cssi/SciSciGPT-SciSciNet huggingface dataset:
Synthesis of several pyrimidine l-nucleoside analogues as potential antiviral agents

Abstract β- l -5-Iodo-2′-deoxyuridine (β- l -IUdR, 7) and 1-[(β- l - arabinofuranosyl )-E-5-(2- bromovinyl)]uracil (β- l -BV-ara-U, 10) have been synthesized via a multi-step synthesis from l -arabinose. 2′,3′-Dideoxy-β- l -5-azacytidine (18), 2′,3′-dideoxy-β- l -2-thiocytidine (20) and their respective α-anomers, compounds 19 and 21, also were synthesized by direct coupling of 1-O- acetyl -5-O-(tert- butyldimethylsilyl )-2,3-dideoxy- l - ribofuranose (13) with the corresponding silylated bases, in the presence of EtAlCl2 in CH2Cl2, followed by separation of the α- and β-isomers and deblocking of the 5′-protecting groups. In addition, 2′,3′-dideoxy-β- l -5-fluorocytidine (34), a potent anti-HIV and anti-HBV agent, was synthesized by an alternative methodology from 2′,3′-dideoxy-β- l -5-fluorouridine (31) via a 4-triazolylpyrimidinone intermediate. These l -nucleoside analogues were tested in vitro against HIV, HBV, HSV-1, and HSV-2. Among these compounds, 2′,3′-dideoxy-β- l -5-azacytidine (18) was found to show significant activity against HBV in vitro at approximately the same level as 2′,3′-dideoxy-β- d -cytidine (ddC), which is a known potent anti-HBV agent.
Matrices from vegetable oils, cashew nut shell liquid, and other relevant systems for biocomposite applications

The partial replacement of petroleum-derived plastics and composites by novel bio-based materials from inexpensive, renewable, natural resources has the potential to greatly impact the plastics, coatings, and composites industries. Natural starting materials are usually abundant and renewable on a time scale many orders of magnitude smaller than petroleum. These characteristics, in combination with good mechanical properties, make the design of bio-based composites an interesting strategy for lowering the environmental impact of the plastics and composites industries while maintaining economical competitiveness. The present review will focus on the progress made over the last decade in the development of a select group of bio-based matrices for biocomposite applications. The text is organized into sections that describe a matrix system and its many reinforcements. The matrices covered in this review include composites from vegetable oils, cashew nut shell liquid, and a brief overview of other currently academically relevant bio-based matrix systems, such as polysaccharides, polylactide (PLA), polyhydroxyalkanoates (PHAs), proteins, and lignin.
A Within Firm Analysis of Current and Expected Future Audit Lag Determinants

This paper reports the impediments identified by practicing auditors that keep them from significantly reducing the time lag between closing and issuing their report. We obtain these impediments by surveying the U.S. assurance partners of an international audit firm. Our results suggest that lack of sufficient personnel resources, both with the client and the audit firm hindered a significant reduction in prior audit report lags. In addition, the partners believe that before audit report lags are signifi‐cantly reduced, the clients' and the auditor's mindset must change to accommodate a new audit approach. Even if the mindset of both parties is changed, the partners believe the skill‐set of auditors must improve and the flexibility of the scheduling process must increase. Implications of the results for continuous auditing are also discussed.
Cheap talk can matter in bargaining

This paper describes an intuitive way in which cheap talk can matter in a twostage bargaining game in which talk may be followed by serious negotiation. The intuition that all buyers would claim to have low reservation prices is incorrect in our model. Instead, if good-faith participation is endogenously determined then the parties can use talk to trade off bargaining position against the probability of continued negotiation. Our cheap-talk equilibrium features bargaining behavior that could not be equilibrium behavior in the absence of talk.
Stability of exponential utility maximization with respect to market perturbations

We investigate the continuity of expected exponential utility maximization with respect to perturbation of the Sharpe ratio of markets. By focusing only on continuity, we impose weaker regularity conditions than those found in the literature. Specifically, for markets of the form S = M + RdhMi, we require a uniform bound on the norm of � · M in a suitable bmo space.
Performance analysis of a Ge/Si core/shell nanowire field-effect transistor.

We ana/lyze the performance of a recently reported Ge/Si core/shell nanowire transistor using a semiclassical, ballistic transport model and an sp3d5s* tight-binding treatment of the electronic structure. Comparison of the measured performance of the device with the effects of series resistance removed to the simulated result assuming ballistic transport shows that the experimental device operates between 60 and 85% of the ballistic limit. For this ∼15 nm diameter Ge nanowire, we also find that 14−18 modes are occupied at room temperature under ON-current conditions with ION/IOFF = 100. To observe true one-dimensional transport in a 〈110〉 Ge nanowire transistor, the nanowire diameter would have to be less than about 5 nm. The methodology described here should prove useful for analyzing and comparing on a common basis nanowire transistors of various materials and structures.
Political Economy of Property Tax Reform: Hawaii's Experiment with Split-Rate Property Taxation

Economic theory suggests that switching from a general property tax to a split-rate tax increases land use efficiency and stimulates urban core development while preserving the environment and reducing urban sprawl. Under split-rate property taxation, land is typically taxed at a significantly higher rate than improvements. Beginning in 1965 Hawaii experimented with a statewide split-rate property tax system to encourage economic growth and effect land reform. The experiment was ended in 1977. Following the transfer of property taxing powers to the counties in 1978, some counties brought back the split-rate property tax at times. Since 2006, Kauai County has adopted the unusual practice of taxing improvements at a higher rate than land for most property classes. This article chronicles and explains the rationale behind Hawaii's state and county experiments with split-rate property taxation.
Fast unitary heap transforms: theory and application in cryptography

This paper presents a novel approach to compose discrete unitary transforms that are induced by input signals which are considered to be generators of the transforms. Properties and examples of such transforms, which we call the discrete heap transforms are given. The transforms are fast, because of a simple form of decomposition of their matrices, and they can be applied for signals of any length. Fast algorithms of calculation of the direct and inverse heap transforms do not depend on the length of the processed signals. In this paper, we demonstrate the applications of the heap transforms for transformation and reconstruction of one-dimensional signals and two-dimensional images. The heap transforms can be used in cryptography, since the generators can be selected in different ways to make the information invisible; these generators are keys for recovering information. Different examples of generating and applying heap transformations over signals and images are considered.© (2009) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Incremental LL(1) parsing in language-based editors

This paper introduces an efficient incremental LL(1) parsing algorithm for use in language-based editors that use the structure recognition approach. It is designed to parse user input at intervals of very small granularity and to limit the amount of incremental parsing needed when changes are made internal to the editing buffer. The algorithm uses the editing focus as a guide in restricting parsing. It has been implemented in the Fred language-based editor. >
Differential Fertility, Human Capital, and Development

Using micro-data from 48 developing countries, this paper studies changes in crosssectional patterns of fertility and child investment over the course of the demographic transition. Before 1960, children from larger families obtained more education, in large part because they had richer and more educated parents. By century’s end, these patterns had reversed. Consequently, fertility differentials by income and education historically raised the average education of the next generation, but they now reduce it. While the reversal is unrelated to changes in GDP per capita, women’s work, sectoral composition, or health, roughly half is attributable to rising aggregate education in the parents’ generation. The results support a model in which rising skill returns lowered the minimum income at which parents invest in education.
Optimal Nonblocking Directed Control of Discrete Event Systems

For the control of discrete event systems, the notion of directed control refines that of supervisory control. A directed controller is one that selects at most one controllable event to be enabled at any state (without disabling any uncontrollable event), which is in fact how a discrete event control is implemented. In contrast, a supervisory controller computes a maximal allowable set of controllable events at each state, leaving undecided exactly which controllable event should be enabled. In previous works, we developed a framework for the computation of optimal directed controllers and a polynomial synthesis algorithm for acyclic plants. In this paper, we present a novel synthesis approach for general plants, i.e., plants with or without cycles, thus providing a complete solution to the optimal directed control problem. The complexity of the approach remains polynomial in the size of plant.
Optimal infinite-horizon control for probabilistic Boolean networks

External control of a genetic regulatory network is used for the purpose of avoiding undesirable states, such as those associated with disease. Heretofore, intervention has focused on finite-horizon control, i.e., control over a small number of stages. This paper considers the design of optimal infinite-horizon control for context-sensitive probabilistic Boolean networks (PBNs). It can also be applied to instantaneously random PBNs. The stationary policy obtained is independent of time and dependent on the current state. This paper concentrates on discounted problems with bounded cost per stage and on average-cost-per-stage problems. These formulations are used to generate stationary policies for a PBN constructed from melanoma gene-expression data. The results show that the stationary policies obtained by the two different formulations are capable of shifting the probability mass of the stationary distribution from undesirable states to desirable ones.
Enantioselective synthesis of 1,1,1-trifluoroalkan-2-ols by ruthenium-catalyzed hydrogenation

Abstract The highly enantioselective synthesis of 1,1,1-trifluoroalkan-2-ols has been achieved by hydrogenating 1,1,1-trifluoroalkan-2-one enol acetates in the presence of chiral ruthenium catalysts. An enol acetate, 2-acetoxy-3,3,3-trifluoro-1-(phenylthio)propene, can be successfully transformed into enantiomerically pure trifluorolactic acid.
Bright Source Subtraction Requirements for Redshifted 21 cm Measurements

The H I 21 cm transition line is expected to be an important probe into the cosmic dark ages and epoch of reionization. Foreground source removal is one of the principal challenges for the detection of this signal. This paper investigates the extragalactic point source contamination and how accurately bright sources (≳ Jy) must be removed in order to detect 21 cm emission with upcoming radio telescopes such as the Murchison Widefield Array. We consider the residual contamination in 21 cm maps and power spectra due to position errors in the sky model for bright sources, as well as frequency-independent calibration errors. We find that a source position accuracy of 0.1 arcsec will suffice for detection of the H I power spectrum. For calibration errors, 0.05% accuracy in antenna gain amplitude is required in order to detect the cosmic signal. Both sources of subtraction error produce residuals that are localized to small angular scales, k⊥ ≳ 0.05 Mpc^(–1), in the two-dimensional power spectrum.
Limited feedback-based block diagonalization for the MIMO broadcast channel

Block diagonalization is a linear preceding technique for the multiple antenna broadcast (downlink) channel that involves transmission of multiple data streams to each receiver such that no multi-user interference is experienced at any of the receivers. This low-complexity scheme operates only a few dB away from capacity but requires very accurate channel knowledge at the transmitter. We consider a limited feedback system where each receiver knows its channel perfectly, but the transmitter is only provided with a finite number of channel feedback bits from each receiver. Using a random quantization argument, we quantify the throughput loss due to imperfect channel knowledge as a function of the feedback level. The quality of channel knowledge must improve proportional to the SNR in order to prevent interference-limitations, and we show that scaling the number of feedback bits linearly with the system SNR is sufficient to maintain a bounded rate loss. Finally, we compare our quantization strategy to an analog feedback scheme and show the superiority of quantized feedback.
Social Sharing of Information Goods: Implications for Pricing and Profits

Social sharing of information goods---wherein a single good is purchased and shared through a network of acquaintances such as friends or coworkers---is a significant concern for the providers of these goods. The effect of social sharing on firm pricing and profits depends critically on two elements: the structure of the underlying consumer network and the mechanism used by groups to decide whether to purchase at a given price. We examine the effect of social sharing under different network structures (decentralized, centralized, and complete), which reflect a range of market conditions. Moreover, we draw from the mechanism design literature to examine several approaches to group decision making. Our results suggest that a firm can benefit from increased social sharing if the level of sharing is already high, enabling a pricing strategy targeted primarily at sharing groups rather than individuals. However, the point at which sharing becomes marginally beneficial for a firm depends on both the distribution of group sizes (which derives from the network structure) and the group decision mechanism. Additional insights are obtained when we extend the model to capture homophily in group formation and the potential that a subset of consumers will never share for ethical reasons.
TENSE TREES AS THE "FINE STRUCTURE" OF DISCOURSE

We present a new compositional tense-aspect deindexing mechanism that makes use of tense trees as components of discourse contexts. The mechanism allows reference episodes to be correctly identified even for embedded clauses and for discourse that involves shifts in temporal perspective, and permits deindexed logical forms to be automatically computed with a small number of deindexing rules.
Entrepreneurial Risk Taking in Family Firms

Family firms are widely recognized as a major source of technological innovation and economic progress. Yet, over time, some family firms become conservative and unwilling to take the risks associated with entrepreneurial activities. Adopting a broad definition of entrepreneurial risk taking, this study uses agency theory to highlight key correlates of risk taking among 209 U.S. manufacturing family firms. The results show that family ownership and involvement promote entrepreneurship, whereas the long tenures of CEO founders have the opposite effect. These results urge managers to capitalize on the skills and talents of their family members in promoting entrepreneurship and selective venturing into new market arenas.
B-alkyl suzuki-miyaura cross-coupling reactions with air-stable potassium alkyltrifluoroborates.

The palladium-catalyzed cross-coupling reaction of substituted potassium alkyltrifluoroborates with aryl halides and aryl triflates proceeds readily with moderate to good yields. The potassium alkyltrifluoroborates 1, 2, and 3a-e were easily synthesized and obtained as air-stable crystalline solids that can be stored for long periods of time. All of the cross-couplings proceed under the same reaction conditions using PdCl(2)(dppf).CH(2)Cl(2) as catalyst in THF-H(2)O in the presence of 3 equiv of Cs(2)CO(3) as base.
Stochastic utility-efficient programming of organic dairy farms

Opportunities to make sequential decisions and adjust activities as a season progresses and more information becomes available characterise the farm management process. In this paper, we present a discrete stochastic two-stage utility efficient programming model of organic dairy farms, which includes risk aversion in the decision maker’s objective function as well as both embedded risk (stochastic programming with recourse) and non-embedded risk (stochastic programming without recourse). Historical farm accountancy data and subjective judgements were combined to assess the nature of the uncertainty that affects the possible consequences of the decisions. The programming model was used within a stochastic dominance framework to examine optimal strategies in organic dairy systems in Norway.
Synthesis of a Remarkably Stable Dehydro[14]annulene

The substituents at the peri positions of dehydro[14]annulenes 1 have a dramatic effect on the stability of these macrocycles, and lead to derivatives that are stable even at elevated temperatures (up to 190°C).
THE GREEN BANK TELESCOPE H II REGION DISCOVERY SURVEY. IV. HELIUM AND CARBON RECOMBINATION LINES

The Green Bank Telescope Hii Region Discovery Survey (GBT HRDS) found hundreds of previously unknown Galactic regions of massive star formation by detecting hydrogen radio recombination line (RRL) emission from candidate Hii region targets. Since the HRDS nebulae lie at large distances from the Sun, they are located in previously unprobed zones of the Galactic disk. Here, we derive the properties of helium and carbon RRL emission from HRDS nebulae. Our target sample is the subset of the HRDS that has visible helium or carbon RRLs. This criterion gives a total of 84 velocity components (14% of the HRDS) with helium emission and 52 (9%) with carbon emission. For our highest quality sources, the average 4 He + /H + abundance ratio by number, � y + � ,i s 0.068 ±0.023(1σ). This is the same ratio as that measured for the sample of previously known Galactic Hiiregions. Nebulae without detected helium emission give robust y + upper limits. There are 5 RRL emission components with y + less than 0.04 and another 12 with upper limits below this value. These Hii regions must have either a very low 4 He abundance or contain a significant amount of neutral helium. The HRDS has 20 nebulae with carbon RRL emission but no helium emission at its sensitivity level. There is no correlation between the carbon RRL parameters and the 8 μm mid-infrared morphology of these nebulae.
Evaluating and Extending Latent Methods for Link-Based Classification

Data describing networks such as social networks, citation graphs, hypertext systems, and communication networks is becoming increasingly common and important for analysis. Research on link-based classification studies methods to leverage connections in such networks to improve accuracy. Recently, a number of such methods have been proposed that first construct a set of latent features or links that summarize the network, then use this information for inference. Some work has claimed that such latent methods improve accuracy, but has not compared against the best non-latent methods. In response, this article provides the first substantial comparison between these two groups. Using six real datasets, a range of synthetic data, and multiple underlying models, we show that (non-latent) collective inference methods usually perform best, but that the dataset’s label sparsity, attribute predictiveness, and link density can dramatically affect the performance trends. Inspired by these findings, we introduce three novel algorithms that combine a latent construction with a latent or non-latent method, and demonstrate that they can sometimes substantially increase accuracy.
Asynchronous Amazon forest canopy phenology indicates adaptation to both water and light availability

Amazon forests represent nearly half of all tropical vegetation biomass and, through photosynthesis and respiration, annually process more than twice the amount of estimated carbon (CO2) from fossil fuel emissions. Yet the seasonality of Amazon canopy cover, and the extent to which seasonal fluctuations in water availability and photosynthetically available radiation influence these processes, is still poorly understood. Implementing six remotely sensed data sets spanning nine years (2003–2011), with reported field and flux tower data, we show that southern equatorial Amazon forests exhibit a distinctive seasonal signal. Seasonal timing of water availability, canopy biomass growth and net leaf flush are asynchronous in regions with short dry seasons and become more synchronous across a west-to-east longitudinal moisture gradient of increasing dry season. Forest cover is responsive to seasonal disparities in both water and solar radiation availability, temporally adjusting net leaf flush to maximize use of these generally abundant resources, while reducing drought susceptibility. An accurate characterization of this asynchronous behavior allows for improved understanding of canopy phenology across contiguous tropical forests and their sensitivity to climate variability and drought.
Direct versus Indirect Colonial Rule in India: Long-Term Consequences

Abstract This paper compares economic outcomes across areas in India that were under direct British colonial rule with areas that were under indirect colonial rule. Controlling for selective annexation using a specific policy rule, I find that areas that experienced direct rule have significantly lower levels of access to schools, health centers, and roads in the postcolonial period. I find evidence that the quality of governance in the colonial period has a significant and persistent effect on postcolonial outcomes.
Effects of stream map resolution on measures of riparian buffer distribution and nutrient retention potential

Riparian ecosystems are interfaces between aquatic and terrestrial environments recognized for their nutrient interception potential in agricultural landscapes. Stream network maps from a broad range of map resolutions have been employed in watershed studies of riparian areas. However, map resolution may affect important attributes of riparian buffers, such as the connectivity between source lands and small stream channels missing in coarse resolution maps. We sought to understand the influence of changing stream map resolution on measures of the river network, near-stream land cover, and riparian metrics. Our objectives were: (1) to evaluate the influence of stream map resolution on measures of the stream network, the character and extent of near-stream zones, and riparian metrics; (2) to compare patterns of variation among different physiographic provinces; and (3) to explore how predictions of nutrient retention potential might be affected by the resolution of a stream map. We found that using fine resolution stream maps significantly increased our estimates of stream order, drainage density, and the proportion of watershed area occurring near a stream. Increasing stream map resolution reduced the mean distance to source areas as well as mean buffer width and increased the frequency of buffer gaps. Measures of percent land cover within 100 m of streams were less sensitive to stream map resolution. Overall, increasing stream map resolution led to reduced estimates of nutrient retention potential in riparian buffers. In some watersheds, switching from a coarse resolution to a fine resolution stream map completely changed our perception of a stream network from well buffered to largely unbuffered. Because previous, broad-scale analyses of riparian buffers used coarse-resolution stream maps, those studies may have overestimated landscape-level buffer prevalence and effectiveness. We present a case study of three watersheds to demonstrate that interactions among stream map resolution and land cover patterns make a dramatic difference in the perceived ability of riparian buffers to ameliorate effects of agricultural activities across whole watersheds. Moreover, stream map resolution affects inferences about whether retention occurs in streams or riparian zones.
Relativity in the future of engineering

Improvements in clock technology make it possible to develop extremely accurate timing, ranging, navigation, and communications systems. Three relativistic effects, time dilation, the Sagnac effect, and gravitational frequency shifts, must be accounted for in order for modern systems to work properly. These effects are related in a nonmathematical way to fundamental relativity principles: constancy of the speed of light, and the principle of equivalence. Examples of current and future engineering applications are discussed, such as in the Global Positioning System, in time synchronization systems, communications, and geodesy. >
Improving Asynchronous Partial Overlay

Since its creation, the Asynchronous Partial Overlay (APO) protocol has received a great deal of attention because of its non-traditional approach to solving Distributed Constraint Satisfaction Problems (DCSPs). Its introduction led investigators to question the very definition of the word "distributed" and has subsequently inspired the community to create improved metrics for parallel computation, enhanced testing procedures, and most importantly new DCSP algorithms. These advances have raised concerns about APO's parallel efficiency by showing that, in some cases, APO performs very poorly compared to protocols such as Asynchronous Forward Checking, Conflict-directed Back jumping (AFC-CBJ). In addition, APO's soundness and completeness were brought into question when it was discovered that, under certain conditions, stale state information could cause the protocol's distributed locking mechanism to fail. This work revisits APO by reengineering the protocol to simplify it and increase its parallelism while ensuring its soundness and completeness. It also vastly improves the parallel efficiency of APO by replacing its central solver with a variant of the Forward Checking, Conflict-directed Back jumping (FC-CBJ) algorithm that is specifically tuned to complement the heuristic strategies used by APO to limit its centralization. This new version of APO is then evaluated against the AFC-CBJ protocol using random instances of both DCSPs and distributed 3-coloring problems. The end result is a protocol that is several orders of magnitude faster than the original APO, uses less messages, is more private, and outperforms the AFC-CBJ protocol in nearly every case tested.
Efficient Spatial Pattern Analysis for Variation Decomposition Via Robust Sparse Regression

In this paper, we propose a new technique to achieve accurate decomposition of process variation by efficiently performing spatial pattern analysis. We demonstrate that the spatially correlated systematic variation can be accurately represented by the linear combination of a small number of templates. Based on this observation, an efficient sparse regression algorithm is developed to accurately extract the most adequate templates to represent spatially correlated variation. In addition, a robust sparse regression algorithm is proposed to automatically remove measurement outliers. We further develop a fast numerical algorithm that may reduce the computational time by several orders of magnitude over the traditional direct implementation. Our experimental results based on both synthetic and silicon data demonstrate that the proposed sparse regression technique can capture spatially correlated variation patterns with high accuracy and efficiency.
A distributed object infrastructure for interaction and steering

This paper presents the design, implementation and experimental evaluation of DIOS (Distributed Interactive Object Substrate), an interactive object infrastructure to enable the runtime monitoring, interaction and computational steering of parallel and distributed applications. DIOS enables application objects (data structures, algorithms) to be enhanced with sensors and actuators so that they can be interrogated and controlled. Application objects may be distributed (spanning many processors) and dynamic (be created, deleted, changed or migrated). Furthermore, DIOS provides a control network that interconnects the interactive objects in a parallel/distributed application and enables external discovery, interrogation, monitoring and manipulation of these objects at runtime. DIOS is currently being used to enable interactive visualization, monitoring and steering of a wide range of scientific applications, including oil reservoir, compressible turbulence and numerical relativity simulations. Copyright © 2003 John Wiley & Sons, Ltd.
Dynamics of an isolated blob in the presence of the X-point

The interplay of X-point shearing and axial plasma redistribution along a moving flux tube is discussed. Blobs limited to the main scrape-off-layer and blobs entirely confined in the divertor region are identified. A strong effect of the radial tilt of the divertor plate on "divertor" blobs is found.
Evaluating cache coherent shared virtual memory for heterogeneous multicore chips

Although current homogeneous chips tightly couple the cores with cache-coherent shared virtual memory (CCSVM), this is not the communication paradigm used by any current heterogeneous chip. In this paper, we present a CCSVM design for a CPU/GPU chip, as well as an extension of the pthreads programming model for programming this HMC. We experimentally compare CCSVM/xthreads to a state-of-the-art CPU/GPU chip from AMD that runs OpenCL software. CCSVM's more efficient communication enables far better performance and far fewer DRAM accesses.
Formation of Modified Cytosine Residues in the Presence of Depurinated DNA

[Chemical reaction: See text] Depurination is an important degradation pathway for antisense phosphorothioate oligonucleotides under conditions of thermal stress. We present evidence showing that depurinated oligonucleotides react with cytosine-containing sequences giving products containing a 6-(2-deoxy-beta-D-erythro-pentofuranosyl)-3-(2-oxopropyl)imidazo[1,2-c]pyrimidin-5(6H)-one residue. Further, we demonstrate that the same product is formed upon treatment of 2'-deoxycytidine with 4-oxo-2-pentenal, the latter being an expected byproduct of serial elimination reactions at apurinic sites. In addition to being important for synthetic oligonucleotides, apurinic site formation in cellular DNA is a common occurrence. Because repair of these sites can result in the production of 4-oxo-2-pentenal, it is interesting to speculate whether 6-(2-deoxy-beta-D-erythro-pentofuranosyl)-3-(2-oxopropyl)imidazo[1,2-c]pyrimidin-5(6H)-one residues can form in vivo.
Reducing oligosaccharides via glycal assembly: on the remarkable stability of anomeric hydroxyl groups to global deprotection with sodium in liquid ammonia

Abstract Several partially benzylated 1-hydroxy sugars were rapidly deprotected by sodium/liquid ammonia. The terminal hemiketal linkage of the substrates remained intact under these conditions and does not generate ring-opened alditols. Peracetylated glucose and glucosamine derivatives were obtained in 64–79% isolated yields.
Assemblage of the vertical: commercial drones and algorithmic life

Abstract. This paper takes up the increasingly popular topic of drones – including unmanned aerial vehicles (UAVs), small unmanned aerial systems (sUAS), remotely piloted aircraft (RPA), and a vast panoply of commercial drones and copters – to argue that our analysis should lie not so much on drones as objects, but as assemblages of the vertical. Drones, I argue, constitute a socio-technical assemblage of the sky and vertical space, which means that our focus should be not (only) on their technological development and capacities but also on their effects and affects. The latter of these include increasing algorithmic data collection and circulation that follow anticipatory logics.
Stable Flocking of Multiple Inertial Agents on Balanced Graphs

In this note, we consider the flocking of multiple agents which have significant inertias and evolve on a balanced information graph. Here, by flocking, we mean that all the agents move with a common velocity while keeping a certain desired internal group shape. We first show that flocking algorithms that neglect agents' inertial effect can cause unstable group behavior. To incorporate this inertial effect, we use the passive decomposition, which decomposes the closed-loop group dynamics into two decoupled systems: a shape system representing the internal group shape and a locked system describing the motion of the center-of-mass. Then, analyzing the locked and shape systems separately with the help of graph theory, we propose a provably stable flocking control law, which ensures that the internal group shape is exponentially stabilized to a desired one, while all the agents' velocities converge to the centroid velocity that is also shown to be time-invariant. This result still holds for slow-switching balanced information graphs. Simulation is performed to validate the theory.
What Would Edmonds Do? Augmenting Paths and Witnesses for Degree-Bounded MSTs

Given a graph and degree upper bounds on vertices, the BDMST problem requires us to find a minimum cost spanning tree respecting the given degree bounds. This problem generalizes the Travelling Salesman Path Problem (TSPP), even in unweighted graphs, and so we expect that it is necessary to relax the degree constraints to get efficient algorithms. Konemann and Ravi (Proceedings of the Thirty Second Annual ACM Symposium on Theory of Computing, pp. 537–546, 2000; Proceedings of the Thirty-Fifth ACM Symposium on Theory of Computing, pp. 389–395, 2003) give bicriteria approximation algorithms for the problem using local search techniques of Fischer (Technical Report 14853, Cornell University, 1993). Their algorithms find solutions which make a tradeoff of the approximation factor for the cost of the resulting tree against the factor by which degree constraints are violated. In particular, they give an algorithm which, for a graph with a spanning tree of cost C and degree B, and for parameters b,w>1, produces a tree whose cost is at most wC and whose degree is at most $\frac{w}{w-1}bB+\log_{b}n.$ A primary contribution of Konemann and Ravi is to use a Lagrangean relaxation to formally relate the BDMST problem to what we call the MDMST problem, which is the problem of finding an MST of minimum degree in a graph. In their solution to the MDMST problem, they make central use of a local-search approximation algorithm of Fischer. In this paper, we give the first approximation algorithms for the BDMST problem—both our algorithms find trees of optimal cost. We achieve this improvement using a primal-dual cost bounding methodology from Edmonds’ weighted matching algorithms which was not previously used in this context. In order to follow Edmonds’ approach, we develop algorithms for a variant of the MDMST problem in which there are degree lower bound requirements. This variant may be of independent interest; in particular, our results extend to a generalized version of the BDMST problem in which both upper and lower degree bounds are given. First we give a polynomial-time algorithm that finds a tree of optimal cost and with maximum degree at most $\frac{b}{2-b}B+O(\log_{b}n)$for any b∈(1,2). We also give a quasi-polynomial-time approximation algorithm which produces a tree of optimal cost C and maximum degree at most B+O(log n/log log n). That is, the error is additive as well as restricted just to the degree. This further improvement in degree is obtained by using augmenting-path techniques that search over a larger solution space than Fischer’s local-search algorithm.
The Zoological Connection: Animal-Related Human Behavior

Sociologists have been derelict in their failure to address the zoological component in human interaction and attendant social systems. Even a cursory examination of our language and other cultural inventory reveals a discernible animal influence on our social lives and behavior which has been largely neglected by sociological researchers. In this connection, several investigative directions in studying animal-related human behavior would seem to hold particular productive research promise. Research might be profitably directed at such topics as animals as social problems, ideological conflicts involving animals, the human-animal interface attendant to work, the animal as surrogate human, and animal-related crime and deviancy. As sociologists interested in understanding human behavior in all of its vagaries, we might be welladvised to add animal to the lexicon of our discipline, and so turn our research attention to the "zoological connection." We might accordingly come to perceive whole new vistas of behavioral linkages and social causation. Sociologists, among the practitioners in most of the behavioral sciences and many of the humanities, have been singularly derelict in their failure to address the zoological component in human interaction and attendant social systems. We have tended not to recognize, to overlook, to ignore, or to neglect (some critics might say deservedly so) the influence of animals, or their import for, our social behavior, our relationships with other humans, and the directions which our social enterprise often takes. Humanists have long explored the presence, function, and symbolism of animals in art, literature, and theater at various periods of history (as illustrations, see Antal and Harthan; Clark; Hastings; McSpadden; Toynbee; Zuelke). Social historians in both trade and scholarly treatises have addressed the relationship of man and various beasts in myriad social contexts, and including a wide variety of species, such as the wolf (Lopez), *Presidential address delivered at the annual meeting of the Southern Sociological Society, 1979. Many of my colleagues in the Department of Sociology at VPI & SU made valuable suggestions for this paper for which I would like to thank them. C 1979, University of North Carolina Press. 0037-7732/79/020399-21$02.30
Straightforward Synthesis of Panaxytriol: An Active Component of Red Ginseng

A total synthesis of (3R,9R,10R)-panaxytriol (1) was accomplished enantioselectively (40% overall yield; 30% for the longest sequence). A key step was a Cadiot-Chodkiewicz cross-coupling reaction on two fragments containing, in the aggregate, three unprotected hydroxyl groups. One fragment was synthesized by a highly enantioselective reduction of an enynone. The other arose from a highly enantioselective dihydroxylation of an allylic alcohol.
Synthesis of highly functionalized pyrrolidines via a mild one-pot, three-component 1,3-dipolar cycloaddition process.

A simple and efficient one-pot, three-component synthesis of highly functionalized pyrrolidines via cascade imine → azomethine ylide → 1,3-dipolar cycloadditions is reported. Admixing a variety of ...
High-confidence predictions under adversarial uncertainty

We study the setting in which the bits of an unknown infinite binary sequence x are revealed sequentially to an observer. We show that very limited assumptions about x allow one to make successful predictions about unseen bits of x. First, we study the problem of successfully predicting a single 0 from among the bits of x. In our model, we have only one chance to make a prediction, but may do so at a time of our choosing. This model is applicable to a variety of situations in which we want to perform an action of fixed duration, and need to predict a “safe” time-interval to perform it.Letting Nt denote the number of 1s among the first t bits of x, we say that x is “e-weakly sparse” if lim inf (Nt/t) ≤ e. Our main result is a randomized algorithm that, given any e-weakly sparse sequence x, predicts a 0 of x with success probability as close as desired to 1 - e. Thus, we can perform this task with essentially the same success probability as under the much stronger assumption that each bit of x takes the value 1 independently with probability e.We apply this result to show how to successfully predict a bit (0 or 1) under a broad class of possible assumptions on the sequence x. The assumptions are stated in terms of the behavior of a finite automaton M reading the bits of x. We also propose and solve a variant of the well-studied “ignorant forecasting” problem. For every e>0, we give a randomized forecasting algorithm Se that, given sequential access to a binary sequence x, makes a prediction of the form: “A p fraction of the next N bits will be 1s.” (The algorithm gets to choose p, N, and the time of the prediction.) For any fixed sequence x, the forecast fraction p is accurate to within ±e with probability 1 - e.
New approaches to side-chain fluorinated bioimidazoles: 4-alkynylimidazoles as substrates for fluorination

Abstract 4-Alkynylimidazoles have been prepared and their behavior as substrates for “FBr” addition (NBS+Et3N·3HF) have been studied. Facile Markownikov addition to ethylnylimidazole 2 gave fluorobromoolefin 9a, a potential synthon for the 2-imidazolyl-2-fluoro-1-ethenyl moiety. Reaction of the lithium salt of 2 with diethyl oxalate produced imidazolylpropynoic ester 3b. However, because of the deactivating effect of the ester functionality, all attempts to carry out addition of “FBr” to 3b met with failure. Reduction of the ester gave the hydroxymethyl-substituted acetylene 4. Addition of “FBr” to this substrate and reductive removal of bromine from the product produced fluoroolefins 12, precursors to E- and Z-β-fluorourocanic acids. The same fluoroolefins can be used as intermediates in the synthesis of β-fluorohistidinols.
Cross-sectional comparison of critically ill pediatric patients across hospitals with various levels of pediatric care

Background Inpatient administrative data sources describe the care provided to hospitalized children. The Kids’ Inpatient Database (KID) provides nationally representative estimates, while the Pediatric Health Information System (PHIS, a consortium of pediatric facilities) derives more detailed information from revenue codes. The objective was to contextualize a diagnosis and procedure-based definition of critical illness to a revenue-based definition; then compare it across hospitals with different levels of pediatric care.
High-Temperature Salt Flux Crystal Growth of New Lanthanide Molybdenum Oxides, Ln5Mo2O12 Ln = Eu, Tb, Dy, Ho, and Er: Magnetic Coupling within Mixed Valent Mo(IV/V) Rutile-Like Chains

Five new lanthanide molybdenum oxides containing mixed valent Mo(IV/V) rutile-like chains, Ln5Mo2O12 Ln = Eu, Tb, Dy, Ho, and Er, were prepared utilizing a high-temperature molten salt flux synthesis involving an in situ reduction utilizing metallic reducing agents. All five compounds were structurally characterized by single-crystal and powder X-ray diffraction methods and were found to crystallize in the monoclinic space group C2/m. The molybdates all contain rare infinite chains consisting of MoO2O4/2 edge-sharing octahedra. The chains exhibit alternating long and short separations between octahedra caused by the presence of Mo–Mo bonds to form Mo2O10 units containing one unpaired electron. The temperature dependence of the magnetic susceptibility of these compounds was measured, and antiferromagnetic ordering was observed in all cases.
Video-guided versus direct laryngoscopy: considerations for using simulation to teach inexperienced medical students

The goal of this study was to determine whether video laryngoscopy (VL) provides any advantage over direct laryngoscopy (DL) in first-attempt intubations. This was a controlled, randomized study of 120 medical students. Students were randomly assigned to either of 2 intubation groups, which used (1) DL (n=64) or (2) VL (n=56) with the Karl Storz C-MAC® video laryngoscope. Each student attempted 1 endotracheal intubation on a Laerdal® Airway Management Trainer. The primary outcome measure was the time for successful endotracheal intubation. Secondary outcome measures included the incidence of esophageal intubation (EI), excess application of pressure on the maxillary incisor teeth (EMP), and first-time success rate. Mean time for endotracheal intubation was significantly faster in the VL group than in the DL group (101 ± 83 seconds vs. 180 ± 102.5 seconds; P
Pathophysiological role of microRNA-29 in pancreatic cancer stroma

Dense fibrotic stroma associated with pancreatic ductal adenocarcinoma (PDAC) is a major obstacle for drug delivery to the tumor bed and plays a crucial role in pancreatic cancer progression. Current, anti-stromal therapies have failed to improve tumor response to chemotherapy and patient survival. Furthermore, recent studies show that stroma impedes tumor progression, and its complete ablation accelerates PDAC progression. In an effort to understand the molecular mechanisms associated with tumor-stromal interactions, using in vitro and in vivo models and PDAC patient biopsies, we show that the loss of miR-29 is a common phenomenon of activated pancreatic stellate cells (PSCs)/fibroblasts, the major stromal cells responsible for fibrotic stromal reaction. Loss of miR-29 is correlated with a significant increase in extracellular matrix (ECM) deposition, a major component in PDAC stroma. Our in vitro miR-29 gain/loss-of-function studies document the role of miR-29 in PSC-mediated ECM stromal protein accumulation. Overexpression of miR-29 in activated stellate cells reduced stromal deposition, cancer cell viability, and cancer growth in co-culture. Furthermore, the loss of miR-29 in TGF-β1 activated PSCs is SMAD3 dependent. These results provide insights into the mechanistic role of miR-29 in PDAC stroma and its potential use as a therapeutic agent to target PDAC.
Restricted Indian buffet processes

Latent feature models are a powerful tool for modeling data with globally-shared features. Nonparametric distributions over exchangeable sets of features, such as the Indian Buffet Process, offer modeling flexibility by letting the number of latent features be unbounded. However, current models impose implicit distributions over the number of latent features per data point, and these implicit distributions may not match our knowledge about the data. In this work, we demonstrate how the restricted Indian buffet process circumvents this restriction, allowing arbitrary distributions over the number of features in an observation. We discuss several alternative constructions of the model and apply the insights to develop Markov Chain Monte Carlo and variational methods for simulation and posterior inference.