cssi/SciSciGPT-SciSciNet huggingface dataset:
The Nature, Extent, and Consequences of Genetic Variation in the opa Repeats of Notch in Drosophila

Polyglutamine (pQ) tracts are abundant in proteins co-interacting on DNA. The lengths of these pQ tracts can modulate their interaction strengths. However, pQ tracts >40 residues are pathologically prone to amyloidogenic self-assembly. Here, we assess the extent and consequences of variation in the pQ-encoding opa repeats of Notch in Drosophila melanogaster. We use Sanger sequencing to genotype opa sequences ([Formula: see text]-CAX repeats), which have resisted assembly using short sequence reads. While most sampled lines carry the major allele opa31 encoding Q13HQ17 or the opa32 allele encoding Q13HQ18, many lines carry rare alleles encoding pQ tracts >32 residues: opa33a (Q14HQ18), opa33b (Q15HQ17), opa34 (Q16HQ17), opa35a1/opa35a2 (Q13HQ21), opa36 (Q13HQ22), and opa37 (Q13HQ23). Only one rare allele encodes a tract <31 residues: opa23 (Q13-Q10). This opa23 allele shortens the pQ tract while simultaneously eliminating the interrupting histidine. We introgressed these opa variant alleles into common backgrounds and measured the frequency of Notch-type phenotypes. Homozygotes for the short and long opa alleles have defects in embryonic survival and sensory bristle organ patterning, and sometimes show wing notching. Consistent with functional differences between Notch opa variants, we find that a scute inversion carrying the rare opa33b allele suppresses the bristle patterning defect caused by achaete/scute insufficiency, while an equivalent scute inversion carrying opa31 manifests the patterning defect. Our results demonstrate the existence of potent pQ variants of Notch and the need for long read genotyping of key repeat variables underlying gene regulatory networks.
The chemistry of the carbon–transition metal double and triple bond: annual survey covering the year 1999

Abstract This survey is intended to be a comprehensive summary of articles that report on the synthesis, reactivity, or properties of compounds featuring a multiple bond between carbon and a transition metal. Reactions which employ metal carbene complexes as transient intermediates generated through well-established routes [Russ. Chem. Bull. 48 (1999) 16] are not covered unless there is some effort to characterize the carbene complex intermediate. Although a determined effort has been made to include patents, in general only patents which are listed in or at the end of Organometallics section of Chemical Abstracts (Section 29) are included; patents which appeared in Chemical Abstracts in the year 1999 have been included. Only compounds which feature a multiple bond between one carbon atom and one transition metal are discussed in this survey, thus bridging carbene and carbyne complexes are not covered unless there is a multiple bond to at least one transition metal. The complexes of stable carbenes with transition metals have not been included; since the π-donation component of these complexes is minimal, there is no formal carbonmetal multiple bond [J. Chem. Soc., Chem. Commun. (1997) 1963; Polyhedron 16 (1997) 3879]. This survey has been divided into two sections, metal carbene (or alkylidene) complexes and metal carbyne (or alkylidyne) complexes; the carbene complex section represents the vast majority of this article. The metal carbene section has been organized according to metal, starting from the left side of the periodic table. The ionic model [R.H. Crabtree, The Organometallic Chemistry of the Transition Metals, second ed., Wiley-Interscience, New York, 1994, pp. 25–31] has been employed for the discussion of oxidation states and ligand electron count throughout this survey. A special section focusing on alkene metathesis has been included prior to the discussion of carbene complexes of individual metals. The metal carbyne section has been organized according to reaction type.
Regulation of community functional composition across taxonomic variation by resource-consumer dynamics

High-throughput sequencing techniques such as metagenomic and metatranscriptomic technologies allow cataloging of functional characteristics of microbial community members as well as their taxonomic identity. Such studies have found that a community9s composition in terms of ecologically relevant functional traits or guilds can be conserved more strictly across varying settings than taxonomic composition is. I use a standard ecological resource-consumer model to examine the dynamics of traits relevant to resource consumption, and analyze determinants of functional composition. This model demonstrates that interaction with essential resources can regulate the community-wide abundance of ecologically relevant traits, keeping them at consistent levels despite large changes in the abundances of the species housing those traits in response to changes in the environment, and across variation between communities in species composition. Functional composition is shown to be able to track differences in environmental conditions faithfully across differences in community composition. Mathematical conditions on consumers9 vital rates and functional responses sufficient to produce conservation of functional community structure across taxonomic differences are presented.
Efficient synthesis of substituted piperazinones via tandem reductive amination–cyclization

Abstract A new strategy for the preparation of substituted piperazinones features a tandem reductive coupling and S N 2-cyclization of a 2-chloro- N -(2-oxoalkyl)acetamide ( 1 ) and a primary amine ( 2) . The method is convenient for diversity-oriented synthesis, since a wide variety of amines may be used in the ring-forming reaction to produce N -substituted piperazinones ( 3 ).
Gamma Oscillations in the Rat Ventral Striatum Originate in the Piriform Cortex.

Local field potentials (LFPs) recorded from the human and rodent ventral striatum (vStr) exhibit prominent, behaviorally relevant gamma-band oscillations. These oscillations are related to local spiking activity and transiently synchronize with anatomically related areas, suggesting a possible role in organizing vStr activity. However, the origin of vStr gamma is unknown. We recorded vStr gamma oscillations across a 1.4 mm 2 grid spanned by 64 recording electrodes as male rats rested and foraged for rewards, revealing a highly consistent power gradient originating in the adjacent piriform cortex. Phase differences across the vStr were consistently small ( SIGNIFICANCE STATEMENT The ventral striatum (vStr) is an area of anatomical convergence in circuits underlying motivated behavior, but it remains unclear how its inputs from different sources interact. A major proposal about how neural circuits may switch dynamically between convergent inputs is through temporal organization reflected in local field potential (LFP) oscillations. Our results show that, in the rat, the mechanisms controlling gamma-band oscillations in the vStr LFP are primarily located in the in the adjacent piriform cortex rather than in the vStr itself, providing a novel interpretation of previous rodent work on gamma oscillations in the vStr and related circuits and an important consideration for future work seeking to use oscillations in these areas as biomarkers for behavioral and neurological disorders.
A new approach to the pancratistatin C-ring from d-glucose: Ferrier rearrangement, pseudoinversion and Pd-catalyzed cyclizations

Abstract A Ferrier rearrangement and β-hydroxyketone transposition are key steps in a route to a pancratistatin C-ring precursor. A key feature of the strategy is the pseudoinversion accomplished by β-hydroxyketone transposition, which allows convenient access from methyl α- d -glucopyranoside. Arylations of the C-ring by intramolecular reductive or non-reductive Pd-catalyzed conjugate addition have been demonstrated, utilizing the C1 hydroxyl to deliver the tethered aryl synthon.
Ultracold molecules from ultracold atoms: a case study with the KRb molecule

Ultracold collisions of cold atoms or molecules make the bound states of the collision complex formed from the two colliding species accessible for control and manipulation of the cold species or the complex. Such resonances are best treated by a resonant scattering theory, which in the ultracold domain can take advantage of the properties of the long-range potential and the methods of multichannel quantum defect theory. Coupled channels calculations on the threshold scattering states and bound states of the 40K87Rb molecule illustrate the ideas and methodology of quantum defect theory using the long-range potential and also demonstrate the spin properties of the bound states throughout the spectrum.
Curating Clinically Relevant Transcripts for the Interpretation of Sequence Variants

Variant interpretation depends on accurate annotations using biologically relevant transcripts. We have developed a systematic strategy for designating primary transcripts and have applied it to 109 hearing loss–associated genes that were divided into three categories. Category 1 genes (n = 38) had a single transcript; category 2 genes (n = 33) had multiple transcripts, but a single transcript was sufficient to represent all exons; and category 3 genes (n = 38) had multiple transcripts with unique exons. Transcripts were curated with respect to gene expression reported in the literature and the Genotype-Tissue Expression Project. In addition, high-frequency loss-of-function variants in the Genome Aggregation Database and disease-causing variants in ClinVar and the Human Gene Mutation Database across the 109 genes were queried. These data were used to classify exons as clinically significant, insignificant, or of uncertain significance. Interestingly, 6% of all exons, containing 124 reportedly disease-causing variants, were of uncertain significance. Finally, we used exon-level next-generation sequencing quality metrics generated at two clinical laboratories and identified a total of 43 technically challenging exons in 20 different genes that had inadequate coverage and/or homology issues that might lead to false-variant calls. We have demonstrated that transcript analysis plays a critical role in accurate clinical variant interpretation.
Measuring clinically relevant knee motion with a self-calibrated wearable sensor.

Abstract Low-cost sensors provide a unique opportunity to continuously monitor patient progress during rehabilitation; however, these sensors have yet to demonstrate the fidelity and lack the calibration paradigms necessary to be viable tools for clinical research. The purpose of this study was to validate a low-cost wearable sensor that accurately measured peak knee extension during clinical exercises and needed no additional equipment for calibration. Sagittal plane knee motion was quantified using a 9-axis motion sensor and directly compared to motion capture data. The motion sensor measured the field strength of a strong earth magnet secured to the distal femur, which was correlated with knee angle during a simple calibration process. Peak knee motions and kinematic patterns were compared with motion capture data using paired t-tests and cross correlation, respectively. Peak extension values during seated knee extensions were accurate within 5 degrees across all subjects (root mean square error: 2.6 degrees, P = 0.29). Knee flexion during gait strongly correlated (0.84 ≤ rxy ≤ 0.99) with motion capture measurements but demonstrated peak flexion errors of 10 degrees. In this study, we present a low-cost sensor (≈$ 35 US) that accurately determines knee extension angle following a calibration procedure that did not require any other equipment. Our findings demonstrate that this sensor paradigm is a feasible tool to monitor patient progress throughout physical therapy. However, dynamic motions that are associated with soft-tissue artifact may limit the accuracy of this type of wearable sensor.
Facile synthesis of 4,5-disubstituted-3(2H)-pyridazinones

4,5-Disubstituted-3(2H)-pyridazinones were initially synthesized via sodium alkoxide additions to an advanced bromide intermediate. A small parallel chemistry effort resulted in a poor success rate, and we thus increased the reactivity of the reaction partner by performing a copper-catalyzed Finkelstein reaction. Copper-catalyzed coupling of a diverse set of alcohols with the resulting iodide resulted in a more successful effort. A number of alternative syntheses of this series of compounds are also described and these methods proved to be versatile, efficient, and amenable to parallel synthesis.
Role of the C(1) Triol Group in Bicyclomycin: Synthesis and Biochemical and Biological Properties.

Bicyclomycin (1) is a commercial antibiotic whose primary site of action in Escherichia coli is the essential cellular protein transcription termination factor rho. The bicyclomycin binding domain in rho is unknown; however, enzyme irreversible inactivators that modify rho upon activation may identify the site. In this study, we investigated the importance for rho binding of the C(1) triol group in 1. Twelve bicyclomycin derivatives were prepared, and the C(1) triol group was modified at the C(1‘), the C(2‘), and the C(3‘) sites. The compounds were evaluated by rho-dependent ATPase and transcription termination assays and their antimicrobial activities assessed using a filter disc assay. Bicyclomycin inhibited both rho-dependent ATPase (I50 = 60 μM) and rho-dependent transcription termination (I50 ∼ 5 μM) processes and had a minimum inhibitory concentration value of 0.25 mg/mL against E. coli W3350 cells. None of the 12 C(1) triol bicyclomycin derivatives significantly inhibited rho-dependent ATPase (I50 ...
Oxidative cyclotrimerization of unsaturated compounds with DDQ and triflic acid: An efficient synthetic route to triply-fused benzene rings

Abstract Intermolecular oxidative cyclotrimerization reactions of alkenes and aromatic compounds with DDQ and trifluoromethanesulfonic acid are described. Scholl-type oxidation reactions involving alkenes have not previously been demonstrated. Moreover, the DDQ/acid system has never been used for intermolecular oxidative cyclization reactions. This convenient, metal-free reagent system (DDQ/TfOH) is advantageous with respect to metal-based Scholl-type oxidants because it eliminates the possibility of halogenation of aromatic compounds as a competing side reaction.
Estimation of swine movement network at farm level in the US from the Census of Agriculture data

Swine movement networks among farms/operations are an important source of information to understand and prevent the spread of diseases, nearly nonexistent in the United States. An understanding of the movement networks can help the policymakers in planning effective disease control measures. The objectives of this work are: (1) estimate swine movement probabilities at the county level from comprehensive anonymous inventory and sales data published by the United States Department of Agriculture - National Agriculture Statistics Service database, (2) develop a network based on those estimated probabilities, and (3) analyze that network using network science metrics. First, we use a probabilistic approach based on the maximum information entropy method to estimate the movement probabilities among different swine populations. Then, we create a swine movement network using the estimated probabilities for the counties of the central agricultural district of Iowa. The analysis of this network has found evidence of the small-world phenomenon. Our study suggests that the US swine industry may be vulnerable to infectious disease outbreaks because of the small-world structure of its movement network. Our system is easily adaptable to estimate movement networks for other sets of data, farm animal production systems, and geographic regions.
Highly diastereoselective conjugate additions of monoorganocopper reagents to chiral imides

Abstract Stereoselective conjugate additions to chiral N -enoyl amides employing various monoorganocuprate reagents, Li[RCuI], are described. The presence of TMSI in the addition of Li[RCuI] in THF provided the highest stereoselectivities. Reversed major diastereomeric ratios were obtained employing Li[RCuI] in ether or conventional copper-promoted Grignard reagents. The results presented support the favored anti - s - cis conformation of the substrates using Li[RCuI]/TMSI in THF, while the copper-promoted Grignard reagents or the Li[RCuI] reagents in ether favor the opposite syn - s - cis conformation. Influence of lithium ions on the stereoselective conjugate addition of the monoorganocuprate reagent, Li[BuCuI], has been investigated and two different mechanistic pathways are presented. The results show that iodotrimethylsilane (TMSI) is crucial for the asymmetric conjugate addition of the copper reagent, but only in THF or when 12-crown-4 is used. The reaction is thought not to involve any halosilane in any critical steps in the organocopper mechanisms conducted in ether. The (CuI) 4 (SMe 2 ) 3 complex precursor plays an instrumental role for the conjugate addition using monoorganocopper reagents.
Bioactive 2-Oxazolines: A New Approach via One-Pot, Four-Component Reaction

Substituted 2-oxazolines of the general structure shown above are found in several families of bioactive natural products and can be prepared in an efficient and general one-pot, four-component condensation.
H2GaN3 and Derivatives: A Facile Method to Gallium Nitride

We describe the formation and properties of H2GaN3 (1), which is a very simple and stable molecular source for chemical vapor deposition (CVD) of GaN heterostructures. Compound 1 and the perdeutera...
Amine templating effect absent in uranyl sulfates synthesized with 1,4-n-butyldiamine

Abstract Two new uranyl sulfates, (C4H14N2)[(UO2)2(SO4)3(H2O)]·2H2O (NDUS2) and (C4H14N2)[(UO2)(SO4)2(H2O)]·2H2O (NDUS3), were synthesized and their crystal structures determined. NDUS2 was obtained in highly acidic media heat-treated at 373 K and subsequently maintained at 278 K until crystals formed after two months. NDUS3 results from the degradation of NDUS2 over the course of a few days. NDUS2 and NDUS3 crystallize in the monoclinic space group P21/n, a=10.9075(4) A, b=10.4513(4) A, c=17.7881(7) A, β=97.908(2)°, V=2008.52(13) A3, Z=4, at 140 K and a=8.8570(4) A, b=7.3299(3) A, c=20.4260(9) A, β=95.140(2)°, V=1320.74(10) A3, Z=4, at 140 K, respectively. The compounds contain interlayer 1,4-n-butyldiammonium cations that charge-balance the anionic structural units.
From catalyst preparation toward catalyst synthesis

Abstract As catalysis research has evolved from resolution of functions such as metals and acids and experiments with model catalysts toward identification of catalytic sites, catalyst preparation has evolved toward catalyst synthesis. This argument is developed on the basis of examples of catalysts that are less complex structurally than typical industrial solid catalysts; the examples include metal complexes bonded to supports, through tethers or metal–oxygen bonds, and crystalline porous materials such as zeolites. With such materials, especially molecular species bonded to crystalline supports, catalyst synthesis is a reality and the notion of catalyst design is becoming realistic.
Synthesis of imidazole and imidazolium porphyrins

A new porphyrin compound, where an imidazole group was attached through the 1-position nitrogen to a phenyl ring located on the porphyrin periphery has been synthesized and characterized. The second nitrogen on the imidazole is available for further chemistry as demonstrated by the attachment of bromopentane forming the imidazolium porphyrin complex. This is the first example of an imidazolium group covalently attached to the porphyrin periphery in which the porphyrin is attached through the nitrogen on the imidazole ring rather than a carbon atom.
Fluorophenyl bilirubins: Synthesis and stereochemistry

Analogs of bilirubin with vinyl groups replaced by symmetrically-disposed o-fluorophenyls (1, bis-exo, and 2, bis-endo) were synthesized and characterized spectroscopically. Their 1H NMR spectra and NOE data are consistent with an intramolecularly hydrogen-bonded ridge-tile conformation where each propionic acid group embraces an opposing dipyrrinone. Like bilirubin, 1 and 2 exhibit negative chirality induced circular dichroism (ICD) Cotton effects in chloroform containing quinine. Unlike bilirubin, however, in aqueous buffer containing human serum albumin, 2 exhibits a negative exciton chirality ICD, whereas that of 1 is positive.
A comparison of 2 distal attachment mucosal exposure devices: a noninferiority randomized controlled trial.

Background and Aims Endocuff (Arc Medical Design, Leeds, UK) and Endocuff Vision (Arc Medical Design, Leeds, UK) are effective mucosal exposure devices for improving polyp detection during colonoscopy. AmplifEYE (Medivators Inc, Minneapolis, Minn, USA) is a device that appears similar to the Endocuff devices but has received minimal clinical testing. Methods We performed a randomized controlled clinical trial using a noninferiority design to compare Endocuff Vision with AmplifEYE. Results The primary endpoint of adenomas per colonoscopy was similar in AmplifEYE at 1.63 (standard deviation 2.83) versus 1.51 (2.29) with Endocuff Vision (P = .535). The 95% lower confidence limit was 0.88 for ratio of means, establishing noninferiority of AmplifEYE (P = .008). There was no difference between the arms for mean insertion time, and mean inspection time (withdrawal time minus polypectomy time and time for washing and suctioning) was shorter with AmplifEYE (6.8 minutes vs 6.9 minutes, P = .042). Conclusions AmplifEYE is noninferior to Endocuff Vision for adenoma detection. The decision on which device to use can be based on cost. Additional comparisons of AmplifEYE with Endocuff by other investigators are warranted. (Clinical trial registration number: NCT03560128.)
Graph saturation in multipartite graphs

Let G be a fixed graph and let F be a family of graphs. A subgraph J of G is F-saturated if no member of F is a subgraph of J, but for any edge e in E(G)−E(J), some element of F is a subgraph of J + e. We let ex(F,G) and sat(F,G) denote the maximum and minimum size of an F-saturated subgraph of G, respectively. If no element of F is a subgraph of G, then sat(F,G) = ex(F,G) = jE(G)j. In this paper, for k � 3 and n � 100 we determine sat(K3,K n ), where K n k is the complete balanced k-partite graph with partite sets of size n. We also give several families of constructions of Kt-saturated subgraphs of K n k for t � 4. Our results and constructions provide an informative contrast to recent results on the edge-density version of ex(Kt,K n
Asymptotic optimality of sparse linear discriminant analysis with arbitrary number of classes

Many sparse linear discriminant analysis (LDA) methods have been proposed to overcome the major problems of the classic LDA in high-dimensional settings. However, the asymptotic optimality results are limited to the case that there are only two classes, which is due to the fact that the classification boundary of LDA is a hyperplane and explicit formulas exist for the classification error in this case. In the situation where there are more than two classes, the classification boundary is usually complicated and no explicit formulas for the classification errors exist. In this paper, we consider the asymptotic optimality in the high-dimensional settings for a large family of linear classification rules with arbitrary number of classes under the situation of multivariate normal distribution. Our main theorem provides easy-to-check criteria for the asymptotic optimality of a general classification rule in this family as dimensionality and sample size both go to infinity and the number of classes is arbitrary. We establish the corresponding convergence rates. The general theory is applied to the classic LDA and the extensions of two recently proposed sparse LDA methods to obtain the asymptotic optimality. We conduct simulation studies on the extended methods in various settings.
Network control: A rate-distortion perspective

Today's networks are controlled assuming pre-compressed and packetized data. For video, this assumption of data packets abstracts out one of the key aspects - the lossy compression problem. Therefore, first, this paper develops a framework for network control that incorporates both source-rate and source-distortion. Next, it decomposes the network control problem into an application-layer compression control, a transport-layer congestion control and a network-layer scheduling. It is shown that this decomposition is optimal for concave utility functions. Finally, this paper derives further insights from the developed rate-distortion framework by focusing on specific problems.
Dislocation-assisted linear complexion formation driven by segregation

Abstract Atomistic simulations are used to study linear complexion formation at dislocations in a body-centered cubic Fe-Ni alloy. Driven by Ni segregation, precipitation of the metastable B2-FeNi and stable L10-FeNi phases occurs along the compression side of edge dislocations. If the Ni segregation is not intense enough to ensure precipitate growth and coalescence along the dislocation lines, linear complexions in the form of stable nanoscale precipitate arrays are observed. Critical conditions such as global composition and temperature are defined for both linear complexion formation and dislocation-assisted precipitation.
Talking to the crowd: What do people react to in online discussions?

This paper addresses the question of how language use affects community reaction to comments in online discussion forums, and the relative importance of the message vs. the messenger. A new comment ranking task is proposed based on community annotated karma in Reddit discussions, which controls for topic and timing of comments. Experimental work with discussion threads from six subreddits shows that the importance of different types of language features varies with the community of interest.
Local Gradient Estimates for Degenerate Elliptic Equations

This paper is focused on the local interior $W^{1,\infty}$-regularity for weak solutions of degenerate elliptic equations of the form $\text{div}[\mathbf{a}(x,u, \nabla u)] +b(x, u, \nabla u) =0$, which include those of $p$-Laplacian type. We derive an explicit estimate of the local $L^\infty$-norm for the solution's gradient in terms of its local $L^p$-norm. Specifically, we prove \begin{equation*} \|\nabla u\|_{L^\infty(B_{\frac{R}{2}}(x_0))}^p \leq \frac{C}{|B_R(x_0)|}\int_{B_R(x_0)}|\nabla u(x)|^p dx. \end{equation*} This estimate paves the way for our forthcoming work in establishing $W^{1,q}$-estimates (for $q>p$) for weak solutions to a much larger class of quasilinear elliptic equations.
Nuclear-spin dependent parity violation in optically trapped polyatomic molecules

Improved nuclear spin-dependent parity violation measurements will enable experimental determination of poorly known electroweak coupling parameters. Here, we investigate the suitability of optically trapped linear polyatomic molecules as probes of nuclear spin-dependent parity violation. The presence of closely spaced, opposite-parity $$\ell$$ -doublets is a general feature of such molecules, allowing parity-violation-sensitive pairs of levels to be brought to degeneracy in magnetic fields typically 100 times smaller than in diatomics. Assuming laser cooling and trapping of polyatomics at the current state-of-the-art for diatomics, we expect to measure nuclear spin-dependent parity-violating matrix elements iW with 70 times better sensitivity than the current best measurements. Our scheme should allow for 10% measurements of iW in nuclei as light as Be or as heavy as Yb, with averaging times on the order of 10 days and 1 s, respectively. Experimental verification of the Standard Model suffers from large errors when addressing spin-dependent Boson exchange between electrons and quarks. Here, optically trapped linear polyatomic molecules are proposed as probes of nuclear spin-dependent parity violation, exhibiting sensitivity which significantly exceeds the current state-of-the-art.
On the (co)homology of the poset of weighted partitions

We consider the poset of weighted partitions w , in- troduced by Dotsenko and Khoroshkin in their study of a certain pair of dual operads. The maximal intervals of w provide a gen- eralization of the lattice n of partitions, which we show possesses many of the well-known properties of n. In particular, we prove these intervals are EL-shellable, we show that the Mobius invari- ant of each maximal interval is given up to sign by the number of rooted trees on node setf1; 2;:::;ng having a xed number of de- scents, we nd combinatorial bases for homology and cohomology, and we give an explicit sign twisted Sn-module isomorphism from cohomology to the multilinear component of the free Lie algebra with two compatible brackets. We also show that the characteris- tic polynomial of w has a nice factorization analogous to that of n.
Faster Data-access in Large-scale Systems: Network-scale Latency Analysis under General Service-time Distributions

In cloud storage systems with a large number of servers, files (e.g., videos, movies) are typically not stored in single servers. Instead, they are split, replicated (to ensure reliability in case of server malfunction) and stored in different servers. We analyze the mean latency of such a split-and- replicate cloud storage system under general sub-exponential service time distribution, which encapsulates most of the practical heavy-tailed distributions. We present a novel scheduling scheme that utilizes the load-balancing policy of the power of $d (\geq 2)$ choices. Exploiting the double exponential queue length property of this policy ([1]), we obtain tight upper bounds on mean latency. An alternative to split-and-replicate is to use erasure-codes, and recently, it has been observed that they can reduce latency in data access (see [2] for details). We argue that under high redundancy (integer redundancy factor strictly greater than or equal to 2) regime, the mean latency of a coded system is upper bounded by that of a split-and-replicate system (with same replication factor) and the gap between these two is small. For example, when specialized to an exponential service time distribution, our formulation recovers the result of [3], (which uses erasure codes) upto a constant factor. We also validate this claim numerically under different service distributions such as exponential, shift plus exponential and the heavy-tailed Weibull distribution and compare the mean latency to that of an unsplit-replicated system. We observe that the coded system outperforms the unsplit-replication system by at least 20% for all three distributions and all possible arrival request rates. Also, we analyze the tail latency for data centers memoryless servers. Furthermore, we consider the mean latency for an erasure coded system with low redundancy (fractional redundancy factor between 1 and 2), a scenario which is more pragmatic, given the storage constraints ([4]). However under this regime, we restrict ourselves to the special case of exponential service time distribution and use the randomized load balancing policy namely batch-sampling. We obtain an upper bound on mean delay that depends on the order statistics of the queue lengths, which, we further smooth out via a discrete to continuous approximation.
Topological complexity of planar polygon spaces with small genetic code

We determine, within 1, the topological complexity of many planar polygon spaces mod isometry. In all cases considered except for those homeomorphic to real projective space or n-tori, the upper and lower bounds given by dimension and cohomology considerations differ by 1. The spaces which we consider are those whose genetic codes, in the sense of Hausmann and Rodriguez, have a single gene, and its size is ≤ 4. 1. Statement of results The topological complexity, TC(X), of a topological space X is, roughly, the number of rules required to specify how to move between any two points of X. A “rule” must be such that the choice of path varies continuously with the choice of endpoints. (See [3, §4].) We study TC(X) where X = M(`) is the space of equivalence classes of oriented n-gons in the plane with consecutive sides of length `1, . . . , `n, identified under translation, rotation, and reflection. (See, e.g., [4, §6].) Here ` = (`1, . . . , `n) is an n-tuple of positive real numbers. Thus M(`) = {(z1, . . . , zn) ∈ (S) : `1z1 + · · ·+ `nzn = 0}/O(2). We can think of the sides of the polygon as linked arms of a robot, and then TC(X) is the number of rules required to program the robot to move from any configuration to any other. Since permuting the `i’s does not affect the space up to homeomorphism, we may assume `1 ≤ · · · ≤ `n. We assume that `n < `1 + · · · `n−1, so that the space M(`) has more than one point. We also assume that ` is generic, which means that there is Date: September 25, 2015.
Cocycle conjugacy classes of binary shifts

We show that every binary shift on the hyperfinite $II_1$ factor $R$ is cocycle conjugate to at least countably many non-conjugate binary shifts. This holds in particular for binary shifts of infinite commutant index.
Computing the partition function for graph homomorphisms with multiplicities

Abstract We consider a refinement of the partition function of graph homomorphisms and present a quasi-polynomial algorithm to compute it in a certain domain. As a corollary, we obtain quasi-polynomial algorithms for computing partition functions for independent sets, perfect matchings, Hamiltonian cycles and dense subgraphs in graphs as well as for graph colorings. This allows us to tell apart in quasi-polynomial time graphs that are sufficiently far from having a structure of a given type (i.e., independent set of a given size, Hamiltonian cycle, etc.) from graphs that have sufficiently many structures of that type, even when the probability to hit such a structure at random is exponentially small.
Neural Tree Indexers for Text Understanding

Recurrent neural networks (RNNs) process input text sequentially and model the conditional transition between word tokens. In contrast, the advantages of recursive networks include that they explicitly model the compositionality and the recursive structure of natural language. However, the current recursive architecture is limited by its dependence on syntactic tree. In this paper, we introduce a robust syntactic parsing-independent tree structured model, Neural Tree Indexers (NTI) that provides a middle ground between the sequential RNNs and the syntactic treebased recursive models. NTI constructs a full n-ary tree by processing the input text with its node function in a bottom-up fashion. Attention mechanism can then be applied to both structure and node function. We implemented and evaluated a binary tree model of NTI, showing the model achieved the state-of-the-art performance on three different NLP tasks: natural language inference, answer sentence selection, and sentence classification, outperforming state-of-the-art recurrent and recursive neural networks.
Generalization Properties of Learning with Random Features

We study the generalization properties of ridge regression with random features in the statistical learning framework. We show for the first time that $O(1/\sqrt{n})$ learning bounds can be achieved with only $O(\sqrt{n}\log n)$ random features rather than $O({n})$ as suggested by previous results. Further, we prove faster learning rates and show that they might require more random features, unless they are sampled according to a possibly problem dependent distribution. Our results shed light on the statistical computational trade-offs in large scale kernelized learning, showing the potential effectiveness of random features in reducing the computational complexity while keeping optimal generalization properties.
Remarks on Automorphy of Residually Dihedral Representations

We prove automorphy lifting results for geometric representations $\rho:G_F \rightarrow GL_2(\mathcal{O})$, with $F$ a totally real field, and $\mathcal{O}$ the ring of integers of a finite extension of $\mathbb{Q}_p$ with $p$ an odd prime, such that the residual representation $\bar{\rho}$ is totally odd and induced from a character of the absolute Galois group of the quadratic subfield $K$ of $F(\zeta_p)/F$. Such representations fail the Taylor-Wiles hypothesis and the patching techniques to prove automorphy do not work. We apply this to automorphy of elliptic curves $E$ over $F$, when $E$ has no $F$ rational 7-isogeny and such that the image of $G_F$ acting on $E[7]$ normalizes a split Cartan subgroup of $GL_2(\mathbb{F}_7)$.
Multi-Hamiltonian Structure for the Finite Defocusing Ablowitz-Ladik Equation

We study the Poisson structure associated to the defocusing Ablowitz-Ladik equation from a functional-analytical point of view by reexpressing the Poisson bracket in terms of the associated Caratheodory function. Using this expression, we are able to introduce a family of compatible Poisson brackets that form a multi-Hamiltonian structure for the Ablowitz-Ladik equation. Furthermore, we show using some of these new Poisson brackets that the Geronimus relations between orthogonal polynomials on the unit circle and those on the interval define an algebraic and symplectic mapping between the Ablowitz-Ladik and Toda hierarchies. © 2008 Wiley Periodicals, Inc.
r-BTN: Cross-domain Face Composite and Synthesis from Limited Facial Patches

We start by asking an interesting yet challenging question, "If an eyewitness can only recall the eye features of the suspect, such that the forensic artist can only produce a sketch of the eyes (e.g., the top-left sketch shown in Fig. 1), can advanced computer vision techniques help generate the whole face image?" A more generalized question is that if a large proportion (e.g., more than 50%) of the face/sketch is missing, can a realistic whole face sketch/image still be estimated. Existing face completion and generation methods either do not conduct domain transfer learning or can not handle large missing area. For example, the inpainting approach tends to blur the generated region when the missing area is large (i.e., more than 50%). In this paper, we exploit the potential of deep learning networks in filling large missing region (e.g., as high as 95% missing) and generating realistic faces with high-fidelity in cross domains. We propose the recursive generation by bidirectional transformation networks (r-BTN) that recursively generates a whole face/sketch from a small sketch/face patch. The large missing area and the cross domain challenge make it difficult to generate satisfactory results using a unidirectional cross-domain learning structure. On the other hand, a forward and backward bidirectional learning between the face and sketch domains would enable recursive estimation of the missing region in an incremental manner (Fig. 1) and yield appealing results. r-BTN also adopts an adversarial constraint to encourage the generation of realistic faces/sketches. Extensive experiments have been conducted to demonstrate the superior performance from r-BTN as compared to existing potential solutions.
Deep Reinforcement Learning for Dynamic Multichannel Access in Wireless Networks

We consider a dynamic multichannel access problem, where multiple correlated channels follow an unknown joint Markov model and users select the channel to transmit data. The objective is to find a policy that maximizes the expected long-term number of successful transmissions. The problem is formulated as a partially observable Markov decision process with unknown system dynamics. To overcome the challenges of unknown dynamics and prohibitive computation, we apply the concept of reinforcement learning and implement a deep Q-network (DQN). We first study the optimal policy for fixed-pattern channel switching with known system dynamics and show through simulations that DQN can achieve the same optimal performance without knowing the system statistics. We then compare the performance of DQN with a Myopic policy and a Whittle Index-based heuristic through both more general simulations as well as real data trace and show that DQN achieves near-optimal performance in more complex situations. Finally, we propose an adaptive DQN approach with the capability to adapt its learning in time-varying scenarios.
Learning Implicit Generative Models with the Method of Learned Moments

We propose a method of moments (MoM) algorithm for training large-scale implicit generative models. Moment estimation in this setting encounters two problems: it is often difficult to define the millions of moments needed to learn the model parameters, and it is hard to determine which properties are useful when specifying moments. To address the first issue, we introduce a moment network, and define the moments as the network's hidden units and the gradient of the network's output with the respect to its parameters. To tackle the second problem, we use asymptotic theory to highlight desiderata for moments -- namely they should minimize the asymptotic variance of estimated model parameters -- and introduce an objective to learn better moments. The sequence of objectives created by this Method of Learned Moments (MoLM) can train high-quality neural image samplers. On CIFAR-10, we demonstrate that MoLM-trained generators achieve significantly higher Inception Scores and lower Frechet Inception Distances than those trained with gradient penalty-regularized and spectrally-normalized adversarial objectives. These generators also achieve nearly perfect Multi-Scale Structural Similarity Scores on CelebA, and can create high-quality samples of 128x128 images.
An extension operator on bounded domains and applications

In this paper we study a sharp Hardy–Littlewood–Sobolev type inequality with Riesz potential on bounded smooth domains. We obtain the inequality for a general bounded domain $$\Omega $$ and show that if the extension constant for $$\Omega $$ is strictly larger than the extension constant for the unit ball $$B_1$$ then extremal functions exist. Using suitable test functions we show that this criterion is satisfied by an annular domain whose hole is sufficiently small. The construction of the test functions is not based on any positive mass type theorems, neither on the nonflatness of the boundary. By using a similar choice of test functions with the Poisson-kernel-based extension operator we prove the existence of an abstract domain having zero scalar curvature and strictly larger isoperimetric constant than that of the Euclidean ball.
Exploration vs. Exploitation in Team Formation.

An online labor platform faces an online learning problem in matching workers with jobs and using the performance on these jobs to create better future matches. This learning problem is complicated by the rise of complex tasks on these platforms, such as web development and product design, that require a team of workers to complete. The success of a job is now a function of the skills and contributions of all workers involved, which may be unknown to both the platform and the client who posted the job. These team matchings result in a structured correlation between what is known about the individuals and this information can be utilized to create better future matches. We analyze two natural settings where the performance of a team is dictated by its strongest and its weakest member, respectively. We find that both problems pose an exploration-exploitation tradeoff between learning the performance of untested teams and repeating previously tested teams that resulted in a good performance. We establish fundamental regret bounds and design near-optimal algorithms that uncover several insights into these tradeoffs.
Robots as-a-service in cloud computing: Search and rescue in large-scale disasters case study

Internet of Things (IoT) is expected to enable a myriad of applications by interconnecting objects — such as sensors and robots — over the Internet. IoT applications range from healthcare to autonomous vehicles and include disaster management. Enabling these applications in cloud environments requires the design of appropriate IoT Infrastructure-as-a-Service (IoT IaaS) to ease the provisioning of the IoT objects as cloud services. This paper discusses a case study on search and rescue IoT applications in large-scale disaster scenarios. It proposes an IoT IaaS architecture that virtualizes robots (IaaS for robots) and provides them to the upstream applications as-a-Service. Node- and Network-level robots virtualization are supported. The proposed architecture meets a set of identified requirements, such as the need for a unified description model for heterogeneous robots, publication/discovery mechanism, and federation with other IaaS for robots when needed. A validating proof of concept is built and experiments are made to evaluate its performance. Lessons learned and prospective research directions are discussed.
A Diversity-Promoting Objective Function for Neural Conversation Models

Sequence-to-sequence neural network models for generation of conversational responses tend to generate safe, commonplace responses (e.g., I don’t know) regardless of the input. We suggest that the traditional objective function, i.e., the likelihood of output (response) given input (message) is unsuited to response generation tasks. Instead we propose using Maximum Mutual Information (MMI) as the objective function in neural models. Experimental results demonstrate that the proposed MMI models produce more diverse, interesting, and appropriate responses, yielding substantive gains in BLEU scores on two conversational datasets and in human evaluations.
Operations on the secondary Hochschild cohomology

We show that the secondary Hochschild cohomology associated to a triple $(A,B,\varepsilon)$ has several of the properties of the usual Hochschild cohomology. Among others, we prove the existence of the cup and Lie products, discuss the connection with extensions of $B$-algebras, and give a Hodge type decomposition of the secondary Hochschild cohomology.
Reversible logic synthesis by quantum rotation gates

A rotation-based synthesis framework for reversible logic is proposed. We develop a canonical representation based on binary decision diagrams and introduce operators to manipulate the developed representation model. Furthermore, a recursive functional bidecomposition approach is proposed to automatically synthesize a given function. While Boolean reversible logic is particularly addressed, our framework constructs intermediate quantum states that may be in superposition, hence we combine techniques from reversible Boolean logic and quantum computation. The proposed approach results in quadratic gate count for multiple-control Toffoli gates without ancillae, linear depth for quantum carry-ripple adder, and quasilinear size for quantum multiplexer.
When can Multi-Site Datasets be Pooled for Regression? Hypothesis Tests, $\ell_2$-consistency and Neuroscience Applications

Many studies in biomedical and health sciences involve small sample sizes due to logistic or financial constraints. Often, identifying weak (but scientifically interesting) associations between a set of predictors and a response necessitates pooling datasets from multiple diverse labs or groups. While there is a rich literature in statistical machine learning to address distributional shifts and inference in multi-site datasets, it is less clear when such pooling is guaranteed to help (and when it does not) - independent of the inference algorithms we use. In this paper, we present a hypothesis test to answer this question, both for classical and high dimensional linear regression. We precisely identify regimes where pooling datasets across multiple sites is sensible, and how such policy decisions can be made via simple checks executable on each site before any data transfer ever happens. With a focus on Alzheimer's disease studies, we present empirical results showing that in regimes suggested by our analysis, pooling a local dataset with data from an international study improves power.