) to define zeta-polynomials Z f ( s ) which satisfy the functional equation Z f ( s ) = ± Z f ( 1 − s ) , and which obey the Riemann Hypothesis: if Z f ( ρ ) = 0 , then Re ( ρ ) = 1 / 2 . The zeros of the Z f ( s ) on the critical line in t-aspect are distributed in a manner which is somewhat analogous to those of classical zeta-functions. These polynomials are assembled using (signed) Stirling numbers and “weighted moments” of critical L-values. In analogy with Ehrhart polynomials which keep track of integer points in polytopes, the Z f ( s ) encode arithmetic information. Assuming the Bloch–Kato Tamagawa Number Conjecture, they encode the arithmetic of a combinatorial arithmetic–geometric object which we call the “Bloch–Kato complex” for f. Loosely speaking, these are graded sums of weighted moments of orders of Safarevic–Tate groups associated to the Tate twists of the modular motives.
Numerical and Symbolic Studies of the Peaceable Queens Problem

We discuss, and make partial progress on, the peaceable queens problem, the protagonist of OEIS sequence A250000. Symbolically, we prove that Jubin’s construction of two pentagons is at least a loc...
A unified deep neural network for speaker and language recognition.

Significant performance gains have been reported separately for speaker recognition (SR) and language recognition (LR) tasks using either DNN posteriors of sub-phonetic units or DNN feature representations, but the two techniques have not been compared on the same SR or LR task or across SR and LR tasks using the same DNN. In this work we present the application of a single DNN for both tasks using the 2013 Domain Adaptation Challenge speaker recognition (DAC13) and the NIST 2011 language recognition evaluation (LRE11) benchmarks. Using a single DNN trained on Switchboard data we demonstrate large gains in performance on both benchmarks: a 55% reduction in EER for the DAC13 out-of-domain condition and a 48% reduction in Cavg on the LRE11 30s test condition. Score fusion and feature fusion are also investigated as is the performance of the DNN technologies at short durations for SR. Index Terms: i-vector, DNN, bottleneck features, speaker recognition, language recognition
Relative index pairing and odd index theorem for even dimensional manifolds

Abstract We prove an analogue for even dimensional manifolds of the Atiyah–Patodi–Singer twisted index theorem for trivialized flat bundles. We show that the eta invariant appearing in this result coincides with the eta invariant by Dai and Zhang up to an integer. We also obtain the odd dimensional counterpart for manifolds with boundary of the relative index pairing by Lesch, Moscovici and Pflaum.
Coded Caching with Low Subpacketization Levels

Caching is popular technique in content delivery networks that allows for reductions in transmission rates from the content-hosting server to the end users. Coded caching is a generalization of conventional caching that considers the possibility of coding in the caches and transmitting coded signals from the server. Prior results in this area demonstrate that huge reductions in transmission rates are possible and this makes coded caching an attractive option for the next generation of content-delivery networks. However, these results require that each file hosted in the server be partitioned into a large number (i.e., the subpacketization level) of non- overlapping subfiles. From a practical perspective, this is problematic as it means that prior schemes are only applicable when the size of the files is extremely large. In this work, we propose a novel coded caching scheme that enjoys a significantly lower subpacketization level than prior schemes, while only suffering a marginal increase in the transmission rate. In particular, for a fixed cache size, the scaling with the number of users is such that the increase in transmission rate is negligible, but the decrease in subpacketization level is exponential.
Safety control of monotone systems with bounded uncertainties

Monotone systems are prevalent in models of engineering applications such as transportation and biological networks. In this paper, we investigate the problem of finding a control strategy for a discrete time positive monotone system with bounded uncertainties such that the evolution of the system is guaranteed to be confined to a safe set in the state space for all times. By exploiting monotonicity, we propose an approach to this problem which is based on constraint programming. We find control strategies that are based on repetitions of finite sequences of control actions. We show that, under assumptions made in the paper, safety control of monotone systems does not require state measurement. We demonstrate the results on a signalized urban traffic network, where the safety objective is to keep the traffic flow free of congestion.
Toward single electron resolution phonon mediated ionization detectors

Abstract Experiments seeking to detect rare event interactions such as dark matter or coherent elastic neutrino nucleus scattering are striving for large mass detectors with very low detection threshold. Using Neganov-Luke phonon amplification effect, the Cryogenic Dark Matter Search (CDMS) experiment is reaching unprecedented RMS resolutions of ∼14 eVee. CDMSlite is currently the most sensitive experiment to WIMPs of mass ∼5 GeV/c2 but is limited in achieving higher phonon gains due to an early onset of leakage current into Ge crystals. The contact interface geometry is particularly weak for blocking hole injection from the metal, and thus a new design is demonstrated that allows high voltage bias via vacuum separated electrode. With an increased bias voltage and a×2 Luke phonon gain, world best RMS resolution of sigma ∼7 eVee for 0.25 kg (d=75 mm, h=1 cm) Ge detectors was achieved. Since the leakage current is a function of the field and the phonon gain is a function of the applied voltage, appropriately robust interface blocking material combined with thicker substrate (25 mm) will reach a resolution of ∼2.8 eVee. In order to achieve better resolution of ∼ eV, we are investigating a layer of insulator between the phonon readout surface and the semiconductor crystals.
Marked-length-spectral rigidity for flat metrics

In this paper we prove that the space of at metrics (nonpos- itively curved Euclidean cone metrics) on a closed, oriented surface is marked length spectrally rigid. In other words, two at metrics assigning the same lengths to all closed curves dier by an isometry isotopic to the identity.
On the effect of vibration on shape sensing of continuum manipulators using fiber Bragg gratings

Fiber Bragg Grating (FBG) has shown great potential in shape and force sensing of continuum manipulators (CM) and biopsy needles. In the recent years, many researchers have studied different manufacturing and modeling techniques of FBG-based force and shape sensors for medical applications. These studies mainly focus on obtaining shape and force information in a static (or quasi-static) environment. In this paper, however, we study and evaluate dynamic environments where the FBG data is affected by vibration caused by a harmonic force e.g. a rotational debriding tool harmonically exciting the CM and the FBG-based shape sensor. In such situations, appropriate pre-processing of the FBG signal is necessary in order to infer correct information from the raw signal. We look at an example of such dynamic environments in the less invasive treatment of osteolysis by studying the FBG data both in time- and frequency-domain in presence of vibration due to a debriding tool rotating inside the lumen of the CM.
Rate of convergence for large coupling limits in Sobolev spaces

ABSTRACTWe estimate the rate of convergence, in the so-called large coupling limit, for Schrodinger-type operators on bounded domains with “interaction potentials” supported in a compact inclusion. We show that if the boundary of the inclusion is suﬃciently smooth, one essentially recovers the “free Hamiltonian” in the exterior domain with Dirichlet boundary conditions. In addition, we obtain a convergence rate, in L2, that is , where λ is the coupling parameter. Our methods include energy estimates, trace estimates, interpolation, and duality.
Structured Interpretation of Temporal Relations

Temporal relations between events and time expressions in a document are often modeled in an unstructured manner where relations between individual pairs of time expressions and events are considered in isolation. This often results in inconsistent and incomplete annotation and computational modeling. We propose a novel annotation approach where events and time expressions in a document form a dependency tree in which each dependency relation corresponds to an instance of temporal anaphora where the antecedent is the parent and the anaphor is the child. We annotate a corpus of 235 documents using this approach in the two genres of news and narratives, with 48 documents doubly annotated. We report a stable and high inter-annotator agreement on the doubly annotated subset, validating our approach, and perform a quantitative comparison between the two genres of the entire corpus. We make this corpus publicly available.
Local Optimality and Generalization Guarantees for the Langevin Algorithm via Empirical Metastability

We study the detailed path-wise behavior of the discrete-time Langevin algorithm for non-convex Empirical Risk Minimization (ERM) through the lens of metastability, adopting some techniques from Berglund and Gentz (2003. For a particular local optimum of the empirical risk, with an arbitrary initialization, we show that, with high probability, at least one of the following two events will occur: (1) the Langevin trajectory ends up somewhere outside the $\varepsilon$-neighborhood of this particular optimum within a short recurrence time; (2) it enters this $\varepsilon$-neighborhood by the recurrence time and stays there until a potentially exponentially long escape time. We call this phenomenon empirical metastability. This two-timescale characterization aligns nicely with the existing literature in the following two senses. First, the effective recurrence time (i.e., number of iterations multiplied by stepsize) is dimension-independent, and resembles the convergence time of continuous-time deterministic Gradient Descent (GD). However unlike GD, the Langevin algorithm does not require strong conditions on local initialization, and has the possibility of eventually visiting all optima. Second, the scaling of the escape time is consistent with the Eyring-Kramers law, which states that the Langevin scheme will eventually visit all local minima, but it will take an exponentially long time to transit among them. We apply this path-wise concentration result in the context of statistical learning to examine local notions of generalization and optimality.
The Lp Minkowski problem for polytopes for 0<p<1

Abstract Necessary and sufficient conditions are given for the existence of solutions to the discrete L p Minkowski problem for the critical case where 0 p 1 .
The nef cone of the moduli space of sheaves and strong Bogomolov inequalities

Let (X,H) be a polarized, smooth, complex projective surface, and let v be a Chern character on X with positive rank and sufficiently large discriminant. In this paper, we compute the Gieseker wall for v in a slice of the stability manifold of X. We construct explicit curves parameterizing nonisomorphic Gieseker stable sheaves of character v that become S-equivalent along the wall. As a corollary, we conclude that if there are no strictly semistable sheaves of character v, the Bayer–Macri divisor associated to the wall is a boundary nef divisor on the moduli space of sheaves MH(v). We recover previous results for ℙ2 and K3 surfaces, and illustrate applications to higher Picard rank surfaces with an example on ℙ1 × ℙ1.
Dimension estimates for sets of uniformly badly approximable systems of linear forms

The set of badly approximable m × n matrices is known to have Hausdorff dimension mn. Each such matrix comes with its own approximation constant c, and one can ask for the dimension of the set of badly approximable matrices with approximation constant greater than or equal to some fixed c. In the one-dimensional case, a very precise answer to this question is known. In this note, we obtain upper and lower bounds in higher dimensions. The lower bounds are established via the technique of Schmidt games, while for the upper bound we use homogeneous dynamics methods, namely exponential mixing of flows on the space of lattices.
Hyperspectral Unmixing Via Turbo Bilinear Approximate Message Passing

The goal of hyperspectral unmixing is to decompose an electromagnetic spectral dataset measured over $M$ spectral bands and $T$ pixels into $N$ constituent material spectra (or “endmembers”) with corresponding spatial abundances. In this paper, we propose a novel approach to hyperspectral unmixing based on loopy belief propagation (BP) that enables the exploitation of spectral coherence in the endmembers and spatial coherence in the abundances. In particular, we partition the factor graph into spectral coherence, spatial coherence, and bilinear subgraphs, and pass messages between them using a “turbo” approach. To perform message passing within the bilinear subgraph, we employ the bilinear generalized approximate message passing algorithm (BiG-AMP), a recently proposed belief-propagation-based approach to matrix factorization. Furthermore, we propose an expectation-maximization (EM) strategy to tune the prior parameters and a model-order selection strategy to select the number of materials $N$ . Numerical experiments conducted with both synthetic and real-world data show favorable unmixing performance relative to existing methods.
Finiteness properties of the Johnson subgroups

Abstract The main goal of this note is to provide evidence that the first rational homology of the Johnson subgroup K g , 1 of the mapping class group of a genus g surface with one marked point is finite-dimensional. Building on work of Dimca–Papadima [4] , we use symplectic representation theory to show that, for all g > 3 , the completion of H 1 ( K g , 1 , Q ) with respect to the augmentation ideal in the rational group algebra of Z 2 g is finite-dimensional. We also show that the terms of the Johnson filtration of the mapping class group have infinite-dimensional rational homology in some degrees in almost all genera, generalizing a result of Akita.
PULLING BACK COHOMOLOGY CLASSES AND DYNAMICAL DEGREES OF MONOMIAL MAPS

We study the pullback maps on cohomology groups for equivariant rational maps (i.e., monomial maps) on toric varieties. Our method is based on the intersection theory on toric varieties. We use the method to determine the dynamical degrees of monomial maps and compute the degrees of the Cremona involution.
Macro Grammars and Holistic Triggering for Efficient Semantic Parsing

To learn a semantic parser from denotations, a learning algorithm must search over a combinatorially large space of logical forms for ones consistent with the annotated denotations. We propose a new online learning algorithm that searches faster as training progresses. The two key ideas are using macro grammars to cache the abstract patterns of useful logical forms found thus far, and holistic triggering to efficiently retrieve the most relevant patterns based on sentence similarity. On the WikiTableQuestions dataset, we first expand the search space of an existing model to improve the state-of-the-art accuracy from 38.7% to 42.7%, and then use macro grammars and holistic triggering to achieve an 11x speedup and an accuracy of 43.7%.
Equivariant sheaves on some spherical varieties

We provide a concrete description of the category of equivariant vector bundles on a class of spherical $\G$-varieties.
Handover Count Based Velocity Estimation and Mobility State Detection in Dense HetNets

In wireless cellular networks with densely deployed base stations, knowing the velocities of mobile devices is key to avoiding call drops and improving the quality of service to the user equipments (UEs). A simple and efficient way to estimate a UE’s velocity is by counting the number of handovers made by the UE during a predefined time window. Indeed, handover-count based mobility state detection has been standardized since long term evolution (LTE) Release-8 specifications. The increasing density of small cells in wireless networks can help in accurate estimation of velocity and mobility state of a UE. In this paper, we model densely deployed small cells using stochastic geometry, and then analyze the statistics of the number of handovers as a function of UE velocity, small-cell density, and handover count measurement time window. Using these statistics, we derive approximations to the Cramer–Rao lower bound (CRLB) for the velocity estimate of a UE. Also, we determine a minimum variance unbiased (MVU) velocity estimator whose variance tightly matches with the CRLB. Using this velocity estimator, we formulate the problem of detecting the mobility state of a UE as low, medium, or high-mobility, as in LTE specifications. Subsequently, we derive the probability of correctly detecting the mobility state of a UE. Finally, we evaluate the accuracy of the velocity estimator under more realistic scenarios such as clustered deployment of small cells, random way point (RWP) mobility model for UEs, and variable UE velocity. Our analysis shows that the accuracy of velocity estimation and mobility state detection increases with increasing small cell density and with increasing handover count measurement time window.
An index of strongly Callias operators on Lorentzian manifolds with non-compact boundary

We consider hyperbolic Dirac-type operator with growing potential on a spatially non-compact globally hyperbolic manifold. We show that the Atiyah-Patodi-Singer boundary value problem for such operator is Fredholm and obtain a formula for this index in terms of the local integrals and the relative eta-invariant introduced by Braverman and Shi. This extends recent results of Bar and Strohmaier, who studied the index of a hyperbolic Dirac operator on a spatially compact globally hyperbolic manifold.
Memory-Based Combination PUFs for Device Authentication in Embedded Systems

Embedded systems play a crucial role in fueling the growth of the Internet-of-Things (IoT) in application domains such as health care, home automation, transportation, etc. However, their increasingly network-connected nature, coupled with their ability to access potentially sensitive/confidential information, has given rise to a plethora of security and privacy concerns. An additional challenge is the growing number of counterfeit components in these devices, with serious reliability and financial repercussions. Physically Unclonable Functions (PUFs) are a promising security primitive to help address these concerns. Memory-based PUFs are particularly attractive as they can be realized with minimal or no additional hardware beyond what is already present in all embedded systems, i.e., memory. However, current memory-based PUFs utilize only a single memory technology for constructing the PUF, which has many disadvantages including making them vulnerable to certain security attacks. Several of these PUFs also suffer from other shortcomings such as low entropy, limited number of challenge-response pairs, etc. In this paper, we propose the design of a new memory-based combination PUF that tightly integrates (two) heterogeneous memory technologies to address these challenges/shortcomings. Our design enables us to authenticate an on-chip component and an off-chip component, thereby taking a step towards multi-component authentication in a device, without incorporating any additional hardware. We have implemented a prototype of the proposed combination PUF using a Terasic TR4-230 FPGA development board and several off-the-shelf SRAMs and DRAMs. Measured experimental results demonstrate substantial improvements over current memory-based PUFs including the ability to resist various security attacks. We also propose a lightweight authentication scheme that ensures robust operation of the PUF across environmental and temporal variations. Extensive authentication tests performed on several PUF prototypes achieved a true-positive rate of greater than 97.5 percent across these variations. The absence of any false-positives, even under an invasive attack, further highlighted the effectiveness of the overall design.