cssi/SciSciGPT-SciSciNet huggingface dataset:
South Africa without apartheid: Estimates from general equilibrium simulations

A general equilibrium model of the South African economy in the 1980s is constructed, focusing on the labour-market distortions created by legal and customary restrictions on nonwhite labour mobility. The model is static and calibrated to the data of 1980; its simplified representation of the economy incorporates five production sectors, two race categories, two skill levels, and five kinds of labour-market constraints. Three counter-factual simulations are conducted: 1. The labour-market constraints are relaxed marginally, one at a time. Such change has little impact on either the level of GDP or its distribution. 2. The constraints are derived that would be preferred by different white sub-groups – were each sub-group to choose the various constraints so as to maximize its own income. No such group has uneconomic motive in keeping so many Blacks in the reserves. Beyond that, interests diverge. Urban capital would like to expand the entry of nonwhites into the cities and into skilled jobs. White farmers, white mining labour, and white urban unskilled labour would like to keep nonwhites out of the cities and out of skilled jobs. White urban skilled labour stands between these groups. 3. The outcome of perfectly free labour markets is examined, under the assumption that the education level of nonwhites permits them to move either slowly or rapidly into the newly accessible skilled jobs. GDP rises from five to ten per cent, and dramatic income redistribution is achieved. Some nonwhites experience wage increases up to one half; skilled whites are not much affected, and even the direction of the impact on them is unclear; profits increase by as much as one fifth; and the incomes of white farmers and unskilled white labourers my fall by more than one half. The measured changes owing to a transition to free labour markets, large as they are, represent no more than lower-bound estimates of the effects of apartheid since the simulations deal only with the racial restraints on labour markets and do not contemplate possible racial redistribution of the ownership of land, physical capital, or human capital.
Hysteresis, Avalanches, and Barkhausen Noise

We’ve been working on the crackling noise in hysteresis loops [1, 2, 3, 4, 5, 6]. Hysteresis occurs when you push and pull on a system with an external force, and the response lags behind the force. The hysteresis loop is the graph of force (say, an external magnetic field H) versus the response (say, the magnetization M of the material). In many materials, the hysteresis loop is not actually microscopically smooth: it is composed of small bursts, or avalanches (figure 1). In many first-order phase transitions, these bursts cause acoustic emission (crackling noise); in magnets, they are called Barkhausen noise.
An Evolutionarily Conserved Prion-like Element Converts Wild Fungi from Metabolic Specialists to Generalists

SUMMARY [GAR + ] is a protein-based element of inheritance that allows yeast (Saccharomyces cerevisiae )t o circumvent a hallmark of their biology: extreme metabolic specialization for glucose fermentation. When glucose is present, yeast will not use other carbon sources. [GAR + ] allows cells to circumvent this ‘‘glucose repression.’’ [GAR + ] is induced in yeast by a factor secreted by bacteria inhabiting their environment. We report that de novo rates of [GAR + ] appearance correlate with the yeast’s ecological niche. Evolutionarily distant fungi possess similar epigenetic elements that are also induced by bacteria. As expected for a mechanism whose adaptive value originates from the selective pressures of life in biological communities, the ability of bacteria to induce [GAR + ] and the ability of yeast to respond to bacterial signals have been extinguished repeatedly during the extended monoculture of domestication. Thus, [GAR + ] is a broadly conserved adaptive strategy that links environmental and social cues to heritable changes in metabolism.
Average Distance, Diameter, and Clustering in Social Networks with Homophily

I examine a random network model where nodes are categorized by type and linking probabilities can differ across types. I show that as homophily increases (so that the probability to link to other nodes of the same type increases and the probability of linking to nodes of some other types decreases) the average distance and diameter of the network are unchanged, while the average clustering in the network increases.
Global Assimilation of Ionospheric Measurements (GAIM)

Abstract : Our primary goal is to construct a real-time data assimilation model for the ionosphere-plasmasphere system that will provide reliable specifications and forecasts. A secondary goal is to validate the model for a wide range of geophysical conditions, including different solar cycle, seasonal, storm, and substorm conditions.
Inducing private wildfire risk mitigation: Experimental investigation of measures on adjacent public lands

Increasing private wildfire risk mitigation is an important part of the larger forest restoration policy challenge. Data from an economic experiment are used to evaluate the effectiveness of providing fuel reductions on public land adjacent to private land to induce private wildfire risk mitigation. Results show evidence of “crowding out” where public spending can decrease the level of private risk mitigation. Findings also indicate that spending on private mitigation efforts increase when information about individual expenditures are made available and spending on public land fuel reductions are conditional upon a threshold level of private mitigation effort being achieved.
Psychological Influence in Negotiation: An Introduction Long Overdue

This article begins with an analysis of the limited extent to which social influence research has penetrated the field of negotiation. The authors argue that one barrier has been that research on social influence focuses almost exclusively on economic or structural levers of influence. With this background, the article seeks to do the following: (a) define the domain of psychological influence as consisting of tactics that do not require the influencer to change the economic or structural aspects of the bargaining situation, (b) review prior decision research to identify ideas that may be relevant to psychological influence, (c) provide numerous examples of how decision research can be leveraged to create psychological influence tactics for negotiators, (d) consider how targets of influence might defend against the tactics herein considered, and (e) consider some of the ethical issues surrounding the use of psychological influence in negotiation.
Helper‐Dependent Adenoviral Vectors

The helper-dependent adenovirus (HDAd) is a recently developed adenovirus-based vector with an improved safety profile and long-term transgene expression. In this unit, a basic procedure for HDAd production using the Cre-loxP system is presented. Amplification and large-scale production of the vector can be done in both adherent and suspension cell culture systems. Included are protocols for Southern blot analysis to monitor vector amplification, slot blot assay to determine the infectious titer of the purified HDAd, and real-time PCR to detect helper virus contamination in the preparation.
Synthesis of cyathiformines A-C: Unusual fungal metabolites derived from chorismic acid

Abstract Expeditious syntheses of the title compounds are reported which lend credence to the apparent biogenetic relationship between the cyathiformines and (−)-chorismic acid.
An information processing approach to theory formation in biomedical research

The extensive literature on modeling of biological systems published in the past decade reflects the growing expectation that theories of biological functions can be subject to more exacting tests of consistency with the natural system, and yield more powerful predictions if embodied in the formal structure of computer programs.
Synthesis of dinucleoside and dinucleotide phosphorodithioates via a phosphotriester approach

Abstract 5′ -O-Dimethoxytrityl and S-protected thymidine-3′ -phosphorodithioate, 3′ -O-acetylthymidine or thymidine-3′ -O-[β-cyanoethyl-(S-2,4-dichlorobenzyl)]-phosphorodithioate, 1-methylimidazole, and 2,4,6-triisopropylbenzenesulfonylchloride react to give excellent yields of dinucleoside phosphorodithioates.
De-anonymizing Social Networks

Operators of online social networks are increasingly sharing potentially sensitive information about users and their relationships with advertisers, application developers, and data-mining researchers. Privacy is typically protected by anonymization, i.e., removing names, addresses, etc.We present a framework for analyzing privacy and anonymity in social networks and develop a new re-identification algorithm targeting anonymized social-network graphs. To demonstrate its effectiveness on real-world networks, we show that a third of the users who can be verified to have accounts on both Twitter, a popular microblogging service, and Flickr, an online photo-sharing site, can be re-identified in the anonymous Twitter graph with only a 12% error rate.Our de-anonymization algorithm is based purely on the network topology, does not require creation of a large number of dummy "sybil" nodes, is robust to noise and all existing defenses, and works even when the overlap between the target network and the adversary's auxiliary information is small.
Attentional Cues in Real Scenes, Saccadic Targeting, and Bayesian Priors

Performance finding a target improves when artificial cues direct covert attention to the target's probable location or locations, but how do predictive cues help observers search for objects in real scenes? Controlling for target detectability and retinal eccentricity, we recorded observers' first saccades during search for objects that appeared in expected and unexpected locations within real scenes. As has been found with synthetic images and cues, accuracy of first saccades was significantly higher when the target appeared at an expected location rather than an unexpected location. Observers' saccades with target-absent images make it possible to distinguish two mechanisms that might mediate this effect: limited attentional resources versus differential weighting of information (Bayesian priors). Endpoints of first saccades in target-absent images were significantly closer to the expected than the unexpected locations, a result consistent with the differential-weighting model and inconsistent with limited resources being the sole mechanism underlying the effect.
The History and State of the Art of Variable-Speed Wind Turbine Technology

Early wind turbines used for performing mechanical work (pumping, grinding and cutting) optimized aerodynamics by being allowed to run at variable speed. Some of the earliest DC electric wind turbines were allowed to run at variable speed. With the advent of grid-connected AC turbines, rotational speeds were limited in order to control the wind turbine AC frequency output to equal the grid frequency. With the advent of semiconductor devices, attempts began as early as the 1970s to allow variable-speed operation of large-scale turbines. The introduction of a new generation of high-voltage, high-speed power electronic components allows a wide range of variable-speed operation for very-large-scale machines. Over the past 30 years a number of designs have been tested, a few of which have entered commercial operation. A number of these designs and their histories are described. A detailed description of a wide range of electrical methods for allowing variable-speed operation is provided. Copyright © 2003 John Wiley & Sons, Ltd.
On The Role of Penetration Twins in The Morphological Development of Vapor-Grown Diamond Films

By control of deposition conditions, the morphologies of vapor-deposited polycrystalline diamond films may be varied deliberately from clean multi-micron crystallites to nanocrystalline ‘cauliflower’ nodules. Most attempts to connect diamond film ‘quality’ to growth conditions focus on competitive growth of non-diamond phases. In contrast, we propose that twinning is potentially the dominant factor. We develop a geometric parameterization of growth conditions to define conditions under which a common type of twin - the penetration twin - can outgrow and potentially bury the parent face on which it originated. We then show how the full range of CVD diamond crystal and film morphologies might be explained entirely in terms of penetration twins. This explanation does not entail reference to the actual mechanism of diamond growth. The geometric parameterization also suggests a ‘reactor map’ which serves as a powerful tool in process development and control.
Treatment of alcoholism as a chronic disorder

Abstract Alcoholism is a common disorder that tends to be chronic and relapsing. Although there is clear evidence that treatment can be expected to induce a period of remission or at least decreased symptoms, treatment of alcoholism is generally regarded as unsuccessful. Alcoholism should be approached as a chronic medical disorder such as diabetes or arthritis. Complete abstinence is the preferred goal, but “cures” or permanent abstinence from alcohol are rare. In this model, treatment benefits may be measured by length of remission, reduction in alcohol use, improvement in health and enhancement of social functioning. Treatment continues over a period of years, mainly on an outpatient basis with increasing intensity if symptoms recur. Medications that reduce craving for alcohol or diminish the euphoric effects of alcohol would be very helpful in the management of this chronic disorder. Preclinical studies have produced evidence for involvement of the endogenous opioid system in the reinforcing effects of alcohol. Recent controlled clinical trials of the opiate receptor antagonist naltrexone suggest that medications of this type may improve the results of treatment for alcoholism.
A G-band cryogenic MMIC heterodyne receiver module for astronomical applications

We report cryogenic noise temperature and gain measurements of a prototype heterodyne receiver module designed to operate in the atmospheric window centered on 150 GHz. The module utilizes monolithic microwave integrated circuit (MMIC) InP high electron mobility transistor (HEMT) amplifiers, a second harmonic mixer, and bandpass filters. Swept local oscillator (LO) measurements show an average gain of 22 dB and an average noise temperature of 87 K over a 40 GHz band from 140 to 180 GHz when the module is cooled to 22 K. A spot noise temperature of 58 K was measured at 166 GHz and is a record for cryogenic noise from HEMT amplifiers at this frequency. Intermediate frequency (IF) sweep measurements show a 20 GHz IF band with less than 94 K receiver noise temperature for a fixed LO of 83 GHz. The compact housing features a split-block design that facilitates quick assembly and a condensed arrangement of the MMIC components and bias circuitry. DC feedthroughs and nano-miniature connectors also contribute to the compact design, so that the dimensions of the moduleare approximately 2.5 cm per side.
Germ-line engineering, freedom, and future generations

New technologies in germ-line engineering have raised many questions about obligations to future generations. In this article, I focus on the importance of increasing freedom and the equality of freedom for present and future generations, because these two ideals are necessary for a just society and because they are most threatened by the wide-scale privatisation of GLE technologies. However, there are ambiguities in applying these ideals to the issue of genetic technologies. I argue that Amartya Sen's capability theory can be used as a framework to ensure freedom and equality in the use of GLE technology. Capability theory articulates the goal of equalising real freedom by bringing all people up to a threshold of basic human capabilities. Sen's capability theory can clarify the proper moral goal of GLE insofar as this technology could be used to bring people up to certain basic human capabilities, thereby increasing their real freedom. And by increasing the freedom of those who lack basic human capabilities, GLE can aid in decreasing the inequalities of freedom among classes of people.
On state constraint representations and mesh-dependent gradient projection convergence rates for optimal control problems

This note briefly summarizes the main results in a SIAM article (Dunn, 2000) with the same title. In the SIAM paper, two distinct nonlinear programming formulations are investigated for ODE optimal control problems with pointwise state and control constraints. The first formulation treats the differential equations of state as an equality constraint in the conventional manner. The second formulation employs a different equality constraint entailing the integrated state transition map. Related convergence rate estimates are developed for augmented gradient projection methods and discrete-time approximations to a large representative class of ODE control problems. In the first formulation, the rate estimates are mesh-dependent, and the predicted number of inner loop gradient projection iterations needed to achieve a fixed small deviation from the optimal value of the augmented Lagrangian is inversely proportional to the square of the mesh width. In the second formulation, the convergence rates and predicted iteration counts are mesh-invariant. The computational costs-per-iteration in the two formulations are comparable.
“Appropriate” diagnostic testing: supporting diagnostics with evidence-based medicine and shared decision making

Background: Evidence-based medicine is an important approach to avoiding care that is unlikely to benefit patients in both the treatment and the diagnostic context. The medical evidence alone may not determine the most appropriate care decision. Patient interests are best served when the advantages and risks of a diagnostic test are viewed through the lens of the patient’s values. That is, the paradigm of evidence-based medicine should be complemented by the paradigm of shared decision making. Analysis: Diagnostic testing may offer physiological and psychological benefits. Clinicians should also discuss the potential harms, however, which may be physiological (e.g. radiation or scarring), psychological (e.g. anxiety), and financial (e.g. cost-sharing burdens). All three of these concerns are compounded by the risk of false positives or incidental findings that are not serious, but which require decisions about further testing or treatment. Conclusion: We suggest that patient-centered decision making around diagnostic testing involves a two-step inquiry: (1) Is the test medically appropriate? Does the available evidence documenting short- and long-term risk and benefits support the test for its intended use, given the patient’s characteristics and symptoms? (2) Is the test appropriate for this patient? Has the provider initiated a conversation about tradeoffs that helps the patient evaluate whether the balance of risks and benefits is consonant with the patient’s own values and preferences? Potential benefits and harms to consider include the physiological, the psychological, and the financial.
The Role of Tropospheric Rossby Wave Breaking in the Pacific Decadal Oscillation

Abstract The leading pattern of extratropical Pacific sea surface temperature variability [the Pacific decadal oscillation (PDO)] is shown to depend on observed variability in the spatiotemporal distribution of tropospheric Rossby wave breaking (RWB), where RWB is the irreversible overturning of potential vorticity on isentropic surfaces. Composite analyses based on hundreds of RWB cases show that anticyclonic (cyclonic) RWB is associated with a warm, moist (cool, dry) column that extends down to a surface anticyclonic (cyclonic) circulation, and that the moisture and temperature advection associated with the surface circulation patterns force turbulent heat flux anomalies that project onto the spatial pattern of the PDO. The RWB patterns that are relevant to the PDO are closely tied to El Nino–Southern Oscillation, the Pacific–North American pattern, and the northern annular mode. These results explain the free troposphere-to-surface segment of the atmospheric bridge concept wherein El Nino anomalies eme...
Experimental Study of Channel Patterns

A series of experiments was performed in a large flume to determine the effect of slope and sediment load on channel patterns. Sediment loads and slopes were closely related, and as slope and sediment loads increased, threshold values of these variables were encountered, at which channel patterns altered significantly. At a very low slope and sediment load, the channels remained straight, but at a discharge of 0.15 cfs, a meandering-thalweg channel formed at slopes greater than 0.002. With increased slope and sediment loads, thalweg sinuosity increased to a maximum of 1.25. At slopes greater than 0.016, a braided channel formed. The model channels responded to increased sediment loads by maintaining steeper gradients and by major channel pattern changes, but at very gentle slopes and at steep slopes, the channel could not be forced to develop a meandering thalweg. These experiments suggest that landforms may not always respond progressively to altered conditions. Rather, dramatic morphologic changes can occur abruptly when critical erosional and (or) depositional threshold values are exceeded. The meandering-thalweg channel was not a meandering channel. A truly meandering channel with a sinuosity of 1.3 formed when a suspended-sediment load (3 percent concentrations of kaolinite) was introduced into the flow. The clay stabilized the alternate bars, and scour and deepening of the thalweg resulted. This in turn lowered the water level at constant discharge, and the alternate bars emerged o t form point bars. A meandering-thalweg channel was thus converted to a meandering channel by the type of sediment load change that has accompanied climatic and hydrologic changes of the recent geologic past.
Fiscal policy and the US stock market

This paper empirically explores the short- and long-run effects of fiscal and monetary policies on US stock returns and tests the validity of market efficiency. The results support the presence of a strong long-run (equilibrium) relation binding stock prices with fiscal (but not monetary) policy. Further tests assign a dominant role to fiscal policy as a main force driving the overall equilibrium relation with the stock market. Estimates from error-correction models corroborate the existence of robust long-run relation and further suggest that past fiscal (but not monetary) policy actions exert significant short-run effects on current stock returns. A similar verdict emerged from alternative estimates in which fiscal policy actions anticipated from an ex ante equation continue to support a significant lagged relation with current stock returns. These results provide consistent evidence that important effects of fiscal policy are transmitted to the real economy through the stock market. Moreover, the results for fiscal policy appear at variance with market efficiency. However, transaction costs and other well-known modeling caveats may impede implications for profitable investment strategies.
Compact objects for everyone: I. White dwarf stars

Based upon previous discussions on the structure of compact stars geared towards undergraduate physics students, a real experiment involving two upper-level undergraduate physics students, a beginning physics graduate and two advanced graduate students was conducted. A recent addition to the physics curriculum at Florida State University, The Physics of Stars, sparked quite a few students' interests in the subject matter involving stellar structure. This, coupled with Stars and statistical physics by Balian and Blaizot (1999 Am. J. Phys. 67 1189) and Neutron stars for undergraduates by Silbar and Reddy (2004 Am. J. Phys. 72 892), is the cornerstone of this small research group who tackled solving the structure equations for compact objects in the summer of 2004. Through the use of a simple finite-difference algorithm coupled to Microsoft Excel and Maple, solutions to the equations for stellar structure are presented in the Newtonian regime appropriate to the physics of white dwarf stars.
Adaptationist punishment in humans

Immanuel Kant, Adam Smith, Charles Darwin, George Williams, and Stephen J. Gould, among others, have pointed out that observing that a certain behavior causes a certain effect does not itself license the inference that the effect was the result of intent or design to bring about that effect. Compliance with duty might not reflect the action of conscience, gains in trade might not be due to the benevolence of traders, and fox paws might not be designed to make tracks in snow. Similarly, when person A inflicts costs on person B and, in so doing, generates benefits to C, D, and E (or the group to which A through E belong, in aggregate), the inference that A’s imposition of costs on B is by virtue of intent or design to bring about these welfare gains is not logically licensed. In short, labeling punishment “altruistic” because it has the effect of benefitting some individuals is inconsistent with key ideas in philosophy, economics, and biology. Understanding the ultimate cause and proximate design of the mechanisms that cause people to punish is likely to be important for understanding how punishment can help solve collective action problems.
On the effective and automatic enumeration of polynomial permutation classes

We describe an algorithm, implemented in Python, which can enumerate any permutation class with polynomial enumeration from a structural description of the class. In particular, this allows us to find formulas for the number of permutations of length n which can be obtained by a finite number of block sorting operations (e.g., reversals, block transpositions, cut-and-paste moves).
Visible light optical coherence tomography for retinal oximetry

We presented the method of using visible-light optical coherence tomography (vis-OCT) for retinal oximetry. We demonstrated for the first time in vivo OCT measurement of the arterial and venous oxygenation in retinal circulation.
Bandstructure Effects in Silicon Nanowire Electron Transport

Bandstructure effects in the electronic transport of strongly quantized silicon nanowire field-effect-transistors (FET) in various transport orientations are examined. A 10-band sp3d5s* semiempirical atomistic tight-binding model coupled to a self-consistent Poisson solver is used for the dispersion calculation. A semi-classical, ballistic FET model is used to evaluate the current-voltage characteristics. It is found that the total gate capacitance is degraded from the oxide capacitance value by 30% for wires in all the considered transport orientations ([100], [110], [111]). Different wire directions primarily influence the carrier velocities, which mainly determine the relative performance differences, while the total charge difference is weakly affected. The velocities depend on the effective mass and degeneracy of the dispersions. The [110] and secondly the [100] oriented 3 nm thick nanowires examined, indicate the best ON-current performance compared to [111] wires. The dispersion features are strong functions of quantization. Effects such as valley splitting can lift the degeneracies particularly for wires with cross section sides below 3 nm. The effective masses also change significantly with quantization, and change differently for different transport orientations. For the cases of [100] and [111] wires the masses increase with quantization, however, in the [110] case, the mass decreases. The mass variations can be explained from the non-parabolicities and anisotropies that reside in the first Brillouin zone of silicon.
Some families of permutation polynomials over finite fields

We give necessary and sufficient conditions for a polynomial of the form xr(1 + xv + x2v + ⋯ + xkv)t to permute the elements of the finite field &#x1d53d;q. Our results yield especially simple criteria in case (q - 1)/gcd(q - 1, v) is a small prime.
Synthesis and Structure Reassessment of Psammopemmin A

We have isolated meridianins A, B, C, and E from the Antarctic tunicate Synoicum sp. In the process of verifying the structure of these compounds it was noted that the physical data reported for meridianins bore a striking resemblance to that of psammopemmins. The psammopemmins are alkaloids bearing similar structures to the meridianins, but reported from the Antarctic sponge Psammopemma sp. To verify the structure originally proposed for psammopemmin A, the compound was synthesized. By comparing the 1H and 13C NMR data of reported and synthetic psammopemmin A with that of meridianin A, we infer that the correct structure of psammopemmin A isolated from Psammopemma sp. is actually that of meridianin A.
The Relevance of a Choice of Auction Format in a Competitive Environment

We examine the relevance of an auction format in a competitive environment by comparing uniform and discriminatory price auctions with many bidders in a private values setting. We show that if the number of objects for sale is small relative to the number of bidders, then all equilibria of both auctions are approximately efficient and lead to approximately the same revenue. When the number of objects for sale is proportional to the number of bidders, then the particulars of the auction format matter. All equilibria of the uniform auction are efficient, while all of the equilibria of the discriminatory auction are inefficient. The relative revenue rankings of the auction formats can go in either direction, depending on the specifics of the environment. These conclusions regarding the efficiency and revenue ranking are in contrast to the previous literature, which focused on the case of independent information across agents.
Stannous Chloride in Alcohol: A One-Pot Conversion of 2-Nitro-N-arylbenzamides to 2,3-Dihydro-1H-quinazoline-4-ones

A novel one-step synthesis of 2,3-dihydro-1H-quinazolin-4-ones from 2-nitrobenzamides is reported. These reactions are mediated by stannous chloride in 0.02 M methanolic or ethanolic HCl solution and proceed in good yields.
The Magellanic Stream: Circumnavigating the Galaxy

The Magellanic Clouds are surrounded by an extended network of gaseous structures. Chief among these is the Magellanic Stream, an interwoven tail of filaments trailing the Clouds in their orbit around the Milky Way. When considered in tandem with its Leading Arm, the Stream stretches over 200° on the sky. The Stream is thought to represent the result of tidal interactions between the Clouds and ram-pressure forces exerted by the Galactic corona, and its kinematic properties reflect the dynamical history of the pair of dwarf galaxies closest to the Milky Way. The Stream is a benchmark for hydrodynamical simulations of accreting gas and cloud/corona interactions. If the Stream survives these interactions and arrives safely in the Galactic disk, its cargo of over a billion solar masses of gas has the potential to maintain or elevate the Galactic star-formation rate. In this article, we review the current state of knowledge of the Stream, including its chemical composition, physical conditions, origin, and fa...
Piperazine-linked bisbenzamidines: a novel class of antileishmanial agents.

Abstract A series of 13 1,4-diarylpiperazines has been prepared, evaluated for antileishmanial activity and their binding affinity to DNA was measured. Among these compounds, 1,4-bis[4-(1 H -benzimidazol-2-yl)phenyl]piperazine ( 14 ) emerged as the most active compound with an IC 50 value of 0.41 μM which is about sevenfold more potent than pentamidine.
CALIPSO-inferred aerosol direct radiative effects: Bias estimates using ground-based Raman lidars

Observational constraints on the change in the radiative energy budget caused by the presence of aerosols, i.e. the aerosol direct radiative effect (DRE), have recently been made using observations from the Cloud- Aerosol Lidar and Infrared Pathfinder Satellite (CALIPSO). CALIPSO observations have the potential to provide improved global estimates of aerosol DRE compared to passive sensor-derived estimates due to CALIPSO's ability to perform vertically-resolved aerosol retrievals over all surface types and over cloud. In this study we estimate the uncertainties in CALIPSO-inferred aerosol DRE using multiple years of observations from the Atmospheric Radiation Measurement (ARM) program's Raman lidars (RL) at mid-latitude and tropical sites. Examined are assumptions about the ratio of extinction-to-backscatter (i.e. the lidar ratio) made by the CALIPSO retrievals, which are needed to retrieve the aerosol extinction profile. The lidar ratio is shown to introduce minimal error in the mean aerosol DRE at the top-of-atmosphere and surface. It is also shown that CALIPSO is unable to detect all radiatively-significant aerosol, resulting in an underestimate in the magnitude of the aerosol DRE by 30â€"50%. Therefore, global estimates of the aerosol DRE inferred from CALIPSO observations are likely too weak.
Efficient and Exact MAP-MRF Inference using Branch and Bound

We propose two novel Branch-and-Bound (BB) methods to efficiently solve exact MAPMRF inference on problems with a large number of states (per variable) H. By organizing the data in a suitable structure, the time complexity of our best method for evaluating the bound at each branch is reduced from O(H) to O(H). This permits searching for the MAP solution in O(BH +Q) instead of O(BH) (without using the data structure), where B is the number of branches and Q is the one-time cost to build the data structure which is proportional to H. Our analysis on synthetic data shows that, given a limited time budget, our method solves problems that are characterized by a much larger number of states when compared to stateof-the-art exact inference algorithms (e.g., Marinescu and Dechter (2007); Sontag et al. (2008)) and other baseline BB methods. We further show that our method is well suited for computer vision and computational biology problems where the state space (per variable) is large. In particular, our approach is an order of magnitude faster on average than Sontag et al.’s Cluster Pursuit (CP) on human pose estimation problems. Moreover, given a time budget of up to 20 minutes, our method consistently solves more protein design problems than CP does. Finally, we successfully explore different branching strategies and ways to utilize domain knowledge of the problem to significantly reduce the empirical inference time.
Improving college access in the United States: barriers and policy responses

Abstract Socioeconomic gaps in college enrollment and attainment have widened over time, despite increasing returns to postsecondary education and significant policy efforts to improve access. We describe the barriers that students face during the transition to college and review the evidence on potential policy solutions. We focus primarily on research that examines causal relationships using experimental or quasi-experimental methods, though we draw upon descriptive evidence to provide context. Our review is distinctive in three respects. First, in addition to the literature on financial aid, we examine the evidence on informational and behavioral interventions, academic programs, and affirmative action policies intended to improve college access. Second, we incorporate a wealth of recent research not included in prior reviews. Finally, we conceptualize college access broadly, as including not just whether but also where students attend and whether they have access to college-level courses. We conclude with a discussion of implications for policy and research.
Optically pumped alkali lasers

Optically pumped alkali vapor lasers have been developed during last several years. Efficient operation of Cesium, Rubidium and Potassium vapor lasers has been demonstrated. Laser slope efficiencies higher than 80% have been achieved. In this paper we present the latest achievements in this field, discuss the main directions and problems in high power alkali lasers development and possible solutions of these problems.
Unicyclic components in random graphs

The distribution of unicyclic components in a random graph is obtained analytically. The number of unicyclic components of a given size approaches a self-similar form in the vicinity of the gelation transition. At the gelation point, this distribution decays algebraically, Uk (4k)?1 for k 1. As a result, the total number of unicyclic components grows logarithmically with the system size.
Improved Practical Matrix Sketching with Guarantees

Matrices have become essential data representations for many large-scale problems in data analytics, and hence matrix sketching is a critical task. Although much research has focused on improving the error/size tradeoff under various sketching paradigms, the many forms of error bounds make these approaches hard to compare in theory and in practice. This paper attempts to categorize and compare the most known methods under row-wise streaming updates with provable guarantees, and then to tweak some of these methods to gain practical improvements while retaining guarantees. For instance, we observe that a simple heuristic iSVD, with no guarantees, tends to outperform all known approaches in terms of size/error trade-off. We modify the best performing method with guarantees, FrequentDirections , under the size/error trade-off to match the performance of iSVD and retain its guarantees. We also demonstrate some adversarial datasets where iSVD performs quite poorly. In comparing techniques in the time/error trade-off, techniques based on hashing or sampling tend to perform better. In this setting, we modify the most studied sampling regime to retain error guarantee but obtain dramatic improvements in the time/error trade-off. Finally, we provide easy replication of our studies on APT, a new testbed which makes available not only code and datasets, but also a computing platform with fixed environmental settings.
A Geostatistical Framework for Quantifying the Temporal Evolution and Predictability of Rainfall Fields

AbstractA geostatistical framework for quantifying the temporal evolution and predictability of rainfall fields for time lags between 5 min and 3 h is proposed. The method is based on the computation of experimental space–time variogram maps of radar reflectivity fields. Two new metrics for quantifying temporal innovation and predictability based on minimum semivariance values at different time lags are proposed. The method is applied to high-resolution composite radar reflectivity maps over the United States to study the evolution of 25 convective and 25 stratiform events during the warm season of 2014. Results show that the temporal innovation can be modeled as the sum of two exponential functions of time lag, with approximately 50% of the total innovation occurring over the first 60 min. The median predictable scales for convective events are on the order of 1.6 km at 5 min, 5 km at 15 min, and 12.7 km at 1 h. Furthermore, the optimal time lag for predicting future innovation, taking into account measu...
Successive Rank-One Approximations for Nearly Orthogonally Decomposable Symmetric Tensors

Many idealized problems in signal processing, machine learning, and statistics can be reduced to the problem of finding the symmetric canonical decomposition of an underlying symmetric and orthogonally decomposable (SOD) tensor. Drawing inspiration from the matrix case, the successive rank-one approximation (SROA) scheme has been proposed and shown to yield this tensor decomposition exactly, and a plethora of numerical methods have thus been developed for the tensor rank-one approximation problem. In practice, however, the inevitable errors (say) from estimation, computation, and modeling necessitate that the input tensor can only be assumed to be a nearly SOD tensor---i.e., a symmetric tensor slightly perturbed from the underlying SOD tensor. This paper shows that even in the presence of perturbation, SROA can still robustly recover the symmetric canonical decomposition of the underlying tensor. It is shown that when the perturbation error is small enough, the approximation errors do not accumulate with ...
QUANTITATIVE MEASUREMENT OF TRANSPLANTATION IMMUNITY.

Investigations of the basic mechanisms of transplantation rejection have been hampered in the past by the cumbersome techniques available for determination of transplantation immunity. These have included the gross and microscopic estimation of skin or organ graft survival and more recently the delayed intradermal skin test described by Brent [1]. Interpretation of these methods has been subjective, and their evaluation should be considered to be qualitative. The present experiments were designed to determine if passive transfer of radioactive labeled homologous cells could be used as a technique of quantitation of homograft rejection.
Degrees of Freedom for the MIMO Multi-Way Relay Channel

This paper investigates the degrees of freedom (DoF) of the L-cluster, K-user MIMO multiway relay channel, where users in each cluster wish to exchange messages within the cluster, and they can only communicate through the relay. A novel DoF upper bound is derived by providing users with carefully designed genie information. Achievable DoF is identified using signal space alignment and multiple-access transmission. For the two-cluster MIMO multiway relay channel with two users in each cluster, the DoF is established for the general case when users and the relay have arbitrary number of antennas, and it is shown that the DoF upper bound can be achieved using signal space alignment or multiple-access transmission, or a combination of both. The result is then generalized to the three user case. For the L-cluster K-user MIMO multiway relay channel in the symmetric setting, conditions under which the DoF upper bound can be achieved are established. In addition to being shown to be tight in a variety of scenarios of interests of the multiway relay channel, the newly derived upperbound also establishes the optimality of several previously established achievable DoF results for multiuser relay channels that are special cases of the multiway relay channel.
Enhancements to a Simple Pavement Frost Model

The ability to predict the timing of thaw is important to the design and the maintenance of roads. Such knowledge allows highway agencies to reduce the damage caused by enacting seasonal load restrictions during thawing. Because measurement by observation or testing requires time and resources, one desirable solution is a predictive model. Simple models, such as the Cornell Pavement Frost Model (CPFM), require only daily temperature weather inputs. Possible improvements to the CPFM were tried with a primary goal of improving thaw timing while keeping the model simple and applicable across New York State and beyond. The proposed modifications included changing the thaw reference temperature, providing better tracking of thermal properties throughout seasonal changes, and driving thaw from underneath with a constant underground temperature. During the investigation, further changes were tested involving ways to treat latent heat during thaw, including decoupling. Changes were tested against frost tube data ...
Using Bayesian optimization to guide probing of a flexible environment for simultaneous registration and stiffness mapping

One of the goals of computer-aided surgery is to register intraoperative data to preoperative model of the anatomy, and hence add complementary information that can facilitate the task of surgical navigation. In this context, mechanical palpation can reveal critical anatomical features such as arteries and cancerous lumps which are stiffer than the surrounding tissue. This work uses position and force measurements obtained during mechanical palpation for registration and stiffness mapping. Prior approaches, including our own, exhaustively palpated the entire organ to achieve this goal. To overcome the costly palpation of the entire organ, a Bayesian optimization framework is introduced to guide the end effector to palpate stiff regions while simultaneously updating the registration of the end effector to an a priori geometric model of the organ, hence enabling the fusion of intraoperative data into the a priori model obtained through imaging. This new framework uses Gaussian processes to model the stiffness distribution and Bayesian optimization to direct where to sample next for maximum information gain. The proposed method was evaluated with experimental data obtained using a Cartesian robot interacting with a silicone organ model and an ex vivo porcine liver.
Reductive Lithiation in the Absence of Aromatic Electron Carriers. A Steric Effect Manifested on the Surface of Lithium Metal Leads to a Difference in Relative Reactivity Depending on Whether the Aromatic Electron Carrier Is Present or Absent

One of the most widely used methods of preparation of organolithium compounds is by the reductive lithiation of alkyl phenyl thioethers or, usually less conveniently, alkyl halides with either aromatic radical-anions of lithium or lithium metal in the presence of an aromatic electron-transfer catalyst. Here we present results showing that lithium dispersion can achieve reductive lithiation in the absence of the electron-transfer agent. This procedure is more efficient, and surprisingly, the order of reactivity of substrates is reversed depending on whether the electron-transfer agent is present or absent. For example, in the presence of a preformed radical-anion, tert-butyl phenyl sulfide cleaves significantly faster than methyl phenyl sulfide, whereas in the absence of the radical-anion, it is just the opposite. Density functional theory calculations reveal that the exothermicity of the cleavage of the C–S bond in alkyl phenyl thioethers on the lithium surface is dependent on the size of the alkyl group,...
Sorted Neighborhood for Schema-Free RDF Data

Entity Resolution ER concerns identifying pairs of entities that refer to the same underlying entity. To avoid $$On^2$$ pairwise comparison of n entities, blocking methods are used. Sorted Neighborhood is an established blocking method for Relational Databases. It has not been applied to schema-free Resource Description Framework RDF data sources widely prevalent in the Linked Data ecosystem. This paper presents a Sorted Neighborhood workflow that may be applied to schema-free RDF data. The workflow is modular and makes minimal assumptions about its inputs. Empirical evaluations of the proposed algorithm on five real-world benchmarks demonstrate its utility compared to two state-of-the-art blocking baselines.